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H Rochant

Publications and source records attributed to H Rochant.

At least 73 records · Page 4Linked to original sources
PubMed1983

Adult T-cell lymphoma leukemia in Western countries.

A new T-cell disorder has recently emerged: the so-called adult T-cell lymphoma leukemia (ATLL) initially described in Japan. Subsequently, ATLL cases were recognized in patients from the Caribbean. We summarize the clinical and hematological features of 19 published cases from Western countries, in addition to a new case we encountered. The leukemic cells display characteristic morphological features and a T3+T4+T8-T6- surface antigenic phenotype. Overall survival is of short duration, but remission could be obtained in our case despite a subsequent relapse in skin and CNS. Geographic clusters of ATLL cases have led to the discovery of the possible role of a new retrovirus, HTLV, in the genesis of this rare malignancy.

Adult↗
PubMed1983

Erythroid properties of K562 cells. Effect of hemin, butyrate and TPA induction.

Two sublines of the human leukemia cell line K562 including the original cell line and three clones have been investigated for their erythroid features. All of them produce embryonic and fetal hemoglobins, glycophorin A, spectrin and true acetylcholinesterase, but to a varying extent among the cell lines. The Hb and glycophorin contents were correlated in the different K562 cell lines, whereas acetylcholinesterase was independently expressed from these two other erythroid markers. Hb accumulation is enhanced by exposure of the cells to 100 microM hemin without a significant modification of the expression of the other erythroid markers. Butyrate greatly increased the activity of acetylcholinesterase, slightly enhanced the production of hemoglobin, but did not modify the expression of glycophorin and spectrin. 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced an almost complete disappearance of glycophorin, reduced the synthesis of Hb by K562 cells and also abolished the action of hemin on Hb accumulation. Therefore, all the different K562 cell lines exhibit clear erythroid features including acetylcholinesterase. Butyrate or hemin did not induce terminal differentiation of K562 cells, whereas TPA significantly diminished the erythroid phenotype.

Acetylcholinesterase↗
PubMed1983

Cytomegalovirus encephalitis occurring after bone marrow transplantation.

4 months after a bone marrow transplantation performed for acute lymphocytic leukaemia, a 28-year-old man had encephalitis. A brain CT scan revealed bilateral and symmetrical temporal hypodense areas. Serological studies revealed a recent CMV conversion in serum and a higher conversion in cerebral spinal fluid. All other viral antibodies remained at low levels, especially for herpes simplex virus. Because of a high incidence of CMV infection after bone marrow transplantation, the responsibility of CMV as the cause of the encephalitis is discussed.

Adult↗
PubMed1983

The number of the Trf receptors on human hematopoietic cell lines is influenced by membrane phospholipids.

The effect of phospholipases and of inhibitors of phospholipases on the binding of 125I-Trf to human hematopoietic cell lines was investigated. The results showed that incubation of the cells with phospholipases or inhibitors of phospholipases elicited a significant reduction of the Trf binding. This phenomenon was related to a reduction of Trf binding sites without affecting the affinity of the receptors for Trf. These results suggest that the phospholipids of the cell membrane may modulate the binding of transferrin to its receptor.

Acetophenones↗
PubMed1983

[Modulation of the expression of transferrin receptors by iron, hemin and protoporphyrin IX].

The expression of transferrin receptors in human leukemic cell lines was investigated. Our results have clearly shown that heme, iron and protoporphyrin-IX may modulate the expression of Trf receptors: iron and heme induce a decrease in the number of Trf receptors; in contrast protoporphyrin-IX elicited a significant increase in the number of Trf receptors. On the basis of these data we suggest that the intracellular concentration of iron, heme and protoporphyrin-IX may represent the main factor involved in the regulation of the expression of Trf receptors.

Animals↗
PubMed1983

Myeloid and megakaryocytic properties of K-562 cell lines.

