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891.
892.
JA Burger A Ochs K Wirth DP Berger R Mertelsmann R Engelhardt M Roessle K Haag 《Canadian Metallurgical Quarterly》1997,8(2):200-202
BACKGROUND: The increase in portal vascular resistance is a significant complication of metastatic disease to the liver or locally advanced cancer, e.g., biliary cancer. PATIENTS AND METHODS: This paper describes the successful palliative treatment of two cancer patients with portal hypertension presenting with the symptoms of tense ascites, mesenteric congestion, and severe variceal bleeding. By creating a stenttract between a hepatic vein and a main branch of the portal vein and/or by placing an extendable stent into the portal vein, the transjugular intrahepatic portosystemic stent-shunt (TIPS) technique was used to decompress the portovascular system. RESULTS: The TIPS-technique offers a new, safe and effective palliation for malignant portal hypertension. In both patients, the symptoms of the portal hypertension disappeared after the procedure. This was accompanied by a significant improvement of the patients performance status allowing an early ambulation. CONCLUSION: Our findings demonstrate the feasibility and effectiveness of the TIPS procedure as a minimal invasive treatment for portal vein decompression in selected tumor patients. 相似文献
893.
The G1 glycoprotein of California encephalitis (CE) virus plays a critical role in the infection of mosquito and mammalian cells. We found that CE virus enters baby hamster kidney (BHK-21) and Aedes albopictus (C6/36) cells by the endocytic pathway. Ammonium chloride, a lysosomotropic amine that prevents release of virus from endosomes, inhibited infection of both cell types when added within 10 min after viral adsorption. In addition, infected cells formed polykaryons when the extracellular pH was lowered to 6.3; optimal fusion occurred at pH 5.8 and 6.0 (C6/36 and BHK-21 cells, respectively). Two neutralizing G1 MAba, 6D5.5 and 7D4.5, inhibited low pH-induced syncytia formation without affecting viral attachment, suggesting a role for G1 in viral entry. Since viral fusion proteins have been demonstrated to undergo conformational changes at low pH, acid-induced changes in G1 and G2 were assessed. While both G1 and G2 demonstrated low pH-induced alterations in detergent binding, only G1 displayed an altered protease cleavage pattern at the fusion pH. These results indicate that the G1 protein of CE virus undergoes conformational changes necessary for low pH-mediated entry into both mosquito and mammalian cells. 相似文献
894.
We have examined the formation of hydroxyphenols, nitrophenols, and the minor products 4-nitrosophenol, benzoquinone, 2,2'-biphenol, and 4,4'-biphenol from the reaction of peroxynitrite with phenol in the presence and absence of added carbonate. In the absence of added carbonate, the product yields of nitrophenols and hydroxyphenols have different pH profiles. The rates of nitration and hydroxylation also have different pH profiles and match the trends observed for the product yields. At a given pH, the sum of the rate constants for nitration and hydroxylation is nearly identical to the rate constant for the spontaneous decomposition of peroxynitrite. The reaction of peroxynitrite with phenol is zero-order in phenol, both in the presence and absence of added carbonate. In the presence of added carbonate, hydroxylation is inhibited, whereas the rate of formation and yield of nitrophenols increase. The combined maximum yield of o- and p-nitrophenols is 20 mol% (based on the initial concentration of peroxynitrite) and is about fourfold higher than the maximal yield obtained in the absence of added carbonate. The o/p ratio of nitrophenols is the same in the presence and absence of added carbonate. These results demonstrate that hydroxylation and nitration occur via two different intermediates. We suggest that the activated intermediate formed in the isomerization of peroxynitrous acid to nitrate, ONOOH*, is the hydroxylating species. We propose that intermediate 1, O=N-OO-CO2-, or secondary products derived from it, is (are) responsible for the nitration of phenol. The possible mechanisms responsible for nitration are discussed. 相似文献
895.
The combination of the techniques of expert systems and neural networks has the potential of producing more powerful systems, for example, expert systems able to learn from experience. In this paper, we address the combinatorial neural model (CNM), a kind of fuzzy neural network able to accommodate in a simple framework the highly desirable property of incremental learning, as well as the usual capabilities of expert systems. We show how an interval-based representation for membership grades makes CNM capable of reasoning with several types of uncertainty: vagueness, ignorance, and relevance commonly found in practical applications. In addition, we show how basic functions of expert systems such as inference, inquiry, censorship of input information, and explanation may be implemented. We also report experimental results of the application of CNM to the problem of deforestation monitoring of the Amazon region using satellite images 相似文献
896.
