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Biomedical subjects

K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 127 records · Page 7Linked to original sources
PubMed2000

[Electrocardiographic findings in pulmonary thromboembolism--comparison with lung perfusion scan and echocardiographic findings].

This study investigated the usefulness of electrocardiography (ECG) in pulmonary thromboembolism (PTE), compared with lung perfusion scan and echocardigraphic findings on evaluation of the severity. We checked ECG findings associated with PTE at hospital admission, with the seven abnormal findings described by Sreeram N, et al. On Lung perfusion scan, severity of perfusion defect was assessed total defect score (TDS), calculated as the sum of the scores for all 18 segment of lung. On echocardiography, severity of right ventricular overload was assessed. The number of the seven ECG abnormal findings and TDS were larger in patients with the right ventricular overload (p < 0.01). The number of the ECG findings was positively correlated with TDS (r = 0.75). The number of abnormal ECG findings in PTE is associated with the severity evaluated by lung perfusion scan and echocardiography.

Aged↗
PubMed1999

Acid-labile ATP and/or ADP/P(i) binding to the tetraprotomeric form of Na/K-ATPase accompanying catalytic phosphorylation-dephosphorylation cycle.

The Na/K-ATPase has been shown to bind 1 and 0.5 mol of (32)P/mol of alpha-chain in the presence [gamma-(32)P]ATP and [alpha-(32)P]ATP, respectively, accompanied by a maximum accumulation of 0.5 mol of ADP-sensitive phosphoenzyme (NaE1P) and potassium-sensitive phosphoenzyme (E2P). The former accumulation was followed by the slow constant liberation of P(i), but the latter was accompanied with a rapid approximately 0.25 mol of acid-labile P(i) burst. The rubidium (potassium congener)-occluded enzyme (approximately 1.7 mol of rubidium/mol of alpha-chain) completely lost rubidium on the addition of sodium + magnesium. Further addition of approximately 100 microM [gamma-(32)P]ATP and [alpha-(32)P]ATP, both induced 0.5 mol of (32)P-ATP binding to the enzyme and caused accumulation of approximately 1 mol of rubidium/mol of alpha-chain, accompanied by a rapid approximately 0.5 mol of P(i) burst with no detectable phosphoenzyme under steady state conditions. Electron microscopy of rotary-shadowed soluble and membrane-bound Na/K-ATPases and an antibody-Na/K-ATPase complex, indicated the presence of tetraprotomeric structures (alphabeta)(4). These and other data suggest that Na/K-ATP hydrolysis occurs via four parallel paths, the sequential appearance of (NaE1P:E.ATP)(2), (E2P:E.ATP:E2P:E. ADP/P(i)), and (KE2:E.ADP/P(i))(2), each of which has been previously referred to as NaE1P, E2P, and KE2, respectively.

Adenosine Diphosphate↗
PubMed1999

Suppression of solid tumor growth by a monoclonal antibody against tumor vasculature in rats: involvement of intravascular thrombosis and fibrinogenesis.

We have reported that immunization of rat tumor-derived endothelial cells (TEC) isolated from KMT-17 solid tumors results in the generation of several monoclonal antibodies (MAbs). TES-23, one of these MAbs, recognizes a naturally occurring 80-kDa antigen expressed on endothelial cells of tumor blood vessels. To determine whether such MAbs can suppress solid tumor growth in vivo by impairment of endothelial cells in tumors following direct binding, we tested the biodistribution of (125)I-labeled TES-23 in rats bearing KMT-17 solid tumors. We also examined the effect of treatment using unconjugated TES-23 on tumor growth and histo-pathological changes in tumor tissues. Biodistribution studies showed localization of TES-23 into tumor tissues 60 min after intravenous injection. TES-23 suppressed significantly the growth of KMT-17 solid tumors following administration for 5 days. Histo-pathological examination showed that TES-23 caused degeneration, apoptosis and/or necrosis and denudation of endothelial cells in viable tumor areas following local aggregation and adhesion of lymphocytes, with subsequent intravascular thrombus formation by platelets and fibrin. Our results indicate that TES-23, which recognizes TEC, can target endothelial cells of solid tumor vasculature directly, resulting in growth suppression in vivo by reduction of blood flow due to intravascular thrombosis. Our results also suggest that targeting tumor vasculature is a potentially attractive approach for the treatment of solid tumors.

