Summary Bacterial meningitis continues to be an important cause of mortality and morbidity in neonates and children throughout the world. The introduction of the protein conjugate vaccines against ...Haemophilus influenzae type b, Streptococcus pneumoniae , and Neisseria meningitidis has changed the epidemiology of bacterial meningitis. Suspected bacterial meningitis is a medical emergency and needs empirical antimicrobial treatment without delay, but recognition of pathogens with increasing resistance to antimicrobial drugs is an important factor in the selection of empirical antimicrobial regimens. At present, strategies to prevent and treat bacterial meningitis are compromised by incomplete understanding of the pathogenesis. Further research on meningitis pathogenesis is thus needed. This Review summarises information on the epidemiology, pathogenesis, new diagnostic methods, empirical antimicrobial regimens, and adjunctive treatment of acute bacterial meningitis in infants and children.
Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality. Microbial invasion and traversal of the blood-brain barrier is a prerequisite for CNS infections. ...Pathogens can cross the blood-brain barrier transcellularly, paracellularly and/or in infected phagocytes (the so-called Trojan-horse mechanism). Consequently, pathogens can cause blood-brain barrier dysfunction, including increased permeability, pleocytosis and encephalopathy. A more complete understanding of the microbial-host interactions that are involved in microbial traversal of the blood-brain barrier and the associated barrier dysfunction should help to develop new strategies to prevent CNS infections.
In patients with acute myocardial infarction receiving potent antiplatelet therapy, the bleeding risk remains high during the maintenance phase. We sought data on a uniform unguided de-escalation ...strategy of dual antiplatelet therapy (DAPT) from ticagrelor to clopidogrel after acute myocardial infarction.
In this open-label, assessor-masked, multicentre, non-inferiority, randomised trial (TALOS-AMI), patients at 32 institutes in South Korea with acute myocardial infarction receiving aspirin and ticagrelor without major ischaemic or bleeding events during the first month after index percutaneous coronary intervention (PCI) were randomly assigned in a 1:1 ratio to a de-escalation (clopidogrel plus aspirin) or active control (ticagrelor plus aspirin) group. Unguided de-escalation without a loading dose of clopidogrel was adopted when switching from ticagrelor to clopidogrel. The primary endpoint was a composite of cardiovascular death, myocardial infarction, stroke, or bleeding type 2, 3, or 5 according to Bleeding Academic Research Consortium (BARC) criteria from 1 to 12 months. A non-inferiority test was done to assess the safety and efficacy of de-escalation DAPT compared with standard treatment. The hazard ratio (HR) for de-escalation versus active control group in a stratified Cox proportional hazards model was assessed for non-inferiority by means of an HR margin of 1·34, which equates to an absolute difference of 3·0% in the intention-to-treat population and, if significant, a superiority test was done subsequently. To ensure statistical robustness, additional analyses were also done in the per-protocol population. This trial is registered at ClinicalTrials.gov, NCT02018055.
From Feb 26, 2014, to Dec 31, 2018, from 2901 patients screened, 2697 patients were randomly assigned: 1349 patients to de-escalation and 1348 to active control groups. At 12 months, the primary endpoints occurred in 59 (4·6%) in the de-escalation group and 104 (8·2%) patients in the active control group (pnon-inferiority<0·001; HR 0·55 95% CI 0·40–0·76, psuperiority=0·0001). There was no significant difference in composite of cardiovascular death, myocardial infarction, or stroke between de-escalation (2·1%) and the active control group (3·1%; HR 0·69; 95% CI 0·42–1·14, p=0·15). Composite of BARC 2, 3, or 5 bleeding occurred less frequently in the de-escalation group (3·0% vs 5·6%, HR 0·52; 95% CI 0·35–0·77, p=0·0012).
In stabilised patients with acute myocardial infarction after index PCI, a uniform unguided de-escalation strategy significantly reduced the risk of net clinical events up to 12 months, mainly by reducing the bleeding events.
ChongKunDang Pharm, Medtronic, Abbott, and Boston Scientific.
