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Biomedical subjects

A Ward

Publications and source records attributed to A Ward.

At least 217 records · Page 12Linked to original sources
PubMed1978

A comparison of body fat determined by underwater weighing and volume displacement.

Two hydrostatic techniques, underwater weighing and water displacement, were used to determine body fat for 67 volunteer men between 25 and 61 yr of age (-/x=41 yr). All tests were administered in random order in the morning on the same day while subjects were in the postabsorptive state. Test-retest reliabilities for the underwater weighing and water displacement techniques were 0.995 and 0.96, respectively. The correlation between the two hydrostatic techniques was r=0.96. The mean percent fat determined by underwater weighing (-/x=20.1 +/- 6.4) and water displacement (-/x=19.4 +/- 6.1) were significantly different (t=28.16; df=65; P less than 0.001). These analyses showed that both techniques were reliable in measuring percent body fat, but produced slight systematic differences. Regression equations were provided to adjust for the difference.

Adipose Tissue↗
PubMed1978

Endometrial factors under treatment with oestrogen and oestrogen/progestogen combinations.

In a continuing prospective study, uterine curettage was undertaken on sixty-four patients attending a Menopause Clinic prior to consideration of gonadal hormone therapy. Two of these patients (3.1%) were found to have endometrial hyperplasia, and subsequently they were not given gonadal hormone therapy. Sixty-two patients with normal endometrium at pre-treatment curettage received cyclical oestrogen regimens or sequential oestrogen/progestogen treatments. Four (30.8%) of the thirteen patients in receipt of cyclical 'high-dose' oestrogens developed cystic glandular hyperplasia, whereas none of the patients taking either cyclical 'low-dose' oestrogens (thirty patients) or cyclical-sequential oestrogen/progestogen regimens (nineteen patients) developed endometrial hyperplasia. Among the patients with a normal endometrium, both before and during cyclical gonadal hormone therapy, regular withdrawal bleeding was experienced by thirty-two patients (51.6%). Breakthrough bleeding occurred in nine (14.5%), while twenty-one patients (33.9%) had no vaginal bleeding. Of the four patients with normal endometrium at pre-treatment curettage who subsequently developed endometrial hyperplasia during cyclical 'high-dose' oestrogen therapy, regular withdrawal bleeding was experienced by two patients, and in one of these breakthrough bleeding also occurred. Furthermore, in the four patients who developed endometrial hyperplasia, this condition occurred within six months in two patients and within 9 and 10 months respectively in the remaining two. In the nineteen patients receiving cyclical sequential oestrogen/progestogen regimens, all had regular withdrawal bleeding, while one patient had breakthrough bleeding during sequential therapy. It is concluded that in those climacteric patients who present with severe menopausal symptoms which necessitate the administration of high-dose oestrogen regimes it is necessary either to undertake both pretreatment uterine curettage or to add a progestogen to the oestrogen in a sequential regimen.

Climacteric↗
PubMed1976

A comparative analysis of four protocols for maximal treadmill stress testing.

The purpose of this investigation was to compare the results from four commonly used maximal treadmill stress tests: Balke, Bruce, Ellestad, and a continuous multistage running protocol. The results compared serial and maximal heart rate, metabolic demands, and ECG determinations. Fifty-one healthy men, 35 to 55 years of age, volunteered for this study and were dichotomized into trained and untrained subjects. Regression analyses showed all the tests to correlate highly. No significant differences were found between tests at maximum for V02, heart rate, and blood pressure, except for V02 for the Balke as compared to the running protocol (39 vs. 41 ml./Kg-min). The Balke protocol showed lower values at maximum in VE and RP than the other three tests as well as the most gradual rate of progression in MET cost (0.5 METS per minute). The increase for the Bruce and Ellestad tests was from 1 to 1.5 METS per minute, and a rapid initial increase (9 METS in the first 3 minutes) made the running test undesirable as a screening method. Although serial plots of heart rate and MET costs were similar to those previously reported for different population samples, the present data further refined these values. Finally, a nomograph comparing treadmill time and V02, max. for the Balke, Bruce, and Ellestad tests was developed from these data.

