Biomarkers In Fish Research Articles

Biomarkers of exposure and effect in the armoured catfish Hoplosternum littorale during a rice production cycle

Fish cultivation in rice fields is a valuable resource in some rural areas of the world. Fish is a source of protein and an additional source of income for local farmers. However, the use of pesticides may impact fish and consumer health. The aim of this study was to evaluate exposure and effect biomarkers in native fish inhabiting a rice field during a production cycle. Samples of fish, water and sediment from a rice field in Santa Fe, Argentina were collected during a cultivation season (at the beginning: November 2017, in the middle: December 2017 and at the end: February 2018). At each sampling period, fish biomarkers of effect (biometric indices, hematological parameters, energy reserves, oxidative stress and neurotoxicity) were assessed together with pesticide screening in water, sediment, and fish samples. Only herbicides were present in water and sediment samples in agreement with land treatment before rice sowing stage, where only herbicides were applied. In general, the greatest water concentrations of bentazone, glyphosate and aminomethylphosphonic acid (AMPA), and the lowest sediment glyphosate and AMPA levels were observed at the beginning of the farming cycle. Fish bioaccumulated AMPA residues at all sampling periods and showed biological responses to cope with a stressful environment. Alterations in hematological parameters, mobilization of energetic reserves and activation of the antioxidant system were detected. However, no oxidative damage nor neurotoxic effects were present along the production cycle. Under a real exposure scenario, the present work demonstrates that biological changes are induced in fish to cope with stressors present in a rice field. Fish-rice coculture is an efficient and ecologically sustainable approach to increase food supplies, and a better understanding of the effect of this particular environment on fish would allow a greater and safer development of this promising productive activity in South American rice producing countries.

Vitellogenin gene expression in marine mussels exposed to ethinylestradiol: No induction at the transcriptional level

Vitellogenin (Vtg), a large multidomain protein precursor of egg-yolk proteins, is used as an endocrine disruption biomarker in fish, and in the last decades, its use has been extended to invertebrates like mollusks. However, it remains unclear whether invertebrate endocrine system produces Vtg in response to estrogens, like it occurs in oviparous vertebrates. In a previous study, no evidence of induction of Vtg expression at protein level was found in gonads of the marine mussel Mytilus galloprovincialis after exposure to the estrogenic chemical 17α-ethinylestradiol (EE2). In the present follow-up study, it was investigated whether there is any effect of EE2 on Vtg abundance at transcriptional level in M. galloprovincialis gonads. To this aim, RT-qPCR analysis targeting three different domains of Vtg transcript was performed on gonads of mussels that were exposed either 4 or 24 days to 100 ng/L EE2. In addition, several reference genes were analysed and a selection of these for potential use in further RT-qPCR analyses on mussel male and female gonads is provided. Results showed higher expression in females than in males for the three analysed Vtg domains, and no evidence of Vtg mRNA induction due to EE2 either in females or males. The present results, together with those obtained from previous analysis at protein level, support that Vtg is not an adequate biomarker for xenoestrogenicity in marine mussels. Additionally, nucleotide sequences of Vtg transcripts of three closely-related species from Mytilus edulis complex (M. galloprovincialis, M. edulis and M. trossulus) are provided and compared with Vtg sequences from other mollusk species to assess the level of conservation and evolutionary relationships among species.

Cloning, partial sequencing and 17β‐estradiol modulation of hepaticvitellogeningene of the Neotropical catfishRhamdia quelen

