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During femoro-popliteal and femoro-distal bypass, measurement of vascular resistance (VR) at the site of graft outflow may be used to quantify "run off". Intra-operative measurements were made in 51 lower limbs to compare VR in different categories of outflow; the "isolated" popliteal segment (IPS group, n = 11), the popliteal artery in continuity with patent vessels to the pedal arch (PIC group, n = 26) and the single calf vessel (SCV group, n = 14). VR was measured both before and after intra-arterial papaverine. The values in the 37 popliteal arteries were correlated with two different methods of arteriographic scoring. Vascular resistance in the IPS group (median 1149 mPRU, P = 0.003) but not significantly different from VR in the SCV group (median 1014 mPRU, range 743-1541 mPRU). VR in the SCV group was significantly greater than that in the PIC group (P = 0.006). After papaverine administration, the same relationships were observed between the IPS, PIC and SCV groups. Both before and after papaverine, VR in the popliteal artery correlated significantly with both arteriographic scores. In terms of VR, the isolated popliteal segment provides an outflow comparable to that of a single calf artery but less favourable than a popliteal artery wtih patent run off.

The role of antibiotics was investigated prospectively in 91 open fractures of the finger. Antibiotics were administered to alternate patients with open phalangeal fractures. Only finger fractures distal to the metacarpophalangeal joint were included. Both groups were treated with aggressive surgical irrigation and debridement. In four patients in each group clinical signs of infection eventually developed; osteomyelitis did not develop in any patients, and no secondary surgical procedures were required in either group. This data indicates that vigorous irrigation and debridement is adequate primary treatment for open phalangeal fractures in fingers with intact digital arteries.

Distal outflow vascular resistance (VR) has been measured intra-operatively during 67 infrainguinal bypass procedures to establish whether it might have a role as a predictive test for early graft thrombosis. The graft outflow was popliteal artery above the knee (48), popliteal artery distal to the knee (6) or a single calf vessel (13). VR was measured before anastomosis of the graft, calculated from the relationship between pressure and flow in the outflow artery during infusion of the patient's own blood at a constant rate. VR was measured before and after vasodilation with papaverine. Primary graft patency at 30 days was documented. In the 10 limbs in which graft thrombosis occurred, VR was 1167 +/- 367 mPRU, significantly higher than VR in 57 limbs with a patent graft, 850 +/- 310 mPRU (P = 0.02, Mann-Whitney U test). After papaverine, VR was 823 +/- 368 mPRU in the limbs with a thrombosed graft, significantly higher than that of limbs with a patent graft, 463 +/- 211 mPRU (P = 0.001). VR appeared to show most promise as a predictor of early thrombosis in the group of femoro-tibial and femoro-peroneal grafts. In this group, the value of 800 mPRU after papaverine was 92% efficient and was 80% sensitive, 100% specific and had a predictive value of 100% for early thrombosis. Distal outflow VR is an important factor in early graft thrombosis and might have a practical application as a predictor of early thrombosis of femoro-distal bypass grafts.

Twenty-six patients (age range 40-88 years) with saddle embolism, representing 11% of cases of peripheral embolism, were treated during an 8-year period. A proven intra-cardiac source, including atrial fibrillation and post-infarction mural thrombosis, was observed in 22 cases (85%). The ambiguities in the clinical presentation of saddle embolism were sometimes responsible for delayed recognition. On confirmation of the diagnosis an IV heparin regime was immediately commenced followed by surgery. Our practice of initiating treatment of saddle embolism with immediate systemic heparin infusion resembles that of Blaisdell et al. In contrast, we also advocate a policy of early surgical intervention. Bilateral trans-femoral explorations were undertaken in 21 cases and direct aorto-iliac procedures in five cases. Recurrent embolism occurred in 27% of cases despite postoperative anticoagulant therapy. An overall limb salvage rate of 88.5% was recorded. The postoperative mortality of 30% was accounted for by primary cardiac disease and multiple organ failure. The influence of multiple and recurrent embolism and cardiac instability on the eventual outcome is signifcant. A policy of early systemic heparin therapy and surgery in the management of saddle embolism, enhances limb survival and prevents renal failure.

The clinical and histological findings in 15 cases of carcinoma arising from the extrahepatic biliary tract are reviewed. The clinical findings are in agreement with previously reported series and the dismal prognosis is confirmed. The prognosis does not appear to be related to tumour size, site, mitotic count or laboratory data on presentation. Only histological grading of the tumour is related to prognosis. Perineural tumour infiltration was a prominent feature and dysplasia within adjacent bile duct epithelium was present in five cases. The value of carcinoembryonic antigen (CEA) as a histological tumour marker was investigated. All tumours from the upper and middle biliary tree expressed this antigen. Although immunocytochemistry is seldom needed to assess malignancy in large surgical resection specimens anti-CEA helps delineate the extent of tumour infiltration and discriminates between normal and dysplastic or malignant epithelium; anti-CEA may also be helpful in identifying foci of malignancy in small sclerotic biopsy specimens.

