Hormonal regulation of bicarbonate secretion in the biliary epithelium.

Bicarbonate excretion in bile is a major function of the biliary epithelium. It is driven by the apically located Cl-/HCO3- exchanger which is functionally coupled with a cAMP-dependent Cl- channel (CFTR). A number of hormones and/or neuropeptides with different mechanisms and at different intracellular levels regulate, in concert, the processes underlying bicarbonate excretion in the biliary epithelium. Secretin induces a bicarbonate rich choleresis by stimulating the activity of the Cl-/HCO3- exchanger by cAMP and protein kinase A mediated phosphorylation of CFTR regulatory domain. Protein phosphatase 1/2A are involved in the run-down of secretory stimulus after secretin removal. Acetylcholine potentiates secretin-choleresis by inducing a Ca(++)-calcineurin mediated "sensitization" of adenyl cyclase to secretin. Bombesin and vasoactive intestinal peptide also enhance the Cl-/HCO3- exchanger activity, but the intracellular signal transduction pathway has not yet been defined. Somatostatin and gastrin inhibit basal and/or secretin-stimulated bicarbonate excretion by down-regulating the secretin receptor and decreasing cAMP intracellular levels induced by secretin

Phenotypical heterogeneity linked to adipose tissue dysfunction in patients with type 2 diabetes

Adipose tissue (AT) inflammation leads to increased free fatty acid (FFA) efflux and ectopic fat deposition, but whether AT dysfunction drives selective fat accumulation in specific sites remains unknown. The aim of the present study was to investigate the correlation between AT dysfunction, hepatic/pancreatic fat fraction (HFF, PFF) and the associated metabolic phenotype in patients with Type 2 diabetes (T2D). Sixty-five consecutive T2D patients were recruited at the Diabetes Centre of Sapienza University, Rome, Italy. The study population underwent clinical examination and blood sampling for routine biochemistry and calculation of insulin secretion [homoeostasis model assessment of insulin secretion (HOMA-β%)] and insulin-resistance [homoeostasis model assessment of insulin resistance (HOMA-IR) and adipose tissue insulin resistance (ADIPO-IR)] indexes. Subcutaneous (SAT) and visceral (VAT) AT area, HFF and PFF were determined by magnetic resonance. Some 55.4% of T2D patients had non-alcoholic fatty liver disease (NAFLD); they were significantly younger and more insulin-resistant than non-NAFLD subjects. ADIPO-IR was the main determinant of HFF independently of age, sex, HOMA-IR, VAT, SAT and predicted severe NAFLD with the area under the receiver operating characteristic curve (AUROC)=0.796 (95% confidence interval: 0.65-0.94, P=0.001). PFF was independently associated with increased total adiposity but did not correlate with AT dysfunction, insulin resistance and secretion or NAFLD. The ADIPO-IR index was capable of predicting NAFLD independently of all confounders, whereas it did not seem to be related to intrapancreatic fat deposition; unlike HFF, higher PFF was not associated with relevant alterations in the metabolic profile. In conclusion, the presence and severity of AT dysfunction may drive ectopic fat accumulation towards specific targets, such as VAT and liver, therefore evaluation of AT dysfunction may contribute to the identification of different risk profiles among T2D patients

