bluuebunny/crossref_metadata_2025 huggingface dataset:
Population activity statistics dissect subthreshold and spiking variability in V1
Authors: Bányai Mihály , Koman Zsombor , Orbán Gergő
Published: March 2017

Response variability, as measured by fluctuating responses upon repeated performance of trials, is a major component of neural responses, and its characterization is key to interpret high dimensional population recordings. Response variability and covariability display predictable changes upon changes in stimulus and cognitive or behavioral state, providing an opportunity to test the predictive power of models of neural variability. Still, there is little agreement on which model to use as a building block for population-level analyses, and models of variability are often treated as a subject of choice. We investigate two competing models, the doubly stochastic Poisson (DSP) model assuming stochasticity at spike generation, and the rectified Gaussian (RG) model tracing variability back to membrane potential variance, to analyze stimulus-dependent modulation of both single-neuron and pairwise response statistics. Using a pair of model neurons, we demonstrate that the two models predict similar single-cell statistics. However, DSP and RG models have contradicting predictions on the joint statistics of spiking responses. To test the models against data, we build a population model to simulate stimulus change-related modulations in pairwise response statistics. We use single-unit data from the primary visual cortex (V1) of monkeys to show that while model predictions for variance are qualitatively similar to experimental data, only the RG model's predictions are compatible with joint statistics. These results suggest that models using Poisson-like variability might fail to capture important properties of response statistics. We argue that membrane potential-level modeling of stochasticity provides an efficient strategy to model correlations.

NEW & NOTEWORTHY Neural variability and covariability are puzzling aspects of cortical computations. For efficient decoding and prediction, models of information encoding in neural populations hinge on an appropriate model of variability. Our work shows that stimulus-dependent changes in pairwise but not in single-cell statistics can differentiate between two widely used models of neuronal variability. Contrasting model predictions with neuronal data provides hints on the noise sources in spiking and provides constraints on statistical models of population activity.
Acute Psychosis as Main Manifestation of Central Pontine Myelinolysis
Authors: Gopal Mangala , Parasram Melvin , Patel Harsh , Ilorah Chike , Nersesyan Hrachya
Published: March 2017

Central pontine myelinolysis (CPM) is an acute demyelinating neurological disorder affecting primarily the central pons and is frequently associated with rapid correction of hyponatremia. Common clinical manifestations of CPM include spastic quadriparesis, dysarthria, pseudobulbar palsy, and encephalopathy of various degrees; however, coma, “locked-in” syndrome, or death can occur in most severe cases. Rarely, CPM presents with neuropsychiatric manifestations, such as personality changes, acute psychosis, paranoia, hallucinations, or catatonia, typically associated with additional injury to the brain, described as extrapontine myelinolysis (EPM). We present a patient with primarily neuropsychiatric manifestations of CPM, in the absence of focal neurologic deficits or radiographic extrapontine involvement. A 51-year-old female without significant medical history presented with dizziness, frequent falls, diarrhea, generalized weakness, and weight loss. Physical examination showed no focal neurological deficits. Laboratory data showed severe hyponatremia, which was corrected rather rapidly. Subsequently, the patient developed symptoms of an acute psychotic illness. Initial brain magnetic resonance imaging (MRI) was unremarkable, although a repeat MRI two weeks later revealed changes compatible with CPM. This case demonstrates that acute psychosis might represent the main manifestation of CPM, especially in early stages of the disease, which should be taken into consideration when assessing patients with acute abnormalities of sodium metabolism.
Metabolic Syndrome in People Living with Human Immunodeficiency Virus: An Assessment of the Prevalence and the Agreement between Diagnostic Criteria
Authors: Nguyen Kim Anh , Peer Nasheeta , de Villiers Anniza , Mukasa Barbara , Matsha Tandi E. , Mills Edward J. , Kengne Andre Pascal
Published: March 2017

Objectives. We determined metabolic syndrome (MetS) prevalence and assessed the agreement between different diagnostic criteria in HIV-infected South Africans. Method. A random sample included 748 HIV-infected adult patients (79% women) across 17 HIV healthcare facilities in the Western Cape Province. MetS was defined using the Joint Interim Statement (JIS 2009), International Diabetes Federation (IDF 2005), and Adult Treatment Panel III (ATPIII 2005) criteria. Results. Median values were 38 years (age), 5 years (diagnosed HIV duration), and 392 cells/mm3 (CD4 count), and 93% of the participants were on antiretroviral therapy (ART). MetS prevalence was 28.2% (95%CI: 25–31.4), 26.5% (23.3–29.6), and 24.1% (21–27.1) by the JIS, IDF, and ATPIII 2005 criteria, respectively. Prevalence was always higher in women than in men (all p<0.001), in participants with longer duration of diagnosed HIV (all p≤0.003), and in ART users not receiving 1st-line regimens (all p≤0.039). The agreement among the three criteria was very good overall and in most subgroups (all kappa≥0.81). Conclusions. The three most popular diagnostic criteria yielded similarly high MetS prevalence in this relatively young population receiving care for HIV infection. Very good levels of agreement between criteria are unaffected by some HIV-specific features highlighting the likely comparable diagnostic utility of those criteria in routine HIV care settings.
The Role of Endoscopic Ultrasound in the Diagnosis and Management of Primary Gastric Lymphoma
Authors: Schizas Dimitrios , Ntanasis-Stathopoulos Ioannis , Tsilimigras Diamantis I. , Sioulas Athanasios D. , Moris Demetrios , Spartalis Eleftherios , Scotiniotis Ilias , Papanikolaou Ioannis S.
Published: March 2017

