| 1. |
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| 2. |
- Barbu, M., et al.
(författare)
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Sclerosing Aortic and Coronary Arteritis Due to IgG4-Related Disease
- 2017
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Ingår i: Annals of Thoracic Surgery. - : Elsevier BV. - 0003-4975. ; 103:6
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Tidskriftsartikel (refereegranskat)abstract
- We present the case of a 55-year-old woman admitted for a coronary artery bypass operation because of three-vessel coronary artery disease based on angiographic findings and clinical symptoms. Unexpected intraoperative findings with diffuse tissue thickening of the ascending aorta and coronary arteries indicated an alternate pathogenesis rather than coronary artery atherosclerosis. Histopathologic findings and clinical evaluation could confirm IgG4-related disease (IgG4-RD). IgG4-RD is a newly recognized fibroinflammatory condition that can present in a variety of organs and is characterized by common histopathologic features. Low disease awareness among clinicians makes this condition underdiagnosed. © 2017 The Society of Thoracic Surgeons
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| 3. |
- Brachi, B., et al.
(författare)
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Plant genetic effects on microbial hubs impact host fitness in repeated field trials
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:30
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Tidskriftsartikel (refereegranskat)abstract
- Although complex interactions between hosts and microbial associates are increasingly well documented, we still know little about how and why hosts shape microbial communities in nature. In addition, host genetic effects on microbial communities vary widely depending on the environment, obscuring conclusions about which microbes are impacted and which plant functions are important. We characterized the leaf microbiota of 200 Arabidopsis thaliana genotypes in eight field experiments and detected consistent host effects on specific, broadly distributed microbial species (operational taxonomic unit [OTUs]). Host genetic effects disproportionately influenced central ecological hubs, with heritability of particular OTUs declining with their distance from the nearest hub within the microbial network. These host effects could reflect either OTUs preferentially associating with specific genotypes or differential microbial success within them. Host genetics associated with microbial hubs explained over 10% of the variation in lifetime seed production among host genotypes across sites and years. We successfully cultured one of these microbial hubs and demonstrated its growth-promoting effects on plants in sterile conditions. Finally, genome-wide association mapping identified many putatively causal genes with small effects on the relative abundance of microbial hubs across sites and years, and these genes were enriched for those involved in the synthesis of specialized metabolites, auxins, and the immune system. Using untargeted metabolomics, we corroborate the consistent association between variation in specialized metabolites and microbial hubs across field sites. Together, our results reveal that host genetic variation impacts the microbial communities in consistent ways across environments and that these effects contribute to fitness variation among host genotypes.
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| 4. |
- Carlander, Johan, et al.
(författare)
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Heat Production, Nerve Function, and Morphology following Nerve Close Dissection with Surgical Instruments
- 2012
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Ingår i: World Journal of Surgery. - : Springer Verlag (Germany). - 0364-2313 .- 1432-2323. ; 36:6, s. 1361-1367
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare an ultrasonically activated instrument (US), monopolar electrosurgery, and bipolar electrosurgery (ES) with respect to heat production, nerve function, and nerve morphology following in vivo application. less thanbrgreater than less thanbrgreater thanThe biceps femoris muscle of anesthetized rats was cut in a standardized manner longitudinally 1 mm adjacent to the sciatic nerve using US shears, a monopolar ES knife, or a bipolar ES scissors. Activation time and temperature were recorded continuously within 1-4 mm of the activation site ipsilateral and contralateral to the nerve with two thermoelectric microsensors. Temperature rise and time delay of reaching the temperature maximum, as an expression of heat spread within tissue, maximum temperature, and thermal dose (equivalent time of exposure at 43A degrees C) were measured and calculated. A total of 49 functional experiments were conducted. The electromyographic (EMG) potential was recorded distally. Nerve dysfunction was defined as more than 10% loss of the evoked EMG amplitude. Forty-eight nerves were coded and submitted to blind histopathological examination, and morphological damage was graded on a 4-grade scale. less thanbrgreater than less thanbrgreater thanThe maximum temperature elevation and the thermal dose were significantly higher for the bipolar ES compared with the US instrument ( = 0.024, = 0.049), and with much less variation of results for the US instrument. The monopolar ES maximum temperature and thermal dose were lower, but a very large variation occurred, probably as a result of more random electrical spread to the ground electrode and muscle motion artifacts. Functional loss was least common in the US group-without being significant-compared to bipolar and monopolar ES. Moderate and severe morphological damage was significantly less common in the US group than in the monopolar ES group ( = 0.041). We found no statistically significant correlation between the highest temperatures and the degree of morphological damage or functional loss less thanbrgreater than less thanbrgreater thanThe temperature elevation depends strongly on the distance to the activated instrument. The bipolar ES scissors generates a higher maximum temperature and thermal dose with a greater variation in than the US. Functional loss and severe morphological damage were uncommon in all groups.
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| 5. |
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| 6. |
- Nordborg, M, et al.
