A 5G V2X Ecosystem Providing Internet of Vehicles.

The Fifth Generation (5G) cellular network can be considered the way to the ubiquitous Internet and pervasive paradigm.The Internet of Vehicles (IoV) uses the network infrastructure to allow cars to be connected to new radio technologies, and can be supported by 5G networks. In this way, the Vehicle-to-Everything (V2X) integration needs 5G connections unavoidably. This paper presents a 5G V2X ecosystem to provide IoV. The proposed ecosystem is based on the Software-Defined Networking (SDN) concept. Considering vehicles as entertainment consumer points, the network infrastructure must be huge enough to guarantee delivery and quality. For this purpose, this paper evaluates vehicular Internet-based video services traffic and Vehicle-to-Vehicle (V2V) communications in urban and rural scenarios. Simulations were performed through the Network Simulator ns-3, employing millimeter Wave (mmWave) communications. Three metrics, data transfer rate, transmission delay, and Packet Delivery Ratio (PDR), were analyzed and compared for rural and urban IoV scenarios. The results have shown satisfactory performance to the IoV communications requirements when adopting the 5G network with V2X communications.

Transient elastography evaluation of hepatic and spleen stiffness in patients with hepatosplenic schistosomiasis.

BACKGROUND: Hepatosplenic schistosomiasis (HES) has not been evaluated by transient elastography so far and its correlation with ultrasound variables remains to be defined. AIMS: The aim of this study was to describe the parameters of liver and spleen stiffness in HES assessed by transient elastography in comparison with cirrhotics and controls evaluating its correlation with ultrasonographic data. PATIENTS AND METHODS: HES, hepatitis C virus-cirrhotic, and control patients were included in this sectional study. Liver and spleen stiffness were compared among the three groups. The ultrasonographic parameters were compared with transient elastography in HES patients. RESULTS: Thirty HES, 30 hepatitis C virus-cirrhotic patients, and 17 controls were included. Those with HES presented liver stiffness that was significantly higher than the controls and lower than the cirrhotics: 9.7 (3.6-75.0) versus 3.7 (2.8-5.4) versus 27.0 (14.7-61.5) kPa (P<0.001). Spleen stiffness values were comparable between hepatosplenic and cirrhotics: 66.4 (25.7-75.0) versus 69.1 (18.0-75.0) kPa (P=0.78) and were significantly higher than the controls 16.5 kPa (6.3-34.3) (P<0.001). In patients with HES, high spleen stiffness was associated with right liver lobe diameter (P=0.015), splenic artery resistance index (P=0.002), portal vein diameter (P=0.021), portal vein area (P=0.008), portal vein congestion index (P=0.035), splenic vein diameter (P=0.013), and spleen diameter (P=0.021). CONCLUSION: Liver stiffness may be a useful tool to differentiate portal hypertension related to cirrhosis from that of HES. High spleen stiffness is a potential surrogate marker of portal hypertension in this population.

Intravoxel Incoherent Motion Diffusion Weighted MR Imaging at 3.0 T: Assessment of Steatohepatitis and Fibrosis Compared with Liver Biopsy in Type 2 Diabetic Patients.

OBJECTIVE: To evaluate the capability of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) to assess steatohepatitis and fibrosis determined by histopathology in type 2 diabetic patients. METHODS: Fifty-nine type 2 diabetic patients (49 women, 10 men; mean age, 54 ± 9 years) were submitted to liver biopsy for the evaluation of non-alcoholic fatty liver disease (NAFLD) and underwent DWI on a 3.0T MR system using 10 b values. Institutional approval and patient consent were obtained. Pure molecular-based (D), perfusion-related (D*), and vascular fraction (f) were calculated using a double exponential model and least squares curve fitting. D, D*, and f were compared between patients with and without steatohepatitis and between patients with and without fibrosis. The variables were compared by using the Ranksum test and Student t-test. RESULTS: Steatohepatitis was observed in 22 patients and fibrosis in 16 patients. A lower D median (0.70 s/mm2 vs. 0.83 s/mm2, p<0.05) and a lower D* median (34.39 s/mm2 vs. 45.23 s/mm2, p<0.05) were observed among those with steatohepatitis. A lower D median (0.70 s/mm2 vs. 0.82 s/mm2, p<0.05) and a lower D* median (35.01 s/mm2 vs. 44.76 s/mm2, p=0.05) were also observed among those with fibrosis. CONCLUSION: IVIM-DWI has the potential to aid in the characterization of steatohepatitis and fibrosis.

