Predatory prokaryotes: an emerging research opportunity

Predatory prokaryotes have evolved a unique strategy of obtaining energy and biosynthetic materials from their surroundings: acquiring them from other living bacterial cells. These types of microbes have been found in a diverse variety of environments, and may play an important role in modulating microbial population structure and dynamics, as has been hypothesized for marine viruses and possibly protists. Only one genus of predatory bacterium, Bdellovibrio, has been extensively described and studied, though several other examples have been reported in the literature. In this review, the four basic strategies used by currently described predatory prokaryotes will be discussed: "wolfpack" group predation, epibiotic attachment, direct cytoplasmic invasion, and periplasmic invasion. Special adaptations to each approach will be considered, and compared overall to the genetic and biochemical characteristics of symbiotic or pathogenic prokaryotes living within eukaryotic cells. Two specific examples of predatory microbes, Bdellovibrio and Ensifer, will be described in terms of predation strategy, association with host cells, and host range. The prospects for bringing to bear the tools of molecular microbial genetics to the study of predatory prokaryotes will be explored, using current research with Bdellovibrio and Ensifer as examples.     

Open access :an opportunity for biomedical research

Open access within the scientific community depends on the scientific context and the practices of the field. In the biomedical domain, the communication of research results is characterised by the importance of the peer reviewing process, the existence of a hierarchy among journals and the transfer of copyright to the editor. Biomedical publishing has become a lucrative market and the growth of electronic journals has not helped lower the costs. Indeed, it is difficult for today's public institutions to gain access to all the scientific literature. Open access is thus imperative, as demonstrated through the positions taken by a growing number of research funding bodies, the development of open access journals and efforts made in promoting open archives. This article describes the setting up of an Inserm portal for publication in the context of the French national protocol for open-access self-archiving and in an international context.     

Biometry has to improve the quality of decision making both in biomedical research and in clinical practice

The leading principles of biometrical design, evaluation and decision making in biomedicine can be summarized as follows: (1) formulation of the problem to be solved and of the specific question(s) to be answered; (2) definition of the population in study, ways of sampling and manoeuvres (treatments); (3) determining the kind and number of variables (time intervals of measurement, investigated biomedical parameters); (4) performing the pilot study if necessary (to arrange randomized blocks, to form hypotheses); (5) formulation of zero (alternative) hypothesis, setting the values of alpha(beta) risk; (6) ordering the sample sizes; (7) testing the type of statistical distribution and the homoscedasticity of the obtained data; (8) calculation of the point and interval (confidence, tolerance) estimates; (9) performing the chosen tests, e.g. on the significance of differences or correlations; and (10) the conclusions for science and practice, with eventual return to point (1) on a higher level of knowledge.     

关于生物学研究模型教学的一点思考

如何利用现有的资源提高生物学教学效果.应该补充现代生物学发展历史和生物研究多样化模型两方面的知识.提供了学生应该掌握的研究历史和研究模型方面的基本脉络.     

Investigating dairy microbiome: an opportunity to ensure quality,safety and typicity

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Cardiac to cancer: Connecting connexins to clinical opportunity

Gap junctions and their connexin components are indispensable in mediating the cellular coordination required for tissue and organ homeostasis. The critical nature of their existence mandates a connection to disease while at the same time offering therapeutic potential. Therapeutic intervention may be offered through the pharmacological and molecular disruption of the pathways involved in connexin biosynthesis, gap junction assembly, stabilization, or degradation. Chemical inhibitors aimed at closing connexin channels, peptide mimetics corresponding to short connexin sequences, and gene therapy approaches have been incredibly useful molecular tools in deciphering the complexities associated with connexin biology. Recently, therapeutic potential in targeting connexins has evolved from basic research in cell-based models to clinical opportunity in the form of human trials. Clinical promise is particularly evident with regards to targeting connexin43 in the context of wound healing. The following review is aimed at highlighting novel advances where the pharmacological manipulation of connexin biology has proven beneficial in animals or humans.     