(författare)
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The pattern of polymorphism in Arabidopsis thaliana
- 2005
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Ingår i: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885. ; 3:7, s. 1289-1299
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Tidskriftsartikel (refereegranskat)abstract
- We resequenced 876 short fragments in a sample of 96 individuals of Arabidopsis thaliana that included stock center accessions as well as a hierarchical sample from natural populations. Although A. thaliana is a selfing weed, the pattern of polymorphism in general agrees with what is expected for a widely distributed, sexually reproducing species. Linkage disequilibrium decays rapidly, within 50 kb. Variation is shared worldwide, although population structure and isolation by distance are evident. The data fail to fit standard neutral models in several ways. There is a genome-wide excess of rare alleles, at least partially due to selection. There is too much variation between genomic regions in the level of polymorphism. The local level of polymorphism is negatively correlated with gene density and positively correlated with segmental duplications. Because the data do not fit theoretical null distributions, attempts to infer natural selection from polymorphism data will require genome-wide surveys of polymorphism in order to identify anomalous regions. Despite this, our data support the utility of A. thaliana as a model for evolutionary functional genomics.
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| 7. |
- Robledo-Abad, Carmenza, et al.
(författare)
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Bioenergy production and sustainable development: science base for policy-making remains limited
- 2017
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Ingår i: Global Change Biology Bioenergy. - : Wiley. - 1757-1693 .- 1757-1707. ; 9:3, s. 541-556
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of using bioenergy as a climate change mitigation measure has sparked a discussion of whether and how bioenergy production contributes to sustainable development. We undertook a systematic review of the scientific literature to illuminate this relationship and found a limited scientific basis for policy-making. Our results indicate that knowledge on the sustainable development impacts of bioenergy production is concentrated in a few well-studied countries, focuses on environmental and economic impacts, and mostly relates to dedicated agricultural biomass plantations. The scope and methodological approaches in studies differ widely and only a small share of the studies sufficiently reports on context and/or baseline conditions, which makes it difficult to get a general understanding of the attribution of impacts. Nevertheless we identified regional patterns of positive or negative impacts for all categories – environmental, economic, institutional, social and technological. In general, economic and technological impacts were more frequently reported as positive, while social and environmental impacts were more frequently reported as negative (with the exception of impacts on direct substitution of GHG emission from fossil fuel). More focused and transparent research is needed to validate these patterns and develop a strong science underpinning for establishing policies and governance agreements that prevent/mitigate negative and promote positive impacts from bioenergy production.
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| 8. |
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| 9. |
- Belichenko, P, et al.
(författare)
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Dendritic morphology in epileptogenic cortex from TRPE patients, revealed by intracellular Lucifer Yellow microinjection and confocal laser scanning microscopy.
- 1994
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Ingår i: Epilepsy research. - 0920-1211. ; 18:3, s. 233-47
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Tidskriftsartikel (refereegranskat)abstract
- Biopsy material was obtained from cortical epileptogenic zones (eight temporal, one occipital, one parietal and one frontal) of eleven patients aged 1.5-47 years with therapy-resistant partial epilepsy (TRPE) undergoing epilepsy surgery. Control autopsy material (two temporal, two occipital, one parietal and one frontal) was removed from six neurologically healthy cases within 6-10 hours postmortem delay. In each specimen, 100-300 pyramidal and non-pyramidal neurons were visualized by intracellular Lucifer Yellow microinjection. Single neurons were imaged using CLSM generated serial optical sections; 2-D reconstruction of each neuron was made using z-projection of serial optical images, and 3-D reconstructions and rotations were computerized. Neuronal maps from TRPE biopsies, compared to control autopsies, show markedly increased numbers of dendritic abnormalities of single pyramidal and non-pyramidal neurons in layers I, II-III, V-VII, and in the subcortical white matter. The abnormalities include: (1) increased number of non-pyramidal cells in layer I; (2) many pyramidal cells with two or three dendrites originating apically, rather than one single apical dendrite, in layers II-III; (3) atypical orientation of oblique apical and basal dendrites in pyramidal neurons of layers II-VII; (4) increased number of atypical 'dinosaur-like' and fusiform cells in layers V-VII; (5) numerous neurons in the white matter. These abnormalities may be etiological in cases with early onset, and predisposing in cases with late onset.
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| 10. |
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| 11. |
- Cottino, A, et al.
(författare)
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Die Schwedische Rechtshilfereform
- 1978
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Ingår i: Rechtsbedürfnis und Rechtshilfe. - Opladen : Westdeutscher Verlag. - 3531114506 ; , s. 162-174
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 12. |
- Fredriksson, K, et al.
