ALBERT

Description: Telomeres (TLs) protect chromosome ends from chromosomal fusion and degradation, thus conferring genomic stability, and play crucial roles in cellular aging and disease. Recent studies have found a correlation between environmental, physiological and even mental stresses on TL dynamics in humans. However, the causal relationship between stress and TL length and the molecular mechanisms underlying that relationship are far from being understood. This study describes the effect of moderate concentrations of ethanol, equivalent to social drinking, on human TL dynamics and partially elucidates the mechanism mediating this effect. The exposure of Immortalized human foreskin fibroblast, primary human foreskin fibroblast and human hepatocellular carcinoma cells to 25 mM ethanol for one week moderately shortened telomeres in all cells. Similar TL shortening was obtained following cells’ exposure to 25 µM acetaldehyde (AcH) and to a much lower extent after exposure to 4-methylpyrazolean, an inhibitor of alcoholdehydrogenase, suggesting that AcH plays a key role in ethanol-dependent telomere shortening. Telomerase activity was not involved in this effect. TRF2 and several TRF2 binding proteins increased their binding to TLs after ethanol treatment, implying their involvement in this effect. The methylation status of several sub-telomeric regions increased in response to EtOH exposure. Gene expression profiling showed distinct patterns in cells treated with EtOH and in cells recovered from EtOH. In addition to cellular ageing, the described telomere shortening may contribute to the carcinogenic potential of acute alcohol consumption; both are associated with the shortening of TLs and provide new insights regarding the moderate consumption of alcohol referred to as “social drinking.”

Description: Surface pyroelectricity and piezoelectricity induced by water incorporation during growth in α-glycine were investigated. Using the periodic temperature change technique, we have determined the thickness (~280 µm) of the near surface layer (NSL) and its pyroelectric coefficient (160 pC/(K × cm2) at 23 °C) independently. The thickness of NSL remains nearly constant till 60 °C and the pyroelectric effect vanishes abruptly by 70 °C. The piezoelectric effect, 0.1 pm/V at 23 °C measured with an interferometer, followed the same temperature dependence as the pyroelectric effect. Abrupt disappearance of both effects at 70 °C is irreversible and suggests that water incorporation to α-glycine forms a well defined near surface phase, which is different form α-glycine because it is polar but it too close to α-glycine to be distinguished by X-ray diffraction (XRD). The secondary pyroelectric effect was found to be