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C Jouve

Publications and source records attributed to C Jouve.

9 recordsLinked to original sources
PubMed2000

Somite formation and patterning.

As a consequence of their segmented arrangement and the diversity of their tissue derivatives, somites are key elements in the establishment of the metameric body plan in vertebrates. This article aims to largely review what is known about somite development, from the initial stages of somite formation through the process of somite regionalization along the three major body axes. The role of both cell intrinsic mechanisms and environmental cues are evaluated. The periodic and bilaterally synchronous nature of somite formation is proposed to rely on the existence of a developmental clock. Molecular mechanisms underlying these events are reported. The importance of an antero-posterior somitic polarity with respect to somite formation on one hand and body segmentation on the other hand is discussed. Finally, the mechanisms leading to the regionalization of somites along the dorso-ventral and medio-lateral axes are reviewed. This somitic compartmentalization is believed to underlie the segregation of dermis, skeleton, and dorsal and appendicular musculature.

Animals↗
PubMed2000

Notch signalling is required for cyclic expression of the hairy-like gene HES1 in the presomitic mesoderm.

Somitic segmentation provides the framework on which the segmental pattern of the vertebrae, some muscles and the peripheral nervous system is established. Recent evidence indicates that a molecular oscillator, the 'segmentation clock', operates in the presomitic mesoderm (PSM) to direct periodic expression of c-hairy1 and lunatic fringe (l-fng). Here, we report the identification and characterisation of a second avian hairy-related gene, c-hairy2, which also cycles in the PSM and whose sequence is closely related to the mammalian HES1 gene, a downstream target of Notch signalling in vertebrates. We show that HES1 mRNA is also expressed in a cyclic fashion in the mouse PSM, similar to that observed for c-hairy1 and c-hairy2 in the chick. In HES1 mutant mouse embryos, the periodic expression of l-fng is maintained, suggesting that HES1 is not a critical component of the oscillator mechanism. In contrast, dynamic HES1 expression is lost in mice mutant for Delta1, which are defective for Notch signalling. These results suggest that Notch signalling is required for hairy-like genes cyclic expression in the PSM.

Amino Acid Sequence↗
PubMed1998

Role of growth factors in shaping the developing somite.

In the vertebrate embryo, the lateral somite gives rise to limb bud and body wall muscles whereas the medial somite generates the axial musculature. We show that in chick embryos, this polarity along the medio-lateral axis is achieved through the antagonistic influences of the lateral plate and the medial neural tube. Bone morphogenetic protein 4 (BMP4) mediates the lateralising signal delivered by the lateral plate and is counteracted locally by Noggin expressed in the medial dermomyotome; Noggin expression in the somite is regulated by the Wntl protein which is expressed in the dorsal neural tube and mediates the medialising effect of the neural tube. Therefore, somite medio-lateral patterning results from a signalling cascade in which Wnt1 produced by the neural tube promotes noggin expression in the medial somite which in turn antagonises lateral plate-derived BMP4. This mechanism could lead to the establishment of a BMP4 activity gradient that would produce appropriate BMP4 signalling to generate medial and lateral somite patterning.

Animals↗
PubMed1997

Noggin acts downstream of Wnt and Sonic Hedgehog to antagonize BMP4 in avian somite patterning.

In the vertebrate embryo, the lateral compartment of the somite gives rise to muscles of the limb and body wall and is patterned in response to lateral-plate-derived BMP4. Activation of the myogenic program distinctive to the medial somite, i.e. relatively immediate development of the epaxial muscle lineage, requires neutralization of this lateral signal. We have analyzed the properties of molecules likely to play a role in opposing lateral somite specification by BMP4. We propose that the BMP4 antagonist Noggin plays an important role in promoting medial somite patterning in vivo. We demonstrate that Noggin expression in the somite is under the control of a neural-tube-derived factor, whose effect can be mimicked experimentally by Wnt1. Wnt1 is appropriately expressed in the neural tube. Furthermore, we show that Sonic Hedgehog is able to activate ectopic expression of Noggin resulting in the blocking of BMP4 specification of the lateral somite. Our results are consistent with a model in which Noggin activation lies downstream of the SHH and Wnt signaling pathways.

Animals↗
PubMed1993

Detection of quantitative polymerase chain reaction products by hybridization on magnetic support with 125I-radiolabeled probes: quantification of c-myc copy numbers.

We present a technique for determining c-myc copy numbers that can be used as a prognosis index for some cancers. The method is based on the use of both competitive polymerase chain reaction and hybridization of amplified products. Coamplification was performed directly on cells with a synthetic oligonucleotide used as internal standard. It recognized the same primer set as the target. Coamplified products were captured on streptavidin magnetic beads as solid support using a 5' biotinylated primer. DNA immobilized on this support was denatured with alkali. Each coamplified product (target and reference gene) was further hybridized to two distinct specific oligonucleotide probes. Gene amplification levels were determined using a standard curve obtained by serial dilutions of peripheral blood lymphocytes run along with the experimental samples. This approach provides a rapid (less than 2 days) and reproducible method for evaluating c-myc gene copy number and may be used to quantify any gene. Moreover, its format allows for automation.

Bacterial Proteins↗
PubMed1986

[Cutaneous parotid fistula of calculous origin].

A case of cutaneous salivary fistula is presented. A 42-year-old man had a recurrent inflammatory parotid disease which disappeared with the expulsion of the calculus. The authors note the rarity of this evolution in the literature and suggest a protocol of treatment.

Adult↗
PubMed1982

[Prophylaxis of infectious complications in maxillo-facial surgery. Value of cefazolin. (A review of 400 cases)].

The value of short-term prophylaxis with antibiotics in maxillo-facial surgery and plastic facial surgery is studied. 200 patients were included in the study and compared to 200 controls who were given the usual systematic antibiotic therapy, with a different antibiotic, for more than 6 days. 400 case-reports were thus retrospectively analyzed. The results show that when the surgical procedure lasts for less than three hours, short-term prophylaxis with antibiotics is more effective than the usual systematic antibiotic therapy given for more than 6 days.

Cefazolin↗
PubMed1980

[Irradiation of basal cell epitheliomas of the face: a handicap for the surgeon in some cases of recurrence (author's transl)].

A case is reported which illustrates the progressive relapsing nature and local invasive character of certain irradiated basal cell epitheliomas. One such case, that involved the tragus initially, and had been irradiated on five occasions, successively invaded the lobe of the ear, the auditory canal, the helix, the mastoid, and the zygomatotemporal region in spite of six operations and the use of cryotherapy.

Aged↗