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M Dohi

Publications and source records attributed to M Dohi.

At least 19 recordsLinked to original sources
PubMed2006

In vivo IL-10 gene delivery attenuates bleomycin induced pulmonary fibrosis by inhibiting the production and activation of TGF-beta in the lung.

BACKGROUND: Idiopathic pulmonary fibrosis is a devastating disorder for which there is no effective treatment. Transforming growth factor (TGF)-beta plays a critical role in provoking fibrosis. Interleukin (IL)-10 is a potent immunosuppressive cytokine but its effect on the fibrosing process is unclear. A study was undertaken to examine whether IL-10 affects the production and activation of TGF-beta and thus can attenuate the fibrosis. METHODS: Mice were given an intratracheal injection of bleomycin. On day 1 or 14, IL-10 gene was delivered by rapid intravenous injection of Ringer's solution containing plasmid. Two weeks after the plasmid injection the mice were examined for fibrosis. The effect of IL-10 on TGF-beta production by alveolar macrophages was assessed. RESULTS: Even when delivered during the fibrosing phase, IL-10 gene significantly suppressed the pathological findings, hydroxyproline content, and production of both active and total forms of TGF-beta1 in the lung. Immunohistochemical analyses showed that alveolar macrophages were one of the major sources of TGF-beta1 and IL-10 diminished the intensity of the staining. IL-10 also suppressed the expression of alphaV beta6 integrin, a molecule that plays an important role in TGF-beta activation, on lung epithelial cells. Alveolar macrophages from bleomycin injected mice produced TGF-beta1 spontaneously ex vivo, which was significantly suppressed by treatment of the mice in vivo or by treatment of the explanted macrophages ex vivo with IL-10. CONCLUSION: IL-10 suppresses the production and activation of TGF-beta in the lung and thus attenuates pulmonary fibrosis, even when delivered in the chronic phase.

Animals↗
PubMed2001

Early interleukin 4-dependent response can induce airway hyperreactivity before development of airway inflammation in a mouse model of asthma.

In experimental models of bronchial asthma with mice, airway inflammation and increase in airway hyperreactivity (AHR) are induced by a combination of systemic sensitization and airway challenge with allergens. In this report, we present another possibility: that systemic antigen-specific sensitization alone can induce AHR before the development of inflammation in the airway. Male BALB/c mice were sensitized with ovalbumin (OVA) by a combination of intraperitoneal injection and aerosol inhalation, and various parameters for airway inflammation and hyperreactivity were sequentially analyzed. Bronchial response measured by a noninvasive method (enhanced pause) and the eosinophil count and interleukin (IL)-5 concentration in bronchoalveolar lavage fluid (BALF) gradually increased following the sensitization, and significant increase was achieved after repeated OVA aerosol inhalation along with development of histologic changes of the airway. In contrast, AHR was already significantly increased by systemic sensitization alone, although airway inflammation hardly developed at that time point. BALF IL-4 concentration and the expression of IL-4 mRNA in the lung reached maximal values after the systemic sensitization, then subsequently decreased. Treatment of mice with anti-IL-4 neutralizing antibody during systemic sensitization significantly suppressed this early increase in AHR. In addition, IL-4 gene-targeted mice did not reveal this early increase in AHR by systemic sensitization. These results suggest that an immune response in the lung in an early stage of sensitization can induce airway hyperreactivity before development of an eosinophilic airway inflammation in BALB/c mice and that IL-4 plays an essential role in this process. If this early increase in AHR does occur in sensitized human infants, it could be another therapeutic target for early prevention of the future onset of asthma.

Allergens↗
PubMed2000

Development of mushrooms for thrombosis prevention by protoplast fusion.

