Search results for "Histology"
showing 10 items of 985 documents
Evagination of Cells Controls Bio-Silica Formation and Maturation during Spicule Formation in Sponges
2011
The enzymatic-silicatein mediated formation of the skeletal elements, the spicules of siliceous sponges starts intracellularly and is completed extracellularly. With Suberites domuncula we show that the axial growth of the spicules proceeds in three phases: (I) formation of an axial canal; (II) evagination of a cell process into the axial canal, and (III) assembly of the axial filament composed of silicatein. During these phases the core part of the spicule is synthesized. Silicatein and its substrate silicate are stored in silicasomes, found both inside and outside of the cellular extension within the axial canal, as well as all around the spicule. The membranes of the silicasomes are inte…
Physical Fitness Evaluation of School Children in Southern Italy: A Cross Sectional Evaluation
2018
The aim of this work was to evaluate the fitness levels of different physical components in schoolchildren in southern Italy and identify age-related effects of physical performance. One hundred and fifty-four schoolchildren with ages ranging between 6 and 10 years (age 8.1 ± 1.45 years; 33.70 ± 10.25 kg; 131.50 ± 13.60 cm) were recruited for the investigation. Each scholar underwent a fitness-test battery composed of five elements. A Hand-Grip Strength Test to assess the strength of the hand muscles, a Standing Broad Jump Test to assess lower body explosive strength, a Sit-Up Test to exhaustion to evaluate abdominal muscular endurance, a 4 × 10-m Shuttle Run Test to assess agility, and a 2…
Noninvasive Flap Preconditioning by Foam-Mediated External Suction Improves the Survival of Fasciocutaneous Axial-Pattern Flaps in a Type 2 Diabetic …
2018
Background Advances in reconstructive surgery are leading to an increased number of flaps at risk for ischemic necrosis, because of either intrinsic (e.g., larger flap size) or extrinsic (e.g., diabetes) factors. Methods to preoperatively improve flap vascularity and limit postoperative ischemia are lacking. Noninvasive suction, using either a macrodeformational silicone cup interface (external volume expansion) or a microdeformational polyurethane foam interface (foam-mediated external volume expansion), has been shown to induce angiogenesis in tissues. The authors investigated whether the preoperative use of external volume expansion/foam-mediated external volume expansion improves flap s…
Near‐field optical addressing of single molecules in coplanar geometry: a theoretical study
2001
Photonic transfer through elongated optical structures of submicrometre section microfabricated at the surface of dielectric or semiconductor samples can be enhanced by an appropriate structuring of the local refraction index. We show from computerized simulations that both the light localization and the spectroscopic properties of such structures can be used to selectively excite, in coplanar geometry, individuals molecules located in the near-field.
Morphometry and comparative histology of sinus and atrioventricular nodes in humans and pigs and their relevance in the prevention of nodal arrhythmi…
2019
The cardiac conduction system is a network structure that allows the initiation and fast propagation of electrical impulses that trigger the electrical depolarization of the myocardial tissue. The purpose of this work is to study the histological and morphometric characteristics of the different components of the sinus and atrioventricular nodes in humans and pigs and their relationship with supraventricular arrhythmias. In this study, we describe the morphometry of the sinus and atrioventricular nodes of 10 adult humans and 10 pig hearts. A computerized morphometric study has been carried out, where we determined the number of cells that compose the nodes as well as different parameters re…
Plasticity of retinal ribbon synapses.
1996
Ribbon synapses differ from conventional chemical synapses in that they contain, within the cloud of synaptic vesicles (SV's), a specialized synaptic body, most often termed synaptic ribbon (SR). This body assumes various forms. Reconstructions reveal that what appear as rod- or ribbon-like profiles in sections are in fact rectangular or horseshoe-shaped plates. Moreover, spherical, T-shaped, table-shaped, and highly pleomorphic bodies may be present. In mammals, ribbon synapses are present in afferent synapses of photoreceptors, bipolar nerve cells, and hair cells of both the organ of Corti and the vestibular organ. Synaptic ribbons (SR's) are also found in the intrinsic cells of the third…
Thirty years of synaptosome research.
1993
Detached synapses (synaptosomes), first isolated by the author in 1958 and identified as such in 1960, are sealed presynaptic nerve terminals often with a portion of the target cell--sometimes amounting to a complete dendritic spine--adhering to their external surface. They can be prepared in high yield from brain tissue and also in decreasing yield from spinal cord, retina, sympathetic ganglia, myenteric plexus and electric organs. They are sealed structures which, under metabolizing conditions, respire, take up oxygen and glucose, extrude Na+, accumulate K+, maintain a normal membrane potential and, on depolarization, release transmitter in a Ca(2+)-dependent manner. They thus provide an …
Quasi-Conformal Technique for Integrating and Validating Myocardial Tissue Characterization in MRI with Ex-Vivo Human Histological Data
2017
Ventricular tachycardia caused by a circuit of re-entry is one of the most critical arrhythmias. It is usually related with heterogeneous scar regions where slow velocity of conduction tissue is mixed with non-conductive tissue, creating pathways (CC) responsible for the tachycardia. Pre-operative DE-MRI can provide information on myocardial tissue viability and then improve therapy planning. However, the current DE-MRI resolution is not sufficient for identifying small CCs and therefore they have to be identified during the intervention, which requires considerable operator experience. In this work, we studied the relationship of histological data (with 10 \(\mu \)m resolution), with in-vi…
The Innervation of Taste Buds in the Soft Palate and Circumvallate Papilla of the Rat as Revealed by the Zinc Iodide-Osmium Tetroxide Technique.
1998
The taste buds in the soft palate and the circumvallate papillae of the rat were investigated by the zinc iodide-osmium tetroxide technique. In addition, electron micrographs of taste buds stained with this method were presented for the first time. Differences in taste bud structures were found between the examined regions. The taste buds of the soft palate showed a complicated plexus of intragemmal nerve fibers. Some fibers exhibited terminal polymorphic swellings. Single branches could be traced close to the space of the taste pore. In the soft palate, the taste bud cells remained unstained, whereas in the circumvallate papillae of the tongue, a subpopulation of taste bud cells could be s…
Zinc accumulation in the telencephalon of lizards.
1987
The zinc concentration in the brains of two species of lizard was determined by atomic-absorption spectrophotometry. The zinc concentration was found to be highest in the telencephalon of Lacerta galloti (21.1 micrograms/g fresh weight) and Podarcis hispanica (16.77 +/- 0.8 micrograms/g) while the mesencephalon and brain stem exhibited lower zinc concentrations, i.e., 7.0 micrograms/g in Lacerta galloti and 6.08 +/- 0.4 micrograms/g in Podarcis hispanica. This high telencephalic concentration of zinc is paralleled by intense and well-defined Timm reactivity used for demonstrating the presence of zinc-containing boutons at the light-microscope level. Volumetric-densitometric studies of these…