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  • Almeda-Valdes, Paloma; Cuevas-Ramos, Daniel; Mehta, Roopa; Muñoz-Hernandez, Liliana; Cruz-Bautista, Ivette; Perez-Mendez, Oscar; Tusie-Luna, Maria T; Gomez-Perez, Francisco J; Pajukanta, Päivi; Matikainen, Niina; Taskinen, Marja-Riitta; Aguilar-Salinas, Carlos A (BioMed Central Ltd, 2014)
    Abstract Background Alterations in postprandial metabolism have been described in familial combined hyperlipidemia (FCH); however, their underlying mechanisms are not well characterized. We aimed to identify factors related to the magnitude of postprandial lipemia and apolipoprotein (apo) A-V levels in subjects with FCH. Methods FCH cases (n = 99) were studied using a standardized meal test. Abdominal obesity was assessed using the waist to hip ratio (WHR). A linear regression model was performed to investigate the variables associated with the triglycerides incremental area under the curve (iAUC). Independent associations between metabolic variables and apo A-V iAUC were also investigated in a randomly selected subgroup (n = 44). The study sample was classified according to the presence of fasting hypertriglyceridemia (≥150 mg/dL) and abdominal obesity (WHR ≥0.92 in men and ≥0.85 in women) to explore differences in parameters. Results The fasting apo B-48 levels (r = 0.404), and the WHR (r = 0.359) were independent factors contributing to the triglycerides iAUC (r2 = 0.29, P < 0.001). The triglycerides iAUC was independently associated with the apo A-V iAUC (r2 = 0.54, P < 0.01). Patients with both hypertriglyceridemia and abdominal obesity showed the most robust triglycerides and apo A-V postprandial responses. Conclusions In patients with FCH the fasting apo B-48 level is the main factor associated with postprandial lipemia. Abdominal obesity also contributes to the magnitude of the postprandial response.The triglycerides postprandial increment is the principal factor associated with the apo A-V postprandial response.
  • Tiškina, Valentina; Capligina, Valentina; Must, Külli; Berzina, Inese; Ranka, Renate; Jokelainen, Pikka (BioMed Central, 2016)
    Abstract A previously splenectomized dog from Estonia was presented with a sudden lack of appetite and discoloration of the urine. Despite supportive therapy, its condition deteriorated dramatically during 1 day. Severe thrombocytopenia and high numbers of protozoan hemoparasites were evident in blood smears, and the hematocrit dropped from 46 to 33 %. The dog was euthanized before specific antibabesial treatment was initiated. Blood samples from the dog and from two other dogs in the same household tested positive for Babesia using molecular methods, and the sequences of partial 18S rRNA gene confirmed the causative species as Babesia canis canis. The risk of severe, rapidly progressing babesiosis in splenectomized dogs merits awareness.
  • Lehtovuori, Tuomo; Kauppila, Timo; Kallio, Jouko; Raina, Marko; Suominen, Lasse; Heikkinen, Anna M (BioMed Central, 2015)
    Abstract Background In primary care, financial incentives have usually been directed to physicians because they are thought to make the key decisions in order to change the functions of a medical organization. There are no studies regarding the impact that directing these incentives to all disciplines of the care team (e.g. group bonuses for both nurses and doctors) may have, despite the low frequency with which diagnoses were being recorded for primary care visits to doctors. This study tested the effect of offering group bonuses to the care teams. Methods This was a retrospective quasi-experimental study with before-and-after settings and two control groups. In the intervention group, the mean percentage of visits to a doctor for which a diagnosis was recorded by each individual care team (mean team-based percentage of monthly visits to a doctor with recorded diagnoses) and simultaneously the same data was gathered from two different primary care settings where no team bonuses were applied. To study the sustainability of changes obtained with the group bonuses the respective data were derived from the electronic health record system for 2 years after the cessation of the intervention. The differences in the rate of marking diagnoses was analyzed with ANOVA and RM-ANOVA with appropriate post hoc tests, and the differences in the rate of change in marking diagnoses was analyzed with linear regression followed by t-test. Results The proportion of doctor visits having recorded diagnoses in the teams was about 55 % before starting to use group bonuses and 90 % after this intervention. There was no such increase in control units. The effect of the intervention weakened slightly after cessation of the group bonuses. Conclusion Group bonuses may provide a method to alter clinical practices in primary care. However, sustainability of these interventions may diminish after ceasing this type of financial incentive.
