WorldWideScience

Sample records for abbot prism chagas

  1. James Abbot McNeill Whistler: "At the Piano."

    Science.gov (United States)

    Hallenberg, Heather

    1987-01-01

    "At the Piano," an oil-on-canvas painting completed in 1859 by James Abbot McNeill Whistler, is used as the basis of a lesson designed to help junior high school students analyze the painting's mood, subject matter, and composition. (JDH)

  2. Treatment of Chagas Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Fernando A. Botoni

    2013-01-01

    Full Text Available Chagas' disease (ChD, caused by the protozoa Trypanosoma cruzi (T. cruzi, was discovered and described by the Brazilian physician Carlos Chagas in 1909. After a century of original description, trypanosomiasis still brings much misery to humanity and is classified as a neglected tropical disease prevalent in underdeveloped countries, particularly in South America. It is an increasing worldwide problem due to the number of cases in endemic areas and the migration of infected subjects to more developed regions, mainly North America and Europe. Despite its importance, chronic chagas cardiomyopathy (CCC pathophysiology is yet poorly understood, and independently of its social, clinical, and epidemiological importance, the therapeutic approach of CCC is still transposed from the knowledge acquired from other cardiomyopathies. Therefore, the objective of this review is to describe the treatment of Chagas cardiomyopathy with emphasis on its peculiarities.

  3. Geometric formula for prism deflection

    Indian Academy of Sciences (India)

    Apoorva G Wagh; Veer Chand Rakhecha

    2004-08-01

    While studying neutron deflections produced by a magnetic prism, we have stumbled upon a simple `geometric' formula. For a prism of refractive index close to unity, the deflection simply equals the product of the refractive power − 1 and the base-to-height ratio of the prism, regardless of the apex angle. The base and height of the prism are measured respectively along and perpendicular to the direction of beam propagation within the prism. The geometric formula greatly simplifies the optimisation of prism parameters to suit any specific experiment.

  4. Reflection by Porro Prisms

    Science.gov (United States)

    Greenslade, Thomas B.

    2010-04-01

    Students all know that reflection from a plane mirror produces an image that is reversed right to left and so cannot be read by anyone but Leonardo da Vinci, who kept his notes in mirror writing. A useful counter-example is the Porro prism, which produces an image that is not reversed.

  5. High precision prism scanning system

    Science.gov (United States)

    García-Torales, G.; Flores, J. L.; Muñoz, Roberto X.

    2007-03-01

    Risley prisms are commonly used in continuous scanning manner. Each prism is capable of rotating separately about a common axis at different speeds. Scanning patterns are determined by the ratios of the wedge angles, the speed and direction of rotation of both prisms. The use of this system is conceptually simple. However, mechanical action in most applications becomes a challenge often solved by the design of complex control algorithms. We propose an electronic servomotor system that controls incremental and continuous rotations of the prisms wedges by means of an auto-tuning PID control using a Adaline Neural Network Algorithm, NNA.

  6. Multibeam collimator uses prism stack

    Science.gov (United States)

    Minott, P. O.

    1981-01-01

    Optical instrument creates many divergent light beams for surveying and machine element alignment applications. Angles and refractive indices of stack of prisms are selected to divert incoming laser beam by small increments, different for each prism. Angles of emerging beams thus differ by small, precisely-controlled amounts. Instrument is nearly immune to vibration, changes in gravitational force, temperature variations, and mechanical distortion.

  7. Prism Window for Optical Alignment

    Science.gov (United States)

    Tang, Hong

    2008-01-01

    A prism window has been devised for use, with an autocollimator, in aligning optical components that are (1) required to be oriented parallel to each other and/or at a specified angle of incidence with respect to a common optical path and (2) mounted at different positions along the common optical path. The prism window can also be used to align a single optical component at a specified angle of incidence. Prism windows could be generally useful for orienting optical components in manufacture of optical instruments. "Prism window" denotes an application-specific unit comprising two beam-splitter windows that are bonded together at an angle chosen to obtain the specified angle of incidence.

  8. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  9. Control of Chagas disease vectors

    Directory of Open Access Journals (Sweden)

    Ramsey JM

    2003-01-01

    Full Text Available Most Latin American countries are making dramatic progress in controlling Chagas disease, through a series of national and international initiatives focusing on elimination of domestic populations of Triatominae, improved screening of blood donors, and clinical support and treatment of persons infected with Trypanosoma cruzi. Some countries, particularly Uruguay, Chile and Brazil, are sufficiently advanced in their programmes to initiate detailed planning of the subsequent phases of Chagas disease control, while others such as Peru, Ecuador, and Mexico, are currently applying only the initial phases of the control campaigns. In this review, we seek to provide a brief history of the campaigns as a basis for discussion of future interventions. Our aim is to relate operational needs to the underlying biological aspects that have made Chagas disease so serious in Latin America but have also revealed the epidemiological vulnerability of this disease.

  10. Transfusion-transmitted Chagas' disease.

    Science.gov (United States)

    Wendel, S

    1998-11-01

    Transfusion-transmitted Chagas' disease has been recognized since 1952. Until recently, no cases were reported outside of Latin America. However, emigration during the past 20 years expanded its transfusional geographic borders to North America. Trypanosoma cruzi-infected donors usually are asymptomatic, often for a lifetime. This situation complicates donor screening, particularly in regions where blood bank personnel are not familiar with the risk factors and natural history of this transfusion-transmitted infection. This review addresses the main aspects of epidemiology, risks of infection, clinical symptoms in donors and recipients, preventive measures, and blood donor screening to prevent transfusion-transmitted Chagas' disease.

  11. Chagas Disease: No Longer Exotic

    Centers for Disease Control (CDC) Podcasts

    2008-04-03

    This podcast is designed to inform health care providers about Chagas disease, diagnosis, and treatment and to assist in identifying infected patients.  Created: 4/3/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 4/8/2008.

  12. Enfermedad de Chagas en Nicaragua

    Directory of Open Access Journals (Sweden)

    Carlos N. Talavera - López

    2008-04-01

    Full Text Available LA ENFERMEDAD DE CHAGAS ES UN PROBLEMA DE SALUD pública en toda Latinoamérica; alrededor de 20 millones de personas están infectadas y 200 millones están en riesgo de contraer la enfermedad. En 2006, la prevalencia en Centroamérica era del 7%. Actualmente no existe vacuna contra el protozoo y el tratamiento disponible resulta, aparte de poco efectivo, muy tóxico para el paciente. Los programas de control de vectores han ayudado a reducir los índices de infestación en Latinoamérica, pero aún falta mucho por hacer. En Nicaragua, la enfermedad de Chagas está subvalorada y los trabajos publicados son muy pocos. Es necesario investigar sobre esta enfermedad en nuestro país con otro enfoque, uno que no subvalore la enfermedad y ayude a desarrollar métodos diagnósticos y posibles tratamientos. Este artículo recopila información sobre los trabajos realizados porlos grupos más importantes de investigación en Chagas de Nicaragua en cuanto a epidemiología, control vectorial, diagnóstico y caracterización molecular.

  13. Experimental Chagas' disease in dogs

    Directory of Open Access Journals (Sweden)

    Marta de Lana

    1992-03-01

    Full Text Available This paper describes the development of experimental Chagas' disease in 64 out-bred young dogs. Twenty-nine animals were inoculated with the Be-62 and 35 with Be-78 Trypanosoma cruzi strains. Twenty-six were infected with blood trypomastigotes by different inoculation routes and 38 with metacyclic trypomastigotes from the vector via the conjunctival route. Twenty of the 26 dogs infected with blood trypomastigotes were autopsied during the acute phase. Eleven died spontaneously and nine were sacrificed. Six remained alive until they died suddenly (two or were autopsied (four. Twelve of the 38 dogs infected with metacyclic trypomastigotes evolved naturally to the chronic phase and remained alive for 24-48 months. The parasitemia, clinical aspects and serology (IgM and IgG as well as electrocardiogram, hemogram and heart anatomo-histopathologic patterns of acute and chronic cardiac forms of Chagas' disease as seen in human infections, were reproduced. The most important finding is the reproductibility of diffuse fibrosing chronic chagasic cardiopathy in all dogs infected with Be-78 T. cruzi strain autopsied between the 90th and 864th days of infection. Thus, the dog can be considered as a suitable experimental model to study Chagas' disease according to the requisites of the World Health Organization (1984. Futhermore the animal is easily obtained and easy to handle and maintain in experimental laboratory conditions.

  14. Neutron forward diffraction by single crystal prisms

    Indian Academy of Sciences (India)

    Sohrab Abbas; Apoorva G Wagh; Markus Strobl; Wolfgang Treimer

    2008-11-01

    We have derived analytic expressions for the deflection as well as transmitted fraction of monochromatic neutrons forward diffracted by a single crystal prism. In the vicinity of a Bragg reflection, the neutron deflection deviates sharply from that for an amorphous prism, exhibiting three orders of magnitude greater sensitivity to the incidence angle. We have measured the variation of neutron deflection and transmission across a Bragg reflection, for several single crystal prisms. The results agree well with theory.

  15. Syphilis serology testing: a comparative study of Abbot Determine, Rapid Plasma Reagin (RPR) card test and Venereal Disease Research Laboratory (VDRL) methods.

    Science.gov (United States)

    Angue, Yakep; Yauieb, Appolonia; Mola, Glen; Duke, Trevor; Amoa, A B

    2005-01-01

    Blood from 2100 women attending the antenatal clinic of the Port Moresby General Hospital (PMGH) and the 9 Mile urban clinic of Port Moresby was tested for syphili using the laboratory-based Venereal Disease Research Laboratory (VDRL) syphilis serology test and two clinic-based syphilis tests, Abbot Determine and Abbot Syfacard-RR (Rapid Plasma Reagin (RPR) card test). The Abbot Determine and the Syfacard-R tests were compared with the VDRL test, the gold standard in this study. The validation test results of Determine versus VDRL were as follows: sensitivity 92.0%; specificity 94.6%; the predictive value of a positive test 42.6%; and the predictive value of a negative test 99.6%. The validation tests for RPR versus VDRL were as follows: sensitivity 56.3% specificity 96.5%; predictive value of a positive test 41.2%; and the predictive value of a negative test 98.1%. The RPR test costs 3.5 kina (about one US dollar) a test, the VDRL less than 1 kina a test whilst the Determine test kit costs about 5 kina a test. When laboratory time, salaries and other supplies are costed the Determine test is expected to cost relatively much less. Our recommendation is that the Determine test be made available in areas of the country where VDRL is unavailable or where logistics do not allow for test results to be available early enough to make a difference to the care of th pregnant woman and her fetus.

  16. The chronic gastrointestinal manifestations of Chagas disease

    Directory of Open Access Journals (Sweden)

    Nilce Mitiko Matsuda

    2009-01-01

    Full Text Available Chagas disease is an infectious disease caused by the protozoan Trypanosoma cruzi. The disease mainly affects the nervous system, digestive system and heart. The objective of this review is to revise the literature and summarize the main chronic gastrointestinal manifestations of Chagas disease. The chronic gastrointestinal manifestations of Chagas disease are mainly a result of enteric nervous system impairment caused by T. cruzi infection. The anatomical locations most commonly described to be affected by Chagas disease are salivary glands, esophagus, lower esophageal sphincter, stomach, small intestine, colon, gallbladder and biliary tree. Chagas disease has also been studied in association with Helicobacter pylori infection, interstitial cells of Cajal and the incidence of gastrointestinal cancer.

  17. Waveguide Prism Based on Porous Silicon

    Institute of Scientific and Technical Information of China (English)

    JIA Zhen-hong

    2004-01-01

    The fabrication of the oxidized porous silicon waveguide prism is reported by selectively electrochemical anodisation process. The direction changes of light beams in TE and TM polarization out of this waveguide prism were respectively measured,and the experimental results were analyzed.

  18. Demagnetizing effects in stacked rectangular prisms

    DEFF Research Database (Denmark)

    Christensen, Dennis; Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden;

    2011-01-01

    A numerical, magnetostatic model of the internal magnetic field of a rectangular prism is extended to the case of a stack of rectangular prisms. The model enables the calculation of the spatially resolved, three-dimensional internal field in such a stack given any magnetic state function, stack...... configuration, temperature distribution and applied magnetic field. In this paper the model is applied to the case of a stack of parallel, ferromagnetic rectangular prisms and the resulting internal field is found as a function of the orientation of the applied field, the number of prisms in the stack...... a direct impact on the design of, e.g., active magnetic regenerators made of stacked rectangular prisms in terms of optimizing the internal field....

  19. [Oral transmission of Chagas' disease].

    Science.gov (United States)

    Toso M, Alberto; Vial U, Felipe; Galanti, Norbel

    2011-02-01

    The traditional transmission pathways of Chagas' disease are vectorial, transfusional, transplacental and organ transplantation. However, oral transmission is gaining importance. The first evidence of oral transmission was reported in Brazil in 1965. Nowadays the oral route is the transmission mode in 50% of cases in the Amazon river zone. Oral infection is produced by the ingestion of infected triatomine bugs or their feces, undercooked meat from infested host animals and food contaminated with urine or anal secretion of infected marsupials. Therefore travelers to those zones should be advised about care to be taken with ingested food. In Chile, this new mode of transmission should be considered in public health policies.

  20. The Prism Plastic Calorimeter (PPC)

    CERN Multimedia

    2002-01-01

    This proposal supports two goals: \\\\ \\\\ First goal:~~Demonstrate that current, widely used plastic technologies allow to design Prism Plastic Calorimeter~(PPC) towers with a new ``liquid crystal'' type plastic called Vectra. It will be shown that this technique meets the requirements for a LHC calorimeter with warm liquids: safety, hermeticity, hadronic compensation, resolution and time response. \\\\ \\\\ Second goal:~~Describe how one can design a warm liquid calorimeter integrated into a LHC detector and to list the advantages of the PPC: low price, minimum of mechanical structures, minimum of dead space, easiness of mechanical assembly, accessibility to the electronics, possibility to recirculate the liquid. The absorber and the electronic being outside of the liquid and easily accessible, one has maximum flexibility to define them. \\\\ \\\\ The R&D program, we define here aims at showing the feasibility of these new ideas by building nine towers of twenty gaps and exposing them to electron and hadron beams.

  1. Calibration of ACS Prism Slitless Spectroscopy Modes

    CERN Document Server

    Larsen, S S; Walsh, J R

    2005-01-01

    The Advanced Camera for Surveys is equipped with three prisms in the Solar Blind (SBC) and High Resolution (HRC) Channels, which together cover the 1150 - 3500 A range, albeit at highly non-uniform spectral resolution. We present new wavelength- and flux calibrations of the SBC (PR110L and PR130L) and HRC (PR200L) prisms, based on calibration observations obtained in Cycle 13. The calibration products are available to users via the ST-ECF/aXe web pages, and can be used directly with the aXe package. We discuss our calibration strategy and some caveats specific to slitless prism spectroscopy.

  2. Portable Remote Imaging Spectrometer (PRISM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an UV-NIR (350nm to 1050 nm) portable remote imaging spectrometer (PRISM) for flight on a variety of airborne platforms with high SNR and response...

  3. OPERA: Objective Prism Enhanced Reduction Algorithms

    Science.gov (United States)

    Universidad Complutense de Madrid Astrophysics Research Group

    2015-09-01

    OPERA (Objective Prism Enhanced Reduction Algorithms) automatically analyzes astronomical images using the objective-prism (OP) technique to register thousands of low resolution spectra in large areas. It detects objects in an image, extracts one-dimensional spectra, and identifies the emission line feature. The main advantages of this method are: 1) to avoid subjectivity inherent to visual inspection used in past studies; and 2) the ability to obtain physical parameters without follow-up spectroscopy.

  4. The PRISM3D paleoenvironmental reconstruction

    OpenAIRE

    H. Dowsett; M. Robinson; Haywood, A. M.; Salzmann, U.; Hill, Daniel; L. E. Sohl; Chandler, M.; Williams, Mark; Foley, K; D. K. Stoll

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additio...

  5. Chagas disease in Andean countries

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2007-10-01

    Full Text Available The Andean Countries' Initiative (ACI for controlling Chagas disease was officially created in 1997 within the framework of the Hipolito Unanue Agreement (UNANUE between the Ministries of Health of Colombia, Ecuador, Peru, and Venezuela. Its objective was to interrupt transmission via vector and transfusion in the region, taking into account that there are 12.5 million people at risk in the four Andean countries forming the initiative in the area and around 3 million people are infected by Trypanosoma cruzi. The progress of control activities for the vector species present in the Andean sub-region, for different reasons, has been slow and control interventions have still not been installed in all geographical areas occupied by the target species. This has been partly due to lack of knowledge about these vector populations' biological characteristics, and consequent uncertainty about which are the appropriate control measures and strategies to be implemented in the region. The main vector species present important similarities in Venezuela and Colombia and in Ecuador and Northern Peru and they can be approached in a similar way throughout the whole regions, basing approaches on and adapting them to the current strategies being developed in Venezuela during the 1960s which have been progressively adopted in the Southern Cone and Central-American region. Additional measures are needed for keeping endemic areas free from Rhodnius prolixus silvatic populations, widely spread in the Orinoco region in Colombia and Venezuela. Regarding aetiological treatment, it is worth mentioning that (with the exception of Colombia none of the other countries forming the ACI have registered medicaments available for treating infected young people. There are no suitable follow-up programmes in the sub-region or for treating cases of congenital Chagas disease. An integral and integrated programme encompassing all the aspects including transmission by transfusion which

  6. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    Energy Technology Data Exchange (ETDEWEB)

    Bestetti, Reinaldo B., E-mail: rbestetti44@gmail.com; Restini, Carolina Baraldi A.; Couto, Lucélio B. [Universidade de Ribeirão Preto, Ribeirão Preto, São Paulo, SP (Brazil)

    2016-07-15

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  7. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    Directory of Open Access Journals (Sweden)

    Reinaldo B. Bestetti

    2016-01-01

    Full Text Available Abstract The scientific construction of chronic Chagas heart disease (CCHD started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  8. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    Science.gov (United States)

    Bestetti, Reinaldo B.; Restini, Carolina Baraldi A.; Couto, Lucélio B.

    2016-01-01

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas. PMID:27223644

  9. Neutron energy analysis by silicon prisms

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, J., E-mail: jennifer.schulz@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Ott, F. [Laboratoire Leon Brillouin, Bât 563 CEA Saclay, 91191 Gif sur Yvette Cedex (France); Hülsen, Ch.; Krist, Th. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2013-11-21

    Neutron energy analysing by refraction with prisms allows to measure different wavelengths at the same time thus avoiding losses due to monochromatization. We built and tested a refractive energy analysing device made from small prisms, where losses only occur due to the attenuation in the material. We measured the refraction and the transmission of MgF{sub 2} and Si prisms at the V14 reflectometer in Berlin at 4.9 Å to check their applicability. The experimentally determined linear attenuation coefficients are 0.055 cm{sup −1} for the MgF{sub 2} and 0.03 cm{sup −1} for the Si prisms. An energy analyser consisting of silicon prism layers was measured at the EROS reflectometer at the LLB in a white neutron beam. The useful wavelength band was 2.4–7.6 Å. At 6.7 Å a wavelength resolution of 5% and a transmission of 53% were achieved. The surface roughness of the prisms could be determined to be (0.011±0.006)deg.

  10. Immunosuppression and Chagas disease: a management challenge.

    Directory of Open Access Journals (Sweden)

    María-Jesús Pinazo

    Full Text Available Immunosuppression, which has become an increasingly relevant clinical condition in the last 50 years, modifies the natural history of Trypanosoma cruzi infection in most patients with Chagas disease. The main goal in this setting is to prevent the consequences of reactivation of T. cruzi infection by close monitoring. We analyze the relationship between Chagas disease and three immunosuppressant conditions, including a description of clinical cases seen at our center, a brief review of the literature, and recommendations for the management of these patients based on our experience and on the data in the literature. T. cruzi infection is considered an opportunistic parasitic infection indicative of AIDS, and clinical manifestations of reactivation are more severe than in acute Chagas disease. Parasitemia is the most important defining feature of reactivation. Treatment with benznidazole and/or nifurtimox is strongly recommended in such cases. It seems reasonable to administer trypanocidal treatment only to asymptomatic immunosuppressed patients with detectable parasitemia, and/or patients with clinically defined reactivation. Specific treatment for Chagas disease does not appear to be related to a higher incidence of neoplasms, and a direct role of T. cruzi in the etiology of neoplastic disease has not been confirmed. Systemic immunosuppressive diseases or immunosuppressants can modify the natural course of T. cruzi infection. Immunosuppressive doses of corticosteroids have not been associated with higher rates of reactivation of Chagas disease. Despite a lack of evidence-based data, treatment with benznidazole or nifurtimox should be initiated before immunosuppression where possible to reduce the risk of reactivation. Timely antiparasitic treatment with benznidazole and nifurtimox (or with posaconazole in cases of therapeutic failure has proven to be highly effective in preventing Chagas disease reactivation, even if such treatment has not been

  11. Single-lens stereovision system using a prism: position estimation of a multi-ocular prism.

    Science.gov (United States)

    Cui, Xiaoyu; Lim, Kah Bin; Zhao, Yue; Kee, Wei Loon

    2014-05-01

    In this paper, a position estimation method using a prism-based single-lens stereovision system is proposed. A multifaced prism was considered as a single optical system composed of few refractive planes. A transformation matrix which relates the coordinates of an object point to its coordinates on the image plane through the refraction of the prism was derived based on geometrical optics. A mathematical model which is able to denote the position of an arbitrary faces prism with only seven parameters is introduced. This model further extends the application of the single-lens stereovision system using a prism to other areas. Experimentation results are presented to prove the effectiveness and robustness of our proposed model.

  12. The PRISM3D paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  13. An improved prism energy analyzer for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, J., E-mail: jennifer.schulz@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Ott, F. [Laboratoire Leon Brillouin, Bât 563 CEA Saclay, 91191 Gif sur Yvette Cedex (France); Krist, Th. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2014-04-21

    The effects of two improvements of an existing neutron energy analyzer consisting of stacked silicon prism rows are presented. First we tested the effect of coating the back of the prism rows with an absorbing layer to suppress neutron scattering by total reflection and by refraction at small angles. Experiments at HZB showed that this works perfectly. Second the prism rows were bent to shift the transmitted wavelength band to larger wavelengths. At HZB we showed that bending increased the transmission of neutrons with a wavelength of 4.9 Å. Experiments with a white beam at the EROS reflectometer at LLB showed that bending of the energy analyzing device to a radius of 7.9 m allows to shift the transmitted wavelength band from 0 to 9 Å to 2 to 16 Å.

  14. Comparing Volumes of Prisms and Pyramids

    Science.gov (United States)

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  15. Prisms Throw Light on Developmental Disorders

    Science.gov (United States)

    Brookes, Rebecca L.; Nicolson, Roderick I.; Fawcett, Angela J.

    2007-01-01

    Prism adaptation, in which the participant adapts to prismatic glasses that deflect vision laterally, is a specific test of cerebellar function. Fourteen dyslexic children (mean age 13.5 years); 14 children with developmental coordination disorder (DCD): 6 of whom had comorbid dyslexia; and 12 control children matched for age and IQ underwent…

  16. Serodiagnosis of chronic Chagas infection by using EIE-Recombinant-Chagas-Biomanguinhos kit

    Directory of Open Access Journals (Sweden)

    Gomes Yara M

    2001-01-01

    Full Text Available A kit based on an enzyme immunoassay, EIE-Recombinant-Chagas-Biomanguinhos, developed by the Oswaldo Cruz Foundation, was evaluated for the serodiagnosis of chronic Chagas disease. Evaluation was performed with 368 serum samples collected from individuals living in an endemic area for Chagas disease: 131 patients in the chronic phase with confirmed clinical, epidemiological, and serological diagnosis (indirect immunofluorescence, indirect hemagglutination or enzyme-linked immunosorbent assay and 237 nonchagasic seronegative individuals were considered negative control. The EIE-Recombinant-Chagas-Biomanguinhos kit showed high sensitivity, 100% (CI 95%: 96.4-100% and high specificity, 100% (CI 95%: 98-100%. The data obtained were in full agreement with clinical and conventional serology data. In addition, no cross-reaction was observed with sera from patients with cutaneous (n=14 and visceral (n=3 leishmaniasis. However, when these sera were tested by conventional serological assays for Chagas disease, cross-reactions were detected in 14.3% and 33.3% of the patients with cutaneous and visceral leishmaniasis, respectively. No cross-reactions were observed when sera from nonchagasic seronegative patients bearing other infectious disease (syphilis, n=8; HTLV, n=8; HCV, n=7 and HBV, n=12 were tested. In addition, sera of patients with inconclusive results for Chagas disease by conventional serology showed results in agreement with clinical evaluation, when tested by the kit. These results are relevant and indicate that the refered kit provides a safe immunodiagnosis of Chagas disease and could be used in blood bank screening.

  17. Prism. Volume 1, Number 1, December 2009

    Science.gov (United States)

    2009-12-01

    Susan B. Epstein , U.S. Embassy in Iraq (Washington, DC: CRS, October 24, 2006), figure 1. 18 The “clear-hold-build” approach to counterinsurgency is...staff of other agencies, such as the Coast Guard, Central Intelligence Agency, and National Security Agency. See Edward F. Bruner, “Military Forces...Reconstruction Roles, ed. Joseph Cerami and Jay Boggs (Carlisle, PA: Strategic Studies Institute, 2007). 102 | leSSoNS leaRNed PRISM 1, no. 1 10

  18. Evaluations of 1990 PRISM design revisions

    Energy Technology Data Exchange (ETDEWEB)

    Van Tuyle, G.J.; Slovik, G.C.; Chan, B.C.; Aronson, A.L.; Kennett, R.J. [Brookhaven National Lab., Upton, NY (United States)

    1992-03-01

    Analyses of the 1990 version of the PRISM Advanced Liquid Metal Reactor (ALMR) design are presented and discussed. Most of the calculations were performed using BNL computer codes, particularly SSC and MINET. In many cases, independent BNL calculations were compared against analyses presented by General Electric when they submitted the PRISM design revisions for evaluation by the Nuclear Regulatory Commission (NRC). The current PRISM design utilizes the metallic fuel developed by Argonne National Laboratory (ANL) which facilitates the passive/``inherent`` shutdown mechanism that acts to shut down reactor power production whenever the system overheats. There are a few vulnerabilities in the passive shutdown, with the most worrisome being the positive feedback from sodium density decreases or sodium voiding. Various postulated unscrammed events were examined by GE and/or BNL, and much of the analysis discussed in this report is focused on this category of events. For the most part, the BNL evaluations confirm the information submitted by General Electric. The principal areas of concern are related to the performance of the ternary metal fuel, and may be resolved as ANL continues with its fuel development and testing program.

  19. Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation

    Directory of Open Access Journals (Sweden)

    Laure Christophe

    2016-01-01

    Full Text Available Complex Regional Pain Syndrome (CRPS is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead, and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations.

  20. Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation

    Science.gov (United States)

    Volckmann, Pierre; Jacquin-Courtois, Sophie

    2016-01-01

    Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations. PMID:27668094

  1. Chagas' Disease: an acute transfusional case report

    Directory of Open Access Journals (Sweden)

    Dalva Marli Valério Wanderley

    1988-12-01

    Full Text Available Report of a case of acute transfusional Chagas'disease in a four-year-old child with a previous diagnosis of acute lymphocytic leukemia, transmitted in São Paulo, the Capital of São Paulo State, Brazil. Epidemiological investigation disclosed the donor's serological positivity and his previous residence in an area where Chagas' disease is endemic. The importance of adequate sorological screening in blood donors is evident. It should be stressed that this is the first case notified to the Superintendência de Controle de Endemias (SUCEN (Superintendency for the Endemy Control of the State Secretariat of Health, São Paulo, for the last five years.

  2. The Southern Cone Initiative against Chagas disease.

    Science.gov (United States)

    Schofield, C J; Dias, J C

    1999-01-01

    Chagas disease (also known as American trypanosomiasis) is now ranked as the most serious parasitic disease of the Americas, with an economic impact far outranking the combined effects of other parasitic diseases such as malaria, schistosomiasis and leishmaniasis. Although the chronic infection remains virtually incurable, transmission can be halted by eliminating the domestic insect vectors and screening blood donors to avoid transfusional transmission. In line with this strategy, governments of the six Southern Cone countries (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay) launched in 1991 an ambitious initiative to control Chagas disease through elimination of the main vector, Triatoma infestans, and large-scale screening of blood donors. Now at its mid-point, the programme has achieved remarkable success, with transmission halted over vast areas of the previously endemic regions. Well over 2 million rural houses have been sprayed to eliminate T. infestans, and the programme has already shown significant economic rates of return in addition to the medical and social benefits.

  3. Ticks, ivermectin, and experimental Chagas disease

    Directory of Open Access Journals (Sweden)

    João Carlos Pinto Dias

    2005-12-01

    Full Text Available Following an infestation of dogticks in kennels housing dogs used for long-term studies of the pathogenesis of Chagas disease, we examined the effect of ivermectin treatment on the dogs, ticks, trypanosome parasites, and also on triatomine vectors of Chagas disease. Ivermectin treatment was highly effective in eliminating the ticks, but showed no apparent effect on the dogs nor on their trypanosome infection. Triatominae fed on the dogs soon after ivermectin treatment showed high mortality, but this effect quickly declined for bugs fed at successive intervals after treatment. In conclusion, although ivermectin treatment may have a transient effect on peridomestic populations of Triatominae, it is not the treatment of choice for this situation. The study also showed that although the dogticks could become infected with Trypanosoma cruzi, this only occurred when feeding on dogs in the acute phase of infection, and there was no evidence of subsequent parasite development in the ticks.

  4. [Chagas Carlos Justiniano Ribeiro (1879-1934)].

    Science.gov (United States)

    Pays, J F

    2009-12-01

    The story of the life of Carlos Chagas is closely associated with the discovery of American Human Trypanosomiasis, caused by Trypanosoma cruzi. Indeed, he worked on this for almost all of his life. Nowadays he is considered as a national hero, but, when he was alive, he was criticised more severely in his own country than elsewhere, often unjustly and motivated by jealousy, but sometimes with good reason. Cases of Chagas disease in non-endemic countries became such a concern that public health measures have had to be taken. In this article we give a short account of the scientific journey of this man, who can be said to occupy his very own place in the history of Tropical Medicine.

  5. Fatal acute Chagas Disease in a Chimpanzee

    Science.gov (United States)

    2009-08-01

    protozoan parasite belonging to the order Kinetoplastida, family Trypanosomatidae. Arthropod vectors (Reduviidae, assassin bugs or cone nosed bugs or...Laranja FS. Experimental Chagas’ disease in rhesus monkeys. I. Clinical, parasitological , hematological and anatomo- pathological studies in the acute...of infection and immunity from mother to young. Parasitology . 1972; 65:1–9. [PubMed: 4626452] 21. Miles MA, Marsden PD, Pettitt LE, Draper CC, Watson

  6. Optimized design of parallel beam-splitting prism

    Institute of Scientific and Technical Information of China (English)

    Peitao Zhao(赵培涛); Guohua Li(李国华)

    2004-01-01

    A large lateral shearing distance of parallel beam-splitting prism is often needed in laser modulation and polarization interference. In this letter, we present an optimized design of parallel beam-splitting prism and list some different cases in detail. The optimized design widens the use range of parallel beam-splitting prism. At the wavelength of 632.8 nm, the law that the enlargement ratio changes with the refractive index and the apex angle is verified.

  7. Electric Field Enhancement of Nano Gap of Silver Prisms

    Institute of Scientific and Technical Information of China (English)

    KENZO Yamaguchi; TOMOHIRO Inoue; MASAMITSU Fujii; MASANOBU Haraguchi; TOSHIHIRO Okamoto; MASUO Fukui; SHU Seki; SEIICHI Tagawa

    2007-01-01

    Using numerical calculation, we examine the effects of gap distance of a pair of nano gap silver prisms with rounded corners on the local light intensity enhancement. Two peaks due to localized surface plasmon (LSP) excitation are observed in a wavelength range from 900nm to 300nm. The results demonstrate that peaks at a longer and a shorter wavelength corresponded to dipole-like and quadrupole-like LSP resonances, respectively. It is found that a gap distance up to 20nm provides larger light intensity enhancement than that of a single silver nano prism with rounded corners. Furthermore, nano gap silver prisms are fabricated by direct focused ion beam processing, and we measure the scattering light spectrum of a pair of nano prisms by a confocal optical system.However, the two LSP peaks are not observed in visible range because the sizes of the nano gap and prisms are too large.

  8. Dobutamine Stress Echocardiography Safety in Chagas Disease Patients

    Science.gov (United States)

    Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Furtado, Rogerio Gomes; Turco, Fabio de Paula; Melato, Luciano Henrique; Hotta, Viviane Tiemi; Nunes, Colandy Godoy de Oliveira; Rassi Jr., Luiz; Rassi, Salvador

    2017-01-01

    Background A few decades ago, patients with Chagas disease were predominantly rural workers, with a low risk profile for obstructive coronary artery disease (CAD). As urbanization has increased, they became exposed to the same risk factors for CAD of uninfected individuals. Dobutamine stress echocardiography (DSE) has proven to be an important tool in CAD diagnosis. Despite being a potentially arrhythmogenic method, it is safe for coronary patients without Chagas disease. For Chagas disease patients, however, the indication of DSE in clinical practice is uncertain, because of the arrhythmogenic potential of that heart disease. Objectives To assess DSE safety in Chagas disease patients with clinical suspicion of CAD, as well as the incidence of arrhythmias and adverse events during the exam. Methods Retrospective analysis of a database of patients referred for DSE from May/2012 to February/2015. This study assessed 205 consecutive patients with Chagas disease suspected of having CAD. All of them had their serology for Chagas disease confirmed. Results Their mean age was 64±10 years and most patients were females (65.4%). No patient had significant adverse events, such as acute myocardial infarction, ventricular fibrillation, asystole, stroke, cardiac rupture and death. Regarding arrhythmias, ventricular extrasystoles occurred in 48% of patients, and non-sustained ventricular tachycardia in 7.3%. Conclusion DSE proved to be safe in this population of Chagas disease patients, in which no potentially life-threatening outcome was found. PMID:28099588

  9. Cognitive impairment in human chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    C.A. Mangone

    1994-06-01

    Full Text Available We proposed to investigate subclinical cognitive impairment secondary to chronic Chagas' disease (CCD. No similar study was previously done. The neuropsychological performance of 45 chronic Chagasic patients and 26 matched controls (age, education place and years of residency in endemic area was compared using the Mini Mental State Exam (MMSE, Weschler Memory Scale (WMS and the Weschler Adult Intelligent Scale (WAIS. Non-parametric tests and Chi2 were used to compare group means and multivariate statistics in two way frequency tables for measures of independence and association of categorical variables with the disease. Results: Chagasic patients showed lower MMSE scores (p<004, poor orientation (p<.004, and attention (p<.007. Lower WMS MQ were associated with CCD (Chi2 5.9; p<.01; Fisher test p<.02. Lower WAIS IQ were associated with CCD (Chi2 6.3, p<.01; Fisher test p<.01 being the digit symbol (p<.03, picture completion (p<.03, picture arrangement (p<.01 and object assembly (p<.03 subtests the most affected. The impairment in non-verbal reasoning, speed of information processing, problem solving, learning and sequencing observed in chronic Chagas disease patients resembles the cognitive dysfunction associated with white matter disease.

  10. Immunoregulatory networks in human Chagas disease

    Science.gov (United States)

    Dutra, Walderez O.; Menezes, Cristiane A.S.; Magalhães, Luisa M. D.; Gollob, Kenneth J.

    2014-01-01

    Summary Chagas disease, caused by the infection with Trypanosoma cruzi, is endemic in all Latin America. Due to the increase in population migration, Chagas disease has spread worldwide and is now considered a health issue not only in endemic countries. While most chronically infected individuals remain asymptomatic, approximately 30% of the patients develop a potentially deadly cardiomyopathy. The exact mechanisms that underlie the establishment and maintenance of the cardiac pathology are not clear. However, there is consistent evidence that immunoregulatory cytokines are critical for orchestrating the immune response and, thus, influence disease development or control. While the asymptomatic (indeterminate) form represents a state of balance between the host and the parasite, the establishment of the cardiac form represents the loss of this balance. Analysis of data obtained from several studies have led to the hypothesis that the indeterminate form is associated with an anti-inflammatory cytokine profile, represented by high expression of IL-10, while cardiac form is associated with a high production of IFN-gamma and TNF-alpha in relation to IL-10, leading to an inflammatory profile. Here, we discuss the immunoregulatory events that might influence disease outcome, as well as the mechanisms that influence the establishment of these complex immunoregulatory networks. PMID:24611805

  11. Chagas disease: changes in knowledge and management.

    Science.gov (United States)

    Lescure, François-Xavier; Le Loup, Guillaume; Freilij, Hector; Develoux, Michel; Paris, Luc; Brutus, Laurent; Pialoux, Gilles

    2010-08-01

    More than 100 years after the discovery of human American trypanosomiasis by Carlos Chagas, our knowledge and management of the disease are profoundly changing. Substantial progress made by disease control programmes in most endemic areas contrasts with persisting difficulties in the Gran Chaco region in South America and the recent emergence of the disease in non-endemic areas because of population movements. In terms of pathogenesis, major discoveries have been made about the life cycle and genomics of Trypanosoma cruzi, and the role of the parasite itself in the chronic phase of the disease. From a clinical perspective, a growing number of arguments have challenged the notion of an indeterminate phase, and suggest new approaches to manage patients. New methods such as standardised PCR will be necessary to ensure follow-up of this chronic infection. Although drugs for treatment of Chagas disease are limited, poorly tolerated, and not very effective, treatment indications are expanding. The results of the Benznidazole Evaluation For Interrupting Trypanosomiasis (BENEFIT) trial in 2012 will also help to inform treatment. Mobilisation of financial resources to fund research on diagnosis and randomised controlled trials of treatment are international health priorities.

  12. Active stereo vision routines using PRISM-3

    Science.gov (United States)

    Antonisse, Hendrick J.

    1992-11-01

    This paper describes work in progress on a set of visual routines and supporting capabilities implemented on the PRISM-3 real-time vision system. The routines are used in an outdoor robot retrieval task. The task requires the robot to locate a donor agent -- a Hero2000 -- which holds the object to be retrieved, to navigate to the donor, to accept the object from the donor, and return to its original location. The routines described here will form an integral part of the navigation and wide-area search tasks. Active perception is exploited to locate the donor using real-time stereo ranging directed by a pan/tilt/verge mechanism. A framework for orchestrating visual search has been implemented and is briefly described.

  13. Prisms and neglect: what have we learned?

    Science.gov (United States)

    Newport, Roger; Schenk, Thomas

    2012-05-01

    Since Rossetti et al. (1998) reported that prism adaptation (PA) can lead to a substantial reduction of neglect symptoms PA has become a hot topic in neglect-research. More than 280 articles have been published in this area. Not all of those studies investigated the therapeutic potential of this technique, many studies examined the responsiveness to PA as a way to subdivide neglect into separate subsyndromes, other studies focussed on the process of PA itself in an effort to illuminate its underlying neurobiological mechanisms. In this article we will review research in all of these three areas to determine whether and to what extent research on PA in neglect patients has fulfilled its promise as a new way to improve the treatment of neglect, enhance our understanding of this complex syndrome and provide new insights into the neurobiology of sensorimotor learning.

  14. Enfermedad de Chagas o Tripanosomiasis Americana.

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2000-08-01

    Full Text Available

    Situación Actual de Colombia.

    La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

    Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estrictamente hematófagos de la familia Reduviidae, en el momento en que perforan la piel para succionar la sangre que los alimenta.

    Sin embargo, no se inocula directamente por intermedio de las estructuras bucales del insecto en el momento de la picadura como en el caso de las tripanosomiasis africanas, si no que se deposita pasivamente en la piel a través de las heces del insecto, penetrando en el cuerpo por la herida que causa la picadura u otras abrasiones de la piel o de la mucosa. El T. cruzi, también puede transmitirse por infección congénita, por transfusión de sangre contaminada o por el transplante de órganos contaminados. El ciclo vital del parásito es largo y complejo y su desarrollo tiene varias etapas, tanto en el vector triatomineo como en el huésped vertebrado .

    La Enfermedad de Chagas constituye una amenaza permanente para casi la cuarta parte de toda la población de América Latina. Si bien la enfermedad se encuentra presente en toda América Central y del Sur, sus manifestaciones y características epidemiológicas son altamente variables entre una y otra zona endémica. Existe una gran diversidad en las tasas de prevalencia, formas de transmisión, características parasitarias, patología clínica, vectores y reservorios.

    Más que cualquier otra enfermedad parasitaria, la enfermedad de Chagas se relaciona con el desarrollo económico y social de la población: los insectos triatomineos y las enfermedades que ellos transmiten existirán mientras en

  15. Spatial compression impairs prism-adaptation in healthy individuals

    Directory of Open Access Journals (Sweden)

    Rachel J Scriven

    2013-05-01

    Full Text Available Neglect patients typically present with gross inattention to one side of space following damage to the contralateral hemisphere. While prism-adaptation is effective in ameliorating some neglect behaviours, the mechanisms involved and their relationship to neglect remain unclear. Recent studies have shown that conscious strategic control processes in prism-adaptation may be impaired in neglect patients, who are also reported to show extraordinarily long aftereffects compared to healthy participants. Determining the underlying cause of these effects may be the key to understanding therapeutic benefits. Alternative accounts suggest that reduced strategic control might result from a failure to detect prism-induced reaching errors properly either because a the size of the error is underestimated in compressed visual space or b pathologically increased error detection thresholds reduce the requirement for error correction. The purpose of this study was to model these two alternatives in healthy participants and to examine whether strategic control and subsequent aftereffects were abnormal compared to standard prism adaptation. Each participant completed three prism-adaptation procedures within a MIRAGE mediated reality environment with direction errors recorded before, during and after adaptation. During prism-adaptation, visual-feedback of the reach could be compressed, perturbed by noise or represented veridically. Compressed visual space significantly reduced strategic control and aftereffects compared to control and noise conditions. These results support recent observations in neglect patients, suggesting that a distortion of spatial representation may successfully model neglect and explain neglect performance while adapting to prisms.

  16. The noble enigma: Chagas' nominations for the Nobel Prize

    Directory of Open Access Journals (Sweden)

    Marilia Coutinho

    1999-09-01

    Full Text Available Carlos Chagas, a Brazilian physician, discovered the American trypanosomiasis in 1909. Like other remarkable discoveries of those days, his work helped to articulate the insect-vector theory and other theoretical guidelines in tropical medicine. Unlike all other discoveries, all the stages of this work were accomplished in a few months and by a single man. Chagas' discovery was widely recognized at home and abroad. He was twice nominated for the Nobel Prize - in 1913 and in 1921-, but never received the award. Evidence suggests that the reasons for this failure are related to the violent opposition that Chagas faced in Brazil. The contentions towards Chagas were related to a rejection of the meritocratic procedures that gave him prominence, as well as to local petty politics.

  17. American Trypanosomiasis (Also Known as Chagas Disease) Detailed FAQs

    Science.gov (United States)

    ... the Caribbean (for example, in Puerto Rico or Cuba). Rare vectorborne cases of Chagas disease have been ... constructed facilities (for example, air-conditioned or screened hotel rooms), are at low risk for exposure to ...

  18. American Trypanosomiasis (Also Known as Chagas Disease) Triatomine Bug FAQs

    Science.gov (United States)

    ... the blood of mammals (including humans), birds, and reptiles. Triatomine bugs live in a wide range of environmental settings, generally within close proximity to a blood host. In areas of Latin America where human Chagas disease is an important public ...

  19. Experimental Vaccines against Chagas Disease: A Journey through History

    OpenAIRE

    Olivia Rodríguez-Morales; Víctor Monteón-Padilla; Carrillo-Sánchez, Silvia C; Martha Rios-Castro; Mariana Martínez-Cruz; Alejandro Carabarin-Lima; Minerva Arce-Fonseca

    2015-01-01

    Chagas disease, or American trypanosomiasis, which is caused by the protozoan parasite Trypanosoma cruzi, is primarily a vector disease endemic in 21 Latin American countries, including Mexico. Although many vector control programs have been implemented, T. cruzi has not been eradicated. The development of an anti-T. cruzi vaccine for prophylactic and therapeutic purposes may significantly contribute to the transmission control of Chagas disease. Immune protection against experimental infecti...

  20. A Multi-disciplinary Overview of Chagas in Periurban Peru

    Directory of Open Access Journals (Sweden)

    Sarah McCune

    2010-04-01

    Full Text Available There are between 8 and 11 million cases of America Human Trypanosomiasis, commonly known as Chagas disease, in Latin America. Chagas is endemic in southern Peru, especially the Arequipa region, where it has expanded from poor, rural areas to periurban communities. This paper summarizes the findings of four studies in periurban Arequipa: on determinants of disease-vector infestation; on prevalence, spatial patterns, and risk factors of Chagas; on links between migration, settlement patterns, and disease-vector infestation; and on the relationship between discordant test results and spatially clustered transmission hotspots. These studies identified two risk factors associated with the disease: population dynamics and the urbanization of poverty. Understanding the disease within this new urban context will allow for improved public health prevention efforts and policy initiatives. Discovered in 1909 by Brazilian physician Carlos Chagas, American Human Trypanosomiasis is a chronic and potentially life-threatening illness found throughout Latin America (Moncayo, 2003. Indeed, it is estimated that there are between 8 and 11 million cases in Mexico and Central and South America (Centers for Disease Control [CDC], 2009. Chagas disease, as it is most commonly known, is endemic in southern Peru, especially in the region of Arequipa. Once thought to be limited to poor, rural areas, the disease is now appearing in the periurban communities that surround Arequipa City, the capital of the region (Cornejo del Carpio, 2003. Understanding the urbanization of Chagas disease will allow public health and medical professionals to better combat the further transmission of the disease. After providing an overview of Chagas and introducing the scope of the disease in Latin America, this paper will summarize the findings of four recent studies conducted in periurban districts in Arequipa. Ultimately, this paper seeks to identify the risk factors associated with Chagas

  1. Control of Chagas disease vectors Control de vectores de la enfermedad de Chagas

    Directory of Open Access Journals (Sweden)

    JM Ramsey

    2003-04-01

    Full Text Available Most Latin American countries are making dramatic progress in controlling Chagas disease, through a series of national and international initiatives focusing on elimination of domestic populations of Triatominae, improved screening of blood donors, and clinical support and treatment of persons infected with Trypanosoma cruzi. Some countries, particularly Uruguay, Chile and Brazil, are sufficiently advanced in their programmes to initiate detailed planning of the subsequent phases of Chagas disease control, while others such as Peru, Ecuador, and Mexico, are currently applying only the initial phases of the control campaigns. In this review, we seek to provide a brief history of the campaigns as a basis for discussion of future interventions. Our aim is to relate operational needs to the underlying biological aspects that have made Chagas disease so serious in Latin America but have also revealed the epidemiological vulnerability of this disease.La mayoría de los países en América Latina está avanzando, con pasos importantes, en las tareas de control de la enfermedad de Chagas por medio de iniciativas nacionales e internacionales enfocadas en la eliminación de poblaciones domésticas de Triatominae, en el tamizaje de la sangre de transfusión, y en el apoyo terapeútico para los casos infectados con Trypanosoma cruzi. Algunos países como Uruguay, Chile y Brasil, están ya adelantados en sus programas y en la planeación de las siguientes fases de vigilancia y control. Sin embargo, otros países como Perú, Ecuador y México se encuentran apenas en las fases iniciales de planeación de las campañas de control. Este ensayo revisa brevemente la historia de las campañas, como fundamento para entender las estrategias para intervenciones futuras. Nuestro propósito es relacionar las necesidades operacionales con los aspectos biológicos que han provocado las dimensiones de la enfermedad de Chagas en toda América Latina, y que también han

  2. Involvement of the autonomic nervous system in Chagas heart disease

    Directory of Open Access Journals (Sweden)

    Edison Reis Lopes

    1983-12-01

    Full Text Available The autonomic nervous system and especially the intracardiac autonomic nervous system is involved in Chagas' disease. Ganglionitis and periganglionitis were noted in three groups ofpatients dying with Chagas'disease: 1 Those in heart failure; 2 Those dying a sudden, non violent death and; 3 Those dying as a consequence ofaccidents or homicide. Hearts in the threegroups also revealed myocarditis and scattered involvement of intramyocardial ganglion cells as well as lesions of myelinic and unmyelinic fibers ascribable to Chagas'disease. In mice with experimentally induced Chagas' disease weobserved more intensive neuronal lesions of the cardiac ganglia in the acute phase of infection. Perhaps neuronal loss has a role in the pathogenesis of Chagas cardiomyopathy. However based on our own experience and on other data from the literature we conclude that the loss of neurones is not the main factor responsible for the manifestations exhibited by chronic chagasic patients. On the other hand the neuronal lesions may have played a role in the sudden death ofone group of patients with Chagas'disease but is difficult to explain the group of patients who did not die sudderly but instead progressed to cardiac failure.

  3. Recognizing Variable Environments The Theory of Cognitive Prism

    CERN Document Server

    Dong, Tiansi

    2012-01-01

    Normal adults do not have any difficulty in recognizing their homes. But can artificial systems do in the same way as humans? This book collects interdisciplinary evidences and presents an answer from the perspective of computing, namely, the theory of cognitive prism. To recognize an environment, an intelligent system only needs to classify objects, structures them based on the connection relation (not through measuring!), subjectively orders the objects, and compares with the target environment, whose knowledge is similarly structured. The intelligent system works, therefore, like a prism: when a beam of light (a scene) reaches (is perceived) to an optical prism (by an intelligent system), some light (objects) is reflected (are neglected), those passed through (the recognized objects) are distorted (are ordered differently). So comes the term 'cognitive prism'! Two fundamental propositions used in the theory can be informally stated as follow: an orientation relation is a kind of distance comparison relatio...

  4. k-Odd mean labeling of prism

    Directory of Open Access Journals (Sweden)

    B. Gayathri

    2015-03-01

    Full Text Available ‎A $(p‎,‎q$ graph $G$ is said to have a $k$-odd mean‎ ‎labeling $(k ge 1$ if there exists an injection $f‎ : ‎V‎ ‎to {0‎, ‎1‎, ‎2‎, ‎ldots‎, ‎2k‎ + ‎2q‎ - ‎3}$ such that the‎ ‎induced map $f^*$ defined on $E$ by $f^*(uv =‎ ‎leftlceil frac{f(u+f(v}{2}rightrceil$ is a‎ ‎bijection from $E$ to ${2k - ‎‎‎1‎, ‎2k‎ + ‎1‎, ‎2k‎ + ‎3‎, ‎ldots‎, ‎2‎ ‎k‎ + ‎2q‎ - ‎3}$‎. ‎A graph that admits $k$-odd mean‎ ‎labeling is called $k$-odd mean graph‎. ‎In this paper‎, ‎we investigate $k$-odd mean labeling of prism $C_m times‎ ‎P_n$‎.

  5. Acute Chagas disease in El Salvador 2000-2012 - Need for surveillance and control

    OpenAIRE

    Emi Sasagawa; Ana Vilma Guevara de Aguilar; Marta Alicia Hernández de Ramírez; José Eduardo Romero Chévez; Jun Nakagawa; Rafael Antonio Cedillos; Kiyoshi Kita

    2014-01-01

    Several parasitological studies carried out in El Salvador between 2000-2012 showed a higher frequency of acute cases of Chagas disease than that in other Central American countries. There is an urgent need for improved Chagas disease surveillance and vector control programs in the provinces where acute Chagas disease occurs and throughout El Salvador as a whole.

  6. Chronic Chagas disease: from basics to laboratory medicine.

    Science.gov (United States)

    Haberland, Annekathrin; Saravia, Silvia Gilka Munoz; Wallukat, Gerd; Ziebig, Reinhard; Schimke, Ingolf

    2013-02-01

    Chagas disease, caused by Trypanosoma cruzi infection, is ranked as the most serious parasitic disease in Latin America and has huge potential to become a worldwide problem, due to increasing migration, and international tourism, as well as infectant transfer by blood contact and transfusion, intrauterine transfer, and organ transplantation. Nearly 30% of chronically-infected patients become symptomatic, often with a latency of 10-30 years, developing life-threatening complications. Of those, nearly 90% develop Chagas heart disease, while the others manifest gastrointestinal disease and neuronal disorders. Besides interrupting the infection cycle and chemo therapeutic infectant elimination, starting therapy early in symptomatic patients is important for counteracting the disease. This would be essentially supported by optimized patient management, involving risk assessment, early diagnosis and monitoring of the disease and its treatment. From economic and logistic viewpoints, the tools of laboratory medicine should be especially able to guarantee this. After summarizing the basics of chronic Chagas disease, such as the epidemiological data, the pathogenetic mechanisms thought to drive symptomatic Chagas disease and also treatment options, we present tools of laboratory medicine that address patient diagnosis, risk assessment for becoming symptomatic and guidance, focusing on autoantibody estimation for risk assessment and heart marker measurement for patient guidance. In addition, increases in levels of inflammation and oxidative stress markers in chronic Chagas disease are discussed.

  7. Behavioural biology of Chagas disease vectors

    Directory of Open Access Journals (Sweden)

    Claudio Ricardo Lazzari

    2013-01-01

    Full Text Available Many arthropod species have adopted vertebrate blood as their main food source. Blood is rich in nutrients and, except for the presence of parasites, sterile. However, this food source is not freely available, nor is obtaining it devoid of risk. It circulates inside vessels hidden underneath the skin of mobile hosts that are able to defend themselves and even predate the insects that try to feed on them. Thus, the haematophagous lifestyle is associated with major morphological, physiological and behavioural adaptations that have accumulated throughout the evolutionary history of the various lineages of blood-sucking arthropods. These adaptations have significant consequences for the evolution of parasites as well as for the epidemiology of vector-transmitted diseases. In this review article, we analyse various aspects of the behaviour of triatomine bugs to illustrate how each behavioural trait represents a particular adaptation to their close association with their hosts, which may easily turn into predators. Our aim is to offer to the reader an up-to-date integrative perspective on the behaviour of Chagas disease vectors and to propose new research avenues to encourage both young and experienced colleagues to explore this aspect of triatomine biology.

  8. Differential regional immune response in Chagas disease.

    Directory of Open Access Journals (Sweden)

    Juliana de Meis

    Full Text Available Following infection, lymphocytes expand exponentially and differentiate into effector cells to control infection and coordinate the multiple effector arms of the immune response. Soon after this expansion, the majority of antigen-specific lymphocytes die, thus keeping homeostasis, and a small pool of memory cells develops, providing long-term immunity to subsequent reinfection. The extent of infection and rate of pathogen clearance are thought to determine both the magnitude of cell expansion and the homeostatic contraction to a stable number of memory cells. This straight correlation between the kinetics of T cell response and the dynamics of lymphoid tissue cell numbers is a constant feature in acute infections yielded by pathogens that are cleared during the course of response. However, the regional dynamics of the immune response mounted against pathogens that are able to establish a persistent infection remain poorly understood. Herein we discuss the differential lymphocyte dynamics in distinct central and peripheral lymphoid organs following acute infection by Trypanosoma cruzi, the causative agent of Chagas disease. While the thymus and mesenteric lymph nodes undergo a severe atrophy with massive lymphocyte depletion, the spleen and subcutaneous lymph nodes expand due to T and B cell activation/proliferation. These events are regulated by cytokines, as well as parasite-derived moieties. In this regard, identifying the molecular mechanisms underlying regional lymphocyte dynamics secondary to T. cruzi infection may hopefully contribute to the design of novel immune intervention strategies to control pathology in this infection.

  9. Reverse time migration of prism waves for salt flank delineation

    KAUST Repository

    Dai, Wei

    2013-09-22

    In this paper, we present a new reverse time migration method for imaging salt flanks with prism wave reflections. It consists of four steps: (1) migrating the seismic data with conventional RTM to give the RTM image; (2) using the RTM image as a reflectivity model to simulate source-side reflections with the Born approximation; (3) zero-lag correlation of the source-side reflection wavefields and receiver-side wavefields to produce the prism wave migration image; and (4) repeating steps 2 and 3 for the receiver-side reflections. An advantage of this method is that there is no need to pick the horizontal reflectors prior to migration of the prism waves. It also separately images the vertical structures at a different step to reduce crosstalk interference. The disadvantage of prism wave migration algorithm is that its computational cost is twice that of conventional RTM. The empirical results with a salt model suggest that prism wave migration can be an effective method for salt flank delineation in the absence of diving waves.

  10. Containment performance of S-prism under severe BDB conditions

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, C.E.; Dubberley, A.E.; Hui, M. [GE Nuclear Energy Div., San Jose, CA (United States); Iwashige, K. [Hitachi Ltd., Ibaraki (Japan)

    2001-07-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. Based on the success of the previous DOE sponsored Advanced Liquid Metal Reactor (ALMR) program GE has continued to develop and assess the technical viability and economic potential of an up-rated modular Fast Reactor called Super PRISM (S-PRISM). S-PRISM retains all of the key ALMR design features including passive reactor shutdown, passive shutdown heat removal, and passive reactor cavity cooling that were developed under an earlier DOE program. An additional feature of S-PRISM involves the use an innovative containment system that reduces the required design basis containment pressure by a factor of two through the use of a controlled venting system. The performance of this innovative containment system is evaluated and described in this paper. (author)

  11. Research on beam splitting prism in laser heterodyne interferometer

    Science.gov (United States)

    Fu, Xiu-hua; Xiong, Shi-fu; Kou, Yang; Pan, Yong-gang; Chen, Heng; Li, Zeng-yu; Zhang, Chuan-xin

    2014-08-01

    With the rapid development of optical testing technology, laser heterodyne interferometer has been used more and more widely. As the testing precision requirements continue to increase, the technical prism is an important component of heterodyne interference. The research utilizing thin film technology to improve optical performance of interferometer has been a new focus. In the article, based on the use requirements of interferometer beam splitting prism, select Ta2O5 and SiO2 as high and low refractive index materials respectively, deposit on substrate K9. With the help of TFCalc design software and Needle method, adopting electron gun evaporation and ion assisted deposition, the beam splitting prism is prepared successfully and the ratio of transmittance and reflectance for this beam splitting prism in 500~850 nm band, incident angle 45 degree is 8:2. After repeated tests, solved the difference problem of film deposition process parameters ,controlled thickness monitoring precision effectively and finally prepared the ideal beam splitting prism which is high adhesion and stable optics properties. The film the laser induced damage threshold and it meet the requirements of heterodyne interferometer for use.

  12. Prism adaptation changes the subjective proprioceptive localization of the hands.

    Science.gov (United States)

    Scarpina, Federica; Van der Stigchel, Stefan; Nijboer, Tanja Cornelia Wilhelmina; Dijkerman, Hendrik Christiaan

    2015-03-01

    Prism adaptation involves a proprioceptive, a visual and a motor component. As the existing paradigms are not able to distinguish between these three components, the contribution of the proprioceptive component remains unclear. In the current study, a proprioceptive judgement task, in the absence of motor responses, was used to investigate how prism adaptation would specifically influences the felt position of the hands in healthy participants. The task was administered before and after adaptation to left and right displacing prisms using either the left or the right hand during the adaptation procedure. The results appeared to suggest that the prisms induced a drift in the felt position of the hands, although the after-effect depended on the combination of the pointing hand and the visual deviation induced by prisms. The results are interpreted as in line with the hypothesis of an asymmetrical neural architecture of somatosensory processing. Moreover, the passive proprioception of the hand position revealed different effects of proprioceptive re-alignment compared to active pointing straight ahead: different mechanisms about how visuo-proprioceptive discrepancy is resolved were hypothesized.

  13. Stress effects in prism coupling measurements of thin polymer films

    Science.gov (United States)

    Agan, S.; Ay, F.; Kocabas, A.; Aydinli, A.

    2005-02-01

    Due to the increasingly important role of some polymers in optical waveguide technologies, precise measurement of their optical properties has become important. Typically, prism coupling to slab waveguides made of materials of interest is used to measure the relevant optical parameters. However, such measurements are often complicated by the softness of the polymer films when stress is applied to the prism to couple light into the waveguides. In this work, we have investigated the optical properties of three different polymers, polystyrene (PS), polymethyl-methacrylate (PMMA), and benzocyclobutane (BCB). For the first time, the dependence of the refractive index, film thickness, and birefringence on applied stress in these thin polymer films was determined by means of the prism coupling technique. Both symmetric trapezoid shaped and right-angle prisms were used to couple the light into the waveguides. It was found that trapezoid shaped prism coupling gives better results in these thin polymer films. The refractive index of PMMA was found to be in the range of 1.4869 up to 1.4876 for both TE and TM polarizations under the applied force, which causes a small decrease in the film thickness of up to 0.06 μm. PMMA waveguide films were found not to be birefringent. In contrast, both BCB and PS films exhibit birefringence albeit of opposing signs.

  14. PRISM: A Practical Mealtime Imaging Stereo Matcher

    Science.gov (United States)

    Nishihara, H. K.

    1984-02-01

    A fast stereo-matching algorithm designed to operate in the presence of noise is described. The algorithm has its roots in the zero-crossing theory of Marr and Poggio but does not explicitly match zero-crossing contours. While these contours are for the most part stably tied to fixed surface locations, some fraction is always perturbed significantly by system noise. Zero-crossing contour based matching algorithms tend to I- very sensitive to these local distortions and ar, prevented from operating well on signals with moderate noise levels even though a substantial amount of information may still be present. The dual representation ¬â€?regions of constant sign in the V2G convolution persist much further into the noise than does the local geometry of the zero-crossing contours that delimit them. The PRISM system was designed to test this approach. The initial design task of the implementation has been to rapidly detect obstacles in a robotics work space and determine their rough extents and heights. In this case speed and reliability are important but precision is less critical. The system uses a pair of inexpensive vidicon cameras mounted above the workspace of a PUMA robot manipulator. The digitized video signals are fed to a high speed digital convolver that applies a 322 VG operator to the images at a 106 pixel per second rate. Matching is accomplished in software on a lisp machine with individual near/far tests taking less than i3luth of a second. A 36 by 26 matrix of absolute height measurements - in mm - over a 100 pixel disparity range is produced in 30 seconds from image acquisition to final output. Three scales of resolution are used in a coarse guides fine search. Acknowledgment: This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of 'Technology Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense

  15. Prevalence of Chagas' Disease in Mulungu do Morro Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Roque Aras

    2002-05-01

    Full Text Available OBJECTIVE - The aim of this paper is to describe the prevalence of T. Cruzi infection in patients of from Mulungu do Morro, a rural tropical region of Northeastern Brazil. METHODS - A cross-sectional study was performed. After randomly selecting samples of the population, and obtaining their consents , patients completed pretested epidemiological and clinical questionnaires. Serum samples from all patients were collected and screened for the presence of T. cruzi antibodies. RESULTS - Of 694 patients examined, 174 patients (25.1% tested had a positive serology for Chagas' disease. Of the study population, 341 patients were male with 27% Chagas' disease prevalence, without a statistical difference. Illiteracy was the only variable related to T. cruzi infection in our population. CONCLUSION - In conclusion, our study points to the high prevalence of Chagas' disease among patients in Mulungu do Morro, suggesting that this region has a high frequency of infection and probably active vectorial transmission.

  16. Pathology of intracardiac nerves in experimental Chagas disease

    Directory of Open Access Journals (Sweden)

    Ribeiro Lídia Cristina Villela

    2002-01-01

    Full Text Available Severe destruction of intrinsic cardiac nerves has been reported in experimental acute Chagas myocarditis, followed by extensive regeneration during the chronic phase of the infection. To further study this subject, the sympathetic and para-sympathetic intracardiac nerves of mice infected with a virulent Trypanosoma cruzi strain were analyzed, during acute and chronic infection, by means of histological, histochemical, morphometric and electron microscopic techniques. No evidences of destructive changes were apparent. Histochemical demonstration for acetylcholinesterase and catecholamines did not reveal differences in the amount and distribution of intracardiac nerves, in mice with acute and chronic Chagas myocarditis or in non-infected controls. Mild, probably reversible ultrastructural neural changes were occasionally present, especially during acute myocarditis. Intrinsic nerves appeared as the least involved cardiac structure during the course of experimental Chagas disease in mice.

  17. Chagas Cardiomyopathy: Clinical Presentation and Management in the Americas.

    Science.gov (United States)

    Benziger, Catherine Pastorius; do Carmo, Gabriel Assis Lopes; Ribeiro, Antonio Luiz Pinho

    2017-02-01

    The initial infection of Chagas disease is typically asymptomatic, but approximately 30% of people will progress to a chronic cardiac form, and others develop the gastrointestinal form. Death is often sudden due to arrhythmias or progressive heart failure. Prevention through vector control programs and blood bank screening, along with strengthened surveillance systems and rapid information sharing, are key to decreasing disease burden globally. The epidemiology, diagnostic evaluation, diagnosis, and treatment of acute and chronic Chagas cardiac disease are discussed with focus on educating the primary care professionals and general cardiologists in nonendemic areas who have limited experience treating this disease.

  18. Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism

    Directory of Open Access Journals (Sweden)

    Yongning Liu

    2016-02-01

    Full Text Available A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA of 5.8 × 10−8 W·cm−1·Hz−1/2 was achieved for water vapor detection in the atmosphere.

  19. Interpretation of the Faust equation for a conventional refracting prism

    Science.gov (United States)

    Tewari, R. D.; Ghodgaonkar, A. M.; Gokhale, V. D.

    1995-10-01

    The Faust formula for a conventional refracting prism is interpreted in terms of the angle of incidence ( i1) and the angle of deviation (δ). Three new possibilities emerge, namely: (a) keeping the angle of incidence ( i1) constant and varying the angle of deviation (δ); (b) keeping the angle of deviation constant and varying the angle of incidence ( i1); (c) modification of the closed forms of Murty's expression and its equivalence to (b). Using paraxial approximation and keeping the angle of incidence ( i1) and angle of deviation (δ) constant we obtain a relation between the refractive index and the base length ( b) of a prism and, in principle, this is equivalent to the Marcuse variation for optical fibres. The condition for a Littrow prism, as well as for polarized radiation is derived. An expression to estimate the spectral bandwidth (SBW) of the instrument is also derived. Experimental values of refractive index at different wavelengths are within confidence limits.

  20. The PRISM4 (mid-Piacenzian) Palaeoenvironmental Reconstruction

    Science.gov (United States)

    Dowsett, Harry; Dolan, Aisling; Rowley, David; Moucha, Robert; Forte, Alessandro M.; Mitrovica, Jerry X.; Pound, Matthew; Salzmann, Ulrich; Robinson, Marci; Chandler, Mark; Foley, Kevin; Haywood, Alan

    2016-01-01

    The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian (approximately 3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

  1. The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Moucha, Robert; Forte, Alessandro; Mitrovica, Jerry X.; Pound, Matthew; Salzmann, Ulrich; Robinson, Marci M.; Chandler, Mark; Foley, Kevin M.; Haywood, Alan M.

