200 research outputs found
A multi-parent recombinant inbred line population of C. elegans allows identification of novel QTLs for complex life history traits
Background
The nematode Caenorhabditis elegans has been extensively used to explore the relationships between complex traits, genotypes, and environments. Complex traits can vary across different genotypes of a species, and the genetic regulators of trait variation can be mapped on the genome using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) derived from genetically and phenotypically divergent parents. Most RILs have been derived from crossing two parents from globally distant locations. However, the genetic diversity between local C. elegans populations can be as diverse as between global populations and could thus provide means of identifying genetic variation associated with complex traits relevant on a broader scale.
Results
To investigate the effect of local genetic variation on heritable traits, we developed a new RIL population derived from 4 parental wild isolates collected from 2 closely located sites in France: Orsay and Santeuil. We crossed these 4 genetically diverse parental isolates to generate a population of 200 multi-parental RILs and used RNA-seq to obtain sequence polymorphisms identifying almost 9000 SNPs variable between the 4 genotypes with an average spacing of 11 kb, doubling the mapping resolution relative to currently available RIL panels for many loci. The SNPs were used to construct a genetic map to facilitate QTL analysis. We measured life history traits such as lifespan, stress resistance, developmental speed, and population growth in different environments, and found substantial variation for most traits. We detected multiple QTLs for most traits, including novel QTLs not found in previous QTL analysis, including those for lifespan and pathogen responses. This shows that recombining genetic variation across C. elegans populations that are in geographical close proximity provides ample variation for QTL mapping.
Conclusion
Taken together, we show that using more parents than the classical two parental genotypes to construct a RIL population facilitates the detection of QTLs and that the use of wild isolates facilitates the detection of QTLs. The use of multi-parent RIL populations can further enhance our understanding of local adaptation and life history trade-offs
Multi-element analysis of biological material by RNAA using HPLC with on-line yield determination
Sexuality and Body Image After Uterine Artery Embolization and Hysterectomy in the Treatment of Uterine Fibroids: A Randomized Comparison
In this paper the effect of uterine artery embolization (UAE) on sexual functioning and body image is investigated in a randomized comparison to hysterectomy for symptomatic uterine fibroids. The EMbolization versus hysterectoMY (EMMY) trial is a randomized controlled study, conducted at 28 Dutch hospitals. Patients were allocated hysterectomy (n = 89) or UAE (n = 88). Two validated questionnaires (the Sexual Activity Questionnaire [SAQ] and the Body Image Scale [BIS]) were completed by all patients at baseline, 6 weeks, and 6, 12, 18, and 24 months after treatment. Repeated measurements on SAQ scores revealed no differences between the groups. There was a trend toward improved sexual function in both groups at 2 years, although this failed to reach statistical significance except for the dimensions discomfort and habit in the UAE arm. Overall quality of sexual life deteriorated in a minority of cases at all time points, with no significant differences between the groups (at 24 months: UAE, 29.3%, versus hysterectomy, 23.5%; p = 0.32). At 24 months the BIS score had improved in both groups compared to baseline, but the change was only significant in the UAE group (p = 0.009). In conclusion, at 24 months no differences in sexuality and body image were observed between the UAE and the hysterectomy group. On average, both after UAE and hysterectomy sexual functioning and body image scores improved, but significantly so only after UAE
Subcellular heterogeneity of ryanodine receptor properties in ventricular myocytes with low T-tubule density
Rationale:
In ventricular myocytes of large mammals, not all ryanodine receptor (RyR) clusters are associated with T-tubules (TTs); this fraction increases with cellular remodeling after myocardial infarction (MI).
Objective:
To characterize RyR functional properties in relation to TT proximity, at baseline and after MI.
Methods:
Myocytes were isolated from left ventricle of healthy pigs (CTRL) or from the area adjacent to a myocardial infarction (MI). Ca2+ transients were measured under whole-cell voltage clamp during confocal linescan imaging (fluo-3) and segmented according to proximity of TTs (sites of early Ca2+ release, F>F50 within 20 ms) or their absence (delayed areas). Spontaneous Ca2+ release events during diastole, Ca2+ sparks, reflecting RyR activity and properties, were subsequently assigned to either category.
Results:
In CTRL, spark frequency was higher in proximity of TTs, but spark duration was significantly shorter. Block of Na+/Ca2+ exchanger (NCX) prolonged spark duration selectively near TTs, while block of Ca2+ influx via Ca2+ channels did not affect sparks properties. In MI, total spark mass was increased in line with higher SR Ca2+ content. Extremely long sparks (>47.6 ms) occurred more frequently. The fraction of near-TT sparks was reduced; frequency increased mainly in delayed sites. Increased duration was seen in near-TT sparks only; Ca2+ removal by NCX at the membrane was significantly lower in MI.
