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Biomedical subjects

K Chida

Publications and source records attributed to K Chida.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Immunoadsorption therapy for Fisher's syndrome: analysis of the recovery process of external ophthalmoplegia and the removal ability of anti-GQ1b antibodies].

The beneficial effect of plasma exchange, plasmapheresis or immunoadsorption therapy on Fisher's syndrome, suggested previously, has not been proved since no controlled studies have been conducted. In order to assess the effect of any treatment on Fisher's syndrome, simple and reasonable grading scales for evaluating the major neurological signs are needed. We tried immunoadsorption therapy in four patients with Fisher's syndrome, whose sera had anti-GQ1b antibodies. The clinical course was observed, with assessment of the severity of the major neurological signs based on grading scores; ranging from 0 to 30 for external ophthalmoplegia, from 0 to 10 for ataxia, and from 0 to 16 for areflexia. Tryptophan- or phenylalanine-linked polyvinyl alcohol gel column (TR-350, PH-350) was used as an adsorbent. In a patient who had IgG anti-GQ1b antibody and another patient who had both IgG and IgM anti-GQ1b antibodies, we compared the effectiveness of TR-350 and PH-350 to remove the anti-GQ1b antibody during the therapy. Two patients underwent immunoadsorption therapy at the height of clinical manifestations: in one patient, the therapy was discontinued because of critical hypotension and arrhythmia; the other was given only three sessions of therapy. The other two patients received six or seven sessions during the early recovering stage. All patients recovered without major neurological sequelae. Since ataxia was improved earlier than external ophthalmoplegia, the duration of hospitalization and the time of return to social life depended upon the recovery of external ophthalmoplegia. Analysis of the time course of external ophthalmoplegia score indicated that the improving period and the 50%-recovery day came earlier in the patients who were given a sufficient number of sessions than those who received an insufficient number of sessions. The treatment with TR-350 reduced the IgG anti-GQ1b antibody titer more than that with PH-350, but reduced the IgM anti-GQ1b antibody titer similarly. Immunoadsorption therapy using TR-350 has a probable beneficial effect on Fisher's syndrome even though it is carried out after the height of illness. The evaluation method for the severity of external ophthalmoplegia that we used in the present study is useful for assessing the effect of therapy on Fisher's syndrome.

Adult↗
PubMed1996

[Follicular bronchiolitis associated with rheumatoid arthritis].

A 52-year-old man with an 8-year history of rheumatoid arthritis was admitted to the hospital because of coughing and purulent sputum. A chest X-ray film obtained on admission showed small nodular shadows without overinflation in both lower lung fields, and a high-resolution CT scan showed many micronodular shadows in the centrilobular regions. Follicular bronchiolitis was diagnosed from the results of an open-lung biopsy, and prednisolone therapy was started at a dosage of 40 mg/day. Sinusitis developed 4 years later. Five years after the start of steroid therapy, dilation of bronchi and thickening of bronchial walls appeared on a CT scan, which also showed areas of low attenuation that were presumed to be bronchiolitis obliterans. These findings suggest that the pattern of airway disease can vary during the course of rheumatoid arthritis.

Anti-Inflammatory Agents↗
PubMed1995

The SH2 domain of Shc suppresses EGF-induced mitogenesis in a dominant negative manner.

Recently, we have shown that an EGF-R-mutant lacking the autophosphorylation sites phosphorylates Shc and retains mitogenic activity. In this report, we have shown that in these cells, in response to EGF, Ras is fully activated with formation of the tyrosine-phosphorylated Shc-Grb2-mSOS complex without the receptor. This pointed out the importance of Shc in EGF-induced Ras activation. To investigate the mechanism of tyrosine phosphorylation of Shc by EGF-R, we carried out in vitro kinase assays using immunoprecipitated EGF-R and bacterially-expressed Shc proteins as substrates. The EGF-R phosphorylated Shc, but not the Shc SH2 mutant, lacking binding ability for phosphotyrosine. This suggests that intact Shc SH2 is essential for the full-length Shc to become phosphorylated, probably by inducing a conformational change in Shc. Thus a Shc SH2 peptide may inhibit competitively Shc phosphorylation. We microinjected the Shc SH2 domain into NIH3T3 cells overexpressing the EGF-R. Microinjected Shc SH2 greatly suppressed EGF-induced DNA synthesis. But microinjection of neither the Shc SH2 mutant nor PLC-gamma 1 SH2 had any effect. This suppressing effect was rescued by comicroinjection of the full-length Shc, suggesting Shc SH2 specifically suppressed the Shc pathway. Thus we concluded Shc phosphorylation is crucial, whereas receptor autophosphorylation is dispensable, in EGF-induced mitogenesis.

