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Biomedical subjects

H Bischoff

Publications and source records attributed to H Bischoff.

At least 37 records · Page 2Linked to original sources
PubMed1997

Inhibition of glycogenolysis enhances gluconeogenic precursor uptake by the liver of conscious dogs.

We investigated the effect of inhibiting glycogenolysis on gluconeogenesis in 18-h-fasted conscious dogs with the use of intragastric administration of BAY R 3401, a glycogen phosphorylase inhibitor. Isotopic ([3-3H]glucose and [U-14C]alanine) and arteriovenous difference methods were used to assess glucose metabolism. Each study consisted of a 100-min equilibration, a 40-min control, and two 90-min test periods. Endogenous insulin and glucagon secretions were inhibited with somatostatin (0.8 microgram.kg-1.min-1), and the two hormones were replaced intraportally (insulin: 0.25 mU.kg-1.min-1; glucagon: 0.6 ng.kg-1.min-1). Drug (10 mg/kg) or placebo was given after the control period. Insulin and glucagon were kept at basal levels in the first test period, after which glucagon infusion was increased to 2.4 ng.kg-1.min-1; BAY R 3401 decreased tracer-determined endogenous glucose production [rate of glucose production (Ra): 14 +/- 1 to 7 +/- 1 mumol.kg-1.min-1] and net hepatic glucose output (11 +/- 1 to 3 +/- 2 mumol.kg-1.min-1) during test 1. It increased the net hepatic uptake of gluconeogenic substrates from 9.0 +/- 2.0 to 11.6 +/- 0.6 mumol.kg-1.min-1. Basal glycogenolysis was decreased by drug (9.1 +/- 0.7 to 1.5 +/- 0.2 mumol glucosyl U.kg-1.min-1). Placebo had no effect on Ra or the uptake of gluconeogenic precursors by the liver. The rise in glucagon increased Ra by 22 +/- 3 and by 8 +/- 2 mumol.kg-1.min-1 (at 10 min) in placebo and drug, respectively. The rise in glucagon caused little change in the net hepatic uptake (mumol.kg-1.min-1) of gluconeogenic substrates in placebo (8.2 +/- 0.6 to 9.0 +/- 1.0) but increased it markedly (11.6 +/- 0.6 to 15.4 +/- 1.0) in drug. Glucagon increased glycogenolysis by 22.1 +/- 2.5 and by 7.8 +/- 1.6 mumol.kg-1.min-1 in placebo and drug, respectively. The amount of glycogen (mumol glucosyl U/kg) synthesized from gluconeogenic carbon was four times higher in drug (48.6 +/- 9.7) than in placebo (11.3 +/- 1.7). We conclude that BAY R 3401 caused a marked reduction in basal and glucagon-stimulated glycogenolysis. As a result of these changes, there was an increase in the net hepatic uptake of gluconeogenic precursors and in glycogen synthesis.

Analysis of Variance↗
PubMed1996

Bone marrow uptake of fluorine-18-fluorodeoxyglucose following treatment with hematopoietic growth factors: initial evaluation.

Hematopoietic growth factors (HGF) such as G-CSF and GM-CSF stimulate cell growth of the bone marrow and thereby mitigate the myelotoxic effect of chemotherapy. Using 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) for therapy response monitoring of patients with small-cell lung cancer, both an extension and an intensification of thoracic bone marrow uptake were noted in patients treated with HGF (n = 5) compared to those patients without HGF supplementation (n = 11). FDG uptake was a very sensitive marker of stimulated hematopoiesis, and both the extension and the intensification of uptake have to be noted during HGF therapy.

Adult↗
PubMed1995

The mechanism of alpha-glucosidase inhibition in the management of diabetes.

The development of the alpha-glucosidase inhibitor acarbose provides a new approach in the management of diabetes. By competitive and reversible inhibition of intestinal alpha-glucosidases, acarbose delays carbohydrate digestion, prolongs the overall carbohydrate digestion time, and thus reduces the rate of glucose absorption. After oral administration of acarbose, the postprandial rise in blood glucose is dose-dependently decreased, and glucose-induced insulin secretion is attenuated. Because of diminished postprandial hyperglycemia and hyper-insulinemia by acarbose, the triglyceride uptake into adipose tissue, hepatic lipogenesis, and triglyceride content are reduced. Therefore, acarbose treatment not only flattens postprandial glycemia, due to the primary and secondary pharmacodynamic effects, but also ameliorates the metabolic state in general. In diabetic animals, acarbose reduced urinary glucose loss, the blood glucose area under the curve, and prevented the decrease in skeletal muscle GLUT4 glucose transporters. As a consequence of the reduced mean blood glucose area under the curve, the amount of protein nonenzymatically glycated was diminished, as was the formation of advanced glycation end-products (AGEs). The prevention of basement membrane glycation and thickening in various tissues indicated that acarbose treatment of diabetic animals produced beneficial effects against the development of nephropathy, neuropathy, and retinopathy. Thus, the alpha-glucosidase inhibitor acarbose may have the potential to delay or possibly prevent the development of diabetic complications.

