摘要:

The cells present in the alimentary canal, contacting both nerve endings and smooth muscle cells and named interstitial cells of Cajal, show different ultrastructural features. A comparative study has been performed in order to see if these differences can be related to the animal species studied or to the interstitial cell localizations inside the muscle wall of the various levels of the alimentary canal or to their contacts with other cells. Only mammals were considered, and rat, mouse, hedgehog and man have been studied. All the localizations where interstitial cells of Cajal have usually been found were considered: esophagus (body and lower sphincter), stomach (gastric extent of the lower esophageal sphincter, fundus and corpus) small intestine and colon. From this comparison a correlation was found between the morphology and the location of interstitial cells. On the contrary, the morphological differences existing between animal species do not seem to be that consistent. Moreover, the number of contacts between interstitial cells and between these and smooth muscle cells and nerve endings varies according to the interstitial cell location and morphology. It is concluded that the chain nerve endings → interstitial cells of Cajal → smooth muscle cells is not morphologically identical at each gastrointestinal level, and this finding is considered very important in interpreting the role played by the interstitial cells of Cajal in gastrointestinal motil

ISSN:1422-6405    

DOI:10.1159/000146433

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Scanning electron microscopy of corrosion casts was used to study the ultrastructural morphology of the microcirculation in the feline kidney. The technique used enabled us to examine the renal microvasculature by obtaining stable and consistent replicas of the vasculature. Corrosion casts were evaluated at three different levels, namely subcapsular, midcortical and the corticomedullary junction. The interlobular arteries, given off by the arcuate arteries, coursed through the cortex in a radial fashion and afferent arterioles were given off at varying intervals. Large afferent arterioles formed the glomerular capillary lobules which consisted of very tortuous capillaries. Smaller-diameter efferent arterioles were formed at the vascular pole and ran in the opposite direction to the afferent arteriole. The peritubular plexuses were seen as interconnecting capillaries at both the subcapsular, midcortical and corticomedullary junction. Numerous efferent arterioles, derived from the corticomedullary glomeruli, were seen as large, radiating vessels running towards the renal papilla.

ISSN:1422-6405    

DOI:10.1159/000146434

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

With the aid of a relatively simple computer system three-dimensional graphic reconstruction models have been prepared.The procedure was applied in anatomy on a fixed embryonic specimen and in radiology on living subjects by using computed tomography scans.The results are useful for embryological research as well as for clinical evaluation.

ISSN:1422-6405    

DOI:10.1159/000146435

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Cystic endometrial hyperplasia (CEH) is a uterine disorder characterized by the formation of large numbers of cysts in the endometrium. The purpose of this study was to examine and characterize cell types in the endometrium associated with the cysts and uterine glands. No apparent histological differences between CEH-involved and normal uterine columnar epithelium were found. Endometrial glands in CEH-involved and normal uteri were lined with simple or ciliated columnar epithelial cells and surrounded by lamellar connective tissue.The cyst epithelium appeared to be stretched obliquely and compressed so that both the cells and nuclei were horizontally oriented relative to the cyst lumen and were surrounded by lamellar connective tissue. Electron microgaphs revealed an abnormally high number of mitochondria in the cystic cells as compared to normal glandular cells. In conclusion, CEH is characterized by the formation of cysts which develop from the uterine glandular tissue. Epithelial cells lining the glands appeared to be distorted, possibly in response to internal pressure from increased volume due to high metabolic activity, and/or no uterine luminal opening.

ISSN:1422-6405    

DOI:10.1159/000146436

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Neuronal characteristics and location of the neurosecretory, magnocellular, fuchsin-paraldehyde-posi-tive (FA+) system of the fowl are described at the light-microscopic level on serial semithin sections. Three nuclei make up this system, the nucleus supraopticus, n. magnocellularis interstitialis and n. paraventricularis. These nuclei display magnocellular neurons, not showing a parvocellular component. The neurons of the three nuclei showed a scattered pattern of distribution and a dense surrounding neuropil. Groups formed by magnocellular neurons were found in the three nuclei and groups formed by one magnocellular and a parvocellular neurons were only found in the n. magnocellularis interstitialis and in the n. paraventricularis.The presence of neurons in apposition to blood vessels was frequent in the magnocellular FA+ system of the domestic fowl.

