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Background and Aims: Patients with inflammatory bowel disease have an increased risk of venous thromboembolism (VTE) and cardiovascular disease (CVD). The study aims to determine the prevalence of CVD and VTE risk factors in a large population of patients with ulcerative colitis (UC)., Methods: We conducted a cross-sectional study in 33 French and Belgium referral centers. A questionnaire was developed to explore self-reported risk factors for VTE and CVD, based on the latest international guidelines, in consecutive patients with UC., Results: A total of 1071 patients with UC were included. There were 539 women (50.3%), and the median age of patients was 44 years [32; 57]. The median disease duration was 10 years [6; 17]. In the cohort, 36.5% of patients reported no cardiovascular risk factor (CVRF) and 72% had ≤ 1 CVRF. Regarding cardiovascular risk markers (CVRM) 36.9% of patients reported no CVRM and 78% had ≤ 1 CVRM. Of the 1071 patients, 91.3% of patients reported no VTE strong risk factor and 96% had ≤ 1 VTE moderate risk factor., Conclusion: This is the first cohort specifically designed to assess both VTE and CVD risks in patients with UC. More than one third of patients with UC had no CVRF and around three quarters had ≤ 1 CVRF. In addition, more than nine out of ten patients had no VTE strong risk factor and ≤ 1 moderate risk factor. Physicians should be aware of these factors in their patients., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Single-port laparoscopic cholecystectomy is considered as a form of natural orifice surgery with better esthetic outcomes than traditional laparoscopic cholecystectomy. It is a technically demanding procedure, and no adequately powered trial has assessed the safety of this technique. Vascular injuries are less common than bile duct injuries during this procedure, but they can be rapidly fatal. The development of a right hepatic artery pseudoaneurysm is a rare but serious complication associated with single-port laparoscopic cholecystectomy. Two weeks following a single-port laparoscopic cholecystectomy for angiocholitis, a 40-year-old male patient presented with obstructive jaundice and persistent abdominal pain. The diagnosis of compressive hematoma due to a ruptured right hepatic artery pseudoaneurysm was confirmed by computed tomography scan and angiography. It was successfully treated by selective embolization of the right hepatic artery. In our experience, endovascular management was a noninvasive and effective treatment of ruptured pseudoaneurysms.

Background: Liver stiffness measurement (LSM) by transient elastography (TE) (FibroScan) is a validated method of quantifying liver fibrosis in non-transplanted patients with hepatitis C virus (HCV). It could be useful in follow-up after liver transplantation (LT). The aim of this study was to assess the diagnostic accuracy of LSM in evaluating liver fibrosis after LT in patients with and without recurrent HCV., Patients and Methods: Forty-three patients (mean age 57.6 ± 9.9 years), 28 (65.1%) HCV-positive patients and 15 (34.9%) HCV-negative patients underwent gold standard liver biopsy and TE 55.8 ± 4.9 months after transplantation. Liver fibrosis was scored on biopsy specimens according to METAVIR (F0-F4). Accuracy of TE and optimal stiffness cut-off values for fibrosis staging were determined by a receiver-operating characteristics (ROC) curve analysis., Results: Median stiffness values were significantly different for METAVIR score less than 2 (5.8 kPa) vs. METAVIR score greater to equal to 2 (9.6 kPa) (P<0.001). The area under the ROC curve was 0.83 for METAVIR score greater to equal to 2 (95%CI: 0.71-0.95). The optimal stiffness cut-off value was 7 kPa for METAVIR scores greater to equal to 2. The results were similar whether the patients had recurrent HCV infection or not., Conclusions: These results indicate that transient elastography accurately identifies LT recipients with significant fibrosis, irrespective of HCV status. It is a promising non-invasive tool to assess graft fibrosis progression after LT in patients with HCV recurrence, as well as for screening of late graft fibrosis of other etiologies. Transient elastography could reduce the use of invasive protocol biopsies., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Aims: Sulfide is released in the large intestine lumen by the microbiota and is an inhibitor of mitochondrial respiration and a genotoxic agent in colonocytes when present in excess. Deciphering how colonocytes metabolize sulfide is an important issue., Results: In this study, using the human colonic epithelial HT-29 Glc(-/+) cells, we found that 50 μM sodium hydrogen sulfide represents the threshold of concentration above which respiration is decreased. The capacity of HT-29 Glc(-/+) cells to oxidize lower concentration of sulfide was associated with the expression of transcripts corresponding to the enzymes of the sulfide oxidizing unit (SOU), that is, sulfide quinone reductase (SQR), dioxygenase ethylmalonic encephalopathy, and thiosulfate sulfur transferase (TST). Inhibition of cell O(2) consumption by sulfide was reverted by zinc but not by calcium and iron. When the cells undergo either spontaneous or butyrate-induced differentiation, their capacity to oxidize sulfide was significantly increased. The expression levels of the genes corresponding to the enzymes of the SOU were not increased, whereas increased cellular maximal respiratory capacity and oxygen consumption by the dioxygenase were both measured. In human biopsies recovered from various parts of the large intestine, the three enzymes of the SOU were expressed., Innovation: SOU and cell respiratory capacity are crucial for sulfide detoxification in colonocytes., Conclusion: Sulfide oxidative capacity in the colonic mucosa is higher in differentiated than in proliferative epithelial cells. The cell respiratory capacity and SOU activity appear to represent major determinants allowing sulfide detoxification in colonic epithelial cells.

