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Biomedical subjects

T Bistritzer

Publications and source records attributed to T Bistritzer.

At least 55 records · Page 3Linked to original sources

The effect of prenatal administration of dexamethasone and ritodrine on cord blood cortisol and glucose concentrations in premature infants with respiratory distress syndrome.

The influence of maternal dexamethasone and ritodrine administration during pregnancy on cord blood cortisol and capillary serum glucose concentrations and on the incidence of respiratory distress syndrome (RDS) was studied in 30 premature infants (gestational age 27-36 weeks), and compared with a matched control group of 37 premature infants where no such medications were administered. RDS occurred less often in the treated group of infants (13.3%) than in the controls (35.1%, p < 0.01). The healthy treated infants had a significantly lower mean umbilical cord plasma cortisol concentration (5.5 +/- 1.8 ug/dl, mean +/- SD) than that observed in the controls (11.2 +/- 3.9 ug/dl, p < 0.01). Mean cord plasma cortisol concentrations increased with duration of pregnancy. No significant difference in the capillary serum glucose at 30 minutes post-delivery was found between the healthy, RDS, treated and non-treated infants. No adverse effects of steroid and ritodrine therapy were observed.

Blood Glucose↗

Non-insulin dependent diabetic patients have increased glucose uptake in red blood cells.

The kinetic characteristics of 3-O-methyl glucose (3-OMG) uptake were examined in red blood cells (RBC) from seven normal individuals (controls) and nine patients with non-insulin-dependent diabetes mellitus (NIDDM) treated with diet and oral hypoglycemic medication. Comparison of rates of 3-OMG uptake at 5 different substrate concentrations revealed significantly higher overall 3-OMG uptake in the diabetic group (P less than 0.0001). Kinetic parameters obtained for individual subjects showed there was not a significant difference in the Km between the diabetic (3.17 +/- 0.45 mM; mean +/- SE) and the control (2.46 +/- 0.25 mM) groups. However, Vmax was significantly increased (61%; P less than 0.025) in the diabetics (217.8 +/- 28.9 pmol/2 sec per 10(6) cells) compared to controls (135.2 +/- 15.6 pmol/2 sec per 10(6) cells). There was no correlation between HbA1C levels in the diabetic patients and Vmax values for 3-OMG uptake, suggesting that the increased hexose uptake was not accounted for simply by increased glycosylation in these cells. Glucose transport in RBC in hyperglycemic states may be a useful model for delineating the regulation of the non-insulin-mediated disposal of glucose in diabetes.

3-O-Methylglucose↗

Recurrent seizures in children with Shigella-associated convulsions.

Fifty-five children with Shigella-associated convulsions were followed prospectively to investigate their risk of subsequent febrile or nonfebrile seizures. The duration of the follow-up period was between 6.9 and 14.1 years (9.7 +/- 3.1 years). No case of nonfebrile seizures and only 2 cases (3%) of subsequent febrile seizures were observed during this period. We conclude that although febrile and Shigella-associated convulsions share many clinical features, the natural history of these two conditions seems to be distinctly different. Shigella-related convulsions are not associated with an increased incidence of subsequent febrile or nonfebrile convulsions.

Child↗

Does growth hormone influence the severity of phosphopenic rickets?

The severity of bone disease in phosphopenic rickets is not correlated with serum phosphate levels. In order to determine whether growth hormone (GH) secretion may influence rachitic changes, we evaluated the 24 h integrated concentration of growth hormone (IC-GH) in five children with phosphopenic rickets. Two patients with marked clinical and roentgenographic rachitic abnormalities had normal IC-GH levels. In contrast, three patients with low IC-GH levels had mild rachitic changes. We suggest that the level of spontaneous GH secretion may be one factor which influences the severity of phosphopenic rickets.

Adolescent↗

ACTH1-24 stimulates muscle cell glucose uptake.

