RESUMEN
Staling of bread was investigated in terms of physico-chemical parameters and one (1D) and two dimensional (2D) 1H Nuclear Magnetic Resonance (NMR) relaxometry. Physico-chemical properties were consistent with those generally reported for bread staling (crumb moisture loss, decrease in frozen water content, formation of amylopectin crystals, crumb hardening). One dimensional 1H NMR investigation suggested the presence of only one T1 protons population, while T2 was representative of multiple proton populations, that well related to the observed physico-chemical changes. 1H Two dimensional NMR provided an interesting insight of 1H T1 dynamics, as it allowed to discriminate the contribution of five protons pools within the 1H T1 relaxation.
Asunto(s)
Pan , Amilopectina , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , AguaRESUMEN
In this study we have explored whether, as a consequence of human papillomavirus (HPV) infection, there is inappropriate expression of estrogen receptor and/or of a small heat shock protein of 27,000 daltons (hsp27). Estrogen receptor, hsp27, and HPV structural antigens were detected by immunocytochemistry, while HPV DNA (6/11, 16/18, 31/35/51) was determined by in situ hybridization in cervical and vaginal samples from 40 patients. Most of the samples with HPV infection without atypia showed a shift in estrogen receptor expression since this protein appeared mainly in the intermediate and superficial cell layers. In the serial sections, these layers displayed strong estrogen receptor staining, together with high HPV replication and late HPV gene expression. In the samples with HPV infection and atypia, estrogen receptors were also frequently found in the basal and parabasal cells, but almost 20% of these samples did not show estrogen receptors. The presence of high estrogen receptor expression was not dependent on a particular HPV DNA type. On the other hand, interesting modifications in hsp27 expression were observed in the HPV-infected tissues. The cytoplasm of the cells with koilocytotic changes showed very low hsp27 content. In several samples this protein appeared in the nuclei of the superficial cells, and sometimes it was also observed in the cytoplasm of the basal cells. These changes in estrogen receptor and hsp27 expression suggest that these proteins might have a role in virus-host biology.