Hydrogen sulfide (H(2)S) is present in the lumen of the human large intestine at millimolar concentrations. However, the concentration of free (unbound) sulfide is in the micromolar range due to a large capacity of fecal components to bind the sulfide. H(2)S can be produced by the intestinal microbiota from alimentary and endogenous sulfur-containing compounds including amino acids. At excessive concentration, H(2)S is known to severely inhibit cytochrome c oxidase, the terminal oxidase of the mitochondrial electron transport chain, and thus mitochondrial oxygen (O(2)) consumption. However, the concept that sulfide is simply a metabolic troublemaker toward colonic epithelial cells has been challenged by the discovery that micromolar concentration of H(2)S is able to increase the cell respiration and to energize mitochondria allowing these cells to detoxify and to recover energy from luminal sulfide. The main product of H(2)S metabolism by the colonic mucosa is thiosulfate. The enzymatic activities involved in sulfide oxidation by the colonic epithelial cells appear to be sulfide quinone oxidoreductase considered as the first and rate-limiting step followed presumably by the action of sulfur dioxygenase and rhodanese. From clinical studies with human volunteers and experimental works with rodents, it appears that H(2)S can exert mostly pro- but also anti-inflammatory effects on the colonic mucosa. From the available data, it is tempting to propose that imbalance between the luminal concentration of free sulfide and the capacity of colonic epithelial cells to metabolize this compound will result in an impairment of the colonic epithelial cell O(2) consumption with consequences on the process of mucosal inflammation. In addition, endogenously produced sulfide is emerging as a prosecretory neuromodulator and as a relaxant agent toward the intestinal contractibility. Lastly, sulfide has been recently described as an agent involved in nociception in the large intestine although, depending on the experimental design, both pro- and anti-nociceptive effects have been reported.

