18F-fluorocholine PET/CT detects parathyroid gland hyperplasia as well as adenoma: 401 PET/CTs in one center.

BACKGROUND: During the past decade, 18F-fluorocholine (FCH) PET/CT has been continuously performed at Tenon Hospital (Paris, France) for the detection of hyperfunctioning parathyroid glands (PT). METHODS: A cohort of 401 patients, deliberately referred for HPT since September 2012, has been analyzed. The aim of this real-life retrospective study was to determine the diagnostic utility of FCH in this setting, overall and in subgroups according to the type of hyperparathyroidism (HPT), the context of FCH in the imaging work-up and in the patient's history: initial imaging or persistence or recurrence after previous parathyroidectomy (PTX). The influence of the histologic type of resected PTs, hyperplasia or adenoma, on the preoperatory detection on FCH PET/CT has been studied as well. RESULTS: Four hundred one FCH PET/CTs were included in the cohort, performed in 323 patients with primary HPT (pHPT), including 18 with familial HPT (fHPT), and in 78 patients with secondary renal HPT (rHPT). The overall positivity rate in the 401 FCH PET/CTs was 73%. The PTX rate was twice greater in patients whose FCH PET/CT was positive than negative (73% vs. 35%). Abnormal PT(s) were pathology proven in 214 patients: only hyperplastic gland(s) in 75 cases and at least one adenoma in 136 cases; FCH PET/CT sensitivity was 89% and 92%, respectively. Similarly, there was no significant difference in patient-based sensitivity whether FCH PET/CT was performed as 1st line or later in the imaging work-up, or indicated for initial imaging or for suspicion of persistent or recurrent HPT. Gland-based sensitivity was significantly lower for hyperplasia than for adenoma (72% and 86%, respectively). The lowest gland-based sensitivity value was 65%, observed in case of hyperplasia and when FCH was performed late in the imaging work-up. FCH PET/CT correctly showed multiglandular HPT (MGD) in 36/61 proven cases, 59%. Results of ultrasonography (US) and 99mTc-sestaMIBI (MIBI) imaging were available in 346 and 178 patients, respectively. For both modalities, the corresponding sensitivity values were significantly less than those of FCH PET/CT (e.g., overall gland-based sensitivity 78% for FCH, 45% for US, 30% for MIBI) and MGD was detected in 32% of cases by US and 15% by MIBI. CONCLUSIONS: Although FCH PET/CT has been performed since 2017 as 1st line imaging for HPT at Tenon Hospital (Paris, France), a large majority of patients underwent prior US and/or MIBI in their preoperative work-up. Therefore, a selection bias is very likely, as most patients referred to FCH PET/CT had non-conclusive or discordant results of US and MIBI, explaining the low performance of those modalities in the present cohort compared to published results. Nevertheless, the superiority of FCH PET/CT over US and MIBI in detecting abnormal PTs reported in various comparative studies is definitely confirmed in this larger real-life cohort. The detection with FCH PET/CT of hyperplastic PTs was somewhat lower than that of adenomas but was better than using US or MIBI. The present results lead to recommend FCH PET/CT as the first line imaging modality in HPT when it is widely available or, if less available, at least in HPT with predominance of hyperplasia and/or MGD.

Systemic Jak1 activation provokes hepatic inflammation and imbalanced FGF23 production and cleavage.

Fibroblast growth factor 23 (FGF23) is a main regulator of mineral homeostasis. Low and high circulating FGF23 levels are associated with bone, renal, cardiovascular diseases, and increased mortality. Understanding the factors and signaling pathways affecting FGF23 levels is crucial for the management of these diseases and their complications. Here, we show that activation of the Jak1/Stat3 signaling pathway leads to inflammation in liver and to an increase in hepatic FGF23 synthesis, a key hormone in mineral metabolism. This increased synthesis leads to massive C-terminal FGF23 circulating levels, the inactive C-terminal fragment, and increased intact FGF23 levels, the active form, resulting in imbalanced production and cleavage. Liver inflammation does not lead to activation of the calcineurin-NFAT pathway, and no signs of systemic inflammation could be observed. Despite the increase of active intact FGF23, excessive C-terminal FGF23 levels block the phosphaturic activity of FGF23. Therefore, kidney function and renal αKlotho expression are normal and no activation of the MAPK pathway was detected. In addition, activation of the Jak1/Stat3 signaling pathway leads to high calcitriol levels and low parathyroid hormone production. Thus, JAK1 is a central regulator of mineral homeostasis. Moreover, this study also shows that in order to assess the impact of high FGF23 levels on disease and kidney function, the source and the balance in FGF23 production and cleavage are critical.

