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H Rochant

Publications and source records attributed to H Rochant.

At least 19 recordsLinked to original sources
PubMed1995

Impact of magnetic resonance imaging on the diagnosis of abdominal complications of paroxysmal nocturnal hemoglobinuria.

Magnetic resonance (MR) imaging is a method of choice for assessing vascular patency and parenchymal iron overload. During the course of paroxysmal nocturnal hemoglobinuria (PNH), it is clinically relevant to differentiate abdominal vein thrombosis from hemolytic attacks. Furthermore, the study of the parenchymal MR signal intensity adds informations about the iron storage in kidneys, liver, and spleen. Twelve PNH patients had 14 MR examinations of the abdomen with spin-echo T1- and T2-weighted images and flow-sensitive gradient echo images. Vessels patency and parenchymal signal abnormalities--either focal or diffuse--were assessed. MR imaging showed acute complications including hepatic vein obstruction in five patients, portal vein thrombosis in two patients, splenic infarct in one patient. In one patient treated with androgens, hepatocellular adenomas were shown. Parenchymal iron overload was present in the renal cortex of eleven patients with previous hemolytic attacks. On the first MR study of the remaining patient with an acute abdominal pain showing PNH, no iron overload was present in the renal cortex. Follow-up MR imaging showed the onset of renal cortex iron overload related to multiple hemolytic attacks. Despite the fact that all our patients were transfused, normal signal intensity of both liver and spleen was observed in three of them. MR imaging is particularly helpful for the diagnosis of abdominal complications of PNH.

Abdominal Pain↗
PubMed1995

Evolution of bacterial susceptibility to antibiotics during a six-year period in a haematology unit.

A knowledge of the bacterial ecology of a haematology unit should help in the management of the febrile patient with or without neutropenia. We studied the prevalence and the susceptibility profiles of bacteria isolated during a six-year period among patients hospitalized in a 44-bed haematology unit. Antibiotic use over this period was also studied. The most prevalent bacteria were coagulase-negative staphylococci (CNS) (35.1%), Escherichia coli (11.4%), Staphylococcus aureus (9.9%), Enterococcus spp. (8.2%), and Pseudomonas aeruginosa (7.5%). The susceptibility of CNS to oxacillin decreased from 67-44% over six years, while that of enterobacteriaceae to amoxycillin and piperacillin was reduced by about 50%. P. aeruginosa susceptibility to ceftazidime remained remarkably stable at around 90%, despite extensive empirical use. Imipenem and ciprofloxacin were used restrictively and ceftazidime-resistant P. aeruginosa remained susceptible to these two agents in most cases. Our antibiotic policy was found to be compatible with the frequency of the bacterial strains isolated in our department and with their susceptibility profiles.

Anti-Bacterial Agents↗
PubMed1995

[Managing of an innovation in health care: the case of polyvalent intravenous immunoglobulins at the Assistance-Publique-Hôpitaux de Paris].

Managing new innovations in medicine is a particularly timely subject. There is an abundant history concerning over expectations resulting from the development of new treatments or diagnostic procedures, some shown to be less effective than promised, others even found to be dangerous. A new aspect to the question is the importance of economic pressures which require rational investment decisions when diffusing innovating technologies. In 1991, the Commission for the evaluation and diffusion of innovating technologies (CEDIT) at the University Hospitals of Paris (Assistance Publique-Hôpitaux de Paris) developed a programme aimed at better managing the distribution and use of polyvalent intravenous immunoglobulins (IgIV), a new promising therapeutic tool with both a high cost and a certain number of risks. The programme was designed to assist prescribers in elaborating better therapeutic strategies and to help hospital managers rationalize expenditures for IgIV. The results of this experience are presented here together with certain conclusions concerning the way management decisions can be applied to the diffusion of an innovation in health care.

Diffusion of Innovation↗
PubMed1994

Exhaustive analysis of the P53 gene coding sequence by denaturing gradient gel electrophoresis: application to the detection of point mutations in acute leukemias.

