The rockefeller university

Background There is a presumption that, for patients with uncontrolled blood pressure (BP), early follow-up, that is, within 4 weeks of an elevated reading, improves BP control. However, data are lacking regarding effective interventions for increasing clinician frequency of follow-up visits and whether such interventions improve BP control. Methods/design Blood Pressure Visit Intensification Study in Treatment involves a multimodal approach to improving intensity of follow-up in 12 community health centers using a stepped wedge study design. Discussion The study will inform effective interventions for increasing frequency of follow-up visits among patients with uncontrolled BP and determine whether increasing follow-up frequency is associated with better BP control.

SETTING: Tuberculosis spondylodiscitis (TS), or Pott's disease, an extra-pulmonary form of tuberculosis (TB), is rare and difficult to diagnose in children. Some cases of severe TB in children were recently explained by inborn errors of immunity affecting the interleukin-12/interferon-gamma (IL-12/IFN-gamma) axis. OBJECTIVE: To analyse clinical data on Moroccan children with TS, and to perform immunological and genetic explorations of the IL-12/IFN-gamma axis. DESIGN: We studied nine children with TS diagnosed between 2012 and 2014. We investigated the LL-12/IFN-gamma circuit by both whole-blood assays and sequencing of the coding regions of 14 core genes of this pathway. RESULTS: A diagnosis of TS was based on a combination of clinical, biological, histological and radiological data. QuantiFERON (R)-TB Gold In-Tube results were positive in 75% of patients. Whole-blood assays showed normal IL-12 and IFN-gamma production in all but one patient, who displayed impaired decreased response to IL-12. No candidate disease-causing mutations were detected in the exonic regions of the 14 genes. CONCLUSIONS: TS diagnosis in children remains challenging, and is based largely on imaging. Further investigations of TS in children are required to determine the role of genetic defects in pathways that may or may not be related to the IL-12/IFN-gamma axis.

Background: Oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) isolates have been increasingly reported worldwide, but data regarding the African continent have not been available. Methods: Between 2010 and 2014, 1462 inpatients and healthcare workers were screened for MRSA nasal carriage in Sao Tome and Principe (STP) and Angola, two Portuguese-speaking African countries (PALOP countries). We determined the presence of the mecA gene and the antimicrobial susceptibility profiles of the isolates. OS-MRSA clonal lineages were identified as well as the presence of virulence determinants, including Panton-Valentine leucocidin (PVL). Results: Out of 164 S. aureus hospital isolates tested, 29 (17.7%) were mecA positive, but susceptible to oxacillin, showing oxacillin MICs <= 3 mg/L. All OS-MRSA isolates were resistant to cefoxitin and most of them were also resistant to at least two antimicrobials other than beta-lactams. The 29 OS-MRSA were distributed into two major clonal lineages: (i) PFGE type B-ST88-SCCmec IVa, associated with spa types t186/t325/t786/t1814/t1951, detected in Angola (n = 5) and STP (n = 10); and (ii) PFGE type C-t451/t648-ST8-SCCmec V, exclusively found in STP (n = 9). OS-MRSA showed at least two virulence determinants. PVL was detected in an isolate recovered in STP. Conclusions: We describe a high prevalence of OS-MRSA among S. aureus strains recovered in two African countries. OS-MRSA in PALOP countries were mainly associated with ST88 and ST8, two prevalent MRSA clonal types in these countries. If direct testing for mecA is not available, cefoxitin susceptibility testing is highly recommended to avoid the misidentification of OS-MRSA.

A great deal of interest has been focused recently on the habenula and its critical role in aversion, negative-reward and drug dependence. Using a conditional mouse model of the ACh-synthesizing enzyme choline acetyltransferase (Chat), we report that local elimination of acetylcholine (ACh) in medial habenula (MHb) neurons alters glutamate corelease and presynaptic facilitation. Electron microscopy and immuno-isolation analyses revealed colocalization of ACh and glutamate vesicular transporters in synaptic vesicles (SVs) in the central IPN. Glutamate reuptake in SVs prepared from the IPN was increased by ACh, indicating vesicular synergy. Mice lacking CHAT in habenular neurons were insensitive to nicotine-conditioned reward and withdrawal. These data demonstrate that ACh controls the quantal size and release frequency of glutamate at habenular synapses, and suggest that the synergistic functions of ACh and glutamate may be generally important for modulation of cholinergic circuit function and behavior.