Expression of vitellogenin gene (vtg) is used as a biomarker for the evaluation of the exposure of estrogenic substances in fish. However, scientific information regarding this biomarker in Neotropical fish is limited. In this study, a 760 bp partial sequence of the vtg mRNA from the liver of the catfish Rhamdia quelen was cloned, representing almost 20% of the full-length vtg. The phylogenetic tree analysis recovered the vtg of R. quelen inside the clade of Siluriformes. The alignment of the deduced amino acid sequence of R. quelen vtg with other species confirmed that the described sequence is gene specific. Also, this cloned sequence presents almost 70% of identity with the vtgI subtype, that is known to translate into the incomplete form of Vtg due to the lack of the two domains, the β’-c and the Ct. Moreover, from the cloning and sequencing of vtg of R. quelen, a protocol for a RT-qPCR was developed with the goal to be applied as a biomarker of the hypothalamic-pituitary-gonad-liver (HPGL) axis, in order to evaluate the effects of endocrine disruptor exposure in Neotropical fish. Thus, this protocol was applied in the effects of a dose of 10 mg/kg of 17β-estradiol (E2) on vtg expression in male and female fish. The results showed that after 17 days of the exposure injection the E2 treatment upregulated vtg expression in both sexes. No observed differences in the levels of gene expression between the male and female fish were observed, and no statistical interaction between E2-treatment and sex were found. The results obtained from cloning add new information regarding vtg in Siluriformes fish, an order poorly studied in this aspect. Also, the vtg RT-qPCR protocol stablished for vtg of R. quelen will expand the application of this animal model, a Neotropical fish, in investigation regarding the effects of endocrine disruptors.

Contrasting fish biomarker responses between streams with different environmental conditions

Streams are environments susceptible to anthropic impacts that harm aquatic organisms by affecting their homeostasis. This study aimed to determine variations in the response of biochemical and genetic biomarkers of fish under the influence of anthropogenic impacts. For this, individuals of the tetra fish Astyanax lacustris were exposed in an impacted stream and one of its non-impacted tributaries (reference) during the dry and rainy seasons. For biochemical analyzes, we evaluated the antioxidant enzymes catalase and glutathione peroxidase and lipid peroxidation in tissue samples of gills and liver. For the genotoxicity test, we evaluated micronuclei and nuclear anomalies in blood samples. The antioxidant enzymes showed seasonal variation, regardless of the stream; lipid peroxidation didn’t differ between seasons or between streams. The frequency of micronuclei and nuclear abnormalities were more frequent in the impacted stream during the rainy season, probably in response to the leaching of toxic compounds that tends to be increased in that season. These results support the use of nuclear biomarkers in biomonitoring programs.

Antibiotics, algal evaluations and subacute effects of abattoir wastewater on liver function enzymes, genetic and haematologic biomarkers in the freshwater fish, Clarias gariepinus

Abattoirs are positioned close to freshwaters in most developing countries where untreated wastewaters are discharged into with potential risk to aquatic life such as fish and ultimately human health. We assessed physicochemical parameters, antibiotics (oxytetracycline and diclofenac) and algal load of effluent collected from a major abattoir in Nigeria. Furthermore, liver function enzymes, genotoxic and haemotoxic effects of subacute concentration (10% of 96 hLC50 value) of the wastewater were evaluated over a period of 28 d in Clarias gariepinus (The African Sharptooth Catfish). The 96 hLC50 value of the abattoir wastewater against C. gariepinus was 154.14 mL/L (15.4%). Nitrates, phosphates, sulphates, chloride, ammonia, TDS, TSS, BOD5 and heavy metals (Fe and Pb) in the wastewater were above permissible limits while diclofenac and oxytetracycline were below detection limit (BDL). Microalgae in the wastewater were mostly Bacilliariophyta (Navicula spp.) (45.64%) and euglenoids (Euglena and Phacus spp.) (49.48%). Liver function enzymes (LDH, AST, ALT) level were higher in exposed fishes except for ALP which was lower at day 28 compared to control levels. Erythrocytic genotoxic indices (nuclear abnormalities) were significantly higher (p < 0.05) in the exposed fishes particularly at day 28 compared to control. Haematologic indices level such as WBC, MCV MCH, MCHC increased significantly (p < 0.05) while lymphocytes, HGB, RBC, HCT levels decreased significantly (p < 0.05) in the exposed C. gariepinus by day 28 compared to control. These results demonstrate potential adverse effects posed to aquatic fish species in the Ogun River by the discharge of the abattoir effluent. The microalgae species identified in the effluent may be explored for pre-treatment of the effluent before discharge in order to prevent eutrophication and increased pollutant load in the River. The study results will contribute to evidence-based environmental risk management of the River which is relevant to the UN SDGs 6 (clean water and sanitation), 11 (sustainable cities and communities) and 14 (sustaining life below water).

