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At least 685 records · Page 38Linked to original sources
PubMed1988

Microbial inhibition on hospital garments treated with Dow Corning 5700 antimicrobial agent.

We evaluated the efficacy of the antimicrobial activity of cotton-polyester fabric treated with 3-(trimethoxysilyl)propyldimethyloctadecyl ammonium chloride (DC 5700), a quaternary ammonium compound bound irreversibly to the material. Significant antimicrobial activity was observed with 58 of 61 gram-positive cocci but with only 1 of 35 gram-negative bacilli and 0 of 5 yeasts. No inhibition of bacilli or yeasts was observed when the DC 5700 concentration ranged from 0.05 to 1.0% or when antimicrobial activity was assayed by the agar overlay bioassay or broth agitation methods.

Anti-Bacterial Agents↗
PubMed2001

[Appraisal of fungistatic and fungicidal activities of quaternary compounds towards yeasts belonging to the genera Candida and Cryptococcus].

The fungistatic and fungicidal activities of five quaternary ammonium compounds towards Candida and Cryptococcus strains were determined using a bacteriological method adapted to mycological experiments. It could be deduced from this study that Cryptococcus in spite of the capsule around the cell were more sensitive than Candida and that the benzethonium chloride (BC) exhibited the most effective action against the whole yeasts. No resistance appeared, only Cryptococcus strain was less sensitive than the others.

Anti-Infective Agents, Local↗
PubMed1984

Comparison of low- and high-pressure affinity chromatography for the purification of serine and sulfhydryl esterases.

A series of affinity chromatography packings for the purification of serine and sulfhydryl esterases (acetylcholinesterase, alkaline phosphatase, urokinase and papain) have been synthesized using commercially available agarose, glass and acrylate parent matrices. Two ligands were coupled to the matrices by utilizing carbodiimide or reaction with active groups already present on the matrix: the quaternary ammonium compound trimethyl(p-aminophenyl)ammonium chloride and the serine esterase inhibitor analog p-aminobenzamidine. It was found that enzyme purification on the agarose- or acrylate-based packings was most successful, resulting in as much as fifty-fold purification over starting material. The pressure stability of the acrylate packing allowed purification by high-pressure affinity chromatography and decreased purification times as much as six-fold in comparison to agarose columns.

Acetylcholinesterase↗
PubMed2005

Stabilization of nucleic acids by unusual polyamines produced by an extreme thermophile, Thermus thermophilus.

Extreme thermophiles produce two types of unusual polyamine: long linear polyamines such as caldopentamine and caldohexamine, and branched polyamines such as quaternary ammonium compounds [e.g. tetrakis(3-aminopropyl)ammonium]. To clarify the physiological roles of long linear and branched polyamines in thermophiles, we synthesized them chemically and tested their effects on the stability of ds (double-stranded) and ss (single-stranded) DNAs and tRNA in response to thermal denaturation, as measured by differential scanning calorimetry. Linear polyamines stabilized dsDNA in proportion to the number of amino nitrogen atoms within their molecular structure. We used the empirical results to derive formulae that estimate the melting temperature of dsDNA in the presence of polyamines of a particular molecular composition. ssDNA and tRNA were stabilized more effectively by tetrakis(3-aminopropyl)ammonium than any of the other polyamines tested. We propose that long linear polyamines are effective to stabilize DNA, and tetrakis(3-aminopropyl)ammonium plays important roles in stabilizing RNAs in thermophile cells.

DNA, Bacterial↗
PubMed1995

Rhythmic electrical and mechanical activity in stomach of toad and frog.

Rhythmic slow spikes and contractions at 2-5/min occur in frog/toad stomach when longitudinal muscle is present, not in the circular layer after removal of the longitudinal layer. Interstitial cells of Cajal occur in frog stomach in the longitudinal layer and in toad stomach mainly in the longitudinal layer, with some between layers. They were identified by staining with methylene blue, the fluorescent dye rhodamine 123, toluidine blue, and by electron microscopy. Interstitial cells resemble in ultrastructure those observed in mammalian intestine by small cell diameter, long processes forming a network, large nuclei, mitochondria, caveolae, endoplasmic reticulum, and absence of fibrillae. Rhythmic activity in stomachs stained with methylene blue is abolished by bright illumination. Rhythmic slow spikes and contractions are reduced and frequency is lowered when Ca2+ concentration in the medium is significantly decreased; in high Ca2+ these functions are increased. Threshold concentration of Ca2+ for maintaining slow spikes was between 10(-7) and 10(-6) M Ca2+. Ba2+ and 2.5 mM increases slow spike frequency and amplitude; Ba2+ increases contractions proportionately more than spikes. Slow spikes are reduced or blocked by verapamil, nifedipine, and Cd2+ and are enhanced by BAY K 8644. Quaternary ammonium compounds tetraethylammonium and tetrapentyl-ammonium bromide prolong slow spikes and enhance contractions. Replacement of NaCl by LiCl, methyl glutamine, or treatment with amiloride reduces slow spike amplitude and to a lesser extent frequency. This indicates efflux of Ca2+ by Na+/Ca2+ exchange. Contractions, but not spikes, are reduced by the calmodulin blocker trifluoroperazine. Contractions are enhanced, but slow spikes are not altered by ouabain. This suggests retention of Ca2+ when a tonic Na+/K+ pump is blocked. A model for rhythmicity includes influx of Ca2+ via L-channels, repolarization by IKCa2+, efflux of Ca2+ by Na+/Ca2+ exchange, and efflux of Na+ by a Na+/K+ pump. Frequency is determined by rate constants for both influx and efflux of Ca2+.

Animals↗