Poly(ADP-ribose) polymerase (PARP) is an abundant, chromatin-associated, NAD-dependent enzyme that functions in multiple chromosomal processes, including DNA replication and chromatin remodeling. The Epstein-Barr virus (EBV) origin of plasmid replication (OriP) is a dynamic genetic element that confers stable episome maintenance, DNA replication initiation, and chromatin organization functions. OriP function depends on the EBV-encoded origin binding protein EBNA1. We have previously shown that EBNA1 is subject to negative regulation by poly(ADP-ribosyl)ation (PARylation). We now show that PARP1 physically associates with OriP in latently EBV-infected B cells. Short hairpin RNA depletion of PARP1 enhances OriP replication activity and increases EBNA1, origin recognition complex 2 (ORC2), and minichromosome maintenance complex (MCM) association with OriP. Pharmacological inhibitors of PARP1 enhance OriP plasmid maintenance and increase EBNA1, ORC2, and MCM3 occupancy at OriP. PARylation in vitro inhibits ORC2 recruitment and remodels telomere repeat factor (TRF) binding at the dyad symmetry (DS) element of OriP. Purified PARP1 can ribosylate EBNA1 at multiple sites throughout its amino terminus but not in the carboxy-terminal DNA binding domain. We also show that EBNA1 linking regions (LR1 and LR2) can bind directly to oligomers of PAR. We propose that PARP1-dependent PARylation of EBNA1 and adjacently bound TRF2 induces structural changes at the DS element that reduce EBNA1 DNA binding affinity and functional recruitment of ORC.

In higher eukaryotes, the origin recognition complex (ORC) lacks sequence-specific DNA binding, and it remains unclear what other factors specify an origin of DNA replication. The Epstein-Barr virus origin of plasmid replication (OriP) recruits ORC, but the precise mechanism of ORC recruitment and origin activation is not clear. We now show that ORC is recruited selectively to the dyad symmetry (DS) region of OriP as a consequence of direct interactions with telomere repeat factor 2 (TRF2) and ORC1. TRF-binding sites within DS stimulate replication initiation and facilitate ORC recruitment in vitro and in vivo. TRF2, but not TRF1 or hRap1, recruits ORC from nuclear extracts. The amino-terminal domain of TRF2 associated with a specific region of ORC1 and was necessary for stimulation of DNA replication. These results support a model in which TRF2 stimulates OriP replication activity by direct binding with ORC subunits.

Tankyrase (TNKS) is a telomere-associated poly-ADP ribose polymerase (PARP) that has been implicated along with several telomere repeat binding factors in the regulation of Epstein-Barr virus origin of plasmid replication (OriP). We now show that TNKS1 can bind to the family of repeats (FR) and dyad symmetry regions of OriP by using a chromatin immunoprecipitation assay and DNA affinity purification. TNKS1 and TNKS2 bound to EBNA1 in coimmunoprecipitation experiments with transfected cell lysates and with purified recombinant proteins in vitro. Two RXXPDG-like TNKS-interacting motifs in the EBNA1 amino-terminal domain mediated binding with the ankyrin repeat domain of TNKS. Mutations of both motifs at EBNA1 G81 and G425 abrogated TNKS binding and enhanced EBNA1-dependent replication of OriP. Small hairpin RNA targeted knock-down of TNKS1 enhanced OriP-dependent DNA replication. Overexpression of TNKS1 or TNKS2 inhibited OriP-dependent DNA replication, while a PARP-inactive form of TNKS2 (M1045V) was compromised for this inhibition. We show that EBNA1 is subject to PAR modification in vivo and to TNKS1-mediated PAR modification in vitro. These results indicate that TNKS proteins can interact directly with the EBNA1 protein, associate with the FR region of OriP in vivo, and inhibit OriP replication in a PARP-dependent manner.

DNA affinity purification has been used to identify cellular and viral proteins associated with the Epstein-Barr virus origin of plasmid DNA replication. This approach allows for a one- or two-step purification scheme of high-affinity DNA binding proteins from crude nuclear extracts. Additionally, this approach may be useful for isolation of proteins that are found in the insoluble fractions of the nuclear matrix or scaffold.

