Biomedical subjects

Y Ebihara

Publications and source records attributed to Y Ebihara.

At least 19 recordsLinked to original sources

PubMed1999

Expression of E2A-HLF chimeric protein induced T-cell apoptosis, B-cell maturation arrest, and development of acute lymphoblastic leukemia.

The E2A-HLF fusion gene, generated by t(17;19)(q22;p13) in acute lymphoblastic leukemia (ALL), encodes a chimeric transcription factor in which the trans-activating domains of E2A are fused to the DNA-binding and dimerization domains of hepatic leukemic factor (HLF). To investigate its biological role, we generated transgenic mice expressing E2A-HLF using Ig enhancer and promoter, which direct transgene expression in cells committed to the lymphoid lineage. The transgenic mice exhibited abnormal development in the thymus and spleen and were susceptible to infection. The thymus contained small numbers of thymocytes, and TUNEL staining showed that higher population of thymocytes were undergoing apoptosis. The spleen exhibited a marked reduction in splenic lymphocytes and the flow cytometric analyses and the in vitro colony formation assays showed that the B-cell maturation was blocked at a very early developmental stage. These findings indicated that the expression of E2A-HLF induced T-cell apoptosis and B-cell maturation arrest in vivo and that the susceptibility of the transgenic mice to infection was due to immunodeficiency. Moreover, several transgenic mice developed acute leukemia, classified as T-ALL based on the surface marker analysis and DNA rearrangements, suggesting that an additional event is required for malignant transformation of lymphoid cells expressing E2A-HLF. Our findings provide insight into the biological function of E2A-HLF in lymphoid development and also its role in leukemogenesis.

Adenovirus E2 Proteins↗

PubMed1999

Soluble interleukin-6 (IL-6) receptor with IL-6 stimulates megakaryopoiesis from human CD34(+) cells through glycoprotein (gp)130 signaling.

We have recently shown that stimulation of glycoprotein (gp) 130, the membrane-anchored signal transducing receptor component of IL-6, by a complex of human soluble interleukin-6 receptor (sIL-6R) and IL-6 (sIL-6R/IL-6), potently stimulates the ex vivo expansion as well as erythropoiesis of human stem/progenitor cells in the presence of stem cell factor (SCF). Here we show that sIL-6R dose-dependently enhanced the generation of megakaryocytes (Mks) (IIbIIIa-positive cells) from human CD34(+) cells in serum-free suspension culture supplemented with IL-6 and SCF. The sIL-6R/IL-6 complex also synergistically acted with IL-3 and thrombopoietin (TPO) on the generation of Mks from CD34(+) cells, whereas the synergy of IL-6 alone with TPO was barely detectable. Accordingly, the addition of sIL-6R to the combination of SCF + IL-6 also supported a substantial number of Mk colonies from CD34(+) cells in serum-free methylcellulose culture, whereas SCF + IL-6 in the absence of sIL-6R rarely induced Mk colonies. The addition of monoclonal antibodies against gp130 to the suspension and clonal cultures completely abrogated the megakaryopoiesis induced by sIL-6R/IL-6 in the presence of SCF, whereas an anti-TPO antibody did not, indicating that the observed megakaryopoiesis by sIL-6R/IL-6 is a response to gp130 signaling and independent of TPO. Furthermore, human CD34(+) cells were subfractionated into two populations of IL-6R-negative (CD34(+) IL-6R-) and IL-6R-positive (CD34(+) IL-6R+) cells by fluorescence-activated cell sorting. The CD34(+) IL-6R- cells produced a number of Mks as well as Mk colonies in cultures supplemented with sIL-6R/IL-6 or TPO in the presence of SCF. In contrast, CD34(+) IL-6R+ cells generated much less Mks and lacked Mk colony forming activity under the same conditions. Collectively, the present results indicate that most of the human Mk progenitors do not express IL-6R, and that sIL-6R confers the responsiveness of human Mk progenitors to IL-6. Together with the presence of functional sIL-6R in human serum and relative unresponsiveness of human Mk progenitors to IL-6 in vitro, current results suggest that the role of IL-6 may be mainly mediated by sIL-6R, and that the gp130 signaling initiated by the sIL-6R/ IL-6 complex is involved in human megakaryopoiesis in vivo.

