Genetic determinants of micronucleus formation in vivo.

Genomic instability arising from defective responses to DNA damage1 or mitotic chromosomal imbalances2 can lead to the sequestration of DNA in aberrant extranuclear structures called micronuclei (MN). Although MN are a hallmark of ageing and diseases associated with genomic instability, the catalogue of genetic players that regulate the generation of MN remains to be determined. Here we analyse 997 mouse mutant lines, revealing 145 genes whose loss significantly increases (n = 71) or decreases (n = 74) MN formation, including many genes whose orthologues are linked to human disease. We found that mice null for Dscc1, which showed the most significant increase in MN, also displayed a range of phenotypes characteristic of patients with cohesinopathy disorders. After validating the DSCC1-associated MN instability phenotype in human cells, we used genome-wide CRISPR-Cas9 screening to define synthetic lethal and synthetic rescue interactors. We found that the loss of SIRT1 can rescue phenotypes associated with DSCC1 loss in a manner paralleling restoration of protein acetylation of SMC3. Our study reveals factors involved in maintaining genomic stability and shows how this information can be used to identify mechanisms that are relevant to human disease biology1.

Diabetes self-management education exposure and glycated haemoglobin levels among Marshallese participants in a randomized controlled study.

AIMS: A randomized control trial (RCT) of diabetes self-management education (DSME), undertaken by a community-based participatory research (CBPR) partnership between the University of Arkansas for Medical Sciences (UAMS) and the Marshallese community in Arkansas. The RCT examined the effect of hours of intervention exposure, with the hypothesis that increased exposure is one reason the Adapted-Family DSME was found to be more effective than the Standard DSME. METHODS: Some 221 Marshallese with type 2 diabetes were randomized to an Adapted-Family DSME group (in-home setting) (n = 110) or a Standard DMSE group (community setting) (n = 111). The Adapted-Family DSME included 10 h of education that covered the core self-care elements recommended by the American Diabetes Association (ADA) and American Association of Diabetes Educators' (AADE) recommendations. The Standard DSME included 10 h of intervention with all ADA and AADE core elements. RESULTS: The number of hours of intervention exposure in the Adapted-Family DSME arm (mean = 8.0; median = 10.0) was significantly higher than the number of hours of intervention received in the Standard DSME arm (mean = 1.5; median = 0.0). As hypothesized, higher exposure was associated with a significant reduction in HbA1c in a model including only study arm and exposure (P = 0.01), and in a model including study arm, exposure, and all demographic variables (P = 0.046). CONCLUSIONS: This finding is consistent with previous reviews that showed increased exposure to DSME produced improved glycaemic control and ≥ 10 h of DSME produces clinically meaningful reductions in HbA1c .

Community variation in adolescent cannabis use in Australia and the Netherlands.

BACKGROUND: While controversial, cannabis use is common, and often begins in adolescence. In Australia and the Netherlands, cannabis use is understood and legislated within a harm-minimisation framework. In Australia it is illegal to purchase or consume cannabis. Cannabis use in the Netherlands is illegal, except in licensed coffee shops where the sale and consumption of small amounts (5 g) are permitted. METHODS: Secondary school aged children in Victoria, Australia and the Netherlands were surveyed using the same culturally adapted questionnaire, designed to measure community rates of substance use and risk factors. Youth cannabis use and predictors of use were compared between the two countries. RESULTS: Similar levels of cannabis use in the last month were reported in Australia and the Netherlands (4.5%), with slightly lower use amongst girls, compared to boys. Common predictors of use were found in both the Australian and Netherlands sample. CONCLUSIONS: The findings suggest that interventions that effectively target similar risk factors to reduce or prevent cannabis use may have applications cross-nationally.

The Challenges of Using MRI During Radiotherapy.

In this article we aim to introduce the main considerations in integrating magnetic resonance imaging (MRI) into the radiotherapy workflow. We will cover the use of MRI for improved delineation, considerations regarding MRI-only workflows, and the potential of functional imaging techniques. The challenges of implementing each of these will be discussed to ensure safe usage in radiotherapy.

Trial protocol: a clustered, randomised, longitudinal, type 2 translational trial of alcohol consumption and alcohol-related harm among adolescents in Australia.

