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Biomedical subjects

D Morrison

Publications and source records attributed to D Morrison.

At least 55 records · Page 3Linked to original sources
PubMed1984

Comparison of chemical analyses of hollow-fiber dialyzer extracts.

Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amebocyte lysate (LAL) test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested using three lysates and four LAL methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified using chromatographic methods. Results indicate that the LAL-reactive material is cellulose derived and is not pyrogenic.

Arginase↗
PubMed1984

Characterization of Limulus amoebocyte lysate-reactive material from hollow-fiber dialyzers.

Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amoebocyte lysate test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested before and after treatment with cellulase, using three lysates and four Limulus amoebocyte lysate methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified by chromatographic methods. Results indicate that the Limulus amoebocyte lysate reactive material is cellulose derived and not pyrogenic.

Cellulose↗
PubMed1984

Sensory integration therapy: a trial of a specific neurodevelopmental therapy for the remediation of learning disabilities.

In the population of learning-disabled (LD) children, there appears to be a subsample who demonstrate basic dysfunction in sensory integration. Previous research suggested that sensory integration (SI) therapy may be effective in improving the academic performance of this subsample of LD children. This study is a systematic replication of previous research on the effects of SI therapy on LD children. The 87 LD children in this study manifest moderate SI dysfunction, a vestibular processing disorder, perceptual deficits, and reading retardation. Data on a subgroup of 45 children with markedly depressed postrotary nystagmus are presented. After nine months of individual SI therapy, no systematic effects on any of the dependent variables were discernible. The implications of these findings for further research are discussed.

Child↗
PubMed1983

The acute effects of low flow oxygen and isosorbide dinitrate on left and right ventricular ejection fractions in chronic obstructive pulmonary disease.

The objectives of this study were to determine the effects of low flow oxygen and isosorbide dinitrate on rest and exercise biventricular ejection fractions in patients with chronic obstructive pulmonary disease and to relate these ejection fraction responses to changes in pressure and flow. Nine patients with stable, moderate to severe chronic obstructive pulmonary disease who had no prior history of heart failure performed supine exercise with simultaneous hemodynamic and radionuclide ventriculographic monitoring. Eight patients performed a second exercise during low flow oxygen breathing and five performed a third exercise after ingesting 10 mg oral isosorbide. Oxygen led to a decrease in exercise pulmonary artery pressure in all subjects and a decline in total pulmonary resistance in five of the seven in whom it was measured. Right ventricular ejection fraction increased 0.05 or more only in subjects who had a decrease in total pulmonary resistance. Isosorbide fed to an increase in rest and exercise right and left ventricular ejection fractions with simultaneous decreases in pulmonary artery pressure, total pulmonary resistance, blood pressure and arterial oxygen tension. These results suggest that in patients with chronic obstructive pulmonary disease but without a history of right heart failure, the right ventricular systolic functional response to low flow oxygen and isosorbide at rest and exercise is, in part, determined by changes in total pulmonary resistance. The chronic relation between right ventricular ejection fraction and pulmonary hemodynamics in patients with chronic obstructive pulmonary disease remains to be evaluated.

Blood Pressure↗
PubMed1983

The effect of pulmonary hypertension on systolic function of the right ventricle.

This study sought to determine if the right ventricular ejection fraction (RVEF) could be used to diagnose pulmonary hypertension noninvasively. The right ventricular ejection fraction was measured with gated blood pool radionuclide ventriculography and compared to hemodynamic measurements made within 48 hours in 57 subjects. There was a significant inverse relationship between the RVEF and pulmonary artery pressure (r = .57, p less than .001) and the sensitivity of RVEF greater than .45 in diagnosing pulmonary hypertension was .76. Other significant determinants of right ventricular function, including right coronary disease, left ventricular function and tricuspid regurgitation, were also considered.

Cardiac Output↗
PubMed1983

Reliability of the Southern California Postrotary Nystagmus Test with learning-disabled children.

The Southern California Postrotary Nystagmus Test (SCPNT) provides an objective assessment of nystagmus. Although depressed nystagmus duration as measured by the SCPNT is considered a major sign of vestibular dysfunction in learning-disabled children, the reliability of the SCPNT with this population has not been established. To study reliability of nystagmus duration in this population, 89 learning-disabled children were evaluated with the SCPNT. The results demonstrated that this sample had significantly depressed scores and more variability in scores than normal children. Intrascorer and test-retest reliabilities, although statistically significant, were lower than those established with normal children. A test-retest study of the reliability of placing a child in a deviant duration range over time significantly reduced reliability estimates. Clinicians using nystagmus duration scores in the evaluation of vestibular dysfunction in learning-disabled children should be sensitive to the variation in this measure in this population.

