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Biomedical subjects

Y Kawabe

Publications and source records attributed to Y Kawabe.

At least 73 records · Page 4Linked to original sources
PubMed1999

Expression of mitogen activated protein kinases in labial salivary glands of patients with Sjögren's syndrome.

OBJECTIVE: The expression of CD40 and CD40 ligand (CD40L) in mononuclear cells (MNCs) infiltrating the salivary glands of patients with Sjögren's syndrome (SS) has recently been reported. This study determined the expression of mitogen activated protein kinase (MAP kinase) superfamilies, which act as downstream effector molecules of CD40, in MNCs infiltrating labial salivary tissues in SS patients. METHODS: Six HTLV-I seronegative SS patients and 10 HTLV-I seropositive patients including five HTLV-I associated myelopathy (HAM) patients were examined. The expression of MAP kinase superfamilies in labial salivary glands was examined by immunohistochemistry containing the mirror section technique. RESULTS: Both active forms of c-Jun N-terminal kinase (JNK) and p38 were found in salivary infiltrating MNCs of SS patients. Only minimal expression of the active form of extracellular signal regulated kinase (ERK) was observed in these tissues, however, co-expression of active JNK and active p38 was confirmed by the mirror section technique. Furthermore, these protein kinases were co-expressed in CD40(+) MNCs. No difference in expression levels of active JNK and p38 was found in patients who were positive or negative for anti-HTLV-I antibody. CONCLUSION: These results indicate that JNK and p38, but not ERK, function as downstream effector molecules of CD40 in salivary infiltrating MNCs in SS patients, and suggest that these molecules may be involved in the pathological process of chronic sialadenitis in SS.

Adult↗
PubMed1999

Evaluation of a new anti-HCV-assay kit for anti-HCV screening in early childhood.

Sera of 20 children falsely identified as positive for hepatitis C virus antibody (Anti-HCV) by a second generation anti-HCV-assay kit (Imucheck-HCV Ab "Kokusai") were re-tested using a new third generation anti-HCV-assay kit (Imucheck x F-HCV C50 Ab "Kokusai"). Seventeen of the samples were reclassified as negative and only three remained positive. Changing well solids in the anti-HCV-assay kit from casein to bovine serum albumin appears to have improved the false-positive rate, most likely as a result of decreased non-specific adsorption of casein antibodies.

Animals↗
PubMed1999

Successful treatment of adult-onset Henoch-Schönlein purpura nephritis with high-dose immunoglobulins.

A 26-year-old woman was admitted for the evaluation of edema and massive proteinuria. She had a history of purpura of the lower extremities, abdominal pain and melena. Laboratory investigations showed hypoalbuminemia, hypercholesterolemia and proteinuria of over 10 g/day. Renal biopsy showed moderate proliferative glomerulonephritis with mesangial immunoglobulin A (IgA) deposition. She was diagnosed as having Henoch-Schonlein purpura nephritis. Oral prednisolone, dipyridamole and intravenous heparin treatment were not effective. Steroid pulse therapy induced a partial improvement of proteinuria to 2-3 g/day. High-dose intravenous immunoglobulin (i.v.-IG) treatment was introduced and a dramatic improvement of proteinuria was noted. I.v.-IG should be fully considered in patients with steroid-resistant Henoch-Schonlein purpura nephritis.

Adult↗
PubMed1999

Doppler spectral waveform analysis of arteries of the hand in patients with Raynaud's phenomenon as compared with healthy subjects.

OBJECTIVE: We sought to characterize and compare the blood flow patterns of peripheral arteries of the hand in patients with Raynaud's phenomenon and in healthy subjects. SUBJECTS AND METHODS: We used Doppler sonography to assess the blood flow pattern of the proper palmar digital artery and the deep radial arch in the hands of 79 healthy subjects and 24 patients with primary and secondary Raynaud's phenomenon. We determined the resistive index, pulsatility index, peak systolic velocity, and end-diastolic velocity of these peripheral arteries at rest and after cold immersion. RESULTS: The proper palmar digital artery of healthy subjects showed higher end-diastolic velocities and lower resistive indexes than did the deep radial arch. Compared with healthy subjects, patients with Raynaud's phenomenon had higher resistive and pulsatility indexes but lower peak systolic and end-diastolic velocities in these arteries. Accordingly, the differences in end-diastolic velocity and resistive index seen in the two peripheral arteries of healthy subjects were not seen in patients with Raynaud's phenomenon. Analysis of receiver operating characteristic curves showed high diagnostic accuracy in detecting the disease. Cold-immersion studies revealed that for the proper palmar digital arteries throughout the time after immersion, all these Doppler parameters were significantly lower for the velocities and higher for the indexes in patients with Raynaud's phenomenon than in healthy subjects. CONCLUSION: Taken together, these results suggest a legitimate role for Doppler sonography in the assessment of Raynaud's phenomenon.

