首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
A 56 year old patient with psychiatric complications of systemic lupus erythematosus developed severe dysphagia complicated by weight loss and aspiration. Following investigation it was concluded that the addition of haloperidol to her treatment was the major precipitating cause and withdrawal of the drug was followed by an objective improvement in swallowing. Patients taking major transquillizers may be at increased risk of severe dysphagia; regular observation of swallowing is suggested as a useful addition to the clinical examination of these patients.  相似文献   

3.
A hydrophobic, redox-active component with a molecular mass of 538 Da was isolated from lyophilized membranes of Methanosarcina mazei G?1 by extraction with isooctane. After purification on a high-performance liquid chromatography column, the chemical structure was analyzed by mass spectroscopy and nuclear magnetic resonance studies. The component was called methanophenazine and represents a 2-hydroxyphenazine derivative which is connected via an ether bridge to a polyisoprenoid side chain. Since methanophenazine was almost insoluble in aqueous buffers, water-soluble phenazine derivatives were tested for their ability to interact with membrane-bound enzymes involved in electron transport and energy conservation. The purified F42OH2 dehydrogenase from M. mazei G?1 showed highest activity with 2-hydroxyphenazine and 2-bromophenazine as electron acceptors when F420H2 was added. Phenazine-1-carboxylic acid and phenazine proved to be less effective. The Km values for 2-hydroxyphenazine and phenazine were 35 and 250 microM, respectively. 2-Hydroxyphenazine was also reduced by molecular hydrogen catalyzed by an F420-nonreactive hydrogenase which is present in washed membrane preparations. Furthermore, the membrane-bound heterodisulfide reductase was able to use reduced 2-hydroxyphenazine as an electron donor for the reduction of CoB-S-S-CoM. Considering all these results, it is reasonable to assume that methanophenazine plays an important role in vivo in membrane-bound electron transport of M. mazei G?1.  相似文献   

4.
Across the boreal forest of North America, lynx populations undergo 10-year cycles. Analysis of 21 time series from 1821 to the present demonstrates that these fluctuations are generated by nonlinear processes with regulatory delays. Trophic interactions between lynx and hares cause delayed density-dependent regulation of lynx population growth. The nonlinearity, in contrast, appears to arise from phase dependencies in hunting success by lynx through the cycle. Using a combined approach of empirical, statistical, and mathematical modeling, we highlight how shifts in trophic interactions between the lynx and the hare generate the nonlinear process primarily by shifting functional response curves during the increase and the decrease phases.  相似文献   

5.
6.
A number of authors have indicated in recent years that the course of depression is not as favourable as previously expected. Research conducted in order to identify predictors of recovery has shown widely different results. In this paper a sample of 90 consecutive patients with non-chronic major depressive disorders (index episode < 6 months) attending four mental health centres in Madrid were followed up prospectively for 6 months, and clinical social and cognitive variables were studied. The patients were treated pharmacologically and controlled. The rate of recovery was measured according to the Hamilton Rating Scale for Depression (HAM-D). Other tools used were: Life Events and Chronic Difficulties, Global Assessment Functioning in the 6 months prior to the onset of episode, Brown Rating Scale for Self-Esteem and Mannheim Interview of Social Support. The results showed that 41 cases recovered (HAM-D score < 8), 29 cases achieved a partial remission, and major depressive disorder persisted in 17 cases (HAM-D score > or = 18). The presence of personality disorders, having suffered a previous episode, GAF score and some aspects of social support were the variables most associated with non full remission in the logistic regression analysis. Personality disorders and the initial HAM-D score were related to non-improvement. Some clinical and cognitive variables maintain a weak relation to outcome and are rejected in logistic regression. This study emphasizes the relationship of personality, and social variables such as social support and previous global functioning, with incomplete recovery in major depression.  相似文献   