Endoscopic ultrasound (EUS) is considered a valuable diagnostic tool during the workup of malignant gastric lesions, including primary gastric lymphomas (PGL). Although endoscopy combined with multiple biopsies remains essential in the establishment of PGL diagnosis, EUS utilization in locoregional disease staging has been well documented in the literature. Data also support the possible role of EUS in prediction of response to first-line treatment, that is,Helicobacter pylorieradication. However, its application in the posttreatment setting remains problematic, since concordance rates between endosonography and histology findings during follow-up seem to vary substantially. The aim of the present review is to summarize all available data regarding the role of EUS in the management of PGL.
Effect of Mitomycin C on Myopic versus Astigmatic Photorefractive Keratectomy
Authors: Almosa Ashwag A. , Fawzy Samah M.
Published: March 2017

Purpose. Long-term mitomycin C (MMC) effects on photorefractive keratectomy (PRK) were compared in simple myopic and astigmatic patients. Methods. In this observational cohort study, subjects were selected based on preoperative and postoperative data collected from medical records; they were divided into simple myopia with/without MMC and myopic astigmatism with/without MMC groups. Haze, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective refraction, and K-reading were evaluated at 1-, 3-, 6-, and 12-month follow-ups.Results. One hundred fifty-nine eyes of 80 subjects (34 women and 46 men; mean age, 26.81 ± 7.74 years; range, 18–53 years; spherical powers, −0.50 to −8.00 DS; and cylindrical powers, −0.25 to −5.00 DC) were enrolled. One year postoperatively, the simple myopia with/without MMC groups showed no difference in UCVA (P=0.187), BCVA (P=0.163), or spherical equivalent (P=0.163) and a significant difference (P=0.0495) in K-reading; the haze formation difference was nonsignificant (P=0.056). Astigmatic groups with/without MMC showed a significant difference in K-reading (P<0.0001). MMC groups had less haze formation (P<0.0001).Conclusion. PRK with intraoperative MMC application showed excellent visual outcomes. MMC’s effect on astigmatic patients was significantly better with acceptable safety and minimal side effects.
Anxiety in Cancer Patients during18F-FDG PET/CT Low Dose: A Comparison of Anxiety Levels before and after Imaging Studies
Authors: Grilo Ana , Vieira Lina , Carolino Elisabete , Oliveira Cátia , Pacheco Carolina , Castro Maria , Alonso Juan
Published: March 2017

Objective. Assessing the level of anxiety in oncology patients who underwent18F-FDG PET/CT low dose scan and identifying the main reasons that generate anxiety.Material and Method. The study included 81 cancer patients submitted to the18F-FDG PET/CT low dose scan. Patients filled in the Scan Experience Questionnaire and the State-Trait Anxiety Inventory (STAI) before and after18F-FDG PET/CT low dose scan.Results. Substantial levels of anxiety were detected both before and after18F-FDG PET/CT low dose scan (STAI mean > 30), with a significant increase in the state of anxiety after scan performance (p<0.0001,Medianpre= 31.1, andMedianpos= 33.0).18F-FDG PET/CT low dose results are the main cause of anxiety both before (79.1%) and after (86.9%) the scan. The information provided by staff both before and on the18F-FDG PET/CT low dose day was classified mostly as completely understandable (70.5% and 75.3%, resp.) and as very useful (70.5% and 72.6%, resp.) and correlated positively with patients’ overall satisfaction with NM Department (rS=0.372,p=0.004andrS=0.528,p= 0.000, resp.), but not with anxiety levels.Conclusions. Patients perceive high levels of anxiety during the18F-FDG PET/CT low dose scan and the concern with scan results was pointed out as the main factor for that emotional reaction.
Image Encryption Algorithm Based on Hyperchaotic Maps and Nucleotide Sequences Database
Authors: Niu Ying , Zhang Xuncai , Han Feng
Published: March 2017

Image encryption technology is one of the main means to ensure the safety of image information. Using the characteristics of chaos, such as randomness, regularity, ergodicity, and initial value sensitiveness, combined with the unique space conformation of DNA molecules and their unique information storage and processing ability, an efficient method for image encryption based on the chaos theory and a DNA sequence database is proposed. In this paper, digital image encryption employs a process of transforming the image pixel gray value by using chaotic sequence scrambling image pixel location and establishing superchaotic mapping, which maps quaternary sequences and DNA sequences, and by combining with the logic of the transformation between DNA sequences. The bases are replaced under the displaced rules by using DNA coding in a certain number of iterations that are based on the enhanced quaternary hyperchaotic sequence; the sequence is generated by Chen chaos. The cipher feedback mode and chaos iteration are employed in the encryption process to enhance the confusion and diffusion properties of the algorithm. Theoretical analysis and experimental results show that the proposed scheme not only demonstrates excellent encryption but also effectively resists chosen-plaintext attack, statistical attack, and differential attack.
Capturing Genomic Evolution of Lung Cancers through Liquid Biopsy for Circulating Tumor DNA
Authors: Offin Michael , Chabon Jacob J. , Razavi Pedram , Isbell James M. , Rudin Charles M. , Diehn Maximilian , Li Bob T.
Published: March 2017