  • Savanheimo, Nora; Vehkalahti, Miira M (BioMed Central Ltd, 2014)
    Abstract Background Dental general anesthesia (DGA) is part of public dental care in Finland, but the intention is to return the patient to routine dental care. The aims of this study were to describe the details of treatments under DGA given to generally healthy children and to explore the outcome of their dental care during a 5-year follow-up, with special focus on preventive care. In particular, we examined the return of the patients to routine dental care, of which, to our knowledge, little is known. Methods Our prospective 5-year follow-up of generally healthy children (aged 0–13 years) treated under DGA by the Helsinki Public Dental Service in 2004 was based on official dental and general anesthesia documents. The statistical analyses employed chi-square tests, t-tests, Pearson’s correlation coefficient (r), Fisher’s transformation to test r ≠ 0, and logistic regression modeling. Results The most common reason for DGA was uncooperation (82%), followed by dental fear (56%). Filling therapy predominated in the treatments given under anesthesia, and the mean number of treatments per patients was 9.5 (SD = 4.2). Throughout the follow-up, 54% of the patients continued to have co-operation problems and 53% expressed dental fear; 11% of the patients received repeat DGA. The mean follow-up time was 48 (median 52) months. The postoperative review visit was actualized within 1.5 (SD = 0.8) months and the first visit to the home dental clinic of the patients in 12.0 (SD = 11.8) months for the 0–5-year-olds and in 7.2 (SD = 5.9) months for the 6–13-year-olds (p < 0.001). The mean time elapsed to the first need for treatment was 18.5 (SD = 14.1) months. During the follow-up, the mean number of treatments per patient was 5.3 (SD = 4.9); almost all patients (97%) received preventive treatment at one of two visits, but the control of dental fear remained rare. Conclusions To return to routine dental care after DGA, most of the generally healthy children in our study still needed special attention due to their uncooperation and dental fear, thus calling for a renewal of practices to treat these patients.
  • Paassilta, Marita; Kuusela, Elina; Korppi, Matti; Lemponen, Riina; Kaila, Minna; Nikkari, Seppo T (BioMed Central Ltd, 2014)
    Abstract Background Elevated serum Mead acid as a proportion of total fatty acids is an indirect marker of a deficiency of essential fatty acids (EFA). The aim of the study was to evaluate the symptoms and nutrition of food-allergic children with elevated or normal serum Mead acid. Methods Serum fatty acid compositions from 400 children were studied by clinical indications, mostly by suspicion of deficiency of EFA due to inadequate nutrition. A Mead acid level exceeding 0.21% (percentage of total fatty acids) was considered to be a specific sign of an insufficient EFA supply. From a total of 31 children with elevated Mead acid (MEADplus group), 23 (74%) had food allergy. The symptoms and dietary restrictions of this MEADplus group of food allergic children were compared to 54 age-and sex-matched controls with food allergy but normal Mead acid proportions (MEADminus group) before and 6 months after the serum fatty acid determination. Results At the beginning of the 6-month follow-up, 44% of the food allergic children in both MEADplus and MEADminus groups were on an elimination diet. These diets did not differ between the two groups and we were not able to document an association between the severity of elimination diet and elevated Mead acid proportion. However, the MEADplus children were on average more symptomatic than MEADminus children. In the MEADplus group, food allergy presented with skin symptoms in 100% (vs. 70% in the MEADminus group, p < 0.001) and with vomiting or diarrhea in 70% (vs. 44% in the MEADminus group, p < 0.05). Clinical suspicion of malnutrition resulted in increase in the use of vegetable oil and milk-free margarine in both groups from <50% to 65-74% during the follow-up. After 6 months, 64% of the MEADplus children with food allergy had been sent to a control serum fatty acid analysis. Of these children, Mead acid had declined to normal level in 69%, and remained elevated in 31%. Conclusions Severe symptoms of food allergy combined with elimination diets in children may lead to insufficient nutrition presenting with elevated serum Mead acid. Adding of supplementary polyunsaturated fat to the diet should be considered in these children.
  • Hynönen, Ulla; Kant, Ravi; Lähteinen, Tanja; Pietilä, Taija E; Beganović, Jasna; Smidt, Hauke; Uroić, Ksenija; Åvall-Jääskeläinen, Silja; Palva, Airi (BioMed Central, 2014)
    Abstract Background Adhesiveness to intestinal epithelium, beneficial immunomodulating effects and the production of pathogen-inhibitory compounds are generally considered as beneficial characteristics of probiotic organisms. We showed the potential health-promoting properties and the mechanisms of probiotic action of seven swine intestinal Lactobacillus amylovorus isolates plus the type strain (DSM 20531T) by investigating their adherence to porcine intestinal epithelial cells (IPEC-1) and mucus as well as the capacities of the strains to i) inhibit the adherence of Escherichia coli to IPEC-1 cells, ii) to produce soluble inhibitors against intestinal pathogens and iii) to induce immune signaling in dendritic cells (DCs). Moreover, the role of the L. amylovorus surface (S) –layers - symmetric, porous arrays of identical protein subunits present as the outermost layer of the cell envelope - in adherence to IPEC-1 cells was assessed using a novel approach which utilized purified cell wall fragments of the strains as carriers for the recombinantly produced S-layer proteins. Results Three of the L. amylovorus strains studied adhered to IPEC-1 cells, while four strains inhibited the adherence of E. coli, indicating additional mechanisms other than competition for binding sites being involved in the inhibition. None of the strains bound to porcine mucus. The culture supernatants of all of the strains exerted inhibitory effects on the growth of E. coli, Salmonella, Listeria and Yersinia, and a variable, strain-dependent induction was observed of both pro- and anti-inflammatory cytokines in human DCs. L. amylovorus DSM 16698 was shown to carry two S-layer-like proteins on its surface in addition to the major S-layer protein SlpA. In contrast to expectations, none of the major S-layer proteins of the IPEC-1 -adhering strains mediated bacterial adherence. Conclusions We demonstrated adhesive and significant pathogen inhibitory efficacies among the swine intestinal L. amylovorus strains studied, pointing to their potential use as probiotic feed supplements, but no independent role could be demonstrated for the major S-layer proteins in adherence to epithelial cells. The results indicate that many intestinal bacteria may coexist with and confer benefits to the host by mechanisms not attributable to adhesion to epithelial cells or mucus.
