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R V Soares

Publications and source records attributed to R V Soares.

11 recordsLinked to original sources

MG2 and lactoferrin form a heterotypic complex in salivary secretions.

Protein-protein interactions are necessary for homeostasis to be maintained and for biological systems to be integrated. Heterotypic complexes occur in saliva, and a complex between MG2 and SIgA has been suggested to promote microbial clearance from the oral cavity. In this study, we used a peptide display library to investigate previously unrecognized heterotypic complexes involving MG2 and other proteins. The library was panned with MG2 12 times, and analyses of clones identified the sequence Ala-Leu-Leu-Cys-, which occurs in salivary lactoferrin. Blotting experiments confirmed that MG2 and lactoferrin form a heterotypic complex in vitro and in vivo. Periodate treatment of MG2 did not affect the interaction. A synthetic lactoferrin peptide containing the motif Ala-Leu-Leu-Cys-blocked the interaction between MG2 and lactoferrin, confirming the specificity of the interaction identified by panning. This complex may enhance the properties of these salivary components in the oral environment.

Adult↗

The effects of duration and intensity of stimulation on total protein and mucin concentrations in resting and stimulated whole saliva.

The present investigation has characterized the influence of the duration and intensity of stimulation on the secretion pattern of total protein and salivary mucins MG1 and MG2 in whole saliva. Resting and stimulated whole saliva was collected from six healthy subjects on 2 consecutive days. Whole saliva was collected for 2 five-minute intervals under resting conditions followed by collection under masticatory stimulation induced by the chewing of parafilm (1 g) at 10 or 60 strokes/min for 15 min. Flow rates were different under the 2 levels of stimulation. The concentration of total protein was different in resting and stimulated whole saliva but was not affected by the duration or intensity of stimulation. Analysis of mucin concentrations determined by capture ELISAs revealed that the pattern of MG1 secretion was similar to that of total protein. The pattern of MG2 secretion was unique in that no differences were observed in the concentration of this mucin under resting and stimulated conditions. This study shows that the pattern of protein secretion in whole saliva does not reflect the combined pattern observed for protein secretion in parotid and submandibular/sublingual glands, and that the secretion patterns of MG1 and MG2 in whole saliva are quite different from one another.

Adult↗

Prevalence of gallstones in a Brazilian population.

The objective of the present study was to determine the prevalence of gallstones in the population of Curitiba, Brazil. A total of 1000 persons was randomly recruited among individuals who were visiting two shopping centers of the city in order to represent the Brazilian population in relation to age and sex. The selected people underwent ultrasonographic examination of the upper abdomen immediately after a medical interview. Of the 1000 persons evaluated, 93 (9.3%) had gallstones (64 persons) or had been subjected to cholecystectomy due to cholelithiasis. The gallstone prevalence increased from 2.4% in persons of 20-29 years of age to 27.5% in persons of more than 70 years (chi2 = 37.29; P <0.001). The prevalence was 2.4 greater in females (12.9%) than in males (5.4%) (chi2 = 16.34; P <0.001). The prevalence increased with the number of pregnancies from 4% in nulliparous women, to 34.6% in persons with a history of six or more pregnancies (chi2 = 200.1; P <0,001). The prevalence also increased according to the body weight (chi2 = 30.08; P <0.001). There was no difference in the prevalence between individuals with diabetes mellitus and controls. It is concluded from this study that the prevalence of gallstones in the city of Curitiba is elevated.

Adult↗