Is Oreochromis niloticus invading the Samborombón Bay, Río de la Plata, Argentina?

The Nile tilapia (Oreochromis niloticus) is a species widely cultivated worldwide. In recent decades it was an increasing development of fish farming of this species and the red variety in Argentina and Uruguay. From January to March 2010, four specimens of O. niloticus were captured in the south boundary of Samborombón Bay (S 36° 17´- W 56° 46´), which is the external sector of the Río de la Plata. Probably the collected specimens were released accidentally from hatcheries placed on the banks of aquatic environments in communication with the Samborombón Bay. The patterns and mechanisms of species dispersal are of significant interest, while the interactions among factors determining invasion success often remain poorly understood. Invasion success is influenced by the ability of invading specie to withstand, interactions with native species and oceanographic characteristics of the new habitat. Of four specimens obtained two were females, one in spawning stage. This is the first record of Nile tilapia from a natural environment in Argentina and could indicate the beginning of a new invasion by a non native species.La Tilapia del Nilo (Oreochromis niloticus) es una especies cultivada en todo el mundo. En Argentina y Uruguay, la cría de tilapia ha tenido un incremento importante en las últimas décadas. Entre enero y marzo de 2010 fueron capturados cuatro ejemplares de O. niloticus en la Bahía de Samborombón (S 36º 17´- O 56º 46´), en el sector externo del Río de la Plata. Probablemente los ejemplares capturados puedan haber resultado de escapes accidentales de criaderos ubicados en ambientes en comunicación con el Río de la Plata. De los cuatro ejemplares capturados dos fueron hembras, una de ellas en etapa de desove. Este es el primer registro de Tilapia del Nilo en un ambiente natural en Argentina y podría indicar el comienzo de una invasión por una especie no nativa. Los patrones y los mecanismos de dispersión de especies son de gran interés, mientras que las interacciones entre los factores que determinan el éxito de la invasión a menudo, son poco interpretadas. El éxito de la invasión está influenciado por la capacidad de los invasores para resistir a las interacciones con especies nativas y con las características oceanográficas del nuevo hábitat, que en este caso parecerían no ser desfavorables para O. niloticus

¿Es Oreochromis niloticus un invasor en la Bahía de Samborombón, Río de la Plata (Argentina)?

The Nile tilapia (Oreochromis niloticus) is a species widely cultivated worldwide. In recent decades it was an increasing development of fish farming of this species and the red variety in Argentina and Uruguay. From January to March 2010, four specimens of O. niloticus were captured in the south boundary of Samborombón Bay (S 36° 17'- W 56° 46', which is the external sector of the Río de la Plata. Probably the collected specimens were released accidentally from hatcheries placed on the banks of aquatic environments in communication with the Samborombón Bay. The patterns and mechanisms of species dispersal are of significant interest, while the interactions among factors determining invasion success often remain poorly understood. Invasion success is influenced by the ability of invading specie to withstand, interactions with native species and oceanographic characteristics of the new habitat. Of four specimens obtained two were females, one in spawning stage. This is the first record of Nile tilapia from a natural environment in Argentina and could indicate the beginning of a new invasion by a non native species.La Tilapia del Nilo (Oreochromis niloticus) es una especies cultivada en todo el mundo. En Argentina y Uruguay, la cría de tilapia ha tenido un incremento importante en las últimas décadas. Entre enero y marzo de 2010 fueron capturados cuatro ejemplares de O. niloticus en la Bahía de Samborombón (S 36Q 17x- O 56Q 46'), en el sector externo del Río de la Plata. Probablemente los ejemplares capturados puedan haber resultado de escapes accidentales de criaderos ubicados en ambientes en comunicación con el Río de la Plata. De los cuatro ejemplares capturados dos fueron hembras, una de ellas en etapa de desove. Este es el primer registro de Tilapia del Nilo en un ambiente natural en Argentina y podría indicar el comienzo de una invasión por una especie no nativa. Los patrones y los mecanismos de dispersión de especies son de gran interés, mientras que las interacciones entre los factores que determinan el éxito de la invasión a menudo, son poco interpretadas. El éxito de la invasión está influenciado por la capacidad de los invasores para resistir a las interacciones con especies nativas y con las características oceanógraficas del nuevo hábitat, que en este caso parecerían no ser desfavorables para O. niloticus.Facultad de Ciencias Naturales y Muse

¿Es Oreochromis niloticus un invasor en la Bahía de Samborombón, Río de la Plata (Argentina)?

