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  • 1
    Publikationsdatum: 2012-03-09
    Beschreibung: This study assessed the concentrations of cadmium in the gills, livers and muscles of a commercially important tilapia fish (Sarotherodon melanotheron) from Aby Lagoon in Adiaké, Côte d’Ivoire, between January and December, 2010. The organisms were grouped into two composite samples (juvenile and adult) of five individuals. Levels of cadmium were determined in tissues using Perkin-Elmer (AAnalyst 200) Atomic Absorption Spectrophotometry (AAS) after a digestion method. Fish muscle appeared to have a significantly higher tendency to accumulate cadmium (1.19–5.18 µg/g dw) while gills and livers had minimum concentrations (0.07–1.32 and 0.12–1.25 µg/g dw). This study has revealed that the concentrations of Cd in Sarotherodon melanotheron muscle tissue were above the maximum acceptable concentrations for human consumption, thus precautions need to be taken in order to prevent future contamination.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2012-03-15
    Beschreibung: Monitoring of progress towards the Millennium Development Goal (MDG) drinking water target relies on classification of water sources as “improved” or “unimproved” as an indicator for water safety. We adjust the current Joint Monitoring Programme (JMP) estimate by accounting for microbial water quality and sanitary risk using the only-nationally representative water quality data currently available, that from the WHO and UNICEF “Rapid Assessment of Drinking Water Quality”. A principal components analysis (PCA) of national environmental and development indicators was used to create models that predicted, for most countries, the proportions of piped and of other-improved water supplies that are faecally contaminated; and of these sources, the proportions that lack basic sanitary protection against contamination. We estimate that 1.8 billion people (28% of the global population) used unsafe water in 2010. The 2010 JMP estimate is that 783 million people (11%) use unimproved sources. Our estimates revise the 1990 baseline from 23% to 37%, and the target from 12% to 18%, resulting in a shortfall of 10% of the global population towards the MDG target in 2010. In contrast, using the indicator “use of an improved source” suggests that the MDG target for drinking-water has already been achieved. We estimate that an additional 1.2 billion (18%) use water from sources or systems with significant sanitary risks. While our estimate is imprecise, the magnitude of the estimate and the health and development implications suggest that greater attention is needed to better understand and manage drinking water safety.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 3
    Publikationsdatum: 2012-03-16
    Beschreibung: Aim: To assess suicide mortality in comparison to traffic accidents and homicide deaths in Germany in the year 2010 and to compare years of life lost (YLL) due to these unnatural deaths. Methods: Mortality data were provided by the Federal Statistical Office giving death rates (related to 100,000 inhabitants) and proportions (related to 100 deaths of individuals) for suicide, traffic accidents and homicide as well as YLL data. Results: A total of 14,441 unnatural deaths (suicide, traffic accidents, homicide) were reported in 2010 in Germany. Of those, 10,021 subjects (69.4%) committed suicide, 3,942 (27.3%) died in traffic accidents, 478 (3.3%) were murdered. Suicide death rates were by far the highest, with rates for men (18.6) three times higher than for women (6.1). For both sexes, suicide rates increased with age, whereas suicide as a proportion of all causes of death was higher in younger age groups. In both sexes, suicide was the leading cause of YLL (men: 314 YLL, women: 90 YLL). Conclusions: Suicide is the leading cause of unnatural death and YLL. The sex- and age- specific patterns in suicide mortality call for different action plans to target high risk groups.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 4
    Publikationsdatum: 2012-03-16
    Beschreibung: The objective of this cross-sectional questionnaire study was to assess associations of a self-report index of sun protection habit strength with sunscreen use in sporting environments and outdoor physical activity. Participants (n = 234) in field hockey, soccer, tennis and surf sports in Queensland, Australia, completed a self-administered survey on sun protection during organized sport, and during general outdoor physical activity during 2005/2006. The sun protection habit strength index was dichotomized into two categories. Multinomial logistic regression analyses assessed the associations of low versus high sun protection habit strength with three categories of sunscreen use (no or rare use; inadequate use; and adequate use). Compared to participants with low sun protection habit strength, those with high sun protection habit strength had significantly greater odds of any sunscreen use during organized sport and during general outdoor physical activity. This association was strongest for adequate sunscreen use in both settings. In conclusion, this study suggests that the measure of sun protection habit strength is a potentially useful assessment tool for future sun protection studies.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 5
    Publikationsdatum: 2012-02-11
    Beschreibung: Micro-relief heterogeneity can lead to substantial variability in microclimate and hence niche opportunities on a small scale. We explored the relationship between plant species richness and small-scale heterogeneity of micro-relief on the subtropical island of La Palma, Canary Islands. Overall, we sampled 40 plots in laurel and pine forests at four altitudinal bands. Species richness was recorded separately for various growth forms (i.e., mosses, herbaceous and woody plants). Site conditions such as altitude, slope, aspect, and tree density were measured. Micro-relief heterogeneity was characterized by surface structure and a subsequently derived surface heterogeneity index. The effect of micro-relief heterogeneity on species richness was analysed by means of linear mixed effect models and variance partitioning. Effects of micro-relief heterogeneity on species richness varied considerably between growth forms. While moss richness was affected significantly by micro-relief heterogeneity, herbaceous and woody plants richness responded mainly to larger-scale site conditions such as aspect and tree density. Our results stress the importance of small-scale relief heterogeneity for the explanation of spatial patterns of species richness. This poses new challenges as small-scale heterogeneity is largely underrepresented, e.g. with regard to its application in species distribution models.
    Digitale ISSN: 1424-2818
    Thema: Biologie
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2012-02-11
    Beschreibung: The aim of this study was to determine the prevalence of suicidal ideation in patients who were tested for HIV-infection and whether along with their HIV status, age and gender influenced their risk for suicidal ideation. The sample consisted of 189 patients who attended a voluntary HIV counseling and testing clinic (VCT) at a general state hospital in Durban, South Africa. Their mean age at baseline was 34.2 years, with an age range of between 16–79 years. Seropositivity, age and gender were significantly associated with suicidal ideation. The majority of these patients were in the younger age group, and young males had a 1.8 times higher risk for suicidal ideation than females. Although risk factors for seropositive-related suicidal ideation can be complex and multi-factorial, this study identified a young age and male gender as important high risk factors in the sample studied. It is recommended that all, but especially young male HIV-infected patients seen at a VCT clinic be screened for suicidal ideation and that early intervention to prevent subsequent suicides or suicidal attempts be included in pre- and post-test HIV counseling.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 7
    Publikationsdatum: 2012-12-25
    Beschreibung: This article focuses on the psychosocial work environment of immigrant cleaners at a Danish workplace. Today, many cleaners working in Danish cleaning jobs are women from the established immigrant communities, but also labour migrants from the newer EU member states have found their way to the cleaning industry. Studies have drawn attention to immigrants’ low position in the cleaning industry and their increased risk of work injuries. This article is based on a case study of an intervention called “Make a Difference” designed to improve the work environment among cleaners at a multi-ethnic workplace. We used semi-structured interviews, photo logs, observation and participation to investigate how the cleaners experienced their work environment. The cleaners reported an overload of heavy work, related to the concept of a classroom’s “readiness for cleaning”, and they expressed strained social relations and communication in addition to a lack of social recognition and invisibility at the workplace, a school. We analysed these psychosocial work environmental problems by investigating the different forms of social relationships and communication within the group of cleaners, and between the cleaners and the teachers and pupils at the school. Moreover, we discussed why the intervention, based on training of language and cleaning skills and social interaction, only partially improved the cleaners’ psychosocial work environment problems. In this article, we argue that social divisions based on ethnicity between the new and the established group of cleaners, combined with their marginal position and poor work organisation at the school, reinforced the cleaners’ experiences of psychosocial work environment problems. This article suggests that increased effort towards social inclusion at work and improved work organisation, especially for the new labour migrants from newer EU-countries, should be considered.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 8
    Publikationsdatum: 2012-12-25
    Beschreibung: The risk to public health from the large number of dog stools present on streets of urban areas is cause for concern. Dog faeces may be a serious hazard because they may contain microorganisms that are both pathogenic to humans and resistant to several classes of antibiotics. The aim of this study was to evaluate the potential for zoonotic infections and for the presence of antibiotic resistant bacteria in canine faeces which contaminates the urban environment. A total of 418 canine faecal samples were collected from streets in seven areas of Bari, Southern Italy. We have isolated multi-drug resistant Enterococci and meticillin-resistant Staphylococcus aureus from these dog faecal samples. The presence of the resistant bacteria in an urban environment may represent a public health hazard which requires control measures by competent authorities. No Salmonella, Yersinia or Campylobacter species were isolated. Giardia cysts were detected in 1.9% of the samples. The predominant Enterococcus species were E. faecium (61.6%), E. gallinarum (23.3%) and E. casseliflavus (5.5%). Other species, including E. faecalis were also isolated. These strains were resistant to clindamycin (86.3%), tetracycline (65.7%), erythromycin (60.27%) and ampicillin (47.9%). High-level aminoglycoside resistance (HLAR) was found in 65.7% of enterococci. Resistance to three or more antibiotics and six or more antibiotics were observed in 67.12% and 38.4% of Enterococcus spp., respectively. Resistance to vancomycin and teicoplanin was not detected in any of the Enterococcus spp. isolated. Methicillin-resistant Staphylococcus aureus was isolated in 0.7% of the faecal samples. Canine faeces left on the streets may represent a risk factor for transmission of microorganisms and a reservoir of multidrug- resistant bacteria thus contributing to the spread of resistance genes into an urban area.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 9
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 Insulin stimulates glucose uptake through the membrane translocation of GLUT4 and GLUT1. Peroxisome proliferator-activated receptor γ (PPARγ) enhances insulin sensitivity. Here, we demonstrate that insulin stimulates GLUT4 and GLUT1 translocation, and glucose uptake, by activating the signaling pathway involving nicotinic acid adenine dinucleotide phosphate (NAADP), a calcium mobilizer, in adipocytes. We also demonstrate that PPARγ mediates insulin sensitization by enhancing NAADP production through upregulation of CD38, the only enzyme identified for NAADP synthesis. Insulin produced NAADP by both CD38-dependent and -independent pathways, whereas PPARγ produced NAADP by CD38-dependent pathway. Blocking the NAADP signaling pathway abrogated both insulin-stimulated and PPARγ-induced GLUT4 and GLUT1 translocation, thereby inhibiting glucose uptake. CD38 knockout partially inhibited insulin-stimulated glucose uptake. However, CD38 knockout completely blocked PPARγ-induced glucose uptake in adipocytes and PPARγ-mediated amelioration of glucose tolerance in diabetic mice. These results demonstrated that the NAADP signaling pathway is a critical molecular target for PPARγ-mediated insulin sensitization. Graphical abstract Highlights ► Insulin induces glucose uptake via NAADP-mediated calcium increase ► PPARγ mediates insulin sensitization by upregulating the NAADP-producing enzyme CD38 ► PPARγ agonists ameliorate glucose tolerance by CD38 upregulation
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 10
    Publikationsdatum: 2012-12-28
    Beschreibung: Available online 27 December 2012 Publication year: 2012 Source: Cell Reports Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1) at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed. Graphical abstract Highlights ► Structure of the major antigenically dominant protein of BVDV ► The overall fold of BVDV E2 shows no similarity to the class II fusion proteins ► At low pH, BVDV E2 N-terminal domain is disordered ► Entry mechanism of BVDV is probably applicable to hepatitis C virus
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 11
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Trypanosoma cruzi, the causal agent of Chagas Disease, affects more than 16 million people in Latin America. The clinical outcome of the disease results from a complex interplay between environmental factors and the genetic background of both the human host and the parasite. However, knowledge of the genetic diversity of the parasite, is currently limited to a number of highly studied loci. The availability of a number of genomes from different evolutionary lineages of T. cruzi provides an unprecedented opportunity to look at the genetic diversity of the parasite at a genomic scale. Results: Using a bioinformatic strategy, we have clustered T. cruzi sequence data available in the public domain and obtained multiple sequence alignments in which one or two alleles from the reference CL-Brener were included. These data covers 4 major evolutionary lineages (DTUs): TcI, TcII, TcIII, and the hybrid TcVI. Using these set of alignments we have identified 288,957 high quality single nucleotide polymorphisms and 1,480 indels. In a reduced re-sequencing study we were able to validate ~ 97% of high-quality SNPs identified in 47 loci. Analysis of how these changes affect encoded protein products showed a 0.77 ratio of synonymous to non-synonymous changes in the T. cruzi genome. We observed 113 changes that introduce or remove a stop codon, some causing significant functional changes, and a number of tri-allelic and tetra-allelic SNPs that could be exploited in strain typing assays. Based on an analysis of the observed nucleotide diversity we show that the T. cruzi genome contains a core set of genes that are under apparent purifying selection. Interestingly, orthologs of known druggable targets show statistically significant lower nucleotide diversity values. Conclusions: This study provides the first look at the genetic diversity of T. cruzi at a genomic scale. The analysis covers an estimated ~ 60% of the genetic diversity present in the population, providing an essential resource for future studies on the development of new drugs and diagnostics, for Chagas Disease. These data is available through the TcSNP database (http://snps.tcruzi.org).
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
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  • 12
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression by targeting mRNAs for translation repression or mRNA degradation. Although many miRNAs have been discovered and studied in human and mouse, few studies focused on porcine miRNAs, especially in genome wide. Results: Here, we adopted computational approaches including support vector machine (SVM) and homology searching to make a global scanning on the pre-miRNAs of pigs. In our study, we built the SVM-based porcine pre-miRNAs classifier with a sensitivity of 100%, a specificity of 91.2% and a total prediction accuracy of 95.6%, respectively. Moreover, 2204 novel porcine pre-miRNA candidates were found by using SVM-based pre-miRNAs classifier. Besides, 116 porcine pre-miRNA candidates were detected by homology searching. Conclusions: We identified the porcine pre-miRNA in genome-wide through computational approaches by utilizing the data sets of pigs and set up the porcine pre-miRNAs library which may provide us a global scanning on the pre-miRNAs of pigs in genome level and would benefit subsequent experimental research on porcine miRNA functional and expression analysis.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
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  • 13
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are alpha-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris) in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results: Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym) that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions: Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean and other legume hosts.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Publikationsdatum: 2012-12-28
    Beschreibung: Ecological studies of suicide and self-harm have established the importance of area variables (e.g., deprivation, social fragmentation) in explaining variations in suicide risk. However, there are likely to be unobserved influences on risk, typically spatially clustered, which can be modeled as random effects. Regression impacts may be biased if no account is taken of spatially structured influences on risk. Furthermore a default assumption of linear effects of area variables may also misstate or understate their impact. This paper considers variations in suicide outcomes for small areas across England, and investigates the impact on them of area socio-economic variables, while also investigating potential nonlinearity in their impact and allowing for spatially clustered unobserved factors. The outcomes are self-harm hospitalisations and suicide mortality over 6,781 Middle Level Super Output Areas.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 15
    Publikationsdatum: 2012-12-28
    Beschreibung: As the number of cancer survivors treated with radiation as a part of their therapy regimen is constantly increasing, so is concern about radiation-induced cancers. This increases the need for therapeutic and mitigating agents against secondary neoplasias. Development and efficacy testing of these agents requires not only extensive in vitro assessment, but also a set of reliable animal models of radiation-induced carcinogenesis. The laboratory mouse (Mus musculus) remains one of the best animal model systems for cancer research due to its molecular and physiological similarities to man, small size, ease of breeding in captivity and a fully sequenced genome. This work reviews relevant M. musculus inbred and F1 hybrid animal models and methodologies of induction of radiation-induced leukemia, thymic lymphoma, breast, and lung cancer in these models. Where available, the associated molecular pathologies are also included.
