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Biomedical subjects

Y Onozawa

Publications and source records attributed to Y Onozawa.

At least 73 records · Page 4Linked to original sources

Breakpoints in Philadelphia chromosome (Ph1)-positive leukemias.

We studied chromosome 22 breakpoints in 24 Philadelphia (Ph1)-positive leukemias. Nineteen of 21 patients with chronic myelogenous leukemia (CML) possessed a chromosomal break within the 5.8 kilobase (kb) breakpoint cluster region (bcr). Furthermore, in one of three cases of acute lymphocytic leukemia (ALL), we found a chromosomal rearrangement in the bcr locus. No chromosomal rearrangements were found in two cases of CML and two cases of ALL using several restriction enzymes. The bcr rearrangement is highly specific for CML. Further analyses will be necessary to determine whether some cases without bcr rearrangement have another specific locus of rearrangement. Two of three cases of CML with blastic crisis had rearrangement of the immunoglobulin gene and T-cell receptor gene. One CML patient with blastic crisis, who achieved complete remission but relapsed thereafter, was found to have the same immunoglobulin gene rearrangement in the blastic crisis and relapse phases, suggesting that the same clone was involved in both crisis and relapse.

Bacterial Proteins↗

Activation of platelets in cancer, especially with reference to genesis of disseminated intravascular coagulation.

Seventy-five cancer patients were evaluated on a scale of coagulation abnormalities related to DIC, one point given for each of the following criteria fulfilled and the score (0 to 4) being used. 1. Platelet count less than 150 x 10(3)/mu 1. 2. PT prolonged more than 1 sec over control or APTT prolonged more than 10 sec over control. 3. Fibrinogen less than 250 mg/dl (mean fibrinogen value of the cancer patients minus 1SD). 4. FDP greater than or equal to 20 micrograms/ml. The patients were distributed with 27% for score 0, 38% for 1, 20% for 2, 7% for 3 and 8% for 4. Platelet mode volume in score 4 was smaller than that of the other groups. Platelet aggregation by epinephrine was decreased in score 3 and 4 (P less than 0.01), while it was increased in score 0 (P less than 0.05). ADP-induced aggregation was increased in score 0 and 1 (P less than 0.01 - 0.05). The mean value of beta-thromboglobulin in cancer patients (44 +/- 24 ng/ml) was significantly higher than that of control (22 +/- 13 ng/ml) (P less than 0.01). These results suggest the existence of hyperfunction of platelets in cancer patients and possibility of a triggering mechanism of such activated platelets in the genesis of DIC in cancer.

Adult↗

Normalized natural killer (NK) cell activity in long-term remission of acute leukaemia.

NK cell activity was studied in 28 cases of acute leukaemia in remission. It was found that patients in long-term remission for 5 years or more had normal NK cell activity but those in remission for less than 5 years had significantly lowered activity. This suggests that patients with acute leukaemia had not been constitutionally deficient in NK cell activity. Low activity was augmented but not fully restored by interferon pretreatment in vitro. Therefore, the low NK cell activity observed during remission is not solely attributable to inadequate secretion of interferon in the host. It is suggested that the production of NK cells in bone marrow is impaired, or the function of NK cells is suppressed, by the leukaemia itself or by chemotherapeutic agents. Increased consumption of NK cells is also a possibility.

Acute Disease↗

Emperipolesis and annulate lamellae in erythroleukaemia.

The bone marrow in the erythraemic phase of 2 erythroleukaemia patients was studied electron microscopically. Emperipolesis of erythrocytes as well as annulate lamellae were revealed in the cytoplasm of the erythroblasts of these cases. It is assumed that these findings show a high rate of erythroblastic proliferation. This is the first report of emperipolesis within the erythroblast by erythroleukaemia. In addition, other various abnormalities, namely, nuclear-cytoplasmic asynchrony, nuclear bleb or cleft formation, abundant glycogen particles and ferruginous micelles in mitochondria such as described in some previous reports, were also recognized.

Adult↗