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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.
  • 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.
  • 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.
  • 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.
  • 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.
  • Arason, Adalgeir; Gunnarsson, Haukur; Johannesdottir, Gudrun; Jonasson, Kristjan; Bendahl, Pär-Ola; Gillanders, Elizabeth M; Agnarsson, Bjarni A; Jönsson, Göran; Pylkäs, Katri; Mustonen, Aki; Heikkinen, Tuomas; Aittomäki, Kristiina; Blomqvist, Carl; Melin, Beatrice; Johannsson, Oskar TH; Møller, Pål; Winqvist, Robert; Nevanlinna, Heli; Borg, Åke; Barkardottir, Rosa B (BioMed Central Ltd, 2010)
    Abstract Introduction: A significant proportion of high-risk breast cancer families are not explained by mutations in known genes. Recent genome-wide searches (GWS) have not revealed any single major locus reminiscent of BRCA1 and BRCA2, indicating that still unidentified genes may explain relatively few families each or interact in a way obscure to linkage analyses. This has drawn attention to possible benefits of studying populations where genetic heterogeneity might be reduced. We thus performed a GWS for linkage on nine Icelandic multiple-case non-BRCA1/2 families of desirable size for mapping highly penetrant loci. To follow up suggestive loci, an additional 13 families from other Nordic countries were genotyped for selected markers. Methods: GWS was performed using 811 microsatellite markers providing about five centiMorgan (cM) resolution. Multipoint logarithm of odds (LOD) scores were calculated using parametric and nonparametric methods. For selected markers and cases, tumour tissue was compared to normal tissue to look for allelic loss indicative of a tumour suppressor gene. Results: The three highest signals were located at chromosomes 6q, 2p and 14q. One family contributed suggestive LOD scores (LOD 2.63 to 3.03, dominant model) at all these regions, without consistent evidence of a tumour suppressor gene. Haplotypes in nine affected family members mapped the loci to 2p23.2 to p21, 6q14.2 to q23.2 and 14q21.3 to q24.3. No evidence of a highly penetrant locus was found among the remaining families. The heterogeneity LOD (HLOD) at the 6q, 2p and 14q loci in all families was 3.27, 1.66 and 1.24, respectively. The subset of 13 Nordic families showed supportive HLODs at chromosome 6q (ranging from 0.34 to 1.37 by country subset). The 2p and 14q loci overlap with regions indicated by large families in previous GWS studies of breast cancer. Conclusions: Chromosomes 2p, 6q and 14q are candidate sites for genes contributing together to high breast cancer risk. A polygenic model is supported, suggesting the joint effect of genes in contributing to breast cancer risk to be rather common in non-BRCA1/2 families. For genetic counselling it would seem important to resolve the mode of genetic interaction.
  • Jönsson, Göran; Staaf, Johan; Vallon-Christersson, Johan; Ringnér, Markus; Holm, Karolina; Hegardt, Cecilia; Gunnarsson, Haukur; Fagerholm, Rainer; Strand, Carina; Agnarsson, Bjarni A; Kilpivaara, Outi; Luts, Lena; Heikkilä, Päivi; Aittomäki, Kristiina; Blomqvist, Carl; Loman, Niklas; Malmström, Per; Olsson, Håkan; Th Johannsson, Oskar; Arason, Adalgeir; Nevanlinna, Heli; Barkardottir, Rosa B; Borg, Åke (BioMed Central Ltd, 2010)
    Abstract Introduction Breast cancer is a profoundly heterogeneous disease with respect to biologic and clinical behavior. Gene-expression profiling has been used to dissect this complexity and to stratify tumors into intrinsic gene-expression subtypes, associated with distinct biology, patient outcome, and genomic alterations. Additionally, breast tumors occurring in individuals with germline BRCA1 or BRCA2 mutations typically fall into distinct subtypes. Methods We applied global DNA copy number and gene-expression profiling in 359 breast tumors. All tumors were classified according to intrinsic gene-expression subtypes and included cases from genetically predisposed women. The Genomic Identification of Significant Targets in Cancer (GISTIC) algorithm was used to identify significant DNA copy-number aberrations and genomic subgroups of breast cancer. Results We identified 31 genomic regions that were highly amplified in > 1% of the 359 breast tumors. Several amplicons were found to co-occur, the 8p12 and 11q13.3 regions being the most frequent combination besides amplicons on the same chromosomal arm. Unsupervised hierarchical clustering with 133 significant GISTIC regions revealed six genomic subtypes, termed 17q12, basal-complex, luminal-simple, luminal-complex, amplifier, and