The histone methyltransferase SETD2 regulates HIV expression and latency.

Understanding the mechanisms that drive HIV expression and latency is a key goal for achieving an HIV cure. Here we investigate the role of the SETD2 histone methyltransferase, which deposits H3K36 trimethylation (H3K36me3), in HIV infection. We show that prevention of H3K36me3 by a potent and selective inhibitor of SETD2 (EPZ-719) leads to reduced post-integration viral gene expression and accelerated emergence of latently infected cells. CRISPR/Cas9-mediated knockout of SETD2 in primary CD4 T cells confirmed the role of SETD2 in HIV expression. Transcriptomic profiling of EPZ-719-exposed HIV-infected cells identified numerous pathways impacted by EPZ-719. Notably, depletion of H3K36me3 prior to infection did not prevent HIV integration but resulted in a shift of integration sites from highly transcribed genes to quiescent chromatin regions and to polycomb repressed regions. We also observed that SETD2 inhibition did not apparently affect HIV RNA levels, indicating a post-transcriptional mechanism affecting HIV expression. Viral RNA splicing was modestly reduced in the presence of EPZ-719. Intriguingly, EPZ-719 exposure enhanced responsiveness of latent HIV to the HDAC inhibitor vorinostat, suggesting that H3K36me3 can contribute to a repressive chromatin state at the HIV locus. These results identify SETD2 and H3K36me3 as novel regulators of HIV integration, expression and latency.

Vaccine strains of Rift Valley fever virus exhibit attenuation at the maternal-fetal placental interface.

Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and human placenta explant cultures, we sought to identify tissues at the maternal-fetal interface targeted by RVFV. Sheep villi and fetal membranes were highly permissive to RVFV infection resulting in markedly higher virus titers than human cultures. Sheep cultures were most permissive to wild-type RVFV and ΔNSm infection, while live-attenuated RVFV vaccines (LAVs; MP-12, ΔNSs, and ΔNSs/ΔNSm) exhibited reduced replication. The human fetal membrane restricted wild-type and LAV replication, and when infection occurred, it was prominent on the maternal-facing side. Type I and type III interferons were induced in human villi exposed to LAVs lacking the NSs protein. This study supports the use of sheep and human placenta explants to understand vertical transmission of RVFV in mammals and whether LAVs are attenuated at the maternal-fetal interface.IMPORTANCEA direct comparison of replication of Rift Valley fever virus (RVFV) in sheep and human placental explants reveals comparative efficiencies and permissivity to infection and replication. Vaccine strains of RVFV demonstrated reduced infection and replication capacity in the mammalian placenta. This study represents the first direct cross-host comparison of the vertical transmission capacity of this high-priority emerging mosquito-transmitted virus.

Nanoparticle delivery of Tat synergizes with classical latency reversal agents to express HIV antigen targets.

Limited cellular levels of the HIV transcriptional activator Tat are one contributor to proviral latency that might be targeted in HIV cure strategies. We recently demonstrated that lipid nanoparticles containing HIV tat mRNA induce HIV expression in primary CD4 T cells. Here, we sought to further characterize tat mRNA in the context of several benchmark latency reversal agents (LRAs), including inhibitor of apoptosis protein antagonists (IAPi), bromodomain and extra-Terminal motif inhibitors (BETi), and histone deacetylase inhibitors (HDACi). tat mRNA reversed latency across several different cell line models of HIV latency, an effect dependent on the TAR hairpin loop. Synergistic enhancement of tat mRNA activity was observed with IAPi, HDACi, and BETi, albeit to variable degrees. In primary CD4 T cells from durably suppressed people with HIV, tat mRNA profoundly increased the frequencies of elongated, multiply-spliced, and polyadenylated HIV transcripts, while having a lesser impact on TAR transcript frequencies. tat mRNAs alone resulted in variable HIV p24 protein induction across donors. However, tat mRNA in combination with IAPi, BETi, or HDACi markedly enhanced HIV RNA and protein expression without overt cytotoxicity or cellular activation. Notably, combination regimens approached or in some cases exceeded the latency reversal activity of maximal mitogenic T cell stimulation. Higher levels of tat mRNA-driven HIV p24 induction were observed in donors with larger mitogen-inducible HIV reservoirs, and expression increased with prolonged exposure time. Combination LRA strategies employing both small molecule inhibitors and Tat delivered to CD4 T cells are a promising approach to effectively target the HIV reservoir.

