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Biomedical subjects

T Sumida

Publications and source records attributed to T Sumida.

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

Aortic valve replacement in a patient with idiopathic thrombocytopenic purpura.

A patient with aortic regurgitation and idiopathic thrombocytopenic purpura underwent a successful valve replacement. Cardiac surgery requiring a cardiopulmonary bypass in idiopathic thrombocytopenic purpura can be safely carried out with the preoperative intravenous administration of high-dose gammaglobulin, which may thereby reduce the need for either perioperative transfusion or prophylactic splenectomy.

Aortic Valve↗
PubMed1999

Genetic diagnosis of micrometastasis based on SCC antigen mRNA in cervical lymph nodes of head and neck cancer.

This study is designed to assess gene expression of squamous cell carcinoma antigen (SCCA) mRNA to detect micrometastases in cervical lymph nodes (LNs) of head and neck cancer. We examined the expression of SCCA mRNA in 12 primary tumors and 212 cervical LNs (101 LNs taken from 8 patients with tongue cancer, 71 from 7 patients with gingival cancer, 19 from 2 patients with laryngeal cancer, 9 from 2 patients with pharyngeal cancer, 7 from 1 patient with cancer of the buccal mucosa, and 5 from 1 patient with cancer of floor of the mouth). Detectability of metastatic LNs by nested and single reverse transcriptase-polymerase chain reaction (RT-PCR) was compared with semiserial sections (hematoxylin-eosin staining and keratin immunostaining). All primary tumors expressed SCCA mRNA. Of 198 histologically metastasis-negative nodes, SCCA mRNA was detected in 37 (18.7%) by nested PCR. Eleven micrometastatic foci in 9 LNs (4.6%) were discovered by semiserial sectioning. This suggests that SCCA mRNA is a promising tumor marker for detecting the micrometastases in cervical LNs of head and neck cancer.

Antigens, Neoplasm↗
PubMed1999

Differential properties of the optical-isomers of pranidipine, a 1,4-dihydropyridine calcium channel modulator.

Pranidipine is an optically-active 1,4-dihydropyridine (DHP) voltage-dependent L-type calcium channel inhibitor. Certain enantiomeric pairs display opposite effects, i.e., inhibition and activation of the calcium channel while others exhibit the same qualitative actions. We investigated pranidipine, a new DHP, using a paradigm of vascular smooth muscle reactivity. In isolated rat aorta, depolarized with 80 mM KCl, both isomers of pranidipine caused a right-ward shift of the concentration-contraction curves for extracellular Ca2+. The apparent pA2, values of the S-isomer and R-isomer were 10.03 and 8.36, respectively, providing evidence that the calcium channel blocking action of the S-isomer was 50 times more potent than that of the R-isomer. Antihypertensive actions of these two isomers studied in pentobarbital-anaesthetized spontaneously hypertensive rats, revealed that the S-isomer, at doses of 3-30 microg/kg i.v. decreased blood pressure in a dose-dependent manner, while the R-isomer had no effect on blood pressure at those doses. We conclude that the pair of enantiomers of pranidipine qualitatively display the same Ca2+ channel blocking action and that neither isomer exhibits Bay K 8644-like activation. Pranidipine may be useful in studies on the architecture of the DHP receptor 'pocket'.

Analysis of Variance↗
PubMed1999

Intraosseous epithelioid hemangioendothelioma of the mandible: a case report with an immunohistochemical study.

Epithelioid hemangioma is the prototype of a group of vascular tumors characterized by epithelioid endothelial cells. Hemangioendothelioma of bone is a rare lesion that constitutes less than 0.5% of primary malignant skeletal tumors. We report and discuss a case of epithelioid hemangioendothelioma arising intraosseously in the anterior portion of the mandible in a 76-year-old woman. The case was treated successfully by wide resection. Radiographically, the tumor mass showed osteolysis and expansion. Histologically, the tumor showed invasive and destructive growth, although it lacked frequent mitotic figures and severe atypia. On immunohistochemical study, tumor cells exhibited characteristics of mesenchymal and endothelial origin, i.e., strong to moderate immune reactivity against vimentin, factor VIII-related antigen (F8RA), Ulex europaeus agglutinin type 1 lectin (UEA-1), and CD 34, but not against keratin, epithelial membrane antigen (EMA) or S-100 protein (S100). The proliferating cell nuclear antigen (PCNA)-positive cell index was 27.5%. These pathological findings suggested a borderline malignant potential for this tumor. Thus, clinically, wide resection with or without dissection of regional lymph nodes is recommended.