Animals↗
PubMed1999

Vascular endothelial growth factor VEGF-like heparin-binding protein from the venom of Vipera aspis aspis (Aspic viper).

The heparin-binding dimeric hypotensive factor (HF) was purified from Vipera aspis aspis (Aspic viper) venom [Komori, Y. and Sugihara, H. (1990) Toxicon 28, 359-369]. In this study, the amino acid sequence, and structure and function of HF, were elucidated. By electrospray ionization mass spectrometry (ESI-MS), the molecular weight of HF was determined to be 25 072.1. The complete amino acid sequence of HF was determined by Edman sequencing of the S-pyridylethylated HF and its peptides derived from enzymatic digestion. The theoretical molecular mass calculated from the primary structure agrees well with the molecular weight determined by ESI-MS. HF consists of two homogeneous monomers bound covalently. The monomer with an N-terminal blocked by pyroglutamic acid contains 110 amino acid residues, including eight cysteine residues, two of which are considered to be involved in intermolecular disulfide bonds. Sequential homology search revealed that the primary structure of HF is similar to that of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) with a sequential homology of 45 and 22%, respectively. When injected intradermally into a rat, an increase in capillary permeability was observed with HF or VEGF. On the other hand, only HF exerted a strong hypotensive effect after intravenous injection of samples into a rat. Purified HF has a mitogenic effect on endothelial cells. Through the use of bovine aortic endothelial cells (BAEC), the half-maximal mitogenic concentration of HF was determined to be 5-5. 5 nM (125-138 ng/mL). Similarly, VEGF had a mitogenic concentration at 0.5-1 nM. When incubated with HF and cycloheximide or HF and heparin, the cell growth was inhibited, suggesting that the mechanism of action of HF is similar to that of VEGF.

Amino Acid Sequence↗
PubMed1999

Sendai virus-based production of HIV type 1 subtype B and subtype E envelope glycoprotein 120 antigens and their use for highly sensitive detection of subtype-specific serum antibodies.

We previously described a Sendai virus (SeV)-based expression system for the recombinant gp120 of HIV-1 subtype B (rgp120-B), which has permitted the production of antigenetically and functionally authentic gp120 at a concentration as high as 6 microg/ml of culture supernatant (Yu D et al.: Genes Cells 1997;2:457-466). Here the same procedure was successfully applied to the production of HIV-1 subtype E gp120 (rgp120-E). The remarkable production of the proteins by the SeV expression system enabled us to use crude culture supernatants for serological and functional studies of gp120s. The immunological authenticity of rgp120-E was verified by patient sera and anti-V3 loop monoclonal antibodies specific for HIV-1 subtypes B and E. CD4-binding properties were corroborated by FACS analyses. The rgp120s were then used in an enzyme immunoassay (rgp120-EIA) to detect antibodies in the sera of HIV-1-infected individuals, and the performance was assessed in comparison with a conventional V3 loop peptide EIA (V3-EIA). The initial evaluation of a serum panel (n = 164) consisting of 76 subtype E and 88 subtype B sera revealed that the rgp120-EIA was nearly 1000-fold more sensitive than the V3-EIA and was able to detect subtype-specific antibody with 100% sensitivity and with a complete correlation with the genotypes, whereas the V3-EIA failed to detect 9 and 24% of the same subtype E and B sera, respectively. Furthermore, a study employing a panel of 28 international sera with known genotypes (HIV-1 subtypes A through F) confirmed the remarkable specificity of this method. An EIA reactivity higher than 1.0 was an unambiguous predictor of HIV-1 subtype E and B infections. The data imply the presence of strong subtype-specific epitopes for antibody bindings to these rgp120s.

