RESUMEN
The method of kinetic analysis of the relaxation phase of the mechanical response of the smooth muscle previously proposed by Burdyga and Kosterin was applied to study the dynamics of the decay of oxytocin-induced calcium transients in cytosol of the rat myometrium smooth muscle cell detected by a fluorescence signal generated by a calcium-sensitive probe fluo-4 using a laser scanning confocal microscope. The experimental data were well linearized in the coordinates ln [(Fm - F)/F] vs lnt (F and Fm are the current fluorescence intensity of the calcium probe and the fluorescence intensity at the maximum of the calcium transient, respectively, while t is the time). The empirical parameters n and τ were determined by which the maximal normalized relaxation rate Vn was calculated for five different ROIs (regions of interest) in the myocyte cytosol. It proved to be almost the same for all ROIs. The maximal normalized relaxation rate calculated from the fluorescence intensity was always lower than that calculated from the corresponding calcium concentration, i.e. the cytosolic Ca2+ concentration in the relaxation phase decreases faster than the corresponding fluorescence intensity. The value of the maximal normalized relaxation rate calculated both from the fluorescence intensity and from the force of oxytocin-induced contractions of isolated rat uterus longitudinal smooth muscles (according to Tsymbalyuk and Kosterin) was exactly the same. This indicates that in the relaxation phase, the decreasing curves of both the fluorescence intensity and the contraction forces coincide.
Asunto(s)
Músculo Liso/cirugía , Miocitos del Músculo Liso/metabolismo , Animales , Calcio , Femenino , Cinética , Oxitocina , RatasRESUMEN
The aim of the present study was to analyse the preoperative platelet count and the platelet-lymphocyte ratio (PLR) in patients with colorectal cancer (CRC) of different stages and with hepatic metastasis of CRC (mCRC) and to compare these factors as potential prognostic markers. Clinicopathological data of 10 years were collected retrospectively from 336 patients with CRC and 118 patients with mCRC. Both in the CRC and the mCRC group overall survival (OS) was significantly worse in patients who had elevated platelet count (hazard ratio [HR] = 2.2, p < 0.001 and HR = 2.9, p = 0.018, respectively). Multivariate analysis indicated that elevated platelet count was an independent prognostic factor of CRC (HR = 1.7, p = 0.035) and mCRC (HR = 3.1, p = 0.017). Disease-free survival (DFS) was significantly worse in patients with elevated platelet count in the CRC group (HR = 2.0, p = 0.011). In the multivariate analysis the PLR was not a prognostic factor in either of the two cohorts (HR = 0.92, p < 0.001 and HR = 0.89, p = 0.789, respectively). The platelet count is a valuable prognostic marker for the survival in patients both with CRC and mCRC while the PLR is not prognostic in either group.