The anti-arrhythmia properties of bonnecor metabolites

The experiments on the model of aconitine-induced arrhythmia in anesthetized rats and awake dogs with cardiac rhythm disorders caused by the coronary artery occlusion showed that all four metabolites of bonnecor possessed the antiarrhythmic activity. Metabolite 4 proved to be the most active on both models of cardiac rhythm disorders.     

A comparative study of the pharmacokinetics and pharmacodynamics of bonnecor]

The pharmacokinetics and pharmacodynamics of bonnecor were studied simultaneously in animals with experimental arrhythmia. It was shown that irrespective of the animal species and individual features of the drug elimination kinetics the level of bonnecor concentration correlated with the antiarrhythmic effect. The data on the excretion of bonnecor and its metabolites in the urine in the dog and man were obtained. The decrease of bioavailability at oral administration of bonnecor was demonstrated to be related to its intensive conversion in metabolite M-I.     

Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk

Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer.     

The comparative characteristics of the safety,immunogenic activity and prophylactic potency of the adult and children types of live influenza vaccine in schoolchildren aged 7-14 years

In Russia for prevention of influenza in children, aged from 3 to 14 years, the children's live influenza vaccine (LIV), based upon A/Leningrad/134/47/57(H2N2) master strain (LIVI) is used. The need for double immunization appears to be one out of the faulties of this preparation. The study was aimed to comparing the safety, immunogenic activity and prevention of influenza by LIV for adults (LIVII) (A/Leningrad/134/17/57(H2N2 master strain) and LIVI in children aged from 7 to 17 years under similar administration schedule. The safety, the preventive efficacy, humoral and secretory immunity were studied. In total 2486 persons, including 539 children, twice inoculated with LIVI, 971 persons once inoculated with LIVII, and 840 treated by placebo were obserbed. From the data of the clinical observations during 7 days after immunization both vaccines appeared to be low reactogenic. The LIVII advantages in induction of the humoral and secretory antibodies in comparison with children's vaccine had been revealed. Both vaccines were highly efficacious, the efficiency of both preparations was more pronounced after serologic correction of the diagnosis. The results obtained permit to recommend the single immunization by the variant of LIV at the base on A/Leningrad/134/17/57/(H2N2) master strain for prevention of influenza in school children.     

Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system

Recently, in-vitro maturation (IVM) of immature human oocytes recovered from non-stimulated follicles has been applied in the treatment of infertility. However, in previous reports, very few embryos cultured in conventional medium have reached the expanded blastocyst stage following in-vitro maturation and fertilization (IVM/IVF). The objective of this study was to investigate whether the developmental competence of human embryos following IVM/IVF could be enhanced by the use of a human ampullary cell co-culture system. Immature human oocytes were aspirated from small follicles at Caesarean section and then cultured in medium containing human menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes were randomly cultured either in conventional culture medium alone or in the co-culture system. Of 48 embryos cultured in conventional medium alone, all arrested at the 2-16- cell stage on day 3 after insemination. Of 46 embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at the 2-16-cell stage. Six embryos (13%) developed to the morula stage. Fourteen embryos (30.4%) developed to expanded blastocysts and two blastocysts were hatching on day 7 after insemination. We conclude that co-culture significantly enhances the development of blastocysts in embryos resulting from IVM/IVF.      

Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization

The development and application of fluorescence in-situ hybridization (FISH) has opened the way for comprehensive studies on numerical chromosome abnormalities in human spermatozoa. FISH can be rapidly applied to large numbers of spermatozoa and thus overcomes the major limitation of karyotyping spermatozoa after penetration of zona-free hamster oocytes. The simultaneous hybridization of two or more chromosome-specific probes to spermatozoa and subsequent detection of the bound probes using different fluorescent detection systems enables two or more chromosomes to be localized simultaneously in the same spermatozoon and provides a technique for undertaking reasonable estimates of aneuploidy. The most commonly used probes are those which bind to the centromeric region of specific chromosomes. Most studies to date have concentrated on estimating aneuploidy in spermatozoa from normospermic men, although reports are beginning to appear on aneuploidy in spermatozoa from subfertile and infertile men. Multi- probe FISH studies have generally reported disomy (hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary evidence that some chromosomes such as X, Y and 21 are predisposed towards higher rates of non-disjunction during spermatogenesis. There are also suggestions of inter-donor variability in aneuploidy frequencies for specific chromosomes, although this requires confirmation in larger studies. While FISH is clearly a powerful technique that has many applications in reproductive medicine, it must also be realized that it does have limitations and the technology itself is still evolving and has yet to be fully validated on spermatozoa.