169 research outputs found
Does combined posterior cruciate ligament and posterolateral corner reconstruction for chronic posterior and posterolateral instability restore normal knee function?
SummaryIntroductionPosterior cruciate ligament (PCL) injuries are frequently associated with posterolateral corner (PLC) damages. These complex lesions are most often poorly tolerated clinically. Adherence to sound biomechanical principles treating these complex lesions entails obtaining a functional PCL and reconstructing sufficient posterolateral stability.HypothesisSurgical treatment of postero-posterolateral laxity (PPLL) re-establishes sufficient anatomical integrity to provide stability and satisfactory knee function.Material and methodsIn this retrospective, continuous, single-operator study, 21 patients were operated for chronic PPLL with combined reconstruction of the PCL and PLC and were reviewed with a minimum 1 year follow-up. The clinical and subjective outcomes were evaluated using the IKDC score. Surgical correction of posterior laxity was quantified clinically and radiologically on dynamic posterior drawer images (posterior Telos™ stress test and hamstrings contraction lateral view).ResultsThe mean subjective IKDC score was 62.8 at the last follow-up versus a preoperative score of 54.5 (NS). Preoperatively, all were classified in groups C and D. Postoperatively, 13 patients out of 21 were classified in groups A and B according to the overall clinical IKDC score. The radiological gain in laxity was 51% on the hamstring contraction films and 67% on the posterior Telos™ images (p<0.05).DiscussionThe objective of surgical treatment is to re-establish anatomical integrity to the greatest possible extent. The clinical and radiological laxity results are disappointing in terms of the objectives but are in agreement with the literature. The subjective evaluation demonstrated that this operation can provide sufficient function for standard daily activities but not sports activities.Level of evidenceLevel IV retrospective study
Codon repeats in genes associated with human diseases: fewer repeats in the genes of nonhuman primates and nucleotide substitutions concentrated at the sites of reiteration.
Evaluation expérimentale de stratégies de déploiement de gènes de résistance pour la gestion durable des nématodes à galles
Dans le cadre de projets soutenus par l'ANR Systerra et le GIS PICLeg (projets "Sysbiotel" et "Neoleg") menés en collaboration entre l'INRA PACA, l'IRD, l'APREL, la Chambre d'Agriculture du 06 et des entreprises privées de sélection de semences, plusieurs stratégies de déploiement de gènes de résistance ont été évaluées pendant 3 ans sur le terrain en conditions agronomiques pour mettre au point une gestion raisonnée des cultivars résistants permettant de gérer de manière durable les problèmes de nématodes à galles des racines. L'alternance des gènes de résistance dans la rotation et le "pyramiding" de gènes dans un même cultivar se sont révélés extrêmement efficaces pour supprimer l'émergence de populations virulentes et réduire les taux d'infestation du sol de plus de 80% en 3 ans. Un nouveau projet INRA "Gedunem", mis en place dans le cadre du Métaprogramme INRA SMaCH (Sustainable Management of Crop Health), vise maintenant à associer ces innovations variétales aux autres méthodes de lutte disponibles (gestion de l'interculture, plantes non hôtes, prophylaxie) afin de maintenir une pression parasitaire faible, tout en évaluant ces nouveaux systèmes de culture du point de vue agronomique et socio-économique
Control of Gene Expression by the Retinoic Acid-Related Orphan Receptor Alpha in HepG2 Human Hepatoma Cells
Retinoic acid-related Orphan Receptor alpha (RORα; NR1F1) is a widely distributed nuclear receptor involved in several (patho)physiological functions including lipid metabolism, inflammation, angiogenesis, and circadian rhythm. To better understand the role of this nuclear receptor in liver, we aimed at displaying genes controlled by RORα in liver cells by generating HepG2 human hepatoma cells stably over-expressing RORα. Genes whose expression was altered in these cells versus control cells were displayed using micro-arrays followed by qRT-PCR analysis. Expression of these genes was also altered in cells in which RORα was transiently over-expressed after adenoviral infection. A number of the genes found were involved in known pathways controlled by RORα, for instance LPA, NR1D2 and ADIPOQ in lipid metabolism, ADIPOQ and PLG in inflammation, PLG in fibrinolysis and NR1D2 and NR1D1 in circadian rhythm. This study also revealed that genes such as G6PC, involved in glucose homeostasis, and AGRP, involved in the control of body weight, are also controlled by RORα. Lastly, SPARC, involved in cell growth and adhesion, and associated with liver carcinogenesis, was up-regulated by RORα. SPARC was found to be a new putative RORα target gene since it possesses, in its promoter, a functional RORE as evidenced by EMSAs and transfection experiments. Most of the other genes that we found regulated by RORα also contained putative ROREs in their regulatory regions. Chromatin immunoprecipitation (ChIP) confirmed that the ROREs present in the SPARC, PLG, G6PC, NR1D2 and AGRP genes were occupied by RORα in HepG2 cells. Therefore these genes must now be considered as direct RORα targets. Our results open new routes on the roles of RORα in glucose metabolism and carcinogenesis within cells of hepatic origin
Impact of Reference Gene Selection for Target Gene Normalization on Experimental Outcome Using Real-Time qRT-PCR in Adipocytes
