Double deficiency of toll-like receptors 2 and 4 alters long-term neurological sequelae in mice cured of pneumococcal meningitis

Toll-like receptor (TLR) 2 and 4 signalling pathways are central to the body's defence against invading pathogens during pneumococcal meningitis. Whereas several studies support their importance in innate immunity, thereby preventing host mortality, any role in protecting neurological function during meningeal infection is ill-understood. Here we investigated both the acute immunological reaction and the long-term neurobehavioural consequences of experimental pneumococcal meningitis in mice lacking both TLR2 and TLR4. The absence of these TLRs significantly impaired survival in mice inoculated intracerebroventricularly with Streptococcus pneumoniae. During the acute phase of infection, TLR2/4-deficient mice had lower cerebrospinal fluid concentrations of interleukin-1 beta, and higher interferon-gamma, than their wild-type counterparts. After antibiotic cure, TLR2/4 double deficiency was associated with aggravation of behavioural impairment in mice, as shown by diurnal hypolocomotion throughout the adaptation phases in the Intellicage of TLR-deficient mice compared to their wild-type counterparts. While TLR2/4 double deficiency did not affect the cognitive ability of mice in a patrolling task, it aggravated the impairment of cognitive flexibility. We conclude that TLR2 and TLR4 are central to regulating the host inflammatory response in pneumococcal meningitis, which may mediate diverse compensatory mechanisms that protect the host not only against mortality but also long-term neurological complications

ECLAPTE: Effective Closure of LAParoTomy in Emergency-2023 World Society of Emergency Surgery guidelines for the closure of laparotomy in emergency settings

Laparotomy incisions provide easy and rapid access to the peritoneal cavity in case of emergency surgery. Incisional hernia (IH) is a late manifestation of the failure of abdominal wall closure and represents frequent complication of any abdominal incision: IHs can cause pain and discomfort to the patients but also clinical serious sequelae like bowel obstruction, incarceration, strangulation, and necessity of reoperation. Previous guidelines and indications in the literature consider elective settings and evidence about laparotomy closure in emergency settings is lacking. This paper aims to present the World Society of Emergency Surgery (WSES) project called ECLAPTE (Effective Closure of LAParoTomy in Emergency): the final manuscript includes guidelines on the closure of emergency laparotomy

A new strategy for enhancing imputation quality of rare variants from next-generation sequencing data via combining SNP and exome chip data

Background: Rare variants have gathered increasing attention as a possible alternative source of missing heritability. Since next generation sequencing technology is not yet cost-effective for large-scale genomic studies, a widely used alternative approach is imputation. However, the imputation approach may be limited by the low accuracy of the imputed rare variants. To improve imputation accuracy of rare variants, various approaches have been suggested, including increasing the sample size of the reference panel, using sequencing data from study-specific samples (i.e., specific populations), and using local reference panels by genotyping or sequencing a subset of study samples. While these approaches mainly utilize reference panels, imputation accuracy of rare variants can also be increased by using exome chips containing rare variants. The exome chip contains 250 K rare variants selected from the discovered variants of about 12,000 sequenced samples. If exome chip data are available for previously genotyped samples, the combined approach using a genotype panel of merged data, including exome chips and SNP chips, should increase the imputation accuracy of rare variants. Results: In this study, we describe a combined imputation which uses both exome chip and SNP chip data simultaneously as a genotype panel. The effectiveness and performance of the combined approach was demonstrated using a reference panel of 848 samples constructed using exome sequencing data from the T2D-GENES consortium and 5,349 sample genotype panels consisting of an exome chip and SNP chip. As a result, the combined approach increased imputation quality up to 11 %, and genomic coverage for rare variants up to 117.7 % (MAF < 1 %), compared to imputation using the SNP chip alone. Also, we investigated the systematic effect of reference panels on imputation quality using five reference panels and three genotype panels. The best performing approach was the combination of the study specific reference panel and the genotype panel of combined data. Conclusions: Our study demonstrates that combined datasets, including SNP chips and exome chips, enhances both the imputation quality and genomic coverage of rare variants

