Divergent roles of IREG/Ferroportin transporters from the nickel hyperaccumulator Leucocroton havanensis.

In response to our ever-increasing demand for metals, phytotechnologies are being developed to limit the environmental impact of conventional metal mining. However, the development of these technologies, which rely on plant species able to tolerate and accumulate metals, is partly limited by our lack of knowledge of the underlying molecular mechanisms. In this work, we aimed to better understand the role of metal transporters of the IRON REGULATED 1/FERROPORTIN (IREG/FPN) family from the nickel hyperaccumulator Leucocroton havanensis from the Euphorbiaceae family. Using transcriptomic data, we identified two homologous genes, LhavIREG1 and LhavIREG2, encoding divalent metal transporters of the IREG/FPN family. Both genes are expressed at similar levels in shoots, but LhavIREG1 shows higher expression in roots. The heterologous expression of these transporters in A. thaliana revealed that LhavIREG1 is localized to the plasma membrane, whereas LhavIREG2 is located on the vacuole. In addition, the expression of each gene induced a significant increase in nickel tolerance. Taken together, our data suggest that LhavIREG2 is involved in nickel sequestration in vacuoles of leaf cells, whereas LhavIREG1 is mainly involved in nickel translocation from roots to shoots, but could also be involved in metal sequestration in cell walls. Our results suggest that paralogous IREG/FPN transporters may play complementary roles in nickel hyperaccumulation in plants.

ELIXIR biovalidator for semantic validation of life science metadata.

SUMMARY: To advance biomedical research, increasingly large amounts of complex data need to be discovered and integrated. This requires syntactic and semantic validation to ensure shared understanding of relevant entities. This article describes the ELIXIR biovalidator, which extends the syntactic validation of the widely used AJV library with ontology-based validation of JSON documents. AVAILABILITY AND IMPLEMENTATION: Source code: https://github.com/elixir-europe/biovalidator, Release: v1.9.1, License: Apache License 2.0, Deployed at: https://www.ebi.ac.uk/biosamples/schema/validator/validate. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Assessment of aquatic food web and trophic niche as a measurement of recovery function in restored mangroves in the Southern Gulf of Mexico.

Mangroves are coastal wetlands with high biodiversity and productivity, with great interaction with coastal environments. In the face of worldwide mangrove loss, restoration projects attempt to recover ecosystem composition and functioning over time. Our objective was to examine and compare the food webs in mangrove areas with different restoration times and in a reference mangrove in Términos Lagoon, Mexico. We estimated the trophic structure, identified the carbon resources that maintain aquatic consumers through the analysis of stable isotopes, and compared the trophic niche of the restored mangroves with the reference mangrove. We analyzed environmental variables, trophic structure, and contributions of resources during three seasons: rainy, dry, and "nortes". Environmental changes and food structure changed in response to regional seasons. Bayesian mixing models indicated that food webs varied seasonally as a response to the primary productivity developed at Términos Lagoon. As expected, the assimilation of C3 plants in the reference mangrove was highest, as a primary ("nortes" season) and secondary resource (dry and rainy seasons). The restored mangroves depended mainly on allochthonous resources (seagrass, epiphytes, and phytoplankton). The assimilation of these resources highlighted the importance of connectivity and the input of sources of carbon from nearby coastal environments. Trophic niche analysis showed that the area with longer restoration time was more similar to the reference mangrove, which is evidence of the importance and efficacy of the restoration process, as well as the restoration of the ecosystem function over time.

Prediction of molecular interactions and physicochemical properties relevant for vasopressin V2 receptor antagonism.

