528 research outputs found
N011 Culture et délivrance au niveau du tissu cardiaque de cardiomyocytes issus de cellules souches embryonnaires humaines au moyen de matrices tridimensionelles poreuses à base de polysaccharides
Un intĂ©rĂȘt particulier a Ă©tĂ© portĂ© ces derniĂšres annĂ©es Ă la thĂ©rapie cellulaire rĂ©paratrice cardiaque. Les cellules souches embryonnaires humaines (hES) sont une source prouvĂ©e de cardiomyocytes et les premiĂšres donnĂ©es in vivo suggĂšrent leurs capacitĂ©s fonctionnelles Ă type dâeffet pacemaker ou rĂ©paratrices dâinfarctus du myocarde. Nous avons Ă©tudiĂ© un mode de dĂ©livrance des cellules hES dans le tissu cardiaque basĂ© sur une matrice 3D servant de support Ă la fois pour la culture des cellules et pour leur implantation au contact du myocarde.Des matrices poreuses de polysaccharides (pullulane et dextrane) ont Ă©tĂ© prĂ©parĂ©es par rĂ©ticulation chimique permettant de rĂ©aliser des films avec des pores de 100 Ă 200 microns. Les matrices ont Ă©tĂ© recouvertes de diffĂ©rentes protĂ©ines; les cellules hES indiffĂ©renciĂ©es ont Ă©tĂ© cultivĂ©es sur fibroblastes murins, en milieu supplĂ©mentĂ© avec du sĂ©rum knock-out et du FGF2. Dans une premiĂšre partie in vitro, nous avons mis en Ă©vidence par q-RT-PCR, observation microscopique et imagerie confocale, la diffĂ©renciation en cardiomyocytes de cellules hES directement cultivĂ©es dans les matrices en prĂ©sence dâun milieu inducteur de diffĂ©rentiation; les matrices permettaient aussi la culture, lâexpansion et la survie Ă long terme de parties battantes obtenues Ă partir de corps embryoĂŻdes issus dâhES et isolĂ©es manuellement. Nous avons ensuite Ă©tudiĂ© le devenir des cellules hES dans un modĂšle de lĂ©sions cardiaques par dĂ©pĂŽt de films poreux cellularisĂ©s sur les cĆurs infarcis de souris NOD SCID. Lâidentification est confirmĂ©e pour les cardiomyocytes issus dâES dâune lignĂ©e de cellules hES H9 GFP+ ainsi que dâune lignĂ©e de cellules hES dans laquelle lâexpression de la GFP est sous contrĂŽle dâun promoteur spĂ©cifique du tissu cardiaque, Nkx2.5. Nous avons ainsi mis en Ă©vidence la migration des cellules ES Ă diffĂ©rents stades de diffĂ©renciation Ă partir des matrices 3D vers les souris NOD SCID ainsi que leur diffĂ©renciation en cardiomyocytes. Les donnĂ©es de PCR quantitative sur la base du transgĂšne GFP mettent en Ă©vidence une meilleure survie des ES dĂ©livrĂ©es par lâintermĂ©diaire des matrices 3D en comparaison avec une administration directe. Une Ă©tude fonctionnelle comparative est en cours
Séparation et spéciation des éléments dans des échantillons nucléaires par couplage entre l'électrophorÚse capillaire et la spectrométrie de masse à source plasma et à multicollection
International audienceLa dĂ©termination prĂ©cise des compositions Ă©lĂ©mentaires et isotopiques dans des Ă©chantillons nuclĂ©aires est indispensable pour la gestion des combustibles nuclĂ©aires et des dĂ©chets radioactifs. Cette dĂ©termination isotopique et Ă©lĂ©mentaire porte notamment sur l'uranium, le plutonium et les lanthanides et est effectuĂ©e par spectromĂ©trie de masse aprĂšs sĂ©parations chimiques afin dâĂ©liminer les interfĂ©rences isobariques. L'ĂlectrophorĂšse capillaire est une technique sĂ©parative particuliĂšrement attractive pour ces applications, du fait des trĂšs hautes efficacitĂ©s, des courts temps d'analyse et des micro volumes mis en jeu. Des Ă©tudes menĂ©es prĂ©cĂ©demment au laboratoire ont dĂ©montrĂ© la faisabilitĂ© de sĂ©parations U/Pu/Lanthanides et de sĂ©parations U/Th en utilisant un Ă©lectrolyte d'acide acĂ©tique et en couplage direct avec un spectromĂštre de masse Multi-collecteurs a source plasma. La complexitĂ© et la diversitĂ© des Ă©chantillons nuclĂ©aires imposent un suivi de la spĂ©ciation des Ă©lĂ©ments dâintĂ©rĂȘts dans les conditions dĂ©veloppĂ©es afin de garantir le succĂšs des analyses. LâĂ©tude de spĂ©ciation qui sera prĂ©sentĂ©e ici a permis d'expliquer les facteurs influençant le comportement Ă©lectro-optique des Ă©lĂ©ments dâintĂ©rĂȘt. Ces Ă©tudes de spĂ©ciation peuvent ĂȘtre Ă©tendues a d'autres Ă©lectrolytes afin de dĂ©velopper des sĂ©parations pour les Ă©lĂ©ments prĂ©sents dans les Ă©chantillons nuclĂ©aires
