ABSTRACT
The execution of shock following high dose E. coli lipopolysaccharide (LPS) or bacterial sepsis in mice required pro-apoptotic caspase-8 in addition to pro-pyroptotic caspase-11 and gasdermin D. Hematopoietic cells produced MyD88- and TRIF-dependent inflammatory cytokines sufficient to initiate shock without any contribution from caspase-8 or caspase-11. Both proteases had to be present to support tumor necrosis factor- and interferon-ß-dependent tissue injury first observed in the small intestine and later in spleen and thymus. Caspase-11 enhanced the activation of caspase-8 and extrinsic cell death machinery within the lower small intestine. Neither caspase-8 nor caspase-11 was individually sufficient for shock. Both caspases collaborated to amplify inflammatory signals associated with tissue damage. Therefore, combined pyroptotic and apoptotic signaling mediated endotoxemia independently of RIPK1 kinase activity and RIPK3 function. These observations bring to light the relevance of tissue compartmentalization to disease processes in vivo where cytokines act in parallel to execute diverse cell death pathways.
Subject(s)
Caspase 8/metabolism , Caspases/metabolism , Escherichia coli Infections/enzymology , Escherichia coli Infections/physiopathology , Shock, Septic/enzymology , Shock, Septic/physiopathology , Animals , Apoptosis , Apoptosis Regulatory Proteins/metabolism , Caspase 8/genetics , Caspases/genetics , Caspases, Initiator , Cells, Cultured , Female , Inflammation/metabolism , Inflammation/pathology , Interferon Regulatory Factor-3/genetics , Interferon-beta/blood , Interferon-beta/metabolism , Intestine, Small/pathology , Intracellular Signaling Peptides and Proteins , Lipopolysaccharides/toxicity , Male , Mice, Inbred C57BL , Mice, Knockout , Phosphate-Binding Proteins , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Signal Transduction , Spleen/pathology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Nanostructured semiconductors emit light from electronic states known as excitons. For organic materials, Hund's rules state that the lowest-energy exciton is a poorly emitting triplet state. For inorganic semiconductors, similar rules predict an analogue of this triplet state known as the 'dark exciton'. Because dark excitons release photons slowly, hindering emission from inorganic nanostructures, materials that disobey these rules have been sought. However, despite considerable experimental and theoretical efforts, no inorganic semiconductors have been identified in which the lowest exciton is bright. Here we show that the lowest exciton in caesium lead halide perovskites (CsPbX3, with X = Cl, Br or I) involves a highly emissive triplet state. We first use an effective-mass model and group theory to demonstrate the possibility of such a state existing, which can occur when the strong spin-orbit coupling in the conduction band of a perovskite is combined with the Rashba effect. We then apply our model to CsPbX3 nanocrystals, and measure size- and composition-dependent fluorescence at the single-nanocrystal level. The bright triplet character of the lowest exciton explains the anomalous photon-emission rates of these materials, which emit about 20 and 1,000 times faster than any other semiconductor nanocrystal at room and cryogenic temperatures, respectively. The existence of this bright triplet exciton is further confirmed by analysis of the fine structure in low-temperature fluorescence spectra. For semiconductor nanocrystals, which are already used in lighting, lasers and displays, these excitons could lead to materials with brighter emission. More generally, our results provide criteria for identifying other semiconductors that exhibit bright excitons, with potential implications for optoelectronic devices.
ABSTRACT
BACKGROUND: Complex social determinants of health may not be easily recognized by health care providers and pose a unique challenge in the vulnerable pediatric population where patients may not be able to advocate for themselves. The goal of this study was to examine the acceptability and feasibility of health care providers using an integrated brief pediatric screening tool in primary care and hospital settings. METHODS: The framework of the Child and Adolescent Needs and Strengths (CANS) and Pediatric Intermed tools was used to inform the selection of items for the 9-item Child and Adolescent Needs and Strengths-Pediatric Complexity Indicator (CANS-PCI). The tool consisted of three domains: biological, psychological, and social. Semi-structured interviews were conducted with health care providers in pediatric medical facilities in Ottawa, Canada. A low inference and iterative thematic synthesis approach was used to analyze the qualitative interview data specific to acceptability and feasibility. RESULTS: Thirteen health care providers participated in interviews. Six overarching themes were identified: acceptability, logistics, feasibility, pros/cons, risk, and privacy. Overall, participants agreed that a routine, trained provider-led pediatric tool for the screening of social determinants of health is important (n = 10, 76.9%), acceptable (n = 11; 84.6%), and feasible (n = 7, 53.8%). INTERPRETATION: Though the importance of social determinants of health are widely recognized, there are limited systematic methods of assessing, describing, and communicating amongst health care providers about the biomedical and psychosocial complexities of pediatric patients. Based on this study's findings, implementation of a brief provider-led screening tool into pediatric care practices may contribute to this gap.
