Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy

Contains fulltext : 149638.pdf (publisher's version ) (Closed access

Role of C-C Motif Ligand 2 and C-C Motif Receptor 2 in Murine Pulmonary Graft-versus-Host Disease after Lipopolysaccharide Inhalations

Environmental exposures are a potential trigger of chronic pulmonary graft-versus-host disease (pGVHD) after successful recovery from hematopoietic cell transplant (HCT). We hypothesized that inhalations of LPS, a prototypic environmental stimulus, trigger pGVHD via increased pulmonary recruitment of donor-derived antigen-presenting cells (APCs) through the C-C motif ligand 2 (CCL2)–C-C motif receptor 2 (CCR2) chemokine axis. B10.BR(H2k) and C57BL/6(H2b) mice underwent allogeneic (Allo) or syngeneic (Syn) HCT with wild-type (WT) C57BL/6, CCL2−/−, or CCR2−/− donors. After 4 weeks, recipient mice received daily inhaled LPS for 5 days and were killed at multiple time points. Allo mice exposed to repeated inhaled LPS developed prominent lymphocytic bronchiolitis, similar to human pGVHD. The increase in pulmonary T cells in Allo mice after LPS exposures was accompanied by increased CCL2, CCR2, and Type-1 T-helper cytokines as well as by monocytes and monocyte-derived dendritic cells (moDCs) compared with Syn and nontransplanted controls. Using CCL2−/− donors leads to a significant decrease in lung DCs but to only mildly reduced CD4 T cells. Using CCR2−/− donors significantly reduces lung DCs and moDCs but does not change T cells. CCL2 or CCR2 deficiency does not alter pGVHD pathology but increases airway hyperreactivity and IL-5 or IL-13 cytokines. Our results show that hematopoietic donor-derived CCL2 and CCR2 regulate recruitment of APCs to the Allo lung after LPS exposure. Although they do not alter pathologic pGVHD, their absence is associated with increased airway hyperreactivity and IL-5 and IL-13 cytokines. These results suggest that the APC changes that result from CCL2–CCR2 blockade may have unexpected effects on T cell differentiation and physiologic outcomes in HCT

Evaluation of hospital factors associated with hospital postoperative venous thromboembolism imaging utilisation practices.

BACKGROUND: Recent research suggests that hospital rates of postoperative venous thromboembolism (VTE) are subject to surveillance bias: the more hospitals \u27look for\u27 VTE, the more VTE they find. However, little is known about what drives variation in hospital VTE imaging rates. We conducted an observational study to examine hospital and market characteristics that were associated with hospital-level rates of postoperative VTE imaging, focusing on hospitals with particularly high rates. METHODS: For Medicare beneficiaries undergoing 11 major operations (2009-2010) at 2820 hospitals, hospital-level postoperative VTE imaging use rates were calculated. Hospital characteristics associated with hospital VTE imaging use rates were examined including case severity, size, ownership, VTE process measure adherence, accreditations, staffing, malpractice environment, and county market factors. Associations between explanatory variables and VTE imaging rates were assessed using quantile regressions at the 25th, median, 75th and 90th quantiles. RESULTS: Mean postoperative VTE imaging rates ranged from 85.26 (SD=67.38) per 1000 discharges in the lowest quartile of hospitals ranked by VTE imaging rates to 168.86 (SD=76.70) in the highest quartile. Drivers of high imaging rates at the 90th quantile were high resident-to-bed ratio (coefficient=51.35, p CONCLUSIONS: Hospital teaching status, resident-to-bed ratio, malpractice environment and local market factors drive hospital postoperative VTE imaging use, suggesting that non-clinical forces predominantly drive hospital VTE imaging practices

Hospital Characteristics Associated With Penalties in the Centers for Medicare & Medicaid Services Hospital-Acquired Condition Reduction Program

