Anti- factor IIa (FIIa) heparin assay for patients on direct factor Xa (FXa) inhibitors

BackgroundDirect factor Xa (FXa) inhibitors are increasingly prescribed for outpatients, and those transitioning to unfractionated heparin (UFH) for hospital admission are monitored via an anti- FXa assay. Because of assay interference, UFH results would often be critically elevated, confounding dosing.ObjectivesAn anti- factor IIa (FIIa) UFH assay was evaluated for clinical use.MethodsThe BIOPHEN ANTI- IIa (Aniara Diagnostica) assay and anti- FXa INNOVANCE Heparin assay (Siemens Healthcare Diagnostics Products GmbH) were compared on the Siemens BCS XP system. Samples included UFH controls and calibrators and specimens from patients transitioning from apixaban or rivaroxaban to UFH. Method comparison, linearity, recovery, precision, and interference by direct FXa inhibitors were evaluated. The effect of the BIOPHEN ANTI- IIa assay on the rate of critically high UFH results was retrospectively reviewed 4 months after implementation.ResultsAccuracy studies using 0.24 and 0.50 IU/mL UFH yielded means and standard deviations of 0.26 ± 0.01 and 0.58 ± 0.01 IU/mL, respectively. Within- run and between- run coefficients of variation were 4.6% and 15.5% for the low control, and 1.8% and 10.6% for the high control. The method comparison slope was 0.9965 (r2 = 0.9468). The linear range was 0.1 to 1.3 IU/mL. The assay measured UFH in the presence of 192 ng/mL apixaban or 158 ng/mL rivaroxaban. Introduction of the assay for clinical use reduced the monthly percentage of critically high results from 9.4% to 3.8% for admitted heparinized patients who recently discontinued apixaban or rivaroxaban.ConclusionsThe BIOPHEN ANTI- IIa assay is suitable for patients transitioning off apixaban or rivaroxaban.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156142/2/jth14806.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156142/1/jth14806_am.pd

Melioidosis Outbreak after Typhoon, Southern Taiwan

From July through September 2005, shortly after a typhoon, 40 cases of Burkholderia pseudomallei infection (melioidosis) were identified in southern Taiwan. Two genotypes that had been present in 2000 were identified by pulsed-field gel electrophoresis. Such a case cluster confirms that melioidosis is endemic to Taiwan

IRAK2, an IL1R/TLR Immune Mediator, Enhances Radiosensitivity via Modulating Caspase 8/3-Mediated Apoptosis in Oral Squamous Cell Carcinoma

Predicting and overcoming radioresistance are crucial in radiation oncology, including in managing oral squamous cell carcinoma (OSCC). First, we used RNA-sequence to compare expression profiles of parent OML1 and radioresistant OML1-R OSCC cells in order to select candidate genes responsible for radiation sensitivity. We identified IRAK2, a key immune mediator of the IL-1R/TLR signaling, as a potential target in investigating radiosensitivity. In four OSCC cell lines, we observed that intrinsically low IRAK2 expression demonstrated a radioresistant phenotype (i.e., OML1-R and SCC4), and vice versa (i.e., OML1 and SCC25). Next, we overexpressed IRAK2 in low IRAK2-expression OSCC cells and knocked it down in high IRAK2-expression cells to examine changes of irradiation response. After ionizing radiation (IR) exposure, IRAK2 overexpression enhanced the radiosensitivity of radioresistant cells and synergistically suppressed OSCC cell growth both in vitro and in vivo, and vice versa. We found that IRAK2 overexpression restored and enhanced radiosensitivity by enhancing IR-induced cell killing via caspase-8/3-dependent apoptosis. OSCC patients with high IRAK2 expression had better post-irradiation local control than those with low expression (i.e., 87.4% vs. 60.0% at five years, P = 0.055), showing that IRAK2 expression was associated with post-radiation recurrence. Multivariate analysis confirmed high IRAK2 expression as an independent predictor for local control (HR, 0.11; 95% CI, 0.016 – 0.760; P = 0.025). In conclusion, IRAK2 enhances radiosensitivity, via modulating caspase 8/3-medicated apoptosis, potentially playing double roles as a predictive biomarker and a novel therapeutic target in OSCC

Performance of Detecting IgM Antibodies against Enterovirus 71 for Early Diagnosis

