Single-cell transcriptomics identifies aberrant glomerular angiogenic signalling in the early stages of WT1 kidney disease.

WT1 encodes a podocyte transcription factor whose variants can cause an untreatable glomerular disease in early childhood. Although WT1 regulates many podocyte genes, it is poorly understood which of them are initiators in disease and how they subsequently influence other cell-types in the glomerulus. We hypothesised that this could be resolved using single-cell RNA sequencing (scRNA-seq) and ligand-receptor analysis to profile glomerular cell-cell communication during the early stages of disease in mice harbouring an orthologous human mutation in WT1 (Wt1R394W/+). Podocytes were the most dysregulated cell-type in the early stages of Wt1R394W/+ disease, with disrupted angiogenic signalling between podocytes and the endothelium, including the significant downregulation of transcripts for the vascular factors Vegfa and Nrp1. These signalling changes preceded glomerular endothelial cell loss in advancing disease, a feature also observed in biopsy samples from human WT1 glomerulopathies. Addition of conditioned medium from murine Wt1R394W/+ primary podocytes to wild-type glomerular endothelial cells resulted in impaired endothelial looping and reduced vascular complexity. Despite the loss of key angiogenic molecules in Wt1R394W/+ podocytes, the pro-vascular molecule adrenomedullin was upregulated in Wt1R394W/+ podocytes and plasma and its further administration was able to rescue the impaired looping observed when glomerular endothelium was exposed to Wt1R394W/+ podocyte medium. In comparative analyses, adrenomedullin upregulation was part of a common injury signature across multiple murine and human glomerular disease datasets, whilst other gene changes were unique to WT1 disease. Collectively, our study describes a novel role for altered angiogenic signalling in the initiation of WT1 glomerulopathy. We also identify adrenomedullin as a proangiogenic factor, which despite being upregulated in early injury, offers an insufficient protective response due to the wider milieu of dampened vascular signalling that results in endothelial cell loss in later disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

H2S Donor GYY4137 Mitigates sFlt-1-Induced Hypertension and Vascular Dysfunction in Pregnant Rats.

BACKGROUND: Gestational hypertension, often associated with elevated soluble Fms-related receptor tyrosine kinase 1 (sFlt-1), poses significant risks to both maternal and fetal health. Hydrogen sulfide (H2S), a gasotransmitter, has demonstrated blood pressure-lowering effects in hypertensive animals and humans. However, its role in pregnancy-induced hypertension remains unclear. OBJECTIVE: This study aimed to investigate the impact of GYY4137, a slow-release H2S donor, on sFlt-1-induced hypertension in pregnant rats and examine the underlying mechanisms. METHODS: Pregnant rats were administered sFlt-1 (6 µg/kg/day, intravenously) or vehicle from gestation day (GD) 12 to 20. A subset of these groups received GYY4137 (an H2S donor, 50 mg/kg/day, subcutaneously) from GD 16 to 20. Serum H2S levels, mean arterial blood pressure (CODA tail-cuff), uterine artery blood flow (ultrasonography), vascular reactivity to vasopressors and endothelial-dependent relaxation (myography), endothelial nitric oxide synthase (eNOS) protein expression in uterine arteries (Western blotting) were assessed. In addition, maternal weight gain, as well as fetal and placental weights, were measured. RESULTS: Elevated sFlt-1 reduced both maternal weight gain and serum H2S levels. GYY4137 treatment restored both weight gain and H2S levels in sFlt-1 dams. sFlt-1 increased mean arterial pressure and decreased uterine artery blood flow in pregnant rats. However, treatment with GYY4137 normalized blood pressure and restored uterine blood flow in sFlt-1 dams. sFlt-1 dams exhibited heightened vasoconstriction to phenylephrine and GYY4137 significantly mitigated the exaggerated vascular contraction. Notably, sFlt-1 impaired endothelium-dependent relaxation, while GYY4137 attenuated this impairment by upregulating eNOS protein levels and enhancing vasorelaxation in uterine arteries. GYY4137 mitigated sFlt-1-induced fetal growth restriction. CONCLUSION: sFlt-1 mediated hypertension is associated with decreased H2S levels. Replenishing H2S with the donor GYY4137 mitigates hypertension and improves vascular function and fetal growth outcomes. This suggests modulation of H2S could offer a novel therapeutic strategy for managing gestational hypertension and adverse fetal effects.

