A case of primary gastric Burkitt-like lymphoma in the early stage diagnosed by endoscopic mucosal resection.
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Biomedical subjects
Publications and source records attributed to F Takahashi.
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Absorbed dose to tooth enamel was examined against external photon exposure by measurements with thermoluminescence dosemeters (TLDs) and Monte Carlo calculations. TLDs were placed in a realistic physical phantom to measure dose to the teeth region in a head. A voxel-type phantom was constructed from computed tomography (CT) images of the physical phantom. Monte Carlo calculations with this voxel-type phantom were performed to analyse the results of the experiments. The data obtained were compared to the enamel doses, which were calculated with a modified MIRD-type phantom and already given in a previous paper. It was confirmed that the data derived with the MIRD-type phantom are applicable for retrospective individual dose assessments by electron spin resonance (ESR) dosimetry using teeth for the photon energy region above 300 keV. The analysis, however, indicated that the configuration of the head can affect the enamel dose relative to external exposure to photons with energy below 100 keV.
Some data were derived using recent sophisticated methods to rapidly convert specific activity of induced 24Na to average dose over a whole body in criticality accidents. Monte Carlo calculations using the MCNP-4B code were performed to study energy spectra of neutrons and gamma rays for some criticality systems with fissile uranium. Absorbed dose to the human body and the activation of sodium were also analysed against external radiation by simulations using a MIRD-5 type phantom and the calculated energy spectra. It was found that the neutron dose assessment from induced 24Na would be important to give medical staff initial guidance for treatment of a victim. However, the energy distribution of incident neutrons to the human body did not significantly influence the conversion from the specific activity of 24Na to dose from gamma rays induced within a body. Analyses were made to clarify the dependence of conversion from 24Na specific activity to neutron dose on the orientation toward the source and the size of the human body. The total dose estimated based upon the obtained data ranged from 33 mGy to 514 mGy for a given specific activity of 1.4 kBq 24Na per g 23Na for some criticality assemblies. This study suggested that the size of uranium solution and material around the fuel should be defined to properly estimate the total dose, including the dose from external photons.
Osteopontin (OPN) is a phosphorylated glycoprotein with diverse functions including cancer development, progression and metastasis. Its expression is induced by a variety of stimuli such as TNF-alpha and Ras proto-oncogene. However, differential OPN expression and its regulation in each histologic type of lung cancer are not well established. In this study, we assessed expression of OPN in lung cancer tissues with immunohistochemical analysis. OPN was predominantly expressed in tumor cells of non-small cell lung cancer (NSCLC) tissues: 11 of 16 cases (68.8%) of squamous cell carcinoma (SCC), five of 24 cases (20.8%) of adenocarcinoma (AD), but only two of 18 cases (11%) of small cell lung cancer (SCLC). Expectedly, OPN was principally expressed in NSCLC cell lines (H322 cells and HL460 cells) but not in SCLC cell line (H69 cells) by Western blotting and Northern blotting. Interestingly, Ras-p21 was specifically co-expressed with OPN staining in eight of eight cases with SCC (100%), whereas it was demonstrated in three of ten cases (30%) with AD and only one of 18 cases (5%) with SCLC. Collectively, these results suggest that OPN is mainly expressed in NSCLC, especially among SCC. OPN expression may be tightly regulated by Ras oncogene, and its concomitant induction with Ras activation may play a crucial role in the development of SCC.
Lung fibrosis is an important pulmonary disease with a high mortality rate, but its pathophysiological mechanism has not been fully clarified. Various types of cells have been implicated in the development of lung fibrosis, including T cells. However, the contribution of functional molecules expressed on T cells to the development of lung fibrosis remains largely unknown. In this study, we determined whether costimulation via CD28 on T cells was crucial for the development of lung fibrosis by intratracheally administering bleomycin into CD28-deficient mice. Compared with wild-type mice, the CD28-deficient mice showed markedly impaired lung fibrosis after injection with low doses of bleomycin, as judged by histological changes and hydroxyproline content in the lungs. In addition, bleomycin-induced T cell infiltration into the airways and production of several cytokines and chemokines including IL-5 were also impaired in the CD28-deficient mice. Furthermore, adoptive transfer of CD28-positive T cells from wild-type mice recovered the impaired bleomycin-induced lung fibrosis in CD28-deficient mice. These findings suggest that the CD28-mediated T cell costimulation plays a critical role in the development of lung fibrosis, possibly by regulating the production of cytokines and chemokines in the lung. Thus, manipulation of the CD28-mediated costimulation could be a potential therapeutic strategy for the prevention of lung fibrosis.
