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Biomedical subjects

C Nishiyama

Publications and source records attributed to C Nishiyama.

29 records · Page 2Linked to original sources
PubMed1993

Metabolic characteristics of rat liver cytosolic 5SRNA.

5SRNA were purified from the cytosol, ribosomes, nucleoli and nucleoplasm of rat liver. The 5'-terminal and 3'-terminal sequences of these 5SRNA species were shown to be the same. The time course of changes in specific activities of these 5SRNA in rat liver, 20 min to 16 h after intraperitoneal injection of [14C]orotic acid, were investigated. The specific activity of cytosolic 5SRNA increased almost linearly for 3 h, without a lag, to a high value, then decreased rapidly. The specific activity of cytosolic 5SRNA was much higher than the specific activities of 5SRNA from the other cellular components over 45 min to 6 h after intraperitoneal injection, although at 20 min the specific activity was similar to that of nucleoplasmic 5SRNA. Thus, cytosolic 5SRNA of rat liver is characterized by a high rate of turnover, which was shown to be comparable to that of heterogeneous nuclear RNA. The specific activity of 5SRNA, 45 min to 6 h after intraperitoneal injection, was as follows; cytosolic > nucleoplasmic > nucleolar > ribosomal 5SRNA. The specific activity of nucleoplasmic RNA that migrated slightly slower than nucleoplasmic 5SRNA on PAGE was much higher than that of cytosolic 5SRNA or nucleoplasmic 5SRNA, and so may be the precursor of nucleoplasmic 5SRNA. Together, these results indicate that cytosolic 5SRNA is transferred from the nuclei to the cytosol immediately after maturation of the precursor of nucleoplasmic 5SRNA without entering the nucleoplasmic pool of 5SRNA.

Animals↗
PubMed1993

Determination of three disulfide bonds in a major house dust mite allergen, Der f II.

Der f II is a major mite allergen consisting of 129 amino acid residues. Der f II contains six cysteine residues, suggesting the existence of three disulfide bonds which would stabilize this small protein. As the first step in revealing the relationship between the structure and the allergenic property of Der f II, the formation of disulfide bonds was examined. Der f II purified from Dermatophagoides farinae was treated with lysyl-endopeptidase or proline-specific endopeptidase, and the peptide fragments thus generated were separated by reverse phase high performance liquid chromatography. Determination of the amino acid sequence of each peptide collected in this way proved the existence of three disulfide bonds between Cys8 and Cys119, Cys21 and Cys27, and Cys73 and Cys78.

Allergens↗
PubMed1991

Prenatal and postnatal development of the CGRP-immunoreactive innervation in the rat kidney.

Calcitonin gene-related peptide (CGRP) immunoreactive afferent nerves were seen intrarenally by prenatal day 16. They grow rapidly and CGRP positive nerves are observed at birth associated with the arterial and venous vascular tree, forming a rich plexus in the pelvic region and in the connective tissue located near the corticomedullary region. The distribution and extent of CGRP immunoreactive nerves suggest that at birth the rat is able to provide information on the status of the kidney to be integrated in the mechanisms of body fluid homeostasis.

Aging↗
PubMed1990

[Relation between movement of acid or alkaline proteinase from Trichophyton rubrum and the growth of fungus, pH in medium].

We have previously reported that T. rubrum produced a new type of extracellular proteinase in liquid medium containing bovine serum albumin. This enzyme had an optimal pH 4.5 for azocoll. In this paper, we studied about the relation between movement of acid or alkaline proteinase and environmental pH. In the beginning of cultivation, acid proteolytic activity increased radically, and 3 or 4 weeks later, it was decreased. In place of acid proteinase, alkaline proteinase which had an optimal pH 8.0 was increased gradually. During incubation of T. rubrum in bovine serum albumin medium which was adjusted to pH 6.0, the pH of medium was gradually increased to about pH 7.0 toward 4 weeks. The growth of T. rubrum increased until pH in medium was fixed to pH 7.0.

