111 research outputs found

    Estado de condición de los juveniles de Gobius cobitis (Pallas, 1811) en la laguna costera del Mar Menos (SE Península Ibérica): efectos de la competencia inter- e intraespecífica en peces

    Get PDF
    We investigated the relationships, at a local level, between fish condition and environmental variables in Gobius cobitis juveniles. The relationships between 14 ecological variables of shallow areas of the Mar Menor coastal lagoon (water temperature, water salinity, depth, submerged vegetation richness, submerged vegetation cover, submerged vegetation volume, substrate size, substrate heterogeneity, fish species richness, potential competitor fish species abundance and biomass, G. cobitis abundance and biomass, G. cobitis biomass/abundance ratio) and fish condition were analysed. The mass-length relationship of juveniles was used to test differences in fish condition between 12 sampling sites. The ecological variables that accounted for most of the variation in fish condition were related to both inter- and intraspecific fish competition.Se investigaron las relaciones, a nivel de localidad, entre el estado de condición de los juveniles de Gobius cobitis y las variables del hábitat. Fueron analizadas las relaciones entre 14 variables del habitat de las zonas someras de la laguna costera del Mar Menor (temperatura del agua, salinidad, profundidad, riqueza de especies de vegetación subacuática, cobertura de la vegetación subacuática, volumen de la vegetación subacuática, granulometría del sustrato, heterogeneidad del sustrato, riqueza de especies de peces, abundancia y biomasa de especies potencialmente competidoras, abundancia y biomasa de G. cobitis, relación biomasa/abundancia de G. cobitis) y el estado de condición de los peces. Las relaciones peso-longitud de los juveniles fueron utilizadas para testar las diferencias en el estado de condición de los peces entre las 12 localidades de muestreo. Las variables del habitat que explicaron la mayor variación en la condición fueron variables relacionadas con la competencia inter- e intraespecífica en peces.

    Biología trófica de los juveniles del género Liza (Pisces : Mugilidae) en la laguna costera del Mar Menor (SE Península Ibérica)

    Get PDF
    En el presente trabajo se presentan datos sobre la alimentación de juveniles de tres especies de mugílidos presentes en la laguna costera del Mar Menor: Liza saliens (Risso, 1810), L. aurata (Risso, 1810) y L. ramado (Risso, 1810). La dieta fue omnívora para las tres especies, consumiendo una gran variedad de presas, tanto de origen animal como vegetal. Se encontraron diferencias interespecíficas en la composición de la misma, así como diferencias intraespecíficas en función de la campaña de muestreo. Además, se observaron cambios en la dieta en función de la talla de los ejemplares, situación probablemente relacionada con cambios ontogénicos en la dieta de las especies estudiadas.In this work data is presented concerning the food and feeding habits of three species of mullet juveniles that are present in the Mar Menor coastal lagoon: Liza saliens (Risso, 1810), L. aurata (Risso, 1810) and L. ramado (Risso, 1810). Diet of of the three species was omnivorous; they fed on numerous prey items, both animal and vegetal preys. Interspecific differences on diet composition were found, as well as intraspecific differences from sampling periods. Moreover, size-related differences in their feeding habits were found, suggesting the existence of ontogenic changes in the diet of the studied species

    Biología poblacional y asociaciones con el hábitat de las especies de peces bentónicas en las áreas someras de una laguna costera mediterránea (SE Península Ibérica)

