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Biomedical subjects

G S Cowan

Publications and source records attributed to G S Cowan.

At least 19 recordsLinked to original sources
PubMed2001

Influence of body fat distribution on oxygen uptake and pulmonary performance in morbidly obese females during exercise.

OBJECTIVE: The aim of this study was to determine the effects of fat distribution on aerobic and ventilatory response to exercise testing in morbidly obese (MO) females. METHODOLOGY: The study population consisted of 164 MO females, 55% (n = 90) with upper body or abdominal adiposity (UBD), as defined by waist-hip circumference ratio (WHR) > or = 0.80, and 45% (n = 74) with lower body fat distribution (LBD) (WHR < 0.80). An incremental exercise testing on cycle ergometer was performed to determine the effect of exercise on oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), tidal volume (VT), respiratory rate (fb) and heart rate (HR). RESULTS: Upper body adiposity individuals had significantly higher VO2 and VCO2 than LBD subjects (P < 0.05) from 0 watt (W) of pedalling up to their anaerobic threshold (AT) and maximal exercise. VE was significantly higher in UBD subjects compared with LBD subjects, from 20 W during exercise up to AT and peak work levels (P < 0.05). Upper body adiposity group also had a significantly higher fb than the LBD group at rest, after each workload and at AT and peak exercise work rates (P < 0.05). VT was lower in UBD subjects at free pedalling and up to AT and peak workload with significant difference at 60 and 80 W (P < 0.05). The anaerobic threshold, expressed as work rate, was significantly lower in the UBD subjects (P < 0.05) and peak workload achieved did not differ significantly between the two groups. CONCLUSIONS: Upper body adiposity subjects had higher oxygen requirement, more rapid and shallow breathing, higher ventilatory demand, but lower anaerobic threshold than the LBD individuals during progressive exercise. It suggests that the cardiopulmonary endurance to exercise in MO patients with upper body fat distribution is lower than in those with lower body fat distribution.

Adipose Tissue↗
PubMed2001

Stimulation of leptin release by arachidonic acid and prostaglandin E(2) in adipose tissue from obese humans.

The purpose of this study was to examine the effect of arachidonic acid and its metabolites on leptin formation by explants of human adipose tissue over a 48-hour incubation in primary culture. We found that arachidonic acid or prostaglandin E(2) (PGE(2)) stimulated leptin release by explants of subcutaneous adipose tissue from obese humans. The stimulatory effect of arachidonic acid on leptin formation was blocked by NS-398, a cyclooxygenase-2 (COX-2) inhibitor. There was appreciable release of PGE(2) to the medium over 48 hours, and this was inhibited by 99% in the presence of 200 nmol/L dexamethasone or 5 micromol/L NS-398. The increase in PGE(2) release correlated with induction of COX-2 activity during the 48-hour incubation. The increase in COX-2 activity was blocked by 200nmol/L dexamethasone. The level of leptin mRNA at 48 hours was reduced by 28% if PGE(2) was added in the absence of dexamethasone, while in the presence of dexamethasone, the amount of leptin mRNA was enhanced by 156%. These data suggest that when upregulation of COX-2 is blocked by dexamethasone, exogenous PGE(2) enhances both leptin release and leptin mRNA accumulation by explants of human adipose tissue in primary culture.

Adipose Tissue↗
PubMed2001

Assessment of the effects of a taped cognitive behavior message on postoperative complications (therapeutic suggestions under anesthesia).

BACKGROUND: The authors studied whether playing a taped cognitive-behavior message during and immediately following bariatric surgery will improve performance of a postoperative regimen designed to enhance recovery. METHODS: The double-blinded placebo-controlled study consisted of 27 morbidly obese bariatric surgical patients randomly assigned to listen to either a blank (Controls) or a positive therapeutic message audiotape (Tape). A Postoperative Regimen Checklist (PRC) quantified different parts of the postoperative recovery regimen. RESULTS: The data showed that patients in the Tape group, compared to the Controls: 1) achieved better scores at most PRC assessment points (p < 0.05), 2) required less encouragement to perform tasks (p < 0.05), and 3) were discharged from the hospital a mean of 1.6 days earlier. CONCLUSIONS: A taped cognitive-behavioral message, played to patients repetitively during and immediately following bariatric surgery, is effective in enhancing postoperative compliance and reducing in-patient length of stay.

