Sessions

Joseph Y. Abrams 박사팀이 발표한 논문의 요약문은 아래와 같습니다.

Abstract 

The transmission of bovine spongiform encephalopathy (BSE) to human beings and the spread of chronic wasting disease (CWD) among cervids have prompted concerns about zoonotic transmission of prion diseases. Travel to the United Kingdom and other European countries, hunting for deer or elk, and venison consumption could result in the exposure of US residents to the agents that cause BSE and CWD. The Foodborne Diseases Active Surveillance Network 2006-2007 population survey was used to assess the prevalence of these behaviors among residents of 10 catchment areas across the United States. Of 17,372 survey respondents, 19.4% reported travel to the United Kingdom since 1980, and 29.5% reported travel to any of the nine European countries considered to be BSE-endemic since 1980. The proportion of respondents who had ever hunted deer or elk was 18.5%, and 1.2% had hunted deer or elk in a CWD–endemic area. More than two thirds (67.4%) reported having ever eaten deer or elk meat. Respondents who traveled spent more time in the United Kingdom (median 14 days) than in any other BSE-endemic country. Of the 11,635 respondents who had consumed venison, 59.8% ate venison at most one to two times during their year of highest consumption, and 88.6% had obtained all of their meat from the wild. The survey results were useful in determining the prevalence and frequency of behaviors that could be important factors for foodborne prion transmission.

일본 후쿠오카의 한 농장에서 지난 3월 30일 사망한 양이 스크래피에 감염되어 있는 사실을 확인했다는 뉴스입니다.

스크래피는 전염성 프리온에 의해 양의 뇌가 스펀지처럼 구멍이 숭숭 뚫리는 해면상뇌증으로 광우병과 증상이 비슷합니다만 인간에게 전염이 되지 않습니다.

일본에서 스크래피가 확인된 것은 지난 2005년 이후 처음있는 일이라고 합니다. 일본 정부당국은 양과 염소의 수출선적을 중단할 계획이 없다고 합니다.

Sheep with scrapie found in Japan

출처 : April 14, 2011
http://www.physorg.com/news/2011-04-sheep-scrapie-japan.html

A dead sheep infected with scrapie — a degenerative disease of the nervous system similar to mad cow disease — has been found in western Japan, an official said on Thursday.

The animal died on March 31 on a farm in Fukuoka prefecture where around 50 sheep and goats were kept, said prefectural official Shigetaka Yamashita, adding tests had identified the cause of death as scrapie.

It was the first case of the disease in Japan since 2005 when it was detected in a flock in Kanagawa, south of Tokyo, Yamashita said.

“The sheep will be incinerated soon and we will check the remaining sheep and goats at the farm,” he said, adding that the prefecture had no plan to impose any ban on shipments of sheep or goats.

Sheep farming is not common in Japan and is mainly concentrated on the far northern island of Hokkaido.

Scrapie is related to bovine spongiform encephalopathy (BSE), or mad cow disease, a highly infectious condition that has devastated whole herds of cows in Japan and other parts of the world, and which has been linked to Creutzfeldt-Jakob disease in humans.

캐나다 식품검사청(CFIA)에서 지난 2월 18일 알버타 주의 젖소가 광우병(BSE)에 감염된
사실을 확인했다고 밝혔다는 로이터 통신의 뉴스입니다.

캐나다의 18번째 광우병 소는 77개월령의 젖소(77-month-old dairy cow)라고 합니다.

캐나다산 쇠고기는 지난 2003년 캐나다에서 광우병이  발행한 이후 국내에 수입이 금지되고
있습니다만, 캐나다는 미국과 같은 해에 OIE로부터 광우병 통제국가 등급을 받았습니다.

특히 지난 2008년 촛불시위의 발단이 되었던 미국산 쇠고기의 전면 수입개방에 따라
캐나다 정부는 자국산 쇠고기과 미국산 쇠고기를 차별 대우하는 한국 정부를 WTO에
제소한 상황입니다.

