RESUMO
Individuals of Mytilus platensis were exposed to Alexandrium catenella to evaluate the accumulation and metabolization of paralytic shellfish toxins (PST) over a period of 25 days. Mussels were collected from the intertidal zone of Cerro Avanzado, Argentine Patagonia. After 16 days, the toxins in the tissues of mussels were detected by the methods of mouse bioassay and high performance liquid chromatography with fluorometric detection (HPLC-FDL). The accumulation kinetics of PST toxins in M. platensis fed with A. catenella fitted to a linear function, in which the accumulation rate was 31.2 µg STX eq kg-1 day-1. After 16 days, the PST toxin level in tissues of mussels reached 1178 µg STX eq kg-1 exceeding the safety limit for human consumption (800 µg STX eq kg-1 tissue), whereas the highest PST toxin level was reached at the end of the experimentation (1613 µg STX eq kg-1) at 25 days. Differences in the toxin profile of the dinoflagellates and the tissues of the mussels confirmed biotransformation of PST in the mussel digestive system. The toxin profile of M. platensis was dominated by the gonyautoxins GTX1 and GTX4, while the toxin profile of A. catenella was dominated by the N-sulfocarbamoyl toxin C2. To our knowledge, this is the first experimentation on a laboratory scale of PST toxins accumulation in M. platensis with a native strain of A. catenella of Argentine Patagonia.
Assuntos
Dinoflagellida/fisiologia , Toxinas Marinhas , Mytilus/fisiologia , Animais , Argentina , Bioensaio , Saxitoxina/análogos & derivados , Alimentos MarinhosRESUMO
The health status of the commercial Tehuelche scallop Aequipecten tehuelchus from San Román and El Riacho in San José gulf (Patagonia, Argentina) was evaluated through biomarkers widely used in ecotoxicological applications. Natural levels of arsenic (As) and cadmium (Cd) were measured to determine their potential relationships with fluctuations of several oxidative stress biomarkers in the scallop. Oxidative biomarkers, such as catalase (CAT), glutathione S-transferase (GST), superoxide dismutase (SOD), metallothioneins (MT), reactive oxygen species (ROS), α-tocopherol (α-T), and lipid peroxidation (LPO) through thiobarbituric acid reactive substances (TBARS) and lipid radical (LRâ), were measured in gills, digestive gland, and muscle of Tehuelche scallop in winter (August 2015) and summer (January 2016). Levels of As and Cd and of most of the biomarkers (SOD, ROS, TBARS, and LRâ) showed strong seasonal variability in the three tissues. In general, the highest values were recorded in digestive gland. The Integrated Biomarker Response index indicated that the most stressed condition of A. tehuelchus was in summer in San Román. Additionally, the Integrated Biomarker Response index showed a strong relationship among tissues and As and Cd accumulation. This kind of approach could be used as an integrated tool to identify the health status of scallop A. tehuelchus from San José gulf.
Assuntos
Bioacumulação/efeitos dos fármacos , Monitoramento Ambiental/métodos , Estresse Oxidativo/efeitos dos fármacos , Pectinidae/efeitos dos fármacos , Poluentes Químicos da Água/análise , Animais , Argentina , Biomarcadores/metabolismo , Brânquias/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Músculos/metabolismo , Pectinidae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Alimentos Marinhos/análise , Estações do Ano , Poluentes Químicos da Água/metabolismoRESUMO
The BCR method was applied on sediments from the salt marsh of San Antonio Bay (SAB). It presents several channels among which the Encerrado is the most important and is impacted by abandoned mining wastes. The pseudototal concentrations of metals measured within this channel were relatively higher than in outer sites, and according to the Igeo index, its contamination level was low. The metal distribution in the different phases of sediment particles showed that the residual component, considered the safest from the environmental point of view, accounted for most of the Fe, Cd, Cu, and Zn contents. Conversely, Pb was mainly in the non-residual component as part of the reducible fraction, thus constituting the main environmental hazard among the studied elements. The predominance of residual and reducible fractions indicated a historic contamination of metal such as Pb, Cu, and Zn from the mining wastes. The low exchangeable and oxidizable fractions would indicate no actual input of metals.
Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes Químicos da Água/análise , Áreas Alagadas , Baías , Sedimentos Geológicos , Mineração , TexasRESUMO
The Natural Protected Area San Antonio bay is of particular importance for its congregation of migratory shorebirds and it has been declared one of the Western Hemisphere Shorebird Reserve Network International site (WHSRN). Present study represents the first assessment of variation on oxidative stress biomarkers in male crab Neohelice granulata from San Antonio bay (Río Negro, Argentina) under field conditions, associated mainly to metal contamination coming from passive mining wastes. Three sites were sampled once every three months from November 2012 to August 2013 within this sea inlet (Pile, Fishery and Port) and a control site at the southeast of the bay (Punta Perdices). Accumulation of Ni, Zn, Cr and Al varied only with seasons although without a constant trend, meanwhile Cd, Cu and Pb also varied among sites being highest in Pile and Port. Biochemical results indicated that variations in catalase activity was only site specific being maximum in Pile; meanwhile lipid radical, α-tocopherol and metallothioneins were only seasonal specific being higher in autumn and winter. Seasonal variation was also found for total thioles, being the content higher in summer and autumn than in winter. Correlation analysis revealed that malondialdehyde and α-tocopherol have a positive association with Al and negative with Ni, meanwhile GST has a positive association with Fe. Crabs from the closest area to the waste pile did not exhibit a differentiated oxidative pressure despite the higher accumulation of metals. It is possible that crabs from contaminated areas have developed a tolerance to metals, indicating a strong ecotoxicological selective pressure. More studies are needed to assess whether there is a transfer of metals through the food chain.
Assuntos
Braquiúros/efeitos dos fármacos , Metais/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Argentina , Baías , Braquiúros/metabolismo , Monitoramento Ambiental/métodos , Resíduos Industriais , Masculino , Metais/análise , Mineração , Estresse Oxidativo/efeitos dos fármacos , Estações do Ano , Poluentes Químicos da Água/análiseRESUMO
In this study, we assessed in gills of native ribbed mussels Aulacomya atra atra from three sites within Nuevo Gulf (Northern Patagonia) several biomarkers such as reactive oxygen species (ROS), lipid radicals (LR), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and metallothionein (MT). Furthermore, concentrations of main trace metals (Fe, Al, Zn, Cu, Cd and Pb) were quantified in mussel tissue. Results showed significant induction of SOD, GST, MT and MDA, as well as, higher concentration of Fe, Al and Cd in winter than in summer. The high MDA content measured in mussels from Folías Wreck seemed to be caused by the very high levels of Fe that would come from the corrosion of the vessel. Mussels from the control site Punta Cuevas presented the lowest levels of Cd and the highest of Al in winter. Despite positive correlations were found between Al and GST and MT, no spatial differentiation was detected in those biomarkers. On the other hand, MT was only related to Al been most likely influenced by environmental variables than by the trace metals. It has to be highlighted that the relationship detected among water temperature, nutrients and antioxidant responses in gills is probably related to the fact that this tissue is in direct contact with water and it is sensitive to its fluctuations. Taking into account that mussel gill is a tissue actively proliferating and the first target of contaminants present in water, so that changes in its antioxidant system can provide an earlier warning signal than in other tissues.
