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941.
MS Keshavan GL Haas CE Kahn E Aguilar EL Dick NR Schooler JA Sweeney JW Pettegrew 《Canadian Metallurgical Quarterly》1998,32(3-4):161-167
Accumulating evidence suggests alterations in brain structure, especially in the prefrontal and temporal cortex, in schizophrenia. Previous studies examining the progression of brain structural alterations in schizophrenia have led to conflicting results. Morphometric studies of the superior temporal gyrus (STG) volumes were conducted in a series of neuroleptic-naive first-episode schizophrenic patients, non-schizophrenic first-episode psychotic patients, and matched healthy controls. Three-dimensional MRI scans were carried out in these subjects before and after one year of treatment. Volume reductions were seen at baseline in the left superior temporal gyrus (adjusted for intracranial volume) in both of the patient groups. Pretreatment illness duration was inversely related to the volume of the left superior temporal gyrus; this relation was confined to males. One-year follow-up MRI investigations in a smaller subset of patients suggested that the STG volume reductions may be reversible. No significant changes were noted in the STG volumes in matched healthy controls who were also scanned at baseline as well as at one-year follow-up. These findings have implications for understanding the nature of the neuropathological processes in early schizophrenia, as well as the potential impact of early treatment. 相似文献
942.
The histidine permease of Salmonella typhimurium is an ABC transporter (traffic ATPase). The liganded soluble receptor, the histidine-binding protein HisJ, interacts with the membrane-bound complex HisQMP2 and stimulates its ATPase activity, which results in histidine translocation. In this study, we utilized HisJ proteins with mutations in either of the two lobes and wild type HisJ liganded with different substrates to show that each lobe carries an interaction site and that both lobes are involved in inducing (stimulating) the ATPase activity. We suggest that the spatial relationship between the lobes is one of the factors recognized by the membrane-bound complex in dictating the efficiency of the induction signal and of translocation. Several of the key residues involved have been identified. In addition, using constitutive ATPase mutants, we show that the binding protein provides some additional essential function(s) in translocation that is independent of the stimulation of ATP hydrolysis, and one possible mechanism is proposed, which includes the notion that liganded HisJ has different optimal conformations for signaling and for translocation. 相似文献
943.
PURPOSE: To compare pneumatic retinopexy and scleral buckling for repair of primary rhegmatogenous retinal detachment with respect to visual outcome, single-procedure reattachment rate, and development of proliferative vitreoretinopathy. METHODS: A consecutive series of eyes initially treated with pneumatic retinopexy (n = 56) between March 1986 and February 1996 were compared with a selected group of eyes treated with scleral buckling (n = 86) with similar location and distribution of retinal breaks and absence of proliferative vitreoretinopathy. A regression model was developed to adjust for underlying differences between treatment groups, resulting in a cohort of 50 eyes in each group for final comparison. A minimum follow-up of 6 months was obtained. RESULTS: Single-procedure reattachment rate was significantly higher for scleral buckle eyes (42 of 50 eyes, 84%) than for pneumatic retinopexy eyes (31 of 50 eyes, 62%; P < or = .01). Correspondingly, reoperation rate was significantly higher for pneumatic retinopexy eyes (19 of 50 eyes, 38%) than for scleral buckle eyes (7 of 50 eyes, 14%; P < or = .01). Multiple regression analysis evaluating perioperative factors demonstrated that the use of pneumatic retinopexy was the sole factor predictive of retinal detachment after a single procedure (relative odds = 2.20, P = .02). Final reattachment rate, after reoperations, was 98% (49 of 50 eyes) in each group. Except for nonphakic eyes, final visual outcome and rate of postoperative proliferative vitreoretinopathy development did not differ significantly between the two procedures. CONCLUSIONS: In phakic eyes, pneumatic retinopexy was associated with a significantly higher reoperation rate than scleral buckling, but resulted in equivalent final visual outcome and reattachment rate after reoperations. If used, it must be incorporated into a strategy in which patient and physician are prepared for a greater chance of reoperation compared to initial management with scleral buckling. 相似文献
944.
945.