  • Tiainen, Marjaana; Poutiainen, Erja; Oksanen, Tuomas; Kaukonen, Kirsi-Maija; Pettilä, Ville; Skrifvars, Markus; Varpula, Tero; Castrén, Maaret (BioMed Central, 2015)
    Abstract Background To study functional neurologic and cognitive outcome and health-related quality of life (HRQoL) in a cohort of patients included in a randomised controlled trial on glucose control following out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation (VF) treated with therapeutic hypothermia. Methods Patients alive at 6 months after being discharged from the hospital underwent clinical neurological and extensive neuropsychological examinations. Functional outcome was evaluated with the Cerebral Performance Category scale, the modified Rankin scale and the Barthel Index. Cognitive outcome was evaluated by neuropsychological test battery including two measures of each cognitive function: cognitive speed, execution, memory, verbal skills and visuospatial performance. We also assessed quality of life with a HRQoL 15D questionnaire. Results Of 90 OHCA-VF patients included in the original trial, 57 were alive at 6 months. Of these, 52 (91%) were functionally independent and 54 (95%) lived at their previous home. Focal neurological deficits were scarce. Intact cognitive performance was observed in 20 (49%), mild to moderate deficits in 14 (34%) and severe cognitive deficits in 7 (17%) of 41 patients assessed by a neuropsychologist. Cognitive impairments were most frequently detected in executive and memory functions. HRQoL of the CA survivors was comparable to that of age- and gender matched population. Conclusions Functional outcome six months after OHCA and therapeutic hypothermia was good in the great majority of the survivors, and half of them were cognitively intact. Of note, the HRQoL of CA survivors did not differ from that of age- and gender matched population.
  • Choi, Jaeyoung; Kim, Ki-Tae; Jeon, Jongbum; Wu, Jiayao; Song, Hyeunjeong; Asiegbu, Fred O; Lee, Yong-Hwan (BioMed Central Ltd, 2014)
    Abstract Background RNA interference (RNAi) is involved in genome defense as well as diverse cellular, developmental, and physiological processes. Key components of RNAi are Argonaute, Dicer, and RNA-dependent RNA polymerase (RdRP), which have been functionally characterized mainly in model organisms. The key components are believed to exist throughout eukaryotes; however, there is no systematic platform for archiving and dissecting these important gene families. In addition, few fungi have been studied to date, limiting our understanding of RNAi in fungi. Here we present funRNA http://funrna.riceblast.snu.ac.kr/, a fungal kingdom-wide comparative genomics platform for putative genes encoding Argonaute, Dicer, and RdRP. Description To identify and archive genes encoding the abovementioned key components, protein domain profiles were determined from reference sequences obtained from UniProtKB/SwissProt. The domain profiles were searched using fungal, metazoan, and plant genomes, as well as bacterial and archaeal genomes. 1,163, 442, and 678 genes encoding Argonaute, Dicer, and RdRP, respectively, were predicted. Based on the identification results, active site variation of Argonaute, diversification of Dicer, and sequence analysis of RdRP were discussed in a fungus-oriented manner. funRNA provides results from diverse bioinformatics programs and job submission forms for BLAST, BLASTMatrix, and ClustalW. Furthermore, sequence collections created in funRNA are synced with several gene family analysis portals and databases, offering further analysis opportunities. Conclusions funRNA provides identification results from a broad taxonomic range and diverse analysis functions, and could be used in diverse comparative and evolutionary studies. It could serve as a versatile genomics workbench for key components of RNAi.
