ABSTRACT
Normal function and the most common problems that occur during pacemaker operation while performing physical exercise, are discussed. Physically active individuals with an implantable cardiac device, should be evaluated during exercise, because some conflicts issues may arise that are not detectable during routine, at rest, telemetry.
ABSTRACT
In Brazil, there are about 2.5 million tubular wells in which 88% of them are illegal, extracting more than 17,580 Mm3/yr. This irregular use may cause sustainability issues that may be economic, social, or environmental (overexploitation, well losses and associated increases of water conflicts; aquifer contamination; and land subsidence). This paper aims to address the illegal wells in Brazil and discuss measures to minimize it. Conclusions indicate that users do not understand the aquifer dynamic and, therefore, do not have a proper understanding of problems such as loss of water quality and quantity caused by the excess of groundwater exploitation. This creates a false idea that there are no water conflicts among users, which causes a lack of engagement by society. Without groundwater users and stakeholder pressure, the government does not aim to control or close illegal wells, and the "vicious cycle" persists. The one way to break this "vicious cycle" would be programs of social communication and users' participation, coupled with improvements to the control apparatus and inspection from State institutions, making sure that there is correct management and not only legislations that are not applied.
Subject(s)
Groundwater , Water Pollutants, Chemical , Brazil , Environmental Monitoring , Water Pollutants, Chemical/analysis , Water Quality , Water Supply , Water WellsABSTRACT
Snake venom may vary in composition and toxicity across the geographic distribution of a species. In the case of the three species of the Neotropical rattlesnakes Crotalus simus, C. culminatus and C. tzabcan recent research has revealed that their venoms can contain a neurotoxic component (crotoxin homologs), but is not always the case. In the present work, we detected and quantified crotoxin homologs in venom samples from three species distributed across Mexico, to describe variation at the individual and subspecific levels, using slot blot and ELISA immunoassays. We found that all C. simus individuals analyzed had substantial percentages of crotoxin homologs in their venoms (7.6-44.3%). In contrast, C. culminatus lacked them completely and six of ten individuals of the species C. tzabcan had low percentages (3.0-7.7%). We also found a direct relationship between the lethality of a venom and the percentage of crotoxin homologs it contained, indicating that the quantity of this component influences venom lethality in the rattlesnake C. simus.
ABSTRACT
A 12-lead electrocardiogram (ECG) of a dual-chamber pacemaker with different paced QRS morphologies is presented. Such an observation is usually made when there are different degrees of fusion, in association with the intrinsic rhythm in the presence of spontaneous changes of the stimulation mode of the pacemaker.
ABSTRACT
MicroRNAs (miRNAs) are endogenous small non-coding RNAs that have a pivotal role in the post-transcriptional regulation of gene expression and their misregulation is common in different types of cancer. Although it has been shown that miR-7 plays an oncogenic role in different cellular contexts, the molecular mechanisms by which miR-7 promotes cell transformation are not well understood. Here we show that the transcription factor KLF4 is a direct target of miR-7 and present experimental evidence indicating that the regulation of KLF4 by miR-7 has functional implications in epithelial cell transformation. Stable overexpression of miR-7 into lung and skin epithelial cells enhanced cell proliferation, cell migration and tumor formation. Alteration of these cellular functions by miR-7 resulted from misregulation of KLF4 target genes involved in cell cycle control. miR-7-induced tumors showed decreased p21 and increased Cyclin D levels. Taken together, these findings indicate that miR-7 acts as an oncomiR in epithelial cells in part by directly regulating KLF4 expression. Thus, we conclude that miR-7 acts as an oncomiR in the epithelial cellular context, where through the negative regulation of KLF4-dependent signaling pathways, miR-7 promotes cellular transformation and tumor growth.
Subject(s)
Cell Transformation, Neoplastic/metabolism , Cell Transformation, Neoplastic/pathology , Epithelial Cells/metabolism , Epithelial Cells/pathology , Kruppel-Like Transcription Factors/metabolism , MicroRNAs/metabolism , 3' Untranslated Regions/genetics , Animals , Base Sequence , Binding Sites , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Conserved Sequence/genetics , Cyclin D/metabolism , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Down-Regulation/genetics , Evolution, Molecular , Gene Expression Regulation, Neoplastic , Humans , Kruppel-Like Factor 4 , Male , Mice, Nude , MicroRNAs/genetics , Molecular Sequence Data , Protein Binding/genetics , S Phase/genetics , Tumor Stem Cell AssayABSTRACT
Non-pharmacological preventive treatment of sustained ventricular arrhythmias in chagasic disease is a challenge. Given that the involvement of the autonomic nervous system is one of its determinants, thoracic sympathectomy could be a valuable tool in some selected cases.
