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Biomedical subjects

M Popa

Publications and source records attributed to M Popa.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[The involvement of adenosine and adenosine deaminase in experimental myocardial infarct].

By the ligature of the left coronary artery in the rat anesthetized with nembutal (10 mg/100 i.p.) a significant increase of the 5'-nucleotidase activity (Wooton method) was noticed 10 minutes after the left ventricle infarction (from an average value of 1038.5 +/- 187 mU/g tissue to 1537 +/- 225 mU/g fresh tissue). The adenosine desaminase levels spectrophotometrically determined by Denstedt technique, do not appear significantly modified 10 or 30 minutes after the left ventricle infarction. The chromatographically determined adenosine levels, by HPLC technique, decrease from the average value of 11.63 +/- 1.4 micrograms/mg PT to 8.60 +/- 1.0 micrograms/mg PT 30 minutes after infarction. The observed changes are explained by the conditions of hypoxia in the infarcted ventricle which lead to the raise in adenosine levels by activating the 5'-nucleotidase and their depression by a very fast metabolism of the same substance.

5'-Nucleotidase↗
PubMedDate not supplied

Direct assay of 3-methoxy-4-hydroxy-phenylglycol (MHPG) in human saliva; a new approach in the assessment of noradrenergic function.

The present paper offers a simple, reliable and specific method for the evaluation of salivary level of conjugated MHPG in 16 children (5-16 years) selected as control group. In the chosen group, we established the urinary level of NA: 17.64 +/- 1.38 micrograms/24 h, of A: 5.87 +/- 0.44 micrograms/24 h, of MHPG: 1.62 +/- 0.14 mg/24 h, of VMA: 1.54 +/- 10.10 mg/24 h. In all patients we assayed salivary MHPG: 57 +/- 5.25 mg/ml; in only 6 patients we also determined salivary NA: 2.21 +/- 0.11 micrograms/l and A: 0.25 +/- 0.03 micrograms/l. The MHPG in saliva correlates with urinary MHPG but doesn't correlate with NA in saliva or in urine. The assay of salivary MHPG may represent a non-invasive procedure of evaluation of noradrenergic tonus in children.

Adolescent↗
PubMedDate not supplied

[Bacteria detected in the duodenal aspirate of patients with biliary tract disorders].

In 614 patients with pains in the right hypochondrium the cyto-bacterioscopy and bile culture were performed. In 575 patients bile samples were obtained by sterile catheterization and in 39 patients by biliary tract puncture during surgical intervention. It resulted that for a reliable cyto-bacterioscopic examination and its agreement with bile culture results it is necessary to investigate only the samples with pH greater than or equal to 5 and during the first two hours after their collection. The isolated bacterial species can be considered to be etiologic agents of the biliary infection depending on the following parameters: significant quantitative threshold of minimum 10(5) colony forming units per milliliter, presence of inflammatory reaction and activity of the gastric acid barrier.

Bacteria↗
PubMedDate not supplied

Standard EEG might predict the intensity of the vasotocin effects on REM sleep in prepubertal children.

Standard electroencephalographic (EEG) anomalies were correlated with the intensity of the acute intranasally administered arginine vasotocin (AVT) effects on the REM sleep of 27 healthy prepubertal children (aged between 4 and 13 years). In comparison with saline controls, AVT greatly enhanced REM sleep parameters in subjects with alpha rhythm anomalies, theta waves or with low-voltage EEG as well as in those without hyperpnea-induced EEG anomalies, than in those without (and respectively with) these anomalies. No statistical significant correlation could be established between the intensity of AVT effects on sleep and age, sex, appearance of incidental delta waves or of paroxysmal activities. It is concluded that standard EEG might predict the intensity of the hypnogenic effects of AVT in prepubertal children. The present results support the hypothesis that AVT could be involved in the maturation of the electrical activity of the brain.

Adolescent↗
PubMedDate not supplied

Vasotocin and sleep in prepubertal boys: its suppression by valproic acid.

In order to investigate a possible involvement of the GABA-ergic neurotransmission in the effects of arginine vasotocin (AVT) hormone on human sleep, we administered in 20 healthy prepubertal boys (aged 7-12 years), by an intra-nasal route, AVT (1 microgram) alone or 10 minutes after an intra-nasal dose of valproic acid (VA) (1, 10 and 50 micrograms). Whether the dose of 50 micrograms VA alone produced a quasi-total insomnia for all recording time (3h), the doses of 1 and 10 micrograms VA were without any apparent effect on sleep parameters. However, whatever be the dose of VA, it produced a total suppression of the hypnogenic effects of AVT. The results suggest not only a possible involvement of the GABA-ergic mechanisms in mediating the hypnogenic properties of AVT in man, but also that VA could be used in the treatment of excessive sleep syndromes, especially of narcolepsy.

