Analysis of genetico-demographic structure of rural populations living near the Semipalatinsk nuclear test site]

Rural populations neighboring the Semipalatinsk nuclear test site were used as a model to develop and test an integrated population-genetic approach to analysis of the medical genetic situation and environmental conditions in the areas studied. The contributions of individual factors of population dynamics into the formation of the genetic load were also assessed. The informative values of some genetic markers were estimated. Based on these estimates, a mathematical model was constructed that makes it possible to calculate numerical scores for analysis of the genetic loads in populations differing in environmental exposure.     

Night sleep structure in the cases of disturbance of blood supply in the internal carotid artery pool

The study examines correlation between the degree of stenosis of the internal carotid artery (ICA) and the night sleep parameters. The possible neurophysiological mechanisms of sleep disorder in blood flow disturbances in the carotid system are also discussed. Twenty-four patients (19 men and 5 women) were examined, including 6 cases of 50% ICA stenosis, 7 cases of 50–70% ICA stenosis; and 11 cases of ICA occlusion. A polygraphic study of night sleep was conducted and the sleep stages were analyzed. The patients filled in the quality of sleep questionnaire with the presence of the somnolence scoring system. In order to assess brain perfusion, single-photon emission CT imaging of the brain was performed. The results of the study showed that the night sleep structure in the cases of 50% ICA stenosis was unchanged: all the sleep phases and stages whose quantitative parameters corresponded to the reference normal data were recorded, or only stage II sleep representation declined; in the cases of 50–70% ICA stenosis, predominantly stage II sleep and slow-wave sleep were compromised; in patients with ICA occlusion, slow-wave sleep and REM-sleep (45% of cases) were disturbed.     

Dual fluorophore-nitroxide probes for analysis of vitamin C in biological liquids

A new method for quantitative analysis of vitamin C in biological and chemical liquids was proposed. The method is based on the use of dual molecule consisting of a fluorescent chromophore and a nitroxide radical. In the dual molecule, the nitroxide acts as a quencher of the fluorescence of the chromophore fragment. Reduction of the nitroxide fragment by ascorbic acid results in decay of ESR signal and enhancement of the fluorescence. By performing the series of pseudo-first-order reactions between the dual molecule and ascorbic acid and consequent plotting rate constants versus ascorbic acid concentrations the calibration curves for the vitamin C analysis were obtained. Variations of chemical structure of fluorophore and nitroxide fragments allow to regulate fluorescent properties and redox potentials of the dual molecules. The proposed fluorophore-nitroxide hybrids retain all features of the spin labels and fluorescence probes gaining new advantages for monitoring redox reactions and radical processes by two independent techniques: ESR and steady-state fluorescent spectroscopy. The method was applied to the vitamin C analysis in commercial fruit juices.     

Thermotoga neopolitina gene cluster, participating in degradation of starch and maltodextrins: expression of aglB and aglA gene in Escherichia coli, properties of recombinant enzymes

The aglB and aglA genes from the starch/maltodextrin utilization gene cluster of Thermotoga neapolitana were subcloned into pQE vectors for expression in Escherichia coli. The recombinant proteins AglB and AglA were purified to homogeneity and characterized. Both enzymes are hyperthermostable, the highest activity was observed at 85 degrees C. AglB is an oligomer of identical 55-kDa subunits capable of aggregation. This protein hydrolyses cyclodextrins and linear maltodextrins to glucose and maltose by liberating glucose from the reducing end of the molecules, and it is a cyclodextrinase with alpha-glucosidase activity. The pseudo-tetrasaccharide acarbose, a potent alpha-amylase and alpha-glucosidase inhibitor, does not inhibit AglB but, on the contrary, acarbose is degraded quantitatively by AglB. Recombinant AglB is activated in the presence of CaCl2, KCl, and EDTA, as well as after heating of the enzyme. AglA is a dimer of two identical 54-kDa subunits, and it hydrolyses the alpha-glycoside bonds of disaccharides and short maltooligosaccharides, acting on the substrate from the non-reducing end of the chain. It is a cofactor-dependent alpha-glucosidase with a wide action range, hydrolysing both oligoglucosides and galactosides with alpha-link. Thereby, the enzyme is not specific with respect to the configuration at the C4 position of its substrate. For the enzyme to be active, the presence of NAD+, DTT, and Mn2+ is required. Enzymes AglB and AglA supplement one another in substrate specificity and ensure complete hydrolysis to glucose for the intermediate products of starch degradation.     