Increased Maternal BMI at Time of Delivery Associated with Poor Maternal and Neonatal Outcomes.

OBJECTIVE: Current literature on the risks and outcomes of obesity in pregnancy almost exclusively utilizes prepregnancy body mass index (BMI). Given the rising obesity rate across the United States along with a paucity of available information on the relationship between delivery BMI and maternal and neonatal outcomes, our study aimed to determine the association of maternal BMI at delivery with antepartum, intrapartum, and neonatal complications at an academic referral hospital. STUDY DESIGN: This study is a secondary analysis of data collected for a prospective cohort study of Coronavirus Disease-2019 (COVID-19) in pregnancy. This analysis included all patients who delivered term singleton infants between May 1, 2020, and April 30, 2021, at the University of Iowa Hospitals and Clinics. Demographic and clinical data were obtained from the electronic medical record. The relationship between maternal BMI and maternal and neonatal characteristics of interest was assessed using logistic regression models. A statistical significance threshold of 0.05 was used for all comparisons. RESULTS: There were 1,996 women who delivered term singleton infants during the study period. The median BMI at delivery was 31.7 kg/m2 (interquartile range 27.9, 37.2), with 61.1% of women having a BMI ≥ 30.0 kg/m2. Increasing BMI was significantly associated with nonreassuring fetal status, unscheduled cesarean birth, overall cesarean birth rate, postpartum hemorrhage, prolonged postpartum stay, hypertensive diseases of pregnancy, neonatal hypoglycemia, neonatal intensive care unit admission, decreased APGAR score at 1 minute, and increasing neonatal birth weight. Even when controlling for preexisting hypertension in a multivariate model, increasing BMI was associated with gestational hypertension and preeclampsia. CONCLUSION: Increased maternal BMI at delivery was associated with adverse perinatal outcomes. These findings have implications for clinical counseling regarding risks of pregnancy and delivery for overweight and obese patients and may help inform future studies to improve safety, especially by examining reasons for high cesarean rates. KEY POINTS: · Sixty-one percent of delivering patients had a BMI330 kg/m2 at delivery.. · There was a higher cesarean rate with increasing delivery BMI.. · For every 5-unit increase in maternal BMI, neonatal weight increased by 0.47 g..

Perceptions of disposal options for unused opioid analgesics among people who have been prescribed an opioid analgesic in North Carolina.

Background: Medication disposal programs have been promoted as one solution to the opioid crisis, but uptake by community members has been minimal.Objectives: To clarify perceptions of medication disposal options among people who have been prescribed an opioid analgesic in North Carolina to inform interventions that can facilitate the disposal of unused opioids.Methods: In 2022, we conducted focus groups with participants who received an opioid medication in the past year to gain information to develop an intervention related to the disposal of unused opioid medication (12 focus group discussions (FGDs); total N = 37; 30 identified as female, 6 as male, and 1 as another gender). Participants were shown a slide with the Food and Drug Administration's recommended disposal options and asked about their perceptions of each option. Themes were derived using an inductive, thematic, qualitative approach.Results: Seven themes about perceptions of medication disposal programs emerged from the data. Four of the themes reflect potential barriers to medication disposal: failed disposal attempts, lack of sufficient education on proper disposal, unclear meaning of specific disposal language, and concerns about existing disposal options. Three of the themes provide insight on potential facilitators of medication disposal: preference of low-cost disposal options, ease and accessibility among disposal methods, and preferred disposal methods.Conclusion: Patients should be provided clear and consistent guidance from prescribers and dispensing pharmacists on when and how to dispose of unused medications and opportunities to dispose of medications at no cost to the patient.

Similar muscle hypertrophy following eight weeks of resistance training to momentary muscular failure or with repetitions-in-reserve in resistance-trained individuals.

