Elicitation of broadly protective sarbecovirus immunity by receptor-binding domain nanoparticle vaccines.

Understanding vaccine-elicited protection against SARS-CoV-2 variants and other sarbecoviruses is key for guiding public health policies. We show that a clinical stage multivalent SARS-CoV-2 spike receptor-binding domain nanoparticle (RBD-NP) vaccine protects mice from SARS-CoV-2 challenge after a single immunization, indicating a potential dose-sparing strategy. We benchmarked serum neutralizing activity elicited by RBD-NPs in non-human primates against a lead prefusion-stabilized SARS-CoV-2 spike (HexaPro) using a panel of circulating mutants. Polyclonal antibodies elicited by both vaccines are similarly resilient to many RBD residue substitutions tested, although mutations at and surrounding position 484 have negative consequences for neutralization. Mosaic and cocktail nanoparticle immunogens displaying multiple sarbecovirus RBDs elicit broad neutralizing activity in mice and protect mice against SARS-CoV challenge even in the absence of SARS-CoV RBD in the vaccine. This study provides proof of principle that multivalent sarbecovirus RBD-NPs induce heterotypic protection and motivates advancing such broadly protective sarbecovirus vaccines to the clinic.

Single-cell analysis of lymphatic endothelial cell fate specification and differentiation during zebrafish development.

During development, the lymphatic vasculature forms as a second network derived chiefly from blood vessels. The transdifferentiation of embryonic venous endothelial cells (VECs) into lymphatic endothelial cells (LECs) is a key step in this process. Specification, differentiation and maintenance of LEC fate are all driven by the transcription factor Prox1, yet the downstream mechanisms remain to be elucidated. We here present a single-cell transcriptomic atlas of lymphangiogenesis in zebrafish, revealing new markers and hallmarks of LEC differentiation over four developmental stages. We further profile single-cell transcriptomic and chromatin accessibility changes in zygotic prox1a mutants that are undergoing a LEC-VEC fate shift. Using maternal and zygotic prox1a/prox1b mutants, we determine the earliest transcriptomic changes directed by Prox1 during LEC specification. This work altogether reveals new downstream targets and regulatory regions of the genome controlled by Prox1 and presents evidence that Prox1 specifies LEC fate primarily by limiting blood vascular and haematopoietic fate. This extensive single-cell resource provides new mechanistic insights into the enigmatic role of Prox1 and the control of LEC differentiation in development.

TMEM161B regulates cerebral cortical gyration, Sonic Hedgehog signaling, and ciliary structure in the developing central nervous system.

Sonic hedgehog signaling regulates processes of embryonic development across multiple tissues, yet factors regulating context-specific Shh signaling remain poorly understood. Exome sequencing of families with polymicrogyria (disordered cortical folding) revealed multiple individuals with biallelic deleterious variants in TMEM161B, which encodes a multi-pass transmembrane protein of unknown function. Tmem161b null mice demonstrated holoprosencephaly, craniofacial midline defects, eye defects, and spinal cord patterning changes consistent with impaired Shh signaling, but were without limb defects, suggesting a CNS-specific role of Tmem161b. Tmem161b depletion impaired the response to Smoothened activation in vitro and disrupted cortical histogenesis in vivo in both mouse and ferret models, including leading to abnormal gyration in the ferret model. Tmem161b localizes non-exclusively to the primary cilium, and scanning electron microscopy revealed shortened, dysmorphic, and ballooned ventricular zone cilia in the Tmem161b null mouse, suggesting that the Shh-related phenotypes may reflect ciliary dysfunction. Our data identify TMEM161B as a regulator of cerebral cortical gyration, as involved in primary ciliary structure, as a regulator of Shh signaling, and further implicate Shh signaling in human gyral development.

Endocardial identity is established during early somitogenesis by Bmp signalling acting upstream of npas4l and etv2.

