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Biomedical subjects

R Nelson

Publications and source records attributed to R Nelson.

At least 289 records · Page 16Linked to original sources
PubMed1981

Case report. Clindamycin associated pseudomembranous colitis.

Pseudomembranous colitis is rare in children. We describe a case associated with clindamycin in which Clostridium difficile and its enterotoxin were isolated from the stool. Treatment with oral vancomycin brought about a prompt and complete recovery.

Child↗
PubMed1981

Pressures created by dental injections.

In routine dental practice, anesthetic solutions are injected into tissue sites of widely different distensibilities, under a variety of pressures. The purpose of the present study, during simulated dental practice, was to determine the maximum injection pressures obtained by clinicians during injections in dogs. Regular aspirating dental syringes were used together with dental anesthetic cartridges filled with isotonic saline. Maximum operator injection pressures ranged from 330 to 660 psi (17,061-34,122 mmHg). Those injection sites that were least distensible gave the highest maximum injection pressures: interosseous (21,559 mmHg); incisive papilla (18,224 mmHg); periodontal (17,630 mmHg); hard palate (11,322 mmHg); and intrapulpal (8918 mmHg). More distensible tissue sites gave much lower pressures. The data indicate that dental injection pressures vary widely from several hundred mmHg to several hundred psi, depending on the clinician's physical effort and the distensibility of the tissue.

Anesthesia, Dental↗
PubMed1981

Parental assessment of temperament in handicapped children.

The New York Longitudinal Study (NYLS) Parent Questionnaire assesses parental report of children's temperament on nine variables: Mood, distractibility, persistence, activity, rhythmicity, adaptability, approach-withdrawal, threshold and intensity. The present research was designed to assess the interrater reliability of this instrument and to provide cross-validation data regarding the nine scales. Questionnaires were validly completed by both parents of 47 children who had previously been evaluated at the Neuropsychology Laboratory of the Louisiana State University Medical Center. For each of the nine temperament variables, the scores obtained by each child when rated by his or her mother was significantly correlated with the score received on that variable when rated by the father. Thus, under the limitation imposed by the research design, it appears that parents are relatively consistent when evaluating the temperamental characteristics of their children. The correlations between each individual item and the factor it loads on were consistently highly significant. The nine temperamental variables are adequately assessed by the items included in the NYLS Questionnaire.

Attention Deficit Disorder with Hyperactivity↗
PubMed1981

Deprenyl in Parkinson disease.

(-)Deprenyl, a specific monoamine oxidase subtype B inhibitor (MAOI-B), has been reported to be a safe and valuable adjunct to conventional treatment of parkinsonism. A double-blind, clinical comparison of (-)deprenyl with placebo was undertaken in 11 parkinsonian patients; the efficacy of 10 mg daily was studied over 4 weeks. In four cases the clinical score for parkinsonian deficits improved during deprenyl therapy, and in five it deteriorated; there was no change in one patient. Two subjects failed to complete the study. (-)Deprenyl induced euphoria and insomnia. It was concluded that any advantages deriving from the use of (-)deprenyl in parkinsonism are limited, and probably dominated by its elevation of mood. Biochemical analysis failed to reveal any significant increase in platelet or plasma catecholamine concentrations during deprenyl therapy. There was, however, a significant decrease in plasma epinephrine (p < 0.05) and platelet MAO activity (p < 0.005).

Adult↗
PubMed1981

Effect of surface porosity on early thrombogenicity using vascular grafts with two surfaces in sequence.

This experiment addresses the multifactorial dilemma of defining the ideal performance parameters of small internal diameter vascular grafts. We found silicone rubber vascular grafts with smooth surfaces remain acutely free of thrombotic deposits whereas grafts with rough surfaces promote a dispersed thrombus formation. This study also questions the concept that the thrombogenicity of one surface determines the thrombotic response of different and adjacent flow surfaces in the blood flow. Here the distinction between response to each surface was abruptly delineated and equal in intensity regardless of proximal or distal positioning. By studying the 2 surfaces in sequence, surface properties were evaluated using the minimal number of experiments by mitigating the effects of interanimal variability. This is an important consideration in an era of "cost accountability".

Animals↗
PubMed1980

Coeliac disease and HLA: a family study.

In a family study of coeliac disease, HLA types in fifty-three patients and their relatives were examined. There are no differences in HLA frequencies between child and adult patients. Comparison with a random series of normal controls shows increased frequencies in patients of HLA-A1 and B8, while the family material shows that there is also an excess of haplotype 1-8. The excess of homozygotes is thought not to be a factor in the aetiology. Intrafamilial analysis shows that only B8 is significantly associated with the disorder. It is argued that the HLA association does not indicate a 'coeliac gene' but that the B8 allele is a major gene in a polygenic system affecting the disorder.

Adult↗
PubMed1979

Relationship between bacterial binding to lymphocytes and clinical features in chronic lymphocytic leukemia.

In previous studies we showed that spontaneous bacterial adherence can be used to identify human lymphocyte subpopulations and to demonstrate variable binding patterns in chronic lymphocytic leukemia (CLL). In this study, 10 strains of bacteria of different genera and species were used in blood smears from 24 CLL patients to determine the percentages of lymphocytes that bind bacteria. From these percentages, binding indices were calculated. The symptoms and other laboratory tests were independently recorded and the stages determined. When the two sets of data were compared, relatively low binding indices were found in symptomatic patients or in Stages III and IV; relatively high binding indices were found in asymptomatic patients or in Stages I and II. We suggest that with progression of leukemia, lymphocytes with less "lectin" recognition potential are selected and escape any control mechanism of proliferation.

Aged↗
PubMed1979

The use of visual feedback to control vocal intensity and nasalization.

A device which provides visual feedback of vocal intensity, nasalization, or a ratio of nasalization to vocal intensity, is described. The device was used in several experiments in which control of vocal intensity was a necessary component. Normal and hypernasal speakers were able to control their vocal intensities successfully when using the visual display. The display also was used in an experiment designed to determine how well normal speakers can manipulate their nasalization without visual feedback and whether they improve when feedback is provided. Subjects manipulated their nasalization first without feedback, then with feedback, then, again, without feedback. The subjects' performance improved when feedback was provided and determined when feedback was removed. It appears that this device is useful for many applications in a variety of settings.

Adult↗
PubMed1979

Relationship between plasma, RBC, and CSF lithium concentrations in human subjects.

Simultaneous measurement of plasma, RBC, and plasma lithium concentrations took place with 17 inpatients chronically treated with lithium, at various times after the last lithium dose. RBC lithium levels were significantly higher than CSF lithium levels. Specimens drawn 10 or more hours after the last dose showed higher RBC and CSF lithium and lower plasma lithium than specimens drawn 4 or less hours after the last lithium dose. None of the lithium measurements differentiated manic-depressives from schizophrenics or schizoaffectives. Plasma, RBC, and CSF lithium all intercorrelated highly and equally.

Adult↗