In the region of the base of the intestinal crypts undifferentiated goblet cells display a configuration and constellation of organelles and membrane structures that are indicative of their importance for function. These images at this stage of development deliver a scenario of the mechanism of secretory granule production: aggregates of protein vesicles from the "transitional elements" (PALADE) of the granular endoplasmic reticulum are, so to speak, rolled up on the trans side of the Golgi apparatus by inversion of peripheral membrane segments of the innermost Golgi lamellae, thereby forming corpuscles. The origin of the capsulated vacuoles, which contain vesicles as single elements or as conglomerates, is well established. Their capsule consists of a trilaminar external and external and internal membrane; between them lies condensed material of the Golgi apparatus. In the opinion of the present author, the development of the ensheathed vacuoles represents a basic, more general mechanism. In contrast, the further steps of synthesis, for the formation of secretory granules, are more heterogeneous. Condensation of the vesicles and the inner capsular membrane results in the formation of a prosecretory granule, which in the basic element in the process of secretory granule production. The prosecretory granules develop singly or by fusion with other granules to give primary secretory granules. The complexity of this mechanism of secretory granule formation, however, becomes evident when considering the apposition of capsulated vacuoles and prosecretory--primary--secondary secretory granules, of prosecretory and primary secretory granules as well as prosecretory granules and secondary secretory granules. Generally, primary granules show a tendency to become secondary secretory granules or to fuse with them. During maturation of the goblet cells the secretory granules fuse to form larger mucous bodies in the theca by fusion of the laminae of the membranes; a final product, there is a homogeneous mucous mass devoid of membranes.
The ultrastructural features of the encephalic dura mater-arachnoid borderline (interface) layer (zone) of rats, rabbits, cats and humans were studied. The rat's interface zone included the electron-lucent epithelium-like arranged fibroblasts of the inner dural layer, the rich in filaments cells of the dural neurothelium, a 20 nm wide intercellular cleft filled with electron-dense material and the dark mitochondria-rich cells of the outer arachnoidal layer; in rabbits and cats, this laminar distinction was less prominent, while in man, it was almost absent.
The quantity and type of proteinpolysaccharide complexes in the matrix determine up to a great extent the mechanical properties of articular cartilage. It is the purpose of this study to evaluate the changes in the mentioned matrix components against the background of experimentally induced osteoarthrosis. As shown by electron microscopic and morphometric studies, the changes in the superficial layer are promptly occurring and clearcut, whereas those in the deep layers are recorded in late observation terms only. A reduction of proteoglycan quantity is noted with a simultaneous differentiation of their fine structure in the various stages of osteoarthrosis development. Initially the alteration in the cell organization of chondroblasts is associated with occurrence of differences in proteoglycan content, and subsequently--in the collagen structures of the matrix too.
Ultrastructure of the chromatoid body in rat spermatocytes and spermatids was studied by transmission electron microscopy. The following was found: 1. electron dense granules, 72.1 +/- 14.73 (SD) nm, that appeared to be both primary (assembling) and end (disassembling) structural subunits in the biogenesis of the chromatoid body, 2. relationship between chromatoid body and cytoplasmic microtubules, 3. ribbon-like structures and aggregates of 25 nm granules. The discussion focuses on a) a probable sequence of formation and breakdown of the chromatoid body, and b) the chromatoid body as an example of a common cellular design involving an interrelationship of dense material-smooth membranes-microtubules.
The telencephalic proliferative response has been studied in adult newts after lesion on the central nervous system. Both in the animals injured on the optic tectum and in those on the telencephalon a telencephalic proliferative response was observed, localized in the dorsal pallial areas and in the striatum. Quantitative analysis of the proliferative activity of the matrix cells present in the telencephalon showed a different response pattern. In the animals lesioned on the telencephalon the labelled cells are much more numerous in the injured hemisphere than in the healthy one and these cells persists at a high level even in the specimens fixed 90 days after the lesion. In this case no labelled cells are observed in the midbrain. The number of labelled cells in the animals lesioned on the optic tectum was identical in both telencephalic hemispheres; this number decreases from 15 to 30 days after the injury and at 90 days labelled cells are not observed. These data confirm the presence of a neuronotrophic factor released in the ependymal fluid and active on the telencephalic periventricular matrix cells but not on the undifferentiated cells of the grey layers of the optic tectum. It is also assumed that the proliferation of matrix cells of an injured area causes the formation of glial cells and neurons, such proliferation in an intact zone is oriented to differentiation of glial cells alone.
