Subject: Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION Date: August 24, 2005 at 2:47 pm PST
August 24, 2005
Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION
Greetings APHIS ET AL,
My name is Terry S. Singeltary Sr.
I would kindly like to comment on [Docket No. 05-004-1] RIN 0579-AB93 ;
PROPOSED RULES Exportation and importation of animals and animal products: Whole cuts of boneless beef from- Japan, 48494-48500 [05-16422]
[Federal Register: August 18, 2005 (Volume 70, Number 159)] [Proposed Rules] [Page 48494-48500] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr18au05-7]
======================================================================== Proposed Rules Federal Register ________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.
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[[Page 48494]]
DEPARTMENT OF AGRICULTURE
Animal and Plant Health Inspection Service
9 CFR Part 94
[Docket No. 05-004-1] RIN 0579-AB93
Importation of Whole Cuts of Boneless Beef from Japan
AGENCY: Animal and Plant Health Inspection Service, USDA.
ACTION: Proposed rule.
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SUMMARY: We are proposing to amend the regulations governing the importation of meat and other edible animal products by allowing, under certain conditions, the importation of whole cuts of boneless beef from Japan. We are proposing this action in response to a request from the Government of Japan and after conducting an analysis of the risk that indicates that such beef can be safely imported from Japan under the conditions described in this proposal.
DATES: We will consider all comments that we receive on or before September 19, 2005.
ADDRESSES: You may submit comments by any of the following methods: EDOCKET: Go to http://www.epa.gov/feddocket to submit or
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BSE infectivity has never been demonstrated in the muscle tissue of cattle experimentally or naturally infected with BSE at any stage of the disease. Studies performed using TSEs other than BSE in non-bovine animals have detected prions in muscle tissue. However, the international scientific community largely considers that these studies cannot be directly extrapolated to BSE in cattle because of the significant interactions between the host species and the prion strain involved. Pathogenesis studies of naturally and experimentally infected cattle have not detected BSE infectivity in blood. However, transmission of BSE was demonstrated in sheep that received a transfusion of a large volume of blood drawn from other sheep that were experimentally infected with the BSE agent. The United Kingdom's Department for Environment, Food and Rural Affairs' Spongiform Encephalopathy Advisory Committee (SEAC) and the European Commission's Scientific Steering Committee (SSC), which are scientific advisory committees, evaluated the implication of this finding in relation to food safety.\5\ The SEAC concluded that the finding did not represent grounds for recommending any changes to the current control measures for BSE. The SSC determined that the research results do not support the hypothesis that bovine blood or muscle meat constitute a risk to human health.\6\
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BSE Risk Factors for Whole Cuts of Boneless Beef
The most significant risk management strategy for ensuring the safety of whole cuts of boneless beef is the prevention of cross- contamination of the beef with SRMs during stunning and slaughter of the animal. Control measures that prevent contamination of such beef involve the establishment of procedures for the removal of SRMs, prohibitions on air-injection stunning and pithing, and splitting of carcasses. These potential pathways for contamination and the control measures that prevent contamination are described in detail in the risk analysis for this rulemaking. SRM Removal. Research has demonstrated that SRMs from infected cattle may contain BSE infectivity. Because infectivity has not been demonstrated in muscle tissue, the most important mitigation measure for whole cuts of boneless beef is the careful removal and segregation of SRMs. Removal of SRMs in a manner that avoids contamination of the beef with SRMs minimizes the risk of exposure to materials that have been demonstrated to contain the BSE agent in cattle.
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Variant Creutzfeldt-Jakob disease (vCJD), a chronic and fatal neurodegenerative disease of humans, has been linked since 1996 through epidemiological, neuropathological, and experimental data to exposure to the BSE agent, most likely through consumption of cattle products contaminated with the agent before BSE control measures were in place. To date, approximately 170 probable and confirmed cases of vCJD have been identified worldwide. The majority of these cases have either been identified in the United Kingdom or were linked to exposure that occurred in the United Kingdom, and all cases have been linked to exposure in countries with native cases of BSE. Some studies estimate that more than 1 million cattle may have been infected with BSE throughout the epidemic in the United Kingdom. This number of infected cattle could have introduced a significant amount of infectivity into the human food supply. Yet, the low number of cases of vCJD identified to date indicates that there is a substantial species barrier that protects humans from widespread illness due to exposure to the BSE agent.
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International Guidelines on BSE
International guidelines for trade in animal and animal products are developed by the World Organization for Animal Health (formerly known as the Office International des Epizooties (OIE)), which is recognized by the World Trade Organization (WTO) as the international organization responsible for the development of standards, guidelines, and recommendations with respect to animal health and zoonoses (diseases that are transmissible from animals to humans). The OIE guidelines for trade in terrestrial animals (mammals, birds, and bees) are detailed in the Terrestrial Animal Health Code (available on the internet at http://www.oie.int). The guidelines on BSE are contained in
Chapter 2.3.13 of the Code and supplemented by Appendix 3.8.4 of the Code.
snip...end http://a257.g.akamaitech.net/7/257/2422/01jan20051800/edocket.access.gpo.gov/2005/05-16422.htm http://a257.g.akamaitech.net/7/257/2422/01jan20051800/edocket.access.gpo.gov/2005/pdf/05-16422.pdf
Greetings again APHIS ET AL,
THIS is not correct. IN fact, there are several factors i would like to kindly address.
Muscle tissue has recently been detected with PrPSc in the peripheral nerves (sciatic nerve, tibial nerve, vagus nerve) of the 11th BSE cow in Japan (Yoshifumi Iwamaru et al). also recently, Aguzzi et al Letter to the Editor Vet Pathol 42:107-108 (2005), Prusiner et al CDI test is another example of detection of the TSE agent in muscle in sCJD, Herbert Budka et al CJD and inclusion body myositis: Abundant Disease-Associated Prion Protein in Muscle, and older studies from Watson Meldrum et al Scrapie agent in muscle - Pattison I A (1990), references as follow ;
PrPSc distribution of a natural case of bovine spongiform encephalopathy
Yoshifumi Iwamaru, Yuka Okubo, Tamako Ikeda, Hiroko Hayashi, Mori- kazu Imamura, Takashi Yokoyama and Morikazu Shinagawa
Priori Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba 305-0856 Japan gan@affrc.go.jp
Abstract
Bovine spongiform encephalopathy (BSE) is a disease of cattle that causes progressive neurodegeneration of the central nervous system. Infectivity of BSE agent is accompanied with an abnormal isoform of prion protein (PrPSc).
The specified risk materials (SRM) are tissues potentially carrying BSE infectivity. The following tissues are designated as SRM in Japan: the skull including the brain and eyes but excluding the glossa and the masse- ter muscle, the vertebral column excluding the vertebrae of the tail, spinal cord, distal illeum. For a risk management step, the use of SRM in both animal feed or human food has been prohibited. However, detailed PrPSc distribution remains obscure in BSE cattle and it has caused con- troversies about definitions of SRM. Therefore we have examined PrPSc distribution in a BSE cattle by Western blotting to reassess definitions of SRM.
The 11th BSE case in Japan was detected in fallen stock surveillance. The carcass was stocked in the refrigerator. For the detection of PrPSc, 200 mg of tissue samples were homogenized. Following collagenase treatment, samples were digested with proteinase K. After digestion, PrPSc was precipitated by sodium phosphotungstate (PTA). The pellets were subjected to Western blotting using the standard procedure. Anti-prion protein monoclonal antibody (mAb) T2 conjugated horseradish peroxidase was used for the detection of PrPSc.
PrPSc was detected in brain, spinal cord, dorsal root ganglia, trigeminal ganglia, sublingual ganglion, retina. In addition, PrPSc was also detected in the peripheral nerves (sciatic nerve, tibial nerve, vagus nerve).
Our results suggest that the currently accepted definitions of SRM in BSE cattle may need to be reexamined. ...
179
T. Kitamoto (Ed.) PRIONS Food and Drug Safety ================
ALSO from the International Symposium of Prion Diseases held in Sendai, October 31, to November 2, 2004;
Bovine spongiform encephalopathy (BSE) in Japan
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"Furthermore, current studies into transmission of cases of BSE that are atypical or that develop in young cattle are expected to amplify the BSE prion"
NO. Date conf. Farm Birth place and Date Age at diagnosis
8. 2003.10.6. Fukushima Tochigi 2001.10.13. 23
9. 2003.11.4. Hiroshima Hyogo 2002.1.13. 21
Test results
# 8b, 9c cows Elisa Positive, WB Positive, IHC negative, histopathology negative
b = atypical BSE case
c = case of BSE in a young animal
b,c, No PrPSc on IHC, and no spongiform change on histology
International Symposium of Prion Diseases held in Sendai, October 31, to November 2, 2004.
The hardback book title is 'PRIONS' Food and Drug Safety T. Kitamoto (Ed.)
Tetsuyuki Kitamoto Professor and Chairman Department of Prion Research Tohoku University School of Medicine 2-1 SeiryoAoba-ku, Sendai 980-8575, JAPAN TEL +81-22-717-8147 FAX +81-22-717-8148 e-mail; kitamoto@mail.tains.tohoku.ac.jp Symposium Secretariat Kyomi Sasaki TEL +81-22-717-8233 FAX +81-22-717-7656 e-mail: kvomi-sasaki@mail.tains.tohoku.ac.ip
================================
107
Vet Pathol 42:107-108 (2005)
Letters to the Editor
Editor:
Absence of evidence is not always evidence of absence.
In the article ''Failure to detect prion protein (PrPres) by
immunohistochemistry in striated muscle tissues of animals
experimentally inoculated with agents of transmissible spongiform
encephalopathy,'' recently published in Veterinary
Pathology (41:78-81, 2004), PrPres was not detected in striated
muscle of experimentally infected elk, cattle, sheep, and
raccoons by immunohistochemistry (IHC). Negative IHC,
however, does not exclude the presence of PrPSc. For example,
PrPres was detected in skeletal muscle in 8 of 32
humans with the prion disease, sporadic Creutzfeldt-Jakob
disease (CJD), using sodium phosphotungstic acid (NaPTA)
precipitation and western blot.1 The NaPTA precipitation,
described by Wadsworth et al.,3 concentrates the abnormal
isoform of the prion, PrPres, from a large tissue homogenate
volume before western blotting. This technique has increased
the sensitivity of the western blot up to three orders
of magnitude and could be included in assays to detect
PrPres. Extremely conspicuous deposits of PrPres in muscle
were detected by IHC in a recent case report of an individual
with inclusion body myositis and CJD.2 Here, PrPres was
detected in the muscle by immunoblotting, IHC, and paraf-
fin-embedded tissue blot. We would therefore caution that,
in addition to IHC, highly sensitive biochemical assays and
bioassays of muscle are needed to assess the presence or
absence of prions from muscle in experimental and natural
TSE cases.
Christina Sigurdson, Markus Glatzel, and Adriano Aguzzi
Institute of Neuropathology
University Hospital of Zurich
Zurich, Switzerland
References
1 Glatzel M, Abela E, et al: Extraneural pathologic prion
protein in sporadic Creutzfeldt-Jakob disease. N Engl J
Med 349(19):1812-1820, 2003
2 Kovacs GG, Lindeck-Pozza E, et al: Creutzfeldt-Jakob
disease and inclusion body myositis: abundant diseaseassociated
prion protein in muscle. Ann Neurol 55(1):
121-125, 2004
3 Wadsworth JDF, Joiner S, et al: Tissue distribution of protease
resistant prion protein in variant CJD using a highly
sensitive immuno-blotting assay. Lancet 358:171-180,
2001
===================================
Corinna Kaarlela, News Director Source: Jennifer O'Brien jobrien@pubaff.ucsf.edu 415-476-2557 14 February 2005
Diagnosis of prions in patients should utilize novel strategy, team says
A technique for detecting prions in tissue, developed in recent years by UCSF scientists, is significantly more sensitive than the diagnostic procedures currently used to detect the lethal particles in samples of brain tissue from patients, according to a study performed by a UCSF team.
