|
||||||||||||||||||
 |
From: TSS ()
Research Continues Worldwide on Rare BSE Strain (10/18/06 07:35) OMAHA (DTN) -- Scientists know how to detect atypical BSE, but admit they have limited knowledge about the rare strain of bovine spongiform encephalopathy that has been found in the two U.S.-born cases of the disease. A USDA scientist who conducts research on atypical BSE also declined to answer whether USDA's new testing regime would continue to find cattle infected with the atypical strain. First discovered in France and Italy, atypical BSE has become a growing topic at scientific meetings on transmissible spongiform encephalopathies. Several research papers on the issue were presented last month at a meeting in Italy. The struggle is interpreting what atypical BSE can mean, particularly given the rarity of the disease globally. "To be honest with you, we really don't know," said Linda Detwiler, a former USDA scientist now at the Virginia-Maryland College of Veterinary Medicine. "There's so little (data) and it's really an emerging issue right now." Scientists have found at least two strains of BSE that do not appear to show the same patterns or staining on tests as "classic BSE." DTN first reported last May that two of the cases in the United States -- one in Texas and one in Alabama -- were atypical. A cow earlier this year in Manitoba also was an atypical case. The two strains have been broken down into high-molecular and low-molecular strains. The high-molecular strain, which was found in the two U.S. cases, has occurred in older animals ranging from 10 to 16 years of age. When transmitting the disease to mice, the mice take longer incubation periods to show clinical signs of the disease than mice infected with classical BSE. Outside of the U.S. and Canada, the high-molecular strain has been found in six other countries. Richt said he was confident the tests used in the U.S. can detect the diseases, even though the high-molecular BSE shows up as a weaker result on one testing protocol. In 2005, the U.S. added a second test to detect BSE cases after U.S. officials initially called the Texas case negative for BSE. http://www.hpj.com/dtnnewstable.cfm?type=story&sid=17794 Research Project: Study of Atypical Bse Location: Virus and Prion Diseases of Livestock Project Number: 3625-32000-073-07 Approach: http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490 Subject: PrPSc distribution of a natural case of bovine spongiform encephalopathy Date: August 8, 2005 at 12:28 pm PST 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 controversies 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 9/13/2005 179 Page 10 of 17 BSE cattle may need to be reexamined. 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 snip... "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. 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 ================================= [Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and Requirements for the Disposition of Non-Ambulatory Disabled Cattle http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf THE SEVEN SCIENTIST REPORT *** http://www.fsis.usda.gov/OPPDE/Comments/2006-0011/2006-0011-1.pdf SEE STEADY INCREASE IN SPORADIC CJD IN THE USA FROM p.s. please note the 47 PENDING CASES to Sept. 2005 p.s. please note the 2005 Prion D. total 120(8) p.s. please note sporadic CJD 2002(1) 1=3 TYPE UNKNOWN??? p.s. please note 2004 prion disease (6) 6=7 TYPE snip... Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
|
