外星人雖然有高科技,不過那群外星人是智商不高的勞工階級。在被接送下來後,入住南非的外星人中有部分被人類帶壞從事犯罪和破壞活動,人類對外星人的同情漸失,從而導致的了政府對其進行人口控制的需求。將這些維持治安的工作發包給民營的「國聯總部」(Multi-National United ,簡稱MNU)。
外星族群與人類的衝突已經發展到最嚴重的關頭,MNU開始驅除外星族群離開第九區,主角是MNU的當地負責人Wikus Van De Merwe,他的任務是要逼迫外星人簽下移居同意書。他在執行任務時耍寶感染上不明流體並變異,DNA發生變化。Wikus很快就成為通緝要犯,也是最有價值的逃亡者,因為他就是解開外星科技秘密的關鍵。
Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3418-21.
New studies on the heat resistance of hamster-adapted scrapie agent: threshold survival after ashing at 600 degrees C suggests an inorganic template of replication.
Brown P, Rau EH, Johnson BK, Bacote AE, Gibbs CJ Jr, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. brownp@ninds.nih.gov
One-gram samples from a pool of crude brain tissue from hamsters infected with the 263K strain of hamster-adapted scrapie agent were placed in covered quartz-glass crucibles and exposed for either 5 or 15 min to dry heat at temperatures ranging from 150 degrees C to 1,000 degrees C. Residual infectivity in the treated samples was assayed by the intracerebral inoculation of dilution series into healthy weanling hamsters, which were observed for 10 months; disease transmissions were verified by Western blot testing for proteinase-resistant protein in brains from clinically positive hamsters. Unheated control tissue contained 9.9 log(10)LD(50)/g tissue; after exposure to 150 degrees C, titers equaled or exceeded 6 log(10)LD(50)/g, and after exposure to 300 degrees C, titers equaled or exceeded 4 log(10)LD(50)/g. Exposure to 600 degrees C completely ashed the brain samples, which, when reconstituted with saline to their original weights, transmitted disease to 5 of 35 inoculated hamsters. No transmissions occurred after exposure to 1, 000 degrees C. These results suggest that an inorganic molecular template with a decomposition point near 600 degrees C is capable of nucleating the biological replication of the scrapie agent.
通訊作者Daniel C. Gajdusek (1923-2008),於1976年因庫魯病(Kuru)的研究和Baruch S. Blumberg (1925-)共同榮獲諾貝爾生理醫學獎。他們在2004年又發表了一篇論文,在模擬焚化爐的條件下重現了他們的實驗結果。
Environ Sci Technol. 2004 Nov 15;38(22):6155-60.
Infectivity studies of both ash and air emissions from simulated incineration of scrapie-contaminated tissues.
Brown P, Rau EH, Lemieux P, Johnson BK, Bacote AE, Gajdusek DC.
Laboratory of CNS Studies, National Institute of Neurological Disorders and Stroke, and Div. of Environmental Protection, Office of Research Facilities Development and Operations, NIH, US Dept. of HHS, Bethesda, MD 20892, USA. paulwbrown@comcast.net
We investigated the effectiveness of 15 min exposures to 600 and 1000 degrees C in continuous flow normal and starved-air incineration-like conditions to inactivate samples of pooled brain macerates from hamsters infected with the 263K strain of hamster-adapted scrapie with an infectivity titer in excess of 10(9) mean lethal doses (LD50) per g. Bioassays of the ash, outflow tubing residues, and vented emissions from heating 1 g of tissue samples yielded a total of two transmissions among 21 inoculated animals from the ash of a single specimen burned in normal air at 600 degrees C. No other ash, residue, or emission from samples heated at either 600 or 1000 degrees C, under either normal or starved-air conditions, transmitted disease. We conclude that at temperatures approaching 1000 degrees C under the air conditions and combustion times used in these experiments, contaminated tissues can be completely inactivated, with no release of infectivity into the environment from emissions. The extent to which this result can be realized in actual incinerators and other combustion devices will depend on equipment design and operating conditions during the heating process.