Antigens, CD↗

PubMed1999

Amyloid deposition in renal angiomyolipoma.

An irregular tumor shadow, seen on the left kidney in a 48-year-old woman by computed tomography, was pathologically diagnosed as 'angiomyolipoma'. HMB-45 immunoreactivity distinguished angiomyolipoma from renal cell carcinoma of sarcomatoid type. The amyloid deposition was limited to the tumor. M-protein and Bence-Jones protein were negative. For amyloid protein characterization, immunohistochemical studies were performed with antiamyloid A, anti-kappa, anti-lambda, anti-prealbumin and anti-beta-2 microglobulin, but none reacted with the amyloid. This is the first documented case of amyloid deposition in angiomyolipoma and may represent a novel precursor protein of amyloid.

Amyloid↗

PubMed1999

A retroperitoneal bronchogenic cyst with malignant change.

A unique case of adenocarcinoma arising in a retroperitoneal bronchogenic cyst is presented. A 55-year-old woman presented with lower abdominal discomfort. Computed tomography revealed a retroperitoneal cystic mass attached to the ascending colon. The resected cyst was unilocular and filled with milky white mucus and hemorrhagic debris. Histologically, most of the cyst wall was of well-differentiated papillary adenocarcinoma with no cyst wall invasion. Other small areas of the cyst were lined with variably atypical dysplastic/metaplastic cuboidal to pseudostratified columnar epithelium. The cyst wall was mostly hyalinized, but there was apparent thickened subepithelial basement membrane, elastosis, and a single layer of smooth muscle that suggested bronchial wall structures. A mucin staining study with O-acylated sialic acid, which is used for the demonstration of gastrointestinal, cholecystic and uterine cervical mucins, was negative for the mucin-producing epithelial cells of the cyst. Thus, to our knowledge, this is the first reported case of adenocarcinoma arising in a retroperitoneal bronchogenic cyst.

Adenocarcinoma↗

PubMed1999

[Hypereosinophilic syndrome complicated by myelofibrosis].

Hypereosinophilic syndrome (HES) with myelofibrosis was diagnosed in a 36-year-old man on the basis of bone marrow biopsy findings and clinical features. Although the patient was treated with steroid (1 mg/kg), hydroxyurea, and immunosuppressive therapy, eosinophilia persisted. Patients with HES and myelofibrosis are usually unresponsive to antineoplastic agents and/or immunosuppressants. However, cyclosporin may be an effective alternative for such patients.

Adult↗

PubMed1999

The relationship between p21/waf1 expression patterns and cell proliferation during the tumorigenesis of the bronchus.

Each developmental stage in the process towards bronchial squamous cell carcinoma (normal epithelium, squamous metaplasia and early stage squamous cell carcinoma including in situ carcinoma) was examined for p21/waf1 protein expression and cell proliferation using MIB1. P21/waf1 immunoreactivity was classified into four patterns: predominantly cytoplasmic staining, exclusively nuclear staining, both nuclear and cytoplasmic staining and negative. The cases with predominantly cytoplasmic staining showed suppression of cell proliferation. Most cases with either negative or exclusively nuclear staining revealed high cell proliferation. The simultaneous evaluation of p21/waf1 and cell proliferation is valuable for clinical determination of the high risk for malignant transformation.

Blotting, Western↗

PubMed1998

A combination of semiquantitative telomerase assay and in-cell telomerase activity measurement using exfoliated urothelial cells for the detection of urothelial neoplasia.

