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51.
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. 相似文献
52.
Swoboda-Kopeć E Sawicka-Grzelak A Rokosz A Wróblewska M Sulik-Tyszka B Stelmach E łuczak M 《Medycyna do?wiadczalna i mikrobiologia》2002,54(2):167-171
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. 相似文献
53.
Weber-Dabrowska B Zimecki M Mulczyk M Górski A 《FEMS immunology and medical microbiology》2002,34(2):135-138
The aim of this investigation was to establish the impact of phage therapy on the turnover and function of circulating neutrophils in 37 patients with suppurative bacterial infections. We determined the levels of circulating neutrophils and their precursors before therapy, after 3 weeks of therapy, and at a distant time interval (3 months) following the beginning of therapy. In addition, we measured the ability of neutrophils to phagocytize Staphylococcus aureus in vitro. Eight healthy blood donors served as a control group. The results showed that, among the studied parameters, the significant changes involved neutrophil precursor count and the ability of neutrophils to phagocytize bacteria. The percentage of neutrophils in patients before therapy was lower than in healthy donors (mean 58.0, versus 61.4). This value dropped further in patients after 3 months of following the therapy (mean 55.6). The content of neutrophil precursors, on the other hand, was lower in healthy donors than in patients before therapy (mean 2.5, versus 3.8). After 3 weeks of the therapy and after 3 months, the levels of neutrophil precursors were significantly higher (mean 4.8 and 4.9, respectively) than in control donors. The phagocytic index was lower in patients before therapy than in control donors (mean 66.3, versus 70.1) and decreased further after 3 weeks of therapy (mean 59.0) and after 3 months (mean 59.6). The results of this investigation indicate that successful phage therapy accelerates the turnover of neutrophils, accompanied by a decrease in their ability to phagocytize bacteria. 相似文献
54.
The involvement of oxytocin (OT) in the regulation of glucocorticoid secretion during stress reaction, parturition, and suckling has been documented in various species. In this study four in vivo experiments were conducted on gilts (1) to demonstrate the influence of mating stimuli on plasma cortisol concentration, (2) to test the effect of OT alone and (3) OT combined with OT-antagonist on cortisol secretion and (4) to clarify the role of progesterone and estradiol in cortisol response to exogenous OT. In experiment 1, plasma cortisol concentration in gilts (n=4) increased (p<0.05) from 16.1 +/- 5.3 ng ml(-)1 (control period: 30 min before mating) to 42.8 +/- 11.6 ng ml(-1) and 46.6 +/- 9.6 ng ml(-1) at the time of leaving the pen and during the first visual and olfactory contact with the boar, respectively. During coitus the elevation was maintained (48.8 +/- 9.8 ng ml(-1); p<0.05 vs. control). The plasma cortisol concentration returned to pre-mating levels within 30 min after mating. In experiment 2, gilts (n=7) were treated, according to Latin square design, with saline (2 ml; i.v.) and OT (10, 20, and 30 IU; i.v.). The magnitude of cortisol response (area under cortisol curve) was higher (p<0.01) only after treatments with 20 and 30 IU OT vs. control period (30 min before OT). Gilts (n=3) of experiment 3 were infused with OT-antagonist (Atosiban; 25 mg per gilt per 2 hours; i.v.) and then were injected with OT (20 IU; i.v.) 60 min after the beginning of Atosiban administration. Blockage of OT receptors by Atosiban reversed the stimulatory effect of OT on cortisol secretion. In experiment 4, ovariectomized gilts (n=25) primed (i.m.) with corn oil (n=7), progesterone (P4; n=7), estradiol benzoate (EB; n=4) or EB+P4 (n=7) were treated with OT (20 IU; i.v.). Plasma cortisol concentrations were increased following OT administration in all gilts of experiment 4. The highest cortisol response to OT was noted in gilts primed with EB+P4 (p<0.01 vs. other groups). In conclusion: (1) leaving the pens, visual and olfactory contact with the boar as well as coitus, increased plasma cortisol concentrations in gilts to similar levels; (2) exogenous OT (20 and 30 IU per gilt) increased cortisol plasma concentration, (3) this effect was abolished by OT-antagonist and (4) E2+P4 elevated cortisol response to OT. Oxytocin may be included to secretagogues of the hypothalamus-pituitary-adrenocortical axis in pigs. 相似文献
55.
56.
57.