Genotype-phenotype associations of polymorphisms within the gene locus of NOD-like receptor pyrin domain containing 3 in Swiss inflammatory bowel disease patients.

BACKGROUND: Genetic variations within the regulatory region of the gene encoding NOD-like receptor pyrin domain containing 3 (NLRP3) have been associated with Crohn's Disease (CD). NLRP3 is part of the NLRP3-inflammasome that mediates the maturation of IL-1ß and IL-18. Carrying the major allele of the single nucleotide polymorphisms (SNPs) rs10733113, rs4353135 and rs55646866 is associated with an increased risk for CD. We here studied the impact of these polymorphisms on clinical characteristics in patients of the Swiss IBD Cohort Study (SIBDCS). METHODS: We included 981 Crohn's disease (CD) patients and 690 ulcerative colitis (UC) patients of the SIBDCS. We analyzed whether three CD-associated NLRP3 polymorphisms have an impact on the clinical disease course in these patients. RESULTS: In CD patients presence of the major allele (G) of rs10733113 was associated with less surgeries and lower maximal CDAI and a similar trend was observed for rs55646866 and rs4353135. Presence of the major allele of all three SNPs was negatively correlated to maximal CDAI. In UC patients homozygous genotype for the major allele (CC) for rs55646866 was associated with a higher age at diagnosis and a higher MTWAI index. Homozygous genotype for the major allele of all three polymorphisms was associated with a higher number of ambulatory visits and longer hospital stays. CONCLUSIONS: In CD patients presence of the major allele of all three polymorphisms was associated with markers of a less severe disease course, while in UC the homozygous genotype for all major alleles suggested a more severe disease activity.

Elevated oxysterol levels in human and mouse livers reflect nonalcoholic steatohepatitis.

Nonalcoholic steatohepatitis (NASH), a primary cause of liver disease, leads to complications such as fibrosis, cirrhosis, and carcinoma, but the pathophysiology of NASH is incompletely understood. Epstein-Barr virus-induced G protein-coupled receptor 2 (EBI2) and its oxysterol ligand 7α,25-dihydroxycholesterol (7α,25-diHC) are recently discovered immune regulators. Several lines of evidence suggest a role of oxysterols in NASH pathogenesis, but rigorous testing has not been performed. We measured oxysterol levels in the livers of NASH patients by LC-MS and tested the role of the EBI2-7α,25-diHC system in a murine feeding model of NASH. Free oxysterol profiling in livers from NASH patients revealed a pronounced increase in 24- and 7-hydroxylated oxysterols in NASH compared with controls. Levels of 24- and 7-hydroxylated oxysterols correlated with histological NASH activity. Histological analysis of murine liver samples demonstrated ballooning and liver inflammation. No significant genotype-related differences were observed in Ebi2-/- mice and mice with defects in the 7α,25-diHC synthesizing enzymes CH25H and CYP7B1 compared with wild-type littermate controls, arguing against an essential role of these genes in NASH pathogenesis. Elevated 24- and 7-hydroxylated oxysterol levels were confirmed in murine NASH liver samples. Our results suggest increased bile acid synthesis in NASH samples, as judged by the enhanced level of 7α-hydroxycholest-4-en-3-one and impaired 24S-hydroxycholesterol metabolism as characteristic biochemical changes in livers affected by NASH.

Tumor necrosis factor stimulates fibroblast growth factor 23 levels in chronic kidney disease and non-renal inflammation.

