Determination of Veterinary Drug Residues in Animal-derived Foods by Liquid Chromatography-Mass Spectrometry

[Objectives]This study was conducted to establish a rapid and effective method for simultaneous extraction of 54 kinds of veterinary drug residues in animal-derived food, including sulfonamides, quinolones, tetracyclines, malachite greens, penicillins, nitroimidazoles, tranquilizers and macrolides, by HPLC-MS. [Methods] The samples were extracted with 80% acetonitrile water(containing 0.1% formic acid), combined with QuEChERS extraction technology and C18 and PSA purification, analyzed by high performance liquid chromatography-mass spectrometry, and quantified by external standard method. The target substances were analyzed on ZORBAX Eclipse C18 chromatographic column using 0.2% formic acid water and 0.2% methanol as mobile phases. The gradient elution mode was used for chromatographic separation and multiple reaction detection. [Results] In the linear range of 0.5-50.0 ng/ml, the linear relationship of the 54 kinds of veterinary drug residues was good, with correlation coefficients(r~2) greater than 0.995, and the detection limits ranged from 0.30 to 1.00 μg/kg. The results showed that the recovery ranged from 75.4% to 118.2% when different matrixes were added for recovery. [Conclusions] This method is simple, efficient, accurate, stable, and highly operable. It is applicable to simultaneous batch screening of veterinary drug residues in animal-derived food, and has high practical application value.

Extrahepatic bile duct reconstruction in pigs with heterogenous animal-derived artificial bile ducts:A preliminary experience

BACKGROUND Extrahepatic biliary duct injury(BDI)remains a complicated issue for surgeons.Although several approaches have been explored to address this problem,the high incidence of complications affects postoperative recovery.As a nonimmunogenic scaffold,an animal-derived artificial bile duct(ada-BD)could replace the defect,providing good physiological conditions for the regeneration of autologous bile duct structures without changing the original anatomical and physiologic conditions.AIM To evaluate the long-term feasibility of a novel heterogenous ada-BD for treating extrahepatic BDI in pigs.METHODS Eight pigs were randomly divided into two groups in the study.The animal injury model was developed with an approximately 2 cm segmental defect of various parts of the common bile duct(CBD)for all pigs.A 2 cm long novel heterogenous animal-derived bile duct was used to repair this segmental defect(group A,ada-BD-to-duodenum anastomosis to repair the distal CBD defect;group B,ada-BD-to-CBD anastomosis to repair the intermedial CBD defect).The endpoint for observation was 6 mo(group A)and 12 mo(group B)after the operation.Liver function was regularly tested.Animals were euthanized at the above endpoints.Histological analysis was carried out to assess the efficacy of the repair.RESULTS The median operative time was 2.45 h(2-3 h),with a median anastomosis time of 60.5 min(55-73 min).All experimental animals survived until the endpoints for observation.The liver function was almost regular.Histologic analysis indicated a marked biliary epithelial layer covering the neo-bile duct and regeneration of the submucosal connective tissue and smooth muscle without significant signs of immune rejection.In comparison,the submucosal connective tissue was more regular and thicker in group B than in group A,and there was superior integrity of the regeneration of the biliary epithelial layer.Despite the advantages of the regeneration of the bile duct smooth muscle observed in group A,the effect on the patency of the ada-BD grafts in group B was not confirmed by macroscopic assessment and cholangiography.CONCLUSION This approach appears to be feasible for repairing a CBD defect with an ada-BD.A large sample study is needed to confirm the durability and safety of these preliminary results.

Determination of Sodium Pentachlorophenoxide Residues in Animal-derived Foods by Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS)

[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The samples were extracted with an acetonitrile water solution(8∶2),0.1 mol/L hydrochloric acid and a purification extraction bag with shaking.Centrifugation was performed to obtain supernatants,which were added to purification tubes containing PSA and C_(18) for purification,and then filtered with membranes for determination.Each test solution was separated by a ZORBAX Eclipse plus C_(18) column with acetonitrile and 5 mmol/L ammonium acetate as mobile phases,and determined with electrospray ionization and multiple reaction monitoring.[Results]The method had good linearity in the concentration range of 1.0-50 ng/ml,and the correlation coefficient was 0.9997.The limit of detection was 0.25μg/kg and the limit of quantification was 0.75μg/kg.The recovery was between 87.4%and 112.5%,and the RSD%was between 0.5%and 10.0%.[Conclusions]The method has simple operation and high sensitivity,and is suitable for trace detection of sodium pentachlorophenoxide in large quantities of animal-derived food.