IMPORTANCE: In fiscal year (FY) 2015, the Centers for Medicare & Medicaid Services (CMS) instituted the Hospital-Acquired Condition (HAC) Reduction Program, which reduces payments to the lowest-performing hospitals. However, it is uncertain whether this program accurately measures quality and fairly penalizes hospitals. OBJECTIVE: To examine the characteristics of hospitals penalized by the HAC Reduction Program and to evaluate the association of a summary score of hospital characteristics related to quality with penalization in the HAC program. DESIGN, SETTING, AND PARTICIPANTS: Data for hospitals participating in the FY2015 HAC Reduction Program were obtained from CMS\u27 Hospital Compare and merged with the 2014 American Hospital Association Annual Survey and FY2015 Medicare Impact File. Logistic regression models were developed to examine the association between hospital characteristics and HAC program penalization. An 8-point hospital quality summary score was created using hospital characteristics related to volume, accreditations, and offering of advanced care services. The relationship between the hospital quality summary score and HAC program penalization was examined. Publicly reported process-of-care and outcome measures were examined from 4 clinical areas (surgery, acute myocardial infarction, heart failure, pneumonia), and their association with the hospital quality summary score was evaluated. EXPOSURES: Penalization in the HAC Reduction Program. MAIN OUTCOMES AND MEASURES: Hospital characteristics associated with penalization. RESULTS: Of the 3284 hospitals participating in the HAC program, 721 (22.0%) were penalized. Hospitals were more likely to be penalized if they were accredited by the Joint Commission (24.0% accredited, 14.4% not accredited; odds ratio [OR], 1.33; 95% CI, 1.04-1.70); they were major teaching hospitals (42.3%; OR, 1.58; 95% CI, 1.09-2.29) or very major teaching hospitals (62.2%; OR, 2.61; 95% CI, 1.55-4.39; vs nonteaching hospitals, 17.0%); they cared for more complex patient populations based on case mix index (quartile 4 vs quartile 1: 32.8% vs 12.1%; OR, 1.98; 95% CI, 1.44-2.71); or they were safety-net hospitals vs non-safety-net hospitals (28.3% vs 19.9%; OR, 1.36; 95% CI, 1.11-1.68). Hospitals with higher hospital quality summary scores had significantly better performance on 9 of 10 publicly reported process and outcomes measures compared with hospitals that had lower quality scores (all P ≤ .01 for trend). However, hospitals with the highest quality score of 8 were penalized significantly more frequently than hospitals with the lowest quality score of 0 (67.3% [37/55] vs 12.6% [53/422]; P \u3c .001 for trend). CONCLUSIONS AND RELEVANCE: Among hospitals participating in the HAC Reduction Program, hospitals that were penalized more frequently had more quality accreditations, offered advanced services, were major teaching institutions, and had better performance on other process and outcome measures. These paradoxical findings suggest that the approach for assessing hospital penalties in the HAC Reduction Program merits reconsideration to ensure it is achieving the intended goals

Association between hospital imaging use and venous thromboembolism events rates based on clinical data.

OBJECTIVE: The objective was to assess the presence and extent of venous thromboembolic (VTE) surveillance bias using high-quality clinical data. BACKGROUND: Hospital VTE rates are publicly reported and used in pay-for-performance programs. Prior work suggested surveillance bias: hospitals that look more for VTE with imaging studies find more VTE, thereby incorrectly seem to have worse performance. However, these results have been questioned as the risk adjustment and VTE measurement relied on administrative data. METHODS: Data (2009-2010) from 208 hospitals were available for analysis. Hospitals were divided into quartiles according to VTE imaging use rates (Medicare claims). Observed and risk-adjusted postoperative VTE event rates (regression models using American College of Surgeons National Surgical Quality Improvement Project data) were examined across VTE imaging use rate quartiles. Multivariable linear regression models were developed to assess the impact of hospital characteristics (American Hospital Association) and hospital imaging use rates on VTE event rates. RESULTS: The mean risk-adjusted VTE event rates at 30 days after surgery increased across VTE imaging use rate quartiles: 1.13% in the lowest quartile to 1.92% in the highest quartile (P \u3c 0.001). This statistically significant trend remained when examining only the inpatient period. Hospital VTE imaging use rate was the dominant driver of hospital VTE event rates (P \u3c 0.001), as no other hospital characteristics had significant associations. CONCLUSIONS: Even when examined with clinically ascertained outcomes and detailed risk adjustment, VTE rates reflect hospital imaging use and perhaps signify vigilant, high-quality care. The VTE outcome measure may not be an accurate quality indicator and should likely not be used in public reporting or pay-for-performance programs