Enterovirus 71 (EV71) infection is more likely to induce severe complications and mortality than other enteroviruses. Methods for detection of IgM antibody against EV71 had been established for years, however, the performance of the methods in the very early diagnosis of EV71 infection had not been fully evaluated, which is especially meaningful because of the short incubation period of EV71 infection. In this report, the performance of an IgM anti-EV71 assay was evaluated using acute sera collected from 165 EV71 infected patients, 165 patients infected with other enteroviruses, and more than 2,000 sera from healthy children or children with other infected diseases. The results showed a 90% sensitivity in 20 patients who were in their first illness day, and similar sensitivity remained till 4 days after onset. After then the sensitivity increased to 95% to 100% for more than one month. The specificity of the assay in non-HFMD children is 99.1% (95% CI: 98.6–99.4), similar as the 99.9% specificity in healthy adults. The cross-reaction rate in patients infected with other non-EV71 enteroviruses was 11.4%. In conclusion, the data here presented show that the detection of IgM anti-EV71 by ELISA affords a reliable, convenient, and prompt diagnosis of EV71 infection

A Machine Learning Approach for Identifying Novel Cell Type–Specific Transcriptional Regulators of Myogenesis

Transcriptional enhancers integrate the contributions of multiple classes of transcription factors (TFs) to orchestrate the myriad spatio-temporal gene expression programs that occur during development. A molecular understanding of enhancers with similar activities requires the identification of both their unique and their shared sequence features. To address this problem, we combined phylogenetic profiling with a DNA–based enhancer sequence classifier that analyzes the TF binding sites (TFBSs) governing the transcription of a co-expressed gene set. We first assembled a small number of enhancers that are active in Drosophila melanogaster muscle founder cells (FCs) and other mesodermal cell types. Using phylogenetic profiling, we increased the number of enhancers by incorporating orthologous but divergent sequences from other Drosophila species. Functional assays revealed that the diverged enhancer orthologs were active in largely similar patterns as their D. melanogaster counterparts, although there was extensive evolutionary shuffling of known TFBSs. We then built and trained a classifier using this enhancer set and identified additional related enhancers based on the presence or absence of known and putative TFBSs. Predicted FC enhancers were over-represented in proximity to known FC genes; and many of the TFBSs learned by the classifier were found to be critical for enhancer activity, including POU homeodomain, Myb, Ets, Forkhead, and T-box motifs. Empirical testing also revealed that the T-box TF encoded by org-1 is a previously uncharacterized regulator of muscle cell identity. Finally, we found extensive diversity in the composition of TFBSs within known FC enhancers, suggesting that motif combinatorics plays an essential role in the cellular specificity exhibited by such enhancers. In summary, machine learning combined with evolutionary sequence analysis is useful for recognizing novel TFBSs and for facilitating the identification of cognate TFs that coordinate cell type–specific developmental gene expression patterns

Insights into the dynamic structure and inhibitory mechanism of plasminogen activator inhibitor type 1

Plasminogen activator inhibitor type 1 (PAI-1) has been found to play a role in several human diseases and disease processes including metabolic syndrome, atherosclerosis, tumor angiogenesis, and renal and pulmonary fibrosis. It is a protease inhibitor of the serpin type and targets tissue-type and urokinase type plasminogen activators (t-PA and u-PA, respectively). Serpins operate using a “suicide-substrate” mechanism, in which the inhibitor is stoichiometrically consumed during protease inactivation. Specificity for target proteases is accomplished via a flexible reactive center loop (RCL) that acts as bait for the enzyme active site. Exertion of catalytic activity on the scissile bond of the RCL leads to a conformational change in the serpin in which the RCL becomes inserted into a central β-sheet, β-sheet A, translocating the acyl-linked protease a distance of 70 Å and concomitantly distorting the active site. Unable to catalyze the deacylation of the inhibitor, the protease is kinetically trapped in a covalent acyl-enzyme intermediate with the serpin. PAI-1 is unique among serpins due to its ability to rapidly undergo such a conformational change in the absence of proteolytic activity on its RCL, thereby rendering the serpin inactive in a so-called latent form. This conformational lability has made the structural study of PAI-1 challenging. Thus a stable PAI-1 variant, 14-1B, was developed, producing an X-ray crystal structure of an active PAI-1 molecule for the first time. 14-1B contains four amino acid substitutions: one in the distal hinge in close proximity to the RCL, and three in the distant α-helix F – β- strand 3A (hF/s3A) loop sub-domain. In addition to enhancing the functional stability of PAI-1, these mutations also perturb the stoichiometry and kinetics of t-PA inhibition. The aim of this study was to delineate the biochemical differences between wild-type PAI-1 (wtPAI-1) and 14-1B and to infer structural and functional details about the naturally occurring inhibitor using the structural model of the stable variant as a starting point. Using conformationally-sensitive ligands, we found that the RCL of PAI-1 exhibited more partial insertion into the β-sheet A and that β-sheet A was more accessible to the mobile RCL than was evident from the crystal structure of 14-1B. These properties suggested that PAI-1 be grouped in a novel sub-class of serpins exhibiting partially-inserted RCLs and allowed further study of its structure-function relationships in a new light. The accessibility of β-sheet A to the RCL in 14-1B is limited by mutations in the hF/s3A loop sub-domain, diminishing partial insertion of the RCL and presumably reducing the rate of full loop insertion during protease inhibition. We provide evidence strongly suggesting that these hindrances to RCL flexibility and mobility affect the mechanism by which PAI-1 inactivates t-PA at several steps, perturbing the initial non-covalent binding, slowing the formation of the acyl-enzyme complex, and compromising the stabilization of the acyl-enzyme intermediate. The work provides a more comprehensive structural model for the active conformation of PAI-1 and illuminates a new role for the hF/s3A loop sub-domain in the inhibitory mechanism of serpins