Assuntos
Biomarcadores/análise , Monitoramento Ambiental , Brânquias/química , Mytilidae/química , Estresse Fisiológico , Animais , Antioxidantes/análise , Argentina , Catalase/análise , Feminino , Brânquias/enzimologia , Glutationa Transferase/análise , Masculino , Malondialdeído/análise , Metalotioneína/análise , Mytilidae/enzimologia , Espécies Reativas de Oxigênio/análise , Estações do Ano , Superóxido Dismutase/análise , Oligoelementos/análiseRESUMO
This study investigates the effects of different inorganic arsenic (As III) concentrations (0, 125, 500 and 1000 µg As/L) following two exposure times (7 and 14 days) on gills, digestive gland and muscle of scallop Aequipecten tehuelchus from Patagonia, Argentina. A biochemical approach was used to investigate oxidative stress-related parameters after different As concentrations and exposure times. Although the accumulation of As was of the same order of magnitude in all tissues, the results showed distinct tissue-specific oxidative responses to this metalloid. Furthermore, the variation in exposure time had no significant effect on As accumulation in any of the three tissues. In gills, despite no reactive oxygen and nitrogen species (RONS) were detected, there was an increase in catalase (CAT) activity and metallothionein (MT) levels. Conversely, digestive gland showed RONS production without a rise in CAT and glutathione S-transferases (GST) activities, but with an increase in MT levels. In muscle, RONS production and CAT activity kept constant or decreased, while MT levels remained unchanged. In addition, exposure time demonstrated its critical role in gills by influencing the response of CAT, GST and MT, particularly at high As concentrations, while exposure time did not affect the biochemical stress parameters in the digestive gland and muscle. Interestingly, neither concentration of As produced lipid damage, showing the effectiveness of the antioxidant mechanisms to avoid it. These results emphasize that A. tehuelchus exhibited no time-dependent effects in response to As exposure, while showing tissue-specific responses characterized by significant concentration-dependent effects of As. This study provides a comprehensive insight by considering the combined effects of time and concentration of a contaminant and distinguishing its effects on specific tissues, a dimension often overlooked in the existing literature. Subsequent studies should prioritize the analysis of additional contaminants in species with increased sensitivity.
Assuntos
Arsênio , Pectinidae , Poluentes Químicos da Água , Animais , Arsênio/análise , Argentina , Poluentes Químicos da Água/análise , Pectinidae/metabolismo , Estresse Oxidativo , Antioxidantes/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Brânquias/metabolismo , Catalase/metabolismo , Peroxidação de LipídeosRESUMO
This study aimed to assess the impact of acute exposure (96 h) to Cd in gills, digestive gland and muscle of the Tehuelche scallop Aequipecten tehuelchus from San José gulf in Patagonia, Argentina. Scallops were exposed to Cd concentrations of 0, 25, 50, 100, 150, 204, 275, 371, and 500 µg/L, and mortality rates were recorded after 96 h of exposure. Surviving organisms were analyzed for the biochemical response through reactive oxygen and nitrogen species (RONS), activities of catalase (CAT) and glutathione-S-transferase (GST), metallothioneins (MT), lipid peroxidation (LPO) and liposoluble antioxidants α-tocopherol (α-T) and ß-carotene (ß-C). The mean lethal concentration (LC50) was 155.8 µg Cd/L, a lower value than other scallops' species, showing that A. tehuelchus has a particular sensitivity to Cd. In the three tissues, at all exposure concentrations, there was no significant response in RONS levels, GST activity or LPO. Nevertheless, CAT activity and α-T levels decreased in the gills but increased in the digestive gland, with no significant response in the muscle. Two-way ANOVA revealed a significant interaction between Cd concentration and tissue on MT, which increased significantly in gills, decreased in digestive gland with 100 compared to 50 µg Cd/L; whereas in muscle a significant increase was observed with 25 µg Cd/L compared to control. The results show a significant effect of Cd in scallop's gills on CAT activity and α-T levels, highlighting this tissue as the primary target against relevant concentrations of metal in seawater. The effect on digestive gland and muscle was minimal. The overall results suggest that Cd toxicity is tissue-specific. This study will help reduce the existence knowledge gap regarding potential impacts of acute exposure to Cd in a bivalve species with high ecological and commercial importance, as well as identifying the most responsive biomarkers associated with Cd stress for monitoring assessment.
