Low Rate of CMV End-Organ Disease in HIV-Infected Patients Despite Low CD4+ Cell Counts and CMV Viremia: Results of ACTG Protocol A5030

To describe cytomegalovirus (CMV) end-organ disease (EOD) rate in AIDS patients with low CD4+ cell count despite HAART who were enrolled in a randomized, placebo-controlled trial of preemptive valganciclovir (VGCV) to prevent CMV EOD in those with CMV viremia

Integrated Proteomic and Transcriptomic Investigation of the Acetaminophen Toxicity in Liver Microfluidic Biochip

Microfluidic bioartificial organs allow the reproduction of in vivo-like properties such as cell culture in a 3D dynamical micro environment. In this work, we established a method and a protocol for performing a toxicogenomic analysis of HepG2/C3A cultivated in a microfluidic biochip. Transcriptomic and proteomic analyses have shown the induction of the NRF2 pathway and the related drug metabolism pathways when the HepG2/C3A cells were cultivated in the biochip. The induction of those pathways in the biochip enhanced the metabolism of the N-acetyl-p-aminophenol drug (acetaminophen-APAP) when compared to Petri cultures. Thus, we observed 50% growth inhibition of cell proliferation at 1 mM in the biochip, which appeared similar to human plasmatic toxic concentrations reported at 2 mM. The metabolic signature of APAP toxicity in the biochip showed similar biomarkers as those reported in vivo, such as the calcium homeostasis, lipid metabolism and reorganization of the cytoskeleton, at the transcriptome and proteome levels (which was not the case in Petri dishes). These results demonstrate a specific molecular signature for acetaminophen at transcriptomic and proteomic levels closed to situations found in vivo. Interestingly, a common component of the signature of the APAP molecule was identified in Petri and biochip cultures via the perturbations of the DNA replication and cell cycle. These findings provide an important insight into the use of microfluidic biochips as new tools in biomarker research in pharmaceutical drug studies and predictive toxicity investigations

Nuclear Translocation of β-Catenin during Mesenchymal Stem Cells Differentiation into Hepatocytes Is Associated with a Tumoral Phenotype

Wnt/β-catenin pathway controls biochemical processes related to cell differentiation. In committed cells the alteration of this pathway has been associated with tumors as hepatocellular carcinoma or hepatoblastoma. The present study evaluated the role of Wnt/β-catenin activation during human mesenchymal stem cells differentiation into hepatocytes. The differentiation to hepatocytes was achieved by the addition of two different conditioned media. In one of them, β-catenin nuclear translocation, up-regulation of genes related to the Wnt/β-catenin pathway, such as Lrp5 and Fzd3, as well as the oncogenes c-myc and p53 were observed. While in the other protocol there was a Wnt/β-catenin inactivation. Hepatocytes with nuclear translocation of β-catenin also had abnormal cellular proliferation, and expressed membrane proteins involved in hepatocellular carcinoma, metastatic behavior and cancer stem cells. Further, these cells had also increased auto-renewal capability as shown in spheroids formation assay. Comparison of both differentiation protocols by 2D-DIGE proteomic analysis revealed differential expression of 11 proteins with altered expression in hepatocellular carcinoma. Cathepsin B and D, adenine phosphoribosyltransferase, triosephosphate isomerase, inorganic pyrophosphatase, peptidyl-prolyl cis-trans isomerase A or lactate dehydrogenase β-chain were up-regulated only with the protocol associated with Wnt signaling activation while other proteins involved in tumor suppression, such as transgelin or tropomyosin β-chain were down-regulated in this protocol. In conclusion, our results suggest that activation of the Wnt/β-catenin pathway during human mesenchymal stem cells differentiation into hepatocytes is associated with a tumoral phenotype

Expression of the Dystrophin Gene in Cultured Fibroblasts

International audienceThe dystrophin whose defect is responsible for Duchenne and Becker muscular dystrophies is present in muscle, brain and cerebellum. We describe here the detection of dystrophin in human cultured skin fibroblasts, L809 cells and murine 3T6 cell line. Dystrophin transcripts initiated at the muscle specific first exon can also be amplified by cDNA-PCR from various fibroblastic cells. The expression of the dystrophin gene in fibroblasts could account for some abnormalities observed in patient's fibroblast cultures

Adénopathies cervicales métastasiques d'un carcinome épidermoïde sans primitif retrouvé (étude rétrospective de 30 cas)

