Determination of lidocaine and its two N-desethylated metabolites in dog and horse plasma by high-performance liquid chromatography combined with electrospray ionization tandem mass spectrometry

peer reviewedA sensitive method for the quantification of lidocaine and its metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), in animal plasma using high-performance liquid chromatography combined with electrospray ionization mass spectrometry is described. The sample preparation includes a liquid-liquid extraction with methyl tert-butylmethyl ether after addition of 2 M sodium hydroxide. Ethyl methylglycinexylidide (EMGX) is used as an internal standard. For chromatographic separation, an ODS Hypersil column was used. Isocratic elution was achieved with 0.0 1 M ammonium acetate and acetonitrile as mobile phases. Good linearity was observed in the range of 2.5-1000 ng ml(-1) for lidocame in both dog and horse plasma. For MEGX, linear calibration curves were obtained in the range of 5-1000 ng ml(-1) and 20-1000 ng ml(-1) for dog and horse plasma, respectively. In dog and horse plasma good linearity was observed in the range of 200-1500 ng ml(-1) for GX. The limit of quantification (LOQ) in dog plasma for lidocaine, MEGX and GX was set at 2.5 ng ml(-1), 20 ng ml(-1) and 200 ng ml(-1), respectively. For horse plasma a limit of quantification of 2.5 ng ml(-1), 5 ng ml(-1) and 200 ng ml(-1) was achieved for lidocaine, MEGX and GX, respectively. In dog plasma, the limit of detection (LOD) was found to be 0.8 ng ml(-1), 2.3 ng ml(-1) and 55 ng ml(-1) for lidocaine, MEGX and GX, respectively. In horse plasma the LOD's found for lidocame, MEGX and GX, were 1.1 ng ml(-1), 0.5 ng ml(-1) and 13 ng ml(-1), respectively. The method was shown to be of use in pharmacokinetic studies after application of a transdermal patch in dogs and after an intravenous infusion in horses. (c) 2007 Elsevier B.V. All rights reserved

Addressing food and nutrition insecurity in the Caribbean through domestic smallholder farming system innovation

Structural conditions underlying the development of CARICOM’s two-tiered agricultural innovation system depict diverse drivers of change over time, versus institutional inertia of export-oriented formal institutions and the neglect of informal domestic markets. Key principles of taking an agroecological approach would include: supporting diversity and redundancy, building connectivity, managing slow variables and feedbacks, improving understanding of socioecological systems as complex adaptive systems, and encouraging polycentric governance systems. In this paper, we review the conditions that have been undermining sustainable food and nutrition security in the Caribbean, focusing on issues of history, economy, and innovation

Osteochondrosis-Related Gene Expression in Equine Leukocytes Differs among Affected Joints in Foals

peer reviewedOsteochondrosis (OC) is a developmental disease in horses with a significant impact on the horse’s welfare and performance. Previously, differentially expressed genes in leukocytes of OC-affected have been identified and were differentially expressed in horses of different ages when compared to their age-matched controls.As the time course of the development of OC lesions seems to be joint dependent,the aim of this study is to compare in young OCaffected horses (between 8 to 12 months), the different expression of selected genes depending the joints involved.The expression of OC-related genes were analysed by rt-PCR and subsequent statistical analysis (ΔΔCT) in the leukocytes of 30 Belgian Warmblood horses aged between 8 to 12 months divided in groups depending the affected joints (fetlock, hock and stifle).In the three groups, expression of ApoB-3G, MGAT4A, B4GALT6 and PRKCG genes were significantly higher in the OC-affected foals compared to the healthy foals. Based on the profiles of expression ofApoB-3G, Dsh1/Dvl1, Foxl1, Hp, ISG15, Mark2, PPR2A, RUSC2 and WASH1 genes,the localization of the disease can be determined: expression levels of ApoB3G, WASH1 and FOXl1 to identify fetlock, ApoB3G, PPR2A to identify OC-development in the hock and ApoB3G, Dsh1/Dvl1, WASH1, PPP2R1A and Mark2 geneto identify OC-development in the stifle. However at this moment, the rt-PCR analysis of the identified genes as biomarkers gives only diagnostic information. For the future, the profile of expression of these genes could give also some predictive information on the evolution of the disease such as remission or permanent OC-lesions.Soutien à la filière équin

