Perinatal outcomes following abdominoplasty: a retrospective study and review of current literature.

BACKGROUND: Abdominoplasty surgery is a common body contouring surgery to remove excess fat and skin and restore weakened or separated abdominal muscles caused by aging, pregnancy, or weight fluctuations. There is limited literature regarding patient and pregnancy outcomes after abdominoplasty. OBJECTIVE: This study aimed to determine whether there was a correlation between adverse pregnancy outcomes and history of abdominoplasty. STUDY DESIGN: Our study used a large federated deidentified national health research network with data sourced from 68 healthcare organizations within the United States (TriNetX; data accessed on August 19, 2022). All patients with a record of pregnancy were identified using the International Classification of Diseases, Ninth Revision and Tenth Revision, codes and were grouped into those with a history of abdominoplasty and those without. This study evaluated the perinatal outcomes of fetal growth restriction, abnormal umbilical artery Dopplers, gestational hypertension, preeclampsia, preterm delivery, preterm premature rupture of membranes, gestational diabetes mellitus, macrosomia, stillbirth, abnormal placentation, and wound disruption or infection occurring during a patient's pregnancy after abdominoplasty. Propensity matching was performed to account for potential confounders. An alpha level of <.05 was considered statistically significant. RESULTS: Of the 44,737 patients meeting our criteria, 304 had a history of abdominoplasty, whereas 44,433 did not (control). Our study found that patients with a history of abdominoplasty had significantly higher gravidity, were largely located in the Southern and Midwest region, and had higher counts of vaginal deliveries and cesarean deliveries than the control cohort (Table 1). After propensity score matching, our study found a lower risk of preeclampsia and preterm premature rupture of membranes in patients with abdominoplasty (odds ratio, 0.46; 95% confidence interval, 0.32-0.67; P<.0001) (Table 2). Furthermore, abdominoplasty was associated with an increased risk of preterm delivery (odds ratio, 2.15; 95% confidence interval, 1.48-3.13; P=.0002) (Table 2). Lastly, this study did not find significant differences in the other perinatal outcomes (Table 2). CONCLUSION: Our data suggest that abdominoplasty may be associated with a relative increase in the rates of preterm delivery and cesarean delivery and that other perinatal outcomes are not increased. This provides evidence that future desire for pregnancy need not be a relative contraindication to abdominoplasty.

Association between chiropractic spinal manipulation and cauda equina syndrome in adults with low back pain: Retrospective cohort study of US academic health centers.

BACKGROUND: Cauda equina syndrome (CES) is a lumbosacral surgical emergency that has been associated with chiropractic spinal manipulation (CSM) in case reports. However, identifying if there is a potential causal effect is complicated by the heightened incidence of CES among those with low back pain (LBP). The study hypothesis was that there would be no increase in the risk of CES in adults with LBP following CSM compared to a propensity-matched cohort following physical therapy (PT) evaluation without spinal manipulation over a three-month follow-up period. METHODS: A query of a United States network (TriNetX, Inc.) was conducted, searching health records of more than 107 million patients attending academic health centers, yielding data ranging from 20 years prior to the search date (July 30, 2023). Patients aged 18 or older with LBP were included, excluding those with pre-existing CES, incontinence, or serious pathology that may cause CES. Patients were divided into two cohorts: (1) LBP patients receiving CSM or (2) LBP patients receiving PT evaluation without spinal manipulation. Propensity score matching controlled for confounding variables associated with CES. RESULTS: 67,220 patients per cohort (mean age 51 years) remained after propensity matching. CES incidence was 0.07% (95% confidence intervals [CI]: 0.05-0.09%) in the CSM cohort compared to 0.11% (95% CI: 0.09-0.14%) in the PT evaluation cohort, yielding a risk ratio and 95% CI of 0.60 (0.42-0.86; p = .0052). Both cohorts showed a higher rate of CES during the first two weeks of follow-up. CONCLUSIONS: These findings suggest that CSM is not a risk factor for CES. Considering prior epidemiologic evidence, patients with LBP may have an elevated risk of CES independent of treatment. These findings warrant further corroboration. In the meantime, clinicians should be vigilant to identify LBP patients with CES and promptly refer them for surgical evaluation.

Prevalence and Predictors of Barrett's Esophagus After Negative Initial Endoscopy: Analysis From Two National Databases.

