Avaliação do comportamento das fibras colágenas periodontais durante a progressão da periodontite experimental em ratos / Evaluation of the behaviour of periodontal collagen fibers during the progression of experimental periodontitis in rats

Introdução: A periodontite é uma doença infecto-inflamatória, resultante da disbiose microbiana e da resposta do hospedeiro, que leva à destruição dos tecidos de suporte dentário, inclusive das fibras colágenas periodontais, podendo culminar na perda do elemento dental. Objetivo: Avaliar o comportamento das fibras colágenas periodontais durante a progressão da periodontite experimental induzida em ratos. Material e método: Doze ratos Wistar foram distribuídos nos grupos: Controle (C), Periodontite Experimental 14-dias (PE-14d), Periodontite Experimental 21-dias (PE-21d) e Periodontite Experimental 42-dias (PE-42d). No dia 0, os animais do grupo C foram eutanasiados. Neste mesmo dia, os animais remanescentes foram submetidos à instalação de uma ligadura de algodão ao redor do primeiro molar inferior esquerdo para indução da periodontite experimental. Tais animais foram eutanasiados aos 14 (PE-14d), 21 (PE-21d) e 42 (PE-42d) dias após a instalação da ligadura. Executou-se o processamento histológico das hemimandíbulas e as secções foram submetidas à reação histoquímica pelo vermelho picro-sirius. A análise qualitativa descritiva foi realizada sob microscopia de luz polarizada, na região de furca dental, evidenciando as fibras do ligamento periodontal. Resultado: O grupo C exibiu feixes espessos e orientados de fibras colágenas maduras, condizentes com aspecto de normalidade. Os grupos com periodontite experimental exibiram desestruturação tecidual severa, com fibras colágenas imaturas e de menor espessura, sendo tais condições mais exacerbadas nos grupos PE-14d e PE-21d. Conclusão: As fases iniciais da periodontite apresentam caráter agudo e, portanto, resultam na rápida destruição dos tecidos periodontais de suporte, prejudicando potencialmente a fibrilogênese e a reestruturação do colágeno no ligamento periodontal.

Introduction: Periodontitis is an infectious-inflammatory disease resulting from microbial dysbiosis and host response that leads to the destruction of tooth support tissues, including periodontal collagen fibers, which may culminate in tooth loss. Objective: To evaluate the behavior of periodontal collagen fibers during the progression of induced experimental periodontitis in rats. Material and method: Twelve Wistar rats were distributed into groups: Control (C), 14-days Experimental Periodontitis (PE-14d), 21-days Experimental Periodontitis (PE-21d) and 42-days Experimental Periodontitis (PE-42d). At day 0, the animals of group C were euthanized. At the same day, the remaining animals were submitted to the installation of a cotton ligature around the lower left first molar for the induction of experimental periodontitis. The animals were euthanized at 14 (PE-14d), 21 (PE-21d) and 42 (PE-42d) days after the installation of ligature. Histological processing of the hemi-mandibles was performed and the sections underwent histochemical reaction using picro-sirius red. The descriptive qualitative analysis was performed under polarized light microscopy, in the dental furcation region, evidencing the fibers of the periodontal ligament. Result: Group C exhibited thick and oriented bundles of mature collagen fibers, consistent with a normal appearance. The groups with experimental periodontitis exhibited severe tissue disruption, with immature and thinner collagen fibers, with such conditions being more exacerbated in the PE-14d and PE-21d groups. Conclusion: The early stages of periodontitis present acute response, and therefore result in rapid destruction of periodontal support tissues and potentially impair fibrillogenesis and collagen restructuring in the periodontal ligament.

Towards Tomography-Based Real-Time Control of Multiphase Flows: A Proof of Concept in Inline Fluid Separation.