Impact of China’s sanitary and phytosanitary measures on animal-derived food imports

This paper takes the imports of animal-derived food as the example,and uses the 6-digit-code HS data of the CEPII BACI database ranging from 2002 to 2018 in an extended gravity model to study the impact of the sanitary and phytosanitary(SPS)measures implemented in China on the import trade and trade margins of animal-derived food.The results show that(1)China’s SPS measures have not significantly restricted the import trade of animal-derived food but rather enhanced import trade by alleviating negative externalities and information asymmetry;(2)SPS measures have positive effects on the extensive,price,and quantity margins for developed countries;while(3)SPS measures have negative effects on the quantity margin for developing countries.Thus,China’s SPS measures have not yet constituted a trade restriction.

Determination of Sym-triazine Residues in Animal-derived Food by Liquid Chromatography-High Resolution Mass Spectrometry

[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L（r^2〉0.99）.The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations（RSD）were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.

Preclinical testing of immunotoxicity for animal-derived dermal materials

Animal derived materials have been widely used in biomedical products owing to their good biocompatibility and appropriate mechanical properties.It is crucial to evaluate the immunotoxicity of such materials in preclinical testing to prevent severe immune responses in patients.In this study,a pipeline of immunotoxicity tests was established to evaluate animal-derived materials before de-cellularization and final products.This pipeline contains a serial of animal tests on BALB/c mice and an in vitro quantification test for a-Gal antigen.It is wellrecognized that the interaction between materials and patients profoundly alters immune responses,thus,a comprehensive dataset including body weight,immune organ coefficient,histopathology,peripheral hematology,serum immunoglobulin level,spleen lymphocyte proliferation rate,and their subpopulation was created and analyzed using the SPSS tool.These results clearly suggested that the de-cellularized materials possessed better biocompatibility,in addition,the a-Gal antigen content was effectively decreased by 96.0%after decellularization.Thus,this study confirmed that this multi-step enzymatic de-cellularization treatment is a potent method to reduce the immunotoxicity of animal-derived biomaterials.Moreover,the experimental pipeline will likely be transferable to other biomedical materials and products.

Bibliometric analysis of the literature from the mainland of China on animal-derived regenerative implantable medical devices

Choosing animal-derived regenerative implantable medical devices based on tissue engineering technology as a research theme, this paper presents bibliometric analysis of relative literature from the mainland of China to understand such data as publication year and journal preference, authors＇ geographic location, research topics and core expertise to predict the research trends and provide an informed basis of decision making for researchers and clinicians.

In vitro genotoxicity evaluation and metabolic study of residual glutaraldehyde in animal-derived biomaterials

Glutaraldehyde(GA)is an important additive that is mainly used in animal-derived biomaterials to improve their mechanical and antimicrobial capacities.However,GA chemical toxicity and the metabolic mechanism remain relatively unknown.Therefore,residual GA has always been a major health risk consideration for animal-derived medical devices.In this study,extracts of three biopatches were tested via the GA determination test and mouse lymphoma assay(MLA).The results showed that dissolved GA was a potential mutagen,which could induce significant cytotoxic and mutagenic effects in mouse lymphoma cells.These toxic reactions were relieved by the S9 metabolic activation(MA)system.Furthermore,we confirmed that GA concentration decreased and glutaric acid was generated during the catalytic process.We revealed GA could be oxidized via cytochrome P450 which was the main metabolic factor of S9.We found that even though GA was possibly responsible for positive reactions of animal-derived biomaterials’biocompatibility evaluation,it may not represent the real situation occurring in human bodies,owing to the presence of various detoxification mechanisms including the S9 system.Overall,in order to achieve a general balance between risk management and practical application,rational decisions based on comprehensive analyses must be considered.

Current trends in nanomaterials-mediated biosensing platforms and signal amplification strategies for antibiotics detection in dairy products

Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.

Analysis of intellectual properties on animalderived regenerative, implantable medical devices

This article analyses and summarizes issues of intellectual property involved in animal-derived regenerative,implantable medical devices(ADRIMD)in order to better understand global trends in patent applications and disclosures,the legal status of patent families(i.e.sets of patents filed in various countries to protect a single invention),and International Patent Classification topics such as main assignee and core expertise.Analysis of research trends will enhance and inform the decision-making capacity of researchers,investors,government regulators and other stake-holders as they undertake to develop,deploy,invest in or regulate ADRIMD.