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Biomedical subjects

A Vittoria

Publications and source records attributed to A Vittoria.

At least 19 recordsLinked to original sources
PubMed1992

Immunocytochemistry of paraneurons in the female urethra of the horse, cattle, sheep, and pig.

The aim of this study is to describe the presence of neuroendocrine (NE) cells (paraneurons), producing biogenic amines and/or peptidergic hormones, in the female urethra of cattle, sheep, pigs, and horses, by means of histochemical and double labeling immunofluorescent techniques. 5-Hydroxy-tryptamine-, chromogranin A-, cholecystokinin- and somatostatin-containing NE cells are present in the urethral epithelium of all the species studied, with the unique exception of the lack of somatostatin cells in the horse. Paraneurons containing 5-hydroxytryptamine colocalized with chromogranin A or cholecystokinin were also found in all subjects. Such active substances are hypothesized to play a role in the contraction of the urethral musculature, emission of urogenital fluids, and inhibition of endocrine and exocrine secretions.

Amines↗
PubMed1992

Vasoactive intestinal polypeptidergic innervation and gastroenteropancreatic system: an immunocytochemical study in the hedgehog Erinaceus europaeus.

The pattern of the digestive vasoactive intestinal polypeptide (VIP)-ergic innervation is described immunohistochemically in the hedgehog Erinaceus europaeus. This animal is a small-sized, wild, nocturnal, lower eutherian mammal whose gastrointestinal tract shows some similarities with the avian gut. The myenteric plexus of the stomach, the mucosa of the small intestine and the circular muscle layer of the large intestine are the best VIP-innervated structures. The pattern of the positive innervation is similar to that described in other mammals and in some bird species. The widespread diffusion of the neuropeptide in the gut is probably due to the importance of its functions in the digestive physiology.

Animals↗
PubMed1992

VIP-immunoreactive nerve structures of the gastrointestinal tract in the developing and adult domestic duck.

The first appearance and distribution of VIP-containing nerve structures were studied in the gut of embryonal, newly hatched and adult domestic ducks. Immunoreactive structures appeared in the mesenchyme of the gizzard-duodenum junction (antrum) at 5 days of incubation, and soon after diffused both cranially and caudally. Early in development, VIP-positive cell bodies were more numerous than positive fibres, appearing 3 days before the latter. Later on, the positive cell bodies decreased in number while the fibres increased. In the foregut, VIP-positive structures firstly appeared in the myenteric plexus while in the mid- and hindgut they appeared simultaneously in the myenteric and submucous-plexuses. The gastrointestinal VIP-innervation in newly hatched ducks differed from that of the adult because of the incomplete development of its mucosal component. The findings obtained indicated following: The time interval from 13 to 17 days of incubation seems critical for the growth of the gastrointestinal VIP-containing neurons. The molecular factors regulating the appearance of neuronal phenotypes are probably synthesized early in the avian gizzard development. VIP is widely diffused in the rectum where it may play important roles in regulating the onset and synchronism of peristaltic and anti-peristaltic movements.

Animals↗
PubMed1990

Relationships between octanol-water partition data, chromatographic indices and their dependence on pH in a set of beta-adrenoceptor blocking agents.

A thorough investigation on the dependence of octanol/water distribution coefficients (log D) of basic and amphiprotic beta-blocker drugs on pH and pKa values has been carried out. An attempt is made to clarify the factors which govern the chromatographic parameters (log k') in reversed-phase high performance liquid chromatography (RPLC) in terms of chemical structure and of distribution coefficients. The correlations between log D and log k' of different compounds show that the bulkiness and the branching of nitrogen substituent are controlling factors in RPLC measurements. Finally, an ion pair chromatographic system is considered for the prediction of octanol/water partition coefficients.

Adrenergic beta-Antagonists↗
PubMed1990

Serotonin-, somatostatin- and chromogranin A-containing cells of the urethro-prostatic complex in the sheep. An immunocytochemical and immunofluorescent study.

