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Biomedical subjects

A Suwa

Publications and source records attributed to A Suwa.

At least 19 recordsLinked to original sources
PubMed2001

Cytokine and immunogenetic profiles in Japanese patients with adult Still's disease. Association with chronic articular disease.

OBJECTIVE: To determine cytokines and MHC class II alleles in Japanese patients with adult Still's disease (ASD) and clarify the association between those profiles and chronic articular disease. METHODS: Of 35 patients with ASD (13 men, 22 women, mean age at onset 34.0 yr), 17 (49%) had chronic arthritis (>6 months, chronic articular ASD) and 18 (51%) lacked chronic arthritis (systemic ASD). Cytokines and cytokine receptors in sera were measured by ELISA. Correlations of each cytokine with disease activity or C-reactive protein (CRP) were determined. MHC class II alleles were examined by polymerase chain reaction methods. RESULTS: In chronic articular ASD, female gender was more frequent and liver dysfunction and myalgia were rarer than in systemic ASD. In active disease, the white blood cell count was lower, but total IgG was greater in patients with chronic articular ASD than in those with systemic ASD. Tumour necrosis factor (TNF) alpha, soluble TNF receptor 2 and interleukin (IL)-18 were increased in both types of ASD, even in remission. Soluble IL-2 receptors, IL-4 and IL-18 levels were correlated with disease activity or CRP value only in chronic articular ASD. Interferon gamma and IL-8 remained increased only in chronic articular ASD, even when disease activity, including IL-6 and CRP, was low. DRB1*1501 (DR2) and DRB1*1201 (DR5) alleles were more frequent in chronic articular than in systemic ASD, whereas DQB1*0602 (DQ1) was frequently observed in both types of ASD. CONCLUSION: The present study suggests that ASD with chronic articular disease has distinct clinical, cytokine and immunogenetic profiles.

Adult↗
PubMed2000

[Hypersensitivity peumonitis in a patient with rheumatoid arthritis].

We report a case with rheumatoid arthritis and hypersensitivity pneumonitis. A 66-year-old female was admitted to our hospital because of fever, cough, and progressive dyspnea on October 10, 1997. She had a history of rheumatoid arthritis from 1987 and was treated with cyclophosphamide when she developed pulmonary symptoms in September 1997. On admission arthritis was subsided. Fine crackles on ausculation of lung, hypoxia, ground-glass appearance on chest X-ray were detected. The computed tomography of the chest disclosed diffuse interstitial shadow with patchy destruction of alveolar structures. Bronchoalveolar lavage demonstrated an increase in lymphocytes with predominance of suppressor-cytotoxic T cell subset (CD 8+). The histopathological examination of transbronchial lung biopsy showed interstitial inflammation with marked predominance of lymphocyte with intraalveolar exudate. Her condition got better and she discharged without definitive diagnosis and treatment for her respiratory symptoms. Eight hours after she went back home, she suddenly presented high fever and cough and gradually developed dyspnea. She was readmitted 5 days after the previous discharge. Although no specific precipitin antibody against various microorganisms was detected in her sera, the diagnosis of hypersensitivity pneumonitis was made. Thirty mg per day of prednisolone was resolved her symptoms promptly. There was no reported case with hypersensitivity pneumonitis and rheumatoid arthritis of other collagen diseases. The clinical course that arthritis and pulmonary symptoms appeared alternatively is of considerable interest to investigate for the pathogenesis of these two immune disorders.

Aged↗
PubMed1999

Vinexin forms a signaling complex with Sos and modulates epidermal growth factor-induced c-Jun N-terminal kinase/stress-activated protein kinase activities.