With thrombosis a major cause of death in Japan and the Western world, thrombin-inhibitory agents that constrain the formation of fibrin are sought. We screened for basidiomycetes showing anti-thrombin activity and isolated Laetiporus sulphureus. However, it was difficult to cultivate and its form was not satisfactory. We therefore used protoplast fusion between L. sulphureus and the commonly cultivated basidiomycete Hypsizygus marmoreaus to obtain cultivable basidiomycetes that produced an anti-thrombin substance. For the protoplast fusion of L. sulphureus and H. marmoreaus, the protoplast concentration, alternating electric field intensity, dielectrophoresis duration, and field pulse intensity used were of 1 x 10(7) protoplasts/ml, 100 V/cm.1 MHz, 60 s, and 8 kV/cm, respectively. The number of regenerated colonies obtained was 4961, from which 43 strains were selected for electrophoretic analysis. Four of the fusants were found to have a band from each parent in isozyme patterns obtained using their crude extract. The fruiting bodies of the fusants were very similar to those of H. marmoreaus. Crude extract from each of the fusants and from L. sulphureus showed anti-coagulative activity in terms of the thrombin clotting time. We thus obtained improved basidiomycetes that produce an anti-thrombin substance, are easily cultivated, and whose form resembles H. marmoreaus, a commonly used culinary mushroom.

Journal Article↗
PubMed2000

Analysis of 3-D human foot forms using the Free Form Deformation method and its application in grading shoe lasts.

An effective way to design well-fitting products is to analyse human body forms and to classify them into several groups. In the present study, a new method is proposed to analyse human body forms using the FFD (Free Form Deformation) technique. The FFD method is a way to deform the shapes of object smoothly by moving control lattice points set around the object. The reference body form is automatically deformed to coincide with the other body forms using the FFD method. The dissimilarity is defined by the movements of the control lattice points. The foot forms of 56 Japanese adult females were analysed with this method, and distributions for them were calculated using multi-dimensional scaling. The first axis contrasts feet with high dorsal arches and low dorsal arches, and the second axis is related to the antero-posterior proportion of the foot. As an application of the present method, a last of width EEEE was designed from an existing last of width E by applying the control lattice points that converted a representative foot of width E into a foot of width EEEE. The new EEEE width last reflected the allometric differences between narrow and wide feet better than one obtained by a conventional method. It was found that the present method with FFD is not only useful for classifying 3-D human body forms, but also has potential as applications for designing well-fitting products.

Adult↗
PubMed2000

Hepatocyte growth factor attenuates collagen accumulation in a murine model of pulmonary fibrosis.

We investigated the in vivo effects of recombinant human hepatocyte growth factor (HGF) on epithelial cell proliferation in normal mouse lung and on the repair process that follows bleomycin-induced lung injury. Intratracheal administration of 100 micrograms of rhHGF to C57BL/6 mice led to proliferation of bronchial and alveolar epithelial cells as indicated by an increased number of cells staining for proliferating cell nuclear antigen (PCNA). The effect of HGF on the lung repair process was examined by administration of 100 micrograms of rhHGF on Day 3 and Day 6 after intratracheal injection of bleomycin to mice. We found that HGF significantly attenuated collagen accumulation induced by bleomycin as determined by quantitation of hydroxyproline content and by scoring of the extent of fibrosis. To explore the potential mechanisms involved in the beneficial effects of HGF, we performed in vitro studies with A549 pulmonary epithelial cells and found that HGF enhanced cell surface plasmin generation, expression of u-PA activity, and cell migration. In summary, HGF has potent in vivo and in vitro effects on epithelial cells, which suggests it may have a role in the therapy of pulmonary fibrosis.

Analysis of Variance↗
PubMed1999

Interferon-gamma upregulates the c-Met/hepatocyte growth factor receptor expression in alveolar epithelial cells.