Age-dependent expression of osteochondrosis-related genes in equine leukocytes

Introduction: Osteochondrosis (OC) is a developmental disease in horses which has a significant impact on the horse’s welfare and performance. The early disturbance in the process of endochondral ossification progresses to inflammatory and repair processes in older horses. Previously, differentially expressed genes in leukocytes of OC-affected horses have been identified. The aim of the present study is to detect age-related changes in these differentially expressed genes. Materials and Methods: The expression of OC-related genes was analysed by real-time PCR and subsequent statistical analysis (ΔΔCT) in the leukocytes of 135 Belgian Warmblood horses divided into three different age groups: 30 months (n=38). Results: Relative expression of genes of horses less than 12 months of age showed significant induction of the genes MGAT4A, PRKCG, MHCI, ApoB, ApoB3G, B4GALT6 and a significantly lower expression of the genes OAS3. Horses of 18–24 months of age, showed a significantly higher expression of the genes TBC1D9, MGAT4A, IFIH1, MHCIIa and MMP1. Horses of more than 30 months of age showed a significantly higher expression of the genes MGAT4A, HP, SECTM1 compared with their age-matched control groups. Conclusions: The study demonstrates that OC-related genes are differentially expressed in horses of different ages compared with their age-matched controls. Some of the genes may be implicated in cell signalling and differentiation as well as carbohydrate and lipid metabolism and inflammation. However, the causal relationship between the differentially expressed genes and the development and progression of the OC lesions needs to be determined

Evaluation of the influence of age on pulmonary arterial pressure by use of right ventricular catheterization, pulsed-wave Doppler echocardiography, and pulsed-wave tissue Doppler imaging in healthy Beagles

info:eu-repo/semantics/publishe

Enhanced survival of lung granulocytes in an animal model of asthma: evidence for a role of GM-CSF activated STAT5 signalling pathway

BACKGROUND—As granulocyte/macrophage colony stimulating factor (GM-CSF) mediated delay of granulocyte apoptosis contributes to the accumulation of inflammatory cells at the site of inflammation in many diseases, we sought to determine whether asthma is also associated with a GM-CSF dependent increase in lung granulocyte survival. Moreover, because GM-CSF mediates its effects through activation of signal transducer and activator of transcription 5 (STAT5), we also investigated the potential role of STAT5 in allergic inflammation.
METHODS—Blood granulocytes were recovered from six healthy and six heaves affected horses, a model of asthma. Lung granulocytes were obtained by bronchoalveolar lavage (BAL) from the same horses. Granulocytes were cultured in the presence or absence of anti-GM-CSF receptor antibodies for different times and apoptosis was determined using the Annexin-V/propidium iodide detection method. Nuclear protein extracts from cultured granulocytes were analysed for STAT5 binding activity by electrophoretic mobility shift assay.
RESULTS—BAL fluid granulocytes from heaves affected horses demonstrated a significant delay in apoptosis compared with blood granulocytes from the same horses and blood and BAL fluid granulocytes from healthy horses. Conversely, the rate of apoptosis in blood granulocytes from healthy and heaves affected horses was comparable. The enhanced survival of BAL fluid granulocytes from affected horses was suppressed in the presence of antibodies directed against GM-CSF receptors. Increased levels of active STAT5 were found in BAL fluid granulocytes from heaves affected horses and were markedly reduced after treatment with anti-GM-CSF receptor antibodies.
CONCLUSIONS—These data indicate that granulocyte survival is enhanced in the lung of heaves affected horses and suggest a role for a GM-CSF activated STAT5 pathway in delaying apoptosis of lung granulocytes in this model of asthma.