Random and targeted transgene insertion in Caenorhabditis elegans using a modified Mos1 transposon.

We have generated a recombinant Mos1 transposon that can insert up to 45-kb transgenes into the Caenorhabditis elegans genome. The minimal Mos1 transposon (miniMos) is 550 bp long and inserts DNA into the genome at high frequency (~60% of injected animals). Genetic and antibiotic markers can be used for selection, and the transposon is active in C. elegans isolates and Caenorhabditis briggsae. We used the miniMos transposon to generate six universal Mos1-mediated single-copy insertion (mosSCI) landing sites that allow targeted transgene insertion with a single targeting vector into permissive expression sites on all autosomes. We also generated two collections of strains: a set of bright fluorescent insertions that are useful as dominant, genetic balancers and a set of lacO insertions to track genome position.

Casein Kinase 1δ Stabilizes Mature Axons by Inhibiting Transcription Termination of Ankyrin.

After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.

Clinical review: Antiandrogens for the treatment of hirsutism: a systematic review and metaanalyses of randomized controlled trials.

CONTEXT: The relative efficacy of antiandrogens for the treatment of hirsutism remains unclear. OBJECTIVE: We performed a systematic review and metaanalyses of randomized controlled trials (RCTs) evaluating the effect of antiandrogens on hirsutism. DATA SOURCES: We used librarian-designed search strategies for MEDLINE, EMBASE, and Cochrane CENTRAL (up to May 2006), review of reference lists, and contact with hirsutism experts to identify eligible RCTs. STUDY SELECTION: Eligible studies were RCTs of at least 6 months of antiandrogen use in women with hirsutism. Reviewers, with acceptable chance-adjusted agreement (kappa = 0.72), independently assessed eligibility. DATA EXTRACTION: Reviewers used structured forms to assess and collect methodological quality (allocation concealment, blinding, and loss to follow-up) and study data. DATA SYNTHESIS: Of 348 candidate studies, 12 were eligible (18 comparisons). Their methodological quality was low. Random-effects metaanalyses showed that compared with placebo, antiandrogens reduce Ferriman-Gallwey scores by 3.9 [95% confidence interval (CI), 2.3-5.4; inconsistency (I(2)) = 0%]. When compared with metformin, spironolactone reduced hirsutism scores by 1.3 (CI, 0.03-2.6) and flutamide by 5.0 (CI, 3.0-7.0; I(2) = 0%). For these interventions, two to five women need to receive treatment for one to notice improvement. Spironolactone or finasteride in combination with contraceptives (1.7; CI, 0.1-3.3; I(2) = 0%) or flutamide with metformin (4.6; CI, 1.3-7.9; I(2) = 40%) appear superior to monotherapy with contraceptives and metformin, respectively. Only three RCTs reported patient self-assessments of hirsutism. CONCLUSIONS: Weak evidence suggests antiandrogens are mildly effective agents for the treatment of hirsutism.

Clinical review: Insulin sensitizers for the treatment of hirsutism: a systematic review and metaanalyses of randomized controlled trials.

