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91.
To determine level of alcohol use/misuse and to examine correlates of these behaviors, 1,314 fourth-grade students were surveyed. The questionnaire included 55 items concerning tolerance of deviance, deviant self-image, self-efficacy, susceptibility to peer pressure, personal and peer approval of alcohol use, peer adjustment, parent nurturance and monitoring, family adjustment, parental permissiveness, peer use of alcohol, and exposure to alcohol. The items were factor analyzed and indices constructed. The indices generally had acceptable alpha coefficients (alpha = .61-.91); two exceptions were peer adjustment (alpha = .51) and parental permissiveness (alpha = .42). Tolerance of deviance, deviant self-image, susceptibility to peer pressure, personal and peer approval, peer use and exposure by peers, and parental permissiveness were positively correlated with alcohol use/misuse. Self-efficacy, child-parent interactions, family adjustment, and peer adjustment were negatively correlated with alcohol use/misuse. Implications for the design of family-based alcohol use/misuse prevention programs are discussed.  相似文献   
92.
In December 1991, an outbreak of Streptococcus bovis septicaemia occurred in a Belgian pigeon loft where 25 male and 25 female racing pigeons were housed. The main clinical signs included inability to fly and poor breeding results. None of the female pigeons and only one male pigeon was able to fly. Nine affected pigeons were necropsied. Histologically a tenosynovitis of the tendon of the deep pectoral muscle was observed in most of them and S bovis was isolated from the canalis triosseus or the shoulder joints of five of the nine pigeons. The pigeons were successfully treated with ampicillin administered in the drinking water for seven days.  相似文献   
93.
In-situ synchrotron radiation has been used to provide direct analysis of the transformation sequences in TiNi-based shape memory alloys during thermal cycling. The high resolution, narrow peak width Debye–Scherrer diffraction spectra enabled positive identification and quantification of the phase transformation sequences, which is not possible through normal laboratory studies. The results facilitate a clearer understanding of the development and influence of intermediate phases such as R or B19 on sequential martensitic transformations. Ti50.2Ni49.8 transformed predominately via a single-step B2 ↔ B19′ transformation, although evidence of the R phase was found during cooling in every cycle. The martensitic start temperature was depressed by ~0.6 °C per cycle, while the R-phase start temperature was found to be unaffected. Ti50Ni41Cu9 transformed through a two-step B2 ↔ B19 ↔ B19′ sequence, with the B2 → B19 transformation reaching completion prior to the formation of any B19′. The transformation temperatures of Ti50Ni41Cu9 were found to be insensitive to thermal cycling, remaining constant over the studied cycle range.  相似文献   
94.
95.
BACKGROUND: Biphasic waveforms have had a favorable impact on internal defibrillation but have seen minimal use in transthoracic defibrillation systems. The purpose of this study was to compare monophasic and biphasic waveforms for transthoracic defibrillation in swine. METHODS AND RESULTS: Three interrelated studies were performed in 19 swine to establish the relative transthoracic defibrillation efficacy of biphasic shock waveforms. In study 1, we measured voltage (V50) and energy (E50) strength-duration curves for monophasic and biphasic truncated exponential waveforms. We then independently examined the effects of phase duration and tilt on biphasic waveform defibrillation with a total waveform duration from study 1 that provided the minimum V50 (study 2) and the minimum E50 (study 3). At each pulse duration tested in study 1, biphasic waveforms defibrillated with significantly less voltage and energy than monophasic waveforms. At a duration of 12 ms, there was a voltage minimum for biphasic waveform defibrillation. At this duration, V50 was 1378 +/- 505 V for the biphasic waveform compared with 2185 +/- 361 V for the monophasic waveform, P = .01. For both monophasic and biphasic waveforms, E50 increased with pulse duration. With a total pulse duration of 12 ms, E50 was 169 +/- 101 J for the biphasic waveform compared with 414 +/- 114 J for the monophasic waveform, P = .003. In study 2, optimization of phase duration and total tilt reduced the defibrillation requirements of the 12-ms "minimum voltage" biphasic waveform to 1284 +/- 187 V and 129 +/- 36 J. In study 3, the 8-ms "minimum energy" biphasic waveform had an E50 of 115 +/- 35 J that was 11% less than the 12-ms biphasic waveform, P = .11; however, voltage requirements of 1476 +/- 239 V were 15% higher, P = .005. CONCLUSIONS: This study demonstrates the superiority of truncated biphasic waveforms over truncated monophasic waveforms for transthoracic defibrillation of swine. Biphasic waveforms should prove as advantageous at reducing voltage and energy requirements for transthoracic defibrillation as they have for internal defibrillation.  相似文献   
96.