We report the set-up of a denaturant gradient gel electrophoresis (DGGE) assay to screen for mutations in the whole coding sequence of the p53 gene. These DGGE experimental conditions were applied to the analysis of the p53 gene in acute leukemias. Forty adults with acute myelogenous leukemia (AML) and 21 with acute lymphoid leukemia (ALL) were investigated. Eleven of the AML patients were investigated at the time of the initial diagnosis and at relapse. In contrast with most reports based on amplified fragments analyzed by single-strand conformation electrophoresis and focusing on exons 5 to 8, we analyzed the whole coding sequence of the gene. Two of the 40 AML patients displayed a point mutation in exon 7; it was either an A to G substitution that converted Tyr-234 to Cys, or a G to A change that converted Arg-248 to Gln. The screening procedure led to the discovery of several intronic and exonic polymorphisms. These results confirm the low incidence of p53 mutations in acute leukemias and suggest a limited role of the p53 protein in leukemogenesis. The computerized modeling and electrophoresis parameters presented here provide a powerful tool for the exhaustive characterization of p53 mutants in all kinds of malignancies.

Acute Disease↗
PubMed1993

[Chronic anemia: diagnostic tools and approach].

Anaemia is frequently encountered in daily practice. With full knowledge of its pathophysiology a rational classification is possible allowing a suitable approach for diagnostic investigations. In a first stage, the data provided by blood counts, erythrocyte constants and reticulocyte counts guide the diagnostic rationale. In cases with microcytic and hypochromic anaemia, measurement of ferritin level separates iron deficiency anaemia from the so-called "inflammatory" anaemias. A high number of reticulocytes points to haemolytic anaemia. Among the many causes of haemolysis, one must first look for autoimmune haemolysis. Elsewhere, the clinical context and morphological red cell abnormalities point to a hereditary disease affecting the erythrocyte membrane, enzymes or globin content. Although rare, microangiopathic anemia with schizocytosis and paroxysmal nocturnal haemoglobinuria must not be misdiagnosed. Bone marrow examination remains the clue in non-regenerative normochromic, normo- or macrocytic anaemias. In difficult cases, other investigations, such as cytogenetics, isotopic examination and progenitor culture, may help in characterizing the anaemia. Serum erythroproietin essays and plasma transferrin receptor counts will soon figure among the methods used to explore anaemias.

Aged↗
PubMed1992

Usefulness of consensus conferences: the case of albumin.

The usefulness of consensus conferences has been questioned. We have assessed the impact of a 1989 consensus conference about the treatment of hypovolaemia on prescribing practice at our hospital. Data available from the blood bank enabled us to follow albumin use and costs by department between 1987 and 1991. Medical journals, direct mail, and meetings were used to disseminate the recommendations of the consensus conference, which were that the only indications for albumin are massive haemorrhage, plasmapheresis, massive hypoalbuminaemia, and volume expansion in pregnancy; for hypovolaemia caused by septic shock or vasoplegia, fluid gelatins and crystalloids should be used. In the year after the conference, and in subsequent years, albumin use and costs were 40% lower than before the conference, even though total medical expenditure continued to rise and numbers of patients admitted did not change. We believe that consensus conferences can be a useful means of improving medical practice. The features that ensured success in this programme were the small number of prescribers, the homogeneous setting, and the frequent restatement of the recommendations.

Consensus Statements as Topic↗
PubMed1990

Induction of cytolytic function in resting peripheral blood CD8+/Leu-7+ T cells through IL2/p 75 IL2-receptor interaction: a study in the allogeneic human bone marrow transplantation model.

