of an operation BI 2536 does not necessarily foretell the subsequent development of infection. Wounds found at operation to be contaminated by coagulase positive staphylococci had the highest infection rates, but only 26.7 per cent of the infections that occurred at the hospital that conducted this special survey yielded coagulase positive staphylococci, and they were not always the same as those isolated during the operation THE pathogenesis of human idiopathic periductal mastitides is obscure. Morphologically they present a varied picture, which is reflected in the different descriptive terms that have been applied to them. However, as they are widely felt to represent the same disease process, the generic term periductal mastitis is used here.
The sterility of the lesions, in the absence of fistulation, does not support an infective origin. Though chemical irritation Sunitinib by retained duct secretions has been suspected, it has been postulated that bovine and human periductal mastitides may have an autoallergic basis. The conflicting experimental results obtained after auto and iso immunization in lactating and oestrogenized rabbits prompted the experiments described here, using oestrogenized rats. The procedure adopted was to examine the mammae of oestrogenized intact female rats, together with appropriate control animals, at intervals after administration of a single dose of a saline homogenate of allogeneic lactating mammae emulsified with Freund,s complete adjuvant. MATERIALS AND METHODS Aninmals.
Colony bred female albino Wistar rats housed in the Department of Pathology, St Bartholomew,s Hospital, London, were fed tap water and PRM dietary pellets ad libitum. Those examined histologically were aged 12 20 weeks at sacrifice. Experimental procedure. When 6 weeks old the rats were etherized and 10 mg of oestrone crystals were implanted s.c. in the dorsal interseapular region. Six weeks later 0.1 ml doses of water in oil emtulsions of Freund,s adjuvants, and saline or organ homogenates were injected intradermally into the base of the tail or a foot pad. To some animals 0 05 ml of pertussis vaccine was administered s.c. close to the intradermal site of inoculation. Thereafter the animals were sacrificed by ether anaesthesia and cervical fracture 3, 7, 14, 21, 28, 35, and 56 days after the time of inoculation.
Preparation and quantitative examination of mammaue. Immediately post mortem the major part of the thoracic, abdominal and inguinal mammae were removed intact attached to a skin pelt. The pelts were resected by means of 3 consecutive incisions: a midline ventral mandibulo pubic incision, a lateral incision from the posterior end of the ventral incision to pass posterior to the hind inguinal teat thence close to the anterior aspect of the thigh. The third incision passed anteriorly through the hind and lateral wing of the abdominal mammary fat pad to include the medial bodies of the thoracic mammae in the pelt. The pelts were then fixed for upwards of 24 hours in 10 formalin in saline. In all cases the entire hind mammae on the pelt were separated, processed and impregnated in paraffin, in some instances the thoracic mammae were similarly treated. From the centre of each block a single nominally 5,gm thick s