Rapid oscillation of circulating gonadotropins in postmenopausal women.

The circulating levels of of radioimmunoassayable LH and FSH in three postmenopausal women were measured in samples drawn at one minute intervals for a period of 150 or 300 min in order to ascertain the existance of short term oscillation on the plasma content of pituitary gonadotropins. Radioimmunoassay methods and sampling procedures fulfilled all the requirements of quality control. Rapid and non-coincident oscillation in the plasma levels of both LH and FSH at the interval studied were observed in all cases. Statistical analysis disclosed that in addition to short-term gonadotropin fluctuation, the data successfully fit in a 120 min periodic function and the graph resembled a sine wave that was also compatible with an ultradian oscillatory pattern.

Body composition in hypopituitary dwarfs before and during human growth hormone therapy.

The clinical characteristics and body composition of eight hypopituitary dwarfs (10.2-21.6 yr) were analyzed before and after 6 and 12 mo of growth hormone therapy. 2 IU 3 times/wk. Before treatment, growth rate was 1.8 +/- 0.7 cm/yr, height age was 2.0-12.8 yr less, and bone age 2.0-11.1 yr less than chronologic age. Total body water (TBW), lean body mass (LBM), extracellular water (ECW), and intracellular water (ICW) were below normal for chronologic age, but normal for height. Muscle mass (MM) was below normal for age and height. During HGH therapy, growth rate was 7.1 +/- 1.6 cm/yr in the first 6 mo and 7.8 +/- 1.4 cm/yr during the next 6 mo; the ratio of change in height age to change in chronologic age was greater than or equal to 1.0 in all patients and the ratio of change in bone age to change in height age was 1.2 in one patient and less than or equal to 1.0 in the others. TBW, LBM, ECW, and ICW increased according to height increments; however, MM increased at a faster rate than expected from the height gains. Also, a relative or absolute loss of total body fat was recorded during the first 6 mo of therapy. It is suggested (1) that among the body composition parameters studied, muscle mass is the tissue most closely reflecting the lack of HGH and also its therapeutic benefits and (2) evaluation of body composition in hypopituitary dwarfs in response to HGH therapy shows striking changes not reflected by the determination of stature or weight alone.

Kinship coefficients and genetic distance among 23 Mexican Indian tribes.

Genetic distances (d) and kinship coefficients (f) of 23 Mexican Indian groups were obtained, based on the results of ABO, Rh, MN, Duffy and Diego blood group systems and serum haptoglobins. The results obtained did not correlate well with linguistic classification or geographical location and we conclude that the method used is not sensitive enough to correctly separate relatively similar groups which have different degrees of external admixture (with blacks and caucasians) and internal admixture (among themselves).