Evaluation of the recombinant 38-kilodalton antigen of Mycobacterium tuberculosis as a potential immunodiagnostic reagent

The diagnosis of infection caused by Mycobacterium tuberculosis is of increased public health concern following increases in the number of cases in developed countries and major increases in developing countries associated with the spread of human immunodeficiency virus (HIV) infection. The specificity of purified protein derivative skin testing for the detection of infection is compromised by exposure to environmental mycobacteria. Examination of sputum detects the most infectious patients, but not those with extrapulmonary disease. The 38-kDa antigen of M. tuberculosis contains two M. tuberculosis-specific B-cell epitopes. We overexpressed the gene for this antigen in Escherichia coli and evaluated the recombinant product in in vitro assays of T-cell function and as a target for the antibody response in humans. The sensitivity and specificity of the antigen as a skin test reagent were also assessed in outbred guinea pigs. We found that 69% of healthy sensitized humans recognize the antigen in vitro, as manifested by both cell proliferation and the production of gamma interferon. Untreated patients initially have a lower frequency of response (38%); this recovers to 72% during therapy. A total of 292 patients (20 with HIV coinfection) and 58 controls were examined for production of antibody to the 38-kDa antigen by using a commercially available kit. The sensitivity of the test in comparison with that of culture was 72.6%, and the specificity was 94.9%. The antigen was also tested for its ability to induce skin reactions in outbred guinea pigs sensitized by various mycobacterial species. The antigen provoked significant skin reactions in M. tuberculosis-, M. bovis BCG-, and M. intracellulare-sensitized animals. The significance of these findings and the usefulness of this antigen in immunodiagnosis are discussed.     

Myocarditis in children with dilated cardiomyopathy: incidence and outcome after dual therapy immunosuppression

BACKGROUND: The true incidence and prognosis of myocarditis in children with acute dilated cardiomyopathy (DCM) at presentation remains uncertain. This study examines the incidence of lymphocytic myocarditis in a consecutive cohort of children with acute DCM at presentation and outcome after dual therapy immunosuppression with cyclosporine and steroids. METHODS: Twenty-nine consecutive children with acute DCM underwent early endomyocardial biopsy. Children with "definite" myocarditis comprised group I (n = 9) and were treated with cyclosporine and prednisolone. Group II (n = 2) had "borderline" myocarditis, and group III (n = 18) nonspecific histologic findings. Outcome was assessed by echocardiographic measurement of left ventricular end-diastolic dimension and fractional shortening, with follow-up endomyocardial biopsy in group I subjects. RESULTS: Myocardial inflammation with or without myocardial necrosis (groups I and II) was present in 38% of all cases. There were no initial clinical, electrocardiographic, or echocardiographic features to distinguish patients in group I from patients in group III. At presentation, the mean +/- SEM left ventricular end-diastolic dimension and fractional score-Z scores of group I patients were 4.6 +/- 1.7 and -5.1 +/- 0.8, respectively, compared with 0.8 +/- 0.3 and -0.9 +/- 0.4, respectively, at withdrawal of immunosuppression (p < 0.001 for both). Both of these parameters did not differ significantly from normal controls at least follow up. Two group I patients had a biopsy-proven relapse after withdrawal of therapy that responded to reinstitution of immunosuppression. At latest follow-up, all nine group I patients had regained normal left ventricular function compared with four of 18 group III patients (p < 0.001). CONCLUSION: Lymphocytic myocarditis is frequent in children with dilated cardiomyopathy and cannot be predicted from noninvasive investigations. The use of cyclosporine and steroids is associated with a favorable outcome, and a controlled trial of dual therapy immunosuppression in children is therefore warranted.     

Reading aloud: Qualitative differences in the relation between stimulus quality and word frequency as a function of context.

Virtually all theories of visual word recognition assume (typically implicitly) that when a pathway is used, processing within that pathway always unfolds in the same way. This view is challenged by the observation that simple variations in list composition are associated with qualitative changes in performance. The present experiments demonstrate that when reading aloud, the joint effects of stimulus quality and word frequency on response time are driven by the presence/absence of nonwords in the list. Interacting effects of these factors are seen when only words appear in the experiment, whereas additive effects are seen when words and nonwords are randomly intermixed. One way to explain these and other data appeals to the distinction between cascaded processing (or interactive activation) on the one hand versus a thresholded mode of processing on the other, with contextual factors determining which mode of processing dominates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related positivity enhancement is not universal: Older Chinese look away from positive stimuli.

