MutT Homolog 1 (MTH1) maintains multiple KRAS-driven pro-malignant pathways

Oncogenic RAS promotes production of reactive oxygen species (ROS), which mediate pro-malignant signaling but can also trigger DNA damage-induced tumor suppression. Thus RAS-driven tumor cells require redox-protective mechanisms to mitigate the damaging aspects of ROS. Here, we show that MutT Homolog 1 (MTH1), the mammalian 8-oxodGTPase that sanitizes oxidative damage in the nucleotide pool, is important for maintaining several KRAS-driven pro-malignant traits in a nonsmall cell lung carcinoma (NSCLC) model. MTH1 suppression in KRAS-mutant NSCLC cells impairs proliferation and xenograft tumor formation. Furthermore, MTH1 levels modulate KRAS-induced transformation of immortalized lung epithelial cells. MTH1 expression is upregulated by oncogenic KRAS and correlates positively with high KRAS levels in NSCLC human tumors. At a molecular level, in p53-competent KRAS-mutant cells, MTH1 loss provokes DNA damage and induction of oncogene-induced senescence. In p53-nonfunctional KRAS-mutant cells, MTH1 suppression does not produce DNA damage but reduces proliferation and leads to an adaptive decrease in KRAS expression levels. Thus, MTH1 not only enables evasion of oxidative DNA damage and its consequences, but can also function as a molecular rheostat for maintaining oncogene expression at optimal levels. Accordingly, our results indicate MTH1 is a novel and critical component of oncogenic KRAS-associated malignancy and its inhibition is likely to yield significant tumor-suppressive outcomes in KRAS-driven tumors.

A cluster randomised controlled trial and economic evaluation of a structured training programme for caregivers of inpatients after stroke: the TRACS trial

BACKGROUND

The majority of stroke patients are discharged home dependent on informal caregivers, usually family members, to provide assistance with activities of daily living (ADL), including bathing, dressing and toileting. Many caregivers feel unprepared for this role and this may have a detrimental effect on both the patient and caregiver.

OBJECTIVE

To evaluate whether or not a structured, competency-based training programme for caregivers [the London Stroke Carer Training Course (LSCTC)] improved physical and psychological outcomes for patients and their caregivers after disabling stroke, and to determine if such a training programme is cost-effective.

DESIGN

A pragmatic, multicentre, cluster randomised controlled trial.

SETTING

Stratified randomisation of 36 stroke rehabilitation units (SRUs) to the intervention or control group by geographical region and quality of care.

PARTICIPANTS

A total of 930 stroke patient and caregiver dyads were recruited. Patients were eligible if they had a confirmed diagnosis of stroke, were medically stable, were likely to return home with residual disability at the time of discharge and had a caregiver available, willing and able to provide support after discharge. The caregiver was defined as the main person--other than health, social or voluntary care provider--helping with ADL and/or advocating on behalf of the patient.

INTERVENTION

The intervention (the LSCTC) comprised a number of caregiver training sessions and competency assessment delivered by SRU staff while the patient was in the SRU and one recommended follow-up session after discharge. The control group continued to provide usual care according to national guidelines. Recruitment was completed by independent researchers and participants were unaware of the SRUs' allocation.

MAIN OUTCOME MEASURES

The primary outcomes were self-reported extended ADL for the patient and caregiver burden measured at 6 months after recruitment. Secondary outcomes included quality of life, mood and cost-effectiveness, with final follow-up at 12 months.

RESULTS

No differences in primary outcomes were found between the groups at 6 months. Adjusted mean differences were -0.2 points [95% confidence interval (CI) -3.0 to 2.5 points; p = 0.866; intracluster correlation coefficient (ICC) = 0.027] for the patient Nottingham Extended Activities of Daily Living score and 0.5 points (95% CI -1.7 to 2.7 points; p = 0.660; ICC = 0.013) for the Caregiver Burden Scale. Furthermore, no differences were detected in any of the secondary outcomes. Intervention compliance varied across the units. Half of the participating centres had a compliance rating of > 60%. Analysis showed no evidence of higher levels of patient independence or lower levels of caregiver burden in the SRUs with better levels of intervention compliance. The economic evaluation suggests that from a patient and caregiver perspective, health and social care costs, societal costs and outcomes are similar for the intervention and control groups at 6 months, 12 months and over 1 year.

CONCLUSIONS

We have conducted a robust multicentre, cluster randomised trial, demonstrating for the first time that this methodology is feasible in stroke rehabilitation research. There was no difference between the LSCTC and usual care with respect to improving stroke patients' recovery, reducing caregivers' burden, or improving other physical and psychological outcomes, nor was it cost-effective compared with usual care. Compliance with the intervention varied, but analysis indicated that a dose effect was unlikely. It is possible that the immediate post-stroke period may not be the ideal time for the delivery of structured training. The intervention approach might be more relevant if delivered after discharge by community-based teams.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49208824.

FUNDING

This project was funded by the MRC and is managed by the NIHR (project number 09/800/10) on behalf of the MRC-NIHR partnership, and will be published in full in Health Technology Assessment; Vol. 17, No. 46. See the NIHR Journals Library website for further project information.