This paper describes observations of the normal and irritatingly changed morphology of the human peritoneum and about alterations in human peritonitis. The results were obtained by transmission- and scanning electron microscopy, immunohistochemical reactions, and other supplementary light microscopic investigations on surgically collected tissue material. Special attention was given to the superficial structure and the openings of the peritoneum. The superficial liquid film and the microvilli of the mesothelium are influenced by irritative conditions. In the human peritoneum, there are separated areas of small high and of large flat mesothelial cells. The small-cell areas of the peritoneum are connected with openings, special mesothelial cell glades, and cell migrations from deeper parts. There are signs of mesothelial secretion into the peritoneal cavity from mesothelial cells and intercellular spaces of the mesothelium too. The stomata - openings of the peritoneum - are of conditioned character. These depends upon the state of the superficial mesothelium and upon topical loci between the mesothelial cells. Special attention requires the so-called Dreierpunkt. In peritonitis, there are also openings in the fibrin layer. On this condition, the superficial layer of mesothelium mostly becomes destroyed. The keratin reaction is the most essential among the immunohistochemical investigations. It allows to demonstrate preserved mesothelial cells in the deepness of inflammatory tissue in peritonitis. In healing peritonitis, the surface of the peritoneum is marked by special elongated cells, but they are without any keratin reaction. It seems that the forming of a neomesothelium is connected with mesothelial cells preserved by fibrin and the elongated cells mentioned above.
In the region of the base of the intestinal crypts undifferentiated goblet cells display a configuration and constellation of organells and membrane structures that are indicative of their importance for function. These images at this stage of development deliver a scenario of the mechanism of secretory granule production: aggregates of protein vesicles from the "transitional elements" (PALADE) of the granular endoplasmic reticulum are, so to speak, rolled up on the trans side of the Golgi apparatus by inversion of peripheral membrane segments of the innermost Golgi lamellae, thereby forming corpuscles. The origin of the capsulated vacuoles, which contain vesicles as single elements or as conglomerates, is well established. Their capsule consists of a trilaminar external and internal membrane; between them lies condensed material of the Golgi apparatus. In the opinion of the present author, the development of the ensheathed vacuoles represents a basic, more general mechanism. In contrast, the further steps of synthesis, for the formation of secretory granules, are more heterogeneous. Condensation of the vesicles and the inner capsular membrane results in the formation of a prosecretory granule, which in the basic element in the process of secretory granule production. The prosecretory granules develop singly or by fusion with other granules to give primary secretory granules. The complexity of this mechanism of secretory granule formation, however, becomes evident when considering the apposition of capsulated vacuoles and prosecretory - primary - secondary secretory granules, of prosecretory and primary secretory granules as well as prosecretory granules and secondary secretory granules. Generally, primary granules show a tendency to become secondary secretory granules or to fuse with them. During maturation of the goblet cells the secretory granules fuse to form larger mucous bodies in the theca by fusion of the laminae of the membranes; a final product, there is a homogeneous mucous mass devoid of membranes.
The function of pituitary STH- and PRL-cells was studied under treatment of bromocriptin and haloperidol in 6-day old house cats. After histological staining, the intensity of the intracellular reaction was determineded by a microphotometric technique. Additionally, the STH and PRL blood levels were measured by radioimmunoassays.
The different cell types in the salivary glands of Eobania vermiculata have been investigated by light and electron microscope. This study has particularly been focused on the serous cells. We have found three distinct cell types occurring in the glands: basophilic, alveolar and cystic cells, the first considered as early stage in the development of the others. Moreover, granular cells have ben regarded as a separate secretory type, not only on the basis of their morphological features, but also because they appeared in close connection with the lumen of the vessels, where they seem to discharge their secretum.
A survey of the taste buds of 26 species of teleost fish by electron microscopy was undertaken in order to establish the range of variation and to test conflicting functional interpretations. It is concluded that only one type of cell acts as a gustatory receptor, the second form of elongated cell is secretory and supportive in function. The "light/dark" nomenclature for the elongated cells has proved misleading and should be abandoned. Direct, synapse-like, cell to cell communication in taste buds is not established. Gustatory synapses are not necessarily associated with vesicles in the sensory cell. A basal cell is not invariably present in external taste buds, none was found in gadid and some other species although present in their oral taste buds. Basal cells resemble Merkel cells in having microvilli and a nerve association, but the details of the cytology, including the synaptic specializations, are different. Sub-membrane cisternae in gustatory cells, contiguous to nerve profiles, occur, but the evidence is insufficient to conclude that these mark efferent synapses. In two instances, synaptic specializations linked a single nerve fibre profile to both a basal cell and a gustatory cell, suggesting the existence of regulatory mechanisms within the bud.
