Biomedical subjects

Hiroshi Hashimoto

Publications and source records attributed to Hiroshi Hashimoto.

At least 73 records · Page 4Linked to original sources

PubMed2004

Glyceraldehyde 3-phosphate dehydrogenase is a novel autoantigen leading autoimmune responses to proliferating cell nuclear antigen multiprotein complexes in lupus patients.

Using 2-dimensional electrophoresis and ion-pair chromatography, we have identified elements of proliferating cell nuclear antigen (PCNA) multiprotein complexes that are reactive to antibodies in sera from patients with systemic lupus erythematosus. Among the various elements of the complexes, a 37 kDa protein (PI 8.5) that specifically reacted with SLE sera, but not with sera from patients with other connective tissue diseases, was identified as glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Immunoblot analysis showed that SLE sera reactive with the 37 kDa protein specifically reacted with GAPDH, as did anti-GAPDH mAbs. The purified autoantibodies to GAPDH from lupus serum showed both nuclear speckled and cytoplasmic staining patterns in immunofluorescence on Hep-2 cells. In addition, enzyme-linked immunosorbent assay (ELISA) revealed the presence of anti-GAPDH autoantibodies in 47% of lupus patients. Longitudinal analysis of the reactivity of lupus sera to PCNA complexes showed the autoimmune response to spread from GAPDH to other elements of PCNA complexes, and the presence of anti-GAPDH antibodies was significantly correlated with increased levels of serum PCNA. Taken together, these findings suggest that GAPDH interacting with PCNA in association with its cellular function is a novel autoantigen recognized by lupus sera, and that GAPDH thus plays an important role in the induction of autoimmune responses against the PCNA complex.

Animals↗

PubMed2004

Congenital (infantile) pseudarthrosis of the fibula associated with osteofibrous dysplasia.

We describe a recently noted association of congenital (infantile) pseudarthrosis of the lower leg with osteofibrous dysplasia. The patient was a 2-year-old boy who presented with a deformed left ankle joint and three cutaneous cafe-au-lait spots. Radiography demonstrated pseudarthrosis of the left distal fibula and a round lucent lesion adjacent to the proximal part of the pseudarthrosis. Histologically, the surgically removed fibula with pseudarthrosis showed a fibromatosis-like fibrovascular proliferation and nonspecific reparative changes. The focal lucent area demonstrated a fibro-osseous lesion, which was histologically identical to osteofibrous dysplasia. This case provides further evidence that osteofibrous dysplasia may be associated with congenital (infantile) pseudarthrosis of the lower leg.

Child, Preschool↗

PubMed2004

Coexpression of NOR1 and SIX3 proteins in extraskeletal myxoid chondrosarcomas without detectable NR4A3 fusion genes.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare mesenchymal tumor cytogenetically characterized by reciprocal translocations, such as t(9;22)(q22;q12) and t(9;17)(q22;q11), which result in EWSR1/NR4A3 and TAF15/NR4A3 fusion genes (alias EWS/NOR1, TAF2N/NOR1), respectively. NOR1 is an orphan nuclear receptor and acts as a transcription factor that can bind to its putative coactivator, SIX3. Although the NOR1 fusion protein has been implicated in oncogenesis of EMC, a small fraction of EMC lacks detectable rearrangements of the NR4A3 gene or 9q22. We report a case of EMC with no detectable NR4A3 gene alterations, as assessed with various molecular techniques including reverse transcription-polymerase chain reaction (RT-PCR), Southern blotting, interphase fluorescence in situ hybridization, and PCR single-strand conformation polymorphism-but with coexpression of native NOR1 and SIX3. In our survey of another 18 EMCs, we identified one more case expressing both NOR1 and SIX3 but lacking NR4A3 fusion. Fourteen tumors with detectable NR4A3 fusion genes (EWSR1-NR4A3; TAF15-NR4A3) expressed neither native NOR1 nor SIX3. SIX3 expression is normally confined specifically to the developing eye and fetal forebrain, although the expression of NR4A3 is largely ubiquitous. Our data suggest that aberrant coexpression of NOR1 and SIX3 is a potential alternative mechanism underlying the development of EMC.