We have developed two ligand- and receptor-based computational approaches to study the physicochemical properties relevant to the biological activity of vasopressin V2 receptor (V2R) antagonist and eventually to predict the expected binding mode to V2R. The obtained quantitative structure activity relationship (QSAR) model showed a correlation of the antagonist activity with the hydration energy (EH2O), the polarizability (P), and the calculated partial charge on atom N7 (q6) of the common substructure. The first two descriptors showed a positive contribution to antagonist activity, while the third one had a negative contribution. V2R was modeled and further relaxed on a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocoline (POPC) membrane by molecular dynamics simulations. The receptor antagonist complexes were guessed by molecular docking, and the stability of the most relevant structures was also evaluated by molecular dynamics simulations. As a result, amino acid residues Q96, W99, F105, K116, F178, A194, F307, and M311 were identified with the probably most relevant antagonist-receptor interactions on the studied complexes. The proposed QSAR model could explain the molecular properties relevant to the antagonist activity. The contributions to the antagonist-receptor interaction appeared also in agreement with the binding mode of the complexes obtained by molecular docking and molecular dynamics. These models will be used in further studies to look for new V2R potential antagonist molecules.

The X-ray fluorescence screening of multiple elements in herbarium specimens from the Neotropical region reveals new records of metal accumulation in plants.

Plants have developed a diversity of strategies to take up and store essential metals in order to colonize various types of soils including mineralized soils. Yet, our knowledge of the capacity of plant species to accumulate metals is still fragmentary across the plant kingdom. In this study, we have used the X-ray fluorescence technology to analyze metal concentration in a wide diversity of species of the Neotropical flora that was not extensively investigated so far. In total, we screened more than 11 000 specimens representing about 5000 species from herbaria in Paris and Cuba. Our study provides a large overview of the accumulation of metals such as manganese, zinc, and nickel in the Neotropical flora. We report 30 new nickel hyperaccumulating species from Cuba, including the first records in the families Connaraceae, Melastomataceae, Polygonaceae, Santalaceae, and Urticaceae. We also identified the first species from this region of the world that can be considered as manganese hyperaccumulators in the genera Lomatia (Proteaceae), Calycogonium (Melastomataceae), Ilex (Aquifoliaceae), Morella (Myricaceae), and Pimenta (Myrtaceae). Finally, we report the first zinc hyperaccumulator, Rinorea multivenosa (Violaceae), from the Amazonas region. The identification of species able to accumulate high amounts of metals will become instrumental to support the development of phytotechnologies in order to limit the impact of soil metal pollution in this region of the world.

Large-scale application of highly-diluted bacteria for Leptospirosis epidemic control.

BACKGROUND: Leptospirosis is a zoonotic disease of major importance in the tropics where the incidence peaks in rainy seasons. Natural disasters represent a big challenge to Leptospirosis prevention strategies especially in endemic regions. Vaccination is an effective option but of reduced effectiveness in emergency situations. Homeoprophylactic interventions might help to control epidemics by using highly-diluted pathogens to induce protection in a short time scale. We report the results of a very large-scale homeoprophylaxis (HP) intervention against Leptospirosis in a dangerous epidemic situation in three provinces of Cuba in 2007. METHODS: Forecast models were used to estimate possible trends of disease incidence. A homeoprophylactic formulation was prepared from dilutions of four circulating strains of Leptospirosis. This formulation was administered orally to 2.3 million persons at high risk in an epidemic in a region affected by natural disasters. The data from surveillance were used to measure the impact of the intervention by comparing with historical trends and non-intervention regions. RESULTS: After the homeoprophylactic intervention a significant decrease of the disease incidence was observed in the intervention regions. No such modifications were observed in non-intervention regions. In the intervention region the incidence of Leptospirosis fell below the historic median. This observation was independent of rainfall. CONCLUSIONS: The homeoprophylactic approach was associated with a large reduction of disease incidence and control of the epidemic. The results suggest the use of HP as a feasible tool for epidemic control, further research is warranted.

In silico strategy for detailing the binding modes of a novel family of peptides proven as ghrelin receptor agonists.

