Search

As filter feeders, mollusks' growth is completely reliant on the natural environment. This leaves clam aquaculture, and more generally molluskan aquaculture, highly susceptible to environmental risks such as harmful algal blooms (HABs) and low salinity events. As marine environments change, whether due to climatic or nutrient related variations, there may be new risk combinations that farmers have yet to encounter. To analyze the financial effects of environmental risks on clam farmers in the Gulf of Mexico, we conducted a Monte–Carlo experiment, varying risk combinations and correlations among scenarios. Simultaneous stressors showed a significant impact on individual firms, decreasing average profit by 71% and internal rate of return (IRR) by 83% when compared to best case baseline scenarios without environmental risk, indicating a potential need for risk mitigation strategies. While our analysis focuses on Florida Gulf of Mexico clam farmers, the model presented is applicable to molluskan aquaculture globally. [ABSTRACT FROM AUTHOR]

We present the results of a prospective, non-randomized phase 2 trial in which 253 AML patients (pts) under 60 years old received DAC (Daunorubicin + AraC + Cladribine) as first induction followed by CLAM (Cladribine + AraC + Mitoxantrone) as early second induction on day 16 based on bone marrow (BM) blasts on day 14 (D14). The CR/CRi rate after a single course of DAC was 83% for pts with D14 BM blasts less than 10%. Forty-six pts had >10% BM blasts on D14, of whom 35 received CLAM with rates of CR/CRi 60% and early death (ED) 23%. The remaining 11 pts were not fit to receive CLAM, with rates of CR/CRi 28%, PR 18%, and ED 18%. Median OS was 7.2 versus 7.5 months, respectively. The overall CR/CRi rate was 77% after the first induction, with final CR/CRi rate 80% after DAC reinduction for pts who achieved PR with initial DAC course. CLAM used as early second induction might improve CR/CRi rates for younger AML pts with poor early response to DAC induction, but may be associated with higher mortality. [ABSTRACT FROM AUTHOR]

Objectives: Third line treatment of urge urinary incontinence (UUI) and/or reduced bladder capacity is bladder augmentation. The aim of this study was to investigate whether clam enterocystoplasty (CECP) was an efficient treatment for patients who were refractory to conservative treatments of UUI and small functional bladder capacity and secondly if there was a difference in outcome in patients with neurogenic and non-neurogenic bladders. Methods: We evaluated 118 patients retrospectively treated in the period 2006–2018 at a single university hospital. Data were collected retrospectively. Patient groups were compared with Wilcoxon signed-rank test and Fisher's exact test. Results: Overall, 76% became continent with 92% using clean intermittent self-catherization (CISC) of patients with neurogenic bladder, 82% became continent and 100% were using CISC, whereas of patients with non-neurogenic bladder 64% became continence and 77% were using CISC. The median overall improvement of capacity was 296.5 mL (IQR: 142–440), 310 mL (186–467) in the neurogenic group and 214 mL (IQR: 126.8–361.5) in non-neurogenic (p = 0.01). Conclusion: CECP is an efficient treatment in UUI and reduced bladder capacity. Difference in outcome was seen with neurogenic patients having a bigger functional capacity and a higher rate of continence compared to the non-neurogenic. [ABSTRACT FROM AUTHOR]

Bivalves in estuaries are exposed to many environmental variables but little is known about how such variables, including reduced salinity, affect reproduction and growth in burrowing clams. These were measured in the New Zealand little-neck clams, Austrovenus stutchburyi, from one urban and three rural estuaries with different contaminant inputs. Two shellfish sites were selected within each estuary reflecting high- and low-salinity exposure. Reproductive activity was seasonal and similar amongst the estuarine systems. The gravimetric condition index (CI) of the clams decreased significantly on exposure to low-salinity regimes. The gonad index increased significantly with CI and per cent glycogen in the foot tissue. At most sites, shell length increased significantly with the age of the clam, and maximum shell length and growth was reduced in clams exposed to the low-salinity regime. Reproductive indices of the clams did not correlate with sediment characteristics or sediment trace metal pollution index. It was concluded that salinity was the main factor affecting shellfish condition and that seasonal CI measurements could be a good indicator of growth and reproductive success. This knowledge is useful for the future management of this and other similar shellfish species. [ABSTRACT FROM AUTHOR]

