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Biomedical subjects

R Meier

Publications and source records attributed to R Meier.

At least 181 records · Page 10Linked to original sources
PubMed1987

Acute infectious diarrhea.

This review deals with the epidemiology of acute infectious diarrhea mainly with regard to third world countries. It also reports on advances in modern case management, oral rehydration, antibiotic therapy and problems of host resistance and transmission.

Acute Disease↗
PubMed1986

Molecular cloning of bovine and chick nerve growth factor (NGF): delineation of conserved and unconserved domains and their relationship to the biological activity and antigenicity of NGF.

Previous experiments with purified mouse and bovine nerve growth factor (NGF) have shown that the biological activities of these two NGFs are identical, whereas the immunological cross-reactivity of antibodies produced against the two NGF molecules is very limited. This observation, together with the fact that antibodies to mouse NGF do not affect the development of sympathetic and sensory neurons in chick embryos, suggests that the domain of the NGF molecules responsible for the biological action has been highly conserved during evolution, whereas other domains determining the immunological properties were under less rigorous evolutionary constraint. The nucleotide sequences of bovine and chick NGF were determined from a cDNA clone prepared from mRNA of bovine seminal vesicles and from cloned chick genomic DNA, and the amino acid sequences deduced therefrom were compared with the available sequences of mouse and human NGF. All six cysteine residues were conserved in agreement with the previous finding that the biological activity of NGF is conformation-dependent requiring intact disulfide bridges. Amino acid changes are mainly confined to hydrophilic regions expected to be potential antigenic determinants, thus providing an explanation for the poor immunological cross-reactivities between the different NGFs. One single hydrophilic region is conserved in all NGFs and this region could be involved in the biological activity. The carboxy termini of bovine and chick NGF differ from that of mouse NGF, the changes in the amino acid sequences suggest that chick and bovine NGF are probably not processed by the gamma-subunit and that no 7S complex can be formed as in the mouse submandibular gland.

Amino Acid Sequence↗
PubMed1985

[Health and disease: concepts, values amd practices in everyday life].

The article deals with the health and illness concepts and values of different social groups. The results are based on a survey of 443 persons, 20 to 65 years old, living in the German or French speaking part of Switzerland. The health and illness concepts and values are analyzed and their impact on the everyday health and illness practices is shown. Based on these results some conclusions concerning health education programs are drawn.

Adult↗
PubMed1984

Comparative freeze-fracture study of perialgal and digestive vacuoles in Paramecium bursaria.

In the endosymbiotic unit of Paramecium bursaria (Ciliata) and Chlorella sp. (Chlorophyceae) algae are enclosed individually in perialgal vacuoles, which do not show acid phosphatase activity and thus differ from digestive vacuoles. Both types of vacuoles have been studied by freeze-fracture. Perialgal vacuoles are nearly spherical; their membrane always fits tightly to the algal surface. The vacuole size and shape do not vary much. During division of the algal cell into four autospores the vacuole diameter only doubles. After autospore formation the vacuole invaginates around the algal daughter cells and divides. Newly formed perialgal vacuoles remain in intimate contact and exhibit characteristic attachment zones before final separation. The two fracture faces of perialgal vacuole membranes are homogeneously covered with intramembranous particles (IMPs) but rarely show signs of vesicles pinching off or fusing with the membrane, except during vacuole division. The P-faces bear more IMPs (3164 +/- 625 IMP/micron 2) than the E-faces (654 +/- 208 IMP/micron 2). The range of IMP density on both faces is enormous, suggesting that the membrane is not static. Membrane changes are supposed to occur simultaneously with the enlargement of the vacuole and to be caused by fusion with cytoplasmic vesicles, as the fractured necks on vacuole membranes may indicate. Digestive vacuoles in P. bursaria show significant variations in size, shape, membrane topography and IMP density, as well as signs of endocytic activity. Different vacuole populations are present in P. bursaria according to different feeding conditions: ciliates fed for a long time have small vacuoles with few IMPs (322 +/- 198 IMP/micron 2 on the E-faces, 1438 +/- 458 IMP/micron 2 on the P-faces), which are probably condensed digestive vacuoles, whereas organisms fed for a short time have larger vacuoles with highly particulate faces (680 +/- 282 IMP/micron 2 on the E-faces, 2701 +/- 503 IMP/micron 2 on the P-faces) and thus are supposed to be older vacuoles. The digestive vacuole membrane changes continuously. Compared to digestive vacuoles perialgal vacuoles are characterized by small size combined with high IMP density on the two fracture faces. Their IMP densities resemble those of old digestive vacuole membranes. However, it would be premature to conclude that membranes of perialgal and old digestive vacuoles are identical. Membranes of old digestive vacuoles are mainly derived from lysosomal material, which presumably does not contribute to the formation of perialgal vacuole membranes as is indicated by the small vacuole diameter; fusion with lysosomes would considerably enlarge it.(ABSTRACT TRUNCATED AT 400 WORDS)

Chlorella↗
PubMed1983

Alinidine in angina.