Vinexin, a novel protein that plays a key role in cell spreading and cytoskeletal organization, contains three SH3 domains and binds to vinculin through its first and second SH3 domains. We show here that the third SH3 domain binds to Sos, a guanine nucleotide exchange factor for Ras and Rac, both in vitro and in vivo. Point mutations in the third SH3 domain abolished the vinexin-Sos interaction. Stimulation of NIH/3T3 cells with serum, epidermal growth factor (EGF), or platelet-derived growth factor (PDGF) decreased the electrophoretic mobility of Sos and concomitantly inhibited formation of the vinexin-Sos complex. Phosphatase treatment of lysates restored the binding of Sos to vinexin, suggesting that signaling from serum, EGF, or PDGF regulates the vinexin-Sos complex through the Sos phosphorylation. To evaluate the function of vinexin downstream of growth factors, we examined the effects of wild-type and mutant vinexin expression on extracellular signal-regulated kinase (Erk) and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) activation in response to EGF. Exogenous expression of vinexin beta in NIH/3T3 cells enhanced JNK/SAPK activation but did not affect Erk activation. Moreover mutations in the third SH3 domain abolished EGF activation of JNK/SAPK in a dominant-negative fashion, whereas they slightly stimulated Erk. Together these results suggest that vinexin can selectively modulate EGF-induced signal transduction pathways leading to JNK/SAPK kinase activation.

3T3 Cells↗
PubMed1999

Human RNA helicase A is a lupus autoantigen that is cleaved during apoptosis.

Proteolytic cleavage by caspases is the central event in cells undergoing apoptosis. Cleaved proteins are often targeted by autoantibodies, suggesting that the cleavage of self Ags enhances immunogenicity and is prone to induce an autoimmune response. We found autoantibodies that immunoprecipitated a 140-kDa RNA-associated protein, provisionally designated Pa, in 11 of 350 patient sera that were positive for antinuclear Abs in an immunofluorescence test. The Pa protein gave rise to three fragments with m.w. ranging from 120-130 kDa during anti-Fas-activated apoptosis. Pure caspase-3 cleaved the Pa protein into a 130-kDa fragment corresponding to the largest of these three products. Peptide sequence analysis of a tryptic digest from immunoaffinity-purified Pa showed 100% identity to human RNA helicase A (RHA). The identity of Pa with RHA was further confirmed by immunoblotting with rabbit anti-RHA Ab using anti-Pa immunoprecipitates as substrates. All 10 anti-RHA-positive patients who were clinically analyzed were diagnosed as having systemic lupus erythematosus, and 7 of them had lupus nephritis. RHA is a multifunctional protein with roles in cellular RNA synthesis and processing. Inactivation of RHA by cleavage may be an important part of the process leading to programmed cell death. The cleaved RHA fragments that are produced during apoptosis may trigger an autoimmune response in systemic lupus erythematosus.

Amino Acid Sequence↗
PubMed1999

Anti-KS: identification of autoantibodies to asparaginyl-transfer RNA synthetase associated with interstitial lung disease.

Autoantibodies to five of the aminoacyl-transfer RNA (tRNA) synthetases have been described, and each is associated with a syndrome of inflammatory myopathy with interstitial lung disease (ILD) and arthritis. Serum KS, from a patient with ILD and inflammatory arthritis without evidence of myositis, immunoprecipitated a tRNA that was distinct from that precipitated by any described anti-synthetase or other reported tRNA-related Abs, along with a protein of 65 kDa. KS serum and IgG fraction each showed significant (88%) inhibition of asparaginyl-tRNA synthetase (AsnRS) activity, but not of any of the other 19 aminoacyl-tRNA synthetase activities. Among 884 patients with connective tissue diseases tested, only two other sera were found to immunoprecipitate tRNAs and proteins of identical gel mobility. These two and KS showed identical immunodiffusion lines using HeLa cell extract. The new sera significantly inhibited AsnRS without significant effects on other synthetases tested. Both patients had ILD but neither had evidence of myositis. These data strongly suggest that these three sera have autoantibodies to AsnRS, representing a sixth anti-synthetase. Anti-KS was more closely associated with ILD than with myositis. Further study of this Abs might prove useful in dissecting the stimuli responsible for the genesis of anti-synthetase autoantibodies.

Adult↗
PubMed1999

Heat sensitivity of double-stranded DNA-dependent protein kinase (DNA-PK) activity.

