Search PubMed⌕ Search

Biomedical subjects

T Kumazaki

Publications and source records attributed to T Kumazaki.

At least 145 records · Page 8Linked to original sources
PubMed1994

[Thrombosed type aortic dissection showing changes in the false lumen to the patent type].

Thirty-four patients with acute aortic dissection with thrombosed false lumen were reviewed. In 4 cases (12%), the false lumens changed to the patent type. Changes in the false lumens were revealed by contrast-enhanced CT performed from day 2 to day 19 (mean, day 12.5) after the onset. The entry site was located at the descending aorta in 3 cases, and was unknown in 1 case. In 2 cases, the entry site corresponded with ulcer-like projections that had been pointed out at the thrombosed false lumen. One patient presented with moderate back pain when the false lumen changed, while the others were symptom free. During the follow-up period, 2 patients died of rupture of the false lumen. One patient was treated with a surgical operation. The patent false lumen became re-thrombosed in 1 patient. Although the majority of cases of thrombosed aortic dissection are considered to have a good prognosis, some cases change to the patent type without clinical symptoms. Radiologists should be aware of the unstable nature of the thrombosed type aortic dissection, and follow-up examinations should be performed at least once a week for three weeks after the onset of dissection.

Acute Disease↗
PubMed1994

[Three-dimensional imaging of portal and hepatic veins using helical CT with intravenous injection of contrast medium].

The authors developed a simple new method for obtaining three-dimensional helical CT images that simultaneously depict both the portal and hepatic veins. One hundred ml of contrast medium was injected intravenously, and helical CT was carried out. Three-dimensional venous images were successfully displayed with rotational movement on the CRT monitor. The new method provided high-quality images in which the anatomical relationship between the portal and hepatic venous systems could be clearly visualized. This information was useful in helping angiographers to successfully perform transjugular intrahepatic portosystemic shunt and will be of great value for the presurgical planning of hepatic resection.

Adult↗
PubMed1994

Assignment of disulfide bonds in gp64, a putative cell-cell adhesion protein of Polysphondylium pallidum. Presence of Sushi domains in the cellular slime mold protein.

The 64-kDa membrane-bound glycoprotein of the cellular slime mold Polysphondylium pallidum (referred to as gp64), seems to be implicated in cell-cell adhesion. Previously we have isolated a full-length gp64 cDNA, determined its nucleotide sequence, and found that all cysteine residues in the protein are involved in the formation of disulfide bonds. The disulfide arrangement of the 36 cysteines in gp64 was established by analysis of proteolytically cleaved protein and sequence analysis of cystine-containing fragments. Since gp64 has 36 Cys residues, 18 disulfide bonds must exist and the positions of 15 of them were determined. The 15 disulfide bonds in gp64 constitute five characteristic, so-called Sushi domains. In a Sushi domain, the first Cys in a sequence is connected to the third one and the second Cys to the fourth one. This is the first report describing the presence of Sushi domains in a cellular slime mold protein. From these data, gp64 appears to be distinct from all other previously described cell-adhesion proteins.

Amino Acid Sequence↗
PubMed1994

[Evaluation of bone marrow by opposed phase T1-weighted images and enhanced MR imaging].

We investigated bone marrow in a control group, cases of aplastic anemia and post-irradiation patients by examining T1-weighted (T1WI), short TI inversion recovery (STIR), opposed phase T1WI (op-T1WI) and Gd-DTPA enhanced op-T1WI images obtained by 0.5T MRI. Bone marrow was classified into four types based on MR findings. Normal marrow showed low intensity on op-T1WI and STIR images without enhancement (I). Fatty marrow, which showed high intensity on T1WI and op-T1WI images was observed in aplastic anemia and post-irradiation patients (II). Hematopoietic marrow (III) showed low intensity on op-T1WI and enhanced, while active hematopoietic marrow (IV) revealed high intensity on both STIR and op-T1WI images and was enhanced following Gd-DTPA infusion. Aplastic anemia of moderate grade included types II, III and IV. Enhanced MR was needed to differentiate between types I and III since both types showed low intensity on op-T1WI images. Furthermore, type IV was considered as hyperplastic compared with type III. Enhanced MR and op-T1WI images were useful in evaluating hematopoiesis of bone marrow.

Adolescent↗
PubMed1994

[Changes in renal function immediately after the angiography].

