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Biomedical subjects

N Duedari

Publications and source records attributed to N Duedari.

53 records · Page 3Linked to original sources
PubMed1987

[Transfusion strategy for patients in therapeutic aplasia. Experience of the Henri Mondor Hospital apropos of 2 successive protocols].

Retrospective analysis of two transfusion protocols applied in our institution to the bone marrow transplanted patients was conducted. Granulocyte transfusions should be only proposed as a therapeutic treatment to patients with severe well documented bacterial infection resistant to an adapted antibiotherapy. Leukocyte-depleted blood products reduce the incidence of HLA-immunization but do not influence the frequency of CMV infections. Random single donor platelet concentrates (obtained by cytapheresis) could decrease the incidence of polyspecific HLA-antibodies in comparison with the use of random standard platelet concentrates. The best transfusion protocol should associate leukocyte-depleted blood products with transfusion of prophylactic single donor platelet concentrates. In our institution, this protocol is less expensive than the protocol with prophylactic white blood cell transfusions and has the same cost than other protocols using standard blood products.

Agranulocytosis↗
PubMed1987

T-cell depletion of bone marrow transplants: assessment of standard immunological methods of quantification.

The efficacy of bone marrow transplant (BMT) T-cell depletion for the prevention of acute graft-versus-host disease (GVHD) has been demonstrated in animal models and in clinical studies. The importance of T-cell depletion has to be evaluated with standardized methods suitable for routine purposes. We report herein an in vitro mature T-cell depletion using a cocktail of three monoclonal antibodies (CD2, CD5, and CD7) and baby rabbit complement in 38 histocompatibility leucocyte antigen (HLA)-identical BMT with no more than grade II acute GVHD. The T-cell depletion was quantified using three prestandardized immunological methods: immunofluorescence (IF) analysis, SRBC-rosetting assay, and PHA proliferation assay. A mean of 97.5% IF-assessed T-cell depletion was achieved in the 38 BMT. The immediate IF analysis using three distinct sets of anti-T-cell monoclonal antibodies allowed us to detect a mean of 1.2% residual T cells. The SRBC-rosetting assay was not useful to quantify T-cell depletion because no residual SRBC-rosette-forming cells could be detected in every case. The results of a prestandardized PHA-induced proliferation assay gave a mean 96.7% inhibition of proliferation, and they were correlated with the IF results although the IF threshold of detection was higher. From these data we conclude that our in vitro T-cell-depletion procedure is reproducible and that standardized simple immunological methods such as immediate immunofluorescence analysis and PHA proliferation assay provide good tools to assess a T-cell depletion effective in the prevention of acute GVHD.

Adolescent↗
PubMed1985

Acute promyelocytic leukemia in 57 previously untreated patients.

Fifty-seven patients in initial phase of acute promyelocytic leukemia (APL) were treated in the same department with heparin infusion, platelet transfusions, and two related induction regimens both including cytosine arabinoside and daunorubicin. Clinical and biological findings at presentation were studied. The complete remission (CR) rate was 53%. Twenty-seven patients (47%) died during the initial course of the disease, either before day 5 (early death [ED], n = 7) or after day 5 (death in aplasia [DA], n = 20). Most ED was due to intracerebral hemorrhage (6/7), especially when large hemorrhages had been seen on fundus oculi examination. Most DA was due to multivisceral failure (9/20). No correlation was found between initial disseminated intravascular coagulation (DIC) and death. However, the worsening of coagulation parameters during induction therapy, with or without initial DIC, significantly increased the occurrence of renal and respiratory failure which were particularly frequent during the first month. The median duration of survival was short (3.5 months) and the median duration of CR (11 months) was similar to that of other acute myeloid leukemias treated with the same regimens. The possible causes of the high mortality observed during the initial courses of APL and the possible benefit of a more graduate induction chemotherapy are discussed.

Acute Kidney Injury↗
PubMed1985

Acquired autoimmune thrombocytopenia after allogeneic bone marrow transplantation.

A 29-year-old man in remission from acute myeloblastic leukaemia was treated by chemoradiotherapy and transplantation of bone marrow (BMT) collected from his HLA identical brother. Engraftment was documented on D12. Transient acute GVHD (grade II) appeared from D34. No infection complicated the BMT. Nevertheless severe thrombocytopenia persisted and was unresponsive to marrow donor platelet transfusion. The platelet immunofluorescence test demonstrated the autoimmune basis of the thrombocytopenia. This study suggests that the transient immune imbalance observed in the early post graft period could facilitate the appearance of autoimmune cytopenias.

Adult↗
PubMed1984

High dose intravenous gammaglobulin and platelet transfusions in leukaemic HLA-immunized patients.

3 aplastic patients with acute leukaemia, strongly HLA-immunized and refractory to platelet transfusions, received polyvalent gammaglobulin i.v. infusions (0.4 g/kg/d for 5 or 6 d) in association with daily random platelet transfusions. Platelet recovery was obtained in 2 patients. The 3rd patient did not show any significant rise in platelet count. The ability of gammaglobulin to prolong the life-span of incompatible transfused platelets could facilitate the management of HLA-immunized patients.

Adult↗
PubMed1984

[Autoimmune thrombopenic purpura and pregnancy. Absence of thrombopenia in the newborn infant despite the presence of circulating IgG auto-antibody in the mother].

