A Brief Mind-body Intervention Is Feasible and May Prevent Persistent Pain After Acute Orthopaedic Traumas: A Randomized Controlled Trial.

BACKGROUND: Approximately 20% to 50% of patients develop persistent pain after traumatic orthopaedic injuries. Psychosocial factors are an important predictor of persistent pain; however, there are no evidence-based, mind-body interventions to prevent persistent pain for this patient population. QUESTIONS/PURPOSES: (1) Does the Toolkit for Optimal Recovery after Injury (TOR) achieve a priori feasibility benchmarks in a multisite randomized control trial (RCT)? (2) Does TOR demonstrate a preliminary effect in improving pain, as well as physical and emotional function? METHODS: This pilot RCT of TOR versus a minimally enhanced usual care comparison group (MEUC) was conducted among 195 adults with an acute orthopaedic traumatic injury at risk for persistent pain at four geographically diverse Level 1 trauma centers between October 2021 to August 2023. Fifty percent (97 of 195) of participants were randomized to TOR (mean age 43 ± 17 years; 67% [65 of 97] women) and 50% (98) to MEUC (mean age 45 ± 16 years; 67% [66 of 98] women). In TOR, 24% (23 of 97) of patients were lost to follow-up, whereas in the MEUC, 17% (17 of 98) were lost. At 4 weeks, 78% (76 of 97) of patients in TOR and 95% (93 of 98) in the MEUC completed the assessments; by 12 weeks, 76% (74 of 97) of patients in TOR and 83% (81 of 98) in the MEUC completed the assessments (all participants were still included in the analysis consistent with an intention-to-treat approach). The TOR has four weekly video-administered sessions that teach pain coping skills. The MEUC is an educational pamphlet. Both were delivered in addition to usual care. Primary outcomes were feasibility of recruitment (the percentage of patients who met study criteria and enrolled) and data collection, appropriateness of treatment (the percent of participants in TOR who score above the midpoint on the Credibility and Expectancy Scale), acceptability (the percentage of patients in TOR who attend at least three of four sessions), and treatment satisfaction (the percent of participants in TOR who score above the midpoint on the Client Satisfaction Scale). Secondary outcomes included additional feasibility (including collecting data on narcotics and rescue medications and adverse events), fidelity (whether the intervention was delivered as planned) and acceptability metrics (patients and staff), pain (numeric rating scale), physical function (Short Musculoskeletal Function Assessment questionnaire [SMFA], PROMIS), emotional function (PTSD [PTSD Checklist], depression [Center for Epidemiologic Study of Depression]), and intervention targets (pain catastrophizing, pain anxiety, coping, and mindfulness). Assessments occurred at baseline, 4 and 12 weeks. RESULTS: Several outcomes exceeded a priori benchmarks: feasibility of recruitment (89% [210 of 235] of eligible participants consented), appropriateness (TOR: 73% [66 of 90] scored > midpoint on the Credibility and Expectancy Scale), data collection (79% [154 of 195] completed all surveys), satisfaction (TOR: 99% [75 of 76] > midpoint on the Client Satisfaction Scale), and acceptability (TOR: 73% [71 of 97] attended all four sessions). Participation in TOR, compared with the MEUC, was associated with improvement from baseline to postintervention and from baseline to follow-up in physical function (SMFA, baseline to post: -7 [95% CI -11 to -4]; p < 0.001; baseline to follow-up: -6 [95% CI -11 to -1]; p = 0.02), PROMIS (PROMIS-PF, baseline to follow-up: 2 [95% CI 0 to 4]; p = 0.045), pain at rest (baseline to post: -1.2 [95% CI -1.7 to -0.6]; p < 0.001; baseline to follow-up: -1 [95% CI -1.7 to -0.3]; p = 0.003), activity (baseline to post: -0.7 [95% CI -1.3 to -0.1]; p = 0.03; baseline to follow-up: -0.8 [95% CI -1.6 to -0.1]; p = 0.04), depressive symptoms (baseline to post: -6 [95% CI -9 to -3]; p < 0.001; baseline to follow-up: -5 [95% CI -9 to -2]; p < 0.002), and posttraumatic symptoms (baseline to post: -4 [95% CI -7 to 0]; p = 0.03; baseline to follow-up: -5 [95% CI -9 to -1]; p = 0.01). Improvements were generally clinically important and sustained or continued through the 3 months of follow-up (that is, above the minimum clinically important different [MCID] of 7 for the SMFA, the MCID of 3.6 for PROMIS, the MCID of 2 for pain at rest and pain during activity, the MCID of more than 10% change in depressive symptoms, and the MCID of 10 for posttraumatic symptoms). There were treatment-dependent improvements in pain catastrophizing, pain anxiety, coping, and mindfulness. CONCLUSION: TOR was feasible and potentially efficacious in preventing persistent pain among patients with an acute orthopaedic traumatic injury. Using TOR in clinical practice may prevent persistent pain after orthopaedic traumatic injury. LEVEL OF EVIDENCE: Level I, therapeutic study.