    2016-01-01

    The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian ( ∼ 3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

  2. Polarization properties of retroreflecting right-angle prisms.

    Science.gov (United States)

    Azzam, R M A; Khanfar, H K

    2008-01-20

    The cumulative retardance Delta(t) introduced between the p and the s orthogonal linear polarizations after two successive total internal reflections (TIRs) inside a right-angle prism at complementary angles phi and 90 degrees - phi is calculated as a function of phi and prism refractive index n. Quarter-wave retardation (QWR) is obtained on retroreflection with minimum angular sensitivity when n=(sqr rt 2+1)(1/2)=1.55377 and phi =45 degrees. A QWR prism made of N-BAK4 Schott glass (n=1.55377 at lambda=1303.5 nm) has good spectral response (<5 degrees retardance error) over the 0.5-2 microm visible and near-IR spectral range. A ZnS-coated right-angle Si prism achieves QWR with an error of < +/- 2.5 degrees in the 9-11 microm (CO(2) laser) IR spectral range. This device functions as a linear-to-circular polarization transformer and can be tuned to exact QWR at any desired wavelength (within a given range) by tilting the prism by a small angle around phi =45 degrees. A PbTe right-angle prism introduces near-half-wave retardation (near-HWR) with a < or =2% error over a broad (4< or =lambda< or =12.5 microm) IR spectral range. This device also has a wide field of view and its interesting polarization properties are discussed. A compact (aspect ratio of 2), in-line, HWR is described that uses a chevron dual Fresnel rhomb with four TIRs at the same angle phi =45 degrees. Finally, a useful algorithm is presented that transforms a three-term Sellmeier dispersion relation of a transparent optical material to an equivalent cubic equation that can be solved for the wavelengths at which the refractive index assumes any desired value.

  3. Aspectos neurológicos da moléstia de chagas Neurological aspects of Chagas disease

    Directory of Open Access Journals (Sweden)

    Fritz Köberle

    1967-09-01

    Full Text Available Carlos Chagas related in more than two 200 cases, what he called "nervous forms" of trypanosomiasis, that is neurological manifestations from central origin (idiotism, infantilism, pseudo-bulbar paralysis, aphasia, cerebellar ataxia, atetosis, espostic or paralytic diplegia, disbasia. At that time Chagas expressed his concepts as follows: "In relation to the frequency of trypanosomiasis nervous forms we have performed many observations which allow us to state that this disease is the one which causes the largest number of organic affections of the central nervous system, in human pathology". We are plenty convinced by Chagas's statement. By experiments on animals of laboratory we have very often noticed a rather varied neurological symptomatology, being worth point out identical syndromes to those observed by Chagas. Our autopsy material non-rarely include chronic Chagas cases presenting a most varied symtomatology. Among them we have named only three cases of discerebral nanism, a rather rare affection in other parts of the world and relatively frequent in our material. The fact which we have demonstrated, i.e., a relatively great decreasing of number of nervous cells in the peripheral system could happen in the central nervous system as well. Provided that there are only two quantitative works on neuron number diminishing in the central nervous system in mice and rats we decline to go into further details about central neuropathies in man. We emphasized the necessity to perform researches on this field by means of intimate collaboration between clinicians and pathologists, as the only way to confirm on scientific basis all that was observed by the panoramic and genial vision of Carlos Chagas.

  4. Transmission and Distribution of Optical Field in Prism Coupler

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C Q; Chen, M [College of Physics and Electronics Information, Hunan Institute of Science and Technology, Yueyang 414006 (China); Liu, J; Wan, Z M; Luo, Z M [College of Information and Communication Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Tian, P, E-mail: namecqh@yahoo.com.cn [College of Optoelectronic Science and Engineering, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2011-02-01

    Transmission and distribution characteristics of optical field in prism coupler are studies, and the phase matching function of prism coupler is deduced based on coupled wave theory. It is shown that the stable light field distribution and mode pattern are determined by its own geometric and dielectric parameters, but have nothing to do with the categories of incident light sources. It is also found that the coupling effect would generate between waveguides through evanescent field. Our numerical simulation is based on the finite difference time domain method with perfectly matched layer absorbing boundary condition. The simulation program is compiled in MATLAB. The simulation results are analyzed carefully.

  5. Enfermedad de Chagas congenita en la Ciudad de Salta, Argentina Congenital Chagas' disease in Salta, Argentina

    Directory of Open Access Journals (Sweden)

    Mario Zaidenberg

    1993-02-01

    Full Text Available Se estudió la respuesta clínica y serológica a la infección chagásica de 937 embarazadas y sus 929 recién nacidos (RN vivos, grupo I; 4 RN de origen diverso, grupo II y 35 RN derivados de otros centros, grupo III. Las embarazadas se estudiaron con 3 reacciones serológicas; se definió infección cuando 2 o más reacciones eran positivas. En los RN el diagnóstico se confirmó por observación directa del T. cruzi en una muestra de sangre. Los RN con Chagas congénita (RN-ChC fueron tratados y seguidos con estudios clínicos y de laboratorio. Se detectaron 149 embarazadas chagásicas (15.9%, de las cuales se diagnosticaron 6 RN-ChC (4%. En el total de 968 RN estudiados se detectaron 12 RN infectados. El micro-hematócrito fue el método parasitológico de lectura rápida más efectivo para el diagnóstico de infección en nuestra serie. El par de reacciones serológicas específicas constituyó un criterio de mayor seguridad para el control y seguimiento de la infección congénita. Las expresiones clínicas más comunes de infección fueron hepatomegalia, esplenomegalia, ictericia, anemia y prematurez, con distintos grados de asociación. Se concluye que dadas las características clínicas de la enfermedad de Chagas congénita en nuestro medio, se impone como estrategia el diagnóstico serológico para la enfermedad de Chagas en todas las embarazadas y el control y seguimiento de sus RN hasta descartar o confirmar infección congénita.The immune response to Trypanosoma cruzi was studied in our hospital in 937 pregnant women (PW and their 929 newborns (NB, group I; 4 NB from this center not included in the first group, group II and 35 NB derived from other centers, group III. Two positive results among indirect hemagglutination (IHA, complement fixation (CF and indirect hemagglutination (IHA, complement fixation (CF and indirect immunofluorescence (IIF tests were considered as the criterion of previous infection with T. cruzi in PW. The

  6. Experimental Vaccines against Chagas Disease: A Journey through History.

    Science.gov (United States)

    Rodríguez-Morales, Olivia; Monteón-Padilla, Víctor; Carrillo-Sánchez, Silvia C; Rios-Castro, Martha; Martínez-Cruz, Mariana; Carabarin-Lima, Alejandro; Arce-Fonseca, Minerva

    2015-01-01

    Chagas disease, or American trypanosomiasis, which is caused by the protozoan parasite Trypanosoma cruzi, is primarily a vector disease endemic in 21 Latin American countries, including Mexico. Although many vector control programs have been implemented, T. cruzi has not been eradicated. The development of an anti-T. cruzi vaccine for prophylactic and therapeutic purposes may significantly contribute to the transmission control of Chagas disease. Immune protection against experimental infection with T. cruzi has been studied since the second decade of the last century, and many types of immunogens have been used subsequently, such as killed or attenuated parasites and new DNA vaccines. This primary prevention strategy appears feasible, effective, safe, and inexpensive, although problems remain. The objective of this review is to summarize the research efforts about the development of vaccines against Chagas disease worldwide. A thorough literature review was conducted by searching PubMed with the terms "Chagas disease" and "American trypanosomiasis" together with "vaccines" or "immunization". In addition, reports and journals not cited in PubMed were identified. Publications in English, Spanish, and Portuguese were reviewed.

  7. Experimental Vaccines against Chagas Disease: A Journey through History

    Directory of Open Access Journals (Sweden)

    Olivia Rodríguez-Morales

    2015-01-01

    Full Text Available Chagas disease, or American trypanosomiasis, which is caused by the protozoan parasite Trypanosoma cruzi, is primarily a vector disease endemic in 21 Latin American countries, including Mexico. Although many vector control programs have been implemented, T. cruzi has not been eradicated. The development of an anti-T. cruzi vaccine for prophylactic and therapeutic purposes may significantly contribute to the transmission control of Chagas disease. Immune protection against experimental infection with T. cruzi has been studied since the second decade of the last century, and many types of immunogens have been used subsequently, such as killed or attenuated parasites and new DNA vaccines. This primary prevention strategy appears feasible, effective, safe, and inexpensive, although problems remain. The objective of this review is to summarize the research efforts about the development of vaccines against Chagas disease worldwide. A thorough literature review was conducted by searching PubMed with the terms “Chagas disease” and “American trypanosomiasis” together with “vaccines” or “immunization”. In addition, reports and journals not cited in PubMed were identified. Publications in English, Spanish, and Portuguese were reviewed.

  8. Chagas cardiomyopathy in the context of the chronic disease transition.

    Directory of Open Access Journals (Sweden)

    Alicia I Hidron

    Full Text Available BACKGROUND: Patients with Chagas disease have migrated to cities, where obesity, hypertension and other cardiac risk factors are common. METHODOLOGY/PRINCIPAL FINDINGS: The study included adult patients evaluated by the cardiology service in a public hospital in Santa Cruz, Bolivia. Data included risk factors for T. cruzi infection, medical history, physical examination, electrocardiogram, echocardiogram, and contact 9 months after initial data collection to ascertain mortality. Serology and PCR for Trypanosoma cruzi were performed. Of 394 participants, 251 (64% had confirmed T. cruzi infection by serology. Among seropositive participants, 109 (43% had positive results by conventional PCR; of these, 89 (82% also had positive results by real time PCR. There was a high prevalence of hypertension (64% and overweight (body mass index [BMI] >25; 67%, with no difference by T. cruzi infection status. Nearly 60% of symptomatic congestive heart failure was attributed to Chagas cardiomyopathy; mortality was also higher for seropositive than seronegative patients (p = 0.05. In multivariable models, longer residence in an endemic province, residence in a rural area and poor housing conditions were associated with T. cruzi infection. Male sex, increasing age and poor housing were independent predictors of Chagas cardiomyopathy severity. Males and participants with BMI Chagas cardiomyopathy remains an important cause of congestive heart failure in this hospital population, and should be evaluated in the context of the epidemiological transition that has increased risk of obesity, hypertension and chronic cardiovascular disease.

  9. Chagas disease: control, elimination and eradication. Is it possible?

    Directory of Open Access Journals (Sweden)

    Jose Rodrigues Coura

    2013-12-01

    Full Text Available From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA to southern Argentina and Chile (42ºN 49ºS, (ii anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra, Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by

  10. Budding Architects: Exploring the Designs of Pyramids and Prisms

    Science.gov (United States)

    Leavy, Aisling; Hourigan, Mairéad

    2015-01-01

    The context of students as architects is used to examine the similarities and differences between prisms and pyramids. Leavy and Hourigan use the Van Hiele Model as a tool to support teachers to develop expectations for differentiating geometry in the classroom using practical examples.

  11. THz Photonic Band-Gap Prisms Fabricated by Fiber Drawing

    DEFF Research Database (Denmark)

    Busch, Stefan F.; Xu, Lipeng; Stecher, Matthias;

    2012-01-01

    We suggest a novel form of polymeric based 3D photonic crystal prisms for THz frequencies which could be fabricated using a standard fiber drawing technique. The structures are modeled and designed using a finite element analyzing technique. Using this simulation software we theoretically study...

  12. Prism adaptation changes the subjective proprioceptive localization of the hands

    NARCIS (Netherlands)

    Scarpina, Federica; Van Der Stigchel, Stefan|info:eu-repo/dai/nl/29880977X; Nijboer, Tanja Cornelia Wilhelmina|info:eu-repo/dai/nl/304832421; Dijkerman, Hendrik Christiaan|info:eu-repo/dai/nl/304829757

    2015-01-01

    Prism adaptation involves a proprioceptive, a visual and a motor component. As the existing paradigms are not able to distinguish between these three components, the contribution of the proprioceptive component remains unclear. In the current study, a proprioceptive judgement task, in the absence of

  13. Prism adaptation improves postural imbalance in neglect patients

    NARCIS (Netherlands)

    Nijboer, Tanja C W; Olthoff, Liselot; Van der Stigchel, Stefan; Visser-Meily, Johanna M a

    2014-01-01

    Several studies have found a negative relation between neglect and postural imbalance. The aim of the current study was to investigate the influence of a single session of prism adaptation on balance [i.e. mediolateral and anteroposterior center of pressure (CoP)] and postural sway (i.e. mean varian

  14. A Precision Variable, Double Prism Attenuator for CO(2) Lasers.

    Science.gov (United States)

    Oseki, T; Saito, S

    1971-01-01

    A precision, double prism attenuator for CO(2) lasers, calibrated by its gap capacitance, was constructed to evaluate its possible use as a standard for attenuation measurements. It was found that the accuracy was about 0.1 dB with a dynamic range of about 40 dB.

  15. Simple Method For Testing Of The 90° Angle Of A Reflecting Prism

    Science.gov (United States)

    Ghodgaonkar, A. M.; Tiwari, R. D.; Ramani, K.

    1982-12-01

    A simple method for testing the 90° angle of a reflecting prism by placing two prisms in contact with one another on a standard test plate and counting the number of fringes is outlined. An angle accuracy of less than a second for the angle of a 90° reflecting prism has been obtained.

  16. Phase boundary of the hexagonal-prism superconducting network in a magnetic field

    Institute of Scientific and Technical Information of China (English)

    金绍维; 李伟; 易佑民; 甄胜来; 缪胜清

    2002-01-01

    In this paper, we systematically study the phase boundary Tc(H ) of a hexagonal-prism superconducting network inan external magnetic field H of arbitrary magnitude and direction. The result indicates that the phase boundary of thehexagonal-prism superconducting circuit varies more sharply than that of the cubic circuit. The potential applicationsof the hexagonal-prism superconducting circuit are also discussed.

  17. Study of dose calculation on breast brachytherapy using prism TPS

    Energy Technology Data Exchange (ETDEWEB)

    Fendriani, Yoza; Haryanto, Freddy [Nuclear Physics and Biophysics Research Division, FMIPA Institut Teknologi Bandung, Physics Buildings, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    PRISM is one of non-commercial Treatment Planning System (TPS) and is developed at the University of Washington. In Indonesia, many cancer hospitals use expensive commercial TPS. This study aims to investigate Prism TPS which been applied to the dose distribution of brachytherapy by taking into account the effect of source position and inhomogeneities. The results will be applicable for clinical Treatment Planning System. Dose calculation has been implemented for water phantom and CT scan images of breast cancer using point source and line source. This study used point source and line source and divided into two cases. On the first case, Ir-192 seed source is located at the center of treatment volume. On the second case, the source position is gradually changed. The dose calculation of every case performed on a homogeneous and inhomogeneous phantom with dimension 20 × 20 × 20 cm{sup 3}. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm{sup 3}. The results of dose calculations using PRISM TPS were compared to literature data. From the calculation of PRISM TPS, dose rates show good agreement with Plato TPS and other study as published by Ramdhani. No deviations greater than ±4% for all case. Dose calculation in inhomogeneous and homogenous cases show similar result. This results indicate that Prism TPS is good in dose calculation of brachytherapy but not sensitive for inhomogeneities. Thus, the dose calculation parameters developed in this study were found to be applicable for clinical treatment planning of brachytherapy.

  18. O gênero Schizotrypanum Chagas, 1909

    Directory of Open Access Journals (Sweden)

    Emmanuel Dias

    1939-01-01

    Full Text Available No presente trabalho, em que foram analisados os caractéres de Schizotrypanum e consideradas suas relações com os de outros flagelados digenéticos, acreditamos ter ficado bem demonstrado que este gênero encontra sólidos fundamentos em que se baseie. Schizotrypanum possue caractéres morfológicos peculiares, que o aproximam de Leishmania no periodo de multiplicação e de Trypanosoma na fase sanguinea. Os flagelados pertencentes a esse gênero caracterisam-se não só pela morfologia da fórma de tripanosoma, como pela evolução no organismo do vertebrado. No S. cruzi, como no S. vespertilionis, a multiplicação se processa nos tecidos, constando da divisão binaria das formas intracelulares de leishmania; os tripanosomas sanguicolas não se multiplicam. Nenhum Trypanosoma apresenta no mamífero uma evolução morfológicamente e ecológicamente identica á de Schizotrypanum. S. cruzi aproxima-se dos tripanosomas patogenicos pela morfologia da fórma sanguicola e pela virulencia ás vezes mortal para o homem e diversos animais; deles se afasta entretanto pela evolução no inséto, modo de transmissão e facil cultivabilidade, caractéres biológicos estes que são comuns aos tripanosomas não patogenicos. Em nenhum dos grupos de tripanosomas póde o S. cruzi ser rigorosamente incluido, deles se distinguindo facilmente seja por sua morfologia, seja por sua biologia. O conjunto de caractéres próprios fundamenta perfeitamente a manutenção do gênero de Chagas, indicando-lhe como situação mais adequada, na classificação dos tripanosomídeos de mamíferos, o logar intermediario entre Leishmania e Trypanosoma. A separação do gênero Schizotrypanum é o melhor caso, quiça o unico justificado, dentre as numerosas tentativas para o desmembramento de Trypanosoma. Ela se impõe como medida compreensiva e util para a coordenação dos membros da complexa familia dos tripanosomideos e se justifica á luz dos mais exigentes crit

  19. Justice where justice is due: A posthumous Nobel Prize to Carlos Chagas (1879-1934), the discoverer of American Trypanosomiasis (Chagas' disease).

    Science.gov (United States)

    Bestetti, Reinaldo B; Martins, Cláudia A; Cardinalli-Neto, Augusto

    2009-05-01

    Working in the Brazilian backland, Chagas described a new disease. He discovered the etiologic agent, the vector, the reservoir, the acute stage, the several clinical aspects of the chronic stage (particularly the heart disease), role of autoimmunity in its pathogenesis, and anticipated the social impact of the disease. Chagas was nominated to Nobel Prize twice: in 1913, and in 1921. In 1913, Richet won the prize because his work on anaphylaxis. In 1921, no one received the Nobel Prize. It is believed that detraction of Chagas' work at the National Academy of Medicine, made by jealousy, mediocrity, and political rivalries can be maculated the image of the scientist. Furthermore, misperception of Chagas' work may also have led the Nobel Committee not to award him. One-hundred years after the discovery, we can appreciate the greatness of the discovery of Carlos Chagas, never seem in the realm of biological research. Time to make justice, therefore, has finally come.

  20. A case of megacolon in Rio Grande Valley as a possible case of Chagas disease

    Directory of Open Access Journals (Sweden)

    Karl Reinhard

    2003-01-01

    Full Text Available We have been searching for evidence of Chagas disease in mummified human remains. Specifically, we have looked for evidence of alteration of intestinal or fecal morphology consistent with megacolon, a condition associated with Chagas disease. One prehistoric individual recovered from the Chihuahuan Desert near the Rio Grande exhibits such pathology. We present documentation of this case. We are certain that this individual presents a profoundly altered large intestinal tract and we suggest that further research should focus on confirmation of a diagnosis of Chagas disease. We propose that the prehistoric activity and dietary patterns in Chihuahua Desert hunter/gatherers promoted the pathoecology of Chagas disease.

  1. Standard Practice for Inspection of Transparent Parts by Prism

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 Aerospace transparencies undergo high stresses induced by flight, environmental, or other factors. The transparency attachment points are especially subject to fatigue. These areas of fatigue are often obstructed or hidden from normal inspection. An inspector, following the techniques described in this practice, shall use a prism to view damage located near transparency bolt holes, voids, and delamination that are hidden by edge strips or frames. 1.2 The purpose of this practice is to provide acceptable methods for performing prism inspections of transparent materials with specific emphasis on aircraft windscreens and canopies. Caveats and lessons learned from experience are included to assist authors in writing tailored inspection instructions for specific applications. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicab...

  2. Hyperbolic prisms and foams in Hele-Shaw cells

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil); Tufaile, A.P.B. [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil)

    2011-10-03

    The propagation of light in foams creates patterns which are generated due to the reflection and refraction of light. One of these patterns is observed by the formation of multiple mirror images inside liquid bridges in a layer of bubbles in a Hele-Shaw cell. We are presenting the existence of these patterns in foams and their relation with hyperbolic geometry and Sierpinski gaskets using the Poincare disk model. The images obtained from the experiment in foams are compared to the case of hyperbolic optical elements. -- Highlights: → The chaotic scattering of light in foams generating deltoid patterns is based on hyperbolic geometry. → The deltoid patterns are obtained through the Plateau borders in a Hele-Shaw cell. → The Plateau borders act like hyperbolic prism. → Some effects of the refraction and reflection of the light rays were studied using a hyperbolic prism.

  3. [Representations, myths, and behaviors among Chagas disease patients with pacemakers].

    Science.gov (United States)

    Magnani, Claudia; Oliveira, Bruna Guimarães; Gontijo, Eliane Dias

    2007-07-01

    This anthropological study aimed to evaluate the incorporation of pacemakers into the lives of individuals with Chagas disease. An ethnographic methodology was used, based on an open interview focusing on the personal perceptions of 15 patients with chronic Chagas cardiopathy who had required pacemaker implants at the Federal University Hospital in Belo Horizonte, Minas Gerais State, Brazil. As part of a broader quality of life analysis, the study investigated the cultural, physical, and psychological resources used by patients to confront, explain, and accept the disease process, including mental representations on the cultural perception of the illness and definition of social relations. The study was intended to contribute to comprehensive patient care by health professionals, including psychosocial aspects. Decoded and integrated orientation in the cultural sphere assumes an important role in order to prevent disinformation from perpetuating the dissemination of popular myths as active elements in patient stigmatization.

  4. Prism therapy and visual rehabilitation in homonymous visual field loss.

    LENUS (Irish Health Repository)

    O'Neill, Evelyn C

    2011-02-01

    Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment.

  5. Prism therapy and visual rehabilitation in homonymous visual field loss.

    LENUS (Irish Health Repository)

    O'Neill, Evelyn C

    2012-02-01

    PURPOSE: Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment. METHODS: Twelve patients with acquired, documented HVFD were eligible to be included. All patients underwent specific vision-targeted, health-related QOL questionnaire and monocular and binocular Goldmann perimetry before commencing prism therapy. Patients were fitted with monocular prisms on the side of the HVFD with the base-in the direction of the field defect creating a peripheral optical exotropia and field expansion. After the treatment period, QOL questionnaires and perimetry were repeated. RESULTS: Twelve patients were included in the treatment group, 10 of whom were included in data analysis. Overall, there was significant improvement within multiple vision-related, QOL functioning parameters, specifically within the domains of general health (p < 0.01), general vision (p < 0.05), distance vision (p < 0.01), peripheral vision (p < 0.05), role difficulties (p < 0.05), dependency (p < 0.05), and social functioning (p < 0.05). Visual field expansion was shown when measured monocularly and binocularly during the study period in comparison with pretreatment baselines. CONCLUSIONS: Patients with HVFD demonstrate decreased QOL. Monocular sector prisms can improve the QOL and expand the visual field in these patients.

  6. PRISM: Recovery of the primordial spectrum from Planck data

    CERN Document Server

    Lanusse, F; Starck, J -L; Sureau, F; Bobin, J

    2014-01-01

    The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this letter, using our recently published PRISM algorithm, we recover the primordial power spectrum from Planck PR1 dataset. PRISM is a sparsity-based inversion method, which aims at recovering features in the primordial power spectrum from the empirical power spectrum of the Cosmic Microwave Background (CMB). The ill-posed inverse problem involved is regularised using a sparsity prior on features in the primordial power spectrum in a wavelet dictionary. Although this non-parametric method does not assume a strong prior on the shape of the primordial power spectrum, it is able to recover both its global shape and localised features. As a results, this approach presents a robust way of detecting deviations from the currently favoured scale-invariant spectrum. We apply PRISM to 100 Planck simulated data to...

  7. Chagas Cardiomyopathy in the Context of the Chronic Disease Transition

    Science.gov (United States)

    Hidron, Alicia I.; Gilman, Robert H.; Justiniano, Juan; Blackstock, Anna J.; LaFuente, Carlos; Selum, Walter; Calderon, Martiza; Verastegui, Manuela; Ferrufino, Lisbeth; Valencia, Eduardo; Tornheim, Jeffrey A.; O'Neal, Seth; Comer, Robert; Galdos-Cardenas, Gerson; Bern, Caryn

    2010-01-01

    Background Patients with Chagas disease have migrated to cities, where obesity, hypertension and other cardiac risk factors are common. Methodology/Principal Findings The study included adult patients evaluated by the cardiology service in a public hospital in Santa Cruz, Bolivia. Data included risk factors for T. cruzi infection, medical history, physical examination, electrocardiogram, echocardiogram, and contact 9 months after initial data collection to ascertain mortality. Serology and PCR for Trypanosoma cruzi were performed. Of 394 participants, 251 (64%) had confirmed T. cruzi infection by serology. Among seropositive participants, 109 (43%) had positive results by conventional PCR; of these, 89 (82%) also had positive results by real time PCR. There was a high prevalence of hypertension (64%) and overweight (body mass index [BMI] >25; 67%), with no difference by T. cruzi infection status. Nearly 60% of symptomatic congestive heart failure was attributed to Chagas cardiomyopathy; mortality was also higher for seropositive than seronegative patients (p = 0.05). In multivariable models, longer residence in an endemic province, residence in a rural area and poor housing conditions were associated with T. cruzi infection. Male sex, increasing age and poor housing were independent predictors of Chagas cardiomyopathy severity. Males and participants with BMI ≤25 had significantly higher likelihood of positive PCR results compared to females or overweight participants. Conclusions Chagas cardiomyopathy remains an important cause of congestive heart failure in this hospital population, and should be evaluated in the context of the epidemiological transition that has increased risk of obesity, hypertension and chronic cardiovascular disease. PMID:20502520

  8. Methodological advances in drug discovery for Chagas disease

    Science.gov (United States)

    Bustamante, Juan M.; Tarleton, Rick L.

    2011-01-01

    Introduction Chagas disease is the highest impact human infectious disease in Latin America, and the leading worldwide cause of myocarditis. Despite the availability of several compounds that have demonstrated efficacy in limiting the effects of T. cruzi, these compounds are rarely used due to their variable efficacy, substantial side effects and the lack of methodologies for confirming their effectiveness. Furthermore, the development of more efficacious compounds is challenged by limitations of systems for assessing drug efficacy in vitro and in vivo. Areas covered Herein, the authors review the development of Chagas disease drug discovery methodology, focusing on recent developments in high throughput screening, in vivo testing methods and assessments of efficacy in humans. Particularly, this review documents the significant progress that has taken place over the last 5 years that have paved the way for both target-focused and high-throughput screens of compound libraries. Expert opinion The tools for in vitro and in vivo screening of anti-T. cruzi compounds have improved dramatically in the last few years and there are now a number of excellent in vivo testing models available; this somewhat alleviates the bottleneck issue of quickly and definitively demonstrating in vivo efficacy in a relevant host animal system. These advances emphasize the potential for additional progress resulting in new treatments for Chagas disease in the coming years. That being said, national and international agencies must improve the coordination of research and development efforts in addition to cultivating the funding sources for the development of these new treatments. PMID:21712965

  9. Prophylactic and therapeutic DNA vaccines against Chagas disease.

    Science.gov (United States)

    Arce-Fonseca, Minerva; Rios-Castro, Martha; Carrillo-Sánchez, Silvia del Carmen; Martínez-Cruz, Mariana; Rodríguez-Morales, Olivia

    2015-01-01

    Chagas disease is a zoonosis caused by Trypanosoma cruzi in which the most affected organ is the heart. Conventional chemotherapy has a very low effectiveness; despite recent efforts, there is currently no better or more effective treatment available. DNA vaccines provide a new alternative for both prevention and treatment of a variety of infectious disorders, including Chagas disease. Recombinant DNA technology has allowed some vaccines to be developed using recombinant proteins or virus-like particles capable of inducing both a humoral and cellular specific immune response. This type of immunization has been successfully used in preclinical studies and there are diverse models for viral, bacterial and/or parasitic diseases, allergies, tumors and other diseases. Therefore, several research groups have been given the task of designing a DNA vaccine against experimental infection with T. cruzi. In this review we explain what DNA vaccines are and the most recent studies that have been done to develop them with prophylactic or therapeutic purposes against Chagas disease.

  10. Scrutinizing the Biomarkers for the Neglected Chagas Disease: How Remarkable!

    Science.gov (United States)

    Pinho, Rosa T.; Waghabi, Mariana C.; Cardillo, Fabíola; Mengel, José; Antas, Paulo R. Z.

    2016-01-01

    Biomarkers or biosignature profiles have become accessible over time in population-based studies for Chagas disease. Thus, the identification of consistent and reliable indicators of the diagnosis and prognosis of patients with heart failure might facilitate the prioritization of therapeutic management to those with the highest chance of contracting this disease. The purpose of this paper is to review the recent state and the upcoming trends in biomarkers for human Chagas disease. As an emerging concept, we propose a classification of biomarkers based on plasmatic-, phenotype-, antigenic-, genetic-, and management-related candidates. The available data revisited here reveal the lessons learned thus far and the existing challenges that still lie ahead to enable biomarkers to be employed consistently in risk evaluation for this disease. There is a strong need for biomarker validation, particularly for biomarkers that are specific to the clinical forms of Chagas disease. The current failure to achieve the eradication of the transmission of this disease has produced determination to solve this validation issue. Finally, it would be strategic to develop a wide variety of biomarkers and to test them in both preclinical and clinical trials. PMID:27563302

  11. Opportunity cost for early treatment of Chagas disease in Mexico.

    Directory of Open Access Journals (Sweden)

    Janine M Ramsey

    2014-04-01

    Full Text Available BACKGROUND: Given current neglect for Chagas disease in public health programs in Mexico, future healthcare and economic development policies will need a more robust model to analyze costs and impacts of timely clinical attention of infected populations. METHODOLOGY/PRINCIPAL FINDINGS: A Markov decision model was constructed to simulate the natural history of a Chagas disease cohort in Mexico and to project the associated short and long-term clinical outcomes and corresponding costs. The lifetime cost for a timely diagnosed and treated Chagas disease patient is US$ 10,160, while the cost for an undiagnosed individual is US$ 11,877. The cost of a diagnosed and treated case increases 24-fold from early acute to indeterminate stage. The major cost component for lifetime cost was working days lost, between 44% and 75%, depending on the program scenario for timely diagnosis and treatment. CONCLUSIONS/SIGNIFICANCE: In the long term, it is cheaper to diagnose and treat chagasic patients early, instead of doing nothing. This finding by itself argues for the need to shift current policy, in order to prioritize and attend this neglected disease for the benefit of social and economic development, which implies including treatment drugs in the national formularies. Present results are even more relevant, if one considers that timely diagnosis and treatment can arrest clinical progression and enhance a chronic patient's quality of life.

  12. The Role of Haptoglobin Genotypes in Chagas Disease

    Directory of Open Access Journals (Sweden)

    Ninomar Mundaray Fernández

    2014-01-01

    Full Text Available Although the number of people infected with T. cruzi is on the rise, host genetic and immune components that are crucial in the development of the Chagas disease have been discovered. We investigated the frequency of polymorphisms in the gene encoding haptoglobin of patients with chronic Chagas disease. The results suggest that while the HP1-1 genotype may confer protection against infection and the development of chronic Chagas disease due to the rapid metabolism of the Hp1-1-Hb complex and its anti-inflammatory activity, the presence of HP2-2 genotype may increase susceptibility towards a chronic condition of the disease due to a slow metabolism of the Hp2-2-Hb complex, lower antioxidant activity, and increased inflammatory reactivity, which lead to cell damage and a deterioration of the cardiac function. Finally, correlations between HP genotypes in different age groups and cardiac manifestations suggest that HP polymorphism could influence the prognosis of this infectious disease. This study shows some of the relevant aspects of the haptoglobin gene polymorphism and its implications in the T. cruzi infection.

  13. The Role of Haptoglobin Genotypes in Chagas Disease

    Science.gov (United States)

    Mundaray Fernández, Ninomar; Fernández-Mestre, Mercedes

    2014-01-01

    Although the number of people infected with T. cruzi is on the rise, host genetic and immune components that are crucial in the development of the Chagas disease have been discovered. We investigated the frequency of polymorphisms in the gene encoding haptoglobin of patients with chronic Chagas disease. The results suggest that while the HP1-1 genotype may confer protection against infection and the development of chronic Chagas disease due to the rapid metabolism of the Hp1-1-Hb complex and its anti-inflammatory activity, the presence of HP2-2 genotype may increase susceptibility towards a chronic condition of the disease due to a slow metabolism of the Hp2-2-Hb complex, lower antioxidant activity, and increased inflammatory reactivity, which lead to cell damage and a deterioration of the cardiac function. Finally, correlations between HP genotypes in different age groups and cardiac manifestations suggest that HP polymorphism could influence the prognosis of this infectious disease. This study shows some of the relevant aspects of the haptoglobin gene polymorphism and its implications in the T. cruzi infection. PMID:25147423

  14. Sudorese em pacientes com moléstia de chagas crônica Sweating in patients with chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    Edymar Jardim

    1967-09-01

    Full Text Available Foi estudada a sudoração em pacientes com moléstia de Chagas crônica, mediante estímulo térmico (teste de Minor. As perdas hídricas dos pacientes chagásicos foram significativamente menores do que as dos pacientes não chagásicos.The sweating in patients with chronic Chagas' disease by using thermic stimulus (Minor test is studied. The loss of water was significantly lower in the patients with Chagas' disease when compared with the loss in non chagasic patients.

  15. Benznidazole Shortage Makes Chagas Disease a Neglected Tropical Disease in Developed Countries: Data from Spain

    Science.gov (United States)

    Navarro, Miriam; Norman, Francesca F.; Pérez-Molina, José Antonio; López-Vélez, Rogelio

    2012-01-01

    Chagas disease is a neglected tropical disease endemic in Latin America. The first-line treatment option is benznidazole, but stocks are expected to run out in the coming months. Spain would need around 5 million benznidazole tablets. This drug shortage could make Chagas disease a neglected tropical disease also in developed countries. PMID:22826485

  16. Prism adaptation magnitude has differential influences on perceptual versus manual responses.

    Science.gov (United States)

    Striemer, Christopher L; Russell, Karyn; Nath, Priya

    2016-10-01

    Previous research has indicated that rightward prism adaptation can reduce symptoms of spatial neglect following right brain damage. In addition, leftward prism adaptation can create "neglect-like" patterns of performance in healthy adults on tasks that measure attention and spatial biases. Although a great deal of research has focused on which behaviors are influenced by prism adaptation, very few studies have focused directly on how the magnitude of visual shift induced by prisms might be related to the observed aftereffects, or the effects of prisms on measures of attentional and spatial biases. In the current study, we examined these questions by having groups of healthy adult participants complete manual line bisection and landmark tasks prior to and following adaptation to either 8.5° (15 diopter; n = 22) or 17° (30 diopter; n = 25) leftward shifting prisms. Our results demonstrated a significantly larger rightward shift in straight-ahead pointing (a measure of prism aftereffect) following adaptation to 17°, compared to 8.5° leftward shifting prisms. In addition, only 17° leftward shifting prisms resulted in a significant rightward shift in line bisection following adaptation. However, there was a significant change in performance on the landmark task pre- versus post-adaptation in both the 8.5° and 17° leftward shifting prism groups. Interestingly, correlation analyses indicated that changes in straight-ahead pointing pre- versus post-adaptation were positively correlated with changes in performance on the manual line bisection task, but not the landmark task. These data suggest that larger magnitudes of prism adaptation seem to have a greater influence on tasks that require a response with the adapted hand (i.e., line bisection), compared to tasks that only require a perceptual judgment (i.e., the landmark task). In addition, these data provide further evidence that the effects of prisms on manual and perceptual responses are not related to one

  17. Group-delay Dispersion in Double-prism Pair and Limitation in Broadband Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    程昭; 赵卫

    2002-01-01

    A general expression of group-delay dispersion is obtained without any approximation for a pair of double prisms with an arbitrary apex angle. This expression also includes the change of dispersion resulting from change in insertion of the prism material into the beam by translating prism-pairs. The high-order dispersion can be calculated by means of this expression. The limitation for generation of negative group-delay dispersion by use of prism-pairs is presented for ultrashort laser pulses with broadband spectrum.

  18. Studying the neural bases of prism adaptation using fMRI: A technical and design challenge.

    Science.gov (United States)

    Bultitude, Janet H; Farnè, Alessandro; Salemme, Romeo; Ibarrola, Danielle; Urquizar, Christian; O'Shea, Jacinta; Luauté, Jacques

    2016-12-30

    Prism adaptation induces rapid recalibration of visuomotor coordination. The neural mechanisms of prism adaptation have come under scrutiny since the observations that the technique can alleviate hemispatial neglect following stroke, and can alter spatial cognition in healthy controls. Relative to non-imaging behavioral studies, fMRI investigations of prism adaptation face several challenges arising from the confined physical environment of the scanner and the supine position of the participants. Any researcher who wishes to administer prism adaptation in an fMRI environment must adjust their procedures enough to enable the experiment to be performed, but not so much that the behavioral task departs too much from true prism adaptation. Furthermore, the specific temporal dynamics of behavioral components of prism adaptation present additional challenges for measuring their neural correlates. We developed a system for measuring the key features of prism adaptation behavior within an fMRI environment. To validate our configuration, we present behavioral (pointing) and head movement data from 11 right-hemisphere lesioned patients and 17 older controls who underwent sham and real prism adaptation in an MRI scanner. Most participants could adapt to prismatic displacement with minimal head movements, and the procedure was well tolerated. We propose recommendations for fMRI studies of prism adaptation based on the design-specific constraints and our results.

  19. Epidemiological characteristics of patients with Chagas Disease Características epidemiológicas dos pacientes com Doença de Chagas

    OpenAIRE

    2010-01-01

    The Chagas Disease is an infection caused by Trypanosoma cruzy, transmitted to a hematophague insect, transfused blood or birth, with evolution divided in acute and chronic phases. Object: Analyses variables from patients with Chagas Disease (CD): age, gender, education, prevalence, and presence of co morbid and work. Methodology: The study region is constituted by many peripheral neighborhoods from Montes Claros City- Minas Gerais- Brazil. The study was made with 7150 registered peo...

  20. Asymmetrical prism for beam shaping of laser diode stacks.

    Science.gov (United States)

    Zeng, Xiaodong; Cao, Changqing; An, Yuying

    2005-09-10

    A beam-shaping scheme for a laser diode stack to obtain a flattop output intensity profile is proposed. The shaping element consists of an asymmetrical glass prism. The large divergence-angle compression in the direction perpendicular to the junction plane and the small divergence-angle expansion in the parallel direction are performed simultaneously by a single shaping element. The transformation characteristics are presented, and the optimization performance is investigated based on the ray-tracing method. Analysis shows that a flattop intensity profile can be obtained. This beam-shaping system can be fabricated easily and has a large alignment tolerance.

  1. Inference with Constrained Hidden Markov Models in PRISM

    CERN Document Server

    Christiansen, Henning; Lassen, Ole Torp; Petit, Matthieu

    2010-01-01

    A Hidden Markov Model (HMM) is a common statistical model which is widely used for analysis of biological sequence data and other sequential phenomena. In the present paper we show how HMMs can be extended with side-constraints and present constraint solving techniques for efficient inference. Defining HMMs with side-constraints in Constraint Logic Programming have advantages in terms of more compact expression and pruning opportunities during inference. We present a PRISM-based framework for extending HMMs with side-constraints and show how well-known constraints such as cardinality and all different are integrated. We experimentally validate our approach on the biologically motivated problem of global pairwise alignment.

  2. The demagnetizing field of a non-uniform rectangular prism

    DEFF Research Database (Denmark)

    Smith, Anders; Nielsen, Kaspar Kirstein; Christensen, Dennis;

    2010-01-01

    is solved by an analytical calculation and the coupling between applied field, the demagnetization tensor field and spatially varying temperature is solved through iteration. We show that the demagnetizing field is of great importance in many cases and that it is necessary to take into account the non......The effect of demagnetization on the magnetic properties of a rectangular ferromagnetic prism under non-uniform conditions is investigated. A numerical model for solving the spatially varying internal magnetic field is developed, validated and applied to relevant cases. The demagnetizing field......-uniformity of the internal field, especially for non-constant temperature distributions and composite magnetic materials....

  3. Retracing micro-epidemics of Chagas disease using epicenter regression.

    Directory of Open Access Journals (Sweden)

    Michael Z Levy

    2011-09-01

    Full Text Available Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al español disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S1.

  4. Retracing micro-epidemics of Chagas disease using epicenter regression.

    Science.gov (United States)

    Levy, Michael Z; Small, Dylan S; Vilhena, Daril A; Bowman, Natalie M; Kawai, Vivian; Cornejo del Carpio, Juan G; Cordova-Benzaquen, Eleazar; Gilman, Robert H; Bern, Caryn; Plotkin, Joshua B

    2011-09-01

    Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al español disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S1.

  5. Resveratrol Reverses Functional Chagas Heart Disease in Mice

    Science.gov (United States)

    Mata-Santos, Hilton; Vicentino, Amanda R. R.; Feijó, Daniel F.; Meyer-Fernandes, José R.; Paula-Neto, Heitor A.; Medei, Emiliano; Bozza, Marcelo T.; Lannes-Vieira, Joseli; Paiva, Claudia N.

    2016-01-01

    Chronic chagasic cardiomyopathy (CCC) develops years after acute infection by Trypanosoma cruzi and does not improve after trypanocidal therapy, despite reduction of parasite burden. During disease, the heart undergoes oxidative stress, a potential causative factor for arrhythmias and contractile dysfunction. Here we tested whether antioxidants/ cardioprotective drugs could improve cardiac function in established Chagas heart disease. We chose a model that resembles B1-B2 stage of human CCC, treated mice with resveratrol and performed electrocardiography and echocardiography studies. Resveratrol reduced the prolonged PR and QTc intervals, increased heart rates and reversed sinus arrhythmia, atrial and atrioventricular conduction disorders; restored a normal left ventricular ejection fraction, improved stroke volume and cardiac output. Resveratrol activated the AMPK-pathway and reduced both ROS production and heart parasite burden, without interfering with vascularization or myocarditis intensity. Resveratrol was even capable of improving heart function of infected mice when treatment was started late after infection, while trypanocidal drug benznidazole failed. We attempted to mimic resveratrol’s actions using metformin (AMPK-activator) or tempol (SOD-mimetic). Metformin and tempol mimicked the beneficial effects of resveratrol on heart function and decreased lipid peroxidation, but did not alter parasite burden. These results indicate that AMPK activation and ROS neutralization are key strategies to induce tolerance to Chagas heart disease. Despite all tissue damage observed in established Chagas heart disease, we found that a physiological dysfunction can still be reversed by treatment with resveratrol, metformin and tempol, resulting in improved heart function and representing a starting point to develop innovative therapies in CCC. PMID:27788262

  6. Chagas disease diagnostic applications: present knowledge and future steps

    Science.gov (United States)

    Balouz, Virginia; Agüero, Fernán; Buscaglia, Carlos A.

    2017-01-01

    Chagas disease, caused by the protozoan Trypanosoma cruzi, is a life-long and debilitating illness of major significance throughout Latin America, and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stress the necessity of developing new methods operational in Point-of-Care (PoC) settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery. PMID:28325368

  7. Occurrence of dolichocolon without megacolon in chronic Chagas disease patients

    Directory of Open Access Journals (Sweden)

    Cleudson Castro

    2012-06-01

    Full Text Available INTRODUCTION: Since 1970, lengthening of the rectosigmoid has been suspected to be a solitary manifestation of Chagas colopathy. METHODS: To test this hypothesis, opaque enema was administered on 210 seropositive and 63 seronegative patients, and radiographs in the anteroposterior and posteroanterior positions were examined blind to the serological and clinical findings. The distal colon was measured using a flexible ruler along the central axis of the image from the anus to the iliac crest. RESULTS: Dolichocolon was diagnosed in 31 (14.8% seropositive and 3 (4.8% seronegative patients. The mean length was 57.2 (±12.2cm in seropositive patients and 52.1 (±8.8cm in the seronegative patients (p = 0.000, that is, the distal colon in Chagas patients was, on average, 5.1cm longer. Seropositive female patients presented a mean length of 58.8 (±12.3cm, and seronegative female patients presented 53.2 (±9.1cm (p = 0.002. Seropositive male patients had a mean length of 55 (±11.6cm, and seronegative male patients had 49.9 (±7.8cm (p = 0.02. Among 191 patients without megacolon and suspected megacolon, the mean length was 56.3 (±11.6cm in seropositive individuals and 52 (±8.8cm in seronegative patients (p = 0.003. Among individuals with distal colon >70cm, there were 31 Chagas patients with mean length of 77.9 (±7.1cm and three seronegative with 71.3 (±1.1cm (p = 0.000. Among 179 with distal colon <70cm, seropositive individuals had a mean length of 53.6 (±8.8cm, and seronegative patients had 51.2 (±7.8cm (p = 0.059. Serological positive women had longer distal colon than men (p = 0.02, whereas the mean length were the same among seronegative individuals (p = 0.16. CONCLUSIONS: In endemic areas of Brazil Central, solitary dolichocolon is a radiological Chagas disease signal.

  8. Kinematic markers dissociate error correction from sensorimotor realignment during prism adaptation.

    Science.gov (United States)

    O'Shea, Jacinta; Gaveau, Valérie; Kandel, Matthieu; Koga, Kazuo; Susami, Kenji; Prablanc, Claude; Rossetti, Yves

    2014-03-01

    This study investigated the motor control mechanisms that enable healthy individuals to adapt their pointing movements during prism exposure to a rightward optical shift. In the prism adaptation literature, two processes are typically distinguished. Strategic motor adjustments are thought to drive the pattern of rapid endpoint error correction typically observed during the early stage of prism exposure. This is distinguished from so-called 'true sensorimotor realignment', normally measured with a different pointing task, at the end of prism exposure, which reveals a compensatory leftward 'prism after-effect'. Here, we tested whether each mode of motor compensation - strategic adjustments versus 'true sensorimotor realignment' - could be distinguished, by analyzing patterns of kinematic change during prism exposure. We hypothesized that fast feedforward versus slower feedback error corrective processes would map onto two distinct phases of the reach trajectory. Specifically, we predicted that feedforward adjustments would drive rapid compensation of the initial (acceleration) phase of the reach, resulting in the rapid reduction of endpoint errors typically observed early during prism exposure. By contrast, we expected visual-proprioceptive realignment to unfold more slowly and to reflect feedback influences during the terminal (deceleration) phase of the reach. The results confirmed these hypotheses. Rapid error reduction during the early stage of prism exposure was achieved by trial-by-trial adjustments of the motor plan, which were proportional to the endpoint error feedback from the previous trial. By contrast, compensation of the terminal reach phase unfolded slowly across the duration of prism exposure. Even after 100 trials of pointing through prisms, adaptation was incomplete, with participants continuing to exhibit a small rightward shift in both the reach endpoints and in the terminal phase of reach trajectories. Individual differences in the degree of

  9. The PRISM (Pliocene Palaeoclimate) reconstruction: Time for a paradigm shift

    Science.gov (United States)

    Dowsett, Harry J.; Robinson, Marci M.; Stoll, Danielle K.; Foley, Kevin M.; Johnson, Andrew L. A.; Williams, Mark; Riesselman, Christina

    2013-01-01

    Global palaeoclimate reconstructions have been invaluable to our understanding of the causes and effects of climate change, but single-temperature representations of the oceanic mixed layer for data–model comparisons are outdated, and the time for a paradigm shift in marine palaeoclimate reconstruction is overdue. The new paradigm in marine palaeoclimate reconstruction stems the loss of valuable climate information and instead presents a holistic and nuanced interpretation of multi-dimensional oceanographic processes and responses. A wealth of environmental information is hidden within the US Geological Survey's Pliocene Research,Interpretation and Synoptic Mapping (PRISM) marine palaeoclimate reconstruction, and we introduce here a plan to incorporate all valuable climate data into the next generation of PRISM products. Beyond the global approach and focus, we plan to incorporate regional climate dynamics with emphasis on processes, integrating multiple environmental proxies wherever available in order to better characterize the mixed layer, and developing a finer time slice within the Mid-Piacenzian Age of the Pliocene, complemented by underused proxies that offer snapshots into environmental conditions. The result will be a proxy-rich, temporally nested, process-oriented approach in a digital format - a relational database with geographic information system capabilities comprising a three-dimensional grid representing the surface layer, with a plethora of data in each cell.

  10. The PRISM (Pliocene palaeoclimate) reconstruction: time for a paradigm shift.

    Science.gov (United States)

    Dowsett, Harry J; Robinson, Marci M; Stoll, Danielle K; Foley, Kevin M; Johnson, Andrew L A; Williams, Mark; Riesselman, Christina R

    2013-10-28

    Global palaeoclimate reconstructions have been invaluable to our understanding of the causes and effects of climate change, but single-temperature representations of the oceanic mixed layer for data-model comparisons are outdated, and the time for a paradigm shift in marine palaeoclimate reconstruction is overdue. The new paradigm in marine palaeoclimate reconstruction stems the loss of valuable climate information and instead presents a holistic and nuanced interpretation of multi-dimensional oceanographic processes and responses. A wealth of environmental information is hidden within the US Geological Survey's Pliocene Research, Interpretation and Synoptic Mapping (PRISM) marine palaeoclimate reconstruction, and we introduce here a plan to incorporate all valuable climate data into the next generation of PRISM products. Beyond the global approach and focus, we plan to incorporate regional climate dynamics with emphasis on processes, integrating multiple environmental proxies wherever available in order to better characterize the mixed layer, and developing a finer time slice within the Mid-Piacenzian Age of the Pliocene, complemented by underused proxies that offer snapshots into environmental conditions. The result will be a proxy-rich, temporally nested, process-oriented approach in a digital format-a relational database with geographic information system capabilities comprising a three-dimensional grid representing the surface layer, with a plethora of data in each cell.

  11. When a misperception favors a tragedy: Carlos Chagas and the Nobel Prize of 1921.

    Science.gov (United States)

    Bestetti, Reinaldo B; Couto, Lucélio B; Cardinalli-Neto, Augusto

    2013-11-20

    Carlos Chagas, the discoverer of Chagas' disease was nominated to the Nobel Prize in 1921, but none did win the prize in that year. As a leader of a young scientist team, he discovered all aspects of the new disease from 1909 to 1920. It is still obscure why he did not win the Nobel Prize in 1921. Chagas was discarded by Gunnar Hedrèn on April 16, 1921. Hedrèn should have made a written report about the details of his evaluation to the Nobel Committee. However, such a document has not been found in the Nobel Committee Archives. No evidence of detractions made by Brazilian scientists on Chagas was found. Since Chagas nomination was consistent with the Nobel Committee requirements, as seen in the presentation letter by until now unknown Cypriano de Freitas, it become clear that Chagas did not win the Nobel Prize exclusively because the Nobel Committee did not perceive the importance of his discovery. Thus, it would be fair a posthumous Nobel Prize of 1921 to Carlos Chagas. A diploma of the Nobel Prize, as precedent with Dogmack in 1947, would recognize the merit of the scientist who made the most complete medical discovery of all times.

  12. Risks of endemicity, morbidity and perspectives regarding the control of Chagas disease in the Amazon Region.

    Science.gov (United States)

    Coura, José Rodrigues; Junqueira, Angela Cv

    2012-03-01

    Chagas disease, in the Amazon Region as elsewhere, can be considered an enzootic disease of wild animals or an anthropozoonosis, an accidental disease of humans that is acquired when humans penetrate a wild ecosystem or when wild triatomines invade human dwellings attracted by light or searching for human blood. The risk of endemic Chagas disease in the Amazon Region is associated with the following phenomena: (i) extensive deforestation associated with the displacement of wild mammals, which are the normal sources of blood for triatomines, (ii) adaptation of wild triatomines to human dwellings due to the need for a new source of blood for feeding and (iii) uncontrolled migration of human populations and domestic animals that are already infected with Trypanosoma cruzi from areas endemic for Chagas disease to the Amazon Region. Several outbreaks of severe acute cases of Chagas disease, as well as chronic cases, have been described in the Amazon Region. Control measures targeted to avoiding endemic Chagas disease in the Amazon Region should be the following: improving health education in communities, training public health officials and communities for vector and Chagas disease surveillance and training local physicians to recognise and treat acute and chronic cases of Chagas diseases as soon as possible.

  13. Diffraction theory applied to X-ray imaging with clessidra prism array lenses.

    Science.gov (United States)

    De Caro, Liberato; Jark, Werner

    2008-03-01

    Clessidra (hourglass) lenses, i.e. two large prisms each composed of smaller identical prisms or prism-like objects, can focus X-rays. As these lenses have a periodic structure perpendicular to the incident radiation, they will diffract the beam like a diffraction grating. Refraction in the prisms is responsible for blazing, i.e. for the concentration of the diffracted intensity into only a few diffraction peaks. It is found that the diffraction of coherent radiation in clessidra lenses needs to be treated in the Fresnel, or near-field, regime. Here, diffraction theory is applied appropriately to the clessidra structure in order to show that blazing in a perfect structure with partly curved prisms can indeed concentrate the diffracted intensity into only one peak. When the lens is entirely composed of identical perfect prisms, small secondary peaks are found. Nevertheless, the loss in intensity in the central peak will not lead to any significant widening of this peak. Clessidras with perfect prisms illuminated by full coherent X-ray radiation can then provide spatial resolutions, which are consistent with the increased aperture, and which are far below the height of the single small prisms.

  14. Standardization of motion sickness induced by left-right and up-down reversing prisms

    Science.gov (United States)

    Reschke, M. F.; Vanderploeg, J. M.; Brumley, E. A.; Kolafa, J. J.; Wood, S. J.

    1990-01-01

    Reversing prisms are known to produce symptoms of motion sickness, and have been used to provide a chronic stimulus for training subjects on symptom recognition and regulation. However, testing procedures with reversing prisms have not been standardized. A set of procedures were evaluated which could be standardized using prisms for provocation and to compare the results between Right/Left Reversing Prisms (R/L-RP) and Up/Down Reversing Prisms (U/D-RP). Fifteen subjects were tested with both types of prisms using a self paced walking course throughout the laboratory with work stations established at specified intervals. The work stations provided tasks requiring eye-hand-foot coordination and various head movements. Comparisons were also made between these prism tests and two other standardized susceptibility tests, the KC-135 parabolic static chair test and the Staircase Velocity Motion Test (SVMT). Two different types of subjective symptom reports were compared. The R/L-RP were significantly more provocative than the U/D-RP. The incidence of motion sickness symptoms for the R/L-RP was similar to the KC-135 parabolic static chair test. Poor correlations were found between the prism tests and the other standardized susceptibility tests, which might indicate that different mechanisms are involved in provoking motion sickness for these different tests.

  15. Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

    Science.gov (United States)

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

  16. Simultaneous adaptation of the thumb and index finger of the same hand to opposite prism displacements

    NARCIS (Netherlands)

    Schot, Willemijn D; Brenner, Eli; Smeets, Jeroen B J

    2014-01-01

    It only takes a few goal-directed hand movements to adapt one's movements to a prism-induced displacement of the visual scene. Adaptation to the displacement leads to errors in the opposite direction from the initial displacement when the prisms are removed. Such aftereffects are thought to arise fr

  17. Melatonin in Chagas´ disease: Possible therapeutic value

    Directory of Open Access Journals (Sweden)

    Daniel P. Cardinali

    2011-10-01

    Full Text Available Chagas' disease is a severe health problem in Latin America, causing approximately 50 000 deaths a year, with approximately 18 million infected people. About 25-30% of the patients infected with Trypanosoma cruzi develop the chronic form of the disease. The protective response against T. cruzi depends on both innate and acquired immunity involving macrophages, natural killer cells, T and B lymphocytes, and the production of proinflammatory Th-1 cytokines. In addition, an increased nitric oxide (NO production in macrophages leading to effective microbicidal action is needed to control parasitemia. Melatonin is detectable in T. cruzi and may play a role in promoting infection whereas, when administered in high doses during the acute phase of T. cruzi infection, it can decrease parasitemia while reducing NO production. During chronic disease progression, the sustained oxidative stress concomitant to myocardial damage could be reduced by administering melatonin. It is hypothesized that the coordinated administration of a melatonin agonist like the MT1/MT2 agonist ramelteon, that lacks antioxidant activity and may not affect NO production during the acute phase, and of melatonin in doses high enough to decrease oxidative damage, to preserve mitochondrial and to prevent cardiomyopathy during the chronic phase, could be a novel add-on treatment of Chagas´ disease.

  18. Chagas Disease in Dogs from Endemic Areas of Costa Rica

    Directory of Open Access Journals (Sweden)

    Montenegro Victor M

    2002-01-01

    Full Text Available Dogs with the presumptive diagnosis of Chagas disease are commonly sent to our School of Veterinary Medicine by independent veterinarians. This prompted us to evaluate the prevalence of canine trypanosomiasis in some villages of the Central Valley of Costa Rica. A total of 54 dogs (21 males and 33 females from five rural villages, with ages between 3 months and 10 years old, were bled and submitted to three serological tests: indirect immunofluorescence, indirect hemagglutination and ELISA. Among all animals, 15 (27.7% revealed antibodies (6 pure bred and 9 mongrels and in 3 of them the parasite was also demonstrated by xenodiagnosis. All positive animals except 1, and 9 negative animals (control group were examined by X-rays and electrocardiography, revealing different degrees of cardiomegaly and ECG alteration, consistent with Chagas disease pathology in one dog (SA-11 of the infected ones. Examination of 50 inhabitants living in the houses where dogs and Triatoma dimidiata were found, yielded negative serological reactions. This was assumed to support the hypothesis that dogs are commonly infected by the oral route, a more effective means of infection compared with the vector transmission mechanism that occurs in humans.

  19. Clinical and nutritional profile of individuals with chagas disease

    Directory of Open Access Journals (Sweden)

    Juliana Geraix

    2007-08-01

    Full Text Available Chagas disease (CD, caused by the protozoan Trypanossoma cruzi, affects approximately 18 million individuals in the Americas, 5 million of which live in Brazil. Most chronic sufferers have either the indeterminate form of the disease, without organic compromise, or the cardiac or digestive forms. Despite the importance of this disease, there is no information on the effect of nutrition on CD evolution. We evaluated the clinical-nutritional profile of individuals with CD treated at the Tropical Diseases Nutrition Out-Patient Clinic of the Botucatu School of Medicine, UNESP. A retrospective cohort study was performed between 2002 and 2006, on 66 patients with serum and parasitological diagnosis of CD. Epidemiological, clinical, nutritional, and biochemical data were collected, including gender, age, skin color, smoking, alcoholism, physical activity, weight, stature, body mass index, abdominal circumference, glycemia, and lipid profile. Fifty-three percent were male and 47% female; 96% were white skinned. Mean age was 49.6±6.36 years. The predominant form was indeterminate in 71%; smoking and drinking were recorded in 23% and 17%, respectively. Sedentariness predominated in 83%, and 55% presented increased abdominal circumference. Most, 94%, were overweight or obese. The biochemical exams revealed hyperglycemia in 12% and dyslipidemia in 74%. These findings suggest that the Chagas population presents co-morbidities and risk factors for developing chronic non-transmissible diseases, including cardiovascular diseases, making CD evolution even worse.

  20. Clinical and nutritional profile of individuals with Chagas disease.

    Science.gov (United States)

    Geraix, Juliana; Ardisson, Lidiane Paula; Marcondes-Machado, Jussara; Pereira, Paulo Câmara Marques

    2007-08-01

    Chagas disease (CD), caused by the protozoan Trypanossoma cruzi, affects approximately 18 million individuals in the Americas, 5 million of which live in Brazil. Most chronic sufferers have either the indeterminate form of the disease, without organic compromise, or the cardiac or digestive forms. Despite the importance of this disease, there is no information on the effect of nutrition on CD evolution. We evaluated the clinical-nutritional profile of individuals with CD treated at the Tropical Diseases Nutrition Out-Patient Clinic of the Botucatu School of Medicine, UNESP. A retrospective cohort study was performed between 2002 and 2006, on 66 patients with serum and parasitological diagnosis of CD. Epidemiological, clinical, nutritional, and biochemical data were collected, including gender, age, skin color, smoking, alcoholism, physical activity, weight, stature, body mass index, abdominal circumference, glycemia, and lipid profile. Fifty-three percent were male and 47% female; 96% were white skinned. Mean age was 49.6 +/- 6.36 years. The predominant form was indeterminate in 71%; smoking and drinking were recorded in 23% and 17%, respectively. Sedentariness predominated in 83%, and 55% presented increased abdominal circumference. Most, 94%, were overweight or obese. The biochemical exams revealed hyperglycemia in 12% and dyslipidemia in 74%. These findings suggest that the Chagas population presents co-morbidities and risk factors for developing chronic non-transmissible diseases, including cardiovascular diseases, making CD evolution even worse.

  1. Research priorities for Chagas disease, human African trypanosomiasis and leishmaniasis.

    Science.gov (United States)

    2012-01-01

    This report provides a review and analysis of the research landscape for three diseases - Chagas disease, human African trypanosomiasis and leishmaniasis - that disproportionately afflict poor and remote populations with limited access to health services. It represents the work of the disease reference group on Chagas Disease, Human African Trypanosomiasis and Leishmaniasis (DRG3) which was established to identify key research priorities through review of research evidence and input from stakeholders' consultations. The diseases, which are caused by related protozoan parasites, are described in terms of their epidemiology and diseases burden, clinical forms and pathogenesis, HIV coinfection, diagnosis, drugs and drug resistance, vaccines, vector control, and health-care interventions. Priority areas for research are identified based on criteria such as public health relevance, benefit and impact on poor populations and equity, and feasibility. The priorities are found in the areas of diagnostics, drugs, vector control, asymptomatic infection, economic analysis of treatment and vector control methods, and in some specific issues such as surveillance methods or transmission-blocking vaccines for particular diseases. This report will be useful to researchers, policy and decision-makers, funding bodies, implementation organizations, and civil society. This is one of ten disease and thematic reference group reports that have come out of the TDR Think Tank, all of which have contributed to the development of the Global Report for Research on Infectious Diseases of Poverty, available at: www.who.int/tdr/stewardship/global_report/en/index.html.

  2. Current status and perspectives of cell therapy in Chagas disease

    Directory of Open Access Journals (Sweden)

    Milena Botelho Pereira Soares

    2009-07-01

    Full Text Available One century after its discovery, Chagas disease, caused by the protozoan, Trypanosoma cruzi, remains a major health problem in Latin America. Mortality and morbidity are mainly due to chronic processes that lead to dysfunction of the cardiac and digestive systems. About one third of the chronic chagasic individuals have or will develop the symptomatic forms of the disease, with cardiomyopathy being the most common chronic form. This is a progressively debilitating disease for which there are no currently available effective treatments other than heart transplantation. Like in other cardiac diseases, tissue engineering and cell therapy have been investigated in the past few years as a means of recovering the heart function lost as a consequence of chronic damage caused by the immune-mediated pathogenic mechanisms elicited in individuals with chronic chagasic cardiomyopathy. Here we review the studies of cell therapy in animal models and patients with chronic Chagas disease and the perspectives of the recovery of the heart function lost due to infection with T. cruzi.

  3. Specific circulating immune complexes in acute chagas' disease

    Directory of Open Access Journals (Sweden)

    Ricardo Corral

    1987-02-01

    Full Text Available The presence of circulating immune complexes formed by IgM and IgG (CIC-IgM and CIC-IgG was investigated, using antigen-specific enzyme-immunoassays (ELISA, in 30 patients with acute Chagas' disease who showed parasitemia and inoculation chagoma. Control population consisted of patients with chronic T. cruzi infection (30, acute toxoplasmosis 10, leishmaniasis (8, rheumatoid arthritis (3 and healthy individuals with negative serology for Chagas* disease (30. Acute chagasic patients were 100% CIC-IgG and 96.66% CIC-IgM positive whereas immunofluorescence tests yielded 90% and 86.66% of positivity for specific IgG and IgM antibodies, respectively. Chronic patients were 68% CIC-IgG and 0% CIC-IgM positive. The 30 negative and the 21 cross-reaction controls proved negative for ELISA (CIC-IgM and CIC-IgG. The high sensitivity of ELISA assays would allow early immunologic diagnosis, as well as prompt treatment, of acute T. cruzi infection, thus eliminating the problem of the false-positive and false-negative results which affects traditional methods for detection of circulating antibodies.

  4. Epidemiology of Chagas disease in Ecuador. A brief review

    Directory of Open Access Journals (Sweden)

    Aguilar V H Marcelo

    1999-01-01

    Full Text Available Chagas disease is a complex public health problem that has been underestimated in Ecuador. Here we review the relevant published information, and present unpublished and new data that help to understand the current Chagas disease epidemiological situation and its evolution in the country. Three main characteristics have been identified: (i persistence of Trypanosoma cruzi transmission in already known foci; (ii a marked endemicity in some urban areas of Guayaquil; and (iii the transformation of new Amazon foci into truly endemic areas. The situation in other suspect areas remains uncertain. Five Triatominae species have been implicated in the transmission of T. cruzi to people in Ecuador (Triatoma dimidiata, Rhodnius ecuadoriensis, R. pictipes, R. robustus and Panstrongylus geniculatus, but some others may also play a role in some areas (P. rufotuberculatus, P. howardi, T. carrioni and P. chinai. Other Triatominae reported seem to have little or no epidemiological relevance (T. venosa, T. dispar, Eratyrus mucronatus, E. cuspidatus, P. lignarius and Cavernicola pilosa. High frequency of acute cases and severe chronic disease has been observed. Although cardiomyopathy is more frequent, serious digestive disease is also present. It is estimated that around 120,000-200,000 people may be infected. 2.2 to 3.8 million people are estimated to live under transmission risk conditions.

  5. Squalene synthase as a target for Chagas disease therapeutics.

    Directory of Open Access Journals (Sweden)

    Na Shang

    2014-05-01

    Full Text Available Trypanosomatid parasites are the causative agents of many neglected tropical diseases and there is currently considerable interest in targeting endogenous sterol biosynthesis in these organisms as a route to the development of novel anti-infective drugs. Here, we report the first x-ray crystallographic structures of the enzyme squalene synthase (SQS from a trypanosomatid parasite, Trypanosoma cruzi, the causative agent of Chagas disease. We obtained five structures of T. cruzi SQS and eight structures of human SQS with four classes of inhibitors: the substrate-analog S-thiolo-farnesyl diphosphate, the quinuclidines E5700 and ER119884, several lipophilic bisphosphonates, and the thiocyanate WC-9, with the structures of the two very potent quinuclidines suggesting strategies for selective inhibitor development. We also show that the lipophilic bisphosphonates have low nM activity against T. cruzi and inhibit endogenous sterol biosynthesis and that E5700 acts synergistically with the azole drug, posaconazole. The determination of the structures of trypanosomatid and human SQS enzymes with a diverse set of inhibitors active in cells provides insights into SQS inhibition, of interest in the context of the development of drugs against Chagas disease.

