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991.
OBJECTIVE: To measure the beta-carotene concentration in buccal mucosal cells in smoking men who had received long-term beta-carotene (BC) supplementation in a controlled trial. To assess the association of cellular BC on the prevalence of dysplasia in oral leukoplakia. DESIGN: An end-of-trial examination of a part of subjects in the Alpha-Tocopherol, Beta Carotene Cancer Prevention Study. SUBJECTS AND METHODS: 343 men who for 5-7 years had received BC (20 mg/d) or alpha-tocopherol (AT) (50 mg/d), or both of these or placebo. BC concentration of buccal mucosal cells was compared in the subjects with BC supplementation (n = 173) to that of those without it (n = 170). Oral mucosae were examined clinically and lesions showing leukoplakia histopathologically. RESULTS: Mean (s.d.) BC concentration in buccal mucosal cells was 7.7 (10.3)mg/kg protein in the subjects who received BC compared to 1.1 (1.7) mg/kg protein in those who did not. The BC concentration in the cells of supplemented subjects correlated with their serum BC levels (P < 0.001). AT supplementation had no effect on BC concentration nor was daily amount of smoking statistically significantly associated with the BC concentration in buccal cells. Altogether 17 subjects showed oral leukoplakia, 7 had dysplasia. In these 7 subjects, the BC concentration in buccal mucosal cells did not differ statistically significantly compared to subjects with only hyperkeratosis (n = 10) (F-test, P = 0.74). CONCLUSIONS: After long-term BC supplementation, BC concentration in oral mucosal cells was 7-fold greater than without supplementation. There was no evidence to support an association between cellular BC concentration and precancerous lesions among the few subjects having them in their oral mucosae.  相似文献   
992.
OBJECTIVE: To test the simultaneous effect of various established predictors of breast and cervical cancer screening (breast self-examination, clinical breast examination by a physician, Papanicolaou [Pap] smear, and pelvic examination) in a low-income, Mexican-American sample. MATERIAL AND METHODS: A total of 188 Mexican-American women participated in a face-to-face structured interview in their preferred language. We tested a model with four established predictors of breast and cervical cancer screening--communication skills, knowledge of cancer, access to health care (finances and availability of care), and anxiety about cancer. Simultaneous structural equations analysis was used to form latent variables and to control for the effect of all predictors concurrently. RESULTS: Screening behavior was inversely associated with anxiety about cancer when all other predictors were statistically controlled. In addition, anxiety substantially affected the relationship between communication skills and screening behavior. Unexpectedly, knowledge of cancer was positively, rather than negatively, associated with anxiety about cancer. Predictors in the model demonstrated an excellent fit of the proposed model to the data. CONCLUSION: Successful cancer screening programs for Mexican-American women must address not only access barriers but also communication skills, knowledge, and, perhaps most importantly, anxiety.  相似文献   
993.
Bronchoconstriction in bronchial asthma and chronic obstructive pulmonary disease (COPD) may be due to decreased airway calibre and/or to the inability of the airways to distend after a deep inhalation (DI). The purpose of this review is to discuss the physiological and clinical relevance of this latter mechanism. During induced constriction, DI shows remarkable bronchodilatation in normal subjects, but a blunted or null effect in asthmatics. In contrast, during spontaneous bronchospasm DI tends to decrease airway calibre. From a functional point of view, airway inflammation, remodelling, and peripheral bronchoconstriction could prevent airway smooth muscle from stretching. Therapeutic intervention improving lung function may change the response to DI. For example, bronchodilators allow expiratory airflow before DI to increase more than after DI, because of decreased bronchial hysteresis. This suggest that bronchodilation might be systematically underestimated from parameters derived from maximal expiratory manoeuvres. Inhaled corticosteroids tend to increase the dilator effect of DI, likely due to decreased bronchial and peribronchial oedema. In conclusion, measuring the effects of deep inhalation on lung function is an easy and simple test able to evaluate the structural changes occurring in the airways and to monitor the effectiveness of therapy.  相似文献   
994.
BACKGROUND: Only 15 to 20 percent of patients with chronic hepatitis C have a sustained virologic response to interferon therapy. We compared the efficacy and safety of recombinant interferon alfa-2b alone with those of a combination of interferon alfa-2b and ribavirin for the initial treatment of patients with chronic hepatitis C. METHODS: We randomly assigned 912 patients with chronic hepatitis C to receive standard-dose interferon alfa-2b alone or in combination with ribavirin (1000 or 1200 mg orally per day, depending on body weight) for 24 or 48 weeks. Efficacy was assessed by measurements of serum hepatitis C virus (HCV) RNA and serum aminotransferases and by liver biopsy. RESULTS: The rate of sustained virologic response (defined as an undetectable serum HCV RNA level 24 weeks after treatment was completed) was higher among patients who received combination therapy for either 24 weeks (70 of 228 patients, 31 percent) or 48 weeks (87 of 228 patients, 38 percent) than among patients who received interferon alone for either 24 weeks (13 of 231 patients, 6 percent) or 48 weeks (29 of 225 patients, 13 percent) (P<0.001 for the comparison of interferon alone with both 24 weeks and 48 weeks of combination treatment). Among patients with HCV genotype 1 infection, the best response occurred in those who were treated for 48 weeks with interferon and ribavirin. Histologic improvement was more common in patients who were treated with combination therapy for either 24 weeks (57 percent) or 48 weeks (61 percent) than in those who were treated with interferon alone for either 24 weeks (44 percent) or 48 weeks (41 percent). The drug doses had to be reduced and treatment discontinued more often in patients who were treated with combination therapy. CONCLUSIONS: In patients with chronic hepatitis C, initial therapy with interferon and ribavirin was more effective than treatment with interferon alone.  相似文献   
995.
