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Biomedical subjects

R Saitoh

Publications and source records attributed to R Saitoh.

At least 37 records · Page 2Linked to original sources
PubMed1991

[A case of spindle cell (squamous) carcinoma (WHO) of the lung].

A 76-year-old man with spindle cell (squamous) carcinoma of the lung developed fatal respiratory failure after limited thoracic irradiation at a total dose of 18 Gy. He developed severe pulmonary toxicity, which presented as dry cough, dyspnea, and pulmonary infiltrates extending beyond the radiation field. Microscopically, a transitional form of squamous to spindle-shaped cells was observed in the primary tumor, located at right S8. Immunohistochemical examination showed positive staining of spindle cells for keratin, vimentin, and EMA, but not for desmin. These results indicate that the spindle cells had characteristics of squamous epithelial cells, and differed from carcinosarcoma. Distant metastatic lesions were composed of only the spindle cell component.

Aged↗
PubMed1990

Modulation of c-myc expression by transforming growth factor beta 1 in human hepatoma cell lines.

The effects of transforming growth factor beta 1 (TGF-beta 1) on cell proliferation of human hepatoma cell lines, PLC/PRF/5 and Mahlavu, were investigated under serum-free conditions. DNA synthesis was strongly inhibited in the PLC/PRF/5 cells by addition of TGF-beta 1 (0.5 to 4.0 ng/ml), but remained unchanged in the Mahlavu cells. Also the expression of c-myc mRNA was suppressed by the addition of TGF-beta 1 in the PLC/PRF/5 cells but not in the Mahlavu cells. These results indicate that TGF-beta 1 might regulate cell growth, in part, by modulating c-myc expression, although there is no direct proof that c-myc expression is really relevant to DNA synthesis mediated by TGF-beta 1.

Carcinoma, Hepatocellular↗
PubMed1989

[Lung transplantation as a treatment method in terminal respiratory failure].

Lung transplantation is the last treatment for terminal respiratory failure due to irreversible pulmonary disease such as fibrosis and emphysema. In this paper we reported the results of our studies on three major problems for conducting clinical lung transplantation sefely, including lung preservation, early diagnosis of lung allograft rejection and bronchial anastomotic healing. We have developed a method for 48- and 96-hour lung preservation. Under simple hypothermic preservation using phosphate buffered solution resembling extracellular fluid, 48-hour storage of the lung becomes possible. Immunologic monitoring is feasible for early detection of postoperative rejection of the lung transplant. In this study subset and spontaneous blastogenesis of lymphocyte obtained from bronchoalveolar lavage fluid were measured in orthotopic rat lung allotransplantation. Lung allograft rejection is closely connected with wound healing of the bronchial anastomosis in lung transplantation. It seems that clinical applications of single and double lung transplantation is now possible for patients with terminal respiratory disease in our country.

Bronchoalveolar Lavage Fluid↗
PubMed1988

The inhibitory effect of forskolin on antibody-dependent cell-mediated cytotoxicity using Chang liver cells as target cells.

The effect of forskolin, a unique adenylate cyclase activator, on antibody-dependent cell-mediated cytotoxicity (ADCC) was examined. ADCC was assayed using Chang liver cells as the target cells, immuned rabbit serum as the antibody and healthy human peripheral blood mononuclear cells (PBMNC) as the effector cells. Forskolin at concentrations ranging from 1 to 20 microM significantly inhibited ADCC in a dose-dependent manner. By the addition of forskolin, cyclic AMP levels did not change in Chang liver cells but increased in PBMNC. Therefore, it appears that forskolin exerted an inhibitory effect on ADCC by increasing the intracellular cyclic AMP levels in PBMNC, the effector cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1988

Changes in hepatic functional reserve after transcatheter embolization of hepatocellular carcinoma. Assessment by maximal removal rate of indocyanine green.

To clarify the influence of transcatheter arterial embolization (TAE) on hepatic function, the maximal removal rate of indocyanine green (ICG-Rmax), which represents the hepatic functional reserve, and the plasma disappearance rate of indocyanine green (k-ICG) were measured serially before and after 15 TAE procedures performed on 13 hepatocellular carcinoma (HCC) patients with underlying hepatic diseases. Compared to the values before TAE, ICG-Rmax values did not change or gradually decreased during 4 weeks in seven of the 13 patients but markedly decreased in the remaining six by as much as 50% during the first week. k-ICG values remained almost unchanged at any time after TAE. Albumin and prothrombin time were serially measured before and after 24 TAE procedures performed on 21 HCC patients with underlying hepatic diseases in whom no plasma products had been used for therapy. Albumin decreased by up to 75% in one of the 21 patients during the first week but did not change or gradually decreased in 20 of the 21 patients. Prothrombin time showed no obvious changes. This study showed that prominent changes occurred in ICG-Rmax, i.e., in the hepatic functional reserve, after TAE.

Aged↗
PubMed1987

Hepatic conversion of 1-(tetrahydro-2-furanyl)-5-fluorouracil into 5-fluorouracil in patients with hepatocellular carcinoma.

