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Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 109 records · Page 6Linked to original sources
PubMed2000

Suppressor T cells regulate the nonanergic cell population that remains after peripheral tolerance is induced to the Mls-1 antigen in T cell receptor Vbeta 8.1 transgenic mice.

We have found suppressor T cells that inhibit the proliferative response of naive CD4(+) T cells in T cell receptor (TCR) Vbeta8.1 transgenic mice rendered tolerant in vivo by inoculation of Mls-1(a)-positive cells. This suppression was mediated by CD4(+) T cells but not by CD8(+) T cells or double-negative (DN) cells, and splenic CD4(+) T cells from tolerant mice displayed a greater suppression than lymph node CD4(+) T cells. Cell contact was required for efficient suppression, and known inhibitory cytokines such as IL-4, IL-10, and transforming growth factor beta were not involved. Suppressor T cells inhibited IL-2 production by naive CD4(+) T cells, and the addition of exogenous IL-2 diminished the suppressed activity while having little activity on tolerant T cells. Suppression was abolished by the elimination of CD25(+) T cells in the tolerant CD4(+) T cell subset. CD25(+)CD4(+) T cells suppressed the proliferative response of the residual fraction of the nonanergic population, namely, 6C10(+)CD4(+) T cells still present in the tolerant mice. However, 6C10(-)CD4(+) T cells still had reduced reactivity to Mls-1(a) even after CD25(+)CD4(+) T cells were removed and exogenous IL-2 was added. Suppressor cells appear to affect only residual nonanergic cells in situ, thereby facilitating the maintenance of the unresponsive state in vivo. These data provide a framework for understanding suppressor T cells and explain the difficulties and variables in defining their activity in other systems, because suppressor T cells apparently control only a small population of nonanergic cells in the periphery and may be viewed as a homeostatic mechanism.

Animals↗
PubMed2000

Fatty acid 9- and 13-hydroperoxide lyases from cucumber.

Fatty acid hydroperoxide lyase (HPL) is a novel P-450 enzyme that cleaves fatty acid hydroperoxides to form short-chain aldehydes and oxo-acids. In cucumber seedlings, the activities of both fatty acid 9HPL and 13HPL could be detected. High 9HPL activity was especially evident in hypocotyls. Using a polymerase chain reaction-based cloning strategy, we isolated two HPL-related cDNAs from cucumber hypocotyls. One of them, C17, had a frameshift and it was apparently expressed from a pseudogene. After repairing the frameshift, the cDNA was successfully expressed in Escherichia coli as an active HPL with specificity for 13-hydroperoxides. The other clone, C15, showed higher sequence similarity to allene oxide synthase (AOS). This cDNA was also expressed in E. coli, and the recombinant enzyme was shown to act both on 9- and 13-hydroperoxides, with a preference for the former. By extensive product analyses, it was determined that the recombinant C15 enzyme has only HPL activity and no AOS activity, in spite of its higher sequence similarity to AOS.

Aldehyde-Lyases↗
PubMed2000

Tumor-specific CD4(+) suppressor T-cell clone capable of inhibiting rejection of syngeneic sarcoma in A/J mice.

Elimination of CD4(+) T cells by anti-CD4 antibody caused regression of a methylcholanthrene-induced S713a sarcoma growing in syngeneic A/J mice, and the tumor regression was essentially required for CD8(+) T cells. A CD4(+) T-cell clone, designated T595B1, was established to elucidate the characteristics of CD4(+) suppressor T cells. T595B1 expressed CD3, T-cell receptor (TCR)beta, TCR-Vbeta2, CD4, CD25, CD45RB, CD44, LFA-1, and ICAM-1 molecules on its cell surface and showed MHC class II I-E(k)-restricted tumor antigen-specific proliferation. T595B1 cells specifically suppressed in vitro CTL induction of S713a in a dose-dependent manner. Furthermore, culture supernatant of T595B1 cells also suppressed in vitro CTL induction, but its suppressive activity was not specific. Cytokine analyses revealed that T595B1 cells secreted IL-4, IL-5, IL-6, and IL-10 but not IFN-gamma, IL-2, TNF, or TGFbeta, indicating that this clone belongs to the so-called T helper 2 (Th2) type. However, the suppressive activity of the culture supernatant to the in vitro CTL induction was not abrogated by any neutralizing antibody to IL-4, IL-5, IL-6, IL-10, or TGF-beta. Repeated adoptive transfer of T595B1 cells into syngeneic immune mice entirely impaired their capacity to reject S713a sarcoma, resulting in progressive tumor growth in these mice.