mixed subtypes. Four of them had striking similarity to intrinsic gene-expression subtypes and showed associations to conventional tumor biomarkers and clinical outcome. However, luminal A-classified tumors were distributed in two main genomic subtypes, luminal-simple and luminal-complex, the former group having a better prognosis, whereas the latter group included also luminal B and the majority of BRCA2-mutated tumors. The basal-complex subtype displayed extensive genomic homogeneity and harbored the majority of BRCA1-mutated tumors. The 17q12 subtype comprised mostly HER2-amplified and HER2-enriched subtype tumors and had the worst prognosis. The amplifier and mixed subtypes contained tumors from all gene-expression subtypes, the former being enriched for 8p12-amplified cases, whereas the mixed subtype included many tumors with predominantly DNA copy-number losses and poor prognosis. Conclusions Global DNA copy-number analysis integrated with gene-expression data can be used to dissect the complexity of breast cancer. This revealed six genomic subtypes with different clinical behavior and a striking concordance to the intrinsic subtypes. These genomic subtypes may prove useful for understanding the mechanisms of tumor development and for prognostic and treatment prediction purposes.
  • Nurminen, Janne; Puustinen, Juha; Lähteenmäki, Ritva; Vahlberg, Tero; Lyles, Alan; Partinen, Markku; Räihä, Ismo; Neuvonen, Pertti J; Kivelä, Sirkka-Liisa (BioMed Central Ltd, 2014)
    Abstract Background Benzodiazepines and related drugs affect physical functioning negatively and increase fall and fracture risk. As impaired muscle strength and balance are risk factors for falls, we examined the effects of hypnotic withdrawal on handgrip strength and balance in older adult outpatients during and after long-term use of temazepam, zopiclone and zolpidem (here collectively referred to as “benzodiazepines”). Methods Eighty-nine chronic users (59 women, 30 men) of temazepam, zopiclone or zolpidem aged ≥55 years participated in a benzodiazepine withdrawal study. Individual physician-directed withdrawal was performed gradually over a one-month period and participants were followed up to six months. Handgrip strength was assessed using a handheld dynamometer, and balance using the Short Berg’s Balance Scale during the period of benzodiazepine use (baseline), and at 1, 2, 3 weeks, and 1, 2 and 6 months after initiating withdrawal. Withdrawal outcome and persistence were determined by plasma benzodiazepine-determinations at baseline and at four weeks (“short-term withdrawers”, n = 69; “short-term non-withdrawers”, n = 20), and by interviews at six months (“long-term withdrawers”, n = 34; “long-term non-withdrawers”, n = 55). Also most of the non-withdrawers markedly reduced their benzodiazepine use. Results Within three weeks after initiating withdrawal, handgrip strength improved significantly (P ≤ 0.005) compared to baseline values. Among women, long-term withdrawers improved their handgrip strength both when compared to their baseline values (P = 0.001) or to non-withdrawers (P =0.004). In men, improvement of handgrip strength from baseline was not significantly better in withdrawers than in non-withdrawers. However, men did improve their handgrip strength values compared to baseline (P = 0.002). Compared to balance test results at baseline, withdrawers improved starting from the first week after withdrawal initiation. There was, however, only a borderline difference (P = 0.054) in balance improvement between the long-term withdrawers and long-term non-withdrawers. Of note, the non-withdrawers tended to improve their handgrip strength and balance compared to baseline values, in parallel with their reduced benzodiazepine use. Conclusions Withdrawal from long-term use of benzodiazepines can rapidly improve muscle strength and balance. Our results encourage discontinuing benzodiazepine hypnotics, particularly in older women who are at a high risk of falling and sustaining fractures. Trial registration EU Clinical Trials Register: EudraCT2008000679530. Registered 31 October 2008
  • Kvehaugen, Anne S; Melien, Øyvind; Holmen, Oddgeir L; Laivuori, Hannele; Dechend, Ralf; Staff, Anne C (BioMed Central Ltd, 2014)