The influence of patients' beliefs about medicines and the relationship with suboptimal medicine use in community-dwelling older adults: a systematic review of quantitative studies.

BACKGROUND: Medication use in older adults is increasing, therefore, reducing the risk of suboptimal medicine use is imperative in achieving optimal therapeutic outcomes. Research suggests that factors such as personal beliefs and beliefs about medicines may be associated with non-adherence and inappropriate medicine use. AIM: To systematically review and identify quantitative research on the influence of beliefs about medicines and the relationship with suboptimal medicine use in older adults. METHOD: Searches were conducted on PubMed, EMBASE, CINAHL, and PsycINFO for quantitative studies (inception to March 2023). INCLUSION CRITERIA: (1) exposure: participants' beliefs (personal, cultural, and medication-related), (2) outcomes: polypharmacy, potentially inappropriate medicines use, or non-adherence, and (3) participants: community-dwelling adults 65 years or above. Study selection, data extraction and quality appraisal (Joanna Briggs Institute critical appraisal checklist) were completed independently by two investigators. Data were combined in a narrative synthesis and presented in a summary of findings table. RESULTS: Nineteen articles were included: 15 cross-sectional and four cohort studies. Outcomes of included papers were as follows; adherence (n = 18) and potentially inappropriate medicine use (n = 1). Ten studies found stronger beliefs in the necessity of medicines and/or fewer concerns led to better adherence, with one paper contradicting these findings. Three studies did not find associations between adherence and beliefs. One study confirmed an association between unnecessary drug use and a lack of belief in a "powerful other" (e.g. doctor). CONCLUSION: Further investigation is necessary to (1) ascertain the importance of necessity or concern beliefs in fostering adherence and, (2) examine the influence of beliefs on polypharmacy and inappropriate medicine use.

Diversity and Molecular Evolution of Nonvisual Opsin Genes across Environmental, Developmental, and Morphological Adaptations in Frogs.

Nonvisual opsins are transmembrane proteins expressed in the eyes and other tissues of many animals. When paired with a light-sensitive chromophore, nonvisual opsins form photopigments involved in various nonvisual, light-detection functions including circadian rhythm regulation, light-seeking behaviors, and seasonal responses. Here, we investigate the molecular evolution of nonvisual opsin genes in anuran amphibians (frogs and toads). We test several evolutionary hypotheses including the predicted loss of nonvisual opsins due to nocturnal ancestry and potential functional differences in nonvisual opsins resulting from environmental light variation across diverse anuran ecologies. Using whole-eye transcriptomes of 81 species, combined with genomes, multitissue transcriptomes, and independently annotated genes from an additional 21 species, we identify which nonvisual opsins are present in anuran genomes and those that are also expressed in the eyes, compare selective constraint among genes, and test for potential adaptive evolution by comparing selection between discrete ecological classes. At the genomic level, we recovered all 18 ancestral vertebrate nonvisual opsins, indicating that anurans demonstrate the lowest documented amount of opsin gene loss among ancestrally nocturnal tetrapods. We consistently found expression of 14 nonvisual opsins in anuran eyes and detected positive selection in a subset of these genes. We also found shifts in selective constraint acting on nonvisual opsins in frogs with differing activity periods, habitats, distributions, life histories, and pupil shapes, which may reflect functional adaptation. Although many nonvisual opsins remain poorly understood, these findings provide insight into the diversity and evolution of these genes across anurans, filling an important gap in our understanding of vertebrate opsins and setting the stage for future research on their functional evolution across taxa.

