Long-acting capsid inhibitor protects macaques from repeat SHIV challenges.

Because no currently available vaccine can prevent HIV infection, pre-exposure prophylaxis (PrEP) with antiretrovirals (ARVs) is an important tool for combating the HIV pandemic1,2. Long-acting ARVs promise to build on the success of current PrEP strategies, which must be taken daily, by reducing the frequency of administration3. GS-CA1 is a small-molecule HIV capsid inhibitor with picomolar antiviral potency against a broad array of HIV strains, including variants resistant to existing ARVs, and has shown long-acting therapeutic potential in a mouse model of HIV infection4. Here we show that a single subcutaneous administration of GS-CA1 provides long-term protection against repeated rectal simian-human immunodeficiency virus (SHIV) challenges in rhesus macaques. Whereas all control animals became infected after 15 weekly challenges, a single 300 mg kg-1 dose of GS-CA1 provided per-exposure infection risk reduction of 97% for 24 weeks. Pharmacokinetic analysis showed a correlation between GS-CA1 plasma concentration and protection from SHIV challenges. GS-CA1 levels greater than twice the rhesus plasma protein-adjusted 95% effective concentration conferred 100% protection in this model. These proof-of-concept data support the development of capsid inhibitors as a novel long-acting PrEP strategy in humans.

PyJAMAS: open-source, multimodal segmentation and analysis of microscopy images.

SUMMARY: Our increasing ability to resolve fine details using light microscopy is matched by an increasing need to quantify images in order to detect and measure phenotypes. Despite their central role in cell biology, many image analysis tools require a financial investment, are released as proprietary software, or are implemented in languages not friendly for beginners, and thus are used as black boxes. To overcome these limitations, we have developed PyJAMAS, an open-source tool for image processing and analysis written in Python. PyJAMAS provides a variety of segmentation tools, including watershed and machine learning-based methods; takes advantage of Jupyter notebooks for the display and reproducibility of data analyses; and can be used through a cross-platform graphical user interface or as part of Python scripts via a comprehensive application programming interface. AVAILABILITY AND IMPLEMENTATION: PyJAMAS is open-source and available at https://bitbucket.org/rfg_lab/pyjamas. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Resting-State Brain Temperature: Dynamic Fluctuations in Brain Temperature and the Brain-Body Temperature Gradient.

BACKGROUND: While fluctuations in healthy brain temperature have been investigated over time periods of weeks to months, dynamics over shorter time periods are less clear. PURPOSE: To identify physiological fluctuations in brain temperature in healthy volunteers over time scales of approximately 1 hour. STUDY TYPE: Prospective. SUBJECTS: A total of 30 healthy volunteers (15 female; 26 ± 4 years old). SEQUENCE AND FIELD STRENGTH: 3 T; T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and semi-localized by adiabatic selective refocusing (sLASER) single-voxel spectroscopy. ASSESSMENTS: Brain temperature was calculated from the chemical shift difference between N-acetylaspartate and water. To evaluate within-scan repeatability of brain temperature and the brain-body temperature difference, 128 spectral transients were divided into two sets of 64-spectra. Between-scan repeatability was evaluated using two time periods, ~1-1.5 hours apart. STATISTICAL TESTS: A hierarchical linear mixed model was used to calculate within-scan and between-scan correlations (Rw and Rb , respectively). Significance was determined at P ≤ .05. Values are reported as the mean ± standard deviation. RESULTS: A significant difference in brain temperature was observed between scans (-0.4 °C) but body temperature was stable (P = .59). Brain temperature (37.9 ± 0.7 °C) was higher than body temperature (36.5 ± 0.5 °C) for all but one subject. Within-scan correlation was high for brain temperature (Rw  = 0.95) and brain-body temperature differences (Rw  = 0.96). Between scans, variability was high for both brain temperature (Rb  = 0.30) and brain-body temperature differences (Rb  = 0.41). DATA CONCLUSION: Significant changes in brain temperature over time scales of ~1 hour were observed. High short-term repeatability suggests temperature changes appear to be due to physiology rather than measurement error. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Lenacapavir: A Novel, Potent, and Selective First-in-Class Inhibitor of HIV-1 Capsid Function Exhibits Optimal Pharmacokinetic Properties for a Long-Acting Injectable Antiretroviral Agent.