  6. Squalene Synthase As a Target for Chagas Disease Therapeutics

    Science.gov (United States)

    Chan, Hsiu-Chien; Li, Jikun; Zheng, Yingying; Huang, Chun-Hsiang; Ren, Feifei; Chen, Chun-Chi; Zhu, Zhen; Galizzi, Melina; Li, Zhu-Hong; Rodrigues-Poveda, Carlos A.; Gonzalez-Pacanowska, Dolores; Veiga-Santos, Phercyles; de Carvalho, Tecia Maria Ulisses; de Souza, Wanderley; Urbina, Julio A.; Wang, Andrew H.-J.; Docampo, Roberto; Li, Kai; Liu, Yi-Liang; Oldfield, Eric; Guo, Rey-Ting

    2014-01-01

    Trypanosomatid parasites are the causative agents of many neglected tropical diseases and there is currently considerable interest in targeting endogenous sterol biosynthesis in these organisms as a route to the development of novel anti-infective drugs. Here, we report the first x-ray crystallographic structures of the enzyme squalene synthase (SQS) from a trypanosomatid parasite, Trypanosoma cruzi, the causative agent of Chagas disease. We obtained five structures of T. cruzi SQS and eight structures of human SQS with four classes of inhibitors: the substrate-analog S-thiolo-farnesyl diphosphate, the quinuclidines E5700 and ER119884, several lipophilic bisphosphonates, and the thiocyanate WC-9, with the structures of the two very potent quinuclidines suggesting strategies for selective inhibitor development. We also show that the lipophilic bisphosphonates have low nM activity against T. cruzi and inhibit endogenous sterol biosynthesis and that E5700 acts synergistically with the azole drug, posaconazole. The determination of the structures of trypanosomatid and human SQS enzymes with a diverse set of inhibitors active in cells provides insights into SQS inhibition, of interest in the context of the development of drugs against Chagas disease. PMID:24789335

  7. A multi-species bait for Chagas disease vectors.

    Directory of Open Access Journals (Sweden)

    Theo Mota

    2014-02-01

    Full Text Available BACKGROUND: Triatomine bugs are the insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. These insects are known to aggregate inside shelters during daylight hours and it has been demonstrated that within shelters, the aggregation is induced by volatiles emitted from bug feces. These signals promote inter-species aggregation among most species studied, but the chemical composition is unknown. METHODOLOGY/PRINCIPAL FINDINGS: In the present work, feces from larvae of the three species were obtained and volatile compounds were identified by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS. We identified five compounds, all present in feces of all of the three species: Triatoma infestans, Panstrongylus megistus and Triatoma brasiliensis. These substances were tested for attractivity and ability to recruit insects into shelters. Behaviorally active doses of the five substances were obtained for all three triatomine species. The bugs were significantly attracted to shelters baited with blends of 160 ng or 1.6 µg of each substance. CONCLUSIONS/SIGNIFICANCE: Common compounds were found in the feces of vectors of Chagas disease that actively recruited insects into shelters, which suggests that this blend of compounds could be used for the development of baits for early detection of reinfestation with triatomine bugs.

  8. Urban transmission of Chagas disease in Cochabamba, Bolivia

    Directory of Open Access Journals (Sweden)

    N Medrano-Mercado

    2008-08-01

    Full Text Available Chagas disease is a major public health problem in Bolivia. In the city of Cochabamba, 58% of the population lives in peripheral urban districts ("popular zones" where the infection prevalence is extremely high. From 1995 to 1999, we studied the demographics of Chagas infections in children from five to 13 years old (n = 2218 from the South zone (SZ and North zone (NZ districts, which differ in social, environmental, and agricultural conditions. Information gathered from these districts demonstrates qualitative and quantitative evidence for the active transmission of Trypanosoma cruzi in urban Cochabamba. Seropositivity was high in both zones (25% in SZ and 19% in NZ. We observed a high risk of infection in children from five to nine years old in SZ, but in NZ, a higher risk occurred in children aged 10-13, with odds ratio for infection three times higher in NZ than in SZ. This difference was not due to triatomine density, since more than 1,000 Triatoma infestans were captured in both zones, but was possibly secondary to the vector infection rate (79% in SZ and 37% in NZ. Electrocardiogram abnormalities were found to be prevalent in children and pre-adolescents (SZ = 40%, NZ = 17%, indicating that under continuous exposure to infection and re-infection, a severe form of the disease may develop early in life. This work demonstrates that T. cruzi infection should also be considered an urban health problem and is not restricted to the rural areas and small villages of Bolivia.

  9. Relationship between Timing Jitter and Prism Separation in Mode-locked Solid State Lasers

    Institute of Scientific and Technical Information of China (English)

    LU Hong

    2001-01-01

    The function expression of the group delay dispersion (GDD) depending on the prism separation and the normal displacement is derived, and that the GDD is proportional to the prism separation and near to a linear function of the normal displacement in the case of small normal displacement are found. Then we discuss the timing jitter caused by the amplified spontaneous emission (ASE) which depends on the prism separation and the normal displacement. We find that the timing jitter is near to a linear function of the prism separation and can be regrded as a linear function of the normal displacement in the case of small normal displacement. Based on the theoretic work, we suggest an experimental setup to measure the relationship between the timing jitter and the prism separation or the normal displacement.

  10. Foreword: contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen

    2012-01-01

    listing under the U.S. Endangered Species Act and the Canadian Species at Risk Act. To meet the need for information on population size and trends, shorebird biologists from Canada and the United States proposed a shared blueprint for shorebird monitoring across the Western Hemisphere in the late 1990s; this effort was undertaken in concert with the development of the Canadian and the U.S. Shorebird Conservation Plans. Soon thereafter, partners in the monitoring effort adopted the name "Program for Regional and International Shorebird Monitoring" (PRISM). Among the primary objectives of PRISM were to estimate the population sizes and trends of breeding North American shorebirds and describe their distributions. PRISM members evaluated ongoing and potential monitoring approached to address 74 taxa (including subspecies) and proposed a combination of arctic and boreal breeding surveys, temperate breeding and non-breeding surveys, and neotropical surveys.

  11. Contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen

    2012-01-01

    for assessing its vulnerability and subsequent listing under the U.S. Endangered Species Act and the Canadian Species at Risk Act. To meet the need for information on population size and trends, shorebird biologists from Canada and the United States proposed a shared blueprint for shorebird monitoring across the Western Hemisphere in the late 1990s; this effort was undertaken in concert with the development of the Canadian and U.S. Shorebird Conservation Plans (Donaldson et al. 2000, Brown et aL 2001). Soon thereafter, partners in the monitoring effort adopted the name "Program for Regional and International Shorebird Monitoring" (PRISM). Among the primary objectives of PRISM were to estimate the population sizes and trends of breeding North American shorebirds and describe their distributions (Bart et al. 2002). PRISM members evaluated ongoing and potential monitoring approaches to address 74 taxa (including subspecies) and proposed a combination of arctic andboreal breeding surveys, temperate breeding and non-breeding surveys, and neotropical surveys.

  12. Structural and Seafloor Morphological Evidence for Collapse of the Nankai Trough Accretionary Prism

    Science.gov (United States)

    Curewitz, D.; Harris, R.; Kimura, G.; Screaton, E. J.; 314/315/316 Science Party, I.

    2008-12-01

    Recent models for the evolution and structural architecture of accretionary prisms have suggested that the overall behavior of these systems is governed by the dynamic relationship between the geometry of the basal thrusts and the shape of the seafloor, coupled with the state of the basal thrust (slipping, creeping, or locked), the mechanical characteristics of the prism rocks, and the structure of the internal parts of the prism. In the NanTroSEIZE study area, the seafloor along the outer edge of the accretionary prism adjacent to the trench (the prism toe) exhibits a number of features indicative of gravitational collapse, including several listric headwall scarps and associated debris-slide and landslide deposits. Cores collected from the toe of the prism during IODP Expedition 316 contain a wide array of structures, including several populations of faults exhibiting orientations consistent with the geometry of the inferred headwall scarps. Borehole temperature measurements collected near the toe of the prism (and near areas affected by these inferred submarine slides) give rise to anomalously low heat flow values. Taken together, these data suggest that the toe of the Nankai Accretionary Prism offshore the Kii Peninsula, Japan, is currently in a state of collapse. The expression of this mechanical state is found in the along-trench succession of landslide andother gravitational collapse features, the arcuate or listric fault systems that form the detachment surface for these slides, and the inferred infiltration of seawater into the prism via these fault systems, resulting in drastic (and ongoing) cooling of the prism toe by advecting seawater.

  13. A VUV prism spectrometer for RICH radiator refractometry

    CERN Document Server

    Moyssides, P G; Fokitis, E

    2000-01-01

    A prism spectrometer has been developed to operate in the VUV wavelength range from 120 to 200 nm. It can be used as a pre- disperser in conjunction with a Fabry-Perot based gas refractometer. This instrument has also been used to measure the refractive index of the liquid radiator C/sub 6/F/sub 14/ in various spectral lines. This radiator is used in the RICH detectors of the DELPHI experiment and has been proposed for ALICE, and LHCb experiments. The spectral resolution of the system is improved as the wavelength decreases and the data are consistent with a wavelength accuracy about 0.4 nm at 140 nm. The results for the dispersion curve of the above liquid are presented. (17 refs).

  14. Acoustic Prism for Continuous Beam Steering Based on Piezoelectric Metamaterial

    CERN Document Server

    Xu, Jiawen

    2016-01-01

    This paper investigates an acoustic prism for continuous acoustic beam steering by a simple frequency sweep. This idea takes advantages of acoustic wave velocity shifting in metamaterials in the vicinity of local resonance. We apply this concept into the piezoelectric metamaterial consisting of host medium and piezoelectric LC shunt. Theoretical modeling and FEM simulations are carried out. It is shown that the phase velocity of acoustic wave changes dramatically in the vicinity of local resonance. The directions of acoustic wave can be adjusted continuously between 2 to 16 degrees by a simple sweep of the excitation frequency. Such an electro-mechanical coupling system has a feature of adjusting local resonance without altering the mechanical part of the system.

  15. Mass spectrometers based on a cone-shaped acromatic prism

    Energy Technology Data Exchange (ETDEWEB)

    Spivak-Lavrov, I.F. [Pedagogical Inst. of Aktyubinsk (Kazakhstan)

    1995-09-01

    We have elaborated a mass spectrometer without lenses consisting of one conic achromatic prism. It has a specific mass dispersion which is equal to 67.5 mm/m per 1% change of mass. (By specific dispersion we mean linear dispersion related to the main path.) The pass of charged particles with different emittance is investigated with the help of integrating precise equations for tracks of charged particles in natural curvilinear coordinates. We have calculated the resolving power and aberration of a mass spectrometer for different beams of particles. It is evident that the mass spectrometer is particularly effective in use when we deal with rather wide ion beams having an insignificant angular divergence in the mean plane. (orig.).

  16. Curved plasma channels: Kerr lens and Airy prism

    CERN Document Server

    Kasparian, Jérôme; 10.2971/jeos.2009.09039

    2010-01-01

    We analytically calculate the transverse energy fluxes that would be respectively induced in high-power Airy beams by the Kerr self-focusing and the Airy profile itself if they were the only active process. In experimental condition representative of laser filamentation experiments of high-power ultrashort laser pulses in air and condensed media, the Kerr lens induces transverse energy fluxes much larger than the Airy "prism" at the main peak. As a consequence, the curved plasma channels in Airy beams are not only a plasma spark on a curved focus, but indeed self-guided filaments, and their curved trajectory appears as a perturbation due to the linear Airy propagation regime.

  17. Russia through the prism of the world biopharmaceutical market.

    Science.gov (United States)

    Bairamashvili, Dmitrij I; Rabinovich, Mikhail L

    2007-07-01

    Trends in the Russian pharmaceutical biotechnology and related fields representing the major sector of domestic biotech are reviewed through the prism of the world biopharmaceuticals market. A special emphasis is placed on biogenerics and follow-on biologics. The revival of national pharmbiotech is seen in close cooperation between private companies and the state, academia and industry. One of the first positive steps toward promoting development of domestic biopharmaceuticals is the Federal Program of subsidized supply of expensive pharmaceuticals (Dopolnitel'- noe Lekarstvennoe Obespechenie). The program allows the Russian government to purchases expensive drugs to be provided free of cost to certain preferential categories of individuals. As an example, production of recombinant human insulin by the largest Russian fundamental biotechnological institute, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry under the trademark Insuran (Insulin produced by the Russian Academy of Science) is reviewed. Some prospects and problems of Russian biotech research related to medical area are briefly discussed.

  18. Characterization of deflagrating munitions by rotating prism high speed photography

    Science.gov (United States)

    Kinsey, Trevor J.; Bussell, Tim J.; Chick, Michael C.

    1992-08-01

    We report on the use of a rotating prism high speed camera for determining the characteristics of a munition undergoing rapid deflagration in field experiments. The technique has been applied to study the controlled deflagration of Composition B filled 105 mm shell and 81 mm mortar bombs as representative thick and thin cased munitions respectively; however the report is mostly illustrated with results from the study on 105 mm shell. The deflagration event has been characterized in terms of case expansion rate, initial fragment velocity, time to case burst, time to reaction from the nose end and the deflagration rate of the filling. Products escaping from the fracturing case eventually obscured the image which limited the extent of the measurement.

  19. Larmor labeling of neutron spin using superconducting Wollaston prisms

    Science.gov (United States)

    Li, Fankang

    Neutron spin Larmor labeling using magnetic Wollaston prisms (WP) provides a way to overcome some of the limitations arising from the nature of neutron beams: low flux and divergence. Using superconducting films and tapes, a series of strong, well-defined shaped magnetic fields can be produced due to both the zero-resistance and Meissner effect in superconductors. Using finite element simulations, the criterion to build a superconducting magnetic Wollaston prism with high encoding efficiency and low Larmor phase aberrations are presented. To achieve a high magnetic field and simplify the maintenance, we optimize the design using careful thermal analysis. The measured neutron spin flipping efficiency is measured to be independent of both the neutron wavelength and energizing current, which is a significant improvement over other devices with similar functions. A highly linear variation of the Larmor phase is measured across the device, which ensures a highly uniform encoding of scattering angles into the neutron spin Larmor phase. Using two WPs, the correlation function for a colloidal silica sample was measured by spin echo modulated small angle neutron scattering (SEMSANS) and agrees well with other techniques. Using Monte Carlo code (McStas), we further investigated the SEMSANS setup and showed the requirements to improve its performance. We have proposed a new technique to implement neutron spin echo on a triple axis neutron spectrometer to achieve high resolution measurements of the lifetime of dispersive phonon excitations. The spin echo is tuned by appropriate choice of magnetic fields instead of physically tilting the coils used in traditional methods. This new approach allows a higher energy resolution and a larger effective tilting angle and hence larger group velocity to be measured.

  20. On palms, bugs, and Chagas disease in the Americas.

    Science.gov (United States)

    Abad-Franch, Fernando; Lima, Marli M; Sarquis, Otília; Gurgel-Gonçalves, Rodrigo; Sánchez-Martín, María; Calzada, José; Saldaña, Azael; Monteiro, Fernando A; Palomeque, Francisco S; Santos, Walter S; Angulo, Victor M; Esteban, Lyda; Dias, Fernando B S; Diotaiuti, Liléia; Bar, María Esther; Gottdenker, Nicole L

    2015-11-01

    Palms are ubiquitous across Neotropical landscapes, from pristine forests or savannahs to large cities. Although palms provide useful ecosystem services, they also offer suitable habitat for triatomines and for Trypanosoma cruzi mammalian hosts. Wild triatomines often invade houses by flying from nearby palms, potentially leading to new cases of human Chagas disease. Understanding and predicting triatomine-palm associations and palm infestation probabilities is important for enhancing Chagas disease prevention in areas where palm-associated vectors transmit T. cruzi. We present a comprehensive overview of palm infestation by triatomines in the Americas, combining a thorough reanalysis of our published and unpublished records with an in-depth review of the literature. We use site-occupancy modeling (SOM) to examine infestation in 3590 palms sampled with non-destructive methods, and standard statistics to describe and compare infestation in 2940 palms sampled by felling-and-dissection. Thirty-eight palm species (18 genera) have been reported to be infested by ∼39 triatomine species (10 genera) from the USA to Argentina. Overall infestation varied from 49.1-55.3% (SOM) to 62.6-66.1% (dissection), with important heterogeneities among sub-regions and particularly among palm species. Large palms with complex crowns (e.g., Attalea butyracea, Acrocomia aculeata) and some medium-crowned palms (e.g., Copernicia, Butia) are often infested; in slender, small-crowned palms (e.g., Euterpe) triatomines associate with vertebrate nests. Palm infestation tends to be higher in rural settings, but urban palms can also be infested. Most Rhodnius species are probably true palm specialists, whereas Psammolestes, Eratyrus, Cavernicola, Panstrongylus, Triatoma, Alberprosenia, and some Bolboderini seem to use palms opportunistically. Palms provide extensive habitat for enzootic T. cruzi cycles and a critical link between wild cycles and transmission to humans. Unless effective means to

  1. IL18 Gene Variants Influence the Susceptibility to Chagas Disease

    Science.gov (United States)

    Leon Rodriguez, Daniel A; Carmona, F. David; Echeverría, Luis Eduardo; González, Clara Isabel; Martin, Javier

    2016-01-01

    Chagas disease is a parasitic disorder caused by the infection with the flagellated protozoan Trypanosoma cruzi. According to the World Health Organization, more than six million people are currently infected in endemic regions. Genetic factors have been proposed to influence predisposition to infection and development of severe clinical phenotypes like chronic Chagas cardiomyopathy (CCC). Interleukin 18 (IL18) encodes a proinflammatory cytokine that has been proposed to be involved in controlling T. cruzi infection. In this study, we analyzed the possible role of six IL18 gene variants (rs5744258, rs360722, rs2043055, rs187238, rs1946518 and rs360719), which cover most of the variation within the locus, in the susceptibility to infection by T. cruzi and/or CCC. In total, 1,171 individuals from a Colombian region endemic for Chagas disease, classified as seronegative (n = 595), seropositive asymptomatic (n = 175) and CCC (n = 401), were genotyped using TaqMan probes. Significant associations with T. cruzi infection were observed when comparing seronegative and seropositive individuals for rs187238 (P = 2.18E-03, OR = 0.77), rs360719 (P = 1.49E-03, OR = 0.76), rs2043055 (P = 2.52E-03, OR = 1.29), and rs1946518 (P = 0.0162, OR = 1.22). However, dependence analyses suggested that the association was mainly driven by the polymorphism rs360719. This variant is located within the promoter region of the IL18 gene, and it has been described that it creates a binding site for the transcription factor OCT-1 affecting IL-18 expression levels. In addition, no evidence of association was observed between any of the analyzed IL18 gene polymorphisms and the development of CCC. In summary, our data suggest that genetic variation within the promoter region of IL18 is directly involved in the susceptibility to infection by T. cruzi, which provides novel insight into disease pathophysiology and adds new perspectives to achieve a more effective disease control. PMID:27027876

  2. Quinoxaline 1,4-di-N-oxide Derivatives: Interest in the Treatment of Chagas Disease [ Derivados 1,4- i-N-óxido Quinoxalinas: O Interesse no Tratamento da Doença de Chagas

    OpenAIRE

    Elsa Moreno - Viguri; Silvia Pérez-Silanes

    2013-01-01

    More than 100 million people are at risk of contracting Chagas disease. It is estimated that in 2008, Chagas disease was responsible for the death of more than 10,000 people. Despite the fact that there are more than 100 years since the disease was discove red, safe and effective treatments still have to be found. Therefore, new drugs active against Chagas disease are urgently required. Quinoxaline derivatives show very interesting biological properties (anti-infective, cytotoxic, anticandida...

  3. Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

    OpenAIRE

    2014-01-01

    Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of C...

  4. Mapping of Chagas disease research: analysis of publications in the period between 1940 and 2009

    Directory of Open Access Journals (Sweden)

    José Manuel Ramos

    2011-12-01

    Full Text Available INTRODUCTION: Publications are often used as a measure of success in research work. Chagas disease occurs in Central and Southern America. However, during the past years, the disease has been occurring outside Latin America due to migration from endemic zones. This article describes a bibliometric review of the literature on Chagas disease research indexed in PubMed during a 70-year period. METHODS: Medline was used via the PubMed online service of the U.S. National Library of Medicine from 1940 to 2009. The search strategy was: Chagas disease [MeSH] OR Trypanosoma cruzi [MeSH]. RESULTS: A total of 13,989 references were retrieved. The number of publications increased steadily over time from 1,361 (1940-1969 to 5,430 (2000-2009 (coefficient of determination for linear fit, R²=0.910. Eight journals contained 25% of the Chagas disease literature. Of the publications, 64.2% came from endemic countries. Brazil was the predominant country (37%, followed by the United States (17.6% and Argentina (14%. The ranking in production changed when the number of publications was normalized by estimated cases of Chagas disease (Panama and Uruguay, population (Argentina and Uruguay, and gross domestic product (Bolivia and Brazil. CONCLUSIONS: Several Latin American countries, where the prevalence of T. cruzi infection was not very high, were the main producers of the Chagas disease literature, after adjusting for economic and population indexes. The countries with more estimated cases of Chagas disease produced less research on Chagas disease than some developed countries.

  5. Evaluation of a Recombinant Trypanosoma cruzi Mucin-Like Antigen for Serodiagnosis of Chagas' Disease ▿

    OpenAIRE

    2011-01-01

    Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results. In addition, the specificity of these as...

  6. Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects

    OpenAIRE

    2012-01-01

    Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly t...

  7. Aortic distensibility measured by pulse-wave velocity is not modified in patients with Chagas' disease

    Directory of Open Access Journals (Sweden)

    Arteaga Edmundo

    2006-06-01

    Full Text Available Abstract Background Experimental studies demonstrate that infection with trypanosoma cruzi causes vasculitis. The inflammatory lesion process could hypothetically lead to decreased distensibility of large and small arteries in advanced Chagas' disease. We tested this hypothesis. Methods and results We evaluated carotid-femoral pulse-wave velocity (PWV in 53 Chagas' disease patients compared with 31 healthy volunteers (control group. The 53 patients were classified into 3 groups: 1 16 with indeterminate form of Chagas' disease; 2 18 with Chagas' disease, electrocardiographic abnormalities, and normal systolic function; 3 19 with Chagas' disease, systolic dysfunction, and mild-to-moderate congestive heart failure. No difference was noted between the 4 groups regarding carotid-femoral PWV (8.4 ± 1.1 vs 8.2 ± 1.5 vs 8.2 ± 1.4 vs 8.7 ± 1.6 m/s, P = 0.6 or pulse pressure (39.5 ± 7.6 vs 39.3 ± 8.1 vs 39.5 ± 7.4 vs 39.7 ± 6.9 mm Hg, P = 0.9. A positive, significant, similar correlation occurred between PWV and age in patients with Chagas' disease (r = 0.42, P = 0.002, in controls (r = 0.48, P = 0.006, and also between PWV and systolic blood pressure in both groups (patients with Chagas' disease, r = 0.38, P = 0.005; healthy subjects, r = 0.36, P = 0.043. Conclusion Carotid femoral pulse-wave velocity is not modified in patients with Chagas' disease, suggesting that elastic properties of large arteries are not affected in this disorder.

  8. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

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    Jacques Luauté

    2012-01-01

    Full Text Available Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.

  9. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

    Science.gov (United States)

    Luauté, Jacques; Jacquin-Courtois, Sophie; O'Shea, Jacinta; Christophe, Laure; Rode, Gilles; Boisson, Dominique; Rossetti, Yves

    2012-01-01

    Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed. PMID:23050168

  10. Measurement of the optical characteristics of electrowetting prism array for three-dimensional display

    Science.gov (United States)

    Kim, Yunhee; Choi, Yoon-Sun; Choi, Kyuwhan; Kwon, Yongjoo; Bae, Jungmok; Morozov, Alexander; Lee, Hong-Seok

    2013-03-01

    Recently liquid-based optical devices are emerging as attractive components in three-dimensional (3D) display for its compact structure and fast response time. Among them an electrowetting prism array is one of the promising 3D devices. It steers a beam, which enables to provide corresponding perspectives to observer. For high quality autostereoscopic 3D displays the important factors are the beam steering angle and the beam profile, the optical characteristics. In this paper, we propose a method to measure the optical characteristics of the liquid prism and show experimental results on our prototype electrowetting prism array, which consists of prisms with 200um by 200um size. A modified 4-f system is adopted for the proposed method. It provides two kinds of information of the optical characteristics of the liquid prism at the image plane and at the Fourier plane. First, the proposed measurement setup magnifies the image of the liquid micro prism array so that we can observe the status of the each prism array directly with bare eye and align a mask easily for selecting a prism to be examined at the image plane. Secondly, the steering angle can be calculated by measuring the displacement of the beam at the Fourier plane, where the angular profiles that have important information on the oilwater interface is observed precisely. The principle of the proposed method will be explained, and the measured optical characteristics from experimental results on the liquid prism we fabricated will be provided, which proves the validity of the measurement method.

  11. Low prevalence of Chagas parasite infection in a nonhuman primate colony in Louisiana.

    Science.gov (United States)

    Dorn, Patricia L; Daigle, Megan E; Combe, Crescent L; Tate, Ashley H; Stevens, Lori; Phillippi-Falkenstein, Kathrine M

    2012-07-01

    Chagas disease, an important cause of heart disease in Latin America, is caused by the parasite Trypanosoma cruzi, which typically is transmitted to humans by triatomine insects. Although autochthonous transmission of the Chagas parasite to humans is rare in the United States, triatomines are common, and more than 20 species of mammals are infected with the Chagas parasite in the southern United States. Chagas disease has also been detected in colonies of nonhuman primates (NHP) in Georgia and Texas, and heart abnormalities consistent with Chagas disease have occurred at our NHP center in Louisiana. To determine the level of T. cruzi infection, we serologically tested 2157 of the approximately 4200 NHP at the center; 34 of 2157 primates (1.6%) tested positive. Presence of the T. cruzi parasite was confirmed by hemoculture in 4 NHP and PCR of the cultured parasites. These results strongly suggest local transmission of T. cruzi, because most of the infected NHP were born and raised at this site. All 3 species of NHP tested yielded infected animals, with significantly higher infection prevalence in pig-tailed macaques, suggesting possible exploration of this species as a model organism. The local T. cruzi strain isolated during this study would enhance such investigations. The NHP at this center are bred for use in scientific research, and the effects of the Chagas parasite on infected primates could confuse the interpretation of other studies.

  12. Urban Chagas disease in children and women in primary care centres in Buenos Aires, Argentina

    Science.gov (United States)

    Moscatelli, Guillermo; Berenstein, Ada; Tarlovsky, Ana; Siniawski, Susana; Biancardi, Miguel; Ballering, Griselda; Moroni, Samanta; Schwarcz, Marta; Hernández, Susana; García-Bournissen, Facundo; Cozzi, Andrés Espejo; Freilij, Héctor; Altcheh, Jaime

    2015-01-01

    The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruzi infection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate. PMID:26222020

  13. Urban Chagas disease in children and women in primary care centres in Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Guillermo Moscatelli

    2015-08-01

    Full Text Available The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruziinfection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate.

  14. Chagas Disease: Increased Parasitemia during Pregnancy Detected by Hemoculture

    Science.gov (United States)

    da Rocha Siriano, Liliane; Luquetti, Alejandro Ostermayer; Avelar, Juliana Boaventura; Marra, Neusa Leal; de Castro, Ana Maria

    2011-01-01

    One hundred fifty-two Trypanosoma cruzi seropositive women were submitted to a single hemoculture; 101 were pregnant, and 51 were not pregnant. Seven tubes from each individual were harvested with liver infusion tryptose (LIT) medium and observed monthly until the fifth month. Hemocultures were positive in 50% (76 of 152) of the women. Results showed that the positivity was 29.4% (15 of 51) among non-pregnant women and 60.4% (61 of 101) in pregnant women (P < 0.05). In relation to gestational age, there were significant differences in positivity, with a higher proportion of women with positive hemocultures (20 of 25) before 21 weeks and lower after 30 weeks (10 of 21; P = 0.02). We conclude that pregnancy enhances the parasitemia in Chagas disease, with a higher effect early in pregnancy. PMID:21460012

  15. Agrochemicals against malaria, sleeping sickness, leishmaniasis and Chagas disease.

    Directory of Open Access Journals (Sweden)

    Matthias Witschel

    Full Text Available In tropical regions, protozoan parasites can cause severe diseases with malaria, leishmaniasis, sleeping sickness, and Chagas disease standing in the forefront. Many of the drugs currently being used to treat these diseases have been developed more than 50 years ago and can cause severe adverse effects. Above all, resistance to existing drugs is widespread and has become a serious problem threatening the success of control measures. In order to identify new antiprotozoal agents, more than 600 commercial agrochemicals have been tested on the pathogens causing the above mentioned diseases. For all of the pathogens, compounds were identified with similar or even higher activities than the currently used drugs in applied in vitro assays. Furthermore, in vivo activity was observed for the fungicide/oomyceticide azoxystrobin, and the insecticide hydramethylnon in the Plasmodium berghei mouse model, and for the oomyceticide zoxamide in the Trypanosoma brucei rhodesiense STIB900 mouse model, respectively.

  16. Cost-effectiveness analysis in Chagas' disease vectors control interventions

    Directory of Open Access Journals (Sweden)

    A. M. Oliveira Filho

    1989-01-01

    Full Text Available After a large scale field trial performed in central Brazil envisaging the control of Chagas' disease vectors in an endemic area colonized by Triatoma infestans and T. sordida the cost-effectiveness analysis for each insecticide/formulation was performed. It considered the operational costs and the prices of insecticides and formulations, related to the activity and persistence of each one. The end point was considered to be less than 90% of domicilliary unitis (house + annexes free of infestation. The results showed good cost-effectiveness for a slow-release emulsifiable suspension (SRES based on PVA and containing malathion as active ingredient, as well as for the pyrethroids tested in this assay-cyfluthrin, cypermethrin, deltamethrin and permethrin.

  17. Enfermedad de Chagas-Mazza congenita en Salta

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    Contreras Silvia

    1999-01-01

    Full Text Available Se estudió la infección por T. cruzi en mujeres embarazadas en la localidad de General Güemes, provincia de Salta. La misma fue del 12,3 %. El 8,8% de los recién nacidos estudiados tuvieron diagnóstico de Enfermedad de Chagas utilizando la técnica directa (microhematocrito. Todos fueron tratados con benznidazol a razón de 5mg/kg/día durante 30 dias. Todos presentaron anemia, que fue interpretada como reacción adversa medicamentosa. Se estima que la técnica directa representa la mejor opción para llevar a cabo el diagnóstico de esta enfermedad en el recién nacido. Se ha propuesto un flujograma para el seguimiento de la infección por T. cruzi en el recién nacido.

  18. Membranous nephropathy PLA2R+ associated with Chagas disease.

    Science.gov (United States)

    Xavier-Júnior, José Cândido Caldeira; Silva, Vanessa Dos Santos; Viero, Rosa Marlene

    2015-01-01

    Chagas disease (CD) - a tropical parasitic disease caused by the protozoan Trypanosoma cruzi - is a major health problem in Latin America. The immune response against the parasite is responsible for chronic CD lesions. Currently, there are no reports of an association between CD and membranous nephropathy (MN). The detection of the phospholipase A2 receptor (PLA2R) as a target antigen in idiopathic MN can improve the differential diagnosis of primary and secondary forms of MN. The authors report the case of a male patient with positive serology for CD who presented sudden death and underwent autopsy. Histological sections of the heart showed multifocal inflammatory infiltrate composed mainly of mononuclear cells, leading to myocardiocytes necrosis and interstitial fibrosis. The kidneys showed a MN with positive expression for PLA2R. As far as we know, this is the first report of a case of primary MN in a patient with CD, with severe chronic cardiomyopathy and heart failure.

  19. Clinical forms of Trypanosoma cruzi infected individuals in the chronic phase of Chagas disease in Puebla, Mexico

    OpenAIRE

    2006-01-01

    In Mexico, despite the relatively high seroprevalence of Trypanosoma cruzi infection in humans in some areas, reported morbidity of Chagas disease is not clear. We determined clinical stage in 71 individuals seropositive to T. cruzi in the state of Puebla, Mexico, an area endemic for Chagas disease with a reported seroprevalence of 7.7%. Diagnosis of Chagas disease was made by two standardized serological tests (ELISA, IHA). Individuals were stratified according to clinical studies. All patie...

  20. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries

    OpenAIRE

    Moncayo Alvaro

    2003-01-01

    Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions...

  1. Epicuticular lipids induce aggregation in Chagas disease vectors

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    Juárez M Patricia

    2009-01-01

    Full Text Available Abstract Background The triatomine bugs are vectors of the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. Aggregation behavior plays an important role in their survival by facilitating the location of refuges and cohesion of aggregates, helping to keep them safely assembled into shelters during daylight time, when they are vulnerable to predators. There are evidences that aggregation is mediated by thigmotaxis, by volatile cues from their faeces, and by hexane-extractable contact chemoreceptive signals from their cuticle surface. The epicuticular lipids of Triatoma infestans include a complex mixture of hydrocarbons, free and esterified fatty acids, alcohols, and sterols. Results We analyzed the response of T. infestans fifth instar nymphs after exposure to different amounts either of total epicuticular lipid extracts or individual lipid fractions. Assays were performed in a circular arena, employing a binary choice test with filter papers acting as aggregation attractive sites; papers were either impregnated with a hexane-extract of the total lipids, or lipid fraction; or with the solvent. Insects were significantly aggregated around papers impregnated with the epicuticular lipid extracts. Among the lipid fractions separately tested, only the free fatty acid fraction promoted significant bug aggregation. We also investigated the response to different amounts of selected fatty acid components of this fraction; receptiveness varied with the fatty acid chain length. No response was elicited by hexadecanoic acid (C16:0, the major fatty acid component. Octadecanoic acid (C18:0 showed a significant assembling effect in the concentration range tested (0.1 to 2 insect equivalents. The very long chain hexacosanoic acid (C26:0 was significantly attractant at low doses (≤ 1 equivalent, although a repellent effect was observed at higher doses. Conclusion The detection of contact aggregation pheromones has practical

  2. Update on Chagas' disease in Mexico Actualización sobre la enfermedad de Chagas en México

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    Eric Dumonteil

    1999-07-01

    Full Text Available Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, represents a major public health problem in most of the American continent. As transmission of the parasite is being interrupted in most of South America, the disease remains endemic in various areas of Mexico. We review here some of the information gathered in recent years. Seroprevalence of T. cruzi infection in humans remains relatively high in some areas, and there has been a general increase in the number of chronic cases reported to health authorities in recent years. In fact, chronic chagasic cardiomyopathy appears to be affecting a large number of patients with heart disease, but many cases may be misreported because of the unspecific nature of the clinical symptoms. Epidemiological monitoring of vector and reservoir populations, as well as of human cases is helping focus on endemic areas, but a better coordination and development of these efforts is still needed. Recent studies of parasite biology are in agreement with previous work showing the great diversity of parasite characteristics, and support the need for a regional approach to this zoonosis. Strong and continuing support from health and academic authorities is thus still needed to further improve our understanding of Chagas' disease in Mexico and implement efficient control programs.La enfermedad de Chagas, causada por el parásito protozoario Trypanosoma cruzi, constituye un importante problema de salud pública en el continente americano. La transmisión del parásito se ha ido interrumpiendo en la mayor parte de América del Sur, pero la enfermedad sigue siendo endémica en varias regiones de México. En este artículo se revisa la información más reciente sobre dicha enfermedad. La seroprevalencia de la infección por T. cruzi se ha mantenido a niveles relativamente altos en algunas regiones, y se observa un aumento general en el número de casos reportados a las autoridades de salud en los últimos a

  3. Chagas disease and globalization of the Amazon La enfermedad de Chagas y la globalización de la Amazonia

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    Roberto Briceño-León

    2007-01-01

    Full Text Available The increasing number of autochthonous cases of Chagas disease in the Amazon since the 1970s has led to fear that the disease may become a new public health problem in the region. This transformation in the disease's epidemiological pattern in the Amazon can be explained by environmental and social changes in the last 30 years. The current article draws on the sociological theory of perverse effects to explain these changes as the unwanted result of the shift from the "inward" development model prevailing until the 1970s to the "outward" model that we know as globalization, oriented by industrial forces and international trade. The current article highlights the implementation of five new patterns in agriculture, cattle-raising, mining, lumbering, and urban occupation that have generated changes in the environment and the traditional indigenous habitat and have led to migratory flows, deforestation, sedentary living, the presence of domestic animals, and changes in the habitat that facilitate colonization of human dwellings by vectors and the domestic and work-related transmission of the disease. The expansion of Chagas disease is thus a perverse effect of the globalization process in the Amazon.El incremento de casos autóctonos de la enfermedad de Chagas en la Amazonia a partir de los años setenta hace temer que pueda convertirse en un novedoso problema de salud pública en la región. Este cambio del patrón epidemiológico de la enfermedad en la región amazónica debe ser explicado por las transformaciones ambientales y sociales que han ocurrido en los pasados treinta años. Este artículo utiliza la teoría sociológica de los efectos perversos para explicar esos cambios como el resultado indeseado del cambio de modelo de desarrollo "hacia adentro", que había existido hasta los años setenta, por otro "hacia fuera" que está orientado por las fuerzas de la producción y el comercio internacional que conocemos como globalización. El art

  4. A doença de Chagas no Paraná Chagas disease in the state of Paraná

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    H. C. de Souza-Araujo

    1954-06-01

    Full Text Available In recent speech in Curitiba (May 22nd, 1954, Dr. Mario Pinotti, Director, Serviço Nacional da Malaria, informed that his personnel started on February, 1953, a survey upon chagas Disease in 23 counties of the State of Paraná, South Brazil. out of 895 places surveyed, 678, or 75.7%, were infected by Triatoma infestans klug 1834 and in 234 out of those 678, or 34.5%, this vector was infected by Trypanosoma cruzi. The general natural infection of the insects examined reached 18.86%. The serological survey (Machado-Guerreiro test was positive in 10.7% of the persons examined in jacarezinho and in 28.3% of those living in Bôa Vista. These data suggested the author to actualise the subject. During his control of severe outbreack of malaria in the North part of Paraná, from march to June 1917 he worked in 8 counties. March 1917 he photographed in Boa Vista four girls, severe cases of chronic malaria, two of which showed bi-palpebral oedema, later on considered by Dr. Pinho Simões (1943 as Romanã syndrome (created in 1935 and Prof. Salvador Mazza (1946 classified as typical cases of Chagas' Disease. now, being elapsed 36 years, the National Service of Malaria confirmed the discovery. The region surveyed was populated, in the beginning of this century, by immigrants from the State of Minas Gerais, from where the author believes that were imported the disease and its vectors. In April 1917 the A. discovered that the old town Jatahy was a big focus of Triatoma megista (now Panstrongylus megistus0. All its 43 houses were strongly infested by such hematophagus and amongst the 200 inhabitants seen many were suspicious cases of chronic cases of Chagas's Disease. In the Indians town (three tribes of S. Pedro D' Alcantara, situated in front of Jatahy, in the left side of the river Tibagy, there were no Triatomas nor suspicious cases of trypanosomiasis. In 1919 the author started the control of the endemics by destroying the foci of Triatomas and reforming

  5. Chagas y SIDA, la importancia del diagnóstico precoz

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    Sergio R. Auger

    2005-01-01

    Full Text Available Objetivos: Evaluar las vías de contagio, la reactivación y la evolución de la enfermedad de Chagas en pacientes con HIV. Material y métodos Se incorporaron pacientes internados con SIDA y Chagas reactivo. Se evaluaron la epidemiología, la adicción a drogas, la reactivación de la enfermedad de Chagas y el órgano blanco más afectado, la demora del inicio de tratamiento antiparasitario y la evolución posterior. Se realizaron serologías, estudios parasitológicos en sangre y líquido cefalorraquídeo y exámenes complementarios cardiológicos y neurológicos. El estudio fue retrospectivo observacional y como método estadístico se emplearon las pruebas de chi cuadrado y exacta de Fischer. Resultados Se incluyeron en el estudio 8 pacientes con Chagas y SIDA. La vía de contagio de Chagas fue la vectorial en 5 pacientes (62,5% y la drogadicción endovenosa como hipótesis de alta probabilidad en 3 pacientes (37,5%. De estos últimos, 2 presentaron serología negativa para Chagas con parasitemias positivas. El motivo de internación fue reactivación de la enfermedad de Chagas en 5 pacientes (62,5% y de éstos, 4 sufrieron afección del sistema nervioso central y 1, miocarditis. De los 5 pacientes con agudización de la enfermedad de Chagas, 4 fallecieron a pesar del tratamiento con benznidazol. La iniciación de tratamiento demoró entre 7 y 15 días. Conclusiones La drogadicción endovenosa como nueva vía de contagio de la enfermedad de Chagas se transforma en una hipótesis de alta probabilidad, donde la serología no es relevante para el diagnóstico en pacientes con HIV+ y compromiso neurológico. La reactivación de la enfermedad de Chagas fue frecuente y la mortalidad elevada se relacionó con la falta de diagnóstico y el tratamiento tardío.

  6. Synthesis and Photocatalytic Activity of Ag3PO4 Triangular Prism

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    Pengyu Dong

    2015-01-01

    Full Text Available Ag3PO4 triangular prism was synthesized by a facile chemical precipitation approach by simply adjusting external ultrasonic condition. The as-synthesized Ag3PO4 triangular prism was characterized by X-ray diffraction pattern (XRD, field emission scanning electron microscopy (SEM, fourier transform infrared (FTIR spectra, and ultraviolet-visible diffuse reflectance (UV-vis DRS absorption spectra. The photocatalytic activity of Ag3PO4 triangular prism was evaluated by photodegradation of organic methylene blue (MB, rhodamine B (RhB, and phenol under visible light irradiation. Results showed that Ag3PO4 triangular prism exhibited higher photocatalytic activity than N-doped TiO2 and commercial TiO2 (P25 under visible light irradiation.

  7. Improvement of Mental Imagery after Prism Exposure in Neglect: A Case Study

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    Gilles Rode

    1999-01-01

    Full Text Available Previous work has shown that various symptoms of unilateral neglect, including the pathological shift of the subjective midline to the right, may be improved by a short adaptation period to a prismatic shift of the visual field to the right. We report here the improvement of imagined neglect after prism exposure in a patient with a left unilateral neglect. Despite a strong neglect observed for mental images as well as for conventional tests, the mental evocation of left-sided information from an internal image of the map of France map was fully recovered following prism adaptation to the right. This improvement could not be explained by the alteration of visuomotor responses induced by the prism adaptation. Prism adaptation may therefore act not only on sensory-motor levels but also on a higher cognitive level of mental space representation and/or exploration.

  8. TEST METHOD FOR SINGLE INTERIOR RIGHT ANGLE IN A CORNER CUBE PRISM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new test method for single interior right angle in a corner cube prism is presented. Some key points and parameters are analyzed and derived. The advantage of this method is concluded by comparing with some current conventional methods.

  9. Study on precision processing of L-form ZnSe deflect prism

    Science.gov (United States)

    Ye, Sizhe; Hui, Changshun; Zhang, Hao; Lu, Yongbin

    2016-10-01

    As the core component of optical system of Roll-Pitch seekers, the L-form ZnSe deflect prism is directly affecting the imaging quality of optical. For L-form defect prism's complex polyhedron plane structure and the feature of CVD ZnSe polycrystalline material, this paper propose one processing of single point diamond fly-cutting, analyze the transformation calculation method of each plane's coordinate. A kind of special clamp which ensure that all working surface of prism could be cut by once clamping is designed. Base on parameters of turning for CVD ZnSe , the deflect prisms are been processed, the measure result of angle error is below 12", the surface error (rms) reach 0.022λ, which satisfies the demand of manufacturing accuracy. It provide effective processing methods for optical parts with complex space.

  10. A study on transmitted intensity's perturbance for air-spaced Glan-type polarizing prisms

    CERN Document Server

    Fan, J Y; Wu, F Q; Fan, Ji-Yang; Li, Hong-Xia; Wu, Fu-Quan

    2003-01-01

    The explanation for the perturbance of the transmitted intensity for air-spaced Glan-type polarizing prisms with varying rotation angle newly observed in the experiment is given. It is found that the transmitted intensity depends sensitively on the angle of incidence at the cut of the Glan-type prism. The minute fluctuation for values of the angle of incidence during the rotation of the stepmotor gives rise to the perturbance. The relation between the perturbance and the wavelength and the thickness of the air-gap is carefully investigated. Study shows that the disturbance for the Glan-Foucault prism is much stronger than that for the Glan-Taylor prism, as the experimental results have indicated. Theoretical results are perfectly in accordance with the experimental results. Effective measures for reducing the disturbance are presented.

  11. Finite layer and triangular prism element method to subsidence prediction and stress analysis in underground mining

    Institute of Scientific and Technical Information of China (English)

    LIU Li-min(刘立民); LIU Han-long(刘汉龙); LIAN Chuan-jie(连传杰)

    2003-01-01

    The application of the finite layer & triangular prism element method to the 3D ground subsidence and stress analysis caused by mining is presented. The layer elements and the triangular prism elements have been alternatively used in the numerical simulation system, the displacement pattern, strain matrix, elastic matrix, stiffness matrix, load matrix and the stress matrix of the layer element and triangular prism element have been presented. By means of the Fortran90 programming language, a numerical simulation system based on finite layer & triangular prism element have been built up, and this system is suitable for subsidence prediction and stress analysis of all mining condition and mining methods. Comparing with the infinite element method, this approach dramatically reduces the size of the set of equations that need to be solved, and greatly reduces the amount of data preparation required. It not only saves the internal storage, and the computation time, but also decreases the cost.

  12. PERANCANGAN DAN IMPLEMENTASI SISTEM PENGUKURAN KINERJA DENGAN METODE PERFORMANCE PRISM (Studi Kasus pada Hotel X)

    OpenAIRE

    Iwan Vanany; Dian Tanukhidah

    2004-01-01

    This article described a result of research design of performance measurement system in hotel business with Performance Prism Model. As long as, performance measurement system at hotel X not yet representatived organization performance according to comprehensif and integrated. Because of needed redesign performance measurement system with new model. From the objective condition of hotel X, Performance Prism model more representative than others. The result of design described that stakeholder...

  13. Microwave Experimental Observation of Transmitted Enhanced Goos-Hanchen Displacement in Symmetry-Double-Prism Configuration

    Institute of Scientific and Technical Information of China (English)

    DUAN Tao; GE Guo-Ku; LI Chun-Fang; JIN Peng-Cheng

    2008-01-01

    is theoretically proven that the transmitted Goos-Hanchen (GH) displacement in the symmetry-double prism could be resonantly enhanced when the incident angle is less than but near the critical angle, and is modulated by the slab thickness between two prisms and the incident angle. This enhancement effect is directly observed in microwave experiments in which the incident angle is properly chosen. The measured data are in good agreement with the result of the numerical simulation.

  14. Sensitivity Dependence of Surface Plasmon Resonance Based Sensors on Prism Refractive Index

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We theoretically and experimentally demonstrate that refractive index of the prism used toload metal film has significant influence on sensitivity of surface plasmon resonance based sensors. Theprism with lower refractive index gives the sensors a higher sensitivity in detecting refractive index varia-tions of a sample. We attribute this effect to the fact that a prism with low refractive index will increasecoupling distance between surface plasmons and the medium under investigation.

  15. A prism based magnifying hyperlens with broad-band imaging

    Science.gov (United States)

    Habib, Md. Samiul; Stefani, Alessio; Atakaramians, Shaghik; Fleming, Simon C.; Argyros, Alexander; Kuhlmey, Boris T.

    2017-03-01

    Magnification in metamaterial hyperlenses has been demonstrated using curved geometries or tapered devices, at frequencies ranging from the microwave to the ultraviolet spectrum. One of the main issues of such hyperlenses is the difficulty in manufacturing. In this letter, we numerically and experimentally study a wire medium prism as an imaging device at THz frequencies. We characterize the transmission of the image of two sub-wavelength apertures, observing that our device is capable of resolving the apertures and producing a two-fold magnified image at the output. The hyperlens shows strong frequency dependent artefacts, a priori limiting the use of the device for broad-band imaging. We identify the main source of image aberration as the reflections supported by the wire medium and also show that even the weaker reflections severely affect the imaging quality. In order to correct for the reflections, we devise a filtering technique equivalent to spatially variable time gating so that ultra-broad band imaging is achieved.

  16. PRISM: A DATA-DRIVEN PLATFORM FOR MONITORING MENTAL HEALTH.

    Science.gov (United States)

    Kamdar, Maulik R; Wu, Michelle J

    2016-01-01

    Neuropsychiatric disorders are the leading cause of disability worldwide and there is no gold standard currently available for the measurement of mental health. This issue is exacerbated by the fact that the information physicians use to diagnose these disorders is episodic and often subjective. Current methods to monitor mental health involve the use of subjective DSM-5 guidelines, and advances in EEG and video monitoring technologies have not been widely adopted due to invasiveness and inconvenience. Wearable technologies have surfaced as a ubiquitous and unobtrusive method for providing continuous, quantitative data about a patient. Here, we introduce PRISM-Passive, Real-time Information for Sensing Mental Health. This platform integrates motion, light and heart rate data from a smart watch application with user interactions and text entries from a web application. We have demonstrated a proof of concept by collecting preliminary data through a pilot study of 13 subjects. We have engineered appropriate features and applied both unsupervised and supervised learning to develop models that are predictive of user-reported ratings of their emotional state, demonstrating that the data has the potential to be useful for evaluating mental health. This platform could allow patients and clinicians to leverage continuous streams of passive data for early and accurate diagnosis as well as constant monitoring of patients suffering from mental disorders.

  17. PrismTech Data Distribution Service Java API Evaluation

    Science.gov (United States)

    Riggs, Cortney

    2008-01-01

    My internship duties with Launch Control Systems required me to start performance testing of an Object Management Group's (OMG) Data Distribution Service (DDS) specification implementation by PrismTech Limited through the Java programming language application programming interface (API). DDS is a networking middleware for Real-Time Data Distribution. The performance testing involves latency, redundant publishers, extended duration, redundant failover, and read performance. Time constraints allowed only for a data throughput test. I have designed the testing applications to perform all performance tests when time is allowed. Performance evaluation data such as megabits per second and central processing unit (CPU) time consumption were not easily attainable through the Java programming language; they required new methods and classes created in the test applications. Evaluation of this product showed the rate that data can be sent across the network. Performance rates are better on Linux platforms than AIX and Sun platforms. Compared to previous C++ programming language API, the performance evaluation also shows the language differences for the implementation. The Java API of the DDS has a lower throughput performance than the C++ API.

  18. Multiplicity of carbohydrate-binding sites in -prism fold lectins: occurrence and possible evolutionary implications

    Indian Academy of Sciences (India)

    Alok Sharma; Divya Chandran; Desh D Singh; M Vijayan

    2007-09-01

    The -prism II fold lectins of known structure, all from monocots, invariably have three carbohydrate-binding sites in each subunit/domain. Until recently, -prism I fold lectins of known structure were all from dicots and they exhibited one carbohydrate-binding site per subunit/domain. However, the recently determined structure of the -prism fold I lectin from banana, a monocot, has two very similar carbohydrate-binding sites. This prompted a detailed analysis of all the sequences appropriate for two-lectin folds and which carry one or more relevant carbohydrate-binding motifs. The very recent observation of a -prism I fold lectin, griffithsin, with three binding sites in each domain further confirmed the need for such an analysis. The analysis demonstrates substantial diversity in the number of binding sites unrelated to the taxonomical position of the plant source. However, the number of binding sites and the symmetry within the sequence exhibit reasonable correlation. The distribution of the two families of -prism fold lectins among plants and the number of binding sites in them, appear to suggest that both of them arose through successive gene duplication, fusion and divergent evolution of the same primitive carbohydrate-binding motif involving a Greek key. Analysis with sequences in individual Greek keys as independent units lends further support to this conclusion. It would seem that the preponderance of three carbohydrate-binding sites per domain in monocot lectins, particularly those with the -prism II fold, is related to the role of plant lectins in defence.

  19. Chagas' disease in the Amazon Basin: V. Periurban palms as habitats of Rhodnius robustus and Rhodnius pictipes - triatomine vectors of Chagas' disease

    Directory of Open Access Journals (Sweden)

    M. A. Miles

    1983-12-01

    Full Text Available Trypanosoma cruzi infected Rhodnius robustus and/or Rhodnius pictipes were commonly found, in large numbers, in the Brazilian Amazonian palms Maximiliana regia ("inajá", Acrocomia sclerocarpa ("mucajá" and Orbignya speciosa ("babaçu". The common opossum, Didelphis marsupialis, was the animal most frequently associated with triatomine infested palms. R. pictipes, frequently light-attracted into houses from palm trees, was the probable source of an acute case of Chagas' disease in the vicinity of Belém. It is considered that triatomine infested palms are likely to cause some cases of acute Chagas' disease in the States of Amazonas and Rondônia. Possible control methods are suggested.Rhodnius robustus e/ou Rhodnius pictipes, infectados com Trypanosoma cruzi foram comumente encontrados, em grande numero, nas palmeiras Maximiliana regia (inaja, Acrocomia sclerocarpa (mucaja e Orbignya speciosa (babacu na Amazonia brasileira. O marsupial Didelphis marsupialis foi o animal encontrado mais frequentemente nas palmeiras associadas a alta prevalencia de triatomineos. R. pictipes que e atraido pela luz nas residencias de palmeiras vizinhas, provavelmente e a fonte de um caso agudo de doenca de Chagas nas vizinhancas de Belem. Sugere-se que as palmeiras albergando triatomineos poderiam ser relacionadas com infeccoes humanas de doenca de Chagas nos Estados de Amazonas e Rondonia. Sugere-se, tambem, possiveis metodos de controle.

  20. La enfermedad de Chagas en las Américas: una perspectiva de ecosalud Chagas disease in the Americas: an ecohealth perspective

    Directory of Open Access Journals (Sweden)

    Roberto Briceño-León

    2009-01-01

    Full Text Available El proceso de transmisión de la enfermedad de Chagas ha estado históricamente relacionado con los patrones de ocupación territorial de los asentamientos humanos. En las áreas rurales puede ocurrir más fácilmente el encuentro del vector, los agentes patógenos y los seres humanos, por las condiciones de la vivienda y la pobreza existente en estas zonas. Los procesos migratorios permanentes o estacionales han jugado un papel igualmente importante en el transporte de los vectores y en la infección de la población en las zonas urbanas. Las nuevas fronteras agrícolas del Amazonas se han establecido nuevas áreas de transmisión de la enfermedad. La atención dada a los bancos de sangre ha permitido disminuir la transmisión transfusional, pero la inmigración internacional ha cambiado la situación epidemiológica, pues en Estados Unidos y España viven miles de enfermos que habían sido infectados décadas antes y no encuentran adecuada atención. Los avances en el conocimiento y el control de la enfermedad son mostrados en el artículo, señalando las limitaciones existentes en cuanto al mejoramiento de las condiciones ambientales y de vivienda de los pobres.The historical processes involved in Chagas disease transmission relate to the patterns and conditions of human settlements, especially in rural areas, due to proximity to forest areas, where both vectors and Trypanosoma cruzi can occur, combined with precarious housing conditions and underlying poverty. However, seasonal and permanent rural-urban migration has played a major role in re-mobilizing vectors, T. cruzi, and Chagas-infected individuals. A new agricultural frontier in the Amazon has led to a new transmission pattern, especially with palm trees located close to houses. Improved blood bank surveillance has decreased transmission by blood transfusions. International migration also plays a role in Chagas disease epidemiology. The United States and Spain, where specific health

  1. Epilepsia e doença de chagas cronica

    Directory of Open Access Journals (Sweden)

    Edymar Jardim

    1981-03-01

    Full Text Available A síndrome epiléptica em chagásicos crônicos, foi referida raramente na literatura especializazda, não tendo sido feito até o momento, um estudo detalhado das suas manifestações. Partindo-se da premissa de que a moléstia de Chagas tem por substrato anatômico uma destruição neuronal, procurou-se comparar dois grupos de epilépticos, um dos quais com moléstia de Chagas crônica. Foram estudados 167 pacientes epilépticos, dos quais 44 eram comprovadamente chagásicos. O estudo permitiu coletar dados referentes à procedência dos pacientes, resultado soro-lógico, sexo, idade, época de incidência das manifestações epilépticas, elementos dos exames neurológicos, do líquido cefalorraqueano, eletrencefalográfico e os resultados da terapêutica anticonvulsivante. Como resultados principais destacamos o início tardio da epilepsia nos chagásicos, e o predomínio acentuado das crises parciais com sintomatologia elementar de tipo autonômico. O exame neurológico e o do líquido cefalorraqueano, apesar de apresentarem percentualmente nos seus resultados, taxas moderadamente mais elevadas na incidência de alterações, não caracterizaram síndromes neurológicas bem definidas. O exame eletrencefalográfico, revelou alterações sugestivas de comprometimento orgânico cerebral difuso. A terapêutica anticonvulsivante, baseada na utilização de hidantoinatos, barbitúricos, primidona e benzodiazepínicos, mostrou que o controle das crises foi mais difícil nos chagásicos, exigindo maiores quantidades de medicação, com resultados menos satisfatórios.

  2. Four TDR diseases can be "eliminated". 3. Chagas success in Brazil and Colombia.

    Science.gov (United States)

    1996-03-01

    Recent figures published by Brazil's Chagas disease control program indicate that the disease will soon be eradicated in Brazil. For example, in 1982, 711 Brazilian municipalities reported infestation with Triatoma infestans, the most important domiciliary vector of Chagas disease. However, in 1993, only 83 municipalities reported any infestation. Disease transmission through blood transfusion in the country has also been dramatically reduced. In 1982, 6.5% of blood donations in Brazil were infected with Trypanosoma cruzi, but by 1992 the level of infection had fallen to only 1%. 4.2% of infected individuals aged 7-14 years converted serologically in 1980, compared to only 0.15% in 1994, indicating a 95% decline in the incidence of newly infected cases in that age group. Furthermore, 84,000 infected triatomine insects were captured in households in endemic areas in 1983, far more than the 2500 collected throughout the entire country in 1993. The complete interruption of Chagas disease transmission in Brazil is expected in 1998. Work is also progressing with a control plan by countries in which the disease is transmitted by insects with an extradomiciliary life cycle. Colombia is the 15th of the 21 Chagas-endemic countries in Latin America where, due to blood bank screening, the transfusional transmission of Chagas disease has been interrupted.

  3. Scintigraphy for the detection of myocardial damage in the indeterminate form of Chagas disease

    Energy Technology Data Exchange (ETDEWEB)

    Pedroso, Enio Roberto Pietra; Rezende, Nilton Alves de, E-mail: narezende@terra.com.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina; Abuhid, Ivana Moura [Instituto de Medicina Nuclear e Diagnostico Molecular, Belo Horizonte, MG (Brazil)

    2010-07-15

    Background: non-invasive cardiological methods have been used for the identification of myocardial damage in Chagas disease. Objective: to verify whether the rest/stress myocardial perfusion scintigraphy is able to identify early myocardial damage in the indeterminate form of Chagas disease. Methods: eighteen patients with the indeterminate form of Chagas Disease and the same number of normal controls, paired by sex and age, underwent rest/stress myocardial scintigraphy using sestamibi-99mTc, aiming at detecting early cardiac damage. Results: the results did not show perfusion or ventricular function defects in patients at the indeterminate phase of Chagas disease and in the normal controls, except for a patient who presented signs of ventricular dysfunction in the myocardial perfusion scintigraphy with electrocardiographic gating. Conclusion: the results of this study, considering the small sample size, showed that the rest/stress myocardial scintigraphy using sestamibi-99mTc is not an effective method to detect early myocardial alterations in the indeterminate form of Chagas disease (author)

  4. Pupillary Light Reflexes are Associated with Autonomic Dysfunction in Bolivian Diabetics But Not Chagas Disease Patients.

    Science.gov (United States)

    Halperin, Anthony; Pajuelo, Monica; Tornheim, Jeffrey A; Vu, Nancy; Carnero, Andrés M; Galdos-Cardenas, Gerson; Ferrufino, Lisbeth; Camacho, Marilyn; Justiniano, Juan; Colanzi, Rony; Bowman, Natalie M; Morris, Tiffany; MacDougall, Hamish; Bern, Caryn; Moore, Steven T; Gilman, Robert H

    2016-06-01

    Autonomic dysfunction is common in Chagas disease and diabetes. Patients with either condition complicated by cardiac autonomic dysfunction face increased mortality, but no clinical predictors of autonomic dysfunction exist. Pupillary light reflexes (PLRs) may identify such patients early, allowing for intensified treatment. To evaluate the significance of PLRs, adults were recruited from the outpatient endocrine, cardiology, and surgical clinics at a Bolivian teaching hospital. After testing for Chagas disease and diabetes, participants completed conventional autonomic testing (CAT) evaluating their cardiovascular responses to Valsalva, deep breathing, and orthostatic changes. PLRs were measured using specially designed goggles, then CAT and PLRs were compared as measures of autonomic dysfunction. This study analyzed 163 adults, including 96 with Chagas disease, 35 patients with diabetes, and 32 controls. PLRs were not significantly different between Chagas disease patients and controls. Patients with diabetes had longer latency to onset of pupil constriction, slower maximum constriction velocities, and smaller orthostatic ratios than nonpatients with diabetes. PLRs correlated poorly with CAT results. A PLR-based clinical risk score demonstrated a 2.27-fold increased likelihood of diabetes complicated by autonomic dysfunction compared with the combination of blood tests, CAT, and PLRs (sensitivity 87.9%, specificity 61.3%). PLRs represent a promising tool for evaluating subclinical neuropathy in patients with diabetes without symptomatic autonomic dysfunction. Pupillometry does not have a role in the evaluation of Chagas disease patients.

  5. Triatominae Biochemistry Goes to School: Evaluation of a Novel Tool for Teaching Basic Biochemical Concepts of Chagas Disease Vectors

    Science.gov (United States)

    Cunha, Leonardo Rodrigues; de Oliveria Cudischevitch, Cecília; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; da Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of "Trypanosoma cruzi," the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information obtained by…

  6. Bolivian migrants with Chagas disease in Barcelona, Spain: a qualitative study of dietary changes and digestive problems

    NARCIS (Netherlands)

    Posada, E.; Pell, C.; Angulo, N.; Pinazo, M.J.; Gimeno, F.; Elizalde, I.; Gysels, M.H.; Muñoz, J.; Pool, R.; Gascón, J.

    2011-01-01

    Due to international migration, Chagas disease, endemic in Latin America, has become more common in non-endemic areas. Chronic Chagas disease can cause damage to the digestive system leading to constipation. However, a range of factors influences constipation and a better understanding of the role o

  7. Triatominae Biochemistry Goes to School: Evaluation of a Novel Tool for Teaching Basic Biochemical Concepts of Chagas Disease Vectors

    Science.gov (United States)

    Cunha, Leonardo Rodrigues; de Oliveria Cudischevitch, Cecília; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; da Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of "Trypanosoma cruzi," the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information…

  8. Histological and endoscopic features of the stomachs of patients with Chagas disease in the era of Helicobacter pylori

    OpenAIRE

    Fernanda Machado Fonseca; Renata Margarida Etchebehere; Dulciene Maria Magalhães Queiroz; Andreia Maria Camargos Rocha; Iracema Saldanha Junqueira; Daurin Narciso da Fonseca; Aline Libério Braga Rodrigues; Eduardo Crema; Adriana Gonçalves de Oliveira

    2014-01-01

    Introduction Most studies that have evaluated the stomachs of patients with Chagas disease were performed before the discovery of Helicobacter pylori and used no control groups. This study compared the gastric features of chagasic and non-chagasic patients and assessed whether gastritis could be associated with Chagas disease. ...

  9. 两座修道院和一轴写卷:有关布鲁塞尔写本19606的新知%Two Abbots and a Rotulus: New Light on Brussels 19606

    Institute of Scientific and Technical Information of China (English)

    Karl Ktiegle[荷兰; 杨元铮; 梁雪菲(编译)

    2011-01-01

    Based on codicological, repertorial, iconographical and archival data, the provenance anddating of the 'Brussels rotulus' (Brussels, Royal Library of Belgium, manuscript 19506), a small but significant source of early fourteenth-century music, are reassessed. The origins of the manuscript were unknown up to now, its dating approximate and speculative. It is suggested that the source originated at the former double monastery of Stavelot- Malmedy (situated in the eastern part of modem-day Belgium) in spring 1335. It was presumably intended as an admonitory gift for the newly elected prince - abbot, Winricus de Pomerio (ruled 1335-1342). The revised view illuminates the Cultural sophistication of the Meuse region in the early fourteenth century, which is widely underestimated today, as well as refining our knowledge of the circulation and reception of a group of pieces first transmitted in the (Parisian) -Ro- man de Fauvel- (Paris, National Library of France, manuscript fran? ais 146), a unique and spectacular source combining texts, music, and illustrations in the service of courtly politics and propaganda among the powerful in the capital of late medieval France. The mtulus attests to the rapid reception of this musi- co - symbolic discourse in a rather less visible and considerably smaller center of contemporaneous north- western Europe, as well as its skillful adaptation by the local compiler (s) to politics and power struggles of their own.%布鲁塞尔比利时国家图书馆藏写本号19606的一轴写卷虽然篇幅不长,却和14世纪早期音乐史的研究关系重大。基于写本学、音乐学、图像学及档案资料等方面的考察,本文对布鲁塞尔写卷的出处和年代进行了重新评估。此前的研究对该卷的起源既未明了,对其年代的认定也属推测。人们猜测该卷可能原本是献给新选修道院长温瑞库斯·德·波默里欧(任期1335--1342

  10. The geological perspective of Italy and Chile by Abbot Juan Ignacio Molina between the 18th and 19th centuries La perspectiva geolgica del Abate Juan Ignacio Molina sobre Italia y Chile entre los siglos XVIII y XIX

    Directory of Open Access Journals (Sweden)

    Marco Menichetti

    2011-09-01

    , vegetables and animals within the framework of the then accepted philosophy of the Great Chain of Being. Because of his ideas and statements, apparently endowing animals and plants with human characteristics, Molina was denounced for and then cleared of heterodoxy. Abbot Molina made an important contribution to the study of Chile's Natural History, and to the South American natural sciences in general. Although Molina lived most of his life outside of Chile, he nurtured a deep love and pride for his country. The picture that emerges from his writings contributed to a large degree in acquainting the world with his native land and its native peoples.Las primeras observaciones geolgicas en Chile pueden ser trazadas a travs de Juan Ignacio Molina, un sacerdote jesuita quien haba nacido en Chile en 1740 y muri en Bolonia en 1829. l recibi una formacin acadmica con un fuerte aprendizaje hacia la filosofa, las humanidades y las ciencias en el Colegio Jesutico de Concepcin. En 1767, cuando todos los jesuitas fueron expulsados de Chile y de las colonias espaolas, se refugi en Italia, primero en Imola y posteriormente en Bolonia, donde ense griego en la Universidad y posteriormente ciencias naturales en el Archigimnasio. Durante su estada en Bolonia al final del siglo XVIII, la comunidad jesutica continu teniendo un rol en la enseanza de las ciencias a pesar de la ocupacin napolenica. En Bolonia, tan temprano como en el siglo XVI, Ulisse Adrovani desarroll nuevos conceptos en geologa con su estudio y coleccin sistemtica de fsiles. A comienzos del siglo XVIII, el naturalista y oceangrafo L. F. Marsili, y uno de los padres de la paleontologa, G. Monti, avanzaron sobre el trabajo de Aldrovandi y contribuyeron al crecimiento del Instituto de Ciencias y Museo de Historia Natural en la ciudad. Fue en este contexto natural que Molina public en 1782, en italiano, Saggio sulla storia naturale del Chile. El libro fue dividido en cuatro captulos, los primeros dos dedicados a las ciencias de la

  11. Urbanization, land tenure security and vector-borne Chagas disease.

    Science.gov (United States)

    Levy, Michael Z; Barbu, Corentin M; Castillo-Neyra, Ricardo; Quispe-Machaca, Victor R; Ancca-Juarez, Jenny; Escalante-Mejia, Patricia; Borrini-Mayori, Katty; Niemierko, Malwina; Mabud, Tarub S; Behrman, Jere R; Naquira-Velarde, Cesar

    2014-08-22

    Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases.