Mechanism of the serotonin effect on motility of the duodenum,ileum, and jejunum in awake rabbits

I. v. administration of serotonin to alert rabbits produced a phasic change of contractile activity of duodenum, ileum, and jejunum including excitatory and inhibitory components. It is shown that stimulation of the small bowel motility is caused by serotonin activation of non-cholinergic excitatory mechanism with participation of effector cholinergic neurones. The initial suppression of the motility is caused by participation of nonadrenergic noncholinergic inhibitory mechanism, and the secondary inhibition of contractile activity of a small bowel with serotonin has an adrenergic nature.     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

Direct intracardiac injection of umbilical cord-derived stromal cells and umbilical cord blood-derived endothelial cells for the treatment of ischemic cardiomyopathy

The development of new therapeutic strategies is necessary to reduce the worldwide social and economic impact of cardiovascular disease, which produces high rates of morbidity and mortality. A therapeutic option that has emerged in the last decade is cell therapy. The aim of this study was to compare the effect of transplanting human umbilical cord-derived stromal cells (UCSCs), human umbilical cord blood-derived endothelial cells (UCBECs) or a combination of these two cell types for the treatment of ischemic cardiomyopathy (IC) in a Wistar rat model. IC was induced by left coronary artery ligation, and baseline echocardiography was performed seven days later. Animals with a left ventricular ejection fraction (LVEF) of ≤40% were selected for the study. On the ninth day after IC was induced, the animals were randomized into the following experimental groups: UCSCs, UCBECs, UCSCs plus UCBECs, or vehicle (control). Thirty days after treatment, an echocardiographic analysis was performed, followed by euthanasia. The animals in all of the cell therapy groups, regardless of the cell type transplanted, had less collagen deposition in their heart tissue and demonstrated a significant improvement in myocardial function after IC. Furthermore, there was a trend of increasing numbers of blood vessels in the infarcted area. The median value of LVEF increased by 7.19% to 11.77%, whereas the control group decreased by 0.24%. These results suggest that UCSCs and UCBECs are promising cells for cellular cardiomyoplasty and can be an effective therapy for improving cardiac function following IC.     

Co-expression of the Thermotoga neapolitana aglB gene with an upstream 3'-coding fragment of the malG gene improves enzymatic characteristics of recombinant AglB cyclomaltodextrinase

A cluster of Thermotoga neapolitana genes participating in starch degradation includes the malG gene of sugar transport protein and the aglB gene of cyclomaltodextrinase. The start and stop codons of these genes share a common overlapping sequence, aTGAtg. Here, we compared properties of expression products of three different constructs with aglB from T. neapolitana. The first expression vector contained the aglB gene linked to an upstream 90-bp 3'-terminal region of the malG gene with the stop codon overlapping with the start codon of aglB. The second construct included the isolated coding sequence of aglB with two tandem potential start codons. The expression product of this construct in Escherichia coli had two tandem Met residues at its N terminus and was characterized by low thermostability and high tendency to aggregate. In contrast, co-expression of aglB and the 3'-terminal region of malG (the first construct) resulted in AglB with only one N-terminal Met residue and a much higher specific activity of cyclomaltodextrinase. Moreover, the enzyme expressed by such a construct was more thermostable and less prone to aggregation. The third construct was the same as the second one except that it contained only one ATG start codon. The product of its expression had kinetic and other properties similar to those of the enzyme with only one N-terminal Met residue.     

Peculiarities of the beam-plasma discharge development in high-pressure gas and prospects of its application

The dynamics of a stationary beam-plasma discharge at the neutral gas pressure of 10⁻³-1 Torr is investigated. Three discharge modes have been revealed: two of them are characterized by novel properties and have not been studied as of yet. Dissipative instabilities with different increments have been found. The generation of ion flows has been studied and the experiments on “dry” cleaning of the metal specimen surfaces using them have been carried out. The pressure ranges in a neutral gas at which the discharge can be efficiently applied in nonequilibrium plasma chemistry are given.     

Stress-induced inhibition of the ileal, caecal, and colonic contractile activity in rabbits]

In alert rabbits, immobilisation stress decreased the spike burst rate and amplitude in ileum, caecum, and colon for 20 min. Following beta-adrenoceptor blockade, the contractile activity suppression was aggravated. The stress seems to lead to suppression of the ileal, caecal, and colonic contractile activity for up to 40 min which is unrelated to adrenergic inhibition of the smooth muscle activity mediated by beta-adrenoceptors.