Oxygen consumption as related to the development of the extraembryonic membranes and cardiovascular system in the European pond turtle (Emys orbicularis) embryogenesis

The rate of oxygen consumption (V(O2)), embryo mass, distribution and mass of the chorioallantoic membrane (CAM), heart rate (HR), heart mass, and amnion rhythmic contractions (ARC) were studied in eggs of the European pond turtle (Emys orbicularis) incubated at 28 degrees C for 62.5+/-0.3 days. The V(O2) rapidly increased beginning from incubation day 19 (D19) to a maximum on D50 and then decreased until pipping. The rapid V(O2) rise was correlated with an increase in the CAM surface and mass, heart mass, and ARC amplitude, whereas the functional parameters such as HR and ARC frequency remained unchanged. The drop in V(O2) before pipping was accompanied by a decrease in HR, while the heart and CAM masses were almost constant. In the cases of short-term temperature deviations of +/-3 degrees C from 28 degrees C, changes in (O2) were significant until D50 and nonsignificant after that, the changes in ARC frequency and HR being significant at all stages studied. Thus, the developmental V(O2) changes were contributed mainly by the slow morphogenetic processes during D19-D50, whereas changes in functional parameters began to play a role at later stages. The response to temperature fluctuations was mediated by a rapid change in functional parameters at all these stages.     

The motor activity of the chick embryo amnion in the late stages of development. The role of serotonin and noradrenaline]

Experiments with 13- to 19-day-old chicken embryos maintained at 37 degrees C were conducted using direct registration of embryonic movements and amnion pulsation. It is shown that in the non-innervated and lacking blood vessels non-striated-muscled amnion, motoric activity could be observed nearly up to the end of the embryonic development, not only during 5 to 14 days old interval as it was supposed earlier. In accordance with our previous results indicating important role of biogenic amines (serotonin and noradrenaline) in the regulation of motoric activity of the chicken embryo amnion at earlier and middle ages, this study provides some evidences of the humoral regulatory mechanism even at later embryonic stages. After being injected into amniotic fluid of older embryos, the serotonin stimulates and noradrenaline inhibits amnion motoric activity (the both are taken at final concentration of 10(-7) to 10(-6) M). Serotonin's receptors blocator, the cyprogeptadin, suppress while beta-adrenoreceptors' blocator, the propranolol, activates intact amnion motorics ( both are taken at final concentration of 10(-7) to 10(-5) M).     

Changes in the etiologic structure of Sonne shigellosis in its multiyear dynamics

The dynamics of Sonne dysentery morbidity in connection with changes in the structure of S. sonnei circulating among the population of Leningrad for the period of 1959-1984 was studied. Considering such sign as the leading fermentovar, three smaller periods were established in this stretch of time. Changes in the structure of circulating shigellae were accompanied by changes in the intensity and direction of tendencies or decrease in the manifest and asymptomatic forms of infection, as well as in annual morbidity levels and seasonal rises. A slow decrease in morbidity, which started in 1974, occurs in the presence of the predominant circulation of S. sonnei, fermentovar II, among the population; this fermentovar showed greater virulence and immunogenicity than other biovars. One of the decisive moments characterizing the dynamics of the epidemic process of Sonne dysentery is the intensity of the circulation of shigellae in the S-form, and the intensity of the population immunity of the host, linked with this fact, is subject to phasic fluctuations during each annual epidemic cycle.     

Utilization of serological methods in the retrospective diagnosis of cholera and in detecting vibrion carriers]

Sensitivity and specificity of the three serological methods were studied comparatively: the vibriocidal test, the reaction of bacterial agglutination and of indirect hemagglutination, with the use of erythrocytes sensitized with the vibrio lyzate, cholera species O-antigen and cholerogen. Investigations were conducted with the blood sera of cholera patients, vibrio carriers and contacts. Vibriocidal test proved to be the most sensitive; its data correlated with the results of bacterial agglutination and indirect hemagglutination with erythrocytes, sensitized with the lysate of the vibrios and the cholera O-antigen. None of the used serological methods provided a 100% coincidence with the results of bacteriological analysis. The frequency of detection of anticholera antibodies decreased in the following order: cholera patients, vibrio carriers, contacts.     

Transposition and inheritance of Bordetella Tn-element in Escherichia coli K12

B. pertussis genetically mobile element TnBp3 integrates the plasmid in E. coli chromosome. During culturing under nonselective conditions the majority of cells of some E. coli strains lose the kanamycin resistance marker, which indicates the instability of TnBp3 inheriting. The stability of inheriting the integrated structure is higher in E. coli cells with recB-21 recC-12 sbcB-2 mutations. The role of RecBC recombination system in extrusion of TnBp3 is discussed.     

Intensity of the production of rheumatoid factor in patients with different degree of sensitization to Borrelia garinii antigens

The content of rheumatoid factor and serum IgA, IgM and IgG in patients with different degree of sensitization to B. garinii antigens is evaluated. An increase in the titer of rheumatoid factor in patients with a high content of antibodies to Borrelia was established. In addition, an increased concentration of serum immunoglobulins in the presence of Borrelia infection was registered. The mechanisms of autoimmune reactions are discussed, proceeding from the biological properties of the causative agent of Lyme disease.     

Intensity of the production of rheumatoid factor in patients with different degrees of sensitization to Borrelia garinii antigens

The content of rheumatoid factor and the levels of IgA, IgM, IgG in patients with different degrees of sensitization to Borrelia garinii antigens were studied. The titer of rheumatoid factor was found to increase in accordance with the growth of the levels of anti-Borrelia antibodies. A rise in the concentration of serum immunoglobulins simultaneously with the development of Borrelia infection was registered. The mechanisms of autoimmunization are discussed, taking into account the known biological properties of the causative agent of Lyme disease.