Impact of unilateral vocal fold mobility impairment on laryngopulmonary physiology

OBJECTIVE

To examine the impact of unilateral vocal fold mobility impairment (UVFMI) on airway physiology.

STUDY DESIGN

Cross-sectional observational study.

PARTICIPANTS

There were 21 patients with UVFMI and 53 controls.

MAIN OUTCOME MEASURES

All patients and patient controls underwent a maximum-effort flow-volume loop examination. Forced expiratory flow in one second (FEV1 ), forced expiratory volume (FVC), peak inspiratory flow rate and peak expiratory flow rate (PIFR and PEFR, respectively) and area under the inspiratory and expiratory flow-volume loops (AUCI nspiratory and AUCE xpiratory, respectively) were measured. The ratio of PEFR to PIFR and AUCE xpiratory to AUCI nspiratory was derived.

RESULTS

There were 48 males and 26 females. Mean age at measurement was 39 ± 11 years. Patients and controls were matched for age, sex, height and weight. None of the expiratory variables were significantly different between the groups. PIFR was significantly lower in UVFMI patients compared with controls (3.4 ± 1.2 versus 5.3 ± 1.8; P < 0.0001), as was AUCI nspiratory (11.5 ± 6.3 versus 17.5 ± 8.5; P = 0.0002). PEFR/PIFR provided the best differentiation between patients with UVFMI and controls with an area under the Receiver Operating Characteristic (ROC) curve of 0.96 and at a threshold of 1.9, and PEFR/PIFR had sensitivity and specificity of 95.2% and 90.6%, respectively.

CONCLUSIONS

Flow-volume loops are a non-invasive method of studying vocal abduction and could compliment voice assessment and laryngoscopy in UVFMI. With further research, they could provide an outcome measure for laryngeal rehabilitative procedures, and a shared physiological language for screening and surgical quality assurance.

Intensification of medication and glycaemic control among patients with type 2 diabetes - the ADVANCE trial

AIMS

The aim of this study was to assess associations between patient characteristics, intensification of blood glucose-lowering treatment through oral glucose-lowering therapy and/or insulin and effective glycaemic control in type 2 diabetes.

METHODS

11 140 patients from the Action in Diabetes and Vascular disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE) trial who were randomized to intensive glucose control or standard glucose control and followed up for a median of 5 years were categorized into two groups: effective glycaemic control [haemoglobin A1c (HbA1c) ≤ 7.0% or a proportionate reduction in HbA1c over 10%] or ineffective glycaemic control (HbA1c > 7.0% and a proportionate reduction in HbA1c less than or equal to 10%). Therapeutic intensification was defined as addition of an oral glucose-lowering agent or commencement of insulin. Pooled logistic regression models examined the associations between patient factors, intensification and effective glycaemic control.

RESULTS

A total of 7768 patients (69.7%), including 3198 in the standard treatment group achieved effective glycaemic control. Compared to patients with ineffective control, patients with effective glycaemic control had shorter duration of diabetes and lower HbA1c at baseline and at the time of treatment intensification. Treatment intensification with addition of an oral agent or commencement of insulin was associated with a 107% [odds ratio, OR: 2.07 (95% confidence interval, CI: 1.95-2.20)] and 152% [OR: 2.52 (95% CI: 2.30-2.77)] greater chance of achieving effective glycaemic control, respectively. These associations were robust after adjustment for several baseline characteristics and not modified by the number of oral medications taken at the time of treatment intensification.

CONCLUSIONS

Effective glycaemic control was associated with treatment intensification at lower HbA1c levels at all stages of the disease course and in both arms of the ADVANCE trial.

Reproducibility patterns of multiple rapid swallows during high resolution esophageal manometry provide insights into esophageal pathophysiology

BACKGROUND

Multiple rapid swallows (MRS) during esophageal high resolution manometry (HRM) assess esophageal neuromuscular integrity by evaluating postdeglutitive inhibition and rebound contraction, but most reports performed only a single MRS sequence. We assessed patterns of MRS reproducibility during clinical HRM in comparison to a normal cohort.

METHODS

Consecutive clinical HRM studies were included if two separate MRS sequences (four to six rapid swallows ≤4 s apart) were successfully performed. Chicago Classification diagnoses were identified; contraction wave abnormalities were additionally recorded. MRS-induced inhibition (contraction ≤3 cm during inhibition phase) and rebound contraction was assessed, and findings compared to 18 controls (28.0 ± 0.7 year, 50.0% female). Reproducibility consisted of similar inhibition and contraction responses with both sequences; discordance was segregated into inhibition and contraction phases.

KEY RESULTS

Multiple rapid swallows were successfully performed in 89.3% patients and all controls; 225 subjects (56.2 ± 0.9 year, 62.7% female) met study inclusion criteria. Multiple rapid swallows were reproducible in 76.9% patients and 94.4% controls (inhibition phase: 88.0% vs 94.4%, contraction phase 86.7% vs 100%, respectively, p = ns). A gradient of reproducibility was noted, highest in well-developed motor disorders (achalasia spectrum, hypermotility disorders, and aperistalsis, 91.7-100%, p = ns compared to controls); and lower in lesser motor disorders (contraction wave abnormalities, esophageal body hypomotility) or normal studies (62.2-70.8%, p < 0.0001 compared to well-developed motor disorders). Inhibition phase was most discordant in contraction wave abnormalities, while contraction phase was most discordant when studies were designated normal.