The endocardium plays important roles in the development and function of the vertebrate heart; however, few molecular markers of this tissue have been identified and little is known about what regulates its differentiation. Here, we describe the Gt(SAGFF27C); Tg(4xUAS:egfp) line as a marker of endocardial development in zebrafish. Transcriptomic comparison between endocardium and pan-endothelium confirms molecular distinction between these populations and time-course analysis suggests differentiation as early as eight somites. To investigate what regulates endocardial identity, we employed npas4l, etv2 and scl loss-of-function models. Endocardial expression is lost in npas4l mutants, significantly reduced in etv2 mutants and only modestly affected upon scl loss-of-function. Bmp signalling was also examined: overactivation of Bmp signalling increased endocardial expression, whereas Bmp inhibition decreased expression. Finally, epistasis experiments showed that overactivation of Bmp signalling was incapable of restoring endocardial expression in etv2 mutants. By contrast, overexpression of either npas4l or etv2 was sufficient to rescue endocardial expression upon Bmp inhibition. Together, these results describe the differentiation of the endocardium, distinct from vasculature, and place npas4l and etv2 downstream of Bmp signalling in regulating its differentiation.

Flagellin-modulated inflammasome pathways characterize the human alveolar macrophage response to Burkholderia pseudomallei, a lung-tropic pathogen.

Melioidosis is an emerging tropical infection caused by inhalation, inoculation, or ingestion of the flagellated, facultatively intracellular pathogen Burkholderia pseudomallei. The melioidosis case fatality rate is often high, and pneumonia, the most common presentation, doubles the risk of death. The alveolar macrophage is a sentinel pulmonary host defense cell, but the human alveolar macrophage in B. pseudomallei infection has never been studied. The objective of this study was to investigate the host-pathogen interaction of B. pseudomallei infection with the human alveolar macrophage and to determine the role of flagellin in modulating inflammasome-mediated pathways. We found that B. pseudomallei infects primary human alveolar macrophages but is gradually restricted in the setting of concurrent cell death. Electron microscopy revealed cytosolic bacteria undergoing division, indicating that B. pseudomallei likely escapes the alveolar macrophage phagosome and may replicate in the cytosol, where it triggers immune responses. In paired human blood monocytes, uptake and intracellular restriction of B. pseudomallei are similar to those observed in alveolar macrophages, but cell death is reduced. The alveolar macrophage cytokine response to B. pseudomallei is characterized by marked interleukin (IL)-18 secretion compared to monocytes. Both cytotoxicity and IL-18 secretion in alveolar macrophages are partially flagellin dependent. However, the proportion of IL-18 release that is driven by flagellin is greater in alveolar macrophages than in monocytes. These findings suggest differential flagellin-mediated inflammasome pathway activation in the human alveolar macrophage response to B. pseudomallei infection and expand our understanding of intracellular pathogen recognition by this unique innate immune lung cell.

The zebrafish grime mutant uncovers an evolutionarily conserved role for Tmem161b in the control of cardiac rhythm.

The establishment of cardiac function in the developing embryo is essential to ensure blood flow and, therefore, growth and survival of the animal. The molecular mechanisms controlling normal cardiac rhythm remain to be fully elucidated. From a forward genetic screen, we identified a unique mutant, grime, that displayed a specific cardiac arrhythmia phenotype. We show that loss-of-function mutations in tmem161b are responsible for the phenotype, identifying Tmem161b as a regulator of cardiac rhythm in zebrafish. To examine the evolutionary conservation of this function, we generated knockout mice for Tmem161b. Tmem161b knockout mice are neonatal lethal and cardiomyocytes exhibit arrhythmic calcium oscillations. Mechanistically, we find that Tmem161b is expressed at the cell membrane of excitable cells and live imaging shows it is required for action potential repolarization in the developing heart. Electrophysiology on isolated cardiomyocytes demonstrates that Tmem161b is essential to inhibit Ca2+ and K+ currents in cardiomyocytes. Importantly, Tmem161b haploinsufficiency leads to cardiac rhythm phenotypes, implicating it as a candidate gene in heritable cardiac arrhythmia. Overall, these data describe Tmem161b as a highly conserved regulator of cardiac rhythm that functions to modulate ion channel activity in zebrafish and mice.

