Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

1,445 records · Page 81Linked to original sources

PubMedDate not supplied

Induction of malignant fibrous histiocytoma in female Fisher rats by implantation of cyanoacrylate, zirconia, polyvinyl chloride or silicone.

Five kinds of foreign bodies (silicone, cellulose, polyvinyl chloride, zirconia and alkyl-alpha cyanoacrylate) were implanted into subcutaneous tissue of female Fisher rats. Subcutaneous tumors were induced in 27.3, 54.5, 100, 63.6% of rats by silicone rubber, polyvinyl chloride, zirconia and alkyl-alpha-cyanoacrylate, respectively, but not by cellulose. Almost all tumors were composed of a mixture of cells that resembled fibroblasts characterized by the presence of numerous rough-surfaced endoplasmic reticulum and Golgi apparatus, histiocytes characterized by developed endoplasmic reticulum and abundant lysosome, myofibroblasts characterized by the presence of both myofibrils and fibroblast-like structures, and immature mesenchymal cells. In some tumors, the cells exhibited a storiform pattern. Some tumor cells were positively stained by ED2 or anti-muscle actin antibody. The features of induced tumors in rats were consistent with those of human malignant fibrous histiocytoma. A rat malignant fibrous histiocytoma transplanted into the subcutaneous tissue of the syngeneic female Fisher rats grew and metastasized to the lungs.

Animals↗

PubMedDate not supplied

Primary hepatic neuroendocrine carcinoma with multiple metastases: a case report.

We report a rare case of primary hepatic neuroendocrine cell carcinoma with multiple metastases to the liver, lung, diaphragm, bone, and pancreas. The patient was a 45-year-old man with jaundice and a large hepatic tumor measuring 12 x 16 cm at autopsy. Located in the right lobe, it was hyperechoic and inhomogeneous on US, a diffusely low density mass that contained capsule- and septum-like structures enhanced by contrast medium on CT, an inhomogeneously low intensity mass with much lower intensity foci on T1-weighted MRI, and a diffusely high intensity mass containing small higher and lower intensity foci on T2-weighted MRI. These findings are similar to those of a few previously reported cases, but are not specific to this tumor.

Carcinoma, Neuroendocrine↗

PubMedDate not supplied

Establishment of a daunorubicin-resistant cell line which shows multi-drug resistance by multifactorial mechanisms.

We established a daunorubicin (DNR)-resistant cell line derived from human leukemia cell line K562, (K562/D1-9), which also shows multidrug resistance (MDR). K562 cells were cultured with serially increasing concentrations up to 1.0 microM of DNR and then cloned by the limiting dilution method. K562/D1-9 cells were found to be 28 times more resistant to DNR than their its parent cells. Intracellular accumulation of DNR in K562/D1-9 was less than in the wild type, and P-glycoprotein (PGP) was overexpressed. Both DNR resistance and its intracellular accumulation were partially reversed by addition of verapamil to K562/D1-9 cells, but not to K562 cells. Topoisomerase II (Topo II) activity was decreased in K562/D1-9 cells. In contrast to other drugs, such as doxorubicin and vincristine, verapamil could not reverse drug resistance to VP-16 in the K562/D1-9 cell line, suggesting the importance of Topo II as the target of MDR. Protein kinase C (PKC) level was higher in K562/D1-9 than in K562. These findings suggested that the mechanism of MDR in this cell line might be multifactorial, including PGP, topo II and PKC. The K562/D1-9 cell line may be a good model for studying drug resistance in leukemia chemotherapy.

Antibiotics, Antineoplastic↗

PubMedDate not supplied

Predictive factors for efficacy of interferon therapy in chronic hepatitis type C.

BACKGROUND/AIMS: It has recently become possible to quantify HCV-RNA in serum and to analyze the HCV-RNA genotype. In this study, we investigated the relationship among the response to interferon therapy, the HCV-RNA concentration, genotype and histological findings of the liver. PATIENTS AND METHODS: Sixty-three patients with chronic hepatitis type C received interferon alfa therapy for 24 weeks. The HCV-RNA concentration in serum was measured semiquantitatively with reverse transcript semi-nested polymerase chain reaction and classified as negative to +3. HCV-RNA genotype was analyzed using a mixture of four type specific primers. RESULTS: HCV-RNA concentration was significantly higher in patients with genotype II and CAH2B than genotype III, CPH and CAH2A (p < 0.05). At 24 weeks after the end of interferon therapy, HCV-RNA in serum disappeared in 24 of 63 patients (38%). Strong resistance to the therapy was noted in patients with both genotype II and a high concentration of HCV-RNA in serum (the efficacy was only 7%). Therapy efficacy decreased with the severity of liver histological findings, reaching only 20% in those with CAH2B. CONCLUSION: Both the concentration and genotype of HCV-RNA seem to be important factors in determining the efficacy of interferon therapy.

Adult↗

PubMedDate not supplied

Molecular analysis of a case of Philadelphia chromosome-positive acute myeloid leukemia.

This report describes a precise molecular analysis of a rare case of Philadelphia chromosome (Ph) positive acute myeloid leukemia (AML) (FAB classification M2). Phenotypic markers were positive for cells of the myeloid lineage, but negative for B cell and T cell lineage. The leukemic cells carried a Philadelphia chromosome. Major breakpoint cluster region (M-BCR) rearrangement was detected by the Southern blot analysis. Reverse transcriptase polymerase chain reaction analysis revealed the presence of b3a2 BCR/ABL mRNA transcripts. The patient achieved complete remission by conventional remission induction therapy for acute myeloid leukemia. M-BCR rearrangement could not be detected during complete remission. After hematological remission of an 8-month duration, the patient relapsed and died of respiratory distress due to pneumonia. Our case indicate Ph-positive AML with M-BCR rearrangement actually exists. Ph-positive AML carries either M-BCR rearrangement expressing the P210 BCR-ABL or minor breakpoint cluster region (m-BCR) rearrangement producing the P190 BCR-ABL. Therefore, additional other factor (s) apart from the Ph chromosome must be responsible for the acute malignant transformation.

Aged↗