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V V Weldon

Publications and source records attributed to V V Weldon.

35 records · Page 2Linked to original sources
PubMed1975

Evaluation of growth hormone release in children using arginine and L-dopa in combination.

L-Dopa in a dose ranging from 125-500 mg and arginine monochloride in a dose of 0.5 gm/kg were given simultaneously to 56 children with short stature (height less than third percentile). Sixteen of these children were subsequently diagnosed as having growth hormone deficiency. The diagnosis of hyposomatotropism was based on clinical findings and on responses to the combination test and to arginine and L-dopa administered as separate tests. All of the remaining 40 children had a normal GH response of greater than 6 ng/ml to the combination test. However, in this group, nine children were identified who responded to the combination test but who failed to respond to arginine and L-dopa in individual tests. The data suggest that a positive response to arginine and L-dopa in combination in children, who do not respond to the usual provocative tests when administered individually, may fail to identify children with partial GH deficiency who would benefit from treatment. The integrated stimulated GH response in the 31 children in whom a normal GH response to all three tests occurred suggests that the effects of L-dopa and arginine are additive.

Adolescent↗
PubMed1975

Radioreceptor-inactive growth hormone associated with stimulated secretion in normal subjects.

We have previously reported systematic discrepancies between radioreceptor (RRA) and radioimmunoassay (RIA) measurements of growth hormone (hGH) in acromegalic patients. Due to limitations in RRA sensitivity, such comparisons could not be made in normal subjects. RRA methodology has now been adapted to allow detection of hGH at normal circulating levels. Since variations in Na+, K+, Ca++, and Mg++, incubation at 37 C and 4 C, and delayed tracer addition failed to improve assay sensitivity, specimen size was increased to 300 mul and incubation volume to 1.5 ml, while holding the quantity of added receptor constant. Best assay sensitivity, in room temperature incubations in 25 mM Tris for 16 h at pH 7.6 and 10 mM Ca++, was 0.66 +/- 0.30 ng hGH per ml serum. Under these conditions, 200 mug hepatic receptor protein bount 15.8 +/- 0.83% of added 125I-hGH, and 8.72 +/- 0.85% of bound tracer was displaced by 0.25 ng added unlabeled hGH. Nonspecific depression of binding by serum did not impair assay sensitivity with most receptor preparations. The basal hGH measured by RIA (antiserum 68-416) in a group of normal short children was 1.97 ng/ml, similar to the RRA result, 1.89 ng/ml (P = NS). Comparative measurements were also made in selected samples of sufficient volume during the 1 1/2 h following administration of hGH secretagogues (insulin, arginine, L-dopa). In these samples, the RIA value was 9.34 +/- 0.68 and the RRA value 6.29 +/- 0.62 ng/ml (P less than 0.01); the RIA/RRA was 1.77 +/- 0.18. Thus, no significant measurement discrepancy was found in basal samples from normal subjects, in contrast to previous findings in acromegalics. The appearance of such a discrepancy within 90 min after stimulation of hGH might be due to RIA/RRA discordance in secreted molecular subspecies, or might arise from peripheral hGH metabolism.

Acromegaly↗
PubMed1970

Transplacental passage and fetal secretion of aldosterone.

The transplacental passage and the production of aldosterone were studied in late pregnancy during a constant infusion of 1,2-aldosterone-(3)H to mothers at the time of elective cesarean section. It was found that, while maternal aldosterone crossed the placenta, there was a significant secretion of aldosterone by the fetus. The aldosterone concentration in fetal plasma was 2-12 times higher than that of the corresponding mothers. Pregnancy had no effect on the metabolic clearance rate of aldosterone, but it increased the rate of production of this steroid. However, the increments that we observed were smaller than those reported in previous reports. The discrepancy was probably due to differences in body posture, our subjects being supine for at least 10 hr at the time of study.

Adolescent↗
PubMedDate not supplied

Glycemic control and bone age are independently associated with muscle capillary basement membrane width in diabetic children after puberty.

This study was undertaken to examine the possible relationships between muscle capillary basement membrane width (CBMW) and glycemic control, bone age, chronologic age, and duration of diabetes in young patients with insulin-dependent diabetes mellitus (IDDM) during different stages of pubertal development. We studied 49 males and 43 females (age, 7-20 yr) with IDDM for up to 16 yr for whom bone age and glycosylated hemoglobin (HbA1c) data were available at the time of right quadriceps muscle biopsy. Based on pubic hair Tanner stage, subjects were assigned to prepubertal (Tanner I), pubertal (Tanner II and III), and postpubertal (Tanner IV and V) groups. In 30 pubertal and prepubertal subjects, none of the variables studied was significantly correlated with CBMW. This is attributable in part to the small number of subjects in each group. In 62 postpubertal subjects, CBMW was correlated with age (r = .27, P = .03), bone age (r = .43, P = .0005), and postpubertal duration of diabetes (r = .38, P = .003) but not total duration of diabetes. In the postpubertal subjects, CBMW was correlated with HbA1c at the time of biopsy (r = .31, P = .01) but correlated more strongly with the mean of HbA1c values obtained during the 1- and 2-yr periods before biopsy (r = .37, P = .01, and r = .54, P = .03, respectively). An analysis of covariance revealed that the slopes for the regression of loge CBMW on HbA1c differed significantly (P = .02) among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