Lack of correlation of in vitro adherence of Haemophilus influnzae to epithelial cells with frequent occurrence of otitis media

1987 ◽  
Vol 6 (1) ◽  
pp. 41-45 ◽  
Author(s):  
OSCAR PORRAS ◽  
HUGH C. DILLON ◽  
BARRY M. GRAY ◽  
CATHARINA SVANBORG-EDÉN
Keyword(s):  
Epithelial Cells ◽  
Otitis Media ◽  
Frequent Occurrence

Attachment of Streptococcus Pneumoniae to Human Pharyngeal Epithelial Cells in Vitro

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 115-116 ◽  
Author(s):  
B. Andersson ◽  
C-M. Peterson ◽  
O. Nylén ◽  
C. Svanborg-Edén
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epithelial Cells ◽  
Otitis Media ◽  
Virulence Factor ◽  
Healthy Person ◽  
Test System ◽  
Pharyngeal Mucosa ◽  
Adhesive Capacity ◽  
Media Group

The aim of this study has been to develop a test system for attachment of pneumococci to pharyngeal cells. Cells scraped from a healthy person were washed and quantitated, bacteria added and after incubation the suspension was washed and the number of adhering bacteria counted. Among strains from different infectious foci the highest number of strains with adhesive capacity was found in the otitis media group. Capacity to attach to the pharyngeal mucosa might be a virulence factor of pneumococci causing otitis media. There was a lack of distinct relation between capsular serotype and adhesive capacity indicating that the polysaccharide is not primarily responsible for the binding to epithelial cells. If attachment to the pharyngeal mucosa is a first step necessary for colonization and subsequent invasion of the tissues, then antibiotics in the secretions preventing such colonization might be of protective value in otitis-prone children.

Attachment of Streptococcus Pneumoniae to Human Pharyngeal Epithelial Cells in Vitro—Mechanism of Binding

1984 ◽  
Vol 92 (3) ◽  
pp. 266-269 ◽  
Author(s):  
B Andersson ◽  
A Fogh ◽  
F. JØRgensen ◽  
S Larsson ◽  
H Leffler ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Otitis Media ◽  
Binding Capacity ◽  
Cell Receptor ◽  
Surface Proteins ◽  
Bacterial Surface

To colonize mucosal surfaces and to invade underlying tissues, bacteria need to bind to components of the mucosa. Unattached bacteria are transported away from the surface with the fluid flow. By binding to the nasopharyngeal mucosa, Streptococcus pneumoniae causing otitis media may persist at the site of infection. High binding capacity of the bacterium and increased receptivity of the epithelial cells for attaching bacteria may both contribute to the susceptibility of patients prone to otitis. Thus, epithelial cells from children with frequent episodes of otitis bind attaching bacteria more readily than do cells from age-matched controls. The binding mechanism probably involves bacterial surface proteins and epithelial cell surface glycoconjugate receptors. Evidence is presented that phosphorylcholine, a component of the bacterial surface, as well as epithelial cell receptor analogues, that is, natural or synthetic saccharides analogous to the lactoneoseries of glycolipids, inhibits pneumococcal attachment. Inhibition of bacterial binding in vivo may be a new approach to prophylaxis against otitis media.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitro

2000 ◽  
Vol 111 (1) ◽  
pp. 363-370 ◽  
Author(s):  
Katsuto Takenaka ◽  
Mine Harada ◽  
Tomoaki Fujisaki ◽  
Koji Nagafuji ◽  
Shinichi Mizuno ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Progenitor Cells ◽  
Thymic Epithelial Cells ◽  
Erythroid Progenitor ◽  
Term Survival ◽  
Long Term Survival ◽  
Erythroid Progenitor Cells

Platelet Microtubule Subunit Proteins

1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford
Keyword(s):  
Epithelial Cells ◽  
Gel Electrophoresis ◽  
Blood Platelets ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Lens Epithelial Cells ◽  
Molecular Weights ◽  
Kinetics Of ◽  
Microtubular Structures

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.

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