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Biomedical subjects

J M Bidet

Publications and source records attributed to J M Bidet.

At least 19 recordsLinked to original sources

Collagen matrix: an attractive alternative to agar and methylcellulose for the culture of hematopoietic progenitors in autologous transplantation products.

Autografts using untreated or in vitro manipulated bone marrow and peripheral blood stem cells represent promising approaches to the treatment of malignant diseases. In this work, the collagen gel culture technique was compared with agar and methylcellulose for its capacity to permit the growth of human granulomonocytic (day 14 CFU-GM; collagen vs agar or MTC) or erythroblastic (day 7 CFU-E and day 14 BFU-E; collagen versus methylcellulose) colonies in autologous transplantation products. Our results show that the collagen culture system always gave as many or more colonies than the other techniques. It also allowed harvesting of gels onto glass slides and subsequent May-Grünwald-Giemsa, cytochemical or immunocytochemical staining. We suggest that the collagen assay represents an interesting alternative to the widely used agar or methylcellulose systems for the culture of hematopoietic progenitors because of the equal or higher number of colonies detected, the easy phenotypical identification of colonies in stained gels, and the ability to store high-quality documentation. This technique is particularly attractive for use in the quality control of autologous bone marrow transplantation procedures.

Agar

Seropositivity to hepatitis C virus in Tunisian haemodialysis patients.

The prevalence of anti-hepatitis C virus (anti-HCV) antibodies and of hepatitis B markers (HBs antigen, anti-hepatitis B core antigen) was assessed in 63 haemodialysis patients from the Tunisian Sahel. As measured by second generation ELISA assays (Ortho and Organon), the frequency of anti-HCV antibodies was 42% (27/63), while 4 patients (6.3%) were HBs Ag positive and 30 (47.6%) anti-HBc positive. Anti-HCV seropositivity was significantly correlated with duration of dialysis (p = 0.007) and number of blood transfusions (> 10 units, p = 0.0004). Among 12 subjects with a history of abnormal ALAT levels, 10 were anti-HCV positive (p = 0.0016) and the results suggest hepatitis C viral infection to be the main cause of liver disease in haemodialysis patients in Tunisia.

Adolescent

[Allergic reactions to transfusion].

Frequent allergic reactions following transfusion are observed. Usually, they are benign but sometimes we observe severe allergic reactions. Adverse reactions may be brought about by least two mechanisms. First, immediate-type hypersensibility reactions due to IgE. Secondly, anaphylactic-type reactions due to interaction between transfused IgA and class specific anti IgA in the recipient's plasma. They are characterized by their severest form (anaphylactic shock). The frequency of severe reactions following the transfusion blood plasma is very low. These transfusion reactions are complement-mediated and kinins-mediated. Prevention of allergic reactions is necessary among blood donors and recipients.

Anaphylaxis

[Initial personal results of a technic of removing leukocytes by filtration on cotton fibers (Imugard Ig 500, Terumo)].

The technical parameters of blood filtration through cotton Imugard IG 500 filters were evaluated. Sixty units of red cell concentrates were filtered. The mean value of the residual leukocytes indicated a leukocyte depletion greater than 98%, disregarding the unit age and the filtration temperature. The number of residual leukocytes was below 1 X 10(8) in 94% of the filtered units and less than 0.3 X 10(8) in 68%. The number of residual platelets was less than 1 X 10(10) in 92% of these units.

Blood Platelets

Filtration pressure and red blood cell deformability: evaluation of a new device: erythrometre.

The authors have tested a new device that records the filtration pressure of a suspension of red blood cells (R.B.C.) passing through a 3 micron pore diameter filter. As the flow rate is constant, the pressure increase allows to appreciate an index of the R.B.C. deformability. In order to test the performances of this new equipment, the authors have studied the influence of the variation of the following parameters. Haematocrit from 0.5 to 2%, Buffer composition; time elapsing from drawing to measurement: from hour 0 to hour 3. This analysis has been performed on donors; on packed red cells preserved in CPD, from D0 to D21 and on patients specimens and the results have been compared to the whole blood filtration according to the Reid and Dormandy method. The following parameters were simultaniously measured: Whole blood viscosity by means of a Low Shear 30 viscosimeter, Intraerythrocyte ATP by bioluminescence, Membrane lipid composition (cholesterol, phospholipids), Scanning electron microscopy. This new apparatus, measuring the filtration pressure seems to be a more sensitive and reproductible method allowing to approach the RBC deformability, and quite usefull in clinical haemorheology.

Erythrocytes

[Changes in the electric charge of blood lymphocyte populations after secondary immunization with tetanus antitoxin in man].

The electrophoretic mobility of circulating lymphocytes has been studied in normal human subjects after immunization by tetanus toxoid. The mean migration speed was shown to increase, particularly two and three days after secondary immunization. This increase appeared to be due to the elevation of percentage of T cells migrating at 1.20 and 1.35 micrometer. sec.-1v.-1 cm. (active rosettes-forming cells), with a decrease of the percentage of B cells and T lymphocytes migrating at 1.10 micrometer. sec.-1v.-1 cm. The return to the anterior status was observed between day 4 and 8 after immunization.

Electrophoresis

[Electrophoretic mobility of human lymphocytes purified by nylon columns and spontaneous rosettes].

Cell electrophoresis enables the separation of the lymphocytes in normal human blood into two principal groups, as a function of their migration speed in relation to 1 mum.sec -1..v-1.cm. In 42 healthy adults, 19,9 % of the lymphocytes have a slower migration, and 80,1 % a faster migration than the reference speed. Two known methods are used for the selection of the lymphocytic populations : spontaneous rosetting with sheep red blood cells, a property of the T lymphocytes, and the adherence to nylon wool columns, which is dominant in the case of B lymphocytes. The cells which do not form spontaneous rosettes, and the cells adhering to nylon wool columns have above all a slow migration. On the contrary, cells which do not adhere to nylon columns have a fast migration. These arguments are in favour of the T nature of the rapid migrating lymphocytes, and of the B nature of the slow migrating lymphocytes.

Adolescent

Electrophoretic mobility of blood lymphocytes in cancer patients.

Determination of electrophoretic mobility of lymphocytes in 70 cancer patients shows a significant decrease of the fast moving cells. It seems to be a relation between the percentage or absolute number of the rapid lymphocytes and dissemination and prognosis of the disease. This decrease is in agreement with the variations of the T lymphocyte population described in cancer patients with other methods. On the contrary, although there is reduction of total blood lymphocytes, the number of slow moving cells is not reduced. The changes observed in mean migration speed of fast and slow migrating lymphocytes could indicate more selective alterations in some cell subpopulations.

Adult