| 1. |
- Chalkias, Helena, et al.
(författare)
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Identification of novel candidate genes for the inverted teat defect in sows using a genome-wide marker panel
- 2017
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Ingår i: Journal of Applied Genetics. - : Springer Science and Business Media LLC. - 1234-1983 .- 2190-3883. ; 58, s. 249-259
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Tidskriftsartikel (refereegranskat)abstract
- The number of functional teats is an important selection criterion in pig breeding. Inherited defects of the udder, such as the inverted teat, do have a considerable negative impact on the nursing ability of the sow. To investigate the genetic background of this defect and the number of functional teats in Swedish maternal lines, samples from 230 Yorkshire pigs were selected for genotyping using the PorcineSNP60K BeadChip (Illumina Inc.), each pig with at least one inverted teat was matched with one non-affected pig (fullsib or pairs with matching herd and gender). A genome-wide association study on these 230 pigs was performed using the two-step approach implemented in GenABEL using 46,652 single nucleotide polymorphisms across all autosomes and the X chromosome. A number of significant regions were identified for the inverted teat defect on chromosomes 2, 10, and 18. Many of the regions associated with the number of functional teats were located in the same or close regions, except two associated markers on the X chromosome and one on chromosome 3. We identified some of the regions on chromosomes previously reported in one linkage and one gene expression study. We conclude, despite being able to suggest new candidate genes, that further studies are needed to better understand the biologic background of the teat development. Despite the in-depth comparison of identified regions for the inverted teat defect done here, more studies are required to allow a clear identification of genetic regions relevant for this defect across many pig populations.
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| 2. |
- Jinnai, Masako, et al.
(författare)
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A Model of Germinal Matrix Hemorrhage in Preterm Rat Pups.
- 2020
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Ingår i: Frontiers in cellular neuroscience. - : Frontiers Media SA. - 1662-5102. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Germinal matrix hemorrhage (GMH) is a serious complication in extremely preterm infants associated with neurological deficits and mortality. The purpose of the present study was to develop and characterize a grade III and IV GMH model in postnatal day 5 (P5) rats, the equivalent of preterm human brain maturation. P5 Wistar rats were exposed to unilateral GMH through intracranial injection into the striatum close to the germinal matrix with 0.1, 0.2, or 0.3 U of collagenase VII. During 10 days following GMH induction, motor functions and body weight were assessed and brain tissue collected at P16. Animals were tested for anxiety, motor coordination and motor asymmetry on P22-26 and P36-40. Using immunohistochemical staining and neuropathological scoring we found that a collagenase dose of 0.3 U induced GMH. Neuropathological assessment revealed that the brain injury in the collagenase group was characterized by dilation of the ipsilateral ventricle combined with mild to severe cellular necrosis as well as mild to moderate atrophy at the levels of striatum and subcortical white matter, and to a lesser extent, hippocampus and cortex. Within 0.5 h post-collagenase injection there was clear bleeding at the site of injury, with progressive increase in iron and infiltration of neutrophils in the first 24 h, together with focal microglia activation. By P16, blood was no longer observed, although significant gray and white matter brain infarction persisted. Astrogliosis was also detected at this time-point. Animals exposed to GMH performed worse than controls in the negative geotaxis test and also opened their eyes with latency compared to control animals. At P40, GMH rats spent more time in the center of open field box and moved at higher speed compared to the controls, and continued to show ipsilateral injury in striatum and subcortical white matter. We have established a P5 rat model of collagenase-induced GMH for the study of preterm brain injury. Our results show that P5 rat pups exposed to GMH develop moderate brain injury affecting both gray and white matter associated with delayed eye opening and abnormal motor functions. These animals develop hyperactivity and show reduced anxiety in the juvenile stage.
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| 3. |
- Jonas, Elisabeth, et al.
(författare)
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Studies of the Genetic Background of a Teat Defect in Pigs Born in Germany and Sweden
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- To improve the understanding of the genetics underlying the inverted teat defect in pigs, we combined studies from Germany and Sweden. Based on a linkage study in Germany which revealed highly significant loci in an experimental population, confirmation of regions was attempted using commercial animals. A genome-wide association study on commercial pigs was also conducted in Sweden. Since both datasets of commercial pigs had a relatively low number of samples, we tested if microsatellite and data of SNP arrays have, in a combined analysis, enough power to validate loci with a higher reliability. We combined microsatellite data and haplotypes and verified associated alleles on chromosomes 1, 4, 6, 11, 14 and 18. Approaches like these present an opportunity to re-use old datasets and to increase the power of recent association studies when samples or further funding are not available.
