A method of reversed radial immunodiffusion and determination of diphtheria antibodies

Measurements of precipitating antidiphtheria antitoxic and antibacterial antibodies in human blood sera, carried out by this new technique, have demonstrated higher levels of both antibody types in healthy adult vaccinees than in normal subjects who had contacts with diphtheria patients. Convalescents after diphtheria develop elevated levels of antitoxic and antibacterial antibodies, these levels growing to reach the concentrations similar to those in healthy vaccinees.     

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.     

Abnormal sleep pattern and impaired learning capacity in rats with MPTP-induced Parkinsonian syndrome

Rats with the Parkinsonian syndrome induced by systemic injection of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) develop extrapyramidal disorders (oligokinesia, tremor, and rigidity) which depend on the dose and duration of action of MPTP. At 15 and 30 mg/kg MPTP impairs the learning of the conditioned passive avoidance response, shortens both stages of sleep, particularly the paradoxical (REM) stage, and prolongs the period of wakefulness. The mnestic function disturbance is not associated with extrapyramidal disorders, since it develops in their absence. In MPTP-treated rats memory and sleep disorders are interrelated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 288–291, September, 1996     

Peculiar manifestations of familial chlamydiasis of the upper respiratory tract

The aim of the present study was to elucidate the frequency of chlamydial infection in the members of the families having the confirmed disease and concomitant ENT pathologies. Another objective was the comparative analysis of otorhinolaryngological morbidity in the families with and without the carriers of respiratory chlamydiasis. A total of 87 families were involved in the study. Chlamydial infection was diagnosed by a set of laboratory methods including direct immunofluoresent and immunoenzyme analysis as well as polymerase chain reaction (PVR). It was shown that the presence of a patient suffering from respiratory chlamydiasis in the family creates the risk of infection for its remaining members. Moreover the frequency of ENT morbidity increases in the families that serve as a hotbed of chlamydiasis of the upper respiratory tract.     

Characterization of Vibrio cholerae Cef (CHO cell elongating factor): Bioinformatics analysis and experimental data

Bioinformatics analysis of the primary and secondary structure of the Vibrio cholerae Cef (CHO cell elongating factor) protein was carried out. Similarity with triacylglycerol lipases and cytotonic toxins of other bacterial species was observed. Cef was predicted to be a heat-tolerant serine lipase with a Kunitz domain and leucine zipper. These data were confirmed experimentally. The Cefs of the two biotypes of V. cholerae O1, as well as O139 and nonO1, nonO139 serogroups, were purified from the recombinant Escherichia coli strains carrying corresponding cloned genes, and their physicochemical properties and biochemical and biological activities in vitro and in vivo were characterized. Biological activity against the cultured cells was not associated with estherase activity. Evidently, Cef is a bifunctional protein contributing both to the pathogenicity of the cholera agent and to its competitive ability in different ecological niches.