Antibodies, Viral↗
PubMed1999

Characterization of olfactory receptor organs in Xenopus laevis Daudin.

Xenopus laevis is highly suitable for studying the mechanisms of olfactory reception for water-soluble odorants and for airborne odorants. However, the functional differences of cells and component protein molecules in the olfactory receptors of Xenopus have remained obscure. In recent studies, the patterns of sugar residues expressed on the cell surface have been utilized to analyze the characteristics of neurons, because the sugar chains in neurons play very important roles in targeting and cell-to-cell communication. In this study, we have determined the distribution of sugar residues and glycoproteins in the olfactory receptor organs of Xenopus using lectins as labeling agents, and characterized the receptors of water-soluble odorants and of airborne odorants. The results of lectin histochemical analysis show distributional differences of GlcNAc, GalNAc and mannose between the middle chamber and the lateral chamber of the main nasal cavity. Furthermore, a 65 kDa glycoprotein containing mannose, GlcNAc and GalNAc was specifically detected in the medial chamber of the main cavity epithelium in receptor organs of airborne odorants by SDS-PAGE and lectin blotting. The characteristics of the epithelia demonstrated in this study should further our understanding of the functional differences between the receptors of water-soluble odorants and of airborne odorants at the molecular level.

Acetylgalactosamine↗
PubMed1999

Tumor vascular targeting using a tumor-tissue endothelium-specific monoclonal antibody as an effective strategy for cancer chemotherapy.

In this study, we attempted to develop tumor vascular targeting with a tumor tissue endothelium-specific monoclonal antibody. TES-23, which strongly and selectively recognizes tumor tissue endothelial cells, was chemically conjugated with Neocarzinostatin (NCS), and the anti-tumor effect was examined. The immunoconjugate, TES-23-NCS, showed, through the use of tumor hemorrhagic necrosis, a marked anti-tumor effect on KMT-17 tumors in rats at a dosage of 17 micrograms/kg (NCS equivalent) without any side effects, probably due to specific tumor vascular injury. By contrast, TES-23 alone (107 micrograms/kg), NCS alone (17 micrograms/kg), and Mopc-NCS (Mopc, 107 micrograms/kg; NCS, 17 micrograms/kg), the immunoconjugate of control antibody, did not have any anti-tumor activities. By tissue distribution analysis, TES-23 and TES-23-NCS showed high accumulation in KMT-17 tumors 1 h after intravenous administration. Moreover TES-23 also accumulated in Sarcoma-180 tumors in mice 1 h after intravenous administration. These results suggest that TES-23 may be a candidate for a potential tumor vascular targeting agent that is applicable to a wide variety of tumor types.

Animals↗
PubMed1999

New brittle bone disorder: report of a family with six affected individuals.

We report on a family in which four females and two males in three generations had a previously undescribed brittle bone disorder that was dominantly transmitted through a maternal line. The cardinal manifestations of the disorder comprised dolichocephaly with frontal bossing, hypoplasia of the midface, postpubertal prognathism, micromelic short stature, coarse trabeculae of the entire skeleton, and bone fragility of variable degrees. Mild spondylar modification and iliac hypoplasia were other hallmarks that were recognized in childhood. The proband, a 19-year-old male, was most severely affected with multiple wormian bones in the calvaria, repetitive fractures, intractable bowing of the legs and forearms, and pseudofractures of the long bones with metaphyseal narrowing. His male cousin was next severely affected with angular deformity restricted to the forearm. The four females were much less affected without angular deformity. The mode of inheritance was thus consistent with either an autosomal dominant trait with sex-influence or an X-linked semidominant trait. Histological bone examination in the proband showed atrophy and fibrous degeneration of the lamellar trabeculae and disorganized chondro-osseous junction, which implied that the disorder involved both intramembranous and enchondral ossifications.

