An antigen detection system, termed immuno-polymerase chain reaction (immuno-PCR), was developed in which a specific DNA molecule is used as the marker. A streptavidin-protein A chimera that possesses tight and specific binding affinity both for biotin and immunoglobulin G was used to attach a biotinylated DNA specifically to antigen-monoclonal antibody complexes that had been immobilized on microtiter plate wells. Then, a segment of the attached DNA was amplified by PCR. Analysis of the PCR products by agarose gel electrophoresis after staining with ethidium bromide allowed as few as 580 antigen molecules (9.6 x 10(-22) moles) to be readily and reproducibly detected. Direct comparison with enzyme-linked immunosorbent assay with the use of a chimera-alkaline phosphatase conjugate demonstrates that enhancement (approximately x 10(5)) in detection sensitivity was obtained with the use of immuno-PCR. Given the enormous amplification capability and specificity of PCR, this immuno-PCR technology has a sensitivity greater than any existing antigen detection system and, in principle, could be applied to the detection of single antigen molecules.

From 1977 to 1997, surgical resection was possible in 142 (80%) of 177 patients with hilar cholangiocarcinoma after relieving jaundice by single or multiple percutaneous transhepatic biliary drainage followed by percutaneous transhepatic cholangioscopy and/or percutaneous trans-hepatic portal vein embolization. Curative resection was possible in 108 (61%) of the 142 patients, and 100 of these patients underwent various types of hepatectomy with caudate lobectomy for a 30-day operative mortality rate of 6% and 9% hospital mortality. Combined portal vein resection was carried out in 43 cases including 41 hepatectomies and 2 bile duct resections. Hepatopancreatoduodenectomy was performed in 16 patients. Cancer recurrence was observed in 58 of the 108 patients undergoing curative resection. The 3-, 5-, and 10-year survival rates for 100 patients undergoing curative hepatectomy and 8 with curative bile duct resection were 43%, 26%, and 19%; and 31%, 16%, and 0%, respectively; those for 40 patients with positive lymph node metastasis, 84 with perineural invasion, and 43 with combined portal vein resection were 27%, 14%, and 7%; 34%, 21%, and 13%; and 18%, 6%, and 0%, respectively. These survival rates are significantly better than those for 35 patients with unresectable cancer. Curative resection after aggressive preoperative management is recommended as a reasonable surgical approach to hilar cholangiocarcinoma.

Heme oxygenase is a heme-oxidizing enzyme which generates biliverdin and carbon monoxide (CO). The present study was designed to elucidate whether CO endogenously produced by this enzyme serves as an active vasorelaxant in the hepatic microcirculation. Microvasculature of the isolated perfused rat liver was visualized by dual-color digital microfluorography to alternately monitor sinusoidal lining and fat-storing Ito cells. In the control liver, the CO flux in the venous effluent ranged at 0.7 nmol/min per gram of liver. Administration of a heme oxygenase inhibitor zinc protoporphyrin IX (1 ,uM) eliminated the baseline CO generation, and the vascular resistance exhibited a 30% elevation concurrent with discrete patterns of constriction in sinusoids and reduction of the sinusoidal perfusion velocity.The major sites of the constriction corresponded to local sinusoidal segments colocalized with Ito cells which were identified by imaging their vitamin A autofluorescence. The increase in the vascular resistance and sinusoidal constriction were attenuated significantly by adding CO (1 ,uM) or a cGMP analogue 8-bromo-cGMP (1 ,uM) in the perfusate. From these findings, we propose that CO can function as an endogenous modulator of hepatic sinusoidal perfusion through a relaxing mechanism involving Ito cells. (J. Clin. Invest. 1995. 96:2431-2437

ABSTRACT

Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.