scholarly journals Questions of control of hormone content in fish and other aquatic organisms (metaanalysis)

2021 ◽  
Vol 37 ◽  
pp. 00039
Author(s):  
Olga Bagryantseva ◽  
Vladimir Skakun ◽  
Ilya Sokolov ◽  
Zinaida Gureu
Keyword(s):  
Endocrine System ◽  
Aquatic Organisms ◽  
Accurate Method ◽  
Sensitivity Threshold ◽  
Feed Conversion ◽  
Carcinogenic Effect ◽  
Safety Regulations ◽  
Highly Sensitive ◽  
Synthetic Hormones ◽  
Fish And Fishery Products

Between 1995 and 2018, the production of fish and fishery products using feed increased from 12 to 54.3 million tons. In the cultivation of such products in many countries, hormones are widely used as growth stimulants to increase the efficiency of feed conversion for the purpose of sex reversal, as well as for artificial reproduction. Hormones, especially their synthetic forms, are poorly metabolized in the marine organisms, which leads to their accumulation in the food matrix. When they enter the human body, they are capable of accumulation in tissues, affect the endocrine system and can cause the development of a number of metabolic disorders. The possibility of a carcinogenic effect of hormones has been proven. The data presented substantiate the need to control the content of hormones in fish and fish products, develop highly sensitive methods for their detection, establish a list of controlled hormones and hormone-like drugs and safety regulations for food products produced with their use. The most sensitive and accurate method in this case is the HPLC-MS/MS method. We believe that for natural (non-synthetic hormones) and synthetic hormones, the criterion for their absence in the sample should be the sensitivity threshold of the used research method (at least 20 ng/kg).

scholarly journals On the mechanism of boundary lubrication. II. Wear prevention by addition agents

1940 ◽  
Vol 177 (968) ◽  
pp. 103-118 ◽  
Keyword(s):  
High Pressures ◽  
Preceding Paper ◽  
Accurate Method ◽  
Polar Compounds ◽  
Experimental Conditions ◽  
Group V ◽  
Highly Sensitive ◽  
Local Pressures ◽  
Steel Balls ◽  
Long Chain

If two metal surfaces slide over each other in the presence of a lubricant and under high load, high pressures and temperatures prevail a t those isolated spots which actually carry the load, leading to wear and possibly to breakdown. The action of wear preventing agents under these conditions has been studied in detail and it has been found that such agents are effective through their chemical polishing action, by which the load becomes distributed over a larger surface and local pressures and temperatures are decreased. Especially effective are compounds containing phosphorus or other elements of group V of the periodic system. These have been found to form a metal phosphide or homolog on the surface which is able to alloy with the metal surface, lowering its melting point markedly, and by this action aiding greatly in maintaining a polish. The wear experiments were carried out with a highly sensitive and accurate method which uses metal-plated steel balls as its sliding elements. Under the experimental conditions additions of 1.5% triphenyl phosphine or triphenyl arsine in white oil gave wear prevention factors of 7.2 and 12.2 respectively (relative to pure white oil). A further addition of 1% of a long chain polar compound is able to double the wear prevention factor obtained with the polishing agents and wear prevention factors as high as 17.6 have been observed. The specifically physical action of the long-chain polar compounds is discussed in the preceding paper.

A rapid and accurate method for screening T-2 toxin in food and feed using competitive AlphaLISA

2021 ◽  
Vol 368 (6) ◽  
Author(s):  
Liwen Zhang ◽  
Qingyu Lv ◽  
Yuling Zheng ◽  
Xuan Chen ◽  
Decong Kong ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Accurate Method ◽  
Detection Methods ◽  
Cereal Crops ◽  
Detection Range ◽  
Highly Sensitive ◽  
Food And Feed ◽  
Good Repeatability ◽  
Feed Samples ◽  
Better Than

ABSTRACT T-2 is a common mycotoxin contaminating cereal crops. Chronic consumption of food contaminated with T-2 toxin can lead to death, so simple and accurate detection methods in food and feed are necessary. In this paper, we establish a highly sensitive and accurate method for detecting T-2 toxin using AlphaLISA. The system consists of acceptor beads labeled with T-2-bovine serum albumin (BSA), streptavidin-labeled donor beads and biotinylated T-2 antibodies. T-2 in the sample matrix competes with T-2-BSA for antibodies. Adding biotinylated antibodies to the test well followed by T-2 and T-2-BSA acceptor beads yielded a detection range of 0.03–500 ng/mL. The half-maximal inhibitory concentration was 2.28 ng/mL and the coefficient of variation was <10%. In addition, this method had no cross-reaction with other related mycotoxins. This optimized method for extracting T-2 from food and feed samples achieved a recovery rate of approximately 90% in T-2 concentrations as low as 1 ng/mL, better than the performance of a commercial ELISA kit. This competitive AlphaLISA method offers high sensitivity, good specificity, good repeatability and simple operation for detecting T-2 toxin in food and feed.

