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991.
In order to clarify the influence of inflammatory mediators of the arachidonic acid cascade in the mechanism of nasal polyp growth, peptido-leukotriene (pLT), prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) synthesis was investigated. In addition to several stimuli, functionally intact human biopsy specimens of polypous and normal tissue were incubated. Especially remarkable was the significantly increased release of pLT by polypous tissue upon arachidonic acid stimulation, in contrast to only slightly elevated PGE2 release compared to normal tissue. Basic release of pLT and PGE2 was similar for polypous and normal tissue. Examining TXB2 release, no significant difference was observed with regard to the origin of tissues. These data support an altered pattern of the lipoxygenase and cyclo-oxygenase pathways when tissue becomes irritated and suggest their involvement in the aetiopathogenesis of nasal polyps.  相似文献   
992.
Concern has been expressed about the cost-effectiveness of the Coronary Care Unit (CCU) and solution options offered on account of the large number of patients admitted to the CCU who turn out not to have acute myocardial infarction. In a prospective study over four years, we studied a group of patients admitted to the CCU with suspected myocardial infarction but who did not have diagnostic ECG and/or enzyme changes for the causes of their chest pain. We compared the clinical profile of these patients (Group A) with that of a random sample of patients with confirmed myocardial infarction (Group B). Gastrointestinal disorders, musculoskeletal chest pain, panic and anxiety disorders were the major causes of chest pain in Group A patients. A normal ECG and a normal creatine phosphokinase (CPK) within the first 24 hours, a normal initial random blood sugar, a younger age and absence of coronary risk factors effectively separated Group A patients as low risk from Group B patients as high risk for acute myocardial infarction. These simple parameters will assist physicians providing CCU care in most hospitals in early decision making and in the judicious use of the CCU.  相似文献   
993.
Prostate-specific antigen (PSA) is a widely used marker for screening and monitoring prostate cancer. We identified and characterized the epitopes of two anti-PSA monoclonal antibodies (mAbs) designated B80 and B87. The epitopes were initially mapped as nonoverlapping by developing a sandwich immunoassay to measure PSA with the two anti-PSA mAbs. The two antibodies do not cross-react with homologous pancreatic kallikrein, but recognize epitopes unique to PSA. B80 and B87 can recognize both free and complexed PSA and hence measure total PSA. Epitope scanning and bacteriophage peptide library affinity selection procedures were used to identify and locate an epitope on PSA. A possible epitope for B80 was identified as being located on or near PSA amino acid residues 50-58 (-GRH-SLFHP-). The epitope for B87 was likely on an exposed nonlinear conformational determinant, unique to PSA, and not masked by the binding of B80 or alpha 1-antichymotrypsin.  相似文献   
994.
Recent studies suggest a role for p53 in prostate cancer progression. Although p53 mutations in primary prostate cancer tissues are relatively infrequent, they occur at significant levels in metastatic disease. Here we describe a novel approach to the molecular analysis of p53 in paired specimens of primary and metastatic prostate cancer that results in quantitative estimates of the extent of clonal expansion. In 20 pairs with 1 or both specimens p53 immunopositive and in 6 pairs with both specimens immunonegative, the frequency of mutations was estimated by microdissection of the cancer from fixed and sectioned tissues, isolation of the DNA followed by PCR amplification of p53 genomic fragments, and cloning of the PCR products into plasmid vectors. At least 90 clones/tissue specimen were screened for mutations by single-strand conformational polymorphism analysis. DNA from abnormally migrating single-strand conformational polymorphism samples was sequenced to confirm mutations. Missense mutations in exon 5, 7, or 8 were detected in 9 of 20 immunopositive pairs and in 1 of 6 immunonegative pairs. A marked heterogeneity of mutations in primary prostate cancer was apparent. The frequency of p53 mutations was greater in the metastases than in the primary tumors. In three immunopositive pairs, the same p53 mutation was demonstrated at a low frequency in the primary tumor but was demonstrated at a greater frequency in the metastasis, indicating relatively limited clonal expansion of cells harboring specific p53 mutations in the primary tumor, yet significant clonal growth at metastatic sites as determined by this novel method.  相似文献   
995.
Defining the most appropriate conditions for strengthening the retention of endothelial cells (ECs) by small-diameter prosthetic endothelialized grafts is indispensable to their clinical application. The incubation time after seeding is one of the most important factors in EC retention. The effects of different postincubation times (0, 2, 4, 8, 16, 24, and 36 hr) on EC monolayers on two different types of graft, fibronectin-coated expanded polytetrafluoroethylene (ePTFE) and collagen-coated knitted Dacron grafts (4 mm x 5 cm) were examined. In situ counting of ECs on the grafts was performed by light microscopy. The percentage cell retention was calculated by dividing the cell counts for grafts exposed to pulsatile flow for 90 min by those for control grafts. To characterize the EC coverage of the grafts, scanning electron microscopy was also performed. The average cell density of control grafts ranged from 5.59 +/- 1.1 to 6.69 +/- 1.5 x 10(4) cells/cm2 and did not differ according to the kind of graft or incubation time. The knitted Dacron grafts showed the maximal cell retention (88 +/- 5%) after incubation for 8 hr, whereas ePTFE grafts did so after 24 hr (83 +/- 6%). Scanning electron microscopic examination after incubation for 8 hr revealed that the density of human ECs on the surfaces of ePTFE and Dacron grafts differed, although there was no morphological difference between the ECs on the two types of graft. Knitted Dacron grafts achieved a high percentage retention in a shorter time than ePTFE grafts.  相似文献   
996.
