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Biomedical subjects

M Iwai

Publications and source records attributed to M Iwai.

266 records · Page 15Linked to original sources
PubMedDate not supplied

Micronucleus test with cyclophosphamide using mouse peripheral blood reticulocytes.

The usefulness of the micronucleus test using supravital staining of peripheral blood reticulocytes with acridine orange was evaluated in two laboratories after administering cyclophosphamide (CYP) as a model chemical by intraperitoneal injection (i.p.) to CD-1 mice. The frequencies of micronucleated peripheral reticulocytes (MNRETs) increased dose-dependently at each sampling time. There were no significant differences in the results obtained with this new method by the two laboratories. Although the induction of MNRETs was delayed by about 24 h compared to that of micronucleated polychromatic erythrocytes (MNPCEs) in the bone marrow, the frequencies of MNRETs and MNPCEs were almost identical at each optical sampling time, 24 h for MNPCEs and 48 h for MNRETs. Therefore, it is concluded that this method is a suitable alternative to that using femoral marrow cells.

Animals↗
PubMedDate not supplied

Long-term effects of bezafibrate on in vivo VLDL-triglyceride production in the rat.

Long-term effects of bezafibrate on in vivo production of VLDL-triglyceride were studied in the rat. Bezafibrate given at a daily dose of 30 mg/kg body weight for 14 days produced a decrease not only in triglyceride by 51% but in cholesterol by 28% and phospholipid by 18%. Despite a marked reduction in plasma triglyceride concentrations, there was no significant change in the rate of VLDL-triglyceride secretion from the liver into the circulation between bezafibrate-treated and control animals (1113 +/- 58 and 1234 +/- 63 micrograms/min, respectively). In addition, bezafibrate produced no change in lipid composition in VLDL. These results suggest that bezafibrate enhances triglyceride removal from the circulation, which leads to reduction in plasma triglyceride.

Animals↗
PubMedDate not supplied

Iatrogenic superior mesenteric arteriovenous fistula: ultrasonographic, CT and angiographic features and histological findings of the liver biopsy.

Iatrogenic superior mesenteric arteriovenous fistula is rare. We treated a patient with this problem 6 years after small bowel resection for intestinal obstruction. The symptoms and signs were those of intestinal ischaemia and portal hypertension with an abdominal bruit. Ultrasonography and enhanced computerized tomography of the abdomen suggested the presence of superior mesenteric arteriovenous fistula, with a dilated portal vein and a communication between the dilated superior mesenteric vein and its artery. The exact location of the fistula was then determined by selective superior mesenteric arteriography. The fistula was ligated in an emergency operation to prevent cardiac or renal failure and to relieve portal hypertension. Liver biopsy showed no cirrhotic changes, but fibrosis was seen around the portal veins. We describe here not only the diagnostic arteriographic findings of superior mesenteric arteriovenous fistula, but also the interesting and suggestive ultrasonographic and computed tomographic findings. Early correction of such fistulas is recommended to prevent cardiac or liver failure.

Adult↗
PubMedDate not supplied

Effects of colchicine on the synthesis and transport of albumin: a combined electron cytochemical and autoradiographic study.

We investigated the intracellular transport of albumin in the livers of rats treated with colchicine using immunoperoxidase study as well as combined immunoelectron microscopy and autoradiography with [3H]-leucine. Immunoreaction of albumin was observed in all hepatocytes. Its subcellular location was in the rough endoplasmic reticulum, Golgi apparatus and lysosomes. After the injection of [3H]-leucine through the portal vein, a combined technique revealed accumulated grains on the albumin-positive Golgi apparatus or the albumin-positive vesicles in the vicinity of the Golgi apparatus. These findings suggest that albumin transport from the Golgi apparatus to sinusoids is disturbed by colchicine. Enzyme histochemistry showed many acid phosphatase-positive lysosomes in hepatocytes of the liver treated with colchicine. Albumin retained in the vicinity of the Golgi apparatus may be digested by lysosomes. An in situ hybridization study with isotopes revealed the presence of silver grains for albumin mRNA in all hepatocytes of livers treated or untreated with colchicine; there was no significant difference in the number of silver grains in the two groups. Therefore, colchicine has very little effect on albumin synthesis in the liver.

Albumins↗
PubMedDate not supplied

Langerhans cell histiocytosis of an adult with tumors in liver and spleen.

We describe a 58-year-old male with multiple histiocytic tumors in the liver and spleen. Multiple tumors in the liver and spleen were seen by image analysis, and splenectomy showed a large splenic tumor with a small nodule and a swelling lymph node in the hilus. Histological features of the tumors in the liver and spleen revealed proliferation of histiocytic cells with large and clear cytoplasm and a horseshoe-shaped nucleus. Immunohistochemical studies revealed the presence of S-100 protein and CD1a antigen in the tumor cells, and neither lymphocytic marker nor lysozyme was detected. No definite Birbeck granules were seen ultrastructurally, thus the tumor cells could be classified into Langerhans cell type without Birbeck granules. Administration of adriamycin, vincristine, cyclophosphamide and prednisolone reduced size and number of the liver tumors, and the histiocytic cells could not be detected in repeatedly biopsied tissue from liver tumor. We present the clinical, immunohistological and cytological features in a visceral type of adult Langerhans cell histiocytosis, which responded well to chemotherapy.