Development of a Novel Composite Process Measure for Venous Thromboembolism Prophylaxis.

BACKGROUND: Postoperative venous thromboembolism (VTE) is important clinically, and VTE quality metrics are used in public reporting and pay-for-performance programs. However, current VTE outcome measures are not valid due to surveillance bias, and the Surgical Care Improvement Project (SCIP-VTE-2) process measure only requires prophylaxis within 24 hours of surgery. OBJECTIVES: We sought to (1) develop a novel measure of VTE prophylaxis that requires early ambulation, mechanical prophylaxis, and chemoprophylaxis throughout the hospitalization, and (2) compare hospital performance on the SCIP-VTE-2 process measure to this novel measure. RESEARCH DESIGN: A new composite measure of ambulation, sequential compression device (SCD), and chemoprophylaxis component measures was developed. The ambulation component required daily ambulation, the SCD component required documentation of continuous use, and the chemoprophylaxis component required patient-appropriate and medication-appropriate dosing and administration. Requirements could also be met with component-specific exceptions. Surgical patients at an academic center from 2012 to 2013 were assessed for SCIP-VTE-2 and composite measure adherence. RESULTS: Of 786 patients, 589 (74.9%) passed the ambulation measure, 494 (62.8%) passed the SCD measure, and 678 (86.3%) passed the chemoprophylaxis measure. A total of 268 (91.8%) SCD failures and 46 (42.6%) chemoprophylaxis failures were ordered but not administered. When comparing the 2 measures, 784 (99.7%) passed SCIP-VTE-2, whereas only 364 (46.3%) passed the composite measure (P\u3c0.001). CONCLUSIONS: This new measure incorporates the critical aspects of VTE prevention to ensure defect-free care. After additional evaluation, this composite VTE prophylaxis measure with appropriate exclusion criteria may be a better alternative to existing VTE process and outcome measures

Allogeneic Splenocyte Transfer and Lipopolysaccharide Inhalations Induce Differential T Cell Expansion and Lung Injury: A Novel Model of Pulmonary Graft-versus-Host Disease

<div><p>Background</p><p>Pulmonary GVHD (pGVHD) is an important complication of hematopoietic cell transplant (HCT) and is thought to be a consequence of the HCT conditioning regimen, allogeneic donor cells, and posttransplant lung exposures. We have previously demonstrated that serial inhaled lipopolysaccharide (LPS) exposures potentiate the development of pGVHD after murine allogeneic HCT. In the current study we hypothesized that allogeneic lymphocytes and environmental exposures alone, in the absence of a pre-conditioning regimen, would cause features of pGVHD and would lead to a different T cell expansion pattern compared to syngeneic cells.</p><p>Methods</p><p>Recipient Rag1^−/− mice received a transfer of allogeneic (Allo) or syngeneic (Syn) spleen cells. After 1 week of immune reconstitution, mice received 5 daily inhaled LPS exposures and were sacrificed 72 hours after the last LPS exposure. Lung physiology, histology, and protein levels in bronchoalveolar lavage (BAL) were assessed. Lung cells were analyzed by flow cytometry.</p><p>Results</p><p>Both Allo and Syn mice that undergo LPS exposures (AlloLPS and SynLPS) have prominent lymphocytic inflammation in their lungs, resembling pGVHD pathology, not seen in LPS-unexposed or non-transplanted controls. Compared to SynLPS, however, AlloLPS have significantly increased levels of BAL protein and enhancement of airway hyperreactivity, consistent with more severe lung injury. This injury in AlloLPS mice is associated with an increase in CD8 T cells and effector CD4 T cells, as well as a decrease in regulatory to effector CD4 T cell ratio. Additionally, cytokine analysis is consistent with a preferential Th1 differentiation and upregulation of pulmonary CCL5 and granzyme B.</p><p>Conclusions</p><p>Allogeneic lymphocyte transfer into lymphocyte-deficient mice, followed by LPS exposures, causes features of pGVHD and lung injury in the absence of a pre-conditioning HCT regimen. This lung disease associated with an expansion of allogeneic effector T cells provides a novel model to dissect mechanisms of pGVHD independent of conditioning.</p></div

