Vascular injury, activation of the coagulation system and thrombosis are common initial events in the accelerated atherosclerotic process. The role of thrombin generated at the site of aortic injury in the subsequent neointimal proliferation was studied in rabbits (n = 16) 3 weeks after balloon catheter injury. In half of these animals, potent thrombin antagonists, r-hirudin and P-PACK, were administered to prevent acute thrombotic events. Compared to aortas with intact endothelium (n = 8), aortas de-endothelialised 21 days earlier showed neointimal hyperplasia as measured by the intimal/medial ratio (0.68 vs. 0.04, injured vs. normal aortas) and an increase in both total cholesterol (4.08 vs. 3.31 mg/g, p < 0.05) and lipid peroxide content (31.3 vs. 1.1 nmol/g; p < 0.001). Neointimal hyperplasia following endothelial denudation was inhibited in rabbits treated with thrombin-antagonists (0.27 vs. 0.68, treated vs. untreated, p = 0.012) and neither total cholesterol (3.48 mg/g) nor lipid peroxide content (1.5 nmol/g) differed significantly from that of intact arteries. By demonstrating a strong relationship between thrombin generation following de-endothelialisation and the progressive intimal proliferation, this study supports the hypothesis that thrombin is an important contributor to restenosis after vascular injury. The highly atherogenic lipid peroxidation seems to be linked to the early, thrombin-mediated events, as it was completely prevented by adequate thrombin antagonism.

Cytological and histological biopsies were obtained on 75 breast lumps clinically diagnosed as fibroadenomas. Of these, 95 per cent of lesions were benign. In 51 (68 per cent) confirmed as fibroadenomas histologically, cytology was benign in 78 per cent, but inadequate for diagnosis in 16 per cent. The remaining 24 lesions included three breast cancers and one lymph node with Hodgkin's disease. In this group cytology was inadequate for diagnosis in 54 per cent, including one breast cancer. No lesion with benign cytology was subsequently shown to be malignant. The study supports the view that clinical diagnosis and cytology are accurate in the diagnosis of benign breast disease of this type. Breast cancer may rarely present with the clinical features of a fibroadenoma and too few lesions have been studied to assess fully the performance of cytological biopsy in detecting these small mobile lesions. A non-excisional policy should therefore include prolonged follow-up and repeat biopsy.

A study was performed to evaluate the effect of low-dose aspirin (75 mg/day) on platelet reactivity in patients with peripheral vascular disease. Platelet function was measured in 31 patients with advanced peripheral vascular disease requiring surgery. Shear-induced haemostasis and collagen-induced thrombus formation were used as indicators of platelet reactivity. They were measured in non-anticoagulated fresh whole blood samples ex vivo using a haemostatometer. Results were compared with those from 30 age- and sex-matched controls. Shear-induced haemostasis and collagen-induced thrombus formation were also measured in 18 of the 31 patients before the start of aspirin administration (before operation) and 1 week after surgery. Patients with advanced peripheral vascular disease were found to have increased platelet reactivity with a mean(s.e.m.) shear-induced haemostasis index of 1977(180) mmHg s compared with a control value of 3161(234) mmHg s (P < 0.001) and a mean(s.e.m.) collagen-induced thrombus formation index of 3980(460) mmHg s compared with a control value of 5350(420) mmHg s (P = 0.02). Perioperative low-dose aspirin failed to inhibit platelet function in patients with peripheral vascular disease.

A new technique for dilatation of colorectal anastomotic strictures-wire-guided balloon coloplasty-is described. It is suitable for high strictures, may be performed without general anaesthetic and is repeatable. It does not require endoscopy and may be used to relieve obstructive symptoms in both benign and malignant strictures so avoiding the need for a defunctioning colostomy.

A 78-year old woman presented with pain in her left lower abdomen for three days. She had also noticed an associated swelling in the same area, and a feeling of incomplete evacuation of her bowel. However, there was no nausea, vomiting, change in bowel habits, or rectal bleeding. She was otherwise fit and healthy, apart from mild hypertension for which she was taking bendrofluazide. On examination, she was anaemic and pyrexial. Pulse rate was 90 beats/min and blood pressure 160/85 mmHg. Her abdomen was distended, with no scars, and normal hernial orifices. A tender, smooth, fixed, poorly outlined mass was found in the left iliac fossa. Rectal examination and sigmoidoscopy up to 12 cm were normal.Initial investigations showed haemoglobin 9.8 g/l, white blood cells 10