Zeitschrift fur mikroskopisch-anatomische Forschung最新文献

The intercellular substance of the pulp of fully erupted, healthy, human permanent premolar teeth was studied by light microscopy. Histological and histochemical methods were applied to sections from whole, decalcified teeth and isolated, undecalcified pulps, fixed with phosphate-buffered formalin and embedded in paraplast. Fibres were mainly collagen; they formed a meshwork progressively more dense from the crown to the root apex; in the crown the fibre meshwork was denser at the periphery than in the center of the pulp. Coarse bundles of collagen fibres were found in the apical part of the pulp of about one every third teeth. Glycoproteins, recognized thanks to their P.A.S. positivity, were abundant in the basal membranes of vessels and nerve fibres and between odontoblasts, but scarce in the remaining pulp tissue. Glycosaminoglycans, recognized thanks to their alcianophilia, were more abundant in the vessel wall and in the areas with coarse bundles of collagen fibres than elsewhere in the pulp; also, they were more abundant at the periphery than in the center of the pulp. As judged by staining with alcian blue at critical electrolyte concentration, glycosaminoglycans were mostly hyaluronate, with low amounts of condroitinsulphate and dermatansulphate; some heparansulphate or keratansulphate was present only in the regions with coarse bundles of collagen fibres. The morphological and histochemical differences found among different regions of each pulp and among different pulps as well provide a basis to recognize and interpret inter-regional and inter-individual variations in the pulp response to physiological and pathological modifications affecting the hard tissues of the teeth.

The presence of some cytoskeletal proteins related to the intermediate filaments glial fibrillary acidic protein -GFAP and vimentin) and S-100 protein has been investigated in sensory formations of the glabrous skin of the rat. A positive reaction both for S-100 protein and vimentin was found in the inner core and related cells of glomerular and simple sensory corpuscles; in contrast, no positive reaction was shown for GFAP. The authors discuss these results on the basis of the glial origin of the inner core and related cells in sensory formations.

In the present pilot study, the human thyroid gland tissue was cultivated under continuous culture conditions in the culture chambers of the ACUSYST-S system to determine morphological changes as well as the secretion of thyreoglobulin (Tgl) and thyroid hormones. After 24 hours of cultivation the follicular structure of the tissue was preserved in peripheral parts only, and there were regressive changes in the epithelium center. After 72 hours the regressive changes appeared in isolated follicles only; the size of the follicles increased, the height of the follicular epithelium decreased and there were macrophages present with phagocytized cell debris. After 144 hours disintegration of epithelia took place in the centre, while at the periphery the original follicles survived and very tiny new follicles formed, consisting of only 6 to 8 cells each and surrounding in section the homogeneous colloid. The parenchyma picture suggests a possibility of functional regeneration as an expression of adaptation to the conditions newly arisen during cultivation in a culture chamber. There was no significant influencing of the thyroid hormone secretion during cultivation. On the other hand, the Tgl secretion decreased throughout cultivation.

Two types of medium to large sized neurons are present in the granular layer of the mouse cerebellum. One type has a large nucleus with a prominent nucleolus and a moderate amount of cytoplasm containing Nissl substance. This type corresponds to the classical Golgi II neuron. The second type has a much smaller nucleus (mean diameter 8.4 microns) with a darkly staining nuclear envelope which is almost invariably deeply indented by cytoplasmic intrusions. The nucleolus is smaller and less conspicuous than in Golgi II neurons. These neurons are identical to the pale cells described by Altman and Bayer (1977). The numbers of both types of neuron were estimated in the spinocerebellum, lobus simplex and nodulus in mice aged 6, 15, 22, 25, 28 and 31 months. There was no significant variation in the number of either Golgi II neurons or pale cells with age in any part of the cerebellum. The number of Golgi II neurons per mm3 was similar in all parts of the cerebellum (mean 3560 mm3). This was identical to the mean number of pale cells per mm3 in the spinocerebellum and pontocerebellum but in the nodulus pale cells were much more numerous (mean 41,170 per mm3). It is postulated that pale cells are small Golgi II neurons.

Embryos at morula stage were ultrastructurally examined. Blastomeres of normal embryos are characterized by the presence of ribosomes, short single and branched cisterns of endoplasmic reticulum, small spherical mitochondria and vacuolar-granular structures. An enhanced autophagy and the presence of numerous and large lipid droplets are signs of the beginning degeneration.

