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Biomedical subjects

S Hori

Publications and source records attributed to S Hori.

At least 19 recordsLinked to original sources
PubMed1992

[MR imaging evaluation of plica synoviallis mediopatellaris of the knee joint].

To evaluate the diagnostic ability of MR imaging for plica synoviallis mediopatellaris (PSM), we retrospectively reviewed the MR imaging findings of patellofemoral space in 20 knee joints of 11 patients. In all 20 knee joints, arthroscopy and MR imaging were available. MR imaging was performed with a 1.5 Tesla Magnetom (Siemens) using a round surface coil. Pulse sequences were SE (TR 600 ms/TE 26 ms), SE (TR 200 ms/TE 26, 70 ms) and FLASH (TR 450 ms/TE 15 ms/FA 90 degrees). In six of the 20 knees with PSM proved by arthroscopy, a low intensity band was shown above the medial condyle of the femur on both T1- and T2-weighted MR images, and on FLASH images this band was shown as intermediate intensity. In the other 14 knees with no PSM observed by arthroscopy, the low intensity band was not shown on MR imaging. In all 20 knees, a similar low intensity band was shown about 1 cm cranial to the medial condyle of the femur. This should not be diagnosed as PSM. The low intensity band seen on T1- and T2-weighted MR images and its anatomical relation to the medial condyle are important in diagnosing PSM.

Adolescent↗
PubMed1992

[Dynamic 3DFT FISP MR imaging of hepatocellular carcinoma].

Dynamic 3 dimensional Fourier transformation (3DFT) FISP MR imaging was performed in 5 patients with hepatocellular carcinoma before partial hepatectomy. Immediately after 0.1 mmol/kg of Gd-DTPA was administered intravenously, 3DFT FISP images (TR/TE/flip angle/slice thickness, 20 msec/8 msec/30 degrees/2-4 mm) were obtained every 30 seconds until 150 sec. We correlated dynamic MR images of the 5 patients with gross and microscopic findings. Some regions in the tumor corresponding to viable cells showed high intensity enhancement and other regions corresponding to necrotic regions showed no enhancement on the early phase images. We concluded that dynamic 3DFT FISP MR imaging which had good spatial resolution was useful in evaluating the vascularity of the tumor.

Aged↗
PubMed1992

[Differentiation between hepatoma and hemangioma by inversion recovery snapshot FLASH MR imaging with variable TIs].

To differentiate hepatoma from hemangioma, MR studies were performed for 18 patients with 21 untreated liver tumors (hepatoma 10, hemangioma 11). We obtained inversion recovery snapshot FLASH images of liver tumors with variable TIs (50, 100, 150, 200, 250, 300, 400, and 500 msec). 8 hemangiomas showed higher intensity than liver parenchyma on the images at 150 msec and less of TI, and lower intensity at 200 msec or more TI. In 7, signal intensity of hepatoma became low at 150 msec or less of TI or remained high with prolonged TI. Inversion recovery snapshot FLASH imaging with variable TIs will be useful for differentiating between hepatoma and hemangioma.

Adult↗
PubMed1992

Stimulation of anchorage-independent cell growth by endothelin in NRK 49F cells.

Endothelin (ET) is a vasoconstrictor peptide originally isolated from vascular endothelial cells. Recent studies have revealed that ET has many biological functions including growth factor-like activity. The present study aims to clarify whether ET-1 possesses the ability to stimulate anchorage-independent cellular growth, an indicator of factors with transforming activity. We found that NRK 49F cells possess a large number of high-affinity ET-1 receptors; labeled 125I-ET-1 binding was displaced by unlabeled ET-2 in a similar dose response, but in the case of ET-3, 100-fold more was required. Specific 125I-ET-3 binding was undetectable in NRK 49F cells, indicating that ET receptors in NRK 49F cells are ET-1/ET-2 selective. NRK 49F is a cell line which is most commonly used to assay for anchorage-independent cellular growth. Therefore, we explored whether ETs promote anchorage-independent cellular growth in this cell line. ET-1 and ET-2 stimulated NRK colony formation dose dependently in the presence of 1 nM epidermal growth factor (EGF). In contrast, ET-3 did not have colony-stimulating ability. In the presence of EGF, the maximal effect of ET-1 was approximately 90% of that of transforming growth factor-beta. Moreover, in the presence of maximal stimulating concentrations of EGF and transforming growth factor-beta, ET-1 additionally induced colony formation. These results indicate that ET-1 and -2 possess transforming growth factor-like activity for NRK 49F cells. Since ET-1 and -2 increased intracellular calcium levels, this ion may participate in signal transduction pathways by which ET-1 and -2 promote colony formation.