Lenacapavir (LEN) is a picomolar first-in-class capsid inhibitor of human immunodeficiency virus type 1 (HIV-1) with a multistage mechanism of action and no known cross resistance to other existing antiretroviral (ARV) drug classes. LEN exhibits a low aqueous solubility and exceptionally low systemic clearance following intravenous (IV) administration in nonclinical species and humans. LEN formulated in an aqueous suspension or a PEG/water solution formulation showed sustained plasma exposure levels with no unintended rapid drug release following subcutaneous (SC) administration to rats and dogs. A high total fraction dose release was observed with both formulations. The long-acting pharmacokinetics (PK) were recapitulated in humans following SC administration of both formulations. The SC PK profiles displayed two-phase absorption kinetics in both animals and humans with an initial fast-release absorption phase, followed by a slow-release absorption phase. Noncompartmental and compartmental analyses informed the LEN systemic input rate from the SC depot and exit rate from the body. Modeling-enabled deconvolution of the input rates from two processes: absorption of the soluble fraction (minor) from a direct fast-release process leading to the early PK phase and absorption of the precipitated fraction (major) from an indirect slow-release process leading to the later PK phase. LEN SC PK showed flip-flop kinetics due to the input rate being substantially slower than the systemic exit rate. LEN input rates via the slow-release process in humans were slower than those in both rats and dogs. Overall, the combination of high potency, exceptional stability, and optimal release rate from the injection depot make LEN well suited for a parenteral long-acting formulation that can be administered once up to every 6 months in humans for the prevention and treatment of HIV-1.

Letters of recommendation for gynecologic oncology fellowship differ by gender and race.

INTRODUCTION: Letters of recommendation (LOR) play a significant role in applicant selection for gynecologic oncology (GO) fellowship. LORs can be agentic, associated with competence, independence and strength, or communal, associated with being accommodating, cooperative and empathetic. Agentic LORs have been shown to reflect favorably on applicants, making them more likely to be selected for interview. The primary goal of this study was to determine linguistic differences in LORs for applicants applying to GO fellowship based on applicant gender and race. METHODS: All applications to a single academic institution from the years 2018-2020 were analyzed. LORs were extracted from all applicants who self-reported their gender and race/ethnicity. Analysis was performed using Linguistic Inquiry Word Count (LIWC) in terms of agentic and communal language. All analysis was done using SAS version 9.4. RESULTS: From 2018 to 2020, there were 239 GO fellowship applications to a single academic institution. There were 186 (78.1%) applicants who identified as female and 52 (21.8%) who identified as male. Female applicants were more likely to have more research (p = 0.047) and volunteer activities (p = 0.02) than male applicants. There were no differences between female and male applicants in terms of age, geographic location of residency, USMLE scores, AOA status, number of publications or attending a Doximitiy-rated top 20 residency program. There were 139 (60.7%) applicants who identified as White, 46 (20.1%) as Asian, 16 (7.0%) as Black, 19 (8.3%) as Latinx and 9 (3.9%) as other. On multivariable analysis, LORs written for male applicants had higher agentic scores compared to females (p < 0.05), and LORs of female applicants received higher communal scores (p < 0.05). LORs for applicants who identified as Black or Latinx were found to have lower agentic scores compared to individuals who identified as White(p < 0.05 for both). CONCLUSION: There were demonstrated linguistic differences in LOR for GO fellowship based on applicant gender and race/ethnicity. LORs written for white, male applicants were more likely to have higher agentic scores compared to minority, female applicants. LORs written for female applicants were more likely to have higher communal scores. As LORs have been shown to be instrumental in GO fellowship interview selection and linguistic differences exist based on applicant gender and race/ethnicity, this study highlights the need for a more objective GO fellowship application process. DISCLOSURES: Portion of this paper was presented at the Society for Gynecologic Oncology as part of a focus plenary.

Ledipasvir/Sofosbuvir Is Effective as Sole Treatment of Porphyria Cutanea Tarda with Chronic Hepatitis C.

BACKGROUND AND AIMS: Chronic hepatitis C [CHC] is a risk factor for porphyria cutanea tarda [PCT]. To assess whether ledipasvir/sofosbuvir is effective for treating both PCT and CHC, we treated patients with CHC + PCT solely with ledipasvir/sofosbuvir and followed them for at least 1 year to assess cure of CHC and remission of PCT. METHODS: Between September 2017 and May 2020, 15 of 23 screened PCT + CHC patients were eligible and enrolled. All were treated with ledipasvir/sofosbuvir at recommended doses and durations, according to their stage of liver disease. We measured plasma and urinary porphyrins at baseline and monthly for the first 12 months and at 16, 20, and 24 mos. We measured serum HCV RNA at baseline, 8-12, and 20-24 mos. Cure of HCV was defined as no detectable serum HCV RNA ≥ 12 weeks after the end of treatment (EOT). Remission of PCT was defined clinically as no new blisters or bullae and biochemically as urinary uro- plus hepta-carboxyl porphyrins ≤ 100 mcg/g creatinine. RESULTS: All 15 patients, 13 of whom were men, were infected with HCV genotype 1. 2/15 withdrew or were lost to follow-up. Of the remaining 13, 12 achieved cure of CHC; 1 had complete virological response, followed by relapse of HCV after ledipasvir/sofosbuvir but was subsequently cured by treatment with sofosbuvir/velpatasvir. Of the 12 cured of CHC, all achieved sustained clinical remission of PCT. CONCLUSIONS: Ledipasvir/sofosbuvir [and likely other direct-acting antivirals] is an effective treatment for HCV in the presence of PCT and leads to clinical remission of PCT without additional phlebotomy or low-dose hydroxychloroquine treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT03118674.

Abortion restrictions and medical residency applications.

Residency selection is a challenging process for medical students, one further complicated in the USA by the recent Dobbs v Jackson Women's Health Organization (Dobbs) decision over-ruling the federal right to abortion. We surveyed medical students to examine how Dobbs is influencing the ideological, personal and professional factors they must reconcile when choosing where and how to complete residency.Between 6 August and 22 October 2022, third-year and fourth-year US medical students applying to US residency programmes were surveyed through social media and direct outreach to medical schools. Analysis of quantitative and qualitative data from 494 responses was performed to assess downstream effects of Dobbs on residency applicants' family, health and career choices.Most respondents said changes in abortion access would likely or very likely influence their decision regarding location of considered residency programme (76.9%), where to start a family (72.2%) and contraceptive planning for them or their partner (57.9%). Cis-gender females were more influenced by Dobbs regarding where (5 (4, 5) p<0.001) and when (3 (3, 5) p<0.001) to start a family. In qualitative responses, medical trainees highlighted the importance of abortion access for their patients, themselves and their loved ones.Medical trainees are incorporating state abortion access into their residency programme choices. Future physicians care about both the quality of care they will be able to provide and their own health. For personal and professional reasons, reproductive healthcare access is now a key factor in residency match decisions.

Lexical inferencing as a generation effect for foreign language vocabulary learning.

Prior research suggests that second language (L2) vocabulary learning often occurs through lexical inferencing (translations based on context), but there has been less emphasis on how lexical inferencing compares with other methods of L2 word learning. The present study compared lexical inferencing to simply studying word lists for L2 learning. A secondary goal was to determine whether any effect of inferencing is mediated by the generation effect of memory, a phenomenon wherein generated information (inferencing) is remembered better than obtained information (reading). Across four experiments, participants read English sentences with embedded Swahili words and were asked either to infer the word meaning using context or were provided with translations before reading the sentence (reading condition). In contrast to our initial hypotheses, the inference condition resulted in lower rates of retention compared with the reading condition. In addition, the data suggest a number of differences between lexical inferencing and the generation effect, that argue against the proposal that lexical inferencing operates as a type of generation effect.

Is Increasing Parity Associated with Adverse Perinatal Outcomes in Dichorionic Twin Gestations?