Norway rats reciprocate help according to the quality of help they received

Direct reciprocity, according to the decision rule ‘help someone who has helped you before’, reflects cooperation based on the principle of postponed benefits. A predominant factor influencing Homo sapiens'' motivation to reciprocate is an individ­ual''s perceived benefit resulting from the value of received help. But hitherto it has been unclear whether other species also base their decision to cooperate on the quality of received help. Previous experiments have demonstrated that Norway rats, Rattus norvegicus, cooperate using direct reciprocity decision rules in a variant of the iterated Prisoner''s Dilemma, where they preferentially help cooperators instead of defectors. But, as the quality of obtained benefits has not been varied, it is yet unclear whether rats use the value of received help as decision criterion to pay help back. Here, we tested whether rats distinguish between different cooperators depending purely on the quality of their help. Our data show that a rat''s propensity to reciprocate help is, indeed, adjusted to the perceived quality of the partner''s previous help. When cooperating with two conspecific partners expending the same effort, rats apparently rely on obtained benefit to adjust their level of returned help.     

Mindfulness-Based Interventions for People Diagnosed with a Current Episode of an Anxiety or Depressive Disorder: A Meta-Analysis of Randomised Controlled Trials

Objective

Mindfulness-based interventions (MBIs) can reduce risk of depressive relapse for people with a history of recurrent depression who are currently well. However, the cognitive, affective and motivational features of depression and anxiety might render MBIs ineffective for people experiencing current symptoms. This paper presents a meta-analysis of randomised controlled trials (RCTs) of MBIs where participants met diagnostic criteria for a current episode of an anxiety or depressive disorder.

Method

Post-intervention between-group Hedges g effect sizes were calculated using a random effects model. Moderator analyses of primary diagnosis, intervention type and control condition were conducted and publication bias was assessed.

Results

Twelve studies met inclusion criteria (n = 578). There were significant post-intervention between-group benefits of MBIs relative to control conditions on primary symptom severity (Hedges g = −0.59, 95% CI = −0.12 to −1.06). Effects were demonstrated for depressive symptom severity (Hedges g = −0.73, 95% CI = −0.09 to −1.36), but not for anxiety symptom severity (Hedges g = −0.55, 95% CI = 0.09 to −1.18), for RCTs with an inactive control (Hedges g = −1.03, 95% CI = −0.40 to −1.66), but not where there was an active control (Hedges g = 0.03, 95% CI = 0.54 to −0.48) and effects were found for MBCT (Hedges g = −0.39, 95% CI = −0.15 to −0.63) but not for MBSR (Hedges g = −0.75, 95% CI = 0.31 to −1.81).

Conclusions

This is the first meta-analysis of RCTs of MBIs where all studies included only participants who were diagnosed with a current episode of a depressive or anxiety disorder. Effects of MBIs on primary symptom severity were found for people with a current depressive disorder and it is recommended that MBIs might be considered as an intervention for this population.     

教学科研相得益彰提高遗传学教学质量

遗传学是生命科学领域的一门重要的基础理论学科。遗传学的教学内容日益更新,逐渐向更深层次拓展。为适应遗传学的迅速发展和培养创新型人才的要求,将遗传学发展的科研成果适时地反映到遗传学课程的教学内容中,有利于增强知识的系统性,提高学习遗传学的趣味性,把握学科知识的整体性。对于提高教学质量,培养学生的创新精神和科研素质起到切实可行的推进作用。     

The Ixodes scapularis Genome Project: an opportunity for advancing tick research

The Ixodes scapularis Genome Project (IGP), the first to sequence a tick genome, will provide an unparalleled resource for studying tick biology and tick-host-pathogen relationships, and identifying novel targets for tick and tick-borne disease control. The IGP will be the first genomic analysis of a member of the subphylum Chelicerata and will accelerate the pace of tick research. The challenge for scientists is to translate IGP data into public health benefits.     