Fibroblast growth factor 23 (FGF23) regulates phosphate homeostasis, and its early rise in patients with chronic kidney disease is independently associated with all-cause mortality. Since inflammation is characteristic of chronic kidney disease and associates with increased plasma FGF23 we examined whether inflammation directly stimulates FGF23. In a population-based cohort, plasma tumor necrosis factor (TNF) was the only inflammatory cytokine that independently and positively correlated with plasma FGF23. Mouse models of chronic kidney disease showed signs of renal inflammation, renal FGF23 expression and elevated systemic FGF23 levels. Renal FGF23 expression coincided with expression of the orphan nuclear receptor Nurr1 regulating FGF23 in other organs. Antibody-mediated neutralization of TNF normalized plasma FGF23 and suppressed ectopic renal Fgf23 expression. Conversely, TNF administration to control mice increased plasma FGF23 without altering plasma phosphate. Moreover, in Il10-deficient mice with inflammatory bowel disease and normal kidney function, plasma FGF23 was elevated and normalized upon TNF neutralization. Thus, the inflammatory cytokine TNF contributes to elevated systemic FGF23 levels and also triggers ectopic renal Fgf23 expression in animal models of chronic kidney disease.

Titanium dioxide nanoparticles exacerbate DSS-induced colitis: role of the NLRP3 inflammasome.

OBJECTIVE: Western lifestyle and diet are major environmental factors playing a role in the development of IBD. Titanium dioxide (TiO2) nanoparticles are widely used as food additives or in pharmaceutical formulations and are consumed by millions of people on a daily basis. We investigated the effects of TiO2 in the development of colitis and the role of the nucleotide-binding oligomerisation domain receptor, pyrin domain containing (NLRP)3 inflammasome. DESIGN: Wild-type and NLRP3-deficient mice with dextran sodium sulfate-induced colitis were orally administered with TiO2 nanoparticles. The proinflammatory effects of TiO2 particles in cultured human intestinal epithelial cells (IECs) and macrophages were also studied, as well as the ability of TiO2 crystals to traverse IEC monolayers and accumulate in the blood of patients with IBD using inductively coupled plasma mass spectrometry. RESULTS: Oral administration of TiO2 nanoparticles worsened acute colitis through a mechanism involving the NLRP3 inflammasome. Importantly, crystals were found to accumulate in spleen of TiO2-administered mice. In vitro, TiO2 particles were taken up by IECs and macrophages and triggered NLRP3-ASC-caspase-1 assembly, caspase-1 cleavage and the release of NLRP3-associated interleukin (IL)-1ß and IL-18. TiO2 also induced reactive oxygen species generation and increased epithelial permeability in IEC monolayers. Increased levels of titanium were found in blood of patients with UC having active disease. CONCLUSION: These findings indicate that individuals with a defective intestinal barrier function and pre-existing inflammatory condition, such as IBD, might be negatively impacted by the use of TiO2 nanoparticles.

Deficiency of Protein Tyrosine Phosphatase Non-Receptor Type 2 in Intestinal Epithelial Cells Has No Appreciable Impact on Dextran Sulphate Sodium Colitis Severity But Promotes Wound Healing.

BACKGROUND/AIMS: The protein tyrosine phosphatase non-receptor type 2 (PTPN2) is known to mediate susceptibility to inflammatory bowel diseases. Cell culture experiments suggest that PTPN2 influences barrier function, autophagy and secretion of pro-inflammatory cytokines. PTPN2 knockout mice die a few weeks after birth due to systemic inflammation, emphasizing the importance of this phosphatase in inflammatory processes. The aim of this study was to investigate the role of PTPN2 in colon epithelial cells by performing dextran sulphate sodium (DSS)-induced colitis in PTPN2xVilCre mice. METHODS: Acute colitis was induced by administering 2.5 or 2% DSS for 7 days and chronic colitis by 4 cycles of treatment using 1% DSS. Body weight of mice was measured regularly and colonoscopy was done at the end of the experiments. Mice were sacrificed afterwards and colon specimens were obtained for H&E staining. For analysis of wound healing, mechanical wounds were introduced during endoscopy and wound closure assessed by daily colonoscopy. RESULTS: Although colonoscopy and weight development suggested changes in colitis severity, the lack of any influence of PTPN2 deficiency on histological scoring for inflammation severity after acute or chronic DSS colitis indicates that colitis severity is not influenced by epithelial-specific loss of PTPN2. Chronic colitis induced the development of aberrant crypt foci more frequently in PTPN2xVilCre mice compared to their wild type littermates. On the other hand, loss of PTPN2-induced enhanced epithelial cell proliferation and promoted wound closure. CONCLUSIONS: Loss of PTPN2 in intestinal epithelial cells (IECs) has no significant influence on inflammation in DSS colitis. Obviously, loss of PTPN2 in IECs can be compensated in vivo, thereby suppressing a phenotype. This lack of a colitis-phenotype might be due to enhanced epithelial cell proliferation and subsequent increased wound-healing capacity of the epithelial layer.

