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Biomedical subjects

W Schulz

Publications and source records attributed to W Schulz.

At least 73 records · Page 4Linked to original sources
PubMed1987

Corticosteroid metabolism in rat kidney in vitro. IV. Subcellular, sites of 11 beta-hydroxysteroid dehydrogenase activity.

An attempt has been made to identify the subcellular localization of renal corticosteroid metabolism. Subcellular fractions were prepared by differential centrifugation, identified by marker enzymes and incubated under different conditions with corticosterone (B). The NADP+/NADPH dependent metabolism of B could be localized in the nuclear and microsomal fraction. The most prominent metabolite was 11-dehydro-B, which is formed by 11 beta-hydroxysteroid dehydrogenase (EC 1.1.1.146). Enzyme kinetic studies of this enzyme with B as substrate revealed apparent Km-values in the range of 10(-7) M for both the nuclear and microsomal fraction.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1987

Pharmacokinetics of ofloxacin in patients on haemodialysis treatment.

Serum concentrations and pharmacokinetic parameters of ofloxacin were measured in 10 patients on haemodialysis treatment. Serum half-life during the interdialytic interval was 48 hours, and during haemodialysis treatment 10 hours. The decrease in serum concentrations during a 4-hour haemodialysis was 25%. After several doses of ofloxacin, saturation of the tissues and a rediffusion of ofloxacin from the tissues during haemodialysis has to be assumed. This equalizes the rate of elimination, and the serum ofloxacin concentration did not change during the last 2 hours of haemodialysis. The negative influence of phosphate binders on the resorption of ofloxacin can be confirmed. The following ofloxacin dosage regimen is recommended in haemodialysis patients: 200 mg initially, 100 mg loading dose after the first haemodialysis, then 100 mg daily.

Adult↗
PubMed1987

Analysis of ras genes and linked viral sequences in rat hepatocarcinogenesis.

After long-term feeding of a choline-devoid diet to rats, the authors analyzed rasK, rasH, and rasN transcripts and gene structure in livers and liver tumors. They controlled their analysis by studying cell lines derived from chemically induced hepatomas. Transcripts from all three genes were elevated in all tumors, but not in the livers from which they arose. The transcript elevations may represent an effect of active cell proliferation in the tumors. Clone HiHi-3, derived from the Kirsten murine sarcoma virus, detected a large number of hybridization bands, most of which were not part of the rasK-p21 gene. Most tumors had an altered band at 2.6 kb; some had other altered bands. No alterations were seen in liver DNA, and none of the cell lines showed the 2.6 kb band. At low stringency, a rasH probe, which contains a short segment of a similar viral sequence, also detected altered bands in tumors and a single treated liver. These changes in endogenous viral sequences of the rat genome appear to be characteristic of carcinogenesis by a choline-devoid diet.

Animals↗
PubMed1987

Follow-up studies of three subtypes of acute postinfectious glomerulonephritis ascertained by renal biopsy.

Quantitative correlative investigations by means of light, immunofluorescence and electron microscopy carried out in the early phase of the disease on 58 patients (children and adults) with acute postinfectious glomerulonephritis (APGN) formed the basis of subtyping APGN into a starry sky type, a mesangial type and a garland type [Sorger et al. 1982 and 1983]. The subtypes also showed differences in the clinical picture. The garland type was of special interest since most patients had severe proteinuria. This caused us to follow-up the patients with these three subtypes (up to 10 years and 7 months). Proteinuria proved to be the most reliable follow-up parameter. A comparison of the three groups showed that proteinuria rapidly declined as a rule in the patients with the starry sky and the mesangial patterns. In the garland pattern there were also cases with a complete disappearance of proteinuria, especially in younger patients, but other patients still had a distinct proteinuria after months to years indicating a protracted or chronic course. The morphological findings of the rebiopsies correlated with the clinical courses, especially with the course of proteinuria. The three morphological subtypes are thus significant for estimating the prognosis of APGN, which is favorable as a rule in patients with the starry sky and mesangial types, but much more unfavorable in patients with the garland type. Even if fewer cases with demonstrated streptococcal etiology were found in the garland pattern group, i.e., among patients with the most uncertain prognosis, than in the remaining groups, these differences were not statistically significant. Therefore, our investigations do not provide any indications that different etiological factors are responsible for the three subtypes. The individual immune response of the host body is likely to be very much more decisive.