(författare)
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Cerebral microangiopathy in stroke-prone spontaneously hypertensive rats. An immunohistochemical and ultrastructural study
- 1988
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 75:3, s. 241-252
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Tidskriftsartikel (refereegranskat)abstract
- The morphology of cerebral microvessels was studied immunohistochemically and ultrastructurally in 6- to 9-month-old normotensive Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and stroke-prone SHR (SHRSP) with a systolic blood pressure of 138 +/- 15 mm Hg, 189 +/- 9 mm Hg, and 258 +/- 30 mm Hg respectively. Regions with major opening of the blood-brain barrier (BBB) were revealed by an i.v. injection of Evans Blue. Multifocal BBB opening with massive leakage of plasma constituents rich in fibrinogen-fibrin-related antigen occurred in SHRSP with a blood pressure above 210-220 mm Hg. BBB-leakage sites were found in the cerebral cortex and the basal ganglia, most frequently in the arterial border zones. The perivascular tissue spaces were dilated within the BBB-leakage sites, in particular around arterioles. Damaged endothelial and smooth muscle cells were replaced by fibrin-like material, multiple layers of basement membranes and bundles of collagen fibrils surrounded by proliferated fibroblasts. The degenerative-infiltrative-proliferative disease process transformed short segments of single arterioles into severely thickened, tortuous and stenotic vessels. Fibrinoid degeneration, formation of microaneurysms and fibrin-rich vascular occlusions were observed. In contrast, only minor or no vascular alterations were seen in regions with preserved BBB in SHRSP and SHR. A severely increased intraluminal pressure load appears to be of major pathogenetic importance for breakdown of the BBB and initiation of the vascular disease process in SHRSP. However, since only short segments of a limited number of widely separated vessels are severely affected, and the number of affected vessels increase towards arterial end and border zones, additional predisposing and aggravating factors may play significant roles in the development of fibrinoid vascular lesions in arterial hypertension.
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| 13. |
- Fredriksson, K, et al.
(författare)
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Cerebrovascular lesions in stroke-prone spontaneously hypertensive rats
- 1985
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 68:4, s. 284-294
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Tidskriftsartikel (refereegranskat)abstract
- The cerebrovascular lesions of severe chronic hypertension were studied by light microscopy in perfusion-fixed, subserially sectioned brains from stroke-prone spontaneously hypertensive rats (SHRSP). The leakage and spread of plasma proteins were visualized by immunohistochemical detection of extravasated fibrinogen and by using an exogenous marker (Evans blue injected i.v.) for blood-brain barrier (BBB) dysfunction. In most SHRSP the hypertension did not lead to major BBB lesions in spite of a mean arterial pressure around 200 mm Hg at 6-9 months of age. Multifocal BBB damage occurred in a minor group of SHRSP, particularly within the cortex and the deep gray matter. A close spatial correlation was found between the leakage-spread of plasma constituents and the neuropathologic alterations. Fibrinoid degeneration of penetrating arterioles was found within the leakage sites. The surrounding gray matter showed petechial hemorrhages and abundant proteinaceous exudates rich in antifibrinogen-positive material. The current leakage of Evans blue and wide spread of fibrinoid substances suggested long-lasting damage to the BBB. Most neurons within the edematous gray matter had well preserved nuclei surrounded by a rim of cytoplasm with ill-defined outline as if vacuolation or lysis of the peripheral cytoplasm had occurred. The sponginess of the tissue progressed in severe cases to formation of necrotic cysts. Condensed acidophilic neurons were seen in the border zone between the edematous and more compact gray matter. The appearance and distribution of the gray matter lesions deviated in many respects from those commonly seen in regional ischemic infarcts. The fibrin thrombi found close to the cysts might be regarded as secondary events. The extensive spread of antifibrinogen-positive material within the white matter seemed to originate mainly from the chronic leakage sites in the gray matter. Increased number of large astrocytes were seen within the leakage sites and along the spreading pathways for the edema constituents. The white matter showed a rarefied texture with widely dispersed nerve fiber tracts, volume expansion, and occasional cyst formation. The results indicate a crucial pathophysiologic role for the egress, spread, and accumulation of vasogenic edema in the development of the cerebrovascular lesions in SHRSP.
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| 14. |
- Fredriksson, K, et al.
(författare)
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Cyst formation and glial response in the brain lesions of stroke-prone spontaneously hypertensive rats
- 1988
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 76:5, s. 441-450
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Tidskriftsartikel (refereegranskat)abstract
- The brain lesions in spontaneously hypertensive stroke-prone rats (SHRSP) are characterised by multifocal microvascular damage, breakdown of the blood-brain barrier, massive extravasation of plasma constituents and severe brain oedema, with consequent spongy and cystic tissue destruction in the cerebral cortex and basal ganglia as well as loosening of the white matter. In this paper we analyse in greater detail the pathogenetic mechanisms by which the spongy and cystic lesions are formed and the response of astrocytic cells. For this purpose, tracer (Evans blue)-stained brain lesions were examined in 8-month-old SHRSP immunohistochemically and electron microscopically. Sponginess of the neuropil in small lesions and at the periphery of larger lesions was due to swollen neuronal and astrocytic cell processes, i.e. at this stage the oedema was mainly intracellular. Cystic lesions were formed in the grey matter both by expansion of the extracellular space (ECS) containing protein-rich oedema fluid, and by rupture and subsequent loss of massively swollen cellular elements. In the white matter small slit-formed cysts along the fibre tracts were also formed by the expansion of ECS. In apparently recent lesions astrocytes displayed cyto-plasmic oedema but otherwise were still fairly normal. In more chronic lesions increased numbers of enlarged astrocytes with prominent staining for glial fibrillary acidic protein were present. Their distribution corresponded well to the spread of oedema, i.e. they were prominent around the leaky vessels in the grey matter, in the subpial zone and in the white matter. In the reparative phase the grey matter cysts became lined by astrocytic processes, a new glia limitans. Profuse sheets of glial processes in the neuropil around the cysts reestablished the compactness of the brain parenchyma.