Subject(s)
Feasibility Studies , Mass Screening , Social Determinants of Health , Humans , Child , Mass Screening/methods , Female , Male , Adolescent , Primary Health Care , Attitude of Health Personnel , Qualitative Research , Interviews as Topic , PediatricsABSTRACT
RIPK3 (receptor-interacting protein kinase 3) activity triggers cell death via necroptosis, whereas scaffold function supports protein binding and cytokine production. To determine if RIPK3 kinase or scaffold domains mediate pathology during Pseudomonas aeruginosa infection, control mice and those with deletion or mutation of RIPK3 and associated signaling partners were subjected to Pseudomonas pneumonia and followed for survival or killed for biologic assays. Murine immune cells were studied in vitro for Pseudomonas-induced cytokine production and cell death, and RIPK3 binding interactions were blocked with the viral inhibitor M45. Human tissue effects were assayed by infecting airway epithelial cells with Pseudomonas and measuring cytokine production after siRNA inhibition of RIPK3. Deletion of RIPK3 reduced inflammation and decreased animal mortality after Pseudomonas pneumonia. RIPK3 kinase inactivation did neither. In cell culture, RIPK3 was dispensable for cell killing by Pseudomonas and instead drove cytokine production that required the RIPK3 scaffold domain but not kinase activity. Blocking the RIP homotypic interaction motif (RHIM) with M45 reduced the inflammatory response to infection in vitro. Similarly, siRNA knockdown of RIPK3 decreased infection-triggered inflammation in human airway epithelial cells. Thus, the RIPK3 scaffold drives deleterious pulmonary inflammation and mortality in a relevant clinical model of Pseudomonas pneumonia. This process is distinct from kinase-mediated necroptosis, requiring only the RIPK3 RHIM. Inhibition of RHIM signaling is a potential strategy to reduce lung inflammation during infection.
Subject(s)
Pneumonia , Pseudomonas aeruginosa , Animals , Humans , Mice , Pseudomonas aeruginosa/metabolism , Apoptosis , Inflammation/metabolism , RNA, Small Interfering , Cytokines/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/geneticsABSTRACT
BACKGROUND: Well-differentiated and dedifferentiated liposarcomas are rare soft tissue tumors originating in adipose tissue that share genetic abnormalities but have significantly different metastatic potential. Dedifferentiated liposarcoma (DDLPS) is highly aggressive and has an overall 5-year survival rate of 30% as compared to 90% for well-differentiated liposarcoma (WDLPS). This discrepancy may be connected to their potential to form adipocytes, where WDLPS is adipogenic but DDLPS is adipogenic-impaired. Normal adipogenesis requires Zinc Finger Protein 423 (ZFP423), a transcriptional coregulator of Perixosome Proliferator Activated Receptor gamma (PPARG2) mRNA expression that defines committed preadipocytes. Expression of ZFP423 in preadipocytes is promoted by Seven-In-Absentia Homolog 2 (SIAH2)-mediated degradation of Zinc Finger Protein 521 (ZFP521). This study investigated the potential role of ZFP423, SIAH2 and ZFP521 in the adipogenic potential of WDLPS and DDLPS. METHODS: Human WDLPS and DDLPS fresh and paraffin-embedded tissues were used to assess the gene and protein expression of proadipogenic regulators. In parallel, normal adipose tissue stromal cells along with WDLPS and DDLPS cell lines were cultured, genetically modified, and induced to undergo adipogenesis in vitro. RESULTS: Impaired adipogenic potential in DDLPS was associated with reduced ZFP423 protein levels in parallel with reduced PPARG2 expression, potentially involving regulation of ZFP521. SIAH2 protein levels did not define a clear distinction related to adipogenesis in these liposarcomas. However, in primary tumor specimens, SIAH2 mRNA was consistently upregulated in DDLPS compared to WDLPS when assayed by fluorescence in situ hybridization or real-time PCR. CONCLUSIONS: These data provide novel insights into ZFP423 expression in adipogenic regulation between WDLPS and DDLPS adipocytic tumor development. The data also introduces SIAH2 mRNA levels as a possible molecular marker to distinguish between WDLPS and DDLPS.