  • Katayama, Shintaro; Skoog, Tiina; Jouhilahti, Eeva-Mari; Siitonen, H. A; Nuutila, Kristo; Tervaniemi, Mari H; Vuola, Jyrki; Johnsson, Anna; Lönnerberg, Peter; Linnarsson, Sten; Elomaa, Outi; Kankuri, Esko; Kere, Juha (BioMed Central, 2015)
    Abstract Background Keratinocytes (KCs) are the most frequent cells in the epidermis, and they are often isolated and cultured in vitro to study the molecular biology of the skin. Cultured primary cells and various immortalized cells have been frequently used as skin models but their comparability to intact skin has been questioned. Moreover, when analyzing KC transcriptomes, fluctuation of polyA+ RNA content during the KCs’ lifecycle has been omitted. Results We performed STRT RNA sequencing on 10 ng samples of total RNA from three different sample types: i) epidermal tissue (split-thickness skin grafts), ii) cultured primary KCs, and iii) HaCaT cell line. We observed significant variation in cellular polyA+ RNA content between tissue and cell culture samples of KCs. The use of synthetic RNAs and SAMstrt in normalization enabled comparison of gene expression levels in the highly heterogenous samples and facilitated discovery of differences between the tissue samples and cultured cells. The transcriptome analysis sensitively revealed genes involved in KC differentiation in skin grafts and cell cycle regulation related genes in cultured KCs and emphasized the fluctuation of transcription factors and non-coding RNAs associated to sample types. Conclusions The epidermal keratinocytes derived from tissue and cell culture samples showed highly different polyA+ RNA contents. The use of SAMstrt and synthetic RNA based normalization allowed the comparison between tissue and cell culture samples and thus proved to be valuable tools for RNA-seq analysis with translational approach. Transciptomics revealed clear difference both between tissue and cell culture samples and between primary KCs and immortalized HaCaT cells.
  • Katayama, Shintaro; Skoog, Tiina; Jouhilahti, Eeva-Mari; Siitonen, H. A; Nuutila, Kristo; Tervaniemi, Mari H; Vuola, Jyrki; Johnsson, Anna; Lönnerberg, Peter; Linnarsson, Sten; Elomaa, Outi; Kankuri, Esko; Kere, Juha (BioMed Central, 2015)
    Abstract Background Keratinocytes (KCs) are the most frequent cells in the epidermis, and they are often isolated and cultured in vitro to study the molecular biology of the skin. Cultured primary cells and various immortalized cells have been frequently used as skin models but their comparability to intact skin has been questioned. Moreover, when analyzing KC transcriptomes, fluctuation of polyA+ RNA content during the KCs’ lifecycle has been omitted. Results We performed STRT RNA sequencing on 10 ng samples of total RNA from three different sample types: i) epidermal tissue (split-thickness skin grafts), ii) cultured primary KCs, and iii) HaCaT cell line. We observed significant variation in cellular polyA+ RNA content between tissue and cell culture samples of KCs. The use of synthetic RNAs and SAMstrt in normalization enabled comparison of gene expression levels in the highly heterogenous samples and facilitated discovery of differences between the tissue samples and cultured cells. The transcriptome analysis sensitively revealed genes involved in KC differentiation in skin grafts and cell cycle regulation related genes in cultured KCs and emphasized the fluctuation of transcription factors and non-coding RNAs associated to sample types. Conclusions The epidermal keratinocytes derived from tissue and cell culture samples showed highly different polyA+ RNA contents. The use of SAMstrt and synthetic RNA based normalization allowed the comparison between tissue and cell culture samples and thus proved to be valuable tools for RNA-seq analysis with translational approach. Transciptomics revealed clear difference both between tissue and cell culture samples and between primary KCs and immortalized HaCaT cells.
  • Majumder, Mamun; Kumar, Ashwini; Heckman, Caroline; Kankainen, Matti; Pesonen, Sari; Jäger , Elke; Karbach , Julia; Joensuu, Timo; Kairemo, Kalevi; Partanen, Kaarina; Alanko, Tuomo; Hemminki, Akseli; Backman, Charlotta; Dienel, Kasper; von Euler, Mikael; Hakonen, Tiina; Juhila, Juuso; Ranki, Tuuli; Vassilev, Lotta; Vuolanto, Antti; Jaderberg, Magnus (BioMed Central Ltd, 2014)
  • Kiljunen, Saija; Pajunen, Maria I; Dilks, Kieran; Storf, Stefanie; Pohlschroder, Mechthild; Savilahti, Harri (BioMed Central Ltd, 2014)
    Abstract Background Archaea share fundamental properties with bacteria and eukaryotes. Yet, they also possess unique attributes, which largely remain poorly characterized. Haloferax volcanii is an aerobic, moderately halophilic archaeon that can be grown in defined media. It serves as an excellent archaeal model organism to study the molecular mechanisms of biological processes and cellular responses to changes in the environment. Studies on haloarchaea have been impeded by the lack of efficient genetic screens that would facilitate the identification of protein functions and respective metabolic pathways. Results Here, we devised an insertion mutagenesis strategy that combined Mu in vitro DNA transposition and homologous-recombination-based gene targeting in H. volcanii. We generated an insertion mutant library, in which the clones contained a single genomic insertion. From the library, we isolated pigmentation-defective and auxotrophic mutants, and the respective insertions pinpointed a number of genes previously known to be involved in carotenoid and amino acid biosynthesis pathways, thus validating the performance of the methodologies used. We also identified mutants that had a transposon insertion in a gene encoding a protein of unknown or putative function, demonstrating that novel roles for non-annotated genes could be assigned. Conclusions We have generated, for the first time, a random genomic insertion mutant library for a halophilic archaeon and used it for efficient gene discovery. The library will facilitate the identification of non-essential genes behind any specific biochemical pathway. It represents a significant step towards achieving a more complete understanding of the unique characteristics of halophilic archaea.
