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Biomedical subjects

B Pekić

Publications and source records attributed to B Pekić.

At least 19 recordsLinked to original sources
PubMed1991

The role of insulin-related substance in Hodgkin's disease.

An insulin-related growth-promoting substance was detected in the serum of a patient with Hodgkin's disease who suffered from severe hypoglycaemia, as well as in the supernatant of homogenized spleen tissue of the same patient. Low concentrations of this substance enhanced DNA synthesis of short-term-cultured spleen tumour cells obtained from the same patient, while the addition of anti-insulin antiserum interfered with that effect. Moreover, the preincubation of this insulin-related substance with the anti-insulin antiserum abrogated its stimulatory effect on tumour cell proliferation. Both insulin and the insulin-related substance bound to patients splenocytes to a similar extent. The data suggest that the insulin-related substance, found in this particular case of Hodgkin's disease, plays a role in tumour progression by an autocrine mechanism.

Blood Glucose↗
PubMed1987

Reversal of human myeloid leukemia cells into normal granulocytes and macrophages: activity and intracellular distribution of catalase.

The activity and intracellular distribution of catalase was studied in culture human myeloid leukemia cells before and after induction of differentiation with tunicamycin. Activity of catalase was increased 5-fold in acute myeloid leukemia cells (AML) and 3-fold in chronic myeloid leukemia cells in comparison with normal granulocytes. Tunicamycin induced differentiation of HL-60 line and primary AML line characterized by increase in phagocytic cells and changes to resemble mature myeloid cells. Fc receptors were also induced in cells after tunicamycin treatment. Induction of differentiation with tunicamycin decreased high activity of catalase in cultured leukemic cells. The results of digitonin titration experiments showed that in control granulocytes and differentiated leukemic cells most of the catalase activity is present in subcellular particles distinct from mitochondria or lysosomes. In contrast, the catalase activity in undifferentiated cells is present in the same compartment as the other cytosolic markers.

Catalase↗
PubMed1986

Electrophoretic distribution and dissociation into subunits of lactate dehydrogenase derived from human myeloid leukemia cells before and after induction of differentiation.

The electrophoretic distribution of lactate dehydrogenase (LDH) isoenzymes, Michaelis constant, reaction with substrate, and dissociation into subunits with guanidine hydrochloride was examined in undifferentiated and differentiated human myeloid leukemia cells. Differentiation was induced with 1/microgram/ml tunicamycin. Undifferentiated cells did not display phagocytic ability, and less than 5% of these cells had Fc receptors. After exposure to tunicamycin for 40 hr, 40% of these differentiated cells had Fc receptors, and 35% showed phagocytic activity after 160 hr. The majority of the LDH activity in the undifferentiated cells was found in fraction 3, and following differentiation almost a 50% reduction in LDH activity was observed in this fraction. In addition, LDH 3 isoenzyme levels were found to be greater in patients containing a high percentage of undifferentiated cells than in patients containing a high percentage of differentiated cells. Differentiated cells displayed LDH isoenzyme fraction pattern, Michaelis constant, and reaction with substrate similar to those found in the normal granulocytes. Differences in the dissociation of LDH into subunits with guanidine hydrochloride were found between undifferentiated and differentiated acute myeloid leukemia (AML) cells. Treatment with 0.75 M guanidine hydrochloride caused complete inactivation of LDH derived from normal differentiated cells, whereas similar treatment caused complete inactivation of LDH derived from AML or normal granulocytes. LDH isoenzymes derived from normal granulocytes and differentiated AML cells were also more sensitive to guanidine hydrochloride depression of fluorescence intensity. The sedimentation constant for single peak LDH at 5.5 M guanidine hydrochloride was calculated as 1.65 sec for differentiated and 1.70 sec for undifferentiated cells. The molecular weight of the polypeptide subunits for undifferentiated cells was 30,000 and for differentiated cells was 39,000. The apparent parallel between leukemic cells after induction of differentiation and normal granulocytes indicates that the leukemic cells retain their maturation potential when exposed to an inducer of differentiation.

Adult↗
PubMed1976

[Combined cytostatic therapy in the treatment of acute leukemias].

It was analysed 66 patients with different types of acute leukaemias treated on haematological department of Internal Clinics Mylitary Medical Academy during 1969-1974 years with combination chemotherapy. At 35 patients with acute lymphoblastic leukaemias it was obtain complete remission at 60%, and partial remission at 28,5%. Without the response was 11,4% patients. At 20 patients with acute myeloid leukaemias were induced only partial remission at 4 0% patients, and 60% patients were without the therapeutic response. The survival of patients with acute leukemias is presented. 88,4% patients with acute lymphoblastic leukaemias survived to two years, and 61,5% patients with acute myeloid leukaemias survived only to three months. None of the patients with acute myeloid leukaemias survived over one year.

Adolescent↗
PubMed1975

[Case of implantation of human fetal thymus on the immunological reactivity in patients with Hodgkin's disease].

Five patients with Hodgkin's disease (IV stage) were implanted with fetal human thymus. Implantation were performed under the fascia of rectus abdominis muscle. Thymuses were obtained from fetuses 4-5 month old in aseptic condition and stored in tissue culture medium 199, before implantation. Immunological studies carried out during 4-6 months, revealed the elevation of the number of the lymphocyte in the peripheral blood, normalization of the number of rosete forming cells (RFC) as well as the response of peripheral blood lymphocytes to phytohaemagglutinin (PHA) stimulation. Two patients had long improvement of immunological responsiveness, but the other 3 only a transitient one during the first month after implantation. The possibility of the immunologic treatment in the early stages of Hodgkin's disease is discussed.

Adolescent↗