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Biomedical subjects

T Fujimura

Publications and source records attributed to T Fujimura.

At least 55 records · Page 3Linked to original sources
PubMed1997

Lack of association of polymorphisms of the angiotensin converting enzyme and angiotensinogen genes with nonfamilial hypertrophic or dilated cardiomyopathy.

Although several genes or genetic loci that are either responsible for or confer susceptibility to familial hypertrophic cardiomyopathy (HCM) or dilated cardiomyopathy (DCM) have been identified, genetic defects that underlie nonfamilial HCM or DCM remain to be characterized. An allelic association study for the angiotensin converting enzyme (ACE) and angiotensinogen genes has now been performed with 71 patients with nonfamilial HCM, 88 patients with nonfamilial DCM, and 122 healthy control subjects in the Japanese population. The distribution of ACE genotypes for an insertion/deletion (I/D) polymorphism in intron 16 did not differ significantly among control subjects and patients with HCM or DCM. Similarly, the distributions of angiotensinogen genotypes for methionine-235-threonine (M235T) and threonine-174-methionine (T174M) polymorphisms did not differ significantly among the three groups. Echocardiographic parameters that are indicators of the severity or progression of disease did not differ significantly among ACE I/D or angiotensinogen M235T and T174M genotypes in the two patient groups. Finally, no additive or synergistic effect of any combined genotypes or haplotypes of the ACE and angiotensinogen polymorphisms on the association with HCM or DCM was detected. Results indicate that the ACE I/D and angiotensinogen M235T and T174M polymorphisms are not related to HCM or DCM in the Japanese population, and that variants of these polymorphisms do not contribute to the genesis or progression of these cardiomyopathies.

Angiotensinogen↗
PubMed1997

Lack of association of angiotensin converting enzyme gene polymorphism or serum enzyme activity with coronary artery disease in Japanese subjects.

The association of an insertion/deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene or the serum activity of ACE with coronary artery disease (CAD) was investigated in Japanese men and women. The ACE genotype of 947 CAD subjects who underwent coronary angiography and of 893 control subjects was determined by polymerase chain reaction analysis. No association of the DD genotype or the D allele with CAD was observed in men or women. In a low risk group (defined by a body mass index below the median value and the absence of a history of hypertension, diabetes mellitus, and hypercholesterolemia), there was also no association between the ACE gene polymorphism and CAD. No significant difference in serum ACE activity was detected between CAD subjects and controls of all genotypes or of the same genotype, whereas a significant association was apparent between serum ACE activity and ACE genotype for both CAD subjects and controls among both men and women. These results indicate that the ACE I/D polymorphism and genotype associated variation in serum ACE activity are not risk factors for CAD in Japanese men or women.

Adult↗
PubMed1997

Structure, chromosomal location and expression of a rice gene encoding the microsome omega-3 fatty acid desaturase.

The omega-3 fatty acid desaturases are membrane-bound enzymes catalyzing the conversion of linoleic acid to linolenic acid in lipids, and are located both in the microsome and plastid envelopes as two different isoforms. A cDNA encoding the microsome omega-3 fatty acid desaturase (OsFAD3) and the corresponding genomic clone were isolated from rice (Oryza sativa L.). The OsFAD3 gene was composed of 8 exons and 7 introns. A microsatellite was present in the second exon of the OsFAD3 gene, showing polymorphism between Indica and Japonica rice varieties. The mapping of this microsatellite showed that the OsFAD3 gene was located on chromosome 11. Expression of the OsFAD3 cDNA in tobacco hairy root tissues and subsequent analysis of fatty acid compositions demonstrated the activity of the microsome omega-3 fatty acid desaturase. The OsFAD3 mRNA was abundant in root tissues, but was hardly detectable in leaves. In root tissues, a high level of the OsFAD3 mRNA was observed at 15 degrees C and 20 degrees C, with its level decreasing markedly at temperatures below 10 degrees C. The accumulation of the OsFAD3 mRNA in leaf tissues remained at quite low levels, both at normal growth temperatures and at chilling temperatures. Similar temperature responses of the OsFAD3 gene were observed both in chilling- tolerant and in chilling-intolerant rice cultivars.