MI Riedmayr AR Tammen TM Behr C Wittig M Bullinger B Reichart CE Angermann 《Canadian Metallurgical Quarterly》1998,87(10):808-816
This prospective study was designed to compare quality of life, life satisfaction, and subjective ratings of health before and at variable time intervals after heart transplantation (HTx). 175 patients were included between February 1994 and December 1997. Every six months before and 1 1/2, 3, 6, and 12 months after HTx, they received the following standardized and validated questionnaires: German SF 36, heart failure and specific transplant symptom list, global quality of life assessment, Munich life quality dimension list, expected/experienced life changes after HTx. Inclusion criteria were the acceptance of the patient on the waiting list for HTx, good command of the German language, and a minimum age of 18 years. During data evaluation, median (Me), mean (M), and standard deviation (SD) were created from individual parameters. Quality of life was rated as very poor by 84% of patients with congestive heart failure. Only 6 weeks after HTx, 74% rated their quality of life as significantly better. Before HTx 80% were very unsatisfied about their health status and 87% about physical performance. Six weeks after HTx, this parameter improved significantly and 76% were very satisfied about their health status and 50% about physical performance. While somatic changes expected before HTx corresponded well with experienced ones, psychological improvements were smaller than expected, but one year after HTx they were significant (before: M = 3.66; SD = 0.9; Range (R) = 3.78 vs 12 months postop: M = 4.61; SD = 0.6; R = 2.67; p < 0.05). Quality of life correlated before HTx best with subjectively rated health (r = 0.61, p < 0.01) and 6 months after with satisfaction about health status (r = 0.76, p < 0.01). Only in 25% were expected improvements fulfilled regarding sexual activity/satisfaction, professional situation, and recreational activities. 90% of post-transplant patients reported physical complaints, most by effects of immunsuppression, but were coping well. The study shows that already 6 weeks after successful HTx all quality of life parameters improved significantly. Despite some unfulfilled expectations and complaints, the postoperative life situation of HTx patients appeared significantly improved. 相似文献
946.
947.
IH Ferreira A Bridier CE de Almeida D Marre J Chavaudra 《Canadian Metallurgical Quarterly》1998,43(10):2721-2727
The use of an ionization chamber for absorbed dose determinations in a medium requires one to take into account perturbation corrections due to the presence of the chamber cavity in the medium. Evaluation of these corrections for perturbation and their variation with depth in the medium has been performed for a flat cylindrical and a cylindrical (thimble-type) ionization chamber placed in a graphite phantom irradiated by a 60Co gamma beam using Monte Carlo calculations (EGS4 system with correlated sampling variance reduction technique). The results of these calculations agree with published experimental and theoretical data to better than 0.18%, with a statistical uncertainty of less than 0.17%. 相似文献
948.
949.
DC De Vivo TP Bohan DL Coulter FE Dreifuss RS Greenwood DR Nordli WD Shields CE Stafstrom I Tein 《Canadian Metallurgical Quarterly》1998,39(11):1216-1225
In November 1996, a panel of pediatric neurologists met to update the consensus statement issued in 1989 by a panel of neurologists and metabolic experts on L-carnitine supplementation in childhood epilepsy. The panelists agreed that intravenous L-carnitine supplementation is clearly indicated for valproate (VPA)-induced hepatotoxicity, overdose, and other acute metabolic crises associated with carnitine deficiency. Oral supplementation is clearly indicated for the primary plasmalemmal carnitine transporter defect. The panelists concurred that oral L-carnitine supplementation is strongly suggested for the following groups as well: patients with certain secondary carnitine-deficiency syndromes, symptomatic VPA-associated hyperammonemia, multiple risk factors for VPA hepatotoxicity, or renal-associated syndromes; infants and young children taking VPA; patients with epilepsy using the ketogenic diet who have hypocarnitinemia; patients receiving dialysis; and premature infants who are receiving total parenteral nutrition. The panel recommended an oral L-carnitine dosage of 100 mg/kg/day, up to a maximum of 2 g/day. Intravenous supplementation for medical emergency situations usually exceeds this recommended dosage. 相似文献
950.
BACKGROUND: Compromised splanchnic perfusion and the resulting intestinal mucosal injury leads to a decreased mucosal barrier function, which allows translocation of intestinal flora and endotoxemia. The authors evaluated the effects of milrinone on splanchnic oxygenation, systemic inflammation, and the subsequent acute-phase response in patients undergoing coronary artery bypass grafting. METHODS: This open, placebo-controlled randomized clinical study enrolled 22 adult patients in two groups. Before induction of anesthesia, baseline values were obtained and patients were randomized to receive milrinone (30 microg/kg bolus administered progressively in 10 min, followed by a continuous infusion of 0.5 microg x kg(-1) x min(-1)) or saline. The following parameters were determined: hemodynamics; systemic oxygen delivery and uptake; arterial, mixed venous and hepatic venous oxygen saturation; intramucosal pH (pHi); and mixed and hepatic venous plasma concentrations of endotoxin, interleukin 6, serum amyloid A, and C-reactive protein. RESULTS: Milrinone did not prevent gastrointestinal acidosis as measured by pHi, but its perioperative administration resulted in significantly higher pHi levels compared with control. Venous and hepatic venous endotoxin and the interleukin 6 concentration were reduced significantly in the milrinone group. Serum amyloid A values were attenuated in the milrinone group 24 h after surgery. No significant differences could be seen in routinely measured oxygen transport-derived variables. CONCLUSIONS: Perioperative administration of low-dose milrinone may have antiinflammatory properties and may improve splanchnic perfusion in otherwise healthy patients undergoing routine coronary artery bypass grafting. 相似文献