Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT

A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics.     

The interaction of post-weaning housing conditions and prenatal drug effects on behaviour

Offspring of rats given oral doses of imipramine (5 mg/kg) from 14–21 days prior to mating till parturition or vitamin-A (100000 i.u./kg) between days 8 and 10 of gestation were reared, after weaning, in deprived or enriched environments. When tested in both a Henderson-type maze and a swimming maze no behavioural effects due to prenatal drug exposure were observed when the Ss were reared in a deprived environment. When the Ss were reared in an enriched environment the maze performance of those animals which had been exposed to imipramine or vitamin-A was significantly inferior to that of the control animals. The implications of these findings are discussed with respect to environmental interaction with prenatal drug effects on behaviour.     

Integrating service learning into a curriculum to reduce health risks at alternative high schools

Service learning has been identified as a promising approach to reduce sexual risk behavior, among other outcomes. This study used qualitative data analysis to offer suggestions for optimally integrating service learning into a program to reduce sexual risks among alternative school students. Data were collected from student participants in the All4You! Project using classroom materials, focus groups, and individual interviews. Project educators and project staff also provided data through summary forms and field notes. Qualitative data analysis revealed 5 strategies for creating positive service experiences for alternative school students: (1) find appropriate service-learning sites, (2) create staff support, (3) maintain appropriate student participation and behavior; (4) enhance student reflection on service-learning experiences, and (5) address students' self-images.     

Use of evidence in decision models: an appraisal of health technology assessments in the UK since 1997

OBJECTIVES: To review the sources and quality of evidence used in the development of economic decision models in health technology assessments (HTAs). METHODS: All economic decision models developed as part of the NHS Research and Development HTA Programme between 1997 and 2003 were reviewed. Quality of evidence was assessed using a hierarchy of data sources developed for economic analyses. RESULTS: Decision models are parameterized using diverse sources of evidence (e.g. randomized controlled trials, observational studies, expert opinion). Evidence on the main clinical effect was mostly identified and quality assessed as part of the companion systematic review/meta-analysis of the HTA and therefore reported in a transparent and reproducible way. For the other model inputs (i.e. adverse events, baseline clinical data, resource use and utilities), the search strategies for identifying relevant evidence were rarely made explicit and in a number of reports the sources of specific evidence were unclear due to poor reporting. CONCLUSIONS: A more formal and replicable approach to identification and assessment of quality of model inputs is required to reduce the 'black box' nature of decision models, and lead to less scepticism regarding model outputs.     

Topographic analysis of the innervation of the rat neocortex and hippocampus by the basal forebrain cholinergic system

The basal forebrain-cortex connections of the rat were topographically mapped by retrograde tracer methods; and their contribution to the cholinergic innervation of the cortex was assessed by excitotoxin lesions placed in the rostral and caudal aspects of the complex. Discrete injections of tracer into frontal cortex labeled the prominent multipolar acetylcholinesterase (AchE)-positive cells of the ventromedial globus pallidus. Injections of tracer into the parietal cortex labelled cells in the ventral globus pallidus, the underlying substantia innominata, and the lateral hypothalamus. Separate injections of Fast Blue and Nuclear Yellow in the frontal and in the parietal cortex resulted in double-labeled cells in the ventral globus pallidus, which indicates that at least some of these cells may possess collateralizing axons. The cingulate cortex is innervated predominantly by neurons in the nucleus of the horizontal limb of the diagonal band. The occipital cortex was also shown to receive a projection primarily from the nucleus of the horizontal limb of the diagonal band. The hippocampal formation is innervated primarily by cells located in the vertical limb of the diagonal band and in the medial septum. Consistent with the results of the retrograde tracing studies, excitotoxin lesions affecting the diagonal band and medial septum decreased choline acetyltransferase (CAT) activity up to 40% on the occipital cortex and by 64% in the hippocampus, but did not affect CAT activity in the rostral neocortex. In contrast, ibotenate lesions of the caudal ventral globus pallidus and substantia innominata caused decreases in CAT activity in the frontal cortex of up to 65% without affecting enzyme activity in the hippocampal formation. The results of the present study provide details on the topographic organization of the cortical projections originating in the basal forebrain complex and indicate that these neurons are the predominant source of cortical cholinergic innervation.