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Biomedical subjects

G Forti

Publications and source records attributed to G Forti.

211 records · Page 12Linked to original sources
PubMedDate not supplied

[Mucocutaneous lichen planus with esophageal involvement. A clinical case].

The paper reports the case of a 58-year-old woman suffering from mucosal and cutaneous lichen planus (LP) with esophageal and oral involvement, who had complained of dysphagia for approximately the past two years. The diagnosis of esophageal LP was made using esophagoscopy with mucosal biopsy. The differential diagnosis between LP and progressive systemic sclerosis is discussed; a cold-test, plethysmography of the limbs, an anti-ENA Sci-70 antibody assay, X-rays of soft tissues and esophagomanometry were performed for this purpose, and all proved normal. The presence of conditions implicated in the etiopathogenesis of LP (psychic disorders and the administration of psychoactive drugs, anti-hypertensives and FANS) were observed, together with an already known association with arterial hypertension. Altered hepatic function (with an increase in cholestasis enzymes) was also noted which is probably attributable to the prolonged use of psychoactive drugs (hepatic biopsy showed severe steatosis).

Antihypertensive Agents↗
PubMedDate not supplied

Intracellular calcium accumulation and responsiveness to progesterone in capacitating human spermatozoa.

Progesterone induced a rapid, long-lasting, dose-dependent increase of intracellular free calcium concentration ([Ca2+]i) in human sperm capacitated overnight. This effect was not counteracted by the cytosolic progesterone receptor antagonist RU486 (1 mumol/L) nor by the GABA-A receptor antagonists bicuculline (10 mumol/L) and picrotoxin (50 mumol/L). Also, the rank order of potency of several progestative steroids on [Ca2+]i differed from that previously reported for uterine intracellular progesterone receptor or for P-GABA interaction in the central nervous system, indicating a different pathway for progesterone stimulation of human sperm. Modifications of basal and progesterone-stimulated [Ca2+]i during sperm capacitation were also studied. A progressive, parallel increase of basal and progesterone-stimulated [Ca2+]i in capacitating spermatozoa was found. In particular, progesterone-stimulated [Ca2+]i increased from a basal concentration of 147% +/- 17% at 10 minutes to 327% +/- 65% after 120 minutes of incubation in capacitating medium. This increase was well correlated with basal [Ca2+]i (r = 0.93). In contrast, basal and progesterone-stimulated [Ca2+]i concentrations were constantly low in spermatozoa incubated in noncapacitating medium. In capacitated spermatozoa, initial responsiveness to progesterone and basal [Ca2+]i was higher than in capacitating and noncapacitated samples, and remained constant throughout the duration of the experiment. The progressive, parallel increase of [Ca2+]i and response to progesterone observed during in vitro capacitation of human spermatozoa might be physiologically relevant in vivo during capacitation of sperm in the female genital tract.

Bicuculline↗
PubMedDate not supplied

Increased prevalence of intestinal metaplasia in the gastric mucosa of the elderly: clinical implications.

Evidence which suggests a close relationship between intestinal-type gastric carcinoma (IGC) and intestinal metaplasia (IM) associated with chronic atrophic gastritis (CAG) has accumulated in the literature. The aim of this study has been to analyze retrospectively the prevalence of IM in patients with bioptically-proven chronic gastritis, as well as its age-specific distribution. A series of 230 patients, comprising 162 cases of CAG with IM (70.5%) and 68 cases of gastritis without IM (29.5%-57 superficial type, 11 CAG) was reviewed. All patients underwent upper gastrointestinal endoscopy one or more times, during which multiple biopsies were taken from the gastric mucosa. Moreover, patients were divided into two age-groups: over and under 65 years old. Three features were also investigated: location, endoscopic appearance and clinical manifestations. In agreement with other Authors, our findings showed: 1) predominance of the antral location (B-type gastritis); 2) a close relationship between prevalence of IM and increasing age, with an upward age-related trend. A statistically significant difference was noted between patients with IM and those without the lesion, emerging in the VII decade, with a further rise in the succeeding decade. In line with the literature, these findings emphasize the importance of endoscopic-bioptic follow-up, which takes on even greater significance in elderly patients, in whom an increased incidence of IGC has been reported.