La prise en charge des adénopathies cervicales métastatiques d'un carcinome épidermoïde occulte, qui représentent seulement 3% de la carcinologie cervico faciale, ne fait actuellement pas l'objet d'un consensus malgré de nombreuses publications. A partir d'une étude rétrospective de 30 cas pris en charge entre 1995 et 2006, nous avons voulu préciser la démarche diagnostique, les facteurs pronostiques et la stratégie thérapeutique, en confrontant nos résultats avec ceux de la littérature. L'étude histologique des pièces d'amygdalectomie est plus fiable que de simples biopsies. Elle montre une prévalence accrue, de l'ordre de 30%, des tumeurs amygdaliennes occultes par rapport aux données antérieures. Le retentissement thérapeutique de l'identification d'une tumeur primitive justifie la réalisation systématique de ce geste dans le bilan initial, de façon au moins ipsilatérale à l'adénopathie cervicale et idéalement bilatérale. L'imagerie par TEP-TDM doit compléter le bilan initial, avant l'endoscopie, tant pour la mise en évidence d'une tumeur primitive que pour le bilan d'extension. Sa valeur pronostique et son apport dans l'évaluation d'une poursuite évolutive ganglionnaire ne sont pas encore clairement définis. La stratégie thérapeutique comporte une chirurgie première, complétée d'une irradiation cervicale en cas de facteurs pronostiques péjoratifs : un stade ganglionnaire avancé, la fixité de l'adénopathie et classiquement une rupture capsulaire. Pour les stades précoces (N1 et N2a), un traitement unique (curage cervical ou radiothérapie) est proposé par certains. La place de la chimiothérapie n'est à ce jour pas définie, nous la réalisons en présence de facteurs pronostiques péjoratifs. Aucun traitement n'a fait la preuve de son efficacité sur l'apparition de métastases viscérales à distance, qui conditionne, avec la récidive locorégionale, le pronostic de ces patients et justifie leur surveillance prolongée.ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Growth and differentiation of C2 myogenic cells are dependent on serum response factor.

In order to study to what extent and at which stage serum response factor (SRF) is indispensable for myogenesis, we stably transfected C2 myogenic cells with, successively, a glucocorticoid receptor expression vector and a construct allowing for the expression of an SRF antisense RNA under the direction of the mouse mammary tumor virus long terminal repeat. In the clones obtained, SRF synthesis is reversibly down-regulated by induction of SRF antisense RNA expression by dexamethasone, whose effect is antagonized by the anti-hormone RU486. Two kinds of proliferation and differentiation patterns have been obtained in the resulting clones. Some clones with a high level of constitutive SRF antisense RNA expression are unable to differentiate into myotubes; their growth can be blocked by further induction of SRF antisense RNA expression by dexamethasone. Other clones are able to differentiate and are able to synthesize SRF, MyoD, myogenin, and myosin heavy chain at confluency. When SRF antisense RNA expression is induced in proliferating myoblasts by dexamethasone treatment, cell growth is blocked and cyclin A concentration drops. When SRF antisense RNA synthesis is induced in arrested confluent myoblasts cultured in a differentiation medium, cell fusion is blocked and synthesis of not only SRF but also MyoD, myogenin, and myosin heavy chain is inhibited. Our results show, therefore, that SRF synthesis is indispensable for both myoblast proliferation and myogenic differentiation

Distal transcript of the dystrophin gene initiated from an alternative first exon and encoding a 75-kDa protein widely distributed in nonmuscle tissues.

A transcript generated by the distal part of the Duchenne Muscular Dystrophy (DMD) gene was initially detected in cells where the full size 14-kilobase (kb) messenger RNA is not found at a significant level. This transcript, approximately 4.5 kb long, corresponds to the cysteine-rich and carboxyl-terminal domains of dystrophin. It begins with a novel 80- to 100-nucleotide exon containing an ATG start site for a new coding sequence of 17 nucleotides in-frame with the consecutive dystrophin cDNA sequence from exon 63. This result suggests the existence of a third promoter that would be localized about 8 kilobases upstream from exon 63 of the DMD gene. The distal transcript is widely distributed but is absent in adult skeletal and myometrial muscle. It is much more abundant in fetal tissues. With an antibody directed against the dystrophin carboxyl terminus, the protein corresponding to this transcript was detected as a 70- to 75-kDa entity on Western blots. It was found in all tissues analyzed except in skeletal muscle. It was not found in lymphoblastoid cells from a Duchenne patient with a complete deletion of the dystrophin gene. The role and subcellular localization of this protein is not known. It may explain extramuscular symptoms exhibited by some Duchenne patients