The finding indicates that the diagnostic technique, known as the conformation-dependent immunoassay (CDI), should be established as the standard approach for brain biopsies of patients suspected of having the disease, they say. The team is exploring whether the CDI might be adapted to detect prions in blood and muscle.
The finding suggests that reliance on the current methods for detecting prions in human brain tissue -- microscopic examination of tissue for the telltale vacuoles that form in brain cells and immunohistochemistry (IHC), which involves detecting prions in brain sections using prion protein-specific antibodies -- may have led to an under diagnosis of the disease in patients in recent years, they say. (A definitive diagnosis of the disease in humans is made only on autopsy, when a neuropathologist can analyze multiple brain regions for vacuoles and evidence of prions by IHC, and it is estimated that only 50 percent of human cases are autopsied, in part because many pathologists do not want to risk infection during the autopsy.)
In the study, the team compared the ability of the CDI and the two traditional diagnostic techniques to detect prions in various brain samples from 28 patients diagnosed on autopsy as having one of several human forms of the disease -- sporadic, familial or iatrogenic Creutzfeldt-Jakob disease (CJD). While the CDI detected the biochemical signal for prions in 100 percent of the samples studied, the traditional tests failed to detect the prion in a high proportion of cases. For example, in an experiment that focused on 18 brain regions from eight patients with sporadic CJD, the CDI detected prions in 100 percent of the samples, while IHC detected them in 22 percent and routine tissue examination in 17 percent.
"In about 80 percent of the different brain regions examined, prions were not consistently detected by either IHC or routine histology that measure vacuolation. In contrast, the CDI was always positive in all regions of the brain," says the lead author of the study, Jiri Safar, MD, associate adjunct professor of neurology and a member of the UCSF Institute for Neurodegenerative Diseases, which is directed by senior author Stanley B. Prusiner, MD, UCSF professor of neurology and biochemistry.
"These findings indicate that histology and immunohistochemistry should no longer be used to rule out prion disease in single-site biopsy samples," says Safar. "The superior performance of the CDI in diagnosing prion disease suggests that the CDI be used in future diagnostic evaluations of prion disease, particularly for single-site brain biopsies during life"
"If the traditional techniques are used at autopsy, they must be applied to many cortical and subcortical samples," says co-author Stephen J. DeArmond, MD, PhD, UCSF professor of neuropathology.
Moreover, while the study examined the efficacy of the CDI in comparison to the two techniques routinely used by neuropathologists to detect prions in human brain tissue, previous studies at UCSF indicate that the CDI is also significantly more sensitive than Western blot analysis, the technology used with IHC to detect prions in brain tissue from cattle suspected of having bovine spongiform encephalopathy (BSE). That IHC and Western blot analysis are relatively insensitive methods, the researchers say, supports their ongoing assertion that the CDI should also be used to evaluate the brain tissue of cattle.
"The studies reported here are likely to change profoundly the approach to the diagnosis of prion disease in both humans and livestock," says Safar.
More broadly, the scientists say, the high sensitivity of the CDI suggests that CDI-like tests could also prove useful for diagnosing other neurodegenerative diseases, such as Alzheimer's disease, Parkinsons's disease and fronto-temporal dementias, all of which, like prion diseases, involve various forms of protein misprocessing. These diseases currently are diagnosed by neuropathological analysis and immunohistochemistry.
"Whether immunohistochemistry underestimates the incidence of one or more of these common neurodegenerative diseases is unknown, but the CDI could shed light on these diseases," says co-author Bruce Miller, MD, UCSF A.W. and Mary Margaret Clausen Distinguished Professor of Neurology and director of the UCSF Memory and Aging Center.
The finding will be printed on-line and in print on March 1, 2005 in Proceedings of the National Academy of Sciences.
The study brings into high relief the different detection strategies of immunohistochemistry and the CDI, both of which involve revealing the presence of prions, known as PrPsc, by applying antibodies to brain tissue.
Standard immunohistochemistry, developed in the DeArmond lab 20 years ago, involves using an enzyme known as a protease, or a combination of harsh acid and high temperature treatment, to destroy normal prion protein (PrPC), which is ubiquitous in brain tissue. Once this occurs, scientists apply fluorescently lit antibodies that react with residues of the relatively resistant abnormal prion protein (PrPSc), thereby highlighting it.
The limitation of this technique is that scientists have since learned that there is a large part of the abnormal prion protein that is protease sensitive, and that portion escapes detection by the standard technique. Thus, this traditional method underestimates the level of PrPSc in tissue.
The CDI addresses this limitation by revealing the region of PrPSc that is exposed in the normal PrPC but is buried in infectious PrPSc, using high affinity, newly generated antibodies that identify PrPSc through the distinct shape of the molecule, independent of proteolytic treatments. This makes it possible to detect potentially large concentrations of protease sensitive PrPSc molecules.
Detractors would say that it is not necessary to detect the minute level of infectious agent that the CDI is capable of revealing, as it would be unlikely to be lethal, says Safar. But Prusiner and his colleagues maintain that any risk is too great when it comes to having prions in the food supply. In addition, because even low levels of prions are extremely resistant to inactivation, they may contaminate the environment for many years.
Prusiner won the 1997 Nobel Prize in Physiology or Medicine for discovering that a class of neurodegenerative diseases known as spongiform encephalopathies was caused by prions. Prion diseases develop in humans, cattle, sheep, deer, elk and mink.
The CDI was developed by members of the Prusiner lab. The CDI methodology has been licensed to InPro Biotechnology, Inc.
Prusiner, Safar, DeArmond and other members of the Institute for Neurodegenerative Diseases are scientific advisors to, or own stock in, InPro.
Other co-authors of the study were Michael D. Geschwind, Camille Deering, Svetlana Didorenko, Mamta Sattavat, Henry Sanchesz, Ana Serban, Kurt Giles, of UCSF, and Martin Vey, of Behring, Marburg, Germany, and Henry Baron, of Behring, Paris.
The study was funded by the National Institutes of Health, the John Douglas French Foundation for Alzheimer's research, the McBean Foundation, the State of California, Alzheimer's Disease Research Center of California and the RR00079 General Clinical Research Center.
The UCSF Institute for Neurodegenerative Diseases: http://ind.medschool.ucsf.edu/.
FURTHER COMPARISON OF THE CDI TO THE STANDARD DIAGNOSTIC PROCEDURES, PROVIDED BY STEPHEN J. DEARMOND, MD, PHD, UCSF PROFESSORS OF NEUROPATHOLOGY:
Explanation as to why the CDI is more sensitive than Western blot analysis: Studies at UCSF during development of the CDI showed that CDI could detect prions in brain homogenates at levels that fail to produce disease in animals (bioassay for prions). Therefore, the CDI is more sensitive than the bioassay method, which was considered to be the most sensitive technique for detecting prions. In contrast, Western blot analysis for prions is significantly less sensitive than the bioassay and is, therefore, significantly less sensitive than the CDI. Currently, the USDA uses a combination of Western blot analysis of brainstem homogenates and immunohistochemistry of the medulla to test cattle suspected of having bovine spongiform encephalopathy ("mad cow disease"). The relative insensitivity of IHC and Western blot analysis, says DeArmond, supports the UCSF scientists' ongoing assertion that the CDI should also be used to evaluate the brain tissue of cattle.
DeArmond cites additional evidence about Western blot analysis from a World Health Organization (WHO) study group, which compared the CDI method with Western blots for detection of prions in sporadic and variant CJD brains. Based on the smallest amount of prions that could detected by the two techniques, they found that the CDI was from 1000- to 100,000-fold more sensitive than Western blot analysis performed in six different research laboratories (Minor et al. Standards for the assay of Creutzfeldt-Jakob disease specimens. J. Gen. Virol. 85: 1777-1784, 2004).
Explanation as to why IHC for prions is less sensitive than the CDI: IHC is routinely performed on formalin-fixed, paraffin-embedded samples of brain. Formalin fixation markedly decreases the ability of antibodies to bind to proteins in general, which greatly weakens the IHC signal for prions (PrPSc). In contrast, homogenates for the CDI are not treated with reagents that decrease prion antigenicity. Moreover, to concentrate the PrPSc for measurement by the CDI, the homogenates are exposed to phosphotungstic acid, which selectively precipitates both protease-sensitive and protease-resistant PrPSc that comprise prions, but not the normal prion protein conformer found in uninfected animals, PrPC. This step results in a higher concentration of PrPSc for detection by the CDI. Because the PrPSc was not exposed to proteases, the CDI measures all forms of abnormally folded PrPSc molecules. Protease-sensitive PrPSc can account for 50 percent of the total PrPSc. For Western analysis, homogenates of brain are treated with protease to eliminate PrPC; however, this step also eliminates protease-sensitive PrPSc leaving only protease-resistant PrPSc for Western blot detection and decreasing the PrPSc signal at least in half.
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http://pub.ucsf.edu/newsservices/releases/200502147/
PNAS March 1, 2005 vol. 102 no. 9 3501-3506
NEUROSCIENCE
Diagnosis of human prion disease
Jiri G. Safar *, , Michael D. Geschwind , , Camille Deering *, Svetlana Didorenko *, Mamta Sattavat , Henry Sanchez , Ana Serban * , Martin Vey , Henry Baron **, Kurt Giles *, , Bruce L. Miller , , Stephen J. DeArmond * , and Stanley B. Prusiner *, , ,
*Institute for Neurodegenerative Diseases, Memory and Aging Center, and Departments of Neurology, Pathology, and Biochemistry and Biophysics, University of California, San Francisco, CA 94143; ZLB Behring, 35041 Marburg, Germany; and **ZLB Behring, 75601 Paris, France
Contributed by Stanley B. Prusiner, December 22, 2004
Abstract
With the discovery of the prion protein (PrP), immunodiagnostic procedures were applied to diagnose Creutzfeldt-Jakob disease (CJD). Before development of the conformation-dependent immunoassay (CDI), all immunoassays for the disease-causing PrP isoform (PrPSc) used limited proteolysis to digest the precursor cellular PrP (PrPC). Because the CDI is the only immunoassay that measures both the protease-resistant and protease-sensitive forms of PrPSc, we used the CDI to diagnose human prion disease. The CDI gave a positive signal for PrPSc in all 10-24 brain regions (100%) examined from 28 CJD patients. A subset of 18 brain regions from 8 patients with sporadic CJD (sCJD) was examined by histology, immunohistochemistry (IHC), and the CDI. Three of the 18 regions (17%) were consistently positive by histology and 4 of 18 (22%) by IHC for the 8 sCJD patients. In contrast, the CDI was positive in all 18 regions (100%) for all 8 sCJD patients. In both gray and white matter, 90% of the total PrPSc was protease-sensitive and, thus, would have been degraded by procedures using proteases to eliminate PrPC. Our findings argue that the CDI should be used to establish or rule out the diagnosis of prion disease when a small number of samples is available as is the case with brain biopsy. Moreover, IHC should not be used as the standard against which all other immunodiagnostic techniques are compared because an immunoassay, such as the CDI, is substantially more sensitive.
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Discussion
The clinical diagnosis of human prion disease is often difficult until the patient shows profound signs of neurologic dysfunction. It is widely accepted that the clinical diagnosis must be provisional until a tissue diagnosis either confirms or rules out the clinical assessment. Before the availability of Abs to PrP, a tissue diagnosis was generally made by histologic evaluation of neuropil vacuolation. IHC with anti-glial-fibrillary-acidic-protein Abs in combination with H&E staining preceded the use of anti-PrP Ab staining.
Recently, the role of IHC in the diagnosis of scrapie in the brains of eight clinically affected goats inoculated with the SSBP1 prion isolate has been challenged (14). Thalamic samples taken from seven of eight goats with scrapie were positive for PrPSc by Western blotting but negative by IHC. The eighth goat was negative by Western blotting and IHC. Consistent with these findings in goats are the data reported here, in which IHC of formalin-fixed, paraffin-embedded human brain samples was substantially less sensitive than the CDI.
