Forward genetics combined with unsupervised classifications identified zebrafish mutants affecting biliary system formation.

Impaired formation of the biliary network can lead to congenital cholestatic liver diseases; however, the genes responsible for proper biliary system formation and maintenance have not been fully identified. Combining computational network structure analysis algorithms with a zebrafish forward genetic screen, we identified 24 new zebrafish mutants that display impaired intrahepatic biliary network formation. Complementation tests suggested these 24 mutations affect 24 different genes. We applied unsupervised clustering algorithms to unbiasedly classify the recovered mutants into three classes. Further computational analysis revealed that each of the recovered mutations in these three classes has a unique phenotype on node-subtype composition and distribution within the intrahepatic biliary network. In addition, we found most of the recovered mutations are viable. In those mutant fish, which are already good animal models to study chronic cholestatic liver diseases, the biliary network phenotypes persist into adulthood. Altogether, this study provides unique genetic and computational toolsets that advance our understanding of the molecular pathways leading to biliary system malformation and cholestatic liver diseases.

A phenome-wide association study identifies effects of copy-number variation of VNTRs and multicopy genes on multiple human traits.

The human genome contains tens of thousands of large tandem repeats and hundreds of genes that show common and highly variable copy-number changes. Due to their large size and repetitive nature, these variable number tandem repeats (VNTRs) and multicopy genes are generally recalcitrant to standard genotyping approaches and, as a result, this class of variation is poorly characterized. However, several recent studies have demonstrated that copy-number variation of VNTRs can modify local gene expression, epigenetics, and human traits, indicating that many have a functional role. Here, using read depth from whole-genome sequencing to profile copy number, we report results of a phenome-wide association study (PheWAS) of VNTRs and multicopy genes in a discovery cohort of ∼35,000 samples, identifying 32 traits associated with copy number of 38 VNTRs and multicopy genes at 1% FDR. We replicated many of these signals in an independent cohort and observed that VNTRs showing trait associations were significantly enriched for expression QTLs with nearby genes, providing strong support for our results. Fine-mapping studies indicated that in the majority (∼90%) of cases, the VNTRs and multicopy genes we identified represent the causal variants underlying the observed associations. Furthermore, several lie in regions where prior SNV-based GWASs have failed to identify any significant associations with these traits. Our study indicates that copy number of VNTRs and multicopy genes contributes to diverse human traits and suggests that complex structural variants potentially explain some of the so-called "missing heritability" of SNV-based GWASs.

SARS-CoV-2 Antiviral Prescribing Gaps Among Nonhospitalized High-Risk Adults.

Within a multistate clinical cohort, SARS-CoV-2 antiviral prescribing patterns were evaluated from April 2022-June 2023 among nonhospitalized patients with SARS-CoV-2 with risk factors for severe COVID-19. Among 3247 adults, only 31.9% were prescribed an antiviral agent (87.6% nirmatrelvir/ritonavir, 11.9% molnupiravir, 0.5% remdesivir), highlighting the need to identify and address treatment barriers.

Origin of Octafluorocyclopentene Polyelectrophilicity.

Octafluorocyclopentene (OFCP) has found utility as a polyelectrophile in substitution cascades that form complex macrocyclic compounds. The Harran group synthesis of macrocyclic polypeptides depends on OFCP as a linker, combining with four different nucleophilic units of a polypeptide. We report a computational investigation of the origins of OFCP reactivity and a rationale for controlled mono-, di-, tri-, and tetrasubstitution of fluoride ions by heteroatomic nucleophiles. The roles of inductive, negative hyperconjugative, and resonance electron-donation by fluoride substituents are explored for the reaction of OFCP, less-fluorinated analogues, and common electrophilic alkenes with several different nucleophiles.

Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA.

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

Future directions in acute liver failure.

