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A Del Vecchio

Publications and source records attributed to A Del Vecchio.

44 records · Page 3Linked to original sources

Misleading results in studying pharmacodynamic interaction with oral anticoagulants.

An experimental conditions is described in which the i.p. administration to rats of irritants produces a misleading increase of the anticoagulant effect of warfarin. Groups of 10 adult Wistar rats were treated i.p. or i.v. with HCl 0.1N plus warfarin p.o.; 24 hr after warfarin administration, prothrombin time was determined on citrate blood specimens and the animals were submitted to autopsy. When HCl is given i.p., a significant increase of prothrombin time is observed. On the contrary following i.v. administration no interference with the anticoagulant effect of warfarin is observed. Abdomen exploration of rats shows the presence of serum exudate following i.p. but not i.v. administration of HCl. The synergistic effect of i.p. administration of HCl on anticoagulant effect of warfarin appears an experimental artifact, probably attributable to a non-specific local irritating effect. This result stresses the need of caution in interpreting animal data indicating a synergism with oral anticoagulants.

Animals↗

Depressant action of oxybutynin on the contractility of intestinal and urinary tract smooth muscle.

Experiments were carried out in-vitro using segments of guinea-pig ileum, taenia caeci, ureter and detrusor. In the ileum, oxybutynin (30, 100 nM) competitively antagonized acetylcholine-induced contractions but did not alter those induced by histamine. Higher concentrations of oxybutynin (up to 10 microM) induced a non-competitive depression of responses to both agonists and caused a parallel shift to the right of the Ca2+-induced contractions in taenia caeci strips bathed in a Ca2+-free, high-K+ medium. In the ureter, oxybutynin (1-10 microM) impaired rhythmic muscular contractions in normal medium and after CaCl2 addition in Ca2+-free medium. Similarly to verapamil (10, 30 microM), oxybutynin (10, 30 microM) depressed both the cholinergic and non-adrenergic, non-cholinergic components of the electrically-induced contractions of detrusor strips. It is concluded that oxybutynin has anticholinergic properties and, at higher concentrations, exerts a direct spasmolytic activity possibly mediated by blockade of the transmembrane Ca2+ fluxes responsible for smooth muscle contraction.

Acetylcholine↗

Scintigraphic evaluation of gastroesophageal reflux in newborns.

OBJECTIVES: This study was carried out to verify whether during neonatal stage gastroesophageal scintigraphy, may be useful not only to diagnose gastroesophageal reflux (GER), but also to detect pulmonary aspiration, at times responsible for respiratory symptoms frequently associated with GER. PATIENTS AND METHODS: Gastroesophageal scintigraphy was performed on 50 newborns admitted to NICU of Brindisi in the last two years who presented symptoms as cyanosis, apnoea, bradycardia, laringeal stridor, wheezing, not related to respiratory or cardiac problems, but suspected to be clinical suggestive symptoms of "pathological" GER. After administration of 99mTC mixed with the usual meal formula, we obtained a recording period of 60-90 minutes and a later recording at 4 and 24 hours to document radioactive material in lungs. RESULTS: Scintigraphy showed GER in 40/50 cases and despite frequent observation of respiratory symptoms (39/40 cases) in these newborns never radiation in pulmonary fields. CONCLUSIONS: Our results could indicate that scintigraphy, noninvasive and low in radiation, may be considered effective and reliable to diagnose GER in newborns. The absence of radiation in pulmonary fields could indicate that respiratory symptoms frequently associated with GER could depend on involuntary mechanism of vagal type and not on pulmonary aspiration.

Bradycardia↗

[Osteomas and exostoses of the facial structures: a morphological study and the etiopathogenetic considerations].

The differential diagnosis of the osteocondensing lesions (osteomata and exostoses) is till today a topical issue for the experts. In order to test the reliability of the etiopathogenetic theories advanced up to now, the authors carried out a research on samples of tissue coming from surgical interventions for osteomata and exostoses of the maxillofacial region resortied with optical and polarized-light microscopes (OM-PLM). This research meant to analyze the morphological and structural characteristics of newly formed tissues; a considerable attention has been devoted to the difference between primary and secondary bone and to the quality of cementing lines. Thanks to the data resulted from this study, the authors advanced interesting theories about these pathologies either from an etiological and nosological point of view.

Diagnosis, Differential↗