IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolated from patients with pulmonary tuberculosis in Campinas,Brazil: evidence of intercontinental distribution of strains

Tuberculosis (TB) is a major concern in developing countries. In Brazil, few genotyping studies have been conducted to verify the number of IS6110 copies present in local prevalent strains of Mycobacterium tuberculosis, the distribution and clustering of strains. IS6110 DNA fingerprinting was performed on a sample of M. tuberculosis isolates from patients with AFB smear-positive pulmonary TB, at a hospital in Brazil. The IS6110 profiles were analyzed and compared to a M. tuberculosis database of the Houston Tuberculosis Initiative, Houston, US. Seventy-six fingerprints were obtained from 98 patients. All M. tuberculosis strains had an IS6110 copy number between 5-21 allowing for differentiation of the isolates. Human immunodeficiency virus infection was confirmed in nearly half the patients of whom data was available. Fifty-eight strains had unique patterns, while 17 strains were grouped in 7 clusters (2 to 6 strains). When compared to the HTI database, 6 strains matched isolates from El Paso, Ciudad de Juarez, Houston, and New York. Recently acquired infections were documented in 19% of cases. The community transmission of infection is intense, since some clustered strains were recovered during the four-year study period. The intercontinental dissemination of M. tuberculosis strains is suspected by demonstration of identical fingerprints in a distant country.     

Sperm-FISH analysis and human monitoring: a study on workers occupationally exposed to styrene

Occupational exposure to styrene, a chemical extensively used worldwide, is under investigation for possible detrimental effects on human health, including male reproductive capacity. Aneuploidy in germ cells is the main cause of infertility, abortions and congenital diseases. Fluorescence in situ hybridisation (FISH), is the most efficient cytogenetic molecular technique to date to analyse numerical alterations of chromosomes in spermatozoa. We investigated the frequencies of aneuploidy and diploidy in individuals occupationally exposed to styrene and in healthy unexposed controls. We performed multicolour FISH, using DNA probes specific for the centromeric regions of sex chromosomes and chromosome 2, in decondensed sperm nuclei of samples with normal semen parameters for a total of 18 styrene-exposed subjects and 13 unexposed controls of the same age range. Exposed individuals had worked for at least 2 years during the last 5 years, and continuously for 6 months, in factories producing reinforced plastics. The incidence of aneuploidy and diploidy for the tested chromosomes did not show a statistically significant difference between workers and controls. The exposure to styrene was associated with increased frequencies of nullisomy for sex chromosomes in the group of non-smokers, although only a limited number of subjects belonged to this sub-group. Considering the whole study population, age was associated with an increased frequency of XX disomy, whereas smoking was associated with meiosis II non-disjunction of sex chromosomes. Overall, confounding factors appeared to exert a more important effect than exposure to styrene on numerical chromosome alterations in sperm nuclei of subjects selected for normal semen parameters.     

Effects of in vivo exposure to GSM-modulated 900 MHz radiation on mouse peripheral lymphocytes

The aim of this study was to evaluate whether daily whole-body exposure to 900 MHz GSM-modulated radiation could affect spleen lymphocytes. C57BL/6 mice were exposed 2 h/day for 1, 2 or 4 weeks in a TEM cell to an SAR of 1 or 2 W/kg. Untreated and sham-exposed groups were also examined. At the end of the exposure, mice were killed humanely and spleen cells were collected. The number of spleen cells, the percentages of B and T cells, and the distribution of T-cell subpopulations (CD4 and CD8) were not altered by the exposure. T and B cells were also stimulated ex vivo using specific monoclonal antibodies or LPS to induce cell proliferation, cytokine production and expression of activation markers. The results did not show relevant differences in either T or B lymphocytes from mice exposed to an SAR of 1 or 2 W/kg and sham-exposed mice with few exceptions. After 1 week of exposure to 1 or 2 W/kg, an increase in IFN-gamma (Ifng) production was observed that was not evident when the exposure was prolonged to 2 or 4 weeks. This suggests that the immune system might have adapted to RF radiation as it does with other stressing agents. All together, our in vivo data indicate that the T- and B-cell compartments were not substantially affected by exposure to RF radiation and that a clinically relevant effect of RF radiation on the immune system is unlikely to occur.     

