• Genomics & Informatics
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• v.3 no.1
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• pp.8-14
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• 2005

Although much is known about the molecular biology of platelets, the megakaryocytes' (MKs) molecular biology was not understood so well because of their rareness. By the cloning and characterization of thrombopoietin (TPO), which is the principal regulator of the growth and development of the MKs, researches on the MKs have been growing rapidly. To understand megakaryocytopoiesis, we investigated the gene expression profile of the MKs using oligonucleotide microarray where 10,108 unique genes were spotted. Comparing the fluorescence intensities of which ratio is $\ge$ ${\mid}2{\mid}$, 372 genes were up-regulated and 541 genes were down-regulated in MKs. For confirmatory expression, RNase protection assay (RPA) establishing abundant apoptotic gene expression was carried out. In MKs, many of the known genes, including several platelet related genes, GATA binding protein were highly expressed. Particularly, TGF beta, clusterin (complement lysis inhibitor), and thymosin beta 4 (actin-sequestering molecules) were expressed highly in MKs. As MKs specific expressed genes may regulate normal and pathologic platelet (and/or MK) functions, the transcript profiling using microarray was useful on molecular understanding of MKs,

• Toxicological Research
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• v.8 no.2
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• pp.179-189
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• 1992

This study was carried out to investigate the immunopathological effects of 7,12-Dimethylbenz[a]anthracene(DMBA) on spleen in mice. DMBA was administered subcutaneously to BALB/C mice by interscapular single injection of 50 or 100${\mu}g/g$ of body weight. Each DMBA treatment group and additional corn oil control group of mice were studied on day 1,3,7,14 and 21 following the injection of DMBA. DMBA treatment resulted in marked decrease in weights and cellularity of spleen. Spleen weights showed the greatest decrease at 14days after 50${\mu}g/g$ DMBA treatment, and at 21days after 100${\mu}g/g$ DMBA treatment. Spleen cellularity was similarly deceased in comparison with spleen weights. Spleen showed morphologically no typical changes throughout the experiment after 50${\mu}g/g$ DMBA treatment. Following the treatment of 100${\mu}g/g$ DMBA the spleen showed severe fibrosis, hemosiderin precipitation, and megakaryocytes decrease in red pulp at 14 days, while hemopoietic function was partly restored in addition to the appearance of a few megakaryocytes at 21 days. In spleen sections treated with antibodies to IgM or Thy1.2, lymphocytes strongly stained with IgM antibody were infiltrated around the central artery within the white pulp, and T-lymphocytes of periarterial lymphatic sheath (PALS) were diminished and destructed in sections treated with Thy1.2 antibody, at 14 days after the treatment of 100${\mu}g/g$ DMBA. By the electron microscopy phagocytic epithelial cells or macrophages were remarkably increased in spleen at 14and 21days following the treatment of 100${\mu}g/g$ DMBA.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.381-387
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• 1991

Deer hemal nodes were studied by gross anatomy and light microscopy. Hemal nodes were scattered in the periphery of thoracic and abdominal aortae, and spherical or avoid in shape. A hemal node consisted of a thin capsule and a hilum, and had numerous small subcapsular and deep sinuses distended by a great number of erythrocytes. Although a few lymphatic nodules and tissues were seen in the parenchyma, no typical cortex and medulla was defined. Blood vessels occurred, but lymph vessel was not observed in nodes. The parenchyma of the hemal node consisted of many erythrocytes and lymphocytes, and a few granulocytes, plasma cells megakaryocytes and macrophages. The stroma was composed of reticular cells and fibers. The capsule and trabecula was a collagenous connective tissue with smooth myofibers. The above findings suggest that the hemal nodes are involved in blood storage, blood filtration and immune reaction.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.209-216
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• 1991

Acute Megakaryoblastic leukemia is a rare and rapidly fatal disease characterized by proliferation of megakaryocyte series and atypical megakaryocytes in the bone marrow. Acute Megakaryoblastic leukemia is suspicious when 1) megakaryocyte in peripheral blood, mixture of large and small mononuclear megakaryoblast in the bone marrow 2) cytoplasmic budding in blast 3) myelofibrosis (dense medullary overgrowth of reticulin fibers) 4) PAS(+), ANAE(+), SBB(-), peroxidase(-) and which is confirmed by platelet peroxidase oxidation on electromicroscope or monoclonal antibody. A case of aute megakaryoblastic leukemia was studied morphologically and monoclonal antibody.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.229-235
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• 1994

The hemal nodes of the Korean native cattle were studied by gross anatomy and light microscopy. Hemal nodes were spherical or ovoid in shape, and red or black in colors. A hemal node consisted of a thick capsule and a hilum, and had extensive subcapsular and deep sinuses distended by a great number of erythrocytes. Although a few lymphatic nodules and tissues were seen in the parenchyma, no typical cortex and medulla was defined. Blood vessels occurred, but lymph vessel was not observed in nodes. The stroma of the hemal node was composed of reticular cells and fibers. The parenchyma consisted of many erythrocytes and lymphocytes, and a few macrophages and megakaryocytes. The capsule and trabecula was a collagenous connective tissue with smooth muscle cells. B-lymphocytes were principally located in the lymphatic nodules of the hemal node. T-lymphocytes were scattered in the diffuse lymphatic tissues of the hemal node.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.894-900
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• 2005

