20 research outputs found

    The variable internal structure of the Mycoplasma penetrans attachment organelle revealed by biochemical and microscopic analyses: implications for attachment organelle mechanism and evolution

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    Although mycoplasmas have small genomes, many of them, including the HIV-associated opportunist Mycoplasma penetrans, construct a polar attachment organelle (AO) that is used for both adherence to host cells and gliding motility. However, the irregular phylogenetic distribution of similar structures within the mycoplasmas, as well as compositional and ultrastructural differences among these AOs, suggests that AOs have arisen several times through convergent evolution. We investigated the ultrastructure and protein composition of the cytoskeleton-like material of the M. penetrans AO with several forms of microscopy and biochemical analysis, to determine whether the M. penetrans AO was constructed at the molecular level on principles similar to those of other mycoplasmas, such as Mycoplasma pneumoniae and Mycoplasma mobile. We found that the M. penetrans AO interior was generally dissimilar from that of other mycoplasmas, in that it exhibited considerable heterogeneity in size and shape, suggesting a gel-like nature. In contrast, several of the 12 potential protein components identified by mass spectrometry of M. penetrans detergent-insoluble proteins shared certain distinctive biochemical characteristics with M. pneumoniae AO proteins, although not with M. mobile proteins. We conclude that convergence between M. penetrans and M. pneumoniae AOs extends to the molecular level, leading to the possibility that the less organized material in both M. pneumoniae and M. penetrans is the substance principally responsible for the organization and function of the AO

    Potential molecular targets for narrow-spectrum agents to combat Mycoplasma pneumoniae infection and disease

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    As Mycoplasma pneumoniae macrolide resistance grows and spreads worldwide, it is becoming more important to develop new drugs to prevent infection or limit disease. Because other mycoplasma species have acquired resistance to other classes of antibiotics, it is reasonable to presume that M. pneumoniae can do the same, so switching to commonly used antibiotics like fluoroquinolones will not result in forms of therapy with long-term utility. Moreover, broad-spectrum antibiotics can have serious consequences for the patient, as these drugs may have severe impacts on the natural microbiota of the individual, compromising the health of the patient either short-term or long-term. Therefore, developing narrow-spectrum antibiotics that effectively target only M. pneumoniae and no more than a small portion of the microbiota is likely to yield impactful, positive results that can be used perhaps indefinitely to combat M. pneumoniae. Development of these agents requires a deep understanding of the basic biology of M. pneumoniae, in many areas deeper than what is currently known. In this review we discuss potential targets for new, narrow-spectrum agents and both the positive and negative aspects of selecting these targets, which include toxic molecules, metabolic pathways, and attachment and motility. By gathering this information together, we anticipate that it will be easier for researchers to evaluate topics of priority for study of M. pneumoniae

    Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes

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    La liste complète des auteurs est disponible sur la notice WOS : http://gateway.isiknowledge.com/gateway/Gateway.cgi?&GWVersion=2&SrcAuth=INRA&SrcApp=INRA&DestLinkType=FullRecord&DestApp=WOS&KeyUT=ISI:000253008800003International audienc

    Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes

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    La liste complète des auteurs est disponible sur la notice WOS : http://gateway.isiknowledge.com/gateway/Gateway.cgi?&GWVersion=2&SrcAuth=INRA&SrcApp=INRA&DestLinkType=FullRecord&DestApp=WOS&KeyUT=ISI:000253008800003International audienc

    The influence of bio-behavioural factors on tumour biology: pathways and mechanisms

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    Epidemiological studies indicate that stress, chronic depression and lack of social support might serve as risk factors for cancer development and progression. Recent cellular and molecular studies have identified biological processes that could potentially mediate such effects. This review integrates clinical, cellular and molecular studies to provide a mechanistic understanding of the interface between biological and behavioural influences in cancer, and identifies novel behavioural or pharmacological interventions that might help improve cancer outcomes

    Supportive care during treatment for breast cancer: Resource allocations in low- and middle-income countries. A Breast Health Global Initiative 2013 consensus statement

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    Breast cancer patients may have unmet supportive care needs during treatment, including symptom management of treatment-related toxicities, and educational, psychosocial, and spiritual needs. Delivery of supportive care is often a low priority in low- and middle-income settings, and is also dependent on resources available. This consensus statement describes twelve key recommendations for supportive care during treatment in low- and middle-income countries, identified by an expert international panel as part of the 5th Breast Health Global Initiative (BHGI) Global Summit for Supportive Care, which was held in October 2012, in Vienna, Austria. Panel recommendations are presented in a 4-tier resource-stratified table to illustrate how health systems can provide supportive care services during treatment to breast cancer patients, starting at a basic level of resource allocation and incrementally adding program resources as they become available. These recommendations include: health professional and patient and family education; management of treatment related toxicities, management of treatment-related symptoms of fatigue, insomnia and non-specific pain, and management of psychosocial and spiritual issues related to breast cancer treatment. Establishing supportive care during breast cancer treatment will help ensure that breast cancer patients receive comprehensive care that can help 1) improve adherence to treatment recommendations, 2) manage treatment-related toxicities and other treatment related symptoms, and 3) address the psychosocial and spiritual aspects of breast cancer and breast cancer treatments

    Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes.

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    Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response
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