The performance of multiphase flow processes is often determined by the distribution of phases inside the equipment. However, controllers in the field are typically implemented based on flow variables, which are simpler to measure, but indirectly connected to performance (e.g., pressure). Tomography has been used in the study of the distribution of phases of multiphase flows for decades, but only recently, the temporal resolution of the technique was sufficient for real-time reconstructions of the flow. Due to the strong connection between the performance and distribution of phases, it is expected that the introduction of tomography to the real-time control of multiphase flows will lead to substantial improvements in the system performance in relation to the current controllers in the field. This paper uses a gas-liquid inline swirl separator to analyze the possibilities and limitations of tomography-based real-time control of multiphase flow processes. Experiments were performed in the separator using a wire-mesh sensor (WMS) and a high-speed camera to show that multiphase flows have two components in their dynamics: one intrinsic to its nonlinear physics, occurring independent of external process disturbances, and one due to process disturbances (e.g., changes in the flow rates of the installation). Moreover, it is shown that the intrinsic dynamics propagate from upstream to inside the separator and can be used in predictive and feedforward control strategies. In addition to the WMS experiments, a proportional-integral feedback controller based on electrical resistance tomography (ERT) was implemented in the separator, with successful results in relation to the control of the distribution of phases and impact on the performance of the process: the capture of gas was increased from 76% to 93% of the total gas with the tomography-based controller. The results obtained with the inline swirl separator are extended in the perspective of the tomography-based control of quasi-1D multiphase flows.

A Fast Electrical Resistivity-Based Algorithm to Measure and Visualize Two-Phase Swirling Flows.

Electrical resistance tomography (ERT) has been used in the literature to monitor the gas-liquid separation. However, the image reconstruction algorithms used in the studies take a considerable amount of time to generate the tomograms, which is far above the time scales of the flow inside the inline separator and, as a consequence, the technique is not fast enough to capture all the relevant dynamics of the process, vital for control applications. This article proposes a new strategy based on the physics behind the measurement and simple logics to monitor the separation with a high temporal resolution by minimizing both the amount of data and the calculations required to reconstruct one frame of the flow. To demonstrate its potential, the electronics of an ERT system are used together with a high-speed camera to measure the flow inside an inline swirl separator. For the 16-electrode system used in this study, only 12 measurements are required to reconstruct the whole flow distribution with the proposed algorithm, 10× less than the minimum number of measurements of ERT (120). In terms of computational effort, the technique was shown to be 1000× faster than solving the inverse problem non-iteratively via the Gauss-Newton approach, one of the computationally cheapest techniques available. Therefore, this novel algorithm has the potential to achieve measurement speeds in the order of 104 times the ERT speed in the context of inline swirl separation, pointing to flow measurements at around 10kHz while keeping the average estimation error below 6 mm in the worst-case scenario.

Strategies to Prevent Sarcopenia in the Aging Process: Role of Protein Intake and Exercise.

Sarcopenia is one of the main issues associated with the process of aging. Characterized by muscle mass loss, it is triggered by several conditions, including sedentary habits and negative net protein balance. According to World Health Organization, it is expected a 38% increase in older individuals by 2025. Therefore, it is noteworthy to establish recommendations to prevent sarcopenia and several events and comorbidities associated with this health issue condition. In this review, we discuss the role of these factors, prevention strategies, and recommendations, with a focus on protein intake and exercise.

Electrical Resistance Tomography for Control Applications: Quantitative Study of the Gas-Liquid Distribution inside A Cyclone.

Phase separation based centrifugal forces is effective, and thus widely explored by the process industry. In an inline swirl separator, a core of the light phase is formed in the center of the device and captured further downstream. Given the inlet conditions, this gas core created varies in shape and size. To predict the separation behavior and control the process in an optimal way, the gas core diameter should be measured with the minimum possible intrusiveness. Process tomography techniques such as electrical resistance tomography (ERT) allows us to measure the gas core diameter in a fast and non-intrusive way. Due to the soft-field nature and ill-posed problem in solving the inverse problem, especially in the area of low spatial resolution, the reconstructed images often overestimate the diameter of the object under consideration leading to unreliable measurements. To use ERT measurements as an input for the controller, the estimated diameters should be corrected based on secondary measurements, e.g., optical techniques such as high-speed cameras. In this context, image processing and image analysis techniques were adapted to compare the diameter calculated by an ERT system and a fast camera. In this paper, a correction method is introduced to correct the diameter obtained by ERT based on static measurements. The proposed method reduced the ERT error of dynamic measurements of the gas core size from over 300% to below 20%, making it a reliable sensing technique for controlled separation processes.

Cryopreserved astrocytes maintain biological properties: Support of neuronal survival and differentiation.