Insights Into the Dynamic Structure and Inhibitory Mechanism of Plasminogen Activator Inhibitor Type 1

147 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.The aim of this study was to delineate the biochemical differences between wild-type PAI-1 (wtPAI-1) and 14-1B and to infer structural and functional details about the naturally occurring inhibitor using the structural model of the stable variant as a starting point. Using conformationally-sensitive ligands, we found that the RCL of PAI-1 exhibited more partial insertion into the beta-sheet A and that beta-sheet A was more accessible to the mobile RCL than was evident from the crystal structure of 14-1B. These properties suggested that PAI-1 be grouped in a novel sub-class of serpins exhibiting partially-inserted RCLs and allowed further study of its structure-function relationships in a new light. The accessibility of beta-sheet A to the RCL in 14-1B is limited by mutations in the hF/s3A loop sub-domain, diminishing partial insertion of the RCL and presumably reducing the rate of full loop insertion during protease inhibition. We provide evidence strongly suggesting that these hindrances to RCL flexibility and mobility affect the mechanism by which PAI-1 inactivates t-PA at several steps, perturbing the initial non-covalent binding, slowing the formation of the acyl-enzyme complex, and compromising the stabilization of the acyl-enzyme intermediate. The work provides a more comprehensive structural model for the active conformation of PAI-1 and illuminates a new role for the hF/s3A loop sub-domain in the inhibitory mechanism of serpins.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Emphysematous Cholecystitis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140211/1/sur.2012.157.pd

Platelet refractoriness associated with platelets stored in platelet additive solution

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/173122/1/trf16941.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/173122/2/trf16941_am.pd

Chronic obstructive pulmonary disease with short-acting inhaled pharmacotherapy increases the risk of prostate cancer: A two-stage database approach.

BACKGROUND:Patients with chronic obstructive pulmonary disease (COPD) are at a higher risk of many types of cancer. However, specific investigation of the risk of prostate cancer and the influence of COPD pharmacotherapy in patients with COPD is lacking. This study investigated the risk and influence of COPD pharmacotherapy on risk of prostate cancer in patients with COPD. METHODS:This retrospective cohort study used data from Taiwan's Longitudinal Health Insurance Database 2005 (LHID2005). The study cohort comprised COPD patients who received treatment between 2004 and 2008, and who were identified from the LHID2005. The control cohort comprised patients without COPD and was matched to the study cohort by age and sex. Two-stage propensity score calibration with the National Health Interview Survey 2005 was performed to obtain the missing confounders of smoking, alcohol drinking, and body mass index in the LHID. The hazard ratio (HR) and adjusted HR were estimated. Moreover, the influence of inhaled medications and other related medication on the risk of prostate cancer was analyzed by Cox proportional hazard regression. RESULTS:The COPD cohort comprised 12,774 patients, and the control cohort comprised 38,322 patients (1:3). The incidence of prostate cancer was 633 per 100,000 person-years in the COPD cohort and 361 per 100,000 person-years in the control cohort. The propensity score calibration-adjusted HR was 1.62 (95% CI, 1.40-1.87, p < 0.001) in the COPD cohort. Further analysis revealed that the adjusted HR for the risk of prostate cancer was 1.61 (95% CI, 1.19-2.16, p = 0.002) in patients with COPD who used short-acting muscarinic antagonists (SAMAs) and 1.89 (95% CI, 1.40-2.54, p < 0.001) in patients with COPD who used short-acting beta-agonists (SABAs). COPD patients had lower risk of prostate cancer when using statin (HR = 0.63, 95% CI, 0.45-0.89, p = 0.010) or aspirin (HR = 0.55, 95% CI, 0.35-0.85, p = 0.008). CONCLUSION:Patients with COPD are at a higher risk of prostate cancer, particularly those using SAMAs or SABAs. This finding suggests that inflammation control may be an effective strategy for decreasing the risk of prostate cancer