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1.
Article in English | MEDLINE | ID: mdl-37823835

ABSTRACT

The COVID-19 pandemic had a huge impact on medical services. Several measures have been implemented to reduce the risk of viral transmission. In this paper, we assessed the impact of these measures on surgical wound infection rates in patients post-cardiac surgery. Hypothesis testing was used to compare post-cardiac operation infection rates between the year prior to the COVID-19 pandemic being declared and the first 13 months of the pandemic. The infection rates in 969 patients with operations between 01/03/2019 and 29/02/2020 were compared to those of 925 patients with cardiac surgery between 01/03/2020 and 31/03/2021. Infection rates for various operative urgencies and infection types were analysed. To compare infection rates, a two-tailed pooled z-test using the difference in infection proportions was performed. A 5% significance level was used and only categories with at least 10 patients in both the pre-covid and covid populations were tested. For leg infections, only operations involving coronary artery bypass grafting were included. To ensure that any differences in outcomes were not due to differences in patient demographics resulting in unequal operative risks, Euroscore II values, a measure of cardiac operative risk, were compared between the pre-covid and post-covid cohorts. The Mann-Whitney U-test was used to determine whether the distributions of Euroscore II values were likely to be drawn from the same population. A significance level of 5% was used. A total of 1901 patients (932 during the COVID-19 pandemic) were included in this study. Significant reduction in post-operative infections for all patients undergoing cardiac surgery from 4.3% of patients before COVID to 1.5% during the pandemic. During the pandemic, fewer elective and more urgent operations were performed. This study suggests a significant role of iatrogenic causes in wound infections prior to the pandemic. The implementation of COVID-19 prevention measures in healthcare providers can reduce surgical infection rates. As COVID-19-related restrictions have been eased, we suggest maintaining them in healthcare providers to reduce the incidence of surgical wound infections.

2.
Environ Toxicol Pharmacol ; 100: 104119, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37028532

ABSTRACT

To account for global contamination events, we must identify direct and indirect pollutant effects. Although pollutants can have direct effects on individuals, it is unknown how a few contaminated individuals affect groups, a widespread social organization. We show environmentally relevant levels of cadmium (Cd) can have indirect social effects revealed in the social context of a larger group. Cd-contaminated individuals had poor vision and more aggressive responses, but no other behavioral effects. The presence of experienced Cd-exposed pairs in the groups had an indirect effect on the un-exposed individual's social interactions leading to the shoal becoming bolder and moving closer to a novel object than control groups. Because a few directly affected individuals could indirectly affect social behavior of the un-exposed majority, we believe that such acute but potentially important heavy metal toxicity could inform reliable predictions about the consequences of their use in a changing world.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Animals , Cadmium/toxicity , Zebrafish/physiology , Water Pollutants, Chemical/toxicity , Social Behavior
3.
Cells ; 10(9)2021 09 07.
Article in English | MEDLINE | ID: mdl-34571990

ABSTRACT

The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.


Subject(s)
Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/pathology , Endoplasmic Reticulum/physiology , Animals , Cytoskeleton , Humans , Lipids/biosynthesis , Membrane Proteins/metabolism , Microtubules , Mitochondria/metabolism , Mitochondrial Membranes/metabolism , Nuclear Envelope/metabolism , Structure-Activity Relationship
4.
Biosensors (Basel) ; 11(9)2021 Sep 09.
Article in English | MEDLINE | ID: mdl-34562917

ABSTRACT

Cortisol is a well established biomarker hormone that regulates many processes in the body and is widely referred to as the stress hormone. Cortisol can be used as a stress marker to allow for detection of stress levels in dogs during the training process. This test will indicate if they will handle the stress under the training or if they might be more suitable as an assistant or companion dog. An immunosensor for detection of cortisol was developed using electrochemical impedance spectroscopy (EIS). The sensor was characterized using chemical and topographical techniques. The sensor was calibrated and its sensitivity determined using a cortisol concentration range of 0.0005 to 50 µg/mL. The theoretical limit of detection was found to be 3.57 fg/mL. When the immunosensor was tested on canine saliva samples, cortisol was detected and measured within the relevant physiological ranges in dogs.


