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Biomedical subjects

M Catala

Publications and source records attributed to M Catala.

At least 73 records · Page 4Linked to original sources
PubMed1996

A male fetus with aqueductal stenosis and four accessory spleens. A case report with a tentative genetic explanation.

A male fetus presenting with prenatal hydrocephalus is reported. The fetus died during labor. Pathological examination disclosed four accessory spleens without any abnormalities of the situs. Hydrocephalus was secondary to aqueductal stenosis. Histological features of the aqueduct were consistent with a developmental defect. The association of such malformations has already been reported and could be explained by common regulatory mechanisms which control the splenic and neural tube development.

Abnormalities, Multiple↗
PubMed1996

Impairment of central motor conduction to the diaphragm in stroke.

Respiratory complications are common in patients with stroke, but the involvement of the diaphragm in this setting is not completely understood. The purpose of this study was to assess corticodiaphragmatic pathways in patients with vascular hemiplegia. Fifteen patients were studied, nine with a capsular type of hemiplegia. Seven age-matched subjects served as the control group, and eight healthy young volunteers were studied to validate the methods by comparison with the literature. Diaphragm electromyogram was recorded bilaterally, using surface electrodes. Abductor pollicis brevis electromyogram was also recorded. After having checked the integrity of peripheral conduction, corticofugal pathways were studied using cortical magnetic stimulation, a reproducible and patient-independent stimulus. Left and right conduction times to the diaphragm were symmetrical in the control subjects, the young volunteers, and the six patients with hemiplegia but without capsular lesion (16.5 to 20.1 ms). Conversely, they were markedly asymmetrical in patients with capsular hemiplegia, diaphragm response on the plegic side being abolished or markedly delayed. Although the clinical impact of these findings remains to be determined, this study confirms that "central diaphragm paralysis" can be present in stroke. It also indicates that there is no bilateral motor representation of each hemidiaphragm.

Adult↗
PubMed1996

Two distinct endothelial lineages in ontogeny, one of them related to hemopoiesis.

We have shown previously by means of quail/chick transplantations that external and visceral organs, i.e., somatopleural and splanchnopleural derivatives, acquire their endothelial network through different mechanisms, namely immigration (termed angiogenesis) versus in situ emergence of precursors (or vasculogenesis). We have traced the distribution of QH1-positive cells in chick hosts after replacement of the last somites by quail somites (orthotopic grafts) or lateral plate mesoderm (heterotopic grafts). The results lead to the conclusion that the embryo becomes vascularized by endothelial precursors from two distinct regions, splanchnopleural mesoderm and paraxial mesoderm. The territories respectively vascularized are complementary, precursors from the paraxial mesoderm occupy the body wall and kidney, i.e., they settle along with the other paraxial mesoderm derivatives and colonize the somatopleure. The precursors from the two origins have distinct recognition and potentialities properties: endothelial precursors of paraxial origin are barred from vascularizing visceral organs and from integrating into the floor of the aorta, and are never associated with hemopoiesis; splanchnopleural mesoderm grafted in the place of somites, gives off endothelial cells to body wall and kidney but also visceral organs. It gives rise to hemopoietic precursors in addition to endothelial cells.

Animals↗
PubMed1996

A spinal cord fate map in the avian embryo: while regressing, Hensen's node lays down the notochord and floor plate thus joining the spinal cord lateral walls.

The spinal cord of thoracic, lumbar and caudal levels is derived from a region designated as the sinus rhomboidalis in the 6-somite-stage embryo. Using quail/chick grafts performed in ovo, we show the following. (1) The floor plate and notochord derive from a common population of cells, located in Hensen's node, which is equivalent to the chordoneural hinge (CNH) as it was defined at the tail bud stage. (2) The lateral walls and the roof of the neural tube originate caudally and laterally to Hensen's node, during the regression of which the basal plate anlage is bisected by floor plate tissue. (3) Primary and secondary neurulations involve similar morphogenetic movements but, in contrast to primary neurulation, extensive bilateral cell mixing is observed on the dorsal side of the region of secondary neurulation. (4) The posterior midline of the sinus rhomboidalis gives rise to somitic mesoderm and not to spinal cord. Moreover, mesodermal progenitors are spatially arranged along the rest of the primitive streak, more caudal cells giving rise to more lateral embryonic structures. Together with the results reported in our study of tail bud development (Catala, M., Teillet, M.-A. and Le Douarin, N.M. (1995). Mech. Dev. 51, 51-65), these results show that the mechanisms that preside at axial elongation from the 6-somite stage onwards are fundamentally similar during the complete process of neurulation.

