Comparison of Five Triage Tools for Identifying Mortality Risk and Injury Severity of Multiple Trauma Patients Admitted to the Emergency Department in the Daytime and Nighttime: A Retrospective Study.

Effective triage tools are indispensable for doctors to make a prompt decision for the treatment of multiple trauma patients in emergency departments (EDs). The Modified Early Warning Score (MEWS), National Early Warning Score (NEWS), standardized early warning score (SEWS), Modified Rapid Emergency Medicine Score (mREMS), and Revised Trauma Score (RTS) are five common triage tools proposed for trauma management. However, few studies have compared these tools in a multiple trauma cohort and investigated the influence of nighttime admission on the performance of these tools. This retrospective study was aimed at evaluating and comparing the performance of MEWS, NEWS, SEWS, mREMS, and RTS for identifying the mortality risk and trauma severity of patients with multiple trauma admitted to the ED during the daytime and nighttime. Retrospective data were collected from the medical records of patients with multiple trauma admitted in the daytime or nighttime to calculate scores for each triage tool. Logistic regression analysis was conducted on each triage tool for identifying in-hospital mortality and severe trauma (injury severity score > 15) in the daytime and nighttime. The performance of the tools was evaluated and compared by calculating area under the receiver operating characteristic curve (AUROC) of the retrospective logistic model of each tool. We collected data for 1,818 admissions, including 1,070 daytime and 748 nighttime admissions. A comparison of performance for identifying in-hospital mortality between daytime and nighttime yielded the following results (AUROC): MEWS (0.95 vs. 0.93, p = 0.384), NEWS (0.95 vs. 0.94, p = 0.708), SEWS (0.95 vs. 0.94, p = 0.683), mREMS (0.94 vs. 0.92, p = 0.286), and RTS (0.93 vs. 0.93, p = 0.87). Similarly, a comparison of performance for identifying trauma severity between daytime and nighttime yielded the following results (AUROC): MEWS (0.78 vs. 0.78, p = 0.95), NEWS (0.8 vs. 0.8, p = 0.885), SEWS (0.78 vs. 0.78, p = 0.818), mREMS (0.75 vs. 0.69, p = 0.019), and RTS (0.75 vs. 0.74, p = 0.619). All five scores are excellent triage tools (AUROC ≥ 0.9) for identifying in-hospital mortality for both daytime and nighttime admissions. However, they have only moderate effectiveness (AUROC < 0.9) at identifying severe trauma. The NEWS is the best triage tool for identifying severe trauma for both daytime and nighttime admissions. The MEWS, NEWS, SEWS, and RTS exhibited no significant differences in performance for identifying in-hospital mortality or severe trauma during the daytime or nighttime. However, the mREMS was better at identifying severe trauma during the daytime.

Dynamic interplay of transcriptional machinery and chromatin regulates "late" expression of the chemokine RANTES in T lymphocytes.

The chemokine RANTES (regulated upon activation normal T cell expressed and secreted) is expressed "late" (3 to 5 days) after activation in T lymphocytes. In order to understand the molecular events that accompany changes in gene expression, a detailed analysis of the interplay between transcriptional machinery and chromatin on the RANTES promoter over time was undertaken. Krüppel-like factor 13 (KLF13), a sequence-specific DNA binding transcription factor, orchestrates the induction of RANTES expression in T lymphocytes by ordered recruitment of effector molecules, including Nemo-like kinase, p300/cyclic AMP response element binding protein (CBP), p300/CBP-associated factor, and Brahma-related gene 1, that initiate sequential changes in phosphorylation and acetylation of histones and ATP-dependent chromatin remodeling near the TATA box of the RANTES promoter. These events recruit RNA polymerase II to the RANTES promoter and are responsible for late expression of RANTES in T lymphocytes. Therefore, KLF13 is a key regulator of late RANTES expression in T lymphocytes.

Retinoic acids and trichostatin A (TSA), a histone deacetylase inhibitor, induce human pyruvate dehydrogenase kinase 4 (PDK4) gene expression.

