296 research outputs found
Structural evolution of G-protein-coupled receptors: a sequence space approach
Class A G-protein-coupled receptors (GPCRs) provide a fascinating example of evolutionary success. In this review, we discuss how metric multidimensional scaling (MDS), a multivariate analysis method, complements traditional tree-based phylogenetic methods and helps decipher the mechanisms that drove the evolution of class A GPCRs. MDS provides low-dimensional representations of a distance matrix. Applied to a multiple sequence alignment, MDS represents the sequences in a Euclidean space as points whose interdistances are as close as possible to the distances in the alignment (the so-called sequence space). We detail how to perform the MDS analysis of a multiple sequence alignment and how to analyze and interpret the resulting sequence space. We also show that the projection of supplementary data (a property of the MDS method) can be used to straightforwardly monitor the evolutionary drift of specific subfamilies. The sequence space of class A GPCRs reveals the key role of mutations at the level of the TM2 and TM5 proline residues in the evolution of class A GPCRs
The Importance of Imaging Assessment Before Endovascular Repair of Thoracic Aorta
AbstractIndications for and experience with placement of endovascular stent grafts in the thoracic aorta are still evolving. Recent advances in imaging technologies have drastically boosted the role of pre-procedural imaging. The accepted diagnostic gold standard, digital subtraction angiography, is now being challenged by the state-of-the-art computed tomography angiography (CTA), magnetic resonance angiography (MRA) and trans-oesophageal echocardiography (TEE). Among these, technological advancements of multidetector computed tomography (MDCT) have propelled it to being the default modality used, optimising the balance between spatial and temporal resolutions and invasiveness. MDCT angiography allows the comprehensive evaluation of thoracic lesions in terms of morphological features and extent, presence of thrombus, relationship with adjacent structures and branches as well as signs of impending or acute rupture, and is routinely used in these settings.In this article, we review the current state-of-the-art radiological imaging for thoracic endovascular aneurysm repair (TEVAR), especially focusing on the role of MDCT angiography. After analysing the technical aspects for optimised imaging protocols for thoracic aortic diseases, we discuss pre-procedural determinants of candidacy, and how to formulate interventional plans based on cross-sectional imaging
In Vitro Effects of the Endocrine Disruptor p,p’-DDT on Human Follitropin Receptor
BACKGROUND:
1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p\u27-DDT) is a persistent environmental endocrine disruptor (ED). Several studies have shown an association between p,p\u27-DDT exposure and reproductive abnormalities.
OBJECTIVES:
To investigate the putative effects of p,p\u27-DDT on the human follitropin receptor (FSHR) function.
METHODS AND RESULTS:
We used Chinese hamster ovary (CHO) cells stably expressing human FSHR to investigate the impact of p,p\u27-DDT on FSHR activity and its interaction with the receptor. At a concentration of 5 μM p,p\u27-DDT increased the maximum response of the FSHR to follitropin by 32 ± 7.45%. However, 5 μM p,p\u27-DDT decreased the basal activity and did not influence the maximal response of the closely related LH/hCG receptor to human chorionic gonadotropin (hCG). The potentiating effect of p,p\u27-DDT was specific for the FSHR. Moreover, in cells that did not express FSHR, p,p\u27-DDT had no effect on cAMP response. Thus, the potentiating effect of p,p\u27-DDT was dependent on the FSHR. In addition, p,p\u27-DDT increased the sensitivity of FSHR to hCG and to a low molecular weight agonist of the FSHR, 3-((5methyl)-2-(4-benzyloxy-phenyl)-5-{[2-[3-ethoxy-4-methoxy-phenyl)-ethylcarbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-benzamide (16a). Basal activity in response to p,p\u27-DDT and potentiation of the FSHR response to FSH by p,p\u27-DDT varied among FSHR mutants with altered transmembrane domains (TMDs), consistent with an effect of p,p\u27-DDT via TMD binding. This finding was corroborated by the results of simultaneously docking p,p\u27-DDT and 16a into the FSHR transmembrane bundle.