Subject(s)
Biosensing Techniques , Immunoassay , Animals , Biomarkers , Calibration , Dielectric Spectroscopy , Dogs , Electrochemical Techniques , Electrodes , Humans , Hydrocortisone , Limit of Detection , Point-of-Care Systems , Saliva , Service Animals
5.
Sci Rep ; 11(1): 16230, 2021 08 10.
Article in English | MEDLINE | ID: mdl-34376706

ABSTRACT

The endoplasmic reticulum (ER) is a eukaryotic subcellular organelle composed of tubules and sheet-like areas of membrane connected at junctions. The tubule network is highly dynamic and undergoes rapid and continual rearrangement. There are currently few tools to evaluate network organisation and dynamics. We quantified ER network organisation in Vero and MRC5 cells, and developed an analysis workflow for dynamics of established tubules in live cells. The persistence length, tubule length, junction coordination number and angles of the network were quantified. Hallmarks of imbalances in ER tension, indications of interactions with microtubules and other subcellular organelles, and active dynamics were observed. Clear differences in dynamic behaviour were observed for established tubules at different positions within the cell using itemset mining. We found that tubules with activity-driven fluctuations were more likely to be located away from the cell periphery and a population of peripheral tubules with no signs of active motion was found.


Subject(s)
Endoplasmic Reticulum/physiology , Fibroblasts/physiology , Lung/physiology , Microtubules/physiology , Animals , Chlorocebus aethiops , Fibroblasts/cytology , Humans , Lung/cytology , Vero Cells
6.
Gen Comp Endocrinol ; 281: 145-152, 2019 09 15.
Article in English | MEDLINE | ID: mdl-31199927

ABSTRACT

Amphibian populations are declining globally, so understanding how individuals respond to anthropogenic and environmental stressors may aid conservation efforts. Using a non-invasive water-borne hormone assay, we measured the release rates of two glucocorticoid hormones, corticosterone and cortisol, in Rio Grande Leopard frog, Rana berlandieri, tadpoles. We validated this method pharmacologically and biologically using an adrenocorticotropic hormone (ACTH) challenge, exposure to exogenous corticosterone, and an agitation test. We calculated the repeatability of hormone release rates, the recovery time from an acute stressor, and explored rearing methods for tadpoles. Tadpole corticosterone release rates increased following an ACTH challenge, exposure to exogenous corticosterone, and agitation, validating the use of water-borne hormone methods in this species. After exposure to an acute stressor via agitation, corticosterone release rates began to decline after 2 h and were lowest after 6 h, suggesting a relatively rapid recovery from an acute stressor. Tadpoles reared in groups had higher corticosterone release rates than tadpoles reared individually, and lost mass by Day 7, while tadpoles reared individually did not show a stress response, therefore either rearing method is viable, but have differing physiological costs for tadpoles. Repeatability of corticosterone release rates was moderate to high in R. berlandieri tadpoles, indicating that this species can show a response to selection and potentially respond to rapid environmental change. Our results show that the water-borne hormone assay is a viable way to measure glucocorticoids in this species and is useful in the field of conservation physiology for rare and endangered species.


Subject(s)
Breeding/methods , Corticosterone/metabolism , Hydrocortisone/metabolism , Stress, Physiological , Adrenocorticotropic Hormone/pharmacology , Animals , Larva/drug effects , Larva/metabolism , Rana pipiens/metabolism , Reproducibility of Results , Stress, Physiological/drug effects
7.
J Cancer Educ ; 32(4): 836-844, 2017 Dec.
Article in English | MEDLINE | ID: mdl-27037699

