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Biomedical subjects

R L Jensen

Publications and source records attributed to R L Jensen.

At least 91 records · Page 5Linked to original sources
PubMed1981

Changes in left ventricular wall motion after coronary artery bypass surgery: signal or noise?

We evaluated changes in ventricular wall motion after surgery by comparing smoothed, filtered measurements of regional percent shortening (RPS) from right anterior oblique ventriculograms in 37 patients before and after surgery. After surgery there was a significant (p less than 0.05) decrease in the number of regions with hypokinetic wall motion. The distribution of RPS values was also different (p less than 0.005). However, the mean value of RPS for the surgery group as a whole was not significantly altered. These data were contrasted with RPS data from 11 control patients, who were each studied twice but did not have surgical intervention. Similar analysis of the control group did not show any significant change between studies in the number of hypokinetic regions, and the distributions of RPS for the first and second angiograms were not different. We found a 10.3% absolute mean change in repeated measurements of RPS in the control group. We conclude that significant changes occurred after surgery that were not evident in the control group, and the amount of variability in repeated measurements of RPS suggests that analysis should be applied to group rather than individual data.

Coronary Artery Bypass↗
PubMedDate not supplied

Tubercular lymphadenitis: clinical manifestations.

One hundred and thirteen children suffering from tubercular lymphadenitis proven histopathologically, were studied for clinical and laboratory features. Age distribution was equal in all age groups except during infancy when it was rare. Sex ratio indicates a male preponderance with male to female in the ratio of 1.5:1 (67:46). Family history of contact with known tuberculous patient was positive in 19 (17%) children, 44 (40%) had received BCG, and 98 (88%) were either normal nourished or had mild malnutrition. Cervical, axillary and inguinal nodes were found in 90 (80%), 14 (12%), and 8 (7%) children respectively. Epitrochlear node was found in only 1 child. 11 (10%) children had discharging sinus, all being in cervical group. The consistency of nodes was firm in 98 (87%), fluctuation was present in 15 (13%). In 87 (77%) lymph nodes were matted. Hepatomegaly of more than 2 cm was present in 13 (11%) and spleen was enlarged (> 2 cm) in 4 (4%) only: Mantoux test was positive in 96 (85%) children and chest X-ray was abnormal in 25 (22%) cases. Findings suggest that tubercular adenitis occurs in all age groups with equal frequency. It can occur in vaccinated children also. It may be a sole manifestation of tubercular infection. The cervical nodes are predominantly involved. There is no typical location of nodes in individual groups but multiplicity and matting of nodes are characteristic features of tubercular adenitis in children.

Child↗
PubMedDate not supplied

Myocardial bethanidine kinetics after single-dose intravenous infusion: correlation with plasma kinetics in closed-chest dogs.

Myocardial and plasma bethanidine kinetics were determined in five dogs after an intravenous dose of 6 mg/kg/10 min. Serial myocardial drug concentrations were determined from endomyocardial samples obtained by transvenous biopsies between 15 min and 72 h. Tissue and plasma samples were assayed by gas-liquid chromatography. Bethanidine was rapidly concentrated in myocardium within 15 min. Tissue/plasma drug ratios averaged 131 +/- 35 between 15 min and 2 h and 53 +/- 10 between 6 and 48 h. Parallel biexponential decay then occurred for both tissue and plasma compartments; the terminal half-life approximated 16 h. Based on differences in rates of myocardial drug kinetics, the cardiac antifibrillatory effects of bethanidine may occur more rapidly than those of bretylium.

Animals↗
PubMedDate not supplied

Method for estimating confidence levels for measurements by blood glucose monitoring systems.

A joint conference on self-monitoring of blood glucose (SMBG) has proposed that all glucose monitoring systems generate values that are within 10% of the actual blood glucose level 100% of the time. To estimate the confidence limits of blood glucose measurements made in a typical university ambulatory care setting and to ascertain whether they met the proposed standard, we performed duplicate determinations of blood glucose using a reflectance meter and applied to the measurements a method for calculating the closeness of measured values to a "true" mean. Based on paired measurements in 100 consecutive diabetic subjects, we were able to show that one measurement would be within 11.9% of a true mean value 95% of the time and within 8.4% of the mean 90% of the time. The 95 and 90% confidence limits for the average of two repeated measurements were calculated to be 8.4 and 5.9%, respectively. Our methodology can be applied to any set of SMBG values to calculate their confidence limits and to determine whether the measurements meet recommended standards.

Blood Glucose Self-Monitoring↗