AIMS To evaluate the effect of Vibrio harveyi strains on the growth rate of the gnotobiotically cultured rotifer Brachionus plicatilis, and to establish whether quorum sensing is involved in the observed phenomena. METHODS AND RESULTS Gnotobiotic B. plicatilis sensu strictu, obtained by hatching glutaraldehyde-treated amictic eggs, were used as test organisms. Challenge tests were performed w...

The runoff of a mixture of "heavy" and "light" polysomes has been reported to yield hybrid ribosomes, of intermediate density. However, we found that the dissociation of free heavy ribosomes as they advance in a sucrose gradient causes a serious artefact in the demonstration of hybrid ribosomes. This artefact is eliminated by fixation with glutaraldehyde before sedimentation. Formation of hybri...

To probe internal motions in proteins on the 10(-8)-10(-5) s time scale by NMR relaxation, it is necessary to eliminate protein tumbling. Here, we examine to what extent magnetic relaxation dispersion (MRD) experiments on the water (1)H resonance report on protein motions in this time window. We also perform a critical test of two physically distinct mechanisms that have been proposed to explai...

Chitosan microspheres of a small particle size and with good sphericity were prepared by a spraydrying method followed by treatment with a cross-linking agent. Owing to restrictions on the use of crosslinked chitosan microspheres in the pharmaceutical field, d,l-glyceraldehyde, a biocompatible reatant was used. The parameters studied affecting extent of cross-linking were cross-linking time and...

We have investigated the relationship of concanavalin. A binding to the cell surface of normal and transformed cells and the subsequent agglutination of the transformed cells. At room temperature almost no differences could be detected in agglutinin binding between transformed and untransformed cells. At 0 degrees C, however, where endocytosis was negligible, the transformed cells bound three t...

There has been considerable discussions on why some types of haemoglobin-based blood substitutes increase vasoactivity whereas a very few others do not. In this study, we prepare four different types of PolyHb each containing different percentage of tetrameric hemoglobin using glutaraldehyde crosslinking and characterized to ensure that they all have the same oxygen affinity. Thus the preparati...

Natural benthic substrates were collected beneath the ice of Grand Traverse Bay by divers on March I0, 1978 as part of a seasonal investigation of northern Lake Michigan benthic algae assemblages. Some of the samples from each selected depth between the surface and 32 m were examined using SEM. Natural substrates (silt, sand, pebbles, algae, shells) were field-fixed in glutaraldehyde, dehydrate...

SEPALLATA (SEP) MADS-box genes play crucial roles in the regulation of floral growth and development. They are required for the specification of sepals, petals, stamens, and carpels as well as for floral determinacy. SEPs perform their functions through the formation of homo- or hetero-polymers, which are the molecular basis of floral quartets. In vitro assays indicated that SEP3 forms a tetram...

In employing fixed frozen ultrathin sections as substrates for immunoferritin labeling of intracellular antigens, we have found that conventional glutaraldehyde fixation sometimes permits very little specific staining of the sections, either because it inactivates certain protein antigens, or because it renders them inaccessible to the antibody stains. We have developed several fixation procedu...

Two forms' of glutaraldehyde were used in these studies, the first, a highly purified monomeric form, and the second, a condensed form : (a) TAAB2 glutaraldehyde was purified by shaking with charcoal and distillation (Fahimi and Drochmans, 1965) . As received, this material always has considerable spectrophotometric absorption at 235 nm, which was completely removed by this purification procedu...