Genetic and cytogenetic marking of the neurological quaking mutation (qk) in laboratory mice

A new genetically balanced breeding system with a low recombination rate is offered for purposes of maintenance and early identification of mice with the recessive autosomal qk mutation. Dominant T mutation (Brachyury) and recessive t12 mutation of T locus were chosen as genetical markers and Robertsonian translocation Rb (8.17) 1 Iem served as a cytogenetical marker of the qk mutation. As shown by the results, none of genetical mutations studied (qk, T or t12) can be distinguished on differentially stained chromosomal preparations. Hybrid mice of the +T/qk+ genetic compound have a high rate (44%) of homozygous qk/qk offspring. The latter can be identified with the high probability (96%) in foetuses and newborns, according to their tail length, well before the typical neurological symptoms are evident. In the offspring of the F1 hybrids+Rb 1 Iem/qk+ the frequency of qk/qk mice is near 20% and they can be identified with the probability 95% at any stage of the development by means of chromosomal analysis. Hybrids of the +t12/qk genotype are very convenient for prolonged maintenance of the qk gene in a balanced heterozygous condition. Some features of functional similarities between the qk gene and recessive mutations of T locus are discussed. Genetical and cytogenetical markers used in this work provide some novel approaches for experimental analysis of the qk gene expression at early stages of the development.     

Space flight effects on skeletal bones of rats (light and electron microscopic examination)

In the light and electron microscopes, long tubular bones of Wistar rats that were flown for 22 d onboard the Cosmos-605 biosatellite and were exposed to a ground-based simulation experiment were examined. About half of the flight rats showed osteoporosis of metaphyses which was usually combined with a decrease of the mass of the primary spongiosa in the vicinity of the epiphyseal cartilaginous plate. This gives evidence that the growth of the bones could have been inhibited in flight. The light and electron microscopy of bones of flight rats revealed wide osteocyte lacunae which could have been produced by perilacunar osteolysis. In the simulation experiment, reduction in the metaphyseal spongiosa occurred only in one-third of the rats and was less pronounced than in flight rats; no decrease of the mass of the primary spongiosa near the cartilaginous plate was noted. Histological investigation of bones 27 d postflight demonstrated that that time period was not enough to eliminate all the changes in the bones tested.     

Immunological properties of human decidual macrophages--a possible role in intrauterine immunity

Our aim was to investigate the contribution of decidual macrophages, which constitute an important immune component of the decidua in late gestation, to intrauterine defence mechanisms. Using flow cytometry we examined the ability of decidual macrophages, isolated from term decidua, to bind and phagocytose fluorescence-labelled bacterial and yeast bioparticles. We also assessed their ability to generate superoxide radicals and tumour necrosis factor-alpha following lipopolysaccharide challenge. Decidual macrophages bound bacterial and yeast particles in a dose-dependent manner, which subsequently led to phagocytosis. These macrophages also produced superoxide radicals and the pro-inflammatory cytokine TNF-alpha when challenged with bacterial lipopolysaccharides. These results suggest a role for decidual macrophages in pathogen recognition and clearance during pregnancy, and, therefore, they are likely to protect the fetus against intrauterine infections which might otherwise lead to preterm labour.     

Differential diagnosis of allergic diseases of the upper respiratory tract

The author studied various manifestations of the most widely spread clinical forms of allergic diseases of the upper respiratory tract, namely, the bacterial, atopic and combined ones. In addition to clinical investigations laborotory, immunologic and functional tests were conducted. The difference in pathogenesis affected the clinical course of the disease. Some symptoms depended on the kind of sensibilization, others on how strongly pronounced the pathologic process was.