Aged↗

PubMed2004

Structural basis for Ca(2+)-induced activation of human PAD4.

Peptidylarginine deiminase 4 (PAD4) is a Ca(2+)-dependent enzyme that catalyzes the conversion of protein arginine residues to citrulline. Its gene is a susceptibility locus for rheumatoid arthritis. Here we present the crystal structure of Ca(2+)-free wild-type PAD4, which shows that the polypeptide chain adopts an elongated fold in which the N-terminal domain forms two immunoglobulin-like subdomains, and the C-terminal domain forms an alpha/beta propeller structure. Five Ca(2+)-binding sites, none of which adopt an EF-hand motif, were identified in the structure of a Ca(2+)-bound inactive mutant with and without bound substrate. These structural data indicate that Ca(2+) binding induces conformational changes that generate the active site cleft. Our findings identify a novel mechanism for enzyme activation by Ca(2+) ions, and are important for understanding the mechanism of protein citrullination and for developing PAD-inhibiting drugs for the treatment of rheumatoid arthritis.

Amino Acid Motifs↗

PubMed2004

Crystallization and preliminary X-ray crystallographic analyses of EcoO109I and its complex with DNA.

EcoO109I is a type II restriction endonuclease that recognizes seven base pairs of the degenerate and discontinuous sequence RGGNCCY. The enzyme and its complex with DNA were successfully crystallized by the hanging-drop vapour-diffusion method using polyethylene glycols as precipitants. The crystal of EcoO109I belongs to space group I4, with unit-cell parameters a = b = 175.5, c = 44.6 angstoms, and that of the DNA complex belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 49.1, b = 71.8, c = 203.2 angstroms. Full sets of X-ray diffraction data from the enzyme and its complex with DNA were collected to 2.4 and 1.9 angstroms resolution, respectively.

Catalysis↗

PubMed2004

Suppression of collagen-induced arthritis by natural killer T cell activation with OCH, a sphingosine-truncated analog of alpha-galactosylceramide.

OBJECTIVE: OCH, a synthetic analog of alpha-galactosylceramide with a truncated sphingosine chain, stimulates natural killer T (NKT) cells to produce predominantly Th2 cytokines. Thus, OCH may be a potential agent for the treatment of Th1-mediated autoimmune diseases. This study was designed to evaluate the protective effects of OCH on collagen-induced arthritis (CIA) in mice. METHODS: Mice were immunized with type II collagen (CII) and injected intraperitoneally twice per week with OCH, before or after the onset of CIA. They were monitored to assess the effect of OCH treatment on the severity of disease. Anti-CII antibodies and cytokine production were measured by enzyme-linked immunosorbent assay. Expression of cytokine genes was determined by quantitative reverse transcriptase-polymerase chain reaction. RESULTS: OCH inhibited CIA in wild-type C57BL/6 (B6) mice but not in NKT-deficient mice. OCH suppressed CIA in SJL mice, which are prone to autoimmune diseases and have a deficiency in the number and function of NKT cells which is similar to that in patients with autoimmune diseases, even after disease has already developed. Disease protection conferred by OCH correlated with its ability to selectively induce Th2 cytokine production mediated by NKT cells and to promote collagen-specific Th2 responses. Neutralization of interleukin-4 (IL-4) or IL-10 with monoclonal antibodies abolished disease protection by OCH, indicating a critical role for these cytokines. CONCLUSION: Taken together, our findings suggest that OCH holds possibilities as a therapeutic agent for autoimmune diseases such as rheumatoid arthritis.

Animals↗

PubMed2004

TFG is a novel fusion partner of NOR1 in extraskeletal myxoid chondrosarcoma.