Assuntos
Pectinidae , Poluentes Químicos da Água , Animais , Antioxidantes/metabolismo , Cádmio/análise , Estresse Oxidativo , Catalase/metabolismo , Pectinidae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Brânquias/metabolismo , Poluentes Químicos da Água/análise , Peroxidação de Lipídeos , Biomarcadores/metabolismoRESUMO
OBJECTIVE: To compare the pelvic lymph node involvement and risk of recurrence in patients with human papillomavirus (HPV)-associated endocervical adenocarcinoma stage IA2-IB1 undergoing hysterectomy and/or trachelectomy plus lymphadenectomy, according to Silva's classification system. METHODS: A retrospective cohort study was performed in two Colombian cancer centers. The cases were classified according to the Silva classification system. Clinical, surgical, and histopathological variables were evaluated. Recurrence risk was analyzed by patterns A, B, or C. A logistic regression model was performed for tumor recurrence. The Kaplan-Meier method was used to estimate overall survival and disease-free survival (DFS). A weighted kappa was performed to determine the degree of concordance between pathologists. RESULTS: A total of 100 patients were identified, 33% pattern A, 29% pattern B, and 38% pattern C. The median follow-up time was 42.5 months. No evidence of lymph node involvement was found in patients classified as A and B, while in the C pattern was observed in 15.8% (n = 6) of cases (P < 0.01). There were 7% of cases with recurrent disease, of which 71.5% corresponded to type C pattern. Patients with Silva pattern B and C had 1.22- and 4.46-fold increased risk of relapse, respectively, compared with pattern A. The 5-year DFS values by group were 100%, 96.1%, and 80.3% for patterns A, B, and C, respectively. CONCLUSION: For patients with early-stage HPV-associated endocervical adenocarcinoma, the type C pattern presented more lymph node involvement and risk of recurrence compared to the A and B patterns. The concordance in diagnosis of different Silva's patterns by independents pathologists were good.
Assuntos
Adenocarcinoma , Excisão de Linfonodo , Metástase Linfática , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/cirurgia , Estudos Retrospectivos , Colômbia/epidemiologia , Recidiva Local de Neoplasia/epidemiologia , Adenocarcinoma/patologia , Adenocarcinoma/virologia , Pessoa de Meia-Idade , Adulto , Infecções por Papillomavirus/complicações , Histerectomia , Linfonodos/patologia , Linfonodos/virologia , Idoso , Pelve , Intervalo Livre de Doença , TraquelectomiaRESUMO
In recent decades, worldwide cetacean species have been protected, but they are still threatened. The bottlenose dolphin (Tursiops truncatus) is a vulnerable keystone species and a useful bioindicator of the health and balance of marine ecosystems in oceans all over the world. The genetic structure of the species is shaped by their niche specialization (along with other factors), leading to the classification of two ecotypes: coastal and pelagic. In this study, the genetic diversity, population structure, and ecotypes of bottlenose dolphins from the Canary Islands were assessed through the analysis of 49 new samples from biopsies and from stranded animals using the 636 bp portion of the mitochondrial control region and 343 individuals from databases (n = 392). The results reveal high genetic diversity in Canarian bottlenose dolphins (Hd = 0.969 and π = 0.0165) and the apparent lack of population genetic structure within this archipelago. High genetic structure (Fst, Φst) was found between the Canary Islands and coastal populations, while little to no structure was found with the pelagic populations. These results suggest that Canarian bottlenose dolphins are part of pelagic ecotype populations in the North Atlantic. The studied Special Areas of Conservation in the Canary Islands may correspond to a hotspot of genetic diversity of the species and could be a strategic area for the conservation of the oceanic ecotype of bottlenose dolphins.
RESUMO
Seasonal and spatial variability of trace metal concentrations and of a battery of antioxidant parameters were evaluated in digestive gland of the ribbed mussel Aulacomya atra atra. Fe, Al and Cu accumulated in tissue exhibited maximum values in winter, coinciding partially with the highest labile concentrations of Fe and Cu in sediment. Metals, as other pollutants, are known to influence the oxidative status of organisms and antioxidant enzymes have been often proposed as biomarkers of contaminant effects. Seasonal variations of trace metals did not appear to influence those of biochemical parameters, which generally showed an opposite trend with higher enzymatic activities in summer when trace metal concentrations were lower. Organisms from Punta Cuevas (control site) showed higher induction of reactive oxygen species production than those from both considered impacted sites, suggesting the possibility of some biochemical adaptation in organisms or a higher modulation of environmental and physiological factors on antioxidant responses than levels of trace metals. This study, which is the first in the area in this matter, showed that seasonal variations of potential biomarkers should be incorporated into interpretation of long-term biomonitoring studies in this marine coastal ecosystem.