Alinidine--N-allyl-clonidine--reduces heart rate without blocking beta adrenoreceptors. It may be used in patients with angina without inducing the adverse effects of beta-adrenergic blockers. We therefore evaluated alinidine efficacy in patients with angiographically proven coronary artery disease and stable angina during a 10-wk placebo-controlled randomized double-blind trial. Alinidine (40 mg three times a day) reduced the number of anginal attacks and the average number of nitroglycerine capsules consumed. The double product was slightly lowered during rest but more pronounced during exercise. This effect was mainly due to decreased heart rate. The ischemic S-T segment depression was diminished. Exercise tolerance was clearly improved in six, slightly improved in two, and unchanged in four subjects.

Adult↗
PubMed1983

Intracerebral electrode implantation system. Technical note.

A new technique for deep-brain electrode implantation is described. A very flexible nontraumatic electrode guided by a central stylet and a new electrode head-fixation screw are the two unique features of this system. Electrodes can be guided precisely and their watertight fixation to the bone by means of the special screw is reliable and totally reversible. The system has been designed to fit most of the stereotaxic frames currently in use.

Electrodes, Implanted↗
PubMed1983

[Comparative methodological contribution and critical observations on the interpretation of blood group determinations of mummies and skeletal remains].

Bone samples from autopsies, recent and subfossile samples as well as skin and muscle material from non-preserved local mummies were investigated. The material was evaluated morphologically and serologically in parallel by means of the well-known absorption-test, the agglutinin-cohesion technique with deionized concentrated EDTA extracts according to Borgognini, the absorption-elution technique according to Kind with the modification proposed by Kirst & Landes, and the immunofluorescence-histology according to Lengyel. With the latter method no specific results could be obtained at all; with the absorption and the absorption-elution tests the blood-group status of autoptic compacta material could always be estimated correctly, and also with recent bone samples an acceptable phenotype distribution was found. On the contrary, with the old-historic material consisting of 39 skeletons a reverse proportionality between the morphological preservation state and the serological results was found: the more advanced the decay of the organic matrix, the more frequent was the finding of blood-group A or B; the better preserved the bony substance, the more frequent negative (= 0 ?) results were obtained. By analogy with the findings in mummy tissue, where the tracing of A and B bloodgroup substances also prevailed in cases of extensive saprophyte contamination, the postmortal infiltration of microbiological blood-group active foreign material is discussed as a possible cause of erroneous diagnoses for bones, too. The compared methods yielded different results on the same bone in some cases, and also with the, according to our experiences, most suitable absorption-elution method contradictory blood-group findings were achieved with different bones of the same skeleton occasionally. In light of these results it seems possible to detect blood-group substances of the ABO system in bone material only under protective storage conditions, as tomb funeral, ossuaries, or reliquaries after centuries and with acceptable error quote; serological findings on subfossile materials must be valued with greatest reservation, and critical restraint should be recommended especially against the method of approach.

Autopsy↗
PubMed1983

[Comparative studies of gelatin and cellulose ester membrane filters for their suitability in determining the microorganism count in the air].

Filtration is one of the classical methods for the determination of the microbial content of the air or the number of microbe-bearing particles in the ambient air. Hereby, the opinion prevails that gelatin foam filters yield better results than filters made of cellulose esters. Since gelatin filters are themselves by no means free from disadvantages, several tests were carried out under the conditions encounted in practice in two packaging rooms used for pharmaceutical preparations. The objective was to ascertain whether the customary cellulose ester filters really are less suitable for determination of the microbial content of the air than the filters made of soluble gelatin. Based on the results of various preliminary experiments, gamma-irradiated filters of cellulose nitrate, with a pore size of 0,45 micron, were selected from a range of tested membrane filters (Tables 1,2,4-6 and Fig. 1) and compared directly with the gelatin filters. The statistical evaluation of these tests showed that, under the chosen experimental conditions, both filters yielded the same count of organisms (Tables 3, 9 and 10, Figs. 2 and 3). Moreover, by means of further tests, it could be proved that neither cellulose nitrate filters with a pore size of 0,8 micron, which had undergone gamma-radiations, nor filters made of the mixed esters of cellulose, which had been treated with ethylene oxide or autoclaved, differed significantly from the selected type (Tables 5-8). This study therefore clearly demonstrates that - in addition to gelatin filters - a whole range of membrane filters made of cellulose esters yield equally good results and may be used for supervision of the microbial content of the air in closed rooms.

Air Microbiology↗
PubMed1981

[Fluorescence histochemical investigations on the carbohydrate metabolism of the rat brain (author's transl)].

The Regio frontalis posterior of the motor cortex of adult rats was investigated by means of the fluorescence-PAS-reaction. Using various Schiff-type-reagents - substituted with acriflavine, rhodamine B, rhodamine 6G, safranine T - a fluorescent reaction product has been found in different amounts in the pyramidal neurons and in other cellular elements. After application of acriflavine different degrees of PAS-reactivity could be demonstrated in various cortices. Dexamethasone affected an increase of the fluorescent reaction product in individual pyramidal neurons. Ideas on the possible reaction mechanism after application of various Schiff-type-reagents have been proposed.

Acriflavine↗
PubMed1976

Studies on new process procedures in plasma fractionation on an industrial scale. I. Determination of the pH value of ethanol containing protein solutions at low temperatures.

A suitable combined pH electode is evaluated which provides reproducible readings under the extreme conditions of the cold ethanol plasma fractionation procedure. Adequately reproducible correlations are found between the pH measurements in protein solutions with an ethanol content of up to 40% at temperatures as low as -8 degrees C and the determination in diluted samples at room temperature using the standard procedure.

Chemical Fractionation↗