PubMed Health⌕ Search

Biomedical subjects

N O Olambiwonnu

Publications and source records attributed to N O Olambiwonnu.

14 recordsLinked to original sources
PubMed1977

Episodic fluctuations of serum gonadotropins in pre- and post-pubertal girls and boys.

The concentrations of LH and FSH were determined in serum samples obtained at 15 min intervals during a 4 h period from seven normal girls, 9.5-16.5 years of age, and eight normal boys, 9.0-16.8 years of age. An episodic pattern of LH secretion was found in all subjects. There was no significant (P greater than 0.1) difference between girls and boys as to number of episodes (3.0 +/- 0.6 vs. 3.0 +/- 0.0 per 4 h), absolute LH increase (2.6 +/- 1.1 vs. 2.4 +/- 1.0 mIU per ml) or "apparent LH half-life" (64.3 +/- 20.8 vs. 76.1 +/- 23.4 min). Mean absolute increase during secretory episodes correlated (R = 0.89, P less than 0.005) with the mean LH concentration per 4 h, and a significant (P less than 0.025) inverse correlation (R = -0.52) was found between the mean per cent increment of the LH secretory episode and the mean "apparent LH half-life." Minor fluctuations of FSH were also observed. In girls and boys, the mean concentration of both gonadotropins increased with advancing puberty. The increase in LH concentration was due to an increase in the amplitude of secretory episodes rather than to an increase in the number of episodes. The increase in FSH concentration reflected a consistent elevation throughout the period of sampling.

Adolescent↗
PubMed1977

Evolution of the menstrual pattern of gonadotrophin and sex steroid concentrations in serum.

Consecutive daily serum samples were obtained over 25-30 days from 2 pre-pubertal girls (Stage I), 2 girls with breast development alone (Stage II); one girl with both breast development and pubic hair (Stage III), and 2 girls who were six months and three years post-menarche, respectively (Stage IV). All serum samples were assayed for LH, FSH, progesterone and 17-hydroxyprogesterone. Sera from 6 girls were assayed for testosterone, and sera from 3 were assayed for oestradiol. The patterns of gonadotrophins and sex steroid concentrations in both Stage I and Stage II girls were characterized by day to day stability. LH and FSH concentration was increased in Stage II subjects, while steroid concentration were similar to those in Stage I. The Stage III subject showed marked, apparently random, fluctuations in the concentrations of LH, FSH, oestradiol and 17-hydroxyrogesterone. In Stage IV, as early as six months post-menarche, there was a definte peak in the serum concentration of gonadotrophins, 17-hydroxyprogesterone and oestradiol. However, luteal phase length and maximal progesterone levels of these post-menarchial girls were less than those observed for normal adult females. These data are consistent with evolution of the adult menstrual pattern of hormone secretion through a series of developmental stages.

Adolescent↗
PubMed1975

Sexual maturation in subjects with sickle cell anemia: studies of serum gonadotropin concentration, height, weight, and skeletal age.

Luteinizing hormone and FSH concentrations were determined in sera obtained from 20 males and 20 females, ages 5 to 16 years, with sickle cell anemia (homozygous hemoglobin S). Height, weight, bone age, and stage of sexual development were also determined. Gonadotropin concentrations were increased for stage of sexual development, suggesting transient impairment of gonadal function during the first decade of life. Increased impairment of growth during the second decade of life (18 of 26 subjects, 69%) as compared to the first decade (4 of 14 subjects, 29%) was consistent with prior deficiency of gonadal secretion of steroids. Mean bone age (11.2 +/- 2.1 year) determined in 15 subjects was significantly less than the mean chronologic age (13.0 +/- 1.8 year). Significant additional data, particularly those which would be derived from a longitudinal study, are needed to validate the preliminary hypothesis that transient impairment in gonadal function may, in part, account for the variation in sexual maturation seen in subjects with sickle cell anemia.

Adolescent↗
PubMedDate not supplied

Daily variations in urinary excretion of luteinizing hormone and follicle stimulating hormone in idiopathic isosexual precocity.

The 24-hour urinary excretion of luteinizing hormone (LH) and follicle stimulating hormone (FSH) was determined for 30 days in an 8.3-year-old girl with isosexual precocity and for 25 days in a normal 11.9-year-old girl. The pattern of daily variation in urinary LH and FSH excretion observed in the girl with sexual precocity was similar to that of the normal menstrual cycle. The LH and FSH midcycle peaks were 132.5 IU/24 hours and 26.3 IU/24 hours, respectively. Excluding the midcycle peak, the daily excretion of LH was 28.4 +/- 9.3 (SD) IU/24 hours, and the excretion of FSH was 8.9 +/- 1.9 (SD) IU/24 hours, values comparable to those of normal adult females. In contrast, the daily excretion of LH in the normal 11.9-year-old girl was 6.9 +/- 1.1 (SD) IU/24 hours and FSH excretion was 3.9 +/- 0.9 (SD) IU/24 hours. No LH or FSH surge was observed. The data are consistent with early maturation of the hypothalamic-pituitary-gonadal axis in idiopathic isosexual precocity.

Child↗