Effects of phytoadaptogens on biorhythms of indicators of the hemostasis system in dogs]

Circadian rhythms in dog hemostasis were studied in winter. The animals were fed with eleutherococcus and liquorice extracts with bread in different time of the day. Hemostatic investigations revealed chronosensitivity of hemostasis to the phytoadaptogens which is important for assessment of their chronopharmacological properties and prospects of their use.     

Roles of neuraminidase in the initial stage of influenza virus infection

We propose a concept that neuraminidase (NA) promotes virus entry into target cells during the initial stage of viral infection, in addition to the generally accepted concept that influenza virus NA promotes the release of progeny virus from a host cell at the final stage of viral replication. When NA activity was inhibited with specific inhibitors such as zanamivir and oseltamivir carboxylate, infection efficiency of the virus to MDCK and A549 cells was reduced to approximately 1/4 and 1/8, respectively. NA inhibitors did not significantly affect virus binding and envelope fusion activities, when assessed using an erythrocyte and virus system. Since the initial stage of viral infection involves binding of the virus to the target cell, virus entry into an endosome and envelope fusion with the endosomal membrane, our results indicated that NA inhibitors interfered with the virus entry step. Thus, NA is thought to promote virus entry, and thereby enhances infection efficiency.     

Effect of ethyl alcohol on selected parameters of the hemostasis system in vitro]

Alcohol produces several disorders in all components of hemostasis system. However, its mechanism of action is not clear. Therefore, an effect of ethyl alcohol on the selected parameters of both platelet and plasma hemostasis has been examined in vitro. Blood aggregation induced by ADP and PAF and platelet-leucocytic aggregates have been determined in vitro in the group of 45 healthy volunteers. Out of plasma parameters the selected factors of blood coagulation and fibrinolysis have been examined. Results suggest that the examined concentrations of ethyl alcohol mainly affect platelet function decreasing platelet aggregation. Alcohol does not affect significantly blood coagulation and fibrinolysis occurring in vitro.     

Evaluation of selected indicators of the renal proximal tubule function in patients treated with gentamicin]

The study aimed at evaluating proximal renal tubule function in patients with nephrolithiasis and chronic pyelonephritis, and in patients with infectious diseases treated with gentamicin. The study involved 2 groups of patients: group A--17 patients with nephrolithiasis and chronic pyelonephritis and group B--30 patients with other infectious diseases (pneumonia, biliary tract infections) but with normal glomerular filtration rate. Patients from both groups were treated with gentamicin in a daily dose of 2-3 mg/kg for 7-10 days. Serum and urine creatinine levels were assayed in all patients prior to, 2-3, 7, 10 days, and after the treatment. Patients assigned to group B were divided into two subgroups: B1 included 15 patients with normal beta 2-microglobulinuria, and B2 15 patients with increased renal loss of beta 2-microglobulin and decreased tubular reabsorption of this protein. Significant increase in beta 2-microglobulinuria was seen on the third day of therapy, the decrease in the tubular reabsorption and glomerular filtration rate were noted in all patients on the seventh day of gentamicin administration. Beta 2-microglobulinuria was significantly higher in patients from groups A and B2 in comparison with group B1 in which no dysfunction of the proximal renal tubule was present before gentamicin therapy. A degree of beta 2-microglobulinuria is an early and sensitive indicator of gentamicin nephrotoxicity. The risk of nephrotixic symptoms is particularly obvious in patients with deteriorated function of renal proximal tubuli before the treatment with gentamicin.     

Reference values of the hemostasis system indices in cosmonauts

The values of 11 diagnostically significant hemostasis system indices were determined during the preflight (30–45 days before start) clinical and physiological examination of 39 cosmonauts aged 35 to 54 years, who were the members of the main and backup crews of missions to the International Space Station (ISS) during the period from 2007 to 2014. Since most of the cosmonauts performed several flights over this period and were repeatedly included in backup crews, each of them underwent examinations one to five times. The reference values were calculated for each of the studied indices. It was found that the reference ranges for the parameters indicative of the integral pro- and anticoagulant and fibrinolytic blood plasma potential were somewhat narrowed and close to the boundaries of general population ranges, which indicates that the cosmonauts had a relatively decreased procoagulant potential and increased regulative potential of the hemostasis system. This was probably due to the criteria of selection, physical training status, and emotional status of crew members during the preflight professional activity, when adaptive changes against stressinducing effects occur in the body. The cosmonauts who underwent strict medical examination may also have some genetic features in which they differ from the general population and which provide higher body resistance and more rapid adaptation processes.     

Laboratory diagnosis of the status of the hemostasis system

Activators of fibrinogen, prothrombin and protein C isolated from venoms of Agkistrodon halys halys and Echis multisquamatus may be used as a tool both for thrombosis investigations in the model systems and for diagnostic in the clinical practice. The complex of diagnostic tests developed on the base of these activators allows to characterize the haemostatic system at different pathologies and as well as to determine the unbalance between separate components of haemostasis. The tests are approved on plasma of patients with heart diseases, ulcers, nephrites, hestoses etc. The tests are sensitive, informative, easy to use and do not require an additional equipment. They have no analogues in Ukraine.     

