International review of blood donation screening for anti-HBc and occult hepatitis B virus infection.

BACKGROUND: Hepatitis B core antibody (anti-HBc) screening has been implemented in many blood establishments to help prevent transmission of hepatitis B virus (HBV), including from donors with occult HBV infection (OBI). We review HBV screening algorithms across blood establishments globally and their potential effectiveness in reducing transmission risk. MATERIALS AND METHODS: A questionnaire on HBV screening and follow-up strategies was distributed to members of the International Society of Blood Transfusion working party on transfusion-transmitted infectious diseases. Screening data from 2022 were assimilated and analyzed. RESULTS: A total of 30 unique responses were received from 25 countries. Sixteen respondents screened all donations for anti-HBc, with 14 also screening all donations for HBV DNA. Anti-HBc prevalence was 0.42% in all blood donors and 1.19% in new donors in low-endemic countries; however, only 44% of respondents performed additional anti-HBc testing to exclude false reactivity. 0.68% of anti-HBc positive, HBsAg-negative donors had detectable HBV DNA. Ten respondents did universal HBV DNA screening without anti-HBc, whereas four respondents did not screen for either. Deferral strategies for anti-HBc positive donors were highly variable. One transfusion-transmission from an anti-HBc negative donor was reported. DISCUSSION: Anti-HBc screening identifies donors with OBI but also results in the unnecessary deferral of a significant number of donors with resolved HBV infection and donors with false-reactive anti-HBc results. Whilst confirmation of anti-HBc results could be improved to reduce donor deferral, transmission risks associated with anti-HBc negative OBI donors must be considered. In high-endemic areas, highly sensitive HBV DNA testing is required to identify infectious donors.

Spatial oncology: Translating contextual biology to the clinic.

Microscopic examination of cells in their tissue context has been the driving force behind diagnostic histopathology over the past two centuries. Recently, the rise of advanced molecular biomarkers identified through single cell profiling has increased our understanding of cellular heterogeneity in cancer but have yet to significantly impact clinical care. Spatial technologies integrating molecular profiling with microenvironmental features are poised to bridge this translational gap by providing critical in situ context for understanding cellular interactions and organization. Here, we review how spatial tools have been used to study tumor ecosystems and their clinical applications. We detail findings in cell-cell interactions, microenvironment composition, and tissue remodeling for immune evasion and therapeutic resistance. Additionally, we highlight the emerging role of multi-omic spatial profiling for characterizing clinically relevant features including perineural invasion, tertiary lymphoid structures, and the tumor-stroma interface. Finally, we explore strategies for clinical integration and their augmentation of therapeutic and diagnostic approaches.

Challenges in the diagnosis and management of dry tamponade.

Dry tamponade is a rare complication of percutaneous coronary intervention. It encompasses a heterogenous pathophysiology and is used to describe hemodynamic compromise secondary to a coronary artery perforation, without free-flowing fluid in the pericardium. Tamponade physiology can result from compressive epicardial, intramyocardial, subepicardial hematomas, or dissecting intramyocardial hematomas. The diagnosis of dry tamponade requires hemodynamic derangement in the context of a compressive hematoma as demonstrated by imaging. Although echocardiography can often help identify dry tamponade, additional studies including right heart catheterization, computed tomography, or cardiac magnetic resonance imaging can inform the exact mechanism and help guide management. This article describes a case of dry tamponade, reviews the existing literature on the topic, and offers expert recommendations on diagnosis and management.

Atlanto-occipital Dissociation: A Review on Epidemiology, Recognition and Diagnosis, Management Options, Outcomes, and Future Directions.

Atlanto-occipital dissociation (AOD) is an extremely common injury but often fatal. In a systematic review from 2010, AODs were present in almost 20% of blunt trauma fatalities. It is an injury many patients do not survive; therefore, few are treated, even at high volume trauma centers. In survivors, his injury is often missed or the diagnosis is often delayed. Mortality rates commonly reach beyond 60% when injury patterns go unrecognized. Approximately 50% of patients with AOD sustain blunt cerebrovascular injury and nearly 20% of patients present with traumatic brain injury (TBI) or stroke. This pathology was once considered uniformly fatal. However, over the last 20 years, significant advancements have been made both clinically and radiographically, to better identify and manage this injury pattern. Despite improvements in clinical comprehension and improved time to diagnosis, less than 75% of cases are currently recognized within 24 hours. Less than 40% of patients who suffer AOD are independent with functionality, without neurological impairment. This article reviews current literature regarding AOD in hopes to improve timing to diagnosis, subsequent prognosis, timing to fixation or stabilization, and postoperative recovery.

