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- Lukasch, B., et al.
(författare)
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Major histocompatibility complex genes partly explain early survival in house sparrows
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Environmental factors and genetic incompatibilities between parents have been suggested as important determinants for embryonic mortality and survival. The genetic set-up of the immune system, specifically the highly polymorphic major histocompatibility complex (MHC) may also influence individual resistance to infections. MHC proteins are important for an appropriate adaptive immune response and enable T-cells to separate 'self' from 'non-self'. Here we investigate the importance of MHC functional diversity for early development in birds, more specifically, if offspring survival and body mass or size depends on number of different functional MHC alleles, specific functional MHC alleles or similarity of MHC alleles in the parents. Unhatched eggs are common in clutches of many bird species. In house sparrows (Passer domesticus), embryo and nestling mortality can exceed 50%. To control for environmental factors, our study was carried out on an aviary population. We found that one specific functional MHC allele was associated with reduced nestling survival, which was additionally supported by lower body mass and a smaller tarsus when nestlings have been 6 days old. Another allele was positively associated with tarsus length at a later nestling stage (nestlings 12 days old). These results indicate that MHC alleles might influence pathogen resistance or susceptibility.
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2. |
- Schrey, A W, et al.
(författare)
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Broad-scale latitudinal patterns of genetic diversity among native European and introduced house sparrow (Passer domesticus) populations.
- 2011
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Ingår i: Molecular Ecology. - 0962-1083. ; 20, s. 1133-1143
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Tidskriftsartikel (refereegranskat)abstract
- Introduced species offer unique opportunities to study evolution in new environments, and some provide opportunities for understanding the mechanisms underlying macroecological patterns. We sought to determine how introduction history impacted genetic diversity and differentiation of the house sparrow (Passer domesticus), one of the most broadly distributed bird species. We screened eight microsatellite loci in 316 individuals from 16 locations in the native and introduced ranges. Significant population structure occurred between native than introduced house sparrows. Introduced house sparrows were distinguished into one North American group and a highly differentiated Kenyan group. Genetic differentiation estimates identified a high magnitude of differentiation between Kenya and all other populations, but demonstrated that European and North American samples were differentiated too. Our results support previous claims that introduced North American populations likely had few source populations, and indicate house sparrows established populations after introduction. Genetic diversity also differed among native, introduced North American, and Kenyan populations with Kenyan birds being least diverse. In some cases, house sparrow populations appeared to maintain or recover genetic diversity relatively rapidly after range expansion (<50 years; Mexico and Panama), but in others (Kenya) the effect of introduction persisted over the same period. In both native and introduced populations, genetic diversity exhibited large-scale geographic patterns, increasing towards the equator. Such patterns of genetic diversity are concordant with two previously described models of genetic diversity, the latitudinal model and the species diversity model.
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4. |
- Aguilar, J. Rivero De, et al.
(författare)
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MHC-I provides both quantitative resistance and susceptibility to blood parasites in blue tits in the wild
- 2016
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857. ; 47:5, s. 669-677
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Tidskriftsartikel (refereegranskat)abstract
- Major histocompatibility complex (MHC) genes are central for the adaptive immune response against parasites. Here, we investigated potential associations among MHC-I alleles and blood parasite infections in a natural breeding population of a passerine bird, the blue tit Cyanistes caeruleus, in central Spain. We screened both infection status (presence/absence of infection) and infection intensity to the pathogenic blood parasites Haemoproteus and Leucocytozoon. Three MHC-I alleles (UA104, UA108 and UA117) were associated with higher or lower infection intensities by Leucocytozoon. Interestingly, these associations were dependent on age and were found both among young and adult birds. No MHC alleles were associated with infection intensity by Haemoproteus parasites. In addition, no significant relationships were detected between infection status by Haemoproteus and Leucocytozoon infections and MHC alleles. The very high prevalence of these two parasites in our study population (79-100%) poses challenges to identify associations with infection status and also suggests that clearance of infections may be rare. In conclusion, associations between specific MHC-I alleles and Leucocytozoon parasites were related to either high or low infection intensities, and hence increased susceptibility or resistance to infection.