Subject(s)
Adipogenesis/genetics , Biomarkers, Tumor/genetics , DNA-Binding Proteins , Liposarcoma/genetics , Soft Tissue Neoplasms/genetics , Zinc Fingers/genetics , Cell Line, Tumor , DNA-Binding Proteins/genetics , Humans , Liposarcoma/pathology , Nuclear Proteins/genetics , Soft Tissue Neoplasms/pathology , Ubiquitin-Protein Ligases/geneticsABSTRACT
BACKGROUND: Efforts have been concentrated on improving vaccination administration during the pretransplant evaluation period. However, concern for human leukocyte antigen (HLA) sensitization subsequent to vaccination exists. METHODS: A retrospective review of pediatric kidney transplant candidates (PKTCs) ≤18 years old who had received vaccinations between February 1, 2017 and November 30, 2019 was conducted. Emergence of de novo anti-HLA antibody (HLA-Ab) 3-4 weeks postvaccinations detected by the Luminex single antigen bead assay (SAB) was evaluated. Outcomes assessed included change in the HLA-Ab mean fluorescence intensity (MFI) ≥25% from baseline, and change in preexisting HLA-Ab MFI strength, categorized as weak: 1000-2999; moderate: 3000-9999; and strong: ≥10 000. RESULTS: Sixty vaccinations were administered to 14 patients. Forty-one potential de novo HLA-Ab were detected in five patients. After additional antibody panel testing, 5/41 potential de novo HLA-Ab were determined to be HLA specific; the remaining 36 were deemed nonspecific. The 5 de novo HLA-Ab were observed in three patients and were deemed weak antibody (Ab). Median MFI showed a significant increase for nonspecific Ab, but not de novo HLA-Ab. Median MFI values were deemed transient at 7-10 week follow-up. No HLA-donor-specific Ab developed posttransplant in the patients who developed de novo HLA-Ab. CONCLUSION: Vaccination resulted in a transient increase in non-HLA-specific Ab. The majority of responses were non-HLA specific, hypothesized to be related to denatured antigens on single antigen beads. These data suggest limited clinical impact of vaccinations on the emergence of de novo HLA-Ab.
Subject(s)
Kidney Transplantation , Adolescent , Antibody Formation , Child , Graft Rejection/prevention & control , HLA Antigens , Humans , Isoantibodies , VaccinationABSTRACT
PLA (polylactide) is a bioresorbable polymer used in implantable medical and drug delivery devices. Like other bioresorbable polymers, PLA needs to be processed carefully to avoid degradation. In this work we combine in-process temperature, pressure, and NIR spectroscopy measurements with multivariate regression methods for prediction of the mechanical strength of an extruded PLA product. The potential to use such a method as an intelligent sensor for real-time quality analysis is evaluated based on regulatory guidelines for the medical device industry. It is shown that for the predictions to be robust to processing at different times and to slight changes in the processing conditions, the fusion of both NIR and conventional process sensor data is required. Partial least squares (PLS), which is the established 'soft sensing' method in the industry, performs the best of the linear methods but demonstrates poor reliability over the full range of processing conditions. Conversely, both random forest (RF) and support vector regression (SVR) show excellent performance for all criteria when used with a prior principal component (PC) dimension reduction step. While linear methods currently dominate for soft sensing of mixture concentrations in highly conservative, regulated industries such as the medical device industry, this work indicates that nonlinear methods may outperform them in the prediction of mechanical properties from complex physicochemical sensor data. The nonlinear methods show the potential to meet industrial standards for robustness, despite the relatively small amount of training data typically available in high-value material processing.
