Biomedical subjects

M Miwa

Publications and source records attributed to M Miwa.

At least 19 recordsLinked to original sources

PubMed2006

Measurement of acoustic output power in a traveling wave engine.

We built and tested a double-loop thermoacoustic cooler consisting of an engine-loop, a branch resonator, and a cooler-loop. The cooling power of 6.4 W was obtained at the cooling temperature of 0 degrees C, when the input heat power of 416 W was supplied to the engine-loop. We measured the acoustic power and found that the output power emitted from the engine-loop was 12 W, and that the input acoustic power entering the cooler-loop was 6 W.

Journal Article↗

PubMed2006

Osteogenic potential of cells in vitro derived from haemarthrosis of the knee induced by injury to the anterior cruciate ligament.

We have investigated whether cells derived from haemarthrosis caused by injury to the anterior cruciate ligament could differentiate into the osteoblast lineage in vitro. Haemarthroses associated with anterior cruciate ligament injuries were aspirated and cultured. After treatment with beta-glycerophosphate, ascorbic acid and dexamethasone or 1,25 (OH)(2)D(3), a significant increase in the activity of alkaline phosphatase was observed. Matrix mineralisation was demonstrated after 28 days and mRNA levels in osteoblast-related genes were enhanced. Our results suggest that the haemarthrosis induced by injury to the anterior cruciate ligament contains osteoprogenitor cells and is a potential alternative source for cell-based treatment in such injury.

Adolescent↗

PubMed2005

MUC 1 core protein as a marker of gallbladder malignancy.

AIM: The significance of MUC 1 expression in the gallbladder tissues in relation to cancer and non-cancer disease is not well understood. The aim of this study was to clarify the significance of MUC 1 expression. MATERIALS AND METHODS: A monoclonal antibody (CA 15--3; DF 3) was applied to stain MUC 1 core protein in surgical specimens. RESULTS: MUC 1 expression is significantly higher (p<0.0001) in gallbladder cancer (69/88) compare to non-cancerous tissue, while, very trace in normal and inflammatory tissues. The expression rate was significantly lower (p<0.0001) when the cancer did not penetrate the mucosal layer than when cancers did penetrate this layer. The MUC 1 expression rate was (4/14) in T1 tumours, (11/14) in T4, (40/45) in T3, and (14/15) in T2, respectively. Every cell of normal and inflammatory mucosa, and T1 cancers had the polarized pattern. The depolarized pattern was dominant in cancer cells from the advanced tumours of T2, T3 and T4. That is, (45/74) of cancer cells from the mucosal layer and (58/74) of penetrating cancer cells in submucosal layer had the depolarized pattern. There was no significant correlation of MUC 1 expression rate and staining pattern with cancer differentiation and microscopic venous invasion. On the other hand, lymphatic vessel invasion was significantly correlated with the staining pattern but not with expression rate. CONCLUSION: MUC 1 core protein expression rate and pattern are suggesting that MUC 1 core protein would be a marker of malignant transformation of gallbladder epithelium and its depolarized expression would also be a marker of invasion of gallbladder cancer.

Adenocarcinoma↗

PubMed2005

Mapping of plumage colour and blood protein loci on the microsatellite linkage map of the Japanese quail.

The objective of this work was to map classical markers (plumage colours and blood proteins) on the microsatellite linkage map of the Japanese quail (Coturnix japonica). The segregation data on two plumage colours and three blood proteins were obtained from 25 three-generation families (193 F2 birds). Linkage analysis was carried out for these five classical markers and 80 microsatellite markers. A total of 15 linkage groups that included the five classical loci and 69 of the 80 microsatellite markers were constructed. Using the BLAST homology search against the chicken genome sequence, three quail linkage groups, QL8, QL10 and QL13, were suggested to be homologous to chicken chromosomes GGA9, GGA20 and GGA24, respectively. Two plumage colour loci, black at hatch (Bh) and yellow (Y), and the three blood protein loci, transferrin (Tf), haemoglobin (Hb-1) and prealbumin-1 (Pa-1), were assigned to CJA01, QL10, QL8, CJA14 and QL13, respectively.

Animals↗

PubMed2004

A tumour vaccine of fixed tumour fragments in a controlled-release vehicle with cytokines for therapy of hepatoma in mice.