Biomarkers have been tested in order to address the most suitable battery for determining adverse effects of crude oil spills on marine invertebrates. An oil spill with increasing degrees of severity was simulated by mixing crude oil (0%, 0.5%, 2%, 8%, 16%, 32%) with sediment. Carcinus maenas and Ruditapes philippinarum were exposed to this sediment for seven days with the aim of comparing their applicability in biomonitoring studies. Four biomarkers including ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST), glutathione peroxidase (GPx) and lipid peroxidation (LPO) were analysed in gill and digestive gland tissues of clams; and in gill and hepato-pancreas tissues of crabs. EROD, GST and GPx enzymatic activities were significantly induced in gill and digestive gland tissues of clams when increasing oil concentrations (p<.01). In crabs all the biomarkers were significantly activated in gill tissues, whereas EROD and LPO activities were induced only in hepato-pancreas tissues (p<.01). Gill and digestive gland in clams and gill in crabs were found to be the most reliable tissues for analysis of biomarkers. The biomarkers selected are thus considered suitable for assessing toxicity of sediments after a marine crude oil spill accident. Both species were found to be sensitive and suitable for biomonitoring purposes. [ABSTRACT FROM AUTHOR]

The effects of γ -irradiation on the destruction of Vibrio vulnificus in quahog clam tissue (Mercenaria mercenaria) by real-time PCR (Rti-PCR) were studied. The Rti-PCR methodology used in this study employed four sets of V. vulnificus specific primers, which were utilized to amplify 1000, 700, 300, and 70-bp sequences of the vvhA to determine the percent detection of V. vulnificus genomic targets after γ -irradiation. Tissue homogenates seeded with V. vulnificus were irradiated to gradually reduce the viable CFU by accumulating dosage. The use of these four pairs of primers to amplify DNA target sequences of varying length in seeded tissue exposed to 1.4 KGy failed to discriminate between irradiated and nonirradiated cells. In contrast, with doses of 2.0, 3.0, and 5.0 KGy, the amplification of 700, 300, and 70-bp sequences resulted in higher Ct values, respectively, and lower levels of amplification with each primer pair, reflecting increased DNA fracture with increasing dose. When varying numbers of CFU in tissue homogenates (1.0 × 103 to 1.0 × 106 per gram of tissue) were exposed to 3.0 KGy of γ-irradiation, DNA amplicons of 1000 and 700-bp derived from 1 × 105 CFU/g and below failed to be detected in contrast to 300 and 70-bp amplicons, which were detected with CFU levels of 1.0 × 105/g. This study showed that with increasing dose, the larger amplicons (100 and 700-bp) failed to be detected, which corresponded to zero percent survival of CFU. [ABSTRACT FROM AUTHOR]

