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F Leone

Publications and source records attributed to F Leone.

At least 55 records · Page 3Linked to original sources

Pancreas transplantation in the rat using Lee's technique: a reliable model in experimental microsurgery.

Numerous unresolved problems, both technical and immunological, in pancreas transplantation stimulate experimental studies. Dogs have been routinely used in experimental studies but today rats are more commonly used. However, pancreas transplantation in the rat presents complex technical problems and requires a good knowledge of microsurgical techniques. In 1983 Squifflet undertook an experimental study aimed at evaluating the technical aspects of pancreas transplantation in the rat and calculating the success rates using different methods. The comparison of four methods revealed to our surprise that 100% of the rats operated on using Lee's technique had complications, with a 0% survival rate. In our study we report our experience using Lee's technique which we had the opportunity of mastering directly under the supervision of Professor Lee. We performed 100 pancreas transplantations using Lee's technique and divided our study in two phases. In the first phase we performed 70 pancreas transplantations and overall survival, after 1 week, was 42 rats (60%). In the second phase on 30 rats diabetes was induced by administering 70 mg/kg of streptozotocin. These 30 diabetic rats underwent pancreas transplantation and overall survival, after 1 week, was 25 (83.3%). We believe that our successful survival rates could probably be explained by the close collaboration between Lee and our department. Moreover, we noted the importance of constant training in obtaining better results, and in our opinion Lee's technique of pancreas transplantation is a reliable experimental model which can be used to resolve problems linked to pancreas transplantation.

Animals↗

Effect of a combination of ethinylestradiol and desogestrel in adolescents with oligomenorrhea and ovarian hyperandrogenism.

Nine oligomenorrheic adolescent girls with a clinical and hormonal picture of ovarian hyperandrogenism were treated with a monophasic oral contraceptive (OC) containing 0.03 mg ethinylestradiol (EE) plus 0.150 mg desogestrel (DOG) for six months. The same treatment was administered in eight eumenorrheic adolescents. In both groups the treatment induced a decrease in LH, FSH, androstenedione (delta 4-A), testosterone (T) and dehydroepiandrosterone sulphate (DHEA-S) levels associated with a significant sex-hormone-binding globulin (SHBG) increase. In oligomenorrheic adolescents a marked decrease in both the total ovarian volume and the number of cystic follicles was observed. All parameters, except SHBG and ovarian volume in hyperandrogenic girls, returned to pre-treatment values 3 months after treatment. Subjective improvement of skin problems occurred in six of the nine oligomenorrheic girls. Although temporary, the EE + DOG formulation pill is effective in the treatment of ovarian hyperandrogenism in adolescents. It may also be useful for the prevention of the progressive transformation in the 'classical' and 'irreversible' micropolycystic ovary of adult age.

Adolescent↗

Epidemiological study of parasitic infections in Somali nomads.

In Somali nomads the incidence of intestinal helminths is very low compared with that observed in Somalian closed institutions and practically no Entamoeba infection occurs. Schistosoma haematobium eggs are observed in urine of 50% of adults nomads. Immunological tests reveal that the relative prevalences of leishmaniasis (the lowest), malaria, and toxoplasmosis (the highest) in nomads are similar to those shown by the same techniques in settled communities.

Adolescent↗

Doppler test after microvascular anastomoses and evaluation of somatostatin administration in segmental canine pancreas autotransplantation. A preliminary study.

Segmental pancreatic transplantation still involves a certain number of possible technical complications. The experimental studies in dogs reported here evaluate the effectiveness of vascular microanastomoses using doppler velocimetry in two groups of dogs which underwent segmental pancreatic autotransplantation. One group was protected by intraoperative somatostatin infusion, while the other was kept as control. The obtained results indicate that the doppler-test revealed early vascular complications (2/20 animals) and that somatostatin administration may play a major role in the prophylaxis of pancreatitis.

Animals↗

Effects of calcitonin, parathyroid hormone and its related fragments on acquisition of active avoidance behavior.

The acquisition of active avoidance response was studied in rats injected intracerebroventricularly with calcitonin (CT), parathyroid hormone (PTH) or PTH-related fragments. PTH and PTH65-84 facilitated the acquisition of shuttle-box active avoidance behavior as indicated by the number of conditioned avoidance responses and the percentage of animals reaching the learning criterion. PTH1-34 and PTH44-68, on the contrary, inhibited the acquisition of active avoidance behavior, while CT totally suppressed this behavior in the rat. It is possible that the opposite effects of PTH and CT on learning ability of the rat depend on a different action on calcium metabolism.

Animals↗

Degeneration and regeneration of neuromuscular junctions in chicken iris muscle after crush of the ciliary nerves: a study of ultrastructural changes and of cholinergic enzymes.

Degeneration of neuromuscular junctions in the iris muscle was observed to have occurred 4 days after ciliary nerve crush. By day 10 reinnervation had commenced and by day 30 the maturation of neuromuscular junctions was nearly complete. The loss and recovery of acetylcholinesterase activity in the iris muscle paralleled the denervation-reinnervation process, with recovery being completed by day 30, whereas the loss in the activity of choline acetyltransferase had not yet completely recovered at this time. The acetylcholinesterase activity localized cytochemically at synaptic sites followed the same trend as the total activity in the iris muscle, whereas acetylcholinesterase localized at myo-muscular junctions showed only slight changes. The acetylcholinesterase molecular forms displayed changes in their relative proportions, which could be related to the time course of the denervation-reinnervation process and to the cytochemical localization of the activity.

Acetylcholinesterase↗