Claudio A. Ferraz de Carvalho

Ultrastructural morphometric study on developing acinar cells of the rat pancreas and parotid gland.

The fraction of cellular volume occupied by the cytoplasm has been assessed by point-counting volumetry in 0.5 micrometer araldite sections. Measurement of the transection radius of the nuclei of acinar cells allowed the assessment of the mean nuclear volume according to the method of Bach. With these data, the cytoplasm volume was calculated in cubic micrometers. Ultrastructural morphometric data were obtained by means of superimposing on the electron photomicrographies (x 21,000 or x 28,500) a test system of 84 evenly spaced segments according to Weibel et al. The analysis of the values obtained for the pancreas and parotid gland allowed for the supposition that the process of maturation in the rat, either for the pancreas or the parotid gland, occurs simultaneously with the mitotic process, this last being held as the predominating one in the first 3--4 postnatal weeks. The cytodifferentiation process becomes more marked in the last phases studied and on the 40th day it already shows parameters held as similar to those of the adult animal.

Age-related changes in elastic fibers of human heart

The effects of age on the human heart elastic fibers were studied by light and electron microscopy. Studies were done on 15 hearts from male subjects 42 days to 87 years of age. Using specific staining procedures, the length of elastic fibers was determined by morphometry in the parenchyma of right and left ventricles. These studies suggest that the length of elastic fibers per unit heart volume is present early in life, possibly at birth, and thereafter remains constant until adulthood. Average fiber length increases significantly beyond the third decade of life which can be interpreted as a continuous formation of new fibers and a continuous apposition of elastic-type material to these fibers. Electron microscopy confirmed the presence of mature elastic fibers at birth, since they contained amorphous substance (elastin) surrounded by numerous microfibrils. In the adult hearts, the amount of amorphous substance has increased and the number of microfibrils has decreased. With advancing age the amorphous substance forms areas of rarefaction and the microfibrils have disappeared. Whether or not such morphometric modifications could influence the elastic properties of the ventricular myocardium requires further study.

Functional Architecture of the Splenic Vein in the Adult Human

The spatial arrangement of the muscular, elastic and collagenous fibers was examined in 20 splenic veins of adult humans. Histologic and panorganographic sections were stained by the following methods

Histological and histochemical study on the ependyma of Bradypus tridactylus

Histological and histochemical aspects of the whole encephalic ventricular system of eight specimens of Bradypus tridactylus were studied. After anesthesia and perfusion, the encephalons were obtained by craniotomy. Transverse serial sections of the encephalon, stained according to Azan (Heidenhains method) or Kluver-Barrera for nerve cells and myelinated nerve fibers; silver impregnation was carried out according to Cajal-De Castros or Palmgrens methods. The following histochemical reactions were used: PAS (McManus), metachromasia, acid phosphatase (Gomori), Brachets and Gomoris trichromic reaction (modified by Bargmann for neurosecretion). Histologically, different characteristics of the ependymal cells in different areas were observed, which would be related to functional peculiarities of each area of the encephalic ventricles. The ependymal cells showed discrete apical basophilia due to the presence of RNA which disappears after treatment with crystalline ribonuclease. The PAS reaction indicated the presence of a small quantity of PAS-positive substances in the apical zone of the ependymal cells and the subependymal tissue. These substances disappeared after the salivary amylase test, indicating the presence of glycogen. The acid phosphatase reaction was negative.

Ultrastructural study on topographical variations of the ependyma in Bradypus tridactylus

An electron-microscopic study of ependymal cells in 24 different areas of the encephalic ventricular system of Bradypus tridactylus was made, with a view to making a comparative analysis, of a topographical kind, of various cell components: cilia, microvilli, plasma membrane, cytoplasmic protrusions, types of cellular junctions, ribosomes, Golgi apparatus, endoplasmic reticulum, microfilaments, microtubules, mitochondria, granules and dense bodies. There were differences in the distribution of all these cytologic elements, according to the topography, being a complement to a similar work done by the same authors with light-microscopy. By means of a morphofunctional analysis they draw the conclusion that even if one can admit the passage of substances by an intracellular route, on the other hand few facts support the idea the intracellular absorption or secretion could be considered as important phenomena in a great number of the ependymal areas studied.

Identification of collagen, elastic, elaunin and oxytalan fibres in ganglia of the myenteric plexus of the human oesophagus.

