The mortality and morbidity of 151 elderly patients (greater than 64 years of age) undergoing biliary surgery for benign disease were prospectively studied. The overall mortality was 3.3 per cent. This comprised a 0.77 per cent mortality in the elective group and a 19 per cent mortality in the emergency group. In spite of 77 per cent of the emergency group having a gangrenous gallbladder, a complication difficult to predict preoperatively, the majority of deaths were from cardiovascular disease. The overall incidence of common bile duct exploration was 36 per cent, which was similar in the elective and emergency groups. A comparison between the old (65-74 years) and the aged (over 74 years of age) revealed twice the number of emergency cases in the aged. Considering elective biliary surgery, there was no difference between the mortality, morbidity, or common bile duct exploration rate comparing the old with the aged. This suggests that elective biliary surgery is safe even in the aged.

Aptamers are proving their utility in a number of applications. However, to be easily functionalized, their structure needs to be simplified. Therefore, we sought to truncate a 50-nucleotide aptamer specific to the transferrin receptor to its smallest functional unit using rational engineering of the predicted two-dimensional structure of the longer parent sequence. In addition, mutations were introduced into the binding loop to determine their effect on the selectivity of the aptamers. These base mutations enhanced the binding affinity of the aptamer, while retaining its specificity. The equilibrium dissociation constant (Kd) was reduced sixfold following the substitution of all four bases in the binding region. In addition, these aptamers were efficiently internalized into transferrin receptor-positive cells in a similar manner to the transferrin receptor antibody and demonstrated colocalization with this antibody. This study has shown that the smallest functional unit of this aptamer was 14 nucleotides. This small size will be advantageous for future applications, such as drug delivery or functionalization of other therapeutic modalities.

Fifty-six patients, 30 with superficial and 19 with deep groin wound infections, and seven with lymph fistulae with positive cultures within 30 days of arterial surgery, were identified after 661 operations (873 groins at risk) between September 1984 and August 1988. The commonest infecting organisms were Staphylococcus aureus, Pseudomonas aeruginosa and Proteus spp. In 33 patients the infection settled completely after treatment with culture specific antibiotics. These were given intravenously then orally for up to 6 weeks. Sixteen patients required debridement and excision of necrotic wound edges, including one who had an antibiotic infusion into the wound. Graft excision was performed in seven patients of whom five received an extra anatomic bypass. The need for graft excision was much greater (six versus one) for Dacron and/or polytetrafluoroethylene than for vein. In two lymph fistulae sartorius transposition and wound resuture were used. All groins healed, though three extremities were ischaemic following occlusion of the bypass. There were two deaths, one from myocardial infarction and one from pulmonary embolism and no major amputations. These results suggest that most infective groin problems may be successfully managed conservatively and that radical graft excision is only necessary for a few intractable cases.

The effect of duodenogastric reflux on cell proliferation and mucosal mass in the stomach was studied. Male Wistar rats (n = 118) were submitted to Polya partial gastrectomy, partial gastrectomy with Roux-en-Y diversion of bile, total duodenogastric reflux or handling of the stomach alone (sham operation). Following oral administration of the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine for 6 months, animals were killed 6, 9 or 12 months postoperatively and their stomachs were examined for crypt cell production rate and mucosal DNA content. Compared with shams, crypt cell production rate was more than twice as high in the gastric remnant 12 months after Polya partial gastrectomy (P less than 0.001) and median DNA content was 31 per cent greater (P = 0.05). After total duodenogastric reflux, DNA content was 62 per cent greater than in shams (P = 0.02), while Roux-en-Y diversion reduced crypt cell production rate by 65 per cent (P less than 0.001). Only Polya gastrectomy increased the number of rats developing gastric carcinomas (9 versus 2 shams; P less than 0.05). Increased mucosal cell proliferation in rats with duodenogastric reflux may help to explain the development of gastric stump cancer.

Multiple gastric biopsies and gastric juice aspirates were taken in 108 patients undergoing routine or review gastroscopy for a variety of upper gastrointestinal disorders. The gastric juice was measured for free and total bile acids and the biopsies examined for premalignant mucosal changes. Total bile acid levels were significantly higher in patients with atrophic gastritis, intestinal metaplasia and dysplasia but not chronic gastritis. There was no correlation between the severity of the dysplasia and total bile acid levels. Free bile acid levels were significantly higher in patients with atrophic gastritis but not in patients with chronic gastritis, intestinal metaplasia or dysplasia. These results suggest that intragastric bile acids may be implicated in premalignant histological changes of gastric mucosa and thus play a part in gastric carcinogenesis.

Following endoscopic gastric juice aspiration, intragastric bile acids were measured in 105 patients undergoing routine or review gastroscopy. Subsequently, duodenogastric reflux was assessed using 99mTc butyliminodiacetic acid (BIDA) scintigraphy and intragastric bile acid levels compared with the grades of reflux assessed scintigraphically. There was a significant correlation between both free and total intragastric bile acid levels and the degree of radiological bile reflux, especially when reflux was severe. Both endoscopic measurements of bile acids and BIDA scintigraphy appear to be useful methods for determining duodenogastric reflux, but neither may be accurate enough to quantify minor degrees of reflux.

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but a low titre to the porcine agent.3 Before operation a test dose was given to ascertain the therapeutic response and to detect side effects.4 In this case shivering, nausea, and back pain occurred but were rapidly relieved by oral chlorpheniramine. During the early postoperative period we gave 100 mg hydrocortisone and 10 mg chlorpheniramine intravenously before each infusion, later using chlorpheniramine alone. The platelet count remained unchanged. Altogether 270 000 units of porcine factor VIII were given without any appreciable rise in the titre of antibodies to this agent or an increased tendency towards side effects.Though a prolonged conservative approach to management of a pseudotumour may be successful, it was clearly failing in this patient. The new porcine factor enabled us to overcome the problem of achieving and maintaining haemostasis during and after major surgery.We thank Professor R B Duthie and Dr C Rizza for permission to report on their patient and for their helpful advice. Weight gain after cholecystectomyCholecystectomy is currently the most common major general surgical operation, with about 45 000 operations being performed each year in the United Kingdom.' A retrospective study of patients undergoing biliary surgery in this hospital suggested that many patients gain weight after cholecystectomy (paper in preparation). We therefore undertook a prospective study to examine weight change after cholecystectomy. Methods and resultsOne hundred and three patients undergoing elective operations for benign biliary disease were entered into the study. None had acute cholecystitis immediately before their operation. The patients comprised 31 men and 72 women with mean ages of 57 (range 32-75) and 53 (16-81), respectively.One patient died postoperatively (mortality 10o'), after the leakage of a choledochoduodenostomy. The patients were weighed in their underclothes and a light dressing gown on the day before operation and six weeks, three months, and six months after discharge from hospital.Six months after operation 75 of the patients had gained weight, 21 had lost weight, and seven remained at their preoperative weight. The table shows the mean weights over the six month study period. An increase in weight was apparent at three months, although this had no significance until six months. The patients were subdivided to see whether the weight changes were related to sex, preoperative body weight, or age. Twenty seven (870o) of the men gained weight compared with 49 (680 ) of the women, a difference that was not significant (X2 test). The men lost a little weight in the first six weeks after operation but then showed an increase at three months and a significant gain at six months (paired Student's t test). The women gained weight steadily, but the increase was not significant until six months postoperatively. In both sexes preoperative obesity, which we arbitrarily defined as over 70 kg in women and 80 kg in men, did not appear to influence weight gain. When patients aged below 65 were compared ...