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Integrity of the cell membrane is a basic requirement for maintaining the biological characteristics of a cell. In this study, cell membrane as the target of drug action was investigated. CCK-8 assay suggested that Artesunate (ART) could significantly suppress the proliferation of Jurkat cells in a dose-dependent manner. Changes in the morphology and mechanics of Jurkat cells were studied by atomic...
The complex crossed structures with a polymorph of calcite, termed a chalky layer, which make up much of the shell of an oyster, are composed of flames and leaflets. Two layers, folia and the chalky layer in the giant Pacific oyster (Crassostrea gigas) were examined using SEM (scanning electron microscope), micro-area-XRD (X-ray diffraction) and FT-IR (Fourier transform infrared spectrometer) to determine...
The pathological changes of erythrocytes were detected at the nanometer scale, which was important for revealing the onset of diseases, early diagnosis, and effective therapies. Diseases may disturb the morphology and function of erythrocytes at molecular scale. There were dramatic surface deformations in topography of erythrocytes from a patient with elliptocytosis complicating idiopathic thrombocytopenic...
The goals of this study were to monitor the nucleolar material distribution during Dendropsophus minutus spermatogenesis using cytological and cytochemical techniques and ultrastructural analysis, as well as to compare the nucleolar material distribution to the formation of the chromatoid body (CB) in the germ epithelium of this amphibian species. Nucleolar fragmentation occurred during the pachytene...
The germ cells in the germarium of the bee meroistic polytrophic ovarian cysts remain interconnected by cytoplasmic bridges as a result of incomplete cell division. These intercellular bridges form a distribution pathway for the substances that initially determine which of the cystocytes will become oocyte and later conduct the products synthesized by the nurse cells to the oocyte. In the present...
The morphology of polyester-based polyurethanes was observed by transmission electron microscopy, which highlighted a nanostructured system made by a continuous distribution of hard domains with size equal to few nanometres in the soft matrix.
The culture and physiology of red macroalgae calluses are well documented. To date, however, no report has either performed a cytochemical analysis or characterized the ultrastructural organization of calluses at different stages of development and under the effect of plant growth regulators. Therefore, to undertake such analyses, this work studied the red seaweed Gracilariopsis tenuifrons (Bird et...
This paper describes a methodology based on hollow-cone dark-field (HCDF) transmission electron microscopy (TEM) to study dislocation structures in both nano- and micro-crystalline grains. Although the conventional approach based on a two-beam condition has been commonly used to acquire weak-beam dark-field (WBDF) TEM images for dislocation structure characterization, it is very challenging to employ...
Lysyl oxidases (LOXs) are enzymes that permit the covalent crosslinking of the component chains of collagen and elastin. These enzymes are present inside the nuclei of certain mammalian cells. Previous studies have proposed LOX binding to histone H1 in vitro, and histone H1 is known to control global chromatin compaction and mitotic chromosome architecture. Therefore, in the present study, we analyzed...
Trichobilharzia regenti (Schistosomatidae, Digenea), a parasite of birds, exhibits a unique strategy among schistosomes, having affinity to the nervous system of vertebrate hosts. Migration of parasitic stages within hosts and/or swimming of non-parasitic larvae in water environment depend on the action of body wall muscles which were studied with confocal and electron microscopy. In all stages, body...
Microwave radiation and conductive heating were used to completely kill adult Tribolium castaneum (Coleoptera: Tenebrionidae) in wheat flour to protect the flour during storage without significantly effecting its quality. The microstructure of T. castaneum was analyzed to reveal the mechanisms leading to death under microwave and heat treatments. Microwave radiation and conductive heating had different...
The ultrastructural and cytochemical characterization of the brown soft scale, Coccus hesperidum L. (Hemiptera: Coccidae) infected by the hyphomycete Lecanicillium lecanii (Zimmermann) Gams & Zare, belonging to the phylum Ascomycota and order Hypocreales, was investigated by light, scanning and transmission electron microscopy. Gold cytochemistry was used to label chitin in the cuticle of the...
The scanning transmission electron microscope (STEM) and the atomic force microscope (AFM) have provided a wealth of useful information on a wide variety of biological structures. These instruments have in common that they raster-scan a probe over a sample and are able to address single molecules. In the STEM the probe is a focused electron beam that is deflected by the scan-coils. Detectors collecting...
Resolution in transmission electron microscopy (TEM) now is limited by the properties of specimens, rather than by those of instrumentation. The long-standing difficulties in obtaining truly high-resolution structure from biological macromolecules with TEM demand the development, testing, and application of new ideas and unconventional approaches. This review concisely describes some new concepts...
High-resolution scanning electron microscopy (HRSEM) is being used increasingly to gain new insights into three-dimensional organization of biological structure, macromolecular complexes and interactions of cellular components as well as isolated cell organelles. Modern scanning electron microscopes (SEMs) combined with adequate sample preparation can now provide resolution comparable with that achieved...
Nanogold and undecagold are covalently linked gold cluster labels which enable the identification and localization of biological components with molecular precision and resolution. They can be prepared with different reactivities, which means they can be conjugated to a wide variety of molecules, including nucleic acids, at specific, unique sites. The location of these sites can be synthetically programmed...
The technology to produce cryo-electron tomography on vitrified sections is now a few years old and some specialised labs worldwide have gathered sufficient experience so that it is justified at this point to critically analyse its usefulness for cellular and molecular biology, and make predictions on how the method might develop from here. Remarkably, the production of vitrified sections has been...
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