Adult↗
PubMed1999

Expression of CD40/CD40 ligand and Bcl-2 family proteins in labial salivary glands of patients with Sjögren's syndrome.

Lymphocytes infiltrating the salivary glands of patients with Sjögren's syndrome (SS) are activated and resist apoptosis. We determined the role of interactions between CD40 and CD40 ligand (CD40L) in these infiltrating lymphocytes on B-cell differentiation and expression of Bcl-2 family proteins. Ten human T-cell leukemia/lymphoma virus-I (HTLV-I)-seronegative and eight HTLV-I-seropositive SS patients were examined in the present study. Immunohistochemistry was performed to examine the expression of CD3, CD20, PCA-1, CD40, CD40L, Bcl-2, Bax, and Bcl-x on T and B lymphocytes infiltrating labial salivary glands of SS patients. We also examined the expression of CD40 and CD40L on peripheral blood lymphocytes of the same patients by using flow cytometry. CD40L was not expressed on peripheral blood lymphocytes of SS patients. Peripheral blood B cells but not T cells expressed CD40. In contrast, >50% of mononuclear cells, including T and B cells infiltrating the glands, expressed CD40. In addition, a clear expression of CD40L in both infiltrating T cells and B cells, and that of PCA-1, was also demonstrated. Surprisingly, the expression of Bcl-2 and Bcl-x was colocalized with that of CD40 determined by mirror section technique. Bcl-x was also abundantly expressed on infiltrating mononuclear cells, but, Bax expression was relatively less than that of Bcl-2 or Bcl-x. The expression of the above molecules was not different between HTLV-I-seronegative and HTLV-I-seropositive SS patients. Our results indicate that CD40/CD40L pathways could be augmented in salivary glands of SS patients, inducing B-cell differentiation to PCA-1 + plasma cells. Immunohistochemical analysis also suggests that signaling through CD40 by means of CD40L increases the expression of Bcl-2 as well as Bcl-x in infiltrating lymphocytes, providing the resistance against apoptosis. Our findings were commonly observed in SS patients irrespective of HTLV-I seropositivity.

Aged↗
PubMed1999

[Active pulmonary tuberculosis in patients with lung cancer].

To clarify the features of the coexistence of active pulmonary tuberculosis in patients with lung cancer, we analyzed clinical data on 25 cases with coexisting lung cancer and active pulmonary tuberculosis encountered at Tokyo National Chest Hospital during the period from 1991 to 1998. There were 23 men and 2 women, with a mean age of 70 years. The incidence of lung cancer among patients with active pulmonary tuberculosis at our hospital was 0.7 per cent, while the incidence of active pulmonary tuberculosis in untreated lung cancer patients at our hospital was 1.9 per cent. We classified the 25 cases into 2 groups as follows: (1) tuberculosis sequential to lung cancer (11 cases) and (2) tuberculosis concurrently detected with lung cancer (14 cases). All patients in the former group were transferred from other hospitals after diagnosing the coexistence of pulmonary tuberculosis during the management of lung cancer. Histological types of lung cancer were squamous cell carcinoma in 12, adenocarcinoma in 9, and small cell carcinoma in 4, and as to the disease stage, stages III to IV were predominant. Analysis on relationship of chest X-ray findings between lung cancer and pulmonary tuberculosis revealed that in general, the location of lung cancer and tuberculosis seemed to be independent. Tuberculosis in the sequential group was more extensive and severer than in the concurrent group. In the concurrent group, treatment for tuberculosis was successful except for one case, and coexisting tuberculosis did not seem to affect the course of lung cancer among this group. However, in the sequential group, 5 patients died within 3 months, 2 of them died of tuberculosis. We consider that in the management of lung cancer, physicians should consider the possibility of coexistent active pulmonary tuberculosis and should not make delay in the diagnosis of active pulmonary tuberculosis.

