The microbial ecology of cow slurry in vermiculture beds

The suitability of cow slurry as a substrate for vermicomposting by Eisenia fetida was investigated. Particular attention was given to the effects of the earthworm on the decomposition and stabilisation of the slurry; and to the interactions between E. fetida and the microflora of the substrate. Assessment of the chemical and microbiological changes in cow slurry stored under forced aeration, and subsequently in shallow trays, showed that neither method was suitable for the treatment of slurry. A comparison of two methods of vermicomposting showed that top-feeding of slurry was more efficient in promoting earthworm growth and cocoon production than the mixing of slurry with solid materials. Management practices were found to have an important influence on the efficiency of the process. An investigation o:f the effect of E. fetida. on the decomposition of slurry indicated that the presence of this earthworm enhanced the stabilisation of the substrate and increased the plant-available nitrogen content. Specific nutritional interactions were observed between E. fetida and micro-organisms in sand/cellulose microcosms. The earthworms were found to be feeding directly upon the cells of certain micro-organisms. Other species were found to be toxic to E. fetida.. A technique was developed :for the production of axenic E. fetida., and the use of such earthworms in :feeding experiments confirmed the importance of some micro-organisms in earthworm nutrition. The seeding of vermiculture beds with one such micro-organism stimulated earthworm growth and consumption of the substrate. Vermicomposted mixtures of cow slurry and spent mushroom compost were shown to have potential application as casing materials in mushroom cultivation. The findings of this study indicate the suitability of vermicomposting as a method for the stabilisation of intensively-produced cow slurry, and give some indication of the importance of micro-organisms in the nutrition of E. fetida.

Inhibition of secretary activity in cells isolated from the rat stomach

The overall aim of this study was to further understanding of themechanisms by which inhibitors of secretory activity mediate their action inisolated stomach cells. One objective was to determine whether a G-proteinsensitive to inactivation by pertussis toxin was involved in the action of thefollowing inhibitors of histamine-stimulated acid secretion: prostaglandin E2(PGE2), somatostatin, epidermal growth factor (EGF) and 12-0-tetradecanoylphorbol 13-acetate (TPA), an activator of protein kinase C.The site and mechanism by which EGF inhibited acid secretion and itseffects on pepsinogen secretion were also of interest. Further objectiveswere to determine whether TPA could induce down-regulation of proteinkinase C in parietal cells and to examine the inhibitory action of cyclic GMPon acid secretion. Acid secretion was estimated by the accumulation of theweak base aminopyrine in parietal cells. Experiments in which cells were preincubated with pertussis toxinindicated that PGE2, somatostatin and EGF mediated their inhibitory actionagainst histamine-stimulation via an inhibitory G-protein of the "Gi·like"family. Stimulation of PGE2 production by EGF also involved a pertussistoxin-sensitive G-protein. EGF inhibited acid secretion stimulated byforskolin, but only in the absence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). This action of EGF was sensitive toinactivation by pertussis toxin. It is suggested that the effect of EGF was dueto an increase in low Km cyclic AMP phosphodiesterase activity, rather thanan effect on the histamine (H2) receptor. EGF did not inhibit pepsinogensecretion. TPA exerted only a small part of its inhibitory action by a mechanismsensitive to pertussis toxin. TPA was unable to induce detectable down-regulationof protein kinase C. Acid secretion stimulated by near-maximallyeffective concentrations of h1stamme plus IBMX, dibutyryl cyclic AMP(dbcAMP) and K+ was inhibited by dibutyryl cyclic GMP (dbcGMP).

A collagen IV matrix is required for guinea pig gastric epithelial cell monolayers to provide an optimal model of the stomach surface for biopharmaceutical screening

The surface epithelial cells of the stomach represent a major component of the gastric barrier. A cell culture model of the gastric epithelial cell surface would prove useful for biopharmaceutical screening of new chemical entities and dosage forms. Primary cultures of guinea pig gastric mucous epithelial cells were grown on filter inserts (Transwells®) for 3 days. Tight-junction formation, assessed by transepithelial electrical resistance (TEER) and permeability of mannitol and fluorescein, was enhanced when collagen IV rather than collagen I was used to coat the polycarbonate filter. TEER for cells grown on collagen IV was close to that obtained with intact guinea pig gastric epithelium in vitro. Differentiation was assessed by incorporation of [ 3H]glucosamine into glycoprotein and by activity of NADPH oxidase, which produces superoxide. Both of these measures were greater for cells grown on filters coated with collagen I than for cells grown on plastic culture plates, but no major difference was found between cells grown on collagens I and IV. The proportion of cells, which stained positively for mucin with periodic acid Schiff reagent, was greater than 95% for all culture conditions. Monolayers grown on membranes coated with collagen IV exhibited apically polarized secretion of mucin and superoxide, and were resistant to acidification of the apical medium to pH 3.0 for 30 min. A screen of nonsteroidal anti-inflammatory drugs revealed a novel effect of diclofenac and niflumic acid in reversibly reducing permeability by the paracellular route. In conclusion, the mucous cell preparation grown on collagen IV represents a good model of the gastric surface epithelium suitable for screening procedures. © 2005 The Society for Biomolecular Screening.

Footballers and social media ‘Faux Pas’:the Football Association’s cash cow?

Reflects on the increasing scope for irresponsible comments made on social media sites to attract civil or criminal penalties, and how such remarks by professional footballers have generated significant amounts of revenue for the Football Association (FA). Reviews the range of social media "faux pas" committed by footballers, the large fines imposed by the FA Regulatory Commission and why these constitute a useful "cash cow".