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6. |
- Antonsson, M., et al.
(författare)
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Lungefysioterapi ved abdominal- og thoraxkirurgi
- 2011
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Ingår i: Fysioterapeuten. ; 9
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- I snart hundrede år har fysioterapeuter arbejdet på at mindske risikoen for postoperative lungekomplikationer hos patienter, der skal opereres i brystkassen og abdominalregionen. Klinisk erfaring viser, at lungefysioterapi er vigtig, men hvad ved vi i dag om effekten af forskellige former for behandling? Hvilke indsatsområder skal man i første omgang vælge? Forfatterne til denne artikel har udarbejdet retningslinjer for lungefysioterapi til patienter, som gennemgår abdominal- og thoraxkirurgi. Målet med arbejdet med retningslinjerne har været at udrede og sammensætte eksisterende evidens for lungefysioterapeutiske behandlingsmetoder i forbindelse med abdominal- og thoraxkirurgiske indgreb. Den samlede evidens i kombination med ekspertgruppens kommentarer har ført til anbefalinger for den kliniske behandling. Disse anbefalinger er målrettet fysioterapeuter i den kliniske praksis, som arbejder med abdominal - og thoraxkirurgiske patienter. Sigtet er, at den aktuelle og systematisk indsamlede viden vil bidrage til diskussioner på de forskellige arbejdspladser, og at anbefalingerne for behandling vil blive tilpasset de lokale forhold. Denne artikel sammenfatter retningslinjerne, som er publiceret på fysioterapiforbundets (Legitimerede Sjukgymnasters) hjemmeside under profession. De kliniske retningslinjer omfatter desuden en komplet referenceliste.
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8. |
- Ferraguti, Martina, et al.
(författare)
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Environmental, geographical and time-related impacts on avian malaria infections in native and introduced populations of house sparrows (Passer domesticus), a globally invasive species
- 2023
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 32:5, s. 809-823
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The increasing spread of vector-borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations. Location: Global. Time period: 2002–2019. Major taxa studied: Avian Plasmodium parasites in house sparrows. Methods: We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests. Results: Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected. Main conclusions: Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows.
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9. |
- Måsbäck, A, et al.
(författare)
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Cutaneous malignant melanoma in southern Sweden 1965, 1975, and 1985. Prognostic factors and histologic correlations
- 1997
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Ingår i: Cancer. - 0008-543X. ; 79:2, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is a worldwide increase in the incidence of cutaneous malignant melanoma (CMM) among whites. In Sweden, a five-fold increase has been recorded since 1960, although the increase in mortality rate is substantially lower. Tumor thickness is recognized as the most important histologic prognostic factor for primary melanoma. In a previous study, the authors did not find any significant decrease in mean tumor thickness over the period 1965-1985 in their region. In the current study, prognostic factors for melanoma were evaluated for this time period.METHODS: In a population-based study, 468 cases of invasive melanoma, diagnosed in the years 1965, 1975, and 1985, were histopathologically reexamined. The level of invasion, tumor thickness, regressive reaction, ulceration, presence of inflammatory cells, presence of benign nevus cells, and site of presentation were studied. In 461 of these 468 patients, it was possible to correlate the histopathologic factors with survival.RESULTS: In univariate analyses, the parameters of presence of ulceration, increasing tumor thickness, male gender, nodular type of melanoma, and older age at diagnosis were significantly related to a shortened overall survival. In various multivariate models with adjustment for age and the factors studied simultaneously, ulceration, increasing tumor thickness, and male gender were significantly associated with a poor prognosis. Correlations between the factors studied were noted. It was observed that older patients tended to have thicker tumors. Thick melanomas correlated to a deeper level of invasion (Clark's), nodular growth pattern, ulceration, less inflammation, and less regression compared with thin, less invasive melanomas. Women had significantly fewer inflammatory cells and fewer signs of regression in their tumors compared with men.CONCLUSIONS: In multivariate analyses adjusted for age, increasing tumor thickness, older age, ulceration, and male gender were significantly associated with a poor prognosis among patients with invasive CMM. None of these factors showed a significant change for the years 1965, 1975, and 1985. Thus, a change in the prognostic factors studied does not explain the increased survival of melanoma patients for this time period.