BACKGROUND: Cytokines can be strong potentiators for a tumour vaccine, but they have very short life in vivo when administered as a solution. AIMS: To evaluate the slow release of interleukin 2 from a cytokine-vehicle in vitro and in vivo and to evaluate the anti-tumour activity of a new tumour vaccine in vivo. METHODS: The tumour vaccine was composed of formalin-fixed Hepa 1-6 hepatoma tissue fragments, tuberculin and a lipid based vehicle containing granulocyte-macrophage colony-stimulating factor and interleukin 2. The quantity of interleukin 2 release from the cytokine-vehicle in vitro and in vivo was determined by a proliferation assay with CTLL-2 cell line. Hepa 1-6 hepatoma model system with C57BL/6J mice was used to examine protective and therapeutic anti-tumour effect of the vaccine. RESULTS: Release of interleukin 2 from the cytokine-vehicle lasted 5 days in vitro and 3 days in vivo. The vaccine protected 67% of mice from a Hepa 1-6 cell challenge and had a therapeutic effect by prolonging the life span of mice bearing established Hepa 1-6 tumours of 5 mm in diameter. Of the treated mice, 20% became completely tumour-free. CONCLUSIONS: Formalin-fixed tumour fragments and cytokines in controlled-release vehicle are useful in the rational design of tumour vaccines.

Animals↗

PubMed2004

Increased cell proliferation of mouse fibroblast NIH-3T3 in vitro induced by excretory/secretory product(s) from Opisthorchis viverrini.

Infection by Opisthorchis viverrini is a strong risk factor for cholangiocarcinoma. However, the mechanism by which the parasite is involved in carcinogenesis is not clear. In addition to the direct damage of the bile duct epithelium via direct contact with O. viverrini, the excretory/secretory (ES) product(s) released from the parasites may play important roles in this process. We therefore investigated the responses of a fibroblast cell line, NIH-3T3, to ES product(s) released from O. viverrini by using a non-contact co-culture technique. In this culture system, the parasites in the upper chamber had no direct contact with the NIH-3T3 cells in the lower chamber of the culture plate. The results indicated a marked increase in NIH-3T3 cell proliferation in the non-contact co-culture condition with either 0% or 10% calf serum in the medium compared with that without parasites. ES product(s) increased cell proliferation by stimulating the expression of phosphorylated retinoblastoma (pRB) and cyclin D1, the key proteins in driving cells through the G1/S transition point of the cell cycle. This led to the induction of cells going into the S-phase of the cell cycle. ES product(s) also changed the morphology of NIH-3T3 cells to a refractive and narrow shape, which allowed the cells to proliferate in the limited culture area. For the first time, we have been able to demonstrate increased cell proliferation induced by the ES product(s) from O. viverrini; this finding may clarify how O. viverrini ES product(s) affect human bile duct epithelium during cholangiocarcinogenesis.

Animals↗

PubMed2004

A first-generation microsatellite linkage map of the Japanese quail.

A linkage map of the Japanese quail (Coturnix japonica) genome was constructed based upon segregation analysis of 72 microsatellite loci in 433 F(2) progeny of 10 half-sib families obtained from a cross between two quail lines of different genetic origins. One line was selected for long duration of tonic immobility, a behavioural trait related to fearfulness, while the other was selected based on early egg production. Fifty-eight of the markers were resolved into 12 autosomal linkage groups and a Z chromosome-specific linkage group, while the remaining 14 markers were unlinked. The linkage groups range from 8 cM (two markers) to 206 cM (16 markers) and cover a total map distance of 576 cM with an average spacing of 10 cM between loci. Through comparative mapping with chicken (Gallus gallus) using orthologous markers, we were able to assign linkage groups CJA01, CJA02, CJA05, CJA06, CJA14 and CJA27 to chromosomes. This map, which is the first in quail based solely on microsatellites, is a major step towards the development of a quality molecular genetic map for this valuable species. It will provide an important framework for further genetic mapping and the identification of quantitative trait loci controlling egg production and fear-related behavioural traits in quail.

Animals↗

PubMed2001

Genetic and functional analysis of PARP, a DNA strand break-binding enzyme.

Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme activated by binding to a single- or double-strand break of DNA and is one of the death substrates for caspase-3 in apoptosis. The nuclear function of PARP is well studied and recent PARP-knockout studies indicate that PARP takes part in chromosomal stability. To analyze the effect of PARP overexpression, or loss of function, we have cloned PARP cDNA and the gene from Drosophila melanogaster and studied its function in developmental stages. Organization of exons corresponds to the functional domains of PARP. An alternatively spliced form of PARP lacking exon 5, which encodes the auto-modification domain, is found in Drosophila. Expression of the PARP gene is at high levels in embryos at 0-6h after egg laying and gradually decreased. In situ mRNA hybridization indicates localization of PARP mRNA in cells along the central nervous system at a late stage of embryogenesis. Overexpression of the gene in the developing eye primordia of D. melanogaster is an excellent experimental model to analyze the cell cycle and programmed cell death. We introduced PARP expression vector overexpresses PARP in the eye discs of Drosophila, and established the PARP transgenic flies by P element-mediated germ line transformation. These flies showed mild roughening of the normally smooth ommatidial lattice involving tissue polarity disruption characterized by missrotation and incorrect chirality of ommatidia. Possible mechanisms of involvement of PARP in the development are discussed.