Long term surgical results of 154 petroclival meningiomas: A retrospective multicenter study
BACKGROUND: Outcomes of petroclival meningiomas (PCM) (morbidity, permanent cranial nerves deficit, tumor removal and recurrence) are inconsistent in the literature, making it a challenge to predict surgical morbidity.
METHODS: A multicenter study of patients with PCMs larger than 2.5cm between 1984 and 2017 was conducted. The authors retrospectively reviewed the patients\u27 medical records, imaging studies and pathology reports to analyze presentation, surgical approach, neurological outcomes, complications, recurrence rates and predictive factors.
RESULTS: There were 154 patients. The follow-up was 76.8 months on average (range 8-380 months). Gross total resection (GTR) was achieved in 40 (26.0%) patients, subtotal resection (STR) in 101 (65.6%), and partial resection in 13 (8.3%). Six (2.6%) perioperative deaths occurred. The 5-year, 10-year and 15-year progression-free survival (PFS) of GTR and STR with radiation therapy (RT) was similar (100%, 90% and 75%). PFS of STR without adjuvant radiation was associated with progression in 71%, 51% and 31%, respectively. Anterior petrosectomy and combined petrosectomy were associated with higher postoperative CN V and CN VI deficits compared to the retrosigmoid approach. The latter had a significantly higher risk of CN VII, CN VIII and LCN deficit. Temporal lobe dysfunction (seizure and aphasia) were significantly associated with the anterior petrosectomy approach.
CONCLUSIONS: Our study shows that optimal subtotal resection of PCMs associated with postoperative RT or stereotactic radiosurgery results in long-term tumor control to equivalent radical surgery. Case selection and appropriate intraoperative judgement are required to reduce the morbidity
Clinical applications of B-type natriuretic peptide (BNP) testing
Many claims have been made in recent years regarding the utility of plasma B-type natriuretic peptide (BNP) concentration measurements in the diagnosis, risk stratification and monitoring of patients with heart failure. This paper summarizes the current evidence and provides guidance for practising clinicians. Overall, plasma BNP testing appears to be of most value in the diagnostic arena, where it is likely to improve the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a ârule out' test for suspected cases of new heart failure in breathless patients presenting to either the outpatient or emergency care settings; it is not a replacement for echocardiography and full cardiological assessment, which will be required for patients with an elevated BNP concentration. Although work is ongoing in establishing the ânormal' values of BNP, heart failure appears to be highly unlikely below a plasma concentration of 100pg/ml. However, as BNP levels rise with age and are affected by gender, comorbidity and drug therapy, the plasma BNP measurement should not be used in isolation from the clinical contex
Rapport préliminaire sur les activités de la mission archéologique franco-syrienne dans la micro-région d'Al-Rawda (Shamiyeh) : quatriÚme et cinquiÚme campagnes (2005 et 2006)
This preliminary report presents the results of two campaigns of excavation and survey in 2005and 2006 on the site of AI-Rawda (West-Central Syria) and in the micro-region of 100 km2 around it. Thesite is a pre-planned circular new town. It was founded around 2400 BCE, in the steppe zone and was inhabitedonly during EB IV, until the end of the 3rd millennium. The work of 2005 and 2006 involved furtherextensive excavation of a sanctuary consisting of two temples and a temenos togeiher with aIl associatedinstallations (including a betyl in situ). The eastem gate of the town was excavated and four lines of defencehave been identified. A stratigraphie sounding in the southwest clarifies the origin of the town. In the necropolisassociated with the site, the excavation of a collective pit burial is presented. Intensive survey wascontinued outside the ancient town, with particular attention to sites that were occupied at the same time asAI-Rawda, to burials, which have been classified by type, and to installations that can be linked to agricultureor pastoralism. This work was supplemented by archaeobotanical, archaeozoological and geo-archaeologicalresearch, as weIl as a study of the environment.Ce rapport prĂ©liminaire prĂ©sente les rĂ©sultats de deux campagnes de fouilles et de prospection conduites en 2005 et 2006 sur le site dâAl-Rawda (Syrie du centre-ouest) et dans la microrĂ©gion de 100 km2 qui lâentoure. Le site, une ville neuve circulaire au plan dâurbanisme prĂ©conçu fondĂ© vers 2500 av. J.