A wave of specific transcript and protein accumulation accompanies pollen dehydration.

In flowering plants, male gametes are immotile and carried by dry pollen grains to the female organ. Dehydrated pollen is thought to withstand abiotic stress when grains are dispersed from the anther to the pistil, after which sperm cells are delivered via pollen tube growth for fertilization and seed set. Yet, the underlying molecular changes accompanying dehydration and the impact on pollen development are poorly understood. To gain a systems perspective, we analyzed published transcriptomes and proteomes of developing Arabidopsis thaliana pollen. Waves of transcripts are evident as microspores develop to bicellular, tricellular, and mature pollen. Between the "early"- and "late"-pollen-expressed genes, an unrecognized cluster of transcripts accumulated, including those encoding late-embryogenesis abundant (LEA), desiccation-related protein, transporters, lipid-droplet associated proteins, pectin modifiers, cysteine-rich proteins, and mRNA-binding proteins. Results suggest dehydration onset initiates after bicellular pollen is formed. Proteins accumulating in mature pollen like ribosomal proteins, initiation factors, and chaperones are likely components of mRNA-protein condensates resembling "stress" granules. Our analysis has revealed many new transcripts and proteins that accompany dehydration in developing pollen. Together with published functional studies, our results point to multiple processes, including (1) protect developing pollen from hyperosmotic stress, (2) remodel the endomembrane system and walls, (3) maintain energy metabolism, (4) stabilize presynthesized mRNA and proteins in condensates of dry pollen, and (5) equip pollen for compatibility determination at the stigma and for recovery at rehydration. These findings offer novel models and molecular candidates to further determine the mechanistic basis of dehydration and desiccation tolerance in plants.

A prebiotic basis for ATP as the universal energy currency.

ATP is universally conserved as the principal energy currency in cells, driving metabolism through phosphorylation and condensation reactions. Such deep conservation suggests that ATP arose at an early stage of biochemical evolution. Yet purine synthesis requires 6 phosphorylation steps linked to ATP hydrolysis. This autocatalytic requirement for ATP to synthesize ATP implies the need for an earlier prebiotic ATP equivalent, which could drive protometabolism before purine synthesis. Why this early phosphorylating agent was replaced, and specifically with ATP rather than other nucleoside triphosphates, remains a mystery. Here, we show that the deep conservation of ATP might reflect its prebiotic chemistry in relation to another universally conserved intermediate, acetyl phosphate (AcP), which bridges between thioester and phosphate metabolism by linking acetyl CoA to the substrate-level phosphorylation of ADP. We confirm earlier results showing that AcP can phosphorylate ADP to ATP at nearly 20% yield in water in the presence of Fe3+ ions. We then show that Fe3+ and AcP are surprisingly favoured. A wide range of prebiotically relevant ions and minerals failed to catalyse ADP phosphorylation. From a panel of prebiotic phosphorylating agents, only AcP, and to a lesser extent carbamoyl phosphate, showed any significant phosphorylating potential. Critically, AcP did not phosphorylate any other nucleoside diphosphate. We use these data, reaction kinetics, and molecular dynamic simulations to infer a possible mechanism. Our findings might suggest that the reason ATP is universally conserved across life is that its formation is chemically favoured in aqueous solution under mild prebiotic conditions.

2D to 3D Reconstruction of Boron-Linked Covalent-Organic Frameworks.

The transformation of two-dimensional (2D) covalent-organic frameworks (COFs) into three-dimensions (3D) is synthetically challenging, and it is typically addressed through interlayer cross-linking of alkene or alkyne bonds. Here, we report the first example of the chemical reconstruction of a 2D COF to a 3D COF with a complete lattice rearrangement facilitated by base-triggered boron hybridization. This chemical reconstruction involves the conversion of trigonal boronate ester linkages to tetrahedral anionic spiroborate linkages. This transformation reticulates the coplanar, closely stacked square cobalt(II) phthalocyanine (PcCo) units into a 3D perpendicular arrangement. As a result, the pore size of COFs expands from 2.45 nm for the initial 2D square lattice (sql) to 3.02 nm in the 3D noninterpenetrated network (nbo). Mechanistic studies reveal a base-catalyzed boronate ester protodeboronation pathway for the formation of the spiroborate structure.

Broadening The Substrate Scope of Aldolases Through Metagenomic Enzyme Discovery.

