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Abstract Background Proteinase-activated receptor 2 (PAR-2) is a G-protein coupled receptor associated with many inflammatory diseases, including asthma. We have shown an association between PAR-2 expression in peripheral blood monocytes and asthma severity as well as blood PAR-2 mRNA level and lung function. Since F2RL1 (the gene encoding PAR-2) polymorphisms affect PAR-2 expression, we hypothesize they may affect asthma severity. Methods We recruited 76 subjects with asthma of varying severity and collected clinical (FEV1 [% predicted], FEV1/FVC, IgE) and immunological (PAR-2 mRNA, blood eosinophils) disease parameters. We also genotyped these individuals for 3 F2RL1 SNPs (-45C/T, -149C/G, c.621C/T). Results We found that the F2RL1 SNP “C” allele of -45C/T (rs1529505) was associated with PAR-2 mRNA and blood eosinophils. F2RL1 SNP c.621C/T (rs631465) was associated with PAR-2 mRNA. The F2RL1 SNP -149C/G (rs2242991) had no association with any of the parameters studied. This study identified one F2RL1 SNP rs1529505 is associated with parameters of asthma, but not asthma severity. Conclusion Larger studies are needed to further elucidate the role of PAR-2 in the pathophysiology of asthma and the influence of genetic variation.

Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) is an immune complex–mediated hypersensitivity reaction linked as an adverse side effect to many drugs. There have been case reports of similar incidences in Nepal related to various medications. Here, we present a case of a 29-year-old lady who developed a generalized erythematous rash over her body and erosion of the oral mucous membrane. Two weeks back she gave a history of initiation of lamotrigine, olanzapine, and sertraline. Given the strong association between SJS and lamotrigine, and the usual presentation being within the first 8 weeks of exposure to susceptible medications; she was diagnosed as SJS/TEN induced by lamotrigine. On April 1, 2024, she was admitted to the ICU at KIST MCTH. All the medicines were withheld, and she was managed with corticosteroids and antihistamines. She improved significantly within 7 days. Early identification of SJS, discontinuation of triggering medicines, and prompt initiation of supportive therapy improved the prognosis.

Abstract Background Chronic obstructive pulmonary disease (COPD) affects up to 10% of Canadians. Patients with COPD may present with secondary humoral immunodeficiency as a result of chronic disease, poor nutrition or frequent courses of oral corticosteroids; decreased humoral immunity may predispose these patients to mucosal infections. We hypothesized that decreased serum immunoglobulin (Ig) levels was associated with the severity of an acute COPD exacerbations (AECOPD). Methods A prospective study to examine cardiovascular risks in patients hospitalized for AECOPD, recruited patients on the day of hospital admission and collected data on length of hospital stay at index admission, subsequent emergency department visits and hospital readmissions. Immunoglobulin levels were measured in serum collected prospectively at recruitment. Results Among the 51 patients recruited during an admission for AECOPD, 14 (27.5%) had low IgG, 1 (2.0%) low IgA and 16 (31.4%) low IgM; in total, 24 (47.1%) had at least one immunoglobulin below the normal range. Patients with low IgM had longer hospital stay during the index admission compared to patients with normal IgM levels (6.0 vs. 3.0 days, p = 0.003), but no difference in other clinical outcomes. In the whole cohort, there was a negative correlation between serum IgM levels and length of hospital stay (R = − 0.317, p = 0.024). There was no difference in clinical outcomes between subjects with normal and low IgG levels. Conclusion In patients presenting with AECOPD, low IgM is associated with longer hospital stay and may indicate a patient phenotype that would benefit from efforts to prevent respiratory infections. Trial registration statement: Retrospectively registered.

Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) is an immune complex–mediated hypersensitivity reaction linked as an adverse side effect to many drugs. There have been case reports of similar incidences in Nepal related to various medications. Here, we present a case of a 29‐year‐old lady who developed a generalized erythematous rash over her body and erosion of the oral mucous membrane. Two weeks back she gave a history of initiation of lamotrigine, olanzapine, and sertraline. Given the strong association between SJS and lamotrigine, and the usual presentation being within the first 8 weeks of exposure to susceptible medications; she was diagnosed as SJS/TEN induced by lamotrigine. On April 1, 2024, she was admitted to the ICU at KIST MCTH. All the medicines were withheld, and she was managed with corticosteroids and antihistamines. She improved significantly within 7 days. Early identification of SJS, discontinuation of triggering medicines, and prompt initiation of supportive therapy improved the prognosis. [ABSTRACT FROM AUTHOR]

Nicotinamide riboside (NR) is a NAD + precursor exhibiting beneficial effects against aging. Here the authors demonstrate that orally administered NR increases NAD + levels in a diphasic manner and that bone marrow stromal cell antigen 1 plays a crucial role for NAD + synthesis from NR.