Conclusion:
TT proximity modulates RyR cluster properties resulting in intracellular heterogeneity of diastolic spark activity. Remodeling in the area adjacent to MI differentially affects these RyR subpopulations. Reduction of the number of sparks near TTs and reduced local NCX removal limit cellular Ca2+ loss and raise SR Ca2+ content, but may promote Ca2+ waves
The Efficacy, Safety, and Immunogenicity of Switching Between Reference Biopharmaceuticals and Biosimilars: A Systematic Review
To date, no consensus exists among stakeholders about the safety of switching between reference biological products (RPs) and biosimilars, which may have been curbing the implementation of biosimilars in clinical practice. This study synthesizes the available data on switching and assesses whether switching patients from a RP to its biosimilar or vice versa affects efficacy, safety, or immunogenicity outcomes. A total of 178 studies, in which switch outcomes from a RP to a biosimilar were reported, was identified. Data were derived from both randomized controlled trials and real-world evidence. Despite the limitations stemming from a lack of a robust design for most of the studies, the available switching data do not indicate that switching from a RP to a biosimilar is associated with any major efficacy, safety, or immunogenicity issues. Some open-label and observational studies reported increased discontinuation rates after switching, which were mainly attributed to nocebo effects. Involvement of the prescriber in any decision to switch should remain and attention should be paid to the mitigation of a potential nocebo effect
Effects of a 10-week multimodal exercise program on physical and cognitive function of nursing home residents: a psychomotor intervention pilot study
Second primary neoplasms among 53 159 haematolymphoproliferative malignancy patients in Sweden, 1958–1996: a search for common mechanisms
The Swedish Family-Cancer Database was used to analyse site-specific risk of second primary malignancies following 53 159 haematolymphoproliferative disorders (HLPD) diagnosed between 1958 and 1996. Standardized incidence ratio (SIR) of a second malignancy was calculated as the ratio of observed to expected numbers of second malignancies by applying site-, sex-, age-, period-, residence- and occupation-specific rates in the corresponding population in the Database to the appropriate person-years at risk. Among 18 960 patients with non-Hodgkin's lymphoma (NHL), there was over a 3-fold significant increase in cancer of the tongue, small intestine, nose, kidney and nervous system, squamous cell carcinoma (SCC) of the skin, NHL, Hodgkin's disease (HD) and lymphoid and myeloid leukaemia. Among 5353 patients with HD, there was over a 4-fold significant increase in cancer of the salivary glands, nasopharynx and thyroid, NHL and myeloid leukaemia, and over a 1.6-fold increase in cancer of the stomach, colon, lung, breast, skin (melanoma and SCC), nervous system and soft tissues and lymphoid leukaemia. Among 28 846 patients with myeloma and leukaemia, there was a significant increase in cancer of the skin, nervous system and non-thyroid endocrine glands and all HLPD except for myeloma. Our findings showed some clustering between first and second primaries among Epstein–Barr virus-, ultraviolet radiation- and immunosuppression-related cancers. © 2001 Cancer Research Campaignhttp://www.bjcancer.co
Chondroprotection by urocortin involves blockade of the mechanosensitive ion channel Piezo1
Osteoarthritis (OA) is characterised by progressive destruction of articular cartilage and chondrocyte cell death. Here, we show the expression of the endogenous peptide urocortin1 (Ucn1) and two receptor subtypes, CRF-R1 and CRF-R2, in primary human articular chondrocytes (AC) and demonstrate its role as an autocrine/paracrine pro-survival factor. This effect could only be removed using the CRF-R1 selective antagonist CP-154526, suggesting Ucn1 acts through CRF-R1 when promoting chondrocyte survival. This cell death was characterised by an increase in p53 expression, and cleavage of caspase 9 and 3. Antagonism of CRF-R1 with CP-154526 caused an accumulation of intracellular calcium (Ca2+) over time and cell death. These effects could be prevented with the non-selective cation channel blocker Gadolinium (Gd3+). Therefore, opening of a non-selective cation channel causes cell death and Ucn1 maintains this channel in a closed conformation. This channel was identified to be the mechanosensitive channel Piezo1. We go on to determine that this channel inhibition by Ucn1 is mediated initially by an increase in cyclic adenosine monophosphate (cAMP) and a subsequent inactivation of phospholipase A2 (PLA2), whose metabolites are known to modulate ion channels. Knowledge of these novel pathways may present opportunities for interventions that could abrogate the progression of OA
The ethics of psychopharmacological research in legal minors
Research in psychopharmacology for children and adolescents is fraught with ethical problems and tensions. This has practical consequences as it leads to a paucity of the research that is essential to support the treatment of this vulnerable group. In this article, we will discuss some of the ethical issues which are relevant to such research, and explore their implications for both research and standard care. We suggest that finding a way forward requires a willingness to acknowledge and discuss the inherent conflicts between the ethical principles involved. Furthermore, in order to facilitate more, ethically sound psychopharmacology research in children and adolescents, we suggest more ethical analysis, empirical ethics research and ethics input built into psychopharmacological research design
Health disparities by occupation, modified by education: a cross-sectional population study
<p>Abstract</p> <p>Background</p> <p>Socio-economic disparities in health status are frequently reported in research. By comparison with education and income, occupational status has been less extensively studied in relation to health status or the occurrence of specific chronic diseases. The aim of this study was to investigate health disparities in the working population based on occupational position and how they were modified by education.</p> <p>Methods</p> <p>Our data were derived from the National Survey of General Practice that comprised 104 practices in the Netherlands. 136,189 working people aged 25–64 participated in the study. Occupational position was assessed by the International Socio-Economic Index of occupational position (ISEI). Health outcomes were self-perceived health status and physician-diagnosed diseases. Odds ratios were estimated using multivariate logistic regression analysis.</p> <p>Results</p> <p>The lowest occupational position was observed to be associated with poor health in men (OR = 1.6, 95% CI 1,5 to 1.7) and women (OR = 1.3, 95% CI 1.2 to 1.4). The risk of poor health gradually decreased in relation to higher occupational positions. People with the lowest occupational positions were more likely to suffer from depression, diabetes, ischaemic heart disease, arthritis, muscle pain, neck and back pain and tension headache, in comparison to people with the highest occupational position (OR 1.2 to 1.6). A lower educational level induced an additional risk of poor health and disease. We found that gender modified the effects on poor health when both occupational position and education were combined in the analysis.</p> <p>Conclusion</p> <p>A low occupational position was consistently associated working people with poor health and physician-diagnosed morbidity. However a low educational level was not. Occupational position and education had a combined effect on self-perceived health, which supports the recent call to improve the conceptual framework of health disparities.</p
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