The contribution of dormant origins to genome stability:from cell biology to human genetics

AbstractThe ability of a eukaryotic cell to precisely and accurately replicate its DNA is crucial to maintain genome stability. Here we describe our current understanding of the process by which origins are licensed for DNA replication and review recent work suggesting that fork stalling has exerted a strong selective pressure on the positioning of licensed origins. In light of this, we discuss the complex and disparate phenotypes observed in mouse models and humans patients that arise due to defects in replication licensing proteins

Treatment of Older Women With Alcohol Problems: Meeting the Challenge for a Special Population

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65642/1/j.1530-0277.2000.tb02092.x.pd

Dilemmas and solutions- experiences of a national Family Medicine applied knowledge licensing test during a pandemic

ABSTRACT: Background: The unprecedented COVID-19 pandemic brought significant challenges to all of medicine, including primary care training and examinations. The MRCGP AKT is high-stakes licensing 200-item MCQ for UK trainee family physicians and is part of an assessment tripos that, up to the onset of the pandemic, included a Clinical Skills Assessment using Simulated Patients and workplace based assessment. The AKT is blueprinted onto a curriculum content specification and computer delivered three times a year at test centres across the UK. It tests the knowledge base underpinning independent general practice within the context of the UK National Health Service. We report on the challenges and dilemmas faced during the pandemic, decisions taken, and lessons learned. Rapid exam changes needed to be made, and communicated effectively to candidates, whilst maintaining standards and fairness to candidates. Summary of Work: Challenges included lockdown travel restrictions, reduced capacity, social distancing and shielding candidates being unable to leave home. The April 2020 AKT was cancelled and prioritisation measures implemented to ensure candidates at the end of their training could enter the (stressed) workforce. We engaged with a wide range of stakeholders, carefully looked at remote testing, made contingency plans prioritised for those unable to sit exams and changed exam regulations to ensure fairness to candidates. In this emergency, we delivered a previously published exam which some candidates were unaware they had sat previously, and assessed how these candidates performed. We compared cohort performance before and during the pandemic. Summary of Results: We summarise why we did not remote test, how we obtained key worker status, and adapted contingency plans. Analysis of candidates who had previously sat the same exam showed they performed less well. Despite wide-ranging changes in training and workplace experience, there was no significant difference in cohort performance overall pre-and peri-pandemic. Discussion and Conclusions: COVID-19 constraints changed trainees clinical exposure, restricted training and supervisor support. However, exam preparedness did not appear adversely affected when measured by overall pass rates. Unexpectedly, candidates who sat an identical exam did not benefit from previous exposure. Take-home Messages: Involving stakeholders in key decisions and regular communications are essential. Test security and standards were not compromised

Young-adult children of alcoholic parents: protective effects of positive family functioning

The occurrence of alcoholism is clustered within families, but the detrimental effect of a positive family history may vary with the degree of family impairment involved. In this study we assessed the effects of family history and family environment on alcohol misuse. From ongoing studies we recruited parents who had a child aged 18–30, 20 with a DSM-III-R alcohol dependence diagnosis, 20 without. The child then completed a multidimensional assessment. The young-adult participants included 20 men and 20 women (mean age=24.8). Differences by family history were restricted to substance abuse behaviors. While a high level of alcohol problems occurred in both groups, those with an alcohol-dependent parent were more likely to be heavy drinkers and showed more symptoms of alcohol dependence. Overall psychological adjustment did not differ between the groups, however. Alcohol misuse measures did correlate moderately with symptoms of poor emotional health. The most important correlates of alcohol misuse measures in this study were exposure to parental alcoholism, abusive punishment, and psychological symptoms, with some separation of effects in the two subgroups. Psychological symptoms had a stronger relationship with misuse in subjects with social-drinking parents, while abuse was more associated in the group with an alcohol-dependent parent. These results confirm the importance of environmental interactions with familial risk. A biological vulnerability from an alcohol-dependent parent was not sufficient or necessary for the participants in this study to develop alcohol dependence as a young adult, although there was an increased risk. There appear to be strong protective effects of positive family relationships on the potential negative effects of a family history of alcoholism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73415/1/j.1360-0443.1992.tb02681.x.pd

Role of Alcohol in Late-Life Suicide

Suicide is among the leading causes of death in the United States, ranking 10th to 12th annually, depending on the year. Rates of suicide increase markedly among Americans over age 75, especially among white men. After age 85, rates are >5-fold higher in this group than in the general population. The relationship between alcohol use and later-life suicide is complex and currently ill defined. Substance use disorders, particularly alcohol abuse and dependence, are the second most common category of axis I disorders associated with completed suicide among adults aged 65 and older, following only depression. The co-occurrence of alcohol use disorders and depression heightens suicide risk. Most studies that have evaluated the effects of alcohol in geriatric suicide have focused on older adults who met DSM criteria for abuse and/or dependence. However, the majority of older adults who are experiencing problems related to their alcohol use do not meet alcohol abuse/dependence criteria. Therefore, the role of at-risk and problem alcohol use in geriatric suicide may be underestimated. Drinking among elders elevates suicide risk through interactions with other factors that are more prevalent in this age group, such as depressive symptoms, medical illness, negatively perceived health status, and low social support. This article reviews the literature related to alcohol use and suicide among older adults. Clinical and research recommendations for addressing this problem are also presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65936/1/j.1530-0277.2004.tb03603.x.pd

