Controlling heme redox properties in peptide amphiphile fibers with sequence and heme loading ratio

Controlling the reduction midpoint potential of heme B is a key factor in many bioelectrochemical reactions, including long-range electron transport. Currently, there are a number of globular model protein systems to study this biophysical parameter; however, there are none for large polymeric protein model systems (e.g., the OmcS protein from G. sulfurreducens). Peptide amphiphiles, short peptides with a lipid tail that polymerize into fibrous structures, fill this gap. Here, we show a peptide amphiphile model system where one can tune the electrochemical potential of heme B by changing the loading ratio and peptide sequence. Changing the loading ratio resulted in the most significant increase, with values as high as -22 mV down to -224 mV. Circular dichroism spectra of certain sequences show Cotton effects at lower loading ratios that disappear as more heme B is added, indicating an ordered environment that becomes disrupted if heme B is overpacked. These findings can contribute to the design of functional self-assembling biomaterials.

Neoadjuvant Radiation Therapy in the Treatment of Breast Cancer

PURPOSE/OBJECTIVE(S)

Radiation therapy improves locoregional control and increases breast cancer patient's survival. Its neoadjuvant setting is a rarely used alternative that favors tumor resectability and, in addition, allows immediate breast reconstruction. This study aims to characterize locally advanced breast cancer patients that were treated with neoadjuvant radiotherapy (naRT), its indications and results.

MATERIALS/METHODS

Medical records were reviewed retrospectively. All patients diagnosed with breast cancer treated with curative-intent naRT in a Chilean oncologic hospital between January 2017 and 2019 were included. Inflammatory breast cancer cases and sarcomas were excluded. We described demographic, clinical and treatment characteristics, naRT indications and outcomes.

RESULTS

Information was collected from 112 patients (98% women) referred from 7 public hospitals. The median age was 57 years [28-85 years]. At diagnosis, 78% corresponded to clinical stage cT4b, and 83% had cN+ axilla (axillary biopsy was performed in 44 cases, 35 were positive). 53% were classified as luminal B, 19% as triple negative, 17% as luminal A, and 11% as HER2 enriched. 98% of patients began treatment with neoadjuvant systemic therapy (91 patients received chemotherapy and 19 patients hormone therapy). naRT indications were: immediate breast reconstruction in 23% and contraindication or unsatisfactory response to systemic therapy in 77%. In 99% of naRT the dose was 45-50 Gy to the breast/chest wall and peripheral lymphatics. 86% of patients underwent surgery (14 patients did not undergo surgery due to disease progression or because they refused surgery and 2 patients were on the waiting list at the time of follow up). Immediate breast reconstruction was performed in 31 patients with a median age of 45 years, all of them were derived from 2 referral centers that suggest this altered sequence of treatments. Surgical biopsies of 96 patients were reviewed: 13% had pathological complete response in the breast/chest wall, 55% in the axilla, and 12% at both levels. 30% of post-surgical complications were reported in the subgroup of patients who continued follow-up in our institution (total of 47 patients). With a median follow-up of 29 months, 18% of the patients had died from breast cancer.

CONCLUSION

naRT is not only an option when systemic therapy is not a good alternative, but also favors resectability of locally advanced tumors making pathological complete response and immediate breast reconstruction possible in selected cases, obtaining an oncological and reconstructive objective in the same surgery.

Impact of acute psychosocial stress on attentional control in humans. A study of evoked potentials and pupillary response

Psychosocial stress has increased considerably in our modern lifestyle, affecting global mental health. Deficits in attentional control are cardinal features of stress disorders and pathological anxiety. Studies suggest that changes in the locus coeruleus-norepinephrine system could underlie the effects of stress on top-down attentional control. However, the impact of psychosocial stress on attentional processes and its underlying neural mechanisms are poorly understood. This study aims to investigate the effect of psychosocial stress on attentional processing and brain signatures. Evoked potentials and pupillary activity related to the oddball auditory paradigm were recorded before and after applying the Montreal Imaging Stress Task (MIST). Electrocardiogram (ECG), salivary cortisol, and subjective anxiety/stress levels were measured at different experimental periods. The control group experienced the same physical and cognitive effort but without the psychosocial stress component. The results showed that stressed subjects exhibited decreased P3a and P3b amplitude, pupil phasic response, and correct responses. On the other hand, they displayed an increase in Mismatch Negativity (MMN). N1 amplitude after MIST only decreased in the control group. We found that differences in P3b amplitude between the first and second oddball were significantly correlated with pupillary dilation and salivary cortisol levels. Our results suggest that under social-evaluative threat, basal activity of the coeruleus-norepinephrine system increases, enhancing alertness and decreasing voluntary attentional resources for the cognitive task. These findings contribute to understanding the neurobiological basis of attentional changes in pathologies associated with chronic psychosocial stress.

A13 THE RATE OF ADVERSE EVENTS AFTER COVID-19 VACCINATION IS SIMILAR IN PATIENTS WITH CELIAC DISEASE AND NON-CELIAC POPULATION: RESULTS OF A LARGE INTERNATIONAL CROSS-SECTIONAL STUDY

Background

Patients with celiac disease (CeD) reported increased COVID-19 vaccine hesitancy due to a fear of adverse events (AEs). However, the risk of AEs post-COVID-19 vaccination in patients with CeD is unknown.

Purpose

To assess whether the rate of common side effects (SEs) and AEs due to COVID vaccines are higher in patients with CeD compared to a non-CeD population.

Method

We conducted a collaborative international cross-sectional study in 16 countries between April 2022 and July 2022. An online survey was distributed to patients with CeD through patients’ local societies, and to non-CeD from the general population in each country through social media posts, word-of-mouth, and through academic institutions. We collected data on participant demographics, medical conditions, CeD diagnosis, GFD adherence, history of COVID-19 vaccinations (type and doses) and self-reported SEs and AEs post-COVID-19 vaccine. SEs included pain/swelling at the site, fatigue, fever, chills, nausea and/or headaches. AEs included thrombosis, myocarditis, anaphylactic reaction, and hospitalization related to the vaccine. Logistic regression models were used to assess predictors such as CeD diagnosis, age, gender, vaccine type and comorbidities on the likelihood of reporting SEs and AEs post-vaccine.

Result(s)

: A total of 17,795 participants completed the survey, 13,638 with CeD (median age of 45[27]) and 4,157 non-CeD controls (median age of 43[20]). There were no significant differences in sex between CeD and controls. Overall, CeD patients had similar odds of SEs compared with non-CeD individuals (aOR=1.02;95% CI=0.92-1.14). SEs were slightly increased only in the second dose of the vaccine in the CeD population compared to non-CeD individuals (aOR= 1.35; 95% CI=1.19-1.53). The most common reported SEs in CeD and controls were pain/swelling at the injection site (29% vs 23 %, p< 0.0001) and fatigue (29% vs 24%, p<0.0001). The odds of SEs were higher with Moderna Spikevax, AstraZeneca/Oxford and Johnson and Johnson vaccines than after the Pfizer vaccine (p< 0.0001). The overall rate of AEs post-vaccine was similar between patients with CeD and non-CeD individuals (aOR= 1.29; 95% CI= 0.89-1.87). Overall, female gender, older age, GFD adherence, respiratory conditions, obesity and receiving immunosuppressive medications increased the odds of SEs, while only age and a history of allergies increased the odds of AEs.

Conclusion(s)

In this large international study, patients with CeD reported similar rates of SEs and AEs post-COVID vaccine compared to non-CeD individuals. This information is highly relevant as it addresses the main concern leading to COVID-19 vaccine hesitancy in CeD patients.

Disclosure of Interest

None Declared

Population pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing regimens

PURPOSE

This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme.

METHODS

Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC_0-24 h/MIC ratio ≥ 125.

RESULTS

A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance.

CONCLUSION

The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC_0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m²) in children < 40 kg would be needed for the strains with highest MIC (16% of Pseudomonas aeruginosa and 47% of Staphylococcus aureus). The oral recommended dose of 20 mg/kg q12h (not exceeding 750 mg) would cover bacteria with MICs ≤ 0.125 but may be insufficient for bacteria with higher MIC and a dose increase according bodyweight and eGFR would be needed. These doses should be prospectively confirmed, and a therapeutic drug monitoring could be used to refine them individually.

