31 research outputs found

    Conformational Plasticity of proNGF

    Get PDF
    Nerve Growth Factor is an essential protein that supports neuronal survival during development and influences neuronal function throughout adulthood, both in the central and peripheral nervous system. The unprocessed precursor of NGF, proNGF, seems to be endowed with biological functions distinct from those of the mature protein, such as chaperone-like activities and apoptotic and/or neurotrophic properties. We have previously suggested, based on Small Angle X-ray Scattering data, that recombinant murine proNGF has features typical of an intrinsically unfolded protein. Using complementary biophysical techniques, we show here new evidence that clarifies and widens this hypothesis through a detailed comparison of the structural properties of NGF and proNGF. Our data provide direct information about the dynamic properties of the pro-peptide and indicate that proNGF assumes in solution a compact globular conformation. The N-terminal pro-peptide extension influences the chemical environment of the mature protein and protects the protein from proteolytic digestion. Accordingly, we observe that unfolding of proNGF involves a two-steps mechanism. The distinct structural properties of proNGF as compared to NGF agree with and rationalise a different functional role of the precursor

    Les variants de signification indéterminée des gènes de prédisposition au cancer du sein et de l’ovaire : enquête concernant les pratiques des gynécologues et des généticiens

    No full text
    Introduction: Genetic screening is now a routine part of clinical practice. Some of the variants, called "variants of undetermined significance" (VUSs), have unknown pathogenicity. They concern up to 10-15% of the cases in BRCA1/2. Our objective was to evaluate how gynecologists understand a VUS for susceptibility gene to breast and ovarian cancer. Materials and methods: 477 gynecologists, and 319 medical geneticists, or genetic counselors, were invited to complete an online survey from April to July 2019. Results: Regarding the questionnaire for gynecologists, 50 people answered, and 55 people answered for geneticists survey. A majority of gynecologist have reported being aware of VUSs existence (84%, n=42) and provided the correct information (84%, n=42). Regarding breast screening, evaluated by two short clinical cases, only 6% (n=3) and 12% (n=6) of respondents advised adequate surveillance. About an eventual risk-reducing surgery, gynecologists are more interventionist than geneticists (mastectomy p = 0.001; salpingooophorectomy p<0.0001) in presence of a VUS. Conclusion: The management recommended by gynecologists for VUS patients is heterogeneous, both for breast screening and for breast and ovarian risk-reduction surgery. These data encourage a multidisciplinary approach as well as the continuation of training efforts in a field where knowledge is rapidly developing.Introduction : Le dépistage génétique fait actuellement partie de la pratique clinique courante. Certains variants retrouvés présentent une pathogénicité inconnue, et sont appelés « variants de signification indéterminée » (VUS). Ils représentent jusqu’à 10-15% des altérations de BRCA1/2. L’objectif de notre étude était d’évaluer la façon dont les gynécologues interprètent le dépistage d’un VUS portant sur un gène de prédisposition au cancer du sein et de l’ovaire. Matériel et méthodes : 477 gynécologues, et 319 généticiens ou conseillers en génétique ont été invités à répondre à un questionnaire en ligne d’avril à juillet 2019. Résultats : En ce qui concerne le questionnaire diffusé aux gynécologues 50 personnes ont répondu et concernant celui des généticiens 55 personnes. A propos des VUS : la majorité des gynécologues déclarent connaitre leur existence (84 %, n=42) et donnent une information correcte (84 %, n=42). Concernant la surveillance sénologique, évaluée par deux cas cliniques courts : seul 6 % (n=3) et 12 % (n=6) des répondants ont conseillé une surveillance jugée comme adéquate. Concernant une éventuelle chirurgie prophylactique les gynécologues sont plus interventionnistes que les généticiens en présence d’un VUS. Conclusion : La prise en charge préconisée par les gynécologues aux patientes porteuses de VUS est hétérogène, tant pour la surveillance que pour les chirurgies prophylactiques du cancer du sein et de l’ovaire. Ces données viennent encourager la pluridisciplinarité et la poursuite des efforts de formation dans un domaine où les connaissances évoluent très rapidement

    Caregiver experiences with accessing sickle cell care and the use of telemedicine

