Early recognition and prevention comprise the first ring of the Chain of Survival for in-hospital cardiac arrest (IHCA). We previously developed and internally validated an emergency department (ED) ...triage tool, Emergency Department In-hospital Cardiac Arrest Score (EDICAS), for predicting ED-based IHCA. We aimed to externally validate this novel tool in another ED population. This retrospective cohort study used electronic clinical warehouse data from a tertiary medical center with approximately 130,000 ED visits per year. We retrieved data from 268,208 ED visits over a 2-year period. We selected one ED visit per person and excluded out-of-hospital cardiac arrest or children. Patient demographics and computerized triage information were retrieved, and the EDICAS was calculated to predict the ED-based IHCA. A total of 145,557 adult ED patients were included. Of them, 240 (0.16%) developed IHCA. The EDICAS showed excellent discrimination with an area under the receiver operating characteristic (AUROC) of 0.88. The AUROC of the EDICAS outperformed those of other early warning scores (0.80 for Modified Early Warning Score MEWS and 0.83 for Rapid Emergency Medicine Score REMS) in the same ED population. An EDICAS of 6 or above (i.e., high-risk patients) corresponded to a sensitivity of 33%, a specificity of 97%, and a positive likelihood ratio of 12.2. In conclusion, we externally validated a tool for predicting imminent IHCA in the ED and demonstrated its superior performance over other early warning scores. The real-world impact of the EDICAS warning system with appropriate interventions would require a future prospective study.
Phthalates are considered endocrine disruptors. Our study assessed the gender-specific effects of phthalate exposure on thyroid function in children. In total, 189 Taiwanese children were enrolled in ...the study. One-spot urine and blood samples were collected for analyzing 12 phthalate metabolites in urine and thyroid hormones. The association between urinary phthalate metabolites and serum thyroid hormones was determined using a generalized linear model with a log link function; the children were categorized into groups for analysis according to the 33rd and 66th percentiles. The data were stratified according to gender and adjusted for a priori defined covariates. In girls, a positive association existed between urinary di-2-ethylhexyl phthalate (DEHP) metabolites (mono-(2-ethylhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-hydroxyhexyl) phthalate) and free thyroxine (T4). In boys, urinary dibutyl phthalate (DBP) metabolites (mono-i-butyl phthalate and mono-n-butyl phthalate) were positively associated with free triiodothyronine (T3). After categorizing each exposure into three groups, urinary DEHP metabolites were positively associated with free T3 levels in boys. Our results suggested that DEHP is associated with free T4 in girls and that DBP is associated with free T3 in boys. Higher DEHP metabolite concentrations exerted larger effects on free T3 in boys. These results reveal the gender-specific relationships between phthalate metabolites and thyroid hormones.
Deamidation of asparagine (Asn) and isomerization of aspartic acid (Asp) residues are among the most commonly observed spontaneous post-translational modifications (PTMs) in proteins. Understanding ...and predicting a protein sequence's propensity for such PTMs can help expedite protein therapeutic discovery and development. In this study, we used proton-affinity calculations with semi-empirical quantum mechanics and microsecond long equilibrium molecular dynamics simulations to investigate mechanistic roles of structural conformation and chemical environment in dictating spontaneous degradation of Asn and Asp residues in 131 clinical-stage therapeutic antibodies. Backbone secondary structure, side-chain rotamer conformation and solvent accessibility were found to be key molecular indicators of Asp isomerization and Asn deamidation. Comparative analysis of backbone dihedral angles along with N-H proton affinity calculations provides a mechanistic explanation for the strong influence of the identity of the n + 1 residue on the rate of Asn/Asp degradation. With these findings, we propose a minimalistic physics-based classification model that can be leveraged to predict deamidation and isomerization propensity of proteins.
