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T Kumazaki

Publications and source records attributed to T Kumazaki.

At least 163 records · Page 9Linked to original sources
PubMed1993

[Transcatheter hepatic arterial embolization for the treatment of blunt hepatic injury].

To examine the indications of transcatheter arterial embolization (TAE) for blunt hepatic injury, angiographic images, CT images and medical records were reviewed. Hepatic angiography was performed in 30 patients with blunt hepatic injury. Sixteen of them who underwent TAE therapy immediately after angiography formed the TAE(+)group, while the 14 patients who were not followed by TAE formed the TAE(-)group. Angiographic extravasation of the contrast medium was confirmed in 14 of 16 patients in the TAE(+)group. On CT scan, the most common finding in the TAE(+)group was a deep hepatic laceration, which was classified as type III according to the criteria of the Japanese association for the surgery of trauma. Hemoperitoneum and fresh hematoma were visualized in most of the TAE(+)group. The preoperative hemodynamics of the TAE(+)group were markedly unstable, but were significantly improved after TAE therapy. No major complications were encountered during or after TAE. These results suggested that TAE was an effective therapeutic procedure for the control of blunt hepatic injury in patients associated with unstable hemodynamics, deep hepatic laceration shown by CT scan and extravasation confirmed by angiography.

Adolescent↗
PubMed1993

Endothelin-1 is produced and secreted by neonatal rat cardiac myocytes in vitro.

Production of endothelin-1 in the cultured neonatal rat cardiac myocytes was investigated. Studies on the cultured cardiac myocytes with reverse transcription-polymerase chain reaction followed by Southern hybridization indicated that mRNA of ET-1(preproET-1 mRNA) was expressed by cardiac myocytes. ET-1 polypeptide was also detected in the cultured cardiac myocytes. Moreover, ET-1 was secreted into the culture medium by them. These results suggest that the cardiac myocytes, which have been regarded as target cells of ET-1, are able to synthesize and secrete ET-1. Furthermore, there may be a possible autocrine mechanism of ET-1 in the myocytes of a heart.

Animals↗
PubMed1993

[Efficacy of ultrasound detection of the oro- and hypopharyngeal carcinoma].

Sixteen histologically confirmed carcinomas of oro- and hypopharynx were examined by ultrasonography (US) from submental, submandibular, sub-auricular, and laterally cervical skin surface. Well-circumscribed hypoechoic tumors were demonstrated in twelve cases (75%). Nine of them had partial hypoechoic areas, such as "bull's eye pattern" or "pseudokidney sign". The remainder were one homogeneous hypoechoic mass and two inhomogeneous bulky tumors. In four negative studies, two were suspected too thin to be detected by US, and the other two could not be visualized by percutaneous scan because of their anatomical sites. The dimensions of demonstrated twelve tumors were measured three-dimensionally. The US information should be valuable for a prediction or an evaluation of the radiotherapy efficacy.

Adenocarcinoma↗
PubMed1993

Identification of the fatty acid binding site on glutathione S-transferase P by immobilization to fatty acid-linked sepharose.

The association of glutathione S-transferase P (GST-P) with various fatty acids was confirmed by gas-liquid chromatography and mass-spectrometry. Palmitic and stearic acids were the major fatty acids bound to the enzyme in which the molar ratio was 1:0.8 (GST-P:fatty acid). To evaluate the association with respect to the fatty acid carbon chain length and identify the binding site, we prepared a series of fatty acid-linked Sepharoses. GST-P tightly bound the fatty acid-linked Sepharoses (CH3(CH2)nCOOH, n = 4 approximately 16), and the site was determined to be residues 121-156 from the amino terminus by tryptic digestion of GST-P bound to a fatty acid-linked Sepharose. By fatty acid affinity labeling, we identified the binding site as residues 141-188 (Biochem. Biophys. Res. Commun., in press). The overlapping hydrophobic residues (residue 141-156) is expected to be essential for the ligand binding site.

Amino Acid Sequence↗
PubMed1993

A purification method and N-glycosylation sites of a 36-cysteine-containing, putative cell/cell adhesion glycoprotein gp64 of the cellular slime mold, Polysphondylium pallidum.

