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Biomedical subjects

G Couly

Publications and source records attributed to G Couly.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Development of the face in the embryo].

The facial complex and the brain develop separately from a common embryonic structure called ectoblast. The neural crest cells which migrate early on from the neural groove differentiate into facial parenchyma, so that the embryological origin of the face is a neural one. The cephalic pole has a primitive encephalofacial and encephalocervical segmentation with strict topographical correspondence: the nasofrontral and premaxillary structures are related to the anterior brain, whereas the maxillo-mandibular and anterior cervical structures are related to the brainstem and its nerves. Thus the face is a qualitative, quantitative and topographical marker of the central nervous system. At the beginning of the third month the embryo becomes a foetus due to the appearance of the first oral and pharyngeal motor sequences which are dependent upon the neurological development of the brainstem. This sum of embryological knowledge has clinical semiological applications: the face and its functions play the predictive role in the search for associated malformations of the same neural origin (brain, eye, neck, thorax). Such malformations are neurocristopathies.

Branchial Region↗
PubMed1991

[Parotid carcinoma in children. Apropos of 3 cases].

Three pediatric cases of parotid carcinoma are reported two are acinic cell carcinoma of relatively good prognosis. The third case is a cystic variety of salivary duct carcinoma, more exceptional, which prognosis remains uncertain. A review of the parotid tumors of this age range is done.

Adenocarcinoma↗
PubMed1990

Head morphogenesis in embryonic avian chimeras: evidence for a segmental pattern in the ectoderm corresponding to the neuromeres.

Areas of the superficial cephalic ectoderm, including or excluding the neural fold at the same level, were surgically removed from 3-somite chick embryos and replaced by their counterparts excised from a quail embryo at the same developmental stage. Strips of ectoderm corresponding to the presumptive branchial arches were delineated, thus defining anteroposterior 'segments' (designated here as 'ectomeres') that coincided with the spatial distribution of neural crest cells arising from the adjacent levels of the neural fold. This discrete ectodermal metamerisation parallels the segmentation of the hindbrain into rhombomeres. It seems, therefore, that not only is the neural crest patterned according to its rhombomeric origin but that the superficial ectoderm covering the branchial arches may be part of a larger developmental unit that includes the entire neurectoderm, i.e., the neural tube and the neural crest.

Animals↗
PubMed1989

Congenital soft tissue dysplasia: a new malformation entity and concept.

We report 185 children with clinical manifestations of various conditions classically described as giant hamartoma, angiodysplasia, congenital hypertrophy, congenital trophoedema, localised gigantism (e.g. macrodactyly), etc. It is proposed to group all these conditions into a single entity: congenital soft-tissue dysplasia (CSTD). According to recent advances in fundamental embryology and cell biology, CSTD appears to be a consequence of embryonal or fetal cell biosynthetic dysregulation. The concept of the CSTD entity leads to a common protocol for clinical investigation and a common therapeutic plan, with special reference to the stability and the benign nature of the condition. Treatment should be confined to improving function rather than attempting to correct cosmetic deficits.

Adolescent↗
PubMed1988

[The Pierre-Robin syndrome. Classification and new therapeutic approach].

Rhombencephalic failure of the suction-swallowing, excess of central and obstructive ventilatory arrests with hypoxia and hypercapnia, vagal hypertonia and esophagogastric motor abnormalities are the new clinical signs observed in children presenting with the Pierre Robin's syndrome. A therapeutic management adapted to each of the types I, II, III of the syndrome were defined and a good nursery-nursing allowed a reduction in the mortality-rate from 27 to 5%. Still considered by some as a malformative and glossoptosing disorder whose etiology is only bucco-pharyngeal in origin, this syndrome, common to numerous embryopathies, is a precocious embryonal abnormality of the brain stem neurogenesis, expressed by the dramatic failure of the physiological oro-ventilation system. This syndrome appears to be a peculiar form of dysautonomia of the brain stem development with an uncertain future, often transitory, isolated or associated but in the heart of pediatric internal medicine and its multi-disciplinarity.

Asphyxia↗
PubMed1988

[Associated morphological anomalies of the face and brain in infants].

Thirty-nine malformations and morphological abnormalities of the brain are analysed among a group of 300 children presenting facial malformations or dysembryoplasias (13%) between 1979 and 1986. Holoprosencephaly was discovered associated with bilateral labiomaxillary cleft in 25% of cases and an abnormality of brain stem was observed in 13% of cases with maxillo-mandibular dysostosis. This high incidence, due to the bias of hospital recruitment, confirms the recent experimental studies on embryonic development demonstrating the common neural origin of the face and brain, between which there is a topographic correspondence. To the nasofronto-premaxillary structures corresponds the whole prosencephalon and to the maxillo-mandibular areas correspond the brain stem and its nerves. The demonstration of the neural crest's role in the morphogenesis of the facial mesenchyme, the meninges and the nerves further confirms these associations of malformations in phacomatoses or neurocristopathies. Thus, the face appears as a marker of the development of the brain.

Abnormalities, Multiple↗
PubMed1987

[In favor of glossology. Knowledge and practice regarding the tongue].

