56 research outputs found
Comparison of preoperative, operative and postoperative variables in asymptomatic or minimally symptomatic patients to severely symptomatic patients three years after coronary artery bypass grafting: analysis of 423 patients
During a follow-up period of 3 years, among a consecutive series of 423 patients who gave informed consent for recatheterization both 1 and 3 years after coronary artery bypass grafting, the incidence of severely symptomatic patients with New York Heart Association class III or IV was 19% (79 of 423). The predictive value of approximately 80 clinical, angiographic and perioperative variables was too low to be of clinical value. Adverse clinical outcome was associated with a high closure rate of the grafts. Forty-six percent of the patients could not undergo reoperation because of unsuitable coronary anatomy. With intensive medical therapy half of these patients improved to functional class I or II, while of those patients who were reoperable 32% improved to class I or II with intensive pharmacologic treatment instead of reoperation. The nonresponders underwent reoperation, which resulted in improvement of symptoms to functional class I or II in most (83%)
Phenotypic screen for oxygen consumption rate identifies an anti-cancer naphthoquinone that induces mitochondrial oxidative stress.
A hallmark of cancer cells is their ability to reprogram nutrient metabolism. Thus, disruption to this phenotype is a potential avenue for anti-cancer therapy. Herein we used a phenotypic chemical library screening approach to identify molecules that disrupted nutrient metabolism (by increasing cellular oxygen consumption rate) and were toxic to cancer cells. From this screen we discovered a 1,4-Naphthoquinone (referred to as BH10) that is toxic to a broad range of cancer cell types. BH10 has improved cancer-selective toxicity compared to doxorubicin, 17-AAG, vitamin K3, and other known anti-cancer quinones. BH10 increases glucose oxidation via both mitochondrial and pentose phosphate pathways, decreases glycolysis, lowers GSH:GSSG and NAPDH/NAPD+ ratios exclusively in cancer cells, and induces necrosis. BH10 targets mitochondrial redox defence as evidenced by increased mitochondrial peroxiredoxin 3 oxidation and decreased mitochondrial aconitase activity, without changes in markers of cytosolic or nuclear damage. Over-expression of mitochondria-targeted catalase protects cells from BH10-mediated toxicity, while the thioredoxin reductase inhibitor auranofin synergistically enhances BH10-induced peroxiredoxin 3 oxidation and cytotoxicity. Overall, BH10 represents a 1,4-Naphthoquinone with an improved cancer-selective cytotoxicity profile via its mitochondrial specificity
Imaging Single Retrovirus Entry through Alternative Receptor Isoforms and Intermediates of Virus-Endosome Fusion
A large group of viruses rely on low pH to activate their fusion proteins that merge the viral envelope with an endosomal membrane, releasing the viral nucleocapsid. A critical barrier to understanding these events has been the lack of approaches to study virus-cell membrane fusion within acidic endosomes, the natural sites of virus nucleocapsid capsid entry into the cytosol. Here we have investigated these events using the highly tractable subgroup A avian sarcoma and leukosis virus envelope glycoprotein (EnvA)-TVA receptor system. Through labeling EnvA pseudotyped viruses with a pH-sensitive fluorescent marker, we imaged their entry into mildly acidic compartments. We found that cells expressing the transmembrane receptor (TVA950) internalized the virus much faster than those expressing the GPI-anchored receptor isoform (TVA800). Surprisingly, TVA800 did not accelerate virus uptake compared to cells lacking the receptor. Subsequent steps of virus entry were visualized by incorporating a small viral content marker that was released into the cytosol as a result of fusion. EnvA-dependent fusion with TVA800-expressing cells occurred shortly after endocytosis and delivery into acidic endosomes, whereas fusion of viruses internalized through TVA950 was delayed. In the latter case, a relatively stable hemifusion-like intermediate preceded the fusion pore opening. The apparent size and stability of nascent fusion pores depended on the TVA isoforms and their expression levels, with TVA950 supporting more robust pores and a higher efficiency of infection compared to TVA800. These results demonstrate that surface receptor density and the intracellular trafficking pathway used are important determinants of efficient EnvA-mediated membrane fusion, and suggest that early fusion intermediates play a critical role in establishing low pH-dependent virus entry from within acidic endosomes
The advance care planning PREPARE study among older Veterans with serious and chronic illness: study protocol for a randomized controlled trial
Conformational Changes in the Hepatitis B Virus Core Protein Are Consistent with a Role for Allostery in Virus AssemblyβΏ β
In infected cells, virus components must be organized at the right place and time to ensure assembly of infectious virions. From a different perspective, assembly must be prevented until all components are available. Hypothetically, this can be achieved by allosterically controlling assembly. Consistent with this hypothesis, here we show that the structure of the hepatitis B virus (HBV) core protein dimer, which can spontaneously self-assemble, is incompatible with capsid assembly. Systematic differences between core protein dimer and capsid conformations demonstrate linkage between the intradimer interface and interdimer contact surface. These structures also provide explanations for the capsid-dimer selectivity of some antibodies and the activities of assembly effectors. Solution studies suggest that the assembly-inactive state is more accurately an ensemble of conformations. Simulations show that allostery supports controlled assembly and results in capsids that are resistant to dissociation. We propose that allostery, as demonstrated in HBV, is common to most self-assembling viruses
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Improving a Full Range of Advance Care Planning Behavior Change and Action Domains: The PREPARE Randomized Trial.
