Characteristics of arylsulfatase in Russian sturgeon (Acipenser gueldenstaedti) semen

Spermatozoa of sturgeons (Acipenseriformes), unlike teleosts, possess an acrosome. This paper provides data concerning biochemical characteristics of arylsulfatase (AS), an acrosomal enzyme, found in Russian sturgeon spermatozoa and seminal plasma. The enzymes were purified by a four-step procedure, using n-butanol extraction, ion-exchange chromatography repeated twice and gel filtration. High purity of our enzymes was confirmed by silver staining electrophoresis and an immunological experiment. Kinetic parameters indicated that the purified enzymes belong to arylsulfatase type A. Similarity of the seminal plasma arylsulfatase to the spermatozoan enzyme showed us that arylsulfatase from seminal plasma might originate from damaged spermatozoa. The possible physiological consequences of the presence of arylsulfatase in Russian sturgeon semen are discussed.     

Adaptation of sympatric Achromatium spp. to different redox conditions as a mechanism for coexistence of functionally similar sulphur bacteria

Changes in the abundance of sympatric Achromatium spp. in response to the artificial manipulation of redox conditions in sediment microcosms was determined by fluorescence in situ hybridization (FISH). Adaptation to different redox conditions was shown to be one mechanism that supported the coexistence of functionally similar Achromatium spp. In sediment microcosms, in which the overlying water was oxygenated, Achromatium community size and composition remained unchanged over time. However, imposition of anoxic conditions induced changes in community structure. Anoxia caused a reduction in the relative abundance of Achromatium sp. RY8 (72 +/- 4% to 49 +/- 2%) and an increase in Achromatium sp. RY5 (19 +/- 5% to 32 +/- 3%) and a newly identified Achromatium sp., RYKS (14 +/- 4% to 27 +/- 2%). In anoxic microcosms supplemented with a single addition of nitrate at different initial concentrations the relative decline in Achromatium sp. RY8 was dependent on the initial nitrate concentration. In these experiments nitrate was rapidly removed. In contrast, when high levels of nitrate were maintained by periodic replacement of the overlying water with nitrate supplemented anoxic water, the composition of the Achromatium community remained stable over time. This suggested that all of the coexisting Achromatium spp. are obligate or facultative anaerobes, but, Achromatium sp. RY8 was more sensitive to sediment redox conditions than the other Achromatium species. Given the heterogeneous nature of sedimentary environments, redox-related niche differentiation may promote coexistence of sympatric Achromatium spp.     

Integracides: tetracyclic triterpenoid inhibitors of HIV-1 integrase produced by Fusarium sp

HIV-1 integrase is a critical enzyme in the replication of HIV-1. It is absent in the host cells and therefore is a good target for treatment of HIV-1 infections. Integracides are members of the tetracyclic triterpenoids family that were isolated from the fermentation broth of a Fusarium sp. Integracide A, a sulfated ester, exhibited significant inhibitory activity against strand transfer reaction of HIV-1 integrase. The discovery, structure elucidation including single crystal X-ray structure and HIV-1 inhibitory activity of these compounds are described.     

Administration of a nitric oxide synthase inhibitor counteracts prostaglandin F2-induced luteolysis in cattle

The objective of this study was to determine whether nitric oxide (NO) is produced locally in the bovine corpus luteum (CL) and whether NO mediates prostaglandin F2alpha (PGF2alpha)-induced regression of the bovine CL in vivo. The local production of NO was determined in early I, early II, mid, late, and regressed stages of CL by determining NADPH-d activity and the presence of inducible and endothelial NO synthase immunolabeling. To determine whether inhibition of NO production counteracts the PGF2alpha-induced regression of the CL, saline (10 ml/h; n = 10) or a nonselective NOS inhibitor (Nomega-nitro-l-arginine methyl ester dihydrochloride [L-NAME]; 400 mg/h; n = 9) was infused for 2 h on Day 15 of the estrous cycle into the aorta abdominalis of Holstein/Polish Black and White heifers. After 30 min of infusion, saline or cloprostenol, an analogue of PGF2alpha (aPGF2alpha; 100 microg) was injected into the aorta abdominalis of animals infused with saline or L-NAME. NADPH-diaphorase activity was present in bovine CL, with the highest activity at mid and late luteal stages (P < 0.05). Inducible and endothelial NO synthases were observed with the strongest immunolabeling in the late CL (P < 0.05). Injection of aPGF2alpha increased nitrite/nitrate concentrations (P < 0.01) and inhibited P4 secretion (P < 0.05) in heifers that were infused with saline. Infusion of L-NAME stimulated P4 secretion (P < 0.05) and concomitantly inhibited plasma concentrations of nitrite/nitrate (P < 0.05). Concentrations of P4 in heifers infused with L-NAME and injected with aPGF2alpha were higher (P < 0.05) than in animals injected only with aPGF2alpha. The PGF2alpha analogue shortened the cycle length compared with that of saline (17.5 +/- 0.22 days vs. 21.5 +/- 0.65 days P < 0.05). L-NAME blocked the luteolytic action of the aPGF2alpha (22.6 +/- 1.07 days vs. 17.5 +/- 0.22 days, P < 0.05). These results suggest that NO is produced in the bovine CL. NO inhibits luteal steroidogenesis and it may be one of the components of an autocrine/paracrine luteolytic cascade induced by PGF2alpha.     

