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Biomedical subjects

A Suwa

Publications and source records attributed to A Suwa.

53 records · Page 3Linked to original sources
PubMed1994

Onset of polymyositis with autoantibodies to threonyl-tRNA synthetase during pregnancy.

A 24-year-old black woman developed polymyositis with autoantibodies to threonyl-tRNA synthetase in the 2nd trimester of her 3rd pregnancy. This was complicated by fetal loss and the development of severe relapsing myositis resistant to corticosteroid and azathioprine therapy. These features were also common in other cases in the literature. Antisynthetase antibodies had not been reported in myositis occurring during pregnancy and may be of interest regarding the pathogenesis of inflammatory myopathy complicating pregnancy.

Adult↗
PubMed1993

Identification of autoantibodies to RNA polymerase II. Occurrence in systemic sclerosis and association with autoantibodies to RNA polymerases I and III.

In this study, autoantibodies to RNA polymerase II from sera of patients with systemic sclerosis have been identified and characterized. These antibodies immunoprecipitated polypeptides of 220 kD (IIA) and 145 kD (IIC), the two largest subunits of RNA polymerase II, and bound both subunits in immunoblots. These polypeptides were immunoprecipitated by the anti-RNA polymerase II monoclonal antibody 8WG16, which recognizes the carboxyl-terminal domain of the 220-kD subunit, and their identity to the proteins bound by human sera was confirmed in immunodepletion studies. Sera with anti-RNA polymerase II antibodies also immunoprecipitated proteins that were consistent with components of RNA polymerases I and III. In vitro transcription experiments showed that the human antibodies were an effective inhibitor of RNA polymerase II activity. In indirect immunofluorescence studies, anti-RNA polymerase II autoantibodies stained the nucleoplasm, as expected from the known location of RNA polymerase II, and colocalized with the anti-RNA polymerase II monoclonal antibody. The human sera also stained the nucleolus, the location of RNA polymerase I. From a clinical perspective, these antibodies were found in 13 of 278 patients with systemic sclerosis, including 10 with diffuse and three with limited cutaneous disease, but were not detected in sera from patients with other connective tissue diseases and from normal controls. We conclude that anti-RNA polymerase II antibodies are specific to patients with systemic sclerosis, and that they are apparently associated with antibodies to RNA polymerases I and III. These autoantibodies may be useful diagnostically and as a probe for further studies of the biological function of RNA polymerases.

Adenoviridae↗
PubMed1992

Characterization of autoantibodies that recognize U4/U6 small ribonucleoprotein particles in serum from a patient with primary Sjögren's syndrome.

We identified autoantibodies that recognize the U4/U6 snRNPs in a serum from a 63-year-old Japanese patient (TT) with primary Sjögren's syndrome. This patient's serum immunoprecipitated U4 and U6 sn-RNAs exclusively from 32P-labeled HeLa cell extracts and a newly identified 120-kDa protein along with the Sm core proteins (B'/B, D, E, F, and G) from [35S] methionine-labeled HeLa cell extracts. Immunoblotting demonstrated that only the 120-kDa protein was recognized by this unique serum. In glycerol density gradient centrifugation, the 120-kDa protein reactive with TT serum cosedimented with U4 and U6 snRNAs, suggesting that the 120-kDa protein is a unique component of the U4/U6 snRNP particle. In the same study, the U4/U6 snRNP precipitated by TT serum sedimented only in the lower density, whereas anti-Sm antibodies precipitated U4/U6 snRNAs in a broad range of the gradient. This result suggests the presence of at least two molecular forms of the U4/U6 snRNP particles; larger particles, probably the U4/U5/U6 snRNP complex, and free particles. Thus, the U4/U6 snRNP recognized by TT serum includes the U4 and U6 snRNAs, with Sm core proteins, and the novel 120-kDa protein, and appears to be a free particle not associated with larger complexes.

Autoantibodies↗
PubMed1992

[Spontaneous remission of dermatomyositis which developed one month after normal delivery].