The CDI was developed to quantify PrPSc in tissue samples from mammals producing prions. Concerned that limited PK digestion was hydrolyzing some or even most of the PrPSc, we developed a CDI that does not require PK digestion. The CDI revealed that as much as 90% of PrPSc is sPrPSc; thus, it was being destroyed during limited proteolytic digestion used to hydrolyze PrPC. sPrPSc comprises 80% of PrPSc in the frontal lobe and in the white matter (Fig. 4).
The CDI detected HuPrPSc with a sensitivity comparable to the bioassay for prion infectivity in Tg(MHu2M) mice (Fig. 1). The high sensitivity achieved by the CDI is due to several factors (8, 10, 11, 15). First, both sPrPSc and rPrPSc conformers are specifically precipitated by PTA (Table 5) (8, 9). PTA has also been used to increase the sensitivity of Western blots enabling the detection of rPrPSc in human muscle and other peripheral tissues (16, 17). Second, a sandwich protocol was used with the high-affinity MAR1 mAb (11) to capture HuPrPSc and Eu-labeled 3F4 mAb to detect HuPrPSc (12). Third, the CDI detects PrPSc by Ab-binding to native and denatured forms of the protein and, therefore, does not depend on proteolytic degradation of PrPC. We chose not to perform Western blots on most of the samples used in this study because such immunoblots require denaturation of the sample, which eliminates measurement of the native signal corresponding to PrPC (Table 5). Moreover, a comparison between the CDI and Western blotting on brain samples from sCJD and variant CJD patients showed that the CDI was 50- to 100-fold more sensitive (15). Additionally, Western blots combined with densitometry are linear over a 10- to 100-fold range of concentrations, whereas the CDI is linear over a >104-fold range. The CDI has been automated, which not only improves accuracy and reproducibility (10) but also allows numerous samples to be analyzed, as reported here. Western blots are difficult to automate and are labor intensive.
Our studies show that only the CDI detected PrPSc in all regions examined in 24 sCJD and 3 fCJD(E200K) brains (Figs. 2 and 6). Comparative analyses demonstrated that the CDI was vastly superior to histology and IHC. When 18 regions of 8 sCJD and 2 fCJD(E200K) brains were compared, we discovered that histology and IHC were unreliable diagnostic tools except for samples from a few brain regions. In contrast, the CDI was a superb diagnostic procedure because it detected PrPSc in all 18 regions in 8 of 8 sCJD and 2 of 2 fCJD(E200K) cases (Tables 1 and 2).
Histologic changes in prion disease have been shown to follow the accumulation of prions as measured by bioassay of infectivity and by PrPSc accumulation (18-22). Because low levels of PrPSc are not associated with neuropathologic changes, some discrepancy between vacuolation and PrPSc was expected. In contrast to histology, IHC measures PrP immunostaining after autoclaving tissue sections exposed to formic acid. Because IHC measures PrP, we expected the sensitivity of this procedure might be similar to the CDI, but that proved not to be the case. Whether exposure of formic acid-treated tissue sections to elevated temperature destroys not only PrPC but also sPrPSc and only denatures rPrPSc remains to be determined. Such a scenario could account for the lower sensitivity of IHC compared with CDI or bioassay (Tables 1 and 2).
Studies of the white matter in CJD brains were particularly informative with respect to the sensitivity of the CDI, where PrPSc levels were low but readily detectable, 10- to 100-fold above the threshold value (Fig. 4). Because animal studies have shown that PrPSc and infectivity are transported anterogradely from one brain region to another along neuroanatomical pathways (23-25), we expected to find PrPSc in white matter as demonstrated by the CDI but not IHC. Axonal transport of PrPSc is also suggested by diffusion-weighted MRI scans of CJD cases, which show high-intensity signals in analogous neocortical regions of the right and left cerebral hemispheres (26). This symmetry of neuroradiological abnormalities is consistent with spread of PrPSc to the contralateral cortex by means of callosal commissural pathways.
Most immunoassays that detect HuPrPSc do so only after subjecting the sample to limited proteolysis to form PrP 27-30, followed by denaturation. Because the CDI measures the immunoreactivity before and after denaturation to an epitope that is exposed in native PrPC but buried in PrPSc, limited proteolysis to eliminate PrPC is unnecessary. Assays based on limited proteolysis underestimate the level of PrPSc because they digest sPrPSc, which represents 80-90% of PrPSc in CJD and scrapie brains (Fig. 4 and Table 5).
Gerstmann-Sträussler-Scheinker, an inherited human prion disease, is caused by the P102L mutation in the PRNP gene. In mice expressing the Gerstmann-Sträussler-Scheinker mutant PrP transgene, the CDI detected high levels of sPrPSc(P101L) as well as low levels of rPrPSc(P101L) long before neurodegeneration and clinical symptoms occurred (9). sPrPSc(P101L) as well as low concentrations of rPrPSc(P101L) previously escaped detection (27). Whether a similar situation applies in other genetic forms of prion disease, sCJD, or variant CJD remains to be determined. Because most of the PrPSc in the brains of sCJD patients is protease-sensitive (Fig. 4), it is likely that the lower sensitivity of IHC is due to its inability to detect sPrPSc. Presently, we have no information about the kinetics of either sPrPSc or rPrPSc accumulation in human brain. Limited information on the kinetics of PrPSc accumulation in livestock comes from studies of cattle, sheep, and goats inoculated orally, but most of the bioassays were performed in non-Tg mice (28-30) in which prion titers were underestimated by as much as a factor of 104 (10).
The studies reported here are likely to change profoundly the approach to the diagnosis of prion disease in both humans and livestock (31-33). The superior performance of the CDI in diagnosing prion disease compared to routine neuropathologic examination and IHC demands that the CDI be used in future diagnostic evaluations of prion disease. Prion disease can no longer be ruled out by routine histology or IHC. Moreover, the use of IHC to confirm cases of bovine spongiform encephalopathy after detection of bovine PrPSc by the CDI (10) seems an untenable approach in the future. Clearly, the CDI for HuPrPSc is as sensitive or more sensitive than bioassays in Tg(MHu2M) mice (Fig. 1).
Our results suggest that using the CDI to test large numbers of samples for human prions might alter the epidemiology of prion diseases. At present, there is limited data on the frequency of subclinical variant CJD infections in the U.K. population (34). Because appendixes and tonsils were evaluated only by IHC, many cases might have escaped detection (Tables 1 and 2). Equally important may be the use of CDI-like tests to diagnose other neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and the frontotemporal dementias. Whether IHC underestimates the incidence of one or more of these common degenerative diseases is unknown. Moreover, CDI-like tests may help determine the frequency with which these disorders and the prion diseases occurs concomitantly in a single patient (35, 36).
Acknowledgements
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http://www.pnas.org/
Volume 349:1812-1820 November 6, 2003 Number 19
Extraneural Pathologic Prion Protein in Sporadic Creutzfeldt-Jakob Disease
Background In patients with sporadic Creutzfeldt-Jakob disease, pathologic disease-associated prion protein (PrPSc) has been identified only in the central nervous system and olfactory-nerve tissue. Understanding the distribution of PrPSc in Creutzfeldt-Jakob disease is important for classification and diagnosis and perhaps even for prevention.
Methods We used a highly sensitive method of detection - involving the concentration of PrPSc by differential precipitation with sodium phosphotungstic acid, which increased the sensitivity of Western blot analysis by up to three orders of magnitude - to search for PrPSc in extraneural organs of 36 patients with sporadic Creutzfeldt-Jakob disease who died between 1996 and 2002.
Results PrPSc was present in the brain tissue of all patients. In addition, we found PrPSc in 10 of 28 spleen specimens and in 8 of 32 skeletal-muscle samples. Three patients had PrPSc in both spleen and muscle specimens. Patients with extraneural PrPSc had a significantly longer duration of disease and were more likely to have uncommon molecular variants of sporadic Creutzfeldt-Jakob disease than were patients without extraneural PrPSc.
Conclusions Using sensitive techniques, we identified extraneural deposition of PrPSc in spleen and muscle samples from approximately one third of patients who died with sporadic Creutzfeldt-Jakob disease. Extraneural PrPSc appears to correlate with a long duration of disease.
Source Information
From the Institute of Neuropathology and National Reference Center for Prion Diseases, University Hospital of Zurich, Zurich, Switzerland.
Dr. Glatzel and Mr. Abela contributed equally to the article.
Address reprint requests to Dr. Aguzzi at the Institute of Neuropathology, University Hospital of Zurich, Schmelzbergstr. 12, CH-8091 Zurich, Switzerland, or at adriano@pathol.unizh.ch .
http://content.nejm.org/cgi/
Creutzfeldt-Jakob disease and inclusion body myositis: Abundant disease-associated prion protein in muscle
Gabor G. Kovacs, MD PhD 1 2, Elisabeth Lindeck-Pozza, MD 1, Leila Chimelli, MD, PhD 3, Abelardo Q. C. Araújo, MD, PhD 4, Alberto A. Gabbai, MD, PhD 5, Thomas Ströbel, PhD 1, Markus Glatzel, MD 6, Adriano Aguzzi, MD, PhD 6, Herbert Budka, MD 1 * 1Institute of Neurology, University of Vienna, and Austrian Reference Centre for Human Prion Diseases, Vienna, Austria 2National Institute of Psychiatry and Neurology, Budapest, Hungary 3Department of Pathology, School of Medicine, Federal University of Rio de Janeiro 4Department of Neurology, School of Medicine, Federal University of Rio de Janeiro 5Department of Neurology, School of Medicine, Federal University of Sao Paulo, Brazil 6Institute of Neuropathology, University Hospital of Zürich, Zürich, Switzerland email: Herbert Budka (h.budka@akh-wien.ac.at )
*Correspondence to Herbert Budka, Institute of Neurology, AKH 4J, Wühringer Gürtel 18-20, POB 48, A-1097 Vienna, Austria
Funded by: European Union (EU) Project; Grant Number: TSELAB QLK2-CT-2002-81523 EU Concerted Action PRIONET; Grant Number: QLK2-2000-CT-00837
Abstract
Pathologicalprion protein (PrPSc) is the hallmark of prion diseases affecting primarily the central nervous system. Using immunohistochemistry, paraffin-embedded tissue blot, and Western blot, we demonstrated abundant PrPSc in the muscle of a patient with sporadic Creutzfeldt-Jakob disease and inclusion body myositis. Extraneural PrPC-PrPSc conversion in Creutzfeldt-Jakob disease appears to become prominent when PrPC is abundantly available as substrate, as in inclusion body myositis muscle.
--------------
Received: 16 June 2003; Revised: 11 September 2003; Accepted: 11 September 2003 Digital Object Identifier (DOI)
10.1002/ana.10813 About DOI
http://www3.interscience.wiley.com/
AS Professor Aguzzi kindly put it most recently ;
107 Vet Pathol 42:107 108 (2005) Letters to the Editor Editor: Absence of evidence is not always evidence of absence. In the article Failure to detect prion protein (PrPres) by immunohistochemistry in striated muscle tissues of animals experimentally inoculated with agents of transmissible spongiform encephalopathy, recently published in Veterinary Pathology (41:78 81, 2004), PrPres was not detected in striated muscle of experimentally infected elk, cattle, sheep, and raccoons by immunohistochemistry (IHC). Negative IHC, however, does not exclude the presence of PrPSc. For example, PrPres was detected in skeletal muscle in 8 of 32 humans with the prion disease, sporadic Creutzfeldt-Jakob disease (CJD), using sodium phosphotungstic acid (NaPTA) precipitation and western blot.1 The NaPTA precipitation, described by Wadsworth et al.,3 concentrates the abnormal isoform of the prion, PrPres, from a large tissue homogenate volume before western blotting. This technique has increased the sensitivity of the western blot up to three orders of magnitude and could be included in assays to detect PrPres. Extremely conspicuous deposits of PrPres in muscle were detected by IHC in a recent case report of an individual with inclusion body myositis and CJD.2 Here, PrPres was detected in the muscle by immunoblotting, IHC, and paraf- fin-embedded tissue blot. We would therefore caution that, in addition to IHC, highly sensitive biochemical assays and bioassays of muscle are needed to assess the presence or absence of prions from muscle in experimental and natural TSE cases.