BackgroundCRTh2 is G protein coupled receptor for prostaglandin D2 (PGD)2 expressed by immune cells that drive type 2 inflammation such as CD4+ T cells (Th2), eosinophils and group 2 innate lymphoid cells (ILC2) as well as structural cells including smooth muscle and epithelium. CRTh2-expressing cells are increased in the blood and airways of asthmatics and severe asthma is characterized by increased activity of the PGD2-CRTh2 pathway. The CRTh2 single nucleotide polymorphism (SNP) rs533116 G > A is associated with development of asthma and increased Th2 cell differentiation.ObjectiveTo examine whether CRTh2 rs533116G > A associates with asthma severity. Since severe asthma is more common in females than males, we performed a sex-stratified analysis.MethodsClinical data from asthmatics (n = 170) were obtained from clinic visits and chart review. Asthma severity was assessed according to ERS/ATS guidelines. Peripheral blood cells were characterized by flow cytometry and qRT-PCR. Genotyping was performed by TaqMan assay.ResultsOlder females (≥45 years) homozygous for minor A allele of rs533116 were more likely to have severe asthma, lower FEV1, a higher prescribed dose of inhaled corticosteroid and more type 2 inflammation than females carrying GA or GG genotypes. Comparing females and males with the AA genotype also revealed that women had more type 2 inflammation.Conclusions and significanceThe polymorphism CRTh2 rs533116 G > A associates with severe asthma and type 2 inflammation in older females. This study reveals a gene-sex-aging interaction influencing the effect of CRTh2 on asthma severity.

PAR2, a receptor activated by serine proteases, has primarily pro-inflammatory roles in the airways and may play a role in asthma pathogenesis. PAR2 exerts its effects in the lungs through activation of a variety of airway cells, but also activation of circulating immune cells. There is evidence that PAR2 expression increases in asthma and other inflammatory diseases, although the regulation of PAR2 expression is not fully understood. Here we review the available literature on the potential role of PAR2 in asthma pathogenesis and propose a model of PAR2-mediated development of allergic sensitization. We also propose, based on our previous work, that PAR2 expression on peripheral blood monocyte subsets has the potential to serve as a biomarker of asthma severity and/or control.

Abstract For the different types of throttled surge tanks used in hydropower systems, it is important to comprehensively know the throttle's head loss characteristics for exact surge analysis and transient control. Herein, a general and complete experimental setup was designed to steadily reproduce the 12 typical flow regimes occurring at the surge tank and thus conduct comprehensive experimental research on throttle head loss coefficients. Furthermore, an extended mathematical model for the surge tank was derived by inputting experimental data on the throttle's head loss coefficients to surge analysis. Through experimental research, the throttle's head loss coefficients were determined by fitting formulae relative to the different flow regimes and discharge ratios; via a detailed case analysis, the differences in the head loss characteristics for different throttle types were accurately determined. It was demonstrated that the throttle's head loss coefficient varies with discharge ratio under different flow regimes and found that the experimentally obtained flow coefficients for different throttle types are more accurate and clearly reveal the difference of throttles’ head loss characteristics. The extended mathematical model for the throttled surge tank can provide more accurate simulation results and guidance for its engineering design and layout.

Abstract Background Glucocorticosteroids (GCs) are the main treatment for asthma as they reduce type 2 cytokine expression and induce apoptosis. Asthma severity is associated with type 2 inflammation, circulating Th2 cells and higher GC requirements. Objective The aim of this study was to assess whether ex vivo production of interleukin 2 (IL‐2), a T‐cell survival factor, associated with clinical features of asthma severity, the proportion of blood Th2 cells and Th2 cell responses to GC. Methods Peripheral blood from asthma patients (n = 18) was obtained and the proportion of Th2 cells determined by flow cytometry. Peripheral blood cells were activated with mitogen (24 hours) and supernatant levels of IL‐2 and IL‐13 measured by enzyme‐linked immunosorbent assay. In vitro differentiated Th2 cells were treated with dexamethasone (DEX) and IL‐2 and assessed for apoptosis by flow cytometry (annexin V). Level of messenger RNA (mRNA) for antiapoptotic (BCL‐2) and proapoptotic (BIM) genes, IL‐13, GC receptor (GR) and FKBP5 were determined by quantitative real‐time polymerase chain reaction. GR binding was assessed by chromatin immunoprecipitation. Results IL‐2 produced by activated peripheral blood cells correlated negatively with lung function and positively with a daily dose of inhaled GC. When patients were stratified based on IL‐2 level, high IL‐2 producers made more IL‐13 and had a higher proportion of circulating Th2 cells. In vitro, increasing the level of IL‐2 in the culture media was associated with resistance to DEX‐induced apoptosis, with more BCL‐2/less BIM mRNA. Th2 cells cultured in high IL‐2 had more IL‐13, less GR mRNA, showed reduced binding of the GR to FKBP5, a known GC‐induced gene, and required higher concentrations of DEX for cytokine suppression. Conclusions and Clinical Relevance IL‐2 downregulates Th2 cell responses to GC, supporting both their survival and pro‐inflammatory capacity. These results suggest that a patient's potential to produce IL‐2 may be a determinant in asthma severity.