Animals↗
PubMed1992

[Regenerating nodules in liver cirrhosis--patho-MR-serological correlation study].

An MR study was performed in 73 clinically diagnosed cirrhotic patients to determine correlations among the demonstration of small low intensity nodules (SLINs), secondary changes due to cirrhosis, and serological data. In 32 patients, liver cirrhosis was proved histologically. SLINs were observed in 38 of the 73 patients on gradient echo (GRE) images and in 28 patients on T2-weighted SE images. Patho-MR correlation study of the liver in the 32 histologically proved cirrhotic patients revealed that SLINs were seen on GRE images only in patients with iron deposits in regenerating nodules (RNs). There was no significant correlation between secondary changes due to liver cirrhosis and the demonstration of SLINs. Serological data indicating liver cell injury and iron store in the body were significantly higher in patients with iron deposits in RNs than in those without iron deposits.

Adult↗
PubMed1992

Cell-cell interaction in graft rejection responses: induction of anti-allo-class I H-2 tolerance is prevented by immune responses against allo-class II H-2 antigens coexpressed on tolerogen.

The intravenous sensitization of C57BL/6 (B6) mice with class I H-2-disparate B6-C-H-2bm1 (bm1) spleen cells results in almost complete abrogation of anti-bm1 CD8+ helper (proliferative and interleukin 2-producing) T cell (Th) activities. Although an appreciable portion of CD8+ cytotoxic T lymphocyte (CTL) precursors themselves remained after this regimen, such a residual CTL activity was eliminated after the engrafting of bm1 grafts, and these grafts exhibited prolonged survival. In contrast, the intravenous sensitization with (bm1 x B6-C-H-2bm12 [bm12])F1 cells instead of bm1 cells failed to induce the prolongation of bm1 graft survival as well as bm12 and (bm1 x bm12)F1 graft survival. In the (bm1 x bm12)F1-presensitized B6 mice before as well as after the engrafting of bm1 grafts, anti-bm1 CTL responses that were comparable to or slightly stronger than those observed in unpresensitized mice were induced in the absence of anti-bm1 Th activities. bm1 graft survival was also prolonged by intravenous presensitization with a mixture of bm1 and bm12 cells but not with a mixture of bm1 and (bm1 x bm12)F1 cells. The capacity of CD4+ T cells to reject bm12 grafts was eliminated by intravenous presensitization with antigen-presenting cell (APC)-depleted bm12 spleen cells. However, intravenous presensitization with APC-depleted (bm1 x bm12)F1 cells failed to induce the prolongation of bm1 graft survival under conditions in which appreciably prolonged bm12 graft survival was induced. More surprisingly, bm1 graft survival was not prolonged even when the (bm1 x bm12)F1 cell presensitization was performed in CD4+ T cell-depleted B6 mice. This contrasted with the fact that conventional class I-disparate grafts capable of activating self Ia-restricted CD4+ as well as allo-class I-reactive CD8+ Th exhibited prolonged survival in CD4+ T cell-depleted, class I-disparate cell-presensitized mice. These results indicate that: (a) intravenous presensitization with class I- and II-disparate cells fails to reduce anti-allo-class I rejection responses that would otherwise be eliminated using only class I-disparate cells; (b) such failure is generated according to the coexpression of both classes of alloantigens on a single cell as tolerogen; and (c) allo-class II antigens coexpressed on tolerogen function to activate CD4+ as well as non-CD4+ Th leading to the generation of anti-class I effector T cell responses.

Animals↗
PubMed1992

Outcome of localized hepatocellular carcinoma treated with segmental arterioportal chemoembolization.

When lipiodol is injected into the hepatic artery at a dose exceeding a certain level, it flows into the portal vein. On the basis of this feature, an emulsion of Adriamycin with lipiodol was injected into a segmental or subsegmental artery such that it was delivered to the portal vein of the same segment, and the artery was then embolized with Gelfoam. This segmental arterioportal chemoembolization (cement therapy) was performed in 50 patients with localized hepatocellular carcinoma. A posttreatment CT scan showed that almost 100% of the lesions were occupied by lipiodol. The cumulative survival values determined for the 50 patients were very high: 83.4% after 1 year and 62.7% after 2 years.