Evaluation of a Natural Language Processing Approach to Identify Diagnostic Errors and Analysis of Safety Learning System Case Review Data: Retrospective Cohort Study.

BACKGROUND: Diagnostic errors are an underappreciated cause of preventable mortality in hospitals and pose a risk for severe patient harm and increase hospital length of stay. OBJECTIVE: This study aims to explore the potential of machine learning and natural language processing techniques in improving diagnostic safety surveillance. We conducted a rigorous evaluation of the feasibility and potential to use electronic health records clinical notes and existing case review data. METHODS: Safety Learning System case review data from 1 large health system composed of 10 hospitals in the mid-Atlantic region of the United States from February 2016 to September 2021 were analyzed. The case review outcome included opportunities for improvement including diagnostic opportunities for improvement. To supplement case review data, electronic health record clinical notes were extracted and analyzed. A simple logistic regression model along with 3 forms of logistic regression models (ie, Least Absolute Shrinkage and Selection Operator, Ridge, and Elastic Net) with regularization functions was trained on this data to compare classification performances in classifying patients who experienced diagnostic errors during hospitalization. Further, statistical tests were conducted to find significant differences between female and male patients who experienced diagnostic errors. RESULTS: In total, 126 (7.4%) patients (of 1704) had been identified by case reviewers as having experienced at least 1 diagnostic error. Patients who had experienced diagnostic error were grouped by sex: 59 (7.1%) of the 830 women and 67 (7.7%) of the 874 men. Among the patients who experienced a diagnostic error, female patients were older (median 72, IQR 66-80 vs median 67, IQR 57-76; P=.02), had higher rates of being admitted through general or internal medicine (69.5% vs 47.8%; P=.01), lower rates of cardiovascular-related admitted diagnosis (11.9% vs 28.4%; P=.02), and lower rates of being admitted through neurology department (2.3% vs 13.4%; P=.04). The Ridge model achieved the highest area under the receiver operating characteristic curve (0.885), specificity (0.797), positive predictive value (PPV; 0.24), and F1-score (0.369) in classifying patients who were at higher risk of diagnostic errors among hospitalized patients. CONCLUSIONS: Our findings demonstrate that natural language processing can be a potential solution to more effectively identifying and selecting potential diagnostic error cases for review and therefore reducing the case review burden.

A quality improvement approach to improving recognition of Maori tamariki (children) and assessing barriers to culturally responsive care in a paediatric ward setting.

BACKGROUND: Health inequity persists in Aotearoa (New Zealand) and internationally amongst most indigenous peoples. To address these health inequities, countries need to contend with the ramifications of entrenched historical, cultural and systemic failures. Within Aotearoa part of the solution to rectifying persistent health inequities lies in shifting everyday healthcare practices towards a more culturally responsive, patient-centred approach that utilises Maori knowledge and principles. Although the need for culturally responsive services in healthcare settings is clearly evident, most practitioners struggle with the challenge of creating a culturally safe environment. Further to these challenges, there are issues related to accurate recognition of ethnicity within the time constraints of an overwrought hospital environment. Within this environment, the correct identification of ethnicity is a fundamental step in the process of moving towards culturally responsive and more inclusive care. METHOD: The research was concerned with indigenous Maori patients being consistently and correctly identified so that they might receive culturally appropriate interaction and treatment. The research specifically focused on the impact of introducing a customised sticker prompt on the front cover of clinical notes of Maori tamariki (children) to assist with correct ethnicity identification. Surveys were conducted on the paediatric ward over a 3-week period, prior to and during the intervention to evaluate the effect of the customised stickers. This study sought to (1) assess the efficacy of a sticker to improve recognition of Maori tamariki (children), (2) examine key barriers to identifying ethnicity and (3) identify wider impacts of a sticker prompt on clinical practice. RESULTS: Results showed wide ranging positive impacts on clinical practice and culturally responsive care. Sixty-four per cent of participants indicated that the stickers were a useful tool to improve identification of Maori tamariki. Respondents reported increased accuracy of identifying patients by ethnicity, as well as improved awareness of existing ethnicity documentation, and increased engagement regarding cultural needs and ethnicity. CONCLUSIONS: This study identified that sticker prompts are a useful tool for healthcare workers to improve recognition and awareness of ethnicity and to increase dialogue around cultural needs. The stickers led to increased consideration of the wider elements of holistic wellbeing and therefore improved culturally responsive care for Maori tamariki.

