Placental transfer of a hydroxylated polychlorinated biphenyl and effects on fetal and maternal thyroid hormone homeostasis in the rat

Earlier studies at our laboratory indicated that several hydroxylated polychlorinated biphenyls (OH-PCBs) detected in human blood could specifically inhibit thyroxine (T4) transport by competitive binding to the thyroid hormone transport protein transthyretin (TTR) in vitro. In the present study we investigated the effects of prenatal exposure to 5 mg/kg body weight of [14C]-labeled or unlabeled 4-OH-2,3,3',4',5-pentachlorobiphenyl (4-OH-CB107), one of the major metabolites of PCBs detected in human blood, from gestation days (GD) 10 to 16 on thyroid hormone status and metabolism in pregnant rats and their fetuses at GD 17 and GD 20. 4-OH-CB107 is a metabolite of both 2,3,3',4,4'-pentachlorobiphenyl (CB-105) and 2,3',4,4',5-pentachlorobiphenyl (CB-118). We were able to show the accumulation of 4-OH-CB107 in the fetal compartment. The fetal/maternal ratios at GD 20 in liver, cerebellum, and plasma were 11.0, 2.6, and 1.2, respectively. The 14C-4-OH-CB107-derived radioactivity in plasma was bound to TTR in both dams and fetuses. Fetal plasma TT4 and FT4 levels were significantly decreased at GD 17 and GD 20 (89 and 41␛espectively at GD 20). Fetal thyroid stimulating hormone levels were increased by 124 at GD 20. The T4 concentrations in fetal forebrain homogenates at GD20 were reduced by 35°but no effects could be detected on brain T3 concentrations. The deiodination of T4 to T3 was significantly increased in fetal forebrain homogenates at GD 17, and unaltered at GD 20. In addition, no alterations were observed in maternal and fetal hepatic T4-UDP-glucuronosyltransferase activity, type I deiodinase activity, and EROD activity. In conclusion, exposure of pregnant rats to 4-OH-CB107 results in the distribution of the compound in the maternal and fetal compartment, which is probably caused by the binding of the PCB metabolite to TTR. Consequently, TT4 levels in fetal plasma and brain samples were reduced. Despite reductions in fetal brain T4 levels, the active hormone (T3) in fetal brains remained unaffected

Peak moments: the experience of coaches

Peak moments are considered by McInman and Grove (1991) to be a global panacea, and include peak experience (Maslow, 1964), peak performance (Privette, 1983) and flow (Csikszentmihalyi, 1990). Peak moments are an under-researched phenomenon in coaching. They could, in principle, be important and motivating experiences, adding a unique and profound richness to the coaching experience. Extant studies focussing on ‘aha’, ‘breakthrough’ and ‘critical moments’ for coachees and coaches discuss the cognitive and not the phenomenological experience. This study aspires to address this gap in the coaching literature. Using a heuristic approach, ten UK coaches with a minimum of eight years’ experience were interviewed about their encounters with peak moments and the interviews were analysed. The findings suggest that peak experience is a rarity in coaching, a transcendental and spontaneous moment of ineffable joy; peak performance validates the coach’s confidence in their skills through feedback from coachees and third parties; and the concept of flow, much discussed in positive psychology, is regularly experienced in coaching, enabling rapport to be strengthened between coach and coachee. The coaches’ feelings, both inside and outside the body, are explored, and findings suggest that the coach becomes a “conduit” in the sense that when coaches draw on their insights, intuition and tacit knowing, a peak moment is more likely to emerge. The analysis in Chapter Five revealed five core conditions which, when applied to coaching, increased the likelihood of the occurrence of a peak moment. In Chapter Six, these conditions are built upon and integrated with the findings from Chapter Four, the role of the coach’s emotions in the coaching dyad. The implications of these findings relate to the joy and engagement of coaching as a vitalising, aesthetic experience, adding richness through the connectedness and collaborative engagement between coach and coachee

CONTROLLED STUDY ON THE COMBINED EFFECT OF ALCOHOL AND TOBACCO SMOKING ON TESTOSTERONE IN ALCOHOL-DEPENDENT MEN

Aims: The present study examined the association between pre-treatment drinking and smoking parameters and plasma testosterone levels before and after alcohol withdrawal. Methods: A total of 51 alcohol-dependent men and 43 age-matched healthy men were investigated. In alcoholics, free testosterone in plasma was measured on the day of admission, after detoxification and after 6 weeks of sobriety. Results: While the testosterone level of alcoholic men did not differ from healthy controls at the onset of withdrawal, it was significantly higher for the alcoholics after 6 weeks of sobriety than for the healthy controls. Higher alcohol consumption and higher tobacco use before detoxification led to higher levels of testosterone concentration before and after withdrawal. Conclusions: The effect of alcohol and tobacco is cumulative, with higher levels of alcohol and tobacco consumption being associated with higher levels of testosterone before and after alcohol withdrawa

Oral cancer trends in a single head-and-neck cancer center in the Netherlands; decline in T-stage at the time of admission

Objectives: In this study we evaluated the possible epidemiologic changes of oral cancer patients in the Netherlands between the years 1980-1984 and 2000-2004. We specifically studied the differences in male-female ratio, age, TNM-stage, site distribution, and alcohol and tobacco use. Materials and Methods: Patients from the VU University Medical Center with an oral squamous cell carcinoma of the oral cavity registered in 1980-1984 (n=200), group 1, were compared to patients registered in 2000-2004 (n=184), group 2. Trends in prevalence, site distribution, TNM-stage, alcohol and tobacco use, age and gender were studied. Results: The male-female ratio has decreased from 1.8 to 1.2. There were no differences in age between the two groups of patients. The site distribution was similar in both groups. The most commonly involved sites were the tongue and the floor of mouth. In group 2 more patients were diagnosed with a T1 tumour. There were no differences in tobacco use between the two different groups. There were much more light drinkers (0-2 drinks per day) in group 2 than in group 1, whereas there were more heavy drinkers (>4 per day) in group 1 than in group 2 (p<0.001). This was observed in both male and female patients. Conclusion: In our study there were no significant differences between the patients registered in the years 1980-1984 and 2000-2004 regarding the mean age of the patients, site distribution and smoking habits. The male-female ratio has decreased. In the recent group more patients were staged T1N0 and there was a strong decrease of the patients who were heavy drinkers. © Medicina Oral S. L

A superconducting transformer system for high current cable testing

This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10 464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples