Bovine Kidney Tissue Research Articles

Comparison of filter membranes in the analysis of 183 veterinary and other drugs by liquid chromatography-tandem mass spectrometry.

Although filtration is one of the most common steps in sample preparation for chemical analysis, filter membrane materials can leach contaminants and/or retain some analytes in the filtered solutions. In multiclass, multiresidue analysis of veterinary drugs, it is challenging to find one type of filter membrane that does not retain at least some of the analytes before injection in ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In this study, different filter membranes were tested for use in UHPLC-MS/MS analysis of 183 diverse drugs in bovine muscle, kidney, and liver tissues. Membranes evaluated consisted of polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVDF), polyethersulfone, nylon, and regenerated cellulose. Drug classes represented among the analytes included β-agonists, β-lactams, anthelmintics, macrolides, tetracyclines, sulfonamides, tranquilizers, (fluoro)quinolones, anti-inflammatories, nitroimidazoles, coccidiostats, phenicols, and others. Although the presence of a matrix helped reduce the binding of analytes on surface active sites, all of the filter types partially retained at least some of the drugs in the final extracts. In testing by flow-injection analysis, all of the membrane filters were also observed to leach interfering components. Ultimately, filtration was avoided altogether in the final sample preparation approach known as the quick, easy, cheap, effective, rugged, safe, efficient, and robust (QuEChERSER) mega-method, and ultracentrifugation was chosen as an alternative.

Measurement of Thermal Conductivity and Thermal Diffusivity of Porcine and Bovine Kidney Tissues at Supraphysiological Temperatures up to 93 °C.

This experimental study aimed to characterize the thermal properties of ex vivo porcine and bovine kidney tissues in steady-state heat transfer conditions in a wider thermal interval (23.2-92.8 °C) compared to previous investigations limited to 45 °C. Thermal properties, namely thermal conductivity (k) and thermal diffusivity (α), were measured in a temperature-controlled environment using a dual-needle probe connected to a commercial thermal property analyzer, using the transient hot-wire technique. The estimation of measurement uncertainty was performed along with the assessment of regression models describing the trend of measured quantities as a function of temperature to be used in simulations involving heat transfer in kidney tissue. A direct comparison of the thermal properties of the same tissue from two different species, i.e., porcine and bovine kidney tissues, with the same experimental transient hot-wire technique, was conducted to provide indications on the possible inter-species variabilities of k and α at different selected temperatures. Exponential fitting curves were selected to interpolate the measured values for both porcine and bovine kidney tissues, for both k and α. The results show that the k and α values of the tissues remained rather constant from room temperature up to the onset of water evaporation, and a more marked increase was observed afterward. Indeed, at the highest investigated temperatures, i.e., 90.0-92.8 °C, the average k values were subject to 1.2- and 1.3-fold increases, compared to their nominal values at room temperature, in porcine and bovine kidney tissue, respectively. Moreover, at 90.0-92.8 °C, 1.4- and 1.2-fold increases in the average values of α, compared to baseline values, were observed for porcine and bovine kidney tissue, respectively. No statistically significant differences were found between the thermal properties of porcine and bovine kidney tissues at the same selected tissue temperatures despite their anatomical and structural differences. The provided quantitative values and best-fit regression models can be used to enhance the accuracy of the prediction capability of numerical models of thermal therapies. Furthermore, this study may provide insights into the refinement of protocols for the realization of tissue-mimicking phantoms and the choice of tissue models for bioheat transfer studies in experimental laboratories.

Identification and characterisation of lumpy skin disease virus recently isolated from Giza, Egypt

Lumpy skin disease (LSD) is a viral disease, geographically distributed in Africa and now, vigorously spread in the Near East and also in Europe and Asia. It has a significant economic impact on cattle industry in Africa. The aim of this study was isolation and rapid identification of LSD virus circula­ting in Egypt from clinically suspected cattle based on clinical and molecular basis in a rapid and accurate way. Fifteen representative specimens (skin sitfasts) were collected in 2018 from clinically infected cattle in Giza governorate, Egypt. The virus was isolated on chorioallantoic membrane of specific pathogen free embryonated chicken eggs and Madin Darby Bovine Kidney tissue culture cells. The isolated virus was identified and confirmed by conventional polymerase chain reaction (PCR) and real-time PCR. Histopathological examination of the lesions showed a pathognomic intracytoplasmic inclusion body in dermal stroma section. The section of dermal layer revealed vasculitis with projection of its endothelial lining. It was concluded that LSD was enzootic in Egypt and still circulating among Egyptian cattle so that LSD virus could be isolated and identified by traditional and molecular diagnostic methodes. Real time PCR assay could be applied for rapid and accurate confirmation of the field isolate of LSD virus.

A SNP of the COX4I2 gene associated with environmental adaptation in Chinese cattle

COX4I2 is an isoform of cytochrome C oxidase subunit IV (COX4), which plays an important role in mitochondrial oxidative phosphorylation. This gene affects heat production and thus affects thermoregulatory capacity in mammals. A splice region variant (rs109072064, NC_037340.1:g.61202988C > T) was identified in COX4I2 by using Ensembl, which transforms the amino acid arginine into cysteine in XP_005214921.1. In this study, we sought to determine the relationship between the mutant locus and the environment in which the cattle are located. We verified that mRNA (XM_005214864.4), which translated XP_005214921.1, is expressed in bovine muscle, fat, heart, liver, kidney, lung and testis tissues. The g.61202988C > T variant was then genotyped in 569 individuals of 34 cattle breeds. Compared with the CC genotype, southern cattle carried more the CT and TT genotypes. Furthermore, the association results carried out that the frequencies of genotypes (CC, CT, TT) and the value of climate parameters (mean annual temperature (T), relative humidity (RH) and temperature humidity index (THI)) were significantly correlated (P < 0.01). Hence, we speculated that the g.61202988C > T variant of COX4I2 gene was associated with the environmental adaptation trait in Chinese cattle and the locus may be considered as a molecular marker for Chinese cattle breeding.

The bovine Prader-Willi/Angelman imprinted domain has four Sno-lncRNAs types.

Sno-lncRNAs are intron-derived long noncoding RNAs (lncRNAs) with snoRNA ends. Sno-lncRNAs were first discovered in the human Prader-Willi (PWS)/Angelman (AS) imprinted domain. Here, we report the identification and characterization of four sno-lncRNA types (sno-lncRNA1, sno-lncRNA2, sno-lncRNA3, and sno-lncRNA4) in the bovine PWS/AS imprinted domain. Reverse transcription-PCR first determined the cDNA sequences of the four bovine sno-lncRNAs. A gene structure analysis showed that sno-lncRNA1 lacks introns, but sno-lncRNA2 and sno-lncRNA3 have one and two introns respectively. The three sno-lncRNAs have similar snoRNA ends. Moreover, the three have similar snoRNAs at their 5' and 3' ends. The head-to-tail orientation has six sno-lncRNA copies arranged between bovine SNORD116-6 and SNORD116-12. Moreover, only a copy of sno-lncRNA4 was located between SNORD116-3 and SNORD116-4. The expression of the four sno-lncRNAs was analyzed in the bovine heart, liver, spleen, lung, kidney, muscle, fat, brain, and placenta tissues. The monoallelic expression of sno-lncRNA4 was determined in bovine tissues. The results showed that the four sno-lncRNAs are widely expressed in the nine tissues, although sno-lncRNA3 and sno-lncRNA4 were undetected in the placenta. Moreover, an informative single nucleotide polymorphism (rs448706424) revealed the allelic expression of sno-lncRNA4 in exon 2 of sno-lncRNA4. The bovine genome had six copies of sno-lncRNA1, sno-lncRNA2, and sno-lncRNA3, but their allelic expression was not identified.

Oxytetracycline residues in bovine muscles, liver and kidney tissues from selected slaughter facilities in South Western Uganda

