260 research outputs found

    A simple method for making disposable race tubes

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    Race tubes (Ryan, Beadle and Tatum 1943. Am. J. Bot. 30:784-799; Davis and de Serres 1970. 17A:79-143), glass tubes carrying strips of agar medium, are frequently used to measure the growth rates and circadian rhythmicity of Neurospora strains. However, the glass tubes can be quite difficult to fil, sterilize, and clean. The following is a simple and rapid method for using sterile disposable pipettes to make race tubes. We have had excellent results with Neurospora in these tubes

    Characterization of the free energy dependence of an interprotein electron transfer reaction by variation of pH and site-directed mutagenesis

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    AbstractThe interprotein electron transfer (ET) reactions of the cupredoxin amicyanin, which mediates ET from the tryptophan tryptophylquinone (TTQ) cofactor of methylamine dehydrogenase to cytochrome c-551i have been extensively studied. However, it was not possible to perform certain key experiments in that native system. This study examines the ET reaction from reduced amicyanin to an alternative electron acceptor, the diheme protein MauG. It was possible to vary the ΔG° for this ET reaction by simply changing pH to determine the dependence of kET on ΔG°. A P94A mutation of amicyanin significantly altered its oxidation–reduction midpoint potential value. It was not possible to study the ET from reduced P94A amicyanin to cytochrome c-551i in the native system because that reaction was kinetically coupled. However, the reaction from reduced P94A amicyanin to MauG was a true ET reaction and it was possible to determine values of reorganization energy (λ) and electronic coupling for the reactions of this variant as well as native amicyanin. Comparison of the λ values associated with the ET reactions between amicyanin and the TTQ of methylamine dehydrogenase, the diheme center of MauG and the single heme of cytochrome c-551i, provides insight into the factors that dictate the λ values for the respective reactions. These results demonstrate how study of ET reactions with alternative redox partner proteins can complement and enhance our understanding of the reactions with the natural redox partners, and further our understanding of mechanisms of protein ET reactions

    Immune DNA signature of T-cell infiltration in breast tumor exomes.

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    Tumor infiltrating lymphocytes (TILs) have been associated with favorable prognosis in multiple tumor types. The Cancer Genome Atlas (TCGA) represents the largest collection of cancer molecular data, but lacks detailed information about the immune environment. Here, we show that exome reads mapping to the complementarity-determining-region 3 (CDR3) of mature T-cell receptor beta (TCRB) can be used as an immune DNA (iDNA) signature. Specifically, we propose a method to identify CDR3 reads in a breast tumor exome and validate it using deep TCRB sequencing. In 1,078 TCGA breast cancer exomes, the fraction of CDR3 reads was associated with TILs fraction, tumor purity, adaptive immunity gene expression signatures and improved survival in Her2+ patients. Only 2/839 TCRB clonotypes were shared between patients and none associated with a specific HLA allele or somatic driver mutations. The iDNA biomarker enriches the comprehensive dataset collected through TCGA, revealing associations with other molecular features and clinical outcomes

    Early experience with an opt-in research register - Scottish Health Research Register (SHARE):a multi-method evaluation of participant recruitment performance

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    WS is a PhD student funded by the University of St Andrews.Background: Recruiting participants to a clinical study is a resource-intensive process with a high failure rate. The Scottish Health Research Register (SHARE) provides recruitment support service which helps researchers recruit participants by searching patients’ Electronic Health Records (EHRs). The current study aims to evaluate the performance of SHARE in participant recruitment. Methods: Recruitment projects eligible for evaluation were those that were conducted for clinical trials or observational studies and finished before 2020. For analysis of recruitment data, projects with incomplete data were excluded. For each project we calculated, from SHARE records, 1) the fraction of the participants recruited through SHARE as a percentage of the number requested by researchers (percentage fulfilled), 2) the percentage of the potential candidates provided by SHARE to researchers that were actually recruited (percentage provided and recruited), 3) the percentage of the participants recruited through SHARE of all the potentially eligible candidates identified by searching registrants’ EHRs (percentage identified and recruited). Research teams of the eligible projects were invited to participate in an anonymised online survey. Two metrics were derived from research teams’ responses, including a) the fraction of the recruited over the study target number of participants (percentage fulfilled), and b) the percentage of the participants recruited through SHARE among the candidates received from SHARE (percentage provided and recruited). Results: Forty-four projects were eligible for inclusion. Recruitment data for 24 projects were available (20 excluded because of missingness or incompleteness). Survey invites were sent to all the eligible research teams and received 12 responses. Analysis of recruitment data shows the overall percentage fulfilled was 34.2% (interquartile 13.3–45.1%), the percentage provided and recruited 29.3% (interquartile 20.6–52.4%) and percentage identified and recruited 4.9% (interquartile 2.6–10.2%). Based on the data reported by researchers, percentage fulfilled was 31.7% (interquartile 5.8–59.6%) and percentage provided and recruited was 20.2% (interquartile 8.2–31.0%). Conclusions: SHARE may be a valuable resource for recruiting participants for some clinical studies. Potential improvements are to expand the registrant base and to incorporate more data generated during patients’ different health care encounters into the candidate-searching step.Publisher PDFPeer reviewe
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