Using data to improve surrogate consent for clinical research with incapacitated adults

Current practice relies on surrogates to enroll incapacitated adults in research. Yet, it is unclear to what extent this practice protects adults who have lost the ability to consent for themselves. To address this question, we conducted two literature searches to identify articles which report empirical data on three issues central to protecting adults who have lost the ability to consent: (1) adults' willingness to participate in research should they lose the ability to consent; (2) adults' willingness to allow a surrogate to make research decisions for them; and (3) the extent to which surrogates' enrollment decisions are consistent with their charges' preferences and values. These searches identified 21 articles, representing 20 distinct datasets. The data indicate that many adults are willing to participate in research should they lose the ability to consent, and many are willing to allow their family members to make research decisions for them if they become incapacitated. The data also raise concern that surrogates may be making research enrollment decisions that, in some cases, are inconsistent with their charges' preferences and values. These findings suggest that modifications to current practice should be considered to better protect adults who have lost the ability to consent. One option would be to require, in addition to surrogate permission and subject assent, sufficient evidence that enrollment is consistent with the individual's preferences and values.     

Treatment Success in Cancer: Industry Compared to Publicly Sponsored Randomized Controlled Trials

Objective

To assess if commercially sponsored trials are associated with higher success rates than publicly-sponsored trials.

Study Design and Settings

We undertook a systematic review of all consecutive, published and unpublished phase III cancer randomized controlled trials (RCTs) conducted by GlaxoSmithKline (GSK) and the NCIC Clinical Trials Group (CTG). We included all phase III cancer RCTs assessing treatment superiority from 1980 to 2010. Three metrics were assessed to determine treatment successes: (1) the proportion of statistically significant trials favouring the experimental treatment, (2) the proportion of the trials in which new treatments were considered superior according to the investigators, and (3) quantitative synthesis of data for primary outcomes as defined in each trial.

Results

GSK conducted 40 cancer RCTs accruing 19,889 patients and CTG conducted 77 trials enrolling 33,260 patients. 42% (99%CI 24 to 60) of the results were statistically significant favouring experimental treatments in GSK compared to 25% (99%CI 13 to 37) in the CTG cohort (RR = 1.68; p = 0.04). Investigators concluded that new treatments were superior to standard treatments in 80% of GSK compared to 44% of CTG trials (RR = 1.81; p<0.001). Meta-analysis of the primary outcome indicated larger effects in GSK trials (odds ratio = 0.61 [99%CI 0.47–0.78] compared to 0.86 [0.74–1.00]; p = 0.003). However, testing for the effect of treatment over time indicated that treatment success has become comparable in the last decade.

Conclusions

While overall industry sponsorship is associated with higher success rates than publicly-sponsored trials, the difference seems to have disappeared over time.     

Efficacy of Thermotherapy to Treat Cutaneous Leishmaniasis: A Meta-Analysis of Controlled Clinical Trials

Introduction

The efficacy of thermotherapy for the treatment of cutaneous leishmaniasis presents diverse results with low statistical power.

Objective

To evaluate the efficacy of thermotherapy to treat cutaneous leishmaniasis.

Methods

A meta-analysis of controlled clinical trials in 12 databases based on the implementation of a research protocol with inclusion and exclusion criteria and an assessment of methodological quality. The reproducibility and completeness were guaranteed in the information search and extraction. Heterogeneity, sensitivity and publication bias were assessed by graphical methods (Galbraith, L''Abblé, funnel plot, Egger plot, and influence plot) and analytical methods (DerSimonian-Laird, Begg and Egger). Random-effects forest plots were constructed, and a cumulative meta-analysis was performed.

Results

Eight studies were included with 622 patients who underwent thermotherapy, with an efficacy of 73.2% (95% confidence interval (CI) = 69.6-76.7%), and with 667 patients who underwent systemic treatment, with an efficacy of 70.6% (95% CI=67.1-74.1%). Heterogeneity between studies, good sensitivity for the combined measure, and no publication bias were observed. The relative risk for comparison of the efficacy of treatment was 1.02 (95%CI=0.91, 1.15), showing that the effectiveness of thermotherapy is equal to that of pentavalent antimonial drugs.

Conclusion

Due to its efficacy, greater safety and lower cost, thermotherapy should be the first treatment option for cutaneous leishmaniasis in areas where the prevalence of the mucocutaneous form is low and in patients with contraindications to systemic treatment, such as kidney, liver and heart diseases, as well as in pregnant women, infants, and patients with human immunodeficiency virus infection/acquired immune deficiency syndrome.