BACKGROUND & AIMS: Guidelines suggest a single screening esophagogastroduodenoscopy (EGD) in patients with multiple risk factors for Barrett's esophagus (BE). We aimed to determine BE prevalence and predictors on repeat EGD after a negative initial EGD, using 2 large national databases (GI Quality Improvement Consortium [GIQuIC] and TriNetX). METHODS: Patients who underwent at least 2 EGDs were included and those with BE or esophageal adenocarcinoma detected at initial EGD were excluded. Patient demographics and prevalence of BE on repeat EGD were collected. Multivariate logistic regression was performed to assess for independent risk factors for BE detected on the repeat EGD. RESULTS: In 214,318 and 153,445 patients undergoing at least 2 EGDs over a median follow-up of 28-35 months, the prevalence of BE on repeat EGD was 1.7% in GIQuIC and 3.4% in TriNetX, respectively (26%-45% of baseline BE prevalence). Most (89%) patients had nondysplastic BE. The prevalence of BE remained stable over time (from 1 to >5 years from negative initial EGD) but increased with increasing number of risk factors. BE prevalence in a high-risk population (gastroesophageal reflux disease plus ≥1 risk factor for BE) was 3%-4%. CONCLUSIONS: In this study of >350,000 patients, rates of BE on repeat EGD ranged from 1.7%-3.4%, and were higher in those with multiple risk factors. Most were likely missed at initial evaluation, underscoring the importance of a high-quality initial endoscopic examination. Although routine repeat endoscopic BE screening after a negative initial examination is not recommended, repeat screening may be considered in carefully selected patients with gastroesophageal reflux disease and ≥2 risk factors for BE, potentially using nonendoscopic tools.

Bell's Palsy and COVID-19: Insights from a Population-Based Analysis.

Background: Coronavirus disease 2019 (COVID-19) has been linked to Bell's palsy and facial paralysis. Studies have also shown increased risk of Bell's palsy in unvaccinated COVID-19 patients. Objective: To compare the relationship between Bell's palsy and COVID-19 infection and vaccination. Design: This is a retrospective longitudinal study. Methods: The COVID-19 research network was used to identify patients with facial palsy presenting to 70 health care organizations in the United States. The incidence of Bell's palsy was measured within an 8-week window after COVID-19 test or vaccination event in identified patients. Results: Incidence of facial palsy diagnosis (0.99%) was higher than the background rate within 2 months of COVID-19 infection. When compared with their negative counterparts, patients with COVID-19 infection had significantly higher risk of Bell's palsy (risk ratio [RR] = 1.77, p < 0.01) and facial weakness (RR = 2.28, p < 0.01). Risk ratio was also amplified when evaluating Bell's palsy (RR = 12.57, p < 0.01) and facial palsy (RR = 44.43; p < 0.01) in COVID-19-infected patients against patients who received COVID-19 vaccination. Conclusion: In our patient population, there is a higher risk of developing facial palsy within 2 months of COVID-19 infection versus vaccination. Vaccinated patients are not at higher risk of developing facial palsy.

A multifunctional Wnt regulator underlies the evolution of rodent stripe patterns.

Animal pigment patterns are excellent models to elucidate mechanisms of biological organization. Although theoretical simulations, such as Turing reaction-diffusion systems, recapitulate many animal patterns, they are insufficient to account for those showing a high degree of spatial organization and reproducibility. Here, we study the coat of the African striped mouse (Rhabdomys pumilio) to uncover how periodic stripes form. Combining transcriptomics, mathematical modelling and mouse transgenics, we show that the Wnt modulator Sfrp2 regulates the distribution of hair follicles and establishes an embryonic prepattern that foreshadows pigment stripes. Moreover, by developing in vivo gene editing in striped mice, we find that Sfrp2 knockout is sufficient to alter the stripe pattern. Strikingly, mutants exhibited changes in pigmentation, revealing that Sfrp2 also regulates hair colour. Lastly, through evolutionary analyses, we find that striped mice have evolved lineage-specific changes in regulatory elements surrounding Sfrp2, many of which may be implicated in modulating the expression of this gene. Altogether, our results show that a single factor controls coat pattern formation by acting both as an orienting signalling mechanism and a modulator of pigmentation. More broadly, our work provides insights into how spatial patterns are established in developing embryos and the mechanisms by which phenotypic novelty originates.

Pregnancy and spontaneous cervical artery dissection: A propensity-matched retrospective cohort study.

