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Biomedical subjects

I Ben-Bassat

Publications and source records attributed to I Ben-Bassat.

At least 19 recordsLinked to original sources

Bone marrow cell populations mimicking common acute lymphoblastic leukemia in infants with stage IV-S neuroblastoma.

Immunophenotyping of bone marrow mononuclear cells of 2 infants with stage IV-S neuroblastoma revealed the presence of many lymphoblasts and immature lymphocytes. Immunophenotyping showed that a high percentage of bone marrow cells were positive for the HLA-DR, CD19, CD20 and CD10 phenotype, similar to common acute lymphoblastic leukemia cells. Within 6 months of follow-up, without any treatment, complete regression of the tumors was observed. The coexistence of these two unusual populations will be discussed.

Bone Marrow

Chromosomal aberrations suggestive of mutagen-related leukemia after 21 years of "therapeutic" radon exposure.

A 68-year-old woman with acute myelomonocytic leukemia, who was treated annually for 21 consecutive years by "therapeutic" low-dose radon gas radiation because of spondyloarthritis, is described. The karyotype of the malignant clone was 45,XX, -17, -18,del(5)(q15q33), +t(17;18)(q11.2q23). In 45% of the metaphases, the modal number was between hyperdiploid to near tetraploid. Double minute chromosomes were demonstrated in 60% of the cells. These chromosomal aberrations are suggestive of mutagen-related leukemia.

Aged

[Treatment of acute myeloid leukemia in a special hematology unit].

Since 1984, 47 patients with untreated acute myeloid leukemia (AML) were hospitalized in a special hematology unit for aggressive chemotherapy. Complete remission was obtained in 68%, 15% died of complications of treatment (infections and bleeding) and 15% had refractory leukemia. The actuarial survival after 3 years for patients in remission was 43%. No patients with refractory leukemia lived more than 1 year. The actuarial remission at 3 years of 21 patients who received additional courses of aggressive chemotherapy (consolidation treatment) was 42%, as opposed to 11% in 11 patients who received maintenance treatment. The 47 patients received 108 courses of aggressive chemotherapy including 47 for induction of remission. During 86 courses (80%) the patients developed fever and in 33 blood cultures were positive; during 16 courses a fungal infection developed. The most common bacterial infection was by E. coli. During the first induction treatment 5 patients died of sepsis and 1 of cerebral hemorrhage. None died during consolidation therapy. During the year preceding the opening of the unit, 12 AML patients were treated on regular medical wards, and five (42%) achieved a complete remission, while 6 died of complications during the first course of induction chemotherapy. Our findings are in line with those of similar units, which indicates the importance of special nursing units for the treatment of acute leukemia.

Adolescent

Tranexamic acid therapy in acute myeloid leukemia: possible reduction of platelet transfusions.

We studied the clinical efficacy and safety of the antifibrinolytic drug tranexamic acid (TA) in patients undergoing chemotherapy for acute leukemia. 54 newley diagnosed AML patients were treated with 1 g of TA every 6 hours until the platelet count rose to above 20 x 10(9)/l. Platelet transfusions were given, irrespective of the count, only when oral, mucosal or significant skin bleeding manifestations were observed. During induction, the average number of days with thrombocytopenia below 20 x 10(9)/l was 14.4 +/- 7.4 and 4.6 +/- 4.1 transfusions were given in each course. During consolidation, the average number of thrombocytopenic days was 8.4 +/- 8.5 and only 1.7 +/- 1.8 transfusions were administered. In 11.5% of the induction and 32.1% of the consolidation courses, no platelet support was required. TA was tolerated very well and no side effects or thromboembolic complications were observed. Only in 6 of the 78 induction courses did a major bleeding event occur and there were none in any of the 53 consolidation courses. Thus it seems that TA therapy allowed a significant reduction in the use of platelet transfusions without submitting the patients to greater bleeding risks.

Acute Disease

Immunoglobulin heavy chain gene rearrangements in chronic lymphocytic leukaemia: correlation with clinical stage.