Epstein-Barr virus OriP confers cell cycle-dependent DNA replication and stable maintenance on plasmids in EBNA1-positive cells. The dyad symmetry region of OriP contains four EBNA1 binding sites that are punctuated by 9-bp repeats referred to as nonamers. Previous work has shown that the nonamers bind to cellular factors associated with human telomeres and contribute to episomal maintenance of OriP. In this work, we show that substitution mutation of all three nonamer sites reduces both DNA replication and plasmid maintenance of OriP-containing plasmids by 2.5- to 5-fold. The nonamers were required for high-affinity binding of TRF1, TRF2, and hRap1 to the dyad symmetry element but were not essential for the binding of EBNA1 as determined by DNA affinity purification from nuclear extracts. Chromatin immunoprecipitation assays indicated that TRF1, TRF2, and hRap1 bound OriP in vivo. Cell cycle studies indicate that TRF2 binding to OriP peaks in G(1)/S while TRF1 binding peaks in G(2)/M. OriP replication was inhibited by transfection of full-length TRF1 but not by deletion mutants lacking the myb DNA binding domain. In contrast, OriP replication was not affected by transfection of full-length TRF2 or hRap1 but was potently inhibited by dominant-negative TRF2 or hRap1 amino-terminal truncation mutants. Knockdown experiments with short interfering RNAs (siRNAs) directed against TRF2 and hRap1 severely reduced OriP replication, while TRF1 siRNA had a modest stimulatory effect on OriP replication. These results indicate that TRF2 and hRap1 promote, while TRF1 antagonizes, OriP-dependent DNA replication and suggest that these telomeric factors contribute to the establishment of replication competence at OriP.

The authors present a case of Kikuchi's disease associated with systemic lupus erythematosus (SLE) and autoimmune-like hepatitis. Kikuchi's disease, or histiocytic necrotizing lymphadenitis is occasionally associated with SLE and mildly elevated aminotransferases. A 17-year old woman presented with fever, arthritis and bilateral cervical adenopathy. Histopathological and immunohistochemical examinations of an excised lymph node showed evidence of Kikuchi disease. An elevation of hepatocytic enzymes (aminotransferases and gamma-glutamyl transpeptidase) associated with smooth muscle antibodies in a titer of 1/320 was present. Clinical symptoms and laboratory tests improved after "pulse" corticotherapy. The association described has not been described in the literature, but is considered possible due to the immune pathogenicity of the 3 simultaneous diseases. Kikuchi-Fujimoto's disease, or histiocytic necrotizing lymphadenitis (HNL), is a rare condition first described in 1972 independently by Kikuchi and Fujimoto. HNL is rarely associated with systemic lupus erythematosus (SLE). It is a benign illness characterized by fever and cervical adenopathy and has a self-limiting course.

Carcinoid tumours are enigmatic, slow growing malignancies, which occur most frequently (74%) in the gastrointestinal tract. Symptoms of the carcinoid syndrome (flushing and diarrhoea) are infrequent, occurring in approximately 10% of the patients with small bowel carcinoid. A 45-year-old patient with multiple liver metastases, diagnosed in 1994 with nonHodgkin's lymphoma after undergoing surgery for a distal ileal tumour, was referred to us by the Department of Haematology. At that moment the issue of a differential diagnosis with a carcinoid tumour arose, due to the long evolution and lack of evidence to support the initial diagnosis. The carcinoid syndrome was in fact present (the patient experiencing flush after small amounts of alcohol and emotions) and also we identified elevated values of 5HIAA. Reevaluation of the histologic sections of the ileal tumour as well as an ultrasound guided fine needle aspiration of an intrahepatic lesion confirmed the diagnosis of "carcinoid tumour". This conclusion lead to new therapeutic options for this patient. One of the main therapeutic options used in treating multiple liver metastases from a carcinoid tumour is chemoembolization and this case offered an excellent opportunity to present this therapy.

Ocr, the product of gene 0.3 of bacteriophage T7, prevents the action of restriction endonucleases of the host bacteria. The amino-acid sequence of ocr has less than 20% similarity to any protein of known three-dimensional structure. Ocr has been crystallized in a number of different crystal forms and X-ray data for the seleno-L-methionine-substituted form has been collected to a resolution of 1.8 A. The presence of caesium was found to be required for good crystal growth. Anomalous X-ray data was used to identify possible positions for Se and Cs atoms in the unit cell.