Genetic sequencing of malignancies has become increasingly important to uncover therapeutic targets and capture the tumor’s dynamic changes to drug sensitivity and resistance through genomic evolution. In lung cancers, the current standard of tissue biopsy at the time of diagnosis and progression is not always feasible or practical and may underestimate intratumoral heterogeneity. Technological advances in genetic sequencing have enabled the use of circulating tumor DNA (ctDNA) analysis to obtain information on both targetable mutations and capturing real-time Darwinian evolution of tumor clones and drug resistance mechanisms under selective therapeutic pressure. The ability to analyze ctDNA from plasma, CSF, or urine enables a comprehensive view of cancers as systemic diseases and captures intratumoral heterogeneity. Here, we describe these recent advances in the setting of lung cancers and advocate for further research and the incorporation of ctDNA analysis in clinical trials of targeted therapies. By capturing genomic evolution in a noninvasive manner, liquid biopsy for ctDNA analysis could accelerate therapeutic discovery and deliver the next leap forward in precision medicine for patients with lung cancers and other solid tumors.
Assessment of Medication Use among University Students in Ethiopia
Authors: Asmelashe Gelayee Dessalegn , Binega Gashaw
Published: March 2017

Background.The extent, nature, and determinants of medication use of individuals can be known from drug utilization studies.Objectives.This study intended to determine medication consumption, sharing, storage, and disposal practices of university students in Northwest Ethiopia.Methods.A descriptive cross-sectional study was conducted on 404 university students selected through stratified random sampling technique. Data were collected using self-administered questionnaire and analyzed with SPSS version 20 statistical software. Pearson’s Chi-square test of independence was conducted withP<0.05taken as statistically significant.Results.At 95.3% response rate, the prevalences of medication consumption and sharing were 35.3% (N=136) and 38.2% (N=147), respectively. One hundred (26%) respondents admitted that they often keep leftover medications for future use while the rest (N=285, 74%) discard them primarily into toilets (N=126, 44.2%). Evidence of association existed between medication taking and year of study (P=0.048), medication sharing and sex (P=0.003), and medication sharing and year of study (P=0.015).Conclusion.There is a high prevalence of medication consumption, medication sharing, and inappropriate disposal practices which are influenced by sex and educational status of the university students. Thus medication use related educational interventions need to be given to students in general.
Rate-Distortion and Rate-Energy-Distortion Evaluations of Compressive-Sensing Video Coding
Authors: Ji Bingyu , Li Ran , Wu Changan
Published: March 2017

Compressive-Sensing Video Coding (CSVC) is a new video coding framework based on compressive-sensing (CS) theory. This paper presents the evaluations on rate-distortion performance and rate-energy-distortion performance of CSVC by comparing it with the popular hybrid video coding standard H.264 and distributed video coding (DVC) system DISCOVER. Experimental results show that CSVC achieves a poor rate-distortion performance when compared with H.264 and DISCOVER, but its rate-energy-distortion performance has a distinct advantage; moreover, its energy consumption of coding is approximately invariant regardless of reconstruction quality. It can be concluded that, with a limited energy budget, CSVC outperforms H.264 and DISCOVER, but its rate-distortion performance still needs improvement.
ROS: Crucial Intermediators in the Pathogenesis of Intervertebral Disc Degeneration
Authors: Feng Chencheng , Yang Minghui , Lan Minghong , Liu Chang , Zhang Yang , Huang Bo , Liu Huan , Zhou Yue
Published: March 2017

Excessive reactive oxygen species (ROS) generation in degenerative intervertebral disc (IVD) indicates the contribution of oxidative stress to IVD degeneration (IDD), giving a novel insight into the pathogenesis of IDD. ROS are crucial intermediators in the signaling network of disc cells. They regulate the matrix metabolism, proinflammatory phenotype, apoptosis, autophagy, and senescence of disc cells. Oxidative stress not only reinforces matrix degradation and inflammation, but also promotes the decrease in the number of viable and functional cells in the microenvironment of IVDs. Moreover, ROS modify matrix proteins in IVDs to cause oxidative damage of disc extracellular matrix, impairing the mechanical function of IVDs. Consequently, the progression of IDD is accelerated. Therefore, a therapeutic strategy targeting oxidative stress would provide a novel perspective for IDD treatment. Various antioxidants have been proposed as effective drugs for IDD treatment. Antioxidant supplementation suppresses ROS production in disc cells to promote the matrix synthesis of disc cells and to prevent disc cells from death and senescence in vitro. However, there is not enough in vivo evidence to support the efficiency of antioxidant supplementation to retard the process of IDD. Further investigations based on in vivo and clinical studies will be required to develop effective antioxidative therapies for IDD.
Pitfalls in Interventional Pain Medicine: Hyponatremia after DDAVP for a Patient with Von Willebrand Disease Undergoing an Epidural Steroid Injection
Authors: Khan Talal W. , Yacoub Abdulraheem
Published: March 2017

Desmopressin (DDAVP), a synthetic analog of vasopressin, has been used in patients with von Willebrand disease (VWD), mild hemophilia A, and platelet dysfunction to reduce the risk of bleeding associated with surgical and interventional procedures. We report the case of a patient with VWD presenting with a bulging disc and radicular pain that underwent transforaminal epidural steroid injections. Her course was complicated with the interval development of headaches and dizziness symptomatic of moderate hyponatremia, likely due to excessive fluid intake. This report highlights a relatively rare side effect of DDAVP when used for prophylaxis in patients with VWD and reinforces the need for vigilance in these patients.
A Case of Cortical Deafness due to Bilateral Heschl Gyrus Infarct
Authors: Narayanan Santhosh , Majeed K. Abdul , Subramaniam Gomathy , Narayanan Arathi , Navaf K. M.
Published: March 2017

