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51.
JJ Holland 《Canadian Metallurgical Quarterly》1996,14(4):431-432
52.
TV Hoang EU Choe HL Lippton AL Hyman LM Flint JJ Ferrara 《Canadian Metallurgical Quarterly》1996,61(2):330-338
To characterize the mesenteric alpha1- and alpha2-adrenoceptor populations in newborn piglets, an extracorporeal circuit was established to control intestinal blood flow in 0- to 2-day old and 10- to 14-day old animals. In both groups, alpha-adrenoceptor activation was first documented by observing dose-dependent increases in mesenteric perfusion pressure after intramesenteric arterial injection of alpha-adrenoceptor agonists. In the 10- to 14-day old piglets, mesenteric vasoconstrictor responses to alpha1-adrenoceptor agonists (methoxamine and norepinephrine) and an alpha2-adrenoceptor agonist (BHT-933) were each blunted (P < 0.05, analysis of variance) by peripheral intravenous injections of prazosin (an alpha1-adrenoceptor antagonist) and yohimbine (an alpha2-adrenoceptor antagonist), respectively. The mesenteric vasoconstrictor responses to those agonists were not significantly attenuated by prazosin or yohimbine in 0- to 2-day old animals, nor were they blunted by YM-12617 (alpha1-adrenoceptor antagonist) or idazoxan (alpha2-adrenoceptor antagonist)--compounds that are structurally unrelated to prazosin and yohimbine, respectively. In addition, mesenteric vasoconstrictor responses to other known vasoconstrictor agents--angiotensin II, neuropeptide Y, and a thromboxane A2 mimic (U-46619)--were not effected in either age group by prazosin or yohimbine, implying these agents act independently of alpha-adrenoceptor mechanisms. These data suggest that (1) there exists functional mesenteric alpha1- and alpha2-adrenoceptor-like activity in 10- to 14-day old piglets that, in 0- to 2-day old animals, is not specifically expressed; and (2) mesenteric alpha-adrenoceptor function becomes more selective as newborn piglets mature. 相似文献
53.
JJ Callaghan GS Tooma JP Olejniczak DD Goetz RC Johnston 《Canadian Metallurgical Quarterly》1996,(333):118-125
The senior authors' initial experience with primary hybrid hip replacement in patients with osteoarthritis was studied to evaluate the efficacy of the procedure. Hybrid total hip arthroplasty (uncemented Harris-Galante acetabular component and cemented Iowa precoated femoral component) was performed in 131 consecutive, nonselected hips in 118 patients with the diagnosis of primary osteoarthritis. Followup was performed at 8 to 9 years after the procedure. The average age at the time of the procedure was 68 years (range, 45-87 years). There were 50 men (55 hips) and 68 women (76 hips). At final followup 19 patients (22 hips) had died. The femoral component had been revised for aseptic loosening in 8 hips (6.1%). One additional hip showed definite radiographic loosening. Hence, the prevalence of radiographic femoral failure was 6.9% (9 hips). No acetabular component had been revised for aseptic loosening and no acetabular component had migrated. The senior author continues to perform hybrid total hip arthroplasty in all patients with primary osteoarthritis. However, design modifications have been made in the femoral component that is used. 相似文献
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JJ Bull MR Badgett HA Wichman JP Huelsenbeck DM Hillis A Gulati C Ho IJ Molineux 《Canadian Metallurgical Quarterly》1997,147(4):1497-1507
Replicate lineages of the bacteriophage phiX 174 adapted to growth at high temperature on either of two hosts exhibited high rates of identical, independent substitutions. Typically, a dozen or more substitutions accumulated in the 5.4-kilobase genome during propagation. Across the entire data set of nine lineages, 119 independent substitutions occurred at 68 nucleotide sites. Over half of these substitutions, accounting for one third of the sites, were identical with substitutions in other lineages. Some convergent substitutions were specific to the host used for phage propagation, but others occurred across both hosts. Continued adaptation of an evolved phage at high temperature, but on the other host, led to additional changes that included reversions of previous substitutions. Phylogenetic reconstruction using the complete genome sequence not only failed to recover the correct evolutionary history because of these convergent changes, but the true history was rejected as being a significantly inferior fit to the data. Replicate lineages subjected to similar environmental challenges showed similar rates of substitution and similar rates of fitness improvement across corresponding times of adaptation. Substitution rates and fitness improvements were higher during the initial period of adaptation than during a later period, except when the host was changed. 相似文献
57.