Animals↗
PubMed1995

Aphasia and infarction of the posterior cerebral artery territory.

Spoken language disorders are rarely mentioned in superficial infarction of the posterior cerebral (PCA) territory. Two clinical types have been reported: transcortical sensory and amnesic aphasia. Between 1979 and 1990, we studied retrospectively 76 patients suffering from an occipitotemporal infarction located in the superficial territory of the posterior cerebral artery, all well documented by CT. Aphasia was one of the first and prominent signs in 18 cases. Middle cerebral artery concomitant infarction could have been the cause of language impairment in 10. In 8 patients aphasia was only explained by a PCA territory infarct. Three patients showed features of transcortical sensory aphasia. CT localization showed internal lobe and thalamic involvement of the dominant hemisphere. Five patients exhibited word finding impairment with various degrees of amnestic syndrome. The dominant internal temporal lobe was always affected. Dominant thalamus involvement was found in one case only. Some correlations between clinical features and anatomical support (vascular supply and anatomical structure) might be suggested in our 8 cases of aphasic disorders due to PCA infarcts. They are discussed and compared with data in the literature.

Adult↗
PubMed1995

Organization and development of the tail bud analyzed with the quail-chick chimaera system.

After closure of the posterior neuropore, the caudal part of the embryo designated as the 'tail bud' forms a mass of undifferentiated cells from which the lumbosacral and caudal parts of the body develop. It has been proposed that the tail bud is a homogeneous structure comparable to a blastema (Holmdahl, 1925; Griffith et al., 1992). Another view is that morphogenesis of the tail bud is merely the continuation of the gastrulation process (Pasteels, 1937, 1943). In order to try to solve this controversy, we have studied the fate of definite and discrete regions of the tail bud at the 25-somite stage by using the quail-chick marker system. We found that the tail bud is composed of different domains endowed with a definite fate. A ventro-rostral region equivalent to the chordo-neural hinge defined by Pasteels gives rise to the notochord and floor plate and thus corresponds to the Hensen's node which in the tail bud pursues its rostrocaudal movement. The presumptive territory of the lateral walls of the lumbo-sacro-caudal neural tube is located caudally to the Hensen's node as it stands at the 25-somite stage. Material destined to form the sacral and caudal somites is still located in the dorsal midline in the caudalmost part of the tail bud. We thus show that the movements of invagination and divergence which characterize gastrulation are still going on in the tail bud after the 25-somite stage. Thus the somitic material located medio-dorsally diverges laterally and contributes by apposition to the growth of the trunco-caudal part of the body. The parallel between tail bud development in Amniotes and Amphibians as described recently by Gont et al. (1993) is striking and points to the unity in the development mechanisms within the Vertebrate phylum.

Animals↗
PubMed1995

The GATA-3 gene is expressed during human kidney embryogenesis.

GATA-3 is a transcription factor involved in the differentiation of T lymphocytes and additionally expressed in several chicken and mouse embryonic tissues. Using in situ hybridization, we found that the human GATA-3 gene is selectively expressed in the developing kidney. GATA-3 mRNA is first detected in the Wolffian duct from the time of its emergence in the embryonic intermediate mesoderm and further expressed in the collecting ducts of the mesonephros until its involution. In the metanephros, GATA-3 is expressed in the ureteric bud where it is constitutively transcribed, throughout development, along the branching process that gives rise to the whole collecting system of the definitive kidney. Besides the Wolffian duct and derivatives, we also report the expression of GATA-3 gene in the glomerular mesangium and adjacent endocapillary cells, in both meso- and metanephros. This early and specific expression of the GATA-3 gene suggests a role for this transcription factor in the differentiation of the human kidney.

DNA-Binding Proteins↗
PubMed1995

[Bilateral occlusion of the internal carotid arteries. Analysis of a series of 19 patients].

