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Biomedical subjects

K Dobashi

Publications and source records attributed to K Dobashi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Postmenopausal hormone replacement therapy use and risk of endometrial cancer in Japanese women.

The relationship between the risk of endometrial cancer and the use of noncontraceptive estrogens by Japanese postmenopausal women was investigated in a hospital-based case-control study of 1025 women with endometrial cancer and 1267 with other conditions. The overall odds ratio (OR) for estrogen use with or without progestins, compared with never use of any type of estrogens, was 0.917 (95% confidence interval (CI) 0.622-1.353), suggesting that hormone replacement therapy is not a causative agent for endometrial cancer in Japanese women, and that a recent increase in the incidence of endometrial cancer in Japanese women may be related to changes in their life-style. However, although not statistically significant, women who used estrogen without progestin for 12 or more months had an OR of 2.552 (CI 0.231-28.192), while those who used estrogen with progestin for 12 or more months had an OR of 0.425 (CI 0.086-2.113). These results indicate that the addition of a progestin should be considered for reducing the risk of endometrial cancer in Japanese women.

Asian People↗
PubMed2000

Over-expression of p27kip1 induces growth arrest and apoptosis mediated by changes of pRb expression in lung cancer cell lines.

p27kip1 is a cyclin-dependent kinase inhibitor which controls the G1 phase of the cell cycle in conjunction with pRb. p27 has been associated with cell-cycle arrest and apoptosis. In this study, we transferred the full-length human p27 cDNA using a replication-deficient recombinant adenoviral vector (Ax-p27) into lung cancer cell lines and evaluated the potential of this strategy for anti-cancer gene therapy. After infection with Ax-p27, the growth of H322, A549 and SQ-5 cells, which express pRb, was almost completely suppressed, though no such effect was found in H69 and Lu-135 cells, which do not express pRb. In addition, cell death from day 4 after infection with Ax-p27 was observed only in H322, A549 and SQ-5 cells but not in H69 and Lu-135 cells. The cell cycle of H322 cells treated with Ax-p27 became arrested at the G1 phase from day 1 to day 3 despite continued over-expression of p27. When we examined the changes in expression level of pRb and E2F-1, which play important roles in cell-cycle progression from G1 to S phase, down-regulation of pRb expression was detected in H322 cells 3 days after infection with Ax-p27. These data suggest that (i) the growth-inhibitory effect and induction of apoptosis by over-expression of p27 require expression of pRb and (ii) adenovirus-mediated p27 gene transfer may have promise as a novel strategy in cancer gene therapy.

Apoptosis↗
PubMed2000

Evaluation of Y-27632, a rho-kinase inhibitor, as a bronchodilator in guinea pigs.

To evaluate (+)-(R)-trans-4-(l-Aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride, monohydrate (Y-27632), a selective Rho-kinase inhibitor, as a novel bronchodilator in vivo and in vitro, we investigated the effect of Y-27632 on the acetylcholine- or ovalbumin-induced increase in lung resistance (R(L)) in non-sensitized or passively sensitized guinea pigs, and the relaxant effects of salbutamol, Y-27632 and theophylline on acetylcholine- or ovalbumin-induced contraction of isolated trachea. Y-27632 inhalation (1 mM, 2 min) inhibited acetylcholine- or ovalbumin-induced increase in R(L) without changes in mean blood pressure, and the effect persisted for at least 3 h. Salbutamol, Y-27632 and theophylline each completely reversed the acetylcholine- or ovalbumin-induced contraction of isolated trachea with rank order of potency, salbutamol>Y-27632>theophylline. The relaxant effect of Y-27632 was not affected by propranolol. We conclude that, although Y-27632 is not as potent as a beta-adrenoceptor agonist, Y-27632 may become an alternative inhaled bronchodilator, because Y-27632 is more potent than theophylline, and the relaxant effect is independent of beta-adrenoceptors.

Acetylcholine↗
PubMed2000

Troglitazone inhibits the expression of inducible nitric oxide synthase in adipocytes in vitro and in vivo study in 3T3-L1 cells and Otsuka Long-Evans Tokushima Fatty rats.

