Here is a practice Reading comprehension Test for the Dental Admissions Test (DAT). To simulate a real Dental Admissions Test (DAT) give yourself no more than 24 minutes to complete the test.
Directions: Read each passage. Then, choose the best answer to each question that follows.
Asthma is a chronic, long-term lung condition characterized by these four basic abnormalities:
• narrow airways
• inflamed airways
• airways that are overly sensitive to particular triggers, such as certain medications, infections, irritants, allergens, exercise, and dry, cold air
• the secretion of excess mucus in the lungs
In the past, explanations of asthma focused on what was happening within the lungs and the airways. An asthma attack was most often described as bronchoconstriction—the constriction, or narrowing, of the bronchial system, the muscles that surround the airways. Consequently, the aim of treatment was bronchodilation, or getting the bronchial muscles to relax, which allowed the airways to dilate, or open up. Inhalers provided bronchodilators, medication that caused this effect. A person with asthma who felt an attack coming on could expand his or her airways by using an inhaler that contained a bronchodilator.
This view of asthma led scientists to divide asthma into two types: extrinsic and intrinsic. Extrinsic asthma was seen as being triggered by a foreign substance entering the lungs. Intrinsic asthma was seen as being triggered by some inexplicable process within the body that no one really understood. However, this explanation of asthma is no longer considered valid. Scientists now suspect that much so-called intrinsic asthma was actually triggered by a foreign substance that was just not identified.
More recent explanations of asthma suggest that it is a disordered immune response that causes cells to release certain chemical molecules into the airways. This view sees asthma as a disorder in which the body reacts and overreacts to stimuli in the environment. Some of these stimuli are not really dangerous, such as cold air and dust mites. Some of them may actually be dangerous, such as viruses and pollution. Therefore, what doctors used to call intrinsic asthma is now explained as the body reacting to a perceived threat.
No matter what it is that triggers an asthma attack, the body’s reaction to the stimulus is very harmful. As it deals with what it perceives as an attack by a dangerous foreign substance, the body goes into an asthmatic reaction. The bronchial lining—the tissues lining the airways—becomes inflamed. As it swells and turns red, it tends to narrow the air passages. Inflammation has another effect as well: it makes the passages supersensitive to perceived dangers. While a normal lung would ignore a speck of house dust, an asthmatic lung might react strongly to it. The airways of an asthmatic are chronically inflamed and therefore extremely sensitive to the wide variety of triggers that make them contract.
Does the use of bronchodilators help or harm the asthmatic? Many doctors now see the frequent use of bronchodilators as a problem, for they treat only the symptoms and not the causes of the condition. An asthmatic might rely on the bronchodilator to open up the airways, even as the lungs become increasingly inflamed. The more inflamed the lungs get, the tighter the airways get, and the more medication is needed to open them up. The asthmatic might end up using the inhaler more and more often, as its effects last for shorter and shorter periods. The danger is that one day the bronchodilator might not be able to open up the exhausted airways.
1. A good title for this selection would be:
a. “Changing Attitudes toward Asthma”
b. “Intrinsic and Extrinsic Asthma”
c. “Inhalers—Good or Bad?
d. “Avoiding Asthma Triggers”
