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Biomedical subjects

K E Dennis

Publications and source records attributed to K E Dennis.

At least 19 recordsLinked to original sources
PubMed1999

The impact of a shipboard weight control program.

OBJECTIVE: The specific aim was to determine whether a multifaceted approach to weight loss and physical readiness could be implemented onboard a deployed combatant ship of the U.S. Navy. RESEARCH METHODS AND PROCEDURES: Thirty-nine men (31+/-6 years old, mean+/-standard deviation) assigned to the USS ENTERPRISE (CVN 65) during a 6-month Mediterranean deployment who had failed their previous Physical Readiness Test due to excessive body weight (108+/-11 kg overweight) were randomly assigned to nutrition, cognitive-behavioral obesity treatment plus exercise or to the Navy's usual treatment (control), which is exercise alone. RESULTS: Outcomes for the treatment group were significantly better than the controls, with 8.6+/-5.0 vs. 5.0+/-4.1 kg weight loss, 8% vs. 5% reduction in original body weight, and body fat loss of 7% vs. 5%. Triglycerides declined significantly greater in the treatment group than the controls (145 mg/dL to 109 mg/dL vs. 146 mg/dL to 145 mg/dL, p<0.05), whereas depression and eating behaviors significantly improved among treated men. Problematic environmental factors were the limited variety of heart healthy foods in the galley, short meal breaks, and long mess hall lines that led to eating snacks from vending machines and frequent port calls. DISCUSSION: Although greater weight loss than would be expected of a Navy usual care group diluted the treatment effect, the treated men still fared significantly better. The physical readiness implication of this research has the potential to impact Navy health promotion programs and policy, the health and well-being of its personnel, and the Navy's ability to meet mission requirements.

Absorptiometry, Photon↗
PubMed1998

Regional differences in adrenoceptor binding and fat cell lipolysis in obese, postmenopausal women.

In women there is an increase in visceral obesity, subcutaneous abdominal adipocyte lipolysis, and risk of cardiovascular disease (CVD) associated with weight gain after menopause. The mechanisms underlying this increase in adrenoreceptor (AR)-agonist catecholamine-stimulated lipolysis and abdominal obesity in postmenopausal women were studied in intact adipocytes isolated from the abdominal and gluteal subcutaneous fat depots in 19 obese (48% +/- 1% body fat, mean +/- SE) women with a mean +/- SE age of 58 +/- 1 years. The fat cell size and adipose tissue lipoprotein lipase (ATLPL) activity were similar in both sites. The maximal lipolytic responsiveness and sensitivity to isoproterenol were higher (P < .05) in abdominal compared with gluteal adipocytes, but maximal lipolytic response to a post-AR agent was similar. Abdominal adipocytes had a higher beta-AR ([3H]-CGP-12177) and alpha2-AR ([3H]-yohimbine) affinity than gluteal cells (P < .05), lower alpha2-AR density (P < .05), but similar beta-AR density as gluteal cells. Both abdominal and gluteal cell size correlated with alpha2-AR density (P < .01), but not with beta-AR density. Thus, a higher beta-AR affinity and lower alpha2-AR relative to beta-AR density may explain the higher in vitro catecholamine-mediated lipolysis in abdominal compared with gluteal adipocytes in obese, postmenopausal women.

Adipocytes↗
PubMed1998

Aerobic exercise maintains regional bone mineral density during weight loss in postmenopausal women.

This study examines the effects of weight loss by caloric restriction (WL) and aerobic exercise plus weight loss (AEx+WL) on total and regional bone mineral density (BMD) in older women. Healthy, postmenopausal women [age 63 +/- 1 (SE) yr] not on hormone-replacement therapy underwent 6 mo of WL (n = 15) consisting of dietary counseling one time per week with a caloric deficit (250-350 kcal/day) or AEx+WL (n = 15) consisting of treadmill exercise three times per week in addition to the weight loss. Maximal aerobic capacity increased only in the AEx+WL group (P < 0. 001). Body weight, percent fat, and fat mass decreased similarly in both groups (P < 0.005), with no changes in fat-free mass. Total body BMD (by dual-energy X-ray absorptiometry) decreased in both groups (P < 0.05). Femoral neck, Ward's triangle, and greater trochanter BMD decreased in the WL group (P </= 0.05) but were not significantly different after AEx+WL. L2-L4 BMD did not significantly change in either group. Thus WL and AEx+WL both result in losses of total body BMD; however, AEx+WL appears to prevent the loss in regional BMD seen with WL alone in healthy, older women. This suggests that the addition of exercise to weight-loss programs may reduce the risk for bone loss.

Aged↗
PubMed1997

Gender differences in the response of plasma leptin concentrations to weight loss in obese older individuals.