Risk perception and knowledge of COVID-19 in patients with celiac disease

BACKGROUND

We recently demonstrated that the odds of contracting coronavirus disease 2019 (COVID-19) in patients with celiac disease (CeD) is similar to that of the general population. However, how patients with CeD perceive their COVID-19 risk may differ from their actual risk.

AIM

To investigate risk perceptions of contracting COVID-19 in patients with CeD and determine the factors that may influence their perception.

METHODS

We distributed a survey throughout 10 countries between March and June 2020 and collected data on demographics, diet, COVID-19 testing, and risk perceptions of COVID-19 in patients with CeD. Participants were recruited through various celiac associations, clinic visits, and social media. Risk perception was assessed by asking individuals whether they believe patients with CeD are at an increased risk of contracting COVID-19 when compared to the general population. Logistic regression was used to determine the influencing factors associated with COVID-19 risk perception, such as age, sex, adherence to a gluten-free diet (GFD), and comorbidities such as cardiac conditions, respiratory conditions, and diabetes. Data was presented as adjusted odds ratios (aORs)

RESULTS

A total of 10737 participants with CeD completed the survey. From them, 6019 (56.1%) patients with CeD perceived they were at a higher risk or were unsure if they were at a higher risk of contracting COVID-19 compared to the non-CeD population. A greater proportion of patients with CeD perceived an increased risk of contracting COVID-19 when compared to infections in general due to their CeD (56.1% vs 26.7%, P < 0.0001). Consequently, 34.8% reported taking extra COVID-19 precautions as a result of their CeD. Members of celiac associations were less likely to perceive an increased risk of COVID-19 when compared to non-members (49.5% vs 57.4%, P < 0.0001). Older age (aOR: 0.99; 95%CI: 0.99 to 0.99, P < 0.001), male sex (aOR: 0.84; 95%CI: 0.76 to 0.93, P = 0.001), and strict adherence to a GFD (aOR: 0.89; 95%CI: 0.82 to 0.96, P = 0.007) were associated with a lower perception of COVID-19 risk and the presence of comorbidities was associated with a higher perception of COVID-19 risk (aOR: 1.38; 95%CI: 1.22 to 1.54, P < 0.001).

CONCLUSION

Overall, high levels of risk perceptions, such as those found in patients with CeD, may increase an individual’s pandemic-related stress and contribute to negative mental health consequences. Therefore, it is encouraged that public health officials maintain consistent communication with the public and healthcare providers with the celiac community. Future studies specifically evaluating mental health in CeD could help determine the consequences of increased risk perceptions in this population.

The Risk of Contracting COVID-19 Is Not Increased in Patients With Celiac Disease

The World Health Organization declared coronavirus disease-2019 (COVID-19) a global pandemic in March 2020. Since then, there are more than 34 million cases of COVID-19 leading to more than 1 million deaths worldwide. Numerous studies suggest that celiac disease (CeD), a chronic immune-mediated gastrointestinal condition triggered by gluten, is associated with an increased risk of respiratory infections.^1-3 However, how it relates to the risk of COVID-19 is unknown. To address this gap, we conducted a cross-sectional study to evaluate whether patients with self-reported CeD are at an increased risk of contracting COVID-19.

The feasibility and reliability of actigraphy to monitor sleep in intensive care patients: an observational study

BACKGROUND

Sleep amongst intensive care patients is reduced and highly fragmented which may adversely impact on recovery. The current challenge for Intensive Care clinicians is identifying feasible and accurate assessments of sleep that can be widely implemented. The objective of this study was to investigate the feasibility and reliability of a minimally invasive sleep monitoring technique compared to the gold standard, polysomnography, for sleep monitoring.

METHODS

Prospective observational study employing a within subject design in adult patients admitted to an Intensive Care Unit. Sleep monitoring was undertaken amongst minimally sedated patients via concurrent polysomnography and actigraphy monitoring over a 24-h duration to assess agreement between the two methods; total sleep time and wake time.

