Relationship between the energy status of Daphnia magna and its sensitivity to environmental stress

This work tested the hypothesis that animals with a high energy status are more successful in dealing with stress than animals with a low energy status. Daphnids (Daphnia magna) were reared for 2 weeks in four different concentrations of food. Survival was not affected by food supply, and growth and reproduction increased with increasing food ration. This increase correlated well with the energy status, as was measured by scope for growth on day 15. After 2 weeks, the daphnids in the four different food ration groups were exposed for another 2 weeks to a range of increased salinities or cadmium concentrations, while remaining in their respective food concentrations. In the salinity groups, survival, growth, or reproduction were not influenced at low salinities. Exposure to higher salinity significantly decreased survival and reproduction, but this decrease was more pronounced in the highest food concentrations. In the cadmium exposed daphnids, cadmium content increased with increasing exposure concentrations, but accumulation was independent of food rations. Cadmium exposure significantly decreased survival, growth, and reproduction and this decrease again was more pronounced with increasing food concentration. Thus, the high energy status of the daphnids from the high food concentrations at the start of the exposure did not provide an increased capacity to cope with additional stress. Instead, the sensitivity of the daphnids to stress increased with increasing food ration. This increased sensitivity is likely to be the result of a change in life history from emphasizing survival at low food supply to stressing reproduction at high food supply.     

Cancer screening among Native Americans in eastern North Carolina

The purpose of the study is to explore cancer screening predictors and practices among Lumbee Indians in eastern North Carolina. Interviewers from the community conducted phone interviews with 333 men and 456 women aged 40 and older randomly selected from the Lumbee Tribal roll as part of the Lumbee Diabetes and Health Survey. The survey has sections on demographic information and health conditions, family history of chronic conditions, and health behaviors. This paper reports on cancer screening behaviors. Rates of ever being screened for breast, cervical, prostate and colon cancer were relatively high compared with overall national rates. Predictors included younger age, better health, more education, and lifestyle factors such as engaging in regular physical activity and not smoking. Future research should focus on developing culturally appropriate campaigns to increase the frequency of cancer screening to conform to guidelines, and educational programs and interventions to reach Lumbee Indians most at risk for not being screened.     

Degree of Sedation Obtained with Various Doses of Diazepam and Nitrazepam

Abstract Using critical flicker fusion (CFF)determination and estimation of drowsiness in eight healthy volunteers the sedative-hypnotic effects of diazepam and nitrazepam were studied. Three dose levels of each drug were used, so that dose-effect curves could be produced. The most reliable results were obtained with the CFF method, and significant dose-effect relations could be demonstrated. The CFF deviation after diazepam initially related well to the concentration in blood serum, but after 4–6 hours the CFF depression vanished rapidly, while the drug concentration remained high. After nitrazepam the signs of drowsiness occurred similarly, while the drug concentration in serum showed on an average a slower rise. The effects began to disappear before the nitrazepam concentration had reached a peak. A rapid tachyphylaxis at the receptor sites seems to be responsible for this incongruity. Nitrazepam exerted significantly stronger sedative effects than diazepam, particularly when the respective serum concentrations were taken into account. This confirms that nitrazepam should be a more efficient sleeping drug, although diazepam also has considerable sedative-hypnotic action.     

Preventive foot-care practices among adults with diabetes in North Carolina, 1997 to 2001

Preventive foot-care practices, such as annual foot examinations by a health-care provider, can substantially reduce the risk of lower-extremity amputations. We examined the level of preventive foot-care practices (reported rates of having at least one foot examination by a physician) among patients with diabetes mellitus in North Carolina and determined the factors associated with these practices. Of 1,245 adult respondents to the 1997 to 2001 North Carolina Behavioral Risk Factor Surveillance System, 71.6% reported that they had had their feet examined within the past year, a rate that is much higher than that previously reported by Bell and colleagues in the same population for 1994 to 1995 (61.7%). Foot care was more common among insulin users than nonusers, those having diabetes for 20 years or longer than those having diabetes for less than 10 years, blacks than whites, and those who self-monitored their blood glucose level daily than those who did not. The results of this study indicate that diabetes educational services can be directed at populations at high risk of ignoring the recommended foot-care practices indicated in these analyses, thereby reducing diabetes-related lower-extremity complications.     