3H-2-deoxyglucose (2-DG) uptake was measured in L6A-1 rat skeletal muscle cells (a rapidly fusing subclone of L6), following addition of several concentrations (10(-16) to 10(-9)M) of the N-terminal fragment of ACTH1-24 to cells deprived of serum and insulin for 21 hours, but maintained in the presence of (5 micrograms/ml) insulin (stimulated state). There was a marked dose-dependent increase of 2-DG uptake at the various ACTH1-24 (P less than 0.001). There was no correlation between the time of exposure of the cells to serum-free conditions and the rate of uptake of 2-DG at the various ACTH1-24 concentrations both in the basal and insulin-stimulated states. Addition of catochalasin B (50 microM) to the cells, which inhibited both basal and insulin-stimulated uptake of 2-DG (by 70% and 91%, respectively) completely eliminated the enhancement of both of these uptake rates to 10(-12)M ACTH1-24. The results suggest that: 1) ACTH1-24 stimulates carrier-mediated uptake of glucose in skeletal muscle cells. 2) The site of action of ACTH1-24 is on the non-insulin mediated glucose uptake (NIMGU) system. 3) ACTH1-24 may be a useful probe to delineate some of the events associated with the NIMGU pathway.

Animals↗

Deleterious effect of anti-insulin antibodies on diabetes control.

We studied the effect of anti-insulin antibodies (AIA) on glycemia control in patients with insulin-dependent diabetes (IDD) by following the AIA titer changes with time. Although expected to remain constant, AIA levels were found to either increase or decrease in most patients. These AIA titer changes correlated significantly with changes in glycohemoglobin but not with changes in insulin dose. The results suggest that AIA may have a deleterious effect on glycemia control in IDD.

Adolescent↗

Hormonal therapy and pubertal development in boys with selective hypogonadotropic hypogonadism.

The authors have compared the effects of treatment with weekly injections of human chorionic gonadotropin (hCG) with those of monthly testosterone (T) injections in males with hypogonadotropic hypogonadism. There was no significant difference in pubertal development as measured by progression through the Tanner stages, final height, or bone age, with the two treatment regimens. The final testicular volume in patients treated with 5,000 U/week of hCG (14.0 +/- 2.0 ml) was significantly greater than that in patients treated with 250-mg monthly T injections (4.3 +/- 1.8 ml) (P less than 0.01). This study shows that weekly injections of hCG are effective in achieving virilization in hypogonadotropic hypogonadic males, leading to a greater testicular growth than T preparations. Therefore, hCG treatment may have an advantageous effect on the eventual induction of fertility with human menopausal gonadotropin.

Adolescent↗

Differential effects of adrenocorticotropin(1-24) on [3H]2-deoxy-D-glucose uptake in cultured cells derived from different brain regions.

The effect of adrenocorticotropin(1-24) (ACTH(1-24)) on the uptake of [3H]2-deoxy-D-glucose ([3H]2-DG) was compared in cell cultures derived from two regions (hypothalamus, and extrahypothalamic forebrain) of fetal rat brain. Under control conditions, [3H]2-DG uptake was similar in extrahypothalamic (10.9 +/- 1.1 nmol/mg protein/5 min) and hypothalamic (11.9 +/- 1.3) cells. No significant effect of ACTH (1-24) (10(-7) to 10(-5) M) was found on uptake of [3H]2-DG in extrahypothalamic cells. In contrast, in hypothalamic cells, a potent stimulatory effect (P less than 0.0001) up to 174% over the control value of [3H]2-DG uptake was produced by these concentrations of ACTH(1-24). This study suggests that ACTH may be a stimulator of brain glucose uptake, and that this effect varies in different brain regions.

Animals↗

Growth without growth hormone: the "invisible" GH syndrome.