Acarbose↗
PubMed1994

Divalent metals of myelin and their differential binding by myelin basic protein of bovine central nervous system.

Divalent metal ions are being implicated in the compaction of myelin. Levels of Cd, Co, Cu, Hg, Mn, Pb, Zn, Ca and Mg of isolated myelin of bovine central nervous system (CNS) were measured by flame atomic absorption spectrophotometry. Binding of these metal ions by isolated myelin basic protein (MBP, M(r) 18,500) of bovine CNS was concurrently assessed by centrifugal equilibrium dialysis. Metals were bound in the order of Hg > Cu > Zn > Mg > Cd > Co, exempting Mn, Pb and Ca. The results are indicative of differential metal affinity of MBP which may account for the immobilization or anchoring of MBP in myelin by zinc and other divalent metal cations.

Animals↗
PubMed1994

PET imaging of lung tumours and mediastinal lymphoma.

Positron emission tomography (PET) of the lung is evaluated regarding its clinical practicability for staging of bronchogenic carcinomas and lymphomas. Stringent quality control, optimized acquisition and reconstruction techniques are of crucial importance. An analysis of 50 PET studies for tumour (T) and lymphnode (N) staging in comparison to CT shows that PET has the highest diagnostic accuracy to classify lesions and is the most promising technique for non-invasive staging. PET cannot be the first imaging modality, but if unnecessary or invasive procedures can be avoided, the additional expense of a PET study seems justified.

Humans↗
PubMed1994

Pharmacology of alpha-glucosidase inhibition.

The development of alpha-amylase and brush-border alpha-glucosidase inhibitors is reviewed. The mode of action as well as pharmacological and pharmacodynamic properties of selected inhibitors with special regard to the most thoroughly investigated alpha-glucosidase inhibitor acarbose are discussed. Inhibition of intestinal alpha-glucosidases delays the digestion of starch and sucrose, flattens the postprandial blood glucose excursions, and thus mimics the effects of dieting on hyperglycaemia, hyperinsulinaemia and hypertriglyceridaemia. Therefore, the mechanism of alpha-glucosidase inhibition represents the pharmacological optimization of the dietary principle of delayed carbohydrate absorption. In pre-clinical studies using diabetic animals the oral administration of acarbose improved the metabolic state and reduced the blood glucose area under the curve. As a consequence, the process of non-enzymatic glycation of proteins was retarded as indicated by reduced glycated haemoglobin, glomerular basement membranes or advanced glycation end-products (AGEs) in collagen. These improved biochemical parameters correlated with beneficial effects against the development of diabetic nephropathy and neuropathy. Thus, the treatment of diabetic animals with acarbose does not only improve the metabolic state but has also the potential to delay, or possibly prevent, the development of diabetic complications.

1-Deoxynojirimycin↗
PubMed1994

[Public health measures in endoscopy--routine maintenance of endoscopes].

Flexible endoscopes that have not been properly serviced, cleaned and disinfected, are major infection risks in endoscopy. There are numerous references to this fact in literature. Manual and fully automatic servicing, cleaning and disinfecting flexible endoscopes are described and assessed in respect of patient and staff protection. The district physician (known as "Amtsarzt" = officially appointed doctor within the german Health Care and Health Insurance system) can discover hygienic deficits in endoscope maintenance when inspecting the hospitals in his district; the present article helps him to discover such deficits. The recommendations in this article are based on the guidelines issued by the Federal German Health Bureau dealing with hospital hygiene and how to prevent infections.

Cross Infection↗
PubMed1993

[Bone marrow involvement in Hodgkin's disease: MR tomography and chemical-shift imaging].

The ranking of magnetic resonance imaging (MRI) and chemical shift imaging (CSI) of the bone marrow was assessed in 30 patients in the initial staging of Hodgkin's disease or in the restaging after relapse. The results were compared with other staging procedures, especially trephine biopsies. Pathologic findings were divided into diffuse and focal lesions resulting in a better differentiation between malignant infiltrations and unspecific marrow reactions that are common in Hodgkin's disease. Diffuse changes were unspecific, a diffuse marrow infiltration could not be established in 7 patients. Focal lesions proved to be infiltrations in 6 of 7 patients; only in one case an unspecific marrow reaction was found on histology. CSI showed a pathological increase of the relative water signal in focal and diffuse marrow changes, and made no individual diagnostic contribution.

Adolescent↗
PubMed1992

Oral ifosfamide-mesna: a clinical investigation in advanced non-small-cell lung cancer.

