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Biomedical subjects

R Or

Publications and source records attributed to R Or.

At least 217 records · Page 12Linked to original sources

Monoclonal rat anti-human lymphocyte antibody Campath-1 binds to T and B lymphocytes but effectively lyses only T cells.

Binding and human complement-mediated T and B lymphocyte lysis were investigated in bone marrow samples obtained from 15 normal donors and 12 patients with a variety of malignant disorders undergoing marrow cryopreservation prior to autologous bone marrow transplantation. All marrow samples were obtained during remission except for one patient with neuroblastoma. The mononuclear cell fractions were collected and the distribution of B cell restricted markers (surface Ig and GP-70) and T cell surface markers (Leu-1 and rosettes with sheep red blood cells) were studied before and after marrow purging with Campath-1, a monoclonal rat anti-human lymphocyte antibody, and autologous serum as complement. Effective lysis of T lymphocytes (greater than 99.5%) was documented in all cases. However, although effective binding of Campath-1 to B lymphocytes was uniform, no effective lysis occurred. The data suggest that effective lysis of mature T lymphocytes can be accomplished while leaving normal B lymphocytes intact.

Antibodies, Monoclonal↗

Hairy cell leukaemia: effects of phorbol ester on cell morphology and adherence and comparison with other B-cell neoplasias.

This report documents phorbol ester-induced changes in cell morphology in 9 patients with hairy cell leukaemia (HCL) and contrasts them with those obtained in cells from 20 patients with B-type chronic lymphocytic leukaemia (CLL) and non-Hodgkin's lymphoma in leukaemic phase (NHL). The phorbol ester caused hairy cells to adhere strongly and produce thin elongated cytoplasmic extensions. Other cells showed marked surface ruffling, and contained increased numbers of phagolysosomes, although cells still retained ribosomal lamellar complexes. This in vitro growth pattern differed from that observed in B-CLL and NHL cells, which readily detached in clumps with minimal adherence. CLL and NHL-cells did not show macrophage features but developed plasmacytoid and hairy cell-like features. It is suggested that these different growth patterns may aid in distinguishing HCL from other B-cell neoplasias.

B-Lymphocytes↗

Adhesion, spreading and fragmentation of human megakaryocytes exposed to subendothelial extracellular matrix: a scanning electron microscopy study.

Platelet agonists and subendothelial extracellular matrix (ECM) induce morphological and biochemical changes in animal megakaryocytes, reminiscent of the response of platelets to the same substances. We have examined the behavior of human megakaryocytes exposed for up to 36 hours to the ECM produced by cultured bovine corneal endothelial cells. By phase contrast and scanning electron microscopy these megakaryocytes demonstrated non-reversible adherence and flattening with formation of long filopodia, thus confirming that human megakaryocytes acquire platelet functional capacities. In addition, megakaryocyte fragmentation into prospective platelets was apparently induced by the ECM. Up to 50% of the adherent megakaryocytes underwent spontaneous fragmentation into small particles which individually reacted like platelets on the ECM. The interaction of the megakaryocytes with the ECM was specific since no adherence, flattening or fragmentation occurred upon incubation of the megakaryocytes on regular tissue culture plastic or glutaraldehyde fixed ECM. Thus we have demonstrated platelet like behaviour of human megakaryocytes in response to this physiological basement membrane and a possible role of the subendothelium in platelet production which may occur in vivo as megakaryocytes cross the sinusoid walls and enter the blood stream.

Animals↗

Hairy cell leukemia associated with carcinoma: report of two patients and review of the literature.

The association of carcinoma and hairy cell leukemia (HCL) in two patients is recorded. One of the cases was a 58-year-old male who developed carcinoma of the kidney, while the second patient was a 48-year-old woman with carcinoma in the breast. This rare association is probably coincidental, as it is not described in most of the larger reported series of patients with HCL. It is of interest to note that the first patient had received radiation therapy thirty years before the diagnosis of HCL and carcinoma was made.

Adenocarcinoma↗

Bronchopulmonary candidiasis exacerbating asthma. Case report and review of the literature.

We describe a perplexing asthmatic patient who had chronic lymphatic leukemia that developed recurrent severe and prolonged attacks of asthma which required almost continuous hospitalization. Clinical findings of fever, leukocytosis, right lower lobe infiltrate and mouth candidiasis were suggestive of bronchopulmonary candidiasis. No further diagnostic tests were done and the patient responded favorably to amphotericin B therapy. A review of bronchopulmonary candidiasis in adults is discussed briefly. Lung biopsy should be reserved only for the most obscure and problematic cases.