7.
Describes 3 models (the linear additive learning model, the exponential additive learning model, and the independent trace model) of sequential effects in psychophysical tasks. These models were tested using data from a study by W. S. Verplack et al (see record 1953-04864-001). The models appear to be most consistent with the independent trace model in which the momentary value of the criterion is modified by memory traces, an independent trace being retained for each relevant past event. On this basis, a theory of criterion setting is developed: A long-term process determines an initial value for the criterion, and 2 short-term processes adjust the criterion to match current changes in the expected probabilities of signals and to maximize the information transmitted by the S's responses. The theory is applied to results in the literature. (65 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
Consumers in the United States continue to eat raw or undercooked foods of animal origin despite public health warnings following several well-publicized outbreaks. We investigated an outbreak of Salmonella serotype Typhimurium infection in 158 patients in Wisconsin during the 1994 Christmas holiday period. To determine the vehicle and source of the outbreak, we conducted cohort and case-control studies, and environmental investigations in butcher shop A. Eating raw ground beef purchased from butcher shop A was the only item significantly associated with illness [cohort study: relative risk = 5.8, 95% confidence interval (CI) = 1.5-21.8; case control study: odds ratio = 46.2, 95% CI = 3.8-2751]. Inadequate cleaning and sanitization of the meat grinder in butcher shop A likely resulted in sustained contamination of ground beef during an 8-day interval. Consumer education, coupled with hazard reduction efforts at multiple stages in the food processing chain, will continue to play an important role in the control of foodborne illness.  相似文献   

9.
PURPOSE: Cataract surgery is often followed by a posterior capsule opacification, usually treated with YAG laser capsulotomy, however, there are huge variations in the incidence figures available in the literature, from 18 to 50% (Sterling & Wood 1986). We have therefore analyzed the incidence of secondary cataracts in a population-based cohort of patients, as revealed by the number of YAG laser capsulotomies performed postoperatively. METHODS: Data for all patients undergoing cataract surgery from 1986 up to and including 1990 in the Lund Health Care District were prospectively recorded, and 4722 patients were retrieved for analysis, using only one eye per patient. The patients had been operated on with extracapsular extraction (phacoemulsification or planned large incision procedure) or a combined trabeculectomy and cataract extraction procedure leaving an intact capsule after surgery. Death dates for each patient were obtained from the Swedish Bureau of Census up to and including 1991. Different risk factors were considered such as sex, age, preoperative axial length, preoperative average keratometry, preoperative intraocular pressure, glaucoma history, diabetes history, uveitis history (including both anterior and posterior uveitis), history of age related macular degeneration and a history of rheumatoid arthritis. We also considered the influence of factors connected to the operation itself on the incidence of secondary capsular haze: extraction mode (ordinary ECCE versus phacoemulsification or trabeculectomy) and the type of implant and the surgeon's surgical activity. RESULTS: Besides age, four variables significantly influenced the risk of having postoperative YAG laser treatment. They were gender, iris sphincterotomy, operation date, and whether the patient came from a rural or an urban region. After about four to five years, the percentage of patients not having had a YAG laser capsulotomy was reduced to around 50% for women and 60% for men. These percentages were based on a survival analysis, minimizing the confounding effect of the limited life span of these elderly patients. CONCLUSIONS: In this material, the most important predisposing factors for YAG laser capsulotomy after extracapsular cataract surgery are: young age, female gender, if the patient was operated late in the period observed, and if the patient came from an urban area.  相似文献   

