Search PubMed⌕ Search

Biomedical subjects

M Berger

Publications and source records attributed to M Berger.

At least 631 records · Page 35Linked to original sources

Skeletal muscle glycolysis, oxidation, and storage of an oral glucose load.

Although muscle is considered to be the most important site for postprandial glucose disposal, the metabolic fate of oral glucose taken up by muscle remains unclear. We, therefore, employed the dual isotope technique (intravenous, [6-3H]-glucose; oral, [1-14C]glucose), indirect calorimetry, and forearm balance measurements of glucose, lactate, alanine, pyruvate, O2, and CO2 in nine normal volunteers to determine the relative importance of muscle glycogenic, glycolytic, and oxidative pathways in disposal of an oral glucose load. During the 5 h after glucose ingestion (1 g/kg), 37 +/- 3% (24.9 +/- 2.3 g) of the load was oxidized and 63 +/- 3% (42.8 +/- 2.7 g) was stored. At least 29% (19.4 +/- 1.3 g) was taken up by splanchnic tissues. Muscle took up 26% (17.9 +/- 2.9 g) of the oral glucose coincident with a 50% reduction in its oxidation of fat. 15% of the oral glucose taken up by muscle (2.5 +/- 0.9 g) was released as lactate, alanine, or pyruvate; 50% (8.9 +/- 1.4 g) was oxidized, and 35% (6.4 +/- 2.3 g) was available for storage. We conclude that muscle and splanchnic tissues take up a comparable percentage of an oral glucose load and that oxidation is the predominant fate of glucose taken up by muscle, with storage in muscle accounting for less than 10% of the oral load. Thus, contrary to the prevailing view, muscle is neither the major site of storage nor the predominant site of disposal of an oral glucose load.

Administration, Oral↗

Abdominal x-ray and pathological findings in distal unishunt obstruction.

A new x-ray finding suggesting distal obstruction of the Unishunt is described. Fusiform swelling of the distal slit valve ("pantaloon sign") seen on an abdominal x-ray film was associated with surgically proven distal shunt obstruction in 8 of 10 patients. No patient with a normally functioning (n = 67) or proximally malfunctioning shunt (n = 6) displayed this abnormality. This finding in association with clinical and computed tomographic evidence of shunt malfunction can direct surgical revision to the appropriate site. The pathology of distal shunt malfunction is also reviewed.

Cerebrospinal Fluid Shunts↗

Prolonged influence of a neonatal cyproterone acetate treatment on renal androgen binding in mice.

To determine whether neonatal endogenous androgens influence adult renal androgen binding, newborn male mice were injected from 1 to 10 days of age with cyproterone acetate and newborn females with testosterone from 1 to 10 days and from 20 to 40 days of age. In controls, at adulthood, the total cellular androgen receptor content was significantly higher in males (1700 +/- 200 receptors per cell) than in females (1060 +/- 50) and, as expected, the nuclear receptor content was 12-fold higher in males. While the total number of receptors (1650 +/- 200 per cell) was unchanged in adult males neonatally treated with cyproterone acetate, their distribution between cytosol and nucleus was similar to that in control females despite normal circulating and renal testosterone levels. The nuclear receptors represented 50, 7 and 11% of the total receptors in control males, control females and cyproterone acetate-treated males, respectively. The very low levels of nuclear receptors present in the kidney of cyproterone acetate-treated males probably explain the decreased sensitivity of this organ to testosterone. The nuclear receptor accumulation measured in adult animals after a single injection of testosterone did not seem to be affected by neonatal hormonal manipulations.

Age Factors↗

Preliminary characterization, androgen-dependence and ontogeny of an abundant protein from mouse vas deferens.

Polyacrylamide gel electrophoresis analysis revealed that the vas deferens of adult mouse contains a major protein. Mouse vas deferens protein is a basic glycoprotein with a molecular weight of 34,800 +/- 300. The protein represents 17 +/- 0.7% and 42 +/- 2.4% of soluble proteins from homogenate and luminal fluid respectively, an estimate based on densitometric scanning of polyacrylamide gels. The protein originated from the vas deferens since it was not detected in blood plasma or in sexual organs and it was still present after ligation of the epididymis. Changes in androgen status of the animal markedly affected the vas deferens protein. After castration a progressive decrease in the protein was observed and its relative percentage dropped to 2 +/- 0.4% after 45 days. The concentration of the protein returned to precastration levels after 2 weeks of testosterone treatment but oestradiol, progesterone and corticosterone were ineffective in this respect. The vas deferens protein was not synthesized in significant amounts until animals were 20 days old and its concentration increased rapidly from 20 to 30 days in concert with the pubertal increase of androgens in the vas deferens.

Animals↗

Tumor necrosis factor is the major monocyte product that increases complement receptor expression on mature human neutrophils.

Interleukin-1 (IL-1) and other monocyte products have several important effects on the systemic response to infection in addition to their roles in lymphocyte stimulation. The present studies were carried out to determine whether products of stimulated monocytes activated circulating neutrophils (PMN) to increase expression of receptors for C3b (CR1) and C3bi (CR3), which are necessary for optimal margination, migration, and phagocytosis. Supernatants of human mononuclear cells that had been stimulated with lipopolysaccharide (LPS) or purified protein derivative (PPD) contained both tumor necrosis factor (TNF) and IL-1 and increased CR1 and CR3 expression on isolated PMNs. Supernatants of unstimulated cultures, media alone, or LPS or PPD alone had little or no effect. Supernatant effects were detectable at 1:3,000 final dilution and appeared to have a characteristic slow time course. These supernatants also caused dose- and time-dependent secretion of PMN granular constituents, but maximal receptor expression was accompanied by secretion of less than 10% of the cells' content of lysozyme and less than 16% of the B12 binding protein. Immunoadsorption studies showed that the supernatant's activity could be removed by anti-TNF but not by anti-IL-1. Recombinant IL-1 had no effect on receptor expression, but recombinant TNF increased CR1 and CR3 expression with kinetics similar to the supernatants. These results thus indicate that TNF is the major monocyte product that increases CR1 and CR3 expression on mature blood neutrophils. This would result in increased margination and phagocytic activity and may be an important systemic effect that would help the host eradicate infection.