3T3 Cells↗
PubMed1995

Cholesterol sulfate, a second messenger for the eta isoform of protein kinase C, inhibits promotional phase in mouse skin carcinogenesis.

Cholesterol sulfate is a second messenger for the eta isoform of protein kinase C mediating squamous differentiation. We found that cholesterol sulfate inhibited the promotional phase of skin carcinogenesis in female CD-1 mice, which was initiated by 100 micrograms 7,12-dimethylbenz[a]-anthracene and promoted by a single application of 10 micrograms 12-O-tetradecanoylphorbol-13-acetate, followed by repeated applications of 10 micrograms mezerein once a week for 19 weeks. Cholesterol sulfate, when applied topically at a dose of 400 micrograms (820 mumol) 10 min before treatment with the promoters, markedly suppressed tumor formation, resulting in decrease of 56% in the incidence of tumor-bearing mice, 81% in the number of tumors/mouse, and 60% in the size of tumors at 20 weeks of the promotion. This inhibition was not due to elimination of the initiated cells. Treatment with the parental cholesterol at a dose of 320 micrograms (820 mumol), which does not activate the eta isoform, did not inhibit tumor promotion. Repeated treatment with cholesterol sulfate induced scaling of skin at the site of application. Cholesterol sulfate, unlike most inhibitors of tumor promotion, did not inhibit induction of ornithine decarboxylase and hyperplasia in mouse epidermis caused by topical treatment with 12-O-tetradecanoylphorbol-13-acetate. These findings suggest that cholesterol sulfate inhibits tumor promotion by stimulating a differentiation pathway mediated by the eta isoform of protein kinase C.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1995

Effects of chemical stimulation of the rostral and caudal ventrolateral medulla on cerebral and renal microcirculation in rats.

We investigated the effects of neurons in the rostral and caudal ventrolateral medulla (RVL and CVL) on cerebral and renal microcirculation in rats. Rats were anesthetized with chloralose, paralyzed with tubocurarine, and artificially ventilated. Cerebral and renal blood flows (CBF and RBF) were measured simultaneously using laser-Doppler flowmetry. Chemical stimulation of the RVL neurons by microinjection of the excitatory amino acid L-glutamate increased arterial pressure (AP), whereas that of the CVL neurons decreased AP. Stimulation of the RVL neurons also elicited a stimulus-locked increase in CBF and a decrease in RBF. The percent change in CBF and RBF was dose-dependent as stimulus intensity was increased. Cerebral and renal vascular resistance (CVR and RVR) levels were calculated from changes in CBF or RBF and changes in mean AP. The percent reduction in CVR and percent elevation in RVR were also dose-dependent. Chemical stimulation of the CVL neurons elicited a stimulus-locked decrease in CBF and an increase in RBF. The percent reduction in CBF and percent elevation in CVR were dose-dependent. The percent reduction in RVR was also dose-dependent, while the percent elevation in RBF was not significant. Blood withdrawal reduced AP by a similar degree to CVL stimulation, but did not significantly decrease CBF. The results suggest that RVL and CVL neurons integrate cerebral and systemic microcirculation.

Animals↗
PubMed1995

Induction of MHC class II antigens on rat bronchial epithelial cells by interferon-gamma and its effect on antigen presentation.

Recent studies have found aberrant expression of class II antigens by bronchial epithelial cells (BECs), suggesting that these cells may also be involved in airway mucosal immunity. However, the regulation of class II antigen expression on BECs by cytokines and the functional capacity of such cells bearing class II molecules remain unknown. We investigated the effect of IFN-gamma on class II antigen expression by cultured rat BECs, as well as the ability of these cells to present intact protein antigens to specifically sensitized T cells. Although primary BECs did not express class II antigens, IFN-gamma readily induced their expression in a dose-dependent manner. More than 85% of the BECs treated with 1000 U/ml of IFN-gamma were positive for class II antigens. In addition, when IFN-treated BECs bearing class II molecules were pulsed with ovalbumin (OVA), they significantly stimulated the proliferation of OVA-sensitized T cells, whereas cells that were not treated with IFN-gamma but were pulsed with OVA did not do so. Our findings indicate that BECs bearing class II molecules are capable of presenting OVA to OVA-sensitized T cells. These results suggest that various pathological conditions causing the local production of IFN-gamma may increase class II antigen expression on BECs, which in turn may modulate the airway mucosal immune response by the presentation of antigens to T cells.