OBJECTIVES: We hypothesized that pregnant women would have an increased risk of spontaneous cervical artery dissection (sCeAD) affecting the carotid or vertebral arteries over one-year follow-up after the first trimester ultrasound compared to matched non-pregnant controls. MATERIALS AND METHODS: We queried a United States research network (TriNetX, Inc.) of de-identified medical records of >111 million patients, with data spanning 2008-2023. We included women aged ≥18 and excluded those with trauma and conditions potentially causative of sCeAD. Women were divided into cohorts based on a1 first trimester ultrasound and subsequent labor, delivery, or full-term pregnancy, or2 gynecological examination and no pregnancy. We used propensity matching to control for variables associated with sCeAD and calculated the risk ratio (RR) of sCeAD occurring over one-year follow-up from the index date of ultrasound or gynecological exam. RESULTS: After matching, the incidence rate of sCeAD in the pregnancy cohort was 8.0 (95% CI: 8.0-8.1) per 100,000 person-years, compared to 3.9 (95% CI: 3.9-3.9) per 100,000 person-years in the non-pregnancy cohort, yielding an RR (95% CI) of 2.06 (1.17-3.61; P= .0104). A cumulative incidence graph suggested that most cases of sCeAD in the pregnancy cohort occurred during pregnancy rather than the postpartum period. CONCLUSIONS: Our findings demonstrate that women have a twofold increased risk of sCeAD during pregnancy and the postpartum period compared to non-pregnant women. Further research is needed to determine whether maternal comorbidities such as preeclampsia account for these findings, and clarify when sCeAD occurs in relation to pregnancy or the postpartum period.

Association between chiropractic spinal manipulation and gabapentin prescription in adults with radicular low back pain: retrospective cohort study using US data.

OBJECTIVES: Radicular low back pain (rLBP) is often treated off-label with gabapentin or by chiropractors using chiropractic spinal manipulative therapy (CSMT). To date, no studies have examined the association between these interventions. We hypothesised that adults under 50 years of age receiving CSMT for newly diagnosed rLBP would have reduced odds of receiving a gabapentin prescription over 1 year-follow-up. DESIGN: Retrospective cohort study. SETTING: US network including linked medical records, medical claims and pharmacy claims of >122 million patients attending large healthcare organisations (TriNetX), queried 15 June 2023, yielding data from 2017 to 2023. PARTICIPANTS: Adults aged 18-49 were included at their first occurrence of rLBP diagnosis. Exclusions were severe pathology, other spinal conditions, on-label gabapentin indications and gabapentin contraindications. Propensity score matching controlled for variables associated with gabapentin use and receipt of prescription medication over the preceding year. INTERVENTIONS: Patients were divided into CSMT or usual medical care cohorts based on the care received on the index date of rLBP diagnosis. PRIMARY AND SECONDARY OUTCOME MEASURES: OR for gabapentin prescription. RESULTS: After propensity matching, there were 1635 patients per cohort (mean age 36.3±8.6 years, 60% women). Gabapentin prescription over 1-year follow-up was significantly lower in the CSMT cohort compared with the usual medical care cohort, with an OR (95% CI) of 0.53 (0.40 to 0.71; p<0.0001). Sensitivity analyses revealed early divergence in cumulative incidence of prescription; and no significant between-cohort difference in a negative control outcome (gastrointestinal medication) suggesting adequate control for pharmacological care preference. CONCLUSIONS: Our findings suggest that US adults receiving CSMT for newly diagnosed rLBP have significantly reduced odds of receiving a gabapentin prescription over 1-year follow-up compared with those receiving usual medical care. Results may not be generalisable and should be replicated in other healthcare settings and corroborated by a prospective study to reduce confounding.

Frequency of Parkinson disease following COVID-19 infection: A two-year retrospective cohort study.