CD8+/Leu-7+ T cells which circulate in increased proportions in the blood of long-term surviving BMT patients are for the most part high-density resting lymphocytes lacking IL2R-alpha (p55) expression. We show that they can be induced by IL2 to manifest cytolytic function after 24-48 hr stimulation by using rather high concentrations of IL2 (at least 50 U/ml). This function was much more readily induced in high-density CD8+/Leu-7+ T cells than in high-density CD8+/Leu-7+ T cells and occurred in the presence of minimal cell proliferation. Other cytokines involved in primary CTL differentiation (IFN-gamma, IL4 and IL6) were without effect suggesting that CD8+/Leu-7+ T cells are, in the BMT model, in vivo preactivated CTL ready to differentiate into cytolytic effectors under the sole IL2 stimulus. TU27 Mab directed at IL2R-beta (p75) subunit almost completely prevented IL2-induced cytolytic function of CD8+ T cells while 33B3.1 Mab directed at IL2R-alpha (p55) subunit was ineffective, suggesting that the signal for this function has its origin in IL2R-beta chains constitutively expressed by these cells.

Antibodies, Monoclonal↗
PubMed1990

Abnormally expanded CD8+/Leu-7+ lymphocytes persisting in long-term bone marrow-transplanted patients are resting pre-cytotoxic T-lymphocytes.

We analyzed the functional status of the small CD8+/Leu-7+ T-lymphocytes that circulate in increased proportions in the blood of many allogeneic bone marrow transplant (BMT) patients. Purified CD8+/Leu-7+ T cells were tested for their effect on T-cell proliferative responses. In contrast to CD8+/Leu-7-T-lymphocytes, such cells behaved as suppressor cells for lectin-induced mitogenic responses of the donor's peripheral blood lymphocytes. However, they did not interfere with the in vitro responsiveness to specific stimuli such as protein purified derivative (PPD) or alloantigens. We demonstrate that CD8+/Leu-7+ T cells are resting pre-cytotoxic T-lymphocytes (CTL) that can be induced by mitogenic lectins to express their cytolytic program in a non-specific, non-major histocompatibility complex-restricted manner against phytohemagglutinin-treated lymphoblasts or K562 target cells. The lectin-triggered cytotoxicity was achieved within a few days, together with limited cell division. Our results suggest that circulating CD8+/Leu-7+ T cells from BMT recipients are in vivo primed CTL awaiting cellular activation.

Antigens, CD↗
PubMed1990

Congenital sideroblastic anemia without clinical iron overload. A case report.

An 18 year old boy presented with microcytic hypochromic anemia. Erythrocytic abnormalities and family studies suggested congenital sideroblastic anemia (CSA), but atypical features included absence of clinical iron overload, scanty iron deposits in mitochondria of late erythroblasts and reticulocytes, and a high platelet count. An unusual adhesion between bone marrow macrophages and reticulocytes was observed by electron microscopy. Haematological response was seen following pyridoxine administration, thus fending support to the diagnosis of CSA.

Adolescent↗
PubMed1990

Frequent detection of minimal residual disease by use of the polymerase chain reaction in long-term survivors after bone marrow transplantation for chronic myeloid leukemia.

The polymerase chain reaction (PCR) allows the detection of minimal amounts of nucleic sequences and has been successfully used to test for the chronic myeloid leukemia-specific bcr/abl transcripts. We studied blood samples from 17 patients who had undergone allogeneic bone marrow transplantation for CML, using a modified polymerase chain reaction-based assay for the detection of leukemic mRNA. This nested PCR technique was found to be highly sensitive, detecting the chimeric bcr/abl transcript in 16 of 17 patients including several long-term survivors. Cytogenetic techniques failed to detect Ph mitoses. The clinical significance of the persisting bcr/abl transcript for long periods following BMT is poorly understood and remains to be elucidated by further studies.

Bone Marrow Transplantation↗
PubMed1989

Central nervous system relapses after bone marrow transplantation for acute lymphoblastic leukemia in remission.