Chromosome Mapping↗
PubMed1997

Molecular cloning of a pig homologue of membrane cofactor protein (CD46).

Organs of transgenic pigs that express human complement regulatory proteins are under assessment as an alternative to transplantation. A major barrier to the transplantation of pig organs is the hyperacute rejection caused by pre-existing antibodies and complement. Pig cells are very susceptible to human complement, presumably because pig cell-surface complement regulatory proteins are inefficient against it. Expression of human complement regulatory proteins, such as decay-accelerating factor and membrane cofactor proteins (MCP or CD46), by means of transgenes would confer resistance to human complement upon pig cells, thereby preventing hyperacute rejection. To express sufficient levels of human complement regulatory proteins at appropriate sites, regulatory elements of genes of pig membrane-bound complement regulatory proteins would be useful. To obtain their cDNAs, we transfected human cells with a pig cDNA library, selected cells by incubation with pig complement and rescued the plasmids. We cloned a cDNA for the pig homologue of MCP, pMCP. The cDNA encoded a predicted protein of 363 amino acids with 42% amino acid identity with human MCP. The pMCP consisted of four short consensus repeats, a Ser/Thr/Pro-rich domain, and transmembrane and cytoplasmic domains. Recombinant soluble pMCP that lacked transmembrane and cytoplasmic domains had factor I cofactor activity in C3b cleavage, indicating that it is functionally, as well as structurally homologous to MCP. FACS analysis with anti-pMCP mAb demonstrated that pMCP is expressed on all blood leukocytes, erythrocytes, and on endothelial and epithelial cell lines.

Amino Acid Sequence↗
PubMed1997

Increase of methicillin resistance in Staphylococcus aureus caused by deletion of a gene whose product is homologous to lytic enzymes.

A spontaneous high-level methicillin-resistant mutant, SRM1648, for which the MIC of methicillin is 1,600 microg/ml, was isolated on a plate containing 400 microg of the antibiotic/ml on which had been cultured the low-level methicillin-resistant Staphylococcus aureus SR17238, for which the MIC is 6.3 microg/ml. Analysis of the chromosomal DNAs of the mutant and the parental strains by the restriction landmark genomic scanning method with two-dimensional electrophoresis of restriction fragments revealed a 1.6-kb deletion in the chromosome of the mutant. The HindIII fragment of 2.5 kb containing this deleted region was cloned into a plasmid vector and introduced into the parental strain. A deletion mutant reconstructed in the presence of a low concentration of methicillin by integration and excision of the recombinant plasmid exhibited a high level of resistance (methicillin MIC, 1,600 microg/ml), confirming that the deletion had caused the elevation of the resistance level. Sequence analysis indicated that the deletion occurred in three consecutive open reading frames (ORFs). The predicted amino acid sequence of the first ORF showed high homology with both RelA and SpoT of Escherichia coli, which are involved in the synthesis and hydrolysis of guanosine 5',3'-polyphosphate, and that of the third ORF showed a relatively high homology to the lytic enzyme encoded by the lytC gene of Bacillus subtilis. We also isolated another high-level resistant mutant with a deletion within the third ORF, which suggested that inactivation of some lytic enzyme resulted in the increased resistance.

Amino Acid Sequence↗
PubMed1997

Diversity in distribution of Na+.K+ATPase of the choroid epithelium of prenatal rats; an immunocytochemical study.

