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Biomedical subjects

Z Laron

Publications and source records attributed to Z Laron.

At least 307 records · Page 17Linked to original sources
PubMed1977

The LH and FSH responses to LH-releasing hormone (LH-RH) in girls with true precocious puberty treated with cyproterone acetate.

Ten girls with precocious puberty ranging in age from 7 to 10 7/12 years who were treated with oral cyproterone acetate on a long term basis, were subjected to LH-RH tests, prior to and 3 to 16 months after the institution of therapy. Cyproterone acetate was given in doses from 60 to 153 mg/m2, which proved to be clinically effective, as evidenced by the slowing down of sexual maturation. The basal levels of LH were found to be unaffected by therapy and corresponded to the pubertal stages of the individual girls. The peak increment of LH after LH-RH stimulation was markedly suppressed by the therapy. FSH secretion and its responsiveness to LH-RH was not affected by cyprotereone acetate. The basal levels of FSH were higher during therapy than before, but the peak FSH increment remained the same. An escape phenomenon in the LH peak response was evident in 2 patients upon retesting after prolonged therapy. It is possible that the antigonadotrophic action of cyproterone acetate is due to its progestational nature.

Child↗
PubMed1977

Hypothyroidism due to ectopy in siblings.

Two families each had two siblings with hypothyroidism due to ectopy and hypoplasia of the thyroid. A genetic factor controlling normal thyroid development and descent may be responsible, and the importance of plasma thyroid-stimulating hormone estimation in borderline hypothyroid cases is emphasized. We suggest screening of siblings of patients with ectopic thyroid for hypothyroidism.

Child, Preschool↗
PubMed1977

The effect of hGH deficiency on the insulin response to glucagon after oral glucose loading.

Six children and adolescents (aged from 2 6/12 to 16 years) with isolated hGH deficiency were subjected to a standard oral glucose tolerance test (OGTT) followed by the administration of IV glucagon at 180 mins. Three of them underwent a second test after several months of hGH therapy. Nine patients underwent a separate IV glucagon test and two of these patients had both tests. As controls served 14 endocrinologically normal children and adolescents, who underwent both tests. It was found that the patients with isolated hGH deficiency had lower basal insulin and blood glucose levels and that their insulin response to IV glucagon even after oral glucose preloading was significantly lower than in the control group. This response was partially restored by several months of hGH treatment in the three patients tested. These findings are interpreted as further evidence for an insulinotrophic effect of hGH.

Adolescent↗
PubMed1977

The purification and characterization of a lipolytic factor from bovine pituitaries.

During the purification of a bovine growth hormone preparation (S408A) a yet unknown lipolytic peptide as obtained. This substance was subjected to CM cellulose chromatography followed by differential precipitation with trichloracetic acid. The resulting purified peptide was homogenous on disk electrophoresis and consisted of 36 amino acids with a molecular weight of 4.000. The lipolytic activity was found to be very high and 20-fold that of the starting material, Protein recovery was 1.8%. This peptide, called bovine pituitary lipolytic factor (BLF) was active in rat adipose tissue, exhibiting a minimal effective dose (MED) of 0.05 x 10(-9) mMol/ml. An immunological cross reaction was found between BLF and anti luteinizing hormone beta chain. This can denote that BLF and LH beta chain share similar or identical immunological determinants. The possibility is raised that LH beta chain is precursor of BLF.

Adipose Tissue↗
PubMed1977

Penile size and growth in children and adolescents with isolated gonadotrophin defiency (IGnD).

Penile length and circumference were measured in twenty boys with isolated gonadotrophin deficiency, before and during the administration of androgen therapy. Their age ranged between 3 and 20 years. Considering as normal, measurements above the tenth centile, in all the patients but four the penile length was below normal, and in two it was borderline. Penis circumference was normal in two, borderline in four and subnormal in sixteen. Regular administration of androgen therapy increased penile length in eleven out of fourteen patients with achievement of normal length in four. It is concluded that congenital lack of LH and testicular androgen activation causes small sized penises, even in the prepubertal period. Gonadotrophin deficiency should be looked for in patients with measurements below the tenth centile. Early diagnosis and institution of androgen therapy between 11 and 12 years is likely to increase penile size and prevent the psychological side effects of undersized genitals and delayed puberty.

Adolescent↗
PubMed1977

The combined effect of growth hormone and methandrostenolone on the linear growth of patients with multiple pituitary hormone deficiencies.