Aged↗
PubMed1999

Conserved T cell receptor complementarity-determining region 3 of ocular T cells in mice with experimental autoimmune uveoretinitis.

PURPOSE: To characterize T cells infiltrating into the ocular tissues of mice with experimental autoimmune uveoretinitis (EAU) immunized with interphotoreceptor retinoid-binding protein (IRBP). METHODS: The T cell receptor (TCR) repertoire on T cells obtained from ocular lesions of EAU mice was analyzed by reverse transcriptase-polymerase chain reaction. The clonotype of the T cells was examined by the single-strand conformation polymorphism (SSCP) method, followed by sequence analysis of the TCR beta-chain complementarity-determining region 3 (CDR3). RESULTS: The repertoire of the TCR BV gene in T cells from inflamed lesions was heterogeneous. SSCP analysis showed accumulation of multiple T cells specifically in ocular tissues of EAU mice, suggesting that these cells were expanded by an antigen-driven stimulation. Junctional sequence analysis demonstrated the presence of highly conserved amino acid sequence motifs (AGTGG, AGD) in CDR3 of BV2-positive T cells. CONCLUSIONS: Our findings suggest that T cells infiltrating into ocular lesions of EAU mice recognize restricted T cell epitopes of IRBP, resulting in autoimmune uveoretinitis.

Amino Acid Sequence↗
PubMed1999

Relationship between clinical features and binding domains of anti-prothrombin autoantibodies in patients with systemic lupus erythematosus and antiphospholipid syndrome.

Autoantibodies against prothrombin, including lupus anticoagulant antibodies (LAC), have been identified in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). To identify the epitopes of LAC in patients with SLE and APS, we analyzed B cell epitopes of anti-prothrombin Abs. Prothrombin was purified from fresh plasma samples from healthy subjects, and fragmented by thrombin. Two fragments (prethrombin-1, 50 kDa, and fragment-1, 22 kDa) were separated and used for further experiments. The two fragments were coated on irradiated plate and the binding activities of sera from 13 patients with anti-prothrombin Abs (SLE, 7; APS, 4; SLE+APS, 2) were determined by using ELISA. The assay was conducted under the following conditions: use of irradiated plates, and TBS containing Tween-20. We detected two types of anti-prothrombin Abs. The first was anti-prethrombin-1 (n=5) while the other was Ab against fragment-1 (n=8). There were no patients with Abs that showed binding activities to both fragments. A higher proportion of patients with thrombosis were positive for anti-prethrombin-1 Abs (80%) than for anti-fragment-1 Abs (25%). Two patients with anti-prethrombin-1 Ab were positive for LAC and negative for anti-cardiolipin-beta2 glycoprotein I antibody (aCL-beta2GPI). Our results strongly support the notion that both prethrombin-1 and fragment-1 on prothrombin molecule are B cell epitopes.

Antibody Specificity↗
PubMed1999

Cloning and functional analysis of anti-double strand DNA IgG autoantibodies using the phage-display method.

To examine the relationship between pathophysiological effects and molecular features of anti-double-stranded (ds)DNA autoantibodies (Abs), we isolated anti-dsDNA Ab fragments by using the phage-display method. Fd ç and light-chain DNA were PCR amplified from peripheral blood lymphocytes of a patient with systemic lupus erythematosus (SLE), complicated with lupus nephritis. They were then inserted into a phagemid vector, pComb3-H. We generated eight Fab fragments that specifically bound to solid-phase DNA. The Fab clones stained positively using Crithidia luciliae, indicating that they were anti-dsDNA antibodies. Nucleotide sequences of VH of Fab clones were very similar and appeared to be derived from VH26 germline gene. Differences in the activities of anti-dsDNA Ab of the Fab clones may be ascribed to the diversity of VL. Fab fragments with anti-dsDNA Ab activities exhibited a positive charge on isoelectric focusing, consistent with pathogenic features. Our results indicate that anti-dsDNA Ab Fab fragments obtained by the phage-display method in the present study may possess molecular and functional characteristics of pathogenic anti-dsDNA autoAbs in SLE.

