PubMed Health⌕ Search

PubMed · 5260943

An L-glutamine requirement for intercellular adhesion.

Abstract

Intercellular adhesion presumably involves components of the cell surface, but the chemical nature of these substances is not known. The present studies suggest that complex carbohydrates are required for the adhesion of at least one type of animal cell. Single cells obtained from "embryoid bodies," the ascites-grown form of a mouse teratoma, aggregated in a complex tissue culture medium, but not in a glucose balanced salts solution. The active component of the tissue culture medium was identified as L-glutamine, and the only compounds found to replace it were the hexosamines D-glucosamine and D-mannosamine. A variety of studies indicated that the three compounds were active as a consequence of metabolic reactions. These results are consistent with known metabolic pathways and indicate that the conversion of nonadhesive to adhesive teratoma cells requires the synthesis of glycoproteins, glycolipids, and/or polysaccharides.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S B Oppenheimer, M Edidin, C W Orr, S Roseman. 1969. An L-glutamine requirement for intercellular adhesion.. https://doi.org/10.1073/pnas.63.4.1395

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Effect of capillary condensation on friction force and adhesion.

Friction force measurements have been conducted with a colloid probe on mica and silica (both hydrophilic and hydrophobized) after long (24 h) exposure to high-humidity air. Adhesion and friction measurements have also been performed on cellulose substrates. The long exposure to high humidity led to a large hysteresis between loading and unloading in the friction measurements with separation occurring at large negative applied loads. The large hysteresis in the friction-load relationship is attributed to a contact area hysteresis of the capillary condensate which built up during loading and did not evaporate during the unloading regime. The magnitude of the friction force varied dramatically between substrates and was lowest on the mica substrate and highest on the hydrophilic silica substrate, with the hydrophobized silica and cellulose being intermediate. The adhesion due to capillary forces on cellulose was small compared to that on the other substrates, due to the greater roughness of these surfaces.

Adhesiveness↗

Evaluation of bond strength of soft relining materials to denture base polymers.

OBJECTIVES: To evaluate the initial bonding properties of recently and previously introduced soft relining materials to denture base polymers with different polymerization techniques and different water content. METHODS: The initial tensile bond strength of 10 soft liners (Mollosil Plus, Dentusil, Ufi gel Soft, GC Reline Soft, Silagum Comfort, Vertex Soft, Astron Soft, Molloplast B, Flexacryl Soft, Triad Resiline) to three denture base polymers (Paladon 65, Palapress Vario, Ivocap Plus) were assessed with a modified method. Paladon 65 specimens immersed in water for 3 months were also used to test the effect of water content of denture base polymer on bond strength results. After testing, a visual examination of the fracture surfaces and a SEM investigation of the interface structure were performed. Tensile strength of each soft liner material was also tested. Data were analyzed statistically by two-way ANOVA (alpha = 0.05). RESULTS: Significant differences were found among tensile bond strength results (P < 0.05). Vinyl poly(organosiloxane) soft liners (Mollosil Plus, Dentusil, Ufi gel Soft, GC Reline Soft, Silagum Comfort) and a plasticized PMMA soft liner (Vertex Soft) gave statistically similar bond strength results for different denture base polymers (P>0.05). For the other materials used (Astron Soft, Molloplast B, Flexacryl Soft, Triad Resiline), different denture base polymers caused significantly different results (P < 0.05). Poly(organosiloxane) based materials gave slightly higher bond strength results with water immersed specimens than with the dry specimens. SIGNIFICANCE: A wide variety of newly formulated soft liners used in this study gave comparable or better bond strength results compared to Molloplast B.

Adhesiveness↗

Flat and sigmoidally curved contact zones in vesicle-vesicle adhesion.

Using the membrane-bending elasticity theory and a simple effective model of adhesion, we study the morphology of lipid vesicle doublets. In the weak adhesion regime, we find flat-contact axisymmetric doublets, whereas at large adhesion strengths, the vesicle aggregates are nonaxisymmetric and characterized by a sigmoidally curved, S-shaped contact zone with a single invagination and a complementary evagination on each vesicle. The sigmoid-contact doublets agree very well with the experimentally observed shapes of erythrocyte aggregates. Our results show that in identical vesicles with large to moderate surface-to-volume ratio, the sigmoid-contact shape is the only bound morphology. We also discuss the role of sigmoid contacts in the formation of multicellular aggregates such as erythrocyte rouleaux.

Adhesiveness↗