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C Doi

Publications and source records attributed to C Doi.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1989

Susceptibility of four species of small rodents to encephalomyocarditis (EMC) virus infection.

The D variant of encephalomyocarditis virus (10(1)-10(5) PFU/head) was intraperitoneally inoculated into 4 species of small rodents, rats, mice, Syrian hamsters, and Mongolian gerbils, and the susceptibility of these animals to EMC virus was examined virologically and histopathologically 3 days after infection. Viral replication was detected in the brain (mice), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No viral replication was detected in rats. Histopathological changes were seen in the brain (mice and hamsters), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No histopathological changes were seen in rats. The present results suggest that it may be quite possible to produce EMC virus-induced diabetes mellitus not only in mice but also in hamsters and gerbils.

Animals↗
PubMed1987

Age-related non-neoplastic lesions in the heart and kidneys of Syrian hamsters of the APA strain.

Spontaneous cardiac and renal lesions in APA hamsters were examined histopathologically. Myocardial degeneration, valvular thickening, coronary arterial degeneration and increase in heart weight were common in old hamsters. These changes, which suggest cardiac failure, seem to be related to cardiac thrombosis which predominantly affected the left atrium and was found in over 40% of each sex over 16 months of age. Neither glomerular amyloidosis nor arteriolar nephrosclerosis was detected. In general the histopathology of renal lesions in APA hamsters resembled that of the condition known as glomerulonephrosis in rats. Renal lesions occurred more frequently and more severely and developed more rapidly in females than in males. There was no apparent correlation between cardiac thrombosis and renal disease.

Aging↗
PubMed1987

Factors influencing the incidence and severity of swine-serum-induced bile duct lesion in mice.

The detailed histopathology of the swine-serum (SS)-induced bile duct lesion and some factors influencing the incidence and severity of the lesion were examined. The lesion was expressed as an eosinophilic and proliferative cholangitis affecting almost the full length of the biliary tract. It appears to be a useful new model of bile duct diseases. The co-existence of sufficient anti-SS antibody together with repeated injection of SS were necessary to produce this lesion. The lesion could be induced reproducibly by intraperitoneal injection of 0.05 to 0.2 ml of swine serum twice a week for 4 weeks in young BALB/c mice.

Animals↗
PubMed1986

Mouse strain difference in bile duct lesions induced by swine serum injections.

The mouse strain difference in bile duct lesions was studied on male A/J, BALB/c, C57BL/6, C3H/He, DBA/2 and DDY mice 4 weeks old given intraperitoneal injections of swine serum (0.05 or 0.2 ml per mouse) twice a week for 4 weeks. The hepatic lesions were restricted to the portal tract. Biliary epithelial cells showed hypertrophy and hyperplasia, and eosinophilic and homogeneous or needle-shaped material appeared in the cytoplasm of such hypertrophied epithelial cells and in the ductular lumen. Around these damaged biliary epithelia, eosinophil leukocyte and plasma cell infiltration with proliferation of collagen fibres was commonly detected. These changes became more apparent with increasing size of bile duct. Such histopathological characteristics of hepatic lesions were essentially the same in all strains, but the severity showed a clear strain difference: the lesion was marked in the DDY, A/J and BALB/c strains, moderate in C3H/He and slight in C57BL/6 and DBA/2. A high production of anti-swine-serum antibodies associated with a marked increase in the number of mouse IgG-producing lymphocytes in the spleen was detected in the strains showing the marked hepatic lesions.

Animals↗
PubMed1986

Histopathology of streptozotocin-induced diabetic DBA/2N and CD-1 mice.

Histopathological examinations were carried out on female DBA/2N and CD-1 mice which were autopsied 4 and 12 weeks after six daily intraperitoneal injections of streptozotocin (SZ). Histopathological changes related to SZ treatment were found in the pancreas, liver and kidneys. Little difference was observed between the two strains in the histological changes of the pancreas (a decrease in size of the islets, and degranulation and a decrease in the number of B cells) and liver (hypertrophy of hepatocytes and cytoplasmic invagination into hepatocyte nuclei). With regard to the changes in the kidneys, DBA/2N mice showed characteristic inclusions positive to periodic acid-Schiff reagent in the distal tubule epithelial cells, while CD-1 mice showed remarkable luminal dilatation and epithelial cell deformation of distal tubules. SZ-induced diabetes had no influence on the development of spontaneous cardiovascular lesions in DBA/2N mice under the present experimental conditions.

Animals↗