BACKGROUND: This cluster randomised control trial is designed to evaluate whether the Communities That Care intervention (CTC) is effective in reducing the proportion of secondary school age adolescents who use alcohol before the Australian legal purchasing age of 18 years. Secondary outcomes are other substance use and antisocial behaviours. Long term economic benefits of reduced alcohol use by adolescents for the community will also be assessed. METHODS: Fourteen communities and 14 other non-contiguous communities will be matched on socioeconomic status (SES), location, and size. One of each pair will be randomly allocated to the intervention in three Australian states (Victoria, Queensland and Western Australia). A longitudinal survey will recruit grade 8 and 10 students (M = 15 years old, N = 3500) in 2017 and conduct follow-up surveys in 2019 and 2021 (M = 19 years old). Municipal youth populations will also be monitored for trends in alcohol-harms using hospital and police administrative data. DISCUSSION: Community-led interventions that systematically and strategically implement evidence-based programs have been shown to be effective in producing population-level behaviour change, including reduced alcohol and drug use. We expect that the study will be associated with significant effects on alcohol use amongst adolescents because interventions adopted within communities will be based on evidence-based practices and target specific problems identified from surveys conducted within each community. TRIAL REGISTRATION: The trial was retrospectively registered in September, 2017 ( ACTRN12616001276448 ), as communities were selected prior to trial registration; however, participants were recruited after registration. Findings will be disseminated in peer-review journals and community fora.

The impact of alcohol management practices on sports club membership and revenue.

Issue addressed: The aim of this study was to assess the impact of an alcohol management intervention on community sporting club revenue (total annual income) and membership (number of club players, teams and spectators).Methods: The study employed a cluster randomised controlled trial design that allocated clubs either an alcohol accreditation intervention or a control condition. Club representatives completed a scripted telephone survey at baseline and again ~3 years following. Demographic information about clubs was collected along with information about club income.Results: Number of players and senior teams were not significantly different between treatment groups following the intervention. The intervention group, however, showed a significantly higher mean number of spectators. Estimates of annual club income between groups at follow-up showed no significant difference in revenue.Conclusions: This study found no evidence to suggest that efforts to reduce alcohol-related harm in community sporting clubs will compromise club revenue and membership.So what?: These findings suggest that implementation of an intervention to improve alcohol management of sporting clubs may not have the unintended consequence of harming club viability.

The density of alcohol outlets and adolescent alcohol consumption: An Australian longitudinal analysis.

Higher density of alcohol outlets has been linked to increased levels of adolescent alcohol-related behaviour. Research to date has been cross-sectional. A longitudinal design using two waves of annual survey data from the Australian arm of the International Youth Development Study was used. The sample comprised 2835 individuals with average age at wave 2 of 14 years (SD=1.67; range=11-17 years). GSEM was used to examine how absolute levels of alcohol outlet density was associated with student-reported alcohol use one year later, while controlling for prior alcohol use, risk factors at wave one and changes in density over the 2 years. Adolescents' perception of alcohol availability and friends' alcohol use were tested as potential mediators of the association between alcohol outlet density and adolescent alcohol use. Elasticity modelling identified a 10% increase in overall density at wave one was associated with an approximately 17% increase in odds of adolescent alcohol consumption at wave two. Living in areas with a higher density of outlets was associated with a statistically significant increase in the likelihood of adolescents developing early age alcohol consumption.

Application of the Exradin W1 scintillator to determine Ediode 60017 and microDiamond 60019 correction factors for relative dosimetry within small MV and FFF fields.

In this work we use EBT3 film measurements at 10 MV to demonstrate the suitability of the Exradin W1 (plastic scintillator) for relative dosimetry within small photon fields. We then use the Exradin W1 to measure the small field correction factors required by two other detectors: the PTW unshielded Ediode 60017 and the PTW microDiamond 60019. We consider on-axis correction-factors for small fields collimated using MLCs for four different TrueBeam energies: 6 FFF, 6 MV, 10 FFF and 10 MV. We also investigate percentage depth dose and lateral profile perturbations. In addition to high-density effects from its silicon sensitive region, the Ediode exhibited a dose-rate dependence and its known over-response to low energy scatter was found to be greater for 6 FFF than 6 MV. For clinical centres without access to a W1 scintillator, we recommend the microDiamond over the Ediode and suggest that 'limits of usability', field sizes below which a detector introduces unacceptable errors, can form a practical alternative to small-field correction factors. For a dosimetric tolerance of 2% on-axis, the microDiamond might be utilised down to 10 mm and 15 mm field sizes for 6 MV and 10 MV, respectively.

3D calculation of radiation-induced second cancer risk including dose and tissue response heterogeneities.