    Abstract Background Preeclampsia is associated with an increased risk of hypertension later in life. The regulator of G protein signaling 2 negatively regulates several vasoconstrictors. We recently demonstrated an association between preeclampsia and the CG or GG genotype of the C1114G polymorphism (rs4606) of the regulator of G protein signaling 2 gene. Here, we examined the polymorphism with respect to the development of hypertension after pregnancy. Methods We genotyped 934 women on average 15.1 years after preeclampsia and 2011 age matched women with previous normotensive pregnancy. All women in this study were retrospectively recruited from the Nord-Trøndelag Health Study (HUNT2). Information from HUNT2 was linked to the Medical Birth Registry of Norway to identify women with a history of preeclampsia and women without a history of preeclampsia. Results No significant association was found between hypertension (blood pressure ≥140/90 mmHg and/or taking antihypertensive drugs) and the polymorphism in crude analysis (OR (95% CI): CG genotype: 1.07 (0.90-1.27); GG genotype: 1.23 (0.90-1.67)). However, in a minimally adjusted model (age and BMI adjusted), a significant association between the GG genotype and hypertension was found (OR (95% CI): 1.49 (1.05-2.11)). This association remained significant also after adjustment for a history of preeclampsia (OR (95% CI): 1.46 (1.02-2.09)), but not in a model adjusted for multiple other variables (OR (95% CI): 1.26 (0.82-1.94)). In multivariate, but not in crude, analysis, the GG genotype of rs4606 (OR (95% CI): 1.93 (1.05-3.53)) was significantly and independently associated with severe hypertension later in life, defined as systolic blood pressure ≥160 mmHg (stage 2 hypertension) and/or taking antihypertensive drugs. A significant association was also found for the merged CG and GG genotypes (OR (95% CI): 1.43 (1.02-2.00)). Moreover, an interaction with physical activity was found. A history of preeclampsia was a significant and independent predictor of either definition of hypertension, both in crude and adjusted analyses. Conclusion Women carrying the rs4606 CG or GG genotype are at elevated risk for developing hypertension after delivery. Physical activity may interact with the association. Preeclampsia remains an independent risk factor for subsequent hypertension after adjusting for this polymorphism and classical CVD risk factors.
  • Akl, Elie A; Kahale, Lara A; Agarwal, Arnav; Al-Matari, Nada; Ebrahim, Shanil; Alexander, Paul E; Briel, Matthias; Brignardello-Petersen, Romina; Busse, Jason W; Diab, Batoul; Iorio, Alfonso; Kwong, Joey; Li, Ling; Lopes, Luciane C; Mustafa, Reem; Neumann, Ignacio; Tikkinen, Kari AO; Vandvik, Per O; Zhang, Yuqing; Alonso-Coello, Pablo; Guyatt, Gordon (BioMed Central Ltd, 2014)
    Abstract Background There is no consensus on how authors conducting meta-analysis should deal with trial participants with missing outcome data. The objectives of this study are to assess in Cochrane and non-Cochrane systematic reviews: (1) which categories of trial participants the systematic review authors consider as having missing participant data (MPD), (2) how trialists reported on participants with missing outcome data in trials, (3) whether systematic reviewer authors actually dealt with MPD in their meta-analyses of dichotomous outcomes consistently with their reported methods, and (4) the impact of different methods of dealing with MPD on pooled effect estimates in meta-analyses of dichotomous outcomes. Methods/Design We will conduct a methodological study of Cochrane and non-Cochrane systematic reviews. Eligible systematic reviews will include a group-level meta-analysis of a patient-important dichotomous efficacy outcome, with a statistically significant effect estimate. Teams of two reviewers will determine eligibility and subsequently extract information from each eligible systematic review in duplicate and independently, using standardized, pre-piloted forms. The teams will then use a similar process to extract information from the trials included in the meta-analyses of interest. We will assess first which categories of trial participants the systematic reviewers consider as having MPD. Second, we will assess how trialists reported on participants with missing outcome data in trials. Third, we will compare what systematic reviewers report having done, and what they actually did, in dealing with MPD in their meta-analysis. Fourth, we will conduct imputation studies to assess the effects of different methods of dealing with MPD on the pooled effect estimates of meta-analyses. We will specifically calculate for each method (1) the percentage of systematic reviews that lose statistical significance and (2) the mean change of effect estimates across systematic reviews. Discussion The impact of different methods of dealing with MPD on pooled effect estimates will help judge the associated risk of bias in systematic reviews. Our findings will inform recommendations regarding what assumptions for MPD should be used to test the robustness of meta-analytical results.