The pharmacokinetics of 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) and its conversion into 5-fluorouracil (FUra) in liver tissue were studied in ten patients with hepatocellular carcinoma (HCC). The plasma concentration of FT after its intravenous injection (dosage: 800 mg) was computerfitted to a bi-exponential function (C = Ae-alpha t + Be-beta t), indicating a two-compartment disposition. The pharmacokinetic parameters did not significantly differ between the five patients with, and the five without cirrhosis of the liver. The plasma concentrations of FUra likewise showed no significant difference between the two groups. The rates of FT degradation in the liver tissue homogenate were similar for four of the patients with cirrhosis (0.10 +/- 0.05 mumol/g liver protein/30 min) and four of those without it (0.13 +/- 0.05). The rates of cytochrome P-450-dependent FUra formation in the microsomal fraction of liver tissue from two patients (1.1 and 1.3 nmol/mg microsomal protein/30 min) were dramatically reduced to less than half of those of two control subjects (2.4 and 2.7). The estimated rates of FUra formation in the soluble fraction (105,000 X g supernatant fraction) from the two patients (0.1 and 0.13 nmol/mg protein/30 min) were almost identical to those from the controls (0.12 and 0.14), suggesting that the rate in the soluble fraction from HCC patients may not be as strongly affected as the rate in the microsomal fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Elevated antibody-dependent cell-mediated cytotoxicity and its inhibition by nicotinamide in the diabetic NOD mouse.

Antibody-dependent cell-mediated cytotoxicity (ADCC) by splenic mononuclear cells was measured in female non-obese diabetic (NOD) mice and age-matched ICR mice. No significant difference in ADCC activities was observed between the two groups when all the NOD mice were pre-diabetic. ADCC activities in diabetic NOD mice were significantly higher than those in age-matched ICR mice (P less than 0.001). Nicotinamide, known to prevent the diabetes of the NOD mouse, strongly inhibited ADCC by the mononuclear cells from diabetic NOD mice. Kinetic studies revealed that the inhibition was non-competitive.

Animals↗
PubMed1984

Different effects of D-glucose anomers on enhanced secretion of gastric acid in rat.

The injection of alpha-, beta-, or equilibrated (alpha: 36%, beta: 64%) D-glucose solution into the cranial side of the carotid artery decreased gastric acid output caused by insulin in rats with bilateral adrenalectomy. This effect was not reproduced after vagotomy at the cervical level. Of the 3 forms of D-glucose solution the effect of beta-D-glucose was greatest. The injection of isotonic NaCl solution, however, produced no change in acid output. These results suggest that blood beta-D-glucose may play a predominant role in activating a brain mechanism which controls gastric acid secretion via the vagus nerve.

Adrenalectomy↗
PubMed1984

Effect of high doses of synthetic estrogen on lipid metabolism in castrated male rats.

The mechanism by which high doses of estrogen influences lipid metabolism was studied with a microtubular blocking agent. Castrated male rats received oral injection daily for 14 days of 3 mg hexestrol in olive oil, or oil alone as controls. About half of the animals in each group were injected intraperitoneally with 4 mg/100 g body weight colchicine 3 hr before they were killed. Hexestrol treatment caused an accumulation of esterified cholesterol in the liver while it decreased those in serum. Triglyceride concentrations slightly decreased in the liver but were unaffected in serum. On polyacrylamide-gel disc electrophoresis, the peaks of high density lipoproteins (HDL) and low density lipoproteins (LDL) were decreased remarkably. Electron microscopic examination of hepatocytes revealed electron-lucent lipid droplets in the cytoplasm. After a colchicine treatment of the control animals, concentrations of esterified cholesterol and triglycerides markedly increased in the liver, while those in serum decreased. Electron microscopic examination of hepatocytes revealed numerous secretory vesicles filled with nascent VLDL. In hexestrol-treated animals, the colchicine treatment was associated with marked decreases in serum-esterified cholesterol and triglyceride as seen in the controls. However, there were no further increases of esterified cholesterol in the liver, and the increase of triglycerides was slight. Electron microscopic examination showed less secretory droplets than in the controls. These data suggest that very low density lipoproteins (VLDL) synthesis in the liver of hexestrol treated rats was inhibited. An accumulation of esterified cholesterol with a marked decrease in serum could not be accounted for by the inhibition of lipoproteins secretion, but rather by their enhanced entry into the liver.

Animals↗
PubMed1984

CT findings of atrial myxoma.

The computed tomographic (CT) appearance of six atrial myxomas was analyzed. Five of the myxomas were located in the left atrium and one was in the right atrium. The margin of the myxoma was at least slightly lobulated in five cases and the content was inhomogeneous in all. Calcification was demonstrated in three cases. The site of attachment of the myxoma was demonstrated by CT to be the atrial septum in all cases. The CT findings correlated well with the operative findings. CT revealed prolapse of the myxoma into the ventricle in two cases. This finding was similar to echocardiographic and cineangiographic findings. It is concluded that it is possible with CT to diagnose atrial myxoma by the location and nature of the intracardiac mass and to differentiate it from thrombus.

Adult↗