Amphotericin B↗

Results of therapy in adult acute nonlymphoblastic leukemia: experience in Jerusalem, Israel, during 1975-1982.

78 previously untreated patients (aged 16-82 years) with acute nonlymphoblastic leukemia received intensive chemotherapy for induction of remission. In 64 patients, the combination used consisted of daunomycin and cytosine arabinoside with or without 6-thioguanine. The overall remission rate was 59 and 87% for those who received what was considered as adequate therapy. Patients who achieved remission received maintenance and, in part, late intensification. The median duration of remission was 9 months. The median survival of the patients who attained remission was 24 months, compared to 15 months for the entire patient group and 3 months for patients who failed to achieve remission. Age had no effect on the rate and duration of the remission obtained but the median survival was significantly longer in patients below the age of 50 years.

Adolescent↗

Captopril-associated transient aplastic anemia.

A patient with chronic renal failure and secondary hypertension was treated with captopril. Aplastic anemia developed in association with the captopril treatment which resolved promptly after discontinuation of this drug.

Anemia, Aplastic↗

Elimination of graft-versus-host disease by in-vitro depletion of alloreactive lymphocytes with a monoclonal rat anti-human lymphocyte antibody (CAMPATH-1).

A new monoclonal rat anti-human lymphocyte antibody (CAMPATH-1) which lyses cells with autologous human complement was used for depletion of T lymphocytes from human bone-marrow allografts in vitro before transplantation in 11 high-risk patients. HLA-matched siblings were used as marrow donors. T-cell depletion was substantial when measured by E-rosette formation (0-0.18% residual T cells) and immunofluorescence with a monoclonal anti-T-cell antibody (0-0.5%). No anti-graft-versus-host disease prophylaxis was given after transplantation. Rapid engraftment was reported in all patients, and the post-transplantation course was uneventful. No signs of graft-versus-host disease developed in any of the patients, who were observed for a maximum period of 12 months. The method might be suitable for larger-scale studies in high-risk patients. The late graft failure seen in 2 patients may reflect residual host resistance uncompromised by GvHD.

Adolescent↗

Concanavalin A receptors on the surface membrane of lymphocytes from patients with acute leukemia.

Peripheral blood mononuclear cells (PBM) isolated from 23 patients with acute lymphoblastic leukemia (ALL) and 24 with acute non-lymphoblastic leukemia (ANLL) were studied for binding and mobility of Concanavalin A (Con A) receptors, using fluorescent Con A (F-Con-A). The cap forming ability of PBM from all patients was 18.7 (+/- 9.3%) and 18.9 (+/- 9.9%) for ANLL patients at the time of diagnosis or during relapse. During clinical complete remission the cap forming ability of the PBM did not change significantly. No correlation was observed between the percentage of blasts present in the peripheral blood at the time of examination and the extent of cap formation, for both types of leukemia. The pattern of F-Con-A binding to PBM in ANLL patients was different compared to that seen in ALL. In ANLL, the fluorescent stain was concentrated in a round body on the cell ("button form") after binding to the membrane, while the rest of the cell showed almost no fluorescence. The present results indicate that PBM cells from patients with acute leukemia are characterized by a high degree of Con-A receptor mobility.

Cell Membrane↗

Hairy cell leukemia: report of an unusual case with hepatomegaly due to a large vascular tumor of the liver, mediastinal mass and pleural effusion containing hairy cells.

An unusual patient with hairy cell leukemia (HCL) who developed marked hepatomegaly due to a large vascular tumor in the liver is reported. The relation of this vascular tumor to the microscopic splenic pseudosinuses and hepatic angiomatous lesions encountered in HCL is discussed. To the best of our knowledge this represents the first case report of the association of HCL with large macroscopic hemangioma of the liver causing hepatomegaly. The patient also developed a large paratracheal mediastinal mass with a recurrent pleural effusion which was shown to contain many typical hairy cells. This rare finding is discussed in relation to the isolated cases of lymphocytic lymphoma who present with clinical and morphological features mimicking HCL. This patient had HCL according to all established criteria with characteristic morphological, cytochemical and ultrastructural features and the pleural effusion and mediastinal mass were most probably part of the HCL neoplasia, despite the fact that biopsy was not performed.

Female↗

Chlorpropamide-induced hemolytic anemia.

Acute intravascular hemolysis developed when a diabetic patient, previously treated with glyburide, was started on another oral sulfonylurea drug, chlorpropamide. Immunoglobulins were not found in the patient's serum and the red cells were coated with C3 only, suggesting an "innocent bystander" reaction. This case demonstrates that there is no cross reactivity between glyburide and chlorpropamide in producing hemolytic anemia.

Anemia, Hemolytic↗