BACKGROUND: Telomerase is a ribonucleoprotein that synthesizes telomeres. It is detected in more than 85% of samples obtained from cancer tissues, including urologic neoplasia. The authors determined telomerase activity semiquantatively and in-cell telomerase activity in exfoliated urothelial cells obtained from urologic neoplasia specimens. The goal of this study was to provide additional information regarding a noninvasive approach to the detection of urologic neoplasia. METHODS: The authors used voided urine from 23 patients with urologic neoplasia, 2 patients with nonmalignant urologic disorders, and 10 normal individuals. Semiquantative determination of telomerase activity was performed using a fluorescence-based telomeric repeat amplification protocol (TRAP), and telomerase activity at the cellular level was determined by an in situ TRAP assay. RESULTS: The fluorescence-based TRAP assay detected urinary telomerase activity in samples from 10 of 13 patients with urologic neoplasia before treatment, whereas urinary cells obtained from 3 of 10 patients (including 1 patient with relapse) during or after treatment had detectable telomerase activity. In contrast, the in situ TRAP assay detected telomerase positive cells in samples from 11 of 13 patients before treatment and 6 of 10 patients during or after treatment. Of note was a dissociation of the results of the fluorescence-based TRAP assay and those of the in situ TRAP assay for some patients. Some patients for whom telomerase activity was not detected with the fluorescence-based TRAP assay had a low frequency of telomerase positive cells in their urine. CONCLUSIONS: A combination of semiquantative analysis and an in situ TRAP assay to detect telomerase positive cells might be a useful tool in the identification and monitoring of patients with urothelial neoplasia.

Adult↗

PubMed1998

Human granulocyte colony-stimulating factor (G-CSF) stimulates the in vitro and in vivo development but not commitment of primitive multipotential progenitors from transgenic mice expressing the human G-CSF receptor.

Granulocyte colony-stimulating factor (G-CSF) stimulates the proliferation and restricted differentiation of hematopoietic progenitors into neutrophils. To clarify the effects of G-CSF on hematopoietic progenitors, we generated transgenic (Tg) mice that had ubiquitous expression of the human G-CSF receptor (hG-CSFR). In clonal cultures of bone marrow and spleen cells obtained from these mice, hG-CSF supported the growth of myelocytic as well as megakaryocytic, mast cell, mixed, and blast cell colonies. Single-cell cultures of lineage-negative (Lin-)c-Kit+Sca-1(+) or Sca-1(-) cells obtained from the Tg mice confirmed the direct effects of hG-CSF on the proliferation and differentiation of various progenitors. hG-CSF also had stimulatory effects on the formation of blast cell colonies in cultures using 5-fluorouracil-resistant hematopoietic progenitors and clone-sorted Lin-c-Kit+Sca-1(+) primitive hematopoietic cells. These colonies contained different progenitors in proportions similar to those obtained when mouse interleukin-3 was used in place of hG-CSF. Administration of hG-CSF to Tg mice led to significant increases in spleen colony-forming and mixed/blast cell colony-forming cells in bone marrow and spleen, but did not alter the proportion of myeloid progenitors in total clonogenic cells. These results show that, when functional G-CSFR is present on the cell surface, hG-CSF stimulates the development of primitive multipotential progenitors both in vitro and in vivo, but does not induce exclusive commitment to the myeloid lineage.

Animals↗

PubMed1998

Stimulation of mouse and human primitive hematopoiesis by murine embryonic aorta-gonad-mesonephros-derived stromal cell lines.

We report here on a novel stromal cell line, AGM-S3, derived from the aorta-gonad-mesonephros (AGM) region of a 10.5 days postcoitum (dpc) mouse embryo. The AGM-S3 cells promoted production of hematopoietic progenitors and day-12 spleen colony-forming cells from Lin-c-Kit+Sca-1(+) murine primitive hematopoietic cells. They also supported for 6 weeks generation of human multipotential progenitors from cord blood CD34(+)CD38(-) primitive hematopoietic cells. Human long-term repopulating hematopoietic stem cells (LTR-HSC) with the potential to reconstitute hematopoiesis in NOD/SCID mice were maintained on AGM-S3 cells for at least 4 weeks. Flow cytometric analysis showed that CD13, vascular cellular adhesion molecule-1, and Sca-1 were expressed on AGM-S3 cells. Because stem cell factor, interleukin-6 (IL-6), and oncostatin M, but not IL-3, IL-11, leukemia- inhibitory factor, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, thrombopoietin, and Flk2 ligand were detected in reverse transcription-polymerase chain reaction analysis of AGM-S3 cells, the cells seem to express species-cross reactive molecule(s) other than the cytokines examined and which act on primitive hematopoietic progenitor/stem cells. This cell line is expected to elucidate molecular mechanisms regulating early hematopoiesis and pave the way for developing strategies for expansion of human transplantable HSC.

ADP-ribosyl Cyclase↗

PubMed1998

Potential role of kallikrein in diurnal rhythms and perivascular distribution in rat pineal glands.