No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder worldwide, reaching prevalence up to 90 % in obese patients with type 2 diabetes (T2D), and representing an independent risk factor for cardiovascular mortality. Furthermore, the coexistence of T2D and NAFLD leads to higher incidence of diabetes’ complications and additive detrimental liver outcomes. The existence of a close association between NAFLD and hypovitaminosis D, along with the anti-inflammatory and insulin-sensitizing properties of vitamin D, have been largely described, but vitamin D effects on hepatic fat content have never been tested in a randomized controlled trial. We assessed the efficacy and safety of 24-week oral high-dose vitamin D supplementation in T2D patients with NAFLD. Methods: This randomized, double-blind, placebo-controlled trial was carried out at the Diabetes Centre of Sapienza University, Rome, Italy, to assess oral treatment with cholecalciferol (2000 IU/day) or placebo in T2D patients with NAFLD. The primary endpoint was reduction of hepatic fat fraction (HFF) measured by magnetic resonance; as hepatic outcomes, we also investigated changes in serum transaminases, CK18-M30, N-terminal Procollagen III Propeptide (P3NP) levels, and Fatty Liver Index (FLI). Secondary endpoints were improvement in metabolic (fasting glycaemia, HbA1c, lipids, HOMA-IR, HOMA-β, ADIPO-IR, body fat distribution) and cardiovascular (ankle-brachial index, intima-media thickness, flow-mediated dilatation) parameters from baseline to end of treatment. Results: Sixty-five patients were randomized, 26 (cholecalciferol) and 29 (placebo) subjects completed the study. 25(OH) vitamin D significantly increased in the active treated group (48.15 ± 23.7 to 89.80 ± 23.6 nmol/L, P < 0.001); however, no group differences were found in HFF, transaminases, CK18-M30, P3NP levels or FLI after 24 weeks. Vitamin D neither changed the metabolic profile nor the cardiovascular parameters. Conclusions: Oral high-dose vitamin D supplementation over 24 weeks did not improve hepatic steatosis or metabolic/cardiovascular parameters in T2D patients with NAFLD. Studies with a longer intervention period are warranted for exploring the effect of long time exposure to vitamin D

Molecular identification and functional characterization of Mdr1a in rat cholangiocytes

Background & Aims: The multidrug resistance P-glycoprotein 170 gene products (mdr1a and 1b) are glycosylated plasma membrane proteins that function as adenosine triphosphate- dependent transmembrane export pumps for lipophilic xenobiotics of widely different structure. We assessed whether these P-glycoproteins ave functionally expressed in cholangiocytes. Methods: A reverse-transcription polymerase chain reaction was performed on RNA from a normal rat cholangiocyte cell line using mdr1-specific primers. Northern and Western blot analyses were performed on cholangiocytes immunoisolated from 2-week bile duct-ligated rats and cholangiocytes and isolated cholangiocyte membrane subfractions, respectively. Functional assays were performed in isolated bile duct units from bile duct-ligated rats and incubated with rhodamine 123, a P-glycoprotein substrate, with or without the P-glycoprotein inhibitors verapamil or GF120918, Results: A 400 - base pair fragment with 99% homology to the cytosolic domain of rat intestinal mdr1a (5' 1953-2350 3') was identified that hybridized to a 5.2-kilobase RNA transcript in a normal rat cholangiocyte cell line, isolated rat cholangiocytes, and ileum. Western analysis localized mdr1 to the apical membrane of cholangiocytes. Confocal microscopy showed active secretion of rhodamine 123 into the lumen of isolated bile duct units that was abolished by vanadate and P-glycoprotein competitive antagonists, verapamil and GF120918, in a dose-dependent manner. Conclusions: These findings provide the first molecular and functional evidence for the expression of mdr1a on the luminal membrane of cholangiocytes, where it may have a protective role

Whole-tumor perfusion CT in patients with advanced lung adenocarcinoma treated with conventional and antiangiogenetic chemotherapy : Initial experience

Purpose: To determine whether wide-volume perfusion computed tomography (CT) performed with a new generation scanner can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on the whole tumor mass in patients with locally advanced lung adenocarcinoma and to determine if changes in CT numbers correlate with the response to therapy as assessed by conventional response evaluation criteria in solid tumors (RECIST). Materials and Methods: Forty-five patients with unresectable lung adenocarcinoma underwent perfusion CT before and 40 and 90 days after chemotherapy and antiangiogenetic treatment. RECIST measurements and calculations of blood flow, blood volume, time to peak, and permeability were performed by two independent blinded radiologists. Pearson correlation coefficient was used to assess the correlation between baseline CT numbers. Baseline and follow-up perfusion parameters of the neoplastic lesions were tested overall for statistically significant differences by using the repeated-measures analysis of variance and then were also compared on the basis of the therapy response assessed according to the RECIST criteria. Results: Pearson correlation coefficient showed a significant correlation between baseline values of blood flow and blood volume (rho = 0.48; P = .001), time to peak and permeability (rho = 0.31; P = .04), time to peak and blood flow (rho = -0.66; P < .001), and time to peak and blood volume (rho = -0.39; P = .007). Blood flow, blood volume, and permeability values were higher in responding patients than in the other patients, with a significant difference at second follow-up for blood flow (P = .0001), blood volume (P = .02), and permeability (P = .0001); time to peak was higher in non-responding patients (P = .012). Conclusion: Perfusion CT imaging may allow evaluation of lung cancer angiogenesis demonstrating alterations in vascularity following treatment. (C)RSNA, 201

