Arylamidase activity of soils

The enzyme amino acid arylamidase [alpha-aminoacyl-peptide hydrolyze (microsomal) EC 3.4.11.2] catalyzes the release of an N-terminal amino acid from peptides, amides or arylamides. This enzyme is important in N mineralization in soils, because it is involved in the release of amino acids bound to the soil organic matter. The detection of arylamidase in soils is reported, and a precise and accurate method is described for its assay. It involves colorimetric determination of the beta-naphthylamine produced when soil is incubated with L-leucine beta-naphthylamide in 0.1 M THAM buffer (pH 8.0) at 37°C for 1 h. The beta-naphthylamine is extracted with ethanol and reacted with p-dimethylaminocinnamaldehyde to produce an azo compound, the absorbance of which is measured at 540 nm. This enzyme has its optimal activity at pH 8.0 and is inactivated at temperatures above 60°C. The Km values of this enzyme in seven surface soils ranged from 0.19 to 0.35 mM. The activation energy values ranged from 30.6 to 49.8 kJ mol-1 for field-moist soils and from 26.2 to 32.4 kJ mol-1 for their air-dried counterparts. The means of Q10 ranged from 1.32 to 1.71 (avg. = 1.44). Treating soils with toluene, formaldehyde, dimethylsulfoxide, HgCl2, or iodoacetic acid inhibited, and autoclaving completely destroyed, the activity of this enzyme in soils. At 5 mumol g--1 soil, arylamidase activity was inhibited in both air-dried and field-moist samples by 18 of 25 trace elements tested; Ag (I), Hg (II), and Cd (II) were the most effective inhibitors. Co (II), Mg (II), Mn (II), B (III) and As (V) activated this enzyme in field-moist soils and their air-dried counterparts, and W (VI) and Mo (VI) activated this enzyme in air dried soils, but inhibited it in the field-moist soils. The activity of this enzyme in soils was significantly correlated with activities of L-asparaginase (r = 0.91; P \u3c 0.001), L-aspartase (r = 0.90; P \u3c 0.001), urease (r = 0.87; P \u3c 0.001), L-glutaminase (r = 0.84; P \u3c 0.001) and amidase (r = 0.39; P \u3c 0.01). Using substrates containing different amino add moieties showed that the activity of arylamidase decreased as follows: alanine \u3e leucine \u3e serine \u3e lysine\u3e arginine = glycine = histidine \u3e proline (not hydrolyzed). The activity of arylamidase was significantly affected by tillage and crop residue placements. Lime application rate (pH range 4.9 to 6.9) significantly affected the activities of 14 enzymes, including arylamidase, involved in C, N, P, and S cycling

SOIL MICROBIAL COMMUNITIES AS AFFECTED BY A COMMERCIAL ORGANIC FERTILIZER AND SUNN HEMP AS A COVER CROP IN ORGANIC SWEET PEPPER PRODUCTION IN PUERTO RICO

SOIL MICROBIAL COMMUNITIES AS AFFECTED BY A COMMERCIAL ORGANIC FERTILIZER AND SUNN HEMP AS A COVER CROP IN ORGANIC SWEET PEPPER PRODUCTION IN PUERTO RIC

Violencia cotidiana e invisible hacia las mujeres diálogos desde los (micromachismos)

