The Fine Structure of Glycocalyx in Human Spermatozoa. A High Resolution Cytochemical Study

1973 ◽  
Vol 31 ◽  
pp. 640-641
Author(s):  
P. Hernández-Jáuregui ◽  
A. Sosa ◽  
A. González Angulo
Keyword(s):  
Negative Charge ◽  
Iron Hydroxide ◽  
Human Spermatozoa ◽  
Surface Coat ◽  
Cell Surfaces ◽  
Colloidal Iron ◽  
Cytochemical Study ◽  
Specific Permeability ◽  
Extracellular Glycoprotein ◽  
Mammalian Spermatozoa

Glycocalyx is the name given by Bennett to the extracellular glycoprotein coat present in some cell surfaces. It appears to play an important role in cell properties such as antigenicity, cell adhesivity, specific permeability, and ATP ase activity. In the sperm this coat can be directly related to such important phenomena as capacitation and fertilization. The presence of glycocalyx in invertebrate spermatozoa has already been demonstrated. Recently Yanagimachi et al. has determined the negative charges on sperm surfaces of mammalian spermatozoa including man, using colloidal iron hydroxide. No mention was made however of the outer surface coat as composed of substances other than those confering a negative charge. The purpose of this work was therefore to determine the presence of a glycocalyx in human spermatozoa using alcian blue and lanthanum staining.

scholarly journals Negative charge distribution and density on the surface of oxygenated normal and sickle red cells

Blood ◽  
1981 ◽  
Vol 57 (4) ◽  
pp. 675-678
Author(s):  
LJ Clark ◽  
LS Chan ◽  
DR Powars ◽  
RF Baker
Keyword(s):  
Charge Distribution ◽  
Electron Micrographs ◽  
Negative Charge ◽  
External Surface ◽  
Iron Hydroxide ◽  
Red Cells ◽  
Glutaraldehyde Fixation ◽  
Colloidal Iron ◽  
Membrane Area ◽  
Significant Difference

Negative charges on the external surface of red cells were visualized by colloidal iron hydroxide labelling of 50% of the membrane area after osmotic hemolysis and glutaraldehyde fixation. Counts were made over randomly selected areas on electron micrographs at 350,000 x magnification. Statistical analyses showed that at the 95% level of confidence there was no significant difference between oxygenated normal (AA) and sickle (SS) cells in either the distribution or the density of negative charges.

scholarly journals Negative charge distribution and density on the surface of oxygenated normal and sickle red cells

Blood ◽  
1981 ◽  
Vol 57 (4) ◽  
pp. 675-678 ◽  
Author(s):  
LJ Clark ◽  
LS Chan ◽  
DR Powars ◽  
RF Baker
Keyword(s):  
Charge Distribution ◽  
Electron Micrographs ◽  
Negative Charge ◽  
External Surface ◽  
Iron Hydroxide ◽  
Red Cells ◽  
Glutaraldehyde Fixation ◽  
Colloidal Iron ◽  
Membrane Area ◽  
Significant Difference

Abstract Negative charges on the external surface of red cells were visualized by colloidal iron hydroxide labelling of 50% of the membrane area after osmotic hemolysis and glutaraldehyde fixation. Counts were made over randomly selected areas on electron micrographs at 350,000 x magnification. Statistical analyses showed that at the 95% level of confidence there was no significant difference between oxygenated normal (AA) and sickle (SS) cells in either the distribution or the density of negative charges.

A High Resolution Cytochemical Study of Nuclear ATPase in Human Spermatozoa

1975 ◽  
Vol 33 ◽  
pp. 594-595
Author(s):  
A. Sosa ◽  
L. Calzada
Keyword(s):  
High Resolution ◽  
Atpase Activity ◽  
Nuclear Membrane ◽  
Human Sperm ◽  
Sperm Nucleus ◽  
Human Spermatozoa ◽  
Cytochemical Study ◽  
Membrane Bound ◽  
Sperm Nuclei ◽  
Interchromatin Space

The dependence of nuclear metabolism on the function of the nuclear membrane is not well understood. Whether or not the function of the nuclear membrane is partial or totally responsible of the repressed template activity of human sperm nucleus has not at present been elucidated. One of the membrane-bound enzymatic activities which is concerned with the mechanisms whereby substances are thought to cross cell membranes is adenosintriphosphatase (ATPase). This prompted its characterization and distribution by high resolution photogrammetry on isolated human sperm nuclei. Isolated human spermatozoa nuclei were obtained as previously described. ATPase activity was demonstrated by the method of Wachstein and Meisel modified by Marchesi and Palade. ATPase activity was identified as dense and irregularly distributed granules confined to the internal leaflet of the nuclear membrane. Within the nucleus the appearance of the reaction product occurs as homogenous and dense precipitates in the interchromatin space.