在大量閱讀科學文獻以及歐美的防範措施後,我得由衷地告訴大家,變異性朊毒體(PrP(Sc))這東西,實在是太太太變態了!專家可能只不過是訓練有素的狗,不過PrP(Sc)的天殺可怕變態程度,真的讓我們這些受遺傳學、分子物學家、微生物學、生物化學等生物學專業訓練的人頓時差點連狗都不如了XD 有實驗證實,用600 °C的高溫把感染了PrP(Sc)的腦組織烤15分鐘化成灰了,灰燼居然還有感染力(Brown P. et al. Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3418-21. & Brown P. et al. Environ Sci Technol. 2004 Nov 15;38(22):6155-60.),這實在是太超出生物學知識的認知範圍了。
很多人也仍質疑vCJD是否能經由輸血感染。事實上,這是相當有可能的(Ironside JW, Head MW. J Thromb Haemost. 2003 Jul;1(7):1479-86., Peden AH, et al. Lancet. 2004 Aug 7-13;364(9433):527-9., Llewelyn CA, et al. Lancet. 2004 Feb 7;363(9407):417-21., Peden AH, et al. Folia Neuropathol. 2005;43(4):271-8., Ironside JW. Haemophilia. 2006 Mar;12 Suppl 1:8-15; discussion 26-8., Dolan G. Haemophilia. 2006 Mar;12 Suppl 1:16-20; discussion 26-8.)。或許有些人還認為動物的肌肉(也就是我們最常吃的肉)不會出現PrP(Sc),不過開始有愈來愈多的證據顯示肌肉已不再是PrP(Sc)的禁地了(Beekes M, McBride PA. FEBS J. 2007 Feb;274(3):588-605.)。
更糟的是,在近廿卅年來,愈來愈多野生動物,尤其是北美的鹿群感染PrP(Sc),並且把PrP(Sc)四處趴趴走擴散傳播(Williams ES. Vet Pathol. 2005 Sep;42(5):530-49., Watts JC, et al. PLoS Pathog. 2006 Mar;2(3):e26., Sigurdson CJ, Aguzzi A. Biochim Biophys Acta. 2007 Jun;1772(6):610-8., Beekes M, McBride PA. FEBS J. 2007 Feb;274(3):588-605.)。很多科學證據顯示鹿與鹿之間會傳染PrP(Sc),有可能是死亡的鹿污染了土壤和草,不過還沒有人敢下定論說鹿是吃下受PrP(Sc)污染的草而中標的。鹿的感染性PrP(Sc)是哪來的,似乎也不清楚。鹿在六十年代就有PrP(Sc)疾病的案例,比牛早了約廿年吧。所以也很難說是牛傳染鹿。把鹿的感染性PrP(Sc),以腦室注射的方式,可以感染牛、羊、小鼠、鼬獾、黃鼠狼、倉鼠和松鼠猴,還沒有證據顯示上述動物吃下鹿的PrP(Sc)會得病,除了駝鹿例外(Williams ES. Vet Pathol. 2005 Sep;42(5):530-49.)。不過最近有個研究居然發現,山獅會柿子挑軟的吃,針對發病的鹿下口,大啖充滿PrP(Sc)鹿肉(Krumm CE, et al. Biol Lett. 2009 Oct 28. [Epub ahead of print])。