Osteopontin (OPN) is a secreted glycoprotein with cell adhesive and chemoattractive functions and is expressed in granulomas of sarcoidosis. It is well documented that full-length OPN (F-OPN) is susceptible to proteolytic fragmentation resulting in carboxyl-terminal OPN (C-OPN). We have previously revealed that C-OPN suppresses cell adhesion mediated by F-OPN. However, the implication of F-OPN and C-OPN in the progression of pulmonary involvement in sarcoidosis has not yet been elucidated. In this study, we demonstrated that (l) OPN was expressed in granulomas of sarcoidosis, (2) plasma F-OPN level in patients with sarcoidosis, especially in stage II patients, was significantly elevated compared with those of the controls, (3) plasma C-OPN levels in patients of stages 0, I, and III were significantly higher than those of the controls, and (4) in vitro recombinant F-OPN induces macrophage migration and that C-OPN inhibits cell migration mediated by F-OPN. These results suggest that F-OPN may promote granuloma formation in sarcoidosis, while C-OPN may suppress it. Thus, OPN and its fragment may play distinct roles in the development of sarcoidosis.
A cDNA for cytochrome b(5) was cloned from a cDNA library of buds of the ascidian, Polyandrocarpa misakiensis, by a hybridization method involving a digoxigenin-labeled cDNA probe of human soluble cytochrome b(5). The nucleotide sequence of the cDNA for the ascidian cytochrome b(5) (Pmb5) consisted of about 1,800 base pairs including 5'- and 3'-noncoding regions, and a coding sequence of 405 base pairs. The amino acid sequence of 135 residues deduced from the coding nucleotide sequence exhibited 54% identity and 76% similarity to chicken cytochrome b(5). A highly conserved amino acid sequence was observed in the amino-terminal domain of 96 residues containing two heme-binding histidine residues. The putative soluble form of the recombinant Pmb5 expressed in Escherichia coli was purified to homogeneity by column chromatographies on an anion-exchanger and gel filtration. The purified Pmb5 showed the typical absorption spectrum of cytochrome b(5) with an asymmetric peak at 556 nm and a shoulder at 560 nm upon reduction with NADH and NADH-cytochrome b(5) reductase. The low temperature spectrum of the dithionite-reduced form of the protein contained the split peaks at 551 and 555 nm, this spectrum being very similar to that of mammalian liver cytochrome b(5). Expression of Pmb5 in the ascidian was examined immunohistochemically with a monoclonal antibody against the Pmb5. Apparently high level expression of Pmb5 was found in the developing buds, but the levels of cytochrome b(5) in the parents and juvenile adults were very low. This is the first report on the characterization of Pmb5, and the increased expression of Pmb5 in the ascidian.
An analysis of doses to tooth enamel and to organs was carried out to develop a method that can predict the organ doses and the effective dose by electron spin resonance (ESR) dosimetry using tooth samples for external photon exposure. Absorbed dose to tooth enamel and organ doses were obtained by Monte Carlo calculations using the EGS4 code in combination with a mathematical human model with a newly defined teeth part. The calculations gave quantitative relations between tooth enamel dose and organ doses for some cases of external photon exposure. It was also found that tooth enamel dose depends more significantly on energy of incident photons than the other organ dose or the effective dose. The obtained data are to be useful for the assessment of individual dose in past exposure events by the ESR dosimetry using tooth enamel.
When a narrow region of the fresh water coenocytic alga, Vaucheria terrestris sensu Götz is irradiated with moderately intense blue light, a branch is induced from the center of the irradiated region after 4-5 h. Movement of organelles and microtubule bundles during the photocytomorphogenetic response were investigated. Chloroplasts in the cortical layer immediately started to accumulate in the blue light-irradiated region and their accumulation almost completely finished 30-40 min after the onset of light when the nuclei residing in endoplasm started to accumulate. Accumulation of nuclei was synchronized with disorientation and shortening of microtubule bundles, which originally run parallel to the cell axis. Not only amiprophos-methyl, a potent microtubule-decomposing reagent, but also cytochalasin A strongly inhibited the branch induction. Amiprophos-methyl completely and cytochalasin A mostly destroyed microtubules and completely inhibited nuclear accumulation, but both drugs allowed the accumulation of chloroplasts in the cortical layer of irradiated region. These indicate that the accumulation of nuclei is indispensable for branch induction while the chloroplast accumulation is insufficient by itself for branch induction. The ineffectiveness of cytochalasin A on chloroplast movement brings the conventional view of sliding movement of chloroplast on a long actin cable into question. The morphological and functional relationship between a nucleus and a microtubular bundle are discussed.
