may cause relapsing infections. We previously showed that
SH1000 surviving intracellularly to bactericidal antibiotics are persisters. Here, we used 54 non-duplicate clinical isolates to assess links ...between persistence, resistance evolution, and intracellular survival, using moxifloxacin throughout as test bactericidal antibiotic. The relative persister fraction (RPF: percentage of inoculum surviving to 100× MIC moxifloxacin in stationary phase culture for each isolate relative to ATCC 25923) was determined to categorize isolates with low (≤10) or high (>10) RPF. Evolution to resistance (moxifloxacin MIC ≥ 0.5 mg/L) was triggered by serial passages at 0.5× MIC (with daily concentration readjustments). Intracellular moxifloxacin maximal efficacy (E
) was determined by 24 h concentration-response experiments pharmacodynamic model (Hill-Langmuir) with infected THP-1 monocytes exposed to moxifloxacin (0.01 to 100× MIC) after phagocytosis. Division of intracellular survivors was followed by green fluorescence protein dilution (FACS). Most (30/36) moxifloxacin-susceptible isolates showed low RPF but all moxifloxacin-resistant (
= 18) isolates harbored high RPF. Evolution to resistance of susceptible isolates was faster for those with high vs. low RPF (with SOS response and topoisomerase-encoding genes overexpression). Intracellularly, moxifloxacin E
was decreased (less negative) for isolates with high vs. low RPF, independently from resistance. Moxifloxacin intracellular survivors were non-dividing. The data demonstrate and quantitate persisters in clinical isolates of
, and show that this phenotype accelerates resistance evolution and is associated with intracellular survival in spite of high antibiotic concentrations. Isolates with high RPF may represent a possible cause of treatment failure not directly related to resistance in patients receiving active antibiotics.
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•Gastric cancer is a leading cause of cancer related deaths.•A common feature of gastric cancers is an inflammatory microenvironment.•Cytokines are produced in gastric tumours by a ...range of cell populations.•IL-17 and IL-18 associated cytokines may represent a new therapeutic opportunity.
Chronic inflammation is recognized as a key tumor-promoting factor in a number of epithelial cancers, including gastric cancer (GC). The production of pro-inflammatory cytokines in the tumor microenvironment by both the innate and the adaptive immune response can activate signaling pathways that are associated with increased cell survival and proliferation of cancer cells. Among the cytokines that have most commonly been linked to inflammation-associated cancers, are the Th17 cell-associated cytokines IL-17A, IL-23, IL-22, and the IL-1 family members IL-1β and IL-18. However, whether their contribution to inflammation-associated cancers is universal, or specific to individual types of cancers, remains to be elucidated. This review will explore our current understanding of the known roles of these cytokines in gastritis and discuss how their therapeutic inhibition may be useful for GC.
•Optimal vancomycin dosing in critically ill patients is still uncertain.•Population pharmacokinetics and simulations were performed using 274 samples from 55 intensive care unit patients.•A 25 mg/kg ...loading dose (based on distribution volume of ca. 1 L/kg) was optimal.•A daily maintenance dose of 1–4.5 g will cover creatinine clearance varying from 10–240 mL/min.•High inter-individual variability of vancomycin population pharmacokinetics still makes therapeutic drug monitoring essential.
Despite extensive clinical use, limited data are available on optimal loading and maintenance doses of vancomycin in critically ill patients. This study aimed to develop a rational approach for optimised dosage of vancomycin given in a continuous infusion in critically ill patients.
Vancomycin pharmacokinetic (PK) data (total serum concentrations) were obtained from 55 intensive care unit (ICU) patients (Bach Mai Hospital, Hanoi, Vietnam) receiving a 20 mg/kg loading dose followed by continuous infusion stratified by creatinine clearance (CLCr). Population PK modelling and Monte Carlo simulations were performed using a nonlinear mixed-effects modelling (NONMEM) program for a target of 20–30 mg/L to optimise efficacy and minimise nephrotoxicity.
A two-compartment model with first-order elimination best fitted the PK data with central and peripheral volumes of distribution of 1.01 and 2.39 L/kg, respectively (allometric scaling to a 70 kg standard subject). The population total clearance of 3.63 L/h was only explained by renal function in the covariate and final model. The simulations showed that a 25-mg/kg loading dose infused over 90 minutes was optimal to reach the target range. The optimal maintenance dose for low renal function (CLCr < 45 mL/min) was 1000–1500 mg/day. For augmented renal clearance (CLCr > 130 mL/min) the dose should be up to 3500 mg/day or even 4500 mg/day to achieve adequate exposure. These simulated maintenance doses were larger than previously proposed for non-ICU patients.
Large loading and maintenance doses of vancomycin are generally needed in critically ill patients. Because of high interindividual variability in vancomycin PK, drug monitoring may still be necessary.
•ILC and Th17 cell populations are enriched at mucosal surfaces.•IL-17 and IL-22 are signature ILC3 and Th17 cytokines.•IL-17 and IL-22 are implicated in colorectal cancer progression.•The relative ...contribution of ILC and Th17-type cytokines to cancer needs to be defined.
Innate lymphoid cells (ILCs) contribute to the regulation of gastrointestinal (GI) homeostasis. Over the past 15 years, there has been a large effort to dissect the mechanisms required for GI homeostasis, with a major focus on different immune cell populations and the cytokines that they produce. In contrast to T-helper (Th) cells, ILCs respond rapidly to cytokines in their microenvironment in the absence of specific antigens; however, once activated both cell populations have similar effector functions. Two effector cytokines produced by both ILC3 and Th17 cell populations, Interleukin (IL)-17 and IL-22, have taken center stage for their ability to signal directly to GI epithelial cells and promote epithelial cell survival. In this review, we outline our current understanding of ILCs in the GI tract, and focus on GI cancers associated with aberrant production of IL-17 and IL-22. We highlight evidence from both mouse and patient-based analyses and discuss how tumor cells may hijack the potential evolutionary redundancy of these two cell populations.
The increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging ...fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved. In this article, we review the recent taxonomy of the basal fungi and re-evaluate the relationships among early-diverging lineages of fungal phyla. We also provide information on the ecology and distribution in
Mucoromycota
and highlight the impact of chytrids on amphibian populations. Species concepts in
Chytridiomycota
,
Aphelidiomycota
,
Rozellomycota
,
Neocallimastigomycota
are discussed in this paper. To preserve the current application of the genus
Nephridiophaga
(
Chytridiomycota
:
Nephridiophagales
)
,
a new type species,
Nephridiophaga blattellae
, is proposed.
Emerging roles for Interleukin-11 in disease Nguyen, Paul M.; Abdirahman, Suad M.; Putoczki, Tracy L.
Growth factors (Chur, Switzerland),
03/2019, Letnik:
37, Številka:
1-2
Journal Article
Recenzirano
Interleukin (IL)-11 belongs to the IL-6 family of cytokines, discovered over 30 years ago. While early studies focused on the ability of IL-11 to stimulate megakaryocytopoiesis, the importance of ...this cytokine to inflammatory disease and cancers is only just beginning to be uncovered. This review outlines recent advances in our understanding of IL-11 biology, and highlights the development of novel therapeutics with the potential for clinical targeting of signaling by this cytokine in multiple diseases.
Phenanthroline is a heterocyclic aromatic organic compound and commonly used in coordination chemistry acting as a bidentate ligand. The C4 and C7 positions of phenanthroline can often be substituted ...to change the binding capabilities of the ligand. Recently, there has been a push in the field of chemistry to create environmental-friendly chemical methodologies by utilizing catalysts and minimizing solvent. Herein, we have illustrated how, at high concentrations with minimal use of solvent, the C4 and C7 positions of phenanthroline can be tuned to develop an efficient and stereoselective catalyst for the formation of α-1,2-cis-fluorinated glycosides. By activating 2-deoxy-2-fluoro glycosyl halides with phenanthroline-based catalysts, we have been able to achieve glycosylations with high levels of α-selectivities and moderate to high yields. The catalytic system has been applied to several glycosyl halide electrophiles with a range of glycosyl nucleophilic acceptors. The proposed mechanism for this catalytic glycosylation system has been investigated by density functional theory calculations, indicating that the double SN2 displacement pathways with phenanthroline catalysts have lower barriers and ensure stereoselective formation of α-1,2-cis-2-fluoro glycosides.
Chronic inflammation of the large intestine is associated with an increased risk of developing colorectal cancer (CRC), the second most common cause of cancer-related deaths worldwide. Necroptosis ...has emerged as a form of lytic programmed cell death that, distinct from apoptosis, triggers an inflammatory response. Dysregulation of necroptosis has been linked to multiple chronic inflammatory diseases, including inflammatory bowel disease and cancer. Here, we used murine models of acute colitis, colitis-associated CRC, sporadic CRC, and spontaneous intestinal tumorigenesis to investigate the role of necroptosis in these gastrointestinal pathologies. In the Dextran Sodium Sulfate-induced acute colitis model, in some experiments, mice lacking the terminal necroptosis effector protein, MLKL, or its activator RIPK3, exhibited greater weight loss compared to wild-type mice, consistent with some earlier reports. However, the magnitude of weight loss and accompanying inflammatory pathology upon Mlkl deletion varied substantially between independent repeats. Such variation provides a possible explanation for conflicting literature reports. Furthermore, contrary to earlier reports, we observed that genetic deletion of MLKL had no impact on colon cancer development using several mouse models. Collectively, these data do not support an obligate role for necroptosis in inflammation or cancer within the gastrointestinal tract.
Interleukin (IL) 11 activates multiple intracellular signaling pathways by forming a complex with its cell surface α-receptor, IL-11Rα, and the β-subunit receptor, gp130. Dysregulated IL-11 signaling ...has been implicated in several diseases, including some cancers and fibrosis. Mutations in IL-11Rα that reduce signaling are also associated with hereditary cranial malformations. Here we present the first crystal structure of the extracellular domains of human IL-11Rα and a structure of human IL-11 that reveals previously unresolved detail. Disease-associated mutations in IL-11Rα are generally distal to putative ligand-binding sites. Molecular dynamics simulations showed that specific mutations destabilize IL-11Rα and may have indirect effects on the cytokine-binding region. We show that IL-11 and IL-11Rα form a 1:1 complex with nanomolar affinity and present a model of the complex. Our results suggest that the thermodynamic and structural mechanisms of complex formation between IL-11 and IL-11Rα differ substantially from those previously reported for similar cytokines. This work reveals key determinants of the engagement of IL-11 by IL-11Rα that may be exploited in the development of strategies to modulate formation of the IL-11–IL-11Rα complex.
Highlights • Epithelial Stat3 signaling promotes wound-healing of the gastrointestinal lining. • Aberrant gp130/Stat3 signaling supports the growth of gastric and intestinal tumors. • Interleukin-11 ...is a more potent driver of gastrointestinal tumorigenesis than IL6. • Therapeutic interference with IL11 signaling blocks gastrointestinal tumor growth.
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