10 results on '"Olmos G"'
Search Results
2. Photoinduced phenomena in nanostructured porous silicon
- Author
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Arce, R.D., Koropecki, R.R., Olmos, G., Gennaro, A.M., and Schmidt, J.A.
- Published
- 2006
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3. A reduction in milking frequency and feed allowance improves dairy cow immune status.
- Author
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O'Driscoll, K., Olmos, G., Llamas Moya, S., Mee, J. F., Earley, B., Gleeson, D., O'Brien, B., and Boyle, L.
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DAIRY cattle , *MILKING , *CATTLE , *BLOOD proteins , *COMPOSITION of milk - Abstract
Twice-daily milking is the most common milking regimen used globally. A reduction in milking frequency to once daily, combined with a reduced feed allowance (FA), could reduce the physiological stress associated with the transition to peak milk production, and hence improve immune function. This study investigated how milking frequency and FA affect dairy cow immune status. Cows (n = 48) were milked once a day (OAD) or twice a day (TAD) on 1 of 2 FA: high (HFA) or low (LFA), in a 2 x 2 factorial arrangement of treatments. After the mean calving date of March 11, HFA cows were offered ad libitum grass silage and 7 kg of concentrates/cow per day until March 22, then 4 kg of concentrates/cow per day until April 17, and thereafter allocated 31.3 kg of dry matter (DM) grass/cow per day. The LFA cows were offered 4 kg of concentrates/cow per day, 1 kg of concentrates/cow per day, and allocated 19 kg of DM grass/cow per day for the same respective periods. Milk yield was recorded daily and body condition score weekly, and somatic cell count was performed at approximately 2-wk intervals. Blood samples were collected prepartum (d -7 to -1) and at d 1 to 7, d 14 to 21, and d 42 to 49 postpartum. Total and differential leukocyte percentage, IFN-ᵞ. production in response to concanavalin A and phytohemagglutinin, and cortisol, haptoglobin (Hp), and serum amyloid A (SAA) concentrations were evaluated. Cows milked OAD had reduced milk yield and body reserve mobilization, but higher somatic cell counts. Milking frequency and diet had no effect on total leukocyte counts. Cows milked OAD had a higher lymphocyte percentage and lower monocyte percentage, and tended to have a lower neutrophil percentage than cows milked TAD. In addition, the LFA cows had a higher eosinophil percentage than cows fed the HFA. Milking frequency and diet had no effect on IFN-ᵞ, Hp, SAA, or cortisol production. Utilization of strategies to reduce milk yield at the beginning of the lactation could not only reduce body reserve mobilization, but also help to maintain a functioning immune system, and thus improve cow welfare. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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4. Retrospective Analysis of Post-Mortem Findings in 1,444 Aged Donkeys.
- Author
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Morrow, L.D., Smith, K.C., Piercy, R.J., du Toit, N., Burden, F.A., Olmos, G., Gregory, N.G., and Verheyen, K.L.P.
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RETROSPECTIVE studies ,AUTOPSY ,DONKEYS ,PATHOLOGY ,ANEURYSMS ,ULCERS ,ARTHRITIS ,BODY weight - Abstract
Summary: The aim of this study was to describe and report the prevalence of conditions found at necropsy examination of UK donkeys. Records from 1,444 donkeys over a 7-year period were included in the analysis. Sixty-one categories of post-mortem finding were identified from 9,744 observations. The four most prevalent conditions noted were dental disorder (78.7%), vascular disease other than aneurysm (60.9%), arthritis (55.4%) and foot disorder (44.8%). Gastric ulceration was found in 42% of the donkeys and gastrointestinal impaction in 18.6%. The most frequent combination of two post-mortem findings in the same animal was arthritis and dental disorder. The most common disorders were associated with age, body weight and/or body condition post mortem and, for some disorders, gender. For many of the post-mortem findings, crude associations were found between the presence of one finding and the odds of also having certain other post-mortem findings. This study is the first to summarize all conditions noted at necropsy examination for a large group of donkeys. The findings increase knowledge of diseases and conditions of this species and may be useful when investigating the relevance of various pathological conditions in the live animal. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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5. Effect of Holstein-Friesian genetic group on peripartum and early lactation haematological and acute phase proteins profiles, health and fertility.