CONTEXT: Insulin sensitizers, including metformin and thiazolidinediones (TZDs), improve hyperinsulinemia and reproductive dysfunctions in some women with hyperandrogenism. The extent to which these agents improve hirsutism remains unclear. OBJECTIVE: Our objective was to conduct a systematic review and metaanalyses of randomized controlled trials of metformin or TZDs for the treatment of hirsutism. DATA SOURCES: We searched the following databases: MEDLINE, EMBASE, and Cochrane CENTRAL (up to May 2006). Review of reference lists and contact with hirsutism experts further identified candidate trials. STUDY SELECTION: Reviewers working independently and in duplicate, with acceptable chance-adjusted agreement (kappa = 0.72), determined trial eligibility. Eligible trials randomly assigned women with hirsutism to at least 6 months of insulin sensitizers or control and measured hirsutism outcomes. DATA EXTRACTION: Reviewers working independently and in duplicate determined the methodological quality of trials and collected data on patient characteristics, interventions, and outcomes. DATA SYNTHESIS: Of 348 candidate studies, 16 trials (22 comparisons) were eligible. The methodological quality of these trials was low. Random-effects metaanalyses showed a small decrease in Ferriman-Gallwey scores in women treated with insulin sensitizers compared with placebo [pooled weighted mean difference (WMD) of -1.5; 95% confidence interval (CI), -2.8 to -0.2; inconsistency (I(2)) = 75%]. There was no significant difference between insulin sensitizers and oral contraceptives (WMD of -0.5; CI, -5.0, 3.9; I(2) = 79%). Metformin was inferior to both spironolactone (WMD of 1.3; CI, 0.03, 2.6) and flutamide (WMD of 5.0; CI, 3.0, 7.0; I(2) = 0%). CONCLUSIONS: Imprecise and inconsistent evidence of low to very low quality suggests that insulin sensitizers provide limited or no important benefit for women with hirsutism.

Systematic reviewers commonly contact study authors but do so with limited rigor.

OBJECTIVES: Author contact can enhance the quality of systematic reviews. We conducted a systematic review of the practice of author contact in recently published systematic reviews to characterize its prevalence, quality, and results. STUDY DESIGN AND SETTING: Eligible studies were systematic reviews of efficacy published in 2005-2006 in the 25 journals with the highest impact factor publishing systematic reviews in clinical medicine and the Cochrane Library, identified by searching MEDLINE, EMBASE, and the Cochrane Library. Two researchers determined whether and why reviewers contacted authors. To assess the accuracy of the abstracted data, we surveyed reviewers by e-mail. RESULTS: Forty-six (50%) of the 93 eligible systematic reviews published in top journals and 46 (85%) of the 54 eligible Cochrane reviews reported contacting authors of eligible studies. Requests were made most commonly for missing information: 40 (76%) clinical medicine reviews and 45 (98%) Cochrane reviews. One hundred and nine of 147 (74%) reviewers responded to the survey, and reported a higher rate of author contact than apparent from the published record. CONCLUSION: Although common, author contact is not a universal feature of systematic reviews published in top journals and the Cochrane Library. The conduct and reporting of author contact purpose, procedures, and results require improvement.

Clinical consequences of withholding versus administering renin-angiotensin-aldosterone system antagonists in the preoperative period.

BACKGROUND: Hospitalists involved in perioperative care either stop or continue until the day of surgery renin-angiotensin-aldosterone system antagonists (either angiotensin-converting enzyme inhibitors [ACEI] or angiotensin II receptor subtype 1 antagonists [ARA]) in patients who use these agents chronically. This practice variation reflects uncertainty regarding the risks and benefits of either approach. PURPOSE: The purpose of this study was to assess the clinical consequences of preoperatively continuing versus withholding ACEI/ARAs in patients treated chronically with these agents. DATA SOURCES AND STUDY SELECTION: We comprehensively searched 7 major electronic databases, considered references from selected reviews, hand-searched journals, and communicated with experts. We included randomized trials and observational studies. DATA EXTRACTION: We evaluated the relative risk (RR) of hypotension requiring vasopressors and of myocardial infarction in patients who did or did not receive an immediate preoperative dose of ACEI or ARA. DATA SYNTHESIS: Random-effects meta-analysis from 5 studies totaling 434 patients suggested that patients receiving an immediate preoperative ACEI/ARA dose were more likely (RR 1.50, 95% CI 1.15-1.96) to develop hypotension requiring vasopressors at or shortly after induction of anesthesia. Sufficient data were not available to assess other outcomes. CONCLUSION: Preoperative administration of ACEI/ARAs increases intraoperative hypotension. The long-term clinical consequences of continuing versus withholding preoperative ACEI/ARAs are unknown. This uncertainty stems in part from the absence to date of randomized trials designed specifically to examine patient-important consequences of this decision.