    Print ISSN: 1661-7827
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    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 16
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: The objective of the research was to evaluate the current effectiveness of Ciprofloxacin on the uropathogens prevalent in infected urines of a cross-section of patients in Karachi, Pakistan.FindingsAn observational study conducted in a private diagnostic laboratory and its branches in key areas of Karachi City from February 2010 to July 2011. A total of 2963 consecutive urine samples were cultured on chocolate agar, CLED medium and selective EMB agar. Growth of possible uropathogens was noted, and compared retrospectively with earlier lab data of suggestive urine cultures (n = 1997) recorded during January 2009 and December 2009. The isolates were identified using routine procedures and the API 20 system and evaluated for their sensitivity to ciprofloxacin by Kirby-Bauer disk diffusion method. Data was subjected to statistical analysis on SPSS version 16. Out of the present-day culture-positive urines, 2409 (80.4%) yielded gram-negative rods, and 554 (18.5%) gram-positive cocci. E.coli (43.1%) was most frequent, followed by Klebsiella pneumoniae (22.4%) and Staphylococcus aureus (15.5%). 57.2% of the Gram-negative bacteria and 48.7% of the Gram-positive isolates were resistant to ciprofloxacin. In the earlier (2009) screening, 39% of Gram-negative rods and 48% of Gram-positive cocci were indifferent to the drug. Conclusions: A decrease in bacterial susceptibility of uropathogens to ciprofloxacin, a commonly prescribed drug in our population, is underlined, occurring possibly due to overuse pressure. Empirical initial treatment with ciprofloxacin would be inadequate in more than half of UTI cases, thereby counseling increased C/S testing of urines to provide existing sensitivity data for apt drug prescription.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
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  • 17
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Data accuracy and completeness are crucial for ensuring both the correctness and epidemiological relevance of a given data set. In this study we evaluated a clinical register in the administrative district of Marburg-Biedenkopf, Germany, for these criteria. Methods: The register contained data gathered from a comprehensive integrated breast-cancer network from three hospitals that treated all included incident cases of malignant breast cancer in two distinct time periods from 1996--97 (N=389) and 2003--04 (N=488). To assess the accuracy of this data, we compared distributions of risk, prognostic, and predictive factors with distributions from established secondary databases to detect any deviations from these [prime][prime]true[prime][prime] population parameters. To evaluate data completeness, we calculated epidemiological standard measures as well as incidence-mortality-ratios (IMRs). Results: In total, 12% (13 of 109) of the variables exhibited inaccuracies: 9% (5 out of 56) in 1996--97 and 15% (8 out of 53) in 2003--04. In contrast to raw, unstandardized incidence rates, (in-) directly age-standardized incidence rates showed no systematic deviations. Our final completeness estimates were IMR=36% (1996--97) and IMR=43% (2003--04). Conclusion: Overall, the register contained accurate, complete, and correct data. Regional differences accounted for detected inaccuracies. Demographic shifts occurred. Age-standardized measures indicate an acceptable degree of completeness. The IMR method of measuring completeness was inappropriate for incidence-based data registers. For the rising number of population-based health-care networks, further methodological advancements are necessary. Correct and epidemiologically relevant data are crucial for clinical and health-policy decision-making.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
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  • 18
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Patients increasingly turn to the Internet for information on medical conditions, including clinical news and treatment options. In recent years, an online patient community has arisen alongside the rapidly expanding world of social media, or "Web 2.0." Twitter provides real-time dissemination of news, information, personal accounts and other details via a highly interactive form of social media, and has become an important online tool for patients. This medium is now considered to play an important role in the modern social community of online, "wired" cancer patients. Results: Fifty-one highly influential "power accounts" belonging to cancer patients were extracted from a dataset of 731 Twitter accounts with cancer terminology in their profiles. In accordance with previously established methodology, "power accounts" were defined as those Twitter accounts with 500 or more followers. We extracted data on the cancer patient (female) with the most followers to study the specific relationships that existed between the user and her followers, and found that the majority of the examined tweets focused on greetings, treatment discussions, and other instances of psychological support. These findings went against our hypothesis that cancer patients' tweets would be centered on the dissemination of medical information and similar "newsy" details. Conclusions: At present, there exists a rapidly evolving network of cancer patients engaged in information exchange via Twitter. This network is valuable in the sharing of psychological support among the cancer community.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
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  • 19
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    Elsevier
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 Controversy has recently arisen over the role of sirtuins in metazoan aging. In this issue of Cell Reports , Banerjee et al. demonstrate that Drosophila Sir2 is necessary for life span extension in response to dietary restriction and that its overexpression in the fat body increases the life span.
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 20
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 Inhibition of sirtuin 2 (SIRT2) deacetylase mediates protective effects in cell and invertebrate models of Parkinson’s disease and Huntington’s disease (HD). Here we report the in vivo efficacy of a brain-permeable SIRT2 inhibitor in two genetic mouse models of HD. Compound treatment resulted in improved motor function, extended survival, and reduced brain atrophy and is associated with marked reduction of aggregated mutant huntingtin, a hallmark of HD pathology. Our results provide preclinical validation of SIRT2 inhibition as a potential therapeutic target for HD and support the further development of SIRT2 inhibitors for testing in humans. Graphical abstract Highlights ► Sirtuin 2 (SIRT2) inhibition is neuroprotective in two HD mouse models ► SIRT2 inhibitor treatment markedly reduces huntingtin aggregates in HD mouse brain ► SIRT2 is a promising therapeutic target for neurological protein aggregation disorders
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 21
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Exposure to early adverse events can result in the development of later psychopathology, and is often associated with cognitive impairment. This may be due to accelerated cell aging, which can be catalogued by attritioned telomeres. Exercise enhances neurogenesis and has been proposed to buffer the effect of psychological stress on telomere length. This study aimed to investigate the impact of early developmental stress and voluntary exercise on telomere length in the ventral hippocampus (VH) and prefrontal cortex (PFC) of the rat. Forty-five male Sprague--Dawley rats were categorised into four groups: maternally separated runners (MSR), maternally separated non-runners (MSnR), non-maternally separated runners (nMSR) and non-maternally separated non-runners (nMSnR). Behavioural analyses were conducted to assess anxiety-like behaviour and memory performance in the rats, after which relative telomere length was measured using qPCR. Results: Maternally separated (MS) rats exhibited no significant differences in either anxiety levels or memory performance on the elevated-plus maze and the open field compared to non-maternally separated rats at 49 days of age. Exercised rats displayed increased levels of anxiety on the day that they were removed from the cages with attached running wheels, as well as improved spatial learning and temporal recognition memory compared to non-exercised rats. Exploratory post-hoc analyses revealed that maternally separated non-exercised rats exhibited significantly longer telomere length in the VH compared to those who were not maternally separated; however, exercise appeared to cancel this effect since there was no difference in VH telomere length between maternally separated and non-maternally separated runners. Conclusions: The increased telomere length in the VH of maternally separated non-exercised rats may be indicative of reduced cellular proliferation, which could, in turn, indicate hippocampal dysfunction. This effect on telomere length was not observed in exercised rats, indicating that voluntary exercise may buffer against the progressive changes in telomere length caused by alterations in maternal care early in life. In future, larger sample sizes will be needed to validate results obtained in the present study and obtain a more accurate representation of the effect that psychological stress and voluntary exercise have on telomere length.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 Planar cell polarity (PCP) refers to the collective orientation of cells within the epithelial plane. We show that progenitor cells forming the ducts of the embryonic pancreas express PCP proteins and exhibit an active PCP pathway. Planar polarity proteins are acquired at embryonic day 11.5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal that tridimensional organization and collective communication of cells are needed in the pancreatic epithelium in order to generate appropriate numbers of endocrine cells. Graphical abstract Highlights ► PCP proteins are restricted to progenitor cells in the embryonic pancreas ► The PCP core components Celsr2 and Celsr3 control endocrine cell differentiation ► This effect is mediated by the JNK pathway
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: Graph-based modularity analysis has emerged as an important tool to study the functional organization of biological networks. However, few methods are available to study state-dependent changes in network modularity using biological activity data. We develop a weighting scheme, based on metabolic flux data, to adjust the interaction distances in a reaction-centric graph model of a metabolic network. The weighting scheme was combined with a hierarchical module assignment algorithm featuring the preservation of metabolic cycles to examine the effects of cellular differentiation and enzyme inhibitions on the functional organization of adipocyte metabolism. Results: Our analysis found that the differences between various metabolic states primarily involved the assignment of two specific reactions in fatty acid synthesis and glycerogenesis. Our analysis also identified cyclical interactions between reactions that are robust with respect to metabolic state, suggesting possible co-regulation. Comparisons based on cyclical interaction distances between reaction pairs suggest that the modular organization of adipocyte metabolism is stable with respect to the inhibition of an enzyme, whereas a major physiological change such as cellular differentiation leads to a more substantial reorganization. Conclusion: Taken together, our results support the notion that network modularity is influenced by both the connectivity of the network's components as well as the relative engagements of the connections.
    Digitale ISSN: 1752-0509
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    facet.materialart.
    Unbekannt
    Elsevier
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 MicroRNAs (miRNAs) are small, noncoding RNAs that inhibit translation and promote mRNA decay. The levels of mature miRNAs are the result of different rates of transcription, processing, and turnover. The noncanonical polymerase Gld2 has been implicated in the stabilization of miR-122, possibly through catalyzing 3′ monoadenylation; however, there is little evidence that this relationship is one of cause and effect. Here, we biochemically characterize Gld2’s involvement in miRNA monoadenylation and its effect on miRNA stability. We find that Gld2 directly monoadenylates and stabilizes specific miRNA populations in human fibroblasts and that sensitivity to monoadenylation-induced stability depends on nucleotides in the miRNA 3′ end. These results establish a mechanism of miRNA stability and resulting posttranscriptional gene regulation. Graphical abstract Highlights ► Gld2 monoadenylates specific microRNAs (miRNAs) ► Monoadenylation stabilizes miRNA subpopulations and prolongs their activity ► Sensitivity to monoadenylation and stability depends on nucleotides in the miRNA 3′ end
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 In the cytoplasm, the correct delivery of membrane proteins is an essential and highly regulated process. The posttranslational targeting of the important tail-anchor membrane (TA) proteins has recently been under intense investigation. A specialized pathway, called the guided entry of TA proteins (GET) pathway in yeast and the transmembrane domain recognition complex (TRC) pathway in vertebrates, recognizes endoplasmic-reticulum-targeted TA proteins and delivers them through a complex series of handoffs. An early step is the formation of a complex between Sgt2/SGTA, a cochaperone with a presumed ubiquitin-like-binding domain (UBD), and Get5/UBL4A, a ubiquitin-like domain (UBL)-containing protein. We structurally characterize this UBD/UBL interaction for both yeast and human proteins. This characterization is supported by biophysical studies that demonstrate that complex formation is mediated by electrostatics, generating an interface that has high-affinity with rapid kinetics. In total, this work provides a refined model of the interplay of Sgt2 homologs in TA targeting. Graphical abstract Highlights ► Sgt2 homologs contain dimerization motifs that are novel UBDs ► The UBL of Get5 homologs has features that distinguish it from other UBLs ► Complex formation of Sgt2 and Get5 includes a conserved and dynamic interface ► The system can rapidly discriminate between other UBL pathways
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 Chimera formation after blastocyst injection or morula aggregation is the principal functional assay of the developmental potential of mouse embryonic stem cells (ESCs). This property, which demonstrates functional equivalence between ESCs and the preimplantation epiblast, is not shared by epiblast stem cell (EpiSC) lines. Here, we show that EpiSCs derived either from postimplantation embryos or from ESCs in vitro readily generate chimeras when grafted to postimplantation embryos in whole embryo culture. EpiSC derivatives integrate and differentiate to derivatives of all three embryonic germ layers and primordial germ cells. In contrast, grafted ESCs seldom proliferate in postimplantation embryos, and fail to acquire the identity of their host-derived neighbors. EpiSCs do not incorporate efficiently into embryonic day 8.5 embryos, a stage by which pluripotency has been lost. Thus, chimera formation by EpiSCs requires a permissive environment, the postimplantation epiblast, and demonstrates functional equivalence between this cell type and EpiSCs. Graphical abstract Highlights ► Epiblast stem cells (EpiSCs) form chimeras when injected into postimplantation epiblast ► Embryonic stem cells do not form postimplantation chimeras ► EpiSCs do not integrate if they are injected after gastrulation
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    facet.materialart.
    Unbekannt
    Elsevier
    Publikationsdatum: 2012-12-28
    Beschreibung: 27 December 2012 Publication year: 2012 Source: Cell Reports, Volume 2, Issue 6 An increased understanding of antitumor immunity is necessary for improving cell-based immunotherapies against human cancers. Here, we investigated the roles of two immune system-expressed microRNAs (miRNAs), miR-155 and miR-146a, in the regulation of antitumor immune responses. Our results indicate that miR-155 promotes and miR-146a inhibits interferon γ (IFNγ) responses by T cells and reduces solid tumor growth in vivo. Using a double-knockout (DKO) mouse strain deficient in both miR-155 and miR-146a, we have also identified an epistatic relationship between these two miRNAs. DKO mice had defective T cell responses and tumor growth phenotypes similar to miR-155 −/− mice. Further analysis of the T cell compartment revealed that miR-155 modulates IFNγ expression through a mechanism involving repression of Ship1. Our work reveals critical roles for miRNAs in the reciprocal regulation of CD4 + and CD8 + T cell-mediated antitumor immunity and demonstrates the dominant nature of miR-155 during its promotion of immune responses. Graphical abstract Highlights ► miR-155 promotes and miR-146a inhibits both CD4+ and CD8+ T cell antitumor responses ► DKO mice reveal epistasis between miR-155 and miR-146a during tumor immunity ► miR-155 regulation of IFNγ involves repression of its target Ship1 in T cells
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Publikationsdatum: 2012-12-28
    Beschreibung: Background: A novel herbal formulation LI10903F, alternatively known as LOWAT was developed based on its ability to inhibit adipogenesis and lipogenesis in 3T3-L1 adipocytes model. The clinical efficacy and tolerability of LI10903F were evaluated in an eight-week, randomized, double-blind, placebo-controlled, clinical trial in 50 human subjects with body mass index (BMI) between 30 and 40 kg/m2 (clinical trial registration number: ISRCTN37381706). Participants were randomly assigned to either a placebo or LI10903F group. Subjects in the LI10903F group received 300 mg of herbal formulation thrice daily, while subjects in the placebo group received 300 mg of placebo capsules thrice daily. All subjects were provided a standard diet (2,000 kcal daily) and participated in a moderate exercise of 30 min walk for five days a week. Additionally, the safety of this herbal formulation was evaluated by a series of acute, sub-acute toxicity and genotoxicity studies in animals and cellular models. Results: After eight weeks of supplementation, statistically significant net reductions in body weight (2.49 kg; p=0.00005) and BMI (0.96 kg/m2; p=0.00004) were observed in the LI10903F group versus placebo group. Additionally, significant increase in serum adiponectin concentration (p=0.0076) and significant decrease in serum ghrelin concentration (p=0.0066) were found in LI10903F group compared to placebo group. Adverse events were mild and were equally distributed between the two groups. Interestingly, LI10903F showed broad spectrum safety in a series of acute, sub-acute toxicity and genotoxicity studies. Conclusions: Results from the current research suggest that LI10903F or LOWAT is well-tolerated, safe and effective for weight management.
    Digitale ISSN: 1476-511X
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Publikationsdatum: 2012-12-28
    Beschreibung: Land use and land cover (LULC) information is an important component influencing watershed modeling with regards to hydrology and water quality in the river basin. In this study, the sensitivity of the Soil and Water Assessment Tool (SWAT) model to LULC datasets with three points in time and three levels of detail was assessed in a coastal subtropical watershed located in Southeast China. The results showed good agreement between observed and simulated values for both monthly and daily streamflow and monthly NH4+-N and TP loads. Three LULC datasets in 2002, 2007 and 2010 had relatively little influence on simulated monthly and daily streamflow, whereas they exhibited greater effects on simulated monthly NH4+-N and TP loads. When using the two LULC datasets in 2007 and 2010 compared with that in 2002, the relative differences in predicted monthly NH4+-N and TP loads were −11.0 to −7.8% and −4.8 to −9.0%, respectively. There were no significant differences in simulated monthly and daily streamflow when using the three LULC datasets with ten, five and three categories. When using LULC datasets from ten categories compared to five and three categories, the relative differences in predicted monthly NH4+-N and TP loads were −6.6 to −6.5% and −13.3 to −7.3%, respectively. Overall, the sensitivity of the SWAT model to LULC datasets with different points in time and levels of detail was lower in monthly and daily streamflow simulation than in monthly NH4+-N and TP loads prediction. This research provided helpful insights into the influence of LULC datasets on watershed modeling.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Publikationsdatum: 2012-12-29
    Beschreibung: Background: The -493G/T polymorphism in the microsomal triglyceride transfer protein (MTP) gene is associated with lower serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels and longevity in several populations, but the results are inconsistent in different racial/ethnic groups. The current study was to investigate the plausible association of MTP -493G/T polymorphism with serum lipid levels and longevity in Zhuang long-lived families residing in Bama area, a famous home of longevity in Guangxi, China. Methods: The MTP -493G/T was genotyped by PCR-restriction fragment length polymorphism in 391 Bama Zhuang long-lived families (BLF, n = 1467, age 56.60 +/- 29.43 years) and four control groups recruited from Bama and out-of-Bama area with or without a familial history of exceptional longevity: Bama non-long-lived families (BNLF, n = 586, age 44.81 +/- 26.83 years), Bama non-Zhuang long-lived families (BNZLF, n = 444, age 52.09 +/- 31.91 years), Pingguo long-lived families (PLF, n = 658, age 50.83 +/- 30.30 years), and Pingguo non-long-lived families (PNLF, n = 539, age 38.74 +/- 24.69 years). Correlation analyses between genotypes and serum lipid levels and longevity were then performed. Results: No particularly favorable lipoprotein and clinical phenotypes were seen in BLF as compared to general families in the same area. Instead, the levels of total cholesterol (TC), TG, LDL-C, and the prevalence of dyslipidemia were significantly higher in the three Bama families as compared to the two non-Bama families (P 〈 0.01 for all). There were no differences in the allelic and genotypic frequencies among the tested cohorts (P 〉 0.05 for all), but the TT genotype tended to enrich in the three long-lived cohorts from both areas. In addition, the individuals harboring TT genotype exhibited lower LDL-C and TC levels in the overall populations and Bama populations with a region- and sex-specific pattern. Multiple linear regression analyses unraveled that LDL-C levels were correlated with genotypes in Bama combined population, BNLF, and the total population (P 〈 0.05 for each) but not in Pingguo populations; TC and HDL-C levels were correlated with genotypes in Bama combined population and BLF, respectively (P 〈 0.05 for each). Conclusions: MTP -493G/T polymorphism may play an important role in fashioning the serum lipid profiles of Bama populations, despite no direct association between MTP -493G/T and longevity was detected.
    Digitale ISSN: 1476-511X
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Publikationsdatum: 2012-12-29
    Beschreibung: Background: RNA interference (RNAi) becomes an increasingly important and effective genetic tool to study the function of target genes by suppressing specific genes of interest. This system approach helps identify signaling pathways and cellular phase types by tracking intensity and/or morphological changes of cells. The traditional RNAi screening scheme, in which one siRNA is designed to knockdown one specific mRNA target, needs a large library of siRNAs and turns out to be time-consuming and expensive. Results: In this paper, we propose a conceptual model, called compressed sensing RNAi (csRNAi), which employs the unique combination of group of small interfering RNAs (siRNAs) to knockdown a much larger size of genes. This strategy is based on the fact that one gene can be partially bound with several small interfering RNAs (siRNAs) and conversely, one siRNA can bind to a few genes with distinct binding affinity. This model constructs a multi-to-multi correspondence between siRNAs and their targets, with siRNAs much fewer than mRNA targets, compared with the conventional scheme. Mathematically this problem involves an underdetermined system of equations (linear or nonlinear), which is ill-posed in general. However, the recently developed compressed sensing (CS) theory can solve this problem. We present a mathematical model to describe the csRNAi system based on both CS theory and biological concerns. To build this model, we first search nucleotide motifs in a target gene set. Then we propose a machine learning based method to find the effective siRNAs with novel features, such as image features and speech features to describe an siRNA sequence. Numerical simulations show that we can reduce the siRNA library to one third of that in the conventional scheme. In addition, the features to describe siRNAs outperform the existing ones substantially. Conclusions: This csRNAi system is very promising in saving both time and cost for large-scale RNAi screening experiments which may benefit the biological research with respect to cellular processes and pathways.
    Digitale ISSN: 1471-2105
    Thema: Biologie , Informatik
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Publikationsdatum: 2012-12-29
    Beschreibung: Background: Copy number variations (CNVs) are genomic structural variants that are found in healthy populations and have been observed to be associated with disease susceptibility. Existing methods for CNV detection are often performed on a sample-by-sample basis, which is not ideal for large datasets where common CNVs must be estimated by comparing the frequency of CNVs in the individual samples. Here we describe a simple and novel approach to locate genome-wide CNVs common to a specific population, using human ancestry as the phenotype. Results: We utilized our previously published Genome Alteration Detection Analysis (GADA) algorithm to identify common ancestry CNVs (caCNVs) and built a caCNV model to predict population structure. We identified a 73 caCNV signature using a training set of 225 healthy individuals from European, Asian, and African ancestry. The signature was validated on an independent test set of 300 individuals with similar ancestral background. The error rate in predicting ancestry in this test set was 2% using the 73 caCNV signature. Among the caCNVs identified, several were previously confirmed experimentally to vary by ancestry. Our signature also contains a caCNV region with a single microRNA (MIR270), which represents the first reported variation of microRNA by ancestry. Conclusions: We developed a new methodology to identify common CNVs and demonstrated its performance by building a caCNV signature to predict human ancestry with high accuracy. The utility of our approach could be extended to large case--control studies to identify CNV signatures for other phenotypes such as disease susceptibility and drug response.
    Digitale ISSN: 1471-2105
    Thema: Biologie , Informatik
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Publikationsdatum: 2012-12-29
    Beschreibung: Background: Understanding demographic histories, such as divergence time, patterns of gene flow, and population size changes, in ecologically diverging lineages provide implications for the process and maintenance of population differentiation by ecological adaptation. This study addressed the demographic histories in two independently derived lineages of flood-resistant riparian plants and their non-riparian relatives [Ainsliaea linearis (riparian) and A. apiculata (non-riparian); A. oblonga (riparian) and A. macroclinidioides (non-riparian); Asteraceae] using an isolation-with-migration (IM) model based on variation at 10 nuclear DNA loci. Results: The highest posterior probabilities of the divergence time parameters were estimated to be ca. 25,000 years ago for A. linearis and A. apiculata and ca. 9000 years ago for A. oblonga and A. macroclinidioides, although the confidence intervals of the parameters had broad ranges. The likelihood ratio tests detected evidence of historical gene flow between both riparian/non-riparian species pairs. The riparian populations showed lower levels of genetic diversity and a significant reduction in effective population sizes compared to the non-riparian populations and their ancestral populations. Conclusions: This study showed the recent origins of flood-resistant riparian plants, which are remarkable examples of plant ecological adaptation. The recent divergence and genetic signatures of historical gene flow among riparian/non-riparian species implied that they underwent morphological and ecological differentiation within short evolutionary timescales and have maintained their species boundaries in the face of gene flow. Comparative analyses of adaptive divergence in two sets of riparian/non-riparian lineages suggested that strong natural selection by flooding had frequently reduced the genetic diversity and size of riparian populations through genetic drift, possibly leading to fixation of adaptive traits in riparian populations. The two sets of riparian/non-riparian lineages showed contrasting patterns of gene flow and genetic differentiation, implying that each lineage showed different degrees of reproductive isolation and that they had experienced unique evolutionary and demographic histories in the process of adaptive divergence.
    Digitale ISSN: 1471-2148
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Publikationsdatum: 2012-12-30
    Beschreibung: Background: HIV/AIDS has several means of transmission. Exposure to blood and other body fluids is a very important means of transmission. Healthcare workers are exposed to this disease mainly due to the nature of their work. This is an exploration of the perceptions of healthcare workers of the University of Gondar Hospital. Methods: Based on purposive sampling seven healthcare workers were selected from different departments in the hospital so that they could reflect on their perceptions. The selected healthcare workers were asked about the risks related to their work, their experience of HIV related hazards and their general views on the transmission of HIV. The main themes were identified for analysis and the views were summarized under the themes. Results: All the respondents were aware of the risk of acquiring HIV in healthcare settings. Some had experienced accidents that made them take post-exposure prophylaxis, and most witnessed accidents like needle-stick injuries to their colleagues. They also expressed their feelings that their workplace was not the best place to work at. Conclusion: Health professionals are well aware of the possibility of HIV transmission associated with their practice. Accidents like needle stick injuries are apparently common; and at the same time, the practice of healthcare workers towards using universal precautions looks poor.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    Publikationsdatum: 2012-12-30
    Beschreibung: Background: Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. Results: We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods -- early embryogenesis, eye development, snout formation, and juvenile -- which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Conclusions: Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish.
    Digitale ISSN: 1471-213X
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    Publikationsdatum: 2012-12-30
    Beschreibung: Background: Maize is a major crop plant, grown for human and animal nutrition, as well as a renewable resource forbioenergy. When looking at the problems of limited fossil fuels, the growth of the world's population or theworld's climate change, it is important to find ways to increase the yield and biomass of maize and to studyhow it reacts to specific abiotic and biotic stress situations. Within the OPTIMAS systems biology projectmaize plants were grown under a large set of controlled stress conditions, phenotypically characterised andplant material was harvested to analyse the effect of specific environmental conditions or developmentalstages. Transcriptomic, metabolomic, ionomic and proteomic parameters were measured from the same plantmaterial allowing the comparison of results across different omics domains. A data warehouse wasDescriptionThe OPTIMAS Data Warehouse (OPTIMAS-DW) is a comprehensive data collection for maize and integratesdata from different data domains such as transcriptomics, metabolomics, ionomics, proteomics andphenomics. Within the OPTIMAS project, a 44K oligo chip was designed and annotated to describe thefunctions of the selected unigenes. Several treatment- and plant growth stage experiments were performed andmeasured data were filled into data templates and imported into the data warehouse by a Java based importtool. A web interface allows users to browse through all stored experiment data in OPTIMAS-DW includingall data domains. Furthermore, the user can filter the data to extract information of particular interest. All datacan be exported into different file formats for further data analysis and visualisation. The data analysisintegrates data from different data domains and enables the user to find answers to different systems biologyquestions. Finally, maize specific pathway information is provided. Conclusions: With OPTIMAS-DW a data warehouse for maize was established, which is able to handle different datadomains, comprises several analysis results that will support researchers within their work and supportssystems biological research in particular. The system is available athttp://www.optimas-bioenergy.org/optimas_dw.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    Publikationsdatum: 2012-12-30
    Beschreibung: Background: Health control beliefs were postulated to be associated with health behaviour. However, the results of studies assessing these associations suggest that they might not be universal. Among young adults associations have been reported, but, the evidence is limited. The objective of this analysis was to re-examine these associations in a sample of university students in Germany.FindingsData from a multicentre cross-sectional study among university students in North Rhine-Westphalia, Germany was used (N=3,306). The Multidimensional Health Locus of Control Scale with three dimensions (one internal and two external) and six aspects of health behaviour (smoking habits, alcohol use, drug consumption, being over-/ or underweight, physical activity, and importance of healthy nutrition) were evaluated. Students with stronger internal locus of control scores paid more attention to healthy nutrition and displayed a higher level of physical activity. Individuals with a stronger belief in health professionals were less likely to use drugs and paid more attention to healthy nutrition. Furthermore, higher scores in the second external locus of control dimension (beliefs in luck or chance) were associated with a higher likelihood of current smoking, lower physical activity and less attention to healthy nutrition. Conclusions: Students engaged more strongly in unhealthy behaviour if they believed that luck determines health. In contrast, believing in having control over one's own health was associated with more healthy behaviour. These findings support the need to consider health control beliefs while designing preventive strategies in this specific population.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Publikationsdatum: 2012-12-30
    Beschreibung: Available online 29 December 2012 Publication year: 2012 Source: FEBS Open Bio A water-soluble selenoxide (DHS ox ) having a five-membered ring structure enables rapid and selective conversion of cysteinyl SH groups in a polypeptide chain into SS bonds in a wide pH and temperature range. It was previously demonstrated that the second-order rate constants for the SS formation with DHS ox would be proportional to the number of the free SH groups present in the substrate if there is no steric congestion around the SH groups. In the present study, kinetics of the SS formation with DHS ox was extensively studied at pH 4–10 and 25°C by using reduced ribonuclease A, recombinant hirudin variant (CX-397), insulin A- and B-chains, and relaxin A-chain, which have two to eight cysteine residues, as polythiol substrates. The obtained rate constants showed stochastic SS formation behaviors under most conditions. However, the rate constants for CX-397 at pH 8.0 and 10.0 were not proportional to the number of the free SH groups, suggesting that the SS intermediate ensembles possess densely packed structures under weakly basic conditions. The high two-electron redox potential of DHS ox (375 mV at 25°C) compared to L-cystine supported the high ability of DHS ox for SS formation in a polypeptide chain. Interestingly, the rate constants of the SS formation jumped up at a pH around the p K a value of the cysteinyl SH groups. The SS formation velocity was slightly decreased by addition of a denaturant due probably to the interaction between the denaturant and the peptide. The stochastic behaviors as well as the absolute values of the second-order rate constants in comparison to dithiothreitol (DTT red ) are useful to probe the chemical reactivity and conformation, hence the folding, of polypeptide chains. Graphical abstract Highlights ▸ DHS ox was applied as a SS-forming reagent for five polythiol peptides and DTT red . ▸ The SS formation velocities depend on the kind of substrate and solvent conditions. ▸ The SS-formation rate constants are proportional to the number of free SH groups. ▸ Folded structures and SH p K a modify the stochastic nature and absolute values of the rate constants. ▸ DHS ox is a useful probe of chemical reactivity and intermediate structures in oxidative protein folding.
    Digitale ISSN: 2211-5463
    Thema: Biologie
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Publikationsdatum: 2012-12-19
    Beschreibung: Background: In higher eukaryotes, gene expression is regulated at different levels. In particular, 3[prime]UTRs play a central role in translation, stability and subcellular localization of transcripts. In recent years, the development of high throughput sequencing techniques has facilitated the acquisition of transcriptional data at a genome wide level. However, annotation of the 3[prime] ends of genes is still incomplete, thus limiting the interpretation of the data generated. For example, we have previously reported two different genes, ADD2 and CPEB3, with conserved 3[prime]UTR alternative isoforms not annotated in the current versions of Ensembl and RefSeq human databases. Results: In order to evaluate the existence of other conserved 3[prime] ends not annotated in these databases we have now used comparative genomics and transcriptomics across several vertebrate species. In general, we have observed that 3[prime]UTR conservation is lost after the end of the mature transcript. Using this change in conservation before and after the 3[prime] end of the mature transcripts we have shown that many conserved ends were still not annotated. In addition, we used orthologous transcripts to predict 3[prime]UTR extensions and validated these predictions using total RNA sequencing data. Finally, we used this method to identify not annotated 3[prime] ends in rats and dogs. As a result, we report several hundred novel 3[prime]UTR extensions in rats and a few thousand in dogs. Conclusions: The methods presented here can efficiently facilitate the identification of not-yet-annotated conserved 3[prime]UTR extensions. The application of these methods will increase the confidence of orthologous gene models across vertebrates.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Publikationsdatum: 2012-12-19
    Beschreibung: Background: For selection and evaluation of potential biomarkers, inclusion of already published information is of utmost importance. In spite of significant advancements in text- and data-mining techniques, the vast knowledge space of biomarkers in biomedical text has remained unexplored. Existing named entity recognition approaches are not sufficiently selective for the retrieval of biomarker information from the literature. The purpose of this study was to identify textual features that enhance the effectiveness of biomarker information retrieval for different indication areas and diverse end user perspectives. Methods: A biomarker terminology was created and further organized into six concept classes. Performance of this terminology was optimized towards balanced selectivity and specificity. The information retrieval performance using the biomarker terminology was evaluated based on various combinations of the terminology's six classes. Further validation of these results was performed on two independent corpora representing two different neurodegenerative diseases. Results: The current state of the biomarker terminology contains 119 entity classes supported by 1890 different synonyms. The result of information retrieval shows improved retrieval rate of informative abstracts, which is achieved by including clinical management terms and evidence of gene/protein alterations (e.g. gene/protein expression status or certain polymorphisms) in combination with disease and gene name recognition. When additional filtering through other classes (e.g. diagnostic or prognostic methods) is applied, the typical high number of unspecific search results is significantly reduced. The evaluation results suggest that this approach enables the automated identification of biomarker information in the literature. A demo version of the search engine SCAIView, including the biomarker retrieval, is made available to the public through http://www.scaiview.com/scaiview-academia.html. Conclusions: The approach presented in this paper demonstrates that using a dedicated biomarker terminology for automated analysis of the scientific literature maybe helpful as an aid to finding biomarker information in text. Successful extraction of candidate biomarkers information from published resources can be considered as the first step towards developing novel hypotheses. These hypotheses will be valuable for the early decision-making in the drug discovery and development process.
