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- Anzabi, M., et al.
(författare)
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Hippocampal Atrophy Following Subarachnoid Hemorrhage Correlates with Disruption of Astrocyte Morphology and Capillary Coverage by AQP4
- 2018
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Ingår i: Frontiers in Cellular Neuroscience. - : Frontiers Media SA. - 1662-5102. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Despite successful management of ruptured intracranial aneurysm following subarachnoid hemorrhage (SAH), delayed cerebral ischemia (DCI) remains the main cause of high mortality and morbidity in patients who survive the initial bleeding. Astrocytes play a key role in neurovascular coupling. Therefore, changes in the neurovascular unit including astrocytes following SAH may contribute to the development of DCI and long-term complications. In this study, we characterized morphological changes in hippocampal astrocytes following experimental SAH, with special emphasis on glia-vascular cross-talk and hippocampal volume changes. Four days after induction of SAH or sham-operation in mice, their hippocampal volumes were determined by magnetic resonance imaging (MRI) and histological/stereological methods. Glial fibrillary acid protein (GFAP) immunostained hippocampal sections were examined by stereological techniques to detect differences in astrocyte morphology, and global spatial sampling method was used to quantify the length density of Aquaporin-4 (AQP4) positive capillaries. Our results indicated that hippocampal volume, as measured both by MRI and by histological approaches, was significantly lower in SAH animals than in the sham-operated group. Accordingly, in this animal model of SAH, hippocampal atrophy existed already at the time of DCI onset in humans. SAH induced retraction of GFAP positive astrocyte processes, accompanied by a significant reduction in the length density of AQP4 positive capillaries as well as narrowing of hippocampal capillaries. Meanwhile, astrocyte volume was higher in SAH mice compared with the sham-operated group. Morphological changes in hippocampal astrocytes seemingly disrupt glia-vascular interactions early after SAH and may contribute to hippocampal atrophy. We speculate that astrocytes and astrocyte-capillary interactions may provide targets for the development of therapies to improve the prognosis of SAH.
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- Ardalan, A., et al.
(författare)
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Post-disaster quality of life among older survivors five years after the Bam earthquake : implications for recovery policy
- 2011
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Ingår i: Ageing & Society. - 0144-686X .- 1469-1779. ; 31:2, s. 179-196
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Tidskriftsartikel (refereegranskat)abstract
- Older people are among the most vulnerable in major disasters. In their aftermath, it is crucial to institute efforts that will maintain a high level of elders' quality of life (QoL). This paper presents QoL assessments of elderly survivors five years after the Bam earthquake in Iran, and evaluates the determinants. A cross-sectional analysis of 210 randomly-selected survivors was carried out in 2008 using the WHOQOL-BREF questionnaire. A comparison of the results with data on the general population showed that experiencing the earthquake may adversely affect psychological dimensions of QoL even five years after, but paradoxically the earthquake resulted in better social relationships in affected communities than in the general population. Lower QoL associated with female gender, higher age, living alone, severe earthquake-related injury, poor quality of living conditions, increased dependency in the activities of daily living, living in an urban area, and being temporarily housed. Recovery experts and donors should carry out long-term monitoring of health status and QoL in disaster-affected communities, with a focus on psychological wellbeing. Intervention programmes that emphasise post-disaster quality of care and satisfactory housing may lead to better QoL of the victims and may shorten the recovery phase.
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- Bay, V., et al.
(författare)
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Flinders sensitive line rats are resistant to infarction following transient occlusion of the middle cerebral artery
- 2020
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Ingår i: Brain Research. - : Elsevier BV. - 0006-8993. ; 1737
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Tidskriftsartikel (refereegranskat)abstract
- Background: Depression is a common complication of stroke and increases the risk of mortality and disability. Pre-stroke depression is a possible risk factor for stroke and has also been linked to adverse outcomes. The underlying mechanisms linking depression and stroke remain unclear. Preclinical models may provide novel insights, but models reflecting both conditions are lacking. Methods: In this study, we investigated the effects of a 45-min transient middle cerebral artery occlusion (MCAo) on infarct size in male adult Flinders Sensitive Line rats, a genetic animal model of depression, and their control strains Flinders Resistant Line and Sprague-Dawley rats. Infarct size was assessed by tetrazolium chloride (TTC) and microtubule-associated protein 2 (MAP2) staining after 48 h of reperfusion. Angiograms of the vascular structure of naive animals were produced with a mu-CT scanner. Results: Both Flinders strains had significantly smaller infarcts following MCAo compared to Sprague-Dawley rats. This effect does not appear to be due to changes in cerebrovascular architecture, as indicated by an initial exploration of vascular organization using angiograms, or body temperature regulation. Conclusions: Our study suggests that the rat strain does not influence infarct volumes following MCAo.
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- Bay, Vibeke, et al.
(författare)
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Tissue processing and optimal visualization of cerebral infarcts following sub-acute focal ischemia in rats
- 2021
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Ingår i: Journal of Chemical Neuroanatomy. - : Elsevier BV. - 0891-0618 .- 1873-6300. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- Transient cerebral ischemia followed by reperfusion in an infarcted brain comes with predictable acute and chronic morphological alterations in neuronal and non-neuronal cells. An accurate delineation of the cerebral infarct is not a simple task due to the complex shapes and indistinct borders of the infarction. Thus, an exact macroscopic histological approach for infarct volume estimation can lead to faster and more reliable preclinical research results. This study investigated the effect(s) of confounding factors such as fixation and tissue embedding on the quality of macroscopic visualization of focal cerebral ischemia by anti-microtubule-associated-protein-2 antibody (MAP2) with conventional Hematoxylin and Eosin (HE) staining serving as the control. The aim was to specify the most reliable macroscopic infarct size estimation method after sub-acute focal cerebral ischemia based on the qualitative investigation. Our results showed that the ischemic area on the MAP2-stained sections could be identified macroscopically on both cryo-preserved and paraffin-embedded sections from both immersion- and perfusion-fixed brains. The HE staining did not clearly depict an infarct area for macroscopic visualization. Therefore both immersion-fixed and perfused-fixed-MAP2 stained sections can be used reliably to quantify cerebral infarcts.