    Get PDF
    The present study investigates the seasonal variation in fish abundance, fish biomass, reproductive status and population structure of four dominant benthic fish species, Salaria pavo, Pomatoschistus marmoratus, Gobius cobitis and Gobius niger, in the shallow and littoral areas of the Mar Menor coastal lagoon. In addition, the seasonal habitat associations of each species were studied by assessing environmental variables related to the habitat structure: submerged vegetation cover, submerged vegetation density, water depth and substrate composition. The temporal variations in fish density, standing stock and size frequency distributions of these species can largely be attributed to the seasonality of their breeding and juvenile recruitment periods. Moreover, habitat associations for these species were similar to those obtained in other Mediterranean and Atlantic coastal lagoons.En el presente estudio se investigaron las variaciones estacionales de la abundancia, la biomasa, status reproductor y la estructura de la población de cuatro especies de peces bentónicos dominantes, Salaria pavo, Pomatoschistus marmoratus, Gobius cobitis y Gobius niger, en las zonas someras y litorales de la laguna costera del Mar Menor. Además, se estudiaron las asociaciones con las variables del hábitat: cobertura y densidad de la vegetación subacuática, profundidad y tipo de sustrato, para cada una de las especies y en cada estación del año. Las variaciones estacionales en la abundancia, la biomasa y la estructura por tallas de estas especies pueden ser atribuidas a sus periodos de reproducción y el reclutamiento de juveniles. Las asociaciones con las variables del hábitat para todas las especies fueron similares a las encontradas en otras lagunas costeras Mediterráneas y Atlánticas

    Xeroderma pigmentosum group D 751 polymorphism as a predictive factor in resected gastric cancer treated with chemo-radiotherapy

    Get PDF
    AIM: To evaluate the potential association of xeroderma pigmentosum group D (XPD) codon 751 variant with outcome after chemo-radiotherapy in patients with resected gastric cancer. METHODS: We used PCR-RFLP to evaluate the genetic XPD Lys751Gln polymorphisms in 44 patients with stage III (48%) and IV (20%) gastric cancer treated with surgery following radiation therapy plus 5-fluorouracil/ leucovorin based chemotherapy. RESULTS: Statistical analysis showed that 75% (12 of 16) of relapse patients showed Lys /Lys genotype more frequently (P = 0.042). The Lys polymorphism was an independent predictor of high-risk relapse-free survival from Cox analysis (HR: 3.07, 95% CI: 1.07-8.78, P = 0.036) and Kaplan-Meir test (P = 0.027, log-rank test). CONCLUSION: XPD Lys751Gln polymorphism may be an important marker in the prediction of clinical outcome to chemo-radiotherapy in resected gastric cancer patients

    Identification by Real-time PCR of 13 mature microRNAs differentially expressed in colorectal cancer and non-tumoral tissues

    Get PDF
    MicroRNAs (miRNAs) are short non-coding RNA molecules playing regulatory roles by repressing translation or cleaving RNA transcripts. Although the number of verified human miRNA is still expanding, only few have been functionally described. However, emerging evidences suggest the potential involvement of altered regulation of miRNA in pathogenesis of cancers and these genes are thought to function as both tumours suppressor and oncogenes. In our study, we examined by Real-Time PCR the expression of 156 mature miRNA in colorectal cancer. The analysis by several bioinformatics algorithms of colorectal tumours and adjacent non-neoplastic tissues from patients and colorectal cancer cell lines allowed identifying a group of 13 miRNA whose expression is significantly altered in this tumor. The most significantly deregulated miRNA being miR-31, miR-96, miR-133b, miR-135b, miR-145, and miR-183. In addition, the expression level of miR-31 was correlated with the stage of CRC tumor. Our results suggest that miRNA expression profile could have relevance to the biological and clinical behavior of colorectal neoplasia

    A gene signature of 8 genes could identify the risk of recurrence and progression in Dukes' B colon cancer patients

    Get PDF
    The benefit of postoperative adjuvant chemotherapy in patients with Dukes' B colorectal cancer is still uncertain and its routine use is not recommended. The five-year relapse rate is approximately 25-40% and the identification of patients at high risk of recurrence would represent an important strategy for the use of adjuvant chemotherapy. We retrospectively analyzed gene expression profiles in frozen tumor specimens from patients with Dukes' B colorectal cancer by using high density oligonucleotide microarrays. Our results show a subset of 48 genes differentially expressed with an associated probability <0.001 in the t-test. Another statistical procedure based on the Fisher criterion resulted in 11 genes able to separate both groups. We selected the 8 genes present in both subsets. The differential expression of five genes (CHD2, RPS5, ZNF148, BRI3 and MGC23401) in colon cancer progression was confirmed by real-time PCR in an independent set of patients of Dukes' B and C stages