We report the case of a 58-year-old male who presented with an episode of seizure and abrupt onset hearing loss. Neuroimaging revealed acute infarcts in bilateral Heschl gyri. Objective tests of peripheral auditory function were essentially normal and a diagnosis of cortical deafness was made.
Frequency Reconfigurable Circular Patch Antenna with an Arc-Shaped Slot Ground Controlled by PIN Diodes
Authors: Chen Yao , Ye Longfang , Zhuo Jianliang , Liu Yanhui , Zhang Liang , Zhang Miao , Liu Qing Huo
Published: March 2017

In this paper, a compact frequency reconfigurable circular patch antenna with an arc-shaped slot loaded in the ground layer is proposed for multiband wireless communication applications. By controlling the ON/OFF states of the five PIN diodes mounted on the arc-shaped slot, the effective length of the arc-shaped slot and the effective length of antennas current are changed, and accordingly six-frequency band reconfiguration can be achieved. The simulated and measured results show that the antenna can operate from 1.82 GHz to 2.46 GHz, which is located in DCS1800 (1.71–1.88 GHz), UMTS (2.11–2.20 GHz), WiBro (2.3–2.4 GHz), and Bluetooth (2.4–2.48 GHz) frequency bands and so forth. Compared to the common rectangular slot circular patch antenna, the proposed arc-shaped slot circular patch antenna not only has a better rotational symmetry with the circular patch and substrate but also has more compact size. For the given operating frequency at 1.82 GHz, over 55% area reduction is achieved in this design with respect to the common design with rectangular slot. Since the promising frequency reconfiguration, this antenna may have potential applications in modern multiband and multifunctional mobile communication systems.
The Effect of Volume Fraction of Single-Walled Carbon Nanotubes on Natural Frequencies of Polymer Composite Cone-Shaped Shell Made from Poly(Methyl Methacrylate)
Authors: Meysami A. H. , Razavi H. , Golpayegani I. Fakhari , Bagheri V.
Published: March 2017

In this paper, the effect of volume fraction of single-walled carbon nanotubes on natural frequencies of polymer composite cone-shaped shells made from Poly(Methyl Methacrylate) (PMMA) is studied. In order to determine the characterization of materials reinforced with nanoparticles, the molecular dynamics and mixture rule has been used. The motion equations of composite shell based on the classical thin shells theory using Hamilton’s principle are obtained. Then, using the Ritz method, approximate analytical solution of the natural frequency is presented. Results indicate that the nanotubes have a noticeable effect on the natural frequencies.
Management of Residual Neuromuscular Blockade Recovery: Age-Old Problem with a New Solution
Authors: Green Michael S. , Venkatesh Archana Gundigi , Venkataramani Ranjani
Published: March 2017

Neostigmine has been traditionally used as the agent of choice to reverse Neuromuscular Blockade (NMB) after muscle paralysis during general anesthesia. However, the use of neostigmine has not been without untoward events. Sugammadex is a novel drug that selectively binds to aminosteroid nondepolarizing muscle relaxants and reverses even a deep level of NMB. Controversy exists regarding the optimal dose of sugammadex that is effective in reversing the NMB after the incomplete reversal with neostigmine and glycopyrrolate. We discuss a case where sugammadex reduced the time of the recovery from NMB in a patient who had incomplete antagonisms following adequate treatment with neostigmine, aiding timely extubation without persistent residual NMB, and hence prevented the requirement of postoperative ventilation and the improvement in patient care. More randomized control studies are needed in order to conclude the appropriate dose of sugammadex in cases of incomplete reversal.
Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice
Authors: Nemmar Abderrahim , Yuvaraju Priya , Beegam Sumaya , Fahim Mohamed A. , Ali Badreldin H.
Published: March 2017

CeO2 nanoparticles (CeO2 NPs) which are used as a diesel fuel additive are emitted in the particulate phase in the exhaust, posing a health concern. However, limited information exists regarding the in vivo acute toxicity of CeO2 NPs on multiple organs. Presently, we investigated the acute (24 h) effects of intratracheally instilled CeO2 NPs in mice (0.5 mg/kg) on oxidative stress, inflammation, and DNA damage in major organs including lung, heart, liver, kidneys, spleen, and brain. Lipid peroxidation measured by malondialdehyde production was increased in the lungs only, and reactive oxygen species were increased in the lung, heart, kidney, and brain. Superoxide dismutase activity was decreased in the lung, liver, and kidney, whereas glutathione increased in lung but it decreased in the kidney. Total nitric oxide was increased in the lung and spleen but it decreased in the heart. Tumour necrosis factor‐α increased in all organs studied. Interleukin‐ (IL‐) 6 increased in the lung, heart, liver, kidney, and spleen. IL‐1β augmented in the lung, heart, kidney, and spleen. Moreover, CeO2 NPs induced DNA damage, assessed by COMET assay, in all organs studied. Collectively, these findings indicate that pulmonary exposure to CeO2 NPs causes oxidative stress, inflammation, and DNA damage in multiple organs.
Modified FOA Applied to Parameter Extraction of Flux-Gate Core
Authors: Jiang Wenjuan , Shi Yunbo , Zhao Wenjie
Published: March 2017

