RESUMO
The expression of laminin-1 chains (beta1 and gamma1), laminin-2 (merosin), integrin receptors to laminin (alpha3beta1 and alpha6beta4) and cytokeratin (CK20) were studied by immunohistochemical methods in gastric biopsies from antrum of 25 patients. H. pylori gastritis was found in 19 cases and intestinal metaplasia (IM) in four from these 19. Another 13 biopsies, all with IM were immunostained to laminin-2. Laminin-1 chains in normal and gastritis areas without IM were expressed as a strong, linear and continuous deposit in the basement membranes of the superficial and glandular epithelium. In metaplastic glands the reactivity to laminin-1 chains was decreased. Merosin was discontinuous when a moderate to accentuated H. pylori glandular colonization was present. Samples with IM were negative to laminin-2. The alpha3beta1 and alpha6beta4 integrins were negative only in IM gastric biopsies. The CK20 immunoreactivity was strong and homogeneous in the cells at the tip and the upper portion of foveolae in normal areas and in gastritis with IM the reactivity to CK 20 was heterogeneous. A differential expression of laminin isoforms is related to inflammation and subsequent IM caused by H. pylori. The alterations of alpha3beta1 and alpha6beta4 parallel both modifications in merosin and CK20 expression in H. pylori chronic gastritis.
Assuntos
Antígenos de Superfície/biossíntese , Gastrite/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Integrinas/biossíntese , Proteínas de Filamentos Intermediários/biossíntese , Laminina/biossíntese , Receptores de Laminina/biossíntese , Adulto , Idoso , Anticorpos Monoclonais , Matriz Extracelular/metabolismo , Feminino , Imunofluorescência , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Imuno-Histoquímica , Integrina alfa3beta1 , Integrina alfa6beta4 , Queratina-20 , Masculino , Pessoa de Meia-IdadeRESUMO
A flow set-up based on the sequential injection analysis concept was designed, aiming at increased automation and robustness of procedures related with potentiometric detection in pharmaceutical control. In this sense, programmable set-up calibration, ion-selective electrode characterization, standard addition techniques and titration procedures could be carried out without any stock solutions conventional handling or modification on the physical structure of the flow system. Evaluation of a flow-through vitamin B6 selective electrode and its application to routine analysis of pharmaceuticals were selected as models to demonstrate the system potentialities. The system ability to generate in-line calibrating solutions was verified by comparing the results with those obtained with solutions prepared by the manual procedure. The vitamin B6 determination in pharmaceutical products was carried out and in-line performed recoveries gave values within 97.4-103.5%. The system ability to perform titrations was ascertained using the precipitation reaction of vitamin B6 with tetraphenylborate. Other profitable features such as lower reagent consumption with a low effluent generation volume were also achieved.
Assuntos
Preparações Farmacêuticas/química , Piridoxina/análise , Calibragem , Eletrodos , PotenciometriaRESUMO
We determined the effect of the extent of protein polymerization on the intestinal hyperplastic adaptation of adult male Wistar rats after 80% resection of the jejunal-ileal segment. Rats received one of four chemically defined solid diets prepared by using casein, two casein hydrolysates of different peptide size distributions, or free amino acids simulating casein and identical in all other components for 12 d, starting 3 d after surgery. Semipaired feeding was used to ensure that the same quantity of food was ingested by each group and as a consequence, nitrogen and energy intakes were reduced to 63% of that obtained with ad libitum feeding of the casein diet to intact rats. No significant differences were demonstrable in food ingestion, weight gain, nitrogen balance, or morphometric data for the remaining jejunal and ileal segments (number of cells/villus, number of cells/crypt, and crypt cell mitosis rate). These data demonstrate that the extent of polymerization of the protein nitrogen source did not affect the hyperplastic adaptative process of the rat. Additional studies in humans are necessary to determine whether intact protein diets can be used first as a nitrogen source in nutritional support of patients with a nonspecific hyperplastic response to surgical resection before the use of expensive hydrolysates and the more expensive amino acid mixtures.