- Author
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Olmos, G., Boyle, L., Horan, B., Berry, D. P., Sayers, R., Hanlon, A., and Mee, J. F.
- Subjects
HOLSTEIN-Friesian cattle ,HEMATOLOGY ,MILK yield ,CATTLE diseases ,ESTIMATION theory ,STATISTICAL correlation - Abstract
Pasture-based Holstein-Friesian cows from three genetic groups differing in the Irish 'Economic Breeding Index' (EBI) value and genetic background, namely North-American (NA) national average EBI genetic merit (LOW-NA, n = 42), North-American high EBI genetic merit (HIGH-NA, n = 42) and New Zealand (NZ) high EBI genetic merit (HIGH-NZ, n = 42), were studied. These genetic groups have been selected in different environments: pasture for NZ and confinement for NA. The objective was to determine the effect of genetic group on haematological and acute phase proteins profiles (white blood cell (WBC) counts, red blood cell (RBC) counts, acute phase proteins: serum amyloid A (SAA) and haptoglobin), health (rectal temperature (RT), clinical mastitis (CM) and somatic cell score), calving performance (stillbirth, calving assistance) and post-partum reproductive parameters (endometritis and ovarian cyclicity). Blood sampling and data recording took place 3 weeks pre-calving up to 7 weeks post-calving. Linear mixed models, logistic regression and generalised estimating equations were used for data analysis. HIGH-NZ animals had the highest (P < 0.05) RBC mean corpuscular volume (50.0 fl), exhibited a different WBC distribution pattern (P < 0.05) and had the lowest (P < 0.05) mean RT (38.4°C) for the first 10 days post-calving. These findings suggest enhanced reticulocyte turnover, peripartum response mechanisms and thermoregulation in the HIGH-NZ compared to the other two genetic groups. LOW-NA animals had the highest SAA peak throughout the peripartum period (55.12 mg/l, P < 0.05) and a tendency for higher somatic cell scores ( P < 0.10) in early lactation. The HIGH-NA animals had the lowest incidence of udder quarter milk sample bacteria at calving, suggesting better udder health when commencing lactation. No differences were detected between genetic groups in calving performance, post-partum reproductive parameters or CM in the first 42 days post-calving. These results suggest that while inherited peripartum adaptation strategies have been developed by the different genetic groups selected in different environments (pasture = NZ v. confinement = NA), such differences have minimal impact on peripartum clinical health. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
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6. My pigs are ok, why change? – animal welfare accounts of pig farmers.
- Author
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Albernaz-Gonçalves, R., Olmos, G., and Hötzel, M.J.
- Abstract
Intensive pig production systems are a source of stress, which is linked to reduced animal welfare and increased antimicrobial use. As the gatekeepers of the welfare of the animals under their care, farmers are seen as the stakeholder responsible for improving animal welfare. The aim of this study was to explore the knowledge and attitudes of pig farmers towards pig welfare and the impact of such attitudes on farmers' selection of management strategies on the farm. We conducted in-depth semi-structured interviews with 44 pig farmers in one of the main pig producing regions of Brazil. Interviews covered knowledge and attitudes towards pig sentience and behaviour and welfare-related issues commonly observed in intensive pig farms (belly-nosing, fights, tail-biting, diarrhoea and castration without pain control) and farmers' conception and attitudes towards pig welfare. We identified many management and animal-based indicators of poor welfare, such as the use of painful and stressful management practices and use of environments that limit the expression of natural behaviours. However, most farmers were satisfied with animal welfare standards at their farms. Farmers' perceptions are aligned with their understanding of animal welfare. Although they identified all the dimensions that impact the welfare of a pig on a farm (affect, biological functioning and naturalness), their social reality, industry demands and available advice pushed them to perceive their range of action limited to biological and environmental aspects of the animals that do not necessarily benefit affective state. This precluded farmers from making associations between good health and the animal's ability to express a full behavioural repertoire, as well as from viewing abnormal behaviours as problems. The negative consequences for the welfare of the animals were commonly alleviated by routines that relied on constant use of medication, including high dependence on antibiotics. Expressions of estrangement from the production chain were common voices among the participants. This suggests that farmers may not be sufficiently informed or engaged in responding to consumers' expectations and commitments made by companies, which can pose a severe economic risk for farmers. The findings of this study indicate that economic, technical and social factors restrict farmers' autonomy and their ability to perform their role as stewards of animal welfare. (Re)connecting different human, animal and environmental interests may be a step to changing this scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
7. Vascular endothelial growth factor protects motoneurons from serum deprivation–induced cell death through phosphatidylinositol 3-kinase-mediated p38 mitogen-activated protein kinase inhibition
- Author
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Tolosa, L., Mir, M., Olmos, G., and Lladó, J.