The Nile tilapia (Oreochromis niloticus) is a species widely cultivated worldwide. In recent decades it was an increasing development of fish farming of this species and the red variety in Argentina and Uruguay. From January to March 2010, four specimens of O. niloticus were captured in the south boundary of Samborombón Bay (S 36° 17'- W 56° 46', which is the external sector of the Río de la Plata. Probably the collected specimens were released accidentally from hatcheries placed on the banks of aquatic environments in communication with the Samborombón Bay. The patterns and mechanisms of species dispersal are of significant interest, while the interactions among factors determining invasion success often remain poorly understood. Invasion success is influenced by the ability of invading specie to withstand, interactions with native species and oceanographic characteristics of the new habitat. Of four specimens obtained two were females, one in spawning stage. This is the first record of Nile tilapia from a natural environment in Argentina and could indicate the beginning of a new invasion by a non native species.La Tilapia del Nilo (Oreochromis niloticus) es una especies cultivada en todo el mundo. En Argentina y Uruguay, la cría de tilapia ha tenido un incremento importante en las últimas décadas. Entre enero y marzo de 2010 fueron capturados cuatro ejemplares de O. niloticus en la Bahía de Samborombón (S 36Q 17x- O 56Q 46'), en el sector externo del Río de la Plata. Probablemente los ejemplares capturados puedan haber resultado de escapes accidentales de criaderos ubicados en ambientes en comunicación con el Río de la Plata. De los cuatro ejemplares capturados dos fueron hembras, una de ellas en etapa de desove. Este es el primer registro de Tilapia del Nilo en un ambiente natural en Argentina y podría indicar el comienzo de una invasión por una especie no nativa. Los patrones y los mecanismos de dispersión de especies son de gran interés, mientras que las interacciones entre los factores que determinan el éxito de la invasión a menudo, son poco interpretadas. El éxito de la invasión está influenciado por la capacidad de los invasores para resistir a las interacciones con especies nativas y con las características oceanógraficas del nuevo hábitat, que en este caso parecerían no ser desfavorables para O. niloticus.Facultad de Ciencias Naturales y Muse

High PM10 concentrations in the city of Buenos Aires and their relationship with meteorological conditions

In this work, the first long-term (eight years) record of hourly concentrations of carbon monoxide (CO), nitrogen dioxide (NO2) and particulate matter with diameter less than 10 μm (PM10) from three sites in the city of Buenos Aires is analysed. Considering the short-term guidelines suggested by the WHO, the daily mean PM10 concentrations present a relatively large number of exceedances at the three sites. Different statistical techniques are combined to study the relationship between these relatively high PM10 concentrations and relevant surface meteorological variables. For all pollutants and sites, wind speed shows the largest differences between the lowest and highest concentration quartiles. To further explore its role on daily mean PM10 concentration, a k-means algorithm is applied, grouping days with similar surface 1h-wind sequences. Five wind sequence clusters are found, presenting distinctive air quality data features. Two clusters (1 and 2) show that PM10 exceedances occurring with winds entering the city from the river represent between 10 and 21% of total events at the three sites. The frequency of exceedance under these conditions decreases with the distance to the coast. For cluster 1, the hourly PM10 concentration profile and its associated daily wind sequence suggest an important contribution to exceedance events from the city's southernmost power plant. Two clusters (3 and 4), exhibiting continental winds, account for 49–59% of the exceedances and co-occur with relatively drier air conditions. The correlation between CO and PM10 for days belonging to cluster 3 supports the hypothesis of a potential remote or distributed source contribution with SW winds. For cluster 4, differences among sites in the number of events under NNW winds suggest an important contribution from the city's widest avenue to the PM10 levels at the most coastal site. A large contribution coming from urban sources is also indicated for these winds. Finally, cluster 5, exhibiting low wind speed sequences, accounts for 23–33% of the exceedances at the three sites. The average PM10 concentration increases with persistence of this cluster, which could be a driver for exceedances. These results contribute to show the importance of simple methods such as clustering analysis to obtain insights into air quality features such as exceedances and their potential drivers. They also suggest that further efforts in monitoring, modelling and emission estimates may help to better understand local, urban and regional source contributions to these events in the city of Buenos Aires.Fil: Pineda Rojas, Andrea Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Borge, Rafael. Universidad Politécnica de Madrid; EspañaFil: Mazzeo, Nicolás A.. Universidad Tecnológica Nacional. Facultad Regional Avellaneda; ArgentinaFil: Saurral, Ramiro Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Matarazzo, Bruno Nicolas. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; ArgentinaFil: Cordero, Jose M.. Universidad Politécnica de Madrid; EspañaFil: Kropff, Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Intratumoral injection of bone-marrow derived dendritic cells engineered to produce interleukin-12 induces complete regression of established murine transplantable colon adenocarcinomas