In the repair process after lung injury, the regeneration of alveolar epithelial cells plays an important role by covering the damaged alveolar wall and preventing the activated fibroblasts from invading the intra- alveolar spaces. Hepatocyte growth factor (HGF) is a potent mitogen for alveolar epithelial cells and has been reported to be capable of repressing the fibrosing process by connecting to the c-Met/HGF receptor on alveolar epithelial cells. However, it has been reported that the c-Met expression was downregulated in an acute phase of lung injury, which may limit the effect of HGF for therapeutic use. In the present study we observed that interferon (IFN)-gamma upregulates the c-Met messenger RNA (mRNA) and protein expression in A549 alveolar epithelial cells. We analyzed the mechanism of this upregulation and found that IFN-gamma enhances the transcription of the c-met proto-oncogene, and that it does not prolong the stability of the c-Met mRNA. HGF is known to act as a motogen as well as a mitogen for epithelial cells. We also found that the migratory activity of A549 cells induced by HGF is strongly enhanced by preincubation with IFN-gamma. Finally, we administered recombinant IFN-gamma to C57BL/6 mice and confirmed that this upregulation is also observed in vivo. These results suggest that the combination of HGF and IFN-gamma could be a new therapeutic approach for fibrosing pulmonary diseases.

Animals↗
PubMed1999

[MR temperature monitoring by the proton phase shift (PPS) method with a 0.3T open-type MR scanner: experimental study].

Several MR parameters are sensitive to temperature change, notably, T1 relaxation time, proton phase shift (PPS) and diffusion coefficient. The PPS method has been considered for temperature monitoring during laser ablation owing to its tissue-independence and its ability to be used with a mid-magnetic field. Using the PPS method, we experimentally evaluated MR temperature monitoring with a 0.3T open-type MR scanner. Temperature change was reproducibly described as color mapping image. The PPS method was suitable for MR temperature monitoring in interventional MRI.

Magnetic Resonance Imaging↗
PubMed1999

Noninvasive system for evaluating the allergen-specific airway response in a murine model of asthma.

In the present report, we show that the enhanced pause (Penh), a novel indicator of airway responsiveness to bronchoconstrictors, can also be a good marker of airway response to an allergen challenge in a murine model of asthma. Male BALB/c mice were sensitized with ovalbumin (OVA) through a combination of intraperitoneal injection and aerosol inhalation. After this immunization, the OVA-specific IgE titer in serum increased to a significantly higher level than in a saline/PBS-treated control group. After the final OVA aerosol challenge, Penh was repeatedly measured in conscious, unrestrained mice, according to the time schedule. Penh increased gradually after the challenge and reached a maximal value at 24 hours that was significantly higher than the control value (p < 0.01). Histologic examination of the lung revealed airway inflammation with an invasion by eosinophils and lymphocytes from vessels into the peribronchial interstitium and the mucosal and submucosal areas of the bronchus. There was a strong correlation between the Penh value and eosinophil number in bronchoalveolar lavage fluid (r = 0.699, p < 0.0001). Moreover, Penh also correlated strongly with the intensity score of histologic findings. These results suggest that the bronchial response to a specific allergen could be followed in a particular individual through the noninvasive Penh method, and that Penh accurately reflects the intensity of eosinophilic bronchial inflammation. This system would be applicable to a noninvasive, chronological evaluation of various experimental interventions in a murine model of asthma.

Allergens↗
PubMed1997

Induction of urokinase-type plasminogen activator receptor by IL-1 beta.

Extensive tissue remodeling occurs in survivors of acute lung injury, leading to nearly normal histology and physiology in the majority of individuals, whereas others suffer significant impairment due to the development of pulmonary fibrosis. Alveolar epithelial cells play a central role in the repair process. They are strategically located to directly participate in the solubilization of intraalveolar fibrin deposits, and have the capacity to promote fibrinolysis. We have previously reported that interleukin-1 beta (IL-1 beta), an important inflammatory mediator in acute lung injury, upregulates urokinase-type plasminogen activator expression by human A549 cells (1). In this work, we show that IL-1 beta increases cell-surface plasmin generation, mediated in part by increased expression of urokinase receptor (u-PAR). Northern blot analyses demonstrated that IL-1 beta rapidly induces accumulation of u-PAR messenger RNA (mRNA) in a dose-dependent fashion, and that this effect is blocked by actinomycin. The IL-1 beta-mediated increase in u-PAR mRNA is inhibited by: (1) the relatively specific protein kinase C (PKC) inhibitors 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H7) and calphostin C; and (2) prolonged pretreatment of cells with phorbol myristate acetate (PMA), suggesting that PKC is an important component of the signaling pathway. Okadaic acid, an inhibitor of serine/threonine phosphatases, markedly potentiates the effect of IL-1 beta on u-PAR mRNA levels. In contrast, dexamethasone, in concentrations as low as 10(-8) M, completely blocks the IL-1 beta-mediated increase in u-PAR mRNA. Half-life experiments show that dexamethasone has no effect on u-PAR mRNA stability. Aldosterone, at concentrations in which it binds primarily to the mineralocorticoid receptor, has no effect on u-PAR expression, suggesting that the glucocorticoid effect is due to a transrepressive mechanism. In summary, IL-1 beta increases cell-surface plasmin generation in A549 cells by coordinately upregulating urokinase and u-PAR expression. Transcriptional activation of the u-PAR gene involves PKC-dependent mechanisms, and glucocorticoid suppression is probably due to interactions between the glucocorticoid receptor and another transcriptional activating system such as activator protein-1 (AP-1) and/or nuclear factor-kB (NF-kB).