Acute liver failure (ALF) describes a clinical syndrome of rapid hepatocyte injury leading to liver failure manifested by coagulopathy and encephalopathy in the absence of pre-existing cirrhosis. The hallmark diagnostic features are a prolonged prothrombin time (ie, an international normalized ratio of prothrombin time of ≥1.5) and any degree of mental status alteration (HE). As a rare, orphan disease, it seemed an obvious target for a multicenter network. The Acute Liver Failure Study Group (ALFSG) began in 1997 to more thoroughly study and understand the causes, natural history, and management of ALF. Over the course of 22 years, 3364 adult patients were enrolled in the study registry (2614 ALF and 857 acute liver injury-international normalized ratio 2.0 but no encephalopathy-ALI) and >150,000 biosamples collected, including serum, plasma, urine, DNA, and liver tissue. Within the Registry study sites, 4 prospective substudies were conducted and published, 2 interventional ( N -acetylcysteine and ornithine phenylacetate), 1 prognostic [ 13 C-methacetin breath test (MBT)], and 1 mechanistic (rotational thromboelastometry). To review ALFSG's accomplishments and consider next steps, a 2-day in-person conference was held at UT Southwestern Medical Center, Dallas, TX, entitled "Acute Liver Failure: Science and Practice," in May 2022. To summarize the important findings in the field, this review highlights the current state of understanding of ALF and, more importantly, asks what further studies are needed to improve our understanding of the pathogenesis, natural history, and management of this unique and dramatic condition.

The chemokine CXCL14 is a novel early prognostic biomarker for poor outcome in acetaminophen-induced acute liver failure.

BACKGROUND AND AIMS: Patients with acetaminophen-induced acute liver failure are more likely to die while on the liver transplant waiting list than those with other causes of acute liver failure. Therefore, there is an urgent need for prognostic biomarkers that can predict the need for liver transplantation early after an acetaminophen overdose. APPROACH AND RESULTS: We evaluated the prognostic potential of plasma chemokine C-X-C motif ligand 14 (CXCL14) concentrations in patients with acetaminophen (APAP) overdose (n=50) and found that CXCL14 is significantly higher in nonsurviving patients compared to survivors with acute liver failure ( p < 0.001). Logistic regression and AUROC analyses revealed that CXCL14 outperformed the MELD score, better discriminating between nonsurvivors and survivors. We validated these data in a separate cohort of samples obtained from the Acute Liver Failure Study Group (n = 80), where MELD and CXCL14 had similar AUC (0.778), but CXCL14 demonstrated higher specificity (81.2 vs. 52.6) and positive predictive value (82.4 vs. 65.4) for death or need for liver transplantation. Next, combining the patient cohorts and using a machine learning training/testing scheme to mimic the clinical scenario, we found that CXCL14 outperformed MELD based on AUC (0.821 vs. 0.787); however, combining MELD and CXCL14 yielded the best AUC (0.860). CONCLUSIONS: We find in 2 independent cohorts of acetaminophen overdose patients that circulating CXCL14 concentration is a novel early prognostic biomarker for poor outcomes, which may aid in guiding decisions regarding patient management. Moreover, our findings reveal that CXCL14 performs best when measured soon after patient presentation to the clinic, highlighting its importance for early warning of poor prognosis.

Use of HBV RNA and to predict change in serological status and disease activity in CHB.

BACKGROUND AND AIMS: Predicting changes in disease activity and serological endpoints is necessary for the management of patients with chronic hepatitis B (CHB). We examined whether HBV RNA and hepatitis B core-related antigen (HBcrAg), two specialized virological markers proposed to reflect the activity of covalently closed circular DNA, may improve the ability to predict not sustained inactive carrier phase, spontaneous alanine aminotransferase (ALT) flare, HBeAg loss, and HBsAg loss. APPROACH AND RESULTS: Among eligible participants enrolled in the North American Hepatitis B Research Network Adult Cohort Study, we evaluated demographic, clinical, and virologic characteristics, including HBV RNA and HBcrAg, to predict not sustained inactive carrier phase, ALT flare, HBeAg loss, and HBsAg loss through a series of Cox proportional hazard or logistic regression models, controlling for antiviral therapy use. Among the study population, 54/103 participants experienced not sustained inactive carrier phase, 41/1006 had a spontaneous ALT flare, 83/250 lost HBeAg, and 54/1127 lost HBsAg. HBV RNA or HBcrAg were predictive of all 4 events. However, their addition to models of the readily available host (age, sex, race/ethnicity), clinical (ALT, use of antiviral therapy), and viral factors (HBV DNA), which had acceptable-excellent accuracy (e.g., AUC = 0.72 for ALT flare, 0.92 for HBeAg loss, and 0.91 for HBsAg loss), provided only small improvements in predictive ability. CONCLUSION: Given the high predictive ability of readily available markers, HBcrAg and HBV RNA have a limited role in improving the prediction of key serologic and clinical events in patients with CHB.