Genetic damage induced by in vitro irradiation of human G0 lymphocytes with low-energy protons (28 keV/microm): HPRT mutations and chromosome aberrations

Cell survival, mutations and chromosomal effects were studied in primary human lymphocytes exposed in G0 phase to a proton beam with an incident energy of 0.88 MeV (incident LET of 28 keV/microm) in the dose range 0.125-2 Gy. The curves for survival and mutations at the hypoxanthine-guanine phosphoribosyl transferase locus were obtained by fitting the experimental data to linear and linear-quadratic equations, respectively. In the dose interval 0-1.5 Gy, the alpha parameters of the curves were 0.42/Gy and 3.6 x 10(-6) mutants/Gy, respectively. The mutation types at the HPRT locus were analyzed by multiplex-PCR in 94 irradiated and 41 nonirradiated clones derived from T lymphocytes from five healthy donors. All clones showed a normal multiplex-PCR pattern and were classified as point mutations. Chromosome aberration data were fitted as a linear function of dose (alpha = 0.62 aberrations per cell Gy(-1)). By irradiating G0 lymphocytes from a single subject with 28 keV/microm protons and gamma rays, an RBE of 6.07 was obtained for chromosome aberrations. An overinvolvement of chromosome 9 relative to chromosome 7 was found in chromosome breaks after chromosome painting analysis.     

Dimerization controls the lipid raft partitioning of uPAR/CD87 and regulates its biological functions

The urokinase-type plasminogen activator receptor (uPAR/CD87) is a glycosylphosphatidylinositol-anchored membrane protein with multiple functions in extracellular proteolysis, cell adhesion, cell migration and proliferation. We now report that cell surface uPAR dimerizes and that dimeric uPAR partitions preferentially to detergent-resistant lipid rafts. Dimerization of uPAR did not require raft partitioning as the lowering of membrane cholesterol failed to reduce dimerization and as a transmembrane uPAR chimera, which does not partition to lipid rafts, also dimerized efficiently. While uPA bound to uPAR independently of its membrane localization and dimerization status, uPA-induced uPAR cleavage was strongly accelerated in lipid rafts. In contrast to uPA, the binding of Vn occurred preferentially to raft- associated dimeric uPAR and was completely blocked by cholesterol depletion.     

NMR study of manganese(II) binding by a new versatile peroxidase from the white-rot fungus<Emphasis Type="Italic"> Pleurotus eryngii</Emphasis>

Nuclear magnetic resonance spectroscopy has been used to characterize the versatile peroxidase from Pleurotus eryngii, both in the resting state and in the cyanide-inhibited form. The assignment of most of the hyperfine-shifted resonances has been achieved by two-dimensional NMR, allowing the comparison of the present system with other ligninolytic peroxidases. This information has enabled a detailed analysis of the interaction of the enzyme with one of its reducing substrates, Mn(II). Furthermore, comparison with the data collected on a mutant in the putative Mn(II) binding site, and an analysis of the enzyme kinetic properties, shed light on the factors affecting the function of this novel peroxidase.Electronic Supplementary Material Supplementary material is available for this article if you access the article at .Abbreviations ABTS 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate) - CcP cytochrome c peroxidase - CIP Coprinus cinereus peroxidase - HRP horseradish peroxidase - IPTG isopropyl--D-thiogalactopyranoside - LiP lignin peroxidase - MnP manganese peroxidase - RB5 Reactive Black 5 - VA veratryl alcohol (3,4-dimethoxybenzyl alcohol) - VP versatile peroxidase     

A further investigation of the cytochrome<Emphasis Type="Italic"> b</Emphasis><Subscript>5</Subscript>–cytochrome<Emphasis Type="Italic"> c</Emphasis> complex

