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Biomedical subjects

W Müller

Publications and source records attributed to W Müller.

At least 775 records · Page 43Linked to original sources
PubMed1980

[Renal side effects of treatment with cyclosporin A in rheumatoid arthritis and after bone marrow transplantation].

Renal function was studied prospectively in 6 patients with rheumatoid arthritis and non-prospectively in 5 patients after bone marrow transplantation. Both groups were treated with cyclosporin A. Functionally and histologically the results suggest tubulotoxicity of cyclosporin A which seems to be dose-related and reversible. Also found in the urine of these patients were yellow, as yet undescribed crystalline bodies often included in casts.

Aged↗
PubMed1980

Differentiation of the epithelium of the human hard palate.

The normal epithelium of the human hard palate is a keratinizing integument. There is considerable, mostly stereological, evidence that the differentiation and the type of keratinization in this epithelium differ from those of the epidermis. The objective of the present study was to correlate a systematic light- and electron microscopic description of this epithelium with stereological data, placing particular emphasis on differentiation phenomena. Twenty punch biopsies of 9 to 16 year-old females were studied. The observations show that (1) spinous cells are elongated or approximately isodiametrical in ridge regions and, above the level of the connective tissue papillae become disc-shaped in the upper stratum spinosum; (2) a prominent electron-lucent zone poor in organelles occurs at the cell periphery of basal and spinous cells; (3) the structure of desmosomes changes in the upper stratum granulosum with the distance between the intradesmosomal cytophasmic membranes gradually increasing from the basal to the granular layer; (4) single and composite keratohyalin granules display a different shape (i.e., spherical or irregular, patch-like) varying to a higher degree among individual cells than within a single cell of the stratum granulosum; (5) transitional cells can be observed; (6) the predominantly anuclear cells of the stratum corneum vary in their homogeneity and density, most cornefied cells revealing a find-granular keratin pattern lacking the filament profiles common in the epidermis. Consequently, while the type of keratinization appears to be independent from the type of keratohyalin granules produced, the differentiation process and the type of the terminally differentiated cells of the hard-palate epithelium differ from those of the epidermis.

Adolescent↗
PubMed1980

Cell junctions with funnels in the olfactory mucosa of frogs (Rana temporaria L.).

A characteristic structure in the apical junctional belt of the olfactory epithelium in Rana temporaria is visible in freeze-fracture preparations. This structure is described as a "funnel with channel across the junctional belt". It is supposed to represent a possible way for "discarding used molecules" after stimulation, and to allow the stimulation of free nerve endings in the depth of olfactory epithelia.

Animals↗
PubMed1980

Histochemical methods for the further characterisation of the tumourettes of the posterior lobe of the pituitary.

The granular cell tumourettes of the posterior lobe of the pituitary possess neuraminic acid containing carbohydrate. After removal of neuraminic acid with neuraminidase and exposure to FITC (Fluorescein isothiocyanate) labelled peanut agglutinin (Arachis hypogaea) (PNA), intracellular receptor structures could be demonstrated. The significance of the findings is discussed.

Histocytochemistry↗
PubMed1980

Milieu-specific vascular changes in malignant brain tumours.

Changes in blood-vessels, in configuration similar to arteriosclerosis, are found in malignant gliomas, especially in glioblastomas, as well as in metastases of carcinomas. Since analogous changes in vessel walls were not seen in primary tumours pertaining to cerebral metastases and in metastases of the body, this can obviously be considered as a phenomenon milieu-specific in nature. It is reasoned that this phenomenon can essentially be attributed to decomposition of medullary substance and influx of resulting disintegration products (lipids and cholesterol) into the vessel walls.

Brain Neoplasms↗
PubMed1980

Lectin binding sites in the choroid plexus and choroid plexus papillomas.

The surface of the cells of the normal choroid plexus and of the plexus papillomas is coated by sialomucopolysaccharides, containing substances which are positively stained with the colloidal iron (Hale-) reaction. After pretreatment with neuraminidase sialic acid is removed rendering the membrane negative to the Hale reaction. Using FITC- or rhodamine-labelled PNA (Arachis hypogaea) and RCA (Rhicinus communis) lectins specific receptors are demonstrable. The identity of these distinct oligosaccharides containing receptors with the Thomsen-Friedenreich antigens suggests the possibility of an immunologic significance, e. g. in bacterial or viral infections of the brain. The application of histochemical techniques seem suitable to clarify the differential-diagnosis between choroid plexus papillomas on the one hand and metastasis of carcinoma and papillary ependymomas on the other hand.

Adolescent↗
PubMed1980

Evidence that C1q, a subcomponent of the first component of complement, is an Fc receptor of peritoneal and alveolar macrophages.