Subject(s)
Absorbable Implants , Polymers , Least-Squares Analysis , Polyesters , Polymers/chemistry , Reproducibility of ResultsABSTRACT
BACKGROUND: Louisiana is one of the few Southern states that enacted the Medicaid expansion of the Patient Protection and Affordable Care Act (ACA). To the authors' knowledge, the issue of how this has affected the breast cancer landscape in Louisiana is unknown. The authors have postulated that ACA expansion had a positive impact for Louisiana women diagnosed with breast cancer. METHODS: Data from the Louisiana Tumor Registry regarding 14,640 women aged 20 to 64 years who resided in Louisiana and were diagnosed with American Joint Committee on Cancer stage 0 to stage IV breast cancer between 2012 and 2018 were analyzed. The study period was divided into 2 groups: 1) before ACA expansion (January 1, 2012-May 31, 2016); and 2) after ACA expansion (June 1, 2016-December 31, 2018). The chi-square test and multivariable logistic regression models were used to assess the impact of ACA expansion. A P value <.05 was considered statistically significant. RESULTS: After ACA expansion, the rate of uninsured patients decreased from 5.4% to 3.0% (P < .0001), and the rate of Medicaid recipients increased from 11.6% to 17.7% (P < .0001). The diagnosis of stage I breast cancer increased from 36.8% to 44.7% (P < .0001), whereas the diagnosis of stage III breast cancer decreased from 10.7% to 8.5% (P < .0001). The receipt of radiotherapy after breast-conserving surgery increased from 81.2% to 84.0% (P = .0035), and the receipt of radiotherapy within 90 days increased from 57.2% to 61.7% (P = .0012). After adjustment for sociodemographic and clinical variables, the models demonstrated that ACA expansion decreased the uninsured rate by 48% (odds ratio [OR], 0.52; 95% CI, 0.43-0.63), increased the diagnosis of early-stage disease (stage0 to stage II) by 27% (OR, 1.27; 95% CI, 1.15-1.41), increased receipt of radiotherapy after breast-conserving surgery by 19% (OR, 1.19; 95% CI, 1.03-1.37), and reduced the delay of receipt of radiotherapy by 16% (OR, 0.84; 95% CI, 0.74-0.95). CONCLUSIONS: ACA expansion in Louisiana reduced the uninsured rate, increased the diagnosis of early-stage disease, and increased access to treatment.
Subject(s)
Breast Neoplasms/therapy , Medicaid , Patient Protection and Affordable Care Act , Adult , Breast Neoplasms/mortality , Female , Humans , Logistic Models , Middle Aged , Social Class , United States , Young AdultABSTRACT
Inorganic lead halide perovskite nanostructures show promise as the active layers in photovoltaics, light emitting diodes, and other optoelectronic devices. They are robust in the presence of oxygen and water, and the electronic structure and dynamics of these nanostructures can be tuned through quantum confinement. Here we create aligned bundles of CsPbBr3 nanowires with widths resulting in quantum confinement of the electronic wave functions and subject them to ultrafast microscopy. We directly image rapid one-dimensional exciton diffusion along the nanowires, and we measure an exciton trap density of roughly one per nanowire. Using transient absorption microscopy, we observe a polarization-dependent splitting of the band edge exciton line, and from the polarized fluorescence of nanowires in solution, we determine that the exciton transition dipole moments are anisotropic in strength. Our observations are consistent with a model in which splitting is driven by shape anisotropy in conjunction with long-range exchange.
