Revistas Científicas de la Universidad Peruana Cayetano Heredia
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Efecto del ejercicio a altura moderada sobre IgA secretoria y cortisol salival
No full textNuestro objetivo fue evaluar si el ritmo circadiano del cortisol y los niveles de lgA secretoria (lgAs) se alteraban por ejercicio intenso en altitud moderada. Materiales y Métodos: Se evaluaron 4 escaladores masculinos. La travesía duró 5 días. alcanzando una altura máxima de 4270 msnm. Se tomaron muestras de sangre antes y después del viaje. Durante el ascenso, se recolectaron muestras de saliva cada mañana y cada noche en tubos estériles manteniéndolas a temperatura inferior a 10ºC. El mal agudo de montaña (MAM) se evaluó con el test de Lake Louise. Los resultados se presentan como promedio y DS. Resultados: los participantes no mostraron déficit previo de cortisol: 14,7ug/dl (3.45) y todos mantuvieron el ritmo circadiano: mañana: 0,87ug/dl (0,37) vs noche: 0,32ug/dl (0,22) (p<0,01); dos de ellos presentaron MAM moderado que normalizaron con la aclimatación. El cortisol salival matutino mostró valores superiores a mayor altitud (r: 0,27). Ninguno de los participantes tenía déficit previo de lgA o lgAs: 162mg% (52,3) y 17,9mg% (8,64) respectivamente. Los valores de lgAs matinal fueron superiores a los nocturnos: 21,03 mg% (18,9) vs 9,88 mg% (7,50) p: 0,03. El coeficiente de correlación entre lgA y cortisol salival fue positivo (r: 0,35). Conclusión: La potencia estadística es baja debido al número de escaladores. Este hecho no nos permite establecer conclusiones firmes. pero el ritmo circadiano del cortisol no fue alterado por ejercicio intenso en altitud moderada ni por el MAM moderado. Los niveles elevados de cortisol salival no afectaron a la producción de lgA
Neocytolysis in the adaptation of red cell mass on descent from altitude
No full textAcclimated individuals descending from high altitude must rapidly adapt to plethora, an excess in red cell mass and blood volume for their new environment. We believe that this is accomplished by neocytolysis, the selective destruction of the youngest red blood cells, physiologic process we recently discovered through studies on astronauts. On entering microgravity, an astronaut's blood distributes centrally causing acute plethora. There ensues a reproducible 10% decline in red ceil mass in the first several days in space. Red cell production does not decline in these first days, and survival of labeled older red cells is normal. The inescapable. conclusion is that neocytolysis ensues. Studies done 45 years ago in Peru and in the Himalayas clearly demonstrate hemolysis on descent from high altitude. There is a 10% decline in red cell mass in the first several days at sea level, an increase in serum bilirubin and stool urobilin, all occurring before there is any significant fall in red cell production. We preview studies on acclimated subjects descending from high altitude which will directly demonstrate neocytolysis by selectively labeling red cell cohorts of different ages. These studies will elucidate underlying mechanisms of neocytolysis, whether sub-threshold erythropoietin levels affect surface adhesion molecule expression and red cell-phagocyte interactions. Neocytolysis may have broad implications to clinical medicine, including to current dosing regimens of erythropoietin
Oxygen sensing in the orchestration of hyрохіс mеtаbolic arrest
No full textThe metabolic and molecular basis of oxygen sensing has been probed using isolated hepatocytes from the vertebrate facultative anaerobe, the western painted turtle. As part of a coordinated systemic response to hypoxia, these cells actively suppress ATP synthesis in synchrony with ATP demand from all major energy sinks (Na+/K+ ATPase, Ca2+ ATPase, protein turnover, urea synthesis, glucose release and gluconeogenesis). The result is a 10-fold suppression in metabolic rate superimposed over a re-partitioning of ATP- demand among cellular processes. This oxygen-dependent metabolic re-organization is tightly controlled, being rapid in onset, occurs without perturbation to adenylate concentrations. or membrane potential, it involves the oxygen-dependent suppression and expression of specific genes and it sustains a new, lower rate of flux through specific biochemical pathways. until re-oxygenation. The net effect dramatically spares fermentable substrate, limits rates of metabolic waste accumulation and profoundly extends survival time in anoxia. Direct roles for oxygen-receptive mechanisms in the control of flux rates have been explored for two energetically significant cellular events during the onset of hypoxic metabolic suppression. Protein turnover, the most energetically eostly cell process in norrnoxia, exhibited oxygen-dependent modulation of specific protein bands whose expression could be predictably manipulated by Co2+, Ni2+, and Co. This supports a role for heme-protein based oxygen receptor mechanism in the control of hypoxic gene expression on entering metabolic arrest. Secondly, noninvasive studies using a Ca2+-selective selfreferencing electrode demonstrate that ther is a 75% suppression in transmembrane Ca2+-flux that is oxygen conforming, exhibiting an apparent KmO2 of 145µM. The suppression of Ca2+-flux was protein kinase-c dependent, and was not repeatable under aerobic inhibition of electron transfer be KCN. These results suggest that the hypoxic response of different cellullar processes coalesce to form a coordinated metabolic and molecular re-orchestration of cell function that enables longterm survival without oxygen. Integral to this is the clear potential for oxygen-receptive mechanisms to signal, and coordinate, flux changes through complex, energetically expensive pathways.