    Digitale ISSN: 1472-6947
    Thema: Informatik , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Publikationsdatum: 2012-12-19
    Beschreibung: Background: Pineapple (Ananas comosus) is a tropical fruit crop of significant commercial importance. Although the physiological changes that occur during pineapple fruit development have been well characterized, little is known about the molecular events that occur during the fruit ripening process. Understanding the molecular basis of pineapple fruit ripening will aid the development of new varieties via molecular breeding or genetic modification. In this study we developed a 9277 element pineapple microarray and used it to profile gene expression changes that occur during pineapple fruit ripening. Results: Microarray analyses identified 271 unique cDNAs differentially expressed at least 1.5-fold between the mature green and mature yellow stages of pineapple fruit ripening. Among these 271 sequences, 184 share significant homology with genes encoding proteins of known function, 53 share homology with genes encoding proteins of unknown function and 34 share no significant homology with any database accession. Of the 237 pineapple sequences with homologs, 160 were up-regulated and 77 were down-regulated during pineapple fruit ripening. DAVID Functional Annotation Cluster (FAC) analysis of all 237 sequences with homologs revealed confident enrichment scores for redox activity, organic acid metabolism, metalloenzyme activity, glycolysis, vitamin C biosynthesis, antioxidant activity and cysteine peptidase activity, indicating the functional significance and importance of these processes and pathways during pineapple fruit development. Quantitative real-time PCR analysis validated the microarray expression results for nine out of ten genes tested. Conclusions: This is the first report of a microarray based gene expression study undertaken in pineapple. Our bioinformatic analyses of the transcript profiles have identified a number of genes, processes and pathways with putative involvement in the pineapple fruit ripening process. This study extends our knowledge of the molecular basis of pineapple fruit ripening and non-climacteric fruit ripening in general.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    Publikationsdatum: 2012-12-19
    Beschreibung: Background: Accumulation of extracellular matrix (ECM) and increased matrix metalloproteinase (MMP) activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl4 treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M), known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model.FindingsIn vivo: Rats were treated for 8 weeks with CCl4/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control) or treated with IBMX (phosphodiesterase inhibitor). Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography.Ex vivo: The levels of serum C3M increased 77% in the CCl4-treated rats at week 8 (p 〈 0.01); Levels of C3M increased significantly by 100% in fibrotic liver slices compared to controls after 48 hrs (p 〈 0.01). By adding GM6001 or IBMX to the media, C3M was restored to control levels. Gelatin zymography demonstrated CCl4-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals. Conclusions: We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Cia5a is a locus on rat chromosome 10 that regulates disease severity and joint damage in two models of rheumatoid arthritis, collagen- and pristane-induced arthritis (PIA). In this study, we aimed to identify cellular and molecular processes regulated by Cia5a using microarray-based gene expression analysis of synovial tissues from MHC identical DA (severe erosive disease) and DA.F344(Cia5a) congenics (mild non-erosive disease) rats. Results: Synovial tissues from six DA and eight DA.F344(Cia5a) rats were analyzed 21 days after the induction of PIA using the Illumina RatRef-12 BeadChip (21,922 genes) and selected data confirmed with qPCR. There was a significantly increased expression of pro-inflammatory mediators such as Il1b (5-fold), Il18 (3.9-fold), Cxcl1 (10-fold), Cxcl13 (7.5-fold) and Ccl7 (7.9-fold), and proteases like Mmp3 (23-fold), Mmp9 (32-fold), Mmp14 (4.4-fold) and cathepsins in synovial tissues from DA, with reciprocally reduced levels in congenics. mRNA levels of 47 members of the Spleen Tyrosine Kinase (Syk) pathway were significantly increased in DA synovial tissues compared with DA.F344(Cia5a), and included Syk (5.4-fold), Syk-activating receptors and interacting proteins, and genes regulated by Syk such as NFkB, and NAPDH oxidase complex genes. Nuclear receptors (NR) such as Rxrg, Pparg and Rev-erba were increased in the protected congenics, and so was the anti-inflammatory NR-target gene Scd1 (54-fold increase). Tnn (72-fold decrease) was the gene most significantly increased in DA. Conclusions: Analyses of gene expression in synovial tissues revealed that the arthritis severity locus Cia5a regulates the expression of key mediators of inflammation and joint damage, as well as the expression of members of the Syk pathway. This expression pattern correlates with disease severity and joint damage and along with the gene accounting for Cia5a could become a useful biomarker to identify patients at increased risk for severe and erosive disease. The identification of the gene accounting for Cia5a has the potential to generate a new and important target for therapy and prognosis.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Traditional candidate gene approach has been widely used for the study of complex diseases including obesity. However, this approach is largely limited by its dependence on existing knowledge of presumed biology of the phenotype under investigation. Our combined strategy of comparative genomics and chromosomal heritability estimate analysis of obesity traits, subscapular skinfold thickness and back-fat thickness in Korean cohorts and pig (Sus scrofa), may overcome the limitations of candidate gene analysis and allow us to better understand genetic predisposition to human obesity. Results: We found common genes including FTO, the fat mass and obesity associated gene, identified from significant SNPs by association studies of each trait. These common genes were related to blood pressure and arterial stiffness (P = 1.65E-05) and type 2 diabetes (P = 0.00578). Through the estimation of variance of genetic component (heritability) for each chromosome by SNPs, we observed a significant positive correlation (r = 0.479) between genetic contributions of human and pig to obesity traits. Furthermore, we noted that the phenotypic variance for obesity can be explained dominantly by chromosome 2, which is syntenic to pig chromosomes 3 and 15. Conclusions: Obesity genetics still awaits further discovery. Navigating syntenic regions suggests obesity candidate genes on chromosome 2 that are previously known to be associated with obesity-related diseases: MRPL33, PARD3B, ERBB4, STK39, and ZNF385B.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Phenotypic evolution in animals is thought to be driven in large part by differences in gene expression patterns, which can result from sequence changes in cis-regulatory elements (cis-changes) or from changes in the expression pattern or function of transcription factors (trans-changes). While isolated examples of trans-changes have been identified, the scale of their overall contribution to regulatory and phenotypic evolution remains unclear. Results: Here, we attempt to examine the prevalence of trans-effects and their potential impact on gene expression patterns in vertebrate evolution by comparing the function of identical human tissue-specific enhancer sequences in two highly divergent vertebrate model systems, mouse and zebrafish. Among 47 human conserved non-coding elements (CNEs) tested in transgenic mouse embryos and in stable zebrafish lines, at least one species-specific expression domain was observed in the majority (83%) of cases, and 36% presented dramatically different expression patterns between the two species. Although some of these discrepancies may be due to the use of different transgenesis systems in mouse and zebrafish, in some instances we found an association between differences in enhancer activity and changes in the endogenous gene expression patterns between mouse and zebrafish, suggesting a potential role for trans-changes in the evolution of gene expression. Conclusions: In total, our results: (i) serve as a cautionary tale for studies investigating the role of human enhancers in different model organisms, and (ii) suggest that changes in the trans environment may play a significant role in the evolution of gene expression in vertebrates.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Tourette Syndrome (TS) is a neuropsychiatric disorder in children characterized by motor andverbal tics. Although several genes have been suggested in the etiology of TS, the geneticmechanisms remain poorly understood. Methods: Using cytogenetics and FISH analysis, we identified an apparently balancedt(6,22)(q16.2;p13) in a male patient with TS and obsessive-compulsive disorder (OCD). Inorder to map the breakpoints and to identify additional submicroscopic rearrangements, weperformed whole genome mate-pair sequencing and CGH-array analysis on DNA from theproband. Results: Sequence and CGH array analysis revealed a 400 kb deletion located 1.3 Mb telomeric of thechromosome 6q breakpoint, which has not been reported in controls. The deletion affectsthree genes (GPR63, NDUFA4 and KLHL32) and overlaps a region previously found deletedin a girl with autistic features and speech delay. The proband's mother, also a carrier of thetranslocation, was diagnosed with OCD and shares the deletion. We also describe a furtherpotentially related rearrangement which, while unmapped in Homo sapiens, was consistentwith the chimpanzee genome. Conclusions: We conclude that genome-wide sequencing at relatively low resolution can be used for theidentification of submicroscopic rearrangements.We also show that large rearrangements may escape detection using standard analysis ofwhole genome sequencing data. Our findings further provide a candidate region for TS andOCD on chromosome 6q16.
    Digitale ISSN: 1471-2350
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Secretoglobin 1A1 (SCGB 1A1), also called Clara cell secretory protein, is the most abundantly secreted protein of the airway. The SCGB1A1 gene has been characterized in mammals as a single copy in the genome. However, analysis of the equine genome suggested that horses might have multiple SCGB1A1 gene copies. Non-ciliated lung epithelial cells produce SCGB 1A1 during inhalation of noxious substances to counter airway inflammation. Airway fluid and lung tissue of horses with recurrent airway obstruction (RAO), a chronic inflammatory lung disease affecting mature horses similar to environmentally induced asthma of humans, have reduced total SCGB 1A1 concentration. Herein, we investigated whether horses have distinct expressed SCGB1A1 genes; whether the transcripts are differentially expressed in tissues and in inflammatory lung disease; and whether there is cell specific protein expression in tissues. Results: We identified three SCGB1A1 gene copies on equine chromosome 12, contained within a 512-kilobase region. Bioinformatic analysis showed that SCGB1A1 genes differ from each other by 8 to 10 nucleotides, and that they code for different proteins. Transcripts were detected for SCGB1A1 and SCGB1A1A, but not for SCGB1A1P. The SCGB1A1P gene had most inter-individual variability and contained a non-sense mutation in many animals, suggesting that SCGB1A1P has evolved into a pseudogene. Analysis of SCGB1A1 and SCGB1A1A sequences by endpoint-limiting dilution PCR identified a consistent difference affecting 3 bp within exon 2, which served as a gene-specific "signature". Assessment of gene- and organ-specific expression by semiquantitative RT-PCR of 33 tissues showed strong expression of SCGB1A1 and SCGB1A1A in lung, uterus, Fallopian tube and mammary gland, which correlated with detection of SCGB 1A1 protein by immunohistochemistry. Significantly altered expression of the ratio of SCGB1A1A to SCGB1A1 was detected in RAO-affected animals compared to controls, suggesting different roles for SCGB 1A1 and SCGB 1A1A in this inflammatory condition. Conclusions: This is the first report of three SCGB1A1 genes in a mammal. The two expressed genes code for proteins predicted to differ in function. Alterations in the gene expression ratio in RAO suggest cell and tissue specific regulation and functions. These findings may be important for understanding of lung and reproductive conditions.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: To determine the general appearance of normal axillary lymph nodes (LNs) in real-time tissue sonoelastography and to explore the method[prime]s potential value in the prediction of LN metastases. Methods: Axillary LNs in healthy probands (n=165) and metastatic LNs in breast cancer patients (n=15) were examined with palpation, B-mode ultrasound, Doppler and sonoelastography (assessment of the elasticity of the cortex and the medulla). The elasticity distributions were compared and sensitivity (SE) and specificity (SP) were calculated. In an exploratory analysis, positive and negative predictive values (PPV, NPV) were calculated based upon the estimated prevalence of LN metastases in different risk groups. Results: In the elastogram, the LN cortex was significantly harder than the medulla in both healthy (p=0.004) and metastatic LNs (p=0.005). Comparing healthy and metastatic LNs, there was no difference in the elasticity distribution of the medulla (p=0.281), but we found a significantly harder cortex in metastatic LNs (p=0.006). The SE of clinical examination, B-mode ultrasound, Doppler ultrasound and sonoelastography was revealed to be 13.3%, 40.0%, 14.3% and 60.0%, respectively, and SP was 88.4%, 96.8%, 95.6% and 79.6%, respectively. The highest SE was achieved by the disjunctive combination of B-mode and elastographic features (cortex 〉3mm in B-mode or blue cortex in the elastogram, SE=73.3%). The highest SP was achieved by the conjunctive combination of B-mode ultrasound and elastography (cortex 〉3mm in B-mode and blue cortex in the elastogram, SP=99.3%). Conclusions: Sonoelastography is a feasible method to visualize the elasticity distribution of LNs. Moreover, sonoelastography is capable of detecting elasticity differences between the cortex and medulla, and between metastatic and healthy LNs. Therefore, sonoelastography yields additional information about axillary LN status and can improve the PPV, although this method is still experimental.
    Digitale ISSN: 1471-2342
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: The use of food-grade Lactic Acid Bacteria (LAB) as DNA delivery vehicles represents an attractive strategy to deliver DNA vaccines at the mucosal surfaces as they are generally regarded as safe (GRAS). We previously showed that either native Lactococcus lactis (LL) or recombinant invasive LL expressing Fibronectin Binding Protein A of Staphylococcus aureus (LL-FnBPA+) or Internalin A of Listeria monocytogenes (LL-InlA+), were able to deliver and trigger DNA expression by epithelial cells, either in vitro or in vivo. InlA does not bind to its receptor, the murine E-cadherin, thus limiting the use of LL-InlA+in in vivo murine models. Moreover, FnBPA binds to its receptors, integrins, via fibronectin introducing another limiting factor. In order to avoid the limitations of LL-InlA+and LL-FnBPA+, a new L. lactis strain was engineered to produce a previously described mutated form of InlA (LL-mInlA+) allowing the binding of mInlA on murine E-cadherin. Results: After showing the expression of mInLA at the surface of LL-mInlA+strain, in vitro gentamycin survival assay in Caco-2 cells showed that LL-mInlA+is 1000 times more invasive than LL. LL-mInlA+invasivity was also validated by fluorescence microscopy. LL and LL-mInlA+were transformed with pValacBLG, a plasmid containing the cDNA of bovine beta-Lactoglobulin (BLG), resulting in strains LL-BLG and LL-mInlA+BLG. The plasmid transfer in vitro using LL-mInlA+BLG was increased 10 times compared to LL-BLG. Moreover, the number of mice producing BLG in isolated enterocytes after oral administration of LL-mInlA+BLG in vivo was slightly higher than after oral administration of LL-BLG. Conclusions: We confirmed in this study that the production of mInlA at the surface of L. lactis is a promising strategy for plasmid transfer in vitro and in vivo.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: The 22q11.2 deletion syndrome (22q11.2DS) is caused by hemizygous microdeletions on chromosome 22q11.2 with highly variable physical and neuropsychiatric manifestations. We explored the genotype-phenotype relationship in a relatively large 22q11.2DS cohort treated and monitored in our clinic using comprehensive clinical evaluation and detailed molecular characterization of the deletion. Methods: Molecular analyses in 142 subjects with 22q11.2DS features were performed by FISH and MLPA methods. Participants underwent clinical assessment of physical symptoms and structured psychiatric and cognitive evaluation. Results: Deletions were found in 110 individuals including one with an atypical nested distal deletion which was missed by the FISH test. Most subjects (88.2%) carried the 3Mb typically deleted region and 11.8% carried 4 types of deletions differing in size and location. No statistically significant genotype-phenotype correlations were found between deletion type and clinical data although some differences in hypocalcemia and cardiovascular anomalies were noted.Analysis of the patient with the distal nested deletion suggested a redundancy of genes causing the physical and neuropsychiatric phenotype in 22q11.2DS and indicating that the psychiatric and cognitive trajectories may be governed by different genes. Conclusions: MLPA is a useful and affordable molecular method combining accurate diagnosis and detailed deletion characterization. Variations in deletion type and clinical manifestations impede the detection of significant differences in samples of moderate size, but analysis of individuals with unique deletions may provide insight into the underlying biological mechanisms.Future genotype-phenotype studies should involve large multicenter collaborations employing uniform clinical standards and high-resolution molecular methods.