Prodrug nanotherapy demonstrates in vivo anticryptosporidial efficacy in a mouse model of chronic Cryptosporidium infection.

The gastrointestinal disease cryptosporidiosis, caused by the genus Cryptosporidium, is a common cause of diarrheal diseases in children, particularly in developing countries and frequently fatal in immunocompromised individuals. Cryptosporidium hominis (Ch)-specific bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) has been a molecular target for inhibitor design. (Note that this bifunctional enzyme has also been referred to as TS-DHFR in previous literature since the functional biochemical reaction first involves the conversion of methylene tetrahydrofolate to dihydrofolate at the TS site.) While nanomolar inhibitors of Ch DHFR-TS have been identified at the biochemical level, effective delivery of these compounds to achieve anticryptosporidial activity in cell culture and in vivo models of parasite infection remains a major challenge in developing new therapies. Previous studies, using a nanotherapy approach, have shown a promising Ch DHFR-TS inhibitor, 906, that can successfully target Cryptosporidium parasites in cell culture with nanomolar anticryptosporidial activity. This formulation utilized poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with 906 (NP-906) and conjugated with a Cryptosporidium monoclonal antibody (MAb) on the nanoparticle surface to specifically target the glycoprotein GP25-200 in excysting oocysts. However, a limitation for in vivo use is antibody susceptibility to gastric acidity. To address this gap, a prodrug diethyl ester form of 906 (MAb-NP-Prodrug) was synthesized that allowed higher compound loading in the MAb-coated PLGA nanoparticles. An oral formulation was prepared by loading lyophilized MAb-NP-Prodrug into gelatin capsules with an enteric coating for gastric stability. Proof-of-concept studies with this oral formulation demonstrated antiparasitic activity in a chronic mouse model of Cryptosporidium infection. Efficacy was observed after a low daily dose of 2 × 8 mg kg-1 for 5 days, when examined 6 and 20 days postinfection, offering a new avenue of drug delivery to be further explored.

IPECAD Modeling Workshop 2023 Cross Comparison Challenge on Cost-Effectiveness Models in Alzheimer's Disease.

OBJECTIVES: Decision-analytic models assessing the value of emerging Alzheimer's disease (AD) treatments are challenged by limited evidence on short-term trial outcomes and uncertainty in extrapolating long-term patient-relevant outcomes. To improve understanding and foster transparency and credibility in modeling methods, we cross-compared AD decision models in a hypothetical context of disease-modifying treatment for mild cognitive impairment (MCI) due to AD. METHODS: A benchmark scenario (US setting) was used with target population MCI due to AD and a set of synthetically generated hypothetical trial efficacy estimates. Treatment costs were excluded. Model predictions (10-year horizon) were assessed and discussed during a 2-day workshop. RESULTS: Nine modeling groups provided model predictions. Implementation of treatment effectiveness varied across models based on trial efficacy outcome selection (CDR-SB, CDR-global, MMSE, FAQ) and analysis method (observed severity transitions, change from baseline, progression hazard ratio, or calibration to these). Predicted mean time in MCI ranged from 2.6-5.2 years for control strategy, and from 0.1-1.0 years for difference between intervention and control strategies. Predicted quality-adjusted life-year gains ranged from 0.0-0.6 and incremental costs (excluding treatment costs) from -US$66,897 to US$11,896. CONCLUSIONS: Trial data can be implemented in different ways across health-economic models leading to large variation in model predictions. We recommend 1) addressing the choice of outcome measure and treatment effectiveness assumptions in sensitivity analysis, 2) a standardized reporting table for model predictions, and 3) exploring the use of registries for future AD treatments measuring long-term disease progression to reduce uncertainty of extrapolating short-term trial results by health economic models.

A compact stem-loop DNA aptamer targets a uracil-binding pocket in the SARS-CoV-2 nucleocapsid RNA-binding domain.

SARS-CoV-2 nucleocapsid (N) protein is a structural component of the virus with essential roles in the replication and packaging of the viral RNA genome. The N protein is also an important target of COVID-19 antigen tests and a promising vaccine candidate along with the spike protein. Here, we report a compact stem-loop DNA aptamer that binds tightly to the N-terminal RNA-binding domain of SARS-CoV-2 N protein. Crystallographic analysis shows that a hexanucleotide DNA motif (5'-TCGGAT-3') of the aptamer fits into a positively charged concave surface of N-NTD and engages essential RNA-binding residues including Tyr109, which mediates a sequence-specific interaction in a uracil-binding pocket. Avid binding of the DNA aptamer allows isolation and sensitive detection of full-length N protein from crude cell lysates, demonstrating its selectivity and utility in biochemical applications. We further designed a chemically modified DNA aptamer and used it as a probe to examine the interaction of N-NTD with various RNA motifs, which revealed a strong preference for uridine-rich sequences. Our studies provide a high-affinity chemical probe for the SARS-CoV-2 N protein RNA-binding domain, which may be useful for diagnostic applications and investigating novel antiviral agents.