Preoperative acid studies and early postoperative insulin tests in 275 patients undergoing various forms of vagotomy have been related to recurrent ulceration. Follow-up time has been from two to nine years, mean 4-3 years. Recurrence is directly related to basal acidity in both tests but is not related to stimulated acid levels preoperatively. In the insulin tests higher levels of acidity after insulin are associated with a higher incidence of recurrence. When positive, Hollander's and multiple criteria are both associated with a higher recurrence rate.

The N-terminal sequences from heavy variable regions of 47 myeloma proteins of the NZB mouse have been analyzed. Sixteen of these VH regions have unblocked alpha amino groups and have been analyzed over their N-terminal 20 residues by automatic sequence analysis. These sequence data along with the antigen-binding profiles and immunoglobulin class distribution are compared with comparable data from BALB/c myeloma proteins. These comparisons suggest that the NZB and BALB/c populations of myeloma proteins are distinct from one another. The genetic implications of this conclusion are discussed.

A Monte Carlo-type simulation of the evolution of a multigene family was performed. The model was designed to study the selective forces which may control the size of a multigene family. As expected, we find that direct selection on the size of the multigene family can control its size. More important, we find that selection acting upon the family as a single functional unit, in conjunction with homologous but unequal crossing over, can also control the size of a multigene family.

Structural and functional analyses of myeloma immunoglobulins from inbred BALB/c mice and humans have provided important insights into the structure of the antibody molecule and the expression and evolution of antibody genes. One important question concerning these analyses is whether the myeloma process selects, in a nonrandom manner, the lymphocytes to be transformed. The availability of myeloma tumors in a second inbred strain of mouse, NZB, permits us to approach this question. In this respect. the NH2-terminal amino acid sequences of 27 kappa light chains as well as data relating to the antigen-binding properties and immunoglobulin class distribution of NZB myeloma proteins are presented and compared with similar data from the BALB/c mouse. These studies suggest that the myeloma proteins from the BALB/c and NZB mice constitute two populations of immunoglobulins with distinct functional and structural properties. The implication of this observation are discussed.

Seven cases of fistula developing between aortic or iliac aneurysms and adjacent major venous trunks are presented. The clinical diagnosis and principles of management of this exceptionally rare complication are discussed in the light of the literature on the subject.

The results of treatment in 34 cases of penetrating injury to the popliteal vein are presented. In 26 cases there was associated damage to the popliteal artery. Satisfactory venous repair by lateral suture was achieved in 11 of 12 limbs. Autogenous vein grafts were used to repair the damaged popliteal vein in 10 limbs. In 4 the saphenous vein was anastomosed directly to the popliteal vein; in 6 cases it was used as a wide-bored panel or compilation graft. Three popliteal veins were ligated. Major postoperative limb oedema and chronic venous insufficiency were not a problem in those cases where the veins were repaired. Fasciotomy was performed in 19 of the 34 cases of venous injury. In 12 of these cases fasciotomy, performed as part of the original operation to repair the vascular injury, led to an excellent clinical result.

In this article, we develop a mathematical approach for the analysis of diversity in antibody gene families. This approach is arrived at by examing two general questions about protein populations: (1) What is a relative measure of the diversity exhibited by one protein family when compared with a second? (2) What is the probability that two protein populations were derived from a single common population? These quantitative approaches permit a variety of precise evolutionary, genetic, and developmental questions to be asked of antibody gene families. Using this methodology, we demonstrate that the diversity in mouse K-immunoglobulin chains is considerably greater than in their human K counterparts. We also show that the variable (Vl) regions of light chains associated with IgG and IgA immunoglobulins in the mouse appear to have been derived from a common population of Vl genes. This approach also can be used to analyse sequence data from other informational multigene families.

Military experience has consistently emphasized the unacceptably high amputation rate associated with popliteal arterial trauma. In this group of patients there were 23 arterial injuries and 26 injuries involving both an artery and a vein. The loss of only 5 limbs in this series was directly related to the policy of repair of the artery by both single segment vein grafts and by 'panel' grafts. Panel grafts are prepared by removing the long saphenous vein at ankle level, splitting it longitudinally and then dividing it transversely at the midpoint. The two segments of vein are placed side by side and sutured along each side, a no. 14 or 16 Ch. Foley catheter being used as a stent. Fasciotomy, carried out at an early stage in the postoperative course, and prompt re-exploration of repair sites when suspicion arose as to the effectiveness of limb circulation, were also major factors in establishing a successful outcome in so many patients.

The amino acid sequence of beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) has been compared to itself and to other proteins. Two segments, each of about 380 amino acids, comprising the first three-fourths of the polypeptide chain, were found to be very similar to each other. It is concluded that they are homologous. The carboxyl-terminal fourth has a high percentage of amino acid identities with dihydrofolate reductase of Escherichia coli, suggesting these sequences also are homologous. A model for the origin of beta-galactosidase is presented. The overall similarity of beta-galactosidase to lac repressor does not appear to be significant.