4
LABORATORY MEETING
This patient may be in a reactive state ; but the" possibility of sulphone and other drug resistances is being investigated, with the aid of Dr. R. J. W. Rees and Dr. M. F. R. Waters ol the National Institute of Medical Research, by using mouse foot pad infections.
DEPARTMENT OF PARISITOLOGY AND ENTOMOLOGY
Dr. E. B. Beckett (Histology Dept., University of Liverpool), Mr. W. W. Macdonald (Liverpool School of Tropical Medicine) and Dr. B. Boothroyd (Histology Dept., University of Liverpool). The histochemistry of Aedes aegypti infected with sub-periodic Brugia
malayi T h e distribution of protein-bound amino and sulphydryl groups, and of the enzyme aminopeptidase, was studied histochemically in the thoraces of Aedes aegypti infected with sub-periodic Brugia malayi larvae. The highest concentration of amino groups occurred in the distal portion of the mosquito salivary glands. Slightly less activity was present in indirect flight muscle and tubular muscle, and less still in the alimentary tract, the proximal parts of the salivary glands and the thoracic ganglia. T h e distribution of sulphydryl groups was essentially similar except that the concentration in the distal parts of the salivary glands did not always exceed that in the muscle celis. Aminopeptidase activity was found solely in the mosquito alimentary tract, a high concentration being found in t h e apices of the midgut epithelial cells and rather less in the proventricular epithelium. T h e larvae of B. malayi grow to maturity in the indirect flight muscles of Ae. aegypti, and usually cause no histologically-detectable damage to the muscle fibres beyond forming holes which they themselves occupy. T h e concentration of sulphydryl and amino groups in the muscle tissue was unaffected by the presence of the larvae, and aminopeptidase activity remained strictly localized within the midgut epithelial cells. Within the larvae, both sulphydryl and amino groups appeared to have a fairly uniform distribution, except that, because its protein framework is reticulate, the glandular region of the larval oesophagus was less reactive than the rest of the larva. T h e larvae contained no aminopeptidase. Examination of isolated larvae of B. pahangi, sectioned and stained with the periodic acid-Schiff technique, showed that larval muscle cells are very rich in glycogen.
Mr. B. R. C o o k : Echinococcus in Great Britain A series of photographs was shown, iUustrating the development of scavenging habits by sheep in the mining valleys of South Wales. This adaptation has produced a population of sheep that live entirely in the towns and villages and feed on refuse in the built-up areas o r on adjacent refuse tips. Such sheep die in or near the built-up areas, where there are many dogs running free. Although most of these dead sheep are hygienically disposed of, some remain to be scavenged by dogs. These circumstances may be associated with hydatid infection in man. T h e infection rate with Echinococcus granulosus in town dogs in Glamorgan is about 10 %.
SCHOOL OF TROPICAL MEDICINE,
BANGKOK
Dr. Rawewan Jarumilinta and Dr. Tranakchit Harinasuta : (Faculty of Tropical Medicine, Bangkok and Ciba Ltd., Basel) A m o e b i c liver abscess Successful treatment with C I B A 32 644 BA plus aspiration of amoebic liverabscess (E. histolytica found in pus) showing reduction of abscess cavity in 45 days. Dr. Pricha Charoenlarb, Dr. Supat Sucharit and Professor C h a m l o n g Harinasuta: Plant hosts of Mansonia vectors of Brugia malayi I n Chumporn (S. Thailand) Scirpus grossus, Hymenachne pseudointerrupta and Carex sp. are common and successful hosts of larvae of Mansonia uniformis, the principal local vector o f Brugia malayi A Table a n d photographs were demonstrated