Cyanobacteria and microcystins in lake Furnas (S. Miguel island-Azores)

This study investigated the changes in the cyanobacterial population and quantified the occurrence of microcystins in Lake Furnas during the first decade of the 21st century. The eutrophication of Lake Furnas has been recognized since the 1980s. The lake's phytoplankton population increased over the years in relation to this process of nutrient enrichment. Cyanobacteria began to dominate the phytoplankton and blooms of greater than 20 · 103 cells/ml occurred. After 2004, cyanobacterial blooms occurred regularly in the lake throughout the year. From 2000 through 2009, 30 blooms were detected. Of these blooms, 13 were dominated by Microcystis aeruginosa and 11 by Woronichinia naegeliana. In the other 6 blooms, the dominant cyanobacteria were Microcystis spp., Anabaena spp., Aphanocapsa spp. and Coelosphaerium kuetzingianum. A number of blooms involved more than 2 species simultaneously. The highest cell density (12.3 · 106 cells/ml) occurred during winter 2007. The predominant species in this bloom were M. aeruginosa (11.9 · 106 cells/ml) and W. naegeliana (83.8 · 103 cells/ml). Because almost all of the cyanobacteria cited were considered toxin producers, a search for microcystins, the hepatotoxins most often found in freshwaters, was initiated in 2001. Samples were collected at four depths: surface, 2.5 m, 5.0 m and 0.5 m above the sediments. From 2001 through 2009, soluble microcystins were detected six times during the summer, four times during the winter and autumn and three times during the spring (25 % of 129 samples). The average concentrations of soluble microcystins in the water column ranged from 0.1 µg/l to 0.5 µg/l. Intracellular microcystins were detected in 84 % of the samples. All samples collected after 2004 contained these cyanotoxins. The average concentrations of intracellular microcystins in the water column ranged from 0.1 µg/l to 11.2 µg/l. The highest value (154.5 µg/l) was found in a water sample collected from the lake surface during the winter of 2009, during a bloom dominated by W. naegeliana. The amounts of microcystins produced by cyanobacteria, expressed on a seston dry weight basis, varied between 24 mg/kg and 9737 mg/kg and showed an increase in 2008 and 2009. The concentrations of microcystins in samples from M. aeruginosa blooms ranged from 86 mg/kg to 1171 mg/kg and the highest values were recorded during the spring and summer of 2008.Este estudio presenta la variación de la población de cianobacterias y la cuantificación de microcistinas en la Laguna Furnas en la primera década del siglo 21. La eutrofización de la Laguna Furnas había sido señalada desde los años ochenta del siglo pasado. Debido a este proceso de enriquecimiento en nutrientes, la población de fitoplancton aumentó a lo largo de los años, las cianobacterias se volvieron dominantes y surgieron blooms (más de 20 · 103 células/ml). Después del 2004, los blooms de cianobacterias fueron permanentes en la laguna. De 2000 a 2009, se detectaron 30 blooms, 13 dominados por Microcystis aeruginosa y 11 por Woronichinia naegeliana. En los 6 restantes, las cianobacterias dominantes fueron Microcystis spp., Anabaena spp., Aphanocapsa spp. y Coelosphaerium kuetzingianum. A recesen algunas ocasiones, existieron más de dos especies en la fase de Bloom al mismo tiempo. La densidad celular más alta (12.3 · 106 células/ml) tuvo lugar en el invierno de 2007, siendo M. aeruginosa (11.9 · 106 células/ml) y la W. naegeliana (83.8 · 103 células/ml) las especies predominantes. A partir de 2001 y una vez que casi todas las cianobacterias mencionadas fueron consideradas como productoras de toxinas, se inició la búsqueda de microcistinas, concretamente las hepatotoxinas ya que son las más frecuentes en aguas dulces. Las muestras se tomaron en cuatro profundidades: superficie, 2.5 m, 5.0 m y 0.5 m por cima del sedimento. De 2001 a 2009, fueron detectadas microcistinas solubles seis veces en verano, cuatro veces en invierno y otoño y tres veces en primavera (25 %de 129 muestras). Sus concentraciones medias en la columna de agua variaron desde 0.1 µg/l hasta 0.5 µg/l. Fueron detectadas microcistinas intracelulares en el 84 % de las muestras y en todas las recogidas después del 2004. Sus concentraciones medias en la columna de agua variaron desde 0.1 µg/l hasta 11.2 µg/l. El valor más alto (154.5 µg/l) fue encontrado en una muestra recogida en la superficie durante el invierno de 2009, mientras ocurría un bloom dominado por W. naegeliana. Las cantidades de microcistinas producidas por las cianobacterias, expresadas en base de peso seco del seston, variaron entre 24 mg/kg y 9737 mg/kg y mostraron un aumento en los años 2008 y 2009. Las concentraciones en muestras de blooms de M. aeruginosa variaron desde 86 mg/kg hasta 1171 mg/kg y los valores más altos fueron registrados en primavera y verano de 2008

