Possibility of the intrauterine sensitization to benzylpenicillin and ampicillin in Syrian hamsters]

Immunization of Syrian female hamsters with benzylpenicillin and ampicillin resulted in positive skin reactions of the retarded type and decreased titers of the blood antihistamine factor (AHF) in a part of the posterity. Penicillin allergy was in particular observed in the posterity of the female hamsters immunited before the pregnancy. The state of allergy to penicillins was found in the posterity of the female hamsters with both the positive and negative skin reactions on immunization during the 2nd half of the pregnancy.     

Experimental study of the organotropic side-effect properties of polymyxin B]

Toxicity of Soviet polymyxin B and its effect on the central peripheral nervous system, blood circulation, respiration, smooth muscles, functional liver and kidney state, growth and development of young animals, the picture of the peripheral blood were studied in acute and chronic experiments on various species of animals. It was found that polymyxin B had a suppressing effect on the peripheral n-cholinoreactive systems of the neuromuscle synapses of the skeletal muscles and ganglia of the sympathic and parasympathic innervation and deprimizing effect on the central nervous system. Caffeine, adrenaline and calcium chloride proved to be the antagonists of the neurotoxic effects of polymyxin B. The chronic experiments revealed that polymyxin B induced disorders in the kidney function and morphological changes in the glomeruli after its repeated administration. No significant effect of polymyxin B on the growth and development of the young animals, the functional state of the liver and the picture of the peripheral blood was observed when the drug was used in doses corresponding to the therapeutic ones in clinics.     

Frequency, dynamics, and structure of congenital malformations in populations under long-term exposure to ionizing radiation]

Information on the dynamics, frequency, and structure of congenital malformations (CMs) and chromosomal diseases in two generations of rural populations from the Semipalatinsk region was obtained for the first time. The tests performed in the Semipalatinsk nuclear test site (STS) for many years were demonstrated to deteriorate the genetic health of the populations of the zones of extreme and maximum radiation risks. Mutagenic and teratogenic effects of long-term ionizing irradiation were detected. These were mainly expressed as an increase in the frequencies of strictly registered CMs (SR CMs), including the Down syndrome, multiple malformations (MMs) and microcephaly (1.45 +/- 0.11, 1.39 +/- 0.01, and 0.77 +/- 0.05 per 1000 births, respectively). SR CMs exhibited linear trends toward higher frequencies in two generations of exposed persons after surface nuclear tests in 1949-1963. Their frequency was strongly correlated with the effective population dose of radiation; the main population genetic parameters (inbreeding coefficient, endogamy index, etc.) had less pronounced effects on Cms.     

Distribution,population structure and salinity tolerance of the invasive amphipod Gmelinoides fasciatus (Stebbing) in the Neva Estuary (Gulf of Finland,Baltic Sea)

In the early 1970s, the Baikalian amphipod Gmelinoides fasciatus (Stebbing) was intentionally introduced into several lakes in the Gulf of Finland basin in order to enhance fish production. By 1996, G. fasciatus successfully colonized the littoral zone of Lake Ladoga and, via the Neva River, invaded the Neva Bay, the freshwater part of the Neva Estuary. In 1999, G. fasciatus was first registered in the inner Neva Estuary, the very first record of the Baikalian amphipod in brackish waters of the Baltic Sea. Distribution, abundance, reproduction and population structure of G. fasciatus in the Neva Estuary were studied during 1998–2000. In some locations of the Neva Estuary, maximum densities of G. fasciatus reached 3500 ind. m⁻². In general, density and biomass of G. fasciatus in the freshwater part of the Neva Estuary were higher (around 1.5 fold) than in the brackish-water part. Fecundity of this amphipod averaged 10–20 eggs per female, depending on body size of females and season. In order to assess the possibility of further spread of G. fasciatus in the Baltic Sea, the salinity tolerance of this species was determined in a series of laboratory experiments. Our results showed that the invasive amphipod G. fasciatus is potentially able to colonize shallow coastal habitats of, for example, the Gulf of Bothnia, Gulf of Riga and other parts of the Baltic Sea with water salinities ranging from 1 to 5 psu.