2. A person with asthma has abnormalities in
a. The airways
b. The lungs
c. The airways and the lungs
d. The bronchial system
3. Bronchodilation can be described as:
a. Constriction of the bronchial muscles
b. A disordered immune response
c. An abnormality of the lungs
d. Relaxation of the bronchial muscles
4. Which of the following is not a characteristic of asthma?
a. Narrow, inflamed airways
b. High blood pressure
c. Overly sensitive airways
d. Excess mucus in the lungs
5. According to the article, scientists now believe that asthma:
a. Is completely treatable by bronchodilators
b. Cannot be treated by bronchodilators
c. Can be divided into two types: intrinsic and extrinsic
d. Is an overreaction to environmental stimuli
6. The purpose of using a bronchodilator is to:
a. Expand the airways
b. Constrict the airways
c. Cure asthma
d. Zap any dangerous external stimuli
7. The last paragraph suggests that:
a. Bronchodilators do more harm than good
b. Asthmatics should never use bronchodilators
c. The body builds up resistance to the medication in the bronchodilator
d. asthmatics cannot really be helped
8. You can infer that the author would be in favor of:
a. Encouraging more frequent use of bronchodilators by asthma patients
b. Treating the symptoms and not the underlying causes of asthma attacks
c. Developing more efficient ways of getting bronchodilators to work
d. Preventive measures, such as the use of anti-inflammatory medications for asthma sufferers
Osteoporosis is a disease that affects mainly postmenopausal women, although it can affect men and younger women as well. The word comes from the Greek osteon, meaning “bone,” and the Latin porus, meaning “pore.” Osteoporosis causes a decline in the density and mass of bones, leaving them porous, thin, weak, and vulnerable to fractures. Approximately 10 million Americans suffer from osteoporosis today. The disease causes about 1.5 million snapped wrists, broken hips, crushed vertebrae, and other bone fractures annually. In addition, another 34 million Americans have osteopenia, or low bone mass, and are at risk of developing osteoporosis.
Because it produces no obvious symptoms until it is well advanced, osteoporosis is called the “silent disease.” It can go undetected for years, finally revealing itself in a sudden bone fracture. In addition to broken bones, signs of advanced osteoporosis include “dowager’s hump” (a rounded hump in the upper back), stooped posture, loss of height, a curved spine, and severe back pain. Each of these conditions is the result of vertebrae that have collapsed under the strain of supporting the body.
Osteoporosis is a significant cause of disability and death. Of the 300,000 Americans a year that break a hip because of osteoporosis, about 150,000 will subsequently permanently rely on canes or walkers to get around. Twenty percent will have to go to a nursing home. About one in five patients with hip fractures die within a year, usually due to complications related to the fractures. Furthermore, studies have shown that people who have osteoporosis have a greater risk of heart disease and stroke.
The best treatment for osteoporosis is prevention—building the densest, strongest bones possible during the peak bone-building years (up to about age 20), and then maintaining bone mass and density after that. To do this, a person has to eat a diet rich in calcium and vitamin D, perform plenty of weight-bearing and resistance-training exercise, and avoid smoking and excessive amounts of caffeine and alcohol. If a person has not followed this regimen and is diagnosed with osteoporosis, he or she can reverse or at least reduce the effects of the disease by adopting these habits. In addition, certain medications can also help restore bone density. Bisphosphonate drugs such as alendronate (brand name Fosamax), ibandronate (brand name Boniva), and risedronate (brand name Actonel) are often prescribed. These drugs are so new, however, that their long-term effects remain unknown. Some controversy surrounds their use.
9. The demographic group that is most susceptible to osteoporosis is
a. Young women
b. Young men
c. Postmenopausal women
d. Greek and Latin women
10. Based on the information in the article, you can infer that an osteopath is a doctor who treats
b. Older people
11. Osteopenia is a condition that is ______ osteoporosis.
a. Less serious than
b. More serious than
c. About the same as
d. Harder to treat than
Use the following information to answer Question 12:
I. “dowager’s hump”
II. back pain
III. snapped wrists
IV. loss of height
12. Vertebrae that collapse under the strain of supporting the body cause?
a. I and II
b. I, II, and III
c. I, II, and IV
d. I, II, III, and IV
13. The number of patients with hip fractures who die within a year is about?
c. 1.5 million
Use the following information to answer Question 14:
I. Heart disease
IV. Alzheimer’s disease
14. According to the article, people with osteoporosis also have an increased risk of
a. I and II
b. I and III
c. II and III
d. II and IV
15. Based on the article, you can infer that smoking
a. Causes lung cancer
b. Can help restore bone density
c. Has unknown long-term effects
d. Has a negative effect on bone density
16. Controversy surrounds the use of bisphosphonates because?
a. Their long-term effects are unknown
b. They do not help restore bone density
c. They are new
d. They have no effect on osteoporosis
Practice guidelines issued by the American Psychiatric Association indicate that lithium is the preferred treatment for manic-depressive illness (also called bipolar disorder). For patients who are experiencing acute mania, however, lithium is rarely used alone. The reason for this is that the drug takes some time to show its effects. This “lag time” may range from a few days to three weeks in duration. Because of this, lithium is often combined with other drugs for the acute stages of mania.