-C., se trouve en zone steppique. Il nâest habitĂ© que durant le Bronze ancien IV, jusquâĂ la fin du 3e millĂ©naire.Les travaux en 2005 et 2006 ont portĂ© sur la poursuite du dĂ©gagement extensif dâun sanctuaire qui regroupe deux temples et un temenos, avec lâensemble des installations quâils contiennent (dont un bĂ©tyle in situ). Ă lâest, a Ă©tĂ© mise au jour la porte orientale de la ville tandis que quatre lignes de dĂ©fense ont Ă©tĂ© identifiĂ©es. Un sondage stratigraphique au sud-ouest Ă©claire lâorigine de la ville. Dans la nĂ©cropole associĂ©e au site, la fouille dâune tombe en puits collective est prĂ©sentĂ©e.ParallĂšlement, la prospection intensive autour de la ville antique a Ă©tĂ© poursuivie en mettant lâaccent sur les sites dâhabitat contemporains dâAl-Rawda, les tombes caractĂ©risĂ©es par type et les amĂ©nagements qui peuvent ĂȘtre liĂ©s Ă une mise en valeur agricole du territoire et au pastoralisme. Ces travaux ont Ă©tĂ© complĂ©tĂ©s par des Ă©tudes archĂ©obotanique, archĂ©ozoologique, gĂ©oarchĂ©ologique et par une Ă©tude des milieux
Stuttered swallowing: Electric stimulation of the right insula interferes with water swallowing. A case report
<p>Abstract</p> <p>Background</p> <p>Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear.</p> <p>Case presentation</p> <p>Invasive electroencephalographic monitoring was performed in a 24-year-old man with medically intractable stereotyped nocturnal hypermotor seizures due to a ganglioglioma. During stimulation of the right inferior posterior insular cortex with depth electrodes the patient spontaneously reported a perception of a "stutter in swallowing". Stimulation of the inferior posterior insular cortex at highest intensity (4 mA) was also associated with irregular and delayed swallows. Swallowing was not impaired during stimulation of the superior posterior insular cortex, regardless of stimulation intensity.</p> <p>Conclusions</p> <p>These results indicate that the right inferior posterior insular cortex is involved in the neural circuitry underlying the control of swallowing.</p
Advances in heterometallic ring-opening (co)polymerisation catalysis
Truly sustainable plastics require renewable feedstocks coupled with efficient production and end-of-life degradation/recycling processes. Some of the most useful degradable materials are aliphatic polyesters, polycarbonates and polyamides, which are often prepared via ring-opening (co)polymerisation (RO(CO)P) using an organometallic catalyst. While there has been extensive research into ligand development, heterometallic cooperativity offers an equally promising yet underexplored strategy to improve catalyst performance, as heterometallic catalysts often exhibit significant activity and selectivity enhancements compared to their homometallic counterparts. This review describes advances in heterometallic RO(CO)P catalyst design, highlighting the overarching structure-activity trends and reactivity patterns to inform future catalyst design
Neuropsychological patterns following lesions of the anterior insula in a series of forty neurosurgical patients
In the present study we investigated the effects of lesions affecting mainly the anterior insula in a series of 22 patients with lesions in the left hemisphere (LH), and 18 patients with lesions involving the right hemisphere (RH). The site of the lesion was established by performing an overlap of the probabilistic cytoarchitectonic maps of the posterior insula. Here we report the patients\u2019 neuropsychological profile and an analysis of their pre-surgical symptoms. We found that pre-operatory symptoms significantly differed in patients depending on whether the lesion affected the right or left insula and a strict parallelism between the patterns emerged in the pre-surgery symptoms analysis, and the patients\u2019 cognitive profile. In particular, we found that LH patients showed cognitive deficits. By contrast, the RH patients, with the exception of one case showing an impaired performance at the visuo-spatial planning test were within the normal range in performing all the tests. In addition, a sub-group of patients underwent to the post-surgery follow-up examination
