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Biomedical subjects

T Tojo

Publications and source records attributed to T Tojo.

At least 19 recordsLinked to original sources

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

Specificity of antibodies to single-stranded (ss) DNA in SLE patients with anti-phospholipid syndrome.

Although the concept of anti-phospholipid syndrome has been proposed in patients with SLE and other rheumatic diseases, the immunological mechanism is still controversial. Recently, the crossreactivity between anti-cardiolipin antibody and anti-ssDNA antibodies has been discussed in relation to this syndrome. In the present study, the specificity such as the avidity and the crossreactivity of anti-ssDNA antibodies was examined to find a clue to clarify the question why all of anti-cardiolipin antibody positive patients do not have any specific clinical features, thrombosis and spontaneous abortion. The avidity of IgG anti-ssDNA antibodies was examined by salt elution studies in solid phase ELISA. The avidity of anti-ssDNA antibodies tended to be lower in 10 patients with specific features than in other 10 patients without those features. The crossreactivity of affinity purified IgG anti-ssDNA antibodies was investigated by competitive ELISA. Purified anti-ssDNA antibodies from 4 patients without specific features were slightly inhibited by negatively charged phospholipids, cardiolipin and phosphatidylserine, whereas purified anti-ssDNA antibodies from 2 patients with specific features, who were considered to have anti-phospholipid syndrome, were little inhibited by these phospholipids. The above results suggest that the specificity of anti-ssDNA antibodies appears, at least partly, in different manners whether specific features are present or absent in anti-cardiolipin antibody positive patients. Moreover, anti-ssDNA antibodies and anti-phospholipid antibodies may form separate groups of antibodies in patients with anti-phospholipid syndrome.

Antibody Specificity

Initial predictors of survival in patients with systemic sclerosis (scleroderma).

We conducted a retrospective study of 86 patients with systemic sclerosis (SSc) to clarify the initial predictors of survival at the first visit to the hospital. A life-table analysis of survival was performed concerning 137 items from their histories, physical examinations, and laboratory data. The observed cumulative survival rates were 78.0 percent at 5 years and 68.2 percent at 10 years. Ten items were found to be the initial predictors of survival in patients with SSc. Of these 10 items, 9 items showed significant differences within 5 years of the first visit to the hospital. Patients with resting electrocardiographic abnormalities, such as atrial or ventricular arrhythmias, or conduction disturbances, pulmonary fibrosis on the chest x-ray films, or decreased vital capacity had significantly lower survival rates. However, patients with anti-centromere antibody had a significantly better survival rate. In addition, males, aged patients over 65 years old, and patients with proteinuria, leucopenia, or hypergammaglobulinemia had significantly lower survival rates. Only patients with proximal scleroderma at the first visit to the hospital had a significantly lower survival rate after 8 years. These results are useful in predicting individual patients at risk of shortened survival and in managing these patients.

Adolescent

[Application of an expandable metallic Z-type stent for stenosis of the left main bronchus following tuberculosis--a case report].

A 32-year-old man had been suffering from dyspnea on exertion and stridor, which were due to stenosis of the left main bronchus as a complication of bronchial tuberculosis. A three-connection stent, 1.2 cm in diameter and 4.5 cm in length was placed at the site of the bronchial stenosis. Dyspnea disappeared 2 days after the procedure, and the pulmonary function 3 weeks later showed considerable improvements in %FVC, FEV1 and MMF.

Adult

[Clinical significance of anti-nucleolar antibodies detected by immunoprecipitation method in patients with systemic sclerosis].

We have characterized a clinical significance of anti-U3RNP, anti-7-2RNP, anti-RNA polymerase I and anti-PM-Scl antibody, autoantibodies to nucleolar proteins detected by immunoprecipitation method in patients with systemic sclerosis (SSc). In 248 patients with SSc, anti-U3RNP antibody was positive in 9 (3.6%), anti-7-2RNP antibody was positive in 7 (2.8%) and anti-RNA polymerase I antibody was positive in 3 (1.2%). But none of 248 patients was positive for anti-PM-Scl antibody. Anti-U3RNP antibody positive SSc patients showed significantly lower frequency of joint and lung involvements, compared with anti-U3RNP antibody negative SSc patients. Anti-7-2RNP antibody was found only in patients with limited scleroderma. The anti-7-2RNP antibody could be detected before appearance of skin thickening, so this indicate the usefulness of detecting anti-7-2RNP antibody in the early stage of SSc. Two of 3 anti-RNA polymerase I antibody positive patients were classified as diffuse scleroderma. All anti-RNA polymerase I antibody positive patients had high incidence of internal organ involvements including lung, heart and kidney, so two of these patients died of heart failure. These data showed the close clinical association of antigenic specificities of anti-nucleolar antibodies analysed by immunoprecipitation method, and indicated the usefulness of detecting these anti-nucleolar antibodies in subgrouping of patients with SSc.

Adult

Repeated intestinal ulcerations in a patient with systemic lupus erythematosus and high serum antiphospholipid antibody levels.

We report the case of a patient with SLE who had repeated ulceration of the small intestine requiring emergency surgery. Pathologic examination revealed microthrombosis and vasculitis at the site of the intestinal ulcers. High levels of antiphospholipid antibodies, thrombocytopenia, and prolonged prothrombin time coincided with the episodes of intestinal ulceration. Antiphospholipid antibodies may be involved in the development of thrombosis resulting in the repeated episodes of intestinal ulceration in this patient. This possibility should be considered in patients with SLE who have intestinal ulceration and appropriate antithrombotic medication should be administered.

Adult

[Studies on factors causing tooth resorption. 1. Role of prostaglandins as a chemical mediator on resorption of deciduous teeth in rabbits].

The aim of this study was to investigate the effects in the administration of indomethacin which is a specific inhibitor of prostaglandins (PGs) in order to understand the role of PGs in physiologic root resorption. For this study, 24 young rabbits aged 7 days which had been in utero for 31-32 days were used. The experimental group (N = 12) was injected with 5.0 mg/kg indomethacin every 12 h, and the control group (N = 12) was injected with normal saline solution every 12 h. 4 animals of each group were sacrificed at the 9th, 11th and 13th day, respectively. Their maxillary deciduous incisors embedded in paraffin were sectioned serially 7 mus in thickness. From each sample was counted the number of odontoclasts appearing on the root surface and measured the volume of the root in the maxillary deciduous incisor. The results were as follows: 1. The appearance of odontoclasts increased in a day-related manner from 9 days to 13 days on the resorption of maxillary deciduous teeth in the control and experimental rabbits. 2. The number of odontoclasts was significantly decreased by the administration of indomethacin (9 days P less than 0.05, 11 and 13 days P less than 0.01). 3. The amount of the root resorption was significantly inhibited by the administration of indomethacin at 9 days which was the initial stage of root resorption in the maxillary deciduous incisors, and then the effect of inhibition rapidly disappeared. These results strongly suggest that PGs can possibly act as a chemical mediator of odontoclastic root resorption occurred during tooth exchange.

Animals