Risk of Clade II Mpox Associated with Intimate and Nonintimate Close Contact Among Men Who Have Sex with Men and Transgender Adults - United States, August 2022-July 2023.

A global outbreak of clade II mpox associated with sexual contact, disproportionately affecting gay, bisexual, and other men who have sex with men (MSM), has been ongoing since May 2022. Information on types of contact most associated with transmission is limited. This report used data from a multijurisdictional vaccine effectiveness case-control study of sexually active persons aged 18-49 years who identified as MSM or transgender, collected during August 2022-July 2023. Odds of mpox associated with selected types of intimate and nonintimate close contact with a person with mpox were estimated. Among 457 case-patients and 1,030 control patients who met minimum data requirements, 150 (32.8%) case-patients and 57 (5.5%) control patients reported close contact with a person with mpox and were included in this analysis. Adjusted odds of mpox were 5.4 times as high among those who reported having condomless receptive anal sex with a person with mpox, compared with participants who reported close contact with a person with mpox and no condomless receptive anal sex with that person (OR = 5.4; p = 0.031). Although the mpox vaccine is highly effective, vaccination coverage remains low; a multifaceted approach to prevention remains important and should include vaccination promotion, safer sex practices, and increasing awareness that mpox continues to circulate.

RADD: A real-time FRET-based biochemical assay for DNA deaminase studies.

In recent years, the connection between APOBEC3 cytosine deaminases and cancer mutagenesis has become ever more apparent. This growing awareness and lack of inhibitory drugs has created a distinct need for biochemical tools that can be used to identify and characterize potential inhibitors of this family of enzymes. In response to this challenge, we have developed a Real-time APOBEC3-mediated DNA Deamination (RADD) assay. The RADD assay provides a rapid, real-time fluorescence readout of APOBEC3 DNA deamination and serves as a crucial addition to the existing APOBEC3 biochemical and cellular toolkit. This method improves upon contemporary DNA deamination assays by offering a more rapid and quantifiable readout as well as providing a platform that is readily adaptable to a high-throughput format for inhibitor discovery. In this chapter we provide a detailed guide for the usage of the RADD assay for the characterization of APOBEC3 enzymes and potential inhibitors.

Ogden R. Lindsley: I Followed the Idea of the Missoula Smokejumpers.

In 1990, Ogden R. Lindsley served as guest faculty for Ohio State University's Teleconference on applied behavior analysis. He captivated students and faculty with tales of his personal journey from experiences during World War II to studying under B. F. Skinner, and his development of precision teaching (PT) to preserve rate of response measurement in educational applications. Derived from an audio cassette recording of that seminar session, this article captures highlights of those stories and Dr. Lindsley's discussion of topics ranging from his opinion of the open classroom movement to critiques of Sesame Street and errorless learning.

Paediatric trigger thumb: Diagnostic pearls.

AIM: The purpose of this study is to report diagnostic pearls and review the clinical presentation and outcomes of surgical treatment of paediatric trigger thumbs. METHODS: A retrospective review of medical records and imaging studies was performed on children with trigger thumbs from January 2009 to December 2019. RESULTS: Sixty-four trigger thumbs in 52 consecutive patients were treated. The average age at referral was 2.5 years. Symptoms include pain (4), triggering (14) and fixed contracture (38). The average symptom duration was 8 months. Forty patients had been evaluated and referred by a paediatrician or primary care doctor. Twenty-four of the 52 (46%) patients received hand x-rays and were initially misdiagnosed as a fracture or dislocation. Physical exam demonstrated a volar nodule in 64 thumbs (100%), fixed flexion deformities in 38 (73%) thumbs and triggering with active extension of the interphalangeal joint in 14 (27%) thumbs. The average age at surgery was 3.2 years. Follow-up averaged 12 months. Surgery resulted in complete relief of symptoms and correction of deformity. There was no reported loss of function or complication. CONCLUSIONS: Children with trigger thumbs who ultimately undergo surgery present with distinct physical exam findings, including a volar nodule and a fixed flexion contracture. Understanding these pearls can minimise misdiagnosis of the condition as a fracture or dislocation. Highlighting trigger thumbs during musculoskeletal education for paediatric and primary care physicians is recommended. Surgical outcomes were excellent in patients aged 2-8 years old.