BACKGROUND: Astrocytes, one of the main glial cell types, play critical roles in the central nervous system (CNS) development and function, including support of neuronal survival and differentiation, blood brain barrier formation, synapse homeostasis and injury response. Cell isolation and culture techniques have been proved to be a powerful tool to study astrocyte physiology and function. Due to financial constraints and rigid biosafety and ethics rules to use animal models, freezing techniques and the creation of cell banks emerged as alternatives to optimize the use of experimental animals. One of the main challenges, however, of these techniques is to guarantee that conserved cells keep their biological properties. NEW METHOD: In this work, we characterized morphologically and functionally murine secondary astrocyte cultures that have been submitted to freezing/thawing procedures. RESULTS: Morphological characterization of SAC (secondary astrocyte culture) and SFAC (secondary frozen-astrocyte culture) did not reveal significant differences on astrocyte morphology, confluence time and cell number along culture period. Functionally, SAC and SFAC did not reveal differences in their potential to support neuronal survival, maturation, neuritogenesis and synapse formation. CONCLUSIONS: Our results suggest that murine astrocytes that are submitted to freezing/thawing procedure maintain morphological and functional characteristics when compared with non-frozen astrocytes. Thus, this methodological approach is a valuable tool for in vitro research and might allow experimental optimization and reduction of animal use.

Astrocyte glutamate transporters are increased in an early sporadic model of synucleinopathy.

α-Synuclein protein (α-syn) is a central player in Parkinson's disease (PD) and in a spectrum of neurodegenerative diseases collectively known as synucleinopathies. These diseases are characterized by abnormal motor symptoms, such as tremor at rest, slowness of movement, rigidity of posture, and bradykinesia. Histopathological features of PD include preferential loss of dopaminergic neurons in the substantia nigra and formation of fibrillar intraneuronal inclusions called Lewy bodies and Lewy neurites, which are composed primarily of the α-syn protein. Currently, it is well accepted that α-syn oligomers (αSO) are the main toxic agent responsible for the etiology of PD. Glutamatergic excitotoxicity is associated with several neurological disorders, including PD. Excess glutamate in the synaptic cleft can be taken up by the astrocytic glutamate transporters GLAST and GLT-1. Although this event is the main defense against glutamatergic excitotoxicity, the molecular mechanisms that regulate this process have not yet been investigated in an early sporadic model of synucleinopathy. Here, using an early sporadic model of synucleinopathy, we demonstrated that the treatment of astrocytes with αSO increased glutamate uptake. This was associated with higher levels of GLAST and GLT-1 in astrocyte cultures and in a mouse model of synucleinopathy 24 h and 45 days after inoculation with αSO, respectively. Pharmacological inhibition of the TGF-ß1 (transforming growth factor beta 1) pathway in vivo reverted GLAST/GLT-1 enhancement induced by αSO injection. Therefore, our study describes a new neuroprotective role of astrocytes in an early sporadic model of synucleinopathy and sheds light on the mechanisms of glutamate transporter regulation for neuroprotection against glutamatergic excitotoxicity in synucleinopathy.

α-synuclein oligomers enhance astrocyte-induced synapse formation through TGF-ß1 signaling in a Parkinson's disease model.

Parkinson's disease (PD) is characterized by selective death of dopaminergic neurons in the substantia nigra, degeneration of the nigrostriatal pathway, increases in glutamatergic synapses in the striatum and aggregation of α-synuclein. Evidence suggests that oligomeric species of α-synuclein (αSO) are the genuine neurotoxins of PD. Although several studies have supported the direct neurotoxic effects of αSO on neurons, their effects on astrocytes have not been directly addressed. Astrocytes are essential to several steps of synapse formation and function, including secretion of synaptogenic factors, control of synaptic elimination and stabilization, secretion of neural/glial modulators, and modulation of extracellular ions, and neurotransmitter levels in the synaptic cleft. Here, we show that αSO induced the astrocyte reactivity and enhanced the synaptogenic capacity of human and murine astrocytes by increasing the levels of the known synaptogenic molecule transforming growth factor beta 1 (TGF-ß1). Moreover, intracerebroventricular injection of αSO in mice increased the number of astrocytes, the density of excitatory synapses, and the levels of TGF-ß1 in the striatum of injected animals. Inhibition of TGF-ß1 signaling impaired the effect of the astrocyte-conditioned medium on glutamatergic synapse formation in vitro and on striatal synapse formation in vivo, whereas addition of TGF-ß1 protected mesencephalic neurons against synapse loss triggered by αSO. Together, our data suggest that αSO have important effects on astrocytic functions and describe TGF-ß1 as a new endogenous astrocyte-derived molecule involved in the increase in striatal glutamatergic synaptic density present in early stages of PD. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Cover Image for this issue: doi: 10.1111/jnc.14514.

Vitamin D, muscle recovery, sarcopenia, cachexia, and muscle atrophy.