HIV-1 Capsid Rapidly Induces Long-Lived CPSF6 Puncta in Non-Dividing Cells, but Similar Puncta Already Exist in Uninfected T-Cells.

The HIV-1 capsid (CA) protein forms the outer shell of the viral core that is released into the cytoplasm upon infection. CA binds various cellular proteins, including CPSF6, that direct HIV-1 integration into speckle-associated domains in host chromatin. Upon HIV-1 infection, CPSF6 forms puncta in the nucleus. Here, we characterised these CPSF6 puncta further in HeLa cells, T-cells and macrophages and confirmed that integration and reverse transcription are not required for puncta formation. Indeed, we found that puncta formed very rapidly after infection, correlating with the time that CA entered the nucleus. In aphidicolin-treated HeLa cells and macrophages, puncta were detected for the length of the experiment, suggesting that puncta are only lost upon cell division. CA still co-localised with CPSF6 puncta at the latest time points, considerably after the peak of reverse transcription and integration. Intriguingly, the number of puncta induced in macrophages did not correlate with the MOI or the total number of nuclear speckles present in each cell, suggesting that CA/CPSF6 is only directed to a few nuclear speckles. Furthermore, we found that CPSF6 already co-localised with nuclear speckles in uninfected T-cells, suggesting that HIV-1 promotes a natural behaviour of CPSF6.

A Mind-Body Intervention to Improve Physical Activity for Patients with Chronic Hip-Related Pain: Protocol for a Mixed Methods Study.

BACKGROUND: Pain and dysfunction persist for most patients following hip-related pain treatment. Additionally, individuals with hip-related pain are typically less physically active than individuals without hip pain, despite evidence that regular physical activity reduces chronic musculoskeletal pain. Poor psychological health is common in patients with hip-related pain and further reinforces low physical activity. Mind-body interventions can improve psychological health and activity levels but have yet to be integrated to provide comprehensive, psychologically informed care for patients with hip-related pain. Thus, we are using the NCCIH intervention development framework to develop Helping Improve PSychological Health (HIPS), a novel, multimodal mind-body intervention to improve physical activity for individuals with hip-related pain and poor psychological health. METHODS: We will recruit physical therapists (N = 20) and patients with hip-related pain (N = 20) to participate in 60 min qualitative interviews (focus groups with therapists; one-on-one interviews with patients). Using these data, we will develop the initial HIPS intervention and provider training materials. One physical therapist will be trained to deliver the HIPS intervention to five participants in an open pilot trial. Participants will attend six 30 min HIPS intervention sessions. We will collect quantitative data on satisfaction, improvement, and physical activity, alongside qualitative exit interviews with participants and the physical therapist in order to refine the HIPS intervention and provider training materials. RESULTS: This study has been approved by the MGB IRB. We aim to develop and test the initial feasibility of the HIPS intervention in an open pilot trial. The findings from this project will inform a subsequent feasibility RCT.

Diversity and Evolution of Frog Visual Opsins: Spectral Tuning and Adaptation to Distinct Light Environments.

Visual systems adapt to different light environments through several avenues including optical changes to the eye and neurological changes in how light signals are processed and interpreted. Spectral sensitivity can evolve via changes to visual pigments housed in the retinal photoreceptors through gene duplication and loss, differential and coexpression, and sequence evolution. Frogs provide an excellent, yet understudied, system for visual evolution research due to their diversity of ecologies (including biphasic aquatic-terrestrial life cycles) that we hypothesize imposed different selective pressures leading to adaptive evolution of the visual system, notably the opsins that encode the protein component of the visual pigments responsible for the first step in visual perception. Here, we analyze the diversity and evolution of visual opsin genes from 93 new eye transcriptomes plus published data for a combined dataset spanning 122 frog species and 34 families. We find that most species express the four visual opsins previously identified in frogs but show evidence for gene loss in two lineages. Further, we present evidence of positive selection in three opsins and shifts in selective pressures associated with differences in habitat and life history, but not activity pattern. We identify substantial novel variation in the visual opsins and, using microspectrophotometry, find highly variable spectral sensitivities, expanding known ranges for all frog visual pigments. Mutations at spectral-tuning sites only partially account for this variation, suggesting that frogs have used tuning pathways that are unique among vertebrates. These results support the hypothesis of adaptive evolution in photoreceptor physiology across the frog tree of life in response to varying environmental and ecological factors and further our growing understanding of vertebrate visual evolution.