The accuracy of the magnetic core model is important to the analysis and design of the flux-gate sensor. The Jiles-Atherton model (J-A model) is the mostly used model to describe the hysteresis characteristics of the flux-gate core. But the parameters of J-A model are difficult to identify. In this paper, Fruit Fly Optimization Algorithm (FOA) is proposed to identify the parameters of the J-A model. In order to enhance the performance of the identification, a Modified Fruit Fly Optimization Algorithm (MFOA) is applied to extract the parameters of the flux-gate core. The effectiveness of MFOA is verified through five typical test functions. The influence of variation factor h on the performance of MFOA is discussed. The impact of variation factor h on parameters extraction of hysteresis loop is studied. It is shown that MFOA with appropriate selection of variation factor h will get better performance in the accuracy, stability, and simulation time compared to those of PSO and FOA.
Impact of Personalised Patient Education on Bowel Preparation for Colonoscopy: Prospective Randomised Controlled Trial
Authors: Elvas Luís , Brito Daniel , Areia Miguel , Carvalho Rita , Alves Susana , Saraiva Sandra , Cadime Ana T.
Published: March 2017

Background: Adequate bowel preparation is one of the most important quality factors of colonoscopy. Our goal was to analyse the impact of personalised patient education on bowel cleansing preparation for colonoscopy. Methods: We performed a single-blinded, single-centre, prospective randomised trial, where patients were either allocated to a control group, where they received some predefined oral and written information on bowel preparation from the gastroenterologist, or to an intervention group, where patients received additional personalised instructions for bowel preparation and diet from a nurse. The primary outcome was the quality of bowel preparation (Aronchick scale). Results: A total of 229 patients were randomised; 113 to the control group and 116 to the intervention group. In intention-to-treat analysis, bowel preparation was adequate in 62% (95% CI 53-70) of colonoscopies in the intervention group and in 35% (95% CI 26-44) of colonoscopies in the control group (p < 0.001). The absolute risk reduction was 27%, the relative risk was 1.77, and the number needed to treat was 4. Subgroup analysis showed a significant impact of personalised education in patients under 65 years (67 vs. 35%; p < 0.001), in males (60 vs. 33%; p = 0.003), in those with higher educational levels (68 vs. 37%; p = 0.002), in those living in urban areas (68 vs. 40%; p = 0.004), and in those with previous colonoscopy (68 vs. 40%; p = 0.001). Risk factors for inadequate preparation were: male gender (OR = 2.1; 95% CI 1.1-4.1), diabetes mellitus (OR = 3.8; 95% CI 1.2-11.6), chronic constipation (OR = 3.7; 95% CI 1.7-8.2), absence of prior abdominal surgery (OR = 2.2; 95% CI 1.2-4.1), and being in the control group (OR = 2.5; 95% CI 1.4-4.4). Conclusions: Personalised patient education on bowel preparation for colonoscopy significantly improved the quality of bowel preparation.
Paraduodenal Pancreatitis: Three Cases with Different Therapeutic Approaches
Authors: Carvalho Diana , Loureiro Rafaela , Pavão Borges Verónica , Russo Pedro , Bernardes Carlos , Ramos Gonçalo
Published: March 2017

Background: Paraduodenal pancreatitis is a rare cause of chronic abdominal pain characterized by an inflammatory process and scarring in the groove area between the pancreatic head and the duodenal wall. Besides abdominal pain, symptoms such as vomiting and weight loss are common. Currently, advances in radiological and endoscopic diagnostic methods allow it to be identified without histological confirmation, although the differentiation from pancreatic adenocarcinoma could be challenging in some cases. Many therapeutic options are available nowadays including pharmacological, endoscopic, or surgical treatment. Methods: We report 3 cases of paraduodenal pancreatitis that had different therapeutic approaches. Results and Conclusion: They show that this pathology should be taken into account in the differential diagnosis of pancreatic masses with duodenal infiltration, and that its management should be individualized and judicious.
Acute Liver Failure due to Trazodone and Diazepam
Authors: Carvalhana Sofia , Oliveira Ana , Ferreira Pedro , Resende Margarida , Perdigoto Rui , Barroso Eduardo
Published: March 2017

Most antidepressant agents have the potential to cause liver injury, even at therapeutic doses. Nevertheless, drug-induced liver injury (DILI) from antidepressant agents is a rare event. There is no way to prevent idiopathic DILI, but the severity of the reaction may be minimized with prompt recognition and early withdrawal of the agent. We describe a rare case of a 63-year-old man presenting with acute liver failure after 3 months of trazodone and diazepam administration at normal therapeutic doses, requiring liver transplantation. This report should increase physicians' awareness of this complication and call attention to the regular monitoring of liver tests in patients taking trazodone, in order to prevent life-threatening complications.
Adenoma Detection Rate: I Will Show You Mine if You Show Me Yours
Authors: Oliveira Ferreira Alexandre , Fidalgo Catarina , Palmela Carolina , Costa Santos Maria Pia , Torres Joana , Nunes Joana , Loureiro Rui , Ferreira Rosa , Barjas Elídio , Glória Luísa , Santos António Alberto , Cravo Marília
Published: March 2017