Oral administration of dextran sodium sulphate induces a caecum-localized colitis in rabbits.

Trichuris suis ova (TSO) have shown promising results in the treatment of inflammatory bowel disease (IBD) but the mechanisms which underlies this therapeutic effect cannot be studied in mice and rats as T. suis fails to colonize the rodent intestine, whilst hatching in humans and rabbits. As a suitable rabbit IBD model is currently not available, we developed a rabbit colitis model by administration of dextran sodium sulphate (DSS). White Himalayan rabbits (n = 12) received 0.1% DSS in the daily water supply for five days. Clinical symptoms were monitored daily, and rabbits were sacrificed at different time points. A genomewide expression analysis was performed with RNA isolated from caecal lamina propria mononuclear cells (LPMC) and intestinal epithelial cells (IEC). The disease activity index of DSS rabbits increased up to 2.1 ± 0.4 (n = 6) at day 10 (controls <0.5). DSS induced a caecum-localized pathology with crypt architectural distortion, stunted villous surface and inflammatory infiltrate in the lamina propria. The histopathology score reached a peak of 14.2 ± 4.9 (n = 4) at day 10 (controls 7.7 ± 0.9, n = 5). Expression profiling revealed an enrichment of IBD-related genes in both LPMC and IEC. Innate inflammatory response, Th17 signalling and chemotaxis were among the pathways affected significantly. We describe a reproducible and reliable rabbit model of DSS colitis. Localization of the inflammation in the caecum and its similarities to IBD make this model particularly suitable to study TSO therapy in vivo.

"Reinnervated Serratus free flap, for a functional outcome in tongue reconstruction: a surgical technique video".

The current benchmark for tongue reconstruction following the excision of locally advanced tumors involves the utilization of free skin or fasciocutaneous flaps, such as anterolateral thigh flap or forearm free flap. They facilitate the volumetric reconstruction of the tongue, leveraging passive mobility from the remaining native tongue tissue. The challenge in tongue reconstruction surgery persists in achieving functional restoration through adequate volume and optimized mobility, using tissue that is both adapted and comparable to native tissue. While the free serratus muscle flap has been described for various indications, its application in tongue reconstructions remains underexploited. Specifically, in cases of locally advanced tumors affecting the mobile tongue, typically within the junctional area and without extension to the floor of the mouth nor to the tip of the tongue, the serratus free flap has shown great results. Reinnervation of the flap is achieved connecting the thoracodorsal nerve to the descending branch of the XII nerve. This technique facilitates functional tongue reconstruction, promoting rapid mucosal epithelialization and reinnervation, which, in turn, preserves muscle volume and sustains adequate trophicity without fibrosis. Regarding these considerations, the pure muscle serratus free flap emerges as a valuable and effective alternative in tongue reconstruction. Notably, there is a dearth of step-by-step operative technique descriptions for this indication in the existing literature. We present a video demonstrating the surgical technique, showcasing procedures as performed at Tenon Hospital (Paris, France).

Comparison of normocalcemic versus hypercalcemic primary hyperparathyroidism in a hypercalciuric renal stone population.