Palladium-catalyzed cross-coupling of alcohols with olefins by positional tuning of a counteranion.

Transition metal-catalyzed cross-couplings have great potential to furnish complex ethers; however, challenges in the C(sp3)-O functionalization step have precluded general methods. Here, we describe computationally guided transition metal-ligand design that positions a hydrogen-bond acceptor anion at the reactive site to promote functionalization. A general cross-coupling of primary, secondary, and tertiary aliphatic alcohols with terminal olefins to furnish >130 ethers is achieved. The mild conditions tolerate functionality that is prone to substitution, elimination, and epimerization and achieve site selectivity in polyol settings. Mechanistic studies support the hypothesis that the ligand's geometry and electronics direct positioning of the phosphate anion at the π-allyl-palladium terminus, facilitating the phosphate's hydrogen-bond acceptor role toward the alcohol. Ligand-directed counteranion positioning in cationic transition metal catalysis has the potential to be a general strategy for promoting challenging bimolecular reactivity.

Stabilizing selection and mitochondrial heteroplasmy in the Canada lynx (Lynx canadensis).

Mitochondrial DNA is commonly used in population genetic studies to investigate spatial structure, intraspecific variation, and phylogenetic relationships. The control region is the most rapidly evolving and largest non-coding region, but its analysis can be complicated by heteroplasmic signals of genome duplication in many mammals, including felids. Here, we describe the presence of heteroplasmy in the control region of Canada lynx (Lynx canadensis) through intra-individual sequence variation. Our results demonstrate multiple haplotypes of varying length in each lynx, resulting from different copy numbers of the repetitive sequence RS-2 and suggest possible heteroplasmic single nucleotide polymorphisms (SNPs) in both repetitive sequences RS-2 and RS-3. Intra-individual variation was only observed in the repetitive sequences while inter-individual variation was detected in the flanking regions outside of the repetitive sequences, indicating that heteroplasmic mutations are restricted to these repeat regions. Although each lynx displayed multiple haplotypes of varying length, we found the most common variant contained three complete copies of the RS-2 repeat unit, suggesting copy number is regulated by stabilizing selection. While genome duplication offers potential for increased diversity, heteroplasmy may lead to a selective advantage or detriment in the face of mitochondrial function and disease, which could have significant implications for wildlife populations experiencing decline (e.g., bottlenecks) as a result of habitat modification or climate change.

Biallelic PTPMT1 variants disrupt cardiolipin metabolism and lead to a neurodevelopmental syndrome.

Primary mitochondrial diseases (PMDs) are among the most common inherited neurological disorders. They are caused by pathogenic variants in mitochondrial or nuclear DNA that disrupt mitochondrial structure and/or function, leading to impaired oxidative phosphorylation (OXPHOS). One emerging subcategory of PMDs involves defective phospholipid (PL) metabolism. Cardiolipin (CL), the signature PL of mitochondria, resides primarily in the inner mitochondrial membrane, where it is biosynthesised and remodelled via multiple enzymes and is fundamental to several aspects of mitochondrial biology. Genes that contribute to CL biosynthesis have recently been linked with PMD. However, the pathophysiological mechanisms that underpin human CL-related PMDs are not fully characterised. Here, we report six individuals, from three independent families, harbouring biallelic variants in PTPMT1, a mitochondrial tyrosine phosphatase required for de novo CL biosynthesis. All patients presented with a complex, neonatal/infantile onset neurological and neurodevelopmental syndrome comprising developmental delay, microcephaly, facial dysmorphism, epilepsy, spasticity, cerebellar ataxia and nystagmus, sensorineural hearing loss, optic atrophy, and bulbar dysfunction. Brain MRI revealed a variable combination of corpus callosum thinning, cerebellar atrophy, and white matter changes. Using patient-derived fibroblasts and skeletal muscle tissue, combined with cellular rescue experiments, we characterise the molecular defects associated with mutant PTPMT1 and confirm the downstream pathogenic effects that loss of PTPMT1 has on mitochondrial structure and function. To further characterise the functional role of PTPMT1 in CL homeostasis, we established a zebrafish ptpmt1 knockout model associated with abnormalities in body size, developmental alterations, decreased total CL levels, and OXPHOS deficiency. Together, these data indicate that loss of PTPMT1 function is associated with a new autosomal recessive PMD caused by impaired CL metabolism, highlight the contribution of aberrant CL metabolism towards human disease, and emphasise the importance of normal CL homeostasis during neurodevelopment.

A Draft Pacific Ancestry Pangenome Reference.

