건강과 대안 » 스크래피

[광우병] 일본 후쿠오카에서 스크래피 감염 사망 양 발견

건강과대안 — Fri, 15 Apr 2011 15:19:04 +0000

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.

[광우병] 캐나다에서 암, 광우병 모두 예방할 수 있는 항체 발견 주장

건강과대안 — Fri, 06 Aug 2010 16:31:21 +0000

캐나다의 브리티쉬 콜럼비아(BC) 대학교의 연구진들이 인간의 암과 동물의 소모성 뇌질환(광우병, 스크래피, 사슴의 만성소모성질환 등) 등의 진행을 중단시킬 수 있는 백신을 개발할 수 있는 길을 열어줄 수 있는 놀라운 연구결과를 발표했다는 소식입니다.

연구팀은 epitopes이라 불리는 항원(抗原) 결정기(決定基)에 작용하는 특정한 항체들을 분리해냈다고 합니다.

그런데 더욱 놀라운 것은 이 항체들이 특정 암세포에 반응을 했다고 합니다.

연구진의 희망은 이 항체들을 이용하여 암과 광우병을 동시에 예방할 수 있는 백신을 개발하는 것이라고 합니다.

물론 광우병과 관련하여 치료제나 예방약 개발했다는 주장이 과학적 사실임이 입증된 적은
한 번도 없습니다만… 이번 연구결과가 획기적 연구결과일지, 아니면 1회성 해프닝일지는
앞으로 과학계의 검증을 지켜보아야 할 것 같습니다.

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Unique link found between mad cow disease and cancer

Angela Mulholland, CTV.ca News Staff

Date: Monday Aug. 2, 2010 4:05 PM ET
http://www.ctv.ca/CTVNews/Health/20100730/prion-seiases-cancer-vaccine-100802/

Researchers led by University of British Columbia researcher Neil Cashman say they’ve made a surprise find about human cancer and brain-wasting diseases in animals that could pave the way for vaccines to halt all the diseases.

Cashman, a neurologist and researcher, was working on therapies for preventing transmissible spongiform encephalopathies, a group of animal brain-wasting diseases that include BSE in cows, scrapie in sheep, and chronic wasting disease in deer and other cervids.

Though the illnesses each affect different animals they are all caused by prions, which are unique infectious agents that cause the normal prion protein to go “rogue.”

Cashman explains that a protein is a chain of amino acids that only acquires its function by being folded properly. When a prion protein becomes misfolded after contact with another misfolded prion protein, it exposes certain regions in the normal prion protein, technically called “epitopes”.

His team had identified a group of antibodies they thought could target these epitopes, and thus halt the disease. But in order to test the antibodies, using a technique called “immunostaining,” they needed a line of easy-to-grow, regular cells to act as “negative controls.”

“And lo and behold, we found a few that stained intensely with these antibodies,” Cashman explained to CTV.ca.

Quite to Cashman’s surprise, some of the cancer cell lines reacted to the same antibody he was testing on prion-infected brain cells.

“We realized that if these [cancer] tumour cells stain for these antibodies, [the epitopes] could be a target for cancer immunotherapies,” Cashman said.

“We spent months trying to disprove the findings, thinking perhaps it was some kind of mistake. And eventually, we proved to our satisfaction that this antibody staining was real.”

He says teams at UBC and B.C. Cancer Research Centre are now testing how these antibodies can be used to develop a vaccine to treat cancer in mice.

If all goes well, it’s possible a vaccine could one day be tested on human cancers too, though Cashman cautions these are still “very early days.”

One aspect that makes dreams of a vaccine against cancer exciting is that the therapy would target only “misfolded” prion proteins, while sparing normal prion proteins. So unlike chemotherapies that kill off healthy cells along with cancer, therapies that target misfolded prion protein would attack only rogue cells, sparing the healthy ones.

Cashman said it’s possible that the same immunotherapy could also work in human prion diseases, such as “mad cow disease” and classical Creutzfeldt-Jakob Disease – but only if there were a way to identify infections in their earliest stages, before the illness caused symptoms.

“CJD is a very rapidly progressive disease, so by the time you make a definitive diagnosis, usually the patient has only a few weeks to live,” Cashman explained.

“Perhaps if we had a good diagnostic for the incubating phase [of CJD], then yes, it’s possible that a vaccine against these epitopes could block the infection before it gets to the brain. But that’s theoretical,” he said.

This new area of research is being funded under PrioNet Canada’s Bootstrap program and with the assistance of two industry partners: Amorfix Life Sciences Ltd.; and Saskatoon-based PREVENT – the Pan Provincial Vaccine Initiative.