INTRODUCTION: COVID-19 infection is known to cause various neurological symptoms, and potentially increases the risk of developing subsequent neurodegenerative conditions including parkinsonism. To our knowledge, no study to date has used a large data set in the United States to ascertain the risk of developing incident Parkinson disease in patients with history of COVID-19 infection compared to the risk amongst those without prior COVID-19 infection. METHODS: We utilized data from TriNetX electronic health records network which includes 73 healthcare organizations and over 107 million patients. We compared adult patients with and without COVID-19 infection, with health records from January 1, 2020 through July 26, 2022, to determine the relative risk of developing Parkinson disease stratified by 3-month intervals. We used propensity score matching to control for patients' age, sex, and smoking history. RESULTS: We collected data on 27,614,510 patients meeting our study criteria: 2,036,930 patients with a positive COVID-19 infection (COVID-19) and 25,577,580 without a positive COVID-19 infection (non-COVID-19). After propensity score matching, age, sex, and smoking history differences became non-significant, with 2,036,930 patients in each cohort. After propensity score matching, we found significantly increased odds of new onset Parkinson disease in the COVID-19 cohort at three, six, nine, and twelve months from the index event, with peak odds ratio at six months. After twelve months there is no significant difference between the COVID-19 group and non-COVID-19 group. CONCLUSIONS: There may be a transiently increased risk of developing Parkinson disease in the first year following COVID-19 infection.

Determination of Unnecessary Blood Transfusion by Comprehensive 15-Hospital Record Review.

BACKGROUND: Although unnecessary blood component transfusions are costly and pose substantial patient risks, the extent of unnecessary blood use in a community hospital setting has not been systematically measured. METHODS: A 15-hospital observational analysis was performed using comprehensive retrospective review. Approximately 100 encounters (x¯â€¯= 103.9, standard deviation [SD] ± 7.6) per hospital (6,696 total component transfusion events) were reviewed between 2012 and 2018. Review was performed by two medical directors. Findings were supported by blind intra- and inter-reviewer double review and blind external review by 10 independent reviewers. RESULTS: Patients received an average of 4.3 (± 1.3) units. Only 8.2% (± 6.7) of patient encounters did not receive unnecessary units. Fifty-five percent (54.6% ± 13.5) could have been managed without at least one component type, while 44.6% (± 14.9) could have been managed completely without transfusion. Forty-five percent (45.4% ± 17.0) of red blood cell, 54.9% (± 19.3) of plasma-cryoprecipitate, and 38.0% (± 15.6) of plateletpheresis encounters could likely have been managed without transfusion. Between 2,713 units (40.5%) and 3,306 units (49.4%) were likely unnecessary. In patients who could have been managed without transfusion of at least one component type, unnecessary blood use was associated with a 0.38 (± 0.11)-day increase in length of hospital stay for each additional unnecessary unit received (p < 0.001). CONCLUSION: Substantial unnecessary blood use was identified, all of which was unrecognized by hospitals prior to review. Unnecessary blood use was attributed to overreliance on laboratory transfusion criteria and failure to follow common blood management principles, which resulted in potential harm to patients and avoidable cost.

Association between chiropractic spinal manipulation and lumbar discectomy in adults with lumbar disc herniation and radiculopathy: retrospective cohort study using United States' data.

OBJECTIVES: Chiropractic spinal manipulative therapy (CSMT) and lumbar discectomy are both used for lumbar disc herniation (LDH) and lumbosacral radiculopathy (LSR); however, limited research has examined the relationship between these therapies. We hypothesised that adults receiving CSMT for newly diagnosed LDH or LSR would have reduced odds of lumbar discectomy over 1-year and 2-year follow-up compared with those receiving other care. DESIGN: Retrospective cohort study. SETTING: 101 million patient US health records network (TriNetX), queried on 24 October 2022, yielding data from 2012 query. PARTICIPANTS: Adults age 18-49 with newly diagnosed LDH/LSR (first date of diagnosis) were included. Exclusions were prior lumbar surgery, absolute indications for surgery, trauma, spondylolisthesis and scoliosis. Propensity score matching controlled for variables associated with the likelihood of discectomy (eg, demographics, medications). INTERVENTIONS: Patients were divided into cohorts according to receipt of CSMT. PRIMARY AND SECONDARY OUTCOME MEASURES: ORs for lumbar discectomy; calculated by dividing odds in the CSMT cohort by odds in the cohort receiving other care. RESULTS: After matching, there were 5785 patients per cohort (mean age 36.9±8.2). The ORs (95% CI) for discectomy were significantly reduced in the CSMT cohort compared with the cohort receiving other care over 1-year (0.69 (0.52 to 0.90), p=0.006) and 2-year follow-up (0.77 (0.60 to 0.99), p=0.040). E-value sensitivity analysis estimated the strength in terms of risk ratio an unmeasured confounding variable would need to account for study results, yielding point estimates for each follow-up (1 year: 2.26; 2 years: 1.92), which no variables in the literature reached. CONCLUSIONS: Our findings suggest receiving CSMT compared with other care for newly diagnosed LDH/LSR is associated with significantly reduced odds of discectomy over 2-year follow-up. Given socioeconomic variables were unavailable and an observational design precludes inferring causality, the efficacy of CSMT for LDH/LSR should be examined via randomised controlled trial to eliminate residual confounding.