Aspartic Acid Endopeptidases↗
PubMed1989

[The relation between the growth and extracellular proteolytic activity in trichophyton rubrum, comparing isolates from granuloma trichophyticum with tinea superficialis].

Trichophyton rubrum, a major pathogenic fungus in dermatophytosis, produced a new type of extracellular proteinase, in addition to those previously reported, when cultivated in liquid medium containing bovine serum albumin. This enzyme had an optimal pH 4.5 for azocoll and was found in both isolates from tinea superficialis and granuloma trichophyticum. The proteolytic activity of isolates from granuloma trichophyticum were superior to isolates from tinea superficialis in both acid and alkaline proteinase. But the growth of T. rubrum isolates from tinea superficialis were better than that from granuloma trichophyticum.

Endopeptidases↗
PubMed1986

Increase in the frequency of gamma-ray induced chromosomal aberrations in mammalian cells by post-treatment with novobiocin.

The effect of novobiocin (an inhibitor of DNA topoisomerase and polymerase) on the frequency of chromosomal aberrations was examined in Chinese hamster V79 cells irradiated with gamma-rays in the plateau phase of growth and subcultured in the presence of novobiocin until the first mitosis after irradiation. Novobiocin alone affected cell survival, DNA synthesis and the mitotic frequency of unirradiated cells in a dose-dependent manner, without causing any significant increase in the frequency of chromosome- or chromatid-type aberrations. The frequency of chromosome-type aberrations induced by gamma-radiation was not influenced by novobiocin at 200 microM, but the frequency of chromosome deletions (but not rings and dicentrics) showed a two-fold increase when 300 microM novobiocin was present. Irradiation produced a low level of chromatid-type aberrations and post-treatment with novobiocin at concentrations greater than 100 microM significantly increased the frequency of chromatid gaps and breaks. The results support the idea that different radiation-induced lesions lead to chromosome- as opposed to chromatid-type aberrations.

Animals↗
PubMed1985

Effect of novobiocin on the frequencies of chromatid-type aberrations and sister-chromatid exchanges following gamma-irradiation.

The effect of novobiocin on the frequencies of chromatid-type aberrations and SCEs was examined in Chinese hamster V79 cells which were exposed to gamma-rays and post-treated with novobiocin. While no chromatid aberrations were induced in the unirradiated cells by novobiocin, the frequency of SCEs was slightly increased by treatment with novobiocin alone. Irradiation of G2 cells produced multiple chromatid-type aberrations and post-treatment of the irradiated cells with novobiocin resulted in a significant increase of the aberrations, including chromatid gaps and breaks. In contrast, novobiocin failed to increase the frequency of SCEs induced by gamma-rays when the irradiated cells were post-treated with novobiocin.

Animals↗
PubMed1983

A case of generalized granuloma trichophyticum.

A 59-year-old man visited our hospital. The patient had suffered from generalized tinea superficialis for thirty years, had been treated with several topical antifungal preparations and was administered griseofulvin at another hospital. Clinical manifestations were as follows: There were large pigmentations on the chest, abdomen, and lower extremities. He had several irregular shaped ulcers on the back, left forearm, and right axilla, and glossy granular lesions on the dorsum of the left foot. Generalized eruptions consisting of indurative pustules, red papules, scars, atrophies and depigmentations were also visible. The biopsy specimens taken from the ulcers, the indurative pustules and granular lesions of the dorsum of the left foot were cultured and Trichophyton rubrum was isolated. Laboratory studies showed slight eosinophilia, Mantoux reaction 56 X 40 mm, Trichophytin reaction 5 X 5 mm, IgE 4000 IU/dl. Histological findings were as follows: Fungal elements were observed in the horny layer, in the spindle cell layer, and in the dermis. Histologic features were both abscesses and granulomas with giant cells. According to the pathologic features of the lesions, the parasitic forms of the fungus changed. Abscesses and granulation tissues containing histiocytes and many multinucleated giant cells were observed in the dermis. Various sizes of arthrospores and various shapes of hyphae were stained by PAS. Most of these fungal elements dissolved in the abscesses and granulomas. However, a few survived.

Adult↗