Subject(s)
Chagas Cardiomyopathy/therapy , Death, Sudden, Cardiac/prevention & control , Autonomic Nervous System/physiopathology , Autonomic Nervous System/surgery , Chagas Cardiomyopathy/physiopathology , Chronic Disease , Humans , SympathectomyABSTRACT
Management of complex ventricular arrhythmias due to chagasic myocarditis is challenging. We herein present the case of a young male who was presented with incessant well tolerated polymorphic ventricular tachycardia of unknown cause, who was unresponsive to conventional medical management and as a last resort was submitted to a thoracoscopic bilateral sympathectomy, and showed remarkable improvement in his arrhythmia control. Later on his tests returned positive for Chagas' disease and shortly thereafter he suddenly died.
Subject(s)
Chagas Cardiomyopathy/complications , Chagas Cardiomyopathy/surgery , Sympathectomy/methods , Tachycardia, Ventricular/parasitology , Tachycardia, Ventricular/surgery , Adult , Electrocardiography , Fatal Outcome , Humans , MaleABSTRACT
Se presenta el caso de un paciente con distrofia miotónica o enfermedad de Steinert, quien presentó taquicardia ventricular sostenida con daño miocárdico y que requirió terapia con cardiodesfibrilador implantable.
Subject(s)
Humans , Male , Middle Aged , Defibrillators, Implantable , Myotonic Dystrophy , Tachycardia, VentricularABSTRACT
Se presenta un caso de doble fístula coronaria, desde arteria circunfleja al atrio derecho y desde la arteria coronaria derecha al seno coronario, con grave repercusión hemodinámica con dilatación e hiperflujo en cámaras derechas.
Subject(s)
Humans , Female , Aged , Arterio-Arterial Fistula , Coronary Disease , Costa RicaABSTRACT
Introducción: Estudios internacionales recientes han mostrado que la actualidad la insufiencia valvular mitral se debe principalmente a degeneración mixomatosa de la válvula o la enfermedad arterial coronaria. Este estudio ecocardiográfico tiene como objetivo establecer la prevalencia de las diferentes causas de insuficiencia mitral pura en Costa Rica. Metodología: Se incluyeron a todos aquellos pacientes referidos a nuestro laboratorio de eocardiografía en el período comprendido entre el mes de julio de 1998 y julio del 2000 en quienes se detectó insuficiencia mitral de causa orgánica. Se realizó la exploración en modo M, bidimensional y con las técnicas de mapeo con doppler pulsado, continuo y color y se clasificó a los casos en reumática, prolapso de la válvula mitral por degeneración mixoide, isquémica, degenerativa, secundaria a endocarditis, por colagenopatía y otras, según definiciones convencionales. También se valoró semicuantitativamente la severidad de la regurgitación clasificándose en leve, moderada y severa...
Subject(s)
Humans , Male , Adolescent , Adult , Middle Aged , Female , Echocardiography , Mitral Valve Insufficiency/diagnosis , Mitral Valve Insufficiency/etiology , Costa RicaABSTRACT
Una complicación de la diabetes mellitus es la neuropatía autonómica...
Subject(s)
Humans , Middle Aged , Diabetes Mellitus/complications , Heart Rate/physiology , Diabetic Neuropathies/diagnosis , Diabetic Neuropathies/etiology , Costa RicaABSTRACT
La cateterización del corazón en electrofisiología se ha venido utilizando con fines...
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/physiopathology , Arrhythmias, Cardiac/prevention & control , Arrhythmias, Cardiac/therapy , Catheterization , Tachycardia/diagnosis , Tachycardia/etiology , Costa RicaABSTRACT
Os autores relatam um caso de pseudoporfiria cutânea, tardia, que se desenvolveu em paciente portador de insuficiência renal crônica terminal, em programa de hemodiálise. Discutem-se possíveis fatores etiológicos relacionados a esta condiçäo clínica