Translational Research Techniques for the Facial Plastic Surgeon: An Overview.

The field of facial plastic and reconstructive surgery (FPRS) is an incredibly diverse, multispecialty field that seeks innovative and novel solutions for the management of physical defects on the head and neck. To aid in the advancement of medical and surgical treatments for these defects, there has been a recent emphasis on the importance of translational research. With recent technological advancements, there are now a myriad of research techniques that are widely accessible for physician and scientist use in translational research. Such techniques include integrated multiomics, advanced cell culture and microfluidic tissue models, established animal models, and emerging computer models generated using bioinformatics. This study discusses these various research techniques and how they have and can be used for research in the context of various important diseases within the field of FPRS.

The Pathophysiological Role of Thymosin ß4 in the Kidney Glomerulus.

Diseases affecting the glomerulus, the filtration unit of the kidney, are a major cause of chronic kidney disease. Glomerular disease is characterised by injury of glomerular cells and is often accompanied by an inflammatory response that drives disease progression. New strategies are needed to slow the progression to end-stage kidney disease, which requires dialysis or transplantation. Thymosin ß4 (Tß4), an endogenous peptide that sequesters G-actin, has shown potent anti-inflammatory function in experimental models of heart, kidney, liver, lung, and eye injury. In this review, we discuss the role of endogenous and exogenous Tß4 in glomerular disease progression and the current understanding of the underlying mechanisms.

ICTV Virus Taxonomy Profile: Hepadnaviridae.

The family Hepadnaviridae comprises small enveloped viruses with a partially double-stranded DNA genome of 3.0-3.4 kb. All family members express three sets of proteins (preC/C, polymerase and preS/S) and replication involves reverse transcription within nucleocapsids in the cytoplasm of hepatocytes. Hepadnaviruses are hepatotropic and infections may be transient or persistent. There are five genera: Parahepadnavirus, Metahepadnavirus, Herpetohepadnavirus, Avihepadnavirus and Orthohepadnavirus. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Hepadnaviridae, which is available at ictv.global/report/hepadnaviridae.

ICTV Virus Taxonomy Profile: Deltavirus.

Hepatitis delta virus, the only member of the only species in the genus Deltavirus, is a unique human pathogen. Its ~1.7 kb circular negative-sense RNA genome encodes a protein, hepatitis delta antigen, which occurs in two forms, small and large, both with unique functions. Hepatitis delta virus uses host RNA polymerase II to replicate via double rolling circle RNA synthesis. Newly synthesized linear RNAs are circularized after autocatalytic cleavage and ligation. Hepatitis delta virus requires the envelope of the helper virus, hepatitis B virus (family Hepadnaviridae), to produce infectious particles. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of Deltavirus which is available at www.ictv.global/report/deltavirus.

HBV DNA Integration and Clonal Hepatocyte Expansion in Chronic Hepatitis B Patients Considered Immune Tolerant.

BACKGROUND & AIMS: Chronic infection with hepatitis B virus (HBV) progresses through different phases. The first, called the immune-tolerant phase, has been associated with a lack of disease activity. We examined HBV-DNA integration, clonal hepatocyte expansion, HBV antigen expression, and HBV-specific immune responses in patients in the immune-tolerant phase to assess whether this designation is appropriate or if there is evidence of disease activity. METHODS: We studied HBV-DNA integration, clonal hepatocyte expansion, and expression of hepatitis B surface antigen and core antigen in liver tissues from 26 patients with chronic HBV infection (ages, 14-39 y); 9 patients were positive for hepatitis B e antigen (HBeAg) in the immune-tolerant phase and were matched for age with 10 HBeAg-positive patients with active disease and 7 HBeAg-negative patients with active disease. Peripheral blood samples were collected and HBV-specific T cells were quantified for each group. RESULTS: Detection of HBV antigens differed among groups. However, unexpectedly high numbers of HBV-DNA integrations, randomly distributed among chromosomes, were detected in all groups. Clonal hepatocyte expansion in patients considered immune tolerant also was greater than expected, potentially in response to hepatocyte turnover mediated by HBV-specific T cells, which were detected in peripheral blood cells from patients in all phases of infection. CONCLUSIONS: We measured HBV-specific T cells, HBV-DNA integration, and clonal hepatocyte expansion in different disease phases of young patients with chronic hepatitis B, with emphasis on the so-called immune-tolerant phase. A high level of HBV-DNA integration and clonal hepatocyte expansion in patients considered immune tolerant indicated that hepatocarcinogenesis could be underway-even in patients with early stage chronic HBV infection. Our findings do not support the concepts that this phase is devoid of markers of disease progression or that an immune response has not been initiated. We propose that this early phase be called a high-replication, low-inflammation stage. The timing of therapeutic interventions to minimize further genetic damage to the hepatocyte population should be reconsidered.