Adult↗
PubMed1992

Immunohistochemical study of transforming growth factor beta, fibronectin, and fibronectin receptor in invasive mammary carcinomas.

Thirty-one cases of mammary carcinoma were examined immunohistochemically for the expression of transforming growth factor (TGF) beta, fibronectin (FN) and fibronectin receptor (FNR) in order to clarify the reason for the reported relationship between TGF beta expression and a high incidence of lymph node metastasis. It was revealed that TGF beta expression is closely related to the expression of FN, an intercellular matrix protein, and its cellular receptor FNR, one of the integrins. The interaction between FN and FNR in a tumor is considered to form the basis of the invasive nature of carcinoma cells. Thus, it is suggested that TGF beta expression in carcinoma cells induces the interaction between FN and FNR, which may lead to carcinomatous invasion resulting in lymph nodal metastasis.

Adult↗
PubMed1992

Prolonged QT interval in alcoholic autonomic nervous dysfunction.

QT prolongation on electrocardiography is related to sudden cardiac death and is frequently found in alcoholics. We studied QT prolongation in relation to the function of cardiac autonomic nerves assessed by the coefficient of variation of the R-R interval (CVRR) in three age-matched groups of men: 32 alcoholics with autonomic nervous dysfunction (AN), 32 alcoholics without AN, and 32 healthy controls. The QTc interval and CVRR were measured at rest on the 30th day of abstinence, when electrolyte imbalance had disappeared. Subjects with arrhythmia, conduction abnormality, cardiomegaly, ischemic heart disease or diabetes mellitus were excluded. A CVRR of less than 80% of standard predicted value was judged to represent AN. In alcoholics, QTc correlated negatively with the ratio of CVRR to its standard value (r = -0.49, p < 0.0001). The incidence of QTc prolongation was higher in alcoholics with AN (46.9%) than in alcoholics without AN (21.9%, p < 0.05). QTc prolongation was not observed in healthy controls. The QTc interval was significantly (p < 0.01) longer in alcoholics with AN (444 +/- 20 msec) than in alcoholics without AN (426 +/- 17) and in healthy controls (398 +/- 18). These results suggest that alcoholism causes dysfunction of the autonomic nerves as well as worsening QT prolongation, and this may predispose such patients to sudden cardiac death.

Adult↗
PubMed1992

CT of gastric carcinoma: preliminary results with a new scanning technique.

Usefulness of computed tomography (CT) for the demonstration of gastric carcinoma was evaluated in 250 cases with surgical proof of diagnosis: advanced gastric carcinoma (n = 193), early gastric carcinoma (n = 47), gastric submucosal tumor (n = 8), gastric polyp (n = 1), and benign gastric ulcer (n = 1). CT was performed on prone patients after 400-600 mL of water was orally administered and a 100-mL bolus of nonionic contrast material was injected. Water provided optimal distention and satisfactory contrast to depict the normal gastric wall. Prone positioning allowed visualization of the whole gastric wall except for the fundus and prevented artifacts caused by gas during supine imaging. CT demonstrated gastric tumor as a thickened or abnormally enhanced gastric wall in 95% of advanced carcinomas, 93% of elevated early carcinomas, and 18% of depressed early carcinomas. The authors believe that CT performed with this method is useful and that it should be used in addition to barium and endoscopic studies before surgery is planned.

Carcinoma↗
PubMed1992

Augmented plasma protein C activity after coronary thrombolysis with urokinase in patients with acute myocardial infarction.

Coronary thrombolysis reduces morbidity and mortality in patients with acute myocardial infarction, however, the exact effects of thrombolytic agents on the status of intrinsic hemostases are not fully understood. In the present study, we examined serial changes in plasma thrombin and protein C activities of 6 patients with acute myocardial infarction treated with urokinase. Fibrinolysis occurred immediately after urokinase injection with an increase in the plasma thrombin-antithrombin III complex, suggesting a subsequent procoagulant state due to thrombin generation. Correspondent increases in plasma protein C activity were observed, however, protein S levels did not change at all. Our findings suggest that urokinase administration for coronary thrombolysis not only causes fibrinolysis, but also induces thrombin activity, which may be antagonized by augmented intrinsic protein C activity.

Aged↗
PubMed1992

Distinct tissue distribution and cellular localization of two messenger ribonucleic acids encoding different subtypes of rat endothelin receptors.

