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Missense variants are a major source of human genetic variation. Here we analyze a new mouse missense variant, Rasgrp1Anaef, with an ENU-mutated EF hand in the Rasgrp1 Ras guanine nucleotide exchange factor. Rasgrp1Anaef mice exhibit anti-nuclear autoantib

The modern management of colonic diverticular disease involves grouping patients into uncomplicated or complicated diverticulitis, after which the correct treatment paradigm is instituted. Recent controversies suggest overlap in management strategies between these two groups. While most reports still support surgical intervention for the treatment of complicated diverticular disease, more data are forthcoming suggesting complicated diverticulitis does not merit surgical resection in all scenarios. Given the significant risk for complication in surgery for diverticulitis, careful attention should be paid to patient and procedure selection. Here, we define complicated diverticulitis, discuss options for surgical intervention, and explain strategies for avoiding operative pitfalls that result in early and late postoperative complications., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Background: Mesh weight is a possible contributor to quality-of-life outcomes after inguinal hernia repair. This study compares lightweight mesh versus heavyweight mesh in laparoscopic inguinal hernia repair., Methods: A prospective, single-center, hernia-specific database was queried for all adult laparoscopic inguinal hernia repair with three-dimensional contoured mesh (3-D Max, Bard, Inc, New Providence, NJ) from 1999 to June 2016. Demographics and outcomes were analyzed. Quality of life was evaluated preoperatively and after 2 weeks, 4 weeks, 6 months, 12 months, and 24 months, using the Carolinas Comfort Scale. Univariate analysis and multivariate logistic regression were performed., Results: A total of 1,424 laparoscopic inguinal hernia repair were performed with three-dimensional contoured mesh, with 804 patients receiving lightweight mesh and 620 receiving heavyweight mesh. Patients receiving lightweight mesh were somewhat younger (52.6 ± 14.8 years vs 56.3 ± 13.7 years, P < .0001), with slightly lower body mass indices (26.4 ± 9.9 vs 27.1 ± 4.3, P < .0001). Lightweight mesh was used less often in incarcerated hernias (12.5% vs 16.8%, P = .02). There were a total of 3 surgical site infections. There were no differences in complications between groups except for seroma. Although on univariate analysis, seromas appeared to occur more frequently with heavyweight mesh (21.5% vs 7.9%). On multivariate analysis, heavyweight mesh was not independently associated with seroma formation. Average follow-up was 20 months. Recurrence rates were similar between lightweight mesh and heavyweight mesh (0.7 vs 0.6% P > .05). At all points of follow-up (4 week to 3 years), quality-of-life outcomes of discomfort, mesh sensation, and movement limitation scores were similar between lightweight mesh and heavyweight mesh., Conclusion: Contoured lightweight mesh and heavyweight mesh in laparoscopic inguinal hernia repair yield excellent recurrence rates and no difference in postoperative complications or quality of life. Considering the lack of outcome difference with long-term follow-up, heavyweight mesh may be considered for use in laparoscopic inguinal hernia repair patients., (Copyright © 2018. Published by Elsevier Inc.)

Background: For cirrhotic patients awaiting liver transplantation, the Model for End-Stage Liver Disease Sodium (MELD-Na) model is extensively studied. Because of the simplicity of the scoring system, there has been interest in applying MELD-Na to predict patient outcomes in the noncirrhotic surgical patient, and MELD-Na has been shown to predict postoperative morbidity and mortality after elective colectomy. Our aim was to identify the utility of MELD-Na to predict anastomotic leak in elective colorectal cases., Methods: The American College of Surgeons National Surgical Quality Improvement Program targeted colectomy database was queried (2012-2014) for all elective colorectal procedures in patients without ascites. Leak rates were compared by MELD-Na score using chi-square tests and multivariate logistic regression analysis., Results: We identified 44,540 elective colorectal cases (mean age, 60.5 y ± 14.4, mean body mass index 28.8 ± 6.6 kg/m 2 , 52% female), of which 70% were colon resections and 30% involved partial rectal resections (low anterior resections). Laparoscopic approach accounted for 64.72% while 35.3% were open. The overall complication and mortality rates were 21% and 0.7%, respectively, with a total anastomotic leak rate of 3.4%. Overall, 98% had a preoperative MELD-Na score between 10 and 20. Incremental increases in MELD-Na score (10-14, 15-19, and ≥20) were associated with an increased leak rate, specifically in partial rectal resections (3.9% versus 5.1% versus 10.7% P <0.028). MELD-Na score ≥20 had an increased leak rate when compared with those with MELD-Na 10-14 (odds ratio [OR] 1.627; 95% confidence interval [CI] [1.015, 2.607]). An MELD-Na score increase from 10-14 to 15-19 increases overall mortality (OR 5.22; 95% CI [3.55, 7.671]). In all elective colorectal procedures, for every one-point increase in MELD-Na score, anastomotic leak (OR 1.04 95% CI [1.006, 1.07]), mortality (OR 1.24; 95% CI, [1.20, 1.27]), and overall complications (OR 1.10; 95% CI [1.09, 1.12]) increased. MELD-Na was an independent predictor of anastomotic leak in partial rectal resections, when controlling for gender, steroid use, smoking, approach, operative time, preoperative chemotherapy, and Crohn's disease (OR 1.06, 95% CI [1.002, 1.122])., Conclusions: MELD-Na is an independent predictor of anastomotic leak in partial rectal resections. Anastomotic leak risk increases with increasing MELD-Na in elective colorectal resections, as does 30-d mortality and overall complication rate. As MELD-Na score increases to more than 20, restorative partial rectal resection has a 10% rate of anastomotic leak., (Copyright © 2018. Published by Elsevier Inc.)