The aim of this study was to determine the mechanism of troglitazone action on nitric oxide (NO) production via inducible NO synthase (iNOS) in adipocytes in vitro and in vivo. The treatment of 3T3-L1 adipocytes with the combination of lipopolysaccharide (LPS), tumor necrosis factor-alpha and interferon-gamma synergistically induced de novo iNOS expression leading to enhanced NO production. The NO production was inhibited by co-treatment with aminoguanidine or N-nitro-L-arginine methylester hydrochloride. Troglitazone inhibited the NO production in a dose dependent manner by the suppression of iNOS expression. In the 24 week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, the mean weight and the blood glucose were 21% and 30%, respectively, higher than in their lean counterparts. The serum nitrite concentration was increased after injection of LPS (4 mg/kg, i.p.), more markedly in OLETF rats than in the lean rats. The epididymal fats from LPS-injected groups, but not the ones from the non-injected groups, expressed mRNA and protein of iNOS. Troglitazone pre-treatment blocked the LPS-induced expression of iNOS in adipose tissue and the increase in serum nitrite concentration. These results suggest that troglitazone inhibits the cytokine-induced NO production in adipocytes by blocking iNOS expression both in vitro and in vivo.

3T3 Cells↗
PubMed2000

Mycobacterium avium complex pleuritis accompanied by diabetes mellitus.

A 72-year-old woman with diabetic nephropathy was hospitalized with peripheral edema in the extremities and weight increase. After diuretics and human serum albumin administration, her condition improved. From the 15th day she had run a subfever and her breathing was diminished in the left lower lung field. A plain chest X-ray film showed pleural effusion over the left lung field. The fluid was exudative. Fluid cultures were negative. A tuberculin reaction was negative. Polymerase chain reaction method disclosed mycobacterium avium complex, indicating rare pleuritis due to mycobacterium avium complex. Eighteen days after chemotherapy, pleural effusion disappeared. Although her hemoglobin A1c (HbA1c) levels were maintained from 6.0 to 6.5% over 4 years, urinary albumin excretion levels and serum creatinine levels increased, indicating deteriorating diabetic nephropathy. Serum albumin levels remained low (3.3-3.6 g/dl). Malnutrition, impaired cellular immunity and apparently abnormal microvascular circulation due to diabetes mellitus may consequently have induced pleuritis due to mycobacterium avium complex.

Aged↗
PubMed2000

Bone metastasis after a resection of stage I and II primary lung cancer.

In the present study, we reviewed the patients who developed bone metastases after a surgical resection of primary lung cancer and evaluated their clinicopathological features. From 1992 to 1995, 177 patients with stage I and II primary lung cancer underwent a surgical resection at the Kitakyushu Municipal Medical Center. Bone metastases were detected in 14 patients (7.9%) by follow-up examinations including bone scintigraphy (scan). Bone metastasis was one of the most frequent extra-thoracic recurrent forms. Patients with adenocarcinoma tended to develop bone metastases more frequently than those with squamous cell carcinoma. In the preoperative bone scans, an abnormal uptake was observed in 76 patients (42.9%), and 10 (13.1%) of them were found to develop bone metastases in the follow-up studies. A microscopic examination of the primary tumor demonstrated close correlation between intratumoral and peritumoral lymphatic vessel invasion and postoperative development of bone metastases. A bone scan is a very useful and indispensable procedure for diagnosing bone metastases. However, this scan may also show false positive finding in a number of benign conditions. Therefore, a surgical resection should be considered as the first-line treatment for patients with positive findings in the bone scan when the diagnosis of bone metastasis can not be confirmed based on both their symptoms and other clinical examinations.

Adenocarcinoma↗
PubMed2000

Kidney ischemia-reperfusion: modulation of antioxidant defenses.

