Cross-validation of two prognostic trauma scores in severely injured patients

Introduction Trauma scoring systems are important tools for outcome prediction and severity adjustment that informs trauma quality assessment and research. Discrimination and precision of such systems is tested in validation studies. The German TraumaRegister DGU® (TR-DGU) and the Trauma Audit and Research Network (TARN) from the UK agreed on a cross-validation study to validate their prediction scores (RISC II and PS14, respectively). Methods Severe trauma patients with an Injury Severity Score (ISS) ≥ 9 documented in 2015 and 2016 were selected in both registries (primary admissions only). The predictive scores from each registry were applied to the selected data sets. Observed and predicted mortality were compared to assess precision; area under the receiver operating characteristic curve was used for discrimination. Hosmer–Lemeshow statistic was calculated for calibration. A subgroup analysis including patients treated in intensive care unit (ICU) was also carried out. Results From TR-DGU, 40,638 patients were included (mortality 11.7%). The RISC II predicted mortality was 11.2%, while PS14 predicted 16.9% mortality. From TARN, 64,622 patients were included (mortality 9.7%). PS14 predicted 10.6% mortality, while RISC II predicted 17.7%. Despite the identical cutoff of ISS ≥ 9, patient groups from both registries showed considerable difference in need for intensive care (88% versus 18%). Subgroup analysis of patients treated on ICU showed nearly identical values for observed and predicted mortality using RISC II. Discussion Each score performed well within its respective registry, but when applied to the other registry a decrease in performance was observed. Part of this loss of performance could be explained by different development data sets: the RISC II is mainly based on patients treated in an ICU, while the PS14 includes cases mainly cared for outside ICU with more moderate injury severity. This is according to the respective inclusion criteria of the two registries. Conclusion External validations of prediction models between registries are needed, but may show that prediction models are not fully transferable to other health-care settings

5-Aminolaevulinic Acid (ALA) for the Fluorescence Detection of Bronchial Tumors

At the moment only early detection of lung cancer offers a good prognosis for the patients. Conventional white light endoscopy is mostly insufficient for early diagnosis. Therefore we developed a system of fluorescence diagnosis using 5-aminolaevulinic acid (ALA) exogeneously applied. As precursor of the heme synthesis it is metabolized to protoporphyrin IX – a red fluorescent substance. Therefore protoporphyrin IX accumulates in tumorous and premalignant tissue, and can be directly visualized by fluorescence bronchoscopy. Excitation with blue light (380–435 nm) causes a red fluorescence, which can be detected after filtering most of the blue component with the naked eye or a camera system. After earlier work with laser systems and cold light sources we now use the system D-Light AF for the fluorescence diagnosis using ALA-induced protoporphyrin IX fluorescence

The sequential trauma score - a new instrument for the sequential mortality prediction in major trauma*

<p>Abstract</p> <p>Background</p> <p>There are several well established scores for the assessment of the prognosis of major trauma patients that all have in common that they can be calculated at the earliest during intensive care unit stay. We intended to develop a sequential trauma score (STS) that allows prognosis at several early stages based on the information that is available at a particular time.</p> <p>Study design</p> <p>In a retrospective, multicenter study using data derived from the Trauma Registry of the German Trauma Society (2002-2006), we identified the most relevant prognostic factors from the patients basic data (P), prehospital phase (A), early (B1), and late (B2) trauma room phase. Univariate and logistic regression models as well as score quality criteria and the explanatory power have been calculated.</p> <p>Results</p> <p>A total of 2,354 patients with complete data were identified. From the patients basic data (P), logistic regression showed that age was a significant predictor of survival (AUC_{model p}, area under the curve = 0.63). Logistic regression of the prehospital data (A) showed that blood pressure, pulse rate, Glasgow coma scale (GCS), and anisocoria were significant predictors (AUC_{model A}= 0.76; AUC_{model P + A}= 0.82). Logistic regression of the early trauma room phase (B1) showed that peripheral oxygen saturation, GCS, anisocoria, base excess, and thromboplastin time to be significant predictors of survival (AUC_{model B1}= 0.78; AUC_{model P +A + B1}= 0.85). Multivariate analysis of the late trauma room phase (B2) detected cardiac massage, abbreviated injury score (AIS) of the head ≥ 3, the maximum AIS, the need for transfusion or massive blood transfusion, to be the most important predictors (AUCmodel B2 = 0.84; AUCfinal model P + A + B1 + B2 = 0.90). The explanatory power - a tool for the assessment of the relative impact of each segment to mortality - is 25% for P, 7% for A, 17% for B1 and 51% for B2. A spreadsheet for the easy calculation of the sequential trauma score is available at: <url>http://www.sequential-trauma-score.com</url></p> <p>Conclusions</p> <p>This score is the first sequential, dynamic score to provide a prognosis for patients with blunt major trauma at several points in time. With every additional piece of information the precision increases. The medical team has a simple, useful tool to identify patients at high risk and to predict the prognosis of an individual patient with major trauma very early, quickly and precisely.</p

Ascaris worm in the intercostal drainage bag: inadvertent intercostal tube insertion into jejunum: a case report

Inadvertent insertion of the intercostal tube into abdomen is not rare. It can present by different ways. In the present case an Ascaris worm crept into the intercostal drainage bag to reveal the false passage of the tube

Faraday Instability in a Surface-Frozen Liquid

Faraday surface instability measurements of the critical acceleration, a_c, and wavenumber, k_c, for standing surface waves on a tetracosanol (C_24H_50) melt exhibit abrupt changes at T_s=54degC above the bulk freezing temperature. The measured variations of a_c and k_c vs. temperature and driving frequency are accounted for quantitatively by a hydrodynamic model, revealing a change from a free-slip surface flow, generic for a free liquid surface (T>T_s), to a surface-pinned, no-slip flow, characteristic of a flow near a wetted solid wall (T < T_s). The change at T_s is traced to the onset of surface freezing, where the steep velocity gradient in the surface-pinned flow significantly increases the viscous dissipation near the surface.Comment: 4 pages, 3 figures. Physical Review Letters (in press

