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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 667 records · Page 37Linked to original sources
PubMed1993

Antithrombotic effect of recombinant human soluble thrombomodulin on endotoxin-induced disseminated intravascular coagulation in rats.

Thrombomodulin (TM) is an endothelial cell membrane glycoprotein which neutralizes thrombin procoagulant activity and accelerates the thrombin-catalyzed activation of protein C. We expressed recombinant human soluble TM (rhs-TM) in Chinese hamster ovary cells and compared the effects of rhs-TM and heparin on endotoxin-induced experimental disseminated intravascular coagulation (DIC) in rats. Experimental DIC was induced by a continuous intravenous infusion of endotoxin for four hours. rhs-TM or heparin was infused simultaneously with endotoxin. Treatment with rhs-TM significantly reversed the endotoxin-induced changes in significantly reversed the endotoxin-induced changes in following parameters: platelet count, fibrinogen level and fibrinogen and fibrin degradation products. Furthermore, glomerular fibrin deposits elevated by endotoxin treatment were reduced by the rhs-TM administration. Heparin showed the similar effects to rhs-TM. Activated partial thromboplastin time (APTT) in rats receiving rhs-TM were slightly longer than APTT in endotoxin-treated rats, but rats receiving heparin had much more prolonged APTT. From these results, we concluded that rhs-TM may be useful for the clinical treatment of DIC while having only minor adverse effects on APTT.

Animals↗
PubMed1993

Structure of Boc-Phe-D-Leu-Thr-OMe.

The X-ray crystal structure analysis shows that tert-butoxycarbonyl-L-phenylalanyl-D-leucine-L-threonine methyl ester takes an open conformation in which the tert-butoxycarbonyl group is located face-to-face with the D-leucine isobutyl side chain. In the crystal, the molecules, translated by twofold screw symmetry, form an infinite sheet structure through four independent hydrogen bonds.

Amino Acid Sequence↗
PubMed1993

Lack of association between bipolar affective disorder and tyrosine hydroxylase DNA marker.

Sixty-eight patients with bipolar affective disorder and 88 controls were investigated for genetic association of tyrosine hydroxylase (TH) restriction fragment length polymorphisms (RFLPs). No significant association between bipolar affective disorder and TH was found. Thus the hypothesis that TH is involved in the pathogenesis of bipolar affective disorder was not supported.

Adult↗
PubMed1993

Interaction of mutagenic tryptophan pyrolysate with DNA. CD spectral study on the binding specificity.

The interactions of DNA duplexes with 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), a potent mutacarcinogen isolated from tryptophan pyrolysate, have been studied using CD spectroscopy. The results are that (a) the spectral change of B-form DNA caused by the interaction with Trp-P-1 is biphasic, i.e. the enlargement of CD bands characteristic to the B-DNA conformation in the range of r ([Trp-P-1]/ DNA]) = 0-2.5, followed by the rapid transition to the non-B conformation at r > 2.5; (b) this transition degree of B to non-B conformation of DNA is not necessarily dependent on the G-C content; and (c) the salt-induced Z-DNA is transformed to B-DNA (0 < r < 0.1) and then to non-B-DNA (r > 5), depending on the concentration of Trp-P-1 added. These data indicate that the non-covalent interaction of Trp-P-1 with DNA is mainly dependent on the B-DNA conformation.

Base Sequence↗
PubMed1993

[Staging of rectal cancer: assessment with Gd-DTPA enhanced MR imaging].

This study was designed to assess the value of Gd-DTPA enhanced imaging in the staging of rectal carcinoma. Twenty-five patients were prospectively evaluated with MR imaging using a 1.5 Tesla unit. Based on the results of a barium study and/or digital examination, a balloon catheter was inserted to the level of the lesion before examination. Both T1- and T2-weighted images and Gd-DTPA enhanced images were obtained in all patients, and Gd-DTPA enhanced fat-saturation images were obtained in 11 patients. When both T1- and T2-weighted images were used, 24% of tumors were ill defined. However, when Gd-DTPA and Gd-DTPA enhanced fat-saturation imaging was added, all tumors were well defined and the quality of the images increased. There was no significant difference between images in the detection of muscular invasion. In the detection of perirectal fat invasion, however Gd-DTPA fat-saturation imaging showed increased sensitivity. Nevertheless, it also decreased specificity, so there was no significant difference between images. In the detection of metastatic lymph nodes, Gd-DTPA enhanced and Gd-DTPA enhanced fat-saturation imaging were not useful. Tumor detection using Gd-DTPA enhanced fat-saturation images was excellent. However, the accuracy of staging was not improved by supplemental Gd-DTPA enhancement.