OBJECTIVE: Dichorionic twins have increased risk of preterm birth and hypertensive disorders of pregnancy. Grand multiparity may be associated with adverse perinatal outcomes in singleton pregnancies, although the effect of increasing parity in twins is unclear. This study aimed to elucidate whether grand multiparity leads to adverse outcomes in dichorionic twins compared with multiparity and nulliparity. STUDY DESIGN: This was a retrospective review of dichorionic twins at a single institution between January 2008 and December 2019 comparing pregnancy outcomes among grand multiparity, multiparity, and nulliparity. Primary outcome was preterm birth less than 37 weeks. Multivariable regression controlled for differing demographics, prior preterm birth, use of reproductive technologies, and hypertensive disorders of pregnancy. Chi square and Fisher's exact were used for categorical variables and Kruskal-Wallis was used for continuous variables. RESULTS: A total of 843 (60.3%) pregnancies were nulliparous, 499 (35.7%) multiparous, and 57(4.1%) grand multiparous. Univariate analysis indicated that multiparous women had lower incidence of preterm birth less than 37, 34, and 32 weeks (57 vs. 51%, p = 0.04; 19.2 vs. 14.0%, p = 0.02; 9.6 vs. 5.6%, p = 0.01) and that grand multiparous women had lower incidence of preterm birth less than 34 weeks (19.2 vs. 5.3%, p = 0.008) compared with nulliparous women. Multivariable regression confirmed multiparous women had lower odds of preterm birth less than 34 and 32 weeks compared with nulliparous women (<34 wk: odds ratio [OR] = 0.69, 95% confidence interval [CI] = 0.49-0.97, p = 0.03; <32 wk: OR = 0.48, 95% CI = 0.29-0.79, p = 0.004) and that multiparous women (OR = 0.57, 95% CI = 0.42-0.77, p = 0.0002) and grand multiparous women (OR = 0.23, 95% CI = 0.08-0.68, p = 0.0074) had lower incidence of hypertensive disorders of pregnancy when compared with nulliparous women. CONCLUSION: Grand multiparity is not associated with adverse perinatal outcomes compared with nulliparity or multiparity in dichorionic twins. Increasing parity may protect against incidence of preterm birth and hypertensive disorders of pregnancy even among grand multiparous women. KEY POINTS: · Incidence of preterm birth may decrease with increasing parity in twins.. · Hypertensive disorders of pregnancy may decrease with increasing parity in twins.. · Grand multiparity is not associated with adverse perinatal outcomes in twins..

Novel Endoscopic Polypectomy Surveillance Technique for Fundic Gland Polyps in Familial Adenomatous Polyposis Can Improve Early Detection of Dysplasia and Gastric Cancer.

INTRODUCTION: Fundic gland polyps (FGPs) are commonly found in patients with familial adenomatous polyposis (FAP) and are considered benign. Biopsies are not routinely performed, and conventional forceps may be time-consuming and/or yield nonrepresentative histology. The purpose of this study was to evaluate the role of a novel endoscopic polypectomy surveillance (EPS), a large volume cold-snare polypectomy technique of random FGPs, in the incidence of dysplasia and gastric cancer (GC) in FAP. METHODS: This is a retrospective longitudinal cohort of patients with FAP referred to a tertiary care center for duodenal adenoma surveillance and who underwent EPS of FGPs between 2001 and 2019. Demographic, endoscopic, and clinicopathologic information was reviewed. RESULTS: Thirty-five patients with FAP were identified at initial endoscopy by the mean age of 43.4 years (±12.8). One hundred thirteen surveillance endoscopies were performed in total using EPS. Dysplasia of FGPs was present on initial esophagogastroduodenoscopy in 7 patients (20%), and 13 additional patients (46.4%) progressed to low-grade dysplasia. Three patients (15%) who subsequently had progression to GC were found to have signet ring cell cancer within the foci of FGPs through EPS. One patient presented as metastatic GC. Progression from nondysplastic FGP to low-grade dysplasia occurred over 63 months (±46.3) with further progression to GC over 34 months (±8.5). Endoscopic risk factors for cancer were polyps >10 mm in size ( P < 0.001) and carpeting of polyps ( P < 0.001). The 5-year cumulative incidence of developing dysplasia was 35.7%. DISCUSSION: We identified that the incidence of dysplasia and GC is higher than previously reported in patients with FAP. Our study used a novel EPS technique and was able to identify GC within the foci of FGPs. Upper endoscopic guidelines should include a more rigorous sampling method for FGPs, such as EPS, to optimize early detection of dysplasia and GC.

Identification and characterization of pleiotropic and epistatic QDRL conferring partial resistance to Pythium irregulare and P. sylvaticum in soybean.