Warming in shallow waters: Seasonal response of stress biomarkers in a tide pool fish

Tide pools are rapidly warming environments with low thermal inertia, where organisms are exposed to potentially stressful conditions. This way, tide pools will be among the first and hardest hit environments by climate warming. Studies of thermal stress in situ are rare, but important so that current thermal stress in the wild can be confirmed and serve as reference for the future. This study aims to investigate the seasonal response of stress biomarkers in a common tide pool fish, the blenny Lipophrys trigloides, under natural conditions, in situ. Multiple biomarkers of thermal and oxidative stress were analysed in the tissues of the muscle, visceral mass, gills and brain of L. trigloides, under spring (18.50 ± 0.71 °C) and summer conditions (28.30 ± 1.30 °C), in order to assess tissue-specific seasonal responses to the rapid warming that occurs seasonally in tide pools. It was concluded that L. trigloides seems to be setting in motion relevant thermal stress and antioxidant defences under summer conditions. All tissues analysed were responsive and all biomarkers of thermal and oxidative stress increased in summer conditions, with the exception of SOD, which presented no alterations. The present study offers reference values that will be useful for future comparison during particularly warm summers and in future years as climate warming progresses.

Isolation and treatments of Aeromonas hydrophila and Staphylococcus lentus implicated in the seasonal autumn mortalities of farm-raised Cyprinus carpio, Basrah governorate, Iraq

Isolation and treatments of Aeromonas hydrophila and Staphylococcus lentus implicated in the seasonal autumn mortalities of farm-raised Cyprinus carpio, Basrah governorate, Iraq

Contamination and oxidative stress biomarkers in estuarine fish following a mine tailing disaster.

BackgroundThe Rio Doce estuary, in Brazil, was impacted by the deposition of iron mine tailings, caused by the collapse of a dam in 2015. Based on published baseline datasets, the estuary has been experiencing chronic trace metal contamination effects since 2017, with potential bioaccumulation in fishes and human health risks. As metal and metalloid concentrations in aquatic ecosystems pose severe threats to the aquatic biota, we hypothesized that the trace metals in estuarine sediments nearly two years after the disaster would lead to bioaccumulation in demersal fishes and result in the biosynthesis of metal-responsive proteins.MethodsWe measured As, Cd, Cr, Cu, Fe, Mn, Pb, Se and Zn concentrations in sediment samples in August 2017 and compared to published baseline levels. Also, trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn) and protein (metallothionein and reduced glutathione) concentrations were quantified in the liver and muscle tissues of five fish species (Cathorops spixii, Genidens genidens, Eugerres brasilianus, Diapterus rhombeus and Mugil sp.) from the estuary, commonly used as food sources by local populations.ResultsOur results revealed high trace metal concentrations in estuarine sediments, when compared to published baseline values for the same estuary. The demersal fish species C. spixii and G. genidens had the highest concentrations of As, Cr, Mn, Hg, and Se in both, hepatic and muscle, tissues. Trace metal bioaccumulation in fish was correlated with the biosynthesis of metallothionein and reduced glutathione in both, liver and muscle, tissues, suggesting active physiological responses to contamination sources. The trace metal concentrations determined in fish tissues were also present in the estuarine sediments at the time of this study. Some elements had concentrations above the maximum permissible limits for human consumption in fish muscles (e.g., As, Cr, Mn, Se and Zn), suggesting potential human health risks that require further studies. Our study supports the high biogeochemical mobility of toxic elements between sediments and the bottom-dwelling biota in estuarine ecosystems.

