Scientific discourse, in public.

The experience of writing for a wider audience has benefits and drawbacks. Attempting to make scientific issues more accessible to non-scientists is no easier than explaining them to peers. Indeed, explaining toxicological data such as solvent measurements from a hazardous waste site can be even more difficult, especially in addressing those living next to the site. Alastair Hay reconsiders his experience in two cases that brought toxicology under public scrutiny.     

Experimental dermatophytosis in mice: correlation between light and electron microscopic changes in primary, secondary and chronic infections

The histopathological and electron microscopic features of experimental dermatophytosis due to Trichophyton quinckeanum in Balb/c mice have been studied in animals with primary, secondary and chronic infections. Infected animals all showed pathological changes with adherence of microconidia to keratinocytes within 4 h of infection. Other features were the early infiltration of neutrophils, the formation of a mycelial mass (scutulum) in the epidermis, and epidermal oedema. Increased thickness of the epidermis was measured within 3 days of infection, although this was mainly due to oedema. The main differences seen in secondary infections were the paucity of fungal elements, even after 24 h, a sustained increase in epidermal thickness, and the dense dermal infiltrate of mononuclear cells. Chronically infected animals showed similar changes to those at the peak of a primary infection, but in addition there were large numbers of mast cells in the dermis. Cells carrying Ia markers were identified in the epidermis (Langerhans cells) and the dermis (macrophages) in all infections and their distribution did not appear to change. Although recovery from infection has been correlated previously with T lymphocyte mediated responses an increase in the number of cell layers of the epidermis and a dense infiltrate of neutrophils at the zone of infection were both seen within 2 days of infection. It is suggested that neutrophil killing of fungi and increased epidermal proliferation, not dependent on T cell activation, may also be implicated in host defence against dermatophytes.     

Photocoagulation using the Eisner cone

Thirteen patients with clinical or subclinical retinal detachments were treated with photocoagulation with the aid of a device for scleral depression and the three mirror contact lens. The Eisner cone has proven helpful in achieving clinically white retinal burns at the margins of retinal breaks by displacing subretinal fluid at the time of treatment. Patients selected for treatment had adequate pigmentation for a good photocoagulation response, nearly clear ocular media, and minimal vitreo retinal traction. Extent of retinal detachment was not a determinant, but minimal retinal elevation at break locations proved beneficial. No immediate flattening or adhesion of the retina was seen on release of scleral depression at the time of photocoagulation. White clinical burns remained visible. In 12 of 13 patients the retina was in apposition to the retinal pigment epithelium around the breaks at the first post-treatment examination. The remaining subretinal fluid absorbed in even the most extensive detachment in 2 weeks. One patient with multiple breaks at the equator failed to respond to this technique and required a scleral buckle.     

Electroconvulsive Therapy in the Medically Ill Elderly

Treatment with electroconvulsive therapy (ECT) of medically ill geriatric patients with affective disorders is described. Of 135 patients to whom ECT was administered in 6 years, 55% were over 60 years of age. One-third (45) exhibited cardiovascular (62%), central nervous system (15%), or other medical conditions (22%) increasing the risks of the treatment. Treatment strategies are described.     

Abrogation of adriamycin-induced cardiotoxicity by selenium in rabbits.

Adriamycin-induced cardiomyopathy in rabbits was produced by intravenous injections of the drug with a short therapeutic schedule (3 mg/kg body wt administered as four intermittent doses). Animals receiving selenium supplementation of Adriamycin showed preservation of the normal pattern of the heart histologic picture. The protective effect of selenium was accompanied by increased selenium levels in the plasma and the heart muscle. An eventual interaction between the antitumor effect of Adriamycin and the protective effect of selenium was ruled out by in vitro experiments using the L1210 cell line. Selenium did not abrogate the antiproliferative effect of Adriamycin when the cells were treated simultaneously with both agents. The results from this study indicate that Adriamycin-induced cardiotoxicity could be prevented by selenium if the animals were pretreated with selenium, rather than simultaneous administration of both agents. The mechanism of this effect is not entirely understood.