TED Talks video with Maryn McKenna on Antibiotic Resistance
Penicillin changed everything. Infections that had previously killed were suddenly quickly curable. Yet as Maryn McKenna shares in this sobering talk, we’ve squandered the advantages afforded us by that and later antibiotics. Drug-resistant bacteria mean we’re entering a post-antibiotic world — and it won’t be pretty. There are, however, things we can do … if we start right now.
Systematic review and meta-analysis of cohort and case-control studies.
Embase, Medline, Cochrane Library, PubMed, CINAHL, and Scopus searched systematically with no restrictions on date, publication, or language to identify relevant studies. Supplementary efforts included searching relevant internet resources as well as hand searching the reference lists of included studies. Where published information was unclear or inadequate, corresponding authors were contacted for more information.
Cohort and case-control studies from high income countries were potentially eligible if they investigated the association between stillbirth in an initial pregnancy and risk of stillbirth in a subsequent pregnancy. Stillbirth was defined as fetal death occurring at more than 20 weeks’ gestation or a birth weight of at least 400 g. Two reviewers independently screened titles to identify eligible studies based on inclusion and exclusion criteria agreed a priori, extracted data, and assessed the methodological quality using scoring criteria from the critical appraisal skills programme. Random effects meta-analyses were used to combine the results of the included studies. Subgroup analysis was performed on studies that examined unexplained stillbirth.
13 cohort studies and three case-control studies met the inclusion criteria and were included in the meta-analysis. Data were available on 3 412 079 women with pregnancies beyond 20 weeks duration, of who 3 387 538 (99.3%) had had a previous live birth and 24 541 (0.7%) a stillbirth. A total of 14 283 stillbirths occurred in subsequent pregnancies, 606/24 541 (2.5%) in women with a history of stillbirth and 13 677/3 387 538 (0.4%) among women with no such history (pooled odds ratio 4.83, 95% confidence interval 3.77 to 6.18). 12 studies specifically assessed the risk of stillbirth in second pregnancies. Compared with women who had a live birth in their first pregnancy, those who experienced a stillbirth were almost five times more likely to experience a stillbirth in their second pregnancy (odds ratio 4.77, 95% confidence interval 3.70 to 6.15). The pooled odds ratio using the adjusted effect measures from the primary studies was 3.38 (95% confidence interval 2.61 to 4.38). Four studies examined the risk of recurrent unexplained stillbirth. Methodological differences between these studies precluded pooling the results.
The risk of stillbirth in subsequent pregnancies is higher in women who experience a stillbirth in their first pregnancy. This increased risk remained after adjusted analysis. Evidence surrounding the recurrence risk of unexplained stillbirth remains controversial.
Sources and more information
Risk of recurrent stillbirth: systematic review and meta-analysis, thebmj, 2015;350:h3080, 24 June 2015.
Women with history of stillbirth at ‘high risk of another’, NHS News, June 26 2015.
Clinical studies are designed to answer specific scientific questions
Clinical trials are essential to providing the scientific data to determine whether new drugs, diagnostics or procedures are both safe and effective when used to diagnose and treat people. Roche video, published on 28 May 2014, part of Drawn to Science series.
More info and videos
Carefully conducted clinical trials are performed in human volunteers to provide answers to important questions. Every new treatment is usually tested in three phases of clinical trials before regulatory agencies consider it safe and effective. Depending on product type and development stage, investigators initially enroll volunteers and/or patients into small pilot studies and subsequently conduct progressively larger scale comparative studies. As positive safety and efficacy data are gathered, the number of patients typically increases. Clinical trials can vary in size, and can involve a single research entity in one country or multiple entities in multiple countries.
Flibanserin: female love drug leaves a lot to be desired…
The FDA is about to approve Flibanserin, marketed as the “Viagra for women” who want to increase their libidos. But according to reports, the effects aren’t dazzling. And there are some rather significant side effects…
Sources: Flibanserin: female love drug leaves a lot to be desired via aNewDomain, 2015/06/04.
Global taskforce calls for research into everyday chemicals that may cause cancer
2015 Study Abstract
Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%.
To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals.
In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85).
Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety ‘Mode of Action’ framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.
Sources and more information
Global taskforce calls for research into everyday chemicals that may cause cancer, Brunel University, June 23, 2015.
Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead, Suppl_1/S254.full, January 31, 2015.
La transplantation utérine ; une alternative aux mères porteuses?
Après avoir fait le récit des événements qui ont précédé la première transplantation utérine ayant abouti à la naissance d’un enfant vivant et bien portant et fait un état des lieux, les auteurs exposent la législation française actuelle sur la greffe d’organes. Puis, ils abordent les aspects cliniques, insistant sur la complexité de l’acte chirurgical, le dilemme du choix entre donneuse en état de mort cérébrale ou décédée et donneuse vivante, et les indications chez la receveuse. Ils décrivent ensuite le traitement immunosuppresseur avant et pendant la grossesse, les complications plus ou moins graves qui peuvent en émailler le cours et la surveillance particulièrement attentive qu’elles nécessitent, mais aussi les doutes sur l’opportunité de l’allaitement maternel. Ils s’interrogent sur l’avenir de l’enfant à moyen et long terme, son développement psychomoteur et celui de son système immunitaire. Ils retracent les nombreuses et délicates questions éthiques que pose la transplantation utérine, qu’il s’agisse des particularités de la greffe d’utérus, qui n’est pas vitale mais permet de donner la vie, du choix entre transplantation avec donneuse en état de mort cérébrale ou donneuse vivante, de la pénurie d’organes à greffer, des risques courus par la receveuse, du devenir physique et psychologique de l’enfant, enfin du choix entre transplantation utérine et gestation pour autrui et de l’éventualité de dérives. En fait, la transplantation utérine est une chirurgie encore au stade expérimental et seuls l’avenir et le recueil exhaustif de toutes les données la concernant permettront de s’assurer de son bien fondé.
Low-Dose Exposures to Chemical Mixtures in the Environment linked to Human Cancer: Cause and Prevention
Low-dose exposures to common environmental chemicals that are deemed safe individually may be combining to instigate carcinogenesis, thereby contributing to the incidence of cancer. This risk may be overlooked by current regulatory practices and needs to be vigorously investigated.
Personalized or precision medicine maintains that medical care and public health will be radically transformed by prevention and treatment programs more closely targeted to the individual patient. These interventions will be developed by sequencing more genomes, creating bigger biobanks, and linking biological information to health data in electronic medical records (EMRs) or obtained by monitoring technologies. Yet the assumptions underpinning personalized medicine have largely escaped questioning.