RESULTS

We recruited 80 patients who were mechanically ventilated (24%) and non-ventilated (76%) within the intensive care unit. Sleep was found to be highly fragmented, composed of numerous sleep bouts and characterized by abnormal sleep architecture. Actigraphy was found to have a moderate level of overall agreement in identifying sleep and wake states with polysomnography (69.4%; K = 0.386, p < 0.05) in an epoch by epoch analysis, with a moderate level of sensitivity (65.5%) and specificity (76.1%). Monitoring accuracy via actigraphy was improved amongst non-ventilated patients (specificity 83.7%; sensitivity 56.7%). Actigraphy was found to have a moderate correlation with polysomnography reported total sleep time (r = 0.359, p < 0.05) and wakefulness (r = 0.371, p < 0.05). Bland-Altman plots indicated that sleep was underestimated by actigraphy, with wakeful states overestimated.

CONCLUSIONS

Actigraphy was easy and safe to use, provided moderate level of agreement with polysomnography in distinguishing between sleep and wakeful states, and may be a reasonable alternative to measure sleep in intensive care patients. Clinical Trial Registration number ACTRN12615000945527 (Registered 9/9/2015).

Amyloid precursor protein is a restriction factor that protects against Zika virus infection in mammalian brains

Zika virus (ZIKV) is a neurotropic flavivirus that causes several diseases including birth defects such as microcephaly. Intrinsic immunity is known to be a frontline defense against viruses through host anti-viral restriction factors. Limited knowledge is available on intrinsic immunity against ZIKV in brains. Amyloid precursor protein (APP) is predominantly expressed in brains and implicated in the pathogenesis of Alzheimer's diseases. We have found that ZIKV interacts with APP, and viral infection increases APP expression via enhancing protein stability. Moreover, we identified the viral peptide, HGSQHSGMIVNDTGHETDENRAKVEITPNSPRAEATLGGFGSLGL, which is capable of en-hancing APP expression. We observed that aging brain tissues with APP had protective effects on ZIKV infection by reducing the availability of the viruses. Also, knockdown of APP expression or blocking ZIKV-APP interactions enhanced ZIKV replication in human neural progenitor/stem cells. Finally, intracranial infection of ZIKV in APP-null neonatal mice resulted in higher mortality and viral yields. Taken together, these findings suggest that APP is a restriction factor that protects against ZIKV by serving as a decoy receptor, and plays a protective role in ZIKV-mediated brain injuries.

Subgingival Microbiota during Healthy Pregnancy and Pregnancy Gingivitis

INTRODUCTION

Previous studies have largely explored the microbial composition and pathogenesis of pregnancy gingivitis. However, the patterns of microbial colonization during pregnancy in the absence of pregnancy gingivitis have rarely been studied. Characterization of the oral microbiome in pregnant women with healthy gingiva is an important initial step in understanding the role of the microbiome in progression to pregnancy gingivitis.

OBJECTIVES

In this study, we compared the oral microbiome of pregnant women without gingivitis (healthy pregnancy) with pregnant women having gingivitis and nonpregnant healthy women to understand how pregnancy modifies the oral microbiome and induces progression to pregnancy gingivitis.

METHODS

Subgingival plaque samples were collected from Chinese pregnant women with gingivitis (n = 10), healthy pregnant women (n = 10), and nonpregnant healthy women (n = 10). The Illumina MiSeq platform was used to perform 16S rRNA gene sequencing targeting the V4 region.

RESULTS

The alpha and beta diversity was significantly different between pregnant and nonpregnant women, but minimal differences were observed between pregnant women with and without gingivitis. Interestingly, the oral bacterial community showed higher abundance of pathogenic taxa during healthy pregnancy as compared with nonpregnant women despite similar gingival and plaque index scores. However, when compared with overt pregnancy gingivitis, pathogenic taxa were less abundant during healthy pregnancy. PICRUSt analysis (phylogenetic investigation of communities by reconstruction of unobserved states) also suggested no difference in the functional capabilities of the microbiome during pregnancy, irrespective of gingival disease status. However, metabolic pathways related to amino acid metabolism were significantly increased in healthy pregnant women as compared with nonpregnant women.

CONCLUSION

The presence of pathogenic taxa in healthy pregnancy and pregnancy gingivitis suggests that bacteria may be necessary for initiating disease development but progression to gingivitis may be influenced by the host environmental factors. More efforts are required to plan interventions aimed at sustaining health before the appearance of overt gingivitis.