현재 국내에서 구제역과 조류독감 발생으로 캐나다와의 쇠고기 수입협상이 약간 지연되고
있는 상황인데, 이번 18번째 광우병 발생이 한-캐나다 쇠고기 협상에 영향을 끼칠 수 밖에
없다고 생각합니다.

Alberta dairy cow found with mad cow disease

출처 : 로이터통신 – Fri Mar 4, 10:08 am ET

WINNIPEG, Manitoba (Reuters) – Canadian government officials have found a dairy cow in Alberta with mad cow disease, but the finding is not surprising and shouldn’t affect beef exports, a spokesman for the CFIA said on Friday.

The agency confirmed the case of bovine spongiform encephalopathy, or BSE as the disease is also known, on February 18 in a 77-month-old dairy cow, spokesman Guy Gravelle said.

In 2003, the first discovery of a cow in Canada with the disease led to closures of numerous export markets to Canadian beef. Most have reopened, other than South Korea and China, and importers are no longer as sensitive to new cases as countries such as Canada now have monitoring systems in place.

Canada continues to be rated a “controlled risk” for the disease by the World Organization for Animal Health, Gravelle said. The newest case may delay any upgrade to Canada’s international risk status as a country cannot apply for negligible status sooner than 11 years after the latest-born case.

The cow has been destroyed and no part of its carcass entered the human food or animal feed systems, Gravelle said.

The case, which is believed to be Canada’s 18th, should not affect exports of Canadian cattle or beef, he said, as a small number of BSE cases are expe-cted as Canada monitors for the disease.

(Reporting by Rod Nickel; Editing by Walter Bagley)

네덜란드가 광우병 위험이 종식되었다는 조건에서 가축사료에 동물성 단백질을 사용할 수 있도록 EU에 요구하고 있는 폴란드를 지지한다는 뉴스입니다.

다만 네덜란드는 동종식육은 반대하는데… 다시 말해 닭을 원료로 한 육골분 사료를 닭에게 먹인다든지, 돼지를 원료로 한 육골분 사료를 돼지에게 먹인다든지, 반추동물(소, 염소 등)을 원료로 한 육골분 사료를 소에게 먹이는 것을 반대한다고 밝혔습니다.

The Netherlands backs animal protein in feed plan

출처 : DutchNews Monday 21 February 2011
http://www.dutchnews.nl/news/archives/2011/02/the_netherlands_backs_animal_p.php

The Netherlands backs Poland in its call for the European Union to allow animal products to be used again in animal feed, as long as the risk of mad cow disease has been eradicated, the Volkskrant reports on Monday.

Animal protein has been banned from animal feed since the 1990s following the BSE scandal.

Poland, which takes over the revolving EU chairmanship in the second half of this year, wants to use pig and chicken waste in feed because it is much cheaper than soya.

The paper says the Netherlands backs the proposal on condition chicken meal is not fed to chickens or pig meal to pigs. It also opposes the use of protein from ruminants, such as cows and goats.

Last year there were three cases of mad cow disease in the Netherlands.

특히 이 연구에서는 2007년까지 알려진 것보다 8개월이나 빠른 시기인 접종 후 24개월(28개월령으로 추정) 후에 중추신경, 말초신경, 회장에서 광우병 원인체인 변형 프리온이 검출되었다고 보고하고 있습니다.

=======================================
J Gen Virol. 2007 Mar;88(Pt 3):1048-55.

Prions spread via the autonomic nervous system from the gut to the central nervous system in cattle incubating bovine spongiform encephalopathy.

