450 research outputs found
Biomarcadores etológicos no invasivos de estrés ambiental: estudio comparativo en dos teleosteos de ecosistemas de la región pampeana argentina
Mediante un dispositivo de registro automático se estudió el efecto de la exposición a soluciones subletales de Cd2+ (0.3 mg. L'1) sobre algunos parámetros etológicos de juveniles de Cyprinus carpió (carpa común) y de Astyanax fasciatus (“mojarra”). Se evaluó el efecto del metal sobre la actividad natatoria total y las preferencias altitudinales y laterales de los peces. Los tres parámetros se registraron simultáneamente mediante un dispositivo original. Se evaluaron los niveles “normales” o estándar de dichos parámetros (los peces en agua potable, control) y los alcanzados por los mismos individuos tras su exposición al tóxico de referencia (Cd). El metal provocó una depresión de la actividad natatoria total alcanzando una magnitud comparable en ambas especies. La preferencia altitudinal, también resultó modificada: C. carpió se halló con mayor frecuencia en la capa superior de los acuarios mientras que A. fasciatus se ubicó en las inferiores. En cuanto a la preferencia lateral, los individuos de ambas especies evitaron la franja vertical donde se producía el goteo de la solución de Cd; si bien esta respuesta espacial de los animales no siguió un patrón definido fue más marcada en las carpas. Todas las respuestas se pusieron de manifiesto inmediatamente después de haberse iniciado la exposición al Cd. El método resultó sensible y apto para el seguimiento de los parámetros etológicos seleccionados. Se concluye que la actividad natatoria y la ubicación espacial de las especies estudiadas, entre otros indicadores, pueden ser considerados como biomarcadores de toxicidad acuática.By means of an automatic recording device, the eífects of the exposure to sublethal Solutions of Cd2+ (0.3 mg. L2) on some ethological parameters of juvenile Cyprinus carpió (common carp) and Astyanaxfasciatus. The effect of the metal was evaluated through three parameters: the total swimming activity and the spatial (lateral and altitudinal) preferences, relative to Controls (fish kept in tap water); they were registered simultaneously by means oían original device. There were determined successively the “normal” or standard levels of those parameters in control fish and those reached by the same individuáis aftertheir exposure to thereferencetoxic (Cd).
In both species the metal caused a depression of the total swimming activity in a comparable magnitude. The altitudinal preference was also modified: C. carpió was found more frequently in the superior layer of the aquaria while A. fasciatus was found in the inferior ones. For the lateral preference, the individuáis of both species showed an avoidance behavior of the site of the aquaria where the Cd Solutions was dripping. This response of the animáis didn't follow a defined pattem, but was more marked in the carps. All the evaluated responses to the toxic were detected immediately after the beginning of the exposure to Cd. The method proved to be sensitive and apt for the monitoring of the measured behavioural parameters which makes it a promising tool for biomonitoring purposes. We concluded that the swimming activity and the spatial location preferences of the studied species, among other, may be considered as biomarkers of aquatic toxicity
Positive surgical margin during radical prostatectomy: overview of sampling methods for frozen sections and techniques for the secondary resection of the neurovascular bundles
Objective: The aim of the paper is to provide an overview of intraoperative sampling methods for frozen section (FS) analysis and of surgical techniques for a secondary neurovascular bundle (NVB) resection, as the method of surgical margin (SM) sampling and the management of a positive SM (PSM) at the nerve-sparing (NS) area are under evaluated issues. FS analysis during radical prostatectomy (RP) can help to tailor the plane of dissection based on cancer extension and thus extend the indications for NS surgery. Evidence Acquisition: We performed a PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Web of Science, Cochrane Library, and Elton B. Stephens Co. (EBSCO)host search to include articles published in the last decade, evaluating FS analysis in the NS area and surgical attempts to convert a PSM to a negative status. Evidence Synthesis: Overall, 19 papers met our inclusion criteria. The ways to collect samples for FS analysis included: systematic (analysing the whole posterolateral aspect of the prostate specimen, i.e., neurovascular structure-adjacent frozen-section examination [NeuroSAFE]); magnetic resonance imaging (MRI)-guided (biopsies from MRI-suspicious areas, retrieved by the surgeon in a cognitive way); and random biopsies from the soft periprostatic tissues. Techniques to address a PSM in the NS area included: full resection of the spared NVB, from its caudal to cranial aspect, often including the rectolateral part of the Denonvilliers’ fascia; partial resection of the NVB, in cases where sampling attempts to localise a PSM; incremental approach, meaning a partial or full resection that extends until no prostate tissue is found in the soft periprostatic environment. Conclusions: There is no homogeneity in prostate sampling for FS analysis, although most recent evidence is moving toward a systematic sampling of the entire NS area. The management of a PSM is variable and can be affected by the sampling strategy (difficult localisation of the persisting tumour at the NVB). The difficult identification of the exact soft tissue location contiguous to a PSM could be considered as the critical point of FS analysis and of spared-NVB management
Evaluación toxicológica no invasiva del cadmio: modificaciones de biomarcadores conductuales en <i>Cyprinus carpio</i>