We investigated the reconstitutive potential of haematopoietic progenitor cells collected in autologous whole blood during multicycle dose-intensified chemotherapy. Forty patients with metastatic solid tumours were treated with up to six cycles of cisplatin and escalating doses of ifosfamide every 14 days. Cisplatin was administered in 3% sodium chloride over 3 h, followed by ifosfamide over 24 h and mesna over 36 h. The first cohort of patients received granulocyte colony-stimulating factor (G-CSF) days 4-14. Once dose-limiting toxicity was reached in cohort 1, the study continued with a second cohort of patients, in whom, in addition to G-CSF on days 4-14, 500 ml of G-CSF and chemotherapy-'primed' whole blood was collected on day 15, i.e. on day 1 of treatment cycles two to six, before cisplatin administration. This volume of blood was kept unprocessed at 4 degrees C and reinfused 20-24 h after the completion of ifosfamide. In cohort 1, dose-limiting toxicity (DLT) was reached at ifosfamide 6.0 g m(-2) with two out of six of the patients developing neutropenic fever. Although in cohort 2 no neutropenic fever was encountered, neither the frequency nor the duration of grade 4 neutropenia and thrombocytopenia were reduced. Cumulative asthenia resulted in DLT at 7.0 g m(-2). The median number of CD34+ cells in 500 ml of whole blood after the first cycle (i.e. at start of cycle 2) was 1.15 x 10(6) kg(-1). This number was significantly greater after the second cycle (2.06 x 10(6) kg(-1), P = 0.01) and then gradually decreased after cycles three to six. After storing whole blood, the number of CD34+ cells had not decreased (median + 10%). We conclude that the method of combined bone marrow support by G-CSF and haematopoietic progenitor cells in autologous whole blood collected before each cycle of a 2-weekly regimen of cisplatin-ifosfamide does not result in clinically measurable reduced bone marrow toxicity compared with what can be expected by the use of G-CSF alone.  相似文献   
997.
DNA fingerprinting using a nonisotopically labeled minisatellite probe provided a valuable technique for genetic monitoring/quality control of laboratory rodents. Each of 12 inbred rat strains had a unique fingerprint pattern, and colonies separated for over 20 years had identical or nearly identical patterns. Strain LOU/Iap, which is known to have been genetically contaminated in the past, was clearly different from strain LOU/CN, supporting previous findings of studies using biochemical markers. Inbred strains of mice were also found to differ from each other. The F1 hybrid between C57BL/6 and CBA/Ca could not be distinguished from C57BL/6 by using DNA fingerprints, although they could be distinguished by using biochemical markers. Some congenic strains differed from their inbred partner. A suspected genetic contamination of MRL/Mp-lpr mice could not be detected in a sample of the breeding colony by using biochemical markers; however, DNA fingerprints from the suspect animals clearly demonstrated genetic segregation. DNA fingerprinting will be of particular value in investigating suspected problems as only a small sample of fresh, frozen, or ethanol-preserved tissue is needed. Thus, the actual suspect animals can be studied, rather than samples from a breeding colony from which contaminated animals may already have been eliminated.  相似文献   
998.
999.
Bovine adrenocortical cytochrome P450scc (CYP11A1) was selectively modified with diiodofluorescein iodoacetamide (DIFIA). Only Cys264 is labeled in the P450 polypeptide chain. The modification significantly affected the cholesterol-hydroxylating activity in the reconstituted system containing NADPH, adrenodoxin reductase, adrenodoxin, and soluble or membrane-bound P450scc. The inhibitory effect correlates with decreased affinity of cytochrome P450scc to intermediate electron carrier, adrenodoxin. Cytochrome P450scc is modified in liposomes and the modified membrane-bound protein is cleaved by trypsin forming two large fragments F1 and F2 corresponding to the N- and C-terminal regions of the molecule. The data indicate that the Cys264-containing region of the cytochrome P450scc molecule is exposed to the surface of protein globule, located outside of the membrane, and can participate in protein-protein interactions.  相似文献   
1000.
The effect of some new 1-[3-(aroylo)] and one 1-[3-[aryloxy)]-propyl aminothiazole on inflammation was investigated in the carrageenin-induced mouse paw edema (36-58% edema inhibition). In addition they exhibited significant analgesic activity (55-80.6%) in the writhing test. Their antioxidant activity in vitro using the stable free radical 1.1-diphenyl-2-picrylhydrazyl (DPPH), was determined. Antiproteolytic ability and beta-glucuronidase inhibition have been studied. The tested compounds did not inhibit soybean 12-lipoxygenase. RM values, as an expression of lipophilicity, were determined.  相似文献   
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