Pneumoperitoneum after Endoscopic Retrograde Cholangiopancreatography due to Rupture of Intrahepatic Bile Ducts and Glisson's Capsule in Hepatic Metastasis: A Case Report and Review of Literature.

INTRODUCTION: Endoscopic retrograde cholangiopancreatography (ERCP) has been proven to be a safe and effective method for diagnosis and treatment of biliary and pancreatic disorders. Major complications of ERCP include pancreatitis, hemorrhage, cholangitis, and duodenal perforation. We report a third case in literature of pneumoperitoneum after ERCP due to rupture of intrahepatic bile ducts and Glisson's capsule in a peripheral hepatic lesion. CASE REPORT: A 50-year-old male with a history of metastatic pancreatic neuroendocrine tumor and who had a partially covered metallic stent placed in the biliary tree 1 year ago presented to the oncology clinic with fatigue, abdominal pain, and hypotension. He was planned for ERCP for possible cholangitis secondary to obstructed previously placed biliary stent. However, the duodenoscope could not be advanced to the level of the major papilla because of narrowed pylorus and severely strictured duodenal sweep. Forward-view gastroscope was then passed with careful manipulation to the severely narrowed second part of the duodenum where the previously placed metallic stent was visualized. Balloon sweeping of stenting was done. Cholangiography did not show any leak. Following the procedure, the patient underwent CT scan of the abdomen that showed pneumoperitoneum which was communicating with pneumobilia through a loculated air collection in necrotic hepatic metastasis perforating Glisson's capsule. The patient was managed conservatively. CONCLUSION: In our case, pneumoperitoneum resulted from rupture of intrahepatic bile ducts and Glisson's capsule in hepatic metastasis. This case emphasizes the need for close clinical and radiological observation of patients with hepatic masses (primary or metastatic) subjected to ERCP.

Comparative Effectiveness of Tumor Response Assessment Methods: Standard of Care Versus Computer-Assisted Response Evaluation.

PURPOSE: To compare the effectiveness of metastatic tumor response evaluation with computed tomography using computer-assisted versus manual methods. MATERIALS AND METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, 11 readers from 10 different institutions independently categorized tumor response according to three different therapeutic response criteria by using paired baseline and initial post-therapy computed tomography studies from 20 randomly selected patients with metastatic renal cell carcinoma who were treated with sunitinib as part of a completed phase III multi-institutional study. Images were evaluated with a manual tumor response evaluation method (standard of care) and with computer-assisted response evaluation (CARE) that included stepwise guidance, interactive error identification and correction methods, automated tumor metric extraction, calculations, response categorization, and data and image archiving. A crossover design, patient randomization, and 2-week washout period were used to reduce recall bias. Comparative effectiveness metrics included error rate and mean patient evaluation time. RESULTS: The standard-of-care method, on average, was associated with one or more errors in 30.5% (6.1 of 20) of patients, whereas CARE had a 0.0% (0.0 of 20) error rate ( P < .001). The most common errors were related to data transfer and arithmetic calculation. In patients with errors, the median number of error types was 1 (range, 1 to 3). Mean patient evaluation time with CARE was twice as fast as the standard-of-care method (6.4 minutes v 13.1 minutes; P < .001). CONCLUSION: CARE reduced errors and time of evaluation, which indicated better overall effectiveness than manual tumor response evaluation methods that are the current standard of care.

Incidental Extraspinal Findings at Lumbar Spine Magnetic Resonance Imaging: A Retrospective Study.

STUDY DESIGN: Retrospective study of a consecutive series of patients undergoing lumbar spine magnetic resonance imaging (MRI) for low back pain at a single institution. OBJECTIVE: To determine the prevalence and nondetection rate of incidental extraspinal findings (IESFs) in adult patients undergoing MRI of the lumbar spine performed for low back pain by using a structured approach. SUMMARY OF BACKGROUND DATA: Extraspinal findings are depicted on lumbar spine magnetic resonance image. There is limited evidence concerning their prevalence, importance, how often they are missed by interpreting physician, and how to improve their detection. METHODS: Our study was approved by our institutional review board committee, which waived informed consent because it was retrospective. Lumbar spine magnetic resonance images obtained for low back pain at our institution from January 2011 to December 2013 were assessed by 3 readers for IESFs using a structured approach and their results compared with the archived reports. Repeat lumbar spine MRI and cases with a history of trauma were excluded. A total of 3024 lumbar spine magnetic resonance images were included. IESFs were classified according to the organ involved and to the model adopted by the modified CT Colonography Reporting and Data System (C-RADS). Nondetection rates were determined by comparing the results of our structured approach with the archived MRI reports. RESULTS: A total of 859 IESFs were found in 671 of 3024 lumbar spine patients undergoing MRI (22%). A total of 623 out of them (73%) were categorized E2 (clinically unimportant finding), 192 (22%) were categorized E3 (likely unimportant finding), and 44 (5%) were categorized E4 (potentially important finding). A total of 347 of 859 findings were not mentioned in the archived reports for a nondetection rate of 40%. The nondetection rate for E4 category findings was 38.6% (17/44). CONCLUSION: IESFs on lumbar spine MRI are common with a significant nondetection rate of 40% using a nonstructured approach. Specifically, there was a significant nondetection rate of 38.6% for potentially important (E4) findings. LEVEL OF EVIDENCE: 3.

Coupled ATP and DNA binding of adeno-associated virus Rep40 helicase.

Adeno-associated virus 2 Rep40 helicase is involved in packaging single-stranded genomic DNA into virions. ATPase activity was stimulated 5-10-fold by DNA, depending upon assay conditions. The concentration dependence of Rep40 ATPase activity in the absence and presence of DNA indicates that the monomer is inactive and that the active enzyme is at least a dimer. Binding to oligonucleotides, examined by fluorescence anisotropy, was positively cooperative and required ATP or ATPgammaS; ADP and AMPPCP did not promote binding. The cooperativity and the nucleotide requirement were also demonstrated by surface plasmon resonance. Although the Rep40 behaves as a monomer in solution, it binds to DNA as an oligomer. The requirement of a nucleotide for DNA binding and the stimulation of ATPase activity by DNA indicate that the two processes are linked. Glutaraldehyde cross-linking generated a species that migrates as a trimer on sodium dodecyl sulfate (SDS) gel electrophoresis; ATPS promoted the formation of this species and higher order oligomers. The predominant cross-linked species was a trimer in the absence of ATPgammaS, regardless of whether duplex or single-stranded DNA was present. In the presence of duplex or single-stranded DNA and ATPgammaS, glutaraldehyde cross-linking generated a species that behaved as a dimer on SDS gel elctrophoresis. Sucrose-gradient velocity sedimentation of Rep40 gave an S20,w of 3 in the absence of ligands or in the presence of a 26 bp duplex DNA. The S20,w was 3.5 in the presence of ATPgammaS and 7 and 7.6 in the presence of DNA and ATPgammaS.