Endothelins (ETs) are very potent vasoconstrictive peptides and have diverse functions in both vascular and nonvascular tissues. This investigation concerns the tissue distribution and cellular localization of rat mRNAs encoding two different subtypes of ET receptors (ETA and ETB). We isolated 46 cDNA clones from a rat lung cDNA library by hybridization with the bovine ETA cDNA. The characterization of these cDNA clones indicated that they represent either the ETA or ETB cDNA. In situ and blot hybridization analyses revealed that the rat ETA mRNA is predominantly expressed in vascular smooth muscle cells of a variety of tissues, bronchial smooth muscle cells, myocardium, and the pituitary gland. There is no significant expression of ETB mRNA in vascular smooth muscle cells, and ETA, thus, plays a primary role in ET-induced vascular contraction. ETB mRNA is more widely distributed in various cell types of many tissues. Its prominent expression is seen in glial cells throughout the brain regions, epithelial cells of the choroid plexus, ependymal cells lining the ventricle, myocardium, endothelial cells of glomeruli, and epithelial cells of the thin segments of Henle's loops. Our investigation demonstrates that the mRNAs for the two subtypes of rat ET receptors show specialized expression patterns of cell types in both brain and peripheral tissues.

Amino Acid Sequence↗
PubMed1992

Increased plasma endothelin in NIDDM patients with retinopathy.

OBJECTIVE: To elucidate the significance of ET in diabetic microvascular disease. RESEARCH DESIGN AND METHODS: We determined plasma levels of ir-ET-1 in 25 NIDDM patients without hypertension and/or renal dysfunction. RESULTS: The plasma levels of ir-ET-1 in NIDDM patients with simple (n = 8) and proliferative (n = 8) retinopathy were 0.58 +/- 0.04 pM and 0.60 +/- 0.04 pM, respectively, which were significantly higher than those in normal, nondiabetic subjects (0.24 +/- 0.02 pM [n = 31]) and NIDDM patients without retinopathy (0.30 +/- 0.05 pM [n = 9]). CONCLUSIONS: These results suggest that plasma ET-1 is related to diabetic microvascular disease.

Biomarkers↗
PubMed1992

Clinical effect of intra-arterial tumor necrosis factor-alpha for malignant glioma.

Recombinant human tumor necrosis factor-alpha was administered intra-arterially to treat 20 cases of malignant gliomas, mostly progressive or recurrent. The optimum dosage was determined to be 1 x 10(5) U/sq m/day. Among the 10 evaluable patients treated at this dosage, two responded (one completely and one partially), resulting in a 20% response rate. Side effects were mild and easily controllable. Improvement of neurological symptoms was noted in 47% of the patients a few days after treatment, even when computerized tomography showed no tumor regression. This might have been due to the pleiotypic biological activity of tumor necrosis factor-alpha. Neuroradiographic observations revealed narrowing of the tumor-feeding artery, a decrease in tumor staining ability, and necrosis in the central part of a tumor. The authors suggest that intra-arterial administration of tumor necrosis factor-alpha may be an effective treatment for malignant glioma, including recurrent cases.

Adolescent↗
PubMed1992

The morphological and biochemical changes in skeletal muscle fibers by dietary protein restriction.

The effects of dietary protein restriction on skeletal muscle fibers were studied according to morphological and biochemical approaches. Protein and DNA content of quadriceps muscles from young adult rats were decreased by the low protein and protein-free diet. Morphological examination demonstrated that there was a significant decrease in the size of muscle fibers without change in their numbers due to protein restriction. The protein/DNA ratio, accepted as an index of cell size in biochemical approaches, was compared with cell size on photomicrographs. Actual fiber size appeared much smaller than that indicated by the protein/DNA ratio.

Animals↗
PubMed1992

[Stage III, IV hepatocellular carcinoma patients surviving more than five years after transcatheter chemoembolization].

Twelve of the patients with advanced (Stage III or IV) hepatocellular carcinoma who received transcatheter chemoembolization survived for more than 5 years. These survivors consisted of 6 Stage III cases and 6 Stage IV cases. Of the 6 Stage III cases, 5 had multiple tumors (larger than 2 cm) in one lobe of the liver, and 1 had tumor invasion into the second portal branch before treatment. Of the 6 Stage IV cases, 4 had had multiple tumors in both lobes, and 2 had had tumor invasion into the main portal branches. Before treatment, 9 of the 12 survivors had been rated as Child's class A. Lipiodol was used in all 12 cases. The results of the present study suggest the usefulness of Lipiodol in treating advanced hepatocellular carcinoma.

Aged↗