  • Haukkala, Ari; Konttinen, Hanna; Hankonen, Nelli; Perola, Markus; Kääriäinen, Helena; Salomaa, Veikko (BioMed Central, 2015)
    Abstract Background The role and meaning of genetic information has grown considerably in the recent decades. We examined changes in causal beliefs about morbidity as well as the associations between causal beliefs, health behaviors and obesity, and health outcome beliefs from 1982 to 2002. Methods In five population-based risk-factor surveys (the FINRISK Studies) of individuals aged 25 to 64 years conducted from 1982 to 2002 (n = 37,503), respondents chose the most important cause of morbidity from a list of ten alternatives. Health outcome beliefs were assessed with two items. Physical inactivity and smoking status were based on self-reports and obesity was based on measured height and weight. Results The prevalence of those who endorse genetic factors as the most important cause of morbidity increased from 4% in 1982 to 10% in 1992 and remained at that level until 2002. During the study period, lack of exercise and overweight increased, whereas inappropriate diet and stress diminished as causal beliefs about morbidity. Smokers and physically inactive were more likely to endorse genetic than behavioral causes of morbidity, whereas obese respondents were more likely to choose overweight over genetic causes of morbidity. Those who endorse genetic factors as the most important cause had more pessimistic outcome beliefs about health behavior changes, but these outcome beliefs became more positive in all causal belief groups during the study period. Conclusion Despite increased public discussion of genomics, the relative proportion of those who endorse genetic factors as the most important cause of morbidity has remained low. However, within this group beliefs about benefits of health behavior changes have become more positive. This could indicate that increase in genomic health information does not lead to more negative appraisals of efficacy of lifestyle changes.
  • Haukkala, Ari; Konttinen, Hanna; Hankonen, Nelli; Perola, Markus; Kääriäinen, Helena; Salomaa, Veikko (BioMed Central, 2015)
    Abstract Background The role and meaning of genetic information has grown considerably in the recent decades. We examined changes in causal beliefs about morbidity as well as the associations between causal beliefs, health behaviors and obesity, and health outcome beliefs from 1982 to 2002. Methods In five population-based risk-factor surveys (the FINRISK Studies) of individuals aged 25 to 64 years conducted from 1982 to 2002 (n = 37,503), respondents chose the most important cause of morbidity from a list of ten alternatives. Health outcome beliefs were assessed with two items. Physical inactivity and smoking status were based on self-reports and obesity was based on measured height and weight. Results The prevalence of those who endorse genetic factors as the most important cause of morbidity increased from 4% in 1982 to 10% in 1992 and remained at that level until 2002. During the study period, lack of exercise and overweight increased, whereas inappropriate diet and stress diminished as causal beliefs about morbidity. Smokers and physically inactive were more likely to endorse genetic than behavioral causes of morbidity, whereas obese respondents were more likely to choose overweight over genetic causes of morbidity. Those who endorse genetic factors as the most important cause had more pessimistic outcome beliefs about health behavior changes, but these outcome beliefs became more positive in all causal belief groups during the study period. Conclusion Despite increased public discussion of genomics, the relative proportion of those who endorse genetic factors as the most important cause of morbidity has remained low. However, within this group beliefs about benefits of health behavior changes have become more positive. This could indicate that increase in genomic health information does not lead to more negative appraisals of efficacy of lifestyle changes.
  • Baig, Abiyad; McNally, Alan; Dunn, Steven; Paszkiewicz, Konrad H; Corander, Jukka; Manning, Georgina (BioMed Central, 2015)
    Abstract Background Campylobacter jejuni is a major zoonotic pathogen, causing gastroenteritis in humans. Invasion is an important pathogenesis trait by which C. jejuni causes disease. Here we report the genomic analysis of 134 strains to identify traits unique to hyperinvasive isolates. Methods A total of 134 C. jejuni genomes were used to create a phylogenetic tree to position the hyperinvasive strains. Comparative genomics lead to the identification of mosaic capsule regions. A pan genome approach led to the discovery of unique loci, or loci with unique alleles, to the hyperinvasive strains. Results Phylogenetic analysis showed that the hyper-invasive phenotype is a generalist trait. Despite the fact that hyperinvasive strains are only distantly related based on the whole genome phylogeny, they all possess genes within the capsule region with high identity to capsule genes from C. jejuni subsp. doylei and C. lari. In addition there were genes unique to the hyper-invasive strains with identity to non-C. jejuni genes, as well as allelic variants of mainly pathogenesis related genes already known in the other C. jejuni. In particular, the sequence of flagella genes, flgD-E and flgL were highly conserved amongst the hyper-invasive strains and divergent from sequences in other C. jejuni. A novel cytolethal distending toxin (cdt) operon was also identified as present in all hyper-invasive strains in addition to the classic cdt operon present in other C. jejuni. Conclusions Overall, the hyper-invasive phenotype is strongly linked to the presence of orthologous genes from other Campylobacter species in their genomes, notably within the capsule region, in addition to the observed association with unique allelic variants in flagellar genes and the secondary cdt operon which is unlikely under random sharing of accessory alleles in separate lineages.
