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Biomedical subjects

L Charles

Publications and source records attributed to L Charles.

25 records · Page 2Linked to original sources
PubMed1981

Optimal dosages of methylphenidate for improving the learning and behavior of hyperactive children.

The effects of methylphenidate dosages were assessed in 42 hyperactive children who were tested off drug at the beginning and end of an 18-week study and 2 weeks after initiation of various dosages. Initial methylphenidate doses of 0.2 mg/kg were increased biweekly until 0.8 mg/kg was reached or the child showed adverse personality or physiologic effects. Measures included an objective test of the ability to sustain attention and behavioral ratings completed by parents and teachers. Data were analyzed separately for groups attaining low, moderate, and high maximum doses (0.4, 0.6, and 0.8 mg/kg, respectively). For all dosage groups behavior and attention improved with increased dosage, and the best scores were associated with the highest drug levels. In contrast to previous reports, differences in optimal dosage levels for behavior and cognitive performance were not seen. This discrepancy may result from the lack of individual titration based on tolerance in earlier reports.

Attention↗
PubMed1980

Direct fractionation of genes by preparative electrophoresis of Bacillus subtilis DNA.

Discontinuous electrophoresis through agarose has been shown to be a satisfactory method for preparation of biologically active restriction fragments from milligram quantities of DNA. The DNA is obtained in sufficient quantity for: (1) direct use in genetic transformation, (2) the production of multiple-dimensional restriction analyses, or (3) use as a high-resolution hybridization probe.

Bacillus subtilis↗
PubMed1979

Long-term use and discontinuation of methylphenidate with hyperactive children.

The long-term effects of methylphenidate on the behavior and academic functioning of hyperactive children are described. 36 children having a positive response to methylphenidate entered a three-year follow-up study in which they were closely monitored physically, behaviorally and psychometrically. During this period 13 children spontaneously discontinued medication: there were no statistically significant differences between them and the children who continued medication in terms of age, IQ or ratings at initial interview. The greatest improvement in performance occurred in the early months of treatment, but was only partially maintained during long-term therapy and little further change occurred after medication was discontinued. The findings indicate that sustained improvement is related to factors other than continued medication, and they suggest that drug therapy should be regarded as a short-term intervention until more positive social and school behavior can be established.

Achievement↗
PubMed1979

Effects of methylphenidate on hyperactive children's ability to sustain attention.

The purposes of this study were to investigate the attentional characteristics of hyperactive children, the relationship of subjective and objective measures of these characteristics, and the effects of methylphenidate on these measures of attention. Forty-five hyperactive children, ages 6 to 10 years, were entered into an 18-week study of the effects of methylphenidate (Ritalin) on attention. Measures included rating scales completed by teachers and parents and a vigilance task. All measures reflected significant changes during the period of investigation. Attention and behavior were significantly improved under drug conditions and significantly worsened when methylphenidate was discontinued. However, only performance on the objective measure returned to predrug levels; final off-drug parent and teacher ratings remained improved over initial reports. Parent ratings of behavior, and specifically of children's ability to attend, were unrelated to equivalent teacher ratings. Teachers' ratings of attention correlated significantly with performance on the vigilance task, discriminated between on-drug and off-drug conditions, and discriminated between children who obtained normal or near normal predrug scores on the objective measure and those who performed poorly on this measure. Methylphenidate improved attentional performance for children who had poor predrug scores on the vigilance task, but did not produce a statistically significant change on the scores of children with normal predrug performance.

Attention↗
PubMedDate not supplied

Development of the Logical Observation Identifier Names and Codes (LOINC) vocabulary.

The LOINC (Logical Observation Identifier Names and Codes) vocabulary is a set of more than 10,000 names and codes developed for use as observation identifiers in standardized messages exchanged between clinical computer systems. The goal of the study was to create universal names and codes for clinical observations that could be used by all clinical information systems. The LOINC names are structured to facilitate rapid matching, either automated or manual, between local vocabularies and the universal LOINC codes. If LOINC codes are used in clinical messages, each system participating in data exchange needs to match its local vocabulary to the standard vocabulary only once. This will reduce both the time and cost of implementing standardized interfaces. The history of the development of the LOINC vocabulary and the methodology used in its creation are described.

Classification↗
PubMedDate not supplied

The financial management of hospital equipment.

This paper outlines the main failings of the National Health Service in respect of its purchase and use of clinical and laboratory equipment. It emphasizes the need for proper inventories and demonstrates how they can aid the more efficient use of equipment by ensuring that all purchases within a Health District are co-ordinated and that named officers are responsible for individual pieces of equipment.

Biomedical Engineering↗