Biomedical subjects
Publications and source records attributed to P C Sizonenko.
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The incidence of congenital adrenal hyperplasia (CAH) in Switzerland was calucated for patients born in 1960 to 1974. Information was obtained by means of questionnaires sent to all Pediatric Hospitals and Institutes of Pathology in Switzerland. The number of patients and the incidences of the different enzyme defects were: all cases 110 (1:13785 livebirths), 21-hydroxylase 98 (1:15472), 11 beta-hydroxylase 5 (1:303260), 3 beta-dehydrogenase 3 (1:505433). The incidence of females--which is 1:12098 for all cases and 1:13924 for 21-hydroxylase deficiency--presumably appropximates more exactly the real incidence, because of incomplete diagnosis in the male. Salt loss was observed in two thirds of patients with 21-hydroxylase deficiency. A more reliable estimate of the incidence of CAH could be obtained by neonatal screening programs with measurement of serum-17-hydroxyprogesterone.
One hundred and four children aged 0-15 years, with suspicion of malabsorption were studied. They had a proximal jejunal biopsy and, at the same time, the following measurements: 25-hydroxycholecalciferol (25-OH-CC), calcium, phosphorus and serum alkaline phosphatase, bone age on X-ray of the left hand and wrist, cortical thickness of the 2nd, 3rd, 4th metacarpal bones. For the analysis of the results, the patients were divided into two groups according to the season (winter vs. summer). None of the patients in either group had clinical or radiological signs of rickets. The following results were obtained: 1. The 25-OH-CC serum levels were significantly lower during the winter than during the summer months. This was observed more frequently in the cases with atrophy of the jejunal mucosa. 2. During the summer, the 25-OH-CC serum levels were not different in the cases with normal or pathological mucosa. This demonstrates the importance of the skin synthesis of vitamin D during the summer months. 3. The mean of the serum calcium levels was significantly lower in the group of children with atrophy of the jejunal mucosa than in children with normal intestinal biopsy. The serum calcium levels were not correlated with the serum 25-OH-CC levels. 4. The serum phosphorus levels were significantly lowered during the winter months in the children aged 0-3 years with pathological jejunal biopsy. 5. The serum alkaline phosphatase levels were lowered in cases of total atrophy of the jejunal epithelium cells. 6. Cortical thickness of the metacarpal bones becomes thinner with the progression of the alteration of the jejunal epithelium cells, independently of season or age. However, only the group of children aged 0-3 years studied during the winter months and with total atrophy of the jejunal mucosa have a significantly diminished cortical thickness of the metacarpal bones. The lowering of the calcium levels and the decrease of the cortical thickness are probably secondary to an impaired intestinal absorption of calcium. In the syndrome of malabsorption, the integrity of the jejunal epithelial cells seems to play a more important role than a vitamin D deficiency in the genesis of this calcium malabsorption.
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Explore the source record for details and available documents.
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Hormonal changes during puberty have been well described: rise of gonadotropins followed by the rise of gonadal secretions at ages 10 to 16 years. The most striking new data are in fact concerning events that occur before puberty, first during the first months of life, second at age 7 years. The first event consists of a rise of gonadal steroids, which gives a hormonal impring that might be important for the future of the child. The second event concerns the prepubertal maturation of the androgenic zone of the adrenal cortex and the increasing secretion with age of the adrenal androgens. The mechanism of onset of both events is poorly explained. What causes the rise of gonadal steroids during infancy is unknown. Which pituitary factor, in addition to ACTH, stimulates the corticoadrenal androgenic zone, and which mechanism regulates its secretion remain unknown.
Based on the knowledge of the physiology of regulation of gonadotropins and gonadal steroids, basal levels of these hormones might be indicative of the etiologic factors of abnormal pubertal development. In addition, stimulatory tests may help in the diagnosis of such conditions. It is interesting that the pubertal maturation of the adrenal cortex is independent of the hypothalamic-pituitary-gonadal axis. The role of the adrenal cortex for the pubertal development remains questionable: adrenal androgens are low in isosexual precocious puberty, low in delayed adolescence, and normal in hyper- or hypogonadotropic hypogonadism. The importance of this role is doubled in congenital virilizing adrenal hyperplasia. When the disease is untreated, although adrenal androgens in excess advance bone age and hypothalamic maturation, girls remain prepubertal. When the therapeutic control is good, normal puberty occurs. The action of the adrenal androgens on growth and puberty remains to be determined.
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A new topical corticosteroid: fluocortin-butylester, was employed in 11 eczematous children (atopic and seborrhoeic dermatitis), with a good clinical result. These topical applications involve no significant risk of interference with the pituitary-adrenal function.
Many endocrinological factors control cellular growth of different tissues (cell multiplication and cell volume) and skeletal growth. The role of neuro-transmitters and of hypothalamic releasing and inhibiting factors of growth hormone secretion will be reviewed. The importance of the somatomedins on cartilage growth will be stressed. Thyroid hormones, androgens, and oestrogens have important stimulating actions on skeletal growth and maturation. Conversely, glucocorticoids have an important inhibitory effect on growth. The precise roles of these hormone factors in the regulation of growth hormone secretion, somatomedin production and tissue growth, particularly the cartilage, remain to be completely elucidated.
