Olivier Schussler

Myocardial Assistance by Grafting a New Bioartificial Upgraded Myocardium (MAGNUM trial): clinical feasibility study.

BACKGROUND Cell transplantation for the regeneration of ischemic myocardium is limited by poor graft viability and low cell retention. In ischemic cardiomyopathy, the extracellular matrix is deeply altered; therefore, it could be important to associate a procedure aiming at regenerating myocardial cells and restoring the extracellular matrix function. We evaluated the feasibility and safety of intrainfarct cell therapy associated with a cell-seeded collagen scaffold grafted onto infarcted ventricles. METHODS In 20 consecutive patients presenting with left ventricular postischemic myocardial scars and indication for coronary artery bypass graft surgery, bone marrow cells were implanted during surgery. In the last 10 patients, we added a collagen matrix seeded with bone marrow cells, placed onto the scar. RESULTS There was no mortality and any related adverse events (follow-up 10 +/- 3.5 months). New York Heart Association functional class improved in both groups from 2.3 +/- 0.5 to 1.3 +/- 0.5 (matrix, p = 0.0002) versus 2.4 +/- 0.5 to 1.5 +/- 0.5 (no matrix, p = 0.001). Left ventricular end-diastolic volume evolved from 142.4 +/- 24.5 mL to 112.9 +/- 27.3 mL (matrix, p = 0.02) versus 138.9 +/- 36.1 mL to 148.7 +/- 41 mL (no matrix, p = 0.57), left ventricular filling deceleration time improved significantly in the matrix group from 162 +/- 7 ms to 198 +/- 9 ms (p = 0.01) versus the no-matrix group (from 159 +/- 5 ms to 167 +/- 8 ms, p = 0.07). Scar area thickness progressed from 6 +/- 1.4 to 9 mm +/- 1.1 mm (matrix, p = 0.005) versus 5 +/- 1.5 mm to 6 +/- 0.8 mm (no matrix, p = 0.09). Ejection fraction improved in both groups, from 25.3% +/- 7.3% to 32% +/- 5.4% (matrix, p = 0.03) versus 27.2% +/- 6.9% to 34.6% +/- 7.3% (no matrix, p = 0.031). CONCLUSIONS This tissue-engineered approach is feasible and safe and appears to improve the efficiency of cellular cardiomyoplasty. The cell-seeded collagen matrix increases the thickness of the infarct scar with viable tissue and helps to normalize cardiac wall stress in injured regions, thus limiting ventricular remodeling and improving diastolic function.

Systemic Inflammation, Nutritional Status and Tumor Immune Microenvironment Determine Outcome of Resected Non-Small Cell Lung Cancer

Background Hypothesizing that nutritional status, systemic inflammation and tumoral immune microenvironment play a role as determinants of lung cancer evolution, the purpose of this study was to assess their respective impact on long-term survival in resected non-small cell lung cancers (NSCLC). Methods and Findings Clinical, pathological and laboratory data of 303 patients surgically treated for NSCLC were retrospectively analyzed. C-reactive protein (CRP) and prealbumin levels were recorded, and tumoral infiltration by CD8+ lymphocytes and mature dendritic cells was assessed. We observed that factors related to nutritional status, systemic inflammation and tumoral immune microenvironment were correlated; significant correlations were also found between these factors and other relevant clinical-pathological parameters. With respect to outcome, at univariate analysis we found statistically significant associations between survival and the following variables: Karnofsky index, American Society of Anesthesiologists (ASA) class, CRP levels, prealbumin concentrations, extent of resection, pathologic stage, pT and pN parameters, presence of vascular emboli, and tumoral infiltration by either CD8+ lymphocytes or mature dendritic cells and, among adenocarcinoma type, tumor grade (all p<0.05). In multivariate analysis, prealbumin levels (Relative Risk (RR): 0.34 [0.16–0.73], p = 0.0056), CD8+ cell count in tumor tissue (RR = 0.37 [0.16–0.83], p = 0.0162), and disease stage (RR 1.73 [1.03–2.89]; 2.99[1.07–8.37], p = 0.0374- stage I vs II vs III-IV) were independent prognostic markers. When taken together, parameters related to systemic inflammation, nutrition and tumoral immune microenvironment allowed robust prognostic discrimination; indeed patients with undetectable CRP, high (>285 mg/L) prealbumin levels and high (>96/mm2) CD8+ cell count had a 5-year survival rate of 80% [60.9–91.1] as compared to 18% [7.9–35.6] in patients with an opposite pattern of values. When stages I-II were considered alone, the prognostic significance of these factors was even more pronounced. Conclusions Our data show that nutrition, systemic inflammation and tumoral immune contexture are prognostic determinants that, taken together, may predict outcome.

