368 research outputs found
Evaluación histológica del efecto de enzimas con actividad depilatoria sobre piel vacuna
La industria curtidora genera una variedad de desechos potencialmente tóxicos que dependen del proceso de depilado utilizado. Para atenuar esta contaminación, se desarrollaron sistemas alternativos de depilado, entre ellos el enzimático. En la epidermis, a nivel del estrato corneo, se ubican lípidos que ocupan casi por completo el espacio intercelular entre los queratinocitos y desempeñan un importante papel como barrera hidrofóbica. Esta barrera debe transformarse para permitir el paso de las enzimas depilatorias hacia sus sitios de acción: folículo piloso/pelo y membrana basal. Las estructuras mencionadas deben eliminarse sin dañar el colágeno, proteína determinante de la calidad del cuero. Sobre trozos de piel bovina fueron analizados los efectos de diferentes pretratamientos tendientes a favorecer la penetración de enzimas depilatorias. Se utilizaron tensioactivos y sulfito de sodio como pretratamiento y posteriormente tratamientos con proteasas comerciales, una de origen pancréático y otra alcalina. El control fue tratado con buffer de bicarbonato de sodio. Las muestras se colorearon con Hematoxilina Eosina y Tricrómico de Masson. En los cortes sometidos a acción enzimática se encontraron cambios en el colágeno que podrían alterar la calidad del cuero.Se concluye que el estudio histológico de la piel permite evaluar los cambios que pueden ocasionar los tratamientos que se realizan para convertirla en cuero
Effect of Recovery Modality on Rate of Force Development, Vertical Jump, and Lactate Clearance
Please refer to the pdf version of the abstract located adjacent to the title
Interferencia del Herpesvirus equino 1 (EHV-1) en la apoptosis inducida
La apoptosis es un tipo de muerte celular programada que puede ser desencadenada por múltiples factores, tanto internos como externos; dentro de estos últimos se encuentran las infecciones virales.
Algunos alphaherpesvirus han desarrollado diversas estrategias para retardar o inhibir la muerte celular obteniendo, de esta manera, su propio beneficio al poder permanecer durante más tiempo en la célula.
Hasta el momento no se ha identificado ningún mecanismo relacionado con la modulación de la muerte celular durante la infección con Herpesvirus equino tipo 1 (EHV-1). El objetivo del presente trabajo fue describir el efecto producido por la infección con EHV-1 sobre cultivos celulares inducidos a la muerte por apoptosis. La evaluación de la apoptosis se realizó mediante el reconocimiento de la fragmentación en escalera del ADN, la evaluación de la relación Anexina V/ioduro de propidio (IP) y la determinación del clivaje de la citoqueratina 18, utilizando técnicas de inmunofluorescencia. Los resultados indican una posible interferencia del EHV-1 con la muerte por apoptosis hacia la mitad de su ciclo de replicación, que se incrementa hacia el final del mismo.Apoptosis is a programmed cell death that can be triggered by many factors, both internal and external. Viral infections are included among the latter. Some alphaherpesvirus have developed several strategies to retard or inhibit cell death and thus the virus benefits itself by staying longer in the cell. So far, no mechanisms have been identified related to modulation of cell death during infection with equine herpesvirus type 1 (EHV-1). The aim of the present study was to describe the effect produced by the infection with EHV-1 on apoptosis-induced cell cultures. Assessment of apoptosis was performed by DNA laddering, the Annexin V/propidium iodide (PI) determination and the cytokeratin 18 cleavage analysis using immunofluorescence techniques. Results indicate a possible interference of EHV-1 with apoptotic cell death in the middle of its replication cycle, being increased by its end
Circadian variation in the neoplasic hepatocytes proliferation from the ES 15 tumor
Como numerosos procesos biológicos, la proliferación de diversas poblaciones celulares animales presenta un ritmo circadiano. La respuesta diferencial a la ciclofosfamida ha sido relacionada con la periodicidad mitótica diaria en un carcinoma mamario de ratón. El presente trabajo analiza la evolución de la actividad mitótica, a lo largo de un ciclo de 24 h, de los hepatocitos neoplásicos del tumor E515 (hepatocarcinoma diferenciado, de crecimiento lento), 38 ratones machos, adultos de la cepa C3H/5, fueron injertados con el tumor en el tejido celular subcutáneo. Al cabo de 10 semanas los portadores fueron colocados durante tres semanas en condiciones de estandarización para análisis de periodicidad. Pasado ese lapso los mismos se repartieron en 6 lotes (n=5-8) que se sacrificaron cada 4 horas a partir de la hora 00:00 hasta abarcar un período de 24 h, tras recibir una dosis de Colchicina (2 µg/g/0,O1 ml). Las muestras del tumor se procesaron para observación microscópica bajo objetivo de inmersión. En los cortes se determinó por conteo mitótico el índice de metafases colchicínicas por 1.000 núcleos. Se observó que la actividad mitótica presenta su valor mínimo a las 04:00 horas y el máximo a las 16:00 h. Esta diferencia es estadísticamente significativa (P < 0,001). Este conocimiento es de utilidad para cualquier ensayo experimental que implique aspectos relacionados con la regulación del crecimiento del mismo tumor.As most of biological processes, the proliferation of a variety of mammalian cell populations shows a circadian rhythm. The differential