A LHRH-like substance is detectable in the urine. It is extractable by glass powder, which suggests that it is a peptide, and it can be concentrated by anti-LHRH affinity chromatography, strongly suggesting that it is not a contaminant in the RIA. It is composed of very little intact LHRH, and the great majority appears as multiple smaller fractions, although the possibility of "urinary LHRH" being a slightly larger peptide containing a sequence similar or identical to that of LHRH has not been entirely eliminated. Urinary measurements show no correlation with the clinical state, and the widely differing values obtained using different antisera in the present study emphasize the need for in-depth antiserum binding studies prior to clinical use in the LHRH radioimmunoassay.
The plasma levels of 25-hydroxyvitamin D (25-OHD), total calcium, phosphorus and proteins were measured in 40 healthy mothers and their infants at the time of delivery during the months of December and January. Calcium, phosphorus and proteins were again measured in the plasma of the infants on the fourth day of life. Vitamin D intake of the mothers during their last 3 months of pregnancy were estimated by interviews. The mean (+/-SE) plasma levels of 25-OHD was 9.0 +/- 0.9 ng/ml in the mothers and 5.05 +/- 0.4 ng/ml in cords. There was a significant correlation between mother and cord plasma levels (r = 0.75, p less than or equal to 0.001). The concentration gradient of 25-OHD plasma levels between mother and cord is higher at high 25-OHD maternal concentrations. This suggests that the placenta plays a regulating role in the 25-OHD transfer between mother and foetus. The 4-day-old infants from mothers having a suboptimal vitamin D intake (less than 150 IU/day) have a lower mean serum plasma level than infants born from mothers with a vitamin D intake of more than 500 IU/day.
Fourteen cases of primary congenital hypothyroidism were studied and separated for the analysis purpose into two groups. Group A consisted of 7 children whose hypothyroidism was diagnosed after 1971 and the therapy by thyroid gland extracts evaluated by regular serum thyroid hormone determinations. Group B was made of 7 children whose disease was diagnosed and treated before 1971. Two periods were therefore studied in group B: first period, before any hormonal determinations (as a growth control period for group A), and second period, during which hormonal determinations were made and taken into consideration for the dosage. Although growth patterns were similar in both groups, mean thyroid extracts dose was 63 +/- 25 mg/m2/day (mean +/- SD) during follow-up with hormonal determinations, while it was markedly higher during the first period of group B (125 +/- 76, range 46.1 to 219.9 mg/m2/day). The mean dose of 63 +/- 25 mg/m2 induces a mean level of plasma thyroxine of 82 +/- 32 microgram/1 (mean +/- 1SD), a normal growth (with catch-up growth in the patients who had a retarded growth), and a good psychomotor development. Regular measurements of serum thyroxine during therapy seems to be a valid parameter for determining the dose of thyroid gland extracts necessary for adequate substitution. Serum=1-triiodo-thyronine levels have more fluctuations than thyroxine. Serum TSH mainly prevents the underdose of patients but cannot help in case of overdose. The suggested dose for treatment of such patients is 88 mg/m2/day (= 63 + 1SD).
Plasma concentrations of adrenal androgens (DHEA and DHEA-S) and the growth patterns of four male patients with hypogonadotropic hypogonadism have been compared and contrasted with those of eight male patients wit idiopathic delayed puberty. As a group the patients with HH presented at an older age with delayed puberty and normal heights; the growth rate and pattern have been normal except for an absence of the pubertal growth spurt. Adrenal androgens were usually normal for chronologic age and high for bone age. The patients with IDP presented at a younger age, usually with short stature, low adrenal androgens relative to the chronologic age, but normal relative to the bone age. Patients with IDP appear to exhibit a delay in maturation of both the adrenal cortex and the hypothalamo-pituitary gonadal axis usually with short stature and retardation of the bone age. The importance in measurements of adrenal androgens in the diagnosis of HH and of IDP is emphasized.
The effects of parathyroid hormone (PTH) administered to six young normal adult subjects on protein, calcium, magnesium, phosphorus, sodium and potassium concentrations in parotid saliva have been studied in relation to the salivary flow rate. Stensen's duct was cannulated and excretion patterns of the constituents determined before and after stimulation of saliva production by lemon juice. After a control period (period 1), 50 U of PTH were given i.v. followed by an infusion of 2 U/min for 60-90 min (period 2). In the absence of any detectable changes in plasma, PTH induced a significant rise of salivary protein, calcium, and phosphorus concentrations at rest and following lemon juice stimulation, and of sodium concentration, but only at high flow rates for the latter. PTH did not change magnesium and potassium excretions significantly. Control experiments without PTH were performed on five other subjects. Protein, phosphorus and potassium concentrations did not change significantly between period 1 and period 2. Calcium and sodium excretions were reduced and magnesium excretion increased during period 2. These results provide evidence that PTH acts on the parotid gland by affecting protein secretion and electrolyte transport. Possible mechanisms of these changes are discussed.
Using a newly characterized anti-melatonin serum it has been possible to establish human serum melatonin concentrations at short time intervals during 24h. A clear circadian rhythm with peak values during the dark phase was demonstrated in both men and women. Values (pg/ml;mean +/- SE) were as follows: females 02.00h: 130 +/- 7, 18.00h: 45 +/- 5 males 02.00h: 140 +/- 11, 18,00H: 70 +/- 5. The estimation (pg/ml; mean +/- SE) of melatonin in human serum (males: 63 +/- 22 and females: 100 +/- 45) and cerebrospinal fluid simultaneously taken has shown that melatonin is lower in cerebrospinal fluid (males: 59 +/- 33 and females: 57 +/- 28). Blanks are not subtracted.