This study examined the influence of resistance training (RT) proximity-to-failure, determined by repetitions-in-reserve (RIR), on quadriceps hypertrophy and neuromuscular fatigue. Resistance-trained males (n = 12) and females (n = 6) completed an 8-week intervention involving two RT sessions per week. Lower limbs were randomised to perform the leg press and leg extension exercises either to i) momentary muscular failure (FAIL), or ii) a perceived 2-RIR and 1-RIR, respectively (RIR). Muscle thickness of the quadriceps [rectus femoris (RF) and vastus lateralis (VL)] and acute neuromuscular fatigue (i.e., repetition and lifting velocity loss) were assessed. Data was analysed with Bayesian linear mixed-effect models. Increases in quadriceps thickness (average of RF and VL) from pre- to post-intervention were similar for FAIL [0.181 cm (HDI: 0.119 to 0.243)] and RIR [0.182 cm (HDI: 0.115 to 0.247)]. Between-protocol differences in RF thickness slightly favoured RIR [-0.036 cm (HDI: -0.113 to 0.047)], but VL thickness slightly favoured FAIL [0.033 cm (HDI: -0.046 to 0.116)]. Mean volume was similar across the RT intervention between FAIL and RIR. Lifting velocity and repetition loss were consistently greater for FAIL versus RIR, with the magnitude of difference influenced by the exercise and the stage of the RT intervention.

Terminating RT sets with a close proximity-to-failure (e.g., 1- to 2-RIR) can be sufficient to promote similar hypertrophy of the quadriceps as reaching momentary muscular failure in resistance-trained individuals over eight weeks, but the overall influence of proximity-to-failure on muscle-specific hypertrophy may also depend on other factors (e.g., exercise selection, order, and subsequent musculature targeted).Due to high repetition loss (from the first to final set) when sets are terminated at momentary muscular failure, performing RT with 1- to 2-RIR allows for similar volume load and repetition volume accumulation as reaching momentary muscular failure across eight weeks, possibly influencing the overall RT stimulus achieved.Performing RT to momentary muscular failure consistently induces higher levels of acute neuromuscular fatigue versus RT performed with 1- to 2-RIR; however, improved fatigue resistance overtime may attenuate acute neuromuscular fatigue and subsequent repetition loss (but may depend on the exercise performed).

Total Joint Arthroplasty Outcomes in Eligible Patients Versus Patients Who Failed to Meet at Least 1 Eligibility Criterion: A Single-Center Retrospective Analysis.

BACKGROUND: This study looks to investigate how not meeting eligibility criteria affects postoperative outcomes following total joint arthroplasty surgery. METHODS: A retrospective review was conducted of total joint arthroplasty patients at a single academic institution. Demographics, laboratory values, and complications were recorded. Continuous and categorical variables were compared using the Student's T-test and the Chi-Square test, respectively. Multivariable analysis was used to control for confounding variables. RESULTS: Our study included 915 total hip and 1,579 total knee arthroplasty patients. For total hip and total knee arthroplasty, there were no significant differences in complications (P = .11 and .87), readmissions (P = .83 and .2), or revision surgeries (P = .3 and 1) when comparing those who met all criteria to those who did not. Total hip arthroplasty patients who did not meet two criteria had 16.1 higher odds (P = .02) of suffering a complication. There were no differences in complications (P = .34 and .41), readmissions (P = 1 and .55), or revision surgeries (P = 1 and .36) between ineligible patients treated by total joint arthroplasty surgeons and those who were not. Multivariable analysis demonstrated no eligibility factors were associated with outcomes for both total hip and knee arthroplasty. CONCLUSIONS: There was no significant difference in outcomes between those who met all eligibility criteria and those who did not. Not meeting two criteria conferred significantly higher odds of suffering a complication for total hip arthroplasty patients. Total joint arthroplasty surgeons had similar outcomes to non-total joint surgeons, although their patient population was more complex. LEVEL OF EVIDENCE: III.

Thiophene Stability in Photodynamic Therapy: A Mathematical Model Approach.

Thiophene-containing photosensitizers are gaining recognition for their role in photodynamic therapy (PDT). However, the inherent reactivity of the thiophene moiety toward singlet oxygen threatens the stability and efficiency of these photosensitizers. This study presents a novel mathematical model capable of predicting the reactivity of thiophene toward singlet oxygen in PDT, using Conceptual Density Functional Theory (CDFT) and genetic programming. The research combines advanced computational methods, including various DFT techniques and symbolic regression, and is validated with experimental data. The findings underscore the capacity of the model to classify photosensitizers based on their photodynamic efficiency and safety, particularly noting that photosensitizers with a constant rate 1000 times lower than that of unmodified thiophene retain their photodynamic performance without substantial singlet oxygen quenching. Additionally, the research offers insights into the impact of electronic effects on thiophene reactivity. Finally, this study significantly advances thiophene-based photosensitizer design, paving the way for therapeutic agents that achieve a desirable balance between efficiency and safety in PDT.