  12. Urbanization, land tenure security and vector-borne Chagas disease

    Science.gov (United States)

    Levy, Michael Z.; Barbu, Corentin M.; Castillo-Neyra, Ricardo; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Escalante-Mejia, Patricia; Borrini-Mayori, Katty; Niemierko, Malwina; Mabud, Tarub S.; Behrman, Jere R.; Naquira-Velarde, Cesar

    2014-01-01

    Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases. PMID:24990681

  13. An in-silico investigation of anti-Chagas phytochemicals.

    Science.gov (United States)

    McCulley, Stephanie F; Setzer, William N

    2014-01-01

    Over 18 million people in tropical and subtropical America are afflicted by American trypanosomiasis or Chagas disease. In humans, symptoms of the disease include fever, swelling, and heart and brain damage, usually leading to death. There is currently no effective treatment for this disease. Plant products continue to be rich sources of clinically useful drugs, and the biodiversity of the Neotropics suggests great phytomedicinal potential. Screening programs have revealed numerous plant species and phytochemical agents that have shown in-vitro or in-vivo antitrypanosomal activity, but the biochemical targets of these phytochemicals are not known. In this work, we present a molecular docking analysis of Neotropical phytochemicals, which have already demonstrated antiparasitic activity against Trypanosoma cruzi, with potential druggable protein targets of the parasite. Several protein targets showed in-silico selectivity for trypanocidal phytochemicals, including trypanothione reductase, pteridine reductase 2, lipoamide dehydrogenase, glucokinase, dihydroorotate dehydrogenase, cruzain, dihydrofolate-reductase/thymidylate-synthase, and farnesyl diphosphate synthase. Some of the phytochemical ligands showed notable docking preference for trypanothione reductase, including flavonoids, fatty-acid-derived oxygenated hydrocarbons, geranylgeraniol and the lignans ganschisandrine and eupomatenoid-6.

  14. MORTALITY RISK ASSESSMENT IN PICU USING PRISM-III-24 SCORE

    Directory of Open Access Journals (Sweden)

    Harilal Naik

    2014-11-01

    Full Text Available OBJECTIVE: Assessment of risk of mortality using PRISM III-24 score in children admitted to PICU of Basaweshwara Teaching and General Hospital, attached to Mahadevappa Rampure Medical College, Gulbarga. DESIGN: Prospective cohort study. Setting: PICU of BTGH, Gulbarga. METHODS: 404 patients who had been admitted consecutively to the PICU during a period of 12 months (July 2011 to June 2012 were studied. PRISM III-24 score was calculated. Hospital outcome was recorded as survived/expired. Calibration and discrimination of the model was calculated by Hosmer-Lemeshow goodness-of-fit test and Area under the ROC Curve. The association between r (empirical function and PRISM III-24 score was assessed by Binary Logistic Regression method. RESULTS: Out of 404 patients, 363 (89.85% survived and 41 (10.15% expired. Males formed the majority (227/404. CNS cases (n=118, 29.2% constituted the majority. Mean age, length of hospitalization, and mean PRISM III-24 score were 59.22±51.12 months, 99.84±91.61 hours, and 4.92±7.74 (range 0-36. The test was well designed for the study (goodness-of-fit value P-value 0.186. ROC analysis indicated a strong predictive power for the PRISM III-24 (AUC 0.936. The observed (O mortality rate was 10.15% and the expected (E mortality rate was 10.12% with an O/E ratio of 1.003. CONCLUSION: PRISM III-24 score is a good predictor of mortality in PICU patients under Indian circumstances. The PRISM III-24 scoring system was highly calibrated in our institute.

  15. A three-dimensional multi-agent-based model for the evolution of Chagas' disease.

    Science.gov (United States)

    Galvão, Viviane; Miranda, José Garcia Vivas

    2010-06-01

    A better understanding of Chagas' disease is important because the knowledge about the progression and the participation of the different types of cells in this disease are still lacking. To clarify this system, the kinetics of inflammatory cells and parasite nests was shown in an experiment. Using this experimental data, we have developed a three-dimensional multi-agent-based computational model for the evolution of Chagas' disease. Our model includes five different types of agents: inflammatory cell, fibrosis, cardiomyocyte, fibroblast, and Trypanosoma cruzi. Fibrosis is fixed and the other types of agents can move through the empty space. They move randomly by using the Moore neighborhood. This model reproduces the acute and chronic phases of Chagas' disease and the volume occupied by all different types of cells in the cardiac tissue.

  16. Ecological aspects of the vectorial control of Chagas' disease in Brazil

    Directory of Open Access Journals (Sweden)

    Dias João Carlos P.

    1994-01-01

    Full Text Available The feasibility and most important ecological aspects of vectorial Chagas' disease control are discussed. The spread and maintenance of this disease involve multiple ecological and sociopolitical factors that must be taken into account when control programs are planned, executed and evaluated. In spite of its complexity, Chagas disease can be controlled using methods that target specific mechanisms of transmission, the most important being vectorial and transfusional. Major ecological problems in Chagas' disease control do not exist, even in the case of the chemical control of triatomine vectors. The main challenges for the Brazilian Control Program at this moment are: its maintenance as a political priority; the threat of peridomestic vectors; and the consolidation of permanent horizontal and participative epidemiological surveillance systems against the vector.

  17. Chagas disease (Trypanosoma cruzi and HIV co-infection in Colombia

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    Carolina Hernández

    2014-09-01

    Full Text Available Chagas disease is a complex zoonotic pathology caused by the kinetoplastid Trypanosoma cruzi. This parasite presents remarkable genetic variability and has been grouped into six discrete typing units (DTUs. The association between the DTUs and clinical outcome remains unknown. Chagas disease and co-infection with HIV/AIDS has been reported widely in Brazil and Argentina. Herein, we present the molecular analyses from a Chagas disease patient with HIV/AIDS co-infection in Colombia who presented severe cardiomyopathy, pleural effusion, and central nervous system involvement. A mixed infection by T. cruzi genotypes was detected. We suggest including T. cruzi in the list of opportunistic pathogens for the management of HIV patients in Colombia. The epidemiological implications of this finding are discussed.

  18. [Knowledge, attitudes, and practices concerning Chagas disease in schoolchildren from an endemic area in Peru].

    Science.gov (United States)

    Cabrera, Rufino; Mayo, Carlos; Suárez, Nicolás; Infante, César; Náquira, César; García-Zapata, Marco Tulio A

    2003-01-01

    This study analyzes knowledge, attitudes, and practices concerning Chagas disease among 241 primary schoolchildren in "La Tinguiña", Ica, Peru (December 2000 - January 2001). Less than 1% of those interviewed knew that triatomines transmit Chagas disease, while nearly a quarter recognized the illness based on the appearance of "lumps" on the skin; 35.27% knew that vector infestation is controlled using insecticides; 26.56% recognized the adult stage of the vector, and 21.16% the nymphal instar; 14.11% knew triatomines or "kissing bugs" by the name "chirimacha"; 82.57% would accept an entomological survey, 66.80% would submit to a serological study, and 63.90% would participate in a triatomine search. The study shows that the population, despite having very limited knowledge on the disease and its vectors, shows interest in collaborating. Therefore, it is recommended that Chagas disease surveillance and control include educational programs and community participation.

  19. Aspectos neurológicos da moléstia de chagas

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    Fritz Köberle

    1967-09-01

    Full Text Available Carlos Chagas related in more than two 200 cases, what he called "nervous forms" of trypanosomiasis, that is neurological manifestations from central origin (idiotism, infantilism, pseudo-bulbar paralysis, aphasia, cerebellar ataxia, atetosis, espostic or paralytic diplegia, disbasia. At that time Chagas expressed his concepts as follows: "In relation to the frequency of trypanosomiasis nervous forms we have performed many observations which allow us to state that this disease is the one which causes the largest number of organic affections of the central nervous system, in human pathology". We are plenty convinced by Chagas's statement. By experiments on animals of laboratory we have very often noticed a rather varied neurological symptomatology, being worth point out identical syndromes to those observed by Chagas. Our autopsy material non-rarely include chronic Chagas cases presenting a most varied symtomatology. Among them we have named only three cases of discerebral nanism, a rather rare affection in other parts of the world and relatively frequent in our material. The fact which we have demonstrated, i.e., a relatively great decreasing of number of nervous cells in the peripheral system could happen in the central nervous system as well. Provided that there are only two quantitative works on neuron number diminishing in the central nervous system in mice and rats we decline to go into further details about central neuropathies in man. We emphasized the necessity to perform researches on this field by means of intimate collaboration between clinicians and pathologists, as the only way to confirm on scientific basis all that was observed by the panoramic and genial vision of Carlos Chagas.

  20. Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery

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    Prata Aluízio

    1999-01-01

    Full Text Available Three different periods may be considered in the evolution of knowledge about the clinical and epidemiological aspects of Chagas disease since its discovery: (a early period concerning the studies carried out by Carlos Chagas in Lassance with the collaboration of other investigators of the Manguinhos School. At that time the disease was described and the parasite, transmitters and reservoirs were studied. The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disease; (b second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American countries. Particularly important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of the Romaña sign in the 1930 decade, facilitating the diagnosis of the early phase of the disease. However, the chronic phase, which was the most important, continued to be difficult to recognize; (c period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies conducted by Laranja, Dias and Nóbrega in Bambuí updated the description of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on, the disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d period of enlargement of knowledges on the disease. The studies on denervation conducted in Ribeirão Preto by Fritz Köberle starting in the 1950 decade led to a better understanding of the relations between Chagas disease and megaesophagus and other visceral megas detected in endemic areas.

  1. Estado actual de nuestros conocimientos sobre la enfermedad de chagas en la Republica Mexicana

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    Jorge Tay

    1981-06-01

    Full Text Available Se presentan los datos obtenidos de la revisión minuciosa en relación a enfermedad de Chagas de la literatura médica de la República Mexicana y extranjera desde el afio de 1939 en que por primeira vez se reporta a Trypanosoma cruzi en México, hasta el ano de 1976. Mediante mapas, tablas y cuadros se senalan las localidades en donde se han encontrado casos humanos, reservorios no humanos y transmisores. Se hacen comentários acerca de los resultados obtenidos y se seffala la importancia de incrementar los estúdios sobre enfermedades de Chagas en nuestro país.É a apresentação dos dados obtidos a partir de uma minuciosa revisão feita na literatura médica mexicana e estrangeira com relação à doença de Chagas no México. O estudo refere-se ao período de 1939 quando, pela primeira vez, menciona-se Trypanosoma cruzi no México, até 1976. Através de mapas, tabelas e quadros são mostrados os lugares onde foram encontrados casos humanos, reservatórios e transmissores. São feitos comentários sobre os resultados obtidos e é ressaltada a necessidade de ampliação dos estudos sobre a doença de Chagas no México.A thorough review of the literature is made regarding Chagas disease in Mexico and else- where since 1939, when Trypanosoma cruzi was first reported in this country until 1976. The location where human cases, non human reservoirs and transmitters have been found is pointed out by means of maps, tables and charts comments are made regarding the results reported. The importance of increasing the studies of Chagas' disease in our country is stressed.

  2. Beyond the sensorimotor plasticity: cognitive expansion of prism adaptation in healthy individuals.

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    Carine eMICHEL

    2016-01-01

    Full Text Available Sensorimotor plasticity allows us to maintain an efficient motor behavior in reaction to environmental changes. One of the classical models for the study of sensorimotor plasticity is prism adaptation. It consists of pointing to visual targets while wearing prismatic lenses that shift the visual field laterally. The conditions of the development of the plasticity and the sensorimotor after-effects have been extensively studied for more than a century. However, the interest taken in this phenomenon was considerably increased since the demonstration of neglect rehabilitation following prism adaptation by Rossetti and his colleagues in 1998. Mirror effects, i.e. simulation of neglect in healthy individuals, were observed for the first time by Colent and collaborators in 2000. The present review focuses on the expansion of prism adaptation to cognitive functions in healthy individuals during the last 15 years. Cognitive after-effects have been shown in numerous tasks even in those that are not intrinsically spatial in nature. Altogether, these results suggest the existence of a strong link between low-level sensorimotor plasticity and high-level cognitive functions and raise important questions about the mechanisms involved in producing unexpected cognitive effects following prism adaptation. Implications for the functional mechanisms and neuroanatomical network of prism adaptation are discussed to explain how sensorimotor plasticity may affect cognitive processes.

  3. Analytical models for the groundwater tidal prism and associated benthic water flux

    Science.gov (United States)

    King, Jeffrey N.; Mehta, Ashish J.; Dean, Robert G.

    2010-01-01

    The groundwater tidal prism is defined as the volume of water that inundates a porous medium, forced by one tidal oscillation in surface water. The pressure gradient that generates the prism acts on the subterranean estuary. Analytical models for the groundwater tidal prism and associated benthic flux are presented. The prism and flux are shown to be directly proportional to porosity, tidal amplitude, and the length of the groundwater wave; flux is inversely proportional to tidal period. The duration of discharge flux exceeds the duration of recharge flux over one tidal period; and discharge flux continues for some time following low tide. Models compare favorably with laboratory observations and are applied to a South Atlantic Bight study area, where tide generates an 11-m3 groundwater tidal prism per m of shoreline, and drives 81 m3 s −1 to the study area, which describes 23% of an observational estimate. In a marine water body, the discharge component of any oscillatory benthic water flux is submarine groundwater discharge. Benthic flux transports constituents between groundwater and surface water, and is a process by which pollutant loading and saltwater intrusion may occur in coastal areas.

  4. All-prism achromatic phase matching for tunable second-harmonic generation.

    Science.gov (United States)

    Richman, B A; Bisson, S E; Trebino, R; Sidick, E; Jacobson, A

    1999-05-20

    Achromatic phase matching (APM) involves dispersing the light entering a nonlinear optical crystal so that a wide range of wavelengths is simultaneously phase matched. We constructed an APM apparatus consisting of six prisms, the final dispersion angle of which was optimized to match to second order in wavelength the type I phase-matching angle of beta barium borate (BBO). With this apparatus, we doubled tunable fundamental light from 620 to 700 nm in wavelength using a 4-mm-long BBO crystal. An analogous set of six prisms after the BBO crystal, optimized to second order in second-harmonic wavelength, realigned the output second-harmonic beams. Computer simulations predict that adjustment of a single prism can compensate angular misalignment of any or all the prisms before the crystal, and similarly for the prisms after the crystal. We demonstrated such compensation with the experimental device. The simulations also indicate that the phase-matching wavelength band can be shifted and optimized for different crystal lengths.

  5. Fusional Vergence Detected by Prism Bar and Synoptophore in Chinese Childhood Intermittent Exotropia

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    Tao Fu

    2015-01-01

    Full Text Available Purpose. To measure the changes in fusional vergence in Chinese children with intermittent exotropia (IXT and the association with the control of IXT. Methods. Ninety-two patients with IXT (8–15 years old were compared with 86 controls. Exodeviation control was evaluated using the Revised Newcastle Control Score. Angle of deviation was measured using prism and alternate cover testing at distance and near. Fusional vergence was measured using prism bar and synoptophore. This study was registered with ChiCTR-RCC-13003920. Results. Using prism bar, convergence break points were lower whereas divergence break points were higher in children with IXT at distance (P<0.001 and near (P<0.001 compared with controls. There was no significant difference in mean divergence amplitudes between the two groups when testing using a synoptophore (P=0.53. In children with IXT, the distance between recovery point and break point in both convergence (distance: P=0.02; near: P=0.02 and divergence (distance: P<0.001; near: P<0.001 was larger than controls when detected by prism bar and synoptophore (convergence: P=0.005; divergence: P=0.006. Conclusions. Children with IXT have reduced convergence amplitudes as detected by both prism bar and synoptophore.

  6. [Transfusion transmission of Chagas disease in Honduras and other Central American countries].

    Science.gov (United States)

    Ponce, C

    1999-01-01

    The transmission of Trypanosoma cruzi through blood transfusion is the second most important way of acquiring Chagas disease. This form of transmission transcends the vectorial transmission in many geographical areas. Honduras has developed a successful program for the control of transfusional transmission, based on the serological screening of blood donors, which is supported by law, making it mandatory. This experience has been extended to other Central American countries, supported by PAHO. Actually in the framework of the Initiative of the Central American countries for the elimination of the transmission of Chagas disease, launched in 1997, the control of transfusional transmission is becoming a reality.

  7. Drug discovery for Chagas disease should consider Trypanosoma cruzi strain diversity

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    Bianca Zingales

    2014-09-01

    Full Text Available This opinion piece presents an approach to standardisation of an important aspect of Chagas disease drug discovery and development: selecting Trypanosoma cruzi strains for in vitro screening. We discuss the rationale for strain selection representing T. cruzi diversity and provide recommendations on the preferred parasite stage for drug discovery, T. cruzi discrete typing units to include in the panel of strains and the number of strains/clones for primary screens and lead compounds. We also consider experimental approaches for in vitro drug assays. The Figure illustrates the current Chagas disease drug-discovery and development landscape.

  8. Doença de Chagas em Lassance, MG: Reavaliação clínico-epidemiológica 90 anos após a descoberta de Carlos Chagas Chagas' disease in Lassance, Minas Gerais State: Clinical-epidemiological re-evaluation ninety years after the discovery by Carlos Chagas

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    João Carlos Pinto Dias

    2002-04-01

    Full Text Available Analisa-se a trajetória da doença de Chagas em Lassance (município da descoberta de Carlos Chagas entre 1.908 a 2.001, através de registros históricos e pesquisas atuais. O município foi importante foco da tripanossomíase entre Chagas e os anos 1.980, mercê de infestação significativa das casas por Panstrongylus megistus e, mais tarde, Triatoma infestans, espécies que foram eficazmente controladas, nos últimos 20 anos. Importante no passado, a infecção chagásica é hoje residual, com uma prevalência geral de 5,03% e afetando basicamente os grupos etários elevados, não se encontrando soropositivos abaixo dos 20 anos de idade. O perfil clínico-epidemiológico dos chagásicos detectados é o habitual de áreas com transmissão interrompida, com a maioria dos casos em formas cardíacas benignas ou na forma crônica indeterminada, havendo ainda indicativos de formas digestivas, sendo a mortalidade ainda significativa, em grupos etários elevados. O município apresenta-se infestado por T. sordida, em baixas densidades e grande dispersão, não infectado por T. cruzi e restrito ao peridomicílio. Conclui-se que Lassance está hoje livre da transmissão da doença, devendo manter-se sob vigilância epidemiológica frente aos triatomíneos nativos no município e garantir-se a atenção médica às pessoas infectadas no passado.The history and present situation of Chagas' disease in Lassance (the county where Carlos Chagas discovered American trypanosomiasis were studied through a historical analysis and clinical and epidemiological research performed from 1999 to 2001. Lassance was an important focus of Chagas' disease from Carlos Chagas up until the 1980's, because of intensive infestation in dwellings by Panstrongylus megistus and Triatoma infestans, two important species which were efficiently controlled in the last twenty years. Human Chagas' disease was important in the past but today is only residual, affecting basically the

  9. Técnica do xenodiagnostico na molestia de Chagas

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    Emmanuel Dias

    1940-01-01

    Full Text Available O xenodiagnostico é um processo muito valioso para o diagnostico etiologico da moléstia de Chagas. Consiste em alimentar-se barbeiros normais em supótos portadores da infecção e determinar-se, depois, si eles adquirem ou não o parasitismo. Em cada região deve ser empregada, de preferência, o transmissor local mais importante. Três a seis ninfas famintas são geralmente empregadas em cada prova, devendo ficar em contacto com o doador até encherem-se completamente (15-30 minutos. Si o exame de fezes – espontaneamente eliminadas ou obtidas por punção anal – não revelar a presença de flagelados, os insetos devem ser dissecados 40 a 60 dias depois da sucção, para exame do conteúdo duodenal.Xenodiagnosis is a very valuable method for the etiological diagnosis of Chagas’s disease. It consists in allowing the clean insect transmitter to feed upon the suspected carrier, and in ascertaining whether the bugs become infected. The principal local vector is the most suitable species to be used in a given region. Three to six hungry nymphs are usually employed in each test and must feed until repletion (15-30 minutes. It flagellates are not detected in the faeces or in the rectal contents, obtained by anal puncture, insects are dissected 40-60 days after the and the duodenal contents is examined.

  10. Community Participation in Chagas Disease Vector Surveillance: Systematic Review

    Science.gov (United States)

    Abad-Franch, Fernando; Vega, M. Celeste; Rolón, Miriam S.; Santos, Walter S.; Rojas de Arias, Antonieta

    2011-01-01

    Background Vector control has substantially reduced Chagas disease (ChD) incidence. However, transmission by household-reinfesting triatomines persists, suggesting that entomological surveillance should play a crucial role in the long-term interruption of transmission. Yet, infestation foci become smaller and harder to detect as vector control proceeds, and highly sensitive surveillance methods are needed. Community participation (CP) and vector-detection devices (VDDs) are both thought to enhance surveillance, but this remains to be thoroughly assessed. Methodology/Principal Findings We searched Medline, Web of Knowledge, Scopus, LILACS, SciELO, the bibliographies of retrieved studies, and our own records. Data from studies describing vector control and/or surveillance interventions were extracted by two reviewers. Outcomes of primary interest included changes in infestation rates and the detection of infestation/reinfestation foci. Most results likely depended on study- and site-specific conditions, precluding meta-analysis, but we re-analysed data from studies comparing vector control and detection methods whenever possible. Results confirm that professional, insecticide-based vector control is highly effective, but also show that reinfestation by native triatomines is common and widespread across Latin America. Bug notification by householders (the simplest CP-based strategy) significantly boosts vector detection probabilities; in comparison, both active searches and VDDs perform poorly, although they might in some cases complement each other. Conclusions/Significance CP should become a strategic component of ChD surveillance, but only professional insecticide spraying seems consistently effective at eliminating infestation foci. Involvement of stakeholders at all process stages, from planning to evaluation, would probably enhance such CP-based strategies. PMID:21713022

  11. Insecticide resistance in vector Chagas disease: evolution, mechanisms and management.

    Science.gov (United States)

    Mougabure-Cueto, Gastón; Picollo, María Inés

    2015-09-01

    Chagas disease is a chronic parasitic infection restricted to America. The disease is caused by the protozoa Trypanosoma cruzi, which is transmitted to human through the feces of infected triatomine insects. Because no treatment is available for the chronic forms of the disease, vector chemical control represents the best way to reduce the incidence of the disease. Chemical control has been based principally on spraying dwellings with insecticide formulations and led to the reduction of triatomine distribution and consequent interruption of disease transmission in several areas from endemic region. However, in the last decade it has been repeatedly reported the presence triatomnes, mainly Triatoma infestans, after spraying with pyrethroid insecticides, which was associated to evolution to insecticide resistance. In this paper the evolution of insecticide resistance in triatomines is reviewed. The insecticide resistance was detected in 1970s in Rhodnius prolixus and 1990s in R. prolixus and T. infestans, but not until the 2000s resistance to pyrthroids in T. infestans associated to control failures was described in Argentina and Bolivia. The main resistance mechanisms (i.e. enhanced metabolism, altered site of action and reduced penetration) were described in the T. infestans resistant to pyrethrods. Different resistant profiles were demonstrated suggesting independent origin of the different resistant foci of Argentina and Bolivia. The deltamethrin resistance in T. infestans was showed to be controlled by semi-dominant, autosomally inherited factors. Reproductive and developmental costs were also demonstrated for the resistant T. infestans. A discussion about resistance and tolerance concepts and the persistence of T. infestans in Gran Chaco region are presented. In addition, theoretical concepts related to toxicological, evolutionary and ecological aspects of insecticide resistance are discussed in order to understand the particular scenario of pyrethroid

  12. Molecular epidemiology of human oral Chagas disease outbreaks in Colombia.

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    Juan David Ramírez

    Full Text Available BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, displays significant genetic variability revealed by six Discrete Typing Units (TcI-TcVI. In this pathology, oral transmission represents an emerging epidemiological scenario where different outbreaks associated to food/beverages consumption have been reported in Argentina, Bolivia, Brazil, Ecuador and Venezuela. In Colombia, six human oral outbreaks have been reported corroborating the importance of this transmission route. Molecular epidemiology of oral outbreaks is barely known observing the incrimination of TcI, TcII, TcIV and TcV genotypes. METHODOLOGY AND PRINCIPAL FINDINGS: High-throughput molecular characterization was conducted performing MLMT (Multilocus Microsatellite Typing and mtMLST (mitochondrial Multilocus Sequence Typing strategies on 50 clones from ten isolates. Results allowed observing the occurrence of TcI, TcIV and mixed infection of distinct TcI genotypes. Thus, a majority of specific mitochondrial haplotypes and allelic multilocus genotypes associated to the sylvatic cycle of transmission were detected in the dataset with the foreseen presence of mitochondrial haplotypes and allelic multilocus genotypes associated to the domestic cycle of transmission. CONCLUSIONS: These findings suggest the incrimination of sylvatic genotypes in the oral outbreaks occurred in Colombia. We observed patterns of super-infection and/or co-infection with a tailored association with the severe forms of myocarditis in the acute phase of the disease. The transmission dynamics of this infection route based on molecular epidemiology evidence was unraveled and the clinical and biological implications are discussed.

  13. Bragg prism monochromator and analyser for super ultra-small angle neutron scattering studies

    Indian Academy of Sciences (India)

    Apoorva G Wagh; Sohrab Abbas; Markus Strobl; Wolfgang Treimer

    2008-11-01

    We have designed, fabricated and operated a novel Bragg prism monochromator–analyser combination. With a judicious choice of the Bragg reflection, its asymmetry and the apex angle of the silicon single crystal prism, the monochromator has produced a neutron beam with sub-arcsec collimation. A Bragg prism analyser with the opposite asymmetry has been tailored to accept a still sharper angular profile. With this optimized monochromator–analyser pair, we have attained the narrowest and sharpest neutron angular profile to date. At this facility, we have recorded the first SUSANS spectra spanning wave vector transfers ∼ 10−6 Å-1 to characterize samples containing agglomerates up to tens of micrometres in size.

  14. Os experimentos prismáticos de Goethe Goethe's prismatic experiments

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    Fred Jordan

    1993-12-01

    Full Text Available O ensaio pretende estimular a realização de experimentos prismáticos com recursos muito simples e, com isso, facilitar o acesso aos fundamentais estudos de Goethe sobre cor, a "Farbenlehre". O encarte anexo contém fotos de um processo prismático complementar, produzido por Imagens-Modelo em Claro-Escuro neutro. Contém ainda fotos de imagens prismáticas produzidas por Imagens-Modelo em cores.The essay intends to stimulate the carrying out of prismatic experiments with very simple resources and, therewith, ease the access to Goethe's fundamental color studies, the "Farbenlehre". The included folder contains photographs of a complementary prismatic process produced by neutral bright-dark Model-Images. It also contains photographs of prismatic images produced by colored Model-Images.

  15. Molten-salt Synthesis and Properties of ZnS with Hexagonal Prism Morphology

    Institute of Scientific and Technical Information of China (English)

    LIU, Jin-Song; JI, Guang-Bin; LI, Zi-Quan; CAO, Jie-Ming; ZHENG, Ming-Bo; KE, Xing-Fei

    2007-01-01

    ZnS with hexagonal prism morphology has been synthesized successfully by molten-salt method with ZnS nanoparticles as precursors, and the ZnS nanoparticles were prepared by one-step solid-state reaction of Zn(CH3COO)2·2H2O with Na2S·9H2O at ambient temperature. Crystal structure and morphology of the product were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and HRTEM. Ultraviolet-visible optical absorption spectrum of the ZnS hexagonal prism shows a distinct red shift from that of bulk ZnS crystals and photoluminescence spectrum exhibits strong emissions at 380 and 500 nm, respectively. Further experiments were designed and the formation mechanism of the ZnS hexagonal prism has been also discussed in brief.

  16. Pathology of complete atrioventricular block in chronic chagas' myocarditis

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    Zilton A. Andrade

    1988-03-01

    Full Text Available Sclero-atrophy, fibrosis, vascular ectasia, phlebosclerosis and mild non-specific chronic inflammatory changes were observed in variable location and proportion involving the atrioventricular conducting tissue of the heart in five human cases of chronic Chagas' myocarditis associated with complete atrioventricular block. One case presented complete destruction of the A-V conduction system. In three cases the lesions were disseminated all along the conducting tissue but did not cause anywhere a complete disruption in the continuity of the system. The distal portion of the bundle branches were the most damaged sector of the system, exceptfor the fasciculi of the posterior division of the left bundle branch which were relatively preserved. One case exhibited bilateral sclero-atrophy of the bundle branches as the main change; and another showed early and mild fibrocalcific damage of the penetrating portion of the His bundle. The A-V node appeared as the least involved part of the conducting system in the cases studied. Demonstration of the lesions in this series of cases seems important because: a it reveals that complete atrioventriculr block in chronic Chagas' disease results from disseminated lesions and not from focal disruptive change as has been commonly observed in cases of other etiologies; b it shows that chronic inflammation can produce at the end variable and widespread vascular, degenerative andfibrotic alterations within the conducting tissue of the heart, which may lead to its total destruction.O estudo do sistema de condução atrioventricular através cortes seriados completos em cinco casos humanos de miocardite crônica chagásica e bloqueio A-V total revelou a presença de lesões de esclero-atrofia, fibrose, ectasia vascular, fleboesclerose e inflamação crônica inespeclfica envolvendo o sistema de maneira disseminada, mas com distribuição e intensidade variáveis de caso para caso. Em um caso, todo o sistema, do nódulo A

  17. Effects of aspirin-triggered resolvin D1 on peripheral blood mononuclear cells from patients with Chagas' heart disease.

    Science.gov (United States)

    Ogata, Haline; Teixeira, Maxelle Martins; Sousa, Rodrigo Cunha de; Silva, Marcos Vinícius da; Correia, Dalmo; Rodrigues Junior, Virmondes; Levy, Bruce David; Rogério, Alexandre de Paula

    2016-04-15

    Chagas disease is caused by Trypanosoma cruzi (T. cruzi). In some patients with Chagas disease, symptoms progress to chronic chagasic cardiomyopathy. Endogenously, inflammation is resolved in the presence of lipid mediators such as aspirin-triggered RvD1 (AT-RvD1) which has anti-inflammatory and pro-resolution effects. Here, we demonstrated, for the first time, the effects of AT-RvD1 on T. cruzi antigen-stimulated peripheral blood mononuclear cells (PBMCs) from patients with Chagas heart disease. The levels of IFN-γ, TNF-α, IL-10, and IL-13 increased in PBMCs from cardiac-form Chagas patients in stage B1 (patients with fewer heart abnormalities) stimulated with T. cruzi antigen compared to those in non-stimulated PBMCs. AT-RvD1 reduced the IFN-γ concentrations in PBMCs from patients with Chagas disease stimulated with T. cruzi antigen compared to stimulated with T. cruzi antigen cells. AT-RvD1 treatment resulted in no observable changes in TNF-α, IL-10, and IL-13 levels. AT-RvD1 significantly decreased the percentage of necrotic cells and caused a significant reduction in the proliferation rate of T. cruzi antigen-stimulated PBMCs from patients with Chagas disease. These findings demonstrate that AT-RvD1 modulates the immune response in Chagas disease patients and might have potential to be used as an alternative approach for slowing the development of further heart damage.

  18. Spherical lenses and prisms lead to postural instability in both dyslexic and non dyslexic adolescents.

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    Zoi Kapoula

    Full Text Available There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13-17 years-old and 11 non dyslexics (13-16 years-old participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of -1 diopter (ACCOM1 over each eye; viewing with -3 diopters over each eye (ACCOM3; viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the -1 lenses increased the surface of body sway significantly whereas the -3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum, was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to

  19. Comparação entre o reagente Chagas-latex e a imunofluorescência no diagnóstico sorológico da doença de Chagas na zona sul do Rio Grande do Sul

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    Giovanni Baruffa

    1973-10-01

    Full Text Available Os Autores submeteram 142 amostras de soros de casos agudos e crônicos de Doença de Chagas, já examinados com o Reagente Chagas-Latex, ao exame de Imunofluorescência, obtendo correspondência de resultados em 139 (97,9%. O alto índice de fidelidade, provavelmente devido à ausência na zona de doenças que possam proporcionar resultados falsamente positivos, fez do Reagente Chagas-Latex um método simples e fácil para a triagem sorológica nos casos suspeitos em zona endêmica.

  20. Quimioterapia da doença de Chagas: estado da arte e perspectivas no desenvolvimento de novos fármacos Chemotherapy of Chagas' disease: state of the art and perspectives for the development of new drugs

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    Luiz C. Dias

    2009-01-01

    Full Text Available Neglected diseases are a major global cause of illness, long-term disability and death. Chagas' disease is a parasitic infection widely distributed throughout Latin America, with devastating consequences in terms of human morbidity and mortality. The existing drug therapy suffers from a combination of drawbacks including poor efficacy, resistance and serious side effects. In 2009, we celebrate the 100th anniversary of the discovery of Chagas' disease, facing the challenges of developing new, safe and effective drugs for the treatment of this disease. This brief review attempts to highlight the state of the art, limitations and perspectives of Chagas' disease drug development.

  1. Novo procedimento de xenodiagnóstico na forma crônica da doença de Chagas New xenodiagnostic procedure in chronic Chagas' disease

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    Saulo P. Almeida

    1976-01-01

    Full Text Available Xenodiagnósticos feitos com Triatoma infestans durante 24 horas consecutivas, a intervalos de duas horas, demonstraram o Trypanosoma cruzi em 9 de 10 pacientes suspeitos de infecção chagástica crônica.Positive xenodiagnostic was obtained in 9 out of 10 chronic Chagas' disease patients on which triatoma infestans were allowed to feed at 2hr intervals along a period of 24hr.

  2. FC-TRIPLEX Chagas/Leish IgG1: a multiplexed flow cytometry method for differential serological diagnosis of chagas disease and leishmaniasis.

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    Andréa Teixeira-Carvalho

    Full Text Available Differential serological diagnosis of Chagas disease and leishmaniasis is difficult owing to cross-reactivity resulting from the fact that the parasites that cause these pathologies share antigenic epitopes. Even with optimized serological assays that use parasite-specific recombinant antigens, inconclusive test results continue to be a problem. Therefore, new serological tests with high sensitivity and specificity are needed. In the present work, we developed and evaluated the performance of a new flow cytometric serological method, referred to as FC-TRIPLEX Chagas/Leish IgG1, for the all-in-one classification of inconclusive tests. The method uses antigens for the detection of visceral leishmaniasis, localized cutaneous leishmaniasis, and Chagas disease and is based on an inverted detuned algorithm for analysis of anti-Trypanosomatidae IgG1 reactivity. First, parasites were label with fluorescein isothiocyanate or Alexa Fluor 647 at various concentrations. Then serum samples were serially diluted, the dilutions were incubated with suspensions of mixed labeled parasites, and flow cytometric measurements were performed to determine percentages of positive fluorescent parasites. Using the new method, we obtained correct results for 76 of 80 analyzed serum samples (95% overall performance, underscoring the outstanding performance of the method. Moreover, we found that the fluorescently labeled parasite suspensions were stable during storage at room temperature, 4 °C, and -20 °C for 1 year. In addition, two different lots of parasite suspensions showed equivalent antigen recognition; that is, the two lots showed equivalent categorical segregation of anti-Trypanosomatidae IgG1 reactivity at selected serum dilutions. In conclusion, we have developed a sensitive and selective method for differential diagnosis of Chagas disease, visceral leishmaniasis, and localized cutaneous leishmaniasis.

  3. A Novel Method for Heightening Sensitivity of Prism Coupler-Based SPR Sensor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-Wei; WEN Ting-Dun; WU Zhi-Fang

    2011-01-01

    We present a novel method for heightening the sensitivity of a prism coupler-based surface plasmon resonance (SPR) sensor. The method is based on the total reflection prism made of BK7 glass combined with the Kretschmann geometry of theattenuated total reflection (ATR) method. Compared to the conventional methods of prism coupler-based SPR the novel method provides higher semsitivity to the measurement system.Theoretical simulations show that the detetion sensitivity to the refractive index (RI) of the sensor based on the novel approach has a strong dependence on the thickness of the metal layer. The RI resolution of the sensor is predicted to be 8 × 107 refractive indox units (RIU) under the condition of optimum metal film thickness.This novel method can leave out a precision angle rotation device in the angle modulation and it is unnecessary to adjust the acceptance angle of the light detector. The principal advantage of this method over other methods of light intensity modulation based on prism coupler-based SPR is high sensitivity, expediency to measure and aplication of long distances.%@@ We present a novel method for heightening the sensitivity of a prism coupler-based surface plasmon resonance(SPR) sensor.The method is based on the total reflection prism made of BK7 glass combined with the Kretschmann geometry of theattenuated total reflection(ATR) method.Compared to the conventional methods of prism coupler-based SPR,the novel method provides higher sensitivity to the measurement system.Theoretical simulations show that the detection sensitivity to the refractive index(RI) of the sensor based on the novel approach has a strong dependence on the thickness of the metal layer.The RI resolution of the sensor is predicted to be 8 × 10-7 refractive index units(RIU) under the condition of optimum metal film thickness.This novel method can leave out a precision angle rotation device in the angle modulation and it is unnecessary to adjust the acceptance angle of

  4. Reconstruction of polygonal prisms from point-clouds of engineering facilities

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    Akisato Chida

    2016-10-01

    Full Text Available The advent of high-performance terrestrial laser scanners has made it possible to capture dense point-clouds of engineering facilities. 3D shape acquisition from engineering facilities is useful for supporting maintenance and repair tasks. In this paper, we discuss methods to reconstruct box shapes and polygonal prisms from large-scale point-clouds. Since many faces may be partly occluded by other objects in engineering plants, we estimate possible box shapes and polygonal prisms and verify their compatibility with measured point-clouds. We evaluate our method using actual point-clouds of engineering plants.

  5. Design of an Airborne Portable Remote Imaging Spectrometer (PRISM) for the Coastal Ocean

    Science.gov (United States)

    Mouroulis, P.; vanGorp, B.; Green, R. O.; Cohen, D.; Wilson, D.; Randall, D.; Rodriguez, J.; Polanco, O.; Dierssen, H.; Balasubramanian, K.; Vargas, R.; Hein, R.; Sobel, H.; Eastwood, M.

    2010-01-01

    PRISM is a pushbroom imaging spectrometer currently under development at the Jet Propulsion Laboratory, intended to address the needs of airborne coastal ocean science research. We describe here the instrument design and the technologies that enable it to achieve its distinguishing characteristics. PRISM covers the 350-1050 nm range with a 3.1 nm sampling and a 33(deg) field of view. The design provides for high signal to noise ratio, high uniformity of response, and low polarization sensitivity. The complete instrument also incorporates two additional wavelength bands at 1240 and 1610 nm in a spot radiometer configuration to aid with atmospheric correction.

  6. Evaluation of the Performance of Routine Information System Management (PRISM framework: evidence from Uganda

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    Aqil Anwer

    2010-07-01

    Full Text Available Abstract Background Sound policy, resource allocation and day-to-day management decisions in the health sector require timely information from routine health information systems (RHIS. In most low- and middle-income countries, the RHIS is viewed as being inadequate in providing quality data and continuous information that can be used to help improve health system performance. In addition, there is limited evidence on the effectiveness of RHIS strengthening interventions in improving data quality and use. The purpose of this study is to evaluate the usefulness of the newly developed Performance of Routine Information System Management (PRISM framework, which consists of a conceptual framework and associated data collection and analysis tools to assess, design, strengthen and evaluate RHIS. The specific objectives of the study are: a to assess the reliability and validity of the PRISM instruments and b to assess the validity of the PRISM conceptual framework. Methods Facility- and worker-level data were collected from 110 health care facilities in twelve districts in Uganda in 2004 and 2007 using records reviews, structured interviews and self-administered questionnaires. The analysis procedures include Cronbach's alpha to assess internal consistency of selected instruments, test-retest analysis to assess the reliability and sensitivity of the instruments, and bivariate and multivariate statistical techniques to assess validity of the PRISM instruments and conceptual framework. Results Cronbach's alpha analysis suggests high reliability (0.7 or greater for the indices measuring a promotion of a culture of information, RHIS tasks self-efficacy and motivation. The study results also suggest that a promotion of a culture of information influences RHIS tasks self-efficacy, RHIS tasks competence and motivation, and that self-efficacy and the presence of RHIS staff have a direct influence on the use of RHIS information, a key aspect of RHIS performance

  7. [Fresnel prisms--their value in the rehabilitation of homonymous hemianopsias].

    Science.gov (United States)

    Hedges, T R; Stunkard, J; Twer, A

    1988-05-01

    The use of press-on Fresnel prisms is described as a simple inexpensive technique to rehabilitate patients with homonymous hemianopsia. The optical principle of prismatic displacement from the blind to the seeing fields is detailed herein. Forty-one patients were evaluated over a 10 year period. Twenty per cent benefited from the prism. Many of those who found limited or little value from their use expressed appreciation that something had been tried in order to improve visual function. Those patients with good acuity and an otherwise normal neurological status are the best candidates. Proper motivation and instruction are essential.

  8. Quasi-Wollaston-Prism for Terahertz Frequencies Fabricated by 3D Printing

    Science.gov (United States)

    Hernandez-Serrano, A. I.; Castro-Camus, E.

    2017-01-01

    In this letter, we present the design, fabrication, and characterization of a quasi-Wollaston prism for terahertz frequencies based on form birefringence. The prism uses the birefringence induced in a sub-wavelength layered plastic-air structure that produces refraction in different directions for different polarizations. The component was simulated using the finite-difference-time-domain method, fabricated by 3D printing and subsequently tested by terahertz time-domain spectroscopy showing a polarization separation around of 23° for frequencies below 400 GHz, exhibiting cross polarization power extinction ratios better than 1.6 × 10-3 at 200 GHz.

  9. Further genetic characterization of the two Trypanosoma cruzi Berenice strains (Be-62 and Be-78) isolated from the first human case of Chagas disease (Chagas, 1909).

    Science.gov (United States)

    Cruz, R E; Macedo, A M; Barnabé, C; Freitas, J M; Chiari, E; Veloso, V M; Carneiro, C M; Bahia, M T; Tafuri, Washington L; Lana, M

    2006-03-01

    We describe here an extension of a previous genetic characterization of Trypanosoma cruzi strains (Be-62 and Be-78) isolated from the patient Berenice, the first human case of Chagas disease [Chagas, C., 1909. Nova Tripanomíase humana. Estudos sobre morfologia e o ciclo evolutivo do Schizotrypanum cruzi, n. gen., n. sp., agente etiolójico da nova entidade morbida do homem. Mem. Inst. Oswaldo Cruz 1, 159-218]. We wanted to verify the composition of T. cruzi populations originated from these two isolates. In the present work, 22 enzymatic loci (MLEE), nine RAPD primers and 7 microsatellite loci were analyzed. Clones from both strains were also characterized to verify whether these strains are mono or polyclonal. Be-62 and Be-78 strains were different in 3 out of 22 enzymatic systems, in 3 out of 9 RAPD primers tested and in all microsatellite loci investigated. However, our data suggests that both strains are phylogenetically closely related, belonging to genetic group 32 from Tibayrenc and Ayala [Tibayrenc, M., Ayala, F.J., 1988. Isoenzime variability in Trypanosoma cruzi, the agent of Chagas' disease: genetical, taxonomical, and epidemiological significance. Evolution 42, 277-292], equivalent to zymodeme 2 and T. cruzi II major lineage which, in Brazil, comprises parasites from the domestic cycle of the disease. Microsatellite analyses showed differences between the parental strains but suggested that both populations are monoclonal since each strain and their respective clones showed the same amplification products.

  10. Mode of death on Chagas heart disease: comparison with other etiologies. a subanalysis of the REMADHE prospective trial.

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    Silvia M Ayub-Ferreira

    Full Text Available Sudden death has been considered the main cause of death in patients with Chagas heart disease. Nevertheless, this information comes from a period before the introduction of drugs that changed the natural history of heart failure. We sought to study the mode of death of patients with heart failure caused by Chagas heart disease, comparing with non-Chagas cardiomyopathy.We examined the REMADHE trial and grouped patients according to etiology (Chagas vs non-Chagas and mode of death. The primary end-point was all-cause, heart failure and sudden death mortality; 342 patients were analyzed and 185 (54.1% died. Death occurred in 56.4% Chagas patients and 53.7% non-Chagas patients. The cumulative incidence of all-cause mortality and heart failure mortality was significantly higher in Chagas patients compared to non-Chagas. There was no difference in the cumulative incidence of sudden death mortality between the two groups. In the Cox regression model, Chagas etiology (HR 2.76; CI 1.34-5.69; p = 0.006, LVEDD (left ventricular end diastolic diameter (HR 1.07; CI 1.04-1.10; p<0.001, creatinine clearance (HR 0.98; CI 0.97-0.99; p = 0.006 and use of amiodarone (HR 3.05; CI 1.47-6.34; p = 0.003 were independently associated with heart failure mortality. LVEDD (HR 1.04; CI 1.01-1.07; p = 0.005 and use of beta-blocker (HR 0.52; CI 0.34-0.94; p = 0.014 were independently associated with sudden death mortality.In severe Chagas heart disease, progressive heart failure is the most important mode of death. These data challenge the current understanding of Chagas heart disease and may have implications in the selection of treatment choices, considering the mode of death.ClinicalTrials.gov NCT00505050 (REMADHE.

  11. Spatial patterns in discordant diagnostic test results for Chagas disease: links to transmission hotspots.

    Science.gov (United States)

    Levy, Michael Z; Bowman, Natalie M; Kawai, Vivian; Plotkin, Joshua B; Waller, Lance A; Cabrera, Lilia; Steurer, Frank; Seitz, Amy E; Pinedo-Cancino, Viviana V; Cornejo del Carpio, Juan Geny; Cordova Benzaquen, Eleazar; McKenzie, F Ellis; Maguire, James H; Gilman, Robert H; Bern, Caryn

    2009-04-15

    Diagnosis of Chagas disease is hindered by discordance between screening and confirmatory test results for Trypanosoma cruzi infection. In periurban Arequipa, Peru, spatial analysis revealed that individuals with discordant test results are spatially clustered in hotspots of T. cruzi transmission, suggesting that discordant results likely represent true infections in this setting.

  12. Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

    Science.gov (United States)

    Gonzalez-Mejia, Martha Elba; Torres-Rasgado, Enrique; Porchia, Leonardo M; Salgado, Hilda Rosas; Totolhua, José-Luis; Ortega, Arturo; Hernández-Kelly, Luisa Clara Regina; Ruiz-Vivanco, Guadalupe; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo

    2014-01-01

    Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels. PMID:24676665

  13. Science, health and development: Chagas disease in Brazil, 1943-1962.

    Science.gov (United States)

    Kropf, S Petraglia

    2005-12-01

    The present paper discusses the historical construction and legitimacy of Chagas disease as a distinct nosological entity and as a public health issue in Brazil. It focuses on the activities of a group of researchers from Oswaldo Cruz Institute who worked at the Centre for the Study and Prevention of Chagas disease, located in Bambuí, Minas Gerais. Led in the 1940s and 50s by Emmanuel Dias, disciple of Carlos Chagas, the group made important contributions to the clinical characterization of Chagas disease as a cardiac illness, established the fact that it was technically possible to control the disease by using residual insecticides, and engaged in intense political mobilization to have the disease included as part of the Health Ministry sanitation campaigns. My hypothesis is that the group's work was a determining factor in the overcoming of certain unresolved controversies that had surrounded the medical and social identity of the disease since the 1920s. I examine to what extent this process was directly linked both to post-war optimism over new possibilities of combating infectious diseases and to the national and international debate on the relation between health and economic and social development.

  14. Chronic phase of Chagas disease: why should it be treated? A comprehensive review

    Directory of Open Access Journals (Sweden)

    José Rodrigues Coura

    2011-09-01

    Full Text Available The pathogenesis and evolutive pattern of Chagas disease suggests that the chronic phase should be more widely treated in order to (i eliminate Trypanosoma cruzi and prevent new inflammatory foci and the extension of tissue lesions, (ii promote tissue regeneration to prevent fibrosis, (iii reverse existing fibrosis, (iv prevent cardiomyopathy, megaoesophagus and megacolon and (v reduce or eliminate cardiac block and arrhythmia. All cases of the indeterminate chronic form of Chagas disease without contraindications due to other concomitant diseases or pregnancy should be treated and not only cases involving children or recently infected cases. Patients with chronic Chagas cardiomyopathy grade II of the New York Heart Association classification should be treated with specific chemotherapy and grade III can be treated according to medical-patient decisions. We are proposing the following new strategies for chemotherapeutic treatment of the chronic phase of Chagas disease: (i repeated short-term treatments for 30 consecutive days and interval of 30-60 days for six months to one year and (ii combinations of drugs with different mechanisms of action, such as benznidazole + nifurtimox, benznidazole or nifurtimox + allopurinol or triazole antifungal agents, inhibition of sterol synthesis.

  15. [Serologic study of the diagnosis of Chagas disease in Nicaraguan students in the Juventud island].

    Science.gov (United States)

    Montes de Oca, N V; Cabrera Alonso, C; Martínez, R; Cantelar de Francisco, N; Pérez Insueta, O

    1989-01-01

    The results obtained during the serologic study for the diagnosis of Chagas' disease in 868 Nicaraguan students in the Isle of Youth are reported. Qualitative hemagglutination and indirect immunofluorescence were used. It was found that 8.5% of these students showed antibodies specific to Trypanosoma cruzi by means of this diagnostic test.

  16. Situação atual da doença de Chagas na Guiana Francesa

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    Philippe Esterre

    1987-09-01

    Full Text Available Localizada entre dois focos endêmicos da doença de Chagas, a Venezuela e o Brasil, a Guiana Francesa conheceu poucos casos dessa afecção de 1940 até 1956. Um inquérito sorológico, utilizando-se uma pesquisa ativa sobre pacientes cardiopáticos e uma pesquisa passiva, permitiu evidenciar a existência de dois casos autóctones. Apesar da presença de vetores domésticos, o risco da doença de Chagas na Guiana Francesa parece limitado à aparição episódica de escassos casos humanos.Although located between two endemic areas of Chagas' disease (Venezuela and Brazil, French Guiana recorded only few cases of this infection between 1940 and 1956. A serological survey, using either active detection in cardiopathic patients or a passive one resulted in the finding of two autochthonous cases. In spite ofthe presence of a peridomiciliary cycle the risk of Chagas' disease in French Guiana seems to be limited to the episodic occurrence of rare sporadic human cases.

  17. ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

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    Iván Darío BRAVO-TOBAR

    2015-10-01

    Full Text Available SUMMARY Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA and C-reactive protein serum levels (CRP in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35, II (n = 29, and III (n = 18. A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease.

  18. Chagas' Disease and HIV Co-infection: Genotypic Characterization of the Trypanosoma cruzi Strain

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    Pacheco Raquel S

    1998-01-01

    Full Text Available In the past few years, new aspects of the immunopathology of Chagas' disease have been described in immunosuppressed patients, such as fatal central nervous system lesions related to the reactivation of the parasite. This article is the first description of the genotypic characterization, at the strain level, of Trypanosoma cruzi isolated from a patient with Chagas` disease/AIDS co-infection. The presence of four hypodense lesions was observed in the cranial compute tomographic scan. The diagnosis of AIDS was assessed by the detection of anti-HIV antibodies using enzyme-linked immunosorbent assay (ELISA and Western blot techniques. The CD4+ lymphocyte counts were maintained under 200 cells/mm3 during one year demonstrating the severity of the state of immunosuppression. Chagas' disease was confirmed by serological and parasitological methods. Trypomastigote forms were visualized in a thick blood smear. The parasite isolated is genotypically similar to the CL strain. The paper reinforces that cerebral Chagas' disease can be considered as another potential opportunistic infection in AIDS resulting from the reactivation of a dormant T. cruzi infection acquired years earlier.

  19. Chagas Disease in Mexico: Report of 14 Cases of Chagasic Cardiomyopathy in Children.

    Science.gov (United States)

    Salazar-Schettino, Paz María; Cabrera-Bravo, Margarita; Vazquez-Antona, Clara; Zenteno, Edgar; Alba-Alvarado, Mariana De; Gutierrez, Elia Torres; Gomez, Yolanda Guevara; Perera-Salazar, María Gabriela; Torre, Guadalupe Garcia de la; Bucio-Torres, Martha Irene

    2016-01-01

    Chagas disease is a parasitic infection mainly found in Latin America; it is transmitted by a triatomine, also known as assassin bug or kissing bug. In humans, the parasite causes mostly cardiac disorders. Two-thirds of the Mexican territory are regarded as risk areas for vector transmission of Trypanosoma cruzi, the causal agent. The parasite can be found as a blood-borne trypomastigote or as an intracellular amastigote. The progression and severity of lesions could be due to frequent reinfections or to infection by highly virulent strains. A total of 3,327 individuals younger than 18 years old, living in risk areas for this disease in the rural setting of the States of Queretaro, San Luis Potosi, and Veracruz, underwent a seroepidemiological study. Among them, 37 subjects were seropositive for T. cruzi, and were studied to look for signs of cardiac pathology, which has only been reported in adults. A clinical record was prepared for all included individuals, and electrocardiography (ECG) and echocardiography (ECHO) studies were performed; 25 cases showed lesions compatible with the onset of Chagas cardiomyopathy. The other 12 patients showed either normal ECG and ECHO data or showed abnormal parameters that were not regarded as significant. Lesions found in the onset of Chagas cardiomyopathy in children are herein reported, along with 14 cases of cardiac pathology compatible with Chagas disease. Our results indicate that patients younger than 18 years can show a cardiac pathology similar to that observed in adults.

  20. Chagas' disease: study of congenital transmission in cases of acute maternal infection

    Directory of Open Access Journals (Sweden)

    Moretti Edgardo

    2005-01-01

    Full Text Available We studied three pregnant women with acute chagasic infection. Two patients, infected in the third trimester of pregnancy, had uninfected children. The third patient, infected earlier, had an infected newborn. These results encourage research on risk factors of transmission and on medical decisions concerning pregnant women with acute Chagas' disease.

  1. Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

    Directory of Open Access Journals (Sweden)

    Martha Elba Gonzalez-Mejia

    2014-04-01

    Full Text Available Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO, has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf, infected N-monomethyl-L-arginine treated (Inf L-NAME, non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001. In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels.

  2. ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

    Science.gov (United States)

    BRAVO-TOBAR, Iván Darío; NELLO-PÉREZ, Carlota; FERNÁNDEZ, Alí; MOGOLLÓN, Nora; PÉREZ, Mary Carmen; VERDE, Juan; CONCEPCIÓN, Juan Luis; RODRIGUEZ-BONFANTE, Claudina; BONFANTE-CABARCAS, Rafael

    2015-01-01

    SUMMARY Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA) and C-reactive protein serum levels (CRP) in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35), II (n = 29), and III (n = 18). A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease. PMID:26603224

  3. The endless race between Trypanosoma cruzi and host immunity: lessons for and beyond Chagas disease.

    Science.gov (United States)

    Junqueira, Caroline; Caetano, Braulia; Bartholomeu, Daniella C; Melo, Mariane B; Ropert, Catherine; Rodrigues, Maurício M; Gazzinelli, Ricardo T

    2010-09-15

    Infection with the protozoan parasite Trypanosoma cruzi, the agent of Chagas disease, is characterised by a variable clinical course - from symptomless cases to severe chronic disease with cardiac and/or gastrointestinal involvement. The variability in disease outcome has been attributed to host responses as well as parasite heterogeneity. In this article, we review studies indicating the importance of immune responses as key determinants of host resistance to T. cruzi infection and the pathogenesis of Chagas disease. Particular attention is given to recent studies defining the role of cognate innate immune receptors and immunodominant CD8+ T cells that recognise parasite components - both crucial for host-parasite interaction and disease outcome. In light of these studies we speculate about parasite strategies that induce a strong and long-lasting T-cell-mediated immunity but at the same time allow persistence of the parasite in the vertebrate host. We also discuss what we have learned from these studies for increasing our understanding of Chagas pathogenesis and for the design of new strategies to prevent the development of Chagas disease. Finally, we highlight recent studies employing a genetically engineered attenuated T. cruzi strain as a vaccine shuttle that elicits potent T cell responses specific to a tumour antigen and protective immunity against a syngeneic melanoma cell line.

  4. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches.

    Science.gov (United States)

    Noya, Belkisyolé Alarcón de; Díaz-Bello, Zoraida; Colmenares, Cecilia; Ruiz-Guevara, Raiza; Mauriello, Luciano; Muñoz-Calderón, Arturo; Noya, Oscar

    2015-05-01

    Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana's signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission.

  5. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches

    Directory of Open Access Journals (Sweden)

    Belkisyolé Alarcón de Noya

    2015-05-01

    Full Text Available Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas with 249 cases (73.5% children and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana’s signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission.

  6. Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects.

    Science.gov (United States)

    Dumonteil, Eric; Bottazzi, Maria Elena; Zhan, Bin; Heffernan, Michael J; Jones, Kathryn; Valenzuela, Jesus G; Kamhawi, Shaden; Ortega, Jaime; Rosales, Samuel Ponce de Leon; Lee, Bruce Y; Bacon, Kristina M; Fleischer, Bernhard; Slingsby, B T; Cravioto, Miguel Betancourt; Tapia-Conyer, Roberto; Hotez, Peter J

    2012-09-01

    Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

  7. Assessment of Galectin-3 Polymorphism in Subjects with Chronic Chagas Disease

    Directory of Open Access Journals (Sweden)

    Gabriela da Silva Cruz

    2015-11-01

    Full Text Available AbstractBackground:Galectin-3, a β-galactoside binding lectin, has been described as a mediator of cardiac fibrosis in experimental studies and as a risk factor associated with cardiovascular events in subjects with heart failure. Previous studies have evaluated the genetic susceptibility to Chagas disease in humans, including the polymorphisms of cytokine genes, demonstrating correlations between the genetic polymorphism and cardiomyopathy development in the chronic phase. However, the relationship between the galectin-3 single nucleotide polymorphism (SNP and phenotypic variations in Chagas disease has not been evaluated.Objective:The present study aimed to determine whether genetic polymorphisms of galectin-3 may predispose to the development of cardiac forms of Chagas disease.Methods:Fifty-five subjects with Chagas disease were enrolled in this observational study. Real-time polymerase chain reaction (PCR was used for genotyping the variants rs4644 and rs4652 of the galectin-3 gene.Results:For the SNP rs4644, the relative risk for the cardiac form was not associated with the genotypes AA (OR = 0.79, p = 0.759, AC (OR = 4.38, p = 0.058, or CC (OR = 0.39, p = 0.127. Similarly, for the SNP rs4652, no association was found between the genotypes AA (OR = 0.64, p = 0.571, AC (OR = 2.85, p = 0.105, or CC (OR = 0.49, p = 0.227 and the cardiac form of the disease.Conclusion:Our results showed no association between the different genotypes for both SNPs of the galectin-3 gene and the cardiac form of Chagas disease. (Arq Bras Cardiol. 2015; [online].ahead print, PP.0-0

  8. PRISM, a Novel Visual Metaphor Measuring Personally Salient Appraisals, Attitudes and Decision-Making: Qualitative Evidence Synthesis.

    Directory of Open Access Journals (Sweden)

    Tom Sensky

    Full Text Available PRISM (the Pictorial Representation of Illness and Self Measure is a novel, simple visual instrument. Its utility was initially discovered serendipitously, but has been validated as a quantitative measure of suffering. Recently, new applications for different purposes, even in non-health settings, have encouraged further exploration of how PRISM works, and how it might be applied. This review will summarise the results to date from applications of PRISM and propose a generic conceptualisation of how PRISM works which is consistent with all these applications.A systematic review, in the form of a qualitative evidence synthesis, was carried out of all available published data on PRISM.Fifty-two publications were identified, with a total of 8254 participants. Facilitated by simple instructions, PRISM has been used with patient groups in a variety of settings and cultures. As a measure of suffering, PRISM has, with few exceptions, behaved as expected according to Eric Cassell's seminal conceptualisation of suffering. PRISM has also been used to assess beliefs about or attitudes to stressful working conditions, interpersonal relations, alcohol consumption, and suicide, amongst others.This review supports PRISM behaving as a visual metaphor of the relationship of objects (eg 'my illness' to a subject (eg 'myself' in a defined context (eg 'my life at the moment'. As a visual metaphor, it is quick to complete and yields personally salient information. PRISM is likely to have wide applications in assessing beliefs, attitudes, and decision-making, because of its properties, and because it yields both quantitative and qualitative data. In medicine, it can serve as a generic patient-reported outcome measure. It can serve as a tool for representational guidance, can be applied to developing strategies visually, and is likely to have applications in coaching, psychological assessment and therapeutic interventions.

  9. RECUERDO DEL DESCUBRIMIENTO DE LA ENFERMEDAD DE CHAGAS

    Directory of Open Access Journals (Sweden)

    Hernando Groot Liévano

    2016-12-01

    Full Text Available A través de mis largos años, he vivido en el trópico y he visto el sufrimiento de nuestros campesinos por esta grave dolencia y, a la par que he sido testigo de tal situación, he presenciado también los esfuerzos extraordinarios realizados en Colombia para su estudio y para su control, que a todos nos deben enorgullecer. Estos fueron hechos en épocas recientes por personas como Augusto Corredor, Felipe Guhl y muchos otros investigadores que sería muy dispendioso enumerar. Años atrás, los nombres de Benjamín Otálora, Hernando Ucrós y especialmente Santiago Rengifo y César Uribe Piedrahita tienen que venir a nuestra mente. Santiago Rengifo, investigador infatigable de la enfermedad, fue además creador del Instituto Roberto Franco de Villavicencio y uno de los artífices más importantes de la Facultad de Medicina de la Universidad del Valle. A César Uribe Piedrahita, se debe el haber iniciado el interés en Colombia por el estudio de esta parasitosis; fue él quien identificó por primera vez el agente causal en nuestro país. Así mismo, formó un sinnúmero de investigadores que, con sus estudios, han dado luz sobre la dolencia y han sido lustre para la ciencia en América Latina. César Uribe Piedrahita, mi profesor y luego mi amigo, es una de las personas de la medicina nacional que se debe exaltar con más vehemencia porque era el individuo que no solamente dominaba el campo médico, sino que, como un Pico de la Mirándola del siglo XX, era experto en antropología, en arqueología, en botánica, habilísimo pintor y tallista, propulsor de las investigaciones sobre las bondades de las plantas, así como escritor de primera línea y dotado de excepcionales cualidades docentes para inculcar en sus estudiantes la disciplina por el estudio y la necesidad de trabajar cada vez más por este país. Parece oportuno que en estos momentos, al rememorar a Carlos Chagas, se haga un breve recuento de aquellas condiciones en las cuales se

  10. Active control of flow around a square prism by slot jet injection

    Directory of Open Access Journals (Sweden)

    Hacıalioğulları M.

    2013-04-01

    Full Text Available The main aim of the experimental study is to determine both the most effective injection surface and rate in order to ensure minimum drag and fluctuating forces on a square prism subjected to crossflow. All predetermined jet injection surfaces i.e. front, side, and rear, tested separately for injection ratios of IR = 0, 1, 1.5, 2 at Reynolds number of Re = 16,000. Surface pressures were measured by differential pressure transducer whereas instantaneous velocity measurements were performed by using multichannel Constant Temperature Anemometer (CTA. It was concluded that jet injection, especially from the rear surface, brought noticeable improvements to the flow characteristics of a square prism. For rear jet configuration with IR = 1.5, the mean drag coefficient (CDT¯$overline {{C_{{m{DT}}}}} $ was reduced to 79.4% and CP RMS level on side surfaces was reduced to 20% of that of the single square prism. In addition, instantaneous flow visualization photographs and Strouhal number (St distribution across the injection ratio were also presented to identify the flow patterns and underlying mechanism of drag and fluctuating force reduction of square prism with rear jet configuration.

  11. Development and application of GIS-based PRISM integration through a plugin approach

    Science.gov (United States)

    Lee, Woo-Seop; Chun, Jong Ahn; Kang, Kwangmin

    2014-05-01

    A PRISM (Parameter-elevation Regressions on Independent Slopes Model) QGIS-plugin was developed on Quantum GIS platform in this study. This Quantum GIS plugin system provides user-friendly graphic user interfaces (GUIs) so that users can obtain gridded meteorological data of high resolutions (1 km × 1 km). Also, this software is designed to run on a personal computer so that it does not require an internet access or a sophisticated computer system. This module is a user-friendly system that a user can generate PRISM data with ease. The proposed PRISM QGIS-plugin is a hybrid statistical-geographic model system that uses coarse resolution datasets (APHRODITE datasets in this study) with digital elevation data to generate the fine-resolution gridded precipitation. To validate the performance of the software, Prek Thnot River Basin in Kandal, Cambodia is selected for application. Overall statistical analysis shows promising outputs generated by the proposed plugin. Error measures such as RMSE (Root Mean Square Error) and MAPE (Mean Absolute Percentage Error) were used to evaluate the performance of the developed PRISM QGIS-plugin. Evaluation results using RMSE and MAPE were 2.76 mm and 4.2%, respectively. This study suggested that the plugin can be used to generate high resolution precipitation datasets for hydrological and climatological studies at a watershed where observed weather datasets are limited.

  12. Systematic comparisons between PRISM version 1.0.0, BAP, and CSMIP ground-motion processing

    Science.gov (United States)

    Kalkan, Erol; Stephens, Christopher

    2017-02-23

    A series of benchmark tests was run by comparing results of the Processing and Review Interface for Strong Motion data (PRISM) software version 1.0.0 to Basic Strong-Motion Accelerogram Processing Software (BAP; Converse and Brady, 1992), and to California Strong Motion Instrumentation Program (CSMIP) processing (Shakal and others, 2003, 2004). These tests were performed by using the MatLAB implementation of PRISM, which is equivalent to its public release version in Java language. Systematic comparisons were made in time and frequency domains of records processed in PRISM and BAP, and in CSMIP, by using a set of representative input motions with varying resolutions, frequency content, and amplitudes. Although the details of strong-motion records vary among the processing procedures, there are only minor differences among the waveforms for each component and within the frequency passband common to these procedures. A comprehensive statistical evaluation considering more than 1,800 ground-motion components demonstrates that differences in peak amplitudes of acceleration, velocity, and displacement time series obtained from PRISM and CSMIP processing are equal to or less than 4 percent for 99 percent of the data, and equal to or less than 2 percent for 96 percent of the data. Other statistical measures, including the Euclidian distance (L2 norm) and the windowed root mean square level of processed time series, also indicate that both processing schemes produce statistically similar products.