Background: Colorectal cancer (CRC) is the first cause of cancer-related mortality in Portugal. CRC screening reduces disease-specific mortality. Colonoscopy is currently the preferred method for screening as it may contribute to the reduction of CRC incidence. This beneficial effect is strongly associated with the adenoma detection rate (ADR). Aim: Our aim was to evaluate the quality of colonoscopy at our unit by measuring the currently accepted quality parameters and publish them as benchmarking indicators. Methods: From 5,860 colonoscopies, 654 screening procedures (with and without previous fecal occult blood testing) were analyzed. Results: The mean age of the patients was 66.4 ± 7.8 years, and the gender distribution was 1:1. The overall ADR was 36% (95% confidence interval [CI] 32-39), the mean number of adenomas per colonoscopy was 0.66 (95% CI 0.56-0.77), and the sessile serrate lesion detection rate was 1% (95% CI 0-2). The bowel preparation was rated as adequate in 496 (76%) patients. The adjusted cecal intubation rate (CIR) was 93.7% (95% CI 91.7-95.8). Most colonoscopies were performed under monitored anesthesia care (53%), and 35% were unsedated. The use of sedation (propofol or midazolam based) was associated with a higher CIR with an odds ratio of 3.60 (95% CI 2.02-6.40, p < 0.001). Conclusion: Our data show an above-standard ADR. The frequency of poor bowel preparation and the low sessile serrated lesion detection rate were acknowledged, and actions were implemented to improve both indicators. Quality auditing in colonoscopy should be compulsory, and while many units may do so internally, this is the first national report from a high-throughput endoscopy unit.
Acute Pancreatitis Etiology Investigation: A Workup Algorithm Proposal
Authors: da Silva Sílvia , Rocha Mónica , Pinto-de-Sousa João
Published: March 2017

Background: Acute pancreatitis represents a significant number of hospital admissions. Most of the patients are admitted in an acute setting. Early identification of its etiology is an essential step toward the rational approach, both for its implications in the immediate therapy and the prevention of recurrence. Although often obvious, the etiological workup of acute pancreatitis can be challenging. Conclusion: There are several studies emphasizing the multiple etiologies underlying acute pancreatitis but lacking structured diagnostic workups to allow a rational and organized study. The main goal of this work is to develop an algorithm proposal, which aims to serve as a guide for the investigation of the etiology of acute pancreatitis based on a review of already published literature, adjusted to the reality of our hospital and the available resources.
Baveno VI Recommendation on Avoidance of Screening Endoscopy in Cirrhotic Patients: Are We There Yet?
Authors: Silva Mário Jorge , Bernardes Carlos , Pinto João , Loureiro Rafaela , Duarte Pedro , Mendes Milena , Calinas Filipe
Published: March 2017

Introduction: Recent studies assessed the predictive value of liver transient elastography, combined or not with platelet count, for the presence of esophageal varices in patients with liver cirrhosis, and multiple cutoffs have been proposed. The Baveno VI consensus states that patients with compensated advanced chronic liver disease, liver stiffness <20 kPa, and a platelet count >150,000 have a very low risk of having varices requiring treatment and can avoid screening endoscopy. We aimed to validate this recommendation in a cohort of cirrhotic patients. Methods: Retrospective analysis of all patients evaluated at the Gastroenterology Department (Centro Hospitalar de Lisboa Central) between September 2009 and October 2015 with a liver stiffness (FibroScan®) compatible with liver cirrhosis as well as upper endoscopy and blood tests within 12 months from elastography. Patients on propranolol ≥80 mg/day or carvedilol ≥12.5 mg/day, as well as those with previous variceal bleeding, variceal endoscopic treatments, or cirrhosis decompensations were excluded. We validated the new Baveno VI recommendation and explored alternative cutoffs. Results: Ninety-seven patients were analyzed, 76.3% (74/97) male, mean age 54.3 ± 11.2 years. Most patients (55.7%) had no varices and 14.4% had varices requiring treatment. Most patients (78.4%) had cirrhosis related to chronic hepatitis C. If the new Baveno VI recommendation had been applied to this cohort, upper endoscopy would have been avoided in 11.3% (11/97) of patients, none of them with esophageal varices requiring treatment: specificity 100%, sensitivity 13.3%, positive predictive value 100%, and negative predictive value 16.3% for absence of varices requiring treatment. If screening endoscopy had been avoided in those patients with liver stiffness <30 kPa and platelet count ≥120,000, endoscopy would have been avoided in 27.8% (27/97) of patients, none of whom with esophageal varices requiring treatment: specificity 100%, sensitivity 32.5%, positive predictive value 100%, and negative predictive value 20% for absence of varices requiring treatment. Conclusions: The new Baveno VI criteria identified compensated cirrhotic patients without varices requiring treatment in whom screening endoscopy could have been avoided safely. Further studies are needed to confirm these findings and potentially explore more ambitious but still safe cutoffs for those criteria.
Fistulization of J-PEG Jejunal Tube into the Colon in a Patient Treated with Duodopa® Infusion: A Case Report
Authors: Russo Pedro , Costa Mariana , Silva Mário , de Sousa Ary , Carvalho Diana , Saiote Joana , Mendes Milena
Published: March 2017

The continuous delivery of a levodopa/carbidopa gel suspension (Duodopa®) into the small bowel through a jejunal tube inserted via percutaneous endoscopic gastrostomy represents a new treatment method in advanced Parkinson disease. Some severe device-related complications have been described in the last few years. Some of them are associated with phytobezoar formation at the pigtail of the catheter. We present the case of a Parkinson disease patient treated with the Duodopa infusion system complicated by jejunal tube fistulization into the colon. We suggest a possible treatment strategy for this complication, which has not been described in the literature to date.
Diagnostic Accuracy of Controlled Attenuation Parameter for Detecting Hepatic Steatosis in Patients with Chronic Liver Disease
Authors: Andrade Patrícia , Rodrigues Susana , Rodrigues-Pinto Eduardo , Gaspar Rui , Lopes Joanne , Lopes Susana , Macedo Guilherme
Published: March 2017