  • Baig, Abiyad; McNally, Alan; Dunn, Steven; Paszkiewicz, Konrad H; Corander, Jukka; Manning, Georgina (BioMed Central, 2015)
    Abstract Background Campylobacter jejuni is a major zoonotic pathogen, causing gastroenteritis in humans. Invasion is an important pathogenesis trait by which C. jejuni causes disease. Here we report the genomic analysis of 134 strains to identify traits unique to hyperinvasive isolates. Methods A total of 134 C. jejuni genomes were used to create a phylogenetic tree to position the hyperinvasive strains. Comparative genomics lead to the identification of mosaic capsule regions. A pan genome approach led to the discovery of unique loci, or loci with unique alleles, to the hyperinvasive strains. Results Phylogenetic analysis showed that the hyper-invasive phenotype is a generalist trait. Despite the fact that hyperinvasive strains are only distantly related based on the whole genome phylogeny, they all possess genes within the capsule region with high identity to capsule genes from C. jejuni subsp. doylei and C. lari. In addition there were genes unique to the hyper-invasive strains with identity to non-C. jejuni genes, as well as allelic variants of mainly pathogenesis related genes already known in the other C. jejuni. In particular, the sequence of flagella genes, flgD-E and flgL were highly conserved amongst the hyper-invasive strains and divergent from sequences in other C. jejuni. A novel cytolethal distending toxin (cdt) operon was also identified as present in all hyper-invasive strains in addition to the classic cdt operon present in other C. jejuni. Conclusions Overall, the hyper-invasive phenotype is strongly linked to the presence of orthologous genes from other Campylobacter species in their genomes, notably within the capsule region, in addition to the observed association with unique allelic variants in flagellar genes and the secondary cdt operon which is unlikely under random sharing of accessory alleles in separate lineages.
  • Vilander, Laura M; Kaunisto, Mari A; Pettilä, Ville (BioMed Central, 2015)
    Abstract Background The risk of an individual to develop an acute kidney injury (AKI), or its severity, cannot be reliably predicted by common clinical risk factors. Whether genetic risk factors have an explanatory role poses an interesting question, however. Thus, we conducted a systematic literature review regarding genetic predisposition to AKI or outcome of AKI patients. Methods We searched Ovid SP (MEDLINE) and EMBASE databases and found 4027 references to AKI. Based on titles and abstracts, we approved 37 articles for further analysis. Nine were published only as abstracts, leaving 28 original articles in the final analysis. We extracted the first author, year of publication, study design, clinical setting, number of studied patients, patients with AKI, ethnicity of patients, studied polymorphisms, endpoints, AKI definition, phenotype, significant findings, and data for quality scoring from each article. We summarized the findings and scored the quality of articles. Results The articles were quite heterogeneous and of moderate quality (mean 6.4 of 10). Conclusions Despite different gene polymorphisms with suggested associations with development or severity or outcome of AKI, definitive conclusions would require replication of associations in independent cohort studies and, preferably a hypothesis-free study design.
