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Biomedical subjects

S De Maria

Publications and source records attributed to S De Maria.

7 recordsLinked to original sources
PubMed1999

Evidence for multiple rat VPAC1 receptor states with different affinities for agonists.

We compare the binding properties of [125I-VIP] and [125I]-Ro 25 1553 to VPAC1 receptors, expressed in stably transfected CHO cells. [125I]-VIP labelled two VPAC1 receptor states, while [125I]-Ro 25 1553 labelled selectively a limited number of high-affinity receptors. This high-affinity state probably corresponds to an agonist-receptor-Gs ternary complex as its properties (guanyl nucleotides, EC50 values and maximal effect) were affected by cholera toxin pre-treatment. Both high- and low-affinity receptors participated in the adenylate cyclase activation. This suggested that agonists activate not only low-affinity uncoupled receptors by facilitating the ternary complex formation, but also activated the high-affinity ternary complex by accelerating the GTP binding to emptied, receptor-bound G proteins.

Animals↗
PubMed1999

Enzymatic synthesis of vasoactive intestinal peptide analogs by transglutaminase.

Vasoactive intestinal peptide is an amino acceptor and donor substrate for tissue transglutaminase (TGase) in vitro. This peptide contains a single glutamine residue, Gln16, which was identified as the amino acceptor substrate. Different gamma(glutamyl16)amine derivatives of vasoactive intestinal peptide were synthesized enzymatically in vitro. The modification is very fast when compared with that of many native substrates of TGase. The analogs 1,3-diaminopropane, putrescine, cadaverine, spermidine, spermine, glycine ethyl ester and mono-dansylcadaverine of the peptide were purified by high-performance liquid chromatography on a reverse-phase column and were analyzed by electrospray mass spectrometry. When amines were absent in the assay mixture as an external amino donor, lysine residue occurring in the peptide was an effective amino donor site for TGase. Only one of the three lysine residues of vasoactive intestinal peptide, namely Lys21, was demonstrated to be involved in both inter- and intramolecular cross-link formation.

Amines↗
PubMed1981

Constipation and obesity: a statistical analysis.

Constipation frequency was investigated among 1897 subjects (874 males and 1023 females), ranging in age from 6 to 70 years, chosen at random between city inhabitants and farmers. Bowel habit was studied in 966 obese patients (390 males and 576 females). The authors followed for the diagnosis of constipation either the commonest and restrictive criterion of the weekly bowel actions or the clinical one which implies also others parameters, like hard or small stools, difficulties of expulsion or feeling of incomplete evacuation after defecation. The statistical analysis showed that constipation frequency is 8.3% in obese patients and 1.5% in normal-weighting, according to weekly bowel actions criterion: the difference is statistically significative (p less than 0.001).

Adolescent↗
PubMed1981

Blood glycerol meaning in obese patients.

The authors studied the behaviour of blood glycerol concentration after glycerol i.v. infusion in obese and normal subjects. The aim of research was to clarify the meaning of blood glycerol increase observed by some one in obese subjects. Results obtained showed that in obese subjects there is not any abnormal behaviour of blood glycerol concentration after infusion and that in none of patients studied was observed any significative increase of basal blood glycerol concentration values.

Adult↗