Bio-processes based on enzymatic catalysis play a major role in the development of green, sustainable processes, and the discovery of new enzymes is key to this approach. In this work, we analysed ten metagenomes and retrieved 48 genes coding for deoxyribose-5-phosphate aldolases (DERAs, EC 4.1.2.4) using a sequence-based approach. These sequences were recombinantly expressed in Escherichia coli and screened for activity towards a range of aldol additions. Among these, one enzyme, DERA-61, proved to be particularly interesting and catalysed the aldol addition of furfural or benzaldehyde with acetone, butanone and cyclobutanone with unprecedented activity. The product of these reactions, aldols, can find applications as building blocks in the synthesis of biologically active compounds. Screening was carried out to identify optimized reaction conditions targeting temperature, pH, and salt concentrations. Lastly, the kinetics and the stereochemistry of the products were investigated, revealing that DERA-61 and other metagenomic DERAs have superior activity and stereoselectivity when they are provided with non-natural substrates, compared to well-known DERAs.

An updated assessment of hepatitis delta prevalence among adults in Canada: A meta-analysis.

Foreign-born (FB) persons represent a large proportion of adults with chronic hepatitis B (CHB) in Canada due to higher prevalence rates in countries of birth for FB persons. Suboptimal awareness and low rates of hepatitis delta virus (HDV) testing contribute to underdiagnosis and gaps in accurate estimates of Canada HDV prevalence. We aim to provide an assessment of CHB and HDV prevalence in Canada using a comprehensive literature review and meta-analysis. A comprehensive literature review of articles reporting HBsAg seroprevalence and anti-HDV prevalence was conducted to calculate country-specific rates and pooled prevalence of CHB and HDV using meta-analyses. Country-specific CHB and HDV rate estimates were combined with number of FB persons in Canada in 2021 from Statistics Canada to estimate total numbers of FB with CHB and HDV, respectively. These estimates were combined with estimates of Canada-born persons with CHB and HDV to yield the total number of persons with CHB and HDV. In 2021, we estimated 0.550 million (M) (95% CI 0.488-0.615) persons with CHB; 0.344 M (95% CI 0.288-0.401) were FB and 0.206 M (95% CI: 0.200-0.214) were Canada-born. The weighted average HDV prevalence among FB persons in Canada was 5.19% (17,848 [95% CI 9611-26,052] persons), among whom 50% emigrated from Asia and 31% from Africa. When combined with estimates of Canada-born persons with HDV, we estimate 35,059 (95% CI: 18,744-52,083) persons with HDV in Canada. In conclusion, we estimate 0.550 M and 35,059 persons living with CHB and HDV, respectively, in Canada in 2021.

Preferences and feasibility of long-acting technologies for treatment of hepatitis C virus in low- and middle-income countries: A survey of providers and policymakers.

Long-acting technologies (LATs) for hepatitis C virus (HCV) are under development as a strategy to improve linkage to care, treatment adherence and outcomes. We conducted a survey of HCV treatment prescribers and HCV policymakers in low- and middle-income countries (LMICs) regarding acceptability and feasibility of HCV LATs. We included one-time intramuscular injection, subdermal implant and transdermal patch as potential LAT options. We surveyed participants regarding optimal health system and patient characteristics, concerns, potential barriers, overall feasibility and preferences for HCV LAT as compared to daily oral medication. Overall, 122 providers and 50 policymakers from 42 LMICs completed the survey. Among providers, 93% (113/122) expressed willingness to prescribe LAT and 72% (88/120) of providers preferred LAT if provided at comparable efficacy, safety and cost as current oral treatments. Of providers preferring HCV LAT to daily oral medication, 67% (59/88) preferred injection, 24% (21/88) preferred patch and 9% (8/88) preferred implant. Only 20% (24/122) would prescribe LAT if it were more costly than oral treatment. In regression analysis, no provider characteristics were associated with preference for LAT over oral treatment. Policymakers reported high likelihood that LAT would be included in treatment guidelines (42/50; 84%) and national drug formularies (39/50; 78%) if efficacy, safety and cost were similar to oral treatment. HCV LATs could advance progress to HCV elimination in LMICs by diversifying treatment options to improve treatment coverage and outcomes. Provider preferences from LMICs are a critical consideration in the development of HCV LATs to ensure its early and equitable availability in LMICs.

Estimating the prevalence of hepatitis delta virus infection among adults in the United States: A meta-analysis.