Accuracy of Intraset Repetitions-in-Reserve Predictions During the Bench Press Exercise in Resistance-Trained Male and Female Subjects.

ABSTRACT: Refalo, MC, Remmert, JF, Pelland, JC, Robinson, ZP, Zourdos, MC, Hamilton, DL, Fyfe, JJ, and Helms, ER. Accuracy of intraset repetitions-in-reserve predictions during the bench press exercise in resistance-trained male and female subjects. J Strength Cond Res 38(3): e78-e85, 2024-This study assessed the accuracy of intraset repetitions-in-reserve (RIR) predictions to provide evidence for the efficacy of RIR prescription as a set termination method to inform proximity to failure during resistance training (RT). Twenty-four resistance trained male ( n = 12) and female ( n = 12) subjects completed 2 experimental sessions involving 2 sets performed to momentary muscular failure (barbell bench press exercise) with 75% of 1 repetition maximum (1RM), whereby subjects verbally indicated when they perceived to had reached either 1 RIR or 3 RIR. The difference between the predicted RIR and the actual RIR was defined as the "RIR accuracy" and was quantified as both raw (i.e., direction of error) and absolute (i.e., magnitude of error) values. High raw and absolute mean RIR accuracy (-0.17 ± 1.00 and 0.65 ± 0.78 repetitions, respectively) for 1-RIR and 3-RIR predictions were observed (including all sets and sessions completed). We identified statistical equivalence (equivalence range of ±1 repetition, thus no level of statistical significance was set) in raw and absolute RIR accuracy between (a) 1-RIR and 3-RIR predictions, (b) set 1 and set 2, and (c) session 1 and session 2. No evidence of a relationship was found between RIR accuracy and biological sex, years of RT experience, or relative bench press strength. Overall, resistance-trained individuals are capable of high absolute RIR accuracy when predicting 1 and 3 RIR on the barbell bench press exercise, with a minor tendency for underprediction. Thus, RIR prescriptions may be used in research and practice to inform the proximity to failure achieved upon set termination.

Analysis of the Behavior of Deep Eutectic Solvents upon Addition of Water: Its Effects over a Catalytic Reaction.

This study presents the potential role of deep eutectic solvents (DESs) in a lipase-catalyzed hydrolysis reaction as a co-solvent in an aqueous solution given by a phosphate buffer. Ammonium salts, such as choline chloride, were paired with hydrogen bond donors, such as urea, 1,2,3-propanetriol, and 1,2 propanediol. The hydrolysis of p-nitrophenyl laureate was carried out with the lipase Candida antarctica Lipase B (CALB) as a reaction model to evaluate the solvent effect and tested in different DES/buffer phosphate mixtures at different % w/w. The results showed that two mixtures of different DES at 25 % w/w were the most promising solvents, as this percentage enhanced the activities of CALB, as evidenced by its higher catalytic efficiency (kcatKM). The solvent analysis shows that the enzymatic reaction requires a reaction media rich in water molecules to enable hydrogen-bond formation from the reaction media toward the enzymatic reaction, suggesting a better interaction between the substrate and the enzyme-active site. This interaction could be attributed to high degrees of freedom influencing the enzyme conformation given by the reaction media, suggesting that CALB acquires a more restrictive structure in the presence of DES or the stabilized network given by the hydrogen bond from water molecules in the mixture improves the enzymatic activity, conferring conformational stability by solvent effects. This study offers a promising approach for applications and further perspectives on genuinely green industrial solvents.

The surgical learning curve for percutaneous Zadek osteotomy for treatment of insertional achilles tendinopathy.

