Impact of Priming the Infusion System on the Performance of Target-Controlled Infusion of Remifentanil.

Impact of priming the infusion system on the performance of target-controlled infusion of remifentanil.

Korean J Anesthesiol. 2013 May; 64(5): 407-13
Kim JY, Moon BK, Lee JH, Jo YY, Min SK

The start-up behavior of syringe and syringe pump is known to be one of the causes of inaccurate intravenous infusion. This study evaluated the method of priming the infusion system (PRIMING), and its impact on the target-controlled infusion (TCI) of two remifentanil diluents.PRIMING was performed using an evacuation of 2.0 ml to the atmosphere prior to TCI. Forty-eight TCI, using 50 µg/ml (Remi50) or 20 µg/ml (Remi20) of diluents, were performed targeting 4.0 ng/ml of effect-site concentration (Ceff), with PRIMING or not. The gravimetrical measurements of the delivered infusates reproduced actual Ceff. The bolus amount and time to reach 95% target were compared.Without PRIMING, Remi50 infused less bolus (43 ± 23 %) than Remi20 (19 ± 9 %) (P = 0.003), and showed more delayed increase of Ceff (11.2 ± 4.0 min) than Remi20 (7.4 ± 0.4 min) (P = 0.028). However, PRIMING significantly decreased the deficit of the bolus (2 ± 1%), as well as the delay of the increase of Ceff in Remi50 (1.2 ± 0.2 min) (both P < 0.001). In addition, with PRIMING, the start-up bolus showed minimal difference to the nominal bolus (1 and 2%), and Ceff were increased to 4.0 ± 0.1 ng/ml at the expected time of peak effect, irrespective of the diluents.Proper operation of the syringe pump used in the priming of the syringe may be helpful in reduction of the inaccuracy of TCI, particularly during the early phase of infusion, or the infusion of a more concentrated diluent. HubMed – drug

Claims-based definition of death in Japanese claims database: validity and implications.

PLoS One. 2013; 8(5): e66116
Ooba N, Setoguchi S, Ando T, Sato T, Yamaguchi T, Mochizuki M, Kubota K

For the pending National Claims Database in Japan, researchers will not have access to death information in the enrollment files. We developed and evaluated a claims-based definition of death. METHODOLOGYPRINCIPAL FINDINGS: We used healthcare claims and enrollment data between January 2005 and August 2009 for 195,193 beneficiaries aged 20 to 74 in 3 private health insurance unions. We developed claims-based definitions of death using discharge or disease status and Charlson comorbidity index (CCI). We calculated sensitivity, specificity and positive predictive values (PPVs) using the enrollment data as a gold standard in the overall population and subgroups divided by demographic and other factors. We also assessed bias and precision in two example studies where an outcome was death. The definition based on the combination of discharge/disease status and CCI provided moderate sensitivity (around 60%) and high specificity (99.99%) and high PPVs (94.8%). In most subgroups, sensitivity of the preferred definition was also around 60% but varied from 28 to 91%. In an example study comparing death rates between two anticancer drug classes, the claims-based definition provided valid and precise hazard ratios (HRs). In another example study comparing two classes of anti-depressants, the HR with the claims-based definition was biased and had lower precision than that with the gold standard definition. CONCLUSIONSSIGNIFICANCE: The claims-based definitions of death developed in this study had high specificity and PPVs while sensitivity was around 60%. The definitions will be useful in future studies when used with attention to the possible fluctuation of sensitivity in some subpopulations. HubMed – drug

The Proto-Oncogene TWIST1 Is Regulated by MicroRNAs.

PLoS One. 2013; 8(5): e66070
Nairismägi ML, Füchtbauer A, Labouriau R, Bramsen JB, Füchtbauer EM

Upregulation of the proto-oncogene Twist1 is highly correlated with acquired drug resistance and poor prognosis in human cancers. Altered expression of this multifunctional transcription factor is also associated with inherited skeletal malformations. The mammalian Twist1 3’UTRs are highly conserved and contain a number of potential regulatory elements including miRNA target sites. We analyzed the translational regulation of TWIST1 using luciferase reporter assays in a variety of cell lines. Among several miRNAs tested, miR-145a-5p, miR-151-5p and a combination of miR-145a-5p + miR-151-5p and miR-151-5p + miR-337-3p were able to significantly repress Twist1 translation. This phenomena was confirmed with both exogenous and endogenous miRNAs and was dependent on the presence of the predicted target sites in the 3’UTR. Furthermore, the repression was sensitive to LNA-modified miRNA antagonists and resulted in decreased migratory potential of murine embryonic fibroblast cells. Understanding the in vivo mechanisms of this oncogene’s regulation might open up a possibility for therapeutic interference by gene specific cancer therapies. HubMed – drug