CONTEXT: Primary hyperparathyroidism (PHPT) is commonly diagnosed in the setting of hypercalcemia, whereas normocalcemic primary hyperparathyroidism (NHPT) may be misdiagnosed. OBJECTIVE: Our objective was to compare hypercalcemic hyperparathyroidism (HPHPT) versus NHPT hypercalciuric renal stone patients. DESIGN AND SETTING: We took advantage of a routine calcium load test performed in hypercalciuric renal stone patients to assess retrospectively among PHPT patients, prevalence and characteristics of NHPT and HPHPT under a calcium restricted diet. RESULTS: Among 1671 hypercalciuric patients included, 91 patients have a final diagnosis of PHPT(post load ionized calcium (iCa)>1.31 mmol/L and PTH>30 pg/ml). Prevalence of NHPT is 40% of all PHPT, however according to total serum calcium 4/35 NHPT and 7/56 HPHPT would have been misclassified in the other group. 18/35 NHPT and 40/56 HPHPT underwent parathyroidectomy. No significant characteristics related to parathyroid weight, stone composition or bone remodeling biomarkers is detected between groups. Whereas iCa is higher in HPHPT in fasting state and after calcium load, we found no difference for calcium diet, 24-hour calciuria, or calcitriol. Of notice, renal calcium excretion (FECa) post load increases by 303% in NHPT but only 176% in HPHPT (p=0.01) likely explained by a lesser PTH decrease (p=0.02). However, a strong negative association (p<0.0001) detected between pooled pre and post load iCa and PTH only in NHPT group suggests a persistent efficient PTH-CaSR control within parathyroid glands in this group. CONCLUSION: Our data show the relevance of dynamic tests to unmask NHPT in hypercalciuric renal stone patients.

Differential cystine and dibasic amino acid handling after loss of function of the amino acid transporter b0,+AT (Slc7a9) in mice.

Cystinuria is an autosomal recessive disease caused by mutations in SLC3A1 (rBAT) and SLC7A9 (b(0,+)AT). Gene targeting of the catalytic subunit (Slc7a9) in mice leads to excessive excretion of cystine, lysine, arginine, and ornithine. Here, we studied this non-type I cystinuria mouse model using gene expression analysis, Western blotting, clearance, and brush-border membrane vesicle (BBMV) uptake experiments to further characterize the renal and intestinal consequences of losing Slc7a9 function. The electrogenic and BBMV flux studies in the intestine suggested that arginine and ornithine are transported via other routes apart from system b(0,+). No remarkable gene expression changes were observed in other amino acid transporters and the peptide transporters in the intestine and kidney. Furthermore, the glomerular filtration rate (GFR) was reduced by 30% in knockout animals compared with wild-type animals. The fractional excretion of arginine was increased as expected (∼100%), but fractional excretions of lysine (∼35%), ornithine (∼16%), and cystine (∼11%) were less affected. Loss of function of b(0,+)AT reduced transport of cystine and arginine in renal BBMVs and completely abolished the exchanger activity of dibasic amino acids with neutral amino acids. In conclusion, loss of Slc7a9 function decreases the GFR and increases the excretion of several amino acids to a lesser extent than expected with no clear regulation at the mRNA and protein level of alternative transporters and no increased renal epithelial uptake. These observations indicate that transporters located in distal segments of the kidney and/or metabolic pathways may partially compensate for Slc7a9 loss of function.

Early detection of hypocalcemia after total/completion thyroidectomy: routinely usable algorithm based on serum calcium level.

BACKGROUND: The purpose of this prospective bicentric study was to investigate the course of serum calcium (Ca) and phosphorus (Phph) after total/completion thyroidectomy to establish a reliable and cost-effective strategic algorithm to detect patients at risk for postoperative hypocalcemia. METHODS: This observational study included 136 patients. Serum Ca and Phph levels were preoperatively and postoperatively recorded 6, 12, 20, and 48 h (H) after skin closure. Criteria for hypocalcemia were postoperative Ca levels ≤1.9 mmol/L at any time point and/or patients experiencing symptoms of hypocalcemia. Postoperative Ca supplementation was never given before H20 assay. Ca levels and their differences between time points were compared. RESULTS: Twenty-four percent of patients experienced hypocalcemia. At H12 and H20, the rates of patients with Ca levels ≤1.9 mmol/L were similar and larger than at H6 (p < 0.001). The H20-preoperative difference had the best area under the ROC curves (value = 0.87), and a difference ≤-0.3 was significantly more frequent in case of hypocalcemia (p = 0.001). The H20 assay and the difference H20-preop were consequently selected to design a new algorithm for hypocalcemia detection. Adding H48 assay in some specific cases (12.5 % of all included patients) enabled 100 % detection. Phosphorus assays were not informative in detecting hypocalcemia. CONCLUSIONS: This new algorithm enables, with 100 % sensitivity and 88.4 % specificity, early detection of severe hypocalcemia after total/completion thyroidectomy. It may become a useful and cost-effective tool for safe and early patient discharge, especially if PTH assays cannot be routinely used because of their availability or cost.