Antigens, CD1↗
PubMedDate not supplied

Suppression by a pine cone extract of Pinus parviflora Sieb et Zucc of mammary tumour virus in milk of mice.

The intravenous or the oral administration of a pine cone extract of Pinus parviflora Sieb et Zucc (Fr VI) and the related synthetic agent (DHP-FA) to lactating SHN mice prevented an increase of milk levels of mouse mammary tumour virus (MMTV) from day 7 to day 14 of lactation. Furthermore, Fr VI decreased the MMTV level at the 2nd lactation compared to the 1st lactation. This is the first report on the inhibition of milk MMTV of mice in the in vivo system.

Administration, Oral↗
PubMedDate not supplied

Cytologic detection of malignant lymphoma cells with a hairy appearance in ascitic fluid. Report of a case with immunofluorocytometric analysis.

Neoplastic lymphocytes with a hairy appearance were detected in the ascitic fluid from a case of retroperitoneal malignant lymphoma. Although the tumor cells resembled those of hairy-cell leukemia (HCL), no leukemic change was observed, and the anatomic location of the neoplastic cells was different from that seen in HCL. The tumor cells were positive for some immunohistochemical markers of HCL (i.e., CD1 9 and SIg) but were negative for others (CD11c, CD25 and tartrate-resistant acid phosphatase). Immunocytofluorometric and postmortem histologic studies showed the lesion to be a well-differentiated B-cell lymphocytic lymphoma with plasmocytic differentiation in some cells.

Aged↗
PubMedDate not supplied

The combination of different types of antitumor topoisomerase II inhibitors, ICRF-193 and VP-16, has synergistic and antagonistic effects on cell survival, depending on treatment schedule.

VP-16 and ICRF-193 are different types of antitumor topoisomerase II inhibitors, being cleavable and non-cleavable complex-stabilizing types, respectively. To examine the possibility of enhancing the efficacy of combination chemotherapy, we carried out simultaneous and sequencial treatment of cells with the two drugs. When KB cells were exposed continually to low concentrations (0.05 - 0.2 microM) of the drugs, the effects were synergistic. In contrast, when the cells were treated with high concentrations of ICRF-193 and VP-16 for 1 hour, the VP-16-induced cytotoxicity was prevented by ICRF-193 and the degree of prevention was increased by the pretreatment of cells with ICRF-193, while post-treatment with ICRF-193 had little effect on the cytotoxicity of VP-16. ICRF-193 at 1 microM was found to interact with about half molecules of topisomerase IIa and II beta in cells, as judged by increased amounts of a salt-stable complex. ICRF-193 inhibited in vitro VP-16-induced cleavable complex formation, but a much higher concentration was needed to reverse the cleavage already generated by VP-16. Thus, the antagonistic or synergistic effects of ICRF-193 and VP-16 depend on the concentration of the drug, as it may be critical as to how many molecules of cellular topoisomerase II interact with the drugs.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Clinical features, image analysis, and laparoscopic and histological liver findings in Budd-Chiari syndrome.

BACKGROUND/AIMS: Clinical manifestations and histological features of the liver in Budd-Chiari syndrome (BCS), with or without idiopathic membranous obstruction of the inferior vena cava (MOVC), vary according to whether BCS is acute, subacute or chronic. We clarified the diagnostic features in 6 patients with MOVC and in 1 without MOVC. METHODOLOGY: Five patients with subacute or chronic type BCS with MOVC complaining of epigastric pain, hematemesis and encephalopathy, and signs of portal hypertension or collateral circulation were seen. There was 1 asymptomatic patient with MOVC. One patient with acute type BCS without MOVC revealed hepatic and multi-organ failure. Liver function tests in BCS with MOVC were similar to those in liver cirrhosis, and laboratory data in acute type without MOVC were quite the same as those seen in fulminant hepatitis. Non-invasive image analysis by US, CT and MRI showed thrombi and obstruction of the IVC, and extrahepatic vasculature or communication between hepatic veins and IVC. Vena cavography showed the length of obstruction in IVC and collateral circulation in the extrahepatic or intrahepatic veins. Liver biopsy demonstrated massive hemorrhagic necrosis in acute type without MOVC, and laparoscopy with liver biopsy in asymptomatic, subacute and chronic type with MOVC showed subcapsular hemorrhage, congestion, fibrosis, and cirrhotic features. CONCLUSIONS: The non-invasive image analysis was complementary to vena cavography, and liver biopsy with or without laparoscopy was essential not only for diagnosis of acute, subacute, and chronic BCS, but also for therapeutic decision-making.

Adult↗