Molluscs, due to their filtrant capacity, can accumulate metals arriving to contaminate the foods and as consequence they can have a negative repercussion on the health of the consumers. In this study the content of some metals (Cu, Zn, Cd and Pb) in clam samples commercialized in Galicia (NW Spain), in tinned products as well as in fresh products, has been determined. For the analysis an anodic stripping voltammetry technique has been employed in order to obtain the metal levels in muscle and liver. Results have been statistically treated in order to evaluate the correlations between heavy metal content into the different established portions. It's interesting to emphasize the higher concentrations in liver that in muscle for zinc, lead and copper in fresh samples. Thus, the maximum values in fresh clam liver were for Zn: 1246.20 mg/kg; for Pb: 15.60 mg/kg and for Cu: 75.04 mg/kg, set against the maximum values of Zn (60.36 mg/kg), Pb (0.67 mg/kg) and Cu (9.48 mg/kg), in muscle. With respect to cadmium, in general, tinned products presented higher concentrations than the fresh ones, reaching one of them till 8.11 mg/kg, in the liver. Taking into account the importance of these molluscs in food and according to the outstanding legislation, it has been able to establish, from the toxicological point of view, that metal levels do not constitute a risk for human health. © 2005 Altaga. All rights reserved. Resumen Los moluscos, debido a su capacidad filtrante, pueden acumular metales llegando a contaminar los alimentos y como consecuencia pueden tener una repercusión negativa sobre la salud de los consumidores. En este estudio se han determinado los contenidos de algunos metales (Cu, Zn, Cd y Pb) en muestras de almejas comercializadas en Galicia (España) tanto en conserva como en fresco. Para su análisis se ha empleado la voltamperometría de redisolución anódica, obteniéndose los niveles de dichos metales en músculo y en hepatopáncreas. Los resultados han sido tratados estadísticamente para evaluar las posibles correlacciones en el contenido de metales en las distintas porciones anatómicas establecidas. Destacan las concentraciones mucho más elevadas en hepatopáncreas que en músculo para zinc, plomo y cobre en muestras en fresco. Así, los máximos en hepatopáncreas de almejas en fresco fueron para Zn: 1250 mg/kg; para Pb: 15,60 mg/kg y para Cu: 75,04 mg/kg, frente a los máximos de Zn (60,36 mg/kg), Pb (0,67 mg/kg) y Cu (9,48 mg/kg), en músculo. En cuanto al cadmio, en general las muestras en conserva presentaron concentraciones más elevadas que las muestras en fresco, llegando a alcanzar el hepatopáncreas de una de ellas hasta 8,11 mg/kg. Teniendo en cuenta la importancia de estos moluscos en la alimentación y de acuerdo con la legislación vigente, se ha podido establecer, desde el punto de vista toxicológico, que los niveles de estos metales no suponen riesgo para el consumidor. © 2005 Altaga. Todos los derechos reservados. Palabras clave: Almeja, voltamperometría, metal, zinc, cadmio, plomo, cobre. Resumo Os moluscos, debido á súa capacidade filtrante, poden acumular metais pesados chegando a contamina-los alimentos e como consecuencia poden ter unha repercusión negativa sobre a saúde dos consumidores. Neste estudio determináronse os contidos dalgúns metais (Cu, Zn, Cd e Pb) en mostras de ameixas comercializadas en Galiza, tanto en conserva como en fresco, empregando unha técnica de voltamperometría de redisolución anódica, obténdose os niveis de ditos metais no músculo e no hepatopáncreas. Os resultados foron tratados estatísticamente para avalia-las posibles correlacións no contido de metais nas distintas porcións anatómicas establecidas. Salientan as concentracións moito mais elevadas en hepatopáncreas que en músculo para zinc, chumbo e cobre en mostras en fresco. Así, os niveis máximos en hepatopáncreas das ameixas en fresco foron para Zn: 1246,20 mg/kg; para Pb: 15,60 mg/kg e para Cu: 75,04 mg/kg, fronte os máximos de Zn (60,36 mg/kg), Pb (0,67 mg/kg) e Cu (9,48 mg/kg), en músculo. En canto ó cadmio, en xeral, as mostras en conserva presentaron concentracións mais elevadas que as mostras en fresco, chegando a acadar unha delas 8,11 mg/kg no hepatopáncreas. Dacordo coa lexislación vixente e dende o punto de vista toxicolóxico, puido establecerse que os niveis de metais pesados cuantificados non supoñen risco para a saúde do consumidor. © 2005 Altaga. Tódolos dereitos reservados. Palabras clave: Ameixa, voltamperometría, metal, zinc, cadmio, chumbo, cobre. [ABSTRACT FROM PUBLISHER]

