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Biomedical subjects

C Doi

Publications and source records attributed to C Doi.

At least 19 recordsLinked to original sources
PubMed1998

Alteration in immunoexpression of glucose transporter 2 in liver of tumour-bearing rats.

To elucidate interactions between the glucose transport system and hepatic glucose production in the tumour-bearing state, glycogen storage, expression of glucose transporter isoform 2 (Glut 2) and activities of glucose-6-phosphatase (G-6-Pase) and hexokinase were histochemically examined in hepatocytes of tumour-bearing rats. Five male F344 rats, subcutaneously inoculated with methylcholanthrene (MCA)-induced sarcoma cells were compared with five pair-fed animals and four ad libitum fed controls. Glycogen storage was markedly decreased in liver cells of tumour-bearing rats compared to in those of control animals. Glut 2 immunoreactivity was uniformly seen in the cellular membrane of hepatocytes from control animals. In rats bearing sarcoma, the staining intensity was significantly decreased, suggesting that Glut 2 with its bi-directional transport capacity was down-regulated in the tumour-bearing state. Positive staining for hexokinase activity was located in the perivenous area in livers from control animals and was more diffusely located and more intense in livers from tumour-bearing animals. G-6-Pase activity, limited to the peripheral area in livers from controls, extended to the intermediate area and had stronger reactivity in livers from tumour-bearing animals. In the tumour-bearing cachectic condition, glucose may be partially consumed by a futile cycle, hepatic metabolic zonation was disturbed, and the release of glucose from the liver may not be mediated by a facilitative glucose transporter-2.

Animals↗
PubMed1995

Encephalomyocarditis (EMC) virus infection in the common vole, Microtus arvalis.

Encephalomyocarditis (EMC) virus infection in the common vole was examined for the first time. Sixteen 8-week-old males inoculated intraperitoneally with 10(5) plaque-forming units (pfu)/animal of the D variant of EMC virus were killed 3 and 7 days after inoculation (3 and 7 DAI). Viral replication was detected in the brain (10(5) pfu/g), heart (10(4) pfu/g) and pancreas (10(7) pfu/g) of all 8 animals at 3DAI. It was found in the pancreas (10(3) pfu/g) of all 8 animals and in the brain (10(4) pfu/g) of 2 of 8 animals at 7 DAI. Histopathological changes were observed in the brain (mild mononuclear cell infiltration around capillaries and sporadic pyknosis of neurons), heart (minimal myocardial necrosis) and pancreas (prominent acinar cell necrosis with inflammatory exudation) at 3DAI. At 7 DAI, replacement of necrotic tissues by mesenchymal cells and regeneration of acinar cells were conspicuous in the pancreas. Throughout the experimental period, no evidence for diabetogenic effect was found.

Animals↗
PubMed1994

Nicotine improves cognitive disturbance in senescence-accelerated mice.

Senescence-accelerated mice (SAM), a murine model of age-related deterioration in learning ability, were studied as to the acetylcholine (ACh) contents in the brain tissues and the effect of nicotine administration. We found that the ACh content of SAM-P/8 (accelerated senescence-prone) mice was lower than that of SAM-R/1 (accelerated senescence-resistant) mice in the midbrain thalamus and the hypothalamus. In addition, an IP administration of nicotine was found to improve learning ability of SAM-P/8 as shown by performance of a passive avoidance task. Nicotine may potentiate cognitive function in SAM-P/8.

Acetylcholine↗
PubMed1993

Establishment and characterization of carcinosarcoma cell line of the human uterus.