Christina Sigurdson, Markus Glatzel, and Adriano Aguzzi Institute of Neuropathology University Hospital of Zurich Zurich, Switzerland References 1 Glatzel M, Abela E, et al: Extraneural pathologic prion protein in sporadic Creutzfeldt-Jakob disease. N Engl J Med 349(19):1812 1820, 2003 2 Kovacs GG, Lindeck-Pozza E, et al: Creutzfeldt-Jakob disease and inclusion body myositis: abundant diseaseassociated prion protein in muscle. Ann Neurol 55(1): 121 125, 2004 3 Wadsworth JDF, Joiner S, et al: Tissue distribution of protease resistant prion protein in variant CJD using a highly sensitive immuno-blotting assay. Lancet 358:171 180, 2001...///
EMBO reports AOP Published online: 11 April 2003
Widespread PrPSc accumulation in muscles of hamsters orally infected with scrapie
http://www.emboreports.org/
Watson Meldrum et al Scrapie agent in muscle - Pattison I A (1990) Veterinary record, 20 January 1990. p.68
http://www.bseinquiry.gov.uk/files/yb/1990/01/19009001.pdf
===============================
GREETINGS AGAIN APHIS ET AL,
FURTHERMORE, WE HAVE FAILED TO EVEN STOP THE SRMs FROM WHOLE CUTS OF BONELESS BEEF IMPORTED FROM CANADA IN THE VERY ONSET OF THE NEW BSE MRR (MINIMAL RISK REGION). THIS IS THE VERY REASON I HAVE SAID TIME AND TIME AGAIN THAT BY THIS ADMINISTRATION ABANDONING THE BSE GBR RISK ASSESSMENTS BECAUSE THEY DID NOT LIKE THE ASSESSMENT OF BSE GBR III, AND ADHERING TO A NEW BSE MRR POLICY THAT WAS DESIGNED NOT FOR HUMAN HEALTH, BUT ONLY FOR COMMODITIES AND FUTURES, WILL FURTHER EXPOSE NEEDLESSLY MILLIONS AND MILLIONS OF HUMANS AND ANIMALS VIA THE FREE TRADING OF ALL STRAINS OF TSE GLOBALLY. references as follow ;
Wisconsin Firm Recalls Beef Products
Recall Release CLASS II RECALL FSIS-RC-032-2005 HEALTH RISK: LOW
Congressional and Public Affairs (202) 720-9113 Steven Cohen
WASHINGTON, Aug. 19, 2005 - Green Bay Dressed Beef, a Green Bay, Wis., establishment, is voluntarily recalling approximately 1,856 pounds of beef products that may contain portions of the backbone from a cow just over 30 months old, the U.S. Department of Agriculture's Food Safety and Inspection Service announced today. The product was from a cow imported directly for slaughter from Canada.
Based on information provided by Canada, the products subject to this Class II recall are from a cow that is approximately one month older than the 30-month age limit. Both ante-mortem and post-mortem inspection were done on the cow in question. FSIS inspection program personnel determined the cow to be healthy and fit for human food. FSIS' designation of this recall as Class II is because it is a situation where there is a remote probability of adverse health consequences from the use of the product.
FSIS learned about this as a result of a Canadian audit of their health certificate that accompanied the imported cow. Prior to slaughter, the health certificate accompanying the cow was presented to the establishment, and it appeared complete and accurate. However, a subsequent audit of information related to the health certificate by Canadian officials found that it was not accurate. Action has been taken by Canadian Food Inspection Agency officials in response to findings from the audit.
The products subject to recall are: Five boxes of 243 lb. vacuum pouched packages of "American Foods Group, NECKBONE UNTRIM'D, USDA CHOICE OR HIGHER" with the case code of 77333; One box of 50 lb. vacuum pouched package of "American Foods Group, SHORTLOIN 2X2, USDA SELECT OR HIGHER" with the case code of 75231; One box of 60 lb. vacuum pouched package of "American Foods Group, SHORTLOIN 2X2, USDA CHOICE OR HIGHER" with the case code of 75060; Five boxes of 258 lb. vacuum pouched packages of "Dakota Supreme Beef, SHORTLOIN 0X11/4, USDA SELECT OR HIGHER" with the case code of 75442; Sixteen boxes of 811 lb. vacuum pouched packages of "American Foods Group, BLADE BI N/O CHUCK, USDA CHOICE OR HIGHER" with the case code of 75955; Nine boxes of 435 lb. vacuum pouched packages of "American Foods Group, BLADE BI N/O CHUCK, USDA SELECT OR HIGHER" with the case code of 75952.
Each box bears the establishment number "410" inside the USDA seal of inspection. The products were produced on August 4, and were distributed to wholesale distributors in Pennsylvania, Florida, Illinois, Maryland, Minnesota and Wisconsin.
Under the interim final rules FSIS implemented on January 12, 2004, certain specified risk materials must be removed from all cattle depending on the age of the animal. On this animal all specified risk materials for cattle 30 months and over were removed, with the exception of the vertebral column. At the time of slaughter, the animal was certified to be under 30 months of age and removal of the vertebral column was not required. A subsequent audit determined the animal was just over 30 months of age; therefore, the vertebral column is required to be removed. This is the reason for the recall of the selected products.
Consumers with questions about the recall may contact Sally VandeHei, Executive Assistant at 1-877-894-3927. National media with questions may contact Jim Mulhern at (202) 496-2468. Local media with questions may contact Susan Finco at (920) 965-7750 ext.158.
Consumers with other food safety questions can phone the toll-free USDA Meat and Poultry Hotline at 1-888-MPHotline (1-888-674-6854). The hotline is available in English and Spanish and can be reached from 10 a.m. to 4 p.m. (Eastern Time), Monday through Friday. Recorded food safety messages are available 24 hours a day. Sample Product Labels: These are similar to, but not identical to, labels on the recalled product.
#
USDA Recall Classifications Class I This is a health hazard situation where there is a reasonable probability that the use of the product will cause serious, adverse health consequences or death. Class II This is a health hazard situation where there is a remote probability of adverse health consequences from the use of the product. Class III This is a situation where the use of the product will not cause adverse health consequences.
http://www.fsis.usda.gov/News_&_Events/Recall_032_2005_Release/index.asp
:
Docket No. 03-080-1 -- USDA ISSUES PROPOSED RULE TO ALLOW LIVE ANIMAL IMPORTS FROM CANADA [TSS SUBMISSION 11/03/2003 01:19 PM To: regulations@aphis.usda.gov ]
https://web01.aphis.usda.gov/BSEcom.nsf/0/b78ba677e2b0c12185256dd300649f9d?OpenDocument&AutoFramed
THE BSE MRR POLICY SHOULD BE ABOLISHED/REPEALED IMMEDIATELY AND THE BSE GBR RISK ASSESSMENTS AND POLICY SHOULD BE STRICTLY ENFORCED AND FURTHER ENHANCED TO INCLUDE CWD AND ALL TSEs...TSS
EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA) Publication date: 20 August 2004 Adopted July 2004 (Question N° EFSA-Q-2003-083)
Report
Summary Summary of the Scientific Report
The European Food Safety Authority and its Scientific Expert Working Group on the Assessment of the Geographical Bovine Spongiform Encephalopathy (BSE) Risk (GBR) were asked by the European Commission (EC) to provide an up-to-date scientific report on the GBR in the United States of America, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in USA. This scientific report addresses the GBR of USA as assessed in 2004 based on data covering the period 1980-2003.
The BSE agent was probably imported into USA and could have reached domestic cattle in the middle of the eighties. These cattle imported in the mid eighties could have been rendered in the late eighties and therefore led to an internal challenge in the early nineties. It is possible that imported meat and bone meal (MBM) into the USA reached domestic cattle and leads to an internal challenge in the early nineties.
A processing risk developed in the late 80s/early 90s when cattle imports from BSE risk countries were slaughtered or died and were processed (partly) into feed, together with some imports of MBM. This risk continued to exist, and grew significantly in the mid 90's when domestic cattle, infected by imported MBM, reached processing. Given the low stability of the system, the risk increased over the years with continued imports of cattle and MBM from BSE risk countries.
EFSA concludes that the current GBR level of USA is III, i.e. it is likely but not confirmed that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. As long as there are no significant changes in rendering or feeding, the stability remains extremely/very unstable. Thus, the probability of cattle to be (pre-clinically or clinically) infected with the BSE-agent persistently increases.
http://www.efsa.eu.int/science/efsa_scientific_reports/gbr_assessments/573_en.html
From: Terry S. Singeltary Sr. [flounder@wt.net] Sent: Tuesday, July 29, 2003 1:03 PM To: fdadockets@oc.fda.gov Cc: ggraber@cvm.fda.gov; Linda.Grassie@fda.gov; BSE-L Subject: Docket No. 2003N-0312 Animal Feed Safety System [TSS SUBMISSION TO DOCKET 2003N-0312]
Greetings FDA,
snip...
PLUS, if the USA continues to flagrantly ignore the _documented_ science to date about the known TSEs in the USA (let alone the undocumented TSEs in cattle), it is my opinion, every other Country that is dealing with BSE/TSE should boycott the USA and demand that the SSC reclassify the USA BSE GBR II risk assessment to BSE/TSE GBR III 'IMMEDIATELY'. for the SSC to _flounder_ any longer on this issue, should also be regarded with great suspicion as well. NOT to leave out the OIE and it's terribly flawed system of disease surveillance. the OIE should make a move on CWD in the USA, and make a risk assessment on this as a threat to human health. the OIE should also change the mathematical formula for testing of disease. this (in my opinion and others) is terribly flawed as well. to think that a sample survey of 400 or so cattle in a population of 100 million, to think this will find anything, especially after seeing how many TSE tests it took Italy and other Countries to find 1 case of BSE (1 million rapid TSE test in less than 2 years, to find 102 BSE cases), should be proof enough to make drastic changes of this system. the OIE criteria for BSE Country classification and it's interpretation is very problematic. a text that is suppose to give guidelines, but is not understandable, cannot be considered satisfactory. the OIE told me 2 years ago that they were concerned with CWD, but said any changes might take years. well, two years have come and gone, and no change in relations with CWD as a human health risk. if we wait for politics and science to finally make this connection, we very well may die before any decisions or changes are made. this is not acceptable. we must take the politics and the industry out of any final decisions of the Scientific community. this has been the problem from day one with this environmental man made death sentence. some of you may think i am exaggerating, but you only have to see it once, you only have to watch a loved one die from this one time, and you will never forget, OR forgive...yes, i am still very angry... but the transmission studies DO NOT lie, only the politicians and the industry do... and they are still lying to this day...TSS
http://www.fda.gov/ohrms/dockets/dockets/03n0312/03N-0312_emc-000001.txt
GREETINGS AGAIN APHIS ET AL,
Moving on to the theory that BSE agent is not in blood. THIS is what they use to think with nvCJD. However the nvCJD agent has now been detected and transmitted the TSE agent by blood. nvCJD is the BSE agent that has transmitted to humans. nvCJD is human BSE. so if nvCJD transmits by blood, why not BSE? with the limited testing to date, the limited sensitivity of the detection of the BSE/TSE agent blood to date, i would not be so sure that the BSE/TSE agent does not transmit by blood. just recent Ag. Comm. Johanns stated that they would not address the blood issue being fed to cattle. a foolish and careless mistake. but typical. we now have detected new atypical strains of the BSE/TSE agent in cattle in many countries i.e. Japan, France, Belgium, Germany, and Italy. In the Italian study of BASE, a new? TSE in cattle they have discovered that is not like the nvCJD, but very similar to sporadic CJD. They have detected 2 such cattle at printing of this study March 2, 2004. Identification of a second bovine amyloidotic spongiform encephalopathy: Molecular similarities with sporadic Creutzfeldt-Jakob disease PNAS. MY point is that with these new atypical TSEs showing up in cattle, sheep and goats, we don't know if blood and other tissues transmits the disease. THE SRM list may and should be reevaluated. WE know BSE is in the USA, but we also know that in the studies of Mission Texas, where USA suffolk scrapie sheep were inoculated into USA cattle, the PRION agent that was produced did not look like the UK BSE strain. so why would all CJD cases in the USA look like the UK human BSE i.e. nv/v CJD? WHY wait and expose millions and millions needlessly as in the past with previous TSE blunders, why wait to act. why not act first with what we know, which is very concerning, then as science evolves, go from there. references as follow ;
UK Strategy for Research and
Development on Human and Animal
Health Aspects of Transmissible
Spongiform Encephalopathies
2005-2008
snip...