The relevance of vitamin D to skeletal muscle metabolism has been highlighted in recent years. The interest arises from the important findings of studies demonstrating multiple effects of vitamin D on this tissue, which can be divided into genomic (direct effects) and non-genomic effects (indirect effects). Another important aspect to be considered in the study of vitamin D and muscle fiber metabolism is related to different expression of vitamin D receptor (VDR), which varies in muscle tissue depending on age, sex, and pathology. The correlation between low circulating levels of vitamin D and muscle metabolism disorders is documented in various contexts, including muscle recovery, atrophy, sarcopenia, and cachexia. The aim of this review was to analyze recent results of both in vitro and in vivo studies to address the relationship between vitamin D and skeletal muscle biology. The words muscle atrophy, muscle hypertrophy, sarcopenia, and cachexia were crossed over with vitamin D in a Pubmed search. All original contributions, along with reviews on the topic, were included, and no publications in the past 10 y were discarded. The papers retrieved different topics such as vitamin D in skeletal muscle; vitamin D in circulation; vitamin D, sarcopenia, and muscle atrophy; vitamin D and cachexia; and vitamin D and muscle recovery.

Exergy Analysis and Human Body Thermal Comfort Conditions: Evaluation of Different Body Compositions.

This article focuses on studying the effects of muscle and fat percentages on the exergy behavior of the human body under several environmental conditions. The main objective is to relate the thermal comfort indicators with exergy rates, resulting in a Second Law perspective to evaluate thermal environment. A phenomenological model is proposed of the human body with four layers: core, muscle, fat and skin. The choice of a simplified model is justified by the facility to variate the amount of mass in each tissue without knowing how it spreads around the body. After validated, the model was subjected to a set of environmental conditions and body compositions. The results obtained indicate that the area normalization (Watts per square meter) may be used as a safe generalization for the exergy transfer to environment. Moreover, the destroyed exergy itself is sufficient to evaluate the thermal sensation when the model is submitted to environmental temperatures lower than that considered for the thermal neutrality condition (and, in this text, the thermal comfort) . Nevertheless, for environments with temperatures higher than the calculated for the thermal neutrality, the combination of destroyed exergy and the rate of exergy transferred to the environment should be used to properly evaluate thermal comfort.

Design and Characterization of a Novel p1025 Peptide-Loaded Liquid Crystalline System for the Treatment of Dental Caries.

Dental caries, mainly caused by the adhesion of Streptococcus mutans to pellicle-coated tooth surfaces, is an important public health problem worldwide. A synthetic peptide (p1025) corresponding to residues 1025-1044 of the adhesin can inhibit this binding. Peptides are particularly susceptible to the biological environment; therefore, a p1025 peptide-loaded liquid crystalline system (LCS) consisting of tea tree oil as the oil phase, polyoxypropylene-(5)-polyoxyethylene-(20)-cetyl alcohol as the surfactant, and water or 0.5% polycarbophil polymer dispersions as the aqueous phase was employed as a drug delivery platform. This system exhibited anticaries and bioadhesive properties and provided a protective environment to p1025 at the site of action, thereby modulating its action, prolonging its contact with the teeth, and decreasing the frequency of administration. LCSs were characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), and rheological, texture, and bioadhesive tests. PLM and SAXS revealed the presence of hexagonal liquid crystalline phases and microemulsions. Rheological analyses demonstrated that the addition of polymer dispersions favored characteristics such as shear thinning and thixotropy, hence improving buccal application. Bioadhesion tests showed that polymer dispersions contributed to the adhesion onto the teeth. Taken together, LCS could provide a novel pharmaceutical nanotechnology platform for dental caries treatment.

Astrocytic control of neural circuit formation: highlights on TGF-beta signaling.

Brain function depends critically on the coordinated activity of presynaptic and postsynaptic signals derived from both neurons and non-neuronal elements such as glial cells. A key role for astrocytes in neuronal differentiation and circuitry formation has emerged within the last decade. Although the function of glial cells in synapse formation, elimination and efficacy has greatly increased, we are still very far from deeply understanding the molecular and cellular mechanism underlying these events. The present review discusses the mechanisms driving astrocytic control of excitatory and inhibitory synapse formation in the central nervous system, especially the mechanisms mediated by soluble molecules, particularly those from the TGF-ß family. Further, we discuss whether and how human astrocytes might contribute to the acquisition of human cognition. We argue that understanding how astrocytic signals regulate synaptic development might offer new insights into human perception, learning, memory, and cognition and, ultimately, provide new targets for the treatment of neurological diseases.

