Vascular smooth muscle differentiation of murine stroma: a sequential model.

Previous studies by our group showed that stromal cells from human long-term marrow cultures were mesenchymal cells following a vascular smooth muscle pathway. The present study using 58 immortalized stromal lines from different hematopoietic sites was conducted to verify whether this hypothesis also held true for murine stroma. Principal components analysis performed using cytoskeletal and extracellular matrix proteins allowed the segregation of five factors explaining more than 70% of the variance.

Severe pulmonary hypertension in histiocytosis X.

Diminished exercise capacity in advanced pulmonary histiocytosis X does not appear to be related to ventilatory limitation but may be related to pulmonary vascular dysfunction. Pulmonary hemodynamics and respiratory function were studied in 21 consecutive patients with advanced pulmonary histiocytosis X, and compared with parameters of patients with other severe chronic lung diseases (29 patients with chronic obstructive pulmonary disease and 14 patients with idiopathic pulmonary fibrosis). All patients with pulmonary histiocytosis X displayed severe pulmonary hypertension: mean pulmonary arterial pressure, 59 +/- 4 mm Hg; cardiac index, 2.

In vivo regulation of von willebrand factor synthesis: von Willebrand factor production in endothelial cells after lung transplantation between normal pigs and von Willebrand factor-deficient pigs.

To evaluate the regulation of plasma von Willebrand factor (vWF) and its in situ production by endothelial cells (ECs), 12 swine leukocyte antigen (SLA)-compatible left lung transplantations were performed. Normal lungs were transplanted into 10 pigs homozygous for von Willebrand disease and into 2 normal pigs. Additionally, 1 normal pig underwent pneumonectomy, and 1 SLA-incompatible lung transplantation between normal pigs was performed.

Detection of intracellular cytokines in citrated whole blood or marrow samples by flow cytometry.

We have used three-color flow cytometric analysis for the detection of intracellular cytokines (IFN-gamma and IL-4) in CD3(+) cells, after stimulation for 4 h with phorbol 12-myristate 13-acetate (PMA) and ionomycin in the presence of monensin. We report in the present paper a validation study for analysing IFN-gamma and IL-4 production by bone marrow (BM)-derived T cells and peripheral blood T cells after BM transplantation. Using citrate as anticoagulant for blood and marrow sampling interfered with PMA+ionomycin-based cell stimulation.

[Transfusion medicine in adults. Perspectives].

ENHANCED SURVEILLANCE: Safety in transfusion medicine involves all the different procedures designed to guarantee safe transfusion in accordance with standards established on the current scientific knowledge. It is thus crucial to continuously monitor scientific advances in order to transfer progress in fundamental research as rapidly as possible to transfusion applications and thus maintain the highest level of safety. RISK REDUCTION: The risk of residual viral contamination might be additionally reduced by the introduction of genomic screening.

[Monitoring and secondary effects of transfusion of labile blood products].

VIRUS RISKS: Since 1991, the medical community has focused what can be termed transfusion phobia on transmissible viral diseases. Such diseases do not however reflect the overall risk of transfusion. The residual virus risk is the risk of not detecting a viral disease in the donor population which is transmissible by blood or blood products.

[Indications and utilization of labile blood products].

FUNDAMENTAL PRINCIPLES: Rigorous prescription of labile blood products is a fundamental step in assuring safe transfusion. The clinician must avoid all unnecessary transfusions and choose the most adapted blood product to meet the patient's clinical requirements. TRANSFUSION THERAPY: The patient's immunological situation, past history, prognosis, and potential need for future transfusions must be taken into account in a global approach aimed at determining which transfusion product is most adapted for each individual patient.

[Mode of preparation of labile blood products--available products].

LABILE BLOOD PRODUCTS: Labile blood products are therapeutic products produced from blood which do not have the characteristics of drugs. This category of products include packed red cells, platelets as well as white cell concentrates and frozen fresh plasma. PACKED RED CELLS AND PLATELET CONCENTRATES: These products used to be prepared from total blood.

Screening of five specific cell cycle inhibitors using a T cell lymphoma cell line synchrony/release assay.

To obtain different cell populations at specific cell cycle stages, we used a cell culture synchronization protocol. Effects of five different cell cycle inhibitors acting throughout the cell cycle were examined by DNA flow cytometric analysis of a synchrony/release lymphoma cell line (CEM). The screening synchronized protocol showed that staurosporine, mimosine and aphidicolin are reversible G1 phase inhibitors that act at different times.

Low dose T-cell lymphocyte infusion combined with marrow T-cell depletion as prophylaxis of acute graft vs host disease for HLA identical sibling bone marrow transplantation.

T-cell depletion (TCD) of the bone marrow graft remains the most effective method to prevent severe graft versus host disease after allogeneic bone marrow transplantation. Early studies of HLA-identical sibling transplants showed that although T-cell depletion decreased GVHD, T-cell depleted transplants had higher risks of graft failure and leukemia relapse, leukemia free survival (LFS) was not improved compared to non-T-cell depleted transplants. In order to avoid graft failure and increased risk of relapse associated with this approach, we initiated a pilot study of T-cell depletion of the marrow graft combined with reinfusion of a fixed quantity of CD2+ peripheral blood T-cells.

Antibodies to human adhesion molecules and von Willebrand factor: in vitro cross-species reactivity in the xenotransplantation setting.