Extraskeletal myxoid chondrosarcoma (EMC) is characterized by recurrent chromosomal translocations resulting in fusions of the nuclear receptor gene NOR1 (also known as CHN or TEC) to various N-terminal partners, including EWS and TAF2N (or RBP56). Significant structural homology of EWS or TAF2N to TLS (or FUS) prompted us to investigate a potential novel gene fusion of NOR1 to TLS in EMCs without detectable known NOR1 fusions. In one of the EMCs examined, our reverse-transcription polymerase chain reaction using NOR1 and TLS primers unexpectedly amplified a cDNA sequence derived not from a TLS/NOR1 fusion but from a TFG/NOR1 fusion, a hitherto undescribed fusion type in EMC, probably a result of incidental misannealing by the TLS primer, which has a sequence partially identical to TFG. Encoding a protein with a putative coiled-coil structure, TFG previously was identified by a homology search in the Expressed Sequence Tag Database as having an SPYGQ-rich region similar to the N-terminal parts of EWS and TLS. TFG/NOR1 fusion appears to play an oncogenic role equivalent to those of other NOR1 fusions in EMC.

Amino Acid Sequence↗

PubMed2004

Anticyclic citrullinated peptide antibodies in patients with mixed connective tissue disease.

The clinical significance of anticyclic citrullinated peptide (CCP) antibodies in patients with mixed connective tissue disease (MCTD) was assessed. Altogether, 86 sera from MCTD patients, 96 from rheumatoid arthritis (RA) patients, 42 from systemic lupus erythematosus (SLE) patients, 23 from systemic sclerosis (SSc) patients, 21 from polymyositis/dermatomyositis (PM/DM) patients, and 17 from those with Sjögren's syndrome (SjS) were tested for anti-CCP antibodies using an enzyme-lined immunosorbent assay. Among the 96 RA patients, anti-CCP antibodies were detected in 85%, with the frequency being significantly higher than in MCTD, SLE, SSc, PM/DM, and SjS patients (9%, 14%, 13%, 14%, and 18%, respectively; P < 0.001). Among eight MCTD patients who fulfilled the diagnostic criteria for RA, only 50% had anti-CCP antibodies, and the prevalence was significantly lower than for all RA patients (p < 0.01). All eight patients who fulfilled the criteria for RA had overlap of SLE and SSc, except one patient, whereas the four anti-CCP-positive patients who did not fulfill the criteria for RA had SjS without overlapping features of SLE and SSc; moreover, most of their antibody titers were low. These results suggested that anti-CCP antibodies are associated with RA in MCTD patients, but careful diagnosis of RA is required if patients with low titers of anti-CCP antibodies lack overlapping SLE and SSc.

Journal Article↗

PubMed2004

Expression of anaplastic lymphoma kinase in soft tissue tumors: an immunohistochemical and molecular study of 249 cases.

Although anaplastic lymphoma kinase (ALK) has been considered a diagnostic marker specifying a subset of anaplastic large cell lymphomas and inflammatory myofibroblastic tumors (IMTs), the existence of this receptor in some other mesenchymal malignancies has been recently reported. We examined a wider variety of soft tissue tumors to further advance the survey of ALK status in mesenchymal lesions. ALK protein expression was evaluated immunohistochemically with 2 specific antibodies (ALK1 and 5A4) in 249 benign and malignant soft tissue tumors, and the expression of ALK transcripts and 8 types of ALK fusion transcripts was assessed using reverse transcription-polymerase chain reaction (RT-PCR) in 165 and 100 tumors, respectively. Moreover, ALK gene status was analyzed by interphase fluorescence in situ hybridization (FISH) in 17 tumors with ALK expression. Immunohistochemically, ALK protein was detected in 69 cases (28%), including IMTs (4 of 4), rhabdomyosarcomas (4 of 7), various lipogenic tumors (35 of 65), Ewing's sarcoma/peripheral primitive neuroectodermal tumors (6 of 10), malignant fibrous histiocytomas (8 of 37), leiomyosarcomas (3 of 18), and other non-IMT tumors (9 of 108); however, most of these, except the IMTs, displayed merely low-level expression. Although ALK transcripts were identified in 85 (52%) of the 165 cases examined by RT-PCR, the full-length (wild-type) ALK, rather than the truncated or chimeric forms detected in IMTs, predominated in most non-IMT tumors. Except for 2 IMTs, all cases with the expression of ALK messages displayed no detectable ALK fusion transcripts. More than 67% of the cases analyzed by both RT-PCR and immunohistochemical assays demonstrated concordant results. ALK gene amplification was found in 4 non-IMT tumors (2 leiomyosarcomas and 1 case each of rhadomyosarcoma and malignant fibrous histiocytoma) analyzed by FISH, and the rearrangement of this gene was identified in 2 IMTs. The current data expands the variety of non-IMT soft tissue tumors with ALK expression, and warrants further investigation of its underlying molecular mechanisms.

