Yin-Yang-1 decreases Fas-induced apoptosis in acute lymphoblastic leukemia under hypoxic conditions: its implications in immune evasion / YY1 induce la disminución de la apoptosis a través de Fas en la leucemia linfoblástica aguda en condiciones hipóxicas: implicaciones en la evasión de la respuesta inmunitaria

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive malignant disease with high prevalence in pediatric patients. It has been shown that the downregulation of Fas expression is correlated with an inadequate response in ALL, although these mechanisms are still not well understood. Several reports demonstrated that hypoxia is involved in dysfunctional apoptosis. Yin-Yang-1 (YY1) transcription factor is involved in resistance to apoptosis, tumor progression, and it is increased in different types of cancer, including leukemia. The regulatory mechanism underlying YY1 expression in leukemia is still not understood, but it is known that YY1 negatively regulates Fas expression. The study aimed to evaluate the effect of YY1 on Fas expression under hypoxic conditions in ALL. Methods: Leukemia cell line RS4; 11 was cultured under normoxic and hypoxic conditions. YY1, Fas receptor, and hypoxia-inducible factor (HIF-1α) expression were analyzed. After treatment with a Fas agonist (DX2), apoptosis was analyzed through the detection of active caspase 3. Data were analyzed using Pearson’s correlation. Results: Leukemia cells co-expressed both HIF-1α and YY1 under hypoxia, which correlated with a downregulation of Fas expression. During hypoxia, the levels of apoptosis diminished after DX2 treatment. The analysis revealed that patients with high levels of HIF-1α also express high levels of YY1 and low levels of Fas. Conclusions: These results suggest that YY1 negatively regulates the expression of the Fas receptor, which could be involved in the escape of leukemic cells from the immune response contributing to the ALL pathogenesis.

Resumen Introducción: La leucemia linfoblástica aguda (LLA) es una enfermedad con alta prevalencia en la población pediátrica. El mecanismo por el cual el receptor de Fas participa en la regulación inmunitaria en los tumores es desconocido, pero se sabe que está subexpresado en LLA. El factor de transcripción Ying-Yang-1 (YY1) está involucrado en la resistencia a la apoptosis y la progresión tumoral; se encuentra aumentado en diferentes tumores, incluida la LLA. Aunque los mecanismos que regulan la expresión de YY1 en LLA son desconocidos, se sabe que YY1 regula la expresión del receptor de Fas. El objetivo de este trabajo fue evaluar el efecto de YY1 en la expresión de Fas en condiciones de hipoxia en la LLA. Métodos: Se cultivaron células RS4;11 en condiciones de hipoxia y se analizó la expresión de YY1, receptor de Fas y HIF-1α. La apoptosis fue inducida usando un agonista de Fas (DX2) y se analizó con la detección de caspasa 3 activa. Los datos se analizaron mediante correlación de Pearson. Resultados: Las células RS4;11 coexpresaron HIF-1αy YY1 en hipoxia, lo cual correlaciona con una baja expresión de Fas. La apoptosis se encontró disminuida durante condiciones de hipoxia, después del tratamiento con DX2. El análisis bioinformático mostró que los pacientes con altos niveles de HIF-1αpresentan YY1 elevado y bajos niveles del receptor de Fas. Conclusiones: Estos resultados sugieren que YY1 regula negativamente la expresión del receptor de Fas, lo cual podría estar involucrado en el escape de las células leucémicas a la respuesta inmunitaria, contribuyendo a la patogénesis de la LLA.

Polydatin protects H9c2 cells from hypoxia-induced injury via up-regulating long non-coding RNA DGCR5

Polydatin (PD), a monocrystalline polyphenolic drug mainly found in the roots of Polygonum cuspidatum, has various pharmacological activities. Long non-coding RNAs (lncRNA) DiGeorge syndrome critical region gene 5 (DGCR5) was found to participate in the suppression of multiple cancers. Here, we proposed to study the effect of PD on myocardial infarction (MI) by inducing DGCR5. CCK-8 assay was performed to detect the viability of H9c2 cells. Flow cytometry was utilized to test apoptosis of H9c2 cells. These results determined the optimal concentration and effect time of hypoxia as well as PD. Si-DGCR5 was transfected into cells and the expression level was determined by qRT-PCR. Western blot was utilized to evaluate the expression of apoptosis-related proteins, Bcl-2, Bax, and cleaved-caspase-3, as well as autophagy-associated proteins including Beclin-1, p62, and LC3-II/LC3-I. As a result, PD efficiently attenuated hypoxia-induced apoptosis and autophagy in H9c2 cells. The expression of DGCR5 was down-regulated by hypoxia and up-regulated by PD. Besides, knocking-down the expression of DGCR5 inhibited the protection of PD in H9c2 cells. In addition, PD up-regulated the accumulation of DGCR5, DGCR5 decreased the expression of Bcl-2 and p62, raised the expression of Bax and cleaved-caspase-3, and the proportion of LC3-II/LC3-I. PD stimulated the PI3K/AKT/mTOR and MEK/ERK signaling pathways via up-regulating the expression of DGCR5. Our data demonstrated that PD reduced cell apoptosis and autophagy induced by hypoxia in cardiomyocytes. Moreover, PD activated PI3K/AKT/mTOR and MEK/ERK signaling pathways by up-regulating the expression of DGCR5.

