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Biomedical subjects

M Neumann

Publications and source records attributed to M Neumann.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Comparative studies of the acid-base status in venous, capillary and mixed blood from the ear of the dog].

Ten experimental dogs were tested in twelve experimental arrangements, with a view to finding out the extent to which results of acid-base determination or blood gas analysis could be significantly affected by induced hyperaemia of the ear or by the choice of a site for blood collection, including puncture of an ear vein. No difference was secured. Hence, ear vein puncture may be used to collect so-called capillary blood. Reference is made to the author's own values for use as criteria.

Acid-Base Equilibrium↗
PubMed1988

Community psychiatric rehabilitation in Israel.

This paper describes the development of community-based rehabilitation services for persons with mental illness in Israel. It describes current provision for occupational, social and residential programs. It is argued that developments in all of these spheres have been both slow and piecemeal, and that they have been influenced unduly by models imported from psychiatric hospitals. The authors conclude that more adequate provision is needed, and that this should be more attuned to the philosophy and objectives of community psychiatry.

Community Mental Health Services↗
PubMed1988

New bacteriophages active on strains of Hyphomicrobium.

Fifty-five lytic bacteriophages isolated from water and soil samples were active on many strains of the genus Hyphomicrobium. The optimal isolation procedure was an adsorption method in which samples from a habitat similar to that of the respective host bacterium were used as the phage inoculum. According to the morphology and nucleic acid type these bacteriophages belonged to different families: Myoviridae (type A1: five phages); Styloviridae (type B1: 33 phages; type B2: eight phages) and Podoviridae (type C1: nine phages). The Styloviridae (type B1) appeared in two morphological variants (tails flexible or rigid). All phages investigated were specific for the genus Hyphomicrobium and were unable to lyse members of other genera of hyphal, budding bacteria (e.g. Hyphomonas, Pedomicrobium, genus D, genus T). The host specificity of 42 phages was tested with 156 Hyphomicrobium strains: 122 strains were lysed by at least one of these phages, but 34 Hyphomicrobium strains were not susceptible. Morphotype B1 phages with identical morphology could be distinguished according to their host-range properties on prophage-containing Hyphomicrobium strains. With regard to differences in morphology and host range, 25 phages were selected for more detailed investigations. From these phages DNA was isolated; the melting transition midpoints (Tm) ranged from 67 to 93 degrees C. The upper and higher values suggested the presence of DNA modifications. Six different adsorption patterns could be distinguished among the Hyphomicrobium phages. Preferred attachment sites were the proximal pole of the mother cell, the hyphal tip, the distal pole of the bud, and the distal pole of the swarmer cell.

Bacteria↗
PubMed1988

[Lung function findings in workers in the rubber industry].

Chronic obstructive lung disease is common in workers in the rubber industry. Because of the close relation between hyperreactivity of the airways (HR) and the annual decline in FEV1 we measured HR in 89 healthy workers of a big rubber plant. Three groups were formed (control, latex production, rubber production). The prevalence of HR was that of a healthy general population (PC 20 FEV1 less than 0.2% Methacholin in 3 cases). In the lower Methacholin range a separation between all groups was possible.

Adult↗
PubMed1987

Characterization of actinomycin-D-resistant CHO cell lines exhibiting a multidrug-resistance phenotype and amplified DNA sequences.

Actinomycin D (DACT)-resistant sublines of the Chinese hamster ovary cell line CHO-K1 were selected in vitro. Sublines were derived which expressed 5.2-fold (CHO 15DACT) and 35.8-fold (CHO 100DACT) resistance to DACT. The CHO 100DACT subline displayed marked cross-resistance to bleomycin, adriamycin, daunomycin, vinblastine, vincristine, VP 16 and VM 26. No cross-resistance was found to cisplatin or methotrexate. The resistant cells exhibited enhanced (collateral) sensitivity to prednisolone. Combination of prednisolone with vincristine resulted in a pronounced synergistic effect on sensitive cells, whereas in resistant cells the combined effect of both drugs was merely additive. Resistant cells, viably stained with the DNA-specific dye Hoechst 33342, exhibited decreased fluorescence intensities compared to parental cells. In contrast to sensitive cells the resistant sublines did not accumulate the mitochondria-specific dye rhodamine 123. Co-incubation with verapamil, however, effectively enhanced accumulation of the dye. The potential diagnostic value of these fluorescent compounds as marker dyes for the multidrug-resistance phenotype is discussed. Non-toxic doses of verapamil almost completely reversed the resistance to various drugs in CHO 100DACT cells. Specific DNA sequences were amplified in resistant cells, and the increase in resistance was paralleled by a concomitant increase in the copy number of these sequences, suggesting that the corresponding gene may be functionally linked to the multidrug-resistance phenotype.