The differentiating choroid plexus in rats at ages ranging from prenatal day 16 to postnatal day 3 was investigated with a special emphasis on the immunolocalization of Na+.K+ATPase in the choroid epithelium and neocapillarization of the choroid stroma. Immunoreactions for Na+.K+ATPase were localized on the apical plasma membrane of the simple choroid epithelium throughout the stages examined, but it also appeared on the basolateral plasma membrane till prenatal day 18, prior to the formation of the tight junctions as seen from both a marker experiment using lanthanum chloride and immunoreactions for tight junction-associated protein (ZO-1). This suggests that a polarity of the enzyme localization to the apical plasma membrane may take place after the establishment of the blood-cerebrospinal fluid barrier. Mesenchymal cells in the choroid stroma immunoreacted to the laminin antibody and occasionally contacted each other--forming solid cell cords--or endothelial cells of the preexisting capillaries. The contact areas immunoreacted to this antibody. Since there were few or no mitotic figures of the endothelial cells, the involvement of laminin in a mechanical linkage between the adjacent vasoformative mesenchymal cells as well as the endothelial lining in a manner suggestive of vasculogenesis was indicated.

Animals↗
PubMed1997

RNA-dependent RNA polymerase activity associated with the yeast viral p91/20S RNA ribonucleoprotein complex.

20S RNA is a noninfectious viral single-stranded RNA found in most laboratory strains of the yeast Saccharomyces cerevisiae. 20S RNA encodes a protein of 91 kDa (p91) that contains the common motifs found among RNA-dependent RNA polymerases from RNA viruses. p91 and 20S RNA are noncovalently associated in vivo, forming a ribonucleoprotein complex. We detected an RNA polymerase activity in p91/20S RNA complexes isolated by high-speed centrifugation. The activity was not inhibited by actinomycin D nor alpha-amanitin. The majority of the in vitro products was 20S RNA and the rest was the complementary strands of 20S RNA. Because the extracts were prepared from cells accumulating 20S RNA over its complementary strands, these in vitro products reflect the corresponding activities in vivo. When the p91/20S RNA complexes were subjected to sucrose gradient centrifugation, the polymerase activity cosedimented with the complexes. Furthermore, an RNA polymerase activity was detected in the complex by an antibody-linked polymerase assay using anti-p91 antiserum, suggesting that p91 is present in the active RNA polymerase machinery. These results together indicate that p91 is the RNA-dependent RNA polymerase or a subunit thereof responsible for 20S RNA replication.

Amanitins↗
PubMed1997

Cytokine gene expression in the foot pad and spleen of BALB/cAJcl mice infected with M. leprae.

The cytokine mRNAs expressed in the foot pads and spleens of BALB/cAJcl mice infected with Mycobacterium leprae were studied by the reverse transcriptase-polymerase chain reaction (RT-PCR) method using cytokine-specific primers for interleukin-1 alpha (IL-1 alpha), -2, -4, -6, -10, -12-(p40), gamma interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and TNF-beta, and then for CD4 and CD8 markers. The pattern of cytokine gene expression in the foot pad which supports M. leprae growth was different from the expression in the spleen which does not permit M. leprae multiplication in mice. Before BALB/cAjcl mice were infected with M. leprae, IL-1 alpha and TNF-beta mRNAs were expressed physiologically in the foot pad while all of the cytokine genes examined were expressed in the spleen. In the foot pads of mice inoculated with M. leprae, in addition to the physiological appearance of IL-1 alpha and TNF-beta mRNAs, these signals were intensified. TNF-alpha expression was induced by the infection. On the other hand, in the spleens of mice inoculated with M. leprae, CD4 mRNA expression disappeared on day 1 of the infection, which was accompanied by the reduced expression of IL-2, -4, -6, and -12 mRNAs. The recovery of CD4 mRNA expression at a latter stage was accompanied by a corresponding increase of the cytokine mRNA expression. It was suspected that these results might permit restricted growth of M. leprae in the foot pads of normal mice. Furthermore, our study suggests that tissue-specific, local, immunologic characteristics are important in M. leprae growth.