Despite recent advances in embryology, lingual morphologic development remains partially obscure. Neurophysiology of development of tongue in the fetus and young infant is dominated by the motor orality which requires, at an early stage, both sensorial and motor organization of the brain stem. Starting with this baseline sensorial organization, there develops in the young child a increasingly complex growth gradient of lingual gnosis and praxis (general oral), starting with the spoon-feeding praxis at about 6 months of age. The language eclosion then follows during the second year with helicoidalization of mandibular gesture leading to the "form-inform" tongue at about 7 years of age possessing proprioception of a non-fusorial sensory origin--the absence of this would cause it to be at the mercy of the teeth. An organ which lengthens by contracting clearly merits its own science....

Animals↗
PubMed1983

[Current concepts of the biology of the development of the human head. Observations and hypotheses].

Morphological dynamics controlling vertebrate embryo development, which takes place in flotation in a liquid medium, leads to the hypothesis that the pentameric symmetry of echinodermes, ancestors of the vertebrates, is conserved during evolution. This embryogenesis consists of morphological repetitions: synchronous growth of five expansions specialized in exploration and spatial deplacements (head and four limbs); each of these five expansions consists of five buds or five radii (facial buds, fingers and toes). Homomorphism of the mouth, of the hands, and of the feet--which are capture catastrophes over the environment, installed early during development--allows later functional and sensory connections. These morphological repetitions are also demonstrated by the association of facial, hand, and foot buds, malformations for which a topological correspondance can be shown. During vertebrate morphogenesis by flotation in a liquid medium, other phenomena take place. For instance, the palate is formed anteriorly by a triple junction resulting from the fusion of its three constitutive buds.

Congenital Abnormalities↗
PubMed1983

[Laterofacial malformations (maxillomandibular neurocristopathies) associated with anomalies of the brain stem and cranial nerves].

Neurological and cerebral computed tomography examinations were conducted in 25 infants and young children with uni- or bilateral maxillomandibular neurocristopathies (Goldenhar's, Franceschetti's first arch syndromes or transient forms). Taking all lesions into account, 18 children (82%) presented morphological and motor anomalies of the brain stem (mesencephalus, metencephalus) and its corresponding cranial nerves: four had morphological anomalies of the cerebellum and pons; four presented disorders of bulbopontine control (heart, lungs, deglutition); fifteen demonstrated sensory, sensorial, and motor deficiencies of the paired cranial nerves III, V, VI, VII, and VIII. The high frequency of ocular malformations in this series is emphasized: there were three cases of cryptophthalmia and one case of bilateral iris coloboma. These findings are in agreement with recent acquisitions in the field of cephalic developmental biology: the cephalic neural crest cells, after migration from the mesencephalorhombencephalic neural fold, contribute to the latero-facial and ocular organogenesis. The unity of origin of the face and brain provides an explanation for the predictive role of the former in case of malformations of the brain and its cranial nerves.

Brain Stem↗
PubMed1983

[Di George syndrome, exemplary rhomboencephalic neurocristopathy].

Di George's syndrome associates hypocalcemia and hyperphosphoremia (phosphocalcic disorders from absence of the parathyroids), cell immunity disorders related to agenesis or hypoplasia of the thymus, and large vessels malformations (pulmonary artery, aorta) with cardiac lesions. The disorder is the result of deletion of rhomboencephalic neural crests cells, Di George's syndrome being an exemplary rhomboencephalic neurocristopathy. This organic syndrome is associated with early disorders of the same neurological region (the rhomboencephalon), expressed clinically by sucking and swallowing disturbances and cardiorespiratory regulatory disorders. Early rhomboencephalic lesions can lead to velopalatal division and microretrognathism secondary to a lingual motility disturbance. The association of this neurocristopathy with a neural tube lesion constitutes a dysneurulation. Fetal and neonatal retrognathism are evidence of bulbar involvement. Di George's and Pierre Robin's syndromes constitute two fairly similar clinical expressions of the same embryonic deficiency of rhomboencephalic neurulation.

Brain↗
PubMed1983

[A new concept of Pierre Robin syndrome and disease: dysneurulation of the rhombencephalon].

Pierre Robin's syndrome, a disorder apparently constituted by peripheral signs, is in fact the result of early major disturbances of ontogenesis of motor and regulatory organization of the fetal rhombencephalon. This is confirmed by the presenting signs in neonates with Pierre Robin's syndrome: --electrophysiological deglutition and sucking disorders as demonstrated on electromyography; --disorders in tone of tongue, pharyngeal and laryngeal muscles; --cardiac and respiratory regulatory disorders as shown by central and obstructive apneas with diminished oxygen pressure and bradycardia of central origin during sleep; and gastro-esophageal reflux. Associated signs indicating that Pierre Robin's syndrome is a separate disease entity are: --evidence of a rhomboencephalic neurocristopathy (malformation of 3rd and 4th aortic arch arteries, thymic and parathyroid hypoplasia) associated with a central rhomboencephalic lesion and resulting in dysneurulation; --mesencephalic lesion as seen in Stickler's syndrome and prosencephalic lesion as in Binder's syndrome, indicating more diffuse cephalic dysneurulation. The common origin of Di George's and Pierre Robin's syndromes is emphasized, the neonatal microretrognathism of the latter syndrome being a bulbar sign. Pierre Robin's syndrome has a poor prognosis, as there is a fatal outcome in one out of four neonates affected, and it appears to be an affection that is the clinical expression of an early major anomaly of cephalic neurulation.

DiGeorge Syndrome↗