Pulmonary fibrosis is initiated by migration, adhesion, and proliferation of fibroblasts. Osteopontin (OPN) is one of the cytokines produced by activated macrophages and mediates various functions, including cell attachment and migration, by interacting with alphav integrin. In this study, we have investigated the role of OPN in the pathogenesis of pulmonary fibrosis. We developed a mouse model for pulmonary fibrosis by intratracheal instillation of bleomycin (BLM). OPN was strongly expressed in alveolar macrophages accumulating in the fibrotic area of the lung. OPN messenger RNA (mRNA) in the lung was notably induced by BLM instillation, and the development of the fibrotic process was associated with an increase in the expression of OPN mRNA and protein. In vitro, recombinant OPN enhanced migration, adhesion, and platelet-derived growth factor (PDGF)-mediated DNA synthesis of murine fibroblast cell line NIH3T3. These effects of OPN on fibroblasts were significantly suppressed by addition of antimouse alphav integrin monoclonal antibody (RMV-7). Furthermore, treatment of mice with RMV-7 repressed the extent of pulmonary fibrosis in this model. Conclusively, these data suggest that OPN produced by alveolar macrophages functions as a fibrogenic cytokine that promotes migration, adhesion, and proliferation of fibroblasts in the development of BLM-induced pulmonary fibrosis.
Dorsal closure (DC) in the Drosophila embryo requires the coordinated interaction of two different functional domains of the epidermal cell layer-the leading edge (LE) and the lateral epidermis. In response to activation of a conserved c-Jun amino-terminal kinase (JNK) signaling module, the dorsal-most layer of cells, which constitute the LE of the stretching epithelial sheet, secrete Dpp, a member of the TGFbeta superfamily. Dpp and other LE cell-derived signaling molecules stimulate the bilateral dorsal elongation of cells of the dorsolateral epidermis over the underlaying amnioserosa and the eventual fusion of their LEs along the dorsal midline. We have found that flies bearing a Shark tyrosine kinase gene mutation, shark(1), exhibit a DC-defective phenotype. Dpp fails to be expressed in shark(1) mutant LE cells. Consistent with these observations, epidermal-specific reconstitution of shark function or overexpression of an activated form of c-Jun in the shark(1) mutant background, rescues the DC defect. Thus, Shark regulates the JNK signaling pathway leading to Dpp expression in LE cells. Furthermore, constitutive activation of the Dpp pathway throughout the epidermis fails to rescue the shark(1) DC defect, suggesting that Shark may function in additional pathways in the LE and/or lateral epithelium.
Nitric oxide (NO) produced by macrophages is thought to contribute to various pathological conditions. Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of NO production. However, the relationship between NO and endogenous OPN in activated macrophages has not yet been elucidated. We therefore examined expression of endogenous iNOS and OPN in a murine macrophage cell line, RAW 264.7 cells, by treating the cells with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Treatment of cells with LPS and IFN-gamma resulted in an increase of iNOS mRNA to maximum at 12 h after stimulation. In contrast, OPN mRNA was induced more slowly than iNOS mRNA. Induction of both iNOS and OPN mRNA in RAW 264.7 cells was markedly suppressed by addition of the specific iNOS inhibitor S-2-aminoethyl isothiourea dihydrobromide. The NOS inhibitor NG-methyl-L-arginine also suppressed induction of OPN mRNA but hardly affected iNOS mRNA expression. The NO-releasing agent spermine-NONOate but not peroxynitrite enhanced induction of OPN mRNA. These results suggest that NO directly up-regulates the endogenous OPN in macrophages stimulated with LPS and IFN-gamma. This up-regulation of endogenous OPN may represent a negative feedback system acting to reduce iNOS expression.
We report the case of a 62-year-old man with nephrotic syndrome associated with stage B chronic lymphocytic leukemia (CLL). Kappa Bence Jones proteinuria and the glomerular deposition of kappa-light chain were observed. Although treatment with cyclophosphamide and prednisolone tended to reduce the level of proteinuria, the administration of angiotensin-converting enzyme inhibitor, enalapril, resulted in complete remission of nephrotic syndrome.
The double blind study of the effect of caffeine on the mental calculation has been carried out in the practical exercise course for the undergraduate students of clinical pharmacology, in the Medical School, Kyushu University. The results obtained from 1997 to 1999 were summarized and evaluated.