ABSTRACT

The US Department of Health and Human Services addresses clear communication in the informed consent process as part of the Notice of Proposed Rulemaking for revisions to the Common Rule. However, prior research has shown that participants may not fully comprehend research studies despite completion of an informed consent process. Our main goal was to provide plain language information about donation processes to a cancer biobank to supplement an informed consent form. We developed and conducted cognitive testing with supplemental brochures that clearly communicated information about three different models for consent (notice, broad and study-specific) to future use of biospecimens. During the brochure development process, we conducted qualitative, semi-structured, individual, in-person cognitive interviews among 14 women to examine participants' perceptions of the brochures. Each participant provided feedback regarding the understandability, graphics and layout, and cultural appropriateness of the brochures. Our findings demonstrate that these methods may be used to tailor consent form brochures, such as the ones developed here, to other populations. This study therefore adds to our understanding of how best to present content to help women from two different racial groups make informed decisions about participation in a cancer biobank.


Subject(s)
Biological Specimen Banks/statistics & numerical data , Comprehension , Informed Consent/psychology , Language , Pamphlets , Adult , Black or African American , Female , Humans , Middle Aged , United States , White People
8.
Oncologist ; 21(12): 1461-1470, 2016 12.
Article in English | MEDLINE | ID: mdl-27511904

ABSTRACT

BACKGROUND: Cancer patients often do not make informed decisions regarding clinical trial participation. This study evaluated whether a web-based decision aid (DA) could support trial decisions compared with our cancer center's website. METHODS: Adults diagnosed with cancer in the past 6 months who had not previously participated in a cancer clinical trial were eligible. Participants were randomized to view the DA or our cancer center's website (enhanced usual care [UC]). Controlling for whether participants had heard of cancer clinical trials and educational attainment, multivariable linear regression examined group on knowledge, self-efficacy for finding trial information, decisional conflict (values clarity and uncertainty), intent to participate, decision readiness, and trial perceptions. RESULTS: Two hundred patients (86%) consented between May 2014 and April 2015. One hundred were randomized to each group. Surveys were completed by 87 in the DA group and 90 in the UC group. DA group participants reported clearer values regarding trial participation than UC group participants reported (least squares [LS] mean = 15.8 vs. 32, p < .0001) and less uncertainty (LS mean = 24.3 vs. 36.4, p = .025). The DA group had higher objective knowledge than the UC group's (LS mean = 69.8 vs. 55.8, p < .0001). There were no differences between groups in intent to participate. CONCLUSIONS: Improvements on key decision outcomes including knowledge, self-efficacy, certainty about choice, and values clarity among participants who viewed the DA suggest web-based DAs can support informed decisions about trial participation among cancer patients facing this preference-sensitive choice. Although better informing patients before trial participation could improve retention, more work is needed to examine DA impact on enrollment and retention. IMPLICATIONS FOR PRACTICE: This paper describes evidence regarding a decision tool to support patients' decisions about trial participation. By improving knowledge, helping patients clarify preferences for participation, and facilitating conversations about trials, decision aids could lead to decisions about participation that better match patients' preferences, promoting patient-centered care and the ethical conduct of clinical research.


Subject(s)
Clinical Trials as Topic , Decision Support Techniques , Neoplasms/therapy , Patient Participation , Adult , Aged , Aged, 80 and over , Decision Making , Female , Humans , Male , Middle Aged , Patient Preference , Patient-Centered Care
9.
Med Decis Making ; 36(7): 911-22, 2016 10.
Article in English | MEDLINE | ID: mdl-25840904

