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Biomedical subjects

M Adachi

Publications and source records attributed to M Adachi.

At least 253 records · Page 14Linked to original sources

Effect of theophylline withdrawal on airway inflammation in asthma.

Theophylline has been used as a bronchodilator in acute and chronic asthma management, although there is accumulating evidence that it may have anti-inflammatory effects. We have investigated the effect of theophylline withdrawal for 6 weeks in asthmatic subjects whose peak expiratory flow (PEF) readings were more than 80% of the predicted value and its variability was less than 20% (Green Zone) by treatment with both a moderate dose of inhaled corticosteroids (BDP), 400-800 microg/day) and low dose theophylline (400 mg/day) for more than 3 months. In 38 asthmatic subjects, changes in clinical symptoms, respiratory function and airway inflammation detected with hypertonic saline induced sputum, and airway reactivity to histamine were investigated. One half of the patients were randomly withdrawn from theophylline, while the other half continued to take the same dose of theophylline for a period of 6 weeks. Mean steady state plasma theophylline concentrations when receiving treatment with theophylline were 8.08 microg/mL in the theophylline withdrawal group and 7.64 microg/mL in the control theophylline group, respectively. Although a significant increase in asthma symptoms emerged in the theophylline group, there were no significant changes in the theophylline administration group. In the theophylline withdrawal group, there were small but significant falls in PEF in the morning, FEV1 and V50 at the end of the study period. Analysis of induced sputum showed that there was also a significant increase in the percentage of total and activated (EG2+) eosinophils only in those patients who withdrew from theophylline. These results indicate that chronic treatment with low dose theophylline exerts an anti-inflammatory effect and that the additional use of theophylline with inhaled corticosteroids provides an effective treatment for moderate asthma. Taken together, we conclude that theophylline has long-term beneficial effects on the chronic asthma management.

Administration, Oral↗

[Effect of slow-release theophylline on airway inflammation in bronchial asthma].

Theophylline has been used as a bronchodilator in acute and chronic asthma management but recent evidences suggest that it has anti-inflammatory effects. Therefore, we investigated the therapeutic effect of slow-release theophylline in mild to moderate asthmatic patients. Symptomatic 19 patients with mild asthma who were treated with inhaled beta 2-agonist alone, and 17 subjects with moderate asthma who were treated with moderate dose of inhaled corticosteroid (beclomethasone dipropionate, BDP, 400-800 micrograms/day) were enrolled to the present study. After two-week run-in period, slow-release theophylline was administered for six to eight weeks and asthma symptoms, respiratory function, airway inflammation evaluated by the inhalation of hypertonic saline, and airway reactivity to histamine were investigated during observation period and after treatment. Asthma symptom score was significantly improved after theophylline treatment in both groups. Morning peak expiratory flow was significantly elevated but FEV1 was not significantly improved by the additional treatment with slow-release theophylline in both groups. Significant decreases in the percentages of total and EG2 + eosinophils in induced sputum demonstrated that slow-release theophylline has anti-inflammatory effect in patients with asthma despite the treatment with inhaled corticosteroid. Because recent reports suggest that theophylline may act as an anti-inflammatory drug even in low dose concentration, we also investigated the effect of plasma theophylline concentration on the airway inflammation. Patients were divided into two groups by the plasma concentration of theophylline, more than 10 micrograms/mL which is necessary to dilate airway and below 10 micrograms/mL, referred to as low dose concentration of theophylline. The results suggest that the administration of slow-release theophylline significantly decreased the percentages of both total and EG2 + eosinophils in induced sputum in both concentration groups. However, airway reactivity to histamine did not significantly change by the treatment. Taken together, we conclude that low dose treatment of slow-release theophylline has an anti-inflammatory effect and treatment with slow-release theophylline alone or the additional use with inhaled corticosteroid is an effective therapy for the management of mild to moderate asthma.

Adult↗

[Intraoperative CT imaging system using a mobile CT scanner gantry mounted on floor-embedded rails for neurosurgery].

Many neurosurgeons prefer to use intraoperative computed tomographic (CT) scanning, when possible, to check whether there is residual lesion or unexpected bleeding. We report a practical intraoperative CT imaging system using a high-speed CT scanner installed in the operating room along with a digitally controlled neurosurgical operating table. We designed a rail-track system to mobilize the CT gantry. The gantry is fixed onto a motorized carrier that can be moved smoothly on a rail-track embedded in the floor and with a maximum reach of 2.85 m from the room's wall to the operating table. The longitudinal motion of the operating table is easily adjusted by a foot switch from manual control to automatic control directly from the CT scanner's computer like an ordinary CT scanner bed in increments of 2, 5 or 10 mm during CT scanning. Either a carbon-made radiolucent head frame or carbon-made head plate is used as a headrest. Using this CT scanner system, pre- and intraoperative CT scannings were performed on 46 patients with brain tumors, cervical lesions or other intracranial lesions. We could operate on the patient with enough working space between the mobile CT gantry and the operating table for microneurosurgery. We could obtain intraoperative CT imaging of a patient on the operating table while the surgical wound remained open, the surgical drapes kept in place, and the surgical position unchanged, saving time in intraoperative CT scanning and preparation for further surgery when needed. This intraoperative CT imaging system installed in the operating room should be useful for neurosurgery.