Six patients with multiple pituitary hormone deficiencies (MPHD) were initially treated with separate courses of methandrostenolone and growth hormone and later with the two drugs combined. During the basal period the mean growth velocity was 2.8 cm/year. Methandrostenolone alone, 0.02-0.05 mg/kg/day given to four of the patients led to an acceleration of the growth velocity to a mean of 5.0 cm/year, while growth hormone 6 mg/week alone accelerated the growth rate to a mean of 6.0 cm/year. Combined therapy led to a striking increase in the mean growth rate to 9.3 cm/year. The shortcoming of the combined growth hormone-androgen therapy was the fast acceleration in skeletal maturation even after short-term administration.

Adolescent↗
PubMed1977

Gonadal function in Bloom's syndrome.

Five patients with Bloom's syndrome aged from 2 8/12 to 27 years, all of whom had hypogonadism, were subjected to an i.v. LHRH test and two of them to an i.m. HCG test. There was increased responsiveness of plasma LH and FSH, indicating that the hypogonadism is primary in nature and of early development. The tubular element of the testis seems to be mainly affected, as indicated by the particularly high FSH response to LHRH stimulation, a history of sterility in the two adult patients and documented azoospermia in one of them. The Leydig cells seem to be less affected and secrete sufficient androgens to enable puberty within acceptable normal limits. Hypogonadism seems to be a major characteristic of Bloom's syndrome.

Abnormalities, Multiple↗
PubMed1977

Prolactin secretion in girls with isolated gonadotrophin deficiency.

Plasma prolactin, basal levels and the response to an i.v. injection of TRH (100 microgram/m2) was determined in five girls with isolated gonadotrophin deficiency of hypothalamic origin before and after at least 3 months cyclic replacement therapy with conjugated oestrogens (1.25 mg/day). The basal plasma prolactin levels were similar during both tests, however, during oestrogen therapy the mean peak response to TRH almost doubled and the sum of all the values obtained (basal, +15, +30 and +60 min) was significantly higher. It is of note that even upon prolonged oestrogen deprivation the releasable prolactin response to TRH was adequate.

Adolescent↗
PubMed1977

Plasma LH and FSH response to LRH and plasma testosterone levels in boys with irregular puberty.

Nineteen boys with irregular puberty (IP), defined as a discrepancy of two or more pubertal stages between the criteria for genitalia and that for pubic hair, were subjected to a standard LRH test (50 microng/m2, iv) and the response of gonadotrophins as well as the basal levels of plasma testosterone, LH and FSH were compared to those of boys with normal, regular puberty. When the results were plotted against the pubertal stage for genitalia (Pg), it was found that in the boys with IP the basal plasma testosterone levels were lower and the response of plasma LH to LRH stimulation lesser than in the controls. However, when these parameters were plotted against the pubertal stage for pubic hair (Ph) it was found, that in the boys with IP the plasma testosterone levels were significantly higher and the response of both LH and FSH stimulation greater than in the control group. It was concluded that irregular puberty in boys may be regarded as a normal variation. The delayed development of sexual hair and penile length, and retarded pubertal growth spurt and bone age maturation seen in these boys, with normal testicular development, may be explained by a temporary reduced peripheral sensitivity to androgens and a compensatory effort by the pituitary, manifested in increased secretion of LH and testosterone, relatively to their pubertal stage for pubic hair.

Adolescent↗
PubMed1977

Relationship between food intake and insulin response to oral glucose tolerance test in short lean children.

Based on diet questionnaires and food intake analysis, a study was made of the eating habits of 35 lean children and adolescents with constitutional familial short stature. The children were divided into four groups according to their plasma insulin response to an oral glucose tolerance test (normal or low) and to the season during which the test was given. No statistically significant differences in caloric intake were found. The overall total caloric intake in all groups was 166 to 190% of the recommended dietary allowances set by the U.S. National Academy of Sciences. It is concluded that the insulin response to the oral glucose tolerance test is not related to caloric intake.

Adolescent↗
PubMed1977

Bloom's syndrome. VI. The disorder in Israel and an estimation of the gene frequency in the Ashkenazim.

An effort was made to identify all individuals with Bloom's syndrome living in Israel between September 1971 and September 1972. Each of the eight individuals located were Jewish and could readily be classified Ashkenazic. The frequency of the Bloom's syndrome gene in Ashkenazim was estimated to be .0042 (minimum), implying a heterozygote frequency greater than 1 in 120. A striking distortion of the sex ratio (M/F = 7.0) may have been due to underascertainment of affected females. One of the affected individuals ascertained during the survey subsequently has died from cancer, which is in keeping with the recognized cancer proneness of this condition. Four of the affected have married, but no conception is known to have occurred, which suggests that sub- or infertility is a feature of the syndrome.

Adult↗