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- Ahmed Osman, Omneya, et al.
(författare)
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Interactions of Freshwater Cyanobacteria with Bacterial Antagonists
- 2017
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 83:7
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Tidskriftsartikel (refereegranskat)abstract
- Cyanobacterial and algal mass development, or blooms, have severe effects on freshwater and marine systems around the world. Many of these phototrophs produce a variety of potent toxins, contribute to oxygen depletion, and affect water quality in several ways. Coexisting antagonists, such as cyanolytic bacteria, hold the potential to suppress, or even terminate, such blooms, yet the nature of this interaction is not well studied. We isolated 31 cyanolytic bacteria affiliated with the genera Pseudomonas, Stenotrophomonas, Acinetobacter, and Delftia from three eutrophic freshwater lakes in Sweden and selected four phylogenetically diverse bacterial strains with strong-to-moderate lytic activity. To characterize their functional responses to the presence of cyanobacteria, we performed RNA sequencing (RNA-Seq) experiments on coculture incubations, with an initial predator-prey ratio of 1: 1. Genes involved in central cellular pathways, stress-related heat or cold shock proteins, and antitoxin genes were highly expressed in both heterotrophs and cyanobacteria. Heterotrophs in coculture expressed genes involved in cell motility, signal transduction, and putative lytic activity. L, D-Transpeptidase was the only significantly upregulated lytic gene in Stenotrophomonas rhizophila EK20. Heterotrophs also shifted their central metabolism from the tricarboxylic acid cycle to the glyoxylate shunt. Concurrently, cyanobacteria clearly show contrasting antagonistic interactions with the four tested heterotrophic strains, which is also reflected in the physical attachment to their cells. In conclusion, antagonistic interactions with cyanobacteria were initiated within 24 h, and expression profiles suggest varied responses for the different cyanobacteria and studied cyanolytes. IMPORTANCE Here, we present how gene expression profiles can be used to reveal interactions between bloom-forming freshwater cyanobacteria and antagonistic heterotrophic bacteria. Species-specific responses in both heterotrophs and cyanobacteria were identified. The study contributes to a better understanding of the interspecies cellular interactions underpinning the persistence and collapse of cyanobacterial blooms.
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| 4. |
- Bertilsson, Sara, et al.
(författare)
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Acute Pancreatitis : Impact of Alcohol Consumption and Seasonal Factors
- 2017
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Ingår i: Alcohol and Alcoholism. - : Oxford University Press (OUP). - 1464-3502 .- 0735-0414. ; 52:3, s. 383-389
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Tidskriftsartikel (refereegranskat)abstract
- Aims: We aimed to evaluate the potential relation between the incidence of (alcoholic and non-alcoholic) acute pancreatitis (AP) and alcohol consumption in the general population, and whether the occurrence of AP shows any seasonal variation, particularly in relation to periods with expected increased alcohol consumption.Methods: All patients with first-time AP between 2003 and 2012 in a well-defined area in Sweden were retrospectively identified. Data on AP aetiology (alcoholic and non-alcoholic) and severity were registered. Data on annual alcohol sales as well as on self-reported alcohol consumption were obtained.Results: In total, 1457 AP patients were included (83% non-alcoholic AP, 17% alcoholic AP). The overall AP incidence showed increasing time trends for women and men (P < 0.05), but there were no significant changes in the incidence of alcoholic AP, in either sex (P > 0.05). Alcohol sales during the study period decreased (P = 0.002), mainly due to decreased sales of spirits (P = 0.001) and beer (P = 0.002), while self-reported alcohol consumption remained stable for women (P > 0.05) and decreased for men (P = 0.022). Neither alcohol sales nor consumption was related to the time trends of AP (P > 0.05 for all). No significant differences were found in the occurrence of AP among different seasons of the year or between holidays associated with higher alcohol consumption compared to periods before and after these holidays (P > 0.05 for all).Conclusions: Changes in alcohol consumption in the general population do not appear to be related to changes in the incidence of AP and there are no significant seasonal differences in the occurrence of AP in Sweden.Short summary: The incidence of acute pancreatitis (AP) is increasing, and alcohol is still recognized as one of the most common causes. In this study, however, we could not ascertain any clear relations between the sales and consumption of alcohol in the general population and the incidence of alcoholic or non-alcoholic AP.
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| 5. |
- Bertilsson, Sara, et al.
