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Biomedical subjects

M Akagi

Publications and source records attributed to M Akagi.

At least 217 records · Page 12Linked to original sources
PubMed1983

Changes of alveolar stability and phospholipids in pulmonary surfactant in acute pancreatitis.

We investigated changes of alveolar stability and phospholipids in the pulmonary surfactant in case of acute pancreatitis induced in rats. Alveolar stability was examined by recording the pressure-volume relationship. The lung volumes during deflation decreased significantly at equivalent transpulmonary pressures, particularly when the pressure was lower than 6 cm H2O. Bubble stability ratio and surface tension indicated that the surface activity of the pulmonary surfactant did decrease in the rats with acute pancreatitis. The alveolar phospholipid content decreased, and the lecithin fraction also decreased significantly, as compared to the control groups. The metabolism of alveolar lecithin was examined following intravenous administration of 14C-labeled palmitate. The biological half-life of the radioactivity of alveolar lecithin was approximately 6 hours in the pancreatitis group, 12 hours in the hepatic ducts ligated group and 14 hours in the simple laparotomy group. The degradation of alveolar lecithin, as well as its synthesis, was accelerated in the rats with acute pancreatitis. However, a decrease in alveolar phospholipid, mainly in lecithin fraction, indicated that the synthesis was inadequate to maintain normal levels and the impairment in pulmonary surfactant may result in a respiratory insufficiency.

Acute Disease↗
PubMed1983

Studies of the mechanisms of gastric bleeding under obstructive jaundice. Role of biogenic amines.

Mechanisms of gastric bleeding under obstructive jaundice were studied in adult male Wistar rats. Following ligation of the common bile duct, mucosal noradrenaline significantly decreased in both the pyloric and fundic gland areas of the gastric mucosa by 20 days after the operation. Serotonin increased only in the pyloric gland area, and histamine increased in the fundic gland area. Urinary excretion of free noradrenaline significantly increased after the ligation. Three weeks after the ligation, restraint and water immersion experiments were conducted. Under water immersion, gastric blood flow significantly reduced in rats with obstructive jaundice compared to controls. Acid output decreased in both groups. Gastric bleeding was noted in the fundic gland area significantly earlier in the ligated rats than in the non-ligated rats. Administration of noradrenaline s.c. 30 minutes before immersion significantly blocked the reduction in gastric blood flow and protected the gastric mucosa against acute bleeding under immersion. These results suggested that prolonged obstructive jaundice may deplete noradrenaline in the gastric mucosa, and that gastric mucosal ischemia caused by this sympathetic dysfunction plays an important role in the formation of acute gastric bleeding under obstructive jaundice.

Animals↗
PubMed1983

Mechanisms of fat malassimilation following total gastrectomy in rats.

The present study is designed to elucidate the mechanisms of fat malassimilation following total gastrectomy. Using male Wistar rats, total gastrectomy with an esophagoduodenostomy was performed. Totally gastrectomized and normal control rats, provided with intestinal lymph fistula or closed intestinal loops with intact blood supply, were used for the absorption studies. The lymphatic absorption of the emulsion in the totally gastrectomized rats, administered into the duodenum, was significantly less than that in the control, administered into the stomach or duodenum. Fat assimilation in the totally gastrectomized rats was obviously disturbed. In the totally gastrectomized rats, the lymphatic absorption of the micelle was significantly higher than that of the emulsion. An examination of the lipid absorption in the closed intestinal loops, injected micellar solution, showed no differences between the control and totally gastrectomized rats in the lumen or wall recovery, while, the total esterified lipids in the intestinal mucosa from the ligament of Treitz to the cecum of the totally gastrectomized rats were significantly less than those of the control. These results suggest that postgastrectomy fat malassimilation is due to both an impaired micellar formation and the disturbed resynthesis of triglyceride from absorbed fatty acid and monoglyceride.

Animals↗
PubMed1983

Electron microscopic observation of gastric mucosal capillaries in diabetics--relationship between diabetic microangiopathy and complications following gastrectomy.

An electron microscopic study was made of the gastric mucosal capillaries (GMC) of diabetic patients. Ultrastructural findings, including diabetic microangiopathy (DMA), and clinical features of these diabetic patients were investigated in relation to anastomotic leakage after gastrectomy. The gastric mucosa of resected stomachs from 12 diabetics and 10 nondiabetics were examined. Ultrastructurally, DMA was demonstrated in the stomachs of diabetics, in which the basement membrane of GMC was thicker. The degree of this DMA in the stomach significantly correlated with the duration of diabetes and the degree of DMA found in the skin, but not with age and fasting plasma glucose (FPG) level. Marked DMA was observed with significant frequency in diabetics with anastomotic leakage after gastrectomy. In our hospital, anastomotic leakage after gastrectomy occurred in 9 out of 53 diabetics. Diabetics with anastomotic leakage had severe FPG, a long duration of diabetes and diabetic retinopathy. It seems reasonable to presume that anastomotic leakage after gastrectomy occurs more frequently in diabetics with ultrastructurally severe DMA, clinically severe FPG and relatively long duration of diabetes.

Adult↗
PubMed1983

[Biological and clinical analysis of breast cancer in relation to hormone receptors].

We examined whether or not the presence of hormone receptors (ERC, PRC, and ERN) were related to morphological and functional features in breast cancers. Well-differentiated tumors were more frequently receptor positive while poorly differentiated tumors were generally receptor negative. And labelling index and receptor contents were negatively correlated. There was a significant inverse correlation between the receptor contents and numbers of intracellular organellas in ultrastructural features of breast cancer cells. In LMI tests by 3-M KCl cancer extracts, migration of leucocyte from patients with poorly differentiated tumors were more frequently inhibited than those well differentiated tumors. Patients with receptor positive tumors were more endocrine sensitive and had better prognosis.