The urethral and prostatic epithelial of the sheep contain a large number of amine- and/or peptide-producing neuroendocrine cells (NE), also called paraneurons. Four different cell types have been immunohistochemically recognised among them. The first contains the amine serotonin, the second the protein chromogranin A, the third the amine and the protein together and the fourth the hormone somatostatin. Serotonin-producing cells are elongated in shape and often show cytoplasmic dendrite-like processes directed towards the basal membrane and/or the lumen. Chromogranin A-containing cells are polymorphic and constitute the more numerous NE subpopulation. Cells containing both the bioactive substances seem to be less numerous than the chromogranin A cells and slightly more frequent than the serotonin cells. All these cell types are diffused along the whole urethro-prostatic complex and show their highest density in the collicular zone. Somatostatin-containing cells often show a unique cytoplasmic extension directed towards the basal membrane and are rare. It is supposed that the presence of serotonin in the urogenital tract is functionally correlated with the emission of urine and/or semen, while somatostatin is associated with the inhibition of local exocrine and/or endocrine secretions.

Animals↗
PubMed1989

Chromogranin- and somatostatin-containing neuroendocrine cells in the porcine uterus. An immunocytochemical study.

Endocrine cells scattered in organic mucosae were defined "Neuroendocrine" (NE) cells because they constitute a section of the Diffuse Neuroendocrine System (DNES). Such cells have never been evidentiated in the normal endometrium. By means of histochemical and immunohistochemical techniques, NE cells, some of which contain the hormone somatostatin, are described in the glandular epithelium of the uterine horn in non-pregnant, non-castrated, young and adult sows. As is known, the uterine horn is the organ of pregnancy in the pig. The localization, distribution and morphology of the uterine NE and somatostatin-containing cells are reported and the importance of their function, in the pregnant and non-pregnant porcine uterus, is discussed.

Animals↗
PubMed1989

Urogenital paraneurons in several mammals.

Amines and/or peptide-producing cells, deserving to be called paraneurons, were demonstrated in the urethro-prostatic complex of the man, rabbit, buffalo and sheep and in the uterine horns of the pig, horse and mouse, by means of histochemical, immunohistochemical, immunofluorescent and double labeling immunofluorescent techniques. In particular, the urethro-prostatic complex of the sheep contains cells producing serotonin, chromogranin A and somatostatin. Often the amine and the "marker"-protein were colocalized in the same cells. Chromogranin A- and somatostatin-containing cells were found in the uterine horns of the pig. Serotonin probably plays a role in the contraction/relaxation of the musculature of the male urogenital tract, thus regulating the urinary and spermatic flow. The function of somatostatin cells in the urogenital tract is unknown. The presence and direction of their cytoplasmic processes lead us to hypothesize a double endocrine/paracrine modality of action.

Adrenocorticotropic Hormone↗
PubMed1989

Toward a quantitative comparative toxicology of organic compounds.

Correlation equations between logP (P = octanol water partition coefficient) and the biological activity of alcohols has been derived for 101 examples on all sorts of systems, from simple proteins to whole animals. This provides an overview of the toxic nature of hydrophobic compounds which can be used as a basis for comparison of more complex chemicals. About 100 examples of the hydrophobic effects of chemicals, other than alcohols, to various living systems or their parts are presented for comparison. It is clear that hydrophobic xenobiotics are toxic to almost every form of life, including humans (or parts there of).

Animals↗
PubMed1988

Staining of neuroendocrine cells by Linder's argyrophil method.

Linder's argyrophil method, recently developed to stain nervous structures, is useful in the histochemical study of amine- and/or peptide-producing neuroendocrine (APUD) cells. On sections from various organs of four animal species Linder's method worked well and rapidly stained the neuroendocrine cells yellow, red or black; it stained black nervous structures against a pale yellow background. Double staining of single sections from Bouin-fixed gastric mucosa of rabbits demonstrated the correspondence of both Linder- and Grimelius-positive cells. Rapidity of application, intensity of impregnation and reproducibility in results are the best features of Linder's method when applied to the study of the neuroendocrine system.

