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The results indicate that oxidation of CO to CO 2 supplies electrons for reduction of CO 2 to a methyl group by steps and enzymes of the pathway for CO 2 reduction determined for other methane-producing species. However, proteomic and quantitative RT-PCR results suggest that reduction of the methyl group to methane involves novel methyltransferases and a coenzyme F 420H2:heterodisulfide oxidoreductase system that generates a proton gradient for ATP synthesis not previously described for pathways reducing CO 2 to methane. Biochemical assays support a role for the oxidoreductase, and transcriptional mapping identified an unusual operon structure encoding the oxidoreductase. The proteomic results further indicate that acetate is synthesized from the methyl group and CO by a reversal of initial steps in the pathway for conversion of acetate to methane that yields ATP by substrate level phosphorylation. The results indicate that M. acetivorans utilizes a pathway distinct from all known CO 2 reduction pathways for methane formation that reflects an adaptation to the marine environment. Finally, the pathway supports the basis for a recently proposed primitive CO-dependent energy-conservation cycle that drove and directed the early evolution of life on Earth.anaerobic ͉ Archaea ͉ carbon monoxide C arbon monoxide (CO), an atmospheric pollutant that binds tightly to hemoglobin, is held below toxic levels in part by both aerobic and anaerobic microbes (1). The microbial metabolism of CO is an important component of the global carbon cycle (1, 2), and CO is believed to have been present in the atmosphere of early Earth that fueled the evolution of primitive metabolisms (3-7). Investigations of aerobic species from the Bacteria domain have contributed important insights into microbial CO oxidation (8, 9), as have investigations of anaerobes from the Bacteria domain that conserve energy by coupling CO oxidation to H 2 evolution (10-12). Further understanding has been derived from studies of CO-using anaerobes from the Bacteria domain that conserve energy by oxidizing CO and reducing CO 2 to acetate (13,14) or reducing sulfate to sulfide (15). Far less is known for pathways of the few CO-using species in the Archaea domain that have been described. Methanothermobacter thermautotrophicus, Methanosarcina barkeri, and Methanosarcina acetivorans obtain energy for growth by converting CO to methane (16)(17)(18)(19)(20). Although methane formation from CO first was reported in 1947 (21), a comprehensive understanding of the overall pathway for any species has not been reported. It is postulated that M. barkeri oxidizes CO to H 2 , and the H 2 is reoxidized to provide electrons for reducing CO 2 to methane (16). It is postulated further that H 2 production is essential for ATP synthesis during growth on CO (16,22,23). M. acetivorans was isolated from marine sediments where giant kelp is decomposed to methane (24). The flotation bladders of kelp contain CO that is a presumed substrate for M. acetivorans in nature. M. acetivorans produ...

Introduction: Cannabis has been used for medical purposes across the world for centuries. As states and countries implement medical and recreational cannabis policies, increasing numbers of people are using cannabis pharmacotherapy for pain. There is a theoretical rationale for cannabis' efficacy for pain management, although the subjective pain relief from cannabis may not match objective measurements of analgesia. As more patients turn to cannabis for pain relief, there is a need for additional scientific evidence to evaluate this increase.Materials and Methods: Research for this review was performed in the PubMed/National Library of Medicine database.Discussion: Preclinical studies demonstrate a narrow therapeutic window for cannabis as pharmacotherapy for pain; the body of clinical evidence for this indication is not as extensive. A recent meta-analysis of clinical trials of cannabis and cannabinoids for pain found modest evidence supporting the use of cannabinoid pharmacotherapy for pain. Recent epidemiological studies have provided initial evidence for a possible reduction in opioid pharmacotherapy for pain as a result of increased implementation of medical cannabis regimens.Conclusion: With increased use of medical cannabis as pharmacotherapy for pain comes a need for comprehensive risk-benefit discussions that take into account cannabis' significant possible side effects. As cannabis use increases in the context of medical and recreational cannabis policies, additional research to support or refute the current evidence base is essential to attempt to answer the questions that so many healthcare professionals and patients are asking.

UTHORSHIP IN BIOMEDICALpublication provides recognition while establishing accountability and responsibility. Guest authorship has been defined as the designation of an individual who does not meet authorship criteria as an author. 1,2 It was identified in 16% of research articles, 26% of review articles, and 21% of editorials in a survey of 6 peer-reviewed medical journals, 3 in addition to 41% of Cochrane reviews. 4 Ghostwriting has been defined as the failure to designate an individual (as an author) who has made a substantial contribution to the research or writing of a manuscript. 1 Ghostwriting was demonstrated in 13% of research articles, 10% of review articles, 6% of editorials, and 11% of Cochrane reviews 3,4 ; other research has found similar rates. 5 Two studies have characterized the practices of guest authorship and ghostwriting using industry documents, one examining practices related to gabapentin by Pfizer Inc and Parke-Davis, Division of Warner-Lambert Company, 6 the other sertraline by Pfizer Inc. 7 However, these studies were focused on how the research and publication strat-See also pp 1813 and 1833.

Documentary evidence shows that ADVANTAGE is an example of marketing framed as science. The documents indicate that ADVANTAGE was a seeding trial developed by Merck's marketing division to promote prescription of Vioxx (rofecoxib) when it became available on the market in 1999.

Background Craving is viewed as a core feature of substance use disorders and has been shown to predict future drug use, particularly over the short term. Accordingly, craving is often assessed in treatment settings as a marker of risk for subsequent drug use. The identification of the briefest measure that maintains predictive validity is of particular value for both clinical and research settings to minimize assessment burden while maintaining utility for the prediction of use. Methods Data from a multi-site clinical trial of treatment for prescription opioid dependence were examined to evaluate whether a brief, 3-item craving scale administered each week predicted urine-confirmed self report of prescription opioid use in the subsequent week. Logistic regression models examining the association between craving and presence or absence of opioid use in the following week were conducted, controlling for opioid use in the previous week, treatment condition, and lifetime history of heroin use. Results Greater craving was associated with a higher odds of prescription opioid use in the following week. For each one-unit increase on this 10-point scale, the odds of using opioids in the subsequent week was 17% higher. In addition to an item assessing urges, items assessing cue-induced craving and perceived likelihood of relapse in an environment where drugs were previously used contributed uniquely to this association. Conclusions A brief measure of prescription opioid craving predicted prescription opioid use among individuals in treatment. This measure offers an efficient strategy to inform the assessment of risk for use in this population.

Increasing evidence indicates that smoking cues contribute to nicotine self-administration and attenuating conditioned reactivity to smoking cues may aid abstinence of smoking and prevention of smoking relapse in individuals with nicotine dependence. Based on prior studies showing that the partial N-methyl-d-aspartate (NMDA) agonist d-cycloserine (DCS) facilitates extinction of learned fear during behavioral exposure therapy in humans and facilitates extinction of cocaine-induced conditioned place preference in animals, we evaluated whether DCS would have potential for reducing reactivity to smoking cues when combined with cue exposure treatment in humans with nicotine dependence. In this double-blind placebo controlled pilot laboratory study, twenty-five smokers were recruited from the general community and randomized to DCS or placebo, plus cue exposure therapy. DCS significantly attenuated smoking cue reactivity in response to in-vivo smoking cues based on physiological reactivity and subjective urge-to-smoke ratings and led to a significantly smaller expired carbon monoxide (CO) level at the 1-week follow-up compared to placebo, although exploratory analyses indicated no effect on smoking behavior overall. These findings provide promising support for DCS combined with cue exposure therapy in attenuating conditioned reactivity to smoking cues.

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