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Biomedical subjects

S De Luca

Publications and source records attributed to S De Luca.

At least 55 records · Page 3Linked to original sources
PubMed1980

Oligosaccharides on proteoglycans from the swarm rat chondrosarcoma.

Two classes of oligosaccharides were identified in alkaline borohydride digests of monomer proteoglycans from the Swarm rat chondrosarcoma. The first class consists of three similar oligomers, each of which is linked to the proteoglycan core proteins by an O-glycosidic bond between N-acetylgalactosamine and hydroxyl groups on serine and threonine. The structures of the two smallest oligosaccharides are: (formula: see text). Proteoglycan monomers from the chondrosarcoma contain about 1.3 of these oligosaccharides for every chondroitin sulfate chain. Their structures and distribution on the core protein suggest that they are related to the linkage region between keratan sulfate chains and the core protein of cartilage proteoglycans. The second class of oligomers consists of oligosaccharide-peptides that contain mannose and are probably linked to the core protein by N-glycosylamine bonds to asparagine. There appear to be about 15 of these oligosaccharides/ proteoglycan molecule, and they are primarily located on the core protein nearer to the hyaluronic acid-binding site than both the oligosaccharides linked by O-glycoside bonds and the chondroitin sulfate chains. Chondrocytes isolated from the chondrosarcoma and grown in culture synthesize both classes of oligosaccharides.

Acetylgalactosamine↗
PubMedDate not supplied

Fluorescence studies on the binding between 1-47 fragment of cholecystokinin receptor CCK(A)-R(1-47) and nonsulfated cholecystokinin octapeptide CCK8.

The interaction between the 1-47 N-terminus fragment of the cholecystokinin receptor and the nonsulfated cholecystokinin octapeptide, CCK8, is monitored by fluorescence emission. Quenching of the fluorescence intensities is observed on binding. Dissociation constants calculated by these data are in the same submicromolar range as found for the binding of linear CCK8 analogues to B-type receptors. Although detailed structural information cannot be obtained, fluorescence emission is more sensitive than other techniques and permits fast detection of receptor-ligand interaction.

Amino Acid Sequence↗
PubMedDate not supplied

Synthesis and biological activity of pseudopeptides inhibitors of Ras farnesyl transferase containing unconventional amino acids.

A study was performed on the structure-activity relationships of a series of phenol derivatives, CVFM analogs, derived from the two most active compounds of a first series (1A and 1B) of inhibitors of Ras farnesyl transferase (FTase) that we have recently described. We report the synthesis and the activity of a second series of compounds in which the phenylalanine residue was replaced by unconventional aromatic and non-aromatic amino acids, with varying electronic, lipophilic, steric and conformational properties. The compounds showed to be significantly less active than reference compounds against FT, with the only exception of derivative 3A (IC50 = 3 microM), which is slightly more active than 1A but not 1B. Subsequently we tested the effects of compounds 1A, 1B and 3A, 3B on the anchorage-dependent growth of two epithelial cell lines of rats, FRTL-5 and the same line v-Ha-ras transformed. Compound 3A derived from lead compound 1A, showed an appreciable selectivity against transformed cells. In contrast, compounds derived from derivative 1B had only a modest cellular activity.

Alkyl and Aryl Transferases↗
PubMedDate not supplied

Effectiveness of a 23-valent polysaccharide vaccine in preventing pneumonia and non-invasive pneumococcal infection in elderly people: a large-scale retrospective cohort study.

This retrospective cohort study evaluated the effectiveness of a 23-valent pneumococcal polysaccharide vaccine in reducing hospital admission for pneumonia, otitis media and exacerbation of asthma or other syndromes due to Streptococcus pneumoniae in 9170 high-risk individuals. Cohort members were followed from 1 January 1998 to 31 December 2002. With regard to preventing hospitalization due to pneumonia, we observed a decrease in the incidence of 1/10000 person-months and a reduction in the relative risk of 38% in the vaccinated cohort compared with the non-vaccinated subjects. A decrease in the risk of hospital admission for asthma, acute otitis media, chronic obstructive pulmonary disease and other respiratory infections was also observed in vaccinated compared with non-vaccinated subjects. The specificity of these findings was confirmed by the lack of a protective effect from vaccination for those outcomes, such as hospitalization 'for all causes' and 'other otorhinolaryngological diagnoses', that were not directly related to pneumococcal disease.

Adolescent↗
PubMedDate not supplied

[Primary aorto-enteric fistula].

Aorto-enteric fistula, i.e. communication between the aorta and the digestive tract, is a clinical condition that usually appears in patients who have already been submitted to aneurismectomy. Primary fistula, in patients not submitted to surgical treatment, is uncommon. The authors describe a case of primary aorto-enteric fistula which was diagnosed and operated on early, with a favourable outcome. The critical analysis of the authors' experience and the literature data stress that an early diagnosis and suitable therapy can reduce mortality.

Aged↗
PubMedDate not supplied

[Considerations about health risk management].

From the birth of doctrines of Risk Management to today a lot of time is passed. From the initial application in the field of the insurances and the management of the enterprises, theories inspired to the identification, evaluation and correction of connected risks to the activity and the industrial trial has been figurative to the health, field in which the application of these principles results to be how much never profit and productive of benefits above all for the patients that suffer consequences of errors but also for the physicians and the personnel that, perfectly inserted in an organization aware of the trials to put into effect, can bring their contribution to underline the weak points of the relief trial. The economic cost and consequences of errors can decrease if a new culture is established inspired to the learning and the communication of the adverse events, to minimize the possibility that they again occurs.

Risk Management↗