Adenocarcinoma↗
PubMed1998

Antiatherogenic effects of the antioxidant BO-653 in three different animal models.

Antioxidants have been proposed to have antiatherogenic potential by their inhibition of low density lipoprotein (LDL) oxidation. Here, we report an antioxidant, BO-653 (2,3-dihydro-5-hydroxy-2, 2-dipentyl-4,6-di-tert-butylbenzofuran), designed to exhibit antioxidative potency comparable to that of alpha-tocopherol, but yet possess a high degree of lipophilicity comparable to that of probucol. BO-653 exhibits a high affinity for LDL and is well distributed in aortic vessels in vivo. In atherosclerosis models of rabbits and mice, BO-653 has been shown to be able to suppress the formation of atherosclerotic lesions without untoward side effects. Specifically, there was no reduction of high density lipoprotein levels. This antioxidant provides additional evidence in support of the oxidized-LDL hypothesis, and itself is a promising candidate antioxidant for clinical use.

Animals↗
PubMed1998

Insulin-like growth factor I stimulates proliferation and Fas-mediated apoptosis of human osteoblasts.

In vitro studies have shown that insulin-like growth factor I (IGF-I) is a potent growth factor for osteoblasts, although both bone formation and resorption are upregulated by IGF-I in vivo. To understand the difference in the action of IGF-I observed in vitro and in vivo experiments, we examined the effect of IGF-I on the proliferation and Fas-mediated apoptosis of human osteoblasts in vitro. Human osteoblastic cell line MG63 and human primary osteoblast-like cells obtained from biopsy specimens were used as human osteoblasts. Cells were cultured with or without various concentrations of IGF-I followed by determination of the proliferative response and Fas-mediated apoptosis. IGF-I dose dependently stimulated the proliferation of cultured human osteoblasts. Both Fas expression and the degree of anti-Fas IgM-induced apoptosis of human osteoblasts was also augmented by IGF-I. Furthermore, the cytotoxicity of Fas ligand (FasL) cDNA transformants against human osteoblasts was increased when IGF-I-stimulated osteoblasts were used as target cells, indicating that stimulation of IGF-I increased functional Fas expression on human osteoblasts as well as their proliferation. The addition of DEVD-CHO, a specific inhibitor of CPP32, to the culture resulted in a significant inhibition of Fas-mediated apoptosis of both unstimulated and IGF-I-stimulated osteoblasts, although it did not affect the proliferative response or Fas expression. Our data suggest that activation of CPP32 is necessary for Fas-mediated apoptosis of human osteoblasts, and treatment of IGF-I increased this signaling pathway. In contrast, regulation of proliferation and Fas expression of the cells were probably not affected by CPP32 activation. Our results suggest that IGF-I acts on cultured human osteoblasts by increasing their proliferation and induction of Fas-mediated apoptosis by neighbouring FasL+ cells such as osteoclasts, thus probably functioning as a local coupling factor in the bone in vivo, stimulating both bone formation and resorption.

Apoptosis↗
PubMed1998

Immunohistochemical evidence for a macrophage scavenger receptor in Mato cells and reactive microglia of ischemia and Alzheimer's disease.

Macrophage scavenger receptors (MSR) are implicated in the development of atherosclerosis and amyloid b-protein deposition in Alzheimer's disease. However, histopathological studies of MSR expression in human tissues have been hampered by a lack of specific antibodies. Using MSR-deficient mice, we successfully raised a novel monoclonal antibody against human MSR together with high-titer antisera. These antibodies specifically recognized human tissue macrophages and human MSR protein purified from differentiated THP1 cells. In normal brain, MSR staining was mainly distributed to the perivascular cells, which correspond to Mato's fluorescent granular perithelial cells (Mato cells). In the lesions of ischemia and Alzheimer's disease, a subset of microglia stained positive for MSR. These novel antibodies are useful tools for analysis of MSR expression in human tissues.

