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Biomedical subjects

S Ferri

Publications and source records attributed to S Ferri.

At least 145 records · Page 8Linked to original sources
PubMed1982

Temperature induced transformation of teleost (Pimelodus maculatus) epidermal cells.

Superficial epidermal cells of the teleost Pimelodus maculatus show modifications after heat exposure (36 degrees C) for 3 days. Heat treatment affects the arrangement of cytoplasmic filaments resulting in the disappearance of the microridges. The fish maintained at 36 degrees C during 3 days show modifications in the cytoplasmic organization of their superficial epidermal cells. The most conspicuous alterations are: apparition of lysosomes (including autolysosomes), hypertrophy of the GOLGI complexes, disappearance of the RER, and modifications in the nuclear envelope. Epidermal cells maintained at 36 degrees C for 10 days are transformed into horny-like cells. The differences and resemblances with keratinized cells of terrestrial vertebrates are described and discussed.

Animals↗
PubMed1982

[Occurrence of HLA B27 antigen in ankylosing spondylitis in Italy].

39 individuals from Middle and South Italy were selected for being affected by ankylosing spondylitis (AS) (N = 22) or by sacroiliitis (SI) (N = 17) and typed for the HLA system antigens. 320 healthy individuals were typed as control population. The following phenotypic frequencies of HLA-B27 were found; 68% in AS patients, 71% in SI patients and 5% in controls. The frequency of B27 observed among our AS patients is lower than those observed in other caucasian patients. Our data may be explained either by a genetic hypothesis or by an environmental hypothesis; data reported by other authors let we believe that the last one is more reliable.

Gene Frequency↗
PubMed1982

Myenteric plexus in a freshwater teleost intestine. I. Quantitative study of nerve cells.

The number of nerve cells in the myenteric plexus of a freshwater teleost (Pimelodus maculatus) was obtained with the aid of statistical methods. 1. The density of neurons/cm2 was the following: 91,142 in the duodenum; 93,133 in the ileum and 82,857 in the rectum. These 3 portions have not showed statistically significant differences. 2. The mean surface area of the intestine being 48 cm2, the total number of neurons in myenteric plexus of the duodenum, ileum and rectum was calculated to be 4,274,112.

Animals↗
PubMed1982

Fine structure of a freshwater teleost (Pimelodus maculatus) intrahepatic biliary pathways.

The intrahepatic biliary passages of a teleost liver composed by a muralium duplex was studied by electron microscopy. The bile canaliculus was commonly formed by 2 or more hepatic cells. In the transition zone between the intercellular bile canaliculus and the bile ductule, this duct was formed in part by hepatic cells and in part by duct cells. While the number of duct cells increased, the number of hepatocytes decreased until the entire ductule was formed by 2 or 3 duct cells. Bile duct was formed only by pyramidal duct cells. These cells are readily distinguished from the hepatocytes by its irregular shape, by a paucity of organelles and by the abundance of microfilaments.

Animals↗
PubMed1981

Ultrastructural study of the endothelial cells in teleost liver sinusoids under normal and experimental conditions.

The ultrastructure of the endothelial cells of liver sinusoids was studied in the teleost, Pimelodus maculatus. These cells have the ability to form pinocytotic vacuoles, starting with the formation of marginal folds. The latter occur in many cells after stimulation by India ink injections and ink particles are ingested by pinocytosis and by micropinocytosis. Desmosomes, structures rarely described between liver sinusoidal endothelial cells, are present in this species.

Animals↗
PubMed1981

Ultrastructural study of Kupffer cells in teleost liver under normal and experimental conditions.

The Kupffer cells in the liver of the teleost fish, Pimelodus maculatus, are attached by desmosomes to the endothelial cells lining the sinusoids. These provide a strong attachment allowing them to resist the passage of blood. Following perfusion with India ink, both endothelial and Kupffer cells ingest India ink particles by pinocytosis and micropinocytosis. It is suggested that both cell types may represent two different functional states of the same cell.

Animals↗
PubMed1981

Investigations on behavioral effects of an extract of Cannabis sativa L. in the rat.

The behavioral responses of the rat to an extract of Cannabis sativa were examined after IP injection of 5, 15 and 30 mg/kg (expressed as delta 9 tetrahydrocannabinol). The lowest dose of the extract induced stereotyped behavior (rhythmic head movements, intermittent gnawing and sniffing) together with hypersensitivity to stimuli and hyperthermia. The administration of higher doses of the extract resulted, initially, in similar behavioral effects but of greater intensity, followed by a cataleptic state alternating with atonic muscular prostration; rectal temperature was decreased. Pre-treatment with 6-hydoxydopamine (6-OHDA, which produces degeneration of catecholamine-containing nerve terminals)or pimozide (blocker of dopamine receptors) significantly reduced both stereotype and hyperreactivity. Thermic effects were also antagonized by 6-OHDA pre-treatment. Cannabis-induced catalepsy was enhanced by pimozide but reduced by atropine (3 mg/kg SC). These results support the hypothesis that catecholamines play an important role in the complex behavioral effects of cannabis.

Animals↗
PubMed1981

Fine structure and intercellular junctions of a freshwater teleost (Pimelodus maculatus) hepatocytes by freeze-fracture replicas.

The Pt-C replicas of a freshwater teleost hepatic cells were studied by electron microscopy. The surface of hepatocytes bordering the perisinusoidal space is studied with numerous microvilli. Cell-to-cell attachments are made through gap junctions and spot desmosomes. Tight junctions are found between hepatocytes close to the bile canaliculi. Some of the numerous corpuscular elements found in the cytoplasm can be identified as organelles, specially if their interiors are partially exposed by cleaving.

Animals↗
PubMed1981

Ultrastructural study of the pit cell in a freshwater teleost liver.

This report includes the first ultrastructural description of pit cells in a teleost liver. These cells are found in the vicinity of biliary ductules, between hepatocytes, beneath the endothelial lining of blood vessels, in the hepatic capsule, and in the lumen of sinusoids. Although their characteristic granules are concentrated in certain preferential regions of the cell they are not entirely polarized to one side of the nucleus. The function of pit cells is unknown but their morphological characteristics suggest an endocrine function.

Animals↗
PubMed1980

Evidence of an involvement of the opioid peptidergic system in the reaction to stressful conditions.

Rats exposed to combined cold and restraint exhibited reduced paw oedema following an injection of carrageenin. Under the same experimental conditions, the local inflammation became fully evident when animals were pretreated with naloxone, 5 mg/kg, s.c. The same dose of the narcotic antagonist also increased the intensity of gastric damage in restrained, cold-exposed rats. On the contrary, gastric ulcerations were practically inexistent in stressed rats treated with 10 mg/kg s.c. of morphine. It is suggested that the opioid peptidergic system is involved in the body's reactivity to stressful stimuli.

Animals↗
PubMed1980

Changes in opiate activity of rat pituitary following acute administration of neuroleptics.

An increase was found in the opiate activity of pituitary extracts obtained rom rats injected with the neuroleptic drugs trifluoperazine and sulpiride. The increase of opiate activity, measured by bioassay, was particularly evident 2 h after the administration of sulpiride. Dexamethasone completely prevented the neuroleptic-induced effect. Trifluoperazine and sulpiride may have affected dopaminergic mechanisms regulating endorphin storage in the pituitary.

Animals↗