Call for your Health

Yes, in many instances they do. They also control. Suppose you are undergoing treatment by x-rays for a painful shoulder, shingles, or a similar benign illness. The x-ray tube from which the x-ray beam comes is centered over the affected area and the machine turned on. The treatment may be repeated a number of times, depending on how quickly the condition clears up.

Patients with thyrotoxicosis (an overactive thyroid gland) often are treated to an “atomic cocktail” by the radiologist. The “cocktail” is a carefully determined amount of radioactive iodine. The thyroid gland takes up iodine. When radio­active, this iodine gives off a continuous stream of beta and gamma rays. These rays slow down the overactive thyroid cells and the gland returns to its normal working condition.

Suppose someone you know has a cancerous growth. If his trouble has been discovered in the early stages he has a good chance of being cured. First, the radiologist will learn the patient’s history by talking with the patient and his referring doctor. He also will do his own examination of the patient. Then he will review the report on the tissue, or actually go over the microscope analysis of the small bit of tissue which has been taken from the growth (the biopsy) with the pathologist.

He then develops the plan of radiation treatment best suited for the patient. He maps out a schedule of treatment fit­ting the radiation to the particular growth. He must decide how many treatments given within a certain number of days will deliver the amount of radiation necessary to destroy or control the growth. In many instances, by using many small treatments, it is possible to bombard the growth and the area around it with a large dose of radiation with­out permanently damaging the healthy tissues. This allows them to recover with the least discomfort to the patient.

What do Radiation Treatments Feel Like

There is no sensation during the time the x-rays or gamma rays are being ad­ministered. After two or three weeks of therapy the patient may notice that his skin appears to be sunburned over the treated area. Actually, his “sunburn” is very similar to that which develops from over-exposure to the sun. This reaction in the skin is part of the treatment and will gradually disappear. Perhaps at the same time the patient may also complain of nausea and loss of pep. This is called “radiation sickness.” Fortunately, most patients do not experience this condition. If it does occur, it can be readily controlled. In any event, it will disappear as soon as the series of treatments are over.

The set point theory of weight control also reflects the role of genetics. Proponents of this theory suggest that the body works to maintain a certain weight. More specifically, each person has an internal set point for fatness, sometimes called the a dipostat, that the body seems to regulate by adjusting hunger, appetite, food intake, and energy expenditure. Re­searchers have demonstrated that human and animal subjects who have been put on low calorie or high­calorie diets lose and gain only to a certain level. When the diet ends, food consumption increases and they return to their approximate original weight.

How the body determines its set point is not known. One hypothesis is that the body is able to adjust its energy expenditure by varying how efficiently muscles burn calories. Researchers at New York’s Rockefeller University discovered that a dieter’s metabolism slows down after losing weight, so that doing the same amount of exercise at the new weight burns fewer calories. The researchers found that after losing 10% of their body weight, newly slimmer patients expended 15% less energy than expected for someone of similar size and body composition. The system also works in the other direction; when patients gained weight, their metabolism increased 16%. After a quick weight gain, the metabolism speeds up to make muscle activity burn more calories, quickly bringing the body back to its normal weight-its set point. Whatever direction a person’s weight goes, up or down, losing weight or gaining weight, the body tends to resist that change.

Can a person change his or her set point? Proponents of the set point theory think that the set point does shift over time in response to behavioral factors: eating a high-fat diet tends to raise the set point for fatness and regular physical activity tends to lower it. This shift may be so slight and gradual as to go unnoticed for years.

Some proponents of the set point theory suggest that because some people are genetically programmed to have unwanted pounds, efforts to eliminate fat with diet, exercise, or both are doomed. The body can shut down its calorie-losing mechanism by lowering metabolism and can stimulate appetite to the point that a person must have food.

Other proponents of the set point theory argue that vigorous regular exercise lowers the set point and thereby lowers the level of fat the body will accept and defend. Exercise induces the body to stabilize at a lower body weight, which is precisely what dieters are trying to do. Unfortunately there is no formula for calculating that a specific amount of exercise will result in the loss of a certain number of pounds. Individual response to exercise varies in ways similar to the differences in response to dieting. Still, exercise seems to be the best way to over power the body’s set point. This is a classic case of a genetic inclination being modified through appropriate lifestyle behavior. It supports the idea that heredity (that is, obesity) is not destiny. Living a healthy life-through regular exercise and sound nutritional habits cannot negate heredity, but it can modify it.