    Get PDF
    Background: Sickle cell disease (SCD) is associated with a wide range of complications. However, a multitude of barriers prevent SCD patients from receiving adequate healthcare, including difficulties with transportation and lack of provider knowledge about disease sequelae. Importantly, studies have demonstrated the benefits of telemedicine in addressing barriers to healthcare. While previous studies have identified barriers to care through quantitative methods, few studies have explored barriers which affect the pediatric SCD patient population in the Midwest, wherein the geographical landscape can prohibit healthcare access. Furthermore, few studies have established acceptability of telemedicine among caregivers and patients with SCD. Methods: This study aims to increase understanding of barriers to care and perceptions of telemedicine by caregivers of pediatric SCD patients in a medically under-resourced area in the Midwest. Researchers conducted semi-structured interviews with caregivers of children with SCD. The interviews were audio-recorded and transcribed. Thematic analyses were performed. Results: Researchers interviewed 16 caregivers of 15 children with SCD. Thematic analyses of the interview transcripts revealed four broad themes regarding caregiver burden/stress, both facilitators and barriers to SCD healthcare, and general thoughts on the acceptability/usefulness of telemedicine. Conclusion: This qualitative study describes common burdens faced by caregivers of SCD, barriers to and facilitators of SCD care in the Midwest, and caregiver perceptions of the usefulness and efficacy of telemedicine for SCD care

    Similar length of colon is removed regardless of localization in right-sided colonic cancer surgery

    No full text
    International audienceBACKGROUND:Colorectal cancers represent a heterogenous group of tumours. While left segmental colectomy is an accepted and oncologically safe practice for left-sided colonic cancer (CC), some authors suggest that limited segmental resection of right-sided cancer should be debated in order to preserve length of the resected colon. To our knowledge, caecum and ascending CC have not been analysed as different groups of tumours. The objective of this study was to assess if, retrospectively, surgical treatment of caecal cancer differed from ascending CC.METHODS:A review of all consecutive patients with right colonic resection for cancer admitted to the University hospital of Grenoble from January 2005 to August 2016 was performed. Length of resected colon was compared between caecal primary and ascending CC. Other technical and pathological aspects were analysed such as minimal invasive surgery and number of harvested lymph nodes from anatomic specimens.RESULTS:Among operated patients, tumour was localized pre-operatively on caecum in 110 cases and on the right ascending colon in 119 cases. Pre-operative localization had no effect on resected colon length (mean 24.5 cm, 24 ± 10.34 versus 25 cm ± 7.28, P = 0.95), on the number of harvested lymph nodes with a mean of 15 (±7.6) nodes in the caecal group versus 15.2 (±7.3) (P = 0.72). We noticed 15 cases of discordance between pre- and post-operative localization (4 versus 11, P = 0.08).CONCLUSION:Length of resected colon does not differ depending on localization of tumour in our center

    NO signaling in plant immunity: A tale of messengers

    No full text
    International audienceNitric oxide (NO) is a free radical gas involved in a myriad of plant physiological processes including immune responses. How NO mediates its biological effects in plant facing microbial pathogen attack is an unresolved question. Insights into the molecular mechanisms by which it propagates signals reveal the contribution of this simple gas in complex signaling pathways shared with reactive oxygen species (ROS) and the second messenger Ca2+. Understanding of the subtle cross-talks operating between these signals was greatly improved by the recent identification and the functional analysis of proteins regulated through S-nitrosylation, a major NO-dependent post-translational protein modification. Overall, these findings suggest that NO is probably an important component of the mechanism coordinating and regulating Ca2+ and ROS signaling in plant immunity. (C) 2014 Elsevier Ltd. All rights reserved

    Is sperm FISH analysis still useful for Robertsonian translocations? Meiotic analysis for 23 patients and review of the literature

    No full text
    Résumé Contexte Le mode de ségrégation chromosomique le plus fréquemment observé chez les patients porteurs de translocation robertsonienne est. un mode équilibré. Les données semblent varier peu selon la translocation analysée. La relative constance des résultats dans le cas de ces translocations robertsoniennes rend elle inutile ces analyses chromosomiques pour ces patients? Patients et méthodes Nous avons analysé de façon rétrospective les données spermatiques et de ségrégation méiotique de 23 patients porteurs de translocation robertsonienne, de 2003 à 2017 et comparé les résultats observés à ceux décrits dans la littérature pour 187 patients. Résultats Le mode de ségrégation alterne est. prépondérant dans notre série de patients avec 73.45% ±8.05 de spermatozoïdes équilibrés (min 50.92%; max 89.99%). Ces résultats sont en accord avec les données de la littérature, toutes translocations confondues et selon le type de translocation (p > 0.05) sauf pour la translocation der(13;15) où ces taux sont significativement plus faibles (p < 0.05 vs der(13;14), der(14;21), (13;21) et der(15;22)). Nous observons également des taux de spermatozoïdes équilibrés significativement plus élevés chez les patients à spermogramme normal (p < 0.01). Conclusions Les différences observées dans les taux d’aneuploïdies entre les translocations der(13;15) et les autres translocations robertsoniennes et entre les porteurs de translocation à spermogramme normal ou altéré, et l’utilité de ces données dans le conseil génétique conduisent à poursuivre l’analyse systématique de la ségrégation méiotique pour les patients porteurs de translocations robertsoniennes et ceci particulièrement pour les translocations rares
    corecore