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Biomedical subjects

P Fondu

Publications and source records attributed to P Fondu.

At least 55 records · Page 3Linked to original sources
PubMed1992

Bone marrow transplantation for severe sickle cell anaemia.

Five children with sickle cell anaemia underwent bone marrow transplantation (BMT) for severe clinical disease. The conditioning regimen for BMT was in busulfan plus cyclophosphamide. The allograft contained more than 5 x 10(8) nucleated cells per kg recipient. Prophylaxis of GVHD consisted of methotrexate and cyclosporin A. Therapy was well tolerated. Duration of neutropenia (less than 0.5 x 10(9)/l) was short (14-25 d). Platelet recovery (greater than 50 x 10(9)/l) occurred between day 12 and 45. The patients have been followed up for 8-28 months. No major infections occurred and long-term BMT-related toxicity was limited to mild, chronic GVHD in one patient. Mean haemoglobin levels remained above 10 g/dl. Haemoglobin electrophoresis showed AS patterns in all grafted patients--all marrow donors having sickle cell trait. From our preliminary data, we conclude that BMT or sickle cell anaemia is curative, well tolerated and should be proposed for suitable patients.

Anemia, Sickle Cell↗
PubMed1992

[Indications for bone marrow graft in severe hemoglobinopathies].

Allogenic bone marrow transplantation (ABMT) is the only curative approach for sickle cell anemia and major beta-thalassemia. In sickle cell anemia, ABMT can be proposed for severe clinical disease. In major beta-thalassemia, it must be proposed to young patients who have an HLA identical familial donor.

Anemia, Sickle Cell↗
PubMed1992

Performance of an immunoradiometric assay of erythropoietin and results for specimens from anemic and polycythemic patients.

We evaluated a new commercially available two-site immunoradiometric assay (IRMA; BioMérieux 125I-EPO CoatRIA) for erythropoietin (EPO) in human serum. The precision (CV) was 4.1% intra-assay and 8% interassay for a serum pool with an EPO concentration of 17 int. units/L; the detection limit was 0.5 int. unit/L, one order of magnitude lower than by classical radioimmunoassay (RIA), although standardization of IRMA and RIA were similar. Results by both IRMA and RIA are compared for normal subjects, patients with nonrenal noninflammatory anemias, patients with beta-thalassemia major, hemodialysis patients, and patients with primary or secondary polycythemia. Values by IRMA compared well with those by RIA in the upper area of the range; IRMA and RIA values for EPO show parallel expected variations with the degree of anemia. However, because of its greater sensitivity and specificity, we consider the IRMA more appropriate than RIA for investigating patients with sub-normal EPO concentrations.

Adolescent↗
PubMed1991

Anticardiolipin antibodies (ACA) are most often not associated with lupus-like anticoagulant (LLAC) in human immunodeficiency virus (HIV) infection.

Anticardiolipin antibodies (ACA) and lupus-like anticoagulant (LLAC) have been studied in a group of 142 non-hospitalized and a group of 72 hospitalized HIV infected patients. We observed a variable frequency of ACA positivity ranging from 7.7% to 30.3% according to the groups of patients and the isotype of immunoglobulin fraction containing ACA activity. None of the patients investigated presented a prolongation of the activated partial thromboplastin time (APTT) compatible with the presence of a LLAC. Some patients presented a weak anticoagulant activity only detected by the tissue thromboplastin inhibition (TTI) test. No positive correlation was found between this latter test and ACA. We conclude that, like in syphilitic patients, ACA present in HIV infected patients are most often not associated with LLAC.

Antibodies↗
PubMed1991

In vivo inhibition of granulopoiesis in acute inflammation requires T lymphocyte integrity.

