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Biomedical subjects

F Brok-Simoni

Publications and source records attributed to F Brok-Simoni.

At least 73 records · Page 4Linked to original sources
PubMed1988

More than two immunoglobulin heavy chain J region genes in the majority of infant leukemia.

Congenital and infant leukemia are rare conditions associated with a very poor prognosis due to the high frequency of adverse clinical and laboratory parameters. As the occurrence of multiple immunoglobulin heavy chain hybridization band in childhood leukemia has been associated with poor prognosis, we studied whether it was present in this type of leukemia as well. Seven cases were examined, 4 of them less than 7 months of age. The immunophenotype was lymphoid in 5 and hybrid in 2. Most had abnormal karyotypes. In 5 of the 7, including all with congenital leukemia, an immunoglobulin heavy chain J region multiband pattern was found by Southern blot. The multiband pattern, whether primary or due to clonal evolution, seems to be associated with poor prognosis.

Adolescent↗
PubMed1987

PGI*3(Israel), a new, unstable allele in the phosphoglucose isomerase system.

Phosphoglucose isomerase (PGI) and 16 other biochemical genetic markers were studied in an Israeli-Arab family previously described for hereditary deficiency of adenylate kinase (AK) and glucose 6-phosphate dehydrogenase (G6PD). In this inbred family a rare PGI*3 allele was observed in 11 of 32 members tested, indicating an autosomal codominant inheritance. The electrophoretic mobility of this allele is similar to that of the PGI*3 allele found in Indian populations, but unlike the Indian allele, it has a very low specific activity and heat stability. This PGI*3 allele, designated PGI*3 (Israel), seems to be a different unstable mutation and along with AK and G6PD deficiencies seems to be associated with severe anaemia.

Alleles↗
PubMed1987

Molecular analysis of Burkitt's leukemia in two hemophilic brothers with AIDS.

In two hemophilic brothers infected by the human immunodeficiency virus (HIV), Burkitt's leukemia developed within 1 year. Both patients were treated by aggressive chemotherapy, and both are still in complete remission for 23 and 14 months, respectively. Sera from both brothers contained anti-HIV antibodies. However, DNA extracted from the tumor cells, when analyzed by Southern blot using a cloned HIV probe, did not reveal HIV-related sequences. Hybridization experiments with an Epstein-Barr virus (EBV) probe revealed the presence of EBV-specific sequences in the tumors' DNA. In both patients' tumors rearranged c-myc genes were found. The rearrangements occurred in both genes 3' to the third exon of c-myc, thereby suggesting that a variant chromosomal translocation took place in both cases. Indeed, karyotype analysis of the malignant cells of one of the patients revealed the variant t(2:8) translocation. In contrast to the majority of Burkitt's tumors carrying this translocation, which are kappa light-chain producers, cells of our patient expressed lambda chains. Furthermore, in both cases the lymphoblasts carried IgG on the surface, again an unusual finding in Burkitt's tumors. Finally, because both patients had an identical HLA phenotype, the role of genetic factors in the development of such tumors should be considered.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Acute lymphoblastic leukemia subtypes in Israel: the Sheba medical center experience.

During the period from 1978 to 1981, 52 patients with ALL were diagnosed and treated at the Chaim Sheba Medical Center. Using standard cell markers to subtype the blasts, 49 of the patients could be classified: 16 were found to be T-cell ALL, 10 common ALL, five null ALL, four pre-B and 14 were partially characterized as non-B, non-T. Analysis of the series revealed two distinctive features: high prevalence (30%) of T-cell ALL among both Jews and Arabs and a high proportion, two-thirds, of high risk patients due to high initial WBC counts, unfavourable age or T-cell characteristics. The minimal incidence of ALL among the Gaza Strip Arab children during the study period is 4:100,000, which is close to the incidence in the Western world. During previous years the leukemia incidence in the Gaza Strip was very low while the most common lymphatic malignancies were Burkitt tumor and other non-Hodgkin lymphomas.

Adenosine Deaminase↗
PubMed1981

Nucleoside phosphorylase activity in normal and leukemic cells.

Nucleoside phosphorylase (NP) activity was assayed in normal peripheral blood lymphocytes, mature and immature thymocytes fractionated by peanut agglutinability, CLL lymphocytes, and ALL lymphoblasts to determine applicability as an enzymatic cell marker. Circulating lymphocytes had the highest activity, immature thymocytes the lowest, and mature thymocytes were intermediate in NP level. This suggests an increase in NP activity with T-cell maturation. CLL lymphocytes showed very low activity, confirming previous reports. However, the NP activity of the lymphoblasts of 40 patients with B, T, and non-B, non-T ALL was similar to that of normal peripheral blood lymphocytes and could not be used to discriminate between these subgroups of ALL.

B-Lymphocytes↗
PubMed1980

Viral hepatitis with extreme hyperbilirubinemia, massive hemolysis and encephalopathy in a patient with a new G6PD variant.

Extreme hyperbilirubinemia, massive hemolysis and hepatic encephalopathy were reported in a G6PD-deficient patient with viral hepatitis. Investigation of the G6PD properties revealed that this patient's enzyme represented a hitherto undescribed variant (Bnei Brak), characterized by heat stability and a unique triphasic pH-related enzyme activity curve. It is possible that the marked hemolytic process in this patient was enhanced by a further decrease in the activity of the already deficient enzyme during acidosis.

