36 research outputs found
A simple and rapid method for assessing similarities among directly observable behavioral effects of drugs: PCP-like effects of 2-amino-5-phosphonovalerate in rats
Directly observable behavioral effects of the N-methyl- D -aspartate (NMDA) receptor antagonist 2-amino-5-phosphonovalerate (AP5) (10–1,000 mg/kg IP, 0.18–5.6 μmol/rat ICV) and of phencyclidine (PCP) (3.2–56 mg/kg IP, 0.032–3.2 mg/rat ICV), ketamine (10–100 mg/kg), amphetamine (1–18 mg/kg), apomorphine (0.1–5.6 mg/kg), chlordiazepoxide (1–100 mg/kg), and pentobarbital (3.2–56 mg/kg) were studied in rats. Pharmacologically specific results were obtained rapidly and reliably, using a cumulative dosing procedure. Cluster analysis grouped the drug treatments, on the basis of their similarities in producing different behavioral activities, into three main clusters; characteristically, stimulant drugs (amphetamine, apomorphine) produced sniffing and gnawing; PCP-like drugs (PCP, ketamine) produced locomotion, sniffing, swaying and falling; sedative drugs (pentobarbital, chlordiazepoxide) produced loss of righting. The behavioral effects of ICV administration of AP5 were more similar to the effects of PCP-like drugs than to the effects of either stimulant or sedative drugs, thus supporting the hypothesis that the behavioral effects of PCP-like drugs may result from reduced neurotransmission at excitatory synapses utilizing NMDA preferring receptors. The present procedure is simple, rapid and may provide a useful approach in the classification of behaviorally active drugs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46445/1/213_2004_Article_BF00518181.pd
Photovoltaic Effects in Rutile
The ultraviolet photovoltaic response of barrier‐layer cells formed from single‐crystal rutile has been investigated. Typical samples have response maxima at 3200 Å, a D* of 109 cm cps1∕2∕W, and time constants of 100 μsec. Variations in time constant over several orders of magnitude have been observed, dependent largely on preparative technique. The effect of surface treatment on cell characteristics is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70227/2/JAPIAU-35-6-1868-1.pd
Effects of Traditional vs. iPad-Enhanced Aerobic Exercise on Wayfinding Efficacy and Cognition: A Pilot Randomized Controlled Trial
The purpose of this pilot study was to test the feasibility and efficacy of an iPad-enhanced aerobic exercise intervention designed to enhance wayfinding efficacy and performance and relevant cognitive functioning among middle-aged adults at risk for cognitive impairment. Twenty-seven low active adults (21 females) aged 45 to 62 years (51.22 ± 5.20) participated in a ten-week randomized controlled trial. Participants were randomized to an iPad-enhanced aerobic exercise group (experimental group) or an aerobic exercise-only group (control group) following baseline assessment. Both groups exercised at 50% to 75% of age-predicted heart rate maximum for 30 to 50 min/d, 2 d/wk for 10 weeks. During aerobic exercise, the experimental group engaged in virtual tours delivered via iPad. Baseline and post-intervention assessments of wayfinding self-efficacy, wayfinding task performance, cognitive functioning, electroencephalogram (EEG), and psychosocial questionnaires were administered. The results suggest that ten weeks of iPad-enhanced, moderately intense aerobic exercise had specific effects on wayfinding self-efficacy; however, no statistical differences were found between groups on the behavioral wayfinding task or spatial memory performance at follow-up. Performance scores on an inhibitory attentional-control cognitive assessment revealed significant differences between groups, favoring the experimental group (p < 0.05). Virtual reality-enhanced aerobic exercise may prove to be an effective method for improving cognitive function and increasing confidence to navigate real-world scenarios among individuals at risk of cognitive impairment
Neutrophils, eosinophils, and intraepithelial lymphocytes in the squamous esophagus in subjects with and without gastroesophageal reflux symptoms
Abstract
Whilst intraepithelial lymphocytes (IELs) are considered normal within the distal esophageal mucosa, they have an increasingly recognised role in the pathogenesis of reflux esophagitis, and IEL quantification establishes the diagnosis of lymphocytic esophagitis. Knowledge regarding the upper limit of a normal IEL count in health is lacking. We studied 117 non-healthcare seeking adult volunteers from a random community sample (the Kalixanda study) with esophageal biopsies 2 cm above the gastroesophageal junction. Subjects were divided into four groups based on the presence or absence of gastro-esophageal reflux symptoms and/or esophagitis on endoscopy. Asymptomatic subjects with no endoscopic esophagitis were selected as controls, and the cell counts in this group were used to define the upper limit of normal of IELs, eosinophils and neutrophils. The entire sample was used to identify independent predictors of increased cellular counts by logistic regression analysis. None of the healthy controls had an IEL count of more than three per five high power fields (HPF), and therefore this was considered as the upper limit of normal; no controls had eosinophils or neutrophils in esophageal biopsies. Independent predictors of an elevated IEL count were spongiosis on histology (OR 11.17, 95% CI 3.32–37.58, P < 0.01) and current smoking (OR 4.84, 95% CI 1.13–2.71, P = 0.03). A receiver operating characteristics analysis concluded that a threshold of 3 IELs/5HPFs performs best in predicting reflux symptoms when a normal esophageal mucosa is visualized on endoscopy (sensitivity = 100.0%, specificity = 35.2%). The healthy esophageal mucosa does not contain more than three IELs per five HPF in the distal esophagus