Guinea pig peritoneal macrophages were cultured for 24 h in the presence of two inhibitors of the biosynthesis of collagen-like molecules such as C1q : 10(-3) M 3,4-dehydroproline or 10(-4) M 2,2'-dipyridyl. Their Fc-receptor activity was measured by rosette formation, using sheep erythrocytes (E) coated with rabbit anti-sheep IgG (EAIgG). The Fc-receptor activity was decreased by 40 to 70% of control cultures depending on the amount of IgG on the E. The activity of a second receptor on the macrophages, mediating the binding of C3b coated E, was not altered by this treatment. Rat alveolar macrophages were depleted of their Fc-receptor activity by pronase treatment (1.5 mg/ml) in the presence of 2,2'-dipyridyl. After washing the cells, the EAIgG-binding activity was restored to about half of the initial level within 2 h. With 2,2'-dipyridyl also present during the second incubation, the re-expression of the Fc-receptor activity was suppressed further. Preincubation of guinea pig peritoneal macrophages with anti-C1q-F(ab')2 for 45 min at 37 degrees C caused a dose-dependent reduction of the Fc receptor activity, but not C3b receptor activity. These results support our hypothesis that C1q synthesized and secreted by macrophages serves as an Fc-receptor in the membrane during the secretion.

2,2'-Dipyridyl↗
PubMed1980

Stereology of inflammatory connective tissue infiltrates in oral mucosa.

In the present summary, different approaches to analyse inflammatory connective tissue infiltrates are reviewed. The most appropriate model for this purpose was found to be the stereological analysis at the electron microscopic level. This method furnishes data comparable with results obtained by other quantifying methods, such as biochemical analysis. The presently used methodology for the analysis of diseased portions of oral mucous membranes, as well as selected results thereof are described. The usefulness and reliability of the method are discussed and future developments are suggested.

Animals↗
PubMed1980

An established routine method for differential staining of epoxy-embedded tissue sections.

A method is described for staining semithin sections of epoxy-embedded cells and tissues. PAS-positive structures are specifically demonstrated by a red staining providing a vivid contrast to the other tissue components differentially stained in shades of blue, using methylene blue/azure II. Typical staining conditions for 1 to 2 micron thick Epon sections include 30 min oxidation with 5% periodic acid at 50 degrees C, 30 min incubation with Shiff's reagent at 50 degrees C, 20 min counter-staining with 0.5% methylene blue/0.5% azure II in 0.5% aqueous borax solution at room temperature. For 10 years, this method has provided excellent differential staining with a variety of tissues. Stained sections showed no signs of fading during this period of time. Therefore, this procedure is recommended as a simple method of staining semithin sections both for tissue orientation in electron microscopy and for brillant representation of cells and tissues, required for microphotography in color or black-and-white.

Animals↗
PubMed1980

[Chemical and biological properties of revertants derived from a Salmonella typhimurium Rd1-mutant (author's transl)].

Two S-form-revertant strains were isolated from a S. typhimurium Rd1 culture on account of their phage resistance. In microbiological and serological (O-agglutination) characterization - as well as in stability tests (agglutination in auramin and saline and heating at 100 degrees C) - the behaviour of the two strains was the same as that of the wild type. The two strains were found to be indistinguishable from the wild type strain also with respect to the chemical composition of their lipopolysaccharides. Thus the amount and proportion of fatty acids and sugar residues as well as the number of repeating units in the O-chain were all identical. In contrast, the isolated revertants were similar to the Rd1 mutant with respect to their auxotrophic markers methionine and tryptophane, to the absence of flagella as well as to the reduced content of cyclopropane fatty acids (C17, C19). Protein analysis revealed no significant qualitative or quantitative differences between the wild type strain and the two revertants with respect to the major proteins of their outer membranes. The sensitivity of the revertants to crystal violet, erythromycin and rifamycin SV was intermediate between the wild type and the Rd1 mutant. Their temperature maximum in nutrient broth was 43 degrees C, the retardation in growth at this temperature corresponding to that of the Rd1 mutant. At 37 degrees C, however, the growth rate of the revertants was identical to that of the wild-type, while that of the Rd1 mutant was slower. Addition of sodium chloride to the growth medium rendered the temperature dependent behaviour of the mutants and revertants similar to that of the wild type. Studies in NMRI mice revealed that the revertants, also with regard to their virulence, occupy an intermediate position between the mutant and the wild type. Nevertheless their ability to afford protection to Salmonella typhimurium infection following active immunization with acetone killed cells was as high as that of the wild type. The results show that the biologic behaviour of S. typhimurium is determined by the type of lipopolysaccharide it contains but also to a large extent by other cell-wall constituents.

Drug Resistance, Microbial↗