Numerical simulation of the aqueous humor flow in the eye drainage system; a healthy and pathological condition comparison.

The present work describes the motion of aqueous humor through the anterior chamber and the trabecular drainage system, considering several distributions of the collector channels. The 3D computational model, implemented into the open-source software, was reconstructed from an optical coherence tomography. The model has been employed to simulate the aqueous humor dynamics considering buoyancy effects. The presence of the anterior chamber, the trabecular meshwork, and the Schlemm's canal were taken into consideration with 14 different distributions of collector channels. The influence of collector channels position on the intraocular pressure and shear stress has been analyzed, for a healthy and a glaucomatous condition. Aqueous humor velocity, pressure, temperature, wall shear stress, skin friction coefficient and Nusselt number, are presented for the different cases. The results indicate that the position of the collector channels has a strong influence on the wall shear stress on the Schlemm's canal and collector channels.

Correlación entre el grado de hipertensión arterial y el índice de estrés oxidativo. Estudio de cohorte en una población de pacientes hipertensos sistémicos en República Dominicana / Correlation between the arterial hypertension degree and oxidative stress index. Cohort study in a population of systemic hypertensive patients in Dominican Republic

Introducción: la hipertensión arterial (HTA) es una de las mayores cargas de enfermedad y riesgo para infarto cardíaco, la insuficiencia cardíaca y el fallo renal. Se reconoce que el estrés oxidativo (EO) es un determinante en el desarrollo de complicaciones y el progreso de la HTA. Se determinó el índice de EO (IEO) en individuos con HTA y en un grupo sano control, para evaluar su posible correlación. Materiales y métodos: se midió IEO en una población de 112 individuos con HTA de distintos grados entre 50 y 70 años escogidos al azar y se comparó con los valores de un grupo control de voluntarios sanos, con la intención de definir el grado de correlación entre los niveles del IEO y la severidad de HTA, mediante la medición de biomarcadores para el EO en lisado de eritrocitos. Resultados: a pesar de que los beneficios de la terapia antioxidante (TAO) no han sido definitivamente probadas, en gran parte porque las enfermedades complejas no dependen de un solo componente fisiopatogénico, el EO sigue siendo una piedra angular en el desarrollo de complicaciones y el empeoramiento de los cuadros clínicos de muchos padecimientos. La demostración de biomarcardores específicos mejora la posibilidad de una TAO dirigida. El presente ensayo demostró que la edad, el género y la etnia no influyen en el IEO y que el EO fue severo en los casos de HTA iii, moderado en HTA ii y estuvo ausente en el subgrupo con HTA grado i. Conclusiones: estos resultados sugieren una relación entre los niveles de EO y severidad de HTA y sustenta evidencias para diseñar nuevos ensayos clínicos que evalúen la eficacia de una TAO adyuvante en el manejo de la HTA

Introduction: Arterial hypertension (AHT) is one of the major burdens of disease and risk for cardiac infarction, heart failure and renal failure. It is recognized that the oxidative stress (OS) is a determining factor in the development of complications and the progress of the AHT. OS Index (OSI) in individuals with AHT and a healthy control group, was determined to assess their possible correlation. Methods: OSI was measured in a population of 112 individuals with AHT of different levels between 50 and 70 years old, chosen at random and compared with the values of healthy volunteers control group with the aim of defining the degree of correlation between the levels of the OSI and the AHT severity, by measuring biomarkers for OS in a red cell lysate. Discussion: Despite the benefits of an antioxidant therapy (AOT) have not been definitely proven, largely because the complex diseases do not depend on a single pathophysiological component, OS remains as a cornerstone in the development of complications and the worsening of the clinical pictures of many ailments. The demonstration of specific biomarkers improve the possibility of an addressed AOT. This trial showed th at the age, gender and ethnicity do not influence the OSI and that OS was severe in HTA iii cases, moderate in HTA ii cases and was absent in the subgroup with HTA i. Conclusions: These results suggest a relationship between levels of EO and severity of hypertension and support evidence to design new clinical trials assessing the efficacy of an adjuvant AOT in the management of HTA

Numerical model of aqueous humor drainage: effects of collector channel position.