Purpose : Because of the unavailability of marrow transplantation, umbilical cord blood (CB) is increasingly being used. We evaluated the potential of ex vivo expansion and clonality in CD34+ cells separated from cord blood source and mobilized peripheral blood (PB) in a serum-free media. Methods : The CD34+ cells, selected from CB and mobilized PB, were expanded with hematopoietic growth factors. They were then cultured for burst-forming units of erythrocytes (BFU-E), colony-forming units of granulocytes and monocytes (CFU-GM) and colony-forming units of megakaryocytes (CFU-Mk) at culture days 0, day 4, day 7, and day 14 with various growth factors. Results : The CB-selected CD34+ cells showed significantly higher total cell expansion than those from the PB at day 7 (2 fold increase than PB). The CB-selected CD34+ cells produced more BFU-E colonies than did the PB on culture at days 7 and at day 14. Also, the CB-selected CD34+ cells produced more CFU-Mk colonies than did the PB on culture at day 4 and at day 7. Conclusion : The ex vivo expansion of the CB cells may be promising in producing total cellular expansion, CFU-Mk and BFU-E compared with PB for 7 to 14 days. The growth factors combination including megakaryocyte growth and development, flt3-ligand and interleukin-3 showed more expansion in the view of total cells and clonal maintenance compared with less combination.

• BMB Reports
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• v.48 no.12
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• pp.691-695
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• 2015

We report that phytosphingosine, a sphingolipid found in many organisms and implicated in cellular signaling, promotes megakaryocytic differentiation of myeloid leukemia cells. Specifically, phytosphingosine induced several hallmark changes associated with megakaryopoiesis from K562 and HEL cells including cell cycle arrest, cell size increase and polyploidization. We also confirmed that cell type specific markers of megakaryocytes, CD41a and CD42b are induced by phytosphingosine. Phospholipids with highly similar structures were unable to induce similar changes, indicating that the activity of phytosphingosine is highly specific. Although phytosphingosine is known to activate p38 mitogen-activated protein kinase (MAPK)-mediated apoptosis, the signaling mechanisms involved in megakaryopoiesis appear to be distinct. In sum, we present another model for dissecting molecular details of megakaryocytic differentiation which in large part remains obscure.

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.727-734
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• 1997

Hemolymph nodes of the Korean native cattle were observed gross anatomically and light microscopically in this study. Hemolymph nodes of the Korean native cattle were found mainly at the periphery of the thoracic and abdominal aortae although there were some other parts to observe these small organs. These organs were small in size and spherical or ovoid in shape, and color of them was dark red or gray in common with red band. The hemolymph nodes were surrounded by a relatively thick connective tissue capsules composed of dense collagen fibers with many scattered smooth muscle fibers and there was a hilus in each node. The parenchyma was divided into an outer cortex and an inner medulla. A few primary and secondary lymph nodules were observed in the cortex and there were diffuse lymphatic tissues among them. The medullary cords consisted of diffuse lymphatic tissues were separated by the medullary sinuses which filled with erythrocytes. The afferent and efferent lymph vessels were observed at the periphery of the capsule and the hilus area, respectively. The stroma of the hemolymph nodes was composed of reticular cells and fibers, and the meshwork of the stroma was filled with many lymphocytes and erythrocytes, and a few macrophages and megakaryocytes etc. These findings suggest that the hemolymph node of the Korean native cattle is involved in blood filtration and immune reaction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.1
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• pp.173-177
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• 1994

Multiple myeloma is a malignant plasma cell tumor that is thought to originate proliferation of a single clone of abnormal plasma cell resulting production of a whole monoclonal paraprotein. The authors experienced a case of multiple myeloma with severe mandibular osteolytic lesions in 46-year-old female. As a result of careful analysis of clinical, radiological, histopathological features, and laboratory findings, we diagnosed it as multiple myeloma, and the following results were obtained ; 1. Main clinical symptoms were intermittent dull pain on the mandibular body area, abnormal sensation of lip and pain due to the fracture on the right clavicle. 2. Laboratory findings revealed M-spike, reversed serum albumin-globulin ratio, markedly elevated ESR and hypercalcemia. 3. Radiographically, multiple osteolytic punched-out radiolucencies were evident on the skull, zygoma, jaw bones, ribs, clavicle and upper extremities. Enlarged liver and increased uptakes on the lesional sites in RN scan were also observed. 4. Histopathologically, markedly hypercellular marrow with sheets of plasmoblasts and megakaryocytes were also observed.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.203-207
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• 2008

A 3-year-old spayed female Persian feline with non regenerative anemia showed persistent autoagglutination in EDTA anticoagulated blood. Primary immune-mediated hemolytic anemia (IMHA) was suspected and the underlying causes for IMHA were excluded by radiologic, sonographic, serologic and molecular studies. Cytologic examination of the bone marrow revealed that dysmyelopoiesis and dysplastic changes were prominent in the erythroid cells. These changes included asynchronous maturation of the nucleus and cytoplasm, binucleation, trinucleation, fragmented or lobulated nuclei and multilineages. Mild dysgranulopoiesis and dysmegakaryocytopoiesis were also detected including pseudo Pelger-Huet anomalies, giant band neutrophils, asynchronous maturation of the nucleus and cytoplasm in granulopoiesis and large hypolobulated forms as well as dwarf megakaryocytes in megakaryocytopoiesis. Myelodysplastic syndrome and congenital dysmyelopoiesis was ruled out by the low number of blast cells. Finally, secondary dysmyelopoiesis associated with IMHA was diagnosed and immunosuppressive treatment was successfully responsive.