Acute Disease↗
PubMed1987

[Aneurysm surgery in relation to secondary intracranial findings].

In 116 patients operated on because of aneurysms we found 125 aneurysms, one convexity meningioma, and one A. V. supratentorial angioma. In 9 patients (8%) more than one aneurysm were found. In 8 patients there were double aneurysms and on one case 4 aneurysms, 18 of these 20 aneurysms were clipped. If these were situated on the same side they were treated simultaneously. If they were situated on two sides, the aneurysms were clipped in two surgical interventions. In 2 patients one of the two aneurysms remained untreated. Two interventions were also carried out for the combination aneurysm/tumor. After clipping the aneurysm, the meningioma was removed after an appropriate interval.

Brain Neoplasms↗
PubMed1986

[Ofloxacin treatment in nephrologic problem patients with various degrees of chronic renal failure (including dialysis treatment). Preliminary results].

Treatment with ofloxacin in 15 patients with chronic renal failure at different stages is reported with respect to patients undergoing hemodialysis treatment. We noticed the elimination of gram-negative and gram-positive strains, even in patients who had extensive but unsuccessful antimicrobial pretreatment. In the reported collective an interaction between ofloxacin and phosphate-binders on aluminum hydroxide basis has to be considered in the individual cases. The dosage of ofloxacin has to be adapted to the stage of chronic renal failure.

Adult↗
PubMed1986

Behaviour of cell physiological and biochemical indicators of maturation and aging of red blood cells in density fractionated red blood cells during a bleeding anaemia of the rabbit.

Changes of the density, MCV, MCHC, RNA-concentration and the activities of the enzyme G6PD and ASAT due to maturation and aging of rbc were investigated by repeated density gradient separation of these cells during a bleeding anaemia of the rabbit. The mean density of reticulocytes and erythrocytes decreases during the course of the anaemia by 14 and 10 g/l respectively. The difference between the density of both cell types increases from 3 to 6 to 12 g/l during the anaemia. Maturation and aging of rbc are characterized by an increase of the MCHC from 200 to 350 g/l cells and the decrease of MCV by 10-25%. The RNA concentration and the ASAT activity show an almost parallel behaviour in cells of different densities during the anaemia. Remarkable differences are observed between the ASAT activity and the G6PD activity: The G6PD activity decreases mainly during the aging process and almost not during the maturation, while the ASAT activity falls constantly during maturation and aging. As observed in former studies we could distinguish and isolate 4 characteristic populations of reticulocytes in certain density fractions during the anaemia: Normal young reticulocytes, line 2 reticulocytes, megaloreticulocytes and reticulocytes of high density.

Anemia↗
PubMed1986

[Effects of intracoronary nitroglycerin administration on poststenotic vascular diameter before and following transluminal coronary angioplasty].

Percutaneous transluminal coronary angioplasty (PTCA = TCA) was performed in 38 patients with coronary single vessel disease. Coronary angiograms were analysed to detect the influence of mechanical as well as nitroglycerin-induced dilation on organic stenoses, prestenotic and poststenotic coronary segments and non-stenosed reference vessels. 28 patients (group I) were evaluated retrospectively. Bolus injection of 0.5 mg of nitroglycerin (NTG) was followed by an increase in all measured segments: prestenotic segments +15.4%, stenoses +17.9%, poststenotic segments +39.3%, reference segment of a nonstenotic vessel +29.9% above control value before NTG. Subsequent mechanic dilation of stenosis by 108.3% resulted in no further significant increase of poststenotic diameters (+42.6% above control value), while diameters of reference vessels decreased (+9.7% above control value). In order to demonstrate whether this behaviour was due to a loss of NTG activity at the end of TCA, we attempted to reinduce vasodilation in another 10 patients (group II) by a second intracoronary bolus injection of 0.5 mg NTG. In these patients NTG injection before TCA resulted in an increase in poststenotic diameters as well as in reference vessels (21.2% and 14.0% respectively above control value). At the end of TCA an increase in the poststenotic diameter could be found to 22.1% above control value, while diameters of reference vessels had markedly decreased (4.1% above control value). The second injection of NTG resulted in an increase of poststenotic as well as reference segments (39.3% and 17.4% respectively above control value).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1986

[Cell proliferation and glial fibrillary acidic protein in brain tumors].