Glaucoma is a progressive and a degenerative eye disease that gradually deteriorates the vision. The origin of glaucoma is still under debate. Recent studies report that 50% of the aqueous humor outflow resistance resides on collector channels and Schlemm's canal (SC). This paper provides a descriptive analysis of the aqueous humor outflow through the anterior chamber, the trabecular meshwork (TM) and the SC. The aim of this work is to determine the influence of the collector channels position on the intraocular pressure (IOP) and its contribution to the development of glaucoma. Pressure and wall shear stress distributions are presented for four cases. The first case has an arrangement of collector channels according to micro CT (Gong and Francis, 2014). The remaining cases have an symmetrical distribution; case 2 has all open quadrants (AOQ), cases 3 have three quadrants completely open and just one quadrant semi closed (SCQ), and finally cases 4 consider that a quadrant is completely closed (CQ). Symmetrical and micro CT cases have 29 collector channels. The results show that the position and the opening of the collector channels have a strong influence on the IOP.

Influencia de la Posición de los Canales Colectores en la Presión Intraocular / Influence of the Collector Channels on the Intraocular Pressure

RESUMEN: El objetivo del presente trabajo es determinar la influencia que tiene la posición de los canales colectores en la presión intraocular y su contribución en el desarrollo del glaucoma. Para realizar el análisis se llevaron acabo simulaciones numéricas utilizando el método de elemento finito para dos casos de estudio. El primer caso es un modelo simplificado de sección rectangular que simula el flujo entre dos canales colectores; el segundo modelo describe el flujo en todo el canal de Schlemm (CS), considerando que es un aro rígido de espesor constante, con cuatro distribuciones de los canales colectores. Se obtuvieron los perfiles de presión y velocidad en los dos casos. En el caso simplificado se tienen diferencias de 10 P a entre las presiones medias. El segundo modelo muestra que el arreglo simétrico tiene una distribución de presiones constante mientras que los casos asimétricos presentan variaciones de 2 P a. Los resultados confirman que la posición de los canales colectores tiene influencia en la presión intraocular. Este estudio da lugar a realizar un análisis en estado transitorio, considerando las propiedades elásticas del CS así como las variaciones de diámetro de los canales colectores.

ABSTRACT: The aim of the present study is to determine the influence of the position of the collecting channels on intraocular pressure and its contribution to the development of glaucoma. Numerical simulations were performed using the finite element method for two case studies. The first case is a simplified model of rectangular section that simulates the flow between two collecting channels. The second model describes flow throughout the Schlemm channel (CS), considering that it is a rigid ring of constant thickness, with four distributions of the collector channels. The pressure and velocity profiles are shown for both cases. In the simplified case, there are differences of 10 P a between the average pressures. The second model shows that the symmetric arrangement has a constant pressure distribution while the asymmetric cases have variations of 2 P a. The results confirm that the position of the collecting channels influences the intraocular pressure. This study shows that a transient analysis is needed to understand the whole process, considering the elastic properties of the CS as well as the variations of diameter of the collecting channels.

Estudio de la eficacia y utilidad de la fisioterapia respiratoria en la bronquiolitis aguda del lactante hospitalizado. Ensayo clínico aleatorizado y doble ciego / Chest physiotherapy and bronchiolitis in the hospitalised infant. Double-blind clinical trial

