Search PubMed⌕ Search

Biomedical subjects

Z Laron

Publications and source records attributed to Z Laron.

At least 271 records · Page 15Linked to original sources
PubMed1980

Age at first conscious ejaculation: a milestone in male puberty.

The age of occurrence of the first conscious ejaculation was registered in 263 boys belonging to two categories: (1) 128 boys (70 normal controls, 22 boys with unilateral cryptorchidism with normal puberty, and 36 boys with delayed puberty) who had been under regular follow-up throughout puberty. All underwent a complete physical examination at intervals of 3 to 6 months, and in most a wrist X-ray was made within three months of the first ejaculation. (2) A group of 135 boys examined and questioned at their school served as additional controls. Eighty of these reported ejaculations. Despite a wide range in the chronological age at occurrence of the first conscious ejaculation, the mean bone age in all groups, including that with delayed puberty, was 13 1/2 +/- 1/2 years (SD), with a range between 12 1/2-15 1/2 years. There was no correlation between the age at first ejaculation and testicular volume, pubic hair or penis length. It is proposed that the age at the first conscious ejaculation be used as an index of maturation in male puberty.

Adolescent↗
PubMed1980

Growth hormone resistance.

Biological ineffectiveness of endogenous or exogenous growth hormone (GH) (i.e. a state or resistance) has been reported in several clinical conditions. The most typical form is Laron-type dwarfism, a hereditary disease which is clinically undistinguishable from isolated GH deficiency and which is characterized by high levels of plasma hGH but low somatomedin (SM). It is shown that the GH molecule binds normally to human liver receptors proving its normalcy. Thus the disease is due to an inability to generate active SM. States of resistance to exogenous GH by receptor occupancy exist when endogenous hormone is secreted in large amounts (newborns, acromegaly) or even normal amounts. Endorgan resistance to SM and GH such as in Pygmies represent an additional type. GH resistance is also induced by a rise in antibodies to GH by use of an impure or altered preparation or in a rare form of lack of immunotolerance to hGH, or by an enhancement of SM inhibitors as is seen in chronic renal failure or corticosteroid overdosage.

Dwarfism↗
PubMed1980

Pubertal development in girls with sexual precocity after discontinuation of treatment with cyproterone acetate.

Twenty-four girls with sexual precocity who had been treated with cyproterone acetate were followed for periods from 1 to 8 1/2 years after the discontinuation of therapy. It was found that their further pubertal development and the resumption or appearance of menstruation followed a natural course within the wide limits of physiological variability. It is concluded that puberty resumes its natural course following cessation of treatment with cyproterone acetate, and it is assumed that the reproductive ability of these patients will not be affected.

Adolescent↗
PubMed1979

Oral clonidine as a growth hormone stimulation test.

A single oral dose of 0.15 mg/m2 of clonidine was given to eighteen healthy children and adolescents and to seven patients with hypopituitarism. In healthy subjects there was a pronounced increase in plasma growth hormone from 4.9 +/- 1.3 ng/ml (+/- SEM) to 34.4 +/- 4.5 ng/ml. In the patients with hypopituitarism there was no change in growth-hormone concentrations. Clonidine induced a slight increase in blood glucose in healthy subjects and a slight decrease in patients with hypopituitarism. During the test systolic blood-pressure decreased by a mean of 20 mm Hg in the healthy subjects and by 25 mm Hg in the patients with hypopituitarism. The only side-effect observed was drowsiness. Oral administration of clonidine, a well-tolerated drug, seems to be a simple test for of GH reserves in children and adolescents.

Administration, Oral↗
PubMed1979

Growth factors.

Explore the source record for details and available documents.

Animals↗
PubMed1979

Effect of human growth hormone therapy on head circumference in children with hypopituitarism.

Head circumference was measured before and during hGH therapy in fourteen children with isolated growth hormone deficiency (IGHD) and in twenty-one children with multiple pituitary hormone deficiencies (MPHD). In both groups there was a retardation in growth of the neurocranium, more marked in the children with IGHD, which was less than the retardation in linear height. In the group with IGHD, initiation of hGH therapy before a chronological age of 5 and a bone age of 3 had been reached led to a rapid catch-up in cranial growth with normalization of the head size. In older children the induction of head growth was similar to that achieved by the long bones but without a true catch-up phenomenon. In three adults with hereditary IGHD without therapy or with irregular treatment during late puberty, the head circumference was below normal range. In view of the possible role played by development of brain tissue upon cranial size, the importance of early diagnosis and initiation of therapy in infants and young children with a deficiency of hGH is stressed.

Adolescent↗
PubMed1979

XY gonadal dysgenesis associated with hGH and gonadotrophin deficiencies.

A girl of remarkably short stature, referred for investigation with the diagnosis of gonadal dysgenesis and the finding of a male karyotype, proved to be deficient in growth hormone and gonadotrophin secretion, and was treated with growth and sex hormones. It was concluded that this case demonstrates an apparently casual coincidence of pituitary insufficiency with XY gonadal dysgenesis, evidently the first to be reported.

Adolescent↗
PubMed1979

Multiple pituitary hormone deficiencies in eight siblings of one Jewish Moroccan family.

In a Jewish Moroccan inbred family, 8 of 12 siblings were found to have multiple deficiencies of pituitary hormones, including GH, TSH and gonadotrophins. The parents showed no deficiency and are in good health, as are the other 4 siblings. The investigations carried out indicate that in this family the etiology is hereditary in nature, probably being autosomal recessive, with the defect located in the pituitary gland.

