The ryanodine receptor agonist 4-chloro-3-ethylphenol blocks ORAI store-operated channels

BACKGROUND

Depletion of the Ca²⁺ store by ryanodine receptor (RyR) agonists induces store-operated Ca²⁺ entry (SOCE). 4-Chloro-3-ethylphenol (4-CEP) and 4-chloro-m-cresol (4-CmC) are RyR agonists commonly used as research tools and diagnostic reagents for malignant hyperthermia. Here, we investigated the effects of 4-CEP and its analogues on SOCE.

EXPERIMENTAL APPROACH

SOCE and ORAI1-3 currents were recorded by Ca²⁺ imaging and whole-cell patch recordings in rat L6 myoblasts and in HEK293 cells overexpressing STIM1/ORAI1-3.

KEY RESULTS

4-CEP induced a significant release of Ca²⁺ in rat L6 myoblasts, but inhibited SOCE. The inhibitory effect was concentration-dependent and more potent than its analogues 4-CmC and 4-chlorophenol (4-ClP). In the HEK293 T-REx cells overexpressing STIM1/ORAI1-3, 4-CEP inhibited the ORAI1, ORAI2 and ORAI3 currents evoked by thapsigargin. The 2-APB-induced ORAI3 current was also blocked by 4-CEP. This inhibitory effect was reversible and independent of the Ca²⁺ release. The two analogues, 4-CmC and 4-ClP, also inhibited the ORAI1-3 channels. Excised patch and intracellular application of 4-CEP demonstrated that the action site was located extracellularly. Moreover, 4-CEP evoked STIM1 translocation and subplasmalemmal clustering through its Ca²⁺ store-depleting effect via the activation of RyR, but no effect on STIM1 redistribution was observed in cells co-expressing STIM1/ORAI1-3.

CONCLUSION AND IMPLICATIONS

4-CEP not only acts as a RyR agonist to deplete the Ca²⁺ store and trigger STIM1 subplasmalemmal translocation and clustering, but also directly inhibits ORAI1-3 channels. These findings demonstrate a novel pharmacological property for the chlorophenol derivatives that act as RyR agonists.     

Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery

Background

Extracorporeal life support (ECLS) has been used for over two decades in select patients after cardiac surgery. We previously described factors associated with death in this population. We now review our recent experience to reassess factors related to mortality.

Methods

All pediatric patients who received ECLS support within 7 days after surgery between July 1995 and June 2001 were examined to describe clinical features associated with survival. We compared the results with our prior report to assess changes in practice and outcome.

Results

Seventy-four patients were followed. Fifty percent survived to discharge. Hospital survival was not significantly related to patient age, cannulation site, or indication. Thirty-five percent of patients required hemofiltration while on ECLS and were significantly less likely to survive (23% vs 65%). A multivariate analysis combining all children from our prior report with the present cohort revealed that patients who received hemofiltration were five times more likely to die (odds ratio 5.01, 95% confidence interval 2.11-11.88). Children with an adequate two-ventricular repair had lower risk of death (odds ratio 0.42, 95% confidence interval 0.19-0.91) after adjusting for patient age, study period, and hours elapsed before initiation of ECLS after surgery.

Conclusions

Patients with an adequate two-ventricle repair have significantly higher hospital survival, whereas those with single ventricle physiology or need for dialysis have decreased survival.     

Therapy of the empyema thoracis. Why not thoracostoma?