Adult↗
PubMed2000

Regulation of leptin release by troglitazone in human adipose tissue.

In pieces of human subcutaneous adipose tissue incubated in primary culture for 48 hours, the release of leptin was stimulated by 50% in the presence of 3.3 micromol/L troglitazone. Insulin (0.1 nmol/L) and dexamethasone (200 nmol/L) stimulated leptin release by 30% and 300%, respectively. Troglitazone in combination with either insulin or dexamethasone had no effect on leptin release. Instead, troglitazone inhibited leptin release in the presence of both dexamethasone and insulin. The stimulatory effect of troglitazone on leptin release was also mimicked by 1 micromol/L 15-deoxy-delta(12-14)prostaglandin J2 (dPGJ2). However, if the concentration of dPGJ2 was increased to 10 micromol/L in the presence of dexamethasone, there was a decrease in leptin release, as well as of lactate formation and lipolysis. These data indicate that both stimulatory and inhibitory effects of troglitazone and dPGJ2 can be seen on leptin release by human adipose tissue.

Adipose Tissue↗
PubMed2000

Synergism between insulin and low concentrations of isoproterenol in the stimulation of leptin release by cultured human adipose tissue.

The release of leptin by pieces of human adipose tissue incubated in primary culture for 24 or 48 hours in the presence of dexamethasone was reduced by isoproterenol. An inhibition of leptin release was observed at 24 hours in the presence of isoproterenol and was mediated by beta1-adrenergic receptors, since it was blocked by the specific beta1-adrenoceptor antagonist CGP-20712A. The inhibitory effect of 33 nmol/L isoproterenol on leptin release was reversed in the presence of 0.1 nmol/L insulin to a 2-fold stimulation of leptin release. These data suggest that the primary mechanism by which insulin stimulates leptin release is to blunt the inhibitory effects of beta1-adrenergic receptor agonists, and low concentrations of catecholamines actually enhance the stimulation of leptin release by insulin.

Adipocytes↗
PubMed2000

Intravenous immunoglobulin therapy for children with Stevens-Johnson syndrome.

OBJECTIVE: To review the experience with intravenous immunoglobulin (IVIG) therapy in patients with Stevens-Johnson syndrome (SJS) in our institution. METHODS: All charts of patients with SJS admitted to Children's Hospital between November 1988 and June 1998 were reviewed. RESULTS: Twelve patients with SJS were detected. There were 8 males and 4 females, with a mean age 6 years (range 10 mo to 17 yrs). All patients presented with high fever and cutaneous and mucous membrane changes, and the diagnosis SJS was confirmed by a dermatologist. Of the 12 patients with SJS, 7 were treated with IVIG, 2 with corticosteroids, and 3 with supportive care. IVIG was administered in a single infusion at 1.5-2 g/kg, and was given on an average of hospital day 3 (range 1-8 days). The average duration of fever was 8 days (range 3-14) in the IVIG treated patients compared to 14 days (range 6-20) in the non-IVIG treated group (p = 0.06). The mean hospital stay was 12 days (range 4-22) for the patients treated with IVIG and 15 days (range 6-25) for the non-IVIG treated group (p = 0.5). No toxicity was observed with IVIG therapy. CONCLUSION: Duration of fever was shortened in patients treated with IVIG, although statistical significance was marginal. The hospital stay was slightly shortened in patients treated with IVIG; however, statistical significance was not reached. Prospective and controlled, multicenter studies are needed to further investigate these preliminary findings.

Adolescent↗
PubMed1999

Criteria for selection of patients for bariatric surgery.