BACKGROUND AND AIMS: Suboptimal awareness and low rates of hepatitis delta virus (HDV) testing contribute to underdiagnosis and gaps in accurate estimates of U.S. HDV prevalence. We aim to provide an updated assessment of HDV prevalence in the U.S. using a comprehensive literature review and meta-analysis approach. METHODS: A comprehensive literature review of articles reporting HBsAg seroprevalence and anti-HDV prevalence was conducted to calculate country-specific rates and pooled prevalence of CHB and HDV using meta-analyses. Country-specific CHB and HDV rate estimates were combined with number of foreign-born (FB) persons in the U.S. in 2022 from U.S. Census Bureau to estimate total numbers of FB with CHB and HDV, respectively. These estimates were further combined with updated estimates of U.S.-born persons with CHB and HDV to yield the total number of persons with CHB and HDV. RESULTS: In 2022, we estimated 1.971 million (M) (95% CI 1.547-2.508) persons with CHB; 1.547 M (95% CI 1.264-1.831) were FB and 0.424 M (95% CI: 0.282-0.678) were U.S.-born. The weighted average HDV prevalence among FB persons in the U.S. was 4.20% (64 938 [95% CI 33055-97 392] persons), among whom 45% emigrated from Asia, 25% from Africa, and 14% from Europe. When combined with updated estimates of U.S.-born persons with HDV, we estimate 75 005 (95% CI: 42187-108 393) persons with HDV in the U.S. CONCLUSIONS: Including both FB and U.S.-born persons, we estimated that 1.971 M and 75 005 persons were living with CHB and HDV, respectively, in the U.S. in 2022.

Best Practices for Hepatitis C Linkage to Care in Pregnant and Postpartum Women: Perspectives from the TiP-HepC Community of Practice.

There is an increasing burden of hepatitis C virus (HCV) among persons of reproductive age, including pregnant and breastfeeding women, in many regions worldwide. Routine health services during pregnancy present a critical window of opportunity to diagnose and link women with HCV infection for care and treatment to decrease HCV-related morbidity and early mortality. Effective treatment of HCV infection in women diagnosed during pregnancy also prevents HCV-related adverse events in pregnancy and HCV vertical transmission in future pregnancies. However, linkage to care and treatment for women diagnosed in pregnancy remains insufficient. Currently, there are no best practice recommendations from professional societies to ensure appropriate peripartum linkage to HCV care and treatment. We convened a virtual Community of Practice (CoP) to understand key challenges to the HCV care cascade for women diagnosed with HCV in pregnancy, highlight published models of integrated HCV services for pregnant and postpartum women, and preview upcoming research and programmatic initiatives to improve linkage to HCV care for this population. Four-hundred seventy-three participants from 43 countries participated in the CoP, including a diverse range of practitioners from public health, primary care, and clinical specialties. The CoP included panel sessions with representatives from major professional societies in obstetrics/gynecology, maternal fetal medicine, addiction medicine, hepatology, and infectious diseases. From this CoP, we provide a series of best practices to improve linkage to HCV treatment for pregnant and postpartum women, including specific interventions to enhance co-location of services, treatment by non-specialist providers, active engagement and patient navigation, and decreasing time to HCV treatment initiation. The CoP aims to further support antenatal providers in improving linkage to care by producing and disseminating detailed operational guidance and recommendations and supporting operational research on models for linkage and treatment. Additionally, the CoP may be leveraged to build training materials and toolkits for antenatal providers, convene experts to formalize operational recommendations, and conduct surveys to understand needs of antenatal providers. Such actions are required to ensure equitable access to HCV treatment for women diagnosed with HCV in pregnancy and urgently needed to achieve the ambitious targets for HCV elimination by 2030.

A phase II trial of apalutamide for intermediate-risk prostate cancer and molecular correlates.