Animals↗

PubMed2001

Cerebrovascular damage in young rabbits after intravenous administration of Shiga toxin 2.

Acute encephalopathy associated with Shiga toxin-producing Escherichia coli (STEC) primarily affects children. To elucidate the age-dependent vulnerability of the central nervous system (CNS), we injected Shiga toxin 2 (Stx2) intravenously to young rabbits and examined the clinical and pathological effects on the CNS. Although neurological disorders caused by Stx2 were similar between young and adult rabbits, the dose required to produce them in the young was one third of that required for the adults. Vascular lesions appeared as early as 24 h after injection in the young, but not at all in the adult. Arteriolar changes, such as hydropic swelling of the endothelial cells and karyorrhexis of the medial cells, were specific to the CNS of young animals. Evidence for apoptosis of vascular cells was scarce because DNA strand breaks and activation of caspases-3 and -9 were absent in the vast majority. Given our results, we conclude that the cerebral blood vessels of immature brains are more vulnerable to Stx2 than those of adults in the rabbit.

Acute Disease↗

PubMed2001

Health-related quality of life among dialysis patients in Seattle and Aichi.

We used the 36-item Short-Form Health Survey to compare health-related quality of life (HRQOL) between 104 dialysis patients in Seattle, WA, and 2,178 patients in Aichi, JAPAN: Compared with Aichi patients, Seattle patients had lower scores on three scales related to physical HRQOL: Physical Functioning (PF; P = 0.03), Role-Physical (RP; P = 0.004), and Vitality (VT; P < 0.001). However, scores related to mental HRQOL were higher for Seattle patients compared with those of Aichi patients, which included scores for Role-Emotional (RE; P = 0.005) and Mental Health (MH; P < 0.001). Scores for Bodily Pain, General Health Perception, and Social Functioning did not differ significantly between the two groups. These differences persisted even after potential confounding factors were controlled for. However, after taking into account national norm data for the United States and Japan, differences in PF and VT disappeared, whereas differences in RP, RE, and MH persisted. These results suggest that the higher scores for PF and VT in Aichi patients were partly explained by the higher physical HRQOL of the Japanese general population. Although these data may not be representative of the total dialysis populations in the United States and Japan, they suggest potential differences in HRQOL between patients in the two countries. Additional research is needed to confirm these results and understand the factors associated with these differences. The findings suggest the need for further attention to the physical limitations of US dialysis patients and the mental health of Japanese dialysis patients.

Adult↗

PubMed2001

Outcrossing and paternity analysis of Pinus densiflora (Japanese red pine) by microsatellite polymorphism.

This study employed microsatellite loci to analyse outcrossing rate and pollen dispersal in Japanese red pine (Pinus densiflora) in an isolated stand. The average offspring outcrossing rate for 29 cones was 0.955. Significant differences in outcrossing rates between offspring groups on individual branches that extended in different directions at different heights were not detected. Male parents of 874 offspring collected from the maternal tree were assessed by exclusion using polymorphisms at three microsatellite loci. Paternity analysis indicated that at least 31% of the offspring were fertilized by pollen from trees outside the stand. The average distance of pollen migration within the study stand was 68 m, with a maximum value of 325 m. There was excess mating with nearby P. densiflora trees, of which only a few were predominant pollen donors. In addition, a weakly directional bias in P. densiflora pollination was also detected in the study stand, suggesting that female strobili on a branch of the maternal tree were more easily fertilized by pollen from trees in that direction.

Alleles↗

PubMed2001

Serum factors attenuating the anti-tumor activity of 5-fluorouracil.

