The glycocalyx of the epithelial cells of the colon, observed in normal and ulcerous colitic conditions.

Biopsies of subjects affected by ulcerous colitis were stained with ruthenium Red. Alterations of the cellular coat and glycocalyx of the epithelial cells of the colon were identified.     

Assembly and genetics of spore protective structures

The sporulation program in Bacillus subtilis ends in the formation of a highly resistant endospore that can withstand extremes of heat, mechanical disruption, ultraviolet irradiation, lytic enzymes and chemical attack. These properties are attributed mainly to the unique structure of spore coat and cortex, as well as to the physical state of the spore cytoplasm. The outermost layer of the spore, called the coat, has two morphologically distinct sublayers: an electron-dense outer coat and an electron-translucent inner coat. The coat is composed of more than 2 dozen proteins of varying size. Many coat genes and coat proteins have been isolated and characterized in detail, and studies of these have identified proteins with important roles in coat assembly, resistance and spore germination. We describe here characteristics of the coat proteins and propose a model for coat assembly based on recent work.     

Degeneration of adrenergic axons in the longitudinal muscle coat of the rat duodenum following treatment with 6-hydroxydopamine.

Following systemic treatment with 6-OHDA, electron microscopy of adult rat duodenum showed degenerating adrenergic axons in the longitudinal muscle coat making neuromuscular relationships with gaps of varied widths.     

Seed coat thickness in the evolution of angiosperms

The seed habit represents a remarkable evolutionary advance in plant sexual reproduction. Since the Paleozoic, seeds carry a seed coat that protects, nourishes and facilitates the dispersal of the fertilization product(s). The seed coat architecture evolved to adapt to different environments and reproductive strategies in part by modifying its thickness. Here, we review the great natural diversity observed in seed coat thickness among angiosperms and its molecular regulation in Arabidopsis.     

Membrane traffic in the secretory pathway

Vesicular transport is the basic communication mechanism between different compartments in a cell and with the environment. In this review I discuss the principles of vesicle generation and consumption with particular emphasis on the different types of coat proteins and the timing of the shedding of the coat proteins from transport containers. In recent years it has become clear that there are more coat complexes than the classical COPI, COPII and clathrin coats. These additional coats may generate vesicles that transport cargo in a temporally and/or spatially controlled manner. Work over the last years suggests that GTP hydrolysis occurs early during vesicle biogenesis, destabilizing the coat perhaps before fission of the vesicle from the donor membrane occurs. Recent findings imply, however, that tethers at the receiving compartment specifically detect the coat on vesicle. (Part of a Multi-author Review)     

Membrane traffic in the secretory pathway

Vesicular transport is the basic communication mechanism between different compartments in a cell and with the environment. In this review I discuss the principles of vesicle generation and consumption with particular emphasis on the different types of coat proteins and the timing of the shedding of the coat proteins from transport containers. In recent years it has become clear that there are more coat complexes than the classical COPI, COPII and clathrin coats. These additional coats may generate vesicles that transport cargo in a temporally and/or spatially controlled manner. Work over the last years suggests that GTP hydrolysis occurs early during vesicle biogenesis, destabilizing the coat perhaps before fission of the vesicle from the donor membrane occurs. Recent findings imply, however, that tethers at the receiving compartment specifically detect the coat on vesicle. (Part of a Multi-author Review)     

Preparative separation of nucleated cells from human bone marrow.

A comparison has been made between the separation of nucleated cells from human bone marrow aspirates by high mol. wt polymers and the buffy coat techniques.     

Molecular machinery mediating vesicle budding,docking and fusion

A general machinery buds and fuses transport vesicles which connect intracellular compartments with each other and allow communication with the extracellular environment. Cytoplasmic coat proteins deform membranes to bud vesicles and interact directly or indirectly with cargo molecules. Compartment-specific SNAREs (SNAP receptors) on vesicles and target membranes dock vesicles and provide a scaffolding for the general fusion machinery to initiate lipid bilayer fusion.     

Binding of ferritin-lectin conjugates to C-type virus in intact cells.

Ferritin-Ricin II and Ferritin-Concanavalin A bound to budding as well as mature C-type viral particles. No differencies in binding between the viral coat and adjacent plasma membrane were detected with either lectin conjugate. Aggregation of viral particles by lectin conjugates was observed, and linking of virus to the plasma membrane resulted in phagocytosis of viral particles.     

Influence of the enteric surface coat on the unidirectional flux of acetamide across the wall of rat small intestine

In vivo treatment of the jejunal mucosa with glycosidic enzymes seems to remove the enteric surface coat of the enterocyte. As a consequence, the mucosa-to-serosa unidirectional flux of acetamide increases remarkably. The glycocalyx probably represents a barrier to the diffusion of small hydrosoluble solutes.     

Localization of vitelline-coat lysin purified from testis of a top shell,Turbo cornutus

Summary The vitelline-coat lysin purified from the testis ofTurbo cornutus was found, by an immunofluorescence technique, to be located in the acrosome of the sperm, which suggested that the lysin reacts with the vitelline-coat in an early phase of fertilization to allow the sperm to penetrate through the coat.We are grateful to Professor M. Akino (Tokyo Metropolitan University) for his helpful advice.     

Modification by calcium dobesilate of histamine effects on capillary ultrastructure.

