562 research outputs found

    Performance and flow dynamics studies of polymeric optofluidic sers sensors

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    We present a polymer-based optofluidic surface enhanced Raman scattering chip for biomolecule detection, serving as a disposable sensorchoice with cost-effective production. The SERS substrate is fabricated by using industrial roll-to-roll UV-nanoimprinting equipment andintegrated with adhesive-based polymeric microfluidics. The functioning of the SERS detection on-chip is confirmed and the effect of thepolymer lid on the obtainable Raman spectra is analysed. Rhodamine 6G is used as a model analyte to demonstrate continuous flowmeasurements on a planar SERS substrate in a microchannel. The relation between the temporal response of the sensors and sample flowdynamics is studied with varied flow velocities, using SERS and fluorescence detection. The response time of the surface-dependent SERSsignal is longer than the response time of the fluorescence signal of the bulk flow. This observation revealed the effect of convection on thetemporal SERS responses at 25 ÎĽl/min to 1000 ÎĽl/min flow velocities. The diffusion of analyte molecules from the bulk concentration intothe sensing surface induces about a 40-second lag time in the SERS detection. This lag time, and its rising trend with slower flow velocities, has to be taken into account in future trials of the optofluidic SERS sensor, with active analyte binding on the sensing surface

    Listeria monocytogenes isolates from invasive infections : variation of sero- and genotypes during an 11-year period in Finland.

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    Listeria monocytogenes strains that were isolated from 314 human listeriosis cases in Finland during an 11-year period were analyzed by O:H serotyping and pulsed-field gel electrophoresis (PFGE). Serotyping divided the isolates into five serotypes, the most common being 1/2a (53%) and 4b (27%). During the study period, the number of cases caused by serotype 1/2a increased from 22% in 1990 to 67% in 2001, and those caused by serotype 4b decreased from 61 to 27%, respectively. PFGE with restriction enzyme AscI divided the strains into 81 PFGE genotypes; among strains of serotypes 1/2a and 4b, 49 and 18 PFGE types were seen, respectively. PFGE type 1 (serotype 1/2a) was the most prevalent single type (37 strains). Together with six other, closely related PFGE types, PFGE type 1 formed a group of 71 strains, representing 23% of all 314 strains. Strains of PFGE type 1 have also been isolated from cold smoked fish, suggesting a source of human infections caused by this type. Moreover, PFGE type 24 (serotype 1/2c) was significantly associated with gender: 5% of 180 male subjects but none of 132 female subjects (P = 0.012). An electronic database library was created from the PFGE profiles to make possible the prompt detection of new emerging profiles and the tracing of potential infection clusters in the future

    Alarming development of dual snus and cigarette usage among young Finnish males

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    Background The consumption of tobacco products has evolved to include more complex combinations of different products. We investigated the tobacco habits of a representative population of young Finnish male conscripts in order to evaluate the prevalence of dual use of cigarettes and snus as well as the transition from one tobacco product to another. In addition, we evaluated the correlation between the level of education and the use of cigarettes and snus. Methods A questionnaire-based survey was carried out in three out of 17 garrisons among conscripts during their first week of service in 2014. A total of 1971 male conscripts were selected by simple random sampling of the 9013 males in the selected garrisons. Of them 1916 participated and filled in the questionnaire. The response rate was 97.2%. The questionnaire consisted of 25 questions including age, gender, basic education, use of tobacco products as well as questions assessing nicotine dependency. Results The amount of dual users of cigarettes and snus was 21%. There was a higher probability of dual use of cigarettes and snus among smokers compared to snus users (p < 0.001). One third (35%) of former smokers reported daily snus use and over 40% of the former snus users smoked daily. One third (34%) of the participants reported snus usage and 14% of the study subjects used snus daily. 40% of the study population were smokers and over 25% smoked daily. Of the participants with basic educational background 57% smoked daily (p < 0.001), however, no association between snus and level of education was found (p = 0.69). Conclusions This study provides better understanding of the complex tobacco habits of young adult males. The simultaneous usage of multiple tobacco products as well as the high tendency to transition from one tobacco product to another should be taken into consideration when planning cessation interventions in health care settings and tobacco control policies at societal levels

