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Biomedical subjects

A Morelli

Publications and source records attributed to A Morelli.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

[Posterior mediastinum neoplasms: a case of schwannoma].

The Authors report the case of a 33-year-old male affected with an asymptomatic schwannoma of the posterior mediastinum, and review the relevant Literature, discussing the difficulties in making the differential diagnosis of the posterior mediastinum lesions, particularly in the pre-clinical phase. Neurogenic tumors represent about 75 percent of all tumors of mediastinum and about one third of all tumors of the mediastinum. They can originate from the peripheral nervous system group, from the sympathetic nervous system group or, in rare cases, from the vagus nerve. In adult patients, they are usually found by chance during radiographic examination of the thorax, and they are usually asymptomatic and benign. During preoperative evaluation, a magnetic resonance examination of rachis should be done to exclude the possibility of intraspinal involvement. If there are no contraindications, the treatment of choice should be surgical resection by means of thoracoscopy or thoracotomy, when size and location of the tumors allow it in order to prevent malignant evolution.

Adult↗
PubMedDate not supplied

Endoscopic treatment of bile duct stones.

Approximately fifteen per cent of patients who undergo gallstones also have concomitant common bile duct stones. Endoscopic papillosphincterotomy (EPS) is the treatment of choice for common bile duct stones in cholecystectomized patients as well as in patients with gallbladder in situ but at high operative risk. Endoscopic papillosphincterotomy is a highly effective technique and able to remove stones from choledochus in 85-90% of cases. The failure of EPS is mainly related to the size of stones (greater than 15 mm). However, recently introduced sophisticated techniques, such as extraluminal (extracorporeal shock wave lithotripsy) or intraluminal lithotripsy (mechanical, electro-hydraulical or laser) now allow to fragment and remove also "large" stones. Should EPS fail to remove stones, a naso-biliary tube can be endoscopically positioned and attempts made to dissolve the stone by infusing chemical solvents. However, until now the chemical dissolution has only a marginal efficacy in the treatment of common bile duct stones. If all these techniques fail, good operative risk patients can be treated by surgical choledochotomy, while high operative risk patients can be treated by permanent biliary endoprosthesis or percutaneous techniques.

Acute Disease↗
PubMedDate not supplied

[Changes in upper gastrointestinal motility during scleroderma].

Scleroderma (progressive systemic sclerosis) is a systemic collagen disease in which the upper gut is frequently involved. In particular, most patient show altered esophageal motility, which frequently result in severe esophagitis, often resistant to therapeutic measures. The small bowel is also frequently involved by the disease, especially in the late stage of scleroderma. Small bowel alterations are sometimes clinically silent, but can also be the origin of malabsorption syndrome, small intestine perforation, pneumatosis cystoides or chronic intestinal pseudo-obstruction. The occurrence of an altered gastrointestinal motility in scleroderma can be detected by means of manometric techniques; their use in the wide area of collagenopathies may help understanding the pathophysiology of the altered gastrointestinal function frequently existing in these diseases.

Esophagus↗
PubMedDate not supplied

Effect of triiodo-L-thyronine treatment on Ca2+ sequestration in rat liver microsomes.

T3 administration to rats exerts quite different effects on enzyme activities associated to liver microsomal membranes such as G-6-Pase, Mg ATPase and Ca2(+)-dependent ATPase: in fact G-6-Pase activity is significantly enhanced, Mg ATPase is not affected whereas Ca2(+)-dependent ATPase is drastically inhibited. The T3 induced decrease in Ca2(+)-dependent ATPase activity is associated with a net reduction (to about 50% with respect to controls) of the Ca2+ sequestration in liver microsomal vesicles. The enhanced level of inorganic phosphate in the endoplasmic reticulum due to the stimulation of G-6-Pase activity does not significantly affect the uptake of calcium in microsomal vesicles. The decreased Ca2(+)-dependent ATPase activity is associated to an enhanced level of the enzyme in the phosphorylated form (E-P). This suggests that in liver preparations from T3 treated rats the turnover of ATP and cleavage of E-P is reduced, thus resulting in the accumulation of the phosphorylated intermediate. The accumulation of E-P is in agreement with the inhibition of the calcium sequestration since the active transport of this cation in microsomal membranes requires the hydrolysis of the E-P complex.

Animals↗
PubMedDate not supplied

Human erythrocyte glucose 6-phosphate dehydrogenase. Influence of coenzyme derivatives on thermostability and kinetic properties.

A number of derivatives of NADP(H) were tested with respect to their effectiveness in interacting with tetrameric glucose 6-phosphate dehydrogenase (G6PD) retaining only the fraction of "structural" coenzyme (4 moles NADP). Interaction was probed by two parameters: a) increased thermostability of G6PD activity, measured as the difference in the corresponding transition temperature (Tm) of samples containing and lacking the NADP derivatives, respectively; b) competitive inhibition toward NADP, expressed a Ki values. Protection afforded by the various effectors against thermal denaturation decreased in the following order: NADPH, NADP, PADP-ribose, adenosine 2',5'-P2. Other NADP derivatives, including 2',3' cyclic NADP, NMN, NMNH, nicotinamide, adenosine 2'-P, were uneffective in respect to this property. The kinetically measured affinity was the greatest for NADPH and decreased progressively for the following effectors: PADP-ribose, NADP, NMNH, PADP-glycolaldehyde, adenosine 2',5'-P2, PADP-ribitol, adenosine 2'-P. Nicotinamide and NMN were uneffective on NADP binding. These data show that the adenosine moiety of NADP is more critically involved than the nicotinamide portion in the interaction with human G6PD.

Drug Stability↗
PubMedDate not supplied

[Control using omeprazole in a case of upper digestive hemorrhage, induced by erosive uremic hemorrhagic gastritis resistant to conventional therapy].

Erosive and/or ulcerative lesions of the digestive tract often complicate chronic renal failure. These lesions usually cause only chronic bleeding. In the rare cases of massive digestive bleeding, conventional therapy is frequently unsatisfactory. A case of massive bleeding, due to anti-H2 therapy resistant erosive haemorrhagic uremic gastritis is reported, where repeated transfusions failed to correct a marked anaemia (Hb = 0.8 g/dl). Considerable improvement of the endoscopy, clinical and hemato-biochemical pictures was achieved with 40 mg/day omeprazole. Three-months follow-up confirmed the efficacy and safety of the drug.

Female↗
PubMedDate not supplied

Detoxifying activities in alveolar macrophages of rats treated with acetylcysteine, diethyl maleate and/or aroclor.

Single or sequential treatment of rats with the thiol N-acetyl-L-cysteine (NAC), the glutathione depletor diethyl maleate (DEM) and the enzyme inducer Aroclor 1254 (AR) produced several significant variations on metabolic activities of pulmonary alveolar macrophages (PAM). Specifically, all three compounds elicited an increase in some oxidoreductase activities, including the two dehydrogenases involved in the hexose monophosphate shunt (G6PD and 6PGD) and NADH- or NADPH-dependent diaphorases. Diaphorase activities were especially increased by sequential treatments with AR and DEM or with DEM and NAC. Both NAC and AR also stimulated other detoxifying mechanisms, such as those related to GSH S-transferase activity and to the NADPH-dependent reduction of hexavalent chromium. Therefore, all the monitored parameters were significantly enhanced not only by the enzyme inducer, but also by the thiol, demonstrating its protective role in the biotransformation of mutagenic/carcinogenic compounds.

Acetylcysteine↗