The ultrastructure of blood capillaries and venules are studied in rat skin. After i.v. injection of histamine the luminal surface of the endothelial cells show protrusions of variable size. Numerous gaps have been found in the capillary wall, specially in the venules. These alterations are not observed in the animals that were treated with calcium dobesilate before the administration of histamine. In these cases the capillary structure are indistinguishable of the controls. The possible effects of the histamine and calcium dobesilate on the cell coat and cell junctions of the endothelial capillary cells are discussed.     

Alteration of cell shape in the early chick embryo mesoderm by neuraminidase

Summary Living chick embryo mesoderm cells (stages 3 to 5) were exposed to neuraminidase. The mesoderm cells changed shape losing their long thin processes and become like primitive streak cells, with short flat processes. Ruthenium red staining of such treated embryos shows that the surface coat on the mesoderm cells is reduced in thickness. These results show that cell shape in the chick embryo mesoderm is at least partly determined by the thickness and the composition of the surface coat.Acknowledgment. It is a pleasure to thank Professor F. Beck for the facilities of the Department of Anatomy, University of Leicester, and Mr. G. L. C. McTurk of the University of Leicester Scanning Electron Microscope Unit for operating the ISI 60 SEM. Mr Jeff Smith and Mrs Doris Duncan gave us valuable technical assistance and Dr. A. J. Rowe kindly allowed us to use the facilities of the Electron Microscope Unit, University of Leicester School of Biological Sciences, in specimen preparation.     

Fine structure of sensilla during moulting inNeomysis integer (Leach) (Crustacea,Mysidacea)

Summary During the moulting cycle the sensory cells and the newly formed hair shaft remain connected to the old cuticular receptive apparatus of the sensillum by the elongated outer segments of the dendrites, which run through the exuvial space. A surface coat covering the outer dendritic segments protects them against the chemical influences of the exuvial fluid. The findings suggest that the receptors remain functional until ecdysis. This moulting type is considered to be a transitional form between the moulting types so far known.     

Coating of centrospheres by reticulum cisternae and formation of spindle residues in segmentation mitosis under the action of an antitubulin substance: nocodazole]

When cleaving eggs are treated by nocodazole the reticulum cisternae coat the centrospheres instead of the chromosomes, as normally occurs at the late anaphase. At the same time the spindle is reduced to a common mass or spindle remnant, constituted of unorientated and fragmented microtubules which embed the kinetochores, i. e. the star configuration of the chromosomes. This action is quite similar to that of chloralhydrate but is different from that of colchicine.     

The cellular functions of clathrin

Membranes and proteins are moved around the cell in small vesicles. A protein coat aids the budding of such vesicles from donor membranes. The major type of coat used by the cell is composed of clathrin, a three-legged protein that can form lattice-like coats on membranes destined for trafficking. In this review, I outline what we know about clathrin and discuss some recent advances in understanding the basic biology of this fascinating molecule, which include building a molecular model of a clathrin lattice and discovery of a new function for clathrin that occurs during mitosis. Received 12 December 2005; received after revision 21 March 2006; accepted 29 March 2006     

Flavonoid profiles of certain species ofRhynchosia of the family Leguminosae (Fabaceae)

Summary A survey of seventy naturally occurring populations ofRhynchosia representing seven species of different subgenera revealed the occurrence of C-glycosides, O-glycosides, prenylated flavonoids and aglycones.Rhynchosia albiflora (R. cyanosperma) differs in gross morphological features and seed coat color and in its flavonoid composition from the other representative species ofRhynchosia.Acknowledgments. P. Ramachandraiah is grateful to U.G.C., New Delhi, for financial assistance.     

Preparative separation of nucleated cells from human bone marrow

Summary A comparison has been made between the separation of nucleated cells from human bone marrow aspirates by high mol.wt polymers and the buffy coat techniques.Acknowledgment. This investigation was supported by grant DHEW 5R01 CA 19997-02, awarded by the National Cancer Institute.     

Ultrastructural and quantitative analysis of the lipid droplet clustering induced by hepatitis C virus core protein

Hepatitis C virus (HCV) release is linked to the formation of lipid droplet (LD) clusters in the perinuclear area of infected cells, induced by the core protein. We used electron microscopy (EM) to monitor and compare the number and size of LD in cells producing the mature and immature forms of the HCV core protein, and 3D EM to reconstruct whole cells producing the mature core protein. Only the mature protein coated the LD and induced their clustering and emergence from endoplasmic reticulum membranes enriched in this protein. We found no particular association between LD clusters and the centrosome in reconstructed cells. The LD clustering induced by the mature core protein was associated with an increase in LD synthesis potentially due, at least in part, to the ability of this protein to coat the LD. These observations provide useful information for further studies of the mechanisms involved in HCV-induced steatosis.     

Copper metabolism in the LEC rat: Involvement of induction of metallothionein and disposition of zinc and iron

The Cu concentration was about 40 times higher in the liver of LEC (Long-Evans with a cinnamon-like coat color) rats aged 77 days (227.5±21.6 g/g liver) than in Fischer rats (5.2±0.1 g/g liver). However, in the kidney and brain of the LEC rats, Cu concentrations were lower than in these organs of the Fischer rats. Cu concentration in the hepatic metallothionein fraction was about 130 times higher in the LEC rats than in the Fischer rats. The LEC rats showed markedly low concentrations of Cu in the serum and bile. It seems likely that excretion of Cu from the liver into the bile and blood (as ceruloplasmin) is inherently lacking in the LEC rat.