KNOWLEDGE TRANSFER STATEMENT

The results of this study draw attention to the importance of oral health maintenance during pregnancy, as women without any prenatal oral conditions are predisposed to the risk of developing pregnancy gingivitis. Hence, it is important to incorporate comprehensive assessment of oral health in the prenatal health care schedules. Pregnant woman should be screened for oral risks, counseled on proper oral hygiene and expected oral changes, and referred for dental treatment, when necessary.

Mouse model as an efficacy test for foot-and-mouth disease vaccines

Protection against foot-and-mouth disease virus (FMDV) has been linked to the development of a humoral response. In Argentina, the official control tests for assessing the potency of FMD vaccines are protection against podal generalization (PPG) and expected percentage of protection (EPP) curves built with quantitative data of antibodies determined by liquid-phase blocking ELISA (lpELISA). The results of these tests are used to accept or discard vaccines at the batch level. In this report, a mouse model was assessed as an alternative efficacy control for FMDV vaccines. To this aim, groups of cattle (n = 18) and BALB/c mice (n = 16) were inoculated with commercial FMDV vaccines and bleedings were performed 60 days post vaccination (dpv) in cattle and 21 dpv in mice. Specific FMDV antibody titres were measured in both species by a standardized lpELISA. A statistically significant association between antibody levels in cattle and mice has already been demonstrated. However, some vaccines have been misclassified since they were considered protective based on lpELISA results but did not induce good protection in cattle upon challenge. For this reason, other immunological parameters were evaluated to improve the prediction of protection in mice, without the need of using infective virus. In addition, antibody titres by lpELISA, the IgG2b/IgG1 isotype ratio and the Avidity Index were identified as good predictors, resulting in an optimal predictive model of protection. This mouse model could be a simple and economic alternative for testing FMD vaccines since the disadvantages of high costs and facility requirements associated with the use of large animals are overcome.

Chromatin regulation by Histone H4 acetylation at Lysine 16 during cell death and differentiation in the myeloid compartment

Histone H4 acetylation at Lysine 16 (H4K16ac) is a key epigenetic mark involved in gene regulation, DNA repair and chromatin remodeling, and though it is known to be essential for embryonic development, its role during adult life is still poorly understood. Here we show that this lysine is massively hyperacetylated in peripheral neutrophils. Genome-wide mapping of H4K16ac in terminally differentiated blood cells, along with functional experiments, supported a role for this histone post-translational modification in the regulation of cell differentiation and apoptosis in the hematopoietic system. Furthermore, in neutrophils, H4K16ac was enriched at specific DNA repeats. These DNA regions presented an accessible chromatin conformation and were associated with the cleavage sites that generate the 50 kb DNA fragments during the first stages of programmed cell death. Our results thus suggest that H4K16ac plays a dual role in myeloid cells as it not only regulates differentiation and apoptosis, but it also exhibits a non-canonical structural role in poising chromatin for cleavage at an early stage of neutrophil cell death.

Assessment of pesticides in soil from obsolete pesticides stores: a Caribbean case study

The fate of highly hazardous or persistent pesticides in soils and their potential for environmental and health risks depends on the physical and chemical properties of the pesticide, soil properties including biological health and climatic conditions. Assessing the fate and impact of pesticides in soil is complicated in the Caribbean due to the high diversity of soils and duality of climate. The FAO supported national competent authorities from 11 countries in the Caribbean in the assessment of obsolete stocks and potentially contaminated soil. The Environmental Management Tool Kit (EMKT) prioritised Fond Cole and Camden Base as the only critical sites. Preliminary site investigations that utilised the rapid environmental assessment (REA) methodology identified that contamination was restricted to an impervious layer at the Camden site. Pesticide properties varied across groups, with the organochlorides exhibiting greater sorptive capacity and lower leaching potential relative to the organophosphates. All tested soils were non-saline with alkaline pH and notably sandy in texture with low adsorptive capacity. Analysis of pesticide levels revealed low to undetected quantities across contaminated sites. Traces of Endrin and Dieldrin were found in Marienburg, Suriname. Overall, assessment of soil contamination from stored obsolete pesticides revealed minimal contamination, however, detailed assessment considering contamination gradients should be performed where pesticides were identified.