Anaplastic Lymphoma Kinase↗

PubMed2004

Primary pulmonary synovial sarcoma: a clinicopathologic, immunohistochemical, and molecular study of 11 cases.

Primary synovial sarcoma (SS) of the lung is rare and may create diagnostic challenges. We reviewed 11 cases of pulmonary SS (PSS) confirmed by the presence of a tumor-specific SYT-SSX fusion gene to verify their clinicopathologic features including immunohistochemical and genetical profiles. The tumors occurred in 4 men and 7 women (age 29 to 81 years; mean age, 58; median age, 50), and ranged in size from 2 to 15.5 cm (mean, 9 cm). Of the 11 tumors, 10 were a monophasic fibrous type and 1 was a poorly differentiated type. Mitotic rate ranged from 8 to 43 per 10 high-power fields. All cases showed at least focal immunohistochemical positivity for AE1/AE3, CAM5.2 and/or epithelial membrane antigen. High proliferating cell nuclear antigen labeling index (>20%) was found in 8 of 10 cases (80%). Eight (90%) of 9 cases were negative for E-cadherin, and 1 case (10%) exhibited reduced expression of the molecule. The aberrant expression of beta-catenin within cytoplasm and/or nuclei was observed in 6 of 9 (67%) cases. SYT-SSX1 and SYT-SSX2 fusion gene transcripts were detected in 9 and 2 cases, respectively. In 10 patients with follow-up, 3 (30%) had local recurrences, and 4 (40%) developed distant metastases. Five (50%) patients died of the tumor 1 to 9 years after surgery, and 5 (50%) were alive and disease-free in the period ranging from 3 months to 5.5 years. In conclusion, PSS tends to occur in older patients and shows an aggressive behavior probably due to its anatomical location and large tumor often resulting in incomplete resection and high proliferative activity.

Adult↗

PubMed2004

Molecular genetic analyses of human NKG2C (KLRC2) gene deletion.

Human NKG2A, NKG2C and NKG2E genes are located on 12p13 in the NK gene complex. We recently identified deletion of NKG2C in a Japanese population. This study was performed to identify the breakpoint, and to examine the association of NKG2C deletion with susceptibility to rheumatoid arthritis and systemic lupus erythematosus. The location of the breakpoint was determined to be 1.5-1.8 kb telomeric from the 3' end of NKG2A by comparing sequences of the intergenic segments upstream and downstream of the NKG2C gene in the common haplotype with the intergenic sequence between NKG2A and NKG2E in the deletion haplotype. Based on this information, a genotyping system was developed. The frequency of NKG2C deletion haplotype was 20.2% in Japanese and 20.0% in Dutch populations. The frequency of homozygous deletion was 4.1% in Japanese and 3.8% in Dutch. Evidence for an association with rheumatic diseases was not detected. These results indicated that NKG2C deletion is commonly present in Japanese and Dutch, suggesting that NKG2C is not essential for survival and reproduction, and is not associated with rheumatic diseases.

Adult↗

PubMed2004

Mutational effects on O(6)-methylguanine-DNA methyltransferase from hyperthermophile: contribution of ion-pair network to protein thermostability.

Ion pairs have been considered to be general stabilizing factors in hyperthermophilic proteins, but the present experimental data cannot fully explain how ion pairs and ion-pair networks contribute to the stability. In this paper, we show experimental evidence that not all of the internal ion pairs contribute to the thermal and thermodynamic stability, using O(6)-methylguanine-DNA methyltransferase from Thermococcus kodakaraensis KOD1 (Tk-MGMT) as a model protein. Of three mutants in which an inter-helical ion pair was disrupted, only one mutant (E93A) was shown to be destabilized. Delta G of E93A was lower by approximately 4 kJ mol(-1) than that of the wild type, and E93A unfolded one order of magnitude faster than did the wild type and other variants. Glu 93 has unique properties in forming an ion-pair network that bridges the N- and C-terminal domains and connects three helices in the protein interior.

