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C Prudhomme

Publications and source records attributed to C Prudhomme.

9 recordsLinked to original sources
PubMed2001

NUDC expression during amphibian development.

To identify gene products important for gastrulation in the amphibian Pleurodeles waltl, a screen for regional differences in new protein expression at the early gastrula stage was performed. A 45 kDa protein whose synthesis was specific for progenitor endodermal cells was identified. Microsequencing and cDNA cloning showed that P45 is highly homologous to rat NUDC, a protein suggested to play a role in nuclear migration. Although PNUDC can be detected in all regions of the embryo, its de novo synthesis is tightly regulated spatially and temporally throughout oogenesis and embryonic development. New PNUDC synthesis in the progenitor endodermal cells depends on induction by the mesodermal cells in the gastrula. During development, PNUDC is localized in the egg cortical cytoplasm, at the cleavage furrow during the first embryonic division, around the nuclei and cortical regions of bottle cells in the gastrula, and at the basal region of polarized tissues in the developing embryo. These results show for the first time the expression and compartmentalization of PNUDC at distinct stages during amphibian development.

Amino Acid Sequence↗
PubMed1998

Cell-cycle-dependent nuclear translocation of HSP70 in amphibian embryonic cells.

Using immunocytochemical methods, we analyzed the localization of the HSP70 protein constitutively expressed during embryogenesis in the amphibian Pleurodeles waltl. Our results provide evidence for nuclear transfer of the protein during gastrulation, and particularly for predominant nuclear labeling in gastrula internalized cells. Using two inhibitors of DNA replication -hydroxyurea (HUA) and aphidicolin- or/and an inhibitor of transcription -actinomycin D- applied to embryos, we demonstrated that nuclear transfer of HSP70 is related to the transcriptional activity of the cells during the early S phase of the cell cycle.

Animals↗
PubMed1997

Benefit of active compression-decompression cardiopulmonary resuscitation as a prehospital advanced cardiac life support. A randomized multicenter study.

BACKGROUND: We compared short-term prognosis of active compression-decompression (ACD) and standard (STD) cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrests. METHODS AND RESULTS: We randomized advanced cardiac life support (ACLS) with ACD ACLS CPR on odd days and STD ACLS CPR on even days. We measured the rates of return of spontaneous circulation (ROSC), survival at 1 hour (H1), at 24 hours (H24), and at 1 month (D30): hospital discharge (HD); neurological outcome; and complications. Mean times from collapse to basic cardiac life support CPR was 9 minutes and from collapse to ACLS CPR was 21 minutes. Compared with the STD ACLS patients (n = 258), ACD ACLS patients (n = 254) had higher survival rates (ROSC, 44.9% versus 29.8%, P = .0004; H1, 36.6% versus 24.8%, P = .003; H24, 26% versus 13.6%, P = .002; HD without neurological impairment, 5.5% versus 1.9%, P = .03) and a trend for improvement in neurological outcome at D30 (Glasgow-Pittsburgh Outcome Categories = 1.6 +/- 0.8 versus 2.3 +/- 1.1. P = .09). Sternal dislodgements (2.9% versus 0.4%, P = .03) and hemoptysis (5.4% versus 1.3%, P = .01) were more frequent in the ACD ACLS group. CONCLUSIONS: Despite long time intervals, ACD significantly improved short-term survival rates in out-of-hospital cardiac arrests compared with STD CPR.

Adult↗
PubMed1997

Conditions for a heat shock response during oogenesis and embryogenesis of the amphibian Pleurodeles waltl.

The optimal conditions capable of inducing an increase in HSP70 neosynthesis during development of the urodele amphibian Pleurodeles waltl were determined in this study. These conditions depend on temperature, heat shock duration and recovery duration. In oocytes, a heat shock response was repeatedly obtained at 37 degrees C for 15 min followed by 1 h recovery. These results provided evidence for heat shock response at every stage considered. An increase in HSP70 synthesis was noted throughout oogenesis, but it did not lead to an increase in the amount of soluble HSP70, except for stage VI oocytes. Such results suggest that from stage II to stage IV oocytes, an equilibrium occurs between the HSP70 used and the HSP70 neosynthesized. In contrast, in stage VI oocytes, heat shock led to overproduction of HSP70. During early development, the heat shock response was repeatedly obtained only from the gastrula stage with a 37 degrees C shock and a 15 min duration of treatment. Surprisingly, during cleavage stage, the soluble HSP70 total amount increased after heat shock at a time when no HSP70 neosynthesis occurred.

Amino Acid Sequence↗
PubMed1996

Does the chaperone heat shock protein hsp70 play a role in the control of developmental processes?

Expression of an hsp70 gene strictly inducible in somatic cells and constitutively expressed during oogenesis was investigated during embryogenesis of the amphibian Pleurodeles waltl. Results from Northern hybridization experiments and RNase protection assays provided evidence for the presence of inducible hsp70 mRNA under normal conditions at every embryonic stage. Immunoblotting of embryo proteins separated by 2D-electrophoresis provided evidence for the presence of a single polypeptide of about 74 kDa likely to be an HSP70-related protein, from unfertilized egg to tailbud stage. Immunocytological analysis showed that HSP70-related proteins were localized in the cytoplasm of all blastomeres. It also pointed out that nuclear transfer of the protein occurs in certain cells, precisely at the time of their invagination and subsequent internalization during normal Pleurodeles development. Such nuclear transfer involves involuting mesodermal cells in the blastopore region at the time of gastrulation. It also involves neurodermic cells at the time of neural tube closure. Interestingly, in exogastrulas nuclear transfer did not occur in cells which could no longer invaginate. Such behavior of HSP70-related proteins led us to suggest that they are involved in the control of nuclear activity associated with important developmental events such as cellular internalization processes. Such a role may be a direct consequence of HSP70-related protein functional properties as molecular chaperones.

Animals↗
PubMed1995

c-mpl expression in hematologic disorders.

The c-mpl gene encodes a member of the hematopoietic cytokine receptor superfamily. This gene was discovered through the study of a murine retrovirus which induces an acute myeloproliferative syndrome in mice. MPLV (for myeloproliferative leukemia virus) has transduced a truncated and constitutively activated form of the c-mpl receptor chain. The c-mpl ligand is unknown, but recent data indicate that it could specifically regulate thrombocytopoiesis. This review focuses on the expression of the c-mpl gene in a large series of human hematopoietic pathologies by Northern blot analysis. Barely detectable transcript levels were detected in normal bone marrow (BM) and in BM samples from chronic myeloproliferative disorders, plasmocytoma, Burkitt lymphoma or acute lymphoid leukemia. In contrast, high levels of c-mpl expression were detected in 45% of acute myeloid leukemia (AML). No correlation was found between c-mpl expression and the French-American-British classification subtype of AML. However c-mpl expression correlated with CD34 expression, and unfavorable cytogenetic abnormalities, defining a subgroup of AML with a low rate of complete remission. In myelodysplasia, c-mpl expression was elevated in 44% of chronic myelomonocytic leukemia (CMML), 42% of refractory anemia with excess myeloblasts (RAEB), and RAEB in transformation to acute leukemia (RAEBt), but not in refractory anemia (RA) and RA with ringed sideroblasts (RARS). In CMML, there was no correlation between c-mpl expression and any prognostic factor tested, nor with the course of the disease. The biologic significance of c-mpl expression in RAEB and RAEBt is probably different.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