Animals↗
PubMed1997

[Alteration of p15 and p16 gene in gastric cancer].

We analyzed p15 and p16 gene alterations in gastric cancer. Only MKN45 showed both homozygous deletions but other cell lines and all of tumor specimens did not show any alterations. Using RT-PCR analysis, decreased or no expression of the p16 gene was found in 1 of 7 cell lines (except MKN45) (14.2%) and in 8 of 20 tumors (40%), whereas no abnormalities of p15 gene expression were found. These results suggest that the p16 gene may correlate with tumorigenesis and tumor expansion due to decrease or loss of gene products in gastric cancer.

Adenocarcinoma↗
PubMed1997

Depressed mechanoenergetics and compensatory responses in idiopathic dilated cardiomyopathy.

The aim of this study was to clarify that the depressed mechanoenergetics in patients with idiopathic dilated cardiomyopathy (DCM) resulted from compensation for the decreased contractility. The study population consisted of eight control subjects, with normal left ventricular size and ejection fraction and 31 patients with DCM. Left ventricular end-systolic elastance (Ees), effective arterial elastance (Ea), external work (EW), and the pressure-volume area (PVA) were measured, using a dual-field volume conductance catheter equipped with a micromanometer-tipped catheter. Ea/Ees was evaluated as ventriculoarterial coupling. Normal hearts worked at almost optimal condition (defined as Ea/Ees = 1/2), while ventriculoarterial coupling was far from the optimum (Ea > Ees) in patients with DCM. Ees in patients with DCM was less than that in control subjects; however, Ea was similar in the two groups. The mismatch of Ea/Ees observed in DCM leads to depressed mechanoenergetics as a result of the compensatory response to maintain adequate blood pressure. Volume enlargement plays an important role in maintaining adequate blood pressure and cardiac output in the course of chronic deterioration of contractility.

Blood Pressure↗
PubMed1996

Reduction of 14-16 kDa allergenic proteins in transgenic rice plants by antisense gene.

An antisense gene strategy was applied to suppress the 14-16 kDa allergen gene expression in maturing rice seeds. Gene constructs producing antisense RNAs of the 16 kDa allergen under the control of some rice seed-specific promoters were introduced into rice by electroporation. Immunoblot and RNA blot analyses of the seeds from the transgenic rice plants using the allergen-specific monoclonal antibody and a sequence-specific antisense RNA probe demonstrated that the 14-16 kDa allergen proteins and their transcripts of the seeds from several transgenic lines were present in much lower in amounts than those of the seeds from parental wild-type rice. The high levels of reduction observed were stably inherited in at least three generations.

Allergens↗
PubMed1996

Activation of Xenopus eggs by RGD-containing peptides accompanied by intracellular Ca2+ release.

To investigate the mechanism of egg activation in Xenopus, unfertilized eggs were treated with various oligopeptides related to the RGD sequence-containing peptides. When dejellied eggs were treated with RGDS at concentrations higher than 250 microM, the eggs produced a positive-going activation potential concomitant with intracellular Ca2- release. The eggs underwent cortical granule breakdown, cortical contraction, and resumption of meiosis. The activation by RGDS was independent of the voltage of egg membranes. GRGD, GRGDTP, and RGPFPI caused activation in some eggs, but RGES, RFDS, GPRP amide, and GPA did not. Denuded eggs were activated by Sepharose beads bound to RGDS, indicating an interaction of the RGD sequence with receptor molecules on the egg plasma membrane. The activation by RGDS did not occur under a Ca(2+)- and Mg(2+)-free condition, but occurred in a Ca(2+)-free solution containing Mg2+, concomitant with an intracellular Ca2+ release. These results indicate that a receptor of the RGD sequence on egg plasma membrane causes egg activation through an intracellular signal transduction system. A sperm agonist including the RGD sequence may play an important role in egg activation through the egg membrane receptor during the normal fertilization process.