Major concerns about donor safety cause controversy and limit the use of living donor liver transplantation to overcome organ shortages. The Korean Organ Transplantation Registry established a ...nationwide organ transplantation registration system in 2014. We reviewed the prospectively collected data of all 832 living liver donors who underwent procedures between April 2014 and December 2015. We allocated the donors to a left lobe group (n = 59) and a right lobe group (n = 773) and analyzed the relations between graft types and remaining liver volumes and complications (graded using the Clavien 5‐tier grading system). The median follow‐up was 19 months (range, 10‐31 months). During the study period, 553 men and 279 women donated livers, and there were no deaths after living liver donation. The overall, biliary, and major complication (grade ≥ III) rates were 9.3%, 1.7%, and 1.9%, respectively. The graft types and remaining liver volume were associated with significantly different overall, biliary, and major complication rates. Of the 16 patients with major complications, 9 (56.3%) involved biliary complications (2 biliary strictures 12.5% and 7 bile leakages 43.8%). Among the 832 donors, the mean aspartate transaminase, alanine aminotransferase, and total bilirubin levels were 23.9 ± 8.1 IU/L, 20.9 ± 11.3 IU/L, and 0.8 ± 0.4 mg/dL, respectively, 6 months after liver donation. In conclusion, biliary complications were the most common types of major morbidity in living liver donors. Donor hepatectomy can be performed successfully with minimal and easily controlled complications. Our study shows that prospective, nationwide cohort data provide an important means of investigating the safety in living liver donation. Liver Transplantation 23 999–1006 2017 AASLD.
Recently, the appeal of 2D black phosphorus (BP) has been rising due to its unique optical and electronic properties with a tunable band gap (≈0.3–1.5 eV). While numerous research efforts have ...recently been devoted to nano‐ and optoelectronic applications of BP, no attention has been paid to promising medical applications. In this article, the preparation of BP‐nanodots of a few nm to <20 nm with an average diameter of ≈10 nm and height of ≈8.7 nm is reported by a modified ultrasonication‐assisted solution method. Stable formation of nontoxic phosphates and phosphonates from BP crystals with exposure in water or air is observed. As for the BP‐nanodot crystals’ stability (ionization and persistence of fluorescent intensity) in aqueous solution, after 10 d, ≈80% at 1.5 mg mL−1 are degraded (i.e., ionized) in phosphate buffered saline. They showed no or little cytotoxic cell‐viability effects in vitro involving blue‐ and green‐fluorescence cell imaging. Thus, BP‐nanodots can be considered a promising agent for drug delivery or cellular tracking systems.
Black phosphorus (BP)‐nanodots are prepared using a simple ultrasonication‐assisted solution method. Compared to conventional semiconductor quantum dots, BP‐nanodots present little in vitro cytotoxicity and further blue‐ and green‐fluorescent bioimaging roles under excitations of UV and visible light, showing potential as novel drug delivery carriers in biomedical applications.
Outer membrane vesicles (OMVs) are important tools in bacterial virulence but their role in the pathogenesis of infections caused by enterohemorrhagic Escherichia coli (EHEC) O157, the leading cause ...of life-threatening hemolytic uremic syndrome, is poorly understood. Using proteomics, electron and confocal laser scanning microscopy, immunoblotting, and bioassays, we investigated OMVs secreted by EHEC O157 clinical isolates for virulence factors cargoes, interactions with pathogenetically relevant human cells, and mechanisms of cell injury. We demonstrate that O157 OMVs carry a cocktail of key virulence factors of EHEC O157 including Shiga toxin 2a (Stx2a), cytolethal distending toxin V (CdtV), EHEC hemolysin, and flagellin. The toxins are internalized by cells via dynamin-dependent endocytosis of OMVs and differentially separate from vesicles during intracellular trafficking. Stx2a and CdtV-B, the DNase-like CdtV subunit, separate from OMVs in early endosomes. Stx2a is trafficked, in association with its receptor globotriaosylceramide within detergent-resistant membranes, to the Golgi complex and the endoplasmic reticulum from where the catalytic Stx2a A1 fragment is translocated to the cytosol. CdtV-B is, after its retrograde transport to the endoplasmic reticulum, translocated to the nucleus to reach DNA. CdtV-A and CdtV-C subunits remain OMV-associated and are sorted with OMVs to lysosomes. EHEC hemolysin separates from OMVs in lysosomes and targets mitochondria. The OMV-delivered CdtV-B causes cellular DNA damage, which activates DNA damage responses leading to G2 cell cycle arrest. The arrested cells ultimately die of apoptosis induced by Stx2a and CdtV via caspase-9 activation. By demonstrating that naturally secreted EHEC O157 OMVs carry and deliver into cells a cocktail of biologically active virulence factors, thereby causing cell death, and by performing first comprehensive analysis of intracellular trafficking of OMVs and OMV-delivered virulence factors, we provide new insights into the pathogenesis of EHEC O157 infections. Our data have implications for considering O157 OMVs as vaccine candidates.