ABSTRACT
The bright emission observed in cesium lead halide perovskite nanocrystals (NCs) has recently been explained in terms of a bright exciton ground state [ Becker et al. Nature 2018 , 553 , 189 - 193 ], a claim that would make these materials the first known examples in which the exciton ground state is not an optically forbidden dark exciton. This unprecedented claim has been the subject of intense experimental investigation that has so far failed to detect the dark ground-state exciton. Here, we review the effective-mass/electron-hole exchange theory for the exciton fine structure in cubic and tetragonal CsPbBr3 NCs. In our calculations, the crystal field and the short-range electron-hole exchange constant were calculated using density functional theory together with hybrid functionals and spin-orbit coupling. Corrections associated with long-range exchange and surface image charges were calculated using measured bulk effective mass and dielectric parameters. As expected, within the context of the exchange model, we find an optically inactive ground exciton level. However, in this model, the level order for the optically active excitons in tetragonal CsPbBr3 NCs is opposite to what has been observed experimentally. An alternate explanation for the observed bright exciton level order in CsPbBr3 NCs is offered in terms of the Rashba effect, which supports the existence of a bright ground-state exciton in these NCs. The size dependence of the exciton fine structure calculated for perovskite NCs shows that the bright-dark level inversion caused by the Rashba effect is suppressed by the enhanced electron-hole exchange interaction in small NCs.
ABSTRACT
Due to its chemical stability, titania (TiO2) thin films increasingly have significant impact when applied as passivation layers. However, optimization of growth conditions, key to achieving essential film quality and effectiveness, is challenging in the few-nanometers thickness regime. Furthermore, the atomic-scale structure of the nominally amorphous titania coating layers, particularly when applied to nanostructured supports, is difficult to probe. In this Letter, the quality of titania layers grown on ZnO nanowires is optimized using specific strategies for processing of the nanowire cores prior to titania coating. The best approach, low-pressure O2 plasma treatment, results in significantly more-uniform titania films and a conformal coating. Characterization using X-ray absorption near edge structure (XANES) reveals the titania layer to be highly amorphous, with features in the Ti spectra significantly different from those observed for bulk TiO2 polymorphs. Analysis based on first-principles calculations suggests that the titania shell contains a substantial fraction of under-coordinated Ti4+ ions. The best match to the experimental XANES spectrum is achieved with a "glassy" TiO2 model that contains â¼50% of under-coordinated Ti4+ ions, in contrast to bulk crystalline TiO2 that only contains 6-coordinated Ti4+ ions in octahedral sites.
ABSTRACT
We present an analysis of quantum confinement of carriers and excitons, and exciton fine structure, in metal halide perovskite (MHP) nanocrystals (NCs). Starting with coupled-band k · P theory, we derive a nonparabolic effective mass model for the exciton energies in MHP NCs valid for the full size range from the strong to the weak confinement limits. We illustrate the application of the model to CsPbBr3 NCs and compare the theory against published absorption data, finding excellent agreement. We then apply the theory of electron-hole exchange, including both short- and long-range exchange interactions, to develop a model for the exciton fine structure. We develop an analytical quasicubic model for the effect of tetragonal and orthorhombic lattice distortions on the exchange-related exciton fine structure in CsPbBr3, as well as some hybrid organic MHPs of recent interest, including formamidinium lead bromide (FAPbBr3) and methylammonium lead iodide (MAPbI3). Testing the predictions of the quasicubic model using hybrid density functional theory (DFT) calculations, we find qualitative agreement in tetragonal MHPs but significant disagreement in the orthorhombic modifications. Moreover, the quasicubic model fails to correctly describe the exciton oscillator strength and with it the long-range exchange corrections in these systems. Introducing the effect of NC shape anisotropy and possible Rashba terms into the model, we illustrate the calculation of the exciton fine structure in CsPbBr3 NCs based on the results of the DFT calculations and examine the effect of Rashba terms and shape anisotropy on the calculated fine structure.
ABSTRACT
Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi-TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi-TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi-TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi-TAg mice were crossed with fabpl-Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi-TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.
