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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 559 records · Page 31Linked to original sources
PubMed1984

[Echocardiographic manifestations of postinfarction perforation with extensive dissection of the interventricular septum: report of an autopsied case].

This is a report of the echocardiographic features of postinfarction perforation associated with dissection of the interventricular septum (IVS) in a 61-year-old woman. She had acute myocardial infarction and was admitted to a nearby hospital, and later admitted to our CCU because hemodynamic deterioration. On admission, she was somnolent and hypotensive (90/64 mmHg), with sinus tachycardia, marked cyanosis, and peripheral edema. On auscultation there were a harsh holosystolic murmur over the LLSB and moist rales in both lung fields. An ECG revealed extensive anterior and inferior infarctions. Catheterization data confirmed O2 step-up in the right ventricle. Two-dimensional echocardiograms demonstrated extensive dissection of the IVS characterized by an echo-free lumen extending from the apex to the cardiac base in the long-axis and partly reaching the left ventricular free wall in the short-axis with the concomitant paradoxical movement of the IVS. Autopsy disclosed marked hemorrhagic infarction and extensive dissection of the IVS forming a lumen (5 X 5.5 X 2 cm3) corresponding exactly to the echocardiographic free space. In addition, a shunt between the right and left ventricles was confirmed by the presence of two perforations near the apex on the right and left sides of the IVS, whose diameters were 6 and 10 mm, respectively.

Cardiomyopathies↗
PubMed1983

Hepatocellular carcinoma. A clinical and pathologic analysis of 57 hepatectomy cases.

The following is a clinicopathologic analysis of 57 hepatectomy cases of hepatocellular carcinoma (HCC). The rates of complication from precirrhosis and cirrhosis were 33.3% each. Cirrhosis seemed to have preceded HCC in 13 cases (39.4%) and both diseases appeared to have developed simultaneously in 18 cases (54.5%). Growth patterns of HCC were related to histologic features of livers bearing HCC: HCCs occurring in normal livers were significantly larger in average tumor size than those occurring in cirrhotic livers (9.2 as compared to 4.7 cm) and tended to exhibit a microtrabecular growth pattern (83% of the cases), while HCCs occurring in cirrhotic livers were most commonly macrotrabecular (67%). The factors most significantly influencing survival were the smallness of removed liver and tumor, histologic grades, the presence of bile production, and the absence of satellite tumors and giant cells. The positivity rates of serum hepatitis B virus (HBV) surface antigen averaged 47.2% and the relation of HCC to the role of HBV in the pathogenesis of HCC was discussed.

Adult↗
PubMed1983

The inferior right hepatic vein: ultrasonic demonstration.

The inferior right hepatic vein (IRHV) was demonstrated sonographically in 27 out of 269 patients (10%). It was shown to be thicker than the right hepatic vein in 8 (3%). In 2 patients, two accessory right hepatic veins were demonstrated, with one being the IRHV and the other the middle right hepatic vein. Delineation of the IRHV is significant in hepatectomy, detection of tumor thrombus in hepatocellular carcinoma, Budd-Chiari syndrome, and dilatation of the intrahepatic bile ducts.

Bile Ducts, Intrahepatic↗
PubMed1983

Inhibitory effect of human interferons on lymphocyte proliferation induced by phytomitogens in cynomolgus monkeys (Macaca fascicularis).

In order to study the comparative cross-reactivity of human interferon (Hu-IFN) with cynomolgus monkeys, the effect of Hu-IFN on the immune responses of monkeys was assessed by measuring lymphocyte transformation induced by phytomitogens. The in vivo administration of Hu-IFN or its placebo to monkeys resulted in transient neutrophilia, but no significant alteration of the kinetics of T lymphocytes in the peripheral blood. Lymphocyte proliferation of Hu-IFN-injected monkeys showed a significant reduction depending on their serum Hu-IFN titers, whereas no significant decrease was observed in monkeys injected with placebo. The in vitro incubation of monkey lymphocytes with Hu-IFN before or simultaneously with the addition of phytomitogens caused a substantial decrease in the lymphocyte proliferative responses in a dose-dependent manner. However, the inhibitory effect was no longer observed when Hu-IFN was added 24 h after incubation of lymphocytes with phytomitogens. Hu-IFN also suppressed the blastogenic responses of lymphocytes pulsed with phytomitogens before the addition of Hu-IFN. Addition of peritoneal macrophages pretreated with Hu-IFN failed to exert any significantly different effect on the lymphocyte proliferation compared to untreated ones. Taken together, the inhibitory effect of Hu-IFN seemed to act directly upon the early phase of lymphocyte proliferation induced by phytomitogens. These findings indicate that cynomolgus monkeys were susceptible to Hu-IFN both in vitro and in vivo with respect to the inhibitory effect on lymphocyte proliferation and could serve as a useful experimental model to study the effect of Hu-IFN on the immune responses.

