Reactores Bioquímicos Pasivos: Una alternativa biotecnológica para la remediación de drenajes ácidos de mina / Biochemical passive reactors: a biotechnological alternative to remediation of acid mine drainage

RESUMEN El Drenaje ácido de mina (DAM) es actualmente el principal contaminante de las regiones mineras. Los reactores bioquímicos pasivos son una tecnología sostenible fácil de instalar que utiliza desechos agroindustriales de la región y puede operar en áreas remotas con poco mantenimiento. Además, son una tecnología limpia que involucra bioprocesos, reacciones químicas y precipitación de metales, minimizando el impacto de los vertimientos ácidos sobre suelos y cuerpos de aguas. Los reactores bioquímicos pasivos son columnas empacadas con una "mezcla reactiva" conformada por materiales orgánicos, inorgánicos y un inóculo microbiano. En esta mezcla se remedia el DAM por medio de procesos fisicoquímicos como la adsorción, precipitación, coprecipitación de los metales y de la reducción del sulfato a sulfuro, mientras se incrementa el pH y la alcalinidad. Con el fin de brindar información reciente, así como las necesidades de investigación en el tema, este documento presenta una revisión de literatura sobre la generación química y biológica de los DAM, así como su remedición utilizando reactores bioquímicos pasivos. El conocimiento de los conceptos básicos de estos procesos es extremadamente útil para evaluar las posibles aplicaciones, beneficios y limitaciones de estos sistemas de tratamiento utilizados por la biotecnología durante la biorremediación de efluentes mineros.

ABSTRACT Acid Mine Drainage (AMD) is currently the main pollutant in mining areas. Passive biochemical reactors are a sustainable technology easy to install using agro-industry waste from the mining region and operating in remote locations. Besides, bioreactors are clean technology that involves bioprocesses, chemical reactions, and metal precipitation, minimizing the impact of AMD on soils and fresh water sources. The passive biochemical reactors are columns packed with a "reactive mixture" consisting of organic, inorganic materials and a microbial inoculum. In this reactive mixture, AMD is remediated through physicochemical processes such as metals adsorption, precipitation, and co-precipitation, as well as, the reduction of sulfate to sulfur, while pH and alkalinity are in-creased. To provide recent information and research needs in the subject, this document presents a review of the literature about the chemical and biological generation of AMD and its remediation using passive biochemical reactors. The knowledge of the basic concepts of these processes is extremely useful to evaluate the possible applications, benefits and limitations of these treatment systems used by biotechnology during the bioremediation of mining effluents.

Characterization of a Panela cheese with added probiotics and fava bean starch.

Of 20 Lactobacillus and 8 Bifidobacterium species examined, only Bifidobacterium breve ATCC 15700 was able to ferment starch from fava beans. Bifidobacterium breve ATCC 15700 and Lactobacillus rhamnosus GG ATCC 53103 were selected as probiotics for use in fresh-style Panela cheese. Two types of fresh cheese (with and without 3% fava bean starch) were manufactured with 3 combinations of probiotics: L. rhamnosus GG only, B. breve only, or both L. rhamnosus GG and B. breve. During 4 wk of storage at 4°C, the addition of fava bean starch to the cheese was not found to cause significant differences in the viability of either probiotic strain. However, the microstructure and texture of Panela cheese were altered, resulting in a much softer product. A sensory panel showed that the presence of added fava bean starch in Panela cheese was less desirable to consumers, whereas probiotic supplementation had no effect on perceived taste or appearance. Panela cheese could be a suitable food for inclusion of probiotic bacteria.

Pentoxifylline downregulates alpha (I) collagen expression by the inhibition of Ikappabalpha degradation in liver stellate cells.