ABSTRACT

BACKGROUND: The Affordable Care Act allows uninsured individuals to select health insurance from numerous private plans, a challenging decision-making process. This study examined the effectiveness of strategies to support health insurance decisions among the uninsured. METHODS: Participants (N = 343) from urban, suburban, and rural areas were randomized to 1 of 3 conditions: 1) a plain language table; 2) a visual condition where participants chose what information to view and in what order; and 3) a narrative condition. We administered measures assessing knowledge (true/false responses about key features of health insurance), confidence in choices (uncertainty subscale of the Decisional Conflict Scale), satisfaction (items from the Health Information National Trends Survey), preferences for insurance features (measured on a Likert scale from not at all important to very important), and plan choice. RESULTS: Although we did not find significant differences in knowledge, confidence in choice, or satisfaction across condition, participants across conditions made value-consistent choices, selecting plans that aligned with their preferences for key insurance features. In addition, those with adequate health literacy skills as measured by the Rapid Estimate of Adult Literacy in Medicine-Short Form (REALM-SF) had higher knowledge overall ([Formula: see text] = 6.1 v. 4.8, P < 0.001) and preferred the plain language table to the visual (P = 0.04) and visual to narrative (P = 0.0002) conditions, while those with inadequate health literacy skills showed no preference for study condition. A similar pattern was seen for those with higher subjective numeracy skills and higher versus lower education with regard to health insurance knowledge. Individuals with higher income felt less confident in their choices ([Formula: see text] = 28.7 v. 10.0, where higher numbers indicate less confidence/more uncertainty; P = 0.004). CONCLUSIONS: Those developing materials about the health insurance marketplace to support health insurance decisions might consider starting with plain language tables, presenting health insurance terminology in context, and organizing information according to ways the uninsured might use and value insurance features. Individuals with limited health literacy and numeracy skills and those with lower education face unique challenges selecting health insurance and weighing tradeoffs between cost and coverage.


Subject(s)
Decision Making , Insurance, Health , Adolescent , Adult , Female , Humans , Male , Middle Aged , Patient Protection and Affordable Care Act , United States , Young Adult
10.
J Community Genet ; 7(1): 41-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26304495

ABSTRACT

Biobanks are essential resources, and participation by individuals from diverse groups is needed. Various models of consent have been proposed for secondary research use of biospecimens, differing in level of donor control and information received. Data are needed regarding participant preferences for models of consent, particularly among minorities. We conducted qualitative semi-structured interviews with 60 women to examine their attitudes about different models of consent. Recruitment was stratified by race (Black/White) and prior biobank participation (yes/no). Two coders independently coded interview transcripts. Qualitative thematic analysis was conducted using NVivo 10. The majority of Black and White participants preferred "broad" consent (i.e., blanket permission for secondary research use of biospecimens), and the second most preferred model for both groups was "study-specific" consent (i.e., consent for each future research study). The qualitative analysis showed that participants selected their most preferred model for 3 major reasons: having enough information, having control over their sample, and being asked for permission. Least preferred was notice model (i.e., participants notified that biospecimens may be used in future research). Attitudes toward models of consent differed somewhat by race and prior biobank participation. Participants preferred models of consent for secondary research use of biospecimens that provided them with both specific and general information, control over their biospecimens, and asked them to give permission for use. Our findings suggest that it will be important for researchers to provide information about future uses of biospecimens to the extent possible and have an explicit permission step for secondary research use.

11.
J Health Commun ; 21(2): 148-58, 2016.
Article in English | MEDLINE | ID: mdl-26444848

ABSTRACT

As a result of the Affordable Care Act, millions of previously uninsured individuals are facing the daunting task of selecting health insurance. In order to better understand how to reach the uninsured and support their health insurance decision making, this study examined where the uninsured collect information about health insurance and the extent to which they trust those sources and media. We analyzed secondary data on health insurance information-seeking behaviors collected from a survey of 343 uninsured individuals. The Internet, mail, and television were among the most frequently used media, though all 3 had low trust scores. Participants sought information from health care providers and interpersonal sources less frequently but trusted it more than they trusted the media. Age, gender, race, and education were predictors of use and trust of different media and sources of health insurance information. Findings suggest that strategies that pair health care professionals, lay health advisors, or community liaisons with the ubiquity of the Internet may be a strong approach for delivering quality health insurance information to the uninsured. Tailoring messages might also be effective at reaching specific subgroups of the uninsured.


