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B Rapp

Publications and source records attributed to B Rapp.

26 records · Page 2Linked to original sources
PubMed1988

Galvanotaxis of human granulocytes. Dose-response curve.

The galvanotactic response of human granulocytes was investigated theoretically and experimentally. The basic results are: (i) The granulocytes move towards the anode. (ii) The directed movement has been quantified by two different polar order parameters--the McCutcheon index and the average of cos phi. (iii) The polar order parameters are a function of the applied electric field (= dose-response curve). (iv) The inverse of the galvanotactic constant of migrating cells (analogous to the Michaelis-Menten constant) has a value of -0.2 +/- 0.03 V/mm. (v) The galvanotactic response of granulocytes is a non-cooperative process with a cooperativity coefficient of 1 +/- 0.2. (vi) The galvanotactic constant is a function of pH. (vii) The protein essential for the galvanotactic response is very likely a G-protein.

Cell Movement↗
PubMed1979

Photosynthetic carbon reduction pathway is absent in chloroplasts of Vicia faba guard cells.

Four cell types from Vicia faba Linnaeus "Long Pod" leaflets were assayed for three enzymes unique to the photosynthetic carbon reduction pathway. The enzymes were ribulosebisphosphate carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39], phosphoribulokinase (ATP:D-ribulose-5-phosphate 1-phosphotransferase, EC 2.7.1.19), and glyceraldehyde-phosphate dehydrogenase (NADP(+)) (phosphorylating) [D-glyceraldehyde-3-phosphate:NADP(+) oxidoreductase (phosphorylating), EC 1.2.1.13]. On a dry weight basis, these enzyme activities were about twice as high in palisade as in spongy parenchyma. Two of the enzymes were not detected in epidermal cells and the other was present in only a trace amount. In guard cells, these enzyme activities were absent or present at les than 1% of the amount in palisade cells. Immunoelectrophoresis showed that ribulosebisphosphate carboxylase was absent in extracts of guard cell protoplasts. Microscopy confirmed the abundance of typical guard cell chloroplasts. These results demonstrate the absence of the photosynthetic carbon reduction pathway in guard cell chloroplasts. This is the only chloroplast type known to be deficient in this pathway in plants whose primary CO(2) acceptor is ribulose bisphosphate. Possible reasons for the absence of this pathway in guard cells are discussed.

Journal Article↗
PubMed1973

Comparative study by the frequencies of the rotatory and sinusoidal stimulation with a stereotaxic experimental method.

The analysis of the records, obtained with six rabbits which were submitted to the combined antagonistic stimulations, peripheric rotatory and central stereotaxic, has not allowed to find a systematic relationship between the two rotatory tests. If the physical equivalence seems to be real where one takes the RMS value of the sinusoidal accelerations (and not the maximum acceleration for a half-period) the physiological equivalence however has still to be sought after.

Animals↗