Prevalence, variability, and outcomes in portal hypertensive colopathy: a study in patients with cirrhosis and paired controls.

BACKGROUND: Management of portal hypertensive colopathy (PHC) has been challenged by controversial results in its prevalence and clinical relevance. OBJECTIVE: To describe the PHC prevalence and to evaluate the variability in diagnosis, the relation to severity of liver disease, and the incidence of severe outcomes. DESIGN: Cross-sectional study. SETTING: Endoscopic unit of a tertiary-care academic center in Rio de Janeiro, Brazil. PATIENTS: Patients with cirrhosis with portal hypertension and controls paired for age and sex. INTERVENTIONS: All patients were submitted to standard and image-enhanced colonoscopies, which were recorded in a coded video file and analyzed twice by a blinded endoscopist. MAIN OUTCOME MEASUREMENTS: The prevalence of PHC. RESULTS: A total of 51 patients with cirrhosis (55% male, mean age 59 years) and 51 healthy controls (43% male, mean age 61 years) were included. The top ranking colonoscopic findings were angiodysplasia-like lesions, nonspecific vascular pattern, red spots, and colorectal varices, all significantly more frequent in patients with cirrhosis compared with controls. PHC prevalence was 71% in patients with cirrhosis. For PHC, interobserver and intraobserver agreement (k values [standard error]) were 0.68 (0.09) and 0.63 (0.10), respectively. Intraobserver agreement for colonoscopic findings was satisfactory. PHC was not related to more severe liver disease or liver stiffness. Only 5 patients developed severe outcomes during follow-up. LIMITATIONS: The exclusion of patients with cirrhosis without esophageal varices and the absence of an interobserver agreement analysis by double-blinded endoscopists. CONCLUSION: PHC was highly prevalent in patients with cirrhosis, and its diagnostic agreement was satisfactory. PHC is not associated with relevant severe outcomes in a 12-month follow-up.

Interobserver variability in transient elastography analysis of patients with chronic hepatitis C.

BACKGROUND & AIMS: Transient elastography based on liver stiffness measurement is a non-invasive method to assess hepatic fibrosis. However, interobserver variability has led to controversy over its use in fibrosis evaluation. To evaluate the interobserver variation in transient elastography in chronic hepatitis C. METHODS: We performed a cross-sectional study, analysing findings from two experienced operators who each assessed 195 patients by transient elastography on the same day. Liver stiffness measurement used to define fibrosis stages, based on METAVIR score, was: <7.1 as F0F1, 7.1-9.4 as F2, 9.5-12.4, as F3 and >12.4 kPa as F4. We also assessed interobserver variation in identification of potential oesophageal varices screening based on transient elastography. RESULTS: The interobserver intraclass correlation coefficient was 0.940 (95% CI 0.863-0.967) and measurements made by operators correlated [Spearman's ρ = 0.924; P < 0.001]. However, the median liver stiffness measurement assessed by first operators was higher (11.5 vs 9.8 kPa; P < 0.001). The discordance between operators was 35% for at least one stage of fibrosis and 5% for two or more stages. Interobserver reliability values were κ = 0.61 for fibrosis stages F ≥ 2 and κ = 0.80 for cirrhosis. Among the 74 patients determined to have cirrhosis by at least one operator, there was considerable discordance in identification of those with indication for oesophageal varices screening (κ values from 0.13 to 0.61) according to several cut-offs. CONCLUSION: Although a high correlation of liver stiffness measurement between operators, interobserver variability in transient elastography was not negligible. This method should not be used as the only screening tool for oesophageal varices in chronic hepatitis C.

Enhanced liver fibrosis panel as a predictor of liver fibrosis in chronic hepatitis C patients.

BACKGROUND: Evaluation of fibrosis is crucial in the assessment of chronic hepatitis C (CHC). The enhanced liver fibrosis (ELF) is a serological panel including hyaluronic acid (HA), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), and amino-terminal propeptide of type III procollagen (PIIINP) that has shown good results in predicting liver fibrosis in distinct scenarios of chronic liver diseases. AIMS: We aimed to assess the performance of ELF on the detection of fibrosis and cirrhosis in a CHC patient cohort and to compare the results of ELF and transient elastography (TE-Fibroscan) using liver biopsy as reference. PATIENTS AND METHODS: One hundred twenty patients were prospectively evaluated by TE and ELF using an ADVIA Centaur automated system. The ELF score was calculated using the manufacturer's algorithm. Biopsies were classified according to the METAVIR score. Receiver operator characteristic curve analyses were performed to evaluate the accuracy of ELF and TE. RESULTS: The area under the receiver operator characteristic curve (AUROC) of ELF for the diagnosis of significant fibrosis was 0.81 [95% confidence interval (CI), 0.73-0.87], for advanced fibrosis was 0.82 (95% CI, 0.74-0.88), and for cirrhosis was 0.78 (95% CI, 0.70-0.85). Using the proposed cutoffs, ELF overestimated fibrosis in 66% (81/120) of cases and underestimated in 3% (3/120). We found no statistically significant difference when comparing the AUROC of ELF and TE for diagnosing fibrosis or cirrhosis. CONCLUSIONS: ELF panel is a good noninvasive fibrosis marker and showed similar results to TE in CHC patients. However, new cutoff points need to be established to improve its performance on patients with CHC.