INTRODUCTION: The Zadek Osteotomy has been described as an effective technique for the treatment of insertional Achilles tendinopathy. Recently, this strategy has been modified using minimally invasive techniques. A learning curve has been observed in many minimally invasive procedures in foot and ankle surgery. This retrospective study first intended to evaluate if there is a learning curve associated with the percutaneous Zadek Osteotomy. Further, if a learning curve was observed, we planned to assess the data for associated changes in complications and postoperative outcomes. METHODS: A retrospective analysis of 98 patients who underwent percutaneous Zadek Osteotomy was performed. Patient charts were reviewed for operative times, complications, union rates, and Foot Function Index (FFI) and Visual Analogue Scale (VAS) scores. Analysis of variance was utilized to assess for differences between groups of cases. RESULTS: Patients included 61 females and 37 males. Mean age was 51.28 ± 11.12 (range 28-81) years. Mean follow-up time was 42.07 ± 12.99 (range 24-65) months. Significant increases in operative times were observed in cases 1-14 when compared to cases 15-98 (p < 0.001). Improvements in FFI and VAS scores were observed at final follow-up within each case group (p < 0.001); there were no differences detected in FFI or VAS scores between groups of cases. There was no difference detected in number of complications between intervals of cases. CONCLUSION: A learning curve was observed for the percutaneous Zadek Osteotomy, which was overcome around case 14. This learning curve was only observed in terms of procedure length. A surgeon's level of inexperience with the technique does not appear to affect functional outcomes, nonunion, or need for revision. LEVEL OF EVIDENCE IV: Data will not be deposited in a repository.

Open Ankle Fractures in Older Individuals: A Multi-center Study.

The purpose of this study is to identify demographics, etiology, comorbidities, treatment, complications, and outcomes for older patients with open ankle fractures. Patients ≥60 years old who sustained an open ankle fracture between January 1, 2004 and March 31, 2014 at 6 Level 1 trauma centers were retrospectively reviewed. Univariate analysis using chi-squared or Student's t test was performed to identify associations between preoperative variables and 2 postoperative outcomes of interest: amputation and 1-year mortality. Multivariate analysis was performed using stepwise logistical regression to identify independent predictors of postoperative amputation and 1-year mortality. Of the 162 total patients, the most common mechanism of injury was a ground-level fall (51.9%). The most common fracture types were bimalleolar fractures (52.5%) followed by trimalleolar fractures (26.5%), with 41.5% of the fractures classified as Gustilo Anderson Classification Type 2 and 38.6% classified as Type 3A. The average number of surgeries required per patient was 2.1. Complications included: 15.4% superficial infection rate, 9.9% deep infection rate, and 9.3% amputation rate. The 1-year mortality rate was 13.6% and the overall mortality rate was 25.9%. Male gender and fracture type were found to be independent predictors for amputation after surgery (p = .009, .005, respectively). Older age and having diabetes were independent predictors for 1-year mortality after surgery (p = .021, .005 respectively). Overall, open ankle fractures in older individuals were associated with high rates of amputation and mortality.

Minimally invasive Dorsal cheilectomy and Hallux metatarsophalangeal joint arthroscopy for the treatment of Hallux Rigidus.

BACKGROUND: Minimally invasive dorsal cheilectomy (MIDC) has become a popular alternative to an open approach for treating Hallux Rigidus (HR). To reduce some of the complications related to the MIDC approach, a first metatarsophalangeal (MTP) joint arthroscopy can be performed in addition to address the intra-articular pathology associated with Hallux Rigidus. This study aims to examine the effectiveness of MIDC with first MTP arthroscopy in patients with HR with a minimum 1-year follow-up. METHODS: This was a multicenter retrospective review for adult patients with Coughlin and Shurnass Grade 0-3 who were treated with MIDC and first MTP arthroscopy between 3/1/2020 and 8/1/2022, with at least one year of follow-up data. Demographic information, first MTP range of motion (ROM), visual analog scale (VAS), Manchester-Oxford Foot Questionnaire (MOXFQ), and EQ-5D-5 L scores were collected. Continuous data was expressed as a mean and standard deviation, categorical data was expressed as a percentage. Wilcoxon Rank Sum test was used to compare continuous variables. All P < 0.05 was considered significant. RESULTS: A total of 31 patients were included in the study. Average follow-up time was 16.5 months (range: 12 to 26.2). There was 1 (3.2%) undersurface EHL tendon tear, 2 (6.5%) conversions to an MTP fusion, and 1 (3.2%) revision cheilectomy and capsular release for MTP joint contracture. There was a significant improvement in patient's ROM in dorsiflexion (50 vs 89.6 degrees, P = 0.002), postoperative VAS pain scores (6.4 vs 2.1, P < 0.001), MOXFQ pain scores (58.1 vs 30.7, P = 0.001), MOXFQ Walking/Standing scores (56.6 vs 20.6, P = 0.001), MOXFQ Social Interaction scores (47.3 vs 19.36, P = 0.002), and MOXFQ Index scores (54.7 vs 22.4, P < 0.001). CONCLUSION: We found that MIDC with first MTP arthroscopy was effective at improving patient-reported outcomes at one year with low complication and revision rates. These results suggest that MIDC with first MTP arthroscopy is an effective treatment for early-stage HR. LEVEL OF EVIDENCE: IV.