En esta investigación se abordaron las construcciones sociales de mujeres y hombres en Bogotá acerca de la violencia sutil hacia las mujeres o micromachismos . Para lograr lo anterior se utilizó una metodología cualitativa de enfoque socioconstruccionista y se realizaron diálogos generativos con cuatro grupos de personas de edades entre 18 y 96 años de sectores socioeconómicos medio-alto. Se encontró que en Colombia la violencia sutil, cotidiana e invisible contra las mujeres no tiene una denominación específica, lo cual contribuye a la perpetuación de prácticas patriarcales sutiles que favorecen que se sigan propiciando estos y otros tipos de violencia hacia las mujeres. Además, se encontró que en cada grupo hubo participantes que identificaron la presencia de los distintos tipos de micromachismos en sus vidas y el impacto que estos generan, a pesar del hecho de que la mayoría de los participantes no lo consideraba como un tipo de violencia hasta el diálogo realizado. Adicionalmente, algunos de los participantes postularon diversas alternativas para la disminución de este tipo de violencia, predominando la importancia del cambio de patrones generacionales patriarcales.The present investigation approached the social constructions of men and women from the city of Bogotá achieve in relation to the subtle and invisible violence or micromachismos . In order to achieve this, a qualitative methodology with a social constructionism approach was used, and generative dialogues were carried out with four groups of people of ages between 18 and 96 years old from a medium-high socioeconomic sector. The researchers found that in Colombia the subtle, quotidian and invisible violence against women does not have a specific name, which contributes to the reproduction of subtle patriarchal practices that assists this and other types of violence against women. Besides, in every group there were participants that identified the presence of the different types of micromachismos in their lives and the impact they produce, despite the fact that most of the participants had not considered the micromachismos as a type of violence before the generative dialogue. In addition, some of the participants proposed several alternatives for the decrease of this type of violence, prevailing the importance of changing generational patriarchal patterns.Psicólogo (a)Pregrad

Large-area biomolecule nanopatterns on diblock copolymer surfaces for cell adhesion studies

Cell membrane receptors bind to extracellular ligands, triggering intracellular signal transduction pathways that result in specific cell function. Some receptors require to be associated forming clusters for effective signaling. Increasing evidences suggest that receptor clustering is subjected to spatially controlled ligand distribution at the nanoscale. Herein we present a method to produce in an easy, straightforward process, nanopatterns of biomolecular ligands to study ligand–receptor processes involving multivalent interactions. We based our platform in self-assembled diblock copolymers composed of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) that form PMMA nanodomains in a closed-packed hexagonal arrangement. Upon PMMA selective functionalization, biomolecular nanopatterns over large areas are produced. Nanopattern size and spacing can be controlled by the composition of the block-copolymer selected. Nanopatterns of cell adhesive peptides of different size and spacing were produced, and their impact in integrin receptor clustering and the formation of cell focal adhesions was studied. Cells on ligand nanopatterns showed an increased number of focal contacts, which were, in turn, more matured than those found in cells cultured on randomly presenting ligands. These findings suggest that our methodology is a suitable, versatile tool to study and control receptor clustering signaling and downstream cell behavior through a surface-based ligand patterning technique

Towards an eco-friendly coffee rust control : compilation of natural alternatives from a nutritional and antifungal perspective

Hemileia vastatrix (HV) is the pathogen responsible for the coffee leaf rust (CLR) disease that has spread globally. CLR causes losses of up to a billion dollars annually and affects all types of crops regardless of their production regime (organic or inorganic). Additionally, smallholders produce approximately 80% of coffee in developing countries. The condition causes losses of up to a billion dollars annually. It affects all types of crops regardless of their production regime (organic or inorganic). Approximately 80% of coffee is produced by smallholders in developing countries. Until the 90s, shaded-production systems and native varieties were encouraged; however, the rapid spread of CLR has forced farmers to migrate towards inorganic schemes, mainly due to a lack of knowledge about natural alternatives to pesticides that can be implemented to control HV. Therefore, the purpose of this article is to compile the currently existing options, emphasizing two key factors that guarantee efficient rust control: selective fungicidal activity against HV and the nutrition of coffee crops. Thus, by comprehending how these natural compounds (such as plant, bacteria, fungi, animals, or algae metabolites) impact coffee rust proliferation. Furthermore, since a various range of biochar effects contributes to the control of foliar fungal pathogens through modification of root exudates, soil properties, and nutrient availability, which influence the growth of antagonist microorganisms, we present a review of the pathogen-suppressive effects of biochar, and new control strategies suitable for organic schemes can be developed.Publisher PDFPeer reviewe

Calculation of the carrying capacity and multi-criteria tourist reception capacity for the El Encenillo biological reserve, Guasca-Cundinamarca, Colombia

