Oestrogen confers cardioprotection by suppressing Ca2+/calmodulin-dependent protein kinase II

BACKGROUND AND PURPOSE

Oestrogen confers cardioprotection by down-regulating the beta(1)-adrenoceptor and suppressing the expression and activity of protein kinase A. We hypothesized that oestrogen may also protect the heart by suppressing Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), another signalling messenger activated by the beta(1)-adrenoceptor, that enhances apoptosis.

EXPERIMENTAL APPROACH

We first determined the expression of CaMKII in the heart from sham and ovariectomized rats with and without oestrogen replacement. We then determined the effects of CaMKII inhibition (KN93, 2.5 micromolxL(-1)) in the presence or absence of 10(-7) molxL(-1) isoprenaline, a non-selective beta-adrenoceptor agonist. We also determined the percentage apoptosis in myocytes from rats in each group with or without beta-adrenoceptor stimulation.

KEY RESULTS

Both CaMKIIdelta and phosphorylated CaMKII were up-regulated in the hearts from ovariectomized rats, and they were restored to normal by oestrogen replacement. The infarct size and lactate dehydrogenase release were significantly greater after ovariectomy. Similarly, cardiac contractility, the amplitude of the electrically induced intracellular Ca(2+) transient and the number of apoptotic cells were also greater in ovariectomized rats upon ischaemia/reperfusion in the presence or absence of isoprenaline. Most importantly, the responses to ischaemic insult in ovariectomized rats were reversed not only by oestrogen replacement, but by blockade of CaMKII with KN93.

CONCLUSIONS AND IMPLICATIONS

Oestrogen confers cardioprotection at least partly by suppressing CaMKIIdelta. This effect of oestrogen on CaMKII is independent of the beta-adrenoceptor and occurs in addition to down-regulation of the receptor.

Factors associated with bed and room sharing in Chinese school-aged children

BACKGROUND AND OBJECTIVES

Co-sleeping (bed or room sharing) has potential implications for children's development. Previous studies showed that co-sleeping was more prevalent in non-Western countries than in Western countries, which demonstrated that co-sleeping was marked with ethnic and socio-cultural background characteristics. The purpose of this study was to survey the prevalence of bed and room sharing and to examine related factors among school-aged children in an Asian country - China.

METHODS

A cross-sectional questionnaire survey was conducted in 10 districts of Shanghai, China from November to December 2005. A total of 4108 elementary school children, 49.2% boys and 50.8% girls with a mean age of 8.79 years, participated. Parent-administered questionnaires were used to collect information about children's sleeping arrangements and socio-demographic characteristics.

RESULTS

The prevalence of routine bed sharing, room sharing and sleeping alone in Chinese school-aged children was 21.0%, 19.1% and 47.7%, respectively. Bed and room sharing didn't show significant gender difference but gradually decreased with increasing age. Multivariate logistic regression identified those factors associated with bed and room sharing: younger age, large family, children without their own bedroom and parents' approval of a co-sleeping arrangement.

CONCLUSION

Co-sleeping arrangement was a common practice in Chinese school-aged children. Associated factors were characterized by intrinsic socio-cultural values and socio-economic status in China.

Efficient human growth hormone gene expression in the milk of non-transgenic goats

Heterogenous expression of recombinant proteins in milk of livestock at a large scale is very labour-intensive to be achieved with current transgenic animals, and usually seen as time-consuming, expensive and technically most challenging. Here we describe a convenient system for transient production of recombinant human growth hormone and its extensive use in recombinant protein production for therapeutic purposes. In this study, an adenoviral vector containing the GFP gene and hGH gene was constructed for direct infusion into the epithelium of mammary glands of goats via the teat canal during the period of natural lactation. Western-blot analysis of milk samples obtained from all of the viral-treated founders indicated that the recombinant hGH (rhGH) was secreted into the milk of the goats. The concentrations of rhGH in milk ranged from 0.6 to 2.4 mg/ml and lasted for more than 10 days during lactation. These data suggest that it is possible to produce larger amounts of recombinant human growth hormone in the milk of livestock animals by using replication-defective adenoviruses.

Efficacy, safety and tolerability of rivastigmine capsules in patients with probable vascular dementia: the VantagE study

OBJECTIVE

The aim was to evaluate the efficacy, safety and tolerability of rivastigmine capsules in patients diagnosed with probable vascular dementia (VaD).

METHODS

VantagE (Vascular Dementia trial studying Exelon) was a 24-week, multicentre, double-blind study. VaD patients aged 50-85 years were randomized to rivastigmine capsules (3-12 mg/day) or placebo. Efficacy assessments included global and cognitive performances, activities of daily living and neuropsychiatric symptoms. Adverse events were recorded. Additional exploratory analyses determined whether heterogeneity in pathologies and symptoms extended to differential treatment effects.