CONTEXT:Advance care planning (ACP) engagement includes a wide range of behaviors and actions related to discussions and documentation, yet few ACP intervention studies measure the full process. OBJECTIVES:The objective of the study was to compare the effects of an easy-to-read advance directive (AD) versus an ACP web site plus the AD (PREPARE + AD) on Behavior Change Processes and Actions, including discussions and documentation. METHODS:Secondary data were from a completed ACP trial. Participants were primary care patients, β₯60 years old, with two comorbidities. We used the validated ACP Engagement Survey to examine six-month change in subscales measuring Behavior Change Processes (knowledge, contemplation, self-efficacy, readiness) and Actions (decision makers, quality of life, flexibility for decision makers, asking clinicians questions), specifically related to discussions and documentation. We used adjusted mixed-effects linear models to compare mean change and engagement over time. RESULTS:Compared to the AD-only, PREPARE + AD resulted in greater increases in all Behavior Change Processes subscales and Actions related to decision makers, quality of life, and flexibility (all P-values β€0.005). Both interventions significantly increased the proportion of participants who engaged in ACP discussions (PREPARE + AD, 99.5%; AD-only, 93.3%) and documentation (PREPARE + AD, 99.5%; AD-only, 90.4%), with greater increases for PREPARE + AD (all P-values <0.001). CONCLUSION:Both PREPARE plus an easy-to-read AD and an AD-only markedly increased ACP engagement in a full range of ACP behaviors, including discussions and documentation, and engagement was nearly 100% with PREPARE + AD. Future ACP studies should examine a full range of ACP behaviors beyond ADs and the impact of PREPARE and easy-to-read AD implementation on health care systems
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Effect of the PREPARE Website vs an Easy-to-Read Advance Directive on Advance Care Planning Documentation and Engagement Among Veterans: A Randomized Clinical Trial.