Administration, Intranasal↗
PubMedDate not supplied

Morphotypic aspects in the cryptorchidic child.

The morphotype of 40 children with cryptorchidism (18 bilateral, 22 unilateral), selected by complex endocrine examination, was assessed in relation to age and clinical form of cryptorchidism. The morphotype was established on the basis of 9 anthropometric parameters (weight, stature, pube-ground distance, a-a, thr-thr, thoracic, abdominal, hips and cephalic circumferences). The malformed lot consists of 28 children with common and 12 with symptome cryptorchidism (5 adiposogenital, 3 male Turner's syndrome and 3 with gonadal dysgenesis). In the child with symptom cryptorchidism, the morphogram reveals, irrespective of age, a morphotype which corresponds in point of absolute dimensions and proportions, to the somatotype in which cryptorchidism as a symptome is included. The child with common cryptorchidism has irrespective of age, a normal or short stature and is underweight. Compared to the stature, the head is small, the lower limbs are short, the trunk is long and the hips are well developed. In our series of common cryptorchid child, the most marked statural deficit was found between 11 and 15 years as well as under the age of 6.

Body Constitution↗
PubMedDate not supplied

Circadian rhythm of beta-endorphin in the plasma of clinically healthy subjects and in patients with adrenocortical disorders.

Immunoreactive beta-endorphin was determined in the plasma of 37 elderly subjects (73 +/- 7 years of age), in 3 young or young adult subjects without adrenal disease, in 4 women with clinical adrenogenital syndrome, in 1 man with Cushing's disease. Immunoreactive beta-endorphin in plasma was measured by radioimmunoassay in six samples of each subject collected at 4-hour intervals over a 24-hour span. The observation of a circadian rhythm in circulating immunoreactive beta-endorphin with highest values during the late night and early morning hours is extended to elderly subjects in the 8th decade. The beta-endorphin plasma concentrations in the few clinically healthy young adult subjects studied fell within the same range. The circadian variation of the group of elderly subjects was used as reference in the clinical evaluation of plasma beta-endorphin concentrations in patients with pituitary-adrenocortical disorders. The need for circadian rhythm qualified reference values is shown by the observation of the circadian variations of circulating immunoreactive beta-endorphins in the patients with adrenogenital syndrome and Cushing's disease in whom abnormalities in the concentration of circulating beta-endorphin were found at certain circadian stages but not at others.

Adolescent↗
PubMedDate not supplied

The assessment of the dopaminergic tonus by urinary determinations of homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) in normal, obese and GH-deficient short children.

In order to assess the dopaminergic tonus, urinary determinations of HVA and DOPAC and also of noradrenaline (NA), adrenaline (A), and methoxyhydroxyphenylglycol (MHPG) were performed in 86 obese children, 11 growth hormone (GH)-deficient short children and also in 40 control children. Part of the obese patients were subjected to a low carbohydrate, low calorie diet and also to short-term (9-14 days) courses of diethylpropion (DEP) 50 mg/day, meclofenoxate (MEC) 100 mg/day and thyroid extract (THE) 1-2 mg/kg/day. The GH-deficient patients received only THE in substitutive (5-10 mg/kg/day) doses. Significative correlations between DOPAC and age, weight and height were found in controls. In the obese group a significantly increased mean level of HVA was found (1.45 +/- 0.09 mg/24 h vs 1.15 +/- 0.10 in controls). The excretion of DOPAC was slightly greater but far from significance. There was also a significant decrease of HVA but not DOPAC in the DEP-treated obese. The rest of the drugs and the diet alone were not effective in any way. Normal levels in all metabolites except NA and A were found in GH-deficient short children. The therapy with thyroid extract did not alter the excretion levels. These findings indicate that in infantile obesity the dopaminergic tonus is somewhat increased but its pathophysiological significance is doubtful. In GH-deficient short children of standard appearance the dopaminergic tonus seems to be undistinguishable from normal.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Sleep-induced GH release in otherwise GH deficient children having short stature; a possibly new variant of GH neurosecretory dysfunction (GHND).