Adolescent↗
PubMed1977

Adenosine deaminase (ADA) activity in lymphocytes of normal individuals and patients with chronic lymphatic leukaemia.

Adenosine deaminase (adenosine aminophydrolase, ADA) activity was found to be low in lymphocytes of chronic lymphatic leukaemia (CLL) patients compared to normal lymphocytes. This was determined on 42 controls and 49 CLL patients. The mean activity in normal lymphocytes was found to be 4.35 +/- 3.34 mumol/h/10(8) cells while in CLL cells it was 2.45 +/- 2.54 mumol/h/10(8) cells.

Adenosine Deaminase↗
PubMed1976

Blood leucocyte enzymes. III. Diurnal rhythm of activity in isolated lymphocytes of normal subjects and chronic lymphatic leukaemia patients.

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6 phosphate glucono dehydrogenase (6 phospho-D-gluconate: NADP oxidoreductase, 6PGD) lactate dehydrogenase (D-lactate: NAD oxidoreductase, LDH), glutamate oxaloacetate transaminase (L-aspartate: 2-oxo-glutarate aminotransferase, GOT) and hexokinase (ATP: D-hexo-6-phosphotrans-ferase, Hx) were measured over 24 h in isolated lymphocytes of normal subjects and in white cells of patients with chronic lymphatic leukaemia (CLL). The activitty patterns of all enzymes in the normal lymphocytes were similar. A computed pattern of all the results exhibited a circadian rhythm of activity with the highest level at 16.00 hours. The oscillations in the activities of the same enzymes in the CLL cells differed among the patients, although all the enzymes of the same individual showed a similar diurnal rhythmic pattern. All peaks in this group appeared between 20.00 and 08.00 hours. The possible importance of these observations in setting up therapeutic schedules was raised.

Aspartate Aminotransferases↗
PubMed1976

The diurnal rhythm of enzymes in human red cells.

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6-phosphogluconate dehydrogenase (6-phospho-d-gluconate: NADP oxidoreductase, 6PGD), hexokinase (ATP:D-hexose 6-phosphotransferase, HK), lactic dehydrogeanse (L-lactate: NAD oxidoreductase, LDH) and aspirate aminotransferase (L-aspartate: 2-oxoglutarate aminotransferase, Asp.T) were determined in red blood cells of 11 healthy individuals. The determinations were carried out on samples drawn every 4 h over a 24 h period. The activities of G6PD, 6PGD, LDH and Asp.T exhibited a semi-circadian rhythm, namely, two peaks of activity during 24 h while HK activity demonstrated a true circadian rhythm. In addition a polymorphism of the G6PD and LDH activity patterns was observed. The implications of a biological clock in enucleated cells are discussed.

Aspartate Aminotransferases↗
PubMed1976

A family with red cell pyrimidine 5'-nucleotidase deficiency.

Congenital hemolytic anemia associated with pyrimidine 5'-nucleotidase deficiency is reported in two siblings. Both have had moderate chronic hemolytic anemia, splenomegaly, and jaundice since early infancy. The peripheral blood smear is characterized by striking red cell basophilic stippling. As this feature has been found in all previously reported cases, it should be the clue to the diagnosis.

Anemia, Hemolytic, Congenital↗
PubMed1975

Blood leucocyte enzymes. II. Activities at 8-9 a.m. in cells of normal subjects, chronic lymphatic leukaemia and chronic myeloid leukaemia patients.

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6-phosphogluconate dehydrogenase (6-phospho-D-gluconate: NADP oxidoreductase, 6PGD), hexokinase (ATP: D-hexose 6-phosphotransferase, Hx), lactate dehydrogenase (D-lactate: NAD oxidoreductase, LDH). glutamate oxaloacetate transaminase (L-aspartate: 2 oxoglutarate aminotransferase, GOT) and dihydrofolate reductase (DHFR) were measured at 8 a.m. in leucocytes of healthy individuals and patients with chronic myeloid leukaemia (CML), chronic lymphatic leukaemia (CLL), myelofibrosis with myeloid metaplasia and polycythaemia vera. In view of the heterogeneity of the leucocyte populations in these conditions, the enzyme activities were correlated to the number of immature cells in CML and to the percentage of lymphocytes in CLL. No differences in the enzyme activities were found between the white cells of healthy individuals, myelofibrosis with myeloid metaplasia and polycythaemia vera. In CML the activities of all enzymes except GOT correlated directly with the number of immature cells; an inverse correlation with the number of lymphocytes was observed in CLL. GOT was the only enzyme whose activity correlated with the number of lymphocytes in the cell suspension. Furthermore, a significantly higher activity of this enzyme was found in Ficoll-isolated CLL lymphocytes as compared to normal lymphocytes.

Aspartate Aminotransferases↗
PubMed1975

Complement-sensitive red cells in aplastic anemia.

In view of the clinical association of aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH), the complement-dependent lysis of the youngest red cells of AA patients was studied. A complement-sensitive population of young red cells was found in five of six patients with AA. These cells were rapidly cleared from the circulation and were undetectable in the oldest cell fraction. Such cells were not found in normal controls or in a variety of hematologic disorders, with the exception of PNH. This study suggests that in most patients with AA, even without any clinical manifestations of PNH, there is a population of dyserythropoietic, short-lived complement-sensitive cells.

Acetylcholinesterase↗