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Biomedical subjects

K Tsuji

Publications and source records attributed to K Tsuji.

At least 181 records · Page 10Linked to original sources
PubMed1998

Induction of the erythropoietin receptor gene and acquisition of responsiveness to erythropoietin by stem cell factor in HML/SE, a human leukemic cell line.

HML/SE is a cytokine-dependent cell line established from childhood acute megakaryoblastic leukemia. Granulocyte-macrophage colony-stimulating factor or stem cell factor (SCF) alone could stimulate proliferation of HML/SE cells, however interleukin-3, interleukin-6, granulocyte colony-stimulating factor and thrombopoietin could not. Although erythropoietin (EPO) alone stimulated neither proliferation nor differentiation of HML/SE cells, it did stimulate proliferation of HML/SE cells and production of hemoglobin in the presence of SCF. SCF activated the human EPO receptor promoter and induced EPO receptor gene expression. Given these results, we speculate that HML/SE cells acquired responsiveness to EPO via the EPO receptor induced by SCF. Mutation analysis of putative transcription factor binding sites in the human EPO receptor promoter suggested that Sp1, rather than the GATA-1 binding site, contributed to the induction of the hEPOR gene. Although it is well documented that hematopoietic stem cells and primitive progenitors require both an early-acting cytokine and a lineage-specific cytokine to differentiate to a certain lineage, related mechanisms are not well understood. HML/SE may serve as an excellent model system to analyze functions of early-acting cytokine SCF and lineage-specific cytokine EPO related to proliferation and differentiation of hematopoietic stem cells.

Antigens, Surface↗
PubMed1998

A potential molecular approach to ex vivo hematopoietic expansion with recombinant epidermal growth factor receptor-expressing adenovirus vector.

Ex vivo expansion of hematopoietic stem cell (HSC) is an attractive technology for its potency of a variety of clinical applications. Such a technology has been achieved to some extent with combinations of various cytokines or continuous perfusion cultures. However, much more improvement is required especially for expansion of primitive hematopoietic progenitors. We propose here a novel molecular approach that might have the potential to compensate the current expansion. We designed an adenovirus vector to transiently express human epidermal growth factor receptor (EGFR), which is known to transduce only a mitogenic, but not a differentiation signal to mouse bone marrow cells on human purified CD34+ peripheral blood (PB) cells, and tried to expand these cells with EGF ex vivo. Because we found that exposure of CD34+ PB cells to cytokines induced surface expression of adenovirus-internalization receptor and rendered these cells permissive to adenovirus infection, we infected these cells with the adenovirus vector carrying EGFR gene in the presence of cytokines. Two-color flow cytometric analysis demonstrated that 60.3% +/- 22.4% of CD34+ cells expressed the adenovirus-mediated EGFR. Moreover, long-term culture-initiating cell assay showed that adenovirus vector could transduce more primitive progenitors. Subsequently, we tried to expand these cells in suspension culture with EGF for 5 days. Methylcellulose clonal assay showed that EGF induced 5.0- +/- 2.4-fold proliferation of the colony-forming unit pool during 5 days of expansion. The simple procedure of efficient adenovirus gene delivery to immature hematopoietic cells proved promising, and this technique was potentially applicable for a novel strategy aiming at ex vivo expansion of hematopoietic progenitors.

Adenoviridae↗
PubMed1998

Density measurements of liquid under high pressure and high temperature.

A new method for density measurements by means of X-ray absorption under high pressure and high temperature using synchrotron radiation has been developed. The method has been modified for a large-volume Paris-Edinburgh press and combined with intense high-energy X-rays at the ESRF. In order to overcome effects of deformation of sample shape under pressure, a ruby cylinder was used as a sample container. The density was determined from the intensity profile of transmitted X-rays. The densities of crystalline and liquid Bi were successfully measured up to 750 K at 1 GPa.

Journal Article↗
PubMed1998

Cystic fibrosis transmembrane conductance regulator mediates sulphonylurea block of the inwardly rectifying K+ channel Kir6.1.

1. Recombinant ATP-sensitive K+ channels (KATP channels) were heterologously expressed in the NIH3T3 mouse cell line, and the electrophysiological properties were studied using patch-clamp techniques. 2. The NIH3T3 cell lines transfected with the inwardly rectifying K+ channel Kir6.1 alone or with both Kir6.1 and cystic fibrosis transmembrane conductance regulator (CFTR) exhibited time-independent K+ currents with weak inward rectification. In contrast, no measurable K+ conductance was observed in mock-transfected cells or in cells transfected with CFTR alone. Regardless of co-transfection with Kir6.1, the transfection with CFTR produced a Cl- conductance that was activated by cell dialysis with cAMP (1 mM). The conductance was reversibly suppressed by glibenclamide (30 microM). 3. Whole-cell currents at +60 mV were blocked in a concentration-dependent manner by Ba2+ ions with similar IC50 values: 89.3 +/- 23.3 microM (Kir6.1 alone) and 67.3 +/- 24.9 microM (Kir6.1-CFTR). 4. The currents recorded from Kir6. 1-transfected cells were not affected by glibenclamide, whereas glibenclamide did inhibit the conductance expressed in cells co-transfected with CFTR (IC50 = 35.9 +/- 6.6 microM). 5. In the cell-attached mode with a 150 mM K+ pipette solution, both Kir6.1- and Kir6.1-CFTR-transfected cells displayed a class of K+ channels showing weak inward rectification and a slope conductance of 50.7 +/- 1.0 and 52.4 +/- 4.9 pS, respectively. 6. In the inside-out mode, the single-channel currents recorded from both types of cells were not inhibited by intracellular ATP (1 mM). However, glibenclamide was found to block the single-channel activities in the co-transfected cells.

