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91.
DJ Kereiakes AM Lincoff DP Miller JE Tcheng CF Cabot KM Anderson HF Weisman RM Califf EJ Topol 《Canadian Metallurgical Quarterly》1998,97(9):857-864
BACKGROUND: Recent studies indicate that eradication of Helicobacter pylori might prevent peptic ulcer formation in patients treated with non-steroidal anti-inflammatory drugs (NSAIDs). On the other hand, gastric adaptation after repeated exposures to aspirin (ASA) is well documented but the influence of H. pylori on this process remains to be elucidated. AIM: To compare gastric damage and adaptation following repeated exposures to ASA in a group of patients with H. pylori infection, before and after eradication of the bacterium, and in H. pylori-negative controls. METHODS: Eight healthy volunteers without H. pylori infection and eight patients with duodenal ulcer (DU) history and H. pylori infection before and after H. pylori eradication were given ASA 2 g/day for a period of 14 days. Mucosal damage was evaluated by endoscopy and histology of biopsy samples. Gastric microbleeding, DNA synthesis in the gastric mucosa and mucosal expression, as well as luminal content of transforming growth factor-alpha (TGFalpha) were determined on days 0, 3, 7 and 14 of the ASA course. RESULTS: In all patients aspirin-induced gastric damage reached a maximum on day 3. In H. pylori-positive patients, this damage was maintained at a similar level up to day 14, whereas in H. pylori-negative controls and H. pylori-eradicated patients this damage significantly lessened on day 14 and was accompanied by elevated DNA synthesis as well as increased mucosal expression and luminal release of TGFalpha. 相似文献
92.
CJ Quaife EJ Kelly BA Masters RL Brinster RD Palmiter 《Canadian Metallurgical Quarterly》1998,148(1):148-157
Mice express four distinct metallothioneins (MTs) that have similar metal-binding properties. MT-I and MT-II are expressed coordinately in most organs, whereas MT-III is expressed predominantly in a subset of neurons and MT-IV is expressed in certain stratified epithelia. The restricted expression of MT-III suggests that it may severe a specialized function. To test this hypothesis, transgenic mice were generated that express MT-III in the wider expression domain of MT-I. Similar transgenic lines expressing extra MT-I under the same regulation were generated as controls for the effect of over-expression of MT. Transgenic mice that express MT-III ectopically frequently die at 2-3 months of age. The pancreata of moribund mice were abnormally small and histological examination, at various ages, revealed a progressive degeneration of the acinar cells. At early stages multifocal acinar cell eosinophilia and swollen nuclei were seen and this pathology progressed to multifocal acinar cell necrosis and fibrosis. The terminal stages were characterized by a loss of the acinar compartment, leaving the islets embedded in a fibrotic remnant. Other organs of these mice were grossly and histologically normal. All organs examined from mice expressing excess MT-I were unremarkable even though expression of either MT-I or MT-III transgenes resulted in similar accumulations of zinc and copper in the pancreata. This study indicates that pancreatic acinar cells are unusually sensitive to chronic expression of MT-III. The mechanism by which MT-III disrupts pancreatic function is unclear, but the results provide further evidence that MT isoforms exhibit distinct properties and probably serve distinct biological functions. 相似文献
93.
EJ Shillitoe S Noonan CC Hinkle FC Marini RM Kellman 《Canadian Metallurgical Quarterly》1998,5(3):176-182
Considerable basic research, mostly in the past 20 years, has elicited greatly increased knowledge concerning the structure and function of cell adhesion molecules. Scores of individual adhesion molecules have been identified and categorized as to major structural features, ligands recognized, and pattern of expression. Recent attention has been focused on the interaction of cell adhesion molecules with intracellular components, and the role of cell adhesion molecules in mediating cell signal transduction. Ongoing efforts to develop specific pharmacological agonists and antagonists for adhesion molecules holds great promise in clinical medicine. Abciximab (Reopro), a monoclonal antibody inhibitor of the platelet integrin alpha IIb beta 3, is currently approved and available to improve vessel patency in patients undergoing angioplasty. Similar approaches to develop adhesion-based therapies to block angiogenesis, tumor progression, and/or metastasis are under development and hold promise for patients with cancer. 相似文献
94.
Quantitative buffy coat (QBC) analysis has been reported to have a high degree of methodical sensitivity in the detection of human filariasis. This study was conducted to evaluate its usefulness in the diagnosis of filariasis using a Dirofilaria immitis/dog model. By necropsy of 244 stray dogs, 40.6% of the animals were found to harbor 1-58 worms of D. immitis (mean 6.5 +/- 8.4 worms/infected dog). The QBC analysis and thick blood smear (TBS) method detected microfilaremia in 31.6% and 21.3% of these dogs, respectively. The results of these two methods were highly correlated with the presence of bisexual worms in the dogs. The QBC analysis was more sensitive (55% versus 39%) and efficient (79% versus 72%) than the conventional TBS method. However, accurate speciation of the microfilariae was impossible using the QBC analysis. Although this technique is more sensitive, simpler, and less time-consuming and does not require as much skill or experience in comparison with the conventional TBS method, the failure in speciation of the parasites may limit its usefulness. 相似文献
95.
GA Christoforidis BA Mehta JL Landi EJ Czarnecki RA Piaskowski 《Canadian Metallurgical Quarterly》1998,40(10):636-643
Spontaneous intracranial hypotension is an unusual syndrome of postural headache and low cerebrospinal fluid pressure without an established cause. We present four cases, analyze those previously reported in the literature, examine the MRI, CT, angiographic and cisternographic finding and discuss the clinical picture, proposed pathophysiologic mechanisms and potential treatment. 相似文献
96.
