Cation-osmotic Haemolysis in Patients with Retinal Vein Occlusion

The purpose of this work was to use a new technique to assess erythrocyte deformability in patients with retinal vein occlusion. Erythrocyte microrheology changes were measured by cation-osmotic haemolysis (COH) in healthy donors and in patients with both central (n= 6) and branch (n= 16) retinal vein occlusion up to 12 months after the occlusion. The patient group consisted of five patients with ischaemic and 17 with oedematous vein occlusion. The control group consisted of the same number of age-, sex- and risk factor (hypertension)-matched donors. In patients with retinal vein occlusion, COH was significantly decreased compared to the control group. The decrease was most marked at low and high concentrations of incubating media where the differences reached high statistical significance (p<0.01–0.001). In our previous experiments we showed that COH and erythrocyte deformability (ED) are closely related and that COH reflects basic information about erythrocyte deformability. Thus, decreased COH in patients with retinal vein occlusion points to reduced ED in comparison with the control group. We, therefore, assume that impairment in ED together with other microrheological abnormalities contributes to the pathophysiology of changes in patients with retinal vein occlusion.     

Sequence Similarities and Evolutionary Relationships of Influenza Virus A Hemagglutinins

This study brings the analysis of amino acid sequences of hemagglutinin (HA) from the influenza virus A that can infect a wide variety of birds and mammals. 191 sequences belonging to all known 15 HA subtypes were compared. The emphasis was given on functional sites (receptor-binding cavity with its right and left edges) and degree of their conservation in each subtype. Three evolutionary trees of 15 avian HA representatives were constructed: one tree based on the alignment of the entire HA sequences and two trees based on the alignment of HA1 and HA2 chains, respectively. The results have shown that, despite low degree of sequence similarity among the 191 sequences of HA1 subunit, the active site is well conserved, and that there are only marginal differences in the clustering of the individual HA subtypes between the two subunit trees. In this respect, the subtype H9 seems to be the most fluctuating example. The proposals of the probable avian HAs that could be the closest relatives to human (mammalian) HAs were also provided for several HA subtypes.     

The effect of the type of agar on the growth of the fungus Blakeslea trispora]

The relationship between the type of agar used to prepare solid nutrient media and the growth of Bl. trispora strains (+)8A and (-)8A was under study. Bl. trispora culture virtually failed to grow in the media prepared with powder agar, GOST 16280-70: it died after 2-month storage with 2 reinoculations. Bl. trispora grew fairly well in culture media with white frozen lamellar agar (GOST 16280-70) or with white frozen microbiologic agar, GOST 17206-71; the characteristic features of the culture were preserved after 10 monthly reinoculations.