Human selenium status and glutathione peroxidase activity in north-west England

Nutritional selenium deficiency disease, due to low soil selenium content, is well recognized in British livestock. The adequacy of the selenium status of 25 healthy human volunteers, 50 blood donors, 94 general medical patients and 106 allergy clinic patients was investigated in 1987/8 by measuring serum selenium concentration and platelet glutathione peroxidase activity. Mean serum selenium concentration for the entire study population was 92 micrograms/l. Significant linear correlations between serum selenium concentration and peroxidase activity indicate that a substantial proportion of both healthy volunteers and medical patients are of low selenium nutritional status. Twenty-five per cent of healthy volunteers and 50 per cent of medical patients had serum selenium values below those required for full expression of selenium-dependent enzyme activity. Deficiency of the antioxidant activities of selenium and selenium-dependent enzymes may be relevant to geographical differences in morbidity from a wide range of human disease states.     

APPROACHES TO PROMOTING MORE WIDESPREAD PARTICIPATION IN PHYSICAL ACTIVITY

Exercise is associated with a reduced risk of coronary heart disease, has beneficial effects on cardiovascular risk factors, and has other health benefits. No more than 10 per cent to 20 per cent of adults in Australia and other developed countries participate in regular vigorous physical activity, while over 65 per cent of Australian adults are almost totally sedentary. Survey data from the U.S.A. suggest that levels of participation in jogging and walking have increased in the past 10 years but that the proportion of people who take no deliberate exercise has also increased. Large-scale community interventions to promote exercising have not been subject to rigorous evaluation and it is difficult to reach any firm conclusions about the effects of exercise promotion. However, it is possible to identify some of the factors which may influence exercise participation, and there is information from trials of large-scale, multifactorial interventions to reduce cardiovascular risk which provides some helpful guidelines about how it may be useful to proceed. Approaches to increasing levels of exercise participation should emphasise community-based efforts which provide appropriate settings and social support for exercising, making exercise a more appealing and accessible option for large numbers of people; the use of mass media for community education about exercising should be co-ordinated carefully with specific community activities. Personalized fitness instruction, groups and classes should place more emphasis on exercise as a pattern of behaviour to be integrated into a person's way of life and maintained over time; and there is the potential for more widespread and systematic use of self-instructional exercise materials to assist people who wish to exercise independently. Because there exist only limited local research findings and work in other countries does not yet provide conclusive information, research and development priorities for these areas are suggested.     

Ampicillin-Sulbactam versus Cefoxitin for Prophylaxis in High-Risk Patients Undergoing Abdominal Surgery

This double-blind study compared ampicillin-sulbactam 3 g versus cefoxitin 2 g in 136 adult patients at risk for developing an infection after abdominal surgery. Separate randomization schedules were used for colorectal, upper gastrointestinal/biliary, and other abdominal procedures. Study antibiotics were administered within 30 minutes before incision and repeated 6 hours later. Patients having colorectal surgery received a third dose of antibiotic 6 hours after the second. Efficacy evaluations were made on 123 patients, 62 in the ampicillin-sulbactam group and 61 in the cefoxitin group. The overall postoperative infection rates were 12.9% for ampicillin-sulbactam and 9.8% for cefoxitin (p>0.05); one wound infection occurred in each group. Adverse events were experienced by 13.2% of the ampicillin-sulbactam and 19.1% of the cefoxitin recipients (p>0.05). Cost-minimization analysis revealed that ampicillin-sulbactam was a cost-effective alternative to cefoxitin for the prevention of infection after abdominal surgery.     

Morphine Enhances Pharmacological Preconditioning by Isoflurane: Role of Mitochondrial KATP Channels and Opioid Receptors

Background: Adenosine triphosphate-regulated potassium channels mediate protection against myocardial infarction produced by volatile anesthetics and opioids. We tested the hypothesis that morphine enhances the protective effect of isoflurane by activating mitochondrial adenosine triphosphate-regulated potassium channels and opioid receptors.

Methods: Barbiturate-anesthetized rats (n = 131) were instrumented for measurement of hemodynamics and subjected to a 30 min coronary artery occlusion followed by 2 h of reperfusion. Myocardial infarct size was determined using triphenyltetrazolium staining. Rats were randomly assigned to receive 0.9% saline, isoflurane (0.5 and 1.0 minimum alveolar concentration [MAC]), morphine (0.1 and 0.3 mg/kg), or morphine (0.3 mg/kg) plus isoflurane (1.0 MAC). Isoflurane was administered for 30 min and discontinued 15 min before coronary occlusion. In eight additional groups of experiments, rats received 5-hydroxydecanoic acid (5-HD; 10 mg/kg) or naloxone (6 mg/kg) in the presence or absence of isoflurane, morphine, and morphine plus isoflurane.

Results: Isoflurane (1.0 MAC) and morphine (0.3 mg/kg) reduced infarct size (41 +/- 3%; n = 13 and 38 +/- 2% of the area at risk; n = 10, respectively) as compared to control experiments (59 +/- 2%; n = 10). Morphine plus isoflurane further decreased infarct size to 26 +/- 3% (n = 11). 5-HD and naloxone alone did not affect infarct size, but abolished cardioprotection produced by isoflurane, morphine, and morphine plus isoflurane.     

Comparative study of four wound dressings on epithelization of partial-thickness wounds in pigs

Sixteen shallow wounds were inflicted in each of five Yorkshire white female piglets, 18-20 kg body weight, by a 2-cm diameter, fast-rotating abrasive disc. The injury is similar to a second-degree burn. The wounds were dressed with one of four dressings: Duoderm (Squibb), Op-Site (Smith & Nephew) [corrected], and collagen sponge, covered with either occlusive or semiocclusive polyurethane film (Datascope Corp.). The last two dressings were moistened with saline before application. The rate of epithelization by planimetric quantitation after 3 to 5 days was the same regardless of the dressing used, although the epithelium layer was thicker in wounds treated with Duoderm. Wounds dressed by either of the collagen sponge materials showed a better appearance when visually scored. Wounds dressed with Duoderm or Op-Site were often macerated; Duoderm's paste-like material remained on the wound and was difficult to remove without inflicting discomfort to the patient. Duoderm, and also Op-Site, adhered much more strongly to the intact skin than either type of collagen sponge dressing.