Akiyoshi Kubota

Morphological differentiation of endothelial cells co-cultured with astrocytes on type-I or type-IV collagen

SummaryIn this study bovine aortic endothelial cells were co-cultured with astrocytes from fetal Wistar Kyoto rats. Endothelial cells growing on type-I collagen, development. Although some cells appeared to be mature, horseradish peroxidase penetrated within 1 min of incubation through the intercellular junctions of these endothelial elements maintained on type-I collagen. In contrast, endothelial cells on type-IV collagen, co-cultured with astrocytes, were well developed; their intercellular junctions were well established, and plasmalemmal vesicles reduced in number. As a result, horseradish peroxidase was unable to penetrate through the endothelial cells grown on type-IV collagen and co-cultured with astrocytes because of the reduced extent of the junctional and vesicular transport. These findings reveal that (1) type-IV collagen is essential for the differentiation of endothelial cells, (2) endothelial cell-astrocyte interactions occur during co-culture, and (3) endothelial permeability depends on astrocyte-produced factors, in addition to type-IV collagen.

ASTROCYTE‐CONDITIONED MEDIUM INDUCES BLOOD‐BRAIN BARRIER PROPERTIES IN ENDOTHELIAL CELLS

1. We evaluated the induction of endothelial barrier functions by the type 1 astrocyte‐derived supernatant in culture using horseradish peroxidase (HRP) as a parameter.

FAULTY INDUCTION OF BLOOD-BRAIN BARRIER FUNCTIONS BY ASTROCYTES ISOLATED FROM STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

1. It has been suggested that astrocytes prompt the induction of blood‐brain barrier (BBB) functions in cerebrovascular endothelial cells.

Morphological and functional differentiation of cultured vascular smooth-muscle cells

SummaryIn numerous investigations using cultured smooth-muscle cells, investigators have consistently added 10–20% fetal calf serum (FCS) to the medium to maintain viable cells. In the present study we utilized an optical technique to investigate whether smooth-muscle cells, cultured with or without FCS, maintain their contractile activity in vitro. With such optical measurement, we were able to detect signals due to spontaneous contractions, in muscle cells cultured in FCS-free medium for up to 8 days, and, for the first time, were also able to observe the conduction of these cell contractions.The ultrastructural characteristics of cultured smooth-muscle cells during contractile activity, were also examined by electron microscopy. The cells were mature and well-differentiated, and were packed with numerous myofilaments. They had developed long cell processes, and were linked to one another by gap junctions.These observations indicated that the smooth-muscle cells, cultured without FCS for 7 to 8 days, were morphologically mature and maintained their contractile activity, whereas the cells cultured in FCS-containing medium showed no detectable signs of contractile activity.

Ultrastructural analysis of survival in cultured smooth muscle cells isolated from stroke-prone spontaneously hypertensive rats: effect of growth factors

Abstract.Our previous study in vivo suggested that vascular smooth muscle cells (VSMCs) in stroke-prone spontaneously hypertensive rats (SHRSP) were vulnerable when plasma components were deficient. Therefore, we cultured VSMCs isolated from normotensive and hypertensive rats to clarify the weakness of VSMCs isolated from hypertensive rats and maintained in plasma-deficient conditions by employing ultrastructural and biochemical analyses. VSMCs, obtained from normotensive rats and cultured without fetal bovine serum (FBS) for 1 week, were intact and well differentiated; without FBS for 2 weeks retained their original structures except for several degenerative changes. VSMCs, obtained from hypertensive rats and cultured without FBS for 2 weeks, were extensively damaged and lost their cell organelles. Apoptotic bodies were frequently observed. We also cultured VSMCs in medium containing a variety of growth factors. VSMCs obtained from normotensive rats and cultured with epidermal growth factor or insulin-like growth factor-1 for 2 weeks were almost intact, as were VSMCs from hypertensive rats, although some degenerative changes of cell organelles were observed. VSMCs from hypertensive rats, maintained with platelet-derived growth factor-BB or basic fibroblast growth factor, were generally in poor condition. Thus VSMCs from hypertensive rats have hereditary weaknesses in cell survival including apoptosis and require specific growth factors for their maintenance.

[Intra-atrial metastatic reticulosarcoma associated with "right atrial obstructing syndrome". A case report].

心臓内に腫瘍が発生または転移することはそれ程まれではないが,一般に無症状に経過する場合が多いため,その臨床症状にかんする検索は未だ充分とはいえない,われわれは転移性細綱肉腫瘤が右心房内腔にぶら下がるように発育して超鶏卵大に達し,これが起立時や右下側臥位などで上下大静脈口を圧迫して上下大静脈から右心房内腔への血流の還流障害をおこす結果生じたものと解せられる一連の臨床症状を呈した1症例を経験した.本腫瘤は三尖弁口にまでは達しえず, ball-valve syndromeとは異なる“右心房充塞症候群”と新しく命名しうる症候群をもつた症例と解せられた.