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Background and purpose: Female sex hormones may protect pre-menopausal women from sudden cardiac death. We therefore investigated the effects of the main female sex hormone, 17β-estradiol, on ischaemia-induced cardiac arrhythmias and on the L-type Ca2+ current (ICaL). Experimental approach: In vivo experiments were performed in pentobarbital-anaesthetized rats subjected to acute coronary artery occlusion. ICaL was measured by the whole-cell patch-clamp technique, in rat isolated ventricular myocytes. Key results: Acute intravenous administration of 17β-estradiol as a bolus dose followed by a continuous infusion, commencing 10 min before coronary artery occlusion, had dose-dependent antiarrhythmic activity. In female rats 300 ng kg-1 + 30 ng kg-1 min-1 17β-estradiol significantly reduced the number of ventricular premature beats (VPBs) and the incidence of ventricular fibrillation (VF). A ten fold higher dose of 17β-estradiol was required to cause similar effects in male rats. In vitro 17β-estradiol reduced peak ICaL in a concentration-dependent manner. The EC50 was ten-fold higher in male myocytes (0.66 μM) than in females (0.06 μM). Conclusions and implications: These results indicate that 17β-estradiol has marked dose-dependent antiarrhythmic activity that is greater in female rats than in males. A similar differential potency in blocking ICaL in myocytes from female and male rats can account for this effect. This provides an explanation for the antiarrhythmic activity of 17β-estradiol and gender-selective protection against sudden cardiac death. [ABSTRACT FROM AUTHOR]

BACKGROUND: A variety of demographic and clinical variables are acknowledged as risk factors for delirium; a syndrome thought to be mediated by abnormalities in a wide range of neurotransmitters. However, little research has been conducted in this field and the role of neuro-immunological factors as a mechanism of medication has received very little attention. AIMS: To determine if low base line (on admission) IGF-1 levels (a protective cytokine released by brain cells in response to insult) is a risk factor for incident delirium in patients aged 75 and over admitted to an acute medical ward. METHOD: Base line demographic and clinical variables and serum IGF-1 levels were measured in a consecutive series of 100 non-delirious subjects on inpatient admission. Subjects were assessed daily regarding the development of delirium during the inpatient episode. RESULTS: Twelve patients developed incident delirium. IGF-1 (OR: 0.822, CI: 0.69, 0.97, p = 0.027), pre-admission cognitive deterioration (assessed by IQCODE) (OR; 3.26, CI: 1.18, 9.04, p = 0.023) and depression (GDS four item: cut-off score > or = 3) (OR; 8.99, CI 1.59,50.76, p = 0.013) were identified as risk factors for developing subsequent delirium. CONCLUSIONS: Despite the small size of this study our findings suggest that low, pre-morbid IGF-1 is a risk factor for subsequent delirium in this population, emphasizing the potential protective role of this anabolic cytokine and the need for replication of these findings. [ABSTRACT FROM AUTHOR]

The prospective controlled study investigated the concentrations of free beta-human chorionic gonadotrophin (HCG) subunit in 554 women with a singleton intrauterine or tubal pregnancy. They presented with vaginal bleeding and/or abdominal pain in the first 18 weeks of pregnancy. The control group comprised 156 women with musculoskeletal pain and no vaginal bleeding. Their pregnancies continued to term. The study group comprised 398 women (141 threatened-continuing pregnancies, 37 threatened-miscarriages, 185 non-continuing pregnancies and 35 tubal pregnancies). Free beta-HCG concentrations were significantly lower in the non-continuing, threatened-miscarriage and tubal pregnancy groups [mean 4.62, 6.50 and 4.27 ng/ml respectively; 95% confidence interval (CI) 3.75-5.69, 4.46-9.48 and 2.92-6.2 respectively] than in the control and threatened-continuing groups (mean 41.61 and 48.22 ng/ml respectively; 95% CI 34.53-50.13 and 42.03-55.32 respectively) (P < 0.001 in all cases). A cut-off value at 20 ng/ml was found to differentiate between the 'viable' (control and threatened-continuing) and the 'abnormal' (non-continuing, threatened-miscarriage and tubal) pregnancies, with 88.3% sensitivity and 82.6% positive predictive value. An excellent diagnostic and prognostic usability of free beta HCG was confirmed by a receiver operating characteristic curve plot. In conclusion, a single serum free beta-HCG measurement taken in early pregnancy is valuable in the immediate diagnosis of early pregnancy failure and the long-term prognosis of viability. [ABSTRACT FROM AUTHOR]

This prospective controlled study investigated the concentrations of free β-human chorionic gonadotrophin (HCG) subunit in 554 women with a singleton intrauterine or tubal pregnancy. They presented with vaginal bleeding and/or abdominal pain in the first 18 weeks of pregnancy. The control group comprised 156 women with musculo-skeletal pain and no vaginal bleeding. Their pregnancies continued to term. The study group comprised 398 women (141 threatened-continuing pregnancies, 37 threatened-miscarriages, 185 non-continuing pregnancies and 35 tubal pregnancies). Free β-HCG concentrations were significantly lower in the non-continuing, threatened-miscarriage and tubal pregnancy groups [mean 4.62, 6.50 and 4.27 ng/ml respectively; 95% confidence interval (CI) 3.75–-5.69, 4.46–9.48 and 2.92–6.2 respectively] than in the control and threatened-continuing groups (mean 41.61 and 48.22 ng/ml respectively; 95% CI 34.53–50.13 and 42.03–55.32 respectively) (P < 0.001 in all cases). A cut-off value at 20 ng/ml was found to differentiate between the ‘viable’ (control and threatened-continuing) and the ‘abnormal’ (non-continuing, threatened-miscarriage and tubal) pregnancies, with 88.3% sensitivity and 82.6% positive predictive value. An excellent diagnostic and prognostic usability of free βHCG was confirmed by a receiver operating characteristic curve plot In conclusion, a single serum free β-HCG measurement taken in early pregnancy is valuable in the immediate diagnosis of early pregnancy failure and the long-term prognosis of viability. [ABSTRACT FROM PUBLISHER]