Positive thinking about negative studies.

The non-reporting of negative studies results in a scientific record that is incomplete, one-sided and misleading. The consequences of this range from inappropriate initiation of further studies that might put participants at unnecessary risk to treatment guidelines that may be in error, thus compromising day-to-day clinical practice.

Protecting and promoting editorial independence.

We argue that editorial independence, through robust practice of publication ethics and research integrity, promotes good science and prevents bad science. We elucidate the concept of research integrity, and then discuss the dimensions of editorial independence. Best practice guidelines exist, but compliance with these guidelines varies. Therefore, we make recommendations for protecting and strengthening editorial independence.

Macrophage activation markers are associated with infection and mortality in patients with acute liver failure.

BACKGROUND AND AIMS: Acute liver failure is a multisystem disorder with a high mortality and frequent need for emergency liver transplantation. Following massive innate immune system activation, soluble markers of macrophage activation are released during liver damage and their association with disease severity and prognosis requires exploration. METHODS: Patients ALF from the United States Acute Liver Failure Study Group (USALFSG, n = 224) and King's College Hospital (n = 40) together with healthy controls (HC, n = 50) were recruited. Serum from early (Days 1-3) and late (>Day 3) time points were analysed for MAMs by enzyme-linked immunosorbent assay correlated to markers of illness severity and 21-day spontaneous survival. Surface expression phenotyping was performed via Flow Cytometry on CD14+ monocytes. RESULTS: All MAMs serum concentrations were significantly higher in ALF compared to controls (p < .0001). sCD206 concentration was higher in early and late stages of the disease in patients with bacteraemia (p = .002) and infection in general (p = .006). In MELD-adjusted multivariate modelling, sCD206 and sCD163 were independently associated with mortality. CD14+ monocyte expression of CD206 (p < .001) was higher in patients with ALF compared with controls and correlated with SOFA score (p = .018). sCD206 was independently validated as a predictor of infection in an external cohort. CONCLUSIONS: sCD206 is increased in serum of ALF patients with infections and poor outcome and is upregulated on CD14+ monocytes. Later measurements of sCD163 and sCD206 during the evolution of ALF have potential as mechanistic predictors of mortality. sCD206 should be explored as a biomarker of sepsis and mortality in ALF.

Clinical Characteristics of Avoidable Patient Transfers for Suspected Pediatric Appendicitis.

INTRODUCTION: Pediatric surgical care is becoming increasingly regionalized, often resulting in limited access. Interfacility transfers pose a significant financial and emotional burden to when they are potentially avoidable. Of transferred patients, we sought to identify clinical factors associated with avoidable transfers in pediatric patients with suspected appendicitis. METHODS: We performed a single-center retrospective study at an academic tertiary referral children's hospital in an urban setting. We included children who underwent interfacility transfer to our center with a transfer diagnosis of appendicitis from July 1, 2021 to June 30, 2023. Encounters were designated as either an appropriate transfer (underwent appendectomy) or an avoidable transfer (did not undergo appendectomy). Encounters treated nonoperatively for complicated appendicitis were excluded. Bivariate analysis was performed using Mann-Whitney test and chi-square tests. RESULTS: A total of 444 patients were included: 71.2% were classified as appropriate transfers and 28.8% as avoidable transfers. Patients with avoidable transfer were younger compared to those in the appropriate transfer cohort (median age 9 y, interquartile range: 7-13 versus 11 y, interquartile range: 8-14; P < 0.001). Avoidable transfers less frequently presented with the typical symptoms of fever, migratory abdominal pain, anorexia, and nausea/emesis (P = 0.005). Avoidable transfers also reported shorter symptom duration (P = 0.040) with lower median white blood cell count (P < 0.001), neutrophil percentage (P < 0.001), and C-reactive protein levels (P < 0.003). Avoidable transfers more frequently underwent repeat imaging upon arrival (42.9% versus 12.7%, P < 0.001). CONCLUSIONS: These findings highlight the importance of clinical history in children with suspected appendicitis. Younger patients without typical symptoms of appendicitis, those with a shorter duration of symptoms, and lower serum inflammatory markers may benefit from close observation without transfer.