Plasma leptin concentration is directly related to the degree of obesity and is higher in women than in men of the same body mass index (BMI). We hypothesized that fasting plasma leptin concentrations and the response of leptin to weight loss would differ in older men and women of a similar fat mass. Plasma leptin concentrations (radioimmunoassay) and fat mass (DXA) were measured in 47 older, obese (BMI = 30 +/- 4 kg/m2) women and 23 older, obese (BMI = 31 +/- 3 kg/m2) men after a 2 to 4 week period of weight and dietary stabilization, and then in 22 of the women and 18 of the men after a 6-month weight loss intervention (250-350 kcal/d deficit). Leptin correlated with fat mass in men and women (r = 0.75 and r = 0.77, respectively; p values < 0.0001), but women had 3-fold higher leptin levels for a given fat mass than men (p = 0.01). In response to the 6-month hypocaloric diet, men and women lost a similar percentage of fat mass (-13% and -16%, respectively), but the relative decline in circulating leptin was greater in women than men (-45% and -21%, respectively; p < 0.0001). In addition, when leptin was normalized for fat mass using the ratio method, the decrease in leptin per kilogram of fat mass was greater in women than men (-0.37 +/- 0.34 vs. -0.04 +/- 0.06 ng/mL/kg; p < 0.01). After weight loss, the change in leptin concentrations correlated positively with the change in fat mass in men (r = 0.60; p < 0.01), but not in women (r = 0.31; p = 0.17). Furthermore, the loss in fat mass correlated negatively with baseline leptin levels in women (r = -0.47; p < 0.05), but not in men (r = 0.03, p = NS). These results indicate that the decline in leptin concentration with weight loss correlates with the loss in fat mass in men; but, in women, other factors affect the decrease in leptin concentration. This suggests that the role of leptin in the regulation of obesity is gender-specific and may account for gender differences in response to hypocaloric treatment and maintenance of lost weight.

Adipose Tissue↗
PubMed1997

Effects of an American Heart Association diet and weight loss on lipoprotein lipids in obese, postmenopausal women.

The sequential effects of an American Heart Association (AHA) Step 1 diet and subsequent weight loss on lipoprotein lipids in obese [body mass index (in kg/m2) > 27], postmenopausal women (n = 48) were determined. Subjects followed a euenergetic AHA Step 1 diet for 2 mo, followed by a weight-loss diet (deficit of 1.0-1.5 MJ/d) for 6 mo. The AHA diet lowered concentrations of total (7%), low-density-lipoprotein (LDL) (6%), and high-density-lipoprotein (HDL) (14%) cholesterol (P < 0.01). Weight loss (-5.6 +/- 0.7 kg; P < 0.01) increased plasma triacylglycerol concentrations (9%; P < 0.01) and increased HDL-cholesterol concentrations (8%; P < 0.01) compared with changes after the AHA diet, but there were no changes in total or LDL cholesterol. The combined AHA diet and weight-loss interventions lowered triacylglycerol (10%) and total (6%), LDL (6%), and HDL (7%) cholesterol. These changes correlated indirectly with the baseline concentration for each lipid. When the women were divided on the basis of initial LDL-cholesterol concentration, the AHA diet and weight-loss interventions reduced (P < 0.01) triacylglycerol (19%), total cholesterol (13%), and LDL cholesterol (14%) in the women with hypercholesterolemia but not in normocholesterolemic or midly hypercholesterolemic women. Thus, an AHA Step 1 diet and subsequent weight loss improve lipoprotein lipid profiles of obese, postmenopausal women with hypercholesterolemia. However, because it lowers HDL cholesterol, a low-fat diet without substantial weight loss may not be beneficial for improving lipoprotein lipid risk factors for coronary artery disease in obese, postmenopausal women with normal lipid profiles.

American Heart Association↗
PubMed1993

Differential effects of body fatness and body fat distribution on risk factor for cardiovascular disease in women. Impact of weight loss.

This study examines the role of obesity and body fat distribution (ie, waist-to-hip ratio [WHR]) on cardiovascular disease (CVD) risk factors in 50 nondiabetic, obese (body mass index [BMI], 31 +/- 2 kg/m2, mean +/- SD), 45 +/- 10-year-old women. The data obtained at baseline and after weight loss were analyzed after dividing subjects by WHR into upper-body (WHR > 0.80) and lower-body (WHR < or = 0.80) groups and by median-split BMI into more obese (BMI > or = 31) and less obese (BMI < 31) groups. At baseline, the upper-body obese women, when compared with lower-body obese women, had higher plasma triglycerides (TGs) (175 +/- 85 versus 111 +/- 47 mg/dL, respectively; P < .001) and lower high-density lipoprotein cholesterol (HDL-C) (44 +/- 10 versus 54 +/- 11, respectively; P < .01) but similar total and low-density lipoprotein cholesterol levels and blood pressure. There were no significant differences in these CVD risk factors at baseline by BMI split. Although weight loss (-9 +/- 5 kg) lowered blood pressure and TGs irrespective of WHR or BMI, only upper-body obese women raised HDL-C. Moreover, the magnitude of the changes was greatest in women with an upper-body fat distribution. In women with WHR > 0.80, HDL-C increased by 11%, to 49 mg/dL (P < .001), and TGs decreased by 24%, to 134 mg/dL (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1991

Beta-blocker therapy: identification and management of side effects.