Introduction: Roux-En-Y gastric bypass (RYGB) is an alternative to reoperative fundoplication. The aim of this study was to expand long-term outcomes of patients undergoing RYGB after failed fundoplication and assess symptom resolution., Methods: A single institution prospective study was performed of patients undergoing fundoplication takedown and RYGB between March 2007 and September 2016. Demographics, body mass index (BMI), preoperative symptoms, operative duration and findings, and postoperative outcomes were recorded. Data were assessed using standard statistical methods., Results: 87 patients with failed antireflux surgery underwent RYGB. Median age 58 years (range 25-79 years). Median preoperative BMI 32.4 kg/m 2 (range 21.6-50.6 kg/m 2 ). Comorbidities included hypertension (48.3%) and diabetes (11.5%). Sixty-six patients had undergone 1 prior fundoplication, 18 had 2 prior fundoplications, and 3 had 3 prior fundoplications. At least one previous open antireflux procedure had been performed in 16.1% of patients. The most common recurrent symptoms were reflux (85.1%), dysphagia (36.7%), pain (35.6%), and regurgitation (29.9%). Median symptom-free interval from last antireflux surgery was 3 years (range 0-25 years). RYGB was performed laparoscopically in 47.1% of cases, robotically in 44.8% of cases, and open in 5.9%. Operative duration was longer in the robotic group (p = 0.04). During RYGB, 85.1% patients were found to have an associated hiatal hernia, 34.5% had intrathoracic migration of the fundoplication, 32.2% a slipped fundoplication onto proximal stomach, and 13.8% had wrap disruption. Median length of stay (LOS) was 4 days (range 1-33 days). Median follow-up was 35.8 months, 11 patients (12.6%) had recurrent reflux symptoms. Excess body weight loss (%EWL) was 80.4%. There was no mortality but 8 patients required reoperation during follow-up., Conclusions: Fundoplication takedown with RYGB was successful for long-term reflux resolution. Most can be performed via a minimally invasive approach with acceptable perioperative morbidity, symptom resolution, and the additional benefit of %EWL.

Background: Despite improvement in technique and technology, using prophylactic ureteral catheters to avoid iatrogenic ureteral injury during colectomy remains controversial., Objective: The aim of this study was to evaluate outcomes and costs attributable to prophylactic ureteral catheters with colectomy., Design: This was a retrospective study., Settings: The study was conducted at a single tertiary care center., Patients: The colectomy-targeted American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2014 was queried., Main Outcome Measures: The primary end point was the rate of 30-day ureteral injury after colectomy. Univariate and multivariate analyses determined factors associated with ureteral injury and urinary tract infection in patients undergoing colectomy., Results: A total of 51,125 patients were identified with a mean age of 60.9 ± 14.9 years and a BMI of 28.4 ± 6.7 k/m; 4.90% (n = 2486) of colectomies were performed with prophylactic catheters, and 333 ureteral injuries (0.65%) were identified. Prophylactic ureteral catheters were most commonly used for diverticular disease (42.2%; n = 1048), with injury occurring most often during colectomy for diverticular disease (36.0%; n = 120). Univariate analysis of outcomes demonstrated higher rates of ileus, wound infection, urinary tract infection, urinary tract infection as reason for readmission, superficial site infection, and 30-day readmission in patients with prophylactic ureteral catheter placement. On multivariate analysis, prophylactic ureteral catheter placement was associated with a lower rate of ureteral injury (OR = 0.45 (95% CI, 0.25-0.81))., Limitations: This was a retrospective study using a clinical data set., Conclusions: Here, prophylactic ureteral catheters were used in 4.9% of colectomies and most commonly for diverticulitis. On multivariate analysis, prophylactic catheter placement was associated with a lower rate of ureteral injury. Additional research is needed to delineate patient populations most likely to benefit from prophylactic ureteral stent placement. See Video Abstract at http://links.lww.com/DCR/A482.