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VASCULAR endothelial growth factors , *MOTOR neurons , *CELL death , *MITOGEN-activated protein kinases , *AMYOTROPHIC lateral sclerosis , *ENZYME inhibitors , *SPINAL cord abnormalities , *BRAIN stem abnormalities - Abstract
Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective degeneration and death of motoneurons in the spinal cord, brainstem and motor cortex which causes progressive muscle weakness and paralysis. Although the molecular mechanisms causing the disease remain unknown, excitotoxicity and loss of trophic support have been proposed as causes of degeneration. The present study was designed to elucidate the mechanisms of motoneuron death induced by serum deprivation and the potential neuroprotective effects of vascular endothelial growth factor (VEGF) in dissociated and organotypic rat spinal cord cultures. Serum withdrawal induced apoptotic cell death in dissociated spinal cord cultures, which was prevented in the presence of VEGF. In organotypic spinal cord cultures, low serum-induced motoneuron death was mediated by the stress-related kinase p38 mitogen-activated protein kinase (p38MAPK), as it was reversed by the p38MAPK inhibitor SB203580. In these cultures, exposure to VEGF blocked p38MAPK phosphorylation and prevented the demise of motoneurons. These effects of VEGF were mediated through the phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) signal transduction pathway, as they were blocked in the presence of the PI3-K inhibitor LY294002. In addition, serum deprivation induced down-regulation of the anti-apoptotic protein Bcl-2 and this effect was prevented both by SB203580 and by VEGF via the PI3-K/Akt pathway. Therefore, Bcl-2 could also play an important role in the neuroprotection induced by VEGF in spinal cord cultures. Together, these findings indicate that VEGF prevents motoneuron death induced by serum deprivation blocking the activity of p38MAPK via the PI3-K/Akt signaling pathway. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
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8. Integrin-linked kinase mediates the hydrogen peroxide-dependent transforming growth factor-β1 up-regulation.
- Author
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Gonzalez-Ramos, M., de Frutos, S., Griera, M., Luengo, A., Olmos, G., Rodriguez-Puyol, D., Calleros, L., and Rodriguez-Puyol, M.
- Subjects
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INTEGRIN-linked kinase , *HYDROGEN peroxide , *TRANSFORMING growth factors-beta , *EXTRACELLULAR matrix proteins , *RENAL fibrosis , *GLUCOSE oxidase - Abstract
Abstract: Transforming growth factor type-β1 (TGF-β1) has been recognized as a central mediator in many pathological events related to extracellular matrix (ECM) proteins accumulation, where their locally increased expression has been implicated in the fibrosis process of numerous organs, including glomerular fibrosis in the kidney. We and others have reported the TGF-β1 synthesis regulation by reactive oxygen species (ROS), and moreover we also described the implication of integrin-linked kinase (ILK) in the AP-1-dependent TGF-β1 up-regulation. Thus, we propose here that hydrogen peroxide (H2O2)-dependent TGF-β1 regulation may be mediated by ILK activation. First we confirmed the increase in TGF-β1 expression in human mesangial cells (HMC) after treatment with H2O2 or with an alternative H2O2-generating system such as the glucose-oxidase enzyme (GOX). By using immunoblotting, immunofluorescence, and ELISA techniques, we demonstrate that extracellular H2O2 up-regulates TGF-β1 transcription, as well as increases TGF-β1 promoter activity. Furthermore, catalase-decreased intracellular H2O2 abolished TGF-β1 up-regulation. The use of pharmacological inhibitors as well as knockdown of ILK with small interfering RNA (siRNA) demonstrated the implication of a PI3K/ILK/AKT/ERK MAPK signaling pathway axis in the H2O2-induced TGF-β1 overexpression. Finally, we explored the physiological relevance of these findings by treating HMC with angiotensin II, a known stimuli of H2O2 synthesis. Our results confirm the relevance of previous findings after a more physiological stimulus. In summary, our results provide evidence that ILK activity changes may act as a mechanism in response to different stimuli such as H2O2 in the induced TGF-β1 up-regulation in pathological or even physiological conditions. [Copyright &y& Elsevier]
- Published
- 2013
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9. Tumor necrosis factor alpha and interferon gamma cooperatively induce oxidative stress and motoneuron death in rat spinal cord embryonic explants
- Author
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Mir, M., Asensio, V.J., Tolosa, L., Gou-Fabregas, M., Soler, R.M., Lladó, J., and Olmos, G.
