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Biomedical subjects

J C Renaud

Publications and source records attributed to J C Renaud.

11 recordsLinked to original sources
PubMed2001

[Pseudotumoral forms of sarcoidosis].

We report 5 cases of sarcoidosis in 4 men and 1 woman who presented multinodular pulmonary lesions. Seldom described (1 to 4% of all cases of sarcoidosis), a multinodular pulmonary presentation is suggestive of metastatic disease. In our patients, the parenchymal opacities were multiple, peripheral and exhibited fuzzy limits, measuring 1 to 7 cm in size and frequently associated with mediastinal adenopathies. The radiographic pattern contrasted with the clinical manifestations (3 of the 5 cases were fortuitous discoveries). Pathological proof required to rule out other disease, especially tumor formation, was acquired; mediastinoscopy allowing the diagnosis in 3 out of 5 cases. The clinical course was favorable in all cases without treatment within 8 +/- 5 months and a mean follow-up of 5 years (range 9 months to 14 years).

Adult↗
PubMed2001

[Spontaneous resolution of a giant pulmonary bulla].

There are different causes leading to formation of pulmonary bullae, in particular tuberculosis. There is some debate concerning the pathophysiology of bullae extension although two mechanisms are put forward: partial obstruction of the airways and elastic recoil of adjacent lung parenchyma with a negative pressure in the bullae. Pulmonary function tests are highly perturbed in patients with giant bullae. The natural history of bullae is enlargement although spontaneous regression is rarely described. Bullae should be resected in selected patients, others require careful follow-up. We present the case of a man with tuberculosis who developed a giant pulmonary bulla that regressed spontaneously in a few years.

Adult↗
PubMed1997

[A rare biphasic pulmonary tumor, carcinosarcoma. A separate entity or differentiation variant of spindle-cell carcinoma?].

We report a case of pulmonary carcinosarcoma. Surgery is required for this rare mixed type, biphasic tumor. It is generally considered to be a malignant formation issuing from a single cell line but with a two-way differentiation into epithelial and conjunctive components. There is a differentiation continuum between spindle-cell carcinomas (also called monophasic sarcomatoid carcinoma) and carcinosarcoma (or biphasic sarcomatoid carcinoma) leading to debate concerning the immunohistochemical and ultrastructural features.

Carcinosarcoma↗
PubMed1991

A numerical solution to the equilibria of the two-locus two-allele selection model.

Examination of the equilibria of the standard two-locus two-allele selection model leads to the construction of a polynomial with coefficients derived from selective values in the genotypic fitness matrix. This polynomial can be partially factored algebraically and numerical techniques are available to extract the roots of the remainder. Each root provides a possible value of the disequilibrium coefficient and the gametic frequencies at equilibrium, and these can be readily checked for stability.

Alleles↗
PubMed1986

[Value of the subxiphoid approach in 2-dimensional echocardiography for the diagnosis of ductus arteriosus in premature infants and infants].

The preliminary results of our experience with the "inverted" subxiphoid approach for 2D echocardiographic visualisation of patent ductus arteriosus (PDA) in premature neonates and infants are reported. Eight premature ventilated neonates weighting 870 to 1,200 g with an isolated PDA were examined by this technique using a mechanical sector scanner and a 7.5 MHz transducer; three views were obtained (left ventricular outflow tract or "long axis"; an oblique view through the two atria and aortic arch; short axis view of the ventricles). A PDA was directly visualised in 6 of the 8 patients. It was possible to measure its diameter and observe its tortuous or rectilinear trajectory; the outcome of Indomethacin therapy or surgical ligature could also be evaluated. In the 2 patients in whom the PDA was not visualised, there were no clinical symptoms or echocardiographic signs of shunt: these PDA were therefore probably extremely small. In the neonate and infant, it is relatively easy to demonstrate a PDA by this approach. The PDA can also be followed up in "ductus dependent" congenital heart disease during treatment with Prostaglandin E. In conclusion, the subxiphoid approach represents an interesting alternative for the visualisation of PDA, especially in premature neonates in whom the suprasternal and parasternal views are often difficult to obtain.

Ductus Arteriosus, Patent↗
PubMed1985

[Coronary anomalies associated with the Williams-Beuren syndrome. Apropos of 2 cases].

Two coronary artery anomalies associated with the Williams-Beuren syndrome are reported. The first case was a 14 year old child with severe supra-aortic stenosis associated with severe hypoplasia of the ascending aorta; 2 D echocardiography and angiography showed a voluminous aneurysm of the left main coronary artery. Aortoplasty with a patch gave a good early result. The second case was a two and a half months old baby operated as an emergency after cardiac arrest and who died at the end of surgery. The baby had severe supra-aortic stenosis, occlusion of the left coronary ostium by the left anterior cusp which was abnormally adherent to the aortic wall with subendocardial infarction and reaction fibroelastosis. The frequency of coronary anomalies associated with the Williams-Beuren syndrome is probably underestimated. Because of their severity they must be looked for routinely, by echocardiography and angiography. Their tendency to progress is an indication for early surgical correction of severe supra-aortic stenosis.

Adolescent↗