Background: The purpose of this study was to examine outcomes of robotic ventral hernia repair(RVHR) versus laparoscopic ventral hernia repair(LVHR)., Methods: The Nationwide Inpatient Sample was queried from October 2008 to December 2013 for ventral hernia repairs. Demographics, morbidity, mortality, and charges were compared between RVHR and LVHR., Results: From 2008-2013, 149,622 ventral hernia surgeries were identified; 117,028 open, 32,243 laparoscopic, and 351 robotic. Open repairs were excluded. RVHR rose annually with 2013 containing 47.9% of all RVHRs. RVHR patients were more likely to be older and have more chronic conditions. There was no difference between length of stay. Pneumonia rates were higher with RVHR; however, after controlling for confounding variables, there was no difference in pneumonia rates. Mortality and other major complications were similar. Total charges were increased for RVHR in univariate and multivariate analysis. RVHR was more common in teaching hospitals and wealthier zip codes., Conclusion: RVHR demonstrates comparable safety to the laparoscopic technique, with increased charges and increased volume in urban teaching hospitals and patients from areas of higher median income., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Missense variants are a major source of human genetic variation. Here we analyze a new mouse missense variant, Rasgrp1(Anaef), with an ENU-mutated EF hand in the Rasgrp1 Ras guanine nucleotide exchange factor. Rasgrp1(Anaef) mice exhibit anti-nuclear autoantibodies and gradually accumulate a CD44(hi) Helios(+) PD-1(+) CD4(+) T cell population that is dependent on B cells. Despite reduced Rasgrp1-Ras-ERK activation in vitro, thymocyte selection in Rasgrp1(Anaef) is mostly normal in vivo, although CD44 is overexpressed on naïve thymocytes and T cells in a T-cell-autonomous manner. We identify CD44 expression as a sensitive reporter of tonic mTOR-S6 kinase signaling through a novel mouse strain, chino, with a reduction-of-function mutation in Mtor. Elevated tonic mTOR-S6 signaling occurs in Rasgrp1(Anaef) naïve CD4(+) T cells. CD44 expression, CD4(+) T cell subset ratios and serum autoantibodies all returned to normal in Rasgrp1(Anaef)Mtor(chino) double-mutant mice, demonstrating that increased mTOR activity is essential for the Rasgrp1(Anaef) T cell dysregulation. DOI: http://dx.doi.org/10.7554/eLife.01020.001.

To assess the effect of human umbilical cord blood (hUCB) transplantation on neuromuscular transmission in SOD1(G93A) transgenic mice, we studied the probability of neuromuscular transmission (PNMT), a relevant physiological indicator of motor nerve function, in 3 SOD1(G93A) mice transplanted with hUCB and compared to PNMT in 4 SOD1(G93A) mice without cell transplantation and 3 non-mutant SOD1 transgenic mice. For preparations isolated from non-mutant SOD1 transgenic mice, PNMT was 0.93 and 0.84 during the first 5 s of 70 and 90 Hz trains, respectively. PNMT gradually declined to 0.77 and 0.42 at the end of the trains. In striking contrast, PNMT for preparations from non-treated mutant SOD1(G93A) mice was 0.52 and 0.36 in the first 5 s of 70 and 90 Hz trains, respectively (p<0.05). Treatment with hUCB significantly (p<0.05) improved PNMT in SOD1(G93A) preparations. That is, the initial 5 s PNMT was 0.88 and 0.68 for the 70 and 90 Hz stimuli, respectively. We concluded that hUCB transplantation significantly improved PNMT for muscles removed from SOD1(G93A) mice. Testing PNMT in the SOD1(G93A) mouse model could be used as a simple in vitro protocol to detect a positive cellular response to therapeutic interventions in ALS.