Ghrelin is a peptide hormone involved in multiple functions, including growth hormone release stimulation, food intake regulation, and metabolic and cytoprotective effect. A novel family of peptides with internal cycles was designed as ghrelin analogs and the biological activity of two of them (A228 and A233) was experimentally studied in-depth. In this work, an in silico strategy was developed for describing and assessing the binding modes of A228 and A233 to GHS-R1a (ghrelin receptor) comparing it with ghrelin and GHRP-6 peptides. Several reported structures of different G protein coupled receptors were used as templates, to obtain a good quality model of GHS-R1a. The best model was selected by preliminary molecular docking with ghrelin and GHRP-6. Docking was used to estimate peptide orientations in the binding site of the best model, observing a superposition of its N-terminal and its first aromatic residue. To test the complex stability in time, the C-terminal fragments of each peptide were added and the complexes were inserted a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane, performing a molecular dynamic simulation for 100 ns using the CHARMM36 force field. Despite of the structural differences, the studied peptides share a common binding mode; the N-terminal interacts with E124 and the aromatic residue close to it, with the aromatic cluster (F279, F309, and F312). A preliminary pharmacophore model, consisting in a positive charged amine and an aromatic ring at an approximate distance of 0.79 nm, can be proposed. The results here described could represent a step forward in the efficient search of new ghrelin analogs.

Absence of hypoxia events in the adjacent coastal waters of Grijalva-Usumacinta river, Southern Gulf of Mexico.

Globally, oxygen concentration in many coastal areas is depleting. River nutrient discharges may produce hypoxia events. The Southern Gulf of Mexico receives the discharges of the Grijalva-Usumacinta River System, the second largest in the Gulf of Mexico. To evaluate the influence of river discharges on dissolved oxygen concentrations in the receiving coastal ecosystem, we studied the variation of physicochemical variables in the water column. During the dry season, the influence of the river waters to the coastal area is scarce, but during the rainy season the river plume reached ~9 km offshore. The lowest concentration of dissolved oxygen (3.6 mg L-1) was observed within the river plume. We concluded that, in the studied area, hypoxia events (oxygen concentrations ≤ 2 mg L-1) would occur during the rainy season, low winds and in deeper waters (>80 m depth).

Relación longitud-peso, y factor de condición relativa de postlarvas epibentónicas y de jóvenes, del camarón rosado Farfantepenaeus duorarum (Crustacea: Penaeidae) en Laguna de Términos, México

El comportamiento del peso, la talla y el factor de condición de los organismos es importante para explicar la dinámica de las poblaciones de organismos en el medio natural. El presente estudio está dirigido a encontrar los modelos que explican la relación longitud-peso, así como el factor de condición relativo en postlarvas epibentónicas y juveniles de Farfantepenaeus duorarum, recolectados durante los diferentes meses muestreados. En el trabajo se recolectaron 3 992 camarones de la especie F. duorarum con rangos de longitud del cefalotórax entre 3.62-32.16 mm, provenientes de tres sitios diferentes de la Laguna de Términos, entre los meses de mayo 2011 y marzo 2012. Los individuos fueron agrupados en tres categorías según el sexo: machos (M), hembras (H), e indefinidos (I) y se determinó la relación longitud peso (L-P-1), relación longitud total (LT)-longitud del cefalotórax (LC), así como el factor de condición relativo (Kn). Los resultados indican que la relación longitud total-longitud del cefalotórax (LT-LC) para cada categoría de sexo fue lineal y que no existe diferencia entre el modelo de regresión encontrado para machos y para hembras quedando expresado como: (LT (M-H) = 1.89 + 4.46 LC). Para el grupo con sexo indefinido la relación fue diferente al resto de los camarones y puede ser expresado como LT (I) = 0.07 + 4.62 LC. El modelo potencial para expresar la relación (L-P-1) en el grupo M-H es P = 0.0016 LC2.5323 o expresado de manera lineal como log (P) = 2.5323 log(LC) - 2.8079, con R² = 0.9272. En el grupo indefinido el modelo potencial es P = 0.0004LC3.2315 y el de manera lineal, log (P) = 3.2315 log(LC) - 3.4365, con R2= 0.9422. Por otro lado, el factor de condición relativa (Kn) difirió entre los grupos cuando se incluye a la fecha en el análisis. Se considera que el factor de condición relativo que contempla a la longitud total es mejor que el factor de condición relativo obtenido con la longitud del cefalotórax para evaluar las características de los camarones y pudiera contribuir para evaluar la dinámica de la población de camarones.