OBJECTIVES: To determine whether 6 months of preoperative apalutamide for intermediate-risk prostate cancer (IRPCa) reduces the aggregate postoperative radiotherapy risk and to evaluate associations of molecular perturbations with clinical outcomes in this study cohort. PATIENTS AND METHODS: Between May 2018 and February 2020, eligible patients with IRPCa (Gleason 3 + 4 or 4 + 3 and clinical T2b-c or prostate-specific antigen level of 10-20 ng/mL) were treated with apalutamide 240 mg/day for 6 months followed by radical prostatectomy (RP) in this single-arm, phase II trial. The primary endpoint was presence of any adverse pathological feature at risk of pelvic radiation (pathological T stage after neoadjuvant therapy [yp]T3 or ypN1 or positive surgical margins). Translational studies, including germline and somatic DNA alterations and RNA and protein expression, were performed on post-apalutamide RP specimens, and assessed for associations with clinical outcomes. RESULTS: A total of 40 patients underwent a RP, and only one patient discontinued apalutamide prior to 6 months. In all, 40% had adverse pathological features at time of RP, and the 3-year biochemical recurrence (BCR) rate was 15%, with 27.5% being not evaluable. Genomic alterations frequently seen in metastatic PCas, such as androgen receptor (AR), tumour protein p53 (TP53), phosphatase and tensin homologue (PTEN), or BReast CAncer associated gene (BRCA1/2) were underrepresented in this localised cohort. Adverse pathological features and BCR at 3-years were associated with increased expression of select cell cycle (e.g., E2F targets: adjusted P value [Padj] < 0.001, normalised enrichment score [NES] 2.47) and oxidative phosphorylation (Padj < 0.001, NES 1.62) pathways. CONCLUSIONS: Preoperative apalutamide did not reduce the aggregate postoperative radiation risk to the pre-specified threshold in unselected men with IRPCa. However, transcriptomic analysis identified key dysregulated pathways in tumours associated with adverse pathological outcomes and BCR, which warrant future study. Further investigation of preoperative therapy is underway for men with high-risk PCa.

Hepatitis C Elimination in Rwanda: Progress, Feasibility, and Economic Evaluation.

OBJECTIVES: In 2018, Rwanda launched a national program to eliminate the hepatitis C virus (HCV). We aim to assess the impact of the program to date and identify strategies to achieve the World Health Organization's HCV elimination goals by 2030. METHODS: We developed a microsimulation model to simulate Rwanda's HCV epidemic from 2015 through 2050 and evaluated temporal trends in HCV infection, prevalence, mortality, and the total cost of care for scenarios that could achieve HCV elimination by 2030. RESULTS: Between 2018 and 2022, over 7 million people were screened for HCV, and 60 000 were treated. The study projected that Rwanda could achieve HCV elimination as early as 2027. A feasible strategy of an annual screening rate of 15% and a treatment rate of 100% would achieve all World Health Organization elimination goals by 2028, requiring screening an additional 4 million people and treating 23 900 patients by 2030. The elimination strategy costs $25 million for screening and diagnosis and $21 million for treatment from 2015 to 2050. The national program would avert 4900 hepatocellular carcinoma cases and 6700 HCV-related deaths and save the health system $25.33 million from 2015 to 2050. CONCLUSIONS: Rwanda is poised to become one of the first countries in the world to eliminate HCV. Rwanda's program serves as a blueprint for other countries in the African region. By rapid screening and treatment scale-up (eg, by leveraging HIV platforms) and by drug price negotiations, HCV elimination is not only feasible but can be cost-saving in low-income settings.

Asymmetric α-arylation of amino acids.

Quaternary amino acids, in which the α-carbon that bears the amino and carboxyl groups also carries two carbon substituents, have an important role as modifiers of peptide conformation and bioactivity and as precursors of medicinally important compounds1,2. In contrast to enantioselective alkylation at this α-carbon, for which there are several methods3-8, general enantioselective introduction of an aryl substituent at the α-carbon is synthetically challenging9. Nonetheless, the resultant α-aryl amino acids and their derivatives are valuable precursors to bioactive molecules10,11. Here we describe the synthesis of quaternary α-aryl amino acids from enantiopure amino acid precursors by α-arylation without loss of stereochemical integrity. Our approach relies on the temporary formation of a second stereogenic centre in an N'-arylurea adduct12 of an imidazolidinone derivative6 of the precursor amino acid, and uses readily available enantiopure amino acids both as a precursor and as a source of asymmetry. It avoids the use of valuable transition metals, and enables arylation with electron-rich, electron-poor and heterocyclic substituents. Either enantiomer of the product can be formed from a single amino acid precursor. The method is practical and scalable, and provides the opportunity to produce α-arylated quaternary amino acids in multi-gram quantities.

Patient, supporter and primary healthcare professional perspectives on health risks in over 16s with attention deficit hyperactivity disorder (ADHD) in England: a national survey study.

BACKGROUND: Current research suggests that people with attention deficit hyperactivity disorder (ADHD) are at higher risk of physical and mental health disorders. This study aimed to explore these health risks in ADHD from the perspectives of multiple stakeholders. METHODS: This study forms part of the 'Managing young people with ADHD in Primary care (MAP) study'. A survey developed by the study team was distributed to over 16 year olds with ADHD, their supporters, primary healthcare professionals and health commissioners across England, via social media and through patient/clinical networks (September-October 2022). This survey contained two questions on health risks. Question one asked about views on health risks in ADHD (free text). Question two asked about advice given (options list and free text). Descriptive statistics summarised responses to questions one and two, and qualitative analysis (reflexive thematic analysis) was used to explore free text responses from question one. RESULTS: 782 participants responded to the MAP survey. Of these, 206 healthcare professionals, 157 people with ADHD and 88 supporters answered question one. The most mentioned perceived risks were substance misuse, sleep disorders, weight management and smoking. More people with ADHD reported disordered eating as a health risk (n = 32) than healthcare professionals (n = 5). Generated themes included perceived health risks, impact of living with ADHD, lack of adequate healthcare, and need for ADHD awareness. In respect to advice given (question two), based on responses from 258 professionals, 162 people with ADHD and 100 supporters, the most common advice discussed in consultation was mental health (n = 149, n = 50 and n = 17 respectively). High numbers of respondents reported not giving/receiving advice on wider health (n = 38, n = 88 and n = 61 respectively). CONCLUSIONS: Findings demonstrate that respondents perceived a range of physical and mental health risks posed by ADHD. These related to difficulties with activities of daily living, as well as healthcare interactions and the impact of core features of ADHD (e.g. impulsivity, emotional dysregulation). These risks are not currently explicitly addressed in United Kingdom national guidance on ADHD. More work is needed to examine and address the broader health outcomes of people with ADHD.

Strategies for Removal of Barriers to Hepatitis C Elimination in Sub-Saharan Africa.

Hepatitis C virus (HCV) infection is a major global health threat, with serious consequences including liver cirrhosis and cancer. Despite efforts to combat HCV, an estimated 1.5 million new infections occur each year and HCV was the sixth leading cause of death in 2017. Nevertheless, political leaders are increasingly interested in the fight against HCV, and the achievements of countries such as Rwanda, Egypt, India, Mongolia, Pakistan, Georgia, and Ukraine have given hope that the elimination plan to reduce new infections to 90% and mortality to 65% by 2030 is possible. It is true that some African countries can attest to the difficulty of operationalizing the HCV program with expensive testing platforms and HCV drugs that few could afford in the past, let alone the logistics involved, given that active case detection is an asset for HCV elimination. The inability to add direct-acting antivirals (DAAs) to the national essential drug list and negotiate DAA cost subsidies remains a major challenge in Africa. The lessons learned from implementing and scaling up the human immunodeficiency virus program can provide a strong framework to deliver comprehensive HCV services. We present the strategies used by some African countries to move toward HCV elimination, describe the challenges they have faced, and suggest realistic solutions.

An Assessment of National Strategic Action Plans for Viral Hepatitis Elimination, 2016-2021.

In 2016, the World Health Organization (WHO) released the Global Health Sector Strategy (GHSS) setting goals for global hepatitis elimination. To inform new or revised viral hepatitis national strategic action plans (NSAPs) for 2022-2030, NSAPs developed during 2016-2021 were assessed for alignment with the WHO GHSS. Country NSAPs were assessed to determine if they included components in the 2016 GHSS. Of 55 country NSAPs, 19 (35%) did not include hepatitis B and C virus elimination goals, only 18 (33%) included targets for needles and syringes for persons who inject drugs, and 21 (38%) had a national budget or financing plan for hepatitis activities. Gaps identified indicate need for technical support in NSAP development.

Tools Needed to Support Same-day Diagnosis and Treatment of Current Hepatitis C Infection.