Many pregnant women with AITP bear children with transient thrombocytopenia which is a potentially life threatening complication. Previous reports have demonstrated that monitoring of IgG circulating platelet antibodies may help with the management of these women. We report the case of a pregnant woman with AITP whose sera contained an IgG auto antiplatelet demonstrated by the fluorescein labelled antiglobulin techniques. Steroids had a beneficial effect with a return to a normal of the mother's platelet count but with no disappearance of the circulating antibody. Surprisingly the neonatal platelet count was normal and studies in the baby showed that the antibody had not crossed the placenta in detectable amounts. This case demonstrates our current inability to predict fetal thrombocytopenia and plan the mode of delivery.

Autoimmune Diseases↗
PubMed1982

[Red cell preservation by freezing at -25 degrees C].

A method of red cell preservation by freezing at -25 degrees C is described. Glycerol is added to the red blood cells in the primary polyvinyl chloride plastic collection bag to achieve a concentration of 28 pr cent (W/V). The blood cells are concentrated by centrifugation and the supernatant glycerol is discarded. Glycerolized red cells are frozen and stored at -25 degrees C for 1 to 6 months. After thawing, Sodium chloride solutions are used to wash the red cells in the IBM Blood Processor 2991. The following parameters have been investigated before freezing, after thawing and washing and after storage of red blood cells at 4 degrees C for 24 hours: --Hemoglobin level --leukocytes and platelets --amount of 2-3 DPG and ATP. Preliminary data show that the in vitro quality of erythrocytes stored at -25 degrees C is well preserved for 4 months and that this simple method can be applied to blood preservation in any Blood Center.

Adenosine Triphosphate↗
PubMed1978

The antigen Duclos. A new high frequency red cell antigen related to Rh and U.

An antibody is described which defines a new high frequency red cell antigen, Duclos, whose expression seems to require the presence of both U and Rh fundamental antigens. Apart from the antibody maker's own red cells the only nonreactive samples were from Rhnull U impaired individuals, one example of which was shown however to yield very slight amounts of antibody through absorption-elution tests. Rhmod U weak cells gave very depressed and Rhnull U positive or Rh common U negative cells moderately depressed reactions. The proposita's red cells had an apparently normal Rh-LW condition but their U antigen was significantly decreased. No further Duclos negative individual was found by screening 8,500 blood donors in the Paris area.

Aged↗
PubMedDate not supplied

Separation of large quantities of mononuclear cells from human blood using a blood processor.

A blood processor (IBM 2991) was used to separate lymphocytes from large volumes of blood. The procedure included the centrifugation of 200 ml whole blood on a density gradient. The results of this procedure were compared with those obtained with a manual procedure. Mononuclear cell (MNC) viability was preserved well in the two methods. But with the processor, recovery of MNC was better (63.5 +/- 2.5%) than with manual separation (26.5 +/- 4.1%). Monoclonal antibodies were used to identify the various cell subsets in the MNC fractions. No particular cell selection was observed when MNC fractions were obtained by the separator. In conclusion, the use of a cell separator provided an efficient technique for rapid isolation of large quantities of lymphocytes.

B-Lymphocytes↗
PubMedDate not supplied

Apheresis experience with a continuous flow cell separator.

The Dideco Vivacell separator is a continuous-flow centrifugation system that has only recently been used for cytapheresis. The authors' experience with this separator in 451 plateletpheresis and 164 leukapheresis procedures is presented. Platelet collection provided high platelet yields (9.53 +/- 2.85 X 10(11) with a collection efficiency of 74 +/- 14 percent for about 6 liters of total blood processed. Functional integrity was confirmed by normal in vitro tests (aggregation and response to hypotonic stress) and good in vivo recovery (55%). In leukapheresis, white cell yields were high (3.42 +/- 1.2 X 10(10) with 85 percent polymorphonuclear neutrophil cells. Their oxidative metabolism functions (generation of free oxygen radicals), investigated by chemiluminescence, were increased over donor values. Donor reactions, all of the mild citrate type, were rare.

Blood Component Removal↗
PubMedDate not supplied

Peripheral blood stem cell collection with a blood cell separator.

Forty-three patients with malignant nonmyeloid diseases underwent peripheral blood stem cell collections on an apheresis system (Spectra, COBE BCT, Lakewood, CO). Collections took place during the white cell (WBC) recovery phase following conditioning chemotherapy. One hundred two procedures were done after chemotherapy alone, and 72 procedures after chemotherapy plus granulocyte-colony-stimulating factor (G-CSF). Four centrifugal separation factors were tested. One and one-half patient blood volumes were processed in each procedure. The mean volume of the collected component was 158 +/- 16 mL. After chemotherapy alone, the procedures provided a mean of 0.8 x 10(8) WBCs per kg and 2.3 x 10(4) colony-forming units-granulocyte macrophage (CFU-GM) per kg of recipient body weight. The mononuclear cell percentage in the components increased with the centrifugal separation factor from 85 to 96 percent. In parallel, platelet contamination increased from 2.1 to 3.8 x 10(11). The collect hematocrit ranged from 1.0 to 2.5 percent (0.01-0.025). The collection efficiency for mononuclear cells and CFU-GM also increased with the centrifugal separation factors from 52 to 70 percent for mononuclear cells and from 55 to 68 percent for CFU-GM. Collections performed after G-CSF-stimulated mobilization were characterized by a higher neutrophil contamination independent of centrifugal separation factor, which gave a mean mononuclear cell percentage of 64 percent in the collected component. The average yield for these procedures was 2 x 10(8) WBCs per kg and 28 x 10(4) CFU-GM per kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