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Biomedical subjects

D A Stump

Publications and source records attributed to D A Stump.

61 records · Page 4Linked to original sources
PubMed1983

Comparison of the effects of intravenous papaverine hydrochloride and oral pavabid HP capsulets on regional cerebral blood flow in normal individuals.

A single-blind study was conducted in 13 right-handed normal male subjects to compare the effects of oral and i.v. papaverine on regional cerebral blood flow (rCBF). Six xenon-133 inhalation rCBF measurements were performed on each subject; three tests--baseline, placebo, and drug evaluations--were carried out on each of two separate days. The oral and i.v. drugs were randomized for first-day administration. rCBF, measured as flow gray (FG), increased significantly (p less than or equal to 0.001) from baseline with both drug forms. Increases of 10.53% and 13.94% (left and right hemispheres, respectively) were demonstrated 90 min after a single 600-mg dose of oral papaverine. Increases of 5.09% and 8.69%, respectively, were recorded immediately after a single 100-mg dose of i.v. papaverine. FG also increased significantly (p less than or equal to 0.001) for both drug forms when compared to that of placebo. Placebo produced only a slight increase (not significant) with both the oral and i.v. groups. The data show increasing rCBF in normal subjects.

Administration, Oral↗
PubMed1977

Regional cerebral blood flow statistical patterns and psychological performance in multi-infarct dementia and Alzheimer's disease.

Multivariate data analysis statistical procedures were applied to identify regional cerebral blood flow (rCBF) patterns in patients with multi-infarct dementia (M.I.D.) and Alzheimer's disease (A.D.) when compared to a control group (C.). A fronto-temporal-parietal pattern was identified for the A.D. group. The M.I.D. group demonstrated a predominant temporal parietal pattern. A discriminant function analysis classified 96% of the A.D. and C. patients correctly. One hundred per cent hit rate was obtained in discriminating between M.I.D. and C. Discrimination of A.D. and M.I.D. obtained 82% diagnostic accuracy. When the three groups were compared the hit rate was 93%. Mean rCBF and mean relative weight of the gray matter (Wg) differences were found when each dementia group was compared with C.M.I.D. and A.D. did not differ in mean rCBF but significant differences were found for Wg, with M.I.D. having greater reduction. The performance on standardized psychological tests of two independent samples of A.D. and M.I.D. were compared. The Memory Quotient from the Wechsler Memory Scale was consistently more imparied for the A.D. group. No correlation between degree of psychological impairment and rCBF or Wg reduction was found.

Adult↗
PubMed1976

Intellectual performance in multi-infarct dementia and Alzheimer's disease a replication study.

A consistent feature in dementia is an overall intellectual deterioration. The present study investigated the intellectual performance of patients with Alzeheimer's disease (AD) and multi-infarct dementia (MID) using the Wechsler Adult Intelligence Scale (WAIS). For reliability and generality purposes two independent samples of patients were collected. Significant differences in Education Level (EDU) and Performance IQ (PIQ) were obtained for the first sample, with the AD group having a significantly higher EDU level. The MID group obtained a higher PIQ. No significant differences were found in the second sample, but EDU level approached significance with the AD group again having a higher EDU level. A discriminant function analysis classified 81% of the patients in the first sample and 100% diagnostic accuracy was obtained for the second sample using the 11 predictor variables. A maximum R2 stepwise regression was performed in order to detect the "best" model of variables discriminating between the diagnostic groups. For the first sample the "best" model was the two variable model, including EDU and Full Scale IQ, accounting for 40% of the variance. The simplest model for the second sample was the one variable model including EDU, accounting for 20% of the variance. Quantitative differences were found between the AD samples. Time since onset of the disease was offered as a possible influence in the quantitative differences in the AD samples. Sampling biases in the behavioral study of dementia are discussed. Successful replication was obtained.

Aged↗
PubMedDate not supplied

Regional cerebral blood flow characteristics of the Sturge-Weber syndrome.

Four patients with the Sturge-Weber syndrome were studied using the non-invasive Xenon-133 inhalation technique. All four patients had decreased regional cerebral blood flow in the area of their lesion, and in two patients who were subsequently tested with 5% carbon dioxide inhalation, impaired vasomotor reactivity was documented. Diminished regional cerebral blood flow is consistent with previously described nuclide flow studies which demonstrated a delay in the initial perfusion blush in the region of the abnormal vasculature. The focal decrease in blood flow was greatest in the most severely affected patient, but was also prominent in the two younger patients, both of whom have excellent neurologic function. These studies suggest that localized decrease in blood flow and vasomotor dysfunction in Sturge-Weber syndrome can precede the occurrence of severe neurologic impairment and extensive cerebral atrophy and possibly be a major contributing factor in progressive dysfunction. A secondary observation was that the blood flow in the unaffected hemisphere was significantly greater in two children compared to the two adults and was similar to the age-related differences reported for normal children and adults.

Adult↗
PubMedDate not supplied

Inhibition of thromboxane A2 production does not improve post-ischemic brain hypoperfusion in the dog.

In a canine model of global brain ischemia, six dogs received a selective thromboxane A2 synthetase inhibitor, UK 38,485 (dazmagrel) before the ischemic event; six received a saline placebo. Cerebral blood flow (CBF), systolic and diastolic arterial pressure, cardiac output, pH, PaCO2, PaO2, and arterial and jugular-vein thromboxane B2 (a stable metabolite of thromboxane A2) and 6-keto PGF1 alpha (a stable metabolite of prostacyclin) were measured at baseline, after release of aortic and venae caval occlusion and at intervals up to 120 min thereafter. Treated animals showed nearly complete post-ischemic inhibition of thromboxane B2 production; control animals showed increases in jugular venous thromboxane B2. Arterial and jugular venous levels of 6-keto PGF1 alpha were significantly higher in treated animals at most post-ischemic intervals. CBF in both groups was similar to baseline values at time 0, then declined similarly in both groups by 30 min to approximately equal to 35% of baseline values where it remained thereafter. There were no significant differences in other variables at any interval. We conclude that inhibition of thromboxane A2 production does not alter post-ischemic brain hypoperfusion.

Animals↗
PubMedDate not supplied

Xenon-133 inhalation method for regional cerebral blood flow measurements: normal values and test-retest results.

The purpose of this investigation is to determine the normal values for regional cerebral blood flow (rCBF) as determined by the xenon inhalation method of Obrist. Normal values for all rCBF parameters were measured in 15 healthy individuals. Our data are compared with the normal data obtained by other investigators. In addition, test-retest rCBF measurements were performed to determine the reproducibility of the method. Our results show that the method is highly reproducible when carried out in serial studies over a short period of time.

Adult↗