    Digitale ISSN: 1471-2350
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: In eukaryotic cells, dynamin and flotillin are involved in processes such as endocytosis and lipid raft formation, respectively. Dynamin is a GTPase that exerts motor-like activity during the pinching off of vesicles, while flotillins are coiled coil rich membrane proteins with no known enzymatic activity. Bacteria also possess orthologs of both classes of proteins, but their function has been unclear. Results: We show that deletion of the single dynA or floT genes lead to no phenotype or a mild defect in septum formation in the case of the dynA gene, while dynA floT double mutant cells were highly elongated and irregularly shaped, although the MreB cytoskeleton appeared to be normal. DynA colocalizes with FtsZ, and the dynA deletion strain shows aberrant FtsZ rings in a subpopulation of cells. The mild division defect of the dynA deletion is exacerbated by an additional deletion in ezrA, which affects FtsZ ring formation, and also by the deletion of a late division gene (divIB), indicating that DynA affects several steps in cell division. DynA and mreB deletions generated a synthetic defect in cell shape maintenance, showing that MreB and DynA play non-epistatic functions in cell shape maintenance. TIRF microscopy revealed that FloT forms many dynamic membrane assemblies that frequently colocalize with the division septum. The deletion of dynA did not change the pattern of localization of FloT, and vice versa, showing that the two proteins play non redundant roles in a variety of cellular processes. Expression of dynamin or flotillin T in eukaryotic S2 cells revealed that both proteins assemble at the cell membrane. While FloT formed patch structures, DynA built up tubulated structures extending away from the cells. Conclusions: Bacillus subtilis dynamin ortholog DynA plays a role during cell division and in cell shape maintenance. It shows a genetic link with flotillin T, with both proteins playing non-redundant functions at the cell membrane, where they assemble even in the absence of any bacterial cofactor.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: To derive post-genomic, neutral insight into the peptidoglycan (PG) distribution among organisms, we mined 1,644 genomes listed in the Carbohydrate-Active Enzymes database for the presence of a minimal 3-gene set that is necessary for PG metabolism. This gene set consists of one gene from the glycosyltransferase family GT28, one from family GT51 and at least one gene belonging to one of five glycoside hydrolase families (GH23, GH73, GH102, GH103 and GH104). Results: None of the 103 Viruses or 101 Archaea examined possessed the minimal 3-gene set, but this set was detected in 1/42 of the Eukarya members (Micromonas sp., coding for GT28, GT51 and GH103) and in 1,260/1,398 (90.1%) of Bacteria, with a 100% positive predictive value for the presence of PG. Pearson correlation test showed that GT51 family genes were significantly associated with PG with a value of 0.963 and a p value less than 10-3. This result was confirmed by a phylogenetic comparative analysis showing that the GT51-encoding gene was significantly associated with PG with a Pagel's score of 60 and 51 (percentage of error close to 0%). Phylogenetic analysis indicated that the GT51 gene history comprised eight loss and one gain events, and suggested a dynamic on-going process. Conclusions: Genome analysis is a neutral approach to explore prospectively the presence of PG in uncultured, sequenced organisms with high predictive values.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Toxin complex (Tc) family proteins were first identified as insecticidal toxins in Photorhabdus luminescens and have since been found in a wide range of bacteria. The genome of Yersinia pestis, the causative agent of bubonic plague, contains a locus that encodes the Tc protein homologues YitA, YitB, YitC, and YipA and YipB. Previous microarray data indicate that the Tc genes are highly upregulated by Y. pestis while in the flea vector; however, their role in the infection of fleas and pathogenesis in the mammalian host is unclear. Results: We show that the Tc proteins YitA and YipA are highly produced by Y. pestis while in the flea but not during growth in brain heart infusion (BHI) broth at the same temperature. Over-production of the LysR-type regulator YitR from an exogenous plasmid increased YitA and YipA synthesis in broth culture. The increase in production of YitA and YipA correlated with the yitR copy number and was temperature-dependent. Although highly synthesized in fleas, deletion of the Tc proteins did not alter survival of Y. pestis in the flea or prevent blockage of the proventriculus. Furthermore, YipA was found to undergo post-translational processing and YipA and YitA are localized to the outer membrane of Y. pestis. YitA was also detected by immunofluorescence microscopy on the surface of Y. pestis. Both YitA and YipA are produced maximally at low temperature but persist for several hours after transfer to 37[degree sign]C. Conclusions: Y. pestis Tc proteins are highly expressed in the flea but are not essential for Y. pestis to stably infect or produce a transmissible infection in the flea. However, YitA and YipA localize to the outer membrane and YitA is exposed on the surface, indicating that at least YitA is present on the surface when Y. pestis is transmitted into the mammalian host from the flea.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Fermentative bacteria offer the potential to convert lignocellulosic waste-streams into biofuels such as hydrogen (H2) and ethanol. Current fermentative H2 and ethanol yields, however, are below theoretical maxima, vary greatly among organisms, and depend on the extent of metabolic pathways utilized. For fermentative H2 and/or ethanol production to become practical, biofuel yields must be increased. We performed a comparative meta-analysis of (i) reported end-product yields, and (ii) genes encoding pyruvate metabolism and end-product synthesis pathways to identify suitable biomarkers for screening a microorganism's potential of H2 and/or ethanol production, and to identify targets for metabolic engineering to improve biofuel yields. Our interest in H2 and/or ethanol optimization restricted our meta-analysis to organisms with sequenced genomes and limited branched end-product pathways. These included members of the Firmicutes, Euryarchaeota, and Thermotogae. Results: Bioinformatic analysis revealed that the absence of genes encoding acetaldehyde dehydrogenase and bifunctional acetaldehyde/alcohol dehydrogenase (AdhE) in Caldicellulosiruptor, Thermococcus, Pyrococcus, and Thermotoga species coincide with high H2 yields and low ethanol production. Organisms containing genes (or activities) for both ethanol and H2 synthesis pathways (i.e. Caldanaerobacter subterraneus subsp. tengcongensis, Ethanoligenens harbinense, and Clostridium species) had relatively uniform mixed product patterns. The absence of hydrogenases in Geobacillus and Bacillus species did not confer high ethanol production, but rather high lactate production. Only Thermoanaerobacter pseudethanolicus produced relatively high ethanol and low H2 yields. This may be attributed to presence of genes encoding proteins that promote NADH production. Lactate dehydrogenase and pyruvate:formate lyase are not conducive for ethanol and/or H2 production. While the type(s) of encoded hydrogenases appear to have little impact on H2 production in organisms that do not encode ethanol producing pathways, they do influence reduced end-product yields in those that do. Conclusions: Here we show that composition of genes encoding pathways involved in pyruvate catabolism and end-product synthesis pathways can be used to approximate potential end-product distribution patterns. We have identified a number of genetic biomarkers for streamlining ethanol and H2 producing capabilities. By linking genome content, reaction thermodynamics, and end-product yields, we offer potential targets for optimization of either ethanol or H2 yields through metabolic engineering.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
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  • 55
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: Endolysins produced by bacteriophages lyse bacteria, and are thus considered a novel type of antimicrobial agent. Several endolysins from Bacillus phages or prophages have previously been characterized and used to target Bacillus strains that cause disease in animals and humans. B. thuringiensis phage BtCS33 is a Siphoviridae family phage and its genome has been sequenced and analyzed. In the BtCS33 genome, orf18 was found to encode an endolysin protein (PlyBt33). Results: Bioinformatic analyses showed that endolysin PlyBt33 was composed of two functional domains, the N-terminal catalytic domain and the C-terminal cell wall binding domain. In this study, the entire endolysin PlyBt33, and both the N- and C-termini,were expressed in Escherichia coli and then purified. The lytic activities of PlyBt33 and its N-terminus were tested on bacteria. Both regions exhibited lytic activity, although PlyBt33 showed a higher lytic activity than the N-terminus. PlyBt33 exhibited activity against all Bacillus strains tested from five different species, but was not active against Gram-negative bacteria. Optimal conditions for PlyBt33 reactivity were pH 9.0 and 50[degree sign]C. PlyBt33 showed high thermostability, with 40% of initial activity remaining following 1 h of treatment at 60[degree sign]C. The C-terminus of PlyBt33 bound to B. thuringiensis strain HD-73 and Bacillus subtilis strain 168. This cell wall binding domain might be novel, as its amino acid sequence showed little similarity to previously reported endolysins. Conclusions: PlyBt33 showed potential as a novel antimicrobial agent at a relatively high temperature and had a broad lytic spectrum within the Bacillus genus. The C-terminus of PlyBt33 might be a novel kind of cell wall binding domain.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: In plants, the multistep phosphorelay signaling pathway mediates responses to environmental factors and plant hormones. This system is composed of three successive partners: hybrid Histidine-aspartate Kinases (HKs), Histidine-containing Phosphotransfer proteins (HPts), and Response Regulators (RRs). Among the third partners, B-type RR family members are the final output elements of the pathway; they act as transcription factors and clearly play a pivotal role in the early response to cytokinin in Arabidopsis. While interactions studies between partners belonging to the multistep phosphorelay system are mainly focused on protagonists involved in cytokinin or ethylene pathways, very few reports are available concerning partners of osmotic stress signaling pathway. Results: In Populus, we identified eight B-type RR proteins, RR12-16, 19, 21 and 22 in the Dorskamp genotype. To assess HPt/B-type RR interactions and consequently determine potential third partners in the osmosensing multistep phosphorelay system, we performed global yeast two-hybrid (Y2H) assays in combination with Bimolecular Fluorescence Complementation (BiFC) assays in plant cells. We found that all B-type RRs are able to interact with HPt predominant partners (HPt2, 7 and 9) of HK1, which is putatively involved in the osmosensing pathway. However, different profiles of interaction are observed depending on the studied HPt. HPt/RR interactions displayed a nuclear localization, while the nuclear and cytosolic localization of HPt and nuclear localization of RR proteins were validated. Although the nuclear localization of HPt/RR interaction was expected, this work constitutes the first evidence of such an interaction in plants. Furthermore, the pertinence of this partnership is reinforced by highlighting a co-expression of B-type RR transcripts and the other partners (HK1 and HPts) belonging to a potential osmosensing pathway. Conclusion: Based on the interaction studies between identified B-type RR and HPt proteins, and the co-expression analysis of transcripts of these potential partners in poplar organs, our results favor the model that RR12, 13, 14, 16 and 19 are able to interact with the main partners of HK1, HPt2, 7 and 9, and this HPt/RR interaction occurs within the nucleus. On the whole, the five B-type RRs of interest could be third protagonists putatively involved in the osmosensing signaling pathway in Populus.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Publikationsdatum: 2012-12-20
    Beschreibung: Background: A measles outbreak was detected at Ndanga Hospital in Zaka district Masvingo Province on the 5th of May 2010 and there were five deaths. Source of infection was not known and an investigation was carried out to determine factors associated with contracting measles in Zaka district.Materials and methodsA 1:1 unmatched case control study was conducted. A case was a person residing in Zaka district who developed signs and symptoms of measles or tested IgM positive from 06 May 2010 to 30 August 2010. A control was a person residing in the same community who did not have history of signs and symptoms of measles during the same period. A structured interviewer administered questionnaire (translated into shona) was used to solicit information from cases and controls. Ethical consideration like written consent from all participants, respect and confidentiality were observed. Permission to carry out the study was obtained from the medical research Council of Zimbabwe and the provincial Medical Directors Masvingo. Epi info was used to calculate frequencies, odds ratios and perform logistic regression to control for confounding variables.FindingsA total of 110 cases and 110 controls were recruited. Most cases (63.03%) were from the apostolic sect while 44.7% of controls were from orthodox churches. Contact with a measles case [AOR= 41.14, 95% CI (7.47-226.5)],being unvaccinated against measles [AOR= 3.96, 95%CI (2.58-6.08)] and not receiving additional doses of measles vaccine [AOR 5.48, 95% CI (2.16-11.08)] were independent risk factor for contracting measles . Measles vaccination coverage for Zaka district was 75%. The median duration for seeking treatment after onset of illness was three days (Q1=2; Q3=7). There were no emergency preparedness plans in place. Conclusion: This outbreak occurred due to a large number of unvaccinated children and a boarding school that facilitated person to person transmission. We recommend mandatory vaccination for all children before enrolling into schools. As a result of the study one day training on outbreak management and surveillance was done with all District Nursing Officers and Environmental Health Officers in personnel in the province.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Publikationsdatum: 2012-12-20
    Beschreibung: Available online 19 December 2012 Publication year: 2012 Source: FEBS Open Bio The green fluorescent protein (GFP) is the most commonly used reporter protein for monitoring gene expression and protein localization in a variety of living and fixed cells, including not only prokaryotes, but also eukaryotes, e.g., yeasts, mammals, plants and fish. In general, it is thought that GFP is nontoxic to cells, although there are some reports on the side effect of GFP. However, details of the molecular mechanism concerning the side effect of GFP remain unclear. Here we show that Ku80, but not XRCC4, plays an important role in the mechanism of the resistance to cytotoxicity induced by enhanced GFP (EGFP). EGFP inhibited both cell proliferation and colony formation, and induced cell death in Ku80-deficient hamster cells, i.e., xrs-6 cells. In addition, Ku80 attenuated EGFP-induced cytotoxicity in the xrs-6 cells. No EGFP-induced cytotoxicity was observed in the NHEJ core protein XRCC4-deficient hamster cells, i.e., XR-1 cells. Furthermore, EGFP markedly enhanced X-ray-induced cytotoxicity in the xrs-6 cells. These results suggest that Ku80 plays a key role in the novel NHEJ-independent defense mechanism against EGFP-induced cytotoxicity. Caution should be taken in considering of the potential influence by the stress response mechanism, namely, the Ku80-dependent elimination mechanism of EGFP-induced cytotoxicity, being activated, even when using EGFP-expressing cells in which Ku80 functions normally.
    Digitale ISSN: 2211-5463
    Thema: Biologie
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Publikationsdatum: 2012-12-21
    Beschreibung: Background: The localized scleroderma (LS) known as morphea, presents a variety of clinical manifestations that can include systemic involvement. Current classification schemes divide morphea into categories based solely on cutaneous morphology, without reference to systemic disease or autoimmune phenomena. This classification is likely incomplete. Autoimmune phenomena such as vitiligo and Hashimoto thyroiditis associated with LS have been reported in some cases suggesting an autoimmune basis. To our knowledge this is the first case of a morphea forming part of a multiple autoimmune syndrome (MAS) and presenting simultaneously with autoimmune thrombocytopenic purpura and central nervous system vasculitis.Case presentationWe report an uncommon case of a white 53 year old female patient with LS as part of a multiple autoimmune syndrome associated with pneumonitis, autoimmune thrombocytopenic purpura and central nervous system vasculitis presenting a favorable response with thrombopoietin receptor agonists, pulses of methylprednisolone and cyclophosphamide. Conclusion: Is likely that LS have an autoimmune origin and in this case becomes part of MAS, which consist on the presence of three or more well-defined autoimmune diseases in a single patient.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Publikationsdatum: 2012-12-21
    Beschreibung: Background: Extensive research effort has advanced our understanding of Caenorhabditis as a model system, but its natural association with bacteria remains to be explored in an ecological context. Explored associations vary vastly from mutualistic to parasitic. Serratia marcescens has been shown to be pathogenic to Caenorhabditis with a fitness cost. The recent isolation of an entomopathogenic Caenorhabditis briggsae KT0001/S. marcescens SCBI association from the wild has allowed us to examine under laboratory conditions whether such an association poses a serious cost to Caenorhabditis as previously surmised for other Serratia. Results: A fecundity table of Caenorhabditis briggsae KT0001 fed on S. marcescens SCBI and the control fed on E. coli OP50 is presented. We found no significant difference in survivorship or total fecundity between the S. marcescens SCBI fed and E. coli OP50 fed Caenorhabditis briggsae KT0001. Only the mean onset of reproduction was significantly different between the two groups with E. coli fed C. briggsae maturing earlier (2.12 days) than those fed on Serratia (2.42 days). Conclusion: S. marcescens SCBI is not highly pathogenic to C. briggsae KT0001 indicating that the entomopathogenicity reported for this association may be beneficial for both the nematode and bacteria. In light of the fact that hitherto conducted experimental tests conform to widely held view that Serratia are highly pathogenic to Caenorhabditis, the absence of a high fitness cost for C. briggsae we report here may indicate that this entomopathogenic association is non-transient suggesting nematode/bacterial associations in the wild may vary greatly. Consequently, broad generalizations about nematode/bacterial associations should be interpreted with care.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Publikationsdatum: 2012-12-21
    Beschreibung: Available online 20 December 2012 Publication year: 2012 Source: Cell Reports In the fission yeast Schizosaccharomyces pombe , a chromosomal imprinting event controls the asymmetric pattern of mating-type switching. The orientation of DNA replication at the mating-type locus is instrumental in this process. However, the factors leading to imprinting are not fully identified and the mechanism is poorly understood. Here, we show that the replication fork pause at the mat1 locus ( MPS1 ), essential for imprint formation, depends on the lysine-specific demethylase Lsd1. We demonstrate that either Lsd1 or Lsd2 amine oxidase activity is required for these processes, working upstream of the imprinting factors Swi1 and Swi3 (homologs of mammalian Timeless and Tipin, respectively). We also show that the Lsd1/2 complex controls the replication fork terminators, within the rDNA repeats. These findings reveal a role for the Lsd1/2 demethylases in controlling polar replication fork progression, imprint formation, and subsequent asymmetric cell divisions. Graphical abstract Highlights ► The lysine-specific demethylase, Lsd1, is a mating-type switching mutant ► Lsd1 is essential for replication fork pausing at the mat1 locus ► Lsd1 is essential for replication fork arrest at the replication fork block at rDNA loci ► Lsd1 and Lsd2 act in a redundant manner for replication fork pausing
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    Publikationsdatum: 2012-12-22
    Beschreibung: Available online 21 December 2012 Publication year: 2012 Source: Cell Reports Chromatin dynamics play a central role in maintaining genome integrity, but how this is achieved remains largely unknown. Here, we report that microrchidia CW-type zinc finger 2 (MORC2), an uncharacterized protein with a derived PHD finger domain and a conserved GHKL-type ATPase module, is a physiological substrate of p21-activated kinase 1 (PAK1), an important integrator of extracellular signals and nuclear processes. Following DNA damage, MORC2 is phosphorylated on serine 739 in a PAK1-dependent manner, and phosphorylated MORC2 regulates its DNA-dependent ATPase activity to facilitate chromatin remodeling. Moreover, MORC2 associates with chromatin and promotes gamma-H2AX induction in a PAK1 phosphorylation-dependent manner. Consequently, cells expressing MORC2-S739A mutation displayed a reduction in DNA repair efficiency and were hypersensitive to DNA-damaging agent. These findings suggest that the PAK1-MORC2 axis is critical for orchestrating the interplay between chromatin dynamics and the maintenance of genomic integrity through sequentially integrating multiple essential enzymatic processes. Graphical abstract Highlights ► MORC2 is a DNA damage-responsive phosphoprotein activated by PAK1 kinase ► MORC2 regulates phosphorylation-coupled, ATPase-dependent chromatin remodeling ► MORC2 facilitates gamma-H2AX induction independently of PIKK kinases ► MORC2 promotes DSB repair in a PAK1 phosphorylation-dependent manner
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Publikationsdatum: 2012-12-21
    Beschreibung: Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    Publikationsdatum: 2012-12-21
    Beschreibung: Nanomaterials are structures whose exceptionality is based on their large surface, which is closely connected with reactivity and modification possibilities. Due to these properties nanomaterials are used in textile industry (antibacterial textiles with silver nanoparticles), electronics (high-resolution imaging, logical circuits on the molecular level) and medicine. Medicine represents one of the most important fields of application of nanomaterials. They are investigated in connection with targeted therapy (infectious diseases, malignant diseases) or imaging (contrast agents). Nanomaterials including nanoparticles have a great application potential in the targeted transport of pharmaceuticals. However, there are some negative properties of nanoparticles, which must be carefully solved, as hydrophobic properties leading to instability in aqueous environment, and especially their possible toxicity. Data about toxicity of nanomaterials are still scarce. Due to this fact, in this work we focused on studying of the effect of magnetic nanoparticles (NPs) and modified magnetic nanoparticles (MNPs) on tobacco BY-2 plant cell suspension culture. We aimed at examining the effect of NPs and MNPs on growth, proteosynthesis—total protein content, thiols—reduced (GSH) and oxidized (GSSG) glutathione, phytochelatins PC2-5, glutathione S-transferase (GST) activity and antioxidant activity of BY-2 cells. Whereas the effect of NPs and MNPs on growth of cell suspension culture was only moderate, significant changes were detected in all other biochemical parameters. Significant changes in protein content, phytochelatins levels and GST activity were observed in BY-2 cells treated with MNPs nanoparticles treatment. Changes were also clearly evident in the case of application of NPs. Our results demonstrate the ability of MNPs to negatively affect metabolism and induce biosynthesis of protective compounds in a plant cell model represented by BY-2 cell suspension culture. The obtained results are discussed, especially in connection with already published data. Possible mechanisms of NPs’ and MNPs’ toxicity are introduced.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    Publikationsdatum: 2012-11-09
    Beschreibung: First paragraph (this article has no abstract)What is regeneration? {1st level heading}Historically, philosophers, naturalists and biologists alike have referred to the restoration of missing body parts after traumatic injury as regeneration. While still valid today, the concept of regeneration has expanded through the years to include a diverse set of phenomena. For instance, August Weisman considered physiological cell renewal to be regeneration and wrote so in a chapter dedicated to regeneration in his seminal 1893 book The Germ Plasm: 'the functions of certain organs depend on the fact that their parts continually undergo destruction, and are then correspondingly renewed. In this case it is the process of life itself, and not an external enemy, that destroys the life of a cell' [1].