Growth hormone (GH) deficiency, diagnosed by radioimmunoassay (RIA) measurements of GH in blood after provocation or in continuous 24 h samples of venous blood, is usually associated with growth failure. 4 non-obese boys have been identified who had normal linear growth despite apparent GH deficiency by standard RIA. All 4 patients had normal GH concentrations as measured with an IM-9 cell radio-receptor assay (RRA). The RRA/RIA ratio of the 4 patients significantly exceeded that of controls. Thus, these patients secrete a molecule with normal GH receptor binding and bioactivity which is "invisible" to the standard GH RIA. This variant GH is possibly expressed from the human GH-V gene or a mutant allele.

Acromegaly↗

The effect of testosterone therapy on spontaneous growth hormone secretion in boys with constitutional delay.

Testosterone treatment is known to improve growth hormone (GH) secretion in boys with constitutional delay (CD). To determine whether spontaneous GH secretion is normal after treatment, we assessed GH secretion before and after a four- to five-month course of testosterone enanthate in eight adolescents with CD. Before testosterone therapy, the mean (+/- 1 SD) 24-hour integrated concentration of GH (IC-GH) by constant blood withdrawal technique was 1.7 +/- 1.0 micrograms/L (normal range for age, 3.2 to 11.5 micrograms/L), and the IC-testosterone was 1.8 +/- 2.7 nmol/L. Two patients restudied during treatment had normal IC-GH values. After testosterone treatment, the mean IC-GH of the entire group was 3.3 +/- 2.6 micrograms/L, and the IC-testosterone was 6.5 +/- 5.3 nmol/L. Five of eight patients had IC-GH values that were again subnormal. A subnormal IC-GH associated with CD may persist after testosterone therapy is discontinued. Deficiency of spontaneous GH secretion may contribute to short stature and slower growth rates in this patient group. Whether GH therapy in these patients would have a beneficial effect on final height is unknown.

Child↗

Severe dyspnea and dysphagia resulting from an aberrant cervical thymus.

A 5-month-old infant presented with severe dyspnea and dysphagia resulting from a right-sided cervical mass. At 5 months of age, a large aberrant thymus was excised, resulting in the disappearance of all symptoms. Pathological examination showed normal thymus tissue. Since the preoperative chest X-ray film showed a normal thymic shadow and the T-lymphocyte functions were normal, we conclude that this was not an ectopic gland but an undescended thymic implant.

Choristoma↗

Correlation between HbA1c, purified insulins, diabetic control, and insulin antibodies in diabetic children.

Insulin antibodies were determined in sera from 38 children diagnosed as having juvenile diabetes for a duration of 0.7-15.2 years (median = 4.9 years). 8 children were treated with purified porcine insulins from the beginning of their disease, 16 children with bovine insulin NPH alone, and 14 children with non-purified, of whom 9 were later transferred to purified insulins. Serum insulin antibodies were measured by non-specific and specific methods using beef (B) and pork (P) antigens as described by Welborne and Sebriakova, respectively. 12/38 children had insulin binding levels similar to those of normal children, irrespective of the type of insulin used. The concentration of antibodies using radiolabelled B or P insulins as antigens were strongly correlated, by both the non-specific (p less than 0.01) and the specific (p less than 0.01) methods. Children with better score for diabetic control had significantly lower levels of insulin antibodies against B (p less than 0.05) and P (p less than 0.05) than those with poor diabetic control. There was also a significant positive correlation between mean HbA1c concentration and both B and P mean insulin antibody concentration (p less than 0.01). Finally, patients treated with purified porcine insulin had significantly lower levels of antibodies than patients with non-purified bovine insulin (p less than 0.05).

Adolescent↗

Acquired arteriovenous fistula in a child with hemophilia.

A case of a 2 9/12-year-old hemophiliac boy who acquired an arteriovenous fistula in the right cubital fossa is described. This case shows the possibility that such fistulas can be iatrogenically induced in hemophiliac children subjected to repeated venipunctures.

Arteriovenous Fistula↗

Sex reassignment in a girl with 11 beta-hydroxylase deficiency.