97.
Protein shedding, or the proteolytic cleavage of a protein from the surface of a cell, is emerging as an important mechanism in the regulation of cellular activity but it is poorly understood. Growing evidence suggesting that protein shedding and protein function are closely linked may lead to new strategies for the treatment of a wide range of diseases. 相似文献
98.
EJ Roth AW Heinemann LL Lovell RL Harvey JR McGuire S Diaz 《Canadian Metallurgical Quarterly》1998,79(3):329-335
Migration of non-volatile and volatile compounds from 'microwave and roasting bags' (MRB), made of Nylon 6,6 (and some Nylon 6), into chicken meat, skin, and juices during roasting (200 degrees C/2 h) in a conventional oven was determined. For measurement of migration of non-volatile compounds, cooked chicken was freeze-dried, extracted with methanol after addition of 2-azacyclononane (internal standard) and the extract cleaned-up using liquid-solid adsorption chromatography (silica gel). High performance liquid chromatography (HPLC) in the reverse phase mode using a linear gradient of methanol in water was used to quantify seven Nylon 6 and Nylon 6,6 cyclic monomers and oligomers of molecular mass up to 678 daltons. Migration into chicken was 7.48 micrograms/g (8.26 mg/bag; 3.94 micrograms/cm2), 16% of the total non-volatile compounds contained in the MRB material. Individual migrants were also quantified. Migration of one volatile compound, 2-cyclopentyl cyclopentanone, into the roast chicken parts was measured. Extraction with diethyl ether, using a modified Likens-Nickerson system of concurrent steam distillation-solvent extraction with an internal standard (cyclohexanone) was performed for 10 h. Gas chromatography/mass spectrometry (GC/MS) in the selected ion mode (SIM) was used for quantification. An average of 14.0 (+/- 4.36) micrograms/bag (or micrograms/chicken) migrated, being 0.08% of the total 2-cyclopentyl cyclopentanone present in MRB. Loss of volatile compounds to the atmosphere is believed to have occurred since there was another, more volatile compound (cyclopentanone), present in MRB, at levels higher than 2-cyclopentyl cyclopentanone, but this was not detected in roast chicken. In general, the transference of MRB components into roast chicken can be considered not to present a hazard. 相似文献
99.
SBMV-S is a resistance-breaking mutant of an Arkansas isolate of the bean strain of southern bean mosaic virus (SBMV-BARK) that is able to move systemically in Phaseolus vulgaris cvs. Pinto and Great Northern, whereas the wild-type SBMV-BARK causes local necrotic lesions and is restricted to the inoculated leaves of these hosts. Sequence analysis of the 4136 nucleotide genomes of SBMV-BARK and SBMV-S revealed seven nucleotide differences, but only four deduced amino acid changes. A single amino acid change occurred in the C-terminal region of the putative RNA-dependent RNA polymerase and three differences were identified in the N-terminal portion of the virus coat protein. SBMV-BARK and SBMV-S were compared with other sobemoviruses and were found to contain a high level of nucleotide sequence identity (91.3%) to SBMV-B. Unlike SBMV-B however, SBMV-BARK and SBMV-S contained four putative overlapping open reading frames, making them more similar in genome organization to the cowpea strain, SBMV-C. The possibility exists that mutations or even errors, that resulted in mis-identification of open reading frames, occurred in previously published information on nucleotide sequence and genomic organization for SBMV-B. 相似文献
100.
AS Lages KC Silva AL Miranda CA Fraga EJ Barreiro 《Canadian Metallurgical Quarterly》1998,8(2):183-188
OBJECTIVE: To study the effect of adjuvant chemotherapy after curative hepatic resection in patients with hepatocellular carcinoma. DESIGN: A randomized controlled trial. SETTING: A tertiary referral center. PATIENTS: During a 54-month period, 142 patients with hepatocellular carcinoma underwent hepatic resection at 1 institution. Sixty-six patients who survived the operation and had no demonstrable evidence of residual disease on ultrasonographic examination and hepatic angiographic testing at 1 month after surgery agreed to participate in the study. The median follow-up time was 28.3 months. INTERVENTION: Thirty patients received a combination of intravenous epirubicin hydrochloride (8 doses of 40 mg/m2 each at 6-week intervals) and transarterial chemotherapy using an emulsion of iodized oil and cisplatin (3 courses with a maximum dose of 20 mL each at 2-month intervals). Thirty-six patients had no adjuvant treatment. MAIN OUTCOME MEASURES: Recurrence rate and disease-free survival. RESULTS: A total of 138 courses of intravenous epirubicin was given to the 30 patients. Sixty-one courses of transarterial chemotherapy were given to only 29 of the 30 patients assigned to the treatment group, because the hepatic artery in 1 patient was thrombosed. Six patients (20%) had chemotherapy-related complications with no mortality. Twenty-three of 30 patients in the treatment group and 17 of 36 patients in the control group had recurrences (P=.01). Patients who received adjuvant chemotherapy had a higher incidence of extrahepatic metastases (11 patients vs 5 patients; P=.03). The respective disease-free survival rates at 1, 2, and 3 years were 50%,36%, and 18% for the treatment group and 69%, 53%, and 48% for the control group (P=.04). CONCLUSION: In a group of patients who underwent curative resection of hepatocellular carcinoma, postoperative adjuvant chemotherapy using the present regimen was associated with more frequent extrahepatic recurrences and a worse outcome. 相似文献