Accuracy of Ultrasound Elastography and Fibrosis-4 Index (FIB-4) in Ruling Out Cirrhosis in Obese Non-Alcoholic Fatty Liver Disease (NAFLD) Patients.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of advanced liver disease in the USA. Liver biopsy, the gold standard diagnostic test for evaluating liver fibrosis, is associated with significant risk and expense. The accuracy of ultrasound elastography and Fibrosis-4 index (FIB-4) in the obese NAFLD population is unknown. We aimed to compare the accuracy of ultrasound elastography and FIB-4 to liver biopsy in ruling out cirrhosis in NAFLD patients at a tertiary, transplant referral center in the US. METHODS: We retrospectively evaluated 93 patients with a mean age of 53 years (SD: 13 years) who underwent liver ultrasound elastography and liver biopsy, and additionally calculated their FIB-4 at the time of biopsy. We compared the liver stiffness measurement (LSM) obtained from ultrasound elastography and FIB-4 with the pathology results for ruling out cirrhosis. RESULTS: 85% of the patients were white, 53% were female, average BMI was 34.7 (SD: 6.7), 52% had diabetes, and 53% had hypertension. For biopsy-proven cirrhosis (prevalence 15%), a cut-off value of 12.5 kilopascals (kPa) for F4 had a sensitivity of 92% and a specificity of 54%. Values below this threshold excluded cirrhosis with 98% certainty. Compared to FIB-4, ultrasound elastography showed higher accuracy in ruling out cirrhosis (92% vs. 80% sensitivity, 98% vs. 95% negative predictive value (NPV), respectively). CONCLUSION: To our knowledge, this is the first study in a tertiary transplant referral center in the USA to show that ultrasound elastography was superior to FIB-4 and can be used as a reliable screening test to rule out cirrhosis in obese NAFLD patients at a 12.5 kPa cut-off. Therefore, helping to avoid the risk and expense associated with liver biopsy.

Guideline-concordant utilization of magnetic resonance imaging in adults receiving chiropractic manipulative therapy vs other care for radicular low back pain: a retrospective cohort study.

BACKGROUND: Lumbar magnetic resonance imaging (LMRI) is often performed early in the course of care, which can be discordant with guidelines for non-serious low back pain. Our primary hypothesis was that adults receiving chiropractic spinal manipulative therapy (CSMT) for incident radicular low back pain (rLBP) would have reduced odds of early LMRI over 6-weeks' follow-up compared to those receiving other care (a range of medical care, excluding CSMT). As a secondary hypothesis, CSMT recipients were also expected to have reduced odds of LMRI over 6-months' and 1-years' follow-up. METHODS: A national 84-million-patient health records database including large academic healthcare organizations (TriNetX) was queried for adults age 20-70 with rLBP newly-diagnosed between January 31, 2012 and January 31, 2022. Receipt or non-receipt of CSMT determined cohort allocation. Patients with prior lumbar imaging and serious pathology within 90 days of diagnosis were excluded. Propensity score matching controlled for variables associated with LMRI utilization (e.g., demographics). Odds ratios (ORs) of LMRI over 6-weeks', 6-months', and 1-years' follow-up after rLBP diagnosis were calculated. RESULTS: After matching, there were 12,353 patients per cohort (mean age 50 years, 56% female), with a small but statistically significant reduction in odds of early LMRI in the CSMT compared to other care cohort over 6-weeks' follow-up (9%, 10%, OR [95% CI] 0.88 [0.81-0.96] P = 0.0046). There was a small but statistically significant increase in odds of LMRI among patients in the CSMT relative to the other care cohort over 6-months' (12%, 11%, OR [95% CI] 1.10 [1.02-1.19], P < 0.0174) and 1-years' follow-up (14%, 12%, OR [95% CI] 1.21 [1.13-1.31], P < 0.0001). CONCLUSIONS: These results suggest that patients receiving CSMT for newly-diagnosed rLBP are less likely to receive early LMRI than patients receiving other care. However, CSMT recipients have a small increase in odds of LMRI over the long-term. Both cohorts in this study had a relatively low rate of early LMRI, possibly because the data were derived from academic healthcare organizations. The relationship of these findings to other patient care outcomes and cost should be explored in a future randomized controlled trial. REGISTRATION: Open Science Framework ( https://osf.io/t9myp ).