Animals↗
PubMed1995

Clinicopathologic characteristics of elderly patients with persistent ST segment elevation and inverted T waves: evidence of insidious or healed myocarditis?

OBJECTIVES: We sought to clarify the clinicopathologic characteristics of insidious or healed myocarditis in the elderly. BACKGROUND: Myocarditis is the cause of unexplained congestive heart failure and dilated cardiomyopathy. However, acute myocarditis of the Fiedler type is rare, and the incidence and implication of insidious or healed myocarditis in the elderly are not yet known. METHODS: In an autopsy study of 3,000 patients aged > or = 60 years, there were 12 (0.4%) with insidious or healed myocarditis, showing extensive and circumferential fibrosis and scattered lymphocytic infiltration of both ventricular walls without acute necrosis of the myocardial fibers. RESULTS: Unexplained congestive heart failure was found in seven cases. In all cases, electrocardiography had demonstrated upward elevation of the ST segment and inverted T waves for durations ranging from 1 month to 12.7 years (mean 5.7 years). Mean (+/- SD) heart weight was 338 +/- 81 g (range 220 to 470). In nine cases, fibrous lesions, which were scattered but extensive and circumferential, were located in the subepicardial and middle layers of the left ventricle. In the remaining three cases, the fibrous lesions were located predominantly in the subepicardial and middle layers, but the subendocardial layer was also locally involved. Fibrous lesions of the right ventricle were predominant in the subepicardial layer and involved the subendocardial layer in four cases. Scattered lymphocytic infiltration was found in the fibrous lesions. CONCLUSIONS: In more than half of the aged cases with insidious or healed myocarditis, unexplained congestive heart failure was also present. Fibrous lesions due to myocarditis were located predominantly in the subepicardial and middle layers and led to persistent upward elevation of the ST segment and inverted T waves.

Aged↗
PubMed1995

The cell cycle-dependent nuclear import of v-Jun is regulated by phosphorylation of a serine adjacent to the nuclear localization signal.

Cell cycle-dependent phosphorylation and nuclear import of the tumorigenic transcription factor viral Jun (v-Jun) were investigated in chicken embryo fibroblasts. Nuclear accumulation of v-Jun but not of cellular Jun (c-Jun) is cell cycle dependent, decreasing in G1 and increasing in G2. The cell cycle-dependent regulation of v-Jun was mapped to a single serine residue at position 248 (Ser248), adjacent to the nuclear localization signal (NLS). Ser248 of v-Jun represents an amino acid substitution, replacing cysteine of c-Jun. It was shown by peptidase digestion and immunoprecipitation with antibody to the NLS that v-Jun is phosphorylated at Ser248 in the cytoplasm but not in the nucleus. This phosphorylation is high in G1 and low in G2. Nuclear accumulation of v-Jun is correlated with underphosphorylation at Ser248. The regulation of nuclear import by phosphorylation was also examined using NLS peptides with Ser248 of v-Jun. Phosphorylation of the serine inhibited nuclear import mediated by the NLS peptide in vivo and in vitro. The protein kinase inhibitors staurosporine and H7 stimulated but the phosphatase inhibitor okadaic acid inhibited nuclear import mediated by the NLS peptide. The cytosolic activity of protein kinases phosphorylating Ser248 increased in G0 and decreased during cell cycle progression, reaching a minimum in G2, whereas phosphatase activity dephosphorylating Ser248 was not changed. These results show that nuclear import of v-Jun is negatively regulated by phosphorylation at Ser248 in the cytoplasm in a cell cycle-dependent manner.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Enhanced migration of fibroblasts derived from lungs with fibrotic lesions.