The results of histoautoradiographic and immunohistochemical studies of biopsy specimens of 15 brain tumours are reported. The specimens were labeled with 3H-thymidine using an in vitro technique. Meningiomas, oligodendrogliomas and well differentiated astrocytomas showed a median S-phase fraction of about 1%. In contrast, the labeling indices of 4 from 7 anaplastic astrocytomas were higher (2.1, 3.0, 3.5, 11.4). With increasing degree of malignancy the proliferative heterogeneity of the tumours increases. In every glioma varying amounts of glial fibrillary acidic protein (GFAP) were detected immunohistochemically (PAP technique). In 3 high-grade gliomas (2 glioblastomas, 1 anaplastic astrocytoma) an inverse relation of the investigated parameters (high S-phase fraction, low GFAP expression) was found. An exact prediction on biological behaviour of an individual tumour by GFAP detection immunohistochemically is not possible, because a high GFAP content can be detected also in some malignant tumours. However, the 3H-thymidine labeling indices of viable parts of the tumours, probably reflecting the growth fraction seem to be clinically important parameters, especially in respect to the prognosis.

Adolescent↗
PubMed1986

[A simple aid for the localization of intracranial tumors in cerebral computer tomography].

The exact localizing co-ordination of small intracranial, space-occupying processes is sometimes difficult. As a simple aid for exact localization of such processes a "rod headband" is presented, which consists of a leather strap with exchangeable plastic rods and can be put on the patient's forehead for a CT examination. The artifact-free representation of the little rods in the axial CT layers makes it possible to localize intracranial processes more exactly. Until now, the "rod headband" has been used for ten patients with the following indications: Needle biopsies of intracranial space-occupying processes, cerebral abscess punctures, haematoma punctures, and as a pre-operative localization aid for intracranial tumours.

Brain Abscess↗
PubMed1986

[Social environment of alcoholic patients after clinic discharge and its effect on treatment success].

The study concerns the social situation of alcoholics after a 3- to 6-weeks in-patient withdrawals. As central question appears that for the influence of the social situation on treatment outcome. We distinguish between the life-subjects work and occupation, partnership, spare time, living situation, financial situation and official and judicial problems. In order to register the treatment outcome we had catamnestic interviews 3 months after the patients left the hospital. The sample consist of 48 patients. The most important result is: the more disadvantageous the social situation, the patients relapse. Having an employment, a good partnership and enough income is must important for the treatment outcome.

Adult↗
PubMed1986

[Questions from clinicians to the radiologist regarding the diagnosis of metabolic bone diseases].

Macromorphological X-ray findings in metabolic bone disease can establish the diagnosis only in advanced stages. Micromorphological X-ray diagnostic procedures will support the diagnosis even at an early stage. Measurement of minerals is an adjuvant method for early diagnosis and survey of therapy in metabolic bone diseases. The measurement of calcium phosphate metabolism and description of bone histology (histomorphometry) and radiological morphology enables the type and stage of osteopathy to be diagnosed. The combination of diagnostic methods is helpful in distinguishing bone diseases with increased turnover, impaired bone modelling and absorption, disturbed mineralization and ectopic calcification. Within the metabolic osteopathies, osteoporosis is gaining importance as a socioeconomic problem; therefore, early diagnosis and treatment are of relevance. Hyper-, hypoparathyroidism and osteoidosis are curable if early diagnosed.

Arthrography↗
PubMed1986

Pharmacokinetic of topical cyclosporin A in the rabbit eye.

3H labelled cyclosporin A (CS-A) eye drops (2% in castor oil) were applied in rabbits. When a single drop of 10 microliters was given CS-A reached a maximal concentration of 900-1400 ng/ml in the cornea 6 hr after application and then slowly decreased. A substantial level of 600-900 ng/ml was still present after 48 hr. When corneas were analysed for their cellular compartments, 67% of CS-A was found in the epithelium, 25% in the stroma (probably in keratocytes), and 8% in the endothelium. In corneas denervated by circular keratotomy, slightly reduced concentrations were found after surgery, the reduction was not therapeutically significant. Using the HPLC method a significant corneal metabolism of CS-A could be excluded. Scleral concentrations of CS-A as high as 180 ng/ml were found. Concentrations of CS-A in aqueous humor, lens, vitreous body and uvea/retina were below the therapeutic range.