Mesenchymal stem cell (MSC) is a promising tool for the therapy of immune disorders. However, their efficacy and mechanisms in treating allergic skin disorders are less verified. We sought to ...investigate the therapeutic efficacy of human umbilical cord blood‐derived MSCs (hUCB‐MSCs) against murine atopic dermatitis (AD) and to explore distinct mechanisms that regulate their efficacy. AD was induced in mice by the topical application of Dermatophagoides farinae. Naïve or activated‐hUCB‐MSCs were administered to mice, and clinical severity was determined. The subcutaneous administration of nucleotide‐binding oligomerization domain 2 (NOD2)‐activated hUCB‐MSCs exhibited prominent protective effects against AD, and suppressed the infiltration and degranulation of mast cells (MCs). A β‐hexosaminidase assay was performed to evaluate the effect of hUCB‐MSCs on MC degranulation. NOD2‐activated MSCs reduced the MC degranulation via NOD2‐cyclooxygenase‐2 signaling. In contrast to bone marrow‐derived MSCs, hUCB‐MSCs exerted a cell‐to‐cell contact‐independent suppressive effect on MC degranulation through the higher production of prostaglandin E2 (PGE2). Additionally, transforming growth factor (TGF)‐β1 production from hUCB‐MSCs in response to interleukin‐4 contributed to the attenuation of MC degranulation by downregulating FcεRI expression in MCs. In conclusion, the subcutaneous application of NOD2‐activated hUCB‐MSCs can efficiently ameliorate AD, and MSC‐derived PGE2 and TGF‐β1 are required for the inhibition of MC degranulation. Stem Cells 2015;33:1254–1266
Face morphology is strongly determined by genetic factors. However, only a small number of genes related to face morphology have been identified to date. Here, we performed a two-stage genome-wide ...association study (GWAS) of 85 face morphological traits in 7569 Koreans (5643 in the discovery set and 1926 in the replication set).
In this study, we analyzed 85 facial traits, including facial angles. After discovery GWAS, 128 single nucleotide polymorphisms (SNPs) showing an association of P < 5 × 10
were selected to determine the replication of the associations, and meta-analysis of discovery GWAS and the replication analysis resulted in five genome-wide significant loci. The OSR1-WDR35 rs7567283, G allele, beta (se) = -0.536 (0.096), P = 2.75 × 10
locus was associated with the facial frontal contour; the HOXD1-MTX2 rs970797, A allele, beta (se) = 0.015 (0.003), P = 3.97 × 10
and WDR27 rs3736712, C allele, beta (se) = 0.293 (0.048), P = 8.44 × 10
loci were associated with eye shape; and the SOX9 rs2193054, C allele, beta (se) (ln-transformed) = -0.007 (0.001), P = 6.17 × 10
and DHX35 rs2206437, A allele, beta (se) = -0.283 (0.047), P = 1.61 × 10
loci were associated with nose shape. WDR35 and SOX9 were related to known craniofacial malformations, i.e., cranioectodermal dysplasia 2 and campomelic dysplasia, respectively. In addition, we found three independent association signals in the SOX9 locus, and six known loci for nose size and shape were replicated in this study population. Interestingly, four SNPs within these five face morphology-related loci showed discrepancies in allele frequencies among ethnic groups.
We identified five novel face morphology loci that were associated with facial frontal contour, nose shape, and eye shape. Our findings provide useful genetic information for the determination of face morphology.
Background & Aims Decreased levels or function of nucleotide-binding oligomerization domain 2 (NOD2) are associated with Crohn's disease. NOD2 regulates intestinal inflammation, and also is expressed ...by human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), to regulate their differentiation. We investigated whether NOD2 is required for the anti-inflammatory activities of MSCs in mice with colitis. Methods Colitis was induced in mice by administration of dextran sulfate sodium or trinitrobenzene sulfonic acid. Mice then were given intraperitoneal injections of NOD2-activated hUCB-MSCs; colon tissues and mesenteric lymph nodes were collected for histologic analyses. A bromodeoxyuridine assay was used to determine the ability of hUCB-MSCs to inhibit proliferation of human mononuclear cells in culture. Results Administration of hUCB-MSCs reduced the severity of colitis in mice. The anti-inflammatory effects of hUCB-MSCs were greatly increased by activation of NOD2 by its ligand, muramyl dipeptide (MDP). Administration of NOD2-activated hUCB-MSCs increased anti-inflammatory responses in colons of mice, such as production of interleukin (IL)-10 and infiltration by T regulatory cells, and reduced production of inflammatory cytokines. Proliferation of mononuclear cells was inhibited significantly by co-culture with hUCB-MSCs that had been stimulated with MDP. MDP induced prolonged production of prostaglandin (PG)E2 in hUCB-MSCs via the NOD2–RIP2 pathway, which suppressed proliferation of mononuclear cells derived from hUCB. PGE2 produced by hUCB-MSCs in response to MDP increased production of IL-10 and T regulatory cells. In mice, production of PGE2 by MSCs and subsequent production of IL-10 were required to reduce the severity of colitis. Conclusions Activation of NOD2 is required for the ability of hUCB-MSCs to reduce the severity of colitis in mice. NOD2 signaling increases the ability of these cells to suppress mononuclear cell proliferation by inducing production of PGE2.
PDF