Endoscopic management of ureteral calculus in a patient with ureterosigmoidostomy diversion.

Lithiasis after urinary diversion is an uncommon condition that poses therapeutic challenges. The authors report the case of a patient submitted to cystectomy and ureterosigmoidostomy 35 years ago due to bladder endometriosis. The patient presented with a ureteral stone and was treated by retrograde endoscopic extraction.

Endoscopic management of ureteral calculus in a patient with ureterosigmoidostomy diversion

Lithiasis after urinary diversion is an uncommon condition that poses therapeutic challenges. The authors report the case of a patient submitted to cystectomy and ureterosigmoidostomy 35 years ago due to bladder endometriosis. The patient presented with a ureteral stone and was treated by retrograde endoscopic extraction.

Yield of Contrast-Enhanced Power Doppler Endoscopic Ultrasonography and Strain Ratio Obtained by EUS-Elastography in the Diagnosis of Focal Pancreatic Solid Lesions.

OBJECTIVE: Although endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is the gold standard for diagnosing pancreatic lesions, its negative predictive value is suboptimal. Our aim was to evaluate the yield of contrast-enhanced EUS (CED-EUS) and of strain ratio EUS-elastography (SR-E-EUS) for differentiating pancreatic solid lesions. METHODS: Forty-seven patients (27 men, 20 women, 70 ± 11 years) were consecutively involved in this single-center, prospective study. They were submitted to EUS, SR-E-EUS, CED-EUS with Sonovue(®), and EUS-FNA. The final diagnosis was based on the histological assessment of EUS-FNA and/or surgical specimens when available, and on follow-up of at least 6 months. RESULTS: From the 47 focal pancreatic lesions included, 13 (28%) were benign and 34 (72%) malignant. Patients with malignancy were older (70 ± 11 vs. 61 ± 8, P = 0.003), and had larger lesions (34 ± 12 mm vs. 22 ± 11 mm, P = 0.03). Malignant lesions had higher SR-E-EUS (31 ± 32 vs. 8 ± 9, P = 0.001) and more hypovascular pattern (93% vs. 33%, P < 0.001). Logistic regression determined that only hypovascularity (OR = 2.6, 95%CI: 1.5-130, P = 0.02) was independently predictive of malignancy. ROC analysis for SR-E-EUS yielded an optimal cutoff of 8 (AUC 0.91, 95%CI: 0.74-0.98) for the best power distinction for malignancy. There was no significant difference concerning sensitivity (79%, 90%, 93%) and specificity rates (85%, 75%, 67%) of EUS-FNA, SR-E-EUS, and CED-EUS, respectively. By analysis of the inconclusive EUS-FNA subset (9 patients, 19%), SR-E-EUS > 8 and hypovascularity showed sensitivity of 80% and 100%, and specificity of 67% and 67%, respectively. CONCLUSION: The clinical utility of CED-EUS and SR-E-EUS remains questionable. The accuracies of CED-EUS and SR-E-EUS are similar to EUS-FNA. Hypovascularity was independently predictive of malignancy. Patients with inconclusive EUS-FNA could benefit from CED-EUS due to the high sensitivity of hypovascularity for diagnosing malignancy.

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients

Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20 percent. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24 percent) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients.

Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20%. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24%) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.

Occult hepatitis B virus infection and lamivudine-resistant mutations in isolates from renal patients undergoing hemodialysis.

