scholarly journals Chagas disease: What is known and what should be improved: a systemic review

2012 ◽  
Vol 45 (3) ◽  
pp. 286-296 ◽  
Author(s):  
José Rodrigues Coura ◽  
José Borges-Pereira

This study consists of a broad review on what is known and what should be improved regarding knowledge of Chagas disease, not only through analysis on the main studies published on the topics discussed, but to a large extent based on experience of this subject, acquired over the past 50 years (1961-2011). Among the subjects covered, we highlight the pathogenesis and evolution of infection by Trypanosoma cruzi, drugs in use and new strategies for treating Chagas disease; the serological tests for the diagnosis and the controls of cure the infection; the regional variations in prevalence, morbidity and response to treatment of the disease; the importance of metacyclogenesis of T. cruzi in different species of triatomines and its capacity to transmit Chagas infection; the risks of adaptation of wild triatomines to human dwellings; the morbidity and need for a surveillance and control program for Chagas disease in the Amazon region and the need to prioritize initiatives for controlling Chagas disease in Latin America and Mexico and in non-endemic countries, which is today a major international dilemma. Finally, we raise the need for to create a new initiative for controlling Chagas disease in the Gran Chaco, which involves parts of Argentina, Bolivia and Paraguay.

Author(s):  
Cláudia M. Melo ◽  
Ana Carla F. G. Cruz ◽  
Antônio Fernando V. A. Lima ◽  
Luan R. Silva ◽  
Rubens R. Madi ◽  
...  

Updated information of the dispersion dynamics of Chagas disease (CD) and a systemic analysis of these data will aid the early identification of areas that are vulnerable to transmission and enable efficient intervention. This work synthesized spatiotemporal information regarding triatomine fauna and analyzed this information in combination with the results from serological tests to elucidate the epidemiological panorama of CD in the state of Sergipe, Brazil. This is a retrospective analytical study that utilized information from the database of the National Chagas Disease Control Program. Between 2010 and 2016, 838 triatomines of eight species, namely, Panstrongylus geniculatus, which was first recorded in the state of Sergipe, Panstrongylus lutzi, P. megistus, Triatoma brasiliensis, T. pseudomaculata, T. tibiamaculata, T. melanocephala, and Rhodnius neglectus, were collected. Optical microscopy revealed that 13.2% of triatomines examined were infected by Trypanosoma cruzi-like flagellates. The distribution of triatomines exhibits an expanding south-central to northern dispersion, with a preference for semiarid and agreste areas and occasional observations in humid coastal areas due to anthropogenic actions reflected in the environment. Of the human cases analyzed from 2012 to 2016, 8.3% (191/2316) presented positive serology for Trypanosoma cruzi, and this proportion showed a gradual increase in the southern center of the state and new notifications in coastal regions. There is a need for intensification and continuity of the measures adopted by the Chagas Disease Control Program in Sergipe, identifying new priority areas for intervention and preferential ecotopes of the vectors, considering the occurrence of positive triatomines intradomicilliary and a source of new triatomines in the peridomiciles.


2020 ◽  
Vol 11 ◽  
Author(s):  
Konstantinos Lazaridis ◽  
Socrates J. Tzartos

Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction, characterized by skeletal muscle weakness and fatigability. It is caused by autoantibodies targeting proteins of the neuromuscular junction; ~85% of MG patients have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 5% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). In the remaining about 10% of patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG). Since serological tests are relatively easy and non-invasive for disease diagnosis, the improvement of methods for the detection of known autoantibodies or the discovery of novel autoantibody specificities to diminish SN-MG and to facilitate differential diagnosis of similar diseases, is crucial. Radioimmunoprecipitation assays (RIPA) are the staple for MG antibody detection, but over the past years, using cell-based assays (CBAs) or improved highly sensitive RIPAs, it has been possible to detect autoantibodies in previously SN-MG patients. This led to the identification of more patients with antibodies to the classical antigens AChR and MuSK and to the third MG autoantigen, the low-density lipoprotein receptor-related protein 4 (LRP4), while antibodies against other extracellular or intracellular targets, such as agrin, Kv1.4 potassium channels, collagen Q, titin, the ryanodine receptor and cortactin have been found in some MG patients. Since the autoantigen targeted determines in part the clinical manifestations, prognosis and response to treatment, serological tests are not only indispensable for initial diagnosis, but also for monitoring treatment efficacy. Importantly, knowing the autoantibody profile of MG patients could allow for more efficient personalized therapeutic approaches. Significant progress has been made over the past years toward the development of antigen-specific therapies, targeting only the specific immune cells or autoantibodies involved in the autoimmune response. In this review, we will present the progress made toward the development of novel sensitive autoantibody detection assays, the identification of new MG autoantigens, and the implications for improved antigen-specific therapeutics. These advancements increase our understanding of MG pathology and improve patient quality of life by providing faster, more accurate diagnosis and better disease management.