A Rapid Method for Measuring Strontium-90 Activity in Crops in China
A rapid method for measuring Sr-90 activity in crop ashes is presented. Liquid scintillation counting, combined with ion exchange columns 4â, 4â(5â)-di-t-butylcyclohexane-18-crown-6, is used to determine the activity of Sr-90 in crops. The yields of chemical procedure are quantified using gravimetric analysis. The conventional method that uses ion-exchange resin with HDEHP could not completely remove all the bismuth when comparatively large lead and bismuth exist in the samples. This is overcome by the rapid method. The chemical yield of this method is about 60% and the MDA for Sr-90 is found to be 2:32 Bq/kg. The whole procedure together with using spectrum analysis to determine the activity only takes about one day, which is really a large improvement compared with the conventional method. A modified conventional method is also described here to verify the value of the rapid one. These two methods can meet di_erent needs of daily monitoring and emergency situation
Physiological aspects of the determination of comprehensive arterial inflows in the lower abdomen assessed by Doppler ultrasound
Non-invasive measurement of splanchnic hemodynamics has been utilized in the clinical setting for diagnosis of gastro-intestinal disease, and for determining reserve blood flow (BF) distribution. However, previous studies that measured BF in a "single vessel with small size volume", such as the superior mesenteric and coeliac arteries, were concerned solely with the target organ in the gastrointestinal area, and therefore evaluation of alterations in these single arterial BFs under various states was sometimes limited to "small blood volumes", even though there was a relatively large change in flow. BF in the lower abdomen (BFAb) is potentially a useful indicator of the influence of comprehensive BF redistribution in cardiovascular and hepato-gastrointestinal disease, in the postprandial period, and in relation to physical exercise. BFAb can be determined theoretically using Doppler ultrasound by subtracting BF in the bilateral proximal femoral arteries (FAs) from BF in the upper abdominal aorta (Ao) above the coeliac trunk. Prior to acceptance of this method of determining a true BFAb value, it is necessary to obtain validated normal physiological data that represent the hemodynamic relationship between the three arteries. In determining BFAb, relative reliability was acceptably high (range in intra-class correlation coefficient: 0.85-0.97) for three arterial hemodynamic parameters (blood velocity, vessel diameter, and BF) in three repeated measurements obtained over three different days. Bland-Altman analysis of the three repeated measurements revealed that day-to-day physiological variation (potentially including measurement error) was within the acceptable minimum range (95% of confidence interval), calculated as the difference in hemodynamics between two measurements. Mean BF (ml/min) was 2951 ± 767 in Ao, 316 ± 97 in left FA, 313 ± 83 in right FA, and 2323 ± 703 in BFAb, which is in agreement with a previous study that measured the sum of BF in the major part of the coeliac, mesenteric, and renal arteries. This review presents the methodological concept that underlies BFAb, and aspects of its day-to-day relative reliability in terms of the hemodynamics of the three target arteries, relationship with body surface area, respiratory effects, and potential clinical usefulness and application, in relation to data previously reported in original dedicated research
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