The increase in aneuploidy of embryos Is associated with pathological morphology of the sperm

Chromosomes of embryos of couples with reduced number of morphologically normal sperm cells (less than 4%) and couples with a normal level of morphologically normal sperm cells (over 4%) has revealed significant differences. In the group with a low level of normal spermatozoa, the frequency of embryos with normal chromosomes is significantly reduced and incidence of sex chromosome trisomies and autosomal monosomies and trisomies is increased; a tendency to decrease has been found for the frequency of male embryos. The obtained data may be useful to establish additional criteria for preimplantation genetic screening in the case of male infertility.     

Patterns of Downstream Migration of Pink Salmon Oncorhynchus gorbuscha in the Malaya Khusi River (Sakhalin Oblast)

Journal of Ichthyology - Patterns of downstream migration of juvenile pink salmon Oncorhynchus gorbuscha in the Malaya Khusi River (northeast of Sakhalin island) are revealed as a result of...     

Exogenous compounds in studying the mechanism of electron-excited state formation in bioluminescence

Using a series of exogenous fluorescent molecules as potential energy acceptors, the hypothesis on the activity of the upper electron-excited states in bioluminescence was tested. The results in bacterial and firefly bioluminescent enzyme systems were compared. Similar activity to the energetic precursor in bacterial bioluminescence was not proven in the case of the firefly system, the result of a very efficient intramolecular energy transfer in the emitter of the firefly bioluminescence. The influence of a number of metallic salts on a bacterial bioluminescent enzyme system was studied. Bioluminescence inhibition coefficients were compared to the free energies of electron withdrawing of cations. The correlation shows that inhibition and activation of luminescence intensity result from the effects of cations on electron transfer in the bioluminescent system.     

Functional Gene Hybridization Patterns of Terrestrial Ammonia-Oxidizing Bacteria

Abstract The biochemical pathway and genetics of autotrophic ammonia oxidation have been studied almost exclusively in Nitrosomonas europaea. Terrestrial autotrophic ammonia-oxidizing bacteria (AAOs), however, comprise two distinct phylogenetic groups in the beta-Proteobacteria, the Nitrosomonas and Nitrosospira groups. Hybridization patterns were used to assess the potential of functional probes in non-PCR-based molecular analysis of natural AAO populations and their activity. The objective of this study was to obtain an overview of functional gene homologies by hybridizing probes derived from N. europaea gene sequences ranging in size from 0.45 to 4.5 kb, and labeled with 32P to Southern blots containing genomic DNA from four Nitrosospira representatives. Probes were specific for genes encoding ammonia monooxygenase (amoA and amoB), hydroxylamine oxidoreductase (hao), and cytochrome c-554 (hcy). These probes produced hybridization signals, at low stringency (30 degreesC), with DNA from each of the four representatives; signals at higher stringency (42 degreesC) were greatly reduced or absent. The hybridization signals at low stringency ranged from 20 to 76% of the total signal obtained with N. europaea DNA. These results indicate that all four functional genes in the ammonia oxidation pathway have diverged between the Nitrosomonas and Nitrosospira groups. The hao probe produced the most consistent hybridization intensities among the Nitrosospira representatives, suggesting that hao sequences would provide the best probes for non-PCR-based molecular analysis of terrestrial AAOs. Since N. europaea can also denitrify, an additional objective was to hybridize genomic DNA from AAOs with probes for Pseudomonas genes involved in denitrification. These probes were specific for genes encoding heme-type dissimilatory nitrite reductase (dNir), Cu-type dNir, and nitrous oxide reductase (nosz). No hybridization signals were observed from probes for the heme-type dNir or nosz, but Nitrosospira sp. NpAV and Nitrosolobus sp. 24-C hybridized, under low-stringency conditions, with the Cu-type dNir probe. These results indicate that AAOs may also differ in their mechanisms and capacities for denitrification.     

Detection of a perforin-like protein from the soluble cytotoxic factor of natural killer cells

The protein composition of the cytolytic factor (NKCF) secreted by natural killer cells was analyzed. Natural killer cells were isolated from spleens of nude rats and purified in the Percole gradient. SDS-PAAG analysis of NKCF revealed the presence of major proteins with an approximate molecular weight of 62-67 kDa. Biochemical properties of these proteins such as fractionation on a TSK-3000 SW gel filtration column, electrophoretical mobility in reduced conditions, enhanced cytolytical activity in the presence of Ca2+ demonstrate the similarity with the pore-forming protein--perforin. Apart from the major component, proteins with m. w. 42 kDa, 31-28 kDa, 17 kDa and 12-14 kDa were also found. It is possible that the Ca2+-independent cytolytical activity is bound to one of these minor protein components of NKCF.     

Pancreas annulare in human embryos

2 cases of pancreas annulare with duodenal stenosis were found among 3,307 induced abortuses of 5-12 weeks where the pancreatoduodenal area was available for examination. This corresponds to a 0.06% incidence, greatly exceeds the occurrence of the anomaly in neonates and suggests partial prenatal elimination of embryos with pancreas annulare and duodenal stenosis. Microscopic examination of serialed embryonic sections gives evidence of (1) the origin of the ring from the ventral anlage; (2) the underdevelopment of the ring material, which later may cause fibrosis of the annulus, usually observed in neonates; (3) the origin of duodenal stenosis in case of pancreas annulare till 8 weeks of fetal life; (4) the development of such stenosis not only due to atrophy of duodenal segment, resulted from compression by the pancreatic ring, but also due to anomalous differentiation of intestinal segment, the cause of which may be the disturbance of morphogenetic correlations.     

Abnormal Condensation of Meiotic Chromosomes Caused by the mei8 Mutation in Rye Secale cereale L.

Inheritance of two spontaneous meiosis-specific mutations with similar cytologic phenotype was studied. Both mutations were independently obtained from two rye populations (Vyatka variety and weedy rye). Both mutations are recessive, allelic, and monogenically inherited; the corresponding gene is designated mei8. The mutant alleles of the gene cause abnormal meiotic chromosome structure expressed as irregular compaction along the chromosome length, chromatin stickiness at all stages of meiosis, and chromosome fragmentation in anaphase I.     

The role of ACTH(5-8) and beta-MSH(5-8) fragments in the organization of the self-stimulation reaction

The experiments on rats have shown that intraperitoneal administration of ACTH5-8 fragments in a dose of 40 ng per kg altered considerably the character of self-stimulation reaction and the behaviour of rats. Searching activity and self-stimulation reaction were intensified, with the latter characterized by the onset of aversive components, that disappeared 24 hours later. Activation depended on the site of stimulation. Two phases of activity were noted (the first 0.5-1 h and the second 4.5-6 h after ACTH5-8 injection). beta-MSH5-8 fragment, when injected intraperitoneally in a dose of 20 ng per kg, had no effect on self-stimulation reaction and the behaviour of animals.