Reactive oxygen species (ROS; O2-, H2O2, and OH), normal by-products of cellular metabolic processes, are kept in control by antioxidant enzymes, such as catalase, glutathione peroxidase (GPX) and superoxide dismutases (SODs). To understand the role of antioxidant enzymatic defenses against ROS injury following ischemia-reperfusion, we examined the effect on kidney exposed to varying periods (30, 60 or 90 min) of ischemia followed by different periods of reperfusion. The enzymatic activities and protein levels of catalase, GPX, CuZnSOD and MnSOD were relatively unaffected at 30 min of ischemia followed by 0, 2 or 24 h reperfusion. However, 60 or 90 min of ischemia followed by 0, 2 or 24 h of reperfusion resulted in a decrease in activities and protein levels which paralleled the duration of ischemic injury. MnSOD activity tended to recover towards normal during reperfusion. Examination of the mRNA levels of these antioxidant enzymes demonstrated a severe decrease in mRNA levels of catalase and GPX at a time point of minimal ischemic injury (30 min of ischemia followed by reperfusion) suggesting that loss of mRNA of catalase and GPX may be the first markers of alterations in cellular redox in ischemia-reperfusion injury. Greater loss of mRNA for catalase, GPX and CuZnSOD was observed following longer periods (60 or 90 min) of ischemia. The mRNA for MnSOD was upregulated at all time points of ischemia-reperfusion injury. Actually, the greater decrease in mRNAs for catalase, GPX and CuZnSOD in the acute phase (within 24 h) subsequently showed a further decrease in these enzyme activities in the subacute phase (72 or 120 h after ischemia). These enzyme activities in the 30 min ischemia group, (but not in the 90 min group), already showed tendencies for normalization at 120 h after ischemia. To understand the molecular basis of the loss of mRNA of these antioxidant enzymes during ischemia-reperfusion injury, we examined the rate of transcription by nuclear run-on assays. The similar rates of transcription in control and kidney exposed to ischemia-reperfusion indicates that the loss of mRNA for catalase, GPX and CuZnSOD is possibly due to the increased rate of turnover of their mRNAs. These studies suggest that expression of antioxidant genes during ischemia-reperfusion are not coordinately expressed and that the differential loss of antioxidant enzymes may be the contributing factor(s) towards the heterogeneous renal tissue damage as a result of ischemia-reperfusion induced oxidative stress.

Animals↗
PubMed2000

Critical value for the index of body fat distribution based on waist and hip circumferences and stature in obese girls.

OBJECTIVE: To determine the critical value for the standard deviation score (SDS) of waist-hip ratio (WHR)/height (Ht), as an age-adjusted measure of body fat distribution, in relation to occurrence of biochemical complications in obese girls. DESIGN: Cross-sectional, clinical study. The (WHR/Ht)-SDS was calculated as described previously. Obese girls were classified into two groups according to the occurrence of abnormal values in either serum triglyceride, alanine aminotransferase or insulin level. The criteria for obesity were subjected to the receiver operating characteristic (ROC) analysis. SUBJECTS: One-hundred and twenty-four outpatient Japanese obese girls, ranging in age from 9 to 15 y. MEASUREMENTS: Height, body weight, waist girth and hip girth as anthropometric measures. Percentage overweight, waist girth, WHR and (WHR/Ht)-SDS as criteria for obesity. Clinical laboratory analysis for fasting blood samples of obese children. RESULTS: Fifty-nine girls were classified into the no complication group, and 65 girls into the complication group. Those with complications were older, more obese, and their waist girth and WHR were larger, than the girls without complications. The (WHR/Ht)-SDS was >2-fold higher and lipoprotein profile was more atherogenic in the complication group than in the no complication group. Among the four criteria of obesity, (WHR/Ht)-SDS gave the ROC curve skewed furthest into the top left corner of the diagram. Both sensitivity and specificity for (WHR/Ht)-SDS were >80% at the critical value of 2.00. The sensitivity for waist girth was as high as that for specificity for the rest of the criteria were <80%. CONCLUSION: Only (WHR/Ht)-SDS showed high enough sensitivity and specificity to predict metabolic derangement in the present obese girls. (WHR/Ht)-SDS can serve as the diagnostic criterion that classifies obesity in Japanese adolescent girls into two types.