Assuntos
Bivalves/química , Metais/análise , Poluentes Químicos da Água/análise , Animais , Argentina , Bivalves/metabolismo , Monitoramento Ambiental , Metais/metabolismo , Estações do Ano , Poluentes Químicos da Água/metabolismoRESUMO
PURPOSE: To determine whether the use of Magnetic Activated Cell Sorting (MACS) as a sperm selection technique improves ART success rates in couples undergoing assisted reproduction treatment. METHODS: Systematic review and meta-analysis of prospective randomized trials. Two reviewers conducted study selection and data extraction independently. RESULTS: Five studies (prospective randomized trials) that comprised 499 patients were included. Sperm selection using MACS resulted in statistically significant differences in pregnancy rates when compared with density gradient centrifugation and swim-up techniques (RR=1.50, 95 % CI 1.14-1.98). No differences were found between the groups according to the implantation (RR=1.03, 95 % CI 0.80-1.31) and miscarriage (RR=2.00, 95 % CI 0.19-20.90) rates. CONCLUSIONS: MACS appears to be a safe and efficient method to select functional sperm with consistently good results. This technique may improve pregnancy rates when used to complement standard sperm selection methods in ART.
Assuntos
Espermatozoides/citologia , Separação Celular/métodos , Fragmentação do DNA , Implantação do Embrião , Feminino , Humanos , Magnetismo , Masculino , Gravidez , Taxa de Gravidez , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Técnicas de Reprodução AssistidaRESUMO
Geographic variation in the acoustic features of whistles emitted by the striped dolphin (Stenella coeruleoalba) from the Atlantic Ocean (Azores and Canary Islands) and the Mediterranean was investigated. Ten parameters (signal duration, beginning, end, minimum and maximum frequency, the number of inflection points, of steps, of minima and maxima in the contour and the frequency range) were extracted from each whistle. Discriminant function analysis correctly classified 73% of sounds between Atlantic Ocean and Mediterranean Sea. A cline in parameters was apparent from the Azores to the Mediterranean, with a major difference between the Canaries and the Mediterranean than between Azores and Canaries. Signal duration, maximum frequency, and frequency range measured in the Mediterranean sample were significantly lower compared to those measured in the Atlantic. Modulation parameters played a considerable role in area discrimination and were the only parameters contributing to highlight the differences within the Atlantic Ocean. Results suggest that the acoustic features constrained by structural phenotype, such as whistle's frequency parameters, have a major effect on the Atlantic and Mediterranean separation while behavioral context, social, and physical environment may be among the main factors contributing to local distinctiveness of Atlantic areas. These results have potential passive acoustic monitoring applications.
Assuntos
Acústica , Canto , Stenella/fisiologia , Acústica/instrumentação , Animais , Oceano Atlântico , Análise Discriminante , Mar Mediterrâneo , Processamento de Sinais Assistido por Computador , Espectrografia do Som , Fatores de Tempo , TransdutoresRESUMO
Background: The Canary Islands are an archipelago of volcanic origin, located off north-west Africa comprising eight islands. Fuerteventura and Lanzarote are the oldest (20 and 15 millon years old, respectively) and the easternmost islands. The order Diptera is one of the most relevant taxa in the Canary Islands as they constitute the second highest species richness. Within this order, the family Tachinidae is especially interesting as all species are endoparasitoids of arthropods and most species play a key role as pollinators. In the Canary Islands, the family comprises 52 species, with Fuerteventura and Lanzarote harbouring up to 20 species each. New information: Aphrialatifrons, a Palaearctic tachinid fly, is reported for the first time from the Canary Islands, where it was found on Fuerteventura and Lanzarote. Morphological examination was carried out and the first known barcode of the species is presented. Its potential distribution and source of origin are discussed.