KEY MESSAGE: Pleiotropic and epistatic quantitative disease resistance loci (QDRL) were identified for soybean partial resistance to different isolates of Pythium irregulare and Pythium sylvaticum. Pythium root rot is an important seedling disease of soybean [Glycine max (L.) Merr.], a crop grown worldwide for protein and oil content. Pythium irregulare and P. sylvaticum are two of the most prevalent and aggressive Pythium species in soybean producing regions in the North Central U.S. Few studies have been conducted to identify soybean resistance for management against these two pathogens. In this study, a mapping population (derived from E13390 x E13901) with 228 F4:5 recombinant inbred lines were screened against P. irregulare isolate MISO 11-6 and P. sylvaticum isolate C-MISO2-2-30 for QDRL mapping. Correlation analysis indicated significant positive correlations between soybean responses to the two pathogens, and a pleiotropic QDRL (qPirr16.1) was identified. Further investigation found that the qPirr16.1 imparts dominant resistance against P. irregulare, but recessive resistance against P. sylvaticum. In addition, two QDRL, qPsyl15.1, and qPsyl18.1 were identified for partial resistance to P. sylvaticum. Further analysis revealed epistatic interactions between qPirr16.1 and qPsyl15.1 for RRW and DRX, whereas qPsyl18.1 contributed resistance to RSE. Marker-assisted resistance spectrum analysis using F6:7 progeny lines verified the resistance of qPirr16.1 against four additional P. irregulare isolates. Intriguingly, although the epistatic interaction of qPirr16.1 and qPsyl15.1 can be confirmed using two additional isolates of P. sylvaticum, the interaction appears to be suppressed for the other two P. sylvaticum isolates. An 'epistatic gene-for-gene' model was proposed to explain the isolate-specific epistatic interactions. The integration of the QDRL into elite soybean lines containing all the desirable alleles has been initiated.

Endoscopic Mucosal Resection in Children.

OBJECTIVES: Endoscopic mucosal resection (EMR) for removal of large polyps is well established in adults. EMR technique in the pediatric population is less utilized due to lower incidence of large intestinal polyps in pediatric patients and limited EMR training for pediatric gastroenterologists. The aim of this study is to retrospectively review safety and efficacy of pediatric EMR cases at two large, tertiary referral centers with adult and pediatric EMR expertise. METHODS: A retrospective chart review was conducted at Cedars-Sinai Medical Center and Cincinnati Children's Hospital Medical Center from January 2012 to May 2021. Demographic, clinical, technical and follow up data were collected for patients <18 years of age who underwent EMR during the study period. RESULTS: Fifteen pediatric EMR procedures were identified in 11 patients (five male, six female) during the study period. Indication was most frequently rectal bleeding. Polyp size removed ranged from 9 to 60 mm and pathology was consistent with juvenile inflammatory polyps in six patients. Technical success was achieved in 14 of 15 (93%) of EMRs with clinical success (desired clinical outcome) in all 13 procedures with clinical follow-up. There were no adverse events. CONCLUSIONS: This study identifies a case series of pediatric patients who underwent EMR at two tertiary care centers. This series demonstrates successful EMR in children and shows a high technical and clinical success rate with a low complication rate. More investigation into EMR in pediatric patients is necessary, and its use should be isolated to centers with endoscopists with specific experience in EMR techniques.

Human and nonclinical disposition of [14C]bictegravir, a potent integrase strand-transfer inhibitor for the treatment of HIV-1 infection.

Bictegravir (BIC) is a potent small-molecule integrase strand-transfer inhibitor (INSTI) and a component of Biktarvy®, a single-tablet combination regimen that is currently approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. The absorption, metabolism, distribution, and elimination (ADME) characteristics of BIC were determined through in vivo nonclinical and clinical studies (IND 121318).[14C]BIC was rapidly absorbed orally in mice, rats, monkeys and human. The cumulative dose recovery was high in nonclinical species (>80%) and humans (95.3%), with most of the excreted dose recovered in faeces. Quantifiable radioactivity with declining concentration was observed in rat tissues suggesting reversible binding. Unchanged BIC was the most abundant circulating component in all species along with two notable metabolites M20 (a sulphate conjugate of hydroxylated BIC) and M15 (a glucuronide conjugate of BIC). BIC was primarily eliminated by hepatic metabolism followed by excretion of the biotransformed products into faeces. In vitro drug-drug interaction (DDI) studies with M15 and M20 demonstrated that no clinically relevant interactions were expected.Overall, BIC is a novel and potent INSTI with a favourable resistance, PK, and ADME profile that provides important improvements over other currently available INSTIs for the treatment of HIV-1.

Human pharmacokinetics prediction with an in vitro-in vivo correction factor approach and in vitro drug-drug interaction profile of bictegravir, a potent integrase-strand transfer inhibitor component in approved biktarvy® for the treatment of HIV-1 infection.