Adipose Tissue↗
PubMed2000

Evidence of oxidative stress in asthma and COPD: potential inhibitory effect of theophylline.

To evaluate the potential inhibitory effect of theophylline on the pulmonary oxidative stress in asthma and chronic obstructive pulmonary disease (COPD), we concomitantly measured the blood levels of theophylline, a non-selective phosphodiesterase (PDE) inhibitor and lipid peroxides as an index of oxidative stress. The plasma levels of lipid peroxides were significantly elevated in patients with asthma (3.48 +/- 0.11 nmol ml(-1); mean +/- SEM; n=21, P<0.01), non- or ex-smoking patients with COPD (3.55 +/- 0.11 nmol ml(-1); n = 20, P<0.01), and current-smoking patients with COPD (3.53 +/- 0.15 nmol ml(-1); n = 15, P<0.01), respectively, as compared to those of non-smoking controls (3.02 +/- 0.08 nmol ml(-1); n = 19). There was a significant negative correlation between the plasma level of lipid peroxides and the forced expiratory volume in 1 sec (FEV1)% of forced vital capacity in these subjects (r = -0.304; n = 75, P < 0.01). In asthmatics, there was a significant negative correlation between the plasma level of lipid peroxides and the serum level of theophylline (r = -0.495; n = 18, P<0.05). These results suggest that there may be increased oxidative stress in patients with asthma and COPD, and indicate that oxidative stress could possibly attribute to the pathophysiology of asthma and COPD in leading to airflow obstruction and that theophylline could potentially inhibit oxidative stress in the process of bronchopulmonary inflammation in asthmatics.

Aged↗
PubMed2000

Effects of N-acetylcysteine and ambroxol on the production of IL-12 and IL-10 in human alveolar macrophages.

BACKGROUND: N-acetylcysteine (NAC) and ambroxol (AMB) have recently been proposed as possible therapeutic agents in the treatment of pulmonary disorders. IL-12 plays an important role in host resistance to infection and the development of Th-1 cells. In contrast, IL-10 is involved in anti-inflammatory and immunoregulatory mechanisms. OBJECTIVE: We investigated the effects of NAC and AMB on secretions of IL-12 and IL-10 from human alveolar macrophages. METHODS: Alveolar macrophages were obtained from 7 healthy nonsmokers by bronchoalveolar lavage. The cells were first incubated with either NAC or AMB for 2 h and then cultured in lipopolysaccharide (LPS) solution for 24 h. IL-12 and IL-10 secretions were measured by ELISA. RESULT: Both NAC and AMB enhanced LPS-induced secretion of IL-12. NAC also enhanced LPS-induced IL-10 secretion, while AMB did not. The ratio IL-12/IL-10 secretion was increased by AMB, but NAC did not affect it. CONCLUSIONS: The results suggest that NAC enhances inflammatory and immune responses and prevents excessive responses reciprocally, through keeping local balance of IL-12 and IL-10 production in alveolar macrophages at inflammatory sites of bacterial pneumonia. AMB appears to strengthen inflammatory responses and cell-mediated immunity, facilitating the development of Th-1 cells, through shifting the local balance to IL-12 dominance.

Acetylcysteine↗
PubMed2000

[A case of pulmonary tuberculosis complicated with subcutaneous phaeohyphomycosis].

A 78-year-old male was admitted to our hospital because of fever, sputum and cough. Chest X-ray showed infiltrative shadows in the right lung field. Smears of his sputum were positive for acid-fast bacilli. We found multiple subcutaneous abscesses on the right distal forearm. Microscopic examination of skin biopsy specimens revealed granulation tissues with the proliferation of epitheloid cells with the scattering infiltrations of neurophils, giant cells and histiocytic cells. The examination of the PAS stained specimen revealed fungal elements and a black fungus, Exophiala jeanselmei, was isolated by the cultures of pus from the abscess. He was diagnosed as pulmonary tuberculosis complicated with subcutaneous phaeohyphomycosis caused by Exophiala jeanselmei and was successfully treated with anti-tuberculosis drugs and anti-fungal agent, 5-fluorocytosine.