BACKGROUND: The histogenesis of carcinosarcoma is still unknown. METHODS: A new human uterine cell line, EMTOKA, derived from a carcinosarcoma of the uterus, has been passed successfully in cell culture for more than 2 years. The cell line was established on April 11, 1989, in a uterine tumor of a 64-year-old Japanese woman who had a simple hysterectomy. The pathologic examination of the cultured material showed papillary and tubular adenocarcinoma (carcinomatous elements) and spindle-shaped fiber cells and chondrosarcoma (sarcomatous element). RESULTS: The cultured cells showed a cell-to-cell variability and at least five cell types, which included columnar cell, small epithelial cell, moderately sized or large epithelial-like cell, malignant tumor giant cell, and spindle cell types. The EMTOKA cells were transplantable to nude mice and produced tumors that consisted of the same carcinomatous and sarcomatous elements as those observed in the original tumor. The double labeling analysis of vimentin and cytokeratin showed that a large number of cultured cells had positive results for vimentin and a small number of cells had positive results for cytokeratin. Only a very small number of EMTOKA cells stained for vimentin and cytokeratin. The number of cells that expressed neither vimentin nor cytokeratin was very low. CONCLUSIONS: These findings may support the hypothesis that a uterine carcinosarcoma may be derived from a single stem cell that does not express both of the intermediate filaments.

Animals↗
PubMed1993

Transmissibility of the D variant of encephalomyocarditis virus (EMC-D) in mice.

Transmissibility of the D variant of encephalomyocarditis virus (EMC-D) was examined. Eight-week-old ICR:CD-1 male mice inoculated with 10(5) plaque forming units (PFU)/animal of EMC-D intranasally, orally or intraperitoneally showed marked viraemia and prominent pancreatic lesions at 2 days after inoculation (2 DAI), and excreted virus in faeces from 2 to 8 DAI (virus titre: 10(3)-10(5) PFU/g). Only a small proportion of control mice housed with EMC-D-inoculated mice for 10 days developed viraemia and pancreatic lesions.

Animals↗
PubMed1993

Oral administration of peptides derived from bonito bowels decreases blood pressure in spontaneously hypertensive rats by inhibiting angiotensin converting enzyme.

1. Peptides C111 (Gly-Val-Tyr-Pro-His-Lys) and C112 (Ile-Arg-Pro-Val-Gln), extracted from the autolysis product of bonito liver and intestine, have been shown to inhibit angiotensin converting enzyme (ACE) activity in vitro with IC50s of 1.6 microM and 1.4 microM, respectively. We examined the effects of oral administration of these peptides on blood pressure. 2. Oral administration of these peptides (500 mg kg-1 body weight each) inhibited the pressor effect of intravenously administered angiotensin I in Sprague-Dawley rats. 3. In spontaneously hypertensive rats, oral administration of these peptides (100-200 mg kg-1 body weight) showed depressor effects. 4. These results suggest that the peptides, C111 and C112, are orally effective ACE inhibitors with hypotensive effect.

Administration, Oral↗
PubMed1993

Effect of nicotine on cognitive disturbance in animals with acetylcholine deficient brain.

The effect of nicotine on learning disturbance was tested in rats fed with a choline-deficient diet (Ch free) or in senescence-accelerated mice (SAM). Concentration of acetylcholine in the brain was significantly lower in rats fed with Ch free and SAM. Passive avoidance learning shows that rats fed with Ch free and SAM showed significantly impaired learning, compared to controls. Nicotine (0.04 mg/kg) administered intraperitonealy significantly improved learning in animals with learning disturbances, as well as in controls. Vitamin B12 facilitated acetylcholine synthesis or release in the brain and improved the cognitive disturbance. We therefore suggest that acetylcholine contributes to learning and that nicotine may improve learning in an acetylcholine deprived rats.

Acetylcholine↗
PubMed1992

Glomerular lesions in unilateral nephrectomized and diabetic (UN-D) mice.

Experimental diabetes was induced in both control and unilaterally nephrectomized male mice by injecting streptozotocin (SZ) (50 mg/kg x 5 days) one week after nephrectomy. The time course changes in the glomerular lesions were examined for up to 12 weeks after completion of the SZ-injection (12WAI). In unilateral nephrectomized and diabetic mice, mild segmental expansion of the mesangial area developed at 4WAI, and it progressed to prominent segmental glomerulosclerosis at 12WAI. In the electron microscopic examination at 12WAI, marked expansion of the mesangial area, segmental thickening of the glomerular basement membrane, fusion of the foot processes of podocytes and a prominent increase in the number of microvilli of capillary endothelial cells were observed. On the other hand, mild to moderate expansion of the glomerular mesangial area was only sporadically found in unnephrectomized diabetic mice at 12WAI. Interestingly, Bowman's capsules of diabetic mice were generally lined with flattened epithelia but those of non-diabetic mice with cuboidal or low columnar epithelia.