Amino Acid Sequence↗
PubMed1996

Cytokine messenger RNA expression in the labial salivary glands of patients with Sjögren's syndrome.

OBJECTIVE: To characterize the initiation and progress of localized autoimmune damage in Sjögren's syndrome (SS), an autoimmune disease that is also considered to be a lymphoaggressive disorder, by examining the pattern of cytokine production at the site of autoimmune damage. METHODS: Using a polymerase chain reaction-based method, cytokine messenger RNA (mRNA) expression in the labial salivary glands of 15 patients with SS was investigated. In addition, the infiltrating lymphocytes in the labial salivary glands were examined immunohistochemically. RESULTS: Messenger RNAs of Th1 cytokines, such as interleukin-2 (IL-2) and interferon-gamma, were consistently detected in all patients, while Th2 cytokine mRNAs, such as IL-4 and IL-5, were detected in some cases, in association with strong B cell accumulation in the labial salivary glands. Other cytokine mRNAs produced by a variety of cell types, including IL-10, IL-6, and transforming growth factor beta (TGF beta), were also consistently detected in all patients, while IL-12 mRNA was detected in some of the patients. CONCLUSION: These results suggest that Th1 cytokines, as well as IL-10, IL-6, and TGF beta, are essential in the induction and/or maintenance of SS, while Th2 cytokines are involved in the progression of the disease process, especially local B cell activation.

Adult↗
PubMed1996

Studies on the mechanism of early onset macular degeneration in cynomolgus monkeys. II. Suppression of metallothionein synthesis in the retina in oxidative stress.

Initial investigations done in this laboratory detected increased albumin and decreased glyceraldehyde 3-phosphate dehydrogenase concentrations in the retina of an animal model manifesting early onset macular degeneration. Both glyceraldehyde 3-phosphate dehydrogenase and albumin are markers of oxidative stress in cells. In this study, we used the same animal model to study further biochemical and physiological processes which may be involved in the pathogenesis of early onset macular degeneration in monkeys. We detected 60% lower catalase and glutathione peroxidase activities in the affected retinas suggesting lower antioxidant activities and oxidative stress. One of the consequences of oxidative stress is the production of metallothionein, a low molecular weight protein also induced by high concentrations of heavy metals such as zinc. Metallothionein was detected by RT-PCR in these monkey retinas. However initial quantitative PCR studies on this protein showed that the synthesis of metallothionein in affected retinas appears to be less than in normal controls. The affected retinas also showed a fourfold lower zinc concentration compared with the normal controls. No significant difference, however, could be detected in the zinc concentrations in plasma samples. Since induction of metallothionein synthesis is mediated by transcription factors which require heavy metals such as zinc for binding to specific sites in the DNA, the lowered zinc concentration may, thus, correlate with the lowered metallothionein expression. And since metallothionein is suggested to function as a free radical scavenger, the lowered metallothionein synthesis may consequently contribute to increased peroxidation reactions in the affected retinas. It appears therefore, that oxidative stress and the decreased metallothionein synthesis may be involved in the pathogenesis of early onset macular degeneration in this animal model.

Amino Acid Sequence↗
PubMed1996

Prognostic relevance of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitors PAI-1 and PAI-2 in gastric cancer.