3.2 Tackling the spread of infection
3.2.1 The species barrier and the carrier state
3.2.1.1 The possibility of 'carrier' states in animals and humans, and our present inability
to identify them, pose a potential threat to public and animal health. The susceptibility of
humans to BSE infection, and the ability of the disease to remain clinically silent for
many years, is of major concern to DH. Although the death of a UK blood donor from
vCJD in 1999 three years after making the donation and the subsequent death from vCJD
of the recipient in 2003 have not been causally linked, transmission of infection through
blood transfusion is the most likely explanation327. The case heightens concerns that
'carriers' could be transmitting the disease through blood, tissue and organ donation or
by contaminating surgical instruments when undergoing surgery. DH will continue to
support research to detect infectious prions in human tissue, to investigate the
decontamination of surgical instruments and to develop measures to protect blood
supplies.
3.2.1.2 Animal models of some TSEs have detected infectivity in blood. Experiments,
which have involved transfusing large volumes of blood from infected sheep to healthy
recipient sheep, have demonstrated that infectivity can be transmitted by blood
transfusion. A central part of DH policy in this area has been the leucodepletion of blood
donations and the efficacy of this technology can now be tested in sheep.
snip...
4.5.4 In 1987, epidemiological studies of BSE cases identified meat and bone meal as the
probable means by which the disease was being spread. In an attempt to prevent
further infections a ban on incorporating ruminant protein in ruminant feed was
introduced in July 1988. Due to the long incubation period associated with this disease
the efficacy of this control measure was not immediately apparent. As time passed it
became clear from the number of cases born after the ban that it was not wholly
effective.
4.5.5 Epidemiological analysis of these cases showed that a high proportion of them
occurred in areas where the pig population was high. This observation, coupled with
research data that showed that only a very small dose of the infective material was
needed to cause disease in cattle, led to the conclusion that cross-contamination of feed
was occurring.
4.5.6 Since 1988, increasingly stringent feed controls have been put in place. Key
amongst these have been:
o the ban on the use of specified bovine offal in all animal feed (September 1990);
o the ban on feeding any farmed animal, including horses and fish, with mammalian
meat and bone meal. (This began in March 1996 but following this ban there was
a recall scheme and the date from which the ban was considered to be fully
effective is regarded as being 1 August 1996);
62
v6.1
o EU-wide controls on feed which extended the ban to include all processed animal
protein, including that derived from birds and fish (implemented in the UK from 1
August 2001).
4.5.7 As illustrated in fig. [ ] these later measures have reduced the spread of BSE.
However, they have not been one hundred per cent effective. As at 31st December 2003
there had been 81 cases of BSE in animals born since 1 August 1996 in the UK.
full text 91 pages;
http://www.mrc.ac.uk/pdf-about-tse_uk_strategy_june2005.pdf
GREETINGS AGAIN APHIS ET AL,
JUST what about those old studies at Mission Texas and the atypical TSE in cattle? would it not be prudent for human health purpose, the question that, with all the atypical TSEs showing up in animal and man in different countries, the fact that most all of these TSEs transmit as freely or not as freely as BSE (depending whom you have witnessed die from this agent either directly or indirectly via a multitude of potential routes and sources) to primates. would it not be prudent to ask yourself if some if not all of these sporadic CJDs might be a by-product of these TSEs either directly or indirectly via a multitude of proven routes and sources in animal studies? it is unethical for human transmission studies considering the fact that the agent is 100% fatal, slow, but fatal. there has been no sound science in any of the recent decisions in the USA in regards to BSE/TSE human or animal, all one has to do is look at TEXAS, the mad cow that got away, the stumbling and staggering one that NO TSE TEST AT ALL was done, ordered rendered, and then the infamous positive, positve, secret positive, inconclusive (NO WB), negative, 8 month delay, then the 'Fong Effect' took place, THEN FINALLY CONFIRMED SOME 8 MONTHS LATER IN WEYBRIDGE. Finally recently, another inconclusive that took place that sat untested on some shelf for about 4 months while the Texas mad cow blunder was going on. the tissues of this cow this time were preserved in preservative as to render any WB for further confirmation, what i called the 'FONG SYNDROME' or the 'end around' the WB ordered previously by the Honorable Phyllis Fong of the OIG. Politics at its finest, to hell with human health. WE find now that 9,200 USA POTENTIAL MAD COWS IN JUNE 2004 ENHANCED COVER-UP SURVEILLANCE PROGRAM WENT UNTESTED WITH NO RAPID TEST OR WB, ONLY IHC, the test that fails the most, that is very unreliable as noted above in my submission by Prusiner et al and other scientist.
NOW, back to Mission, Texas ;
Differences in tissue distribution could require new regulations regarding specific risk material (SRM) removal.
snip...end
full text 33 PAGES ;
http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
http://www.bseinquiry.gov.uk/files/yb/1988/10/00001001.pdf
It was, however, performed in the USA in 1979, when it was shown that cattle inoculated with the scrapie agent endemic in the flock of Suffolk sheep at the United States Department of Agriculture in Mission, Texas, developed a TSE quite unlike BSE. 32 The findings of the initial transmission, though not of the clinical or neurohistological examination, were communicated in October 1988 to Dr Watson, Director of the CVL, following a visit by Dr Wrathall, one of the project leaders in the Pathology Department of the CVL, to the United States Department of Agriculture. 33 The results were not published at this point, since the attempted transmission to mice from the experimental cow brain had been inconclusive. The results of the clinical and histological differences between scrapie-affected sheep and cattle were published in 1995. Similar studies in which cattle were inoculated intracerebrally with scrapie inocula derived from a number of scrapie-affected sheep of different breeds and from different States, were carried out at the US National Animal Disease Centre. 34 The results, published in 1994, showed that this source of scrapie agent, though pathogenic for cattle, did not produce the same clinical signs of brain lesions characteristic of BSE.
http://www.bseinquiry.gov.uk/
1: J Infect Dis. 1994 Apr;169(4):814-20.
Intracerebral transmission of scrapie to cattle.
Cutlip RC, Miller JM, Race RE, Jenny AL, Katz JB, Lehmkuhl HD, DeBey BM, Robinson MM.
USDA, Agriculture Research Service, National Animal Disease Center, Ames, IA 50010.
To determine if sheep scrapie agent(s) in the United States would induce a disease in cattle resembling bovine spongiform encephalopathy, 18 newborn calves were inoculated intracerebrally with a pooled suspension of brain from 9 sheep with scrapie. Half of the calves were euthanatized 1 year after inoculation. All calves kept longer than 1 year became severely lethargic and demonstrated clinical signs of motor neuron dysfunction that were manifest as progressive stiffness, posterior paresis, general weakness, and permanent recumbency. The incubation period was 14-18 months, and the clinical course was 1-5 months. The brain from each calf was examined for lesions and for protease-resistant prion protein. Lesions were subtle, but a disease-specific isoform of the prion protein was present in the brain of all calves. Neither signs nor lesions were characteristic of those for bovine spongiform encephalopathy.
MeSH Terms: Animals Brain/microbiology* Brain/pathology Cattle Cattle Diseases/etiology* Cattle Diseases/pathology Encephalopathy, Bovine Spongiform/etiology* Encephalopathy, Bovine Spongiform/pathology Immunoblotting/veterinary Immunohistochemistry Male Motor Neurons/physiology Prions/analysis Scrapie/pathology Scrapie/transmission* Sheep Sleep Stages Time Factors
Substances: Prions
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8133096&dopt=Citation
Intracerebral transmission of scrapie to cattle FULL TEXT PDF;
SNIP...
Discussion
WE conclude that American sources of sheep scrapie are transmissible to cattle by direct intracerebral inoculation but the disease induced is NOT identical to BSE as seen in the United Kingdom. While there were similarities in clinical signs between this experimental disease and BSE, there was no evidence of aggressiveness, hyperexcitability, hyperesthesia (tactile or auditory), or hyperemetria of limbs as has been reported for BSE (9). Neither were there extensive neurologic lesions, which are primary for BSE, such as severe vacuolation of neurons and neuropil or neuronal necrosis and gliosis. Although some vacuolation of neuropil, chromotolysis in neurons, and gliosis were seen in the brains of some affected calves, these were industinguishable from those of controls. Vacuolated neurons in the red nucleus of both challenged and normal calves were considered normal for the bovines as previously described (50).
PrP-res was found in ALL CHALLENGED CALVES REGARDLESS OF CLINCIAL SIGNS, and the amount of PrP-res positively related to the length of the incubation. ...
snip...
WE also conclude from these studies that scrapie in cattle MIGHT NOT BE RECOGNIZED BY ROUTINE HISTOPATHOLOGICAL EXAMINATION OF THE BRAIN AND SUGGEST THAT DETECTION OF PrP-res by immunohistochemistry or immunoblotting is necessary to make a definitive diagnosis. THUS, undiagnosed scrapie infection could contribute to the ''DOWNER-COW'' syndrome and could be responsible for some outbreaks of transmissible mink encephalopathy proposed by Burger and Hartsough (8) and Marsh and harsough (52). ...
snip...
Multiple sources of sheep affected with scrapie and two breeds of cattle from several sources were used inthe current study in an effort to avoid a single strain of either agent or host. Preliminary results from mouse inoculations indicate multiple strains of the agent were present in the pooled inoculum (unpublished data). ...
Transmission of the sheep scrapie to cattle was attempted in 1979 by using intracerebral, intramuscular, subcutaneous, and oral routes of inoculation of 5, 8- to 11-month old cattlw with a homologous mixture of brain from 1 affected sheep (61, 62). ONE of the 5 cattle develped neurologic signs 48 months after inoculation. Signs were disorientation, incoordination, a stiff-legged stilted gait, progressive difficulty in rising, and finally in terminal recumbency. The clinical course was 2.5 months. TWO of the 5 cattle similarly inoculated with brain tissue from a goat with scrapie exhibited similar signs 27 and 36 months after incoluation. Clinical courses were 43 an 44 days. Brain lesions of mild gliosis and vacuolation and mouse inoculation data were insufficient to confirm a diagnosis of scrapie. This work remained controversial until recent examination of the brains detected PrP-res in all 3 cattle with neurologic disease but in none of the unaffected cattle (62). Results of these studies are similar to ours and underscore the necessity of methods other than histopathology to diagnose scrapie infection in cattle. We believe that immunologic techniques for detecting PrP-res currently provide the most sensitive and reliable way to make a definitive diagnosis...
http://www.bseinquiry.gov.uk/files/sc/seac17/tab03.pdf
Visit to USA ... info on BSE and Scrapie
http://www.bseinquiry.gov.uk/files/yb/1988/10/00001001.pdf
GREETINGS AGAIN APHIS ET AL,
COMMENTING ON THE SRMs AND THE REMOVAL OF SRMs. I FIND IT DISTURBING THAT RECENTLY, AFTER A LONG BATTLE FOR DOCUMENTS VIA THE FOIA THAT THE MEDIA AND CONSUMERS UNION REQUESTED, THAT DURING THE JUNE 2004 ENHANCED BSE SURVIELLANCE PROGRAM, THAT OVER 1,000 CITATIONS WERE ISSUED FOR VARIOUS SRM VIOLATIONS, BUT YET IT TOOK THE FOIA TO GET THIS TO THE PUBLIC.