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- Chumak, Tetyana, 1982, et al.
(författare)
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Maternal n-3 Polyunsaturated Fatty Acid Enriched Diet Commands Fatty Acid Composition in Postnatal Brain and Protects from Neonatal Arterial Focal Stroke
- 2022
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Ingår i: Translational Stroke Research. - : Springer Science and Business Media LLC. - 1868-4483 .- 1868-601X. ; 13:3, s. 449-461
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Tidskriftsartikel (refereegranskat)abstract
- The fetus is strongly dependent on nutrients from the mother, including polyunsaturated fatty acids (PUFA). In adult animals, n-3 PUFA ameliorates stroke-mediated brain injury, but the modulatory effects of different PUFA content in maternal diet on focal arterial stroke in neonates are unknown. This study explored effects of maternal n-3 or n-6 enriched PUFA diets on neonatal stroke outcomes. Pregnant mice were assigned three isocaloric diets until offspring reached postnatal day (P) 10-13: standard, long-chain n-3 PUFA (n-3) or n-6 PUFA (n-6) enriched. Fatty acid profiles in plasma and brain of mothers and pups were determined by gas chromatography-mass spectrometry and cytokines/chemokines by multiplex protein analysis. Transient middle cerebral artery occlusion (tMCAO) was induced in P9-10 pups and cytokine and chemokine accumulation, caspase-3 and calpain-dependent spectrin cleavage and brain infarct volume were analyzed. The n-3 diet uniquely altered brain lipid profile in naive pups. In contrast, cytokine and chemokine levels did not differ between n-3 and n-6 diet in naive pups. tMCAO triggered accumulation of inflammatory cytokines and caspase-3-dependent and -independent cell death in ischemic-reperfused regions in pups regardless of diet, but magnitude of neuroinflammation and caspase-3 activation were attenuated in pups on n-3 diet, leading to protection against neonatal stroke. In conclusion, maternal/postnatal n-3 enriched diet markedly rearranges neonatal brain lipid composition and modulates the response to ischemia. While standard diet is sufficient to maintain low levels of inflammatory cytokines and chemokines under physiological conditions, n-3 PUFA enriched diet, but not standard diet, attenuates increases of inflammatory cytokines and chemokines in ischemic-reperfused regions and protects from neonatal stroke.
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- Gravina, Giacomo, et al.
(författare)
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Proteomics identifies lipocalin-2 in neonatal inflammation associated with cerebrovascular alteration in mice and preterm infants
- 2023
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Ingår i: iScience. - 2589-0042. ; 26:7
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus (S.) epidermidis is the most common nosocomial coagulase-negative staphylococci infection in preterm infants. Clinical signs of infection are often unspecific and novel markers to complement diagnosis are needed. We investigated proteomic alterations in mouse brain after S. epidermidis infection and in preterm infant blood. We identified lipocalin-2 (LCN2) as a crucial protein associated with cerebrovascular changes and astrocyte reactivity in mice. We further proved that LCN2 protein expression was associated with endothelial cells but not astrocyte reactivity. By combining network analysis and differential expression approaches, we identified LCN2 linked to blood C-reactive protein levels in pre term infants born <28 weeks of gestation. Blood LCN2 levels were associated with similar alterations of cytokines and chemokines in both infected mice and human preterm infants with increased levels of C-reactive protein. This experimental and clinical study suggests that LCN2 may be a marker of preterm infection/inflammation associated with cerebrovascular changes and neuroinflammation.
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- Jouybari, Arash, et al.
(författare)
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Methods comparison for attitude determination of a lightweight buoy by raw data of IMU
- 2019
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Ingår i: Measurement. - : Elsevier. - 0263-2241 .- 1873-412X. ; 135, s. 348-354
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Tidskriftsartikel (refereegranskat)abstract
- Today, one of the most important issues is the determination of instantaneous sea level and distinguishing the Tsunami by floating buoy in the ocean. Usually, gyroscopes are used to measure the angular velocity of a buoy. On the other hand, considering the advancement of various technologies in the field of precise accelerometers, make it possible to use these kinds of sensors for navigation purpose. In this research, stable and optimal methods for determining the orientation of a moving buoy is presented using a combination of the gyroscope, accelerometers, and magnetic sensors data. In order to prove the effectiveness of the proposed methods, the raw data were collected from accelerometers, gyroscopes, and magnetometers of (Xsens MTI-G-700) mounted on a Buoy in coastal waters of Kish Island, Iran. Then, by using the proposed methods, the Euler angles of the buoy are determined, while the Euler angles are derived from the Xsens sensor we are considered as a reference. Based on the results, RMSD for Madgwick algorithm are 0.57° 0.37° and 0.50° for Mahony algorithm are 0.56° 0.37° and 0.50° and finally for Complementary algorithm is 0.63° 0.26° and 2.38° which these values are for roll, pitch, and yaw angles respectively. Thus Mahony algorithm for determining roll and yaw Euler angles is more accurate than other algorithms; however, this differences is negligible compared to the Madgwick algorithm. The Complementary algorithm is less accurate than the other two algorithms, especially for determining the yaw angle of the buoy.
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