PURPOSE: Tools for comparing relative induced second cancer risk, to inform choice of radiotherapy treatment plan, are becoming increasingly necessary as the availability of new treatment modalities expands. Uncertainties, in both radiobiological models and model parameters, limit the confidence of such calculations. The aim of this study was to develop and demonstrate a software tool to produce a malignant induction probability (MIP) calculation which incorporates patient-specific dose and allows for the varying responses of different tissue types to radiation. METHODS: The tool has been used to calculate relative MIPs for four different treatment plans targeting a subtotally resected meningioma: 3D conformal radiotherapy (3DCFRT), volumetric modulated arc therapy (VMAT), intensity-modulated x-ray therapy (IMRT), and scanned protons. RESULTS: Two plausible MIP models, with considerably different dose-response relationships, were considered. A fractionated linear-quadratic induction and cell-kill model gave a mean relative cancer risk (normalized to 3DCFRT) of 113% for VMAT, 16% for protons, and 52% for IMRT. For a linear no-threshold model, these figures were 105%, 42%, and 78%, respectively. The relative MIP between plans was shown to be significantly more robust to radiobiological parameter uncertainties compared to absolute MIP. Both models resulted in the same ranking of modalities, in terms of MIP, for this clinical case. CONCLUSIONS: The results demonstrate that relative MIP is a useful metric with which treatment plans can be ranked, regardless of parameter- and model-based uncertainties. With further validation, this metric could be used to discriminate between plans that are equivalent with respect to other planning priorities.

The relationship between the density of alcohol outlets and parental supply of alcohol to adolescents.

This study investigated whether the number of alcohol outlets per 10,000 population in a given area (density) influenced parental supply of alcohol to adolescents; differences in Australian born and acculturating parents were also examined. A state-representative student survey in Victoria identified that the majority of adolescents (55%) reported that they had used alcohol in the past 12months; 34 % of those who had consumed alcohol reported that it had been supplied by their parents. Multilevel modelling identified that there were no overall effects of density, however there were different effects based on parent country of birth and type of license. Specifically, each unit increase in the density of takeaway liquor stores increased the likelihood by 2.03 that children with both Australian-born parents would be supplied alcohol. Adolescents with both migrant parents on the other hand, had a 1.36 increased risk of being supplied alcohol as the density of outlets requiring at-venue consumption increased. The findings of this study suggest that in Australia, alcohol outlet density is associated with parental supply of alcohol to children, with this effect moderated by the cultural background of the parent and type of outlet density. Future research should investigate the association between the density of alcohol outlets and public approval of parents supplying alcohol to adolescents.

Associations between alcohol outlet densities and adolescent alcohol consumption: a study in Australian students.

OBJECTIVE: To assess whether the density of alcohol sales outlets in specific geographic communities is associated with adolescent alcohol consumption. METHOD: A cross-sectional representative sample of secondary school students from Victoria, Australia (N=10,143), aged between 12 and 17 years, self-reported on alcohol use in the last 30 days in 2009. The density of alcohol outlets per local community area was merged with this information. RESULTS: After controlling for risk factors, multilevel modelling (MLM) revealed a statistical interaction between age and density on alcohol consumption. While older adolescents had higher alcohol consumption, increases in the density of alcohol outlets were only significantly associated with increased risk of alcohol consumption for adolescents between the ages of 12 and 14. CONCLUSION: Increased alcohol availability was associated with an increased risk of alcohol consumption specifically for early adolescents (12 and 14 years). Potential mechanisms as to how density is associated with direct and indirect alcohol availability, such as through parents or older siblings, need to be explored in future research.

Treatment of athletic tendonopathy.

Tendinopathy is a general term that describes any painful condition that occurs in or around a tendon. Historically, treatments have been directed at inflammation, but an improved understanding of the pathophysiology of tendinopathy has led to redirecting the treatment toward methods that address the underlying pathophysiology. Anti-inflammatory treatments such as NSAIDs and corticosteroid injections are still in common use. Novel treatments such as topical nitrates and platelet rich plasma injections aim to address the biological changes seen in tendinopathy, but evidence of clinical benefit is scant. This article reviews the most widely used treatments for tendinopathy and outlines the literature support for their use.

Hebbian mechanisms help explain development of multisensory integration in the superior colliculus: a neural network model.

