2,191 research outputs found

    Social impacts of IPM-FFS on urban and peri-urban vegetable producers in Cotonou, Benin

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    Shifting from scientist-led top-down approaches in agricultural development to participatory approaches putting farmers and their knowledge in the center requires scientists and farmers to play new roles, changing social relationships between them, and among farmers themselves. Using mainly qualitative data and analysis, this paper reports social impacts (social relations, social empowerment and sharing of IPM information, and sustainability and institutionalization of IPM) for vegetable producers in an integrated pest management (IPM) project using farmer field schools (FFS) in Cotonou. Forty-three vegetable producers were chosen for semi-structured interviews. The project led to social empowerment of the vegetable producers and initiated a process of creation and sharing of IPM knowledge and building of social relations within and between the vegetable gardens. The participants realized they were sources of information for each other, and IPM knowledge was shared without the benefit or restriction of social networks. However, this study revealed several factors hindering the development of improved social relations among the vegetable producers and between these and the scientists and steering committee members, which in turn may result in lack of continuation and institutionalization of IPM activities. To overcome these obstacles, this research suggests that similar IPM-FFS projects encourage (1) a transparent selection process, (2) improvement of the Trainer of Trainers’ facilitation skills for better quality FFSs and improved sharing of complex information like agro-ecosystem analysis and  beneficial insects, (3) building trust and confidence between the  participants and scientists, (4) giving the ToT participants, community organizers and farmer organizations ownership of the project by giving them responsibility for creating post project plans to spread and institutionalize IPM of IPM-FFS activities and (5) facilitating the participants during and after the project in improving social relations and accountability. The results also draw lessons on how scientists and vegetable producers have or should have changed their roles to sustain and institutionalize IPM, such as the scientists and project leaders need to focus even more on their interactions with vegetable producers, enhancing their role as facilitators in initiating equitable processes of sustaining and institutionalizing IPM in the vegetable gardens.Key words: IPM-FFS, Empowerment, Relations, Information sharin

    Genome-wide DNA methylation analysis for diabetic nephropathy in type 1 diabetes mellitus

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    BACKGROUND: Diabetic nephropathy is a serious complication of diabetes mellitus and is associated with considerable morbidity and high mortality. There is increasing evidence to suggest that dysregulation of the epigenome is involved in diabetic nephropathy. We assessed whether epigenetic modification of DNA methylation is associated with diabetic nephropathy in a case-control study of 192 Irish patients with type 1 diabetes mellitus (T1D). Cases had T1D and nephropathy whereas controls had T1D but no evidence of renal disease. METHODS: We performed DNA methylation profiling in bisulphite converted DNA from cases and controls using the recently developed Illumina Infinium(R) HumanMethylation27 BeadChip, that enables the direct investigation of 27,578 individual cytosines at CpG loci throughout the genome, which are focused on the promoter regions of 14,495 genes. RESULTS: Singular Value Decomposition (SVD) analysis indicated that significant components of DNA methylation variation correlated with patient age, time to onset of diabetic nephropathy, and sex. Adjusting for confounding factors using multivariate Cox-regression analyses, and with a false discovery rate (FDR) of 0.05, we observed 19 CpG sites that demonstrated correlations with time to development of diabetic nephropathy. Of note, this included one CpG site located 18 bp upstream of the transcription start site of UNC13B, a gene in which the first intronic SNP rs13293564 has recently been reported to be associated with diabetic nephropathy. CONCLUSION: This high throughput platform was able to successfully interrogate the methylation state of individual cytosines and identified 19 prospective CpG sites associated with risk of diabetic nephropathy. These differences in DNA methylation are worthy of further follow-up in replication studies using larger cohorts of diabetic patients with and without nephropathy

    Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.

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    PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P < 0.001), age, bisphosphonate use, and rodding (P < 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves

    Is heart failure misdiagnosed in hospitalized patients with preserved ejection fraction? From the European Society of Cardiology - Heart Failure Association EURObservational Research Programme Heart Failure Long-Term Registry.