Increased circulating osteopontin levels in adult patients with type 1 diabetes mellitus and association with dysmetabolic profile

Objective: Osteopontin (OPN) is a sialoprotein implicated in different immunity and metabolic pathways. Capable of activating dendritic cells and inducing Th1-Th17-mediated tissue damage, OPN plays a significant role in the development/progression of several autoimmune diseases; interestingly, it was also shown that OPN participates in the acute pancreatic islets response to experimentally induced diabetes in non-obese diabetic (NOD) mice. Furthermore, OPN promotes adipose tissue dysfunction, systemic inflammation and insulin resistance. Our aims of this study were to evaluate circulating OPN levels in adult patients with type 1 diabetes mellitus (T1DM) compared to non-diabetic control participants and to unravel clinical and biochemical correlates of OPN concentration. Design: Case-control study. Methods: We enrolled 54 consecutive T1DM patients referred to our diabetes outpatient clinic at Sapienza University of Rome and 52 healthy sex and age-comparable controls. The study population underwent clinical evaluation, blood sampling for biochemistry and complete screening for diabetes complications. Serum OPN levels were measured by MILLIPLEX Multiplex Assays Luminex. Results: T1DM patients had significantly higher serum OPN levels than controls (17.2 +/- 12.9 vs 10.5 +/- 11.6 mg/ml, P=0.009). OPN levels correlated with T1DM, higher blood pressure, BMI, creatinine, gamma-GT, ALP and lower HDL; the association between high OPN levels and T1DM was independent from all confounders. No correlation was shown between OPN and HbA1c, C-peptide, insulin requirement, co-medications and diabetes duration. Conclusions: This study demonstrates for the first time in a case-control study that adults with T1DM have increased serum OPN levels, and that higher OPN concentrations are associated with an unfavorable metabolic profile in these patients

Development of a prediction model and risk score for procedure-related complications in patients undergoing percutaneous computed tomography-guided lung biopsy

OBJECTIVES: To propose a risk score predicting the potential occurrence of procedure-related complications in patients undergoing computed tomography (CT)-guided lung biopsy. METHODS: Institution review board approval was obtained. A total of 342 CT-guided lung biopsies were retrospectively evaluated taking into account procedure-related complications and associated risk factors, including patient gender and age, previous radiation therapy (RT) and/or chemotherapy (CHT), lesion size, depth and location, incomplete pulmonary fissures, associated diffuse lung diseases, previous pneumothorax (PNX), lung volumes, punctured fissures, thoracic access, needle size and operator experience. Complications were assessed on chest X-ray and/or CT scans. Stepwise logistic regression was used to identify risk factors, to evaluate their correlation with procedure-related complications and to calculate models of risk (MoRs). RESULTS: PNX requiring chest tube placement occurred in 39 patients (11.4%), high-grade pulmonary parenchymal haemorrhage occurred in 62 patients (18.1%) and haemothorax occurred in 12 patients (3.5%). Risk factors increasing the incidence of complications were lesion size (P = 0.01), lesion depth (P = 0.01) and incomplete pulmonary fissures (P = 0.01); previous chemo-radiation therapy was correlated to a lower incidence of complications (P = 0.01). MoR for PNX was as follows: risk base line = 60%; age = +0.15%/year; punctured fissures = +20%; incomplete fissures = +9%; previous CHT/RT = -10%. MoR for parenchymal haemorrhage was as follows: risk base line = 20%, lesion depth = +0.8%/mm; age = +0.25%/year; incomplete fissures = +15%. MoR for haemothorax was as follows: risk base line = 1%; previous PNX = +20%; incomplete fissures = 7%; both previous PNX and incomplete fissures = +67%. CONCLUSION: This study provides MoRs to predict the risk of complications in patients undergoing CT-guided percutaneous lung biopsies