Introduction: Controlled attenuation parameter (CAP), measured by transient elastography, has been suggested as a noninvasive method for the detection and quantification of steatosis. We aimed to assess the accuracy of CAP to detect steatosis in patients with chronic liver disease (CLD) compared with liver histology and to evaluate factors that correlate with the CAP value. Methods: Patients with CLD who underwent liver biopsy and simultaneous CAP determination were consecutively enrolled. CAP was measured using the M probe of FibroScan® (Echosens, Paris, France). Histologically, steatosis was categorized as absent (S0: <5%), mild (S1: 5-33%), moderate (S2: 34-66%) and severe (S3: >66% of all hepatocytes). Results: We analyzed 159 patients with CLD (61% men, mean age 47.9 ± 12.9 years). We found a positive correlation between CAP and steatosis in histology (rs = 0.869, p < 0.001), arterial hypertension (rs = 0.222, p = 0.005), type 2 diabetes mellitus (rs = 0.279, p < 0.001), body mass index (BMI; rs = 0.533, p < 0.001), total cholesterol (rs = 0.442, p < 0.001), triglycerides (rs = 0.272, p = 0.001), and non-alcoholic fatty liver disease (NAFLD; rs = 0.588, p < 0.001). In the multivariate analysis, BMI >25 (odds ratio [OR] 48.4, 95% confidence interval [CI] 23.78-72.95, p < 0.001), serum total cholesterol (OR 3.803, 95% CI 2.203-13.889, p = 0.008), and NAFLD etiology (OR 40.8, 95% CI 15.01-66.66, p = 0.002) were independently associated with higher CAP values. We did not find any significant correlation between CAP and the grade of necroinflammatory activity (rs = 0.063, p = 0.808) or fibrosis (rs = 0.071, p = 0.713) in histology and with alanine aminotransferase (rs = 0.190, p = 0.356) or aspartate aminotransferase (rs = 0.117, p = 0.142). Optimal CAP cutoff values for detecting steatosis ≥S1, ≥S2, and ≥S3 were 206.5, 232.5, and 282.5 dB/m, respectively. CAP performance was 0.822, 0.956, and 0.976 for diagnosing steatosis ≥S1, ≥S2, and ≥S3, respectively. Conclusions: CAP had an excellent diagnostic accuracy for the detection of steatosis in diverse CLD patients. A CAP value cutoff of <282.5 dB/m excludes severe steatosis ≥S3 with an accuracy of 98%.
Molecular Characteristics of Pancreatic Ductal Adenocarcinomas with High-Grade Pancreatic Intraepithelial Neoplasia (PanIN) Are Different from Those without High-Grade PanIN
Authors: Miyazaki Tetsuyuki , Ohishi Yoshihiro , Miyasaka Yoshihiro , Oda Yasunori , Aishima Shinichi , Ozono Keigo , Abe Atsushi , Nagai Eishi , Nakamura Masafumi , Oda Yoshinao
Published: March 2017

Aims: We reported that pancreatic ductal adenocarcinomas (PDACs) without high-grade pancreatic intraepithelial neoplasia (PanIN) in the vicinity had worse prognoses than PDACs with high-grade PanIN. However, the molecular characteristics of PDACs with and without high-grade PanIN have not been compared. The aim of this study is to clarify the molecular characteristics of PDACs with and without high-grade PanIN. Method and Results: We reviewed all of a consecutive series of 100 patients with PDACs and divided them into 2 groups: the PDACs with PanIN-2 or PanIN-3 in the background (the PanIN-high group, n = 60) and the PDACs without PanIN-2 or PanIN-3 in the background (the PanIN-low group, n = 40). We evaluated the p53, p16, and SMAD4 expressions in the invasive ductal carcinoma (IDC) components by immunohistochemical staining. KRAS mutation was also analyzed in 80 tumors. The PanIN-low group showed significantly more frequent “high p53 expression” and “loss of SMAD4 expression” than the PanIN-high group (p = 0.048 and p = 0.019, respectively). Loss of p16 expression was not significantly different between the groups. The rate of KRAS wild type was significantly higher in the PanIN-low group than the PanIN-high group (p = 0.024). Conclusions: Our results demonstrated that the molecular characteristics in the PDACs with high-grade PanIN were different from those in the PDACs without high-grade PanIN. PDACs without high-grade PanIN may develop via a pathway other than the PanIN-carcinoma sequence.
In Vitro Cell Death Discrimination and Screening Method by Simple and Cost-Effective Viability Analysis
Authors: Helm Katharina , Beyreis Marlena , Mayr Christian , Ritter Markus , Jakab Martin , Kiesslich Tobias , Plaetzer Kristjan
Published: March 2017

