摘要:

AChE-containing neurons have been demonstrated by electron-microscopical histochemistry in the neocortex of the rat. These cells are mainly located in layer VI. AChE activity is seen in the cisternae of the RER, in subsurface cisternae and in the dendritic membranes.

ISSN:1422-6405    

DOI:10.1159/000145002

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The effects of sewage sludge on the survival of the common carp, Cyprinus carpio, were investigated. It was noted that, when the concentrations of the sludge used for rearing carp exceeded 0.6%, the fish died within 42 days, whereas those reared in 0.2% sludge remained alive and healthy during the trial period. The body and the gills of the dead fish were covered by a veil-like film which looked like coagulated mucus and was formed by the heavy metal ions from the sludge reacting with some constituents of the mucus secreted by the gill. The histopathological symptoms of the various organs further demonstrated that internal injury in liver and kidney was also an important feature of the intoxicants as well as external damage, especially the particles observed around the gills. It was concluded that the optimum concentration of sludge to any species of fish should be determined by testing a series of concentrations before using it as a supplementary fish feed or fish pond fertilizer.

ISSN:1422-6405    

DOI:10.1159/000145003

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

An experiment was performed to compare the effects of stressors – cold, heat and noise – on primary wound activity (i.e., wound closure in the first 24 h after wound infliction) and on rate of healing in mice. A significant correlation was found between reduced primary wound activity and a faster rate of healing. Conversely, a correlation was found between relatively greater primary wound activity and a slower rate of healing. A possible explanation of this correlation is a compensatory mechanism inherent to the skin healing process. This mechanism is visualized as (1) stress exposure affecting the skin by (a) causing it to become thinner and tauter and (b) causing it to have less elastic recoil; therefore, (2) when a square wound is produced in stressed skin, (a) the wound does not recoil readily or gapes soon after cutting and (b) a longer wound perimeter results. Because there is evidence that rate of healing is governed by cells on the wound perimeter, the greater the perimeter, the greater the number of cells that will undergo rapid mitosis and the faster will be the rate of healing. Therefore, stressed skin will heal at a faster rate, compensating for the loss of elasticity and cellular depletion caused by stress. This study is of interest to anthropology because it deals with dynamic adaptation, trying to grasp the meaning of the elusive endocrine interface between environmental stimulation and a measurable physical entity like healing. This work may have revealed a functional complex that is common to the healing of all mammalian skin, whereby retarding effects of stress on the healing process are obvia

ISSN:1422-6405    

DOI:10.1159/000145004

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Cells considered to be lymphocytes are reported in the epithelial lining of the excurrent ducts of the testis of normal and vasoligated domestic fowl. They resemble those already reported in the rat and monkey epididymal epithelium, the human intestinal mucosa, and in the bursa of Fabricius. The cytoplasm is usually less dense than that of adjacent epithelial cells, and contains only a few organelles. The nucleus is highly heterochromatic and with no definite nucleolus. Cytoplasmic processes are found to extend from the cell in between epithelial cells. The possible role of these cells in the reproductive tract of the cockerel is discussed.

ISSN:1422-6405    

DOI:10.1159/000145005

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The brains of female and male Wistar (W) rats were larger than the brains of Long-Evans (LE) rats at all ages and males had larger brains than females (p < 0.001). These differences did not correlate with differences in body weight. Brains of female and male LE and W rats aged 60 days (n = 48) were perfused with 10% neutral formalin and cut and stained with hematoxylin and eosin. Matching sagittal sections were selected for the study of the cerebellum, hippocampus and the olfactory bulbs. Brains from a similar group of 48 animals were prepared according to the Golgi-Cox method and were used for the study of Purkinje cells. Males had a 5.7% larger cerebellar area than females (p < 0.001). This difference was mostly due to a 6.1 % difference in the area of the molecular layer and a 6.2% difference in the granule cell layer (p < 0.001). Males also had more granule cells (8.1%), p < 0.05) and Purkinje cells (7.2%, p < 0.05) than females. The strains were similar in the area of the cerebellum, but LE had more Purkinje cells (9.6%, p < 0.01), packed more densely (11.1%, p < 0.01) than W cells. The results of the Golgi preparation suggest that the dendritic tree of the Purkinje cells was larger in the LE strain (10.5%, p < 0.05). There were no sex differences for the hippocampus and the olfactory bulbs. The area of the hippocampus did not differ between strains but W had a longer and thus thinner granule cell layer (15.2%, p < 0.001). The hippocampal granule cells were packed more densely in W strain (8.9%), p < 0.05). The olfactory bulb granule cell layer of W rats was larger than that of LE rats (14.9%o, p < 0.05). Such anatomical differences may be correlated in subsequent studies with behavioral differences. Indeed, there are indications that the strain LE which possesses a greater number and larger Purkinje cells also perform better in motor tasks.