Evaluation of hematological parameters, oxidative stress and DNA damage in the cichlid Australoheros facetus exposed to the fungicide azoxystrobin

Azoxystrobin (AZX) is a broad-spectrum systemic fungicide massively used worldwide. Its mode of action consists in the inhibition of mitochondrial respiration decreasing the synthesis of ATP and leading to oxidative stress in the target fungus. However, whether this effect occurs in non target organisms has been scarcely studied. The objectives of this work were (1) to evaluate biomarkers of oxidative stress, hematological, physiological and of genotoxicity in the native cichlid fish Australoheros facetus exposed to environmentally relevant concentrations of AZX and (2) to compare these biomarkers in different developmental stages using juvenile and adult fish (n = 6) exposed during 48 h. The exposure concentrations were 0 (negative control, C (−)), 0.05, 0.5, 5 and 50 μg/L AZX of the commercial formulation AMISTAR®. Blood was drawn to evaluate hematology, and DNA damage through the comet assay (CA) and micronucleus test (MN). Genotoxicity was observed by mean of both biomarkers in juvenile and adult fish at 50 μg/L AZX. Samples of liver and gills were used to determine antioxidant enzymes activity, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents. In juvenile fish inhibition of superoxide dismutase (SOD) was observed in liver at 0.05, 5 and 50 μg/L AZX and in gills at 5 and 50 μg/L AZX. Glutathione- S- transferases (GST) activity increased in gills at all AZX concentrations tested. In adult fish, increase of hepatic catalase (CAT) activity at 0.5 and 50 μg/L AZX and MDA content at 50 μg/L AZX were observed. In gills only H2O2 content showed changes at 50 μg/L AZX. The sensitivity showed by gills constitutes the first report about AZX toxicity in this organ. All these negative effects were observed in the range of realistic AZX concentrations, which warns of the possible consequences that it may have on the health of aquatic biota. Differences between juvenile and adult fish demonstrate the relevance of considering the developmental stage on the evaluation of biomarkers.

A multibiomarker approach in the caged neotropical fish to assess the environment health in a river of central Brazilian Cerrado

Water safety is a world-wide concern and several efforts have been made in order to ensure the conservation of aquatic ecosystems. Water quality monitoring must be performed with an integrated approach using biomonitor organisms allied to water parameters. Nonetheless, very few studies have focused on biomarker responses in neotropical fish, especially in the freshwater ecosystem of Brazilian Cerrado savanna. In present study, the active biomonitoring of the João Leite river (central Brazilian Cerrado river) was performed through the evaluation of biomarker responses in caged Astyanax lacustris in combination with land use classification and analysis of water parameters. Caged fish were exposed for seven days at four sites along the river and two control groups were kept in a tank under controlled conditions. Results showed that pasture was the predominant land use in the João Leite river basin (54.07%), followed by natural vegetation (34.92%) and other kind of land use (11.01%). Water analyses showed metal concentrations (Mn and Fe) above the maximum allowed by Brazilian regulation, with particularly higher concentrations at Site 2 (near to pasture area). Biomarker responses did not show significant differences for somatic and mutagenic biomarkers between sites. However, the comet assay showed high DNA damage at Sites 2 and 3, indicating genotoxic effects in caged fish at pasture areas. Histopathological analysis showed highest frequency of leukocyte infiltration in liver of fish from Site 2, confirming the ecotoxic effects on A. lacustris in streams impacted by grazing activities. DNA damage and leukocyte infiltration in fish hepatic tissues were sensitive biomarkers in the neotropical fish A. lacustris to assess the environment health of the Cerrado river. These results showed the importance of using a multibiomarker approach in environmental risk assessment, especially in areas more at risk from anthropogenic pollution.

