Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

Sindrome da cimitarra. / Scimitar syndrome

Os autores apresentam um caso de sindrome da cimitarra considerando a sua raridade e principalmente a associacao com hernia diafragmatica direita. Tem um estudo radiologico documentando o caso e a descricao cirurgica com fotografias que identificam os achados cirurgicos da sindrome da cimitarra

Investigations on site effects in Italy

Amplitude variations among atrong ground motions recorded at close sites and anomalies of the macroseismic fields were observed in Italy on the occasion of recent earthquakes. We present results for three sites where amplifications of ground motion larger than a factor of ten were experienced, or a difference of one intensity degree compared with nearby sites was observed. Moreover, some experiments were carried aut on sediment bodies in order to investigate site response, based on measurements of weak motions produced by teleseisms, local earthquakes and explosions. For all these study case, 1- and 2-D numerical techniques and microtremorFourier spectra were used to compare theoreticaland empirical estimations. Generally, numerical medelling allowed a good prediction of the frequency band where amplifications accur, but a satisfactory fit of amplifications observed during earthquakes was obtained in some cases only (AU)

Recent seismic activity and earthquake occurrence along the Apennines

In this paper we analyze the seismicity along the Apennines in order to relate the seismicity pattern to the seismogenic environment and to the active tectonic processes. The analysis of crustal and subcrustal seismicity show that the northern and southern Apennines are characterized by two distinct patterns of seismicity. These two domains are separated by two important lithological discontinuities (the Ancona - Anzio and the Ortona - Roccamonfina lines). The seismicity along the Apennines is mainly concentrated in a narrow belt running along the chain, with an evident geometrical offset which corresponds to the Ancona-Anzio line. We discuss these observations considering both the seismological evidence and the present tectonic regime in which the earthquakes occur. We focus on the southern Apennines, where the largest earthquakes (6 ó M ó 7.0) have occurred. We analyze the main features of some recent seismic sequences in order to discuss the seismicity patterns in terms of the hypothesis of segmentation of the southern Apennine seismogenic belt. This work aims to be a preliminary contributions to the important goals of understanding the spatial and temporal patterns of seismicity and of identifying active faults