Overproduction of collagen (I) by activated hepatic stellate cells is a critical step in the development of liver fibrosis. It has been established that these cells express interleukin (IL)-6 and respond to this cytokine with an increase in alpha(I) collagen. Pentoxifylline, a methylxanthine derivate, has been reported to have antifibrotic properties, but the mechanism responsible for this effect is unknown. The aim of this study was to determine the effect of pentoxifylline on acetaldehyde-induced collagen production in a rat hepatic stellate cell line (CFSC-2G cells). Cells were treated with 100 microM acetaldehyde and 200 microM pentoxifyline for 3 h. IL-6 and alpha(I) collagen messenger RNA (mRNA) were determined by reverse transcriptase polymerase chain reaction (RT-PCR) assay. NFkappaB activation was determined by electrophoretic mobility shift assay. To corroborate NFkappaB participation in pentoxifylline effect, cells were pretreated with 10 microM TPCK, a NFkappaB inhibitor. IkappaBalpha was determined by Western blot. IL-6 expression decreased significantly in acetaldehyde-pentoxifylline-treated cells. Acetaldehyde-treated cells pretreated with an anti-IL-6 monoclonal antibody did not show any increase in alpha (I) collagen expression. Acetaldehyde-treated cells increased 1.48 times NFkappaB activation, whereas acetaldehyde-pentoxifylline-treated cells decreased NFkappaB activation to control values. TPCK pretreated acetaldehyde cells did not present NFkappaB activation. To corroborate NFkappaB participation in pentoxifylline effect, IkappaBalpha was determined. IkappaBalpha protein level decreased 50% in acetaldehyde-treated cells, while acetaldehyde-pentoxifylline-treated cells showed IkappaBalpha control cells value. The data suggest that acetaldehyde induced alpha(I) collagen and IL-6 expression via NFkappaB activation. Pentoxifylline prevents acetaldehyde-induced alpha(I) collagen and IL-6 expression by a mechanism dependent on IkappaBalpha degradation, which in turn blocks NFkappaB activation.

Diversity of Colombian strains of Bacillus thuringiensis with insecticidal activity against dipteran and lepidopteran insects.

AIM: To evaluate the genetic and molecular diversity and insecticidal activity of Bacillus thuringiensis isolates from all the natural regions of Colombia. METHODS AND RESULTS: A total of 445 isolates from a collection of B. thuringiensis were characterized. The parasporal crystal morphology that was most abundant was bipyramidal (60%). Almost 10% of the isolates were toxic to Spodoptera frugiperda and 5.6% against Culex quinquefasciatus larvae. cry gene content determined by PCR indicated that 10.6% of the isolates contained cry1 genes and 1.1% contained cry2, cry4 or cry11 genes. Protein content of the parasporal crystal was determined by SDS-PAGE; 25 and 18 different protein profiles were found in isolates active against S. frugiperda and C. quinquefasciatus, respectively. CONCLUSIONS: Bacillus thuringiensis presents great genetic and molecular diversity even in isolates from the same soil sample. Moreover, the diversity and activity of the isolates might have a relationship with the geographical origin of the samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained here indicate that some of the B. thuringiensis isolates characterized in this study are potential control agents that could be used in programmes against mosquitoes and S. frugiperda.

[Myths about the prevention and control of non-communicable diseases in Latin America]. / Mitos sobre la prevención y el control de las enfermedades no transmisibles en América Latina.

Given the increase of the burden of non-communicable diseases (NCD) and the possibility to avoid it, it is urgent to implement or strengthen NCD preventive programs in Latin America. However, many myths hinder the implementation of NCD programs. Myths on NCD include: a) NCD are degenerative and incurable; b) they are diseases of the elderly; c) they are diseases of the rich. Like wise there are myths about NCD preventive programs are: a) difficult to implement, b) expensive, and c) ineffective. We present data that demonstrate how these myths are untrue and discuss the challenges to find a balanced health policy that emphasizes the importance of NCD without overlooking other diseases.

[Prevalence of hypertension in Valparaíso. Results of the base survey of the CARMEN project (Set of measures for the multifactorial reduction of non-transmissible diseases)]. / Prevalencia de hipertensión arterial en Valparaíso. Resultados de la encuesta de base del programa CARMEN (conjunto de acciones para la reducción multifactorial de las enfermedades no transmisibles).

BACKGROUND: There is little information about the real prevalence of hypertension in Chile. AIM: To assess the adjusted prevalence of hypertension and its main therapeutic measures among adults living in Valparaiso, Chile. MATERIALS AND METHODS: A random sample of dwellings in Valparaiso was chosen. Among these, an individual of 25 to 64 years old was randomly surveyed for risk factors for chronic diseases and sociodemographic parameters. Blood pressure, weight, height, oral glucose tolerance test, fasting cholesterol and triglycerides were also measured. Prevalence was pondered according to age, sex, and probability of selection in the dwelling interior. RESULTS: Three thousand one hundred twelve individuals were studied. The adjusted prevalence of hypertension was 11.4% (11.6% among females and 10.6% among men). The prevalence increased along with age from 3 and 1.9% in men and women of 25 to 34 years old respectively, to 18.2 and 27.4% among men and women of 55 to 64 years old (p < 0.01). People of low socioeconomic level had a higher prevalence of hypertension than those of high socioeconomic level (14.2 and 9.3% respectively, P < 0.05). Diabetes, obesity and hypercholesterolemia were significantly more frequent in subjects with hypertension than in the general population. Forty-four percent of diagnosed hypertensives were receiving medications (angiotensin converting enzyme inhibitors 40%, calcium antagonists 34%, beta blockers 22%). Twenty five percent of patients were treated with a combination of medications. Of those treated, only 22% had normal blood pressure levels at the moment of examination. CONCLUSIONS: High blood pressure is an important public health problem that requires more efficient detection and treatment programs.