CONCLUSIONS & INFERENCES

Multiple rapid swallows are highly reproducible, especially in well-developed motor disorders, and complement the standard wet swallow manometry protocol.

The impact of non-adherence to medication in patients with schizophrenia on health, social care and societal costs. Analysis of the QUATRO study

Aims. For people with schizophrenia, non-adherence to antipsychotic medications may result in high use of health and other services. The objective of our research was to examine the economic consequences of non-adherence in patients with schizophrenia taking antipsychotic medication. Methods. Data were taken from QUATRO, a randomized controlled trial that drew a sample of adults with schizophrenia receiving psychiatric services in four European cities: Amsterdam, Leipzig, London and Verona. Trial inclusion criteria were a clinical diagnosis of schizophrenia, requiring on-going antipsychotic medication for at least 1-year following baseline assessment, and exhibiting evidence of clinical instability in the year prior to baseline. The patient-completed Medication Adherence Questionnaire (MAQ) was used to calculate the 5-point Morisky index of adherence. Generalized linear models (GLM) were developed to determine the effect of adherence on (i) health and social care and (ii) societal costs before and after treatment, taking into account other potential cost-influencing factors. Results. The effect of non-adherence on costs was mixed. For different groups of services, and according to treatment group assignment, non-adherence was both negatively and positively associated with costs. Conclusions. The impact of non-adherence on costs varies across the types of services used by individuals with schizophrenia.

Soil application of an encapsulated CO2 source and its potential for management of western corn rootworm larvae

Western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae use carbon dioxide (CO2) to locate the roots of their hosts. This study investigated whether an encapsulated CO2 source (CO2-emitting capsules) is able to outcompete CO2 gradients established by corn root respiration in the soil. Furthermore, the following two management options with the capsules were tested in semifield experiments (0.5- to 1-m2 greenhouse plots): the disruption of host location and an "attract-and-kill" strategy in which larvae were lured to a soil insecticide (Tefluthrin) between the corn rows. The attract-and-kill strategy was compared with an application of Tefluthrin in the corn rows (conventional treatment) at 33 and 18% of the standard field application rate. Application of the CO2-emitting capsules 30 cm from the plant base increased CO2 levels near the application point for up to 20 d with a peak at day 10. Both the disruption of host location and an attract-and-kill strategy caused a slight but nonsignificant reduction in larval densities. The disruption of host location caused a 17% reduction in larval densities, whereas an attract-and-kill strategy with Tefluthrin added at 33 and 18% of the standard application rate caused a 24 and 27% reduction in larval densities, respectively. As presently formulated, the CO2-emitting capsules, either with or without insecticide, do not provide adequate control of western corn rootworm.

A randomised controlled trial of a consumer-focused e-health strategy for cardiovascular risk management in primary care: the Consumer Navigation of Electronic Cardiovascular Tools (CONNECT) study protocol

INTRODUCTION

Fewer than half of all people at highest risk of a cardiovascular event are receiving and adhering to best practice recommendations to lower their risk. In this project, we examine the role of an e-health-assisted consumer-focused strategy as a means of overcoming these gaps between evidence and practice. Consumer Navigation of Electronic Cardiovascular Tools (CONNECT) aims to test whether a consumer-focused e-health strategy provided to Aboriginal and Torres Strait Islander and non-indigenous adults, recruited through primary care, at moderate-to-high risk of a cardiovascular disease event will improve risk factor control when compared with usual care.

METHODS AND ANALYSIS

Randomised controlled trial of 2000 participants with an average of 18 months of follow-up to evaluate the effectiveness of an integrated consumer-directed e-health portal on cardiovascular risk compared with usual care in patients with cardiovascular disease or who are at moderate-to-high cardiovascular disease risk. The trial will be augmented by formal economic and process evaluations to assess acceptability, equity and cost-effectiveness of the intervention. The intervention group will participate in a consumer-directed e-health strategy for cardiovascular risk management. The programme is electronically integrated with the primary care provider's software and will include interactive smart phone and Internet platforms. The primary outcome is a composite endpoint of the proportion of people meeting the Australian guideline-recommended blood pressure (BP) and cholesterol targets. Secondary outcomes include change in mean BP and fasting cholesterol levels, proportion meeting BP and cholesterol targets separately, self-efficacy, health literacy, self-reported point prevalence abstinence in smoking, body mass index and waist circumference, self-reported physical activity and self-reported medication adherence.

ETHICS AND DISSEMINATION

Primary ethics approval was received from the University of Sydney Human Research Ethics Committee and the Aboriginal Health and Medical Research Council. Results will be disseminated via the usual scientific forums including peer-reviewed publications and presentations at international conferences

CLINICAL TRIALS REGISTRATION NUMBER

ACTRN12613000715774.