Subject(s)
Information Seeking Behavior , Insurance, Health , Medically Uninsured/psychology , Adolescent , Adult , Female , Humans , Male , Mass Media , Medically Uninsured/statistics & numerical data , Middle Aged , Trust , United States , Young Adult
12.
Milbank Q ; 92(1): 40-62, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24597555

ABSTRACT

CONTEXT: Implementing the Affordable Care Act (ACA) in 2014 will require effective enrollment and outreach efforts to previously uninsured individuals now eligible for coverage. METHODS: From 1996 to 2013, the Health Communication Research Laboratory conducted more than 40 original studies with more than 30,000 participants to learn how to improve the reach to and effectiveness of health information for low-income and racial/ethnic minority populations. We synthesized the findings from this body of research and used them to inform current challenges in implementing the ACA. FINDINGS: We found empirical support for 5 recommendations regarding partnerships, outreach, messages and messengers, life priorities of low-income individuals and families, and the information environment. We translated these into 12 action steps. CONCLUSIONS: Health communication science can inform the development and execution of strategies to increase the public's understanding of the ACA and to support the enrollment of eligible individuals into Medicaid or the Health Insurance Marketplace.


Subject(s)
Health Communication/methods , Health Insurance Exchanges/organization & administration , Information Dissemination/methods , Insurance Coverage/organization & administration , Medicaid/organization & administration , Medically Uninsured/legislation & jurisprudence , Patient Protection and Affordable Care Act/organization & administration , Evidence-Based Practice/methods , Humans , Minority Health , Poverty , United States
13.
Mol Ther Nucleic Acids ; 3: e145, 2014 Feb 04.
Article in English | MEDLINE | ID: mdl-24496437

ABSTRACT

TT-034 (PF-05095808) is a recombinant adeno-associated virus serotype 8 (AAV8) agent expressing three short hairpin RNA (shRNA) pro-drugs that target the hepatitis C virus (HCV) RNA genome. The cytosolic enzyme Dicer cleaves each shRNA into multiple, potentially active small interfering RNA (siRNA) drugs. Using next-generation sequencing (NGS) to identify and characterize active shRNAs maturation products, we observed that each TT-034-encoded shRNA could be processed into as many as 95 separate siRNA strands. Few of these appeared active as determined by Sanger 5' RNA Ligase-Mediated Rapid Amplification of cDNA Ends (5-RACE) and through synthetic shRNA and siRNA analogue studies. Moreover, NGS scrutiny applied on 5-RACE products (RACE-seq) suggested that synthetic siRNAs could direct cleavage in not one, but up to five separate positions on targeted RNA, in a sequence-dependent manner. These data support an on-target mechanism of action for TT-034 without cytotoxicity and question the accepted precision of substrate processing by the key RNA interference (RNAi) enzymes Dicer and siRNA-induced silencing complex (siRISC).Molecular Therapy-Nucleic Acids (2014) 3, e145; doi:10.1038/mtna.2013.73; published online 4 February 2014.

14.
Virus Res ; 179: 93-101, 2014 Jan 22.
Article in English | MEDLINE | ID: mdl-24246306

ABSTRACT

Flaviviruses related to hepatitis C virus (HCV) in suitable animal models may provide further insight into the role that cellular immunity contributes to spontaneous clearance of HCV. We characterised changes in lymphocyte populations in tamarins with an acute GBV-B infection, a hepatitis virus of the flaviviridae. Major immune cell populations were monitored in peripheral and intra-hepatic lymphocytes at high viraemia or following a period when peripheral virus was no longer detected. Limited changes in major lymphocyte populations were apparent during high viraemia; however, the proportions of CD3(+) lymphocytes decreased and CD20(+) lymphocytes increased once peripheral viraemia became undetectable. Intrahepatic lymphocyte populations increased at both time points post-infection. Distinct expression patterns of PD-1, a marker of T-cell activation, were observed on peripheral and hepatic lymphocytes; notably there was elevated PD-1 expression on hepatic CD4(+) T-cells during high viraemia, suggesting an activated phenotype, which decreased following clearance of peripheral viraemia. At times when peripheral vRNA was not detected, suggesting viral clearance, we were able to readily detect GBV-B RNA in the liver, indicative of long-term virus replication. This study is the first description of changes in lymphocyte populations during GBV-B infection of tamarins and provides a foundation for more detailed investigations of the responses that contribute to the control of GBV-B infection.