The knowledge about the weight, length and condition factor of the organisms is key for explaining the population dynamics in wild animals. The present study was focused on finding the model that best explains the length-weight relationships in epibenthic and juveniles of Farfantepenaeus duorarum, as well as the condition factor during the different months sampled. In the study, 3 992 individuals (size range: 3.62-32.16 mm cephalothorax length) were collected from three different places at the Terminos Lagoon from May 2011 to March 2012. The individuals were grouped into three sex categories: male (M), female (H), and undefined (I), and their length-weight (L-P-1) relationship, as well as their relative condition factor, were determined. The results indicate that the total length-carapace length (LT-LC) relationship for each sex category was linear, there was no difference between the models for small males and females and the relationship can be expressed as (LT (M-H) = 1.89 + 4.46 LC). For the undefined group, the relationship was different and is best expressed as LT (I) = 0.07 + 4.62 LC. The potential model for the expression of Carapace Length-Weight in the M-H group was P = 0.0016 LC2.5323 or log (P) = 2.5323 log(LC) - 2.8079, R² = 0.9272 in the linear model. In the undefined group, the potential model was W = P = 0.0004LC3.2315 and the linear model was log (P) = 3.2315 log(LC) - 3.4365, R2 = 0.9422. On the other hand, the relative condition factor (Kn) differed among groups when the date was involved in the analysis. We consider that relative condition factor involving Total Length is better than relative condition factor including Carapace Length to measure population characteristics of shrimps and that index could contribute to evaluating the shrimp population dynamics.

Formación de tecnólogos como promotores de la salud para la prevención de infecciones de transmisión sexual / Technologists training as health promoters for the prevention of sexually transmitted infections

Se realizó un estudio descriptivo de corte longitudinal en la Facultad de Tecnología de la Salud "Dr. Juan Manuel Páez Inchausti" de Santiago de Cuba, durante el 2013, a fin de caracterizar y perfeccionar la formación de los tecnólogos en cuanto a la promoción de la salud. Para desarrollar esta propuesta fue necesaria la utilización de un conjunto de métodos y técnicas, que permitieran partir de los elementos más esenciales que caracterizan el proceso de formación de este estudiante de la salud, hasta llegar a las particularidades en el contexto de la universidad cubana actual. Finalmente, se evidenció la necesidad de formar, de manera permanente, tecnólogos promotores de la salud que posean todas las habilidades necesarias para crear conciencia, en sus coetáneos, la familia y la sociedad, de cómo erradicar conductas irresponsables en las relaciones sexuales y así poder prevenir las infecciones de transmisión sexual.

A descriptive study of longitudinal type at "Dr. Juan Manuel Páez Inchausti" Health Technology Faculty was carried out in Santiago de Cuba, during 2013, in order to characterize and improve the technologists training regarding health promotion. To develop this proposal it was necessary the use of a group of methods and techniques that allowed to start from the most essential elements that characterize the training process of this health student, up to reaching the particularities in the context of the current Cuban university. Finally, the necessity of training, in a permanent way, health technologists promoters who possess all the necessary skills to create conscience, in its contemporaries, in the family and in the society, of how to eradicate irresponsible behaviours in the sexual relationships and in this way to be able to prevent the sexually transmitted infections was evidenced.