Do food and stress biomarkers work for wastewater-based epidemiology? A critical evaluation

Dietary characteristics and oxidative stress are closely linked to the wellbeing of individuals. In recent years, various urinary biomarkers of food and oxidative stress have been proposed for use in wastewater-based epidemiology (WBE), in efforts to objectively monitor the food consumed and the oxidative stress experienced by individuals in a wastewater catchment. However, it is not clear whether such biomarkers are suitable for wastewater-based epidemiology. This study presents a suite of 30 urinary food and oxidative stress biomarkers and evaluates their applicability for WBE studies. This includes 22 biomarkers which were not previously considered for WBE studies. Daily per capita loads of biomarkers were measured from 57 wastewater influent samples from nine Australian catchments. Stability of biomarkers were assessed using laboratory scale sewer reactors. Biomarkers of consumption of vitamin B2, vitamin B3 and fibre, as well as a component of citrus had per capita loads in line with reported literature values despite susceptibility of degradation in sewer reactors. Consumption biomarkers of red meat, fish, fruit, other vitamins and biomarkers of stress had per capita values inconsistent with literature findings, and/or degraded rapidly in sewer reactors, indicating that they are unsuitable for use as WBE biomarkers in the traditional quantitative sense. This study serves to communicate the suitability of food and oxidative stress biomarkers for future WBE research.

Transcriptional responses in newly-hatched Japanese medaka (Oryzias latipes) associated with developmental malformations following diluted bitumen exposure

Japanese medaka embryos were exposed to water accommodated fractions (WAF) and chemically-enhanced WAF of two types of diluted bitumen (dilbit) at concentrations bracketing the EC50s for developmental malformations. Within these treatments, fish were grouped based on the presence or absence of developmental malformations (e.g., blue sac disease (BSD)), and analyzed for novel transcriptomic responses. Microarray analyses identified novel biomarkers and gene networks in dilbit-exposed malformed embryos that were not evident in dilbit-exposed fish without BSD or in controls without dilbit. The top differentially expressed genes (DEGs) included cytochrome P450 transcripts (cyp1) in fish from all dilbit treatments (malformed and non-malformed fish), as well as: fibroblast growth factor (fgf7), AHR repressor (ahrr), and squalene monooxygenase (sqle). In dilbit-exposed fish that did not develop BSD, the only reported individual DEG was eukaryotic translation initiation factor 3 subunit D (eif3d). However, a number of other pathways were enriched, including melatonin effects on circadian clock and the antioxidant response, estrogen and androgen metabolism as well as many receptor signaling pathways. Pathways associated with hedgehog, steroid biosynthesis, and Wnt signaling were significantly altered between low and high concentrations of dilbit exposure. An effect of the dispersant control on swim bladder development was observed at concentrations 10-fold higher than those used to disperse dilbit, and a number of gene targets unique to fish in this comparison were affected. This suggests that the toxic effects of dispersant may involve alternative mechanisms to dilbit, but cause similar phenotypic responses. This study identified novel biomarkers in fish exposed to dilbit, with or without visual malformations, that can be used to assess the risks of dilbit to aquatic ecosystem health.

Heavy metal toxicity and the influence of water quality in watershed for enhancing fisheries food security

This study investigated the toxicity of heavy metals such as Cu, Fe, Cr, Zn and Mn and the influence of water quality in Garang Watershed Semarang (Banjir Kanal Barat River), Central Java Indonesia for enhancing fisheries food security. The fish biomarker in this research is Nile Tilapia (Oreochromis niloticus). The range of Cu, Fe, Cr, Zn and Mn in aquatic environment were 0,15 mg/L; 0,82 mg/L; 0,025 mg/L; 0,562 mg/L and 0,01mg/L. The range of Cu, Fe, Cr, Zn and Mn in Nile Tilapia were 2,547 mg/kg; 306,3 mg/kg; 0,36 mg/kg; 16,69 mg/kg and 35,6 mg/kg. Toxicity in fish is exceeded the limits of food security regulation in WHO and BPOM, and water quality regulation in Government Regulation of Indonesia No 82/2001 on Water Quality And Water Pollution Management. Management in water quality is and toxicity is important for enhancing fisheries food security. Maintaining food security in the fishery sector is very important for the stability of community nutrition because with good food public health will be guaranteed.