Stimulation of the antitumor immune response by dendritic cells (DC) is critically dependent on their tightly regulated ability to produce interleukin-12 (IL-12). To enhance this effect artificially, bone marrow (BM)-derived DC were genetically engineered to produce high levels of functional IL-12 by ex vivo infection with a recombinant defective adenovirus (AdCMVIL-12). DC-expressing IL-12 injected into the malignant tissue eradicated 50-100% well established malignant nodules derived from the injection of two murine colon adenocarcinoma cell lines. Successful therapy was dependent on IL-12 transfection and was mediated only by syngeneic, but not allogeneic BM-derived DC, indicating that compatible antigen-presenting molecules were required. The antitumor effect was inhibited by in vivo depletion of CD8+ T cells and completely abrogated by simultaneous depletion with anti-CD4 and anti-CD8 mAbs. Mice which had undergone tumor regression remained immune to a rechallenge with tumor cells, showing the achievement of long-lasting systemic immunity that also was able to reject simultaneously induced concomitant untreated tumors. Tumor regression was associated with a detectable CTL response directed against tumor-specific antigens probably captured by DC artificially released inside tumor nodules. Our results open the possibility of similarly treating the corresponding human malignancies

Sox2 promotes tamoxifen resistance in breast cancer cells

Development of resistance to therapy continues to be a serious clinical problem in breast cancer management. Cancer stem/progenitor cells have been shown to play roles in resistance to chemo- and radiotherapy. Here, we examined their role in the development of resistance to the oestrogen receptor antagonist tamoxifen. Tamoxifen-resistant cells were enriched for stem/progenitors and expressed high levels of the stem cell marker Sox2. Silencing of the SOX2 gene reduced the size of the stem/progenitor cell population and restored sensitivity to tamoxifen. Conversely, ectopic expression of Sox2 reduced tamoxifen sensitivity in vitro and in vivo. Gene expression profiling revealed activation of the Wnt signalling pathway in Sox2-expressing cells, and inhibition of Wnt signalling sensitized resistant cells to tamoxifen. Examination of patient tumours indicated that Sox2 levels are higher in patients after endocrine therapy failure, and also in the primary tumours of these patients, compared to those of responders. Together, these results suggest that development of tamoxifen resistance is driven by Sox2-dependent activation of Wnt signalling in cancer stem/progenitor cells

Liver Transplantation in Patients with Hepatocellular Carcinoma Across Milan Criteria

Milan criteria are the most frequently used limits for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC), but our previous experience with expanded criteria showed encouraging results. The aim of this study was to investigate whether our expanded Clinica Universitaria de Navarra (CUN) criteria (1 nodule up to 6 cm or 2-3 nodules up to 5 cm each) could be used to select patients with HCC for LT. Eighty-five patients with HCC fulfilling CUN criteria were included as candidates for LT. Survival of transplanted HCC patients was compared with survival of patients without HCC (n = 180). After the exclusion of 2 patients with tumor seeding of the chest wall due to pre-LT tumor biopsy, survival and recurrence rates were compared according to tumor staging. Twenty-six out of 85 (30%) patients exceeded Milan criteria. Twelve patients had tumor progression on the waiting list. Patients exceeding Milan criteria had a higher dropout rate due to tumoral progression. One-, 3-, 5-, 7-, and 10-year survival rates of the 73 transplanted HCC patients were 86%, 74%, 70%, 61%, and 50%, respectively. Survival of patients with HCC was significantly lower than that of patients without HCC, but by multivariate analysis, HCC was not associated with lower survival. Tumor recurrence and survival rates were similar for patients fulfilling Milan and CUN criteria. Pathological staging showed 55 patients within Milan criteria, 7 patients exceeding them but within CUN criteria, and 9 patients exceeding CUN criteria. Tumor recurrence rates were 2/55 (4%), 0/7 (0%), and 4/9 (44%) in each of these groups, respectively. In conclusion, following CUN criteria could increase the number of HCC patients who could benefit from LT, without worsening the results. Because of the short number of patients in this series, these data need external validation

Risk factors of lung, head and neck, esophageal, and kidney and urinary tract carcinomas after liver transplantation: the effect of smoking withdrawal

Liver transplant recipients have an increased risk of malignancy. Smoking is related to some of the most frequent causes of posttransplant malignancy. The incidence and risk factors for the development of neoplasia related to smoking (head and neck, lung, esophageal, and kidney and urinary tract carcinomas) were studied in 339 liver transplant recipients. Risk factors for the development of smoking-related neoplasia were also studied in 135 patients who had a history of smoking so that it could be determined whether smoking withdrawal was associated with a lower risk of malignancy. After a mean follow-up of 7.5 years, 26 patients were diagnosed with 29 smoking-related malignancies. The 5- and 10-year actuarial rates were 5% and 13%, respectively. In multivariate analysis, smoking and older age were independently associated with a higher risk of malignancy. In the smoker subgroup, the variables related to a higher risk of malignancy were active smoking and older age. In conclusion, smoking withdrawal after liver transplantation may have a protective effect against the development of neoplasia