Streptococcus pyogenes chromosomal island M1 (SpyCIM1) integrates by site-specific recombination into the 5' end of DNA mismatch repair (MMR) gene mutL in strain SF370SmR, blocking transcription of it and the downstream operon genes. During exponential growth, SpyCIM1 excises from the chromosome and replicates as an episome, restoring mutL transcription. This process is reversed in stationary phase with SpyCIM1 re-integrating into mutL, returning the cells to a mutator phenotype. Here we show that elimination of SpyCIM1 relieves this mutator phenotype. The downstream MMR operon genes, multidrug efflux pump lmrP, Holliday junction resolution helicase ruvA, and DNA base excision repair glycosylase tag, are also restored to constitutive expression by elimination of SpyCIM1. The presence of SpyCIM1 alters global transcription patterns in SF370SmR. RNA sequencing (RNA-Seq) demonstrated that loss of SpyCIM1 in the SpyCIM1 deletion mutant, CEM1 Delta 4, impacted the expression of over 100 genes involved in virulence and metabolism both in early exponential phase, when the SpyCIM1 is episomal, as well as at the onset of stationary phase, when SpyCIM1 has reintegrated into mutL. Among these changes, the up-regulation of the genes for the antiphagocytic M protein (emm1), streptolysin O (slo), capsule operon (hasABC), and streptococcal pyrogenic exotoxin (speB), are particularly notable. The expression pattern of the MMR operon confirmed our earlier observations that these genes are transcribed in early exponential phase but silenced as stationary phase is approached. Thus, the direct role of SpyCIM1 in causing the mutator phenotype is confirmed, and further, its influence upon the biology of S. pyogenes was found to impact multiple genes in addition to the MMR operon, which is a novel function for a mobile genetic element. We suggest that such chromosomal islands are a remarkable evolutionary adaptation to promote the survival of its S. pyogenes host cell in changing environments.

We study the behaviour of double-stranded RNA eunder twist and tension using oxRNA, a recently developed coarse-grained model of RNA. Introducing explicit salt-dependence into the model allows us to directly compare our results to data from recent single-molecule experiments. The model reproduces extension curves as a function of twist and stretching force, including the buckling transition and the behaviour of plectoneme structures. For negative supercoiling, we predict denaturation bubble formation in plectoneme end-loops, suggesting preferential plectoneme localisation in weak base sequences. OxRNA exhibits a positive twist-stretch coupling constant, in agreement with recent experimental observations. (C) 2015 AIP Publishing LLC.

Commissural axon guidance depends on a myriad of cues expressed by intermediate targets. Secreted semaphorins signal through neuropilin-2/plexin-A1 receptor complexes on post-crossing commissural axons to mediate floor plate repulsion in the mouse spinal cord. Here, we show that neuropilin-2/plexin-A1 are also coexpressed on commissural axons prior to midline crossing and can mediate precrossing semaphorin-induced repulsion in vitro. How premature semaphorin-induced repulsion of precrossing axons is suppressed in vivo is not known. We discovered that a novel source of floor plate-derived, but not axon-derived, neuropilin-2 is required for precrossing axon pathfinding. Floor plate-specific deletion of neuropilin-2 significantly reduces the presence of precrossing axons in the ventral spinal cord, which can be rescued by inhibiting plexin-A1 signaling in vivo. Our results show that floor plate-derived neuropilin-2 is developmentally regulated, functioning as a molecular sink to sequester semaphorins, preventing premature repulsion of precrossing axons prior to subsequent down-regulation, and allowing for semaphorin-mediated repulsion of post-crossing axons.

The development of therapies and vaccines for human hepatropic pathogens requires robust model systems that enable the study of host-pathogen interactions. However, in vitro liver models of infection typically use either hepatoma cell lines that exhibit aberrant physiology or primary human hepatocytes in culture conditions in which they rapidly lose their hepatic phenotype. To achieve stable and robust in vitro primary human hepatocyte models, we developed micropatterned cocultures (MPCCs), which consist of primary human hepatocytes organized into 2D islands that are surrounded by supportive fibroblast cells. By using this system, which can be established over a period of days, and maintained over multiple weeks, we demonstrate how to recapitulate in vitro hepatic life cycles for the hepatitis B and C viruses and the Plasmodium pathogens P. falciparum and P. vivax. The MPCC platform can be used to uncover aspects of host-pathogen interactions, and it has the potential to be used for drug and vaccine development.