This study defines the risk of central nervous system (CNS) relapse in patients undergoing bone marrow transplantation (BMT) for acute lymphoblastic leukemia (ALL) in remission, with no posttransplant prophylactic CNS therapy. Ninety-two consecutive patients in complete remission received BMT for ALL (n = 82) or high-grade non-Hodgkin's lymphoma with poor prognostic factors at diagnosis (n = 10). Sixty-six patients received allogeneic BMT (Allo-BMT) and 26 patients, without an identical sibling, underwent autologous BMT (Auto-BMT). Fifteen patients had CNS involvement at diagnosis and underwent BMT in first remission. Eight patients experienced CNS relapse after BMT, corresponding to a probability of 11% at 3 years. Apart from a history of prior CNS involvement, no patient characteristic evaluated statistically influenced CNS relapse after BMT. The probability of CNS relapse was 5.5% for the 70 patients without history of CNS involvement and 27.5% for the 22 patients with prior CNS involvement. However, subgroup analysis showed that the increased risk of CNS relapse is mainly observed in Auto-BMT patients with history of prior CNS involvement, particularly in patients undergoing BMT in first remission (three of five Auto-BMT versus one of ten Allo-BMT). Taking into account the multiple factors which influence the occurrence and the treatment of CNS leukemia, the results on this retrospective study suggests that (1) for patients without CNS involvement at diagnosis and for whom BMT is performed in first remission, cranial irradiation before BMT and posttransplant prophylactic CNS therapy can be omitted because of the low probability of CNS relapse after BMT (3.4%), when total-body irradiation (TBI) is included in the conditioning regimen; and (2) the difference observed between Allo-BMT and Auto-BMT patients with previous CNS involvement and undergoing BMT in first remission could indicate that graft-versus-host leukemia acts even in the CNS in Allo-BMT patients.

Adolescent↗
PubMed1989

[Mixed lympho-epidermal cell cultures: value in bone marrow grafts].

Graft-versus-host disease (GVHD) is the major complication of allogeneic HLA-identical bone marrow transplantation. GVHD is induced by the activation of mature T cells in the graft which react against minor antigens of the recipient. Mixed epidermal cell-lymphocyte cultures (MELC), which constitute an in vitro model of epidermal cell-lymphocyte interactions, make it possible to study the presentation of antigens to the lymphoid cells by epidermal Langerhans cells. We performed MELC in 66 patients who had received an HLA-identical bone marrow transplant for malignant blood disease. The bone marrow received by 29 recipients had been depleted of mature T cells, whereas 37 recipients had received a non-depleted bone marrow. A complete, uni- and multivariate statistical analysis was carried out on recipients of non-depleted bone marrow to evaluate the risk factors for acute and chronic GVHD. This study showed that MELC between donor and recipient was the most predictive parameter for the occurrence of GVHD. Other factors were a history of previous pregnancies in female donors and a diagnosis of chronic myelogenous leukaemia. These results may be of value in the selection of donors and for a better determination of the need for bone marrow depletion.

Animals↗
PubMed1989

Adult patients presenting with pancytopenia: a reappraisal of underlying pathology and diagnostic procedures in 213 cases.

We reviewed 213 consecutive adult pancytopenic patients to determine the frequency of underlying pathology, to analyze our diagnostic procedure, and to determine the value of peripheral blood data for diagnosis. Pancytopenia was defined as the association of hemoglobin level below 12 g/dl in males and 11.5 g/dl in females, leukopenia below 4 x 10(9)/L, and thrombocytopenia below 150 x 10(9)/L. The bone marrow aspirates were normo- or hypercellular in 140 cases (66%). Bone marrow biopsies, performed in 93 cases, documented the presence of myelofibrosis in 67 cases. Aplastic anemia was diagnosed in 10% of the cases. Malignant myeloid disorders (acute myeloid leukemias, myelodysplastic syndromes, acute myeloid disorders with myelofibrosis) represented 42% of the cases and various malignant lymphoid disorders 18%. Vitamin deficiencies accounted for 7.5% and nonhematological pathology 10% of the cases. The bone marrow aspirate was sufficient for the diagnosis in 55% of the cases, and the trephine biopsy was necessary in 30%. In the remaining cases, other complementary tests were necessary to achieve final diagnosis. A discriminant analysis, focused on the hemogram data, showed that parameters obtained by analysis of blood smears were helpful for the diagnosis, especially the presence or absence of blast cells and/or of abnormal lymphoid cells.

Adolescent↗
PubMed1988

Immunophenotype of leukemic blasts with small peroxidase-positive granules detected by electron microscopy.