In previous studies, we have shown that mice undergoing an inflammatory reaction induced by subcutaneous (s.c.) implantation of copper rods elaborate humoral factors that initially enhance, and subsequently inhibit, diffusion chamber (DC) granulopoiesis. In order to quantify the inhibition of DC granulopoiesis after inflammation, one to three copper rods were implanted s.c. either at the same place (1 abscess), or at different sites (multiple abscesses). There was an inverse relationship between the increase in the number of abscesses, and the number of DC granulocytic cells measured in the inhibitory phase. To investigate the role of T lymphocytes in the release of putative inhibitory factor(s) that act on DC cells, cyclosporin A (CyA), a T lymphocyte function inhibitor, was given orally each day (0.75 mg) to mice, starting two days before copper implantation. CyA abrogated the inflammation-related inhibition on DC spleen colony-forming units (CFU-s), granulocyte-macrophage colony-forming units (CFU-gm), and total cell production. To confirm these results, DC were implanted in T cell deficient nude mice where no inhibition of DC cells was observed after inflammation. In conclusion, our data suggest that the in vivo inhibition of granulopoiesis is related to the level of the inflammatory stimulus and requires the functional integrity of T cells.

Acute-Phase Reaction↗
PubMed1991

In vitro and in vivo evaluation of two factor VIII concentrates virally inactivated by solvent-detergent or by pasteurization.

The present study compares two new factor VIII preparations currently used in the treatment of haemophilia. A Factor VIII was partially purified from plasma obtained from unpaid voluntary Belgian donors in the blood transfusion centers of Lille and Amsterdam and virus-inactivated by exposure to solvent-detergent (FVIII-SD) or by pasteurization (FVIII-P) respectively. The factor VIII content and the purity of both preparations were assessed in vitro, whereas in vivo we studied the recovery and the plasma half-life of both concentrates. The higher purity of FVIII-SD was confirmed. Factor VIII-P preparations contained more factor VIII than mentioned on the label. Both preparations gave good in vivo recoveries and half-lives. Patients who did not have antibodies to hepatitis B, hepatitis C or HIV at the initial screening, remained negative after six months treatment with the new concentrates. No patients developed neutralizing factor VIII antibodies. Furthermore patients appreciated the ease of administration of both preparations. In conclusion both FVIII concentrates are suited for the treatment of haemophilia A patients.

Antibodies, Viral↗
PubMed1991

In vivo regulation of granulocyte production in acute inflammation.

In order to study in vivo the enhanced granulopoiesis that occurs during acute inflammation, 1-3 sterile metallic copper rods were inserted subcutaneously into mice either at the same place (one abscess) or at different sites (multiple abscesses). Diffusion chambers filled with bone marrow cells were implanted intraperitoneally for 3 days. When a single abscess was created, the granulocytic content of the diffusion chamber increased similarly whatever the number of inserted copper rods. However, there was a direct relationship between the number of abscesses and the number of granulocytic cells harvested from the diffusion chambers. In order to investigate the role of T-lymphocytes in the production of diffusible stimulating factors that act on diffusion chamber granulopoiesis, cyclosporin A (CyA) was given to the mice with implanted copper rods. CyA abrogated the induced enhancement of CFU-S, CFU-GM and mature granulocyte numbers inside the diffusion chamber. The stimulatory effect of inflammation on diffusion chamber granulopoiesis was not observed in T-lymphocyte-deficient nude mice. These data suggest that in vivo stimulation of granulopoiesis is related to the level of inflammation, and that this effect requires the functional integrity of T-lymphocytes.

Abscess↗
PubMed1991

Serum immunoreactive erythropoietin level: a new parameter for monitoring transfusion management of thalassaemia.

Serum immunoreactive erythropoietin (EPO) was measured sequentially in 8 patients with thalassaemia major. The EPO levels were distinctly increased before transfusion; they did not significantly change just after transfusion, but subsequently decreased. Pretransfusion EPO levels were similar to those observed in patients with non renal non inflammatory anaemias of the same severity. Our results show that production of EPO is appropriately increased in thalassaemia major and confirm that stimulation of endogenous erythropoiesis is not completely suppressed by the hypertransfusion regimen commonly used in this disease. As hyperstimulated ineffective erythropoiesis may lead to invalidating complications, we suggest that serum EPO measurements, which are now easily and reliably performed, should be used in monitoring the therapy of thalassaemia major.

Adolescent↗
PubMed1991

Fast PCR-based quantitative detection of B-cell malignancies.

