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.