Effects of pair bonding on dopamine D1 receptors in monogamous male titi monkeys (Callicebus cupreus).

Pair bonding leads to increases in dopamine D1 receptor (D1R) binding in the nucleus accumbens of monogamous prairie voles. In the current study, we hypothesized that there is similar up-regulation of D1R in a monogamous primate, the titi monkey (Callicebus cupreus). Receptor binding of the D1R antagonist [11 C]-SCH23390 was measured in male titi monkeys using PET scans before and after pairing with a female. We found that within-subject analyses of pairing show significant increases in D1R binding in the lateral septum, but not the nucleus accumbens, caudate, putamen, or ventral pallidum. The lateral septum is involved in a number of processes that may contribute to social behavior, including motivation, affect, reward, and reinforcement. This region also plays a role in pair bonding and paternal behavior in voles. Our observations of changes in D1R in the lateral septum, but not the nucleus accumbens, suggest that there may be broadly similar dopaminergic mechanisms underlying pair bonding across mammalian species, but that the specific changes to neural circuitry differ. This study is the first research to demonstrate neuroplasticity of the dopamine system following pair bonding in a non-human primate; however, substantial variability in the response to pairing suggests the utility of further research on the topic.

HBV replication, pathobiology and therapy: Unanswered questions.

This volume explores these and other issues of relevance to our understanding of the HBV life cycle and clinical management of chronic HBV infections. The ultimate goals of these studies is not just to obtain a more precise understanding of the HBV life cycle, but to also acquire an understanding that will lead to more effective treatments for an infection and pathogenic process that currently causes ∼500,000 to 1,000,000 deaths per year.

Towards an HBV cure: state-of-the-art and unresolved questions--report of the ANRS workshop on HBV cure.

HBV infection is a major cause of liver cirrhosis and hepatocellular carcinoma. Although HBV infection can be efficiently prevented by vaccination, and treatments are available, to date there is no reliable cure for the >240 million individuals that are chronically infected worldwide. Current treatments can only achieve viral suppression, and lifelong therapy is needed in the majority of infected persons. In the framework of the French National Agency for Research on AIDS and Viral Hepatitis 'HBV Cure' programme, a scientific workshop was held in Paris in June 2014 to define the state-of-the-art and unanswered questions regarding HBV pathobiology, and to develop a concerted strategy towards an HBV cure. This review summarises our current understanding of HBV host-interactions leading to viral persistence, as well as the roadblocks to be overcome to ultimately address unmet medical needs in the treatment of chronic HBV infection.

Using Ipratropium Bromide Nasal Spray Response as a Screening Tool in the Diagnostic Workup of Cerebrospinal Fluid Rhinorrhea.