Spectrophotometric study of the initial stage of lymphocyte transformation

Results are presented of temporal variations of light current which passed through mouse lymphocyte suspension at introduction of phytohemagglutinin mitogen or concentrated cell suspension on liquid surface. Based on comparing the calculated time of phytohemagglutinin molecules diffusion, velocity of lymphocyte precipitation and recorded time of the system response a hypothesis is advanced concerning the existence of an ordered structure formed by cells in suspension, and a relay--race transmission of surface disturbance deep into the volume.     

Imitating the initial evolutionary stage of a tail ornament

Abstract.— Costs of a sexual ornament in its early evolutionary form and the relationship between these costs and individual condition may be an important influence in the likelihood of possible evolutionary mechanisms involved in the evolution of this ornament. We reconstructed the tail shape in hypothetical ancestors of recent hirundines (Aves: Hirundinidae), from which the elongation of tail feathers under sexual selection might have begun. By elongating the tail in sand martins ( Riparia riparia , Hirundinidae), we simulated the early evolution of a long forked tail–the typical ornament of male hirundines. Birds with initial ornament captured smaller insects than controls, which suggests that this ornament imposed a cost in terms of impaired foraging. Furthermore, birds with naturally longer tails were better able to cope with initial ornament than naturally short-tailed birds. If length of tail in sand martins indicates the quality of individuals, our results suggest higher costs of this initial ornament for poorer than for higher quality individuals. We discuss the potential role of the handicap principle and other mechanisms in early evolution of a tail ornament.     

Platelet link of the hemostasis system in modeling chronic stress situations

Changes in the morphofunctional state of platelets were studied in a model of emotional-painful stress that was reproduced in rabbits weighing from 2.5 to 3 kg by the irregular action of a low-intensity electric current. Platelets were isolated from venous blood by successive centrifugation. The obtained material was investigated supravitally using the luminescent dye acridine orange, tests with siliconized glass, and by electron microscopy. Uncompensated negative charges of glycosaminoglycans, Ca²⁺, activities of ATPase, alkaline phosphatase, adenylate cyclase, cyclic nucleotide phosphodiesterase, and monoamine oxidase were detected cytochemically. As a result, morphofunctional equivalents of the destabilizing effect of a chronic stress situation on blood plates were established, and membranotropic and receptor-mediated mechanisms of its implementation were analyzed.     

Arterio-venous differences in the vascular and thrombocytic indices of the hemostasis system

Arterio-venous difference in the functional activity of platelets and vascular wall was studied in Wistar rats. It was found that platelets, unlike leukocytes, were functionally more active in arterial than in venous blood. Athrombogenic activity of arteries was higher than that of veins.     

Characterization of fibrillation process of alpha-synuclein at the initial stage

α-Synuclein is the major component of the filamentous Lewy bodies and Lewy-related neurites, neuropathological hallmarks of Parkinson’s disease. Although numerous studies on α-synuclein fibrillation have been reported, the molecular mechanisms of aggregation and fibrillation at the initial stage are still unclear. In the present study, structural properties and propensities to form fibrils of α-synuclein at the initial stage were investigated using 2D ¹H-¹⁵N NMR spectroscopy, electron microscope, and small angle X-ray scattering (SAXS). Observation of the 2D ¹H-¹⁵N HSQC spectra indicated significant attenuation of many cross peak intensities in the regions of KTKEGV-type repeats and the non-Aβ component of Alzheimer’s disease amyloid (NAC), suggesting that these regions contributed fibril formation. Oligomerization comprising heptamer was successfully monitored at the initial stage using the time-dependent SAXS measurements.     

Structural-functional state of platelets at the initial stage of aggregation

ADP-induced changes of light transmission of platelet suspension were studied with a laser aggregometer at concentration variation of both cells and aggregation agents. It was shown that a decrease of light transmission of platelet suspension was due to structure-morphological changes of platelets and pseudopodia formation. An investigation method of platelet aggregation with a small content of cells in the solution permits to fix distinctly the stages of the platelet structural states in the processes of stimulation and aggregation.     

Involvement of cyclic GMP in the initial stage of hepatocytes proliferation.

A transient rise in cyclic guanosine 3' : 5' monophosphate (c-GMP) in the liver was observed in rats in vivo 10--20 min after partial hepatectomy. A similar increase in c-GMP in the liver was also found in rats in vivo 15 min after infusion of TGH solution (a mixture of triiodothyronine, glucagon, and heparin). In both cases, inductions of ornithine decarboxylase [EC 4.1.1.17] and tyrosine aminotransferase [EC 2.6.1.5] were found 4 hr after the beginning of the experiments. Later, 22 hr after the surgical intervention or hormone infusion, thymidine kinase [EC 2.7.1.21] was activated and liver slices were able to incorporate [3H]thymidine into DNA. These biochemical phenomena were observed commonly in regenerating liver as well as in the liver of rats infused with TGH solution. c-GMP, but not c-AMP, could induce ornithine decarboxylase and tyrosine aminotransferase in isolated, perfused liver.