Emodin protects H9c2 cells from hypoxia-induced injury by up-regulating miR-138 expression

Myocardial infarction (MI) is a common presentation for ischemic heart disease, which is a leading cause of death. Emodin is a Chinese herbal anthraquinone used in several diseases. However, the effect of emodin in hypoxia-induced injury in cardiomyocytes has not been clearly elucidated. Our study aimed to clarify the functions of emodin in hypoxia-induced injury in rat cardiomyocytes H9c2 and explore the underlying mechanism. The effects of emodin on cell viability and apoptosis were analyzed by the Cell counting kit-8 assay and flow cytometry assay, respectively. The cell proliferation- and cell apoptosis-related proteins were detected by western blot. qRT-PCR was used to determine the relative expression of miR-138. Cell transfection was performed to alter miR-138 and MLK3 expression. miR-138 target was performed by dual luciferase activity assay. Sirt1/AKT and Wnt/β-catenin pathways-related factors phosphorylation were analyzed by western blot. Emodin inhibited hypoxia-induced injury in H9c2 cells by promoting cell viability and reducing cell apoptosis. miR-138 was down-regulated by hypoxia treatment but up-regulated by emodin. Up-regulation of miR-138 alleviated hypoxia-induced cell injury. Down-regulation of miR-138 attenuated the growth-promoting effect of emodin on hypoxia-induced injury, whereas up-regulation of miR-138 enhanced the growth-promoting effects of emodin. The underlying mechanism might be by inactivating Sirt1/AKT and Wnt/β-catenin pathways. MLK3 was negatively regulated by miR-138 expression and inactivated Sirt1/AKT and Wnt/β-catenin pathways. Emodin alleviated hypoxia-induced injury in H9c2 cells via up-regulation of miR-138 modulated by MLK3, as well as by activating Sirt1/AKT and Wnt/β-catenin pathways.

CoCl2 simulated hypoxia induce cell proliferation and alter the expression pattern of hypoxia associated genes involved in angiogenesis and apoptosis

BACKGROUND/AIMS: Hypoxia microenvironment plays a crucial role during tumor progression and it tends to exhibit poor prognosis and make resistant to various conventional therapies. HIF-1α acts as an important transcriptional regulator directly or indirectly associated with genes involved in cell proliferation, angiogenesis, apoptosis and energy metabolism during tumor progression in hypoxic microenvironment. This study was aimed to investigate the expression pattern of the hypoxia associated genes and their association during breast cancer progression under hypoxic microenvironment in breast cancer cells. METHODS: Cell proliferation in MCF-7 and MDA-MB-231 cell lines treated with different concentration of CoCl2 was analyzed by MTT assay. Flow cytometry was performed to check cell cycle distribution, whereas cell morphology was examined by phase contrast microscopy in both the cells during hypoxia induction. Expression of hypoxia associated genes HIF-1α, VEGF, p53 and BAX were determined by semiquantitative RT-PCR and real-time PCR. Western blotting was performed to detect the expression at protein level. RESULTS: Our study revealed that cell proliferation in CoCl2 treated breast cancer cells were concentration dependent and varies with different cell types, further increase in CoCl2 concentration leads to apoptotic cell death. Further, accumulation of p53 protein in response to hypoxia as compare to normoxia showed that induction of p53 in breast cancer cells is HIF-1α dependent. HIF-1α dependent BAX expression during hypoxia revealed that after certain extent of hypoxia induction, over expression of BAX conquers the effect of anti-apoptotic proteins and ultimately leads to apoptosis in breast cancer cells. CONCLUSION: In conclusion our results clearly indicate that CoCl2 simulated hypoxia induce the accumulation of HIF-1α protein and alter the expression of hypoxia associated genes involved in angiogenesis and apoptosis.

Cambios morfofisiológicos celulares durante la reanimación cardiopulmocerebral / Morph-physiological cellular changes during cardiac-pulmonary-cerebral resuscitation

Las células realizan transformaciones estructurales y metabólicas ante situaciones de estrés, lo que les permite mantener una adecuada homeostasis y evitar la muerte. La presente revisión bibliográfica tuvo como objetivo describir los principales cambios morfofisiológicos celulares que acontecen en la parada cardiaca y reanimación cardiopulmocerebral. El método incluyó una revisión documental (bases de datos SciELO Regional, PubMed, Cochrane e Infomed), realizada durante el primer semestre del 2018. Fueron seleccionadas 28 referencias. Se concluye que existen cambios celulares durante el cese circulatorio, las maniobras de resucitación y en la reperfusión. En la parada cardiaca, los cambios celulares se expresan en todos los organelos y puede llevar a muerte por necrosis. Durante la reperfusión se producen nuevos cambios estructurales, por entrada de calcio, alteraciones en sodio, producción de radicales libres e inflamación. Los cambios morfofisiológicos dependerán del estado metabólico previo, el tiempo de parada cardiaca y la instauración eficaz de medidas de resucitación.

Cell suffer structural and metabolic changes in stress situations,which allow them to maintain an adequate homeostasis and avoid death . This bibliographic review had the objective of describing the main morph-physiological changes which occur in cardiac failure and cardiac-pulmonary-cerebral resuscitation. The method was documentary reviewing (database Regional SciELO, PubMed, Cochrane and Infomed), developed during the first semester of 2018. Twenty eight references were selected. It was concluded that there are cellular changes during circulatory stop, the procedures of resuscitation and re-perfusion. In cardiac failure, cellular changes are expressed in all the organelles. And may cause death due to necroses. During re-perfusion new structural changes occur, for calcium entrance, sodium disturbances, production of free radicals and swelling. Morph.physiological changes depend on previous metabolic condition, time of cardiac failure and the successful establishment of resuscitation measures.

