Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.

BACKGROUND: Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC). PURPOSE: To evaluate the test performance of imaging modalities for HCC. DATA SOURCES: MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists. STUDY SELECTION: Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI). DATA EXTRACTION: One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence. DATA SYNTHESIS: Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents. LIMITATIONS: Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations. CONCLUSION: CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. ( PROSPERO: CRD42014007016).

A proposed approach may help systematic reviews retain needed expertise while minimizing bias from nonfinancial conflicts of interest.

OBJECTIVES: Groups such as the Institute of Medicine emphasize the importance of attention to financial conflicts of interest. Little guidance exists, however, on managing the risk of bias for systematic reviews from nonfinancial conflicts of interest. We sought to create practical guidance on ensuring adequate clinical or content expertise while maintaining independence of judgment on systematic review teams. STUDY DESIGN AND SETTING: Workgroup members built on existing guidance from international and domestic institutions on managing conflicts of interest. We then developed practical guidance in the form of an instrument for each potential source of conflict. RESULTS: We modified the Institute of Medicine's definition of conflict of interest to arrive at a definition specific to nonfinancial conflicts. We propose questions for funders and systematic review principal investigators to evaluate the risk of nonfinancial conflicts of interest. Once risks have been identified, options for managing conflicts include disclosure followed by no change in the systematic review team or activities, inclusion on the team along with other members with differing viewpoints to ensure diverse perspectives, exclusion from certain activities, and exclusion from the project entirely. CONCLUSION: The feasibility and utility of this approach to ensuring needed expertise on systematic reviews and minimizing bias from nonfinancial conflicts of interest must be investigated.

A practice-based tool for engaging stakeholders in future research: a synthesis of current practices.

OBJECTIVE: A major goal of patient-centered outcomes and comparative effectiveness research is to increase the involvement of stakeholders throughout the research process to provide relevant and immediately actionable information. In this report, we review the current practices for engaging stakeholders in prioritizing research. STUDY DESIGN AND SETTING: To evaluate the range of approaches to stakeholder engagement, we reviewed the relevant literature and conducted semistructured interviews with (1) leading research organizations in the United States, Canada, and the United Kingdom; and (2) eight Evidence-based Practice Centers that engage stakeholders in comparative effectiveness research. RESULTS: We identified 56 articles related to stakeholder engagement in research prioritization. Studies and research organizations interviewed frequently used mixed methods approaches combining in-person venues with structured ranking or voting processes such as Delphi. EPCs similarly used group web/conference calls combined with Delphi ranking or voting. Research organizations reported difficulties engaging the public and policy makers, and EPCs reported challenges engaging federal stakeholders. CONCLUSION: Explicit and consistent use of terminology about stakeholders was absent. In-person techniques were useful to generate ideas and clarify issues, and quantitative methods were important in the prioritization of research. Recommendations for effective stakeholder engagement and a reporting checklist were developed from the accumulation of findings.

Comparative mapping in watermelon [Citrullus lanatus (Thunb.) Matsum. et Nakai].

The first single-nucleotide polymorphism (SNP) maps for watermelon [Citrullus lanatus (Thunb.) Matsum. et Nakai] were constructed and compared. Three populations were developed from crosses between two elite cultivars, Klondike Black Seeded × New Hampshire Midget (KBS × NHM), an elite cultivar and wild egusi accession, Strain II × PI 560023 (SII × Egusi) and an elite cultivar and a wild citron accession, ZWRM50 × PI 244019 (ZWRM × Citroides). The SII × Egusi and ZWRM × Citroides F(2) populations consisted of 187 and 182 individuals respectively while the KBS × NHM recombinant inbred line (RIL) population consisted of 164 lines. The length of the genetic maps were 1,438, 1,514 and 1,144 cM with average marker distances of 3.8, 4.2, and 3.4 cM for the KBS × NHM, SII × Egusi and ZWRM × Citroides populations, respectively. Shared markers were used to align the three maps so that the linkage groups (LGs) represented the 11 chromosomes of the species. Marker segregation distortion were observed in all three populations, but was highest (12.7 %) in the ZWRM × Citroides population, where Citroides alleles were favored. The three maps were used to construct a consensus map containing 378 SNP markers with an average distance of 5.1 cM between markers. Phenotypic data was collected for fruit weight (FWT), fruit length (FL), fruit width (FWD), fruit shape index (FSI), rind thickness (RTH) and Brix (BRX) and analyzed for quantitative trait loci (QTL) associated with these traits. A total of 40 QTL were identified in the three populations, including major QTL for fruit size and shape that were stable across genetic backgrounds and environments. The present study reports the first SNP maps for Citrullus and the first map constructed using two elite parents. We also report the first stable QTL associated with fruit size and shape in Citrullus lanatus. These maps, QTL and SNPs should be useful for the watermelon community and represent a significant step towards the potential use of molecular tools in watermelon breeding.

