Synthesis,Structural Characterization and Antimicrobial Evaluation of Ruthenium Complexes with Heteroaromatic Carboxylic Acids

The antibacterial and antibiofilm activities of two new ruthenium complexes against E. coli, S. aureus, P. aeruginosa PAO1 (laboratory strain) and P. aeruginosa LES B58 (clinical strain) were evaluated. Complexes, mer‐[Ru^III(2‐bimc)₃] ? H₂O ( 1 ) and cis‐[Ru^IVCl₂(2,3‐pydcH)₂] ? 4H₂O ( 2 ), were obtained using aromatic carboxylic acid ligands, namely, 1H‐benzimidazole‐2‐carboxylic acid (2‐bimcH) and pyridine‐2,3‐dicarboxylic acid (2,3‐pydcH₂). Compounds were physicochemically characterized using X‐ray diffraction, Hirshfeld surface analysis, IR and UV/VIS spectroscopies, as well as magnetic and electrochemical measurements. Structural characterization revealed that Ru(III) and Ru(IV) ions in the complexes adopt a distorted octahedral geometry. The intermolecular classical and weak hydrogen bonds, and π???π contacts significantly contribute to structure stabilization, leading to the formation of a supramolecular assembly. Biological studies have shown that the Ru complexes inhibit the growth of bacteria and biofilm formation by the tested strains and the complexes seem to be a potential as antimicrobial agents.     

Species composition of semi-natural mesic grasslands as a factor influencing the methane yield of plant biomass (Central Europe)

Semi-natural lowland and mountain mesic meadows are grasslands rich in species, and their conservation status depends on treatments such as mowing or grazing livestock. In many countries, the condition of grasslands is deteriorating because of their inappropriate use or abandonment. This study aimed to determine the effects of the species composition of plant communities and functional plant groups on the methane yield from biomass harvested from mesic grasslands in the Sudetes Mountains. Biogas potential analysis was performed based on biomass samples collected from Poland and the Czech Republic. The biogas potential was determined in 40 day-long batch anaerobic digestion tests. The average methane yield obtained from the biomass was 246 ± 16 NL CH₄ kg^?1 VS, whereas the methane yield per hectare was 870 ± 203 m³ CH₄ ha^?1. Plant communities comprising different dominant species had no effect on the methane yield but affected the methane yield per hectare. Additionally, the species composition of grasslands with a higher percentage of forbs had lower biomass yield, resulting in lower methane yields per hectare. The continuity of the low-intensity management of mountain grassland, which can be provided by the utilization of their biomass for bioenergy production, sustains high biodiversity and ensures appropriate meadow conservation.     

TRPM8-independent menthol-induced Ca2+ release from endoplasmic reticulum and Golgi

Menthol, a secondary alcohol produced by the peppermint herb, Mentha piperita, is widely used in the food and pharmaceutical industries as a cooling/soothing compound and odorant. It induces Ca2+ influx in a subset of sensory neurons from dorsal root and trigeminal ganglia, due to activation of TRPM8, a Ca2+-permeable, cold-activated member of the TRP superfamily of cation channels. Menthol also induces Ca2+ release from intracellular stores in several TRPM8-expressing cell types, which has led to the suggestion that TRPM8 can function as an intracellular Ca2+-release channel. Here we show that menthol induces Ca2+ release from intracellular stores in four widely used cell lines (HEK293, lymph node carcinoma of the prostate (LNCaP), Chinese hamster ovary (CHO), and COS), and provide several lines of evidence indicating that this release pathway is TRPM8-independent: 1) menthol-induced Ca2+ release was potentiated at higher temperatures, which contrasts to the cold activation of TRPM8; 2) overexpression of TRPM8 did not enhance the menthol-induced Ca2+) release; 3) menthol-induced Ca2+ release was mimicked by geraniol and linalool, which are structurally related to menthol, but not by the more potent TRPM8 agonists icilin or eucalyptol; and 4) TRPM8 expression in HEK293 cells was undetectable at the protein and mRNA levels. Moreover, using a novel TRPM8-specific antibody we demonstrate that both heterologously expressed TRPM8 (in HEK293 cells) and endogenous TRPM8 (in LNCaP cells) are mainly localized in the plasma membrane, which contrast to previous localization studies using commercial anti-TRPM8 antibodies. Finally, aequorin-based measurements demonstrate that the TRPM8-independent menthol-induced Ca2+ release originates from both endoplasmic reticulum and Golgi compartments.     

