Protein Binding of Lopinavir and Ritonavir During 4 Phases of Pregnancy: Implications for Treatment Guidelines

To investigate the intraindividual pharmacokinetics of total (protein bound + unbound) and unbound lopinavir/ritonavir (LPV/RTV) and to assess whether the pediatric formulation (100mg/25mg) can overcome any pregnancy-associated changes

Study protocol for the translating research in elder care (TREC): building context – an organizational monitoring program in long-term care project (project one)

<p>Abstract</p> <p>Background</p> <p>While there is a growing awareness of the importance of organizational context (or the work environment/setting) to successful knowledge translation, and successful knowledge translation to better patient, provider (staff), and system outcomes, little empirical evidence supports these assumptions. Further, little is known about the factors that enhance knowledge translation and better outcomes in residential long-term care facilities, where care has been shown to be suboptimal. The project described in this protocol is one of the two main projects of the larger five-year Translating Research in Elder Care (TREC) program.</p> <p>Aims</p> <p>The purpose of this project is to establish the magnitude of the effect of organizational context on knowledge translation, and subsequently on resident, staff (unregulated, regulated, and managerial) and system outcomes in long-term care facilities in the three Canadian Prairie Provinces (Alberta, Saskatchewan, Manitoba).</p> <p>Methods/Design</p> <p>This study protocol describes the details of a multi-level – including provinces, regions, facilities, units within facilities, and individuals who receive care (residents) or work (staff) in facilities – and longitudinal (five-year) research project. A stratified random sample of 36 residential long-term care facilities (30 urban and 6 rural) from the Canadian Prairie Provinces will comprise the sample. Caregivers and care managers within these facilities will be asked to complete the TREC survey – a suite of survey instruments designed to assess organizational context and related factors hypothesized to be important to successful knowledge translation and to achieving better resident, staff, and system outcomes. Facility and unit level data will be collected using standardized data collection forms, and resident outcomes using the Resident Assessment Instrument-Minimum Data Set version 2.0 instrument. A variety of analytic techniques will be employed including descriptive analyses, psychometric analyses, multi-level modeling, and mixed-method analyses.</p> <p>Discussion</p> <p>Three key challenging areas associated with conducting this project are discussed: sampling, participant recruitment, and sample retention; survey administration (with unregulated caregivers); and the provision of a stable set of study definitions to guide the project.</p

Identifying the domains of context important to implementation science: a study protocol

Background There is growing recognition that “context” can and does modify the effects of implementation interventions aimed at increasing healthcare professionals’ use of research evidence in clinical practice. However, conceptual clarity about what exactly comprises “context” is lacking. The purpose of this research program is to develop, refine, and validate a framework that identifies the key domains of context (and their features) that can facilitate or hinder (1) healthcare professionals’ use of evidence in clinical practice and (2) the effectiveness of implementation interventions. Methods/design A multi-phased investigation of context using mixed methods will be conducted. The first phase is a concept analysis of context using the Walker and Avant method to distinguish between the defining and irrelevant attributes of context. This phase will result in a preliminary framework for context that identifies its important domains and their features according to the published literature. The second phase is a secondary analysis of qualitative data from 13 studies of interviews with 312 healthcare professionals on the perceived barriers and enablers to their application of research evidence in clinical practice. These data will be analyzed inductively using constant comparative analysis. For the third phase, we will conduct semi-structured interviews with key health system stakeholders and change agents to elicit their knowledge and beliefs about the contextual features that influence the effectiveness of implementation interventions and healthcare professionals’ use of evidence in clinical practice. Results from all three phases will be synthesized using a triangulation protocol to refine the context framework drawn from the concept analysis. The framework will then be assessed for content validity using an iterative Delphi approach with international experts (researchers and health system stakeholders/change agents). Discussion This research program will result in a framework that identifies the domains of context and their features that can facilitate or hinder: (1) healthcare professionals’ use of evidence in clinical practice and (2) the effectiveness of implementation interventions. The framework will increase the conceptual clarity of the term “context” for advancing implementation science, improving healthcare professionals’ use of evidence in clinical practice, and providing greater understanding of what interventions are likely to be effective in which contexts