  • Mikonranta, Lauri; Mappes, Johanna; Kaukoniitty, Minna; Freitak, Dalial (BioMed Central Ltd, 2014)
    Abstract Background Previous exposure to a pathogen can help organisms cope with recurring infection. This is widely recognised in vertebrates, but increasing occasions are also being reported in invertebrates where this phenomenon is referred to as immune priming. However, the mechanisms that allow acquired pathogen resistance in insects remain largely unknown. Results We studied the priming of bacterial resistance in the larvae of the tiger moth, Parasemia plantaginis using two gram-negative bacteria, a pathogenic Serratia marcescens and a non-pathogenic control, Escherichia coli. A sublethal oral dose of S. marcescens provided the larvae with effective protection against an otherwise lethal septic infection with the same pathogen five days later. At the same time, we assessed three anti-bacterial defence mechanisms from the larvae that had been primarily exposed to the bacteria via contaminated host plant. Results showed that S. marcescens had induced a higher amount of reactive oxygen species (ROS) in the larval haemolymph, possibly protecting the host from the recurring infection. Conclusions Our study supports the growing evidence of immune priming in insects. It shows that activation of the protective mechanism requires a specific induction, rather than a sheer exposure to any gram-negative bacteria. The findings indicate that systemic pathogen recognition happens via the gut, and suggest that persistent loitering of immune elicitors or anti-microbial molecules are a possible mechanism for the observed prophylaxis. The self-harming effects of ROS molecules are well known, which indicates a potential cost of increased resistance. Together these findings could have important implications on the ecological and epidemiological processes affecting insect and pathogen populations.
  • Laurila, Kirsti; Autio, Reija; Kong, Lingjia; Närvä, Elisa; Hussein, Samer; Otonkoski, Timo; Lahesmaa, Riitta; Lähdesmäki, Harri (BioMed Central Ltd, 2014)
    Abstract Background Human genomic variations, including single nucleotide polymorphisms (SNPs) and copy number variations (CNVs), are associated with several phenotypic traits varying from mild features to hereditary diseases. Several genome-wide studies have reported genomic variants that correlate with gene expression levels in various tissue and cell types. Results We studied human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) measuring the SNPs and CNVs with Affymetrix SNP 6 microarrays and expression values with Affymetrix Exon microarrays. We computed the linear relationships between SNPs and expression levels of exons, transcripts and genes, and the associations between gene CNVs and gene expression levels. Further, for a few of the resulted genes, the expression value was associated with both CNVs and SNPs. Our results revealed altogether 217 genes and 584 SNPs whose genomic alterations affect the transcriptome in the same cells. We analyzed the enriched pathways and gene ontologies within these groups of genes, and found out that the terms related to alternative splicing and development were enriched. Conclusions Our results revealed that in the human pluripotent stem cells, the expression values of several genes, transcripts and exons were affected due to the genomic variation.
  • Lappalainen, Anu K; Vaittinen, Elina; Junnila, Jouni; Laitinen-Vapaavuori, Outi (BioMed Central Ltd, 2014)
    Abstract Background Intervertebral disc disease (IDD) is a very common neurological disease, Dachshunds being the breed most often affected. In this breed, IDD has a hereditary background and is associated with intervertebral disc calcification (IDC), an indicator of severe intervertebral disc degeneration. In Finland, spinal radiography is used, when screening for IDC before breeding Dachshunds. We evaluated the association between IDC and IDD in Finnish Dachshunds radiographically screened for IDC. A questionnaire was sent to owners of 193 radiographically screened Dachshunds aged at least ten years. Clinical signs indicative of IDD were compared with IDC grade (grade 0 = no calcifications, grade 1 = 1 – 2 calcifications, grade 2 = 3 – 4 calcifications and grade 3 = 5 or more calcifications) and with age at the time of the radiographic examination. The diagnosis of IDD was confirmed by a veterinarian. Results IDD was common in the study population with 31% of dogs being affected. IDD and IDC were clearly connected (P < 0.001); IDD was rare in dogs with no calcifications (grade 0) and common in dogs with severe IDC (grade 3). The IDC grade was strongly positively associated with frequency of back pain periods (P < 0.001), and dogs with IDC grade 3 had frequent periods of pain. Reluctance to jump onto a sofa had a strong positive association with back pain. No association existed between age of the dog at the time of the radiographic examination and clinical signs indicative of IDD. Conclusions Radiographically detected IDC and IDD are common in Finnish Dachshunds and are strongly associated with one another. Spinal radiography is an appropriate screening tool for breeders attempting to diminish IDC and IDD in Dachshunds. A breeding program that screens dogs and selects against IDC can be expected to reduce the occurrence of IDD in future. Twenty-four to 48 months of age is a suitable age for screening.