Brain↗

A novel regulatory mechanism in the mitogen-activated protein (MAP) kinase cascade. Role of nuclear export signal of MAP kinase kinase.

Mitogen-activated protein kinase (MAPK) kinase (MAPKK, also known as MEK), a direct activator for MAPK/extracellular signal-regulated kinase, localizes to the cytoplasm excluded from the nucleus during signal transmission. This nuclear exclusion of MAPKK is directed by its nuclear export signal (NES), but its physiological significance has been unknown. We have found that disruption of the NES dramatically potentiates the ability of constitutively active MAPKK to induce morphological changes and malignant transformation of fibroblastic cells. Readdition of the NES sequence reversed the effects induced by the NES disruption. Moreover, we observed that a dramatic increase of activated MAPK in the nucleus was induced by the NES-disrupted MAPKK and that coexpression of MAPK phosphatase-1 (CL-100) or a kinase negative form of MAPK counteracted the phenotypes induced by the NES-disrupted MAPKK, indicating the crucial role of MAPK in the responses. These findings reveal a novel regulatory role of the NES of MAPKK that may be essential for proper signal transductions.

Animals↗

A novel gastric-cancer-associated mucin antigen defined by a monoclonal antibody A3D4.

De-glycosylation of mucins may expose new tumor-associated core protein epitopes. In this study, to attempt to develop useful markers for gastric cancers, we have purified and de-glycosylated gastric mucin and tried to establish monoclonal antibodies (MAbs). A MAb designated A3D4 among established MAbs was shown to react with gastric cancer with high frequency, but not with normal gastric epithelium. Among normal digestive organs, only the colon and gall bladder were positive for MAb A3D4. The incidence of positivity in gastric cancer was 75% for intestinal-type adenocarcinoma (n = 28), 40% for solid-type adenocarcinoma (n = 5) and 33% for signet/scirrhous-type adenocarcinoma (n = 15). Interestingly, adenoma and intestinal metaplasia (IM) with chronic gastritis or peptic ulcer were negative for MAb A3D4, whereas 8 out of 13 cases (62%) of IM with gastric cancer was positive. Western-blot analysis using the lysate from normal colon tissues revealed a high-molecular-weight (> 300-kDa) smear-like band. Immunohistochemical analysis indicated that the reactivity of MAb A3D4 was clearly increased when tissue sections were pre-treated with periodic acid or O-glycanase, while it was decreased by pre-treatment with trypsin or protease V8. There was no reactivity with the synthetic peptide encompassing the tandem-repeat sequence of MUC2 or MUC3. These data suggest that MAb A3D4 detects a novel gastric-cancer-associated mucin antigen whose epitope may be peptide in nature.

Adenocarcinoma↗

CRM1 is responsible for intracellular transport mediated by the nuclear export signal.

The discovery of nuclear export signals (NESs) in a number of proteins revealed the occurrence of signal-dependent transport of proteins from the nucleus to the cytoplasm. Although the consensus motif of the NESs has been shown to be a leucine-rich, short amino-acid sequence, its receptor has not been identified. A cytotoxin leptomycin B (LMB) has recently been suggested to inhibit the NES-mediated transport of Rev protein. Here we show that LMB is a potent and specific inhibitor of the NES-dependent nuclear export of proteins. Moreover, we have found a protein of relative molecular mass 110K (p110) in Xenopus oocyte extracts that binds to the intact NES but not to the mutated, non-functional NES. The binding of p110 to NES is inhibited by LMB. We show that p110 is CRM1, which is an evolutionarily conserved protein originally found as an essential nuclear protein in fission yeast and known as a likely target of LMB. We also show that nuclear export of a fission yeast protein, Dsk1, which has a leucine-rich NES, is disrupted in wild-type yeast treated with LMB or in the crm1 mutant. These results indicate that CRM1 is an essential mediator of the NES-dependent nuclear export of proteins in eukaryotic cells.

Animals↗

IFN-gamma upregulates anti-apoptotic gene expression and inhibits apoptosis in IL-3-dependent hematopoietic cells.