Alzheimer Disease↗
PubMed1998

Ovarian mixed germ cell tumor composed of polyembryoma and immature teratoma.

We report the case of a 41-year-old woman with ovarian mixed germ cell tumor which was composed of polyembryoma and immature teratoma and who had high serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). By immunohistochemical methods, AFP was found in yolk sac cells of the embryoid bodies and immature hepatoid tissues, and hCG was found in giant syncytiotrophoblastic cells. She was treated with surgery followed by cisplatin-based combination chemotherapy. She is well, and her serum levels of AFP and hCG have not been elevated for more than 4 years after the treatment.

Adult↗
PubMed1998

Expression and function of Fas and Fas ligand on peripheral blood lymphocytes in normal subjects.

We investigated the expression and function of Fas and Fas ligand (FasL) on peripheral blood lymphocytes (PBLs). The cells were stimulated with various cytokines or 12-0-tetradecanoyl phorbol 13-acetate (PMA) plus ionomycin. About 30% of unstimulated PBLs expressed Fas, and the expression was augmented by interleukin-1beta (IL-1beta), IL-2, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), or PMA plus ionomycin. Although only minimal FasL expression was detected on unstimulated PBLs, FasL expression was markedly induced by IL-2 or PMA plus ionomycin, suggesting that Fas and FasL were both expressed on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Although IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs were positive for both Fas and FasL, no significant increase in apoptosis was demonstrated in these activated PBLs. In addition, treatment of PBLs with IL-2 or PMA plus ionomycin did not change anti-Fas-induced apoptosis, although these activated PBLs expressed Fas strongly when compared with unstimulated PBLs. Only IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs killed Fas+ target cells efficiently via the interaction of Fas on target cells with FasL of PBLs. Bcl-2 was constitutively expressed on unstimulated PBLs, but its expression was significantly augmented by IL-2 or PMA plus ionomycin. The expression of Bax was clearly induced only on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs and that of other Bcl-2 family proteins such as Bcl-x and Bad could not be detected on human PBLs, including IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Our results suggest that PBLs activated by IL-2 or PMA plus ionomycin express both Fas and FasL and that they kill Fas+ target cells by using FasL on the surface. The resistance of these activated PBLs to Fas-mediated apoptosis may be due to the augmented Bcl-2 expression or the presence of Bcl-2:Bax heterodimers on these cells.

Adult↗
PubMed1998

Apoptosis induction in synovial fibroblasts by ceramide: in vitro and in vivo effects.

Several lipid second messengers are important mediators of extracellular signals. Among them ceramide, which is formed by cell membrane sphingomyelin, influences the apoptotic signal pathway through Fas antigen. We examined the apoptotic effect of cell-permeable C2-ceramide on rheumatoid synovial fibroblasts in vitro and in vivo. Exposure of cultured human rheumatoid synovial fibroblasts to C2-ceramide for 24 hours produced internucleosomal DNA fragmentation and morphologic changes characteristic of apoptosis. This C2-ceramide-mediated apoptosis was dose dependent as confirmed by analysis of cytosolic oligonucleosome-bound DNA of treated synovial fibroblasts. We also demonstrated that intra-articular administration of C2-ceramide into Fas-deficient MRL lpr/lpr mice produced a profound reduction of synovial hyperplasia within 24 hours. In situ nick end labeling analysis confirmed the induction of apoptosis in synovial lining cells. Our results indicate that C2-ceramide may function as a potent inducer of apoptosis in the synovium and suggest that pharmacologically-induced apoptosis may be useful as a new therapeutic modality for rheumatoid arthritis.

Animals↗
PubMed1998

Apoptosis in labial salivary glands from Sjögren's syndrome (SS) patients: comparison with human T lymphotropic virus-I (HTLV-I)-seronegative and -seropositive SS patients.

