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Biomedical subjects

S Miyabara

Publications and source records attributed to S Miyabara.

At least 37 records · Page 2Linked to original sources
PubMed1988

[A case of cystic changes in a giant leiomyoblastoma of the stomach].

A 44-year-old male was admitted to hospital with a complaint of abdominal distention. A CT scan revealed a giant multicystic mass in the abdominal cavity, a tumor that measured 34 cm in diameter, which had risen from the gastric body and grew in an exophytic fashion with a stalk. Histologic findings exhibited a malignant leiomyoblastoma with cellular pleomorphism and a intracytoplasmic cystic change, which included disseminated nests of immature small round cells. After excisional surgery, the patient has had no sign of a recurrence for the past two years.

Adult↗
PubMed1988

Unilocular fat cells in three-dimensional collagen gel matrix culture.

Three-dimensional culture with collagen gel, developed recently for the in vitro study of some mammalian cells in a more physiological condition than a monolayer culture, was applied for a biological study of unilocular fat cells. Successfully embedded in the gel, the unilocular fat cells were shown to be able to keep their cellular function and actively proliferate. These findings confirm that unilocular fat cells do undergo proliferation under in vitro conditions as demonstrated in monolayer culture.

Adipose Tissue↗
PubMed1987

Proliferation of unilocular fat cells in the primary culture.

Mature white fat cells (unilocular fat cells) have generally been considered to be in terminal differentiation and, hence, to have no proliferative ability. A new method, referred to as "ceiling culture," has been devised in our laboratory to culture unilocular fat cells in vitro. Under such culture conditions, the fat cells continue to exhibit specific functions of lipid metabolism and proliferate extensively. Intracytoplasmic lipid droplets did not inhibit division of the cells. There were two modes of proliferation of unilocular fat cells: "loculus-dividing" cell division, in which the single loculus of fat in the dividing cell was broken down into multiple droplets and distributed evenly between the daughter cells, and "loculus-preserving" cell division, in which the loculus in the dividing cell was minimally broken down and inherited with its shape preserved by one of the daughter cells with the other getting only a small number of fine lipid droplets. Such findings suggest that unilocular fat cells in mature fat tissue in vivo are probably capable of proliferation in such modes under some conditions.

Adipose Tissue↗
PubMed1986

Primary cultures of unilocular fat cells: characteristics of growth in vitro and changes in differentiation properties.

Mature white fat tissue consists primarily of unilocular fat cells. Clearly, the study of the biology of these cells would be most helpful for the elucidation of the mechanism of obesity. We describe a new method termed 'ceiling culture' for culturing in vitro unilocular fat cells obtained from humans and rats. These cells can be maintained in culture for long periods of time and, under such conditions, continue to exhibit specific functions such as lipogenesis and lipolysis. Under the culture conditions described, unilocular fat cells change into multilocular fat cells or cells with a fibroblast-like appearance. These cells then proliferate, form a cell monolayer attached to the substratum, and after becoming confluent, exhibit accumulations of intracytoplasmic lipid droplets. These attached dedifferentiated cells continue to exhibit lipogenesis and lipolysis.

Adipose Tissue↗
PubMed1985

Adrenal cortex of Micromys minutus japonicus (Japanese harvest mouse). Its histochemical and fine structural study.

Micromys minutus japonicus (Japanese harvest mouse) is one of the smallest known mammals and is easily maintainable in the laboratory. The adrenal cortex of this animal is described here for the first time. The morphological structure with histochemistry was essentially the same as that of the mouse or the rat. However, the histochemical activity of steroid 3 beta-OH dehydrogenase in the zona glomerulosa was characteristically positive in this animal and electron microscopically Golgi's apparatus and endoplasmic reticulum were prominent in the glomerular cells. The concentration of aldosterone was high in the serum. These findings suggest the hyperfunction of the zona glomerulosa in this animal.

Adrenal Cortex↗
PubMed1985

Cellular structure and function of mouse adrenocortical tumor cells Y-1 in the post-treatment state of low Ca2+.

Under lowered Ca2+ content and in the post-treatment state of low Ca2+, we studied the cellular structure and functioning in mouse adrenocortical tumor cells, Y-1. These cells had been maintained in Ham F12 medium containing 10% fetal calf serum. The Ca2+ present in this complete medium was 0.39 mM. Under a slightly lowered Ca2+ (0.29 mM) produced by EGTA, the cells had many blebs on their surfaces and specific functional activity decreased in steroidogenesis as did ACTH reactivity. In the post-treatment state of a low Ca2+, the cellular surface was covered with many short microvilli and there was greater cellular activity than in the control cells. When the Ca2+ concentration was below 0.17 mM, the cellular structure and functioning were disturbed, and there was no recovery even at the physiological Ca2+ after the removal of EGTA.