Objetivo: Estudiar la utilidad de una modalidad específica de fisioterapia respiratoria, consistente en maniobras de espiración lenta prolongada seguida de tos provocada, en el tratamiento de la bronquiolitis aguda (BA) del lactante hospitalizado. Pacientes y métodos: Ensayo clínico aleatorizado y doble ciego realizado con 236 pacientes de edad inferior a 7 meses e ingresados con diagnóstico de bronquiolitis aguda, primer episodio, en la sección de lactantes de un hospital pediátrico de Madrid. Los pacientes fueron distribuidos aleatoriamente en el momento del ingreso en dos grupos: los que recibieron maniobras de fisioterapia respiratoria y los que recibieron otras maniobras placebo. Únicamente los fisioterapeutas que intervinieron en el estudio conocían la asignación de los niños. Los días de hospitalización y las horas de oxigenoterapia fueron utilizados como medida de resultado. Resultados: De la totalidad de los niños estudiados, el 57,6% recibió maniobras de fisioterapia respiratoria y el 42,4% restante recibió maniobras placebo. En el grupo que recibió fisioterapia la estancia media en el hospital fue de 4,56 días (intervalo de confianza [IC] del 95%, 4,36-6,06) y el tiempo medio de oxigenoterapia fue de 49,98 horas (IC del 95%, 43,64-67,13) frente a 4,54 días (IC del 95%, 3,81-5,73) y 53,53 horas (IC del 95%, 48,03-81,40), respectivamente, en el grupo que no recibió fisioterapia. Estos resultados en ningún caso alcanzan significación estadística. Los pacientes con estudio positivo de VRS (virus respiratorio sincitial) en aspirado nasofaríngeo y que recibieron maniobras de fisioterapia necesitaron menos horas de oxigenoterapia 48,80 horas (IC del 95%, 42,94-55,29) frente a 58,68 horas (IC del 95%, 55,46-65,52), respectivamente, siendo el único resultado estadísticamente significativo (p=0,042). Conclusiones: Los resultados obtenidos muestran que la fisioterapia respiratoria no ha sido eficaz para reducir la estancia hospitalaria ni el tiempo de oxigenoterapia en los pacientes con bronquiolitis aguda, sin embargo, en los niños con estudio positivo de VRS en aspirado nasofaríngeo se observó una necesidad menor de horas de oxígeno (p=0,042) (AU)

Objetive: To study the utility of chest physiotherapy by increased exhalation technique with assisted cough in the acute bronchiolite of the hospitalized new-born babys. Patients and methods: Double-blind clinical trial accomplished on 236 patients of age lower than 7 months and hospitalizad with diagnosis of acute bronchiolitis, first episode, in a pediatric department in Madrid. The patients were randomized in two groups: those who have received maneuvers of chest physiotherapy and those who have received maneuvers placebo. Only physiotherapist were aware of the allocation group of the infants. The days of hospitalization and the hours of oxygen therapy were used like result measurement. Results: From the totality of the studied children 57,6% received maneuvers of chest physiotherapy and 42,4% remaining received maneuvers placebo. In the group that received chest physiotherapy the average stay in the hospital was 4,56 days (95% confidence interval [CI] 4,36-6,06) and the average time of oxygen therapy was 49,98 (95% CI 43,64-67,13) hours opposite to 4,54 days (95%CI 3,81-5,73) and 53,53hours (95% CI 48,03-81,40) respectively in the group that did not receive chest physiotherapy. In the patients with analytical print for VRS and that received chest physiotherapy less hours of oxygen therapy were needed 48,80hours (95% CI 42,94-55,29) opposite to 56,68hours (95% CI 55,46-65,52) respectively, being the only one turned out as per statistics significantly (P=.042). Conclusions: Results show that chest physiotherapy has not been effective in reducing hospital stay or length of oxygen therapy in patients with acute bronchiolitis, but in the positive study of children with respiratory syncytial virus in nasopharyngeal aspirate showed a reduced need hours of oxygen. hours (P=.042)(AU)

[Chest physiotherapy and bronchiolitis in the hospitalised infant. Double-blind clinical trial]. / Estudio de la eficacia y utilidad de la fisioterapia respiratoria en la bronquiolitis aguda del lactante hospitalizado. Ensayo clínico aleatorizado y doble ciego.

OBJECTIVE: [corrected] To study the utility of chest physiotherapy by increased exhalation technique with assisted cough in the acute bronchiolite of the hospitalized new-born babys. PATIENTS AND METHODS: Double-blind clinical trial accomplished on 236 patients of age lower than 7 months and hospitalizad with diagnosis of acute bronchiolitis, first episode, in a pediatric department in Madrid.The patients were randomized in two groups: those who have received maneuvers of chest physiotherapy and those who have received maneuvers placebo. Only physiotherapist were aware of the allocation group of the infants. The days of hospitalization and the hours of oxygentherapy were used like result measurement. RESULTS: From the totality of the studied children 57,6% received maneuvers of chest physiotherapy and 42,4% remaining received maneuvers placebo. In the group that received chest physiotherapy the average stay in the hospital was 4,56 days (95% confidence interval [CI] 4,36-6,06) and the average time of oxygentherapy was 49,98 (95% CI 43,64-67,13) hours opposite to 4,54 days (95%CI 3,81-5,73) and 53,53 hours (95% CI 48,03-81,40) respectively in the group that did not receive chest physiotherapy. In the patients with analytical print for VRS and that received chest physiotherapy less hours of oxygen therapy were needed 48,80 hours (95% CI 42,94-55,29) opposite to 56,68 hours (95% CI 55,46-65,52) respectively, being the only one turned out as per statistics significantly (P=.042). CONCLUSIONS: Results show that chest physiotherapy has not been effective in reducing hospital stay or length of oxygentherapy in patients with acute bronchiolitis, but in the positive study of children with respiratory syncytial virus in nasopharyngeal aspirate showed a reduced need hours of oxygen. hours (P=.042).