RESUMO
Population genetic structure of North Atlantic killer whale samples was resolved from differences in allele frequencies of 17 microsatellite loci, mtDNA control region haplotype frequencies and for a subset of samples, using complete mitogenome sequences. Three significantly differentiated populations were identified. Differentiation based on microsatellite allele frequencies was greater between the two allopatric populations than between the two pairs of partially sympatric populations. Spatial clustering of individuals within each of these populations overlaps with the distribution of particular prey resources: herring, mackerel and tuna, which each population has been seen predating. Phylogenetic analyses using complete mitogenomes suggested two populations could have resulted from single founding events and subsequent matrilineal expansion. The third population, which was sampled at lower latitudes and lower density, consisted of maternal lineages from three highly divergent clades. Pairwise population differentiation was greater for estimates based on mtDNA control region haplotype frequencies than for estimates based on microsatellite allele frequencies, and there were no mitogenome haplotypes shared among populations. This suggests low or no female migration and that gene flow was primarily male mediated when populations spatially and temporally overlap. These results demonstrate that genetic differentiation can arise through resource specialization in the absence of physical barriers to gene flow.
Assuntos
DNA Mitocondrial/genética , Frequência do Gene/genética , Especiação Genética , Variação Genética , Orca/genética , Animais , Análise por Conglomerados , Demografia , Feminino , Peixes/genética , Genótipo , Haplótipos , Masculino , Repetições de Microssatélites/genética , Filogenia , Análise de Sequência de DNA , Fatores de TempoRESUMO
Blooms of the dinoflagellate Alexandrium catenella, which produces Paralytic Shellfish Toxins (PST), generate serious socio-economic consequences for mariculture in Chile, especially for the production of Mytilus chilensis and other bivalves. Palliative strategies, such as the depuration of mussels in enriched water with chitosan offer encouraging prospects against the advance of contaminated areas and toxin persistence. Adult mussels were fed with A. catenella for 20 days and then were allowed to depurate using chitosan as facilitator, for the same period. Intoxicated mussels showed a reduction in feeding activity and rapid PST accumulation in 20 days (C = 451.5t + 1,673.6, R2 = 0.55 p = 0.008). Not enough evidence was found to indicate a positive effect of chitosan in mussel depuration after 20 days (C = -311.1t + 8,462.4, R2 = 0.8 p = 0.001). At the end of the study, toxicity was higher than 800 µg STX eq kg-1. C2 and GTX4 analogues were the most abundant in the dinoflagellate strain, while C2 and C1 were the most accumulated in mussels. The presence of C1 was notorious during depuration, as the persistence of GTX2,3. GTX5 was only detected in A. catenella, while STX was only present in mussels. Mussel sensitivity to the presence of the toxic dinoflagellate was observed in the present study. The biotransformation, selective elimination and epimerization processes were deduced from intoxication and depuration experiments.
Assuntos
Quitosana , Dinoflagellida , Toxinas Marinhas/toxicidade , Mytilus , Animais , Chile , Quitosana/toxicidade , Frutos do Mar/análise , Intoxicação por Frutos do MarRESUMO
BACKGROUND: Prioritizing groupings of organisms or 'units' below the species level is a critical issue for conservation purposes. Several techniques encompassing different time-frames, from genetics to ecological markers, have been considered to evaluate existing biological diversity at a sufficient temporal resolution to define conservation units. Given that acoustic signals are expressions of phenotypic diversity, their analysis may provide crucial information on current differentiation patterns within species. Here, we tested whether differences previously delineated within dolphin species based on i) geographic isolation, ii) genetics regardless isolation, and iii) habitat, regardless isolation and genetics, can be detected through acoustic monitoring. Recordings collected from 104 acoustic encounters of Stenella coeruleoalba, Delphinus delphis and Tursiops truncatus in the Azores, Canary Islands, the Alboran Sea and the Western Mediterranean basin between 1996 and 2012 were analyzed. The acoustic structure of communication signals was evaluated by analyzing parameters of whistles in relation to the known genetic and habitat-driven population structure. RESULTS: Recordings from the Atlantic and Mediterranean were accurately assigned to their respective basins of origin through Discriminant Function Analysis, with a minimum 83.8% and a maximum 93.8% classification rate. A parallel pattern between divergence in acoustic features and in the genetic and ecological traits within the basins was highlighted through Random Forest analysis. Although it is not yet possible to establish a causal link between each driver and acoustic differences between basins, we showed that signal variation reflects fine-scale diversity and may be used as a proxy for recognizing discrete units. CONCLUSION: We recommend that acoustic analysis be included in assessments of delphinid population structure, together with genetics and ecological tracer analysis. This cost-efficient non-invasive method can be applied to uncover distinctiveness and local adaptation in other wide-ranging marine species.