In sera of cachectic patients bearing advanced cancers, the concentration of interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrotizing factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) have been reported to elevate. In this study, we investigated whether those cytokines influenced in vitro anti-tumor effect of 5-fluorouracil (5-FU) on a human colon tumor cell line, HCT-15. Pretreatment of HCT-15 cells with IL-1 beta, IL-6 or TNF-alpha did not affect the anti-tumor effect of 5-FU at various concentrations. However, IFN-gamma attenuated the anti-tumor effect of 5-FU at the concentrations of 0.1-10 IU/ml. An experiment with tritium thymidine showed that 0.1 IU/ml of IFN-gamma did not suppress the growth of HCT-15 cells. As low as 0.1 IU/ml of IFN-gamma attenuated the anti-tumor effect of 5-FU in another experimental system where HCT-15 cells were exposed to 0.1 IU/ml of IFN-gamma before and during the treatment with 5-FU. This system mimicked the clinical condition around in situ cancer cells. Treatment of HCT-15 cells with 0.1-10 IU/ml of IFN-gamma did not change their DNA histogram pattern. An immunoblotting with the antibodies to thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in HCT-15 cells revealed that 0.1-10 IU/ml of IFN-gamma enhanced their TS and DPD expressions. Results of the immunoblotting gave some explanation to attenuation in the sensitivity of HCT-15 cells to 5-FU.

Antimetabolites, Antineoplastic↗

PubMed2001

Cell-free entry of human T-cell leukemia virus type 1 to mouse cells.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia and HTLV-1-associated myelopathy / tropical spastic paraparesis. Recently we infected newborn mice by inoculating HTLV-1-producing human cells, and found that T-cells, B-cells and granulocytes were infected in vivo. To understand the mechanism of viral-cell interaction and the pathogenesis of HTLV-1 using the mouse model, it is important to clarify the cellular tropism using a cell-free HTLV-1 transmission system. We employed a highly transmissible cell-free HTLV-1 produced by a feline kidney cell line, c77, and studied the susceptibility of 9 kinds of mouse cell lines, EL4, RLm1, CTLL-2, J774.1, DA-1, Ba / F3, WEHI-3, NIH3T3 and B1, and two kinds of human cell lines, Molt-4 and Hut78. HTLV-1 proviral sequence was found by PCR in all 9 mouse cell lines as well as in 2 human cell lines and viral entry was blocked with sera from an HTLV-1 carrier and an adult T-cell leukemia patient. Unexpectedly, mouse cell lines EL4 and RLm1 and human cell lines Molt-4 and Hut78 showed similar efficiency for viral entry. These results suggest a wide distribution of HTLV-1 receptor in mouse cells.

3T3 Cells↗

PubMed2001

Human T-cell leukemia virus type 1 (HTLV-1) infection of mice: proliferation of cell clones with integrated HTLV-1 provirus in lymphoid organs.

Human T-cell leukemia virus type 1 (HTLV-1) is suggested to cause adult T-cell leukemia after 40 to 50 years of latency in a small percentage of carriers. However, little is known about the pathophysiology of the latent period and the reservoir organs where polyclonal proliferation of cells harboring integrated provirus occurs. The availability of animal models would be useful to analyze the latent period of HTLV-1 infection. At 18 months after HTLV-1 infection of C3H/HeJ mice inoculated with the MT-2 cell line, which is an HTLV-1-producing human T-cell line, HTLV-1 provirus was detected in spleen DNA from eight of nine mice. No more than around 100 proviruses were found per 10(5) spleen cells. Cellular sequences flanking the 3' long terminal repeat (LTR) and the clonalities of the cells which harbor integrated HTLV-1 provirus were analyzed by linker-mediated PCR. The results showed that the flanking sequences are of mouse genome origin and that polyclonal proliferation of the spleen cells harboring integrated HTLV-1 provirus had occurred in three mice. A sequence flanking the 5' LTR was isolated from one of the mice and revealed the presence of a 6-nucleotide duplication of cellular sequences, consistent with typical retroviral integration. Moreover, PCR was performed on DNA from infected tissues, with LTR primers and primers derived from seven novel flanking sequences of the three mice. Data revealed that the expected PCR products were found from lymphatic tissues of the same mouse, suggesting that the lymphatic tissues were the reservoir organs for the infected and proliferating cell clones. The mouse model described here should be useful for analysis of the carrier state of HTLV-1 infection in humans.

Animals↗

PubMed2001

CD31 expression on leukocytes is downregulated in vivo during hemodialysis.

BACKGROUND/AIM: CD31 on leukocytes is the adhesion molecule involved in the leukocyte extravasation in inflammatory conditions. During hemodialysis with cellulosic membranes, it is considered that activated leukocytes adhere to endothelium, but do not show extravasation. However, it is not elucidated why activated leukocytes do not show endothelial transmigration during hemodialysis with cellulosic membranes. METHODS: In the present study, changes in the expressions of Mac-1 and CD31 on granulocytes and monocytes were analyzed by flow cytometry during hemodialysis in 7 patients treated with regenerated-cellulose (RC) membranes and next with polysulfone (PS) membranes. RESULTS: During dialysis with RC, Mac-1 expressions on granulocytes and monocytes both significantly increased as compared with predialysis values and across the dialyzer. During dialysis with RC, the CD31 expression on granulocytes and monocytes significantly decreased as compared with predialysis values. During dialysis with PS, changes in Mac-1 and CD31 expressions on granulocytes and monocytes were smaller than those during dialysis with RC. CONCLUSIONS: Decreased CD31 expression on leukocytes may affect leukocyte function more in patients chronically hemodialyzed with RC than in those hemodialyzed with PS, since CD31 is important in leukocyte transendothelial migration in inflammatory conditions.

