Molecular Differentiation of Schistosoma japonicum and Schistosoma mekongi by Real-Time PCR with High Resolution Melting Analysis

Human schistosomiasis caused by Schistosoma japonicum and Schistosoma mekongi is a chronic and debilitating helminthic disease still prevalent in several countries of Asia. Due to morphological similarities of cercariae and eggs of these 2 species, microscopic differentiation is difficult. High resolution melting (HRM) real-time PCR is developed as an alternative tool for the detection and differentiation of these 2 species. A primer pair was designed for targeting the 18S ribosomal RNA gene to generate PCR products of 156 base pairs for both species. The melting points of S. japonicum and S. mekongi PCR products were 84.5±0.07℃ and 85.7±0.07℃, respectively. The method permits amplification from a single cercaria or an egg. The HRM real-time PCR is a rapid and simple tool for differentiation of S. japonicum and S. mekongi in the intermediate and final hosts.     

Hydrochemistry of Lake Glubokoe

Results of hydrochemical observations in the summer of 1983 are presented and compared to the data of previous years. Some trends in the changing conditions of the lake over the last fifty years are characterized. Data on the chemical composition of bottom deposits are also reported.     

Estimation of the Microcirculatory Response to the Effect of Cold Helium Plasma

Biophysics - Abstract—This study was aimed at estimating the microcirculatory response to local application of cold helium plasma. Experiments were performed with 20 healthy male Wistar rats,...     

Recombinant human peroxiredoxin VI: preparation and protective properties in vitro

cDNA of human peroxiredoxin VI, one of the recently discovered novel antioxidant proteins, was expressed in Escherichia coli cells. The expression product was obtained in water-soluble form and purified by a two-step chromatographic procedure using DEAE-Sepharose and Sephacryl S-200. According to CD data, the polypeptide chain of the recombinant human peroxiredoxin VI contains 40% -helical region and 30% -structure, which is the same as for native rat peroxiredoxin VI. The protective properties of the recombinant protein determined as its ability to prevent the inactivation of glutamine synthetase from E. coli in a model oxidation system were comparable with the protective properties of native rat peroxiredoxin VI.     

Metabolomics reveal alterations in arachidonic acid metabolism in Schistosoma mekongi after exposure to praziquantel

BackgroundMekong schistosomiasis is a parasitic disease caused by the blood-dwelling fluke Schistosoma mekongi. This disease contributes to human morbidity and mortality in the Mekong region, posing a public health threat to people in the area. Currently, praziquantel (PZQ) is the drug of choice for the treatment of Mekong schistosomiasis. However, the molecular mechanisms of PZQ action remain unclear, and Schistosoma PZQ resistance has been reported occasionally. Through this research, we aimed to use a metabolomic approach to identify the potentially altered metabolic pathways in S. mekongi associated with PZQ treatment.Methodology/Principal findingsAdult stage S. mekongi were treated with 0, 20, 40, or 100 μg/mL PZQ in vitro. After an hour of exposure to PZQ, schistosome metabolites were extracted and studied with mass spectrometry. The metabolomic data for the treatment groups were analyzed with the XCMS online platform and compared with data for the no treatment group. After low, medium (IC₅₀), and high doses of PZQ, we found changes in 1,007 metabolites, of which phosphatidylserine and anandamide were the major differential metabolites by multivariate and pairwise analysis. In the pathway analysis, arachidonic acid metabolism was found to be altered following PZQ treatment, indicating that this pathway may be affected by the drug and potentially considered as a novel target for anti-schistosomiasis drug development.Conclusions/SignificanceOur findings suggest that arachidonic acid metabolism is a possible target in the parasiticidal effects of PZQ against S. mekongi. Identifying potential targets of the effective drug PZQ provides an interesting viewpoint for the discovery and development of new agents that could enhance the prevention and treatment of schistosomiasis.     

Protective influence of phosphocreatine (Neoton) on the neural structures of the heart and brain

In acute experiments on dogs, we demonstrated that local immunogenic injury to the heart resulting from injection of anticardial cytotoxic serum is accompanied by suppression of a vagus-mediated depressor reflex evoked by intracoronary injection of 5 μg veratrine. Preliminary i.v. injection of 250 mg/kg phosphocreatine to a significant extent prevented the development of immunogenic heart injury and served to normalize the cardiogenic depressor reflex (we measured the heart rate, systemic arterial pressure, pressure in the left ventricle, and its first derivative, and also recorded the afferent activity in the cardial branches of the vagus nerve). These data are indicative of a protective effect of phosphocreatine on the receptor and afferent structures in the heart. At the same time, a parallel study of the effects of application of phosphocreatine on the spike activity of single neurons and on evoked potentials in the neocortex of rats showed that phosphocreatine increases the excitability of cortical neurons by facilitating the processes of synaptic transmission. This was manifested in an increase in the frequency of background spike activity of the neurons and in facilitation of the development of epileptiform reactions evoked by surface application of penicillin after preliminary applications of phosphocreatine.