Abstract Background Asthma is a complex disease with variable course. Efforts to identify biomarkers to predict asthma severity, the course of disease and response to treatment have not been very successful so far. We have previous suggested that PAR-2 and CRTh2 expression on specific peripheral blood cell subtypes may be biomarkers of asthma severity. We reasoned that parameters that remain stable when asthma symptoms are controlled would be the most appropriate to evaluate for their utility to predict loss of asthma control and/or severity of the disease. Methods Nineteen stable asthmatics were recruited from the University of Alberta Asthma clinic and followed in clinic every 3 months for a total of 4 visits. Patients had spirometry and completed the ACQ questionnaire in every visit. Blood was drawn in every visit and analyzed for a number of immune parameters by flow cytometry. These parameters included PAR-2 and CRTh2 expression on monocyte subgroups and T lymphocytes respectively, as well as numbers of eosinophils, innate lymphoid type-2 cells (ILC2) and dendritic cells. Within person stability of immune and physiological parameters was calculated using the intraclass correlation (ICC) using R version 3.4.0. Results FEV1 (% predicted), FEV1/FVC ratio, ACQ5 and ACQ7 did not differ significantly over the 4 visits, as would be expected for patients with stable asthma. Peripheral blood eosinophil numbers by Kimura stain and by flow cytometry showed ICC scores of 0.44 and 0.52 respectively, indicating moderate stability. The % of ILC2 cells in peripheral blood also showed moderate stability [ICC score of 0.45 (0.14–0.67)]. The stability for all other immune parameters was poor. Conclusion Among the peripheral blood immune parameters we studied, only numbers of eosinophils and ILC2 in peripheral blood were moderately stable over a year in stable asthmatics. Further studies are required to understand the reasons for the variability of the other cell types.

G protein-coupled receptor kinase 2 (GRK2) is a ubiquitous member of the GRK family that restrains cellular activation by G protein-coupled receptor (GPCR) phosphorylation leading to receptor desensitization and internalization, but has been identified to regulate a variety of signaling molecules, among which may be associated with inflammation. In this study, we attempted to establish the regulatory role of GRK2 in the Toll-like receptor (TLR) signaling pathway for inducible nitric oxide synthase (iNOS) expression in microglial cells. When mouse MG6 cells were stimulated with the TLR4 ligands lipopolysaccharide (LPS) and paclitaxel, we found that interferon regulatory factor 1 (IRF1) protein expression and activation was upregulated, transcription of interferon-β (IFN-β) was accelerated, induction/activation of STAT1 and activation of STAT3 were promoted, and subsequently iNOS expression was upregulated. The ablation of GRK2 by small interfering RNAs (siRNAs) not only eliminated TLR4-mediated upregulation of IRF1 protein expression and nuclear translocation but also suppressed the activation of the STAT pathway, resulting in negating the iNOS upregulation. The TLR3-mediated changes in IRF1 and STAT1/3, leading to iNOS induction, were also abrogated by siRNA knockdown of GRK2. Furthermore, transfection of GRK2 siRNA blocked the exogenous IFN-β supplementation-induced increases in phosphorylation of STAT1 as well as STAT3 and abrogated the augmentation of iNOS expression in the presence of exogenous IFN-β. Taken together, our results show that GRK2 regulates the activation of IRF1 as well as the activation of the STAT pathway, leading to upregulated transcription of iNOS in activated microglial cells. Modulation of the TLR signaling pathway via GRK2 in microglia may be a novel therapeutic target for treatment of neuroinflammatory disorders.