Perceptual Weighting of V1 Spikes Revealed by Optogenetic White Noise Stimulation.

During visually guided behaviors, mere hundreds of milliseconds can elapse between a sensory input and its associated behavioral response. How spikes occurring at different times are integrated to drive perception and action remains poorly understood. We delivered random trains of optogenetic stimulation (white noise) to excite inhibitory interneurons in V1 of mice of both sexes while they performed a visual detection task. We then performed a reverse correlation analysis on the optogenetic stimuli to generate a neuronal-behavioral kernel, an unbiased, temporally precise estimate of how suppression of V1 spiking at different moments around the onset of a visual stimulus affects detection of that stimulus. Electrophysiological recordings enabled us to capture the effects of optogenetic stimuli on V1 responsivity and revealed that the earliest stimulus-evoked spikes are preferentially weighted for guiding behavior. These data demonstrate that white noise optogenetic stimulation is a powerful tool for understanding how patterns of spiking in neuronal populations are decoded in generating perception and action.SIGNIFICANCE STATEMENT During visually guided actions, continuous chains of neurons connect our retinas to our motoneurons. To unravel circuit contributions to behavior, it is crucial to establish the relative functional position(s) that different neural structures occupy in processing and relaying the signals that support rapid, precise responses. To address this question, we randomly inhibited activity in mouse V1 throughout the stimulus-response cycle while the animals did many repetitions of a visual task. The period that led to impaired performance corresponded to the earliest stimulus-driven response in V1, with no effect of inhibition immediately before or during late stages of the stimulus-driven response. This approach offers experimenters a powerful method for uncovering the temporal weighting of spikes from stimulus to response.

Impact of Rapid Molecular Multiplex Gastrointestinal Pathogen Testing in Management of Children during a Shigella Outbreak.

Fecal culture for isolation and identification of Shigella may take days. The BioFire FilmArray Gastrointestinal (GI) panel (bioMérieux, France) is a PCR-based assay that detects enteric pathogens including Shigella/enteroinvasive Escherichia coli (EIEC) in about an hour. The aim of this study was to evaluate the impact of GI panel detection of Shigella in a pediatric emergency department (ED) during an outbreak. Stool samples from children with acute gastroenteritis were tested by the GI panel. Test results were either withheld in preintervention (PRE) or reported to clinicians/families in the postintervention (POST) period. The impact of the GI panel testing on patient management and outcomes was measured. Shigella/EIEC was identified by the GI panel in the PRE (n = 30) and POST (n = 21) phase. The GI panel detected more Shigella infections than did culture; six of 31 (19.4%) Shigella GI panel-positive patients who also had stool cultures were missed by culture. Azithromycin therapy was prescribed for 20% of subjects in the PRE phase and 71.4% of subjects in the POST phase (P < 0.001). Time from the clinical encounter until starting azithromycin therapy was shorter in the POST phase (n = 9), 8.25 h (range, 6.37 to 52.37 h), than in the PRE phase (n = 1), 72 h. Six subjects in the PRE phase visited additional providers compared with one in the POST phase. Prompt diagnosis of shigellosis with the GI panel may provide the opportunity for prompt antimicrobial therapy and avoid additional visits to providers due to early definitive diagnosis. Prompt diagnosis of Shigella at an ED visit may optimize patient management and reduce transmission.

Epigenomic characterization of latent HIV infection identifies latency regulating transcription factors.