Natural history, clinical pattern, and surgical considerations of pneumatosis intestinalis

<p>Abstract</p> <p>Objective</p> <p>Pneumatosis intestinalis has been increasingly detected in recent years with the more frequent use of computed tomography for abdominal imaging of the intestine. The underlying causes of the gas found during radiographic studies of the bowel wall can vary widely and different hypotheses regarding its pathophysiology have been postulated. Pneumatosis intestinalis often represents a benign condition and should not be considered an argument for surgery. However, it can also require life-threatening surgery in some cases, and this can be a difficult decision in some patients.</p> <p>Methods</p> <p>The spectrum of pneumatosis intestinalis is discussed here based on various computed tomographic and surgical findings in patients who presented at our University Medical Centre in 2003-2008. We have also systematically reviewed the literature to establish the current understanding of its aetiology and pathophysiology, and the possible clinical conditions associated with pneumatosis intestinalis and their management.</p> <p>Results</p> <p>Pneumatosis intestinalis is a primary radiographic finding. After its diagnosis, its specific pathogenesis should be ascertained because the appropriate therapy is related to the underlying cause of pneumatosis intestinalis, and this is sometimes difficult to define. Surgical treatment should be considered urgent in symptomatic patients presenting with an acute abdomen, signs of ischemia, or bowel obstruction. In asymptomatic patients with otherwise inconspicuous findings, the underlying disease should be treated first, rather than urgent exploratory surgery considered. Extensive and comprehensive information on the pathophysiology and clinical findings of pneumatosis intestinalis is provided here and is incorporated into a treatment algorithm.</p> <p>Conclusions</p> <p>The information presented here allows a better understanding of the radiographic diagnosis and underlying aetiology of pneumatosis intestinalis, and may facilitate the decision-making process in this context, thus providing fast and adequate therapy to particular patients.</p

TableButler – a Windows based tool for processing large data tables generated with high-throughput methods

<p>Abstract</p> <p>Background</p> <p>High-throughput "omics" based data analysis play emerging roles in life sciences and molecular diagnostics. This emphasizes the urgent need for user-friendly windows-based software interfaces that could process the diversity of large tab-delimited raw data files generated by these methods. Depending on the study, dozens to hundreds of these data tables are generated. Before the actual statistical or cluster analysis, these data tables have to be combined and merged to expression matrices (e.g., in case of gene expression analysis). Gene annotations as well as information concerning the samples analyzed may be appended, renewed or extended. Often additional data values shall be computed or certain features must be filtered out.</p> <p>Results</p> <p>In order to perform these tasks, we have developed a Microsoft Windows based application, "<b><it>TableButler</it></b>", which allows biologists or clinicians without substantial bioinformatics background to perform a plethora of data processing tasks required to analyze the large-scale data.</p> <p>Conclusion</p> <p><b><it>TableButler </it></b>is a monolithic Windows application. It is implemented to handle, join and preprocess large tab delimited ASCII data files. The intuitive user interface enables scientists (e.g. biologists, clinicians or others) to setup workflows for their specific problems by simple drag-and drop like operations.</p> <p>For more details about <b><it>TableButler</it></b>, visit <url>http://www.OncoExpress.org/software/tablebutler</url>.</p

Filtering Genes for Cluster and Network Analysis

<p>Abstract</p> <p>Background</p> <p>Prior to cluster analysis or genetic network analysis it is customary to filter, or remove genes considered to be irrelevant from the set of genes to be analyzed. Often genes whose variation across samples is less than an arbitrary threshold value are deleted. This can improve interpretability and reduce bias.</p> <p>Results</p> <p>This paper introduces modular models for representing network structure in order to study the relative effects of different filtering methods. We show that cluster analysis and principal components are strongly affected by filtering. Filtering methods intended specifically for cluster and network analysis are introduced and compared by simulating modular networks with known statistical properties. To study more realistic situations, we analyze simulated "real" data based on well-characterized E. coli and S. cerevisiae regulatory networks.</p> <p>Conclusion</p> <p>The methods introduced apply very generally, to any similarity matrix describing gene expression. One of the proposed methods, SUMCOV, performed well for all models simulated.</p

Functional significance may underlie the taxonomic utility of single amino acid substitutions in conserved proteins

We hypothesized that some amino acid substitutions in conserved proteins that are strongly fixed by critical functional roles would show lineage-specific distributions. As an example of an archetypal conserved eukaryotic protein we considered the active site of ß-tubulin. Our analysis identified one amino acid substitution—ß-tubulin F224—which was highly lineage specific. Investigation of ß-tubulin for other phylogenetically restricted amino acids identified several with apparent specificity for well-defined phylogenetic groups. Intriguingly, none showed specificity for “supergroups” other than the unikonts. To understand why, we analysed the ß-tubulin Neighbor-Net and demonstrated a fundamental division between core ß-tubulins (plant-like) and divergent ß-tubulins (animal and fungal). F224 was almost completely restricted to the core ß-tubulins, while divergent ß-tubulins possessed Y224. Thus, our specific example offers insight into the restrictions associated with the co-evolution of ß-tubulin during the radiation of eukaryotes, underlining a fundamental dichotomy between F-type, core ß-tubulins and Y-type, divergent ß-tubulins. More broadly our study provides proof of principle for the taxonomic utility of critical amino acids in the active sites of conserved proteins