Blotting, Northern↗
PubMed1996

Effects of preoperative radiation and chemotherapy on AgNOR counts in oral squamous cell carcinoma.

PURPOSE: This study evaluated the relationship between argyophilic nucleolar organizer regions (AgNORs) and the histologic effects of preoperative chemotherapy or external radiation on oral squamous cell carcinoma. PATIENTS AND METHODS: Thirty-three cases of oral squamous cell carcinoma that were treated with chemotherapy (pepleomycin or 5-FU) or 60Co external radiation were studied. Biopsies were done on the tumor sites before therapy and the number of AgNORs per nucleus was recorded. After therapy, the tumors were resected and the therapeutic effects were assessed histologically. RESULTS: The number of AgNORs per nucleus before therapy ranged from 4.7 to 12.45 (mean +/- SD, 8.71 +/- 2.26). As the number of AgNORs per nucleus increased, the histological effects of preoperative therapy were enhanced. It was 5.75 +/- 0.77 in cases with a poor histological effect of preoperative treatment, 8.03 +/- 1.85 in cases with a mild histological effect, 9.09 +/- 1.85 in the moderate histological effect group, and 10.46 +/- 1.56 in the excellent histological effect group. CONCLUSION: These results suggest that AgNORs could be used to predict the effects of preoperative radiation and chemotherapy on oral squamous cell carcinoma.

Biomarkers, Tumor↗
PubMed1996

[Characteristics of radiopharmaceutical delivered from 99mTc-DTPA in the technegas generator].

99mTc-DTPA aerosol permeates the alveolar membrane by an intercellular pathway. Measurement of the clearance rate of 99mTc-DTPA aerosol is useful for assessing injury of the lung epithelium. Pertechnegas (P-gas) is also used to assess epithelial permeability, but its clearance is too rapid to evaluate lung epithelial permeability. The aims of this study were first to generate 99mTc-DTPA fine aerosol (D-gas), second to characterize D-gas by radiochromatography and an in vivo study in the rat, and third to investigate the clinical significance of D-gas in comparison with 99mTc-DTPA aerosol and P-gas. We generated D-gas in a chamber with an atmosphere of 3% oxygen and 97% argon inside the Technegas Generator. The clearance half-time of D-gas was 19.8 +/- 4.0 min in eight normal non-smoker subjects, 12.0 +/- 2.8 min in four smoker subjects, and 31 +/- 11.2 min in three with idiopathic interstitial pneumonia (IIP). In radiochromatography, the development of D-gas was the same as that of P-gas and different from that of 99mTc-DTPA solution. In the in vivo study using a rat, the distribution of intravenously injected D-gas solution was the same as that of 99mTcO4-, but different from that of 99mTc-DTPA solution. These results suggest that 99mTc-DTPA separates to free 99mTcO4- in the chamber of the Technegas Generator and that D-gas behaves in the same manner as P-gas. In conclusion, D-gas has no clinical significance for the assessment of epithelial permeability.