BACKGROUND AND AIMS: Patients undergoing hemodialysis are at risk of infection with both hepatitis B virus (HBV) and hepatitis C virus (HCV). Occult HBV infection is usually associated with low levels of HBV and is frequently detected in HCV-infected patients. The aims of the present study were to compare the prevalence of occult HBV infection among anti-HCV-positive and anti-HCV-negative patients undergoing hemodialysis, and characterize the molecular patterns of HBV isolates from patients with occult infection. METHODS: Serum samples from 100 patients negative for hepatitis B surface antigen undergoing hemodialysis, half of whom were positive for anti-HCV antibodies, were tested for the presence of HBV-DNA using semi-nested polymerase chain reaction (PCR). PCR products of the S gene were directly sequenced. RESULTS: HBV-DNA was detected in 15 samples. There were no significant differences in HCV status, sex, age, time of dialysis, alanine aminotransferase levels or HBV serological markers between patients with or without occult HBV infection, with the exception of antibody to hepatitis B core antigen (anti-HBc)-only serological marker (P = 0.003). All six HBV isolates that could be sequenced were of genotype A/subgenotype A1. Four of these six HBV isolates contained mutations associated with lamivudine resistance in the DNA polymerase (two with L180M/M204V and two with rt173V/180M/204V) and a specific substitution (Y100C) in the HBV small surface protein. CONCLUSIONS: HBV isolates with the identified substitutions have the potential to spread silently by nosocomial transmission within the hemodialysis unit. These results have potential implications for the management of patients with occult HBV infection undergoing hemodialysis.

Precut papillotomy: a risky technique not only for experts but also for average endoscopists skilled in ERCP.

PURPOSE: To evaluate the success and complication rates of early precut papillotomy in difficult biliary cannulations performed by an average endoscopist skilled in ERCP. METHODS: We studied 146 consecutive ERCPs during a 27-month period. Precutting was instituted if cannulation failed after 10-15 min. Standard papillotomy was performed in the rest. The analysis was divided into initial period (1st year) and subsequent period (following 15 months). RESULTS: The success rate of cannulation was 95% (139/146). Standard papillotomy was performed in 103/146 (71%) patients. In the remainder, cannulation was successful after precutting in 36/43 (84%) patients. The complication rate was 10% (8/103 in the standard vs. 7/43 in the precut group, P = 0.14). All complications of the standard group were mild. In the precut group, there were three moderate to severe complications. There were no differences between the two periods. CONCLUSIONS: Precut papillotomy can be an effective and relatively safe procedure when performed by an average endoscopist skilled in ERCP. Although the complication rate of precutting tended to be higher than standard papilotomy, this was reasonable since it increased the success of selective biliary cannulation in 25% of cases. Complication rates did not improve with experience.

Pancreatic endocrine tumors: a large single-center experience.

OBJECTIVES: Pancreatic endocrine tumors (PETs) are infrequent, which makes large experiences unlikely. Our aim was to describe a large single-center experience with PETs and the use of endoscopic ultrasound (EUS) and a cancer staging system (TNM). METHODS: This study involves a retrospective analysis of 86 patients (44 men; age, 58 +/- 14 years) who underwent EUS-fine needle aspiration (EUS-FNA). Immunohistochemistry was used. Lesions were classified as recommended by TNM classification. RESULTS: Typical EUS features were well-demarcated, hypoechoic, solid, homogeneous lesions. Ninety percent had the diagnosis obtained by EUS-FNA. Twelve PETs (14%) were functioning, 8 (9.3%) were cystic, and 14 (16%) were 10 mm or smaller. Nonfunctional PETs and larger lesions were more advanced. The TNM stage was I in 24, II in 10, III in 18, and IV in 34 patients. Sixteen patients (27%) died, and 30 patients (52%) had progression/recurrence during the follow-up (34 +/- 27 months). TNM stage and surgery with curative intent were related to progression. The overall 5-year survival was 60%. The mean survival time was 94 +/- 12 months for stage I, 52 +/- 12 months for stage III, and 54 +/- 7 months for stage IV (P = 0.06). CONCLUSIONS: Nonfunctional PETs were more common and advanced. The EUS-FNA has a high accuracy for diagnosing PETs. Progression and poorer survival were associated with TNM stage.

EUS-FNA predicts 5-year survival in pancreatic endocrine tumors.