2019 ◽  
Vol 26 (7) ◽  
Author(s):  
Francesca F Norman ◽  
Rogelio López-Vélez

AbstractBackgroundChagas disease, or American trypanosomiasis, is a protozoan infectious disease endemic throughout most of the Americas, caused by the trypanosome, Trypanosoma cruzi, and mainly transmitted to humans by reduviid or kissing bugs. Some progress has been achieved in control of the disease mainly in endemic areas, but migration flows have acted as drivers for the emergence of the disease mainly in non-endemic areas of Europe and North America. Most imported cases of Chagas disease in Europe are reported in migrants from highly endemic areas of countries such as Bolivia and Paraguay, and reports of Chagas disease in travellers are extremely rare.MethodsPan American Health Organization (PAHO) recently updated their guidelines on the diagnosis and management of Chagas. These guidelines and their applicability to migrants and travellers are reviewed.ResultsPAHO recommends the use of two serological tests for diagnosis of chronic infection (allowing for the use of a single sensitive test followed by confirmation in special settings such as the screening of potential blood donors). The indication for specific trypanocidal treatment of acute infections, children and women of child-bearing age remains as before, with either benznidazole or nifurtimox being the treatment of choice. For chronic infection with/without organ damage, treatment recommendations are less well defined. Although treatment is generally not recommended in patients with visceral involvement, decisions regarding treatment need to be tailored to the individual. Either benznidazole or nifurtimox may be used for initial treatment.ConclusionsThe recent PAHO Guidelines provide a framework to aid the diagnosis and management of this infection, but several aspects such as the underdiagnosis of infections, the multidisciplinary approach to patient management, the investigation of novel biomarkers of disease progression/response to treatment and the development of new treatment strategies are areas which should be further strengthened.


Author(s):  
Kenneth S. Vecchio ◽  
John A. Hunt

In-situ experiments conducted within a transmission electron microscope provide the operator a unique opportunity to directly observe microstructural phenomena, such as phase transformations and dislocation-precipitate interactions, “as they happen”. However, in-situ experiments usually require a tremendous amount of experimental preparation beforehand, as well as, during the actual experiment. In most cases the researcher must operate and control several pieces of equipment simultaneously. For example, in in-situ deformation experiments, the researcher may have to not only operate the TEM, but also control the straining holder and possibly some recording system such as a video tape machine. When it comes to in-situ fatigue deformation, the experiments became even more complicated with having to control numerous loading cycles while following the slow crack growth. In this paper we will describe a new method for conducting in-situ fatigue experiments using a camputer-controlled tensile straining holder.The tensile straining holder used with computer-control system was manufactured by Philips for the Philips 300 series microscopes. It was necessary to modify the specimen stage area of this holder to work in the Philips 400 series microscopes because the distance between the optic axis and holder airlock is different than in the Philips 300 series microscopes. However, the program and interfacing can easily be modified to work with any goniometer type straining holder which uses a penrmanent magnet motor.


2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.


2017 ◽  
Vol 63 (3) ◽  
pp. 461-465
Author(s):  
Lev Bershteyn ◽  
Dmitriy Vasilev ◽  
Tatyana Poroshina ◽  
Igor Berlev

Increased frequency of endometrial cancer (EC) since the beginning of this century exceeds that of breast cancer and to a large extent can be attributed to dynamics of parameters, which characterize hormonal and metabolic status of ill women and molecular genetic landscape of transforming endometrium. During the past few years there are suggested several options for a personalized assessment of the risk of EC. The aim of this article is to propose and justify own version of this score with the idea of its further not only retrospective but also prospective testing both in relation to the risk of developing endometrial cancer as well as an additional marker helping to predict tumor response to treatment.


2020 ◽  
Vol 16 ◽  
Author(s):  
Patricio Lopez-Jaramillo ◽  
Jose Lopez-Lopez ◽  
Daniel Cohen ◽  
Natalia Alarcon-Ariza ◽  
Margarita Mogollon-Zehr

: Hypertension and type 2 diabetes mellitus are two important risk factors that contribute to cardiovascular diseases worldwide. In Latin America hypertension prevalence varies from 30 to 50%. Moreover, the proportion of awareness, treatment and control of hypertension is very low. The prevalence of type 2 diabetes mellitus varies from 8 to 13% and near to 40% are unaware of their condition. In addition, the prevalence of prediabetes varies from 6 to 14% and this condition has been also associated with increased risk of cardiovascular diseases. The principal factors linked to a higher risk of hypertension in Latin America are increased adiposity, low muscle strength, unhealthy diet, low physical activity and low education. Besides being chronic conditions, leading causes of cardiovascular mortality, both hypertension and type 2 diabetes mellitus represent a substantial cost for the weak health systems of Latin American countries. Therefore, is necessary to implement and reinforce public health programs to improve awareness, treatment and control of hypertension and type 2 diabetes mellitus, in order to reach the mandate of the Unit Nations of decrease the premature mortality for CVD.


1926 ◽  
Vol 20 (1) ◽  
pp. 14-30
Author(s):  
Percy Alvin Martin

To students of international relations it has become almost a commonplace that among the most significant and permanent results of the World War has been the changed international status of the republics of Latin America. As a result of the war and post-war developments in these states, the traditional New World isolation in South America, as well as in North America, is a thing of the past. To our leading sister republics is no longer applicable the half-contemptuous phrase, current in the far-off days before 1914, that Latin America stands on the margin of international life. The new place in the comity of nations won by a number of these states is evidenced—to take one of the most obvious examples—by the raising of the legations of certain non-American powers to the rank of embassies, either during or immediately after the war. In the case of Brazil, for instance, where prior to 1914 only the United States maintained an ambassador, at the present time Great Britain, France, Italy, Belgium, Portugal, and Japan maintain diplomatic representatives of this rank.Yet all things considered one of the most fruitful developments in the domain of international relations has been the share taken by our southern neighbors in the work of the League of Nations. All of the Latin American republics which severed relations with Germany or declared war against that country were entitled to participate in the Peace Conference. As a consequence, eleven of these states affixed their signatures to the Treaty of Versailles, an action subsequently ratified in all cases except Ecuador.


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