Assessment of Activity-Specific Metabolism of Aquatic Organisms: An Improved System

1992 ◽  
Vol 49 (6) ◽  
pp. 1142-1148 ◽  
Author(s):  
Ronald W. Davies ◽  
Frederick J. Wrona ◽  
V. Kalarani
Keyword(s):  
Oxygen Consumption ◽  
Individual Variation ◽  
Aquatic Organisms ◽  
Size Classes ◽  
Interspecific Differences ◽  
Nephelopsis Obscura ◽  
Highly Sensitive ◽  
Similar Weight ◽  
Flow Through

An improved flow-through respirometer capable of assessing activity-specific metabolism of aquatic organisms is presented and assessed. The system is highly sensitive and versatile, since it continuously monitors and records activity-specific oxygen consumption readings for periods up to 72 h and is capable of detecting differences in metabolism of individual specimens of similar weight. Using this system, we demonstrated individual variation and intraspecific differences in metabolism between two size classes of the freshwater leech Nephelopsis obscura and interspecific differences between N. obscura and another freshwater leech, Erpobdella montezuma, and compared these findings with the metabolism of the amphipod Hyalella montezuma.

scholarly journals A mixture of β-glucan and mannanoligosaccharide ameliorated the growth rate, digestive enzyme activity, intestinal morphometry, and immunity of common carp (Cyprinus carpio)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fawzy I. Magouz ◽  
Mahmoud F.I. Salem ◽  
Aliaa E.I. Emara ◽  
Mohamed M. Hassan ◽  
Mahmoud A.O. Dawood
Keyword(s):  
Growth Rate ◽  
Common Carp ◽  
Digestive Enzyme ◽  
White Blood Cells ◽  
Aquatic Organisms ◽  
Basal Diet ◽  
Control Group ◽  
Feed Conversion ◽  
Final Weight ◽  
Intestinal Morphometry

Abstract The feasible strategies to keep up the growth and wellbeing of aquatic organisms by using beneficial dietary additives is highly recommended. Among these additives, β-glucan (BG) and mannanoligosaccharide (MOS) were examined on common carp performances in the current experiment. For 80 days, carps fed four diets with 0%, 1%, 2%, and 3% BG/MOS (1:1) and distributed in four groups (triplicates). Higher final weight and weight gain (P < 0.05) were detected in carps fed 1%, 2%, and 3% of BG/MOS than the control group. The feed conversion ratio showed lower values (P < 0.05) in carps-fed BG/MOS mixture at 2%, and 3% than 0% and 1% levels. The activities of amylase, lipase, and protease were higher in fish fed BG/MOS mixture than the control group. Interestingly, fish fed BG/MOS mixture had markedly increased villi length and width with branched villi integrity. Further, the count of goblet cells was increased (P < 0.05) in groups fed BG/MOS mixture than carps fed the basal diet. The hemoglobin and hematocrit levels and the counts of red and white blood cells were higher in carps fed BG/MOS mixture than the control with the highest counts in 3% level. Additionally, the blood total protein, globulin, and phagocytic activity were higher (P < 0.05) in groups received BG/MOS mixture at 3% than the control. The lysozyme had a higher value in 1% group than the control (P < 0.05). Therefore, using the mixture of BG/MOS at 2-3% is suggested for improving the growth rate, intestinal health, blood health, and immunity of common carp.

scholarly journals A multi-center clinical study comparing Sansure Magb and CAP/CTM HBV tests in the quantitative detection of HBV DNA

2016 ◽  
Vol 10 (07) ◽  
pp. 755-761 ◽  
Author(s):  
Xiaoyu Fu ◽  
Deming Tan ◽  
Xiaoguang Dou ◽  
Jinjun Chen ◽  
Juan Wu
Keyword(s):  
Developing Countries ◽  
Accurate Method ◽  
Magnetic Bead ◽  
Hbv Dna ◽  
Quantitative Detection ◽  
Plot Analysis ◽  
Highly Sensitive ◽  
Data Points ◽  
Quantitative Results ◽  
Chinese Company