A 64-kDa membrane-bound glycoprotein (gp64) of the cellular slime mold Polysphondylium pallidum, is a putative cell/cell adhesion protein identified by adhesion-blocking antibody fragments (Fab). gp64 is expressed on the cell surface of growth-phase cells and seems to mediate cell/cell adhesion. This paper describes an improved purification method based on the lipophilic nature of this protein. A critical step in the purification method is to collect an insoluble top layer appearing during ammonium sulfate precipitation. The sequence of cDNA encoding gp64 and its deduced amino acid sequence have been determined previously. Based on cDNA sequence data, the structure of gp64 protein was analyzed: almost all amino acid compositions and partial amino acid sequences of lysylendopeptidase-digested peptides of gp64 were determined by protein analysis; all six asparagine-linked glycosylation sites (Asn-Xaa-Ser/Thr) in fact contain carbohydrates, and all 36 cysteine residues were involved in forming disulfide bridges. From these data, gp64 seems to be a unique protein among cell/cell adhesion proteins.

Amino Acid Sequence↗
PubMed1993

Enhanced expression of fibronectin during in vivo cellular aging of human vascular endothelial cells and skin fibroblasts.

Vascular endothelial cells are thought to play an important role in human aging as their senescence and/or detachment from vascular wall contribute to arteriosclerosis and high blood pressure in elderly persons. Since fibronectin is necessary for cell attachment and spreading and its increased expression has been reported in aging fibroblasts, we checked its expression in aortic endothelial cells aged in vivo. We found that the steady-state level of fibronectin expression increases with increasing donor age, while the labeling index of cultured cells decreases with age. The increased level of fibronectin expression correlated well with an increase in cell area. To explore whether these changes were a reflection of exhaustion of proliferation potential in vivo, we examined fibronectin expression in human umbilical vein endothelial cells aging in vitro. Very similar results were obtained, supporting the idea that vascular endothelial cells age in vivo by using up division potential. When we examined the expression of fibronectin in human skin fibroblasts aged in vivo and fetal lung fibroblasts aged in vitro, we obtained similar results. In conclusion, the level of expression of fibronectin and cell size increase during in vivo and in vitro aging of both endothelial cells and fibroblasts in a coordinate manner.

Aged↗
PubMed1993

Interaction of Streptomyces subtilisin inhibitor (SSI) with Streptomyces griseus metallo-endopeptidase II (SGMP II).

We have unexpectedly found that Streptomyces subtilisin inhibitor (SSI) and some other similar serine protease inhibitors produced by Streptomycetes strongly inhibit Streptomyces griseus metallo-endopeptidase II (SGMP II) [Kajiwara, K. et al. (1991) J. Biochem. 110, 350-354]. In order to elucidate the mode of their unusual interaction with SGMP II in more detail, we prepared twelve kinds of SSI analogues, in which one or two amino acid residues in the peptide segment from Thr64 to Val74 of wild-type SSI had been replaced or deleted by site-directed mutagenesis, and determined the dissociation constants of their complexes with SGMP II. Six analogues among them showed dissociation constants one order of magnitude lower than that of the wild type. Three had higher values. The results suggest that at least some residues in this segment are interacting with SGMP II in the complex. We also prepared an SSI mutant in which the disulfide bridge between Cys71 and Cys101 had been eliminated by replacing the two Cys residues with Ser residues. This mutated SSI inhibited SGMP II as strongly as the wild-type SSI did. While peptide bonds in the wild-type molecule did not suffer from the hydrolytic action of SGMP II except those at the amino-terminal fragile portion, the Pro72-Met73 bond of the mutant was specifically cleaved by the enzyme. This peptide bond, therefore, seems to play the role of the reactive site in the interaction of SSI with SGMP II.

Amino Acid Sequence↗
PubMed1993

Unusual inferior vena cava obstruction causing extensive thrombosis: an intravascular endoscopic observation.