Differential RNA Expression Between Metastatic and Primary Neuroblastoma Cells.

INTRODUCTION: Neuroblastoma (NB) is the most common extra-cranial malignancy in children. Poor survival in high-risk NB is attributed to recurrent metastatic disease. To better study metastatic disease, we used a novel mouse model to investigate differential gene expression between primary tumor cells and metastatic cells. We hypothesized that metastatic NB cells have a different gene expression profile from primary tumor cells and cultured cells. METHODS: Using three human NB cell lines (NGP, CHLA255, and SH-SY5Y), orthotopic xenografts were established in immunodeficient nod/scid gamma mice via subcapsular renal injection. Mice were sacrificed and NB cells were isolated from the primary tumor and from sites of metastasis (bone marrow, liver). RNA sequencing, gene set analysis, and pathway analysis were performed to identify differentially expressed genes and molecular pathways in the metastatic cells compared to primary tumor cells. RESULTS: There were 266 differentially expressed genes in metastatic tumor cells (bone marrow and liver combined) compared to primary tumor cells. The top upregulated gene was KCNK1 and the top downregulated genes were PDE7B and NEBL. Top upregulated pathways in the metastatic cells were involved in ion transport, cell signaling, and cell proliferation. Top downregulated pathways were involved in DNA synthesis, transcription, and cellular metabolism. CONCLUSIONS: In metastatic NB cells, our study identified the upregulation of biologic processes involved in cell cycle regulation, cell proliferation, migration, and invasion. Ongoing studies aim to validate downstream translation of these genomic alterations, as well as target these pathways to more effectively suppress and inhibit recurrent metastatic disease in NB.

Low HBV knowledge is associated with low HBV vaccination uptake in general adult population despite incentivization of HBV vaccination.

BACKGROUND: Hepatitis B virus (HBV) vaccination in Vietnamese adults remains low and unequally distributed. We conducted a study on HBV-naïve adults living in Ho Chi Minh City, Viet Nam, to determine barriers associated with HBV vaccination uptake after removing the financial barrier by providing free coupons for HBV vaccination. METHODS: After being screened for HBsAg, anti-HBs, and anti-HBc, 284 HBV-naïve study participants aged 18 and over (i.e., negative for HBsAg, anti-HBs, and anti-HBc total) were provided free 3-dose HBV vaccine coupons. Next, study participants' receipt of 1st, 2nd, and 3rd doses of HBV vaccine was documented at a pre-specified study healthcare facility, where HBV vaccines were distributed at no cost to the participants. Upon study entry, participants answered questionnaires on sociodemographics, knowledge of HBV and HBV vaccination, and related social and behavioral factors. The proportions of three doses of HBV vaccine uptake and their confidence intervals were analyzed. Associations of HBV vaccine initiation with exposures at study entry were evaluated using modified Poisson regression. RESULTS: 98.9% (281 of 284) of study participants had complete data and were included in the analysis. The proportion of participants obtaining the 1st, 2nd, and 3rd doses of HBV vaccine was 11.7% (95% Confidence Interval [95% CI] 8.0-15.5%), 10.7% (95%CI 7.1-14.3%), and 8.9% (95%CI 5.6-12.2%), respectively. On the other hand, participants were more likely to initiate the 1st dose if they had adequate knowledge of transmission (adjusted relative risk [aRR] = 2.58, 95% CI 1.12-5.92), adequate knowledge of severity (aRR = 6.75, 95%CI 3.38-13.48), and annual health-checking seeking behavior (aRR = 2.04, 95%CI 1.07-3.87). CONCLUSION: We documented a low HBV vaccination uptake despite incentivization. However, increased vaccine initiation was associated with better HBV knowledge and annual health check-up adherence. When considering expanding HBV vaccination to the general adult population, we should appreciate that HBV knowledge is an independent predictor of vaccine uptake.