Catamenial pneumothorax: chest X-ray sign and thoracoscopic treatment

We report the case of a 25-year-old woman with recurrent right-sided catamenial pneumothorax. At thoracoscopy, the diaphragm presented several violet implants with holes. The presence of diaphragmatic endometrial implants was confirmed at pathologic examination. Re-review of the preoperative chest x-ray film showed 8 x 5 and 1 x 1 mm bubbles at the level of the right diaphragm associated with the homolateral pneumothorax, thus suggesting that passage of air from the genital tract through the diaphragm was responsible for the pneumothorax. This may further clarify the pathogenesis of catamenial pneumothorax which remains controversial in the literature.

Use of arginine–glycine–aspartic acid adhesion peptides coupled with a new collagen scaffold to engineer a myocardium-like tissue graft

Background Cardiac tissue engineering might be useful in treatment of diseased myocardium or cardiac malformations. The creation of functional, biocompatible contractile tissues, however, remains challenging. We hypothesized that coupling of arginine–glycine–aspartic acid–serine (RGD+) adhesion peptides would improve cardiomyocyte viability and differentiation and contractile performance of collagen-cell scaffolds.Methods Clinically approved collagen scaffolds were functionalized with RGD+ cells and seeded with cardiomyocytes. Contractile performance, cardiomyocyte viability and differentiation were analyzed at days 1 and 8 and/or after culture for 1 month.Results The method used for the RGD+ cell–collagen scaffold coupling enabled the following features: high coupling yields and complete washout of excess reagent and by-products with no need for chromatography; spectroscopic quantification of RGD+ coupling; a spacer arm of 36Å, a length reported as optimal for RGD+-peptide presentation and favorable for integrin-receptor clustering and subsequent activation. Isotonic and isometric mechanical parameters, either spontaneous or electrostimulated, exhibited good performance in RGD+ constructs. Cell number and viability was increased in RGD+ scaffolds, and we saw good organization of cell contractile apparatus with occurrence of cross-striation.Conclusions We report a novel method of engineering a highly effective collagen-cell scaffold based on RGD+ peptides cross-linked to a clinically approved collagen matrix. The main advantages were cell contractile performance, cardiomyocyte viability and differentiation.

Effect of human immunoglobulins on the immunogenicity of porcine bioprostheses

BACKGROUND Glutaraldehyde fixation (GT) is known to reduce immunologic reactions and tissue degeneration after implantation in humans. Sterilization after glutaraldehyde fixation (G-ST) improves the safety and reduces the tendency of GT valves to calcify. Intravenous immunoglobulins (IVIg) have been shown to reduce xenogeneic response against porcine tissue. We have investigated the effect of these fixation procedures combined with and without IVIg on the antigenicity of bioprostheses. METHODS Lewis adult rats were implanted subcutaneously with a fresh, GT, or G-ST porcine heart valve pre- or posttreated with different amounts of IVIg. We followed by enzyme-linked immunosorbent assay and IgM and IgG titers against protein extracts from the porcine heart valves after implantation. Cellular reactivity was assessed in xenogeneic lymphoendothelial coculture experiments. Calcification content was also examined. RESULTS Glutaraldehyde fixation partially decreased the humoral response against proteins of the implant but elicited a cellular xenogeneic response. Sterilization reduced these reactivities, but retained antigenicity. Intravenous immunoglobulin postincubated with GT valves before implantation reduced the antigenicity of the tissue to the same extent as G-ST valves, but had no effect on valvular tissue calcification. CONCLUSIONS Our studies demonstrate that IVIg or the sterilization procedure (ST) reduced the cellular response against glutaraldehyde-fixed valves (GT), whereas reduced calcification was observed only with ST.