Sphingomyelin induces cathepsin D-mediated apoptosis in intestinal epithelial cells and increases inflammation in DSS colitis.

BACKGROUND: The sphingolipid sphingomyelin is a constituent in food derived from animals. Digestive breakdown of sphingomyelin results in ceramide, recently suggested to be involved in activation of cathepsin D as a novel mediator of apoptosis. Damage of the epithelial barrier was detected in patients with inflammatory bowel disease (IBD) due to increased rates of intestinal epithelial cell (IEC) apoptosis. METHODS: Acute colitis was induced in C57-BL/6 mice with 2.0% dextran sulfate sodium (DSS) over 7 days. Spontaneous colitis was developed in B6-IL10tm1Cgn (interleukin 10-negative (IL-10(-/-))) mice. Mice received 4 or 8 mg sphingomyelin/day by oral gavage. IECs were isolated ex vivo. Apoptosis was determined by propidium iodide (PI) and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining. Execution of apoptosis was confirmed by analysis of active cathepsin D, caspase-3 and caspase-9 with western blot and immunohistochemistry (IHC). RESULTS: Following DSS-mediated colitis, fluorescence-activated cell sorting (FACS) analysis indicated increased apoptosis of IECs under dietary sphingomyelin. The mean sub-G(1) portion increased from 8.7±2.5% under a normal diet to 14.0±3.1% under dietary sphingomyelin. Cathepsin activity was significantly increased in isolated IECs after gavage of 4 mg of sphingomyelin per day. Western blot and IHC revealed execution of the apoptotic cascade via activated caspase-3 and caspase-9. Dietary sphingomyelin in the IL-10(-/-) model confirmed aggravation of mucosal inflammation. CONCLUSION: Apoptosis of IEC induced by dietary sphingomyelin is mediated via ceramide and cathepsin D activation. This shortens the physiological life cycle of IECs and impairs crucial functions of the intestinal mucosa: barrier, defence and nutrient absorption. The findings provide evidence that dietary sphingomyelin may increase intestinal inflammation.

Beyond Surgical Treatment in Adenoid Cystic Carcinoma of the Head and Neck: A Literature Review.

Introduction: Adenoid cystic carcinoma (AdCC) is a rare tumour as it accounts for about 10% of all salivary gland neoplasms. It occurs in all age groups with a predominance of women, but no risk factors have been identified to date. Although AdCC behaves as a slow-growing tumour, it is characterized by multiple and late recurrences. Therefore, we aim to update the knowledge of the treatment options in advanced and recurrent cases. Materials and Methods: We performed a systematic literature review to provide a synthesis of the practical knowledge required for AdCC non-surgical management. Altogether, 99 out of the 1208 available publications were selected for analysis. Results: AdCC is described as a basaloid tumour consisting of epithelial and myoepithelial cells. Immunohistochemistry is useful for diagnosis (PS100, Vimentin, CD117, CKit, muscle actin, p63) and for prognosis (Ki67). Identified mutations could lead to therapeutic opportunities (MYB-NFIB, Notch 1). The work-up is mainly based on neck and chest CT scan and MRI, and PET-CT with 18-FDG or PSMA can be considered. Surgical treatment remains the gold standard in resectable cases. Post-operative intensity modulated radiotherapy is the standard of care, but hadron therapy may be used in specific situations. Based on the available literature, no standard chemotherapy regimen can be recommended. Conclusion: There is currently no consensus on the use of chemotherapy in AdCC, either concomitantly to RT in a postoperative setting or at a metastatic stage. Further, the available targeted therapies do not yet provide significant tumour response.

High-flow nasal oxygen for suspension laryngoscopy: a multicenter open-label study.