Antimicrobial stewardship (AMS) programs can decrease non-optimal use of antibiotics in hospital settings. There are limited data on AMS programs in burn and chronic wound centers in low- and middle-income countries (LMIC). A post-prescription review and feedback (PPRF) program was implemented in three hospitals in Nepal with a focus on wound and burn care. A total of 241 baseline and 236 post-intervention patient chart data were collected from three hospitals. There was a significant decrease in utilizing days of therapy per 1000 patient days (DOT/1000 PD) of penicillin (p = 0.02), aminoglycoside (p < 0.001), and cephalosporin (p = 0.04). Increases in DOT/1000 PD at post-intervention were significant for metronidazole (p < 0.001), quinolone (p = 0.01), and other antibiotics (p < 0.001). Changes in use of antibiotics varied across hospitals, e.g., cephalosporin use decreased significantly at Kirtipur Hospital (p < 0.001) and Pokhara Academy of Health Sciences (p = 0.02), but not at Kathmandu Model Hospital (p = 0.59). An independent review conducted by infectious disease specialists at the Henry Ford Health System revealed significant changes in antibiotic prescribing practices both overall and by hospital. There was a decrease in mean number of intravenous antibiotic days between baseline (10.1 (SD 8.8)) and post-intervention (8.8 (SD 6.5)) (t = 3.56; p < 0.001), but no difference for oral antibiotics. Compared to baseline, over the 6-month post-intervention period, we found an increase in justified use of antibiotics (p < 0.001), de-escalation (p < 0.001), accurate documentation (p < 0.001), and adherence to the study antibiotic prescribing guidelines at 72 h (p < 0.001) and after diagnoses (p < 0.001). The evaluation data presented provide evidence that PPRF training and program implementation can contribute to hospital-based antibiotic stewardship for wound and burn care in Nepal.

The cumulative risk score (CRS) is a mathematical salivary diagnostic model to define an individual’s risk of having periodontitis. In order to further validate this salivary biomarker, we investigated how periodontal bacteria, lipopolysaccharide (LPS), and systemic and local host immune responses relate to CRS. Subgingival plaque, saliva, and serum samples collected from 445 individuals were used in the analyses. Plaque levels of 28 microbial species, especially those of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, and Tannerella forsythia, and serum and salivary levels of IgA and IgG against these five species were determined. Additionally, LPS activity was measured. High CRS associated strongly with all IgA/IgG antibody and LPS levels in saliva, whereas in serum the associations were not that obvious. In the final logistic regression model, the best predictors of high CRS were saliva IgA burden against the five species (OR 7.04, 95% CI 2.25–22.0), IgG burden (3.79, 1.78–8.08), LPS (2.19, 1.38–3.47), and the sum of 17 subgingival Gram-negative species (6.19, 2.10–18.3). CRS is strongly associated with microbial biomarker species of periodontitis and salivary humoral immune responses against them.

CRTh2 (encoded by PTGDR2) is a G-protein coupled receptor expressed by Th2 cells as well as eosinophils, basophils and innate lymphoid cells (ILC)2s. Activation of CRTh2, by its ligand prostaglandin (PG)D2, mediates production of type 2 cytokines (IL-4, IL-5 and IL-13), chemotaxis and inhibition of apoptosis. As such, the PGD2-CRTh2 pathway is considered important to the development and maintenance of allergic inflammation. Expression of CRTh2 is mediated by the transcription factor GATA3 during Th2 cell differentiation and within ILC2s. Other than this, relatively little is known regarding the cellular and molecular mechanisms regulating expression of CRTh2. Here, we show using primary human Th2 cells that activation (24hrs) through TCR crosslinking (αCD3/αCD28) reduced expression of both mRNA and surface levels of CRTh2 assessed by flow cytometry and qRT-PCR. This effect took more than 4 hours and expression was recovered following removal of activation. EMSA analysis revealed that GATA3 and NFAT1 can bind independently to overlapping sites within a CRTh2 promoter probe. NFAT1 over-expression resulted in loss of GATA3-mediated CRTh2 promoter activity, while inhibition of NFAT using a peptide inhibitor (VIVIT) coincided with recovery of CRTh2 expression. Collectively these data indicate that expression of CRTh2 is regulated through the competitive action of GATA3 and NFAT1. Though prolonged activation led to NFAT1-mediated downregulation, CRTh2 was re-expressed when stimulus was removed suggesting this is a dynamic mechanism and may play a role in PGD2-CRTh2 mediated allergic inflammation.