Health care utilization and the associated costs attributable to cardiovascular disease in Ireland: a cross-sectional study.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality and disability globally. We examined healthcare service utilization and costs attributable to CVD in Ireland in the period before the introduction of a major healthcare reform in 2016. METHODS: Secondary analysis of data from 8 113 participants of the first wave of The Irish Longitudinal Study on Ageing. CVD was defined as having a self-reported doctor's diagnosis of myocardial infarction, angina, heart failure, stroke, atrial fibrillation or transient ischaemic attack. Participants self-reported the utilization of healthcare services in the year preceding the interview. Negative binomial regression with average marginal effects (AME) was used to estimate the incremental number of general practitioner (GP) and outpatient department (OPD) visits, accident and emergency department attendances and hospitalisations in population with CVD relative to population without CVD. We calculated the corresponding costs at individual and population levels, by gender and age groups. RESULTS: The prevalence of CVD was 18.2% (95% CI: 17.3, 19.0) Participants with CVD reported higher utilization of all healthcare services. In adjusted models, having CVD was associated with incremental 1.19 (95% CI: 0.99, 1.39) GP and 0.79 (95% CI: 0.65, 0.93) OPD visits. There were twice as many incremental hospitalisations in males with CVD compared to females with CVD (AME (95% CI): 0.20 (0.16, 0.23) vs 0.10 (0.07, 0.14)). The incremental cost of healthcare service use in population with CVD was an estimated €352.2 million (95% CI: €272.8, €431.7), 93% of which was due to use of secondary care services. CONCLUSION: We identified substantially increased use of healthcare services attributable to CVD in Ireland. Continued efforts aimed at CVD primary prevention and management are required.

Development of a list of Australian potentially inappropriate medicines using the Delphi technique.

BACKGROUND: Older people are at high risk of medicines-related harms. otentially inappropriate medicines (PIMs) list has been developed to assist clinicians and researchers to identify medicines with risks that may potentially outweigh their benefits in order to improve medication management and safety. AIM: To develop a list of PIMs for older people specific to Australia. METHODS: The study obtained expert consensus through the utilisation of the Delphi technique in Australia. A total of 33 experts partook in the initial round, while 32 experts engaged in the subsequent round. The primary outcomes encompass medicines assessed as potentially inappropriate, the specific contexts in which their inappropriateness arises and potentially safer alternatives. RESULTS: A total of 16 medicines or medicine classes had one or more medicines deemed as potentially inappropriate in older people. Up to 19 medicines or medicine classes had specific conditions that make them more potentially inappropriate, while alternatives were suggested for 16 medicines or classes. CONCLUSION: An explicit PIMs list for older people living in Australia has been developed containing 19 drugs/drug classes. The PIMs list is intended to be used as a guide for clinicians when assessing medication appropriateness in older people in Australian clinical settings and does not substitute individualised treatment advice from clinicians.

Upper-Limb High-Intensity Interval Training or Passive Heat Therapy to Optimize Cardiorespiratory Fitness Prior to Total Hip or Knee Arthroplasty: A Randomized Controlled Trial.