In this study, we aimed to assess the efficacy of high-flow nasal oxygen (HFNO) to maintain blood peripheral oxygen saturation (SpO2) in patients undergoing suspension laryngoscopy under general anesthesia. Adult patients were included in this bicenter study. After face-mask oxygenation, HFNO at a flow rate of 70 L min-1 and fraction of inspired oxygen 100% was initiated at loss of consciousness. At the end of HFNO, blood gas analysis was performed. Of the 29 included patients, five (17.2%; 95% confidence interval [CI]: 7.6-34.5) presented SpO2 <95% during the first 15 minutes of the procedure and eight patients (27.6%; 95% CI: 14.7-45.7) presented SpO2 <95% throughout the procedure. Six patients (20.7%; 95% CI: 9.8-38.4) required rescue jet ventilation. Median apnea time before SpO2 <95% was 13.5 (interquartile range [IQR]: 10-17.7) minutes. Arterial carbon dioxide tension at the end of the procedure or at the time of study discontinuation was 9.73 (IQR: 8.8-10.9) kPa and was higher than 8 kPa in 88.9% (95% CI: 71.9-96.1) of patients. HFNO was associated with a relatively high incidence of suboptimal oxygen saturation and hypercapnia during suspension laryngoscopy under general anesthesia and may not be considered the reference technique.

New Therapeutic Approach for Intestinal Fibrosis Through Inhibition of pH-Sensing Receptor GPR4.

BACKGROUND: Patients suffering from inflammatory bowel diseases (IBDs) express increased mucosal levels of pH-sensing receptors compared with non-IBD controls. Acidification leads to angiogenesis and extracellular matrix remodeling. We aimed to determine the expression of pH-sensing G protein-coupled receptor 4 (GPR4) in fibrotic lesions in Crohn's disease (CD) patients. We further evaluated the effect of deficiency in Gpr4 or its pharmacologic inhibition. METHODS: Paired samples from fibrotic and nonfibrotic terminal ileum were obtained from CD patients undergoing ileocaecal resection. The effects of Gpr4 deficiency were assessed in the spontaneous Il-10-/- and the chronic dextran sodium sulfate (DSS) murine colitis model. The effects of Gpr4 deficiency and a GPR4 antagonist (39c) were assessed in the heterotopic intestinal transplantation model. RESULTS: In human terminal ileum, increased expression of fibrosis markers was accompanied by an increase in GPR4 expression. A positive correlation between the expression of procollagens and GPR4 was observed. In murine disease models, Gpr4 deficiency was associated with a decrease in angiogenesis and fibrogenesis evidenced by decreased vessel length and expression of Edn, Vegfα, and procollagens. The heterotopic animal model for intestinal fibrosis, transplanted with terminal ileum from Gpr4-/- mice, revealed a decrease in mRNA expression of fibrosis markers and a decrease in collagen content and layer thickness compared with grafts from wild type mice. The GPR4 antagonist decreased collagen deposition. The GPR4 expression was also observed in human and murine intestinal fibroblasts. The GPR4 inhibition reduced markers of fibroblast activation stimulated by low pH, notably Acta2 and cTgf. CONCLUSIONS: Expression of GPR4 positively correlates with the expression of profibrotic genes and collagen. Deficiency of Gpr4 is associated with a decrease in angiogenesis and fibrogenesis. The GPR4 antagonist decreases collagen deposition. Targeting GPR4 with specific inhibitors may constitute a new treatment option for IBD-associated fibrosis.

Knock-out of ß-glucosidase 2 has no influence on dextran sulfate sodium-induced colitis.

BACKGROUND/AIMS: The non-lysosomal glucosylceramidase, ß-glucosidase (Gba2), hydrolyzes glucosylceramide to glucose and ceramide (Cer). Cer is a potent second-messenger lipid that plays an important role in signaling cascades involved in apoptosis. The aim of this study was to investigate whether Gba2 knock-out (Gba2(-/-)) affects the extent of dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: Acute colitis was induced in wild-type (WT) and Gba2(-/-) mice by administration of 2% DSS in drinking water. After 7 days, mice underwent colonoscopy and were sacrificed. RESULTS: Both DSS-treated WT (n = 10) and Gba2(-/-) (n = 12) mice showed elevated histological and endoscopic scores compared to respective H(2)O controls (n = 9 each). However, no significant differences between the DSS groups were detected. Flow cytometric analysis of propidium iodide staining, cleavage of caspases-3 and -8, indicative for apoptosis, as well as Cer levels were not altered in DSS-treated WT or Gba2(-/-) mice. Gba2(-/-) resulted in slightly decreased expression of glucocerebrosidase (Gba1) as well as in upregulation of proteins being involved in cellular regeneration, such as STAT3 (signal transducer and activator of transcription), JNK and iNOS, upon DSS treatment. CONCLUSION: We demonstrate that Gba2(-/-) does not affect the extent of DSS-induced inflammation in mice, however, it might be involved in tissue regeneration in response to toxic agents.