Adoptive Transfer↗
PubMed2000

Synthesis and receptor sites of endothelin-1 in the rat liver vasculature.

Immunocytochemical localization of big endothelin-1 (big ET-1), ET-1, and ET receptor A and B (ET(A) and ET(B)), and gene expression of prepro ET-1 mRNA were examined on the rat liver vasculature. Immunoreactivities for big ET-1 and ET-1 were preferentially seen along the endothelium of interlobular veins (IV) and artery (IA), although the staining intensity was more pronounced in IV. Expression of preproET-1 mRNA was detected in both vascular endothelia and the signal intensity was more prevalent in IV. Immunoelectron microscopy showed that rough endoplasmic cisterns were immunoreactive for big ET-1, while Weibel-Palade (WP) bodies, a storage site for ET-1, were immunoreactive for ET-1 in endothelial cells of IV. These results indicate that endothelial cells of IV are the major site of synthesis of ET-1, which is extracellularly secreted by degranulation and/or exocytosis of WP bodies. Hepatic stellate cells (HSCs), especially of the plasma membrane of perisinusoidal and interhepatocellular processes, were immunoreactive for both ET(A) and ET(B) receptor antibodies. These findings suggest that ET-1 receptor-mediated HSC contraction is involved in the regulation of hepatic sinusoidal blood flow as previously cited in mammalian liver cirrhosis. We also showed that sarcolemma and caveoles in the smooth muscle cells of the media of IV, and its branches before reaching the hepatic sinusoids, were immunoreactive for ET(A) receptor antibody. The results suggest that such vessels, which contains a large amount of hepatic blood inflow, participate in pump mechanism toward hepatic sinusoidal circulation in a receptor-mediated paracrine fashion.

Animals↗
PubMed2000

Absence of association between a common mutation in the methylenetetrahydrofolate reductase gene and preeclampsia in Japanese women.

An association between preeclampsia (PE) and a common missense mutation of the methylenetetrahydrofolate reductase gene (MTHFR), a C to T substitution at nucleotide 677 (C677T), which converts an alanine to a valine residue, has been reported in Italian and Japanese populations. We examined 101 cases of hypertension in pregnancy (HP), including 73 cases of PE, and 215 normal pregnancy controls to confirm the association in Japanese women. No significant differences of the frequency of the T677 allele frequency or percentage of T677 homozygotes were detected among the various types of cases: HP (0.38, 12%, respectively), severe HP (0. 40, 12%), PE (0.38, 11%), severe PE (0.41, 11%), primiparous HP (0. 40, 12%), primiparous PE (0.44, 18%), nonelderly HP (0.39, 13%), nonelderly PE (0.40, 14%), nonobese HP (0.38, 12%), nonobese PE (0. 39, 10%), HP without homozygous T235 of the angiotensinogen gene (TT of AGT) (0.38, 15%), PE without TT of AGT (0.38, 15%), and controls (0.38, 15%). The results indicate that T677 of MTHFR may not be a risk factor for PE in Japanese population.

Adult↗
PubMed2000

Activation of NADPH oxidase in Alzheimer's disease brains.

The present study is the first to show that superoxide (O(-)(2)) forming NADPH oxidase is activated in Alzheimer's disease (AD) brains by demonstrating the marked translocation of the cytosolic factors p47-phox and p67-phox to the membrane. In conjunction with a recent in vitro study showing that amyloid beta activates O(-)(2) forming NADPH oxidase in microglia, where these phox proteins are localized in this study, the present results suggest that, in AD, NADPH oxidase is activated in microglia, resulting in the formation of reactive oxygen species which can be toxic to neighboring neurons in AD.

Aged↗
PubMed2000

A novel mutation of the McLeod syndrome gene in a Japanese family.

McLeod syndrome is a rare X-linked hematologic and neuromuscular disorder manifested by chorea, myopathy, cardiomyopathy, areflexia, hyperCKemia, and acanthocytosis. Only four mutations have been reported in the gene responsible for McLeod syndrome. We report a novel gene mutation in a Japanese family. Direct sequencing of the PCR-amplified genomic DNA revealed the mutation was a single C-nucleotide insertion at codon 151 in exon 2 of the XK gene, which resulted in a 3'-frameshift. Study of family members revealed that the patient's mother was a manifesting carrier heterozygous for this mutation.

DNA Mutational Analysis↗
PubMed2000

A multivariate analysis of blood vessel and lymph vessel invasion as predictors of ovarian and lymph node metastases in patients with cervical carcinoma.