Aerosols↗
PubMed1995

Effect of TFC-612, a 7-thia prostaglandin E1 derivative, on a peripheral arterial occlusive disease model in rats.

TFC-612, methyl 6-[((1R,2S,3R)-3-hydroxy-2-[(1E,3S,5R)-3-hydroxy-5- methyl-1-nonenyl)-5-oxocyclopentyl]-thio]-hexanoate, inhibited the progression of the lesion in a lauric acid-induced peripheral arterial occlusive model at 1.0 mg/kg p.o. or 1.0 microgram/rat/h s.c. in rats. Aspirin (32 mg/kg, p.o.), an anti-platelet drug, did not suppress the lesion growth. On the other hand, ketanserin (10 mg/kg, p.o.), a 5-HT2 antagonist, also inhibited the progression of the lesion. In vitro, TFC-612 inhibited rat platelet aggregation induced by collagen and ADP with IC50 values of 5.4 ng/mL and 9.5 ng/mL, respectively. Aspirin also inhibited collagen-induced aggregation with an IC50 value of 6.3 micrograms/mL, but not ADP-induced aggregation at 180 micrograms/mL. Ketanserin had no effect on either aggregation at 40 micrograms/mL. In ex vivo experiments, aspirin inhibited platelet aggregation induced by collagen at 10 and 32 mg/kg in rats. However, TFC-612 showed significant inhibition only at 10 mg/kg. TFC-612 and ketanserin increased dermal blood flow in the rat paw at 1.0 microgram/kg i.v. and 100 micrograms/kg i.v., respectively. Aspirin had no effect on blood flow at 3.2 mg/kg i.v. These results suggest that the improvement of microcirculation, in addition to anti-platelet action by TFC-612, contributes to its inhibitory effect in a peripheral arterial occlusive model in rats.

Alprostadil↗
PubMed1995

Age-related differential mRNA expression of T cell cytokines in NZB/NZW F1 mice.

The mRNA expression of interleukin (IL)-2, IL-2 receptor-alpha-chain (IL-2R alpha), IL-4 and interferon-gamma (IFN-gamma) in spleen cells from NZB/NZW F1) mice following the stimulation with concanavalin A (Con A) was examined by Northern blot analysis. Kinetic patterns of the mRNA expression after the stimulation were not different between 2-month-old and 6 to 8-month-old B/W F1 mice. However, relative mRNA expression of IL-2 to a cytoskeletal protein, alpha-Tubulin was lower in 6 to 8-month-old B/W F1 mice than in 2-month-old mice. Similar but not significant tendency was observed in IL-2R mRNA expression. In contrast, Relative IL-4 mRNA expression in 6 to 8-month-old B/W F1 mice was significantly higher than that in 2-month-old animals. On the other hand, no apparent change was observed in IFN-gamma mRNA expression. Flow cytometric analysis indicated that there was no apparent difference in proportion of L3T4 positive T cells in spleen cells from 2 and 6 to 8-month-old B/W F1 mice. These results suggest that mRNA expression of IL-2 and IL-4 differentially changes with aging in autoimmune B/W F1 mice.

Age Factors↗
PubMed1995

[A case of sarcoidosis with right pneumothorax and multiple cavities in both lung fields].

A 26-year-old man was admitted to our hospital for evaluation of cavitary lesions on his chest X-ray film. Chest CT and conventional tomograms showed multiple cavities in both lung fields, as well as hilar and mediastinal lymphadenopathy. He had uveitis and the laboratory data showed a high level of angiotensin converting enzyme in the serum. Histological findings of the specimen obtained by transbronchial lung biopsy showed non-caseating epithelioid cell granuloma, consistent with sarcoidosis. Corticosteroid therapy (prednisolone 40 mg/day) resulted in reduction of the cavitary lesions and the lymphadenopathy. Negative bacteriological studies and the clinical course strongly suggested primary cavitation, a relatively rare form of pulmonary parenchymal involvement in sarcoidosis.

Adult↗
PubMed1995

[Uptake of Tc-99m hexakis 2-methoxy isobutyl isonitrile in lung or mediastinal lesions by SPECT].