    Unexpectedly High Prevalence of Common Variable Immunodeficiency in Finland

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    Background: Common variable immunodeficiency (CVID) is the most common primary immunodeficiency. Prevalence varies greatly between countries and studies. Most diagnostic criteria include hypogammaglobulinemia and impaired vaccine response. Aim: To evaluate the minimum prevalence as well as the clinical and immunological phenotypes of CVID in Southern Finland. Methods: We performed a cross-sectional study to assess all adult CVID patients followed up in three hospital districts in Southern and South-Eastern Finland between April 2007 and August 2015. CVID diagnosis was based, with a minor modification, on the ESID/PAGID criteria for primary CVID. Antipolysaccharide responses to Pneumovax (R) were defined as impaired only if 50% or more of the serotypes did not reach a level of 0.35 mu g/mL after vaccination. We further characterized the patients' B cell phenotypes and complications associated with CVID. Results: In total, 9 patients were excluded due to potential secondary causes before diagnosis. ESID/PAGID criteria were met by 132 patients (males 52%), of whom, 106 had "probable" and 26 "possible CVID." Based on the population statistics in the three hospital districts, the minimum adult prevalence per 100,000 inhabitants in Finland for all CVID ("probable CVID," respectively) patients was 6.9 (5.5). In the highest prevalence district (Helsinki and Uusimaa), the prevalence was 7.7 (6.1). CVID patients suffer from frequent complications. Ten patients died during follow-up. Of probable CVID patients, 73% had more than one clinical phenotype. Intriguingly, gradual B cell loss from peripheral blood during follow-up was seen in as many as 16% of "Xprobable CVID" patients. Patients with possible CVID displayed somewhat milder clinical and laboratory phenotypes than probable CVID patients. We also confirm that large granular lymphocyte lymphoproliferation is a CVID-associated complication. Conclusion: The prevalence of CVID in Finland appears the highest recorded, likely reflecting the genetic isolation and potential founder effects in the Finnish population. Studies to discover potential gene variants responsible for the high prevalence in Finland thus seem warranted. Increased awareness of CVID among physicians would likely lead to earlier diagnosis and improved quality of care.Peer reviewe

    Finding genetically-supported drug targets for Parkinson's disease using Mendelian randomization of the druggable genome

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    There is currently no disease-modifying treatment for Parkinson's disease, a common neurodegenerative disorder. Here, the authors use genetic variation associated with gene and protein expression to find putative drug targets for Parkinson's disease using Mendelian randomization of the druggable genome. Parkinson's disease is a neurodegenerative movement disorder that currently has no disease-modifying treatment, partly owing to inefficiencies in drug target identification and validation. We use Mendelian randomization to investigate over 3,000 genes that encode druggable proteins and predict their efficacy as drug targets for Parkinson's disease. We use expression and protein quantitative trait loci to mimic exposure to medications, and we examine the causal effect on Parkinson's disease risk (in two large cohorts), age at onset and progression. We propose 23 drug-targeting mechanisms for Parkinson's disease, including four possible drug repurposing opportunities and two drugs which may increase Parkinson's disease risk. Of these, we put forward six drug targets with the strongest Mendelian randomization evidence. There is remarkably little overlap between our drug targets to reduce Parkinson's disease risk versus progression, suggesting different molecular mechanisms. Drugs with genetic support are considerably more likely to succeed in clinical trials, and we provide compelling genetic evidence and an analysis pipeline to prioritise Parkinson's disease drug development.Peer reviewe

    Finding genetically-supported drug targets for Parkinson's disease using Mendelian randomization of the druggable genome

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    There is currently no disease-modifying treatment for Parkinson's disease, a common neurodegenerative disorder. Here, the authors use genetic variation associated with gene and protein expression to find putative drug targets for Parkinson's disease using Mendelian randomization of the druggable genome. Parkinson's disease is a neurodegenerative movement disorder that currently has no disease-modifying treatment, partly owing to inefficiencies in drug target identification and validation. We use Mendelian randomization to investigate over 3,000 genes that encode druggable proteins and predict their efficacy as drug targets for Parkinson's disease. We use expression and protein quantitative trait loci to mimic exposure to medications, and we examine the causal effect on Parkinson's disease risk (in two large cohorts), age at onset and progression. We propose 23 drug-targeting mechanisms for Parkinson's disease, including four possible drug repurposing opportunities and two drugs which may increase Parkinson's disease risk. Of these, we put forward six drug targets with the strongest Mendelian randomization evidence. There is remarkably little overlap between our drug targets to reduce Parkinson's disease risk versus progression, suggesting different molecular mechanisms. Drugs with genetic support are considerably more likely to succeed in clinical trials, and we provide compelling genetic evidence and an analysis pipeline to prioritise Parkinson's disease drug development.Peer reviewe

