摘要:

The stages of regeneration of the basal melanocyte of human skin after Feulgen reaction were found to be granule, unipolar cell, bipolar cell and bidendritic, tridendritic and quadridendritic melanocyte, in that order. The last mentioned cell either divided by mitosis to form two daughter melanocytes or matured to form a replica of the original basal melanocyte of the human skin.

ISSN:1422-6405    

DOI:10.1159/000144711

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Following the observation of 51 embryos and human fetuses of between 9 and 190 mm vertex/coccyx length, cut transversally, frontally, or sagittally, depending on the case, and coloured with HE, Azan, or by the Bielschowsky method, we studied the development, and peripheral innervation of the palatal muscles. We reached a series of conclusions which we put forward in this paper. The m. tensor veli palatini is the one which develops earliest. It derives from the same blastematic mass as the muscles of mastication, and it is innervated by a branch of the n. mandibularis. The m. levator veli palatini and m. pharyngopalatinus coincide chronologically with the appearance of the m. cephalopharyngeus. They derive from the pharyngeal musculature, and are innervated by fibres proceeding from the n. glossopharyngeus, in the case of the first one, and, in the case of the second, by direct branches from the n. glossopharyngeus and the n. vagus, which penetrate the muscle directly, without prior contact with any nerve plexus. The m. uvulae is first formed, at the time the palatine processes close. In the first place, two outlines may be seen; but after 50 mm approximately it is formed by one muscle only, on the medial line; it is innervated by branches which proceed from the posterior n. palatinus. The m. glossopalatinus is the last to appear. It is closely linked to the musculature of the tongue and, therefore, we think that it derives from the hypobranchial musculature, and that it is innervated in the body of the tongue itself, by means of the n. hypoglossus.

ISSN:1422-6405    

DOI:10.1159/000144712

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Morphologic and histochemical characteristics of selected portions of normal arteries from two species known to differ in susceptibility to vascular disease were examined. Arteries were classified as predominantly elastic, muscular or complex. Species differences in the structural organization of the abdominal aortic segment were observed. Arterial mucopolysaccharides were stained more intensely in the tunica intima and media of chicken vessels than within those of the rat, and tended to be most concentrated in proximity of the internal elastic membrane. Histochemical procedures for the demonstration of enzymatic activity revealed inter-and intraspecies variations in vascular metabolism. Pronounced differences in reaction intensity for hydroxybutyrate dehydrogenase and malic enzyme, affecting chicken and rat coronary arteries, were noted. In contrast, these vessels displayed only minimal activity for acid phosphatase. Marked endothelial deposition of alkaline phosphatase reaction products in the arteries of the chicken was demonstrated, while this enzyme’s activity in the vessels of the rat was restricted to the tunica adventitia. The implications of these structural and histochemical factors with regard to vascular susceptibility to disease were discusse

ISSN:1422-6405    

DOI:10.1159/000144713

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The morphogenesis of developmental defects induced by amniotic sac puncture was studied at the gross and microscopic levels. In fetuses recovered from 15 min to 48 h after amniocentesis, a pattern of hemorrhagic lesions, excessive accumulation of interstitial fluid, followed by tissue necrosis and leading ultimately to the reduction or amputation of distal limb segments and morphological changes in the head, was observed. These changes were indicative of venous stasis, hypervolemia and embryonic oxygen deficiency. Γntrauterine compression of the fetus and the obstruction of the fetomaternal circulation were considered to be the primary etiological factors in amniocentesis-induced anomalies which included hemorrhagic lesions, limb reductions and amputations, deformities of the head and abdominal regions, generalized edema and postural moulding

ISSN:1422-6405    

DOI:10.1159/000144714

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The angioarchitectonic regions in the medulla oblongata and the midbrain of 14 grown-up guinea pigs are discribed. According to direction and number of the supplying arteries, three sections are distinguished. The medial part is supplied worst. It contains the medial row of the nuclei of the cranial nerves. The more lateral parts have always double or treble supplies. They are distinguished by a high capillary density. Those parts are associated with the medullar nuclei of the cranial nerves.

ISSN:1422-6405    

DOI:10.1159/000144715

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The effect of alcohol on the pigment epithelium of the chicken was studied. In the treated animals, the apical microvilli were found to cohere into sheets and there was also proliferation of endoplasmic reticulum, myeloid bodies and dense bodies.

ISSN:1422-6405    

DOI:10.1159/000144716

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Laryngeal epithelium of monkeys (M. mulatta, M. nemestrina) ranging in age from late fetal to adult was found to undergo the following developmental changes: (1) progressive elaboration of commissural epithelium prenatally, reaching the adult form of pseudo-stratified columnar ciliated epithelium early in the postnatal period; (2) vocal process epithelium changing from cuboid to stratified squamous tissue during the late prenatal period, and (3) progressive increments in overall epithelial thickness during development, reaching a maximum in the early postnatal period. Chondrocyte density of the cricoid and thyroid cartilage decreased during the late prenatal period, reaching the adult form at the neonatal stage. The evidence suggests that mechanical or metaplastic stresses do not determine the observed tissue changes.

ISSN:1422-6405    

DOI:10.1159/000144717

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Within the lateral ventricles of the brain of Acanthodactylus pardalis, different zones of ependymal cells are recognizable through their fluctuating changes from one into the other. The frontal pole of the hemisphere shows a rather homogeneous ependyma whose cells are laying together. Cell fibers are not visible. Farther caudally, the ventricular wall is subject to some alterations; there are more long-shaped cell nuclei. The ventricular sulci are areas of different ependymal structures. The sulcus terminalis represents a zone of dense-laying cells, whose nuclei possess in several regions more round or more elongated forms. An apical cytoplasmatic border and cilia are often clearly built out. The sulcus lateralis and the sulcus septo-archipallialis have a dense cell layer. The region below the medial cortex, near the sulcus septo-archipallialis, shows tanycytes with long basal fibers. The ependyma of the dorsal striatum shows dorsally as well as laterally, at the ventricle, areas with loosely arranged cells. The orientation of the cell nuclei to the ventricular surface is variable, especially at the ventricular wall of the septum and the opposite side of the striatum, where cell nuclei are to be found whose axis lays no more vertical but parallel to the ventricular surface.

ISSN:1422-6405    

DOI:10.1159/000144718

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

A single dose of actinomycin was applied to young Wistar albino rats in the critical phase of their cerebellar development. The morphological alterations of the cerebellar cortex were studied by means of light and electron microscopy on several postnatal days. The cell types of the cerebellar cortex reacted in different ways toward the noxious substance according to their stage of development. The acute alterations consisted of an edematous reaction of the neuronal and glial perikarya (light degeneration) and a shrinkage of the neurons (dark degeneration). A massive intercellular edema and a rarefaction of glia cells as well as the Purkinje cell fibres proved to be the long-term damage. This pattern of the alteration was discussed regarding the chemodifferentiation of the cells of the cerebellar cortex, the onset of cerebellar function on day 14, and the establishment of a neuroglial functional unit.

ISSN:1422-6405    

DOI:10.1159/000144719

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The innervation of the pulmonary veins was studied with electron microscopy. The adrenergic and cholinergic nerves were differentiated with potassium permanganate fixation. All three layers of the venous wall, namely, the tunica intima, media and adventitia, contained unmyelinated axons. Adrenergic and cholinergic axons were located near the cardiac muscle in the tunica media and near the smooth muscle in the tunica intima. The morphological relationships may explain the pharmacological and electrophysiological responses of the large pulmonary veins observed by others.

ISSN:1422-6405    

DOI:10.1159/000144720

出版商:S. Karger AG    

年代:1977

数据来源: Karger