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L Joy

Publications and source records attributed to L Joy.

10 recordsLinked to original sources
PubMed1996

Randomized study of right ventricular function with intermittent warm or cold cardioplegia.

BACKGROUND: Transient right ventricular dysfunction has been previously documented after bypass operations despite adequate myocardial protection with intermittent antegrade cold blood cardioplegia. Recently warm blood cardioplegia has been interrupted during construction of distal anastomoses to improve visualization. The effects of intermittent antegrade warm blood cardioplegia, and the resultant periods of right ventricular normothermic ischemia, on postoperative right ventricular function are unknown. METHODS: To assess the effects of cardioplegia on right ventricular protection, 52 patients undergoing isolated bypass grafting were randomized to intermittent warm or cold blood cardioplegia. The two groups were similar with respect to age, sex, ventricular function, and right coronary stenoses. Cross-clamp times were similar (warm, 64 +/- 22 minutes; cold, 63 +/- 15 minutes; not significant). The cumulative time of cardioplegia interruption was longer in the cold group (42 +/- 8 minutes) than in the warm group (31 +/- 14 minutes; p < 0.002). A rapid-response thermodilution catheter was employed to assess postoperative right ventricular ejection fraction and end-diastolic and end-systolic volume indices. RESULTS: The right ventricular ejection fraction was greater in the warm group at 6 hours (warm, 0.46 +/- 0.06; cold, 0.37 +/- 0.08; p < 0.05) and 8 hours (warm, 0.43 +/- 0.08; cold, 0.37 +/- 0.08; p < 0.05) postoperatively. The right ventricular end-diastolic volume index was less in the warm group 8 hours postoperatively (warm, 83 +/- 11 mL/m2; cold, 94 +/- 16 mL/m2; p < 0.05). There were no differences in pulmonary arterial pressures or right ventricular stroke work index. CONCLUSIONS: Despite intermittent normothermic ischemia of half the cross-clamp time, patients receiving warm cardioplegia maintained right ventricular hemodynamics after bypass grafting.

Aged↗
PubMed1993

Repeatability of energy expenditure measurements in clinically normal dogs by use of indirect calorimetry.

Energy expenditure (EE) was determined, using an open-flow indirect calorimetry system in a group of 20 clinically normal, apparently resting, client-owned dogs. Five evaluations were performed over an 8-hour period to determine reliability of the method. The intraclass correlation coefficient was calculated as the ratio of within- and between-subject variances, using repeated-measures ANOVA. When only the middle 3 evaluations were included, the intraclass correlation coefficient was 0.87, indicating good reliability. The first evaluation was higher than the subsequent 4 evaluations for rate of O2 consumption (Vo2/kg and Vo2/kg0.75; (P < or = 0.01), and EE/kg and EE/kg0.75 (P < or = 0.005). The respiratory quotients at the first (P = 0.004) and second (P = 0.013) evaluations were different from the respiratory quotient at the fourth evaluation. Therefore, the first evaluation may not be representative of the actual EE. The mean value of at least 3 subsequent evaluations after an adequate adaptation period (5 to 10 minutes) to the equipment will be useful for predicting energy requirements of apparently resting, clinically normal dogs.

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PubMedDate not supplied

Macrophage oxidation of low density lipoprotein generates a modified form recognized by the scavenger receptor.

Incubation of low density lipoprotein (LDL) with endothelial cells or smooth muscle cells overnight has resulted in an oxidative modification of LDL that results in its recognition by macrophages by way of the acetyl LDL receptor. In the present study, we examined whether macrophages themselves can oxidize and modify LDL in a manner similar to that of endothelial cells. Incubation of 125I-labeled LDL with resident or thioglycollate-elicited macrophages for 24 hours in Ham's F-10 medium resulted in the appearance of thiobarbituric acid (TBA) reactive materials and trichloroacetic acid (TCA) soluble radioactivity in the medium. The LDL harvested from these incubations showed increased electrophoretic mobility and was degraded rapidly when added to fresh macrophages as compared to LDL previously incubated in the absence of cells. These macrophage-induced modifications could be prevented if the first incubation was carried out in the presence of the antioxidant butylated hydroxytoluene (BHT) or in Dulbecco's modified Eagle's medium (DMEM). The degradation of 125I-labeled macrophage-modified LDL by macrophages was competitively inhibited by unlabeled acetyl LDL or unlabeled endothelial cell-modified LDL but not by native LDL, indicating that the degradation was mediated by the acetyl LDL receptor.

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PubMedDate not supplied

Networking: a managerial strategy for research development in a service setting.

An innovative managerial strategy--networking--used to establish and promote a nursing research program within three teaching hospitals in Boston is outlined in this article. Networking provides an opportunity for research and program development experts to share resources to meet common needs and goals. One of the advantages of a research network is that it can provide educational offerings that will stimulate all levels of professional nursing staff independent of their research background. Results of a survey the network conducted to determine a citywide profile of nursing research needs are presented.

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