PURPOSE: The heat sensitivity of DNA-PK activity in hybrid cells and the possible restoration of this activity with extracts from scid cells (defective in DNA-PKcs), sxi-3 cells (defective in Ku80) and V794 (sxi-3 parental wild-type cells) was analysed. MATERIALS AND METHODS: Heat treatment of cells was performed in a water bath at 44 degrees C. The cell extract from scid cells or sxi-3 cells was added to heat-treated hybrid cell extracts, and the DNA-PK activity was assayed. RESULTS: When hybrid cells were heated at 44 degrees C for 15 min, DNA-PK activity was reduced to undetectable levels. The decreased DNA-PK activity could be restored in a concentration-dependent manner with the addition of scid cell extract. The sxi-3 cell extract could not restore heat-inactivated DNA-PK activity. CONCLUSIONS: DNA-PK was inactivated by heat treatment at 44 degrees C. Ku70/Ku80, but not Ku70 alone, could restore heat-inactivated DNA-PK.

Animals↗
PubMed1998

High mobility group proteins 1 and 2 can function as DNA-binding regulatory components for DNA-dependent protein kinase in vitro.

The DNA-dependent protein kinase (DNA-PK) holoenzyme consists of a 470-kDa catalytic subunit (DNA-PKcs), a DNA-binding regulatory component known as Ku protein, and double-stranded DNA (dsDNA) with ends. We previously reported that the activity of DNA-PK in vitro is stimulated by non-histone chromosomal high mobility group proteins (HMG) 1 and 2 comprising two similar repeats, termed domains A and B, and an acidic C-terminal. Here we demonstrate that in vitro HMG1 and 2 can completely replace Ku protein as the DNA-binding regulatory component of DNA-PK. DNA-PKcs and Ku protein were separately purified from Raji nuclear extracts, and reconstituted into the DNA-PK holoenzyme in the presence of dsDNA. DNA-PKcs alone catalyzed DNA-dependent phosphorylation at a very low but significant level, and HMG1 and 2 markedly stimulated the phosphorylation of alpha-casein and a specific peptide substrate in a DNA-dependent manner. The HMG2-domains (A+B) polypeptide devoid of the C-terminal acidic region was more effective for DNA-PKcs stimulation than the full-length HMG2, and HMG2-domain A and -domain B polypeptides. Anti(Ku protein) antibodies inhibited the DNA-dependent phosphorylation activity of the DNA-PKcs:Ku protein complex, but not that of DNA-PKcs alone or when it was complexed with HMG1 or 2. These results demonstrate that HMG1 and 2 can function as the DNA-binding regulatory component for DNA-PKcs in vitro, and imply that a conformational change of dsDNA, which is elicited by regulatory components, is important for the stimulation of DNA-PK activity of DNA-PKcs.

Amino Acid Sequence↗
PubMed1998

[A case of systemic sclerosis complicated with pneumoperitoneum and pneumatosis cystoides intestinalis].

Here we report a case of systemic sclerosis (SSc) complicated with pneumoperitoneum and pneumatosis cystoides intestinalis (PCI). A 58-year-old woman who had been treated with oxygen therapy for chronic respiratory failure caused by interstitial pneumonia was admitted to Tokyo Metropolitan Ohtsuka Hospital because of abdominal fullness. On admission, laboratory data showed accelerated erythrocyte sedimentation rate, mild anemia, hypoalbuminemia, and elevated level of lactose dehydrogenase (LDH). Anti-nuclear antibodies, anti-RNP antibodies, anti-Topoisomerase I antibodies, anti-Ku antibodies, and rheumatoid factor were positive. Chest and abdominal roentgenograms showed free air under the diaphragm, dilatation of small intestine and colon, and multiple intestinal cysts. The diagnosis of pneumoperitoneum and PCI was made with laboratory findings and radiographic findings. Her symptoms did not respond to medications altering colonic motility and oxygen therapy. Finally, abdominal symptoms and radiographic findings caused by pneumoperitoneum and PCI disappeared three weeks after treatment with 1,500 mg/day of kanamycin sulfate. PCI is rarely associated with SSc. Possible pathogenic relationship between these diseases was discussed.

Female↗
PubMed1998

[Pneumoperitoneum with systemic sclerosis].