Subject(s)
Apoptosis/physiology , Cell Cycle/physiology , Cell Proliferation/physiology , Enterocytes/cytology , Intestines/cytology , Sepsis/metabolism , Sepsis/pathology , Animals , Blotting, Western , Enterocytes/physiology , Female , Intestinal Mucosa/cytology , Intestinal Mucosa/metabolism , Intestinal Mucosa/physiology , Male , Mice , Mice, TransgenicABSTRACT
BACKGROUND: Dual antiplatelet therapy is a mainstay of care for percutaneous coronary intervention (PCI) patients; however, uncertainty exists in real-world practice about comparative effectiveness and safety outcomes. OBJECTIVE: To evaluate outcomes of different oral P2Y12 inhibitors in PCI patients. METHODS: We retrospectively studied patients treated between July 1, 2010, and December 31, 2013. Patients received clopidogrel, prasugrel, ticagrelor, or more than 1 antiplatelet (switch) during PCI. Outcomes were evaluated for major adverse cardiovascular events (MACE) and bleeding at 1 year. Propensity score matching with Cox proportional hazards analysis was used to determine predictors of MACE and bleeding. RESULTS: A total of 8127 patients were included: clopidogrel (n = 6872), prasugrel (n = 605), ticagrelor (n = 181), and switch (n = 469). Treatment with prasugrel was associated with the lowest risk of MACE using multivariate regression (odds ratio [OR] = 0.57; 95% CI = 0.36-0.92; P = 0.02). In the propensity score-matched analysis, only the prasugrel group was associated with a lower risk of MACE compared with the clopidogrel group. Clopidogrel was associated with the lowest risk of major bleeding using multivariate regression (OR = 0.64; 95% CI = 0.42-0.98; P = 0.042). Both ticagrelor (hazard ratio [HR] = 2.00; 95% CI = 1.11-3.59) and the switch groups (HR = 1.65; 95% CI = 1.09-2.50) were associated with a greater risk of major bleeding compared with clopidogrel. However, no differences were found in the propensity score-matched analysis. CONCLUSIONS: Dual antiplatelet therapies differed in both MACE and bleeds in a real-world setting of PCI. Prasugrel was associated with fewer MACE, whereas clopidogrel had fewer major bleeding events.
Subject(s)
Acute Coronary Syndrome/surgery , Percutaneous Coronary Intervention , Platelet Aggregation Inhibitors/therapeutic use , Purinergic P2Y Receptor Antagonists/therapeutic use , Acute Coronary Syndrome/blood , Adenosine/administration & dosage , Adenosine/adverse effects , Adenosine/analogs & derivatives , Adenosine/therapeutic use , Aged , Clopidogrel , Delivery of Health Care, Integrated , Female , Hemorrhage/chemically induced , Humans , Male , Middle Aged , Odds Ratio , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/adverse effects , Prasugrel Hydrochloride/administration & dosage , Prasugrel Hydrochloride/adverse effects , Prasugrel Hydrochloride/therapeutic use , Propensity Score , Proportional Hazards Models , Purinergic P2Y Receptor Antagonists/administration & dosage , Purinergic P2Y Receptor Antagonists/adverse effects , Receptors, Purinergic P2Y12/metabolism , Retrospective Studies , Safety , Ticagrelor , Ticlopidine/administration & dosage , Ticlopidine/adverse effects , Ticlopidine/analogs & derivatives , Ticlopidine/therapeutic useABSTRACT
OBJECTIVE: To describe and summarize the data supporting the gut as the motor driving critical illness and multiple organ dysfunction syndrome presented at the National Institute of Child Health and Human Development MODS Workshop (March 26-27, 2015). DATA SOURCES: Summary of workshop keynote presentation. STUDY SELECTION: Not applicable. DATA EXTRACTION: Presented by an expert in the field, the data assessing the role of gastrointestinal dysfunction driving critical illness were described with a focus on identifying knowledge gaps and research priorities. DATA SYNTHESIS: Summary of presentation and discussion supported and supplemented by relevant literature. CONCLUSIONS: The understanding of gut dysfunction in critical illness has evolved greatly over time, and the gut is now often considered as the "motor" of critical illness. The association of the gut with critical illness is supported by both animal models and clinical studies. Initially, the association between gut dysfunction and critical illness focused primarily on bacterial translocation into the bloodstream. However, that work has evolved to include other gut-derived products causing distant injury via other routes (e.g., lymphatics). Additionally, alterations in the gut epithelium may be associated with critical illness and influence outcomes. Gut epithelial apoptosis, intestinal hyperpermeability, and perturbations in the intestinal mucus layer have all been associated with critical illness. Finally, there is growing evidence that the intestinal microbiome plays a crucial role in mediating pathology in critical illness. Further research is needed to better understand the role of each of these mechanisms and their contribution to multiple organ dysfunction syndrome in children.