Bovine erythrocytes treated with peroxynitrite (ONOO(-)), a cytotoxic species formed in vivo via the reaction of nitric oxide (NO(.)) and the superoxide anion (O2(-.)), show an increased rate of hemolysis on sudden osmotic stress. The increase in the rate was peroxynitrite concentration dependent. In the presence of some antioxidants (uric acid, ascorbic acid, glutathione, melatonin and albumin), this effect was significantly lower, with ascorbic acid as the most efficient antioxidant. 相似文献
58.
The iron-sulfur protein subunit, known as the Rieske protein, is one of the central components of the cytochrome b(6)f complex residing in chloroplast and cyanobacterial thylakoid membranes. We have constructed plasmids for overexpression in Escherichia coli of full-length and truncated Rieske (PetC) proteins from the Spinacia oleracea fused to MalE. Overexpressed fusion proteins were predominantly found (from 55 to 70%) in cytoplasm in a soluble form. The single affinity chromatography step (amylose resine) was used to purify about 15mg of protein from 1 liter of E. coli culture. The isolated proteins were electrophoretically pure and could be used for further experiments. The NifS-like protein IscS from the cyanobacterium Synechocystis PCC 6803 mediates the incorporation of 2Fe-2S clusters into apoferredoxin and cyanobacterial Rieske apoprotein in vitro. Here, we used the recombinant IscS protein for the enzymatic reconstitution of the iron-sulfur cluster into full-length Rieske fusion and truncated Rieske fused proteins. Characterization by EPR spectroscopy of the reconstituted proteins demonstrated the presence of a 2Fe-2S cluster in both full-length and truncated Rieske fusion proteins. 相似文献
59.
Wielgus-Kutrowska B Frank J Holý A Koellner G Bzowska A 《Nucleosides, nucleotides & nucleic acids》2003,22(5-8):1695-1698
Binding enthalpies, dissociation constants and stoichiometry of binding for interaction of trimeric calf spleen and Cellulomonas sp. purine nucleoside phosphorylases with their ground state analogues (substrates and inhibitors) were studied by calorimetric and spectrofluorimetric methods. Data for all ligands, with possible exception of hypoxanthine, are consistent with three identical non-interacting binding sites. 相似文献
60.
P2Y(1) receptor activation inhibits NMDA receptor-channels in layer V pyramidal neurons of the rat prefrontal and parietal cortex 总被引:3,自引:0,他引:3
Luthardt J Borvendeg SJ Sperlagh B Poelchen W Wirkner K Illes P 《Neurochemistry international》2003,42(2):161-172
In the 1st part of this study, monosynaptic excitatory postsynaptic potentials (EPSPs) in layer V of the rat prefrontal cortex (PFC) were evoked by electrical stimulation of layer I. Recordings with intracellular sharp, microelectrodes showed a concentration-dependent inhibition of the EPSP by adenosine 5'-O-(2-thiodiphosphate) (ADP-beta-S). Pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), when given alone depressed the EPSP and in addition antagonized the effect of ADP-beta-S. Exclusion of the N-methyl-D-aspartate (NMDA) component of the EPSP by D(.)-amino-5-phosphonopentanoic acid (AP-5) abolished the ADP-beta-S-induced depression. The pressure-application of both NMDA and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) caused reproducible depolarizations. ADP-beta-S inhibited the effect of NMDA, but did not alter that of AMPA. PPADS was also under these conditions antagonistic with ADP-beta-S. In the 2nd part of the study, NMDA-induced currents were measured by whole-cell patch-clamp pipettes. ADP-beta-S caused a concentration-dependent inhibition of the responses to NMDA. PPADS alone did not alter the NMDA-currents but again antagonized the action of ADP-beta-S; 2'-deoxy-N(6)-methyladenosine-3',5'-diphosphate (MRS 2179) also abolished the NMDA effect. The ADP-beta-S-induced inhibition persisted in the presence of tetrodotoxin (TTX) or guanosine 5'-O-(3-thiodiphosphate) (GDP-beta-S) applied to the external medium and the pipette solution, respectively. The 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) moderately decreased the ADP-beta-S effect. The inhibitory function of ADP-beta-S on EPSPs and the interaction with PPADS was observed also in layer V pyramidal neurons of the parietal somatosensory cortex. In conclusion, metabotropic P2Y(1) receptors appear to exert a new modulatory influence on fast excitatory amino acid transmission in the cerebral cortex. 相似文献