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| 15. |
- Fredriksson, K, et al.
(författare)
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Nerve cell injury in the brain of stroke-prone spontaneously hypertensive rats
- 1988
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 76:3, s. 227-237
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Tidskriftsartikel (refereegranskat)abstract
- The brain lesions in stroke-prone spontaneously hypertensive rats (SHRSP) are characterized by multifocal microvascular and spongy-cystic parenchymal alterations particularly in the gray matter. An essential feature of the lesions is the presence of edema with massive extravasation of plasma constituents as evidenced by specific gravity measurements, Evans blue technique and immunohistochemistry. The nerve cell injury occurring in the brain lesions in SHRSP is further characterized by light and electron microscopy in the present study. Two types of neuronal changes were seen within the blood-brain barrier (BBB) leakage sites. A small number of neurons with dark condensed nucleus and cytoplasm were found most often at the periphery of recent lesions. The majority of injured neurons were pale and showed intracellular edema confined to the dendrites and perikarya sparing axons and synapses. Their nuclei were well preserved with finely dispersed chromatin. The swollen and watery cell processes of neurons and astrocytes gave a spongy appearance to the neuropil. The intracellular edema seemed to result in cytolysis. The results suggest that primary anoxia-ischemia is not the major pathogenetic mechanism behind the nerve cell injury in severely hypertensive SHRSP, rather it is the massive BBB leakage and consequent brain edema that causes cytolytic destruction of neurons. Secondary focal ischemia as a consequence of occlusion in microvessels may, however, contribute to the nerve cell destruction.
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| 16. |
- Grabowski, Martin, et al.
(författare)
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Brain capillary density and cerebral blood flow after occlusion of the middle cerebral artery in normotensive Wistar-Kyoto rats and spontaneously hypertensive rats
- 1993
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Ingår i: Journal of Hypertension. - 1473-5598. ; 11:12, s. 1363-1368
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In order to elucidate why spontaneously hypertensive rats (SHR) develop larger brain infarcts distal to an arterial occlusion than normotensive Wistar-Kyoto (WKY) rats, we determined the surface and volume densities of cerebral capillaries, and the regional cerebral blood flow distal to an arterial occlusion in SHR and WKY rats. DESIGN: Occlusion of the middle cerebral artery was chosen because the middle cerebral artery territory is most commonly affected by cerebral infarcts in man. METHODS: Surface and volume densities of capillaries in the neocortex of the middle cerebral artery territory were measured by stereological techniques on histological sections. Fifteen minutes after ligation of the right middle cerebral artery, regional cerebral blood flow was measured autoradiographically by the [14C]-iodoantipyrine method. RESULTS: The capillary density of the neocortex did not differ between the SHR and WKY rats. The blood flow was significantly lower within the middle cerebral artery territory in the SHR than in the WKY rats. CONCLUSIONS: The reduced blood flow distal to the occlusion in SHR is probably a consequence of structural adaptation of arterial resistance vessels, rather than being caused by reduced capillary density.
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| 17. |
- Jakobsson, Mattias, et al.
(författare)
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A unique recent origin of the allotetraploid species Arabidopsis suecica: Evidence from nuclear DNA markers
- 2006
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 23:6, s. 1217-1231
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Tidskriftsartikel (refereegranskat)abstract
- A coalescent-based method was used to investigate the origins of the allotetraploid Arabidopsis suecica, using 52 nuclear microsatellite loci typed in eight individuals of A. suecica and 14 individuals of its maternal parent Arabidopsis thaliana, and four short fragments of genomic DNA sequenced in a sample of four individuals of A. suecica and in both its parental species A. thaliana and Arabidopsis arenosa. All loci were variable in A. thaliana but only 24 of the 52 microsatellite loci and none of the four sequence fragments were variable in A. suecica. We explore a number of possible evolutionary scenarios for A. suecica and conclude that it is likely that A. suecica has a recent, unique origin between 12,000 and 300,000 years ago. The time estimates depend strongly on what is assumed about population growth and rates of mutation. When combined with what is known about the history of glaciations, our results suggest that A. suecica originated south of its present distribution in Sweden and Finland and then migrated north, perhaps in the wake of the retreating ice.
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| 18. |
- Kahrstrom, J, et al.