Subject(s)
Gastrointestinal Microbiome/physiology , Intestinal Mucosa/microbiology , Multiple Organ Failure/microbiology , Multiple Organ Failure/physiopathology , Bacterial Translocation , Child , Critical Illness , Humans , Intestinal Mucosa/physiopathology , PediatricsABSTRACT
BACKGROUND: Tyrosine kinase inhibitors, such as crizotinib and erlotinib, are widely used to treat non-small-cell lung cancer, but after initial response, relapse is common because of the emergence of resistance through multiple mechanisms. Here, we investigated whether a frontline combination with an HSP90 inhibitor could delay the emergence of resistance to these inhibitors in preclinical lung cancer models. METHODS: The HSP90 inhibitor, onalespib, was combined with either crizotinib or erlotinib in ALK- or EGFR-activated xenograft models respectively (H2228, HCC827). RESULTS: In both models, after initial response to the monotherapy kinase inhibitors, tumour relapse was observed. In contrast, tumour growth remained inhibited when treated with an onalespib/kinase inhibitor combination. Analysis of H2228 tumours, which had relapsed on crizotinib monotherapy, identified a number of clinically relevant crizotinib resistance mechanisms, suggesting that HSP90 inhibitor treatment was capable of suppressing multiple mechanisms of resistance. Resistant cell lines, derived from these tumours, retained sensitivity to onalespib (proliferation and signalling pathways were inhibited), indicating that, despite their resistance to crizotinib, they were still sensitive to HSP90 inhibition. CONCLUSIONS: Together, these preclinical data suggest that frontline combination with an HSP90 inhibitor may be a method for delaying the emergence of resistance to targeted therapies.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Benzamides/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Drug Resistance, Neoplasm/drug effects , Isoindoles/administration & dosage , Lung Neoplasms/drug therapy , Neoplasm Recurrence, Local/prevention & control , Protein Kinase Inhibitors/administration & dosage , Animals , Cell Line, Tumor , Crizotinib , Erlotinib Hydrochloride/administration & dosage , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Humans , Male , Mice, Inbred BALB C , Mice, SCID , Neoadjuvant Therapy/methods , Pyrazoles/administration & dosage , Pyridines/administration & dosage , Xenograft Model Antitumor AssaysABSTRACT
Traditionally, clinical recommendations for assessing and managing paediatric obesity have relied on anthropometric measures, such as body mass index (BMI), BMI percentile and/or BMI z-score, to monitor health risks and determine weight management success. However, anthropometric measures do not always accurately and reliably identify children and youth with obesity-related health risks or comorbidities. The authors propose a new clinical staging system (the Edmonton Obesity Staging System for Pediatrics, EOSS-P), adapted from the adult-oriented EOSS. The EOSS-P is used to stratify patients according to severity of obesity-related comorbidities and barriers to weight management into four graded categories (0 to 3) within four main health domains: metabolic, mechanical, mental health and social milieu (the 4Ms). The EOSS-P is based on common clinical assessments that are widely available and routinely completed by clinicians, and has the potential to provide clinical and prognostic information to help evaluate and inform the management of paediatric obesity.
D'ordinaire, les recommandations cliniques pour évaluer et prendre en charge l'obésité juvénile reposent sur des mesures anthropométriques, telles que l'indice de masse corporelle (IMC), le percentile d'IMC ou l'écart réduit de l'IMC, pour surveiller les risques sur la santé et déterminer la bonne gestion du poids. Cependant, les mesures anthropométriques ne permettent pas toujours de déterminer avec précision et fiabilité les enfants et les adolescents présentant des risques de santé ou des comorbidités liés à l'obésité. Les auteurs proposent un nouveau système clinique d'établissement du stade de l'obésité (le système d'Edmonton pour évaluer le stade de l'obésité, ou EOSS-P), adapté de l'EOSS destiné aux adultes. L'EOSS-P est utilisé pour stratifier les patients selon la gravité des comorbidités liées à l'obésité et les obstacles à la gestion du poids en quatre catégories (0 à 3) tirées de quatre grands domaines de santé : métabolique, mécanique, santé mentale et milieu social (les 4M). L'EOSS-P, qui repose sur des évaluations cliniques courantes généralisées souvent remplies par les cliniciens, peut fournir de l'information clinique et pronostique pour contribuer à évaluer et étayer la prise en charge de l'obésité juvénile.