La presente investigación tiene como objetivo principal realizar una comparación entre dos metodologías para calcular el número máximo de visitantes que pueden ingresar diariamente a un área natural en donde se realiza turismo, para establecer las fortalezas y debilidades de cada una. Como caso de estudio se seleccionó la reserva Biológica El Encenillo ubicada en el municipio de Guasca, departamento de Cundinamarca – Colombia. Las metodologías utilizadas fueron la Capacidad De Carga Turística (CCT), ampliamente utilizada, pero que en la actualidad ha ido cayendo en desuso y se le tacha de subjetiva y el Cálculo de Acogida Turística Multicriterio – CATUM, que sigue un método basado en la ponderación de los factores de corrección mediante el Proceso Analítico Jerárquico (Analytic Hierarchy Process - AHP), aplicado en 3 niveles de consulta: Sui validatio, Scientatis validatio y Societatis validatio, como mecanismo para reducir la subjetividad.The main objective of this research is to carry out a comparison between two methodologies to calculate the maximum daily number of visitors that can enter a natural area where tourism is carried out, to establish the strengths and weaknesses of each of them. The biological reserve El Encenillo was selected as a case study. It is located in the municipality of Guasca, department of Cundinamarca - Colombia. The methodologies used were the Tourist Carrying Capacity (CCT), which was formerly widely used, but has now fallen into disuse and is considered to be subjective, and the Multi-criteria Tourism Hosting Calculation, which follows a method based on the weighting of correction factors through the Analytic Hierarchy Process (AHP), applied at 3 levels of consultation: Sui validatio, Scientatis validatio and Societatis validatio, as a mechanism to reduce subjectivity

Hypothermia prevents gliosis and angiogenesis development in an experimental model of ischemic proliferative retinopathy

PURPOSE: To develop a time course study of vascularization and glial response to perinatal asphyxia in hypoxic-ischemic animals, and to evaluate hypothermia as possible protective treatment. METHODS: We used retinas of 7-, 15-, 21-, and 30-day-old male Sprague-Dawley rats that were exposed to perinatal asphyxia at either 37°C (PA) or 15°C (HYP). Born to term animals were used as controls (CTL). We evaluated the thickness of the most inner layers of the retina (IR), including internal limiting membrane, the retinal nerve fiber layer, and the ganglion cell layer; and studied glial development, neovascularization, adrenomedullin (AM), and VEGF by immunohistochemistry, immunofluorescence, and Western blot. RESULTS: A significant increment in IR thickness was observed in the PA group from postnatal day (PND) 15 on. This alteration was concordant with an increased number of new vessels and increased GFAP expression. The immunolocalization of GFAP in the internal limiting membrane and perivascular glia of the IR and in the inner processes of Müller cells was coexpressed with AM, which was also significantly increased from PND7 in PA animals. In addition, VEGF expression was immunolocalized in cells of the ganglion cell layer of the IR and this expression significantly increased in the PA group from PND15 on. The retinas of the HYP group did not show differences when compared with CTL at any age. CONCLUSIONS: This work demonstrates that aberrant angiogenesis and exacerbated gliosis seem to be responsible for the increased thickness of the inner retina as a consequence of perinatal asphyxia, and that hypothermia is able to prevent these alterations.Fil: Rey Funes, Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: Dorfman, Verónica Berta. Universidad Maimónides. Area de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ibarra, Mariano Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: Peña, Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: Contartese, Daniela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: Goldstein Raij, Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Acosta, Juan Manuel. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larráyoz, Ignacio M.. Centro de Investigación Biomédica de La Rioja; EspañaFil: Martínez Murillo, Ricardo. Consejo Superior de Investigaciones Cientificas; España. Instituto Cajal. Departamento de Neurobiología Molecular, Celular y del Desarrollo; EspañaFil: Martínez, Alfredo. Centro de Investigación Biomédica de La Rioja; España. Consejo Superior de Investigaciones Cientificas; EspañaFil: Loidl, Cesar Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; Argentin