BACKGROUND: The migration and proliferation of fibroblasts may be important in the pathogenesis of pulmonary fibrosis. Considerable data are available on the proliferation of fibroblasts, but very few on their migration. METHODS: The migratory activity of fibroblasts obtained from lung biopsy specimens from 11 patients with idiopathic pulmonary fibrosis (IPF) was studied using a 96-well chemotaxis chamber. Fibroblasts from eight normal controls, seven patients with interstitial fibrosis associated with a collagen vascular disease (IP-CVD), and 13 patients with sarcoidosis were also examined. Migratory activity was tested in a serum-free medium in the presence and absence of platelet derived growth factor (PDGF), 30 ng/ml, as a chemoattractant. RESULTS: Migration of fibroblasts from patients with IPF was enhanced in serum-free maintenance medium alone (mean (SD) controls v IPF: 183 (86) v 689 (491) cells/field), and was also enhanced when cells were stimulated by PDGF (controls v IPF: 829 (222) v 1928 (600) cells/field). Fibroblasts from tissues with dense fibrosis had a greater capacity for migration than those from an earlier stage of fibrosis. No correlation was found between migratory activity and proliferative capacity of the individual cells. CONCLUSIONS: The fact that fibroblasts from fibrotic lungs migrate faster than those from controls suggests that migration is related to the initiation of the pulmonary fibrotic process. These in vitro studies suggest that fibroblasts derived from the lungs of patients with pulmonary fibrosis have a migratory phenotype. Such a change in fibroblast phenotype, if it occurred in vivo, may be important in the context of the pathogenesis of pulmonary fibrosis.

Adult↗
PubMed1995

The influence of ovarian hormones on the granulomatous inflammatory process in the rat lung.

This study was initiated to clarify the relationship between ovarian hormones and the granulomatous inflammatory process in the lung. To assess whether ovarian dysfunction influences the granulomatous inflammatory process, we compared immunological alterations in ovariectomized rats and in sham-operated rats. After a heat-killed, bacilli Calmette-Guérin (BCG)-elicited granulomatous reaction, the lung-body weight ratios, the number of lymphocytes and activated T-cells, and the interferon-gamma levels in the bronchoalveolar lavage fluid from the ovariectomized rats were significantly higher than those of the sham-operated rats. Moreover, exogenous ovarian steroids supplemented in vivo suppressed not only the granulomatous inflammatory process in the lungs, but also the parameters measured in the bronchoalveolar fluid. These results indicate that ovarian dysfunction may adversely affect the formation of granulomas in the lung.

Animals↗
PubMed1995

An autopsy case of incomplete left atrial rupture following left atrial infarction associated with left ventricular myocardial infarction.

We report a 78-year-old woman with incomplete left atrial rupture following left atrial infarction associated with left ventricular myocardial infarction. An autopsy revealed a hemopericardium. A large hematoma was observed in the posterior wall of the left atrium and a few small tears were found on the same wall. Near its origin, the left circumflex artery was severely sclerotic and completely occluded by fresh thrombus. Histologic examination revealed that large intramural hematoma longitudinally dissected the inner third of the posterior wall of the left atrium, and transversely dissected through the necrotic tissue to the pericardial sac to result in rupture. Coagulation necrosis and intramyocardial hemorrhage were also observed throughout the entire left atrium and the postseptolateral wall of the left ventricle.

Aged↗
PubMed1995

Diagnostic and prognostic value of myocardial scintigraphy with thallium-201 and gallium-67 in cardiac sarcoidosis.

STUDY OBJECTIVE: To examine the diagnostic and prognostic value of myocardial scintigraphy using thallium-201 and gallium-67 in cardiac sarcoidosis. PATIENTS: Twenty-five patients with sarcoidosis. METHODS: All patients underwent myocardial thallium-201 scintigraphy. Six patients with myocardial thallium-201 defects were classified into group A and another 19 without defects were classified into group B. Between group A and B, we compared the results of other noninvasive examinations, including standard 12-lead ECG, 24 h ambulatory ECG, chest radiography, measurements of serum angiotensin-converting enzyme (ACE) and lysozyme levels, and gallium-67 scintigraphy. RESULTS: Proportions of subjects who had varying degrees of heart block, severe ventricular arrhythmias (more than or equal to third grade of Lown's classification), and high levels of serum ACE and lysozyme levels were not different between these two groups (p > 0.05). Although an enlarged cardiothoracic ratio was more frequent in group A (p < 0.05), bilateral hilar lymphadenopathy was more frequent in group B (p < 0.01). Four patients of group A and 15 of group B underwent gallium-67 scintigraphy. Although no subjects of group B had myocardial uptake of gallium-67, two of four group A patients showed cardiac uptake. These four group A patients were treated with corticosteroids. The therapy provided clinical and scintigraphic improvement in two patients with myocardial gallium-67 uptake, although it did no improvement in the other two patients without gallium-67 uptake. CONCLUSIONS: When cardiac sarcoidosis was diagnosed according to myocardial thallium-201 defects, other noninvasive examinations were not useful to detect this disease. However, gallium-67 uptake may predict the efficacy of corticosteroids. Thus, the combination of thallium-201 and gallium-67 scintigraphy may be useful not only in diagnosis of cardiac sarcoidosis but also in prediction of effects of corticosteroids.