OBJECTIVES: Unilateral clear thin rhinorrhea (UCTR) can be concerning for a nasal cerebrospinal fluid (CSF) leak. Beta-2 transferrin electrophoresis has been the gold standard for initial non-invasive confirmatory testing for CSF rhinorrhea, but there can be issues with fluid collection and testing errors. Ipratropium bromide nasal spray (IBNS) is highly effective at reducing rhinitis-related rhinorrhea, and should presumably not resolve CSF rhinorrhea. This study assessed whether different clinical features and IBNS response helped predict presence or absence of CSF rhinorrhea. METHODS: A prospective cohort study was conducted where all patients with UCTR had nasal fluid tested for beta-2 transferrin, and were prescribed 0.06% IBNS. Patients were diagnosed with CSF rhinorrhea or other rhinologic conditions. Clinical variables like IBNS response (rhinorrhea reduction), positional worsening, salty taste, postoperative state, female gender, and body-mass index were assessed for their ability to predict CSF rhinorrhea. Sensitivity, specificity, and predictive values and odds ratios were calculated for all clinical variables. RESULTS: Twenty patients had CSF rhinorrhea, and 53 had non-CSF etiologies. Amongst clinical variables assessed for predicting CSF absence or presence, significant associations were shown for IBNS response (OR = 844.66, p = 0.001), positional rhinorrhea worsening (OR = 8.22, p = 0.049), and body-mass index ≥30 (OR = 2.92, p = 0.048). IBNS response demonstrated 96% sensitivity and 100% specificity, and 100% positive and 91% negative predictive values for predicting CSF rhinorrhea. CONCLUSIONS: In patients with UCTR, 0.06% IBNS response is an excellent screening tool for excluding CSF rhinorrhea, and should be considered in the diagnostic workup of CSF rhinorrhea. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:56-61, 2024.

Early Management of Paediatric Wrist and Forearm Fractures in a Busy District General Hospital Emergency Department: A Retrospective Cohort Comparison Study and Audit of BOAST Guidelines.

INTRODUCTION: In response to the strain that the COVID-19 pandemic put on hospitals in the UK, the British Orthopaedic Association, in May 2021, set out British Orthopaedic Association Standards for Trauma and Orthopaedics (BOAST) guidelines for the early management of distal forearm fractures in children. Following this, a local pathway was introduced at our Trust to manage these injuries in the Emergency Department (ED). The aim of this audit was to monitor compliance with the BOAST guidelines and compare the practice with a similar pre-COVID cohort. METHODS: A fixed-date retrospective cohort study was conducted that included cases that presented to the emergency department during a six-month period (August 1, 2021 to January 31, 2022). Data was analysed for rates of primary ED manipulation, documentation of consent and neurovascular status in the notes, orthogonal X-ray data, time till the clinic follow-up, theatre time saved and complications. The ED fracture manipulation rate was also compared with another similar pre-COVID cohort (August 1, 2019 to January 31, 2020) to look for any improvement in the practice. RESULTS: A total of 86.31% cases were found to have primary fracture manipulation in the ED following the introduction of Trust guidelines in accordance with the BOAST recommendations. This is an improvement in comparison to the 31.94% fracture manipulation rate before the COVID pandemic. CONCLUSION: Implementation of the Trust pathway in accordance with the BOAST guidelines along with staff education has standardized the practice at our Trust. It saved approximately 63 hours of trauma theatre time for the six-month data collection period. Our findings also suggest that this has favourable outcomes for the patients with no complications.

Systematic review of errors on beta-2 transferrin gel electrophoresis testing of rhinorrhea and otorrhea.

BACKGROUND: Beta-2 transferrin (B2-Tf) gel electrophoresis (GE) is the preferred non-invasive diagnostic modality for confirming cerebrospinal fluid (CSF) in body fluids. While B2-Tf GE testing is highly sensitive and specific for CSF, false-positive (FP) and false-negative (FN) results can lead to diagnostic and therapeutic dilemmas. Several series have demonstrated potential causes of false B2-Tf GE results, but few studies have reported reasons for these errors. The purpose of this systematic review was to describe sources of B2-Tf GE errors. METHODS: A systematic review was performed by searching OVID, EMBASE, and Web of Science databases for B2-Tf GE studies. After applying exclusion criteria, original research studies directly addressing erroneous B2-Tf GE results underwent qualitative analysis. RESULTS: Of the 243 abstracts screened, 71 underwent full-text review and 18 studies reporting B2-Tf GE errors were included for analysis. There were 15 potential FPs, 12 actual FPs, 12 potential FNs, 19 actual FNs, and 14 indeterminate results. There were also 246 potentially indeterminate results from in vitro studies. Reasons for B2-Tf GE errors included serum transferrin alterations (n = 17; all potential), infection related (n = 13; 9 potential), orbital or salivary contamination (n = 2; 1 potential), and collection related (n = 255; 246 potential). There were 31 false or indeterminate results with unspecified reasons. There were no reported errors due to laboratory processing. CONCLUSIONS: Multiple potential or actual reasons for false or indeterminate results have been reported for B2-Tf GE testing of rhinorrhea and otorrhea. Future studies should explore reasons for B2-Tf testing errors and how these may affect clinical decision making.