WOULD it not be likely that from some of these noncompliance reports that indeed some breaches led to some potential tainted materials to enter the animal/human feed chain?
ALL we have heard about in the last 7 years or better, well, since the 12/14/97 partial and voluntary ruminant-to-ruminant feed ban is that the feed ban is working, tripple fire walls, no ruminant protein entering the animal feed chain. along with this was a constant barage of 'no mad cow disease in the USA'. then we find this 12 year old TEXAS cow that was infected from tainted feed some time in that 12 year period. so, the NE TEXAS CJD cluster, where it was stated that NO mad cow was in the USA or TEXAS at that time frame, was in fact not true.
SINCE some 460 of these occurred because slaughter plants did not have an adequate plan for dealing with BSE in their plant's food safety plan, as required by the USDA, the analysis showed, and of those 460 violations, 60 percent described plans that contained no mention of BSE at all. then again, would it not be very possible that indeed some potentially tainted material of a BSE or atypical TSE DID enter the animal feed chain, thus later some of those animals entering the human food chain.
WHAT about the SRM violations? Violations of rules about the removal and handling of specified risk material (SRMs) occurred at 131 plants in at least 35 states. SRMs are the high-risk materials, such as brains and spinal cords, most likely to be infectious. More than 30 percent of the NRs analyzed were due to either improperly handling or removing SRMs. Could this not have also led to potentially BSE/TSE tainted materials entering the animal/human food chain?
In 10 percent of the NRs analyzed, plants incorrectly identified the age of cattle. THIS also could have led to tainted BSE/TSE SRM materials entering the animal/human food chain.
IN my opinion, this could have led to many feed discrepancies and should HAVE been reported to the public, without the media having to request this data via FOIA. I think in the future it would be best if the NRs (non-compliance reports) were made easily available to the public in there feed enforement reports. ...
FOR IMMEDIATE RELEASE AUGUST 18, 2005 5:25 PM CONTACT: Public Citizen (202) 588-1000
Evidence of Weak Meat Inspection Program Found in Nearly a Thousand Violations of Mad Cow Rules at Slaughter Plants Noncompliance Records Show Plants Failed to Follow Regulations
WASHINGTON - August 18 - In stark contrast to the public relations message touted by the U.S. Department of Agriculture (USDA) and the beef industry that the U.S. regulatory system is adequate to prevent the spread of mad cow disease, an analysis released today by the consumer group Public Citizen found significant lapses in the industry's compliance with federal rules. The analysis stems from a December 2004 Freedom of Information Act (FOIA) request from Public Citizen to the USDA for all "noncompliance records" (NRs) related to bovine spongiform encephalopathy (BSE). Public Citizen received copies of 829 records on Aug. 15.
More than half the violations (460) occurred because slaughter plants did not have an adequate plan for dealing with BSE in their plant's food safety plan, as required by the USDA, the analysis shows. Of those 460 violations, 60 percent described plans that contained no mention of BSE at all.
"The fact that 60 percent of the violations were due to a failure to even mention BSE or risk materials such as brains and spinal cords is significant," said Patty Lovera, deputy director of Public Citizen's food program. "If officials running a meat plant cannot be bothered to recognize the risk of BSE when writing their safety plan, how much of a priority is it in daily operations and training of staff?"
The analysis also found that:
Violations of rules about the removal and handling of specified risk material (SRMs) occurred at 131 plants in at least 35 states. SRMs are the high-risk materials, such as brains and spinal cords, most likely to be infectious. More than 30 percent of the NRs analyzed were due to either improperly handling or removing SRMs. The SRM ban is considered a critical firewall in protecting the food supply from BSE.
The violations described in the NRs occurred from January 2004 through March 2005. This shows that the problems in the plants persisted long after plants should have adapted to new rules issued in January 2004 after the discovery of the first case of BSE in the United States.
In 10 percent of the NRs analyzed, plants incorrectly identified the age of cattle. Properly determining the age of cattle is a crucial step in proper SRM removal because the definition of SRMs is dependent on age; in cattle older than 30 months, there is a greater likelihood that SRM will carry BSE and therefore must be removed. Accurately identifying the head, spine and carcass of cattle by age is necessary to ensure that all SRMs are removed as the carcass moves down the slaughter line. "These enforcement records only increase our concerns about how easily potentially infected cattle are bypassing inspection points at slaughterhouses, creating one more opportunity for infected meat to slip through the system," said Tony Corbo, legislative representative of Public Citizen's food program. "We're approaching the two-year mark of our first case of mad cow in the United States, yet the government is still lagging behind on protecting consumers."
Public Citizen sent the FOIA request to the USDA in December 2004 after the chairman of the USDA meat inspectors union, Stan Painter, raised concerns about the agency's policy for ensuring that cattle age is properly determined. Instead of investigating whether the policy was adequate, the agency opened a misconduct investigation on Painter. The investigation was closed this week, shortly after Public Citizen received the documentation, which contained more than 80 records of plants improperly identifying cattle age.
###
http://www.commondreams.org/news2005/0819-02.htm
Daily Update
On August 19, 2005, no inconclusive test results were reported.
National Veterinary Services Laboratory (NVSL) Immunohistochemistry (IHC) Testing Summary
The BSE enhanced surveillance program involves the use of a rapid screening test, followed by confirmatory testing for any samples that come back "inconclusive." The weekly summary below captures all rapid tests conducted as part of the enhanced surveillance effort. It should be noted that since the enhanced surveillance program began, USDA has also conducted approximately 9,200 routine IHC tests on samples that did not first undergo rapid testing. This was done to ensure that samples inappropriate for the rapid screen test were still tested, and also to monitor and improve upon IHC testing protocols. Of those 9,200 routine tests, one test returned a non-definitive result on July 27, 2005. That sample underwent additional testing at NVSL, as well as at the Veterinary Laboratories Agency in Weybridge, England, and results were negative. To view the IHC testing numbers from 1990 through 2004, click on the following link: http://www.aphis.usda.gov/lpa/issues/bse/surveillance/figure2f.html
GREETINGS AGAIN,
THE APHIS/USDA/FSIS et al has failed the public terribly with there industry friendly approach to erradicate BSE/TSE aka mad cow disease in the USA. the 8/4/97 partial and voluntary ruminant to rumiant feed ban program and there cealed borders were, have been and still are a joke. by sleeping with the industry, this administration has needlessly exposed millions and millions to the TSE agent at home, and abroad. THE fact that the first documented home grown mad cow came from TEXAS, the TAHC/USDA et al had already covered up one suspect mad cow and rendered with no test at all, but for the Honorable Phyllis Fong of the OIG to have the courage to go around the Agriculture Secretary Johann to have it confirmed in Weybridge, England (it would have never been confirmed any other way), but to have her do this, was truely a coup of sorts, one of the most couragous I have seen in a while by any person of our Government. BUT to finally have this mad cow confirmed, and then have the Secretary of Agriculture Johann not give praise to her for finally confirming this deadly disease in a home grown case, but to have him want her head for it raises serious serious doubts of the over June 2004 Enhanced BSE program where they claim some 500,000 cows have now been tested. NOW, we find indeed this was the case. WE find now that of those 500,000+ cows, 9,200 of them did not have rapid testing at all, no WB, only IHC. The least likely to find a case of BSE/TSE, the one that fails the most. a proven hit and miss test. Dr. Detwiler tried to tell them this in 2003 ;
USDA 2003
We have to be careful that we don't get so set in the way we do things that we forget to look for different emerging variations of disease. We've gotten away from collecting the whole brain in our systems. We're using the brain stem and we're looking in only one area. In Norway, they were doing a project and looking at cases of Scrapie, and they found this where they did not find lesions or PRP in the area of the obex. They found it in the cerebellum and the cerebrum. It's a good lesson for us. Ames had to go back and change the procedure for looking at Scrapie samples. In the USDA, we had routinely looked at all the sections of the brain, and then we got away from it. They've recently gone back. Dr. Keller: Tissues are routinely tested, based on which tissue provides an 'official' test result as recognized by APHIS .
Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't they still asking for the brain? But even on the slaughter, they're looking only at the brainstem. We may be missing certain things if we confine ourselves to one area.
snip.............
Dr. Detwiler: It seems a good idea, but I'm not aware of it. Another important thing to get across to the public is that the negatives do not guarantee absence of infectivity. The animal could be early in the disease and the incubation period. Even sample collection is so important. If you're not collecting the right area of the brain in sheep, or if collecting lymphoreticular tissue, and you don't get a good biopsy, you could miss the area with the PRP in it and come up with a negative test. There's a new, unusual form of Scrapie that's been detected in Norway. We have to be careful that we don't get so set in the way we do things that we forget to look for different emerging variations of disease. We've gotten away from collecting the whole brain in our systems. We're using the brain stem and we're looking in only one area. In Norway, they were doing a project and looking at cases of Scrapie, and they found this where they did not find lesions or PRP in the area of the obex. They found it in the cerebellum and the cerebrum. It's a good lesson for us. Ames had to go back and change the procedure for looking at Scrapie samples. In the USDA, we had routinely looked at all the sections of the brain, and then we got away from it. They've recently gone back.
Dr. Keller: Tissues are routinely tested, based on which tissue provides an 'official' test result as recognized by APHIS .
Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't they still asking for the brain? But even on the slaughter, they're looking only at the brainstem. We may be missing certain things if we confine ourselves to one area.
snip...
FULL TEXT;
Completely Edited Version PRION ROUNDTABLE
Accomplished this day, Wednesday, December 11, 2003, Denver, Colorado
Greetings again APHIS et al,
THE June 2004 Enhanced BSE/TSE surveillance program was a terrible failure, other than to prove just how bad the situation is in the USA, and how out of control the Federal Government is in trying to cover it up. THE OIG should hold an inquiry into this program. THE BSE MRR policy should be dismantled, and the USA BSE GBR risk assessment should be immediately raised to BSE GBR IV.
THE International guidelines for trade in animal and animal products which are developed by the World Organization for Animal Health (formerly known as the Office International des Epizooties (OIE)), is and has been terrible flawed. ALL one has to do is to look at the countries that have gone by there very minimal guidelines, most all went on to develop BSE. IT would be nice if the OIE et al would define "controlled BSE-risk country" or "effectively enforced ban". The USA and North America have neither. THIS has been proven time and time again via the GAO, OIG and the European EFSA BSE-risk assessments of North American countries. Many Countries have not even reported there first case of BSE yet, and many countries have not even produced a risk analysis for BSE. A fine example is Mexico and Canada. I pointed out about Canada above, but now lets look at Mexico, which is also a BSE GBR III country. IN Mexico, they are NOT even required to remove SRM;
Working Group Report on
the Assessment of the Geographical BSE-Risk (GBR) of
MEXICO
2004
Specified Risk Material (SRM) and fallen stock
There is no SRM-ban. SRM is normally destined for human consumption. According
to the CD, fallen stock from pasture and diseased animals are incinerated and not
rendered.
Conclusion on the ability to avoid recycling
In light of the above information, it has to be assumed that the BSE agent, should it
have entered Mexico, could have been recycled and potentially amplified.
snip...
In view of the above - described consideration the combination of the very / extremely
high external challenges with a very unstable system makes the occurrence of an
internal challenge likely in Mexico from approximately 1993 onwards.
4.2 Risk that BSE infectivity entered processing
It is likely that BSE infectivity entered processing at the time of imported 'at - risk'
MBM (1993) and at the time of slaughter of imported live 'at - risk' cattle (mid to late
1990's). The high level of external challenge is maintained throughout the reference
period, and the system has not been made stable, leading to increased internal
4.3 Risk that BSE infectivity was recycled and propagated
It is likely that BSE infectivity was recycled and propagated from approximately
1993. The risk has since grown consistently due to a maintained internal and external
challenge and lack of a stable system.