Animals↗
PubMed1992

Prevention of respiratory infections in elderly bed-bound nursing home patients.

A procedure to prevent silent aspiration, which results in frequent respiratory infections, was conducted on elderly bed-bound nursing home patients who suffered mainly from cerebral infarction and dementia. We cleaned the mouth with povidone iodine and kept them in a sitting position for 2 hr after each meal in order to restrict respiratory bacterial infection and to prevent aspiration of gastric juices, respectively. Patients with urinary tract infections were excluded from the present protocol. During the treatment for 103 days the number of febrile days was significantly decreased in the treated group compared with the control group, probably due to minimizing of respiratory infections.

Aged↗
PubMed1992

[Bactericidal clothes protect against respiratory infections in the elderly patients].

In order to protect against infections in the elderly patients, bactericidal clothes were used. Ninety elderly patients were divided into two groups; the control group and the other group with bactericidal clothes. In period I neither group received particular treatment for three months and in period II only the treated group used bactericidal clothes for three months. The control group in period II used regular clothes throughout. Cause of fever (greater than 37 degrees C) extending more than 10 or 15 days were significantly lower in the treated group than in the control group. It was suggested that the bactericidal clothes reduce infections in elderly patients.

Aged↗
PubMed1991

Decreased cerebral glucose metabolism associated with mental deterioration in multi-infarct dementia.

Cerebral glucose metabolism of 18 patients with multi-infarct dementia (MID) and 10 age-matched normal subjects were examined with positron emission tomography and the 18-F-fluoro-deoxy-glucose technique. MID patients had significantly lower glucose metabolism in all the grey matter regions measured and were also characterized by more individuality in metabolic pattern. MID patients were also evaluated as to intelligence quotient (IQ). A positive correlation between IQ as shown by the Tanaka-Binet test and glucose metabolism for the entire grey matter was found. The clinical applicability of this test for predicting cerebral metabolism is discussed.

Aged↗
PubMed1990

Histochemical study on the bile duct system of normal rats.

The bile duct system of normal rats was examined histochemically. Although the apical surface of biliary and glandular epithelial cells was positively stained with Concanavalia ensiformis (Con A), Dolichos biflorus (DBA), Glycine max (SBA), Ulex europeus-I (UEA-I) and Triticumvulgaris (WGA), the cytoplasm did not apparently react with any lectins. Therefore these cells might not play an important role in an active secretion of mucin. On the other hand, the cytoplasm of goblet cells was positively stained with periodic acid-Schiff, high iron diamine, Con A, DBA, Griffonia simplicifolia-II (GS-II), SBA, UEA-I, and WGA. This suggests that mucin secreted from the goblet cells may be acid one with sulfonic terminals.

Animals↗
PubMed1990

Modification of swine serum-induced bile duct lesion in BALB/c mice by cyclophosphamide.

Effects of cyclophosphamide (CY) on the antibody titer level and incidence and severity of swine serum (SS)-induced bile duct lesion (BDL) were examined. BDL induced by 0.2 ml of SS per head twice a week for 2 weeks was characterized by hyperplasia of biliary epithelial cells, proliferation of mucous glands, and periductal infiltration of eosinophils with mild fibrosis. CY showed no significant influence on the above-mentioned parameters at the dose levels of 140 and 210 mg/kg. On the other hand, CY lowered the antibody titer level and decreased the severity of BDL at the dose level of 280 mg/kg, and it suppressed the antibody response and BDL at the dose level of 280 x 2 mg/kg. Thus the antibody titer level and the severity of BDL were closely related each other.

Animals↗