Astrocyte transforming growth factor beta 1 promotes inhibitory synapse formation via CaM kinase II signaling.

The balance between excitatory and inhibitory synaptic inputs is critical for the control of brain function. Astrocytes play important role in the development and maintenance of neuronal circuitry. Whereas astrocytes-derived molecules involved in excitatory synapses are recognized, molecules and molecular mechanisms underlying astrocyte-induced inhibitory synapses remain unknown. Here, we identified transforming growth factor beta 1 (TGF-ß1), derived from human and murine astrocytes, as regulator of inhibitory synapse in vitro and in vivo. Conditioned media derived from human and murine astrocytes induce inhibitory synapse formation in cerebral cortex neurons, an event inhibited by pharmacologic and genetic manipulation of the TGF-ß pathway. TGF-ß1-induction of inhibitory synapse depends on glutamatergic activity and activation of CaM kinase II, which thus induces localization and cluster formation of the synaptic adhesion protein, Neuroligin 2, in inhibitory postsynaptic terminals. Additionally, intraventricular injection of TGF-ß1 enhanced inhibitory synapse number in the cerebral cortex. Our results identify TGF-ß1/CaMKII pathway as a novel molecular mechanism underlying astrocyte control of inhibitory synapse formation. We propose here that the balance between excitatory and inhibitory inputs might be provided by astrocyte signals, at least partly achieved via TGF-ß1 downstream pathways. Our work contributes to the understanding of the GABAergic synapse formation and may be of relevance to further the current knowledge on the mechanisms underlying the development of various neurological disorders, which commonly involve impairment of inhibitory synapse transmission.

Factores asociados a fibrinolisis fallida con estreptokinasa post infarto agudo de miocardio / Factors associated to fibrinolisis unsuccessful with estreptokinasa post acute heart attack of myocardium

Antecedentes. En nuestro país como en el resto del mundo, la fibrinolisis intravenosa mas aspirina y heparina no fraccionada es el tratamiento más ampliamente utilizado en los pacientes con infarto agudo de miocardio (IMA), siendo la estreptokinasa (SK) el agente fibrinolítico más frecuentemente utilizado. Sin embargo, no todos los pacientes alcanzan la deseada reperfusión tisular y en ellos se ha observado mayores efectos adversos. Objetivo. Identificar los factores clínico-epidemiológicos mas frecuentemente asociados al diagnóstico de Fibrinolisis Fallida (FF), que contribuya a direccionar la terapia mas adecuada en este subgrupo de pacientes de alto riesgo. Métodos. Estudio de tipo analítico retrospectivo que comprendió a 120 pacientes que acudieron dentro de las 6 horas de un IMA a la emergencia del Hospital Alberto Sabogal del Callao-EsSalud y recibieron terapia fibrinolítica con SK entre julio 1994 y abril 2002. Se definió FF como la ausencia de resolución del ST mayor al 50 por ciento dentro de las 2 horas de iniciada la fibrinolisis en relación a un electrocardiograma basal. Resultados. 53 por ciento ( n=64 ) de los pacientes resultaron en FF. Luego de analizar independientemente las variables, solo la presencia simultanea de multiples ( mayor de 3) factores de riesgo se asoció al fracaso de la fibrinolisis (p=0,03). Estos pacientes tuvieron en general un menor promedio de edad (62 vs 67 años), una localización anterior del IMA (62 por ciento vs 50 por ciento) y se presentaron con signos de congestión pulmonar en la emergencia (37 por ciento vs 18 por ciento), sin embargo, estas diferencias no alcanzaron significación estadística. Por otro lado, la FF se asoció a disfunción severa del ventrículo izquierdo en el ecocardiograma control (p=0,004) y mayores efectos adversos en el primer año (p=0,01). Conclusiones. La presencia simultanea de múltiples factores de riesgo en los pacientes con IMA puede ser un predictor de fracaso de la...

