Red blood cell-deformability measurement: review of techniques.

Cell-deformability characterization involves general measurement of highly complex relationships between cell biology and physical forces to which the cell is subjected. The review takes account of the modern technical solutions simulating the action of the force applied to the red blood cell in macro- and microcirculation. Diffraction ektacytometers and rheoscopes measure the mean deformability value for the total red blood cell population investigated and the deformation distribution index of individual cells, respectively. Deformation assays of a whole single cell are possible by means of optical tweezers. The single cell-measuring setups for micropipette aspiration and atomic force microscopy allow conducting a selective investigation of deformation parameters (e.g., cytoplasm viscosity, viscoelastic membrane properties). The distinction between instrument sensitivity to various RBC-rheological features as well as the influence of temperature on measurement are discussed. The reports quoted confront fascinating possibilities of the techniques with their medical applications since the RBC-deformability has the key position in the etiology of a wide range of conditions.

In favour or against euthanasia--dentistry students' opinion.

Euthanasia and a doctor-assisted suicide are not only practiced worldwide, but also legalized in some countries. In Poland they are broadly discussed. The purpose of this paper was to define dentistry students attitude towards human right to ask for death and euthanasia. In the research 148 students of both sexes were questioned. Generally students were against euthanasia in the world as well as in Poland, although men were in majority for euthanasia. Believers were against it due to ethically-religious reasons, while non-believers were for euthanasia motivating it by rational reasons.

Band 3 glycoprotein and glycophorin A from erythrocytes of children with congenital disorder of glycosylation type-Ia are underglycosylated.

Band 3 and PAS-1 (a dimer of glycophorin A) from erythrocyte membranes of three children with congenital disorder of glycosylation, type Ia (CDG-Ia), aged 1 month, 3 years and 10 years respectively, were examined by a new technique that allowed determination of carbohydrate molar composition of glycoproteins separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In CDG children a single N-glycan of band 3 glycoprotein was hypoglycosylated and its mannose content was normal or elevated. Glycophorin A which is the major carrier of erythrocyte sialic acid, was deficient in N-acetylgalactosamine, and sialic acid residues. This finding indicated a partial unglycosylation of O-glycans in glycophorin A. In keeping with the results of PAS-1 analysis, total sialic acid in erythrocyte membranes from CDG children was reduced to 40-56% of normal values. A possible molecular mechanism of hypo- and unglycosylation of band 3 and glycophorin A, respectively, in CDG is discussed.

Neutrophils promote the release of alpha-6-fucosyltransferase from blood platelets through the action of cathepsin G and elastase.

Human blood platelets release alpha-6-fucosyltransferase during coagulation of blood or after stimulation with thrombin or other agonists that cause platelet activation (Antoniewicz et al., FEBS Lett. 244 (1989) 388-390). However, in the absence of neutrophils the thrombin-stimulated platelets release only a small fraction of alpha-6-fucosyltransferase activity (Koscielak et al., Acta Biochim. Polon. 42 (1995) 35-40). We show that the effect of neutrophils is reproduced by cathepsin G or (less efficiently) by elastase, the two enzymes that are released by neutrophils during coagulation of blood. We have also localized alpha-6-fucosyltransferase to membrane and alpha-granule fractions of platelets that had been disrupted by nitrogen cavitation. It is concluded that thrombin-activated neutrophils release cathepsin G and elastase that promote degranulation of platelets and hence the secretion of alpha-6-fucosyltransferase.

[Kazimierz Filip Wize as a physician and a medical ethicist]. / Poglady filozoficzno-etyczne Kazimierza Filipa Wize - psychiatry i filozofa.

Kazimierz Filip Wize (1873-1953) was an interesting and unjustly forgotten, physician-philosopher whose lifetime spanned eight decades over the two past centuries. A disciple of Jan Danysz in Paris, he finally chose to become a psychiatrist. His other fields of interests were philosophy and ethics as well as literature, especially poetry, of which he was an excellent translator from the German. This paper discusses K. F. Wize's life and his philosophical and ethical views, with an emphasis on their specificity, in comparison with the ethical concepts of that time.

Ultrastructural manifestation of pharmacologic inhibition of the activities of lipases and proteases in the cat carotid body.

This study is based on the premise that if a subcellular element of an organ performs an appreciable functional role, then its inhibition could influence the ultrastructural organization of the organ. We addressed this issue in the investigation on the carotid body, a chemosensory organ, by comparing the ultrastructure of its parenchyma in phenylmethylsulfonyl fluoride (PMSF)-injected cat with that of the normal cat. PMSF, an inhibitor of lipases and proteases, induced degenerative changes chiefly in subcellular components other than the neurosecretory and synaptic elements being associated with signal transduction. The study suggests that the inhibited enzymes might also have to do with the carotid body function.