Maggot secretions suppress pro-inflammatory responses of human monocytes through elevation of cyclic AMP.

AIMS/HYPOTHESIS: Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. As monocytes may contribute to the excessive inflammatory responses in such wounds, this study focussed on the effects of maggot secretions on the pro-inflammatory activities of these cells. METHODS: Freshly isolated monocytes were incubated with a range of secretions for 1 h and then stimulated with lipopolysaccharides (range 0-100 ng/ml) or lipoteichoic acid (range 0-5 microg/ml) for 18 h. The expression of cell surface molecules, cytokine and chemokine levels in culture supernatants, cell viability, chemotaxis, and phagocytosis and killing of Staphylococcus aureus were measured. RESULTS: Maggot secretions dose-dependently inhibited production of the pro-inflammatory cytokines TNF-alpha, IL-12p40 and macrophage migration inhibitory factor by lipopolysaccharides- and lipoteichoic acid-stimulated monocytes, while enhancing production of the anti-inflammatory cytokine IL-10. Expression of cell surface receptors involved in pathogen recognition remained unaffected by secretions. In addition, maggot secretions altered the chemokine profile of monocytes by downregulating macrophage inflammatory protein-1beta and upregulating monocyte chemoattractant protein-1 and IL-8. Nevertheless, chemotactic responses of monocytes were inhibited by secretions. Furthermore, maggot secretions did not affect phagocytosis and intracellular killing of S. aureus by human monocytes. Finally, secretions induced a transient rise in the intracellular cyclic AMP concentration in monocytes and Rp-cyclic AMPS inhibited the effects of secretions. CONCLUSIONS/INTERPRETATION: Maggot secretions inhibit the pro-inflammatory responses of human monocytes through a cyclic AMP-dependent mechanism. Regulation of the inflammatory processes by maggots contributes to their beneficial effects on chronic wounds.

Giving patients their own records in general practice: experience of patients and staff.

Patients have reacted positively to seeing their medical records in a general practice which has a predominantly working class population in south east London. Most patients were familiar with the information in their records. Older people tended to avoid reading their notes. There have been few inaccuracies and unpleasant reactions reported, and few problems have arisen.

KIE: Physicians in a general practice in a working class neighborhood in London decided to allow patients to read their medical records. A survey showed that most patients did take advantage of this policy, understood the notes, and found them helpful and interesting. Upsetting feelings were experienced by 11%. Of those who did not read the notes, only four (17%) were frightened by what they might read, while others stated that they did not have their glasses, could not read, did not think it was their place, thought the notes would not be interesting, or did not understand the policy. Problems concerning early signs of serious disease, third party desire not to reveal information, and encouragement of litigation are discussed. Sharing records is thought to encourage trust and to be reassuring when carried out with simple precautions.

The antimicrobial properties of magnesium monoperoxyphthalate hexahydrate.

The antimicrobial properties of magnesium monoperoxyphthalate hexahydrate (MMPP), which is a stable, water-soluble solid peroxyacid, have been investigated. A 2% (w/w) solution of MMPP rapidly kills yeasts and vegetative bacteria and slowly inactivates bacterial endospores at 22 degrees C. Biocidal activity, which is greater under mildly acidic conditions, is retained in the presence of organic contamination or hard water. Sporicidal action is greatly increased by a moderate rise in temperature or by using MMPP in combination with propan-2-ol. Such mixtures appear to be suitable for use as liquid chemical sterilants.

The bactericidal, fungicidal and sporicidal properties of hydrogen peroxide and peracetic acid.

The antimicrobial properties of aqueous solutions of peracetic acid and hydrogen peroxide have been compared. Peracetic acid exhibited excellent antimicrobial properties, especially under acidic conditions. Reductions by a factor of 10(6) in the numbers of vegetative bacteria are obtained within 1 min at 25 degrees C using a solution containing 1.3 mmol/l of peracetic acid. Rapid activity against bacterial spores and yeasts also occurs. Hydrogen peroxide is more effective as a sporicide than as a bactericide, with sporicidal action being obtained using a solution containing 0.88 mol/l. Bactericidal action is poor but hydrogen peroxide was bacteriostatic at concentrations above 0.15 mmol/l.

Copper accumulation by bacteria, moulds and yeasts.

The accumulation of copper by 137 strains of bacteria, 47 moulds and 14 yeasts, isolated from contaminated environments or obtained from culture collections, has been investigated with a view to obtaining a strain suitable for removing dissolved copper from effluents. The criteria sought were a relatively high uptake of copper together with an ability to grow without a lag and without any marked increase in the doubling time when exposed to moderately high concentrations of the metal. Organisms isolated from sites known to be contaminated with copper has low uptakes, the best strain, subsequently identified as a strain of Escherichia coli, being obtained from a site contaminated with cadmium, chromium and zinc.