Inflammatory action of the potent chemotaxin C5a has been well characterized on a variety of human cell types, including neutrophils, monocytes, basophils, and eosinophils. The cellular effects of C3a are less well defined. Contradictory reports have been published for C3a activation of neutrophils. Recent reports that C3a activates both basophils and eosinophils prompted us to reinvestigate the effects of C3a stimulation on eosinophils. We hypothesized that C3a activation of eosinophils, cells that are present in most neutrophil preparations, might lead to neutrophil activation. Using neutrophils of 98% purity, we observed no evidence of cellular activation after stimulation with either C3a, recombinant human C3a (rhC3a), or the synthetic C3a analogue C3a 57-77, Y57. Eosinophils purified to > 98% purity displayed concentration-dependent polarization, chemotaxis, and enzyme release by stimulation with C3a, rhC3a, and the synthetic C3a analogue. An inactive form of C3a, C3adesArg, failed to stimulate either eosinophils or neutrophils. Using neutrophil preparations containing 5-9% eosinophils, up to 20% of neutrophils became polarized after exposure to C3a. Likewise, we demonstrated that supernatant from C3a-stimulated eosinophils promotes neutrophil chemotaxis. Eosinophil polarization experiments were repeated in the presence of antibody to the C5a receptor (C5aR) to show that C3a and C5a interact with different receptors. C3a activates eosinophils in the presence of anti-C5aR antibody at concentrations that fully block C5a activation. We conclude that eosinophils are directly activated by either C3a or C5a, whereas C3a failed to activate neutrophils. C3a acts on eosinophils via a receptor that is distinct from C5aR. Since neutrophils are indirectly stimulated by C3a, eosinophils contaminating neutrophil preparations may explain earlier reports that C3a activates human neutrophils.  相似文献   
97.
Free radical-mediated esophagitis was studied during duodenogastroesophageal reflux (mixed reflux) or acid reflux in rats. The influence of reflux on esophageal glutathione levels was also examined. Mixed reflux caused more gross mucosal injury than acid reflux. Gross mucosal injury occurred in the mid-esophagus. Total glutathione (GSH) in the esophageal mucosa of control rats was highest in the distal esophagus. The time course of esophageal GSH in rats treated by mixed reflux showed a significant decrease 4 hr after initiation of reflux, followed by a significant increase from the 12th hour on. Mucosal GSH was increased in both reflux groups after 24 hr but significantly more so in the mixed than in the acid reflux group. The free radical scavenger superoxide dismutase (SOD) prevented esophagitis and was associated with decreased GSH levels. GSH depletion by buthionine sulfoximine (BSO) prevented esophagitis and stimulated SOD production in the esophageal mucosa. It is concluded that gastroesophageal reflux is associated with oxidative stress in the esophageal mucosa. The lower GSH levels in the mid-esophagus may predispose to damage in this area. Duodenogastroesophageal reflux causes more damage than pure acid reflux. Oxidative stress leads to GSH depletion of the esophageal mucosa in the first few hours following damage but then stimulates GSH production. GSH depletion by BSO does not worsen esophagitis since it increases the esophageal SOD concentration.  相似文献   
98.