In one sense, all laboratory tests are used as a guide to treatment, since they promote accurate diagnosis. In this section, however, reference is made to the use of laboratory tests to select the type of treatment to be used, to determine how much treatment is required, to confirm that the desired effect is being obtained, and to avoid harmful side effects of treatment. The need for tests of this type is greatest in those chronic diseases where treatment must be continued for a long time, perhaps for life.

Tests of Antibiotic Efficacy

In a dangerous infection such as meningitis, it is extremely important to obtain an optimum therapeutic effect without delay. Since meningitis may be due to different bacteria, and each of these may respond differently or not at all to the various antibiotic drugs, it is common practice to test the various antibiotic drugs directly against the bacteria that are present in the particular case. This can be done in the following way:

Spinal fluid from the patient is mixed with melted agar in a sterile dish and the warm mixture is allowed to cool and solidify. Tiny paper disks, each of which has been impregnated with a different antibiotic, are dropped onto the surface of the agar and the dish is set aside for several hours in an incubator. The bacteria that were present in the patient’s spinal fluid begin to multiply and form “colonies” in the medium, except that where they are in contact with the paper disks their growth may be modified by the antibiotic.

If all bacterial growth is suppressed about the paper disk saturated with tetracycline, but growth is abundant about the disk saturated with penicillin, it is clear that tetracycline is a better drug than penicillin to use in the treatment of this particular patient with meningitis. The test is a combination of spinal fluid culture and antibiotic sensitivity.

Dosage Regulation

Probably the oldest use of laboratory tests to regulate drug dosage is in the diabetic patient. Some diabetics have a different requirement of insulin from day to day, depending upon appetite, diet, exercise, colds and the like. If the regular dose of insulin is sufficient, the urine test for glucose will be negative. If it is insufficient, the test may give a green, yellow or red color, depending upon the amount of glucose present. The doctor teaches the patient how to test his own urine and to regulate the dose of insulin depending upon the color of the urine test. From time to time the diabetic patient must also have a glucose test on blood, so as to avoid over dosage of insulin.

The following are other examples of the use of laboratory tests to guide treatment. After an attack of coronary thrombosis, many patients are given drugs to reduce the clotting tendency of their blood. The effect must be precisely controlled by coagulation tests, since overdose of the drug could cause a tendency to hemorrhage.

X-rays, radium and drugs used in the treatment of cancer sometimes destroy blood cells as well as cancer cells; occasional counts must be taken of white cells, red cells and platelets to make sure that this harmful effect is avoided. Some drugs used in the treatment of high blood pressure produce in some patients a condition resembling a special form of sensitivity disease known as lupus eurhythmics,. special blood examinations (“LE prep”) can anticipate this effect.

Transfusions

Of life-saving importance in certain diseases is the use of blood transfusions. However, different people have different types of blood and it would be extremely dangerous to give a patient blood of a type different from his own. To detect these types and determine compatibility between donor’s and recipient’s blood, blood group and Rh tests must be carried out meticulously.

Similar tests (blood group and Rh) are of importance in determining whether the blood of an unborn baby is compatible with that of its mother. If incompatibility is present, it may be necessary to give the baby an “exchange transfusion” immediately after birth.

Frozen Section

The surgeon often calls upon the pathologist to help him decide whether a lump in the breast should be simply removed or whether the whole breast and the nearby lymph nodes should also be removed. This test, known as the “frozen section,” is performed while the patient is under anesthesia. The surgeon removes the lump and passes it to the pathologist who freezes a portion of it in a jet of carbon dioxide gas. Once frozen, a very thin slice or section is cut, stained with a dye, mounted on a glass slide and examined under the microscope. If cancer is present, as determined by the pathologist, the surgeon will normally remove the entire breast and related tissue so as to “get around” the cancer. If the pathologist determines that the lump is benign, the surgeon ordinarily does not remove the remainder of the breast