We report a case of systemic sclerosis (SSc) complicated with benign pneumoperitoneum without apparent pneumatosis cystoides intestinalis (PCI). A 43-year-old woman was admitted to our hospital because of prominent abdominal distension in April 1997. Raynaud's phenomenon has been detected since 1991. She was suffering from recurrent diarrhea, constipation, and subileus. The diagnosis of SSc was made in 1996 based on the sclerosis in her face, forearms, and chest, and hypomotility of the esophagus. On admission, she presented no signs of peritoneal irritation. The laboratory data revealed that white blood cell count was 7,400/mm3 and C-reactive protein was 0.1 mg/dl. Chest and abdominal roentgenograms showed massive free air under the diaphragm, dilatation of small and large intestine, and air-fluid level. PCI was not apparent. Pneumoperitoneum was improved after four weeks with intravenous hyperalimentation. But she presented recurrent severe diarrhea and high fever whenever she tried to take food orally. Klebsiella pneumoniae was proved in her jejunal juice by bacteriologic examination. Intravenous prostaglandin F2 alpha and oral fosfomycin calcium intake made her condition better. Benign pneumoperitoneum without PCI is rarely reported in the patients with SSc. In her condition, weakness of intestinal wall, hypomotility of intestine, unusual bacterial overgrowth, and elevated intraluminal pressure made intraluminal gas go through the wall of the fragile intestine of SSc. As operation of intestine of SSc usually cause miserable outcome, pneumoperitoneum accompanied with SSc even if PCI is apparent or not must be treated with conventional manner while there is no signs of peritoneal irritation.

Adult↗
PubMed1998

[A case of primary Sjögren's syndrome accompanied by transverse myelitis].

Here we report a case of Sjögren's syndrome (SS) accompanied by transverse myelitis. A 46-year-old woman with 7-year history of primary SS was admitted to Tokyo Metropolitan Ohtsuka Hospital in September 1997 because of muscular weakness in lower extremities. She had had a low grade fever, numbness, and pain in bilateral lower extremities since July 1992. Neurological examination revealed transverse myelopathy at the level of Th 4, and peripheral neuropathy in lower extremities. Cerebrospinal fluid analysis showed slight elevation of protein and the cell count. A diagnosis of transverse myelitis and peripheral neuropathy presenting as neurologic manifestations of SS was made. Treatment was initiated with 30 mg of prednisolone, followed by improvement of fever and neurological findings. Although central nervous system complications of SS have been presented in Western countries, little information is available about Japanese patients. To our knowledge, this is the second case report which describes the occurrence of transverse myelitis in Japanese patients with SS.

Anti-Inflammatory Agents↗
PubMed1998

Chronic arthritis and carpo:metacarpal ratio in Japanese patients with adult Still's disease.

OBJECTIVE: To characterize Japanese patients having adult Still's disease (ASD) with chronic arthritis (> 6 months) and to examine the association of chronic arthritis with carpo:metacarpal ratio (CMC ratio), an index of radiographic progression in rheumatoid arthritis (RA). METHODS: Twenty-seven patients with ASD (16 women and 11 men, mean age at disease onset 27.7 years) were classified into 2 groups: patients with (chronic articular ASD, 16 patients, 59%) or without (systemic ASD, 11 patients, 41%) chronic arthritis. Clinical and laboratory findings were compared between both groups. CMC ratio was calculated on serial hand radiographs in patients with chronic articular ASD. RESULTS: In our series, serositis was rarely observed in chronic articular ASD. Peripheral arthritis (including transient arthritis), such as metacarpophalangeal, proximal interphalangeal, or ankle joint, was more frequently observed in chronic articular ASD than in systemic ASD (p < 0.05). Wrist arthritis was frequently observed also in systemic ASD; however, joint space narrowing of carpometacarpal or intercarpal joints was recognized only in chronic articular ASD (44%). CMC ratio at the last observation in 14 patients with chronic articular ASD was significantly decreased (0.526 +/- 0.039) compared to that at disease onset (0.553 +/- 0.034) (p < 0.05), while no decrease was observed in 4 with systemic ASD (0.565 +/- 0.062 at disease onset, 0.563 +/- 0.043 at the last observation). CONCLUSION: It is suggested that chronic articular ASD has certain characteristics. CMC ratio may be a quantitative index for assessment of radiographic changes of carpal joints, not only in RA but also in chronic articular ASD.