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    AIMS: In hospitalized patients with a clinical diagnosis of acute heart failure (HF) with preserved ejection fraction (HFpEF), the aims of this study were (i) to assess the proportion meeting the 2016 European Society of Cardiology (ESC) HFpEF criteria and (ii) to compare patients with restrictive/pseudonormal mitral inflow pattern (MIP) vs. patients with MIP other than restrictive/pseudonormal. METHODS AND RESULTS: We included hospitalized participants of the ESC-Heart Failure Association (HFA) EURObservational Research Programme (EORP) HF Long-Term Registry who had echocardiogram with ejection fraction (EF) ≥ 50% during index hospitalization. As no data on e', E/e' and left ventricular (LV) mass index were gathered in the registry, the 2016 ESC HFpEF definition was modified as follows: elevated B-type natriuretic peptide (BNP) (≥100 pg/mL for acute HF) and/or N-terminal pro-BNP (≥300 pg/mL) and at least one of the echocardiographic criteria: (i) presence of LV hypertrophy (yes/no), (ii) left atrial volume index (LAVI) of >34 mL/m2 ), or (iii) restrictive/pseudonormal MIP. Next, all patients were divided into four groups: (i) patients with restrictive/pseudonormal MIP on echocardiography [i.e. with presumably elevated left atrial (LA) pressure], (ii) patients with MIP other than restrictive/pseudonormal (i.e. with presumably normal LA pressure), (iii) atrial fibrillation (AF) group, and (iv) 'grey area' (no consistent description of MIP despite no report of AF). Of 6365 hospitalized patients, 1848 (29%) had EF ≥ 50%. Natriuretic peptides were assessed in 28%, LV hypertrophy in 92%, LAVI in 13%, and MIP in 67%. The 2016 ESC HFpEF criteria could be assessed in 27% of the 1848 patients and, if assessed, were met in 52%. Of the 1848 patients, 19% had restrictive/pseudonormal MIP, 43% had MIP other than restrictive/pseudonormal, 18% had AF and 20% were grey area. There were no differences in long-term all-cause or cardiovascular mortality, or all-cause hospitalizations or HF rehospitalizations between the four groups. Despite fewer non-cardiac comorbidities reported at baseline, patients with MIP other than restrictive/pseudonormal (i.e. with presumably normal LA pressure) had more non-cardiovascular (14.0 vs. 6.7 per 100 patient-years, P < 0.001) and cardiovascular non-HF (13.2 vs. 8.0 per 100 patient-years, P = 0.016) hospitalizations in long-term follow-up than patients with restrictive/pseudonormal MIP. CONCLUSIONS: Acute HFpEF diagnosis could be assessed (based on the 2016 ESC criteria) in only a quarter of patients and confirmed in half of these. When assessed, only one in three patients had restrictive/pseudonormal MIP suggestive of elevated LA pressure. Patients with MIP other than restrictive/pseudonormal (suggestive of normal LA pressure) could have been misdiagnosed with acute HFpEF or had echocardiography performed after normalization of LA pressure. They were more often hospitalized for non-HF reasons during follow-up. Symptoms suggestive of acute HFpEF may in some patients represent non-HF comorbidities

    Amino Acid Similarity Accounts for T Cell Cross-Reactivity and for “Holes” in the T Cell Repertoire

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    Background: Cytotoxic T cell (CTL) cross-reactivity is believed to play a pivotal role in generating immune responses but the extent and mechanisms of CTL cross-reactivity remain largely unknown. Several studies suggest that CTL clones can recognize highly diverse peptides, some sharing no obvious sequence identity. The emerging realization in the field is that T cell receptors (TcR) recognize multiple distinct ligands. Principal Findings: First, we analyzed peptide scans of the HIV epitope SLFNTVATL (SFL9) and found that TCR specificity is position dependent and that biochemically similar amino acid substitutions do not drastically affect recognition. Inspired by this, we developed a general model of TCR peptide recognition using amino acid similarity matrices and found that such a model was able to predict the cross-reactivity of a diverse set of CTL epitopes. With this model, we were able to demonstrate that seemingly distinct T cell epitopes, i.e., ones with low sequence identity, are in fact more biochemically similar than expected. Additionally, an analysis of HIV immunogenicity data with our model showed that CTLs have the tendency to respond mostly to peptides that do not resemble self-antigens. Conclusions: T cell cross-reactivity can thus, to an extent greater than earlier appreciated, be explained by amino acid similarity. The results presented in this paper will help resolving some of the long-lasting discussions in the field of T cel