Introduction: As the most reliable means of diagnosing hepatitis (HBV) infection and predicting the prognosis of HBV-related chronic liver disease, the COBAS AmpliPrep/COBAS TaqMan real-time polymerase chain reaction (PCR) (CAP/CTM) assay provides a highly sensitive and accurate method for quantifying HBV DNA. However, the high cost of the COBAS reagents is prohibitive in many developing countries. Thus, we compared the Sansure magnetic bead (Magb) assay, a novel technology developed by a Chinese company, with the CAP/CTM assay. Methodology: The reproducibility and sensitivity of the Sansure Magb assay were first validated using HBV DNA reference samples. Next, the quantitative results for the two assays using 635 blood samples collected from chronic hepatitis B patients and 10 healthy controls were compared. Results: The Sansure Magb assay showed high reproducibility and was at least as sensitive and specific as the CAP/CTM assay. Among the patient samples, 407 tested positive by both methods, with 386 (94.84%) showing quantitative differences of less than 1 log unit and 21 (5.16%) showing quantitative differences of between 1 and 2 log units. The results from the assays were closely correlated. Bland-Altman plot analysis showed that only 6.6% of the data points fell outside the 95% limits of agreement, which suggests that the differences between methods are clinically acceptable. Conclusions: This study demonstrates that the Sansure Magb assay is highly sensitive and reproducible. Based on its reduced cost, the Sansure Magb assay may be more applicable than the CAP/CTM assay for HBV diagnosis in developing countries such as China.

scholarly journals Segments of cognitive responses towards local food safety concerns amongst international students in Ghana

2021 ◽  
Vol 3 (1) ◽  
pp. 20-43
Author(s):  
Abednego Kofi Bansah ◽  
Issahaku Adam ◽  
Stephen Edem Hiamey
Keyword(s):  
International Students ◽  
Food Safety ◽  
Local Food ◽  
Cognitive Responses ◽  
Local Foods ◽  
Safety Concerns ◽  
Safety Regulations ◽  
Safety Research ◽  
Highly Sensitive ◽  
Clustering Approach

Despite the attention paid to food safety research, few empirical works have used a non-reductionist perspective to understand how  international consumers cognitively respond to local food safety conditions. Using the tri-component theorisation and the two-step clustering approach with the Kruskal Wallis test on a sample of 109 international students in Ghana, this study provides a non-reductionist cognitive segment of international students towards local food safety conditions in Ghana. The findings revealed that there are three cognitive segments of international consumers towards local food safety conditions, namely self-regards, pessimists, and epicureans. Self-assureds respond to their own self-cognition towards local food safety concerns but deny the cognition of others, moderately respond affectively and sometimes avoid local foods. Pessimists have a highly sensitive cognitive response towards local food safety conditions, high affective responses and avoid the consumption of local foods as a result, while epicureans do not cognitively respond to local food safety conditions, have low affective reactions and consume local foods regardless of the food safety conditions. The implications of these findings in the context of local food preparation, packaging, and handling as well as food safety regulations and marketing are discussed

Effects of endocrine active substances in wildlife species: Genetic, biochemical, and physiological factors in variable susceptibility to endocrine disruptors

2003 ◽  
Vol 75 (11-12) ◽  
pp. 2335-2341 ◽  
Author(s):  
Shin'ichiro Kawai ◽  
M. Kobayashi ◽  
Hideo Kaneko
Keyword(s):  
Endocrine System ◽  
Aquatic Organisms ◽  
Xenobiotic Metabolism ◽  
Environmental Chemicals ◽  
Ah Receptor ◽  
Blood Levels ◽  
Aromatase Activity ◽  
Physiological Factors ◽  
Wildlife Species ◽  
Active Substances

Responses to endocrine active substances (EASs) in animals are various, and differences between the responses among individuals, populations and species are well known. These differences are observed not only in EASs but in most environmental chemicals including synthetic and naturally occurring ones. The basic differences in sensitivity to EASs are attributed to that of affinity or specificity of the receptors to EASs at the cellular level. Although the nucleotide sequences encoding for estrogen receptor proteins have been documented in several species and the functions of the receptors are the same, the ability to bind the natural hormones and the estrogenic xenobiotics is not necessarily identical. The reproductive endocrine system is basically common among vertebrates, but chemical types of hormones, physiological roles of hormones and the basal blood levels of hormones differ among each species, especially in sex steroids. These differences cause various types of responses and sensitivity to EASs among animal species. Xenobiotic metabolism is important for the genetical, biochemical and physiological factors concerning the influence of EASs. Some EASs directly inhibit cytochrome P450 (CYP) activity as was reported in tributyltin that inhibits CYP19 (aromatase) activity causing imposex in neogastropods. Some organochlorines including dioxins stimulate aryl hydrocarbon (Ah) receptor-mediated xenobiotic metabolism, and result in the metabolic disruption of steroid hormones such as estrogen as were reported in eggshell thinning in birds of prey and uterus occlusion in seals. CYP activity greatly differs among wildlife species in both terrestrial and aquatic organisms, and these differences are significantly responsible for the multiple effects or toxicity of EASs. Sex and age differences also cause different responses to EASs and are largely due to the differences in xenobiotic metabolizing activities.