R Kalluri K Meyers A Mogyorosi MP Madaio EG Neilson 《Canadian Metallurgical Quarterly》1997,8(11):1795-1800
A 68-year-old Caucasian woman presented to the hospital with nodular pulmonary infiltrates and acute renal failure. Wegener's granulomatosis was initially considered to be most likely because of the presence of increased serum levels of c-anti-neutrophil cytoplasmic antibodies (c-ANCA). A consultation through the Internet after a renal biopsy demonstrated crescentic, necrotizing glomerulonephritis and linear deposits of immunoglobulin G (IgG) and complement C3, typical of anti-glomerular basement membrane (GBM) disease. Hemodialysis was instituted; however, the patient suddenly developed a massive cerebral hemorrhage and died before full therapy could take effect. Postmortem analysis of the patient's sera revealed high titers of IgG against the alpha 3 NC1 domain of type IV collagen. Serologic evidence of both p-ANCA and anti-GBM antibodies are becoming more frequently recognized in the setting of rapidly progressive glomerulonephritis. The patient reported here had the unusual combination of c-ANCA antibodies with anti-GBM disease, and this association raises complex questions regarding the pathogenesis of this type of renal injury. 相似文献
897.
898.
OBJECTIVE: To evaluate the efficacy of terazosin, an alpha-blocker, for the treatment of idiopathic oligozoospermia. PATIENTS AND METHODS: Thirty couples with infertility whose only detectable abnormality was male idiopathic subfertility entered the study. The diagnosis of idiopathic subfertility in all males studied, aged 26 to 38 years (mean 28.2 years), was confirmed after exclusion of any iatrogenic, systemic, congenital, infectious, autoimmune or endocrinological cause. In order to start with a baseline value before the study, at least three semen samples were evaluated in accordance with the WHO recommendation. Before initiation of treatment, blood samples were drawn for measurement of FSH, LH, testosterone, prolactin, dihydrotestosterone, and estradiol. Fifteen randomly selected patients (Group A) received 2 mg/d of alpha-blocker (terazosin), while another 15 (Group B) were administered an identically packed placebo tablet. Both groups received therapy for 6 months. RESULTS: The mean seminal volume changed insignificantly between the two groups (4.15 +/- 1.95 vs. 4.10 +/- 1.95). There was a statistically significant increase of the sperm concentration in patients who received the alpha-blocker compared to those receiving placebo (24.76 +/- 9.45 vs. 13.15 +/- 11.55 millions/mL; P < .001). No improvement of the mean percentage of abnormal spermatozoa was observed in the treated patients, nor a statistically significant difference of sperm motility in the treated group compared to the placebo group. Side effects were not observed in the patients receiving terazosin treatment, or were so minimal that therapy was continued. The pregnancy rates did not differ between the two groups to a statistically significant degree. CONCLUSION: The administration of terazosin to patients with idiopathic oligozoospermia has a demonstrably positive effect, especially on sperm concentration. 相似文献
899.
900.
D Ben-Yehuda S Krichevsky EA Rachmilewitz A Avraham GA Palumbo F Frassoni D Sahar H Rosenbaum O Paltiel M Zion Y Ben-Neriah 《Canadian Metallurgical Quarterly》1997,90(12):4918-4923
We previously reported that the abl promoter (Pa) undergoes de novo DNA methylation in the course of chronic myelocytic leukemia (CML). The clinical implications of this finding are the subject of the present study in which samples of CML patients, including a group treated with interferon alpha (IFNalpha) were surveyed. The methylation status of the abl promoter was monitored by polymerase chain reaction (PCR) amplification of the Pa region after digestion with several site-methylation sensitive restriction enzymes. Some 74% of the DNA samples from blood and marrow drawn in the chronic phase were nonmethylated, similar to control samples from non-CML patients. The remaining 26% were partially methylated in the abl Pa region. The latter samples were derived from patients who were indistinguishable from the others on the basis of clinical presentation. Methylated samples were mostly derived from patients known to have a disease of longer duration (26 months v 7.5 months, P = .01). Samples of 30 IFNalpha-treated patients were sequentially analyzed in the course of treatment. Fifteen patients with no evidence of Pa methylation before treatment remained methylation-free. The remainder, who displayed Pa methylation before treatment, reverted to the methylation-free status. The outcome is attributed to IFNalpha therapy, as the Pa methylation status was not reversed in any of the patients treated with hydroxyurea. Methylation of the abl promoter indicates a disease of long-standing, most likely associated with a higher probability of imminent blastic transformation. It appears to predict the outcome of IFNalpha therapy far better than the cytogenetic response. 相似文献