Amino Acid Sequence↗
PubMed1999

Alpha-amylase functions as a salivary gland-specific self T cell epitope in patients with Sjögren's syndrome.

Analyses of T cell receptors (TCR) on T cells infiltrating labial salivary glands of patients with Sjögren's syndrome (SS) indicate that the cells expand by antigen stimulation in context of major histocompatibility complex (MHC). To elucidate the autoantigens recognized by T cells infiltrating in labial salivary glands from patients with SS, proteins derived from human salivary gland cDNA libraries were screened by West-Western method using TCR-CDR3 probe, which is antigen recognition region of TCR on T cells. 13 cDNA clones were detected as proteins binding to TCR-CDR3 region. One was a human alpha-amylase salivary precursor (AA54-407), suggesting that alpha-amylase might be a salivary gland-specific autoantigen. To examine whether alpha-amylase acts as an antigen in labial salivary glands, PBL from 11 patients with SS were incubated with 9 different synthetic amino acids of alpha-amylase or salivary alpha-amylase. SSCP analysis on TCR clearly showed that alpha-amylase reactive T cells were observed in labial salivary glands from 3 of 11 patients with SS (27%). These findings support the possibility that alpha-amylase functions as a salivary gland-specific T cell epitope and induces autoimmunity in SS.

Amino Acid Sequence↗
PubMed1999

Single cell analysis of T cells infiltrating labial salivary glands from patients with Sjögren's syndrome.

Sjögren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration into the lacrimal and salivary glands leading to symptomatic dry eyes and mouth. To analyze the function of T cells infiltrating the labial salivary glands, we analyzed T cell receptor (TCR) beta and alpha chains, the expression of various cytokine mRNAs, and apoptosis associated genes in predominant TCR BV2+ T cells in the labial salivary glands of patients with SS at the single cell level. TCR BV2+ T cells in the labial salivary glands were sorted as single cells by flow-cytometry, and then examined by a single cell polymerase chain reaction (PCR). We isolated 18 TCR BV2+ T cell clones from three patients with SS. In six clones, there were highly conserved amino acid motifs (RDxG, GNT, QGxxQETQ) in the CDR3 region of the TCR beta chain. Three of the six clones showed conserved amino acids (EDxTG, or ExxTG) in the CDR3 region of the TCR alpha chain, suggesting restricted T cell epitopes. All TCR BV2+ clones expressed IL-2 mRNA, and six clones were able to produce IL-4, indicating that the cells were Th0 type T cells. All TCR BV2+ clones in the labial salivary glands were CD4+ T cells, and ten clones overexpressed Fas antigen at the mRNA level. In contrast, only one clone expressed Fas-ligand (Fas-L) mRNA, and neither perforin nor granzyme A/B was expressed. In conclusion, these findings support the notion that TCR BV2+ T cells that infiltrate labial salivary glands recognize restricted epitopes and function as CD4+ Th0 type T cells in the induction phase of autoimmunity.

Amino Acid Sequence↗
PubMed1999

Detergent and antigen fragility affect the ELISA for measurement of anti-prothrombin autoantibodies.

OBJECTIVE: Some investigators have reported that anti-prothrombin autoantibodies (aPT) in lupus anticoagulant positive sera were detectable by ELISA. Discrepancies in aPT ELISA were observed by some investigators. To clarify this situation, we tested the binding of aPT positive sera to purified prothrombin under various conditions. METHODS: We performed aPT ELISA under different conditions. The variables we tested were: ELISA plate (untreated or gamma irradiated polystyrene plates), buffer (phosphate buffered saline or Tris buffered saline), detergent (presence or absence of Tween-20), and antigen condition (intact or fragmented prothrombin). RESULTS: Anti-PT from patients with lupus or antiphospholipid syndrome were similarly bound to prothrombin with both buffers. Addition of Tween-20 to the buffer increased reactivity in the irradiated plate assay, but decreased reactivity in the untreated plate assay. Reactivities in 90% of lupus sera were decreased by the use of fragmented prothrombin. In contrast, the reactivity of serum from a healthy subject was remarkably increased by antigen fragmentation. CONCLUSION: The discrepant ELISA results in measurement of aPT in the various reports may have been due to the use of detergent in the buffer and condition of the prothrombin used as antigen. In our experiments the best ELISA condition for measurement of aPT was achieved using buffer with Tween-20 detergent, with prothrombin directly coated onto irradiated polystyrene plates.

