Quantitative label-free digital holographic imaging of cardiomyocyte optical volume, nucleation, and cell division.

Cardiac regeneration in newborn rodents depends on the ability of pre-existing cardiomyocytes to proliferate and divide. This capacity is lost within the first week of postnatal development when these cells rapidly switch from hyperplasia to hypertrophy, withdraw from the cell cycle, become binucleated, and increase in size. How these dynamic changes in cell size and nucleation impact cardiomyocyte proliferative potential is not well understood.

Quantitative Three-dimensional Label-free Digital Holographic Imaging of Cardiomyocyte Size, Ploidy, and Cell Division.

Cardiac regeneration in newborn rodents depends on the ability of pre-existing cardiomyocytes to proliferate and divide. This capacity is lost within the first week of postnatal development when these cells rapidly switch from hyperplasia to hypertrophy, withdraw from the cell cycle, become binucleated, and increase in size. How these dynamic changes in size and ploidy impact cardiomyocyte proliferative potential is not well understood.

Thyroid hormone-dependent regulation of metabolism and heart regeneration.

While adult zebrafish and newborn mice possess a robust capacity to regenerate their hearts, this ability is generally lost in adult mammals. The logic behind the diversity of cardiac regenerative capacity across the animal kingdom is not well understood. We have recently reported that animal metabolism is inversely correlated to the abundance of mononucleated diploid cardiomyocytes in the heart, which retain proliferative and regenerative potential.

Association of perceived parental attitudes towards premarital sex with initiation of sexual intercourse in adolescence.

To assess the association between perceived parental disapproval of premarital sex, quality of the parent-daughter relationship, and initiation of sexual intercourse, a sample of 614 economically deprived female students in Chile were tested. The perception of disapproval of premarital sex by the mother along with a good mother-daughter relationship appears to constitute a buffer against early initiation of sexual activity in adolescence. Results are consistent with findings reported in studies conducted in the USA.