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Biomedical subjects

Y Ishimaru

Publications and source records attributed to Y Ishimaru.

72 records · Page 4Linked to original sources

Outbreaks of hand, foot, and mouth disease by enterovirus 71. High incidence of complication disorders of central nervous system.

In Japan we have had two outbreaks of hand, foot, and mouth disease associated with disorders of the central nervous system, one in 1973 and the other in 1978. The isolated virus in both outbreaks was enterovirus 71. Central nervous system disorders were present in 24% of patients in 1973 and in 8% of patients in 1978. These disorders were localised encephalitis with cerebellar signs as the main feature, aseptic meningitis, and polio-like paresis. The enterovirus 71 isolated in Japan had strong dermatotropic as well as neurotropic tendencies. However in cross-neutralisation tests, no difference in antigenicity from the prototype, BrCr strain, was recognised.

Adolescent↗

A possible mechanism for island formation by rat ascites hepatoma cells with special reference to the function of aggregation factor at the cell surface.

Two tumor cell-aggregation factors of glycoprotein nature, separated from rat ascites hepatoma AH136B cells (forming cell islands in vivo), had different antigenicity; one was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. The unabsorbed factor induced aggregation (as shown in the form of simple apposition) of rat ascites hepatoma AH109A cells (present as a free form in vivo) and cell adhesiveness characterized by well-defined tripartite junctional complexes, including intermediate junctions, desmosomes, and tight junctions. In contrast, the absorbed factor from AH136B cells, AH109A cells or normal rat serum aggregated AH109A cells but failed to develop the junctional complexes; only simple apposition was observed. AH109A cells themselves contained the absorbed factor but not the unabsorbed factor. AH136B cells proliferating in the skin developed the junctional complexes, while AH109A cells proliferating in the skin did not from any junctional complexes.

Animals↗

Biochemical and morphological comparison of two tumour-cell-aggregation factors from rat ascites hepatoma cells.

Two tumour-cell-aggregation factors, derived from rat ascites hepatoma cells, had different antigenicity; one was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. Their activities were both lost by digestion with trypsin, but remained unchanged by oxidation with periodate, suggesting the role of the protein portions in their molecules. The potency of the unabsorbed factor was inhibited specifically by alpha-methyl-D-mannoside or D-mannose, while that of the absorbed factor was inhibited specifically by N-acetyl-D-glucosamine, suggesting that these carbohydrates may be concerned with the respective receptor structures at the tumour-cell surface. The unabsorbed factor induced not only cell aggregation (as shown in the form of simple apposition) but also cell adhesiveness characterized by development of intermediate junctions, desmosomes and tight junctions, while the absorbed factor produced only simple apposition, suggesting their functional difference.

Animals↗

Infantile papular acrodermatitis (Gianotti's disease) and intrafamilial occurence of acute hepatitis B with jaundice: age dependency of clinical manifestations of hepatitis B virus infection.

Infantile papular acrodermatitis (IPA, Gianotti's disease) is a clinical manifestation of hepatitis B virus (HBV) infection in childhood. An epidemic of of IPA occurred in Matsuyama, Japan, where 153 patients in a pediatric clinic had IPA between October 1974 and March 1977. In this period 12 mothers and two fathers of patients contracted acute hepatitis B with overt jaundice three to 14 months after their offspring had IPA. Analysis of the subtype of hepatitis B surface antigen (HBsAg) in the infants and their jaundiced mothers and/or fathers disclosed that HBV was transmitted from the infants. All of the index cases were one year old or younger, although the age of patients with IPA ranged from three months to 10 years. In approximately 40% of patients with IPA who were one year old or younger, HBs antigenemia persisted for one year. These facts suggested that the contraction of IPA in children, especially those one year old or younger, was an important route toward establishment of the carrier state of HBV which maintains the reservoir of this virus in the community.

Acrodermatitis↗

Ultrastructural changes of intercellular junctions in rat ascites hepatoma cells with calcium depletion.

To analyse the effect of ethylenediamine tetraacetate (EDTA) on tumour cell adhesiveness, fine structure of intercellular junctions of rat ascites hepatoma cells AH136B and AH7974 (both forming cell islands in vivo) was first compared. The close contact of the apical portion of both cell islands was composed of tight junctions with a narrow gap. The close contact of the inner portion of AH136B cell islands was largely by simple apposition, while that of AH7974 cell islands had many intermediate junctions and desmosomes. Treatment with EDTA (2 mM) induced morphological alteration of simple apposition, intermediate junctions and desmosomes, but tight junctions remained intact. The effect of EDTA on such junctional complexes seemed to be partially reversible on readministration of Ca ions. Changes in desmosomes, as confirmed on AH7974 cells, were initiated by disappearance of the central disc of electron-dense materials, followed by marked opening of intercellular space and disappearance of endoplasmic laminar plaque. These results suggest that Ca ions may be concerned with maintaining the integrity of junctional complexes other than tight junctions.

Animals↗

An epidemic of infantile papular acrodermatitis (Gianotti's disease) in Japan associated with hepatitis-B surface antigen subtype ayw.

An epidemic of infantile papular acrodermatitis (I.P.A.) (Gianotti's disease) occurred in Matsuyama City, in south-east Japan in 1974-75. Patients ages ranged from less than one year to eight years. Hepatitis-B surface antigen (HBsAg) was detected by an immune adherence haemagglutination method in the serum samples of 48 of the 54 patients tested. HBsAg subtypes were determined by a haemagglutination-inhibition method. ayw antigens were identified in 42 patients and adr antigens in 3; it was not possible to determine subtypes in the remaining 3 patients because antigen titres were too low. Since subtype ayw and I.P.A. are extremely rare in Japan, the association of the disease with HBsAg subtype ayw is regarded as being most significant.

