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Biomedical subjects

M Berger

Publications and source records attributed to M Berger.

At least 1,027 records · Page 57Linked to original sources
PubMed1977

Effect of luteinizing hormone (LH) and LH-releasing hormone (LHRH) on testosterone production in vivo, in fetal rabbit testis in late gestation.

Plasma and tesicular testosterone were measured by radioimmunoassay in the 29-day-old rabbit fetus receiving an injection of saline solution, LH or LHRH. 30 min following the injection of 5 microgram LH into the umbilical vein, testosterone levels were significantly increased by 287% in the plasma and 293% in the testis, compared with controls receiving saline solution. The injection of 2 microgram of LHRH under the same conditions significantly increased testicular testosterone by 256% and plasma testosterone by 746%. The results show that the fetal rabbit testis, at the end of gestation, is capable of responding to LH stimulation. The hypophysio-testicular axis is apparently functional at this stage of gestation, as shown by the response to LHRH.

Animals↗
PubMed1977

Ultrasonic evaluation of the obstructed duplex kidney.

The problem of a duplex collecting system associated with an obstructed ectopic ureter or ureterocele is common in pediatric urology. Four such patients were studied by gray scale ultrasound which was useful in demonstrating the dilated upper pole collecting system as well as an ectopic ureter and a ureterocele. Although the diagnosis of a nonfunctioning upper pole unit in a duplex kidney is usually suggested by the urogram, ultrasound provides a noninvasive means of confirmation which is independant of function. Further, ultrasound-guided puncture with antegrade pyelography demonstrates the course of the ectopic ureter, thus providing a more complete preoperative evaluation.

Adult↗
PubMed1977

The mechanism of urinary concentration in nephrogenic diabetes insipidus.

The authors have evaluated urinary adenosine 3',5'-monophosphate (cyclic AMP) excretion and renal function during Pitressin administration, hypertonic saline administration, and water deprivation in two siblings with vasopressin-resistant diabetes insipidus and in normal control subjects. After vasopressin administration normal subjects experienced a 2-fold rise in urinary cyclic AMP excretion from 3.2 +/- 0.7 to 5.6 +/- 1.3 nmol/min (P less than 0.001) whereas cyclic AMP excretion was unchanged in both patients (patient AC 4.4 +/- 0.9 to 4.3 +/- 2.1; patient TC 2.2 +/- 0.9 to 2.6 +/- 0.9 nmol/min) with nephrogenic diabetes insipidus (NDI). Urinary cyclic AMP excretion was measured during infusion of 2.5% saline, after vasopressim administration, and after water deprivation. Cyclic AMP excretion was not different from control values in the NDI patients during any of the experimental conditions. Furthermore, there was no difference in cyclic AMP excretion when periods of dilute urine excretion (patient AC 4.5 +/- 1.1; patient TC 2.1 +/- 0.8 nmol/min) were compared with periods when urine concentration was greater than that of plasma (AC 3.5 +/- 1.3; TC 1.8 +/- 0.9 nmol/min). Both subjects responded to parathyroid hormone infusion with a 2-fold increase in urinary cyclic AMP excretion. Excretion of concentrated urine was paralleled by a marked decrease in urine flow to less than 1 ml/min/m2. During periods of hypotonic urine excretion (Uosm/Posm less than 1.0) average glomerular filtration rate (GFR) in patient AC was 67.0 +/- 3.0 ml/minm2 whereas in patient TC it was 70.1 +/- 8.1 ml/min/m2. When each patient was excreting a hypertonic urine (Uosm/Posm greater than 1.0) after fluid deprivation their GFR had decreased significantly (P = 0.001) to 31.6 +/- 8.9 and 33.3 +/- 10.3 ml/min/m2, respectively. Ability of these two subjects with NDI to concentrate their urine to Uosm/Posm greater than 1.0 in the absence of an increase in urinary cyclic AMP but associated with a decrease in GFR to 50% normal indicates that urinary concentration was effected by a reduction in GFR rather than a partial response to antidiuretic hormone (ADH). Their ability to concentrate their urine during periods of modest volume depletion would protect them from progressing to more severe stages of dehydration and result in the relatively benign course of their disease. It is feasible that in patients previously reported to have had clinically "partial" NDI this mechanism may have been operative.

Adolescent↗
PubMed1977

Toxic psychosis due to cyproheptadine in a child on hemodialysis: a case report.

In 1971 Simmons et al. presented evidence that children receiving regular dialysis therapy required approximately seventy percent of recommended caloric intake to achieve normal growth. Since that time, pediatric nephrologists and dietitians have strived to meet that requirement. In an effort to attain adequate caloric intake, cyproheptadine, a known appetite stimulant, was prescribed to a child on chronic hemodialysis. The following reports the unexpected complication of toxic psychosis that resulted.

Child↗
PubMed1977

Effects of metformin on glucose metabolism of isolated perfused rat skeletal muscle.