Adult↗
PubMed1993

[Transthoracic percutaneous ethanol injection for the liver].

Fourteen normal rats were received with percutaneous ethanol injection (PEI) in the subphrenic region of the liver, using a 22G fine needle, via the thoracic cage. The procedure was successful in all rats. Minor complications were observed in 3 rats: these included pneumothorax, hemorrhage, and pleural effusion. However all complications had disappeared in the follow up CT one week after the procedure. The transthoracic approach is a useful and safe method of PEI for the subphrenic region of the liver.

Animals↗
PubMed1993

Molecular cloning and characterization of the promoter region of the human c-erbA alpha gene.

The c-erbA alpha gene encodes the alpha type thyroid hormone receptor. This gene is expressed in various types of cells, its expression being relatively high in the central nervous system. A genomic clone that contains the 5'-terminal portion of the human c-erbA alpha gene was isolated. The 615 base pair (bp) 5'-flanking sequence of the c-erbA alpha gene showed promoter activity when placed upstream of the bacterial chloramphenicol acetyltransferase gene and transfected into HeLa cells. Nine transcriptional initiation sites were detected within this sequence by S1 nuclease protection analysis. DNA sequence analysis showed that the promoter region contains ten putative binding sites for transcriptional factor Sp1 in the GC rich region (86%). Three putative cAMP responsive elements (CRE) and one putative TPA responsive element (TRE) were identified upstream of the GC rich region. The c-erbA alpha promoter sequence also contains a putative binding site for the Krox-20 transcriptional factor, which is thought to play a role in early development of the mouse central nervous system.

Base Sequence↗
PubMed1993

Conformation of deltorphin-II in membrane environment studied by two-dimensional NMR spectroscopy and molecular dynamics calculations.

Two-dimensional homonuclear Hartmann-Hahn spectroscopy and NOESY (nuclear Overhauser effect and exchange spectroscopy) 1H-NMR techniques have been used to obtain complete proton resonance assignments and to perform a conformational investigation of deltorphin-II (Tyr-D-Ala-Phe-Glu-Val-Val-Gly-NH2), a naturally occurring delta-selective opioid peptide, in the membrane-mimetic micelles of perdeuterated dodecylphosphocholine. This was done in order to examine conformational characteristics that would be closely related to the selectivity towards the delta-opioid receptor. With the use of the proton-proton distances derived from NOESY measurements, 50 possible three-dimensional structures were generated by means of distance-geometry calculations, and 25 of them were subjected to the molecular-dynamics simulations of 10 ps, which were energetically constrained for the NOE interproton distances. Most of the possible conformers simulated showed a common feature such that the conformation of deltorphin-II is characterized by the S-shaped back-bone structure in which the turn conformation of the Val-Val-Gly-NH2 sequence is located under the helically folded conformation of the N-terminal Tyr-D-Ala-Phe-Glu sequence. The possible relationship between this conformational characteristic and the delta-opioid-receptor selectivity has been discussed.

Amino Acid Sequence↗
PubMed1993

Purification of 3,5-dichlorocatechol 1,2-dioxygenase, a nonheme iron dioxygenase and a key enzyme in the biodegradation of a herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), from Pseudomonas cepacia CSV90.

An enzyme which cleaves the benzene ring of 3,5-dichlorocatechol has been purified to homogeneity from Pseudomonas cepacia CSV90, grown with 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole carbon source. The enzyme was a nonheme ferric dioxygenase and catalyzed the intradiol cleavage of all the examined catechol derivatives, 3,5-dichlorocatechol having the highest specificity constant of 7.3 microM-1s-1 in an air-saturated buffer. No extradiol-cleaving activity was observed. Thus, the enzyme was designated as 3,5-dichlorocatechol 1,2-dioxygenase. The molecular weight of the native enzyme was ascertained to be 56,000 by light scattering method, while the M(r) value of the enzyme denatured with 6 M guanidine-HCl or sodium dodecyl sulfate was 29,000 or 31,600, respectively, suggesting that the enzyme was a homodimer. The iron content was estimated to be 0.89 mol per mole of enzyme. The enzyme was deep red and exhibited a broad absorption spectrum with a maximum at around 425 nm, which was bleached by sodium dithionite, and shifted to 515 nm upon anaerobic 3,5-dichlorocatechol binding. The catalytic constant and the Km values for 3,5-dichlorocatechol and oxygen were 34.7 s-1 and 4.4 and 652 microM, respectively, at pH 8 and 25 degrees C. Some heavy metal ions, chelating agents and sulfhydryl reagents inhibited the activity. The NH2-terminal sequence was determined up to 44 amino acid residues and compared with those of the other catechol dioxygenases previously reported.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1993

[An experimental study of a new embolic material--Lipiodol suspension of water-absorbent particle].