Invasive cutaneous malignant melanoma in Sweden, 1990-1999. A prospective, population-based study of survival and prognostic factors

BACKGROUND: The objective of the current study was to compile prospective, population-based data on cutaneous invasive melanomas in Sweden during the period from 1990 to 1999, to describe and analyze survival data and prognostic factors, and to make comparisons with previously published Swedish and international data. METHODS: Twelve thousand five hundred thirty-three patients, which included 97% of all registered melanomas in Sweden, were included and described. Among these, 9515 patients with clinical Stage I and II melanoma were included in an analysis of survival and in a univariate analysis, and 6191 patients were included in a multivariate analysis of prognostic factors. RESULTS: There was no significant change in melanoma incidence during 1990-1999. Favorable prognostic factors were found, especially in younger and female patients, resulting in a relative 5-year survival rate of 91.5%. In the multivariate analysis, significant factors that had a negative effect on survival were Clark level of invasion, Breslow thickness, ulceration, older patient age, trunk location, greatest tumor dimension, nodular histogenetic type, and male gender. CONCLUSIONS: During the period from 1990 to 1999, the 5-year survival of patients with malignant melanoma in Sweden was better compared with the previously reported rates in published, population-based studies from Sweden, probably as a result of better secondary prevention due to better knowledge and awareness by both patients and the medical profession. The more favorable prognostic factors and the change in melanoma location found in younger patients, compared with earlier reports, may reflect changes in clothing as well as tanning habits; however, a decrease also was found in Clark Level II and thin melanomas for the same patient group. The authors concluded that further improvements can be achieved with better access to health care and with the use of early melanoma detection campaigns.     

Effects of patient and health-system characteristics on community tenure of discharged psychiatric inpatients

OBJECTIVE: The purpose of this study was to identify the differential effect of patient and health-system characteristics on length of stay in the community among recidivist psychiatric patients. METHODS: Data on demographic and clinical characteristics and mental health service utilization were collected for patients with at least one previous psychiatric hospitalization (N=1,972) who visited a psychiatric emergency department at a university hospital in Leuven, Belgium, between March 2000 and March 2002. Logistic regression analysis was used to compare the characteristics of patients with a short (less than two months), intermediate (two to 12 months), or long (12 months or longer) stay in the community between their last hospital discharge and referral to the psychiatric emergency department. RESULTS: One in three patients visited the psychiatric emergency department within 30 days of discharge from a psychiatric hospitalization, and 43 percent of the patients visited within 60 days of discharge. Patients with a short community stay were more likely to be unemployed and to have had a discharge against medical advice, a short previous hospitalization, no aftercare plan, and a history of two or more previous hospitalizations. Longer community stays were predicted by the presence of a personality disorder. CONCLUSIONS: For patients with a history of psychiatric hospitalization, early psychiatric recidivism may be more highly influenced by health-system characteristics than by the presence of severe mental illness.     

Is insulin sensitivity a causal intermediate in the relationship between alcohol consumption and carotid atherosclerosis?: the insulin resistance and atherosclerosis study

OBJECTIVE: A J-shaped association has been demonstrated between alcohol consumption and atherosclerosis. Insulin resistance, also a risk factor for atherosclerosis, has been shown to have a similar J-shaped association with alcohol intake. This raises the question of whether insulin sensitivity (S(I)) is a causal intermediate in the alcohol-atherosclerosis relationship. RESEARCH DESIGN AND METHODS: The Insulin Resistance Atherosclerosis Study was a multicenter cohort study designed to investigate relationships among S(I), risk factors for cardiovascular disease, and carotid artery atherosclerosis. Using regression analysis, we tested whether adjustment for S(I) attenuated the alcohol-atherosclerosis relationship observed at baseline. RESULTS: A J-shaped association was observed between alcohol consumption and common carotid artery intimal medial thickness. The protective aspect of the alcohol-atherosclerosis relationship was attenuated by 25% after the adjustment for S(I). However, an interaction was observed between alcohol consumption and glucose tolerance (GT) status. In comparison with never drinkers, all levels of alcohol consumption were associated with less atherosclerosis in participants with normal GT status. Participants with impaired GT status (but not diabetes) demonstrated a J-shaped alcohol-atherosclerosis association. All levels of alcohol consumption were associated with more atherosclerosis in participants with diabetes. CONCLUSIONS: S(I) may be a causal intermediate at protective levels of alcohol intake, but an alcohol-GT interaction precluded a definitive conclusion. Moderate alcohol consumption may increase the risk of atherosclerosis in people with diabetes. These findings contrast with previous reports and do not support current recommendations regarding moderate alcohol consumption in people with diabetes. More research is needed to clarify this issue.