Plasma Cellular Hypoxia, Mitochondrial Dysfunction, Disease Risk and Prognostic Factors in Type 2 Diabetic Patients in Saudi Arabia / Hipoxia celular plasmática, disfunción mitocondrial, riesgo de enfermedad y factores pronósticos en pacientes diabéticos tipo 2 en Arabia Saudita

ABSTRACT Objective: This cross-sectional study evaluated the association of plasma cytochrome c (CytoC) and hypoxia-inducible factor (HIF)-1α, as mitochondrial dysfunction and cellular hypoxia biomarkers, with disease risk factors and prognosis in Type 2 diabetic patients in Saudi Arabia. Methods: A total of 252 patients (94 males and 158 females) were eligible and were matched by socio-economic status, age and body mass index (BMI) with 106 healthy participants (71 males and 35 females). They were subgrouped according to BMI, disease duration and treatment. Lipid and glycaemic control indices were colorimetrically measured to calculate insulin resistance (IR) and atherogenic index of plasma (AIP). Haemoglobin A1c, C-reactive protein (CRP), CytoC and HIF-1α were measured using specific immunoassays. Results: Among the patients, 50% (38.64% of males and 52.53% of females), 40.48% (43.18% of males and 40.51% of females), 4.365% (6.82% of males and 3.80% of females), 2.381% (4.55% of males and 1.90% of females), and ~0.8% (males) suffered from peripheral neuropathy, ophthalmopathy, kidney disease, myocardial infarction and ketoacidosis, respectively. The majority of complicated cases had greater age, BMI, disease duration, plasma insulin and AIP, and were on insulin. The two investigated groups were non-significantly different considering CytoC, but highly significantly different considering lipid profile (as reflected on AIP) and glycaemic control parameters (as reflected on IR, plasma CRP and HIF-1α), with significant correlations among all of them in a group-specific pattern. Conclusion: Patients suffered a high rate of complications that correlated with age, BMI, disease duration, AIP, plasma insulin and insulin treatment due to poor disease control. Reduced HIF-1α and non-significant increased CytoC levels correlated negatively with bad prognostic indicators of the disease pointing to a pathogenetic implication.

RESUMEN Objetivo: Este estudio transversal evaluó la asociación del citocromo C del plasma (CitoC) y el factor inducible por hipoxia (HIF)-1α, como la disfunción mitocondrial y los biomarcadores de la hipoxia celular, con los factores de riesgo y pronóstico de enfermedad en pacientes diabéticos de tipo 2 en Arabia Saudita. Métodos: Un total de 252 pacientes (94 varones y 158 mujeres) fueron elegidos y apareados por estado socioeconómico, edad e índice de masa corporal (IMC) con 106 participantes sanos (71 varones y 35 hembras). Se dividieron entonces en subgrupos de acuerdo con el IMC, la duración de la enfermedad y el tratamiento. Se midieron los índices de lípidos y control glucémico para calcular la resistencia a la insulina (RI) y el índice aterogénico de plasma (IAP). la hemoglobina A1C, la proteína C-reactiva (PCR), CitoC y HIF-α fueron medidos usando inmunoensayos específicos. Resultados: Entre los pacientes, el 50% (38.64% de los varones y el 52.53% de las mujeres), 40.48% (43.18% de los varones y 40.51% de las mujeres), 4.365% (6.82% de los varones y 3.80% de las mujeres), 2.381% (4.55% de los varones y 1.90% de las mujeres), y ~ 0.8% (varones) padecían de neuropatía periférica, oftalmopatía, enfermedad renal, infarto de miocardio y cetoacidosis, respectivamente. la mayor parte de los casos complicados tenían mayor edad, IMC, duración de la enfermedad, insulina plasmática e IAP, y recibían tratamiento de insulina. Los dos grupos investigados no fueron significativamente diferentes considerando la CitoC, pero fueron muy significativamente diferentes en cuanto a su perfil lipídico (como se refleja en el IAP) y los parámetros de control glicémico (como se refleja en la RI, el plasma y el HIF-α), con importantes correlaciones entre todos ellos en un patrón específico de grupo. Conclusión: Los pacientes tuvieron un alto índice de complicaciones que se correlacionaron con la edad, el IMC, la duración de la enfermedad, el IAP, la insulina plasmática y el tratamiento de la insulina debido al pobre control de la enfermedad. La reducción del HIF-α y el aumento no significativo de los niveles de CitoC se correlacionaron negativamente con los indicadores de mal pronóstico de la enfermedad, que apuntaban a una implicación patogénica.