Se describe un dispositivo que permite evaluar simultáneamente varios parámetros conductuales de peces en cautiverio. Se informan los resultados preliminares alcanzados al exponer juveniles (3-4 g) de la carpa común (Cyprinus carpio) a dos soluciones subletales de de Cd2+ (0.3 y 0.5 mg/L), determinándose los cambios en su actividad natatoria (expresada cuantitativamente mediante un Indice de actividad relativa, Ia) y en sus preferencias altitudinal y lateral en los acuarios. La actividad natatoria total se redujo significativamente a la concentración más elevada del metal, retornando a los niveles basales registrados en el período Control luego de transferir los peces a medio sin el metal. La preferencia altitudinal, resultó modificada, encontrándose que los peces expuestos al metal se hallaban la mayor cantidad de tiempo en la capa superior de los acuarios. En cuanto a la preferencia lateral el resultado más importante fue la evidencia de que los mismos peces evitaban la sección correspondiente al sitio de goteo de la solución de Cadmio, sin hallarse un patrón particular de distribución en el resto de las secciones de los acuarios. Los cambios en la actividad natatoria total y en la preferencia altitudinal de los peces fueron reversibles; en cambio, la alteración en la preferencia lateral no se modificó luego del reemplazo de las soluciones de Cd por medios limpios.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA
Evaluación toxicológica no invasiva del cadmio: modificaciones de biomarcadores conductuales en Cyprinus carpio
Se describe un dispositivo que permite evaluar simultáneamente varios parámetros conductuales de peces en cautiverio. Se informan los resultados preliminares alcanzados al exponer juveniles (3-4 g) de la carpa común (Cyprinus carpio) a dos soluciones subletales de de Cd2+ (0.3 y 0.5 mg/L), determinándose los cambios en su actividad natatoria (expresada cuantitativamente mediante un Indice de actividad relativa, Ia) y en sus preferencias altitudinal y lateral en los acuarios. La actividad natatoria total se redujo significativamente a la concentración más elevada del metal, retornando a los niveles basales registrados en el período Control luego de transferir los peces a medio sin el metal. La preferencia altitudinal, resultó modificada, encontrándose que los peces expuestos al metal se hallaban la mayor cantidad de tiempo en la capa superior de los acuarios. En cuanto a la preferencia lateral el resultado más importante fue la evidencia de que los mismos peces evitaban la sección correspondiente al sitio de goteo de la solución de Cadmio, sin hallarse un patrón particular de distribución en el resto de las secciones de los acuarios. Los cambios en la actividad natatoria total y en la preferencia altitudinal de los peces fueron reversibles; en cambio, la alteración en la preferencia lateral no se modificó luego del reemplazo de las soluciones de Cd por medios limpios.Trabajo presentado en II Jornadas sobre Ecología y Manejo de Ecosistemas Acuáticos Pampeanos (EMEAP) (La Plata, 2002)
Cambios en la velocidad de nado como indicador del efecto tóxico del cadmio en Astyanax fasciatus y Australoheros facetum
Numerous studies have shown that the swimming performance parameters of fish may be useful indicators of their environmental stress. The swimming speed was evaluated in two Pampean species and its alteration as a result of their exposure to sublethal Cadmium concentrations. The swimming speed was calculated from a daily registry of the distance and the time of displacement of fish by means of special software. Juveniles specimens of Astyanax fasciatus and Australoheros facetum were used in the assays; fish were acclimated during 7 days in aereated fresh-water (FW), at constant temperature (20 ± 1ºC) and photoperiod (12D:12N). The experimental design contemplated three successive periods: Control (4 days in FW), Exposure (4 days in FW + 0.3 and 0.5 mg Cd L-1) and Recovery (7 days in FW); simultaneously the speed of individuals maintained in FW during 15 days (CoP) was determined. The swimming speed in both species increased in the Exposure period. After transfer to clean media (Recovery period), the altered values in A. facetum, exhibited a slight tendency to recovery (but without reaching the basal values registered in the Control period). In A. fasciatus a clear cut recovery response was registered in fish exposed to 0.3 mg. L-1 while in animals exposed to the highest concentration of Cd no recovery was registered. These differences were interpreted as evidences of dissimilar uptake and depuration rates of the
toxic.Instituto de Limnología "Raúl A. Ringuelet
Cambios en la velocidad de nado como indicador del efecto tóxico del cadmio en Astyanax fasciatus y Australoheros facetum
Numerous studies have shown that the swimming performance parameters of fish may be useful indicators of their environmental stress. The swimming speed was evaluated in two Pampean species and its alteration as a result of their exposure to sublethal Cadmium concentrations. The swimming speed was calculated from a daily registry of the distance and the time of displacement of fish by means of special software. Juveniles specimens of Astyanax fasciatus and Australoheros facetum were used in the assays; fish were acclimated during 7 days in aereated fresh-water (FW), at constant temperature (20 ± 1ºC) and photoperiod (12D:12N). The experimental design contemplated three successive periods: Control (4 days in FW), Exposure (4 days in FW + 0.3 and 0.5 mg Cd L-1) and Recovery (7 days in FW); simultaneously the speed of individuals maintained in FW during 15 days (CoP) was determined. The swimming speed in both species increased in the Exposure period. After transfer to clean media (Recovery period), the altered values in A. facetum, exhibited a slight tendency to recovery (but without reaching the basal values registered in the Control period). In A. fasciatus a clear cut recovery response was registered in fish exposed to 0.3 mg. L-1 while in animals exposed to the highest concentration of Cd no recovery was registered. These differences were interpreted as evidences of dissimilar uptake and depuration rates of the