The interaction of reduced rabbit cytochrome b₅ with reduced yeast iso-1 cytochrome c has been studied through the analysis of ¹H–¹⁵N HSQC spectra, of ¹⁵N longitudinal (R₁) and transverse (R₂) relaxation rates, and of the solvent exchange rates of protein backbone amides. For the first time, the adduct has been investigated also from the cytochrome c side. The analysis of the NMR data was integrated with docking calculations. The result is that cytochrome b₅ has two negative patches capable of interacting with a single positive surface area of cytochrome c. At low protein concentrations and in equimolar mixture, two different 1:1 adducts are formed. At high concentration and/or with excess cytochrome c, a 2:1 adduct is formed. All the species are in fast exchange on the scale of differences in chemical shift. By comparison with literature data, it appears that the structure of one 1:1 adduct changes with the origin or primary sequence of cytochrome b₅.Electronic Supplementary Material Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.Abbreviations HSQC heteronuclear single quantum correlation spectroscopy - MD molecular dynamics     

Dietary arachidonic acid suppresses bone turnover in contrast to low dosage exogenous prostaglandin E(2) that elevates bone formation in the piglet

This study was designed to compare the effects of dietary arachidonic acid (AA) versus prostaglandin E(2) (PGE(2)) on bone cell metabolism and bone mass. Twenty-eight piglets from 7 litters were randomized to 1 of 4 treatments for 15 days: fatty acid supplemented formula (FA: 0.8% of total fatty acids as AA and 0.1% of total fatty acids as DHA)+PGE(2) injections (0.1mg/kg/day), FA+saline injections, standard formula (STD: n-6:n-3 of 8:1) + PGE(2) injections or STD+saline injections. PGE(2) resulted in elevated osteoblast activity as indicated by plasma osteocalcin and also reduced urinary calcium excretion. Dietary FA resulted in reduced bone resorption as indicated by urinary N-telopeptide and reduced bone PGE(2). Both PGE(2) and FA treatments independently lead to elevated femur mineral content, but the combined treatment caused a reduction. Thus the mechanisms by which PGE(2) and FA lead to enhanced bone mass are distinct.     

Properties of complexes of galactomannan of Leucaena leucocephala and Al3+, Cu2+ and Pb2+

The use of biopolymers in many industrial processes is on the increase. The different interactions of biopolymers and electrolytes either in aqueous solutions or in solid state provide different physico-chemical properties and a simple correlation cannot be established. In this study, in order to determine the properties of the complexes of galactomannan of Leucaena leucocephala (gal) with the metal ions Al3+ and Pb2+, toxic elements and Cu2+, essential, the logs of the binding constants of the complexes formed in the aqueous solutions were calculated. Their rheological properties, their thermal behavior, the infrared characteristics and shape and form of the films formed by those complexes in solid state were also determined. The aqueous solutions properties have shown a better complexation between gal and Al3+. The species distribution diagrams have shown an existence of complex species going from acidic to basic pH values. Infrared spectra have proved the complexations as well as the viscosity studies. Thermal stabilities in general were smaller in the complexed species than in the native biopolymers and the films obtained from aqueous solutions showed for Cu2+ the most different morphology compared to the biopolymer itself. A use can be suggested of this biopolymer in environmental remediations besides its already established industrial uses.     

The synaptic vesicle protein CSP alpha prevents presynaptic degeneration

Cysteine string protein alpha (CSPalpha)--an abundant synaptic vesicle protein that contains a DNA-J domain characteristic of Hsp40 chaperones--is thought to regulate Ca2+ channels and/or synaptic vesicle exocytosis. We now show that, in young mice, deletion of CSPalpha does not impair survival and causes no significant changes in presynaptic Ca2+ currents or synaptic vesicle exocytosis as measured in the Calyx of Held synapse. At 2-4 weeks of age, however, CSPalpha-deficient mice develop a progressive, fatal sensorimotor disorder. The neuromuscular junctions and Calyx synapses of CSPalpha-deficient mice exhibit increasing neurodegenerative changes, synaptic transmission becomes severely impaired, and the mutant mice die at approximately 2 months of age. Our data suggest that CSPalpha is not essential for the normal operation of Ca2+ channels or exocytosis but acts as a presynaptic chaperone that maintains continued synaptic function, raising the possibility that enhanced CSPalpha function could attenuate neurodegenerative diseases.