We investigated the effect of the adenosine receptor agonist 5'-(N-ethylcarboxamido)adenosine (NECA) in catecholamine secretion from adrenal chromaffin cells that exhibit only the A2b subtype adenosine receptor. NECA reduced catecholamine release evoked by the nicotinic agonist 1,1-dimethyl-4-phenylpiperazinium (DMPP) in a time-dependent manner. Inhibition reached 25% after 30-40-min exposure to NECA. This effect on DMPP-evoked catecholamine secretion was mirrored by a similar (27.7 +/- 3.3%), slowly developing inhibition of [Ca2+]i transients induced by DMPP that peaked at 30-min preincubation with NECA. The capacity of the chromaffin cells to buffer Ca2+ load was not affected by the treatment with NECA. Short-term treatment with NECA failed both to modify [Ca2+]i levels and to increase endogenous diacylglycerol production, showing that NECA does not activate the intracellular Ca2+/protein kinase C signaling pathway. The inhibitory effects of NECA were accompanied by a 30% increase of protein phosphatase activity in chromaffin cell cytosol. We suggest that dephosphorylation of a protein involved in DMPP-evoked Ca2+ influx pathway (e.g., L-type Ca2+ channels) could be the mechanism of the inhibitory action of adenosine receptor stimulation on catecholamine secretion from adrenal chromaffin cells.  相似文献   
99.
Nonobese diabetic (NOD) mice spontaneously develop insulin dependent diabetes mellitus. The disease results from an autoimmune process which involves mononuclear cells surrounding and eventually infiltrating the pancreatic islets of Langerhans. Macrophages are thought to be the first cells to infiltrate the islets and are actively involved in the disease process because diabetes is prevented if host macrophages are depleted or inactivated. Several lines of evidence also suggest that NOD macrophages are phenotypically and functionally abnormal. In this study, allogeneic (CBA) macrophages derived from the thymus were inoculated into newborn NOD mice and these were followed for more than 250 days. Spontaneous diabetes was significantly reduced in female NOD mice (6% diabetic versus 45% of controls). Insulitis was also significantly reduced in both male and female mice compared to their control counterparts, and in most cases there were virtually no inflammatory cells in the pancreas. Allogeneic skin grafting and mixed leukocyte cultures indicated that the recipients were not tolerant of donor antigens, and donor-derived cells were not detected in the lymphoid tissues by either flow cytometry or immunohistochemistry. The results show that macrophages from diabetes-resistant donors will prevent insulitis and diabetes in most recipients, however, the mechanism for the protection is unclear, but does not appear to be due to long-term tolerance induction.  相似文献   
100.
To investigate the outcome of Graves' thyrotoxicosis after antithyroid drug management, data from 81 patients, treated in Chang Gung Memorial Hospital at Taipei and Linkou from October 1981 to March 1990, were analyzed. The gender ratio of female to male was 59:22. The mean age of onset was 33.1 +/- 10.5(15-60) year-old. All the patients were treated with antithyroid drug (Thionamide group) for a duration of 11 to 63 months (mean +/- SD = 28.1 +/- 9.8 months). Forty of 81 patients (49.4%) were remained remission after up to 2 years of follow-up. Those patients relapse usually occurred within 2 years after discontinuation of treatment (34/41), and only one exceptional case relapsed after 3 years. Three conditions affected the relapse rate. Patients with larger goiter (grade II-III) and shorter duration of treatment (< 23 months) had a higher relapse rate than those-with smaller goiter (grade O-I) [29/46 vs. 12/35; chi 2 = 6.576, p = 0.010; p = 0.015 in stepwise logistic regression (LR)] and longer duration of treatment (> or = 23 months) (15/20 vs. 26/61; chi 2 = 6.316, p = 0.012; p = 0.020 in LR). Patients with higher pre-treated serum triiodothyronine (T3) level (T3 > or = 300 ng/dl) had a higher relapse rate than those with lower T3 level (T3 < 300 ng/dl) in univariate analysis (30/50 vs. 11/31, chi 2 = 4.601, p = 0.032), but no significant difference by LR (P = 0.094). Other clinical parameters including age, sex, past history, family history, thyroxine (T4) level, T3/T4 ratio, thyroid autoantibodies, staging of ophthalmopathy, responsiveness to thyrotropin-releasing hormone stimulation test at the end of treatment, and whether combined treatment with thyroxine had no significant difference between the relapse and remission groups. These data suggest: (a) patients with larger goiter (grade II-III had higher relapse rate; (b) most of the recurrent thyrotoxicosis patients relapsed within two years after drug withdrawal; (c) continuing treatment for more than twenty-three months produces better outcome; (d) patients with Graves' thyrotoxicosis should be followed up for at least three years after withdrawal of antithyroid drug.  相似文献   
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