Adrenal Cortex Neoplasms↗
PubMed1984

Atypical polysplenia only with absence of the hepatic segment of inferior vena cava in a middle-aged.

An autopsy case of polysplenia with absence of the hepatic segment of the inferior vena cava in a 53-year-old female is reported. The venous blood from the lower parts of the body was drained through the azygos vein and the superior vena cava into the right atrium. Other than acquired pathological change, the heart was found to be normal. Except for the partial absence of the inferior vena cava, isomerism of asymmetric organs, and heterotaxia of abdominal organs, characteristic of typical polysplenia, were not present. This case of atypical polysplenia suggests the presence of a transitional form in the complex.

Azygos Vein↗
PubMed1983

Immunocytochemistry of the Microtubules of fat-laden cells. Brown fat cells and adrenocortical cells in primary monolayer culture.

Cytoplasmic microtubules of fat-laden cells containing fine lipid droplets, such as brown fat cells and adrenocortical cells, were studied in relation to the metabolism of intracellular lipid. In these cells, the amount and distribution of lipid droplets reflect the state of inherent cellular function. Materials used were primary monolayer culture of fetal rat brown fat cells and that of bovine adrenocortical cells. The method was the immunocytochemistry with anti-tubulin antibody. When brown fat cells were being lipolyzed or the steroidogenesis of adrenocortical cells were being stimulated, the cytoplasmic microtubules in the cells were organized in a radial pattern in response to the behavior of the lipid droplets. It is assumed that the microtubules were in the regulation of cellular function in terms of the metabolism of lipid droplets in these cells. We have devised, in the course of the current study, a double fluorescence technique as an observational method whereby microtubules were observed immunocytochemically and lipid droplets by a secondary fluorescence with phosphine E staining.

Adipose Tissue, Brown↗
PubMed1983

Hormonal sensitivity of brown fat cells of fetal rats in monolayer culture.

The primary monolayer culture of brown fat cells was performed with the brown adipose tissue of fetal rats as the material. Brown fat cells in the culture were highly sensitive to some hormones. Insulin had a marked effect of lipogenesis and it made the cells contain large multilocular lipid droplets. Lipolysis is also mediated by hormones, e.g., epinephrine or ACTH etc., and lipolytic process was controlled through cyclic AMP system. Brown fat cells of fetal rats in monolayer culture seem to be a suitable material for long-term experiment of lipogenesis and lipolysis.

Adipose Tissue, Brown↗
PubMed1982

Trisomy 16 in the mouse fetus associated with generalized edema and cardiovascular and urinary tract anomalies.

Murine trisomy (Ts) 16 occurs in the fetal and neonatal progeny of males doubly heterozygous for the Robertsonian metacentric chromosomes Rb(16.17)7Bnr/Rb(9.16)9Rma and "all acrocentric" females. The developmental aspects of this trisomy were studied between day 12 of gestation and birth. So far, postnatal survival longer than a few hours after birth has not been observed. The frequency of Ts 16 among all implants decreased from more than 20% on day 14 to values between 4% and 7% shortly before term. Main features of Ts 16 are moderate general hypoplasia, slight developmental retardation, and cardiovascular anomalies. These latter were found in 96% of the trisomies, the great majority belonging to the transposition type, i.e., riding aorta, double outlet right ventricle (DORV) and transposition of the great arteries (TGA). Association with common atrio ventricular (AV)-canal was frequent. Other anomalies as "open eyelid", hydronephrosis, and hydroureter seem to be attributable to the effects of retardation. Generalized transient edema was frequent in the later gestational stages of Ts 16. Severe cardiovascular malformation is possible one of the factors responsible for late fetal or neonatal death in some cases. Another factor probably contributing to Ts 16 fetal mortality is insufficiency of placental function due to hypoplasia of the fetal vasculature of this organ. The teratological study of Ts 16 demands interest since evidence has been forwarded to consider this trisomy as an animal model of human trisomy 21.

Animals↗
PubMed1982

The effect of alpha-melanocyte-stimulating hormone on the adrenal cortex of the fetal rat.

The effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on the fetal adrenal cortex in rat was studied in vivo and in vitro. In vivo, an injection of alpha-MSH stimulated the adrenal cortex slightly. Treatment of the adrenal cortex with alpha-MSH in organ culture caused hyperfunctional change in the innermost layer of the cortex, the detection of which was done by electron microscope. This treatment caused at the same time an increase in corticosterone in the culture medium. Furthermore, comparison was made between alpha-MSH and ACTH with respect to their effect on the fetal adrenal cortex.

Adrenal Cortex↗