A 28-year-old, previously healthy man was referred to our hospital three months after the appearance of lumbago, leg pains and fever. Routine examinations were normal. Phlebography demonstrated occlusion of the common femoral veins by thrombosis. Inferior vena cavography and magnetic resonance image showed that the inferior vena cava (IVC) became gradually narrower from the level of 11th thoracic vertebra. An intravascular endoscopic study gave the same morphological findings; the endothelial surface was found to be intact. We concluded that the stenosis of the IVC was the primary lesion and was the essential pathological condition. The massive thrombosis appeared to have occurred secondarily.

Adult↗
PubMed1993

Modulation of gene expression during aging of human vascular endothelial cells.

Vascular endothelial cells are thought to play an important role in human aging as their senescence and detachment from a vascular wall may contribute to arteriosclerosis and high blood pressure in the elderly. We investigated the level of fibronectin (FN) expression in aortic endothelial cells aged in vivo, because FN is necessary for cell attachment and spreading and its increased expression had been shown in aging fibroblasts. The results showed that the steady state level of expression of FN mRNA increased with advancing donor age, while the labeling index of cultured cells decreased with age. Furthermore, the increased level of FN expression clearly correlated with an increase in cell area. In order to explore whether these changes reflected exhaustion of proliferation potential in vivo, we examined FN expression in human umbilical vein endothelial (HUVE) cells aging in vitro. Very similar results were obtained, supporting the idea that vascular endothelial cells age in vivo by using up division potential. Furthermore, we investigated the level of endothelin (ET) -1 mRNA expression during in vitro cellular aging of HUVE cells. The results showed that the expression of ET-1 gene was also up-regulated when the culture became old. It is very interesting that the genes for quite different proteins of FN and ET-1 are both up-regulated during cellular aging.

Aged↗
PubMed1993

[RI venography for retroperitoneal hematoma following anticoagulant therapy for IVC filter thrombosis].

We presented a case of massive retroperitoneal hematoma owing to anticoagulant therapy for IVC filter thrombosis. CT showed the hematoma as high density area. RI venography demonstrated the thrombosis and collateral veins, suggesting the sites of anticoagulant induced bleeding and resultant hematoma. We suppose that RI venography is useful for the follow-up study of the IVC filter inserted cases.

Aged↗
PubMed1993

[Assessment of myocardial perfusion and left ventricular function with 99mTc-PPN 1011].

First-pass radionuclide angiography (FPRNA) was performed with the new myocardial perfusion agent 99mTc-1,2,bis[bis(2-ethoxyethyl)phosphino] ethane (99mTc-PPN 1011) on stress and at rest. One hour after that, myocardial perfusion was counted by 99mTc-PPN 1011 SPECT. Left ventricular ejection fraction (LVEF) obtained by FPRNA correlated with that by multigated image with 99mTc-HSAD (r = 0.94, n = 11). The reduction of left ventricular function under the exercise (delta LVEF) and the increase of severity score (delta Severity score) have a good relation (r = 0.88) in 7 patients with prior myocardial infarction. Thus 99mTc-PPN 1011 appears to be an ideal radiopharmaceutical for evaluation of ventricular function and myocardial perfusion.

Aged↗
PubMed1993

[Semi-quantitative evaluation of cerebral blood flow with modified bull's eye display using 123I-IMP SPECT].

We developed Modified Bull's Eye (MBE) display to demonstrate 123I-IMP SPECT images on a single map. To compare the difference of some SPECT images, we changed the ratio of the occipitofrontal diameter to the temporal diameter of oblique SPECT images and transformed the oblique images to round-shaped images. After circumferential profile analysis (CPA) was performed on the round-shaped oblique images, the data were mapped into a polar representation (MBE display). The severity score, as the index of severity of the perfusion defect, was calculated in the same way as the myocardial SPECT. We selected five slices from the round-shaped SPECT images and divided each slice into 12 areas. The severity of the perfusion defect was scored (0-3 points) visually, and the total score was defined as the "severity points". We compared the severity score with the severity points for 29 patients and six normal male volunteers. The correlation coefficient of the severity score and the severity points was 0.86 (p < 0.001). The MBE display makes it easy to evaluate SPECT images because it is represented on a single map, and it takes no more time to construct than the myocardial bull's eye display. It should be useful display.