ImportanceDocumentation rates of patients' medical wishes are often low. It is unknown whether easy-to-use, patient-facing advance care planning (ACP) interventions can overcome barriers to planning in busy primary care settings.ObjectiveTo compare the efficacy of an interactive, patient-centered ACP website (PREPARE) with an easy-to-read advance directive (AD) to increase planning documentation.Design, setting, and participantsThis was a comparative effectiveness randomized clinical trial from April 2013 to July 2016 conducted at multiple primary care clinics at the San Francisco VA Medical Center. Inclusion criteria were age of a least 60 years; at least 2 chronic and/or serious conditions; and 2 or more primary care visits; and 2 or more additional clinic, hospital, or emergency room visits in the last year.InterventionsParticipants were randomized to review PREPARE plus an easy-to-read AD or the AD alone. There were no clinician and/or system-level interventions or education. Research staff were blinded for all follow-up measurements.Main outcomes and measuresThe primary outcome was new ACP documentation (ie, legal forms and/or discussions) at 9 months. Secondary outcomes included patient-reported ACP engagement at 1 week, 3 months, and 6 months using validated surveys of behavior change process measures (ie, 5-point knowledge, self-efficacy, readiness scales) and action measures (eg, surrogate designation, using a 0-25 scale). We used intention-to-treat, mixed-effects logistic and linear regression, controlling for time, health literacy, race/ethnicity, baseline ACP, and clustering by physician.ResultsThe mean (SD) age of 414 participants was 71 (8) years, 38 (9%) were women, 83 (20%) had limited literacy, and 179 (43%) were nonwhite. No participant characteristic differed significantly among study arms at baseline. Retention at 6 months was 90%. Advance care planning documentation 6 months after enrollment was higher in the PREPARE arm vs the AD-alone arm (adjusted 35% vs 25%; odds ratio, 1.61 [95% CI, 1.03-2.51]; Pβ=β.04). PREPARE also resulted in higher self-reported ACP engagement at each follow-up, including higher process and action scores; P <.001 at each follow-up).Conclusions and relevanceEasy-to-use, patient-facing ACP tools, without clinician- and/or system-level interventions, can increase planning documentation 25% to 35%. Combining the PREPARE website with an easy-to-read AD resulted in higher planning documentation than the AD alone, suggesting that PREPARE may increase planning documentation with minimal health care system resources.Trial registrationclinicaltrials.gov Identifier: NCT01550731
Mouse spermatocytes express CYP2E1 and respond to acrylamide exposure
Metabolism of xenobiotics by cytochrome P450s (encoded by the CYP genes) often leads to bio-activation, producing reactive metabolites that interfere with cellular processes and cause DNA damage. In the testes, DNA damage induced by xenobiotics has been associated with impaired spermatogenesis and adverse effects on reproductive health. We previously reported that chronic exposure to the reproductive toxicant, acrylamide, produced high levels of DNA damage in spermatocytes of Swiss mice. CYP2E1 metabolises acrylamide to glycidamide, which, unlike acrylamide, readily forms adducts with DNA. Thus, to investigate the mechanisms of acrylamide toxicity in mouse male germ cells, we examined the expression of the CYP, CYP2E1, which metabolises acrylamide. Using Q-PCR and immunohistochemistry, we establish that CYP2E1 is expressed in germ cells, in particular in spermatocytes. Additionally, CYP2E1 gene expression was upregulated in these cells following in vitro acrylamide exposure (1 ΞΌM, 18 h). Spermatocytes were isolated and treated with 1 ΞΌM acrylamide or 0.5 ΞΌM glycidamide for 18 hours and the presence of DNA-adducts was investigated using the comet assay, modified to detect DNA-adducts. Both compounds produced significant levels of DNA damage in spermatocytes, with a greater response observed following glycidamide exposure. A modified comet assay indicated that direct adduction of DNA by glycidamide was a major source of DNA damage. Oxidative stress played a small role in eliciting this damage, as a relatively modest effect was found in a comet assay modified to detect oxidative adducts following glycidamide exposure, and glutathione levels remained unchanged following treatment with either compound. Our results indicate that the male germ line has the capacity to respond to xenobiotic exposure by inducing detoxifying enzymes, and the DNA damage elicited by acrylamide in male germ cells is likely due to the formation of glycidamide adducts
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Engaging Diverse English- and Spanish-Speaking Older Adults in Advance Care Planning: The PREPARE Randomized Clinical Trial.
