Nuclear ULK1 promotes cell death in response to oxidative stress through PARP1

Reactive oxygen species (ROS) may cause cellular damage and oxidative stress-induced cell death. Autophagy, an evolutionarily conserved intracellular catabolic process, is executed by autophagy (ATG) proteins, including the autophagy initiation kinase Unc-51-like kinase (ULK1)/ATG1. Although autophagy has been implicated to have both cytoprotective and cytotoxic roles in the response to ROS, the role of individual ATG proteins, including ULK1, remains poorly characterized. In this study, we demonstrate that ULK1 sensitizes cells to necrotic cell death induced by hydrogen peroxide (H2O2). Moreover, we demonstrate that ULK1 localizes to the nucleus and regulates the activity of the DNA damage repair protein poly (ADP-ribose) polymerase 1 (PARP1) in a kinase-dependent manner. By enhancing PARP1 activity, ULK1 contributes to ATP depletion and death of H2O2-treated cells. Our study provides the first evidence of an autophagy-independent prodeath role for nuclear ULK1 in response to ROS-induced damage. On the basis of our data, we propose that the subcellular distribution of ULK1 has an important role in deciding whether a cell lives or dies on exposure to adverse environmental or intracellular conditions.

A cluster randomised controlled trial to investigate the effectiveness and cost effectiveness of the 'Girls Active' intervention: a study protocol

BACKGROUND

Despite the health benefits of physical activity, data from the UK suggest that a large proportion of adolescents do not meet the recommended levels of moderate-to-vigorous physical activity (MVPA). This is particularly evident in girls, who are less active than boys across all ages and may display a faster rate of decline in physical activity throughout adolescence. The 'Girls Active' intervention has been designed by the Youth Sport Trust to target the lower participation rates observed in adolescent girls. 'Girls Active' uses peer leadership and marketing to empower girls to influence decision making in their school, develop as role models and promote physical activity to other girls. Schools are provided with training and resources to review their physical activity, sport and PE provision, culture and practices to ensure they are relevant and attractive to adolescent girls.

METHODS/DESIGN

This study is a two-arm cluster randomised controlled trial (RCT) aiming to recruit 20 secondary schools. Clusters will be randomised at the school level (stratified by school size and proportion of Black and Minority Ethnic (BME) pupils) to receive either the 'Girls Active' intervention or carry on with usual practice (1:1). The 20 secondary schools will be recruited from state secondary schools within the Midlands area. We aim to recruit 80 girls aged 11-14 years in each school. Data will be collected at three time points; baseline and seven and 14 months after baseline. Our primary aim is to investigate whether 'Girls Active' leads to higher objectively measured (GENEActiv) moderate-to-vigorous physical activity in adolescent girls at 14 months after baseline assessment compared to the control group. Secondary outcomes include other objectively measured physical activity variables, adiposity, physical activity-related psychological factors and the cost-effectiveness of the 'Girls Active' intervention. A thorough process evaluation will be conducted during the course of the intervention delivery.

DISCUSSION

The findings of this study will provide valuable information on whether this type of school-based approach to increasing physical activity in adolescent girls is both effective and cost-effective in the UK.

TRIAL REGISTRATION

ISRCTN10688342. Registered 12 January 2015.

Spontaneous pneumothorax; a multicentre retrospective analysis of emergency treatment, complications and outcomes

BACKGROUND

Spontaneous pneumothorax can be managed initially by observation, aspiration or chest drain insertion.

AIMS

To determine the clinical features of spontaneous pneumothorax in patients presenting to the emergency department (ED), interventions, outcomes and potential risk factors for poor outcomes after treatment.

METHODS

Retrospective chart review from ED of three major referral and two general hospitals in Australia of presentations with primary spontaneous pneumothorax (PSP) or secondary spontaneous pneumothorax (SSP). Main outcomes were prolonged air leak (>5 days) and pneumothorax recurrence within 1 year.

RESULTS

We identified 225 people with PSP and 98 with SSP. There were no clinical tension pneumothoraces with hypotension. Hypoxaemia (haemoglobin oxygen saturation measured by pulse oximetry ≤92%) occurred only in SSP and in older patients (age >50 years) with PSP. Drainage was performed in 150 (67%) PSP and 82 (84%) SSP. Prolonged air leak occurred in 16% (95% confidence interval 10-23%) of PSP and 31% (21-42%) of SSP. Independent risk factors for prolonged drainage were non-asthma SSP and pneumothorax size >50%. Complications were recorded in 11% (7.5-16%) of those having drains inserted. Recurrences occurred in 5/91 (5%, 1.8-12%) of those treated without drainage versus 40/232 (17%, 13-23%) of those treated by drainage, of which half occurred in the first month after drainage.

CONCLUSION

Pneumothorax drainage is associated with substantial morbidity including prolonged air leak. As PSP appears to be well tolerated in younger people even with large pneumothoraces, conservative treatment in this subgroup may be a viable option to improve patient outcomes, but this needs to be confirmed in a clinical trial.