Cashman is the scientific founder and board member of Amorfix, and is the scientific director of PrioNet Canada.

[광우병] 그리스연구팀, “물고기도 광우병 걸릴 수 있다” 발표

건강과대안 — Mon, 28 Sep 2009 19:04:39 +0000

그리스 과학자들이 물고기도 광우병에 걸릴 수 있다는 연구결과를 최근 PLoS ONE 4(7)에 발표하였습니다.

Evgenia Salta박사팀은 그리스의 대표적인 양식 물고기인 치푸라(gilthead sea bream=Sparus aurata)에게 BSE 및 스크래피를 경구로 감염시킨 결과, 24개월 후에 물고기의 뇌에 비정형 프리온 단백질이 침착된 것을 항체검사를 통해 확인하였습니다.(정상 프리온 단백질을 프로테인키나제라는 효소로 처리한 후 항체검사를 통해 비정형 프리온 단백질을 검출했습니다.)

그런데 이 물고기들은 신경퇴행 등의 임상증상을 보이지는 않았다고 합니다.

그리고 스크래피에 감염된 양의 뇌를 경구로 투여한 물고기보다 BSE에 감염된 소의 뇌를 경구로 투여한 물고기에서 더 빨리 그리고 더 광범위하게 비정형 프리온이 축적되었다고 합니다.

양식 물고기 같은 경우는 많은 대중들의 식단에 올라가는 식재료이기 때문에 물고기의 광우병에 대한 추가 연구가 필요할 뿐만 아니라, 물고기를 통한 인간광우병 전염 가능성에 대한 경각심을 가져야 할 것입니다.

Evgenia Salta박사팀의 연구결과에 대한 요약문은 아래에 있으며, 전문은 첨부파일을 보시면 됩니다.

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Evaluation of the Possible Transmission of BSE and Scrapie to Gilthead Sea Bream (Sparus aurata)

출처 : PLoS ONE 4(7): e6175. doi:10.1371/journal.pone.0006175
Received: March 27, 2009; Accepted: May 19, 2009; Published: July 28, 2009
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0006175

Evgenia Salta¹^#, Cynthia Panagiotidis²^#, Konstantinos Teliousis³, Spyros Petrakis¹^,⁴, Eleftherios Eleftheriadis⁵, Fotis Arapoglou⁵, Nikolaos Grigoriadis⁶, Anna Nicolaou⁷, Eleni Kaldrymidou³, Grigorios Krey⁵, Theodoros Sklaviadis²^*

1 Department of Pharmacology, Aristotle University of Thessaloniki, Thessaloniki, Greece, 2 Centre for Research and Technology-Hellas, Institute of Agrobiotechnology, Thessaloniki, Greece, 3 Laboratory of Pathology, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece, 4 Max Delbruck Center for Molecular Medicine, Department of Neuroproteomics, Berlin-Buch, Germany, 5 National Agricultural Research Foundation, Fisheries Research Institute, Nea Peramos, Greece, 6 B’ Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece, 7 Department of Business Administration, University of Macedonia, Thessaloniki, Greece

Abstract

In transmissible spongiform encephalopathies (TSEs), a group of fatal neurodegenerative disorders affecting many species, the key event in disease pathogenesis is the accumulation of an abnormal conformational isoform (PrP^Sc) of the host-encoded cellular prion protein (PrP^C). While the precise mechanism of the PrP^C to PrP^Sc conversion is not understood, it is clear that host PrP^C expression is a prerequisite for effective infectious prion propagation. Although there have been many studies on TSEs in mammalian species, little is known about TSE pathogenesis in fish. Here we show that while gilthead sea bream (Sparus aurata) orally challenged with brain homogenates prepared either from a BSE infected cow or from scrapie infected sheep developed no clinical prion disease, the brains of TSE-fed fish sampled two years after challenge did show signs of neurodegeneration and accumulation of deposits that reacted positively with antibodies raised against sea bream PrP. The control groups, fed with brains from uninfected animals, showed no such signs. Remarkably, the deposits developed much more rapidly and extensively in fish inoculated with BSE-infected material than in the ones challenged with the scrapie-infected brain homogenate, with numerous deposits being proteinase K-resistant. These plaque-like aggregates exhibited congophilia and birefringence in polarized light, consistent with an amyloid-like component. The neurodegeneration and abnormal deposition in the brains of fish challenged with prion, especially BSE, raises concerns about the potential risk to public health. As fish aquaculture is an economically important industry providing high protein nutrition for humans and other mammalian species, the prospect of farmed fish being contaminated with infectious mammalian PrP^Sc, or of a prion disease developing in farmed fish is alarming and requires further evaluation.