  13. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

    NARCIS (Netherlands)

    André, Philippe; Baccigalupi, Carlo; Banday, Anthony; Barbosa, Domingos; Barreiro, Belen; Bartlett, James; Bartolo, Nicola; Battistelli, Elia; Battye, Richard; Bendo, George; Benoît, Alain; Bernard, Jean-Philippe; Bersanelli, Marco; Béthermin, Matthieu; Bielewicz, Pawel; Bonaldi, Anna; Bouchet, François; Boulanger, François; Brand, Jan; Bucher, Martin; Burigana, Carlo; Cai, Zhen-Yi; Camus, Philippe; Casas, Francisco; Casasola, Viviana; Castex, Guillaume; Challinor, Anthony; Chluba, Jens; Chon, Gayoung; Colafrancesco, Sergio; Comis, Barbara; Cuttaia, Francesco; D'Alessandro, Giuseppe; Da Silva, Antonio; Davis, Richard; de Avillez, Miguel; de Bernardis, Paolo; de Petris, Marco; de Rosa, Adriano; de Zotti, Gianfranco; Delabrouille, Jacques; Désert, François-Xavier; Dickinson, Clive; Diego, Jose Maria; Dunkley, Joanna; Enßlin, Torsten; Errard, Josquin; Falgarone, Edith; Ferreira, Pedro; Ferrière, Katia; Finelli, Fabio; Fletcher, Andrew; Fosalba, Pablo; Fuller, Gary; Galli, Silvia; Ganga, Ken; García-Bellido, Juan; Ghribi, Adnan; Giard, Martin; Giraud-Héraud, Yannick; Gonzalez-Nuevo, Joaquin; Grainge, Keith; Gruppuso, Alessandro; Hall, Alex; Hamilton, Jean-Christophe; Haverkorn, Marijke; Hernandez-Monteagudo, Carlos; Herranz, Diego; Jackson, Mark; Jaffe, Andrew; Khatri, Rishi; Kunz, Martin; Lamagna, Luca; Lattanzi, Massimiliano; Leahy, Paddy; Lesgourgues, Julien; Liguori, Michele; Liuzzo, Elisabetta; Lopez-Caniego, Marcos; Macias-Perez, Juan; Maffei, Bruno; Maino, Davide; Mangilli, Anna; Martinez-Gonzalez, Enrique; Martins, Carlos J. A. P.; Masi, Silvia; Massardi, Marcella; Matarrese, Sabino; Melchiorri, Alessandro; Melin, Jean-Baptiste; Mennella, Aniello; Mignano, Arturo; Miville-Deschênes, Marc-Antoine; Monfardini, Alessandro; Murphy, Anthony; Naselsky, Pavel; Nati, Federico; Natoli, Paolo; Negrello, Mattia; Noviello, Fabio; O'Sullivan, Créidhe; Paci, Francesco; Pagano, Luca; Paladino, Rosita; Palanque-Delabrouille, Nathalie; Paoletti, Daniela; Peiris, Hiranya; Perrotta, Francesca; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Pollo, Agnieszka; Ponthieu, Nicolas; Remazeilles, Mathieu; Ricciardi, Sara; Roman, Matthieu; Rosset, Cyrille; Rubino-Martin, Jose-Alberto; Salatino, Maria; Schillaci, Alessandro; Shellard, Paul; Silk, Joseph; Starobinsky, Alexei; Stompor, Radek; Sunyaev, Rashid; Tartari, Andrea; Terenzi, Luca; Toffolatti, Luigi; Tomasi, Maurizio; Trappe, Neil; Tristram, Matthieu; Trombetti, Tiziana; Tucci, Marco; Van de Weijgaert, Rien; Van Tent, Bartjan; Verde, Licia; Vielva, Patricio; Wandelt, Ben; Watson, Robert; Withington, Stafford

    2014-01-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations

  14. Tilting double-prism scanner driven by cam-based mechanism.

    Science.gov (United States)

    Li, Anhu; Yi, Wanli; Sun, Wansong; Liu, Liren

    2015-06-20

    A pair of orthogonal tilting prisms has been explored in our previous work to perform the orientation and position tracking function with tracking accuracy better than submicroradian order. Crucial to the function implementation, however, is the real-time nonlinear control of the tilting angles of double prisms for tracking a given target trajectory. In previous papers [Proc. SPIE5892, 1-5 (2005).PSISDG0277-786X; Appl. Opt.45, 8063 (2006).PSISDG0277-786X; Proc. SPIE6709, 41 (2007).PSISDG0277-786X; Appl. Opt.51, 356 (2011).10.1364/AO.51.000356APOPAI1559-128X; Appl. Opt.53, 3712 (2014).10.1364/AO.53.003712APOPAI1559-128X], a new driving method by a cam-based mechanism, which can transfer the control problem to the design of corresponding cam configuration, is investigated. The design process of a cam-based mechanism is explained from the mapping relation between the tilting angles of a prism and the configuration curve of a corresponding cam. Based on the designed cam-based mechanism, a tracking error less than 0.375% is depicted between the tracking trajectory and the original one. Moreover, the dynamic characteristic of the tracking mechanism is discussed in detail as well as the impacts of different tilting speeds on the tracking trajectory. The proposed tracking mechanism of a tilting double-prism scanner can create a new avenue for passively tracking a given target.

  15. High-speed phase-shifting interferometry using triangular prism for time-resolved temperature measurement.

    Science.gov (United States)

    Shoji, Eita; Komiya, Atsuki; Okajima, Junnosuke; Kawamura, Hiroshi; Maruyama, Shigenao

    2015-07-10

    This study proposes a high-speed phase-shifting interferometer with an original optical prism. This phase-shifting interferometer consists of a polarizing Mach-Zehnder interferometer, an original optical prism, a high-speed camera, and an image-processing unit for a three-step phase-shifting technique. The key aspect of the application of the phase-shifting technique to high-speed experiments is an original prism, which is designed and developed specifically for a high-speed phase-shifting technique. The arbaa prism splits an incident beam into four output beams with different information. The interferometer was applied for quantitative visualization of transient heat transfer. In order to test the optical system for measuring high-speed phenomena, the temperature during heat conduction was measured around a heated thin tungsten wire (diameter of 5 μm) in water. The visualization area is approximately 90  μm×210  μm, and the spatial resolution is 3.5 μm at 300,000 fps of the maximum temporal resolution with a high-speed camera. The temperature fields around the heated wire were determined by converting phase-shifted data using the inverse Abel transform. Finally, the measured temperature distribution was compared with numerical calculations to validate the proposed system; a good agreement was obtained.

  16. Empirical relationship between inlet cross-sectional area and tidal prism: A re-evaluation

    NARCIS (Netherlands)

    Stive, M.J.F.; Ji, L.; Brouwer, R.L.; Van de Kreeke, J.; Ranasinghe, R.W.M.R.J.B.

    2010-01-01

    The well-known empirical relationship between the equilibrium cross-sectional area of tidal inlet entrances (A) and the tidal prism (P), first developed by O’Brien (1931), has been extensively reviewed. Our theoretical investigations indicate that a unique A-P relationship should only be expected fo

  17. Economic assessment of S-prism including development and generating costs

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, Ch.E. [GE Nuclear Energy San Jose (United States)

    2001-07-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. S-PRISM retains all of the key ALMR (advanced liquid metal reactor) design features including passive reactor shutdown, passive shutdown heat removal, and passive reactor cavity cooling that were developed under an earlier DOE program. Key factors that make S-PRISM competitive include: 1) The use of passive safety systems that eliminate the need for diesel generators and hardened active heat sinks to assure that sufficient heat is removed from the core, reactor, and containment systems following design and beyond design basis events. 2) A seven point advantage in the plant capacity factor (93 versus 86%) over a single large plant. 3) A much shorter construction schedule (45%) made possible by a modular design that allows near parallel (sequenced) construction of three relatively small, simple factory fabricated NSSSs instead of one large complex NSSS. This paper describes the approach, methods, and results of an in-depth economic assessment of S-PRISM. The assessment found that the generation cost from an NOAK plant would be less than 3 cents/kW-hr and that a design certification could be obtained in less than 15 years at a cost of 2.1 billion dollars. (authors)

  18. On the Orchard crossing number of prisms, ladders and other related graphs

    CERN Document Server

    Feder, Elie

    2011-01-01

    This paper deals with the Orchard crossing number of some families of graphs which are based on cycles. These include disjoint cycles, cycles which share a vertex and cycles which share an edge. Specifically, we focus on the prism and ladder graphs.

  19. Concerted Breaking of Two Hydrogen Bonds in Water Hexamer Prism Revealed from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Richardson, Jeremy O.; Perez, Cristobal; Lobsiger, Simon; Reid, Adam A.; Temelso, Berhane; Shields, George C.; Kisiel, Zbigniew; Wales, David J.; Pate, Brooks; Althorpe, Stuart C.

    2016-06-01

    Over the past few years, we have used H218O water substitution to determine the structures of water clusters by molecular rotational spectroscopy. In the case of the water hexamer, the energy difference between the cage and prism structures is calculated to be about 0.1 kcal/mol and this energy difference is of the order of the zero-point energy variation between the isomers. Using rotational spectroscopy we provided experimental evidence for three isomers, i.e, cage, prism and book and established their relative energy ordering. In the special case of the prism hexamer, cluster dynamics causes measurable splitting in rotational transitions resulting from tunneling between discernible equivalent minima. Multiple isotopic substitution measurements involving all 64 possible isotopologues of the water hexamer prism (H218O)n(H216O)6-n were performed in order to identify the water molecules involved in the tunneling motion. The analysis of these tunneling-rotation spectra suggests that there are two distinct tunneling paths that involve concerted motion of two water molecules, implying a prototype scenario involving the breaking of two hydrogen bonds. C. Pérez, et al, Science. 2012, 336 897-901 J. O. Richardson et al, Science. 2016, in press

  20. Understanding University Reform in Japan through the Prism of the Social Sciences

    Science.gov (United States)

    Goodman, Roger

    2008-01-01

    This article looks at current university reforms in Japan through two slightly different social science prisms: how social science methodologies and theories can help us understand those reforms better and how social science teaching in universities will be affected by the current reform processes. (Contains 3 tables and 7 notes.)

  1. Follow-Up of Online Instruction: Effectiveness of Peer Coaching Seminar Course. PRISM Technical Report.

    Science.gov (United States)

    Hornberger, Breann

    This paper presents an evaluation of the Peer Coaching Seminar Course offered through the Peer Coaching Rural Inservice Model (PRISM) project at the North Dakota Center for Persons with Disabilities. This online course was designed to help rural teachers learn both peer coaching and classroom management skills. Twenty first- or second-year…

  2. Islamic Exorcism and the Cinema Fist: Analyzing Exorcism Among Danish Muslims through the Prism of Film

    DEFF Research Database (Denmark)

    Suhr, Christian

    2017-01-01

    In this paper I apply film theory as a prism through which to examine the ritual mechanisms of neo-orthodox Islamic practices of spirit exorcism. I show how Islamic exorcisms operate as a ritual montage that conjures the absent-presence of al-ghayb—a hidden world of power that only God can see...

  3. [Investigation of vectors and reservoirs in an acute Chagas outbreak due to possible oral transmission in Aguachica, Cesar, Colombia].

    Science.gov (United States)

    Soto, Hugo; Tibaduiza, Tania; Montilla, Marleny; Triana, Omar; Suárez, Diana Carolina; Torres Torres, Mariela; Arias, María Teresa; Lugo, Ligia

    2014-04-01

    Colombia recorded 11 cases of acute Chagas disease and 80 cases of oral contamination with Trypanosoma cruzi. The current study analyzes the entomological and parasitological characteristics of the outbreak in Aguachica, Cesar Department, in 2010. An interdisciplinary group of health professionals and regional university personnel conducted the laboratory tests in the patients and the investigation of the transmission focus. Eleven cases of acute Chagas diseases were detected in a single family in a dwelling with domiciliated triatomines and Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus, and two Didelphis marsupialis opossums infected with T. cruzi in Attalea butyracea and Elaeis oleifera palm trees in the urban area of Aguachica. The study analyzes the role of R. pallescens and palm trees in the wild cycle of T. cruzi and in oral transmission of Chagas disease. Sporadic incursions by wild R. pallescens, P. geniculatus, and E. cuspidatus from the nearby palm trees into human dwellings may cause increasingly frequent outbreaks of oral Chagas disease.

  4. Hemocultures for the parasitological diagnosis of human chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    Egler Chiari

    1989-03-01

    Full Text Available With the purpose of standardization of an hemoculture technique presenting a higher positive rate in the parasitological diagnosis of chronic Chagas' disease in patients with reactive serology (IFT, HA, CFT the following schedule was used. Thirty ml of venous blood was collected with heparin and the plasma was separated by centrifugation (2.000 rpm/30'. The packed cells were washed with LIT medium or PBS which was then removed by centrifugation (2.000 rpm/15'. This material was sampled in 6 screw-tubes 18x200 with 6 ml of LIT medium and incubated at 28°C. These incubated cultures at 28°C were examined after 15, 30, 45 and 60 days. When the hemoculture was not immediately processed after blood collection, the plasma was removed and the sediment enriched with LIT medium and preserved at 4°C. The Xenodiagnosis was performed according to Schenones method used here as a reference technique. Among the various groups of patients examined by both techniques the best results obtained were: 55.08% ofpositivity for hemocultures against 27.5% forxenodiagnosis (X² = 4.54, p = 0.05, with a tubepositivity of 26.6%. Recommendation for screening trials of drug assays is the repetition of method on a same patient 2 or more times in different occasions, as used in xenodiagnosis.Objetivando a padronização de uma técnica de hemoculturas que apresente maior taxa de positividade no diagnóstico da fase crônica da doença de Chagas em pacientes com sorologia reativa (TIF, HA, RFC utilizamos o seguinte esquema: o volume de 30ml de sangue foi colhido heparinizado e o plasma separado por centrifugaçao (200 rpm/30'; o sedimento foi lavado com meio LIT ou salina fisiológica tamponada e removido por nova centrifugação (2000 rpm/15; as células sedimentadas foram distribuídas em 6 tubos tipo "screw" 18 x 200 contendo 6,0 ml de meio LIT; as culturas incubadas a 28°C, foram examinadas após 15, 30, 45 e 60 dias; quando a hemocultura não foi processada

  5. The Personalized Reminder Information and Social Management System (PRISM) Trial: Rationale, Methods and Baseline Characteristics

    Science.gov (United States)

    Czaja, Sara J.; Boot, Walter R.; Charness, Neil; Rogers, Wendy; Sharit, Joseph; Fisk, Arthur D.; Lee, Chin Chin; Nair, Sankaran N.

    2014-01-01

    Technology holds promise in terms of providing support to older adults. To date there have been limited robust systematic efforts to evaluate the psychosocial benefits of technology for older people and identify factors that influence both the usability and uptake of technology systems. In response to these issues we developed the Personal Reminder Information and Social Management System (PRISM), a software application designed for older adults to support social connectivity, memory, knowledge about topics, leisure activities and access to resources. This trail is evaluating the impact of access to the PRISM system on outcomes such as social isolation, social support and connectivity. This paper reports on the approach used to design the PRISM system, study design, methodology and baseline data for the trial. The trial is multi-site randomized field trial. PRISM is being compared to a Binder condition where participants received a binder that contained content similar to that found on PRISM. The sample includes 300 older adults, aged 65 – 98 years, who lived alone and at risk for being isolated. The primary outcome measures for the trial include indices of social isolation and support and well-being. Secondary outcomes measures include indices of computer proficiency, technology uptake and attitudes towards technology. Follow-up assessments occurred at 6 and 12 months post-randomization. The results of this study will yield important information about the potential value of technology for older adults. The study also demonstrates how a user-centered iterative design approach can be incorporated into the design and evaluation of an intervention protocol. PMID:25460342

  6. Illusory reversal of causality between touch and vision has no effect on prism adaptation rate

    Directory of Open Access Journals (Sweden)

    Hirokazu eTanaka

    2012-12-01

    Full Text Available Learning, according to Oxford Dictionary, is to gain knowledge or skill by studying, from experience, from being taught, etc. In order to learn from experience, the central nervous system has to decide what action leads to what consequence, and temporal perception plays a critical role in determining the causality between actions and consequences. In motor adaptation, causality between action and consequence is implicitly assumed so that a subject adapts to a new environment based on the consequence caused by her action. Adaptation to visual displacement induced by prisms is a prime example; the visual error signal associated with the motor output contributes to the recovery of accurate reaching, and a delayed feedback of visual error can decrease the adaptation rate. Subjective feeling of temporal order of action and consequence, however, can be modified or even reversed when her sense of simultaneity is manipulated with an artificially delayed feedback. Our previous study (Tanaka, Homma & Imamizu (2011 Exp Brain Res demonstrated that the rate of prism adaptation was unaffected when the subjective delay of visual feedback was shortened. This study asked whether subjects could adapt to prism adaptation and whether the rate of prism adaptation was affected when the subjective temporal order was illusory reversed. Adapting to additional 100 ms delay and its sudden removal caused a positive shift of point of simultaneity in a temporal-order judgment experiment, indicating an illusory reversal of action and consequence. We found that, even in this case, the subjects were able to adapt to prism displacement with the learning rate that was statistically indistinguishable to that without temporal adaptation. This result provides further evidence to the dissociation between conscious temporal perception and motor adaptation.

  7. The personalized reminder information and social management system (PRISM) trial: rationale, methods and baseline characteristics.

    Science.gov (United States)

    Czaja, Sara J; Boot, Walter R; Charness, Neil; A Rogers, Wendy; Sharit, Joseph; Fisk, Arthur D; Lee, Chin Chin; Nair, Sankaran N

    2015-01-01

    Technology holds promise in terms of providing support to older adults. To date, there have been limited robust systematic efforts to evaluate the psychosocial benefits of technology for older people and identify factors that influence both the usability and uptake of technology systems. In response to these issues, we developed the Personal Reminder Information and Social Management System (PRISM), a software application designed for older adults to support social connectivity, memory, knowledge about topics, leisure activities and access to resources. This trail is evaluating the impact of access to the PRISM system on outcomes such as social isolation, social support and connectivity. This paper reports on the approach used to design the PRISM system, study design, methodology and baseline data for the trial. The trial is multi-site randomized field trial. PRISM is being compared to a Binder condition where participants received a binder that contained content similar to that found on PRISM. The sample includes 300 older adults, aged 65-98 years, who lived alone and at risk for being isolated. The primary outcome measures for the trial include indices of social isolation and support and well-being. Secondary outcomes measures include indices of computer proficiency, technology uptake and attitudes towards technology. Follow-up assessments occurred at 6 and 12 months post-randomization. The results of this study will yield important information about the potential value of technology for older adults. The study also demonstrates how a user-centered iterative design approach can be incorporated into the design and evaluation of an intervention protocol.

  8. Formas encefalopaticas de enfermedad de Chagas cronica observadas en Argentina Encephalopathic form of chronic Chagas' disease observed in Argentine

    Directory of Open Access Journals (Sweden)

    Miguel Eduardo Jorg

    1981-12-01

    Full Text Available Se describen las características clínicas y las manifestaciones dominantes en 22 enfermos observados entre 1963 y 1978 sobre un total de 420 con neuropatías diversas examinados en el area central Norte de la Argentina; afectados por una encefalopatía crónica, que, por hallazgos de laboratorio (demostración del parasito en sangre o en su defecto confirmacion por mas de una prueba serológica positiva y por las correlaciones anatomoclínicas, puede ser imputada a la infección por el Trypanosoma cruzi. En la mitad o mas de los enfermos, son salientes las siguientes manifestaciones: disprosexia y confusión en 81,8%; cefalea y confusión en 72,7%; debilitamiento de reflejos músculo-tendinosos y trastornos del lenguaje en 63,6%; dispraxias en 59%; trastornos de la marcha y crisis mioclónicas en 54,5%; bradicinesias en 50%. En menor escala se encontraron: parestesias, ideas delirantes, perturbaciones cerebelares, crisis de vertigo, diplopia, lipotimias,humor fluctuante. Las menos frecuentes: disautonomia y excitacion. En 8 se hallaron evidencias semiologicas de cardiopatias y en 2 de compromiso digestivo grosero. Se analiza el alcance de esta casuistica en relación a los hallazgos anatomopatológicos en casos mortales y con referencia a lo ya conocido sobre la forma neuropatologica de la enfermedad de Chagas cronica.Among 420 patientes found with diverse subacute and chronic neuropathies, 22 were diagnosed as cases of true trypanosomic encephalopathy by means of the demonstration of parasites in blood (by xenodiagnosis or hemoculture or through serologic tests. In 50% or more of those patientes, following semiologic elements were prevalente: dysprosexia and depression in 81.8%; cephalea and confusion in 72.7%; weakness of muscular-tendineous reflexes and speech disturbance in 63.6% dispraxies in 59.0%; disturbances of gait and myoclonic crises in 54.5%; bradikinesias in 59.0%. Other symptoms were verified in a mirror scale: paresias

  9. The Role of Gender in Chagas Disease Prevention and Control in Honduras: An Analysis of Communication and Collaboration Networks.

    Science.gov (United States)

    Triana, Diana Rocío Rodríguez; Mertens, Frédéric; Zúniga, Concepción Valeriano; Mendoza, Yolanda; Nakano, Eduardo Yoshio; Monroy, Maria Carlota

    2016-09-01

    In Honduras, where Chagas disease is a serious health and environmental concern, prevention measures face the challenge of achieving widespread and long-term sustainable adoption by communities. The article integrates social network analysis and a gender-sensitive approach to understand the role of men and women in the implementation of a community-level intervention, based on the adoption of housing improvements to reduce the presence of the insect vector. A total of 108 people in the community of El Salitre were interviewed. Data were collected on socio-demographic characteristics, participation in project activities, communication and collaboration networks related to Chagas disease prevention, knowledge of Chagas disease, and adoption of housing improvements techniques. Communication mostly occurred between the same gender individuals and was associated with knowledge of Chagas disease. Socioeconomic status, Chagas disease knowledge, and collaboration with men were associated with women adopting housing improvements. For men, however, participation in project activities, formal education, and collaboration with women were associated with adoption. These findings suggest that men and women were driven by distinct concerns, interests, and motivations when adopting new Chagas disease prevention strategies. Participatory community interventions that seek to generate health knowledge and foster collaborations to reduce health risk should address gender differences.

  10. Seroepidemiological and clinical study of Chagas' disease in Nicaragua Estudio seroepidemiológico y clínico de la enfermedad de Chagas en Nicaragua

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    Teresa Rivera B

    1995-06-01

    Full Text Available With the aim of determining the prevalence, immunological profile, and knowing the electrocardiographic alterations, a clinical and Seroepidemiological study of Chagas' disease was performed in three rural settlements located at the North, East and West of Nicaragua. Anti T. cruzi antibodies were searched by indirect immunofluorescence (IFI and hemagglutination (IHA in a total of 803 subjects. Seropositives and the same number of seronegatives, matched by age and sex, were included in a case-control design for the electrocardiographic assessment. Antibody prevalence was 13.1, 4.3 and 3.2% in the respective settlements. In the first two the immunological profile corresponds to that of an endemic zone of long standing, were transmission has decreased, and in the third the pattern is of a zone under control. Electrocardiographic changes compatible with Chagas' disease were found in seropositive individuals, but difference with control group was not statistically significant. It is concluded that the disease is endemic in the three settlements and the clinical aspect requires further evaluation, including additional cardiologic techniques.Con el objetivo de determinar la prevalencia, perfil inmunológico de la población y conocer las alteraciones electrocardiográficas; se realizó un estudio seroepidemiológico y clínico de la enfermedad de Chagas en tres localidades ubicadas al Norte, Oriente y Occidente de Nicaragua. Como muestra se tomó suero a 803 personas, a las que se les realizó busqueda de anticuerpos anti T. cruzi por Inmunofluorescencia (IFI y Hemaglutinación Indirecta (HAI. Al total de los pacientes de dos de éstas localidades que resultaron con serología positiva, se les evaluó por electrocardiografía, estableciendo un grupo control con seronegativos con las mismas características de edad y sexo. La prevalencia de anticuerpos fué de 13.1, 4.3, y 3.2% en las tres localidades respectivamente. En las dos primeras el perfil

  11. Chagas' disease in the Brazilian Amazon: I - a short review Doença de Chagas na Amazônia Brasileira: I. revisão

    Directory of Open Access Journals (Sweden)

    José Rodrigues Coura

    1994-08-01

    Full Text Available At least eighteen species of triatominae have been found in the Brazilian Amazon, nine of them naturally infected with Trypanosoma cruzi or "cruzi-like" trypanosomes and associated with numerous wild reservoirs. Despite the small number of human cases of Chagas' disease described to date in the Brazilian Amazon the risk that the disease will become endemic in this area is increasing for the following reasons: a uncontrolled deforestation and colonization altering the ecological balance between reservoir hosts and wild vectors; b the adaptation of reservoir hosts of T.cruzi and wild vectors to peripheral and intradomiciliary areas, as the sole feeding alternative; c migration of infected human population from endemic areas, accompanied by domestic reservoir hosts (dogs and cats or accidentally carrying in their baggage vectors already adapted to the domestic habitat. In short, risks that Chagas' disease will become endemic to the Amazon appear to be linked to the transposition of the wild cycle to the domestic cycle in that area or to transfer of the domestic cycle from endemic areas to the Amazon.Pelo menos dezoito espécies de triatomíneos foram encontradas na Amazônia brasileira, nove das quais infectadas com Trypanosoma cruzi ou semelhante ("cruzi-like", associadas com numerosos reservatórios silvestres. A despeito do pequeno número de casos humanos da doença de Chagas descritos até agora na Amazônia brasileira, o risco que essa doença se torne endêmica é cada vez maior, pelas seguintes razões: a desmatamentos e colonização descontrolados, alterando o balanço entre reservatórios e vetores; b adaptação de reservatórios e vetores silvestres com T.cruzi ao peridomicílio, como única alternativa alimentar; c migração de populações humanas infectadas com T.cruzi acompanhadas de reservatórios domésticos (cães e gatos ou de vetores de suas regiões de origem na bagagem, já adaptados ao domicílio. Em resumo, o risco de que

  12. [Carlos Chagas Filho: an articulator of the history of sciences in Brazil].

    Science.gov (United States)

    Domingues, Heloisa Maria Bertol

    2012-06-01

    A letter sent in 1982 by a group of scientists to the president of Conselho Nacional de Desenvolvimento Científico e Tecnológico appealed for a policy of preservation of Brazilian scientific culture. The name of Carlos Chagas Filho topped the list of signatures thereby proving his commitment to that proposal, the ideological structure of which was part of his experience in scientific policy in Brazil and abroad. This document harks back to the practice of the history of the sciences in Brazil and the creation of places for the safeguard and organization of scientific memory, such as the Museu de Astronomia e Ciências Afins, Casa de Oswaldo Cruz and the Sociedade Brasileira de História da Ciência, of which Carlos Chagas Filho was an inaugural member of the board of directors.

  13. [Urbanization of Chagas disease in Peru: experiences in prevention and control].

    Science.gov (United States)

    Náquira, César

    2014-04-01

    In Peru, Chagas disease has an epidemiological significance in three macro-regions, one of them is the southern macro-region formed by the departments of Arequipa, Moquegua and Tacna. In 1965 a successful control was performed by house spraying insecticides, however, the persistence of the vector made it necessary for a second control plan that was implemented in 2000 and followed the guidelines of CONAL Plan, based on the elimination of Triatoma infestans and screening in blood banks.This plan was successful in Tacna and Moquegua, therefore these departments were considered free of vectorial transmission by the Pan American Health Organization. A ssimilar situation has not been achieved in the department of Arequipa because of the presence, among other factors, of rural migration to the city, in this way the urbanization of Chagas disease is a new epidemiological scenario of which we need to know more.

  14. [Vectorial transmission of Chagas' disease in Mulungu do Morro, Northeastern of Brazil].

    Science.gov (United States)

    Aras, Roque; Gomes, Irênio; Veiga, Marielza; Melo, Ailton

    2003-01-01

    A serological survey was carried out to determine the prevalence of Chagas' disease in municipality. The following variables were analyzed to identify the form of transmission of this disease: age, sex, clinical and transfusional history, degree of kinship and serology. Within the 863 municipalities we studied, we identified 265 individuals, with serology testing done on them and on their respective mothers. Of these, 232 tested negative serology for Chagas'disease and 33 (14.2%) positive. We found 9 (3.9%) patients, of 14.3 years. average age with vectorial transmission and 24 (10.3%), of 26.6 years. average age with probable, vertical and vectorial transmission. When we compare the two groups in regard to age averages and manner of transmission of Trypanosoma cruzi, we encounter a statistical significance. Our results suggest the existence of an active, vectorial transmission of Trypanosoma cruzi in Mulungu do Morro.

  15. Doença de Chagas por transfusão de sangue em Londrina

    Directory of Open Access Journals (Sweden)

    José Luis da Silveira Baldy

    1978-11-01

    Full Text Available The author emphasizes the importance of Chagas'disease transmited by blood transfusion in Brazil, and particularly in North region of Parana State. One serological survey for American Trypanosomiasis performed in two blood banks (4,500 blood donor candidates of tondrina, Parana State, Brazil, showed positive results in 7.4%. Six cases of acute pos-transfusion Oiagas'disease diagnosed in Londrina are presented. Two patients died and the further four cases were treated with nifurtimox, with good clinical response. The author points out the discrepancy between the small number of reported Ctiagas'disease acute cases and the high prevalence of positive serologic reactions fort his infection in donor candidates of blood hanks in Brazil He emphasizes the importance, in this country, of blood transfusion as infectious source of Trypanosoma cnizi, and remembers rules to follow when it will be necessary to use blood transfusions in countries where Chagas'disease is endemic. The early administration of trypanosomicidal drugs is mandatory, in cases of acute post-transfusion Chagas 'disease, eventually diagnosed.Nesta pesquisa apresenta-se o resultado de inquérito sorológien realizado em 1975, em dois bancos de sangue de Londrina-Paraná, e os primeiros seis casos agudos de doença de Chagas pós-transfusional, diagnosticados no Paraná Chama-se a atenção para a importância, no Brasil e, em particular, no Norte do Paraná, da doença de Chagas transmitida por transfusão de sangue. Reações sorológicas para o diagnóstico de tripanosomiase americana foram positivas em 7,4% dos 4.500 candidatos a doadores examinados nos dois bancos de sangue estudados. Seis casos de doença de Chagas aguda pós-transfusional - um prócer dente de Cianorte, outro de Cornélio Procópio e os demais de Londrina, estado do Paraná, foram diagnosticados. Dois dos pacientes faleceram e os outros quatro foram tratados com nifurtimox. Enfatiza-se a discrepância entre o

  16. [Progress towards the interruption of transmission of Chagas disease in the southern countries].

    Science.gov (United States)

    Moncayo, A

    1999-01-01

    The epidemiological and entomological data and the trends observed in the decreasing of the incidence of infection in young age groups indicate that only ninety years after the discovery of Chagas disease, the control of vectorial and transfusional transmission has reduced the incidence by 70% in the Southern Cone countries (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay). This has been accomplished thanks to the political and financial engagement of the concerned governments who have invested US$340 millions since 1991 to the present. The initiatives to interrupt transmission of Chagas in the Andean countries and the Central American countries have begun their activities in 1997 and the evolution of the control operations allows to forecast the complete interruption in these areas before the year 2010 to comply with the mandate of Resolution WHA. 52.14 of the World Health Assembly in May 1998.

  17. Interferon-γ and other inflammatory mediators in cardiomyocyte signaling during Chagas disease cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    Ludmila; Rodrigues; Pinto; Ferreira; Amanda; Farage; Frade; Monique; Andrade; Baron; Isabela; Cunha; Navarro; Jorge; Kalil; Christophe; Chevillard; Edecio; Cunha-Neto

    2014-01-01

    Chagas disease cardiomyopathy(CCC), the main consequence of Trypanosoma cruzi(T.cruzi) infection, is an inflammatory cardiomyopathy that develops in up to 30% of infected individuals. The heart inflammation in CCC patients is characterized by a Th1 T cell-rich myocarditis with increased production of interferon(IFN)-γ, produced by the CCC myocardial infiltrate and detected at high levels in the periphery. IFN-γ has a central role in the cardiomyocyte signaling during both acute and chronic phases of T.cruzi infection. In this review, we have chosen to focus in its pleiotropic mode of action during CCC, which may ultimately be the strongest driver towards pathological remodeling and heart failure. We describe here the antiparasitic protective and pathogenic dual role of IFN-γ in Chagas disease.

  18. Circadian entrainment by light and host in the Chagas disease vector, Triatoma infestans.

    Science.gov (United States)

    Valentinuzzi, Verónica Sandra; Amelotti, Ivana; Gorla, David Eladio; Catalá, Silvia Susana; Ralph, Martin Roland

    2014-03-01

    Triatoma infestans (Reduviidae: Triatominae, "kissing bug") is the main insect vector of Trypanosoma cruzi, the causative agent of Chagas disease, a chronic trypanosomiasis infecting 10 million people world-wide. This hematophagous bug feeds on diurnal and nocturnal species during each host's quiescent time. As the hosts are also its major predators, kissing bugs are subjected to dual selective pressures from a single source. Therefore, synchronization of feeding with the host's behavior is critical to the insects' survival. We show that nonphotic signals linked to the host eclipse the role of light and dark as the primary circadian zeitgeber for these bugs, although light still strongly inhibits locomotor behavior directly. In nature, this combination provides the insect with great flexibility in organizing physiology and behavior: anticipating a quiescent host or avoiding its potential predation while remaining directly responsive to immediate environmental conditions. Manipulation of nonphotic entrainment could be a useful chronobiotic tool in the control of Chagas disease.

  19. Estado actual de nuestros conocimientos sobre la enfermedad de chagas en la Republica Mexicana

    Directory of Open Access Journals (Sweden)

    Jorge Tay

    1981-06-01

    Full Text Available Se presentan los datos obtenidos de la revisión minuciosa en relación a enfermedad de Chagas de la literatura médica de la República Mexicana y extranjera desde el afio de 1939 en que por primeira vez se reporta a Trypanosoma cruzi en México, hasta el ano de 1976. Mediante mapas, tablas y cuadros se senalan las localidades en donde se han encontrado casos humanos, reservorios no humanos y transmisores. Se hacen comentários acerca de los resultados obtenidos y se seffala la importancia de incrementar los estúdios sobre enfermedades de Chagas en nuestro país.

  20. Massive right-sided cardiac thrombosis in Chagas' heart disease without left ventricular dysfunction.

    Science.gov (United States)

    Bestetti, Reinaldo B; Corbucci, Hélio A R; Cardinalli-Neto, Augusto

    2011-02-01

    A 63-year-old woman with the diagnosis of mega-oesophagus secondary to chronic Chagas' disease and no past cardiac history was referred for cardiac evaluation. The resting ECG showed right bundle-branch block, whereas a 2-D echocardiogram revealed marked right ventricular dilatation with hypokinesia, right atrial dilatation, normal pulmonary artery pressure, and normal left ventricular ejection fraction. A large, irregularly shaped mass, arising from the right atrium and protruding into the right ventricle through the tricuspid valve, with several different bizarre forms inside the right atrium during systole and/or diastole was seen on 2-D echocardiogram. Therefore, massive right-sided thrombosis can be detected in Chagas' disease patients with no overt right- and left-sided ventricular failure.

  1. Population differentiation of the Chagas disease vector Triatoma maculata (Erichson, 1848) from Colombia and Venezuela.

    Science.gov (United States)

    Monsalve, Yoman; Panzera, Francisco; Herrera, Leidi; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-06-01

    The emerging vector of Chagas disease, Triatoma maculata (Hemiptera, Reduviidae), is one of the most widely distributed Triatoma species in northern South America. Despite its increasing relevance as a vector, no consistent picture of the magnitude of genetic and phenetic diversity has yet been developed. Here, several populations of T. maculata from eleven Colombia and Venezuela localities were analyzed based on the morphometry of wings and the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene sequences. Our results showed clear morphometric and genetic differences among Colombian and Venezuelan populations, indicating high intraspecific diversity. Inter-population divergence is suggested related to East Cordillera in Colombia. Analyses of other populations from Colombia, Venezuela, and Brazil from distinct eco-geographic regions are still needed to understand its systematics and phylogeography as well as its actual role as a vector of Chagas disease.

  2. [Epidemiologic knowledge and current situation of Chagas disease in the state of Jalisco, Mexico].

    Science.gov (United States)

    Lozano-Kasten, Felipe; Magallón-Gastélum, Ezequiel; Soto-Gutiérrez, Margarita; Kasten-Monges, Marina; Bosseno, Marie-France; Brenière, Simone Frédérique

    2008-01-01

    Chagas disease in the state of Jalisco, Mexico was described for the first time in 1967; however, knowledge on the disease remains in a slow process. Between 1967 and 2006, the disease was described in its acute and chronic forms. The vector species have been identified, and the parasite Trypanosoma cruzi has been isolated and genetically characterized. Also, the magnitude of the infection in humans has been determined through serological studies of different populations as well as of blood donors. The up-to-dateness of knowledge of the disease in the state of Jalisco, unveils a necessity of increased research on the epidemiology of Chagas disease as well as on clinical studies to assess the health of individuals and the populations.

  3. [Chagas' disease in patients in chronic hemodialysis. Prevalence and risk of transmission by blood transfusion].

    Science.gov (United States)

    Lorca, M; Lorca, E; Atías, A; Plubins, L

    1989-06-01

    A serologic study of Chagas disease was performed in 110 patients submitted to chronic hemodialisis and blood transfusions. Immunofluorescence antibody testing (IgG and IgM) was positive in 6 out of 62 patients receiving multiple blood transfusions (9.7%), but negative in all 48 subjects without transfusions. Thus, repeated blood transfusion is a significant risk for T cruzi infection in chronic hemodialized patients.

  4. A scientometric evaluation of the Chagas disease implementation research programme of the PAHO and TDR.

    Directory of Open Access Journals (Sweden)

    Ana Laura Carbajal-de-la-Fuente

    2013-11-01

    Full Text Available The Special Programme for Research and Training in Tropical Diseases (TDR is an independent global programme of scientific collaboration cosponsored by the United Nations Children's Fund, the United Nations Development Program, the World Bank, and the World Health Organization. TDR's strategy is based on stewardship for research on infectious diseases of poverty, empowerment of endemic countries, research on neglected priority needs, and the promotion of scientific collaboration influencing global efforts to combat major tropical diseases. In 2001, in view of the achievements obtained in the reduction of transmission of Chagas disease through the Southern Cone Initiative and the improvement in Chagas disease control activities in some countries of the Andean and the Central American Initiatives, TDR transferred the Chagas Disease Implementation Research Programme (CIRP to the Communicable Diseases Unit of the Pan American Health Organization (CD/PAHO. This paper presents a scientometric evaluation of the 73 projects from 18 Latin American and European countries that were granted by CIRP/PAHO/TDR between 1997 and 2007. We analyzed all final reports of the funded projects and scientific publications, technical reports, and human resource training activities derived from them. Results about the number of projects funded, countries and institutions involved, gender analysis, number of published papers in indexed scientific journals, main topics funded, patents inscribed, and triatomine species studied are presented and discussed. The results indicate that CIRP/PAHO/TDR initiative has contributed significantly, over the 1997-2007 period, to Chagas disease knowledge as well as to the individual and institutional-building capacity.

  5. Factores de riesgo asociadas a la enfermedad Chagas en comunidades rurales en Lara, Venezuela

    OpenAIRE

    Zully Briceño; Giampaolo Orlandoni; Elizabeth Torres; Alexander Mogollón; Juan Luis Concepción; Claudina Rodríguez-Bonfante C; Elis Aldana

    2014-01-01

    La reinfestación por vectores secundarios es un problema emergente para la transmisión de la enfermedad de Chagas. Objetivo: Realizar un análisis comparativo para determinar los factores de riesgo asociados a la seropositividad en humanos. Materiales y Métodos: Estudio ecoentomológico y seroepidemiológico realizado en dos comunidades del Estado Lara, infestadas por Triatoma maculata o Panstrongylus geniculatus. Resultados: Guariquito (bosque húmedo tropical templado intervenido para actividad...

  6. Chagas infection transmission control: situation of transfusional transmission in Brazil and other countries of Latin America

    OpenAIRE

    Helio Moraes-Souza

    1999-01-01

    The transmission of the transfusion-associated Chagas disease is an important mechanism of its dissemination in several Latin American countries. The transmission risk depends on five factors: prevalence of infection in blood donors, degree of serological coverage, sensibility of used tests, safety of obtained results and infection risk. The Southern Cone Iniciative set off by the Pan-American Health Organization, in 1991, is contributing to the implementation of blood law in each endemic cou...

  7. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    OpenAIRE

    Fabbro, Diana L.; Emmaria Danesi; Veronica Olivera; Maria Olenka Codebó; Susana Denner; Cecilia Heredia; Mirtha Streiger; Sergio Sosa-Estani

    2014-01-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment be...

  8. [Regression of acute Chagas cardiopathy in an infant with a suspected transfusion infection].

    Science.gov (United States)

    Gónzalez-Zambrano, H; Amador Mena, J E; Delgadillo Jaime, C B

    1999-01-01

    Chagas disease was described in Mexico by Mazzotti in 1940. Post-transfusional cases have not been described. We report proved case of acute chagasic cardiopathy in a nine months old infant with suspected transfusional infection during neonatal period. She was treated with nifurtimox with disappearance of parasites and regression of cardiopathy. She is asymptomatic nine years afterwards with normal growth and negative parasitology and serology.

  9. Chagas disease in an area of recent occupation in Cochabamba, Bolivia

    OpenAIRE

    Albarracin-Veizaga Hugo; Carvalho Maria Esther de; Nascimento Elvira M M do; Rodrigues Vera Lúcia C. C.; Casanova Cláudio; Barata José Maria S

    1999-01-01

    INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000), where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT) was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males) sel...

  10. Different infective forms trigger distinct immune response in experimental Chagas disease.

    OpenAIRE

    Vieira,PM.; Francisco, AF; Machado, EM; Nogueira, NC; Fonseca, KdaS; Reis, AB; Teixeira-Carvalho, A.; Martins-Filho, OA; Tafuri,WL; Carneiro, CM

    2012-01-01

    Although metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of pa...

  11. Transmisión de la enfermedad de Chagas por vía oral

    OpenAIRE

    TOSO M,ALBERTO; VIAL U,FELIPE; Galanti, Norbel

    2011-01-01

    The traditional transmission pathways of Chagas' disease are vectorial, transfusional, transplacental and organ transplantation. However, oral transmission is gaining importance. The first evidence of oral transmission was reported in Brazil in 1965. Nowadays the oral route is the transmission mode in 50% of cases in the Amazon river zone. Oral infection is produced by the ingestion of infected triatomine bugs or their feces, undercooked meat from infested host animals and food contaminated w...

  12. La enfermedad de Chagas ya no es tan exótica

    Centers for Disease Control (CDC) Podcasts

    2008-04-03

    Este podcast tiene el propósito de informar a los profesionales de la salud sobre la enfermedad de Chagas, su diagnóstico y tratamiento, así como orientar en la identificación de pacientes infectados.  Created: 4/3/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 4/9/2008.

  13. Efficacy of Lychnopholide Polymeric Nanocapsules after Oral and Intravenous Administration in Murine Experimental Chagas Disease.

    Science.gov (United States)

    de Mello, Carlos Geraldo Campos; Branquinho, Renata Tupinambá; Oliveira, Maykon Tavares; Milagre, Matheus Marques; Saúde-Guimarães, Dênia Antunes; Mosqueira, Vanessa Carla Furtado; Lana, Marta de

    2016-09-01

    The etiological treatment of Chagas disease remains neglected. The compounds available show several limitations, mainly during the chronic phase. Lychnopholide encapsulated in polymeric nanocapsules (LYC-NC) was efficacious in mice infected with Trypanosoma cruzi and treated by intravenous administration during the acute phase (AP). As the oral route is preferred for treatment of chronic infections, such as Chagas disease, this study evaluated the use of oral LYC-NC in the AP and also compared it with LYC-NC administered to mice by the oral and intravenous routes during the chronic phase (CP). The therapeutic efficacy was evaluated by fresh blood examination, hemoculture, PCR, and enzyme-linked immunosorbent assay (ELISA). The cure rates in the AP and CP were 62.5% and 55.6%, respectively, upon oral administration of LYC-poly(d,l-lactide)-polyethylene glycol nanocapsules (LYC-PLA-PEG-NC) and 57.0% and 30.0%, respectively, with LYC-poly-ε-caprolactone nanocapsules (LYC-PCL-NC). These cure rates were significantly higher than that of free LYC, which did not cure any animals. LYC-NC formulations administered orally during the AP showed cure rates similar to that of benznidazole, but only LYC-NC cured mice in the CP. Similar results were achieved with intravenous treatment during the CP. The higher cure rates obtained with LYC loaded in PLA-PEG-NC may be due to the smaller particle size of these NC and the presence of PEG, which influence tissue diffusion and the controlled release of LYC. Furthermore, PLA-PEG-NC may improve the stability of the drug in the gastrointestinal tract. This work is the first report of cure of experimental Chagas disease via oral administration during the CP. These findings represent a new and important perspective for oral treatment of Chagas disease.

  14. Community resilience and Chagas disease in a rural region of Mexico

    Directory of Open Access Journals (Sweden)

    José Antonio Santana Rangel

    2016-01-01

    Full Text Available ABSTRACT OBJECTIVE To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. METHODS Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi, symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan’s modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. RESULTS The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. CONCLUSIONS It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease.

  15. Exposure to Citral, Cinnamon and Ruda Disrupts the Life Cycle of a Vector of Chagas Disease

    OpenAIRE

    2007-01-01

    The main vector of Chagas disease in Venezuela was exposed to the odors of citral, cinnamon and ruda. Cinnamon was found to stop the life cycle of Rhodnius prolixus relative to untreated animals. Citral and ruda also influenced the life cycle but not to the extent of animals exposed to cinnamon. We suggest that future research be directed toward using cinnamon in field and toxicity tests.

  16. Lower richness of small wild mammal species and chagas disease risk.

    Science.gov (United States)

    Xavier, Samanta Cristina das Chagas; Roque, André Luiz Rodrigues; Lima, Valdirene dos Santos; Monteiro, Kerla Joeline Lima; Otaviano, Joel Carlos Rodrigues; Ferreira da Silva, Luiz Felipe Coutinho; Jansen, Ana Maria

    2012-01-01

    A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649) were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11-89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance) was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM) demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test). Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease.

  17. Lower richness of small wild mammal species and chagas disease risk.

    Directory of Open Access Journals (Sweden)

    Samanta Cristina das Chagas Xavier

    Full Text Available A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649 were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11-89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test. Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease.

  18. Enfermedad de Chagas aguda, en un adulto tratado con benznidazol (Rochagan® en Costa Rica

    Directory of Open Access Journals (Sweden)

    Víctor M. Montenegro

    2004-06-01

    Full Text Available Se da a conocer un caso agudo de la enfermedad de Chagas en un adulto de 48 años con signo de Romaña, infectado al recibir un chorro de orina de una chinche (T. dimidiata, cuando trataba de destripada con un palo de café. Es el primer adulto con enfermedad de Chagas aguda tratado en Costa Rica con benznidazol. Se citan los síntomas encontrados, así como los aspectos epidemiológicos relacionados con su presentación. Se enfatizan el tratamiento y la evolución del caso. Se hace un llamado de atención a los clínicos, ya que este caso no fue diagnosticado apropiadamente desde un inicio, lo que evidencia el desconocimiento que existe de la enfermedad de Chagas como motivo de consulta.An acute case of Chagas "disease with Romañas" sign, in a 48 years old man, is described. Treatment with Benznidazol was succesfull. This is the first acute case in an adult treated with this drug in Costa Rica. Reference is made to the epidemiological aspects involved in this case and to the mechanism of infection. This person became infected when he was trying to kiU a nymph of T. dimidiata with a coffe stick and received a jet of urine directly in the right eye. The case was not diagnosed by the clinicians while the patient was at the hospital indicating the poor knowledge of practitioners about the characteristics of the disease in our country.

  19. Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers

    OpenAIRE

    Panzera, F.; Ferreiro, M. J.; Pita, S.; Calleros, L.; Perez, R.; Basmadjian, Y.; Guevara, Y.; Brenière, Simone Frédérique; Panzera, Y.

    2014-01-01

    Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known ...

  20. First century of Chagas' disease: an overview on novel approaches to nifurtimox and benzonidazole delivery systems.

    Science.gov (United States)

    Salomon, Claudio J

    2012-03-01

    Hundred years after the discovery of Chagas' disease, there is a lack of effective treatment to control this neglected disease caused by the parasite Trypanosoma cruzi. The transmission is primarily through vector-borne blood transfusion or during pregnancy, producing high mortality and morbidity among poor people in many countries of Latin America. In the last decades, the efforts have been focused mainly on the elimination of vectors. At the same time, screening of blood donors in order to avoid transfusional transmission has been improved all over the world. However, Chagas' disease is still a major public health problem, with estimates of nearly 90 million people at risk of infection and more than eight million infected in 18 endemic countries. Despite the high incidence in endemic regions and the dissemination of neglected diseases in North America and Europe, to date, there are only two drugs developed and prescribed for the treatment of Chagas' disease, nifurtimox (tablets of 120 mg) and benzonidazole (tablets of 100 mg). In this review, different approaches carried out in the last decades for developing novel pharmaceutical formulations for the delivery of nifurtimox and benznidazole are discussed.

  1. [The control of the transmission by transfusion of Chagas' disease in the Southern Cone Initiative].

    Science.gov (United States)

    Dias, J C; Schofield, C J

    1998-01-01

    The Southern Cone Initiative against Chagas' disease, was launched in 1991. The aim was to interrupt the transmission of Chagas disease by elimination of domestic populations of the major vector, Triatoma infestans, and by improved screening of blood donors. As a result of these activities, a marked reduction in the risk of transfusional transmission can now be seen throughout the programme area. In addition to specific legislation concerning the quality of transfused blood, a series of national and regional reference laboratories have been set up with the help of PAHO in order to improve the quality of pre-transfusional serodiagnosis. Results indicate a progressive reduction in the overall infection prevalence of blood donors, and show that the age-prevalence curve has shifted towards older age-groups. In this paper we analyse the changes in infection prevalence in the Southern Cone countries, drawing attention to the situation in Bolivia which has the highest indices of infection and lowest levels of coverage by the control programme. In this situation chemoprophylaxis of blood prior to transfusion may be recommended in accordance with PAHO criteria. In the medium term however, interruption of human Chagas disease transmission may be expected over most of the Southern Cone region, as long as the control activities are continued and consolidated through effective epidemiological surveillance.

  2. Positive deviance study to inform a Chagas disease control program in southern Ecuador.

    Science.gov (United States)

    Nieto-Sanchez, Claudia; Baus, Esteban G; Guerrero, Darwin; Grijalva, Mario J

    2015-05-01

    Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012). Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs). They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

  3. Polymorphisms of toll-like receptor 2 and 4 genes in Chagas disease

    Directory of Open Access Journals (Sweden)

    German Zafra

    2008-02-01

    Full Text Available The aim of this study was to test the possible implication of toll-like receptor 2 (TLR2 and TLR4 gene polymorphisms in determining the susceptibility to Chagas' disease. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 475 individuals from Colombia, 143 seropositive with chagasic cardiomyopathy, 132 seropositive asymptomatic and 200 seronegative. The TLR2 arginine to glutamine substitution at residue 753(Arg753Gln polymorphism was absent in the groups analyzed. The TLR4 Asp299Gly and Thr399Ile polymorphisms are in linkage disequilibrium and we observed a very low frequency of these polymorphisms in our study population (2.6% and 1.8% respectively. The overall TLR2 and TLR4 alleles and genotype distribution in seronegative and seropositive were not significantly different. We compared the frequencies between asymptomatic patients and those with chagasic cardiomyopathy and we did not observe any significant differences in the distribution of alleles or genotypes. In summary, this study corroborates the low frequency of TLR2 and TLR4 polymorphisms observed in other populations and suggest that these do not play an important role in Chagas' disease. The validation of these findings in independent cohorts is needed to firmly establish a role for TLR2 and TLR4 variants in Chagas' disease.

  4. Positive deviance study to inform a Chagas disease control program in southern Ecuador

    Directory of Open Access Journals (Sweden)

    Claudia Nieto-Sanchez

    2015-05-01

    Full Text Available Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012. Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs. They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

  5. Current and developing therapeutic agents in the treatment of Chagas disease

    Directory of Open Access Journals (Sweden)

    Werner Apt

    2010-09-01

    Full Text Available Werner AptUniversity of Chile, Faculty of Medicine, Santiago, ChileAbstract: Chagas disease must be treated in all its stages: acute, indeterminate, chronic, and initial and middle determinant chronic, due to the fact that DNA of the parasite can be demonstrated by PCR in chronic cases, where optical microscopy does not detect parasites. Nifurtimox (NF and benznidazole (BNZ are the drugs accepted to treat humans based upon ethical considerations and efficiency. However, both the drugs produce secondary effects in 30% of the cases, and the treatment must be given for at least 30–60 days. Other useful drugs are itraconazole and posaconazole. The latter may be the drug to treat Chagas disease in the future when all the investigations related to it are finished. At present, there is no criterion of cure for chronic cases since in the majority, the serology remains positive, although it may decrease. In acute cases, 70% cure with NF and 75% with BNZ is achieved. In congenital cases, 100% cure is obtained if the treatment is performed during the first year of life. In chronic acquired cases, 20% cure and 50% improvement of the electrocardiographic changes are obtained with itraconazole.Keywords: Chagas disease, treatment, nifurtimox, benznidazole, allopurinol, itraconazole, posaconazole

  6. Multi-epitope proteins for improved serological detection of Trypanosoma cruzi infection and Chagas Disease.

    Science.gov (United States)

    Duthie, Malcolm S; Guderian, Jeffery A; Vallur, Aarthy C; Misquith, Ayesha; Liang, Hong; Mohamath, Raodoh; Luquetti, Alejandro O; Carter, Darrick; Tavares, Suelene N B; Reed, Steven G

    2016-03-01

    We previously reported that tandem repeat (TR) proteins from Trypanosoma cruzi could serve as targets of the antibody response and be useful as diagnostic indicators. To optimize reagents for detecting T. cruzi infection we evaluated individual TR proteins and identified several that were recognized by the majority of Chagas patient's sera collected from individuals form Brazil. We then produced novel, recombinant fusion proteins to combine the reactive TR proteins into a single diagnostic product. Direct comparison of the antibody response of serum samples that were readily detected by the established fusion antigen used in commercial detection of Chagas disease, TcF, revealed strong responses to TcF43 and TcF26 proteins. While the TcF43 and TcF26 antigens enhanced detection and strength of signal, they did not compromise the specificity of detection compared to that obtained with TcF. Finally, it was apparent by testing against a panel of 84 serum samples assembled on the basis of moderate or weak reactivity against TcF (mostly signal:noise detected by many of the sera that had low TcF antibody levels. Taken together, these data indicate that TcF43 and TcF26 could be used to enhance the detection of T. cruzi infection as well as supporting a diagnosis of Chagas disease.

  7. Tomographic particle image velocimetry over a triangular prism in unidirectional flows

    Science.gov (United States)

    Sou, In Mei; Calantoni, Joseph

    2011-11-01

    Using tomographic particle image velocimetry (Tomo-PIV), the full three-dimensional-three-component (3D-3C) flow structure and turbulence characteristics over a triangular prism in a recirculating water tunnel were investigated. Here we present preliminary results from a new Tomo-PIV system for subcritical Froude number flows. Large-scale vortex shedding from the tip of the triangular prism is observed. Results of coherent structure organization analyzed by 3D vorticity calculation will be presented. Using the full 3D-3C instantaneous velocity field, turbulent kinetic energy is directly evaluated without any of the assumptions often needed for 2D PIV measurements. Details of the experimental setup including a unique device designed to perform our Tomo-PIV volume calibration will be discussed. We perform an in-depth turbulent kinetic energy budget and explore the feasibility of extending the measurement technique to other complex flows.

  8. Experimental Evaluation of Lightweight AAC Masonry Wall Prisms with Ferrocement Layers in Compression and Flexure

    KAUST Repository

    Abdel Mooty, Mohamed

    2012-05-01

    An experimental program is designed to evaluate the performance of lightweight autoclaved aerated concrete masonry wall strengthened using ferrocement layers, in a sandwich structure, under in-plane compression and out-of-plane bending. The 25 mm thick ferrocement mortar is reinforced with steel welded wire mesh of 1 mm diameters at 15 mm spacing. Different types of shear connectors are used to evaluate their effect on failure loads. The effect of different design parameters on the wall strength are considered including wall thickness, mortar strength, and type and distribution of shear connectors. A total of 20 prisms are tested in compression and 5 prisms are tested under bending. The proposed ferrocement strengthening technique is easy to apply on existing wall system and results in significant strength and stiffness enhancement of the tested wall specimens. © (2012) Trans Tech Publications.

  9.   Indirect versus direct feedback in computer-based Prism Adaptation Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Rytter, Hana Malá

    2010-01-01

      Prism Adaptation Therapy (PAT) is an intervention method in the treatment of the attention disorder neglect (Frassinetti, Angeli, Meneghello, Avanzi, & Ladavas, 2002; Rossetti, et al., 1998). The aim of this study was to investigate whether one session of PAT using a computer-attached touchscreen......-based implementation with an attached touchscreen. The session of PAT included a pre-exposure phase pointing at 30 targets without feedback; an exposure phase pointing at 90 targets with prism goggles and feedback; and a post-exposure phase pointing at 60 targets, with no goggles and no feedback.   The results...... have direct implications for future implementations of computer-based methods of treatment of visuospatial disorders and computer-assisted rehabilitation in general....

  10. Indirect versus direct feedback in computer-based Prism Adaptation Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Rytter, Hana Malá

    2010-01-01

    Prism Adaptation Therapy (PAT) is an intervention method in the treatment of the attention disorder neglect (Frassinetti, Angeli, Meneghello, Avanzi, & Ladavas, 2002; Rossetti, et al., 1998). The aim of this study was to investigate whether one session of PAT using a computer-attached touchscreen......-based implementation with an attached touchscreen. The session of PAT included a pre-exposure step pointing at 30 targets without feedback; an exposure step pointing at 90 targets with prism goggles and feedback; and a post-exposure step pointing at 60 targets, with no goggles and no feedback. The results indicate...... in the aftereffect. The findings have direct implications for future implementations of computer-based methods of treatment of visuospatial disorders and computer-assisted rehabilitation in general....

  11. Thermo-optic Imbert-Fedorov effect in a prism-waveguide coupling system with silicon-on-insulator

    Science.gov (United States)

    Tang, Tingting; Li, Chaoyang; Luo, Li; Zhang, Yanfen; Yuan, Quan

    2016-07-01

    In this paper, a prism-waveguide coupling system based on silicon-on-insulator (SOI) is revisited. We find that thermo-optic Imbert-Fedorov (TOIF) effect displays in this four-layer optical system which has not been proposed before. Furthermore, we discuss the TOIF shifts in prism/SiO2/Si/SiO2 and prism/Au/Si/SiO2 waveguides with different parameters and study the observed phenomena from physical point of view. It is shown that the maximum IF shift can achieve 140 μm in a prism/Au/Si/SiO2 waveguide which is large enough to be directly measured by the calculation results. Accordingly, TOIF shift provides a temperature control method for the enhancement and modulation of IF shift.

  12. Prevalence of Chagas disease in Latin-American migrants living in Europe: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ana Requena-Méndez

    2015-02-01

    Full Text Available Few studies have assessed the burden of Chagas disease in non-endemic countries and most of them are based on prevalence estimates from Latin American (LA countries that likely differ from the prevalence in migrants living in Europe. The aim of this study was to systematically review the existing data informing current understanding of the prevalence of Chagas disease in LA migrants living in European countries.We conducted a systematic review and meta-analysis of studies reporting prevalence of Chagas disease in European countries belonging to the European Union (EU before 2004 in accordance with the MOOSE guidelines and based on the database sources MEDLINE and Global Health. No restrictions were placed on study date, study design or language of publication. The pooled prevalence was estimated using random effect models based on DerSimonian & Laird method.We identified 18 studies conducted in five European countries. The random effect pooled prevalence was 4.2% (95%CI:2.2-6.7%; and the heterogeneity of Chagas disease prevalence among studies was high (I2 = 97%,p<0.001. Migrants from Bolivia had the highest prevalence of Chagas disease (18.1%, 95%CI:13.9-22.7%.Prevalence of Chagas in LA migrants living in Europe is high, particularly in migrants from Bolivia and Paraguay. Data are highly heterogeneous dependent upon country of origin and within studies of migrants from the same country of origin. Country-specific prevalence differs from the estimates available from LA countries. Our meta-analysis provides prevalence estimates of Chagas disease that should be used to estimate the burden of disease in European countries.

  13. Biogas production using anaerobic groundwater containing a subterranean microbial community associated with the accretionary prism

    OpenAIRE

    Baito, Kyohei; Imai, Satomi; Matsushita, Makoto; Otani, Miku; Sato, Yu; Kimura, Hiroyuki

    2014-01-01

    In a deep aquifer associated with an accretionary prism, significant methane (CH4) is produced by a subterranean microbial community. Here, we developed bioreactors for producing CH4 and hydrogen (H2) using anaerobic groundwater collected from the deep aquifer. To generate CH4, the anaerobic groundwater amended with organic substrates was incubated in the bioreactor. At first, H2 was detected and accumulated in the gas phase of the bioreactor. After the H2 decreased, rapid CH4 production was ...

  14. Growth Inhibitory Activity of a Bis-benzimidazole-Bridged Arene Ruthenium Metalla-Rectangle and Prism.

    Science.gov (United States)

    Vajpayee, Vaishali; Lee, Sun Mi; Park, Joeng Woo; Dubey, Abhishek; Kim, Hyunuk; Cook, Timothy R; Stang, Peter J; Chi, Ki-Whan

    2013-03-25

    Two new supramolecular coordination complexes (SCCs), were obtained from the self-assembly of a new bis-benzimidazole bridged Ru acceptor, 4, with dipyridyl and tripyridyl donors, respectively. As part of a growing library of anticancer-active Ru-based SCCs, metalla-prism 6 selectively showed high cytotoxicities relative to cisplatin for a series of cancer cell lines, with IC50 values as low as 8.41 μM for MCF7 cells, as determined from MTS assays.

  15. The Practice of an Optimal Pricing Strategy for Maximizing Store Profits Using PRISM

    OpenAIRE

    YADA, Katsutoshi; 矢田, 勝俊; OHNO, Kousuke

    2006-01-01

    © 2006 IEEE. Reprinted, with permission, from YADA Katsutoshi, OHNO Kousuke , The Practice of an Optimal Pricing Strategy for Maximizing Store Profits Using PRISM, 10/2006. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Kansai University'sproducts or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotion...

  16. Effect of Anti-dots on the Magnetic Susceptibility in a Superconducting Long Prism

    Science.gov (United States)

    Aguirre, C. A.; Joya, Miryam R.; Barba-Ortega, J.

    2017-02-01

    The magnetic susceptibility of a long mesoscopic superconducting square prism containing one/two (dot) anti-dots is calculated in the framework of the Ginzburg-Landau theoretical model. This magnetic susceptibility shows jumps at each of the vortex transition fields. We studied the influence of the number, size and geometry of the anti-dots on the magnetic susceptibility in a superconducting sample. We found interesting physical behavior when several kinds of materials filled into the anti-dot are considered.

  17. Prisms for pain. Can visuo-motor rehabilitation strategies alleviate chronic pain?

    Science.gov (United States)

    Torta, DM; Legrain, V; Rossetti, Y; Mouraux, A

    2017-01-01

    Background and aims Prism adaptation (PA) is a non-invasive procedure in which participants perform a visuo-motor pointing task while wearing prism goggles inducing a lateral displacement of the visual field and a mismatch between the seen and felt position of the pointing hand. PA is thought to induce a reorganization of sensorimotor coordination, and has been used successfully to rehabilitate neglect following right-hemisphere lesions. Because studies have shown that complex regional pain syndrome (CRPS) is associated with neglect-like symptoms, it was proposed that PA could be used to alleviate pain in these patients. Database A search for peer-reviewed articles on neglect-like symptoms in CRPS and on the use of prisms in CRPS was conducted using the PubMed database. Results There is still no agreement as to whether CRPS patients really present neglect symptoms and, if they do, what it is that they neglect. Furthermore, there is insufficient data to determine whether PA exerts an effect on CRPS symptoms. Finally, it remains unknown whether neglect can be observed in other types of lateralized pain, or whether PA could be useful for these patients. Conclusion By highlighting open issues, our review provides guidelines for future studies on the use of prisms in pain. The assessment of neglect in patients with CRPS as well as other types of lateralized chronic pain should be characterized using a combination of neuropsychological methods assessing the multiple aspects of neglect in a more refined manner. In addition, further studies should investigate the mechanisms through which PA may modulate pain. PMID:26095341

  18. HEATING OF BLANK IN FORM OF PRISM IN ACCORDANCE WITH TECHNOLOGICAL LIMITATIONS

    Directory of Open Access Journals (Sweden)

    V. B. Kovalevsky

    2009-01-01

    Full Text Available The paper considers a problem on optimum heating control of a blank in the form of prism under complicated conditions of heat-transfer in accordance with criteria of gas consumption minimization, decarburized layer and scaling. Numerical algorithm of the problem solution and examples are given in the paper. A new technology of the flame furnace operation has been developed in the paper. 

  19. Radiometric, geometric, and image quality assessment of ALOS AVNIR-2 and PRISM sensors

    Science.gov (United States)

    Saunier, S.; Goryl, P.; Chander, G.; Santer, R.; Bouvet, M.; Collet, B.; Mambimba, A.; Kocaman, Aksakal S.

    2010-01-01

    The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006, by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote-sensing sensors: 1) the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2); 2) the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM); and 3) the Phased-Array type L-band Synthetic Aperture Radar (PALSAR). Within the framework of ALOS Data European Node, as part of the European Space Agency (ESA), the European Space Research Institute worked alongside JAXA to provide contributions to the ALOS commissioning phase plan. This paper summarizes the strategy that was adopted by ESA to define and implement a data verification plan for missions operated by external agencies; these missions are classified by the ESA as third-party missions. The ESA was supported in the design and execution of this plan by GAEL Consultant. The verification of ALOS optical data from PRISM and AVNIR-2 sensors was initiated 4 months after satellite launch, and a team of principal investigators assembled to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric, and image quality assessment. The successful completion of the commissioning phase has led to the sensors being declared fit for operations. The consolidated measurements indicate that the radiometric calibration of the AVNIR-2 sensor is stable and agrees with the Landsat-7 Enhanced Thematic Mapper Plus and the Envisat MEdium-Resolution Imaging Spectrometer calibration. The geometrical accuracy of PRISM and AVNIR-2 products improved significantly and remains under control. The PRISM modulation transfer function is monitored for improved characterization. ?? 2006 IEEE.

  20. Prism adaptation and neck muscle vibration in healthy individuals: are two methods better than one?

    Science.gov (United States)

    Guinet, M; Michel, C

    2013-12-19

    Studies involving therapeutic combinations reveal an important benefit in the rehabilitation of neglect patients when compared to single therapies. In light of these observations our present work examines, in healthy individuals, sensorimotor and cognitive after-effects of prism adaptation and neck muscle vibration applied individually or simultaneously. We explored sensorimotor after-effects on visuo-manual open-loop pointing, visual and proprioceptive straight-ahead estimations. We assessed cognitive after-effects on the line bisection task. Fifty-four healthy participants were divided into six groups designated according to the exposure procedure used with each: 'Prism' (P) group; 'Vibration with a sensation of body rotation' (Vb) group; 'Vibration with a move illusion of the LED' (Vl) group; 'Association with a sensation of body rotation' (Ab) group; 'Association with a move illusion of the LED' (Al) group; and 'Control' (C) group. The main findings showed that prism adaptation applied alone or combined with vibration showed significant adaptation in visuo-manual open-loop pointing, visual straight-ahead and proprioceptive straight-ahead. Vibration alone produced significant after-effects on proprioceptive straight-ahead estimation in the Vl group. Furthermore all groups (except C group) showed a rightward neglect-like bias in line bisection following the training procedure. This is the first demonstration of cognitive after-effects following neck muscle vibration in healthy individuals. The simultaneous application of both methods did not produce significant greater after-effects than prism adaptation alone in both sensorimotor and cognitive tasks. These results are discussed in terms of transfer of sensorimotor plasticity to spatial cognition in healthy individuals.