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| 4. |
- Koning, Gabriella, et al.
(författare)
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Magnesium induces preconditioning of the neonatal brain via profound mitochondrial protection.
- 2019
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Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 39:6, s. 1038-1055
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Tidskriftsartikel (refereegranskat)abstract
- Magnesium sulphate (MgSO4) given to women in preterm labor reduces cerebral palsy in their offspring but the mechanism behind this protection is unclear, limiting its effective, safe clinical implementation. Previous studies suggest that MgSO4 is not neuroprotective if administered during or after the insult, so we hypothesised that MgSO4 induces preconditioning in the immature brain. Therefore, we administered MgSO4 at various time-points before/after unilateral hypoxia-ischemia (HI) in seven-day-old rats. We found that MgSO4 treatment administered as a bolus between 6 days and 12h prior to HI markedly reduced the brain injury, with maximal protection achieved by 1.1mg/g MgSO4 administered 24h before HI. As serum magnesium levels returned to baseline before the induction of HI, we ascribed this reduction in brain injury to preconditioning. Cerebral blood flow was unaffected, but mRNAs/miRNAs involved in mitochondrial function and metabolism were modulated by MgSO4. Metabolomic analysis (H+-NMR) disclosed that MgSO4 attenuated HI-induced increases in succinate and prevented depletion of high-energy phosphates. MgSO4 pretreatment preserved mitochondrial respiration, reducing ROS production and inflammation after HI. Therefore, we propose that MgSO4 evokes preconditioning via induction of mitochondrial resistance and attenuation of inflammation.
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| 5. |
- Koning, Gabriella, et al.
(författare)
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Magnesium sulphate induces preconditioning in preterm rodent models of cerebral hypoxia-ischemia.
- 2018
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Ingår i: International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience. - : Wiley. - 1873-474X. ; 70, s. 56-66
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Tidskriftsartikel (refereegranskat)abstract
- Brain injury in preterm infants represents a substantial clinical problem associated with development of motor impairment, cognitive deficits and psychiatric problems. According to clinical studies, magnesium sulphate (MgSO4) given to women in preterm labor reduces the risk of cerebral palsy in the offspring but the mechanisms behind its neuroprotective effects are still unclear. Our aim was to explore whether MgSO4 induces tolerance (preconditioning) in the preterm rodent brain. For this purpose we established a model of perinatal hypoxia-ischemia (HI) in postnatal day 4 rats and also applied a recently developed postnatal day 5 mouse model of perinatal brain injury.Postnatal day 4 Wistar rats were exposed to unilateral carotid artery ligation followed by 60, 70 or 80min of hypoxia (8% O2). On postnatal day 11, brains were collected and macroscopically visible damage as well as white and grey matter injury was examined using immunohistochemical staining. Once the model had been established, a possible preconditioning protection induced by a bolus MgSO4 injection prior to 80min HI was examined 7days after the insult. Next, a MgSO4 bolus was injected in C57Bl6 mice on PND 4 followed by exposure to unilateral carotid artery ligation and hypoxia, (10% O2) for 70min on PND 5. Brains were collected 7days after the insult and examined with immunohistochemistry for grey and white matter injury.In rats, a 60min period of hypoxia resulted in very few animals with brain injury and although 70min of hypoxia resulted in a higher percentage of injured animals, the brains were marginally damaged. An 80min exposure of hypoxia caused cortical tissue damage combined with hippocampal atrophy and neuronal loss in the C3 hippocampal layer. In the rat model, MgSO4 (1.1mg/g administered i.p. 24h prior to the induction of HI, resulting in a transient serum Mg2+ concentration elevation to 4.1±0.2mmol/l at 3h post i.p. injection) reduced brain injury by 74% in grey matter and 64% in white matter. In the mouse model, MgSO4 (0.92mg/g) i.p. injection given 24h prior to the HI insult resulted in a Mg2+ serum concentration increase reaching 2.7±0.3mmol/l at 3h post injection, which conferred a 40% reduction in grey matter injury.We have established a postnatal day 4 rat model of HI for the study of preterm brain injury. MgSO4 provides a marked preconditioning protection both in postnatal day 4 rats and in postnatal day 5 mice.
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