问题 多项选择题 共用题干题

患儿,女,5个月,因面色苍白3个月入院,无出血倾向,无发热,无咯血及黑便,无尿色明显加深,无皮疹。面色苍白逐渐加重,分别在入院前半个月及入院前3个月于院外诊断重度贫血而输血两次,共100ml,输血后短暂面色红润,很快又苍白。病后曾服用"补血药"治疗,病情无好转。体检:生长发育尚好,无皮疹及黄疸。呼吸急促,双肺无显著异常,心前区闻及柔和2/6SM。肝肋下3cm,脾肋下2.5cm。

检查报告血清结合珠蛋白:0.71/L(0.3~2.1g/L),血清铁:正常,铁饱和度61.5%;血红蛋白电泳:HbF4.2%,HbA1.8%;父母血红蛋白电泳:正常;Coomb试验:直接间接均阴性。根据上述检查结果及病史,目前可以排除的疾病是()。

A.地中海贫血

B.缺铁性贫血

C.蚕豆病

D.遗传性球形红细胞增多症

E.白血病

F.自身免疫性溶血性贫血

G.消化道畸形

答案

参考答案:A, B, C, F

单项选择题
填空题

[A] The strain of HIV that was discovered in Sydney intrigues scientists because it contains striking abnormalities in a gene that is believed to stimulate viral duplication. In fact, the virus is missing so much of this particular gene-known as nef, for negative factor--that it is hard to imagine how the gene could perform any useful function. And sure enough, while the Sydney virus retains the ability to infect T cells--white blood cells that are critical to the immune system’s ability to ward off infection--it makes so few copies of itself that the most powerful molecular tools can barely detect its presence.

[B] If this speculation proves right, it will mark a milestone in the battle to contain the late-20th century’s most terrible epidemic. For in addition to explaining why this small group of people infected with HIV has not become sick, the discovery of a viral strain that works like a vaccine would have far-reaching implications. "What these results suggest," says Dr. Barney Graham of Tennessee’s Vanderbilt University, "is that HIV is vulnerable and that it is possible to stimulate effective immunity against it."

[C] But as six years stretched to 10, then to 14, the anxiety of health officials gave way to astonishment. Although two of the recipients have died from other causes, not one of the man’s contaminated blood has come down with AIDS. More telling still, the donor is also healthy. In fact his immune system remains as robust as if he had never tangled with HIV at all. What could explain such unexpected good fortune

[D] At the very least, the nef gene offers an attractive target for drug developers. If its activity can be blocked, suggests Deacon, researchers might be able to bring the progression of disease under control, even in people who have developed full-blown AIDS. The need for better AIDS-fighting drugs was underscored last week by the actions of a U. S. Food and Drug Administration advisory panel, which, recommended speedy approval of two new AIDS drugs. Although FDA commissioner David Kessler was quick to praise the new drugs, neither medication can prevent or cure AIDS once it has taken hold. What scientists really want is a vaccine that can prevent infection altogether. And that’s what makes the Sydney virus so promising--and so controversial.

[E] A team of Australian scientists has finally solved the mystery. The virus that the donor contracted and then passed on, the team reported last week in the journal Science, contains flaws in its genetic script that appear to have rendered it harmless. "Not only have the recipients and the donor not progressed to disease for 15 years," marvels molecular biologist Nicholas Deacon of Australia’s Macfarlane Burnet Centre for Medical Research, "but the prediction is that they never will." Deacon speculates that this "impotent" HIV may even be a natural inoculant that protects its carriers against more virulent strains of the virus.

[F] But few scientists are enthusiastic about testing the proposition by injecting HIV--however weakened--into millions of people who have never been infected. After all, they note, HIV is a retrovirus, a class of infectious agents known for their alarming ability to integrate their own genes into the DNA of the cells they infect. Thus once it takes effect, a retrovirus infection is permanent.

[G] About 15 years ago, a well-meaning man donated blood to the Red Cross in Sydney, Australia, not knowing he has been exposed to HIV-1, the virus that causes AIDS. Much later, public health officials learned that some of the people who got transfusions containing his blood had become infected with the same virus; presumably they were almost sure to die.

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