Apoptosis is a type of cell death that occurs during morphogenesis and development of the immune system. One of the mechanisms is mediated through the Fas and Fas ligand (FasL) pathway. To determine the possible involvement of Fas and its ligand in salivary gland destruction, we analysed the appearance of nuclei with DNA fragmentation by using nick end labelling (TUNEL) and the expression of Fas and FasL by immunohistochemistry in labial salivary glands. Furthermore, we compared the features of apoptosis in labial salivary glands between HTLV-I- and HTLV-I+ SS. When the frozen sections of 10 primary SS patients in the absence of anti-HTLV-I antibody were examined, several apoptotic cells were found in the acinar and ductal epithelial cells as well as infiltrated mononuclear cells. Both Fas and FasL were detected in the infiltrated mononuclear cells. Acinar epithelial cells, which are surrounded by FasL+ mononuclear cells, were also double-positive with Fas and FasL, although the expression of FasL was localized at their apical border, suggesting that apoptosis of mononuclear cells was achieved by activation-induced mechanisms through Fas/FasL pathways, and that of acinar epithelial cells was mediated by FasL derived from either acinar epithelial cells themselves or infiltrated mononuclear cells. Interestingly, Fas expression in ductal epithelial cells was localized around the lumen side of the ducts, indicating that FasL secreted from acinar epithelial cells may induce Fas-mediated apoptosis of ductal epithelial cells. We also studied the labial salivary glands from nine SS patients with anti-HTLV-I antibodies. There was no significant difference in the occurrence of apoptotic cells or in the expression of Fas and FasL between HTLV-I+ and HTLV-I- SS patients. It was of note that neither the expression of Fas and FasL nor the presence of apoptotic cells were determined in labial salivary glands from subjects without SS. These findings indicate that Fas-mediated apoptosis in salivary glands could be involved in the pathological manifestations of SS, irrespective of HTLV-I seropositivity.

Adult↗
PubMed1998

CD4+ T-cell-mediated cytotoxicity against staphylococcal enterotoxin B-pulsed synovial cells.

Apoptosis of synovial cells in rheumatoid arthritis (RA) synovium determined in vivo is suggested to counteract the overgrowth of synovium. Immunohistological examination has revealed the infiltration of activated CD4+ T cells, which express Fas ligand (FasL), in RA synovium. The presence of a putative antigen (Ag) of autoimmune disorders in a target organ may induce the activation of specific T cells in the inflammatory region such as RA synovium. We examined the possible role of CD4+ T cells activated by synovial cells in a staphylococcal enterotoxin B (SEB)-dependent manner, inducing synovial cell apoptosis. Synovial cells were cultured with or without interferon-gamma (IFN-gamma) and further incubated with CD4+ T cells in the presence of SEB. After the cocultivation, both the cytotoxicity and FasL expression of CD4+ T cells were investigated. Constitutive Fas expression was detected on both unstimulated and IFN-gamma-stimulated synovial cells. CD4+ T cells did not kill SEB-pulsed unstimulated synovial cells efficiently. In contrast, when CD4+ T cells were incubated with IFN-gamma-stimulated synovial cells with SEB whose human leucocyte antigen (HLA)-DR and -DQ expression was markedly induced, significant cytotoxicity by these cells against synovial cells was detected. The addition of anti-HLA-DR and -DQ monoclonal antibodies (mAbs) or human Fas chimeric protein (hFas-Fc) reduced this cytotoxicity. FasL expression of CD4+ T cells cocultured with IFN-gamma-stimulated synovial cells with SEB was significantly induced. Furthermore, the addition of mAbs against CD54, CD58 and CD106 inhibited both the cytotoxicity and FasL expression of CD4+ T cells induced by IFN-gamma-stimulated synovial cells in the presence of SEB, indicating the importance of costimulatory molecules on synovial cells in activating CD4+ T cells. Our results suggest that CD4+ T cells are activated by synovial cells by an SEB-dependent manner and express FasL, inducing Fas-mediated apoptosis of the latter cells. These phenomena may regulate the overgrowth of synovial cells in RA synovium.

Antibodies, Monoclonal↗
PubMed1998

Corticosteroid irrigation of parotid gland for treatment of xerostomia in patients with Sjögren's syndrome.