BACKGROUND: To the authors' knowledge there are few available data regarding the influence of lymphovascular space invasion, which has been examined separately as two components (lymphatic vessel invasion [LVI] and blood vessel invasion [BVI]), in the metastasis of cervical carcinoma. METHODS: LVI and BVI, which include capillary vessel invasion, were reviewed retrospectively based on the histopathologic slides of 239 women with cervical carcinoma who were treated with radical hysterectomy. The correlation between lymph node and/or ovarian metastases and LVI, BVI, and other histopathologic factors was investigated by multiple logistic regression analysis. The influence of LVI and BVI on survival was examined by Cox regression analysis. RESULTS: The rate of incidence of LVI was higher than that of BVI in all stages of cervical carcinoma (P < 0.0001 for International Federation of Gynecology and Obstetrics Stage IB and Stage II disease and P < 0.05 for Stage III disease). The incidence rate of BVI increased as LVI became more prominent and there was a significant correlation between the two findings (P < 0.0001). BVI was more frequent in adenocarcinoma/adenosquamous carcinoma than in squamous cell carcinoma (P < 0.05). LVI (P < 0.0001) and parametrial invasion (P < 0.0001) were significantly related to lymph node metastasis on multivariate analysis. Conversely, BVI (P < 0.05) and parametrial invasion (P < 0.0025), as well as adenocarcinoma or adenosquamous carcinoma (P < 0.0005), were significantly related to ovarian metastasis on multivariate analysis. With regard to the prognostic significance of these components, it was found that BVI (hazards ratio [HR] = 2.0), ovarian metastasis (HR = 6.5), and lymph node metastasis (HR = 5.5) were significantly related to a poor prognosis in women with cervical carcinoma. CONCLUSIONS: Ovarian metastasis may occur via hematogenous spread of cervical carcinoma. The results of the current study suggest that BVI, including capillary vessels, that is diagnosed separately from LVI using hematoxylin and eosin stained sections may be an important prognostic factor for patients with cervical carcinoma.

Carcinoma, Adenosquamous↗
PubMed2000

Increase in phospholipase C-delta1 protein levels in aluminum-treated rat brains.

The effect of administration of aluminum to rats on the level of three phospholipase C (PLC) isozymes (beta1, gamma1, and delta1) was assessed in a variety of brain tissues. After exposure to aluminum, a statistically significant increase in malondialdehyde, an index of lipid peroxidation, was observed. In addition, there was a significant reduction in the catalytic activity of low molecular weight phosphotyrosine phosphatase, which loses its activity during oxidative stress. This suggests that oxidative stress is induced in brain tissues exposed to aluminum. The protein level of PLC-delta1, but not that of PLC-beta1 or -gamma1, was significantly increased in brains where oxidative stress had been induced. The total PLC activity in aluminum-treated rat brains was significantly higher than that in control brains. These results suggest that PLC-delta1 protein levels in brain tissues are increased by the induction of oxidative stress, giving an explanation for its up-regulation in Alzheimer's disease.

Aluminum↗
PubMed2000

Sustained enhancement of Ca(2+) influx by glibenclamide induces apoptosis in RINm5F cells.

Cytosolic Ca(2+) elevations are known to be involved in triggering apoptosis in many tissues, but the effect of sustained enhancement of Ca(2+) influx on apoptosis in beta cells remains unknown. We have found that the viability of RINm5F cells is decreased dose-dependently by continuous exposure to glibenclamide at concentrations from 10(-7) to 10(-4) M, and that this effect is partially ameliorated by pretreatment with cycloheximide. Electrophoresis of the cells exposed to glibenclamide revealed ladder-like fragmentation characteristic of apoptosis, and which also is suppressed by cycloheximide pretreatment. By using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, we detected increased DNA fragmentation in the nuclei of the cells exposed to glibenclamide, and staining with Hoechst 33342 and propidium iodide showed a dose-dependent increase in the number of cells with the chromatin condensation and fragmentation in their nuclei that is characteristic of apoptosis. The effects of glibenclamide on cell viability and apoptotic cell death were partially inhibited by treatment with Ca(2+) channel blocker, and by reducing the extracellular Ca(2+) concentration during glibenclamide exposure, suggesting that they may be derived from increased Ca(2+) influx. Furthermore, only the percentage of apoptotic cells, and not that of necrotic cells, increased with the increasing intracellular Ca(2+) concentration during glibenclamide exposure. In conclusion, we have demonstrated that the sustained enhancement of Ca(2+) influx caused by glibenclamide exposure can induce apoptotic cell death in a pure beta cell line.