Early Graft Failure After Living-Donor Liver Transplant.

BACKGROUND: Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed. AIM: Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes. METHODS: Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure. RESULTS: During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001). CONCLUSION: Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Amiodarone and Dronedarone Causes Liver Injury with Distinctly Different Clinical Presentations.

OBJECTIVE: To describe hepatotoxicity due to amiodarone and dronedarone from the DILIN and the US FDA's surveillance database. METHODS: Hepatotoxicity due to amiodarone and dronedarone enrolled in the U.S. Drug Induced Liver Injury Network (DILIN) from 2004 to 2020 are described. Dronedarone hepatotoxicity cases associated with liver biopsy results were obtained from the FDA Adverse Event Reporting System (FAERS) from 2009 to 2020. RESULTS: Among DILIN's 10 amiodarone and 3 dronedarone DILIN cases, the latency for amiodarone was longer than with dronedarone (388 vs 119 days, p = 0.50) and the median ALT at DILI onset was significantly lower with amiodarone (118 vs 1191 U/L, p = 0.05). Liver biopsies in five amiodarone cases showed fibrosis, steatosis, and numerous Mallory-Denk bodies. Five patients died although only one from liver failure. One patient with dronedarone induced liver injury died of a non-liver related cause. Nine additional cases of DILI due to dronedarone requiring hospitalization were identified in the FAERS database. Three patients developed liver injury within a month of starting the medication. Two developed acute liver failure and underwent urgent liver transplant, one was evaluated for liver transplant but then recovered spontaneously, while one patient with cirrhosis died of liver related causes. CONCLUSION: Amiodarone hepatotoxicity resembles that seen in alcohol related liver injury, with fatty infiltration and inflammation. Dronedarone is less predictable, typically without fat and with a shorter latency of use before presentation. These differences may be explained, in part, by the differing pharmacokinetics of the two drugs leading to different mechanisms of hepatotoxicity.

Tolerance to decentration of biaspheric intraocular lenses with refractive phase-ring extended depth of focus and diffractive trifocal designs.

PURPOSE: This study aimed to investigate the in vitro tolerance to decentration of biaspheric intraocular lens (IOLs) with refractive phase-ring extended depth-of-focus (EDOF) and diffractive trifocal designs. METHODS: This experimental study was carried out at the Department of Optics and Optometry and Vision Science, University of Valencia, Spain. The modulation transfer function (MTF) of the ETLIO130C EDOF and the TFLIO130C trifocal IOLs (AST Products Inc., Billerica, MA, USA) were determined at different levels of decentration for a given wavelength and pupil diameter using the PMTF optical bench (Lambda-X Ophthalmics, Nivelles, Belgium). The modulation transfer function (MTF) curves, the through-focus MTF curves, and the Strehl ratios were measured at 3-mm pupil aperture for 0.25-, 0.50- and 0.75-mm decentration. RESULTS: The optical design of the trifocal TFLIO130C IOL is robust to small decentrations, with virtually no change in MTF response for 0.25 mm decentration. For greater decentration levels, the MTF response is slightly reduced with increasing decentration. The ETLIO130C EDOF design is robust to decentration, as the MTF response is only minimally affected when increasing the decentration up to 0.75 mm. CONCLUSIONS: MTF responses are slightly reduced with greater levels of decentration, but the range of focus provided by both trifocal and EDOF designs are preserved. The effects for average levels of decentration reported in the literature are minimum for both IOL designs.

Outcomes of pediatric pilonidal disease treatment: excision with off-midline flap reconstruction versus endoscopic pilonidal sinus treatment.