International criteria for bariatric surgery and bariatric surgeons have been well-defined in terms of the current state of the art and are presented together with weight tables and a list of co-morbidities of morbid obesity. The bariatric surgeon should make the primary judgement concerning bariatric surgery using these criteria as guidelines only, not strict rules; others who use these criteria should govern themselves in a like, fair-minded, fashion. Medical insurers' and their agents' criteria, if excessively restrictive relative to the guidelines, may reflect an ingrained prejudice against the morbidly obese, manifesting itself in an unfair, unethical and immoral bias. It is the essence of humane and equitable behaviour on the part of all concerned that the morbidly obese receive non-discriminatory, appropriate treatment, care and medical insurer coverage for their disease and its comorbidities.

Body Weight↗
PubMed1998

Significant changes in blood pressure, glucose, and lipids with gastric bypass surgery.

The morbidly obese have a disproportionately greater risk of hypertension, diabetes, and coronary artery disease than their lean or less seriously obese counterparts. Roux-en-Y gastric bypass surgery has been found to be highly effective in inducing, and sustaining, weight loss in individuals with morbid obesity. The purpose of the present study was to examine the effects of weight loss with Roux-en-Y gastric bypass surgery (GBP) on blood pressure, fasting blood glucose, and the lipid/lipoprotein status of 61 morbidly obese women and 21 men. Anthropometric and blood pressure assessments and blood samples for glucose and lipid/lipoprotein analyses were obtained before surgery and at 6 to 12 months postoperatively. By this time, morbidly obese (MO) males and females had lost 33% and 30% of their initial body weight, respectively, along with significant reductions in fasting blood glucose (p < 0.01) and systemic blood pressure (p < 0.05). Weight loss with GBP was also associated with significant reductions in the apoprotein B-containing lipoproteins and the triglyceride and cholesterol composition of these particles. There was a trend (p < 0.10) toward increased serum levels of high density lipoprotein (HDL)-cholesterol following GBP, and significant (p < 0.05) improvement in HDL subfraction distribution and composition. These findings demonstrate the effectiveness of GBP in inducing metabolic changes in the MO population, which may reduce the risk of coronary artery disease, diabetes, and hypertension.

Adult↗
PubMed1998

What do patients, families and society expect from the bariatric surgeon?

The expectations of patients, their families and society of the bariatric surgeon are often unrealistic, but for different reasons. The morbidly obese patient often expects 'everything' from bariatric surgery. The patient's family is frequently ambivalent. Society, on the other hand, tends to unrealistically regard the morbidly obese as billboards advertising them as willful deviants whose problems can all be resolved by 'just pushing away from the table'. This invalid stereotype has prompted some to incorrectly regard bariatric surgery as an undeserved reward for individuals who will not control their own behavior. The undeserved intentional deviant status of the morbidly obese causes members of society to harass, mock or otherwise mistreat this subpopulation. Society's harmful, destructive and unjust weight harassment 'fat-ism' has made the morbidly obese modern day moral equivalents of lepers. We conclude that society must be persuaded to accept weight harassment as 'politically incorrect', subject to the same consequences as any other form of bigotry. Once society regards the morbidly obese as victims, not perpetrators, of their nonsurgically curable disease, bariatric surgery results should become held to similar standards as surgery for carcinoma, cardiovascular and other diseases. Until then, the morbidly obese remain the last true bastion of prejudice.

Attitude↗
PubMed1997

Infant botulism.

Explore the source record for details and available documents.

Botulism↗
PubMed1991

A nutrition support team quality assurance plan.

The Nutrition Support Team at the Veterans Affairs Medical Center is responsible for the development of guidelines related to the provision of both total parenteral nutrition and enteral nutrition support. A Quality Assurance plan which was approved by the Joint Commission on Accreditation of HealthCare Organizations was implemented by the Nutrition Support Team. This plan addresses: nutritional assessment and consultation, indications for enteral and parenteral nutrition support, provision of optimal nutrition support including attainment of nutritional goals, and the prevention, detection, and management of complications. The indicators and criteria for each aspect of care are described. This program has provided documentation of the activities of the Nutrition Support Team as well as data defining the patient population requiring specialized nutrition support, and has helped identify areas where improvement is required.

Dietary Services↗