Ozone as u-shaped dose responses molecules (hormetins).

Redox environment involves a broad network of pro-oxidant and antioxidant components. Health benefit or damage can be induced as a consequence of an adaptive cellular stress response. A consequence of hormetic amplification is an increase in the homeodynamic space of a living system in terms of an increased defense capacity and a reduced load of damaged macromolecules. Ozone, when used at appropriate doses, promotes the formation of reactive oxygen species and lipid peroxides allows them to become late and long-lasting messengers. Healthy aging may be achieved by hormesis through mild and periodic, but not severe or chronic, physical and mental challenges, and by the use of nutritional hormesis incorporating mild stress-inducing molecules called hormetins. The paradoxical concept that ozone eventually induces an antioxidant response capable of reversing a chronic oxidative stress is common in the animal and vegetal kingdom; it is already supported by findings of an increased level of antioxidant enzymes during ozone therapy. Those facts can include ozone as a hormetin. The established scientific foundations of hormesis are ready to pave the way for new and effective approaches in redox-related disease research and intervention; ozone therapy can be a good candidate.

Cellular redox status regulates hypoxia inducible factor-1 activity. Role in tumour development.

The transcription factor hypoxia-inducible factor-1 (HIF-1) regulates the expression of more than 100 genes involved in cellular adaptation and survival under hypoxic stress. Activation of HIF-1 is associated with numerous physiological and pathological processes that include tumorigenesis, vascular remodelling, inflammation, and hypoxia/ischemia-related tissue damage. Experimental data support the concept that modulation of Reactive Oxygen Species (ROS) levels have an important impact on the hypoxic response mediated by HIF-1 alpha. However, ROS generation, the exact kinetics and conditions of ROS production and their specific relevance to HIF-l alpha activation are issue still to be clarified. Clinical studies suggested that HIF-1 activation correlates directly with advanced disease stages and treatment resistance among cancer patients. Preclinical studies support the inhibition of HIF-1 as a major molecular target for anti-tumour drug discovery. Considerable effort is underway to identify therapeutically useful molecule HIF-1 inhibitors. Most of the compounds discovered to inhibit HIF-1 are natural products or synthetic compounds with structures that are based on natural product leads. Natural products have also served a vital role as molecular probes to elucidate the pathways that regulate HIF-1 activity. Many of the substances found to inhibit HIF-I are non-druggable compounds that are too cytotoxic to serve as drug leads. The application of high-throughput screening methods, complementary molecular-targeted assays, and structurally diverse chemical libraries hold promise for the discovery of therapeutically useful HIF-1 inhibitors.

Effects of ozone oxidative preconditioning on nitric oxide generation and cellular redox balance in a rat model of hepatic ischaemia-reperfusion.

BACKGROUND: Many studies indicate that oxygen free-radical formation after reoxygenation of liver may initiate the cascade of hepatocellular injury. It has been demonstrated that controlled ozone administration may promote an oxidative preconditioning or adaptation to oxidative stress, preventing the damage induced by reactive oxygen species and protecting against liver ischaemia-reperfusion (I/R) injury. AIMS: In the present study, the effects of ozone oxidative preconditioning (OzoneOP) on nitric oxide (NO) generation and the cellular redox balance have been studied. METHODS: Six groups of rats were classified as follows: (1). sham-operated; (2). sham-operated+l-NAME (N(omega)-nitro-l-arginine methyl ester); (3). I/R (ischaemia 90 min-reperfusion 90 min); (4). OzoneOP+I/R; (5). OzoneOP+l-NAME+I/R; and (6). l-NAME+I/R. The following parameters were measured: plasma transaminases (aspartate aminotransferase, alanine aminotransferase) as an index of hepatocellular injury; in homogenates of hepatic tissue: nitrate/nitrite as an index of NO production; superoxide dismutase (SOD), catalase (CAT) and glutathione levels as markers of endogenous antioxidant system; and finally malondialdehyde+4-hydroxyalkenals (MDA+4-HDA) and total hydroperoxides (TH) as indicators of oxidative stress. RESULTS: A correspondence between liver damage and the increase of NO, CAT, TH, glutathione and MDA+4-HDA concentrations were observed just as a decrease of SOD activity. OzoneOP prevented and attenuated hepatic damage in I/R and OzoneOP+l-NAME+I/R, respectively, in close relation with the above-mentioned parameters. CONCLUSIONS: These results show that OzoneOP protected against liver I/R injury through mechanisms that promote a regulation of endogenous NO concentrations and maintenance of cellular redox balance. Ozone treatment may have important clinical implications, particularly in view of the increasing hepatic transplantation programs.