IL-10 and TGF-ß1 evaluation in 3D human adipose-derived mesenchymal stem cells culture and hypoxic condition / Avaliação de IL-10 e TGF- ß 1 sob condições de hipóxia em cultivo celular 3D de células-tronco mesenquimais de tecido-adiposo humano

Mesenchymal stem cells (MSC) are multipotent cells derived from layer mesoderm and that have potential for self-renewal and cellular differentiation. These cells can be extracted from various tissues, being the main sources the bone marrow (BM) and adipose tissue (AT). Therefore, human Adipose-derived Mesenchymal Stem Cells (AdMSCs) are potentially able to differentiate in several cell types such as neurons, adipocytes and osteoblasts. The objective of this work was to quantify levels of the cytokines TGF-1 and IL-10 in the conditioned medium (CM) of AdMSCs c u l t i v a t e d in 2D and 3D culture after the induction of hypoxia by Cobalt chloride chemistry (CoCl2). When the AdMSCs reached 80% of confluence, the cells were transferred to t h e 24 plates wells, where they were treated with CoCl2 in 2D and 3D culture. Quantification assay was made using human TGF-1 and IL- 10 kits. The analysis was done through the sandwich ELISA assay. The IL-10 and TGF-1 production have increased when the AdMSCs were in three-dimensional culture and under hypoxic conditions, indicating that supplies of oxygen associated to the 3D culture influenced significantly the production of these cytokines. This can be a potent and low-cost strategy to improve Adipose-derived Stem Cells conditioned medium when it comes to the release of IL-10 and TGF- cytokines.

Células-tronco mesenquimais (CTMs) são células multipontes derivadas da camada mesoderma e que possuem potenciais de auto-renovação e diferenciação celular. Estas células podem ser extraídas de diversos tecidos, sendo as principais fontes a medula óssea (MO) e o tecido adiposo (TA). Assim, CTM-TA são potencialmente capazes de se diferenciarem em diversos tipos celulares como adipócitos, neurônios e osteoblastos através de ações parácrinas do microambiente de cultivo. Este trabalho teve como objetivo dosar os níveis das citocinas TGF- e IL-10 no meio condicionado de CTM-TA cultivadas em 2D e 3D após a indução de hipóxia química por Cloreto de Cobalto (CoCl2). As CTM-TA foram cultivadas até atingirem a confluência de 80% e em seguida foram transferidas para placas de 24 poços, onde foram tratadas com meio indutor de hipóxia em cultivos realizados em 2D e 3D. A quantificação foi realizada utilizando os kits TGF-1 e IL10 humanos. Nas análises foi utilizado o ensaio ELISA sanduíche. Os resultados mostraram que a produção de citocinas IL10 e TGF- aumentaram quando o cultivo celular foi tridimensional em condições de hipóxia, indicando que os fornecimentos de oxigênio associado ao cultivo em 3D influenciaram de maneira significativa na produção de tais citocinas. Esta pode ser uma estratégia potente e de baixo custo para aumentar a liberação TGF- e IL- 10 no meio condicionado de CTM-TA.

Effect of varying hypoxia reoxygenation times on autophagy of cardiomyocytes

Abstract Purpose: To investigate the impact of different hypoxia reoxygenation (HR) times on autophagy of rat cardiomyocytes (H9C2). Methods: Rat cardiomyocytes were randomly divided into normal control group (group A), hypoxia group (group B), 2 h HR group (group C), 12 h HR group (group D), and 24 h HR group (group E). LC3 II/LC3 I was determined via western blotting, and cell viabilities of cardiomyocytes were measured using methyl thiazolyl tetrazolium (MTT) assay. Results: Cell viabilities in HR model groups were significantly lower than those of group A (P<0.05). LC3 II/LC3 I levels in groups B to D were significantly higher than those of group A (P<0.05), and group D showed the highest LC3 II/LC3 I levels. Cell viabilities in groups B to D were significantly lower than those of group A (P<0.05), with group D showing the lowest cell viabilities (P<0.05). Conclusions: Hypoxia can induce autophagy in rat cardiomyocytes, which can be further activated by reoxygenation; most notable after 12 h. Hypoxia-induced cell injury can be aggravated by reoxygenation. The lowest cell viability was observed at 12 h after reoxygenation; however, cell viability can be recovered after 24 h.

Andrographolide protects mouse astrocytes against hypoxia injury by promoting autophagy and S100B expression

Andrographolide (ANDRO) has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains) were subjected to 3 and 21% of O2 for various times (0-12 h) to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.

Hypoxia-induced hyperpermeability of rat glomerular endothelial cells involves HIF-2α mediated changes in the expression of occludin and ZO-1

This study aimed to investigate the role of hypoxia-inducible factor-2α (HIF-2α) in the expression of tight junction proteins and permeability alterations in rat glomerular endothelial cells (rGENCs) under hypoxia conditions. The expression level of HIF-2α and tight junction proteins (occludin and ZO-1) in rGENCs were examined following 5% oxygen density exposure at different treatment times. HIF-2α lentivirus transfection was used to knockdown HIF-2α expression. Cells were divided into four groups: 1) control group (rGENCs were cultured under normal oxygen conditions), 2) hypoxia group (rGENCs were cultured under hypoxic conditions), 3) negative control group (rGENCs were infected with HIF-2α lentivirus negative control vectors and cultured under hypoxic conditions), and 4) Len group (rGENCs were transfected with HIF-2α lentivirus and cultured under hypoxic conditions). The hypoxia, negative control, and Len groups were kept in a hypoxic chamber (5% O2, 5% CO2, and 90% N2) for 24 h and the total content of occludin and ZO-1, and the permeability of rGENCs were assessed. With increasing hypoxia time, the expression of HIF-2α gradually increased, while the expression of occludin decreased, with a significant difference between groups. ZO-1 expression gradually decreased under hypoxia conditions, but the difference between the 24 and 48 h groups was not significant. The permeability of cells increased following 24-h exposure to hypoxia compared to the control group (P<0.01). The knockdown of HIF-2α expression significantly increased occludin and ZO-1 content compared with hypoxia and negative control groups (P<0.01), while permeability was reduced (P<0.01). Hypoxia increased HIF-2α content, inducing permeability of rGENCs through the reduced expression of occludin and ZO-1.

