370 research outputs found

    3D fluorescent in situ hybridization using Arabidopsis leaf cryosections and isolated nuclei

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    Background: Fluorescent hybridization techniques are widely used to study the functional organization of different compartments within the mammalian nucleus. However, few examples of such studies are known in the plant kingdom. Indeed, preservation of nuclei 3D structure, which is required for nuclear organization studies, is difficult to fulfill. Results: We report a rapid protocol for fluorescent in situ hybridization (FISH) performed on 3D isolated nuclei and thin cryosectioned leaves of Arabidopsis thaliana. The use of direct labeling minimized treatment steps, shortening the overall procedure. Using image analysis, we measured different parameters related to nucleus morphology and overall 3D structure. Conclusion: Our work describes a 3D-FISH protocol that preserves the 3D structure of Arabidopsis interphase nuclei. Moreover, we report for the first time FISH using cryosections of Arabidopsis leaves. This protocol is a valuable tool to investigate nuclear architecture and chromatin organization

    Financement des universités : pour un SYstème de répartition des Moyens à l\u27Activité et à la Performance (SYMPA) (le)

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    Sénat - Rapport d\u27information n° 382 (2007-2008) du 10 juin 2008 - par MM. Philippe ADNOT, Jean-Léonce DUPONT, Christian GAUDIN, Serge LAGAUCHE, Gérard LONGUET et Philippe RICHERT, fait au nom de la commission des Affaires culturelles et de la commission des Finances, du contrôle budgétaire et des comptes économiques de la Natio

    A 1-year case-control study in patients with rheumatoid arthritis indicates prevention of loss of bone mineral density in both responders and nonresponders to infliximab

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    The goal of the present study was to record changes in bone mineral density (BMD) and markers of bone turnover in patients with rheumatoid arthritis (RA) who were treated with methotrexate combined (or not combined) with infliximab. Included were 90 patients with RA who required anti-TNF-α therapy with infliximab because of persistent active disease despite treatment with methotrexate. The historical control group included 99 patients with RA who were treated with methotrexate at a time when anti-TNF-α treatment was not yet available. Lumbar and femoral neck BMD was measured using dual energy X-ray absorptiometry at baseline and 1 year later. Osteocalcin, C-terminal cross-linked telopeptide of type I collagen, parathyroid hormone and 25-hydroxycholecalciferol were measured in plasma at baseline and 1 year later. At 1 year BMD had decreased in the control group at spine (P < 0.01) and femoral neck (P < 0.001). In contrast, BMD at spine and femoral neck did not change after 1 year of infliximab treatment. At the same time point, no change in bone remodelling markers was observed. No association was observed between clinical response and changes in BMD, indicating that even those who did not respond clinically did not lose bone over a 1-year period. These data confirm the BMD decrease observed in RA patients treated with methotrexate alone. This bone loss was prevented by infliximab therapy. Importantly, this beneficial effect was also observed in apparent nonresponders

    Residual HIV-1 DNA Flap-independent nuclear import of cPPT/CTS double mutant viruses does not support spreading infection

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    <p>Abstract</p> <p>Background</p> <p>The human immunodeficiency virus type 1 (HIV-1) central DNA Flap is generated during reverse transcription as a result of (+) strand initiation at the central polypurine tract (cPPT) and termination after a <it>ca</it>. 100 bp strand displacement at the central termination sequence (CTS). The central DNA Flap is a determinant of HIV-1 nuclear import, however, neither cPPT nor CTS mutations entirely abolish nuclear import and infection. Therefore, to determine whether or not the DNA Flap is essential for HIV-1 nuclear import, we generated double mutant (DM) viruses, combining cPPT and CTS mutations to abolish DNA Flap formation.</p> <p>Results</p> <p>The combination of cPPT and CTS mutations reduced the proportion of viruses forming the central DNA Flap at the end of reverse transcription and further decreased virus infectivity in one-cycle titration assays. The most affected DM viruses were unable to establish a spreading infection in the highly permissive MT4 cell line, nor in human primary peripheral blood mononuclear cells (PBMCs), indicating that the DNA Flap is required for virus replication. Surprisingly, we found that DM viruses still maintained residual nuclear import levels, amounting to 5-15% of wild-type virus, as assessed by viral DNA circle quantification. Alu-PCR quantification of integrated viral genome also indicated 5-10% residual integration levels compared to wild-type virus.</p> <p>Conclusion</p> <p>This work establishes that the central DNA Flap is required for HIV-1 spreading infection but points to a residual DNA Flap independent nuclear import, whose functional significance remains unclear since it is not sufficient to support viral replication.</p

    Outcome of alimentary tract duplications operated on by minimally invasive surgery: a retrospective multicenter study by the GECI (Groupe d&#039;Etude en Coeliochirurgie Infantile).