In our country as in many parts of the world, intravenous fibrinolysis plus heparin and aspirin is the most commonly used treatment in patients with acute myocardial infarction (AMI), being Streptokinase (SK) the most frequently used fibrinolytic agent. But not all patients reach tisular reperfusion and they have the worse outcomes. Objective. To identify the clinical and epidemiological factors most frequently associated to the diagnosis of Failed Fibrinolysis (FF). Methods. Analytic and Retrospective study of 120 patients that arrived to the emergency room of the Alberto Sabogal Hospital- EsSalud in Peru, within the first 6 hours of an acute myocardial infarction and were trated with intravenous Streptokinase between july 1994 and april 2002. Failed fibrinolysis was defined as the absence of ST resolution greater than 50 per cent when compared with a basal electrocardiogram. Results. 53 per cent (n=64) patients resulted in FF. Only the presence of several ( greater than 3) risk factors was associated with FF (p=0,03). This patients were younger (62 vs 67 years old), had mostly anterior wall myocardial infarctions (62 per cent vs 50 per cent), and presented with pulmonary congestion at the ER (37 per cent vs 18 per cent), but this differences were not statistically significant. FF also was associated to severe left ventricular dysfunction in the ultrasound exam (p=0,004) and greater adverse effects in the first year outcome (p=0,01). Conclusion. The simultaneous presence of several (grater than 3) major risk factors can be a predictor of FF with SK in patients with AMI. FF was associated to severe left ventricular dysfunction, greater adverse events in the first year and consequently worse prognosis.

Uso de la energía de microondas en el procesamiento de prótesis odontológicas / Use of microwave energy in processing dental prostheses

Se han propuesto métodos alternativos de procesamiento de resina para prótesis odontológicas, en el sentido de perfeccionar las técnicas y los resultados de prótesis removibles, sean parciales o totales. En este trabajo, los autores hacen una revisión crítica de la técnica del procesamiento por energía de microondas, en la cual se explican las investigaciones desarrolladas para evaluar los pros y los contras de su uso como método alternativo de polimerización de las resinas para base de prótesis. En este contexto, los autores concluyen que este método, a pesar de ser relativamente reciente, es plausible de ser utilizado en la elaboración de trabajos protéticos, por tratarse de una técnica sencilla, limpia y rápida, admitiendo trabajos con calidad equivalente a la de los métodos convencionales (AU)

Uso de la energía de microondas en el procesamiento de prótesis odontológicas / Uso da energia de microondas no processamento de próteses odontológicas

Se han propuesto métodos alternativos de procesamiento de resina para prótesis odontológicas, en el sentido de perfeccionar las técnicas y los resultados de prótesis removibles, sean parciales o totales. En este trabajo, los autores hacen una revisión crítica de la técnica del procesamiento por energía de microondas, en la cual se explican las investigaciones desarrolladas para evaluar los pros y los contras de su uso como método alternativo de polimerización de las resinas para base de prótesis. En este contexto, los autores concluyen que este método, a pesar de ser relativamente reciente, es plausible de ser utilizado en la elaboracíon de trabajos protéticos, por tratarse de una técnica sencilla, limpia y rápida, admitiendo trabajos con calidad equivalente a la de los métodos convencionales

Enfermedad cerebrovascular: factores de riesgo en los adultos nativos de la altura, HCRI-IPSS, 1989-1992 / Cerebrovascular diseases: risk factors in the natives adults of the high, HCRI-IPSS, 1989-1992

En grandes estudios prospectivos poblacionales realizados a nivel del mar, se han identificado a los principales factores de riesgo para Enfermedad Cerebrovascular (ECV); en todos ellos, la hipertensión arterial resultó ser el más importante. En los nativos de la altura, no sólo se ha descrito una menor prevalencia de hipertensión, sino también de otros factores relacionados al riesgo de ECV, como la aterosclerosis, la cardiopatía coronaria, la diabetes y la hipercolesterolemia. Con la finalidad de conocer la importancia de la hipertensión arterial como factor de riesgo para ECV, e identificar a los principales factores de riesgo para esta enfermedad en los nativos de la altura, se diseño un estudio retrospectivo de tipo caso-control que comprendió la investigación de los factores de riesgo en 50 pacientes adultos nativos de la altura que con diagnóstico confirmado de ECV fueron hospitalizados en el HCRI-IPSS del Cusco entre Junio de 1989 y Agosto de 1992. Se concluyó que la aterosclerosis fue el factor causal más importante para ECV en los adultos nativos de la altura (p<0.001), seguida de la hipertensión (p=0.02) y la fibrilación auricular no reumática (p=0.01). La edad avanzada, la ingesta frecuente de alcohol y el antecedente de ECV previa, fueron factores contributorios. Se encontró además una edad significativamente mas tardía de presentación del infarto cerebral aterotrombótico en los nativos de la altura respecto a los del nivel del mar, lo cual sugiere que el proceso aterosclerótico en la altura tiene características particulares que ameritan mayor investigación.