Bictegravir (BIC) is a potent small-molecule integrase strand-transfer inhibitor (INSTI) and a component of Biktarvy®, a single-tablet combination regimen that is currently approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. The in vitro properties, pharmacokinetics (PK), and drug-drug interaction (DDI) profile of BIC were characterised in vitro and in vivo.BIC is a weakly acidic, ionisable, lipophilic, highly plasma protein-bound BCS class 2 molecule, which makes it difficult to predict human PK using standard methods. Its systemic plasma clearance is low, and the volume of distribution is approximately the volume of extracellular water in nonclinical species. BIC metabolism is predominantly mediated by cytochrome P450 enzyme (CYP) 3A and UDP-glucuronosyltransferase 1A1. BIC shows a low potential to perpetrate clinically meaningful DDIs via known drug metabolising enzymes or transporters.The human PK of BIC was predicted using a combination of bioavailability and volume of distribution scaled from nonclinical species and a modified in vitro-in vivo correlation (IVIVC) correction for clearance. Phase 1 studies in healthy subjects largely bore out the prediction and supported the methods used. The approach presented herein could be useful for other drug molecules where standard projections are not sufficiently accurate. .

Efficacy and patient satisfaction of single-session transoral incisionless fundoplication and laparoscopic hernia repair.

BACKGROUND AND AIMS: Transoral incisionless fundoplication (TIF) is an effective endoscopic treatment for refractory GERD with small or absent hiatal hernia (< 2 cm in length and width). The single-session laparoscopic hernia repair followed by transoral incisionless fundoplication (HH + TIF) aims to repair mechanical defects in the lower esophageal sphincter that leads to GERD in patients with hiatal hernias ≥ 2 cm. The procedure effectively treats GERD without causing added post-surgical dysphagia and gas bloating commonly associated with partial laparoscopic fundoplication. We aimed to assess patient satisfaction, symptom resolution, safety, and proton pump inhibitor use following the HH + TIF procedure. METHODS: Thirty-three patients underwent single-session laparoscopic hernia repair with intraoperative TIF using the EsophyX Z device (EndoGastric Solutions, Inc.) between June 2015 and June 2018. The presence of GERD and normal esophageal motility were confirmed with pH testing and manometry prior to the procedure. Data were collected on pre- and post-procedure symptoms, patient satisfaction, PPI use, and complications. Median post-procedure follow-up with symptom surveys was 9 months (11-29 months). RESULTS: Patients reported significant decreases in common GERD symptoms including heartburn, regurgitation, cough, and hoarse voice. Eighty-one percent (27/33) of patients were off daily PPIs. Ninety-four percent (31/33) of patients reported 75% or greater satisfaction with the procedure and outcomes. One patient had a superficial mucosal laceration after the procedure, likely due to vomiting, which was treated conservatively. CONCLUSIONS: The majority of patients reported 75% or greater satisfaction with the procedure and had an improvement in GERD symptoms as well as decreased PPI use. There were no serious adverse events.

In Vitro Hepatic Uptake in Human and Monkey Hepatocytes in the Presence and Absence of Serum Protein and Its In Vitro to In Vivo Extrapolation.

It is well documented that human hepatic clearance based on in vitro metabolism or transporter assays systematically resulted in underprediction; therefore, large empirical scalars are often needed in either static or physiologically based pharmacokinetic (PBPK) models to accurately predict human pharmacokinetics (PK). In our current investigation, we assessed hepatic uptake in hepatocyte suspension in Krebs-Henseleit buffer in the presence and absence of serum. The results showed that the unbound intrinsic active clearance (CLu,int,active) values obtained by normalizing the unbound fraction in the buffer containing 10% serum were generally higher than the CLu,int,active obtained directly from protein free buffer, suggesting "protein-facilitated" uptake. The differences of CLu,int,active in the buffer with and without protein ranged from 1- to 925-fold and negatively correlated to the unbound serum binding of organic anion transporting polypeptide substrates. When using the uptake values obtained from buffer containing serum versus serum-free buffer, the median of scaling factors (SFs) for CLu,int,active reduced from 24.2-4.6 to 22.7-7.1 for human and monkey, respectively, demonstrating the improvement of in vitro to in vivo extrapolation in a PBPK model. Furthermore, values of CLu,int,active were significantly higher in monkey hepatocytes than that in human, and the species differences appeared to be compound dependent. Scaling up in vitro uptake values derived in assays containing species-specific serum can compensate for the species-specific variabilities when using cynomolgus monkey as a probe animal model. Incorporating SFs calibrated in monkey and together with scaled in vitro data can be a reliable approach for the prospective human PK prediction in early drug discovery. SIGNIFICANCE STATEMENT: We investigated the protein effect on hepatic uptake in human and monkey hepatocytes and improved the in vitro to in vivo extrapolation using parameters obtained from the incubation in the present of serum protein. In addition, significantly higher active uptake clearances were observed in monkey hepatocytes than in human, and the species differences appeared to be compound dependent. The physiologically based pharmacokinetic model that incorporates scaling factors calibrated in monkey and together with scaled in vitro human data can be a reliable approach for the prospective human pharmacokinetics prediction.