Kallikrein hydrolyzes various biologically active peptides, other than kininogens, such as vasoactive intestinal polypeptide (VIP), in vitro. Since kallikrein and VIP have been immunohistochemically shown to be present in the perivascular areas of the pineal gland, this study was designed to determine their topographic proximity in these glands, using immunohistochemical and immunoelectron microscopic double staining methods. Furthermore, since this gland is well-known to have a circadian rhythm, the kallikrein content was measured every 4 h, using a synthetic substrate, Pro-Phe-Arg-MCA, and an enzyme-linked immunosorbent assay (ELISA) to determine whether kallikrein has a circadian rhythm. The immunoreactivities of kallikrein and VIP were highly localized in the perivascular extracellular spaces and were virtually identical in distribution. The kallikrein content changed every 4 h and was high under light and low under dark conditions. The change was more evident when the synthetic substrate was used, and this rhythm was subtle on ELISA. VIP is also said to have a circadian rhythm in the pineal glands, being low under light and high under dark conditions, i.e., opposite to that of kallikrein. Since kallikrein degrades VIP in vitro, it is reasonable to speculate that pineal gland kallikrein is involved in the processing of VIP and possibly other biologically active peptides in the perivascular areas with a discernible circadian rhythm.

Animals↗

PubMed1998

A combination of stem cell factor and granulocyte colony-stimulating factor enhances the growth of human progenitor B cells supported by murine stromal cell line MS-5.

We have developed a long-term culture system using the murine bone marrow stromal cells MS-5 to support the growth of progenitor B cells with CD34-, CD10+, CD19+, and cytoplasmic mu chain (C mu)-negative surface phenotype from human CD34+ cells purified from umbilical cord blood (CB). When 10(3) CD34+ cells/well were seeded on MS-5 stromal cells at the beginning of culture in the absence of exogenously added cytokines, progenitor B cells first appeared after 14 days, and the maximal cell production was achieved during the 6th week of culture. Intriguingly, the addition of recombinant human stem cell factor (rhSCF) and granulocyte colony-stimulating factor (rhG-CSF), but not rhIL-7, strikingly enhanced the growth of progenitor B cells from CB CD34+ population cultured on MS-5 stromal cells. The culture of progenitor B cells could be maintained until the 6th week of culture when some cells were revealed to have a C mu phenotype, and a small number of cells had immunoglobulin mu chain on their cell surface in the presence of both rhSCF and rhG-CSF. When CD34+ cells were cultured physically separated from the stromal layer by membrane, supportive effects of MS-5 stromal cells for the growth of progenitor B cells were not observed. These results suggest that the present culture system could generate progenitor B cells to proliferate from CB CD34+ cells, that some of these progenitor B cells could differentiate into immature B cells in conjunction with rhSCF and rhG-CSF, and that a species-cross-reactive membrane-bound factor(s), which stimulates early human B lymphopoiesis, may exist in MS-5 stromal cells. Further studies are required to investigate the mechanism how rhG-CSF acts on progenitor B cells to allow their proliferation and differentiation.

Animals↗

PubMed1998

Low concentrations of adenosine receptor blocker decrease protection by hypoxic preconditioning in ischemic rat hearts.

UNLABELLED: A role for adenosine in ischemic preconditioning and hypoxic preconditioning (HP) has been established in several species but is controversial in rats, due in part to the inconsistency of the data from the different experimental design. Our objective was to investigate the role of adenosine in the protection of the ischemic myocardium by HP in rats. METHODS: perfused hearts isolated from Sprague-Dawley rats were exposed to 5 min of hypoxic perfusion before 25 min of global ischemia followed by 20 min of reperfusion. The effects of adenosine receptor antagonist, 8-(p-sulfophenyl)-theophylline (8SPT) on HP-based changes in left-ventricular function, energy metabolites, and release of creatine kinase and lactate dehydrogenase were determined. To minimise non-specific effects of 8SPT, low concentrations of agent (0.5 or 1.0 micro mol/l) were used. RESULTS: 8SPT alone had no deleterious effects on normoxically perfused hearts or on ischemic/reperfused hearts. HP improved the recovery of LV function and creatine phosphate, and reduced the release of enzymes during reperfusion. 8SPT (1.0 micromol/l) ameliorated the beneficial effect of HP on cardiac function, but did not reverse the reduction in release of enzymes by HP completely. CONCLUSION: results suggest that the protective effect of HP on myocardial contractile function may be mediated by receptor(s) that can be inhibited by low concentrations of antagonist but may not have a primary role in the reduction of cellular damage by HP in rats.