  1. [Effectivity of different methods for disinfection of applanation tonometer prisms (author's transl)].

    Science.gov (United States)

    Wizemann, A

    1980-01-01

    In 13,440 bacteriological investigations the effectivity of different methods for desinfection of Goldmann tonometer prisms (merfen, pantasept, sekusept steril, UV sterilizer Sklar) is tested. Sekusept steril and UV sterilizer show the quickest and most sufficient results. They cause no damage to corneal epithelium or to plastic objects. We can recommend them for desinfection of applanation tonometer prims, Goldmann's gonioscopy and fundus contact lenses as routine methods.

  2. Structural analysis of β-prism lectin from Colocasia esculenta (L.) S chott.

    Science.gov (United States)

    Vajravijayan, S; Pletnev, S; Pletnev, V Z; Nandhagopal, N; Gunasekaran, K

    2016-10-01

    The Mannose-binding β-Prism Colocasia esculenta lectin (β-PCL) was purified from tubers using ion exchange chromatography. The purified β-PCL appeared as a single band of ∼12kDa on SDS-PAGE. β-PCL crystallizes in trigonal space group P3121 and diffracted to a resolution of 2.1Å. The structure was solved using Molecular replacement using Crocus vernus lectin (PDB: 3MEZ) as a model. From the final refined model to an R-factor of 16.5% and an Rfree of 20.4%, it has been observed that the biological unit consists of two β-Prism domains augmented through C-terminals swap over to form one of faces for each domain. Cα superposition of individual domains of β-PCL with individual domains of other related structures and superposition of whole protein structures were carried out. The higher RMS deviation for the superposition of whole structures suggest that β-prism domains assume different orientation in each structure.

  3. Stacking illumination of a confocal reflector light emitting diode automobile headlamp with an asymmetric triangular prism.

    Science.gov (United States)

    Chen, Hsi-Chao; Zhou, Jia-Hao; Zhou, Yang

    2017-02-01

    A confocal reflector lamp with an asymmetric triangular prism was designed for a stacking illumination of a light emitting diode (LED) automobile headlamp fitting ECE R112 asymmetrical regulation. The optical system includes three 1st elliptic reflectors, three 2nd parabolic reflectors, and one asymmetric triangular prism. Three elliptic and parabolic reflectors were assembled with three confocal reflector modules; two modules projected the cut-off line of a 0° angle, and the other module projected the cut-off line of a 15° angle using of an asymmetric triangular prism. The ray tracing, optical simulation, and mockup experiment results exhibited that the illumination distribution met the regulation of ECE R112 class B, and the ideal efficiency could reach 96.8% in theory. The tolerance analysis showed the efficiency remained above 98% under the error values of ±0.2  mm of the position of the LED light source, and the y direction of the up-down movement was more sensitive than the x and z directions. The measurement results of the mockup sample safety factor were all larger than 1.15 and supported the regulation of the ECE R112 Class B.

  4. Development of visualization tools and data processing for the PRISM earth system model

    Science.gov (United States)

    de Martino, G.; Prism Work Package 4a Visualization Group

    2003-04-01

    The PRISM project includes development of a set of visualization and processing tools for use by earth system scientists. A list of requirements has been formulated, based upon information provided by the PRISM community. After having conducted a review of the requirements and of the software packages available, the team is ready to begin development of two visualization systems: a web-enabled system designed for monitoring and quality controlling model runs as they are running (Low-End graphics), and another system for high quality analysis of data which includes the ability to do 3-D plots, animations etc. with the option of controlling plot generation through scripts or using graphical interfaces (High-End graphics). Both Low-End and High-End graphics tools will use netCDF-CF metadata, the chosen PRISM System standard type of data. This poster is intended to be a showcase for our current ideas and early plans. We wish to invite comments from the wide community of earth system modellers about what functionalities would be most useful.

  5. Research on refractive index of optical cement used in Glan-Thompson prisms

    Institute of Scientific and Technical Information of China (English)

    Haifeng Wang; Fuquan Wu; Hailong Wang; Jing Wang; Shan Zhang

    2007-01-01

    The influence of the refractive index n2 of optical cement on the structure angle, field angle, and transmission of Glan-Thompson prism has been studied in detail. The results show that the structure angle will increase with the decrease of n2 under the condition of the largest field angle. Thus, the ratio of length to width (L/A) of the prism will decrease, which means more materials can be saved. When the value of L/A is 3.0 or 2.5 in the routine design, the field angle will firstly increase and then decrease with the increment of n2. Two routine designs with the n2 values of 1.47 and 1.45 have the optimal field angle. In addition, n2 also has great influence on light intensity transmittance of the prism. Considering all these factors, it will be the best choice with L/A=2.5 and n2 = 1.45 - 1.46.

  6. A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators

    Directory of Open Access Journals (Sweden)

    Ngoc Hai Vu

    2016-08-01

    Full Text Available We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC. In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC, and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™. Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity of the P-CPC structure, a lower-cost mass production process is possible. A simulation based on optimal structure of P-CPC was performed and the results also shown that P-CPC has high angular tolerance for input sunlight. The high tolerance of the input angle of sunlight allows P-CPC solar concentrator utilize a single sun tracking system instead of a highly precise dual suntracking system as cost effective solution.

  7. Compact multi-projection 3D display using a wedge prism

    Science.gov (United States)

    Park, Soon-gi; Lee, Chang-Kun; Lee, Byoungho

    2015-03-01

    We propose a compact multi-projection system based on integral floating method with waveguide projection. Waveguide projection can reduce the projection distance by multiple folding of optical path inside the waveguide. The proposed system is composed of a wedge prism, which is used as a waveguide, multiple projection-units, and an anisotropic screen made of floating lens combined with a vertical diffuser. As the projected image propagates through the wedge prism, it is reflected at the surfaces of prism by total internal reflections, and the final view image is created by the floating lens at the viewpoints. The position of view point is decided by the lens equation, and the interval of view point is calculated by the magnification of collimating lens and interval of projection-units. We believe that the proposed method can be useful for implementing a large-scale autostereoscopic 3D system with high quality of 3D images using projection optics. In addition, the reduced volume of the system will alleviate the restriction of installment condition, and will widen the applications of a multi-projection 3D display.

  8. Experimental Investigation on Soft Galloping and Hard Galloping of Triangular Prisms

    Directory of Open Access Journals (Sweden)

    Jijian Lian

    2017-02-01

    Full Text Available The studies currently on soft galloping (SG and hard galloping (HG are scarce. In this study, SG and HG of spring-mounted triangular prisms in a water channel are investigated experimentally. A power take-off system (PTO, a spring system, additional weights, and different triangular prisms were used to achieve the variations in damping coefficient c, system stiffness K, oscillation mass m and section aspect ratios α, respectively. The present paper proves that the VIV (vortex-induced vibration lower branch can be observed in the SG response. In SG response, VIV branches are incomplete while the galloping branch is complete, and galloping can be self-initiated only in the self-excited region. On the contrary, in HG response, VIV branches are complete, the galloping branch is incomplete, and galloping can only be initiated by external excitation at a velocity exceeding the critical velocity. As c and m increase, or K and α decrease, the oscillation mode of a triangular prism gradually transitions from SG to CG (critical galloping, and continues to HG. The amplitude in VIV branch is the main reason causing the onset of galloping in SG response. A critical damping coefficient cc, which is dependent on m, K and α, is proposed to predict the occurrences of SG, CG and HG. When c < cc, SG occurs; when c > cc, HG occurs; when c = cc, CG occurs.

  9. Melatonin in Chagas´ disease: Possible therapeutic value La melatonina en la enfermedad de Chagas: Su posible valor terapéutico

    Directory of Open Access Journals (Sweden)

    Daniel P. Cardinali

    2011-10-01

    Full Text Available Chagas' disease is a severe health problem in Latin America, causing approximately 50 000 deaths a year, with approximately 18 million infected people. About 25-30% of the patients infected with Trypanosoma cruzi develop the chronic form of the disease. The protective response against T. cruzi depends on both innate and acquired immunity involving macrophages, natural killer cells, T and B lymphocytes, and the production of proinflammatory Th-1 cytokines. In addition, an increased nitric oxide (NO production in macrophages leading to effective microbicidal action is needed to control parasitemia. Melatonin is detectable in T. cruzi and may play a role in promoting infection whereas, when administered in high doses during the acute phase of T. cruzi infection, it can decrease parasitemia while reducing NO production. During chronic disease progression, the sustained oxidative stress concomitant to myocardial damage could be reduced by administering melatonin. It is hypothesized that the coordinated administration of a melatonin agonist like the MT1/MT2 agonist ramelteon, that lacks antioxidant activity and may not affect NO production during the acute phase, and of melatonin in doses high enough to decrease oxidative damage, to preserve mitochondrial and to prevent cardiomyopathy during the chronic phase, could be a novel add-on treatment of Chagas´ disease.La enfermedad de Chagas es un problema grave de salud en América Latina, causando cerca de 50 000 muertes al año y unos 18 millones de infectados. Alrededor del 25-30% de los pacientes infectados con Trypanosoma cruzi desarrollan la forma crónica de la enfermedad. La respuesta de defensa ante el T. cruzi depende de la inmunidad innata y adquirida con la participación de macrófagos, células “natural killer”, linfocitos T y B, y la producción de citoquinas proinflamatorias de tipo Th-1. Además, el aumento en la producción de óxido nítrico (NO en los macrófagos lleva a una acci

  10. Enfermedad de Chagas en poblaciones prehistóricas del norte de Chile Chagas disease in prehistoric populations of northern Chile

    Directory of Open Access Journals (Sweden)

    NANCY ORELLANA-HALKYER

    2010-12-01

    Full Text Available La enfermedad de Chagas es producida por el parásito Trypanosoma cruzi, el cual afecta tanto a seres humanos como a animales, en particular mamíferos marsupiales y placentarios. Las vías de transmisión son diversas, siendo una de las más importantes la vía vectorial, en la que participan insectos infectados con este parásito, animales y humanos. En este artículo de revisión discutimos los postulados sobre la vía de transmisión oral, los hallazgos de T. cruzi en momias de América y especialmente en las del norte de Chile. Presentamos además información que apunta a que la enfermedad de Chagas estuvo presente mucho antes de la conquista europea y de la construcción de viviendas de adobe. Comentamos las hipótesis sobre el vector domiciliado más importante de Sudamérica, Triatoma infestans, su antigüedad en la costa de Arica y los reportes más recientes de otros vectores silvestres. También se discute la información relacionada a la participación en el ciclo de T. cruzi de distintos mamíferos silvestres de Chile y asimismo proponemos el estudio paleoparasitológico en restos zooarqueológicos para conocer las especies de mamíferos reservónos de T. cruzi en la antigüedad.Chagas diseases is produced by a parasite named Trypanosoma cruzi, that affects humans and other marsupial and placental mammals. Transmission routes are diverse, but the most important transmission is the vector route, which involves the triatomine insects, wild and domestic infected animáis, and humans. Here we review the data about oral transmission route and the evidences of the etiological agent (Trypanosoma cruzi of Chagas disease in pre-Columbian American mummies, making a critical review of the infection in northern Chile. Moreover, we comment on the hypotheses suggested in relation to the most important vector of the infection in South América Triatoma infestans, its antiquity in the Arica coast, and the recent reports about other wild infected

  11. ONE-DIMENSIONAL LIGHT BEAM WIDENING USING PRISMS FOR INCREASE OF SPECTROMETER SPECTRAL RESOLUTION AND ANGULAR DISPERSION

    Directory of Open Access Journals (Sweden)

    I. M. Gulis

    2016-01-01

    Full Text Available The increase of angular dispersion and slit resolution limit of grating spectrometers by means of variation of grating parameters is limited by its period and allowable order of diffraction. The special solutions (echelle, holographic, immersion gratings are acceptable in a limited parameter range and are technologically complex in fabrication, thus hardly applicable to instruments of mass production. We propose to decrease slit resolution limit by one-dimensional beam widening in dispersion plane by means of passing it through oblique prism before incidence onto diffraction grating. The increase of angular dispersion can be achieved by narrowing of dispersed beams after grating while passing through other oblique prism. We prove that slit resolution limit in such a system changes approximately as multiplied by angular magnification of the first prism (that is less than 1 times. Also angular dispersion changed approximately as multiplied by angular magnification of the second prism. The Fresnel reflection from the faces of prisms is analyzed. Accounting for that factor gives the increase of resolution about 1,4–1,6 times without loss of light (and can be 2 and more times while using anti-reflective coating. The proposed method is different from the similar ones first of all by its simplicity because it uses simple optical elements – plane reflective grating and thin prisms. It can be applied to amend the analytical characteristics of dispersive spectrometers, first of all the small-sized ones. 

  12. A single blinded randomised controlled pilot trial of prism adaptation for improving self-care in stroke patients with neglect.

    Science.gov (United States)

    Turton, Ailie J; O'Leary, Kelly; Gabb, Judith; Woodward, Rebecca; Gilchrist, Iain D

    2010-04-01

    Prism adaptation has been shown to alleviate the symptoms of unilateral spatial neglect following stroke in single case and small group studies. The purposes of this single blinded pilot randomised controlled trial were to determine the feasibility of delivering prism adaptation treatment in a clinically valid sample and to assess its impact on self-care. Thirty seven right hemisphere stroke patients with unilateral spatial neglect were randomised into either prism adaptation (using 10 dioptre, 6 degree prisms) or sham treatment (using plain glasses) groups. Treatment was delivered each weekday for two weeks. Pointing accuracy, without vision of the finger, was recorded each day before treatment. Outcome was measured, by blinded assessors, four days and eight weeks after the end of treatment using the Catherine Bergego Scale (CBS) and the conventional neuropsychological tests from the Behavioural Inattention Test (BIT). Thirty four patients received treatment: 16 with prisms, 18 sham. Mean compliance was 99% and 97%, respectively. Over the treatment days only the prism treated group showed increased leftward bias in open loop pointing to targets on a touch screen. However, despite the group level changes in pointing behaviour no overall effect of the treatment on self-care or BIT were found.

  13. Chagas disease: what is known and what is needed - A background article

    Directory of Open Access Journals (Sweden)

    José Rodrigues Coura

    2007-10-01

    Full Text Available Chagas disease began millions of years ago as an enzootic disease of wild animals and started to be transmitted to man accidentally in the form of an anthropozoonosis when man invaded wild ecotopes. Endemic Chagas disease became established as a zoonosis over the last 200-300 years through forest clearance for agriculture and livestock rearing and adaptation of triatomines to domestic environments and to man and domestic animals as a food source. It is estimated that 15 to 16 million people are infected with Trypanosoma cruzi in Latin America and 75 to 90 million people are exposed to infection. When T. cruzi is transmitted to man through the feces of triatomines, at bite sites or in mucosa, through blood transfusion or orally through contaminated food, it invades the bloodstream and lymphatic system and becomes established in the muscle and cardiac tissue, the digestive system and phagocytic cells. This causes inflammatory lesions and immune responses, particularly mediated by CD4+, CD8+, interleukin-2 (IL and IL-4, with cell and neuron destruction and fibrosis, and leads to blockage of the cardiac conduction system, arrhythmia, cardiac insufficiency, aperistalsis, and dilatation of hollow viscera, particularly the esophagus and colon. T. cruzi may also be transmitted from mother to child across the placenta and through the birth canal, thus causing abortion, prematurity, and organic lesions in the fetus. In immunosuppressed individuals, T. cruzi infection may become reactivated such that it spreads as a severe disease causing diffuse myocarditis and lesions of the central nervous system. Chagas disease is characterized by an acute phase with or without symptoms, and with entry point signs (inoculation chagoma or Romaña's sign, fever, adenomegaly, hepatosplenomegaly, and evident parasitemia, and an indeterminate chronic phase (asymptomatic, with normal results from electrocardiogram and x-ray of the heart, esophagus, and colon or with a

  14. PERANCANGAN DAN IMPLEMENTASI SISTEM PENGUKURAN KINERJA DENGAN METODE PERFORMANCE PRISM (Studi Kasus pada Hotel X

    Directory of Open Access Journals (Sweden)

    Iwan Vanany

    2004-01-01

    Full Text Available This article described a result of research design of performance measurement system in hotel business with Performance Prism Model. As long as, performance measurement system at hotel X not yet representatived organization performance according to comprehensif and integrated. Because of needed redesign performance measurement system with new model. From the objective condition of hotel X, Performance Prism model more representative than others. The result of design described that stakeholder in hotel X such as: customer, employee, supplier, owner and investor, and regulator and community. From the performance measurement system design are obtained 36 types Key Performance Indicator (KPI such as: 6 KPI of customer, 9 KPI of staff manajerial, 9 KPI of staff operational, 4 KPI of supplier, 3 KPI of investor, and 5 KPI of regulator & community. Result of implementation performance measurement system with scoring system indicates that the amount of scor current performance indicator is 50,75%. Result of measurement can be based management act evaluation and choice planning improvement organization and all Stakeholder requirements must be request. Abstract in Bahasa Indonesia : Artikel ini menguraikan hasil penelitian perancangan sistem pengukuran kinerja pada sebuah perusahaan dalam bisnis hotel dengan model Performance Prism. Selama ini, sistem pengukuran kinerja di Hotel X belum merepresentasikan kinerja organisasi secara komprehensif dan integratif. Oleh karena itu, perlu dilakukan perancangan kembali sistem pengukuran kinerjanya. Dari kondisi objektif hotel X, model yang tepat digunakan adalah model Performance Prism dibanding model lain. Hasil rancangan menunjukkan bahwa stakeholder hotel X meliputi: konsumen, tenaga kerja, supplier, pemilik/investor, serta pemerintah dan masyarakat sekitar lingkungan hotel. Sistem pengukuran kinerja memuat 36 KPI yang meliputi 6 KPI konsumen, 9 KPI staff manajerial, 9 KPI staff operasional, 4 KPI supplier, 3

  15. Results from SCS Profiling of the Sumatra accretionary prism: insights into tsnamigenesis

    Science.gov (United States)

    Fisher, D.; Mosher, D.; Austin, J.; Gulick, S.; Moran, K.; Masterlark, T.

    2007-12-01

    The SEATOS high resolution single-channel seismic reflection survey of the Sumatran accretionary prism depicts a landward-vergent thrust front, with active folding characterizing part of the December 2004 Mw9.2 earthquake rupture zone. Structure and bathymetry co-vary at distinct wavelengths along a 220-km-long profile crossing the prism and the Aceh (forearc) Basin. At the largest wavelength (tens of kms), the prism surface is defined by a steep (8-12 degrees), 55-km-wide outer slope, a 110-km-wide upper slope forming a broad depression between two forearc highs, and a 25 km-wide, steep inner slope between the landward high and the forearc basin. Anticlinal ridges spaced ~13 km apart display landward- and seaward-vergent folds along the inner and outer slopes, respectively; symmetric folding occurs across the upper slope. We suggest that the long-wavelength variations are consistent with the existence of a strong inner wedge beneath the upper slope. The ~13 km anticline spacing implies deformation of a slope apron deforming independently of this stronger wedge interior. Seismic profiles crossing the toe of the prism image a series of landward vergent, fault-related folds, suggesting that the shallow fill of the Sunda Trench is delaminated from the predominantly seaward-vergent plate boundary system and is uptilted along a triangle zone. Profiles crossing the seaward flank of the Aceh Basin reveal a near- vertical, undulatory deformation front that appears to mark the location of the West Andaman-Mentawai right- lateral strike-slip fault zone. Our model for prism architecture based on these geophysical results involves advance of the strong inner wedge during great earthquakes like the 2004 event, which then peels up shallower and less competent trench fill, deforming the toe and the upper slope of the forearc, producing massive uplift that is likely tsunamigenic. Seismic rupture was limited to the megathrust westward of the West Andaman fault and ROV observations

  16. GPS Velocities and Structure Across the Burma Accretionary Prism and Shillong Plateau in Bangladesh

    Science.gov (United States)

    Akhter, S. H.; Steckler, M. S.; Seeber, L.; Agostinetti, N. P.; Kogan, M. G.

    2010-12-01

    We have installed a suite of 18 GPS receiver across the Bengal Basin, covering the country of Bangladesh, near the junction of the Indian Shield, the Himayalan collision belt and the Burma Arc subduction zone. The crust of the Indian Shield thins eastward across the hinge zone of an Early Cretaceous continental margin. The thin continental and/or oceanic crust of the eastern Bengal Basin beyond the hinge zone is overlain by a thick sedimentary sequence of 16 km or more. This heavily-sedimented basin is being overridden from the north by the Shillong Massif, a 2-km high plateau exposing Indian Shield, and from the east by the accretionary prism of the Burma Arc subduction system. The soft collision of the Burma Arc with the Bengal Basin and Ganges-Brahmaputra Delta (GBD) has built a large accretionary prism that widens northwards to 250-300 km. The prism reaches as much as half way across the deep Bengal Basin and the thrust front is blind and buried by the rapid sedimentation of the GBD. Our GPS data cover the frontal region of this unusual subaerial accretionary prism. The convergence across this belt is oblique and partitioned. Our GPS array in Bangladesh shows similar velocity gradients across the accretionary prism corresponding to both E-W shortening and N-S dextral shear. The rates are consistent with the data further east in India. How this motion is partitioned into elastic earthquake-cycle loading and permanent inelastic deformation is unclear. The north-dipping Dauki thrust fault is responsible for the uplifted Shillong Plateau overriding the low-lying and rapidly subsiding Surma Basin. This crustal scale convergent boundary could represent the beginning of a forward jump of the Himalayan front. The surface expression of this boundary is a regional south-verging anticline folding Quaternary sediment into its forelimb at the deformation front south of the Plateau. This suggests that the Dauki Fault, too, is blind and extends well south of the topographic

  17. Clinical forms of Trypanosoma cruzi infected individuals in the chronic phase of Chagas disease in Puebla, Mexico

    Directory of Open Access Journals (Sweden)

    María del Carmen Sánchez-Guillén

    2006-11-01

    Full Text Available In Mexico, despite the relatively high seroprevalence of Trypanosoma cruzi infection in humans in some areas, reported morbidity of Chagas disease is not clear. We determined clinical stage in 71 individuals seropositive to T. cruzi in the state of Puebla, Mexico, an area endemic for Chagas disease with a reported seroprevalence of 7.7%. Diagnosis of Chagas disease was made by two standardized serological tests (ELISA, IHA. Individuals were stratified according to clinical studies. All patients were submitted to EKG, barium swallow, and barium enema. Groups were identified as indeterminate form (IF asymptomatic individuals without evidence of abnormalities (n = 34 cases; those with gastrointestinal alterations (12 patients including symptoms of abnormal relaxation of the lower esophageal sphincter and absent peristalsis in the esophageal body, grade I megaesophagus, and/or megacolon; patients with clinical manifestations and documented changes of chronic Chagas heart disease who were subdivided as follows: mild (8 patients - mild electrocardiographic changes of ventricular repolarization, sinus bradychardia; moderate (6 patients - left bundle branch block, right bundle branch block associated with left anterior fascicular block; severe (8 patients - signs of cardiomegaly, dilated cardiomyopathy; and the associated form (3 cases that included presence of both cardiomyopathy and megaesophagus. These data highlight the importance of accurate evaluation of the prevalence and clinical course of Chagas disease in endemic and non-endemic areas of Mexico.

  18. [The assessment process within science and the nomination of Carlos Chagas for the Nobel prize for Physiology or Medicine].

    Science.gov (United States)

    Pittella, José Eymard Homem

    2009-01-01

    One of the greatest achievements in the history of medicine was the description of Chagas disease by the physician and scientist Carlos Chagas. A hundred years after the discovery of the disease, speculation still remains regarding the two official nominations of Carlos Chagas for the Nobel Prize, the biggest worldwide scientific award, in 1913 and in 1921. It has been accepted that the reason why the prize was not awarded to this brilliant scientist may have been the strong opposition that he faced in Brazil, from some physicians and researchers of that time. They went as far as questioning the existence of Chagas disease, thereby possibly influencing the decision of the Nobel Committee not to award the prize to him. Analysis of the database of the Nobel prize archives, with the revelation of the names of nominators, nominees and prizewinners spanning the years 1901-1951, brought information not only about what was considered to be a scientific achievement at that time, but also about who the important scientists were and what the relationships between them were. The non-recognition of Carlos Chagas' discoveries by the Nobel Committee appears to be more correctly explained by these factors than by the negative impact of the local opposition.

  19. Clinical forms of Trypanosoma cruzi infected individuals in the chronic phase of Chagas disease in Puebla, Mexico.

    Science.gov (United States)

    Sánchez-Guillén, María Del Carmen; López-Colombo, Aurelio; Ordóñez-Toquero, Guillermo; Gomez-Albino, Isidoro; Ramos-Jimenez, Judith; Torres-Rasgado, Enrique; Salgado-Rosas, Hilda; Romero-Díaz, Mónica; Pulido-Pérez, Patricia; Pérez-Fuentes, Ricardo

    2006-11-01

    In Mexico, despite the relatively high seroprevalence of Trypanosoma cruzi infection in humans in some areas, reported morbidity of Chagas disease is not clear. We determined clinical stage in 71 individuals seropositive to T. cruzi in the state of Puebla, Mexico, an area endemic for Chagas disease with a reported seroprevalence of 7.7%. Diagnosis of Chagas disease was made by two standardized serological tests (ELISA, IHA). Individuals were stratified according to clinical studies. All patients were submitted to EKG, barium swallow, and barium enema. Groups were identified as indeterminate form (IF) asymptomatic individuals without evidence of abnormalities (n = 34 cases); those with gastrointestinal alterations (12 patients) including symptoms of abnormal relaxation of the lower esophageal sphincter and absent peristalsis in the esophageal body, grade I megaesophagus, and/or megacolon; patients with clinical manifestations and documented changes of chronic Chagas heart disease who were subdivided as follows: mild (8 patients)--mild electrocardiographic changes of ventricular repolarization, sinus bradychardia); moderate (6 patients)--left bundle branch block, right bundle branch block associated with left anterior fascicular block); severe (8 patients)--signs of cardiomegaly, dilated cardiomyopathy); and the associated form (3 cases) that included presence of both cardiomyopathy and megaesophagus. These data highlight the importance of accurate evaluation of the prevalence and clinical course of Chagas disease in endemic and non-endemic areas of Mexico.

  20. Seroprevalence and sociocultural conditionants of Chagas disease in school aged children of marginal zones of Asunción

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    Vera Ninfa I.

    1998-01-01

    Full Text Available Chagas disease is becoming a public health problem in Latin America due to the wide distribution, the high prevalence, the magnitude of the damage caused and the difficulties to control it. In Paraguay, the disease is mainly distributed in the departments of Paraguari, Cordillera and Central. Prevalence in marginal zones, where migrations from rural populations and endemic areas make possible the urbanization of the disease, has no been studied yet. This is a descriptive study with a cross-sectional sampling and a probabilistic system recruitment carried out in school aged children from marginal zones of Asuncion to determine the prevalence of Chagas' disease. Serological methods, parasite isolation and questionnaires were used to achieve the goals. Nine hundred and fifty three children were studied to determine the prevalence of Chagas' disease in marginal zones which was 1.4%.

  1. Evaluation of the Chagas Disease Control Program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil

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    Adriana dos Santos

    2014-04-01

    Full Text Available Introduction Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005 interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP in Açucena and to offer suggestions for improving local epidemiological surveillance. Methods This study was conducted in three phases: I a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF and indirect hemaglutination (IHA on venous blood for borderline cases and those in the gray zone of reactivity; II vector evaluation using the data obtained by local health agents during 2006-2010; and III examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Results Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67% index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Conclusions Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

  2. Impact of Helminth Infection on the Clinical and Microbiological Presentation of Chagas Diseases in Chronically Infected Patients.

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    Fernando Salvador

    2016-04-01

    Full Text Available Helminth infections are highly prevalent in tropical and subtropical countries, coexisting in Chagas disease endemic areas. Helminth infections in humans may modulate the host immune system, changing the Th1/Th2 polarization. This immunological disturbance could modify the immune response to other infections. The aim of this study is to evaluate the relationship between clinical, microbiological and epidemiological characteristics of Chagas disease patients, with the presence of helminth infection.A prospective observational study was conducted at Vall d'Hebron University Hospital (Barcelona, Spain. Inclusion criteria were: age over 18 years, diagnosis of Chagas disease, and not having received specific treatment for Chagas disease previously to the inclusion. The study protocol included Chagas disease assessment (cardiac and digestive evaluation, detection of T. cruzi DNA measured by PCR in peripheral blood, and helminth infection diagnosis (detection of IgG anti-Strongyloides stercoralis by ELISA, microscopic examination of stool samples from three different days, and specific faecal culture for S. stercoralis larvae.Overall, 65 patients were included, median age was 38 years, 75.4% were women and most of them came from Bolivia. Cardiac and digestive involvement was present in 18.5% and 27.7% of patients respectively. T. cruzi PCR was positive in 28 (43.1% patients. Helminth infection was diagnosed in 12 (18.5% patients. No differences were observed in clinical and epidemiological characteristics between patients with and without helminth infection. Nevertheless, the proportion of patients with positive T. cruzi PCR was higher among patients with helminth infection compared with patients without helminth infection (75% vs 35.8%, p = 0.021.We observed a high prevalence of S. stercoralis infection among chronic Chagas disease patients attended in our tropical medicine unit. Strongyloidiasis was associated with significantly higher proportion of

  3. Protective human leucocyte antigen haplotype, HLA-DRB1*01-B*14, against chronic Chagas disease in Bolivia.

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    Florencia del Puerto

    Full Text Available BACKGROUND: Chagas disease, caused by the flagellate parasite Trypanosoma cruzi affects 8-10 million people in Latin America. The mechanisms that underlie the development of complications of chronic Chagas disease, characterized primarily by pathology of the heart and digestive system, are not currently understood. To identify possible host genetic factors that may influence the clinical course of Chagas disease, Human Leucocyte Antigen (HLA regional gene polymorphism was analyzed in patients presenting with differing clinical symptoms. METHODOLOGY: Two hundred and twenty nine chronic Chagas disease patients in Santa Cruz, Bolivia, were examined by serological tests, electrocardiogram (ECG, and Barium enema colon X-ray. 31.4% of the examinees showed ECG alterations, 15.7% megacolon and 58.1% showed neither of them. A further 62 seropositive megacolon patients who had undergone colonectomy due to acute abdomen were recruited. We analyzed their HLA genetic polymorphisms (HLA-A, HLA-B, MICA, MICB, DRB1 and TNF-alpha promoter region mainly through Sequence based and LABType SSO typing test using LUMINEX Technology. PRINCIPAL FINDINGS: The frequencies of HLA-DRB1*01 and HLA-B*14:02 were significantly lower in patients suffering from megacolon as well as in those with ECG alteration and/or megacolon compared with a group of patients with indeterminate symptoms. The DRB1*0102, B*1402 and MICA*011 alleles were in strong Linkage Disequilibrium (LD, and the HLA-DRB1*01-B*14-MICA*011 haplotype was associated with resistance against chronic Chagas disease. CONCLUSIONS: This is the first report of HLA haplotype association with resistance to chronic Chagas disease.

  4. Serological survey for Chagas' disease in school children in the Rio de Janeiro State, Brazil

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    Walter B. Petana

    1976-04-01

    Full Text Available A serological survey for Chagas' disease was carried out in school children in the Rio de Janeiro State, a zone considered as non-endemic for the infection. A total of 168 schools in 20 municipalities have been visited and 13,254 blood samples were obtained. The blood eluates were screened by the indirect fluorescence test (IFT, and all positive samples were checked and confirmed in sera by the complement fixation test (CFT. AH serologically positive children were subject to a clinical scrutiny, and the houses where the children lived have been searched for triatomine bugs. Only in two municipalities, Magé and Araruama, there was a significant number of children found positive. The total number of reactive samples by IFT and CFT from 13,004 blood samples screened was 143 (1.00 per cent. No serious clinicai symptoms suggestive of Chagas' disease have been found in any of the positive children, and no triatomine bugs were discovered in the dwellings where the children lived. The overall small percentage of children with positive serology postulates that the infection is not a serious health problem in the area investigated. It is recommended, however, to carry out a more detailed study in Magé and Araruama to find the reason for the relatively high percentage of serologically positive children encountered in these two municipalities.Um inquérito sorológico pela reação de imunofluorescência indireta para doença de Chagas, foi realizado, incluindo 13.254 crianças de 168 escolas primárias sorteadas em 20 municípios do Estado do Rio de Janeiro. Os casos positivos pela imunofluorescência eram confirmados pela reação de fixação do complemento e submetidos a exame clínico, investigando-se em seguida suas residências quanto à existência ou não de triatomíneos. Somente nos municípios de Magé e Araruama houve um número significativo de crianças com sorologia positiva. Do total de amostras estudadas somente 143 (1% foram positivas

  5. Moléstia de Chagas aguda experimental: parasitismo do hipotálamo Experimental acute Chagas disease in the rat: parasitism of hypothalamus

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    Edymar Jardim

    1971-06-01

    Full Text Available O autor procurou relações entre alterações funcionais atribuídas ao hipotálamo e lesões orgânicas do mesmo, na vigência da moléstia de Chagas. Usou em seu trabalho ratos inoculados com T. cruzi por via intraperitonial. Realizou estudo histopatológico e quantitativo neuronal das várias regiões hipotalâmicas, em cortes seriados corados com a hematoxilina-eosina. Encontrou considerável percentagem de parasitismo hipotalâmico (70%, sendo que a região anterior é mais parasitada que a média ou a posterior. A destruição neuronal foi também mais evidente na região anterior. Sugere que as alterações do metabolismo glicídico, tireoidiano, da sudação e da potassemia, devam ser consideradas como seqüelas destas lesões.This work search relations between functional impairments imputed to hypothalamus and organic lesions in Chagas' disease. The author used rats with T. cruzi inoculation by intraperitonial way. Histopathologic and quantitative neuronal studies were done by serial sections of hypothalamus. It was demonstrated that the anterior hypothalamic region is more parasited than others, with greater neuronal destruction also. The author suggests that impairments of glycidic and thyroidian metabolism, of sweating and potassium blood level, must be considered as sequels of these lesions.

  6. When a Diplomat goes into politics because of war. The case of João Chagas (1910-1914

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    Luís Alves de Fraga

    2012-01-01

    Full Text Available Analysis of the case of a Portuguese diplomat, João Chagas, who, during the First Republic, and by resorting to the conditions available to him as representative of his country, surpassed the mere negotiating role attributed to diplomacy to conduct national politics, succeeding in changing the international statute of Portugal in the Great War. The article describes the internal and external situation of Portugal in political, geopolitical and geostrategic terms, the conflict between Portuguese and British interests, the activity of Portuguese diplomats in London, Berlin and Paris, and, finally, the work of João Chagas.

  7. Current epidemiological trends for Chagas disease in Latin America and future challenges in epidemiology, surveillance and health policy

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    Álvaro Moncayo

    2009-07-01

    Full Text Available Chagas disease, named after Carlos Chagas, who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine bugs and via blood transfusion. Chagas disease has two successive phases: acute and chronic. The acute phase lasts six-eight weeks. Several years after entering the chronic phase, 20-35% of infected individuals, depending on the geographical area, will develop irreversible lesions of the autonomous nervous system in the heart, oesophagus and colon, and of the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980s as a result of the demographically representative cross-sectional studies in countries where accurate information was not previously available. A group of experts met in Brasilia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country programme in the Southern Cone countries, the transmission of Chagas disease by vectors and via blood transfusion was interrupted in Uruguay in 1997, in Chile in 1999 and in Brazil in 2006; thus, the incidence of new infections by T. cruzi across the South American continent has decreased by 70%. Similar multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been reported towards the goal of interrupting the transmission of Chagas disease, as requested by a 1998 Resolution of the World Health Assembly. The cost-benefit analysis of investment in the vector control programme in Brazil indicates that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the programme is a health investment with very high return. Many well-known research institutions in Latin America were key elements of a

  8. Behaviour of concrete beams reinforced withFRP prestressed concrete prisms

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    Svecova, Dagmar

    The use of fibre reinforced plastics (FRP) to reinforce concrete is gaining acceptance. However, due to the relatively low modulus of FRP, in comparison to steel, such structures may, if sufficient amount of reinforcement is not used, suffer from large deformations and wide cracks. FRP is generally more suited for prestressing. Since it is not feasible to prestress all concrete structures to eliminate the large deflections of FRP reinforced concrete flexural members, researchers are focusing on other strategies. A simple method for avoiding excessive deflections is to provide sufficiently high amount of FRP reinforcement to limit its stress (strain) to acceptable levels under service loads. This approach will not be able to take advantage of the high strength of FRP and will be generally uneconomical. The current investigation focuses on the feasibility of an alternative strategy. This thesis deals with the flexural and shear behaviour of concrete beams reinforced with FRP prestressed concrete prisms. FRP prestressed concrete prisms (PCP) are new reinforcing bars, made by pretensioning FRP and embedding it in high strength grout/concrete. The purpose of the research is to investigate the feasibility of using such pretensioned rebars, and their effect on the flexural and shear behaviour of reinforced concrete beams over the entire loading range. Due to the prestress in the prisms, deflection of concrete beams reinforced with this product is substantially reduced, and is comparable to similarly steel reinforced beams. The thesis comprises both theoretical and experimental investigations. In the experimental part, nine beams reinforced with FRP prestressed concrete prisms, and two companion beams, one steel and one FRP reinforced were tested. All the beams were designed to carry the same ultimate moment. Excellent flexural and shear behaviour of beams reinforced with higher prestressed prisms is reported. When comparing deflections of three beams designed to have the

  9. Arctic PRISM Shorebird Location and Plot Survey Geodatabase. U.S. Fish and Wildlife Service, Division of Migratory Bird Management (2012).

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    Arctic Landscape Conservation Cooperative — This dataset consists of shorebird surveys conducted as part of the Program for Regional and International Shorebird Monitoring (PRISM). This dataset was derived...

  10. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology.

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    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies the significance of PriSM in biology and medicine. This perspective aims to highlight some recent advances of the research on PriSM. This paper starts with description of the intriguing similarities between PriSM and prions, discusses the paradoxical features of PriSM, introduces the methods for elucidating the biological functions of PriSM, illustrates several examples of beneficial aspects of PriSM, and finishes with the promises and current challenges in the research of PriSM. We anticipate that the research of PriSM will contribute to the fundamental understanding at the intersection of supramolecular chemistry and cell biology and ultimately lead to a new paradigm of molecular (or supramolecular) therapeutics for biomedicine.

  11. Estudo radiológico do megacólon em área endêmica de doença de Chagas Radiological study on megacolon cases in an endemic area for Chagas disease

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    Cleudson Castro

    2010-10-01

    Full Text Available INTRODUÇÃO: Foi realizado estudo radiológico do cólon em pacientes de zona endêmica da doença de Chagas usando-se a técnica do enema opaco simplificado de Ximenes e cols. MÉTODOS: Participaram 291 pacientes, com idade media de 48,8 (±12,5 anos, sendo 222 soropositivos para doença de Chagas. Fizeram radiografias na posição ântero-posterior, póstero-anterior e perfil lateral esquerdo, que foram analisadas por inspeção visual e medida do maior diâmetro em centímetros do reto e sigmoide. RESULTADOS: À inspeção visual, foi possível diagnosticar megacólon em 14 (6,3% pacientes chagásicos. A média do diâmetro da ampola retal dos chagásicos 6,3 (±1,0cm foi semelhante a dos não-chagásicos 6,2 (±1,0cm (p=0,391 e o diâmetro médio da alça sigmoide dos chagásicos 5 (±1,6cm foi maior que o dos não chagásicos 4,4 (±0,8 cm, (p=0,001. CONCLUSÕES: Excluindo-se os casos de megacólon evidente e de provável megacólon, a população chagásica continuou com o diâmetro médio do sigmoide significantemente maior (p=0,003 que a não chagásica.INTRODUCTION: A radiological study on the colon of patients from an endemic Chagas disease zone was conducted using the simplified opaque enema technique of Ximenes et al. METHODS: The study involved 291 individuals with a mean age of 48.8(±12.5 years-old, of whom 222 were seropositive for Chagas disease. Anteroposterior, posteroanterior and left lateral view radiographs were analyzed by visual inspection and measurement of the largest rectal and sigmoid diameters. RESULTS: From the visual inspection, megacolon was diagnosed in 14 (6.3% Chagas disease patients. The mean diameter of the rectal ampulla among the Chagas patients was 6.3 (±1.0cm, similar to the measurement in non-Chagas individuals: 6.2 (±1.0 cm (p= 0.391. The mean sigmoid loop diameter in the Chagas patients was 5 (±1.6cm, which was larger than among the non-Chagas individuals: 4.4 (±0.8cm (p= 0.001. CONCLUSIONS

  12. Cultivation-Independent Methods Reveal Differences among Bacterial Gut Microbiota in Triatomine Vectors of Chagas Disease

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    da Mota, Fabio Faria; Marinho, Lourena Pinheiro; Moreira, Carlos José de Carvalho; Lima, Marli Maria; Mello, Cícero Brasileiro; Garcia, Eloi Souza; Carels, Nicolas; Azambuja, Patricia

    2012-01-01

    Background Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. Methodology/Principal Findings Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE) and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. Conclusions/Significance The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low complexity whose structure

  13. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

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    Tassi, Eduardo Marinho, E-mail: etassi@ibest.com.br [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Continentino, Marcelo Abramoff [Hospital Frei Galvão, Guaratinguetá, SP (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia - UFRJ, Rio de Janeiro, RJ (Brazil); Pedrosa, Roberto Coury [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2014-05-15

    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups.

  14. Design or screening of drugs for the treatment of Chagas disease: what shows the most promise?

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    Lepesheva, Galina I.

    2013-01-01

    Introduction Endemic in Latin America, Chagas disease is now becoming a serious global health problem, and yet has no financial viability for the pharmaceutical industry and remains incurable. In 2012, two antimycotic drugs inhibitors of fungal sterol 14α-demethylase (CYP51) – posaconazole and ravuconazole – entered clinical trials. Availability of the X-ray structure of the orthologous enzyme from the causative agent of the disease, protozoan parasite Trypanosoma cruzi, determined in complexes with posaconazole as well as with several experimental protozoa-specific CYP51 inhibitors opens an excellent opportunity to improve the situation. Areas covered This article summarizes the information available in PubMed and Google on the outcomes of treatment of the chronic Chagas disease. It also outlines the major features of the T. cruzi CYP51 structure and the possible structure-based strategies for rational design of novel T. cruzi specific drugs. Expert opinion There is no doubt that screenings for alternative drug-like molecules as well as mining the T. cruzi genome for novel drug targets are of great value and might eventually lead to groundbreaking discoveries. However, all newly identified molecules must proceed through the long, expensive and low-yielding drug optimization process, and all novel potential drug targets must be validated in terms of their essentiality and druggability. CYP51 is already a well-validated and highly successful target for clinical and agricultural antifungals. With minimal investments into the final stages of their development/trials, T. cruzi-specific CYP51 inhibitors can provide an immediate treatment for Chagas disease, either on their own or in combination with the currently available drugs. PMID:24079515

  15. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas.

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    Péneau, Julie; Nguyen, Anne; Flores-Ferrer, Alheli; Blanchet, Denis; Gourbière, Sébastien

    2016-02-01

    The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.

  16. Suicide risk and alcohol and drug abuse in outpatients with HIV infection and Chagas disease

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    Patrícia M. Guimarães

    2014-05-01

    Full Text Available Objective: To evaluate psychiatric comorbidities in outpatients receiving care for HIV and Chagas disease at Instituto de Pesquisa Clínica Evandro Chagas (IPEC, Fundação Oswaldo Cruz (Fiocruz, Rio de Janeiro, Brazil. Methods: Cross-sectional study with a consecutive sample of 125 patients referred to an outpatient psychiatric clinic from February to December 2010. The Mini International Neuropsychiatric Interview (MINI was used. Factors associated with more frequent mental disorders were estimated by odds ratios (OR with 95% confidence intervals (95%CI by multiple logistic regression. Results: Seventy-six (60.8% patients with HIV, 40 (32% patients with Chagas disease, and nine (7.2% patients with human T-lymphotropic virus were interviewed. The majority were women (64%, with up to 8 years of formal education (56%, and unemployed (81.6%. The median age was 49 years. Suicide risk (n=71 (56%, agoraphobia (n=65 (52%, major depressive episode (n=56 (44.8%, and alcohol/drug abuse (n=43 (34.4% predominated, the latter being directly associated with lower family income (OR = 2.64; 95%CI 1.03-6.75 and HIV infection (OR = 5.24; 95%CI 1.56-17.61. Suicide risk was associated with non-white skin color (OR = 2.21; 95%CI 1.03-4.75, unemployment (OR = 2.72; 95%CI 1.01-7.34, and diagnosis of major depression (OR = 3.34; 95%CI 1.54-7.44. Conclusion: Measures targeting adverse socioeconomic conditions and psychiatric and psychological monitoring and care should be encouraged in this population, considering the association with abuse of alcohol/other psychoactive drugs and suicide risk.

  17. Pharmacophore modeling for anti-Chagas drug design using the fragment molecular orbital method.

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    Ryunosuke Yoshino

    Full Text Available Chagas disease, caused by the parasite Trypanosoma cruzi, is a neglected tropical disease that causes severe human health problems. To develop a new chemotherapeutic agent for the treatment of Chagas disease, we predicted a pharmacophore model for T. cruzi dihydroorotate dehydrogenase (TcDHODH by fragment molecular orbital (FMO calculation for orotate, oxonate, and 43 orotate derivatives.Intermolecular interactions in the complexes of TcDHODH with orotate, oxonate, and 43 orotate derivatives were analyzed by FMO calculation at the MP2/6-31G level. The results indicated that the orotate moiety, which is the base fragment of these compounds, interacts with the Lys43, Asn67, and Asn194 residues of TcDHODH and the cofactor flavin mononucleotide (FMN, whereas functional groups introduced at the orotate 5-position strongly interact with the Lys214 residue.FMO-based interaction energy analyses revealed a pharmacophore model for TcDHODH inhibitor. Hydrogen bond acceptor pharmacophores correspond to Lys43 and Lys214, hydrogen bond donor and acceptor pharmacophores correspond to Asn67 and Asn194, and the aromatic ring pharmacophore corresponds to FMN, which shows important characteristics of compounds that inhibit TcDHODH. In addition, the Lys214 residue is not conserved between TcDHODH and human DHODH. Our analysis suggests that these orotate derivatives should preferentially bind to TcDHODH, increasing their selectivity. Our results obtained by pharmacophore modeling provides insight into the structural requirements for the design of TcDHODH inhibitors and their development as new anti-Chagas drugs.

  18. Stairway to Heaven or Hell? Perspectives and Limitations of Chagas Disease Chemotherapy.

    Science.gov (United States)

    Salomao, Kelly; Menna-Barreto, Rubem Figueiredo Sadok; de Castro, Solange Lisboa

    2016-01-01

    In this review, we intend to provide a general view of the evolution of experimental studies in the area of chemotherapy for Chagas disease. We can follow the process of drug development through three phases. The first phase began almost at the same time as the discovery made by Carlos Chagas and proceeds to 1970, during which time an extensive list of compounds was subjected to preclinical and clinical trials. The second phase began with the introduction of nifurtimox and benznidazole into the clinical setting, followed with the search for alternative drugs. In this phase, a dichotomy existed between rational and empirical approaches in preclinical studies. The third phase began with the unravelling of the T. cruzi genome. The development of transgenic parasites has allowed the development of solid HTS protocols, and the establishment of bioluminescent T. cruzi has allowed in vivo drug evaluations using a reduced number of animals. Among the wide variety of compounds subjected to preclinical studies, we have discovered azolic and non-azolic inhibitors of sterol C14α-demethylase (CYP51) and nitro compounds. Two compounds evaluated during the second phase, namely, MK-436 and allopurinol, could be revisited. Clinical studies of posaconazole and E1224 yielded disappointing results, and it is critical to understand the reason for their failure as a monotherapy. Currently, the combination and repositioning of drugs with different mechanisms of action are complementary approaches. The use of drug combinations, particularly those of nitro compounds with CYP51 inhibitors, is considered a real alternative for the treatment of Chagas disease.

  19. Cultivation-independent methods reveal differences among bacterial gut microbiota in triatomine vectors of Chagas disease.

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    Fabio Faria da Mota

    Full Text Available BACKGROUND: Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. METHODOLOGY/PRINCIPAL FINDINGS: Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. CONCLUSIONS/SIGNIFICANCE: The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low

  20. Chagas disease: morbidity profile in an endemic area of Northeastern Brazil

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    Cléber de Mesquita Andrade

    2015-12-01

    Full Text Available Abstract: INTRODUCTION : This study evaluated the clinical forms and manifestation severities of Chagas disease among serologically reactive individuals from Western Rio Grande do Norte (Northeastern Brazil. METHODS : This cross-sectional study included 186 adults who were evaluated using electrocardiography, echocardiography, chest radiography, and contrast radiography of the esophagus and colon. A clinical-epidemiological questionnaire was also used. RESULTS : The indeterminate, cardiac, digestive, and cardiodigestive clinical forms of Chagas disease were diagnosed in 51.6% (96/186, 32.2% (60/186, 8.1% (15/186 and 8.1% (15/186 of the participants, respectively. Heart failure (functional classes I-IV was detected in 7.5% (14/186 of the participants, and 36.4% (24/66, 30.3% (20/66, 15.2% (10/66, 13.6% (9/66, and 4.5% (3/66 of the patients were at stage A, B1, B2, C, and D, respectively. Dilated cardiomyopathy and electrocardiographic changes were detected in 10.2% (19/186 and 48.1% (91/186 of the participants, respectively. Apical aneurysm was diagnosed in 10.8% (20/186 of the participants, and other changes in the segmental myocardial contractility of the left ventricle were diagnosed in 33.9% (63/186 of the participants. Megaesophagus (groups I-IV was observed in 7% (13/186 of the participants, megacolon (grades 1-3 was detected in12.9% (24/186 of the participants, and both organs were affected in 29.2% (7/24 of the megacolon cases. CONCLUSIONS : We detected various clinical forms of Chagas disease (including the digestive form. Our findings indicate that clinical symptoms alone may not be sufficient to exclude or confirm cardiac and/or digestive damage, and the number of patients with symptomatic clinical forms may be underestimated.

  1. Antitrypanosomal Treatment with Benznidazole Is Superior to Posaconazole Regimens in Mouse Models of Chagas Disease.

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    Khare, Shilpi; Liu, Xianzhong; Stinson, Monique; Rivera, Ianne; Groessl, Todd; Tuntland, Tove; Yeh, Vince; Wen, Ben; Molteni, Valentina; Glynne, Richard; Supek, Frantisek

    2015-10-01

    Two CYP51 inhibitors, posaconazole and the ravuconazole prodrug E1224, were recently tested in clinical trials for efficacy in indeterminate Chagas disease. The results from these studies show that both drugs cleared parasites from the blood of infected patients at the end of the treatment but that parasitemia rebounded over the following months. In the current study, we sought to identify a dosing regimen of posaconazole that could permanently clear Trypanosoma cruzi from mice with experimental Chagas disease. Infected mice were treated with posaconazole or benznidazole, an established Chagas disease drug, and parasitological cure was defined as an absence of parasitemia recrudescence after immunosuppression. Twenty-day therapy with benznidazole (10 to 100 mg/kg of body weight/day) resulted in a dose-dependent increase in antiparasitic activity, and the 100-mg/kg regimen effected parasitological cure in all treated mice. In contrast, all mice remained infected after a 25-day treatment with posaconazole at all tested doses (10 to 100 mg/kg/day). Further extension of posaconazole therapy to 40 days resulted in only a marginal improvement of treatment outcome. We also observed similar differences in antiparasitic activity between benznidazole and posaconazole in acute T. cruzi heart infections. While benznidazole induced rapid, dose-dependent reductions in heart parasite burdens, the antiparasitic activity of posaconazole plateaued at low doses (3 to 10 mg/kg/day) despite increasing drug exposure in plasma. These observations are in good agreement with the outcomes of recent phase 2 trials with posaconazole and suggest that the efficacy models combined with the pharmacokinetic analysis employed here will be useful in predicting clinical outcomes of new drug candidates.

  2. Utilizing Chemical Genomics to Identify Cytochrome b as a Novel Drug Target for Chagas Disease.

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    Shilpi Khare

    2015-07-01

    Full Text Available Unbiased phenotypic screens enable identification of small molecules that inhibit pathogen growth by unanticipated mechanisms. These small molecules can be used as starting points for drug discovery programs that target such mechanisms. A major challenge of the approach is the identification of the cellular targets. Here we report GNF7686, a small molecule inhibitor of Trypanosoma cruzi, the causative agent of Chagas disease, and identification of cytochrome b as its target. Following discovery of GNF7686 in a parasite growth inhibition high throughput screen, we were able to evolve a GNF7686-resistant culture of T. cruzi epimastigotes. Clones from this culture bore a mutation coding for a substitution of leucine by phenylalanine at amino acid position 197 in cytochrome b. Cytochrome b is a component of complex III (cytochrome bc1 in the mitochondrial electron transport chain and catalyzes the transfer of electrons from ubiquinol to cytochrome c by a mechanism that utilizes two distinct catalytic sites, QN and QP. The L197F mutation is located in the QN site and confers resistance to GNF7686 in both parasite cell growth and biochemical cytochrome b assays. Additionally, the mutant cytochrome b confers resistance to antimycin A, another QN site inhibitor, but not to strobilurin or myxothiazol, which target the QP site. GNF7686 represents a promising starting point for Chagas disease drug discovery as it potently inhibits growth of intracellular T. cruzi amastigotes with a half maximal effective concentration (EC50 of 0.15 µM, and is highly specific for T. cruzi cytochrome b. No effect on the mammalian respiratory chain or mammalian cell proliferation was observed with up to 25 µM of GNF7686. Our approach, which combines T. cruzi chemical genetics with biochemical target validation, can be broadly applied to the discovery of additional novel drug targets and drug leads for Chagas disease.

  3. Dynamics of dual prism adaptation: relating novel experimental results to a minimalistic neural model.

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    Orlando Arévalo

    Full Text Available In everyday life, humans interact with a dynamic environment often requiring rapid adaptation of visual perception and motor control. In particular, new visuo-motor mappings must be learned while old skills have to be kept, such that after adaptation, subjects may be able to quickly change between two different modes of generating movements ('dual-adaptation'. A fundamental question is how the adaptation schedule determines the acquisition speed of new skills. Given a fixed number of movements in two different environments, will dual-adaptation be faster if switches ('phase changes' between the environments occur more frequently? We investigated the dynamics of dual-adaptation under different training schedules in a virtual pointing experiment. Surprisingly, we found that acquisition speed of dual visuo-motor mappings in a pointing task is largely independent of the number of phase changes. Next, we studied the neuronal mechanisms underlying this result and other key phenomena of dual-adaptation by relating model simulations to experimental data. We propose a simple and yet biologically plausible neural model consisting of a spatial mapping from an input layer to a pointing angle which is subjected to a global gain modulation. Adaptation is performed by reinforcement learning on the model parameters. Despite its simplicity, the model provides a unifying account for a broad range of experimental data: It quantitatively reproduced the learning rates in dual-adaptation experiments for both direct effect, i.e. adaptation to prisms, and aftereffect, i.e. behavior after removal of prisms, and their independence on the number of phase changes. Several other phenomena, e.g. initial pointing errors that are far smaller than the induced optical shift, were also captured. Moreover, the underlying mechanisms, a local adaptation of a spatial mapping and a global adaptation of a gain factor, explained asymmetric spatial transfer and generalization of prism

  4. Using brain potentials to understand prism adaptation: the error-related negativity and the P300

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    Stephane Joseph Maclean

    2015-06-01

    Full Text Available Prism adaptation (PA is both a perceptual-motor learning task as well as a promising rehabilitation tool for visuo-spatial neglect (VSN – a spatial attention disorder often experienced after stroke resulting in slowed and/or inaccurate motor responses to contralesional targets. During PA, individuals are exposed to prism-induced shifts of the visual-field while performing a visuo-guided reaching task. After adaptation, with goggles removed, visuo-motor responding is shifted to the opposite direction of that initially induced by the prisms. This visuo-motor aftereffect has been used to study visuo-motor learning and adaptation and has been applied clinically to reduce VSN severity by improving motor responding to stimuli in contralesional (usually left-sided space. In order to optimize PA’s use for VSN patients, it is important to elucidate the neural and cognitive processes that alter visuomotor function during PA. In the present study, healthy young adults underwent PA while event-related potentials (ERPs were recorded at the termination of each reach (screen-touch, then binned according to accuracy (hit vs. miss and phase of exposure block (early, middle, late. Results show that two ERP components were evoked by screen-touch: an early error-related negativity (ERN, and a P300. The ERN was consistently evoked on miss trials during adaptation, while the P300 amplitude was largest during the early phase of adaptation for both hit and miss trials. This study provides evidence of two neural signals sensitive to visual feedback during PA that may sub-serve changes in visuomotor responding. Prior ERP research suggests that the ERN reflects an error processing system in medial-frontal cortex, while the P300 is suggested to reflect a system for context updating and learning. Future research is needed to elucidate the role of these ERP components in improving visuomotor responses among individuals with VSN.

  5. Post-cracking behavior of blocks, prisms, and small concrete walls reinforced with plant fiber

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    I. I. Soto

    Full Text Available Structural masonry using concrete blocks promotes the rationalization of construction projects, lowering the final cost of a building through the elimination of forms and the reduction of the consumption of reinforcement bars. Moreover, production of a block containing a combination of concrete and vegetable fiber sisal results in a unit with properties such as mechanical strength, stiffness, flexibility, ability to absorb energy, and post-cracking behavior that are comparable to those of a block produced with plain concrete. Herein are reported the results of a study on the post-cracking behavior of blocks, prisms, and small walls reinforced with sisal fibers (lengths of 20 mm and 40 mm added at volume fractions of 0.5% and 1%. Tests were performed to characterize the fibers and blocks and to determine the compressive strength of the units, prisms, and small walls. The deformation modulus of the elements was calculated and the stress-strain curves were plotted to gain a better understanding of the values obtained. The compression test results for the small walls reinforced with fibers were similar to those of the reference walls and better than the blocks and prisms with added fibers, which had resistances lower than those of the corresponding conventional materials. All elements prepared with the addition of sisal exhibited an increase in the deformation capacity (conferred by the fibers, which was observed in the stress-strain curves. The failure mode of the reference elements was characterized by an abrupt fracture, whereas the reinforced elements underwent ductile breakage. This result was because of the presence of the fibers, which remained attached to the faces of the cracks via adhesion to the cement matrix, thus preventing loss of continuity in the material. Therefore, the cement/plant fiber composites are advantageous in terms of their ductility and ability to resist further damage after cracking.

  6. Machining characteristics of complex prism pattern on electroplated roll by copper

    Institute of Scientific and Technical Information of China (English)

    Tae-Jin JE; Sang-Cheon PARK; Kang-Won LEE; Yeong-Eun YOO; Doo-Sun CHOI; Kyung-Hyun WHANG; Myung-Chang KANG

    2009-01-01

    The BLU (back light unit)is the core component of the LCD for notebook, mobile-phone, navigation, as well as large sized TV, PID (public information display), etc. In order to enhance optical efficiency of LCD, optical films with the uniform prism patterns have been used for BLU by stacking two films up orthogonally. In this case, light interference-phenomenon occurred such as Morie, wet-out, u-turning, etc. It caused several problems such as low brightness, spots and stripes in LCD. Recently, the high-luminance micro complex prism patterns are actively studied to avoid the light interference-phenomenon and enhance the optical efficiency. In this study, the roll master to manufacture complex micro prism pattern film was machined by using the high precision lathe. The machined patterns on the roll master were 50, 45, 40, 35, 30, 25, 20, 15, 10 and 5μm in the pitch with 25.0, 22.5, 20.0, 17.5, 15.0, 12.5, 10.0, 7.5, 5.0 and 2.5 μm in the peak height, respectively. The roll was 2 000 mm in length and 320 mm in diameter. The electroplated roll by copper and the natural single crystal diamond tool was used for machining the patterns. The cutting force was measured and analyzed for each cutting condition by using the dynamometer. The chips and the surfaces after being machined were analyzed by SEM and microscope.

  7. Bisecting real and fake body parts: effects of prism adaptation after right brain damage.

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    Bolognini, Nadia; Casanova, Debora; Maravita, Angelo; Vallar, Giuseppe

    2012-01-01

    The representation of body parts holds a special status in the brain, due to their prototypical shape and the contribution of multisensory (visual and somatosensory-proprioceptive) information. In a previous study (Sposito et al., 2010), we showed that patients with left unilateral spatial neglect exhibit a rightward bias in setting the midpoint of their left forearm, which becomes larger when bisecting a cylindrical object comparable in size. This body part advantage, found also in control participants, suggests partly different processes for computing the extent of body parts and objects. In this study we tested 16 right-brain-damaged patients, and 10 unimpaired participants, on a manual bisection task of their own (real) left forearm, or a size-matched fake forearm. We then explored the effects of adaptation to rightward displacing prism exposure, which brings about leftward aftereffects. We found that all participants showed prism adaptation (PA) and aftereffects, with right-brain-damaged patients exhibiting a reduction of the rightward bias for both real and fake forearm, with no overall differences between them. Second, correlation analyses highlighted the role of visual and proprioceptive information for the metrics of body parts. Third, single-patient analyses showed dissociations between real and fake forearm bisections, and the effects of PA, as well as a more frequent impairment with fake body parts. In sum, the rightward bias shown by right-brain-damaged patients in bisecting body parts is reduced by prism exposure, as other components of the neglect syndrome; discrete spatial representations for real and fake body parts, for which visual and proprioceptive codes play different roles, are likely to exist. Multisensory information seems to render self bodily segments more resistant to the disruption brought about by right-hemisphere injury.

  8. Epidemiología de la enfermedad de Chagas en el estado de Veracruz

    OpenAIRE

    Grupo de Estudio sobre la Enfermedad de Chagas; Segura,Elsa L; Alejandro Escobar-Mesa

    2005-01-01

    Objetivo. Identificar la seroprevalencia de enfermedad de Chagas, los factores de riesgo de la vivienda e índices entomológicos, para proponer medidas de control en 11 jurisdicciones sanitarias del estado de Veracruz. Material y métodos. Entre 1997 y 2001 se hizo un estudio transversal cuya muestra quedó integrada por 281 localidades, 2 526 viviendas y 9 782 individuos. Se aplicó un cuestionario sobre factores de riesgo, se tomó sangre en papel filtro y se buscaron triatominos en el intra y p...

  9. PREVALENCE OF CHAGAS DISEASE IN A RURAL AREA IN THE STATE OF CEARA, BRAZIL

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    FREITAS, Erlane Chaves; OLIVEIRA, Maria de Fátima; ANDRADE, Mônica Coelho; VASCONCELOS, Arduina Sofia Ortet de Barros; da SILVA, José Damião; CÂNDIDO, Darlan da Silva; PEREIRA, Laíse dos Santos; CORREIA, João Paulo Ramalho; da CRUZ, José Napoleão Monte; CAVALCANTI, Luciano Pamplona de Góes

    2015-01-01

    SUMMARY Chagas disease is caused by Trypanosoma cruzi and affects about two to three million people in Brazil, still figuring as an important public health problem. A study was conducted in a rural area of the municipality of Limoeiro do Norte - CE, northeastern Brazil, aiming to determine the prevalence of T. cruzi infection. Of the inhabitants, 52% were examined, among whom 2.6% (4/154) were seropositive in at least two serological tests. All seropositive individuals were older than 50 years, farmers, with a low education and a family income of less than three minimum wages. Active surveillance may be an alternative for early detection of this disease. PMID:26603232

  10. Soro-epidemiologia da doença de Chagas em Santa Catarina

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    BR Schlemper Jr

    1983-12-01

    Full Text Available Em Santa Catarina, o Inquérito Sorológico Nacional para doença de Chagas (CNPq-SUCAM revelou positividade de 1,3% em cerca de 74.000 amostras de soro processadas pela reação de imunofluorescência indireta em papel de filtro, com 15 municípios apresentando prevalências de 5,4% a 41,3%. Na presente investigação, em 9 dos municípios com alta prevalência, foram obtidas amostras de sangue, por punção venosa, de 222 indivíduos dos quais 140 haviam sido sorologicamente positivos e 58 negativos no Inquérito Nacional. Em 24 outros indivíduos a reação foi executada pela primeira vez. Os testes sorológicos (imunofluorescência indireta, hemaglutinação indireta, aglutinação direta com e sem 2-mercaptoetanol e fixação do complemento realizados em 3 diferentes laboratórios evidenciaram 220 soros negativos e apenas 2 positivos. Dados epidenúológicos obtidos nas áreas trabalhadas confirmaram estes resultados negativos. Os resultados discordam daqueles encontrados pelo Inquérito Sorológico Nacional e confirmam a inexistência de focos domiciliares de transmissão da doença de Chagas em Santa Catarina.The National Serologic Survey (CNPq - SUCAM for Chagfis'disease in Santa Catarina revealed 1,3% of positive results in 74.000 serum samples. The method employed was indirect immunofluorescence in filter paper. Fifteen cities have shown high prevalence (5,4% to 41,3%. In the present investigation the blood samples were obtained in 9 cities by venous punction of 222 persons: 140 from people serologicaly positive, 58 negative in the National Survey as well as 24 other persons in which the reaction was performed for the first time The serologic test (indirect immunofluorescence, indirect hemagglutination, direct agghxtination with and without 2-ME and complement fíxation carried out in three diferent laboratories detected 220 negative and only 2 positive sera. This result was confirmed by specific epidemiological aspects related to

  11. ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

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    Hasslocher-Moreno Alejandro M

    2010-11-01

    Full Text Available Abstract Background Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance. Methods A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease. Results Heterogeneity was high within each test (ELISA and PCR and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied. Conclusions Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in

  12. Triatominae species of Suriname (Heteroptera: Reduviidae and their role as vectors of Chagas disease

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    Hélène Hiwat

    2014-07-01

    Full Text Available Nine species of Triatominae, representing three tribes and five genera, are currently known in Suriname. An annotated list of the species based on the collections of the Bureau of Public Health (Suriname, the National Zoological Collection Suriname and the National History Museum Leiden (the Netherlands is provided. Additionally, the results of several years of opportunistic collection in two domestic environments are presented. The most common species are Rhodnius pictipes Stål, 1972, Rhodnius robustus Larrouse, 1972 and Panstrongylus geniculatus (Latreille, 1811. The significance of the species as vectors of Chagas disease in Suriname is discussed.

