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Biomedical subjects

J J Fournel

Publications and source records attributed to J J Fournel.

32 records · Page 2Linked to original sources
PubMed1990

Ultraviolet irradiation of platelet concentrates: feasibility in transfusion practice.

Ultraviolet (UV)-B irradiation abolishes lymphocyte functions (the ability to respond and to stimulate) in mixed lymphocyte culture (MLC). This effect may have practical application in the prevention or reduction of transfusion-induced alloimmunization against HLA class I antigens. To study this, platelet concentrates (PCs) were obtained with a cell separator, suspended in autologous plasma in a final volume of 400 mL, and transferred into a large (22 X 30 cm) cell culture bag. This plastic showed a good transmittance of UV-B rays at 310 nm (54%). PCs were placed between two quartz plates (surface of irradiation = 25 X 37 cm), and the two sides were irradiated simultaneously. Energy delivered to the surface of the plastic bag was automatically monitored. The ability to respond (in MLC and to phytohemagglutinin) and to stimulate allogeneic lymphocytes was completely abolished with energy of 0.75 J per cm2 (irradiation time less than 3 min). The temperature increase during irradiation was negligible. Platelet aggregation (collagen, adrenalin, ADP, arachidonic acid, ristocetin) was not impaired if UV-B energy was below 3 J per cm2. Recovery and survival of autologous 111In-labeled platelets were studied in four volunteers; no differences were found between UV-B-treated (1.5 J/cm2) platelets and untreated platelets. These results show that a large-scale clinical trial using UV-B-irradiated PCs to prevent HLA alloimmunization is feasible.

Blood Platelets↗
PubMed1989

Human immunodeficiency virus-specific cytotoxic responses of seropositive individuals: distinct types of effector cells mediate killing of targets expressing gag and env proteins.

By using target cells that expressed isolated env, gag, p27nef, or p23vif molecules introduced by recombinant vaccinia viruses containing genes encoding these polypeptides, it was possible to identify env, gag, p27nef, and p23vif as cytolytic target antigens for freshly isolated blood cells from human immunodeficiency virus 1 (HIV-1) seropositive patients. Most of the patients tested (95%) manifested a specific cytotoxic activity against vaccinia virus-env-infected target cells. The env-specific cytotoxic activity was not restricted by the major histocompatibility complex and was not mediated by T lymphocytes, as shown by the absence of blocking effect with an anti-CD3 monoclonal antibody and by the inefficiency of CD3+, CD8+, or CD4+ and CD8+ depletion to reduce the cytotoxic activity against the env-expressing target cells. In the same conditions, the cytotoxic activity specific for gag was abrogated and gag major histocompatibility complex-restricted cytotoxic T lymphocytes were detected in 85% of the subjects tested. Therefore, in a HIV-1 seropositive subject, distinct types of effector cells mediate the lysis of target cells expressing gag and env proteins.

Antibodies, Monoclonal↗
PubMed1989

[Systematic peroperative use of an autotransfusion system in heart surgery. A prospective and comparative study in 283 patients].

A series of 283 patients undergoing cardiac bypass surgery was studied to determine whether intraoperative autotransfusion, haemodilution, and a change in transfusion techniques of the same surgical team could reduce homologous blood requirements. The Cell-Save Haemonetics* system was used systematically in 167 consecutive patients (Group I). This group of autotransfused patients was analysed prospectively and compared with a control group (Group II) of 116 patients operated one year before and analysed retrospectively. During the whole hospitalisation, homologous blood products were required in 40.7% of patients in Group I compared with 73.3% of patients in Group II (p less than 0.0001). The average requirements of packed cells per patient were 2.7 +/- 1.3 in Group I compared with 4.1 +/- 2.5 in Group II (p less than 0.0001). The haematocrit on discharge from the department was 29.9 +/- 4% in Group I compared with 32 +/- 4.5% in Group II (p less than 0.0001). The average volume of blood recovered by the system and then autotransfused was 620.8 +/- 242.6 ml. There was no significant difference in postoperative bleeding in the first 24 hours between the two groups. This study confirms that peroperative autotransfusion during cardiac surgery and the acceptance of a clinically well tolerated normovolumic anaemia are associated with a significant reduction in homologous blood consumption.

Adult↗
PubMedDate not supplied

Screening blood donations for hepatitis C in Central Africa: analysis of a risk- and cost-based decision tree.

Four screening strategies (no testing, HC Abbott, HC Pasteur, and a combined test) for the detection of hepatitis C virus (HCV) antibody in donated blood were considered in a formal decision tree. Decision criteria included residual risk of infection and overall monetary cost. Tree parameters were determined using data from the Central African Republic. The prevalences observed among blood donors for HIV infection, hepatitis B, syphilis, and hepatitis C varied between 6% and 15%. The current residual risk of transfusion-transmitted infections is very high (8.4%). Screening for HCV would bring that risk down to about 3% with either the HC Pasteur, the HC Abbott, or the combined test. Even though baseline analysis gives preference to the HC Abbott test (the combined test coming out last), Monte Carlo sensitivity and uncertainty analyses showed that Abbott's and Pasteur's tests are interchangeable, on the basis or either risk or cost considerations.

Blood Donors↗