    Digitale ISSN: 1741-7007
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Publikationsdatum: 2012-11-09
    Beschreibung: Background The robust identification of isotope patterns originating from peptides being analyzed through mass spectrometry (MS) is often significantly hampered by noise artifacts and the interference of overlappingpatterns arising e.g. from post-translational modifications. As the classification of the recorded data points into either 'noise' or 'signal' lies at the very root of essentially every proteomic application, the quality of the automated processing of mass spectra can significantly influence the way the data might be interpreted within a given biological context.Results We propose non-negative least squares/non-negative least absolute deviation regression to fit a raw spectrum by templates imitating isotope patterns. In a carefully designed validation scheme, we show that the method exhibits excellent performance in pattern picking. It is demonstrated that the method is able to disentangle complicated overlaps of patterns. Conclusions: We find that regularization is not necessary to prevent overfitting and that thresholding is an effective and user-friendly way to perform feature selection. The proposed method avoids problems inherent in regularization-based approaches, comes with a set of well-interpretable parameters whose default configuration is shown to generalize well without the need for fine-tuning, and is applicable to spectra of different platforms. The R package IPPD implements the method and is available from the Bioconductor platform (http://bioconductor.fhcrc.org/help/bioc-views/devel/bioc/html/IPPD.html).
    Digitale ISSN: 1471-2105
    Thema: Biologie , Informatik
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 67
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Monosporascus cannonballus is the main causal agent of melon vine decline disease. Several studies have been carried out mainly focused on the study of the penetration of this pathogen into melon roots, the evaluation of symptoms severity on infected roots, and screening assays for breeding programs. However, a detailed molecular view on the early interaction between M. cannonballus and melon roots in either susceptible or resistant genotypes is lacking. In the present study, we used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes, Cucumis melo 'Piel de sapo' ('PS') and C. melo 'Pat 81', with contrasting resistance to the disease. This study was carried out at 1 and 3 days after infection (DPI) by M. cannonballus. Results: Our results indicate a dissimilar behavior of the susceptible vs. the resistant genotypes from 1 to 3 DPI. 'PS' responded with a more rapid infection response than 'Pat 81' at 1 DPI. At 3 DPI the total number of differentially expressed genes identified in 'PS' declined from 451 to 359, while the total number of differentially expressed transcripts in 'Pat 81' increased from 187 to 849. Several deregulated transcripts coded for components of Ca2+ and jasmonic acid (JA) signalling pathways, as well as for other proteins related to defence mechanisms. Transcriptional differences in the activation of the JA-mediated response in 'Pat 81' compared to 'PS' suggested that JA response might be partially responsible for their observed differences in resistance. Conclusions: As a result of this study we have identified for the first time a set of candidate genes involved in the root response to the infection of the pathogen causing melon vine decline. This information is useful for understanding the disease progression and resistance mechanisms few days after inoculation.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: [NiFe] hydrogenases are enzymes that catalyze the oxidation of hydrogen into protons and electrons, to use H2 as energy source, or the production of hydrogen through proton reduction, as an escape valve for the excess of reduction equivalents in anaerobic metabolism. Biosynthesis of [NiFe] hydrogenases is a complex process that occurs in the cytoplasm, where a number of auxiliary proteins are required to synthesize and insert the metal cofactors into the enzyme structural units. The endosymbiotic bacterium Rhizobium leguminosarum requires the products of eighteen genes (hupSLCDEFGHIJKhypABFCDEX) to synthesize an active hydrogenase. hupF and hupK genes are found only in hydrogenase clusters from bacteria expressing hydrogenase in the presence of oxygen. Results: HupF is a HypC paralogue with a similar predicted structure, except for the C-terminal domain present only in HupF. Deletion of hupF results in the inability to process the hydrogenase large subunit HupL, and also in reduced stability of this subunit when cells are exposed to high oxygen tensions. A DeltahupF mutant was fully complemented for hydrogenase activity by a C-terminal deletion derivative under symbiotic, ultra low-oxygen tensions, but only partial complementation was observed in free living cells under higher oxygen tensions (1% or 3%). Co-purification experiments using StrepTag-labelled HupF derivatives and mass spectrometry analysis indicate the existence of a major complex involving HupL and HupF, and a less abundant HupF-HupK complex. Conclusions: The results indicate that HupF has a dual role during hydrogenase biosynthesis: it is required for hydrogenase large subunit processing and it also acts as a chaperone to stabilize HupL when hydrogenase is synthesized in the presence of oxygen.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Blood coagulation is an essential determinant of coronary artery disease (CAD). Soluble Endothelial Protein C Receptor (sEPCR) may be a biomarker of a hypercoagulable state. We prospectively investigated the relationship between plasma sEPCR levels and the risk of cardiovascular events (CVE). Methods: We measured baseline sEPCR levels in 1673 individuals with CAD (521 with acute coronary syndrome [ACS] and 1152 with stable angina pectoris [SAP]) from the AtheroGene cohort. During a median follow up of 3.7 years, 136 individuals had a CVE. In addition, 891 of these CAD patients were genotyped for the PROCR rs867186 (Ser219Gly) variant. Results: At baseline, sEPCR levels were similar in individuals with ACS and SAP (median: 111 vs. 115 ng/mL respectively; p=0.20). Increased sEPCR levels were found to be associated with several cardiovascular risk factors including gender (p=0.006), soluble Tissue Factor levels (p=0.0001), diabetes (p=0.0005), and factors reflecting impaired renal function such as creatinine and cystatin C (p
    Digitale ISSN: 1471-2350
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 70
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Fungal load quantification is a critical component of fungal community analyses. Limitation of current approaches for quantifying the fungal component in the human microbiome suggests the need for new broad-coverage techniques. Methods: We analyzed 2,085 18S rRNA gene sequences from the SILVA database for assay design. We generated and quantified plasmid standards using a qPCR-based approach. We evaluated assay coverage against 4,968 sequences and performed assay validation following the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines. Results: We designed FungiQuant, a TaqMan(R) qPCR assay targeting a 351 bp region in the fungal 18S rRNA gene. Our in silico analysis showed that FungiQuant is a perfect sequence match to 90.0% of the 2,617 fungal species analyzed. We showed that FungiQuant's is 100% sensitive and its amplification efficiencies ranged from 76.3% to 114.5%, with r2-values of 〉0.99 against the 69 fungal species tested. Additionally, FungiQuant inter- and intra-run coefficients of variance ranged from
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Hyperelastosis cutis is an inherited autosomal recessive connective tissue disorder. Affected horses are characterized by hyperextensible skin, scarring, and severe lesions along the back. The disorder is caused by a mutation in cyclophilin B. Results: The crystal structures of both wild-type and mutated (Gly6-〉Arg) horse cyclophilin B are presented. The mutation neither affects the overall fold of the enzyme nor impairs the catalytic site structure. Instead, it locally rearranges the flexible N-terminal end of the polypeptide chain and also makes it more rigid. Conclusions: Interactions of the mutated cyclophilin B with a set of endoplasmic reticulum-resident proteins must be affected.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 72
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: In plants, a large family of calmodulin (CaM) and CaM-like (CML) proteins transduce the increase in cytosolic Ca2+ concentrations by binding to and altering the activities of target proteins, and thereby affecting the physiological responses to a vast array of stimuli. Here, transcript expression analysis of Cam and CML gene family members in rice (Oryza sativa L.) was extensively examined. Results: Cam and CML genes in rice exhibited differential expression patterns in tissues/organs. Under osmotic stress and salt stress, expression of OsCam1-1, OsCML4, 5, 8, and 11 was induced with different kinetics and magnitude. OsCML4 and 8 mRNA levels significantly increased by 3 h after treatment and remained elevated for at least 24 h while expression of OsCam1-1, OsCML5 and 11 was up-regulated as early as 1--3 h before rapidly returning to normal levels. Several cis-acting elements in response to abiotic stresses, including DREs (important promoter elements responsive to drought, high salt, and cold stress), were detected in the 5[prime] upstream regions of these genes. The observed induction of the GUS activity of transgenic rice plants via the OsCam1-1 promoter appeared to be biphasic and dependent on the severity of salt stress. Conclusions: Large OsCam and OsCML gene family members likely play differential roles as signal transducers in regulating various developmental processes and represent important nodes in the signal transduction and transcriptional regulation networks in abiotic stresss responses mediated by the complex Ca2+ signals in plants, which are rich in both spatial and temporal information.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 73
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Plant microRNAs (miRNAs) play key roles in the transcriptional responses to environmental stresses. However, the role of miRNAs in responses to insect herbivory has not been thoroughly explored. To identify herbivory-responsive miRNAs, we first identified conserved miRNAs in the ecological model plant Nicotiana attenuata whose interactions with herbivores have been well-characterized in both laboratory and field studies. Results: We identified 59 miRNAs from 36 families, and two endogenous trans-acting small interfering RNAs (tasiRNA) targeted by miRNAs. We characterized the response of the precursor and mature miRNAs to simulated attack from the specialist herbivore Manduca sexta by quantitative PCR analysis and used ir-aoc RNAi transformants, deficient in jasmonate biosynthesis, to identify jasmonate-dependent and -independent miRNA regulation. Expression analysis revealed that groups of miRNAs and tasiRNAs were specifically regulated by either mechanical wounding or wounding plus oral secretions from M. sexta larvae, and these small RNAs were accumulated in jasmonate-dependent or -independent manners. Moreover, cDNA microarray analysis indicated that the expression patterns of the corresponding target genes were correlated with the accumulation of miRNAs and tasiRNAs. Conclusions: We show that a group of miRNAs and tasiRNAs orchestrates the expression of target genes involved in N. attenuata's responses to herbivore attack.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 74
    Publikationsdatum: 2012-11-09
    Beschreibung: Background: Estrogen receptors alpha (ER) are implicated in many types of female cancers, and are the common target for anti-cancer therapy using selective estrogen receptor modulators (SERMs, such as tamoxifen). However, cell-type specific and patient-to-patient variability in response to SERMs (from suppression to stimulation of cancer growth), as well as frequent emergence of drug resistance, represents a serious problem. The molecular processes behind mixed effects of SERMs remain poorly understood, and this strongly motivates application of systems approaches. In this work, we aimed to establish a mathematical model of ER-dependent gene expression to explore potential mechanisms underlying the variable actions of SERMs. Results: We developed an equilibrium model of ER binding with 17beta-estradiol, tamoxifen and DNA, and linked it to a simple ODE model of ER-induced gene expression. The model was parameterised on the broad range of literature available experimental data, and provided a plausible mechanistic explanation for the dual agonism/antagonism action of tamoxifen in the reference cell line used for model calibration. To extend our conclusions to other cell types we ran global sensitivity analysis and explored model behaviour in the wide range of biologically plausible parameter values, including those found in cancer cells. Our findings suggest that transcriptional response to tamoxifen is controlled in a complex non-linear way by several key parameters, including ER expression level, hormone concentration, amount of ER-responsive genes and the capacity of ER-tamoxifen complexes to stimulate transcription (e.g. by recruiting co-regulators of transcription). The model revealed non-monotonic dependence of ER-induced transcriptional response on the expression level of ER, that was confirmed experimentally in four variants of the MCF-7 breast cancer cell line. Conclusions: We established a minimal mechanistic model of ER-dependent gene expression, that predicts complex non-linear effects in transcriptional response to tamoxifen in the broad range of biologically plausible parameter values. Our findings suggest that the outcome of a SERM's action is defined by several key components of cellular micro-environment, that may contribute to cell-type-specific effects of SERMs and justify the need for the development of combinatorial biomarkers for more accurate prediction of the efficacy of SERMs in specific cell types.
    Digitale ISSN: 1752-0509
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Publikationsdatum: 2012-11-09
    Beschreibung: Publication year: 2012 Source: Cell Reports Hong Zan, Clayton A. White, Lisa M. Thomas, Thach Mai, Guideng Li, Zhenming Xu, Jinsong Zhang, Paolo Casali By diversifying the biological effector functions of antibodies, class switch DNA recombination (CSR) plays a critical role in the maturation of the immune response. It is initiated by activation-induced cytidine deaminase (AID)-mediated deoxycytosine deamination, yielding deoxyuridine (dU), and dU glycosylation by uracil DNA glycosylase (Ung) in antibody switch (S) region DNA. Here we showed that the translesion DNA synthesis polymerase Rev1 directly interacted with Ung and targeted in an AID-dependent and Ung-independent fashion the S regions undergoing CSR. Rev1 −/− Ung +/+ B cells reduced Ung recruitment to S regions, DNA-dU glycosylation, and CSR. Together with an S region spectrum of mutations similar to that of Rev1 +/+ Ung −/− B cells, this suggests that Rev1 operates in the same pathway as Ung, as emphasized by further decreased CSR in Rev1 −/− Msh2 −/− B cells. Rescue of CSR in Rev1 −/− B cells by a catalytically inactive Rev1 mutant shows that the important role of Rev1 in CSR is mediated by Rev1’s scaffolding function, not its enzymatic function. Graphical abstract Graphical Abstract Highlights ► Rev1 DNA polymerase plays an important role in class switch DNA recombination ► This role is mediated by Rev1’s scaffolding function, not its enzymatic function ► Rev1 interacts with Ung and recruits it to switch region DNA ► Rev1 enhances Ung-mediated dU glycosylation in DNA
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 76
    Publikationsdatum: 2012-11-09
    Beschreibung: Publication year: 2012 Source: Cell Reports Michihiko Sugimoto, Masayo Kondo, Michiko Hirose, Misao Suzuki, Kazuyuki Mekada, Takaya Abe, Hiroshi Kiyonari, Atsuo Ogura, Nobuo Takagi, Karen Artzt, Kuniya Abe After implantation, pluripotent epiblasts are converted to embryonic ectoderm through cell–cell interactions that significantly change the transcriptional and epigenetic networks. An entrée to understanding this vital developmental transition is the t w5 mutation of the mouse t complex. This mutation produces highly specific defects in the embryonic ectoderm before gastrulation, leading to death of the embryonic ectoderm. Using a positional cloning approach, we have now identified the mutated gene, completing a decades-long search. The gene, vacuolar protein sorting 52 ( Vps52 ), is a mouse homolog of yeast VPS52 that is involved in the retrograde trafficking of endosomes. Our data suggest that Vps52 acts in extraembryonic tissues to support the growth and differentiation of embryonic ectoderm via cell–cell interactions. It is also required in the formation of embryonic structures at a later stage of development, revealing hitherto unknown functions of Vps52 in the development of a multicellular organism. Graphical abstract Graphical Abstract Highlights ► Vps52 , part of retrograde transport to the Golgi, causes the t w5 lethal phenotype ► Vps52 acts in extraembryonic tissues to dictate embryonic ectoderm differentiation ► VPS52’s essential function in the embryo involves cell–cell interactions ► VPS52 also has an indispensable function later in development
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 77
    facet.materialart.
    Unbekannt
    Elsevier
    Publikationsdatum: 2012-11-09
    Beschreibung: Publication year: 2012 Source: Cell Reports Myrto Denaxa, Melanie Kalaitzidou, Anna Garefalaki, Angeliki Achimastou, Reena Lasrado, Tamara Maes, Vassilis Pachnis The generation of cortical interneuron subtypes is controlled by genetic programs that are activated in the ventral forebrain and unfold during the prolonged period of inhibitory neuron development. The LIM-homeodomain protein LHX6 is critical for the development of all cortical interneurons originating in the medial ganglionic eminence, but the molecular mechanisms that operate downstream of LHX6 to control the terminal differentiation of somatostatin- and parvalbumin-expressing interneurons within the cortex remain unknown. Here, we provide evidence that the nuclear matrix and genome organizer protein SATB1 is induced by neuronal activity and functions downstream of Lhx6 to control the transition of tangentially migrating immature interneurons into the terminally differentiated Somatostatin (SST)-expressing subtype. Our experiments provide a molecular framework for understanding the genetic and epigenetic mechanisms by which specified but immature cortical interneurons acquire the subtype-defining molecular and morphophysiological characteristics that allow them to integrate and function within cortical circuits. Graphical abstract Graphical Abstract Highlights ► Satb1 is specifically expressed in MGE-derived cortical interneurons ► Satb1 is required for the maturation of MGE-derived cortical interneurons in vivo ► Satb1 promotes the maturation of SST+ cortical interneurons downstream of Lhx6 ► Neuronal activity induces expression of Satb1 in immature cortical interneurons
    Digitale ISSN: 2211-1247
    Thema: Biologie
    Publiziert von Elsevier im Namen von Cell Press.