Available methods for the detection of minimal residual disease in hematologic malignancies are limited by their poor sensitivity and/or complexity. In order to avoid these drawbacks, we used the fast PCR technique to amplify the hypervariable chain-determining region 3 (CDR 3) of the human immunoglobulin heavy-chain gene in boiled marrow nucleated cells. This enabled us to detect malignant B-cells down to a dilution of 1 in 1,300 marrow nucleated cells within 7 hours of sampling. This new quantitative method should be useful for monitoring therapy and detecting early disease relapse in B-lymphoproliferative disease since it is 10 to 60 times as sensitive as Southern blotting.

B-Lymphocytes↗
PubMed1990

Desferrioxamine improves neutrophil phagocytosis in thalassemia major.

The aims of the present study are: first, to assess the toxic role of serum from thalassemic patients in phagocytosis of PMN from healthy controls, and second, to seek to determine whether serum and cellular disturbances of polymorphonuclear neutrophils (PMN) phagocytosis, observed in thalassemic patients, can be prevented and/or corrected by use of desferrioxamine (DFX). Two kinds of in vitro incubations--without or with DFX--were performed. PMN or serum from thalassemic patients or from healthy controls was used. First, a phagocytosis defect of 3 different bacteria species was induced in PMN from healthy controls by incubation in thalassemic serum. Second, DFX could prevent, already at 1 microM, the phagocytic defect induced in normal PMN by the incubation with thalassemic serum, with disappearance of the toxic role of thalassemic serum at higher concentrations. Third, improvement of the phagocytosis defect of PMN from thalassemic patients was also observed at 1 microM of DFX for the 3 bacteria species. Normalization was obtained at higher concentrations for gram-negative bacteria. In vivo studies revealed, after a 3 hr subcutaneous infusion of DFX into 3 thalassemic patients, an improvement of the phagocytosis results and a decrease of the Prussian Blue reactivity of the PMN. It is concluded first that an iron-mediated defect in phagocytosis can be induced in normal neutrophils by incubation in serum from thalassemic patients, and second that a precautious and intensive chelation therapy seems to be advantageous for increasing PMN defense against infectious agents. Special care must nevertheless be taken in order to detect rapidly opportunistic (such as Yersinia) infections.

Adolescent↗
PubMed1990

In vivo elaboration of CSF in acute inflammation: proportionality to the intensity of the inflammatory stimulus and requirement of T lymphocytes.

The colony-stimulating factor(s) (CSF) that stimulates the in vitro growth of bone marrow granulocyte-monocyte progenitors (CFU-GM) increases in the serum of mice challenged by an aseptic abscess induced by copper rod insertion. The effect of the inflammation on the increase of serum CSF is dose-related. The creation of 3 aseptic abscesses indeed results in a higher and longer elevation of serum CSF than 1 abscess. Serum CSF also increases in parallel with the rise in bone marrow CFU-GM; this is consistent with the CSF playing a role in regulation of haematopoiesis in vivo. From previous studies, it appears that T lymphocytes play a central role in the regulation of haematopoiesis. In order to determine the role of T lymphocytes in the inflammation response, cyclosporin A (CyA), an inhibitor of T lymphocyte function, was given in vivo, 2 days before inflammation induction. CyA abrogates the increase in both serum CSF and CFU-GM. Furthermore, a lower increase in serum CSF was observed in copper-implanted nude mice. These results suggest that the CSF production induced by inflammation requires the functional integrity of T lymphocytes.

Abscess↗
PubMed1989

Staphylococcus aureus phagocytosis. A new cytofluorometric method using FITC and paraformaldehyde.

A new method for measuring the uptake of Staphylococcus aureus by human polymorphonuclear neutrophils (PMN) using flow cytometry (FCM) is described. Bacteria were labeled with fluorescein isothiocyanate (FITC) and incubated with PMN in a suspension assay. At the end of the assay, phagocytosis was arrested by the addition of cold paraformaldehyde. Thereafter, phagocytosis was quantitated by FCM, using crystal violet to distinguish adherent versus ingested bacteria. The method was validated in multiple samples by reference to our microscopic technique; correlations of phagocytic indices were in good agreement. The FCM method was also found to be reproducible and provided a mean to detect low phagocyte values. Another feature of the approach is that FCM readings can be delayed without any appreciable alterations in the results.

Flow Cytometry↗
PubMed1989

Inherited factor XIII deficiency.