Tracheal stenosis following percutaneous dilatational tracheostomy using the single tapered dilator: an MRI study

Despite widespread adoption of percutaneous dilatational tracheostomy within the critical care setting, there is still uncertainty regarding long-term complications, particularly in relation to missed or subclinical tracheal stenosis. In this study, all patients underwent tracheostomy using a single tapered dilator ≥ three months prior to enrollment and were evaluated using magnetic resonance imaging, spirometry and questionnaire. Tracheal area was recorded and deemed to be stenotic if a reduction of ≥10% was found. Fifty patients underwent magnetic resonance imaging and 49 attended for interview. Five patients were diagnosed with tracheal stenosis-none were symptomatic. Six of the 50 tracheostomies were technically difficult. Spirometry was not predictive of stenosis. A post critical care exercise tolerance of less than 100 metres was found in four tracheal stenosis patients. The prevalence of subclinical tracheal stenosis following percutaneous tracheostomy is low, with limited clinical significance. No patients required corrective surgery for tracheal stenosis. Routine airway follow-up in asymptomatic patients appears to be unwarranted.

Thirty-six vaginal constructions: lessons learned

OBJECTIVES

The use of bowel for vaginal construction is a well-established procedure. In this paper, the lessons learned from 36 vaginoplasties over a 34-year period are discussed.

METHODS

Between 1980 and 2013, 36 patients between 1 and 21 years of age underwent vaginal construction. In 27 of the 36 patients, an inverted V-shaped perineal skin flap was incorporated into the posterior wall of the neovagina, and, when required, a detubularized pouch was used to avoid traction on the vascular pedicle. In nine patients, the sigmoid colon was anastomosed, in a circumferential manner, to the short blind-ending vaginal dimple.

RESULTS

Two of the nine sigmoid vaginas, where the perineal skin flap was omitted, developed introital stenosis. None of the sigmoid neovaginas that included the perineal flap developed stenosis. One patient with ileal segment vagina, at the onset of puberty, developed introital stenosis after 10 years; this was successfully corrected. Nineteen out of 28 patients available for long-term follow up were sexually active and reported no dyspareunia.

CONCLUSIONS

Detubularization and reconfiguration to form a pouch reduces the traction on the mesentery of the bowel segment, which ensures adequate blood supply to the distal entero-cutaneous junction. The inverted V-shaped perineal skin flap should be incorporated in the anastomosis to avoid circumferential suture line and introital stenosis.

Long-term outcome of the anal fistula plug for anal fistula of cryptoglandular origin

AIM

This study aimed to evaluate the long-term outcome of the anal fistula plug in the treatment of anal fistula of cryptoglandular origin.

METHOD

A review of all patients who had at least one anal fistula plug inserted from March 2007 to August 2008 was performed. Only anal fistulae of cryptoglandular origin were included. Success was defined as the closure of the external opening with no further purulent discharge or collection.

RESULTS

Thirty anal fistula plugs were inserted in 26 patients [median age 40 (26-70) years]. Twenty-six of the fistulae were transsphincteric and three were suprasphincteric. One patient had a high intersphincteric fistula, which was the only fistula that did not have a seton inserted. The median duration between seton insertion and the plug procedure was 12 (4-28) weeks. The median length of the fistula tract was 3 (1-7.5) cm. After a median follow-up of 59 (13-97) weeks, 26 (86.7%) fistulae recurred. Of the 26 failures, the median time to failure was 8 (2-54) weeks. Subsequent surgical interventions were performed in 20 of the failures.

CONCLUSION

The role of the fistula plug in the management of anal fistula of cryptoglandular origin remains debatable and warrants further evaluation.

Studies of aging in ames dwarf mice: Effects of caloric restriction

Ames dwarf mice, which are small and deficient in growth homone (GH), prolactin (PRL), and thyroid stimulating hormone (TSH) live much longer (1-1.25 years) than their normal siblings. It was of interest to examine the response of these animals to caloric restriction (CR) because of the possibility that dwarf mice are voluntarily caloric restricted. We are testing the hypothesis that this possible natural caloric restriction will negate any benefits of an imposed CR on lifespan. Male and female Ames dwarf mice and their normal counterparts have been fed ad libitum (AL) or a 30% CR diet for 25-29 months. Animals were monitored daily and weighed weekly. At 12-15 months of age, CR mice weighed significantly less than their AL fed counterparts (normal females: -42%, normal males: -23%, dwarf females: -18.8%, and dwarf males: -22.2%). Only in dwarf females has this significant difference disappeared with age. At one year of age, a comparison of daily food consumption revealed that female dwarf mice consume significantly more food per gram body weight than normal females and a similar tendency is evident for males. Although they received 30% less food, CR mice ate the same amount as AL mice per gram body weight. On measures of total locomotor activity, CR mice were significantly more active than their AL-fed counterparts. On an inhibitory avoidance learning task, 18-21 month old dwarf mice exhibited significantly better retention than their age-and diet-matched normal counterparts. Histopathological analysis in aging dwarf versus normal mice suggested that the incidence of tumors does not differ between the two groups but tumors appear to develop later in dwarf than in normal mice. After 2.25 years on the study 27% of AL normals, 52% of CR normals, 74% of AL dwarfs, and 87% of CR dwarfs are still alive. We conclude that Ames dwarfs are not CR mimetics although they share many characteristics. It remains to be determined whether CR will delay aging and cause a further life extension in Ames dwarf mice.