Animals↗
PubMed1987

Cell length to diameter relation of rat fetal radial glia--does impaired K+ transport capacity of long thin cells cause their perinatal transformation into multipolar astrocytes?

In thick sections of Golgi-impregnated late fetal rat brains, radial glial cells were measured for both length and diameter of their main (basal) processes. The process diameter was found to decrease proportionally to the square root of cell length; thus, the cytoplasm volume remained fairly constant for cells in the range of lengths studied (100-2500 microns). The measured data were used for calculation of the cell's space constant lambda in order to estimate their capability to carry spatial buffering K+ currents. These calculations show that long and slender cells are unable to perform sufficient K+ clearance by such currents. This supports the hypothesis that perinatally when the maturing neurons release enhanced K+ during electrical activity, such long thin cells are subject to long-lasting depolarizations and, thereby, forced to undergo mitotic cell division transforming them into multipolar astrocytes.

Animals↗
PubMed1986

Interdependency of attitudes, diagnostic assessments and therapeutic recommendations of medical students towards mental patients.

Interdependencies of attitudes towards vignettes of mentally ill patients and the professional approach of medical students measured by means of diagnostic assessments and therapeutic distance were studied. First, the findings indicate that the attitudes towards the vignettes depended on the behavioral characteristics of each patient presented in the vignettes. Thus, the levels on four attitudinal subscales were different for each of the patients. Second, the two variables of the professional approach of the students towards the patients, i.e., the diagnostic assessment and the therapeutic distance, were dependent on the attitudes towards the patients. The findings indicate that the more disturbed a patient is, and the less he is diagnosed as mentally ill, the more he is rejected from treatment, and the more negative the students' attitudes are towards him.

Adult↗
PubMed1985

Morphological variability, lectin binding and Na+,K+-activated adenosine triphosphatase activity of isolated Müller (glial) cells from the rabbit retina.

Rabbit retinal Müller cells were isolated by means of papaine and mechanical dissociation. These cells were shown to have a well preserved morphology and to preserve viability for many hours. Intense wheat germ agglutinin binding occurs on the photoreceptor side of Müller cells, especially in the microvillous region. Rabbit retinal Müller cells have a Na+,K+-activated adenosine triphosphatase activity in the same order of magnitude as brain astroglial cells.

Animals↗
PubMed1985

Gradient separation of granulocytic progenitor cells (CFUc) from human blood mononuclear leukocytes.

Two different density-gradient techniques were compared for separation of human blood-derived granulocyte-macrophage progenitor cells (CFUc) from immunocompetent cells using albumin or Percoll as gradient media. Mean CFUc enrichment by means of discontinuous albumin gradient was twofold, whereas Percoll gradients yielded about 20- to 40-fold enrichment of CFUc in relation to lymphocytes. The pH of gradient media proved to have a major influence on separation quality. Based on these results and the development of a new density-separation technique in a 600-ml plastic bag, replacing customary Ficoll-Hypaque gradients, a method for large-scale purification of CFUc from leukapheresis-derived leukocytes has been constructed, working in a closed, sterile system. About 11 X 10(9) mononuclear cells containing 6 X 10(5) CFUc could be processed within 10 h. Lymphocytes were reduced to less than 1% of their initial number, and an average of about 50% of the original CFUc could be recovered.

Cell Separation↗