    Prevalence and diversity of Salmonella enterica in water, fish and lettuce in Ouagadougou, Burkina Faso

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    Abstract Background This study investigated the prevalence, serotypes and antimicrobial sensitivity patterns of Salmonella enterica in environment in Ouagadougou, Burkina Faso. A total of 476 samples, consisting of 36 samples of tap water, 51 samples of well water, 87 samples of channel water, 44 samples of reservoir water, 238 samples of fish, and 20 samples of lettuce were examined using standard bacteriological procedures for Salmonella. Results Salmonella were isolated from 98 samples. Salmonella were rare in drinking water, since they were not found at all from the tap water, and only in 2 % of well water. Salmonella were more common in the water of reservoir of Tanghin (15 %), reservoir of Yamtenga (20 %), and in the water channels in the city (from 20 to 31 %). Salmonella were commonly isolated from the fish (24 %) caught from the reservoir of Tanghin and from the lettuce (50 %) irrigated with water from Tanghin. The Salmonella isolates were found to represent 50 different serotypes. The 11 most common serotypes were Salmonella Bredeney and S. Colindale (both 8.2 %), S. Muenster (6.1 %), S. Korlebu (5.1 %), S. Eastbourne and S. Poona (both 4.1 %), and S. Agona, S. Derby, S. Drac, S. Senftenberg, S. Waycross (each 3.1 %), accounting for 51.3 % of all the isolates. In general, the Salmonella strains were sensitive to the antimicrobials tested, but two strains were resistant to streptomycin and many more intermediate to streptomycin or sulphonamide. Conclusion This study highlights the common prevalence of Salmonella and the high diversity of Salmonella serotypes in aquatic environment in Ouagadougou, Burkina Faso. Therefore, various human activities linked to water and consumption of water-related products, such as fish and lettuce, can lead to human Salmonella infections

    Prevalence and diversity of Salmonella enterica in water, fish and lettuce in Ouagadougou, Burkina Faso

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    Background: This study investigated the prevalence, serotypes and antimicrobial sensitivity patterns of Salmonella enterica in environment in Ouagadougou, Burkina Faso. A total of 476 samples, consisting of 36 samples of tap water, 51 samples of well water, 87 samples of channel water, 44 samples of reservoir water, 238 samples of fish, and 20 samples of lettuce were examined using standard bacteriological procedures for Salmonella. Results: Salmonella were isolated from 98 samples. Salmonella were rare in drinking water, since they were not found at all from the tap water, and only in 2 % of well water. Salmonella were more common in the water of reservoir of Tanghin (15 %), reservoir of Yamtenga (20 %), and in the water channels in the city (from 20 to 31 %). Salmonella were commonly isolated from the fish (24 %) caught from the reservoir of Tanghin and from the lettuce (50 %) irrigated with water from Tanghin. The Salmonella isolates were found to represent 50 different serotypes. The 11 most common serotypes were Salmonella Bredeney and S. Colindale (both 8.2 %), S. Muenster (6.1 %), S. Korlebu (5.1 %), S. Eastbourne and S. Poona (both 4.1 %), and S. Agona, S. Derby, S. Drac, S. Senftenberg, S. Waycross (each 3.1 %), accounting for 51.3 % of all the isolates. In general, the Salmonella strains were sensitive to the antimicrobials tested, but two strains were resistant to streptomycin and many more intermediate to streptomycin or sulphonamide. Conclusion: This study highlights the common prevalence of Salmonella and the high diversity of Salmonella serotypes in aquatic environment in Ouagadougou, Burkina Faso. Therefore, various human activities linked to water and consumption of water-related products, such as fish and lettuce, can lead to human Salmonella infections.Peer reviewe
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