Transcriptional silencing of HIV in CD4 T cells generates a reservoir of latently infected cells that can reseed infection after interruption of therapy. As such, these cells represent the principal barrier to curing HIV infection, but little is known about their characteristics. To further our understanding of the molecular mechanisms of latency, we characterized a primary cell model of HIV latency in which infected cells adopt heterogeneous transcriptional fates. In this model, we observed that latency is a stable, heritable state that is transmitted through cell division. Using Assay of Transposon-Accessible Chromatin sequencing (ATACseq) we found that latently infected cells exhibit greatly reduced proviral accessibility, indicating the presence of chromatin-based structural barriers to viral gene expression. By quantifying the activity of host cell transcription factors, we observe elevated activity of Forkhead and Kruppel-like factor transcription factors (TFs), and reduced activity of AP-1, RUNX and GATA TFs in latently infected cells. Interestingly, latency reversing agents with different mechanisms of action caused distinct patterns of chromatin reopening across the provirus. We observe that binding sites for the chromatin insulator CTCF are highly enriched in the differentially open chromatin of infected CD4 T cells. Furthermore, depletion of CTCF inhibited HIV latency, identifying this factor as playing a key role in the initiation or enforcement of latency. These data indicate that HIV latency develops preferentially in cells with a distinct pattern of TF activity that promotes a closed proviral structure and inhibits viral gene expression. Furthermore, these findings identify CTCF as a novel regulator of HIV latency.

Long-term outcomes of patients with ventricular arrhythmias and negative programmed ventricular stimulation followed with implantable loop recorders: Impact of delayed-enhancement cardiac magnetic resonance imaging.

BACKGROUND: Programed ventricular stimulation (PVS) is a risk stratification tool in patients at risk for adverse arrhythmia outcomes. Patients with negative PVS may yet be at risk for adverse arrhythmia-related events, particularly in the presence of symptomatic ventricular arrhythmias (VA). OBJECTIVE: To investigate the long-term outcomes of real-world patients with symptomatic VA without indication for device therapy and negative PVS, and to examine the role of cardiac scaring on arrhythmia recurrence. METHODS: Patients with symptomatic VA, and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), and negative PVS testing were included. All patients underwent placement of implantable cardiac monitors (ICM). Survival analysis was performed to investigate the impact of LGE-CMR findings on survival free from adverse arrhythmic events. RESULTS: Seventy-eight patients were included (age 60 ± 14 years, women n = 36 (46%), ejection fraction 57 ± 9%, cardiomyopathy n = 26 (33%), mitral valve prolapse [MVP] n = 9 (12%), positive LGE-CMR scar n = 49 (62%), history of syncope n = 23 (29%)) including patients with primarily premature ventricular contractions (n = 21) or nonsustained VA (n = 57). Patients were followed for 1.6 ± 1.5 years during which 14 patients (18%) experienced VA requiring treatment (n = 14) or syncope due to bradycardia (n = 2). Four/9 patients (44%) with MVP experienced VA (n = 3) or syncope (n = 1). Baseline characteristics between those with and without adverse events were similar (p > 0.05); however, the presence of cardiac scar on LGE-CMR was independently associated with an increased risk of adverse events (hazard ratio: 5.6 95% confidence interval: [1.2-27], p = 0.03, log-rank p = 0.03). CONCLUSIONS: In a real-world cohort with long-term follow-up, adverse arrhythmic outcomes occurred in 18% of patients with symptomatic VA despite negative PVS, and this risk was significantly greater in patients with positive DE-CMR scar. Long term-monitoring, including the use of ICM, may be appropriate in these patients.

Incidental left atrial appendage isolation after catheter ablation of persistent atrial fibrillation: Mechanisms and long-term risk of thromboembolism.

