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排序方式: 共有611条查询结果,搜索用时 31 毫秒
1.
Polydeoxyribonucleotides and nitric oxide release from guinea-pig hearts during ischaemia and reperfusion. 总被引:1,自引:1,他引:0 下载免费PDF全文
E. Masini M. Lupini L. Mugnai S. Raspanti P. F. Mannaioni 《British journal of pharmacology》1995,115(4):629-635
1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed. 相似文献
2.
This study investigated the extent of impairment in functional parameters of liver mitochondria from rats treated for 60 days with hexachlorobenzene (HCB). A constant amount of mitochondrial uncoupling was found throughout the treatment period. At the same time a nearly constant amount of pentachlorophenol was detected in these mitochondria. In contrast, the level of mitochondrial porphyrins increased progressively. There was good correlation between the concentration of mitochondrial pentachlorophenol and the degree of uncoupling of oxidative phosphorylation. 相似文献
3.
4.
Inducible nitric oxide synthase expression in human colorectal cancer: correlation with tumor angiogenesis 总被引:15,自引:0,他引:15 下载免费PDF全文
Cianchi F Cortesini C Fantappiè O Messerini L Schiavone N Vannacci A Nistri S Sardi I Baroni G Marzocca C Perna F Mazzanti R Bechi P Masini E 《The American journal of pathology》2003,162(3):793-801
To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (r(s) = 0.31, P = 0.02 and r(s) = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis. 相似文献
5.
Predator odors have been shown to elicit stress responses in rats. The present studies assessed the use of domestic ferret odor as a processive stress model. Plasma corticosterone and adrenocorticotropin hormone levels were higher after 30 min of exposure to ferret odor (fur/skin) but not control odors, ferret feces, urine, or anal gland secretions. Behavioral differences were also found between ferret and the control odors as tested in a defensive withdrawal paradigm. In addition, c-fos messenger RNA expression in several brain areas previously associated with processive stress was significantly higher in ferret odor-exposed rat brains than in control odor-exposed brains. These results suggest that ferret odor produces a reliable unconditioned stress response and may be useful as a processive stress model. 相似文献
6.
Down-regulation of nitric oxide synthase-2 and cyclooxygenase-2 pathways by p53 in squamous cell carcinoma 总被引:7,自引:0,他引:7 下载免费PDF全文
Gallo O Schiavone N Papucci L Sardi I Magnelli L Franchi A Masini E Capaccioli S 《The American journal of pathology》2003,163(2):723-732
The goal of this study was to analyze the correlation between inducible nitric oxide synthase (iNOS) and COX-2 activities and p53 gene status in head and neck squamous cell carcinomas (HNSCCs) in vivo and in vitro. In a series of 43 HNSCCs we observed an up-regulation of both iNOS and COX-2 pathways in tumor tissues and both activities were correlated each other (rs = 0.612 and P = 0.0002). We also found that p53-mutated HNSCCs (25 cases, 58.1%) showed higher levels of iNOS activity and cGMP in comparison with wild-type p53 tumors (18 cases, 41.9%) (P = 0.0005 and P = 0.01), as well as higher iNOS immunohistochemical expression (P = 0.03). Analogously, higher PgE2 levels were documented in p53-mutated HNSCCs when compared with wild-type p53 tumors (P = 0.015) and COX-2 protein expression was higher in p53-mutated HNSCCs (P = 0.007). A431 cancer cells expressing a p53 temperature-sensitive mutant showed an approximately 1.9- and 2.6-fold decrease in spontaneous NO(2-)/NO(3-) and PgE2 synthesis at permissive temperature, respectively, when compared with the same cells at nonpermissive temperature (P 相似文献
7.
G C Zucchelli A Clerico A Pilo S Masini F Zoppi M L Bovati P Gazzetti L Giovannini A A Bertelli 《International journal of tissue reactions》1989,11(6):315-320
Results obtained measuring blood Cyclosporine A (CsA) concentrations in transplanted patients (124 samples of cardiac, 20 samples of liver, and 10 samples of kidney transplanted patients) by the use of two monoclonal radioimmunoassay (RIA) methods have been compared with those found using the HPLC technique (considered as the reference method) and two polyclonal RIAs. In addition, results on quality control samples collected in a multicentre collaborative study for CsA assay from the users of the same monoclonal and polyclonal RIAs were analysed to evaluate the performance of the methods under study. Polyclonal RIAs, which measure both the parent molecule and its metabolites, produced results 1.5-3 times higher than HPLC or monoclonal RIAs. On the contrary the two RIAs, which use monoclonal antibodies specific for CsA, show a better correlation with HPLC; these RIAs, which measure the intact drug molecule only, are recommended when the monitoring of the native molecule of CsA is requested. As far as the reproducibility is concerned, the four RIAs (both polyclonal and monoclonal) exhibit an unsatisfactory degree of between-assay and between-lab precision, since the coefficients of variation (CVs) ranged from 19.4% to 23.1%. 相似文献
8.