Reported impact and protective factors of the care partner role during persistent critical illness: a content analysis.

BACKGROUND: Patients with persistent critical illness experience prolonged multi-system morbidity, functional impairments, and chronic conditions. As a result, these patients have prolonged intensive care unit admissions. If discharged, they return home with long-term medical dependencies. Care partners take on a variety of physical, mental health, cognitive, and social roles to support the provision of care for these patients. There is limited evidence, however, of the impact of being a care partner for this patient population during hospitalization. METHODS: A qualitative descriptive study was conducted to explore the impact care provision on care partners for patients experiencing persistent critical illness. Patients who have or have had persistent critical illness and care partners were recruited from two inpatient units in a single community academic hospital in Toronto, Canada to participate in semi-structured interviews. Data was analyzed using a team-based inductive content analysis. RESULTS: Seven (43.8%) participants were patient survivors, and nine (56.3%) were care partners. Patients and care partners reported physical, socio-emotional, and social stress as impacts of care provision during persistent critical illness hospitalization. Care partners identified several protective strategies that they used to mitigate the impacts of care provision on them such as seeking external mental health support and boundary setting. Features of formalized and care partner programs were also identified and suggest that these programs can be protective of care partner values, mitigate feelings of helplessness and stress, and may improve relationships between the family members who are in the care partner role and the healthcare team. CONCLUSIONS: This study identified physical, socio-emotional, and social stress related impacts of care provision on care partners of patients with persistent critical illness during hospitalization. Additionally, this study identified protective factors initiated by care partners to mitigate the reported stresses of the role, as well as protective features of a care partner program. The results provide a better understanding supportive features of care partner programs that are specific to the experiences and needs of persistent critical illness and add to the growing body of evidence about how to provide equitable access to care during and post hospitalization.

How do people with intellectual disabilities understand friendship? A systematic meta-synthesis.

BACKGROUND: Previous systematic reviews of the relationships of people with intellectual disabilities have included consideration of intimate relationships. In this paper, we report a systematic review of papers describing friendship only. METHOD: A systematic qualitative meta-synthesis of the research exploring experiences of friendship as reported by people with intellectual disabilities. RESULTS: Seven papers met the inclusion criteria for analysis. Three superordinate themes were identified. (1) Reciprocity, 'Someone who helps me, and I help them'. (2) The building blocks of friendships, 'I can tell her some secrets'. (3) Managing friendship difficulties, 'In real life it's much harder'. CONCLUSION: People with intellectual disabilities value friendship and actively engage in reciprocal exchanges. We explore the strengths and limitations of current research, clinical implications, and directions for future research.

Commentary: Engagement for Research and Quality Improvement - More Than Just Words.

We reflect on the paper from Hahn-Goldberg et al. (2024) who shared key learnings from a pan-Canadian quality improvement (QI) and patient engagement care transition initiative called Bridge-to-Home. In considering the approach and outcomes presented in their paper, we have generated reflections and practical suggestions on how to amplify engagement work even further: (1) patient engagement and QI are about relationships; (2) seamlessly implementing complex interventions across siloed organizations continues to be a challenge, which engagement alone cannot solve; (3) it is time for a paradigm shift; (4) QI is about human behaviour change and is inherently messy; and (5) embedding fulsome evaluation of engagement is essential.

FlgM is required to evade NLRC4-mediated host protection against flagellated Salmonella.