scholarly journals Periphyton Technology Enhances Growth Performance and Delays Prolific Breeding of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758), Juveniles

2021 ◽  
Vol 34 (4) ◽  
Author(s):  
MAVINDU MUTHOKA ◽  
◽  
ERICK OCHIENG OGELLO ◽  
HENRY OUMA ◽  
KEVIN OBIERO
Keyword(s):  
Growth Performance ◽  
Survival Data ◽  
Oreochromis Niloticus ◽  
Crude Protein ◽  
Chicken Manure ◽  
Feed Conversion ◽  
Growth And Survival ◽  
Commercial Diet ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Synthetic Hormones

This study evaluated the effect of periphyton technology (PPT) on the growth performance and breeding schedule of Oreochromis niloticus (Linnaeus, 1758) juveniles. Six ponds, each measuring 81 m2 were used for the study. The ponds were applied with agricultural lime at a rate of 4 g.m-2, and fertilised using chicken manure to facilitate primary productivity. The PPT ponds were fitted with two-metre-long eucalyptus poles of 5 cm diameter placed at 50 cm intervals with the regular addition of molasses as a carbon source. Tilapia juveniles were stocked at a density of 3 fish.m-2 in all ponds and fed on a commercial diet of 20 % crude protein (CP) twice daily at 3 % body weight. Fish were sampled weekly for growth and survival data and bi-weekly for fecundity estimates. The PPT-ponds registered significantly higher survival rate (97.50 ± 0.35 %), mean weight (150.69 ± 0.99 g), specific growth rate (SGR) (2.75 ± 0.01), and feed conversion ratio (FCR) (1.29 ± 0.01), than the control ponds, which registered survival (91.15 ± 0.88 %), mean weight (99.23 ± 0.96 g), SGR (2.29 ± 0.00), and FCR (1.58 ± 0.01). There was significantly higher fecundity in the PPT-ponds (2.28 ± 0.09 g.fish-1) than control (1.74 ± 0.06 g.fish-1), with prolific spawning starting 4 weeks earlier in the control ponds than in the PPT-ponds. This study demonstrated the potential of PPT for enhancing tilapia growth while delaying prolific breeding behaviour. Further studies should explore PPT in replacing synthetic hormones for sex-reversal of tilapia fry in hatcheries.

scholarly journals Neglect of Temperature and pH Impact Leads to Underestimation of Seasonal Ecological Risk of Ammonia in Chinese Surface Freshwaters

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Zhen-Guang Yan ◽  
Jun-Tao Fan ◽  
Xin Zheng ◽  
Shu-Ping Wang ◽  
Xiao-Shan Guo ◽  
...  
Keyword(s):  
Water Quality ◽  
Ecological Risk ◽  
Quality Criteria ◽  
Aquatic Organisms ◽  
Ammonia Nitrogen ◽  
Water Quality Criteria ◽  
Water Parameters ◽  
Highly Sensitive ◽  
Ph Impact ◽  
Ecological Risk Assessments

Ammonia nitrogen (AN) is evaluated with fixed water quality standards (WQSs) in aquatic environment management in China. Since the toxicity of AN can be influenced by water parameters, the current evaluation is not rigorous and may result in problematic conclusions. The present study collected the ecotoxicity and exposure data of AN in Chinese surface freshwaters in 2017. The species sensitivity distribution of AN was established, and the ecological risk posed by AN in Chinese surface waters was assessed with Chinese AN water quality criteria. The results showed that mollusk species are the most sensitive taxa to AN. Ecological risk assessments on AN suggested that, in summer and autumn, when the water temperature and pH are high, the risk of AN may occur at some sites with good water quality (Class II or III). This poses a threat to aquatic organisms at these sites, especially highly sensitive freshwater shellfish. It suggested that neglect of water parameters impact may lead to underestimation of ecological risk of AN in Chinese basins.

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