3T3 Cells↗
PubMed1998

Effects of accelerated carbon-ions on growth inhibition of transplantable human esophageal cancer in nude mice.

We have studied the effectiveness of 290 MeV/u carbon-ion (C-) beams (linear energy transfer (LET) of 70 keV/mm) and 200 kVp X-rays on tumor growth inhibition as an in vivo model for radiotherapy of cancer. We measured the size of tumor growth of transplantable human esophageal cancer in nude mice after radiation with C-beams and compared this with X-rays as the control. A significant inhibition of tumor growth was observed by C-beams as compared with X-rays. The relative biological effectiveness (RBE) of C-beams against X-rays was 2.02. Histopathological studies showed that C-beams at 20 Gy induced prominent necrosis in the central region and multinucleate giant cells and inflammatory cells in peripheral regions of the tumor, whereas X-rays at 20 Gy induced only mild necrosis. The high RBE of C-beams obtained in this study provides in vivo evidence that C-beams are more effective than conventional X-rays for radiotherapy of cancer.

Aged↗
PubMed1998

Discovery of FR115092: a novel antinephritic agent.

A series of dapsone-related 4-aminopheynl and 2-aminothiazolyl derivatives was prepared, and their antinephritic activity and blood toxicity were evaluated. 5-(2-Pyridylsulfonyl)-2-thiazolamine (FR115092, 26) was effective against two nephritis models, namely graft-versus-host disease (GVHD) and autoimmune W/BF1 mice, and showed none of the blood toxicity observed with dapsone.

Anemia↗
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

Flow cytometric single-cell analysis of cytokine production by CD4+ T cells in synovial tissue and peripheral blood from patients with rheumatoid arthritis.

OBJECTIVE: To determine the cytokine profile of CD4+ T cells in the synovial tissue (ST) of rheumatoid arthritis (RA) patients at the single-cell level. METHODS: Unseparated ST cells and paired CD4+ T cells separated from the peripheral blood (PB) and ST of RA patients were stimulated for 4 hours with phorbol myristate acetate (PMA) plus calcium ionophore A23187, or for 6 hours with immobilized anti-CD3 plus anti-CD28, in the presence of brefeldin A. Cells were stained for intracellular cytokines such as interferon-gamma (IFNgamma), interleukin-2 (IL-2), IL-4, IL-10, and IL-13, in combination with cell surface markers. The percentages of cytokine-producing T cells were analyzed by flow cytometry. RESULTS: When ST cells were stimulated with PMA plus A23187 in bulk culture, IFNgamma-producing T cells were more frequently detected in the CD8+ subset, but cells producing other cytokines were found in the CD4+ subset. Purified ST CD4+ T cells, after stimulation with PMA plus A23187, were able to produce higher levels of IFNgamma but lower levels of IL-4 and IL-13, by analysis at the single-cell level, as compared with the PB CD4+, CD45RO+ T cells. The majority of IL-4- or IL-13-producing ST CD4+ cells produced IFNgamma, although PB CD4+ T cells rarely showed this cytokine pattern. IL-10-producing CD4+ T cells were more frequently found in the ST than in the PB. Of interest, most of the IL-10-producing ST CD4+ T cells were able to produce IFNgamma. IL-2-producing CD4+ T cells were similarly present in both compartments. Similar intracellular cytokine patterns were observed with anti-CD3 plus anti-CD28 stimulation, although the number of detected cells was lower. CONCLUSION: These data indicate that CD4+ T cells present within the inflamed synovium have apparently distinct cytokine profiles from those of memory CD4+ T cells in the PB, as typified by their ability to secrete both IFNgamma and IL-10.

Aged↗
PubMed1998

Expression of clara cell 10-kDa protein (CC10) in congenital diaphragmatic hernia.

Clara cell 10 kDa protein (CC10) has been thought to be fairly specific to Clara cells and a major secretory protein that is both synthesized and released from Clara cells. In the present study, morphometric analyses of the immunohistochemical expression of CC10 were carried out on the bronchioles of human neonates with congenital diaphragmatic hernia (CDH) and then compared with morphometric analyses from a gestationally and postnatally age-matched control group in order to clarify the immaturity of Clara cells in CDH lungs. No difference was found in CC10 expression between the affected side and the unaffected side of the lungs in the CDH group. However, compared with the lungs of the control group, the CDH group showed a significant decrease in CC10 expression, namely, the ratio of CC10-positive cells per bronchiole, per unit perimeter of bronchiole, and per unit bronchiolar surface area. These results suggest that in the lungs of CDH cases, a possible delay in either functional maturation or the development of CC10 synthesis by the bronchioles may exist, and this retardation of functional maturation of the airway is also considered to play a role in the postnatal respiratory insufficiency observed in CDH patients.