Proceso formativo extensionista para el desarrollo de destrezas en la promoción de salud / Extensive training process for the development of skills in health promotion

Se realizó una revisión bibliográfica exhaustiva en la Facultad de Tecnología de la Salud "Dr. Juan Manuel Páez Inchausti" de Santiago de Cuba, con vistas a potenciar el proceso formativo extensionista para el desarrollo de destrezas comunicativas en las actividades de promoción de salud, para lo cual se emplearon métodos empíricos y teóricos. Asimismo, se presentaron preceptos teóricos y experiencias que tributaron al perfeccionamiento de la planificación de acciones para el trabajo extensionista en función de la formación del recurso humano en salud.

A comprehensive literature review was carried out in "Dr. Juan Manuel Páez Inchausti" Health Technology Faculty in Santiago de Cuba, aimed at promoting the extensive training process for the development of communicative skills in health promotion activities, for which empiric and theoretical methods were used. Also, theoretical precepts and experiences that paid the improvement of actions planning were presented for extensive work directed to the training of health human resource.

La modificación covalente de proteínas. Un nivel cualitativamente superior de la información molecular / Covalent Modifications of Proteins. A qualitative higher level of molecular information

Introducción: La información molecular es una propiedad principal de las biomacromoléculas, especialmente proteínas y ácidos nucleicos, que permite la realización de funciones con un alto grado de especificidad. Ella deriva de la variedad en los componentes de las macromoléculas. Objetivo: Demostrar que la modificación covalente de proteínas constituye un nivel nuevo y superior de información molecular. Método: Se analizaron artículos de los últimos 5 años, publicados en revistas nacionales y de circulación internacional, disponibles en las bases de datos HINARI, PubMed y Perii y localizados mediante el sitio www.infomed.sld.cu. Desarrollo: Se exponen los mecanismos y características principales del proceso y posteriormente algunos de los efectos principales de la modificación covalente sobre las funciones y propiedades de las proteínas. Conclusiones: La modificación covalente es un mecanismo que amplía el campo de acción de las proteínas permitiendo un rápido cambio en sus propiedades funcionales y, por lo tanto, constituye un nivel nuevo y cualitativamente superior de información molecular.

Introduction: Molecular information is an essential property of biomacromolecules, especially proteins and nucleic acids. This property allows carrying out specific functions. It derives from variability of macromolecules components. Objetive: To prove that covalent modification of proteins represents a new and higher level of molecular information. Method: Papers published during the last five years in national and international journals were analyzed. These articles are available in HINARI, PubMed, and Perii databases and were localized through www.infomed.sld.cu. Main text: First, the mechanism and features of covalent modifications of protein are presented. Next, the principal effects on protein functions and properties are analyzed. Conclusions: We conclude that covalent modification of proteins represents a new and higher level of molecular information.

La vía ubiquitina-proteasoma ¿destruir o construir? ese es el dilema / Ubiquitin-proteasome pathway to built or to destroy? that is the question

Introducción: la construcción de nuevas células es un proceso complejo y para lograr que sea unidireccional e irreversible la célula utiliza el mecanismo de destruir proteínas que se oponen al paso de una etapa a la siguiente. Objetivo: demostrar que la destrucción de proteínas contribuye a la reproducción celular. Método: se analizaron más de 500 artículos de los últimos 5 años publicados en revistas nacionales y de circulación internacional, disponibles en las bases de datos HINARI, PubMed y Perii y localizados mediante el sitio infomed. Desarrollo: primero, se hizo una exposición sobre la vía ubiquitina-proteasoma. Después, se analizó la participación en el ciclo celular de los dos grandes complejos con actividad de ubiquitina-ligasa que son los encargados de marcar las proteínas que deben ser destruidas. Estos complejos actúan consecutiva y coordinadamente, y sus acciones determinan el progreso en un solo sentido del ciclo de vida de la célula. Conclusiones: la destrucción selectiva de proteínas mediante la vía ubiquitina proteasoma permite la formación de nuevas células y con ello la perpetuación de la vida.