Adenocarcinoma↗
PubMedDate not supplied

Decreased responsiveness to progesterone of spermatozoa in oligozoospermic patients.

Spermatozoa from oligozoospermic subjects are characterized by a reduced in vitro ability to penetrate hamster oocytes and by a decreased responsiveness to physiological stimuli that trigger the acrosome reaction. One of the first steps in the induction of the acrosome reaction is an increase of intracellular free calcium concentrations ([Ca2+]i). It has been recently shown that progesterone (P) is able to increase [Ca2+]i in capacitated human sperm at concentrations similar to those found in follicular fluid. We evaluated sperm [Ca2+]i increase in response to P (0.1 micrograms/ml) in 19 normo- and 17 oligozoospermic subjects. The average percentage of [Ca2+]i increase over the basal level was significantly lower in spermatozoa from oligozoospermic subjects when compared to normozoospermic subjects (138.7 +/- 8.22% increase in oligo- versus 263.3 +/- 39.7% increase in normozoospermic subjects; P < 0.001). Progesterone-stimulated [Ca2+]i increase was significantly correlated with sperm motility (r = 0.54), sperm concentration (r = 0.96), and sperm morphology (% of normal forms) (r = 0.49). In addition P induced a significant increase of acrosome-reacted spermatozoa in normospermic patients (n = 10), whereas no significant effect was observed in spermatozoa from oligozoospermic men (n = 7). Taken together, these results indicate that spermatozoa from oligozoospermic men have a reduced ability to initiate the cascade of events that lead to the acrosome reaction in response to a physiological stimulus, such as P, and might contribute to explaining the reduced fertilizing capacity of these patients.

Acrosome↗
PubMedDate not supplied

The potent relaxant effect of adenosine in rabbit corpora cavernosa is nitric oxide independent and mediated by A2 receptors.

In the present study the effect of adenosine and adenosine analogues on rabbit isolated cavernosal smooth muscle has been evaluated in comparison with the effect of acetylcholine and electrical field stimulation. In the presence of guanethidine and indomethacin, acetylcholine and electrical field stimulation relaxed the rabbit corpus cavernosum, which was precontracted with phenylephrine. The nitric oxide synthesis inhibitor, N omega-nitro-L-arginine-methylester (L-NAME), greatly reduced the relaxation induced by electrical stimulation and completely abolished the relaxant effect of acetylcholine. A concentration-dependent relaxation of the rabbit corpus cavernosum was produced by adenosine; this effect was not modified by L-NAME, but was reduced by adenosine deaminase. On the other hand, the adenosine-induced relaxation was potentiated by the inhibitor of adenosine deaminase, erythro-9-(2-hydroxy-3-nonyl)adenine and by the adenosine uptake inhibitor dipyridamole. Moreover, the effect of adenosine was antagonized by the unspecific adenosine receptor antagonist 8-phenyltheophylline. The receptor subtypes involved in cavernosal relaxation were characterized by using selective receptor antagonists: 1,3-dipropyl-8-cyclopentylxanthine, a blocker of A, receptors, did not modify adenosine-induced relaxation. This effect was, however, antagonized by the A2-receptor antagonist CGS15943. A relaxant effect was also obtained with nanomolar concentrations of two synthetic adenosine analogues, the preferential A2 receptor agonist 5'-N-ethylcarboxamidoadenosine and the A2a selective agonist CGS21680. These results demonstrated that adenosine has potent relaxant activity on the corpus cavernosum, acting through a mechanism different from the nitric oxide pathway, and that receptors involved in the effect of adenosine belong to the A2a subtype.

Acetylcholine↗