  • Johnson, Nichola; Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael E; Schoemaker, Minouk J; Folkerd, Elizabeth J; Haynes, Ben P; Hopper, John L; Southey, Melissa C; Dite, Gillian S; Apicella, Carmel; Schmidt, Marjanka K; Broeks, Annegien; Van’t Veer, Laura J; Atsma, Femke; Muir, Kenneth; Lophatananon, Artitaya; Fasching, Peter A; Beckmann, Matthias W; Ekici, Arif B; Renner, Stefan P; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Burwinkel, Barbara; Marme, Frederik; Schneeweiss, Andreas; Sohn, Christof; Guénel, Pascal; Truong, Therese; Cordina, Emilie; Menegaux, Florence; Bojesen, Stig E; Nordestgaard, Børge G; Flyger, Henrik; Milne, Roger; Zamora, M P; Arias Perez, Jose I; Benitez, Javier; Bernstein, Leslie; Anton-Culver, Hoda; Ziogas, Argyrios; Clarke Dur, Christina; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Dieffenbach, Aida K; Meindl, Alfons; Heil, Joerg; Bartram, Claus R; Schmutzler, Rita K; Brauch, Hiltrud; Justenhoven, Christina; Ko, Yon-Dschun; Nevanlinna, Heli; Muranen, Taru A; Aittomäki, Kristiina; Blomqvist, Carl; Matsuo, Keitaro; Dörk, Thilo; Bogdanova, Natalia V; Antonenkova, Natalia N; Lindblom, Annika; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Chenevix-Trench, Georgia; Beesley, Jonathan; Wu, Anna H; Van den Berg, David; Tseng, Chiu-Chen; Lambrechts, Diether; Smeets, Dominiek; Neven, Patrick; Wildiers, Hans; Chang-Claude, Jenny; Rudolph, Anja; Nickels, Stefan; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Bonanni, Bernardo; Pensotti, Valeria; Couch, Fergus J; Olson, Janet E; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S; Giles, Graham G; Severi, Gianluca; Baglietto, Laura; Haiman, Chris; Simard, Jacques; Goldberg, Mark S; Labrèche, France; Dumont, Martine; Soucy, Penny; Teo, Soo; Yip, Cheng H; Phuah, Sze Y; Cornes, Belinda K; Kristensen, Vessela N; Grenaker Alnæs, Grethe; Børresen-Dale, Anne-Lise; Zheng, Wei; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Andrulis, Irene L; Knight, Julia A; Glendon, Gord; Mulligan, Anna M; Devillee, Peter; Figueroa, Jonine; Chanock, Stephen J; Lissowska, Jolanta; Sherman, Mark E; Hall, Per; Schoof, Nils; Hooning, Maartje; Hollestelle, Antoinette; Oldenburg, Rogier A; Tilanus-Linthorst, Madeleine; Liu, Jianjun; Cox, Angie; Brock, Ian W; Reed, Malcolm W; Cross, Simon S; Blot, William; Signorello, Lisa B; Pharoah, Paul D; Dunning, Alison M; Shah, Mitul; Kang, Daehee; Noh, Dong-Young; Park, Sue K; Choi, Ji-Yeob; Hartman, Mikael; Miao, Hui; Lim, Wei Y; Tang, Anthony; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans U; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; McKay, James; Slager, Susan; Toland, Amanda E; Vachon, Celine; Yannoukakos, Drakoulis; Shen, Chen-Yang; Yu, Jyh-Cherng; Huang, Chiun-Sheng; Hou, Ming-Feng; González-Neira, Anna; Tessier, Daniel C; Vincent, Daniel; Bacot, Francois; Luccarini, Craig; Dennis, Joe; Michailidou, Kyriaki; Bolla, Manjeet K; Wang, Jean; Easton, Douglas F; García-Closas, Montserrat; Dowsett, Mitch; Ashworth, Alan; Swerdlow, Anthony J; Peto, Julian; dos Santos Silva, Isabel; Fletcher, Olivia (BioMed Central, 2014)
    Abstract Introduction We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years. Methods We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics. Results We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P trend = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P trend = 0.005) but not cases (P trend = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P het = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (ORhet = 0.84, 95% CI 0.75, 0.94; ORhom = 0.81, 95% CI 0.51, 1.30; P trend = 0.002) but not for those who had their menarche age ≤11 years (ORhet = 1.06, 95% CI 0.95, 1.19, ORhom = 1.07, 95% CI 0.67, 1.72; P trend = 0.29). Conclusions To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.
  • Johnson, Nichola; Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael E; Schoemaker, Minouk J; Folkerd, Elizabeth J; Haynes, Ben P; Hopper, John L; Southey, Melissa C; Dite, Gillian S; Apicella, Carmel; Schmidt, Marjanka K; Broeks, Annegien; Van’t Veer, Laura J; Atsma, Femke; Muir, Kenneth; Lophatananon, Artitaya; Fasching, Peter A; Beckmann, Matthias W; Ekici, Arif B; Renner, Stefan P; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Burwinkel, Barbara; Marme, Frederik; Schneeweiss, Andreas; Sohn, Christof; Guénel, Pascal; Truong, Therese; Cordina, Emilie; Menegaux, Florence; Bojesen, Stig E; Nordestgaard, Børge G; Flyger, Henrik; Milne, Roger; Zamora, M P; Arias Perez, Jose I; Benitez, Javier; Bernstein, Leslie; Anton-Culver, Hoda; Ziogas, Argyrios; Clarke Dur, Christina; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Dieffenbach, Aida K; Meindl, Alfons; Heil, Joerg; Bartram, Claus R; Schmutzler, Rita K; Brauch, Hiltrud; Justenhoven, Christina; Ko, Yon-Dschun; The GENICA (Gene Environment Interaction and Breast Cancer in Germany) Network; Nevanlinna, Heli; Muranen, Taru A; Aittomäki, Kristiina; Blomqvist, Carl; Matsuo, Keitaro; Dörk, Thilo; Bogdanova, Natalia