Association between chiropractic spinal manipulative therapy and benzodiazepine prescription in patients with radicular low back pain: a retrospective cohort study using real-world data from the USA.

OBJECTIVES: Although chiropractic spinal manipulative therapy (CSMT) and prescription benzodiazepines are common treatments for radicular low back pain (rLBP), no research has examined the relationship between these interventions. We hypothesise that utilisation of CSMT for newly diagnosed rLBP is associated with reduced odds of benzodiazepine prescription through 12 months' follow-up. DESIGN: Retrospective cohort study. SETTING: National, multicentre 73-million-patient electronic health records-based network (TriNetX) in the USA, queried on 30 July 2021, yielding data from 2003 to the date of query. PARTICIPANTS: Adults aged 18-49 with an index diagnosis of rLBP were included. Serious aetiologies of low back pain, structural deformities, alternative neurological lesions and absolute benzodiazepine contraindications were excluded. Patients were assigned to cohorts according to CSMT receipt or absence. Propensity score matching was used to control for covariates that could influence the likelihood of benzodiazepine utilisation. OUTCOME MEASURES: The number, percentage and OR of patients receiving a benzodiazepine prescription over 3, 6 and 12 months' follow-up prematching and postmatching. RESULTS: After matching, there were 9206 patients (mean (SD) age, 37.6 (8.3) years, 54% male) per cohort. Odds of receiving a benzodiazepine prescription were significantly lower in the CSMT cohort over all follow-up windows prematching and postmatching (p<0.0001). After matching, the OR (95% CI) of benzodiazepine prescription at 3 months was 0.56 (0.50 to 0.64), at 6 months 0.61 (0.55 to 0.68) and 12 months 0.67 (0.62 to 0.74). Sensitivity analysis suggested a patient preference to avoid prescription medications did not explain the study findings. CONCLUSIONS: These findings suggest that receiving CSMT for newly diagnosed rLBP is associated with reduced odds of receiving a benzodiazepine prescription during follow-up. These results provide real-world evidence of practice guideline-concordance among patients entering this care pathway. Benzodiazepine prescription for rLBP should be further examined in a randomised trial including patients receiving chiropractic or usual medical care, to reduce residual confounding.

5'-Modifications improve potency and efficacy of DNA donors for precision genome editing.

Nuclease-directed genome editing is a powerful tool for investigating physiology and has great promise as a therapeutic approach to correct mutations that cause disease. In its most precise form, genome editing can use cellular homology-directed repair (HDR) pathways to insert information from an exogenously supplied DNA-repair template (donor) directly into a targeted genomic location. Unfortunately, particularly for long insertions, toxicity and delivery considerations associated with repair template DNA can limit HDR efficacy. Here, we explore chemical modifications to both double-stranded and single-stranded DNA-repair templates. We describe 5'-terminal modifications, including in its simplest form the incorporation of triethylene glycol (TEG) moieties, that consistently increase the frequency of precision editing in the germlines of three animal models (Caenorhabditis elegans, zebrafish, mice) and in cultured human cells.

Association between radicular low back pain and constipation: a retrospective cohort study using a real-world national database.

INTRODUCTION: Previous observational studies have reported an association between lumbosacral radiculopathy (LSR), a form of low back pain (LBP) with nerve root involvement, and constipation. However, it is unclear whether this association is due to confounding variables such as comorbidities and medications. OBJECTIVES: This study explores the possible association between LSR and constipation, with the hypothesis that adults with LSR have increased odds of developing constipation compared with those with nonradicular LBP. METHODS: Adults aged 18 to 49 years with incident LSR and nonradicular LBP were identified from a national 70 million patient electronic health records network (TriNetX). Propensity score matching (PSM) was used to control for covariates and determine the odds ratio (OR) of constipation over a 1-year follow-up. Lumbar stenosis, cauda equina syndrome, and inflammatory bowel diseases were excluded. RESULTS: After PSM, 503,062 patients were in each cohort. Before PSM, the likelihood of constipation was identical between cohorts (LSR 10.8% vs 10.9%; OR [confidence interval] = 0.99 [0.98-1.0], P = 0.251). This association was unchanged after PSM (LSR 10.8% vs 11.1%; OR [confidence interval] = 0.98 [0.97-0.99]; P = 0.003). CONCLUSIONS: The study hypothesis can be refuted given that the OR approximated the null in a large propensity-matched sample. Patients with LSR have equivalent odds of constipation compared with those with nonradicular LBP, suggesting that LSR is not a direct cause of constipation. The similar risk of constipation between cohorts could be explained by factors common to LBP in general, such as pain severity, physical inactivity, and constipating medications.