SummaryThe connective tissue associated with the myenteric plexus of the human oesophagus was studied by light and electron microscopy. Collagen fibres were identified by picrosirius staining with polarization microscopy and from their fine structural morphology. A capsule of connective tissue invests the ganglia while septa of connective tissue separate groups of ganglion neurons, surrounding each individual ganglion neuron and each nerve bundle. Collagen fibrils surround the ganglia, each ganglion neuron and each nerve bundle. The fibrils are disposed in various orientatons forming networks. Elastic, elaunin and oxytalan fibres were identified by their staining characteristics and fine structural morphology. The bulk of the ganglion sheath consists of coarse elastic fibres and elaunin fibres. Elaunin and oxytalan fibres form the intraganglionic network. Oxytalan, elaunin and elastic fibres appear to be located in areas related to different stresses and deformation to which the ganglia of the myenteric plexus are exposed during the contraction of the esophageal wall. The ganglia of the myenteric plexus of the human oesophagus show structural organisation of the connective tissue component similar to that seen in sympathetic and parasympathetic ganglia.

Morfometria do miocárdio humano em indivíduos senis

OBJECTIVE To carry out a quantitative assessment in human myocardium cells of senile individuals, in right, left and septal ventricular regions. METHODS Five hearts from corpses of individuals without heart diseases, of both sexes, with age between 67 and 87 years old were used. The following parameters were assessed: myocyte unit cross section area (myoc. a(o)); myocyte unit perimeter length (myoc. l(o)); myocyte unit volume (myoc. v(o)); myocyte volumetric density (myoc. V(v)); number of myocytes per volume unit (Nmm 3myoc.). The t-test of Student was used in statistic analysis. RESULTS The analysis of differences (p < 0.05) among right (RV), left (LV) and septal (S) ventricular regions of human heart showed that myoc. a(o) values were lower in RV (1.51 +/- 0.10 microm2) and in S (1.55 +/- 0.07 microm2) in relation to LV (1.84 +/- 0.24 microm2). Values of myoc. l(o) were also shown lower in S (5.11 +/- 0.46 microm) comparing to LV (6.2 +/- 0.97 microm). Likewise, myoc. v(o) and myoc. V(v) showed lower values in RV (88.75 +/- 25.37 microm3; 0.39 +/- 0.03%) in relation to LV (122.41 +/- 16.31 microm3; 0.41 +/- 0.01%). CONCLUSION Results obtained show that there may be changes in dimensions of left ventricular wall myocyte cell during senescent stage. However, those differences are subtle and seem to mean the adjustment of tissue to functional changes that install along life.

Correlative scanning and transmission electron microscopic study on the ependymal surface of Bradypus Tridactylus

Topographical variations of the ependymal surface of the whole brain ventricular system of Bradypus tridactylus were studied at the scanning electron microscope after CO2 critical point drying and carbon-gold coating. Certain selected areas were also studied at the transmission electron microscope, following standard technical procedures. We observed distinct patterns in the distribution of cilia, microvilli and supraependymal structures (nerve-like and fibrous astrocyte fibers), and also a small number of blebs. It the lateral transition zone between the floor and roof of the lateral ventricle were found interconnected stellate bulgings measuring an average 98 x 190 microns, constituted by a complex meshwork of processes from fibrous astrocytes, without ependymal lining and with few cell bodies. In the junction between these formations and the underlying neuropil, ciliated ependymal-cell-like glial cells were found to delimit complex labyrinthic spaces. Based on the morphological findings, morpho-functional considerations are made.

Venous angioarchitecture of the tunica muscularis in the esophagogastric transition segment in man

With the pupose of studying the venous angioarchitecture of the esophagogastric transition segment (EGTS), 30 specimens were obtained from bodies a few hours after death. These specimens were injected

Correlative scanning and transmission electron microscopic study on the ependymal surface of Cebus apella

Topographical variations of the ependymal surface of the whole brain ventricular system of Cebus apella, a wild Brazilian species, were studied at the scanning electron microscope after CO2 critical point drying and carbon-gold coating. Certain selected areas were also studied at the transmission electron microscope, following standard technical procedures. We observed distinct patterns in the distribution of cilia, microvilli, other cell projections, and the so called supraependymal structures. Based on the morphological findings, functional considerations are made.