Adrenal Cortex Hormones↗
PubMed1995

Hypersensitivity pneumonitis associated with home ultrasonic humidifiers.

We describe five patients with hypersensitivity pneumonitis (HP) that was related to using home ultrasonic humidifiers. All patients had micronodular infiltrates on their chest radiograph, and their lung biopsy specimens revealed alveolitis with or without epithelioid cell granulomas. Challenge tests were performed on two patients with the humidifier water and three patients using the humidifier. All patients tested exhibited a positive response. Tests for precipitating antibodies against an extract of the humidifier water gave strongly positive reactions in all patients tested. Precipitins to Cephalosporium acremonium and Candida albicans were also present in all cases, whereas precipitins to thermophilic actinomycetes were not detected. Although cultures of the water grew a variety of fungal and bacterial organisms, thermophilic actinomycetes could not be detected. These findings suggest that thermophilic organisms may not be the causative antigens of HP associated with ultrasonic humidifiers. All five patients had an increase in the bronchoalveolar lavage (BAL) lymphocytes that were predominantly CD4+ lymphocytes. The T helper cell count (CD4) to suppressor T cell count (CD8) ratio was significantly higher than that observed in summer-type HP, and lower than that observed in bird fancier's lung, indicating that the phenotypes of the BAL lymphocytes may vary with the type of HP.

Adolescent↗
PubMed1995

Effect of 14-membered ring macrolide therapy on chronic respiratory tract infections and polymorphonuclear leukocyte activity.

We studied the efficacy of the long-term administration of 14-membered ring macrolides in treating patients with diffuse panbronchiolitis (DPB) (34 patients) and bronchiectasis (BE) (40 patients). Oral administration of erythromycin (400 or 600 mg), roxithromycin (150 or 300 mg) or clarithromycin (200 or 400 mg) given daily for at least 2 months, was evaluated. The efficacy of erythromycin, roxithromycin, and clarithromycin in DPB was 19/24 (79%), 6/7 (86%), and 2/3 (67%), respectively. Efficacy of these agents in BE exceeded 50%. We determined the effect of these macrolides on the activity of polymophonuclear leukocytes (PMNs) obtained from healthy volunteers. There were no significant differences between the effects of these 14-membered ring macrolides and josamycin, a 16-membered ring macrolide which was previously found to be ineffective in treating DPB. Thus, the effectiveness of the 14-membered ring macrolides in treating DPB appears to depend on mechanism(s) other than alterations in PMN activity.

Adult↗
PubMed1995

Enzyme cytochemical study of alkaline phosphatase in rat hepatocytes--change of location after colchicine administration or bile duct ligation.

Changes in location of alkaline phosphatase (ALP) in rat hepatocytes after two different treatments were examined by the enzyme cytochemical technique. Although reaction deposits which indicate ALP activity were observed mainly in the bile canalicular membranes until 6 hr after colchicine administration, they were present not only in the bile canalicular membranes but also in the sinusoidal and lateral membranes 12 hr after drug administration. Eighteen and 24 hr after colchicine administration, a large number of reaction deposits were seen in the sinusoidal membranes and in the mutual membranes between adjacent hepatocytes, where the bile canaliculi were completely deformed and complex interdigitations appeared. On the other hand, after bile duct ligation, reaction deposits appeared in every domain of the plasma membranes. Twenty-four hr after colchicine administration to bile-duct-ligated rats, an increase in the number of the reaction deposits was observed, but the location of ALP remained unchanged. The present study suggests that intracellular transport and location of ALP in hepatocytes may be controlled by a common mechanism in colchicine-treated and bile-duct-ligated rats.

Alkaline Phosphatase↗