Hoffmann C, Ziegler U, Buschmann A, Weber A,

Kupfer L, Oelschlegel A, Hammerschmidt B, Groschup MH.

http://vir.sgmjournals.org/cgi/content/full/88/3/1048?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1&FIRSTINDEX=0&volume=88&issue=3&resourcetype=HWCIT

Abstract

To elucidate the still-unknown pathogenesis of bovine spongiform encephalopathy (BSE), an oral BSE challenge and sequential kill study was carried out on 56 calves. Relevant tissues belonging to the peripheral and central nervous system, as well as to the lymphoreticular tract, from necropsied animals were analysed by highly sensitive immunohistochemistry and immunoblotting techniques to reveal the presence of BSE-associated pathological prion protein (PrPSc) depositions. Our results demonstrate two routes involving the autonomic nervous system through which BSE prions spread by anterograde pathways from the gastrointestinal tract (GIT) to the central nervous system (CNS): (i) via the coeliac and mesenteric ganglion complex, splanchnic nerves and the lumbal/caudal thoracic spinal cord (representing the sympathetic GIT innervation); and (ii) via the Nervus vagus (parasympathetic GIT innervation). The dorsal root ganglia seem to be subsequently affected, so it is likely that BSE prion invasion of the non-autonomic peripheral nervous system (e.g. sciatic nerve) is a secondary retrograde event following prion replication in the CNS. Moreover, BSE-associated PrPSc was already detected in the brainstem of an animal 24 months post-infection, which is 8 months earlier than reported previously. These findings are important for the understanding of BSE pathogenesis and for the development of new diagnostic strategies for this infectious disease.

광우병, 인간광우병,스크래피 등 전염성 해면상뇌증(TSE)의 원인물질인 병원성 프리온 단백질이
중추신경계로 퍼지기 전에 림프조직에서 복제가 일어나는데… 내장의 수지상 세포를 통해 
장으로부터 프리온 단백질이 이동하는 기전을 규명한 논문입니다. 

경구 섭취된 프리온 단백질은 장벽의 파이어스 패치(peyers patch)를 통해 흡수되어 림프계로 전달되고, 림프계 내부에서는 면역세포들의 내포작용(endocytosis)을 통한 탐식작용으로 림프절, 비장, 편도선 등으로 세포 이동이 일어나며, 비장에서 케모킨 수용체(chemokine receptor)인 CXCR5가 결핍된 경우 소포성 수지상 세포가 비장과 연결과 연결된 신경에 접근하게 되며, 접근 위치에 도착하고 나면 수지상 세포의 도움을 받아 프리온 단백질이 척수(spinal cord)의 신경축으로 이동하여 뇌에 도달하게 됩니다.

Migrating intestinal dendritic cells transport PrP(Sc) from the gut.

Huang FP, Farquhar CF, Mabbott NA, Bruce ME,

MacPherson GG.

Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK.

출처 : J Gen Virol. 2002 Jan;83(Pt 1):267-71.
http://www.ncbi.nlm.nih.gov/pubmed/11752724

Abstract

Bovine spongiform encephalopathy, variant Creutzfeldt-Jakob disease (vCJD) and possibly also sheep scrapie are orally acquired transmissible spongiform encephalopathies (TSEs). TSE agents usually replicate in lymphoid tissues before they spread into the central nervous system. In mouse TSE models PrP(c)-expressing follicular dendritic cells (FDCs) resident in lymphoid germinal centres are essential for replication, and in their absence neuroinvasion is impaired. Disease-associated forms of PrP (PrP(Sc)), a biochemical marker for TSE infection, also accumulate on FDCs in the lymphoid tissues of patients with vCJD and sheep with natural scrapie. TSE transport mechanisms between gut lumen and germinal centres are unknown. Migratory bone marrow-derived dendritic cells (DCs), entering the intestinal wall from blood, sample antigens from the gut lumen and carry them to mesenteric lymph nodes. Here we show that DCs acquire PrP(Sc) in vitro, and transport intestinally administered PrP(Sc) directly into lymphoid tissues in vivo. These studies suggest that DCs are a cellular bridge between the gut lumen and the lymphoid TSE replicative machinery.