A case of dermatomyositis which developed one month after normal delivery and subsided spontaneously was reported. A 29-year-old woman gave birth to a healthy child. One month later, she noticed muscular pain and weakness of the upper extremities. On admission, there were diffuse edema of upper eyelids with heliotrope rash. The reddish skin rashes were observed on the extensor surfaces of the PIP and MP joints of fingers. Erythrocyte sedimentation rate was 29 mm/hr. The lactic dehydrogenase (LDH), SGOT, CK levels were 470 (normal 150 to 320 IU/l), 43 (normal 6 to 25 IU/l) and 317 (normal 21 to 110 IU/l) respectively. Autoantibodies to nuclear and cytoplasmic antigens were negative. Rheumatoid factor and anti-DNA antibody were negative. Thyroid function was normal. An electromyogram (EMG) demonstrated small amplitude short-duration polyphasic motor unit potentials. The muscle biopsy specimen from left upper arm showed degenerating muscle fibers and infiltration of inflammatory cells surrounding blood vessels. The skin biopsy revealed the presence of edema and perivascular infiltration of lymphocytes. Based on these clinical features and results of various diagnostic tests, a diagnosis of dermatomyositis was established. After the admission, muscle strength has improved dramatically and the CK returned to normal level without specific drug therapy. She has since been seen as an out patient, and complete remission lasted for two years up to date. Review of the literature disclosed that 13 cases of PM/DM which developed during pregnancy or postpartum have been reported including the present case. Detailed analysis showed that these patients were characterized by mild muscular diseases, rare occurrence of internal organ involvements and good response to steroid therapy. As our case, a spontaneous remission was also observed. Although the mechanism involved in occurrence of inflammatory myositis associated with pregnancy or delivery are not clarified, these patient indicated a presence of subset of PM/DM which do not require intensive drug therapy.

Adult↗
PubMed1990

Isolation and characterization of cDNA encoding the 80-kDa subunit protein of the human autoantigen Ku (p70/p80) recognized by autoantibodies from patients with scleroderma-polymyositis overlap syndrome.

Anti-Ku (p70/p80) autoantibodies in patients with scleroderma-polymyositis overlap syndrome recognize a 70-kDa/80-kDa protein heterodimer which binds to terminal regions of double-stranded DNA. In the present study, we isolated full-length cDNAs that encode the 80-kDa Ku subunit. Initial screening of a human spleen cDNA library with anti-Ku antibodies yielded a cDNA of 1.0 kilobase (kb) (termed K71) encoding a portion of the 80-kDa Ku polypeptide (identification based on immunological criteria). In RNA blots, this cDNA hybridized with two mRNAs of 3.4 and 2.6 kb. In rescreening of a cDNA library constructed from simian virus 40-transformed human fibroblast mRNA with the K71 cDNA as a hybridization probe, three positive clones were isolated, and that bearing the longest insert (termed Ku80-6) was selected for further characterization. In vitro transcription and translation experiments produced an immunoprecipitable polypeptide which comigrated with the 80-kDa Ku subunit. The Ku80-6 cDNA proved to be 3304 nucleotides in length, with an additional poly(A) tail, closely approximating the size of the larger mRNA. It contains a single long open reading frame encoding 732 amino acids (Mr = 82,713). The putative polypeptide has a high content of acidic amino acids and a region with periodic repeat of leucine in every seventh position which may form the "leucine zipper" structure. In genomic DNA blots, probes derived from the opposite ends of cDNA Ku80-6 hybridized with several nonoverlapping restriction fragments from human leukocyte DNA, indicating that the gene encoding the 80-kDa Ku polypeptide is divided into several exons by intervening sequences.

Amino Acid Sequence↗
PubMed1986

Synchrotron radiation at the Photon Factory for non-invasive coronary angiography: experimental studies.

Synchrotron radiation available at the Photon Factory, National Laboratory for High Energy Physics, provides a new X-ray source which is highly suitable for K-edge subtraction. This is due to its high intensity, its parallelism and its monochromaticity, available in a monochromator system. Experiments were performed using wiggler synchrotron radiation. Since the beam size is relatively-small for in-vivo imaging, a phantom coupled with a detector was moved horizontally using a scanning table. K-edge subtraction was successfully applied both to the coronary artery phantom filled with barium sulphate, and to rat angiography using iodine contrast material. The potential use and value of energy subtraction was successfully demonstrated.

Animals↗
PubMedDate not supplied

Rheumatoid arthritis associated with methotrexate-induced pneumonitis: improvement with i.v. cyclophosphamide therapy.