Induction of pyruvate dehydrogenase kinase 4 (PDK4) conserves glucose and substrates for gluconeogenesis and thereby helps regulate blood glucose levels during starvation. We report here that retinoic acids (RA) as well as Trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), regulate PDK4 gene expression. Two retinoic acid response elements (RAREs) to which retinoid X receptor alpha (RXRalpha) and retinoic acid receptor alpha (RARalpha) bind and activate transcription are present in the human PDK4 (hPDK4) proximal promoter. Sp1 and CCAAT box binding factor (CBF) bind to the region between two RAREs. Mutation of either the Sp1 or the CBF site significantly decreases basal expression, transactivation by RXRalpha/RARalpha/RA, and the ability of TSA to stimulate hPDK4 gene transcription. By the chromatin immunoprecipitation assay, RA and TSA increase acetylation of histones bound to the proximal promoter as well as occupancy of CBP and Sp1. Interaction of p300/CBP with E1A completely prevented hPDK4 gene activation by RXRalpha/RARalpha/RA and TSA. The p300/CBP may enhance acetylation of histones bound to the hPDK4 promoter and cooperate with Sp1 and CBF to stimulate transcription of the hPDK4 gene in response to RA and TSA.

Probing a putative active site of the catalytic subunit of pyruvate dehydrogenase phosphatase 1 (PDP1c) by site-directed mutagenesis.

The catalytic subunit of pyruvate dehydrogenase phosphatase 1 (PDP1c) is a magnesium-dependent protein phosphatase that regulates the activity of mammalian pyruvate dehydrogenase complex. Based on the sequence analysis, it was hypothesized that PDP1c is related to the mammalian magnesium-dependent protein phosphatase type 1, with Asp54, Asp347, and Asp445 contributing to the binuclear metal-binding center, and Asn49 contributing to the phosphate-binding sites. In this study, we analyzed the functional significance of these amino acid residues using a site-directed mutagenesis. It was found that substitution of each of these residues had a significant impact on PDP1c activity toward the protein substrate. The activities of Asp54, Asp347, and Asp445 mutants were decreased more than 1000-fold. The activity of Asn49 mutant was 2.5-fold lower than the activity of wild-type PDP1c. The decrease in activity of Asp54 and Asp347 came about, most likely, as a result of impaired magnesium binding. Unexpectedly, it was found that the Asp445 mutant bound Mg(2+) ions similarly to the wild-type enzyme. Accordingly, the Asp445 mutant was found to be active with the artificial substrate p-nitrophenyl phosphate (pNPP). Asp54 and Asp347 mutants did not demonstrate any appreciable activity with pNPP. Together, these observations strongly suggest that Asn49, Asp54, and Asp347 are important for the catalysis of the phosphatase reaction, contributing to the phosphate- and metal-binding centers of PDP1c. In contrast, Asp445 is not required for catalysis. The exact role of Asp445 remains to be established, but indirect evidence suggests that it might be involved in the control of interactions between PDP1c and the protein substrate pyruvate dehydrogenase.

Protein kinase B-alpha inhibits human pyruvate dehydrogenase kinase-4 gene induction by dexamethasone through inactivation of FOXO transcription factors.

Starvation and diabetes increase pyruvate dehydrogenase kinase-4 (PDK4) expression, which conserves gluconeogenic substrates by inactivating the pyruvate dehydrogenase complex. Mechanisms that regulate PDK4 gene expression, previously established to be increased by glucocorticoids and decreased by insulin, were studied. Treatment of HepG2 cells with dexamethasone increases the relative abundance of PDK4 mRNA, and insulin blocks this effect. Dexamethasone also increases human PDK4 (hPDK4) promoter activity in HepG2 cells, and insulin partially inhibits this effect. Expression of constitutively active PKB alpha abrogates dexamethasone stimulation of hPDK4 promoter activity, while coexpression of constitutively active FOXO1a or FOXO3a, which are mutated to alanine at the three phosphorylation sites for protein kinase B (PKB), disrupts the ability of PKB alpha to inhibit promoter activity. A glucocorticoid response element for glucocorticoid receptor (GR) binding and three insulin response sequences (IRSs) that bind FOXO1a and FOXO3a are identified in the hPDK4 promoter. Mutation of the IRSs reduces the ability of glucocorticoids to stimulate PDK4 transcription. Transfection studies with E1A, which binds to and inactivates p300/CBP, suggest that interactions between p300/CBP and GR as well as FOXO factors are important for glucocorticoid-stimulated hPDK4 expression. Insulin suppresses the hPDK4 induction by glucocorticoids through inactivation of the FOXO factors.

Starvation and diabetes reduce the amount of pyruvate dehydrogenase phosphatase in rat heart and kidney.