OBJECTIVE: Preoperative exercise training, or prehabilitation, aims to optimize cardiorespiratory fitness before surgery to reduce the risk of adverse perioperative events and delayed recovery. However, traditional exercise such as walking and cycling can be difficult for people with degenerative joint diseases of the lower limbs, such as osteoarthritis. The purpose of this study was to compare the effect of three low-impact interventions on cardiorespiratory fitness, physical function, and subjective health before total hip or knee arthroplasty. METHODS: This was a randomized controlled trial involving 93 participants with severe knee or hip osteoarthritis awaiting joint replacement surgery. Participants underwent cardiopulmonary exercise testing (to measure peak oxygen consumption [ V ̇ $$ \dot{V} $$ O2 ]), then were randomized to heat therapy (Heat; 20-30 min immersed in 40°C water followed by ~15 min light-resistance exercise), high-intensity interval training (HIIT; 6-8 × 60 s intervals on a cross-trainer or arm ergometer at ~90%-100% peak V ̇ $$ \dot{V} $$ O2 ), or home-based exercise (Home; ~15 min light-resistance exercise); for up to 36 sessions (3 sessions per week for 12 weeks). RESULTS: Peak V ̇ $$ \dot{V} $$ O2 increased by 16% across HIIT and to a greater extent than Heat (+2.5 mL × min-1 × kg-1 [95% CI: 0.5-4.4], P = 0.009) and Home (+3.2 mL × min-1 × kg-1 [1.2-5.2], P = 0.001). The anaerobic threshold increased across HIIT (+1.5 mL × min-1 × kg-1 [0.7-2.3], P < 0.001) and Heat (+1.2 mL × min-1 × kg-1 [0.4-1.9], P = 0.004), but not Home (-0.5 mL × min-1 × kg-1 [-1.3 to 0.3], P = 0.248). Subjective severity of osteoarthritis was unchanged with any intervention (P ≥ 0.250). CONCLUSION: Heat therapy and HIIT improved indices of cardiorespiratory fitness preoperatively in patients who have difficulty performing lower-limb exercise.

Bidirectional perforators in the lower limb are not physiologically normal: A brief commentary.

The suggestion that bidirectional flow is a normal feature seen in venous perforators of the lower leg has been a longstanding debate. Newer published evidence has changed the perspective on normal perforator flow and is presented here to resolve the misunderstandings and different viewpoints previously held.

Arthritis Foundation/HSS Workshop on Hip Osteoarthritis, Part 3: Rehabilitation and Exercise.

Far more publications are available for osteoarthritis of the knee than of the hip. Recognizing this research gap, the Arthritis Foundation (AF), in partnership with the Hospital for Special Surgery (HSS), convened an in-person meeting of thought leaders to review the state of the science of and clinical approaches to hip osteoarthritis. This article summarizes the recommendations gleaned from 5 presentations given on hip-related rehabilitation at the 2023 Hip Osteoarthritis Clinical Studies Conference, which took place on February 17 and 18, 2023, in New York City.

Childhood socioeconomic position and sex-specific trajectories of metabolic traits across early life: prospective cohort study.

BACKGROUND: Socioeconomic inequalities in cardiovascular disease risk begin early in life and are more pronounced in females than males later in life. Causal atherogenic traits explaining this are not well understood. We explored sex-specific associations between childhood socioeconomic position (SEP) and molecular measures of systemic metabolism across early life. METHODS: Data were from the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort in southwest England. Pregnant women with an expected delivery date between 1991 and 1992 were invited to participate. Maternal education was the primary indicator of SEP. Concentrations of 148 metabolic traits from targeted metabolomics (nuclear magnetic resonance spectroscopy) from research clinics at ages 7, 15, 18 and 25 years were analysed. The sex-specific slope index of inequality (SII) in trajectories of metabolic traits was estimated using multilevel models. FINDINGS: Total number of participants included was 6537 (12,543 repeated measures). Lower maternal education was associated with more adverse levels of several atherogenic lipids and key metabolic traits among females at age 7 years, but not males. For instance, SII for very small very-low-density lipoprotein (VLDL) concentrations was 0.16SD (95% CI: 0.01, 0.30) among females and -0.02SD (95% CI: -0.16, 0.13) among males. Between 7 and 25 years, inequalities widened among females and emerged among males particularly for VLDL particle concentrations, apolipoprotein-B concentrations, and inflammatory glycoprotein acetyls. For instance, at 25 years, SII for very small VLDL concentrations was 0.36SD (95% CI: 0.20, 0.52) and 0.22SD (95% CI: 0.04, 0.40) among females and males respectively. INTERPRETATION: Prevention of socioeconomic inequalities in cardiovascular disease risk requires a life course approach beginning at the earliest opportunity, especially among females. FUNDING: The UK Medical Research Council and Wellcome (grant ref: 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. A comprehensive list of grants funding is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). KON is supported by a Health Research Board (HRB) of Ireland Investigator Led Award (ILP-PHR-2022-008). JB, GDS and KT work in a unit funded by the UK MRC (MC_UU_00011/1 and MC UU 00011/3) and the University of Bristol. OR is supported by a UKRI Future Leaders Fellowship (MR/S03532X/1). These funding sources had no role in the design and conduct of this study. This publication is the work of the authors and KON will serve as guarantor for the contents of this paper.