response of a mouse mammary carcinoma to the endoxan (cyclophosphamide) administration, has been related to its daily mitotic periodicity. In this work we analyze the evolution of the mitotic activity, through a 24 h period, of the E515 tumor hepatocytes (Slow growing differentiated hepatocarcinoma). Thirty eight C3H/S inbred male adult mice, were grafted with the tumor in the hypodermis. Ten weeks later they were standardized for periodicity analysis during three weeks. After this time, they were separated in six groups (N=5-8) and one group every’ 4 h for a day was sacrificed. Four hours before killing, the mice received an IP injection of colchicine in a doses of 2 µg/g/0,O1 ml of distilled water. The colchicine metaphases were controlled on slides an the mitotic index per 1000 nuclei was determined. The lowest mitotic activity at 04:00 h and the highest at 16:O0 h were observed. The difference was highly significant (p < 0,001). The knowledge of this data is very useful for experimental assays related to any aspect of the same tumor growth regulation.Facultad de Ciencias Veterinaria
A silviculture-oriented spatio-temporal model for germination in Pinus pinea L. in the Spanish Northern Plateau based on a direct seeding experiment
Natural regeneration in Pinus pinea stands
commonly fails throughout the Spanish Northern Plateau
under current intensive regeneration treatments. As a
result, extensive direct seeding is commonly conducted to
guarantee regeneration occurrence. In a period of rationalization
of the resources devoted to forest management,
this kind of techniques may become unaffordable. Given
that the climatic and stand factors driving germination
remain unknown, tools are required to understand the
process and temper the use of direct seeding. In this study,
the spatio-temporal pattern of germination of P. pinea was
modelled with those purposes. The resulting findings will
allow us to (1) determine the main ecological variables
involved in germination in the species and (2) infer adequate
silvicultural alternatives. The modelling approach
focuses on covariates which are readily available to forest
managers. A two-step nonlinear mixed model was fitted to
predict germination occurrence and abundance in P. pinea
under varying climatic, environmental and stand conditions,
based on a germination data set covering a 5-year
period. The results obtained reveal that the process is primarily
driven by climate variables. Favourable conditions
for germination commonly occur in fall although the
optimum window is often narrow and may not occur at all
in some years. At spatial level, it would appear that germination
is facilitated by high stand densities, suggesting
that current felling intensity should be reduced. In accordance
with other studies on P. pinea dispersal, it seems that
denser stands during the regeneration period will reduce
the present dependence on direct seeding
Growth and yield of mixed versus pure stands of Scots pine (Pinus sylvestris L. ) and European beech (Fagus sylvatica L.) analysed along a productivity gradient through Europe
Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60-80 year-old trees and 0.02-1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520-1175 mm year−1), mean annual temperature (6-10.5 °C), and the drought index by de Martonne (28-61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.The networking in this study has been sup-ported by COST Action FP1206 EuMIXFOR. All contributors thanktheir national funding institutions to establish, measure, and analysedata from the triplets. The first author also thanks the BayerischenStaatsforsten (BaySF) for supporting the establishment of the plots,the Bavarian State Ministry for Nutrition, Agriculture, and Forestryfor permanent support of the project W 07 ‘‘Long-term experimentalplots for forest growth and yield research’’ (# 7831-22209-2013) andthe German Science Foundation for providing the funds for the pro-jects PR 292/12-1 ‘‘Tree and stand-level growth reactions on droughtin mixed versus pure forests of Norway spruce and European beech’’.Thanks are also due to Ulrich Kern for the graphical artwork, and totwo anonymous reviewers for their constructive criticism
Modelling the spatio-temporal pattern of primary dispersal in stone pine (Pinus pinea L.) stands in the Northern Plateau (Spain)
Natural regeneration in stone pine (Pinus pinea L.) managed forests in the Spanish Northern Plateau is
not achieved successfully under current silviculture practices, constituting a main concern for forest
managers. We modelled spatio-temporal features of primary dispersal to test whether (a) present low
stand densities constrain natural regeneration success and (b) seed release is a climate-controlled process.
The present study is based on data collected from a 6 years seed trap experiment considering different
regeneration felling intensities. From a spatial perspective, we attempted alternate established kernels
under different data distribution assumptions to fit a spatial model able to predict P. pinea seed rain. Due
to P. pinea umbrella-like crown, models were adapted to account for crown effect through correction of
distances between potential seed arrival locations and seed sources. In addition, individual tree fecundity
was assessed independently from existing models, improving parameter estimation stability. Seed rain
simulation enabled to calculate seed dispersal indexes for diverse silvicultural regeneration treatments.
