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Biomedical subjects

E Meier

Publications and source records attributed to E Meier.

At least 109 records · Page 6Linked to original sources
PubMed1982

Specific recognition of the neuronal cell surface by an antiserum raised plasma membrane preparations of immature rat cerebellum.

A brain specific antiserum was prepared by immunizing rabbits with a crude membrane fraction from 8-day old rat cerebella. In immunofluorescence studies the antiserum labeled the perikarya and processes of cultured cerebellar neurones. In contrast, other cell types, encountered in cerebellar cultures including astrocytes, endothelial cells and fibroblasts, were consistently unstained. The antiserum when used in crossed immunoelectrophoresis with Triton X-100 solubilized brain extracts reacted predominantly with one antigen that could be identified as the D2 protein.

Animals↗
PubMed1982

Cognitive impairments of aphasics in picture sorting and matching tasks.

On the basis of earlier experiments showing a differential deficit of aphasics in picture sorting and matching tasks, two experiments were conducted to test the conjecture of a specific deficit of aphasics in the analytical appraisal of individual features. Broca's and Wernicke's aphasics--according to clinical diagnoses and the Aachener Aphasie Test--were compared with patients having right-hemisphere lesions or left-hemisphere lesions without aphasia. Both groups of aphasics differed from the control groups in the sorting task, irrespective of the sorting criterion, but the differences were small. The picture matching task did not discriminate between groups. Obviously, the basic assumption has to be modified with respect to specific conditions of task requirements. The experimental literature is reviewed.

Aphasia↗
PubMed1982

Differences between GABA receptor binding to membranes from cerebellum during postnatal development and from cultured cerebellar granule cells.

GABA receptor binding sites were determined in membranes from cerebella of 7-, 15- and 60-day-old rats and cerebellar granule cells derived from 7-day-old rats and cultured for 8 days using [3H]GABA as the ligand and nonradioactive GABA to measure nonspecific binding. Membranes from cerebellum at all postnatal stages exhibited at least two binding sites for GABA with binding constants around 7-9 and 150-750 nM, respectively. The total number of binding sites expressed on the basis of total protein increased 10 times between 7 and 60 days of age and 2 times between 15 and 60 days. The latter increase could be quantitatively accounted for by an increase in the number of low affinity sites. In contrast to this, membranes from cultured granule cells only exhibited the high affinity binding site (KD 7.1 +/- 0.5 nM) and the number of binding sites was comparable to that of cerebellar membranes from rats of the corresponding age (15 days old). GABA analogues such as muscimol, piperidine-4-sulphonic acid, homo-beta-proline, THIP, and isoguvacine were potent displacers of GABA binding to cultured granule cells, whereas nipecotic acid and guvacine had no effect.

Age Factors↗
PubMed1981

Influence of dietary histidine on tissue histamine concentration, histidine decarboxylase and histamine methyltransferase activity in the rat.

Three-week-old male rats were fed for two weeks diets supplying inadequate, adequate, or excess amounts of histidine. After the 2-week feeding of the experimental diets, the rats were killed. Brain, gastrocnemius muscle, kidney and stomach were removed and analyzed for histamine and free-histidine as well as for the degradative enzyme, HMT, and the histamine-synthesizing enzyme HDC. The following results were obtained: As the levels of dietary histidine increased, (1) tissue concentrations of free-histidine and of histamine increased in all the tissues analyzed. (2) The increase of histamine was greatest in brain and stomach (5- and 4-fold, respectively), but less in kidney and muscle (2-fold). (3) HDC activity was not detected in muscle, but doubled from the lowest to the highest histidine intake in brain and increased almost 6-fold between the lowest and the highest histidine levels in stomach. (4) Kidney HDC decreased from the lowest to the two higher levels of dietary histidine. (5) HMT activity increased nominally in brain and not significantly in kidney; none was detected in either muscle or stomach. (6) Brain and kidney, tissues with considerable HMT activity, had almost no histamine. The increases in tissue histamine concentrations observed in the tissues analyzed generally reflected the changes and magnitudes of enzyme activities for HMT and HDC. The results in the rat differ in important ways from those previously observed in chickens as follows: (1) Histamine concentrations as a function in dietary histidine decreased in the chick. (2) Both HDC and HMT activities were present in chick muscle tissue. (3) HDC activity in chick stomach decreased sharply as a function of dietary histidine.

Animals↗
PubMed1978

A differential stain for neuronal nucleoli in unfixed cryostat sections.

The Klüver-Barrera procedure, using luxol fast blue and cresyl violet for a combined nissl and myelin stain, was adapted to unfixed cryostat sections. Neuronal nucleoli appeared as distinct dark blue structures. The color contrast between violet Nissl substance and the nucleoli facilitated their recognition in human and in rat central nervous systems. This modified staining procedure enabled us to combine a counting of nerve cells with a histochemical investigation by applying each technique to a different set of sections cut from the same block of unfixed, frozen brain tissue.

Animals↗
PubMed1977

Proteins from disassembled microtubules characterized by oligospecific antisera.

The immunochemical properties of in vitro reassembled microtubules were investigated by immunoelectrophoretic techniques. The tubulin dimer gave no measurable immunochemical response, but the tubulin oligomer, the tau-factor and an antigen of about 135 000 daltons all gave precipitating antibodies. Those four proteins were investigated in reassembled microtubules, in DEAE-cellulose purified tubulin, and after molecular sieve chromatography of disassembled and NaCl-dissociated microtubules. Reconstitution of tubulin oligomer from tubulin dimer and tau-factor was also performed. The presence of a unique antigenic structure on tubulin oligomer which was not found in the dissociated components and the role of this aggregate as a nucleation center or intermediate in the assembly of microtubules is discussed.

Animals↗