Malignant and non-malignant oral lesions classification and diagnosis with deep neural networks.

OBJECTIVES: Given the increasing incidence of oral cancer, it is essential to provide high-risk communities, especially in remote regions, with an affordable, user-friendly tool for visual lesion diagnosis. This proof-of-concept study explored the utility and feasibility of a smartphone application that can photograph and diagnose oral lesions. METHODS: The images of oral lesions with confirmed diagnoses were sourced from oral and maxillofacial textbooks. In total, 342 images were extracted, encompassing lesions from various regions of the oral cavity such as the gingiva, palate, and labial mucosa. The lesions were segregated into three categories: Class 1 represented non-neoplastic lesions, Class 2 included benign neoplasms, and Class 3 contained premalignant/malignant lesions. The images were analysed using MobileNetV3 and EfficientNetV2 models, with the process producing an accuracy curve, confusion matrix, and receiver operating characteristic (ROC) curve. RESULTS: The EfficientNetV2 model showed a steep increase in validation accuracy early in the iterations, plateauing at a score of 0.71. According to the confusion matrix, this model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions was 64% and 80% respectively. Conversely, the MobileNetV3 model exhibited a more gradual increase, reaching a plateau at a validation accuracy of 0.70. The MobileNetV3 model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions, according to the confusion matrix, was 64% and 82% respectively. CONCLUSIONS: Our proof-of-concept study effectively demonstrated the potential accuracy of AI software in distinguishing malignant lesions. This could play a vital role in remote screenings for populations with limited access to dental practitioners. However, the discrepancies between the classification of images and the results of "non-malignant lesions" calls for further refinement of the models and the classification system used. CLINICAL SIGNIFICANCE: The findings of this study indicate that AI software has the potential to aid in the identification or screening of malignant oral lesions. Further improvements are required to enhance accuracy in classifying non-malignant lesions.

Acute and adaptive cardiovascular and metabolic effects of passive heat therapy or high-intensity interval training in patients with severe lower-limb osteoarthritis.

Exercise is painful and difficult to perform for patients with severe lower-limb osteoarthritis; consequently, reduced physical activity contributes to increased cardiometabolic disease risk. The aim of this study was to characterize the acute and adaptive cardiovascular and metabolic effects of two low or no impact therapies in patients with severe lower-limb osteoarthritis: passive heat therapy (Heat) and high-intensity interval training (HIIT) utilizing primarily the unaffected limbs, compared to a control intervention of home-based exercise (Home). Participants completed up to 12 weeks of either Heat (20-30 min immersed in 40°C water followed by ~15-min light resistance exercise), HIIT (6-8 × 60-s intervals on a cross-trainer or arm ergometer at ~90-100% peak V ̇ $$ \dot{V} $$ O2 ) or Home (~15-min light resistance exercise); all 3 sessions/week. Reductions in systolic (12 & 10 mm Hg), diastolic (7 & 4 mm Hg), and mean arterial (8 & 6 mm Hg) blood pressure (BP) were observed following one bout of Heat or HIIT exposure, lasting for the duration of the 20-min monitoring period. Across the interventions (i.e., 12 weeks), resting systolic BP and diastolic BP decreased with Heat (-9 & -4 mm Hg; p < 0.001) and HIIT (-7 & -3 mm Hg; p ≤ 0.011), but not Home (0 & 0 mm Hg; p ≥ 0.785). The systolic and diastolic BP responses to an acute exposure of Heat or HIIT in the first intervention session were moderately correlated with adaptive responses across the intervention (r ≥ 0.54, p ≤ 0.005). Neither intervention improved indices of glycemic control (p = 0.310). In summary, both Heat and HIIT induced potent immediate and adaptive hypotensive effects, and the acute response was moderately predictive of the long-term response.