TRIAL REGISTRATION

NCT00099216.

RESULTS

710 patients were randomized. Rivastigmine demonstrated superiority over placebo on three measures of cognitive performance (Vascular Dementia Assessment Scale, Alzheimer's Disease Assessment Scale cognitive subscale, Mini-Mental State Examination; all p< or = 0.05, intent-to-treat population [ITT]), but not other outcomes. Predominant adverse events were nausea and vomiting. Exploratory analyses indicated that older patients (> or =75 years old), assumed more likely to also have Alzheimer's disease (AD) pathology, demonstrated significant cognitive responses to rivastigmine and a safety profile similar to that seen in AD patients. Younger patients, assumed less likely to have concomitant AD pathology, showed no efficacy response and were associated with slight elevations of blood pressure, cerebrovascular accidents and mortality. Rivastigmine-placebo differences in patients with, versus those without, medial temporal atrophy (also suggestive of concomitant AD) showed a numerical difference similar to that seen between the older versus younger patients, but did not attain statistical significance.

CONCLUSION

Consistent with trials evaluating other cholinesterase inhibitors, rivastigmine did not provide consistent efficacy in probable VaD. The efficacy apparent on cognitive outcomes was derived from effects in older patients likely to have concomitant Alzheimer pathology. This is supportive of an existing argument that the putative cholinergic deficit in VaD reflects the presence of concomitant Alzheimer pathology.

It takes a village to prevent falls: reconceptualizing fall prevention and management for older adults

Systematic evidence reviews support the efficacy of physical activity programs and multifactorial strategies for fall prevention. However, community settings in which fall prevention programs occur often differ substantially from the research settings in which efficacy was first demonstrated. Because of these differences, alternative approaches are needed to judge the adequacy of fall prevention activities occurring as part of standard medical care or community efforts. This paper uses the World Health Organization Innovative Care for Chronic Conditions (ICCC) framework to rethink how fall prevention programs might be implemented routinely in both medical and community settings. Examples of innovative programs and policies that provide fall prevention strategies consistent with the ICCC framework are highlighted, and evidence where available is provided on the effects of these strategies on processes and outcomes of care. Finally, a "no wrong door" approach to fall prevention and management is proposed, in which older adults who are found to be at risk of falls in either a medical or community setting are linked to a standard fall risk evaluation across three domains (physical activity, medical risks, and home safety).

Composite tissue transplantation: a rapidly advancing field

Composite tissue allotransplantation (CTA) is emerging as a potential treatment for complex tissue defects. It is currently being performed with increasing frequency in the clinic. The feasibility of the procedure has been confirmed through 30 hand transplantation, 3 facial reconstructions, and vascularized knee, esophageal, and tracheal allografts. A major drawback for CTA is the requirement for lifelong immunosuppression. The toxicity of these agents has limited the widespread application of CTA. Methods to reduce or eliminate the requirement for immunosuppression and promote CTA acceptance would represent a significant step forward in the field. Multiple studies suggest that mixed chimerism established by bone marrow transplantation promotes tolerance resulting in allograft acceptance. This overview focuses on the history and the exponentially expanding applications of the new frontier in CTA transplantation: immunology associated with CTA; preclinical animal models of CTA; clinical experience with CTA; and advances in mixed chimerism-induced tolerance in CTA. Additionally, some important hurdles that must be overcome in using bone marrow chimerism to induce tolerance to CTA are also discussed.

Using data on resistance prevalence per sample in the surveillance of antimicrobial resistance

OBJECTIVES

In most existing antimicrobial resistance monitoring programmes, one single bacterial colony from each collected sample is susceptibility tested against a panel of antimicrobials. Detecting the proportion of colonies resistant to different antimicrobials in each sample can provide quantitative data on antimicrobial resistance (resistance prevalence per sample).

METHODS

In this study, a total of 98 faecal samples from slaughter pigs were tested for tetracycline and sulphonamide resistance in Escherichia coli using the single colony method, and these results were compared with the results obtained using the resistance prevalence per sample method.

RESULTS

The results obtained by the resistance prevalence per sample method showed a lower occurrence of resistance. Tetracycline resistance in E. coli was found in 36.7% of the samples using the single colony method, while the mean tetracycline resistance prevalence was 22.5% using the resistance prevalence per sample method. Similarly, sulphonamide resistance was 32.7% using the single colony method and 19.6% when using the resistance prevalence per sample method. Although different estimates were obtained by each method, the correlation test and the regression model demonstrated that there is a significant association between the results obtained using both methods (P value <0.01) for both antimicrobials tested.

CONCLUSIONS

To support risk assessment and analysis of the association between consumption of antimicrobials and occurrence of resistance, there is a need to move towards a more quantitative approach when dealing with antimicrobial resistance in a population, and the resistance prevalence per sample method can provide some of this additional information.