《An enzyme inhibitor》由会员分享，可在线阅读，更多相关《An enzyme inhibitor（5页珍藏版）》请在金锄头文库上搜索。
1、EXMENES DE INGLES II FACULTAD DE BIOQUIMICA Y CS. BIOLGICAS1) SMALLPOX VIRUS WINS STAY OF EXECUTIONThe debate over what should be done with variola has been rumbling on for years. The chief argument of those calling for destruction is that the virus is too dangerous to be allowed to “live”. Infected
2、 people have a 20% to 40% risk of dying, and in 1967 alone, variolas last year in the wild, it infected some 10 million people. By now, the destructionists say, people will have lost their immunity to variola, and no containment facility is 100% safe against accidental escape of the virus or terrori
3、st attack. “If there were an outbreak today, about a million people could die or go blind from the disease in the several months it would take to get enough vaccine produced”, says Ghendon. If researchers want to study the virus, he adds, they can use cloned variola DNA or the nucleotide sequences t
4、hat have been made of several strains of the viruss genome. “ I cannot understand why anybody would want to study the virus of a disease that no longer exists when there are micro-organisms emerging or re-emerging that are real public health threats today ,” he says.Those arguing against immediate d
5、estruction say that the slight risk of the virus escaping is outweighed by the wealth of scientific information to be obtained from the live virus about its virulence, its pathogenic mechanisms, and its potential in screening drugs for other viral diseases, including AIDS. Should variola be destroye
6、d, some ecologists argue, it would also constitute the first deliberate eradication of a biological species. “There is no doubt that some information will be irrevocably lost by destroying the virus. But it is a hypothetical call as to how useful that information would be”.Biological Defense Establi
7、shments argue that with no international mechanism for verifying if a state has clandestine stocks of variola, no potential defense against possible future biological threats can be planned. What if such state changes the virus slightly, so that the existing vaccine is ineffective?. Samples of the o
8、riginal live virus would be needed to develop rapid tests for smallpox virus attacks as well as new vaccines.With the death sentence on variola growing ever more complicated, WHO (World Health Organization) is resigned to a long fight. Says Kumate, “This is too important a matter to settle by a simp
9、le majority”.Science, vol 2671) Traduzca el texto.2) Indique si las siguientes afirmaciones son verdaderas o falsas.a) El virus de la viruela podra ser til en la investigacin de drogas contra el Sida.b) Las probabilidades de que una persona infectada viva son del 20 al 40%.c) No existen mecanismos i
10、nternacionales para el control de los stocks del virus de la viruela.d) No es posible usar el DNA del virus de la viruela clonado para investigaciones.e) El virus de la viruela se considera un virus peligroso para su uso en investigacin3) Exponga clara y brevemente:a) Tres argumentos a favor de la e
11、rradicacin del virus de la viruela.b) Tres argumentos en contra de su erradicacin.4) Seleccione la alternativa correcta (de acuerdo con el texto)a) El virus de la viruela I) fue exterminado totalmente II) fue controlado III) existe, pero en laboratorios.b) En el caso de un nuevo brote de viruela I)
12、todos podramos resistir la infeccin II) nadie podra resistir la infeccin III) habra muchas muertes.c) La informacin que se perdera destruyendo al virus I) es imprescindible II) no es imprescindible III) no se sabe.d) I) Existen II) No existen III) Se estn investigando otras formas de realizar estudi
13、os basados en el virus de la viruela.e) I) Es posible II) No es posible III) Tal vez se pueda encontrar algn lugar de donde el virus no pueda escapar.2) CANCER: A FAILURE OF IMMUNITY?The theory that declining immunocompetence is an underlying factor in the causation of both aging and cancer is appea
14、ling but raises some knotty issues. The concept is based on several assumptions: that tumor cells carry specific antigens; that competent immune systems recognize these antigens and destroy tumor cells; and that cancer would develop only if the immune response to antigens on tumor cells were somehow
15、 muted or the individual were immunodeficient.Proponents of this theory claim that the increased incidence of cancer in older people could be explained by age-associated tumors. Unlike tumors that are induced in experimental animals by chemicals or viral agents, most human tumors have weak or no dem
16、onstrable tumor antigens. Furthermore, when being profoundly immunocompromised, as in infection with HIV (Human immunodeficiency virus, the virus that causes AIDS) or after corticosteroid therapy to prevent organ transplant rejection, the tumors patients develop are usually lymphomas (cancer of the lymphatic system) or the form of skin cancer called Kaposis sarcoma rather than the broad spectrum of tumors e.g., lung, colon, breast, prostate- observed in older p