ISSN:1422-6405    

DOI:10.1159/000146437

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The rete testis of the goat can be divided into three parts, septal, mediastinal and extratesticular. The septal rete is short, relatively straight and connects the terminal part of the seminiferous tubules with the mediastinal rete. The mediastinal rete is a labyrinth of intercommunicating channels that occupies about two-thirds of the central axis of the testis. The extratesticular rete is located outside the testis at its extremitas capitata and forms sac-like dilations up to 2 mm in diameter. The rete testis, regardless of its location, is lined by simple cuboidal to simple squamous epithelium that invariably contains a few intra-epithelial lymphocytes and macrophages.The epithelial cells possess few microvilli and a centrally located flagellum at the luminal border. With the exception of a few small vesicles in the apical cytoplasm, morphological features associated with absorption such as coated vesicles, canaliculi, vacuoles and multivesicular bodies are absent. However, basolateral interdigitations between adjacent cells, another feature of absorptive epithelium, are frequently noticed. Most cytoplasmic organelles except mitochondria and free ribosomes are poorly developed, suggesting that caprine rete epithelial cells are not associated with protein/glycoprotein secretion. There is no evidence of sperm phagocytosis by the rete epithelium, but luminal macrophages containing sperm fragments are occasionally encountered.The structural-functional relationships of the rete epithelial cells are discussed.

ISSN:1422-6405    

DOI:10.1159/000146438

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The chronological appearance of PP cells in fetal pancreatic islets was studied using specific anti-PP serum and the direct peroxidase method. The presence of A and B cells was also studied, using the same immunocytochemical technique, as a reference pattern related to data previously reported. Our data confirm that the A cell is the earliest endocrine cell type, appearing on the 12th day of gestation, followed by B cells (14th day) and later on by PP cells (19th day). Primitive islets were identified in the pancreas after the 15th day. However, the spatial cell disposition observed in the adult islet was only recognized at the 20th day of gestation. The data reported provide the necessary information to establish the complete chronology in the rat fetus. Consequently, the development of pancreatic islets in the rat fetus could be employed as a useful model to study the existence of factors that control the sequential appearance of endocrine cells and the possible changes occurring in the islets of animals with genetic diabetes during the fetal period.

ISSN:1422-6405    

DOI:10.1159/000146439

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Cerebral forebrain arterioles and neuropil were analyzed histochemically to determine the effects of halothane anesthesia on key enzymes of aerobic and anaerobic metabolism, as well as the hexose monophosphate shunt in rats. Significant changes were noted in all five enzymes examined in arterioles, while no changes were observed in the two enzymes involved in aerobic metabolism in the neuropil. Our data suggest that surgical anesthetic levels of halothane can impair forebrain metabolism and lead to altered electrophysiological responses.

ISSN:1422-6405    

DOI:10.1159/000146440

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Various nerves of 6 representative species of mammals (including the human) were studied by the comparative association of the selective staining methods of light microscopy with the ultrastructural observation after tannic acid-glutaraldehyde fixation, which provided a reliable means of characterizing the different elastic system fibers. Although mature elastic fibers are not present in nerves, elastic-related fibers are frequently observed: oxytalan fibers are found mainly in the endoneurium, whereas elaunin fibers predominate in the epineurium. These fibers are longitudinally disposed, in a parallel orientation to the axons. The fact that these findings were consistently observed in the nerves of all species studied argues strongly in favor of the existence of a uniform structural pattern of distribution of elastic system fibers in nerves as a general phenomenon in mammals.

ISSN:1422-6405    

DOI:10.1159/000146441

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

A unique opportunity presented itself for a morphologic study of experimental unilateral acute renal failure (ARF) in male rats. The ARF had been induced in the rats by temporary occlusion (1 h) of the left renal artery. Twenty-nine rats were divided into subsets as follows: 2–3 h, 24 h, 1 week, 2, 4, 8, and 12 weeks following release of occlusion. Microdissection showed a heterogeneous population of abnormally structured proximal tubules in which the regressive lesions of tubular necrosis were combined with the progressive reaction of repair. The lesions demonstrated are reminiscent of those which have been described in ARFin the human and in experimental animals. Many proximal tubules in the 2- to 3-hour subset presented 1–3 disruptive lesions (DLs) while greater numbers of proximal tubules from the 24-hour group presented 1–5 DLs. Many proximal tubules presented no DLs, but nearly all from the 24-hour subset (97–100%) displayed a squamate appearance which paralleled and was caused by acute tubular necrosis. At 1 week, a dilated pars recta was common, but by this time, the squamate pattern had disappeared. Many casts were present. At 2 weeks, many fewer casts were present in proximal tubules and none were seen at 4, 8 or 12 weeks. The nephrons, particularly the proximal tubules, presented a variety of structural alterations at 2, 4, 8 and 12 weeks. Changes of special interest include (1) the presence of swan-necks; (2) a distinctive squamate appearance of the proximal tubules in the animals killed at 24 h; (3) a spiral, curled appearance caused by differential hyperplasia in animals at 4, 8 and 12 weeks, and (4) a tendency for ischemic lesions to involve all layers of the renal cortex.

ISSN:1422-6405    

DOI:10.1159/000146442

出版商:S. Karger AG    

年代:1987

数据来源: Karger