Calcium↗

[Atrial natriuretic factor in patients with type 1 diabetes mellitus in various stages of diabetic nephropathy].

In this study we investigated circulating atrial natriuretic factor (ANF) concentrations in patients with different stages of diabetic nephropathy. Type 1 diabetic patients with incipient or overt nephropathy had elevated plasma ANF concentrations when compared with nonnephropathic diabetics and normals. Patients having a hyperfiltration only, which might be a risk factor for the development of diabetic nephropathy, had also elevated ANF concentrations. No correlation could be found between ANF concentrations and blood pressure, diabetes duration, age, or parameters of metabolic control. These findings may indicate a role of ANF in the development of diabetic nephropathy. Long-term follow-up studies should be performed to assess the prognostic and diagnostic importance of plasma ANF determinations in diabetic patients.

Adult↗

Hypoglycemic effect of subcutaneously injected biosynthetic human proinsulin in healthy man.

The effects of equipotent subcutaneously injected amounts of biosynthetic human proinsulin and biosynthetic human NPH insulin on blood glucose levels were compared in healthy male volunteers. Mean blood glucose levels decreased to approximately 50 mg/dl after injection of NPH insulin and to 46 mg/dl after injection of proinsulin. This difference reached statistical significance only between 200 and 310 min. after injection. Blood glucose levels rose only marginally thereafter, but increased promptly after ingestion of the standard meal. No differences were observed between the groups. The serum insulin levels reflected the known time insulin curves after NPH injection. The maximum of the proinsulin levels occurred about 4 hours after the injection. Subcutaneous injection of equipotent amounts of biosynthetic human proinsulin and biosynthetic human insulin have similar effects on blood glucose levels.

Adult↗

The USA-USSR collaborative cross-cultural comparison of autogenic training and thermal biofeedback in the treatment of mild hypertension.

We have conducted a cross-cultural (USA and USSR) comparison of thermal biofeedback (TBF) and autogenic training (AT) to a self-relaxation control condition in 59 unmedicated males with mild hypertension. Identical assessment and treatment protocols were carried out in both settings (Albany, New York, and Moscow). Treatments were delivered in small groups on an outpatient basis twice per week for 10 weeks. Results showed comparable, significant (p less than .05), short-term decreases (M = 8.5 mm Hg) in diastolic blood pressure (DBP) for both treatments at both sites. However, the Soviet patients, starting with significantly (p less than .01) higher systolic blood pressures (SBPs), showed significant decreases (M = 12.8 mm Hg) in SBP, whereas the American patients did not change appreciably (M = 4.6 mm Hg). During follow-up, the treated Soviet patients showed significantly (p less than .05) better maintenance of treatment effects, from 3 months to 1 year, than did the American patients. At 1 year, 75% of the treated Soviet patients had DBPs less than 90 mm Hg, whereas only 24% of the American patients had comparable DBPs.

Adult↗

Relationship between membrane depolarization and extracellular calcium influx during neutrophil activation.

To better define the relationship between membrane depolarization and extracellular Ca2+ influx during neutrophil activation, we compared stimulation by elevating the extracellular K+ concentration, [K+]o, with stimulation by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Elevation of [K+]o resulted in uniform depolarization of the entire population of cells. This was associated with an influx of Ca2+ that was temporally delayed and quantitatively less than that induced by fMLP. K+ depolarization also caused increased expression of type 1 (C3b/C4b) complement receptor (CR1) and type 3 (C3bi) complement receptor (CR3), but the increments were less than with fMLP. We then used pertussis toxin to determine if guanosine triphosphate (GTP)-binding proteins were involved in these responses. Toxin inhibited the fMLP-induced membrane depolarization as well as the uptake of extracellular Ca2+ and the expression of both CR1 and CR3 induced by the chemoattractant. This indicates that the fMLP receptor is not directly coupled to an ion channel. The membrane depolarization induced by elevating [K+]o was not inhibited by toxin, but the uptake of Ca2+ and the increased expression of CR1 and CR3 were all significantly inhibited. The toxin failed to block increased CR1 and CR3 expression induced by ionomycin, demonstrating that its effects were not attributable to general toxicity. The results suggest that voltage gating is not the major mechanism by which polymorphonuclear leukocytes (PMNs) increase their permeability to extracellular Ca2+. Initial signals, whether generated by chemoattractants binding to their receptors or by small initial influxes of extracellular Ca2+, must be amplified by pertussis toxin-sensitive steps to fully increase the Ca2+ permeability and optimally activate the cell.

Calcium↗

[Extracorporeal shockwave lithotripsy in sedation-analgesia].

The aim of the present study was to examine the effects of combined sedation and analgesia during extracorporeal shockwave lithotripsy using the Dornier lithotriptor HM III. We used a combination of a benzodiazepin derivatives with an opioid. We tested the dosage of drugs needed in relation to the length of treatment, the size of the stone and the overall energy output of the lithotriptor. In addition, continuous records were made of the patient's blood pressure and the oxygen saturation in the blood, with and without oxygen insufflation. Our results show that sedation combined with analgesia is a reasonable and useable alternative to general or regional anaesthesia for extracorporeal lithotripsy.

Anesthesia, Conduction↗