E Masini R Fantozzi A Conti P Blandina S Brunelleschi P F Mannaioni 《International archives of allergy and applied immunology》1985,77(1-2):184-185
Mast cell heterogeneity in response to acetylcholine has been evidentiated by the virtual lack of sensitivity or by the full reaction to nanomolar concentrations of acetylcholine, observed in samples of serosal mast cells isolated from the same animal species. The incubation with IgE of isolated rat mast cells renders the originally heterogeneous response homogeneous, the release of histamine evoked by acetylcholine being proportional to the IgE concentration. The histamine release induced by acetylcholine is due to the activation of muscarinic receptors, since it is blocked by atropine, not reproduced by acetylthiocholine and potentiated by exposure of the cells to the specific antigen. 相似文献
9.
Human herpesvirus 8 seroprevalence and evaluation of nonsexual transmission routes by detection of DNA in clinical specimens from human immunodeficiency virus-seronegative patients from central and southern Italy, with and without Kaposi's sarcoma 下载免费PDF全文
Cattani P Capuano M Cerimele F La Parola IL Santangelo R Masini C Cerimele D Fadda G 《Journal of clinical microbiology》1999,37(4):1150-1153
In order to investigate the seroprevalence of human herpesvirus 8 (HHV-8) infection in central and southern Italy, sera from human immunodeficiency virus (HIV)-seronegative subjects, with and without Kaposi's sarcoma (KS), were analyzed by immunofluorescence assay, using BC-3, a cell line latently infected with HHV-8. High titers of antibody against HHV-8 lytic and latent antigens were detected in all 50 KS patients studied, while in 50 HIV-seronegative subjects without KS, 32 (64%) were found positive for HHV-8 antibodies. Titers in the sera of these patients were lower than those for KS patients. This data suggests that HHV-8 infection is not restricted to KS patients and that the prevalence of HHV-8 infection in the general population may be correlated with differing rates of prevalence of KS in different parts of the world. In view of these findings, possible nonsexual transmission routes were evaluated. Nested PCR was used to test for the presence of HHV-8 DNA in saliva, urine, and tonsillar swabs from KS and non-KS patients. In KS patients, 14 out of 32 tonsillar swabs (43.7%), 11 out of 24 saliva samples (45.8%), and just 2 out of 24 urine samples (8.3%) tested positive for HHV-8 DNA. In the control group, on the contrary, none of the 20 saliva and 20 urine specimens was positive for HHV-8 DNA; only 1 out of 22 tonsillar swabs gave a positive result. This data supports the hypothesis that HHV-8 infects the general population in a latent form. The reactivation of viral infection may result in salivary shedding of HHV-8, contributing to viral spread by nonsexual transmission routes. 相似文献
10.
E. Giannella E. Masini B. Palmerani A. Pistelli P. F. Mannaioni 《Inflammation research》1988,23(3-4):185-187
Calcium antagonists have been reported to exert protective effects in hypersensitivity reactions in man and animals. However, their effect on anaphylactic histamine release is highly variable and controversial. In the present paper we evaluate the effect of calcium entry blockers and BAY K 8644 on the response to specific antigen in isolated hearts taken from actively sensitized guinea-pigs and from isolated rat and guinea-pig mast cells, actively or passively sensitized. Verapamil, diltiazem, nifedipine and prenylamine dose-dependently decreased anaphylactic histamine release in isolated actively sensitized guinea-pig mast cells. BAY K 8644 was found to be ineffective. In isolated, passively sensitized rat mast cells, verapamil showed a highly signficant inhibitory effect, while prenylamine (10–4
M) was able to evoke a histamine releasing effect. In cardiac anaphylaxis verapamil, diltiazem, prenylamine, but not nifedipine, were active in reducing the release of histamine without modifying the antigen-induced arrhythmias and positive chronotropic and inotropic effects. 相似文献