The natural history of patients suffering from bilateral internal carotid occlusion is poorly known. We report a study of 19 patients presenting such a vascular condition as demonstrated by angiography. In all our cases, cardio-vascular risk factors were frequently found. Smoking was particularly frequent and present in 18 patients (95%). Presenting neurological episodes included either transient ischemic attack (8/19) or stroke (9/19). Associated arterial lesions were diffusely distributed on the other cerebral vessels, frequently involving the extra-cranial part of the vertebral arteries. Collateral circulation feeding the intracranial carotid system mainly, or exclusively, originated from the vertebro-basilar system. Ischemic strokes were frequently detected by cerebral CT scan. They were located in the middle cerebral territory or at the junctions between 2 major cerebral arteries. A radiological aspect of cortical atrophy was noted in 9 patients among 19. Regional cerebral blood flow assessed by Xe133 inhalation was usually normal at rest (16/19), but hyporeactivity to acetazolamide was found in 10 patients among 19. The latter was more frequent in patients suffering from arterial hypertension or diabetes mellitus. Our results confirm that the patients suffering atheromatous bilateral occlusion of the internal carotid arteries may survive with minimal neurological deficits. Collateral circulation is mainly provided by the vertebro-basilar system allowing to frequently maintain normal cerebral blood flow at rest.

Aged↗
PubMed1994

Schnitzler's syndrome associated with sensorimotor neuropathy.

We describe a patient with chronic urticaria in association with monoclonal IgM gammopathy (Schnitzler's syndrome). Seven years after the onset of the cutaneous lesions sensorimotor neuropathy developed. Myelin-associated glycoprotein was detected in the patient's serum. High doses of corticosteroids improved the skin condition but failed to prevent the neuropathy. Six months of treatment with immunoglobulins was without benefit.

Aged↗
PubMed1994

Alphabetical paragraphia in a limited middle cerebral artery stroke.

A Yugoslavian perfectly bilingual for French and Serb had a limited left middle cerebral artery stroke. He developed a peculiar dysgraphia characterised by the use of Latin characters (French spelling) to transcribe Serb phonemes that would normally have been spelt in the Cyrillic alphabet. This dysgraphia was likely to be due to an impairment of the allographic procedure. It is concluded that allographs of the two alphabets are produced concomitantly in bialphabetical patients during the allographic procedure.

Agraphia↗
PubMed1994

[Intracerebral extension of cervical paraganglioma].

A large paraganglioma invaded the neck and skull, with extension into the right supratentorial cerebral hemisphere through the calvarium. Immunohistological markers were found useful for the diagnosis. The patient died rapidly. Despite no evidence of metastasis, the usually benign paraganglioma can have a malignant course.

Brain Neoplasms↗
PubMed1994

[Amnestic syndromes and confabulation in infarction of the posterior cerebral artery area].

The Posterior Cerebral Artery (PCA) supplies the greatest part of the limbic system. Several authors have reported amnestic syndromes in PCA infarcts. Amongst 76 patients with a CT proven PCA infarct, 21 suffered anterograde amnesia. Confabulations were associated in 5 cases. We studied CT scans according to previously reported templates in the 21 amnestic patients: all patients with confabulations had a paramedian or a tuberothalamic infarct associated with a cortical infarct within the superficial territory of the PCA. None of the 16 remainders had a thalamic lesion. These results emphasize the role of the thalamus especially of the dorsomedial nucleus in the pathogenesis of confabulation. The underlying mechanism could imply fronto-cingular deafferentation.

Adult↗
PubMed1993

[Late disclosure of intra-cerebral epidermoid cyst].

Symptoms of right hemisphere dysfunction had developed over a 10-month period in a 69-year old woman. She had experienced transient episodes of facial asymmetry for 10 years. CT scan showed a hypodense hourglass tumor extending above and below the tentorium. MRI showed a low-intensity signal with T1-weighted sequences and a high-intensity signal with T2-weighted sequences. The tumour was removed. Pathological examination proved the tumor to be an epidermoid cyst. Such a tumor may have been responsible for transient deficits in the late stages of development.

Aged↗
PubMed1991

[Molecular biology of subacute spongiform encephalitis].

Subacute spongiform encephalitis is a pathology that is common to 4 human and 4 animal diseases. These diseases are characterized by the neurological lesions they share and by the fact that they can be transmitted to animals. An abnormal isoform of an endogenous central nervous system protein has been identified. It might be the sole pathogenic agent, but it is certain that it plays a major role in the expressivity of the disease.

Animals↗