Biomedical subjects

A Lentini

Publications and source records attributed to A Lentini.

At least 55 records · Page 3Linked to original sources

PubMed1991

[Anastomosis or closure of the pancreatic stump after duodenopancreatectomy?].

From 1986 to June 1990, 10 pancreaticoduodenectomies were performed in our Department (VIII Patologia Chirurgica, Università "La Sapienza", Roma). The reconstructive sequence was based on the pancreaticojejunal anastomosis (2 end-to-end pancreaticojejunostomies after invagination, 3 end-to-side Wirsung jejunostomies) in 5 patients. The pancreatic stump was sutured using a 50mm linear stapler in the remaining 5 patients. There was a high incidence (75%) of fistulization after direct suture of the pancreatic stump, although related mortality was null. Among patients treated with pancreaticojejunal anastomosis, a fistula on the end-to-end pancreaticojejunostomy with exitus of the patient, was registered in 1 case. On principle, we believe a end-to-side Wirsung jejunostomy should be performed after pancreaticoduodenectomy. When a safe anastomosis of the pancreatic stump cannot be performed (because of the soft parenchyma, easily lacerable) the technique of the direct suture with stapler is advisable.

Adenocarcinoma↗

PubMed1991

[Reconstructive microsurgery].

Progress in microsurgery has been accomplished by the technical improvements of the operative microscope and other delicate surgical instruments. Therefore, even small arteries as well as female tuba and male deferens, either presenting mechanical obstruction or a section, can be reconstructed. The same procedure may be applied in case of nerve injuries. Since Microsurgery was born, it has been employed in different medical fields offering lately good chances in sterility. Furthermore, microsurgical techniques offer a great support to Plastic Surgery. In fact, it is possible to repair wide tissue damages of the skin, muscles or bones using free flaps. The percentage of success of this Surgery increased the overall percentage obtained in General Surgery. Therefore a close multidisciplinary relation between the different Medical fields is absolutely required for a correct application of microsurgical techniques.

Adolescent↗

PubMed1990

Binding and uptake of ligands for mannose-specific receptors in liver cells: an electron microscopic study during development and aging in rat.

The binding and uptake of mannose exposing ligands in rat liver cells during development and aging was studied. The mannose-specific receptors are visualized using 5-nm diameter colloidal gold particles coated with invertase or mannan. It was found that the binding sites are present on sinusoidal liver cells since prenatal life but their quantitative and qualitative cell surface expression changes with age. The number of receptors affects the endocytotic capacity of Kupffer cells which is low during perinatal and aging periods and reaches the values of adult animals between the 11th and the 15th day after birth. Our results indicate that the expression and the activity of mannose-specific receptors on sinusoidal rat liver cells is related to the differentiative stage of the organ.

Aging↗

PubMed1987

Synthetic inhibitors of human leukocyte elastase, Part 3. Peptides with alkyl groups at the N- or C-terminus. Non-toxic competitive inhibitors of human leukocyte elastase.

A series of carboxy-alkylamidated and N-acetylated amino acids and peptides were synthesized and examined for their ability to inhibit human leukocyte elastase. The Boc-amino acid alkylamides were found to be potent specific and competitive inhibitors of this enzyme. They were found not to or only poorly inhibit several other serine proteinases such as bovine trypsin, alpha-chymotrypsin, porcine pancreatic elastase and human leukocyte cathepsin G at concentrations less than 10(-4) M. Specificity and maximum inhibition of human leukocyte elastase were achieved when the N-terminus of the amino acid was protected by a t-butyloxy-carbonyl (Boc) group, the oligopeptide fragment consisted of valine residues and when the alkyl chain was between 10 and 12 carbon atoms in length and attached to the C-terminus of the peptide fragment. Highest inhibition was obtained with the compound Boc-[Val]3-NH[CH2]11--CH3 (Ki = 0.21 microM). These specific inhibitors were also found to be non-toxic after oral administration to mice and rats (LD50 greater than 3.0 g/kg body weight).

Amino Acids↗

PubMed1987

Synthetic inhibitors of human granulocyte elastase, Part 4. Inhibition of human granulocyte elastase and cathepsin G by non-steroidal anti-inflammatory drugs (NSAID)s.

A series of non-steroidal anti-inflammatory drugs (NSAIDs) and some of their metabolites were evaluated for their ability to inhibit the proteolytic activity of human granulocyte elastase (HGE) and cathepsin G (HGC-G). The enzyme activity was monitored using specific synthetic chromogenic substrates. The results obtained indicated that phenylbutazone, sulindac, piroxicam and gold sodium thiomalate significantly inhibited HGE (Ki less than 0.5 mM), while only sulindac, diflunisal and gold sodium thiomalate were effective inhibitors of HGC-G (Ki less than 0.4 mM). Studies on metabolites of some of the NSAID tested were found to be superior inhibitors of both HGE and HGC-G than the parent molecules. Moreover, of the 18 compounds examined, the major metabolite of sulindac, sulindac sulphide was the most potent inhibitor of HGE (Ki = 0.01 mM) and HGC-G (Ki = 0.15 mM).

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1985

Synthetic inhibitors of human leukocyte elastase Part 1--Sulphated polysaccharides.

Ten dextran sulphates and six chitosan sulphates of variable Mr and extent of sulphate substitution have been examined for their ability to inhibit human leukocyte elastase (HLE). All were potent partial non-competitive inhibitors of this enzyme, highest activity being obtained with compounds of large molecular weight and maximum sulphate incorporation (Ki = 5.0 X 10(-10)M]. In all cases, the dextran sulphates were more effective inhibitors than chitosan sulphates of similar size and charge, but both classes were inactive against bovine trypsin, chymotrypsin and porcine pancreatic elastase at concentrations less than 10(-4)M. The data suggest that drug binding to HLE occurs by stereospecific electrostatic interactions at site(s) removed from the catalytic reaction centre.

Chitin↗

PubMed1983

The interaction of pentosan polysulphate (SP54) with human neutrophil elastase and connective tissue matrix components.

The binding of pentosan polysulphate (SP54) to human polymorphonuclear leucocyte elastase (PMNE) and some of its natural and synthetic substrates has been investigated. Using an ion exchange (DE52) assay system the binding of SP54 to PMNE was found to be 100 times stronger than to collagen or proteoglycan (PG). While the order for in vitro binding of the drug to purified substrates was found to be PG greater than gelatin greater than type I collagen, in vivo experiments indicated that SP54 was localized in tissues rich in collagen. Using gel-exclusion chromatography it was shown that these tissues also contained proteinaceous components other than PG and collagen which interacted with SP54. These results indicate that the potent inhibitor activity of SP54 against PMNE (50% inhibition at 1.7 X 10(-7)M) probably occurs by a specific interaction with the enzyme rather than by substrate binding inhibition, although the latter interaction may be important for localising the drug in these tissues.

Cartilage, Articular↗

PubMed1968