Introduction: the generation of new cells is an extremely complex process. To become this process unidirectional and irreversible cells destroy proteins which actions are oppose to the transition from one phase to the next one. Objective: to show that protein destruction is essential for cell reproduction. Material and Methods: more than 500 papers published during the last five years in national and international journals were analyzed. These articles are available in HINARI, PubMed, and Perii databases and were localized through infomed. Development: first, the ubiquitin-proteasome pathway is presented. Next, the contribution of the complexes SCF an anaphase promoting complex to the progression of the cell cycle is analysed. These complexes act consecutively and coordinately and their actions determine de progression of the cell´s life. Conclusions: the selective destroy of specific proteins by mean of ubiquitin-proteasome pathway, allow new cells formation, and ensure the continuity of life.

Kinasas y fosfatasas: el yin y el yan de la vida / Kinases and phosphatases: the life´s yin yan

Introducción: la existencia de tendencias opuestas en un proceso o fenómeno de la naturaleza es la fuente principal del desarrollo. Objetivo: el principal mecanismo de control de la mayoría de los procesos biológicos al nivel molecular son las modificaciones postraduccionales y dentro de ella los ciclos de fosforilación/desfosforilación. Las proteínas al ser fosforiladas o desfosforiladas experimentan un cambio conformacional que modifica su actividad, sus propiedades, su localización celular y las interacciones con otras moléculas. Resultados: las enzimas implicadas en este ciclo son las kinasas y las fosfatasas, cuyas acciones coordinadas y opuestas dan el soporte mecanístico necesario para el desarrollo de múltiples funciones celulares. Conclusiones: en este trabajo se pretende demostrar, mediante el estudio de la participación de kinasas y fosfatasas en la división celular, que estas enzimas representan la expresión molecular de los contrarios, yin y yan, de la antigua Filosofía China.

Introduction: opposite forces in the inside of a process are the main sources for development. Objective: the principal mechanism to control most biological processes is the postranslational modifications of proteins. Among these the phosphorylation/ ephosphorylation cycle is the most extended in nature. Phosphorylation or dephosphorylation of proteins causes a conformational change that modifies their activities, properties, celular localization and interactions with other molecules. Results: kinases and phosphatese are the main enzymes implied in this cycle which coordinated and opposite actions give the mechanistic support for several cellular functions. Conclusions: by mean of an study about the involvement of kinases and phosphatases in cell division, this paper tray to show that these enzymes represent the molecular expression of the yin and yan, the opposite element on ancient Chinese philosophy.

Neuropatía femoral y hematoma bilateral de músculos psoas-iliaco asociados a tratamiento con warfarina / Femoral neuropathy and bilateral hematoma: psoas-iliac muscles associated with a warfarin treatment

Se presentó un hombre de 70 años que sufrió un hematoma bilateral de los músculos psoas-iliacos como consecuencia del tratamiento con warfarina. Después de 6 d de tratamiento analgésico, valores de índice internacional normalizado inferiores a 1,5 y control del sangrado, se indicó la warfarina para continuar la profilaxis por la prótesis valvular mecánica. Fue egresado con secuelas motoras por la neuropatía femoral y se ha mantenido con tratamiento fisioterapéutico. Se diagnosticó neuropatía por compresión del nervio femoral, por hematoma de los músculos psoas-ilíacos. Los casos de hematomas retroperitoneales son escasos en la literatura médica, en Cuba no encontramos casos publicados...

This is the case of a man suffered of a bilateral hematoma of psoas-iliac muscles as a consequence of warfarin treatment. After 6 days od analgesic treatment, values of INR lower than 1,5 and bleeding control warfarin was prescribed to continue the prophylaxis by mechanical valvular prosthesis. He was discharged with motor sequelae due to femoral neuropathy maintained with a physiotherapy treatment. A neuropathy by compression of femoral nerve due to hematoma of psoas-iliac muscles was diagnosed. The cases of retroperitoneal hematomas are scarce in medical literature and in Cuba there were not published cases...

