The morphological characteristics of apoptotic cells are a decrease in cell volume; condensation and fragmentation of the nuclei; and fragmentation of the cell into small bodies that remain surrounded by plasma membranes (Figure 1). Not all apoptotic cells exhibit these morphological features. This fact makes it difficult to determine the number of apoptotic cells in tissue specimens. Furthermore, apoptotic bodies have a short lifespan because they are readily eliminated by macrophages and/or neighbouring cells. Some of the best pathological examples of apoptosis can be observed in cases of chronic hepatitis C and B (Figure 2).
Figure 1) Schematic depiction of the morphological characteristics of the apoptotic process. The first step is characterized by a reduction in cell volume associated with the condensation of nuclear chromatin and the formation of membrane blebs (A). The next step occurs when cells become fragmented and apoptotic bodies, which may or may not contain nuclear residues, can be identified (B). These fragments are eventually phagocytosed by macrophages or neighbouring cells (C)
Figure 2) Representative photomicrographs of liver tissue from a hepatitis C-infected patient. The liver section was stained with hematoxylin-pMoxin-safranin. A High-power view showing the morphological characteristics of apoptosis. The arrow shows a small, acidophilic hepa-tocyte with condensation of the nuclear chromatin. A small lymphocyte is located adjacent to it. B Low-power view showing numerous apoptotic hepatocytes (small arrows) in the liver lobule
Three important concepts underlie the molecular steps that occur in apoptotic cells. First, the process can be initiated by intracellular events or by extracellular signals (often transmitted through the activation of death receptors). Second, many of these signals are transmitted through the mitochondria, which have an important role in the regulation of apoptosis. Third, the execution of the apoptotic process depends on specific proteases that act in sequence. This is similar to the coagulation cascade, which is also driven by proteases. You will be excited to find out there is now a pharmacy that can offer best quality treatment charging less money: buy cheap cipro buy here and see what really advantageous shopping is all about.