Salmonella enterica serovar Typhimurium is a leading cause of gastroenteritis worldwide and a deadly pathogen in children, immunocompromised patients, and the elderly. Salmonella induces innate immune responses through the NLRC4 inflammasome, which has been demonstrated to have distinct roles during systemic and mucosal detections of flagellin and non-flagellin molecules. We hypothesized that NLRC4 recognition of Salmonella flagellin is the dominant protective pathway during infection. To test this hypothesis, we used wild-type, flagellin-deficient, and flagellin-overproducing Salmonella to establish the role of flagellin in mediating NLRC4-dependent host resistance during systemic and mucosal infections in mice. We observed that during the systemic phase of infection, Salmonella efficiently evades NLRC4-mediated innate immunity. During mucosal Salmonella infection, flagellin recognition by the NLRC4 inflammasome pathway is the dominant mediator of protective innate immunity. Deletion of flgM results in constitutive expression of flagellin and severely limits systemic and mucosal Salmonella infections in an NLRC4 inflammasome-dependent manner. These data establish that recognition of Salmonella's flagellin by the NLRC4 inflammasome during mucosal infection is the dominant innate protective pathway for host resistance against the enteric pathogen and that FlgM-mediated evasion of the NLRC4 inflammasome enhances virulence and intestinal tissue destruction.

Localised Collagen2a1 secretion supports lymphatic endothelial cell migration in the zebrafish embryo.

The lymphatic vasculature develops primarily from pre-existing veins. A pool of lymphatic endothelial cells (LECs) first sprouts from cardinal veins followed by migration and proliferation to colonise embryonic tissues. Although much is known about the molecular regulation of LEC fate and sprouting during early lymphangiogenesis, we know far less about the instructive and permissive signals that support LEC migration through the embryo. Using a forward genetic screen, we identified mbtps1 and sec23a, components of the COP-II protein secretory pathway, as essential for developmental lymphangiogenesis. In both mutants, LECs initially depart the cardinal vein but then fail in their ongoing migration. A key cargo that failed to be secreted in both mutants was a type II collagen (Col2a1). Col2a1 is normally secreted by notochord sheath cells, alongside which LECs migrate. col2a1a mutants displayed defects in the migratory behaviour of LECs and failed lymphangiogenesis. These studies thus identify Col2a1 as a key cargo secreted by notochord sheath cells and required for the migration of LECs. These findings combine with our current understanding to suggest that successive cell-to-cell and cell-matrix interactions regulate the migration of LECs through the embryonic environment during development.

Fins, fur, and wings: the study of Tmem161b across species, and what it tells us about its function in the heart.

Transmembrane protein 161b (Tmem161b) was recently identified in multiple high-through-put phenotypic screens, including in fly, zebrafish, and mouse. In zebrafish, Tmem161b was identified as an essential regulator of cardiac rhythm. In mouse, Tmem161b shows conserved function in regulating cardiac rhythm but has also been shown to impact cardiac morphology. Homozygous or heterozygous missense mutations have also recently been reported for TMEM161B in patients with structural brain malformations, although its significance in the human heart remains to be determined. Across the three model organisms studied to date (fly, fish, and mouse), Tmem161b loss of function is implicated in intracellular calcium ion handling, which may explain the diverse phenotypes observed. This review summarises the current knowledge of this conserved and functionally essential protein in the context of cardiac biology.

Collapsing glomerulopathy: unraveling varied pathogeneses.

PURPOSE OF REVIEW: Collapsing glomerulopathy presents clinically with nephrotic syndrome and rapid progressive loss of kidney function. Animal models and patient studies have uncovered numerous clinical and genetic conditions associated with collapsing glomerulopathy, as well as putative mechanisms, which will be reviewed here. RECENT FINDINGS: Collapsing glomerulopathy is classified pathologically as a variant of focal and segmental glomerulosclerosis (FSGS). As such, most research efforts have focused on the causative role of podocyte injury in driving the disease. However, studies have also shown that injury to the glomerular endothelium or interruption of the podocyte-glomerular endothelial cell signaling axis can also cause collapsing glomerulopathy. Furthermore, emerging technologies are now enabling exploration of diverse molecular pathways that can precipitate collapsing glomerulopathy using biopsies from patients with the disease. SUMMARY: Since its original description in the 1980s, collapsing glomerulopathy has been the subject of intense study, and these efforts have uncovered numerous insights into potential disease mechanisms. Newer technologies will enable profiling of the intra-patient and inter-patient variability in collapsing glomerulopathy mechanisms directly in patient biopsies, which will improve the diagnosis and classification of collapsing glomerulopathy.