CONCLUSION:p,p\u27-DDT acted as a positive allosteric modulator of the FSHR in our experimental model. These findings suggest that G protein-coupled receptors are additional targets of endocrine disruptor
Traitement médical de l’endométriose douloureuse sans infertilité, RPC Endométriose CNGOF-HAS
OBJECTIVE: To provide clinical practice guidelines for the management of painful endometriosis in women without infertility.
METHODS: Systematic review of the literature literature since 2006, level of evidence rating, external proofreading and grading of the recommendation grade by an expert group according to HAS methodology.
RESULTS: Combined hormonal contraceptives (COP) and the levonorgestrel-releasing intra-uterin system (LNG-IUS) are recommended as first-line hormonal therapies for the treatment of painful endometriosis (grade B). Second-line therapy relies on oral desogestrel microprogestative, etonogestrel-releasing implant, GnRH analogs (GnRHa) and dienogest (grade C). It is recommended to use add-back therapy containing estrogen in association with GnRHa (grade B). After endometriosis surgery, hormonal treatment relying on COP or LNG-IUS is recommended to prevent pain recurrence (grade B). COP is recommended to reduce the risk of endometrioma recurrence after surgery (grade B) but the prescription of GnRHa is not recommended (grade C). Continuous COP is recommended in case of dysmenorrhea (grade B). GnRHa is not recommended as first line endometriosis treatment for adolescent girl because of the risk of bone demineralization (grade B). The management of endometriosis-induced chronic pain requires an interdisciplinary evaluation. Physical therapies improving the quality of life such as yoga, relaxation or osteopathy can be proposed (expert agreement). Promising medical alternatives are currently under preclinical and clinical evaluation
Place des nouveaux traitements médicaux dans l’endométriose douloureuse, RPC Endométriose CNGOF-HAS
OBJECTIVE: The objective of this work is to evaluate the place of new treatments in the management of endometriosis outside the context of infertility.
METHODS: A review of the literature was conducted by consulting Medline data until July 2017.
RESULTS: Dienogest is effective compared to placebo in short term (NP2) and long term (NP4) for the treatment of painful endometriosis. In comparison with GnRH agonists, dienogest is also effective in terms of decreased pain and improved quality of life in non-operated patients (NP2) as well as for recurrence of lesions and symptomatology postoperatively (NP2). Data on GnRH antagonists, selective progesterone receptor modulators as well as selective inhibitors (anti-TNF-α, matrix metalloprotease inhibitors, angiogenesis growth factor inhibitors) are insufficient to provide evidence of interest in clinical practice for the management of painful endometriosis (NP3).
CONCLUSION: Dienogest is recommended as second-line therapy for the management of painful endometriosis (Grade B). Because of lack of evidence, aromatase inhibitors, elagolix, SERM, SPRM and anti-TNF-α are not recommended for the management of painful endometriosis (Grade C)
The angiotensin II type 2 receptor activates flow-mediated outward remodelling through T cells-dependent interleukin-17 production
AIMS:
The angiotensin II type 1 receptor (AT1R) through the activation of immune cells plays a key role in arterial inward remodelling and reduced blood flow in cardiovascular disorders. On the other side, flow (shear stress)-mediated outward remodelling (FMR), involved in collateral arteries growth in ischaemic diseases, allows revascularization. We hypothesized that the type 2 receptor (AT2R), described as opposing the effects of AT1R, could be involved in FMR.