Adolescent↗
PubMed1979

Linear growth in hypopituitary patients treated with hGH after age fifteen.

Two groups of hHG deficient adolescents (isolated growth hormone deficiency: 11 patients and multiple pituitary hormone deficiency: 20 patients) receiving hGH therapy were analyzed for their linear growth response. It was found that even at a chronological age of 15 years or more, growth can be markedly enhanced, depending upon the bone age and pubertal stage in the IGHD patients and upon optimal balance between hGH and sex hormones in the MPHD patients.

Adolescent↗
PubMed1979

Hepatomegaly due to self-induced hyperinsulinism.

Repeated hypoglycaemic attacks, associated with transient hepatomegaly, in a 12-year-old insulin-dependent diabetic girl continued despite reduction in dose and, later, complete discontinuance of insulin. The attacks ceased while she was in hospital, necessitating reinstitution of insulin. The hepatomegaly resolved when surreptitious additional insulin injections were discovered and stopped. Hepatomegaly in diabetics should arouse suspicion of overdosage with insulin.

Child↗
PubMed1979

Effect of triiodothyronine administration on the plasma TSH and prolactin responses to TRH in patients with hypothalamic-pituitary insufficiency.

A study was carried out in 10 patients with multiple pituitary hormone deficiencies to determine the response of thyroid-stimulating hormone (TSH) and prolactin (PRL) to thyrotropin-releasing hormone (TRH) and their suppressibility by treatment with triiodothyronine (T3) given at a dose of 60 microgram/day for 1 week. In 3 patients the basal tsh values were normal and in 7 patients, 2 of whom had not received regular thyroid replacement therapy, they were elevated. The response of TSH to TRH was normal in 6 patients and exaggerated in 4 (of these, 1 patient had not received previous substitution therapy and 2 had received only irregular treatment). The basal and stimulated levels of TSH were markedly suppressed by the treatment with T3. The basal PRL levels were normal in 7 and slightly elevated in 3 patients. The response of PRL to TRH stimulation was exaggerated in 2, normal in 6 and absent in 2 patients. The basal PRL levels were not suppressible by T3 treatment but in 4 patients this treatment reduced the PRL response to TRH stimulation. From these findings the following conclusions are drawn: (1) T3 suppresses TSH at the pituitary level, and (2) the hyperreactivity of TSH to TRH and the low set point of suppressibility are probably due to a lack of TRH in the type of patients studied.

Adolescent↗
PubMed1979

The plasma FSH and LH response to synthetic LH-RH in normal pre-pubertal and early pubertal girls--a re-evaluation.

A standard LH-RH test (50 microgram/m2) given iv was carried out in 65 normal girls, 42 of them pre-pubertal aged from 4 7/12 to 11 years and 23 in the early stage of puberty, aged from 9 to 12 9/12 years. The results indicate that in pre-pubertal girls the basal levels of the plasma gonadotrophins remain steady (LH 0.6 +/- 0.1 mIU/ml; FSH 0.8 +/- 0.1 mIU/ml, m +/- SD) and that there is a small but significant response of LH to LH-RH (1.6 +/- 0.2 mIU/ml). During this period the FSH response to LH-RH is very marked (8.0 +/- 1.0 mIU/ml) with a gradual, significant decrease seen towards the onset of puberty (6.5 +/- 0.9 mIU/ml, P less than 0.001). These results support earlier reports that the LH-RH test is a useful tool to evaluate the secretion of pituitary LH and FSH in early childhood.

Adolescent↗
PubMed1979

Successful treatment of Cushing's disease with o,p'-DDD followed by pituitary irradiation in a 19-year-old male patient.

A 19-year-old male patient with Cushing's disease was treated for 15 months with a gastric-insoluble preparation of o,p'-DDD. The daily o,p'-DDD dose (range, 2 to 12 g) was adjusted periodically according to the urinary excretion of 11-hydroxycorticosteroids. Because of a rise in the plasma ACTH level from 135 to 300 pg/ml 12 months after the start of the o,p'-DDD therapy, the dose was reduced from 6 to 2 g/day and external pituitary irradiation (4,480 rads) was initiated. Insulin-induced hypoglycemia and stimulation tests with luteinizing-hormone-releasing factor and thyrotropin-releasing hormone, performed before initiation of o,p'-DDD and six months after pituitary irradiation, did not reveal any disturbance in the secretion of human growth hormone, thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone or prolactin. The clinical and laboratory signs of Cushing's disease disappeared gradually, and the patient tolerated the drug well, even at a dose of 12 g/day. The only abnormalities found during o,p'-DDD treatment were low serum thyroxine levels, which returned to normal after discontinuation of the drug, and a transient drop in thrombocyte count. At present, two years after the discontinuation of o,p'-DDD therapy and pituitary irradiation, the patient is symptom free and receives no medication.

Adult↗
PubMed1979

Growth pattern of boys with isolated gonadotropin deficiency.

The linear growth and skeletal maturation of 19 boys with isolated gonadotropin deficiency, including four with anosmia (Kallmann's syndrome), are presented. With the exception of one prepubertal-age boy (less than or equal to 10 years) and five pubertal-age boys (greater than 10 years), all heights were within normal limits, but below the 50th percentile. With one exception, the bone age was retarded in all boys, even in prepuberty.

Body Height↗