toxic.Instituto de Limnología "Raúl A. Ringuelet
Cambios en la velocidad de nado como indicador del efecto tóxico del cadmio en Astyanax fasciatus y Australoheros facetum
Numerous studies have shown that the swimming performance parameters of fish may be useful indicators of their environmental stress. The swimming speed was evaluated in two Pampean species and its alteration as a result of their exposure to sublethal Cadmium concentrations. The swimming speed was calculated from a daily registry of the distance and the time of displacement of fish by means of special software. Juveniles specimens of Astyanax fasciatus and Australoheros facetum were used in the assays; fish were acclimated during 7 days in aereated fresh-water (FW), at constant temperature (20 ± 1ºC) and photoperiod (12D:12N). The experimental design contemplated three successive periods: Control (4 days in FW), Exposure (4 days in FW + 0.3 and 0.5 mg Cd L-1) and Recovery (7 days in FW); simultaneously the speed of individuals maintained in FW during 15 days (CoP) was determined. The swimming speed in both species increased in the Exposure period. After transfer to clean media (Recovery period), the altered values in A. facetum, exhibited a slight tendency to recovery (but without reaching the basal values registered in the Control period). In A. fasciatus a clear cut recovery response was registered in fish exposed to 0.3 mg. L-1 while in animals exposed to the highest concentration of Cd no recovery was registered. These differences were interpreted as evidences of dissimilar uptake and depuration rates of the
toxic.Instituto de Limnología "Raúl A. Ringuelet
Ex vivo fluorescence confocal microscopy: prostatic and periprostatic tissues atlas and evaluation of the learning curve
Ex vivo fluorescence confocal microscopy (FCM) is an optical technology that provides fast H&E-like images of freshly excised tissues, and it has been mainly used for “real-time” pathological examination of dermatological malignancies. It has also shown to be a promising tool for fast pathological examination of prostatic tissues. We aim to create an atlas for FCM images of prostatic and periprostatic tissues to facilitate the interpretation of these images. Furthermore, we aimed to evaluate the learning curve of images interpretation of this new technology. Eighty fresh and unprepared biopsies obtained from radical prostatectomy specimens were evaluated using the FCM VivaScope® 2500 M-G4 (Mavig GmbH, Munich, Germany; Caliber I.D.; Rochester NY, USA) by two pathologists. Images of FCM with the corresponding H&E are illustrated to create the atlas. Furthermore, the two pathologists were asked to re-evaluate the 80 specimens after 90 days interval in order to assess the learning curve of images’ interpretation of FCM. FCM was able to differentiate between different types of prostatic and periprostatic tissues including benign prostatic glands, benign prostatic hyperplasia, high-grade intraepithelial neoplasm, and prostatic adenocarcinoma. As regards the learning curve, FCM demonstrated a short learning curve. We created an atlas that can serve as the base for urologists and pathologists for learning and interpreting FCM images of prostatic and periprostatic tissues. Furthermore, FCM images is easily interpretable; however, further studies are required to explore the potential applications of this new technology in prostate cancer diagnosis and management
Unemployment Insurance and Low-Educated Single Working Mothers Before and After Welfare Reform
Using the Survey of Income and Program Participation (SIPP), a nationally representative, longitudinal survey, this study examines changing levels of Unemployment Insurance (UI) eligibility and benefit receipt among working low-educated single mothers, 1990–2005. It also examines changing participation in cash welfare and the Food Stamp Program (FSP). Relative to single childless women, there has been no increase in UI benefit receipt among single mothers entering a spell of unemployment in the postreform period, even though single mothers have increased their relative rates of UI eligibility. Because of declining cash assistance receipt, UI became a more common income support than cash assistance for this population during the period 2001–2005. Furthermore, the probability of accessing FSP for low-educated single mothers entering a spell of unemployment increased in the years 2001–2005. As a result, the proportion of this population accessing benefits from one or more of these programs remained virtually unchanged across the study period
Access and utilisation of primary health care services comparing urban and rural areas of Riyadh Providence, Kingdom of Saudi Arabia
The Kingdom of Saudi Arabia (KSA) has seen an increase in chronic diseases. International evidence suggests that early intervention is the best approach to reduce the burden of chronic disease. However, the limited research available suggests that health care access remains unequal, with rural populations having the poorest access to and utilisation of primary health care centres and, consequently, the poorest health outcomes. This study aimed to examine the factors influencing the access to and utilisation of primary health care centres in urban and rural areas of Riyadh province of the KSA
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