Using a tobit regression model to analyse risk factors for foot-pad dermatitis in commercially grown broilers

A model was developed to explain the influence of different local and regional factors on the prevalence of foot-pad dermatitis in broilers at the time of slaughter. Data from a recent two-year study of broiler foot-health in Sweden were used to construct the model. The model was based on regression analysis, using a Tobit model for censored data. This type of Tobit regression model has been used for several decades in econometrics and can also be found in the medical-scientific literature. It has, however, reportedly not been used in veterinary medicine although there appears to be several situations where it should be considered useful. Week of slaughter was significantly (p < 0.001) associated with total foot-pad score, which decreased over time. The birds' age at slaughter was also significantly (p < 0.01) associated with total foot-pad score. Five out of the 11 slaughterhouses included in the study were included as significant (p < 0.01) variables in the final model. Three feed suppliers (p < 0.05) and four regions (p < 0.01) were also included as significant variables in the model. There were also significant (p < 0.001) interactions between several of these factors (mainly, between the time variable and specific slaughterhouses, feed suppliers or regions, respectively). The information gathered in this study regarding the influence of a number of risk factors for the development of foot-pad dermatitis and their reciprocal interactions will enable us to modify the Swedish broiler foot-health programme.     

Activity of D-glucarate analogues: synergistic antiproliferative effects with retinoid in cultured human mammary tumor cells appear to specifically require the D-glucarate structure

D-Glucarate has shown modest chemopreventive and synergistic chemopreventive effects with retinoids in a number of tumor models as well as a similar antiproliferative effect in MCF-7 human tumor cells in culture. It has been postulated that D-glucarate exerts some of its effects by equilibrium conversion to D-glucarolactone, a potent beta-glucuronidase inhibitor. In the present study, D-glucarate and a number of its analogues, including D-glucarolactone, were evaluated as antiproliferatives in the MCF-7 model with and without added retinoid. Results suggest that the effects of glucarate are reasonably specific for its structure and may not require conversion to glucarolactone.     

Opioid requirements and responses in Asians

BACKGROUND: There is a relationship between stressful situations and the susceptibility towards certain diseases, probably mediated by immune system modifications. AIM: To study T lymphocyte proliferation in medical students during periods of differing academic stress. SUBJECTS AND METHODS: Blood samples were obtained from 42 medical students during a period of moderate academic stress, immediately before a final examination and after their summer vacations. T lymphocyte proliferation in response to 5, 10 and 20 mg/ml phytohemagglutinin was measured by the incorporation of 3H-thymidine, and plasma cortisol was measured by RIA. RESULTS: T lymphocyte stimulation index in response to all phytohemagglutinin concentrations was significatively lower in the period before examination than in the other two periods. There were no differences in the index between the period of moderate stress and after summer vacations. Plasma cortisol levels were 15.6 +/- 4.3, 18.6 +/- 5.8 and 16.7 +/- 5.1 mg/dl during the periods of moderate stress, before the examination and after vacations, respectively (p < 0.05 for the difference between examination and the other two periods). CONCLUSIONS: There is a decrease in lymphocyte proliferation and an increase in cortisol levels during a period of acute academic stress in medical students, suggesting that, the exposure of the healthy subjects to common stressful stimuli, may affect their immunocompetance.     

Drugs in salmonid aquaculture--a review

In contrast to mammalian therapeutics, the use of pharmaceutical substances is rather limited in fish. It is basically restricted to anaesthetic agents and anti-infective agents for parasitic and microbial diseases. Anaesthetic agents are used primarily in fish farm and laboratory settings to provide analgesia and immobilization of fish for minor procedures. The anti-infective agents are used for controlling diseases and the choice of drug depends on efficacy, ease of application, human safety, target animal safety including stress to the fish, environmental impact, regulatory approval, costs, and implications for marketing the fish. In this article, the major drugs used in salmonids in North America and Europe will be reviewed and some insight into future directions for drug development and use for the salmonid industry will be introduced. The mechanisms of action, pharmacokinetics, side effects, and uses of the drugs are emphasized.