Autofagia, una estrategia de supervivencia celular / Autophagy. A strategy for cell survival

La autofagia es un proceso de reciclado de partes de la célula. Como se describe en esta revisión, ocurre naturalmente preservando a las células de la acumulación de toxinas, moléculas y organelas dañadas y además permite los procesos de desarrollo y diferenciación de los tejidos. En el transcurso de la autofagia, el procesamiento de los sustratos a reciclar genera ATP, lo que constituye una fuente alternativa de energía en situaciones de estrés. En este sentido, bajo condiciones hostiles como hipoxia o falta de nutrientes, el proceso puede dispararse de modo exacerbado llevando a la muerte celular. Algunas alteraciones en su funcionamiento pueden involucrar el desarrollo de diversas patologías, tales como el daño hepático, el cáncer y las enfermedades neurodegenerativas.

Autophagy is a process of recycling parts of the cell. As described in this review, it occurs naturally in order to preserve cells from the accumulation of toxins, damaged molecules and organelles, and to allow processes of tissue development and differentiation. In the course of autophagy, the processing of the substrates to be recycled generates ATP, thus providing an alternative source of energy in stress situations. In this sense, under hostile conditions such as hypoxia or lack of nutrients, the autophagy process can be exacerbated leading to cell death. Some alterations in its functioning may involve the development of various pathologies, including liver damage, cancer and neurodegenerative diseases.

Influencia de la presión de oxígeno ambiental sobre la regeneración ósea guiada / Influence of ambient oxygen pressure on guided bone regeration

RESUMEN: Objetivo: Evaluar la influencia de la variación en la presión de oxígeno ambiental sobre la regeneración ósea guiada en cobayos. Material y método: Treinta y dos cobayos machos de 750±50g de peso fueron asignados en 2 grupos de 16 integrantes cada uno (grupo A: trabajado a 150msnm en la ciudad de Lima y a presión de oxígeno de 157mmHg; grupo B: trabajado a 3.230msnm en la ciudad de Jauja y a presión de oxígeno de 107mmHg). En ambos grupos se indujeron defectos óseos mandibulares de 5×6mm a través de un acceso quirúrgico extraoral; a 8 cobayos de cada grupo se les recubrió el defecto con una membrana de colágeno reabsorbible de origen porcino, mas al resto de animales no. Se evaluó el conteo celular de osteoblastos y osteocitos a los 15 y 30 días postoperatoriamente. Resultados: A los 15 y a los 30 días, en los grupos trabajados en altura y en los que se aplicó la membrana, la cantidad de osteoblastos fue 71±12,1 cél/camp y 83±7,2 cél/camp respectivamente, y la de osteocitos fue 34,5±6,6 cél/camp y 25±7,6 respectivamente; siendo estos grupos, en todas las comparaciones, los que tuvieron mayor cantidad de células óseas, aunque sin ser diferencias estadísticamente significativas (p>0,05). Conclusión: Se encontró tendencia a formar mayor cantidad de células óseas en las muestras tratadas con regeneración ósea y expuestas a la altitud comparados con el nivel del mar.

ABSTRACT: Objective: To evaluate the influence of the variation in ambient oxygen pressure on guided bone regeneration in guinea pigs. Material and method: A total of 32 male guinea pigs weighing 750±50g were assigned into two groups of 16 (group A: studied at 150 metres above sea level in the city of Lima and oxygen pressure of 157mmHg; group B: was at 3230 meters above sea level in the city of Jauja and an oxygen pressure of 107mmHg). Bone defects of 5×6mm were induced in the jaw in both groups through extra-oral surgical access. The defect in 8 guinea pigs of each group were covered with a porcine resorbable collagen membrane, but not in the other animals. The osteoblast and osteocyte cell counts were evaluated at 15 and 30 days post-operatively. Results: At 15 and 30 days, in the groups studied at height and with the membrane applied, the osteoblast count was 71±12.1 cells/field, and 83±7.2 cells/field, respectively, and an osteocyte count of 34.5±6.6 cells/field, and 25±7.6 cells/field, respectively. These groups had a higher number of bone cells in all the comparisons, but there were no statistically significant differences (P>.05). Conclusion: There was a tendency to form a greater amount of bone cells was found in the samples treated with bone regeneration and exposed to altitude compared to those at sea level.