A two-month-old infant was referred to our department because of a short penis (2 X 1.2 cm). No testes were palpable. Acceleration of growth and bone age were observed. Laboratory results showed that serum urea, nitrogen, electrolytes and urinary sodium excretion were all normal. However, levels of serum testosterone (2.1 ng/ml), 17-OH-progesterone (1.8 ng/ml), and 11-deoxycortisol (33 ng/ml) were all high. Urinary excretion of 17-ketosteroids and tetrahydro-s (tetrahydro-pregnane-3 alpha, 17 alpha, 21-triol-20-one) were also very high. Analysis revealed a 46 XX chromosome; laparoscopy revealed normal internal female genitalia. The abnormal concentrations of metabolites were corrected by cortisol acetate treatment. Thus, the diagnosis of virilizing congenital adrenal hyperplasia (11 beta-hydroxylase deficiency) was confirmed. Under our guidance the parents raised the infant as a girl. Reduction clitoroplasty and reconstruction of female external genitalia were performed at the age of 22 months. Early medical, psychological and surgical treatment of children with virilizing congenital adrenal hyperplasia should enable them to become normal adults.

Adrenal Hyperplasia, Congenital↗

Hemoglobin A1 and pancreatic beta cell function in cystic fibrosis.

Hemoglobin A1 (HbA1) blood levels were examined in 34 cystic fibrosis (CF) patients aged 1 1/2 to 20 1/2 yr. The mean (+/- SD) HbA1 concentration in the 34 patients was 7.97 +/- 1.16--significantly higher than that in 150 normal children (6.8 +/- 0.8). Oral glucose tolerance tests (OGTT) were performed in 11 patients and blood glucose and insulin concentrations were measured. There was no difference in the fasting blood glucose values between the two groups. Eight children had a normal OGTT, and three showed an impaired OGTT with a delayed peak response in insulin levels. There was a decreased insulin response in all the CF patients. No correlation was found between HbA1 concentration and the age of the patients, nor between HbA1 and the clinical status (Shwachman score). We conclude that insulinopenia in children with CF is not always accompanied by an increment in HbA1, although serial determinations of its level may reveal deterioration in glucose tolerance.

Adolescent↗

Renal glomerular and tubular function following acute insulin deprivation in juvenile diabetes mellitus.

The effects of acute deprivation of insulin on renal glomerular and tubular functions were studied in 10 children with juvenile diabetes mellitus. Serum glucose concentrations were similar when insulin was administered (251 +/- 112 mg/dl) and when it was withheld (306 +/- 130 mg/dl; 0.5 greater than 0.2). Acute insulin deprivation was associated with a significant reduction in glomerular filtration rate, from 151 +/- 48 ml/min/1.73 m2 to 114 +/- 41 ml/min/1.73 m2 (p less than 0.01). The fractional excretion of sodium rose from 0.45 +/- 0.43 to 0.85 +/- 0.54% (p less than 0.05) and was associated with an enhanced natriuresis; the urinary excretion of sodium increased from 1.67 +/- 1.23 to 2.43 +/- 1.72 microEq/min/kg body weight (p less than 0.05), whereas the urinary excretion of phosphate was not significantly altered from control values. During insulin deprivation a drop occurred in the serum concentration of calcium from 10.37 +/- 0.52 to 9.73 +/- 0.61 mg/dl (p less than 0.01) as well as in its urinary excretion from 0.34 +/- 0.24 to 0.24 +/- 0.20 microgram/min/kg body weight (p less than 0.01). The serum concentration of potassium rose from 4.44 +/- 0.41 to 4.96 +/- 0.51 mEq/l, but its urinary excretion was not significantly different from control values. These data suggest that in juvenile diabetes mellitus the acute deprivation of insulin, dissociated from fluctuations in serum glucose concentration, is associated with a fall in glomerular filtration rate, an increased natriuresis, and a modified calcium and potassium homeostasis.

Adolescent↗