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  • 78
    Publikationsdatum: 2012-11-09
    Beschreibung: Pyrolysis(pyr)-GC/MS analysis of characteristic thermal decomposition fragments has been previously used for qualitative fingerprinting of organic sources in environmental samples. A quantitative pyr-GC/MS method based on characteristic tire polymer pyrolysis products was developed for tread particle quantification in environmental matrices including soil, sediment, and air. The feasibility of quantitative pyr-GC/MS analysis of tread was confirmed in a method evaluation study using artificial soil spiked with known amounts of cryogenically generated tread. Tread concentration determined by blinded analyses was highly correlated (r2 ³ 0.88) with the known tread spike concentration. Two critical refinements to the initial pyrolysis protocol were identified including use of an internal standard and quantification by the dimeric markers vinylcyclohexene and dipentene, which have good specificity for rubber polymer with no other appreciable environmental sources. A novel use of deuterated internal standards of similar polymeric structure was developed to correct the variable analyte recovery caused by sample size, matrix effects, and ion source variability. The resultant quantitative pyr-GC/MS protocol is reliable and transferable between laboratories.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
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  • 79
    Publikationsdatum: 2012-11-09
    Beschreibung: After publication of this manuscript [Lipids in Health and Disease 2012, 11:95], we noted that one of the monounsaturated fatty acid isomers had been mislabelled in the results, and in figure 2A and table 2.In the Results and discussion, the sentence, "Concerning plasma MUFA levels, long-chain MUFA C20:1 (n-9 and n-7) and C22:1 (n-11 and n-9) peaked at 2 hr post-ingestion (Figure 2a and b)" should read, "Concerning plasma MUFA levels, long-chain MUFA C20:1 (n-11, n-9 and n-7) and C22:1 (n-11 and n-9) peaked at 2 hr post-ingestion (Figure 2a and b)".The figure and table have also been corrected (figure 1, table 1).We apologize for this error, which was due to a misreading of the gas chromatography reading.
    Digitale ISSN: 1476-511X
    Thema: Biologie
    Publiziert von BioMed Central
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  • 80
    facet.materialart.
    Unbekannt
    BioMed Central
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: The inference of homologies among DNA sequences, that is, positions in multiple genomes that share a common evolutionary origin, is a crucial, yet difficult task facing biologists. Its computational counterpart is known as the multiple sequence alignment problem. There are various criteria and methods available to perform multiple sequence alignments, and among these, the minimization of the overall cost of the alignment on a phylogenetic tree is known in combinatorial optimization as the Tree Alignment Problem. This problem typically occurs as a subproblem of the Generalized Tree Alignment Problem, which looks for the tree with the lowest alignment cost among all possible trees. This is equivalent to the Maximum Parsimony problem when the input sequences are not aligned, that is, when phylogeny and alignments are simultaneously inferred. Results: For large data sets, a popular heuristic is Direct Optimization (DO). DO provides a good tradeoff between speed, scalability, and competitive scores, and is implemented in the computer program POY. All other (competitive) algorithms have greater time complexities compared to DO. Here, weintroduce and present experiments a new algorithm Affine-DO to accommodate the indel (alignment gap) models commonly used in phylogenetic analysis of molecular sequence data. Affine-DO has the same time complexity as DO, but is correctly suited for the affine gap edit distance. We demonstrateits performance with more than 330,000 experimental tests. These experiments show that the solutions of Affine-DO are close to the lower bound inferred from a linear programming solution. Moreover, iterating over a solution produced using Affine-DO shows little improvement. Conclusions: Our results show that Affine-DO is likely producing near-optimal solutions, with approximations within 10% for sequences with small divergence, and within 30% for random sequences, for which Affine-DO produced the worst solutions. The Affine-DO algorithm has the necessary scalability andoptimality to be a significant improvement in the real-world phylogenetic analysis of sequence data.
    Digitale ISSN: 1471-2105
    Thema: Biologie , Informatik
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 81
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: Previous work has shown that leaf-cutting ants prefer to cut leaf material with relatively low fungal endophyte content. This preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in their host plants' defense against leaf-cutting ants. To measure the long-term cost to the ant colony of fungal endophytes in their forage material, we conducted a 20-week laboratory experiment to measure fungal garden development for colonies that foraged on leaves with low or high endophyte content. Results: Colony mass and the fungal garden dry mass did not differ significantly between the low and high endophyte feeding treatments. There was, however, a marginally significant trend toward greater mass of fungal garden per ant worker in the low relative to the high endophyte treatment. This trend was driven by differences in the fungal garden mass per worker from the earliest samples, when leaf-cutting ants had been foraging on low or high endophyte leaf material for only 2 weeks. At two weeks of foraging, the mean fungal garden mass per worker was 77% greater for colonies foraging on leaves with low relative to high endophyte loads. Conclusions: Our data suggest that the cost of endophyte presence in ant forage material may be greatest to fungal colony development in its earliest stages, when there are few workers available to forage and to clean leaf material. This coincides with a period of high mortality for incipient colonies in the field. We discuss how the endophyte-leaf-cutter ant interaction may parallel constitutive defenses in plants, whereby endophytes reduce the rate of colony development when its risk of mortality is greatest.
    Digitale ISSN: 1472-6785
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 82
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: Extant sauropsids (reptiles and birds) are divided into two major lineages, the lineage of Testudines (turtles) and Archosauria (crocodilians and birds) and the lineage of Lepidosauria (tuatara, lizards, worm lizards and snakes). Karyotypes of these sauropsidan groups generally consist of macrochromosomes and microchromosomes. In chicken, microchromosomes exhibit a higher GC-content than macrochromosomes. To examine the pattern of intra-genomic GC heterogeneity in lepidosaurian genomes, we constructed a cytogenetic map of the Japanese four-striped rat snake (Elaphe quadrivirgata) with 183 cDNA clones by fluorescence in situ hybridization, and examined the correlation between the GC-content of exonic third codon positions (GC3) of the genes and the size of chromosomes on which the genes were localized. Results: Although GC3 distribution of snake genes was relatively homogeneous compared with those of the other amniotes, microchromosomal genes showed significantly higher GC3 than macrochromosomal genes as in chicken. Our snake cytogenetic map also identified several conserved segments between the snake macrochromosomes and the chicken microchromosomes. Cross-species comparisons revealed that GC3 of most snake orthologs in such macrochromosomal segments were GC-poor (GC3 〈 50%) whereas those of chicken orthologs in microchromosomes were relatively GC-rich (GC3 〉= 50%). Conclusion: Our results suggest that the chromosome size-dependent GC heterogeneity had already occurred before the lepidosaur-archosaur split, 275 million years ago. This character was probably present in the common ancestor of lepidosaurs and but lost in the lineage leading to Anolis during the diversification of lepidosaurs. We also identified several genes whose GC-content might have been influenced by the size of the chromosomes on which they were harbored over the course of sauropsid evolution.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 83
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: Patient-reported Outcomes (PROs) capturing e.g., quality of life, fatigue, depression, medication side-effects or disease symptoms, have become important outcome parameters in medical research and daily clinical practice. Electronic PRO data capture (ePRO) with software packages to administer questionnaires, storing data, and presenting results has facilitated PRO assessment in hospital settings. Compared to conventional paper-pencil versions of PRO instruments, ePRO is more economical with regard to staff resources and time, and allows immediate presentation of results to the medical staff.The objective of our project was to develop software (CHES -- Computer-based Health Evaluation System) for ePRO in hospital settings and at home with a special focus on the presentation of individual patient's results. Methods: Following the Extreme Programming development approach architecture was not fixed up-front, but was done in close, continuous collaboration with software end users (medical staff, researchers and patients) to meet their specific demands. Developed features include sophisticated, longitudinal charts linking patients' PRO data to clinical characteristics and to PRO scores from reference populations, a web-interface for questionnaire administration, and a tool for convenient creating and editing of questionnaires. Results: By 2012 CHES has been implemented at various institutions in Austria, Germany, Switzerland, and the UK and about 5000 patients participated in ePRO (with around 15000 assessments in total). Data entry is done by the patients themselves via tablet PCs with a study nurse or an intern approaching patients and supervising questionnaire completion.DiscussionDuring the last decade several software packages for ePRO have emerged for different purposes. Whereas commercial products are available primarily for ePRO in clinical trials, academic projects have focused on data collection and presentation in daily clinical practice and on extending cancer registries with PRO data. CHES includes several features facilitating the use of PRO data for individualized medical decision making. With its web-interface it allows ePRO also when patients are home. Thus, it provides complete monitoring of patients'physical and psychosocial symptom burden.
    Digitale ISSN: 1472-6947
    Thema: Informatik , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 84
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: Several methods have recently been developed to identify regions of the genome that have been exposed to strong selection. However, recent theoretical and empirical work suggests that polygenic models are required to identify the genomic regions that are more moderately responding to ongoing selection on complex traits. We examine the effects of multi-trait selection on the genome of a population of US registered Angus beef cattle born over a 50-year period representing approximately 10 generations of selection. We present results from the application of a quantitative genetic model, called Birth Date Selection Mapping, to identify signatures of recent ongoing selection. Results: We show that US Angus cattle have been systematically selected to alter their mean additive genetic merit for most of the 16 production traits routinely recorded by breeders. Using Birth Date Selection Mapping, we estimate the time-dependency of allele frequency for 44,817 SNP loci using genomic best linear unbiased prediction, generalized least squares, and BayesCpi analyses. Finally, we reconstruct the primary phenotypes that have historically been exposed to selection from a genome-wide analysis of the 16 production traits and gene ontology enrichment analysis. Conclusions: We demonstrate that Birth Date Selection Mapping utilizing mixed models corrects for time-dependent pedigree sampling effects that lead to spurious SNP associations and reveals genomic signatures of ongoing selection on complex traits. Because multiple traits have historically been selected in concert and most quantitative trait loci have small effects, selection has incrementally altered allele frequencies throughout the genome. Two quantitative trait loci of large effect were not the most strongly selected of the loci due to their antagonistic pleiotropic effects on strongly selected phenotypes. Birth Date Selection Mapping may readily be extended to temporally-stratified human or model organism populations.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 85
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: The rise of high mountain chains is widely seen as one of the factors driving rapid diversification of land plants and the formation of biodiversity hotspots. Supporting evidence was reported for the impact of the rapid rise of the Andean mountains but this hypothesis has so far been less explored for the impact of the "roof of the world". The formation of the Himalaya, and especially the rise of the Qinghai--Tibetan Plateau in the recent 20 million years, altered the monsoon regimes that dominate the current climates of South East Asia. Here, we infer the hypothesis that the rise of Himalaya had a strong impact on the plant diversity in the biodiversity hotspot of the Southwest Chinese Mountains. Results: Our analyses of the diversification pattern of the derived fern genus Lepisorus recovered evidence for changes in plant diversity that correlated with the strengthening of South East Asian monsoon. Southwest China or Southwest China and Japan was recovered as the putative area of origin of Lepisorus and enhancing monsoon regime were found to shape the early diversification of the genus as well as subsequent radiations during the late Miocene and Pliocene. Conclusions: We report new evidence for a coincidence of plant diversification and changes of the climate caused by the uplift of the Himalaya. These results are discussed in the context of the impact of incomplete taxon sampling, uncertainty of divergence time estimates, and limitations of current methods used to assess diversification rates.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 86
    Publikationsdatum: 2012-11-10
    Beschreibung: Background: Breast cancer is one of the leading causes of cancer morbidity and mortality worldwide. In Cameroon, breast cancer causes as many as 10.7 deaths per 100,000 women making it the second cause of cancer mortality. Better documenting women's knowledge and practices on breast cancer and breast self-exam (BSE) would be useful in the design of interventions aimed at preventing breast cancer. This study sought to 1. describe Cameroonian women's knowledge of breast self-examination (BSE); 2. assess their impression on the practice of BSE and 3. describe their perceptions on the causes, risk factors and prevention of breast cancer. Methods: A cross-sectional survey was conducted in a volunteer sample of 120 consenting women in Buea, Cameroon. Data were collected using a structured questionnaire self-administered by study participants. Results: The sample was fairly educated with close to three quarters (70.83%) having completed high school. Nearly three quarters (74.17%) of participants had previously heard about BSE, however as many as 40% had never done a BSE. Although 95% of participants believed that breast cancer could be prevented, only 36.67% recognized breast examination as a prevention method. A substantial 13.33% thought that breast cancer could be prevented with a vaccine while 45% thought that dieting or exercising would prevent breast cancer. Similarly, 70% of participants thought that breast cancer could be treated, with 35.83% thinking that it could be treated medically while 34.17% thought it could be treated traditionally or spiritually. Conclusions: The practice of BSE while perceived as being important is not frequent in these women in Buea, Cameroon. Health education campaigns are imperative to elucidate the public on the causes, risk factors and prevention of breast cancer. Further studies need to explore what interventions could be best used to improve the uptake and practice of BSE.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 87
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: Cultivated peanut or groundnut (Arachis hypogaea L.) is an important oilseed crop with an allotetraploid genome (AABB, 2n = 4x = 40). Both the low level of genetic variation within the cultivated gene pool and its polyploid nature limit the utilization of molecular markers to explore genome structure and facilitate genetic improvement. Nevertheless, a wealth of genetic diversity exists in diploid Arachis species (2n = 2x = 20), which represent a valuable gene pool for cultivated peanut improvement. Interspecific populations have been used widely for genetic mapping in diploid species of Arachis. However, an intraspecific mapping strategy was essential to detect chromosomal rearrangements among species that could be obscured by mapping in interspecific populations. To develop intraspecific reference linkage maps and gain insights into karyotypic evolution within the genus, we comparatively mapped the A- and B-genome diploid species using intraspecific F2 populations. Exploring genome organization among diploid peanut species by comparative mapping will enhance our understanding of the cultivated tetraploid peanut genome. Moreover, new sources of molecular markers that are highly transferable between species and developed from expressed genes will be required to construct saturated genetic maps for peanut. Results: A total of 2,138 EST-SSR (expressed sequence tag-simple sequence repeat) markers were developed by mining a tetraploid peanut EST assembly including 101,132 unigenes (37,916 contigs and 63,216 singletons) derived from 70,771 long-read (Sanger) and 270,957 short-read (454) sequences. A set of 97 SSR markers were also developed by mining 9,517 genomic survey sequences of Arachis. An SSR-based intraspecific linkage map was constructed using an F2 population derived from a cross between K 9484 (PI 298639) and GKBSPSc 30081 (PI 468327) in the B - genome species A. batizocoi. A high degree of macrosynteny was observed when comparing the homoeologous linkage groups between A (A. duranensis) and B (A. batizocoi) genomes. Comparison of the A - and B - genome genetic linkage maps also showed a total of five inversions and one major reciprocal translocation between two pairs of chromosomes under our current mapping resolution. Conclusions: Our findings will contribute to understanding tetraploid peanut genome origin and evolution and eventually promote its genetic improvement. The newly developed EST-SSR markers will enrich current molecular marker resources in peanut.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
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  • 88
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: Hypertrophic Cardiomyopathy (HCM) is a genetically heterogeneous disease. One specific mutation in the MYBPC3 gene is highly prevalent in center east of France giving an opportunity to define the clinical profile of this specific mutation. Methods: HCM probands were screened for mutation in the MYH7, MYBPC3, TNNT2 and TNNI3 genes. Carriers of the MYBPC3 IVS20-2A〉G mutation were genotyped with 8 microsatellites flanking this gene. The age of this MYBPC3 mutation was inferred with the software ESTIAGE. The age at first symptom, diagnosis, first complication, first severe complication and the rate of sudden death were compared between carriers of the IVS20-2 mutation (group A) and carriers of all other mutations (group B) using time to event curves and log rank test. Results: Out of 107 HCM probands, 45 had a single heterozygous mutation in one of the 4 tested sarcomeric genes including 9 patients with the MYBPC3 IVS20-2A〉G mutation. The IVS20-2 mutation in these 9 patients and their 25 mutation carrier relatives was embedded in a common haplotype defined after genotyping 4 polymorphic markers on each side of the MYBPC3 gene. This result supports the hypothesis of a common ancestor. Furthermore, we evaluated that the mutation occurred about 47 generations ago, approximately at the 10th century.We then compared the clinical profile of the IVS20-2 mutation carriers (group A) and the carriers of all other mutations (group B). Age at onset of symptoms was similar in the 34 group A cases and the 73 group B cases but group A cases were diagnosed on average 15 years later (log rank test p = 0.022). Age of first complication and first severe complication was delayed in group A vs group B cases but the prevalence of sudden death and age at death was similar in both groups. Conclusion: A founder mutation arising at about the 10th century in the MYBPC3 gene accounts for 8.4% of all HCM in center east France and results in a cardiomyopathy starting late and evolving slowly but with an apparent risk of sudden death similar to other sarcomeric mutations.
    Digitale ISSN: 1471-2350
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: Extensive studies have demonstrated that the COBRA gene is critical for biosynthesis of cell wall constituents comprising structural tissues of roots, stalks, leaves and other vegetative organs, however, its role in fruit development and ripening remains largely unknown. Results: We identified a tomato gene (SlCOBRA-like) homologous to Arabidopsis COBRA, and determined its role in fleshy fruit biology. The SlCOBRA-like gene is highly expressed in vegetative organs and in early fruit development, but its expression in fruit declines dramatically during ripening stages, implying a primary role in early fruit development. Fruit-specific suppression of SlCOBRA-like resulted in impaired cell wall integrity and up-regulation of genes encoding proteins involved in cell wall degradation during early fruit development. In contrast, fruit-specific overexpression of SlCOBRA-like resulted in increased wall thickness of fruit epidermal cells, more collenchymatous cells beneath the epidermis, elevated levels of cellulose and reduced pectin solubilization in the pericarp cells of red ripe fruits. Moreover, transgenic tomato fruits overexpressing SlCOBRA-like exhibited desirable early development phenotypes including enhanced firmness and a prolonged shelf life. Conclusions: Our results suggest that SlCOBRA-like plays an important role in fruit cell wall architecture and provides a potential genetic tool for extending the shelf life of tomato and potentially additional fruits.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: Experimental datasets are becoming larger and increasingly complex, spanning different data domains, thereby expanding the requirements for respective tool support for their analysis. Networks provide a basis for the integration, analysis and visualization of multi-omics experimental datasets. Results: Here we present VANTED (version 2), a framework for systems biology applications, which comprises a comprehensive set of seven main tasks. These range from network reconstruction, data visualization, integration of various data types, network simulation to data exploration combined with a manifold support of systems biology standards for visualization and data exchange. The offered set of functionalities is instantiated by combining several tasks in order to enable users to view and explore a comprehensive dataset from different perspectives. We describe the system as well as an exemplary workflow. Conclusions: VANTED is a stand-alone framework which supports scientists during the data analysis and interpretation phase. It is available as a Java open source tool from http://www.vanted.org.