Protein characterization is a necessary activity during development, technical transfers, and licensure. One important aspect of protein characterization is higher order structure assessment, which ...can be accomplished in a variety of ways. Circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies provide global higher order structure and are routinely used to measure the overall structure for product characterization; however, their use as comparability tools is uncertain because of their insensitivity to local or small structure changes. We use a monoclonal antibody (mAb) to explore the usefulness of CD and FTIR compared with other indirect methods of structure characterization such as size-exclusion and ion-exchange chromatographies (SEC and IEC). A panel of degraded samples of a mAb was generated; their higher order structure evaluated using CD and FTIR and was found to be largely unchanged. However, the SEC and IEC chromatograms of certain degraded samples were found to have measurable changes. Based on these studies, we conclude that the application of CD and FTIR should be reserved for global higher order structure identification or product characterization only. The use of CD or FTIR comparability of mAbs should be carefully evaluated, as comparability can be sensitively determined using indirect methods based on chromatography.
Analytical ultracentrifugation (AUC) is a critical analytical tool supporting the development and manufacture of protein therapeutics. AUC is routinely used as an assay orthogonal to size exclusion ...chromatography for aggregate quantitation. This article distills the experimental and analysis procedures used by the authors for sedimentation velocity AUC into a series of best-practices considerations. The goal of this distillation is to help harmonize aggregate quantitation approaches across the biopharmaceutical industry. We review key considerations for sample and instrument suitability, experimental design, and data analysis best practices and conversely, highlight potential pitfalls to accurate aggregate analysis. Our goal is to provide experienced users benchmarks against which they can standardize their analyses and to provide guidance for new AUC analysts that will aid them to become proficient in this fundamental technique.
Emergency department (ED) revisits are traditionally used to measure potential lapses in emergency care. However, recent studies on in-hospital outcomes following ED revisits have begun to challenge ...this notion. We aimed to examine inpatient outcomes and resource use among patients who were hospitalized following a return visit to the ED using a national database.
This was a retrospective cohort study using the National Health Insurance Research Database in Taiwan. One-third of ED visits from 2012-2013 were randomly selected and their subsequent hospitalizations included. We analyzed the inpatient outcomes (mortality and intensive care unit ICU admission) and resource use (length of stay LOS and costs). Comparisons were made between patients who were hospitalized after a return visit to the ED and those who were hospitalized during the index ED visit.
Of the 3,019,416 index ED visits, 477,326 patients (16%) were directly admitted to the hospital. Among the 2,504,972 patients who were discharged during the index ED visit, 229,059 (9.1%) returned to the ED within three days. Of them, 37,118 (16%) were hospitalized. In multivariable analyses, the inpatient mortality rates and hospital LOS were similar between the two groups. Compared with the direct-admission group, the return-admission group had a lower ICU admission rate (adjusted odds ratio, 0.78; 95% confidence interval CI, 0.72-0.84), and lower costs (adjusted difference, -5,198 New Taiwan dollars, 95% CI, -6,224 to -4,172).
Patients who were hospitalized after a return visit to the ED had a lower ICU admission rate and lower costs, compared to those who were directly admitted. Our findings suggest that ED revisits do not necessarily translate to poor initial care and that subsequent inpatient outcomes should also be considered for better assessment.
Insights into the conformational passage of a polypeptide chain across its free energy landscape have come from the judicious combination of experimental studies and computer simulations. Even though ...some unfolded and partially folded proteins are now known to possess biological function or to be involved in aggregation phenomena associated with disease states, experimentally derived atomic-level information on these structures remains sparse as a result of conformational heterogeneity and dynamics. Here we present a technique that can provide such information. Using a 'Trp-cage' miniprotein known as TC5b (ref. 5), we report photochemically induced dynamic nuclear polarization NMR pulse-labelling experiments that involve rapid in situ protein refolding. These experiments allow dipolar cross-relaxation with hyperpolarized aromatic side chain nuclei in the unfolded state to be identified and quantified in the resulting folded-state spectrum. We find that there is residual structure due to hydrophobic collapse in the unfolded state of this small protein, with strong inter-residue contacts between side chains that are relatively distant from one another in the native state. Prior structuring, even with the formation of non-native rather than native contacts, may be a feature associated with fast folding events in proteins.