ImportanceAdvance care planning improves the receipt of medical care aligned with patients' values; however, it remains suboptimal among diverse patient populations. To mitigate literacy, cultural, and language barriers to advance care planning, easy-to-read advance directives and a patient-directed, online advance care planning program called PREPARE For Your Care (PREPARE) were created in English and Spanish.ObjectiveTo compare the efficacy of PREPARE plus an easy-to-read advance directive with an advance directive alone to increase advance care planning documentation and patient-reported engagement.Design, setting, and participantsA comparative efficacy randomized clinical trial was conducted from February 1, 2014, to November 30, 2017, at 4 safety-net, primary-care clinics in San Francisco among 986 English-speaking or Spanish-speaking primary care patients 55 years or older with 2 or more chronic or serious illnesses.InterventionsParticipants were randomized to PREPARE plus an easy-to-read advance directive (PREPARE arm) or the advance directive alone. There were no clinician-level or system-level interventions. Staff were blinded for all follow-up measurements.Main outcomes and measuresThe primary outcome was documentation of new advance care planning (ie, legal forms and/or documented discussions) at 15 months. Patient-reported outcomes included advance care planning engagement at baseline, 1 week, 3 months, 6 months, and 12 months using validated surveys. Intention-to-treat analyses were performed using mixed-effects logistic and linear regression, controlling for time, health literacy, and baseline advance care planning, clustering by physician, and stratifying by language.ResultsAmong the 986 participants (603 women and 383 men), the mean (SD) age was 63.3 (6.4) years, 387 of 975 (39.7%) had limited health literacy, and 445 (45.1%) were Spanish speaking. No participant characteristic differed between the 2 groups, and retention was 85.9% (832 of 969) among survivors. Compared with the advance directive alone, PREPARE resulted in a higher rate of advance care planning documentation (unadjusted, 43.0% [207 of 481] vs 33.1% [167 of 505]; Pβ<β.001; adjusted, 43.0% vs 32.0%; Pβ<β.001) and higher self-reported increased advance care planning engagement scores (98.1% vs 89.5%; Pβ<β.001). Results remained significant among English speakers and Spanish speakers.Conclusions and relevanceThe patient-facing PREPARE program and an easy-to-read advance directive, without clinician-level or system-level interventions, increased documentation of advance care planning and patient-reported engagement, with statistically higher gains for PREPARE vs advance directive alone. These tools may mitigate literacy and language barriers to advance care planning, allow patients to begin planning on their own, and could substantially improve the process for diverse English-speaking and Spanish-speaking populations.Trial registrationClinicalTrials.gov identifiers: NCT01990235 and NCT02072941
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Effect of the PREPARE Website vs an Easy-to-Read Advance Directive on Advance Care Planning Documentation and Engagement Among Veterans: A Randomized Clinical Trial.
ImportanceDocumentation rates of patients' medical wishes are often low. It is unknown whether easy-to-use, patient-facing advance care planning (ACP) interventions can overcome barriers to planning in busy primary care settings.ObjectiveTo compare the efficacy of an interactive, patient-centered ACP website (PREPARE) with an easy-to-read advance directive (AD) to increase planning documentation.Design, setting, and participantsThis was a comparative effectiveness randomized clinical trial from April 2013 to July 2016 conducted at multiple primary care clinics at the San Francisco VA Medical Center. Inclusion criteria were age of a least 60 years; at least 2 chronic and/or serious conditions; and 2 or more primary care visits; and 2 or more additional clinic, hospital, or emergency room visits in the last year.InterventionsParticipants were randomized to review PREPARE plus an easy-to-read AD or the AD alone. There were no clinician and/or system-level interventions or education. Research staff were blinded for all follow-up measurements.Main outcomes and measuresThe primary outcome was new ACP documentation (ie, legal forms and/or discussions) at 9 months. Secondary outcomes included patient-reported ACP engagement at 1 week, 3 months, and 6 months using validated surveys of behavior change process measures (ie, 5-point knowledge, self-efficacy, readiness scales) and action measures (eg, surrogate designation, using a 0-25 scale). We used intention-to-treat, mixed-effects logistic and linear regression, controlling for time, health literacy, race/ethnicity, baseline ACP, and clustering by physician.ResultsThe mean (SD) age of 414 participants was 71 (8) years, 38 (9%) were women, 83 (20%) had limited literacy, and 179 (43%) were nonwhite. No participant characteristic differed significantly among study arms at baseline. Retention at 6 months was 90%. Advance care planning documentation 6 months after enrollment was higher in the PREPARE arm vs the AD-alone arm (adjusted 35% vs 25%; odds ratio, 1.61 [95% CI, 1.03-2.51]; Pβ=β.04). PREPARE also resulted in higher self-reported ACP engagement at each follow-up, including higher process and action scores; P <.001 at each follow-up).Conclusions and relevanceEasy-to-use, patient-facing ACP tools, without clinician- and/or system-level interventions, can increase planning documentation 25% to 35%. Combining the PREPARE website with an easy-to-read AD resulted in higher planning documentation than the AD alone, suggesting that PREPARE may increase planning documentation with minimal health care system resources.Trial registrationclinicaltrials.gov Identifier: NCT01550731
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