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11. |
- Näpflin, Kathrin, et al.
(författare)
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Genomics of host-pathogen interactions: challenges and opportunities across ecological and spatiotemporal scales
- 2019
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Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Evolutionary genomics has recently entered a new era in the study of host-pathogen interactions. A variety of novel genomic techniques has transformed the identification, detection and classification of both hosts and pathogens, allowing a greater resolution that helps decipher their underlying dynamics and provides novel insights into their environmental context. Nevertheless, many challenges to a general understanding of host-pathogen interactions remain, in particular in the synthesis and integration of concepts and findings across a variety of systems and different spatiotemporal and ecological scales. In this perspective we aim to highlight some of the commonalities and complexities across diverse studies of host-pathogen interactions, with a focus on ecological, spatiotemporal variation, and the choice of genomic methods used. We performed a quantitative review of recent literature to investigate links, patterns and potential tradeoffs between the complexity of genomic, ecological and spatiotemporal scales undertaken in individual host-pathogen studies. We found that the majority of studies used whole genome resolution to address their research objectives across a broad range of ecological scales, especially when focusing on the pathogen side of the interaction. Nevertheless, genomic studies conducted in a complex spatiotemporal context are currently rare in the literature. Because processes of host-pathogen interactions can be understood at multiple scales, from molecular-, cellular-, and physiological-scales to the levels of populations and ecosystems, we conclude that a major obstacle for synthesis across diverse host-pathogen systems is that data are collected on widely diverging scales with different degrees of resolution. This disparity not only hampers effective infrastructural organization of the data but also data granularity and accessibility. Comprehensive metadata deposited in association with genomic data in easily accessible databases will allow greater inference across systems in the future, especially when combined with open data standards and practices. The standardization and comparability of such data will facilitate early detection of emerging infectious diseases as well as studies of the impact of anthropogenic stressors, such as climate change, on disease dynamics in humans and wildlife.
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13. |
- Westerdahl, J., et al.
(författare)
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At what age do sunburn episodes play a crucial role for the development of malignant melanoma
- 1994
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 0959-8049. ; 30:11, s. 1647-1654
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Tidskriftsartikel (refereegranskat)abstract
- The age relationship between sunburns and malignant melanoma was investigated in a population-based, matched, case-control study from the South Swedish Health Care Region (the highest risk area for melanoma in Sweden). Between 1988 and 1990, a total of 400 patients with a first diagnosis of malignant melanoma and 640 healthy controls aged 15-75 years answered a comprehensive questionnaire including questions regarding ultraviolet radiation exposure. In addition, a literature review was performed. The average number of episodes of sunburn per year was significantly associated with malignant melanoma (relative risk, RR = 1.9 for ≥ three episodes per year versus never). Outdoor employment during the summer was associated with a decreased risk for the development of malignant melanoma (RR = 0.8). Data from case-control studies and migration studies concerning age relationship between sunburns and melanom are inconsistent. From our own data, we did not find a higher risk of melanoma developed in individuals who had experienced severe sunburns in childhood. Instead, a significantly increased risk was associated with sunburns after age 19 years, RR = 2.2 for a history of more than five times versus never. Even if the hypothesis is biologically plausible, that episodes of sunburn early in life are associated with a higher risk of melanoma, so far epidemiological evidence is scarce. There is a need for better prospective epidemiological studies addressing this issue.
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14. |
- Westerdahl, J, et al.