Neutralizing anti-factor VIII (FVIII) antibodies that develop in patients with hemophilia A and in murine hemophilia A models, clinically termed “inhibitors,” bind to several distinct surfaces on the ...FVIII-C2 domain. To map these epitopes at high resolution, 60 recombinant FVIII-C2 proteins were generated, each having a single surface-exposed residue mutated to alanine or a conservative substitution. The binding kinetics of these muteins to 11 monoclonal, inhibitory anti-FVIII-C2 antibodies were evaluated by surface plasmon resonance and the results compared with those obtained for wild-type FVIII-C2. Clusters of residues with significantly altered binding kinetics identified “functional” B-cell epitopes, defined as those residues contributing appreciable antigen–antibody avidity. These antibodies were previously shown to neutralize FVIII activity by interfering with proteolytic activation of FVIII by thrombin or factor Xa, or with its binding to phospholipid surfaces, von Willebrand factor, or other components of the intrinsic tenase complex. Fine mapping of epitopes by surface plasmon resonance also indicated surfaces through which FVIII interacts with proteins and phospholipids as it participates in coagulation. Mutations that significantly altered the dissociation times/half-lives identified functionally important interactions within antigen–antibody interfaces and suggested specific sequence modifications to generate novel, less antigenic FVIII proteins with possible therapeutic potential for treatment of inhibitor patients.
•Amino acid residues comprising B-cell epitopes recognized by neutralizing anti-factor VIII antibodies (inhibitors) have been identified.•Amino acids contributing significant antigen–antibody binding avidity are candidates for mutagenesis in the design of less antigenic proteins.
The Trp-cage, as the smallest miniprotein, remains the subject of numerous computational and experimental studies of protein folding dynamics and pathways. The original Trp-cage ...(NLYIQWLKDGGPSSGRPPPS, Tm = 42°C) can be significantly stabilized by mutations; melting points as high as 64°C are reported. In helical portions of the structure, each allowed replacement of Leu, Ile, Lys or Ser residues by Ala results in a 1.5 (±0.35) kJ/mol fold stabilization. No changes in structure or fluxionality of the core results upon stabilization. Contrary to the initial hypothesis, specific Pro/Trp interactions are not essential for core formation. The entropic advantage of Pro versus Ala (ΔΔSU = 11 ± 2 J/mol K) was measured at the solvent-exposed P17 site. Pro–Ala mutations at two of the three prolines (P12 and P18) that encage the indole ring result in less fold destabilization (2.3–3.4 kJ/mol). However, a P19A mutation reduces fold stability by 16 kJ/mol reflecting a favorable Y3/P19 interaction as well as Trp burial. The Y3/P19 hydrophobic staple interaction defines the folding motif as an 18-residue unit. Other stabilizing features that have been identified include a solvent-exposed Arg/Asp salt bridge (3.4–6 kJ/mol) and a buried H-bonded Ser side chain (≈10 kJ/mol).
Fatal Falls from Height in Taiwan Peng, Tzu-An; Lee, Chien-Chang; Lin, Jasper Chia-Cheng ...
Journal of forensic sciences,
July 2014, Volume:
59, Issue:
4
Journal Article
Peer reviewed
This study conducts an investigation of fatal falls from height, examines gender differences, and compares our findings with those of Western countries. We review deaths in Taiwan caused by falls ...from height that underwent forensic autopsy from 1994 to 2010. Among the examined cases, 182 were suicide, 156 were accidents, and 18 were homicides. Men who fell from greater heights had a lower probability of fatal head trauma (p = 0.045), and women exhibited a lower fatal head trauma rate when falling from heights of between 10 and 25 m in accident group (p = 0.003). There was no significant difference between cases of falling from greater and lower heights within the suicide group (p = 0.834). Psychiatric illness was only reported in 20.3% and 28.8% cases in suicide and accident groups. Only in male cases was the use of psychotropic substances higher in the suicide groups than in the accident groups (p = 0.047).
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