The expression of myeloid and megakaryocytic markers of differentiation has been studied in one K-562 cell subline, in its clones, and in the original cell line. Cytotoxicity, electron microscopy, immunofluorescence studies with a panel of polyclonal and monoclonal antibodies, and radioimmunoassays were performed on K-562 cells before and after induction with hemin, sodium butyrate, and 12-O-tetradecanoylphorbol-13-acetate. Myeloid membrane markers were present in all K-562 cell lines. Only the early granulopoietic cell surface markers were expressed in 75 to 95% of the cells, while none of the late membrane markers was detected. In contrast, neither the early (myeloperoxidase) nor late (lactoferrin) cytoplasmic markers were present. Thus, K-562 cells showed a membrane phenotype similar to that of a normal or leukemic promyelocyte but lacking myeloperoxidase. Membrane megakaryocytic markers, such as platelet glycoprotein IIIa and platelet peroxidase, were also detected in K-562 cells. However, some other early megakaryocytic markers, such as platelet glycoprotein lb, Factor VIII-R-Ag, and platelet Factor 4, could not be detected by fluorescent labeling. Cloning of the cell line did not result in the selection of a unipotential cell line. These results could be explained by the expression of multilineage markers in a single cell. In all of the cell lines and clones, hemin slightly increased the expression of the myeloid membrane markers without any modification of the megakaryocytic markers. Sodium butyrate and 12-O-tetradecanoylphorbol-13-acetate diminished most of the myeloid markers and very significantly increased the expression of the megakaryocytic markers.

Antibodies, Monoclonal↗
PubMed1983

[Hemochromatotic cirrhosis complicating pyridoxine-sensitive hereditary sideroblastic anemia. Case report].

A further case of sporadic congenital sideroblastic anaemia is reported. Despite no contributing factors such as blood transfusion, oral ingestion of iron or alcoholic beverages, were present excessive iron stores occurred with consecutive tissue damage resulting in cirrhosis of the liver, portal hypertension and diabetes mellitus. HLA phenotype was A3 B7 as in primary hemochromatosis. Correction of anemia was obtained by vitamin B6 administration. Improvement of iron overload was achieved through the use of daily subcutaneous infusions of the iron chelating drug desferrioxamine with a portable infusion pump.

Adult↗
PubMed1983

[Bacterial septicemia in neutropenia patients].

Two hundred bacterial septicemia occurring in neutropenic patients (PMN less than 1,000 microliter) were analyzed. Most of these patients had hematologic malignancies. The underlying disease, the degree of neutropenia the association of septic focus with the bacteremia, the responsive microorganisms and their evolution during hospitalization were studied as prognosis factors. The overall mortality was 32.5 p. 100. The mortality was higher in patients whose granulocyte count was lower than 500 microliter. The occurrence of major septic focus (pulmonary, perineal infection, diarrhea with abdominal distension, ORL, or cutaneous extensive focus) during bacteremia was a highly significant factor of bad prognosis. The mortality of bacteremias with and without major septic focus was respectively 62 p. 100 and 15 p. 100. A study of the distribution of the bacterias was performed in terms of mortality and duration of hospitalization. "Escherichia coli" and gram positive cocci were predominant during the two first days and mortality was then low. After that time, others Gram-negative bacterias appeared, especially "Pseudomonas aeruginosa" and the mortality was increasing until the twentieth day. Therefore, the authors raise the opportunity of antibiotic therapy according to the duration between the beginning of the hospitalization and the occurrence of sepsis in neutropenic patients. The role of the extensive use of a curative antibiotic association using colistine and nalidixic acid between 1974 and 1976 is discussed in the emergence of more gram positive cocci bacteremias between 1976 and 1978 than between 1974 and 1976 in the same intensive care unit.

Agranulocytosis↗
PubMed1983

[Acute leukemia and breast cancer : apropos of 12 cases observed in the Department of Oncology at the Henri Mondor Hospital].

The authors report 12 cases of acute leukemia observed after breast cancer. 4 patients received only adjuvant radiotherapy, whereas the other eight received both chemotherapy and radiotherapy. Acute leukemia appeared with a mean time of 5.5 years after the detection of breast cancer and was preceded in 7 cases by isolated pancytopenia during 4 months. Acute leukemias were always non lymphoblastic and myelofibrosis was very frequent. A complete remission was obtained at three patients out of the seven treated. The mean survival time was 5.6 months. The existence of acute leukemia after chemo-and/or radiotherapy poses several problems. The detection of patients with a high risk of leukemia by different methods such as cytogenetic, studies of dysmyelopoietic symptoms, is actually often too late occurring during preleukemia states of bad prognosis. We also need to know the exact incidence of secondary leukemia after treatment of breast carcinoma and the real benefit of such treatment.