Antiphospholipid Syndrome↗
PubMed1999

Species specificity of cytokeratin polypeptide expression in the submandibular gland.

Using nine monospecific and seven polyspecific monoclonal antibodies (MoAbs) against cytokeratin (CK), we immunohistochemically studied the species specificity of CK localization in human, rat, mouse, hamster and guinea pig submandibular glands (SMGs). All species showed different staining patterns with various degrees of intensity. The pattern of immunostaining was broadly classified into three groups. Group I showed positive reactivity to the rodent salivary gland, but not to human SMGs (6B10 and 34betaE12). Group 2 showed the reverse staining pattern (M20, A53-B/A2 and Ks19.1). Group 3, for which almost all species were positive, showed interspecific diversity in the staining pattern (CY-90, K8.12, K8.13, C-11 and KH-1). Species specificity of CK should always be taken into consideration when immunohistochemically examining CK expression during development or during carcinogenesis in rodents.

Animals↗
PubMed1999

A single cell analysis of TCR AV24AJ18+ DN T cells.

The T-cell receptor (TCR) BV gene of human TCR AV24+ double-negative (DN) T cells, a novel subset of natural killer (NK) T cells, was investigated by single-cell sorting and single-cell polymerase chain reaction (PCR) methods. Seven of eleven TCR AV24+ DN T-cell clones utilized TCR BV8, three BV9, and one BV6. Six of seven TCR AV24/BV8+ DN T-cell clones had identical TCR beta and alpha chains, indicating that they were the same clone. All three TCR AV24/BV9+ DN T-cell clones also demonstrated the same amino acids in the CDR3 region. These findings strongly suggest that the usage of TCR beta and alpha chains on TCR AV24+ DN T cells is extremely restricted, supporting the notion that these cells recognize highly limited T-cell epitopes on antigens. All TCR AV24+ clones expressed the NKR-P1A mRNA, and so were true NK T cells. IL-2 and IL-4 mRNAs were detected in all clones, suggesting that the majority of these cells were Th0-type T cells. Six clones overexpressed Fas-ligand (Fas-L) mRNA and Fas antigen was detected on all clones at the mRNA level. In conclusion, TCR AV24+ DN T cells might recognize restricted T-cell epitopes on antigens and function as Th0-type T cells, inducer cells to Th1- or Th2-type T cells (regulatory T cells), and as Fas-L-positive cytolytic T cells.

Amino Acid Sequence↗
PubMed1999

Right ventricular infarction complicating coronary artery bypass grafting.

Intraoperative right ventricular infarction immediately after coronary artery bypass grafting is a rare and potentially serious complication. We report a case in which an additional coronary artery bypass graft to a right ventricular branch with 99% stenosis brought about recovery from profound acute right ventricular failure. This case shows that complete revascularization to all graftable vessels, including even the right ventricular branch, is mandatory for successful coronary artery bypass grafting.

Angina Pectoris↗
PubMed1999

Dieulafoy's lesion of the esophagus as a probable complication of Takayasu's arteritis.

Dieulafoy's lesion is an abnormal submucosal artery in the gastrointestinal tract characterized by massive gastrointestinal bleeding. We describe a patient who developed Dieulafoy's lesion of the esophagus in the course of isolated pulmonary Takayasu's arteritis. Angiographic findings indicated a relationship between pulmonary arterial involvement of Takayasu's disease and Dieulafoy's lesion of the esophagus. This observation represents the first report of the association between Takayasu's arteritis and Dieulafoy's lesion of the esophagus.

Adult↗