在討論這個問題前,先讓我介紹一本書,Steven D. Levitt和Stephen J. Dubner的Freakonomics : A Rouge Economist Explores the Hidden Side of Everything,其中文版書名《蘋果橘子經濟學》(大塊文化出版)。作者Steven D. Levitt是芝加哥大學的經濟學教授,Stephen J. Dubner是《紐約時報》和《紐約客》的專欄作家。眾所皆知,芝加哥大學的經濟系是出最多諾貝爾獎的,大師雲集,不過Steven D. Levitt雖然是John Bates Clark Medal的得主(該獎每兩年頒給四十歲以下的最傑出美國經濟學家),卻自詡為流氓經濟學家(a rogue econimist),向來以不務正業自居,書中大部分題目是他自己的一手研究。(請參考〈相撲手經濟學?〉)
對文 〈群魔亂舞的美國牛肉〉中的政治問題,這裡就不作討論了,畢竟政治取向是個人的選擇。 〈群魔亂舞的美國牛肉〉中,關於美國農業及畜牧業的探討,主要依據是Michael Pollan的The Omnivore's Dilemma: A Natural History of Four Meals。Michael Pollan是加州大學柏克萊分校(University of California, Berkeley)的新聞學教授。The Omnivore's Dilemma曾榮獲《紐約時報》(The New York Times)評選2006年年度十大好書。The Omnivore's Dilemma中文版《到底要吃什麼?:速食、有機和自然野生食物的真相》由蕭秀姍和黎敏中翻譯,久周出版文化事業有限公司出版。
牛原本是吃草的,歐美國家為了降低飼養成本,一些摻雜抗生素、激素、化肥、殺蟲劑的蛋白質添加劑加入以玉米為主的飼料中,並且還普遍將肉和骨頭的混合物(肉骨粉)加入飼料。先前一直認為是對患病牛的遺體處理出現問題,因此藉由牛吃牛隻肉骨粉的方式,使疾病在健康牛群中傳播開來。這一點在Michael Pollan的The Omnivore's Dilemma中的第四章The Feedlot: Making Meat中提到。
玉米飼養出來的美國病牛肉,不僅脂肪含量高到異常,脂肪組成更不利心血管健康。正常的肌肉是不會均勻地分佈脂肪的,那些乍吃之下美味的牛肉,其實都是變質、畸型、異常的肌肉。美國人的心血管疾病罹患率節節上升,很大部分是國民的飲食習慣造成,例如吃了太多不健康的美國病牛肉。這點在Michael Pollan的The Omnivore's Dilemma和另一本書In Defense of Food: An Eater's Manifesto中有提到。In Defense of Food有中譯本《食物無罪:揭穿營養學神話,找回吃的樂趣!》(曾育慧譯,平安文化出版)
有人會爭論道,並非所有美國牛都吃葷吧?是的,的確有純吃草的美國牛,可是吃草的牛需要更多土地和生長時間,成本很高,所以在美國,草食牛的牛肉,是在高級超市裡賣的,比吃葷的牛肉貴好幾倍,連美國內銷都不夠,美國外銷的都是吃葷的牛肉啦!這在Michael Pollan的The Omnivore's Dilemma和In Defense of Food中有提到,加上我在美國的生活經驗。
為了讓美國的玉米田裡能旺盛地長出源源不絕的玉米,並且讓石化工業能夠從中獲益,美國就得到處去爭奪石油!所以說誇張一點,美國鮮嫩多汁的牛肉裡粉紅色的牛血,其實就是十幾萬無辜伊拉克人民的鮮血!這是純政治指控,嫌我跳得太超過,可以看這篇《哈潑雜誌》(Harper's Magazine)的文章:The oil we eat: Following the food chain back to Iraq。《哈潑雜誌》是美國第二老的知性月刊。
好吧,石化工業、機械工業、農業、畜牧業、生技公司、食品加工業、醫療業和保險業加起來的金錢和選票夠可怕了吧?這就是為何美國政府拚了老命,被外國人痛罵蠻橫、霸道、無理、沒良心,也要用自由貿易為藉口,強迫把病牛肉和病牛雜賣到其他國家!然後他們再把賺來的錢去中東購買石油來造成全球暖化,中東國家再把賺來的美金資助恐怖份子作亂......這是政治推論,不過Thomas L. Friedman的Hot, Flat, and Crowded: Why We Need a Green Revolution有指出美國和恐怖分子的關係。Thomas L. Friedman是《紐約時報》的專欄作家。