  13. A inserção institucional do controle da doença de Chagas

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    Antônio Carlos Silveira

    2011-01-01

    Full Text Available Em 1943, a partir da criação do "Centro de Estudos e Profilaxia da Moléstia de Chagas" da Fundação Oswaldo Cruz de Bambuí em Minas Gerais, são concebidas as bases tecnológicas e metodológicas para o controle extensivo da enfermidade. Para isso foi decisivo o advento de um novo inseticida (o gammexane, P 530 e a demonstração de sua eficácia no controle dos vetores da doença de Chagas. Como resultado prático desses acontecimentos em "maio de 1950 foi oficialmente inaugurada, em Uberaba, a primeira campanha de profilaxia da doença de Chagas, no Brasil". Mesmo que se dispusesse desde então de meios para fazer o controle da transmissão vetorial da endemia chagásica, não se dispunha dos recursos financeiros exigidos para fazê-lo de forma abrangente e regular. O baixo nível de prioridade conferida a essa atividade se expressava em sua inserção institucional. Em 1941, foram criados os Serviços Nacionais, de malária, peste, varíola, entre outros, enquanto a doença de Chagas fazia parte da Divisão de Organização Sanitária (DOS, que reunia enfermidades consideradas de menor importância. Em 1956 o Departamento Nacional de Endemias Rurais (DNERu incorporou todas as chamadas grandes endemias em uma única instituição, mas na prática isso não significou a implementação das ações de controle da doença de Chagas. Com a reestruturação do Ministério da Saúde em 1970, a Superintendência de Campanhas de Saúde Pública (SUCAM abarcou todas as endemias rurais, e a doença de Chagas passou a ter o status de Divisão Nacional, na mesma posição hierárquica daquelas outras doenças transmitidas por vetores antes consideradas prioritárias. Essa condição determinou a possibilidade de uma repartição de recursos mais equilibrada, o que efetivamente ocorreu, com a realocação de pessoal e insumos do programa de malária para o controle vetorial da doença de Chagas. Em 1991, a Fundação Nacional de Saúde sucedeu a SUCAM

  14. Training the Next Generation of Scientists: System Dynamics Modeling of Chagas Disease (American Trypanosomiasis) transmission.

    Science.gov (United States)

    Goff, P.; Hulse, A.; Harder, H. R.; Pierce, L. A.; Rizzo, D.; Hanley, J.; Orantes, L.; Stevens, L.; Justi, S.; Monroy, C.

    2015-12-01

    A computational simulation has been designed as an investigative case study by high school students to introduce system dynamics modeling into high school curriculum. This case study approach leads users through the forensics necessary to diagnose an unknown disease in a Central American village. This disease, Chagas, is endemic to 21 Latin American countries. The CDC estimates that of the 110 million people living in areas with the disease, 8 million are infected, with as many as 300,000 US cases. Chagas is caused by the protozoan parasite, Trypanosoma cruzi, and is spread via blood feeding insect (vectors), that feed on vertebrates and live in crevasses in the walls and roofs of adobe homes. One-third of the infected people will develop chronic Chagas who are asymptomatic for years before their heart or GI tract become enlarged resulting in death. The case study has three parts. Students play the role of WHO field investigators and work collaboratively to: 1) use genetics to identify the host(s) and vector of the disease 2) use a STELLA™ SIR (Susceptible, Infected, Recovered) system dynamics model to study Chagas at the village scale and 3) develop management strategies. The simulations identify mitigation strategies known as Ecohealth Interventions (e.g., home improvements using local materials) to help stakeholders test and compare multiple optima. High school students collaborated with researchers from the University of Vermont, Loyola University and Universidad de San Carlos, Guatemala, working in labs, interviewing researchers, and incorporating mulitple field data as part of a NSF-funded multiyear grant. The model displays stable equilibria of hosts, vectors, and disease-states. Sensitivity analyses show measures of household condition and presence of vertebrates were significant leverage points, supporting other findings by the University research team. The village-scale model explores multiple solutions to disease mitigation for the purpose of producing

  15. Triatominae species of Suriname (Heteroptera: Reduviidae) and their role as vectors of Chagas disease.

    Science.gov (United States)

    Hiwat, Hélène

    2014-07-01

    Nine species of Triatominae, representing three tribes and five genera, are currently known in Suriname. An annotated list of the species based on the collections of the Bureau of Public Health (Suriname), the National Zoological Collection Suriname and the National History Museum Leiden (the Netherlands) is provided. Additionally, the results of several years of opportunistic collection in two domestic environments are presented. The most common species are Rhodnius pictipes Stål, 1972, Rhodnius robustus Larrouse, 1972 and Panstrongylus geniculatus (Latreille, 1811). The significance of the species as vectors of Chagas disease in Suriname is discussed.

  16. Distantiae transmission of Trypanosoma cruzi: a new epidemiological feature of acute Chagas disease in Brazil.

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    Samanta Cristina das Chagas Xavier

    2014-05-01

    Full Text Available BACKGROUND: The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD cases associated with the consumption of açaí juice. METHODOLOGY/PRINCIPAL FINDINGS: The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Val-de Cães that report the majority of the autochthonous cases of ACD in Belém city. Moreover, we evaluated the enzootic cycle on the three islands that provide most of the açaí fruit that is consumed in these localities. We employed parasitological and serological tests throughout to evaluate infectivity competence and exposure to T. cruzi. In Val-de-Cães, no wild mammal presented positive parasitological tests, and 56% seroprevalence was observed, with low serological titers. Three of 14 triatomines were found to be infected (TcI. This unexpected epidemiological picture does not explain the high number of autochthonous ACD cases. In Jurunas, the cases of ACD could not be autochthonous because of the absence of any enzootic cycle of T. cruzi. In contrast, in the 3 island areas from which the açaí fruit originates, 66.7% of wild mammals and two dogs displayed positive hemocultures, and 15.6% of triatomines were found to be infected by T. cruzi. Genotyping by mini-exon gene and PCR-RFLP (1f8/Akw21I targeting revealed that the mammals and triatomines from the islands harbored TcI and Trypanosoma rangeli in single and mixed infections. CONCLUSION/SIGNIFICANCE: These findings show that cases of Chagas disease in the urban area of Belém may be derived from infected triatomines coming together with the açaí fruits from distant islands. We term this new epidemiological feature of Chagas disease as "Distantiae transmission".

  17. Prevalence of Chagas disease in Brazil: a systematic review and meta-analysis.

    Science.gov (United States)

    Martins-Melo, Francisco Rogerlândio; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Heukelbach, Jorg

    2014-02-01

    Chagas disease is a major public health problem in Brazil and Latin America. During the last years, it has become an emerging problem in North America and Europe due to increasing international migration. Here we describe the prevalence of Chagas disease in Brazil through a systematic review. We searched national and international electronic databases, grey literature and reference lists of selected articles for population-based studies on Chagas disease prevalence in Brazil, performed from 1980 until September 2012. Forty-two articles with relevant prevalence data were identified from a total of 4985 references. Prevalence ranged from 0% to 25.1%. Most surveys were performed in the Northeast region, especially in the state of Piauí. We observed a high degree of heterogeneity in most pooled estimates (I(2)>75%; pdisease prevalence across studies for the entire period was 4.2% (95% CI: 3.1-5.7), ranging from 4.4% (95% CI: 2.3-8.3) in the 1980s to 2.4% (95% CI: 1.5-3.8) after 2000. Females (4.2%; 95% CI: 2.6-6.8), >60 year-olds (17.7%; 95% CI: 11.4-26.5), Northeast (5.0%; 95% CI: 3.1-8.1) and Southeast (5.0%; CI: 2.4-9.9) regions and mixed (urban/rural) areas (6.4%; 95% CI: 4.2-9.4) had the highest pooled prevalence. About 4.6 million (95% CI: 2.9-7.2 million) of people are estimated to be infected with Trypanosoma cruzi. The small number of studies and small-scale samples of the general population in some areas limit interpretation, and findings of this review do not necessarily reflect the situation of the entire country. Systematic population-based studies at regional and national level are recommended to provide more accurate estimates and better define the epidemiology and risk areas of Chagas disease in Brazil.

  18. Training Systems Modelers through the Development of a Multi-scale Chagas Disease Risk Model

    Science.gov (United States)

    Hanley, J.; Stevens-Goodnight, S.; Kulkarni, S.; Bustamante, D.; Fytilis, N.; Goff, P.; Monroy, C.; Morrissey, L. A.; Orantes, L.; Stevens, L.; Dorn, P.; Lucero, D.; Rios, J.; Rizzo, D. M.

    2012-12-01

    The goal of our NSF-sponsored Division of Behavioral and Cognitive Sciences grant is to create a multidisciplinary approach to develop spatially explicit models of vector-borne disease risk using Chagas disease as our model. Chagas disease is a parasitic disease endemic to Latin America that afflicts an estimated 10 million people. The causative agent (Trypanosoma cruzi) is most commonly transmitted to humans by blood feeding triatomine insect vectors. Our objectives are: (1) advance knowledge on the multiple interacting factors affecting the transmission of Chagas disease, and (2) provide next generation genomic and spatial analysis tools applicable to the study of other vector-borne diseases worldwide. This funding is a collaborative effort between the RSENR (UVM), the School of Engineering (UVM), the Department of Biology (UVM), the Department of Biological Sciences (Loyola (New Orleans)) and the Laboratory of Applied Entomology and Parasitology (Universidad de San Carlos). Throughout this five-year study, multi-educational groups (i.e., high school, undergraduate, graduate, and postdoctoral) will be trained in systems modeling. This systems approach challenges students to incorporate environmental, social, and economic as well as technical aspects and enables modelers to simulate and visualize topics that would either be too expensive, complex or difficult to study directly (Yasar and Landau 2003). We launch this research by developing a set of multi-scale, epidemiological models of Chagas disease risk using STELLA® software v.9.1.3 (isee systems, inc., Lebanon, NH). We use this particular system dynamics software as a starting point because of its simple graphical user interface (e.g., behavior-over-time graphs, stock/flow diagrams, and causal loops). To date, high school and undergraduate students have created a set of multi-scale (i.e., homestead, village, and regional) disease models. Modeling the system at multiple spatial scales forces recognition that

  19. Carvedilol Enhances the Antioxidant Effect of Vitamins E and C in Chronic Chagas Heart Disease

    Energy Technology Data Exchange (ETDEWEB)

    Budni, Patrícia, E-mail: budnip@gmail.com [Universidade Federal de Santa Catarina, Florianópolis, SC (Brazil); Pedrosa, Roberto Coury [Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Dalmarco, Eduardo Monguilhott; Dalmarco, Juliana Bastos; Frode, Tânia Sílvia; Wilhelm, Danilo Filho [Universidade Federal de Santa Catarina, Florianópolis, SC (Brazil)

    2013-10-15

    Chagas disease is still an important endemic disease in Brazil, and the cardiac involvement is its more severe manifestation. To verify whether the concomitant use of carvedilol will enhance the antioxidant effect of vitamins E and C in reducing the systemic oxidative stress in chronic Chagas heart disease. A total of 42 patients with Chagas heart disease were studied. They were divided into four groups according to the modified Los Andes classification: 10 patients in group IA (normal electrocardiogram and echocardiogram; no cardiac involvement); 20 patients in group IB (normal electrocardiogram and abnormal echocardiogram; mild cardiac involvement); eight patients in group II (abnormal electrocardiogram and echocardiogram; no heart failure; moderate cardiac involvement); and four patients in group III (abnormal electrocardiogram and echocardiogram with heart failure; severe cardiac involvement). Blood levels of markers of oxidative stress were determined before and after a six-month period of treatment with carvedilol, and six months after combined therapy of carvedilol with vitamins E and C. The markers analyzed were as follows: activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reductase, myeloperoxidade and adenosine deaminase; and the levels of reduced glutathione, thiobarbituric-acid reactive substances, protein carbonyls, vitamin E, and nitric oxide. After treatment with carvedilol, all groups showed significant decrease in protein carbonyls and reduced glutathione levels, whereas nitric oxide levels and adenosine activity increased significantly only in the less severely affected group (IA). In addition, the activity of most of the antioxidant enzymes was decreased in the less severely affected groups (IA and IB). By combining the vitamins with carvedilol, a reduction in protein damage, in glutathione levels, and in the activity of most of the antioxidant enzymes were observed. The decrease in oxidative

  20. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

    Science.gov (United States)

    André, Philippe; Baccigalupi, Carlo; Banday, Anthony; Barbosa, Domingos; Barreiro, Belen; Bartlett, James; Bartolo, Nicola; Battistelli, Elia; Battye, Richard; Bendo, George; Benoît, Alain; Bernard, Jean-Philippe; Bersanelli, Marco; Béthermin, Matthieu; Bielewicz, Pawel; Bonaldi, Anna; Bouchet, François; Boulanger, François; Brand, Jan; Bucher, Martin; Burigana, Carlo; Cai, Zhen-Yi; Camus, Philippe; Casas, Francisco; Casasola, Viviana; Castex, Guillaume; Challinor, Anthony; Chluba, Jens; Chon, Gayoung; Colafrancesco, Sergio; Comis, Barbara; Cuttaia, Francesco; D'Alessandro, Giuseppe; Da Silva, Antonio; Davis, Richard; de Avillez, Miguel; de Bernardis, Paolo; de Petris, Marco; de Rosa, Adriano; de Zotti, Gianfranco; Delabrouille, Jacques; Désert, François-Xavier; Dickinson, Clive; Diego, Jose Maria; Dunkley, Joanna; Enßlin, Torsten; Errard, Josquin; Falgarone, Edith; Ferreira, Pedro; Ferrière, Katia; Finelli, Fabio; Fletcher, Andrew; Fosalba, Pablo; Fuller, Gary; Galli, Silvia; Ganga, Ken; García-Bellido, Juan; Ghribi, Adnan; Giard, Martin; Giraud-Héraud, Yannick; Gonzalez-Nuevo, Joaquin; Grainge, Keith; Gruppuso, Alessandro; Hall, Alex; Hamilton, Jean-Christophe; Haverkorn, Marijke; Hernandez-Monteagudo, Carlos; Herranz, Diego; Jackson, Mark; Jaffe, Andrew; Khatri, Rishi; Kunz, Martin; Lamagna, Luca; Lattanzi, Massimiliano; Leahy, Paddy; Lesgourgues, Julien; Liguori, Michele; Liuzzo, Elisabetta; Lopez-Caniego, Marcos; Macias-Perez, Juan; Maffei, Bruno; Maino, Davide; Mangilli, Anna; Martinez-Gonzalez, Enrique; Martins, Carlos J. A. P.; Masi, Silvia; Massardi, Marcella; Matarrese, Sabino; Melchiorri, Alessandro; Melin, Jean-Baptiste; Mennella, Aniello; Mignano, Arturo; Miville-Deschênes, Marc-Antoine; Monfardini, Alessandro; Murphy, Anthony; Naselsky, Pavel; Nati, Federico; Natoli, Paolo; Negrello, Mattia; Noviello, Fabio; O'Sullivan, Créidhe; Paci, Francesco; Pagano, Luca; Paladino, Rosita; Palanque-Delabrouille, Nathalie; Paoletti, Daniela; Peiris, Hiranya; Perrotta, Francesca; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Pollo, Agnieszka; Ponthieu, Nicolas; Remazeilles, Mathieu; Ricciardi, Sara; Roman, Matthieu; Rosset, Cyrille; Rubino-Martin, Jose-Alberto; Salatino, Maria; Schillaci, Alessandro; Shellard, Paul; Silk, Joseph; Starobinsky, Alexei; Stompor, Radek; Sunyaev, Rashid; Tartari, Andrea; Terenzi, Luca; Toffolatti, Luigi; Tomasi, Maurizio; Trappe, Neil; Tristram, Matthieu; Trombetti, Tiziana; Tucci, Marco; Van de Weijgaert, Rien; Van Tent, Bartjan; Verde, Licia; Vielva, Patricio; Wandelt, Ben; Watson, Robert; Withington, Stafford

    2014-02-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The data obtained will allow us to precisely measure the absolute sky brightness and polarization of all the components of the sky emission in the observed frequency range, separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM, which include: (1) the ultimate galaxy cluster survey using the Sunyaev-Zeldovich (SZ) effect, detecting approximately 106 clusters extending to large redshift, including a characterization of the gas temperature of the brightest ones (through the relativistic corrections to the classic SZ template) as well as a peculiar velocity survey using the kinetic SZ effect that comprises our entire Hubble volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where the most of the star formation in the universe took place, the faintest population of which constitute the diffuse CIB (Cosmic Infrared Background); (3) a characterization of the B modes from primordial gravity waves generated during inflation and

  1. Compact surface plasmon resonance biosensor utilizing an injection-molded prism

    Science.gov (United States)

    Chen, How-Foo; Chen, Chih-Han; Chang, Yun-Hsiang; Chuang, Hsin-Yuan

    2016-05-01

    Targeting at a low cost and accessible diagnostic device in clinical practice, a compact surface plasmon resonance (SPR) biosensor with a large dynamic range in high sensitivity is designed to satisfy commercial needs in food safety, environmental bio-pollution monitoring, and fast clinical diagnosis. The core component integrates an optical coupler, a sample-loading plate, and angle-tuning reflectors is injection-molded as a free-from prism made of plastic optics. This design makes a matching-oil-free operation during operation. The disposability of this low-cost component ensures testing or diagnosis without cross contamination in bio-samples.

  2. Research on polarization state of prism coupler sensor for measuring liquid refractive index

    Science.gov (United States)

    Zhang, Zhi-Wei

    2013-09-01

    Due to many experimental data required and a lot of calculations involved, it is very complex and cumbersome to model prism-based liquid-refractive-index-measuring methods. By use of the feature of TE-polarized wave and TM-polarized wave and differential measurement principle, we developed a new method of mathematical modeling for measuring refractive index of a liquid based upon Fresnel formula and prism internal reflection at incident angle less than critical angle. With this method only two different concentrations measurements for a kind of solution can lead to the determination of computational model. It introduces the principle of an optic-fiber sensor system based on prism-coupler for measuring refractive index of a liquid, and it contains the configuration picture of the sensing optical path, the spectrogram of the semiconductor laser and the structure block diagram of measuring system, the system is mainly made up of the semiconductor laser with 1654.14nm in wavelength, 1×2 optical switch, Y-shaped photo-coupler with coupled rate 50:50, the detector based on isosceles prism-coupler, the data process and control system based on AT89C51 and photoelectric transformer. For TM-polarized wave and TE-polarized wave, theoretical simulations show that the ratio of sensitivity is 1.11, therefore, the beam that the component of TM-polarized wave is more than the one of TE-polarized wave is advantageous to heightening the systemۥs measurement sensitivity. Measurements are performed to examine the validity of the theoretical model and four theoretical models are given, and these results indicate the feasibility of four theoretical models with an error of 3%. In this study, a beam of light is broken down into two beams in the coupler of Y-shaped coupler, the one acts as the reference optical path, the other is known as the sensing optical path, consequently the method can limit well the fluctuation of the light source, the variation of the photodiodeۥ s dark

  3. Is there a relationship between prism fusion range and vergence facility?

    OpenAIRE

    Melville, A.C.; Firth, A Y

    2002-01-01

    Aim: To investigate the relationship between prism\\ud fusion range (PFR) and vergence facility (VF)\\ud measurements in subjects with normal binocular\\ud vision.\\ud \\ud \\ud Methods: Twenty-eight subjects (mean age 19 ± 1\\ud years) with normal binocular single vision (BSV)\\ud underwent measurement of the PFR and VF in a\\ud varied order, at a test distance of 1/3 m. The PFR\\ud measurements recorded were the base out (BO) range\\ud to blur and break point and base in (BI) range to\\ud break point. ...

  4. Elasto-Optical Properties of Thin Polymer Films by Prism Coupling Technique

    Science.gov (United States)

    Ay, Feridun; Agan, Sedat; Kocabas, Askin; Aydinli, Atilla

    2004-05-01

    Reliable measurement of stress dependent refractive index of thin polymer films has been achieved. The effect of the applied stress on the refractive index and birefringence of the films was investigated. The out-of-plane elastic moduli of the thin polymer films were deduced by using the same prism coupling setup. Three dimensional finite element method (FEM) analysis was used to obtain the principal stresses for each polymer film and combining them with the stress dependent refractive index measurements, the elasto-optic coefficients of the polymer films were determined, for the first time.

  5. Negative Goos-H\\"anchen Shifts with Nano-metal-films on Prism Surface

    CERN Document Server

    Rong, Jiang; Gui-Zhen, Lu

    2012-01-01

    In recent years, the fantastic phenomena of negative Goos-H\\"anchen shifts were studied in several optics experiments with the positive refractivity materials, which is predicted by many scientists through both classical physics or quantum physics theory. In order to verify the negative Goos-H\\"anchen shifts phenomena, an experiment in microwave frequency was done with nano-metal-films on prism surface. Because using nano-metal-films enhances self-interference effect, not only were the negative Goos-H\\"anchen shifts obtained, but also the giant Goos-H\\"anchen shifts was appeared.

  6. Long range surface plasmon enhanced tunable Goos-Hanchen shift in ZnSe prism

    Science.gov (United States)

    Ghosh, Arijit; Goswami, Nabamita; Saha, Ardhendu

    2013-06-01

    This paper first time observed, designed and simulated the surface plasmon enhanced tunable Goos-Hanchen shift with varying refractive index of the dielectric layer in Kretschmann-Reather geometry formed by a ZeSe prism,50 nm silver layer, 4.5 μm liquid crystal layer (as dielectric layer) and 200 nm thin silver layer. Here the Goos-Hanchen shift is tuned from (10-72) nm with the change in refractive index of the liquid crystal layer with varying applied voltage.

  7. Cardiac Repolarization Abnormalities and Potential Evidence for Loss of Cardiac Sodium Currents on ECGs of Patients with Chagas' Heart Disease

    Science.gov (United States)

    Schlegel, T. T.; Medina, R.; Jugo, D.; Nunez, T. J.; Borrego, A.; Arellano, E.; Arenare, B.; DePalma, J. L.; Greco, E. C.; Starc, V.

    2007-01-01

    Some individuals with Chagas disease develop right precordial lead ST segment elevation in response to an ajmaline challenge test, and the prevalence of right bundle branch block (RBBB) is also high in Chagas disease. Because these same electrocardiographic abnormalities occur in the Brugada syndrome, which involves genetically defective cardiac sodium channels, acquired damage to cardiac sodium channels may also occur in Chagas disease. We studied several conventional and advanced resting 12-lead/derived Frank-lead ECG parameters in 34 patients with Chagas -related heart disease (mean age 39 14 years) and in 34 age-/gender-matched healthy controls. All ECG recordings were of 5-10 min duration, obtained in the supine position using high fidelity hardware/software (CardioSoft, Houston, TX). Even after excluding those Chagas patients who had resting BBBs, tachycardia and/or pathologic arrhythmia (n=8), significant differences remained in multiple conventional and advanced ECG parameters between the Chagas and control groups (n=26/group), especially in their respective QT interval variability indices, maximal spatial QRS-T angles and low frequency HRV powers (p=0.0006, p=0.0015 and p=0.0314 respectively). In relation to the issue of potential damage to cardiac sodium channels, the Chagas patients had: 1) greater than or equal to twice the incidence of resting ST segment elevation in leads V1-V3 (n=10/26 vs. n=5/26) and of both leftward (n=5/26 versus n=0/26) and rightward (n=7/26 versus n=3/26) QRS axis deviation than controls; 2) significantly increased filtered (40-250 Hz) QRS interval durations (92.1 8.5 versus 85.3 plus or minus 9.0 ms, p=0.022) versus controls; and 3) significantly decreased QT and especially JT interval durations versus controls (QT interval: 387.5 plus or minus 26.4 versus 408.9 plus or minus 34.6 ms, p=0.013; JT interval: 290.5 plus or minus 26.3 versus 314.8 plus or minus 31.3 ms; p=0.0029). Heart rates and Bazett-corrected QTc/JTc intervals

  8. Byen prisme

    DEFF Research Database (Denmark)

    Breitenbauch, Henrik Ø.; Winther, Mark; Jakobsen, Mikkel Broen

    Aleppo, Mosul, Kobane, Palmyra, Fallujah, Raqqa og Ramadi. Listen over byer, hvor der kæmpes eller er blevet kæmpet i Irak og Syrien, er lang. Kampen mod ISIL og den syriske borgerkrig er væsentlige eksempler på, at krigen og byerne i stigende grad er sammenhængende temaer. Verdens befolkningstal...

  9. Chronic Chagas cardiomyopathy: a review of the main pathogenic mechanisms and the efficacy of aetiological treatment following the BENznidazole Evaluation for Interrupting Trypanosomiasis (BENEFIT) trial

    Science.gov (United States)

    Rassi, Anis; Marin, José Antonio; Rassi, Anis

    2017-01-01

    Chagas cardiomyopathy is the most frequent and most severe manifestation of chronic Chagas disease, and is one of the leading causes of morbidity and death in Latin America. Although the pathogenesis of Chagas cardiomyopathy is incompletely understood, it may involve several mechanisms, including parasite-dependent myocardial damage, immune-mediated myocardial injury (induced by the parasite itself and by self-antigens), and microvascular and neurogenic disturbances. In the past three decades, a consensus has emerged that parasite persistence is crucial to the development and progression of Chagas cardiomyopathy. In this context, antiparasitic treatment in the chronic phase of Chagas disease could prevent complications related to the disease. However, according to the results of the BENEFIT trial, benznidazole seems to have no benefit for arresting disease progression in patients with chronic Chagas cardiomyopathy. In this review, we give an update on the main pathogenic mechanisms of Chagas disease, and re-examine and discuss the results of the BENEFIT trial, together with its limitations and implications. PMID:28225900

  10. SU8 3D prisms with ultra small inclined angle for low-insertion-loss fiber/waveguide interconnection.

    Science.gov (United States)

    Nguyen, Minh-Hang; Chang, Chia-Jung; Lee, Ming-Chang; Tseng, Fan-Gang

    2011-09-26

    This paper presents a simple method for fabricating SU8 three dimensional (3D) prisms with very small inclined-angles for optical-fiber/planar-waveguide interconnection with low insertion-loss by combining self-filling, molding and nano-lithography processes on plane surface. The prisms possess ultra low 3D inclined angle of 0.6° and a small surface roughness of 3.5 nm. It is demonstrated that the transmission efficiency of SOI waveguides improved about 4.6 times at the presence of SU8 prisms with a coupling loss of 11 dB per taper and radiation loss of 2.4 dB per taper.

  11. Hollow optical-fiber based infrared spectroscopy for measurement of blood glucose level by using multi-reflection prism.

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Katagiri, Takashi; Matsuura, Yuji

    2016-02-01

    A mid-infrared attenuated total reflection (ATR) spectroscopy system employing hollow optical fibers and a trapezoidal multi-reflection ATR prism has been developed to measure blood glucose levels. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. An analysis of in vivo measurements of human inner lip mucosa revealed clear signatures of glucose in the difference spectra between ones taken during the fasting state and ones taken after ingestion of glucose solutions. A calibration plot based on the absorption peak at 1155 cm(-1) that originates from the pyranose ring structure of glucose gave measurement errors less than 20%.

  12. Blood glucose measurement in vivo using hollow-fiber based, mid-infrared ATR probe with multi-reflection prism

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Matsuura, Yuji

    2016-03-01

    An attenuated-total-reflection (ATR), mid-infrared spectroscopy system that consists of hollow optical fibers, a trapezoidal multi-reflection ATR prism, and a conventional FT-IR spectrometer has been developed to measure blood glucose levels. Owing to the low transmission loss and high flexibility of the hollow-optical fiber, the system can measure any sites of the human body where blood capillaries are close to the surface of mucosa, such as inner lips. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. The results of in-vivo measurement of human inner lips showed the feasibility of the proposed system, and the measurement errors were within 20%.

  13. Investigation of optical properties of multilayer dielectric structures using prism-coupling technique

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, V I; Glebov, V N; Malyutin, A M; Molchanova, S I; Khaydukov, E V; Panchenko, V Ya [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

    2015-09-30

    A method based on resonant excitation of waveguide modes with a prism coupler is proposed for measuring the thickness and refractive index of thin-film layers in multilayer dielectric structures. The peculiarities of reflection of TE- and TM-polarised light beams from a structure comprising eleven alternating layers of zinc sulfide (ZnS) and magnesium barium fluoride (MgBaF{sub 4}), whose thicknesses are much less than the wavelength of light, are investigated. Using the mathematical model developed, we have calculated the coefficients of reflection of collimated TE and TM light beams from a multilayer structure and determined the optical constants and thicknesses of the structure layers. The refractive indices of the layers, obtained for TE and TM polarisation of incident light, are in good agreement. The thicknesses of ZnS and MgBaF{sub 4} layers, found for different polarisations, coincide with an accuracy of ±1%. Thus, we have demonstrated for the first time that the prism-coupling technique allows one to determine the optical properties of thin-film structures when the number of layers in the structure exceeds ten layers. (integrated optics)

  14. Microbial methane production in deep aquifer associated with the accretionary prism in Japan.

    Science.gov (United States)

    Kimura, Hiroyuki; Nashimoto, Hiroaki; Shimizu, Mikio; Hattori, Shohei; Yamada, Keita; Koba, Keisuke; Yoshida, Naohiro; Kato, Kenji

    2010-04-01

    To identify the methanogenic pathways present in a deep aquifer associated with an accretionary prism in Southwest Japan, a series of geochemical and microbiological studies of natural gas and groundwater derived from a deep aquifer were performed. Stable carbon isotopic analysis of methane in the natural gas and dissolved inorganic carbon (mainly bicarbonate) in groundwater suggested that the methane was derived from both thermogenic and biogenic processes. Archaeal 16S rRNA gene analysis revealed the dominance of H(2)-using methanogens in the groundwater. Furthermore, the high potential of methane production by H(2)-using methanogens was shown in enrichments using groundwater amended with H(2) and CO(2). Bacterial 16S rRNA gene analysis showed that fermentative bacteria inhabited the deep aquifer. Anaerobic incubations using groundwater amended with organic substrates and bromoethanesulfonate (a methanogen inhibitor) suggested a high potential of H(2) and CO(2) generation by fermentative bacteria. To confirm whether or not methane is produced by a syntrophic consortium of H(2)-producing fermentative bacteria and H(2)-using methanogens, anaerobic incubations using the groundwater amended with organic substrates were performed. Consequently, H(2) accumulation and rapid methane production were observed in these enrichments incubated at 55 and 65 degrees C. Thus, our results suggested that past and ongoing syntrophic biodegradation of organic compounds by H(2)-producing fermentative bacteria and H(2)-using methanogens, as well as a thermogenic reaction, contributes to the significant methane reserves in the deep aquifer associated with the accretionary prism in Southwest Japan.

  15. A beam-displacement prism based, three band stellar photo-polarimeter

    CERN Document Server

    Raveendran, A V; Muneer, S; Mekkaden, M V; Jayavel, N; Somashekar, M R; Sagayanathan, K; Ramamoorthy, S; Rosario, M J; Jayakumar, K

    2015-01-01

    A new astronomical photo-polarimeter that can measure linear polarization of point sources simultaneously in three spectral bands was designed and built in Indian Institute of Astrophysics. The polarimeter has a Calcite beam-displacement prism as the analyzer. The ordinary and extra-ordinary emerging beams in each spectral band are quasi-simultaneously detected by the same photomultiplier by using a high speed rotating chopper. The effective chopping frequency can be set to as high as 200 Hz. A rotating superachromatic Pancharatnam halfwave plate is used to modulate the light incident on the analyzer. The spectral bands are isolated using appropriate dichroic and glass filters. A detailed analysis shows that the reduction of 50% in the efficiency of the polarimeter because of the fact that the intensities of the two beams are measured alternately is partly compensated by the reduced time to be spent on the observation of the sky background. The position angle of polarization produced by the Glan-Taylor prism ...

  16. Rapid growth of ZnO hexagonal prism crystals by direct microwave heating

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhenqi; ZHOU Jian; LIU Guizhen; REN Zhiguo

    2008-01-01

    ZnO hexagonal prism crystals were synthesized from ZnO powders by microwave heating in a short time (within 20 min) without any metal catalyst or transport agent.Zinc oxide raw materials were made by evaporating from the high-temperature zone in an enclosure atmosphere and crystals were grown on the self-source substrate.The inherent asymmetry in microwave heating provides the temperature gradient for crystal growth.Substrate and temperature distribution in the oven show significant effects on the growth of the ZnO crystal.The morphologies demonstrate that these samples are pure hexagonal prism crystals with maximum 80 μm in diameter and 600 μm in length,which possess a well faceted end and side surface.X-ray diffraction (XRD) reveals that these samples are pure crystals.The photoluminescence (PL) exhibits strong ultraviolet emission at room temperature,indicating potential applications for short-wave light-emitting photonic devices.

  17. Morphine enhances the release of /sup 3/H-purines from rat brain cerebral cortical prisms

    Energy Technology Data Exchange (ETDEWEB)

    Wu, P.H.; Phillis, J.W.; Yuen, H.

    1982-10-01

    In vitro experiments have shown that /sup 3/H-purines can be released from /sup 3/H-adenosine preloaded rat brain cortical prisms by a KCl-evoked depolarization. The KCl-evoked release of /sup 3/H-purines is dependent on the concentration of KCl present in the superfusate. At concentrations of 10(-7) approximately 10(-5)M morphine did not influence the basal release of /sup 3/H-purines from the prisms, although it enhanced the KCl-evoked release of /sup 3/H-purines. The enhancement of KCl-evoked /sup 3/H-purine release by morphine was concentration-dependent and was antagonized by naloxone, suggesting the involvement of opiate receptors. Uptake studies with rat brain cerebral cortical synaptosomes show that morphine is a very weak inhibitor of adenosine uptake. Comparisons with dipyridamole, a potent inhibitor of adenosine uptake, suggest that this low level of inhibition of the uptake did not contribute significantly to the release of /sup 3/H-purine by morphine seen in our experiments. It is therefore suggested that morphine enhances KCl-evoked /sup 3/H-purine release by an interaction with opiate receptors and that the resultant increase in extracellular purine (adenosine) levels may account for some of the actions of morphine.

  18. Analysis of a shearography device using a Wollaston prism and polarization phase shifting

    Science.gov (United States)

    Sanchez, E.; Benedet, M. E.; Willemann, D. P.; Fantin, A. V.; Albertazzi, A. G.

    2016-08-01

    Speckle shear interferometry, or shearography, has been more and more frequently used in the industry for in-field nondestructive inspections of flaws in composite materials used in the aerospace and oil and gas industry. Nowadays new applications has emerged demanding the ability to operate in harsher environments. Bringing interferometric systems to harsh environments is not an easy task since they are very sensitive to many harsh environmental factors. Due to the quasi-equal-path property, shearography is an intrinsically robust interferometric technique that has been successfully used in the field, but there are still limits to overcome. Mechanical vibrations are probably the most challenging factor to cope in the field measurements. This work presents a potentially robust shear interferometer configuration. It uses a Wollaston prism as the shearing element rather than a traditional Michelson interferometer and polarizers to achieve the phase shift. The use of the Wollaston prism makes the optical setup more compact and robust, given that a rotating polarizer is the only movable part of the interferometer.

  19. Inventory and Review of Existing PRISM Hydrogeologic Data for the Islamic Republic of Mauritania, Africa

    Science.gov (United States)

    Friedel, Michael J.

    2008-01-01

    The USGS entered into an agreement with the Mauritania Ministry of Mines and Industry to inventory and review the quality of information collected as part of the Project for Strengthening of the Institutions in the Mining Sector (PRISM). Whereas the PRISM program collected geophysical, geochemical, geological, satellite, and hydrogeologic information, this report focuses on an inventory and review of available hydrogeologic data provided to the USGS in multiple folders, files, and formats. Most of the information pertained to the hydrogeologic setting and the water budget of evaporation, evapotranspiration, and precipitation in the Choum-Zouerate area in northwestern Mauritania, and the country of Mauritania itself. Other information about the quantity and quality of groundwater was found in the relational Access database. In its present form, the limited hydrogeologic information was not amenable to conducting water balance, geostatistical, and localized numerical modeling studies in support of mineral exploration and development. Suggestions are provided to remedy many of the data's shortcomings, such as performing quality assurance on all SIPPE2 data tables and sending questionnaires to appropriate agencies, mining and other companies to populate the database with additional meteorology, hydrology, and groundwater data.

  20. Calibration of miniature prism-based stereoscopic imagers for precise spatial measurements

    Science.gov (United States)

    Machikhin, Alexander S.; Gorevoy, Alexey V.

    2016-04-01

    The paper is targeted to find the optimal mathematical model and the calibration algorithm for the industrial endoscope equipped with the prism-based attachable stereo adapter, which allows imaging from two different points by a single sensor. We consider the conventional calibration methods for the pinhole camera model with polynomial distortion approximation and compared them with the ray tracing model based on the vector form of Snell's law. In order to evaluate each of the proposed models we have developed the software for the imitation of various calibration procedures using different types of calibration targets. We use the computer simulation to prove that the pinhole camera models, widely used in machine vision, are very limited for describing prism-based endoscopic measurement systems. Our analysis identified the main problems for these models, such as entrance pupil shift, non-homocentric beams and required number of coefficients for polynomial models and the iterative forward ray aiming for the ray-tracing model. The proposed technique is flexible and can also be used to test stability and convergence of the parameter estimation procedures and to compare calibration targets and strategies.

  1. Reading performance is not affected by a prism induced increase of horizontal and vertical vergence demand

    Directory of Open Access Journals (Sweden)

    Muriel eDysli

    2014-06-01

    Full Text Available Purpose Dyslexia is the most common developmental reading disorder that affects language skills. Latent strabismus (heterophoria has been suspected to be causally involved. Even though phoria correction in dyslexic children is commonly applied, the evidence in support of a benefit is poor. In order to provide experimental evidence on this issue, we simulated phoria in healthy readers by modifying the vergence tone required to maintain binocular alignment. MethodsVergence tone was altered with prisms that were placed in front of one eye in 16 healthy subjects to induce exophoria, esophoria, or vertical phoria. Subjects were to read one paragraph for each condition, from which reading speed was determined. Text comprehension was tested with a forced multiple choice test. Eye movements were recorded during reading and subsequently analysed for saccadic amplitudes, saccades per 10 letters, percentage of regressive (backward saccades, average fixation duration, first fixation duration on a word, and gaze duration.ResultsAcute change of horizontal and vertical vergence tone does neither significantly affect reading performance nor reading associated eye movements. Conclusion Prisms in healthy subjects fail to induce a significant change of reading performance. This finding is not compatible with a role of phoria in dyslexia. Our results contrast the proposal for correcting small angle heterophorias in dyslexic children.

  2. Design of the infrared imaging chain for the PRISM hyperspectral imager

    Science.gov (United States)

    Dartois, Thierry; Giordanengo, Muriel; Ribet, Jean-Luc; Del Bello, Umberto

    2000-12-01

    ALCATEL has recently studied an infrared imaging chain, in the frame of phase A studies for the Land Surface Processes and Interactions Mission (LSPIM), which was one of the four candidate Core Missions for the European Space Agency Earth Explorer Program. The LSPIM satellite carries a single optical payload named PRISM (Processes Research by an Imaging Space Mission). PRISM is a multispectral imager based on the push broom imaging principle, operating at approximately 679 km altitude with a NADIR swath of 50 km associated to a 50 m spatial resolution. The paper presented herewith summarizes the results of the IR imaging chains study: composed of two IR focal planes (SWIR and TIR) integrated in dedicated ALCATEL dewars (one for each FPA), two proximity electronic modules and a common analog processing unit delivering digital video data to the one board mass memory unit (MMU). The main specifications of the detectors and electronic units are presented, a baseline of the imaging chain architecture complying with the requirements is then proposed with the main achieved trades off. The concept and associated performances of cutting-edge cooling systems are also introduced in this paper.

  3. Development and commissioning of a double-prism spectrometer for the diagnosis of femtosecond electron bunches

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, Steffen

    2016-12-15

    Free-electron lasers as accelerator-driven light sources and wakefield-based acceleration in plasmas require the knowledge of the longitudinal extension and the longitudinal current profile of the involved electron bunches. These bunches can yield lengths below 10 μm, or durations shorter than approx. 33 fs, as well as charges less than 30 pC. During this work, transition radiation from relativistic electron bunches was investigated in the mid-infrared wavelength regime. A spectrometer using an arrangement of two consecutive zinc selenide prisms was developed, built and commissioned. The instrument covers the spectral range from 2 μm to 18 μm in a single shot. Measurements with the double-prism spectrometer were conducted at the FEL facilities FLASH at DESY in Hamburg, Germany and FELIX at the Radboud Universiteit in Nijmegen, The Netherlands. The assessment of the spectrometer and comparative studies with established diagnostic devices at FLASH show high signal-to-noise ratios at bunch charges below 10 pC and confirm the obtained results.

  4. [Research on fiber methane sensing system based on prism gas cell].

    Science.gov (United States)

    Wu, Xi-Jun; Wang, Yu-Tian; Liu, Xue-Cai; Li, Shu-Jun

    2010-05-01

    A novel fiber methane detection system was constructed based on integration of prism gas cell and harmonic detection technique. The system can be applied to broad-range concentration detection. Grounded on the Beer-Lambert approximation, the detection of various concentration (0-20%) of methane was completed using subtraction of background and ratio processing method, as the atmosphere surroundings was treated as background. The direct absorption spectra for various concentration were measured using GRIN gas cell, combined with available DFB-LD, and the R5 line of the 2v3 band of methane was selected as absorption peak. The system was tested online during gas mixing process and the linear relation between system indication and concentration variation was validated, while the stability and dynamic response characteristics was confirmed by experiments. The system sensitivity can be adjusted according to the concentration level of various field environments by changing the prism distance using step motor. So that, the system can be applied to various application fields and can be adopted as a monitoring instrument for coalmine tunnel and natural gas pipeline.

  5. The PRIsm MUlti-object Survey (PRIMUS). II. Data Reduction and Redshift Fitting

    CERN Document Server

    Cool, Richard J; Blanton, Michael R; Burles, Scott M; Coil, Alison L; Eisenstein, Daniel J; Wong, Kenneth C; Zhu, Guangtun; Aird, James; Bernstein, Rebecca A; Bolton, Adam S; Hogg, David W; Mendez, Alexander J

    2013-01-01

    The PRIsm MUti-object Survey (PRIMUS) is a spectroscopic galaxy redshift survey to z~1 completed with a low-dispersion prism and slitmasks allowing for simultaneous observations of ~2,500 objects over 0.18 square degrees. The final PRIMUS catalog includes ~130,000 robust redshifts over 9.1 sq. deg. In this paper, we summarize the PRIMUS observational strategy and present the data reduction details used to measure redshifts, redshift precision, and survey completeness. The survey motivation, observational techniques, fields, target selection, slitmask design, and observations are presented in Coil et al 2010. Comparisons to existing higher-resolution spectroscopic measurements show a typical precision of sigma_z/(1+z)=0.005. PRIMUS, both in area and number of redshifts, is the largest faint galaxy redshift survey completed to date and is allowing for precise measurements of the relationship between AGNs and their hosts, the effects of environment on galaxy evolution, and the build up of galactic systems over t...

  6. Improving detection tools for the emerald ash borer (Coleoptera: Buprestidae): comparison of prism and multifunnel traps at varying population densities.

    Science.gov (United States)

    Francese, Joseph A; Rietz, Michael L; Crook, Damon J; Fraser, Ivich; Lance, David R; Mastro, Victor C

    2013-12-01

    The current emerald ash borer survey trap used in the United States is a prism trap constructed from a stock purple corrugated plastic. In recent years, several colors (particularly shades of green and purple) have been shown to be more attractive to the emerald ash borer than this stock color. Our goal was to determine if plastics produced with these colors and incorporated into prism traps can improve and serve as a new alternative to plastics already in use for the emerald ash borer survey. The plastics were tested in moderate to heavily infested areas in Michigan in two initial studies to test their effectiveness at catching the emerald ash borer. Because results from studies performed in heavily infested sites may not always correspond with what is found along the edges of the infestation, we compared trap catch and detection rates (recording at least one catch on a trap over the course of the entire trapping season) of several trap types and colors at sites outside the core of the currently known emerald ash borer infestation in a nine-state detection tool comparison study. Two of the new plastics, a (Sabic) purple and a medium-dark (Sabic) green were incorporated into prism traps and tested alongside a standard purple prism trap and a green multifunnel trap. In areas with lower emerald ash borer density, the new purple (Sabic) corrugated plastic caught more beetles than the current purple prism trap, as well as more than the medium-dark green (Sabic) prism and green multifunnel traps. Sabic purple traps in the detection tools comparison study recorded a detection rate of 86% compared with 73, 66, and 58% for the standard purple, Sabic green, and green multifunnel traps, respectively. These detection rates were reduced to 80, 63, 55, and 46%, respectively, at low emerald ash borer density sites.

  7. Do Brazilian scientific journals promote the adherence of Chagas disease researchers to internacional ethical principals?

    Directory of Open Access Journals (Sweden)

    Guilherme Malafaia

    2013-06-01

    Full Text Available The ethical aspects of the Brazilian publications about human Chagas disease (CD developed between 1996 and 2010 and the policy adopted by Brazilian medical journals were analyzed. Articles were selected on the SciELO Brazil data basis, and the evaluation of ethical aspects was based on the normative contents about ethics in research involving human experimentation according to the Brazilian resolution of the National Health Council no. 196/1996. The editorial policies of the section "Instructions to authors" were analyzed. In the period of 1996-2012, 58.9% of articles involving human Chagas disease did not refer to the fulfillment of the ethical aspects concerning research with human beings. In 80% of the journals, the requirements and confirmation of the information about ethical aspects in the studies of human CD were not observed. Although a failure in this type of service is still observed, awareness has been raised in federal agencies, educational institutions/research and publishing groups to standardize the procedures and ethical requirements for the Brazilian journals, reinforcing the fulfillment of the ethical parameters, according to the resolution of NHC no. 196/1996.

  8. [Chagas disease in chronic phase outside the endemic area. The diagnostic tools].

    Science.gov (United States)

    Paris, L; Touafek, F; Elghouzzi, M H; Chérif, S; Mazier, D

    2009-12-01

    The diagnosis of Chagas disease during the chronic phase is based on serology. Outside South America the use of two methods is recommended by WHO. A third method must be available for inconclusive results but there is no gold standard. A pilot study of screening in 254 Bolivian people living in the Paris area (France) was made. Serological study was performed using IIF and three Elisa, Elisa Cruzi (BioMérieux Brésil), BioElisa Chagas (Bio-kit), and Chagatest Elisa recombinante v. 3.0 (Wiener Lab). 165 patients were negative, 69 positive and 20 inconclusive. PCR-based assays appear to have a better sensitivity than parasitological methods, but not more than 70% that do not justify their use for primary testing. There are no standardized and commercial assays. The primer pairs based on the nuclear sequence TCZ1-TCZ2 seems to be the more specific (no cross reaction with others Trypanosomatidae) and the most sensitive with the strains of the two lineage of Trypanosoma cruzi. PCR would have a role in inconclusive serological cases or in the evaluation of treatment failure.

  9. Entomological factors affecting the low endemicity of Chagas disease in Nazca, Southwestern Peru.

    Science.gov (United States)

    Paredes-Esquivel, Claudia; Lecaros, Emilio; Aguliar-Rosales, Mauro; Acosta, Hilda Solis; Castellanos, Pedro

    2010-05-01

    Chagas disease is prevalent in Peru. The province of Nazca, in the southwestern region of the country, shows a high intradomiciliary infestation rate of Triatoma infestans bugs. Although the vector is present, the number of Chagas disease cases appears to be much lower than those reported in the neighboring region of Arequipa. We examined 624 T. infestans from Nazca to determine the current Trypanosoma cruzi infection rates, and found that no bugs were infected with this parasite. These results contrast with those found in Arequipa, where 19-30% triatomines have been reported infected. To compare their vectorial capacity, we infected 30 T. infestans specimens, selected both from Nazca and Arequipa, by feeding bugs on T. cruzi-infected mice. The parasites developed all stages expected in the vector; furthermore, the infective stage, metacyclic trypomastigote, was found in both insect populations from the second week after infection. In addition, those insects that accepted to be fed with mice blood defecated immediately after finishing blood meal, indicating that they might be efficient vectors. We maintain that differences observed in infection rates between vectors from Nazca and Arequipa may be explained by differences in host availability. In Arequipa hosts are mainly small animals, whereas in Nazca the main blood source comes from birds, which are refractory to the infection.

  10. Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease

    Directory of Open Access Journals (Sweden)

    Fátima Palha de Oliveira

    2000-12-01

    Full Text Available OBJECTIVE: To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical/hemodynamic classification. METHODS: We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical/hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram/echocardiogram, 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram, 14 patients in group II (abnormal electrocardiogram/echocardiogram, without congestive heart failure, and 12 patients in group III (abnormal electrocardiogram/echocardiogram with congestive heart failure. The following variables were analyzed: oxygen consumption (V O2, carbon dioxide production (V CO2, gas exchange rate (R, inspiratory current volume (V IC, expiratory current volume (V EC, respiratory frequency, minute volume (V E, heart rate (HR, maximum load, O2 pulse, and ventilatory anaerobic threshold (AT. RESULTS: When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2peak, V CO2peak, V ICpeak, V ECpeak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III. CONCLUSION: The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.

  11. Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method.

    Science.gov (United States)

    Lázzari, J O; Pereira, M; Antunes, C M; Guimarães, A; Moncayo, A; Chávez Domínguez, R; Hernández Pieretti, O; Macedo, V; Rassi, A; Maguire, J; Romero, A

    1998-11-01

    An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (kappa) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (kappa = 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

  12. Chagas disease in Mexico: an analysis of geographical distribution during the past 76 years - A review

    Directory of Open Access Journals (Sweden)

    Alejandro Cruz-Reyes

    2006-06-01

    Full Text Available Literature from 1928 through 2004 was compiled from different document sources published in Mexico or elsewhere. From these 907 publications, we found 19 different topics of Chagas disease study in Mexico. The publications were arranged by decade and also by state. This information was used to construct maps describing the distribution of Chagas disease according to different criteria: the disease, vectors, reservoirs, and strains. One of the major problems confronting study of this zoonotic disease is the great biodiversity of the vector species; there are 30 different species, with at least 10 playing a major role in human infection. The high variability of climates and biogeographic regions further complicate study and understanding of the dynamics of this disease in each region of the country. We used a desktop Genetic Algorithm for Rule-Set Prediction procedure to provide ecological models of organism niches, offering improved flexibility for choosing predictive environmental and ecological data. This approach may help to identify regions at risk of disease, plan vector-control programs, and explore parasitic reservoir association. With this collected information, we have constructed a data base: CHAGMEX, available online in html format.

  13. Impact of Chagas Disease in Bolivian Immigrants Living in Europe and the Risk of Stigmatization

    Directory of Open Access Journals (Sweden)

    Rafael M. Ortí-Lucas

    2014-01-01

    Full Text Available Background. The prevalence of Chagas disease in endemic countries varies with the kind of vector involved and the socioeconomic conditions of the population of origin. Due to recent immigration it is an emerging public health problem in Europe, especially in those countries which receive immigrant populations with a high prevalence of carriers. The study reviews the impact of the disease on Bolivian immigrants living in Europe, the preventive measures and regulations applied in European countries, and their repercussion on possible stigmatization of certain population groups. Methods. The Bolivian immigrant population resident in 2012 was estimated and the affected population in different European countries was calculated with data on carrier prevalence that were recently published. The preventive measures and regulations available in Europe were also reviewed. MEDLINE-PubMed, GoPubMed, and Embase were consulted for the literature review. Results. The Bolivian immigrant population has the highest prevalence of Chagas carriers (6.7%–25% compared to the overall Latin American population (1.3%–2.4%. Only in Spain, France, Belgium, UK, Portugal, Italy, Switzerland, The Netherlands, and Germany, preventive measures are applied to this population. The established regulations are insufficient and completely different criteria are applied in the different countries and this could reflect a certain degree of stigmatization.

  14. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    Science.gov (United States)

    Fabbro, Diana L; Danesi, Emmaria; Olivera, Veronica; Codebó, Maria Olenka; Denner, Susana; Heredia, Cecilia; Streiger, Mirtha; Sosa-Estani, Sergio

    2014-11-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 "chronically infected mother-biological child" pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%), whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0%) (pChagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up.

  15. Usefulness of serology for the evaluation of Trypanosoma cruzi transmission in endemic areas of Chagas' disease

    Directory of Open Access Journals (Sweden)

    Roberto Chuit

    1989-09-01

    Full Text Available Thirteen communities from 7 Argentinian provinces were selected for the evaluation of serology as an indicator of transmission of Chagas disease. Of the communities appraised, 6 did not have a history of previous treatment with insecticides and 7 had received sporadic or continuous insecticide treatment. The inhabitants of 20% of the houses of each locality were studied by serology. The samples were obtained byfinger pricking and 50 fil of blood were mixed with 150μl of 50% glycerine solution in tissue culture media to be assayed by Indirect Hemagglutination and Indirect Immunofluorescence tests. In untreated areas, the prevalence of infection in infants 0-4 years old was 17.5%, reaching to over 22% for the 5-9 year old group, and to 33.3% in 10-14 year old individuals. The prevalence in treated and surveyed areas was 2.6% in 0-4 year old children, 5.4% in 5-9 year old and 6,2% in 10-14 year old youngsters. The differences between both areas were statistically significant (p < 0.005. This study favors serology as a valid indicator for the evaluation of transmission of Chagas disease in rural areas.

  16. Parasite prolyl oligopeptidases and the challenge of designing chemotherapeuticals for Chagas disease, leishmaniasis and African trypanosomiasis.

    Science.gov (United States)

    Bastos, I M D; Motta, F N; Grellier, P; Santana, J M

    2013-01-01

    The trypanosomatids Trypanosoma cruzi, Leishmania spp. and Trypanosoma brucei spp. cause Chagas disease, leishmaniasis and human African trypanosomiasis, respectively. It is estimated that over 10 million people worldwide suffer from these neglected diseases, posing enormous social and economic problems in endemic areas. There are no vaccines to prevent these infections and chemotherapies are not adequate. This picture indicates that new chemotherapeutic agents must be developed to treat these illnesses. For this purpose, understanding the biology of the pathogenic trypanosomatid- host cell interface is fundamental for molecular and functional characterization of virulence factors that may be used as targets for the development of inhibitors to be used for effective chemotherapy. In this context, it is well known that proteases have crucial functions for both metabolism and infectivity of pathogens and are thus potential drug targets. In this regard, prolyl oligopeptidase and oligopeptidase B, both members of the S9 serine protease family, have been shown to play important roles in the interactions of pathogenic protozoa with their mammalian hosts and may thus be considered targets for drug design. This review aims to discuss structural and functional properties of these intriguing enzymes and their potential as targets for the development of drugs against Chagas disease, leishmaniasis and African trypanosomiasis.

  17. Mitigating social and health inequities: community participation and Chagas disease in rural Argentina.

    Science.gov (United States)

    Llovet, Ignacio; Dinardi, Graciela; De Maio, Fernando G

    2011-01-01

    Chagas disease (CD) causes 12,500 deaths annually in Latin America. As a neglected disease primarily associated with poverty, it is a major driver of health inequity. Argentina's efforts to control vector transmission have been unsuccessful. Using new survey data (n=400 households), we compare the social patterning of the burden of CD by examining socio-demographic predictors of self-reported CD and the presence of vinchucas in two areas of rural northern Argentina known to have experienced different interventions in surveillance and control. Our analyses suggest that Avellaneda, an area known for horizontal intervention strategies which nurture community participation is quite distinct from Silipica, an area which has experienced a vertical intervention strategy since 1990. Avellaneda has higher level of self-reported Chagas infection and lower level of vinchuca presence; Silipica has pronounced and statistically significant differences patterned by the head of household's level of educational attainment. A greater awareness of the disease and its transmission, along with community mobilisation and spraying, may bring about more self-reported CD and less vinchuca presence in Avellaneda than in Silipica. This suggests that strategies based on community participation may be effective in reducing the social patterning of the burden of disease, even in poor places.

  18. Impact of Chagas Disease in Bolivian Immigrants Living in Europe and the Risk of Stigmatization

    Science.gov (United States)

    Ortí-Lucas, Rafael M.; Parada-Barba, María C.; de la Rubia-Ortí, José E.; Carrillo-Ruiz, Alejandra; Beso-Delgado, María; Boone, An L. D.

    2014-01-01

    Background. The prevalence of Chagas disease in endemic countries varies with the kind of vector involved and the socioeconomic conditions of the population of origin. Due to recent immigration it is an emerging public health problem in Europe, especially in those countries which receive immigrant populations with a high prevalence of carriers. The study reviews the impact of the disease on Bolivian immigrants living in Europe, the preventive measures and regulations applied in European countries, and their repercussion on possible stigmatization of certain population groups. Methods. The Bolivian immigrant population resident in 2012 was estimated and the affected population in different European countries was calculated with data on carrier prevalence that were recently published. The preventive measures and regulations available in Europe were also reviewed. MEDLINE-PubMed, GoPubMed, and Embase were consulted for the literature review. Results. The Bolivian immigrant population has the highest prevalence of Chagas carriers (6.7%–25%) compared to the overall Latin American population (1.3%–2.4%). Only in Spain, France, Belgium, UK, Portugal, Italy, Switzerland, The Netherlands, and Germany, preventive measures are applied to this population. The established regulations are insufficient and completely different criteria are applied in the different countries and this could reflect a certain degree of stigmatization. PMID:24719753

  19. Aptamer-based detection of disease biomarkers in mouse models for chagas drug discovery.

    Directory of Open Access Journals (Sweden)

    Fernanda Fortes de Araujo

    2015-01-01

    Full Text Available Drug discovery initiatives, aimed at Chagas treatment, have been hampered by the lack of standardized drug screening protocols and the absence of simple pre-clinical assays to evaluate treatment efficacy in animal models. In this study, we used a simple Enzyme Linked Aptamer (ELA assay to detect T. cruzi biomarker in blood and validate murine drug discovery models of Chagas disease. In two mice models, Apt-29 ELA assay demonstrated that biomarker levels were significantly higher in the infected group compared to the control group, and upon Benznidazole treatment, their levels reduced. However, biomarker levels in the infected treated group did not reduce to those seen in the non-infected treated group, with 100% of the mice above the assay cutoff, suggesting that parasitemia was reduced but cure was not achieved. The ELA assay was capable of detecting circulating biomarkers in mice infected with various strains of T. cruzi parasites. Our results showed that the ELA assay could detect residual parasitemia in treated mice by providing an overall picture of the infection in the host. They suggest that the ELA assay can be used in drug discovery applications to assess treatment efficacy in-vivo.

  20. Aptamer-based detection of disease biomarkers in mouse models for chagas drug discovery.

    Science.gov (United States)

    de Araujo, Fernanda Fortes; Nagarkatti, Rana; Gupta, Charu; Marino, Ana Paula; Debrabant, Alain

    2015-01-01

    Drug discovery initiatives, aimed at Chagas treatment, have been hampered by the lack of standardized drug screening protocols and the absence of simple pre-clinical assays to evaluate treatment efficacy in animal models. In this study, we used a simple Enzyme Linked Aptamer (ELA) assay to detect T. cruzi biomarker in blood and validate murine drug discovery models of Chagas disease. In two mice models, Apt-29 ELA assay demonstrated that biomarker levels were significantly higher in the infected group compared to the control group, and upon Benznidazole treatment, their levels reduced. However, biomarker levels in the infected treated group did not reduce to those seen in the non-infected treated group, with 100% of the mice above the assay cutoff, suggesting that parasitemia was reduced but cure was not achieved. The ELA assay was capable of detecting circulating biomarkers in mice infected with various strains of T. cruzi parasites. Our results showed that the ELA assay could detect residual parasitemia in treated mice by providing an overall picture of the infection in the host. They suggest that the ELA assay can be used in drug discovery applications to assess treatment efficacy in-vivo.

  1. Bibliometric assessment of the contributions of literature on Chagas disease in Latin America and the Caribbean.

    Science.gov (United States)

    Delgado-Osorio, Nathalia; Vera-Polania, Felipe; Lopez-Isaza, Andres F; Martinez-Pulgarin, Dayron F; Murillo-Abadia, Jonathan; Munoz-Urbano, Marcela; Cardona-Ospina, Jaime A; Bello, Ricardo; Lagos-Grisales, Guillermo J; Villegas-Rojas, Soraya; Rodriguez-Morales, Alfonso J

    2014-01-01

    Chagas disease, considered a parasitic neglected disease, is endemic in Latin America. Although, its mortality rate has decreased over time, it still represents a public health problem in the region. A bibliometric evaluation of the Latin American contributions on this disease was done. This study used SCI (1980-2013), MEDLINE/GOPUBMED (1802-2013), Scopus (1959-2013), SCIELO (2004-2013), and LILACS (1980-2013). Different study types have been characterized by years, origin city/country, journals and most productive authors, by country, cites and H-index. 2988 articles were retrieved from SCI (30.85% of total). Brazil was found to be the highest producer (31.22%), followed by Argentina (18.14%) and México (9.57%); the region received 47241 citations, 28.60% for Brazil (H-index=52), 18.26% of Argentina (Hindex= 43), 11.40% Bolivia (H-index=37). 4484 were retrieved from Scopus (30.20% of the total), 38.58% of which were from Brazil, 12.40% from Argentina and 8.90% from Mexico. From Medline, 6647 records were retrieved (45.58% Brazil). From SciELO, 917 articles (47.66% Brazil). From LILACS, 2165 articles (60.05% Brazil). Brazil has the highest output in the region. Despite advances in controlling Chagas disease, scientific production is low, particularly for regional bibliographic databases, which calls for more research on this disease.

  2. Rational spatio-temporal strategies for controlling a Chagas disease vector in urban environments.

    Science.gov (United States)

    Levy, Michael Z; Malaga Chavez, Fernando S; Cornejo Del Carpio, Juan G; Vilhena, Daril A; McKenzie, F Ellis; Plotkin, Joshua B

    2010-07-06

    The rational design of interventions is critical to controlling communicable diseases, especially in urban environments. In the case of the Chagas disease vector Triatoma infestans, successful control is stymied by the return of the insect after the effectiveness of the insecticide wanes. Here, we adapt a genetic algorithm, originally developed for the travelling salesman problem, to improve the spatio-temporal design of insecticide campaigns against T. infestans, in a complex urban environment. We find a strategy that reduces the expected instances of vector return 34-fold compared with the current strategy of sequential insecticide application to spatially contiguous communities. The relative success of alternative control strategies depends upon the duration of the effectiveness of the insecticide, and it shows chaotic fluctuations in response to unforeseen delays in a control campaign. We use simplified models to analyse the outcomes of qualitatively different spatio-temporal strategies. Our results provide a detailed procedure to improve control efforts for an urban Chagas disease vector, as well as general guidelines for improving the design of interventions against other disease agents in complex environments.

  3. Cardiac Magnetic Resonance-Verified Myocardial Fibrosis in Chagas Disease: Clinical Correlates and Risk Stratification

    Science.gov (United States)

    Uellendahl, Marly; de Siqueira, Maria Eduarda Menezes; Calado, Eveline Barros; Kalil-Filho, Roberto; Sobral, Dário; Ribeiro, Clébia; Oliveira, Wilson; Martins, Silvia; Narula, Jagat; Rochitte, Carlos Eduardo

    2016-01-01

    Background Chagas disease (CD) is an important cause of heart failure and mortality, mainly in Latin America. This study evaluated the morphological and functional characteristics of the heart as well the extent of myocardial fibrosis (MF) in patients with CD by cardiac magnetic resonance (CMR). The prognostic value of MF evaluated by myocardial-delayed enhancement (MDE) was compared with that via Rassi score. Methods This study assessed 39 patients divided into 2 groups: 28 asymptomatic patients as indeterminate form group (IND); and symptomatic patients as Chagas Heart Disease (CHD) group. All patients underwent CMR using the techniques of cine-MRI and MDE, and the amount of MF was compared with the Rassi score. Results Regarding the morphological and functional analysis, significant differences were observed between both groups (p < 0.001). Furthermore, there was a strong correlation between the extent of MF and the Rassi score (r = 0.76). Conclusions CMR is an important technique for evaluating patients with CD, stressing morphological and functional differences in all clinical presentations. The strong correlation with the Rassi score and the extent of MF detected by CMR emphasizes its role in the prognostic stratification of patients with CD. PMID:27982271

  4. Chronic Chagas cardiopathy in Chile. Importance of Trypanosoma cruzi burden and clinical evaluation.

    Science.gov (United States)

    Apt, Werner; Arribada, Arturo; Zulantay, Inés; Saavedra, Miguel; Muñoz, Catalina; Toro, Bruno; Vega, Bastián; Rodríguez, Jorge

    2016-10-01

    Currently there are no biological markers to indicate which individuals with chronic indeterminate period of Chagas disease develop heart disease and who will remain all his life in this phase. The aim of this survey was to determine if Trypanosoma cruzi burden is related to the presence of heart disease in patients with chronic Chagas disease. 200 patients who had not been treated, 100 with cardiopathy and 100 without, groups A and B respectively, were submitted to clinical study and electrocardiogram, Echo-Doppler was performed for group A in which all important known causes of cardiopathy were discarded. In both groups xenodiagnosis, conventional PCR and quantitative PCR were undertaken. The 100 cardiopaths had 133 electrocardiographic alterations most of them in grade II of the New York Heart Association classification. 98 cardiopaths were classified in grade I by Echo-Doppler and only 2 cases were in grade III due to low ejection fraction. The difference in average parasitemia in patients of group A and B was not significant and no statistically differences were observed between average parasitemia of cardiopaths grade II versus grade I of NYHA. This results allow to characterize same clinical, electrocardiographical and parasitological features in chagasic cardiopaths of Chile.

  5. EFFECTS OF VITAMIN C SUPPLEMENTATION ON THE CHRONIC PHASE OF CHAGAS DISEASE

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    Ricardo Guimarães MARIM

    2015-06-01

    Full Text Available Introduction: In order to examine the effectiveness of vitamin C (ascorbic acid in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 104 trypomastigotes of T. cruzi QM1strain. Methods: Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS, total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle. Results: Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever. Conclusion: Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory.

  6. Soro-epidemiologia da doença de Chagas em Santa Catarina

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    BR Schlemper Jr

    1983-12-01

    Full Text Available Em Santa Catarina, o Inquérito Sorológico Nacional para doença de Chagas (CNPq-SUCAM revelou positividade de 1,3% em cerca de 74.000 amostras de soro processadas pela reação de imunofluorescência indireta em papel de filtro, com 15 municípios apresentando prevalências de 5,4% a 41,3%. Na presente investigação, em 9 dos municípios com alta prevalência, foram obtidas amostras de sangue, por punção venosa, de 222 indivíduos dos quais 140 haviam sido sorologicamente positivos e 58 negativos no Inquérito Nacional. Em 24 outros indivíduos a reação foi executada pela primeira vez. Os testes sorológicos (imunofluorescência indireta, hemaglutinação indireta, aglutinação direta com e sem 2-mercaptoetanol e fixação do complemento realizados em 3 diferentes laboratórios evidenciaram 220 soros negativos e apenas 2 positivos. Dados epidenúológicos obtidos nas áreas trabalhadas confirmaram estes resultados negativos. Os resultados discordam daqueles encontrados pelo Inquérito Sorológico Nacional e confirmam a inexistência de focos domiciliares de transmissão da doença de Chagas em Santa Catarina.

  7. Morphological and Genetic Differentiation within the Southernmost Vector of Chagas Disease: Triatoma patagonica (Hemiptera – Reduviidae)

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    Pita, Sebastián; Calleros, Lucía; Crocco, Liliana; Panzera, Yanina; Rodríguez, Claudia S.; Panzera, Francisco

    2016-01-01

    The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica. PMID:28005972

  8. Morphological and Genetic Differentiation within the Southernmost Vector of Chagas Disease: Triatoma patagonica (Hemiptera - Reduviidae).