An immobilized polyacrylamide gel containing beta-D-galactosidase and Sr-Ba-ferrite was magnetized in a static magnetic field. The gel rods (10 mm long, O 2 mm) exhibiting magnetic anisotropy could move at lower than 100 Hz but not at higher than 250 Hz in an alternating magnetic field of 200 Oe. In case of immovability of gel rods, the apparent enzymic activity increased 3 times higher under exposure of an alternating magnetic field of 500 Oe (570 Hz). It could be explained that the ferromagnetic powder inside the gel might vibrate under the influence of elasticity of gel in the alternating magnetic field of 100 or 500 Oe and 0.2-12 kHz. This might facilitate faster diffusion of the substance inside the gel and transportation of the substrate and the product through the surface of gel. Consequently, the enzyme reaction was apparently activated.
Use of methanol or ethanol in the magneto-biotechnological technique was found to be enhance citric acid production in a magnetic drum contactor operation with Aspergillus niger AJ 117173. Continuous and repeated-batch fermentations were conducted with the addition of 2% ethanol. Continuous fermentation for 50 d gave a better citric acid yield (85%) and average productivity (3.8 g.l(-1).d(-1)) than repeated-batch fermentation over 60 d (65%, 2.3 g.l(-1).d(-1)).
There is a clinically significant correlation between the presence of an antibody against the paraneoplastic encephalomyelitis antigen HuD and the limitation of tumor spread in patients with small-cell lung cancer (SCLC). This suggests that HuD is a possible target molecule for antitumor immunotherapy against SCLC. We have hypothesized that anti-HuD immunity suppresses in vivo growth of HuD-expressing tumor cells. In this study, Colon 26, a murine adenocarcinoma cell line, stably transfected with the HuD gene (Colon 26/HuD cell) was used as a target cell, and the immunity against HuD was evoked by intramuscular injection of a HuD-expressing plasmid, a technique of DNA vaccination previously used in BALB/c mice. Colon 26/HuD cells were injected subcutaneously and tumor size was calculated as a product of width and length. Antitumor activity was investigated by using two different lots of Colon26/HuD cells in two protocols: Protocol 1, in which either Colon 26/HuD or Colon 26 cells were injected in each side, and Protocol 2, in which Colon 26/HuD cells alone were injected. The size of Colon 26/HuD tumors obtained from mice vaccinated with HuD-expressing plasmid was significantly smaller than those from negative control plasmid-vaccinated mice (86.6 +/- 29.9 versus 195.3 +/- 48.1 mm2, P < 0.05 in Protocol 1; 107.7 +/- 12.8 versus 156.6 +/- 22.8 mm2, P < 0.05 in Protocol 2). Moreover, the de novo DNA synthesis of spleen cells obtained from HuD-vaccinated mice was significantly enhanced. In addition, anti-HuD antibody was found in individual sera obtained from HuD-vaccinated mice. DNA vaccination with mouse HuD antigen suppressed HuD-expressing tumor growth in a murine SCLC model.
Dietary Pi and parathyroid hormone (PTH) are two most important physiological and pathophysiological regulators of Pi re-absorption in the renal proximal tubule. Effects of dietary Pi on Na+/Pi co-transporter NaPi-2 were investigated in thyroparathyroidectomized (TPTX) rats. NaPi-2 protein and mRNA in the kidney cortex of TPTX rats were increased approximately 3.8- and 2.4-fold in amount respectively compared with those in the sham-operated animals. Administration of PTH to the TPTX rats resulted in a decrease in the amount of NaPi-2 protein, but not in the abundance of NaPi-2 mRNA. Deprivation of dietary Pi in the TPTX rats did not affect the amount of NaPi-2 mRNA and protein. In the Pi-deprived TPTX rats, feeding of a high-Pi diet resulted in marked decreases in Pi transport activity and the amount of NaPi-2 protein in the superficial nephrons. Immunohistochemical analysis demonstrated that administration of PTH to TPTX rats resulted in a decrease in NaPi-2 immunoreactivity from both superficial and juxtamedullary nephrons within 4 h. Switching TPTX animals from a low-Pi diet to the high-Pi diet decreased NaPi-2 immunoreactivity from superficial nephrons, but not from juxtamedullary nephrons, within 4 h. These results suggest that dietary Pi could regulate the amount of NaPi-2 protein in the superficial nephrons in a PTH-independent manner.