    Analyzing the Number of Common Integration Sites of Viral Vectors – New Methods and Computer Programs

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    Vectors based on γ-retroviruses or lentiviruses have been shown to stably express therapeutical transgenes and effectively cure different hematological diseases. Molecular follow up of the insertional repertoire of gene corrected cells in patients and preclinical animal models revealed different integration preferences in the host genome including clusters of integrations in small genomic areas (CIS; common integrations sites). In the majority, these CIS were found in or near genes, with the potential to influence the clonal fate of the affected cell. To determine whether the observed degree of clustering is statistically compatible with an assumed standard model of spatial distribution of integrants, we have developed various methods and computer programs for γ-retroviral and lentiviral integration site distribution. In particular, we have devised and implemented mathematical and statistical approaches for comparing two experimental samples with different numbers of integration sites with respect to the propensity to form CIS as well as for the analysis of coincidences of integration sites obtained from different blood compartments. The programs and statistical tools described here are available as workspaces in R code and allow the fast detection of excessive clustering of integration sites from any retrovirally transduced sample and thus contribute to the assessment of potential treatment-related risks in preclinical and clinical retroviral gene therapy studies

    Reproducibility of exhaled nitric oxide in smokers and non-smokers: relevance for longitudinal studies

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    <p>Abstract</p> <p>Background</p> <p>Currently, there is much interest in measuring fractional exhaled nitric oxide (<b>FE<sub>NO</sub></b>) in populations. We evaluated the reproducibility of <b>FE<sub>NO </sub></b>in healthy subjects and determined the number of subjects necessary to carry out a longitudinal survey of <b>FE<sub>NO </sub></b>in a population containing smokers and non-smokers, based on the assessed reproducibility.</p> <p>Methods</p> <p>The reproducibility of <b>FE<sub>NO </sub></b>was examined in 18 healthy smokers and 21 non-smokers. <b>FE<sub>NO </sub></b>was assessed once at 9 AM on five consecutive days; in the last day this measurement was repeated at 2 PM. Respiratory symptoms and medical history were assessed by questionnaire. The within- and between-session repeatability of <b>FE<sub>NO </sub></b>and log-transformed <b>FE<sub>NO </sub></b>was described. The power of a longitudinal study based on a relative increase in <b>FE<sub>NO </sub></b>was estimated using a bilateral t-test of the log-transformed <b>FE<sub>NO </sub></b>using the between-session variance of the assay.</p> <p>Results</p> <p><b>FE<sub>NO </sub></b>measurements were highly reproducible throughout the study. <b>FE<sub>NO </sub></b>was significantly higher in males than females regardless of smoking status. <b>FE<sub>NO </sub></b>was positively associated with height (p < 0.001), gender (p < 0.034), smoking (p < 0.0001) and percent FEV<sub>1</sub>/FVC (p < 0.001) but not with age (p = 0.987). The between-session standard deviation was roughly constant on the log scale. Assuming the between-session standard deviation is equal to its longitudinal equivalent, either 111 or 29 subjects would be necessary to achieve an 80% power in detecting a 3% or a 10% increase in <b>FE<sub>NO </sub></b>respectively.</p> <p>Conclusion</p> <p>The good reproducibility of <b>FE<sub>NO </sub></b>is not influenced by gender or smoking habits. In a well controlled, longitudinal study it should allow detecting even small increases in <b>FE<sub>NO </sub></b>with a reasonable population size.</p
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