Testing reciprocal associations between child anxiety and parenting across early interventions for inhibited preschoolers.

BACKGROUND: Given the robust evidence base for the efficacy of evidence-based treatments targeting youth anxiety, researchers have advanced beyond efficacy outcome analysis to identify mechanisms of change and treatment directionality. Grounded in developmental transactional models, interventions for young children at risk for anxiety by virtue of behaviorally inhibited temperament often target parenting and child factors implicated in the early emergence and maintenance of anxiety. In particular, overcontrolling parenting moderates risk for anxiety among highly inhibited children, just as child inhibition has been shown to elicit overcontrolling parenting. Although longitudinal research has elucidated the temporal unfolding of factors that interact to place inhibited children at risk for anxiety, reciprocal transactions between these child and parent factors in the context of early interventions remain unknown. METHOD: This study addresses these gaps by examining mechanisms of change and treatment directionality (i.e., parent-to-child vs. child-to-parent influences) within a randomized controlled trial comparing two interventions for inhibited preschoolers (N = 151): the multicomponent Turtle Program ('Turtle') and the parent-only Cool Little Kids program ('CLK'). Reciprocal relations between parent-reported child anxiety, observed parenting, and parent-reported accommodation of child anxiety were examined across four timepoints: pre-, mid-, and post-treatment, and one-year follow-up (NCT02308826). RESULTS: Hypotheses were tested via latent curve models with structured residuals (LCM-SR) and latent change score (LCS) models. LCM-SR results were consistent with the child-to-parent influences found in previous research on cognitive behavioral therapy (CBT) for older anxious youth, but only emerged in Turtle. LCS analyses revealed bidirectional effects of changes in parent accommodation and child anxiety during and after intervention, but only in Turtle. CONCLUSION: Our findings coincide with developmental transactional models, suggesting that the development of child anxiety may result from child-to-parent influences rather than the reverse, and highlight the importance of targeting parent and child factors simultaneously in early interventions for young, inhibited children.

Tocilizumab for treatment of chronic active antibody-mediated rejection in kidney transplant recipients.

BACKGROUND: The optimal treatment for chronic active antibody-mediated rejection (ca-AMR) remains unclear. Tocilizumab (TCZ), a monoclonal antibody against IL-6, has been proposed as a therapeutic option. We reported our experience treating ca-AMR with TCZ either as the first line option or as a rescue therapy. METHODS: We studied 11 adult kidney transplant recipients with biopsy-proven ca-AMR and preserved kidney function (eGFR 57 ± 18) who were treated with TCZ (8 mg/kg IV monthly). All biopsies were prompted by abnormal surveillance biomarker testing with DSA and/or dd-cfDNA. Clinical monitoring included dd-cfDNA and DSA testing every 3 months during the treatment with TCZ. RESULTS: In this cohort, ca-AMR was diagnosed at a median of 90 months (range 14-224) post-transplant, and 4 of 11 patients had DSA negative ca-AMR. Patients received a minimum of 3 months of TCZ, with 6 patients receiving at least 12 months of TCZ. Dd-cfDNA was elevated in all patients, with a median 2.24% at the start of TCZ treatment. After 6 months of TCZ treatment, 8/11 patients had dd- cfDNA <1%, and 3/11 had values <0.5%. Among those who completed at least 12 months of TCZ, dd-cfDNA decreased by 29% at 6 months (p = .05) and 47% by 12 months (p = .04). DSA also stabilized and, by 12 months, was reduced by 29% (p = .047). Graft function remained stable with no graft loss during treatment. There was a nonsignificant trend towards proteinuria reduction. During the course of treatment with tocilizumab, two patients experienced moderate to severe infections. CONCLUSIONS: In our early short-term experience, TCZ appears to reduce graft injury as measured by dd-cfDNA and modulate the immune response as evident by a modest reduction in immunodominant DSA MFI. Allograft function and proteinuria also stabilized.