    Science.gov (United States)

    Nattero, Julieta; Pita, Sebastián; Calleros, Lucía; Crocco, Liliana; Panzera, Yanina; Rodríguez, Claudia S; Panzera, Francisco

    2016-01-01

    The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica.

  9. [Epidemiological status of Chagas disease in the endemic area from Region II of Antofagasta].

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    Cáceres, J; Burchard, L; Bahamonde, M I; Contreras, M C; García, A; Rojas, A; Schenone, H; Lorca, M

    1999-01-01

    During 1997 a seroepidemiological study on Chagas' disease was carried out in 18 localities of three provinces (Tocopilla, El Loa and Antofagasta) of Region II (20 degrees 56'-26 degrees South Lat.; 70 degrees 38'-67 degrees West Long.), in order to assess the impact of the control program against Triatoma infestans launched in 1988, based on insecticide spraying of dwellings. By means of ELISA and an indirect hemagglutination test for Chagas' disease blood samples from 1,034 children under 10 years of age were examined, arising a 0.5% (3 cases) positivity. Test resulted positive in 2 (0.9%) children from the locality of San Pedro de Atacama and 1 (0.4%) from Calama city, all in the age group 6-10 year-old. However, none of their dwellings were found infested with T. infestants. These results indicate that the control program has a good possibility to prevent new human infections. It is advisable to continue the seroepidemiological and entomological vigilance and remark the necessity of increasing the effort in the study of transmission through other routes, to adopt or reinforce the pertinent preventive measures.

  10. Do Brazilian scientific journals promote the adherence of Chagas disease researchers to international ethical principles?

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    Malafaia, Guilherme; Guilhem, Dirce; Talvani, André

    2013-01-01

    The ethical aspects of the Brazilian publications about human Chagas disease (CD) developed between 1996 and 2010 and the policy adopted by Brazilian medical journals were analyzed. Articles were selected on the SciELO Brazil data basis, and the evaluation of ethical aspects was based on the normative contents about ethics in research involving human experimentation according to the Brazilian resolution of the National Health Council no. 196/1996. The editorial policies of the section "Instructions to authors" were analyzed. In the period of 1996-2012, 58.9% of articles involving human Chagas disease did not refer to the fulfillment of the ethical aspects concerning research with human beings. In 80% of the journals, the requirements and confirmation of the information about ethical aspects in the studies of human CD were not observed. Although a failure in this type of service is still observed, awareness has been raised in federal agencies, educational institutions/research and publishing groups to standardize the procedures and ethical requirements for the Brazilian journals, reinforcing the fulfillment of the ethical parameters, according to the resolution of NHC no. 196/1996.

  11. Genetic variants in the chemokines and chemokine receptors in Chagas disease.

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    Flórez, Oscar; Martín, Javier; González, Clara Isabel

    2012-08-01

    Clinical symptoms of Chagas' disease occur in 30% of the individuals infected with Trypanosoma cruzi and are characterised by heart inflammation and dysfunction. Chemokines and chemokine receptors control the migration of leukocytes during the inflammatory process and are involved in the modulation of Th1 or Th2 responses. To determine their influence, we investigated the possible role of CCL5/RANTES and CXCL8/IL8 chemokines, and CCR2 and CCR5 chemokines receptors cluster gene polymorphisms with the development of chagasic cardiomyopathy. Our study included 260 Chagas seropositive individuals (asymptomatic, n=130; cardiomyopathic, n=130) from an endemic area of Colombia. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and TaqMan SNP genotyping assay. We found statistically significant differences in the distribution of the CCR5 human haplogroup (HH)-A (p=0.027; OR=3.78, 95% CI=1.04-13.72). Moreover, we found that the CCR5-2733 G and CCR5-2554 T alleles are associated, respectively, with a reduced risk of susceptibility and severity to develop chagasic cardiomyopathy. No other associations were found to be significant for the other polymorphisms analysed in the CCR5, CCR2, CCL5/RANTES and CXCL8/IL8 genes. Our data suggest that the analysed chemokines and chemokine receptor genetic variants have a weak but important association with the development of chagasic cardiomyopathy in the population under study.

  12. Arylimidamide DB766, a Potential Chemotherapeutic Candidate for Chagas' Disease Treatment ▿

    Science.gov (United States)

    Batista, Denise da Gama Jaén; Batista, Marcos Meuser; Oliveira, Gabriel Melo de; Amaral, Patrícia Borges do; Lannes-Vieira, Joseli; Britto, Constança Carvalho; Junqueira, Angela; Lima, Marli Maria; Romanha, Alvaro José; Sales Junior, Policarpo Ademar; Stephens, Chad E.; Boykin, David W.; Soeiro, Maria de Nazaré Correia

    2010-01-01

    Chagas' disease, a neglected tropical illness for which current therapy is unsatisfactory, is caused by the intracellular parasite Trypanosoma cruzi. The goal of this work is to investigate the in vitro and in vivo effects of the arylimidamide (AIA) DB766 against T. cruzi. This arylimidamide exhibits strong trypanocidal activity and excellent selectivity for bloodstream trypomastigotes and intracellular amastigotes (Y strain), giving IC50s (drug concentrations that reduce 50% of the number of the treated parasites) of 60 and 25 nM, respectively. DB766 also exerts striking effects upon different parasite stocks, including those naturally resistant to benznidazole, and displays higher activity in vitro than the reference drugs. By fluorescent and transmission electron microscopy analyses, we found that this AIA localizes in DNA-enriched compartments and induces considerable damage to the mitochondria. DB766 effectively reduces the parasite load in the blood and cardiac tissue and presents efficacy similar to that of benznidazole in mouse models of T. cruzi infection employing the Y and Colombian strains, using oral and intraperitoneal doses of up to 100 mg/kg/day that were given after the establishment of parasite infection. This AIA ameliorates electrocardiographic alterations, reduces hepatic and heart lesions induced by the infection, and provides 90 to 100% protection against mortality, which is similar to that provided by benznidazole. Our data clearly show the trypanocidal efficacy of DB766, suggesting that this AIA may represent a new lead compound candidate to Chagas' disease treatment. PMID:20457822

  13. Serological survey for Chagas' disease in school children in the Rio de Janeiro State, Brazil

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    Walter B. Petana

    1976-04-01

    Full Text Available A serological survey for Chagas' disease was carried out in school children in the Rio de Janeiro State, a zone considered as non-endemic for the infection. A total of 168 schools in 20 municipalities have been visited and 13,254 blood samples were obtained. The blood eluates were screened by the indirect fluorescence test (IFT, and all positive samples were checked and confirmed in sera by the complement fixation test (CFT. AH serologically positive children were subject to a clinical scrutiny, and the houses where the children lived have been searched for triatomine bugs. Only in two municipalities, Magé and Araruama, there was a significant number of children found positive. The total number of reactive samples by IFT and CFT from 13,004 blood samples screened was 143 (1.00 per cent. No serious clinicai symptoms suggestive of Chagas' disease have been found in any of the positive children, and no triatomine bugs were discovered in the dwellings where the children lived. The overall small percentage of children with positive serology postulates that the infection is not a serious health problem in the area investigated. It is recommended, however, to carry out a more detailed study in Magé and Araruama to find the reason for the relatively high percentage of serologically positive children encountered in these two municipalities.

  14. The effect of Ageratum fastigiatum extract on Rhodnius nasutus, vector of Chagas disease

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    Bethânia A. Avelar-Freitas

    2013-04-01

    Full Text Available Control of Chagas disease is based on insecticide spraying in domiciles in order to exterminate triatomine populations. However, since the vectors differ in susceptibility to currently used insecticides, the screening of the toxic potential of Brazilian flora may identify new molecules lethal to triatomines. This study evaluated the toxicity of ethanolic extract of Ageratum fastigiatum (Gardner R.M. King & H. Rob., Asteraceae, on Rhodnius nasutus, a known vector of Chagas disease. Ethanolic extracts of the aerial parts of A. fastigiatum were prepared at 25 and 50 mg/mL concentrations, and 5 µL was applied to fifth-instar nymphs of R. nasutus (n=30. Controls included nymphs that were treated with 5 µL ethanol (n=30 or left untreated (n=30. The percentage of dead insects in each group was observed at 24, 48, 72, 96 and 120 h after application. The extracts of A. fastigiatum showed a mortality rate of about 37% and 77% after 120 h, at concentrations of 25 and 50 mg/mL, respectively. In control groups, the mortality rate remained under 7%. The extract of A. fastigiatum contains a coumarin, a molecule with recognized toxicity in insects, and which may be responsible for killing the triatomines.

  15. GPS Velocities and Structure Across the Burma Accretionary Prism and Shillong Anticline in Bangladesh

    Science.gov (United States)

    Steckler, M. S.; Akhter, S. H.; Seeber, L.; Bilham, R. G.; Kogan, M. G.; Masson, F.; Maurin, T.; Mondal, D.; Piana Agostinetti, N.; Rangin, C.; Saha, P.

    2012-12-01

    We installed a suite of 25 GPS receivers between 2003 and 2012 covering the deltaic country of Bangladesh, which lies near the junction of the Indian Shield, the Himayalan collision belt and the Indo-Burman Wedge. The crust of the Indian Shield thins southeastward in the Bengal Basin across the hinge zone of an Early Cretaceous continental margin. The thin continental and/or oceanic crust of the Bengal Basin beyond the hinge zone is overlain by the southward prograding Ganges-Brahmaputra Delta (GBD) creating a total sediment thickness of ≥16 km. This heavily-sedimented basin is being overthrust from the north by the Shillong Massif, a 2-km high basement-cored anticlinorium exposing Indian Shield, and from the east by the accretionary prism of the Indo-Burma Wedge. The soft, oblique collision of Burma with the Bengal Basin and Ganges-Brahmaputra Delta (GBD) has built a large accretionary prism that widens northwards to 250-300 km. The prism reaches as much as half way across the deep Bengal Basin. The outer folds and the thrust front are blind and buried by the rapid sedimentation of the GBD. The GPS data in Bangladesh cover the frontal region of this unusual subaerial accretionary prism, while observations from India and Myanmar provide velocities for more internal parts of the system. The convergence across this belt is oblique and partitioned. The velocity gradients across the accretionary prism indicate E-W shortening at ~13 mm/y and N-S dextral shear at ~25 mm/y. The shortening appears to be more concentrated farther west, towards the thrust front, while the shear is more distributed and does not extend to the frontal folds. How this motion is further partitioned into elastic earthquake-cycle loading and permanent inelastic deformation remains unclear. The north-dipping Dauki thrust fault raises the Shillong Massif lowers the rapidly subsiding Surma Basin foredeep. This crustal scale convergent boundary could represent the beginning of a forward jump of the

  16. Comparison of seven diagnostic tests to detect Trypanosoma cruzi infection in patients in chronic phase of Chagas disease

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    Luisa Fernanda Duarte

    2014-07-01

    Full Text Available Objective: To compare the diagnostic performance of seven methods to determine Trypanosoma cruzi infection in patients with chronic Chagas disease.Methods: Analytical study, using the case-control design, which included 205 people (patients with Chagasic cardiomyopathy, n= 100; control group, n= 105. Three enzyme linked immunosorbent assays, one indirect hemagglutination assay and one immunochromatographic test were assessed. Additionally, DNA amplification was performed via the PCR method using kinetoplast and nuclear DNA as target sequences. For the comparative analysis of diagnostic tests, the parameters used were sensitivity, specificity, positive and negative predictive values, Receiver Operator Characteristic (ROC, positive and negative likelihood ratio, as well as κ quality analysis.Results: The commercial Bioelisa Chagas test showed the highest sensitivity (98%, specificity (100%, and positive and negative predictive values; additionally it had the highest discriminatory power. Otherwise, the amplification of T. cruzi DNA in blood samples showed low values of sensitivity (kinetoplast DNA= 51%, nuclear DNA= 22%, but high values of specificity (100%, and moderate to low discriminatory ability.Conclusion: The comparative analysis among the different methods suggests that the diagnostic strategy of T. cruzi infection in patients with chronic Chagas disease can be performed using ELISA assays based on recombinant proteins and/or synthetic peptides, which show higher diagnosis performance and can confirm and exclude the diagnosis of T. cruzi infection. The molecular methods show poor performance when used in the diagnosis of patients with chronic Chagas disease.

  17. Opportunities for improved chagas disease vector control based on knowledge, attitudes and practices of communities in the yucatan peninsula, Mexico.

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    Kathryn Rosecrans

    2014-03-01

    Full Text Available BACKGROUND: Chagas disease is a vector-borne parasitic disease of major public health importance. Current prevention efforts are based on triatomine vector control to reduce transmission to humans. Success of vector control interventions depends on their acceptability and value to affected communities. We aimed to identify opportunities for and barriers to improved vector control strategies in the Yucatan peninsula, Mexico. METHODOLOGY/PRINCIPAL FINDINGS: We employed a sequence of qualitative and quantitative research methods to investigate knowledge, attitudes and practices surrounding Chagas disease, triatomines and vector control in three rural communities. Our combined data show that community members are well aware of triatomines and are knowledgeable about their habits. However, most have a limited understanding of the transmission dynamics and clinical manifestations of Chagas disease. While triatomine control is not a priority for community members, they frequently use domestic insecticide products including insecticide spray, mosquito coils and plug-in repellents. Families spend about $32 US per year on these products. Alternative methods such as yard cleaning and window screens are perceived as desirable and potentially more effective. Screens are nonetheless described as unaffordable, in spite of a cost comparable to the average annual spending on insecticide products. CONCLUSION/SIGNIFICANCE: Further education campaigns and possibly financing schemes may lead families to redirect their current vector control spending from insecticide products to window screens. Also, synergism with mosquito control efforts should be further explored to motivate community involvement and ensure sustainability of Chagas disease vector control.

  18. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries.

    Science.gov (United States)

    Moncayo, Alvaro

    2003-07-01

    Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon and the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980's as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Bras lia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in1997, in Chile in 1999, and in 8 of the 12 endemic states of Brazil in 2000 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%. Similar control multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been recorded to ensure the interruption of the transmission of Chagas disease by 2005 as requested by a Resolution of the World Health Assembly approved in 1998. The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the program is a health investment with good return. Since the inception in 1979 of the Steering Committee on Chagas Disease

  19. Longitudinal study of patients with chronic Chagas cardiomyopathy in Brazil (SaMi-Trop project): a cohort profile

    Science.gov (United States)

    Cardoso, Clareci Silva; Sabino, Ester Cerdeira; Oliveira, Claudia Di Lorenzo; de Oliveira, Lea Campos; Ferreira, Ariela Mota; Cunha-Neto, Edécio; Bierrenbach, Ana Luiza; Ferreira, João Eduardo; Haikal, Desirée Sant'Ana; Reingold, Arthur L; Ribeiro, Antonio Luiz P

    2016-01-01

    Purpose We have established a prospective cohort of 1959 patients with chronic Chagas cardiomyopathy to evaluate if a clinical prediction rule based on ECG, brain natriuretic peptide (BNP) levels, and other biomarkers can be useful in clinical practice. This paper outlines the study and baseline characteristics of the participants. Participants The study is being conducted in 21 municipalities of the northern part of Minas Gerais State in Brazil, and includes a follow-up of 2 years. The baseline evaluation included collection of sociodemographic information, social determinants of health, health-related behaviours, comorbidities, medicines in use, history of previous treatment for Chagas disease, functional class, quality of life, blood sample collection, and ECG. Patients were mostly female, aged 50–74 years, with low family income and educational level, with known Chagas disease for >10 years; 46% presented with functional class >II. Previous use of benznidazole was reported by 25.2% and permanent use of pacemaker by 6.2%. Almost half of the patients presented with high blood cholesterol and hypertension, and one-third of them had diabetes mellitus. N-terminal of the prohormone BNP (NT-ProBNP) level was >300 pg/mL in 30% of the sample. Findings to date Clinical and laboratory markers predictive of severe and progressive Chagas disease were identified as high NT-ProBNP levels, as well as symptoms of advanced heart failure. These results confirm the important residual morbidity of Chagas disease in the remote areas, thus supporting political decisions that should prioritise in addition to epidemiological surveillance the medical treatment of chronic Chagas cardiomyopathy in the coming years. The São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) represents a major challenge for focused research in neglected diseases, with knowledge that can be applied in primary healthcare. Future plans We will continue following this patients’ cohort

  20. Processing and review interface for strong motion data (PRISM) software, version 1.0.0—Methodology and automated processing

    Science.gov (United States)

    Jones, Jeanne; Kalkan, Erol; Stephens, Christopher

    2017-02-23

    A continually increasing number of high-quality digital strong-motion records from stations of the National Strong-Motion Project (NSMP) of the U.S. Geological Survey (USGS), as well as data from regional seismic networks within the United States, call for automated processing of strong-motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. In combination with the Advanced National Seismic System Quake Monitoring System (AQMS), PRISM automates the processing of strong-motion records. When used without AQMS, PRISM provides batch-processing capabilities. The PRISM version 1.0.0 is platform independent (coded in Java), open source, and does not depend on any closed-source or proprietary software. The software consists of two major components: a record processing engine and a review tool that has a graphical user interface (GUI) to manually review, edit, and process records. To facilitate use by non-NSMP earthquake engineers and scientists, PRISM (both its processing engine and review tool) is easy to install and run as a stand-alone system on common operating systems such as Linux, OS X, and Windows. PRISM was designed to be flexible and extensible in order to accommodate new processing techniques. This report provides a thorough description and examples of the record processing features supported by PRISM. All the computing features of PRISM have been thoroughly tested.

  1. Clínica e terapêutica da doença de Chagas

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    Francisco S. Laranja

    1948-06-01

    Full Text Available 1 - Baseados na experiência adquirida nos últimos cinco anos em Bambuí, Minas Gerais, onde mais de seiscentos casos de doença de Chagas tém sido estudados, os autores fazem uma revisão das manifestações clínicas desta doença. mencionam alguns dados sôbre a incidência da esquizotripanose e chamam a atenção para a importância social desta moléstia. 2 - Sugerem a seguinte sistematização das fórmas clinicas da esquizotripanose: a Forma aguda; b Formas crônicas: 1 - Forma indeterminada (cardiacos potenciais, 2 - Forma cardíaca (cardiopatia crônica. Os autores não encontraram no material estudado em Bambuí casos classificaveis como forma nervosa crônica. 3 - Apresentam evidências de ordem clínica e experimental que justificam admitir-se a cardiopatia crônica da doença de Chagas como entidade clinica definida. 4 - As manifestações da infecção aguda são estudadas à luz da experiência adquirida com os 103 casos agudos diagnosticados em Bambuí. Dois tipos de fenômenos edematosos podem ocorrer em pacientes com esquizotripanose aguda: o edema local, de porta de entrada do parasito, e o edema generalizado (o chamado "mixedema". A patogenia dêste último é revista e sugere-se que ele seja devido a uma hipoproteinemia. O edema local parece de natureza inflamatória. As manifestações da cardiopatia aguda da doença de Chagas são descritas. Ritmo de galope, aumento da area cardíaca (em alguns casos devido a transudato pericárdico, prolongamento do espaço P-R, alterações primárias da onda T e extra-sístoles ventriculares - constituem os sinais mais importantes para o diagnóstico da cardiopatia aguda. Bloqueio de ramo direito foi encontrado em três casos fatais de cardiopatia aguda, um dos quais apresentou também pronunciado desnivelamento de ST (padrão de injúria. A morte durante a infecção aguda é usualmente precedida por manifestações convulsivas. Na maioria dos casos as manifestações, da infec

  2. Lineage analysis of circulating Trypanosoma cruzi parasites and their association with clinical forms of Chagas disease in Bolivia.

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    Ramona del Puerto

    Full Text Available BACKGROUND: The causative agent of Chagas disease, Trypanosoma cruzi, is divided into 6 Discrete Typing Units (DTU: Tc I, IIa, IIb, IIc, IId and IIe. In order to assess the relative pathogenicities of different DTUs, blood samples from three different clinical groups of chronic Chagas disease patients (indeterminate, cardiac, megacolon from Bolivia were analyzed for their circulating parasites lineages using minicircle kinetoplast DNA polymorphism. METHODS AND FINDINGS: Between 2000 and 2007, patients sent to the Centro Nacional de Enfermedades Tropicales for diagnosis of Chagas from clinics and hospitals in Santa Cruz, Bolivia, were assessed by serology, cardiology and gastro-intestinal examinations. Additionally, patients who underwent colonectomies due to Chagasic magacolon at the Hospital Universitario Japonés were also included. A total of 306 chronic Chagas patients were defined by their clinical types (81 with cardiopathy, 150 without cardiopathy, 100 with megacolon, 144 without megacolon, 164 with cardiopathy or megacolon, 73 indeterminate and 17 cases with both cardiopathy and megacolon. DNA was extracted from 10 ml of peripheral venous blood for PCR analysis. The kinetoplast minicircle DNA (kDNA was amplified from 196 out of 306 samples (64.1%, of which 104 (53.3% were Tc IId, 4 (2.0% Tc I, 7 (3.6% Tc IIb, 1 (0.5% Tc IIe, 26 (13.3% Tc I/IId, 1 (0.5% Tc I/IIb/IId, 2 (1.0% Tc IIb/d and 51 (25.9% were unidentified. Of the 133 Tc IId samples, three different kDNA hypervariable region patterns were detected; Mn (49.6%, TPK like (48.9% and Bug-like (1.5%. There was no significant association between Tc types and clinical manifestations of disease. CONCLUSIONS: None of the identified lineages or sublineages was significantly associated with any particular clinical manifestations in the chronic Chagas patients in Bolivia.

  3. Characterization of an immunodominant antigenic epitope from Trypanosoma cruzi as a biomarker of chronic Chagas' disease pathology.

    Science.gov (United States)

    Thomas, M Carmen; Fernández-Villegas, Ana; Carrilero, Bartolomé; Marañón, Concepción; Saura, Daniel; Noya, Oscar; Segovia, Manuel; Alarcón de Noya, Belkisyolé; Alonso, Carlos; López, Manuel Carlos

    2012-02-01

    Nowadays, the techniques available for chronic Chagas' disease diagnosis are very sensitive; however, they do not allow discrimination of the patient's clinical stages of the disease. The present paper describes that three out of the five different repeats contained in the Trypanosoma cruzi TcCA-2 membrane protein (3972-FGQAAAGDKPPP, 6303-FGQAAAGDKPAP, and 3973-FGQAAAGDKPSL) are recognized with high sensitivity (>90%) by sera from chronic Chagas' disease patients and that they are not recognized by sera from patients in the acute phase of the disease. A total of 133 serum samples from chagasic patients and 50 serum samples from healthy donors were tested. In addition, sera from 15 patients with different autoimmune diseases, 43 serum samples from patients suffering an infectious disease other than Chagas' disease, and 38 serum samples from patients with nonchagasic cardiac disorders were also included in this study. The residue 3973 peptide shows a specificity of >98%, as it is not recognized by individuals with autoimmune and inflammatory processes or by patients with a nonchagasic cardiomyopathy. Remarkably, the levels of antibody against the 3973 epitope detected by the sera from Chagas' disease patients in the symptomatic chronic phase, involving cardiac or digestive alterations, are higher than those detected by the sera from Chagas' disease patients in the indeterminate phase of the disease. It is suggested that the diagnostic technique described could also be used to indicate the degree of pathology. The amino acids F, Q, and DKP located in the peptide at positions 1, 3, and 8 to 10, respectively, are essential to conform to the immunodominant antigenic epitope.

  4. Polymorphic sites at the immunoregulatory CTLA-4 gene are associated with chronic chagas disease and its clinical manifestations.

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    Fabrício C Dias

    Full Text Available BACKGROUND: Chagas disease affects approximately 10 million people mainly in Latin America. The immune regulation by the host seems to be an essential factor for disease evolution, and immune system inhibitory molecules such as CTLA-4 and PD-1 favor the maintenance of peripheral tolerance. Considering that polymorphisms at the immunoregulatory CTLA-4 and PDCD1 genes may alter their inhibitory function, we investigated the association of alleles, genotypes and haplotypes of polymorphic sites observed at the CTLA-4 and PDCD1 genes with different clinical manifestations of chronic Chagas disease (indeterminate, cardiac, digestive and mixed. METHODS: The polymorphisms at the CTLA-4 (-1722T/C, -318C/T and +49A/G and PDCD1 (PD-1.3G/A genes were typed using TaqMan methodology in 277 chronic Chagas disease patients classified into four groups, according to clinical characteristics, and 326 non-infected controls. RESULTS: Our results showed that CTLA-4 -1722CC genotype (22%, -1722C allele (27% and CTLA-4 TCG (8.6%, TCA (26% and CCA (15% haplotypes were strongly associated with the indeterminate form, while the CTLA-4-318CT genotype (82% and CTLA-4-318T allele (47% were found mainly in patients with the mixed form of the disease. The CTLA-4 TCG haplotype (10.2% was associated with the digestive form. On the other hand, the PD-1.3G/A polymorphism was not associated with chronic Chagas disease and its clinical manifestations. CONCLUSIONS: Here, we showed that alleles, genotypes and haplotypes reported to increase the expression of the regulatory molecule CTLA-4 were associated with the indeterminate form of the disease. Taken together, our data support the idea that polymorphic sites at immunoregulatory genes may influence the development of Chagas disease variants.

  5. Lineage Analysis of Circulating Trypanosoma cruzi Parasites and Their Association with Clinical Forms of Chagas Disease in Bolivia

    Science.gov (United States)

    del Puerto, Ramona; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Iihoshi, Naomi; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Gutierrez Velarde, Freddy Udalrico; Renjel, Luis Alberto; Miura, Sachio; Higo, Hiroo; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

    2010-01-01

    Background The causative agent of Chagas disease, Trypanosoma cruzi, is divided into 6 Discrete Typing Units (DTU): Tc I, IIa, IIb, IIc, IId and IIe. In order to assess the relative pathogenicities of different DTUs, blood samples from three different clinical groups of chronic Chagas disease patients (indeterminate, cardiac, megacolon) from Bolivia were analyzed for their circulating parasites lineages using minicircle kinetoplast DNA polymorphism. Methods and Findings Between 2000 and 2007, patients sent to the Centro Nacional de Enfermedades Tropicales for diagnosis of Chagas from clinics and hospitals in Santa Cruz, Bolivia, were assessed by serology, cardiology and gastro-intestinal examinations. Additionally, patients who underwent colonectomies due to Chagasic magacolon at the Hospital Universitario Japonés were also included. A total of 306 chronic Chagas patients were defined by their clinical types (81 with cardiopathy, 150 without cardiopathy, 100 with megacolon, 144 without megacolon, 164 with cardiopathy or megacolon, 73 indeterminate and 17 cases with both cardiopathy and megacolon). DNA was extracted from 10 ml of peripheral venous blood for PCR analysis. The kinetoplast minicircle DNA (kDNA) was amplified from 196 out of 306 samples (64.1%), of which 104 (53.3%) were Tc IId, 4 (2.0%) Tc I, 7 (3.6%) Tc IIb, 1 (0.5%) Tc IIe, 26 (13.3%) Tc I/IId, 1 (0.5%) Tc I/IIb/IId, 2 (1.0%) Tc IIb/d and 51 (25.9%) were unidentified. Of the 133 Tc IId samples, three different kDNA hypervariable region patterns were detected; Mn (49.6%), TPK like (48.9%) and Bug-like (1.5%). There was no significant association between Tc types and clinical manifestations of disease. Conclusions None of the identified lineages or sublineages was significantly associated with any particular clinical manifestations in the chronic Chagas patients in Bolivia. PMID:20502516

  6. Histological and endoscopic features of the stomachs of patients with Chagas disease in the era of Helicobacter pylori

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    Fernanda Machado Fonseca

    2014-12-01

    Full Text Available Introduction Most studies that have evaluated the stomachs of patients with Chagas disease were performed before the discovery of Helicobacter pylori and used no control groups. This study compared the gastric features of chagasic and non-chagasic patients and assessed whether gastritis could be associated with Chagas disease. Methods Gastric biopsy samples were taken from patients who underwent endoscopy for histological analysis according to the Updated Sydney System. H. pylori infection was assessed by histology, 16S ribosomal ribonucleic acid (rRNA polymerase chain reaction (PCR, serology and the 13C-urea breath test. Patients were considered H. pylori-negative when all of these diagnostic tests were negative. Clinical and socio-demographic data were obtained by reviewing medical records and using a questionnaire. Results The prevalence of H. pylori infection (70.3% versus 71.7% and chronic gastritis (92.2% versus 85% was similar in the chagasic and non-chagasic groups, respectively; such as peptic ulcer, atrophy and intestinal metaplasia. Gastritis was associated with H. pylori infection independent of Chagas disease in a log-binomial regression model. However, the chagasic H. pylori-negative patients showed a significantly higher grade of mononuclear (in the corpus and polymorphonuclear (PMN (in the antrum cell infiltration. Additionally, the patients with the digestive form of Chagas disease showed a significantly lower prevalence of corpus atrophy than those with other clinical forms. Conclusions The prevalence of H. pylori infection and of gastric histological and endoscopic features was similar among the chagasic and non-chagasic patients. Additionally, this is the first controlled study to demonstrate that H. pylori is the major cause of gastritis in patients with Chagas disease.

  7. Chagas cardiomyopathy: the potential of diastolic dysfunction and brain natriuretic peptide in the early identification of cardiac damage.

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    Ana Garcia-Alvarez

    Full Text Available INTRODUCTION: Chagas disease remains a major cause of mortality in several countries of Latin America and has become a potential public health problem in non-endemic countries as a result of migration flows. Cardiac involvement represents the main cause of mortality, but its diagnosis is still based on nonspecific criteria with poor sensitivity. Early identification of patients with cardiac involvement is desirable, since early treatment may improve prognosis. This study aimed to assess the role of diastolic dysfunction, abnormal myocardial strain and elevated brain natriuretic peptide (BNP in the early identification of cardiac involvement in Chagas disease. METHODOLOGY/PRINCIPAL FINDINGS: Fifty-four patients divided into 3 groups--group 1 (undetermined form: positive serology without ECG or 2D-echocardiographic abnormalities; N = 32, group 2 (typical ECG abnormalities of Chagas disease but normal 2D-echocardiography; N = 14, and group 3 (regional wall motion abnormalities, left ventricular [LV] end-diastolic diameter >55 mm or LV ejection fraction 37 pg/ml were noted in 0%, 13%, 29% and 63% in controls and groups 1 to 3, respectively. Half of patients in the undetermined form had impaired relaxation patterns, whereas half of patients with ECG abnormalities suggestive of Chagas cardiomyopathy had normal diastolic function. In group 1, BNP levels were statistically higher in patients with diastolic dysfunction as compared to those with normal diastolic function (27 ± 26 vs. 11 ± 8 pg/ml, p = 0.03. CONCLUSION/SIGNIFICANCE: In conclusion, the combination of diastolic function and BNP measurement adds important information that could help to better stratify patients with Chagas disease.

  8. Evidence of a Biological Control over Origin, Growth and End of the Calcite Prisms in the Shells of Pinctada margaritifera (Pelecypod, Pterioidea

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    Jean-Pierre Cuif

    2014-12-01

    Full Text Available Consistently classified among the references for calcite simple prisms, the microstructural units that form the outer layer of the Pinctada margaritifera have been investigated through a series of morphological, crystallographical and biochemical characterizations. It is often said that the polygonal transverse shape of the prisms result from the competition for space between adjacent crystals. In contrast to this classical scheme the Pinctada prisms appear to be composed of four successive developmental stages from the concentrically growing disks on the internal side of the periostracum to the morphological, structural and compositional changes in both envelopes and mineral components at the end of the prisms. These latest structural and compositional changes predate nacre deposition, so that the end of prism growth is not caused by occurrence of nacre, but by metabolic changes in the secretory epithelium. This sequence makes obvious the permanent biological control exerted by the outer cell layer of the mantle in both organic envelopes and mineralizing organic phases.

  9. Cardiac beta-receptors in experimental Chagas' disease Receptores beta cardíacos na doença de Chagas experimental

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    Julio E. Enders

    1995-02-01

    Full Text Available Experimental Chagas' disease (45 to 90 days post-infection showed serious cardiac alterations in the contractility and in the pharmacological response to beta adrenergic receptors in normal and T. cruzi infected mice (post-acute phase. Chagasic infection did not change the beta receptors density (78.591 ± 3.125 fmol/mg protein and 73.647 ± 2.194 fmol/mg protein for controls but their affinity was significantly diminished (Kd = 7.299 ± 0.426 nM and Kd = 3.759 ± 0.212 nM for the control p Estudaram-se os receptores beta cardíacos de camundongos infectados pelo Trypanosoma cruzi na fase pós-aguda da doença de Chagas para estabelecer em que medida os mesmos contribuem a gerar respostas anômalas às catecolaminas observadas nestes miocardios. Utilizara-se 3-H/DHA para a marcação dos receptores beta cardíacos dos camundongos normais e dos infectados na fase pós-aguda (45 a 90 dias pós-infecção. O número dos sítios de fixação foi similar nos dois grupos, 78.591 ± 3.125 fmol/mg. Proteína nos chagásicos e 73.647 ± 2.194 fmol/mg. Proteína no grupo controle. Em vez disso, a afinidade verificou-se significativamente diminuida no grupo chagásico (Kd = 7.299 ± 0.426 nM respeito do controle (Kd = 3.759 ± 0.212 nM p < 0.001. Os resultados obtidos demonstram que as modificações observadas na estimulação adrenérgica do miocárdio chagásico se correlacionam com a menor afinidade dos receptores beta cardíacos e que estas alterações exerceriam uma parte determinante para as consequências funcionais que são detectadas na fase crônica.

  10. Contribuciones de la genética y la proteómica al estudio de la enfermedad de Chagas Genomic and proteomic contributions for Chagas disease control

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    Teresa López-Ordóñez

    2009-01-01

    Full Text Available La enfermedad de Chagas representa uno de los problemas más importantes de salud pública en el continente americano. El conocimiento sobre el genoma y el proteoma de los agentes de esta infección es esencial para desarrollar herramientas precisas y eficaces a corto y largo plazo y prevenir la transmisión. En el presente documento se destacan los aportes que han permitido mejorar el diseño, la implementación y la eficacia de las actividades de vigilancia y control de la enfermedad. Se revisan la contribución de la información genómica o proteómica sobre la distribución geográfica de los vectores, y la diversidad y la dinámica poblacional, además de la identificación de poblaciones y especies blanco para control. Por otra parte, se analiza la forma en que el conocimiento del genoma del parásito ha contribuido al diagnóstico de la infección, el estudio de las poblaciones de Trypanosoma cruzi, el tratamiento farmacológico y la interacción del parásito con sus hospederos. Una revisión de estas contribuciones incluye los temas de investigación básica y aplicada más destacados para el futuro inmediato.Chagas disease represents one of the more significant public health problems in the Americas. Information regarding the genome and proteome of vectors and parasite, as well as their interactions, will be essential to develop specific and effective diagnostic and preventive tools. Advances that have contributed to the design, implementation, and efficacy of disease surveillance and control activities are reviewed. Genomic and proteomic information has contributed to a better understanding of vector distributions and dispersion, diversity, population dynamics, and control targets (populations and species. In addition, genomic and proteomic studies have impacted parasite diagnostics, Trypanosoma cruzi population dynamics, pharmacological treatment and knowledge of parasite-host interactions. Discussion of these contributions includes

  11. Determinação do peptídeo natriurético cerebral humano em portadores da doença de Chagas Measurement of human brain natriuretic peptide in patients with Chagas' disease

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    Railton Bezerra de Melo

    2005-02-01

    Full Text Available OBJETIVO: Determinar os níveis séricos do peptídeo natriurético cerebral (PNB em pacientes com cardiopatia chagásica crônica e em indivíduos com sorologia positiva para doença de Chagas sem comprometimento cardíaco, e correlacionar os níveis de PNB com o grau de comprometimento cardíaco, dimensões cardíacas, presença de marcapasso e fração de ejeção. MÉTODOS: Concentrações séricas de PNB foram determinadas através do Triage® - BNP Test, produzido pela BIOSITE®. Foi avaliado o PNB sérico de 25 indivíduos do ambulatório de doença de Chagas do Hospital Universitário Oswaldo Cruz, distribuídos em 2 grupos, um, G1; composto por 13 portadores de sorologia positiva para doença de Chagas, assintomáticos e sem cardiopatia detectável pelo eletrocardiograma, radiografia do tórax e ecocardiograma, o outro, G2; por 12 portadores da doença de Chagas com comprometimento cardíaco. RESULTADOS: Níveis significativamente mais elevados de PNB foram detectados nos pacientes chagásicos com comprometimento cardíaco: (G1=4,4±4,4 pg/ml, G2=293,0±460,2 pg/ml pOBJECTIVE: To measure the serum levels of brain natriuretic peptide (BNP in patients with chronic chagasic heart disease and in individuals with positive serology for Chagas' disease and no heart impairment, and to correlate the serum BNP levels with the degree of cardiac impairment, cardiac dimensions, presence of a pacemaker, and ejection fraction. METHODS: Serum BNP concentrations were determined by use of the Triage - BNP Test produced by BIOSITE. Serum BNP was assessed in 25 patients from the Chagas' disease outpatient clinic of the Hospital Universitário Oswaldo Cruz, who were divided into 2 groups as follows: 1 G1 - comprising 13 assymptomatic patients with positive serology for Chagas' disease and no heart disease detectable on electrocardiography, chest X-ray, and echocardiography; and 2 G2 - comprising 12 patients with Chagas' disease and heart impairment. RESULTS

  12. Abbot Close Nursing Home, St. Marys Terrace, Askeaton, Limerick.

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Background Cell surface pili in Gram positive bacteria have been reported to orchestrate the colonization of host tissues, evasion of immunity and the development of biofilms. So far, little if any information is available on the presence of pilus-like structures in human gut commensals like bifidobacteria. Results and discussion In this report, Atomic Force Microscopy (AFM) of various bifidobacterial strains belonging to Bifidobacterium bifidum, Bifidobacterium longum subsp. longum, Bifidobacterium dentium, Bifidobacterium adolescentis and Bifidobacterium animalis subsp. lactis revealed the existence of appendages resembling pilus-like structures. Interestingly, these microorganisms harbour two to six predicted pilus gene clusters in their genome, with each organized in an operon encompassing the major pilin subunit-encoding gene (designated fimA or fimP) together with one or two minor pilin subunit-encoding genes (designated as fimB and\\/or fimQ), and a gene encoding a sortase enzyme (strA). Quantitative Real Time (qRT)-PCR analysis and RT-PCR experiments revealed a polycistronic mRNA, encompassing the fimA\\/P and fimB\\/Q genes, which are differentially expressed upon cultivation of bifidobacteria on various glycans.

  13. [Abbot Vision. An interesting laboratory instrument for small hospitals].

    Science.gov (United States)

    Landaas, S; Maehlum, S; Sjøkvist, R

    1991-06-20

    Abbott Vision is a technologically advanced chemistry analyzer developed for decentralized testing. About 30 different tests can be performed using disposable test packs containing wet reagents. The instrument was evaluated in a smaller hospital and (except for potassium) good results were obtained with respect to precision and conformity with results from a referral laboratory. The analyzer is considered to be of special advantage in cases of emergency and when there is no laboratory technician on duty. The cost per analysis is much higher, however, than with conventional techniques.

  14. Regional Variation of CH4 and N2 Production Processes in the Deep Aquifers of an Accretionary Prism

    Science.gov (United States)

    Matsushita, Makoto; Ishikawa, Shugo; Nagai, Kazushige; Hirata, Yuichiro; Ozawa, Kunio; Mitsunobu, Satoshi; Kimura, Hiroyuki

    2016-01-01

    Accretionary prisms are mainly composed of ancient marine sediment scraped from the subducting oceanic plate at a convergent plate boundary. Large amounts of anaerobic groundwater and natural gas, mainly methane (CH4) and nitrogen gas (N2), are present in the deep aquifers associated with an accretionary prism; however, the origins of these gases are poorly understood. We herein revealed regional variations in CH4 and N2 production processes in deep aquifers in the accretionary prism in Southwest Japan, known as the Shimanto Belt. Stable carbon isotopic and microbiological analyses suggested that CH4 is produced through the non-biological thermal decomposition of organic matter in the deep aquifers in the coastal area near the convergent plate boundary, whereas a syntrophic consortium of hydrogen (H2)-producing fermentative bacteria and H2-utilizing methanogens contributes to the significant production of CH4 observed in deep aquifers in midland and mountainous areas associated with the accretionary prism. Our results also demonstrated that N2 production through the anaerobic oxidation of organic matter by denitrifying bacteria is particularly prevalent in deep aquifers in mountainous areas in which groundwater is affected by rainfall. PMID:27592518

  15. Goos-Hänchen shifts at a resonance angle of a two-prism structure using COMSOL multiphysics

    Science.gov (United States)

    Zhang, Wenjing; Zhang, Zhiwei; Yang, Peng; Zhu, Xiang; Dai, Yifan

    2016-10-01

    We simulated and analyzed Goos-Hänchen (GH) shifts of 633 nm polarized light through a two-prism structure, consisting of a right triangle prism and an isosceles triangle prism with Kretschmann-Raether configuration, by comparing the results from COMSOL Multiphysics (CM) simulation software with that of a stationary-phase analysis (SPA). For this two-prism structure, using a gold film that of thickness 45 nm, the maximum positive GH shift, obtained using SPA at the resonance angle of 44.1°, was 354 μm. Using CM at an incident angle of 43.8°, we found the maximum positive GH shift of 9.45 μm. The results obtained using CM are in agreement with those obtained by the SPA around the resonance angle, although the enhancement effect from CM is much less than that of SPA. This is because SPA depends on the differentiation of the phase shift with respect to the incident angle, while a drastic phase shift occurs at the resonance angle. These results are useful for designing high-sensitivity SPR sensors based on GH shift measurement and for application in waveguide-type SPR devices, with sizes in the order of micro millimeter.

  16. Differential subsidence within a coastal prism : late-Glacial - Holocene tectonics In The Rhine-Meuse delta, the Netherlands

    NARCIS (Netherlands)

    Cohen, K.M.

    2003-01-01

    The Rhine-Meuse river system has been studied extensively over the past few decades. The Netherlands' coastal prism formed in response to Holocene sea level rise and buried the Weichselian (OIS-2) Rhine-Meuse valley. Although the geological-geomorphological evolution of the Rhine-Meuse system since

  17. A Pilot Evaluation of On-Road Detection Performance by Drivers with Hemianopia Using Oblique Peripheral Prisms

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    Alex R. Bowers

    2012-01-01

    Full Text Available Aims. Homonymous hemianopia (HH, a severe visual consequence of stroke, causes difficulties in detecting obstacles on the nonseeing (blind side. We conducted a pilot study to evaluate the effects of oblique peripheral prisms, a novel development in optical treatments for HH, on detection of unexpected hazards when driving. Methods. Twelve people with complete HH (median 49 years, range 29–68 completed road tests with sham oblique prism glasses (SP and real oblique prism glasses (RP. A masked evaluator rated driving performance along the 25 km routes on busy streets in Ghent, Belgium. Results. The proportion of satisfactory responses to unexpected hazards on the blind side was higher in the RP than the SP drive (80% versus 30%; P=0.001, but similar for unexpected hazards on the seeing side. Conclusions. These pilot data suggest that oblique peripheral prisms may improve responses of people with HH to blindside hazards when driving and provide the basis for a future, larger-sample clinical trial. Testing responses to unexpected hazards in areas of heavy vehicle and pedestrian traffic appears promising as a real-world outcome measure for future evaluations of HH rehabilitation interventions aimed at improving detection when driving.

  18. A field trial of alternative targeted screening strategies for Chagas disease in Arequipa, Peru.

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    Gabrielle C Hunter

    2012-01-01

    Full Text Available BACKGROUND: Chagas disease is endemic in the rural areas of southern Peru and a growing urban problem in the regional capital of Arequipa, population ∼860,000. It is unclear how to implement cost-effective screening programs across a large urban and periurban environment. METHODS: We compared four alternative screening strategies in 18 periurban communities, testing individuals in houses with 1 infected vectors; 2 high vector densities; 3 low vector densities; and 4 no vectors. Vector data were obtained from routine Ministry of Health insecticide application campaigns. We performed ring case detection (radius of 15 m around seropositive individuals, and collected data on costs of implementation for each strategy. RESULTS: Infection was detected in 21 of 923 (2.28% participants. Cases had lived more time on average in rural places than non-cases (7.20 years versus 3.31 years, respectively. Significant risk factors on univariate logistic regression for infection were age (OR 1.02; p = 0.041, time lived in a rural location (OR 1.04; p = 0.022, and time lived in an infested area (OR 1.04; p = 0.008. No multivariate model with these variables fit the data better than a simple model including only the time lived in an area with triatomine bugs. There was no significant difference in prevalence across the screening strategies; however a self-assessment of disease risk may have biased participation, inflating prevalence among residents of houses where no infestation was detected. Testing houses with infected-vectors was least expensive. Ring case detection yielded four secondary cases in only one community, possibly due to vector-borne transmission in this community, apparently absent in the others. CONCLUSIONS: Targeted screening for urban Chagas disease is promising in areas with ongoing vector-borne transmission; however, these pockets of epidemic transmission remain difficult to detect a priori. The flexibility to adapt to the

  19. Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

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    Durvasula Ravi V

    2011-05-01

    Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

  20. Chagas disease in an area of recent occupation in Cochabamba, Bolivia

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    Albarracin-Veizaga Hugo

    1999-01-01

    Full Text Available INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000, where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males selected by systematic sampling. Concerning each subject age, gender, birthplace, occupation, duration of residence and building materials used in their houses were recorded. Vectors were captured both in domestic and peridomestic environments. RESULTS: Seropositive, 12.5% (16/128: females, 15.1% (11/73; males, 9.1% (5/55. Average time of residence: 6.1 years for the whole population sample and 7.4 years for the seropositive subjects. Most houses had adobe walls (76.7% , n= 30, galvanized iron rooves (86.7% and earthen floors (53.4% 80% of the walls had crevices. One hundred forty seven specimens of Triatoma infestans were captured, of which 104 (70.7% were domestic, and 1 peridomestic Triatoma sordida. Precipitin host identification: birds, 67.5%; humans, 27.8%; rodents, 11.9%; dogs, 8.7%; cats, 1.6%. House infestation and density indices were 53.3 and 493.0 respectively. We found 21 (14.3% specimens of T. infestans infected with trypanosomes, 18 (85.7% of which in domestic environments. DISCUSSION: The elements for the vector transmission of Chagas disease are present in Avaroa/Primer de Mayo and the ancient custom of keeping guinea pigs indoors adds to the risk of human infection. In neighboring Cochabamba, due to substandard quality control, contaminated blood transfusions are not infrequent, which further aggravates the spread of Chagas disease. Prompt action to check the transmission of this infection, involving additionally the congenital and transfusional

  1. Antigenicity and diagnostic potential of vaccine candidates in human Chagas disease.

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    Shivali Gupta

    Full Text Available BACKGROUND: Chagas disease, caused by Trypanosoma cruzi, is endemic in Latin America and an emerging infectious disease in the US and Europe. We have shown TcG1, TcG2, and TcG4 antigens elicit protective immunity to T. cruzi in mice and dogs. Herein, we investigated antigenicity of the recombinant proteins in humans to determine their potential utility for the development of next generation diagnostics for screening of T. cruzi infection and Chagas disease. METHODS AND RESULTS: Sera samples from inhabitants of the endemic areas of Argentina-Bolivia and Mexico-Guatemala were analyzed in 1(st-phase for anti-T. cruzi antibody response by traditional serology tests; and in 2(nd-phase for antibody response to the recombinant antigens (individually or mixed by an ELISA. We noted similar antibody response to candidate antigens in sera samples from inhabitants of Argentina and Mexico (n=175. The IgG antibodies to TcG1, TcG2, and TcG4 (individually and TcG(mix were present in 62-71%, 65-78% and 72-82%, and 89-93% of the subjects, respectively, identified to be seropositive by traditional serology. Recombinant TcG1- (93.6%, TcG2- (96%, TcG4- (94.6% and TcG(mix- (98% based ELISA exhibited significantly higher specificity compared to that noted for T. cruzi trypomastigote-based ELISA (77.8% in diagnosing T. cruzi-infection and avoiding cross-reactivity to Leishmania spp. No significant correlation was noted in the sera levels of antibody response and clinical severity of Chagas disease in seropositive subjects. CONCLUSIONS: Three candidate antigens were recognized by antibody response in chagasic patients from two distinct study sites and expressed in diverse strains of the circulating parasites. A multiplex ELISA detecting antibody response to three antigens was highly sensitive and specific in diagnosing T. cruzi infection in humans, suggesting that a diagnostic kit based on TcG1, TcG2 and TcG4 recombinant proteins will be useful in diverse situations.

  2. Urbanización de la enfermedad de Chagas: Encuesta SOSPEECHA

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    Guillermo M. Marconcini

    2008-01-01

    Full Text Available IntroducciónLas grandes corrientes migratorias que han poblado la Capital Federal y la provincia de Buenos Aires durante los últimos 30 años fueron alterando el patrón habitual de transmisión vectorial de las áreas endémicas para constituir el cuarto ciclo o urbanización de la enfermedad de Chagas. En respuesta a estos cambios, los esfuerzos deben centrarse en el paciente chagásico; de este modo, la prevención del susceptible surge como una estrategia adecuada en áreas no endémicas.ObjetivosObtener información de la situación epidemiológica de la enfermedad de Chagas en región no endémica a partir de una encuesta escolar y estimar su prevalencia.Material y métodosSe encuestaron ocho escuelas públicas, de mayo a octubre de 2006. El procedimiento estadístico fue descriptivo, con indicación de frecuencia y porcentajes; la significación estadística se determinó con la prueba de chi cuadrado. Se consideró de significación estadística un valor de p < 0,001.ResultadosSe obtuvieron datos de 1.293 alumnos y su grupo familiar. El 84,9% (alumnos nacieron en la provincia de Buenos Aires. El 43,8% (madres son nativas de provincias endémicas y el 9,8% provienen de países endémicos. La prevalencia de acuerdo con la encuesta fue del 13,8%. ConclusionesLa encuesta confirmó el impacto epidemiológico de la enfermedad de Chagas en la región. La discrepancia con otros índices sugiere que cada región se debe evaluar en forma individual, ya que responden a la multicausalidad de los factores que intervienen.

  3. [Experience of targeted screening of Chagas disease in Ile-de-France].

    Science.gov (United States)

    Lescure, F-X; Paris, L; Elghouzzi, M H; Le Loup, G; Develoux, M; Touafek, F; Mazier, D; Pialoux, G

    2009-12-01

    2009 is marked by the centenary of the discovery by Carlos Chagas of Human American Trypanosomiasis. As a result of international cooperation its incidence has been falling in endemic areas, whereas North America and Europe are witnessing an increase in the number of imported cases. In metropolitan France, 18 such cases were reported between 2004 and 2007. Recently, estimates based on immigration figures have been made and suggest that about 1,500 imported cases can be expected in France. The object of this article is to assess the value of targeted screening of an at-risk population, originally from Latin America and now living in the Ile-de-France (area centred on Paris). The serological techniques employed were indirect immunofluorescence (IIF) and, depending on the case, 2 or 3 Elisa tests (Biomérieux, Biokit and Wiener). Trypanosoma cruzi serology was considered positive when the IIF was superior or equal to 200, or when two Elisa's were > 1, or when the IIF was superior or equal to 100 with at least one Elisa > 1. PCR was performed in 48 cases, which were considered to be positive. The tests were carried out on a voluntary basis after a publicity campaign within the Latin American community in the Ile-de-France. In this article, we present the findings of the first year of screening. Two hundred and fifty-four individuals were screened for Chagas' disease between June 2008 and June 2009. The median age was 33 years [11-63], the male/female ratio 102/152. Overall prevalence of positive serology was 23.6% (60/254). For six patients, the results were classified as "uncertain" (discordant serological tests). Of the seropositive group, 87.4% were Bolivian and 100% presented as a chronic form. Of these, 23.6% presented with functional cardiac manifestations and 22% with gastro-intestinal problems. The PCR was positive in 61% of the seropositive individuals. Clinical evaluation together with other investigations and therapeutic intervention is being carried out at

  4. Cintilografia para detecção de comprometimento miocárdico na forma indeterminada da doença de Chagas Gammagrafía para detección de compromiso miocárdico en la forma indeterminada de la enfermedad de Chagas Scintigraphy for the detection of myocardial damage in the indeterminate form of Chagas disease

    Directory of Open Access Journals (Sweden)

    Ivana Moura Abuhid

    2010-07-01

    Full Text Available FUNDAMENTO: Métodos cardiológicos não invasivos têm sido utilizados na identificação de comprometimento miocárdico na doença de Chagas. OBJETIVO: Verificar se a cintilografia miocárdica de perfusão em repouso e esforço é capaz de identificar comprometimento miocárdico precoce na forma indeterminada da doença de Chagas. MÉTODOS: Dezoito pacientes portadores da forma indeterminada da doença de Chagas e igual número de controles normais, pareados pelo sexo e idade, foram submetidos a cintilografia miocárdica de repouso e esforço com sestamibi-99mTc com o objetivo de detectar lesões cardíacas precoces. RESULTADOS: Os resultados não mostraram defeitos de perfusão ou da função ventricular nos pacientes na fase indeterminada da doença de Chagas e nos controles normais, exceto em um paciente que apresentou sinais de disfunção ventricular na análise funcional na cintilografia miocárdica de perfusão sincronizada com o eletrocardiograma (ECG. CONCLUSÃO: Os resultados deste estudo, em que pese o pequeno número de pacientes, mostraram que a cintilografia miocárdica de repouso e esforço com sestamibi-99mTc não é um método eficaz para detectar precocemente alterações miocárdicas na forma indeterminada da doença de Chagas.FUNDAMENTO: Métodos cardiológicos no invasivos han sido utilizados en la identificación de compromiso miocárdico en la Enfermedad de Chagas. OBJETIVO: Verificar si la gammagrafía miocárdica de perfusión en reposo y esfuerzo es capaz de identificar compromiso miocárdico precoz en la forma indeterminada de la Enfermedad de Chagas. MÉTODOS: Dieciocho pacientes portadores de la forma indeterminada del Mal de Chagas e igual número de controles normales, apareados por sexo y edad, fueron sometidos a gammagrafía miocárdica de reposo y esfuerzo con sestamibi-99mTc con el objetivo de detectar lesiones cardíacas precoces. RESULTADOS: Los resultados no mostraron defectos de perfusión o de la funci

  5. [Transfusional Chagas infection detected in the program for the control of Chagas disease in the state of São Paulo (Brazil)].

    Science.gov (United States)

    Wanderley, D M; de Carvalho, M E; Mantegazza, E; Yasumaru, S; Barata, L C

    1992-06-01

    A system of surveillance for Chagas' disease aiming at a systematic investigation of the occurrence of triatominae in human dwellings in S. Paulo, Brazil was proposed. It included a serological survey of residents in house considered to be potential breeding places for blood-sucking triatomines. Serologically positive cases were observed to be distributed in age groups from 19 years of age upwards. Case-investigation revealed that the infection had been acquired either in S. Paulo in the past or recently in other States. A serologically positive (titre = 128 - IgG) case of an 8-year-old male child, was detected by the In direct Fluorescent Antibody Technique (IFAT). In S. Paulo State natural transmission is now of low probability. An epidemiological investigation disclosed the fact that this was a case of blood transfusion infection. The donor was found to be serologically positive (IFAT, titre = 1024 - IgG). His case-history was typical of vector transmitted infection. It is worthy of note that blood had been donated by this patient in four instances, without his condition having been diagnosed. The necessity of organizing an integrated Public Health Service to take more efficient care of such cases is stressed.

  6. Pneumonia lipoídica associada à forma digestiva da doença de Chagas Digestive Chagas disease with concomitant lipoid pneumonia

    Directory of Open Access Journals (Sweden)

    Marcelo Fernando Ranzani

    2004-10-01

    Full Text Available Mulher de 50 anos com megaesôfago e megacólon chagásico apresentou quadro clínico de tosse seca, dor torácica e dispnéia leves. O raio X de tórax mostrou opacidade do tipo alveolar bilateral sugestivo de pneumonia. Após biópsia a céu aberto chegou-se ao diagnóstico de pneumonia lipoídica. A doença foi causada pelo uso crônico de laxantes à base de óleo mineral, utilizados nos últimos três anos. Os autores discutem a associação da forma digestiva da doença de Chagas com pneumonia lipoídica, e apresentam recomendações sobre o uso de produtos que contenham óleo mineral.A 50-year-old woman with chagasic esophageal achalasia and megacolon presented with nonproductive cough, chest pain and dyspnea. A chest X-ray showed bilateral opacity suggestive of lobar pneumonia. Open lung biopsy revealed lipoid pneumonia resulting from aspiration of mineral oil from a mineral oil-based laxative that the patient had been taking regularly for the last three years. The authors discuss concomitance of chagasic megacolon and esophageal achalasia with lipoid pneumonia and make recommendations regarding the use of mineral oil-based products by these patients.

  7. Understanding tectonic stress and rock strength in the Nankai Trough accretionary prism, offshore SW Japan

    Science.gov (United States)

    Huffman, Katelyn A.

    Understanding the orientation and magnitude of tectonic stress in active tectonic margins like subduction zones is important for understanding fault mechanics. In the Nankai Trough subduction zone, faults in the accretionary prism are thought to have historically slipped during or immediately following deep plate boundary earthquakes, often generating devastating tsunamis. I focus on quantifying stress at two locations of interest in the Nankai Trough accretionary prism, offshore Southwest Japan. I employ a method to constrain stress magnitude that combines observations of compressional borehole failure from logging-while-drilling resistivity-at-the-bit generated images (RAB) with estimates of rock strength and the relationship between tectonic stress and stress at the wall of a borehole. I use the method to constrain stress at Ocean Drilling Program (ODP) Site 808 and Integrated Ocean Drilling Program (IODP) Site C0002. At Site 808, I consider a range of parameters (assumed rock strength, friction coefficient, breakout width, and fluid pressure) in the method to constrain stress to explore uncertainty in stress magnitudes and discuss stress results in terms of the seismic cycle. I find a combination of increased fluid pressure and decreased friction along the frontal thrust or other weak faults could produce thrust-style failure, without the entire prism being at critical state failure, as other kinematic models of accretionary prism behavior during earthquakes imply. Rock strength is typically inferred using a failure criterion and unconfined compressive strength from empirical relations with P-wave velocity. I minimize uncertainty in rock strength by measuring rock strength in triaxial tests on Nankai core. I find strength of Nankai core is significantly less than empirical relations predict. I create a new empirical fit to our experiments and explore implications of this on stress magnitude estimates. I find using the new empirical fit can decrease stress

  8. ENVIRONMENTAL POLICY OF UKRAINE THROUGH THE PRISM OF MEMORY ON CHERNOBYL DISASTER

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    T. Perga

    2016-07-01

    Full Text Available The paper presents a new approach to the research of individual, collective and historical memory — through the prism of environmental disasters. Although they lead not only to physical but also to mental trauma in modern scientific discourse this aspect has not become a subject of special studies. In the example of Chernobyl disaster traumatic experience of 50 residents of Kiev, who received indirect effects of the accident, is analyzed. It is shown the formation a stable distrust of the authorities of the USSR, which is transferred to the present and entails a negative assessment of the environmental policy of independent Ukraine. Factors, which cause such situation and its relationship with the views of respondents on their future, are established. The conclusion of the feasibility of using the questionnaire method for determining the main trends traumatic impact of environmental disasters on individual memory is done. Directions for further in-depth research in this area are proposed.

  9. Astrophysical Information from Objective Prism Digitized Images: Classification with an Artificial Neural Network

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    Bratsolis Emmanuel

    2005-01-01

    Full Text Available Stellar spectral classification is not only a tool for labeling individual stars but is also useful in studies of stellar population synthesis. Extracting the physical quantities from the digitized spectral plates involves three main stages: detection, extraction, and classification of spectra. Low-dispersion objective prism images have been used and automated methods have been developed. The detection and extraction problems have been presented in previous works. In this paper, we present a classification method based on an artificial neural network (ANN. We make a brief presentation of the entire automated system and we compare the new classification method with the previously used method of maximum correlation coefficient (MCC. Digitized photographic material has been used here. The method can also be used on CCD spectral images.

  10. Large dynamic range SPR measurements in the visible using a ZnSe prism

    CERN Document Server

    Canning, John; Cook, Kevin

    2015-01-01

    Large dynamic index measurement range (n = 1 to n = 1.7) using surface plasmon resonance (SPR) shifts is demonstrated with a ZnSe prism at 632.8 nm, limited by the available high index liquid hosts. In contrast to borosilicate based SPR measurements where angular limitations restrict solvent use to water and requires considerable care dealing with Fresnel reflections, the ZnSe approach allows SPR spectroscopies to be applied to a varied range of solvents An uncertainty in angular resolution between 1.5 and 6 deg, depending on the solvent and SPR angle, was estimated. The refractive index change for a given glucose concentration in water was measured to be n = (0.114 to 0.007) per precentage C6H12O6 conc. Given the transmission properties of ZnSe the processes can be readily extended into the mid infrared.

  11. NATIONAL WORLD PICTURE THROUGH THE PRISM OF SOCIO-POLITICAL DISCOURSE

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    Kurganova, N.I.

    2016-06-01

    Full Text Available The article dwells on the methodological basis of studying the world picture specificity through the prism of social-political discourse. World picture as a system of knowledge, ideas, value judgments developed by all the members of a linguacultural community and represented in words and texts, reflects the results of a cognitive activity that permits to study it as a structured and systemic phenomenon. The authors propose a set of methods and procedures of modelling the parameters of world picture with special reference to the seasonal data collection from the Canadian newspaper Le Devoir (issued in French in the Province of Quebec, such as: distinguishing key concepts, modelling a cognitive, field, and semantic structure of concepts as elements of the world picture.

  12. Vortex array laser beam generation from a Dove prism-embedded unbalanced Mach-Zehnder interferometer.

    Science.gov (United States)

    Chu, Shu-Chun; Yang, Chao-Shun; Otsuka, Kenju

    2008-11-24

    This paper proposes a new scheme for generating vortex laser beams from a laser. The proposed system consists of a Dove prism embedded in an unbalanced Mach-Zehnder interferometer configuration. This configuration allows controlled construction of p x p vortex array beams from Ince-Gaussian modes, IG(e) (p,p) modes. An incident IG(e)(p,p) laser beam of variety order p can easily be generated from an end-pumped solid-state laser system with an off-axis pumping mechanism. This study simulates this type of vortex array laser beam generation, analytically derives the vortex positions of the resulting vortex array laser beams, and discusses beam propagation effects. The resulting vortex array laser beam can be applied to optical tweezers and atom traps in the form of two-dimensional arrays, or used to study the transfer of angular momentum to micro particles or atoms (Bose-Einstein condensate).

  13. Electrically controlled terahertz wave switch based on prism/liquid crystal

    Science.gov (United States)

    He, Meng-yao; Hu, Jian-rong; Li, Jiu-sheng

    2016-11-01

    We proposed a simple scheme to manipulate the position of the reflected terahertz wave beam based on the prism/liquid crystal structure. Both the stationary-phase method and finite element method are used to analyze and simulate the characteristics of the proposed device. To give comprehensive understanding, the position of the reflected terahertz wave beam is verified in simulation by using the COMSOL Multiphysics software. Numerical calculation results show that the proposed terahertz wave switch a high extinction ratio (35dB for TE polarization and 30dB for TM polarization). This provides an attractive way for creating a simple structure and compact size terahertz wave switch with acceptable extinction ratio.

  14. Palatini wormholes and energy conditions from the prism of General Relativity

    CERN Document Server

    Bejarano, C; Olmo, Gonzalo J; Rubiera-Garcia, D

    2016-01-01

    Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \\emph{designer} procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases, and how this is related to the same spacetimes when viewed from the modified gravity side.

  15. Determination of the topological charge of a twisted beam with a Fresnel bi-prism

    Science.gov (United States)

    Emile, Olivier; Emile, Janine; Brousseau, Christian

    2014-12-01

    The self-interference pattern of a Laguerre Gaussian beam using a Fresnel bi-prism is shown to be very different from what could be expected from a usual laser beam. It resembles the interference pattern that could be obtained using a double slit experiment. The interferences are shifted and the topological charge and its sign can be readily determined considering the shift order of the pattern only. However, since there is no diffraction nor absorption losses unlike in a double slit interference, such a set up could be used even for low power twisted beams or beams with high topological charge. Even fractional topological charges could be determined with an absolute precision of 0.05.

  16. Isoscalar monopole resonance of the alpha particle: a prism to nuclear Hamiltonians.

    Science.gov (United States)

    Bacca, Sonia; Barnea, Nir; Leidemann, Winfried; Orlandini, Giuseppina

    2013-01-25

    We present an ab initio study of the isoscalar monopole excitations of (4)He using different realistic nuclear interactions, including modern effective field theory potentials. In particular we concentrate on the transition form factor F(M) to the narrow 0(+) resonance close to threshold. F(M) exhibits a strong potential model dependence, and can serve as a kind of prism to distinguish among different nuclear force models. Compared to the measurements obtained from inelastic electron scattering off ^{4}He, one finds that the state-of-the-art theoretical transition form factors are at variance with experimental data, especially in the case of effective field theory potentials. We discuss some possible reasons for such a discrepancy, which still remains a puzzle.

  17. Concerted hydrogen-bond breaking by quantum tunneling in the water hexamer prism.

    Science.gov (United States)

    Richardson, Jeremy O; Pérez, Cristóbal; Lobsiger, Simon; Reid, Adam A; Temelso, Berhane; Shields, George C; Kisiel, Zbigniew; Wales, David J; Pate, Brooks H; Althorpe, Stuart C

    2016-03-18

    The nature of the intermolecular forces between water molecules is the same in small hydrogen-bonded clusters as in the bulk. The rotational spectra of the clusters therefore give insight into the intermolecular forces present in liquid water and ice. The water hexamer is the smallest water cluster to support low-energy structures with branched three-dimensional hydrogen-bond networks, rather than cyclic two-dimensional topologies. Here we report measurements of splitting patterns in rotational transitions of the water hexamer prism, and we used quantum simulations to show that they result from geared and antigeared rotations of a pair of water molecules. Unlike previously reported tunneling motions in water clusters, the geared motion involves the concerted breaking of two hydrogen bonds. Similar types of motion may be feasible in interfacial and confined water.

  18. Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients

    Science.gov (United States)

    Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Mejia, Carolina; Clark, Daniel E.; Choi, Jeong; Reimer-McAtee, Melissa J.; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

    2016-01-01

    Background Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. Methodology/Principal Findings T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Conclusion Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients. PMID:26919324

  19. Chronic Chagas' heart disease: a disease on its way to becoming a worldwide health problem: epidemiology, etiopathology, treatment, pathogenesis and laboratory medicine.

    Science.gov (United States)

    Muñoz-Saravia, Silvia Gilka; Haberland, Annekathrin; Wallukat, Gerd; Schimke, Ingolf

    2012-01-01

    Chagas' disease, caused by Trypanosoma cruzi infection, is ranked as the most serious parasitic disease in Latin America. Nearly 30% of infected patients develop life-threatening complications, and with a latency of 10-30 years, mostly Chagas' heart disease which is currently the major cause of morbidity and mortality in Latin America, enormously burdening economic resources and dramatically affecting patients' social and labor situations. Because of increasing migration, international tourism and parasite transfer by blood contact, intrauterine transfer and organ transplantation, Chagas' heart disease could potentially become a worldwide problem. To raise