Pathogenesis of pneumococcal meningitis

Streptococcus pneumoniae (SP) meningitis remains a significant cause of global childhood mortality, and a potential epidemic pathogen despite improving vaccinations schemes. Neuropathology in pneumococcal meningitis (PM) is attributed to both bacterial products and the host-mediated proinflammatory response. Proinflammatory cytokine interferon-gamma (IFNγ) is associated with macrophage activation and regulating MHC Class I expression in innate immunity. IFNγ gene knockout (GKO) mice inoculated with ~5 x 103 CFU of SP/mouse were significantly protected against fatal PM, compared to C57Bl/6 WT mice, in both serotype 3 WU2 and serotype 4 TIGR4 strains. TIGR4 PM was comparatively more virulent than WU2 PM. In murine PM, IFNγ regulated induction of chemokines MCP1, CXCL9, CXCL10, the IRGM1, IRGM3 proteins and nitric oxide synthase 2 (NOS2). In WU2 PM, production of IFNγ was attributed to infiltrating Natural Killer (NK) cells, and dependent upon activation of the inflammasome complex and interleukin-18. NOS2 GKO exhibited a significantly improved survival phenotype, and reduced blood brain barrier dysfunction, compared to WT mice. Intracellular staining revealed Ly6Chi monocytes and NK cells as the source of IFNγ-dependent NOS2 in PM. Overall, this thesis addresses IFNγ production and its contribution to experimental PM pathology

Pathogenesis of pneumococcal meningitis

Streptococcus pneumoniae (SP) meningitis remains a significant cause of global childhood mortality, and a potential epidemic pathogen despite improving vaccinations schemes. Neuropathology in pneumococcal meningitis (PM) is attributed to both bacterial products and the host-mediated proinflammatory response. Proinflammatory cytokine interferon-gamma (IFNγ) is associated with macrophage activation and regulating MHC Class I expression in innate immunity. IFNγ gene knockout (GKO) mice inoculated with ~5 x 103 CFU of SP/mouse were significantly protected against fatal PM, compared to C57Bl/6 WT mice, in both serotype 3 WU2 and serotype 4 TIGR4 strains. TIGR4 PM was comparatively more virulent than WU2 PM. In murine PM, IFNγ regulated induction of chemokines MCP1, CXCL9, CXCL10, the IRGM1, IRGM3 proteins and nitric oxide synthase 2 (NOS2). In WU2 PM, production of IFNγ was attributed to infiltrating Natural Killer (NK) cells, and dependent upon activation of the inflammasome complex and interleukin-18. NOS2 GKO exhibited a significantly improved survival phenotype, and reduced blood brain barrier dysfunction, compared to WT mice. Intracellular staining revealed Ly6Chi monocytes and NK cells as the source of IFNγ-dependent NOS2 in PM. Overall, this thesis addresses IFNγ production and its contribution to experimental PM pathology

Islet Biology and Metabolism

This Special Issue, Islet Biology and Metabolism, was intended as a collection of studies highlighting the importance of the pancreatic islet—in both form and function—to our growing understanding of metabolic physiology and disease [...

Isolation and Proteomics of the Insulin Secretory Granule

Insulin, a vital hormone for glucose homeostasis is produced by pancreatic beta-cells and when secreted, stimulates the uptake and storage of glucose from the blood. In the pancreas, insulin is stored in vesicles termed insulin secretory granules (ISGs). In Type 2 diabetes (T2D), defects in insulin action results in peripheral insulin resistance and beta-cell compensation, ultimately leading to dysfunctional ISG production and secretion. ISGs are functionally dynamic and many proteins present either on the membrane or in the lumen of the ISG may modulate and affect different stages of ISG trafficking and secretion. Previously, studies have identified few ISG proteins and more recently, proteomics analyses of purified ISGs have uncovered potential novel ISG proteins. This review summarizes the proteins identified in the current ISG proteomes from rat insulinoma INS-1 and INS-1E cell lines. Here, we also discuss techniques of ISG isolation and purification, its challenges and potential future directions