The purpose of this study was to develop and test a new beta-Blocker Visual Analog Scale designed to identify and quantify the impact that the side effects of beta-blocker therapy have on people's lives, and the self-management practices people use to mediate their influence. Instruments included the 20-item beta-Blocker Visual Analog Scale and the Profile of Mood States. Subjects had hypertension; 51 men were involved in a larger study involving antihypertensive medications and exercise, and 19 men and women were receiving beta-blocker therapy as first-line drug of choice. Estimates of internal consistency reliability, content validity, and concurrent and discriminant validity were moderately strong. The most problematic side effects were related to lack of sleep, vivid or active dreams, lack of energy and pep, diminished interest in sexual activity, and changes in vision. Among self-management practices used to mediate side effects were planning rest and activity periods, thinking carefully before reacting, and seeking out others for support.

Adaptation, Psychological↗
PubMed1989

Identifying nursing research priorities: a first step in program development.

This study determined nursing research priorities and focused on the development of a nursing research program within a single institution. Of the 715 nurses within the Department of Nursing, 286 (40%) responded to the first round of a two-round Delphi technique, and 137 (48%) responded to the second. The following clinical priorities were determined: prevention and treatment of pressure sores, pain management, treatment of nosocomial infections, and patient education. Nonclinical priorities included staffing and its effects on turnover and patient care, job satisfaction, and factors influencing the quality of nursing care. Serendipitous findings underscored the relevance of the Department of Nursing's conceptual framework to nursing practice and research, revealed the need for dissemination of current research results, and suggested that nurses want to participate in research without assuming responsibility beyond their expertise.

Delphi Technique↗
PubMed1987

The clinical nurse researcher: institutionalizing the role.

The role of the clinical nurse researcher is central to the conduct of clinically relevant research and the integration of research findings into nursing practice, particularly within inpatient settings. Interviews with clinical nurse researchers revealed that implementation of the role occured under four major models: nursing research unit, dual roles, collaborative roles, and functional role division. Organizational and colleague support were critical to the visibility and viability of the clinical nurse researcher role.

Health Facilities↗
PubMed1986

Q methodology: relevance and application to nursing research.

Q methodology is a unique research tradition with an epistemology and technique that is much more than the Q-sort form of instrumentation used to gather data. Developed to explore and understand the richness of human subjectivity, Q methodology, with its emphasis on the individual, is relevant to many substantive areas of scientific inquiry within nursing. This article presents an overview of the technique and delineates special considerations for implementing Q methodological investigations.

Adult↗
PubMed1985

Florence Nightingale: yesterday, today, and tomorrow.

Nurses today continue to incorporate in their practice the insight and foresight of Florence Nightingale, although her clinical acumen and the historical tie are seldom recognized or documented. Qualitative research data that describe good nursing practice from the perspectives of nurses and physicians reflect the relevance and timeliness of Nightingale's century-old yet visionary works to the practice of nursing as it exists in contemporary hospitals. In both eras, the patient is the focal point of nursing care, as nurses concern themselves with disease prevention, health promotion, the physical environment, and psychosocial processes.

Environmental Health↗
PubMedDate not supplied

Optimization of estrogen growth response in MCF-7 cells.

The factors involved in estradiol-17 beta induced growth stimulation of MCF-7 human breast cancer cells have been examined. Wild type MCF-7 cells (and clone E3) were shown to undergo slow growth in phenol-red-free medium containing specific calf sera. The E3 clone was used to document a mean 6-day growth stimulation of 3.35-fold (doubling time = 33 +/- 3 h) in cultures supplemented with 10(-11) M estradiol-17 beta. The serum batch utilized in the culture medium is most important in acquiring significant growth stimulation of MCF-7 cells by estradiol-17 beta. Regardless of the absence of phenol-red, only selected sera (2 out of 14 tested) supported minimal growth of MCF-7 cells in the absence of added estradiol 17 beta (doubling time = 55 +/- 11 h). When a calf-serum-supplemented culture failed to display a complete growth response to estradiol-17 beta, it was due to the rapid growth of the cells in the control (minus estradiol-17 beta) flasks. Sera that promoted shorter doubling times for MCF-7 cells cultured in the absence of estradiol-17 beta were rendered less supportive of growth if treated with dextran-coated charcoal or when cultures were supplemented with the estrogen antagonist ICI 164,384 (10(-7) M). Pooled extracts of these sera were shown to contain stimulatory levels of estradiol-17 beta. Dextran-coated charcoal treatment of sera removed or deactivated factors (other than estradiol-17 beta) which were not only required for the growth of MCF-7 cells, but were necessary for estrogen-stimulated growth. Varying the serum-containing medium, buffer, and nutrient mix or the addition of insulin has no effect on the growth response of these cells to estradiol-17 beta. These investigations document the culture conditions required to produce a maximal and consistent proliferative effect of E2 on MCF-7 cells without exposing the serum constituent to damaging chemical or absorbent agents.

Blood↗