The organisation of the large volume of mammalian genomic DNA within cell nuclei requires mechanisms to regulate chromatin compaction involving the reversible formation of higher order structures. The compaction state of chromatin varies between interphase and mitosis and is also subject to rapid and reversible change upon ATP depletion/repletion. In this study we have investigated mechanisms t...

Using RNA-seq technology, we found that the majority of microRNAs (miRNAs) present in CFU-E erythroid progenitors are down-regulated during terminal erythroid differentiation. Of the developmentally down-regulated miRNAs, ectopic overexpression of miR-191 blocks erythroid enucleation but has minor effects on proliferation and differentiation. We identified two erythroid-enriched and development...

The cysteine proteases known as caspases play a central role in most apoptotic pathways. Here, we show that caspase inhibitors arrest the maturation of human erythroid progenitors at early stages of differentiation, before nucleus and chromatin condensation. Effector caspases such as caspase-3 are transiently activated through the mitochondrial pathway during erythroblast differentiation and cl...

Transmission electron microscopy (TEM) revealed several ultrastructural changes induced by exposure to cadmium in ciliated protozoan, Stylonychia mytilus. The main cytoplasmic alterations in the post treated cells were:-condensation of the ground cytoplasm, mitochondrial disorganization, cytoplasmic vacuolization, accumulation of electron dense bodies and autophagosome formation. At the nuclear...

background: it is estimated that about 50% of causes of recurrent pregnancy loss (rpl) cases remain unknown. sperm factors are suggested to have probable role in cases with rpl. objective: the goal was to determine the possible relationship between semen bacterial contaminations with unexplained rpl. also, the correlation between number of bacterial colony and sperm chromatin condensation was e...

background: exposures to lead above the threshold value of 50–60 μg/dl have been linked to diminished semen quality parameters. worldwide, the lead exposure has been diminished during the last years. therefore, it has become of a great concern to examine the effects of lead exposures on semen quality at low levels of exposure. objective: to evaluate the effect of low level (<20 μg/dl) blood lea...

varicocele is one of the most common causes of primary male infertility. pilea microphylla (pm) is being used as folk medicine. this study was aimed to investigate the effects of pm in a rat model of varicocele. a total of 30 male wistar rats were divided into control, sham, varicocele, accessory varicocele and pm-treated groups. after 10 weeks of varicocele induction, sperm parameters and chro...

We evaluated the effect of varicocelectomy on semen parameters and levels of sperm DNA damage in infertile men. A total of 75 infertile men with varicocele and 40 fertile men (controls) were included in this study. Semen analysis and sperm DNA damage expressed as the DNA fragmentation index using acridine orange staining and chromatin condensation test by flow cytometry were assessed before and...

Human epidermoid tumor A431 cells underwent apoptosis following exposure to ultraviolet C (UVC). The apoptosis was of the interphase death type, and mostly occurred within one cell cycle, independent of the cell-cycle phases. We further examined the detailed sequential order of apoptotic changes in cells after UVC exposure and the involvement of caspases using six caspase inhibitors. The loss o...

Apoptotic execution is characterized by dramatic changes in nuclear structure accompanied by cleavage of nuclear proteins by caspases (reviewed in [1]). Cell-free extracts have proved useful for the identification and functional characterization of activities involved in apoptotic execution [2-4] and for the identification of proteins cleaved by caspases [5]. More recent studies have suggested ...