| Characterization of apoptosis mainly derives from morphological and ultrastructural observations (1). Intracellular and plasma membrane structural modifications have been widely recognized as crucial factors involved in cell injury and death. Changes in nuclear morphology and in organelle structure as well as specific phenomena at the cell surface level, namely surface smoothing and surface blebbing, are often considered as markers associated with cell pathology (2). In addition, it must be recalled that these structural findings are intimately related to the cascade of biochemical and physiological events leading to changes in cellular homeostasis, to the loss of cell volume regulation, to some modifications of macromolecule synthesis and, finally, to the loss of cell viability.A single intracellular event can be extensively analyzed by using, in parallel, biochemical, molecular or ultrastructural approaches. The complex sequence of structural modifications ultimately leading to cell death can be recognized by light and electron microscopy techniques. These analyses are mainly qualitative and can indicate: i) the different features of the apoptotic process in terms of appropriate markers, e.g. histotype-associated, and ii) the staging of the process, e.g. early or late phases (also called secondary necrosis). However, quantitative analyses, i.e. cytometric and morphometric, can also be performed by using light microscopy, fluorescence microscopy, confocal microscopy, scanning electron microscopy and, in some conditions, transmission electron microscopynumerous different techniques have been considered for studying apoptosis: i) light microscopy staining procedures, e.g. MayGrunwald-Giemsa, and ii) fluorescence microscopy techniques, e.g. DNA staining fluorochromes. Some of them are of great use in the laboratory practice while others are specifically employed in certain experimental conditions.the morphological features of apoptosis can be confused or overlap those typical of necrosis. For instance: the so-called secondary necrosis is difficult to be recognized and, in any case, necrosis should also be always evaluated; superaggregation of chromatin could often occur in situations other than apoptosis; lymphocytes very rarely undergo chromatin clumping although undergoing apoptosis; surface blebbing as well as surface smoothing are common markers of necrosis as well as of apoptosis, etc. Moreover, because apoptosis is an asyncronous process, all the apoptotic stages are usually detectable, earlier (light chromatin marginalization) and latest stages(residual bodies).At least three different apoptotic morphologies can be detected depending on: i) the stimulus; ii) the histotype; iii) the stage of apoptosis. For instance: i) four main pro-apoptotic stimuli can exist: a) those receptor-mediated (e.g. by cytokines, protein toxins etc), b) chemical agents, capable of entering the cells (e.g. toxicants, anticancer drugs, etc.), c) physical agents which do not interact "directly" with cells (e.g. by ionizing radiations); d) the lack of molecules of relevance in the cell life, (e.g. withdrawal of growth factors), ii) Different histotype, e.g. epithelial, neuronal etc, undergo apoptosis following specific pathways with precise features which also depend on their relationships with their environmental growth conditions, e.g. the type of interaction with other cells (e.g. desmosome mediated, gap junctions, synaptic connections etc) or with basement membranes, iii) being an asyncronous process, apoptotic process can be detected as a phenomenon with marked structural discrepancies which are associated with earlier or latest phases. All these conditions are intertwined together and share common features. These can provide useful information but also result in artifacts, errors and misleading results.Hippophae rhamnoides L. is a small genus of Elaeagnaceae in which 6 species and 10 subspecies have been recognized. These species are distributed widely but sparsely in Asia and Europe. Most of them, however, are restricted to Qinghai-Tibe...
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