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Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 901 records · Page 50Linked to original sources
PubMed1985

Ipsilaterally projecting retinal ganglion cells in the eastern chipmunk (Tamias sibiricus asiaticus).

Ipsilaterally projecting ganglion cells were studied in whole-mounted retinas of the eastern chipmunk (Tamias sibiricus asiaticus) by labelling these cells with horseradish peroxidase (HRP) injected into the optic tract. The HRP-labelled cells were distributed exclusively in the temporal crescent which occupied about a quarter of the whole retinal area. The temporal crescent contained contralaterally projecting cells as well as ipsilaterally projecting cells. The soma size of ipsilaterally projecting cells, especially of those in the dorso-temporal crescent, was significantly larger than that of contralaterally projecting cells.

Animals↗
PubMed1985

Lymphocyte-mediated enhancement of hepatic fibrosis in chronic active hepatitis.

The effect of the supernatant from a culture of liver specific protein-stimulated lymphocytes on collagen production by cultured fibroblasts was examined. The supernatant from the culture of unstimulated lymphocytes was used as a control. Both supernatants were added to the culture medium of L929 fibroblast monolayer. After incubation for 72 hours, 1 microCi of tritium-labelled proline was added to the culture medium of the monolayer. The radioactivity of tritium labelled hydroxyproline incorporated into collagen was measured. The results demonstrated that the supernatant from the culture of stimulated lymphocytes enhanced collagen production in 5 of 6 cases of chronic active hepatitis and in 2 of 14 cases of chronic inactive hepatitis. These findings suggest that cellular immune regulation may play an important role in the development of hepatic fibrosis in chronic active hepatitis.

Adult↗
PubMed1985

Serum levels of aminoterminal type III procollagen peptide in normal subjects and hepatic fibrosis.

Serum levels of aminoterminal type III procollagen peptide in normal subjects were determined by radioimmunoassay. The levels of the peptide markedly increase in infants and gradually decrease with age in childhood. The peptide increases again in prepubertal children and then decreases through adulthood. These findings suggest that increased levels of the peptide reflect accelerated collagen synthesis in the human body. Comparison of serum levels of the peptide with the degree of hepatic fibrosis revealed that the peptide increased in parallel with the progress of hepatic fibrosis.

Adolescent↗
PubMed1985

Morphological correlates of Y, X and W type ganglion cells in the cat's retina.

After physiological recordings with microelectrodes containing horseradish peroxidase (HRP), morphological properties of Y, X and W type ganglion cells were studied on flat-mounted cat's retinas. While all the Y cells (N = 9) and the X cells (N = 8) revealed alpha and beta cell morphologies of Boycott and Wässle [J. Physiol. 240, 397-419 (1974)], respectively, W cells (N = 4) revealed various morphological types including their gamma and delta cells. The Y cells were larger than X cells in soma diameter, but the W cells were of the same range as X cells. Electron microscopic observations of the cross-sectioned nerve fiber bundles provided evidence for the segregation of axon diameters into the three groups corresponding to Y, X and W axons. It was discussed that functional trichotomy of retinal ganglion cells is related to the differentiation more in axon diameter rather than in soma size.

Action Potentials↗
PubMed1985

Distribution and soma size of ganglion cells in the retina of the eastern chipmunk (Tamias sibiricus asiaticus).

Topographic distribution and soma size of ganglion cells were studied in Nissl-stained, whole-mounted retinas of the eastern chipmunk. High density areas in the central retina were elongated horizontally, making up the visual streak. The total count of ganglion cells was estimated as 410,000. Throughout the retina soma size of ganglion cells showed a uimodal distribution, although a distinct population of large cells was found in the dorso-temporal periphery.

Animals↗
PubMed1985

Temporary double representation in expanded ipsilateral retinocollicular projection of neonatally one-eye-removed rats.

Retinotopic representations of the expanded projection to the ipsilateral colliculus were studied in albino rats of various ages after neonatal unilateral eye removal. Besides the projection from the lower temporal retina the projection from the central retina was observed in 3-6 month-old one-eyed rats. Such double retinotopic representation was not observed in 1-month- or 1-year-old one-eyed rats. A postnatally growing temporary process was suggested for the expanded ipsilateral retinocollicular projection in rats.

Animals↗
PubMed1985

Induction of colorectal adenocarcinoma in rats by amylopectin sulfate.