ISSN:1422-6405    

DOI:10.1159/000145006

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Vitamin A deficiency was induced in young adult male rats by feeding them with a synthetic vitamin-A-deficient diet. The histology of their testes was examined periodically from 1 to 20 days following the point where the animals ceased to gain weight. The earliest sign of histological change in the seminiferious tubules, which occurred at day 3, was the sloughing of spermatids and spermatocytes into the lumina of the seminiferous tubules. Pyknotic cells were seen throughout the epithelium in a significant number beginning at day 4 or 5. Most of them were dead spermatocytes and early spermatids. Abnormal multinucleate giant cells appeared during days 6 and 8, and were thought to be abnormal spermatids which failed to complete cytoplasmic division and further differentiation into spermatozoa; eventually they degenerated. Quantitation of germinal cells in the tubules revealed that the number of spermatids decreased sharply between days 2 and 8, and reached zero level at day 10 after the animals ceased to grow. The number of spermatocytes decreased rapidly between days 5 and 12, and the rate of their decrease was relatively slow during the periods preceding and following this interval. Few spermatocytes remained in the tubules at day 20. In comparison, the decrease of spermatogonia was more gradual. At the end of the experiment, the number of spermatogonia in each tubule was about one fourth of that detected at the time when the animals ceased to grow. It was thought that the sloughing and the disintegration of the spermatocytes and spermatids were major factors responsible for their rapid disappearance from the tubules, and that fast dividing and differentiating cells like spermatocytes and spermatids were more vulnerable to vitamin A deficiency than spermatogonia.

ISSN:1422-6405    

DOI:10.1159/000145007

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Ultrastructural study confirmed that, in rats, vitamin A deficiency initially caused the sloughing of some spermatids and spermatocytes into the lumina of the seminiferous tubules around day 3 following the initial decrease of body weight. From days 5 to 10, a considerable number of spermatocytes and spermatids, which still remained in the epithelium, underwent necrosis. Several stages of dying spermatocytes and abnormal spermatids were observed. The latter were distinguished by the presence of chromatin aggregating along the nuclear envelopes and highly vacuolated mitochondria. These cells range from single to multinucleate forms. They were incapable of differentiating further into spermatozoa and ultimately degenerated. Within the same period, Sertoli cells exhibited numerous darkly stained lysosome-like inclusions, and the upper part of their cytoplasm appeared as irregular processes, some of which were broken off and resulted in the thinning of the epithelium. From days 10 to 20, the remaining germ cells comprised mainly spermatogonia and few abnormal spermatocytes. The latter appeared enlarged and were very lightly stained. Their nuclei exhibited unusual blocks of heavily condensed chromatin amidst very highly dispersed chromatin fibers. Though their number was reduced, most of the spermatogonia appeared unaltered. Processes of Sertoli cells became even more irregular and were interrupted at certain sites by large empty spaces. Darkly stained inclusions in their cytoplasm were fewer than observed earlier.

ISSN:1422-6405    

DOI:10.1159/000145008

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The Champy-Maillet ZIO technique has been applied to the study of the muscular tunic of the stomach..In the corpus and antrum pyloricum some nerve fibres end in non-capsulated expansions owning thorn-like protrusions. Their morphology is studied and a possibly functional sensory significance is proposed, on the basis of previous experimental results.

ISSN:1422-6405    

DOI:10.1159/000145009

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The fine structure of granule-containing cells in the human superior cervical ganglion is described. These cells are larger than the typical SIF cells in mammals and exhibit green-yellow fluorescence. They are characterized by numerous granular vesicles (80–140 nm in diameter) in the cytoplasm, but have many features in common with ordinary ganglion cells. They emit several long processes which form bundles together with ordinary nerve fibers. No synapses are found where the cells are presynaptic, although a few synapses are observed there where nerves are presynaptic on the perikarya and processes of the cells. No close topographical relations are seen between the cells and blood vessels. It is suggested that the granule-containing cells are a special type of postganglionic aminergic neuron

ISSN:1422-6405    

DOI:10.1159/000145010

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The effect of an interruption of the yolk sac circulation on the rat visceral yolk sac and the development of the fetoplacental unit was examined in the last third of pregnancy. The yolk sac ischaemia was induced by ligating the blood vessels of the yolk sac stalk which connect the vitelline circulation with that of the fetus. A 3-hour ligature caused an extensive swelling of most cell organelles in the epithelial cells and in the capillary endothelia of the yolk sac. Other structural changes were indicative of a cessation of pinocytosis. A 6-hour ligature resulted in a common ncrease of cell swelling and in a beginning disintegration of the endothelial cells lining the vitelline capillaries. A 15-hour ligature caused severe ultrastructural cell lesions and macroscopical alterations suggestive of a progressive necrosis of the entire yolk sac tissue. Of special significance was the regular finding of a nearly complete loss of the amniotic fluid and the death of the fetus, although the maternal blood flow appeared to be still intact in the placenta.

ISSN:1422-6405    

DOI:10.1159/000145011

出版商:S. Karger AG    

年代:1979

数据来源: Karger