(författare)
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Factors That Affect Disease Progression After First Attack of Acute Pancreatitis
- 2015
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Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier BV. - 1542-7714 .- 1542-3565. ; 13:9, s. 1662-1669
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Little is known about recurrence of pancreatitis after an initial episode, and little is known about how the disease progresses or what factors affect progression. We performed a population-based study of patients with acute pancreatitis (AP) to determine their outcomes and associated factors. METHODS: We performed a retrospective study of patients with first-time AP from 2003 through 2012 in a well-defined area of Sweden. Data were collected from medical records on disease etiology, severity (according to the Atlanta classification), recurrence of AP, subsequent chronic pancreatitis, and mortality. Patients were followed up for a median time of 4.6 years, until death or the end of 2013. RESULTS: We identified 1457 patients with first-time AP (48% biliary disease, 17% alcohol-associated, 9.9% severe); 23% of patients had 1 or more recurrences. Risk for recurrence was significantly higher among smokers (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.03-1.95; P = .03), patients with alcohol-associated AP (HR, 1.58; 95% CI, 1.25-2.23; P < .01), after organ failure (HR, 1.46; 95% CI 1.05-2.03; P = .02), and in patients with systemic complications (HR, 1.88; 95% CI, 1.27-2.79; P < .01) or local complications (HR, 1.66; 95% CI, 1.22-2.27; P < .01). AP of all etiologies progressed to chronic pancreatitis, although alcohol-associated AP progressed most frequently (2.8/100 patient-years). Patients with recurrent AP were at the highest risk for chronic pancreatitis (HR, 6.74; 95% CI, 4.02-11.3; P < .01), followed by alcohol-associated AP (HR, 3.10; 95% CI, 2.05-5.87; P < .01), smoking (HR, 2.26; 95% CI, 1.12-4.58; P = .02), systemic complications (HR, 1.37; 95% CI, 1.06-4.62; P = .03), and peripancreatic necrosis (HR, 2.74; 95% CI, 1.7-4.43; P < .01). In-hospital mortality was 2.8%, and independently associated only with organ failure (odds ratio, 71.17; 95% CI, 21.14-239.60; P < .01). Fifty-three percent of patients who died during disease recurrence had biliary AP; a higher percentage of these patients died upon first recurrence (5.9%) than upon first attack of AP (2%; P = .01). CONCLUSIONS: The severity of first-time AP, smoking, and alcohol abuse are related to recurrence and subsequent chronic pancreatitis. Recurrence increases the risk for progression to chronic pancreatitis. Most patients who die upon disease recurrence have biliary AP.
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| 6. |
- Bertilsson, Sara, et al.
(författare)
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Microproteinuria Predicts Organ Failure in Patients Presenting with Acute Pancreatitis
- 2016
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Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 61:12, s. 3592-3601
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: The disease course of acute pancreatitis (AP) ranges from mild and self-limiting to severe inflammation, associated with significant morbidity and mortality. At present, there are no universally accepted and reliable predictors for severity. Microproteinuria has been associated with the presence of systemic inflammatory response syndrome as well as trauma, although its association with AP is not well understood. The aim of this study was to investigate the value of microproteinuria to predict development of organ failure in AP.METHODS: Consecutive AP patients were prospectively enrolled. Urine samples were collected upon admission, 12-24 h after admission, and 3 months post-discharge for calculation of urine α1-microglobulin-, albumin-, IgG-, and IgM/creatinine ratios. Data regarding AP etiology, severity, and development of organ failure were registered.RESULTS: Overall, 92 AP patients were included (14 % with organ failure; 6 % with severe AP). The α1-microglobulin-, albumin-, and IgG/creatinine ratios correlated with high-sensitivity C-reactive protein 48 h after admission (r = 0.47-0.61, p < 0.001 for all). They were also significantly higher in patients with versus without organ failure (p < 0.05 for all). The α1-microglobulin/creatinine ratio upon admission predicted organ failure [adjusted odds ratio 1.286, 95 % confidence interval (CI) 1.024-1.614] with similar accuracy (AUROC 0.81, 95 % CI 0.69-0.94) as the more complex APACHE II score (AUROC 0.86, 95 % CI 0.70-1.00).CONCLUSION: The α1-microglobulin/creatinine ratio upon presentation with AP is related to inflammation and predicts development of organ failure. Further studies are warranted to evaluate its potential usefulness in predicting outcome for AP patients.
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| 7. |
- Grubisic, Lorena M., et al.