The use of the monoclonal anti-cytokeratin 6 and 18 antibody Dako CK 1 revealed a marked positivity of reticulo-epithelial cells (REp). Aspecific esterase testing, light microscopy, and electron microscopy were used in order to obtain a comparison between the morphology of the lymphoid follicle medulla and the picture obtained by using the monoclonal antibody CK 1. Results showed that the bursal follicle medulla can be divided into 2 areas: an esterase-positive, cytokeratin-negative centre-medulla, and a more peripheral cytokeratin-positive, esterase-negative area. These 2 regions appear to be separated by a boundary composed of flattened REp cells. Desmosomes were also observed not only among their processes, but also between the latter and the side of the cortico-medullar boundary epithelium which is external with respect to the basal membrane.

Epon sections from glutaraldehyde-fixed rat bone marrow were treated with aqueous solutions of the following electron contrasting agents: uranyl acetate, ruthenium red, potassium permanganate, potassium dichromate, stannous chloride, palladium (II) chloride, sodium molybdate, phosphomolybdic acid, molybdenum heteropolyblue, phosphotungstic acid, iron(II)-phenanthroline, aluminium-hematoxylin, mercurochrome, cuprolinic blue, and sirius light turquoise blue. At the ultrastructural level, a high degree of electron opacity was always observed in mast cell granules and the crystalline inclusion (internum) of eosinophil granules. The chromatin revealed a somewhat lower and variable contrasting reaction, while the matrix (externum) of eosinophil granules appeared with scarce or no contrast. This pattern of electron opacity showed no correlation with the type of agent used; therefore, it can be assumed that binding processes based on the own chemical reactivity of the compounds are rather of secondary importance. The differential epoxy resin embedding of cell structures and the variable access of aqueous reagents through the non-polar plastic could be the predominant factors which account for these contrasting reactions.

The morphological changes of the tectorial membrane (TM) during the postnatal development (0, 3, 6, 12 and 25 day old) of the organ of Corti were studied by light microscopy in 20 control and hypothyroid rats. Hypothyroidism was induced by daily administration of propylthioruracil (PTU) until the end of lactation. The auditive receptor in the cochlea of the hypothyroid animals shows serious structural alterations compared with those of normal ones: abnormal persistence of Kölliker's organ, immaturity of sensory cells and supporting cells and a specific distortion of the TM. Differences with controls were first observed on the sixth postnatal day of the hypothyroid rats. The inner spiral sulcus was not shaped and the TM was attached to the Kölliker's organ. In older stages (12 and 25 days), Kölliker's organ was still present. The TM acquired a shap hump with an abnormal fibrillar arrangement in its middle part. It was still attached to the outer supporting cells by a remnant of the marginal net. It was suggested that the TM is secreted by the inner spiral limbus and Kölliker's organ. An abnormal persistence of these structures in the hypothyroidism results in a retardation of Corti's organ development. However, this conclusion does not explain the absence of the outer portion of the TM. Our study confirms the hypothesis that the secretion of any components of the marginal zone of TM is made by outer supporting cells which in PTU-treated animals appear very immature and with hypoplasia.

Five quinolone (ofloxacin, cinoxacin, enoxacin, ciprofloxacin, oxolinic acid) and one non-quinolone (coumermycin A1) inhibitors of prokaryotic DNA gyrase used in clinical practice for treatment of bacterial infections were experimentally examinated. As model organism the flagellate Euglena gracilis was used. Ultrastructural changes in chloroplasts and mitochondria caused by inhibitors were quantitavely evaluated. Simultaneously in all cases injury and hereditary loss of chloroplasts (bleaching) were observed in the cells. In some samples about 45% of cup-shaped mitochondria cumulated in the cytoplasm. In damaged mitochondria some degenerative signs were seen, but after the last subcultivation on drug-free media the number of injured mitochondria in the bleached cells yielded to the normal value.

Using the electronograms of Pacinian corpuscle capsule of the cat mesentery the authors have studied in details the structure of its layers and lamellae. The thickness of the capsule lamellae ranged between 30 nm-320 nm, the mean width being 150 nm. On the surface they are overlaid by means of lamina basalis. The capsule is formed by circular layers composed, most often, by 1-2 lamellae, less frequently, by larger number of lamellae. The width of the space between the layers of lamellae is 150-820 nm. A number of lamellae is provided with longer or shorter processes. They are directed more often to the adjacent lamella with which they can be also connected by means of membrane specialization. However, they are also directed into the space between individual layers of the capsule. The importance of these processes has not been known. Furthermore, the authors have studied the reciprocal link-up of the lamellae within one layer. The lamellae are connected either side-to-side, by inserting the end of one lamella into the infolding of the other, end-to-side or end-to-end. Rich pinocytotic activity (rich occurrence of caveolae) was observed in the lamellae of the capsule. Therefore the authors are of the opinion that the capsule and its lamellae have not only mechanical significance or the function of the transfer system and filter, but they form an important component (subsystem) of the whole metabolic system in the sensory corpuscle.