Bacterial reduction of hexavalent molybdenum to molybdenum blue

A bacterium that was able to tolerate and reduce as high as 50 mM of sodium molybdate to molybdenum blue has been isolated from a metal recycling ground. The isolate was tentatively identified as Serratia sp. strain Dr.Y8 based on the carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. ANOVA analysis showed that isolate Dr.Y8 produced significantly higher (P < 0.05) amount of Mo-blue with 3, 5.1 and 11.3 times more molybdenum blue than previously isolated molybdenum reducers such as Serratia marcescens strain Dr.Y6, E. coli K12 and E. cloacae strain 48, respectively. Its molybdate reduction characteristics were studied in this work. Electron donor sources such as sucrose, mannitol, fructose, glucose and starch supported molybdate reduction. The optimum phosphate, pH and temperature that supported molybdate reduction were 5 mM, pH 6.0 and 37°C, respectively. The molybdenum blue produced from cellular reduction exhibited a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. Metal ions such as chromium, silver, copper and mercury resulted in approximately 61, 57, 80, and 69% inhibition of the molybdenum-reducing activity at 1 mM, respectively. The reduction characteristics of strain Dr.Y8 suggest that it would be useful in future molybdenum bioremediation.     

Spatio‐temporal variation of salt marsh seedling establishment in relation to the abiotic and biotic environment

Contrary to our expectations, soil salinity and moisture explained little of the spatial variation in plant establishment in the upper intertidal marsh of three southern California wetlands, but did explain the timing of germination. Seedlings of 27 species were identified in 1996 and 1997. The seedlings were abundant (maximum densities of 2143/m² in 1996 and 1819/m² in 1997) and predominantly annual species. CCAs quantified the spatial variation in seedling density that could be explained by three groups of predictor variables: (1) perennial plant cover, elevation and soil texture (16% of variation), (2) wetland identity (14% of variation) and (3) surface soil salinity and moisture (2% of variation). Increasing the spatial scale of analysis changed the variables that best predicted patterns of species densities. Timing of germination depended on surface soil salinity and, to a lesser extent, soil moisture. Germination occurred after salinity had dropped below a threshold or, in some cases, after moisture had increased above a critical level. Between 32% and 92% of the seedlings were exotic and most of these occurred at lower soil salinity than native species. However, Parapholis incurva and Mesembryanthemum nodiflorum were found in the same environments as the native species. In 1997, the year of a strong El Niño/Southern Oscillation event with high rainfall and sea levels, the elevation distribution of species narrowed and densities of P. incurva and other exotic species decreased but densities of native and rare species did not change. The ‘regeneration niche’ of wetland plant communities includes the effects of multiple abiotic and biotic factors on both the spatial and temporal variations in plant establishment.     

Addition of Cryoprotectant Significantly Alters the Epididymal Sperm Proteome

Although cryopreservation has been developed and optimized over the past decades, it causes various stresses, including cold shock, osmotic stress, and ice crystal formation, thereby reducing fertility. During cryopreservation, addition of cryoprotective agent (CPA) is crucial for protecting spermatozoa from freezing damage. However, the intrinsic toxicity and osmotic stress induced by CPA cause damage to spermatozoa. To identify the effects of CPA addition during cryopreservation, we assessed the motility (%), motion kinematics, capacitation status, and viability of epididymal spermatozoa using computer-assisted sperm analysis and Hoechst 33258/chlortetracycline fluorescence staining. Moreover, the effects of CPA addition were also demonstrated at the proteome level using two-dimensional electrophoresis. Our results demonstrated that CPA addition significantly reduced sperm motility (%), curvilinear velocity, viability (%), and non-capacitated spermatozoa, whereas straightness and acrosome-reacted spermatozoa increased significantly (p < 0.05). Ten proteins were differentially expressed (two decreased and eight increased) (>3 fold, p < 0.05) after CPA, whereas NADH dehydrogenase flavoprotein 2, f-actin-capping protein subunit beta, superoxide dismutase 2, and outer dense fiber protein 2 were associated with several important signaling pathways (p < 0.05). The present study provides a mechanistic basis for specific cryostresses and potential markers of CPA-induced stress. Therefore, these might provide information about the development of safe biomaterials for cryopreservation and basic ground for sperm cryopreservation.     