BACKGROUND: Pancreatic endocrine tumors (PETs) differ in clinical behavior and prognosis. Determination of malignant potential through specimens obtained by EUS-FNA can help in the management of these patients. OBJECTIVE: To determine the value of EUS-FNA for diagnosing PETs and for classifying their underlying malignant potential based on the World Health Organization (WHO) classification. DESIGN: Single-center, retrospective, cohort study. SETTING: Tertiary referral hospital. PATIENTS: This study involved 86 consecutive patients (44 men, mean age 58 +/- 14 years) who had been diagnosed with PETs and submitted to EUS-FNA from January 1999 to August 2008. INTERVENTION: EUS-FNA of a pancreatic mass and/or a metastasis site. Immunohistochemistry on microbiopsies or on monolayer cytology was routinely used. The lesions were classified as recommended by the WHO. MAIN OUTCOME MEASUREMENTS: EUS-FNA sensitivity and 5-year survival rate. RESULTS: Overall, in 90% (77 of 86) of patients in this study, PET was diagnosed with EUS-FNA. The sensitivity did not vary with tumor size, type, location, or the presence of hormonal secretion. Of 86 patients, 30 (35%) were submitted to surgical resection. The kappa correlation index between the WHO classification obtained by EUS-FNA and by surgery was 0.38 (P = .003). Major discrepancies were found in the group of patients diagnosed with endocrine tumor of uncertain behavior by EUS-FNA, because 72% turned out to have well-differentiated endocrine carcinoma. Sixteen patients (27%) died during a mean follow-up period of 34 +/- 27 months. The 5-year survival rates were 100% for endocrine tumors, 68% for well-differentiated endocrine carcinomas, and 30% for poorly differentiated endocrine carcinomas (P = .008, log-rank test). LIMITATIONS: Retrospective design, selection bias, and small sample size. CONCLUSIONS: This largest single-center experience to date demonstrated the accuracy of EUS-FNA in diagnosing and determining the malignant behavior of PETs. EUS-FNA findings predict 5-year survival in patients with PETs.

Comparison of three methods of nutritional assessment in liver cirrhosis: subjective global assessment, traditional nutritional parameters, and body composition analysis.

BACKGROUND: Liver cirrhosis affects the results of many of the traditional techniques currently used to evaluate nutritional status. Our aim was to compare the traditional two-compartment model (subjective global assessment and anthropometry and blood tests) of nutritional assessment with a multicompartmental model (body composition analysis) in patients with cirrhosis. METHODS: Seventy-nine patients and 17 control subjects were studied. Subjective global assessment, anthropometry and blood tests, and body composition analysis were performed for each. The two most important compartments were body cell mass and total body fat. The subjects were classified by each method as well nourished or moderately or severely malnourished. RESULTS: Twenty-five patients (31.6%) were malnourished according to the subjective global assessment, 2 (6.3%) with Child's class A cirrhosis, 10 (34.5%) with class B, and 13 (72.2%) with class C, whereas 24 (30.4%) were malnourished according to the traditional model, 5 (15.6%) in the Child's A group, 8 (27.6%) in B, and 11 (61.1%) in C. According to the multicompartmental model, 48 patients (60.1%) were malnourished, 11 (34.4%) in Child's A, 20 (69%) in B, and 17 (94.4%) in C. The use of the multicompartmental model increased the prevalence of malnutrition by more than 60% in Child's classes A and B patients and by more than 20% in Child's class C patients. CONCLUSIONS: Traditional nutritional assessment, although easier, underestimated the prevalence and severity of malnutrition in patients with cirrhosis. The underestimation was more pronounced in Child's class A and B patients.

Effect of liver cirrhosis on body composition: evidence of significant depletion even in mild disease.

BACKGROUND AND AIMS: Malnutrition is common in liver cirrhosis patients. However, it is under-diagnosed because liver disease affects the traditional nutritional assessment. An understanding of changes in body composition and the establishment of the tissue-loss pattern in liver cirrhosis patients could help practitioners to better manage malnutrition in this setting. The aims of this study were: to quantify body composition changes, to determine tissue loss pattern, and to assess the relation of these to the severity of hepatic dysfunction. METHODS: Seventy-nine patients and 17 controls were studied. Total body water and extracellular water were measured using dilution techniques. Intracellular water and body cell mass were calculated from these parameters. Total body fat was obtained using absorptiometry. RESULTS: Extracellular water was increased and intracellular water was decreased in patients. The two major compartments (body cell mass and body fat) were significantly reduced, mainly in patients with moderate and severe disease. However, significant losses occurred even in Child-Pugh class A patients. We established a tissue-loss pattern. In Child-Pugh class A patients body fat loss predominated. Child-Pugh class B patients had losses in at least one of the two compartments. Most Child-Pugh class C patients had simultaneous depletion in both compartments. CONCLUSIONS: Liver cirrhosis was characterized by a significant reduction in body cell mass and body fat and by a redistribution of body water. Significant losses occurred even in patients with mild disease. There was a more pronounced loss of fat in the initial stages, followed by an accelerated loss of body cell mass in the advanced stages of liver cirrhosis.