Adult↗
PubMed1999

Isolation and characterization of a mouse SRY-related cDNA, mSox7.

SOX is a family of SRY-related genes, which encode transcriptional factors involved in development. In this study, we newly isolated and sequenced mouse cDNA clones for mSox7. The mSox7 gene encodes 380 amino acids containing an SRY-type HMG box. Genomic Southern analysis suggested that the mSox7 gene was a single-copy gene. Tissue specific expression of mSox7 was investigated by Northern analysis. The expression was restricted to the ovary and heart, and the size of the transcripts was estimated to be 3.6 knt. Electrophoretic mobility shift assay indicated that recombinant mSox7 polypeptide was capable of binding to a nucleotide sequence, AACAAT. Immunohistochemical study revealed that mSox7 protein was localized in oocytes in the mouse ovary.

Amino Acid Sequence↗
PubMed1999

Enzymes of porcine brain hydrolyzing 2-arachidonoylglycerol, an endogenous ligand of cannabinoid receptors.

Anandamide and 2-arachidonoylglycerol (2-AG) are two endogenous ligands for the cannabinoid receptors, and their cannabimimetic activities are lost when they are hydrolyzed enzymatically. Cytosol and particulate fractions of porcine brain exhibited a high 2-AG hydrolyzing activity of 100 nmol/min/mg protein. Most of the activity could be attributed to a monoacylglycerol lipase-like enzyme that did not hydrolyze anandamide. It was separated by hydroxyapatite chromatography from anandamide amidohydrolase, which is also capable of hydrolyzing 2-AG as well as anandamide. Thus, porcine brain has at least two enzymes capable of hydrolyzing 2-AG. The 2-AG hydrolase activities of both the cytosolic and particulate enzymes were irreversibly and time-dependently inhibited by methyl arachidonyl fluorophosphonate with IC50 values as low as 2-3 nM.

Amidohydrolases↗
PubMed1999

Developmental stage-specific involvement of angiotensin in murine nephrogenesis.

Angiotensinogen-deleted mice (Agt-KO) show phenotypes of hypotension and renal atrophy. To investigate whether an alternative pathway other than angiotensin II (AII), i.e., processed angiotensin fragments, may play a biological role in nephrogenesis, we analyzed a congenic line of Agt-KO fetuses and neonates derived from two sources: one (Agt-KO/He) from mating with heterozygous angiotensinogen-deleted mice and the other (Agt-KO/Ho) from mating homozygous angiotensinogen-deleted mice. Although Agt-KO/He did not show a typical phenotype at birth, these mice showed papillary atrophy 2 weeks later and thereafter, a marked increase in renal size, i.e., pelvic dilatation. In contrast, Agt-KO/Ho showed renal abnormalities at birth and subsequently died. TUNEL staining and electron microscopy revealed that accelerated papillary apoptosis was present at birth in Agt-KO/Ho and caused abnormal papillary development; however, apoptosis was not detected in Agt-KO/He, suggesting that different mechanisms for the abnormal renal development exist in Agt-KO/He and Agt-KO/Ho. Two-week administration of an angiotensin fragment (3-8), angiotensin IV (AIV), to Agt-KO/He markedly attenuated the renal atrophy, decreasing the incidence from 81% to 14%. However, administration of AIV to fetal Agt-KO/Ho through the mother did not decrease the incidence. This is marked contrast to AII, which prevented renal atrophy in both fetal and neonatal periods. It is therefore suggested that AIV is involved in nephrogenesis in a developmental stage-specific manner.

Angiotensin II↗
PubMed1999

Analysis on reassortment of rotavirus NSP1 genes lacking coding region for cysteine-rich zinc finger motif.

