Induction of ornithine decarboxylase by treatment of guinea pig lymphocytes with phospholipase C

Treatment of guinea pig lymphocytes with Clostridium perfringens phospholipase C but not with Naja naja snake venom phospholipase A2 increased ornithine decarboxylase activity. The increase in ornithine decarboxylase activity was suppressed by actinomycin D or cycloheximide, suggesting that de novo syntheses of RNA and protein are necessary for the increase in the enzyme activity. These results suggest that the activation of phospholipase C rather than that of phospholipase A2 is responsible for induction of ornithine decarboxylase during lymphocyte transformation.

Factors influencing survival in Philadelphia chromosome positive chronic myelocytic leukemia

The prognostic value of several clinical and hematologic features, recorded at diagnosis, in chronic phase Ph1 positive chronic myelocytic leukemia (CML), was analyzed in 135 patients using life-table analysis. About one third of patients were atomic bomb survivors and they had been examined twice a year before the diagnosis of CML. In general, features representing tumor cell burden, i.e., leukocyte count, spleen sizes, and absolute differential cell counts of all granulocyte series cells except myeloblasts affected survival significantly, while sex, age, hemoglobin, platelets and features representing quality of leukemia, i.e. neutrophils alkaline phosphatase score, percent Ph1 positive cells in bone marrow, and percent differentials of all granulocyte series cells except promyelocytes and segmented neutrophils were all insignificant. Multivariate life-table analysis was also performed using age, sex, hemoglobin, platelets, and leukocyte count as predictor variables. The result was that leukocyte was the single most important factor in this analysis and annual death rates between low risk (risk ratio less than 0.8) and high risk (risk ratio greater than 1.4) differed considerably up to four years from diagnosis, indicating our formula to calculate risk ratio is valid as a grading parameter of chronic phase Ph1 positive CML within four years from diagnosis.

Induction of ornithine decarboxylase in guinea pig lymphocytes by the divalent cation ionophore A 23187. Effect of dibutyryladenosine 3',5'-monophosphate

The divalent cation ionophore, A23187, at a concentration of 0.25 microgram/ml, enhanced influx of Ca2+, activity of ornithine decarboxylase and incorporation of [3H]thymidine into DNA of guinea pig lymphocytes. Combined treatment of cells with A23187 and dibutyryladenosine 3',5'-monophosphate (Bt2cAMP) augmented these three events. A23187 at a concentration of 0.06 microgram/ml was insufficient for induction of ornithine decarboxylase stimulated neither Ca2+ influx nor [3H]thymidine incorporation, but stimulated Ca2+ efflux. A23187 (0.06 microgram/ml) in combination with Bt2cAMP caused a marked induction of ornithine decarboxylase and stimulation of [3H]thymidine incorporation into DNA. When the time of Bt2cAMP addition was delayed after A23187, the stimulation of ornithine decarboxylase activity decreased. Washout of Bt2cAMP from cell culture earlier than 4 h of incubation caused a reduction in the stimulatory effect of Bt2cAMP. These results suggest that raising concentrations of cytoplasmic Ca2+ and cellular cAMP are important to some initial events leading to induction of ornithine decarboxylase and these biochemical changes are obligatory sequential steps for stimulation of DNA synthesis.

Regulation of ornithine decarboxylase activity by cyclic AMP in guinea pig lymphocytes: transcriptional and post-transcriptional control

Induction of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) in phytohemagglutinin-stimulated lymphocytes was suppressed by the administration of dibutyryl cyclic AMP and 3-isobutyl-1-methylxanthine. This inhibition of ornithine decarboxylase induction was overcome by removing the chemicals from the lymphocyte culture. However, the recovery of ornithine decarboxylase induction by washout of the chemicals did not occur when actinomycin D, cordycepin or alpha-amanitin was added to the cultures, suggesting that the synthesis of mRNA directed to ornithine decarboxylase was reduced in dibutyryl cyclic AMP- and 3-isobutyl-1-methylxanthine-treated cells. Moreover, the decay of ornithine decarboxylase activity in the cells treated with phytohemagglutinin plus dibutyryl cyclic AMP and 3-isobutyl-1-methylxanthine was significantly slower than that of control cells stimulated with phytohemagglutinin alone. The difference of the decrease in ornithine decarboxylase activity between dibutyryl cyclic AMP- and 3-isobutyl-1-methylxanthine-treated and control cells was observed when actinomycin D was added to the culture, but not when cycloheximide was added. Therefore, prevention of ornithine decarboxylase decay by cyclic AMP may be post-transcriptional events, but not post-translational events.