Individuals of Pacific ancestry suffer some of the highest rates of health disparities yet remain vastly underrepresented in genomic research, including currently available linear and pangenome references. To begin addressing this, we developed the first Pacific ancestry pangenome reference using 23 individuals with diverse Pacific ancestry. We assembled 46 haploid genomes from these 23 individuals, resulting in highly accurate and contiguous genome assemblies with an average quality value of 55.0 and an average N50 of 40.7 Mb, marking the first de novo assembly of highly accurate Pacific ancestry genomes. We combined these assemblies to create a pangenome reference, which added 30.6 Mb of novel sequence missing from the Human Pangenome Reference Consortium (HPRC) reference. Mapping short reads to this pangenome reduced variant call errors and yielded more true-positive variants compared to the HPRC and T2T-CHM13 references. This Pacific ancestry pangenome reference serves as a resource to enhance genetic analyses for this underserved population.

Cover crop species influences soil fungal species richness and community structure.

Despite the well documented link between cover cropping and soil microbiology, the influence of specific cover crop species on soil microbes remains poorly understood. We evaluated how soil fungal communities in a no till system respond to four cover crop treatments: no cover crop (REF), cereal ryegrass (CRYE), wild pennycress (WPEN), and a mix of pea, clover, radish, and oat (PCRO). Soil samples were collected from experimental plots following termination of cover crops from depths of 0-2 cm and 2-4 cm where cover crops had significantly increased soil organic matter. There was no significant interaction between soil depth and cover crop treatment on either alpha diversity or beta diversity. All cover crop treatments (CRYE, PCRO, and WPEN) enhanced soil fungal richness but only CRYE enhanced soil fungal diversity and altered the fungal community structure. Soil depth altered the fungal community structure but had no effect on fungal diversity and richness. Genus Fusarium which includes some of the most economically destructive pathogens was more abundant in REF and PCRO treatments compared to CRYE and WPEN. In contrast, genus Mortierella which is known to promote plant health was more abundant in all cover crop treatments relative to the REF. These findings demonstrate that cover cropping can increase soil fungal species richness and alter fungal community structure, potentially promoting the abundance of beneficial fungi and reducing the abundance of some plant pathogens within the genus Fusarium. These effects are dependent on cover crop species, a factor that should be considered when selecting appropriate cover crops for a particular cropping system.

Getting to the root of root-microbe interactions.

Microbial relationships with roots influence many ecosystem functions and nutrient fluxes, including their sometimes-profound effects on plant health and productivity. Fine roots were often classified with a diameter less than 2 mm, but fine roots under that size perform distinct functional roles in the environment. Importantly, two broad functional categories of fine roots are absorptive and transportive, with absorptive fine roots acting as metabolic hotspots for root activity. In two of our recent studies, we have shown that several microbial community characteristics differ between absorptive and transportive fine roots, including composition, abundance, and function, as well as the root metabolome. This highlights a growing recognition within microbial ecology that we must consider fine-scale environmental variability, such as root physiology and morphology, when interpreting microbial patterns. In this commentary, we summarize the findings of our latest article, further speculate on some of these patterns, and suggest future studies for examining decomposition and applying cutting-edge single-cell sequencing techniques.

Response Rates and Nonresponse Bias Among 20 Years of Pediatrician Surveys.

OBJECTIVES: Our objectives were to examine the following: physician survey response rates across a twenty-year period; the impact of a token incentive on response rates; whether survey nonresponse bias is present and if it is associated with response rate; and the impact of a token incentive on nonresponse bias. METHODS: We utilized data from 68 American Academy of Pediatrics (AAP) pediatrician surveys from 2000 to 2019 and an AAP administrative database, which included information for both respondents and non-respondents (target sample). Linear regression examined response rates over time. To assess nonresponse bias, a t-test or Wilcoxon rank test compared respondents and the target sample by age, gender, and U.S. Census region. Linear regression or Spearman correlation examined the association of response rate and nonresponse bias. Interrupted time series analyses tested the introduction of a $2 token incentive on both response rates and nonresponse bias. RESULTS: Overall mean survey response rate was 56.2%. Response rates declined across survey years (ß=-0.58, p<0.001). The $2 incentive generated an 8.7% response rate increase (p<0.001). The respondent groups had more female pediatricians than the target samples (62.5% vs 60.1%, p<0.001). Age nonresponse bias was associated with lower response rates (ß=-0.47, p<0.001). The $2 incentive was associated with nonresponse bias shifts toward older, away from female, and away from Northeastern respondents. CONCLUSIONS: Our study demonstrates an overall decline in pediatrician survey response rates and a meaningful impact of a token incentive on response rates and nonresponse bias, underscoring the importance of measuring nonresponse bias whenever possible.