Inside the Insulin Secretory Granule

The pancreatic β-cell is purpose-built for the production and secretion of insulin, the only hormone that can remove glucose from the bloodstream. Insulin is kept inside miniature membrane-bound storage compartments known as secretory granules (SGs), and these specialized organelles can readily fuse with the plasma membrane upon cellular stimulation to release insulin. Insulin is synthesized in the endoplasmic reticulum (ER) as a biologically inactive precursor, proinsulin, along with several other proteins that will also become members of the insulin SG. Their coordinated synthesis enables synchronized transit through the ER and Golgi apparatus for congregation at the trans-Golgi network, the initiating site of SG biogenesis. Here, proinsulin and its constituents enter the SG where conditions are optimized for proinsulin processing into insulin and subsequent insulin storage. A healthy β-cell is continually generating SGs to supply insulin in vast excess to what is secreted. Conversely, in type 2 diabetes (T2D), the inability of failing β-cells to secrete may be due to the limited biosynthesis of new insulin. Factors that drive the formation and maturation of SGs and thus the production of insulin are therefore critical for systemic glucose control. Here, we detail the formative hours of the insulin SG from the luminal perspective. We do this by mapping the journey of individual members of the SG as they contribute to its genesis

Effects of Ranibizumab and Aflibercept on Human Müller Cells and Photoreceptors under Stress Conditions

Anti-vascular endothelial growth factor (VEGF) therapy has revolutionized the treatment of retinal vascular diseases. However, constitutive VEGF also acts as a trophic factor on retinal nonvascular cells. We have studied the effects of aflibercept and ranibizumab on human Müller cells and photoreceptors exposed to starvation media containing various concentrations of glucose, with or without CoCl2-induced hypoxia. Cell survival was assessed by calcein-AM cell viability assays. Expression of heat shock proteins (Hsp) and redox proteins thioredoxin 1 and 2 (TRX1, TRX2) was studied by Western blots. The production of neurotrophic factors in Müller cells and interphotoreceptor retinoid-binding protein (IRBP) in photoreceptors was measured by enzymelinked immunosorbent assays. Aflibercept and ranibizumab did not affect the viability of both types of cells. Neither aflibercept nor ranibizumab affected the production of neurotrophic factors or expression of Hsp60 and Hsp90 in Müller cells. However, aflibercept but not ranibizumab affected the expression of Hsp60, Hsp9, TRX1 and TRX2 in photoreceptors. Aflibercept and ranibizumab both inhibited the production of IRBP in photoreceptors, aflibercept more so than ranibizumab. Our data indicates that the potential influence of aflibercept and ranibizumab on photoreceptors should be specifically monitored in clinical studies

Association of Pediatric ASPECTS and NIH Stroke Scale, Hemorrhagic Transformation, and 12-Month Outcome in Children With Acute Ischemic Stroke.

OBJECTIVE We aimed to determine whether a modified pediatric Alberta Stroke Program Early CT Score (modASPECTS) is associated with clinical stroke severity, hemorrhagic transformation, and 12-month functional outcomes in children with acute AIS. METHODS Children (29 days to <18 years) with acute AIS enrolled in two institutional prospective stroke registries at Children's Hospital of Philadelphia and Royal Children's Hospital Melbourne, Australia were retrospectively analyzed to determine whether modASPECTS, in which higher scores are worse, correlated with acute Pediatric NIH Stroke Scale (PedNIHSS) scores (children ≥2 years of age), was associated with hemorrhagic transformation on acute MRI, and correlated with 12-month functional outcome on the Pediatric Stroke Outcome Measure (PSOM). RESULTS 131 children were included; 91 were ≥2 years of age. Median days from stroke to MRI was 1 (interquartile range [IQR] 0-1). Median modASPECTS was 4 (IQR 3-7). ModASPECTS correlated with PedNIHSS (rho=0.40, P=0.0001). ModASPECTS was associated with hemorrhagic transformation (OR 1.13 95% CI 1.02-1.25, P=0.018). Among children with follow-up (N=128, median 12.2 months, IQR 9.5-15.4 months), worse outcomes were associated with higher modASPECTS (common OR 1.14, 95%CI 1.04-1.24, P=0.005). The association between modASPECTS and outcome persisted when we adjusted for age at stroke ictus and the presence of tumor or meningitis as stroke risk factors (common OR 1.14, 95%CI 1.03-1.25, P=0.008). CONCLUSIONS ModASPECTS correlates with PedNIHSS scores, hemorrhagic transformation, and 12-month functional outcome in children with acute AIS. Future pediatric studies should evaluate its usefulness in predicting symptomatic intracranial hemorrhage and outcome after acute revascularization therapies. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that the modified pediatric ASPECTS on MRI is associated with stroke severity (as measured by the baseline pediatric NIH Stroke Scale), hemorrhagic transformation, and 12-month outcome in children with acute supratentorial ischemic stroke