969 research outputs found

    Legal liabilities in research: early lessons from North America

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    The legal risks associated with health research involving human subjects have been highlighted recently by a number of lawsuits launched against those involved in conducting and evaluating the research. Some of these cases have been fully addressed by the legal system, resulting in judgments that provide some guidance. The vast majority of cases have either settled before going to trial, or have not yet been addressed by the courts, leaving us to wonder what might have been and what guidance future cases may bring. What is striking about the lawsuits that have been commenced is the broad range of individuals/institutions that are named as defendants and the broad range of allegations that are made. The research community should take this early experience as a warning and should reflect carefully on practices where research involving human subjects is concerned

    Plasmodium translocon component EXP2 facilitates hepatocyte invasion

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    Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the mosquito and liver stage of infection, their function remains unexplored. Here, using a combination of genetic and chemical assays, we show that the translocon component Exported Protein 2 (EXP2) is critical for invasion of hepatocytes. EXP2 is a pore-forming protein that is secreted from the sporozoite upon contact with the host cell milieu. EXP2-deficient sporozoites are impaired in invasion, which can be rescued by the exogenous administration of recombinant EXP2 and alpha-hemolysin (an S. aureus pore-forming protein), as well as by acid sphingomyelinase. The latter, together with the negative impact of chemical and genetic inhibition of acid sphingomyelinase on invasion, reveals that EXP2 pore-forming activity induces hepatocyte membrane repair, which plays a key role in parasite invasion. Overall, our findings establish a novel and critical function for EXP2 that leads to an active participation of the host cell in Plasmodium sporozoite invasion, challenging the current view of the establishment of liver stage infection

    The Effect of Financial Incentives on Patient Decisions to Undergo Low‐value Head Computed Tomography Scans

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    BackgroundExcessive diagnostic testing and defensive medicine contribute to billions of dollars in avoidable costs in the United States annually. Our objective was to determine the influence of financial incentives, accompanied with information regarding test risk and benefit, on patient preference for diagnostic testing.MethodsWe conducted a cross‐sectional survey of patients at the University of Michigan emergency department (ED). Each participant was presented with a hypothetical scenario involving an ED visit following minor traumatic brain injury. Participants were given information regarding potential benefit (detecting brain hemorrhage) and risk (developing cancer) of head computed tomography scan, as well as an incentive of 0or0 or 100 to forego testing. We used 0.1 and 1% for test benefit and risk, and values for risk, benefit, and financial incentive varied across participants. Our primary outcome was patient preference to undergo testing. We also collected demographic and numeracy information. We then used logistic regression to estimate odds ratios (ORs), which were adjusted for multiple potential confounders. Our sample size was designed to find at least 300 events (preference for testing) to allow for inclusion of up to 30 covariates in fully adjusted models. We had 85% to 90% power to detect a 10% absolute difference in testing rate across groups, assuming a 95% significance level.ResultsWe surveyed 913 patients. Increasing test benefit from 0.1% to 1% significantly increased test acceptance (adjusted OR [AOR] = 1.6, 95% confidence interval [CI] = 1.2 to 2.1) and increasing test risk from 0.1% to 1% significantly decreased test acceptance (AOR = 0.70, 95% CI = 0.52 to 0.93). Finally, a $100 incentive to forego low‐value testing significantly reduced test acceptance (AOR = 0.6; 95% CI = 0.4 to 0.8).ConclusionsProviding financial incentives to forego testing significantly decreased patient preference for testing, even when accounting for test benefit and risk. This work is preliminary and hypothetical and requires confirmation in larger patient cohorts facing these actual decisions.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151851/1/acem13823_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151851/2/acem13823-sup-0001-DataSupplementS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151851/3/acem13823.pd

    Telomere Length Shows No Association with BRCA1 and BRCA2 Mutation Status

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    This study aimed to determine whether telomere length (TL) is a marker of cancer risk or genetic status amongst two cohorts of BRCA1 and BRCA2 mutation carriers and controls. The first group was a prospective set of 665 male BRCA1/2 mutation carriers and controls (mean age 53 years), all healthy at time of enrolment and blood donation, 21 of whom have developed prostate cancer whilst on study. The second group consisted of 283 female BRCA1/2 mutation carriers and controls (mean age 48 years), half of whom had been diagnosed with breast cancer prior to enrolment. TL was quantified by qPCR from DNA extracted from peripheral blood lymphocytes. Weighted and unweighted Cox regressions and linear regression analyses were used to assess whether TL was associated with BRCA1/2 mutation status or cancer risk. We found no evidence for association between developing cancer or being a BRCA1 or BRCA2 mutation carrier and telomere length. It is the first study investigating TL in a cohort of genetically predisposed males and although TL and BRCA status was previously studied in females our results don't support the previous finding of association between hereditary breast cancer and shorter TL

    Toxicity and genotoxicity of wastewater from gasoline stations

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    The toxicity and genotoxicity of wastewater from eight gasoline stations in Brasília, Brazil's capital city, was studied by assessing chromosomal aberrations, chromosomal malsegregation and the mitotic index in Alliumcepa root cells, and the occurrence of micronucleus and nuclear abnormalities in peripheral erythrocytes of tilapia fish (Oreochromis niloticus). The content of gasoline station effluents was also analyzed based on several physico-chemical parameters. None of the wastewater samples was genotoxic to A. cepa root cells, although cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear abnormalities and fish mortality. These results show that although the effluent from gasoline stations is processed by an oil/water separation system before being discharged into the main sewage system, the wastewater still contains toxic compounds

    Noradrenergic Control of Gene Expression and Long-Term Neuronal Adaptation Evoked by Learned Vocalizations in Songbirds

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    Norepinephrine (NE) is thought to play important roles in the consolidation and retrieval of long-term memories, but its role in the processing and memorization of complex acoustic signals used for vocal communication has yet to be determined. We have used a combination of gene expression analysis, electrophysiological recordings and pharmacological manipulations in zebra finches to examine the role of noradrenergic transmission in the brain’s response to birdsong, a learned vocal behavior that shares important features with human speech. We show that noradrenergic transmission is required for both the expression of activity-dependent genes and the long-term maintenance of stimulus-specific electrophysiological adaptation that are induced in central auditory neurons by stimulation with birdsong. Specifically, we show that the caudomedial nidopallium (NCM), an area directly involved in the auditory processing and memorization of birdsong, receives strong noradrenergic innervation. Song-responsive neurons in this area express α-adrenergic receptors and are in close proximity to noradrenergic terminals. We further show that local α-adrenergic antagonism interferes with song-induced gene expression, without affecting spontaneous or evoked electrophysiological activity, thus dissociating the molecular and electrophysiological responses to song. Moreover, α-adrenergic antagonism disrupts the maintenance but not the acquisition of the adapted physiological state. We suggest that the noradrenergic system regulates long-term changes in song-responsive neurons by modulating the gene expression response that is associated with the electrophysiological activation triggered by song. We also suggest that this mechanism may be an important contributor to long-term auditory memories of learned vocalizations
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