Aged↗
PubMed2000

[The frequency profile of tuberculin skin testing among employees of a hospital].

The frequency profile of tuberculin skin testing among employees of a hospital was studied. In the analysis, tuberculin skin testing was defined as "negative" if skin rash is measured < or = 9 mm, and as "positive" if skin rash is measured > or = 10 mm, and as "strongly positive" if skin rash is measured > or = 10 mm, with induration, and double skin rash or bulla. Boosting was defined as initial skin rash was measured < or = 9 mm, with second skin rash measured > or = 10 mm and at least 6 mm increase of rash than the initial one. 544 employees were tested initially, and 81 were retested. Initial tuberculin positivity was associated with older age (p < 0.001); but boosting was not associated with age and occupation. Comparing pharmacists with other groups, the adjusted odds ratio of an initial strongly positive tuberculin reaction as significantly higher, namely 2.8 (95% confidence interval 1.2-6.7), but that of a booster reaction was 4.8 (0.7-32.1) which was insignificant.

Adult↗
PubMed2000

[A case of acute respiratory distress syndrome induced by fulminant influenza A (H3 N2) pneumonia].

We report a rare case of acute respiratory distress syndrome (ARDS) induced by Influenza A (H3 N2) without secondary microbiological infection. A 69-year-old woman was admitted to our hospital because of cough and severe dyspnea. We diagnosed ARDS, because of the severe respiratory failure resistant to high-dose oxygen, the diffuse bilateral infiltrates without cardiomegaly on chest radiography, and the normal pulmonary artery wedge pressure. This patient was treated with high doses of methylprednisolone, antibiotics, globulins, urinastatin, neutrophilic elastase inhibitor, nitric oxide inhalation, and extracorporeal membrane oxygenation, but died on the thirteenth hospital day. Our final diagnosis was ARDS induced by fulminant influenza (A/Hong Kong/68 (H3 N2)) virus pneumonia, because the antibody titers of H3 N2 influenza of paired sera showed a 128-fold increase.

Acute Disease↗
PubMed1999

Regulation by interleukin-1beta of gene expression of bradykinin B1 receptor in MH-S murine alveolar macrophage cell line.

The effects of recombinant murine interleukin (IL)-1beta on gene expression of murine bradykinin B1 receptor (BDKRB1) in MH-S murine alveolar macrophage cell line were evaluated. BDKRB1 mRNA expression in MH-S cells was increased by IL-1beta (1, 3, and 10 ng/ml) in a time-dependent manner, peaking at 3-4 h by 100-1000 fold. IL-1beta (5 ng/ml, 24h) also induced significant binding to [3H]-des-Arg10-kallidin with a dissociation constant (Kd) of 2.95 nM and a maximal binding density (Bmax) of 670 sites/cell. Des-Arg10-kallidin (10 microM), a BDKRB1 agonist, increased intracellular calcium ion ([Ca2+]i) in IL-1beta (5 ng/ml, 24 h)-exposed cells, an increase not observed in the cells not exposed to IL-1beta. A significant increase of tumor necrosis factor (TNF)-alpha secretion occurred in the IL-1beta (5 ng/ml, 24 h)-exposed cells following addition of des-Arg10-kallidin (the IL-1beta-exposed group: 57. 8 +/- 13.7 vs. the vehicle-exposed group: 16.7 +/- 4.3 pg/ml, p < 0.05 after a 100 nM des-Arg10-kallidin for 8 h), with an optimal effect at 3-100 nM. These data suggest that IL-1beta may up-regulate BDKRB1-mediated functions of alveolar macrophages via an induction of BDKRB1 gene expression.

Animals↗
PubMed1999

Effects of isoproterenol on IL-2 and cAMP production in peripheral T cells from asthmatic and non-asthmatic subjects sensitive to Candida.