An active biomonitoring approach using three-spined stickleback (Gasterosteus aculeatus, L.) to assess the efficiency of a constructed wetland as tertiary treatment of wastewater

The present work aimed to assess the efficiency of a constructed wetland as tertiary treatment on urban wastewater with a multibiomarker approach using caged three-spined sticklebacks (Gasterosteus aculeatus L.). Fish were caged on three sites: at the entrance of the Constructed Wetland (CW), directly inside the wastewater effluent, at the exit of the CW, and in a weakly impacted site considered as a reference. After 21 days of caging, sticklebacks state of health was assessed using several biomarkers representing some biological functions such as innate immune and antioxidant systems, biotransformation enzymes, reproduction parameters and synaptic transmission. A strong inhibition of the innate immune system, an induction of EROD activity and an alteration of the hepatosomatic index were observed in fish caged at the entrance of the CW compared to those caged in the reference site. In addition, wastewater effluent induced a decrease of antioxidant system without induced oxidative damage on cell membranes. No improvement of these biomarkers was observed for antioxidant parameters at the exit of the CW. However, in fish caged at the exit of the CW, the EROD induction observed at the entrance was reduced and the innate immune system presented the same level compared to fish caged in the reference site, underlying the beneficial effect of the CW for these parameters. Integrated Biomarker response (IBR) was equal to 25.2 at the entrance of the CW and 17.4 at the exit of the CW which highlighted the global positive effect of the CW on water quality based on fish biomarker measurement.

Fish biomarkers from a different perspective: evidence of adaptive strategy of Abramis brama (L.) to chemical stress

BackgroundA prerequisite for long-term survival of populations under multi-stress conditions is their capacity to set up efficient adaptive strategies. However, changes in the activity of molecular biomarkers have been for decades considered as early signals of the deterioration of the fish health and evidence of stress-related adverse biological effects. The aim of this study was to show that such changes actually represent adaptive response of fish to chemical stress. Gene expression and enzyme activity level in liver and brain of specimens from two populations of Abramis brama from contrasted habitats (nature reserve and urban) were examined. Selected parameters included biomarkers of general stress, antioxidative defence, xenobiotic metabolism, endocrine disruption, glucose homeostasis, iron homeostasis, and neurotoxicity.ResultsExposure of A. brama population from urban area to chemical stress was confirmed by assessment of chronic toxic pressure at fish habitats using Toxic Unit approach. The most pronounced response to chemical stress is observed through the activation of antioxidative defence mechanisms in brain and liver at gene and enzyme activity level, high biotransformation capacity of liver, and activation of mechanisms that will meet energy demands and compensate for the metabolic costs of the response to toxicants (higher expression of genes related to glucose homeostasis in the exposed population). Higher hepatosomatic index in the exposed population implies liver hypertrophy due to increased functional load caused by pollution. Body condition factors indicate good overall condition of both fish populations and confirm high efficacy of mobilized adaptation mechanisms in the exposed population.ConclusionsThe study provided the first data on basal expression of a number of genes in A. brama, potentially valuable for biomonitoring studies in absence of clear pollution gradient and/or reference sites (conditions). The study highlights importance of newly identified roles of various genes and proteins, typically considered as biomarkers of effects, and shows that changes in these parameters do not necessarily indicate the deterioration of the fish health. Such changes should be considered as adaptive response to chemical stress, rather than direct proof of ecological impact of pollution in situ.

Assessment of River Water Quality in an Agricultural Region of Brazil Using Biomarkers in a Native Neotropical Fish, Astyanax spp. (Characidae).

Intensive agricultural and livestock activities demand high pesticide use and, consequently, contaminants reach aquatic ecosystems. In the lower Jacuí River, southern Brazil, there is a lack of knowledge about pesticide residues in water samples and the biochemical responses in native fish species. Thus, this study aimed to estimate the influence of pesticide residues and water parameters to biomarker responses in the native fish Astyanax spp. We performed seasonal biomonitoring in 2017 with water samples and fish collections. Biomarkers of oxidative stress, antioxidants, biotransformation, and neurotoxicity were analyzed in fish tissues. Fourteen pesticide residues were detected; they presented correlations with detoxification enzyme and oxidative stress biomarkers. These data indicate that most of variations can be related to the pesticide presence in water indicating high aquatic pollution in this place.

