Factors Influencing the Survival and Revival of Heat-treated Escherichia coli

Maximal revival of heat-damaged Escherichia coli occurred in nutrient media containing 0.8 to 1.0% (w/v) of Difco yeast extract. Vitamins did not appear to be involved in the recovery process. The situation with amino acids was less clear-cut, and, although certain of these may be essential for revival, proof for this is as yet inconclusive. Replica plating, in which colonies (from cells which had survived a heating process) on a rich medium were replicated onto minimal agar, revealed that no auxotrophic mutants had been formed as a result of heat treatment. Bacteria which were heated in 1% (w/v) yeast extract were killed more slowly than those heated in water.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

A comparative study on the effects of different bile salts on mucosal ATPase and transport in the rat jejunum in vivo.

The effects of deoxycholate, taurocholate and cholate on transport and mucosal ATPase activity have been investigated in the rat jejunum in vivo using closed-loop and perfusion techniques. In the closed-loops, 5 mM deoxycholate selectively inactivated (Na+ + K+)-ATPase, and net secretion of Na+ induced by 2.5 mM deoxycholate was due to reduced lumen to plasma flux of the ion; deoxycholate (2.5 mM) produced marked inhibition of 3-0-methylglucose transport. Luminal disappearance rates of deoxycholate (60.5 plus or minus 2.9% per g wet st of gut) greatly exceeded those of taurocholate (4.3 plus or minus 1.0). In the perfusion studies 1 mM deoxycholate induced net secretion of water, Na+ and C1-, and inhibited active glucose transport; concomitantly "total" ATPase, (Na+ + K+)-ATPase, and Mg-2+-ATPase were inhibited. At higher concentrations (5 mM) deoxycholate stimulated Mg-2+-ATPase activity. Taurocholate and cholate at 1mM had no effect on transport of (Na+ + K+)-ATPase. Mucosal lactase, sucrase and maltase activities were not affected by 1 mM deoxycholate, taurocholate or cholate. These results suggest that deoxycholate inhibits sodium-coupled glucose transport by inhibition of (Na+ + K+)-ATPase at the lateral and basal membranes of the epithelial cell, rather than from an effect at the brush-border membrane level.     

Towards a gene expression biomarker set for human biological age

We have previously described a statistical model capable of distinguishing young (age <65 years) from old (age ≥75 years) individuals. Here we studied the performance of a modified model in three populations and determined whether individuals predicted to be biologically younger than their chronological age had biochemical and functional measures consistent with a younger biological age. Those with ‘younger’ gene expression patterns demonstrated higher muscle strength and serum albumin, and lower interleukin‐6 and blood urea concentrations relative to ‘biologically older’ individuals (odds ratios 2.09, 1.64, 0.74, 0.74; P = 2.4 × 10^?2, 3.5 × 10^?4, 1.8 × 10^?2, 1.5 × 10^?2, respectively). We conclude that our expression signature of age is robust across three populations and may have utility for estimation of biological age.