Animals↗
PubMed1983

Ultrasonic characteristics of the small hepatocellular carcinoma.

Fifty five small hepatocellular carcinoma less than 5 cm in diameter among 41 patients were examined by linear arrayed electronic scanning system with 3.5 MHz transducer. Characteristics of the sonogram were enhanced posterior echoes of the tumor, mosaic pattern of internal echoes, halo and lateral shadows. These findings are appeared in 69%, 64%, 35% and 22% of tumors respectively. Among 45 tumors from 2.1 cm to 5 cm in diameter, these findings are appeared in 81%, 73%, 40% and 24% respectively. Among 10 tumors less than 2 cm in diameter, these characteristics were rare and these minimal hepatocellular carcinomas were demonstrated as a simple low echo area. Fifty tumors in 39 patients were resected. Lobulation of the hepatocellular carcinoma on the cut surface of the resected specimen and mosaic pattern on the sonogram are closely connected with each other. Thin fibrous capsule of the hepatocellular carcinoma corresponded to halo and lateral shadows. Posterior echo enhancement was due to the softness of the hepatocellular carcinoma. By those four characteristics, hepatocellular carcinoma can be differentiated from hemangioma and metastatic liver tumor.

Carcinoma, Hepatocellular↗
PubMed1983

Intraoperative ultrasonic examination for hepatectomy.

Intraoperative ultrasonic examination (IUE) was performed on 118 patients who were laparotomized for hepatectomy with five types of specially designed real-time linear array transducers. Many lesions which were invisible and nonpalpable from the surface of the liver were present in 58% of patients. All these lesions were detected by IUE. Among 16 tumors in 13 patients, IUE demonstrated 11 tumor thrombi (69%). By angiography, definite and equivocal diagnosis was made only in six tumor thrombi. Systematic subsegmentectomy was performed in 41 cases. The new concept of partial hepatectomy was accomplished by IUE. IUE is an indispensable operative procedure for hepatectomy.

Carcinoma, Hepatocellular↗
PubMed1983

[Development on segmentectomy and subsegmentectomy of the liver due to introduction of ultrasonography].

Due to introduction of preoperative and intraoperative ultrasound into liver surgery, three dimensional structure of the liver is understood much better than before. Intraoperative sonography demonstrated many daughter nodules and tumor thrombi which were not detected preoperatively. Therefore, a part of noncurative resection of the liver can be avoided. In patients with liver cirrhosis and small hepatoma, 60 per cent of hepatomas could not be visible nor palpable from the surface of the liver. In these patients, if hepatic lobectomy is performed, liver dysfunction will develop after surgery. Therefore, small partial resection is indicated and identification of site of the tumor is indispensable. With intraoperative sonography, all invisible and nonpalpable tumors in the liver were demonstrated. Clinicopathological studies of the hepatocellular carcinoma suggest that the tumor cells spread in the liver through the portal venous branches even in the small hepatocellular carcinoma. Daughter nodules will grow in the distal region of the portal venous branch. Therefore, total resection of the subsegment which contains the tumor is indicated. For this purpose, systematic subsegmentectomy is considered. In this operation, portal area containing tumor is identified by ultrasonically guided puncture of the portal venous branch. By identification of the inferior right hepatic vein, the right postero-inferior area can be preserved, even if right hepatic vein is resected. This type of hepatectomy is called inferior right hepatic vein preserving operation. We already performed this operation in three patients.

Carcinoma, Hepatocellular↗
PubMed1983

H-2 I region restriction phenomenon in T cell-dependent granuloma formation to Mycobacterium bovis BCG.

We examined the involvement of the T cell recognition system in hepatic granuloma formation in nude mice infected with Mycobacterium bovis BCG and subsequently injected with spleen cells. After syngeneic spleen cell transfer, granuloma was seen in nude mouse strains of several different genetic backgrounds. When allogeneic spleen cells were transferred, only those from mice that were H-2 I-region compatible with the recipients induced granuloma formation. Adoptive transfer of BCG-immunized spleen cells to splenectomized BCG-infected nude mice also showed H-2 K-end restriction. The effect of graft-versus-host (GVH) reaction on the generation of immune T cells was examined by time course observations after transfer of H-2-compatible and -incompatible allogeneic spleen cells and by cotransferring allogeneic and syngeneic spleen cells. Under these conditions, H-2-compatible sensitized T cells were generated. The fate of completely allogeneic T cells in nude mice was examined by double transfer experiments. Allogeneic spleen cells were recovered 3, but not 8 or more, days after the transfer.

Animals↗