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21.
Bacterial cultures were selected from the native flora of liquid manure in order to metabolize liquid manure substances. The mixed culture used in the growth experiments is characterized by low growth rates when maximum degradation of acetate occurs. The biomass concentration reached 2.2 g/l.  相似文献   
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Polyclonal rabbit anticotinine antiserum, which can be used for biomonitoring nicotine uptake by the determination of cotinine in body fluids, was checked by a competitive ELISA for its cross-reactivity with nine nicotine metabolites. The highest percentage of relative crossreactivity (about 30%) was observed with trans-3-hydroxycotinine, a metabolite which is known to be excreted in 3-fold higher amounts than cotinine in the urine of human smokers. Therefore, it is possible that cotinine determinations performed by immunochemical methods — especially in urine — may yield overestimated cotinine concentrations.  相似文献   
24.
The stability of the neuroleptic peptide des-enkephalin--endorphin (DEE; Org 5878) in the rectal lumen and the rectal bioavailability of DEE were investigated in conscious rats. Furthermore, the influence of peptidase inhibition, peptidase saturation, and absorption enhancement on DEE bio-availability were evaluated. Na2EDTA (0.25%, w/v) prolonged the degradation half-life of DEE in the ligated colon from 33 ± 7 to 93 ± 45 min. Without adjuvant, tritium-labeled DEE was absorbed from the rat rectum to a very low extent (0–4%). After administration of an excess of unlabeled DEE or with Na2EDTA, comparable results were obtained. The medium-chain glyceride preparation MGK markedly enhanced the rectal DEE bioavailability, up to 8–20%, which was further increased to 10–44% by coadministration of Na2EDTA. No substantial influence of varying the rectal delivery rate was observed. The results suggest that absorption enhancement and enzyme inhibition both are essential for effective increase of rectal peptide bioavailability.  相似文献   
25.
HIV-1-infected patients exhibit severe damages of the aortic endothelium, develop angioproliferative lesions such as Kaposi's sarcoma (KS), and have an increased risk of cardiovascular diseases and atherosclerosis. An increased adhesion of leukocytes to the endothelium is a common pathogenic parameter of AIDS-associated vascular diseases. Here we show that the HIV-1 Tat protein, a regulatory protein of HIV-1 released by infected cells, and TNF-alpha, a cytokine increased in sera and tissues of HIV-1-infected patients, activate synergistically the adhesion of leukocytes to endothelial cells both in vitro and in vivo. This effect is selectively mediated by HIV-1 Tat, since HIV-1 Nef, another HIV-1 regulatory protein, and the HIV-1 envelope protein gp41, had no effect. In vitro adhesion assays with PBMC and quantitative cell type analysis of adherent cells by FACS demonstrated that HIV-1 Tat selectively activates the adhesion of T-cells and monocytes but not of B-cells. Intravital microscopic studies in mice confirmed the synergistic activity of HIV-1 Tat and TNF-alpha on leukocyte adhesion to the endothelium in vivo. These data indicate that HIV-1 Tat in cooperation with TNF-alpha may contribute to the vascular damage and cardiovascular diseases observed in AIDS patients but also to the prominent extravasation of T-cells and monocytes which is a key process in the formation and progression of KS lesions.  相似文献   
26.
Several lines of evidence suggest that the auditory evoked potential (AEP) augmenting/reducing slope may serve as a biological marker of central serotonergic activity. According to Hegerl and Juckel (Biol. Psychiatry, 33, 1993, 173), reduced serotonergic activity is hypothesized to increase the slope of the AEP amplitude stimulus intensity function (ASF-slope). Hints for this hypothesis were investigated by employing the acute tryptophan depletion paradigm in 18 healthy females. A within-subject, placebo controlled double-blind cross over design was used for that purpose. Subjects ingested both a 50 g amino-acid drink with (placebo condition) and without tryptophan (depletion condition). With respect to the N1/P2-slope, test-retest reliability of a 1 week interval ranged between r=0.56 and 0.58 for the pre-ingestion baseline recording sessions. Affect was not altered by tryptophan depletion and not related to the ASF-slope. The comparison between placebo and depletion conditions did not reveal significant alterations of the ASF-slope, neither after 5 nor 6 h post-ingestion. Thus, the results do not support the assumption of the ASF-slope reflecting central serotonergic function.  相似文献   
27.
Irpex lacteus, a wood-decaying basidiomycete, was isolated from a pulmonary abscess of an immunosuppressed child. This medical strain was compared morphologically and by sequencing of the ribosomal intergenic spacers with specimens from both culture collections and herbarium desiccated material. The patient was treated successfully with amphotericin B.  相似文献   
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Resting CD4(+) T cells in the lymphoid tissue (LT) are essential producers of virions at the beginning of HIV infection in vivo. We previously developed a model that allowed in vitro infection of non-prestimulated T lymphocytes in the presence of autologous B lymphocytes and complement. In this study, we try to clarify the mechanism(s) responsible for virus transmission in unstimulated autologous B cell/T cell co-cultures. Ex vivo analyses of patient plasma samples revealed that HIV was opsonized. Flow cytometry showed that opsonized virus preferentially bound to complement receptor (CR)-2 on B lymphocytes in primary B cell/T cell co-cultures. As indicated by cytokine measurements and transwell experiments, soluble factors seemed to play a minor role in enabling infection. Rather, direct interaction between B and T lymphocytes and direct binding of opsonized virus to CR2 on B cells turned out to be essential for productive infection. Antibodies blocking cell-cell adhesion inhibited p24 antigen production. An anti-CR2 antibody blocking C3d-CR2 binding also significantly reduced viral replication. Since the infection of unstimulated T cells by opsonized primary HIV isolates in the presence of B cells was highly efficient independent of the tropism of the virus, this mechanism may be critical in the pathogenesis of HIV.  相似文献   
30.
The high incidence of HER2 overexpression on the cell surface of breast cancer cells and the recognized prognostic and potentially predictive value of HER2 render this cell surface receptor a novel and important therapeutic target. Although immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridization (FISH; PathVysion and INFORM)-both approved by the Food and Drug Administration-have emerged as the most viable assays for evaluation of HER2 status in routine clinical practice, there is still no consensus on which is the best method for assessing HER2 status. Therefore, our specific objective was to establish a chromogenic in situ hybridization (CISH) assay for the detection of HER2 amplification on a cohort of 173 archival invasive breast carcinomas. Results were compared with HercepTest, which is the most frequently used method for detecting HER2 alteration. Additionally, HER2 gene copy number was investigated using differential PCR (dPCR) as a testing system. HER2 overexpression was found by IHC in 24.3%; HER2 amplification was found by CISH in 19.1% and by dPCR in 9.2% of the tumors. The overall concordance rate was 95.9% between CISH and IHC and 85.0% between dPCR and IHC. Kappa statistics revealed an excellent agreement between IHC and CISH (kappa = 0.878), but only a moderate agreement was found between IHC and dPCR (kappa = 0.482). Discrepant cases between CISH and HercepTest and all IHC-positive cases (+2 and +3), a total of 42 cases, were analyzed with the FISH PathVysion (Vysis) assay. Among 25 HercepTest-positive cases (score +3), 2 showed no gene amplification by FISH or CISH. Four of 13 tumors with weak HER2 overexpression (score +2) were negative with both FISH and CISH. Concordance between CISH and FISH was 100% for the 38 cases analyzed. The current study showed that CISH represents a practical and simple assay for evaluating HER2 gene amplification in archival material, offering a promising alternative to IHC or FISH for the routine diagnostic setting.  相似文献   
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