Endothelial cell activation is thought to play an important role in xenograft rejection through cell retraction and expression of pro-coagulant and pro-inflammatory factors. Identification of antibodies recognizing porcine endothelial molecules would be useful to study and manipulate the inflammatory response to a xenograft. The aim of this study was to investigate the cross-reactivity of antibodies directed against human adhesion molecules and von Willebrand factor (vWF).

Pulmonary thromboendarterectomy for chronic thromboembolic obstruction of the pulmonary artery in piglets.

Objective: The 2 main causes of death after thromboendarterectomy for chronic pulmonary thromboembolism are incomplete repermeabilization responsible for persistent pulmonary hypertension and acute high-permeability pulmonary edema. We wish to establish an experimental model of chronic pulmonary thromboembolism to replicate the conditions encountered during and after pulmonary thromboendarterectomy.

Methods: Multiple-curled coils and tissue adhesive were embolized in 6 piglets to induce complete obstruction of the left pulmonary artery, documented by angiography.

Vascular endothelium viability and function after total cardiopulmonary bypass in neonatal piglets.

Endothelium dysfunction with severe pulmonary hypertension may occur after total cardiopulmonary bypass (CPB) in infants as a result of a widespread inflammatory response. The aim of this study was to separate out the effects of lung ischemia-reperfusion from membrane oxygenator-induced activation of leukocytes on the function and viability of the pulmonary and systemic endothelia in neonatal piglets submitted to 90-min total CPB followed by 60-min reperfusion or in sham animals. Hemodynamics, gas exchange, endothelial-dependent relaxation in pulmonary and femoral arteries, and lung and skeletal muscle myeloperoxidase activity were assessed before, during, and after CPB, i.

Reverse ventilation-perfusion mismatch in lung cancer suggests intrapulmonary functional shunting.

We report on a patient with squamous cell cancer of the left lung who was first considered ineligible for surgery because of severe hypoxemia. A ventilation-perfusion scan showed "reverse" ventilation-perfusion mismatch, with 20% of the total lung perfusion going to the left lung, which showed no ventilation with radioactive aerosols. This pattern suggested that the hypoxemia was due to intrapulmonary functional shunting and could therefore be improved by surgical resection of the tumor.

Primary pulmonary hypertension associated with the use of fenfluramine derivatives.

Fenfluramine derivatives (Fds) are a well-established risk factor for primary pulmonary hypertension (PPH). We compared 62 Fd-PPH patients (61 women) evaluated in our center between 1986 and 1997 with 125 sex-matched PPH patients nonexposed to Fd referred during the same period (control PPH). In the Fd-PPH group, 33 patients (53%) used dexfenfluramine alone, 7 patients (11%) used fenfluramine alone, and 5 patients (8%) used both drugs.

Inhaled nitric oxide as a screening agent for safely identifying responders to oral calcium-channel blockers in primary pulmonary hypertension.

In a subset of patients with primary pulmonary hypertension (PPH), high doses of oral calcium-channel blockers (CCB) produce a sustained clinical and haemodynamic improvement. However, significant side-effects have been reported during acute testing with CCB. Therefore, to identify accurately patients who may benefit from long-term CCB therapy, there is a need for a safe, potent and short-acting vasodilator.

Impaired renal graft survival after a positive B-cell flow-cytometry crossmatch.

Background: The clinical and immunological relevance of a positive B-cell flow-cytometry (B-FCXM) crossmatch in renal transplantation is still controversial.

Methods: We retrospectively analysed 145 consecutive cadaveric renal transplantations performed from May 1991 to September 1995 in our institution. All grafts were transplanted following a negative IgG T-cell complement-dependent cytotoxicity crossmatch (T-CDCXM).

Gene therapy for oxidant injury-related diseases: adenovirus-mediated transfer of superoxide dismutase and catalase cDNAs protects against hyperoxia but not against ischemia-reperfusion lung injury.

Hyperoxia and ischemia-reperfusion cause profound lung cellular damage mediated, in part, by generation of oxygen radicals. We hypothesized that gene therapy can be used to overcome oxidant injury by augmenting intracellular antioxidant enzymes. Adult rats were injected intratracheally with an adenovirus (Ad) vector encoding human superoxide dismutase (CuZn-SOD) or catalase cDNA, a mixture of both Ad vectors, or a control Ad vector containing no exogenous gene.

Pulmonary vascular disorders in portal hypertension.

The wide spectrum of pulmonary vascular disorders in liver disease and portal hypertension ranges from the hepatopulmonary syndrome characterized by intrapulmonary vascular dilatations, to pulmonary hypertension (portopulmonary hypertension), in which pulmonary vascular resistance is elevated. Since hepatopulmonary syndrome and portopulmonary hypertension have been reported in patients with nonhepatic portal hypertension, the common factor that determines their development must be portal hypertension. The clinical presentations are very different, with gas exchange impairment in the hepatopulmonary syndrome and haemodynamic failure in portopulmonary hypertension.

In vivo alloreactive potential of ex vivo-expanded primary T lymphocytes.

Background: We are presently investigating the therapeutic potential of herpes simplex-thymidine kinase-expressing donor T cells in the setting of a T cell-depleted allogeneic bone marrow transplantation. The generation, expansion, and selection of the gene-modified T cells require a 12-day ex vivo culture period in high-dose interleukin (IL)-2 that could significantly alter their in vivo alloreactivity.

Methods: We evaluated the alloreactive potential of such cultured cells in a murine allogeneic bone marrow transplantation model.