The carcinogenicity of orally administered amylopectin sulfate was studied in F344 rats. Amylopectin sulfate induced adenomas and adenocarcinomas in the rat colorectum. The incidences of tumor induction in groups that were given a 5% diet of amylopectin sulfate for 3, 6 and 9 months were 2 out of 20 rats (10%), 9 out of 20 rats (45%) and 12 out of 20 rats (60%), respectively. Squamous metaplasia of the colorectum persisted in all rats and progressed irreversibly. Amylopectin sulfate was deposited in the colorectal lamina propria, submucosa and regional lymph nodes. Amylopectin sulfate induced a lesion similar to that produced by degraded carrageenan in the rat colorectum.

Adenocarcinoma↗
PubMed1985

Purification and properties of orotate phosphoribosyltransferases from Escherichia coli K-12, and its derivative purine-sensitive mutant.

Orotate phosphoribosyltransferase (OPT) was purified from both Escherichia coli K-12 strain and its derivative, a purine-sensitive mutant. The wild-type OPT had a molecular weight (M.W.) of 47,000 and was composed of two identical subunits (M.W. 23,500). The wild-type OPT showed maximum activity at pH 9.5, and no activity was seen in the absence of Mg2+ or Mn2+ ion. It also catalyzed a reverse reaction, namely orotidine-5'-monophosphate (OMP) pyrophosphorolysis. In this reverse reaction, tripolyphosphate, tetrapolyphosphate, and trimetaphosphate were also effective as pyrophosphate donors. The apparent Km values of the wild-type OPT were 30 microM for orotate and 40 microM for 5-phosphoribosyl 1-pyrophosphate (PRib-PP), and also 3.6 microM for OMP and 13 microM for PPi. On the other hand, the mutant OPT showed increased apparent Km values for all four substrates, 440 microM for orotate, 360 microM for PRib-PP, 33 microM for OMP, and 250 microM for PPi. The mutant OPT required a higher concentration of Mg2+ ion for maximum activity than the wild-type OPT. The nature of the purine-sensitive phenotype of the mutant is discussed from the standpoint of the reactivity of the mutant OPT, which has an increased Km value for PRib-PP (about 9-fold).

Bacterial Proteins↗
PubMed1985

Primary gastric choriocarcinoma. Report of an autopsy case with immunohistochemical study.

An autopsy case of primary gastric choriocarcinoma of a 70-year-old Japanese female is presented. The tumor was initially diagnosed as poorly differentiated adenocarcinoma of the stomach by biopsy. Autopsy revealed co-existence of choriocarcinoma and adenocarcinoma in the stomach and a large amount of human chorionic gonadotropin in the serum. The choriocarcinoma metastasized to the liver, lung, and omentum, and the adenocarcinoma to lymph nodes. In the gastric tumor, immunohistochemical stains showed human chorionic gonadotropin in choriocarcinoma cells, alpha-fetoprotein and carcinoembryonic antigen in adenocarcinoma cells. The pathogenesis and pathological characteristics of primary gastric choriocarcinoma are discussed.

Adenocarcinoma↗
PubMed1985

Susceptibility of Legionella pneumophila to ofloxacin in vitro and in experimental Legionella pneumonia in guinea pigs.

The antimicrobial activity of ofloxacin was tested against 15 standard strains and 37 clinical and environmental strains of Legionella pneumophila by agar dilution susceptibility studies with a new growth medium. The ofloxacin MICs were inoculum dependent and ranged from 0.03 to 0.125 microgram/ml. The antibacterial activities of other agents tested relative to ofloxacin were rifampin greater than ofloxacin greater than josamycin greater than pipemidic acid. Ofloxacin, at concentrations equal to or greater than 0.05 microgram/ml, inhibited the growth of L. pneumophila grown in human monocytes. The therapeutic efficacy of ofloxacin in experimental guinea pig L. pneumophila pneumonia was greater than that observed with erythromycin or josamycin therapy; it was less effective than was rifampin. Ofloxacin was very active against intracellular L. pneumophila in these experiments and should be studied in the therapy of human Legionnaires disease.

Animals↗
PubMed1985

Phenotype character of the methylglyoxal resistance gene in Saccharomyces cerevisiae: expression in Escherichia coli and application to breeding wild-type yeast strains.

The gene responsible for the methylglyoxal resistance of Saccharomyces cerevisiae was cloned, and its phenotypic characteristics were investigated. S. cerevisiae cells with the gene could accumulate large amounts of glutathione in the medium and should remarkably high resistance to various toxic compounds such as methylglyoxal, tetramethylthiuram disulfide, iodoacetamide, and heavy-metal ions. The gene was also expressed in Escherichia coli cells, and the resistance of E. coli cells to toxic compounds also increased as observed for S. cerevisiae cells. The phenotypic characteristics of the gene were applicable to the selection of the transformants of wild-type yeast strains having no genetic markers.

