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A theoretical debate about whether parasitoids should be time or egg limited now recognizes both as feasible, and interest has turned to determining the circumstances under which each might arise in the field, and their implications for parasitoid behaviour and evolution. Egg loads of parasitoids sampled from the field are predicted to show a negative response to host availability, but empirical support for this relationship is scarce. We measured how a parasitoid's egg load responded to seasonal fluctuations in host population density and recorded the predicted correlation. In early summer, parasitoids were at high risk of time limitation due to low host availability, and in late summer, their offspring were at greater risk of egg limitation due to high host availability. Despite clear seasonal changes in selection pressures on egg load and lifespan, the parasitoid showed no evidence of seasonal variation in its reproductive strategy. We made minor modifications to a previously published model to explore the effects of seasonal variation in host availability on optimal investments in eggs and lifespan and obtained several new results. In particular, under circumstances analogous to some of those observed in our field study, temporal stochasticity in reproductive opportunities can cause investments in eggs to increase, rather than decrease as previously predicted. Our model results helped to explain the parasitoid's lack of a seasonally varying reproductive strategy. Understanding the evolution of parasitoid egg load would benefit from a shift of research emphasis from purely stochastic variation in parasitoid reproductive opportunities to greater consideration of host dynamics. [ABSTRACT FROM AUTHOR]

A 50-year-old man with recurrent life-threatening sepsis and a cutaneous condition resembling pyoderma gangrenosum, was found to have a defect of neutrophil phagocytic function. Phagocytosis could be enhanced by corticosteroids, both in vivo in a dose-dependent manner, and in vivo, when it was accompanied by rapid clinical improvement. Studies with steroid hormones and immuno- stimulatory drugs arc described. [ABSTRACT FROM AUTHOR]

Four African female patients are described, who presented with the features of systemic sclerosis. Overlapping features of lupus erythematosus or dermatomyositis were present in three cases but were not prominent. Direct immunofluorescence of uninvolved skin revealed a particulate (or speckled) epidermal nuclear staining, with specificity for IgG. In view of the reported association between this finding and mixed connective tissue disease, these patients were treated with corticosteroids and marked improvement occurred in all cases. The usefulness of this investigation in making the distinction between systemic sclerosis and mixed connective tissue disease and in indicating a potentially effective form of therapy is discussed. [ABSTRACT FROM AUTHOR]

This article reports that vasculitis may be an important histological feature of chronic urticaria associated with systemic disease. Researchers found that vasculitis could be induced in the skin of several patients with essential acquired cold urticaria, by repeated cold challenge, as performed during cold-tolerance treatment. In five patients after repeated cold challenge, histological examination of 1 micrometer plastic sections revealed features of early vasculitis principally affecting venules in middle and deep dermal zones and subcutaneous tissue. The endothelial cells were swollen or vacuolated and separated by gaps often containing blood cells.

This article reports on the case study related to transient acantholytic dermatosis. The subject is a male, aged 65 years. In December 1974 he first developed a pruritic rash, predominantly on the upper trunk with the axillae, neck, periumbihcal area, upper arms and thighs also involved. At first he had many small blisters, but these no longer occur, although the pruritic rash has persisted, in spite of the use of antihistamines, topical steroids and dapsone. On examination. Small pin-head vesicles were present originally on the upper trunk, but more recently only excoriated papular lesions have been observed.

The article reports the inhibitory influence of the cromone-like drug doxantrazole on cold-stimulated histamine release and urtication in patients with cold urticaria. Six patients with cold urticaria who had immediate wealing responses to skin cooling were studied. The arm was cooled by water immersion at a predetermined temperature before and after systemic administration of doxantrazole. Histamine in venous blood draining the cooled forearm skin was measured by bio- assay using a cascade superfusion method as previously described. That doxantrazole reduces evoked histamine release from skin mast cells was further suggested by reduction in the flare reaction to intradermal injection of the histamine liberator compound 48/80 in patients receiving doxantrazole.

Presents an abstract of the article "Are Moles Just Naevus Cells?," by C. B. Bentley-Phillips and R. Marks.

Laboratory host specificity of 2 biological control agents, already introduced in New Zealand, was compared with actual field parasitism.The parasitoids were Microctonus aethiopoides Loan and Microctonus hyperodae Loan, braconids imported to control the curculionid forage pests Sitona discoideus Gyllenhal and Listronotus bonariensis (Kuschel), respectively. The nontarget weevil species tested included native,introduced, and beneficial species. M. aethiopoides oviposited in 11of the 12 species to which it was exposed and successfully parasitized 9 species. M. hyperodae oviposited in 5 of the 11 species to whichit was exposed and developed successfully in 4 species. Higher percentage parasitism was recorded with M. aethiopoides than with M. hyperodae. Field collections of weevils from Otago, Canterbury, and Waikato indicated that 10 New Zealand natives and 3 other nontarget species, including the weed biological control agent Rhinocyllus conicus (Froehlich), were parasitized by M. aethiopoides. M. hyperodae has been found parasitizing 1 native species, as well as Sitona lepidus Gyllenhal, which was accidentally introduced to New Zealand recently. In nontarget species, parasitism levels in the field of >70% have been recorded for M. aethiopoides and <5% for M. hyperodae. The results of this study suggest that laboratory host range testing is indicative of nontarget parasitism in the field. [ABSTRACT FROM AUTHOR]