Attenuation of reverse transcriptase facilitates SAMHD1 restriction of HIV-1 in cycling cells.

BACKGROUND: SAMHD1 is a deoxynucleotide triphosphohydrolase that restricts replication of HIV-1 in differentiated leucocytes. HIV-1 is not restricted in cycling cells and it has been proposed that this is due to phosphorylation of SAMHD1 at T592 in these cells inactivating the enzymatic activity. To distinguish between theories for how SAMHD1 restricts HIV-1 in differentiated but not cycling cells, we analysed the effects of substitutions at T592 on restriction and dNTP levels in both cycling and differentiated cells as well as tetramer stability and enzymatic activity in vitro. RESULTS: We first showed that HIV-1 restriction was not due to SAMHD1 nuclease activity. We then characterised a panel of SAMHD1 T592 mutants and divided them into three classes. We found that a subset of mutants lost their ability to restrict HIV-1 in differentiated cells which generally corresponded with a decrease in triphosphohydrolase activity and/or tetramer stability in vitro. Interestingly, no T592 mutants were able to restrict WT HIV-1 in cycling cells, despite not being regulated by phosphorylation and retaining their ability to hydrolyse dNTPs. Lowering dNTP levels by addition of hydroxyurea did not give rise to restriction. Compellingly however, HIV-1 RT mutants with reduced affinity for dNTPs were significantly restricted by wild-type and T592 mutant SAMHD1 in both cycling U937 cells and Jurkat T-cells. Restriction correlated with reverse transcription levels. CONCLUSIONS: Altogether, we found that the amino acid at residue 592 has a strong effect on tetramer formation and, although this is not a simple "on/off" switch, this does correlate with the ability of SAMHD1 to restrict HIV-1 replication in differentiated cells. However, preventing phosphorylation of SAMHD1 and/or lowering dNTP levels by adding hydroxyurea was not enough to restore restriction in cycling cells. Nonetheless, lowering the affinity of HIV-1 RT for dNTPs, showed that restriction is mediated by dNTP levels and we were able to observe for the first time that SAMHD1 is active and capable of inhibiting HIV-1 replication in cycling cells, if the affinity of RT for dNTPs is reduced. This suggests that the very high affinity of HIV-1 RT for dNTPs prevents HIV-1 restriction by SAMHD1 in cycling cells.

The athlete's vein: venous adaptations in the lower limbs of endurance athletes.

Endurance exercise induces cardiovascular adaptations; the athletic phenotypes of the heart and arteries are well characterized, but few studies have investigated the effects of chronic exercise on the venous system. The aim of this study was to describe the anatomy and function of lower-limb deep and superficial veins in athletes compared with controls. Endurance-trained athletes and untrained controls (13 males, 7 females per group) were examined using ultrasound to measure vein diameter and flow, and air plethysmography to assess calf venous volume dynamics and muscle pump function at rest, during a single step, ambulation (10 steps) and after acute treadmill exercise (30 min ∼80% age-predicted heart rate maximum). Diameters of three of the seven deep veins assessed were larger in athletes (P ≤ 0.0167) and more medial calf perforators were detectable (5 vs. 3, P = 0.0039). Calf venous volume was 22% larger in athletes (P = 0.0057), and calf muscle pump ejection volume and ambulatory venous volume after 10 steps were both greater in athletes (20 and 46% respectively, P ≤ 0.0482). Following acute exercise, flow recovery profiles in deep and superficial veins draining the leg were not different between groups, despite athletes performing approximately four times more work. After exercise, venous volume and ejection volume were reduced by ∼20% in athletes with no change in controls (interaction, P ≤ 0.0372) and although ambulatory venous volume reduced, this remained greater in athletes. These findings highlight venous adaptations that compensate for the demands of regular endurance exercise, all of which are suited to enhance flow through the lower-limb venous system.NEW & NOTEWORTHY Although much literature exists describing adaptations to the heart and arteries in response to endurance exercise training, less is known about the effects on the venous system. Characteristics of "the athlete's vein" described here include deep and perforator vein remodeling, improved drainage, and greater calf venous volume at rest and on calf muscle pump activation. Following exercise, athletes demonstrated prompt flow recovery and appropriate volume reductions, and veins beneficially adapt to better tolerate the demands of regular physical activity.