Prevalence and Severity of Alcohol and Cannabis Use Across the Urban‐Rural Continuum in the Michigan National Guard

PurposeThe National Guard provides critical support both domestically and abroad with soldiers dispersed throughout America and spanning the urban‐rural continuum. To determine if location‐specific interventions may be needed, we compared the prevalence and severity of cannabis and alcohol use among National Guard members across localities.MethodsMichigan National Guard members were enrolled (N = 2,746) during drill weekends as part of a larger randomized behavioral trial. Cannabis (ASSIST; prevalence = 5%) and alcohol use (AUDIT; prevalence = 82%) were compared using hurdle regression models across locality status after adjusting for covariates.FindingsPrevalence of cannabis and alcohol use was predicted by locality (adjusted odds ratio [AOR] = 0.913, 95% CI: 0.838‐0.986, P = .029; AOR = 0.963, 95% CI: 0.929‐0.998, P = .038, respectively), with more use in urban localities. Neither severity of cannabis nor alcohol use was predicted by locality status.ConclusionsPrevalence of cannabis and alcohol use in the National Guard is differentially elevated across localities with higher prevalence in more central, densely populated areas. Findings may inform future work considering accessibility and utilization of prevention and treatment services for Guard members across the urban‐rural continuum.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154619/1/jrh12412.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154619/2/jrh12412_am.pd

Injury Type, Injury Severity, and Repeat Occurrence of Alcohol-Related Trauma in Adolescents

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66113/1/j.1530-0277.1994.tb00011.x.pd

Reversal of DDK-mediated MCM phosphorylation by Rif1-PP1 regulates replication initiation and replisome stability independently of ATR/Chk1

Dbf4-dependent kinases (DDKs) are required for the initiation of DNA replication, their essential targets being the MCM2-7 proteins. We show that, in Xenopus laevis egg extracts and human cells, hyper-phosphorylation of DNA-bound Mcm4, but not phosphorylation of Mcm2, correlates with DNA replication. These phosphorylations are differentially affected by the DDK inhibitors PHA-767491 and XL413. We show that DDK-dependent MCM phosphorylation is reversed by protein phosphatase 1 (PP1) targeted to chromatin by Rif1. Loss of Rif1 increased MCM phosphorylation and the rate of replication initiation and also compromised the ability of cells to block initiation when challenged with replication inhibitors. We also provide evidence that Rif1 can mediate MCM dephosphorylation at replication forks and that the stability of dephosphorylated replisomes strongly depends on Chk1 activity. We propose that both replication initiation and replisome stability depend on MCM phosphorylation, which is maintained by a balance of DDK-dependent phosphorylation and Rif1-mediated dephosphorylation

Evaluation of Lysis Methods for the Extraction of Bacterial DNA for Analysis of the Vaginal Microbiota

BACKGROUND:Recent studies on the vaginal microbiota have employed molecular techniques such as 16S rRNA gene sequencing to describe the bacterial community as a whole. These techniques require the lysis of bacterial cells to release DNA before purification and PCR amplification of the 16S rRNA gene. Currently, methods for the lysis of bacterial cells are not standardised and there is potential for introducing bias into the results if some bacterial species are lysed less efficiently than others. This study aimed to compare the results of vaginal microbiota profiling using four different pretreatment methods for the lysis of bacterial samples (30 min of lysis with lysozyme, 16 hours of lysis with lysozyme, 60 min of lysis with a mixture of lysozyme, mutanolysin and lysostaphin and 30 min of lysis with lysozyme followed by bead beating) prior to chemical and enzyme-based DNA extraction with a commercial kit. RESULTS:After extraction, DNA yield did not significantly differ between methods with the exception of lysis with lysozyme combined with bead beating which produced significantly lower yields when compared to lysis with the enzyme cocktail or 30 min lysis with lysozyme only. However, this did not result in a statistically significant difference in the observed alpha diversity of samples. The beta diversity (Bray-Curtis dissimilarity) between different lysis methods was statistically significantly different, but this difference was small compared to differences between samples, and did not affect the grouping of samples with similar vaginal bacterial community structure by hierarchical clustering. CONCLUSIONS:An understanding of how laboratory methods affect the results of microbiota studies is vital in order to accurately interpret the results and make valid comparisons between studies. Our results indicate that the choice of lysis method does not prevent the detection of effects relating to the type of vaginal bacterial community one of the main outcome measures of epidemiological studies. However, we recommend that the same method is used on all samples within a particular study