OBJECTIVE: To determine the efficacy of corticosteroid irrigation of the parotid gland in relieving salivary flow deficiency in patients with Sjögren's syndrome. METHODS: The parotid glands of 31 patients with primary (24) or secondary (seven) Sjögren's syndrome were irrigated either with saline solution followed by corticosteroid solution, or with saline solution alone. Salivary function was assessed by Saxon test. RESULTS: Corticosteroid irrigation significantly increased the salivary flow rate in patients with Sjögren's syndrome (p < 0.0001), with clinical improvement detectable 3.7 (2.4) weeks (mean (SD)) after initial corticosteroid irrigation. The extent of improvement in salivary function was reciprocal to the clinical severity of the disease, with patients at the early stages obtaining 1.20 (0.57) g net increase in salivary flow rate, and patients at the most advanced stages obtaining 0.20 (0.47) g net increase. Repeated corticosteroid irrigations did not evoke corticosteroid refractoriness of the salivary gland; similar levels of net increase in salivary flow rate were observed after the second to fourth challenge of the corticosteroid in these patients. The sustained period was 8.4 (3.5) months (mean (SD)). CONCLUSION: These findings suggest the clinical usefulness of corticosteroid irrigation therapy in relieving xerostomia in patients with Sjögren's syndrome.

Adult↗
PubMed1998

Characterization of two Chinese hamster ovary cell lines expressing the COOH-terminal domains of sterol regulatory element-binding protein (SREBP)-1.

Sterol regulatory element-binding proteins (SREBPs) regulate transcription of genes encoding enzymes in the cholesterol biosynthetic pathway and the LDL receptor. These proteins are synthesized as membrane-bound precursors and processed to generate the NH2-terminal domains, mature transcription factors. We established two Chinese hamster ovary (CHO) cell lines, CHO-421 expressing the truncated hamster SREBP-1 (amino acids 421-1133) with two transmenbrane domains and CHO-557 expressing another truncated SREBP-1 (amino acids 557-1133) without any transmembrane domains, to investigate the fate of the COOH terminus after cleavage of the NH2-terminal mature SREBP. The cell fractionation experiments revealed that the two proteins, regardless of the absence of transmembrane domains in the SREBP (557-1133), similarly localized in the nuclear envelope and the microsomal membrane fractions, suggesting that these proteins appear to be tightly bound to a membrane protein(s) localizing on the nuclear and endoplasmic reticulum (ER) membranes. Although we predicted that overexpression of the COOH-terminal domains, which were thought to be involved in the regulation of SREBP processing, would result in disruption of the SREBP-dependent transcriptional regulation of several genes, the mRNA levels for 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) synthase in these two cell lines were regulated in a sterol-dependent manner. Pulse-chase experiments revealed that the SREBP (421-1133) was relatively rapidly degraded (t1/2 = 4-6 hr) and that the intracellular cholesterol level did not affect the half-life time. The degradation of the SREBP (421-1133) was not suppressed by the treatment of a calpain inhibitor, N-acetyl-leucyl-leucyl-norleucynal (ALLN), which blocks the proteolysis of some proteins within or near the ER. In CHO-557 cells the SREBP (557-1133) was much more rapidly degraded (t1/2 = 1-2 hr), suggesting that the cytosolic COOH-terminal domain is accessible to the enzymatic attacks from the cytoplasm. Taken together, overexpression of the COOH-terminal domains does not affect the regulation of SREBP processing and the domains are rapidly turned over by the cytosolic proteolytic process distinct from the ALLN-sensitive ER degradative pathway.

Animals↗
PubMed1998

[An autopsy case of rheumatoid arthritis accompanied with acute exacerbation of interstitial pneumonia].

An autopsy case of rheumatoid arthritis (RA) with acute exacerbation of interstitial pneumonia is reported. A 57-year-old woman with longstanding RA was admitted to our hospital because of progressive dyspnea. On chest roentogenogram, diffuse interstitial shadow was confirmed in both lungs. Chest computed tomography (CT) showed diffuse lesion of elevated density of CT level in both lung. She was diagnosed as an acute exacerbation of interstitial pneumonia, and treated by methylpredonisolone pulse therapy (1,000 mg/day). Although cyclosporin A (2 mg/kg/day) was combined to steroid therapy, she was died of progressive respiratory failure. The histological findings of the lung showed extensive fibrosis with alveolar damage associated with hyaline membranes, edema and hemorrhage in alveolar space.

Acute Disease↗