Biomedical subjects

Seiji Kato

Publications and source records attributed to Seiji Kato.

5 recordsLinked to original sources

PubMed2003

Lymphatic network and lymphangiogenesis in the gastric wall.

A family of growth factors highly specific for endothelial cells was identified more than 10 years ago, in which the receptor of vascular endothelial growth factor C (VEGFR-3) is implicated in the regulation of lymphatic development and regeneration. Comparative studies on the lymphatic network and lymphangiogenesis have been done mainly using combined 5'-nucleotidase (5'-Nase) enzyme and VEGFR-3 immunohistochemical approaches in adult and fetal gastric walls. Developing lymphatic networks represented fewer blind ends and branches than mature networks in whole-mount preparations. Many circular lymphatic-like structures exhibited VEGFR-3 expression and weak 5'-Nase activity in the early embryonic stage, showing visible morphological properties in the lymphatic endothelium. These newly formed lymphatics showed an obvious accumulation in the submucosa and serosa and a variation in the intensity of VEGFR-3 binding to endothelial cells among samples. A reaction product for anti-VEGFR-3 was found on the luminal surface of endothelial cells and on the membrane of some organelles and intraluminal lymphocytes. These findings indicate that an active proliferating feature of the clustered developing lymphatics may create a favorable environment for their sprouting and growth, which may serve as a functional requirement for lymph drainage in the region.

5'-Nucleotidase↗

PubMed2003

Development of a quantitative pachytene chromosome map in Oryza sativa by imaging methods.

A higher GC content region of an Oryza sativa chromosome can be specifically visualized by double staining with propidium iodide (PI) and 4, 6-diamidino-2-phenylindole (DAPI). This procedure allows identification of chromosome 9 from the other rice chromosomes at the pachytene stage. Using rice chromosome 9 as a model, an imaging method to construct a pachytene chromosomal map was developed by quantifying the fluorescence profile (FP) of each chromomere. The pachytene map of chromosome 9 consists of twenty-two chromomeres including four chromomeres within the nucleolar organizing region (NOR) and satellite region. The pachytene map was compared with the corresponding somatic prometaphase map and the linkage map. The differences among the three maps indicate that each map depicts specific biological information, which is difficult to be substituted by the other maps.

Chromosome Mapping↗

PubMed2002

Lymphatic networks in the periodontal tissue and dental pulp as revealed by histochemical study.

The structural organization and fine distribution of the lymphatic networks in the periodontal tissues (gingiva, periodontal membrane, and alveolar process) and dental pulp of animals and humans were reviewed with special reference to histochemical examination by light and electron microscopy. The distinction between lymphatics and blood vessels was made on cryostat sections of undecalcified and calcified teeth treated with EDTA solution and whole mount preparations of periodontal membranes using 5'-nucleotidase (5'-Nase)-alkaline phosphatase (ALPase) double staining. This staining procedure allowed lymphatic vessels in the periodontal tissue and dental pulp to be differentiated from blood vessels. The specificity and localization of the enzyme reactions were confirmed by comparative histochemical studies of the same specimen with light microscopy and scanning or transmission electron microscopy. Well-developed 5'-Nase-positive lymphatic networks were observed on the tissue sections and whole mount preparations of the gingiva, periodontium, and dental pulp. More lymphatic vessels were seen in the root area of the periodontium than in the cervical area. In the dental pulp, lymphatic vessels were more numerous in the central part than in the peripheral odontoblastic layer. These distributions of the lymphatic capillary networks are discussed in relation to their ability to supply lymph to the teeth.

5'-Nucleotidase↗

PubMed2002

Introduction.

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Animals↗

PubMed2002

Scanning electron microscopic observation of immunohistochemically specified stromal cells following the NaOH maceration method.

The present study introduces a method combining immunohistochemistry and a chemical digestion technique applied to scanning electron microscopy (SEM) observation of chemically characterized stromal cells in the myenteric layer of the monkey small intestine. The whole-mount preparation containing the myenteric layer was treated immunohistochemically using small colloidal gold and silver enhancements for detecting a certain type of stromal cell, followed by an alkali maceration method to remove extracellular matrices covering the immunohistochemically stained cells. This method permitted direct SEM observation of the stained stromal cells. Secondary and backscatter electron images clearly visualized the ultrastructure of the immunohistochemically-stained cells and the spatial distribution of the reaction products, respectively. It is suggested that the present method is useful for demonstrating the three-dimensional organization of the chemically specified stromal cells.

Animals↗