11 research outputs found
The IPBES Conceptual Framework - connecting nature and people
The first public product of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is its Conceptual Framework. This conceptual and analytical tool, presented here in detail, will underpin all IPBES functions and provide structure and comparability to the syntheses that IPBES will produce at different spatial scales, on different themes, and in different regions. Salient innovative aspects of the IPBES Conceptual Framework are its transparent and participatory construction process and its explicit consideration of diverse scientific disciplines, stakeholders, and knowledge systems, including indigenous and local knowledge. Because the focus on co-construction of integrative knowledge is shared by an increasing number of initiatives worldwide, this framework should be useful beyond IPBES, for the wider research and knowledge-policy communities working on the links between nature and people, such as natural, social and engineering scientists, policy-makers at different levels, and decision-makers in different sectors of society
Placental phenotypes associated with abnormal genomic imprinting on distal mouse chromosome 7
Imprinted genes are expressed either from the maternal or paternal allele during development and tend to be found in clusters throughout the mammalian genome, suggesting they may be regulated by long-range mechanisms. Many of them have important roles in placental development. The Beckwith-Wiedemann Syndrome (BWS) region on human chromosome 11p15.5 contains two imprinted subdomains each regulated by their own differentially methylated regions, known as imprinting centres (IC1 and IC2). These two imprinted subdomains are separated by an evolutionarily conserved region of about 300 kilobases. Distal mouse chromosome 7 (MMU7) shares syntenic homology with the human BWS region. Since the mechanisms by which imprinting occurs are unclear, we sought to characterize this region further using two mouse lines carrying deletions within the BWS imprinted region. The first mouse line, called DelTel7/IC2KO, allows us to dissect out the role of imprinting centre 2 in the silencing of imprinted genes. We demonstrate that all of the distal MMU7 imprinted genes implicated in placental function are silenced by IC2 and the noncoding RNA Kcnq1ot1. The second mouse line, called Delâ·AI, allows us to determine whether placental imprinting is perturbed when the region between IC1 and IC2 is deleted. We found that maternal inheritance of Delâ·AI leads to partial loss of the gene Ascl2, and we show that this affects all three layers of the mature mouse placenta. We found that paternal inheritance of Delâ·AI leads to partial loss of Ascl2 imprinting. Detailed investigation of the underlying mechanisms of imprinting and phenotypes in these mouse lines provides us with new fundamental insights into placental biology and the regulation of gene expression by imprinting centres on distal mouse chromosome 7.Medicine, Faculty ofMedical Genetics, Department ofGraduat
Rescue of placental phenotype in a mechanistic model of Beckwith-Wiedemann syndrome
Background:
Several imprinted genes have been implicated in the process of placentation. The distal region of mouse chromosome 7 (Chr 7) contains at least ten imprinted genes, several of which are expressed from the maternal homologue in the placenta. The corresponding paternal alleles of these genes are silenced in cis by an incompletely understood mechanism involving the formation of a repressive nuclear compartment mediated by the long non-coding RNA Kcnq1ot1 initiated from imprinting centre 2 (IC2). However, it is unknown whether some maternally expressed genes are silenced on the paternal homologue via a Kcnq1ot1-independent mechanism. We have previously reported that maternal inheritance of a large truncation of Chr7 encompassing the entire IC2-regulated domain (DelTel7 allele) leads to embryonic lethality at mid-gestation accompanied by severe placental abnormalities. Kcnq1ot1 expression can be abolished on the paternal chromosome by deleting IC2 (IC2KO allele). When the IC2KO mutation is paternally inherited, epigenetic silencing is lost in the region and the DelTel7 lethality is rescued in compound heterozygotes, leading to viable DelTel7/IC2KO mice.
Results:
Considering the important functions of several IC2-regulated genes in placentation, we set out to determine whether these DelTel7/IC2KO rescued conceptuses develop normal placentae. We report no abnormalities with respect to the architecture and vasculature of the DelTel7/IC2KO rescued placentae. Imprinted expression of several of the IC2-regulated genes critical to placentation is also faithfully recapitulated in DelTel7/IC2KO placentae.