V; Antonenkova, Natalia N; Lindblom, Annika; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Chenevix-Trench, Georgia; Beesley, Jonathan; kConFab Investigators; Australian Ovarian Cancer Study Group; Wu, Anna H; Van den Berg, David; Tseng, Chiu-Chen; Lambrechts, Diether; Smeets, Dominiek; Neven, Patrick; Wildiers, Hans; Chang-Claude, Jenny; Rudolph, Anja; Nickels, Stefan; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Bonanni, Bernardo; Pensotti, Valeria; Couch, Fergus J; Olson, Janet E; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S; Giles, Graham G; Severi, Gianluca; Baglietto, Laura; Haiman, Chris; Simard, Jacques; Goldberg, Mark S; Labrèche, France; Dumont, Martine; Soucy, Penny; Teo, Soo; Yip, Cheng H; Phuah, Sze Y; Cornes, Belinda K; Kristensen, Vessela N; Grenaker Alnæs, Grethe; Børresen-Dale, Anne-Lise; Zheng, Wei; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Andrulis, Irene L; Knight, Julia A; Glendon, Gord; Mulligan, Anna M; Devillee, Peter; Figueroa, Jonine; Chanock, Stephen J; Lissowska, Jolanta; Sherman, Mark E; Hall, Per; Schoof, Nils; Hooning, Maartje; Hollestelle, Antoinette; Oldenburg, Rogier A; Tilanus-Linthorst, Madeleine; Liu, Jianjun; Cox, Angie; Brock, Ian W; Reed, Malcolm WR; Cross, Simon S; Blot, William; Signorello, Lisa B; Pharoah, Paul DP; Dunning, Alison M; Shah, Mitul; Kang, Daehee; Noh, Dong-Young; Park, Sue K; Choi, Ji-Yeob; Hartman, Mikael; Miao, Hui; Lim, Wei Y; Tang, Anthony; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans U; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; McKay, James; Slager, Susan; Toland, Amanda E; Vachon, Celine; Yannoukakos, Drakoulis; Shen, Chen-Yang; Yu, Jyh-Cherng; Huang, Chiun-Sheng; Hou, Ming-Feng; González-Neira, Anna; Tessier, Daniel C; Vincent, Daniel; Bacot, Francois; Luccarini, Craig; Dennis, Joe; Michailidou, Kyriaki; Bolla, Manjeet K; Wang, Jean; Easton, Douglas F; García-Closas, Montserrat; Dowsett, Mitch; Ashworth, Alan; Swerdlow, Anthony J; Peto, Julian; dos Santos Silva, Isabel; Fletcher, Olivia (BioMed Central Ltd, 2014)
    Abstract Introduction We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years. Methods We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics. Results We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P trend = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P trend = 0.005) but not cases (P trend = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P het = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (ORhet = 0.84, 95% CI 0.75, 0.94; ORhom = 0.81, 95% CI 0.51, 1.30; P trend = 0.002) but not for those who had their menarche age ≤11 years (ORhet = 1.06, 95% CI 0.95, 1.19, ORhom = 1.07, 95% CI 0.67, 1.72; P trend = 0.29). Conclusions To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.
  • Ollikainen, Miina; Ismail, Khadeeja; Gervin, Kristina; Kyllönen, Anjuska; Hakkarainen, Antti; Lundbom, Jesper; Järvinen, Elina A; Harris, Jennifer R; Lundbom, Nina; Rissanen, Aila; Lyle, Robert; Pietiläinen, Kirsi H; Kaprio, Jaakko (BioMed Central, 2015)
    Abstract Background The current epidemic of obesity and associated diseases calls for swift actions to better understand the mechanisms by which genetics and environmental factors affect metabolic health in humans. Monozygotic (MZ) twin pairs showing discordance for obesity suggest that epigenetic influences represent one such mechanism. We studied genome-wide leukocyte DNA methylation variation in 30 clinically healthy young adult MZ twin pairs discordant for body mass index (BMI; average within-pair BMI difference: 5.4 ± 2.0 kg/m2). Results There were no differentially methylated cytosine-guanine (CpG) sites between the co-twins discordant for BMI. However, stratification of the twin pairs based on the level of liver fat accumulation revealed two epigenetically highly different groups. Significant DNA methylation differences (n = 1,236 CpG sites (CpGs)) between the co-twins were only observed if the heavier co-twins had excessive liver fat (n = 13 twin pairs). This unhealthy pattern of obesity was coupled with insulin resistance and low-grade inflammation. The differentially methylated CpGs included 23 genes known to be associated with obesity, liver fat, type 2 diabetes mellitus (T2DM) and metabolic syndrome, and potential novel metabolic genes. Differentially methylated CpG sites were overrepresented at promoters, insulators, and heterochromatic and repressed regions. Based on predictions by overlapping histone marks, repressed and weakly transcribed sites were significantly more often hypomethylated, whereas sites with strong enhancers and active promoters were hypermethylated. Further, significant clustering of differentially methylated genes in vitamin, amino acid, fatty acid, sulfur, and renin-angiotensin metabolism pathways was observed. Conclusions The methylome in leukocytes is altered in obesity associated with metabolic disturbances, and our findings indicate several novel candidate genes and pathways in obesity and obesity-related complications.