The uptake of Tc-99m hexakis 2-methoxy isobutyl isonitrile (99mTc-MIBI) was evaluated in 18 patients with various lung or mediastinal lesions by SPECT. The patients consisted of seven with lung cancers, three with lung cancers who were treated with chemotherapy and were disease free, and one each with malignant lymphoma, esophageal cancer, thyroid cancer involving the mediastinum, malignant thymoma, pneumonia, granuloma, sarcoidosis and neurinoma. SPECT imaging (30 min, 600 MBq) was performed after intravenous injection. Strong uptake of 99mTc-MIBI was noted in all malignant tumors except malignant lymphoma. The mean tumor to normal lung tissue uptake ratio (T/N ratio) was 2.26. The mean in lung cancer was 2.31. Slight accumulation was present in pneumonia and granuloma (mean T/N = 1.24). No accumulation was present in a case of non-Hodgkin's lymphoma and neurinoma. Moderate uptake was noted in one case of sarcoidosis (T/N = 1.46). No abnormal accumulation of 99mTc-MIBI was seen in post-therapeutic lung cancer. These results suggested that 99mTc-MIBI SPECT could be useful in differentiating between malignant and benign lesions.

Adult↗
PubMed1994

Accumulation of multiple T cell clonotypes in lungs of healthy individuals and patients with pulmonary sarcoidosis.

T cell accumulation and activation in lung may play a major role in the pathogenesis of immunologic lung diseases such as sarcoidosis. Using the combination of RT-PCR and subsequent single-strand conformation polymorphism analysis, we examined T cell clonality in lung and peripheral blood of healthy individuals (n = 5) and patients with active pulmonary sarcoidosis (n = 7). RNA was extracted from PBLs and bronchoalveolar lavage fluid cells, and converted to cDNA. PCR was performed using a set of V beta-C beta primers (V beta 1-20). Products were denatured and electrophoresed in nondenaturing 5% polyacrylamide gel. The existence of a distinct T cell clonotype was detected as a band on a smear. In both groups T cells in PBLs showed a number of clones that expanded. A significantly greater number of clones was detected in BAL compared with PBL in both groups (normal: 25.3 +/- 7.2 in PBL vs 62.8 +/- 5.2 in lung; sarcoid: 25.0 +/- 6.2 in PBL vs 90.0 +/- 6.6 in lung, mean value +/- SEM). In sarcoid lung greater numbers of clones were detected than in lungs of healthy controls (p < 0.012). These clonal expansions were observed over all the 20 V beta families examined, and were not restricted to certain V beta families. These results suggest that there are clonal expansions even in normal lung, and that in sarcoidosis, apparently, additional T cell clones using multiple V beta segments might be activated and accumulated at the site of the disease.

Adult↗
PubMed1993

The anti-platelet actions of FR122047, a novel cyclooxygenase inhibitor.

The anti-platelet actions of 1-[(4,5-bis(4-methoxyphenyl)-2- thiazoyl)carbonyl]-4-methylpiperazine hydrochloride (FR122047) were investigated in vitro and in vivo. FR122047 was 100 times more potent than aspirin against arachidonic acid- and collagen-induced human and guinea-pig platelet aggregation in vitro. Its actions on platelets were a result of cyclooxygenase inhibition. The single oral dose of FR122047 inhibited arachidonic acid- and collagen-induced aggregation with an ED50 of 280 micrograms/kg and 530 micrograms/kg, respectively, in guinea-pigs. The anti-platelet action was augmented 5-10 times by repeated administration for 4 days. At 1 mg/kg the inhibitory actions were prolonged for 48 h and the drug concentration was < 0.1 ng/ml in platelet-poor plasma at 24 h and 0.282 ng/ml in platelet-rich plasma at 48 h. The safety margin in rats (minimum ulcerogenic dose/ED50 for anti-platelet aggregation) of FR122047 was more than 70, while that of aspirin was only 1.2. These results indicate that FR122047 is concentrated in platelets and may be a useful anti-platelet agent.

Animals↗