[Tamponade due to Porphyromonas gingivalis]. / Tamponnade a Porphyromonas gingivalis.

A 45 year old man, 10 weeks after angioplasty and endoprosthesis insertion for myocardial infarction, developed tamponade in an infectious context. RNA 16S investigation, using the universal amplification method with ribotyping, detected Porphyromonas gingivalis (a strict anaerobic bacillus associated with peridontitis) in the pericardial fluid. This appears to be the first description of such a clinical scenario, and suggests 5 aetio-pathological mechanisms: fissure syndrome, malignant tamponade, post-infarction pericardial syndrome, endoprosthesis infection and infectious tamponade. We also describe the ribotyping method, which by amplifying DNA coding for RNA 16S allows identification of an increasing number of micro-organisms implicated in infectious pathology.

Effect of relaxin on the phenotype of collagens synthesized by cultured rabbit chondrocytes.

The effect of porcine relaxin on rabbit articular and growth plate chondrocytes in primary culture was investigated by measurement of total collagen production and analysis of the phenotypes of newly synthesized collagen chains. A 24-h treatment of monolayer articular and multilayer growth plate chondrocytes with 2 micrograms per ml relaxin had no effect on total DNA and did not significantly modify the amount of [3H]proline-labelled collagen chains secreted by the cells. However, polyacrylamide gel electrophoresis demonstrated relevant modifications in relaxin treated chondrocytes. A significant increase was observed in the proportion of type III collagen and in the intensity of the band corresponding to alpha 2I chains. Two-dimensional peptide mapping of CNBr-cleaved molecules indicated that the band that was identified as alpha 1II on monodimensional gels contained a significant proportion of alpha 1I collagen chains, as demonstrated by the presence of alpha 1I cyanogen bromide-digested peptides. The intensity of this band was increased by relaxin treatment. Furthermore, total RNA analysis by slot blot and Northern blot techniques showed a dose-dependent stimulation of alpha 1I and alpha 1III mRNA levels after incubation with increased relaxin concentrations, but no change in the amount of alpha 1II mRNA. These results suggested that when added to cartilage cells in vitro, relaxin modulated the expression of type I, type II and type III collagen genes by amplifying the dedifferentiation process.

Carpentier-Edwards supraannular porcine bioprosthesis in aortic position: 16-year experience.

BACKGROUND: The aim of the study was to evaluate the long-term results of aortic valve replacement with the Carpentier-Edwards supraannular porcine bioprosthesis. METHODS: A total of 278 patients who underwent aortic valve replacement between January 1983 and December 1986 were reviewed. Mean age was 69.4+/-11.0 years (range 24 to 90 years). RESULTS: The operative mortality was 8.6% (24 patients). The total follow-up was 2367.1 years (mean 9.3+/-4.3 years, maximum 15.5). The late mortality rate was 6.8%/patient-year (162 patients) and the overall survival at 15 years was 26.5%+/-3.6%. Structural valve deterioration (SVD) occurred in 19 patients (linearized rate 0.8%/ patient-year). The mean time to onset of deterioration was 10.9+/-2.9 years. This time was independent of the age at the time of implantation. The freedom from SVD at 10, 12, and 15 years for patients aged less than 60 was respectively 87.6%+/-6.8%, 77.8%+/-8.9%, and 44.2%+/-12.9% (linearized rate 3.3%/patient-year). For patients aged 61 to 70 years, freedom from SVD was, respectively, 100%, 97.3%+/-2.1%, and 80.8%+/-8.3% (linearized rate 0.63% patient-year). For patients older than 70 years, it was respectively 99.1%+/-0.9%, 95.6%+/-2.6%, and 93.3%+/-3.3% (linearized rate 0.31%/patient-year). No significant difference was observed below the age of 60 years (< or =50 vs 51 to 60 years) or in the older subgroups (61 to 70 years, vs >70 years). CONCLUSIONS: The Carpentier-Edwards supraannular bioprosthesis in aortic position provides low rate of structural valve deterioration at 15 years in patients aged more than 60 years at the time of implantation. The mean time to onset of SVD is independent of the subject's age at the time of implantation. After 60 years, the risk of deterioration is low and does not present any significant variation. The Carpentier-Edwards supraannular bioprosthesis can reliably be used for aortic valve replacement in patients over the age of 60 years because, beyond this age, SVD is observed much more rarely.