Breast Neoplasms↗
PubMed1982

Effects of glucagon on myoelectrical activity of the stomach of conscious and anesthetized dogs.

Effects of glucagon on gastric electrical and mechanical activities recorded by means of a chronically implanted suction electrode and a force strain gauge transducer were examined in conscious and anesthetized dogs. Glucagon (1-10 micrograms/kg) induced inhibition of gastric electrical activity together with mechanical activity in conscious dogs. The plasma glucagon level following exogenous glucagon administration which induced the inhibitory effects on electrical and mechanical activities was over 5 ng/ml. alpha- and beta-adrenoceptor blocking agents did not significantly alter the inhibitory effect of glucagon. Changes in plasma concentrations of glucose, cAMP, insulin, gastrin and catecholamines after glucagon administration were not correlated with the inhibitory action of glucagon on the gastric electrical and mechanical activities. Glucagon at higher concentrations (10(-6) -5 x 10(-6) g/ml) did not produce appreciable changes in motility of the canine gastric strips in vitro. In an anesthetized condition, the inhibitory action of glucagon was completely abolished. Results indicate that exogenously applied glucagon possibly acts directly on the central nervous system, and thus resulted in the inhibition of the gastric electrical and mechanical activities.

Action Potentials↗
PubMed1982

Relationship between the content of estrogen and progesterone receptors and the pathological characteristics in human breast cancer.

Assays of estrogen receptors (ER) and progesterone receptors (PgR) were performed by using the dextran-coated charcoal (DCC) method in 124 cases of invasive breast cancer. The results were correlated with clinical and pathological characteristics. There was no correlation between steroid hormone receptor contents and menopausal status, size of tumor, axillary lymph node status, or histological type. The presences of ER and PgR were significantly correlated with histological grade and its mitotic component. 78.3% of well-differentiated (Grade I) tumors were ER positive. Of this number, 61.1% were also PgR positive. In contrast, 69.0% of poorly differentiated (Grade III) tumors were ER and PgR negative. Tumors with a prominent lymphoid infiltration demonstrated a low frequency of positive ER and PgR. There was a significant inverse correlation between the degree of lymphoid infiltration and histological grade. These results suggest that the ER and PgR status of tumors may indicate a malignancy, and prognostic information can thus be obtained independently of other known factors such as size of the tumor and axillary lymph node status.

Adenocarcinoma↗
PubMed1982

Measurement of nuclear estrogen receptors by charcoal adsorption: relationships of cytoplasmic and nuclear estrogen receptors and progesterone receptors in human breast cancer.

Nuclear estrogen receptors (ERN) were measured in human breast cancer and 7,12-dimethylbenz[a]anthracene-induced mammary carcinoma using the dextran-coated charcoal method without addition of an adsorbing material such as hydroxyapatite. Cytoplasmic estrogen receptors (ERC), cytoplasmic progesterone receptors (PgR), and ERN were measured in 111 primary and 11 locally recurrent breast cancers. ERC were found in 52%, PgR in 35%, and ERN in 40%. ERN and PgR were more frequent in tumors with a higher level of ERC. PgR were more frequent in ERN-positive tumors, and ERN were more frequent in PgR-positive tumors. The addition of an ERN assay to both ERC and PgR assay may be more informative for prediction of estrogen dependency than the mere determination of the existence of receptors in the cytoplasm.

Adsorption↗
PubMed1981

beta-Galactosidase-neuraminidase deficiency in adults: deficiency of a freeze-labile neuraminidase in leukocytes and fibroblasts.

4-methylumbelliferyl neuraminidase activity was studied in fibroblasts, leukocytes, and frozen tissues from adult patients with beta-galactosidase-neuraminidase deficiency and specific clinical manifestations. This enzyme was almost completely deficient in fibroblasts, but the residual activity was relatively high (20% of the control mean) in the leukocytes from the patients. The frozen liver from one patient showed the enzyme activity as high as controls. This enzyme consisted of two components, freeze-labile and freeze-stable, and it was demonstrated that only the labile enzyme was deficient in fibroblasts and leukocytes. The apparently normal activity of neuraminidase in frozen autopsy tissues of a patient may be explained by the loss of the labile component in control tissues after a long-term freezing. The neuraminidase activity was variable in parents and no definite conclusion was drawn on the hereditary nature of the disease.

Brain↗
PubMed1981

Studies on alkaline phosphatase isoenzyme in gastric carcinoma tissues.

An analysis of the alkaline phosphatase (ALP) isoenzyme in 75 gastric carcinoma tissues was performed. The properties and the originating cells of ALP isoenzymes in them were clarified by using both enzyme histochemical and biochemical methods which had respective superiorities. Also the relationship between intestinal metaplasia and gastric carcinoma was discussed. Liver, placental and small intestinal type ALPs were found in the carcinoma tissues. No ALP activity was found in the carcinoma cells except in the stromal cells in 46 out of 75 cases. In all of these cases, only liver type ALP was found. While, in 29 cases, the activity was also found in carcinoma cells. In these cases, placental and small intestinal type ALPs were found in addition to liver type ALP in 26 and 3 cases, respectively These results indicated that liver type ALP came from the stromal cells and placental and small intestinal type ALPs came from carcinoma cells. The ALP found in carcinoma cells was placental (Nagao isoenzyme) type in most cases. While, the ALP in intestinal metaplastic epithelial cells was small intestinal type in all cases. No sufficient evidence indicating the relationship between intestinal metaplasia and gastric carcinoma was obtained in respect of ALP isoenzyme.

Alkaline Phosphatase↗