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Biomedical subjects

B Ramot

Publications and source records attributed to B Ramot.

At least 109 records · Page 6Linked to original sources
PubMed1983

Monocyte PGE2 secretion in Hodgkin's disease and its relation to decreased cellular immunity.

The secretion of PGE2 from monocytes of newly diagnosed patients with Hodgkin's disease (HD) was compared to that of patients in remission, who were not receiving either chemotherapy or radiotherapy, and normal controls. We found that monocyte monolayers of some patients, both newly diagnosed and those in remission, secreted markedly elevated levels of PGE2. The lymphocyte proliferative response to PHA was increased to a similar extent in both newly diagnosed patients and those in remission when cultured in the presence of indomethacin. PGE2 concentrations in the medium of mononuclear cultures correlated with the lymphocyte proliferative response to PHA (P less than 0.05). However, no correlation of monocyte PGE2 production with decreased E rosette forming lymphocytes, anergy or clinical stage could be demonstrated. We suggest that PGE2 secretion by monocytes is indicative of an 'activated' state of these cells. It is, however, unlikely that PGE2 is the only molecular species responsible for the decreased cellular immune function in HD. 'Activated' monocytes may be part of the immune response in this disease and may be responsible for the decreased cellular immunity.

Adolescent↗
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↗
PubMed1982

Variation of (2'-5') oligo A synthetase level in lymphocytes and granulocytes of patients with viral infections and leukemia.

Using a simplified technique for the determination of oligoisoadenylate synthetase activity, we have compared the cellular level of this interferon (IFN)-induced enzyme in multiple samples of peripheral blood leukocytes. In mononuclear cells (PBMC) of healthy donors the enzyme level was remarkably constant, but in the cells of about 85% of patients with viral infections enzyme activity was significantly elevated. In contrast, the incidence of elevated activity in bacterial infections was low. Synthetase activity could be also detected in granulocytes, although normally its level in these cells was considerably lower than in PBMC. A sharp increase in the enzyme level in granulocytes was found in cells exposed in vitro to IFN, as well as in cells from patients undergoing IFN therapy. Increased synthetase activity was also detected in the granulocytes of patients with viral infections. We have also determined the level of the enzyme in patients with various types of leukemias. In a large proportion of the patients with acute lymphoblastic leukemia (ALL) we found severely decreased enzyme levels (10-20% of control value). The decreased activity could usually be correlated to predominance of blast cells in the peripheral blood.

2',5'-Oligoadenylate Synthetase↗
PubMed1982

Pretreatment prognostic factors and hospitalization periods in childhood acute lymphoblastic leukemia.

Pretreatment prognostic factors and hospitalization periods were analyzed in 57 consecutive children who had acute lymphoblastic leukemia diagnosed between 1967 and 1977, and who were followed up for at least two years. We investigated possible correlations between white blood cell (WBC) count, organomegaly and mediastinal enlargement at diagnosis, as well as age and sex, with the length of first remission and survival. Children presenting with a combination of all of the following four risk factors--WBC count greater than or equal to 50,000/mm3, enlarged mediastinum, spleen and liver greater than or equal to 3 cm below the costal margin--comprised a poor-prognosis group, in which boys predominated. Age in this small group of patients had no correlation with prognosis. On the other hand, no specific risk factor was predictive for survival in the 48 children who had less than four of the risk factors. In this better-prognosis group, children less than 2 yr and greater than 10 yr had a higher relapse rate than those of intermediate ages, and girls had a significantly better prognosis than boys. These results indicate that age and sex are intercorrelated with the above risk factors, so that analysis of the effect of a single risk factor or even a combination of two factors can be misleading. In the light of these findings, an interpretation of the discrepancies in the literature is suggested. Of interest, too, is the poor prognosis and the high frequency of T-cell leukemia among Arab children. Finally, we stress the importance of day-care facilities that enable shorter hospitalization periods and improve the quality of life.

Antibiotics, Antineoplastic↗
PubMed1982

The effect of human monocytes and macrophages on lymphocyte proliferation.

Human monocytes suppressed both the phytohaemagglutin (PHA) or antigen-induced lymphocyte proliferative response, when the monocyte: lymphocyte ratio was increased or when the monocytes were stimulated with zymosan or endotoxin. The effect of monocytes on autologous lymphocyte proliferation was compared with that of macrophages obtained by culturing monocytes in vitro for 7 days. The lymphocyte proliferative responses were increased in the presence of macrophages, however, neither increasing their number nor stimulation by zymosan or endotoxin altered the autologous lymphocyte proliferative response to PHA or purified protein derivative (PPD). The PGE2 concentration in the medium of both the cultured monocytes or macrophages activated by zymosan and endotoxin rose markedly without a corresponding suppressor effect on lymphocyte proliferation in the presence of macrophages in the culture. Thus it seems that while PGE2 is a useful marker of mononuclear phagocyte activation, other molecular species are of importance in determining the lymphocyte proliferative response to mitogens and antigens.

Candida↗
PubMed1981

Chronic lymphatic leukemia terminating in acute myeloid leukemia: review of the literature.