Epigenetic dysregulation of TET2 in human glioblastoma

Ten-eleven translocation (TET) enzymes are frequently deregulated in cancer, but the underlying molecular mechanisms are still poorly understood. Here we report that TET2 shows frequent epigenetic alterations in human glioblastoma including DNA hypermethylation and hypo-hydroxymethylation, as well as loss of histone acetylation. Ectopic overexpression of TET2 regulated neural differentiation in glioblastoma cell lines and impaired tumor growth. Our results suggest that epigenetic dysregulation of TET2 plays a role in human glioblastoma.

CXCR3+ Monocytes Increase Significantly in Graft Blood Compared to Peripheral Blood in Patients With Stable Kidney Graft Function

INTRODUCTION

We have recently reported that some lymphocyte populations do not maintain the same proportion in kidney graft blood as in peripheral blood, despite a stable function of the transplanted kidney. These results suggest that a comparative study between leukocyte cells from graft blood and those obtained from peripheral blood could provide information about the inflammatory state of the transplanted organ. In this work we selected the population of CD4+ lymphocytes and monocytes expressing CXCR3 to test this hypothesis.

MATERIAL AND METHODS

The study was performed by flow cytometry during month 3, 6, and 12 after transplantation in 58 patients who received an isolated kidney transplant and the same immunosuppressive regimen. The peripheral blood sample was obtained by venipuncture and the graft blood by fine needle aspiration.

RESULTS

We found a significant percentage decrease in CXCR3+ monocytes throughout the first year of transplantation in peripheral blood (15.9 ± 20.7 vs. 12.6 ± 12.4 vs. 6.3 ± 9.0, at 3, 6, and 12 months, respectively; P = .001), whereas the percentage of CXCR3+ monocytes in graft blood did not change over this period. This situation resulted in a significant percentage difference between the CXCR3+ monocytes from the graft blood and those from the peripheral blood at the sixth (15.8 ± 8.1 vs. 12.6 ± 12.4, respectively; P = .008) and 12th months (12.9 ± 8.1 vs. 6.3 ± 9.0, respectively; P < .001).

CONCLUSIONS

Therefore, we can conclude that the significant percentage increase of CXCR3+ monocytes in graft blood with respect to peripheral blood suggests the presence of inflammatory activity despite renal function being stable during the second half of the first year post-transplantation.

GSK2878175, a pan-genotypic non-nucleoside NS5B polymerase inhibitor, in healthy and treatment-naïve chronic hepatitis C subjects

GSK2878175 is a potent, pan-genotypic, non-nucleoside, nonstructural protein 5B palm polymerase inhibitor being developed for the treatment of chronic hepatitis C (CHC). A first-in-human, randomized, placebo-controlled, dose escalation study, evaluated the safety and pharmacokinetics of GSK2878175 administered as single and repeat oral doses (once daily for 14 days) to healthy volunteers. A separate proof-of-concept, placebo-controlled, repeat dose (once daily for 2 days) study evaluated the safety, pharmacokinetics and antiviral activity of GSK2878175 monotherapy in treatment-naïve, noncirrhotic, subjects with hepatitis C virus (HCV) genotype 1 [1a and 1b], 2, or 3. No deaths or SAEs were reported in either study, and treatment was well-tolerated. Across all the HCV genotypes, GSK2878175 monotherapy at doses of 10, 30 or 60 mg once daily for 2 days produced a statistically significant multilog reduction (P<.001) in plasma HCV RNA log₁₀ IU/mL from Baseline to 24, 48 and 72 hours after the first dose of GSK2878175 compared to placebo. The reduction in HCV RNA was sustained for a prolonged period across all of the active treatment groups, consistent with the long apparent half-life of GSK2878175 that was observed (mean t_1/2 range: 60-63 hours in the CHC subjects). In summary, GSK2878175, when administered to healthy subjects and subjects with CHC, did not reveal any safety concerns that would limit or preclude further clinical development. GSK2878175 monotherapy across a wide dose range produced substantial reduction in HCV RNA, irrespective of HCV genotype. The results from these studies support further evaluation of GSK2878175-based regimens.