Proceedings of the SMBE Tri-National Young Investigators' Workshop 2005. Genome-wide associations between hybrid sterility QTL and marker transmission ratio distortion.

Marker transmission ratio distortion (TRD) in genetic mapping populations is frequently ascribed to selection against allelic combinations that cause hybrid incompatibility. Accordingly, genomic regions of TRD should be nonrandomly associated (colocated) with loci that underlie hybrid incompatibility. To directly test this hypothesis, we evaluated the genome-wide qualitative and quantitative agreement between chromosomal regions exhibiting marker TRD and those known to contain hybrid incompatibility quantitative trait locus (QTL). Incompatibility data came from a near-isogenic line (NIL) analysis of pollen and seed sterility in a cross between two Solanum (formerly Lycopersicon) species. We assessed (1) whether these incompatibility loci are colocated with markers that show significant TRD in two earlier generations preceding these introgression lines and (2) whether the magnitude of marker distortion quantitatively matches the estimated strength of selection against each incompatibility locus. We found evidence that TRD regions are chromosomally colocated with hybrid incompatibility loci more frequently than is expected by chance: pollen sterility QTLs were most closely associated with distorted heterozygote frequencies in later-generation backcrosses. Nonetheless, there was no evidence for an association between TRD and seed sterility and little evidence of a quantitative association between the magnitude of marker TRD and the fitness effects of heterospecific alleles at each chromosomal location. We propose and test a model (the "dance partner" model) to explain several cases where regions of TRD are not associated with hybrid incompatibility loci. Under this model, some NILs containing greater than one heterospecific introgression may not express hybrid incompatibility phenotypes because they carry both appropriate genetic dance partners required for a fully functional interaction. Accordingly, negative interactions expressed in earlier backcross generations are masked in these double-introgression NILs. Based on this model, we identify the location of several new putative pairwise interactors underlying hybrid incompatibility in this species cross.

Genetics of hybrid incompatibility between Lycopersicon esculentum and L. hirsutum.

We examined the genetics of hybrid incompatibility between two closely related diploid hermaphroditic plant species. Using a set of near-isogenic lines (NILs) representing 85% of the genome of the wild species Lycopersicon hirsutum (Solanum habrochaites) in the genetic background of the cultivated tomato L. esculentum (S. lycopersicum), we found that hybrid pollen and seed infertility are each based on 5-11 QTL that individually reduce hybrid fitness by 36-90%. Seed infertility QTL act additively or recessively, consistent with findings in other systems where incompatibility loci have largely been recessive. Genetic lengths of introgressed chromosomal segments explain little of the variation for hybrid incompatibility among NILs, arguing against an infinitesimal model of hybrid incompatibility and reinforcing our inference of a limited number of discrete incompatibility factors between these species. In addition, male (pollen) and other (seed) incompatibility factors are roughly comparable in number. The latter two findings contrast strongly with data from Drosophila where hybrid incompatibility can be highly polygenic and complex, and male sterility evolves substantially faster than female sterility or hybrid inviability. The observed differences between Lycopersicon and Drosophila might be due to differences in sex determination system, reproductive and mating biology, and/or the prevalence of sexual interactions such as sexual selection.

Frankensteins and cyborgs: visions of the global future in an age of technology.

This paper draws attention to the role of representation in the depiction of scientific and technological innovation as a means of understanding the narratives that circulate concerning the shape of things to come. It considers how metaphors play an important part in the conduct of scientific explanation, and how they do more than describe the world in helping also to shape expectations, normalise particular choices, establish priorities and create needs. In surveying the range of metaphorical responses to the digital and biotechnological age, we will see how technologies are regarded both as 'endangerment' and 'promise.' What we believe 'technology' is doing to 'us' reflects important implicit philosophies of technology and its relationship to human agency and political choice; yet we also need to be alert to the assumptions about 'human nature' itself which inform such reactions. The paper argues that embedded in the various representations implicit in the new technologies are crucial issues of identity, community and justice: what it means to be (post)human, who is (and who is not) entitled to the rewards of technological advancement, what priorities (and whose interests) will inform the shape of global humanity into the next century.