Arthritis↗
PubMed1997

Nuclear translocation of the catalytic component of DNA-dependent protein kinase upon growth stimulation in normal human T lymphocytes.

DNA-dependent protein kinase (DNA-PK), consisting of the 470-kDa catalytic component (DNA-PKcs) and the DNA-binding regulatory component Ku protein (p70/p80), catalyzes phosphorylation of a variety of DNA replication/transcription/repair factors in the presence of double-stranded DNA. In the resting states of human peripheral blood mononuclear cells, DNA-PK activity and the protein level of DNA-PKcs were very low in the nuclear extracts, but they were high in the whole cell extracts. Depending upon proliferation of the T lymphocytes, DNA-PK activity and the protein level of DNA-PKcs in the nuclear extracts greatly increased. Immunocytochemical analysis suggested translocation of DNA-PKcs from the cytoplasm to the nucleus upon growth stimulation in the T lymphocytes.

Amino Acid Sequence↗
PubMed1997

[An autopsy case of anti-neutrophil cytoplasmic antibodies associated vasculitis accompanied by autoimmune hepatitis and hepatocellular carcinoma].

Here we report an autopsy case with anti-neutrophil antibodies (ANCA) associated vasculitis accompanied by autoimmune hepatitis and hepatocellular carcinoma. A 69-year-old woman was admitted to Tokyo Metropolitan Ohtsuka Hospital in October 1995 because of leg edema. She had presented cough in 1990 and diagnosed as interstitial pneumonia, esophageal varices and liver chirosis. On admission, laboratory data showed mild anemia, hypoproteinemia, and marked gammagloblinemia. IgM-HA antibody, HBs antigen, HBs antibody, HCV antibody and HDV antibody were negative. Anti-nuclear antibody, anticentromere antibody, anti-neutrophil cytoplasmic antibody against myeloperoxidase and cathepsin G (MPO-ANCA and cathepsin G), rheumatoid factor and direct coombs test were positive. Serum level of AFP and CEA were elevated. Ultrasonography and computed tomography of abdomen scowed liver chirosis and tumor in left lobe of liver. The diagnosis of liver chirosis based on autoimmune hepatitis and Interstitial pneumonia was made with clinical course, laboratory findings and radiographic findings although liver biopsy was not performed. She complained of bloody stool due to ulcer of the large intestine, and died of liver failure which progressed rapidly. The autopsy findings detected that pulmonary fibrosis, liver fibrosis with multiple hepatocellular carcinoma, necrotizing crescentic glomerulonephritis, and vasculitis of small artery inn colon. This was the first report of MPO-ANCA associated vasuculitis complicated with autoimmune hepatitis and hepatocellular carcinoma. Clinical significance of ANCA and immunogenetic background of these diseases were discussed.

Aged↗
PubMed1997

[An adult case of dermatomyositis complicated with cecum perforation and panniculitis].

The case of dermatomyositis complicated with cecum perforation and panniculitis occurred in a 62-year-old woman was reported. She was admitted to Keio University Hospital with a history of proximal muscular weakness, and dysphagia. Physical examination showed erythema over the face and shoulder. Serum level of muscle enzymes was remarkably increased. The diagnosis of dermatomyositis was made based on proximal muscular weakness, elevated serum level of muscle enzymes and myogenic change of electromyocardiogram. The treatment with 60 mg/day of prednisolone was started, and was a good response. However, 7 months later the disease became active again when the amount of prednisolone was reduced to 13 mg/day. Subsequently she complained of abdominal pain on the right lower quadrant. The surgical findings included peritonitis due to the perforation of the cecum and multiple ulcers of the cecum. After operation, azathioprine was added. Four years and 9 months later, she noticed skin erythema with ulceration and subcutaneous nodule. Skin biopsy indicated the findings of the panniculitis with membrano-cystic lesion. It was thought that both cecum perforation and panniculitis were caused by angiopathy which was often seen in childhood dermatomyositis.

Cecal Diseases↗