A prominent innervation of the pineal gland of the European hamster with nerve fibres containing neuropeptide Y (NPY) and tyrosine hydroxylase (TH) was demonstrated by means of immunohistochemistry. Nearly all the TH- and NPY-immunoreactive nerve fibres in the superficial pineal gland disappeared after bilateral superior cervical ganglionectomy, showing that the majority of NPY- and TH-immunoreactive nerve fibres belonged to the sympathetic nervous system. Since, in the European hamster, preliminary studies of the NPY-fibre density in the pineal gland had indicated seasonal changes, the density of NPY-immunoreactive nerve fibre profiles was ascertained in the superficial pineal gland in a series of animals between the first part of November and late April. The highest density of NPY-immunoreactive nerve fibre profiles was observed during midwinter. On the other hand, during the same period of the year, the number of sympathetic TH-immunoreactive sympathetic nerve fibre profiles did not exhibit seasonal variation, nor did substitution of testosterone, during the sexually inactive period, affect the density of NPY-containing nerve fibres in the gland. Our results show the presence of a testosterone-independent annual variation in the content of NPY in the sympathetic nerve fibres innervating the pineal gland of the European hamster. This variation can be correlated with the changes in the daily pattern of melatonin production observed by others in the same species at this period of the year.  相似文献   
996.
THIS RANDOMIZED, CONTROLLED, CLINICAL STUDY was designed to evaluate outcome following surgical implantation of an allogeneic, freeze-dried, demineralized bone matrix-calcium sulfate (DBM+CS) composite with a CS barrier in intrabony periodontal defects. Twenty-six patients contributing 26 deep intrabony defects completed the study. Thirteen patients received the DBM+CS implant. Thirteen patients received gingival flap surgery alone (GFS; control). Clinical outcome was assessed at 6 and 12 months postsurgery. At 12 months postsurgery, probing depth (PD) reduction (mean +/-SD) for the DBM+CS and GFS group was to 4.3+/-0.5 and 3.0+/-1.3 mm; clinical attachment gain was to 2.9+/-0.8 and 1.7+/-1.5 mm; and probing bone level gain was to 2.9+/-1.4 and 1.2+/-1.2 mm, respectively. There were no apparent differences between evaluations at 6 and 12 months postsurgery. Clinical improvements were significantly different from presurgery for both groups at both observation intervals (P < 0.01). There were no significant differences between groups in PD reduction and clinical attachment gain. Probing bone level gain was significantly greater in the DBM+CS group compared to controls (P < 0.05). In summary, surgical implantation of DBM+CS with a CS barrier resulted in reduced PD and improved attachment levels comparable to that achieved by gingival flap surgery alone. However, gain in probing bone levels in deep intrabony periodontal pockets assessed by clinical parameters was greater than that observed by gingival flap surgery alone. These changes were noted at both 6 and 12 months after surgery. This regenerative technique needs further biologic evaluation before being generally accepted.  相似文献   
997.
PURPOSE: We investigated whether control of constitutive endothelial cell nitric oxide synthase (cNOS) and nitric oxide (NO) by changes in shear stress might be important for the regulation of smooth muscle cell (SMC) growth and vascular diameter. METHODS: Bilateral femoral arteriovenous fistulas were placed in baboons to increase the blood flow in the external iliac arteries. At 2 months, the fistula was ligated on one side to restore normal flow (flow switch). RESULTS: In response to flow switch and a decrease in shear stress, iliac artery lumenal area decreased and SMC proliferation was induced. A decline in NO production, cNOS messenger RNA (mRNA), and protein were associated with these biological effects. In a subset of animals with iliac arteries under high flow, infusion of N(omega)-nitro-L-arginine, an inhibitor of cNOS, did not induce proliferation. CONCLUSION: Shear stress can regulate cNOS, vasoconstriction, and SMC proliferation. A decrease in nitric oxide may be necessary, but is not sufficient to induce SMC proliferation in response to a decrease in blood flow.  相似文献   
998.