The purpose of this study was to evaluate the toxicity and response efficacy of fixed-dose oral ifosfamide (OI)-mesna (M) in advanced, non-small-cell lung cancer (NSCLC). OI was given in four different fractionated-dose treatment schedules with a total dose per cycle of either 3.0 g/m2, 6.0 g/m2, 7.5 g/m2 or 10 g/m2 (equivalent to a daily dose of either 750 mg, 1000 mg or 1250 mg.) M was given p.o. by drinking ampules. In the 64 patients (pts) included, a total of 305 treatment cycles were administered with no evidence of severe neurotoxicity. Twenty-two pts (37%) developed mild to moderate CNS toxicity. Neither myelosuppression, alopecia, gastrointestinal toxicity nor urotoxicity were clinical problems. On schedule 2 (6 g/m2), 3 of 14 evaluable pts (21%) had partial remissions (PR), and on schedule 3 (7.5 g/m2) 4 pts (25%) showed PRs. The median duration of response was 9 months (mts) for pts on schedule 2, and 8 mts for pts on schedule 3. We conclude that OIM can easily be tolerated in the same dose usually given intravenously (7.5 g/m2/mts), when patients at high risk for developing CNS toxicity have been previously excluded from therapy. In order to reduce CNS toxicity, it is suggested that the total dose per cycle should not exceed 7.5 g/m2 (1000 mg daily) within a fractionated-dose, 14-day treatment schedule. We further conclude that the tumor response efficacy of OIM in NSCLC is comparable to the one achieved by intravenously-administered IM, whereby the total monthly OI dose should not be less than 6.0 g/m2 (750 mg daily).

Aged↗
PubMed1992

[Positron emission tomography of the thorax. The current clinical status].

The non-invasive diagnostic assessment of thoracic lesions has been greatly enhanced by the use of positron emission tomography with metabolic active radio-compounds such as fluor-18 labeled deoxyglucose. Four clinical fields of use were established: differential diagnostic evaluation of lesions (T-staging); classification of adenopathy (N-staging); therapy response monitoring; diagnostic evaluation of recurrence. The upcoming challenges for clinical use are limited availability and necessary technical and qualitative standardizations.

Carcinoma, Bronchogenic↗
PubMed1991

[Optimizing accuracy of Isosit IO composite restorations].

Using a modified technique for producing composite inlays from Isosit IO resin material resulted in an optimized accuracy of inlays primary fit. SEM evaluation of MOD composite resin inlays manufactured by this technique and inserted on extracted teeth showed that the mean thickness of the luting composite space measured less than 50 microns.

Acrylic Resins↗
PubMed1990

[Treatment of pleural metastases in an interdisciplinary concept].

A retrospective examination involved 414 patients (260 m, 154 w, mean 60 y) with pleural metastasis/pleural effusion of the following primary tumors: 37.2% bronchogenic (23.2% malignant pl. mesothelioma), 14.5% breast, 8.7% adeno-ca (unknown primary) 2.4% gastrointestinal, 2.2% uterus/ovar, and 11.8% others. Thoracoscopy with histologic confirmation played a central role in our diagnostic procedures in 97% of the cases. Malignancy was defined by CEA (less than 5 mg/ml) (71.9%) and cytology (76.9%) in 90.4%. Our strategy had the following success rate: desiccation by pleural drainage (greater than 26 Charr) alone 74%, in combination with pleurodesis 81%, pleurectomy/decortication 95%, and extended pleuropneumonectomy (in 80% mesothelioma) 96%.

Combined Modality Therapy↗
PubMed1990

[Bicarbonate instead of lactate buffered substitution solution for continuous hemofiltration in intensive care].

The substitution fluids applied in continuous haemofiltration contain 40 mmol/l of lactate. This is unphysiological, since administration of large amounts of lactate lowers the phosphorylation potential and increases catabolism. With bicarbonate-buffered fluid three problems may arise: 1. Precipitation of calcium carbonate and magnesium carbonate; 2. pH is usually 8.4; 3. evaporation of CO2 increases pH. To solve these problems we applied a two-component system consisting of a glass bottle with 160 ml sodium bicarbonate 8.4% and a bag with 4.5 l of acidic solution. Prior to use, the bicarbonate was infused into the bag. The values of Ca++, Mg++, bicarbonate, and pH in this final substitution solution were constant during a 24 hr period after mixing. Precipitation of Ca++ and Mg++ carbonate was prevented by 3 mmol/l of lactic acid in the solution. The pH was 7.37. Evaporation of CO2 was prevented by bags made of special plastic sheeting. The solution was then applied in 7 intensive-care patients suffering from acute renal failure treated by continuous arteriovenous haemofiltration. No side effects of the solution were observed during six days of treatment. The values of Ca++, bicarbonate, pH, and pCO2 remained constant under clinical routine conditions. Hence, bicarbonate-buffered substitution solution is recommended for continuous haemofiltration. Continuous haemofiltration is now also available for patients with impaired liver function and increased lactate levels.

Acid-Base Equilibrium↗
PubMed1987

Efficacy of beta-diketonato complexes of titanium, zirconium, and hafnium against chemically induced autochthonous colonic tumors in rats.

Bis-beta-diketonato complexes of titanium, zirconium, and hafnium were tested against autochthonous colorectal tumors in rats. The model was found to reflect the clinical situation most closely. Of the compounds tested, budotitane was the most effective in terms of decrease in tumor weight and number and in increasing the lifespan of the treated animals. The therapeutic efficiency was superior to that of 5-fluorouracil, which so far has been the drug with the best activity in patients suffering from colon cancer.

Animals↗