Amino Acids↗

PubMed2004

Relation of hypoxia-inducible factor-1alpha to vascular endothelial growth factor and vasoactive factors during healing of gastric ulcers.

We studied the relation of hypoxia-inducible factor-1alpha (HIF-1alpha) to vascular endothelial growth factor and vasoactive factors during the healing of gastric ulcers. The gastric ulcers were divided into three stages (active stage, healing stage and scar stage). The expression of HIF-1alpha, endothelin-1, inducible nitric oxide synthase, and vascular endothelial growth factor mRNA was highest during the active stage of ulcer healing, and endothelin-1, vascular endothelial growth factor protein levels and nitric oxide were higher during the healing stage. Thus, levels of HIF-1alpha mRNA tend to increase during the active stage of gastric ulcer healing, suggesting that this factor participates in the induction of endothelin-1, inducible nitric oxide synthase, and vascular endothelial growth factor. Also, the HIF-1alpha mRNA level did not differ significantly among the various stages of ulcer healing, and detectable levels of HIF-1alpha protein were not found during any stage. This suggests that these angiogenic factors and vasoactive substances may be induced by HIF-1alpha. During the active stage on endoscopic examination, considered the initial phase of ulcer healing, the process of ulcer healing has begun, and the tissue at the ulcer margin has already been reoxygenated.

Case-Control Studies↗

PubMed2004

Recurrent peptic ulcers in patients following successful Helicobacter pylori eradication: a multicenter study of 4940 patients.

OBJECTIVE: Although curative treatment of Helicobacter pylori infection markedly reduces the relapse of peptic ulcers, the details of the ulcers that do recur is not well characterized. The aim of this study is to describe the recurrence rate and specific features of peptic ulcers after cure of H. pylori infection. METHODS: This was a multicenter study involving 4940 peptic ulcer patients who were H. pylori negative after successful eradication treatment and were followed for up to 48 months. The annual incidence of ulcer relapse in H. pylori-cured patients, background of patients with relapsed ulcers, time to relapse, ulcer size, and site of relapsed ulcers were investigated. RESULTS: Crude peptic ulcer recurrence rate was 3.02% (149/4940). The annual recurrence rates of gastric, duodenal and gastroduodenal ulcer were 2.3%, 1.6%, and 1.6%, respectively. Exclusion of patients who took NSAIDs led annual recurrence rates to 1.9%, 1.5% and 1.3%, respectively. The recurrence rate was significantly higher in gastric ulcer. Recurrence rates of patients who smoked, consumed alcohol, and used NSAIDs were significantly higher in those with gastric ulcer recurrence compared to duodenal ulcer recurrence (e.g. 125 of 149 [83.9%] relapsed ulcers recurred at the same or adjacent sites as the previous ulcers). CONCLUSIONS: Curative treatment of H. pylori infection is useful in preventing ulcer recurrence. Gastric ulcer is more likely to relapse than duodenal ulcer. Recurrent ulcer tended to recur at the site of the original ulcers.

Alcohol Drinking↗

PubMed2004

Primary leiomyosarcoma of the vertebra: Case report and review of the literature.

A case of primary leiomyosarcoma of a thoracic vertebra associated with a compression fracture in a 75-year-old woman was preoperatively thought to be granulation tissue. Surgical decompression was performed and the histological and immunohistochemical studies established the diagnosis of leiomyosarcoma. Based on the clinical and radiological examinations, metastases were ruled out. Primary leiomyosarcoma of the vertebra is extremely rare and in that site it is considered to have a relatively poor prognosis.

Aged↗

PubMed2004

Reversal of acquired cisplatin resistance by modulation of metallothionein in transplanted murine tumors.