The pyruvate dehydrogenase complex (PDC) is inactivated in many tissues during starvation and diabetes to conserve three-carbon compounds for gluconeogenesis. This is achieved by an increase in the extent of PDC phosphorylation caused in part by increased pyruvate dehydrogenase kinase (PDK) activity due to increased PDK expression. This study examined whether altered pyruvate dehydrogenase phosphatase (PDP) expression also contributes to changes in the phosphorylation state of PDC during starvation and diabetes. Of the two PDP isoforms expressed in mammalian tissues, the Ca(2+)-sensitive isoform (PDP1) is highly expressed in rat heart, brain, and testis and is detectable but less abundant in rat muscle, lung, kidney, liver, and spleen. The Ca(2+)-insensitive isoform (PDP2) is abundant in rat kidney, liver, heart, and brain and is detectable in spleen and lung. Starvation and streptozotocin-induced diabetes cause decreases in PDP2 mRNA abundance, PDP2 protein amount, and PDP activity in rat heart and kidney. Refeeding and insulin treatment effectively reversed these effects of starvation and diabetes, respectively. These findings indicate that opposite changes in expression of specific PDK and PDP isoenzymes contribute to hyperphosphorylation and therefore inactivation of the PDC in heart and kidney during starvation and diabetes.

Regulation of pyruvate dehydrogenase kinase expression by peroxisome proliferator-activated receptor-alpha ligands, glucocorticoids, and insulin.

Pyruvate dehydrogenase kinase (PDK) catalyzes phosphorylation and inactivation of the pyruvate dehydrogenase complex (PDC). Two isoforms of this mitochondrial kinase (PDK2 and PDK4) are induced in a tissue-specific manner in response to starvation and diabetes. Inactivation of PDC by increased PDK activity promotes gluconeogenesis by conserving three-carbon substrates. This helps maintain glucose levels during starvation, but is detrimental in diabetes. Factors that regulate PDK2 and PDK4 expression were examined in Morris hepatoma 7800 C1 cells. The peroxisome proliferator-activated receptor-alpha (PPAR-alpha) agonist WY-14,643 and the glucocorticoid dexamethasone increased PDK4 mRNA levels. Neither compound affected the half-life of the PDK4 message, suggesting that both increase gene transcription. Fatty acids caused an increase in the PDK4 message comparable to that induced by WY-14,643. Insulin prevented and reversed the stimulatory effects of dexamethasone on PDK4 gene expression, but was less effective against the stimulatory effects of WY-14,643 and fatty acids. Insulin also decreased the abundance of the PDK2 message. The findings suggest that decreased levels of insulin and increased levels of fatty acids and glucocorticoids promote PDK4 gene expression in starvation and diabetes. The decreased level of insulin is likely responsible for the increase in PDK2 mRNA level in starvation and diabetes.

Interaction of PRP4 with Kruppel-like factor 13 regulates CCL5 transcription.

Activation of resting T lymphocytes initiates differentiation into mature effector cells over 3-7 days. The chemokine CCL5 (RANTES) and its major transcriptional regulator, Krüppel-like factor 13 (KLF13), are expressed late (3-5 days) after activation in T lymphocytes. Using yeast two-hybrid screening of a human thymus cDNA library, PRP4, a serine/threonine protein kinase, was identified as a KLF13-binding protein. Specific interaction of KLF13 and PRP4 was confirmed by reciprocal coimmunoprecipitation. PRP4 is expressed in PHA-stimulated human T lymphocytes from days 1 and 7 with a peak at day 3. Using an in vitro kinase assay, it was found that PRP4 phosphorylates KLF13. Furthermore, although phosphorylation of KLF13 by PRP4 results in lower binding affinity to the A/B site of the CCL5 promoter, coexpression of PRP4 and KLF13 increases nuclear localization of KLF13 and CCL5 transcription. Finally, knock-down of PRP4 by small interfering RNA markedly decreases CCL5 expression in T lymphocytes. Thus, PRP4-mediated phosphorylation of KLF13 plays a role in the regulation of CCL5 expression in T lymphocytes.

[Evaluation of two methods for counting residual white blood cells in thrombocytaphoresis concentrates].

To evaluate flow-cytometry and Nageotte method for counting residual WBC in thrombocytaphoresis concentrates, their accuracies were determined by dilution studies separately; the repeatability was determined by measuring the interassay coefficient of variation for 14 replicates of a sample with known leukocyte concentration. 102 samples of leukocyte-depleted thrombocytaphoresis concentrates were detected by the above mentioned two methods, and the results were compared each other. The results showed that no difference was observed between two methods over a range of leukocyte concentrations from 0.8 to 10 WBC/microl (P > 0.05). In conclusion, flow-cytometry and Nageotte methods can be used for quality control of WBC-reduced blood components.