Subject(s)
Disease Models, Animal , Flaviviridae Infections/virology , GB virus B/physiology , Hepatitis, Viral, Human/virology , Liver/immunology , Saguinus , Animals , Flaviviridae Infections/immunology , GB virus B/immunology , Hepatitis, Viral, Human/immunology , Humans , Liver/virology , Lymphocyte Activation , Saguinus/immunology , Saguinus/virology , T-Lymphocytes/immunology , Viremia/immunology , Viremia/virology , Virus Replication
15.
J Clin Immunol ; 32(5): 1082-92, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22476912

ABSTRACT

BACKGROUND AND OBJECTIVE: Synthetic TLR7 agonists have been proposed as oral replacements for interferonα (IFNα) therapy in the treatment of hepatitis C virus infection. However, adverse effects, such as lymphopenia and cardiovascular irregularities, have been observed in the clinical following treatment with TLR7 agonists. We wished to understand and characterise the relationship between TLR7 agonism and adverse effects. METHODS: We compared responses to two prototypic TLR7 agonists (Resiquimod: R-848; and PF-04878691) in a mouse model and compared the responses to treatment with IFNα. We measured clinically relevant adverse effects such as lymphopenia and cardiovascular irregularities and related them to plasma drug levels and clinically relevant efficacy biomarkers such as the pro-inflammatory cytokine IP-10, 2'5'OAS and TLR7 receptor expression. RESULTS: By 2 h post dose all agents had induced a dose-dependent transient lymphopenia. IFNα increased heart rate immediately following dosing, persisting for 5 h, whilst PF-04878691 induced significant reductions in blood pressure. Lymphopenia co-incided with maximum plasma drug levels, raised levels of IP-10 and the auto-induction of TLR7 expression in the blood and lymph nodes. Peak levels of 2'5'OAS occurred at 24 h post-dose and only at doses which also induced lymphopenia. CONCLUSIONS: We conclude that systemic delivery of TLR7 agonists or IFNα induces similar exaggerated pharmacology, consistent with there being a narrow therapeutic window between efficacy and safety. This clinically validated mouse model will help to investigate whether more potent agonists or optimised dosing schedules, will be successful strategies for targeting TLR7 in patients.


Subject(s)
Aminoquinolines/adverse effects , Hypotension/chemically induced , Imidazoles/adverse effects , Lymphopenia/chemically induced , Sulfonamides/adverse effects , Toll-Like Receptor 7/agonists , 2',5'-Oligoadenylate Synthetase/metabolism , Aminoquinolines/blood , Aminoquinolines/pharmacokinetics , Animals , Biomarkers/metabolism , Blood Pressure/drug effects , Chemokine CXCL10/metabolism , Female , Heart Rate/drug effects , Hypotension/metabolism , Imidazoles/blood , Imidazoles/pharmacokinetics , Interferon-alpha/adverse effects , Interferon-alpha/blood , Interferon-alpha/pharmacokinetics , Liver/drug effects , Liver/metabolism , Lymph Nodes/drug effects , Lymph Nodes/metabolism , Lymphocyte Count , Lymphopenia/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Quinolines , Sulfonamides/blood , Sulfonamides/pharmacokinetics , Toll-Like Receptor 7/genetics , Toll-Like Receptor 7/metabolism
16.
Antimicrob Agents Chemother ; 56(3): 1364-75, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22203606