Determination of treosulfan in plasma and urine by HPLC with refractometric detection; pharmacokinetic studies in children undergoing myeloablative treatment prior to haematopoietic stem cell transplantation

A direct and selective HPLC method with refractometric detection was worked out for determination of treosulfan in plasma and urine of children. Before injection onto reverse phase column plasma samples with treosulfan and barbital (I.S.) were clarified using filtration. The mobile phase was composed of phosphate buffer, pH 5 and acetonitrile. The linear range of the standard curve of treosulfan spanned concentrations of 10.0-2000.0 microg/ml and 50.0-10000.0 microg/ml in plasma and urine, respectively, and covered the levels found in biological fluids after infusion of the drug. The limit of detection amounted to 5 microg/ml for plasma and 25 microg/ml for urine. Intra- and inter-day precision and accuracy of the measurement fulfilled analytical criteria accepted in pharmacokinetic studies. Recovery of treosulfan as well as stability in biological fluids was also calculated. The validated method was successfully applied in pharmacokinetic studies of treosulfan administered to children prior to haematopoietic stem cell transplantation. Differences between pharmacokinetics of treosulfan in children and adults were also studied.     

Potential relationship between glutathione metabolism and flocculation in the yeast Kluyveromyces lactis

Reduced glutathione (GSH) is involved in biochemical and physiological processes in cells. Flocculation is an important mechanism in microorganisms. The present study concerned the potential relationship between GSH metabolism and flocculation. Two yeast strains, a flocculent (Kluyveromyces lactis 5c) and a nonflocculent (Kluyveromyces lactis 5a) strain, were used. The level of intracellular GSH measured during the growth period was significantly higher in the nonflocculent than in the flocculent strain; in contrast, the flocculent strain exhibited brighter staining of vacuoles than the nonflocculent strain when observed using epifluorescence microscopy. Compounds acting either on flocculation (EDTA, galactose) or on GSH metabolism (buthionine sulfoximine, and N-acetylcysteine) were tested on the flocculent strain during the growth period. Both EDTA and galactose fully inhibited flocculation and induced GSH overproduction of 58% and 153%, respectively. Buthionine sulfoximine decreased GSH level by 76% but had no effect on flocculation; N-acetylcysteine increased the GSH level and flocculation by 106% and 41%, respectively. Combination of EDTA and N-acetylcysteine produced similar effects than with each of them. Combination of galactose and N-acetylcysteine increased the GSH level but decreased flocculation. These results demonstrated that GSH homeostasis is linked to the flocculation mechanism. A hypothesis related to stress is given.     

The role of intraspecific competition in the dispersal of an invasive fish

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Human Sperm Characteristics with Regard to Cobalt,Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

Biological Trace Element Research - We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their...     

Bone marrow angiogenesis and proliferation in B-cell chronic lymphocytic leukemia

OBJECTIVE: To assess angiogenesis and the proliferative activity of bone marrow in patients with chronic lymphocytic leukemia (CLL) in relation to the bone marrow infiltration pattern. STUDY DESIGN: Bone marrow samples were obtained by trephine biopsy from 46 patients with B-cell CLL (B-CLL). Infiltration pattern was diffuse in 20 patients and nondiffuse--i.e., nodular, interstitial or mixed--in the remaining 26 patients. Ten normal bone marrow samples were used as a control group. Studies were carried out by immunohistochemical staining of paraffin-embedded bone marrow samples. Angiogenesis was assessed in the zones of highest vascular density (hot spots), visualized by the expression of endothelial antigen CD34 and expressed as a number of microvessels per high-powerfield (hpf) (final magnification, 400x). Proliferative activity was estimated by the expression of nuclear protein Ki-67, cyclin A and mean number of nucleolar organizer regions (AgNORs). RESULTS: Microvessel density was higher in B-CLL marrow than in normal marrow (30.1 and 16.44 per hpf, respectively) and was higher in the diffuse than nondiffuse pattern (33.6 and 27.5 per hpf, respectively). B-CLL bone marrow also showed higher proliferative activity, as assessed by mean number of AgNORs, than did normal marrow (1.52 and 1.25, respectively) and a higher mean percentage of cyclin A-positive cells (7.5 and 6.8, respectively). In contrast, mean Ki-67 expression was similar in B-CLL and the control group. Mean AgNORs number, Ki-67 and cyclin A-positive cell percentage were significantly higher in B-CLL marrow with a diffuse as compared to nondiffuse involvement pattern (AgNORs, 1.75 and 1.35; cyclin A, 9.27% and 3.95%; Ki-67, 34.9% and 23.3%, respectively). CONCLUSION: Our results indicate enhancement of bone marrow angiogenesis in B-CLL and a relationship between microvessel density and the bone marrow infiltration pattern. The study points also to a possible relationship between the bone marrow infiltration pattern and proliferative activity of bone marrow cells.