Empyema toracis can be defined as a purulent pleural effusion. From 1998 to 2003 we treated 106 patients (87 men and 19 women), aged between 23 and 82 years, affected by localized empyema toracis. All of them received initially a chest tube and 73 of them (60 men and 13 women), in combination with selected antibiotics, had an uneventful recovery. Twenty three patients (17 men and 5 women) underwent thoracotomy and pleural decortication, and 7 patients (6 men and 1 woman) underwent open drainage, that means a thoracostoma. All these 7 patients were affected by chronic empyema: 3 of them with residual post-pneumectomy empyema (1 for lung cancer and 2 for tubercular lung disease); 3 had destroyed lung and 1 was suffering for multiorgan deficiency (respiratory, cardiac and chronic renal insufficiency). The thoracostoma procedure was under general tube anaesthesia with tracheal intubation. The mean surgical time was 26 minutes. The mean postoperative hospital stay was 10 days. In this period of time no death has been recorded or any kind of complication. Before the dismission all of them were teached with their familiars how to take care of the remaining thoracostoma. After the dismission all the patients were followed as outpatients for a variable period, for 14 and 36 months. During this period there were neither complications nor recidives, and all the patients have accepted the "thoracostoma" as a new way of life. Therefore thoracostoma appears as an acceptable, useful and no dangerous solution for the treatment of the chronic thoracic empyema.     

Social Capital,Perceived Economic Affluence,and Smoking During Adolescence: A Cross-Sectional Study

Background: Smoking is among the health risk behaviors taken up by many adolescents with lifelong consequences and associations with multiple health risk behaviors. Smoking and smoking initiation in adolescence involves an interaction between micro-, meso-, and macro systems, including neighborhoods and the greater community. Objectives: To examine the associations of individual social and economic capital with self-reported health, life satisfaction, and smoking behavior in adolescents. Methods: Using a multistage random sampling of junior high school students (16–18 years old) in Crete, Greece, 703 adolescents (90.2% 16 years old; 55.6% girls, participation rate 84.2%) completed an anonymous questionnaire based on HBSC study and the Youth Social Capital Scale (YSCS) during April–June 2008. Multiple logistic regression models were performed adjusted for potential confounders. Results: Adolescents with high participation in their neighborhoods and communities (higher structural social capital) displayed lower odds for daily smoking; those feeling unsafe (lower cognitive social capital) were at greater odds of daily smoking. Adolescents with less friends and acquaintances had lower odds of having tried tobacco products. Smoking was not related to any economic capital variables (perceived affluence, paternal and maternal employment status). Adolescents with low/medium versus high total social capital were at higher odds for low life satisfaction and fair/bad versus excellent self-rated health. Conclusions/Importance: Social capital theory may provide a better understanding in identifying the social context that is protective or harmful to adolescents' smoking. Public health organizations at all levels need to incorporate social capital theory in their interventions.     

Endometrial injury for RIF patients undergoing IVF/ICSI: a prospective nonrandomized controlled trial

To evaluate the effect of endometrial injury on clinical outcomes in subfertile women with repeated implantation failures (RIF) undergoing assisted reproduction. In this prospective nonrandomized controlled trial, 103 subfertile women with RIF were included. Fifty-one underwent endometrial injury through hysteroscopy in the early follicular phase of the previous cycle and 52 underwent the standard protocol without any intervention. Live birth and miscarriage were the primary outcomes. Clinical and in vitro fertilization (IVF) cycle characteristics, were also compared between groups. Both groups were comparable in terms of baseline and cycle characteristics. Live birth rates were significantly higher in the study, compared with the control group (18/51 vs. 8/52, odds ratio (OR)?=?0.25; 95% confidence interval (CI)?=?0.10–0.64; p?=?0.020), although miscarriage rates were similar (7/51 vs. 10/52, OR=?0.25; 95%CI=?0.12–0.66; p?=?0.452). The rest of the outcomes parameters were comparable between groups. Logistic regression analysis revealed that endometrial injury and duration of subfertility were independent predictors of live birth after control of other variables (OR?=?2.818; 95%CI?=?1.044–7.605; p?=?0.041 and OR?=?0.674; 95%CI?=?0.461–0.985, p?=?0.042, respectively). Endometrial injury induced through office hysteroscopy in the preceding cycle in subfertile women with RIF improves live birth rates.     