Neonatal necrotizing enterocolitis rat model attenuated by a remote ischemic preconditioning in the pregnant

Abstract Purpose: To evaluate the effect of remote ischemic preconditioning (r-IPC) administered to pregnant rats, in the ileum of newborn rats subjected to hypoxia and reoxygenation. Methods: We used three pregnant rats and their newborn rats distributed in three groups: 1) Control (C) - Newborn rats born from a pregnant rat which did not undergo any intervention; 2) Hypoxia-Reoxygenation (H/R) - Newborn rats born from a pregnant rat which did not undergo any intervention, and were subjected to hypoxia-reoxygenation; 3) Remote Ischemic Preconditioning (r-IPC) - newborn rats born from a pregnant rat which was subjected to remote ischemic preconditioning twenty-four hours before giving birth and the newborn rats were subjected to hypoxia-reoxygenation. Segments of ileum were prepared for histological analysis by HE and immunohistochemistry by the Ki67 to evaluate cell proliferation, crypt depth and villus height and evaluation of apoptosis by cleaved caspase-3. Results: The intensity of the lesions was lower in the r-IPC than in the H/R group, showing significant difference (p<0.01). The r-IPC group showed a higher proliferative activity compared to the H/R group (p<0.01), with deeper crypts (r-IPC > H/R - p < 0.05), and higher villi, showing significant difference (r-IPC > H/R - (p <0.01). The occurrence of apoptosis in the H/R group was lower in comparison to groups C and r-IPC, with significant difference (H/R < r-IPC; p<0.05). Conclusion: The remote ischemic preconditioning applied to the pregnant rat protected the ileum of newborn rats subjected to hypoxia and reoxygenation, with decreased intensity of the lesions in the ileum mucosa and preservation of proliferative activity, keeping the villus height and crypt depth similar to group C.

Aged garlic extract and S-allylcysteine prevent apoptotic cell death in a chemical hypoxia model

BACKGROUND: Aged garlic extract (AGE) and its main constituent S-allylcysteine (SAC) are natural antioxidants with protective effects against cerebral ischemia or cancer, events that involve hypoxia stress. Cobalt chloride (CoCl2) has been used to mimic hypoxic conditions through the stabilization of the α subunit of hypoxia inducible factor (HIF-1α) and up-regulation of HIF-1α-dependent genes as well as activation of hypoxic conditions such as reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and apoptosis. The present study was designed to assess the effect of AGE and SAC on the CoCl2-chemical hypoxia model in PC12 cells. RESULTS: We found that CoCl2 induced the stabilization of HIF-1α and its nuclear localization. CoCl2 produced ROS and apoptotic cell death that depended on hypoxia extent. The treatment with AGE and SAC decreased ROS and protected against CoCl2-induced apoptotic cell death which depended on the CoCl2 concentration and incubation time. SAC or AGE decreased the number of cells in the early and late stages of apoptosis. Interestingly, this protective effect was associated with attenuation in HIF-1α stabilization, activity not previously reported for AGE and SAC. CONCLUSIONS: Obtained results show that AGE and SAC decreased apoptotic CoCl2-induced cell death. This protection occurs by affecting the activity of HIF-1α and supports the use of these natural compounds as a therapeutic alternative for hypoxic conditions

Phenotypic plasticity associated to environmental hypoxia in the neotropical serrasalmid Piaractus mesopotamicus (Holmberg, 1887) (Characiformes: Serrasalmidae)

Muchos peces carácidos sudamericanos desarrollan protuberancias dérmicas reversibles en las mandíbulas para optimizar la respiración acuática superficial (RAS) durante la hipoxia. Actualmente, aspectos básicos de esta adaptación permanecen desconocidos, principalmente debido a la escasez de estudios experimentales. En experiencias de laboratorio, determinamos el tiempo necesario para el desarrollo y la reversión completos de estas estructuras en Piaractus mesopotamicus , y estudiamos comparativamente respuestas conductuales, morfológicas, y respiratorias en un gradiente de concentración de oxígeno disuelto (OD). Los cambios morfológicos durante la hipoxia consistieron en protuberancias dérmicas del labio inferior, el borde anterior del maxilar, y el borde distal de la válvula opercular, incrementando el número conocido de estructuras modificadas. Éstas se desarrollaron completamente en menos de 6 horas y se revirtieron en menos de 3 horas. La mayoría de los rasgos observados siguieron una curva de respuesta logística, con valores críticos entre 0,90 y 2,70 mgL-1 de OD. La frecuencia respiratoria y el desarrollo de la válvula opercular presentaron valores críticos similares ubicados por encima del nivel de tolerancia al OD, mientras que la RAS y las protuberancias dérmicas mandibulares presentaron críticos por debajo de dicho nivel. Estas observaciones apoyan la relación funcional existente entre estos grupos de rasgos conductuales y morfológicos. Este estudio demuestra que esta especie puede modificar reversiblemente porciones del sistema respiratorio para optimizar las respuestas a la hipoxia.

Many South American characid fishes develop reversible dermal protuberances in the jaws to optimize aquatic surface respiration (ASR) during hypoxia. To date, basic aspects of this adaptation remain unknown, mainly due to the scarcity of experimental studies. In laboratory experiments, we determined time necessary for the complete formation and reversion of these structures in Piaractus mesopotamicus , and studied comparatively behavioral, morphological, and respiratory responses along gradients of dissolved oxygen (DO) concentration. Morphological changes during hypoxia consisted in dermal protuberances of lower lip, anterior border of maxillary and distal border of opercular valve, increasing the known number of structures modified. These structures developed completely in less than 6 hours and reversed in less than 3 hours. Most of observed traits showed a logistic response curve with threshold DO values between 0.90 and 2.70 mgL-1. Respiratory frequency and opercular valve development showed similar threshold values above the level of tolerance of DO, whereas ASR and dermal protuberances of the jaws showed threshold values below this level. This observation supports the functional link between these groups of behavioral and morphological traits. This study demonstrates that this species is able to modify reversibly portions of the respiratory system to optimize responses to hypoxia.