Socioemotional selectivity theory postulates that with age, people are motivated to derive emotional meaning from life, leading them to pay more attention to positive relative to negative/neutral stimuli. The authors argue that cultures that differ in what they consider to be emotionally meaningful may show this preference to different extents. Using eye-tracking techniques, the authors compared visual attention toward emotional (happy, fearful, sad, and angry) and neutral facial expressions among 46 younger and 57 older Hong Kong Chinese. In contrast to prior Western findings, older but not younger Chinese looked away from happy facial expressions, suggesting that they do not show attentional preferences toward positive stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of brefeldin-A on Golgi morphology in human cultured fibroblasts observed in three-dimensional stereo scanning electron microscopy

Brefeldin A (BFA) has been reported to cause disassembly of the Golgi. We have used three-dimensional (3-D) high-resolution scanning electron microscopy (HRSEM) to investigate these effects in human skin fibroblast cells. The spontaneous reassembly during prolonged exposure to BFA and some effects of forskolin were observed. A BFA concentration of 5μg/ml caused Golgi complexes to become vesicular, resulting in a progressive decrease in the size of the Golgi. Morphologic changes were visible within 2 min of BFA incubation, and by 30 min no identifiable Golgi could be found. Spontaneous reassembly of the Golgi apparatus upon the removal of the BFA or with continued long-term exposure with BFA could not be confirmed. Preliminary experiments with forskolin were not effective in reversing or inhibiting the effects of BFA in human fibroblast cells grown in culture. This inability for spontaneous reassembly and nonreversal by forskolin may reflect a differential effect of BFA in various cell types. HRSEM has proven to be useful for observing 3-D morphologic effects of BFA in Golgi.     

Cholesterol, endothelial function and cardiovascular disease

Poster presentations have proved to be a popular method of displaying information at conferences, and are being used increasingly as a teaching method. Innovative strategies for teaching and assessing research need to facilitate students' achievement of research skills required for practice. These are outlined by the Department of Health, and emphasize the development of research literacy. Using the poster presentation as a teaching and assessing strategy on diploma level courses (Project 2000 and ENB 870 introduction to the Understanding and Application of Research) has proved to be valuable in developing vital research awareness skills and in harnessing enthusiasm for research. Students imply a sense of achievement gained through the process of developing the poster and the production of the poster itself. Herein lies the value of the poster presentation, for it allows the development of crucial research literacy skills which can be widely used in professional practice and future professional education.     

Engaging the aging workforce: The relationship between perceived age similarity, satisfaction with coworkers, and employee engagement.

Business publications and the popular press have stressed the importance of creating conditions for meaningful employee expression in work roles, also known as engagement. Few empirical studies, however, have examined how individual or situational factors relate to engagement. Consequently, this study examines the interplay between employee age, perceived coworker age composition, and satisfaction with older (older than 55) and younger (younger than 40) coworkers on engagement using a sample of 901 individuals employed in the United Kingdom. Results indicated that satisfaction with one's coworkers related significantly to engagement. Moreover, perceived age similarity was associated with higher levels of engagement among older workers when they were highly satisfied with their coworkers over 55 and lower levels of engagement when they were not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improvements in daily functioning after deep brain stimulation of the thalamus for intractable tremor

Deep brain stimulation (DBS) of the thalamus reduces tremor in patients with essential tremor (ET). However, few studies have determined the degree of improvement in daily functioning associated with DBS. We developed a self-report Tremor Activities of Daily Living Scale (TADLS) to compare daily functioning with the stimulator turned on and off. Patients rated their performance on the 30 items of the TADLS with the stimulator turned off and then on. They also performed 10 activities under the supervision of a clinician who rated their functional ability with stimulation off and then on. There was a 58% improvement in self-rated TADLS scores in patients with DBS with the stimulator on compared with stimulation off. When activities were rated by the clinician, the average improvement in functioning with the stimulator on was 54%. There were reasonably high correlations between patient and clinician ratings of functioning. ET patients have a marked improvement in daily functioning with thalamic DBS.     

Models of visual word recognition: When obscuring the stimulus yields a clearer view.

It is well known that visual word recognition is influenced by context, word frequency, and stimulus quality. A processing account is outlined in which stimulus quality affects the orthographic input lexicon, whereas context influences both the orthographic input lexicon and the semantic system. Word frequency exerts its primary effects on the pathways that link lexical systems with each other and with the semantic system. Previous findings that are problematic for alternative models along with the results of 2 new experiments are consistent with this account. (PsycINFO Database Record (c) 2010 APA, all rights reserved)