Identification of disubstituted sulfonamide compounds as specific inhibitors of hepatitis B virus covalently closed circular DNA formation.

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) plays a central role in viral infection and persistence and is the basis for viral rebound after the cessation of therapy, as well as the elusiveness of a cure even after extended treatment. Therefore, there is an urgent need for the development of novel therapeutic agents that directly target cccDNA formation and maintenance. By employing an innovative cell-based cccDNA assay in which secreted HBV e antigen is a cccDNA-dependent surrogate, we screened an in-house small-molecule library consisting of 85,000 drug-like compounds. Two structurally related disubstituted sulfonamides (DSS), termed CCC-0975 and CCC-0346, emerged and were confirmed as inhibitors of cccDNA production, with low micromolar 50% effective concentrations (EC(50)s) in cell culture. Further mechanistic studies demonstrated that DSS compound treatment neither directly inhibited HBV DNA replication in cell culture nor reduced viral polymerase activity in the in vitro endogenous polymerase assay but synchronously reduced the levels of HBV cccDNA and its putative precursor, deproteinized relaxed circular DNA (DP-rcDNA). However, DSS compounds did not promote the intracellular decay of HBV DP-rcDNA and cccDNA, suggesting that the compounds interfere primarily with rcDNA conversion into cccDNA. In addition, we demonstrated that CCC-0975 was able to reduce cccDNA biosynthesis in duck HBV-infected primary duck hepatocytes. This is the first attempt, to our knowledge, to identify small molecules that target cccDNA formation, and DSS compounds thus potentially serve as proof-of-concept drug candidates for development into therapeutics to eliminate cccDNA from chronic HBV infection.

Differences in titi monkey (Callicebus cupreus) social bonds affect arousal, affiliation, and response to reward.

Titi monkeys (Callicebus cupreus) are a monogamous, New World primate. Adult pair-mates form a bidirectional social bond and offspring form a selective unidirectional bond to their father. Some of the neurobiology involved in social bonds and maternal behavior is similar to the neural circuitry involved in nonsocial reward. Due to these overlapping mechanisms, social states may affect responses to external rewarding stimuli. We sought to determine whether having a social attachment, and/or being in the presence of that attachment figure, can affect an individual's response to a rewarding stimulus. In addition, we compared affiliative bonds between pair-mates to those between offspring and fathers. Eighteen adult male titi monkeys were either living alone (Lone), with a female pair-mate (Paired), or with the natal group (Natal; N = 6/condition). Each individual went through eight 30-min preference tests for a sweet substance, Tang. For Paired and Natal males, half of the test sessions were with their attachment figure and half were alone. Lone males were always tested alone. Preference scores for Tang, time spent drinking, affiliative, and arousal behaviors were measured. Paired and Natal males emitted significantly more isolation peeps and locomoted more when tested alone compared to when tested with their attachment figure, and paired males engaged in more affiliative behavior than Natal males. Lone males engaged in significantly more behaviors indicative of behavioral arousal such as locomotion and piloerection compared to Paired and Natal males. Finally, Paired males drank significantly more Tang and had a significantly greater preference for Tang compared to Lone and Natal males. These results indicate that offspring undergo a behavioral separation response upon separation from their father that persists into adulthood, Lone males are more behaviorally reactive, and that living with an attachment figure and the type of attachment relationship result in different responses to a rewarding sweet stimulus.

Expected Costs of Primary Dental Treatments and Endoscopic Sinus Surgery for Odontogenic Sinusitis.

