Low intraoperative end-tidal carbon dioxide levels are associated with improved recurrence-free survival after elective colorectal cancer surgery.

Study Objective: Higher levels of carbon dioxide (CO) increase the invasive abilities of colon cancer cells in vitro. Studies assessing target values for end-tidal CO concentrations (EtCO) to improve surgical outcome after colorectal cancer surgery are lacking. Therefore, we evaluated whether intraoperative EtCO was associated with differences in recurrence-free survival after elective colorectal cancer (CRC) surgery.

Inhibition of the Renin-Angiotensin System Improves Response to Neoadjuvant Therapy in Patients With Liver Metastasis of Colorectal Cancers.

Introduction: Renin-angiotensin-aldosterone system inhibitors (RAAS-I) have been shown to prolong overall survival in patients with liver metastasized colorectal cancer in combination with antiangiogenic treatment. The effects of RAAS-I combined with neoadjuvant chemotherapy on colorectal cancer liver metastasis remain unexplored. We aimed to study the response of patients undergoing liver resection to RAAS-I in combination with neoadjuvant therapy to elucidate their potential benefits.

The differences in drug disposition gene induction by rifampicin and rifabutin are unlikely due to different effects on important pregnane X receptor (NR1I2) splice variants.

Rifampicin and rifabutin can activate the pregnane X receptor (PXR, NR1I2), thereby inducing pharmacokinetically important genes/proteins and reducing exposure to co-administered drugs. Because induction effects vary considerably between these antibiotics, differences could be due to unequal rifamycin-induced activation or tissue expression of the three major NR1I2 splice variants, PXR.1 (NM_003889), PXR.

Outcomes of totally robotic Roux-en-Y gastric bypass in patients with BMI ≥ 50 kg/m: can the robot level out "traditional" risk factors?

Roux-en-Y gastric bypass (RYGB) in patients with body mass index (BMI) ≥ 50 kg/m is a challenging procedure and BMI ≥ 50 kg/m has been identified as independent risk factor for postoperative complications and increased morbidity in previous studies. The objective of the present study was to assess whether a BMI ≥ 50 kg/m and various established risk factors maintain their significance in patients undergoing fully robotic RYGB (rRYGB). A single-center analysis of prospectively collected data of 113 consecutive patients undergoing standardized rRYGB with robotic stapling technique and hand-sewn gastrojejunostomy using the daVinci Xi system.

Inhibition of pro-inflammatory signaling in human primary macrophages by enhancing arginase-2 via target site blockers.

The modulation of macrophage phenotype from a pro-inflammatory to an anti-inflammatory state holds therapeutic potential in the treatment of inflammatory disease. We have previously shown that arginase-2 (Arg2), a mitochondrial enzyme, is a key regulator of the macrophage anti-inflammatory response. Here, we investigate the therapeutic potential of Arg2 enhancement via target site blockers (TSBs) in human macrophages.

The HIF-prolyl hydroxylases have distinct and nonredundant roles in colitis-associated cancer.

Colitis-associated colorectal cancer (CAC) is a severe complication of inflammatory bowel disease (IBD). HIF-prolyl hydroxylases (PHD1, PHD2, and PHD3) control cellular adaptation to hypoxia and are considered promising therapeutic targets in IBD. However, their relevance in the pathogenesis of CAC remains elusive.

Prolyl Hydroxylase Inhibition Mitigates Allograft Injury During Liver Transplantation.

Background: Ischemia and reperfusion injury (IRI) determines primary allograft function after liver transplantation (LT). Primary graft dysfunction (PGD) is associated with increased morbidity and impaired graft survival and can eventually progress to graft failure requiring retransplantation. Hypoxia-inducible transcription factor-prolyl hydroxylase containing enzymes (PHD1, PHD2, and PHD3) are molecular oxygen sensors, which control the adaptive hypoxia response through the hypoxia-inducible factor (HIF).

Effect of Metformin on HIF-1α Signaling and Postoperative Adhesion Formation.

Background: Peritoneal adhesion formation is common after abdominal surgery and results in severe complications. Tissue hypoxia is one of the main drivers of peritoneal adhesions. Thus, we determined the clinical role of hypoxia-inducible factor (HIF)-1 signaling in peritoneal adhesions and investigated whether the biguanide antidiabetic drug metformin shows HIF-inhibitory effects and could be repurposed to prevent adhesion formation.

Carbon Dioxide Sensing by Immune Cells Occurs through Carbonic Anhydrase 2-Dependent Changes in Intracellular pH.

CO, the primary gaseous product of respiration, is a major physiologic gas, the biology of which is poorly understood. Elevated CO is a feature of the microenvironment in multiple inflammatory diseases that suppresses immune cell activity. However, little is known about the CO-sensing mechanisms and downstream pathways involved.

Inhibition of HIF-prolyl hydroxylases improves healing of intestinal anastomoses.

Anastomotic leakage (AL) accounts for a major part of in-house mortality in patients undergoing colorectal surgery. Local ischemia and abdominal sepsis are common risk factors contributing to AL and are characterized by upregulation of the hypoxia-inducible factor (HIF) pathway. The HIF pathway is critically regulated by HIF-prolyl hydroxylases (PHDs).

microRNA-155 Is Decreased During Atherosclerosis Regression and Is Increased in Urinary Extracellular Vesicles During Atherosclerosis Progression.

Background: Atherosclerosis is a chronic inflammatory disease driven by macrophage accumulation in medium and large sized arteries. Macrophage polarization and inflammation are governed by microRNAs (miR) that regulate the expression of inflammatory proteins and cholesterol trafficking. Previous transcriptomic analysis led us to hypothesize that miR-155-5p (miR-155) is regulated by conjugated linoleic acid (CLA), a pro-resolving mediator which induces regression of atherosclerosis .