IFN-gamma is a cytokine which functions in a wide range of biological activities by inducing a number of early and delayed genes. In murine IL-3-dependent cell lines BAF-B03 and 32D, IFN-gamma upregulated bag-1 and bcl-xL gene expression. These cells revealed prolonged cell survival against IL-3-deprivation by IFN-gamma stimulation. In contrast, human myeloma cell line RPMI8226, despite expression of IFN-gamma receptor, showed neither induction of their expressions nor prolonged cell survival against serum starvation-induced apoptosis by IFN-gamma stimulation. Gene-transfer-mediated overexpression of BAG-1 protein in BAF-B03 cells led to prolonged cell survival against IL-3-deprived apoptosis compared with control BAF-B03 transfectants, indicating that levels of BAG-1 expression are crucial for cell survival in BAF-B03 cells. Taken together, these studies suggest that induction of anti-apoptotic gene expression is a crucial factor for the anti-apoptotic function of IFN-gamma in IL-3-dependent immature hematopoietic cells.

Animals↗

Increased sensitivity of gastric cancer cells to natural killer and lymphokine-activated killer cells by antisense suppression of N-acetylgalactosaminyltransferase.

UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc transferases) catalyze the initial reaction in O-linked (mucin type) oligosaccharide biosynthesis. To attempt to inhibit the synthesis of O-glycan, we transfected antisense cDNA of GalNAc transferase type 1 (GalNAc-T1) into a human gastric cancer cell line, JRST. A decreased expression of GalNAc-T1 at the level of both mRNA and protein was observed in the resultant transfectants. They demonstrated a significantly increased sensitivity to NK and lymphokine-activated killer cells in vitro compared with parental cells and mock transfectants. Although there was no significant difference in in vitro cell proliferation among parental cells, mock transfectants, or antisense transfectants, the in vivo growth rate of antisense transfectants using SCID mice was clearly lower than that of parental cells and mock transfectants. Furthermore, the treatment of mice with anti-asialo-G(M1) Ab abolished this growth-inhibitory effect of antisense transfection. From these results, we conclude that antisense suppression of GalNAc-T1 could increase the sensitivity of tumor cells to NK and lymphokine-activated killer cells, suggesting that this strategy may be of use as a new immunogene therapy.

Animals↗

Features of macrophage differentiation induced by p19INK4d, a specific inhibitor of cyclin D-dependent kinases.

The mitogen-dependent induction of cyclin D-dependent kinase activity is required for cells to enter the DNA synthetic (S) phase of their division cycle. Immature 32Dcl3 myeloid cells (32D) proliferating in the presence of interleukin-3 (IL-3) normally express cyclins D2 and D3, which assemble into binary holoenzyme complexes with their catalytic subunits, CDK4 and CDK6. When 32D cells are switched to medium containing granulocyte colony-stimulating factor (G-CSF) instead of IL-3, D-type cyclins are degraded and, in the absence of their associated kinase activity, the cells arrest in the first gap phase (G1) of the cell cycle and differentiate to neutrophils. We derived 32D cells in which the expression of p19INK4d, a specific polypeptide inhibitor of CDK4 and CDK6, is regulated by the heavy metal-inducible sheep metallothionein promoter. Induction of p19INK4d in response to zinc prolonged cell survival in the absence of growth factor treatment. When maintained in medium containing both IL-3 and zinc, these cells lost cyclin D-dependent kinase activity, underwent G1 phase arrest, and acquired certain morphologic, antigenic, and functional properties of mononuclear phagocytes. Cells induced to express p19INK4d did not synthesize receptors for macrophage colony-stimulating factor (M-CSF/CSF-1) and reverted to an immature myeloid phenotype when shifted back into medium containing IL-3 alone. These cells exhibited accelerated differentiation to neutrophils in response to G-CSF but also gave rise to macrophage-like cells when maintained in medium containing both G-CSF and zinc. Therefore, the acquisition of macrophage properties in response to zinc treatment neither depended upon IL-3 nor upon G1 phase arrest per se and instead reflects some ability of p19INK4d, and presumably cyclin D-dependent kinases, to affect myeloid differentiation.

Carrier Proteins↗

Anti-cell death activity promotes pulmonary metastasis of melanoma cells.

