Role of macrophages in interferon production]

The role of macrophages in production of interferons (IF) is manysided. They are able to synthesize IFs after any induction. However, the function of macrophages as producers of IFs is not, probably, basic. The levels of IFs produced by them are mainly low. When they are stimulated by inducers of "early" IF the synthesis is performed by intact macrophages whereas with the use of inducers of "late" IF there is always observed joint activity of macrophages and other immunocompetent cells. The main role of macrophages in production of IFs is in regulation of synthesis of these proteins in the host. In addition, they are able to serve as stimulating cells in inducing IF production by the majority of drugs by transmitting information on IF synthesis to lymphocytes. This function of macrophages is not species-specific.     

mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species

Reconstructions of the human-African great ape phylogeny by using mitochondrial DNA (mtDNA) have been subject to considerable debate. One confounding factor may be the lack of data on intraspecific variation. To test this hypothesis, we examined the effect of intraspecific mtDNA diversity on the phylogenetic reconstruction of another Plio- Pleistocene radiation of higher primates, the fascicularis group of macaque (Macaca) monkey species. Fifteen endonucleases were used to identify 10 haplotypes of 40-47 restriction sites in M. mulatta, which were compared with similar data for the other members of this species group. Interpopulational, intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of divergence time and branching order incorporating this variation were substantially different from those based on single representatives of each species. We conclude that intraspecific mtDNA diversity is substantial in at least some primate species. Consequently, without prior information on the extent of genetic diversity within a particular species, intraspecific variation must be assessed and accounted for when reconstructing primate phylogenies. Further, we question the reliability of hominoid mtDNA phylogenies, based as they are on one or a few representatives of each species, in an already depauperate superfamily of primates.      

Ani immunomodulator Hepon inhibits hepatitis C virus replication in human cell cultures in vitro]

Antiviral activity of immunomodulator "Hepon" was evaluated in human cells culture infected with hepatitis C virus. "Hepon" presence protected human cells SW-13 from cytopathogenic effect of hepatitis C virus. Maximum antiviral effect was demonstrated by "Hepon" at concentration 1 mcg/mL. Control antiviral agent reaferon (interferon alfa-2a) was more potent as vitality protecting agent in the case of SW-13 human cells culture. "Hepon" activity is based on changes of cytokins and interferons spectrum so this immunomodulator is expected to be effective against different viruses including herpes virus and encephalocarditis virus.     

Mathematical modeling of ventricular disturbances following atrial fibrillation

The present study presents the results of mathematical and computer modeling of atrial fibrillation and ventricular disturbances following atrial fibrillation. The model is based on the assumption, that electric impulsation arriving on the atrioventricular node during atrial fibrillation is sum N of independent pulse streams with various amplitude-frequency and phase characteristics. With this model it becomes possible to investigate the dependence of nonlinear dynamics of PP and RR intervals on amplitude-frequency and phase characteristics pulse streams. Results of computer experiments are compared with real physiological experiments on rabbits. Identification of model was carried out by means of least-squares procedure.     

The brown adipocyte differentiation pathway in birds: An evolutionary road not taken

Background  

Thermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common white fat adipocytes by having numerous small lipid droplets rather than a single large one, elevated numbers of mitochondria, and mitochondrial expression of the nuclear gene UCP1, the uncoupler of oxidative phosphorylation responsible for non-shivering thermogenesis.     

Mathematical model of heart rate variability

The study presents a mathematical model of non-linear dynamics of the heart rate variability (HRV). The model is based on quantitative characteristics of pulse conduction in the heart conducting system: the delays of sinoatrial (SA) and atrioventricular (AV) pulse conduction and refractors periods of the SA and AV nodes. The model predicts heart rate disturbances in fast electric activity of the atria, increase in the delay of the AV conduction, the critical value of atrial period where transition to non-linear dynamics of the heart rate variability starts. The correlation between indexes of HRV and period of stimulation of atria for 1-contour cardiac control model has been demonstrated.