Bronchi↗
PubMed1998

Influence of biliary obstruction on neutrophil chemotaxis.

The effect of obstructive jaundice on neutrophil chemotactic function was investigated, with a potent chemotactic factor, IL-8 (recombinant rat GRO-beta), in rats that received 7-day bile duct ligation. Carrageenin or IL-8 was injected into a preformed air pouch, and exudate was collected 4 h later for measurement of myeloperoxidase activity. In vitro chemotaxis of peripheral neutrophils to IL-8 was evaluated by a modified Boyden chamber method. Both carrageenin and IL-8 induced significantly pronounced intra-air pouch neutrophil recruitment in the bile duct-ligated group compared with a sham-ligated group. In vitro neutrophil chemotaxis was significantly increased in the bile duct-ligated group compared with the sham-ligated group. The present experimental model suggests enhanced neutrophil chemotaxis to IL-8 in obstructive jaundice.

Animals↗
PubMed1998

Nucleotide sequence of the gene encoding the RNA polymerase and the 3' non-coding region of a bovine enterovirus Japanese isolate: rapid synonymous substitutions between European and Japanese strains.

The nucleotide sequences of the genome RNA encoding the RNA polymerase and the 3' non-coding region (NCR) of bovine enterovirus (BEV) serotype I Japanese isolate, MZ468, were determined. The genetic distance between the two BEV serotype I strains, MZ468 and VG-5-27, was calculated by pairwise comparison of nucleotide sequences. The synonymous substitution rate was high (1.40 x 10(-2)/site/year), and of the same order as those of influenza virus HA, HIV-1 gag and env, and enterovirus 70 VP1 genes.

Amino Acid Sequence↗
PubMed1998

Presence of HSV-1 DNA in semen and menstrual blood.

Using a specifically designed diagnostic PCR assay with nested primers the following could be achieved: (1) a group of 22 clinically indistinguishable women attending an infertility clinic, 18 with repeated embryo transfer failure, and asymptomatic for HSV-1 could be divided into two subgroups after testing their menstrual blood. An HSV-DNA positive (50%) and HSV-DNA negative group (50%) could be distinguished. None of the four controls were positive; (2) semen from 154 infertile and 24 fertile men was tested in relation to infertility. In the group of infertile men 37 (24%) were HSV-DNA positive but none of the fertile control (0%) was positive; (3) treatment of both partners with an antiviral drug resulted in two pregnancies; (4) HLA data on four of the couples in which the wife's menstrual blood was HSV positive was compared to seven HSV negative couples and 22 infertile, as well as 22 fertile couples. Clustering of class I HLA (B61 and Cw3) was found with a significant increase in Cw3 in both partners.

Adult↗
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

HLA-A*24-B*07-DRB1*01 haplotype implicated with genetic disposition of peak bone mass in healthy young Japanese women.

HLA exhibits the most extensive polymorphism of any of the known human genes and is known as a genetic marker which allows genetic background of many diseases and physical phenomena. In this study, we, therefore, tried to investigate the regulation of HLA polymorphism and peak bone mass (PBM) in order to elucidate the genetic backgrounds of bone metabolism in young women. Subjects were 67 healthy young Japanese women (average age: 23.6 +/- 2.6 years, Body Mass Index (BMI): 19.9 +/- 2.0 who were randomly chosen. Allelic polymorphisms in HLA class I (HLA-A and -B) and HLA-class II (DRB1) were investigated by PCR-SSOP and PCR-SSP. Vitamin D Receptor (VDR) and Estrogen Receptor (ER) gene polymorphisms were also analyzed. Lifestyle factors, such as exercise and nutrition, were examined by questionnaire. Bone mineral density was examined using with Lunar DPX-L. Subjects who possessed HLA-B*07 had a significantly lower PBM than those without B*07 (p < 0.05). All subjects were divided into 3 groups according to HLA haplotypes linked with HLA-B*07, as follows: A*24(+/-)B*07(-)DRB1*01(+/-), A*24(+)B*07(+)DRB1*01(-), and A*24(+)B*07(+)DRB*01(+). There were no significant differences between these three groups in factors that affect bone metabolism, such as age, age at menarche, BMI, calcium intake, exercise habits, VDR or ER allele frequency. The HLA-A*24-B*07-DRB1*01 haplotype had a significantly lower Z score in the lumbar spine compared with subjects without this haplotype (p < 0.05). When the Z score was divided by values higher or lower than +1 or -1, all 3 subjects whose Z score was lower than -1.0 were found to have the HLA-A*24-B*07-DRB1*01 haptotype. A significant association between HLA-A*24-B*07-DRB1*01 and Z score < -1 was found (Yate's correction chi(2) = 10.82, p = 0.001, RR = 204). In conclusion, the HLA-A*24-B*07-DRB*01 haplotype can be considered a new genetic marker implicated with low PBM in healthy young Japanese women.

Adult↗