Women at altitude: Blood vessels
No full textThe physiological response of women to altitude has received comparatively little study until recently. Of interest is whether women and men differ in their physiological response to high altitude and if so, whether differences are due to circulating ovarian or gonadal hormones or to gender differences unrelated to levels of circulating hormones. It is important to recall that the determination of gender involves considerable evolutionary, genetic and developmental complexity. Studies of acute and chronic response to high altitude provide are useful for examining the general mechanisms and evolutionary significance of the influences of gender and sex hormones on processes of oxygen transport. The period of pregnancy and fetal development is subject to greater mortality risk than any other period during the life cycle. At high altitude, fertility is maintained at or above sea level values but infant birth weight decreases an average of 100 gm per 1000 m altitude gain, principally as a result of fetal growth retardation. An increased frequency of maternal complications of pregnancy also has been reported at high altitude and may, in turn, contribute to the birth weight decline. Pregnancy stimulates several components of maternal O₂ transport, raising ventilation and arterial oxygenation as the result of the combined actions of ovarian hormones and increased mletabolic rate. The magnitude of the rise in maternal ventilation and arterial oxygenation relates to infant birth weight at high altitude. Uteroplacental blood flow also appears to be reduced at high altitude, particularly among women developing preeclampsia. Thus the maternal ventilatory and cardiovascular adjustments by which fetal-placental O2 and other nutrient delivery is maintained may be crucial in attaining successful adaptation to high altitude
Antiinflammatory effect of high-altitude adaptation in patients with bronchial asthma.
No full textDuring some years we have already elaborated the method of high-altitude climatotherapy (HACT) in patients with bronchial asthma (BA) (on the Tuya-Ashu Pass, Northern Tien-Shan, 3.200 m. above the sea level). Complex bronchologic study including brochoalveolar lavage (BAL) was performed in 62 patients with BA before treatment (in Bishkek , 760 m above the sea level) and on the 25th day of HACT BAL study included: cytologic composition, estimation of the viability and phagocytic activity of alveolar macrophages (AM) with latex particles, immunoglobulinFc- and complement C3 - fraction receptorson AM membrane, assessment of secretory IgA (SIgA) and surface activity (SA) of surfactant. We found that the treatment of patients with BA at high-altitude to improve a number of parameters of BAL demonstrating the antiinflammatory effect of high-altitude climatotherapy.  