5. CONCLUSION ON THE GEOGRAPHICAL BSE - RISK
5.1 The current GBR as function of the past stability and challenge
The current geographical BSE risk (GBR) level is III, i.e. it is likely but not confirmed
that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent.
snip...end
http://www.efsa.eu.int/science/efsa_scientific_reports/gbr_assessments/scr_annexes/566/sr04_biohaz02_mexico_report_annex_en1.pdf
MORE ON THOSE USA BSE/TSE SEALED BORDERS
Aug. 22, 2005, 12:35AM
Mexican cattle business linked to drug cartels Animals sold to Texas ranchers by 2 companies can be seized By MICHAEL HEDGES Copyright 2005 Houston Chronicle Washington Bureau
WASHINGTON - The Treasury Department, trying to block an elaborate money-laundering scheme, has announced that two Mexican cattle companies are fronts for drug-trafficking cartels.
The action means that cattle sold by the companies to Texas ranchers after Friday's announcement are subject to seizure by the federal government, said a high-ranking Treasury official who asked not to be named.
"Cattle already purchased and owned before the companies were identified as tied to the drug cartels are not going to suddenly be blocked," the official said.
The Treasury Department plans to inform cattle associations and other groups later this week of the action taken against the Mexican companies, officials said. The Treasury also will provide other information, such as the brands used by the cattle companies linked to the drug cartels.
For now, buyers are expected to practice due diligence when purchasing cattle.
Two Mexican drug cartels were named in the Treasury Department's statement, the Arriola Marquez organization and the Arellano Felix cartel based in Tijuana. The Arriola Marquez group, based in Mexico's Chihuahua state, is linked to Mexican drug kingpin Joaquin "El Chapo" Guzman, the department said. Guzman leads one of the factions fighting for control of Nuevo Laredo and its smuggling routes into Texas, officials have said.
snip...
It is not clear how many Mexican cattle owned by companies linked to drug cartels had been sold in Texas, said government officials and Texas cattle raisers.
snip...end
http://www.chron.com/cs/CDA/ssistory.mpl/topstory/3319609
I do not think that USDA et al used rapid test, WB or IHC on any of these cattle for BSE/TSE.
TRIPLE firewalls and SEALED borders, I dont think so.
FINALLY COMMENTING ON THE UK BSE/nv/vCJD ONLY THEORY. there are different strains of TSE showing up in cattle, sheep, and goats. nvCJD has been documented in a 74 year old and the young are dying of sporadic CJD. one of the new atypical strains of TSE in cattle 'BASE' does not look like nvCJD in humans, but it looks very similar to sporadic CJD. also, Asante/Collinge et al have shown that BSE can propagate as nvCJD AND sporadic CJD. to continue to flounder and ignore all of this as in the past, to continue to cater to big beef, big feed will only allow this agent to further amplify and spread. there is more to this agent than the mad cow hamburger. AS long as the BSE MRR policy is in effect, the agent will continue to spread globally. references as follow ;
Characterization of two distinct prion strains derived from bovine spongiform encephalopathy transmissions to inbred mice Sarah E. Lloyd, Jacqueline M. Linehan, Melanie Desbruslais, Susan Joiner, Jennifer Buckell, Sebastian Brandner, Jonathan D. F. Wadsworth and John Collinge
MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, London WC1N 3BG, UK
Correspondence John Collinge j.collinge@prion.ucl.ac.uk
Distinct prion strains can be distinguished by differences in incubation period, neuropathology and biochemical properties of disease-associated prion protein (PrPSc) in inoculated mice. Reliable comparisons of mouse prion strain properties can only be achieved after passage in genetically identical mice, as host prion protein sequence and genetic background are known to modulate prion disease phenotypes. While multiple prion strains have been identified in sheep scrapie and Creutzfeldt-Jakob disease, bovine spongiform encephalopathy (BSE) is thought to be caused by a single prion strain. Primary passage of BSE prions to different lines of inbred mice resulted in the propagation of two distinct PrPSc types, suggesting that two prion strains may have been isolated. To investigate this further, these isolates were subpassaged in a single line of inbred mice (SJL) and it was confirmed that two distinct prion strains had been identified. MRC1 was characterized by a short incubation time (110±3 days), a mono-glycosylated-dominant PrPSc type and a generalized diffuse pattern of PrP-immunoreactive deposits, while MRC2 displayed a much longer incubation time (155±1 days), a di-glycosylated-dominant PrPSc type and a distinct pattern of PrP-immunoreactive deposits and neuronal loss. These data indicate a crucial involvement of the host genome in modulating prion strain selection and propagation in mice. It is possible that multiple disease phenotypes may also be possible in BSE prion infection in humans and other animals.
=======================
Identification of a second bovine amyloidotic spongiform encephalopathy: Molecular similarities with sporadic Creutzfeldt-Jakob disease
Cristina Casalone *, Gianluigi Zanusso , Pierluigi Acutis *, Sergio Ferrari , Lorenzo Capucci , Fabrizio Tagliavini , Salvatore Monaco , and Maria Caramelli *
*Centro di Referenza Nazionale per le Encefalopatie Animali, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna, 148, 10195 Turin, Italy; Department of Neurological and Visual Science, Section of Clinical Neurology, Policlinico G.B. Rossi, Piazzale L.A. Scuro, 10, 37134 Verona, Italy; Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna, Via Bianchi, 9, 25124 Brescia, Italy; and Istituto Nazionale Neurologico "Carlo Besta," Via Celoria 11, 20133 Milan, Italy
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved December 23, 2003 (received for review September 9, 2003)
Transmissible spongiform encephalopathies (TSEs), or prion diseases, are mammalian neurodegenerative disorders characterized by a posttranslational conversion and brain accumulation of an insoluble, protease-resistant isoform (PrPSc) of the host-encoded cellular prion protein (PrPC). Human and animal TSE agents exist as different phenotypes that can be biochemically differentiated on the basis of the molecular mass of the protease-resistant PrPSc fragments and the degree of glycosylation. Epidemiological, molecular, and transmission studies strongly suggest that the single strain of agent responsible for bovine spongiform encephalopathy (BSE) has infected humans, causing variant Creutzfeldt-Jakob disease. The unprecedented biological properties of the BSE agent, which circumvents the so-called "species barrier" between cattle and humans and adapts to different mammalian species, has raised considerable concern for human health. To date, it is unknown whether more than one strain might be responsible for cattle TSE or whether the BSE agent undergoes phenotypic variation after natural transmission. Here we provide evidence of a second cattle TSE. The disorder was pathologically characterized by the presence of PrP-immunopositive amyloid plaques, as opposed to the lack of amyloid deposition in typical BSE cases, and by a different pattern of regional distribution and topology of brain PrPSc accumulation. In addition, Western blot analysis showed a PrPSc type with predominance of the low molecular mass glycoform and a protease-resistant fragment of lower molecular mass than BSE-PrPSc. Strikingly, the molecular signature of this previously undescribed bovine PrPSc was similar to that encountered in a distinct subtype of sporadic Creutzfeldt-Jakob disease.
--------------------------------------------------------------------------------
C.C. and G.Z. contributed equally to this work.
To whom correspondence should be addressed.
E-mail: salvatore.monaco@mail.univr.it.
www.pnas.org/cgi/doi/10.1073/pnas.0305777101
=====================================
eurobiology Adaptation of the bovine spongiform encephalopathy agent to primates and comparison with Creutzfeldt- Jakob disease: Implications for human health Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*, Domíníque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James Ironside, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys*
* Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction des Sciences du Vivant/Département de Recherche Medicale, Centre de Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc, BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital, 75013 Paris, France; Creutzfeldt-Jakob Disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, United Kingdom
Edited by D. Carleton Gajdusek, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000 (received for review October 16, 2000)
Abstract Top Abstract Introduction Materials and Methods Results Discussion Conclusions References
There is substantial scientific evidence to support the notion that bovine spongiform encephalopathy (BSE) has contaminated human beings, causing variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns about the possibility of an iatrogenic secondary transmission to humans, because the biological properties of the primate-adapted BSE agent are unknown. We show that (i) BSE can be transmitted from primate to primate by intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD to humans could be readily recognized pathologically, whether it occurs by the central or peripheral route. Strain typing in mice demonstrates that the BSE agent adapts to macaques in the same way as it does to humans and confirms that the BSE agent is responsible for vCJD not only in the United Kingdom but also in France. The agent responsible for French iatrogenic growth hormone-linked CJD taken as a control is very different from vCJD but is similar to that found in one case of sporadic CJD and one sheep scrapie isolate. These data will be key in identifying the origin of human cases of prion disease, including accidental vCJD transmission, and could provide bases for vCJD risk assessment.
Introduction
============================
IN light of Asante/Collinge et al findings that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest _sporadic_ CJD;
-------- Original Message -------- Subject: re-BSE prions propagate as
either variant CJD-like or sporadic CJD Date: Thu, 28 Nov 2002 10:23:43
-0000 From: "Asante, Emmanuel A" To: "'flounder@wt.net'"
Dear Terry,
I have been asked by Professor Collinge to respond to your request. I am
a Senior Scientist in the MRC Prion Unit and the lead author on the
paper. I have attached a pdf copy of the paper for your attention. Thank
you for your interest in the paper.
In respect of your first question, the simple answer is, yes. As you
will find in the paper, we have managed to associate the alternate
phenotype to type 2 PrPSc, the commonest sporadic CJD.
It is too early to be able to claim any further sub-classification in
respect of Heidenhain variant CJD or Vicky Rimmer's version. It will
take further studies, which are on-going, to establish if there are
sub-types to our initial finding which we are now reporting. The main
point of the paper is that, as well as leading to the expected new
variant CJD phenotype, BSE transmission to the 129-methionine genotype
can lead to an alternate phenotype which is indistinguishable from type
2 PrPSc.
I hope reading the paper will enlighten you more on the subject. If I
can be of any further assistance please to not hesitate to ask. Best wishes.
Emmanuel Asante
<> ____________________________________
Dr. Emmanuel A Asante MRC Prion Unit & Neurogenetics Dept. Imperial
College School of Medicine (St. Mary's) Norfolk Place, LONDON W2 1PG
Tel: +44 (0)20 7594 3794 Fax: +44 (0)20 7706 3272 email:
e.asante@ic.ac.uk (until 9/12/02)
New e-mail: e.asante@prion.ucl.ac.uk (active from now)
____________________________________
snip...
full text ;
http://www.fda.gov/ohrms/dockets/ac/03/slides/3923s1_OPH.htm
SCRAPIE USA MONTHLY REPORT 2005
AS of March 31, 2005, there were 70 scrapie infected source flocks (Figure 3). There were 11 new infected and source flocks reported in March (Figure 4) with a total of 51 flocks reported for FY 2005 (Figure 5). The total infected and source flocks that have been released in FY 2005 are 39 (Figure 6), with 1 flock released in March. The ratio of infected and source flocks released to newly infected and source flocks for FY 2005 = 0.76 : 1. IN addition, as of March 31, 2005, 225 scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL), of which 53 were RSSS cases (Figure 7). This includes 57 newly confirmed cases in March 2005 (Figure 8). Fourteen cases of scrapie in goats have been reported since 1990 (Figure 9). The last goat cases was reported in January 2005. New infected flocks, source flocks, and flocks released or put on clean-up plans for FY 2005 are depicted in Figure 10. ...
FULL TEXT ;
http://www.aphis.usda.gov/vs/nahps/scrapie/monthly_report/monthly-report.html
SCRAPIE USA JUNE 2005 UPDATE
AS of June 30, 2005, there were 114 scrapie infected and source flocks (Figure 3). There were 14 new infected and source flocks reported in June (Figure 4) with a total of 123 flocks reported for FY 2005 (Figure 5).
snip...