It was investigated whether N,N-dimethylbiguanide hydrochloride (metformin) lowers blood glucose levels by stimulating glucose uptake of skeletal muscle using the isolated perfused rat hindquarter. Osborne-Mendel rats were subjected to a special feeding regimen (food intake only 2 h daily) and were treated orally by metformin (125 mg/kg body weight twice daily) or placebo, respectively. The hypoglycemic effect of metformin could be demonstrated. Thereafter, control rats were perfused in the absence, and metformin-treated rats in the presence of added metformin (0.67 microgram/ml perfusate). Neither the basal nor the insulin-stimulated glucose uptake of skeletal muscle was increased by metformin. Lactate and alanine release, O2 uptake as well as the tissue metabolite levels of glucose, lactate, pyruvate, ATP and creatine-P remained unaffected. On the other hand, metformin caused a significant decline of lactate oxidation as well as an elevated glycogen content of skeletal muscle. It is proposed that the inhibition of lactate oxidation may under certain conditions be instrumental in the development of lactic acidosis associated with biguanide therapy.

Adenosine Triphosphate↗
PubMed1977

Cardiovascular risk factors in gross obesity.

In 500 obese patients (146 men, mean age 37 +/- 13 years, Broca index 147 +/- 24; 354 women, mean age 36 +/- 14 years, Broca index 151 +/- 28) cardiovascular risk factors (RF) were investigated. The most frequent RF was hypertension (71 per cent), followed by glucose intolerance (49 per cent), hypertriglyceridemia (31 per cent), hypercholesterolemia (22 per cent) and hyperuricemia (22 per cent). Only 12 per cent of the patients were without RF. These patients were younger and less obese than the patients with RF. The prevalence of RF increased with increasing age and overweight. Analysis revealed significant correlations between overweight and blood pressure, blood glucose, insulin and age. Significant correlations between age and hypertension, blood glucose cholesterol, triglycerides and overweight were detected. The correlation between overweight and the sum of all RF was higher (r = 0.35) than the one between age and the sum of all (r = 0.23). Obese patients had a high prevalence of RF. Increasing overweight and (to a lesser extent) age are both associated with increased prevalence of RF. On the basis of the prevalence of RF, patients with gross obesity (Broca index greater than around 150) were considered to be at a high risk in respect of coronary heart disease.

Adult↗
PubMed1977

Simultaneous iothalamate, creatinine, and urea clearances in children with renal disease.

Glomerular filtration rate (GFR) is often used to evaluate and manage patients with renal disease. Few studies in children have compared accurate estimations of GFR (clearance of inulin and/or iothalamate) with the clearance of creatinine which, because of simplicity, has been used as an approximation of GFR. At reduced levels of GFR, studies in adults suggest that the mean of the creatinine and urea clearances closely approximate the GFR. The present investigation shows that the clearance of creatinine approximates the GFR at normal levels; however, at reduced levels the creatinine clearance and the mean of the creatinine and urea clearances both overestimate the GFR as measured by iothalamate. The clearance of creatinine remains a useful clinical tool if its limitations at low levels of GFR are realized.

Adolescent↗
PubMed1977

Effect of starvation on muscle glucose metabolism: studies with the isolated perfused rat hindquarter.

Studies in man and experimental animals suggest that the metabolism of glucose by skeletal muscle is depressed during starvation. To investigate the basis for this, the effect of starvation on the uptake and disposition of glucose in skeletal muscle was studied in the isolated perfused rat hindquarter. In contrast to earlier work carried out in heart, neither glucose uptake, whether stimulated by insulin or exercise, nor glycolysis were depressed by 48 hr of starvation or by perfusion of the hindquarter with acetoacetate, palmitate, or octanoate. Glucose oxidation, assessed from the oxidation of 1-[14C]lactate, was depressed by approximately 75% in starved rats and by 30% in fed rats perfused with acetoacetate. Exercise increased lactate oxidation 10-fold in both fed and starved rats; however, the relative difference between the groups persisted. In general, changes in lactate oxidation were paralleled by changes in the activity of pyruvate dehycrogenase (active form). The data suggest that glucose metabolism in skeletal muscle is inhibited during starvation at the step of pyruvate oxidation and that this inhibition persists during exercise. The also suggest that the diminution of glucose uptake that occurs in skeletal muscle of intact organisms during starvation may not be related to the presence of high concentrations of free fatty acids and ketone bodies.

Acetyl Coenzyme A↗
PubMed1977

Dietary management of children with uremia.

To a large extent,the principles of dietary management of children and adults with chronic renal failure are similar. Certainly, both require some degree of protein restriction to prevent the adverse effects that occur when uremic manifestations are present; the need for calories--to allow for adequate growth--is extremely important to uremic children. It is of lesser importance to adults. However, its strategic importance to children cannot be overemphasized and needs to be fully appreciated by dietitians who are increasingly being called on to care for uremic children referred to adult dialysis units.

Adolescent↗
PubMed1977

Ribosomal and transfer RNA contents of the normal and pathologic human thyroid gland.

One hundred and seventy seven pieces of normal or pathologic thyroid tissue from 17 patients were assayed for rRNA, tRNA and DNA content. The tRNA/DNA and rRNA/DNA ratios in pathologic tissue were statistically compared with the same ratios in normal tissue. In toxic adenoma (5 cases) and anoplastic cancer (2 cases), both ratios were increased. In cold nodules (9 cases), there was in increase of the tRNA/DNA ratio only in 1 case, of the rRNA/DNA ratio only in 4 cases, and of both ratios in 3 cases. In one case of a cold nodule in a Basedow's disease gland, there was no modification of these ratios. In Basedow's disease (3 cases), there was an increase of rRNA/DNA ratio only in one case.

DNA↗