Background: With the current rise in obesity-related morbidities, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) has become a widely used method for assessment of genes expressed and regulated by adipocytes. In order to measure accurate changes in relative gene expression and monitor intersample variability, normalization to endogenous control genes that do not change in relative expression is commonly used with qRT-PCR determinations. However, historical evidence has clearly demonstrated that the expression profiles of traditional control genes (e.g., b-actin, GAPDH, a-tubulin) are differentially regulated across multiple tissue types and experimental conditions. Methodology/Principal Findings: Therefore, we validated six commonly used endogenous control genes under diverse experimental conditions of inflammatory stress, oxidative stress, synchronous cell cycle progression and cellular differentiation in 3T3-L1 adipocytes using TaqMan qRT-PCR. Under each study condition, we further evaluated the impact of reference gene selection on experimental outcome using examples of target genes relevant to adipocyte function and differentiation. We demonstrate that multiple reference genes are regulated in a condition-specific manner that is not suitable for use in target gene normalization. Conclusion/Significance: Data are presented demonstrating that inappropriate reference gene selection can have profound influence on study conclusions ranging from divergent statistical outcome to inaccurate data interpretation of significan
Tissue-specific splicing factor gene expression signatures
The alternative splicing code that controls and coordinates the transcriptome in complex multicellular organisms remains poorly understood. It has long been argued that regulation of alternative splicing relies on combinatorial interactions between multiple proteins, and that tissue-specific splicing decisions most likely result from differences in the concentration and/or activity of these proteins. However, large-scale data to systematically address this issue have just recently started to become available. Here we show that splicing factor gene expression signatures can be identified that reflect cell type and tissue-specific patterns of alternative splicing. We used a computational approach to analyze microarray-based gene expression profiles of splicing factors from mouse, chimpanzee and human tissues. Our results show that brain and testis, the two tissues with highest levels of alternative splicing events, have the largest number of splicing factor genes that are most highly differentially expressed. We further identified SR protein kinases and small nuclear ribonucleoprotein particle (snRNP) proteins among the splicing factor genes that are most highly differentially expressed in a particular tissue. These results indicate the power of generating signature-based predictions as an initial computational approach into a global view of tissue-specific alternative splicing regulation
Epidermal Transglutaminase (TGase 3) Is Required for Proper Hair Development, but Not the Formation of the Epidermal Barrier
Transglutaminases (TGase), a family of cross-linking enzymes present in most cell types, are important in events as diverse as cell-signaling and matrix stabilization. Transglutaminase 1 is crucial in developing the epidermal barrier, however the skin also contains other family members, in particular TGase 3. This isoform is highly expressed in the cornified layer, where it is believed to stabilize the epidermis and its reduction is implicated in psoriasis. To understand the importance of TGase 3 in vivo we have generated and analyzed mice lacking this protein. Surprisingly, these animals display no obvious defect in skin development, no overt changes in barrier function or ability to heal wounds. In contrast, hair lacking TGase 3 is thinner, has major alterations in the cuticle cells and hair protein cross-linking is markedly decreased. Apparently, while TGase 3 is of unique functional importance in hair, in the epidermis loss of TGase 3 can be compensated for by other family members
Effect of tissue-harvesting site on yield of stem cells derived from adipose tissue: implications for cell-based therapies
The stromal vascular fraction (SVF) of adipose tissue contains an abundant population of multipotent adipose-tissue-derived stem cells (ASCs) that possess the capacity to differentiate into cells of the mesodermal lineage in vitro. For cell-based therapies, an advantageous approach would be to harvest these SVF cells and give them back to the patient within a single surgical procedure, thereby avoiding lengthy and costly in vitro culturing steps. However, this requires SVF-isolates to contain sufficient ASCs capable of differentiating into the desired cell lineage. We have investigated whether the yield and function of ASCs are affected by the anatomical sites most frequently used for harvesting adipose tissue: the abdomen and hip/thigh region. The frequency of ASCs in the SVF of adipose tissue from the abdomen and hip/thigh region was determined in limiting dilution and colony-forming unit (CFU) assays. The capacity of these ASCs to differentiate into the chondrogenic and osteogenic pathways was investigated by quantitative real-time polymerase chain reaction and (immuno)histochemistry. A significant difference (P = 0.0009) was seen in ASC frequency but not in the absolute number of nucleated cells between adipose tissue harvested from the abdomen (5.1 ± 1.1%, mean ± SEM) and hip/thigh region (1.2 ± 0.7%). However, within the CFUs derived from both tissues, the frequency of CFUs having osteogenic differentiation potential was the same. When cultured, homogeneous cell populations were obtained with similar growth kinetics and phenotype. No differences were detected in differentiation capacity between ASCs from both tissue-harvesting sites. We conclude that the yield of ASCs, but not the total amount of nucleated cells per volume or the ASC proliferation and differentiation capacities, are dependent on the tissue-harvesting site. The abdomen seems to be preferable to the hip/thigh region for harvesting adipose tissue, in particular when considering SVF cells for stem-cell-based therapies in one-step surgical procedures for skeletal tissue engineering
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