A search for a correlation between the clinical stage of chronic lymphocytic leukaemia (CLL) and the pattern of immunoglobulin heavy chain gene rearrangements was undertaken. DNA samples from the leukaemic cells of 38 CLL patients were analysed by Southern blot hybridization. Using probes for the immunoglobulin heavy chain J (JH) and C mu regions a marked heterogeneity of the hybridization patterns was observed in both regions. The number of JH hybridization bands varied from one to four and more than two were found in 58% of the patients. In 42% of the patients no germline JH genes were found. One to three additional C mu bands were observed in 34%, but the germline was preserved in all samples. There was no correlation between the clinical stage and the number of hybridizing JH bands; however, a significant correlation was found between the loss of JH germline band or a C mu multiband pattern and advanced stage of the disease. The genetic events in the immunoglobulin genes observed in advanced CLL patients are assumed to result from clonal evolution and tumour progression.

Adult

Aplastic crisis due to human B19 parvovirus infection in red cell pyrimidine-5'-nucleotidase deficiency.

Two siblings with chronic hemolytic anemia due to red cell pyrimidine-5'-nucleotidase (P-5'-N) deficiency, presented within a few days of each other with a febrile illness and pancytopenia. The cause of the aplastic crisis was an acute infection with human B19 parvovirus (B19 HPV) as proven by immunoelectron microscopy and DNA hybridization. This is the first report on the association of B19-HPV-related aplastic crisis with P-5'-N deficiency.

5'-Nucleotidase

A search for bcl1, bcl2, and c-myc oncogene rearrangements in chronic lymphocytic leukemia.

Three cellular or putative oncogenes: c-myc, bcl1, and bcl2 were previously found to be rearranged in some B cell malignancies due to chromosomal translocations. Data concerning the role of such genetic rearrangements in B-CLL are very scanty and limited to few cases in which bcl1 rearrangements were found. We studied DNA samples from 38 cases of B-CLL by Southern blot technique in order to find out the existence and frequency of such events. No bcl1 or bcl2 rearrangements were found in any of the studied cases; thus, involvement of these genes in CLL must be rare. In one patient who had an aggressive and resistant disease, c-myc rearrangement was found.

Adult

Effect of alpha interferon on growth of leukemic and normal hematopoietic progenitors. Synergism with H2 histamine receptor antagonists.

We studied whether the histamine H2 receptor antagonist, cimetidine, potentiates antiproliferative effects of recombinant alpha interferon (IFN alpha) on in vitro clonal growth of certain normal and malignant hematopoietic cells. Cimetidine alone, at therapeutic serum concentrations, was not inhibitory to the cells studied. IFN alpha alone inhibited the growth of HL-60 leukemic cells only at concentrations greater than 1000 U/ml, whereas with cimetidine, inhibition was seen at greater than 1 U/ml of IFN alpha. The enhancing effect of cimetidine on IFN alpha inhibition of clonal growth was neutralized by histamine and was not seen with histamine H1 receptor antagonist. In HL-60 cells, cimetidine also increased the enzymatic activity of (2'-5')-oligoadenylate synthetase, induced by IFN alpha. The combination of cimetidine and IFN alpha had a synergistic inhibitory effect on the growth of leukemic granulocyte-macrophage colony-forming units (CFU-GM) from chronic myeloid leukemia patients, normal CFU-GM, and normal erythroid burst-forming unit (BFU-E) progenitors. These data suggest that cimetidine may play a role in overcoming resistance to IFN alpha therapy in leukemia, but may also increase IFN alpha hematopoietic toxicity.

2',5'-Oligoadenylate Synthetase

Evaluation of an intervention aimed at reducing inappropriate use of preoperative blood coagulation tests.

A multiphase intervention trial based on education, implementation of criteria, and restriction, aimed at modifying the established clinical policy of mandatory preoperative screening for coagulation abnormalities, was carried out on five surgical wards of a general hospital. The education period did not influence the ordering of partial thromboplastin time tests, despite a significant posteducational change in surgeons' attitudes. In contrast, administrative restriction of coagulation test orders led to a 50% decline on four of the five study wards. We conclude that an educational intervention followed by administrative restriction may be considered an acceptable means of overcoming clinician reluctance to change well-established but redundant clinical policy.

Attitude of Health Personnel