A water-absorbent particle (a polymer of polyacrylic acid soda) was investigated as a new embolic material. The size of a single particle is 200 microns (N-100) or 10 microns (NP-1010). A particle absorbs 100 times its own weight of physiologic NaCl solution within a few seconds. The particles have no acute or chronic toxicity or immunogenicity. This material suspended by Lipiodol was evaluated in an in vitro study using an AVM model composed of a plastic syringe and polyurethane sponge. The AVM model was perfused by physiological NaCl solution at a pressure of 150 mmHg. The swollen polymer worked as an adequate embolic material in the AVM model, using a minimum quantity. The embolic effect depended upon the quantity and concentration of the suspension. Restoration of flow was not observed within a period of ten minutes. The embolized part was clearly visualized due to the retention of Lipiodol. This material is a promising agent for arterial embolization.

Absorption↗
PubMed1993

Induction of apoptosis by hemorrhagic snake venom in vascular endothelial cells.

Vascular degeneration appears to play crucial roles in producing many vascular malfunctions (1-3). In order to identify specific inducers of programmed death in vascular endothelial cells (VEC), examinations were made of the effects of substances that are known to affect the vascular system by using VEC in culture (4,5). We found that hemorrhagic snake venoms induced apoptotic cell death or programmed cell death of VEC. By contrast, neurotoxic snake venoms did not induce programmed cell death but caused necrosis at much higher doses of the venoms. No effect of hemorrhagic venom was observed with many types of cultured cells other than VEC. Thus, hemorrhagic snake venom appears to be a useful tool for studies of the molecular mechanisms of vascular apoptosis. The results also suggest a possible mechanism of action of hemorrhagic snake venom on the vascular system.

Animals↗
PubMed1993

Triphasic vascular effects of thiol compounds and their oxidized forms on dog coronary arteries.

The vascular effects of 2-mercaptoethanol, cysteamine, L-cysteine, glutathione (GSH), cystamine and oxidized GSH (GSSG) on the isometric tension of isolated dog coronary arterial strips were examined, and these effects were compared with the triphasic response induced by dithiothreitol (DTT); a rapid and weak contraction (phase A), an intervening slow relaxation (phase B) and a slowly-developing strong contraction (phase C) which we previously reported. The responses of the arteries induced by 2-mercaptoethanol, cysteamine and L-cysteine consisted of phases A, B and C. The order of contractile potency (ED50 of phase C) was DTT approximately L-cysteine > 2-mercaptoethanol approximately cysteamine, while the order of relaxant potency (ED50 of phase B) was DTT > cysteamine approximately 2-mercaptoethanol. GSSG and cystamine mainly produced relaxation, which corresponded to phase B. The phase C contraction was specific to the reduced forms of thiols, except for GSH, which produced only relaxation. The participation of endothelial cells was not essential for the contracting or relaxing effects of the thiol compounds. The phase C contraction was depressed by W-7, a calmodulin antagonist, while phase A was not. Therefore calmodulin-dependent protein kinases may participate in phase C, not in phase A.

Animals↗
PubMed1993

Conformational difference between diastereomers of Dnp-Val-Aib-Gly-Leu-pNA studied by x-ray crystal analyses.

In order to investigate the conformational change of the alpha-aminoisobutyric acid (Aib) containing peptide by the D/L replacement of an amino acid residue, single crystals of two diastereomers, Dnp-L-Val-Aib-Gly-L-Leu-pNA (L-L isomer) and Dnp-D-Val-Aib-Gly-L-Leu-pNA (D-L isomer), were prepared from aqueous methanol solutions as CH3OH and CH3OH.H2O solvates, respectively, and were analyzed by the x-ray diffraction method. Molecular conformation of L-L isomer adopts consecutive two different types of beta-turns, a type II' beta-turn bent at Aib-Gly, and a type III beta-turn bent at Gly-Leu, stabilized by two intramolecular (Leu)NH...O = C(Val) and (pNA)NH...O = C(Aib) hydrogen bonds. In contrast, these two intramolecular hydrogen bonds lead the D-L isomer to a distorted 3(10)-helix conformation consisting of consecutive two type-III beta-turn of Aib-Gly-Leu sequence. The most significant structural difference between these diastereomers is the mutual orientation between the Dnp and pNA chromophores. While the extensive stacking of both the chromophores is intramolecularly formed for the folded conformation of L-L isomer, they are oriented toward an opposite direction in the open conformation of D-L isomer and are intermolecularly stacked with each other. The large separation between these diastereomers observed in the chromatography is discussed in the relation with their conformational differences.