Lithium also seems to be especially effective during the depressed phase of manic-depressive illness. About 60 to 80 percent of patients with acute depression respond to the drug, although full response might take up to four weeks.
As for long-term treatment of manic-depressive patients, studies have shown that lithium is effective as a preventive medicine for both manic and depressive episodes. Over 200 patients were studied for a period ranging from three months to four years. Of those patients who received lithium during the study period, about 35 percent experienced a relapse. Of those who received a placebo during the same period, about 80 percent experienced a relapse. Although lithium does not help all patients, we can conclude from these results that lithium doubles the chance of improvement for most.
Side effects of lithium include a reduction in thyroid function. In only about 5 to 10 percent of patients is this hypothyroidism medically significant. Patients on lithium need regular checks of their thyroid hormones to determine if they need to be replaced by an oral preparation.
About 23 percent of patients on lithium develop polyuria-polydipsia, a syndrome of excessive urination and thirst. For such patients, kidney function should be checked and the lowest possible dose of lithium prescribed. The problem can be helped with the use of a diuretic such as furosemide or amiloride. If necessary, the patient might start taking valproate or carbamazepine instead of lithium.
Some patients on lithium develop a condition called postural tremor, a fine tremor of the hands when the arms are held in a sustained posture. About 33 percent of the patients develop this condition, which can be helped by reducing lithium intake to the lowest effective dose or by adding propranolol.
Another possible side effect of lithium is reduced memory and concentration. As with many other side effects of lithium, this can be controlled by using the lowest effective dose of lithium.
Weight gain of more than 10 pounds occurs in about 25 percent of patients on lithium. It is not known whether this is caused by increased food intake or to changes in the metabolism of sugars and insulin. This level of weight gain is not dangerous for most patients. However, for those patients who have medical conditions that are exacerbated by weight gain and in those already overweight when treatment begins, such weight gain can be of considerable concern. Even so, patients should be very cautious about taking weight-loss drugs, for these often have significant side effects of their own, such as worsening psychiatric symptoms.
Another side effect of lithium is that it can irritate the stomach and intestine and may cause diarrhea or nausea. These problems can be minimized if the patient takes lithium with a meal. Divided doses or sustained-release medications can reduce nausea, but sustained-release medications may worsen diarrhea.
If side effects, lack of effectiveness, or sustained periods of normal mood indicate that lithium should be discontinued, the discontinuation must be gradual. Rapid or sudden withdrawal of lithium often causes further episodes of illness. Of those patients who stop taking lithium abruptly, about 50 percent will have a relapse (usually a manic episode) within five months. Some reports suggest that such relapses are then less responsive to treatment, but this has not been confirmed in other controlled studies. To reduce the risk of “withdrawal mania,” lithium should be discontinued by 12–25 percent of the original dose every 60 days.
17. What is the main idea of the article?
a. It takes up to three weeks for lithium’s effects to be observable
b. For most manic-depressive patients, lithium doubles their chance of improvement
c. Lithium is useful in treating manic-depressive illness, but it has certain side effects
d. Weight gain is a serious side effect of lithium use
18. If 100 patients with acute depression were given lithium, about how many would respond favorably?
a. 5 to 10
d. 60 to 80
19. While taking lithium as a preventive treatment for both manic and depressive episodes, what percentage of patients can expect positive results?
a. 35 percent
b. 65 percent
c. 80 percent
d. 90 percent
20. Based on the article, what would probably be done if a patient taking lithium suffered from hypothyroidism?
a. The doctor would prescribe an oral medication to replace thyroid hormones.
b. The doctor would immediately take the patient off lithium.
c. The patient would be given a diuretic.
d. The patient would be put on valproate or carbamazepine.