El tumor de Wilms. Un paradigma de heterogeneidad genética: a paradigm of genetic heterogeneity / Wilm's toumor

El Tumor de Wilms constituye el más frecuente de los cánceres renales pediátricos, aparece antes de los 5 años de edad y con igual frecuencia en ambos sexos. El gen causante de la enfermedad está localizado en 11p13, se extiende unas 50 kb con 10 exones y sus alteraciones pueden ser tanto genéticas como epigenéticas. Por diferentes mecanismos se originan al menos 24 productos con funciones diversas. Existen otras regiones cromosómicas, cuyas alteraciones pueden dar lugar a la aparición del tumor. En este sentido, el Tumor de Wilms es un ejemplo sobresaliente de heterogeneidad genética. El presente trabajo hace un análisis de los fundamentos moleculares de la enfermedad y presenta a modo de ilustración una breve reseña de los principales síndromes hereditarios con predisposición a presentar este tumor.

Wilm's tumor is the most frequent cancer of the kidney in childhood with onset before five year old. WT gene was mapped in 11p13 and span 50 kb with 10 exons. WT modifications would be either genetics or epigenetics. The gene code for at least 24 isoforms of protein products. Other chromosomes loci whose alterations may be cause of disease have been identified, so Wilm's tumor is a remarkable paradigm of genetic heterogeneity. In this paper an analysis of the molecular basis of the disease is presented and, also, a brief references on main hereditary syndromes which include Wilm's tumor.

Fundamentos moleculares de la enfermedad de von Hippel Lindau / Molecular bases of von Hipperl Lindau's disease

La enfermedad de von Hippel Lindau es una rara entidad genética que se caracteriza por la predisposición al cáncer, especialmente angiomas de la retina, hemangioblastomas del sistema nervioso central y carcinoma renal de células claras. Los productos del gen presentan un mecanismo de acción peculiar, pues está relacionado con los procesos de adaptación del organismo a la hipoxia. En este trabajo se presenta una panorámica actualizada de esta enfermedad, con énfasis en los aspectos moleculares

The von Hippel Lindau's disease is uncommon genetic entity characterized by a predisposition to cancer, specially the retina angiomas, hemangioblastomas of central nervous system and the clear cells renal carcinoma. Gene products have a typical action mechanism since it is related to organism adaptation processes to hypoxia. In present paper an updated panorama of this disease emphasizing in molecular processes

Relación entre índice de refracción y sólidos totales en extractos acuosos de Calendula officinalis L. (caléndula) y Ocimum sanctum L (albahaca morada) / Association of the refractive index and the total solids in aqueous extracts from Calendula officinalis L (caléndula) and Ocimum sanctum L (albahaca morada)

INTRODUCCIÓN: los extractos acuosos de Ocimum sanctum L. y de Calendula officinalis L. tienen importancia para la elaboración de medicamentos herbarios. La concentración es uno de los pasos más importantes en el proceso de obtención de extractos acuosos secos. A escalas piloto e industrial, donde los volúmenes de extracto que se obtienen son mayores, resulta muy económica y factible la utilización del índice de refracción como parámetro de control de calidad que da un criterio indirecto de la concentración del extracto en cuestión. OBJETIVO: estudiar el comportamiento del índice de refracción contra la variación de la concentración de sólidos totales y determinar la ecuación que describe el proceso, para facilitar la estandarización del extracto y el paso de concentración. MÉTODOS: se realizaron las respectivas mediciones de índice de refracción a diferentes concentraciones de sólidos totales. RESULTADOS: se obtuvieron las curvas de mejor ajuste y la demostración estadística de su significación y la de los modelos utilizados para los extractos acuosos de O. sanctum y de C. officinalis, lo cual permite utilizar estas ecuaciones para agilizar el control de calidad en los procesos de concentración. CONCLUSIONES: las ecuaciones definidas a partir de los modelos de ajuste lineal permiten, perfectamente, realizar determinaciones de los sólidos totales a partir del índice de refracción, durante los procesos de concentración para ambos extractos acuosos.