Significant Improvements in the Practice Patterns of Adult Related Donor Care in US Transplantation Centers

Recent investigations have found a higher incidence of adverse events associated with hematopoietic cell donation in related donors (RDs) who have morbidities that if present in an unrelated donor (UD) would preclude donation. In the UD setting, regulatory standards ensure independent assessment of donors, one of several crucial measures to safeguard donor health and safety. A survey conducted by the Center for International Blood and Marrow Transplant Research (CIBMTR) Donor Health and Safety Working Committee in 2007 reported a potential conflict of interest in >70% US centers, where physicians had simultaneous responsibility for RDs and their recipients. Consequently, several international organizations have endeavored to improve practice through regulations and consensus recommendations. We hypothesized that the changes in the 2012 FACT-JACIE Standards, resulting from the CIBMTR study, will have significantly impacted practice. Accordingly, a follow-up survey of US transplant centers was conducted to assess practice changes since 2007, and investigate additional areas where RD care was predicted to differ from UD care. 73 centers (53%), performing 79% of US RD transplants responded. Significant improvements were observed since the earlier survey; 62% centers now ensure separation of RD and recipient care (P<0.0001). However, this study identifies several areas where RD management does not meet international donor care standards. Particular concerns include counseling and assessment of donors before HLA typing, with 61% centers first disclosing donor HLA results to an individual other than the donor, the use of unlicensed mobilization agents, and the absence of long-term donor follow-up. Recommendations for improvement are described

Height, selected genetic markers and prostate cancer risk:Results from the PRACTICAL consortium

Background: Evidence on height and prostate cancer risk is mixed, however, recent studies with large data sets support a possible role for its association with the risk of aggressive prostate cancer. Methods: We analysed data from the PRACTICAL consortium consisting of 6207 prostate cancer cases and 6016 controls and a subset of high grade cases (2480 cases). We explored height, polymorphisms in genes related to growth processes as main effects and their possible interactions. Results: The results suggest that height is associated with high-grade prostate cancer risk. Men with height 4180cm are at a 22% increased risk as compared to men with height o173cm (OR 1.22, 95% CI 1.01–1.48). Genetic variants in the growth pathway gene showed an association with prostate cancer risk. The aggregate scores of the selected variants identified a significantly increased risk of overall prostate cancer and high-grade prostate cancer by 13% and 15%, respectively, in the highest score group as compared to lowest score group. Conclusions: There was no evidence of gene-environment interaction between height and the selected candidate SNPs. Our findings suggest a role of height in high-grade prostate cancer. The effect of genetic variants in the genes related to growth is seen in all cases and high-grade prostate cancer. There is no interaction between these two exposures.</p

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

Atlas of prostate cancer heritability in European and African-American men pinpoints tissue-specific regulation

Although genome-wide association studies have identified over 100 risk loci that explain ∼33% of familial risk for prostate cancer (PrCa), their functional effects on risk remain largely unknown. Here we use genotype data from 59,089 men of European and African American ancestries combined with cell-type-specific epigenetic data to build a genomic atlas of single-nucleotide polymorphism (SNP) heritability in PrCa. We find significant differences in heritability between variants in prostate-relevant epigenetic marks defined in normal versus tumour tissue as well as between tissue and cell lines. The majority of SNP heritability lies in regions marked by H3k27 acetylation in prostate adenoc7arcinoma cell line (LNCaP) or by DNaseI hypersensitive sites in cancer cell lines. We find a high degree of similarity between European and African American ancestries suggesting a similar genetic architecture from common variation underlying PrCa risk. Our findings showcase the power of integrating functional annotation with genetic data to understand the genetic basis of PrCa

Risk of preterm delivery and growth restriction in twins discordant for structural anomalies

