We undertook a study of the separate and combined effects of age and sex on the pulsatile pattern of GH secretion. The 24-h secretory profile of GH was generated by 20-min sampling in 10 young women (aged 18-33 yr), 10 young men (aged 18-33 yr), 8 postmenopausal women (aged greater than 55 yr), and 8 older men (aged greater than 55 yr). A computer-assisted pulse analysis program was used to assess both total GH secretion, as reflected in the 24-h integrated GH concentration (IGHC), and pulsatile secretion, as denoted by pulse frequency, duration, amplitude, and the fraction of GH secreted in pulses during the 24-h period (FGHP). IGHC was significantly greater in women than in men (P less than 0.025) and greater in the young than in the old (P less than 0.003). The mean pulse amplitude, duration, and FGHP were each greater in the young (P less than 0.006, P less than 0.03, and P less than 0.0001, respectively), but not significantly different between the sexes. The mean pulse frequency was not affected by sex or age. The serum concentration of free estradiol, but not free testosterone, correlated with IGHC (r = 0.46; P less than 0.005), pulse amplitude (r = 0.53; P less than 0.001), and FGHP (r = 0.59; P less than 0.0002). After correcting for the effects of estradiol, neither sex nor age influenced IGHC or mean pulse amplitude, while the effect of age on FGHP was reduced from 81% to 29%. Of the indices of GH secretion, FGHP had the strongest correlation (r = 0.43; P less than 0.006) with somatomedin-C. Somatomedin-C declined significantly with age in both sexes. Our results indicate that sex and age have independent and interrelated effects on GH secretion. These effects can be largely accounted for by corresponding variations in endogenous estradiol levels. These observations suggest an amplifying action of estradiol on the neuroendocrine regulation of pulsatile GH release.

No abstract

No abstract

While keeping in mind appropriate caveats in extrapolating from these data, the prevalence rate of asymptomatic unruptured aneurysms found in the present study allows an estimation of the yearly rate of rupture of these lesions. The authors suggest that this yearly rate of rupture falls within the range of 1 to 2%.

No abstract

The ability of predischarge quantitative exercise thallium-201 (201T1) scintigraphy to predict future cardiac events was evaluated prospectively in 140 consecutive patients with uncomplicated acute myocardial infarction; the results were compared with those of submaximal exercise treadmill testing and coronary angiography. High risk was assigned if scintigraphy detected 201Tl defects in more than one discrete vascular region, redistribution, or increased lung uptake, if exercise testing caused ST segment depression 3 1 mm or angina or if angiography revealed multivessel disease. Low risk was designated if scintigraphy detected a single-region defect, no redistribution, or no increase in lung uptake, if exercise testing caused no ST segment depression or angina, or if angiography revealed single-vessel disease or no disease. By 15 + 12 months, 50 patients had experienced a cardiac event; seven died (five suddenly), nine suffered recurrent myocardial infarction, and 34 developed severe class III or IV angina pectoris. Compared with that of patients at low risk, the cumulative probability of a cardiac event was greater in high-risk patients identified by scintigraphy (p < .001), exercise testing (p = .01 1), or angiography (p = .007). Scintigraphy predicted low-risk status better than exercise testing (p = .01) or angiography (p = .05). Each predicted mortality with equal accuracy. However, scintigraphy was more sensitive in detecting patients who experienced reinfarction or who developed class III or IV angina. When all 50 patients with events were combined, scintigraphy identified 47 highrisk patients (94%), whereas exercise-induced ST segment depression or angina detected only 28 (56%) (p < .001). The presence of multivessel disease as assessed by angiography identified nine more patients with events than exercise testing (p = .06). However, the overall sensitivity of angiography was lower than that of scintigraphy (71% vs 94%; p < .01) because three patients who experienced reinfarction and 10 who developed class III or IV angina had single-vessel disease. Importantly, 12 (92%) of these 13 patients with single-vessel disease who had an event exhibited redistribution on scintigraphy. These results indicate that (1) submaximal exercise 201TI scintigraphy can distinguish high-and low-risk groups after uncomplicated acute myocardial infarction before hospital discharge; (2) 201TI defects in more than one discrete vascular region, presence of delayed redistribution, or increased lung thallium uptake are more sensitive predictors of subsequent cardiac events than ST segment depression, angina, or extent of angiographic disease; and (3)

Cutaneous malignant melanomas of the head and neck are prognostically engimatic. In addition to known prognostic determinants of stage and lesion microstage, lesion location also appears to have prognostic importance. The authors have reviewed a series of 83 microstaged head and neck melanoma patients in order to analyze the relative importance of these factors. There were 36 males and 47 females with a median age of 56 years. Eighty-one percent had pathologic Stage I disease, 7% were Stage II, and 12% were Stage III. The primary location was face in 32 patients, neck in 18, ear in 12, and scalp in 21 patients. The actuarial 5-year survival according to lesion thickness was 86% for melanoma less than 1.0 mm, 56% for 1 to 2 mm thick lesions, 47% for 2.1 to 4 mm thick lesions, and 25% for melanomas greater than 4.0 mm. The 5-year survival according to lesion location was 78% for facial and 58% for neck melanomas; for ear and scalp, the respective survivals were 33% and 37%. Median thickness was 2.0 mm for facial and 1.85 mm for neck lesions. It was 2.7 mm for ear and 2.0 mm for scalp lesions (differences not significant). There were no microstage factors that correlated with the adverse prognosis seen with scalp and ear melanomas. Multivariate analysis in the entire series (all clinical stages) showed the following to be significant: stage, thickness, and location of the primary melanoma (all less than 0.0002). In clinical Stage I melanoma, the significant prognostic factors were location (P = 0.035), thickness (P = 0.008), level (P = 0.024), and ulceration (P = 0.035). The prognosis of head and neck melanoma is uniquely influenced by location of the primary lesions in addition to stage, thickness, level, and ulceration, as observed with other cutaneous melanomas at other sites. Ear and scalp melanomas are high-risk lesions whose poor prognosis is not readily explained by any of the microstage factors reviewed.

No abstract