X-ray diffraction and high-resolution NMR spectroscopy of methyl 3-azido-2,3-dideoxy-alpha-D-lyxo-hexopyranoside

The single-crystal X-ray diffraction and high-resolution 1H and 13C NMR spectral data for the title compound are reported. The influence of the ring oxygen atom on the J(1,2e) and J(4,5) coupling constants for 2-deoxy-D-lyxo- and -D-xylo-hexopyranosides is discussed.     

The use of tri-O-acetyl-D-glucal and -D-galactal in the synthesis of 3-acetamido-2,3-dideoxyhexopyranoses and -hexopyranosides

Addition of hydrazoic acid to alpha,beta-unsaturated aldehydes derived from tri-O-acetyl-D-glucal and -D-galactal gave 3-azido-2,3-dideoxyhexopyranoses. These were converted into 1,4,6-tri-O-acetyl-3-azido-2,3-dideoxyhexopyranoses as well as methyl and ethyl glycosides. Hydrogenation of the proamine group in 3-azido-2,3-dideoxy derivatives provided different 3-amino and 3-acetamido sugars. The configuration and conformation of all products were established on the basis of the 1H and 13 C NMR, IR and polarimetric data.     

Comparison of multiplex PCR,and an immunochromatographic method sensitivity for the detection of Escherichia coli O157:H7 in minced beef

In this study, the sensitivities of multiplex PCR and an immuno-chromatographic methods to detect Escherichia coli O157:H7 in minced beef were compared. The detection of Escherichia coli O157:H7 in minced beef inoculated with 1-100 cells of this bacterium was possible after enrichment of culture and subsequent analysis by either of the two methods. Enrichment conditions were eight hours of incubation at 37 degrees C or 42 degrees C in a non-selective medium (Buffered Peptone Water). Multiplex PCR analysis was performed using three primer sets with analysis by gel electrophoresis. The Quix immuno-chromatographic assay which is a new kit being marketed by New Horizons Diagnostics, Columbia, MD, was used for immunological analysis of the enriched broths.The sensitivity of both tests was similar. The results depended on the concentration of the specific bacterium in the culture since the influence of the proportion of other bacteria to the E. coli O157:H7 was not observed. The data suggests that either method or used together, when coupled with an enrichment technique, could provide a rapid mean to detect the presence of this pathogen in minced meat samples.     

Yeast-like fungi as etiologic agents of blood infections in patients hospitalized in 1998-1999

The aim of the study was the analysis of frequency of yeast-like fungi as etiological agents of fungemias in patients hospitalized in operative and conservative wards of Medical Academy Central Clinical Hospital in Warsaw in 1998-1999. Peripheral blood samples and collected from vascular catheters were incubated in BacT/Alert system(Organon Teknika, USA). Positive blood samples were inoculated on Sabouraud medium with chloramphenicol (bioMerieux, France) (the time of cultivation from 48 h to 7 days at 30 C) and on chromogenic medium BBL CHROMagar Candida (Becton Dickinson, USA). Fungal strains were identified by standard mycological procedures using ID 32 C strips (ATB system, bioMerieux, France) and tests of Sanofi Diagnostics Pasteur (France). The total number of positive blood cultures was 1724. Fifty eight fungal strains were isolated from blood samples (3.36%). Strains belonged to 4 genera: Candida (55), Trichosporon (1), Saccharomyces (1) and Pichia (1). Thirty eight fungal strains were isolated from peripheral blood samples. Forty seven fungal strains were cultured from patients hospitalized in operative wards. Among fungi isolated from peripheral blood samples C. albicans (10), C. glabrata (9) and C. parapsilosis (5) strains dominated. From blood samples collected from vascular catheters most often C. albicans (7), C. glabrata (4) and C. parapsilosis (3) were isolated.