Efecto de paricalcitol sobre el metabolismo mineralóseo en pacientes trasplantados renales con hiperparatiroidismo secundario

ResumenIntroducciónEl hiperparatiroidismo secundario es muy prevalente en pacientes trasplantados renales. Cursa con frecuencia con hipercalcemia y se ha asociado al desarrollo de osteopenia y fracturas óseas. El paricalcitol ha mostrado su eficacia en el control del hiperparatiroidismo secundario en la enfermedad renal crónica con y sin diálisis, con una baja incidencia de hipercalcemia. La experiencia con paricalcitol en trasplantados renales es muy escasa. El objetivo de este trabajo fue mostrar el efecto sobre el metabolismo mineralóseo del paricalcitol en trasplantados renales con hiperparatiroidismo secundario.Material y métodosEstudio retrospectivo multicéntrico con trasplantados renales de más de 18 años de edad y más de 12 meses de evolución postrasplante, con función renal estable, que hayan sido tratados con paricalcitol durante más de 12 meses, con seguimiento clínico hasta los 24 meses de tratamiento.ResultadosSe incluyó a 69 pacientes, con 120±92 meses postrasplante, con creatinina inicial de 2,2±0,9mg/dl y FG-MDRD 36±20ml/min/1,73 m2. La dosis de paricalcitol se incrementó progresivamente durante el estudio: basal 3,8±1,9μg/semana, 12 meses 5,2±2,4μg/semana; 24 meses 6,0±2,9μg/semana (p<0,001). Los niveles séricos de PTH descendieron de forma rápida y significativa: basal 288±152 pg/ml; 6 meses 226±184 pg/ml; 12 meses 207±120; 24 meses 193±119 pg/ml (p<0,001). Observamos una reducción sobre PTH basal ≥30% en el 42,4% de los pacientes a los 12 meses y en el 65,2% de los pacientes a los 24 meses. La fosfatasa alcalina descendió también significativamente en los 6 primeros meses para luego estabilizarse: basal 92±50 UI/l; 6 meses 85±36 UI/l, 12 meses 81±39 UI/l (p<0,001). Globalmente no hubo modificaciones en el calcio o fósforo séricos ni en la excreción urinaria de calcio. La reducción de PTH fue más importante en trasplantados con niveles séricos más elevados de partida. Observamos que los pacientes con calcio basal más bajo mostraron un incremento significativo de sus cifras de 0,5-0,6mg/dl en promedio aunque manteniéndose en rango de normalidad, mientras que pacientes con calcio basal>10mg/dl mostraron una reducción progresiva de sus cifras. Quince (21,7%) pacientes seguían tratamiento previo con calcitriol y al cambiarlos a paricalcitol precisaron dosis significativamente mayores que los pacientes que no habían recibido calcitriol. El paricalcitol fue asociado a cinacalcet en 11 pacientes, con reducciones significativas de PTH, con evolución similar al resto de la población y con dosis de paricalcitol también similares.ConclusionesParicalcitol es eficaz en el tratamiento del hiperparatiroidismo secundario de trasplantados renales. Globalmente no observamos modificaciones significativas de los niveles de calcio ni de fósforo, ni en su excreción urinaria. Los pacientes en tratamiento previo con calcitriol precisaron dosis mayores de paricalcitol. Cuando el paricalcitol se administra a pacientes tratados con cinacalcet, se observa un descenso significativo de la PTH con dosis de paricalcitol similar a pacientes sin cinacalcet.AbstractIntroductionSecondary hyperparathyroidism is highly prevalent in kidney transplant recipients, and commonly results in hypercalcaemia; an association to osteopenia and bone fractures has also been observed. Paricalcitol has proved effective to control secondary hyperparathyroidism in chronic kidney disease in both dialysed and non-dialysed patients, with a low hypercalcaemia incidence. Currently available experience on paricalcitol use in kidney transplant recipients is scarce. Our main aim was to show the effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism.Material and methodsA retrospective multicentre study in kidney transplant recipients aged>18 years with a 12-month or longer post-transplantation course, stable renal function, having received paricalcitol for more than 12 months, with available clinical follow-up for a 24-month period.ResultsA total of 69 patients with a 120 ± 92-month post-transplantation course were included. Baseline creatinine was 2.2±0.9mg/dl y GFR-MDRD was 36±20ml/min/1.73m2. Paricalcitol doses were gradually increased during the study: baseline 3.8±1.9μg/week, 12 months 5.2±2.4μg/week; 24 months 6.0±2.9μg/week (P<.001). Serum PTH levels showed a significant fast decline: baseline 288±152 pg/ml; 6 months 226±184 pg/ml; 12 months 207±120; 24 months 193±119 pg/ml (P<.001). Reduction from baseline PTH was ≥30% in 42.4% of patients at 12 months y in 65.2% of patients at 24 months. Alkaline phosphatase showed a significant decrease in first 6 months followed by a plateau: baseline 92±50 IU/l; 6 months 85±36 IU/l, 12 months 81±39 IU/l (P<.001). Overall, no changes were observed in serum calcium and phosphorus, and in urine calcium excretion. PTH decline was larger in patients with higher baseline levels. Patients with lower baseline calcium levels showed significantly increased levels (mean increase was 0.5-0.6mg/dl) but still within normal range, whereas patients with baseline calcium>10mg/dl showed gradually decreasing levels. Fifteen (21.7%) patients had received prior calcitriol therapy. When shifted to paricalcitol, such patients required paricalcitol doses significantly larger than those not having received calcitriol. Paricalcitol was used concomitantly to cinacalcet in 11 patients with significant PTH reductions being achieved; clinical course was similar to other patients and paricalcitol doses were also similar.ConclusionsParicalcitol is an effective therapy for secondary hyperparathyroidism in kidney transplant recipients. Overall, no significant changes were observed in calcium and phosphorus levels or urinary excretion. Patients having previously received calcitriol required higher paricalcitol doses. When used in patients receiving cinacalcet, paricalcitol results in a significant PTH fall, with paricalcitol doses being similar to those used in patients not receiving cinacalcet

