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Biomedical subjects

Y Sasano

Publications and source records attributed to Y Sasano.

60 records · Page 4Linked to original sources
PubMed1990

[A case of unresectable pancreatic cancer that responded to UFT chemotherapy].

A 77-year-old patient with an unresectable pancreatic cancer was treated with a combination chemotherapy of UFT (600 mg/day, p.o.) and Lentinan (2 mg/week, i.v.). After three and a half months, a partial response (PR) was achieved, based on the criteria of Koyama, Saito, et al. The findings of the follow up CT scans suggested that 600 mg/day of UFT, rather than 300 mg/day, was effective as a chemotherapeutic agent. Although transient thrombocytopenia (62,000/mm2) and eruption were observed during this therapy, no serious side effects were experienced. After eighteen months of this chemotherapy, the patient has not succumbed and manifests a good quality of life.

Adenocarcinoma↗
PubMed1989

Early embryonic mouse mandibular morphogenesis and cytodifferentiation in serumless, chemically defined medium: a model for studies of autocrine and/or paracrine regulatory factors.

During craniofacial and mandibular development at least three interdependent processes become integrated: 1) regulation of time-dependent differential gene expression; 2) positional information resulting in pattern formations; and 3) morphogenesis. The present studies were designed to test the hypothesis that intrinsic and/or paracrine factors regulate the developmental program for embryonic mouse mandibular morphogenesis, histogenesis, and cytodifferentiation. Either E11 or E12 C57B110 (B10.A) strain mouse mandibular processes were cultured in serumless, chemically defined medium for periods up to 9 days in vitro. At selected stages of development 3H-thymidine incorporation into DNA was used to evaluate the mitotic labeling for selected tissue compartments. Macroscopic observations demonstrated that morphogenesis (shape/form) in vitro was comparable to that for in vivo controls. Histological results demonstrated that chondrogenesis, osteogenesis, tooth formation, tongue formation, lip formation, and epithelial differentiation with keratinization were expressed according to sequence, time, and positions comparable to those observed in controls. This experimental approach provided datasets to support the hypothesis that exogenous long-range factors are not required for embryonic mouse mandibular morphogenesis and further suggested that autocrine and/or paracrine factors mediate the timing and position of mandibular development.

Animals↗
PubMed1987

Change of microtubular arrangement around centrioles in rat incisor odontoblasts during cell differentiation.

Three stages during cell differentiation of rat incisor odontoblasts were classified, and change of microtubular arrangement around centrioles in the odontoblasts was examined with three-dimensional analyses using serial ultrathin sections. In the undifferentiated odontoblasts, microtubules were observed to radiate from the pericentriolar area, whereas, in the differentiating odontoblasts, some microtubules became poorly related to the centrioles. In the differentiated odontoblasts, arrangement of most microtubules appeared to have a poor relationship to the centrioles. Throughout the differentiation of the odontoblasts, one of the centriolar pair was ciliated, and Golgi apparatus was invariably observed near the centrioles. The present study suggests that a pericentriolar area, or a centrosome, could function as a microtubule-organizing center (MTOC) in the undifferentiated odontoblasts, but their function might be attenuated during cell differentiation.

Animals↗
PubMed1986

Dynamic behavior of ciliated centrioles in rat incisor ameloblasts during cell differentiation.

Centriolar pairs of ameloblasts were examined in relation to cell differentiation at the growing end of rat incisors. In their undifferentiated phase, including many mitotic cells, most of the centrioles in the ameloblasts were located lateral to the nuclei; the pairs were closely associated to each other. During the differentiating phase, the centriolar pairs moved more distally, always accompanied by the Golgi apparatus; they often became separated from each other. In the early secretory phase, and also in the following secretory phase, the pairs were usually observed distally, often away from the nuclei, and were separated from each other more frequently than in the previous differentiating phase. Throughout these phases of the ameloblast differentiation, one centriole of the pair was invariably ciliated and the Golgi apparatus was commonly associated with the centriolar pair. Such movement and separation of the ciliated centrioles is considered to be involved in the morphological and functional differentiation of the cells.

Ameloblasts↗
PubMedDate not supplied

An immunohistochemical study of regional differences in the distribution of type I and type II collagens in rat mandibular condylar cartilage.

The mammalian temporomandibular joint is a highly specialized diarthrodial joint under multidirectional compressive and tensile forces. In such a complicated biomechanical environment, the phenotypic expression of extracellular matrix may vary in different regions of the mandibular condylar cartilage. To test this hypothesis, immunohistochemical techniques were used to examine the localization of type I and type II collagens in various anterioposterior regions of the condylar cartilage of 4-week-old rats. In the posterosuperior region, which is mainly subjected to compressive forces, a strong reaction for type II collagen was observed in the cartilaginous layer (maturative and hypertrophic cell layers), and a rather weak reaction was observed for type I collagen in the precartilaginous and cartilaginous layers, compared with the reactions in other peripheral regions. Proceeding anteriorly, staining for type I collagen increased, while that for type II collagen decreased. In posteroinferior cartilage, which is subjected mainly to tensile forces because of its direct attachment to the retrodiscal pad, staining for type I collagen was strong, and that for type II collagen was faint in the cartilaginous layer. These results demonstrate that marked regional differences exist in the phenotypic expression of two major collagen components in mandibular condylar cartilage, which may reflect the local functional environment and cellular response.

Adaptation, Physiological↗