(författare)
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Lake bacterioplankton dynamics over diurnal timescales
- 2017
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Ingår i: Freshwater Biology. - : Blackwell Publishing. - 0046-5070 .- 1365-2427. ; 62:1, s. 191-204
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Tidskriftsartikel (refereegranskat)abstract
- 1. Planktonic bacterial community dynamics over short timescales can be of great importance for food webs and ecosystem functioning but are rarely described when microbial community and composition are assessed. To study the significance of such dynamics we sampled the surface water at the deepest point of a mesotrophic lake (Lake Erken, Sweden) every third hour over two days. 2. By combining 454 pyrosequencing of 16S rRNA genes with bromodeoxyuridine immunocapturing of DNA, replicating populations were identified and compared to the community retrieved from total DNA samples. This comparison revealed a significant difference between the actively replicating and total community. 3. The high-frequency diurnal sampling was compared to a year-long survey conducted in the same lake in order to compare the diurnal and seasonal variation in bacterioplankton community composition. At the diurnal-scale, the variation was significantly higher in the replicating than in the total community. However, variation in both active and total diurnal community was significantly lower than the variation in the seasonal total community. 4. Our analysis revealed pronounced short-term dynamics of individual bacterial populations uncoupled from the diurnal light cycle. For example, the proliferating fraction of the most abundant bacterial tribe (LD12) followed a cyclic pattern that covaried with viral abundance. This implies that environmental factors other than light may act as important drivers of microbial community composition, at least in mesotrophic Lake Erken.
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| 8. |
- Larsson, Ellinor, et al.
(författare)
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Välfärdsteknik - Digitala verktyg som social stimulans för äldre personer med eller vid risk för psykisk ohälsa : En kartläggning av systematiska översikter
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SyfteSyftet med SBU:s rapport är att kartlägga vetenskaplig kunskap samt vetenskapliga kunskapsluckor. Detta baseras på systematiska översikter som undersökt effekter, upplevelser eller erfarenheter av digitala verktyg som social stimulans för att minska eller förebygga psykisk ohälsa bland äldre personer. Vad tillför denna kartläggning? För äldre personer med eller vid risk för psykisk ohälsa finns det översikter som visar att utbildning i och användning av dator och internet kan minska ensamhet men evidensläget är svagt. Kunskapsluckor finns för domänerna livskvalitet, ADL-förmåga (Aktiviteter i det Dagliga Livet), kognition, självständighet samt användbarhet av tekniken.BakgrundVälfärdsteknik inrymmer digitala verktyg som syftar till att bibehålla eller öka trygghet, aktivitet, delaktighet eller självständighet för en person som har eller löper förhöjd risk att få en funktionsnedsättning. Välfärdsteknik kan fungera som ett hjälpmedel för den enskilde och utgörs av medicintekniska produkter alternativt konsumentprodukter vilka kan köpas i öppna handeln. Välfärdsteknik antas kunna bidra till ett aktivt och hälsosamt åldrande, även för åldrandeprocesser som sker genom hela livet och ter sig olika för varje individ.MetodEn systematisk kartläggning innebär att frågeställningen och domäner identifieras. Dessa ligger sedan till grund för en systematisk litteratursökning. Efter litteratursökningen identifieras, relevans- och kvalitetsbedöms systematiska översikter och slutligen sammanställs resultaten i de inkluderade systematiska översikterna. Kartläggningen inkluderar ingen kvalitetsbedömning av de studier som ingår i de systematiska översikterna. Denna kartläggning utgår från sju översikter av medelhög kvalitet från åren 2012 till 2017 och presenterar data från både kvantitativ och kvalitativ forskningsdesign. I kartläggningen görs ingen evidensgradering. Mer detaljerad information kring metod samt avgränsningar finns i rapporten.HuvudresultatI kartläggningen ingår sju systematiska översikter av medelhög kvalitet som visar på kunskap eller kunskapsluckor inom de identifierade domänerna.
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| 9. |
- Monard, Cécile, et al.
(författare)
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Habitat generalists and specialists in microbial communities across a terrestrial-freshwater gradient
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Observations of distributions of microorganisms and their differences in community composition across habitats provide evidence of biogeographical patterns. However, little is known about the processes controlling transfers across habitat gradients. By analysing the overall microbial community composition (bacteria, fungi, archaea) across a terrestrial-freshwater gradient, the aim of this study was to understand the spatial distribution patterns of populations and identify taxa capable of crossing biome borders. Barcoded 454 pyrosequencing of taxonomic gene markers was used to describe the microbial communities in adjacent soil, freshwater and sediment samples and study the role of biotic and spatial factors in shaping their composition. Few habitat generalists but a high number of specialists were detected indicating that microbial community composition was mainly regulated by species sorting and niche partitioning. Biotic interactions within microbial groups based on an association network underlined the importance of Actinobacteria, Sordariomycetes, Agaricomycetes and Nitrososphaerales in connecting among biomes. Even if dispersion seemed limited, the shore of the lake represented a transition area, allowing populations to cross the biome boundaries. In finding few broadly distributed populations, our study points to biome specialization within microbial communities with limited potential for dispersal and colonization of new habitats along the terrestrial-freshwater continuum.
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