Bcl-2 inhibits apoptosis from a variety of stimuli, and a Bcl-2-binding protein BAG-1 also functions in protection from apoptosis in concert with Bcl-2. Here, we provide evidence that prolonged cell survival introduced by overexpression of Bcl-2 or BAG-1 proteins strongly promotes experimental pulmonary metastasis of melanoma B16-BL6 cells. In murine melanoma cell line B16-BL6, gene transfer-mediated expression of the Bcl-2 or BAG-1 led to prolonged cell survival against serum-starved apoptosis in vitro. The Bcl-2-expressing B16 cells, B16-Bcl-2 and the BAG-1-expressing B16 cells, B16-BAG-1 strongly enhanced pulmonary metastasis in allogenic BALB/c nude mice and whole lung weights were increased by 2.4-fold and 1.4-fold, respectively, compared with control transfectants, suggesting that Bcl-2 is a stronger positive modulator of metastasis. When the viable B16-Bcl-2 and control transfectants were injected subcutaneously into BALB/c nude mice, the colony numbers of pulmonary metastasis of the B16-Bcl-2 transfectant increased by 5.6-fold compared with the control transfectants. These enhanced metastatic potentials in the B16-Bcl-2 and the B16-BAG-1 transfectants were well correlated with anti-cell death activity against serum-starvation and enhanced cell viability on limiting dilution. Analysis of the transfectants however revealed that their growth rates, invasive ability and cell motility were not significantly altered by overexpression of either Bcl-2 or BAG-1 proteins. Taken together, these studies demonstrate that prolonged cell survival is a crucial factor to promote metastasis of melanoma, thereby contributing to tumor progression.

Animals↗

Purification, cDNA cloning, and characterization of a new serpin with megakaryocyte maturation activity.

A new member of the serine protease inhibitor (serpin) superfamily with megakaryocyte maturation activity was purified, and its cDNA was cloned and characterized. The predicted amino acid sequence consisting of 380 residues was unique and was 38% identical to the serpin plasminogen activator inhibitor type 2 (PAI-2). The recombinant factor expressed in Chinese hamster ovary cells showed species-specific activity on the induction of megakaryocyte maturation in vitro. When injected into mice, the factor indeed elicited an increase in the number of platelets in plasma. The sequence alignment indicated that the factor possessed a lysine residue at the P1 position, suggesting that it might function as an inhibitor of Lys-specific proteases. Although we could not show any inhibitory activities toward several known Lys-specific proteases, we detected the activity toward protease activity present in the culture supernatant of COLO 201 cells. These results suggested that the protein might influence the maturation of megakaryocytes via action as a serpin.

Amino Acid Sequence↗

Expression and identification of aberrant c-kit transcripts in human cancer cells.

We have previously cloned and sequenced a novel 3.5 kb c-kit mRNA expressed in a colon carcinoma cell line Colo201. Here we examined the expression of this truncated form of c-kit in 14 gastrointestinal cancer cells and 16 hematopoieic cancer cells by RT-PCR. Expression of the aberrant c-kit transcript was observed in various cancer cell lines. Furthermore, a new transcript which is 78 bp shorter than the transcript previously described was identified and characterized. These results indicate that two kinds of aberrant c-kit transcript produced by alternative promoter in intron 15 are expressed in human cancer cells.

Adenocarcinoma↗

Immunohistochemically detected expression of motility-related protein-1 (MRP-1/CD9) in lung adenocarcinoma and its relation to prognosis.

Motility-related protein-1 (MRP-1)/CD9 is a trans-membrane glycoprotein closely associated with suppression of cell motility and reduced metastatic potential of some tumor cells. We currently report that, according to the RT-PCR method for MRP-1/CD9 gene expression, patients with low expression of MRP-1/CD9 in non-small-cell lung cancer, especially the adenocarcinoma type, showed short overall survival. Then, to determine accurately the prognostic value of MRP-1/CD9 product levels in lung-adenocarcinoma cells, we immunohistochemically investigated its expression in 132 lung-adenocarcinoma patients undergoing potentially curative surgery. Of these patients, 44 (33%) showed reduced expression of MRP-1/CD9 in cancer cells, and an inverse association was observed between its expression and factors associated with tumor progression, such as nodal involvement (p = 0.029) or stage (p = 0.028). Patients with reduced expression of MRP-1/CD9 showed a significantly worse prognosis in overall survival (p = 0.005) and disease-free survival (DFS; p < 0.0001) than those with stronger expression; and even among patients with stage-I disease, similar results were obtained (overall survival, p = 0.038; DFS, p = 0.012). In a multivariate analysis, immunohistochemical MRP-1/CD9-expression level was an independent prognostic factor for DFS (p = 0.021), but not for overall survival (p = 0.572). Thus, immunohistochemical MRP-1/CD9-expression level solely in lung-adenocarcinoma cells within the tumor tissue appears to be a prognostic factor for DFS, and may be useful for detecting a high-risk sub-group of recurrence during the post-operative clinical course of the disease.

Adult↗