ABSTRACT
Inhibition of heat shock 90 (Hsp90) molecular chaperones allows targeting of multiple proteins involved in tumorigenesis. We investigated the safety, recommended phase 2 dose (RP2D), and pharmacokinetic and pharmacodynamic profile of onalespib (AT13387), a potent synthetic Hsp90 inhibitor, administered on days 1, 2, 8, 9, 15, and 16 of 28 day cycles (QDx2/week) in a phase I trial. This study followed an accelerated titration design with a starting dose of 20 mg/m(2)/dose and a standard 3 + 3 dose escalation design for dose level 4 (120 mg/m(2)/dose) and above. Additional patients were enrolled at the RP2D with mandatory paired tumor biopsies to assess modulation of 210 client proteins using reverse phase protein array analysis. Thirty-one patients were treated; RP2D was established at 160 mg/m(2)/dose on the QDx2/week schedule. Common toxicities were gastrointestinal, hepatic, and hematologic. Pharmacokinetic profile was linear and plasma levels increased proportionally with dose (T½ ~8 h). No responses were observed; eight patients had stable disease for > 2 cycles with one patient remaining on study for 6 cycles. Target engagement was demonstrated by transcriptional upregulation of Hsp70 and Hsp27 in PBMCs. Statistically significant modulation of client proteins was not achieved in the 9 paired tumor biopsies evaluated; however, hierarchical clustering revealed two subgroups of patients with differential patterns of protein expression. Further combination studies are needed in order to target prospective driver oncoproteins.
Subject(s)
Benzamides/therapeutic use , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Isoindoles/therapeutic use , Neoplasms/drug therapy , Adult , Aged , Benzamides/administration & dosage , Benzamides/adverse effects , Benzamides/pharmacology , Drug Administration Schedule , Female , HSP27 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins , Humans , Isoindoles/administration & dosage , Isoindoles/adverse effects , Isoindoles/pharmacology , Male , Maximum Tolerated Dose , Middle Aged , Molecular Chaperones , Neoplasms/metabolism , RNA, Messenger/metabolismABSTRACT
BACKGROUND: Cancer is known to modulate tumor-specific immune responses by establishing a microenvironment that leads to the upregulation of T-cell inhibitory receptors, resulting in the progressive loss of function and eventual death of tumor-specific T-cells. However, the ability of cancer to impact the functionality of the immune system on a systemic level is much less well characterized. Because cancer is known to predispose patients to infectious complications including sepsis, we hypothesized that the presence of cancer alters pathogen-directed immune responses on a systemic level. MATERIALS AND METHODS: We assessed systemic T-cell coinhibitory receptor expression, cytokine production, and apoptosis in mice with established subcutaneous lung cancer tumors and in unmanipulated mice without cancer. RESULTS: Results indicated that the frequencies of programmed death-1-positive, B and T lymphocyte attenuator-positive, and 2B4(+) cells in both the CD4(+) and CD8(+) T-cell compartments were increased in mice with localized cancer relative to non-cancer controls, and the frequencies of both CD4(+) and CD8(+) T-cells expressing multiple different inhibitory receptors were increased in cancer animals relative to non-cancer controls. Additionally, 2B4(+)CD8(+) T-cells in cancer mice exhibited reduced interleukin-2 and interferon-γ, whereas B and T lymphocyte attenuator-positive CD8(+) T-cells in cancer mice exhibited reduced interleukin-2 and tumor necrosis factor. Conversely, CD4(+) T-cells in cancer animals demonstrated an increase in the frequency of annexin V(+) apoptotic cells. CONCLUSIONS: Taken together, these data suggest that the presence of cancer induces systemic T-cell exhaustion and generalized immune suppression.