Recent studies from our laboratory have shown that intravenous administration of human umbilical cord blood (HUCB) mononuclear cells to mice improved blood glucose levels, survival, atherosclerosis and prostate cancer. In this study, we examined the effect of HUCB cells on the production of IL-10 levels in IL-10 knockout mice. It has been proposed that administration of IL-10 may be beneficial in the treatment of inflammatory bowl disease. The results show that mice treated with HUCB cells (100 x 10(6)) produce IL-10, as demonstrated by both qualitative and quantitative analyses, and that the levels of this cytokine persisted until the mice were sacrificed (5.5 months after administration). Immunohistochemical staining of the intestine using HuNu antibody cocktail demonstrated the presence of HUCB cells in the knockout mouse. Although the mice did not receive any immunosuppression, there was no evidence of graft-versus-host disease. Our data suggest that HUCB cells are capable of producing IL-10, and the use of these cells or HUCB may be indicated in the treatment of certain human diseases.

DNA ligase IV (LIG4) is an essential component of the nonhomologous end-joining (NHEJ) repair pathway and plays a key role in V(D)J recombination. Hypomorphic LIG4 mutations in humans are associated with increased cellular radiosensitivity, microcephaly, facial dysmorphisms, growth retardation, developmental delay, and a variable degree of immunodeficiency. We have generated a knock-in mouse model with a homozygous Lig4 R278H mutation that corresponds to the first LIG4 mutation reported in humans. The phenotype of homozygous mutant mice Lig4(R278H/R278H) (Lig4(R/R)) includes growth retardation, a decreased life span, a severe cellular sensitivity to ionizing radiation, and a very severe, but incomplete block in T and B cell development. Peripheral T lymphocytes show an activated and anergic phenotype, reduced viability, and a restricted repertoire, reminiscent of human leaky SCID. Genomic instability is associated with a high rate of thymic tumor development. Finally, Lig4(R/R) mice spontaneously produce low-affinity antibodies that include autoreactive specificities, but are unable to mount high-affinity antibody responses. These findings highlight the importance of LIG4 in lymphocyte development and function, and in genomic stability maintenance, and provide a model for the complex phenotype of LIG4 syndrome in humans.

The cascade comprising Raf, mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK) is a therapeutic target in human cancers with deregulated Ras signalling, which includes tumours that have inactivated the Nf1 tumour suppressor. Nf1 encodes neurofibromin, a GTPase-activating protein that terminates Ras signalling by stimulating hydrolysis of Ras-GTP. We compared the effects of inhibitors of MEK in a myeloproliferative disorder (MPD) initiated by inactivating Nf1 in mouse bone marrow and in acute myeloid leukaemias (AMLs) in which cooperating mutations were induced by retroviral insertional mutagenesis. Here we show that MEK inhibitors are ineffective in MPD, but induce objective regression of many Nf1-deficient AMLs. Drug resistance developed because of outgrowth of AML clones that were present before treatment. We cloned clone-specific retroviral integrations to identify candidate resistance genes including Rasgrp1, Rasgrp4 and Mapk14, which encodes p38alpha. Functional analysis implicated increased RasGRP1 levels and reduced p38 kinase activity in resistance to MEK inhibitors. This approach represents a robust strategy for identifying genes and pathways that modulate how primary cancer cells respond to targeted therapeutics and for probing mechanisms of de novo and acquired resistance.

Nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks (DSBs) during V(D)J recombination in developing lymphocytes and during immunoglobulin (Ig) heavy chain (IgH) class switch recombination (CSR) in peripheral B lymphocytes. We now show that CD21-cre-mediated deletion of the Xrcc4 NHEJ gene in p53-deficient peripheral B cells leads to recurrent surface Ig-negative B lymphomas ("CXP lymphomas"). Remarkably, CXP lymphomas arise from peripheral B cells that had attempted both receptor editing (secondary V[D]J recombination of Igkappa and Iglambda light chain genes) and IgH CSR subsequent to Xrcc4 deletion. Correspondingly, CXP tumors frequently harbored a CSR-based reciprocal chromosomal translocation that fused IgH to c-myc, as well as large chromosomal deletions or translocations involving Igkappa or Iglambda, with the latter fusing Iglambda to oncogenes or to IgH. Our findings reveal peripheral B cells that have undergone both editing and CSR and show them to be common progenitors of CXP tumors. Our studies also reveal developmental stage-specific mechanisms of c-myc activation via IgH locus translocations. Thus, Xrcc4/p53-deficient pro-B lymphomas routinely activate c-myc by gene amplification, whereas Xrcc4/p53-deficient peripheral B cell lymphomas routinely ectopically activate a single c-myc copy.

