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.

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Altogether, our results indicate that both a peculiar dysbiosis of the gut microbiota and a significant decrease of butyrate production are present in patients with Behçet syndrome.

Purpose: Cannabinoids have been recently proposed as a new family of potential antitumor agents. The present study was undertaken to investigate the expression of the two cannabinoid receptors, CB 1 and CB 2 , in colorectal cancer and to provide new insight into the molecular pathways underlying the apoptotic activity induced by their activation. Experimental Design: Cannabinoid receptor expression was investigated in both human cancer specimens and in the DLD-1 and HT29 colon cancer cell lines. The effects of the CB 1 agonist arachinodyl-2'-chloroethylamide and the CB 2 agonist N-cyclopentyl-7-methyl-1-(2-morpholin-4-ylethyl)-1,8-naphthyridin-4(1H)-on-3-carboxamide (CB13) on tumor cell apoptosis and ceramide and tumor necrosis factor (TNF)-a production were evaluated. The knockdown of TNF-a mRNA was obtained with the use of selective small interfering RNA. Results: We show that the CB 1 receptor was mainly expressed in human normal colonic epithelium whereas tumor tissue was strongly positive for the CB 2 receptor. The activation of the CB 1 and, more efficiently, of the CB 2 receptors induced apoptosis and increased ceramide levels in the DLD-1 and HT29 cells. Apoptosis was prevented by the pharmacologic inhibition of ceramide de novo synthesis. The CB 2 agonist CB13 also reduced the growth of DLD-1 cells in a mouse model of colon cancer. The knockdown of TNF-a mRNA abrogated the ceramide increase and, therefore, the apoptotic effect induced by cannabinoid receptor activation.Conclusions: The present study shows that either CB 1 or CB 2 receptor activation induces apoptosis through ceramide de novo synthesis in colon cancer cells. Our data unveiled, for the first time, thatTNF-a acts as a link between cannabinoid receptor activation and ceramide production.

High-resolution melting analysis (HRMA) provides a valid approach to efficiently detect DNA genetic and somatic mutations. In this study, HRMA was used for the screening of 116 colorectal cancers (CRCs) to detect hot-spot mutations in the KRAS and BRAF oncogenes. Mutational hot spots on the PIK3CA gene, exons 9 and 20, were also screened. Direct sequencing was used to confirm and characterize HRMA results. HRMA revealed abnormal melting profiles in 65 CRCs (56.0%), 16 of them harboring mutations in 2 different genes simultaneously. The frequency of mutations was 17.2% for PIK3CA (11.2% in exon 9 and 6.0% in exon 20), 43.1% for KRAS exon 2, and 9.5% in exon 15 of the BRAF gene. We found a significant association between PIK3CA and KRAS mutations (P = .008), whereas KRAS and BRAF mutations were mutually exclusive (P = .001). This report describes a novel approach for the detection of PIK3CA somatic mutations by HRMA.

To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (r(s) = 0.31, P = 0.02 and r(s) = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis.

Purpose: Activity of histidine decarboxylase, the key enzyme in the synthesis of histamine, has been shown to be increased in several types of human tumors.We attempted to establish whether the possible involvement of histidine decarboxylase and histamine in colorectal carcinogenesis might be mediated by the activation of the cyclooxygenase-2 (COX-2) pathway. Experimental Design: Expression/activity of histidine decarboxylase, histamine content, and prostaglandin E 2 (PGE 2 ) production were analyzed in 33 colorectal cancer samples and in the HT29, Caco-2, and HCT116 colon cancer cell lines. The effects of histamine, celecoxib, and H 1 , H 2 , and H 4 receptor antagonists on COX-2 expression/activity, cell proliferation, and vascular endothelial growth factor (VEGF) production were assessed in the three colon cancer lines that showed different constitutive COX-2 expression. Results: We showed the up-regulation of histidine decarboxylase protein expression and activity in the tumor specimens when compared with normal colonic mucosa. Histidine decarboxylase activity and histamine content were also significantly higher in metastatic tumors than in nonmetastatic ones.These variables significantly correlated with tumor PGE 2 production.The administration of histamine increased COX-2 expression/activity, cell proliferation, and VEGF production in the COX-2-positive HT29 and Caco-2 cells. Treatment with either H 2 /H 4 receptor antagonists or celecoxib prevented these effects. Histamine had no effect on both the COX-2 pathway andVEGF production in the COX-2-negative HCT116 cells. Conclusions: Our data showed that histamine exerts both a proproliferative and a proangiogenic effect via H 2 /H 4 receptor activation. These effects are likely to be mediated by increasing COX-2-related PGE 2 production in COX-2-expressing colon cancer cells.

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