Adult↗
PubMed1976

Physiologic responses of men 49 to 65 years of age to endurance training.

A study was made of the effects of training for 30 minutes, three days a week for 20 weeks on certain physiologic measures of sedentary men between 49 and 65 years of age. Twenty-two subjects volunteered for the experimental group, and 8 others for the control group. Exercise sessions were conducted on a quarter-mile track and consisted of continuous bouts of walking and jogging. The average daily energy expenditures progressed from 228 to 365 kilocalories between weeks 4 and 20. For the same period, average exercise heart rates (HRs) progressed from 149 beats/minute (83 per cent maximum HR) to 155 beats/minute (91 per cent maximum HR). The experimental group showed significant increases in maximum oxygen intake (VO2 max) from 2.47 to 2.90 liters/minute (18 per cent) and in maximum pulmonary ventilation (VE max) from 105 to 121 liters/minute (BTPS), and decreases in resting HR, diastolic blood pressure, body weight, skinfold fat, and abdominal girth. Serum cholesterol and triglyceride levels and heart volume remained unchanged. The control subjects showed no significant changes. Regression analysis, with use of age as a covariate, showed a small but significant inverse relationship with changes in VO2 max. It was concluded that men of the 49-65 age group respond favorably to endurance exercise and show a magnitude of change similar to that found in previous investigations of similar design with younger subjects.

Age Factors↗
PubMed1976

Studies on the narcotic receptor in the guinea-pig ileum.

Studies were conducted on the development and loss of tolerance to morphine in the coaxially stimulated guinea-pig ileum. In ilea from guinea pigs made tolerant to morphine by the procedure of morphine-pellet implantation, the morphine-naloxone pA2 was decreased from 8.5 to 7.6, suggesting a qualitative rather than a quantitative change in the receptors. This change in the pA2 was in the opposite direction from that previously observed with analgesic receptors. Three hours after the administration of a single injection of morphine to the guinea pig, the ileum showed tolerance to morphine, which disappeared by 6 hours. With naloxone as the antagonist, the narcotic analgesics, morphine, methadone, etorphine and levorphanol, yielded higher pA2 values than the narcotic antagonist analgesics, nalorphine, pentazocine and cyclazocine, a result similar to that seen with the analgesic receptors. However, the interaction between naloxone and the narcotic antagonists in the ileum differed from that in the central nervous system when the slopes of the pAx plots were examined. Thus, although the interaction of analgesics with the ileal receptors appears to correlate with the acute effects of the drugs, caution must be exercised to use the ileal receptors as models of analgesic receptors for the study of chronic narcotic effects, i.e., tolerance and dependence.

Animals↗
PubMed1976

Effect of 6-hydroxydopamine and 5,6-dihydroxytryptamine on the response of the coaxially stimulated guinea-pig ileum to morphine.

Studies were conducted to determine the role of norepinephrine and 5-hydroxytryptamine in the action of morphine in the coaxially stimulated guinea-pig ileum. 6-hydroxydopamine produced supersensitivity to norepinephrine and decreased the levels of norepinephrine in the ileum. 6-Hydroxydopamine did not interfere with the acute effects of morphine but did interfere with the degree of tolerance developed to morphine, which is in contrast to reported results of the effect of 6-hydroxydopamine on the analgesic response to morphine. No evidence was found that 5,6-dihydroxytryptamine altered the acute or chronic response of the ileum to morphine. Again this is in contrast to results for the analgesic receptor where 5,6-dihydroxytryptamine has been reported to inhibit the development of tolerance to morphine. Thus, the role of the biogenic amines in the action of morphine in the ileum appears to differ from their reported role in the action of morphine in the central nervous system.

5,6-Dihydroxytryptamine↗