In addition, as of June 30, 2005, 448 scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL), of which 106 were RSSS cases (Figure 7). This includes 81 newly confirmed cases in June 2005 (Figure 8). Fifteen cases of scrapie in goats have been reported since 1990 (Figure 9). The last goat case was reported in May 2005.
snip...end
http://www.aphis.usda.gov/vs/nahps/scrapie/monthly_report/monthly-report.html
USA CWD MAP
http://www.aphis.usda.gov/vs/nahps/cwd/labmap.html
Perspective
Chronic Wasting Disease and Potential Transmission to Humans Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,† Michael W. Miller,‡ Pierluigi Gambetti,§ and Lawrence B. Schonberger* *Centers for Disease Control and Prevention, Atlanta, Georgia, USA; †University of Wyoming, Laramie, Wyoming, USA; ‡Colorado Division of Wildlife, Fort Collins, Colorado, USA; and §Case Western Reserve University, Cleveland, Ohio, USA
Suggested citation for this article: Belay ED, Maddox RA, Williams ES, Miller MW, Gambetti P, Schonberger LB. Chronic wasting disease and potential transmission to humans. Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from: http://www.cdc.gov/ncidod/EID/vol10no6/03-1082.htm
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Chronic wasting disease (CWD) of deer and elk is endemic in a tri-corner area of Colorado, Wyoming, and Nebraska, and new foci of CWD have been detected in other parts of the United States. Although detection in some areas may be related to increased surveillance, introduction of CWD due to translocation or natural migration of animals may account for some new foci of infection. Increasing spread of CWD has raised concerns about the potential for increasing human exposure to the CWD agent. The foodborne transmission of bovine spongiform encephalopathy to humans indicates that the species barrier may not completely protect humans from animal prion diseases. Conversion of human prion protein by CWD-associated prions has been demonstrated in an in vitro cell-free experiment, but limited investigations have not identified strong evidence for CWD transmission to humans. More epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions.
SNIP...
Conclusions The lack of evidence of a link between CWD transmission and unusual cases of CJD, despite several epidemiologic investigations, and the absence of an increase in CJD incidence in Colorado and Wyoming suggest that the risk, if any, of transmission of CWD to humans is low. Although the in vitro studies indicating inefficient conversion of human prion protein by CWD-associated prions raise the possibility of low-level transmission of CWD to humans, no human cases of prion disease with strong evidence of a link with CWD have been identified. However, the transmission of BSE to humans and the resulting vCJD indicate that, provided sufficient exposure, the species barrier may not completely protect humans from animal prion diseases. Because CWD has occurred in a limited geographic area for decades, an adequate number of people may not have been exposed to the CWD agent to result in a clinically recognizable human disease. The level and frequency of human exposure to the CWD agent may increase with the spread of CWD in the United States. Because the number of studies seeking evidence for CWD transmission to humans is limited, more epidemiologic and laboratory studies should be conducted to monitor the possibility of such transmissions. Studies involving transgenic mice expressing human and cervid prion protein are in progress to further assess the potential for the CWD agent to cause human disease. Epidemiologic studies have also been initiated to identify human cases of prion disease among persons with an increased risk for exposure to potentially CWD-infected deer or elk meat (47). If such cases are identified, laboratory data showing similarities of the etiologic agent to that of the CWD agent would strengthen the conclusion for a causal link. Surveillance for human prion diseases, particularly in areas where CWD has been detected, remains important to effectively monitor the possible transmission of CWD to humans. Because of the long incubation period associated with prion diseases, convincing negative results from epidemiologic and experimental laboratory studies would likely require years of follow-up. In the meantime, to minimize the risk for exposure to the CWD agent, hunters should consult with their state wildlife agencies to identify areas where CWD occurs and continue to follow advice provided by public health and wildlife agencies. Hunters should avoid eating meat from deer and elk that look sick or test positive for CWD. They should wear gloves when field-dressing carcasses, bone-out the meat from the animal, and minimize handling of brain and spinal cord tissues. As a precaution, hunters should avoid eating deer and elk tissues known to harbor the CWD agent (e.g., brain, spinal cord, eyes, spleen, tonsils, lymph nodes) from areas where CWD has been identified.
http://www.cdc.gov/ncidod/EID/vol10no6/03-1082.htm
Research
Environmental Sources of Prion Transmission in Mule Deer Michael W. Miller,* Elizabeth S. Williams,† N. Thompson Hobbs,‡ and Lisa L. Wolfe* *Colorado Division of Wildlife, Fort Collins, Colorado, USA; †University of Wyoming, Laramie, Wyoming, USA; and ‡Colorado State University, Fort Collins, Colorado, USA
Suggested citation for this article: Miller MW, Williams ES, Hobbs NT, Wolfe LL. Environmental sources of prion transmission in mule deer. Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from: http://www.cdc.gov/ncidod/EID/vol10no6/04-0010.htm
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Whether transmission of the chronic wasting disease (CWD) prion among cervids requires direct interaction with infected animals has been unclear. We report that CWD can be transmitted to susceptible animals indirectly, from environments contaminated by excreta or decomposed carcasses. Under experimental conditions, mule deer (Odocoileus hemionus) became infected in two of three paddocks containing naturally infected deer, in two of three paddocks where infected deer carcasses had decomposed in situ ˜1.8 years earlier, and in one of three paddocks where infected deer had last resided 2.2 years earlier. Indirect transmission and environmental persistence of infectious prions will complicate efforts to control CWD and perhaps other animal prion diseases.
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Discussion
Prions cannot be directly demonstrated in excreta or soil. However, CWD infection-specific protease-resistant prion protein (PrPCWD) accumulates in gut-associated lymphoid tissues (e.g., tonsils, Peyer patches, and mesenteric lymph nodes) of infected mule deer (11,17,22), which implicates alimentary shedding of the CWD agent in both feces and saliva (10,11,17). Because PrPCWD becomes progressively abundant in nervous system and lymphoid tissues through the disease course (11), carcasses of deer succumbing to CWD also likely harbor considerable infectivity and thus serve as foci of infection. We could not determine the precise mechanism for CWD transmission in excreta-contaminated paddocks, but foraging and soil consumption seemed most plausible. Deer did not actively consume decomposed carcass remains, but they did forage in the immediate vicinity of carcass sites where a likely nutrient flush (23) produced lush vegetation (Figure).
Our findings show that environmental sources of infectivity may contribute to CWD epidemics and illustrate the potential complexity of such epidemics in natural populations. The relative importance of different routes of infection from the environment cannot be discerned from our experiment, but each could play a role in sustaining natural epidemics. Although confinement likely exaggerated transmission probabilities, conditions simulated by this experiment do arise in the wild. Mule deer live in established home ranges and show strong fidelity to historic home ranges (24-26). As a result of such behavior, encounters with contaminated environments will occur more frequently than if deer movements were random. Feces and carcass remains are routinely encountered on native ranges, thus representing natural opportunities for exposure. Social behavior of deer, particularly their tendency to concentrate and become sedentary on their winter range, also may increase the probability of coming into contact with sources of infection in their environment.
The ability of the CWD agent to persist in contaminated environments for >2 years may further increase the probability of transmission and protract epidemic dynamics (8). Because infectivity in contaminated paddocks could not be measured, neither the initial levels nor degradation rate of the CWD agent in the environment was estimable. However, the observed persistence of the CWD agent was comparable to that of the scrapie agent, which persisted in paddocks for ˜1 to 3 years after removal of naturally infected sheep (7). Similarities between the CWD and scrapie agents suggest that environmental persistence may be a common trait of prions. Whether persistence of the BSE prion in contaminated feed production facilities or in environments where cattle reside contributed to BSE cases in the United Kingdom after feed bans were enacted (27) remains uncertain but merits further consideration.
Indirect transmission and environmental persistence of prions will complicate efforts to control CWD and perhaps other animal prion diseases. Historically, control strategies for animal prion diseases have focused on infected live animals as the primary source of infection. Although live deer and elk represent the most plausible mechanism for geographic spread of CWD, our data show that environmental sources could contribute to maintaining and prolonging local epidemics, even when all infected animals are eliminated. Moreover, the efficacy of various culling strategies as control measures depends in part on the rates at which the CWD agent is added to and lost from the environment. Consequently, these dynamics and their implications for disease management need to be more completely understood.
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http://www.cdc.gov/ncidod/EID/vol10no6/04-0010.htm
For Release: Wednesday, May 4, 2005 Contact: Michael Fraser (518) 402-8000 DEC Announces Sampling Results for Chronic Wasting Disease The New York State Department of Environmental Conservation today announced that it has received the remainder of test results for chronic wasting disease (CWD) that were part of intensive sampling efforts in central New York. DEC has received two positive results for the disease out of 292 wild deer sampled.
The first positive result in a wild deer was announced on April 27, 2005 and came from a yearling white-tailed deer sampled from the Town of Verona, Oneida County. The second positive result is from a 3-year-old doe, located within a mile of the location where the initial positive result was detected. The sample tissues were tested at the State's Veterinary Diagnostic Laboratory at Cornell University. These are the first known occurrences of CWD in wild deer in New York State.
DEC implemented intensive monitoring efforts after CWD was found in two captive white-tailed deer herds in Oneida County - the first incidents of CWD in New York State. On April 8, 2005, the State Department of Agriculture and Markets (DAM) completed testing of the captive deer and found a total of five positive results for CWD in the two captive herds.
DEC, along with the U.S. Department of Agriculture's Wildlife Services program, completed intensive monitoring on April 30, 2005. The effort resulted in 290 samples of wild deer from Oneida County, two from neighboring Madison County, and 25 wild deer from the Town of Arietta, Hamilton County. Since 2002, DEC has conducted statewide sampling of wild deer for CWD. When combined with sampling efforts in Oneida and Hamilton Counties, DEC has collected more than 3,700 samples from wild white-tailed deer.
DEC and DAM will continue public outreach to interested parties in central New York to help educate citizens on CWD and to discuss next steps to be taken. The agencies will hold a public meeting on Thursday, May 12, 2005, at 7 p.m. in the Vernon-Verona-Sherrill High School Auditorium, located on State Highway 31 in the Town of Verona. In addition, DEC and DAM will conduct additional outreach and continue to aggressively pursue inspection and enforcement across the State.
DAM continues to investigate, sample and test white-tailed deer from two captive herds directly associated with the two herds that were confirmed positive for CWD in Oneida County. Results for these sampling efforts will be announced when available.
Statewide sampling for CWD - which has resulted in more than 1,000 tests each year - will be increased to closely monitor the distribution and prevalence of CWD in wild deer. In addition, DEC has implemented emergency regulations regarding the handling, transport and management of deer in the State. The emergency regulations are currently in effect and represent an aggressive response to the recent discovery of chronic wasting disease (CWD) in Oneida County.
DEC's emergency regulations are designed to ensure the proper handling of deer and prevent further spread of CWD in the wild herd. The emergency regulations are effective for 90 days. In addition, DEC will begin the process of developing permanent regulations, which will appear in the State Register and include a 45-day public comment period.
CWD is a transmissible disease that affects the brain and central nervous system of certain deer and elk. There is no evidence that CWD is linked to disease in humans or domestic livestock other than deer and elk. More information on CWD can be found at DEC's website at www.dec.state.ny.us/website/dfwmr/wildlife/deer/currentcwd.html
05-48
http://www.dec.state.ny.us/website/press/pressrel/2005/200548.html
WE MUST ADHERE TO THE BSE GBR RISK ASSESSMENTS, WE MUST WORK TO ENHANCE THOSE BSE GBR RISK ASSESSMENTS TO INCLUDE ALL ANIMAL TSEs, USDA/APHIS/GW ET ALs BSE MRR (Minimal Risk Region) should be REPEALED/DISBANDED/TRASHED/NADA and done away with for good. The BSE MRR policy is nothing more than a legal tool to trade all strains of TSEs globally...
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518
http://www.regulations.gov/fdmspublic/ContentViewer?objectId=0900006480086ebc&disposition=attachment&contentType=msw6
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