The superior colliculus (SC) integrates relevant sensory information (visual, auditory, somatosensory) from several cortical and subcortical structures, to program orientation responses to external events. However, this capacity is not present at birth, and it is acquired only through interactions with cross-modal events during maturation. Mathematical models provide a quantitative framework, valuable in helping to clarify the specific neural mechanisms underlying the maturation of the multisensory integration in the SC. We extended a neural network model of the adult SC (Cuppini et al., Front Integr Neurosci 4:1-15, 2010) to describe the development of this phenomenon starting from an immature state, based on known or suspected anatomy and physiology, in which: (1) AES afferents are present but weak, (2) Responses are driven from non-AES afferents, and (3) The visual inputs have a marginal spatial tuning. Sensory experience was modeled by repeatedly presenting modality-specific and cross-modal stimuli. Synapses in the network were modified by simple Hebbian learning rules. As a consequence of this exposure, (1) Receptive fields shrink and come into spatial register, and (2) SC neurons gained the adult characteristic integrative properties: enhancement, depression, and inverse effectiveness. Importantly, the unique architecture of the model guided the development so that integration became dependent on the relationship between the cortical input and the SC. Manipulations of the statistics of the experience during the development changed the integrative profiles of the neurons, and results matched well with the results of physiological studies.

Scheduled cesarean delivery and the prevention of human immunodeficiency virus transmission: a survey of practicing obstetricians.

OBJECTIVE: To characterize practice patterns among obstetrician-gynecologists with respect to delivery for human immunodeficiency virus (HIV)-seropositive women, following publication of the 1999 American College of Obstetricians and Gynecologists (ACOG) Committee Opinion regarding scheduled cesarean delivery for HIV-infected patients. METHODS: A 25-question, multiple-choice survey was mailed to 2000 randomly selected obstetrician-gynecologists: 1000 maternal-fetal medicine specialists and 1000 general obstetrician-gynecologists. Mailing addresses were obtained from the 1999-2000 editions of the Society for Maternal-Fetal Medicine (SMFM) and ACOG membership directories. Information was requested about general perceptions of the 1999 ACOG Committee Opinion and about practice patterns with respect to management of HIV disease in pregnancy. Data were analyzed by using descriptive statistics and the chi-square test. Any P values <.05 were considered significant. RESULTS: After a single mailing we received 512 responses (25.6%), including 433 (43%) from SMFM members and 79 (8%) from ACOG members. Among the respondents, 47% disagreed with the current scientific validity of the 1999 ACOG Committee Opinion recommendation to offer cesarean delivery to all HIV-seropositive pregnant women. No statistically significant differences were detected in the demographic profiles, years of experience, or practice settings of participants who agreed with the scientific validity when compared to those who did not. Most respondents used viral load detection (87%) monitored on a trimester basis (67%) for clinical management decisions. Most practitioners (72%) do not recommend cesarean delivery for women who are compliant with antiretroviral therapy and who have undetectable viral loads regardless of CD4 counts. However, most practitioners (67%) do recommend cesarean delivery for those compliant women with detectable viral loads, irrespective of CD4 counts (67%). CONCLUSIONS: There is considerable disagreement among practicing obstetricians with respect to the 1999 ACOG Committee Opinion recommendation to offer cesarean delivery to all HIV-seropositive women. Most physicians use viral load detection to assist with the counseling in delivery options for HIV-infected pregnant women.

Direct and indirect regulation of cytokine and cell cycle proteins by EBNA-2 during Epstein-Barr virus infection.

We have studied the pathways of regulation of cytokine and cell cycle control proteins during infection of human B lymphocytes by Epstein-Barr virus (EBV). Among 30 cytokine RNAs analyzed by the RNase protection assay, tumor necrosis factor alpha (TNF-alpha), granulocyte colony-stimulating factor, lymphotoxin (LT), and LTbeta were found to be regulated within 20 h of EBV infection of primary B cells. Similar results were obtained using the estrogen-regulated EBNA-2 cell line EREB2.5, in which RNAs for LT and TNF-alpha were induced within 6 h of activation of EBNA-2. Expression of Notch also caused an induction of TNF-alpha RNA. The induction of TNF-alpha RNA by EBNA-2 was indirect, and constitutive expression of either LMP-1 or c-myc proteins did not substitute for EBNA-2 in induction of TNF-alpha RNA. Cyclin D2 is also an indirect target of EBNA-2-mediated transactivation. EBNA-2 was found to activate the cyclin D2 promoter in a transient-transfection assay. A mutant of EBNA-2 that does not bind RBP-Jkappa retained some activity in this assay, and activation did not depend on the presence of B-cell-specific factors. Deletion analysis of the cyclin D2 promoter revealed that removal of sequences containing E-box c-myc consensus DNA binding sequences did not reduce EBNA-2-mediated activation of the cyclin D2 promoter in the transient-transfection assay. The results indicate that cytokines are an early target of EBNA-2 and that EBNA-2 can regulate cyclin D2 transcription in EBV-infected cells by mechanisms additional to the c-myc pathway.

