Sylvio Ferri

Lysosokal enhancement in hepatic cells of a teleost fish induced by cadmium

The toxic effects of cadmium upon the hepatic cells of a freshwater fish were studied. The experiment was developed by the addition of cadmium chloride in the water and histochemical and EM methods were performed. The results showed that acute intoxication induces an increase of lysosomal activity related to the shape, distribution as well as different functional degrees of the organelle condensation. The authors analyze the different situations whose leading alterations of lysosomal behaviour and the probable mechanisms of cadmium action.

Intestinal histology of a detritivorous (iliophagous) fish Prochilodus scrofa (characiformes, prochilodontidae)

Abstract The intestinal epithelium of Prochilodus scrofa, a freshwater teleost fish, was studied by means of light microscopic techniques. The samples were obtained from the initial, middle and terminal portions of each intestinal loop. The pyloric caeca are lined by a simple columnar epithelium with a small striated border and a very thick basal membrane. Goblet cells, lymphocytes and eosinophil granular cells (ECGs) were observed in the epithelium of all the intestinal loops. The lamina propria of the third intestinal loop is characterized by a high glandular density. At the fourth loop and up to the rectal segment, thick flaps of mucous membrane project into the lumen, resembling the valves found in mammalian veins, apparently preventing the reflux of intestinal contents. At the fourth and fifth intestinal loops an intense intraepithelial invasion of phagocytic cells occurs (macrophage, ECG and lymphocyte). Goblet cell concentration is higher at the sixth intestinal loop and rectal segment.

Histometric study of age related changes in the thoracic aorta of Callus gallus (Linnaeus, 1758).

SummaryThe authors have studied the quantitative variations of elastic and collagenous fibers, muscle cells and cellular population in the mesarteria of the middle portion of the thoracic aorta of Gallus gallus from 1 day to 36 months of age. A histometric method has been employed, using an integrating eyepiece I (Zeiss Oberkochen) for the countings.The results obtained show that the concentration of elastic fibers increases from the first to the 30th day of age, decreasing from this point until 36 months while that of the collagenous fibers increases during the first and second period. The muscular tissue increases its concentration from the 30th day to 36th month, while the cellular population decreases from the 15th to 30th day, then remaining, stable until 36 months. From the variations pointed out here for the different elements studied between 30 days and 36 months of age, only those of the eollagenous fibers were linear with age.

Histochemical (polysaccharides, proteins, nucleic acids and enzymes) and autoradiographic (incorporation of 35S labelled sodium sulfate) study of the epithelial intestinal cells of Xenodon merremiiWagler, 1824 (Ophidia)

A histochemical and autoradiographic study of the lining intestinal epithelium of the snake Xenodon merremii is reported. The absorptive cells present neutral polysaccharides, arginine, tyrosine, tryptophan, cysteine, alkaline phosphatase, acid phosphatase, ATPase, AMPase, esterase and RNA. There are histochemical differences between the goblet cells of the small and of the large intestine. Whereas in the former predominates the neutral polysaccharides and are found arginine, tyrosine, tryptophan and cysteine, in the latter predominates the sulfated polysaccharides (confirmed by the uptake of radioactive sulfur) and no amino acids were found.

Morphological Study of the Esophagus of Xenodon merremii Wagler, 1924 (Ophidia)

The histology of the esophagus of the snake Xenodon merremii was studied. It presents all layers of the digestive tract in general: the mucosa, submucosa, muscle layer and serosa. The muscosa shows a special epithelium with ciliated and goblet cells in the initial portion, gradually displaced by columnar cells in the posterior third of the organ. Other cellular types, such as basal cells, argentaffin and argyrophil cells can be found throughout the esophageal mucosa.

Electron Microscopic Observation on the Structure of a Freshwater Teleost Dermis with Special Reference to the Dermo‐epidermal Junction

An electronmicroscopic study of the dermis of the ventral skin of a fresh water teleost (Pimelodus maculatus) was examined with standard techniques. It was demonstrated that the dermal organization consists of a well developed basal membrane underlying the epidermis, and two collagenous layers (stratum compactum most superficially and stratum spongiosum, deep to it) which are separated by a layer of elastic connective tissue. Within the superficial layer melanocytes and iridophores were demonstrated.

Ultrastructural Observations on Nerve Fibres in a Freshwater Telecost Epidermis

A study of nerve endings in the skin of a fresh water teleost (Pimelodus maculatus) was conducted with the aid of electronmicroscopy. It was demonstrated that in general the cutaneous innervation is similar to that of other fish. Nerve endings were demonstrated throughout the epidermis but did not reach the skin surface. The endings appeared to be associated with filament containing epidermal cells and were located within grooves on the surfaces of these cells. The cyroplasmic components of these nerve endings were similar to those of other species of fish and mammals.