    Digitale ISSN: 1752-0509
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: Empirical evaluations of sexually dimorphic expression of genes on the mammalian X-chromosome are needed to understand the evolutionary forces and the gene-regulatory mechanisms controlling this chromosome. We performed a large-scale sex-bias expression analysis of genes on the X-chromosome in six different somatic tissues from mouse. Results: Our results show that the mouse X-chromosome is enriched with female-biased genes and depleted of male-biased genes. This suggests that feminisation as well as de-masculinisation of the X-chromosome has occurred in terms of gene expression in non-reproductive tissues. Several mechanisms may be responsible for the control of female-biased expression on chromosome X, and escape from X-inactivation is a main candidate. We confirmed escape in case of Tmem29 using RNA-FISH analysis. In addition, we identified novel female-biased non-coding transcripts located in the same female-biased cluster as the well-known coding X-inactivation escapee Kdm5c, likely transcribed from the transition-region between active and silenced domains. We also found that previously known escapees only partially explained the overrepresentation of female-biased X-genes, particularly for tissue-specific female-biased genes. Therefore, the gene set we have identified contains tissue-specific escapees and/or genes controlled by other sexually skewed regulatory mechanisms. Analysis of gene age showed that evolutionarily old X-genes (〉0100 myr, preceding the radiation of placental mammals) are more frequently female-biased than younger genes. Conclusion: Altogether, our results have implications for understanding both gene regulation and gene evolution of mammalian X-chromosomes, and suggests that the final result in terms of the X-gene composition (masculinisation versus feminisation) is a compromise between different evolutionary forces acting on reproductive and somatic tissues.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
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  • 92
    Publikationsdatum: 2012-11-11
    Beschreibung: Background: The genomes of three major mosquito vectors of human diseases, Anopheles gambiae, Aedes aegypti, and Culex pipiens quinquefasciatus, have been previously sequenced. C. p. quinquefasciatus has the largest number of predicted protein-coding genes, which partially results from the expansion of three detoxification gene families: cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST), and carboxyl/cholinesterases (CCE). However, unlike An. gambiae and Ae. aegypti, which have large amounts of gene expression data, C. p. quinquefasciatus has limited transcriptomic resources. Knowledge of complete gene expression information is very important for the exploration of the functions of genes involved in specific biological processes. In the present study, the three detoxification gene families of C. p. quinquefasciatus were analyzed for phylogenetic classification and compared with those of three other dipteran insects. Gene expression during various developmental stages and the differential expression responsible for parathion resistance were profiled using the digital gene expression (DGE) technique. Results: A total of 302 detoxification genes were found in C. p. quinquefasciatus, including 71 CCE, 196 P450, and 35 cytosolic GST genes. Compared with three other dipteran species, gene expansion in Culex mainly occurred in the CCE and P450 families, where the genes of alpha-esterases, juvenile hormone esterases, and CYP325 of the CYP4 subfamily showed the most pronounced expansion on the genome. For the five DGE libraries, 3.5-3.8 million raw tags were generated and mapped to 13314 reference genes. Among 302 detoxification genes, 225 (75%) were detected for expression in at least one DGE library. One fourth of the CCE and P450 genes were detected uniquely in one stage, indicating potential developmentally regulated expression. A total of 1511 genes showed different expression levels between a parathion-resistant and a susceptible strain. Fifteen detoxification genes, including 2 CCEs, 6 GSTs, and 7 P450s, were expressed at higher levels in the resistant strain. Conclusions: The results of the present study provide new insights into the functions and evolution of three detoxification gene families in mosquitoes and comprehensive transcriptomic resources for C. p. quinquefasciatus, which will facilitate the elucidation of molecular mechanisms underlying the different biological characteristics of the three major mosquito vectors.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Publikationsdatum: 2012-11-12
    Beschreibung: Background: The problem list is a key part of the electronic health record (EHR) that allows practitioners to see a patient's diagnoses and health issues. Yet, as the content of the problem list largely represents the subjective decisions of those who edit it, patients' problem lists are often unreliable when shared across practitioners. The lack of standards for how the problem list is compiled in the EHR limits its effectiveness in improving patient care, particularly as a resource for clinical decision support and population management tools. The purpose of this study is to discover practitioner opinions towards the problem list and the logic behind their decisions during clinical situations.Materials and methodsAn observational cross-sectional study was conducted at two major Boston teaching hospitals. Practitioners' opinions about the problem list were collected through both in-person interviews and an online questionnaire. Questions were framed using vignettes of clinical scenarios asking practitioners about their preferred actions towards the problem list. Results: These data confirmed prior research that practitioners differ in their opinions over managing the problem list, but in most responses to a questionnaire, there was a common approach among the relative majority of respondents. Further, basic demographic characteristics of providers (age, medical experience, etc.) did not appear to strongly affect attitudes towards the problem list. Conclusion: The results supported the premise that policies and EHR tools are needed to bring about a common approach. Further, the findings helped identify what issues might benefit the most from a defined policy and the level of restriction a problem list policy should place on the addition of different types of information.
    Digitale ISSN: 1472-6947
    Thema: Informatik , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: There are several methods for quantitating bacterial cells, each with advantages and disadvantages. The most common method is bacterial plating, which has the advantage of allowing live cell assessment through colony forming unit (CFU) counts but is not well suited for high throughput screening (HTS). On the other hand, spectrophotometry is adaptable to HTS applications but does not differentiate between dead and living bacteria and has low sensitivity. Results: Here, we report a bacterial cell counting method termed Start Growth Time (SGT) that allows rapid and serial quantification of the absolute or relative number of live cells in a bacterial culture in a high throughput manner. We combined the methodology of quantitative polymerase chain reaction (qPCR) calculations with a previously described qualitative method of bacterial growth determination to develop an improved quantitative method. We show that SGT detects only live bacteria and is sensitive enough to differentiate between 40 and 400 cells/mL. SGT is based on the re-growth time required by a growing cell culture to reach a threshold, and the notion that this time is proportional to the number of cells in the initial inoculum. We show several applications of SGT, including assessment of antibiotic effects on cell viability and determination of an antibiotic tolerant subpopulation fraction within a cell population. SGT results do not differ significantly from results obtained by CFU counts. Conclusion: SGT is a relatively quick, highly sensitive, reproducible and non-laborious method that can be used in HTS settings to longitudinally assess live cells in bacterial cell cultures.
    Digitale ISSN: 1471-2180
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: Professional societies recommend shared decision making (SDM) for prostate cancer screening, however, most efforts have promoted informed rather than shared decision making. The objective of this study is to 1) examine the effects of a prostate cancer screening intervention to promote SDM and 2) determine whether framing prostate information in the context of other clearly beneficial men's health services affects decisions. Methods: We conducted two separate randomized controlled trials of the same prostate cancer intervention (with or without additional information on more clearly beneficial men's health services). For each trial, we enrolled a convenience sample of 2 internal medicine practices, and their interested physicians and male patients with no prior history of prostate cancer (for a total of 4 practices, 28 physicians, and 128 men across trials). Within each practice site, we randomized men to either 1) a video-based decision aid and researcher-led coaching session or 2) a highway safety video. Physicians at each site received a 1-hour educational session on prostate cancer and SDM. To assess intervention effects, we measured key components of SDM, intent to be screened, and actual screening. After finding that results did not vary by trial, we combined data across sites, adjusting for the random effects of both practice and physician. Results: Compared to an attention control, our prostate cancer screening intervention increased men's perceptions that screening is a decision (absolute difference +41%; 95% CI 25 to 57%) and men's knowledge about prostate cancer screening (absolute difference +34%; 95% CI 19% to 50%), but had no effect on men's self-reported participation in shared decisions or their participation at their preferred level. Overall, the intervention decreased screening intent (absolute difference -34%; 95% CI -50% to -18%) and actual screening rates (absolute difference -22%; 95% CI -38 to -7%) with no difference in effect by frame. Conclusions: SDM interventions can increase men's knowledge, alter their perceptions of prostate cancer screening, and reduce actual screening. However, they may not guarantee an increase in shared decisions.Trial registration#NCT00630188
    Digitale ISSN: 1472-6947
    Thema: Informatik , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: The INNER NO OUTER (INO) gene, which encodes a YABBY-type transcription factor, specifies and promotes the growth of the outer integument of the ovule in Arabidopsis. INO expression is limited to the abaxial cell layer of the developing outer integument of the ovule and is regulated by multiple regions of the INO promoter, including POS9, a positive element that when present in quadruplicate can produce low-level expression in the normal INO pattern. Results: Significant redundancy in activity between different regions of the INO promoter is demonstrated. For specific regulatory elements, multimerization or the addition of the cauliflower mosaic virus 35S general enhancer was able to activate expression of reporter gene constructs that were otherwise incapable of expression on their own. A new promoter element, POS6, is defined and is shown to include sufficient positive regulatory information to reproduce the endogenous pattern of expression in ovules, but other promoter regions are necessary to fully suppress expression outside of ovules. The full-length INO promoter, but not any of the INO promoter deletions tested, is able to act as an enhancer-blocking insulator to prevent the ectopic activation of expression by the 35S enhancer. Sequence conservation between the promoter regions of Arabidopsis thaliana, Brassica oleracea and Brassica rapa aligns closely with the functional definition of the POS6 and POS9 regions, and with a defined INO minimal promoter. The B. oleracea INO promoter is sufficient to promote a similar pattern and level of reporter gene expression in Arabidopsis to that observed for the Arabidopsis promoter. Conclusions: At least two independent regions of the INO promoter contain sufficient regulatory information to direct the specific pattern but not the level of INO gene expression. These regulatory regions act in a partially redundant manner to promote the expression in a specific pattern in the ovule and suppress expression outside of ovules. Establishment of this pattern requires cooperation and competition between multiple positive and negative regulatory elements.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: Induced defense responses to herbivores are generally believed to have evolved as cost-saving strategies that defer the fitness costs of defense metabolism until these defenses are needed. The fitness costs of jasmonate (JA)-mediated defenses have been well documented. Those of the early signaling units mediating induced resistance to herbivores have yet to be examined. Early signaling components that mediate herbivore-induced defense responses in Nicotiana attenuata, have been well characterized and here we examine their growth and fitness costs. Two mitogen-activated protein kinases (MAPKs), salicylic acid (SA)-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK) are rapidly activated after perception of herbivory and both kinases regulate herbivory-induced JA levels and JA-mediated defense metabolite accumulations. Since JA-induced defenses result in resource-based trade-offs that compromise plant productivity, we evaluated if silencing SIPK (irSIPK) and WIPK (irWIPK) benefits the growth and fitness of plants competiting with wild type (WT) plants, as has been shown for plants silenced in JA-signaling by the reduction of Lipoxygenase 3 (LOX3) levels. Results: As expected, irWIPK and irLOX3 out-performed their competing WT plants. Surprisingly, irSIPK plants, which have the largest reductions in JA signaling, did not out-perform their competing WT plants. Phytohormone profiling of leaves revealed that irSIPK plants accumulated higher levels of SA compared to WT. To test the hypothesis that these higher levels of SA, and their presumed associated fitness costs of pathogen associated defenses in irSIPK plants had nullified the JA-deficiency-mediated growth benefits in these plants, we genetically reduced SA levels in irSIPK plants. Reducing SA levels partially recovered the biomass and fitness deficits of irSIPK plants. We also evaluated whether the increased fitness of plants with reduced SA or JA levels resulted from increased nitrogen or CO2 aquisition rates, and found no evidence that greater intake of these fitness-limiting resources were responsible. Conclusions: Defense signaling mediated by herbivory-induced WIPK, but not SIPK, is associated with large fitness costs in N. attenuata, demonstrating the contrasting roles the two MAPKs play in regulating the plants' growth-defense balance. We discuss the role of SIPK as an important regulator of plant fitness, possibly by modulating SA-JA crosstalk through ethylene signaling.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: Homeodomain transcription factors play critical roles in metazoan development. BELLRINGER (BLR), one such transcription factor, is involved in diverse developmental processes in Arabidopsis, acting in vascular differentiation, phyllotaxy, flower and fruit development. BLR also has a redundant role in meristem maintenance. Cell wall remodelling underpins many of these processes, and BLR has recently been shown to regulate expression of PECTIN METHYL-ESTERASE 5 (PME5), a cell wall modifying enzyme in control of phyllotaxy.We have further explored the role of BLR in plant development by analysing phenotypes and gene expression in a series of plants over-expressing BLR, and generating combinatorial mutants with blr, brevipedicellus (bp), a member of the KNOX1 family of transcription factors that has previously been shown to interact with blr), and the homeodomain transcription factor revoluta (rev), required for radial patterning of the stem. Results: Plants over-expressing BLR exhibited a wide range of phenotypes. Some were defective in cell size and showed misregulation of genes predominantly affecting cell wall development. Other lines with more extreme phenotypes failed to generate lateral organs, consistent with BLR repressing transcription in the shoot apex.Cell wall dynamics are also affected in blr mutant plants, and BLR has previously been shown to regulate vascular development in conjunction with BP. We found that when bp and blr were combined with rev, a set of defects were observed that were distinct from those of bp blr lines. In these triple mutants xylem development was most strikingly affected, resulting in an almost complete lack of vessels and xylem parenchyma with secondary thickening. Conclusions: Our data support a role for BLR in ordering the shoot apex and, in conjunction with BP and REV, playing a part in determining the composition and organisation of the vascular system. Microarray analysis strongly indicates that the striking vascular phenotypes of blr bp rev triple mutants and plants over-expressing BLR result from the misregulation of a suite of genes, targets of BLR in wild type plants, that determine cell size and structure in the developing vasculature.
    Digitale ISSN: 1471-2229
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Publikationsdatum: 2012-11-14
    Beschreibung: Background: Interaction of non-structural protein 5A (NS5A) of Hepatitis C virus (HCV) with human kinases namely, casein kinase 1alpha (ck1alpha) and protein kinase R (PKR) have different functional implications such as regulation of viral replication and evasion of interferon induced immune response respectively. Understanding the structural and molecular basis of interactions of the viral protein with two different human kinases can be useful in developing strategies for treatment against HCV. Results: Serine 232 of NS5A is known to be phosphorylated by human ck1alpha. A structural model of NS5A peptide containing phosphoacceptor residue Serine 232 bound to ck1alpha has been generated using the known 3-D structures of kinase-peptide complexes. The substrate interacting residues in ck1alpha has been identified from the model and these are found to be conserved well in the ck1 family. ck1alpha -- substrate peptide complex has also been used to understand the structural basis of association between ck1alpha and its other viral stress induced substrate, tumour suppressor p53 transactivation domain which has a crystal structure available.Interaction of NS5A with another human kinase PKR is primarily genotype specific. NS5A from genotype 1b has been shown to interact and inhibit PKR whereas NS5A from genotype 2a/3a are unable to bind and inhibit PKR efficiently. This is one of the main reasons for the varied response to interferon therapy in HCV patients across different genotypes. Using PKR crystal structure, sequence alignment and evolutionary trace analysis some of the critical residues responsible for the interaction of NS5A 1b with PKR have been identified. Conclusions: The substrate interacting residues in ck1alpha have been identified using the structural model of kinase - substrate peptide. The PKR interacting NS5A 1b residues have also been predicted using PKR crystal structure, NS5A sequence analysis along with known experimental results. Functional significance and nature of interaction of interferon sensitivity determining region and variable region 3 of NS5A in different genotypes with PKR which was experimentally shown are also supported by the findings of evolutionary trace analysis. Designing inhibitors to prevent this interaction could enable the HCV genotype 1 infected patients respond well to interferon therapy.
    Digitale ISSN: 1472-6807
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Publikationsdatum: 2012-11-14
    Beschreibung: BMC Research Notes recently published a research article regarding the use of ligated DNA extracted from formalin-fixed paraffin embedded (FFPE) tissue on the Illumina Infinium methylation platform - "Interpretation of genome-wide infinium methylation data from ligated DNA in formalin-fixed, paraffin-embedded paired tumor and normal tissue" Jasmine et al. BMC Research Notes 2012, 5:117. This article repeatedly refers to our previous work and concludes that methylation data obtained from ligated FFPE extracted DNA should be used with great caution. In this Discussion we review the data analysis performed in Jasmine et al's paper and suggest limitations which subsequently lead the authors to draw what we believe are incorrect conclusions. Moreover, we continue to analyse genome-wide methylation data from DNA extracted from FFPE tissue successfully on both the HumMeth27 and 450K arrays.
    Digitale ISSN: 1756-0500
    Thema: Biologie , Medizin
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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