Elevated circulating concentrations of platelet activating factor in preeclampsia.

OBJECTIVE: The aim of this study was to determine whether any association exists between preeclampsia and circulating platelet activating factor levels. STUDY DESIGN: We performed a cross-sectional observational study of circulating platelet activating factor concentrations in nonpregnant women, normotensive pregnant women in the third trimester, women with preeclampsia in the third trimester, and normotensive men. Platelet activating factor concentrations were measured with a commercially available platelet activating factor-specific radioimmunoassay (NEN Life Science Products, Inc, Boston, Mass). The primary outcome measure was the difference in mean platelet activating factor concentrations among the 4 study groups. Preeclampsia was determined according to the criteria of The American College of Obstetricians and Gynecologists. Data were analyzed with the Student t test, the chi(2) test, the Fisher exact test, analysis of variance, and the Tukey test for pairwise multiple comparisons, with significance established at P <.05. RESULTS: The mean (+/-SD) circulating concentration of platelet activating factor was significantly higher in the group with preeclampsia (338.1 +/- 26.9 ng/mL) than in either the normotensive pregnant group (217.9 +/- 25.9 ng/mL; P <.05) or the nonpregnant female group (237.9 +/- 20.9 ng/mL; P <.05). The 2 pregnant groups were similar with respect to selected demographic characteristics and gestational age at time of collection. There were no significant differences in the mean platelet activating factor concentrations between the group with preeclampsia and the normotensive male group or between the normotensive pregnant female group and the nonpregnant female group. CONCLUSION: Circulating platelet activating factor concentrations were increased in women with pregnancies complicated by preeclampsia with respect to those in normotensive pregnant women and normotensive nonpregnant women. Platelet activating factor may therefore serve as a marker for the risk of preeclampsia.

Fluorescence-based detection of lacZ reporter gene expression in intact and viable bacteria including Mycobacterium species.

A variety of fluorescein di-beta-D-galactopyranoside (FDG)-based substrates were evaluated for measuring beta-galactosidase expression in bacteria. One substrate, 5-acetylamino-FDG (C2FDG), performed well in all bacteria tested, including the slow growing mycobacterium, Mycobacterium bovis BCG. The sensitivity of C2FDG in intact, viable BCG was similar to that of o-nitrophenyl-beta-D-galactopyranoside in cell lysates when used to measure lacZ reporter gene activity. C2FDG was approximately 70-fold more sensitive than green fluorescent protein (GFP) in BCG when assayed in a fluorescence plate reader, and comparable to GFP when measured by flow cytometry. These assays provide an important new alternative for the rapid measurement of reporter gene expression in viable bacteria.

Sequence and genetic organization of a Bacillus subtilis operon encoding 2,3-dihydroxybenzoate biosynthetic enzymes.

Under iron-limiting conditions, Bacillus subtilis (Bs) produces the siderophore 2,3-dihydroxybenzoate (DHB) to acquire extracellular iron. In Escherichia coli (Ec), DHB is a precursor of the siderophore enterobactin, which suggested that Bs may possess similar biosynthetic enzymes. The sequences of two overlapping Bs clones capable of complementing Ec enterobactin mutants [Grossman, T.H., Tuckman, M., Ellestad, S. and Osburne, M.S. (1993) Isolation and characterization of Bacillus subtilis genes involved in siderophore biosynthesis: Relationship between B. subtilis sfpo and Escherichia coli entD genes. J. Bacteriol. 175, 6203-6211] were analyzed and five open reading frames were identified. These genes are located near 291 degrees on the Bs chromosome and have been termed dhbA, dhbC, dhbE, dhbB and dhbF, based on similarities to Ec ent homologs. Amino-acid identities between gene product homologs are: EntA and DhbA, 41%; EntC and DhbC, 35%; EntE and DhbE, 48%; EntB and DhbB, 54%; and EntF and DhbF, 29%. DhbC is also 35% identical to the Bs menaquinone-specific isochorismate synthase, MenF, illustrating an example of gene duplication. Operon disruption studies suggested that the dhb genes comprise an operon of at least four genes.