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Biomedical subjects

O Behnke

Publications and source records attributed to O Behnke.

7 recordsLinked to original sources
PubMed1992

Degrading and non-degrading pathways in fluid-phase (non-adsorptive) endocytosis in human blood platelets.

A morphological study of the endocytic pathways in non-activated human blood platelets has been made using fibrinogen-stabilized colloidal gold as a fluid-phase marker, and acid phosphatase as a marker for lysosomes. Two pathways of constitutive endocytosis were demonstrated: one pathway was mediated by clathrin coated vesicles which formed at the platelet surface and the surface-connected, canalicular membrane system and which fuse with and deliver their contents to the platelets' secretory alpha-granules. The other pathway follows a degrading, endosomal-lysosomal route and appears to be clathrin independent. Endosomes containing marker particles originate from the surface-connected canalicular system, through which ambient fluid percolates. An account is given of the pleomorphism of platelet lysosomes, and evidence is presented for a lysosomal, focal autophagia in platelets which may be linked to platelet senescence. Lysosomes in non-activated platelets are thus involved in the same processes as lysosomes in other cells.

Alkaline Phosphatase↗
PubMed1978

Megathrombocytopenia associated with glomerulonephritis, deafness and aortic cystic medianecrosis.

Macrothrombocytopenia associated with glomerulonephritis and deafness has only been reported in a few patients since it was first described in 1972. We present a patient with macrothrombocytopenia, glomerulonephritis, progressive uraemia and progressive sensorineural deafness associated with cystic medianecrosis of the ascending aorta and malformation of the aortic valves. The patient had consistently low platelet counts but no clinical signs of a defect haemostasis. The giant platelets were characterized by their size, averaging 11 micron in diameter, elaborate maze-like membrane formations, abundance of microtubules, and the total absence of very dense granules.

Adolescent↗
PubMed1978

Harvesting of granulocytes for transfusion therapy by haemonetics 30. Yield, morphology and in vitro functions of collected granulocytes.

By means of a Haemonetics 30 blood cell separator white blood cells (WBC) were collected for transfusion purposes from 21 normal unstimulated donors. Citrated Hydroxyethyl Starch (HES) was used as anticoagulant. A mean yield of 1.13 x 10(10) WBC was obtained in 2 1/2-3 h. Half of the collected WBC were PMN cells containing a few per cent band forms, the other half lymphocytes and monocytes (12%). No shift in the distribution of WBC was found during the leucapheresis. Light and electron microscopy did not reveal any damage or changes in the structure of the processed granulocytes. The Trypan blue exclusion test showed 99% vital cells. In vitro assessment of the chemotactic and bactericidal activity of the collected granulocytes showed normal function. Also the content of myeloperoxidase was within normal range.

Blood Cell Count↗
PubMed1977

Electron microscopical identification of the committed precursor cell of the megakaryocyte compartment of rat bone marrow.

In the rat bone marrow, cells of the megakaryocyte line of differentiation are the only hemopoietic cells which show cytochemically demonstrable Acetylcholineesterase activity (AchE; EC 3.1.1.7). A small number of morphologically unrecognizable cells exhibit AchE activity in their Golgi complexes. These cells are identified as committed precursor cells of the MK compartment.

Acetylcholinesterase↗