Carcinoma Papilar de localización Extratiroidea presentación de Un Caso Clínico: Papillary carcinoma extra thyroids areas. Ity a case report

El carcinoma de tiroides originado en tejido tiroideo ectópico es una entidad clínica poco común en la actualidad; la incidencia notificada es 1 de cada 100.000 a 300.000 en la población general. Estas anomalías se clasifican en ectopias tiroideas clásicas y en ectopias tiroideas accesorias dependiendo de si se ubican o no en la línea de descenso embrionario del primordio tiroideo (10) (11). Se estima que se presenta en 1 de cada 200.000 personas, cifra que puede aumentar considerablemente hasta 1 de cada 6.000 pacientes con enfermedad tiroidea. De las formas clásicas, la ubicación lingual es la más común (80 a 90 %) 4,5 y, en estos casos, el tejido ectópico constituye el único esbozo funcional de la glándula 6-8. El quiste del conducto tirogloso, también denominado tejido tiroideo ectópico sublingual, se presenta en 2 a 3 % de los casos. El hallazgo de una lesión maligna en un verdadero tejido tiroideo aberrante es inusual. Ante su poca frecuencia de esta patología se presenta un paciente de sexo masculino residente de la ciudad de Ibarra y tratado en la Unidad Oncológica Solca Imbabura (UOSI), el cual consulta por una masa en región cervical derecha de aproximadamente 6 cm de diámetro por lo que fue sometido a cirugía exeresis de masa, con resultado histopatológico de carcinoma papilar tiroideo derivado de tejido tiroideo ectópico cervical lateral. Por lo que el paciente requirió nueva intervención quirúrgica para tiroidectomía total con vaciamiento ganglionar según protocolos en UOSI. Posteriormente el paciente necesito terapia con yodo radioactivo para control de su enfermedad