[Long-term results of valve replacement using the Cobomedics prosthesis]. / Résultats éloignés des remplacements valvulaires avec la prothèse Carbomedics.

The Carbomedics valve prosthesis is a second generation mechanical prosthesis with a double hemi-disc. This study analysed long-term morbidity and mortality associated with this prosthesis. Between 1987 and 1996, 397 prostheses were implanted, 306 aortic, 42 mitral and 26 double replacements (3 combining a Carbomedics aortic prothesis with a mitral valve from another type) in 370 patients with a mean age of 62 (range 4 to 88 years). The global operative mortality was 7.4%. A questionnaire sent to treating cardiologists, general practitioners and patients updated the prospective data base of the cardiac surgical department. The follow-up was 99%, representing a total of 1244 patient-years with an average of 41 months (range 1.1 month to 9.9 years). The 1, 3, 5 and 7 year survival (operative mortality included) was 88%, 80%, 76% and 69.6% respectively. Haemorrhagic complications were the most common (17 cases, 1.36% per patient-year) and 11 thromboembolic episodes were observed (0.88% per patient-year) with a higher incidence (p < 10-4) in mitral valve replacement (3.8% in patient-year). The other complications observed were: 5 aseptic paravalvular leaks (0.4% per patient-year) and 5 prosthetic valve infections; no structural alterations were observed. In all, ten reoperations (0.8% per patient-year) were required for prosthetic valve complications. This study shows the reliability of Carbomedics valve prostheses with a low complication rate comparable to that of other modern mechanical valve prostheses.

[The complement system in hepatopathies]. / Le système du complément au cours des hépatopathies.

Low serum complement is often observed in cirrhosis of the liver. This is the result of two mechanisms: a failure to synthesise a certain number of components and regulatory proteins of complement, and an increased consumption due to activation of the complement system. This acquired deficit in complement contributes to the increased risk of infection in patients with cirrhosis.

Interferon-gamma mRNA expression upon in vitro T lymphocyte activation is decreased in rheumatoid arthritis patients.

A decreased production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) upon in vitro stimulation by phytohemagglutinin (PHA) peripheral blood leucocyte in active rheumatoid arthritis (RA) patients has been described as an important immunological abnormality in this disease. However, the molecular level at which this defect might occur has not been fully documented. We have investigated the kinetics of IFN-gamma, interleukin-2 receptor (IL-2 R), and interleukin-1 beta (IL-1 beta) messenger RNA (mRNA) expression in RA patients (n = 9) and normal controls (n = 5) after PHA leucocyte activation. We demonstrate here a significantly decreased expression of IFN-gamma mRNA in RA patients without modification of its kinetics associated with a similar IL-1 beta mRNA expression.

[Effect of growth hormone on the differentiation of chondrocytes from prepuberal rabbits in serum-free culture and on the radioimmunologic activity of Sm-C/IGF1 measured in the culture medium]. / Effet de GH sur la différenciation de chondrocytes de lapin prépubère en culture sans sérum et sur l'activité radioimmunologique Sm-C/IGF1 measurable dans le milieu de culture.

This study concerns the immunoreactive somatomedin C secretion by prepubertal rabbit epiphyseal chondrocytes cultured in a defined serum-free medium. In such culture conditions, chondrocytes mainly synthesized Type II collagen (80% of total collagen) during 10 days. A small amount of Type I collagen was also found with a significant (p less than 0.05) higher level during the period of cell multiplication (6.4 +/- 1.5%) than when cells reached confluency (0.9 +/- 0.2%). During the 10 days of culture without serum and without hormone added, a Sm-C/IGF1 activity was measured by RIA at a mean level of 30 +/- 5 mU/ml/10 micrograms DNA. This value was significantly higher (p less than 0.001) than in the medium not incubated with the cells (1.7 +/- 0.9 mU/ml). When hGH was added to the culture medium during the period of cell division, the level of Sm-C/IGF1 activity was significantly elevated at 39 +/- 4 mU/ml/10 micrograms DNA (p less than 0.05) and at 55 +/- 3 mU/ml/10 micrograms DNA (p less than 0.001) with 50 ng/ml and 100 ng/ml hGH concentrations respectively. On the contrary, no difference was observed at confluency in treated and non treated cells.