Hypoxia Reduces the Transcription of Fibrotic Markers in the Intestinal Mucosa.

INTRODUCTION: Intestinal fibrosis, characterized by excessive deposition of extracellular matrix proteins, is a common and severe clinical complication of inflammatory bowel disease (IBD). However, the mechanisms underlying fibrosis remain elusive, and currently, there are limited effective pharmacologic treatments that target the development of fibrosis. Hypoxia is one of the key microenvironmental factors influencing intestinal inflammation and has been linked to fibrosis. OBJECTIVE: In the present study, we sought to elucidate the impact of hypoxia on fibrotic gene expression in the intestinal mucosa. METHODS: Human volunteers, IBD patients, and dextran sulphate sodium-treated mice were exposed to hypoxia, and colonic biopsies were collected. The human intestinal epithelial cell line Caco-2, human THP-1 macrophages, and primary human gut fibroblasts were subjected to hypoxia, and changes in fibrotic gene expression were assessed. RESULTS: Human volunteers subjected to hypoxia presented reduced transcriptional levels of fibrotic and epithelial-mesenchymal transition markers in the intestinal mucosa. IBD patients showed a trend towards a decrease in tissue inhibitor of metalloproteinase 1 protein expression. In mice, hypoxic conditions reduced the colonic expression of several collagens and matrix metalloproteinases. Hypoxic Caco-2 cells, THP-1 cells, and primary gut fibroblasts showed a significant downregulation in the expression of fibrotic and tissue remodelling factors. CONCLUSIONS: Stabilization of hypoxia-inducible factors might represent a novel therapeutic approach for the treatment of IBD-associated fibrosis.

Administration of the Hyper-immune Bovine Colostrum Extract IMM-124E Ameliorates Experimental Murine Colitis.

BACKGROUND AND AIMS: Inflammatory bowel disease [IBD] is accompanied by lesions in the epithelial barrier, which allow translocation of bacterial products from the gut lumen to the host's circulation. IMM-124E is a colostrum-based product containing high levels of anti-E.coli-LPS IgG, and might limit exposure to bacterial endotoxins. Here, we investigated whether IMM-124E can ameliorate intestinal inflammation. METHODS: Acute colitis was induced in WT C57Bl/6J mice by administration of 2.5% dextran sodium sulphate [DSS] for 7 days. T cell transfer colitis was induced via transfer of 0.5 x 106 naïve T cells into RAG2-/- C57Bl/6J mice. IMM-124E was administered daily by oral gavage, either preventively or therapeutically. RESULTS: Treatment with IMM-124E significantly ameliorated colitis in acute DSS colitis and in T cell transfer colitis. Maximum anti-inflammatory effects were detected at an IMM-124E concentration of 100 mg/kg body weight, whereas 25 mg/kg and 500 mg/kg were less effective. Histology revealed reduced levels of infiltrating immune cells and less pronounced mucosal damage. Flow cytometry revealed reduced numbers of effector T helper cells in the intestine, whereas levels of regulatory T cells were enhanced. IMM-124E treatment reduced the DSS-induced increase of serum levels of lipopolysaccharide [LPS]-binding protein, indicating reduced systemic LPS exposure. CONCLUSIONS: Our results demonstrate that oral treatment with IMM-124E significantly reduces intestinal inflammation, via decreasing the accumulation of pathogenic T cells and concomitantly increasing the induction of regulatory T cells. Our study confirms the therapeutic efficacy of IMM-124E in acute colitis and suggests that administration of IMM-124E might represent a novel therapeutic strategy to induce or maintain remission in chronic colitis.