SI Alexander SB Younes JJ Yunis D Zurakowski N Mirza D Dubey MP Drew WE Harmon EJ Yunis 《Canadian Metallurgical Quarterly》1997,63(12):1756-1761
BACKGROUND: Recipient antidonor cytotoxic T-cell activity has been associated with graft loss and acute rejection in renal allograft recipients. The role of immunologic mechanisms in the development of chronic graft rejection is controversial. We analyzed all living related renal transplants performed at Children's Hospital (Boston, MA) from 1983 to 1995 to assess whether cell-mediated cytotoxicity, determined in vitro and measured before transplantation, was predictive of chronic rejection. METHODS: Eighty-three patients were studied retrospectively. Fifty-seven patients with one haplotype-matched renal transplants from living related donors were studied to determine the association between cell-mediated lympholysis (CML) level, acute rejection, chronic rejection, and graft failure. Acute rejection was defined by the decision to treat. Chronic rejection was defined by histology and/or the absolute serum creatinine value using an increasing serum creatinine level >1.0 mg/dl for children less than 3, a creatinine level >1.5 mg/dl for children between 3 and 10 years of age, and a creatinine level >2.0 mg/dl for children above 10 years of age. Return to dialysis or retransplantation was considered graft failure. RESULTS: Of the 57 haploidentical patients, there were 33 males and 24 females. The mean age at transplant was 11.1 years (SD=6.7). Twelve patients developed chronic rejection, 24 patients developed acute rejection, and 7 patients had graft failure. Pretransplant cytotoxic T lymphocyte activity was associated with chronic rejection (P=0.001) and graft failure (P=0.013) but only marginally with acute rejection (P=0.058). Controlling for age and sex, Cox's proportional hazards model revealed that CML level was predictive of time to chronic rejection (P<0.01) but not acute rejection (P=0.11). It was estimated that every 1-unit increase in CML level raises the monthly risk of chronic rejection by 7%. Ten children received HLA-identical kidneys from their siblings. There were no episodes of chronic rejection after 5 years. Two patients with high CML levels had episodes of acute rejection; both patients responded to treatment. CONCLUSION: Our data demonstrate an association between pretransplant cell-mediated cytotoxicity and the occurrence of chronic rejection in living related one-haploidentical renal transplants in pediatric patients. 相似文献
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59.
JM Vaugeois JJ Bonnet D Duterte-Boucher J Costentin 《Canadian Metallurgical Quarterly》1993,230(2):195-201
We have recently found that allogenic bone marrow transplantation (BMT) can be used to treat lupus nephritis in NZB x NZW F1 (B/W F1) and BXSB mice. To elucidate why and how glomerular damage is repaired, serial renal biopsies were carried out using B/W F1 mice before, and after BMT. Donor-derived B cells and macrophages with normal functions developed two weeks after BMT, whereas donor-derived functional T cells were generated after seven weeks of BMT. Visceral epithelial cells as well as macrophages in the glomeruli were activated (probably by T cell-derived lymphokines) at this time; they showed marked phagocytic activity, resulting in clearance of immune complexes (ICs) and repair of damaged basement membranes. These results suggest that normal T cell functions, which have the capacity to activate macrophages and epithelial cells, are essential in repairing IC-mediated glomerular damage. 相似文献
60.
MK Gutniak L Juntti-Berggren PM Hellstr?m A Guenifi JJ Holst S Efendic 《Canadian Metallurgical Quarterly》1996,19(8):857-863
OBJECTIVE: To investigate the acute effects of glibenclamide and glucagon-like peptide I (GLP-I) and their combination in perfused isolated rat pancreas and in patients with secondary failure to sulfonylureas. RESEARCH DESIGN AND METHODS: Rat islets were perfused with 10 nmol/l GLP-I in combination with 2 mumol/l glibenclamide. In human experiments, GLP-I (0.75 pmol. kg-1.min-1) was given as a continuous infusion during 240 min, while glibenclamide (3.5 mg) was administered orally. Eight patients participated in the study (age 57.6 +/- 2.7 years, BMI 28.7 +/- 1.5 kg/m2, mean +/- SE). In all subjects, blood glucose was first normalized by insulin infusion administered by an artificial pancreas (Biostator). RESULTS: GLP-I increased the insulinotropic effect of glibenclamide fourfold in the perfused rat pancreas. In human experiments, treatment with GLP-I alone and in combination with glibenclamide significantly decreased basal glucose levels (5.1 +/- 0.4 and 4.5 +/- 0.1 vs. 6.0 +/- 0.3 mmol/l, P < 0.01), while with only glibenclamide, glucose concentrations remained unchanged. GLP-I markedly decreased total integrated glucose response to the meal (353 +/- 60 vs. 724 +/- 91 mmol.l-1. min-1, area under the curve [AUC] [-30-180 min], P < 0.02), whereas glibenclamide had no effect (598 +/- 101 mmol.l-1. min-1, AUC [-30-180 min], NS). The combined treatment further enhanced the glucose lowering effect of GLP-I (138 +/- 24 mmol. l-1.min, AUC [-30-180 min], P < 0.001). GLP-I, glibenclamide, and combined treat-stimulated meal-induced insulin release as reflected by insulinogenic indexes (control 1.44 +/- 0.4; GLP-I 6.3 +/- 1.6, P < 0.01; glibenclamide 6.8 +/- 2.1, P < 0.01; combination 20.7 +/- 5.0, P < 0.001). GLP-I inhibited basal but not postprandial glucagon responses. Using paracetamol as a marker for gastric emptying rate of the test meal, treatment with GLP-I decreased gastric emptying at 180 min by approximately 50% compared with the control subjects (P < 0.01). CONCLUSIONS: In acute experiments on overweight patients with NIDDM, GLP-I exerted a marked antidiabetogenic action on the basal and postprandial state. The peptide stimulated insulin, suppressed basal glucagon release, and prolonged gastric emptying. The glucose-lowering effect of GLP-I was further enhanced by glibenclamide. This action may be at least partially accounted for by a synergistic effect of these two compounds on insulin release. Glibenclamide per se enhanced postprandial but not basal insulin release and exerted a less pronounced antidiabetogenic effect compared with GLP-I. 相似文献