(författare)
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A morphometric study of the effect of bilateral cervical sympathetic ganglionectomy on the architecture of pial arteries in spontaneously hypertensive and normotensive rats
- 1994
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 152:4, s. 407-418
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the cranial sympathetic nerves on the architecture of pial arteries in normo- and hypertension was examined. For this purpose the effect of bilateral superior cervical ganglionectomy was evaluated in normotensive rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). The operations were performed at the age of 1 wk, which is just prior to the onset of ganglionic transmission. The length of the inner media contour was measured and the media cross-sectional area was determined planimetrically, with computerized digitalization of projected photographic images of transversely sectioned pial arteries. Four wk after sympathectomy there was a 20% reduction in media cross-sectional area and a consequent reduction in the ratio between media area and calculated luminal radius in the major pial arteries at the base of the brain in WKY but not in SHRSP. Conversely, in small pial arteries linear regression analysis showed that in WKY subjected to ganglionectomy the relationship between media cross-sectional area and luminal radius was significantly larger in arteries with a radius less than 21 microns compared to untreated WKY. No such effect was seen in the corresponding SHRSP vessels. In addition, the cross-sectional area of the internal elastic membrane (IEM) in the basilar arteries of WKY was measured by means of a computerized image-analysing system. Mean cross-sectional area of the IEM was approximately 45% larger following SE than in control animals. The present findings propose a 'trophic' role for the sympathetic perivascular nerves in large pial arteries of the rat. The increased media-radius ratio in the small pial arteries of the WKY following sympathectomy might reflect a compensatory hypertrophy due to reduced protection from the larger arteries against the pressure load. The inability to detect any morphometrically measurable effect of the sympathectomy in the cerebral arteries of SHRSP is probably explained by a marked growth-stimulating effect of the high pressure load in these animals.
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| 19. |
- Kawakatsu, Taiji, et al.
(författare)
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Epigenomic Diversity in a Global Collection of Arabidopsis thaliana Accessions
- 2016
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Ingår i: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 166:2, s. 492-505
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Tidskriftsartikel (refereegranskat)abstract
- The epigenome orchestrates genome accessibility, functionality, and three-dimensional structure. Because epigenetic variation can impact transcription and thus phenotypes, it may contribute to adaptation. Here, we report 1,107 high-quality single-base resolution methylomes and 1,203 transcriptomes from the 1001 Genomes collection of Arabidopsis thaliana. Although the genetic basis of methylation variation is highly complex, geographic origin is a major predictor of genome-wide DNA methylation levels and of altered gene expression caused by epialleles. Comparison to cistrome and epicistrome datasets identifies associations between transcription factor binding sites, methylation, nucleotide variation, and co-expression modules. Physical maps for nine of the most diverse genomes reveal how transposons and other structural variants shape the epigenome, with dramatic effects on immunity genes. The 1001 Epigenomes Project provides a comprehensive resource for understanding how variation in DNA methylation contributes to molecular and non-molecular phenotypes in natural populations of the most studied model plant.
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| 20. |
- Kåhrström, J, et al.
(författare)
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Neonatal pre-ganglionic sympathectomy affects morphometrically defined architecture in rat cerebral arteries
- 1996
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 157:2, s. 225-231
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Tidskriftsartikel (refereegranskat)abstract
- In order to clarify further the nature of the long-term influence on the cerebral vasculature by the sympathetic nerves, a bilateral cervical pre-ganglionic denervation was performed in 1-week-old rats. Four weeks later, morphometric determinations of the vascular dimensions revealed diminished media cross-sectional areas and luminal radii in the middle cerebral and posterior cerebral arteries, whereas these parameters were unaffected in the basilar artery. In the latter artery, however, a 40% increase in the cross-sectional area of the internal elastic membrane was found. No re-innervation of the denervated ganglia occurred during the course of the experiment. The results suggest that the long-term effect exerted by the sympathetic nerves is associated with the nerve activity, rather than being a true trophic influence.
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| 21. |
- Mahanta, C., et al.
(författare)
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Hydrogeochemical controls on mobilization of arsenic in groundwater of a part of Brahmaputra river floodplain, India
- 2015
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Ingår i: Journal of Hydrology: Regional Studies. - : Elsevier BV. - 2214-5818.
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Tidskriftsartikel (refereegranskat)abstract
- Study region: Arsenic enriched groundwater regime within low-industrialized Brahmaputra floodplains in Assam, NE India. Study focus: We examined the origin, distribution and processes of As release by investigating the salient groundwater chemistry and subsurface sedimentological characteristics. Besides collection of groundwater samples from domestic and public water supply wells, sediment samples from boreholes were investigated for textural and colour linkages. New hydrological insights for the region: Arsenic concentrations above the WHO guideline value of 10. μg/L were present in 33 wells and above the previous Indian national drinking standard of 50. μg/L were present in 15 wells. The green-olive colour sediments were more likely to yield As-enriched groundwater. The supersaturation of groundwater with respect to Fe(II) minerals, such as siderite and vivianite, explained the poor correlation between dissolved As and Fe. The result reinforced the phenomenon of reductive dissolution of Fe(III) oxyhydroxides releasing As to groundwater. This study throws light on the processes and mechanisms involved with As release in groundwater. The homogenous floodplain terrain makes the hydrological As imprint unambiguous and the hydrogeological signatures untarnished. Considering the absence of anthropogenic sources in the study area, the conclusions on the nature and causes for As release to groundwater looked dependable although the final contamination at specific subsurface sites would be influenced by advection-dispersion of groundwater flow accompanied by retardation, ion exchange, surface complexation and possible biodegradation.