Animals↗
PubMed2000

Expression of alpha-calcitonin gene-related peptide in the enteric nervous system of rat small intestine.

We first detected alpha-calcitonin gene-related peptide (alpha-CGRP) precursor mRNA in the enteric nervous system (ENS) of rat small intestine by reverse transcriptase polymerase chain reaction (RT-PCR). The nucleotide sequence of the RT-PCR product was completely identical to that found in other organs. By in situ hybridization using digoxygenin-labeled alpha-CGRP precursor cRNA probe, we found that antisense probes detected a signal on nerve cell bodies of both submucosal and myenteric plexuses. Our findings indicate that the rat ENS participates in synthesis of alpha-CGRP precursor.

Animals↗
PubMed2000

Novel mutation (E113X) of antithrombin III gene (AT3) in a woman with gestational recurrent thrombosis.

A 35-year-old Japanese woman with a low level (42-54%) of blood antithrombin (AT) III, experienced two induced abortions due to deep venous thrombosis at 8 weeks of gestation (GW) and cerebral thrombosis at 10 GW. The present pregnancy was successfully managed with intravenous administration of AT III (6,000-8,000 U/wk). Analysis of polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) for exons 3A and 4 of the AT III gene (AT3) using her DNA revealed extra expansion bands with altered migration. The DNA sequencing demonstrated novel mutations in exon 3A of AT3: a G to T substitution at nucleotide position 5333 in codon GAG for Glu 113, causing a stop codon (E113X), and an A to T substitution at position 5338 in codon AAA for Lys 114, forming Asn (K114N). These novel mutations, especially E113X, in AT3 may be related to recurrent thrombosis in the pregnancy.

Abortion, Induced↗
PubMed2000

PCR diagnosis of X-linked ichthyosis: identification of a novel mutation (E560P) of the steroid sulfatase gene.

X-linked ichthyosis (XLI) is an inherited skin disorder due to deficiency of steroid sulfatase (STS) activity. XLI has been diagnosed by assaying STS activity in placenta or lymphocytes of patients after birth. Most patients have a large deletion of the STS gene, generated by inaccurate recombination at the STS locus. However, point mutations in the STS gene have been reported in some patients with complete STS deficiency. In a new case of STS deficiency, we identified an STS missense mutation, Glu560Pro or E560P. This new point mutation suggests that the C-terminal region of the STS enzyme is important for STS enzymatic function. Hum Mutat 15:296, 2000.

Amino Acid Substitution↗
PubMed2000

Inactivation of the human androgen receptor gene is associated with CpG hypermethylation in uterine endometrial cancer.

Androgens mediate their effects through the androgen receptor (AR) and have antiproliferative effects on uterine endometrial cells. In this report, we investigated methylation status and the expression of the AR gene in normal endometrium and uterine endometrial cancer (UEC) tissues using methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining. Seventy of 89 cancer samples were AR negative, although 39 of 46 normal samples were AR positive by immunohistochemistry. By MSP, 64 of 89 cancer samples showed only methylated AR alleles, although all normal tissues showed both unmethylated and methylated AR alleles. To determine whether similar changes occurred in methylation status in the UEC carcinogenesis, we studied AR methylation using pairs of cancerous and normal samples from 28 patients. Twenty-three of 28 cancer samples showed only methylated AR alleles, although all normal samples showed both unmethylated and methylated alleles. All of the 23 cancer samples that lost unmethylated alleles were negative for AR by immunohistochemical analysis. Reverse transcription-polymerase chain reaction was performed by using UEC cell lines with and without treatment by the demethylating reagent 5-aza-2'-deoxycytidine. No AR expression was found in any of the UEC cell lines, except for MFE-296 without 5-aza-2'-deoxycytidine. Treatment with 5-aza-2'-deoxycytidine restored AR expression in all of the UEC cell lines that showed no AR expression before treatment. This study is the first to report that the possible mechanism of AR inactivation in endometrial cancer is through hypermethylation of the AR gene CpG islands.

Alleles↗
PubMed2000

Expression of matrix metalloproteinases and related tissue inhibitors in the cyst fluids of ovarian mucinous neoplasms.

