The choroid in the eye of the eel (Anguilla anguilla)

Summary By means of light and scanning electron microscopy evidence of the existence of a normally organized choroid in the eye of the eel,Anguilla anguilla, is presented.     

Formation of coronary arteries sprouting from the primitive aortic sinus wall of the chick embryo

Summary The formation of coronary arteries in chick embryos was observed by scanning electron microscopy on injected casts as well as by transmission election microscopy. Usually, 2–4 primitive coronary arteries appear from the right aortic sinus below the level of the cusp margin, and 1–3 from the left one. As development proceeds, the arteries are generally reduced in number to form a single definitive coronary artery on each side. Canalization of the arteries seems to take place by partially degenerative changes of the primordia.Thanks are given to Prof. M. Mato, Department of Anatomy, Jichi Medical School, Tochigi for valuable suggestions, and Dr R.J. Adams for stylistic suggestions. The skillful technical assistance of MrS. Ide is acknowledged.     

Mechanical forces in lymphatic vascular development and disease

The lymphatic vasculature is essential for fluid homeostasis and transport of immune cells, inflammatory molecules, and dietary lipids. It is composed of a hierarchical network of blind-ended lymphatic capillaries and collecting lymphatic vessels, both lined by lymphatic endothelial cells (LECs). The low hydrostatic pressure in lymphatic capillaries, their loose intercellular junctions, and attachment to the surrounding extracellular matrix (ECM) permit passage of extravasated blood plasma from the interstitium into the lumen of the lymphatic capillaries. It is generally thought that interstitial fluid accumulation leads to a swelling of the ECM, to which the LECs of lymphatic capillaries adhere, for example via anchoring filaments. As a result, LECs are pulled away from the vascular lumen, the junctions open, and fluid enters the lymphatic vasculature. The collecting lymphatic vessels then gather the plasma fluid from the capillaries and carry it through the lymph nodes to the blood circulation. The collecting vessels contain intraluminal bicuspid valves that prevent fluid backflow, and are embraced by smooth muscle cells that contribute to fluid transport. Although the lymphatic vessels are regular subject to mechanical strain, our knowledge of its influence on lymphatic development and pathologies is scarce. Here, we discuss the mechanical forces and molecular mechanisms regulating lymphatic vascular growth and maturation in the developing mouse embryo. We also consider how the lymphatic vasculature might be affected by similar mechanomechanisms in two pathological processes, namely cancer cell dissemination and secondary lymphedema.     

The regeneration of newt limbs deformed in nature

Summary The regeneration of abnormal limbs from a wild newt population was examined. The abnormalities were: mirror symmetrical reduplications of digit parts, deformed wrists, or limbs with supernumerary digits. Normal regeneration resulted after amputation of the abnormal parts, regardless of the original deformity. The results suggest that the abnormalities are probably the result of local trauma to the limbs.     

针对东方人黑色虹膜识别的光谱选择

本文以东方人黑色虹膜作为研究对象,进行两方面研究:1)对于单一光谱照明,找到某一个最适合东方人黑色虹膜的光谱段;2)对于多个光谱照明,确定东方人黑色虹膜所需要的光谱段数量.第一部分研究中,采用改进的卷积矩阵与频谱能量相结合的算法,对虹膜纹理质量进行评估;采用改进2-DGabor与1-DLog-Gabor相结合的编码方法,获得虹膜匹配性能的指标.实验显示:针对单一光谱照明,700nm对于东方人的黑色虹膜是最优的光谱段.第二部分研究中,采用改进multi-group(2D)2PCA算法,基于多光谱虹膜图像的最大不相关性进行层次聚类分析.实验显示:针对多个光谱照明,3个主聚类可以最好地描述从545nm到940nm的所有光谱段.以上研究在该领域内具有开拓性,解决了东方人黑色虹膜多光谱采集与识别的基础问题,为东方人黑色虹膜的多光谱融合提供了理论依据.     

Influence of lodgement site on the proliferation-kinetics of tumor cells

Summary This paper describes the influence of lodgement site on the proliferation-kinetics of rat ascites hepatoma AH7974. It was demonstrated that there was a difference in labeling indexes between tumor cells in the brain and in the choroid plexus in both single and continuous administration of tritiated thymidine.     

A histochemical study on the innervation of the cerebral blood vessels in the carp.

Adrenergic and cholinergic innervation of the cerebral blood vessels were studied in the carp using fluorescence and cholinesterase histochemistry. Most of the major cerebral and pial arteries were densely innervated with both nerves. Moreover, both nerves, being probably of central origin, were observed frequently on the walls of parenchymal arterioles and capillaries in the sections of the inferior lobe but were only rarely found in the other brain sections.     

A histochemical study on the innervation of the cerebral blood vessels in the carp

Summary Adrenergic and cholinergic innervation of the cerebral blood vessels were studied in the carp using fluorescence and cholinesterase histochemistry. Most of the major cerebral and pial arteries were densely innervated with both nerves. Moreover, both nerves, being probably of central origin, were observed frequently on the walls of parenchymal arterioles and capillaries in the sections of the inferior lobe but were only rarely found in the other brain sections.     