The ultrastructure and cytochemistry of the distal border of the olfactory epithelium was investigated in the Mediterranean tortoise Testudo hermanni (Gmelin). The olfactory knobs of typical bipolar receptor cells, provided with microvilli and cilia, were found to contain a partly reduced set of axonemal and kinetosomal structures. Dynein arms and radial spokes were never observed in the cilia; as a rule, basal bodies in the knob cytoplasm lacked feet, and residual striated rootlets were found deep inside the dendrite. A dense feltwork of thin filaments coated the basal portions of both olfactory microvilli and cilia as well as the free surface of the knob: this is a thick glycocalix, as suggested by ruthenium red (RR) staining. A complex pattern of rounded and elongated vesicular profiles (labyrinth), which accumulated beneath the apical plasma membrane, was also observed in the knobs. Although these vesicles were closely contiguous to the plasmalemma and related caveolar invaginations (impocketings), findings from RR staining excluded any permanent connection between the external environ and labyrinth compartment.The degeneration patterns of kinetic specializations and the remarkable glycocalix of the olfactory cell surface exposed to the external environ are discussed in relation to the hypothesis that odorant molecules interact with stereospecific sites in the plasma membranes. It is assumed that kinetosomal and axonemal structures are conservative features of the ciliated cells ancestral to the bipolar receptor cells, whilst the thick RR positive coat possibly represents a specialization relevant to the selection of molecules, before these interact with the plasma membrane. Finally, the vesicular profiles contained in the knob cytoplasm are related to the turn-over processes involving the apical plasmalemma: they could represent newly formed membranous complements from the Golgi bodies or old patches of plasmalemma which will undergo intracytoplasmic autolysis processes.
The skin of Bombina variegata variegata was studied by histochemical and immuno-histochemical reactions in order to identify the production of active substances (5-HT and bombesin) from the two different kinds of glands (with small and large granules) present in the skin of this subspecies. On the basis of the obtained results, the glands with large granules appear to be involved in bombesin synthesis; on the contrary the glands with small granules seem to be the main cell producing of 5-HT.
In this paper we describe the effects of endurance training and of prolonged exposition to the anaesthetic ethelene glycol monophenyl ether, on the neuromuscular system in a teleost fish, as seen by quantitative enzyme-histochemistry. Measurements of Phosphofructokinase (PFK), Succinate dehydrogenase (SDH) and Nicotinamide adenine dinucleotide diaphorase (NADH-d) activities were carried out on the myotomal musculature, and the spinal lateral neuropil, which includes motoneuron dendrites. In spinal motoneuron somata, identified with the fluorescent tracer Fluorogold, we measured SDH and NADH-d activities.Endurance training for 12 weeks at 3-4 body lengths per second induces increases in PFK, SDH and NADH-d activities in the lateral neuropil and in slow, fast and intermediate muscle. Intermediate muscle shows the greatest adaptive potency. We were unable to detect changes in enzyme activities in the motoneuron somata of trained fish.Exposition to the anaesthetic for a period up to 8 weeks affects temporaly the SDH activity in white muscle, PFK and NADH-d activities were not changed in white muscle. However, PFK, SDH and NADH-d activities were decreased in the neuropil, and SDH and NADH-d activities were decreased in motoneuron somata. These changes were interpreted as depression effects on overall metabolic activity.
Male cloacal glands of Salamandrina terdigitata were studied under the light and scanning electron microscopes. Beside the three accesory glands usually described in the cloacal region of most Salamandridae: dorsal, ventral and pelvic, the study revealed a further glandular cluster corresponding to Kingsbury's glands. Kingsbury's glands have been reported in some Plethodontidae, Ambystomatidae and Dicamptodontidae but have never observed before in Salamandridae. The authors also report the presence of Kingsbury's glands in the male cloacal region of a further salamandrid: Triturus cristatus carnifex, which was examined for comparison. The glands are described on the basis of their anatomical position and cytological and staining characteristics. Examination of specimens of Salamandrina terdigitata sacrified at different times of the year showed that cloacal glands are generally engaged in secretory activity from late summer to spring, which coincides with the occurrence of abundant sperm in the pasa deferentia. This finding supports the hypothesis of a prolonged breeding season in this species. The morphology and functional role of the four glandular categories are also reviewed in the light of the abundant literature on the subject.