A New Method for Detection of Post- Pneumonectomy Broncho-Pleural Fistulas

Broncho-pleural fistula is a relatively rare but life-threatening complication of pneumonectomy. Early detection of this complication is crucial for optimal treatment. We describe a simple technique to detect postpneumonectomy broncho-pleural fistula by measuring concentrations of O2 and N2O in the pneumonectomy cavity at baseline and after allowing patients to breath gas mixtures enriched with O2, N2O, or both. The technique was used in 22 patients. In 20 control patients the test was carried out 48 hours after pneumonectomy. Both the O2 and the N2O test were negative in all cases. However, in 2 patients with broncho-pleural fistula both the O2 and the N2O tests were positive.

Human Bone Marrow Contains Mesenchymal Stromal Stem Cells That Differentiate In Vitro into Contractile Myofibroblasts Controlling T Lymphocyte Proliferation

Mesenchymal stromal stem cells (MSC) that reside in the bone marrow (BM) can be amplified in vitro. In 2-dimension (D) cultures, MSC exhibit a morphology similar to fibroblasts, are able to inhibit T lymphocyte and natural killer cell proliferation, and can be differentiated into adipocytes, chondrocytes, or osteoblasts if exposed to specific media. Here we show that medullar MSC cultured in 2D formed an adherent stroma of cells expressing well-organized microfilaments containing α-smooth muscle actin and nonmuscle myosin heavy chain IIA. MSC could be grown in 3D in collagen membranes generating a structure which, upon exposition to 50 mM KCl or to an alternating electric current, developed a contractile strength that averaged 34 and 45 μN/mm2, respectively. Such mechanical tension was similar in intensity and in duration to that of human placenta and was annihilated by isosorbide dinitrate or 2,3-butanedione monoxime. Membranes devoid of MSC did not exhibit a significant contractility. Moreover, MSC nested in collagen membranes were able to control T lymphocyte proliferation, and differentiated into adipocytes, chondrocytes, or osteoblasts. Our observations show that BM-derived MSC cultured in collagen membranes spontaneously differentiate into contractile myofibroblasts exhibiting unexpected properties in terms of cell differentiation potential and of immunomodulatory function.

Cellular cardiomyoplasty for myocardial support and regeneration

SummaryBACKGROUND: Cell-based regenerative therapy is undergoing different experimental and clinical trials in order to limit the consequences of decreased contractile function and compliance of damaged ventricles following myocardial infarction. METHODS: An overview of the actual status quo. RESULTS: Over 200 patients have been treated worldwide with cell-based procedures for myocardial regeneration. Results are preliminary. CONCLUSIONS: Cellular cardiomyoplasty seems to reduce the size and fibrosis of infarct scars, limit postischemic remodelling, and restore regional myocardial contractility.ZusammenfassungGRUNDLAGEN: Die Regeneration von avitalem Myokard durch Zellimplantation gewinnt zunehmend an wissenschaftlichem Interesse. METHODIK: Myoblasten, mesenchymale und embryonale Stammzellen und andere Vorläuferzellen werden derzeit in verschiedenen experimentellen Settings untersucht. Ein Überblick über den Status quo wird dargestellt. ERGEBNISSE: Etwa 200 Patienten wurden mit verschiedenen Techniken behandelt. Derzeit können nur vorläufige Ergebnisse aufgezeigt werden. SCHLUSSFOLGERUNGEN: Die Idee, die Regeneration von geschädigtem Myokard durch Zellimplantation herbeizuführen, ist faszinierend. Verschiedenste Zelltypen werden in unterschiedlichen experimentellen Settings angewandt. Die zelluläre Kardiomyoplastie scheint die Größe und den Fibrosegehalt in postischämischen Narben zu reduzieren. Wie sich diese Therapiemöglichkeit entwickeln wird, kann derzeit noch nicht abgeschätzt werden