INTRODUCTION: the aqueous extracts from Ocimum sanctum L. and Calendula officinalis L. are important to produce herbal medicines. The concentration is one of the fundamental steps in the process of obtaining dry aqueous extracts. At pilot and industrial scales, in which the extract volumes are higher, it is very economical and feasible to use the refractive index as quality control parameter since it provides an indirect criterion about the extract concentration. OBJECTIVE: to study the behaviour of the refractive index against the total solid concentration variations and thus to estimate the equation describing this process in order to make the standardization of the extract and the concentration step easier. METHODS: refractive index measurements at various total solid concentrations were made. RESULTS: the best fitted curves as well as the statistical demonstration of their significance and that of the models used for O. sanctum and C. officinalis aqueous extracts were estimated, which allows using these equations to facilitate the quality control in the concentration process. CONCLUSIONS: the equations based on the linear fit models make it possible to determine total solids for both aqueous extracts by using the refractive index.

Optimización de un proceso de obtención de extracto acuoso de Ocimum sanctum L (albahaca morada) / Optimizing a process to obtain Ocimum sanctum L. (albaca morada) aqueous extract

INTRODUCCIÓN: Ocimum sanctum L. (albahaca morada) es una especie medicinal tradicional con efecto hipoglucemiante y otros de interés terapéutico. OBJETIVOS: optimizar una tecnología de obtención de extracto acuoso de O. sanctum y analizar la influencia de los parámetros de proceso. MÉTODOS: se estudió el efecto de 3 variables en el proceso de obtención del extracto acuoso de las hojas y su optimización a partir de la maximización de los sólidos totales en el extracto y los valores de recobrados, obtenidos en un reactor cilíndrico de laboratorio con geometría desescalada de un reactor industrial. El estudio de superficie de respuesta realizado, utiliza un diseño híbrido con 11 experimentos, logra analizar 3 factores en 5 niveles y da una respuesta adecuada a la necesidad de determinar la influencia de las variables de proceso y los valores óptimos para la extracción. RESULTADOS: la relación droga disolvente resultó ser la variable analizada que influyó con mayor significación en la extracción, aunque todas fueron significativas; y 100 ºC de temperatura, relación droga/disolvente (1:11) y 3 h de agitación, resultaron ser los parámetros óptimos de operación, para el procedimiento propuesto. CONCLUSIONES: se determinó cuáles de los factores estudiados tenían influencia sobre el proceso, se demostró su significación y, además, se logró optimizar una tecnología de obtención de extracto acuoso de O. sanctum determinando los valores más adecuados para los parámetros de operación.

INTRODUCTION: Ocimum sanctum L. (albahaca morada) is a traditional medicinal herb with hypoglycaemic action and other therapeutic effects.OBJECTIVES: to optimize a technique for obtaining aqueous extract from O. sanctum and to analyze the impact of the process parameters. METHODS: the effect of three variables in the process of obtaining aqueous extract from O. sanctum leaves was studied along with the optimization of this technique on the basis of maximizing the number of total solids present in the extract and the recovery values by using a lab cylindrical reactor with de-scaled geometry of an industrial reactor. The response surface study used hybrid design of eleven experiments, managed to analyze 3 factors at five levels and adequately responded to the need of finding out the impact of the process variables and the optimal extraction values. RESULTS: drug-solvent ratio was the most influential variable, being the most significant in the extraction, although all of them were significant. Also, 100 ºC temperature, drug/solvent ratio (1:11) and three hours for shaking were the optimal operational parameters for the suggested process. CONCLUSIONS: the factors having the highest impact on the process and their significance were found. Additionally, the technique to obtain O. sanctum aqueous extract was optimized by estimating the most adequate values for operational parameters.