Rotavirus clones A5-10 and A5-16 isolated from a bovine rotavirus strain A5 possess NSP1 gene which has a point mutation generating a nonsense codon and a 500 base-deletion, respectively. As a result, the two A5 clones encode truncated NSP1 product which lacks cysteine-rich region forming zinc finger motif. In order to analyze reassortment of these mutated NSP1 gene with RNA segments from heterologous strains, we investigated a number of reassortant clones derived from coinfection with either A5-10, A5-16 or a reference strain A5-13 (possessing intact NSP1 gene) and either simian rotavirus SA11 or human rotavirus KU. In coinfection with SA11 and A5-13, selection rates of A5-13 segments in reassortants ranged approximately from 20 to 70% (46% for NSP1 gene). In contrast, in the reassortment between SA11 and A5-10 or between SA11 and A5-16, selection rates of NSP1 gene from A5-10 and A5-16 were only 1% (one clone) and 0%, respectively. In reassortants from crosses KU x A5-clones, selection rate of A5-13 NSP1 gene decreased to 15%, while 11 reassortants with A5-10 NSP1 gene (31%) and one reassortant with A5-16 NSP1 gene (2%) were isolated. Reassortants with A5-10 NSP1 possessed a single gene (segment 9 or 11) from KU in the genetic background of A5-10. One reassortant clone (cl-55) with A5-16 NSP1 gene possessed KU gene segments 3, 4, and 8-11. When single-step growth curves were compared, the reassortant cl-55 showed almost identical growth curve to that of KU, while KU showed a better replication than A5-16. These results indicated that although A5-10 or A5-16 NSP1 gene encoding the truncated NSP1 is selected into reassortants much less efficiently than normal NSP1 gene, the reassortants with the mutated NSP1 gene and RNA segments from heterologous strains normally replicated in cultured cells. Thus, cysteine-rich region of NSP1 was not considered essential for genome segment reassortment with heterologous virus.

Animals↗
PubMed1999

Functional analysis of the heterologous NSP1 genes in the genetic background of simian rotavirus SA11.

Function of rotavirus NSP1 was analyzed by using single-NSP1 gene-substitution reassortants, SKF, SDF, and SNF which have the NSP1 gene derived from human rotaviruses KU, DS-1, and canine rotavirus K9, respectively, in the genetic background of simian rotavirus SA11. The NSP1 genes from KU, DS-1, K9, and SA11 exhibited 58-76% nucleotide sequence identity to one another. No substantial difference in viral growth was observed among the reassortants and SA11. However, production of NSP1 was not detected in SNF when viral proteins were labelled with 35S-methionine during replication in MA104 cells, in contrast to SA11, SKF and SDF which exhibited evident expression of NSP1. Difference in reassortant formation was examined among the reassortant clones generated between human rotavirus strain 69M and either of SA11, SKF or SNF. Although reassortant formation rate was significantly lower in the cross 69M x SNF than the other crosses, selection rates of RNA segments from parent strain 69M in the resultant reassortants was similar among the crosses. Selectivity of homologous and heterologous NSP1 genes in SA11 background was also analyzed by mixed infection and multiple passages among the single-NSP1 gene-reassortants and/or SA11, KU NSP1 gene was selected most frequently, whereas homologous (SA11) NSP1 gene was least efficiently segregated. These results indicated that viral growth and genome segment reassortment with other viruses may not be influenced by the presence of heterologous NSP1 and its expression level, while genomic diversity of NSP1 genes might have been associated with the relative adaptability to the genetic background of SA11.

Animals↗
PubMed1999

Intraoperative lavage for cytological examination in 1,297 patients with gastric carcinoma.