Aldehydes↗
PubMed1985

Defective actin organization in cultured skin fibroblasts from individuals with inherited colon adenocarcinoma is not restored by addition of fibronectin.

Cultured skin fibroblasts from patients with hereditary adenomatosis of the colon and rectum (ACR) have a disorganized cytoskeleton. Since fibronectin has been found to restore normal cytoskeletal and cellular morphology to transformed cells, we investigated the fibronectin pattern in ACR cells. We found that although both fibronectin synthesis and binding to the cell surface were apparently normal, addition of fibronectin did not restore a normal distribution of actin cables to ACR cells. The data suggest that coupling of cell surface-bound fibronectin to the cytoskeleton might be constitutively defective in ACR cells.

Actins↗
PubMed1985

Sex differences in acquired cystic disease of the kidney on long-term dialysis.

Acquired cystic disease of the kidney in chronic glomerulonephritic patients who had been on hemodialysis more than 3 years (4.5 +/- 1.2 years at the base line examination), were followed for 3.6 +/- 0.5 years (at the follow-up examination) by computed tomography (CT scan). The renal volume in the 25 male patients was significantly greater at the follow-up examination than at the base line examination. On the other hand, the renal volume in the 12 female patients was similar on both examinations. The enlargement of kidney volume more than twofold during the follow-up was seen in 9 of 25 male and none of 12 female patients. The grade of cystic transformation was increased in male patients during the follow-up period. These results indicate that sex-related endogenous substances might play a role in the pathogenesis of acquired cystic disease.

Adult↗
PubMed1985

Experimental polymyxin B-induced interstitial lung disease characterized by an accumulation of cytotoxic eosinophils in the alveolar structures.

A variety of lung disorders are associated with the accumulation of eosinophils in the alveolar structures. To help understand the role of eosinophils in these disorders, an animal model of eosinophilic lung disease was developed. Administration of an aerosol of polymyxin B to guinea pigs (3 times per wk for 4 wk) produced diffuse interstitial lung disease with alveolar wall thickening and an alveolitis characterized by marked increases in eosinophils and alveolar macrophages. Bronchoalveolar lavage confirmed the presence of significantly increased numbers of eosinophils and alveolar macrophages in polymyxin-B-treated animals compared with those in control animals. Using density gradient centrifugation, approximately 10(7) eosinophils could be purified from the lungs of a single polymyxin-B-treated animal. Importantly, eosinophils purified from the lungs from polymyxin B-treated animals exhibited significant spontaneous cellular cytotoxicity for human fetal lung fibroblasts. In contrast, neither eosinophils from control animals nor alveolar macrophages from either group of animals were cytotoxic. These findings demonstrate that eosinophils possess effector processes capable of injuring the lung parenchyma and suggest that eosinophils can contribute to the pathogenesis of the interstitial lung disease.

Aerosols↗
PubMed1985

Toxicological studies of hydroxypropylmethylcellulose acetate succinate--acute toxicity in rats and rabbits, and subchronic and chronic toxicities in rats.

The acute toxicity (in rabbits and rats) and the subchronic and chronic toxicities (in rats) of Hydroxypropylmethylcellulose acetate succinate (HPMCAS), a potentially useful pharmaceutical excipient, were investigated. 1) In the acute toxicity study (single oral dose of 2.5 g/kg), no deaths or behavioral abnormalities were observed. Thus, LD50 is higher than 2.5 g/kg. 2) In the subchronic toxicity study (0.63, 1.25 or 2.5 g/kg daily as a single oral dose in the morning, 6 days per week (not Sunday) for 2 months), no significant behavioral abnormality was observed. There was some decrease in body weight gain in rats of both sexes, but the effect was not statistically significant. 3)In the chronic toxicity study (1.25 or 2.5 g/kg daily as a single oral dose in the morning, 6 days per week (not Sunday) for 6 months), no significant behavioral abnormality was observed. There was some decrease in body weight gain in male rats, but it was not statistically significant. 4)Various biochemical and physiological abnormalities in rats were noted in all groups (including the control groups) in the toxicity studies, but there appeared to be no significant dose-related finding attributable to the administration of HPMCAS.

Administration, Oral↗