A survey on murine gammaherpesvirus 68 in ticks collected in Slovakia.

Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen that infects murid rodents which serve as hosts for Dermacentor reticulatus and Ixodes ricinus ticks. For the first time, MHV-68 was detected in immature I. ricinus ticks feeding on lizards trapped in Slovakia. Later on, MHV-68 infection was detected in D. reticulatus and Haemaphysalis concinna ticks collected on vegetation, which supported the idea that ticks can acquire the virus from feeding on infected hosts. Here, we report MHV-68 infection, which was detected by nested PCR, in D. reticulatus and I. ricinus adult ticks and I. ricinus nymphs collected in five geographically isolated localities, in west, southwest, south and central Slovakia. Viral incidence in ticks was 46.7% (121/259) without considering the season, site of collection and tick species and their life stage. MHV-68 infection was detected in all five localities investigated and in both tick species. Here, for the first time, we report MHV-68 infection in I. ricinus nymphs collected from the vegetation. The finding of virus in ticks from five separated localities suggested that ticks became infected with MHV-68 via feeding on infected rodents; thus, this virus might be a newfound natural pathogen in ticks.

Herpes simplex viruses type 1 and 2 photoinactivated in the presence of methylene blue transform human and mouse cells in vitro.

Three strains of herpes simplex virus, K17syn- and HSZPsyn+ of type 1 (HSV-1) and USsyn- of type 2 (HSV-2), were photoinactivated in the presence of methylene blue and used to infect 3 cell lines, normal human lung tissue cells (MRC-5), mouse epithelial cells (NIH3T3), and human lung carcinoma cells (A549). The virus titer and phenotype of cells were evaluated to compare the characteristics of normal and carcinoma cells infected with non-syncytial (non-syn) and syncytial (syn) strains of herpes simplex viruses. We found that the cells of both normal cell lines infected with photoinactivated K17syn- and USsyn- but not HSZPsyn+ acquired transformed phenotype accompanied by the presence of virus. Surprisingly, the infection with photoinactivated viruses K17syn- and USsyn- but not HSZPsyn+ resulted in the suppression of the transformed phenotype of A549 cells. Using nested PCR, herpesviral DNA was identified in newly transformed cells and cells that lost the transformed phenotype. The effect of putative herpesvirus-related growth factors (HRGF) produced by cells infected with photoinactivated viruses was quantified and compared. Since methylene blue is currently used in phototherapy of herpetic lesions, these results raise the question of whether such therapy is risky to human health.

Molecular detection of murine gammaherpesvirus 68 (MHV-68) in Haemaphysalis concinna ticks collected in Slovakia.

Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen of murid rodents, which serve as hosts to Haemaphysalis concinna ticks. The occurrence of MHV-68 was investigated in a total of 47 H. concinna adult ticks collected on the vegetation in Gabcíkovo, situated in south-western Slovakia (47º54´0´´N, 17º35´0´´E), from May 2013 to May 2014. DNA from ticks was purified and screened by nested PCR targeting ORF50 of MHV-68 and the copy number of virus genome in ticks was determined by a real-time PCR assay specific for ORF65. The MHV-68 incidence in questing ticks was 38.3% (18/47) and the virus genome copy number per tick varied from 2x102 to 9.6x103. In this study, MHV-68 was documented for the first time in H. concinna ticks. Results expand previous data describing the occurrence of MHV-68 in Ixodes ricinus and Dermacentor reticulatus ticks collected in Slovakia, supporting the hypothesis that MHV-68 might be a newfound pathogen in ticks.

Characterization of acetaminophen toxicity in human kidney HK-2 cells.

Acetaminophen (APAP) overdose causes liver injury, but in some cases it is associated also with renal impairment. While several studies exist in relation to acetaminophen nephrotoxicity, no reports have been published describing intracellular changes related to APAP nephrotoxicity in vitro. Because proximal tubular cells are considered to constitute a secondary site of drug-induced injury after hepatocytes, our study's aim was to estimate the toxicity in the human HK-2 cell line. We used a range of APAP concentrations (1-10 mM) to examine toxicity in the cells (1-48 h). We evaluated cell viability using the WST-1 and LDH tests. Cells impairment was also determined by monitoring ROS production, glutathione levels. We proved that HK-2 cells are able to metabolize acetaminophen. We observed moderate impairment of cells already after 1 h of treatment based on a finding of increased ROS production and decreased cell viability. After 24 h, the results showed significant cellular impairment at all tested concentrations except for 1 mM APAP, but no glutathione depletion was found. We conclude that HK-2 cells are susceptible to acetaminophen toxicity but, unlike hepatocytes, it might be not linked to glutathione depletion.

Strong cooperativeness in the mononuclear iron(II) derivative exhibiting an abrupt spin transition above 400 K.

The spin crossover system, [Fe(bzimpy)(2)](ClO(4))(2).0.25H(2)O, was reinvestigated above room temperature (bzimpy = 2,6-bis(benzimidazol-2-yl)pyridine). The system exhibits an abrupt low-spin to high-spin transition at T(c) = 403 K. Liberation of a fractional amount of water does not affect the spin crossover: the system is perfectly reversible with a hysteresis width of DeltaT = 12 K. The existence of the hysteresis at such high temperature determines that the lowest limit of the solid-state cooperativity parameter is J/k > 403 K despite long iron(II) separations (10 A). The high cooperativeness has been assigned to a perfect pi-stacking of the benzimidazole rings in the crystal lattice at a distance as short as 3.6 A. Variable-temperature IR data and the heat capacity measurements match well the magnetic data. The thermodynamic properties are DeltaH = 17 kJ mol(-)(1), DeltaS = 43 J K(-)(1) mol(-)(1), so that the entropy of the spin transition shows a considerable contribution from the molecular vibrations. A theoretical model has been applied in fitting the magnetic data along the whole hysteresis path. A statistical distribution of the cooperativity parameter led to the feature that angled walls of the hysteresis loop are well reproduced.

Haemocompatibility of segmented polyurethanes investigated in vivo.

Samples of segmented polyurethanes differing in composition and in surface morphology were introduced into the left ventricles of hearts of goats for 72 h. After removal of the samples, their surface and the surface of the heart endothelium were evaluated visually with respect to the formation of thrombi. Differences in the interaction of the individual polyurethanes with blood were examined by XPS photoelectron spectroscopy, SEM, and by infrared (i.r.) reflexion spectroscopy. The results suggest ways for improving the haemocompatibility of the surfaces of polyurethanes used as parts of the total artificial heart.

Nearly on-line picosecond streak camera diagnostics of the cw mode-locked YAG laser radiation.

An image-converter streak camera incorporating a TV video-recording system interfaced to a computer HP 2100 was used to record and instantly display the processed shape of a picosecond laser pulse. The output versus input exposure response curve linearity of the whole system was verified over a dynamic range of at least 10. Performance testing of the system was done using a cw mode-locked YAG laser.