A new observation of inherited factor XIII deficiency is described. The patient had presented in the past with an umbilical haemorrhage, a cerebral haemorrhage, multiple haematomas with delayed onset after minimal trauma, and episodes of spontaneous haemarthrosis. The biological diagnosis was made at the age of 7 years. The child had undetectable transamidating activity and factor XIII a chains, while the level of b chains was reduced. The values observed in the parents were intermediate between those of the patient and those of normal plasma. Heated factor VIII concentrates were found to contain only low amounts of factor XIII, and were thus unsuitable for the prophylactic therapy of this rare disease. The patient was successfully treated with monthly injections of a factor XIII concentrate.

Blood Coagulation Factors↗
PubMed1989

[Comparative study of 2 common tests for lupus anticoagulant determination: critical analysis of the results observed in 21 patients].

The Schleider and/or the Exner test have been found positive in twenty-one patients; five of these patients suffered of systemic lupus erythematosus (SLE). The Quick time and the activated partial thromboplastin time are normal in 52% of the cases. 40% have a minor haemorrhagic diathesis, without other significant clotting defect and 30% have thrombo-embolic complications. The Schleider index is more often strongly positive (greater than 2) in these two groups. 58% have an anemia, 25% a mild thrombocytopenia not deep enough to explain an haemorrhagic tendency (from 90.000 to 140.000/mm3). Several auto-immune tests are frequently positive even without SLE. The Schleider test is positive in 86% of the cases and appears a little more useful for the diagnosis than the Exner test, which has a 71% positivity.

Adolescent↗
PubMed1989

[Prevention of beta-thalassemia in the French speaking part of Belgium. I. Epidemiologic, clinical, psycho-social and economic justifications].

A study was jointly conducted by three universities in order to determine whether the systematic prevention of beta-thalassaemia and related affections is justified in the French-speaking part of Belgium. In the entire geographical area considered, 19.1% of the population are foreign; 19.2% of births take place within foreign families. Around 59.7% of foreigners come from regions where beta-thalassaemia is endemic. The ethnic minorities are mostly concentrated in the cities and notably in Brussels. Around 4.1% of the minorities ethnically at risk are carriers of beta-thalassaemia. Births of new cases of thalassaemia major can be estimated at 2.9 per year, which would result, in the absence of prevention, in a population of 130 cases of thalassaemia major. In recent years, patient care has improved considerably, as demonstrated by an increasingly early diagnosis and institution of chelating therapy with an attendant gradual drop in ferritin levels. However, study of age histograms reveals that care of patients in non-endemic regions is not as satisfactory as in endemic countries where complete haemoglobinopathy control programmes have been developed. Psycho-social questioning of a sample of families confirmed that thalassaemia major is an affection which seriously impairs the quality of life. Finally, calculations projected over 20 years revealed that systematic prevention would cost from 2.3 to 2.8 times less than a purely curative approach. The authors conclude that a body of epidemiological, clinical, psycho-social, and economic arguments justify without any doubt the prevention of beta-thalassaemia and related affections in the French-speaking part of Belgium.

Adolescent↗
PubMed1989

Protein kinase C deficiency in juvenile chronic myeloid leukemia: a case report.

Protein kinase C activity was assayed in morphologically differentiated and undifferentiated myeloid cells of a 13-month-old girl with chronic myeloid leukemia. A reduced protein kinase C activity was seen in the morphologically differentiated neutrophils, while the activity in the leukemic cells was higher to that of normal neutrophils from control subjects.

Adult↗
PubMed1989

[The prevention of beta-thalassemia in French-speaking Belgium. II. Proposal of a strategy].

Medico-social surveys and pilot experiments, conducted by the authors in Wallonia and Brussels at the request of the Ministry for the French-Speaking Community, have allowed the definition of a community-scale prevention programme. High-quality information, repeated at regular intervals and adapted to the different environments, is vital for effective voluntary screening. The contents of this information and distribution methods have been specified. Screening will take place on an occasional basis among people at risk who request it, or who accept it as an addition to other planned blood tests (curative or preventive consultations); microcytosis must be considered as a definite indication for further work up. Systematic screening is recommended in the framework of upper secondary education, through cooperation between volunteer teachers and the staff of school medical institutions; teaching methods and means have been reviewed.

Belgium↗