Adult↗
PubMed1993

Effect of low-osmolality contrast media on red cell filterability.

The effects of low-osmolality contrast media (CM) on red blood cell (RBC) filterability were investigated using a recently developed nickel mesh filtration method. The conventional hypertonic CM iothalamate, low-osmolality iohexol, and the recently synthesized iomeprol were studied. Among them, the osmolality of iomeprol was the lowest. The impact of CM osmolality, viscosity, and iodine content on the RBC filterability was analyzed. Under equal iodine content or viscosity condition, the filterability order of RBCs suspended in CM was iomeprol > iohexol >> iothalamate, because of the osmolality of CM. Iomeprol caused small echinocytic changes but these had a negligible influence on RBC filterability. In conclusion, the osmotic effect of CM on RBC filterability is more predominant than the other CM effects, and iomeprol is the preferred CM for RBC filterability.

Adult↗
PubMed1992

Circular dichroic evidence for regulation of enzymatic activity by nonsubstrate hydrophobic ligand on glutathione S-transferase P.

1-Anilinonaphthalene-8-sulfonic acid (ANS) noncompetitively inhibited enzyme activity of glutathione S-transferase P for both glutathione and 1-chloro-2,4-dinitrobenzene (Ki = 30 microM). Dissociation constant for ANS.GST-P complex calculated from the binding study was 15 microM. From the similar values of the inhibition constant and the dissociation constant, it was concluded that specific ANS binding caused the loss of enzyme activity. In the protein structural analysis by circular dichroism, the secondary structures remarkably changed by ANS binding in accordance with the decrease of enzymatic activities. The conformational change of the protein and the decrease in enzymatic activity were reversed by dissociation of ANS. This fact strongly suggested that the enzymatic activity was regulated by a nonsubstrate hydrophobic ligand.

Anilino Naphthalenesulfonates↗
PubMed1992

Characterization of cysteine residues of glutathione S-transferase P: evidence for steric hindrance of substrate binding by a bulky adduct to cysteine 47.

Glutathione S-transferase P (GST-P) lost the enzymatic activity by 7-fluoro-4-sulfamoyl-2, 1, 3-benzodiazole (ABD-F), a thiol-group chemical modifier, but did not by methylmethanethiol-sulfonate. Both ABD-F and methylmethanethiolsulfonate reacted with Cys47 and Cys101. These two cysteine residues were site-directedly mutated with serine residues. Only the Cys101Ser lost the enzymatic activity by the treatment of ABD-F. On carbon 13 NMR experiments, a NMR signal of S-[13C]CH3 adduct to Cys47 did not show any change by the addition of S-hexylglutathione. These facts revealed that Cys47 did not locate at the active site, and a bulky adduct to Cys47 hindered the binding of substrates to the active site.

Amino Acid Sequence↗
PubMed1992

Hemoglobin-binding site on human haptoglobin. Identification of lysyl residues participating in the binding.

The locus of human haptoglobin (Hp) molecules that interacts with human hemoglobin (Hb) was examined by the differential labeling technique. First, amino groups of Hp were extensively labeled with ethyl acetimidate (EAI) either in the free state (experiment A) or in the equimolar complex with Hb (experiment B). Each of the labeled Hp samples was reduced and S-carboxymethylated, and the remaining amino groups were then allowed to react with trinitrobenzenesulfonic acid (TNBS) under denatured conditions. Only 0.6 mol/mol of the trinitrophenyl (TNP) group was introduced into the heavy chain of Hp in experiment A, whereas 2.5 mol/mol of TNP groups were into the same chain in experiment B. The extent of TNP modification for the light chain was very low in either of the experiments. The amino acid residues carrying TNP groups in the heavy chain were identified by the peptide mapping procedure. They were Ile1, Lys136, and Lys218 in experiment B, and only Ile1 in experiment A. These findings suggest that epsilon-amino groups of Lys136 and Lys218 in the heavy chain are both situated within the Hb-binding locus of Hp, and that the alpha-amino group of Ile1 is buried inside the molecule either in the presence or absence of Hb.

Amino Acid Sequence↗