Animals↗
PubMed1988

Effect of a single dose of mesoglycan on the human fibrinolytic system, and the profibrinolytic action of nine daily doses.

The profibrinolytic activity of orally administered Mesoglycan was evaluated in 18 patients affected by impaired plasma fibrinolytic activity. Mesoglycan was administered by a single oral dose of 24, 48 or 72 mg on 1 day, and by repeated doses of 48 mg twice a day for 9 consecutive days. After the single administration all the fibrinolytic parameters were significantly and positively influenced with an order of magnitude and a duration of effects proportional to the dose employed. After the repeated administration, a constant and reproducible activation of the fibrinolytic system was observed without any interference with haemocoagulative parameters. These results confirm that Mesoglycan is endowed with a relevant profibrinolytic activity in man after oral administration. The pharmacological activity of Mesoglycan could possibly involve the liberation of a certain amount of plasminogen tissue activator.

Administration, Oral↗
PubMed1988

[Analysis of the correlation between hydrophilic-lipophilic balance, coefficient of diffusion and hydrogen ion concentration in a series of nonsteroidal anti-inflammatory drugs].

A thorough investigation on the dependence of rate diffusion constants (Kd) of nonsteroidal antiinflammatory drugs on pH and pKa values was carried out. It is shown that a modified multiparametric curve-fitting technique may constitute an useful tool to describe the rate diffusion pH-profiles of ionogenic substances. A comparison between the Kd values and the corresponding distribution coefficients (log D) shows that these constants identify complementary parameters very useful in the study of structure-activity relationships of ionogenic substances.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1986

Ultrastructural modifications of the platelet plasma membrane in vascular diseases and the effect of a carbochromen derivative as studied by freeze-fracture and computer measurement.

A high surface density of the openings of the surface connected canalicular system (SCCS) has been observed in the freeze-fractured plasma membrane of circulating platelets in rabbits fed an atherogenic diet and in hypercholesterolemic type IIa patients. In vitro tests have revealed a correlation between the increased surface density of the SCCS openings and the initial steps of platelet activation. 8-Chlorocarbochromen, a new drug which enhances the in vivo release of prostacyclin from the arterial wall, has been found to be effective in reducing the high surface density of SCCS openings in platelets of rabbits on an atherogenic diet. The present study shows that circulating platelets from patients with peripheral vascular disease present a high surface density of SCCS openings compared to that observed in control subjects. After a single oral administration of 8-chlorocarbochromen, a reduction of the high number of these openings has been observed. Likewise, beta-thromboglobulin levels were found to be high in the patients and to be significantly reduced after oral administration of the drug. This study shows ultrastructural modifications of platelets in conditions related to atherosclerosis and includes data on the effectiveness of 8-chlorocarbochromen in reducing the platelet activation of these patients.

Administration, Oral↗
PubMed1986

Defibrotide therapy for thrombophlebitis--controlled clinical trial.

Deep venous thrombosis is a common disease with significant danger of both acute and chronic complications. Widely accepted therapies are based on anticoagulant (heparin and/or anticoagulant agents) or early fibrinolytic therapy. All these therapies frequently have severe side effects. Defibrotide is a new drug with antithrombotic and profibrinolytic activities but without anticoagulant activity and major side effects. To evaluate the efficacy of this drug against acute thrombophlebitis, we treated a group of 10 patients with 200 mg defibrotide intravenously three times a day for 15 days. Fibrinolysis parameters were monitored every other day. The indices of venous function by strain-gauge plethysmography and venous occlusion were evaluated every 7 days. The drug induced a significant improvement in plethysmographic indices and a significant profibrinolytic activity. Defibrotide-treated patients showed a fast disappearance of clinical and instrumental signs of thrombophlebitis. No side effects were reported during the study.

Aged↗