INTRODUCTION: Incidental left atrial appendage (LAA) isolation may occur during radiofrequency ablation of persistent atrial fibrillation (AF). The study aims to describe the mechanisms and long-term thromboembolic risk related to incidental LAA isolation. METHODS: Patients who experienced incidental LAA isolation after AF ablation were included. Culprit sites where ablation resulted in LAA isolation were identified. Thromboembolic risk despite oral anticoagulation (OAC) was compared to that in a propensity-matched control group without LAA isolation. RESULTS: Forty-one patients with LAA isolation, and 82 matched patients without LAA isolation were included. The patient age, ejection fraction, LA diameter, and CHA2 DS2 -VASc score were 64 ± 11 years, 55 ± 12%, 45.0 ± 7 mm and 2.62 ± 1.5, respectively. Culprit sites included the LAA base, mitral isthmus, inferior LA, Bachmann's bundle, coronary sinus, and Marshall vein. After 4.2 ± 3.6 years follow-up, thromboembolism occurred in 7 of 41 patients (17%) with LAA isolation versus 3 of 82 patients (4%) without isolation (log rank p < .009, HR 5.14, 95% CI [1.32-19.94], p = .02). Patients with and without thromboembolism had similar CHA2 DS2 -VASc scores (2.65 ± 1.3 vs. 2.71 ± 0.76, p = .89). Thromboembolism occurred during noncompliance with or temporary discontinuation of OAC in four of the seven patients. CONCLUSIONS: Incidental LAA isolation may occur during ablation of atrial arrhythmias in the vicinity of, or even at sites remote from the appendage. Patients with incidental LAA isolation had higher rates of thromboembolism compared to patients without isolation. Since thromboembolism may occur despite prescription for OAC, the risks of LAA isolation must be weighed against clinical benefit and appendage occlusion devices should be considered in vulnerable patients.

Anatomical location of leadless pacemaker and the risk of pacing-induced cardiomyopathy.

BACKGROUND: It is unclear if the location of implantation of the leadless pacemaker (LP) makes a difference in the incidence of pacing-induced cardiomyopathy (PICM). AIM: The aim of this study was to compare the incidence of PICM based on the location of implantation of LP. METHODS: A total of 358 consecutive patients [women: 171 (48%), mean age: 73 ± 15 years] with left ventricular ejection fraction (EF) > 50%, who received an LP (Micra) between January 2017 and June 2022, formed the study cohort. Micra-AV and Micra-VR were implanted in 122 (34%) and 236 (66%) patients, respectively. Fluoroscopically, the location of implantation of LP in the interventricular septum (IS) was divided into two equal halves (apex/apical septum [AS] and mid/high septum [HS]). During follow-up, PICM was defined as an EF drop of ≥10%. RESULTS: LP was implanted in 109 (34%) and 249 (66%) patients at AS and HS locations, respectively. During a mean 18 ± 8 months follow-up, 28 patients (7.8%) developed PICM. Among the 249 patients with HS placement of LP, 10 (4%) developed PICM, whereas among the 109 patients with AS placement of LP, 18 (16.5%) developed PICM (p = .002). AS location was associated with a higher risk of PICM compared to HS locations (adjusted hazard ratio: 4.42, p < .001). CONCLUSION: AS location of LP was associated with a higher risk of PICM compared to HS placement. Larger randomized studies are needed to confirm our findings.

Impact of osteoarthritis disease severity on treatment patterns and healthcare resource use: analysis of real-world data.

OBJECTIVE: To understand treatment patterns and healthcare resource utilization (HCRU) related to osteoarthritis (OA) disease severity in patients in five European countries. METHOD: Data were drawn from the Adelphi OA Disease Specific Programme™ (2017-18). Physicians classified their patients as having mild, moderate, or severe OA, and provided details on their current prescribed therapy and HCRU, including healthcare professional (HCP) consultations, diagnostics and testing, and hospitalizations. Comparisons between disease severity groups were made using analysis of variance and chi-squared tests. RESULTS: The study included 489 physicians (primary care physicians, rheumatologists, orthopaedic surgeons) reporting on 3596 OA patients: 24% mild, 53% moderate, and 23% severe disease. Both physicians and patients reported decreasing satisfaction with treatment with greater disease severity, despite the number of classes of prescribed drugs and increased use of opioids, which were used in almost half of patients with severe OA. For patients whose treatment was not effective, physicians prescribed the same therapeutic options, which were cycled in subsequent treatment lines, with multiple treatment regimens being commonly used. Patients with greater symptom severity also had more physician consultations, while the numbers of tests/imaging, predominantly X-rays, conducted to diagnose or monitor OA increased significantly with disease severity. The type of HCP involvement in patient management also varied by OA severity. CONCLUSIONS: Across five European countries, the use of both non-pharmacological and pharmacological treatments increases with greater disease severity. Those with more severe disease place a greater demand on healthcare resources, with HCP consultations, tests, and hospital visits increasing with severity.