PURPOSE: Pilonidal disease (PD) is marked by chronic inflammation and frequent recurrence which can decrease quality of life. However, debate remains regarding the optimal treatment for PD in the pediatric population. This study compares two recommended treatment approaches-excision with off-midline flap reconstruction (OMF: Bascom cleft lift flap, modified Limberg flap) and minimally invasive endoscopic pilonidal sinus treatment (EPSiT). METHODS: Single-center retrospective evaluation of patients 1-21 years of age with PD who underwent either excision with OMF reconstruction or EPSiT between 10/1/2011 and 10/31/2021. Outcomes included were disease recurrence, reoperation, and wound complication rates. Comparisons were performed using Chi-square and Mann-Whitney U tests. RESULTS: 18 patients underwent excision/OMF reconstruction and 45 patients underwent EPSiT. The excision/OMF reconstruction cohort was predominantly male (44.4% vs 17.8% p = 0.028), with history of prior pilonidal infection (33.3% vs 6.7%; p = 0.006), and longer median operative time (60 min vs 17 min; p < 0.001). The excision/OMF reconstruction cohort had a higher rate of wound complications (22.2% vs 0%; p = 0.001), but lower rates of disease recurrence (5.6% vs 33.3%; p = 0.022) and reoperation (5.6% vs 31.1%; p = 0.031). CONCLUSION: In pediatric patients with PD, excision with OMF reconstruction may decrease recurrence and reoperation rates with increased operative times and wound complication rates, compared to EPSiT.

Cascade Synthesis of Fluorinated Spiroheterocyclic Scaffolding for Peptidic Macrobicycles.

Octafluorocyclopentene (OFCP) engages linear, unprotected peptides in polysubstitution cascades that generate complex fluorinated polycycles. The reactions occur in a single flask at 0-25 °C and require no catalysts or heavy metals. OFCP can directly polycyclize linear sequences using native functionality, or fluorospiroheterocyclic intermediates can be intercepted with exogenous nucleophiles. The latter tactic generates molecular hybrids composed of peptides, sugars, lipids, and heterocyclic components. The platform can create stereoisomers of both single- and double-looped macrocycles. Calculations indicate that the latter can mimic diverse protein surface loops. Subsets of the molecules have low energy conformers that shield the polar surface area through intramolecular hydrogen bonding. A significant fraction of OFCP-derived macrocycles tested show moderate to high passive permeability in parallel artificial membrane permeability assays.

Acute Hepatitis B Virus Infection in North American Adults.

BACKGROUND & AIMS: Acute hepatitis B virus (aHBV) is thought to be self-limited with clearance of hepatitis B surface antigen (HBsAg) within 6 months. There are limited reports of the presenting features and outcomes of adults with symptomatic aHBV in the United States. METHODS: Demographics, clinical features, and 12-month outcomes of patients with adjudicated aHBV were captured prospectively and compared with a contemporaneous cohort of chronic HBV (cHBV) patients enrolled in the Hepatitis B Research Network. RESULTS: Between 2011 and 2018, 60 adjudicated patients with aHBV were compared with 1534 cHBV untreated controls. Although similar in age, other features were dissimilar: aHBV patients were more often male (72% vs 51%), single (72% vs 30%), and non-Hispanic whites or blacks (75% vs 24%). They also were frequently genotype A2 (65% vs 9%), having different risk factors: sexual exposure (75% vs 16%) or injection drug use (10% vs 2%), compared with the cHBV controls. In addition to higher serum aminotransferase and bilirubin levels, acute patients had higher HBV DNA levels (4.8 vs 3.6 log10 IU/mL), whereas quantitative hepatitis B e antigen (HBeAg) levels were lower (1.4 vs 3.0 log10 IU/mL), despite higher rates of HBeAg (73% vs 25%). The median time to HBsAg clearance was 27 weeks and to anti-HBs appearance, 41 weeks. CONCLUSIONS: In the current era, caucasian men infected with genotype A2 as a result of sexual exposure or injection drug use were the predominant group in aHBV, suggesting a potential strategy for adult vaccination in North America. Strikingly, only an estimated 36% of subjects cleared HBsAg by month 6; the definition of resolution in acute hepatitis B may need to be modified. ClinicalTirals.gov number NCT01263587.