CK2-Dependent Phosphorylation of the Brg1 Chromatin Remodeling Enzyme Occurs during Mitosis.

Brg1 (Brahma-related gene 1) is one of two mutually exclusive ATPases that can act as the catalytic subunit of mammalian SWI/SNF (mSWI/SfigureNF) chromatin remodeling enzymes that facilitate utilization of the DNA in eukaryotic cells. Brg1 is a phospho-protein, and its activity is regulated by specific kinases and phosphatases. Previously, we showed that Brg1 interacts with and is phosphorylated by casein kinase 2 (CK2) in a manner that regulates myoblast proliferation. Here, we use biochemical and cell and molecular biology approaches to demonstrate that the Brg1-CK2 interaction occurred during mitosis in embryonic mouse somites and in primary myoblasts derived from satellite cells isolated from mouse skeletal muscle tissue. The interaction of CK2 with Brg1 and the incorporation of a number of other subunits into the mSWI/SNF enzyme complex were independent of CK2 enzymatic activity. CK2-mediated hyperphosphorylation of Brg1 was observed in mitotic cells derived from multiple cell types and organisms, suggesting functional conservation across tissues and species. The mitotically hyperphosphorylated form of Brg1 was localized with soluble chromatin, demonstrating that CK2-mediated phosphorylation of Brg1 is associated with specific partitioning of Brg1 within subcellular compartments. Thus, CK2 acts as a mitotic kinase that regulates Brg1 phosphorylation and subcellular localization.

A Compact, High-Accuracy Cas9 with a Dinucleotide PAM for In Vivo Genome Editing.

CRISPR-Cas9 genome editing has transformed biotechnology and therapeutics. However, in vivo applications of some Cas9s are hindered by large size (limiting delivery by adeno-associated virus [AAV] vectors), off-target editing, or complex protospacer-adjacent motifs (PAMs) that restrict the density of recognition sequences in target DNA. Here, we exploited natural variation in the PAM-interacting domains (PIDs) of closely related Cas9s to identify a compact ortholog from Neisseria meningitidis-Nme2Cas9-that recognizes a simple dinucleotide PAM (N4CC) that provides for high target site density. All-in-one AAV delivery of Nme2Cas9 with a guide RNA targeting Pcsk9 in adult mouse liver produces efficient genome editing and reduced serum cholesterol with exceptionally high specificity. We further expand our single-AAV platform to pre-implanted zygotes for streamlined generation of genome-edited mice. Nme2Cas9 combines all-in-one AAV compatibility, exceptional editing accuracy within cells, and high target site density for in vivo genome editing applications.

MED20 is essential for early embryogenesis and regulates NANOG expression.

Mediator is an evolutionarily conserved multi-subunit complex, bridging transcriptional activators and repressors to the general RNA polymerase II (Pol II) initiation machinery. Though the Mediator complex is crucial for the transcription of almost all Pol II promoters in eukaryotic organisms, the phenotypes of individual Mediator subunit mutants are each distinct. Here, we report for the first time, the essential role of subunit MED20 in early mammalian embryo development. Although Med20 mutant mouse embryos exhibit normal morphology at E3.5 blastocyst stage, they cannot be recovered at early post-gastrulation stages. Outgrowth assays show that mutant blastocysts cannot hatch from the zona pellucida, indicating impaired blastocyst function. Assessments of cell death and cell lineage specification reveal that apoptosis, inner cell mass, trophectoderm and primitive endoderm markers are normal in mutant blastocysts. However, the epiblast marker NANOG is ectopically expressed in the trophectoderm of Med20 mutants, indicative of defects in trophoblast specification. These results suggest that MED20 specifically, and the Mediator complex in general, are essential for the earliest steps of mammalian development and cell lineage specification.