"Mangifera indica L. extract (QF808) reduces ischaemia-induced neuronal loss and oxidative damage in the gerbil brain".

The effect of oral administration of Mangifera indica L. extract (QF808) on ischemia-reperfusion-induced neuronal death in the gerbil hippocampal CA1 sector was examined. Oral administration of QF808 for 7 days dose-dependently protected against neuronal cell death following transient ischaemia and reperfusion as assessed by histopathology. In addition, locomotor activity assessment prior to ischaemia and 7 days after correlated well with the histological results. To evaluate redox alterations by reactive oxygen species, total sulfhydryl, non-protein sulfhydryl groups (NPSH), malondialdehyde + 4-hydroxyalkenals and total nitrogen oxide levels were assayed in hippocampus and cortex homogenates. QF808 treatment attenuated NPSH loss, nitrogen oxide levels and lipid peroxidation in the hippocampus. These results suggest that orally administered QF808 is absorbed across the blood-brain barrier and attenuates neuronal death of the hippocampal CA1 area after ischaemia-reperfusion. These protective effects are most likely due to the antioxidant activity of QF808.

[The attitude of primary health care physicians in the metropolitan area of Barcelona about the diagnosis and treatment of Helicobacter pylori infection in gastroduodenal diseases]. / Actitud de los médicos de atención primaria del área metropolitana de Barcelona frente al diagnóstico y tratamiento de la infección por Helicobacter pylori en enfermedades gastroduodenales.

AIM: To evaluate the attitude of primary health care physicians versus the diagnosis and treatment of infection by Helicobacter pylori in patients with dyspepsia and gastroduodenal ulcer. DESIGN: An observational, transversal study was performed by a self administered questionnaire from June to October, 1997. PARTICIPANTS: Primary health care physicians from 38 reformed Medical Centers in the metropolitan area of Barcelona were included in the study. RESULTS: Of the 359 doctors to whom the questionnaire was sent, 283 responded (78.8%). In a patient with dyspepsia 95.4% would first request endoscopy. If they knew of the presence of infection by Helicobacter pylori 96.1% would administer eradication treatment in patients with gastric and duodenal ulcer and 15% would also do so if the endoscopy were normal. If the presence of infection by Helicobacter pylori were unknown in a patient with gastroduodenal ulcer, 65.3% would treat with anti-H2 or proton pump inhibitors associated with a diagnostic test of infection by Helicobacter pylori. If the physician decided to carry out eradication treatment of Helicobacter pylori infection, 98.6% would use one of the regimes recommended by different scientific societies. If confirmation of eradication of Helicobacter pylori infection were requested, 89% would do so one and three months after completion of treatment. In patients with gastric ulcer, 69.3% would request endoscopy on completion of treatment. The percentage of physicians specialized in Family and Community Medicine who would carry out eradication treatment in patients with duodenal ulcer and Helicobacter pylori infection and who would request endoscopies in patients with dyspepsia was found to be statistically significant in comparison with physicians without this specialty. CONCLUSIONS: The attitude of primary care physicians in the metropolitan area of Barcelona with regard to the diagnosis and treatment of infection by Helicobacter pylori in gastroduodenal diseases largely reflects the recommendations recently made by several scientific societies. In general there are no significant differences with respect to this attitude in regard to the age and sex of the physician, although their training was found to influence in some of the responses analyzed.