Adenosine↗

PubMed1998

Angiography of experimental autoimmune uveoretinitis with ultrastructural correlation.

BACKGROUND: Indocyanine green (ICG) angiography has been used to evaluate posterior uveitis in the clinical setting, despite the shortage of data on possible pathological correlates of observed findings. METHODS: We used both ICG angiography and fluorescein angiography to examine rats that developed a mild form of experimental autoimmune uveoretinitis (EAU) induced by immunization with interphotoreceptor retinoid-binding protein (IRBP). Angiography was performed on days 9, 10, 11 and 23 after IRBP immunization, and freshly enucleated eyes obtained on the same days were examined histopathologically by light microscopy and transmission electron microscopy. RESULTS: Diffuse dilatation and tortuosity of the retinal vessels was observed by both ICG and fluorescein angiography, with leakage from these vessels in focal areas in the periphery. In addition, deep hyperfluorescent spots in the central posterior pole, not associated with retinal vessels, were observed by ICG angiography only. These corresponded to Dalen-Fuchs-like nodules on funduscopy. On histopathological examination, eyes showed inflammatory cell infiltration around retinal vessels, disorganization of outer retinal layers, focal subretinal accumulations of cells (resembling Dalen-Fuchs nodules), and diffuse inflammatory cell infiltration in the choroid. Ultrastructural examination of a Dalen-Fuchs-like nodule revealed a mound of monocytes, appearing to contain phagosomes of lipofuscin and phospholipids, sandwiched between transformed retinal pigment epithelium (RPE) cells with disrupted apical processes and loss of basal interdigitation. CONCLUSION: These results suggest that ICG angiography may be useful in delineating certain abnormalities at the level of the RPE, in association with posterior ocular inflammation, that cannot be observed by fluorescein angiography alone.

Animals↗

PubMed1998

Immunohistochemical, ultrastructural and molecular study of well differentiated adenocarcinomas of the lung predominantly composed of goblet cells.

In order to clarify the morphological and biological characteristics of well differentiated adenocarcinoma of the lung predominantly composed of goblet cells (WDAG), histopathological examinations, including some molecular biological procedures, were carried out using 42 surgical specimens of primary lung carcinoma which were predominantly (>50% of the total cell population) or totally composed of goblet cells. The subjects included 19 men and 21 women, ranging in age from 41 to 81 (mean 60 years old) with predominantly nodular, peripherally located lesions. Ultrastructural examination revealed characteristic apical microvillous filamentous core rootless (AFCR) in some, but not all, cases. Histologically, these AFCR corresponded well with structures stained by phosphotungstic acid hematoxylin (PTAH). The goblet cells of WDAG were divided into PTAH-positive (26 cases) and -negative (16 cases) groups. The PTAH-positive group had larger tumor size, greater number of intrapulmonary and extrapulmonary metastases and shorter disease-free interval. The immunoexpression of p53 protein (60%) and rate of K-ras point mutation (84%) were also higher in the PTAH-positive group. Therefore the goblet cell population of WDAG, though it may appear morphologically homogeneous under light microscopy, is actually composed of heterogeneous groups of cells with different histopathological characteristics and biological behavior.

Adenocarcinoma↗

PubMed1998

Influence of E-cadherin dysfunction upon local invasion and metastasis in non-small cell lung cancer.

E-Cadherin (ECD), a transmembrane cell adhesion molecule, is associated with three kinds of cytoplasmic proteins (alpha-catenin, beta-catenin and plakoglobin), and formation of the cadherin-catenins adhesion complex is indispensable for tight cell-to-cell adhesion in adherence junctions. There is a high possibility that dysfunction of ECD reflects increased potential for local invasion and distant metastasis. We investigated the relationship between the expression of cadherin-catenin adhesion complex and the clinicopathological features in 81 cases of non-small cell lung cancer. There were statistically significant relationships between the expression of ECD and lymph node metastasis (P = 0.016) and between the expression of ECD and pathological stage (P = 0.006). Reduction of alpha-catenin expression was associated with local invasion and pathological stage. Dividing the 81 cases into two groups based on ECD function revealed a statistically significant relationship between ECD function and all clinicopathological factors investigated (local tumor invasion P = 0.033, lymph node metastasis P<0.001, pathological stage P<0.001). Evaluation of ECD function using the expression of cadherin-catenin adhesion complex is useful to evaluate tumor malignancy of non-small cell lung cancer.

