DIRECT EFFECT OF MELATONIN UPON THE RELEASE OF GONADOTROPINS FROM THE SUPERFUSED PITUITARY GLAND OF THE MALE GOLDEN HAMSTER

The pineal gland is known to be light sensitive and to be involved in the seasonal reproduction of male golden hamster Mesocricetus auratus. In general, the pineal gland has been demonstrated to be inhibitory to the reproductive system of the male golden hamster. Melatonin is a pineal hormone which can mimic the action of the pineal gland upon the reproductive system. However, the actual site(s) of melatonin action in the hamster has not been demonstrated. In this study a direct effect of melatonin on the release of FSH and LH from superfused hamster pituitary glands was investigated.^ The superfused pituitary glands showed a stable in vitro basal release of FSH and LH for up to 10 hours. The superfused pituitaries demonstrated reproducible responses to repeated pulses of 10('-8) M LHRH, and a dose-dependent response to stimulation with different concentrations of LHRH.^ Melatonin inhibited the basal release of FSH and LH from superfused hamster pituitary glands. This effect of melatonin was specific and not a general indolamine or catecholamine effect.^ The superfused pituitaries had a diurnal differential responsiveness to physiological concentrations of melatonin with respect to FSH and LH release which were related to the light cycle used to maintain the experimental animals. A LD 14:10 photoperiod cycle was used with light on from 5 a.m. till 7 p.m.. With pituitary glands obtained at 8:30 a.m., the basal release of FSH exhibited an initial inhibition, a gradual rebound at approximately two hours after the beginning of melatonin superfusion, and a significant overshoot of FSH release after the cessation of infusion with melatonin (Morning Response). If the pituitary glands were obtained from hamsters which were sacrificed at 3:30 p.m., the release rate of FSH exhibited an inhibition during the entire period of melatonin infusion with a rebound effect appearing only after melatonin infusion was discontinued (Afternoon Response). There was no significant difference in the responsiveness of the pituitary gland to infusion with melatonin at either 8:30 a.m. or 3:30 p.m. with respect to LH release. Also, melatonin could not inhibit the gonadotropins response to continuous superfusion with 10('-9) M LHRH in pituitaries obtained at either 8:30 a.m. or 3:30 p.m., nor inhibit the stimulatory effect of pulsatile 10('-9) M LHRH. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI^

A process evaluation of a health literacy intervention targeting pediatric providers' communication skills at the Texas Children's Health Plan

Background. Health literacy is an important determinant for quality health care, and affects communication between patients and physicians. Poor communication may result in negative effects in health. Improved communication between patients and physicians could positively affect health outcomes. Communication skills are teachable.^ Objectives. (1) to evaluate the process involved in the design and implementation of a health literacy intervention targeting pediatric providers’ communication skills at the Texas Children’s Health Plan in Houston, Texas; and (2) to describe lessons learned from this process that may be used in future attempts to address the issue of health literacy and health communication. ^ Design/methods. The process evaluation of the implementation of a health literacy strategy at the Texas Children’s Health Plan (TCHP) consisted of a critical analysis of all documents and minutes from meetings of the team of investigators. It also involved a secondary analysis of data collected between December 2006 and June 2007. Descriptive statistics, paired t-test and Wilcoxon-signed-rank test were employed in analyzing the data. This information was complemented with a limited review of existing literature on communication skills training programs. ^ Results. The design of the educational intervention followed recommendations from experts in the field of health literacy. The delivery of the intervention was possible and benefited from existing resources and logistics within the TCHP. Very few targeted providers participated in two offerings of the workshop (6.6% and 1.7% respectively). After the educational intervention, providers showed increased knowledge of health literacy facts and its effects in health (p=0.001); increased awareness of the low health literacy problem (p=0.003); increased expectations for change in practice (p=0.002), and intent to use health literacy strategies for communication immediately following the intervention (p=0.001). Low participation indicated the need for further investigation of barriers to, and means for successful implementation of programs aimed to improving health communication. ^ Conclusions. A short, focused intervention utilizing health literacy strategies for communication appeared effective in increasing knowledge and intentions for change in a small group of pediatric providers. ^

Cost-effectiveness analysis of a 2-stage community-based hepatocellular carcinoma screening program in Taiwan

