Biological Research For Nursing

Harrell, Joanne S. ;Bomar, Perri ;McMurray, Robert ;Bradley, Chyrise ;Deng, Shibing

doi: 10.1177/109980040200300201pmid: 11931523

Defects in the leptin gene or the leptin receptor may be a genetic cause of obesity, but little is known about the familial associations of leptin and obesity. This study compared plasma leptin and measures of obesity in a sample of 248 subjects (124 mother-offspring pairs); 34% were African American and 66% were white. Youth were aged 12 to 16 years. Plasma leptin and body mass index (BMI) were higher in mothers than in their offspring and, among the offspring, higher in girls than boys, even after correcting for BMI or body fat. Racial differences in leptin were present in both mothers and youth when adjusting for percentage body fat but disappeared when adjusting for BMI. In univariate analyses of the associations between mothers and offspring, BMI was associated with leptin in all groups but was most strongly associated in white pairs and in mother-son pairs. In multiple regression analyses, when adjusting for BMI, significant predictors of leptin level for the boys and girls together were gender, BMI, and pubertal status of the offspring; in girls only BMI was significant (R2= 0.72), and in boys the significant predictors were their BMI (R2= 0.66) followed by their pubertal status (R2= 0.06) and the leptin level of their mothers (R2= 0.02). When adjusting for body fat, the predictors were the offspring’s percentage body fat (R2=0.67) and mother’s leptin (R2= 0.03), with similar results in gender-specific analyses. The authors conclude that leptin levels of youth are most closely associated with their degree of obesity or body fat; mother’s leptin and, for boys only, pubertal status also play a small role. Although the small association between maternal leptin on leptin in their offspring could be due to either heredity or shared environment, the results of this study suggest that individual obesity and environmental factors are important predictors of leptin levels in children.

Wung, Shu-Fen

doi: 10.1177/109980040200300202pmid: 11931524

Continuous ST-segment monitoring has been used to detect acute myocardial ischemia, determine the success of the reperfusion therapy, and predict outcomes in both research and a variety of clinical settings. However, analyzing the abundant electrocardiography (ECG) data recorded using continuous multilead ST-segment monitoring techniques is time consuming and requires expertise. Experienced data interpreters in dedicated ECG core laboratories handle many continuous ECG data records fromlar ge clinical trials. Little information on measurement issues for computer-assisted ST-segment analysis is available for individual investigators. Unsupervised or inexperienced computer analysis of ST-segment deviations can, under certain circumstances, yield invalid or unreliable summary indices. The goal of this article is to discuss basic ST-segment measurement principles in evaluating acute myocardial ischemia and methodological issues surrounding the use of computerassisted ST-segment analysis for continuous ECG data. Variables affecting ST-segment measurements will be examined. Sources and examples of variability for these potential errors will be identified.

Washington, Eric A.

doi: 10.1177/109980040200300203pmid: 11931525

Patients with indwelling catheters acquire urinary tract infections at a rate of5% per day. After 30 days of catheterization, there is a 78% to 95% incidence of bacteriuria, despite the use of meticulous catheter care. Research studies on reducing the development of bacteriuria have focused on the propagation of bacteria within the catheter drainage bag. This research proposal sought to determine the effects of instillation of 3% hydrogen peroxide versus distilled vinegar in urethral catheter drainage bags to decrease bacteriuria in 20 long-termcatheterized patients. Baseline urine cultures for control and test mediums showed no significant difference in rates of bacteriuria. However, urine cultures obtained at the 48-hour interval showed significant reduction in bacteriuria in urinary bags irrigated with vinegar. The implications this study has for nursing practice include a need for further research using a larger number of subjects and a need for improvements in the design of the catheter drainage system.

Ojala, Beth E. ;Page, Leslie A. ;Moore, Marjorie A. ;Thompson, LaDora V.

doi: 10.1177/109980040200300204pmid: 11931526

The purpose of this study was to determine the effects of inactivity on lactate dehydrogenase (LDH) enzyme activity (expressed in nmol/ g dry weight hour) in single skeletal muscle fibers from the soleus muscle in adult and aged rats. Fourteen 12-month-old and fifteen 30-month-old Fisher 344 Brown Norway F1 Hybrid rats were randomly assigned to control, 1 week of hindlimb unweighting (HU1), or 2 weeks of hindlimb unweighting (HU2). With age, a significant decrease in LDH enzyme activity occurred in type I skeletal muscle fibers (29.5%, P < 0.05). Following HU2, individual type I skeletal muscle fibers from the 12-month-old animals showed a 33.3% increase in LDH activity. In contrast, individual type I fibers from the aged animals showed a 50.0% increase after HU1. In conclusion, the baseline levels of LDH activity were significantly less in aged versus adult rats. The timing of the skeletal muscle adaptation to inactivity was different between young and old animals, such that the older animals responded to inactivity before the younger animals. These biochemical changes may have an impact on the fatigability of the muscle following inactivity. The findings indicate that treatment during bed rest for the older adult may be different than that for the younger adult.

doi: 10.1177/109980040200300205pmid: N/A