Expression of urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2) was evaluated in 125 surgically resected gastric cancers by immunohistochemical analysis. Tissue was stained immunohistochemically with a monoclonal antibody against human uPA and monoclonal antibodies against human PAI-1 and PAI-2. In addition, DNA ploidy patterns were determined by cytofluorometer after staining with propidium iodide. We found that 82 (66%) of the 125 gastric cancers expressed uPA as diffuse cytoplasmic staining, as intensely outlined luminal borders. PAI-1 expression was observed in 62 (50%) of 125 gastric cancer as a fine, diffuse and granular pattern in the cytoplasm. PAI-2 expression was observed in 65 (52%) of the 125 gastric cancers as a diffuse cytoplasmic staining. uPA-positive tumours showed a higher incidence of infiltration, lymph node metastasis and peritoneal dissemination that uPA-negative ones. Patients with uPA-positive tumours proved to have a significantly poorer prognosis than those with negative ones. PAI-1-negative tumours showed a higher incidence of liver metastasis and carried a poorer prognosis than PAI-1-positive ones. There was no significant correlation between uPA or PAI-1 expression and DNA ploidy patterns. Conversely, there was no significant relationship between PAI-2 expression and clinicopathological parameters and prognosis. According to the expression of uPA and PAI-1 status, groups of 19 uPA(-)/PAI-1(-), 44 uPA(+)/PAI-1(-), 23 uPA(-)/PAI-1(+) and 39 uPA(+)/PAI-1(+) were subdivided. Tumours with uPA(+)/PAI-1(-) had a significantly higher incidence of liver metastasis, lymph node metastasis and serosal invasion than the other groups of tumours. Patients with uPA(+)/PAI-1(-) tumours had a significantly poorer prognosis than those with uPA(-)/PAI-1(+) tumours. These results indicate that uPA expression is a useful biological prognostic indicator, and that uPA expression is a useful biological prognostic indicator, and that uPA and PAI-1 may play an important part in the tumour progression and metastasis in gastric cancer.

Adult↗
PubMed1996

Near-hexaploid Ph-positive acute myeloid leukemia with major-BCR/ABL transcript.

We describe the first case of acute myeloid leukemia (AML) with a Philadelphia (Ph) translocation and a near-hexaploid range chromosome number, whose leukemic cells had the major-BCR/ABL transcript. The genesis of near-hexaploid leukemic cells might be due to endoreduplication of triploid leukemic cells with the Ph, since the relapsed leukemic cells had triploid range chromosomes with double Ph chromosomes.

Aneuploidy↗
PubMed1996

Effects of intraoperative chemohyperthermia in patients with gastric cancer with peritoneal dissemination.

BACKGROUND: The most common cause of noncurative resection and recurrence is gastric cancer is peritoneal seeding. However, the results of treatment of peritoneal dissemination with chemotherapy have been poor with 5-year survival rates of 0%. METHODS: A new in vitro thermochemosensitivity test was performed on gastric cancer cells obtained from 19 surgically resected specimens by using tetrazolium-based colorimetric assay (MTT assay). A novel treatment of the intraoperative chemohyperthermia was undertaken in 83 patients with gastric cancer with peritoneal dissemination. After aggressive resection of primary tumor, lymph nodes, and peritoneal metastases, warmed saline solution containing mitomycin C 30 mg, etoposide 150 mg, and cisplatin 300 mg was introduced into the peritoneal cavity via a closed circuit continuous hyperthermic peritoneal perfusion (CHPP) for 60 minutes to keep the abdominal temperature at 42 degree to 43 degrees C by means of a heat exchange mechanism. RESULTS: The in vitro thermochemosensitivity test that 43 degrees C enhanced the cytotoxin effects on gastric cancer cells under clinically achievable drug concentrations. During CHPP, drug concentrations of cisplatin, mitomycin C, and etoposide in the perfusate remained statistically higher than in the peripheral venous circulation. Among 43 evaluable patients with residual peritoneal seeding, eight (19%) and nine (21%) exhibited complete response and partial response, respectively. The overall 1- and 5-year survival rates were 43% and 11%, respectively. Patients who underwent complete resection survived significantly longer than those with residual disease, and those with complete response had a significantly better prognosis than did those with partial response, and nonresponders. One-year survival rates with complete response, partial response or nonresponders were 88%, 27% and 22%, respectively. Five patients survived longer than 5 years. CONCLUSIONS: Our triple treatment combining surgery and CHPP is an effective therapy for selected patients with gastric cancer with peritoneal dissemination.

Adult↗