Hepatocellular carcinoma (HCC) has been ranked as the top cause of death due to neoplasm malignancy in Taiwan for years. The high incidence of HCC in Taiwan is primarily attributed to high prevalence of hepatitis viral infection. Screening the subjects with liver cirrhosis for HCC was widely recommended by many previous studies. The latest practice guideline for management of HCC released by the American Association for the Study of Liver Disease (AASLD) in 2005 recommended that the high risk groups, including cirrhotic patients, chronic HBV/HCV carriers, and subjects with family history of HCC and etc., should undergo surveillance.^ This study aims to investigate (1) whether the HCC screening program can prolong survival period of the high risk group, (2) what is the incremental cost-effectiveness ratio of the HCC screening program in Taiwan, as compared with a non-screening strategy from the payer perspective, (3) which high risk group has the lowest ICER for the HCC screening program from the insurer's perspective, in comparison with no screening strategy of each group, and (4) the estimated total cost of providing the HCC screening program to all high risk groups.^ The high risk subjects in the study were identified from the communities with high prevalence of hepatitis viral infection and classified into three groups (cirrhosis group, early cirrhosis group, and no cirrhosis group) at different levels of risk to HCC by status of liver disease at the time of enrollment. The repeated ultrasound screenings at an interval of 3, 6, and 12 months were applied to cirrhosis group, early cirrhosis group, and no cirrhosis group, respectively. The Markov-based decision model was constructed to simulate progression of HCC and to estimate the ICER for each group of subjects.^ The screening group had longer survival in the statistical results and the model outcomes. Owing to the low HCC incidence rate in the community-based screening program, screening services only have limited effect on survival of the screening group. The incremental cost-effectiveness ratio of the HCC screening program was $3834 per year of life saved, in comparison with the non-screening strategy. The estimated total cost of each group from the screening model over 13.5 years approximately consumes 0.13%, 1.06%, and 0.71% of total amount of adjusted National Health Expenditure from Jan 1992 to Jun 2005. ^ The subjects at high risk of developing HCC to undergo repeated ultrasound screenings had longer survival than those without screening, but screening was not the only factor to cause longer survival in the screening group. The incremental cost-effectiveness ratio of the 2-stage community-based HCC screening program in Taiwan was small. The HCC screening program was worthy of investment in Taiwan. In comparison with early cirrhosis group and no cirrhosis group, cirrhosis group has the lowest ICER when the screening period is less than 19 years. The estimated total cost of providing the HCC screening program to all high risk groups consumes approximately 1.90% of total amount of adjusted 13.5-year NHE in Taiwan.^

SOCIO-ENVIRONMENTAL FACTORS ASSOCIATED WITH THE DISTRIBUTION OF DRACUNCULUS MEDINENSIS (GUINEA WORM DISEASE) AND SUGGESTED METHODS FOR CONTROL, IBARAPA, NIGERIA, 1982 (AFRICA)

A population-based cross-sectional survey of socio-environmental factors associated with the prevalence of Dracunculus medinensis (guinea worm disease) was conducted in Idere, a rural agricultural community in Ibarapa, Oyo state, Nigeria, during 1982.^ The epidemiologic data were collected by household interview of all 501 households. The environmental data were collected by analysis of water samples collected from all domestic water sources and rainfall records.^ The specific objectives of this research were to: (a) Describe the prevalence of guinea worm disease in Idere during 1982 by age, sex, area of residence, drinking water source, religion and weekly amount of money spent by the household to collect potable drinking water. (b) Compare the characteristics of cases with non-cases of guinea worm in order to identify factors associated with high risk of infection. (c) Investigate domestic water sources for the distribution of Cyclops. (d) Determine the extent of potable water shortage with a view to identifying factors responsible for such shortage in the community. (e) Describe the effects of guinea worm on school attendance during 1980/1982 school years by class and location of school from piped water supply.^ The findings of this research indicate that during 1982, 31.8 percent of Idere's 6,527 residents experienced guinea worm infection, with higher prevalence of infection recorded in males in their most productive years and females in their teenage years. The role of sex and age to risk of higher infection rate was explained in the context of water related exposure and water intake due to dehydration from physical occupational actitives of subgroups.^ Potable water available to residents was considerably below the minimum recommended by WHO for tropical climates, with sixty-eight percent of water needs of the residents coming from unprotected surface water which harbour Cyclops, the obligatory intermediate host of Dracunculus medinensis. An association was found between periods of relative high density of Cyclops in domestic water and rainfall.^ Impact of guinea worm infection on educational activities was considerable and its implications were discussed, including the implications of the research findings in relation to control of guinea worm disease in Ibarapa. ^

Relationships of impulsivity and physical fighting history to alcohol -induced aggression in women

Research suggests women respond to the aggression-inducing effects of alcohol in a manner similar to men. Highly aggressive men are more prone to alcohol-induced aggression, but this relationship is less clear for women. This study examined whether alcohol consumption would differentially affect laboratory-measured aggression in a sample of aggressive and non-aggressive women and how those differences might be related to components of impulsive behavior. In 39 women recruited from the community (two groups: with and without histories of physical fighting) ages 21–40, laboratory aggressive behavior was assessed following placebo and 0.80 g/kg alcohol consumption (all women experienced both conditions). Baseline laboratory impulsive behavior of three impulsivity models was later assessed in the same women. In the aggression model (PSAP), participants were provoked by periodic subtractions of money, which were blamed on a fictitious partner. Aggression was operationalized as the responses the participant made to subtract money from that partner. The three components of impulsivity that were tested included: (1) response initiation (IMT/DMT), premature responses made prior to the completion of stimulus processing, (2) response inhibition (GoStop), a failure to inhibit an already initiated response, and (3) consequence sensitivity (SKIP and TCIP), the choice for a smaller-sooner reward over a larger-later reward. I hypothesized that, compared to women with no history of physical fighting, women with a history of physical fighting would exhibit higher rates of alcohol-induced laboratory aggression and higher rates of baseline impulsive responding (particularly for the IMT/DMT), which would also be related to the alcohol-induced increases aggression. Consistent with studies in men, the aggressive women showed strong associations between laboratory aggression and self-report measures, while the non-aggressive women did not. However, unlike men, following alcohol consumption it was the non-aggressive women's laboratory aggression that was related to their self-reports of aggression and impulsivity. Additionally, response initiation measures of impulsivity distinguished the two groups, while response inhibition and consequence sensitivity measures did not; commission error rates on the IMT/DMT were higher in the aggressive women compared to the non-aggressive women. Regression analyses of the behavioral measures showed no relationship between the aggression and impulsivity performance of the two groups. These results suggest that the behavioral (and potentially biological) mechanism underlying aggressive behavior of women is different than that of men. ^