Forty-three cases of undifferentiated leukemias by light microscopy examination were diagnosed as acute myeloblastic leukemias by ultrastructural revelation of peroxidase and were subsequently studied by immunological markers. In 41 of these cases, blasts were labeled by at least one of the antimyeloid MoAbs (My 7, My 9, and 80H5). An antimyeloperoxidase polyclonal antibody was used in 23 cases and was clearly positive in 11 of them, while cytochemistry by light microscopy was negative. These myeloblasts were frequently mixed with a minority of blasts from other lineages especially promegakaryoblasts. It is noteworthy that in 6 cases myeloid and lymphoid markers (E rosette receptor, common acute lymphoblastic leukemia antigen (cALLA), CD 9, CD 19 antigens (anti-B4 MoAb] were detected on a fraction of blast cells, suggesting a bilineage leukemia. However, in double labeling experiments, blasts with myeloperoxidase coexpressed lymphoid and myeloid markers including cALLA and CD 19 antigen. In one case, blasts had a typical non-B, non-T acute lymphoblastic leukemia phenotype (HLA-DR, CD 9, CD 19, cALLA positive) without staining by any of the antimyeloid MoAbs. However, 70% of the blasts were labeled by the antimyeloperoxidase antibody and expressed peroxidase-positive granules at ultrastructural level. In conclusion, most of the AML undiagnosed by optical cytochemistry are identified by antimyeloid antibodies. Some of these cases are also stained by some antilymphoid MoAbs. Use of antibodies against myeloperoxidase may improve the diagnosis of difficult cases of acute myeloblastic leukemia.

Antibodies, Monoclonal↗
PubMed1988

In vitro inhibition of normal human hematopoiesis by marrow CD3+, CD8+, HLA-DR+, HNK1+ lymphocytes.

We previously demonstrated that after allogeneic bone marrow transplantation (BMT) a subset of CD8, HNK1, and DR-positive T lymphocytes are able to inhibit CFU-GM and BFU-E growth with an HLA-DR restriction. In this study we investigated whether these cells, present in normal marrow in low concentration (less than 1%), play the same role. HNK1-positive sorted marrow cells forming rosettes (E+C) were able to inhibit BFU-E and CFU-GM growth when added back to the marrow E-C at a ratio of 1:10 (HNK1+ E+C/E-C) in a range from 40% to 60%. This inhibitory effect was also detected for a cellular ratio of 1:100, which is the normal marrow value for this subset of T cell. HNK1+ DR+-sorted E+C after double-immunofluorescent labeling also showed the same inhibitory activity as the HNK1+ E+C, whereas the negative fraction including all the other E+C had no detectable inhibitory activity. CD3 and CD8 antigens were also present on the membrane of these cells, as demonstrated in two cases by double-immunofluorescent labeling performed with anti-CD3 or anti-CD8 monoclonal antibodies (MoAbs) and HNK1 MoAb, respectively, and subsequent cell sorting. Blocking experiments, performed by adding in culture anti-CD4 and anti-CD8 MoAbs to HNK1+ T cells showed that only the last MoAb was able to prevent inhibition of hematopoietic colony growth. These results confirmed that one subset of CD3+, CD8+, HNK1+, and DR+ T cells was responsible for in vitro inhibition of normal hematopoiesis. In addition, this inhibition was genetically restricted to HLA-class II antigens, since in three co-culture experiments with unrelated bone marrow cells inhibition occurred only when cells with one haplo-identical HLA-DR antigen was added back to the culture. Indeed, this effect was really HLA-DR restricted, since in blocking experiments with different anti-HLA class II MoAbs (anti-DR, anti-DP, and anti-DQ MoAbs) only an anti-HLA-DR MoAb was able to prevent the colony growth inhibition by CD3+ HNK1+, or CD8+ HNK1+ E+C. In conclusion, the CD3+, HNK1+, CD8+, DR+ cells may be the T-cell subset able to inhibit normal hematopoiesis with an HLA-DR restriction.

Antigens, Differentiation, T-Lymphocyte↗