Effect of brefeldin A (BFA) on the unique surface coat of pulmonary intravascular macrophages (PIMs) of sheep: Ultrastructural and cytochemical study

1993 ◽  
Vol 51 ◽  
pp. 18-19
Author(s):  
Baljit Singh
Keyword(s):  
Brefeldin A ◽  
Ultrastructural Feature ◽  
Surface Coat ◽  
Anterograde Transport ◽  
Cytochemical Study ◽  
Active Involvement ◽  
Electron Lucent ◽  
Pulmonary Intravascular Macrophages ◽  
Unique Surface

The PIM of sheep, calf, goat and horse has a characteristic ultrastructural feature in the form of a unique, heparin sensitive, globular surface coat present around the plasma membrane with an intervening electron lucent space of 32-40 nm. We previously showed the active involvement of this surface coat in the phagocytosis of tracer material like monastral blue and cationized ferritin. The surface coat is capable of reconstitution in vivo following disruption with heparin. The present study was aimed to investigate whether PIM is the source of surface coat or not. In the recent years the BFA has been extensively used to understand the secretory pathways in the cells because of its ability to cause a rapid and reversible block to the anterograde transport of proteins from the endoplasmic reticulum to the Golgi.Sheep (n=6) were weighed, their plasma volume was calculated indirectly and based on which a sufficient single intravenous dose of BFA was given so as to reach a concentration of 4-5 microgram/ml of plasma.

Studies On Plasma Membranes

1967 ◽  
Vol 2 (4) ◽  
pp. 499-512
Author(s):  
E. L. BENEDETTI ◽  
P. EMMELOT
Keyword(s):  
Sialic Acid ◽  
Tight Junctions ◽  
Plasma Membranes ◽  
Iron Hydroxide ◽  
Chelating Agent ◽  
Colloidal Iron ◽  
Outer Leaflet ◽  
Liver Membranes ◽  
Junctional Complexes ◽  
Pre Treatment

Plasma membranes were isolated from rat liver and a transplanted rat hepatoma of the hepatocellular type. After glutaraldehyde fixation the membranes were treated with colloidal iron hydroxide (CIH) at pH 1.7, which was found to react specifically with the neuraminidase-sensitive sialic acid of the liver membranes. The CIH-reactive, neuraminidase-sensitive sialic acid, comprising 70% of the membrane-bound sialic acid, was exclusively located in the outer leaflet of the liver membranes as shown by the rather regular distribution of electron-dense CIH granules. This granular, asymmetric type of staining was also observed in the hepatoma membranes, which contained some 50% more sialic acid than did the liver membranes. In addition, the hepatoma membranes showed an intense and uniform staining by CIH of short segments of both membrane leaflets; the latter type of staining was but little impaired by neuraminidase pre-treatment. None of the junctional complexes of the liver membranes was stained by CIH. Tight junctions were very rarely observed in the hepatoma membrane preparations, and the desmosomes and intermediate junctions of these membranes not infrequently exhibited a loosened appearance exposing CIH-reactive neuraminidase-sensitive sialic acid at their opposite plates. This aspect could be induced in the desmosomes and intermediate junctions, but not in the tight junctions, by pre-treatment of the liver membranes with the chelating agent ethylenediaminetetra-acetate.

Expression of anionic sites on tumour cells at different stages of tissue invasion in vivo: a comparative study by X-ray microanalysis

1989 ◽  
Vol 94 (3) ◽  
pp. 561-566
Author(s):  
P.M. Evans ◽  
D.K. Suker ◽  
I. ap Gwynn
Keyword(s):  
Iron Hydroxide ◽  
Tumour Cells ◽  
Ehrlich Carcinoma ◽  
Similar Degree ◽  
Anionic Sites ◽  
Colloidal Iron ◽  
Cell Behaviour ◽  
X Ray ◽  
Invasion Stage

Quantification of colloidal iron hydroxide (CIH) labelling by X-ray microanalysis was used to investigate anionic sites at the surface of Ehrlich carcinoma cells from different locations in the mouse host. Individual tumour cells from peritoneal ascites suspensions (pre-invasion stage) varied up to threefold in their ability to bind CIH and a similar degree of intra-tumour heterogeneity was observed in different experimental animals. Pretreatment of the cells with neuraminidase confirmed that binding was at least partly due to surface sialic acid. Invasive cells isolated from mesenteric tumour nodules were also heterogeneous with regard to the availability of surface anionic sites, as were tumour cells adhering to the surface of the mesentery; however, in both these populations CIH binding was significantly greater on average than for free ascites tumour cells. The results suggest that surface anionic sites are determinants of the invasiveness of malignant cells in vivo, and that both the number and topography of these sites may be important in modulating tumour cell behaviour.

