Archivio italiano di anatomia e di embriologia. Italian journal of anatomy and embryology最新文献

Previous investigations have ascertained, according to the results obtained by Bradley et al. (1980) in the sheep, that the laryngeal surface of the epiglottis of goat and bovine is always provided with numerous taste buds. These observations have verified in other ruminant species, as the moufflon and the buffalo, the validity of the above-named datum and have ascertained that it is always inconstant in the other animal species considered (wild boar, coypu). These taste buds show a typical structure (diameter of the outer taste pore varying from 2.7 to 4.2 micron, width of the chemoreceptors varying from 30 to 60 micron and length from 27.5 to 57.5 micron). Moreover, the normal structure of the above-named taste buds is also testified by the arrangement of their innervation and particularly by the integrity of the synaptic contacts. The results of the present research have permitted a critical and more severe examination of the probable functional role of those laryngeal receptors. In fact, in the ruminants they may protect the deep airways precluding to food particles the larynx in the phase of food regurgitation.

In the aim of bringing a contribution to role of the knee menisci and the functional connection between meniscal lesions and knee joint instability, four patients have been studied, who underwent arthroscopy for sub-acute tear of anterior cruciate ligament without clinical or morphological evidence of meniscal pathology. In these patients biopsies have been taken from one of the menisci and processed for the examination by the SEM. As control, meniscal fragments from two healthy knees have been studied from patients who underwent amputation at thigh for accidental trauma with irreparable lesion of femoral artery. In patients affected by ligamentous tear, on the meniscal surface a lot of deposited material appears, as well as many microlesions as clefts or cracking and distortion of superficial collagenous fibers. All described alteration are more evident in the central portion of menisci than in the anterior or posterior horns. The above mentioned patterns suggest a strong correlation of the knee instability due to ligamentous lesions and meniscal degenerative process which would onset before its clinical or macroscopical evidence.

Tissue location and biochemical aspects of the enolase, enzyme belonging to the glycolytic pathway, are presented. Embryological applications of the dimer gamma-gamma (Neuronal Specific Enolase) as a biological marker of the neuroectodermal derivatives is discussed. The authors stress the clinical importance of the NSE in the early detection of tumors.

The Authors investigate the morphology and the behaviour of the synaptic ribbons (NS) in the outer plexiform layer of the retina of the turtle Pseudemys scripta elegans during the 24 hrs cycle; the animals were subjected to a light-dark cycle = 12:12 hours. New ultrastructural features are demonstrated in the rod arciform density and in the fibers connecting the central axis of the ribbon with the presynaptic membrane (Figs. 1 A-B). As to chronobiological data, the existence of different kinds of ribbons, each typical of a single period of the 24 hrs cycle is excluded: identical NS can likewise be observed at different hours of the day and under various environmental light stimulations (Figs. 2-3-4). Furthermore, it is also demonstrated that during the light period, every rod synapse in the outer plexiform layer has a typical ultrastructural topography of its own (Figs. 5 A-B-C). During the dark period, the ribbon with its neighbouring vesicles moves towards the nucleus, thus leaving the synaptic region (Figs. 6 A-B-C). From the analysis of our results, we are of the opinion that all previously demonstrated changes in number are only in part dependent on cyclic disruption and reconstruction. On the contrary, they can be the result of a different topographical arrangement of the organelles. When NS modify their relationship with the presynaptic membrane of the rods, they may behave as switch on the nervous circuits of the retina and play a facilitatory or inhibitory role on the discharge of synaptic vesicles during the different periods of the 24 hrs cycle.

The pattern of cytidylate and uridylate phosphatase, uridine phosphorylase, cytidine and cytosine deaminase activities has been studied in M. complexus during chick development. The comparison of these enzyme activities with thigh muscles ones has shown that quantitative and temporal changes occur, in parallel with the unusual pre-natal and early post-natal development of M. complexus. The results suggest that during the first period of incubation, UMP might follow the anabolic pathway UMP-UTP, which leads to cytidine nucleotides, while approaching the hatching, the catabolic pathway should prevail. In addition, immediately after hatching, pyrimidine metabolism is especially supported by cytidine nucleotides.

The intimal synovial surface in normal conditions, using a scanning electron microscope, has been studied. The three synovial membrane types are clearly recognizable: fibrous (Fig. 8), adipose (Figs. 9 and 10) and areolar (Figs. 1 and 2); but only in the areolar type, the characterization of the main two cellular types: synoviocytes B and A, is possible. Synoviocyte B represents the constitutive element which characterizes the synovial intima; it has a cellular body of irregular shape and long cytoplasmic processes directed towards the joint cavity (Figs. 3, 4 and 5). The cellular body and the cytoplasmic processes are covered by small blebs (Fig. 6). and similar vesicles, probably of the same cellular origin, are scattered throughout the extracellular matrix. These cells are likely responsible for the specific structure of the interstitial tissue adapted to the exchanges and to the regulation of the composition of the synovial fluid (Okada et. al. 1981; Linck and Porte, 1978, 1981). Synoviocyte A is a small minority; it has many long and irregular membrane infoldings which define a complicated system of intracellular canaliculi of various depth (Fig. 7). The ultrastructural characteristics of their surface and the peculiarity of their organelle apparatus, described by other AA. (Fell et. al., 1976), demonstrate that these elements carry out a macrophagic function. The clear majority of the synoviocytes B in the intimal surface suggests that in normal conditions, the synthesizing processes prevail over the phagocytosis ones.

Thrombocytes of Torpedo marmorata Risso and Scyliorhynus stellaris L. (Elasmobranchs) are multiform from rounded to spindle-shaped. They originate in the spleen from prothrombocytes. They appear to be functionally correspondent to mammalian platelets because they form aggregates and adhere to glass and contain the same surface-connected canalicular system (SCCS) as in platelets, as proved by tannic acid treatment. Immunocytochemical staining have demonstrated, moreover, the presence in their cytoplasm of three platelet factors: platelet factor 4, beta-thromboglobulin and factor VIII related antigen. Stimulating agent, like collagen, ADP, noradrenaline, 5-hydroxytriptamine and thrombin induce aggregation of thrombocytes and the empting of their granules and vesicles containing very likely the platelet factors. The above observations leave few doubts on the functional equivalence of elasmobranch thrombocytes to mammalian platelets.

The present study demonstrates that a consistent percentage (over 30%) of freshly isolated human Langerhans cells express the CD23 moiety. This was achieved employing a pre-embedding immunoelectronmicroscopy, using the peroxidase reaction product as a marker, assay on suspended trypsinized epidermal cells isolated from normal human skin. The possibility that the CD23 molecule on the surface of Langerhans cells could play a role in the antigen-presentation function of dendritic epidermal cells to T lymphocytes is proposed.

The glycosaminoglycans of the human bone are Chondroitin-4 sulfate, Chondroitin-6 sulfate and Keratosulfate. Their quantity presents variations with ageing. The Keratosulfate shows a prevalent localisation in the bone matrix just around the osteocytes.

Anatomical variation of the nervus abducens in human encephali were found and described. They consisted of (1) an unusual trifurcation of the abducent nerve, limited to the extradural portion of the neural trunk (1.4% of the cases) and (2) the duplicity (11.1%) of the neural trunk, starting before reaching the orbit and ending before reaching the m. rectus lateralis. The possibility of correlating these variations with clinical aspects and forensic interpretations is mentioned.