0000000001162552
AUTHOR
David C. Dorn
Apoptosis of male germ-line stem cells after laser ablation of their niche.
AbstractMale germ-line stem cells (GSCs) and their niche-the apical cells or hub cells-display a unique feature at the apices of insect testicular follicles. In the locust, Locusta migratoria, the niche consists of only one large apical cell surrounded by about 60 GSCs. The apical cell can be readily identified in the intact follicle. Using laser ablation it is feasible to destroy the apical cell exclusively without injuring neighboring GSCs or any other cells. The most immediate effect on GSCs is the loss of their structural polarity. Beginning about 3 h after laser treatment chromatin starts to clump and condense in individual GSCs, and some show the first signs of cellular breakdown. The…
Tumor cell specific toxicity of Inula helenium extracts.
The aim of the research program was to identify botanical extracts with antineoplastic activity. In this respect extracts prepared from Inula helenium roots showed a remarkable activity. As evidenced by the MTT assay, the Inula helenium extract revealed a highly selective toxicity toward four different tumor cell lines (HT-29, MCF-7, Capan-2 and G1), but a much lower toxicity against healthy human peripheral blood lymphocytes (PBLs) from two donors. The extract-induced death of tumor cells was studied extensively by electron microscopy. There was a remarkable similarity of morphological alterations observed in the four cell lines: patchy chromatin condensations, cytoplasmic vesiculation, sw…