Adenocarcinoma↗

PubMed1998

Peripheral non-small cell lung cancers 2.0 cm or less in diameter: proposed criteria for limited pulmonary resection based upon clinicopathological presentation.

Clinical features of peripheral non-small cell lung cancer 2.0 cm or less were retrospectively analyzed. Nodal status and prognosis in relation to tumor diameter and histologic type were investigated in 171 consecutive patients with peripheral clinical T1N0M0 non-small cell lung carcinomas 2 cm or less in diameter and who had undergone surgical resection between 1976 and 1997. Of the 171 patients, 136 had adenocarcinoma, 27 had squamous cell carcinoma, four had large cell carcinoma, three had carcinoid and one had adeno-squamous carcinoma. There was no statistically significant difference in the incidence of stage I cases between adenocarcinoma and squamous cell carcinoma. Lymph node involvement was recognized in 30 (17.5%) patients: ten (5.8%) at N1 nodes and 20 (11.7%) at N2 nodes. Lymph node metastasis was significantly more common in tumors 1.5-2.0 cm in diameter (22%) than in those 1.5 cm or less in diameter (14.0%, P = 0.0490). There was no lymph node metastasis in tumors 1.0 cm or less in diameter. The 5-year survival rates cases with or without lymph node involvement were 63.3 and 75.3%, respectively, showing significant difference (P = 0.0338). The result of the present study suggested that systematic mediastinal and hilar lymph node dissection is necessary even for cases with tumor diameter less than 2 cm. However, if the tumor is within 1.0 cm in diameter, mediastinal lymph node dissection might be dispensable; therefore, these cases are good candidates for video-assisted lobectomy.

Adult↗

PubMed1998

Characterization of leukemic cells in CD2/CD19 double positive acute lymphoblastic leukemia.

In the diagnosis of leukemia, CD2 which is a T-cell associated marker and CD19 which is a B-cell associated marker are widely used to determine the lineage of leukemic cells. It is known that the cells of acute lymphoblastic leukemia (ALL) express both CD2 and CD19 in some cases. The origins of these cells are generally thought to be a common precursor for T- and B-lymphocytes. However, cytoplasmic staining of CD3 which is a more specific marker for T-lineage and cytoplasmic staining of mb-1 (CD79a) which is more specific for B-lineage were not performed in previous reports and the determination of the cell lineages of these cells was unclear. We had two cases of ALL whose blasts were CD2/CD19 double positive. The first case was assessed as B-lineage because the cells expressed cytoplasmic CD79a and lacked cytoplasmic CD3. The immunoglobulin (Ig) heavy chain gene was rearranged. The other cell surface markers including CD22 and HLA-DR also suggested that these cells were B-lineage. The CD2 expression may be a coincidence and should not be taken as a T-cell marker in this case. It was difficult to determine the lineage in the second case because both cytoplasmic CD79a and cytoplasmic CD3 were expressed and neither TCR beta chain nor Ig heavy chain genes were rearranged. The other surface markers were not useful to determine the lineage. We concluded that this case was really an unclassified ALL. Accordingly, cytoplasmic staining of CD3 and CD79a should be carried out in the diagnosis of leukemia when it is difficult to determine the cell lineage.

Adolescent↗

PubMed1998

Alpha-fetoprotein producing pulmonary blastoma in a patient with systemic sclerosis: pathogenetic analysis.

We describe a rare case of pulmonary blastoma complicated with systemic sclerosis. The serum alpha-fetoprotein level was elevated at presentation and the biopsied tumour stained positively against anti-alpha-fetoprotein antibody. The alpha-fetoprotein produced autonomously by tumour cells was of yolk-sac origin. Although the pathogenesis of pulmonary blastoma has not been clarified, we suggest that this pulmonary blastoma is a type of yolk-sac tumour.

Female↗