Background/Aims: For in vitro cytotoxicity testing, discrimination of apoptosis and necrosis represents valuable information. Viability analysis performed at two different time points post treatment could serve such a purpose because the dynamics of metabolic activity of apoptotic and necrotic cells is different, i.e. a more rapid decline of cellular metabolism during necrosis whereas cellular metabolism is maintained during the entire execution phase of apoptosis. This study describes a straightforward approach to distinguish apoptosis and necrosis. Methods: A431 human epidermoid carcinoma cells were treated with different concentrations/doses of actinomycin D (Act-D), 4,5,6,7-tetrabromo-2-azabenzimidazole (TBB), Ro 31-8220, H2O2 and photodynamic treatment (PDT). The resazurin viability signal was recorded at 2 and 24 hrs post treatment. Apoptosis and necrosis were verified by measuring caspase 3/7 and membrane integrity. Results: Calculation of the difference curve between the 2 and 24 hrs resazurin signals yields the following information: a positive difference signal indicates apoptosis (i.e. high metabolic activity at early time points and low signal at 24 hrs post treatment) while an early reduction of the viability signal indicates necrosis. For all treatments, this dose-dependent sequence of cellular responses could be confirmed by independent assays. Conclusion: Simple and cost-effective viability analysis provides reliable information about the dose ranges of a cytotoxic agent where apoptosis or necrosis occurs. This may serve as a starting point for further in-depth characterisation of cytotoxic treatments.
Fistula and Survival Outcomes after Fistula Creation among Predialysis Chronic Kidney Disease Stage 5 Patients
Authors: Miyamoto Masahito , Kurita Noriaki , Suemitsu Kotaro , Murakami Masaaki
Published: March 2017

Background: Most guidelines recommend the creation of arteriovenous fistula (AVF) in patients with chronic kidney disease (CKD) stage 4. However, an increasing number of studies suggest that early AVF creation leads to high rates of AVF failure and death before dialysis commencement. Only the Japanese guideline recommends AVF creation at CKD stage 5; however, no data are available regarding access-related outcomes at this stage. Method: This was a multicenter cohort study involving Japanese CKD stage 5 patients who underwent preemptive AVF creation from 2009 to 2013. The primary outcome was unnecessary AVF creation, defined as death before requiring dialysis or AVF failure before dialysis commencement. The secondary outcome was dialysis commencement. The associations with candidate predictors and the outcomes were examined. Results: A total of 303 patients were registered. Four cases of death before dialysis and 13 cases of AVF failure before dialysis commencement were observed. A total of 283 patients who advanced to dialysis were found to have functional AVFs. The cumulative incidences of unnecessary AVF creation and dialysis commencement at 1 year were 4.8 and 89.3%, respectively. Competing risk regression analyses showed that age ≥75 years (subhazard ratio [SHR] 3.12, 95% CI 1.20-8.09) and female gender (SHR 3.31, 95% CI 1.20-9.09) were associated with unnecessary AVF creation. Conclusions: A low incidence of unnecessary AVF creation was revealed among Japanese patients who received AVF at CKD stage 5. These results may help clarify the natural history of unnecessary AVF creation for other countries reformatting their guidelines regarding late vascular access creation.
Investigations on Capacitor Compensation Topologies Effects of Different Inductive Coupling Links Configurations
Authors: Jamal Norezmi , Saat Shakir , Yusmarnita Y. , Zaid Thoriq , Isa A. A. M.
Published: March 2017

This paper presents investigations on capacitor compensation topologies with different inductive coupling links for loosely coupled inductive power transfer (IPT) system. In general, the main constraint of the loosely coupled IPT system is power losses due to the large leakage inductances. Therefore, to overcome the aforementioned problem, in this work, capacitor compensation is proposed to be used by adding an external capacitor to the system. By using this approach, the resonant inductive coupling can be achieved efficiently and hence the efficiency of the system is also increased significantly. This paper analyzes the performance of two different compensation topologies, which are primary series-secondary series (SS) and primary series- secondary parallel (SP) topology. The performance of such topologies is evaluated through the experimental results at 1MHz operating frequency for different types of inductive coupling. From the results, SS topology produces a high power transfer but SP topology gives better efficiency.
Numerical Method for Power Losses Minimization of Vector-Controlled Induction Motor
Authors: Borisevich Alex
Published: March 2017

The paper devoted to energy efficiency maximizing problem of the induction motor under part-load conditions. The problem is formulated as the minimization of ohmic losses power as a function from flux-producing current in field-oriented motor operation. Control input precompensation which transforms the dynamic time-varying optimization problem to stationary one is introduced. Adjustment rule for control variable is proposed which speeds-up the method convergence in comparison with linear variation of input. Finally a new continuous-time search algorithm for solving the problem of minimizing power consumption was given. The statements on method behavior were formulated and convergence to local minimum was proved. The method verified in simulation and in hardware experimental setup.
Low Speed Estimation in Sensorless Direct Torque Controlled Induction Motor Drive Using Extended Kalman Filter
Authors: R Mini , C Saranya , Satheesh B. Hariram , M.N. Dinesh
Published: March 2017

Sensorless Direct Torque Control (DTC) is a powerful control scheme for high performance control of induction motor (IM) drives, which provides very quick dynamic response with simple structure and a decoupled control of torque and flux. The performance of the DTC drive depends greatly on the accuracy of the estimated flux components, torque and speed, using monitored stator voltages and currents. Low speed estimation is a great challenge because of the presence of transient offset, drift and domination of ohmic voltage drop.Extended Kalman filter (EKF) is a non linear adaptive filter which performs the process of finding the best estimate from the noisy data based on state space techniques and recursive algorithm. This paper mainly focuses on the accurate estimation of speed ranging from very low speed to rated speed using the equation of motion. A new state space model of the IM is developed for estimation in EKF, with load torque as an input variable and not as an estimated quantity which is the case in most previous studies. The developed algorithm is validated using MATLAB-Simulink platform for speeds ranging from low speed to rated speed at rated torque and at various torque conditions. An exhaustive analysis is carried out to validate the performance of DTC Induction motor drive especially at the low speeds. The results are promising for accurate estimation of speed ranging from low speed to rated speed using EKF.