Conclusion:
Taken together, our results demonstrate that all the distal chromosome 7 imprinted genes implicated in placental function are silenced by IC2 and Kcnq1ot1 on the paternal allele. Furthermore, our results demonstrate that the methylated maternal IC2 is not required for the regulation of nearby genes. The results show the potential for fully rescuing trans placental abnormalities that are caused by imprinting defects.Medical Genetics, Department ofMedicine, Faculty ofOther UBCNon UBCReviewedFacult
Do catheter washouts extend patency time in long-term indwelling urethral catheters? A randomized controlled trial of acidic washout solution, normal saline washout, or standard care.
AB PURPOSE Blockage of long-term indwelling catheters with mineral deposit is an ongoing management issue, but evidence on optimal management is lacking. Our purpose was to examine whether catheter washouts prevent or reduce catheter blockage. DESIGN A multisite randomized controlled trial. SUBJECTS AND SETTING Adults with long-term indwelling catheters that required changing every 3 weeks or less, living in the community, and requiring supportive or continuing care were recruited. Participants were randomly assigned to 1 of 3 groups: control (usual care, no washout), saline washout, or commercially available acidic washout solution (Contisol Maelor Pharmaceuticals Ltd, Wrexham, UK). METHODS At baseline visit, the catheter was changed and participants were followed weekly for 8 weeks, with checks for catheter patency and urine pH. Participants randomized to saline or commercial solution had a weekly washout with the appropriate solution. Endpoints were 8 weeks (completion data), 3 or more catheter changes in the 8-week period, or symptomatic urinary tract infection (UTI) requiring antibiotics. The study hypothesis was that catheter life would be extended by 25% in the commercial solution group. It was not possible to blind participants or research nurses to washout versus no intervention, but participants in the saline and washout solution groups were blinded to solution type. RESULTS One hundred twelve potential participants were screened; 73 were enrolled, randomized, and included in the final analysis. Of these, 53 completed the full 8 weeks of data collection; 16 terminated early because of 3 catheter changes or self-reported 'UTI'. Other reasons for termination were hematuria, latex sensitivity, deceased/severe illness, or personal choice. Analysis of variance was used to analyze mean differences on demographic variables and mean number of weeks in study. Kaplan-Meier survival curve analysis showed no statistical difference between the groups in time to first catheter change. CONCLUSION At this time, the evidence is insufficient to state whether catheter washout with saline or Contisol is more effective than usual care with no washout in preventing blocking. No increased risk of UTI was associated with washout regime
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Discrimination And Calibration Of The Vacs Index 2.0 For Predicting Mortality Among People With Hiv In North America
BackgroundThe updated Veterans Aging Cohort Study (VACS) Index 2.0 combines general and human immunodeficiency virus (HIV)-specific biomarkers to generate a continuous score that accurately discriminates risk of mortality in diverse cohorts of persons with HIV (PWH), but a score alone is difficult to interpret. Using data from the North American AIDS Cohort Collaboration (NA-ACCORD), we translate VACS Index 2.0 scores into validated probability estimates of mortality.MethodsBecause complete mortality ascertainment is essential for accurate calibration, we restricted analyses to cohorts with mortality from the National Death Index or equivalent sources. VACS Index 2.0 components were ascertained from October 1999 to April 2018. Mortality was observed up to March 2019. Calibration curves compared predicted (estimated by fitting a gamma model to the score) to observed mortality overall and within subgroups: cohort (VACS/NA-ACCORD subset), sex, age <50 or â„50 years, race/ethnicity, HIV-1 RNA â€500 or >500 copies/mL, CD4 count <350 or â„350 cells/”L, and years 1999-2009 or 2010-2018. Because mortality rates have decreased over time, the final model was limited to 2010-2018.ResultsAmong 37230 PWH in VACS and 8061 PWH in the NA-ACCORD subset, median age was 53 and 44 years; 3% and 19% were women; and 48% and 39% were black. Discrimination in NA-ACCORD (C-statistic = 0.842 [95% confidence interval {CI}, .830-.854]) was better than in VACS (C-statistic = 0.813 [95% CI, .809-.817]). Predicted and observed mortality largely overlapped in VACS and the NA-ACCORD subset, overall and within subgroups.ConclusionsBased on this validation, VACS Index 2.0 can reliably estimate probability of all-cause mortality, at various follow-up times, among PWH in North America