We examined atomic force microscopy (AFM) and lateral force microscopy (LFM) images of human, avian, reptilian, amphibian, and piscine erythrocytes to determine whether the general pattern of erythrocyte membrane architecture has been largely conserved in the course of phylogenetic evolution or relatively minor modifications have taken place. The general pattern of the cell surface structure is indeed very similar among the phyla examined. The surface features include a number of blebs or globular structures and hole-like depressions. Such features are particularly clear in fish (Heteropneustes sp.), in which globular blebs are arranged in tiers around the depressions. The same pattern is found in the other phyla, although the sizes of the blebs and depressions vary. The depressions are ϳ340 and ϳ100 nm in diameter in chickens and fish, respectively, and are smaller in other phyla. The images of human erythrocytes presented here show holes more clearly than the images obtained by Zhang et al. (Scanning Electron Microsc., 1995; 9:981-989), who showed for the first time the highly uneven surface of these cells. The globules range in size from ϳ50 -150 nm in diameter. These nanostructures have a width of approximately 333-1,000 atoms, assuming that the average dimension of an atom is 1.5 Å. The size range of the holes is approximately 40 -432 nm (equivalent to a width of approximately 266 -2880 atoms). LFM images, which take into account the lateral component of the force, represent the variation of surface friction (roughness) on the erythrocyte surface. This is very clear in the toad images, which show well-ordered strata that have not been revealed in ordinary AFM images.

Studies carried out on the properties of isolated ribosomes from drug-treated brain cortex slices indicate that ribosomes from drug-treated tissues are generally more susceptible to breakdown into smaller components such as proteins, nucleic acids, acid-soluble nucleotides, etc. It seems that some factor or factors responsible for the stability of the complex macromolecular structure of ribonucleoproteins of brain tissue are affected as a result of drug treatment. Ribosomal RNA from drug-treated brain tissue has been isolated under standardized conditions and the secondary structures of RNA have been studied by methods involving thermal hyperchromicity and reaction with formaldehyde. This latter study indicates that, during the action of some of these neuropharmacological drugs, the secondary structure of ribosomal RNA of brain tissue is partially lost. The loss in the stability of cytoplasmic ribonucleoproteins in drug-treated brain tissue may partly be due to the disorganization at the level of the secondary structure of the RNA component.

Atomic Force Microscope (AFM) is a relatively recent technique in the hands of material scientists and biologists[1] . Zhang et al. first imaged red blood cells by Atomic Force Microscope[2]. They reported that the membrane of red blood cells is highly uneven, consisting of elevations and depressions. Ohta et al. also published images of red blood cells showing random elevations and depressions[3]. Guha et al. reported 'Holes' or pits on the surface of human red blood cells by Atomic Force Microscopy[4]. Furthermore, Guha et al. revealed that the basic mode of red cell membrane ultrastructure is a series of globules (~50-150 nm) around depressions and holes(~ 40-430 nm) and this is evolutionarily conserved[5]. This pattern is particularly clear in case of fish[5].A blood film was drawn on glass slide and air dried. Red blood cells were imaged using Digital Instruments Nanoscope E, AFM, without any more preparation. Our investigation reveals that there are deep depressions and high elevations in these cells also. Of the 3 images of different thalassemic red cell we obtained, one is unusually good ( fig.1). Here, the size of the hole is much larger (~250 nm in dia.) and it looks like a well or hole drilled carefully. In this case the area around the hole is perfectly flat and so the hole is all the more clear-cut. Also it is much larger than in the normal human red blood cell (~40 nm). It is unlikely that these round holes or depressions are created due to a stress and shear during air drying.Biological significance of these round pits (holes) in normal and thalassemic red cells is still unknown and further work along these lines may shed light on the membrane structure and function.

Abstract— The ribosome preparation of goat cerebral cortex was found to possess acid and alkaline phosphodiesterase (PDase) activities, the alkaline PDase activity was greater. The alkaline PDase activity increased sharply between pH 8 and 9 and showed maximum activity between 35° and 40°. The alkaline PDase lost about half of its activity on heating the ribosome preparation at 83° for 5 min. Storage at low temperature or freezing and thawing did not cause significant loss of enzymic activity, but prolonged dialysis beyond 24 hr in the cold against magnesium‐cacodylate buffer caused some loss of activity. Copper, cobalt, inorganic phosphate ions, EDTA, urea and detergents were found to be inhibitors of the PDase activity. Differential inactivation in the presence of arsenate and zinc ions suggests the distinctness of the PDase activity from the phosphomonoesterase (PMase) activity of the ribosome preparation. The enzyme appeared firmly bound to ribosomal particles and attempts to solubilize it were unsuccessful.

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