BACKGROUND: The platinum-based chemotherapeutic agent cisplatin is involved in a broad spectrum of activities against human systemic malignancies. However, acquired resistance to cisplatin reduces its clinical efficacy. Elucidation of the molecular basis of cisplatin resistance is required to improve the effectiveness of cisplatin. In the present study, the mechanism of acquired resistance to cisplatin was studied in C3H mice inoculated with MBT-2 murine bladder tumor cells. METHODS: C3H mice were subcutaneously inoculated with 1.0 x 10(6) MBT-2 cells/mouse on day 0. The mice were given intraperitoneal injections of 10 micro mol/kg cisplatin and subcutaneous injections of 1000 micro mol/kg propargylglycine, an inhibitor of gamma-cystathionase, once a day for 10 consecutive days from day 11 to day 20. RESULTS: The metallothionein content of the tumors was increased to twice the control level by repeated administration of cisplatin. Co-administration of propargylglycine reduced metallothionein induction in the tumors and markedly enhanced the antitumor activity of cisplatin. In contrast, the glutathione content in the tumors did not change from the control level after cisplatin administration. The platinum accumulation in tumors treated with cisplatin alone was 1.7-fold greater than when propargylglycine was administered concomitantly. The platinum concentrations changed in accordance with the metallothionein contents. CONCLUSIONS: These observations suggest that metallothionein, but not glutathione or reduced platinum accumulation, might play a role in the acquired resistance to cisplatin of C3H mice inoculated with MBT-2. Moreover, reversal of this resistance might be possible by biochemical modulation of metallothionein.

Alkynes↗

PubMed2004

Comparative study of novel endoluminal ultrasonography and conventional transurethral ultrasonography in staging of bladder cancer.

BACKGROUND: Recent advances in ultrasonic techniques have improved the image quality and diagnostic accuracy for staging of bladder cancer. The aim of this study was to assess the feasibility and usefulness of endoluminal ultrasonography (ELUS) in staging of bladder cancer, and to compare them with those of conventional transurethral ultrasonography (TUUS). METHODS: From 2000 to 2002, 19 patients with bladder cancer were evaluated by ELUS and TUUS before transurethral resection or biopsy. Clinical staging using ELUS, TUUS, computed tomography (CT) and magnetic resonance imaging (MRI) was compared with the results of pathological staging. RESULTS: In 16 of 19 patients, both ELUS and TUUS were able to diagnose tumor stage. In the remaining three patients, both methods were unable to evaluate stage of tumor. In two of these patients, this inability to evaluate tumor state was caused by a difficulty in depicting the tumor base in rectangular scanning. In the remaining patient, the inability to evaluate tumor stage was caused by a difficulty in recognizing the normal muscularis because of edema around the tumor base. Both diagnostic accuracies of ELUS and TUUS were 84%, which were superior to those of CT (44%) and MRI (82%). CONCLUSIONS: Endoluminal ultrasonography and TUUS were equally useful for staging diagnosis of bladder cancer. Because the ELUS probe is very small in diameter and can be manipulated under direct vision, it is superior to the TUUS in safety and in fine visualization. However, the main limitations of ELUS include an inability to evaluate the depth of invasion of large tumors and an inability to visualize the tumor base in the position of the bladder neck.

Aged↗

PubMed2004

Filtration leukocytapheresis therapy in the treatment of rheumatoid arthritis patients resistant to or failed with methotrexate.

Filtration leukocytapheresis (LCP) is a treatment for abnormal autoimmune states, which removes responsible leukocytes from the peripheral blood. To examine the efficacy of LCP therapy in the treatment of rheumatoid arthritis (RA), nine patients were selected, who were either resistant to methotrexate, or failed with methotrexate due to drug ineffectiveness or adverse side effects. For these patients, LCP therapy was performed once a week for five weeks. After five LCP treatments, the patients were observed for 12 weeks, to test the efficacy of the treatment. The definition of improvement given by the American College of Rheumatology (ACR core set) was used for efficacy evaluation of LCP therapy. As the result, 77.8% of the patients showed an ACR 20% response and 44.4% of the patients showed an ACR 50% response. With improvement of joint symptoms, IL-6 was significantly decreased at 8 weeks and 12 weeks after the treatment. The expression of adhesion molecules CD11a, CD11b, and CD18 on granulocytes decreased directly after the LCP treatment. No adverse side effect was monitored during the study period. These results indicates that LCP treatment is a useful treatment for RA patients who were resistant to methotrexate, or failed with methotrexate due to ineffectiveness or side effects of the drug.

Adult↗