Aclimatación y adaptación a las grandes alturas
No full textEn la presente revisión se describen los conceptos de aclimatación y adaptación a la altura. Se enumeran las distintas ciudades de Perú y de La Paz ubicados a diferentes alturas con el fin de precisar la presión parcial de oxígeno en la atmósfera, en el aire inspirado, y la presión barométrica en cada una de ellas. Se describen los fenómenos de ventilación y saturación arterial de oxígeno ante la exposición aguda a la altura, observándose un incremento de la ventilación y disminu ción de la saturación arterial de oxígeno. Se definen los tipos de ajuste durante la exposición aguda a la altura: acomodación, aclimatación y adaptación; así como, el mal de montaña agudo y el mal de montaña crónico
Barreras culturales y desafíos bioéticos en el manejo del pie diabético: una reflexión desde la realidad peruana
Get PDFCibercondría relacionada a dengue en un área endémica peruana: análisis exploratorio de características demográficas y trastornos de salud mental en estudiantes de Medicina Humana
Get PDFCyberchondria has intensified in contexts of infectious outbreaks, such as COVID-19, and may be influenced by local factors such as the endemicity of dengue in certain regions of Peru. Objective: To explore dengue-related cyberchondria among medical students in a dengue-endemic area in northern Peru. Materials and methods: A cross-sectional study was conducted at the National University of Piura, using self-reported questionnaires such as the Cyberchondria Severity Scale (CSS-12) and the Depression, Anxiety, and Stress Scale (DASS-21). Students without informed consent or with a recent diagnosis of dengue were excluded. Results: In a total sample of 192 participants, the average cyberchondria severity score was 27.7 ± 7.2. Significant variables included rural origin (p=0.029), being in the middle cycles of the course (p=0.001), and high levels of anxiety (p<0.001) and stress (p=0.030) according to the DASS-21. Multivariate analyses revealed that anxiety is a significant predictor of the severity of cyberchondria. Conclusion: Anxiety is a significant predictor of the severity of cyberchondria in medical students living in dengue-endemic areas.La cibercondría se ha agudizado en contextos de brotes infecciosos, como la COVID-19, y podría estar influenciada por factores locales como la endemicidad del dengue en ciertas regiones del Perú. Objetivo: Explorar la cibercondría relacionada al dengue en estudiantes de Medicina de una zona endémica del norte del Perú. Materiales y métodos: Se realizó un estudio transversal en la Universidad Nacional de Piura utilizando cuestionarios autoinformados: Escala de Severidad de Cibercondría (CSS-12) y Escala de Depresión, Ansiedad y Estrés (DASS-21). Se excluyeron estudiantes que no hayan brindado su consentimiento informado o con diagnóstico reciente de dengue. Resultados: En una muestra total de 192 participantes, la media de severidad de cibercondría fue de 27,7 ± 7,2. Variables significativas incluyeron procedencia rural (p = 0,029), pertenecer a ciclos medios de la carrera (p = 0,001), y tener altos niveles de ansiedad (p < 0,001) y estrés (p = 0,030) según la DASS-21. Los análisis multivariados revelaron que la ansiedad es un predictor significativo de la severidad de la cibercondría. Conclusión: La ansiedad es un significativo factor predictivo de severidad de cibercondría en estudiantes de Medicina que viven en zonas endémicas de dengue
Competencias digitales en docentes universitarios
Get PDFDigital competence in teachers are skills, knowledge and attitudes required for the use of technologies in the creation, management and development of information and knowledge for the achievement of student learning. The objective of the study was to determine the digital competence of teachers at a Peruvian university. Method: The study was observational and cross-sectional, and the “Digital Competence for Educators” self-assessment survey was applied to a sample of 365 teachers. Descriptive and inferential statistics were used to identify associations with some variables of interest. Results: Teachers achieved the digital competence of Integrator. Discussion: It is necessary to improve competencies by providing training on various technological tools and analyzing their adaptation to current teaching practices. Conclusions: The evaluated teachers have digital competence at an integrative level.La competencia digital en los docentes son habilidades, conocimientos y actitudes requeridos para el uso de las tecnologías en la creación, gestión y desarrollo de información y conocimiento para el logro de aprendizaje de los estudiantes. El objetivo del estudio fue determinar la competencia digital de los docentes de una universidad peruana. Método: El estudio fue observacional de corte transversal, se aplicó la encuesta de autoevaluación de “Competencia Digital para Educadores” a una muestra de 365 docentes. Se usó estadística descriptiva e inferencial para identificar asociación con algunas variables de interés. Resultados: Los docentes alcanzaron la competencia digital de Integrador. Discusión: Es necesario mejorar las competencias brindar capacitación sobre diversas herramientas tecnológicas y analizar su adaptación a las prácticas de enseñanza actuales. Conclusiones: Los docentes tienen una tendencia favorable sobre las competencias digitales