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Using five species of bacteria as the test organisms, 151 species of British marine algae have been screened for the production of antibiotics. Of these, Asparagopsis armata, Bonnemaisonia asparagoides, Bonnemaisonia hamifera, Chondrus crispus, Dilsea carnosa, Gloiosiphonia capillaris, Sphondylothamnion multifidum, Desmarestia aculeata, Desmarestia ligulata, Laminaria digitata, Dictyopteris membranacea, Dictyota dichotoma, Halidrys siliquosa and most members of the family Rhodomelaceae appear to possess outstanding antibacterial properties. Although the production of antibiotics would appear to be a characteristic of several families, it has not been possible to establish any major correlation between taxonomy and antibiotic production. In the case of two closely related and morphologically similar species, Chondrus crispus and Gigartina stellata, the former possesses considerable degrees of antimicrobial activity whilst the latter exhibits no such activity. The results also indicate that the production of antibiotics by the algae is affected by the season of the year.

House dust mites are believed to be major triggers for allergic disease in atopic individuals. As part of a programme controlling dietary and aero‐allergen exposure in high‐risk infants, an acaricidal foam and powder (Acarosan) was applied to bedroom and main living room carpets, as well as upholstered furniture, on four occasions in the first year of life. Dust was assayed for mite antigen (Der p1) and these results compared with the semi‐quantitative assay of guanine content (Acarex Test). After nine months mean Der p1 levels had decreased by 70% in the treatment group. Proportionally, the greatest fall occurred in those items that had the highest initial mite antigen content. The Acarex score does show a correlation with Der p1 levels, but cannot replace antigen assay when accurate data is required. A chemical acaricide may help reduce house dust mite antigen levels, but is not by itself sufficient to reduce levels below that considered critical for sensitisation.

OBJECTIVE: To determine the prevalence of sensitisation to peanuts and tree nuts in all children born during one year in one geographical area. DESIGN: Birth cohort study with structured review at ages 1, 2, and 4 years. SETTING: All children born on the Isle of Wight between January 1989 and February 1990. SUBJECTS: Of 1456 children originally included, 1218 were reviewed at age 4 years. Of these, 1981 had skin prick tests. MAIN OUTCOME MEASURES: Positive skin test results, clinical atopic disease, and risk factors for the development of atopy. RESULTS: 15 of 1218 (1.2%) children were sensitised to peanuts or tree nuts (13 to peanuts). Six had had allergic reactions to peanuts (0.5% of the population), one to hazelnuts, and one to cashew nuts; three had had anaphylactic reactions. Seven children had positive skin test results or detectable IgE to peanuts without clinical symptoms. Two children who reacted to peanut in infancy had lost their sensitivity by 4 years. Family history of atopy, allergy to egg (odds ratio 9.9, 95% confidence interval 2.1 to 47.9, and eczema (7.3, 2.1 to 26.1) were important predictors for peanut allergy. CONCLUSIONS: IgE mediated allergy to peanuts is common in early childhood. In many the allergy persists but a minority may develop tolerance.

The distribution of antibiotics within the thalli of six known antibiotic-producing marine algae was investigated by collecting standard samples at various distances from their growing points and then assaying their antibiotic content. The results showed that out of the six species examined only Ulva lactuca contained a uniform distribution of antibiotic(s). Three species; Chondrus crispus, Dilsea carnosa and Codium fragile exhibited increased activity in the younger regions of their thalli whilst the frond of Laminaria saccharina was least active around its meristematic region. Laminaria digitata appears to have a more complicated distribution of activity within its thallus. The experiments were repeated at quarterly intervals but no significant seasonal variation in antibiotic distribution within these six plants could be detected.

Eleven known antibiotic-producing species of British marine algae were quantitatively screened at monthly intervals for the presence of antibacterial compounds. The antibacterial components of the algae were extracted with acetone and then assayed against Staphylococcus aureus. The results indicate that seasonal variation in antibiotic production occurs in some marine algae and also that four main patterns of production can be discerned. These are, (a) the Polysiphonia type, in which antibiotic production occurs iniformly throughout the year; (b) the Laminaria type, which is characterised by maximum antibiotic production occurring during the winter months, this is also found in Chondrus crispus, Laurencia pinnatifida and Ulva lactuca; (c) the Dictyota type, possessing a summer peak of activity, which also occurs in Dilsea carnosa and Ascophyllum nodosum; (d) the Codium type, where there is a spring peak of activity, this is also exhibited by Halidrys siliquosa.