OBJECTIVE: To determine whether twin gestations with an anomalous fetus are at increased risk of preterm delivery (PTD) or intrauterine growth restriction (IUGR) compared to twins with two normal fetuses. STUDY DESIGN: Retrospective cohort of twins undergoing ultrasound 15–22 weeks gestation. Groups were defined by the presence of one twin with a major anomaly (discordant) or by twins with no major anomalies (normal). The primary outcomes were PTD (<37 weeks) and IUGR (<10(th) percentile). RESULTS: Of 1,977 twin pregnancies, 66 had a twin with a major anomaly. Preterm delivery occurred in 42 (63.6%) discordant twins, compared to 1271 (66.5%) normal twins (risk ratio (RR) 1.0, 95% confidence interval (CI) 0.8–1.2). IUGR was diagnosed in 15 (22.7%) normal co-twins, compared to 406 (21.3%) presenting twins in normal twins (RR 1.1, 95% CI 0.7–1.7). CONCLUSION: Twins discordant for major anomalies are not at increased risk of PTD or IUGR compared to twins with no major anomalies

Characterization of RP1L1, a highly polymorphic paralog of the retinitis pigmentosa 1 (RP1) gene

Retinitis pigmentosa (RP) is a genetically heterogeneous inherited retinal degeneration which affects approximately 1 of 3,500 people worldwide. Individuals affected with retinitis pigmentosa exhibit night blindness, followed by a progressive reduction of visual field, which usually culminates in legal or complete blindness. Reduced or absent electroretinogram (ERG) and bone spicule-like pigmentary deposits accompany these symptoms Despite the large number of recent disease gene discoveries, much work still remains to completely understand the genetics of retinitis pigmentosa. Mutation analysis of the known disease-associated genes fails to identify mutations in at least 50% of cases and prevelences determined by linkage mapping are often inflated. For instance, despite the relatively large number of families originally mapped to the RP10 locus, mutations in the RP10 gene, IMPDH1, appear to account for less than 5% of adRP cases (unpublished data). The RP11 locus, estimated to be responsible for approximately 20% of adRP cases, also shows less than predicted mutation frequencies One strategy that can be used to find new adRP genes is to identify candidates that have sequence similarity to known adRP genes or that share functional pathways. For instance, three of the recently identified adRP disease-associated genes, HPRP3, PRPF8, and PRPF31, encode pre-mRNA splicing factors that participate in a common pathway. Using this strategy, we decided to characterize the nearest relative of RP1, and to determine if mutations in this newly characterized gene cause adRP. Purpose: To determine the full-length sequence of a gene with similarity to RP1 and to screen for mutations in this newly characterized gene, named retinitis pigmentosa 1-like 1(RP1L1). Since mutations in the RP1 gene cause autosomal dominant retinitis pigmentosa, it is possible that mutations in RP1&apos;s most sequence similar relative, RP1L1, may also be a cause of inherited retinal degeneration. Methods: A combination of cDNA clone sequencing, RACE, and database analysis were used to determine the RP1L1 mRNA sequence and its genomic organization. PCR analysis, semi-quantitative RT PCR, and in situ hybridization were used to determine the expression pattern of RP1L1. Single-strand conformational analysis and automated sequencing were used to screen probands from 60 adRP families for potential disease-causing mutations in RP1L1. Results: The human RP1L1 gene is encoded in 4 exons, which span 50 kb on chromosome 8p. The length of the RP1L1 mRNA is large, over 7 kb, but its exact length is variable between individuals due to the presence of several length polymorphisms, including a 48 bp repeat. RP1L1 encodes a protein with a minimal length of 2,400 amino acids and a predicted weight of 252 kDa. Expression of RP1L1 is limited to the retina and appears to be specific to photoreceptors. Mutational analysis of 60 autosomal dominant retinitis pigmentosa probands revealed the presence of 38 sequence substitutions in RP1L1. Over half of these substitutions result in alteration of the RP1L1 protein, but none of these substitutions appear to be pathogenic. Conclusions: The RP1L1 gene encodes a large, highly polymorphic, retinal-specific protein. No RP1L1 disease-causing mutations were identified in any of the samples tested, making it unlikely that mutations in RP1L1 are a frequent cause of autosomal dominant retinitis pigmentosa. Additional experiments will be needed to determine if mutations in RP1L1 cause other forms of inherited retinal degeneration