The effect of radiographic contrast media upon renal function was investigated in 30 patients with normal renal function using Ioxaglate 320 mgI/ml (0.58 Osm/KgH2O), Iohexol 350 mgI/ml (0.88 Osm/kgH2O) and Iomeprol 400 mgI/ml (0.75 Osm/kgH2O). Before and immediately after conventional abdominal angiography, serum and urinary BUN, creatinine, sodium, osmolality and urinary volume were examined. Urinary minute volume increased remarkably immediately after angiography in all the contrast media groups. In Iohexol 350 and Iomeprol 400, creatinine clearance (Ccr) increased immediately after angiography, while no Ccr increase was observed in Ioxaglate 320. FENa increased immediately after angiography in all the contrast media groups. There were no statistical differences in the changes of FENa among Ioxaglate 320, Iohexol 350 and Iomeprol 400. There was no significant change in CH2O. It becomes evident that the osmotic diuresis and its effect on the proximal tubular function are induced by administrated low osmolar contrast media and that these changes are reversible.

Adult↗
PubMed1994

[Usefulness of dynamic subtraction CT for intracranial high density lesions].

Dynamic subtraction CT (DSCT) using a high speed Rotate/Rotate CT Scanner (Toshiba Xforce) was performed on 10 patients with intracranial high density lesions such as brain tumors and vascular malformations. In comparison with conventional contrast enhanced CT, the technique of dynamic subtraction CT enabled us to evaluate more clearly the contrast enhancement of high density lesions and to separate more easily the lesions from hematoma and calcification, which are shown as avascular areas. The results suggest that DSCT is a valuable method for evaluating the contrast enhancement of intracranial high density lesions.

Adult↗
PubMed1994

Molecular cloning and the COOH-terminal processing of gp64, a putative cell-cell adhesion protein of the cellular slime mold Polysphondylium pallidum.

The cellular slime mold Polysphondylium pallidum expresses a cell surface glycoprotein (referred to as gp64), which seems to be implicated in cell-cell adhesion. We identified a near full-length gp64 cDNA (1,104 base) upon screening a P. pallidum lambda gt11 library with a monoclonal antibody. The open reading frame encodes a protein of 320 amino acids with a molecular mass of 32,752 Da; the protein includes hydrophobic segments at both a NH2- and a COOH-terminal ends. By an Edman degradation analysis of S-pyridylethylated gp64 and its COOH-terminal peptide, it was found that the NH2- and COOH-terminal segments are both removed from the precursor protein of gp64. The COOH-terminal segment was isolated from a lysyl endopeptidase digest of gp64 by an affinity method. The COOH-terminal segment was identified at positions 266-279 in the primary sequence deduced from the cDNA sequence. The mature gp64 consisted of 279 amino acid residues and extremely rich in Cys residues (36 Cys/279 amino acids = 12.9%). Although there was already maximal accumulation of gp64 mRNA in vegetative cells, the protein reached a maximal level during aggregation stage, decreased, and then leveled off through the developmental cycle.

Amino Acid Sequence↗
PubMed1994

Aging- and growth-dependent modulation of endothelin-1 gene expression in human vascular endothelial cells.

Earlier we reported the undetectable level of endothelin (ET)-1 mRNA in aorta from young donors, in contrast to the detectable levels in older donors (Lab. Invest. 67, 210-217, 1992). We also found that the synthesis of ET-1 peptide is elevated in cultured endothelial cells from the aorta of over-50-year-old donors. In the present report, we show by in situ hybridization that the level of ET-1 mRNA is not so different in aortic endothelial cells from 5- and 50-year-old donors, but increases in cells from 76-year-old donors. The parallel results are obtained from Northern and in situ hybridization analyses by using serially passaged human umbilical vein endothelial cells. Thus, the increase of ET-1 peptide synthesis is achieved mainly at the level of mRNA. Furthermore, these results suggest that the increased expression of ET-1 in elderly people is due to the exhaustion of cell division potential of endothelial cells in vivo. We have also analyzed whether the expression of ET-1 is affected by the growth state. The data show that sparsely growing cells secrete more ET peptide than confluent and stationary cells. In situ hybridization also shows that S-phase cells express more ET-1 mRNA than non-S-phase cells. Thus, it is suggested that there are, at least, two ways for upregulation of ET-1 expression.

Aged↗
PubMed1994

Inhibition of Streptomyces griseus metallo-endopeptidase II (SGMPII) by active-site-directed inhibitors.