Medullary kappa-opioid receptor neurons inhibit pain and itch through a descending circuit.

In perilous and stressful situations, the ability to suppress pain can be critical for survival. The rostral ventromedial medulla contains neurons that robustly inhibit nocioception at the level of the spinal cord through a top-down modulatory pathway. Although much is known about the role of the rostral ventromedial medulla in the inhibition of pain, the precise ability to directly manipulate pain-inhibitory neurons in the rostral ventromedial medulla has never been achieved. We now expose a cellular circuit that inhibits nocioception and itch in mice. Through a combination of molecular, tracing and behavioural approaches, we found that rostral ventromedial medulla neurons containing the kappa-opioid receptor inhibit itch and nocioception. With chemogenetic inhibition, we uncovered that these neurons are required for stress-induced analgesia. Using intersectional chemogenetic and pharmacological approaches, we determined that rostral ventromedial medulla kappa-opioid receptor neurons inhibit nocioception and itch through a descending circuit. Lastly, we identified a dynorphinergic pathway arising from the periaqueductal grey that modulates nociception within the rostral ventromedial medulla. These discoveries highlight a distinct population of rostral ventromedial medulla neurons capable of broadly and robustly inhibiting itch and nocioception.

Tonsillitis and Tonsilloliths: Diagnosis and Management.

Tonsillitis, or inflammation of the tonsils, makes up approximately 0.4% of outpatient visits in the United States. Tonsillitis is caused by a viral infection in 70% to 95% of cases. However, bacterial infections caused by group A beta-hemolytic streptococcus (Streptococcus pyogenes) account for tonsillitis in 5% to 15% of adults and 15% to 30% of patients five to 15 years of age. It is important to differentiate group A beta-hemolytic streptococcus from other bacterial or viral causes of pharyngitis and tonsillitis because of the risk of progression to more systemic complications such as abscess, acute glomerulonephritis, rheumatic fever, and scarlet fever after infection with group A beta-hemolytic streptococcus. A variety of diagnostic tools are available, including symptom-based validated scoring systems (e.g., Centor score), and oropharyngeal and serum laboratory testing. Treatment is focused on supportive care, and if group A beta-hemolytic streptococcus is identified, penicillin should be used as the first-line antibiotic. In cases of recurrent tonsillitis, watchful waiting is strongly recommended if there have been less than seven episodes in the past year, less than five episodes per year for the past two years, or less than three episodes per year for the past three years. Tonsilloliths, or tonsil stones, are managed expectantly, and small tonsilloliths are common clinical findings. Rarely, surgical intervention is required if they become too large to pass on their own.

mafba is a downstream transcriptional effector of Vegfc signaling essential for embryonic lymphangiogenesis in zebrafish.

The lymphatic vasculature plays roles in tissue fluid balance, immune cell trafficking, fatty acid absorption, cancer metastasis, and cardiovascular disease. Lymphatic vessels form by lymphangiogenesis, the sprouting of new lymphatics from pre-existing vessels, in both development and disease contexts. The apical signaling pathway in lymphangiogenesis is the VEGFC/VEGFR3 pathway, yet how signaling controls cellular transcriptional output remains unknown. We used a forward genetic screen in zebrafish to identify the transcription factor mafba as essential for lymphatic vessel development. We found that mafba is required for the migration of lymphatic precursors after their initial sprouting from the posterior cardinal vein. mafba expression is enriched in sprouts emerging from veins, and we show that mafba functions cell-autonomously during lymphatic vessel development. Mechanistically, Vegfc signaling increases mafba expression to control downstream transcription, and this regulatory relationship is dependent on the activity of SoxF transcription factors, which are essential for mafba expression in venous endothelium. Here we identify an indispensable Vegfc-SoxF-Mafba pathway in lymphatic development.