As already described, potency is tremendous and its developmental change is delicate which is caused by direct or indirect relationships of chemical substances inside the embryo and in between the areas. In order to confirm the relationships, the inductive action in the normal development of the crystalline lens was observed by using the tadopole of the larva bulgaris japonica. The following conclusions we re obtained. 1) The retina in amphibian is formed by the sustentacular cells and fibers of Willer, migration in the deep layer of the epithelial cells, and the expansion of the protoplast. The origin of glial tissues, excluding the sustentacular cells and fibers, could not be elucidated in our specimen. These glial tissues, however, appear t o be epithelial-cells derivatives, as Bonnet and Peter explained. 2) The lens is induced from the sense layer, or the outer surface in the deep layer, with the radial sustentacular fibers of Muller as its inductor, and with m elanin granules as its induction factor. This fact is also the case with the regenerat ion of the crystalline lens. 3) According to O. Hertwiz, the external limiting membrane of the retina is formed by secretion. We, however, maintain that this specific membrane is a part of the protoplast remaining of the visual-cavity surface of the epithelial cells, or thin bla ck plates. 4) Melanin granules always attach to the surface of the radial sustentacular cells and fibers of Mfillar and are given to the mother tissues by the entering of the fibers. 5) Melanin appears to develop in the form of yolk granules. We, however, were unsuccessful in proving that this pigment granule, melanin, develops from melanoblast. 6) In amphibian, the optic vesicles commence to develop first at the 19 th stage of the development, and from the optic vesicles which contacted the outer surface, th e radial sustentacular fibers migrate into the sensory-layer tissues at the 20th and 21 st stages of development. At the 22nd stage, the optic vesicles begin to develop into the optic cup. 7) O. Hertwig maintains that the internal limiting membrane is formed by secretion. Our observation, however, seem to indicate that a part of the sustentacula r fibers remaining on the lateral outer-surface of the eye cup composes, or is responsible for composing, the internal limiting membrane. 8) We were not successful in clarifying the gluey connection of the processes of Müller's fibers and the visual cells between the fiber baskets of Müller's fiber s enveloping the basement layers of rods and cones and the cubic or short colu mnar cells in the yellow-coloring epithlium layers, as mentioned by W. Kolmer (1936). 9) J. Mann, W. Kolmer et al. report that in vertebrate species and the human fetus the ganglion cell layers in the innermost cell layers of the retina appear first, and O. Hertwig reports that the layer of rods and cones appears last. In our amphibi an tadopole, the pigmented layer of the retina was formed first (2nd 5th stage of development), and the inner plexiform layer, the nuclear layer, and the ganglion ce ll layer appeared respectively (26th stage), and the nerve fiber layer became distingu ishable (27th and 28 th stage). The outer plexiform layer and Henle's fibe r layer, however, did not yet appear as late as at the 31st stage. We, therefore, coul d not distinguish the outer nuclear layer from the inner one. 10) The development of the crystalline lens varies from animal to animal, as many researchers have pointed out. In amphibian, the lens is formed from the sense layer of the outer surface in the deep layer in contact with the optic vesicle, by the induction of the sustentacular fibers of the optic vesicle.
近年,心臓外科の著しい進歩により,手術適応がより複雑かつ重症の心疾患にまで拡大されるに伴い,体外循環下開心術勲時における心筋保護法は手術の必要欠くべからざる補助手段となっている.すなわち,心内外手術操作をより容易かつ確実安全に施行できるよう,いわゆるcross-clampingにより上行大動脈を遮断し,自然の冠状動脈血流を停止させ,手術野を比較的乾いた,かつ静止した状態(dry and quiet field)におき(任意心停止法),しかも術中および術後に心筋の形態的機能的破綻を残さないようにするため,諸種の心筋保護法が考案されている.しかしどの方法が最も実用性にとみかつ効果的であるかという点については,なお論議のあるところである. 教室では,この目的のため冷却自家血による低流量,低圧持続冠灌流法を考案し,過去数年来臨床的に用いて好成績をあげているが,本研究では実験的に正常犬および左室肥大犬を用い,本法ならびに現在臨床的に行われている他の1,2の方法を施行し,それらを心筋の超微形態学的観点から比較検討し,若干の知見を得たので以下に報告する.
It has long been suggested, through Lee's and other investigators' light microscopical studies, that necrotic changes may play an important role in the ceroidogenesis. On the other hand, Maeda presumed that ceroid is composed of glycoprotein- and lipid-containing compound substances which may be derived from red cell stroma or necrotic tissue. Thereupon an attempt was made to verify the participation of hepatic necrotic lesion in the ceroidogenesis in Kupffer cells in mouse liver by carbon tetrachloride inhalation. Mice were forced to inhale carbon tetrachloride (CCl4) vapor 5 to 103 times (at a rate of three times a week); specimens from the mice liver were used for an electron microscopy after completion of the CCl4 inhalation. The necrotic lesion at vario us stages at the hepatic acinar center was light and electron microscopically observed throughout the whole process of the experiment. The necrotic liver cells showed cytoplasmic concentration and an increased matrical density of the cytoplasm in which cellular organellae were relatively well preserved. These features are thought to correspond to those of “shrivelled necrosis” termed by Takagi (1964). The necrotic liver cells showed all stages of focal cytoplasmic degradation and contained several autophagic vacuoles in which denatured cellular organellae were visible. Part of these necrotic liver cells and their cellular debris were found to be phagocytized by Kupffer cell, which contained much ceroid consisting of the aggregation of numerous pigment bodies. It was noteworthy, especially in the early stage of the experiment, that, in addition to moderately osmiophilic, round or oval bodies and highly osmiophilic granules, fragments of a membranous structure arranged haphazardly and sometimes remnants of denatured cellular organellae were found in many phagolysosomes constituting ceroid. These fragments were assumed to be derived from denatured cellular organellae of liver cells which have undergone severe injuries or “shrivelled necrosis”. During the experimental process the phagolysosomes containing these fragments in Kupffer cells were increased in size and fused each other, showing a very complex configuration characteristic of mature ceroid seen at the end of the long-term experiment. The above findings are thought to suggest that the phagocytosis by Kupffer cells of necrotic liver cells and their cellular debris plays an important role in the ceroidogenesis in the Kupffer cells; accordingly they appear to support Maeda's supposition that origin of ceroid sho uld be sought into compound substances including glycoprotein.