Visualization of Charged Groups on the Surface of Rat Liver Nuclei

1974 ◽  
Vol 16 (3) ◽  
pp. 665-675
Author(s):  
ISMO VIRTANEN ◽  
JORMA WARTIOVAARA
Keyword(s):  
Rat Liver ◽  
Plasma Membranes ◽  
Iron Hydroxide ◽  
Nuclear Surface ◽  
Colloidal Iron ◽  
Rat Liver Nuclei ◽  
Ph Values ◽  
Liver Nuclei ◽  
Pre Treatment ◽  
Anionic Groups

Anionic groups on the outer surfaces of isolated rat liver nuclei were rendered visible in the electron microscope by staining with colloidal iron hydroxide at different pH values. At pH 1.8 the nuclei did not adsorb particles of stain, although plasma membranes left in the same preparation showed heavy labelling. After pretreatment with neuraminidase at pH 6 the plasma membranes were no longer stained. At pH 3.0 the nuclear surfaces also stained intensely. The staining pattern acquired at this pH did not appear to be changed by neuraminidase pre-treatment. With the staining method used, rat liver nuclear surfaces seemed to have no exposed sialic acid under isolation conditions which preserve the nuclear membranes and leave the ribosomes attached to the nuclear surface. However, at higher pH values other anionic groups seem to become dissociated and are stained with colloidal iron hydroxide.

scholarly journals ANIONIC SITES OF HUMAN ERYTHROCYTE MEMBRANES

1973 ◽  
Vol 59 (2) ◽  
pp. 395-406 ◽  
Author(s):  
Garth L. Nicolson ◽  
Richard G. Painter
Keyword(s):  
Iron Hydroxide ◽  
Membrane Surface ◽  
Erythrocyte Membranes ◽  
Temperature Dependent ◽  
Colloidal Iron ◽  
Acetylneuraminic Acid ◽  
Peripheral Protein ◽  
Human Erythrocyte Membranes ◽  
Γ Globulins ◽  
Topographic Distribution

The effects of affinity-purified antispectrin γ-globulins on the topographic distribution of anionic residues on human erythrocytes membranes was investigated using collo ida iron hydroxide labeling of mounted, fixed, ghost membranes. Antispectrin γ-globulins were sequestered inside ghosts by hemolysis and the ghosts were incubated for 30 min at 37°C and then fixed with glutaraldehyde. The topographic distribution of colloidal iron hydroxide clusters on ghosts incubated with low (<0.05 mg/ml) or high (>5–10 mg/ml concentrations of sequestered antispectrin was dispersed, but the distribution at intermediate concentrations (0.1–5 mg/ml) was highly aggregated. The aggregation of colloidal iron hydroxide binding sites was time and temperature dependent and required the sequestering of cross-linking antibodies (antispectrin Fab could not substitute for γ-globulin antibodies) inside the ghosts. Prior glutaraldehyde fixation or fixation at the time of hemolysis in antispectrin solutions prevented the antispectrin-induced colloidal iron site aggregation. The antispectrin reacted exclusively at the inner ghost membrane surface and the colloidal iron hydroxide bound to N-acetylneuraminic acid residues on the outer membrane surface which are overwhelming on the sialoglycoprotein glycophorin. These results were interpreted as evidence for a structural transmembrane linkage between the inner surface peripheral protein spectrin and the integral membrane component glycophorin.

scholarly journals Iron removal by precipitate flotation

2014 ◽  
Vol 67 (2) ◽  
pp. 203-207 ◽  
Author(s):  
Denise Fontoura Morosini ◽  
Carlos Adolpho Magalhães Baltar ◽  
Antonio Carlos Duarte-Coelho
Keyword(s):  
Iron Hydroxide ◽  
Sodium Dodecyl ◽  
Industrial Processes ◽  
Colloidal Iron ◽  
Residual Concentration ◽  
High Iron Content ◽  
Original Solution ◽  
Ion Removal ◽  
Glass Column ◽  
Artesian Wells

The water from several artesian wells in the metropolitan area of Recife presents high iron content, preventing its use in some industrial processes. The possibility of removing the iron by the use of precipitate flotation using sodium dodecyl sulphate (SDS) as collector was studied. The tests were carried out in a glass column 65 cm high, fed by a constant airflow. At pH 8, where the isoelectric point of colloidal iron hydroxide [Fe(OH)3] was observed, the size of the precipitate increases with conditioning time and facilitates the removal of iron ions by flotation. The results showed that an increase in conditioning time, from 5 to 20 minutes, resulted in a reduction of the residual concentration of iron from 13.2 to 0.2 ppm. The decrease in precipitate specific surface area rendered a decrease in the collector consumption possible. The iron ion removal process by flotation using SDS as collector was shown to be quite efficient. A removal of 99% of Fe3+ contained in the original solution was obtained.

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