Adult↗

PubMed2001

Sustained hyperglycemia and insulin resistance induced by dietary restriction.

This investigation considered whether defects in insulin secretion and insulin action may result in the development of sustained hyperglycemia induced by refeeding standard chow pellets. Hyperglycemia, sustained for 36 h was induced, in mice that ate standard chow pellets ad libitum after 48 h fasting, but not 24 h fasting. In 48 h-fasted mice, serum insulin levels were remarkably low and the ability of insulin secretion to respond to glucose was decreased, although insulin-stimulated glucose disposal was not impaired. However, hyperinsulinemia was observed after refeeding for 12 h. The 12 h-refed mice had impaired glucose tolerance and were remarkably insulin resistant. These results suggest that hyperglycemia induced by the fasting-refeeding was caused by hyperphagia and the failure of insulin secretion, and maintained the resulting induced insulin resistance.

Animals↗

PubMed2001

Cloning, sequencing, and expression of the gene encoding 4-hydroxy-4-methyl-2-oxoglutarate aldolase from Pseudomonas ochraceae NGJ1.

A DNA fragment that carried the gene (proA) encoding 4-hydroxy-4-methyl-2-oxoglutarate aldolase was cloned from the chromosomal DNA of Pseudomonas ochraceae NGJ1, and the coding region was assigned to the nucleotide sequence based on the N-terminal amino acid sequence of the enzyme purified from the organism. The proA gene was 684 bp long, corresponding to a protein of 227 amino acid residues with a calculated molecular mass of 24,067 Da. The genes encoding a putative transporter and a 4-oxalomesaconate hydratase were upstream, and a 3'-truncated gene encoding 2-pyrone-4,6-dicarboxylate lactonase was downstream from the proA gene in the same orientation on the DNA fragment. The proA gene product was overproduced in Escherichia coli and briefly purified to homogeneity from the crude extract by a two-step purification. The molecular and catalytic properties of the gene product were similar to those of the P. ochraceae enzyme.

Amino Acid Sequence↗

PubMed2001

p38 mitogen-activated protein (MAP) kinase but not p44/p42 MAP kinase is involved in prostaglandin E1-induced vascular endothelial growth factor synthesis in osteoblasts.

We investigated the mechanism underlying vascular endothelial growth factor (VEGF) synthesis stimulated by prostaglandin E1 (PGE1) in osteoblast-like MC3T3-E1 cells. PGE1 induced the phosphorylation of both p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase. SB203580, a specific inhibitor of p38 MAP kinase, inhibited the PGE1-stimulated VEGF synthesis as well as PGE1-induced phosphorylation of p38 MAP kinase. PD98059, an inhibitor of the upstream kinase that activates p44/p42 MAP kinase, which reduced the PGE1-induced phosphorylation of p44/p42 MAP kinase, had little effect on the VEGF synthesis stimulated by PGE1. AH-6809, an antagonist of the subtypes of the PGE receptor, EP1 and EP2, or SC-19220, an antagonist of EP1 receptor, did not inhibit the PGE1-induced VEGF synthesis. H-89, an inhibitor of cAMP-dependent protein kinase, and SQ22536, an inhibitor of adenylate cyclase, reduced the VEGF synthesis induced by PGE1. Cholera toxin, an activator of G(s), and forskolin, an activator of adenylate cyclase, induced VEGF synthesis. SB203580 and PD169316, another specific inhibitor of p38 MAP kinase, reduced the cholera toxin-, forskolin- or 8bromo-cAMP-stimulated VEGF synthesis. However, PD98059 failed to affect the VEGF synthesis stimulated by cholera toxin, forskolin or 8-bromoadenosine-3',5'-cyclic monophosphate (8bromo-cAMP). SB203580 reduced the phosphorylation of p38 MAP kinase induced by forskolin or 8bromo-cAMP. These results strongly suggest that p44/p42 MAP kinase activation is not involved in the PGE1-stimulated VEGF synthesis in osteoblasts but that p38 MAP kinase activation is involved.

Alprostadil↗