摘要:

To overcome the legally imposed limit on atmospheric concentration of formaldehyde of 1 ppm a method for fixation and storage of material for dissection has been developed. After intraarterial installation of formaldehyde the specimens were extracted in dilute ethanol and stored in the extraction fluid or enclosed in plastic sheets or bags, in a refrigerator. With this method the atmospheric formaldehyde concentration was kept below 0.5 ppm.

ISSN:1422-6405    

DOI:10.1159/000145490

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Transverse sections of the semimembranosus muscle of a control (C) line of Japanese quail and of a line (P) selected for high body weight at 4 weeks of age were observed for nuclear content. The two lines were sampled at 4 days posthatching and at 4 weeks of age. The relative number of satellite cells decreased from 4 days to 4 weeks of age. The total number of satellite cells, however, appeared to increase as muscle length increased; this relation was not influenced by line effects. It was concluded that the greater number of nuclei in the longer fibers of P-line quail was principally the consequence of a greater mitotic rate in the satellite cells of this line compared to the C-line quail.

ISSN:1422-6405    

DOI:10.1159/000145491

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The existence of a limited population of neither adrenergic nor cholinergic nerve fibers was observed in the rat cornea. These nerve fiber-like structures have a selective affinity for quinacrine and are not altered by chemical sympathectomy. The findings are discussed.

ISSN:1422-6405    

DOI:10.1159/000145492

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

156 abdominal preparations were explored by arteriography, corrosion and dissection. The arteria mesenterica inferior (AMI) ends by bifurcating into the two arteriae rectales superiores. The key to the interpretation of the AMI is the recognition of an arteria colosigmoidea that gives off one or more rami sigmoidei. In the presence of an arteria or ramus colic, sin. access, usually from the superior mesenteric artery, the left colic artery is absent, atrophic or displaced. The sigmoid branches (usually three) arise from the colosigmoid, the left colic or the distal portion of the AMI. Usually, the last sigmoid artery gives branch to the rectosigmoid colon. The rectosigmoid artery arises from the AMI between arteria sigmoidea ima and the terminal bifurcation of the former. It may be replaced by the descending branch of the a. sigmoidea ima. They irrigate an extensive part of the anterior wall of the bowel.

ISSN:1422-6405    

DOI:10.1159/000145493

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Data on the frequency and patterns of hair distribution on the phalanges of the hand are available from different parts of the world. However, the literature reveals that the African continent has so far not been explored adequately in this respect. The present investigation was undertaken to document the findings from Nigeria. A random sample of 585 male and female students and staff of the University of Calabar, Nigeria, between the ages of 18 and 30 years were examined. All the cases considered were Nigerians born to Nigerian parents. It was interesting to observe that in 4% of the males and in 5% of the females hair on the first phalanx was absent which has not been reported so far in any other population. The presence of hair on the middle phalanx also was significantly less (21 %) as compared to the findings of other authors in different populations. The distal phalanges never showed hair which is quite in agreement with the reports from other workers. Although there is a wide range of variation in presence or absence of hair on the middle phalanx from one population to another, the frequency order remains 4 > 3 > 5 > 2 in all of them including the present report. Further, it is obvious that the frequency of phalangeal hair is lowest in Africans (21%) and highest in the white race (70%). Other races are in between these values.

ISSN:1422-6405    

DOI:10.1159/000145494

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The retinal pigment epithelium of normal adult golden Syrian hamsters was examined by light and electron microscopy, using conventional and enzyme histochemical techniques. Hamster retinal pigment epithelium was composed of a single layer of cuboidal cells that had marked infolding of the basal cell wall and numerous microvillous processes extending from the apical surface. Melanin content varied within each specimen and there appeared to be incomplete or aberrant development of many melanin granules. Many incompletely melanized granules showed acid phosphatase activity. There were the usual cell organelles, including mitochondria, smooth and rough-surfaced endoplasmic reticulum, ribosomes, and Golgi complexes. Large phagosomes increased in number in the morning hours. Autophagic vacuoles and small lipid droplets were commonly seen. Occasional basal bodies, cilia, and root filaments were found. In two specimens, a curious intranuclear para-crystalline structure was observed.

ISSN:1422-6405    

DOI:10.1159/000145495

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The dependence, access paths and functional significance of the intraganglionic laminar nerve endings (IGLEs) in the esophageal wall of the cat are demonstrated. To this end Wallerian degeneration was induced on the vagus nerve by a number of surgical operations performed at the nodose ganglion level. The results show IGLEs to be sensorial receptors dependent on neuronal bodies situated in the nodose ganglion. The nerve fibers on which they depend to reach the esophageal wall gain access via the vagus and the superior laryngeal nerve.

ISSN:1422-6405    

DOI:10.1159/000145496

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

As the skull develops, the tissue of the coronal and sagittal sutures (serrated sutures) assumes a specific structure which in part is practically identical to that of a gomphosis joint and may therefore be regarded as a ‘multigomphosis’. The nature of this structure justifies the assumption that it has to resist mechanical forces exerted on the suture. The results of transplantation experiments with portions of sutures suggest that the sutural structures are determined hereditarily, but that environmental factors are required for these qualities to manifest themsel

ISSN:1422-6405    

DOI:10.1159/000145497

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The intracellular distribution of horseradish peroxidase (HRP) transported intra-axonally from the mesenteric nerve to the wall of the small intestine has been examined electron microscopically. After 2 days, some of the neurons of the myenteric and submucosal plexuses showed an accumulation of HRP. The HRP reaction product consisted of fine, discrete cytoplasmic granules and it was located in lysosome-like dense bodies with a 400–500 nm of diameter. The morphological features of the labelled neurons, with synapses occurring on their surfaces, were apparently different from those of unlabelled neurons. Some nerve fibers were also labelled and could be found in all layers of the small intestine. The labelled neurons project directly towards the celiac ganglia, and due to the synapses on their surfaces, it is supposed that these neurons collect information from other local nerve cells and centripetally convey them to the prevertebral gangli

ISSN:1422-6405    

DOI:10.1159/000145498

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Light microscopy, scanning electron microscopy, and transmission electron microscopy were employed on the anterior wall of the rabbit thoracic aorta with the particular purpose to study endothelial marginal flaps and the structure of stomata under physiological conditions at 100 mm Hg. Intra-aortic pressure monitoring was performed during the whole period of perfusion (2 h), restricting pressure variations to a maximum of ± 5 mm Hg in order to preserve endothelial architecture. We found the endothelial surface uniformly smooth. Marginal flaps of the endothelial cells were mutually overlapping, often forming multiple layers. Underlying flaps might protrude to the lumen between neighbouring flaps as flat mushrooms. Flaps of adjacent cells might diverge for short distances to decover an underlying endothelial cell. Downstream flaps of the cells might be overlapped at their base by flaps of adjacent cells, the extremity of the flap thus appearing as a disc separated from the cell. The small discs and troughs thus formed are considered equivalent to the so-called stomata

ISSN:1422-6405    

DOI:10.1159/000145499

出版商:S. Karger AG    

年代:1982

数据来源: Karger