RESUMO
The aim of this work was to characterize the microbial nitrogen cycling potential in sediments from Ushuaia Bay, a subantarctic environment that has suffered a recent explosive demographic growth. Subtidal sediment samples were retrieved in triplicate from two urban points in the Bay, and analyzed through metagenomic shotgun sequencing. Sequences assigned to genes related to nitrification, nitrate reduction and denitrification were predominant in this environment with respect to metagenomes from other environments, including other marine sediments. The nosZ gene, responsible for nitrous oxide transformation into di-nitrogen, presented a high diversity. The majority of NosZ sequences were classified as Clade II (atypical) variants affiliated to different bacterial lineages such as Bacteroidetes, Chloroflexi, Firmicutes, Proteobacteria, Verrucomicrobia, as well as to Archaea. The analysis of a fosmid metagenomic library from the same site showed that the genomic context of atypical variants was variable, and was accompanied by distinct regulatory elements, suggesting the evolution of differential ecophysiological roles. This work increases our understanding of the microbial ecology of nitrogen transformations in cold coastal environments and provides evidence of an enhanced denitrification potential in impacted sediment microbial communities. In addition, it highlights the role of yet overlooked populations in the mitigation of environmentally harmful forms of nitrogen.
Assuntos
Archaea/genética , Bactérias/genética , Desnitrificação/genética , Variação Genética , Sedimentos Geológicos/microbiologia , Metagenômica , Archaea/isolamento & purificação , Proteínas Arqueais/classificação , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Argentina , Bactérias/isolamento & purificação , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Baías , Análise por Conglomerados , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Óxido Nitroso/metabolismo , Filogenia , Análise de Sequência de DNARESUMO
The True's beaked whale (Mesoplodon mirus, True 1913) is a poorly known member of the Ziphiidae family. Its distribution in the northern hemisphere is thought to be restricted to the temperate or warm temperate waters of the North Atlantic, while a few stranding records from the southern hemisphere suggest a wider and antitropical distribution, extending to waters from the Atlantic coast of Brazil to South Africa, Mozambique, Australia and the Tasman Sea coast of New Zealand. This paper (i) reports the first molecular confirmation of the occurrence of the True's beaked whale at the southern limit of its distribution recorded in the northeast Atlantic: the Azores and Canary Islands (macaronesian ecoregion); (ii) describes a new colouration for this species using evidence from a whale with molecular species confirmation; and (iii) contributes to the sparse worldwide database of live sightings, including the first underwater video recording of this species and close images of a calf. Species identification was confirmed in two cases using mitochondrial DNA control region and cytochrome b gene markers: a subadult male True's beaked whale that stranded in El Hierro, Canary Islands, in November 2012, and a subadult male found floating dead near Faial, the Azores, in July 2004. The whale that stranded in the Canary Islands had a clearly delimited white area on its head, extending posteriorly from the tip of the beak to cover the blowhole dorsally and the gular grooves ventrally. This colouration contrasts with previous descriptions for the species and it may be rare, but it exemplifies the variability of the colouration of True's beaked whales in the North Atlantic, further confirmed here by live sightings data. The recording of several observations of this species in deep but relatively coastal waters off the Azores and the Canary Islands suggests that these archipelagos may be unique locations to study the behaviour of the enigmatic True's beaked whale.
