Hitoshi Sakakibara

Ultrastructural and ultracytochemical differences between transient myeloproliferative disorder and megakaryoblastic leukaemia in Down's syndrome

Ultrastructural and ultracytochemical studies were performed on blast cells from 12 Downs syndrome neonates with transient myeloproliferative disorder (TMD) and 13 Downs syndrome patients with megakaryoblastic leukaemia (MKL), in order to clarify the cytological characteristics of these cells. Average platelet peroxidase‐positivity in blast cells of TMD patients was similar to that found in cases of MKL. Blast cells from subjects with TMD contained a number of different granules, namely, alpha granules, those that were myeloperoxidase (MPO)‐positive, electron‐lucent or basophil‐like, and those containing membrane components or ferritin particles. On the other hand, granules found in the blast cells of MKL patients with Downs syndrome included the electron‐lucent variety, those with membrane components and a few that were basophil‐like, but not alpha and MPO‐positive granules nor those containing ferritin particles. A demarcation membrane system was observed in blasts from the TMD group, but not in the MKL group.

Ultrastructural and ultracytochemical differences between megakaryoblastic leukemia in children and adults analysis of 49 patients

Background. Acute megakaryoblastic leukemia (AMKL) has two peaks in distribution of incidence (in adults and children 1 to 2 years of age) and is frequently seen in children with Down syndrome. The current study was undertaken to disclose whether there were any differences between these groups.

Ultrastructural Cytochemistry of Congenital Basophilic Leukemia

A newborn infant was diagnosed as having congenital basophilic leukemia, an extremely rare disorder, by examination of cord blood. An ultrastructural cytochemical study was conducted on the blasts of the infant. Granules of basophil blasts showed ultrastructural characteristics of immature basophil granules and were similar in size to those of normal basophil granules but were fewer in number in each profile. Histochemical studies showed weak reactions for acid mucopolysaccharides and neutral glycoconjugates in the granules, but they were negative for peroxidase. Acid phosphatase was markedly positive. The findings of congenital basophilic leukemia are different from those of basophils in chronic myelocytic leukemia. The patient underwent induction therapy with vincristine and prednisone and has been in complete remission for 21 months.

Giant mitochondria in acute lymphocytic leukemia

Giant mitochondria were observed in 2 cases among 28 cases of ALL by electron microscopy. The cristae of the giant mitochondria in the leukemic cells were irregularly arranged, decreased in number, and formed concentric circles. Several morphological abnormalities were also observed in the normal mitochondria. Morphometric analysis of the mitochondria in the 2 patients disclosed that the sizes of mitochondria were well distributed from small to large and thus, the mitochondria could not be divided into different populations. Also, there were no clear differences in the distribution of shape between normal and giant mitochondria. These results suggest that the giant mitochondria were derived from normal mitochondria. Since they were observed before the initial treatment, they did not developed as a result of drug action.

Ultrastructural and ultracytochemical identification of the small granules in basophils from human and animals

SummaryThe small granules in the basophils obtained from humans and animals were compared ultrastructurally and cytochemically. Cytochemically, there were no qualitative differences among the small granules in the species examined.The small granules in humans, guinea pigs and rabbits were approximately 0.16–0.22 μm, 0.15–0.17 μm, and 0.12–0.16 μm, in diameter, respectively. In all species small granules had a single unit membrane and contained some amorphous material. In immature cells many of the small granules were distributed near the Golgi apparatus, while in the mature cells many of them were found around the periphery of the cell. There were no morphological or cytochemical differences between the small granules of the immature cells and those of the mature cells.The negative reaction in the dialysed iron and high iron diamine methods showed that the small granules did not have acid mucopolysaccharides or sulfated glycoconjugates. The strong reaction of the small granules of all species to the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) test, which was especially prominent in rabbit, showed that the small granules have many periodate-reactive neutral glycoconjugates but no acidic glycoconjugates. Enzyme cytochemistry revealed that the small granules are negative for peroxidase and catalase but positive for acid phosphatase.

Ultrastructural effects of granulocyte colony stimulating factor (G-CSF) and macrophage colony stimulating factor (M-CSF) on rat neutrophils and monocytes

Human granulocyte colony stimulating factor (G-CSF) and macrophage colony stimulating factor (M-CSF) were administered intravenously to rats, and their effects on neutrophils and monocytes were examined by electron microscopy. G-CSF increased the number of cytoplasmic granules in neutrophils. It also enhanced maturation of the nuclear shape in the neutrophils, while chromatin condensation and peroxidase distribution remained immature. M-CSF induced proliferation of monocytes in peripheral blood and bone marrow, but did not affect morphology or distribution of peroxidase reactivity.

11;13 Translocation in Acute Nonlymphocytic Leukemia

In this paper, we report on a 9-year-old girl with acute nonlymphocytic leukemia (FAB-M5) with a rare chromosome abnormality, t(11;23)(q21;p11). Peripheral blood showed Hb 7.5 g/dl, WBC 3,600 cells/microliters (10% blasts), and platelet count 110 x 10(3) cells/microliters. The bone marrow aspirates showed normal cellularity with 36.7% blasts. On morphological characteristics, micromegakaryocytes were observed, and on chromosome examination the karyotype was shown to be 46,XX,t(11;13)(q21;p11) in all metaphases.