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Ousey J.C.,High Street Partners
Equine veterinary journal. Supplement | Year: 2012

Prostaglandins play an essential role during the perinatal period in the mare. Prostaglandin concentrations are low for the majority of pregnancy due to the regulatory action of progestagens on those enzymes responsible for metabolism of prostaglandins. Towards term, prostaglandin concentrations gradually increase, closely associated with upregulation of the fetal hypothalamo-pituitary-adrenal axis, stimulation of the prostaglandin synthesising enzyme PGHS-2 and changes in the ratio of progestagens and oestrogens. Recent evidence in the mare indicates that proinflammatory cytokines are key mediators of prostaglandin synthesis both at term parturition in healthy mares and at preterm parturition associated with placental infection. Prostaglandin concentrations rise substantially during active labour and decline after birth, associated with delivery of the placenta. During induced labour, prostaglandin concentrations are variable depending on the proximity to spontaneous parturition at term. Once the proinflammatory endocrine cascade is initiated, it is difficult to prevent active labour by administration of drugs that reduce prostaglandin concentrations in peripheral plasma. Further work is needed to establish the inter-relationships between prostaglandin production and other endocrine changes associated with labour at term and preterm in the mare.

Oddsdottir C.,University of Edinburgh | Riley S.C.,Queens Medical Research Institute | Leask R.,Queens Medical Research Institute | Shaw D.J.,University of Edinburgh | And 5 more authors.
Theriogenology | Year: 2011

During late gestation in the mare, rapid fetal growth is accompanied by considerable placental growth and further invasion of the endometrium by microvilli. This growth requires extensive remodeling of the extracellular matrix (ECM). In early pregnancy, we know that matrix metalloproteinase (MMP)-9 and -2 are involved in the endometrial invasion during endometrial cup formation. The present study investigated whether MMPs are found in fetal fluids later in gestation and during parturition, and if there was a difference in their activities between normal and preterm delivery. Amniotic fluids were collected from pony mares during the latter half of gestation, and amniotic and allantoic fluids from pony and thoroughbred mares at foaling. The fluids were analysed for the activity of MMP-9 and -2, and TIMPs using zymography techniques. There was an increase (P = 0.002) in activity of latent MMP-9 when approaching normal foaling, and a decrease (P < 0.001) during foaling. MMP-2 activity did not change through gestation, or during foaling. When comparing samples from pregnancies resulting in preterm deliveries with samples from foaling mares, the activity of MMP-9 was lower (P < 0.001) and MMP-2 activity was higher (P = 0.004) during foaling than preceding preterm delivery. The activity of MMP-9 was lower (P = 0.002) prior to preterm delivery than before delivery of a live foal at term, whereas no difference (P = 0.07) was demonstrated for latent MMP-2 activity when comparing the same groups. The activity of TIMP-2 was higher (P < 0.001) in the pre-parturient period before normal foaling than preceding preterm delivery. These results suggest that MMPs may have a role as markers for high risk pregnancy in the mare. © 2011.

Peters S.E.,University of Cambridge | Paterson G.K.,University of Cambridge | Bandularatne E.S.D.,University of Cambridge | Bandularatne E.S.D.,National University of Singapore | And 14 more authors.
Infection and Immunity | Year: 2010

In Salmonella enterica serovar Typhimurium, trxA encodes thioredoxin 1, a small, soluble protein with disulfide reductase activity, which catalyzes thiol disulfide redox reactions in a variety of substrate proteins. Thioredoxins are involved as antioxidants in defense against oxidative stresses, such as exposure to hydrogen peroxide and hydroxyl radicals. We have made a defined, complete deletion of trxA in the mouse-virulent S. Typhimurium strain SL1344 (SL1344 trxA), replacing the gene with a kanamycin resistance gene cassette. SL1344 trxA was attenuated for virulence in BALB/c mice by the oral and intravenous routes and when used in immunization experiments provided protection against challenge with the virulent parent strain. SL1344 trxA induced less inflammation in murine spleens and livers than SL3261, the aroA mutant, live attenuated vaccine strain. The reduced splenomegaly observed following infection with SL1344 trxA was partially attributed to a reduction in the number of both CD4+ and CD8+ T cells and B lymphocytes in the spleen and reduced infiltration by CD11b+ cells into the spleen compared with spleens from mice infected with SL3261. This less severe pathological response indicates that a trxA mutation might be used to reduce reactogenicity of live attenuated vaccine strains. We tested this by deleting trxA in SL3261. SL3261 trxA was also less inflammatory than SL3261 but was slightly less effective as a vaccine strain than either the SL3261 parent strain or SL1344 trxA. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Parsons D.,High Street Partners | Goodhew S.,Nottingham Trent University | Fewkes A.,Nottingham Trent University | de Wilde P.,University of Plymouth
Urban Water Journal | Year: 2010

This work investigates the barriers that exist to deter the implementation of rainwater harvesting into new UK housing. A postal questionnaire was sent to a selection of large, medium and small house-builders distributed across the UK. Questions were asked concerning potential barriers to the inclusion of rainwater harvesting in homes separated into five sections;(1) institutional and regulatory gaps, (2) economic and financial constraints, (3) absence of incentives, (4) lack of information and technical knowledge, and (5) house-builder attitudes. The study concludes that although the knowledge of rainwater systems has increased these barriers are deterring house-builders from installing rainwater harvesting systems in new homes. It is further acknowledged that the implementation of rainwater harvesting will continue to be limited whilst these barriers remain and unless resolved, rainwater harvesting's potential to reduce the consumption of potable water in houses will continue to be limited. © 2010 Taylor & Francis.

Cropp N.,High Street Partners | Cropp N.,University of Surrey | Hellawell E.,University of Surrey | Elghali L.,University of Surrey | Banks A.,University of Surrey
Land Contamination and Reclamation | Year: 2010

Judgement forms an integral part of a risk-based approach to the assessment of land affected by contamination. Legislation and guidance suggest that the assessor should use a rational step-wise process to identify pollutant linkages in order to assess risk from land contamination. The present study aims to investigate the decision-making processes that are used by experienced contaminated land assessors. This study required 29 participants with a minimum of five years' relevant experience to rate the level of risk from land contamination on 27 hypothetical housing development sites. Each site was designed with specific information (variables) used as indicators of the potential for unacceptable risk. Linear regression analysis was used to identify the significance of each of the variables in determining the level of risk assessed by participants. The first of the key findings was that considerable disagreement was observed between participants, and this was correlated to cases with contradictory information. This may have also been related to the participant's perception of the available risk scale. The linear regression analysis showed that the most influential variables were chemical-test data and the presence of human-exposure pathways. These findings would suggest that experienced assessors focus on a few key aspects of the information available to assess risk from land contamination. However, analysis of the qualitative data collected in the study supported a more holistic decision-making process, in line with use of pollutant linkages described in guidance. The results suggest that when presented with limited data for development sites, assessors may rely on a few variables to rate the risk, but that a coherent picture of the interaction of all of the variables is required for a more confident assessment. The findings of the study presented here can be used to inform training and future guidance in this sector. © 2010 EPP Publications Ltd.

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