METHODS AND RESULTS:
We studied FMR using a model of ligation of feed arteries supplying collateral pathways in the mouse mesenteric arterial bed in vivo. Seven days after ligation, diameter increased by 30% in high flow (HF) arteries compared with normal flow vessels. FMR was absent in mice lacking AT2R. At Day 2, T lymphocytes expressing AT2R were present preferentially around HF arteries. FMR did not occur in athymic (nude) mice lacking T cells and in mice treated with anti-CD3ε antibodies. AT2R activation induced interleukin-17 production by memory T cells. Treatment of nude mice or AT2R-deficient mice with interleukin-17 restored diameter enlargement in HF arteries. Interleukin-17 increased NO-dependent relaxation and matrix metalloproteinases activity, both important in FMR. Remodelling of feeding arteries in the skin flap model of ischaemia was also absent in AT2R-deficient mice and in anti-interleukin-17-treated mice. Finally, remodelling, absent in 12-month-old mice, was restored by a treatment with the AT2R non-peptidic agonist C21.
CONCLUSION:AT2R-dependent interleukin-17 production by T lymphocyte is necessary for collateral artery growth and could represent a new therapeutic target in ischaemic disorders
Endogenous sex steroids and risk of cervical carcinoma : results from the EPIC study
Background: Epidemiologic data and animal models suggest that, despite the predominant role of human papillomavirus infection, sex steroid hormones are also involved in the etiology of invasive cervical carcinoma (ICC). Methods: Ninety-nine ICC cases, 121 cervical intraepithelial neoplasia grade 3 (CIN3) cases and 2 control women matched with each case for center, age, menopausal status and blood collection-related variables, were identified in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Circulating levels of testosterone (T) and estradiol (E(2)); dehydroepiandrosterone sulfate (DHEAS); progesterone (premenopausal women); and sex hormone-binding globulin (SHBG) were measured using immunoassays. Levels of free (f) T and E(2) were calculated from absolute concentrations of T, E(2), and SHBG. Odds ratios (ORs) and 95% confidence intervals (CI) were computed using regularized conditional logistic regression. Results: Among premenopausal women, associations with ICC were observed for fT (OR for highest vs. lowest tertile 5.16, 95% CI, 1.50-20.1). SHBG level was associated with a significant downward trend in ICC risk. T, E(2), fE(2), and DHEAS showed nonsignificant positive association with ICC. Progesterone was uninfluential. Among postmenopausal women, associations with ICC were found for T (OR 3.14; 95% CI, 1.21-9.37), whereas E(2) and fT showed nonsignificant positive association. SHBG level was unrelated to ICC risk in postmenopausal women. No associations between any hormone and CIN3 were detected in either pre- or postmenopausal women. Conclusions: Our findings suggest for the first time that T and possibly E(2) may be involved in the etiology of ICC. Impact: The responsiveness of cervical tumors to hormone modulators is worth exploring. Cancer Epidemiol Biomarkers Prev; 20(12); 2532-40. (C) 2011 AACR
Roles of silica and lignin in horsetail ( Equisetum hyemale
This research deals with detailed analyses of silica and lignin distribution in horsetail with special reference to mechanical strength. Scanning electron images of a cross-section of an internode showed silica deposited densely only around the outer epidermis. Detailed histochemical analyses of lignin showed no lignin deposition in the silica-rich outer internodes of horsetail, while a characteristic lignin deposition was noticed in the vascular bundle in inner side of internodes. To analyze the structure of horsetail from a mechanical viewpoint, we calculated the response of a model structure of horsetail to a mechanical force applied perpendicularly to the long axis by a finite element method. We found that silica distributed in the outer epidermis may play the major structural role, with lignin's role being limited ensuring that the vascular bundle keep waterproof. These results were in contrast to more modern tall trees like gymnosperms, for which lignin provides mechanical strength. Lignin has the advantage of sticking to cellulose, hemicellulose, and other materials. Such properties make it possible for plants containing lignin to branch. Branching of tree stems aids in competing for light and other atmospheric resources. This type of branching was impossible for ancient horsetails, which relied on the physical properties of silica. From the evolutional view points, over millennia in trees with high lignin content, true branching, and many chlorophyll-containing leaves developed. (C) 2012 American Institute of Physics. [https://doi.org/10.1063/1.3688253]ArticleJOURNAL OF APPLIED PHYSICS. 111(4):044703 (2012)journal articl
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