Monitorização in continuum da Lagoa das Sete Cidades

Nas últimas décadas, a Lagoa das Sete Cidades (Ilha de São Miguel, Açores) tem sido afectada por um lento processo de eutrofização que, recentemente, conduziu a um agravamento da sua qualidade química e ecológica. Para avaliar o estado actual da Lagoa e monitorizar a sua evolução foi implementado um sistema de monitorização in continuum, baseado numa estação remota multiparamétrica e em análises periódicas do fitoplâncton. A monitorização in continuum permitiu caracterizar a evolução sazonal dos parâmetros físico-químicos, verificando-se uma rápida transição entre os períodos de mistura e estratificação da massa de água. O desenvolvimento da estratificação térmica foi determinante na evolução da comunidade fitoplanctónica

Biomanipulação nas lagoas das Sete Cidades e das Furnas (São Miguel, Açores)

XII congresso da Associação Espanhola de Limnologia/IV Congresso Ibérico de Limnologia, organizado pela Associação Espanhola de Limnologia, de 5 a 9 de Julho de 2004 no Porto, Portugal.A qualidade da água de um sistema lacustre de baixa profundidade não deve ser avaliada apenas segundo a concentração de nutrientes, uma vez que esses sistemas podem existir em dois estados alternativos: um de água transparente, dominado por macrófitos, e outro de água turva dominado por fitoplâncton

Lagoas de São Miguel (Açores): caracterização, problemas e soluções

XII congresso da Associação Espanhola de Limnologia/IV Congresso Ibérico de Limnologia, organizado pela Associação Espanhola de Limnologia, de 5 a 9 de Julho de 2004 no Porto, Portugal.A ilha de São Miguel é a maior ilha do arquipélago dos Açores, com aproximadamente 747 km2 de superfície. Nesta ilha existem mais de 30 lagoas e lagoeiros (Constância et al., 1997). Os maiores ecossistemas lacustres da ilha são as lagoas do Fogo, das Sete Cidades e das Furnas. Nestas duas últimas lagoas existe um problema de eutrofização das massas de água resultante das actividades antropogénicas desenvolvidas nas bacias hidrográficas, em especial as explorações agro-pecuárias, o qual constitui um dos problemas mais graves de degradação da qualidade bio-físico-química da água. Uma das consequências do aumento de nutrientes é a proliferação da biomassa de fitoplâncton

Ecological quality of Azorean coastal waters.