BACKGROUND: Air leaks (ALs) are a common complication after pulmonary resection, yet there is no consensus on their management. METHODS: An algorithm for the management of chest tubes (CT) and ALs was applied prospectively to 101 consecutive patients who underwent elective pulmonary resection. Air leaks were graded daily as forced expiratory only, expiratory only, inspiratory only, or continuous. All CTs were kept on 20 cm of suction until postoperative day 2 and were then converted to water seal. On postoperative day 3, if both a pneumothorax and AL were present, the CT was placed to 10 cm H2O of suction. If a pneumothorax was present without an AL, the CT was returned to 20 cm H2O of suction. Air leaks that persisted after postoperative day 7 were treated with talc slurry. RESULTS: There were 101 patients (67 men); on postoperative day 1, 26 had ALs and all were expiratory only. Univariable analysis showed a low ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) (p = 0.005), increased age (p = 0.007), increased ratio of residual volume to total lung capacity (RV/TLC) (p = 0.04), increased RV (p = 0.02), and an increased functional residual capacity (FRC) (p = 0.02) to predict the presence of an AL on postoperative day 1. By postoperative day 2, 22 patients had expiratory ALs. After 12 hours of water seal, 13 of the 22 patients' ALs had stopped, and 3 more sealed by the morning of postoperative day 3. However, 2 of the 6 patients whose ALs continued experienced a pneumothorax. Five of the 6 patients with ALs on postoperative day 4 still had ALs on postoperative day 7, and all were treated by talc slurry through the CT. All ALs resolved within 24 hours after talc slurry. CONCLUSIONS: Most ALs after pulmonary resection are expiratory only. A low FEV1/FVC ratio, increased age, increased RV/TLC ratio, increased RV, and an increased FRC were predictors of having an ALs on postoperative day 1. Conversion from suction to water seal is an effective way of sealing expiratory AL, and pneumothorax is rare. If an expiratory AL does not stop by postoperative day 4 it will probably persist until postoperative day 7, and talc slurry may be an effective treatment.  相似文献   
999.
The antinociceptive effects of ABT-594, a novel nicotinic acetylcholine receptor (nAChR) ligand, were examined in rats in models of acute thermal (hot box) and persistent chemical (formalin test) pain. Also, the effects of ABT-594 treatment on motor function and electroencephalogram (EEG) were determined. In the hot box and formalin test (i.e., phase 1 and 2), acute treatment with ABT-594 (0.03, 0.1 and 0.3 mumol/kg i.p.) produced significant dose-dependent antinociceptive effects. In the hot box, the efficacy of ABT-594 was maintained after a repeated dosing paradigm (5 days b.i.d.i.p.). ABT-594 was fully efficacious in the formalin test when administered before formalin, and also retained significant efficacy (0.3 mumol/kg i.p.) when administered after formalin injection. The antinociceptive effects of ABT-594 in the hot box and formalin tests were attenuated by pretreatment with the nAChR antagonist, mecamylamine, and in animals treated with the nAChR antagonist chlorisondamine, given centrally (10 micrograms/rat i.c.v. 5 days before), but not in animals pretreated with the opioid receptor antagonist, naltrexone. Acute treatment with ABT-594 produced an initial decrease in open-field locomotor activity, which was absent in animals dosed repeatedly (5 days b.i.d.) with ABT-594. Also, acute treatment with ABT-594 decreased body temperature and decreased the amount of time the animals could maintain balance in an edge-balance test. These effects were no longer present in animals dosed repeatedly with ABT-594. At antinociceptive doses, ABT-594 produced activation of free running EEG in contrast to the sedative-like effects of morphine. Full antinociceptive efficacy was maintained in both the hot box and formalin tests after oral administration, whereas the effects on motoric performance were attenuated. In conclusion, these data demonstrate that ABT-594 is a potent antinociceptive agent with full efficacy in models of acute and persistent pain and that these effects are mediated predominately by an action at central neuronal nAChRs. In addition, antinociceptive effects were maintained after repeated dosing, whereas effects of ABT-594 on motor and temperature measures were attenuated in animals treated repeatedly with ABT-594. Thus, compounds acting at nAChRs may represent a novel approach for the treatment of a variety of pain states.  相似文献   
1000.
This study was designed to examine the classification performance of diagnostic rules for pervasive developmental disorder not otherwise specified (PDD-NOS) and multiple complex developmental disorder (McDD), with clinical diagnosis as the gold standard. McDD is an heuristic concept of a developmental disorder characterised by social impairments, affective dysregulation, and thought disturbance. Detailed information on the symptoms, reliably extracted from the charts of 103 children with PDD-NOS and McDD, 32 with autistic disorder, and 96 with non-PDD disorders, was used to determine the presence of the DSM-IV criteria of autistic disorder and the criteria of McDD. A scoring rule for PDD-NOS based on a short set of seven DSM-IV criteria with a cut-off point of three items and one social interaction item set as mandatory had the best balance between high sensitivity and high specificity. The most effective and simple rule based on McDD criteria had a cut-off of three items, out of six items of anxieties and thought disturbance.  相似文献   
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