Mineralogical and geochemical features of the Manus Basin hydrothermal sulfide ores, Bismarck Sea

Paragenetic mineral assemblages have been established based on mineralogical, chemical, and isotope (S, Pb) studies, and the sequence of deposition has been defined in hydrothennal sulfide structures in a typical back-arc basin. The ores in the Manus basin have a prominent Zn specialization (sphalerite, würtzite, and fe-sphalerite). An association of Fe-spbalerite and galena with Ag sulfosalts is noted that is not characteristic of typical midocean ridge hydrothennal systems. The average 34S in the sulfide minerals is 3.5%o, which corresponds to the medium-temperature sphalerite stage in hydrothermal mineral fonnation. It is suggested that the metal source is located in the relatively acid rocks of the island-arc tholeiitic series and possibly in sediments

The system of osteoprotegrin (OPG)/ligand of NF-kB receptor activator (RANKL) in patients with diabetes mellitus, mediacalcinosis and obliteratingatherosclerosis of lower leg arteries

Aim. To study the OPG/RANKL system in patients with diabetes mellitus, mediacalcinosis and obliterating atherosclerosis of lower leg arteries. Materials and methods. The study enrolled 70 patients including 20 with manifest diabetic neuropathy (DN) and mediacalcinosis of lower leg arteries(group 1). 29 patients with diabetes mellitus (DM) and clinical manifestations of obliterating atherosclerosis of lower leg arteries comprised group 2. Thecontrol group 3 consisted of 30 subjects without disturbances of carbohydrate metabolism. Immunoassays with Alkphase-B (Metra biosystems, USA),Osteoprotegrin (Biomedica, Austria), and sRANKL(Biomedica, Austria) kits were used to detect serum markers of bone formation (alkaline phosphatase(AP), OPG, and RANKL respectively). The patients underwent examination by digital X-ray of affected joints in frontal and lateral projections using anAxiom Iconos R 200 apparatus (Siemens, Germany). Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (Expert 1188,Lunar, USA). Ultrasound duplex scanning of lower leg arteries was performed with Sonoc-5500 (Agilent, USA). Results. OPG levels in diabetic patients were significantly higher than in controls (

Ribonucleolytic activity of mycoplasmas

Mycoplasmas are incapable of de novo synthesis of nucleotides and must therefore secrete nucleases in order to replenish the pool of nucleic acid precursors. The nucleolytic activity of mycoplasmas is an important factor in their pathogenicity. Bacterial ribonucleases (RNases) may produce a broad spectrum of biological effects, including antiviral and antitumor activity. Mycoplasma RNases are therefore of interest. In the present work, the capacity of Acholeplasma laidlawii and Mycoplasma hominis for RNase synthesis and secretion was studied. During the stationary growth phase, these organisms were found to synthesize Mg2+-dependent RNases, with their highest activity detected outside the cells. Localization of A. laidlawii RNases was determined: almost 90% of the RNase activity was found to be associated with the membrane vesicles. Bioinformational analysis revealed homology between the nucleotide sequences of 14 Bacillus subtilis genes encoding the products with RNase activity and the genes of the mycoplasmas under study. Amino acid sequences of 4 A. laidlawii proteins with ribonuclease activity and the Bsn RNase were also established. © 2014 Pleiades Publishing, Ltd

The effect of Spo0A and AbrB proteins on expression of the genes of guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis recombinant strains

Guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus are actively secreted under phosphate starvation by recombinant strains of Bacillus subtilis with native regulatory systems and by strains defective in some proteins of the Spo0A phosphorylation pathway. The level of expression of ribonuclease genes has been shown to increase approximately sixfold in recombinant strains with mutation in the spo0A gene and threefold in the spo0A/abrB mutants, as compared with native strains. These results demonstrate that the Spo0A protein regulates the production of ribonucleases and thus acts as a repressor, while the AbrB protein is an activator of expression of the genes encoding ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells. © 2007 Pleiades Publishing, Ltd

The effect of Spo0A and AbrB proteins on expression of the genes of guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis recombinant strains

Guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus are actively secreted under phosphate starvation by recombinant strains of Bacillus subtilis with native regulatory systems and by strains defective in some proteins of the Spo0A phosphorylation pathway. The level of expression of ribonuclease genes has been shown to increase approximately sixfold in recombinant strains with mutation in the spo0A gene and threefold in the spo0A/abrB mutants, as compared with native strains. These results demonstrate that the Spo0A protein regulates the production of ribonucleases and thus acts as a repressor, while the AbrB protein is an activator of expression of the genes encoding ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells. © 2007 Pleiades Publishing, Ltd

The effect of Spo0A and AbrB proteins on expression of the genes of guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis recombinant strains

Guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus are actively secreted under phosphate starvation by recombinant strains of Bacillus subtilis with native regulatory systems and by strains defective in some proteins of the Spo0A phosphorylation pathway. The level of expression of ribonuclease genes has been shown to increase approximately sixfold in recombinant strains with mutation in the spo0A gene and threefold in the spo0A/abrB mutants, as compared with native strains. These results demonstrate that the Spo0A protein regulates the production of ribonucleases and thus acts as a repressor, while the AbrB protein is an activator of expression of the genes encoding ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells. © 2007 Pleiades Publishing, Ltd