Splenocyte transfer followed by inhaled LPS leads to pGVHD pathology.

<p>Rag1^−/− mice received allogeneic (Allo) or syngeneic (Syn) splenocytes or no splenocyte transfer (Rag1^−/−NT). Additional wild-type C57BL/6 (B6) mice without splenocyte transfer (B6NT) were used as controls. Allo, Syn, Rag1^−/−NT and B6NT mice underwent daily exposures to aerosolized LPS for 5 days starting 1 week after splenocyte transfer. Mice were euthanized 72 hours after the last LPS exposure. (<b>A</b>) Lung pathology assessment shows perivascular and peribronchiolar mononuclear inflammation in the AlloLPS and SynLPS mice <i>(H&E, 100X)</i>. Only minimal inflammation is seen in AlloNoLPS and SynNoLPS lungs. Rag1^−/−NT mouse lung pathology is shown for additional comparison and is similar to that of B6NT mouse lungs. After LPS, all NT mice have rare mononuclear cells visible in the perivascular and peribronchiolar structures. This is similar to pathology seen in B6NT mice. (<b>B</b>) Lung pGVHD pathology was graded in a blinded fashion using a 0–9 semi-quantitative grading schema to express the thickness of the mononuclear infiltrate around airways and around vessels as well as the overall extent of the pathology in the lung. SynLPS and AlloLPS lungs have a grade of about 8, which is significantly higher than the grade of non-LPS exposed controls where the grade is about 2.5 (AlloLPS vs. AlloNoLPS p = 0.003 and SynLPS vs. SynNoLPS p = 0.0005). As measured by this grading, LPS led to low-grade background inflammation in NT mice as shown in the graph. Data represent the average +/− SEM and **represents p<0.005. Data have been replicated in 3 independent experiments.</p

Allogeneic splenocyte transfer followed by inhaled LPS leads to an increase in pulmonary IFN-γ, granzyme B, and CCL5.

<p>Rag1^−/− mice received a transfer of allogeneic (Allo) or syngeneic (Syn) splenocytes followed by daily exposures to aerosolized LPS for 5 days starting 1 week after splenocyte transfer. Mice were euthanized 72 hours after the last LPS exposure and concentrations of proteins were measured in the BAL of AlloLPS and SynLPS mice using multiplex and ELISA assays. (<b>A</b>) IFN- γ is elevated in AlloLPS compared to SynLPS (p = ). (<b>B–D</b>) Th2 cytokines IL-4, IL-5, and IL-13 are similar between AlloLPS and SynLPS. (<b>E</b>) IL-17 is reduced in AlloLPS compared to SynLPS (p = 0.0078). (<b>F</b>) IL-10 is unchanged between AlloLPS and SynLPS. (<b>G</b>) IL-15 is elevated in the BAL of AlloLPS compared to SynLPS (p = 0.014). (<b>H</b>) Granzyme B (Gr B) is elevated in the BAL of AlloLPS mice compared to SynLPS (p = 0.029). (<b>I</b>) CCL5 is elevated in the BAL of AlloLPS mice compared to SynLPS (p = 0.0023). Data represent the average +/− SEM and * = p<0.05 and ** = p<0.005. ND = non detectable. Data have been replicated in 2 independent experiments.</p