BackgroundDue to high disease burden and poor animal health services in Uganda, administration of antimicrobials particularly oxytetracycline (OTC) is often done by farm owners and workers without any prescription. This results in misuse of OTC with consequent high chances of antibiotic residues and antimicrobial resistance hence posing public health threat. The degree of public health threat from OTC use is not well established due to limited published data on antibiotic residues and usage in livestock production in Uganda. This study comparatively determined OTC residue levels in 318 samples of bovine muscles, liver and kidney tissues from Kiruhura, Mbarara and Ntungamo districts of South Western Uganda during dry and wet seasons.ResultsThe results revealed that the overall OTC residues positivity levels was 74.84% while the district wise rates were 56.88%, 84% and 84.52% for Kiruhura, Mbarara and Ntungamo, respectively. The mean OTC residue levels in bovine muscles, liver and kidney tissues were above the recommended maximum residue limits of 200, 600 and 1200 µg/kg, respectively as established by FAO/WHO. Of the collected samples, 72.41% (236/318) had OTC residues in concentrations above the recommended maximum residue limits. Wilcoxon signed rank test results showed that change in the seasons did not cause any significant changes in the liver OTC residue levels for all the districts, though this was significant for muscles from Kiruhura and Mbarara districts. Unacceptably high OTC levels were found in the muscles, liver and some kidney samples: Kiruhura muscles and liver samples had mean OTC concentrations of 1094 ± 378 µg/kg and 967 ± 198 µg/kg; Mbarara muscles, liver and kidney samples had mean OTC mean concentrations of 668 ± 163 µg/kg, 3778 ± 1140 µg/kg and 12,576 ± 1630 µg/kg, respectively while Ntungamo samples had mean OTC concentrations of 586 ± 123 µg/kg and 5194 ± 1463 µg/kg in muscle and liver tissues.ConclusionsThe results of this study indicated that there are unacceptably high OTC residue levels in bovine tissues consumed in South Western Uganda. This poses a public and veterinary health threat to consumers of these bovine tissues.

Investigation of Beta-Lactam and Tetracycline Group Antibiotic Residues in Bovine Liver, Kidney and Muscle Tissue

In this study, beta-lactam and tetracycline antibiotic residues were investigated in cattle liver, kidney and muscle samples. For this purpose, a total of 75 bovine tissue samples (each of 25 from liver, kidney, muscle) taken from 25 cattle slaughtered in a local slaughterhouse in Sivas were used as materials. ELISA method was applied in the analysis and it was studied with commercial test kits. According to the results of the analysis; beta-lactam and tetracycline residues were detected in all bovine tissue samples. Beta-lactam level was determined between 0.75-1.07 ppb (mean 0.94 ± 0.01) in liver samples, 0.67-1.05 ppb (mean 0.81 ± 0.01) in kidney samples and 0.70-2.57 ppb (mean 0.97 ± 0.07) in muscle samples. Tetracycline level was detected in the range of 4.48-8.50 ppb (mean 6.14 ± 0.17) in liver samples, 1.73-6.39 ppb (mean 4.90 ± 0.24) in kidney samples and 3.31-7.45 ppb (mean 5.67 ± 0.25) in muscle samples. The residue levels determined in the examples complied with the legal limits reported in the European Commission and the Turkish Food Codex Communiqué.

Genomic imprinting of the IGF2R/AIR locus is conserved between bovines and mice

Genomic imprinting is an epigenetic phenomenon that leads to genes monoallelically expressed in a parent-of-origin-specific manner and plays an important role in the embryonic development and postnatal growth of mammals. Imprinted genes usually occur in clusters in a chromosomal region and are regulated by a cis-acting imprinting control region that involves differential DNA methylation modification. Igf2r, Slc22a2 and Slc22a3 are three maternally expressed genes on mouse chromosome 17. The paternally expressed long noncoding RNA (lncRNA) Air and the nonimprinted gene Slc22a1 are also located in the imprinted region. Comparative characterization of imprinted clusters between species is useful for us to understand the biological significance and epigenetic regulating mechanism of genomic imprinting. The aim of this study was to analyze the allelic expression pattern of AIR and SLC22A1-3 genes in cattle and to determine the role of DNA methylation in regulating gene expression. Allelic expression analysis was performed in bovine adult tissues and term placenta using an SNP-based approach. We found that IGF2R, AIR and SLC22A3 were monoallelically expressed in all detected bovine somatic tissues, including heart, liver, spleen, lung, kidney, muscle, fat and brain. In bovine placenta, IGF2R and SLC22A3 are maternally expressed; however, the AIR gene is paternally expressed. Tissue-specific monoallelic expression of SLC22A2 is detected in bovines, with monoallelic expression in the spleen and brain but biallelic expression in kidney tissues. SLC22A1 is only detected in bovine liver and kidney tissues and is biallelicly expressed, which is consistent with the imprint expression in mice. To determine the possible role of DNA methylation in regulating the monoallelic/imprinted expression of bovine IGF2R, AIR, SLC22A2, and SLC22A3 genes, we analyzed the DNA methylation status of CpG islands in the first exon of SLC22A2, the promoter region of SLC22A3 and region 2 in the second intron of the IGF2R gene by bisulfite sequencing. Two differentially methylated regions (DMRs) were detected in the first exon of bovine SLC22A3 and the common regions of IGF2R and AIR. This suggests that DNA methylation is involved in the regulation of monoallelic/imprinted expression of IGF2R, AIR and SLC22A3 genes in cattle.

Effect of composite coating on insertion mechanics of needle structure in soft materials

This research aims to study the effect of a composite coating comprised of polydopamine (PDA), polytetrafluoroethylene (PTFE), and activated Carbon on the insertion mechanics of surgical needles in tissues i.e., polyvinyl chloride (PVC) tissue phantom and bovine kidney. A needle insertion and extraction test system was designed and constructed to measure the insertion and extraction forces. It was found that the composite coating on the needle surface decreases the maximum average insertion and extraction forces by 62% and 64%, respectively, when tested in PVC tissue phantom and by 49% and 30%, respectively, in bovine kidney tissue. Additionally, an Atomic Force Microscope study was performed to characterize the surface properties of the coated needles. It was found that the composite coating reduced the friction force on the needle surface by 65.7%. The decrease in these forces is critical in minimizing tissue damage and decreasing needle path deviation or deflection during percutaneous procedures.

Molecular differentiation between field lumpy skin disease isolate and Capripoxvirus vaccinal strains in Egypt 2018

Lumpy skin disease virus is a member of the Capripoxvirus genus of the Poxviridae family, which affects cattle and causes a notifiable disease with significant economic losses. It is controlled by vaccination with capripox live attenuated vaccines. The aim of the study was the isolation and identification of the lumpy skin virus field virus strain during 2018. Nodular skin lesions were collected from clinically infected lumpy skin disease cattle that were used for the virus isolation on the chorioallantoic membrane of specific pathogen free embryonated chicken eggs and Madin Darby Bovine Kidney tissue culture. Polymerase chain reaction targeting the Capripoxvirus CaPV ORF103 gene was applied on the isolated virus and three Capripoxvirus vaccinal strains (Kenyan sheep pox virus, Held goat pox virus and Ismailia lumpy skin disease virus). The amplicons of the four strains of Capripoxvirus (one isolated and three vaccinal strains) were used for sequencing. Reference capripox viruses were obtained from GenBank to create the phylogenetic tree. The virus isolated from the collected nodular skin samples on chicken eggs showed clear typical pock lesions on the chorioallantoic membrane and on tissue cultures and showed a characteristic cytopathic effect. Positive samples of the isolated strain were identified by PCR for the CaPV ORF103 gene that yielded expected amplicon sizes of 570 bp. This was confirmed through gene sequence and analysed by BLAST, and submitted to GenBank under accession number MW 546997_LSD_Aziz_LSD. The phylogenetic tree revealed that the field isolate strain of LSDV had different identity percentages ranging from 98.2–99.8% with the tested vaccinal Capripoxvirus strains in Egypt. The amino acid sequence showed only different amino acid found in the field isolate strain and not in other tested vaccinal strains, and a maximum homology (100%) of the isolated strain nucleotide sequence was with two GenBank recorded strains. We recommend maintaining the routine lumpy skin disease vaccination programme in Egypt, frequent eradication of the insect population, and further genetic studies on the genomes of this virus strain and the Capripoxvirus vaccinal strains to reach the most related and homologous vaccinal strain given the massive genome of this disease.

Incidence of lumpy skin disease virus with its characterization in vaccinated pregnant Holstein cows in Dakahlia governorate, Egypt

Lumpy skin disease (LSD) is an infectious economically important viral disease of cattle. Lumpy skin disease virus (LSDV) is still circulating in Egypt, despite the annual mass vaccination with sheep pox virus vaccine recommended by the Egyptian authorities. This study was carried out on two farms of pregnant Holstein cows vaccinated with Bovivax LSD-N® Vaccine (farm I) and Servac Capri-C vaccine® (farm II). After 40-60 days post-vaccination, mild clinical signs were detected in 3% of cows on the farm I whereas a more severe clinical infection was developed in 40% of cows on farm II. LSDV was isolated on the chorioallantoic membrane (CAM) of 11 days old embryonated chicken egg (ECEs) and Madin Darby bovine kidney (MDBK) tissue culture. LSDV was identified in collected skin tissues by Transmission electron microscopy (TEM) and histopathological examination. Finally, LSDV was confirmed by polymerase chain reaction (PCR) amplification at 192 base pair (bp) of the P32 gene and two samples were selected for DNA sequencing. LSDV developed characteristic pock lesions in inoculated ECEs. MDBK cell culture developed a prominent LSDV cytopathic effect at the 3rd passage. Viral particles were detected in the cytoplasm of both epidermal cells and dermal macrophages by TEM. Histopathological examination revealed different lesions correlated withLSDV infection age. LSDV was confirmed in all tested samples by PCR. Our strains (Dakahlia- 2020-1 and Dakahlia- 2020-2) were closely related to other Egyptian LSDV strains on GenBank with 98.2%-100% identity. The present study proved conclusive evidence that the live attenuated sheep poxvirus vaccine poorly protects Egyptian cattle against LSDV, while the LSDV Neethling strain vaccine gave a promising and sufficient protection rate

A Comparison of Gamma Irradiation Response Models of Bovine Blood, Liver and Kidney Tissues at Radiofrequency

This study is aimed at identifying gamma irradiated response of bovine blood, liver and kidney tissues at radiofrequency. For this purpose, impedence meter (Booton 7200) working in conjunction with signal generators (Loadster, SG416013 and Harris G857993) and improvised parallel plate dielectric cells constructed in line with the method of Laogun et al., (2005) were used to obtain the dielectric spread parameter gamma radiation α, of blood, liver and kidney tissues exposed to gamma irradiation dose range of 1.0 - 85.0 Gy. The dielectric spread parameter α gives the extent of damage induced in an irradiated tissue. Results of this work revealed that at 0 - 50 MHz frequency range, Kidney tissues displayed higher sensitive, followed Liver tissues and lasted the bovine blood between 0 - 60 Gy but reversed for blood and liver at 85 Gy. At 0 - 100 kHz frequency range liver tissue is more venerable to radiation injuries between gamma irradiation dose range of 0 - 20 Gy while between 43 - 85 Gy the Kidney’s sensitivity is the highest followed by blood and liver tissues. This implies that the liver tissues are less liable to radiation injuries at radiofrequency. A comparison of the linear, exponential and polynomial models using Akaike Information Criteria (AIC) revealed that linear models were the most suitable models for describing the effect of gamma radiation on the dielectric dispersion properties of bovine tissues at low and high radiofrequencies. This implies that the response of the investigated tissues increases linearly with gamma irradiation dose.

Simultaneous analysis of aminoglycosides with many other classes of drug residues in bovine tissues by ultrahigh-performance liquid chromatography-tandem mass spectrometry using an ion-pairing reagent added to final extracts.

The way to maximize scope of analysis, sample throughput, and laboratory efficiency in the monitoring of veterinary drug residues in food animals is to determine as many analytes as possible as fast as possible in as few methods as possible. Capital and overhead expenses are also reduced by using fewer instruments in the overall monitoring scheme. Traditionally, the highly polar aminoglycoside antibiotics require different chromatographic conditions from other classes of drugs, but in this work, we demonstrate that an ion-pairing reagent (sodium 1-heptanesulfonate) added to the combined final extracts from two sample preparation methods attains good separation of 174 targeted drugs, including 9 aminoglycosides, in the same 10.5-min ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The full method was validated in bovine kidney, liver, and muscle tissues according to US regulatory protocols, and 137-146 (79-84%) of the drugs gave between 70 and 120% average recoveries with ≤ 25% RSDs in the different types of tissues spiked at 0.5, 1, and 2 times the regulatory levels of interest (10-1000ng/g depending on the drug). This method increases sample throughput and the possible number of drugs monitored in the US National Residue Program, and requires only one UHPLC-MS/MS method and instrument for analysis rather than two by the previous scheme. Graphical abstract Outline of the streamlined approach to monitor 174 veterinary drugs, including aminoglycosides, in bovine tissues by combining two extracts of the same sample with an ion-pairing reagent for analysis by UHPLC-MS/MS.

A multi-residue method for 17 anticoccidial drugs and ractopamine in animal tissues by liquid chromatography-tandem mass spectrometry and time-of-flight mass spectrometry.

A new and sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QToF-MS) method was developed and validated for the determination and confirmation of residues of 17 anticoccidials, plus free ractopamine in poultry muscle and liver, and bovine muscle, liver, and kidney tissues. The 17 anticoccidials are lasalocid, halofuginone, narasin, monensin, semduramicin, ethopabate, robenidine, buquinolate, toltrazuril as its sulfone metabolite, maduramicin, salinomycin, diclazuril, amprolium, decoquinate, dinitolmide, clopidol, and the nicarbazin metabolite DNC (N,N1-bis(4-nitrophenyl)urea). The analytes were extracted and cleaned up within a 3-hour period by simply extracting the analytes into a solvent mixture with salts followed by centrifugation, dilution, and filtration. The validated method was used in a pilot study for the analysis of 173 samples that included quail liver, bovine kidney, liver, muscle, and horse muscle. The predominant residues found in this study were monensin, ractopamine, and lasalocid. The results of this pilot study showed that this new method is applicable to real samples, and is fit for use in a regulatory testing programme. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis. © 2016 John Wiley & Sons, Ltd.

Optimization and validation method to evaluate the residues of β-lactams and tetracyclines in kidney tissue by UPLC–MS/MS

Methods are validated by a process that defines the analytical requirements and confirms that the investigated method is capable of performing consistently. A quantitative and confirmatory method for determining the presence of β-lactam and tetracycline multiresidues in avian, bovine, equine, and swine kidney tissues using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed, optimized, and validated. Analytes were extracted from the kidneys by a mixture of water and acetonitrile, and the extract was then purified with hexane and C18 (dispersive phase). The method was evaluated by the following parameters: linearity, matrix effect, specificity, decision limits (CCα), detection capability (CCβ), accuracy, precision, trueness, limits of detection (LOD), limits of quantification (LOQ), and robustness. The validated method presented a broad linear study range and significant matrix effect. The limit of detection (LOD) was defined from 2.5 to 25.0µgkg−1, and the limit of quantification (LOQ) was defined from 5.0 to 50.0µgkg−1 for individual analytes. The resultant recovery values ranged from 98.1% to 107.3% in repeatability conditions and from 95.2% to 106% under intralaboratory reproducibility conditions for the studied analytes. It was concluded that the performance parameters demonstrated total method adequacy for detecting and quantifying β-lactam and tetracycline residues in swine, equine, bovine, and avian kidneys.

Development and validation of determinative and confirmatory LC-MS/MS methodologies for total florfenicol and tulathromycin residues in bovine, equine and porcine kidney, liver and muscle tissues.

Separate methods for the quantitation and confirmation of regulatory relevant residue concentrations of total florfenicol and tulathromycin residues in multiple tissue matrices were developed and validated. Total florfenicol residues, determined and expressed as florfenicol amine (FFA) equivalents, were quantified and confirmed over a concentration range of 100-4000ng/g, with an LOD of 33ng/g, while total tulathromyicn residues, determined as CP-60,300 and expressed as tulathromycin equivalents, were quantified and confirmed over a concentration range of 500-10,000ng/g, with an LOD of 300ng/g. A 2 or 1h acid digestion for the FFA and tulathromycin methods, respectively, followed by extraction, cleanup, and concentration using mixed-mode strong cation-exchange SPE cartridges was used. Quantitation and confirmation were accomplished using commercially available tri-deuterated FFA (FFA-D3) as internal standard and multiple reaction monitoring (MRM) of three transitions per target analyte. Mean recoveries and matrix effects were 60% and 25%; and 100% and 110%, respectively for the target analytes florfenicol amine and CP-60,300. Intra-lab method reproducibilities ranged from 7 to 11% RSD, which are within the AOAC recommended HORRATr guidelines for method reproducibilities estimated from single laboratory validation studies. Blind spikes showed that method bias was generally less than 15% for both methods within the calibration range. Both methods have been shown to meet requirements for use in national chemical residue monitoring programs.

Performance characterization of a quantitative liquid chromatography-tandem mass spectrometric method for 12 macrolide and lincosamide antibiotics in salmon, shrimp and tilapia.

This paper describes an extension and performance characterization of a quantitative confirmatory multi-residue liquid chromatography-tandem mass spectrometric method for residues of macrolide and lincosamide antibiotics, originally validated for application to bovine kidney tissues, to tissues of salmon, shrimp and tilapia. The 12 analytes include clindamycin, erythromycin A, gamithromycin, josamycin, lincomycin, neospiramycin 1, oleandomycin, pirlimycin, spiramycin 1, tildipirosin, tilmicosin and tylosin A. The limit of detection was 0.5 μg/kg. Within-laboratory precision evaluated over the analytical range of 5.0-50.0 μg/kg ranged from 4 to 17%. The accuracy of the method ranged from 80 to 112%. Recoveries ranged from 47 to 99% with all but one recovery above 60%. This is the first report of a quantitative confirmatory method for gamithromycin, pirlimycin and tildipirosin in fish and shrimp.

English

The effect of gamma irradiation on the radiofrequency dielectric properties of bovine kidney tissue has been investigated using gamma irradiator (Gs 1000), booton (7200) capacitance meter, signal generator (Lodstars SG-416013) and Dielectric cells Mathematic models of the following dielectric structural parameter, Dielectric spread parameter (), dielectric decrement () and Dielectric relaxation time (), were also developed. The mathematics models were found to be polynomial functions of degree 4,4, and 5 respectively. The coefficient of fit for dielectric decrement, relaxation time and spread parameter (), were found to be 98.2, 83.9 and 99.5, respectively. This shows that, the mathematical model can be effectively used to generate dielectric data that will facilitate the prediction of the extent of mammalian kidney tissue damage in gamma irradiation doses regime usually encountered in diagnostic and therapeutic radiology. &nbsp; Key words: Gamma irradiation, spread parameter (), dielectric decrement (), dielectric relaxation time (), dielectric permittivity (). &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;

Rapid analysis of aminoglycoside antibiotics in bovine tissues using disposable pipette extraction and ultrahigh performance liquid chromatography–tandem mass spectrometry

A high-throughput qualitative screening and identification method for 9 aminoglycosides of regulatory interest has been developed, validated, and implemented for bovine kidney, liver, and muscle tissues. The method involves extraction at previously validated conditions, cleanup using disposable pipette extraction, and analysis by a 3min ultrahigh-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method. The drug analytes include neomycin, streptomycin, dihydrosptreptomycin, and spectinomycin, which have residue tolerances in bovine in the US, and kanamicin, gentamicin, apramycin, amikacin, and hygromycin, which do not have US tolerances established in bovine tissues. Tobramycin was used as an internal standard. An additional drug, paromomycin also was validated in the method, but it was dropped during implementation due to conversion of neomycin into paromomycin. Proposed fragmentation patterns for the monitored ions of each analyte were elucidated with the aid of high resolution MS using a quadrupole-time-of-flight instrument. Recoveries from spiking experiments at regulatory levels of concern showed that all analytes averaged 70–120% recoveries in all tissues, except hygromycin averaged 61% recovery. Lowest calibrated levels were as low as 0.005μg/g in matrix extracts, which approximately corresponded to the limit of detection for screening purposes. Drug identifications at levels <0.05μg/g were made in spiked and/or real samples for all analytes and tissues tested. Analyses of 60 samples from 20 slaughtered cattle previously screened positive for aminoglycosides showed that this method worked well in practice. The UHPLC–MS/MS method has several advantages compared to the previous microbial inhibition screening assay, especially for distinguishing individual drugs from a mixture and improving identification of gentamicin in tissue samples.

Histological analysis of biological tissues using high-frequency ultrasound

High-frequency (20-80 MHz) ultrasonic measurements have the potential to detect cancer and other pathologies within breast tissues in real time, and thus may assist surgeons in obtaining negative or cancer free margins during lumpectomy. To study this approach, ultrasonic tests were performed on 34 lumpectomy margins and other breast tissue specimens from 17 patients to provide pulse-echo and through-transmission waveforms. Time-domain waveform analysis yielded ultrasonic attenuation, while fast Fourier transforms of the waveforms produced first- and second-order ultrasonic spectra. A multivariate analysis of the parameters derived from these data permitted differentiation of normal, adipose, benign, and malignant breast pathologies. The results provide a strong correlation between tissue microstructure and ultrasonic parameters relative to the morphology and stiffness of microscopic features such as ductules, lobules, and fibrous structures. Ultrasonic testing of bovine heart, liver, and kidney tissues supports this correlation, showing that tissues having stiff fiber-like or filled-duct structures, such as myocardium or ductal carcinomas, display greater peak densities in the ultrasonic spectra than tissues with soft, open duct-like structures, such as kidney tissue or normal breast glands. The sensitivity of high-frequency ultrasound to histopathology may assist in eliminating invasive re-excision for lumpectomy patients. [Work supported by NIH R21CA131798.]