10.
The prevalence of students with mathematics learning disabilities has triggered an interest among special education researchers and practitioners in developing an understanding of the needs of this group of students, and in identifying effective instructional programming to foster their mathematical performance during the school years and into adulthood. Research into the characteristics of students with mathematics learning disabilities is being approached from different perspectives, including developmental, neurological and neuropsychological, and educational. This diversity helps us develop a broader understanding of students' learning needs and difficulties. Special education assessment practices encompass a variety of approaches, including norm-referenced, criterion-referenced, and nonstandardized procedures, depending on the specific assessment questions professionals seek to answer. Students' mathematical knowledge and conceptual understanding must be examined to determine their strengths and weaknesses, curriculum-based progress, and use of cognitive strategies to arrive at mathematical solutions. Research findings have identified empirically validated interventions for teaching mathematics curricula to students with mathematics learning disabilities. Research studies have been grounded in behavioral theory and cognitive psychology, with an emergent interest in the constructivist approach. Although research studies have focused primarily on computational performance, more work is being conducted in the areas of story-problem solving and technology. These areas as well as other math curricular skills require further study. Additionally, the needs of adults with math LD have spurred educators to examine the elementary and secondary math curricula and determine ways to infuse them with life skills instruction accordingly. As the field of mathematics special education continues to evolve, special educators must remain cognizant of the developments in and influences on the field of mathematics education. Reform efforts have shaped the field significantly since the 1950s, contributing to the curriculum offered in mathematics textbooks and the pedagogical practices taught in higher education courses. Mathematics educators continue to search for a better understanding of how children learn mathematics; this process is shaped by the prevailing theoretical orientations and research methodologies. This special series in mathematics special education provides readers with information about the characteristics of students with mathematics learning disabilities, assessment procedures, mathematics programming, teacher preparation, and future directions for the field. The series originated as a result of discussions with Dr. Lee Wiederholt and Dr. Judith K. Voress, who saw a need for the compilation of recent research and best practices in mathematics special education. I thank them for their support of and thoughtful insights about the development of this series. I also appreciate the support of Dr. George Hynd and his editorial assistant, Kathryn Black, in finalizing the details for publication. Finally, I am most appreciative of the authors' contributions to this series; their work continues to significantly influence the development of the field of mathematics special education and programming for students with mathematics learning disabilities.  相似文献   

11.
12.
13.
PURPOSE: To quantify the risks of intrauterine antiepileptic drug (AED) exposure in monotherapy and polytherapy. METHODS: Data from five prospective European studies totaling 1,379 children were pooled and reanalyzed. Data were available for 1,221 children exposed to AED during pregnancy and for 158 children of unexposed control pregnancies. RESULTS: Overall, when comparing a subgroup of 192 children exposed to AED with 158 children of matched nonepileptic controls, there was an increased risk of major congenital malformations (MCA) in children exposed to AED during gestation [relative risk (RR) 2.3; 95% confidence interval (CI): 1.2-4.7]. A significant increase in risk was found for children exposed to valproate (VPA) (RR 4.9; 95% CI: 1.6-15.0) or carbamazepine (CBZ) (RR 4.9; 95% CI: 1.3-18.0) in monotherapy. When comparing different AED regimens during all 1,221 pregnancies, risks of MCA were significantly increased for the combination of phenobarbital (PB) and ethosuximide (RR 9.8; 95% CI: 1.4-67.3) and the combination of phenytoin, PB, CBZ, and VPA (RR 11.0; 95% CI: 2.1-57.6). Offspring of mothers using > 1,000 mg VPA/day were at a significantly increased risk of MCA, especially neural tube defects, compared to offspring exposed < or =600 mg VPA/day (RR 6.8; 95% CI: 1.4-32.7). No difference in risk of MCA was found between the offspring exposed to 601-1,000 mg/day and < or =600 mg/day. CONCLUSIONS: This reanalysis shows that VPA is consistently associated with an increased risk of MCA in babies born to mothers with epilepsy. Significant associations were also observed with CBZ. Larger prospective population-based studies are needed to evaluate the risks of many other less frequently prescribed treatment regimens, including newly marketed AEDs.  相似文献   

14.
Male alcoholic inpatients with a high incidence of memory blackouts did not differ on several memory measures from subjects with a low incidence of blackouts. Alcoholism chronicity also did not differentiate between subjects on the Wechsler Memory Scale, tests of storage and decay of a memory trace, and maintenance of a concept along a temporal continuum. A history of blackouts was, however, related to drinking pattern. High-incidence subjects reported a significantly greater frequency of drinking to intoxication or until falling asleep, craving a drink, and increased tolerance to alcohol.  相似文献   

15.
The sensitivity of the most recent generation of anti-hepatitis C virus (anti-HCV) screening tests from seven manufacturers was evaluated with a common panel of 530 specimens from 320 HCV-infected subjects. This panel included 221 samples from 57 seroconverters (53 pre-sero conversion negative specimens and 168 positive samples) and 309 selected specimens from 263 other HCV-infected patients of which 19% exhibited NS3 or core reactivity alone with the presence of HCV-RNA assessed by PCR. None of the seven screening tests detected all infectious and antibody-positive specimens. However, important differences were observed between these assays in the number of false-negative results, which seemed mainly due to nonreactivity of antibody to the NS3 antigen.  相似文献   