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| 22. |
- Mahanta, C., et al.
(författare)
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Source, distribution and release mechanisms of arsenic in the groundwater of Assam floodplains of Northeast India
- 2008
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Ingår i: World Environmental and Water Resources Congress 2008: Ahupua'a - Proceedings of the World Environmental and Water Resources Congress 2008. - Reston, VA : American Society of Civil Engineers. - 9780784409763
-
Konferensbidrag (refereegranskat)abstract
- This study conducted in Bongaigaon and Darrang districts of Assam, India is based upon water chemistry and sediment characteristics investigation in an reportedly arsenic infested belt. Of total 50 sampled wells, 15 had arsenic concentration above national drinking water standard of 50 μg/l, and 33 had As concentrations above the WHO guideline of 10 μg/l. However no distinct zones or depths with specific sedimentological features could be identified. Sediments with colour on green-olive scale are probably more likely to bear As contaminated water than white sediments. Sand filters used to reduce high iron content seem to reduce As content of water effectively. Arsenic rich water is also partly avoided since drillers seek water low in iron, which is often also low in arsenic content. Reductive dissolution of Ferric hydroxides is believed to be the release mechanism controlling the mobility of arsenic, rather than oxidation of arsenopyrite or pH induced desorption.
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| 23. |
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| 24. |
- Nordborg, C, et al.
(författare)
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Morphometric study of mesenteric and renal arteries in spontaneously hypertensive rats
- 1983
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Ingår i: Journal of Hypertension. - 1473-5598. ; 1:4, s. 333-338
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Tidskriftsartikel (refereegranskat)abstract
- Arteries from spontaneously hypertensive rats (SHR), stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto controls (WKY) were fixed by immersion and plastic embedded. The media cross-sectional area and the length of the internal elastic membrane were measured. The ratio between media thickness and internal radius was then calculated for a standardized condition, implying a perfectly smooth and circular internal elastic membrane. An increase of the media to radius ratio was already demonstrable in visceral arterial branches of SHR and SHRSP by 15 days of age, indicating that changes of arterial structure could be of pathogenetic importance in early hypertension. At seven months of age the ratio was significantly increased in mesenteric arterial branches of SHR and SHRSP and in renal arterial branches of SHRSP. The media to radius ratio was markedly increased in the renal and superior mesenteric arterial trunks of adult SHR (P less than 0.001 in both) and SHRSP (P less than 0.001 and P less than 0.01). This was due to a greater media cross-sectional area in the former vessels and to a combination of greater media and reduced radius in the latter.
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| 25. |
- Nordborg, C, et al.
(författare)
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Oedema-related tissue damage after temporary and permanent occlusion of the middle cerebral artery
- 1994
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Ingår i: Neuropathology & Applied Neurobiology. - : Wiley. - 1365-2990 .- 0305-1846. ; 20:1, s. 56-65
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Tidskriftsartikel (refereegranskat)abstract
- Eleven adults spontaneously-hypertensive male rats (SHR) were studied 22 h or 7 days after a 2 h unilateral occlusion of the right middle cerebral artery (MCA). Another 11 SHR were studied after 24 h or 7 days of permanent MCA ligation. The brain infarcts were significantly larger (P < 0.05) after permanent occlusion than after a 2 h occlusion. More extensive and widespread vasogenic oedema, emanating from the infarcts, was visualized immunohistochemically in the temporarily-ligated animals and the relative number of astrocytes in their contralateral hemispheres was greater, thereby indicating that the vasogenic oedema influences the degree of gliosis. An immunopositivity for albumin but not for fibrinogen extended via the white matter into the ipsilateral thalamic nuclei, where cytolytic nerve cell damage, severely shrunken and karyorrhectic nerve cells as well as gliosis were found one week after permanent and temporary MCA ligation. The histological changes in the thalamus indicated a difference in timing between lateral and medial parts of the lesion as well as between temporarily- and permanently-ligated SHR. These findings together with the close spatial correlation with albumin immunoreactivity indicate that the spread of extravasated plasma constituents or degradation products with the oedema bulk flow from the infarct influences the timing, character and extent of thalamic lesions after cerebral infarction.
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| 26. |
- Nordborg, C, et al.
(författare)
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Secondary thalamic lesions after ligation of the middle cerebral artery: an ultrastructural study
- 1995
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 1432-0533 .- 0001-6322. ; 91:1, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- Earlier light microscopic, immunocytochemical and morphometric investigations indicate that noxious substances transported with the vasogenic edema from hemispheric infarcts influence the character, timing and extent of the secondary thalamic lesions. The object of the present study was to analyze the ultrastructure of the secondary damage and the cytolytic nerve cell change which ensues in the thalamus within a week after the infarction. Adult spontaneously hypertensive rats (SHR) were studied either 7 days after permanent ligation of the right middle cerebral artery (MCA) (n = 4) or 7 days after a 2-h temporary occlusion of the MCA (n = 4). Light microscopy revealed damage in the ipsilateral thalamic nuclei and the electron microscopic analysis showed that the cytolytic nerve cell degeneration was somatodendritic. Central chromatolysis was not observed. Somatodendritic nerve cell degeneration, as found in the secondary thalamic lesions in the present study, has been described in excitotoxic brain damage as well as in chronic, edematous lesions in stroke-prone spontaneously hypertensive rats. The possibility that the cytolytic thalamic nerve cell lesion is influenced by excitatory, noxious substances spreading with the edema fluid from the infarct has, thus, to be considered.