  • Lokki, A I; Järvelä, Irma; Israelsson, Elisabeth; Maiga, Bakary; Troye-Blomberg, Marita; Dolo, Amagana; Doumbo, Ogobara K; Meri, Seppo; Holmberg, Ville (BioMed Central Ltd, 2011)
    Abstract Background Fulani are a widely spread African ethnic group characterized by lower susceptibility to Plasmodium falciparum, clinical malaria morbidity and higher rate of lactase persistence compared to sympatric tribes. Lactase non-persistence, often called lactose intolerance, is the normal condition where lactase activity in the intestinal wall declines after weaning. Lactase persistence, common in Europe, and in certain African people with traditions of raising cattle, is caused by polymorphisms in the enhancer region approximately 14 kb upstream of the lactase gene. Methods To evaluate the relationship between malaria and lactase persistence genotypes, a 400 bp region surrounding the main European C/T-13910 polymorphism upstream of the lactase gene was sequenced. DNA samples used in the study originated from 162 Fulani and 79 Dogon individuals from Mali. Results Among 79 Dogon only one heterozygote of the lactase enhancer polymorphism was detected, whereas all others were homozygous for the ancestral C allele. Among the Fulani, the main European polymorphism at locus C/T-13910 was by far the most common polymorphism, with an allele frequency of 37%. Three other single-nucleotide polymorphisms were found with allele frequencies of 3.7%, 1.9% and 0.6% each. The novel DNA polymorphism T/C-13906 was seen in six heterozygous Fulani. Among the Fulani with lactase non-persistence CC genotypes at the C/T-13910 locus, 24% had malaria parasites detectable by microscopy compared to 18% for lactase persistent genotypes (P = 0.29). Pooling the lactase enhancer polymorphisms to a common presumptive genotype gave 28% microscopy positives for non-persistent and 17% for others (P = 0.11). Conclusions Plasmodium falciparum parasitaemia in asymptomatic Fulani is more common in individuals with lactase non-persistence genotypes, but this difference is not statistically significant. The potential immunoprotective properties of dietary cow milk as a reason for the partial malaria resistance of Fulani warrant further investigation.
  • Tanislav, Christian; Grittner, Ulrike; Misselwitz, Bjoern; Jungehuelsing, Gerhard Jan; Enzinger, Christian; von Sarnowski, Bettina; Putaala, Jukka; Kaps, Manfred; Kropp, Peter; Rolfs, Arndt; Tatlisumak, Turgut; Fazekas, Franz; Kolodny, Edwin; Norrving, Bo (BioMed Central Ltd, 2014)
    Abstract Background Translating knowledge derived from medical research into the clinical setting is dependent on the representativeness of included patients. Therefore we compared baseline data of patients included in a recent large study addressing young stroke in comparison to a large representative stroke registry. Methods We analysed baseline data of 5023 patients (age 18-55 years) with an acute cerebrovascular event included in the sifap1 (Stroke in Young Fabry Patients) study. For comparison 17007 stroke patients (age 18-55 years) documented (2004-2010) in a statutory stroke registry of the Institute of Quality Assurance Hesse of the Federal State of Hesse (GQH), Germany. Results Among 17007 juvenile (18-55 years) patients identified in the GQH registry 15997 had an ischaemic stroke or TIA (91%) or an intracranial haemorrhage (9%). In sifap1 5023 subjects were included. Sex distribution was comparable (men: 59% sifap1 versus 60.5% GQH) whereas age differed between the groups: median age was 46 years in sifap1 versus 49 years in GQH. Slightly higher percentages for diabetes mellitus and hypertension in the GQH registry were noted. There were no differences in stroke severity as assessed by NIHSS (median 3) and mRS (median 2). In patients with ischaemic stroke or TIA (n = 4467 sifap1; n = 14522 GQH) higher rates of strokes due to small artery occlusion and atherosclerosis occurred in older age groups; cardioembolism and strokes of other determined cause occurred more frequently in younger patients. Conclusions The comparison of baseline characteristics between the sifap1 study and the GQH registry revealed differences mainly determined by age.