Sleep and exercise are considered physiologic stimuli of growth hormone (GH) release from the pituitary. They were used to some extent for the assessment of GH reserve in growth disorders of supposedly pituitary origin. In order to better establish the diagnostic value of the sleep test, we studied 34 children of both sexes aged 6-14 having various degrees of shortness of stature associated with bone age retardation (range of the latter: 3-10 years). Eight healthy controls of the same age were also subjected to the sleep test. The latter was begun at 10:00-11:00 a.m. generally in a dark room under polygraphic control. The subjects were fed a standard breakfast at 8:00-8:30 a.m. After thirty minutes of steep or after reaching the IVth stage of slow-wave sleep, the children were awakened and samples of venous blood for GH determinations were drawn. Two other GH reserve tests were also performed in other days, usually insulin-induced hypoglycemia and glycine intravenous loading. Except sleep, no other GH provocative tests were performed in controls. In normal GH reserve children (21/34) according to other tests, the sleep test was positive (i.e. peak values greater than 15 microU/ml) in 7 cases and the mean GH response was not significantly smaller than the peak recorded after insulin-induced hypoglycemia. In abnormal GH reserve, presumably hypopituitary children (13/34) according to other tests, the sleep confirmed the other tests in 8 cases. In five cases of clinically and endocrinologically "hypopituitary" dwarfism, the sleep test revealed a normal response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Serum-to-saliva transfer of the immunoreactive insulin (IRI) in children with obesity associated with insulin-resistance.

Assuming that the serum-to-saliva transfer of insulin reflects internalization and re-cycling of the hormone in the membrane-located binding sites of salivary epithelial cells and that these cells have in obesity a'marked decrease in insulin receptor content, it has been postulated that insulin resistance in infantile obesity can be detected by the changes in the salivary immunoreactive insulin during the oral glucose tolerance test (OGTT). The study included 31 obese children and adolescents of both sexes, subjected to OGTT. Samples of blood and saliva were collected at 30, 60, 120, 180 and 240 minutes for determinations of glucose and IRI. The blood glucose values were generally normal whereas IRI was excessively high. The dynamics of salivary IRI was similar (easy peak followed by slow descent) with the mean serum values but lower by about two-thirds, and the peak was 30-60 minutes delayed. The serum IRI values correlated significantly with the saliva ones at all time-intervals except for the 30-minute ones. The serum IRI values were significantly lower at the 30-minute time interval, whereas the salivary IRI were the lowest (and of borderline significance) at the 60-min. time interval. The mean glucose/kg doses given orally were not significantly different in the two groups. It was concluded that a hormonal activity detectable by IRI assay through the PEG separation method does exist, with a concomitant variation of serum-to-saliva transfer as shown by the OGTT test. It was also concluded that since the salivary values are lower, the direction of the flow is from serum to saliva and not the reverse. Finally, on the basis of our data, an "in situ" synthesis of insulin (hormonogenic exocrinism) can not be ruled out.

Adolescent↗
PubMedDate not supplied

Free 3-methoxy-4-hydroxyphenylglycol (MHPG) in human urine: metabolic routes, biochemical and clinical significance in healthy and obese children.

Conjugated MHPG is an indicator of the adrenergic tonus having clinical use in the follow-up of affective disorders, arterial hypotension, anorexia nervosa and recently of obesity. Little is known about the significance of the unconjugated, free MHPG in various body fluids. Nineteen healthy and 38 obese children were studied as regards the urinary excretion of free MHPG (MHPGF), conjugated MHPG (MHPGC), total MHPG (MHPGT) and also free noradrenaline (NA) valnillyl mandelic acid (VMA) and metanephrines (MN). Part of the obese received a short-term course of drug therapy (diethyl-propion-DEP or thyroid extract) and were subjected to a low-carbohydrate diet containing 800-1000 calories a day. The same urinary determinations were made after diet alone or after diet and drug therapy. MHPGC and MHPGT were significantly higher in the obese children. The level of MHPGF was essentially the same in both groups and did not change significantly following any drug or after diet alone. It was concluded that esterification mechanisms are not involved in the pathological states expressing high or low levels of MHPGC. Suggestion is made that these mechanisms may not be saturated unless huge amounts of MHPG outflow from the brain into CSF.

Child↗
PubMedDate not supplied

Decrease of urinary levels of adrenergic metabolites including conjugated MHPG after a short term course of diethylpropion in obese children fed a mixed, low-calorie diet.

A short term course (8-11 days) of diethylpropion 50 mg a day was administered to 12 obese children of both sexes fed a mixed low calorie diet containing about 1000 calories/day. A group of 10 obese children received the same diet and no medication. The sex-distribution was similar in both groups as well as the degree of overweight (appreciated by the Quettelet index). The urinary excretion of some noradrenergic derivative (adrenaline-A, noradrenaline-NA, vanillyl-mandelic acid VMA, metanephrines NM and methoxy hydroxyphenyl glycol-MHPG) and of homovanillic acid (HVA) was measured in both groups before and after drug therapy or diet, respectively. After the diethylpropion course, the urinary mean value of MHPG decreased (2.17 +/- 0.30, mean +/- SE vs 1.47 +/- 0.21) but the significance was borderline. The mean level excretion of NA, VMA, MN and HVA were significantly lower following diethylpropion. No significant change was observed in the diet-only group of patients as regards the same determinations. These observations are not entirely explained by the previous pharmacologic knowledge on diethylpropion and other sympathomimetic amines.

Adolescent↗