The accumulation of misfolded proteins stresses the endoplasmic reticulum (ER) and triggers cell death through activation of the multidomain proapoptotic BCL-2 proteins BAX and BAK at the outer mitochondrial membrane. The signaling events that connect ER stress with the mitochondrial apoptotic machinery remain unclear, despite evidence that deregulation of this pathway contributes to cell loss in many human degenerative diseases. In order to "trap" and identify the apoptotic signals upstream of mitochondrial permeabilization, we challenged Bax-/- Bak-/- mouse embryonic fibroblasts with pharmacological inducers of ER stress. We found that ER stress induces proteolytic activation of the BH3-only protein BID as a critical apoptotic switch. Moreover, we identified caspase-2 as the premitochondrial protease that cleaves BID in response to ER stress and showed that resistance to ER stress-induced apoptosis can be conferred by inhibiting caspase-2 activity. Our work defines a novel signaling pathway that couples the ER and mitochondria and establishes a principal apoptotic effector downstream of ER stress.

Effectiveness against chloroquine-resistant Plasmodia makes mefloquine a widely used antimalarial drug. However, mefloquine's neurologic effects offset this therapeutic advantage. Cellular actions which might contribute to the neurologic effects of mefloquine are not understood. Structural similarity to tacrine suggested that mefloquine might alter cholinergic synaptic transmission. Therefore, we examined mefloquine's effects at a model cholinergic synapse. Triangularis sterni nerve-muscle preparations were isolated from adult mice and examined with sharp electrode current clamp technique. Within 30 min of exposure to 10 microM mefloquine, miniature endplate potentials (mepps) occurred in summating bursts and their mean frequency increased 10-fold. The threshold concentration for the increase of mean mepp frequency was 0.6 microM mefloquine. Mefloquine continued to increase mean mepp frequency for preparations bathed in extracellular solution lacking Ca2+. In contrast, mefloquine no longer increased mean mepp frequency for preparations pre-treated with the intracellular Ca2+ buffer BAPTA-AM. Although mefloquine disrupts a thapsigargin-sensitive neuronal Ca2+ store, pre-treatment with thapsigargin did not alter the mefloquine-induced alterations of mepps. Since mefloquine, like oligomycin, inhibits mitochondrial FOF1H+ ATP synthase we tested the interaction between these two chemicals. Like mefloquine, oligomycin induced bursts and increased mean frequency of mepps. Furthermore, pre-treatment with oligomycin precluded the mefloquine-induced alterations of asynchronous transmsitter release. These data suggest that mefloquine inhibits ATP production which increases the concentration of Ca2+ within the cytosol of nerve terminals. This elevation of Ca2+ concentration selectively increases asynchronous transmitter release since 10 microM mefloquine did not alter stimulus-evoked transmsitter release.

Mefloquine is effective against drug-resistant Plasmodium falciparum. This property, along with its unique pharmacokinetic profile, makes mefloquine a widely prescribed antimalarial drug. However, mefloquine has neurologic effects which offset its therapeutic advantages. Cellular actions underlying mefloquine's neurologic effects are poorly understood. Here, we demonstrate that mefloquine inhibits human recombinant acetylcholinesterase. To explore the consequences of this action, we investigated mefloquine's actions at a model cholinergic synapse, the mouse neuromuscular junction. Sharp electrode recording was used to record miniature endplate potentials (mepps) in the Triangularis sterni muscle. Within 30 min of exposure to 10 microM mefloquine, mepps were altered in three ways: 10-90% rise time, 90-10% decay time and amplitude significantly increased. Mepp decay time increased linearly with mefloquine concentration. Pretreatment of muscles with the cholinesterase inhibitor physostigmine (3 microM) precluded the mefloquine-induced prolongation of mepp decay. Mefloquine also prolonged mepps at endplates of acetylcholinesterase knock-out mice. Since the selective butyrylcholinesterase inhibitor iso-OMPA (100 microM) also prolonged mepp decay at the neuromuscular junction of acetylcholinesterase knock-out mice, mefloquine inhibition of this enzyme is physiologically relevant. The non-selective anti-cholinesterase action can contribute to the neurologic effects of mefloquine.

We demonstrate a method for embossing titania sol--gel precursor with poly(methyl methacrylate) (PMMA) molds to make thin films of titania that have dense arrays of 35--65 nm diameter pores, whose features are 1 order of magnitude smaller than those previously demonstrated for sol--gel molding. We show that the high modulus of PMMA is necessary to preserve small features with high aspect ratios on the mold for nanopatterning. The molds are prepared by thermally infiltrating PMMA into anodic alumina templates, whose pore dimensions and depths are adjustable by varying anodization conditions. The difficulties associated with mold release from a master are avoided by wet etching the template. These titania films, and others made with other semiconductors, could be useful for photovoltaic, photocatalytic, and sensing applications where nanostructuring of surfaces with controlled dimensions are essential.