(författare)
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Reproducibility of a self-administered questionnaire for assessment of melanoma risk
- 1996
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Ingår i: International Journal of Epidemiology. - 0300-5771. ; 25:2, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The reproducibility of a self-administered questionnaire on different epidemiological variables was examined in a random sample of a cohort of healthy women from the South Swedish Health Care Region. An identical questionnaire has previously been used for assessment of melanoma risk, in a population-based, matched, case-control study from the same region.METHODS: Repeat questionnaires were completed on two occasions, 1-3 years apart, by 670 randomly selected subjects. In addition, exposure data from a case-control study were used to estimate the effect of misclassification.RESULTS: Overall, there was a fair to good consistency between the answers on the two occasions for the various epidemiological variables. Exposure variables identified as risk factors for melanoma development were reasonably reproducible. The estimated proportion of agreement, A, ranged from 0.74 to 0.92, the average correct classification rate (assuming common sensitivity and specificity), pi, was > or = 0.85 and the kappa coefficient, kappa, ranged between 0.52 and 0.83. However, the question on number of raised naevi on the arm was an exception since it had a lower test-retest reliability (A = 0.62, pi = 0.77, kappa = 0.40). When using data from the case-control study, the effect of the estimated random misclassification was found to only slightly bias odds ratios toward one.CONCLUSION: Our questionnaire, used for assessment for melanoma risk, provided information with fair to good test-retest reliability, and corrected odds ratios were found to be only slightly higher than observed odds ratios.
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- Westerdahl, J., et al.
(författare)
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Southern travelling habits with special reference to tumour site in Swedish melanoma patients
- 1992
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Ingår i: Anticancer research. - 0250-7005. ; 12:5, s. 1539-1542
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Tidskriftsartikel (refereegranskat)abstract
- Southern travelling habits were recorded for 127 melanoma patients from southern parts of Sweden (the 56th latitude), 55 thyroid cancer patients, 100 non-Hodgkin's patients and 794 healthy controls from the same region. Melanoma patients were found to travel significantly more often south of the 45th latitude, as compared with patients with non-Hodgkin's lymphoma or thyroid carcinoma (RR = 2.2 for a difference of + 10 trips), and with the healthy controls (RR = 1.4 for a difference of + 10 trips). Considering men and women sepatately, the difference was significant only for men. Patients with melanoma had a higher educational level than the tumour controls and the healthy controls (p<0.001 and p<0.001 respectively). There was a significant correlation between high travelling frequency and high education. An increased risk related to southern travelling was present for patients with melanoma on the extremities and head and neck, as well as for patients with truncal melanoma. These findings support the concept that acute exposure to sunburn may be a risk factor for malignant melanoma.
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16. |
- Wienecke, J, et al.
(författare)
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Global gene expression analysis of rodent motor neurons following spinal cord injury associates molecular mechanisms with development of postinjury spasticity
- 2010
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Ingår i: Journal of neurophysiology. - : American Physiological Society. - 1522-1598 .- 0022-3077. ; 103:2, s. 761-778
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Tidskriftsartikel (refereegranskat)abstract
- Spinal cord injury leads to severe problems involving impaired motor, sensory, and autonomic functions. After spinal injury there is an initial phase of hyporeflexia followed by hyperreflexia, often referred to as spasticity. Previous studies have suggested a relationship between the reappearance of endogenous plateau potentials in motor neurons and the development of spasticity after spinalization. To unravel the molecular mechanisms underlying the increased excitability of motor neurons and the return of plateau potentials below a spinal cord injury we investigated changes in gene expression in this cell population. We adopted a rat tail-spasticity model with a caudal spinal transection that causes a progressive development of spasticity from its onset after 2 to 3 wk until 2 mo postinjury. Gene expression changes of fluorescently identified tail motor neurons were studied 21 and 60 days postinjury. The motor neurons undergo substantial transcriptional regulation in response to injury. The patterns of differential expression show similarities at both time points, although there are 20% more differentially expressed genes 60 days compared with 21 days postinjury. The study identifies targets of regulation relating to both ion channels and receptors implicated in the endogenous expression of plateaux. The regulation of excitatory and inhibitory signal transduction indicates a shift in the balance toward increased excitability, where the glutamatergic N-methyl-d-aspartate receptor complex together with cholinergic system is up-regulated and the γ-aminobutyric acid type A receptor system is down-regulated. The genes of the pore-forming proteins Cav1.3 and Nav1.6 were not up-regulated, whereas genes of proteins such as nonpore-forming subunits and intracellular pathways known to modulate receptor and channel trafficking, kinetics, and conductivity showed marked regulation. On the basis of the identified changes in global gene expression in motor neurons, the present investigation opens up for new potential targets for treatment of motor dysfunction following spinal cord injury.
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