Acute Disease↗
PubMed1982

Clonal expression of the Tn antigen in erythroid and granulocyte colonies and its application to determination of the clonality of the human megakaryocyte colony assay.

To evaluate whether exposure of Tn determinants at the surface of human erythrocytes, platelets, and granulocytes could arise from a somatic mutation in a hemopoietic stem cell, burst-forming unit erythroid (BFU-E) colonies, colony-forming unit granulocyte-macrophage (CFU-GM), and colony-forming unit-eosinophil (CFU-Eo) were grown from a blood group O patient with a typical Tn syndrome displaying two distinct populations (Tn(+) and Tn(-)) of platelets, granulocytes, and erythrocytes. A large number of colonies was observed. Individual colonies were studied with a fluorescent conjugate of Helix pomatia agglutinin (HPA). A sizeable fraction of each of the erythroid and granulocytic colonies appeared to consist exclusively of either HPA-positive or HPA-negative cells, thereby demonstrating the clonal origin of those exhibiting the Tn marker. Similar results were obtained from a second patient. These findings establish that the HPA labeling of Tn cells is an accurate marker permitting assessment of the clonality of the human megakaryocyte (MK) colony assay. For the study of MK cultures a double-staining procedure using the HPA lectin and a monoclonal antiplatelet antibody (J-15) was applied in situ to identify all MK constituting a colony. Our results, obtained in studies of 133 MK colonies, provide definitive evidence that the human MK colony assay is clonal because all MK colonies were exclusively composed of Tn(+) and Tn(-) MK. Furthermore, the distribution of MK within a single colony was shown to be seminormal with a mean at 6 MK, isolated MK typically being absent in culture. Comparison of the proportion of mature Tn(+) cells in blood with their respective Tn(+) progenitors has also shown that no proliferative advantage occurs after the commitment; because Tn polyagglutinability is an acquired disorder, then the expansion of the Tn(+) clone must occur either during the proliferative stage of the pluripotent stem cell or during the commitment itself. This study therefore affords evidence that a blood group antigen plays a role in the differentiation of a pluripotent stem cell.

Adult↗
PubMed1982

Reticulocytosis, hypochromia, and microcytosis: an unusual presentation of the preleukemic syndrome.

Two patients exhibiting a highly unusual preleukemic syndrome with marked reticulocytosis, hypochromia, and microcytosis are reported. This red cell phenotype has been investigated by means of HbF, HbA2, and i-antigen activity dosages, immunofluorescence labeling of F cells, reticulocyte survival, globin chain synthesis, and electron microscopy study. The marked reticulocytosis is explained by a delayed disappearance of the reticulum. Serum iron is normal, and a thalassemic syndrome is excluded because of a balanced alpha/non-alpha globin chain synthesis. Electron microscopy studies are consistent with a defect in iron uptake by erythroid cells. All the hematologic data and investigations are similar to those observed for the Belgrade laboratory rat. It is hypothesized that the low expression of HbF and i-Ag associated with microcytosis are related to a prolongation of erythroid maturation as reflected by abnormal reticulocyte survival.

ABO Blood-Group System↗
PubMed1982

Regulation of i- and I-antigen expression in the K562 cell line.

Expression of i- and I-antigen in K562 cultured under different conditions of culture was investigated. Under standard conditions of culture, i-antigen expression was very high (100% of i-labeled cells) in contrast to I-antigen expression of which was very low (2 to 5% of I-labeled cells). The addition of hemin to K562 cells did not modify the mean antigenic density or the proportion of i- and I-labeled cells. In contrast, sodium butyrate elicited an important increase in the proportion of cells exhibiting I-antigen associated to a decrease of i-antigenic density. The effect of butyrate was reversible and dependent upon de novo protein and messenger RNA synthesis since it was abolished in the presence of cycloheximide or actinomycin D. The stimulation of i-antigen conversion to I-antigen elicited by butyrate cannot be directly related to an induction of differentiation since evidence in this sense is lacking; in fact, butyrate did not increase the hemoglobin content of K562 cells. The passage from exponential to stationary phase of growth (cell density inhibition) was associated with an increase in I-antigen expression and a slight decrease in i-antigen density on the surface of K562 cells.

Antigens↗