  • Tommiska, Johanna; Sorensen, Kaspar; Aksglaede, Lise; Koivu, Rosanna; Puhakka, Lea; Juul, Anders; Raivio, Taneli (BioMed Central Ltd, 2011)
    Abstract Background Pubertal timing is a strongly heritable trait, but no single puberty gene has been identified. Thus, the genetic background of idiopathic central precocious puberty (ICPP) is poorly understood. Overall, the genetic modulation of pubertal onset most likely arises from the additive effect of multiple genes, but also monogenic causes of ICPP probably exist, as cases of familial ICPP have been reported. Mutations in KISS1 and KISSR, coding for kisspeptin and its receptor, involved in GnRH secretion and puberty onset, have been suggested causative for monogenic ICPP. Variation in LIN28B was associated with timing of puberty in genome-wide association (GWA) studies. LIN28B is a human ortholog of the gene that controls, through microRNAs, developmental timing in C. elegans. In addition, Lin28a transgenic mice manifest the puberty phenotypes identified in the human GWAS. Thus, both LIN28B and LIN28A may have a role in pubertal development and are good candidate genes for monogenic ICPP. Methods Thirty girls with ICPP were included in the study. ICPP was defined by pubertal onset before 8 yrs of age, and a pubertal LH response to GnRH testing. The coding regions of LIN28B, LIN28A, KISS1, and KISS1R were sequenced. The missense change in LIN28B was also screened in 132 control subjects. Results No rare variants were detected in KISS1 or KISS1R in the 30 subjects with ICPP. In LIN28B, one missense change, His199Arg, was found in one subject with ICPP. However, this variant was also detected in one of the 132 controls. No variation in LIN28A was found. Conclusions We did not find any evidence that mutations in LIN28B or LIN28A would underlie ICPP. In addition, we confirmed that mutations in KISS1 and KISS1R are not a common cause for ICPP.
  • Raj, R; Kivisaari, R; Siironen, J; SkrifVars, M (BioMed Central Ltd, 2014)
  • Rodger, Marc A; Langlois, Nicole J; de Vries, Johanna IP; Rey, Évelyne; Gris, Jean-Christophe; Martinelli, Ida; Schleussner, Ekkehard; Ramsay, Timothy; Mallick, Ranjeeta; Skidmore, Becky; Middeldorp, Saskia; Bates, Shannon; Petroff, David; Bezemer, Dick; van Hoorn, Marion E; Abheiden, Carolien NH; Perna, Annalisa; de Jong, Paulien; Kaaja, Risto (BioMed Central Ltd, 2014)
    Abstract Background Placenta-mediated pregnancy complications include pre-eclampsia, late pregnancy loss, placental abruption, and the small-for-gestational age newborn. They are leading causes of maternal, fetal, and neonatal morbidity and mortality in developed nations. Women who have experienced these complications are at an elevated risk of recurrence in subsequent pregnancies. However, despite decades of research no effective strategies to prevent recurrence have been identified, until recently. We completed a pooled summary-based meta-analysis that strongly suggests that low-molecular-weight heparin reduces the risk of recurrent placenta-mediated complications. The proposed individual patient data meta-analysis builds on this successful collaboration. The project is called AFFIRM, An individual patient data meta-analysis oF low-molecular-weight heparin For prevention of placenta-medIated pRegnancy coMplications. Methods/Design We conducted a systematic review to identify randomized controlled trials with a low-molecular-weight heparin intervention for the prevention of recurrent placenta-mediated pregnancy complications. Investigators and statisticians representing eight trials met to discuss the outcomes and analysis plan for an individual patient data meta-analysis. An additional trial has since been added for a total of nine eligible trials. The primary analyses from the original trials will be replicated for quality assurance prior to recoding the data from each trial and combining it into a common dataset for analysis. Using the anonymized combined data we will conduct logistic regression and subgroup analyses aimed at identifying which women with previous pregnancy complications benefit most from treatment with low-molecular-weight heparin during pregnancy. Discussion The goal of the proposed individual patient data meta-analysis is a thorough estimation of treatment effects in patients with prior individual placenta-mediated pregnancy complications and exploration of which complications are specifically prevented by low-molecular-weight heparin. Systematic review registration PROSPERO (International Prospective Registry of Systematic Reviews) 23 December 2013, CRD42013006249