Role of B-lymphocytes in inactivating allogenic stem cells]

Antisera to membrane antigens of B lumphocytes eliminated the capacity of lymphocytes to inactivate allogenous stem cells by 60%; however, lymphocytes from the lymph nodes of B mice possessed no inactivating capacity. T-lymphocytes were the main criteria inactivating allogenous stem cells. Cooperating with T-lymphocytes, B-lymphocytes probably contributed to inactivation of precursor cells realized by T-lymphocytes. However, the presence of B-lymphocytes in the killer cells population was not a determinant, since T-lymphocytes were capable of inactivating allogenous stem cells without any participation of B-lymphocytes.     

Genetic basis of influenza virus virulence: gene composition and virulence of reassortants between mouse-adapted and nonadapted strains from different subtypes

Reassortment analysis of the pneumovirulence for mice marker of influenza virus has been performed. The original A/USSR/90/77 (H1H1) influenza virus strain or its mouse-adapted variant were crossed with a variant of A/Aichi/2/68 (H3N2) influenza virus highly virulent for mice. The reassortant having HA gene of the original A/USSR/90/77 virus and the other genes of the highly virulent A/Aichi/2/68 strain was avirulent for mice, whereas a similar reassortant possessing HA gene of the mouse-adapted A/USSR/90/77 strain was as virulent as A/Aichi/2/68 parent virus. The reasortant having HA and M genes of A/Aichi/2/68 and other genes of the mouse-adapted A/USSR/90/77 was moderately virulent, resembling in this respect the latter parent. The data indicates that changes in the different genes in course of viral adaptation to mice result in a differential acquisition of virulence for mice.     

Effect of radiation on cell interactions in the phenomenon of non-syngeneic stem cell inactivation. Changes in B-lymphocyte function after irradiation

A study was made of the changes in the mode of interaction between T- and B-lymphocytes of mouse lymph nodes with respect to the phenomenon of inactivation of non-syngeneic haemopoietic stem cells. It was shown that irradiation of B-lymphocytes with doses of 77.4--232.2 mC/kg changes their helper activity into a suppressor activity with regard to T-cell-killers having a low electrophoretic mobility.     

Antibiotic sensitivity and the characteristics of transmissive R plasmids in Shigella belonging to various species]

Sensitivity of 241 Shigella strains isolated from patients at various regions of the USSR in 1975--1978 was tested with respect to 14 antibiotics by the method of serial dilutions. 90.5 per cent of the isolates proved to be resistant to the antibacterial drugs and the greater part of 75.9 per cent of them had multiple resistance. The resistance of the Shigella was most pronounced and frequent with respect to tetracycline, streptomycin, levomycetin, as well as ampicillin and carbenicillin. Gentamicin, cephaloridin, polymyxin M, kanamycin, monomycin, neomycin and rifampicin were highly active against the Shigella. More than 50 per cent of the isolates were sensitive to levomycetin, ampicillin and carbenicillin. Differences in the frequency of the resistant strains and the spectrum of the antibiotic resistance of different Shigella subgroups (species) were observed. The study of 173 multiple resistant Shigella strains showed that about 67 per cent of the strains had a capacity for transduction of the resistance markers into the recipient cells of E. coli. The conjugative R-plasmids were most frequent in Sh. boydii and Sh. sonnei (95 and 95 per cent respectively), less frequent in Sh. flexneri and Sh. newcastle (68 and 53 per cent respectively) and least frequent in the mannitol negative Shigella (25 per cent). The capacity for transduction of R-plasmids in the strains carrying the determinants of resistance to 2 or 3 antibiotics was higher than in the strains carrying the determinant of resistance to one antibiotic. The clinical Shigella strains tested mainly had transmissive R-plasmids of fi--character (79 per cent).     

Incomplete influenza virus: partial functional complementation as revealed by hemadsorbing cell count test.

In MDCK cells inoculated with an appropriate dilution of influenza virus, single hemadsorbing cells could be counted 8 h postinfection against a background of nonadsorbing cells. Standard virus preparation exhibited a linear relationship between the virus dilution and the number of hemadsorbing cells. With incomplete virus preparations obtained by passages of undiluted virus in chicken embryo, the dependence was nonlinear. A ts mutant (ts-29) of A/FPV/Weybridge (Hav1 Neq1) failed to convert MDCK cells into a hemadsorbing state at 42 degrees C. The ability of ts-29 to produce hemadsorbing cells could be rescued by incomplete wild-type virus. The capacity of incomplete virus for this partial functional complementation was inactivated by UV irradiation with one-hit kinetics. The size of the target was estimated to be 5.5 times smaller than that of the virus genome. The results suggest that at least some of the influenza virus genes in defective interfering particles are functional.     

Factors that control the differentiation of stem cells. I. The change in direction of hematopoietic stem cell differentiation under the effect of differentiating T-lymphocytes]

A mixed transplantation of bone marrow cells, and lymph nodes or thymic cells of mice CBA strain into lethally irradiated hybrid recipients (CBAXC57B1)F1 is accompanied with changes in the differentiation pattern from a mainly erythroid to a mainly granuloid way. Thymectomy of either donor of bone marrow cells or recipients, or both, destroys the stem cell differentiation in the direction of granulopoieseis. Intact syngeneic lymphocytes normalize differentiation of the stem cells, but in the presence of tissue antigens these provide for the stem cell differentiation mainly in the direction of granulopoiesis. The differentiation of stem haemopoietic cells is accomplished under the thymic and lymphocyte control. T-differentiating lymphocytes (Td) are the lymphocytes controlling the stem cell differentiation.     

Revision of the taxonomic position of the Olkhon mountain vole (Rodentia,Cricetidae)

The phylogenetic position of the Olkhon mountain vole (Alticola olchonensis Litvinov, 1960) was studied using the sequences of four nuclear (BRCA, GHR, LCAT, and IRBP) and one mitochondrial (cyt. b) gene. Until now multiple studies of the systematic position of this vole had been based exclusively on morphological data, while the major taxonomic references contain contradictory information regarding both the subgeneric and species status of this animal. It was established that the molecular data and morphology data allow us to concern the Lake Baikal vole unambiguously as a part of the nominative subgenus Alticola instead of Aschizomys.     

The effects of coastal water pollution of the Black Sea on the blood biomarkers of the round goby <Emphasis Type="Italic">Neogobius melanostomus</Emphasis> Pallas, 1811 (Perciformes: Gobiidae)

The activities of antioxidant enzymes and the contents of the oxidized forms of the proteins in the blood of the Black Sea round goby Neogobius melanostomus, which were sampled in the waters of Sevastopol in 2003 and 2012, were studied. An increase in the values of the tested biomarkers in fish catches of 2012 compared to those of 2003 was recorded. The causes for the observed changes are discussed.