Fontes de obtenção de medicamentos para tratamento de hipertensão arterial no Brasil: análise da Pesquisa Nacional de Saúde, 2013 / Sources for obtaining drugs for hypertension in Brazil: results from the National Health Survey, 2013

RESUMO: Objetivo: Analisar as diferenças sociodemográficas dos indivíduos adultos hipertensos, em relação às fontes de obtenção de medicamentos para tratar hipertensão arterial no Brasil. Métodos: Análise secundária dos dados oriundos da Pesquisa Nacional de Saúde, 2013; os desfechos considerados nas análises foram representados pelas fontes de obtenção de medicamentos para tratar a hipertensão arterial. Resultados: Foram entrevistados 10.017 indivíduos. A grande maioria dos hipertensos em uso de medicamentos (74,0%) utiliza uma fonte única de obtenção de medicamentos 7,3% (IC95% 6,4 - 8,4) referiu obter todos os medicamentos por meio dos planos de saúde privados; 22,7% (IC95% 21,0 - 24,4) em farmácias do sistema público de saúde; 21,8% (IC95% 20,2 - 23,4) no Programa Farmácia Popular do Brasil; e 29,5% (IC95% 27,7 - 31,4) exclusivamente pelas farmácias comerciais. A obtenção no sistema público de saúde como fonte única diminuiu com o avanço da idade, apresentou-se menor nas pessoas de cor da pele branca, diminuiu fortemente com o aumento da escolaridade e evidenciou-se menor entre os residentes na região Norte do país; no Programa Farmácia Popular do Brasil, a fonte única de obtenção também foi menor para as pessoas com maior escolaridade. A obtenção nas farmácias comerciais esteve associada positivamente com um perfil do sexo masculino, de maior escolaridade, de idade mais elevada, tendo declarado cor da pele branca. A ocorrência de mais de uma fonte de obtenção mostrou-se associada positivamente ao aumento da idade e inversamente ao aumento da escolaridade. Conclusões: Os resultados possibilitaram identificar diferentes estratégias para obtenção de medicamentos usados no tratamento da hipertensão, de modo a explicar como são obtidos os medicamentos no país e qual o impacto das políticas públicas nesse setor.

ABSTRACT: Objective: To analyze the sociodemographic differences among adults with hypertension regarding the sources for obtaining drugs for hypertension treatment in Brazil. Methods: This is a secondary analysis of data from the National Health Survey 2013; the outcomes considered for the analysis were the sources for obtaining drugs for treating high blood pressure. Results: The great majority (74%) of patients with hypertension taking drugs use a single source for obtaining them, 7.3% (95%CI 6.4 - 8.4) reported getting all the drugs through private health plans, 22.7% (95%CI 21.0 - 24.4) by pharmacies of the public health system, 21.8% (95%CI 20.2 - 23.4) by the Popular Pharmacy Program, and about one-third (29.5%; 95%CI 27.7 - 31.4) exclusively by commercial pharmacies. Having the public health system as the single source for obtaining the drugs was found to decrease with age, was lower in white people, decreased strongly with increase in education, and was lower for residents in the North region. Exclusive obtainment through the Popular Pharmacy Program was lower for people with higher education. Obtainment in commercial pharmacies was positively associated with being male, with higher education level, being older, and having white skin color. Obtainment using more than one source was positively associated with increasing age and inversely associated with higher education levels. Conclusions: The results allowed the identification of a trajectory of patients in obtaining drugs for the treatment of hypertension, aiming at explaining how the drugs are obtained and the impact of public policies in this sector in the country.

Contexto sociodemográfico de los homicidios en México D.F.: un análisis espacial / Sociodemographic context of homicide in Mexico City: a spatial analysis

OBJETIVO:Investigar el patrón de distribución espacial de la tasa de homicidios y su relación con las características sociodemográficas en las delegaciones de Benito Juárez, Coyoacán y Cuauhtémoc de la Ciudad de México en el año 2010. MÉTODOS: Estudio inferencial de corte transversal que usa métodos de análisis espacial para estudiar la asociación espacial de la tasa de homicidios y las características demográficas. La asociación espacial fue determinada a través del cociente de localización, análisis de regresión múltiple y el uso de la regresión geográficamente ponderada. RESULTADOS: Los homicidios muestran un patrón de localización heterogéneo con altas tasas en zonas con uso del suelo no residencial, con baja densidad de población y baja marginación. CONCLUSIONES: El uso de herramientas de análisis espacial son instrumentos poderosos para el diseño de políticas de seguridad pública preventiva y recreativa que busquen reducir la mortalidad por causas externas como homicidios.

OBJECTIVE:Investigate the spatial distribution pattern of the homicide rate and its relation to sociodemographic features in the Benito Juárez, Coyoacán, and Cuauhtémoc districts of Mexico City in 2010. METHODS: Inferential cross-sectional study that uses spatial analysis methods to study the spatial association of the homicide rate and demographic features. Spatial association was determined through the location quotient, multiple regression analysis, and the use of geographically weighted regression. RESULTS: Homicides show a heterogeneous location pattern with high rates in areas with non-residential land use, low population density, and low marginalization. CONCLUSIONS: Spatial analysis tools are powerful instruments for the design of prevention- and recreation-focused public safety policies that aim to reduce mortality from external causes such as homicides.

Relationships among the Y balance test, Berg Balance Scale, and lower limb strength in middle-aged and older females

Background: Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance. Objective: The purpose of this study was to investigate the ability of the Y Balance Test (YBT) and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS), and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females. Method: The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS. Results: The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor. Conclusions: Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance. .