Acrodermatitis↗

The induction of tumour cell adhesiveness and intercellular junctions by a glycoprotein of rat ascites hepatoma cell surface.

Rat ascites hepatoma AH109A cells (present as a free form in vivo) can aggregate and then develop well-defined tripartite junctional complexes, including intermediate junctions, desmosomes and focal tight junctions, on incubation with a glycoprotein separated from rat ascites hepatoma AH136B cells (forming cell islnds in vivo). The development of binding structures was strongly inhibited by actinomycin D. AH109A cells or rat ascites hepatoma YS cells (present as a free form in vivo) previously treated with the glycoprotein for 24 h, when inoculated i.p., proliferated as free cells in the ascitic fluid, like the untreated cells. AH109A cells actively proliferating in the skin do not form any junctional complexes. The reason for the failure of island formation by AH109A cells or YS cells in vivo is discussed.

Animals↗

An electron microscopic study of tumour cell adhesiveness induced by aggregation promoting factor from rat ascites hepatoma cells.

A substance capable of inducing tumour cell aggregation, which is supposed to be a glycoprotein showing noncytotoxicity, was separated from rat ascites hepatoma cells and partially purified by chromatography. Adhesiveness of rat ascites hepatoma cells induced by this substance was characterized by gradual development of known binding structures during a period of 24 h after contact with the substance; simple apposition and intermediate junctions developed in the early stage, and desmosomes and focal tight junctions in the later stage. It was assumed that the substance might be involved in the development of such binding structures as a triggering mechanism of tumour cell adhesiveness.

Animals↗

Dynamic MR imaging of hepatic adenomas with pathologic correlation.

Two patients with hepatic adenomas (HAs) were evaluated using dynamic magnetic resonance (MR) imaging. Findings of conventional MR imaging of HAs have varied according to reports in the literature, and dynamic MR imaging of HAs has not been previously reported. Dynamic MR imaging using Gd-DTPA showed homogeneous enhancement in the early dynamic phase and prolonged enhancement in the late phase in the typical HA of Case 2. The HA of Case 1 contained fibrosis and exhibited delayed enhancement. The opacification of contrast enhancement was homogeneous and did not occur from the peripheral region as is observed in typical hemangiomas. In addition, washout of contrast material was not as rapid as with typical hepatocellular carcinomas (HCCs).

Adenoma, Liver Cell↗

MR imaging of lingual carcinoma: comparison with surgical staging.

The purpose of this study was to determine the usefulness of magnetic resonance (MR) imaging for the preoperative staging of 18 patients with lingual carcinomas. Tumor stage as determined by MR imaging was compared with pathological stage. Conspicuity of tumors was compared among dynamic MR, T2-weighted, and postcontrast T1-weighted images. The tumor stage was evaluated correctly with MR imaging in 15/18 patients (83.3%). One patient was overstaged and two understaged due to incorrect diagnosis of size. In all T4 cases, tumor extension was diagnosed correctly. Dynamic MR and T2-weighted images were superior to postcontrast T1-weighted images in delineating and showing the extension of carcinomas. However, dynamic MR imaging showed no significant superiority to T2-weighted imaging. We conclude that MR imaging is of great value in the staging of lingual carcinoma. Dynamic study should be performed only when the lesion is undetectable or equivocal on T2-weighted imaging.

Adult↗

Cell proliferation in N-nitrosodiethylamine (DEN)-treated rat liver parenchyma correlated with tumor development.

BACKGROUND/AIMS: The authors wanted to clarify the relationship between the cell proliferation of the liver parenchyma and the development of hepatocellular carcinoma. MATERIALS AND METHODS: Liver specimens of 22 N-nitrosodiethylamine-treated rats and 15 normal control rats were examined using laparotomic biopsies at 30 day intervals, followed by total liver resections after sacrifice. Magnetic resonance imaging was performed to evaluate the development of hepatocellular carcinoma at each period before biopsy. Cell proliferation was determined using the thymidine analogue, bromodeoxyuridine, which is taken up by S-phase cells during DNA synthesis. RESULTS: The cell proliferation of the liver parenchyma gradually increased by the 60th day after the initiation of nitrosodiethylamine administration. The labeling index on the 60th day was 0.33 +/- 0.10%. No abnormal mass lesions were identified in either the control rats or the nitrosodiethylamine-treated-rats within this period. By the 90th day in the nitrosodiethylamine-treated-rats, the labeling index of non-cancerous portion had rapidly increased by as much as 1.60 +/- 0.38%, and magnetic resonance imaging demonstrated small high signal intensity nodules on T1-weighted images. They were either hyperplastic nodules or well-differentiated hepato-cellular carcinomas. Moderately or poorly differentiated hepatocellular carcinomas developed at the 120th day. CONCLUSIONS: The cell proliferation of non-cancerous portion of nitrosodiethylamine-treated-rats livers increased immediately before the development of hepatocellular carcinomas. Detection of this rapid increase of cell proliferation in non-cancerous portions of the liver may suggest a high probability of development of hepatocellular carcinoma in the near future.

Animals↗

Small cell carcinoma of the stomach: a case report.

A case of a gastric small cell carcinoma discovered incidentally by screening ultrasonography is presented. Ultrasonography demonstrated a subcardial metastatic lymph node and multiple hepatic metastatic lesions. Upper GI series and gastroendoscopy revealed a large ulcerated tumor in the cardia of the stomach, and a Borrmann type II tumor, 4 x 2.5 cm, was found in the resected stomach. We describe the radiological findings of the upper GI series, ultrasonography, CT, and gastroendoscopy, and review the literature.

Aged↗