Animals↗
PubMed1985

Relation of antianginal efficacy of nifedipine to degree of coronary arterial narrowing and to presence of coronary collateral vessels.

Thirty-six patients with chronic stable angina pectoris or with stable and vasospastic components of angina pectoris were classified by coronary arteriographic findings into 4 groups. Patients in group A had a single stenotic coronary artery; patients in groups B, C and D had occluded arteries, but these arteries had been collateralized to varying degrees, and an epicardial coronary steal phenomenon was possible. All patients underwent multiple exercise tests before and after randomized, double-blind, crossover treatment with 20 mg of nifedipine, 20 mg of isosorbide dinitrate, a combination of both, and placebo. Maximal and mean ST-segment depression, occurrence of angina pectoris and heart rate were evaluated. After nifedipine treatment, mean ischemic ST-segment depression was reduced 21% in group A (p less than 0.05), but was not significantly altered in the other groups (group B, 2% decrease; group C, 10% increase; group D, 3% decrease). However, isosorbide dinitrate reduced ST-segment depression significantly in all groups (group A, 29%, p less than 0.001; group B, 18%, p less than 0.01; group C, 19%, p less than 0.05; group D, 33%, p less than 0.05). The combination with nifedipine did not further improve the effect of isosorbide dinitrate. Maximal ST-segment depression and angina pectoris paralleled the changes in mean ST depression during the different medications. Heart rate at rest was not significantly changed after nifedipine treatment in any group, but increased significantly after isosorbide dinitrate treatment in groups B and C (group B, 12%, p less than 0.01; group C, 9%, p less than 0.05); heart rate during exercise did not differ significantly in any group or after any form of medication from placebo.

Adult↗
PubMed1985

The distribution of liver metastases from colonic cancer. A quantitative postmortem study.

54 livers of patients with colonic cancer were investigated in a postmortem study. 26 livers contained metastases from colon carcinoma. Assessment of the number, size and location of metastases was made. The possible interdependence of the site of the colonic primary and the location of its secondaries in the liver was examined. Results suggest an approximately homogeneous distribution of metastases from colonic cancer in the hepatic parenchyma, irrespective of the location of the primary tumour.

Colonic Neoplasms↗
PubMed1985

Active and passive changes in coronary diameter after vasodilation with SIN-1, the active metabolite of molsidomine.

The vasodilating effects of intracoronary injections of 0.4 mg of SIN-1, the active metabolite of molsidomine, on epicardial coronary arteries and coronary stenoses were evaluated in 14 patients with coronary artery disease in a double-blind, randomized fashion vs placebo. Nine additional patients with well defined coronary stenoses received 0.4 mg of SIN-1 as well. Diameter changes of nonstenotic coronary arteries in proximal, medial, and distal coronary segments as well as changes of the residual luminal diameters within coronary stenoses were determined before (K), immediately after (M1), and 10 minutes after (M2) intracoronary administration of SIN-1. Aortic pressures and heart rate were monitored continuously. After administration of SIN-1, the diameters of nonstenotic coronary arteries increased in proximal segments by 9.4% (M1) and 11.7% (M2), in medial segments by 17.9% (M1) and 17.6% (M2), and in distal segments by 25.6% (M1) and 28.8% (M2). Within coronary stenoses the residual luminal diameters showed mean increases of 31.5% (M1) and 48.3% (M2). Placebo administration did not alter coronary diameters significantly. Aortic pressure and heart rate did not change after administration of SIN-1 or placebo. SIN-1 effectively dilates nonstenotic and stenotic coronary segments, as do nitrates and calcium channel blockers. By intracoronary injections, the direct effects on coronary vessels can be evaluated without interference with systemic effects. The increase in the residual luminal diameters within dynamic coronary stenoses after administration of SIN-1 is probably an important antianginal mechanism also for molsidomine.

Coronary Angiography↗