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TUMOR necrosis factors , *INTERFERONS , *OXIDATIVE stress , *MOTOR neurons , *CELL death , *LABORATORY rats , *SPINAL cord , *NEURODEGENERATION , *AMYOTROPHIC lateral sclerosis - Abstract
Abstract: The accumulation of reactive microglia in the degenerating areas of amyotrophic lateral sclerosis (ALS) tissue is a key cellular event creating a chronic inflammatory environment that results in motoneuron death. We have developed a new culture system that consists in rat spinal cord embryonic explants in which motoneurons migrate outside the explant, growing as a monolayer in the presence of glial cells. The proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) have been proposed to be involved in ALS-linked microglial activation. In our explants, the combined exposure to these cytokines resulted in an increased expression of the pro-oxidative enzymes inducible nitric oxide synthase (iNOS), the catalytic subunit of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, gp91phox and cyclooxygenase-2 (COX-2), as compared to each cytokine alone. This effect was related to their cooperation in the activation of the transcription factor nuclear factor kappa B (NF-κB). TNF-α and IFN-γ also cooperated to promote protein oxidation and nitration, thus increasing the percentage of motoneurons immunoreactive for nitrotyrosine. Apoptotic motoneuron death, measured through annexin V-Cy3 and active caspase-3 immunoreactivities, was also found cooperatively induced by TNF-α and IFN-γ. Interestingly, these cytokines did not affect the viability of purified spinal cord motoneurons in the absence of glial cells. It is proposed that the proinflammatory cytokines TNF-α and IFN-γ have cooperative/complementary roles in inflammation-induced motoneuron death. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
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10. μ-opioid receptor activation prevents apoptosis following serum withdrawal in differentiated SH-SY5Y cells and cortical neurons via phosphatidylinositol 3-kinase
- Author
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Iglesias, M., Segura, M.F., Comella, J.X., and Olmos, G.
- Subjects
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OPIOID receptors , *APOPTOSIS - Abstract
Opioid peptides and alkaloids exert their effects via G protein-coupled receptors (GPCRs). It has been shown that, in addition to trophic factors, some GPCRs are able to activate the phosphatidylinositol 3-kinase/Akt (PI 3-K/Akt) signal transduction pathway, thus leading to cell survival. The aim of this study was to test whether activation of μ-opioid receptors has protective effects on serum withdrawal-induced cell death and to study the possible implication of PI 3-K in this process. In SH-SY5Y neuroblastoma cells fully differentiated by exposure to retinoic acid for five days, the enkephalin derivative selective μ-agonist DAMGO (0.1–2 μM) and the alkaloid morphine (0.1–10 μM) promoted cell survival after serum deprivation (MTT and trypan blue exclusion assays), without inducing cell proliferation. These effects were fully reversed by naloxone, by the selective μ-antagonist β-funaltrexamine (β-FNA) and also by the specific PI 3-K inhibitor LY294002. The two agonists stimulated Akt phosphorylation and the effect was also abolished by β-FNA and by LY294002. In mouse primary cortical neurons, DAMGO reduced the percentage of apoptosis after 6, 12, 24 and 48 h of serum withdrawal; as determined by Hoechst staining. This effect was blocked by β-FNA, by pre-treatment with pertussis toxin and by LY294002. DAMGO also stimulated Akt phosphorylation via PI 3-K in this primary neuronal culture. Together, these results indicate that stimulation of the μ-opioid receptor promotes neuronal survival in a Gi/o-linked, PI 3-K-dependent signaling cascade and suggest that Akt may be a key downstream kinase involved in this anti-apoptotic effect. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
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