International Conference on Coastal Conservation and Management in the Atlantic and Mediterranean. Estoril, Portugal, 12-17 de Abril de 2010

Micronucleus frequency and exposure to chemical mixtures in three Colombian mining populations

La industria minera colombiana ha experimentado un crecimiento significativo. Dependiendo de la escala y del mineral extraído, se generan mezclas químicas complejas que impactan la salud de las poblaciones ocupacionalmente expuestas y de las comunidades cercanas a los proyectos mineros. Cada vez hay más evidencias que sugieren que la inestabilidad cromosómica (CIN) es un vínculo importante entre el desarrollo de ciertas enfermedades y la exposición a mezclas complejas. Para comprender mejor los efectos de la exposición a mezclas complejas realizamos un estudio de biomonitorización en 407 individuos sanos de cuatro zonas: tres situadas en municipios que explotan sistemas mineros de diferente escala y una zona de referencia sin actividad minera. Se analizaron sistemas de minería a gran, mediana y pequeña escala en Montelíbano (Córdoba), minería artesanal y de pequeña escala (MAPE) en Nechí (Antioquia) y un sistema de minería cerrada en Aranzazu (Caldas). El área de referencia sin actividad minera se estableció en Montería (Córdoba). La ICP-MS midió la exposición multielemental en el cabello, y la NIC se evaluó mediante la técnica de micronúcleos en bloque de citocinesis (MNBN). La exposición a mezclas de elementos químicos fue comparable en trabajadores y residentes de las zonas mineras, pero significativamente superior en comparación con los individuos de referencia. En Montelíbano, el aumento de las frecuencias de MNBN se asoció con la exposición combinada a Se, Hg, Mn, Pb y Mg. Este patrón distintivo difirió significativamente de otras áreas. Específicamente, en Nechí, Cr, Ni, Hg, Se, y Mg emergieron como los principales contribuyentes a las frecuencias elevadas de MNBN. Por el contrario, una combinación de Hg y Ni desempeñó un papel en el aumento de MNBN en Aranzazu. Curiosamente, el Se se correlacionó consistentemente con el aumento de las frecuencias de MNBN en todas las áreas mineras activas. Los elementos químicos en Montelíbano muestran un rango más amplio en comparación con otras zonas mineras, reflejando las características de la minería de alto impacto y a gran escala en la zona. Esta investigación proporciona información valiosa sobre los efectos de la exposición a mezclas químicas, subrayando la importancia de emplear este enfoque en la evaluación del riesgo de las comunidades, especialmente las de las zonas residenciales. © 2023 Los autoresThe Colombian mining industry has witnessed significant growth. Depending on the scale and mineral extracted, complex chemical mixtures are generated, impacting the health of occupationally exposed populations and communities near mining projects. Increasing evidence suggests that chromosomal instability (CIN) is an important link between the development of certain diseases and exposure to complex mixtures. To better understand the effects of exposure to complex mixtures we performed a biomonitoring study on 407 healthy individuals from four areas: three located in municipalities exploiting different-scale mining systems and a reference area with no mining activity. Large, medium, and small-scale mining systems were analyzed in Montelibano (Córdoba), artisanal and small-scale mining (ASGM) in Nechí (Antioquia), and a closed mining system in Aranzazu (Caldas). The reference area with no mining activity was established in Montería (Córdoba). ICP-MS measured multi-elemental exposure in hair, and CIN was evaluated using the cytokinesis-block micronucleus technique (MNBN). Exposure to mixtures of chemical elements was comparable in workers and residents of the mining areas but significantly higher compared to reference individuals. In Montelibano, increased MNBN frequencies were associated with combined exposure to Se, Hg, Mn, Pb, and Mg. This distinct pattern significantly differed from other areas. Specifically, in Nechí, Cr, Ni, Hg, Se, and Mg emerged as the primary contributors to elevated frequencies of MNBN. In contrast, a combination of Hg and Ni played a role in increasing MNBN in Aranzazu. Interestingly, Se consistently correlated with increased MNBN frequencies across all active mining areas. Chemical elements in Montelibano exhibit a broader range compared to other mining zones, reflecting the characteristics of the high-impact and large-scale mining in the area. This research provides valuable insights into the effects of exposure to chemical mixtures, underscoring the importance of employing this approach in the risk assessment of communities, especially those from residential areas. © 2023 The Author

Meta-analysis of type 2 Diabetes in African Americans Consortium

Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR)  = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe

Global Retinoblastoma Presentation and Analysis by National Income Level.

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly