Determination of tetracycline antibiotic residues in edible swine tissues by liquid chromatography with spectrofluorometric detection and confirmation by mass spectrometry   总被引：1，自引：0，他引：1  

Pena A  Lino CM  Alonso R  Barceló D 《Journal of agricultural and food chemistry》2007,55(13):4973-4979

A sensitive and specific method is described for the simultaneous determination of oxytetracycline, tetracycline (TC), and chlortetracycline residues in edible swine tissues, by combining liquid chromatography with spectrofluorometric and mass spectrometry detection. The procedure involved a preliminary extraction with EDTA-McIlvaine buffer acidified at pH 4.0, followed by solid-phase extraction cleanup using a polymeric sorbent. The liquid chromatography analysis was performed with spectrofluorometric detection after postcolumn derivatization with magnesium ions. The limits of quantification were 50 microg/kg for muscle and 100 microg/kg for kidney tissues. The recovery values were greater than 77.8% for muscle and 65.1% for kidney. The method has been successfully used for the quantification of tetracyclines in swine tissues samples. The selective liquid chromatography mass spectrometric analysis for confirmation of oxytetracycline in one positive swine muscle sample was made by atmospheric pressure chemical ionization (APCI). The APCI mass spectra of the TCs gave the protonated molecular ion and two typical fragment ions, required for their confirmation in single ion monitoring scan mode in animal tissues.  相似文献   

Relationship of Progesterone,Bovine Pregnancy-Associated Glycoprotein-1 and Nitric Oxide with Late Embryonic and Early Fetal Mortalities in Dairy Cows     

Aly KAREN  árpád Csaba BAJCSY  Rosa MINOIA  Rezs? KOVáCS  Noelita Melo DE SOUSA  Jean-Fran?ois BECKERS  János TIBOLD  István MáDL  Ottó SZENCI 《The Journal of reproduction and development》2014,60(2):162-167

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.  相似文献   

Effect of Breeding Activity on the Microflora of the External Genitalia and in the Semen of Stallions,and the Relationship Between Micro‐organisms on the Skin and on the External Genitalia     

T Guimarães  C Miranda  M Pinto  E Silva  L Damásio  AL Costa  MJ Correia  JC Duarte  C Cosinha  G Lopes  G Thompson  A Rocha 《Reproduction in domestic animals》2014,49(6):926-933

A possible role of breeding activities in the composition of the microbial population in stallions' external genitalia (EG) and the relationship between micro‐organisms colonizing the skin of the abdomen and the ones colonizing the EG have not been studied. In experiment 1, EG microbiological samples were collected from 41 stallions used for both natural cover and semen collection (BST) and from 18 non‐breeding stallions (NBST). A higher (p < 0.05) frequency of isolation of potentially pathogenic species was found for BST. Age did not influence number of micro‐organism species isolated both in BST and NBST. In experiment 2, the microbial content of the EG and semen was compared in 23 BST. Most micro‐organisms isolated from the EG were present in semen, albeit with a numerically lower prevalence. In 7 stallions, six microbial species isolated from semen were absent from the EG cultures, suggesting contamination by the operator. In experiment 3, a numerically higher number of micro‐organism species was isolated from the EG of 31 stallions, than from their skin of the ventral abdomen in contact with the penis or from the skin of the thorax. With the sole exception of Escherichia coli, potentially pathogenic bacteria were only isolated from the EG but not from the skin. Results suggest that breeding activity increased the number of species colonizing the EG; most species isolated from the EG were also found in semen even if with a lower frequency, and additional semen contamination seemed to occur during its manipulation. Many micro‐organism species of the skin were also isolated from the penis, but independently of being or not in contact with the penis, skin did not seem to provide an adequate environment for the growth of potentially pathogenic bacteria that were isolated from EG, with the sole exception for E. coli.  相似文献   

Effects of paraquat treatment on fish transaminase molecular subforms     

K. Aranka Deér  János Nemcsók  LászIó Boross  Béla Szajáni 《Fish physiology and biochemistry》1990,8(1):79-83

The effects of paraquat (PQ; 1,1′-dimethyl-4,4′-bipyridylium dichloride) treatment were investigated in carp, silver carp and wels. The serum glutamic-oxalacetic transaminase (GOT; L-aspartate: 2-oxoglutarate aminotransferase, EC 2.6.1.1.) level was enhanced by 50% at 1 ppm exposure and by 100% at 10 ppm exposure in all species, and there was a change in the distribution of the molecular subforms of GOT in the liver and heart. The activities of the individual subforms decreased with increasing PQ concentration or after a longer exposure. In some cases, one of the subforms was no longer present in the liver. An increased serum GOT activity, a decreased enzyme activity in different organs and the disappearance of molecular subform indicate tissue damage.  相似文献   

Recovery of bioactive compounds from Pinus pinaster wood by consecutive extraction stages     

Enma Conde  Wenwen Fang  Jarl Hemming  Stefan Willför  Herminia Domínguez  Juan Carlos Parajó 《Wood Science and Technology》2014,48(2):311-323

Pinus pinaster wood samples, obtained at different positions of three healthy trees, were subjected to two sequential extractions using an Accelerated Solvent Extraction instrument. The first extraction was carried out with hexane (to remove lipophilic extractives) and the second one with acetone/water (95:5 v/v) to recover bioactive phenolic compounds, the target compounds of this study. The extracted fractions were assayed for total yield and composition. The extracts contained a spectrum of phenolic compounds (simple phenolics, phenolic stilbenes, flavonoids and lignans) and non-phenolic components (juvabiones, resin and fatty acids, steryl esters and triglycerides). The fractionation effects achieved by consecutive extractions and the recovery of bioactive phenolics are discussed.  相似文献   

Development and evaluation of a rapid absorbed enzyme immunoassay test for the diagnosis of Johne''s disease in cattle   总被引：8，自引：0，他引：8  

JC COX  DP DRANE  SL JONES  S. RIDGE†  AR MILNER† 《Australian veterinary journal》1991,68(5):157-160

An absorbed enzyme immunoassay (EIA) test for Johne's disease in cattle was developed in which absorption of cross-reacting antibodies occurred as a rapid reaction in solution rather than overnight with whole organisms and a subsequent centrifugation step. Total test time was reduced to less than 2 h with a minimum of manipulations. The test was evaluated in cattle herds from Johne's disease-endemic and Johne's disease-free regions of Australia. Specificity was 99.8%. Calculations of sensitivity were affected by the history of the herd under test. However, the EIA detected in excess of 80% of animals before onset of clinical disease and 65% of faecal shedders were EIA positive on, or before, first detection of Mycobacterium paratuberculosis in their faeces. The test should aid epidemiological studies and be a useful tool in the management and control of Johne's disease.  相似文献   

The prevalence of itchmite, Psorergates ovis, among sheep flocks with a history of fleece derangement     

PW JOHNSON  JW PLANT  JC BORAY  SC BLUNT  PJ NICHOLLS 《Australian veterinary journal》1990,67(4):117-120

An investigation of sheep flocks in the main sheep raising areas of New South Wales showed that the itchmite Psorergates ovis was frequently associated with fleece derangement. In 26 of the 41 flocks examined, P. ovis was the only ectoparasite detected. P. ovis and the sheep body louse Damalinia ovis, were found in 5 flocks. No external parasites were found on sheep examined from the 10 remaining flocks. The type of fleece derangement most frequently recorded was rubbing which in some cases was combined with areas of chewed fleece. Among flocks, there were positive relations between the prevalence of fleece derangement and prevalence of itchmite or scurf and between itchmite count and mean scurf score. Within flocks, itchmite infested sheep or sheep with scurf had higher prevalences of fleece derangement than sheep on which no mites or no scurf were found. Itchmite infested sheep had a higher prevalence of scurf than those with no detectable mite infestation. There were no significant differences in itchmite populations or fleece derangement between untreated flocks and flocks treated with synthetic pyrethroids, organophosphates or arsenic and rotenone.  相似文献   

Assessment of the production of antioxidants from winemaking waste solids     

Cruz JM  Domínguez H  Parajó JC 《Journal of agricultural and food chemistry》2004,52(18):5612-5620

Winemaking waste solids (WS, resulting from red grapes after fermentation and distillation to recover spirits) were subjected to various processing schemes for isolating fractions with antioxidant activity. The liquors entrapped in WS as received were separated by pressing and freeze-dried to yield a fraction with antioxidant activity (measured as DPPH radical scavenging capacity) comparable to those of synthetic antioxidants. A second approach based on the direct processing of raw WS in sulfuric acid medium under fixed operational conditions and further extraction of hydrolysis liquors with ethyl acetate enabled the isolation of a fraction with higher antioxidant ability at an improved yield. The most favorable approach started with a washing stage leading to liquors (which were directly freeze-dried to yield 1.20 g of extract/100 g of oven-dry WS and presented an EC50 of 0.41 g of extract/L) and washed solids, which were dried and subjected to hydrolytic processing (i) with water as a reactive in an autocatalyzed reaction (autohydrolysis) or (ii) with sulfuric acid solutions to give an ethyl acetate-soluble fraction with improved antioxidant properties (EC50 in the range of 0.18-0.40 g/L). Samples from washing liquors and processing of washed solids in aqueous medium were subjected to chromatographic fractionation and analysis to give isolates with remarkable antioxidant activity (with EC50 as low as 0.07 g/L) and to identify their major components.  相似文献   

Study of some Saccharomyces cerevisiae strains for winemaking after preadaptation at low temperatures     

Llauradó JM  Rozès N  Constantí M  Mas A 《Journal of agricultural and food chemistry》2005,53(4):1003-1011

Low-temperature fermentations (13 degrees C) are considered to improve wine aromatic profiles. However, because the risk of stuck and sluggish fermentations is high, these fermentations are not common. The aim of this paper was to analyze the effect of different preadaptation protocols in two commercial wine strains on the fermentation and some wine parameters. Preadaptation is understood to be the process between the rehydration of active dry yeast and the inoculation. In this study, it consisted of preparing a fermentation starter (addition of yeast grown at 25 degrees C) or inocula preadapted at low temperatures (as before, but grown at a fermentation temperature of 13 or 17 degrees C). These results were compared with those of rehydrated active dry yeast, and a commercial "cryotolerant" yeast was used as a reference. General fermentation kinetic parameters, yeast imposition, nitrogen consumption, and main wine products were analyzed. The results showed that the preadaptation of a yeast could improve the fermentation performance, although this improvement was strain-dependent. Low-temperature fermentations also had some general effects: reduction of acetic acid and fusel alcohol production and increased concentrations of glycerol. When the yeast performed better in fermentation because of preadaptation, nitrogen consumption was faster and the wine's "negative" attributes (acetic acid, fusel alcohols) were significantly reduced. Thus, in some strains, preadaptation could be an effective mechanism for improving low-temperature fermentation, which also significantly reduces detrimental wine attributes.  相似文献   

Human apo A-I and rat transferrin are the principal plasma proteins that bind wine catechins     

Brunet MJ  Bladé C  Salvadó MJ  Arola L 《Journal of agricultural and food chemistry》2002,50(9):2708-2712

The processes of absorption, blood transport, tissular distribution, metabolism, and excretion are at present understood very little. The aim of this study was to investigate blood transport and identify which principal plasma proteins in humans and rats bind to monomeric catechin and procyanidins in red wine ex vivo. Human and rat plasma and serum were incubated with (+)-catechin and procyanidins from grape seed, the origin of red wine catechins. Proteins were separated by SDS-PAGE and native-PAGE to determine which proteins bound to these compounds. The principal protein that bound to (+)-catechin in each species was sequenced. SDS-PAGE showed that (+)-catechin and procyanidins mainly bound to a protein of about 80 kDa in rats and 35 kDa in humans. Their sequencing indicated that these proteins were apo A-I in humans and transferrin in rats. The fact that red wine procyanidins bind to both proteins suggests that they may have a role in reverse cholesterol transport and in the oxidizing action of iron.  相似文献