Current HCV prevention efforts and treatment rates must improve for the United States (U.S.) to achieve WHO global elimination targets by 2030[1]. The current multi-day diagnosis and treatment paradigm for hepatitis C (HCV) infection leads to significant loss in the cascade of care, resulting in far fewer patients receiving treatment with direct acting antiviral agents (DAAs) than those diagnosed with HCV infection [2,3]. To achieve HCV elimination, a paradigm shift in access to HCV treatment is needed from current multi-day testing and treatment algorithms to same day diagnosis and treatment. This shift will require new tools, such as FDA-approved, CLIA-waived point-of-care (POC) antigen or nucleic acid tests (NAT) for HCV and HBV and NAT for HIV that do not require venous blood. Such a shift will also require better utilization of existing resources, expanding access to HCV treatment through availability of onsite treatment, removal of payer barriers to approval, adoption of minimal monitoring approaches during treatment, expanded access to available POC tests, and available specialist referral networks for patients who fail initial therapy, have advanced liver fibrosis, or have co-incident HIV or HBV infection. A same-day diagnosis and treatment paradigm will substantially contribute to HCV elimination by improving treatment rates for those diagnosed with HCV infection and expanding access to treatment in settings where patients have brief encounters with healthcare.

Hepatitis C Elimination in Moldova Is Feasible and Cost-Saving: A Modeling Study.

BACKGROUND: Moldova, an upper-middle-income country in Eastern Europe, is facing a high burden of hepatitis C virus (HCV). Our objective was to assist the National Agency of Public Health of Moldova in planning to achieve the World Health Organization's HCV elimination goals by 2030. METHODS: This study adapted a previously developed microsimulation model to simulate the HCV epidemic in Moldova from 2004 to 2050. Model outcomes included temporal trends in HCV infection, prevalence, mortality, and total cost of care, including screening and treatment. We evaluated scenarios that could eliminate HCV by 2030. RESULTS: Multiple strategies could lead to HCV elimination in Moldova by 2030. A realistic scenario of a 20% annual screening and 80% treatment rate would require 2.75 million individuals to be screened and 65 000 treated by 2030. Compared to 2015, this program will reduce HCV incidence by 98% and HCV-related deaths by 72% in 2030. Between 2022 and 2030, this strategy would cost $17.5 million for HCV screening and treatment. However, by 2050, the health system would save >$85 million compared to no investment in elimination efforts. CONCLUSIONS: HCV elimination in Moldova is feasible and can be cost saving, but requires resources to scale HCV screening and treatment.

Reflex Hepatitis C Virus Viral Load Testing Following an Initial Positive Hepatitis C Virus Antibody Test: A Global Systematic Review and Meta-analysis.

BACKGROUND: Many people who have a positive hepatitis C virus (HCV) antibody (Ab) test never receive a confirmatory HCV RNA viral load (VL) test. Reflex VL testing may help address this problem. We undertook a systematic review to evaluate the effectiveness of reflex VL testing compared with standard nonreflex approaches on outcomes across the HCV care cascade. METHODS: We searched 4 databases for studies that examined laboratory-based reflex or clinic-based reflex VL testing approaches, with or without a nonreflex comparator, and had data on the uptake of HCV RNA VL test and treatment initiation and turnaround time between Ab and VL testing. Both laboratory- and clinic-based reflex VL testing involve only a single clinic visit. Summary estimates were calculated using random-effects meta-analyses. RESULTS: Fifty-one studies were included (32 laboratory-based and 19 clinic-based reflex VL testing). Laboratory-based reflex VL testing increased HCV VL test uptake versus nonreflex testing (RR: 1.35; 95% CI: 1.16-1.58) and may improve linkage to care among people with a positive HCV RNA test (RR: 1.47; 95% CI: .81-2.67) and HCV treatment initiation (RR: 1.03; 95% CI: .46-2.32). The median time between Ab and VL test was <1 day for all laboratory-based reflex studies and 0-5 days for 13 clinic-based reflex testing. CONCLUSIONS: Laboratory-based and clinic-based HCV reflex VL testing increased uptake and reduced time to HCV VL testing and may increase HCV linkage to care. The World Health Organization now recommends reflex VL testing as an additional strategy to promote access to HCV VL testing and treatment. CLINICAL TRIALS REGISTRATION: PROSPERO CRD42021283822.

Dynamic and Persistent Cyclochirality in Hydrogen-Bonded Derivatives of Medium-Ring Triamines.

