HOTAIR lifts noncoding RNAs to new levels

It is not clear to what extent noncoding RNAs regulate the homeobox (HOX) genes that encode key regulators of development in the embryo. In this issue, Rinn et al. (2007) characterize noncoding RNAs that regulate HOX genes and discover one, HOTAIR, that unexpectedly regulates a HOX gene cluster on a different chromosome than the HOX cluster that encodes it.     

Role of interleukin-4 in regulation of age-related inflammatory changes in the hippocampus

It is well documented that long term potentiation (LTP) is impaired in the hippocampus of the aged animal. Among the changes that contribute to this impairment is an increase in hippocampal concentration of the pro-inflammatory cytokine interleukin-1beta (IL-1beta), and increased IL-1beta-induced signaling. In this study we investigated the possibility that these changes were a consequence of decreased concentration of the anti-inflammatory cytokine, IL-4, and decreased IL-4-stimulated signaling. We report that functional IL-4 receptors are expressed on granule cells of the dentate gyrus and that receptor activation results in phosphorylation of JAK1 and STAT6. Hippocampal IL-4 concentration was decreased with age, and this was accompanied by a decrease in phosphorylation of JAK1 and STAT6. The evidence indicates that IL-4 modulates expression of IL-1beta mRNA and protein and that it attenuates IL-1beta-induced impairment of LTP and phosphorylation of JNK and c-Jun. We argued that, if a decrease in hippocampal IL-4 concentration significantly contributed to the age-related impairment in LTP, then restoration of IL-4 should restore LTP. To test this, we treated rats with VP015 (phospholipid microparticles-incorporating phosphatidylserine), which increases IL-4 concentration in hippocampus. The data indicate that the VP015-induced increase in IL-4 concentration in hippocampus of aged rats and lipopolysaccharide (LPS)-treated rats was accompanied by a reversal of the age-related and LPS-induced impairment in LTP in perforant path granule cell synapses. We propose that interplay between pro-inflammatory and anti-inflammatory responses impact significantly on synaptic function in the hippocampus of the aged rat.     

Lung heparan sulfates modulate K(fc) during increased vascular pressure: evidence for glycocalyx-mediated mechanotransduction

Lung endothelial cells respond to changes in vascular pressure through mechanotransduction pathways that alter barrier function via non-Starling mechanism(s). Components of the endothelial glycocalyx have been shown to participate in mechanotransduction in vitro and in systemic vessels, but the glycocalyx's role in mechanosensing and pulmonary barrier function has not been characterized. Mechanotransduction pathways may represent novel targets for therapeutic intervention during states of elevated pulmonary pressure such as acute heart failure, fluid overload, and mechanical ventilation. Our objective was to assess the effects of increasing vascular pressure on whole lung filtration coefficient (K(fc)) and characterize the role of endothelial heparan sulfates in mediating mechanotransduction and associated increases in K(fc). Isolated perfused rat lung preparation was used to measure K(fc) in response to changes in vascular pressure in combination with superimposed changes in airway pressure. The roles of heparan sulfates, nitric oxide, and reactive oxygen species were investigated. Increases in capillary pressure altered K(fc) in a nonlinear relationship, suggesting non-Starling mechanism(s). nitro-l-arginine methyl ester and heparanase III attenuated the effects of increased capillary pressure on K(fc), demonstrating active mechanotransduction leading to barrier dysfunction. The nitric oxide (NO) donor S-nitrosoglutathione exacerbated pressure-mediated increase in K(fc). Ventilation strategies altered lung NO concentration and the K(fc) response to increases in vascular pressure. This is the first study to demonstrate a role for the glycocalyx in whole lung mechanotransduction and has important implications in understanding the regulation of vascular permeability in the context of vascular pressure, fluid status, and ventilation strategies.     

Effect of delays in primary care referral on survival of women with epithelial ovarian cancer: retrospective audit

ObjectiveTo examine referral pathways from primary care for patients with epithelial ovarian cancer and to identify factors related to survival at 18 months.DesignRetrospective review of patient notes.SettingGeneral practices and receiving hospitals within Mersey region.Subjects135 patients with epithelial ovarian cancer identified from an audit in the Mersey area between 1992 and 1994.Results105 (78%) women first presented to their general practitioner within four weeks of the onset of symptoms. 99 (73%) women were referred to hospital by their general practitioners within four weeks of presentation, and 95 (70%) were seen in hospital within two weeks of referral. Multivariate analysis with survival as the dependent variable identified age (odds ratio 0.96, 95% confidence interval 0.93 to 0.99) cancer stage III or more (0.15, 0.05 to 0.43), and non-specific symptoms (0.36, 0.14 to 0.89) as significant variables.ConclusionMost patients attended their general practitioner within four weeks and were referred within two weeks. No evidence was found that delays in referral or diagnosis adversely affected survival at 18 months. Stage of disease at surgery was the most important adverse factor. An effective screening programme is the most likely method to improve survival.

What is already known on this topic

Epithelial ovarian cancer is the most common gynaecological cancer in the United Kingdom75% of patients present with advanced incurable disease, and five year survival is 30%The Department of Health recommends that everyone suspected of having ovarian cancer should be seen within two weeks of referral by their general practitioner

What this study adds

78% of patients have had symptoms for less than 4 weeks when they present to general practice and are referred to hospital within four weeks of presentation70% of patients are seen in hospital within two weeks of the referralDelay by patients and general practitioners does not affect survival beyond 18 months