Postoperative Deep Vein Thrombosis in Sudanese Patients

The incidence of postoperative deep vein thrombosis diagnosed by radioisotope scanning in 100 Sudanese patients aged 40 or over was 12%. This compares with an incidence of nearly 30% in 542 patients reported from British hospitals using the same diagnostic technique. The reason for the difference is obscure and needs further investigation.     

Some components of the air spora in Jamaica and their possible medical application

A knowledge of the pollen and fungal spores which comprise the air spora is useful as a preliminary approach to the problem of respiratory allergy. Therefore, this study of the qualitative and quantitative aspects of the air spora was done. Fungal spores were found to be numerically dominant, comprising 97.73% whilst pollen comprised 0.40% of the total material observed. A small number of types made up the majority of the fungal air spora, namely, Cladosporium, the Sporobolomycetaceae group, Diatrype, Glomerella, hyaline and coloured basidiospores, and septate fusiform spores. Seasonal periodicity studies on twenty-five fungal types showed that a high number of spores were trapped for sixteen during wet months, four during cooler months, and that five showed no seasonal trends. Mean diurnal periodicity studies for the year on the same twenty-five spore types showed that all had a maximum number of spores trapped at some time during the day. Investigation of the effect of rainfall on the numbers of spores released showed that the amount and duration of rainfall, the time of day rain occurs, and the length of the dry period preceding rain were of varying importance to particular spore types.     

Induction of SerpinB2 and Th1/Th2 Modulation by SerpinB2 during Lentiviral Infections In Vivo

SerpinB2, also known as plasminogen activator inhibitor type 2, is a major product of activated monocytes/macrophages and is often strongly induced during infection and inflammation; however, its physiological function remains somewhat elusive. Herein we show that SerpinB2 is induced in peripheral blood mononuclear cells following infection of pigtail macaques with CCR5-utilizing (macrophage-tropic) SIV_mac239, but not the rapidly pathogenic CXCR4-utilizing (T cell-tropic) SHIV_mn229. To investigate the role of SerpinB2 in lentiviral infections, SerpinB2^−/− mice were infected with EcoHIV, a chimeric HIV in which HIV gp120 has been replaced with gp80 from ecotropic murine leukemia virus. EcoHIV infected SerpinB2^−/− mice produced significantly lower anti-gag IgG1 antibody titres than infected SerpinB2^+/+ mice, and showed slightly delayed clearance of EcoHIV. Analyses of published microarray studies showed significantly higher levels of SerpinB2 mRNA in monocytes from HIV-1 infected patients when compared with uninfected controls, as well as a significant negative correlation between SerpinB2 and T-bet mRNA levels in peripheral blood mononuclear cells. These data illustrate that SerpinB2 can be induced by lentiviral infection in vivo and support the emerging notion that a physiological role of SerpinB2 is modulation of Th1/Th2 responses.     

[14C]-Glucose Metabolism during Shoot Bud Development in Cultured Cotyledon Explants of Pinus radiata

Excised cotyledons of Pinus radiata D. Don cultured under shoot-forming(plus benzyladenine) and non shoot-forming (minus benzyladenine)conditions for 10 and 21 days were fed U-[¹⁴C]-glucose for 3h in the light followed by a 3 h chase period. The labellingof individual metabolites as well as ¹⁴C incorporation intoprotein was assessed. It was found that the general metabolicpatterns were qualitatively the same in shoot-forming and nonshoot-forming conditions, however, metabolism leading to respirationas well as to the synthesis of some amino acids and proteinsynthesis was enhanced in the shoot-forming cultures. (Received February 16, 1987; Accepted July 8, 1987)     

Mammalian sulfoconjugate metabolism

Sulfoconjugates occur ubiquitously as sulfopolysaccharides, sulfolipids and sulfoproteins. A variety of sulfotransferases catalyze the sulfation process with 3’-phosphoadenosine 5’-phosphosulfate as the sulfate donor. Sulfatases that catalyze the desulfation of different sulfoconjugates are known to be deficient in a number of genetic storage disorders.