Bevacizumab-based treatment as salvage therapy in patients with recurrent symptomatic brain metastases.

Background: Salvage treatment for recurrent brain metastases (BM) of solid cancers is challenging due to the high symptomatic burden and the limited local treatment options.

Methods: Patients with recurrent BM with no option for further local therapies were retrospectively identified from BM databases. Bevacizumab-based treatment was initiated as a salvage treatment.

Prognostic relevance of programmed death-ligand 1 expression and microsatellite status in small bowel adenocarcinoma.

Small bowel adenocarcinoma (SBA) is a dreadful disease. Patient prognosis is limited due to late presentation and ineffective chemotherapy. PD-1/PD-L1 checkpoint immunotherapy is regarded as a promising approach in several cancer entities.

Mucosal inflammation downregulates PHD1 expression promoting a barrier-protective HIF-1α response in ulcerative colitis patients.

The HIF hydroxylase enzymes (PHD1-3 and FIH) are cellular oxygen-sensors which confer hypoxic-sensitivity upon the hypoxia-inducible factors HIF-1α and HIF-2α. Microenvironmental hypoxia has a strong influence on the epithelial and immune cell function through HIF-dependent gene expression and consequently impacts upon the course of disease progression in ulcerative colitis (UC), with HIF-1α being protective while HIF-2α promotes disease. However, little is known about how inflammation regulates hypoxia-responsive pathways in UC patients.

Prolyl Hydroxylase Inhibition Mitigates Pouchitis.

Background: Pouchitis is the most common long-term complication after restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) or familial adenomatous polyposis (FAP), which can eventually progress to pouch failure, necessitating permanent stoma construction. Hypoxia-inducible transcription factor prolyl hydroxylase-containing enzymes (PHD1, PHD2, and PHD3) are molecular oxygen sensors that control adaptive gene expression through hypoxia-inducible factor (HIF). Emerging evidence supports PHDs as being therapeutic targets in intestinal inflammation.

Mechanisms and Consequences of Oxygen and Carbon Dioxide Sensing in Mammals.

Molecular oxygen (O) and carbon dioxide (CO) are the primary gaseous substrate and product of oxidative phosphorylation in respiring organisms, respectively. Variance in the levels of either of these gasses outside of the physiological range presents a serious threat to cell, tissue, and organism survival. Therefore, it is essential that endogenous levels are monitored and kept at appropriate concentrations to maintain a state of homeostasis.

Hypoxia-adaptive pathways: A pharmacological target in fibrotic disease?

Wound healing responses are physiological reactions to injuries and share common characteristics and phases independently of the injured organ or tissue. A major hallmark of wound healing responses is the formation of extra-cellular matrix (ECM), mainly consisting of collagen fibers, to restore the initial organ architecture and function. Overshooting wound healing responses result in unphysiological accumulation of ECM and collagen deposition, a process called fibrosis.

Protein Hydroxylation by Hypoxia-Inducible Factor (HIF) Hydroxylases: Unique or Ubiquitous?

All metazoans that utilize molecular oxygen (O) for metabolic purposes have the capacity to adapt to hypoxia, the condition that arises when O demand exceeds supply. This is mediated through activation of the hypoxia-inducible factor (HIF) pathway. At physiological oxygen levels (normoxia), HIF-prolyl hydroxylases (PHDs) hydroxylate proline residues on HIF-α subunits leading to their destabilization by promoting ubiquitination by the von-Hippel Lindau (VHL) ubiquitin ligase and subsequent proteasomal degradation.

High hepatic expression of PDK4 improves survival upon multimodal treatment of colorectal liver metastases.

Background: Patients with borderline resectable colorectal liver metastases (CRLM) frequently receive neoadjuvant chemotherapy (NC) to reduce tumour burden, thus making surgical resection feasible. Even though NC can induce severe liver injury, most studies investigating tissue-based prognostic markers focus on tumour tissue. Here, we assessed the prognostic significance of pyruvate-dehydrogenase-kinase isoenzyme 4 (PDK4) within liver tissue of patients undergoing surgical resection due to CRLM.

Pharmacologic inhibition of hypoxia-inducible factor (HIF)-hydroxylases ameliorates allergic contact dermatitis.

Background: When an immune cell migrates from the bloodstream to a site of chronic inflammation, it experiences a profound decrease in microenvironmental oxygen levels leading to a state of cellular hypoxia. The hypoxia-inducible factor-1α (HIF-1α) promotes an adaptive transcriptional response to hypoxia and as such is a major regulator of immune cell survival and function. HIF hydroxylases are the family of oxygen-sensing enzymes primarily responsible for conferring oxygen dependence upon the HIF pathway.

Loss of Prolyl-Hydroxylase 1 Protects against Biliary Fibrosis via Attenuated Activation of Hepatic Stellate Cells.

Liver fibrosis, eventually progressing to cirrhosis necessitating liver transplantation, poses a significant clinical problem. Oxygen shortage (hypoxia) and hypoxia-inducible transcription factors (HIFs) have been acknowledged as important drivers of liver fibrosis. The significance of oxygen-sensing HIF prolyl-hydroxylase (PHD) enzymes in this context has, however, remained elusive.

Prognostic indicators lose their value with repeated resection of colorectal liver metastases.

Background: The liver is the most common site of colorectal liver metastases (CRLM) and surgical resection improves overall survival in selected patients. Here, we investigate outcomes and relevant prognostic factors after repeated hepatic resections for CRLM.

Methods: From a prospective database, 578 patients who underwent 788 resections of colorectal liver metastases were included into this study.