Ultrastrukturelle untersuchungen der juxtaepiphysären kapillaren nach perfusionsfixation

Summary Afger perfusion-fixation, the juxtaepiphyseal capillaries reveal endothelial cells with pores and without basement-membrane. Extravasates of erythrocytes are artefacts and are due to overexpanding of the endothelial cells in a loosened cartilage matrix.     

Transdifferentiation of larvalXenopus laevis iris under the influence of the pituitary

Summary Fragments of larvalXenopus laevis dorsal iris implanted together with the pituitary into the tail fin transdifferentiate into neural retina. On the contrary, in the control experiments the implanted tissues, dorsal iris alone, pituitary, or dorsal iris with liver fragments, do not undergo any retinal transformation.     

Transdifferentiation of larvalXenopus laevis iris implanted into the amputated hindlimb

Summary Fragments of larvalXenopus laevis iris, autoplastically implanted into the stump of the amputated hindlimb, transdifferentiated into neural retina. However, when such iris fragments were implanted into the caudal fin, no transdifferentiative process was observed.Supported by grant from the P.I. ministry.     

Modification by calcium dobesilate of histamine effects on capillary ultrastructure.

The ultrastructure of blood capillaries and venules are studied in rat skin. After i.v. injection of histamine the luminal surface of the endothelial cells show protrusions of variable size. Numerous gaps have been found in the capillary wall, specially in the venules. These alterations are not observed in the animals that were treated with calcium dobesilate before the administration of histamine. In these cases the capillary structure are indistinguishable of the controls. The possible effects of the histamine and calcium dobesilate on the cell coat and cell junctions of the endothelial capillary cells are discussed.     

Skeletal muscle capillary densities during reactive hyperemia

Reactive hyperemia was induced in hindlimbs of rats by occlusion of the femoral artery. Using fluorescein dye as a peripheral vascular marker, we observed that there was an increase in the number of flowing capillaries supplying the muscle fibres following release of the occlusion. The results indicate that the number of flowing capillaries is not dependent on the duration of occlusion (2-10 min).     

La barrière capillaire enzymatique pour la DOPA au niveau de quelques noyaux du tronc cérébral du rat

Summary An enzymatic barrier for Dopa exists at the level of the cerebral capillaries which changes Dopa into Dopamine by means of endothelial decarboxylase. It is abolished by a decarboxylase inhibitor. Its intensity is weaker in structures containing Dopamine (Striatum, Locus Niger). Neurones of the Raphé containing serotonin can be charged with catecholamines. There are close contacts between neurones and capillaries.     

Ultrastructural localisation of substance P and choline acetyltransferase in endothelial cells of rat coronary artery and release of substance P and acetylcholine during hypoxia

Substance P and choline acetyltransferase have been localised in a small proportion of endothelial cells of rat coronary arteries using electron microscopic immunocytochemistry. During a hypoxic period of 1 min, coronary vasodilatation was produced in the Langendorff heart preparation and increased levels of substance P and acetylcholine were released into the perfusate. The possibility that these substances are released from endothelial cells during hypoxia and contribute to the hyperaemic response is discussed.     

Ultrastructural localisation of substance P and choline acetyltransferase in endothelial cells of rat coronary artery and release of substance P and acetylcholine during hypoxia

Substance P and choline acetyltransferase have been localised in a small proportion of endothelial cells of rat coronary arteries using electron microscopic immunocytochemistry. During a hypoxic period of 1 min, coronary vasodilatation was produced in the Langendorff heart preparation and increased levels of substance P and acetylcholine were released into the perfusate. The possibility that these substances are released from endothelial cells during hypoxia and contribute to the hyperaemic response is discussed.     

Skeletal muscle capillary densities during reactive hyperemia

Summary Reactive hyperemia was induced in hindlimbs of rats by occlusion of the femoral artery. Using fluorescein dye as a peripheral vascular marker, we observed that there was an increase in the number of flowing capillaries supplying the muscle fibres following release of the occlusion. The results indicate that the number of flowing capillaries is not dependent on the duration of occlusion (2–10 min).     

Mechanisms of ciliary targeting: entering importins and Rabs

Primary cilium is a rod-like plasma membrane protrusion that plays important roles in sensing the cellular environment and initiating corresponding signaling pathways. The sensory functions of the cilium critically depend on the unique enrichment of ciliary residents, which is maintained by the ciliary diffusion barrier. It is still unclear how ciliary cargoes specifically enter the diffusion barrier and accumulate within the cilium. In this review, the organization and trafficking mechanism of the cilium are compared to those of the nucleus, which are much better understood at the moment. Though the cilium differs significantly from the nucleus in terms of molecular and cellular functions, analogous themes and principles in the membrane organization and cargo trafficking are notable between them. Therefore, knowledge in the nuclear trafficking can likely shed light on our understanding of the ciliary trafficking. Here, with a focus on membrane cargoes in mammalian cells, we briefly review various ciliary trafficking pathways from the Golgi to the periciliary membrane. Models for the subsequent import translocation across the diffusion barrier and the enrichment of cargoes within the ciliary membrane are discussed in detail. Based on recent discoveries, we propose a Rab–importin-based model in an attempt to accommodate various observations on ciliary targeting.