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21.
The present study was undertaken to evaluate the postoperative relapse from the period of unwiring to 1 year postoperatively and its correlation to the amount of mandibular setback and change in vertical dimension after mandibular bilateral sagittal split osteotomy. Twenty-seven patients were evaluated cephalometrically by the time preoperatively, 6 weeks, 6 months and 1 year postoperatively. It was found that 1) the average amount of mandibular setback at pogonion point, 6 weeks postoperatively, is 7.6mm backward and 1.9mm downward, 2) the average amount of horizontal relapse at pogonion point, 6 months and 1 year postoperatively, are 1.9mm and 2.3mm respectively. 86% of the horizontal relapse, 1 year postoperatively, occurs in the first 6 months after removal of intermaxillary fixation, 3) the average amount of vertical relapse at pogonion point, 6 months and 1 year postoperatively, are 0.9mm and 1.1mm upward. 82% of the vertical relapse, 1 year postoperatively, occurs in the first 6 months after removal of intermaxillary fixation, 4) the amount of 1 year postoperatively horizontal relapse is significantly correlated both with the amount of horizontal mandibular set back and vertical downward change (r = 0.58, 0.67, p < 0.001), whereas the amount of vertical relapse is with the vertical downward change only, but horizontal setback isn't.  相似文献   
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1. We investigated the effect of exercise on plasma adrenomedullin, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations and studied the relationship between these peptides and haemodynamic parameters in nine patients with old myocardial infarction (MI) and in eight normal subjects. 2. The exercise protocol consisted of two fixed work loads (40 and 80 W) for 4 min each and venous blood samples were taken at rest, during each exercise stage and after exercise while monitoring the mean arterial pressure (MAP) and heart rate (HR). In MI, pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP) and cardiac output (CO) were measured throughout exercise. 3. Adrenomedullin levels did not significantly increase with exercise. Adrenomedullin levels correlated with PAP and PCWP at rest (P < 0.05). Atrial natriuretic peptide levels correlated with PAP, PCWP and LVEDP throughout exercise (P < 0.05) but, on multiple regression analysis, PCWP correlated only with ANP (P < 0.01). Brain natriuretic peptide levels correlated with LVEDP throughout exercise (P < 0.01) and its increment correlated closely with basal BNP levels at rest (P < 0.01). 4. These results suggest that adrenomedullin does not respond to the acute haemodynamic changes of exercise, whereas ANP responds to it and PCWP is the major stimulus factor. Brain natriuretic peptide responds to exercise in proportion to the basal synthesis of BNP in patients with left ventricular dysfunction and LVEDP may play a role in increasing BNP during exercise.  相似文献   
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The influence of the nicotine antagonist dihydro-beta-erythroidine (DH beta E) was examined on various behavioural effects of nicotine in rats. Motor activity was recorded in photocell cages whereas discriminative stimulus effects were examined using two-lever drug discrimination procedures with a tandem schedule of food reinforcement (n = 8 throughout). DH beta E (0.1-3.2 mg/kg) failed to antagonise the decreases in motor activity that nicotine (0.4-0.6 mg/kg) produced in experimentally naive rats, whereas mecamylamine (1.5 mg/kg) completely blocked this effect of nicotine. DH beta E (0.1-3.2 mg/kg) antagonised the increases in motor activity that nicotine (0.4 mg/kg) produced in rats with extensive previous exposure to both nicotine and the photocell apparatus. In rats trained to discriminate either 0.1 or 0.4 mg/kg nicotine from saline, DH beta E (0.1-3.2 mg/kg) blocked the discriminative stimulus effect of nicotine. The block of the discriminative effect could be reversed by increasing the dose of nicotine; DH beta E (1.6 mg/kg) shifted the dose-response curve for nicotine discrimination to the right by a factor of 9.4. In addition, nicotine in doses of 0.32-0.64 mg/kg decreased the overall rate of lever pressing but DH beta E (1.6 mg/kg) did not influence the dose-response curve for this effect. Thus, DH beta E potently blocked the locomotor activating and discriminative stimulus effects of nicotine at doses that did not antagonise its locomotor depressant and operant response rate-reducing effects. This selective blockade supports the involvement of different subtypes of nicotinic receptor in the mediation of diverse behavioural effects. Furthermore, the rightward shift of the dose-response curve for nicotine discrimination suggested a competitive mode of action for DH beta E.  相似文献   
24.
The complete set of measurements that could ever be used by a passive 3D vision algorithm is the plenoptic function or light-field. We give a concise characterization of when the light-field of a Lambertian scene uniquely determines its shape and, conversely, when the shape is inherently ambiguous. In particular, we show that stereo computed from the light-field is ambiguous if and only if the scene is radiating light of a constant intensity (and color, etc.) over an extended region.  相似文献   
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Forty-three patients with spastic quadriplegia (mean age 7.9 years, range 3.3 to 17.2 years) underwent bone mineral density (BMD) measurement of the lumbar spine and were evaluated between 2.6 and 5.5 years (mean 3.8) later to determine whether this measurement had predicted risk of fracture over the subsequent period of observation. Other potential risk factors that were evaluated include body weight z score, serum vitamin D levels, previous fracture, and hip spica casting. The baseline measurements showed that BMD falls further below normal with increasing age and was more than one standard deviation below age-matched normal mean in 38 of the 43 patients. Fracture rate did not differ between those with low and those with very low spinal BMD. Similarly, serum vitamin D levels and body weight z scores were not predictive of fracture. However, fracture rate was over fourfold greater following spica casting and more than threefold greater following an initial fracture. Fracture rates in the study group were similar to those reported for age- and sex-matched normal children, though generally the location of the fractures and mechanisms of injury differed.  相似文献   
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The effects of lipid peroxidation and the antioxidant vitamin E contained in LDL isolated from control plasma (LDL--) and from plasma preincubated with 0.5 mmol/ml alpha-tocopherol (LDL+) on the proliferation of estrogen-receptor positive (ER+ : ZR-75, T-47-D, MCF-7) and negative (ER--: HBL-100, MDA-MB-231) human breast cancer cells were studied. Human skin fibroblasts served as controls. Incubation of plasma with 0.5 mmol/ml alpha-tocopherol resulted in a 3-fold increase of its content and a significant reduction in lipid hydroperoxides and conjugated dienes in LDL. Incubation of fibroblasts or ER+ tumor cells with LDL- or LDL+ had an effect on neither cell proliferation nor on the cellular levels of peroxidation products as compared to control incubations in the absence of LDL. In ER- cells, however, LDL+ stimulated the proliferation, whereas LDL- yielded a cytotoxic effect. Moreover, LDL- supplementation resulted in an increase in the content of hydroperoxides and conjugated dienes. LDL+ supplemented cells exhibited hydroperoxide levels in these tumor cells comparable to the basal levels measured in the absence of LDL. Our data suggested that peroxidation products in LDL are cytotoxic to estrogen-receptor negative breast tumor cells and vitamin E counteracts this effect.  相似文献   
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