RESUMO
INTRODUCTION: Breast Phyllodes tumors are rare breast tumors present in less than 1% of new cases of breast cancer, usually occurring among middle-aged women (40-50 yrs). OBJECTIVE: This study shows diagnostic experience, surgical management and follows up of patients with this disease during a period of ten years in a oncology referral center. METHODS: Retrospectively, breast cancer registries at the institution were reviewed, identifying 77 patients with Phyllodes tumors between 2002 and 2012, who had been operated on at the Instituto de Cancerología - Clínica Las Américas, in Medellín (Colombia). Clinical and histopathological data belonging to these cases was captured and analyzed and descriptive statistics were used. RESULTS: The follow up median was 22.5 months (IQR: 10.5-60.0), average age was 47.2 yrs (SD: 12.4), mean tumor size was 3.6 cm (SD: 4.6), 88.3% of the patients (68 cases) presented negative margins and none of them received adjuvant chemotherapy. Of the patients with Phyllodes tumors; 33.8% had benign, 31.2% had borderline and 35.0% had malignant tumor. Disease-free survival was 85.8% and overall survival was 94.5%. DISCUSSION: Reported data in this article is in accordance with what has been reported in worldwide literature. In our cohort even the high mean size of the tumors, the risk of local relapse and metastatic disease is low than previously reported in literature. Trials with longer follow up and molecular trials in Phyllodes tumors are necessary to understand the behavior of these tumors in Hispanics population.
INTRODUCCIÓN: Los tumores phyllodes mamarios son Tumores infrecuentes en la mama presentes en menos del 1% de los casos nuevos de cáncer mamario, por lo general ocurre en mujeres de mediana edad (40-50 años). OBJETIVO: Este estudio muestra la experiencia de diagnóstico, tratamiento quirúrgico y seguimiento de los pacientes con esta variedad de tumor durante un período de diez años en un centro de referencia oncológico. MÉTODOS: Retrospectivamente, los registros de cáncer de mama en la institución fueron revisados, se identificaron 77 pacientes con tumores phyllodes entre 2002 y 2012, que habían sido operados en el Instituto de Cancerología - Clínica Las Américas, en Medellín (Colombia). Los datos clínicos e histopatológicos pertenecientes a estos casos fueron recolectados y analizados utilizando técnicas de estadística descriptivas. RESULTADOS: La mediana de seguimiento fue de 22.5 meses (RIC: 10.5-60.0), la Media de edad fue de 47.2 años (DE: 12.4), tamaño medio del tumor fue de 3.6 cm (DE: 4.6), 88.3% de los pacientes (68 casos) presentaron márgenes negativos y ninguno de ellos recibieron quimioterapia adyuvante. De los pacientes con tumores phyllodes; 33.8% fueron benignos, 31.2% Borderline y 35.0% phyllodes maligno. Supervivencia libre de enfermedad fue 85.8% y la supervivencia global fue de 94.5%. DISCUSIÓN: Los datos reportados en este artículo están acordes con lo que se ha reportado en la literatura mundial. En nuestra cohorte, a pesar de que el tamaño promedio de los tumores fue mayor, el riesgo de recidiva local y las tasas de enfermedad metastásica es menor que el reportado previamente en la literatura. Los ensayos con seguimiento más prolongado, y los ensayos moleculares en tumores phyllodes son necesarios para comprender de una manera más precisa el comportamiento de estos tumores en la población hispana.
Assuntos
Neoplasias da Mama/patologia , Tumor Filoide/patologia , Adulto , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/cirurgia , Colômbia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Tumor Filoide/diagnóstico , Tumor Filoide/cirurgia , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
An increase in ocean noise levels could interfere with acoustic communication of marine mammals. In this study we explored the effects of anthropogenic and natural noise on the acoustic properties of a dolphin communication signal, the whistle. A towed array with four elements was used to record environmental background noise and whistles of short-beaked common-, Atlantic spotted- and striped-dolphins in the Canaries archipelago. Four frequency parameters were measured from each whistle, while Sound Pressure Levels (SPL) of the background noise were measured at the central frequencies of seven one-third octave bands, from 5 to 20 kHz. Results show that dolphins increase the whistles' frequency parameters with lower variability in the presence of anthropogenic noise, and increase the end frequency of their whistles when confronted with increasing natural noise. This study provides the first evidence that the synergy among SPLs has a role in shaping the whistles' structure of these three species, with respect to both natural and anthropogenic noise.