[Risk factors for non communicable diseases: methods and global results of the CARMEN program basal survey]. / Factores de riesgo para las enfermedades no transmisibles: metodología y resultados globales de la encuesta de base del programa CARMEN (Conjunto de Acciones para la Reducción Multifactorial de las Enfermedades no Transmisibles).

BACKGROUND: In the last decades, chronic non communicable diseases are becoming the main cause of disability and mortality among adults. The risk factor surveillance and management is the most efficient mean of reducing the impact of these diseases. AIM: To report the results of a non communicable disease risk factor surveillance program in Valparaiso, Chile. MATERIAL AND METHODS: A random samples of people aged 25 to 64 years old living in Valparaiso, Chile was studied. Subjects were questioned about smoking and physical activity habits. Blood pressure, height and weight were measured using standardized techniques at their homes and blood samples were obtained to measure serum lipid levels and oral glucose tolerance test at the nearest outpatient clinic. RESULTS: Of the initial 3852 homes selected, 752 individuals did no agree to answer the inquiry, therefore 3120 subjects were finally interviewed. Of these, 40.6% were smokers, 15% drank alcohol in two or more occasions per month, 84.6% were physically inactive, 19.7% had a body mass index over 30 kg/m2, 11.1% had high blood pressure, 3.9% were diabetic and 46.9% had high serum cholesterol levels. CONCLUSIONS: The basal survey for the CARMEN program shows a high prevalence of cardiovascular risk factors among Chileans.

[Functional risk assessment of poor Chilean elders using an instrument validated in Canada]. / Medición del riesgo funcional en adultos mayores pobres, con un instrumento validado en Canadá.

BACKGROUND: Information about medical and social situation of elders is limited in Chile. AIM: To assess the functional risk of Chilean elders using an instrument validated in Canada. SUBJECTS AND METHODS: As part of a project aimed to help poor elders, 2,116 subjects living in Santiago, aged 65 to 99 years old (1,334 female, and 625 older than 75 years old), were interviewed. RESULTS: Thirty percent of these elders were using more than three medications and 13% lived alone. Visual problems were detected in 75%, memory problems were found in 62%, 63% felt depressed, 46% had hearing problems, 42% suffered a fall during the last year, 35% had a health problem that forced them to stay at home, 32% did not count with help in a case of need, 33% referred some type of nutritional problem, 26% needed help for daily living activities and 25% considered to have a worst health than counterparts of the same age. Among subjects older than 75 years old, the frequency of memory problems, auditory impairment, number of falls, health problems that precluded leaving the house, limitation for daily activities and the use of walking aids, was significantly higher. Although men and women had similar ages, men were in worst functional conditions, and had required more admissions to hospitals. There was a higher proportion of women living alone. Females also had a higher frequency of depression, memory disturbances, falls and use of more than three medications. CONCLUSIONS: Women elders tend to be in better functional conditions than men and people older than 75 years old have a higher functional risk. The applied instrument allowed a better focalization of our geriatric program.

[Professional role of the physician in health care]. / Rol profesional del médico en la atención de salud.

The professional role of the doctor in health care was analyzed in terms of the peculiarities of the chilean social reality. Determining factors include tradition, the expectations of society and demands of health policies. Action fields and primary and delegated functions are identified. This may be important to help prevent the take over of some of these functions by other health professionals.

[Changes in dehydrogenase glutamate in the rat brain caused by thyroid hormone deficiency]. / Alteraciones de la glutamato deshidrogenasa en áreas cerebrales de rata por deficiencia de hormonas tiroideas.

The dependent GDH-NADPH activity in adenohypophysis and other cerebral areas, has been studied in hypothyroid rats, in which hypothyroidism has been induced surgically. After thyroidectomy a decrease of GDH activity in limbic system (amygdala, septum and hippocampus), and an increase of this enzyme in cortex and hypothalamus have been found, with no changes in adenohypophysis. The alterations of GDH activity, induced by thyroidectomy, have been corrected, although not uniformly in the different brain areas after L-T3 treatment.