Pré-condicionamento isquêmico remoto em portadores de claudicação intermitente de membros inferiores / Remote ischemic preconditioning in patients with intermittent claudication

INTRODUÇÃO: Pré-condicionamento isquêmico remoto (PCIR) é o fenômeno pelo qual curtos períodos de isquemia sub-letal sobre um órgão ou tecido, intercalados com reperfusão do mesmo, conferem a outros órgãos ou tecidos distantes deste, um aumento na capacidade da resistir a episódios subsequentes de isquemia, a qual os mesmos possam ser expostos. Com base nesse fato, testamos a hipótese de que o pré-condicionamento isquêmico remoto em pacientes portadores de claudicação intermitente de membros inferiores poderia aumentar a capacidade de deambulação desses pacientes, extrapolando o conceito do PCIR de aumento da capacidade de preservação da integridade celular frente à isquemia, para a manutenção da função celular, tornando a célula mais apta ao trabalho em situações de privação de oxigênio, geradas pela restrição do fluxo sanguíneo, como ocorre nos pacientes com claudicação intermitente de membros inferiores, durante o exercício. OBJETIVOS: Avaliar se o PCIR aumenta a distância de início de claudicação e/ou a distância total de claudicação em pacientes com doença arterial obstrutiva periférica. MÉTODOS: Foram estudados 52 pacientes ambulatoriais que apresentavam queixa de claudicação intermitente dos membros inferiores, associada a um pulso arterial ausente ou reduzido no membro sintomático e/ou um índice tornozelo-braço <0,90. Estes pacientes foram randomizados em três grupos (A, B e C). Todos os pacientes foram submetidos a dois testes de caminhada em esteira de acordo com o protocolo de Gardner. O grupo A fez o primeiro teste de esteira sem o pré-condicionamento isquêmico remoto e, após 7 dias, foi submetido a um novo teste de esteira, agora precedido pelo pré-condicionamento isquêmico remoto. O grupo B foi submetido ao pré-condicionamento isquêmico remoto antes do primeiro teste de esteira e, após 7 dias, realizou novo teste de esteira, agora sem o pré-condicionamento isquêmico remoto. Já no Grupo C (grupo controle), ambos os testes de esteira foram...

INTRODUCTION: Remote ischemic preconditioning (RIPC) is a phenomenon in which a short period of sub-lethal ischemia in one organ protects against subsequent bouts of ischemia in another organ. Extrapolating the RIPC concept of increasing the preservation of cell integrity capability against ischemia, for the maintenance of cellular function, making the cell more able to work in oxygen deprivation generated by the restriction of blood flow, as occurs in patients with intermittent claudication of the lower limbs during exercise, we hypothesized that RIPC in patients with intermittent claudication would increase muscle tissue resistance to ischemia, thereby resulting in an increased ability to walk. OBJECTIVES: To test this hypothesis, we performed gait tests in patients with claudication with and without prior RIPC and then compared the initial claudication distance (ICD) and the total walking distance (TWD). METHODS: In a claudication clinic, 52 ambulatory patients who presented with complaints of intermittent claudication in the lower limbs associated with an absent or reduced arterial pulse in the symptomatic limb and/or an ankle-brachial index < 0.90 were recruited for this study. The patients were randomly divided into three groups (A, B and C). All of the patients underwent two tests on a treadmill according to the Gardener protocol. Group A was tested first without RIPC. Group A was subjected to RIPC prior to the second treadmill test. Group B was subjected to RIPC prior to the first treadmill test and then was subjected to a treadmill test without RIPC. In Group C (control group), both treadmill tests were performed without RIPC. The first and second tests were conducted seven days apart. Brazilian Clinical Trials: RBR-7TF6TM. RESULTS: Group A and C showed an increase in the initial claudication distance in the second test compared to the first test. Group A had a statistically significant increase, compared with C group (control group). With respect...

Effects of maternal ischemic preconditioning in the colon of newborn rats submitted to hypoxia-reoxygenation insult

PURPOSE: To evaluate the effects of maternal remote ischemic preconditioning (IPCr) in the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation. METHODS: Newborn Wistar rats were divided into three groups. Control Group (CG), Hypoxia and Reoxygenation Group (HRG) and Remote Ischemic Preconditioning Group (IPCrG). Hypoxia and reoxygenation was performed 2x per day, with an interval of 6 hours, on the 1st, 2nd and 3rd days of life, with 10 minutes of CO2 at 100%, followed by 10 minutes O2 at 100%(HRG/IPCrG). The maternal IPCr was performed 24 hours before delivery by applying a rubber band tourniquet to the left hind limb (IPCrG). Segments of the colon underwent histological (HE) and immunohistochemical analysis for caspase-3 and COX - 2. RESULTS: The histological findings showed no intestinal mucosal damage in the CG group and severe lesions in HRG that was attenuated in the IPCrG (p<0.05). The expression of the apoptotic cells was lower in the HRG group than in the CG and IPCrG. The COX-2 expression was intense in HRG and attenuated in the IPCrG (p<0.05). CONCLUSIONS: Maternal IPCr protected the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation, reducing the morphological alterations and inflammatory response. It ameliorates the occurrence of apoptosis, keeping the physiological process of renewal and regeneration in the epithelial lining of the colonic mucosa. .