Discovery of velpatasvir (GS-5816): A potent pan-genotypic HCV NS5A inhibitor in the single-tablet regimens Vosevi® and Epclusa®.

Direct-acting antiviral inhibitors have revolutionized the treatment of hepatitis C virus (HCV) infected patients. Herein is described the discovery of velpatasvir (VEL, GS-5816), a potent pan-genotypic HCV NS5A inhibitor that is a component of the only approved pan-genotypic single-tablet regimens (STRs) for the cure of HCV infection. VEL combined with sofosbuvir (SOF) is Epclusa®, an STR with 98% cure-rates for genotype 1-6 HCV infected patients. Addition of the pan-genotypic HCV NS3/4A protease inhibitor voxilaprevir to SOF/VEL is the STR Vosevi®, which affords 97% cure-rates for genotype 1-6 HCV patients who have previously failed another treatment regimen.

Discovery of the pan-genotypic hepatitis C virus NS3/4A protease inhibitor voxilaprevir (GS-9857): A component of Vosevi®.

Treatment of hepatitis C virus (HCV) infection has been historically challenging due the high viral genetic complexity wherein there are eight distinct genotypes and at least 86 viral subtypes. While HCV NS3/4A protease inhibitors are an established treatment option for genotype 1 infection, limited coverage of genotypes 2 and/or 3 combined with serum alanine transaminase (ALT) elevations for some compounds has limited the broad utility of this therapeutic class. Our discovery efforts were focused on identifying an NS3/4A protease inhibitor with pan-genotypic antiviral activity, improved coverage of resistance associated substitutions, and a decreased risk of hepatotoxicity. Towards this goal, distinct interactions with the conserved catalytic triad of the NS3/4A protease were identified that improved genotype 3 antiviral activity. We further discovered that protein adduct formation strongly correlated with clinical ALT elevation for this therapeutic class. Improving metabolic stability and decreasing protein adduct formation through structural modifications ultimately resulted in voxilaprevir. Voxilaprevir, in combination with sofosbuvir and velpatasvir, has demonstrated pan-genotypic antiviral clinical activity. Furthermore, hepatotoxicity was not observed in Phase 3 clinical trials with voxilaprevir, consistent with our design strategy. Vosevi® (sofosbuvir, velpatasvir, and voxilaprevir) is now an approved pan-genotypic treatment option for the most difficult-to-cure individuals who have previously failed direct acting antiviral therapy.

Pressure-Enabled Synthesis of Hetero-Dimers and Hetero-Rods through Intraparticle Coalescence and Interparticle Fusion of Quantum-Dot-Au Satellite Nanocrystals.

This report presents the fabrication and pressure-driven processing of heterostructural nanocrystal superlattices (HNC-SLs) self-assembled from quantum-dot-Au (QD-Au) satellite-type HNCs. In situ small/wide-angle X-ray scattering and electron microscopic measurements showed that the HNC-SLs underwent structural transformation at both atomic- and mesoscales during the pressure processing. Upon deviatoric stress-driven orientational migration, the intraparticle coalescence of Au satellites at QD surfaces transforms individual HNCs into heterodimers, whereas the interparticle fusion drives assembled HNCs into ordered heterorod arrays. These results demonstrate high-pressure-processing as a clean and fast means for conversion of HNCs into novel heteromaterials that are difficult to achieve through conventional synthetic routes.

Visual Abstract of "Six Tips for Giving Good Health Care to Anyone With a Cervix".

This visual abstract is based on an article from the February 2020 issue of the journal.