No evidence that vitellogenin protein expression is induced in marine mussels after exposure to an estrogenic chemical

A wide variety of endocrine disrupting chemicals reach the marine environment and can cause harmful effects in different marine organisms. Vitellogenin (Vtg), the egg-yolk precursor, is a commonly used endocrine disruption biomarker in fish and more recently in marine invertebrates under the assumption of high expected similarities in the endocrine system of vertebrates and invertebrates. However, this assumption has been recently questioned. The results from previous studies focused on bivalve molluscs showed that Vtg induction could be misleading because of the use of either non-robust or indirect techniques to measure Vtg. In this study, mussels (Mytilus galloprovincialis) were exposed to either 10 or 100 ng/L of the synthetic hormone 17α-ethinylestradiol (EE2) at different exposure times (4 and 24 days) and under different feeding regimes (representing different energy balances), and Vtg levels in both male and female mussel gonads were quantified by label free shotgun LC-MS/MS proteomic analysis. Vtg protein was not detected in male gonads. In female gonads, Vtg levels were not significantly affected by EE2 at any exposure time or EE2 concentration tested, whereas a significant correlation was found between the degree of maturation of the gonad and Vtg levels in females. Results obtained in the present study critically question the use of Vtg as a biomarker of endocrine disruption in marine mussels, and show that the degree of maturation of the gonad can be an important confounding factor in the attempts to evaluate estrogenic effects through Vtg measurement in mussel gonads.

Fish inhabiting rice fields: Bioaccumulation, oxidative stress and neurotoxic effects after pesticides application

Abstract The present study aimed to evaluate the biological effects triggered by the application of a current-use mixture of pesticides (the herbicide glyphosate, the insecticide bifenthrin, BF, and the fungicides azoxystrobin, AZ, and cyproconazole, CYP) on two native fish (Markiana nigripinnis and Astyanax lacustris) inhabiting a rice field. We analyzed pesticide residues in water, sediment and fish samples 21 days before and after a fumigation event. Additionally, organismic indices, oxidative stress and neurotoxicity biomarkers in fish at both sampling periods were compared. After fumigation, glyphosate, BF, AZ and CYP were detected in water and sediment samples, being also bioaccumulated in both fish species. A decreasing condition factor in A. lacustris and a higher liver somatic index in M. nigripinnis were observed as well. Overall, results showed that, after the application of the pesticide mixture, antioxidant mechanisms failed to prevent oxidative damage in the liver and gills of M. nigripinnis. Meanwhile, A. lacustris showed a different response: an inhibition of the antioxidant defenses without tissue lipid oxidative damage. Furthermore, acetylcholinesterase activity after spraying was significantly reduced in brain and muscle tissues of A. lacustris and in the brain of M. nigripinnis. Our results show that current-use pesticides, like glyphosate, BF, AZ and CYP, pose health risks on native fish populations inhabiting rice fields.

Abstract P4-01-13: Clinical data in over 1,500 breast cancer patients across all stages of breast cancer with target selector circulating tumor cell technology