The selected spatial model of best fit (Weibull, Poisson assumption) predicted a highly clumped dispersal
pattern that resulted in a proportion of gaps where no seed arrival is expected (dispersal limitation)
between 0.25 and 0.30 for intermediate intensity regeneration fellings and over 0.50 for intense fellings.
To describe the temporal pattern, the proportion of seeds released during monthly intervals was modelled
as a function of climate variables – rainfall events – through a linear model that considered temporal
autocorrelation, whereas cone opening took place over a temperature threshold. Our findings suggest
the application of less intensive regeneration fellings, to be carried out after years of successful seedling
establishment and, seasonally, subsequent to the main rainfall period (late fall). This schedule would
avoid dispersal limitation and would allow for a complete seed release. These modifications in present
silviculture practices would produce a more efficient seed shadow in managed stands
Integrated treatment of first episode psychosis with online training (e-learning): study protocol for a randomised controlled trial
BackgroundThe integrated treatment of first episode psychosis has been shown to improve functionality and negative symptoms in previous studies. In this paper, we describe a study of integrated treatment (individual psychoeducation complementary to pharmacotherapy) versus treatment as usual, comparing results at baseline with those at 6-month re-assessment (at the end of the study) for these patients, and online training of professionals to provide this complementary treatment, with the following objectives: 1) to compare the efficacy of individual psychoeducation as add-on treatment versus treatment as usual in improving psychotic and mood symptoms; 2) to compare adherence to medication, functioning, insight, social response, quality of life, and brain-derived neurotrophic factor, between both groups; and 3) to analyse the efficacy of online training of psychotherapists.Methods/designThis is a single-blind randomised clinical trial including patients with first episode psychosis from hospitals across Spain, randomly assigned to either a control group with pharmacotherapy and regular sessions with their psychiatrist (treatment as usual) or an intervention group with integrated care including treatment as usual plus a psychoeducational intervention (14 sessions). Training for professionals involved at each participating centre was provided by the coordinating centre (University Hospital of Álava) through video conferences. Patients are evaluated with an extensive battery of tests assessing clinical and sociodemographic characteristics (Positive and Negative Syndrome Scale, State-Trait Anxiety Inventory, Liebowitz Social Anxiety Scale, Hamilton Rating Scale for Depression, Scale to Assess Unawareness of Mental Disorders, Strauss and Carpenter Prognostic Scale, Global Assessment of Functioning Scale, Morisky Green Adherence Scale, Functioning Assessment Short Test, World Health Organization Quality of Life instrument WHOQOL-BREF (an abbreviated version of the WHOQOL-100), and EuroQoL questionnaire), and brain-derived neurotrophic factor levels are measured in peripheral blood at baseline and at 6 months. The statistical analysis, including bivariate analysis, linear and logistic regression models, will be performed using SPSS.DiscussionThis is an innovative study that includes the assessment of an integrated intervention for patients with first episode psychosis provided by professionals who are trained online, potentially making it possible to offer the intervention to more patients.Trial registrationNCT01783457 clinical trials.gov. Date of registration in primary registry 23 January 2013
The snow must go on: Ground ice encasement, snow compaction and absence of snow differently cause soil hypoxia, CO2 accumulation and tree seedling damage in boreal forest
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Apoptosis and cell proliferation in porcine placental vascularization
The placenta is a highly vascularized organ, indispensable tothe transfer of nutrients to the growing fetuses. During gestation, there exists an expansion of the placental vascular network through active angiogenesis. The aim of this research was to study cell proliferation and apoptosis through high resolution light microscopy (HRLM) and transmission electron microscopy (TEM) ultrastructure, immunohistochemistry for Ki67and caspase-3, determination of placental vascular area,and TUNEL assay. Crossbred sows placental tissues from approximately 30 ± 2(n =5), 40 ± 2(n =5), 60 ± 2 (n =5), 80 ± 2(n =5), 90 ± 2(n =5) and 114 ± 2(n =5) days of gestation were used. The evaluation of cell proliferation showed the highest%Ki67 values on days 30 ± 2 and 80 ± 2 of pregnancy. Caspase-3 expressed the highest value on day 30 ± 2, while the highest apoptotic indexes were found on days30 ± 2 and 90 ± 2. The placental vascular area was higher on day 80 ± 2 of pregnancy. According to our results, an active vascular cell remodeling by a caspase-3 dependent apoptosis seems to be present in early pregnancy. The increase in the vascular area on day 80 ± 2 would be the result of the intense vascular cell proliferation detected with Ki67. Further studies are needed to understand the complex processes of angiogenesis, cell proliferation and apoptosis that interact in the placenta during porcine gestation.Facultad de Ciencias Veterinaria
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