    Expression profiles of adult T-cell leukemia-lymphoma and associations with clinical responses to zidovudine and interferon alpha

    Get PDF
    Adult T-cell leukemia-lymphoma (ATLL) is an HTLV-1-associated lymphoproliferative malignancy that is frequently fatal. We compared gene expression profiles (GEPs) of leukemic specimens from nine patients with ATLL at the time of diagnosis and immediately after combination therapy with zidovudine (AZT) and interferon alpha (IFNalpha). GEPs were also related to genetic aberrations determined by comparative genomic hybridization. We identified several genes anomalously over-expressed in the ATLL leukemic cells at the mRNA level, including LYN, CSPG2, and LMO2, and confirmed LMO2 expression in ATLL cells at the protein level. In vivo AZT-IFNalpha therapy evoked a marked induction of interferon-induced genes accompanied by repression of cell-cycle regulated genes, including those encoding ribosomal proteins. Remarkably, patients not responding to AZT-IFNalpha differed most from responding patients in lower expression of these same IFN-responsive genes, as well as components of the antigen processing and presentation apparatus. Demonstration of specific gene expression signatures associated with response to AZT-IFNalpha therapy may provide novel insights into the mechanisms of action in ATLL

    Edad y crecimiento de Gobio lozanoi Doadrio & Madeira, 2004 (Cypriniformes: Cyprinidae) en sectores fluviales de la cuenca del río Segura (SE península ibérica)

    Get PDF
    El trabajo estudia la estructura de edad, longitud retrocalculada y tasa de crecimiento en poblaciones de Gobio lozanoi a lo largo de los principales ejes fluviales de la cuenca del río Segura (ríos Se- gura y Mundo). Se analizaron estos parámetros con individuos capturados en otoño de 2009 y en 19 localidades, así como su re- lación con variables ambientales (altitud, estado ecológico y con- ductividad). Las poblaciones reflejaron seis clases de edad (0+ a 5+) con escasas diferencias entre sexos y dominancia de edades intermedias (2+ y 3+). La estructura de edades mostró variaciones significativas en el gradiente con tendencia a presentar menor nú- mero de clases en localidades a menor altitud. La tasa de creci- miento se relacionó negativamente con la longevidad y mostró di- ferencias entre sectores fluviales. La tasa de crecimiento en la fase de transición a la madurez mostró tendencia a disminuir con el gra- diente, pero también conforme decrece el estado ecológico y au- menta la conductividad

    New symmetrical quinazoline derivatives selectively induce apoptosis in human cancer cells

    Get PDF
    In the search of new symmetrical derivatives with anticancer activity, we have looked for novel compounds able to induce a selective proapoptotic mechanism in cancer cells. The potential antitumoral activity of several quinazoline derivatives was evaluated in vitro examining their cytotoxic effects against human breast, colon and bladder cancer cell lines. The IC(50) value of the compounds that showed cytotoxic activity was calculated. These compounds were tested for their ability to induce caspase-3 activation and nuclear chromatin degradation. Non-tumoral human cell lines were used to test the selectivity of the cytotoxic compounds against cancer cells. Several compounds showed no cytotoxicity in these cell lines. Finally, JRF12 (2,4-dibenzylaminoquinazoline) was chosen as the best candidate and its mechanism of action was studied in more detail. A time dependent evaluation of apoptosis was performed in the three cancer cell lines, followed by an evaluation of the cell cycle regulation involvement that showed a decrease of cells in G(1) phase and increase of cells in G(2) phase before cell death. 2,4-dibenzylaminoquinazoline treatment produces few changes in the expression of genes as evaluated by using oligonucleotide microarrays and Q-RT-PCR assays. In conclusion, 2,4-dibenzylaminoquinazoline is a promising anticancer drug showing cytostatic and apoptotic effects mainly in a transcription independent manner
    corecore