BACKGROUND: This study examined the clinical value of intraoperative peritoneal lavage for cytological examination in patients with gastric cancer. Peritoneal dissemination is the most frequent mode of recurrence for this tumor. METHODS: A retrospective of lavage findings, other factors, and outcome was performed in 1,297 patients with gastric cancer who underwent intraoperative peritoneal lavage. RESULTS: The 5-year survival rate of patients with positive lavage cytology was only 2%. Patients who underwent curative resection and had negative cytology had a significantly better 5-year survival rate (P < 0.001). Even among patients with macroscopic peritoneal dissemination, the survival rate was significantly better with negative cytology, which reflected fewer free cancer cells in the peritoneal cavity. Serum concentrations of carcinoembryonic antigen and carbohydrate antigen 19-9 were significantly higher in patients with positive cytology. Multivariate analyses indicated that intraoperative cytological findings was an independent prognostic factor for survival, and was the most important factor for predicting peritoneal recurrence. CONCLUSIONS: Intraoperative peritoneal lavage cytology is important in predicting survival and peritoneal recurrence in gastric cancer.

Biomarkers, Tumor↗
PubMed1999

Association of smooth muscle cell phenotypic modulation with extracellular matrix alterations during neointima formation in rabbit vein grafts.

PURPOSE: To clarify the mechanisms of structural changes underlying vein graft stenosis that limits efficacy of bypass grafting operation, we examined the accumulation and distribution of various extracellular matrix (ECM) components during neointima formation in rabbit vein grafts and analyzed their correlation with proliferation and phenotypic modulation of smooth muscle cells (SMCs). METHODS AND RESULTS: An autologous external jugular vein graft was transplanted into the carotid artery in 25 rabbits. After the restoration of blood flow, the graft was markedly dilated. Medial SMCs in the graft appeared to be injured, and they began to proliferate at day 4 and subsequently migrated and formed the neointima at day 7. The neointima observed at days 7 and 14 contained ECM components, including type I collagen, heparan sulfate, and chondroitin sulfate, and the intimal SMCs were phenotypically modulated from the differentiated-type (SM2-positive and SM embryonic-negative) to the dedifferentiated-type (SM2-negative and SM embryonic-positive) as determined with immunostainings for myosin heavy chain isoforms. The intimal SMC proliferation was maximal at 2 weeks and then decreased rapidly. However, the neointima continued to thicken thereafter throughout the 6-month period of the experiment, and ECM accumulation, such as type I collagen and decorin, a small dermatan sulfate proteoglycan, was a prominent feature observed in the hypocellular region of the deep intima from 2 months after the transplantation. The phenotype of the intimal SMCs gradually returned to the differentiated-type from the deep intima after 2 months, but a small number of the intimal SMCs remained in the dedifferentiated phenotype even at 6 months after the operation. CONCLUSION: The neointima in the vein graft was formed initially by means of migration and proliferation of the phenotypically modulated, dedifferentiated-type SMCs and continued to thicken by means of sustained ECM accumulation, including type I collagen and decorin, in association with the prolonged presence of the dedifferentiated-type SMCs. These chronologic features in cell kinetics and ECM accumulation may contribute to the frequent occurrence of graft wall thickening that occurs in the vein grafts.

Animals↗
PubMed1999

Electronic network for monitoring travellers' diarrhoea and detection of an outbreak caused by Salmonella enteritidis among overseas travellers.

The Traveller's Diarrhoea Network, by which the Infectious Disease Surveillance Center is electronically connected with two major airport quarantine stations and three infectious disease hospitals, was launched in February 1988 in Japan. The data on travellers' diarrhoea detected is reported weekly by e-mail. Two clusters of infection among travellers returning from Italy were reported by two airport quarantine stations at the end of September 1998. A total of 12 salmonella isolates from 2 clusters were examined. All were identified as Salmonella enteritidis, phage type 4 and showed identical banding patterns on pulsed-field gel electrophoresis. A case-control study showed that the scrambled eggs served at the hotel restaurant in Rome were the likely source of this outbreak. This outbreak could not have been detected promptly and investigated easily without the e-mail network. International exchange of data on travellers' diarrhoea is important for preventing and controlling food-borne illnesses infected abroad.

Adult↗