Biomedical subjects

Dean C Williams

Publications and source records attributed to Dean C Williams.

6 recordsLinked to original sources

PubMed2007

Relevance of donepezil in enhancing learning and memory in special populations: a review of the literature.

This review discusses the laboratory and clinical research supporting the rationale for the efficacy of donepezil (Aricept USA) in enhancing cognition in autism, Alzheimer disease, Down syndrome, traumatic brain injury, Attention Deficit Hyperactivity Disorder (ADHD), and schizophrenia. While preliminary animal models have shown effective, human studies exclusive of Alzheimer disease are sparse. Although attention and memory are unlikely a sole operation of the cholinergic system, evidence indicates a promising direction for further examination of this hypothesis in autism. Studies that examine changes in operationally defined behaviors and reliable and valid measure of changes in attention and memory are needed.

Alzheimer Disease↗

PubMed2006

Use of an automated, load-distributing band chest compression device for out-of-hospital cardiac arrest resuscitation.

CONTEXT: Only 1% to 8% of adults with out-of-hospital cardiac arrest survive to hospital discharge. OBJECTIVE: To compare resuscitation outcomes before and after an urban emergency medical services (EMS) system switched from manual cardiopulmonary resuscitation (CPR) to load-distributing band (LDB) CPR. DESIGN, SETTING, AND PATIENTS: A phased, observational cohort evaluation with intention-to-treat analysis of 783 adults with out-of-hospital, nontraumatic cardiac arrest. A total of 499 patients were included in the manual CPR phase (January 1, 2001, to March 31, 2003) and 284 patients in the LDB-CPR phase (December 20, 2003, to March 31, 2005); of these patients, the LDB device was applied in 210 patients. INTERVENTION: Urban EMS system change from manual CPR to LDB-CPR. MAIN OUTCOME MEASURES: Return of spontaneous circulation (ROSC), with secondary outcome measures of survival to hospital admission and hospital discharge, and neurological outcome at discharge. RESULTS: Patients in the manual CPR and LDB-CPR phases were comparable except for a faster response time interval (mean difference, 26 seconds) and more EMS-witnessed arrests (18.7% vs 12.6%) with LDB. Rates for ROSC and survival were increased with LDB-CPR compared with manual CPR (for ROSC, 34.5%; 95% confidence interval [CI], 29.2%-40.3% vs 20.2%; 95% CI, 16.9%-24.0%; adjusted odds ratio [OR], 1.94; 95% CI, 1.38-2.72; for survival to hospital admission, 20.9%; 95% CI, 16.6%-26.1% vs 11.1%; 95% CI, 8.6%-14.2%; adjusted OR, 1.88; 95% CI, 1.23-2.86; and for survival to hospital discharge, 9.7%; 95% CI, 6.7%-13.8% vs 2.9%; 95% CI, 1.7%-4.8%; adjusted OR, 2.27; 95% CI, 1.11-4.77). In secondary analysis of the 210 patients in whom the LDB device was applied, 38 patients (18.1%) survived to hospital admission (95% CI, 13.4%-23.9%) and 12 patients (5.7%) survived to hospital discharge (95% CI, 3.0%-9.3%). Among patients in the manual CPR and LDB-CPR groups who survived to hospital discharge, there was no significant difference between groups in Cerebral Performance Category (P = .36) or Overall Performance Category (P = .40). The number needed to treat for the adjusted outcome survival to discharge was 15 (95% CI, 9-33). CONCLUSION: Compared with resuscitation using manual CPR, a resuscitation strategy using LDB-CPR on EMS ambulances is associated with improved survival to hospital discharge in adults with out-of-hospital nontraumatic cardiac arrest.

Aged↗

PubMed2006

Intertrial sources of stimulus control and delayed matching-to-sample performance in humans.

Two experiments compared delayed matching-to-sample (DMTS) accuracy under 2 procedures in adults with mental retardation. In the trial-unique procedure, every trial in a session contained different stimuli. Thus, comparison stimuli that were correct on one trial were never incorrect on other trials in that session (or vice versa). In the 2-sample DMTS procedure, the same 2 comparison stimuli were presented on each trial, and their function changed quasi-randomly across trials conditional upon the sample stimulus. Across 2 experiments, 7 of 8 subjects showed the highest overall accuracy under the trial-unique procedure, and no subject showed consistently higher accuracy under the 2-sample procedure. Negative, exponential decay functions fit to logit p values showed that this difference was due largely to the steeper delay-mediated decline in sample control for the 2-sample procedure. Stimulus-control analyses indicated that, under the 2-sample procedure, the selection of the comparison stimulus on Trial N was often controlled by the comparison stimulus selection on Trial N-1 rather than the Trial-N sample stimulus. This source of competing stimulus control is not present in trial-unique procedures. Experiment 2 manipulated intertrial interval duration. There was a small but consistent increase in accuracy as a function of intertrial interval duration under the 2-sample procedure, but not under the trial-unique procedure.

Adult↗

PubMed2003

Rate-decreasing effects of the atypical neuroleptic risperidone attenuated by conditions of reinforcement in a woman with mental retardation.

Effects of two doses of risperidone on the performance of a matching task under tangible reinforcement and nonreinforcement conditions were measured in a woman with mental retardation. In both conditions, time to complete the task increased and response rates decreased under two doses of risperidone. Accuracy was generally unchanged. These changes were much smaller in the tangible reinforcement condition; thus, reinforcement seemed to protect performance from the rate-decreasing effects of risperidone.

Adult↗

PubMed2003

Recombinative generalization of within-syllable units in nonreading adults with mental retardation.

Two adults with mental retardation demonstrated the recombination of within-syllable units (onsets and rimes) using a spoken-to-printed-word matching-to-sample (MTS) procedure. Further testing with 1 participant showed comprehension of the printed words. Printed-word naming was minimal before, but greater after, comprehension tests. The findings suggest that these procedures hold promise for further basic and applied analyses of word-attack skills.

Adult↗

PubMed2002

Multimodal evaluation of risperidone for destructive behavior: functional analysis, direct observations, rating scales, and psychiatric impressions.

Risperidone, an atypical neuroleptic, has become a popular option for treating destructive behaviors of persons with developmental disabilities. A few studies have been conducted that evaluate the effects of risperidone on destructive behavior; however, none of these studies have combined objective measures with rating scales to evaluate the effects of risperidone on destructive behavior across home and clinical settings. This study evaluated the wide range of effects of risperidone on destructive behavior of 2 persons with developmental disabilities using weekly functional analysis sessions, daily observations, hourly home data, weekly rating scales, and monthly psychiatric impressions. Results indicate that risperidone does decrease destructive behavior and that, for the most part, all of the various measures yielded similar results.

Adult↗