OBJECTIVES: Treatment of odontogenic sinusitis (ODS) due to apical periodontitis (AP) is highly successful when both dental treatment and endoscopic sinus surgery (ESS) are performed. Variation exists in the literature with regard to types and timing of dental treatments and ESS when managing ODS. This study modeled expected costs of different primary dental and sinus surgical treatment pathways for ODS due to AP. STUDY DESIGN: Decision-tree economic model. METHODS: Decision-tree models were created based on cost and treatment success probabilities. Using Medicare and consumer online databases, cost data were obtained for the following dental and sinus surgical treatments across the United States: root canal therapy (RCTx), revision RCTx, apicoectomy, extraction, dental implant, bone graft, and ESS (maxillary, ± anterior ethmoid, ± frontal). A literature review was performed to determine probabilities of dental and sinus disease resolution after different dental treatments. Expected costs were determined for primary dental extraction, RCTx, and ESS pathways, and sensitivity analyses were performed. RESULTS: Expected costs for the three different primary treatment pathways when dental care was in-network and all diseased sinuses opened during ESS were as follows: dental extraction ($4,753.83), RCTx ($4,677.34), and ESS ($7,319.85). CONCLUSIONS: ODS due to AP can be successfully treated with primary dental treatments, but ESS is still frequently required. Expected costs of primary dental extraction and RCTx were roughly equal. Primary ESS had a higher expected cost, but may still be preferred in patients with prominent sinonasal symptoms. Patients' insurance coverage may also impact decision-making. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1346-1355, 2022.

Systemic gene therapy with thymosin ß4 alleviates glomerular injury in mice.

Plasma ultrafiltration in the kidney occurs across glomerular capillaries, which are surrounded by epithelial cells called podocytes. Podocytes have a unique shape maintained by a complex cytoskeleton, which becomes disrupted in glomerular disease resulting in defective filtration and albuminuria. Lack of endogenous thymosin ß4 (TB4), an actin sequestering peptide, exacerbates glomerular injury and disrupts the organisation of the podocyte actin cytoskeleton, however, the potential of exogenous TB4 therapy to improve podocyte injury is unknown. Here, we have used Adriamycin (ADR), a toxin which injures podocytes and damages the glomerular filtration barrier leading to albuminuria in mice. Through interrogating single-cell RNA-sequencing data of isolated glomeruli we demonstrate that ADR injury results in reduced levels of podocyte TB4. Administration of an adeno-associated viral vector encoding TB4 increased the circulating level of TB4 and prevented ADR-induced podocyte loss and albuminuria. ADR injury was associated with disorganisation of the podocyte actin cytoskeleton in vitro, which was ameliorated by treatment with exogenous TB4. Collectively, we propose that systemic gene therapy with TB4 prevents podocyte injury and maintains glomerular filtration via protection of the podocyte cytoskeleton thus presenting a novel treatment strategy for glomerular disease.

Clonal expansion of normal-appearing human hepatocytes during chronic hepatitis B virus infection.

Chronic hepatitis B virus (HBV) infections are associated with persistent immune killing of infected hepatocytes. Hepatocytes constitute a largely self-renewing population. Thus, immune killing may exert selective pressure on the population, leading it to evolve in order to survive. A gradual course of hepatocyte evolution toward an HBV-resistant state is suggested by the substantial decline in the fraction of infected hepatocytes that occurs during the course of chronic infections. Consistent with hepatocyte evolution, clones of >1,000 hepatocytes develop postinfection in the noncirrhotic livers of chimpanzees chronically infected with HBV and of woodchucks infected with woodchuck hepatitis virus (W. S. Mason, A. R. Jilbert, and J. Summers, Proc. Natl. Acad. Sci. U. S. A. 102:1139-1144, 2005; W. S. Mason et al., J. Virol. 83:8396-8408, 2009). The present study was carried out to determine (i) if extensive clonal expansion of hepatocytes also occurred in human HBV carriers, particularly in the noncirrhotic liver, and (ii) if clonal expansion included normal-appearing hepatocytes, not just hepatocytes that appear premalignant. Host DNA extracted from fragments of noncancerous liver, collected during surgical resection of hepatocellular carcinoma (HCC), was analyzed by inverse PCR for randomly integrated HBV DNA as a marker of expanding hepatocyte lineages. This analysis detected extensive clonal expansion of hepatocytes, as previously found in chronically infected chimpanzees and woodchucks. Tissue sections were stained with hematoxylin and eosin (H&E), and DNA was extracted from the adjacent section for inverse PCR to detect integrated HBV DNA. This analysis revealed that clonal expansion can occur among normal-appearing human hepatocytes.