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    BACKGROUND: Alimentary tract duplications (ATD) are a rare cause of intestinal obstruction in childhood. There are many case reports but few series about laparoscopy or thoracoscopy for ATD. The aim of our study was to report the outcome of minimally invasive surgery (MIS) for ATD. METHODS: This was a retrospective multicenter study from the GECI (Groupe d\u27Etude en Coeliochirurgie Infantile). We reviewed the charts of 114 patients operated on by MIS for ATD from 1994 to 2009. RESULTS: Sixty-two patients (54 %) had a prenatal diagnosis. Forty-nine patients (43 %) were symptomatic before surgery: 33 of those patients (63 %) with postnatal diagnosis compared to 16 (25 %) with prenatal diagnosis (P &lt; 0.01). In this last group, the median age at onset of symptoms was 16 days (range = 0-972). One hundred and two patients had laparoscopy (esophageal to rectal duplications) and 12 patients had thoracoscopy for esophageal duplications. The mean operative time was 90 min (range = 82-98). There were 32 (28 %) resection anastomoses, 55 (48 %) enucleations, and 27 (24 %) unroofings. The conversion rate was 32 %, and in a multivariate analysis, it was significantly higher, up to 41 % for patients weighing &lt;10 kg (P &lt; 0.01). Ten patients (8 %) had unintentional perioperative opening of the digestive tract during the dissection. Eight patients had nine postoperative complications, including six small bowel obstructions. The median length of hospital stay was 4 days (range = 1-21) without conversion and 6 days (range = 1-27) with conversion (P = 0.01). The median follow-up was 3 months (range = 1-120). Eighteen of the 27 patients who underwent partial surgery had an ultrasound examination during follow-up. Five (18 %) of them had macroscopic residue. CONCLUSION: This study showed that MIS for ATD is feasible with a low rate of complications. Patients with prenatal diagnosis should have prompt surgery to prevent symptoms, despite a high rate of conversion in small infants

    Online Training on Skin Cancer Diagnosis in Rheumatologists: Results from a Nationwide Randomized Web-Based Survey

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    International audiencePatients with inflammatory rheumatisms, such as rheumatoid arthritis, are more prone to develop skin cancers than the general population, with an additional increased incidence when receiving TNF blockers. There is therefore a need that physicians treating patients affected with inflammatory rheumatisms with TNF blockers recognize malignant skin lesions, requiring an urgent referral to the dermatologist and a potential withdrawal or modification of the immunomodulatory treatment. We aimed to demonstrate that an online training dedicated to skin tumors increase the abilities of rheumatologists to discriminate skin cancers from benign skin tumors. A nationwide randomized web-based survey involving 141 French rheumatologists was conducted. The baseline evaluation included short cases with skin lesion pictures and multiple choice questions assessing basic knowledge on skin cancers. For each case, rheumatologists had to indicate the nature of skin lesion (benign; premalignant/ malignant), their level of confidence in this diagnosis (10-points Likert scale), and the precise dermatological diagnosis among 5 propositions. Different scores were established. After randomization, only one group had access to the online formation consisting in 4 elearning modules on skin tumors, of 15 minutes each (online training group). After reevaluation, the trained and the non-trained group (control group) were compared. The primary end-point was the number of adequate diagnoses of the nature of the skin lesions. The mean number of adequate diagnosis for the benign versus premalignant/malignant nature of the lesions was higher in the online training group (13.4 vs. 11.2 points; p value <0.0001). While the other knowledge scores were also significantly higher, no statistical difference was observed on the level of self-confidence between the 2 groups. In conclusion, the online formation was effective to improve the rheumatologists' ability to diagnose skin cancer

    Bilan et perspectives des deux écoles techniques « notions et techniques en écologie » organisées par le Département EFPA

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    La création du Département «Écologie des Forêts, Prairies et milieux Aquatiques» a suscité de la part des personnels techniques concernés une volonté d’intégration collective sous le concept fédérateur de l’écologie. Pour cela deux écoles techniques ont été organisées sur des notions et méthodes d’écologie par un Comité de pilotage composé de techniciens et de scientifiques. L’objectif visait à familiariser les techniciens aux concepts de l’écologie et à les aider à se situer dans les thématiques de recherche du Département EFPA. Enfin, il s’agissait d’instaurer une communauté de pratique autour de l’écologie. Ces écoles ont rassemblé 79 personnes, en proposant visites sur le terrain et séances en salle. Deux animations ont particulièrement été appréciées, l’une sous forme d’un jeu en préambule, l’autre sous forme de présentations par des binômes techniciens/chercheurs. Les participants sont plutôt convaincus d’avoir progressé sur les notions en écologie et ils ont la volonté d’aller plus loin avec la création d’un Réseau de Technicien en Ecologie (RTE), la mise en place d’une liste de diffusion et l’organisation régulière de rencontres entre membres du réseau
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