Immunity to Candida albicans (Candida) is characterized by a Th-1 type pattern of reactivity. Candida is rarely a cause antigen for bronchial asthma. Beta agonists have been found to inhibit secretion of IL-2 from T cells through intracellular cAMP elevation. We examined effects of isoproterenol (ISO) on Candida-stimulated T cells. Peripheral T cells obtained from six Candida-sensitive asthmatics, six Candida-sensitive non-asthmatic subjects, and six normal donors by Ficoll-Hypaque gradient centrifugation and nylon-wool column chromatography were incubated with Candida antigen or concanavalin A (Con A) in the absence or presence of ISO. Secretion of IL-2 and intracellular accumulation of cAMP were assayed by ELISA. Con A induced secretion of IL-2 in each of the three groups. Candida antigen induced IL-2 secretion in the normal and the non-asthmatic subjects, but not in the asthmatics. ISO, which reduced Con A-induced secretion of IL-2 in a dose-dependent manner, had no effect on Candida-induced secretion of IL-2. Although ISO increased the intracellular concentration of cAMP in untreated and Con A-treated T cells from all donors, cells from the normal and the non-asthmatic subjects, but not from the asthmatics, that were co-incubated with ISO and Candida had lower levels of cAMP than those treated with ISO alone. It is suggested that Candida antigen induces secretion of IL-2 and reduces ISO-inducible accumulation of cAMP in Candida-responsive IL-2 secreting cells, which may make Candida-induced secretion of IL-2 insensitive to ISO.

Asthma↗
PubMed1999

Interferon-gamma rescues TNF-alpha-induced apoptosis mediated by up-regulation of TNFR2 on EoL-1 cells.

Recent studies show that apoptosis is important for the resolution of chronic inflammation. Using a human myeloblastic leukemia cell line, EoL-1, we investigated the effect of interferon-gamma (IFN-gamma), which differentiates EoL-1 into monocyte/macrophage-like cells on Fas antigen (Fas)- and tumor necrosis factor-alpha (TNF alpha)-induced apoptosis. Both TNF and anti-Fas monoclonal antibody (CH-11) induced apoptosis of EoL-1 cells. Pretreatment with IFN-gamma for 72 hours enhanced the CH-11-induced apoptosis with up-regulation of Fas. However, the treatment markedly inhibited the TNF-induced apoptosis. In flow cytometric analysis, EoL-1 expressed two types of tumor necrosis factor receptors (TNFR1 and TNFR2), and the expression of TNFR2 but not of TNFR1 was up-regulated significantly after the IFN-gamma treatment. The TNF-induced apoptosis was mimicked by a TNFR1 stimulating antibody (htr-9), and was reversed by a TNFR1 blocking antibody (H398). Although the TNFR1-mediated cytotoxic signal was not affected by IFN-gamma pretreatment, blocking TNFR2 by a specific antagonistic antibody (utr-1) canceled the inhibitory effect of IFN-gamma. In conclusion, TNF-induced apoptosis was mediated preferentially by TNFR1, and the anti-apoptotic effect of IFN-gamma was result from up-regulated TNFR2 in EoL-1 cell line. This cell line is a useful model to provide new insights into crosstalk among Fas/FasL-, TNF-, and IFN-gamma-mediated signaling.

Antibodies, Monoclonal↗
PubMed1999

Manganese superoxide dismutase in rat liver peroxisomes: biochemical and immunochemical evidence.

By using highly purified peroxisomes from rat liver, we have shown that peroxisomes contain manganese superoxide dismutase (MnSOD) activity and a 23 kDa protein immunoreactive with antibodies against purified mitochondrial MnSOD. Immunocytochemical studies have also revealed immunoreaction (immunogold) with MnSOD antibodies in mitochondria and peroxisomes. Studies of the intraperoxisomal localization of MnSOD have shown that in peroxisomes MnSOD is a component of the peroxisomal limiting membranes and dense core. Furthermore, the MnSOD level in peroxisomes was modulated by oxidative stress conditions such as ischemia-reperfusion or the treatment with ciprofibrate, a peroxisomal proliferator. These findings suggest that MnSOD in peroxisomes may play an important role in the dismutation of superoxide generated on the peroxisomal membrane for keeping the delicate balance of the redox state.

Animals↗