Tinned molluscs are specially affected by toxicological problems associated to heavy metal levels in foods, due to the filtrant capacity of these species. At the present work, concentrations of two heavy metals, lead and cadmium, in different tinned clam, common cockle and razor shell commercialized in Spain have been determined. Heavy metal concentrations in muscle, liver and liquid have been determined by means of dry digestion and anodic stripping voltammetry. Results have been statistically treated in order to evaluate the correlations between heavy metal content into the different established portions. With respect to lead, higher concentrations were quantified in liver samples (mainly those corresponding to common cockle), whereas for cadmium only razor shell samples showed a clear accumulation into liver. According to levels set by legislation, it has been established that heavy metal concentrations in tinned products do not constitute a risk for human health. © 2004 Altaga. All rights reserved. Resumen Las conservas de moluscos son especialmente sensibles a la problemática toxicológica causada por los metales pesados en los alimentos, por la capacidad filtrante de estos animales. En el presente estudio se han determinado los niveles de dos metales pesados, plomo y cadmio, en distintas conservas de almeja, berberecho y navaja, comercializadas en España. Empleando la digestión por vía seca, y por medio de una técnica de voltamperometría de redisolución anódica, se han analizado los niveles de ambos xenobióticos en el músculo y el hepatopáncreas de estos animales, así como en el líquido de cobertura. Los resultados han sido tratados estadísticamente para evaluar las posibles correlaciones en el contenido de metales en las distintas porciones anatómicas establecidas. Con respecto al plomo, destacan las mayores concentraciones alcanzadas en las muestras de hepatopáncreas (en especial para los berberechos), mientras que en el caso del cadmio esta distribución no ha sido tan homogénea, y tan sólo las navajas presentaron una tendencia acumuladora de este metal en el hepatopáncreas. De acuerdo a la legislación vigente se ha podido establecer que los niveles de metales pesados cuantificados no suponen riesgo para la salud del consumidor. © 2004 Altaga. Todos los derechos reservados. Palabras clave: Metal, plomo, cadmio, conserva, almeja, berberecho, navaja Resumo As conservas de moluscos son especialmente sensibles á problemática toxicolóxica causada polos metais pesados nos alimentos, pola capacidade filtrante destes animais. No presente estudio determináronse os niveis de dous metais pesados, chumbo e cadmio, en distintas conservas de ameixa, berberecho e navalla, comercializadas en España. Empregando a dixestión por vía seca, e por medio dunha técnica de voltamperometría de redisolución anódica, analizáronse os niveis de ámbolos dous xenobióticos no músculo e o hepatopáncreas destes animais, así coma no líquido de cobertura. Os resultados foron tratados estatísticamente para evaluar as posibles correlacións no contido de metais nas distintas porcións anatómicas establecidas. Con respecto ó chumbo, salientan as maiores concentracións acadadas polas mostras de hepatopáncreas (en especial para os berberechos), mentres que no caso do cadmio esta distribución non foi tan homoxénea, e tan só as navallas amosaron unha tendencia acumuladora dese metal no hepatopáncreas. Dacordo coa lexislación vixente puido establecerse que os niveis de metais pesados cuantificados non supoñen risco para a saúde do consumidor. © 2004 Altaga. Tódolos dereitos reservados. Palabras chave: Metal, chumbo, cadmio, conserva, ameixa, berberecho, navalla [ABSTRACT FROM PUBLISHER]

Metals are known to influence the oxidative status of marine organisms, and antioxidant enzymes have been often proposed as biomarkers of effect. The clam Ruditapes decussatus is a well-known metal bioindicator. In this species cadmium (Cd) induces metallothionein (MT) synthesis only after 7 days of exposure. Before MT synthesis is induced, the other mechanisms capable of handling the excess of Cd are unknown. In order to identify some of these mechanisms, variations in antioxidant systems (superoxide dismutase, catalase, selenium-dependent glutathione peroxidase and non-selenium-dependent glutathione peroxidase), malondialdehyde (MDA) and MT were studied in the gills of R. decussatus exposed to different Cd concentrations (4, 40 and 100 gl[sup -1]) for 28 days. These parameters, together with total proteins and Cd concentrations, were measured in the gills of the clams over different periods of exposure. Results indicate that Cd accumulation increased linearly in the gills of R. decussatus with the increase in Cd concentration. This increase induces an imbalance in the oxygen metabolism during the first days of Cd exposure. An increase in cytosolic superoxide dismutase (SOD) activity and a decrease in mitochondrial SOD activity was observed at the same time as or after a decrease in cytosolic and mitochondrial catalase activity and of selenium-dependent and non-selenium-dependent glutathione peroxidase activity. After 14 days of exposure, Cd no longer affect these enzymes but there was elevation of other cellular activities, such as MDA and MT production. MT bound excess Cd present in the cell. These variations in these parameters suggest their potential use as biomarkers of effects such as oxidative stress resulting from Cd contamination in molluscs. [ABSTRACT FROM AUTHOR]

The uptake of 14C-chlorpyrifos by clams (Katalysia opima) was studied to determine the bioaccumulation potential over a period of five days. Chlorpyrifos was applied to a model ecosystem in beakers at the rate of 3 mg l-1 of seawater. Clams showed a maximum uptake of 14C-chlorpyrifos in the first 8 hours of exposure. Subsequently these residues decreased significantly and at the end of 5 days about 1.5% of the applied activity could be recovered from the clam samples. The half-life of chlorpyrifos in this marine water system was about a day. However, after 5 days about 28% of the applied 14C-activity was present in water. This may be significant and could possibly play a role in finding the residue of this insecticide in water bodies. Clams brought about rapid degradation of chlorpyrifos in the first 48 hours. The stabilised residues in water were reflected later in clams. [ABSTRACT FROM AUTHOR]