Pneumonitis is one of the most serious adverse effects associated with low-dose weekly methotrexate (MTX) therapy. Immediate cessation of MTX, and the introduction of oxygen therapy and glucocorticoids usually results in a dramatic improvement in the pulmonary toxicity. We report here a case of MTX-induced pneumonitis in a patient with rheumatoid arthritis (RA). Severe hypoxemia and interstitial infiltration in both lung fields did not respond to the withdrawal of MTX and the administration of oxygen and steroid pulse therapy. When intravenous cyclophosphamide (CYC) pulse therapy was initiated, however, rapid physiologic and radiographic improvement was seen. Our case suggests that CYC treatment may have a beneficial effect on MTX-induced pneumonitis that is resistant to steroid therapy.

Aged↗
PubMedDate not supplied

A case of polymyositis associated with hepatitis B infection.

This report describes the case of a 47-year old man who developed myositis in association with hepatitis B surface antigen-positive hepatitis. Interestingly, the myositis repeatedly worsened 2 months after the exacerbation of hepatitis in this case, suggesting a close association between hepatitis B infection and myositis. The dose of prednisolone was increased twice in order to treat the exacerbating myositis, resulting in improvement of the muscle symptoms, but the patient eventually died of liver failure. Only 5 other myositis patients with hepatitis B antigenemia have been reported in the literature. We review these cases of the association between hepatitis B infection and myositis.

Anti-Inflammatory Agents↗
PubMedDate not supplied

A case of systemic lupus erythematosus presenting with rectal ulcers as the initial clinical manifestation of disease.

Gastrointestinal involvement is often seen in patients with systemic lupus erythematosus (SLE). All parts of the gastrointestinal tract may be affected. However, rectal involvement at onset is rare. We describe here a case of SLE in which rectal ulcers due to vasculitis occurred as the initial manifestation of the disease without involvement of any other organ. The ulcers worsened, along with the appearance of lupus nephritis 5 years later When steroid therapy was initiated, there was rapid clinical and radiographic improvement. Our case suggests that rectal ulcer is a rare but important complication of SLE and can represent the initial and sole clinical manifestation of the disease.

Adult↗
PubMedDate not supplied

Clinical characteristics of Japanese patients with anti-PL-7 (anti-threonyl-tRNA synthetase) autoantibodies.

OBJECTIVE: The clinical and laboratory features of seven Japanese patients with anti-aminoacyl-tRNA synthetase (ARS) autoantibodies against PL-7 (anti-threonyl-tRNA synthetase) were analyzed and compared with previously published findings. METHODS: Serum samples from 1,135 Japanese patients with various autoimmune diseases were screened for anti-PL-7 antibodies using RNA and protein immunoprecipitation assays. The patients whose sera contained anti-PL-7 antibodies were assessed regarding clinical symptoms and clinical course. RESULTS: Sera from seven patients were found to have anti-PL-7 antibodies. These autoantibodies were associated with polymyositis/dermatomyositis (PM/DM) and/or interstitial lung disease (ILD). The clinical diagnoses of these seven patients were PM - systemic sclerosis (SSc) overlap (5 patients), DM (1 patient) and idiopathic pulmonary fibrosis (IPF) (1 patient). All patients had ILD with a chronic course and six also had arthritis (85%) and five sclerodactyly (71%). CONCLUSIONS: These results indicate that anti-PL-7 autoantibodies are closely associated with PM-SSc overlap as well as ILD, arthritis and sclerodactyly in our series of Japanese patients.

Adult↗
PubMedDate not supplied

Successful treatment of recurrent intracardiac thrombus in Behçet's disease with immunosuppressive therapy.

Behçet's disease (BD) is a chronic multisystem inflammatory disorder characterized by recurrent oral and genital ulcers, skin eruptions and uveitis. Neurological, gastrointestinal, and musculoskeletal systems are also involved. Although venous and arterial vasculitis occur in up to one-third of patients, intracardiac thrombus is a very rare complication. We herein report the case of a 46-year-old man with BD who presented with a large right atrial thrombus. Within a month after surgical removal, the thrombus recurred and was successfully treated with immunosuppressants that included prednisolone and cyclophosphamide.

Behcet Syndrome↗