Neuroglobin and myoglobin in non-small cell lung cancer: expression, regulation and prognosis

Globins are respiratory proteins involved in oxygen metabolism, which is a critical factor in tumor growth and progression. The status of neuroglobin and myoglobin is largely unknown in human malignancies, including lung cancer. The aim of this study was to explore mRNA expression profiles, potential regulatory mechanisms and clinicopathological associations of neuroglobin and myoglobin in non-small cell lung cancer (NSCLC). We screened 208 surgically resected NSCLC specimens and a panel of lung normal and cancer cell lines. The mRNA expression of neuroglobin, myoglobin and hypoxia markers (HIF1α and VEGFa) was measured with qRTPCR, while neuroglobin promoter methylation was assessed with Pyrosequencing. Neuroglobin and myoglobin were upregulated in the tumor samples compared to normal tissue (p = 1.3 × 10⁻²² and p = 1.9 × 10⁻⁹, respectively). Neuroglobin was more frequently overexpressed in squamous cell carcinomas (SqCCL) than adenocarcinomas. Overexpression of myoglobin was more profound in adenocarcinomas, which correlated with poor survival (p = 0.013). Neuroglobin promoter was hypermethylated in 30.8% of NSCLC cases, which correlated with neuroglobin mRNA downregulation. The epigenetic regulation of neuroglobin was confirmed by treating lung cell lines with 5′azadeoxycytidine and/or trichostatin A. Expression of both genes correlated with the expression of HIF1α (neuroglobin: p = 3.8 × 10⁻⁵, myoglobin: p = 1.1 × 10⁻¹¹). Myoglobin expression was also associated to that of VEGFa (p = 2.1 × 10⁻⁷). Hypoxia-dependent upregulation of both globins was validated in vitro. In summary, neuroglobin and myoglobin overexpression in NSCLC is associated with histological subtype, hypoxia and, in case of neuroglobin - epigenetic regulation. Myoglobin expression may have potential significance in the prognostication of lung adenocarcinomas.     

HPV vaccine acceptance among female Greek students

The human papillomavirus (HPV) vaccine protects against HPV-related disease. The aim of this study was to assess acceptance of HPV vaccination among female Greek students. A sample of 573 students aged 18-25 years participated in the present study. Interviews were performed using a structured questionnaire. Of the respondents, 3% were not aware of the HPV vaccine. Of the subjects, 10.47% had been administered the HPV vaccine. Of the respondents who had not been administered the vaccine, 43.86% were not willing to accept it because of the rumors of serious side effects. The results highlight the need for additional education and health promotion regarding HPV vaccination and cervical cancer prevention.     

Fok-I polymorphism of vitamin D receptor gene and the presence of renal dysfunction in patients with β-thalassemia major

Recent evidence supports the presence of renal dysfunction even among young patients with β-thalassemia major. However, the possible genetic contribution has never been investigated. The aim of this study was to correlate the presence of Fok-I polymorphism of the vitamin D receptor gene with abnormal levels of early markers of renal impairment in children and young adults with thalassemia. Thirty-four patients (19 male and 15 female) with β-thalassemia major on conventional treatment, with a mean decimal age of 14.62 ± 5.47 years (range: 5-22 years), were included in the study. Markers of renal function were determined in serum and in urine and patients were genotyped for Fok-I gene polymorphism. Genotype frequencies were similar to those previously reported for other populations: 47.06% of the patients were homozygous for the F allele, 41.18% were heterozygous, and 11.76% were homozygous for the f allele. A considerable number of patients demonstrated impaired renal function with increased serum cystatin C levels (29.41%), glomerular dysfunction with proteinuria (68%), as well as significant tubulopathy with hypercalciuria (73.08%), and increased levels of urinary β(2)-microglobulin (29.41%). When patients were stratified according to Fok-I polymorphism, a significantly higher prevalence of abnormally increased serum levels of cystatin C was observed in patients being homozygous for the f allele (75%) compared with those being heterozygous (Ff) or homozygous for the F allele (14.29% and 31.25%, respectively, P = .02). Further studies are needed to confirm these preliminary results and elucidate the possible mechanisms involved.