ABSTRACT

PF-05095808 is a novel biological agent for chronic hepatitis C virus (HCV) therapy. It comprises a recombinant adeno-associated virus (AAV) DNA vector packaged into an AAV serotype 8 capsid. The vector directs expression of three short hairpin RNAs (shRNAs) targeted to conserved regions of the HCV genome. These shRNAs are processed by the host cell into the small interfering RNAs which mediate sequence-specific cleavage of target regions. For small-molecule inhibitors the key screens needed to assess in vitro activity are well defined; we developed new assays to assess this RNA interference agent and so to understand its therapeutic potential. Following administration of PF-05095808 or corresponding synthetic shRNAs, sequence-specific antiviral activity was observed in HCV replicon and infectious virus systems. To quantify the numbers of shRNA molecules required for antiviral activity in vitro and potentially also in vivo, a universal quantitative PCR (qPCR) assay was developed. The number of shRNA molecules needed to drive antiviral activity proved to be independent of the vector delivery system used for PF-05095808 administration. The emergence of resistant variants at the target site of one shRNA was characterized. A novel RNA cleavage assay was developed to confirm the spectrum of activity of PF-05095808 against common HCV clinical isolates. In summary, our data both support antiviral activity consistent with an RNA interference mechanism and demonstrate the potential of PF-05095808 as a therapeutic agent for chronic HCV infection.


Subject(s)
Dependovirus/genetics , Genetic Therapy , Hepacivirus/genetics , Hepatitis C, Chronic/therapy , Base Sequence , Biological Assay , Capsid , Cell Line, Tumor , Drug Resistance, Viral/genetics , Genes, Reporter , Genetic Vectors , Genome, Viral , Hepacivirus/isolation & purification , Hepatitis C, Chronic/virology , Humans , Luciferases , Molecular Sequence Data , Polymerase Chain Reaction , RNA Cleavage , RNA Interference , RNA, Small Interfering/genetics , Replicon/genetics , Virus Replication/drug effects
17.
J Virol ; 84(14): 7288-99, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20427524

ABSTRACT

A low-molecular-weight human immunodeficiency virus type 1 (HIV-1) inhibitor, PF-68742 (molecular weight, 573), has been identified in a high-throughput screen for compounds that block HIV-1 envelope glycoprotein (Env)-mediated fusion. The compound is shown to be potent against R5 and X4 isolates in both cell-cell fusion and antiviral assays (50% effective concentrations of approximately 0.1 to 1 muM). Postfusion and HIV-1 pseudotyping control experiments confirm that PF-68742 is an entry inhibitor with Env as the specific target for antiviral action. PF-68742 was not able to block binding of monomeric gp120 to soluble CD4 or the binding of gp120:CD4 complexes to cell-associated CCR5, thus distinguishing PF-68742 from described gp120 antagonists and coreceptor binders. Escape variants of HIV-1(NL4-3) were selected, and all resistant viruses were found to contain a common G514R (HxB2 numbering) mutation in Env, located proximal to the furin cleavage site in the fusion peptide of gp41. When introduced into wild-type NL4-3 gp41, G514R conferred resistance to PF-68742. Resistance via G514R is shown to be associated with enhancement of virion infectivity by PF-68742 that may result from altered properties of inhibitor-bound Env, rather than from a loss of compound binding. Wild-type viruses and those with substitutions in the disulfide loop (DSL) region of gp41 were also examined for PF-68742 sensitivity. Here, complete resistance to PF-68742 was found to occur through changes outside of position 514, including in the gp41 DSL region. The results highlight PF-68742 as a starting point for novel therapies against HIV-1 and provide new insights into models of Env-mediated fusion.


Subject(s)
CCR5 Receptor Antagonists , HIV Envelope Protein gp41/metabolism , HIV Fusion Inhibitors/pharmacology , HIV-1/drug effects , HIV-1/metabolism , Pyridones/pharmacology , Receptors, CXCR4/antagonists & inhibitors , Sulfonamides/pharmacology , Virus Internalization/drug effects , Amino Acid Sequence , Animals , Cell Line , Dose-Response Relationship, Drug , HIV Envelope Protein gp120/metabolism , HIV Envelope Protein gp41/chemistry , HIV Envelope Protein gp41/genetics , HIV Fusion Inhibitors/chemistry , Humans , Molecular Sequence Data , Molecular Structure , Molecular Weight , Mutation , Receptors, CCR5/metabolism , Receptors, CXCR4/metabolism , Sequence Alignment
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