Abstract Clinical Data in Over 1,500 Patients Across All Stages of Breast Cancer with Target Selector Circulating Tumor Cell Technology Deanna M Fisher B.S., Lan Huynh B.S., Edgar V. Sales B.S., Julie Ann Mayer Ph.D., and Veena M. Singh M.D. Introduction: The detection and molecular characterization of circulating tumor cells (CTCs) in patients with breast cancer affords the ability to profile and monitor patients in real time for progression, risk stratification, recurrence, identification of potentially actionable therapeutic targets, and monitoring of treatment efficacy and emergence of resistance mechanisms. To harness the promise of CTC analysis a highly sensitive, robust, reproducible and clinically validated technology is required. Information acquired from a single tissue biopsy has temporal and spatial limitations; additionally, in patients with progressive/metastatic disease, a single biopsy may not be informative or in some instances difficult to perform and might fail to reflect inherent tumoral heterogeneity. CTCs on the other hand can provide a contemporaneous landscape of all cancerous lesions (primary and metastases) as well as the opportunity to track the evolving tumor genetic mechanisms. Methodology:Samples were collected in CEE Sure blood collection tubes and buffy coat isolation was performed using a percoll density gradient separation. Capture in the microchannel was performed after incubation with a ten-antibody capture cocktail followed by the addition of a biotinylated secondary antibody. The microchannels were stained with pan-cytokeratin cocktail, CD45, pan-CTC stain, DAPI and the following protein biomarkers (AR, ER, PR, and PDL1). Following enumeration of the CTCs, the microchannels were subsequently sent for multi-color FISH biomarkers such as HER2. Results: 1,687 patients across all stages of breast cancer and treatment time points (pre- treatment, post-treatment, on treatment) were analyzed. CTCs were detected up to 70% of the time across early to late stage patients. The dynamic range of CTC detection and enumeration in a single microfluidic channel (8mL blood) ranged from 1 to 38,419 CTCs. CTC detection has been previously validated to a 1 CTC limit of detection. CTCs identified varied in both size and antigen profile. Target Selector CTC platform technology identifies both cytokeratin positive and cytokeratin negative phenotypes of CTCs. Biomarker interrogation was undertaken in all CTC subtypes by FISH probes (Fluorescent in situ hybridization) and ICC (Immunocytochemical) antibody clones similar to those used on tissue sections. Genomic alterations commonly detected in breast cancer (i.e. HER2 amplification, ER) were detected in all CTC subtypes. HER2 amplification was identified in 15% of cases with CTCs detected and ER in 24 %. Conclusions: This data demonstrates the ability of the Target Selector CTC Platform to accurately detect, enumerate, and interrogate for genomic alteration across a broad spectrum of CTC phenotypes spanning various clinical and treatment stages. This enables clinicians and patients a more real time option to profile and monitor disease. The Target Selector CTC technology allows for the analysis of a broader spectrum of CTC phenotypes thus increasing the likelihood of identifying actionable biomarkers for risk stratification, recurrence, potential treatment selection and monitoring for emergence of resistance. Citation Format: Deanna M Fisher, Lan Huynh, Edgar V Sales, Julie Ann Mayer, Veena M Singh. Clinical data in over 1,500 breast cancer patients across all stages of breast cancer with target selector circulating tumor cell technology [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-01-13.

Developmental toxicity of copper in marine medaka (Oryzias melastigma) embryos and larvae

Copper as developmental toxicants have been reported extensively in freshwater fish, however, the sublethal and chronic toxic effects of Cu to the early life stages of marine fish are not clear. Embryo (3–5 hpf) and newly hatched larvae of marine medaka (Oryzias melastigma) were exposed to 0.01–1.28 mg L−1 waterborne Cu to investigate the developmental toxic effects. The results showed that Cu accumulation in the whole embryos presented a dose- and time-response increase while it decreased dramatically once hatching. Most of Cu accumulated in the chorion suggests that chorion is an effective barrier to Cu absorption. However, Cu that penetrated chorion and entered embryo still caused significant lethal and sublethal effects. Cu concentrations at ≥0.16 mg L−1 led to low hatchability, delayed hatching, high mortality, morphological abnormalities and increased egg size in the embryos. Heart beats and the total body length of the newly hatched larvae were significantly increased when exposed to ≥0.02 mg L−1. Cu exposure accelerated early development and promoted or delayed hatching of embryo. High Cu concentration (≥0.16 mg L−1) exposure induced morphological abnormalities of embryo and larvae, particularly skeletal and vascular system abnormalities and reduction of pigmentation. The 30 d-LC50 for embryo development was 0.138 mg L−1 and 7d LC50 for larvae survival was 10.15 mg L−1, demonstrating that embryos were more sensitive to Cu than larvae. In summary, O. melastigma embryos development is highly sensitive to Cu exposure, and the sublethal effects occurred at low Cu concentration might be as potential biomarkers in marine fish.