Inactivation of Streptomyces griseus metallo-endopeptidase II (SGMPII) by ClCH2CO-DL-(N-OH)Leu-OCH3 and by ClCH2CO-DL-(N-OH)Leu-Ala-Gly-NH2 was studied kinetically. These reagents cause irreversible inhibition of the enzyme in a pseudo-first order reaction, and the inhibition reaction exhibits saturation kinetics. The second-order rate constants for inactivation of SGMPII by ClCH2CO-DL-(N-OH)Leu-OCH3 and by ClCH2CO-DL-(N-OH)Leu-Ala-Gly-NH2 were measured to be 0.12 and 8.9 M-1.s-1, respectively. The order of affinities of metallo-endopeptidases towards these irreversible inhibitors is thermolysin > SGMPII > Pseudomonas aeruginosa elastase. A competitive inhibitor of SGMPII, L-Val-L-Trp, protects the enzyme against inactivation by ClCH2CO-DL-(N-OH)Leu-Ala-Gly-NH2 in a competitive manner. Furthermore, the pH profile of the inactivation closely resembles that for the hydrolysis of synthetic peptide substrates by the enzyme. These findings suggest that these reagents bind reversibly and react irreversibly at the active site of the enzyme.

Amino Acid Sequence↗
PubMed1994

Identification of the reactive site of ascidian trypsin inhibitor.

A trypsin inhibitor from hemolymph of the solitary ascidian, Halocynthia roretzi, has been reported to be present in two forms, ATI-I and ATI-II. ATI-I consists of a single polypeptide chain with a unique sequence of 55 amino acid residues, while ATI-II has two chains that seem to be derived from ATI-I by cleavage at the Lys16-Met17 bond [Kumazaki, T., Hoshiba, N., Yokosawa, H., and Ishii, S. (1990) J. Biochem. 107, 409-413]. ATI-II (as modified inhibitor) was proved to be produced by incubation of ATI-I (as virgin inhibitor) with a catalytic amount of bovine trypsin. The tryptic hydrolysis at the Lys16-Met17 bond in virgin inhibitor showed a maximum velocity at around pH 3.5. On the other hand, acid treatment of a complex prepared by mixing equimolar quantities of trypsin and the the modified inhibitor yielded free trypsin and the virgin inhibitor. The results of chemical analyses indicated that the Lys16-Met17 bond that had been cleaved in ATI-II was resynthesized by the acid treatment. These findings strongly suggest that the Lys16-Met17 bond is the reactive site of ATI for trypsin.

Amino Acid Sequence↗
PubMed1994

[An evaluation of coronary artery lesions of Kawasaki disease and congenital heart disease using rotary three dimensional digital cardiovascular angiography].

Congenital heart disease and the coronary artery lesions of children suffering from Kawasaki disease were evaluated by cardiovascular angiography using a newly developed rotary three-dimensional digital angiography method, and the usefulness of the device was examined. This method enable the observation of lesions from 144 directions within a 180 degree range depicting an image from optimal directions. In addition, the radiation exposure during one angiography was about one fifth of that of conventional cineangiography. With regard to the lesions of the coronary artery, identification of the localization of the stenotic lesions were made possible, especially at bifurcations, or the stenotic lesions overlapping with other bifurcations or coronary artery aneurysms as well as the structure at the ostium of the left and right coronary arteries, which were difficult to identify using conventional coronary artery angiography. For the case of patient ductus arteriosus or major aortopulmonary collateral artery (MAPCA), separation and imaging of the overlap with other blood vessels through the three-dimensional observation became possible. This method is effective for the evaluation of the site, direction and morphology of these arteries. With regard to stenosis of the right ventricular outflow tract, the morphology and the degree of stenosis could be evaluated more accurately than by conventional cineangiography. In addition, the images matched well with the operative findings. This method was also effective for the diagnosis and evaluation of the stenosis at the main pulmonary artery and stenosis of the bifurcation of the right and left pulmonary arteries overlapping with the main trunk of the pulmonary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Gallbladder visualization on CT shortly after angiography with ioxaglate.

Thirty-five patients underwent CT examination 15 to 30 min after abdominal angiography with ioxaglate. The gallbladder was visualized in 12 patients in the absence of clinical evidence of renal impairment. Gallbladder opacification on CT examinations shortly after angiography shows that the hepatobiliary tract is important in the excretion of ioxaglate.

Adult↗
PubMed1994

[An experience of transjugular intrahepatic portosystemic shunt in the treatment of gastroesophageal varices].

Transjugular intrahepatic portosystemic shunt (TIPS) using an 8-mm Gianturco-Rösch Z stent was performed in 10 patients with liver cirrhosis admitted due to ruptured gastroesophageal varices. The treatment was successful in 9 patients, and the portal pressure decreased form 25 mmHg to 17 mmHg immediately after TIPS and to 15 mmHg 2 weeks after TIPS. The patency of the shunt was maintained adequately in the patients examined 3 months after TIPS. Endoscopy 1 month after TIPS showed improvements in the gastroesophageal varices in all patients. Hemobilia and intraperitoneal bleeding were observed in 1 patient each during procedure. Transient jaundice was observed in 2 and increase in the blood ammonia level were noted in 3 (one of whom had hepatic encephalopathy) postoperatively. All these complications could be treated easily. TIPS which brings about an immediate marked reduction in the portal pressure appears to be promising as a new treatment for portal hypertension.