16.
Responses of cytotoxic T-cells (Tc) to human cytomegalovirus (CMV) represent the predominant mechanism by which hosts resist CMV infection. The CMV major immediate-early protein (IE) is present throughout the virus replicative cycle. Studies were performed to determine whether Tc specific for IE effectively lyse CMV-infected targets and are thus capable of providing protective immunity against infection. After in vitro stimulation of peripheral blood mononuclear cells with CMV-infected autologous fibroblasts, Tc specific for IE were not readily detectable in CMV-reactive polyclonal Tc lines. However, after stimulation of peripheral blood mononuclear cells with cells selectively expressing IE, weak but detectable IE-specific Tc responses were observed. The frequency of IE-specific Tc clones derived from cultures stimulated with IE-expressing cells was 50 to 100 times lower than the frequency of Tc clones specific for other CMV proteins isolated from cultures stimulated with CMV-infected cells. All of the IE-specific Tc clones, which efficiently lysed targets selectively expressing IE, demonstrated minimal lysis of CMV-infected fibroblasts, despite abundant IE expression in these target cells. In contrast to these results with IE, other viral proteins were efficiently presented during all phases of CMV infection. These data suggest that CMV has evolved a unique mechanism for selectively limiting the presentation of the potentially immunogenic IE protein, which may preclude IE-specific Tc from providing protective immunity to CMV infection.  相似文献   

17.
Smoking tobacco contributes to and exacerbates many chronic diseases of aging, including hypertension, stroke, COPD, heart disease, and atherosclerosis. It is also associated with an increased risk of peptic ulcers and of cancers of the lungs and oral cavity. Older patients generally continue to smoke because of physiologic and psychological addiction to nicotine. Nicotine administration through gum or patch eases the symptoms of nicotine withdrawal for highly-tolerant patients. Detecting and treating alcohol abuse, depression, or life stress may then make it easier to motivate the patient to quit smoking. Physician advice combined with follow-up visits and phone calls has been shown to be one of most effective methods of getting patients to stop smoking.  相似文献   

18.
The purpose of this study was to compare the value of dynamic magnetic resonance imaging (MRI) and fat suppression in detecting a pancreatic tumor. The subjects were 19 patients with invasive ductal adenocarcinoma and six patients with islet cell tumor where diagnosis was established pathologically. Breath-hold gradient echo images, breath-hold gradient echo images with fat suppression and breath-hold gradient echo images with dynamic enhancement at 1.5 T were obtained for all patients. The efficacies of these three imaging techniques were compared by calculating the contrast-to-noise ratio, as indicative of conspicuousness between a tumor-affected and a normal pancreas. As for adenocarcinoma, our results indicated that the usefulness in detecting the tumor was high, decreasing in the order dynamic contrast images > fat suppression images > plain images, and that the difference between any two of these three types of image was statistically significant. On the other hand, these imaging techniques showed no statistically significant difference in detecting islet cell tumors. In conclusion, dynamic MRI is the best method for detecting pancreatic adenocarcinoma. As the fat suppression technique has the advantage of being non-invasive, this method is suitable for screening studies of pancreatic adenocarcinoma. However, no advantage was recognized in using the fat suppression technique for detecting an islet cell tumor in comparison with plain MRI.  相似文献   

19.
The Minnesota Multiphasic Personality Inventory—2 (MMPI—2) Validity scales (L, F, and K) were used to identify subgroups of inpatients seeking treatment for alcoholism and to determine the extent that assessed test-taking attitude could be generalized to other alcoholism assessment instruments. Cluster analysis of the inpatients receiving treatment for alcoholism identified 3 distinct response style subgroups: defensive, straightforward, and exaggerated. These patterns were confirmed in a 2nd sample. Calibration equations were generated and used to classify a subsequent sample into subgroups, and expected differences were found across the subgroups on the Alcohol Use Inventory (J. L. Horn, K. W. Wanberg, & F. M. Foster, 1987) and the Inventory of Drinking Situations (H. M. Annis, 1982). These preliminary results suggest that MMPI—2 response style is associated with response to other alcohol abuse assessment instruments. Future research examining the relationship between test-taking attitude and treatment involvement and outcome is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号