Mitochondrial DNA haplogroups and trajectories of cardiometabolic risk factors during childhood and adolescence: A prospective cohort study.

BACKGROUND: Mitochondria are organelles responsible for converting glucose into energy. Mitochondrial DNA is exclusively maternally inherited. The role of mitochondrial DNA haplogroups in the aetiology of cardiometabolic disease risk is not well understood. METHODS: Sex-specific associations between common European mitochondrial DNA haplogroups (H, U, J, T, K, V, W, I and X) and trajectories of cardiometabolic risk factors from birth to 18 years were examined in a prospective cohort. Cardiometabolic risk factors measured from birth/mid-childhood to 18 years included body mass index (BMI), fat and lean mass, systolic and diastolic blood pressure, pulse rate, high-density lipoprotein cholesterol (HDL-c), non-HDL-c and triglycerides. Fractional polynomial and linear spline multilevel models explored the sex-specific association between haplogroups and risk factor trajectories. RESULTS: Among a total of 7,954 participants with 79,178 repeated measures per outcome, we found no evidence that haplogroups U, T, J, K and W were associated with cardiometabolic risk factors compared to haplogroup H. In females, haplogroup V was associated with 4.0% (99% CI: -7.5, -0.6) lower BMI at age one but associations did not persist at age 18. Haplogroup X was associated with 1.3kg (99% CI: -2.5, -0.2) lower lean mass at age 9 which persisted at 18. Haplogroup V and X were associated with 9.3% (99% CI: -0.4, 19.0) and 16.4% (99% CI: -0.5,33.3) lower fat mass at age 9, respectively, although confidence intervals spanned the null and associations did not persist at 18. In males, haplogroup I was associated with 2.4% (99% CI: -0.5, 5.3) higher BMI at age 7; widening to 5.1% (99% CI: -0.5, 10.6) at 18 with confidence intervals spanning the null. CONCLUSIONS: Our study demonstrated little evidence of sex-specific associations between mitochondrial DNA haplogroups and cardiometabolic risk factors.

Application of multilevel linear spline models for analysis of growth trajectories in a cohort with repeat antenatal and postnatal measures of growth: a prospective cohort study.

OBJECTIVES: To model trajectories of antenatal and postnatal growth using linear spline multilevel models. DESIGN: Prospective cohort study. SETTING: Maternity hospital in Dublin, Ireland. PARTICIPANTS: 720-759 mother-child pairs from the ROLO study (initially a randomised control trial of a low glycaemic index diet in pregnancy to prevent recurrence of macrosomia [birth weight >4 kg]). PRIMARY OUTCOMES: Trajectories of growth from 20 weeks gestation (abdominal circumference [AC], head circumference [HC] and weight) or birth (length/height) to 5 years. RESULTS: Over 50% of women had third-level education and 90% were of white ethnicity. Women were a mean (SD) age of 32 years (4.2) at recruitment. The best fitting model for AC, HC and weight included a model with 5 linear spline periods. The best fitting models for length/height included a model with 3 linear spline periods from birth to 6 months, 6 months to 2 years and 2 years to 5 years. Comparison of observed and predicted values for each model demonstrated good model fit. For all growth measures, growth rates were generally fastest in pregnancy or immediately post partum (for length/height), with rates of growth slowing after birth and becoming slower still as infancy and childhood progressed. CONCLUSION: We demonstrate the application of multilevel linear spline models for examining growth trajectories when both antenatal and postnatal measures of growth are available. The approach may be useful for cohort studies or randomised control trials with repeat prospective assessments of growth.