OBJECTIVES AND METHODS: The growth of an ovarian cystic neoplasm often involves its invasion into and destruction of the extracellular matrix. We examined neoplastic cysts of ovarian mucinous tumors for the presence of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) using zymography (in situ zymography, gelatin zymography, and casein zymography) and enzyme-linked immunosorbent assay. RESULTS: Matriolytic activity was detected within the cystic contents and cytoplasm of the lining epithelial cells of the cyst by in situ zymography. This intracystic matriolytic activity was thought to originate mainly in the epithelial cells. The activated form of MMP-9 was seen in all carcinoma and borderline fluids and in 7 of 15 adenomas. The concentration of MMP-9 was higher in carcinoma fluids than in borderline and adenoma fluids (P < 0.05). TIMP-1, which specifically binds to MMP-9, was also higher in carcinoma and borderline fluids than in adenoma fluids (P < 0.05). MMP-2 activity was nearly ubiquitously present in all cyst fluids, irrespective of the fluid's histologic category. The amount of MMP-2 was highest in the carcinoma category, although not to a statistically significant degree. TIMP-2, a specific inhibitor for MMP-2, was significantly lower in the borderline category than in the adenoma category. The molar ratios of TIMP-1/MMP-9 (not significant) and TIMP-2/MMP-2 (P < 0.05) were higher in the adenoma category. Expressions of trypsin, MMP-7, and MMP-9 were generally higher in carcinoma and borderline fluids than in adenoma fluids. CONCLUSIONS: These observations indicate the importance of ovarian cystic fluids for analyzing tumor-associated matriolytic activities. The findings suggest that these matriolytic enzymes, together with the presence of their inhibitors, play an important role in the growth of ovarian mucinous tumors.

Adenocarcinoma, Mucinous↗
PubMed2000

Prognostic significance of lymph node metastasis and clear cell histology in ovarian carcinoma limited to the pelvis (pT1M0 and pT2M0).

BACKGROUND: The prognostic significance of lymph node (LN) metastasis in clinically early-stage (pT1M0 or pT2M0) ovarian carcinoma has not yet been fully elucidated. METHODS: From 1988 to 1997, 94 patients with ovarian carcinoma of pT1M0 (n = 78) or pT2M0 (n = 16) classification underwent surgery including systematic pelvic and paraaortic LN dissection. We investigated the prognostic factors of intraperitoneally determined early-stage ovarian carcinoma focusing on LN metastasis. RESULTS: LN metastasis was seen in 5.1% of pT1M0 and in 31.3% of pT2M0 tumors. Univariate analysis of grade, histology (clear cell vs others), size of primary tumor, peritoneal cytology, and LN metastasis revealed that histology (P < 0.01), size of tumor (P < 0.05), and LN metastasis (P < 0.0005) were related to patient survival of early-stage ovarian carcinoma. Peritoneal cytology (P = 0.053) and grade (P = 0.059) had marginal statistical significance. A multivariate Cox regression analysis showed that clear cell histology (P < 0.05) and LN metastasis (P < 0. 005) are significant independent prognosticators of patient survival. Three (two with clear cell adenocarcinoma and one with mucinous adenocarcinoma) of nine patients with LN metastasis had died of the disease by the time of the present analysis. Two of the three deceased patients had recurrent tumors in distant organs (bone and brain/liver), one had pleural and peritoneal carcinomatosis, and no patients had retroperitoneal recurrence. This suggests that LN metastasis indicates that tumor cells may have already spread systemically at the time of treatment and, at the same time, retroperitoneal lymph node dissection (RPLND) may be effective in eradicating retroperitoneal metastasis in some instances of ovarian carcinoma. CONCLUSION: Clear cell histology and LN metastasis are indicators of poor prognosis for patients with tumors limited to the pelvis. Therapeutic significance of systematic RPLND for pT1M0/pT2M0 ovarian carcinomas needs to be further investigated by randomized studies.

Adenocarcinoma, Clear Cell↗
PubMed2000

Two cases of endometrial cancer meeting new clinical criteria for hereditary nonpolyposis colorectal cancer.

BACKGROUND: New clinical criteria for hereditary nonpolyposis colorectal cancer (HNPCC) that includes extracolonic cancers were recently proposed. We present 2 endometrial cancer patients who met the new criteria of 161 endometrial cancer patients. CASE REPORTS: Case 1: A 55-year-old female was operated on for synchronous double primary cancers of the endometrium and rectum. She had also undergone an operation for metachronous ascending colon cancer at the age of 44. She had five relatives with a history of colorectal cancer. The rectal cancer tissue revealed no microsatellite instability (MSI). Case 2: A 48-year-old female underwent a radical operation for synchronous double primary cancers of the endometrium and ovaries. She had three relatives with a history of colorectal cancer. The endometrial cancer tissue showed high MSI. CONCLUSIONS: The frequency of endometrial cancer patients meeting the new HNPCC criteria was 1.2% (2/161). These are the first case reports selected from consecutive endometrial cancer patients.

Carcinoma, Endometrioid↗