Amino Acid Sequence↗
PubMed1993

Monoclonal antibody KP16D3 as a prognostic marker in stage I lung adenocarcinoma.

Monoclonal antibody KP16D3 recognizes a 60 kDa protein associated with mucin-nonproducing papillary adenocarcinoma, especially that originating from nonciliated bronchiolar epithelial cells of the lung. We immunohistochemically examined 56 primary lung adenocarcinomas using the monoclonal antibody KP16D3. Of these tumors, 31 (55%) were positive for KP16D3 immunoreactivity. The disease-free survival rates showed no statistical differences between KP16D3-positive and KP16D3-negative patients. However, in stage I and T1 disease, the disease-free survival rates of KP16D3-positive patients were statistically lower than those of KP16D3-negative patients (P < 0.05). These findings suggest that KP16D3 may be useful as a prognostic marker for patients with stage I primary lung adenocarcinoma. Conversely, use of this marker and subtyping of lung adenocarcinomas reflect the prognosis of the disease.

Adenocarcinoma↗
PubMed1993

Calcium pump expression in human bone and soft tissue tumours.

Ninety-one cases of human bone and soft tissue tumours were studied for calcium pump expression by strepto-avidin-biotin immunohistochemical staining with a monoclonal antibody against sarcoplasmic reticulum calcium-ATPase (mAb6F5). Two out of 5 cases of embryonal rhabdomyosarcoma, 1 out of 5 cases of biphasic synovial sarcoma, 4 of 4 cases of chordoma and all of 3 chondrosarcoma cases were positive for mAb6F5. Although this novel monoclonal antibody can be used as a marker of myogenic tumours, the present positive result for endoplasmic reticulum calcium-ATPase (calcium pump) in other tumours including chordoma, chondrosarcoma and synovial sarcoma indicates a wider immunoreactivity. The findings further suggest that intracellular calcium may play an important role in cell proliferation and/or differentiation.

Adult↗
PubMed1993

Parachordoma: an ultrastructural and immunohistochemical study.

A case of parachordoma of the left calf in a 19-year-old Chinese female is reported. The tumour showed multinodular growth pattern and consisted of round or oval tumour cells with abundant eosinophilic cytoplasm and myxoid matrix. Tumour cells formed small nests and sometimes showed concentric arrangement. Physaliferous-like cells and undifferentiated spindle cells were occasionally observed among the cell nests. The myxoid matrix was positive for high-iron diamine stain, indicating the presence of chondroitin 4- and 6-sulphates and keratan sulphate. Ultrastructurally, well-developed rough endoplasmic reticulum, abundant intermediate filaments, microvillous cytoplasmic processes, pinocytic vesicles, and desmosome-like junctional structures were found. Tumour cells were positive for S-100 protein and vimentin, but negative for cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and desmin. These results are consistent with the definition of parachordoma as a soft tissue neoplasm consisting of cells with histology and ultrastructure similar to those of chordoma cells but with immunohistochemistry similar to that of chondroid tumour cells.

Adult↗
PubMed1993

Effect of postoperative intrapleural instillations of interleukin-2 in patients with malignant pleurisy due to lung cancer.

Thirteen patients with resectable lung cancer and concomitant malignant pleurisy which could not be detected by preoperative chest roentgenograms were treated with surgical resection of the primary lesions and postoperative intrapleural instillations of interleukin-2 (IL-2). All of the patients demonstrated disappearance of cancer cells from pleural effusion after the IL-2 therapy. Four of the 13 patients survived over 5 years and 2 of them are in disease free state at this moment (January 31, 1993). The first recurrent sites were distant organs in 8 of 11 patients with recurrence and lymph nodes in 3 of them. No pleural recurrence was observed. These results indicate that the postoperative intrapleural IL-2 therapy may be one of hopeful adjuvant therapies in patients with resectable lung cancer and concomitant malignant pleurisy, although distant metastasis and lymph node recurrence could not be suppressed completely.

Adenocarcinoma↗