California↗
PubMed1982

Age-related response to two Haemophilus influenzae type b vaccines.

Two types of Hib vaccines were compared for efficacy and safety in 71 normal children in three age groups: 36 to 72 months, 15 to 18 months, and 6 to 8 months. One vaccine contained the Hib-specific capsular polysaccharide, PRP; the second vaccine contained PRP combined with pertussis vaccine, PRP-P. A third vaccine, DTP, was administered to a control group for each age. Anti-PRP antibody levels were greater after vaccination with PRP-P than after PRP in all three age groups. Immunoresponsiveness to both vaccines increased with age. A lower incidence of side effects was seen with both PRP (15%) and PRP-P (20%) than with DTP (56%). The results suggest that PRP-P is both well tolerated clinically and has greater immunogenicity than PRP.

Age Factors↗
PubMed1982

Once weekly pimozide versus fluphenazine decanoate as maintenance therapy in chronic schizophrenia.

In a double blind trial, 28 male chronic schizophrenic in-patients received either pimozide, given once weekly, or fluphenazine decanoate, given mostly once fortnightly. There was no difference in relapse rates over nine months. However, three-quarters of the patients on pimozide who completed the trial developed at least mild tardive dyskinesia. All patients on pimozide lost weight, the average loss being 5.4 kg (12 lbs). Plasma pimozide levels suggested satisfactory drug compliance. Plasma prolactin levels confirmed that in the pimozide group there was fluctuating dopamine receptor antagonism, while in the fluphenazine group average plasma prolactin levels throughout most of the interval between injections were at the upper limit of normal.

Adult↗
PubMed1982

An improved method of right ventricular gated equilibrium blood pool radionuclide ventriculography.

Gated blood pool radionuclide ventriculography provides a means for obtaining repeated studies of both cardiac ventricles with a single dose of radionuclide. Quantitative assessment of right ventricular (RV) function using this technique has been complicated by several technical problems. We describe a new method of RV blood pool analysis which attempts to solve these problems using well-established concepts for left ventricular (LV) blood pool analysis: (1) variable regions of interest; (2) computer edge detection with operator intervention; and (3) computer selected background. Results showed a strong linear correlation between gated first pass RV ejection fraction (RVEF) and the gated blood pool RVEF (n = 22; r = 0.93; blood pool RVEF = 0.03 + 0.89 X first pass RVEF; Sy.x = 0.04). There was also a strong linear correlation between LV and RV stroke counts in patients without valvular regurgitation, intracardiac shunts, or ventricular aneurysms (n = 19; r =0.86; RV counts = 72 + 0.94 X LV counts; Sy.x = 116). In terms of both of these validation standards this method proved superior to three published methods of RV blood pool analysis that used hand-drawn regions, and is suitable for analysis of rest, exercise, and intervention studies of RV function.

Adult↗
PubMed1981

Hypersecretion of gastric inhibitory polypeptide in nondiabetic children with cystic fibrosis.

Failure of secretion of an insulinotropic enteric hormone has been postulated as a cause for the impaired insulin secretion observed following a glycemic stimulus in children with cystic fibrosis (CF). Gastric inhibitory polypeptide (GIP), a hormone located primarily in the duodenum, is the main hormonal stimulus to insulin release from the gastrointestinal tract. To determine whether hyposecretion of GIP was present in CF subjects, GIP secretion was measured in 15 control children and ten children with CF, following a standard oral glucose tolerance test. None of the subjects was diabetic but the CF children demonstrated significant insulinopenia compared to the normal control subjects. GIP secretion in the CF children was significantly greater than in the normal control subjects (normal, 38.8 +/- 4.6 ng/ml . min; CF, 54.9 +/- 6.1 ng/ml . min, P less than .01). These findings indicate that there is increased production of GIP in CF children rather than impaired secretion as had been postulated. The demonstration of hypersecretion of GIP in nondiabetic insulinopenic individuals adds further support to the hypothesis that insulin exerts feedback control on GIP secretion.

Adolescent↗