A case of acute myeloid leukemia supervening upon a long-standing stable chronic lymphatic leukemia (CLL) diagnosed ten years earlier, is described. Thirty-three cases of acute leukemia terminating CLL were reported. All but three were treated prior to the emergence of the acute leukemia. The question of whether acute leukemia and other malignancies are more frequent in CLL is still controversial. The literature is reviewed.

Aged↗
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↗
PubMed1981

Effect of levamisole, thymic humoral factor and indomethacin on e-rosette formation of lymphocytes in Hodgkin's disease.

The percent of E-rosette forming cells in the peripheral blood of 60 patients with Hodgkin's disease was significantly lower than in control subjects: 46.4 +/- 12.3 vs. 62. 4 +/- 12.5. Preincubation of the mononuclear cells with levamisole, thymic humoral factor (THF) or indomethacin restored E-rosette formation to normal levels. When monocytes were removed from the mononuclear cell preparations prior to incubation, levamisole and THF retained their activity, whereas indomethacin was inactive. These results suggest a direct effect of levamisole and THF on lymphocytes in Hodgkin's disease, whereas indomethacin requires the mediation of monocytes, similarly to its reported effects on other cellular immune responses in Hodgkin's disease.

Hodgkin Disease↗
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↗
PubMed1979

Interaction of peanut agglutinin with normal human lymphocytes and with leukemic cells.

The interaction of peanut agglutinin (PNA) with human thymocytes, peripheral blood lymphocytes, and peripheral blood cells of various types of leukemia was investigated by using fluorescein isothiocyanate-conjugated PNA. The majority of human thymocytes (60-80%) bind the lectin. The major subpopulation of thymocytes that is PNA-positive was separated from the PNA-negative cells by differential agglutination with the lectin. The two thymocyte subpopulations were tested in the mixed lymphocyte reaction and with the phytohemagglutinin of Phaseolus vulgaris. The poor response of the PNA-positive thymocytes to these stimuli indicates that these thymocytes are functionally immature. The fluorescein isothiocyanate-PNA-binding test with peripheral blood lymphocytes of leukemic patients revealed that in most acute leukemias the PNA receptor is exposed on the blastic cells, whereas in most cases of chronic leukemia the peripheral blood lymphocytes are PNA-negative. The validity of PNA as a marker of immature blood cells and its potential clinical application are discussed.

Arachis↗
PubMed1979

Ferritin deposits in peripheral blood lymphocytes of Hodgkin's disease patients.

In view of the reported associations of Hodgkin's disease and ferritin, an electron microscopic study of the peripheral blood lymphocytes of these patients was done. In 5 out of the 6 patients studied intracellular ferritin deposits were seen. No such deposits were seen in the lymphocytes of healthy subjects or in those of a patient with beta-thalassemia. The lymphocyte ferritin accumulation in Hodgkin's disease can arise either from increased synthesis or from phagocytosis.

Ferritins↗
PubMed1979

Adenosine deaminase activity of normal lymphocytes and leukemic cells.

Adenosine deaminase (ADA) activity was determined in peripheral blood T cells, thymocytes and blasts of 42 acute leukemia patients. Thymocytes had higher ADA activity than mature peripheral blood T cells. B ALL (acute lymphoblastic leukemia) cells had significantly lower activity compared with T ALL and non-B, non-T cells. The latter had a wide range of enzymatic activities but mostly in the T cell range. Based on these results, as well as on assays of B and T cell lines, it seems that thymus-derived cells--and especially prethymic and immature T cells--have high ADA activity. This finding could be useful in subtyping the heterogeneous group of non-B, non-T ALL.

Adenosine Deaminase↗
PubMed1979

Role of radiotherapy and chemotherapy in the treatment of lymphomas.

The recent developments and results of treatment in Hodgkin's disease suggest that staging laparotomy is indicated in certain selected groups of patients and should not be performed routinely in patients whose therapy is unlikely to be changed by the findings.Early stage nodal Hodgkin's disease is best treated by extended radiotherapy. The exact role of adjuvant chemotherapy is not settled, but there are certain groups of high-risk patients who should receive chemotherapy, such as those with extensive mediastinal disease or advanced IIIA patients. In the advanced stages, chemotherapy assumes the primary role and with the MOPP programme (chlormethine, vincristine, procarbazine, and prednisone), alone or alternating with ABVD (doxorubicin, bleomycin, vinblastine, and imidazole carboxamide), a substantial number of patients can be controlled or cured.The therapeutic approach to non-Hodgkin's lymphoma should be guided mainly by the histological findings, favourable or unfavourable, and to a lesser degree also by the stage of the disease. In these patients, chemotherapy rather than radiotherapy is the treatment of choice. In the favourable histology group, a conservative approach is usually justified in the majority of patients, while in the unfavourable histology group, aggressive combination chemotherapy containing adriamycin is the recommended therapy.In underprivileged populations, the abdominal and intestinal localization of lymphomas is more common than in Europe and North America. Two lymphomas of special interest are Burkitt's lymphoma and intestinal lymphoma in their varying aspects. In both diseases, the importance of environmental factors is highly suggestive. Referral of such patients to centres involved in the management of these diseases is essential.

Antineoplastic Agents↗