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| 27. |
- Novikova, P. Y., et al.
(författare)
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Sequencing of the genus Arabidopsis identifies a complex history of nonbifurcating speciation and abundant trans-specific polymorphism
- 2016
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:9, s. 1077-1082
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Tidskriftsartikel (refereegranskat)abstract
- The notion of species as reproductively isolated units related through a bifurcating tree implies that gene trees should generally agree with the species tree and that sister taxa should not share polymorphisms unless they diverged recently and should be equally closely related to outgroups. It is now possible to evaluate this model systematically. We sequenced multiple individuals from 27 described taxa representing the entire Arabidopsis genus. Cluster analysis identified seven groups, corresponding to described species that capture the structure of the genus. However, at the level of gene trees, only the separation of Arabidopsis thaliana from the remaining species was universally supported, and, overall, the amount of shared polymorphism demonstrated that reproductive isolation was considerably more recent than the estimated divergence times. We uncovered multiple cases of past gene flow that contradict a bifurcating species tree. Finally, we showed that the pattern of divergence differs between gene ontologies, suggesting a role for selection. © 2016 Nature America, Inc. All rights reserved.
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| 28. |
- Olmarker, K, et al.
(författare)
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Chondroitinase ABC (pharmaceutical grade) for chemonucleolysis. Functional and structural evaluation after local application on intraspinal nerve structures and blood vessels.
- 1996
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436. ; 21:17, s. 1952-6
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Tidskriftsartikel (refereegranskat)abstract
- The effects on nerve tissue and blood vessels of locally applied chondroitinase ABC were studied in two experimental models using chymopapain and the vehicle of chondroitinase ABC for controls.To assess the effects of chondroitinase ABC on blood vessels and nerve tissue after local application.Chondroitinase ABC has been suggested for chemonucleolysis because it has a high specificity for nucleus pulposus matrix, which could mean a high efficiency in dissolving disc tissue combined with a low risk of side effects on other tissues.Chondroitinase ABC or controls were injected intrathecally in the pig, and nerve conduction velocity and histologic changes were assessed after 7 days. The same substances were injected into the hamster cheek pouch and studied for 60 minutes for microvascular effects. The vehicle for the enzyme was used as a negative control and chymopapain in a therapeutic concentration served as a positive control.In all series there was a slight intrathecal fibrotic reaction that was most pronounced after chymopapain injection. The effects on nerve conduction velocity and nerve morphology were similar between chondroitinase ABC and its vehicle. Chymopapain induced a significant reduction in nerve conduction velocity and pronounced histologic changes. In the cheek pouch, chymopapain induced a stand-still of blood flow at the injection site, and microhemorrhage and macromolecular leakage from the vessels at the border of the injection site. Only a slightly reduced blood flow was occasionally found after injection of chondroitinase ABC and controls.In agreement with the current literature, these observations indicate that chondroitinase ABC is safe regarding adverse effects on nerve tissue and blood vessels. The slight reduction in conduction velocity after intrathecal injection of chondroitinase ABC or its vehicle is most likely the result of surgical injury while releasing the nerve roots from the intrathecal fibrous adhesions. Such adhesions may be related to the laminectomy per se, and probably have no pathophysiologic significance.
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| 29. |
- Olmarker, K, et al.
(författare)
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Effects of chondroitinase ABC on intrathecal and peripheral nerve tissue. An in vivo experimental study on rabbits
- 1991
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Ingår i: Spine. - 0362-2436. ; 16:1, s. 43-45
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Tidskriftsartikel (refereegranskat)abstract
- The enzyme chondroitinase ABC has recently been suggested for use in chemonucleolysis. The effects of 200 U ml of chondroitinase ABC were studied on intrathecal and peripheral nerve tissue in rabbits. After the intrathecal (subarachnoid) application of 0.2 ml of either the diluent in the control group (N = 2) or chondroitinase in the study group (N = 4), no neurologic deficit was detected. Compared with the control group, no morphologic changes at the light microscopic level were induced in the spinal cord by chondroitinase. No neurophysiologic differences were detected between tibial nerves after exposure to 1 ml of the diluent (control, N = 8) or chondroitinase (the other leg) for 4 weeks, nor did the study group, compared with the control group, show any morphologic changes in the tibial nerves. Because the concentration of chondroitinase ABC tested was approximately 40 times higher than might be used clinically for chemonucleolysis, the present study indicates a wide margin of safety for unwanted side effects on nerve tissue.
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| 30. |
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| 31. |
- Risedal, Anette, et al.