Cyclic triureas derived from 1,4,7-triazacyclononane (TACN) were synthesized; X-ray crystallography showed a chiral bowl-like conformation with each urea hydrogen-bonded to its neighbor with uniform directionality, forming a "cyclochiral" closed loop of hydrogen bonds. Variable-temperature 1H NMR, 1H-1H exchange spectroscopy, Eyring analysis, computational modeling, and studies in various solvents revealed that cyclochirality is dynamic (ΔG‡25°C = 63-71 kJ mol-1 in noncoordinating solvents), exchanging between enantiomers by two mechanisms: bowl inversion and directionality reversal, with the former subject to a slightly smaller enantiomerization barrier. The enantiomerization rate substantially increased in the presence of hydrogen-bonding solvents. Population of only one of the two cyclochiral hydrogen-bond directionalities could be induced by annulating one ethylene bridge with a trans-cyclohexane. Alternatively, enantiomerization could be inhibited by annulating one ethylene bridge with a cis-cyclohexane (preventing bowl inversion) and replacing one urea function with a formamide (preventing directionality reversal). Combining these structural modifications resulted in an enantiomerization barrier of ΔG‡25°C = 93 kJ mol-1, furnishing a planar-chiral, atropisomeric bowl-shaped structure whose stereochemical stability arises solely from its hydrogen-bonding network.

Prevention of Hepatocellular Carcinoma (HCC). White Paper of the Texas Collaborative Center for Hepatocellular Cancer (TeCH) Multi-stakeholder Conference.

BACKGROUND & AIMS: Texas has the highest age-adjusted incidence rate of hepatocellular carcinoma (HCC) in the United States. The Cancer Prevention and Research Institute of Texas has funded the Texas Collaborative Center for Hepatocellular Cancer (TeCH) to facilitate HCC research, education, and advocacy activities with the overall goal of reducing HCC mortality in Texas through coordination, collaboration, and advocacy. METHODS: On September 17, 2022, TeCH co-sponsored a multi-stakeholder conference on HCC with the Baker Institute Center for Health and Biosciences. This conference was attended by HCC researchers, policy makers, payers, members from pharmaceutical industry and patient advocacy groups in and outside of Texas. This report summarizes the results of the conference. RESULTS: The goal of this meeting was to identify different strategies for preventing HCC and evaluate their readiness for implementation. CONCLUSIONS: We call for a statewide (1) viral hepatitis elimination program; (2) program to increase nonalcoholic steatohepatitis and obesity awareness; (3) research program to develop health care models that integrate alcohol associated liver disease treatment and treatment for alcohol use disorder; and (4) demonstration projects to evaluate the effectiveness of identifying and linking patient with advanced fibrosis and cirrhosis to clinical care.

Informing a target product profile for rapid tests to identify HBV-infected pregnant women with high viral loads: a discrete choice experiment with African healthcare workers.

BACKGROUND: Elimination of mother-to-child transmission of hepatitis B virus (HBV) requires infant immunoprophylaxis and antiviral prophylaxis for pregnant women with high viral loads. Since real-time polymerase chain reaction (RT-PCR), a gold standard for assessing antiviral eligibility, is neither accessible nor affordable for women living in low-income and middle-income countries (LMICs), rapid diagnostic tests (RDTs) detecting alternative HBV markers may be needed. To inform future development of the target product profile (TPP) for RDTs to identify highly viremic women, we used a discrete choice experiment (DCE) and elicited preference and trade-off of healthcare workers (HCW) in Africa between the following four attributes of fictional RDTs: price, time-to-result, diagnostic sensitivity, and specificity. METHODS: Through an online questionnaire survey, we asked participants to indicate their preferred test from a set of two RDTs in seven choice tasks with varying levels of the four attributes. We used mixed multinomial logit models to quantify the utility gain or loss generated by each attribute. We attempted to define minimal and optimal criteria for test attributes that can satisfy ≥ 70% and ≥ 90% of HCWs, respectively, as an alternative to RT-PCR. RESULTS: A total of 555 HCWs from 41 African countries participated. Increases in sensitivity and specificity generated significant utility and increases in cost and time-to-result generated significant disutility. The size of the coefficients for the highest attribute levels relative to the reference levels were in the following order: sensitivity (ß = 3.749), cost (ß = -2.550), specificity (ß = 1.134), and time-to-result (ß = -0.284). Doctors cared most about test sensitivity, while public health practitioners cared about cost and midwives about time-to-result. For an RDT with 95% specificity, costing 1 US$, and yielding results in 20 min, the minimally acceptable test sensitivity would be 82.5% and the optimally acceptable sensitivity would be 87.5%. CONCLUSIONS: African HCWs would prefer an RDT with the following order of priority: higher sensitivity, lower cost, higher specificity, and shorter time-to-result. The development and optimization of RDTs that can meet the criteria are urgently needed to scale up the prevention of HBV mother-to-child transmission in LMICs.