次の英文を読んで、設問に答えなさい。

Little more than two decades ago, it was virtually inconceivable that taking a pill would be the treatment for peptic ulcers, i.e., sores in the lining of the stomach and small intestines.　Prior to the mid 1980s, most physicians and laypersons were convinced that ulcers were caused primarily by stress. They also believed that spicy food, excess stomach acid, smoking, and alcohol consumption played important secondary roles in ulcer formation. Today, we know otherwise, thanks to the pioneering work of Barry Marshall and Robin Warren, who received the Nobel Prize for their groundbreaking research that radically changed our thinking about ulcers and their treatment.

In1983, Marshall and Warren pinpointed a link between peptic ulcers and a curved bacterium, named Helicobacter or H. pylori, lurking in the lining of the stomach and intestines. The two scientists first discovered that H. pylori infection was common in people with ulcers, but uncommon in people without ulcers. To demonstrate that the microscopic invader was the (ア)culprit in producing ulcers, Marshall bravely (some might say foolishly) swallowed a cocktail of the organisms and developed a stomach irritation known as gastritis for several weeks. Still, Marshall's daring experiment wasn't conclusive. He ended up ( イ ) a bad stomach ache, but no ulcer. So he was not exactly able to show a direct tie between H. pylori and ulcer formation. This result actually isn't all that surprising given that although the bacterium is present in about half of all people, only about 10-15% of people who are infected by the organism develop ulcers.

The definitive link between H. pylori and ulcer formation came when independent researchers across the world cultured the bacterium, and demonstrated that treating H. pylori infection with strong antibiotics reduced the recurrence of ulcers dramatically. This finding was important because drugs that merely neutralize or inhibit the production ( ウ ) stomach acid can effectively treat ulcers in the majority of cases, but 50-90%of ulcers recur after treatment stops. The fact that antibiotics decreased the recurrence of ulcers by 90-95% provided strong evidence that H. pylori caused ulcers.

However, since the great majority of people infected with H .pylori don't develop ulcers, scientists realized that other influences　(エ:must) play a role, too. They discovered that excessive use of medications like aspirin and ibuprofen can produce ulcers by irritating the stomach lining. They also came to understand that stress, too, probably plays a role in ulcers, although studies show that the widespread belief that stress by itself causes ulcers is wrong. For example, psychological distress is associated with higher rates of ulcers in human and non-human animals. Moreover, stress is linked to a poor response to ulcer treatment, and stressful events, (オ:include) earthquakes and economic crises, are associated with increases in ulcers. Additionally, people with generalized anxiety disorder, a condition marked by worrying too much of the time about many things, are at heightened risk for peptic ulcers.

We now understand the fact that stress may contribute to the development of ulcers in terms of a bio-psycho-social perspective, which proposes that most medical conditions depend on the complex interplay of genes, lifestyles, immunity, and everyday stress. Stress may also exert an indirect effect on ulcer formation by triggering such behaviors as alcohol use and lack of sleep, which make ulcers more likely.

The verdict is still out regarding the precise role that stress plays in ulcer formation, although it is clear that stress isn't the only or even most important influence. In all likelihood, stress, emotions, and the damage generated by disease-producing organisms combine to create conditions ripe for the growth of H. pylori. So if you're having stomach problems, don't be surprised if your doctor suggests that you learn to relax - as he pulls out a pen and pad to write you a prescription for powerful antibiotics.

(Adapted from Scot O. Lilienfild et al., 50 Great Myths of Popular Psychology, Maiden and Oxford: Wiley-Blackwell, 2010, pp. 126-129)

• peptic ulcer:消化性潰瘍
• gastritis:胃炎
• recurrence:再発

設問

1. 次の英文が、本文の内容と一致している場合にはTを、一致していない場合にはFを記しなさい。
   • (1)Before 1983, most people believed that ulcers were caused mainly by stress.
   • (2)H. pylori infection is frequently found in people who do not suffer from ulcer.
   • (3)The successful treatment of H. pylori infection with strong antibiotics provides clear evidence that the bacterium plays a major role in ulcer formation.
   • (4)We know now for sure that stress alone causes ulcers.
   • (5)Nowadays, the most likely explanation for the causes of ulcer is H. pylori infection accompanied by such factors as stress, excessive use of medication irritating the stomach lining, etc.
2. 下線部(ア)の意味に最も近いと思われるものを、次のA～Dの中から一つを選び、記号で答えなさい。
   • A. person or thing responsible for causing a problem
   • B. person or thing unrelated to the problem under discussion
   • C. person or thing familiar to everyone
   • D. person or thing discovered for the first time
3. ( イ ) と ( ウ ) に入る最も適切な語を記しなさい。
4. ( エ ) と ( オ ) の語を適切な形に直しなさい。直す必要のない場合はそのまま記しなさい。