(författare)
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Infarct volume and functional outcome after pre- and postoperative administration of metyrapone, a steroid synthesis inhibitor, in focal brain ischemia in the rat
- 1999
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 6:4, s. 481-486
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Tidskriftsartikel (refereegranskat)abstract
- High blood levels of glucocorticoids are associated with increased mortality, confusion and poor functional outcome in stroke patients. It has been proposed that inhibition of glucocorticoids in acute stroke might be beneficial, but experimental data are conflicting and no long-term follow-up study has been reported. We have studied whether pre- or postoperative administration of metyrapone, a steroid synthesis inhibitor, can influence long-term outcome after ligation of the right middle cerebral artery (MCA) distal to the striatal branches in hypertensive rats. Metyrapone (200 mg/kg) was administered either 30 min before or 1, 12 and 24 h after MCA occlusion. Limb placements and ability to traverse a rotating pole were evaluated pre- and postoperatively. Infarct size, histology and GFAP immunoreactivity were evaluated on 5 microm coronal sections from brains perfused in situ 4 weeks after the ischemic event. Pretreatment did not influence outcome, whereas postoperative administration of metyrapone significantly increased infarct volume (P < 0.05). Post-treated rats performed significantly worse than vehicle-treated rats on the rotating pole 3 weeks after the operation (P < 0.05). Our results do not support the hypothesis that inhibition of glucocorticoid synthesis improves outcome after cerebral ischemia.
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| 32. |
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| 33. |
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| 34. |
- Schepke, Elizabeth, et al.
(författare)
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Supratentorial CNS-PNETs in children; a Swedish population-based study with molecular re-evaluation and long-term follow-up
- 2023
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Ingår i: Clinical Epigenetics. - : Springer Science and Business Media LLC. - 1868-7075 .- 1868-7083. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMolecular analyses have shown that tumours diagnosed as supratentorial primitive neuro-ectodermal tumours of the central nervous system (CNS-PNETs) in the past represent a heterogenous group of rare childhood tumours including high-grade gliomas (HGG), ependymomas, atypical teratoid/rhabdoid tumours (AT/RT), CNS neuroblastoma with forkhead box R2 (FOXR2) activation and embryonal tumour with multi-layered rosettes (ETMR). All these tumour types are rare and long-term clinical follow-up data are sparse. We retrospectively re-evaluated all children (0-18 years old) diagnosed with a CNS-PNET in Sweden during 1984-2015 and collected clinical data.MethodsIn total, 88 supratentorial CNS-PNETs were identified in the Swedish Childhood Cancer Registry and from these formalin-fixed paraffin-embedded tumour material was available for 71 patients. These tumours were histopathologically re-evaluated and, in addition, analysed using genome-wide DNA methylation profiling and classified by the MNP brain tumour classifier.ResultsThe most frequent tumour types, after histopathological re-evaluation, were HGG (35%) followed by AT/RT (11%), CNS NB-FOXR2 (10%) and ETMR (8%). DNA methylation profiling could further divide the tumours into specific subtypes and with a high accuracy classify these rare embryonal tumours. The 5 and 10-year overall survival (OS) for the whole CNS-PNET cohort was 45% +/- 12% and 42% +/- 12%, respectively. However, the different groups of tumour types identified after re-evaluation displayed very variable survival patterns, with a poor outcome for HGG and ETMR patients with 5-year OS 20% +/- 16% and 33% +/- 35%, respectively. On the contrary, high PFS and OS was observed for patients with CNS NB-FOXR2 (5-year 100% for both). Survival rates remained stable even after 15-years of follow-up.ConclusionsOur findings demonstrate, in a national based setting, the molecular heterogeneity of these tumours and show that DNA methylation profiling of these tumours provides an indispensable tool in distinguishing these rare tumours. Long-term follow-up data confirms previous findings with a favourable outcome for CNS NB-FOXR2 tumours and poor chances of survival for ETMR and HGG.
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| 35. |
- Zeng, J, et al.
(författare)
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Are neuronal markers and neocortical graft-host interface influenced by housing conditions in rats with cortical infarct cavity?
- 1999
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Ingår i: Brain Research Bulletin. - 0361-9230. ; 48:2, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to study if exposure to an enriched environment influenced graft-host interface and neuronal markers in neocortical grafts implanted in cortical infarct cavities 3 weeks after distal ligation of the middle cerebral artery in adult hypertensive rats. Half the rats were exposed to an enriched environment for 2 h daily 5 days a week starting 1 week after the arterial ligation. The brain was fixed by perfusion 4 weeks postgrafting. The immunoreactivity to glial fibrillary acidic protein, microtubule associated protein 2, and synaptophysin was studied in coronal paraffin-embedded sections. A distinct glial border separated the infarct cavity from the surrounding brain in sham-transplanted rats. Most grafts filled the larger part of the infarct cavity. In 8 of 18 transplants, 4 in each experimental group, part of the transplants protruded through the thin glial membrane that delineated the transplant-host interface into the adjacent host brain tissue. Microtubule associated protein 2 immunostained sections indicated bridging of dendrites in the host-transplant interface. Synaptophysin immunoreactivity was significantly higher in grafts than in contralateral cortex. However, graft morphology and neuronal marker immunoreactivity did not differ between rats housed in standard and activity stimulating cages.
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