The effect of vitamin E on platelet kinetics of stroke-prone spontaneously hypertensive rats (SHRSP)

The platelet survival time was shortened in stroke-prone spontaneously hypertensive rats (SHRSP) at 10 weeks of age on feeding the regular diet but it was normalized on administering the vitamin E-supplemented diet. Platelet survival time was normal in stroke-resistant spontaneously hypertensive rats (SHRSR) at 10 weeks of age on feeding the regular diet but it was shortened when supplying the vitamin E-free diet. The maximal uptake of 75Se-selenomethionine by platelets was increased in SHRSP at 10 weeks of age on feeding the regular diet. It was further increased in SHRSP on feeding the vitamin E-free diet. On the other hand, the increased maximal uptake of 75Se-selenomethionine by platelets was normalized in SHRSP on feeding both the vitamin E-supplemented diet and the vitamin E-supplemented diet after administering the vitamin E-free diet. Therefore, we concluded that the deficiency of vitamin E brought about the shortening of platelet survival time and enhanced platelet production.

Biochemical activities of lysosomal acid hydrolases in leukemic cells

The biochemical activities of 8 lysosomal acid hydrolases in leukemic cells from 48 patients were examined. Characteristic alterations were found in alpha-mannosidase, beta-galactosidase and N-acetyl-beta-glucosaminidase activities of leukemic cells. The level of alpha-mannosidase activity was much higher in myelo(mono)genous leukemias (AML, AMoL, AMMoL, CML and CMMoL) than in lymphogenous ones (ALL, T-cell leukemia, hairy cell leukemia and CLL) without exception. The beta-galactosidase activity also differed as a result of alpha-mannosidase, except in T-cell leukemia. In T-cell leukemia it was within the range of normal lymphocytes, but in the other lymphogenous leukemias it was significantly below normal. N-acetyl-beta-glucosaminidase activity in myelo(mono)genous leukemic cells was above the range of normal granulocytes. The changes in these enzyme levels were consistent. The lymphocytic or myelocytic nature of three cases of acute undifferentiated leukemia could be determined by enzyme studies. In two cases it was lymphocytic and in one it was myelocytic. The enzymatic abnormalities were also found in morphologically mature neutrophils from patients but not only chronic types (CML, CMMoL) but also acute types (AMoL, AMMoL) of leukemias, and were similar to those of their respective leukemic cells. Analysis of lysosomal enzymes (at least three of those mentioned above), can elucidate one of the biochemical properties of leukemic cells and may be valuable in the differentiation of leukemias.

In vivo and in vitro activity of neutrophil alkaline phosphatase in acute myelocytic leukemia with 8;21 translocation

Cytogenetic studies were made on 160 patients with acute nonlymphocytic leukemia (ANLL) between 1963 and 1979, of whom 115 had acute myelocytic leukemia with 67 patients showing aneuploidy (58.3%). Among these, 24 patients were found to have similar chromosome alterations that appeared to involve specifically chromosomes 8 and 21. Banding studies on at least 7 of these patients confirmed the presence of a translocation between these two chromosomes. Of 160 ANLL patients, 142 were scored for neutrophil alkaline phosphatase (neutrophil AP) at the time of diagnosis. Fifty-nine patients showed a low neutrophil AP score, 42 a normal value, and 41 a high value. All patients with 8;21 (or C/G) translocation had a low neutrophil AP score and leukemic cells with maturation (M2 of FAB classification) in the bone marrow. In vitro liquid culture for 2 wk of 8;21 translocated leukemic cells revealed no increase of neutrophil AP activity nor increase of mature granulocytes, whereas 9;22 translocated chronic myelocytic leukemia cells with a low neutrophil AP score did so. Neutrophil AP score at the time of diagnosis in acute myelocytic leukemia is very useful for detecting 8;21 translocation AML and for studying the pathophysiology and genetic alterations of the characteristic subgroup of AML with 8'21 translocation.

Chromosome aberrations in B lymphocytes of atomic bomb survivors

Although chromosome aberrations in T lymphocytes and bone marrow cells have been reported in atomic bomb survivors, the presence of chromosome abnormalities has not been demonstrated in B lymphocytes because of the technical difficulties involved in B-lymphocyte separation. A method for detecting chromosome aberrations in B lymphocytes was established by "stimulation" of B lymphocytes with Epstein-Barr virus (EBV) instead of "separation" of B lymphocytes by rosette formation. The EBV-stimulated lymphocytes were isolated as single colonies in soft agar and transferred to liquid culture for further cell growth. The EBV-stimulated B lymphocytes of two heavily exposed survivors showed 50% and 12.5% chromosome abnormalities 30 yr after exposure to the effects of the atomic bomb. The former patient seemed to have a karyotypically abnormal clone of B lymphocytes in vivo. The method used in this study and the evidence of chromosome aberrations in B lymphocytes for long periods after radiation exposure will be useful and important in elucidating the malignant processes of acute lymphocytic leukemia, B-cell lymphoma, and multiple myeloma among high-risk groups having a history of accidental or therapeutic exposure to radiation or radiomimetic drugs.