No abstract

The critical reading of scientific articles is necessary for the daily practice of evidence-based medicine. Rigorous comprehension of statistical methods is essential, as reflected by the extensive use of statistics in the biomedical literature. In contrast to the customary frequentist approach, which never uses or gives the probability of a hypothesis, Bayesian theory uses probabilities for both hypotheses and data. This statistical approach is increasingly used for analyses of clinical trial data and for applied machine learning. The aim of this review is to compare general Bayesian concepts with frequentist methods to facilitate a better understanding of Bayesian theory for readers who are not familiar with this approach. The review is intended to be used in combination with a checklist we have devised for reading reports analysed by Bayesian methods. We compare and contrast the different approaches of Bayesian vs frequentist statistical methods by considering data from a clinical trial that lends itself to this comparative approach.

Treatment of human promyeloleukemic HL-60 cells with the experimental antileukemic drug ajoene induces the activation of the mitogen-activated protein kinases (MAPKs) c-Jun NH 2 -terminal kinase (JNK), p38 and extracellular signal-regulated kinases (ERK) 1/2 as well as the survival kinase Akt. JNK activation occurred in HL-60/neo, HL-60/bcl-x L , and in HL-60 cells pretreated with the pan-caspase inhibitor zVAD-fmk, indicating that JNK activation is not dependent on ajoene-induced mitochondria perturbation and subsequent caspase activation. Cells overexpressing a dominant-negative JNK showed no altered sensitivity towards ajoene suggesting that the activation of JNK is not necessary for ajoeneinduced cell death. Inhibition of p38 MAPK by SB 203580 had no influence on ajoene-mediated apoptosis. In contrast, inhibition of ERK1/2 vastly enhanced ajoeneinduced cell death. The survival kinase Akt, in contrast, did not participate in ajoene-induced death signaling as shown by the use of the phosphatidylinositol-3-kinase inhibitor wortmannin. Thus in contrast to the previous findings regarding stress-induced cell death, ajoenemediated activation of JNK and p38 has no impact on ajoene-induced apoptosis in HL-60 cells. Blockade of ERK1/2 but not Akt pathways leads to sensitization of cells against ajoene-mediated apoptosis supporting the view that inhibition of ERK1/2 is a valuable strategy to increase the sensitivity of promyeloleukemic cells towards ajoene.

No abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe present work describes the financial assurance system (bonding system), an innovative incentive mechanism being adopted by several countries in different productive areas with the objective of guaranteeing the availability of sufficient financial resources for the compliance of end-of-leasing environmental obligations. This paper provides a general outlook of the many decommissioning related issues that economically impact oil projects around the world. There are several forms of bonds available providing optimum flexibility for companies to meet all decommissioning and abandonment requirements. Bonds will provide several advantages such as:(1) ensure satisfactory regulatory compliance; (2) safeguard government and taxpayers by attaining reasonable protection from default at a minimum increase in project costs; and (3) protect the environment from potential harm resulting from failure to carryout proper decommissioning operations in a timely fashion. Based upon a discount cash flow analysis this paper suggests a decision model that estimates for each bond the option which offers the least economic impact in the project and, at same time, provides the best financial guarantee for all stakeholders involved in the process.

Preemptive strategy of antifungal drug prescriptions in highly colonized ICU patients induced an increase in C. glabrata colonization without significant shift of colonization to other Candida spp. in surgical ICU patients. However, the potential detrimental impact of fluconazole on Candida ecology in ICU and/or on Candida susceptibility to antifungal drugs should be considered, and deserves further studies.

Introduction: In the context of an increasing number of publications of trial data analysed by Bayesian methods, clinicians need support to better understand Bayesian statistical methods. The existing checklists are intended for people who already know these methods. We aimed to establish and validate a checklist that contains a group of items considered crucial in interpreting the results of a phase III RCT analysed with Bayesian methods. Methods: A team of biostatisticians created a checklist of previously reported items and additional items identified from a literature review. Using three different articles in three rounds, the items were then validated by residents in anaesthesiology with no skills in statistics. Results: Based on an initial item list, three rounds led to a consensus checklist. Eleven items were considered important information to be specified for understanding the validity of the results. Of these, three were considered essential: specification of the prior, source of the prior (when prior is informative), and the effect size point estimate with its credible interval. Conclusion: The checklist can help clinicians interpret the results of a phase III randomised clinical trial analysed by Bayesian methods, even clinicians with no particular knowledge of statistics, to ensure that the major elements of the statistical section are present and valid. Care should be taken in interpreting the results of a trial analysed by Bayesian methods that are not reported with these three essential items because the validity of the results cannot be established.

Sulphate-reducing bacteria (SRB) cause fouling, souring, corrosion and produce H2S during oil and gas production. Produced water obtained from Periquito (PQO) and Galo de Campina (GC) onshore oilfields in Brazil was investigated for SRB. Produced water with Postgate B, Postgate C and Baars media was incubated anaerobically for 20 days. DNA was extracted, 16S rDNA PCR amplified and fragments were sequenced using Illumina TruSeq. 4.2 million sequence reads were analysed and deposited at NCBI SAR accession number SRP149784. No significant differences in microbial community composition could be attributed to the different media but significant differences in the SRB were observed between the two oil fields. The dominant bacterial orders detected from both oilfields were Desulfovibrionales, Pseudomonadales and Enterobacteriales. The genus Pseudomonas was found predominantly in the GC oilfield and Pleomorphominas and Shewanella were features of the PQO oilfield. 11% and 7.6% of the sequences at GC and PQO were not classified at the genus level but could be partially identified at the order level. Relative abundances changed for Desulfovibrio from 29.8% at PQO to 16.1% at GC. Clostridium varied from 2.8% at PQO and 2.4% at GC. These data provide the first description of SRB from onshore produced water in Brazil and reinforce the importance of Desulfovibrionales, Pseudomonadales, and Enterobacteriales in produced water globally. Identifying potentially harmful microbes is an important first step in developing microbial solutions that prevent their proliferation.