Adult↗
PubMed1994

[Assessment of left ventricular function with 99mTc-MIBI gated myocardial SPECT using 3 head rotating gamma camera].

Twenty-one patients with ischemic heart disease were studied by resting 99mTc-methoxyisobutyl isonitrile (MIBI) gated SPECT images using a 3 head rotating gamma camera (Picker/Shimadzu: PRISM 3000). The data were acquired over 360 degrees in 20 (x 3) steps, each of which was 70 beats. The systolic wall thickening index (%WT) was calculated as (ES count-ED count/ED count x 100), using the circumferential profile analysis of ED and ES short axial images. The %WT was correlated well with LVEF obtained from contrast ventriculography (r = 0.85, n = 17). By using high speed (3 head) rotating gamma camera, we have shortened the time of collecting MIBI gated SPECT data, and this method can provide useful information on ventricular function.

Female↗
PubMed1994

[Correlation of serial MRI and histological findings following intra-tumor local chemotherapy for malignant brain tumor].

Serial magnetic resonance imaging (MRI) studies on patients with malignant brain tumor after postoperative adjuvant therapy have been rarely reported. Leukoencephalopathy after such treatment is a well-known serious adverse effect, which we studied by serial MRI after postoperative adjuvant therapy in 15 patients with malignant brain tumors (anaplastic glioma 6, astrocytoma Grade III 5, astrocytoma Grade II 2, and metastatic brain tumor 2) (Table 1). All patients were examined by MRI, more than twice postoperatively. Adjuvant therapy was as follows: adriamycin (ADM) (0.5 mg) was injected through Ommaya reservoir into the tumor bed at the craniotomy. The usual total dose of ADM was 5.0 mg. In three of 15 patients, local methotrexate chemotherapy was added. Fourteen patients received a course of local irradiation 58 Gy on average combined with local ADM chemotherapy. Histological findings of three autopsy cases and ten reoperated ones were correlated with the serial MRI. Consecutive MRI were examined one and three months after adjuvant therapy. The results were as follows: One month after adjuvant therapy, thin and high signal intensity areas could be seen in the marginal zone of the tumor cavity on the gadolinium-enhanced T1-weighted MRI. High signal intensity areas could also be seen in the operative cavity on the T1-weighted MRI, which were suspected to be residual hematomas. In one patient, a high, diffuse and widespread signal area could be seen on T2-weighted MRI, suggesting leukoencephalopathy. Three months after adjuvant therapy, a high thick signal intensity area could be seen in the marginal zone of the tumor cavity and along the route of the Ommaya tube on the gadolinium-enhanced T1-weighted MRI, but there was no mass effect in these space taking lesions. In five cases, a low signal intensity area could be seen in the porencephalic cystic lesion, in one of which septum formation of cystic cavity was detected on the gadolinium-enhanced T1-weighted MRI. Morphologically, there was massive coagulation necrosis in the tumor cavity, but in the vicinity of the cystic wall abundant fibrous connective tissue was found to correspond with the high and thick signal intensity area on the above-mentioned gadolinium-enhanced T1-weighted MRI.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

[CT and MR imaging of post-aortic left brachiocephalic vein].

The usefulness of CT and MR imaging (MRI) for the diagnosis of post-aortic left brachiocephalic vein (PALBV) is discussed. The subjects of the present study consisted of five patients with PALBV, two males and three females, aged four months to sixty years. Chest CT and MRI were performed as a follow-up study of other intrathoracic lesions in two cases, and for further examination of congenital heart diseases in two infant cases. The other patient underwent both CT and MRI to evaluate sporadic chest pain. Therefore, all PALBV were found incidentally. PALBV passes below the aortic arch in front of the trachea, draining the superior vena cava behind the ascending aorta. This finding was particularly well documented on consecutive coronal sections on MRI. In patients with intrathoracic malignant or specific inflammatory lesion, differentiation between PALBV and lymphadenopathy is necessary for treatment. From our experience, marked enhancement on CT and no signal intensity on MRI in PALBV could differentiate this anomaly from mediastinal lymphadenopathy. In two infantile cases with congenital cardiovascular anomalies such as tetralogy of Fallot, right aortic arch and pulmonary arterial stenosis, MRI was found to be superior to CT in demonstrating these anomalies.

Adult↗