Modeling recent human evolution in mice by expression of a selected EDAR variant.

An adaptive variant of the human Ectodysplasin receptor, EDARV370A, is one of the strongest candidates of recent positive selection from genome-wide scans. We have modeled EDAR370A in mice and characterized its phenotype and evolutionary origins in humans. Our computational analysis suggests the allele arose in central China approximately 30,000 years ago. Although EDAR370A has been associated with increased scalp hair thickness and changed tooth morphology in humans, its direct biological significance and potential adaptive role remain unclear. We generated a knockin mouse model and find that, as in humans, hair thickness is increased in EDAR370A mice. We identify new biological targets affected by the mutation, including mammary and eccrine glands. Building on these results, we find that EDAR370A is associated with an increased number of active eccrine glands in the Han Chinese. This interdisciplinary approach yields unique insight into the generation of adaptive variation among modern humans.

Cervicovaginal bacteria are a major modulator of host inflammatory responses in the female genital tract.

Colonization by Lactobacillus in the female genital tract is thought to be critical for maintaining genital health. However, little is known about how genital microbiota influence host immune function and modulate disease susceptibility. We studied a cohort of asymptomatic young South African women and found that the majority of participants had genital communities with low Lactobacillus abundance and high ecological diversity. High-diversity communities strongly correlated with genital pro-inflammatory cytokine concentrations in both cross-sectional and longitudinal analyses. Transcriptional profiling suggested that genital antigen-presenting cells sense gram-negative bacterial products in situ via Toll-like receptor 4 signaling, contributing to genital inflammation through activation of the NF-κB signaling pathway and recruitment of lymphocytes by chemokine production. Our study proposes a mechanism by which cervicovaginal microbiota impact genital inflammation and thereby might affect a woman's reproductive health, including her risk of acquiring HIV.

Combining genomics and epidemiology to track mumps virus transmission in the United States.

Unusually large outbreaks of mumps across the United States in 2016 and 2017 raised questions about the extent of mumps circulation and the relationship between these and prior outbreaks. We paired epidemiological data from public health investigations with analysis of mumps virus whole genome sequences from 201 infected individuals, focusing on Massachusetts university communities. Our analysis suggests continuous, undetected circulation of mumps locally and nationally, including multiple independent introductions into Massachusetts and into individual communities. Despite the presence of these multiple mumps virus lineages, the genomic data show that one lineage has dominated in the US since at least 2006. Widespread transmission was surprising given high vaccination rates, but we found no genetic evidence that variants arising during this outbreak contributed to vaccine escape. Viral genomic data allowed us to reconstruct mumps transmission links not evident from epidemiological data or standard single-gene surveillance efforts and also revealed connections between apparently unrelated mumps outbreaks.

Utilising clinical parameters to improve the selection of nerve biopsy candidates.

BACKGROUND: Peripheral nerve biopsy is a valuable final diagnostic tool; however, histopathological results can be non-diagnostic. AIMS: We aim to identify quality improvement measures by evaluating the pre-biopsy assessment and diagnostic yield of specific histopathological diagnosis. METHODS: This was a retrospective study based on 10 years of experience with peripheral nerve biopsies at a single centre. Clinical data were obtained regarding pre-biopsy history, examination, serum and cerebrospinal fluid (CSF) investigations, neurophysiology and peripheral nerve imaging. Based upon a histopathological outcome, patients were grouped into vasculitis, granulomatous and infiltrative (diagnostic) group, or a comparison group of non-specific axonal neuropathy and normal (non-specific/normal) group. RESULTS: From a cohort of 64 patients, 21 (32.8%) were included in the diagnostic group and 30 (46.9%) in the non-specific/normal group. Clinical parameters associated with the diagnostic group were shorter history (mean 10.2 months vs 38.1), stepwise progression (81% vs 20%), neuropathic pain (85.7% vs 56.7%), vasculitic rash (23.8% vs 0%), mononeuritis multiplex (57.1% vs 10%), asymmetry (90.5% vs 60%), raised white cell count (47.6% vs 16.7%), myeloperoxidase antibody (19.1% vs 0%) and abnormal peripheral nerve imaging (33.3% vs 10%). CONCLUSION: Selection of patients undergoing nerve biopsy requires careful consideration of clinical parameters, including peripheral nerve imaging. Several quality improvement measures are proposed to improve yield of clinically actionable information from nerve biopsy.

Can guidance during play enhance children's learning and development in educational contexts? A systematic review and meta-analysis.

This systematic review and meta-analysis considered evidence of guided play compared to direct instruction or free play to support children's learning and development. Interventions from 39 studies were reviewed (published 1977-2020); 17 were included in meta-analysis (Ntotal  = 3893; Mchildage  = 1-8 years; Mgirls 49.8%; Methnicity White 41%, African American/Black 28%, Hispanic 19%). Guided play had a greater positive effect than direct instruction on early maths skills (g = 0.24), shape knowledge (g = 0.63), and task switching (g = 0.40); and than free play on spatial vocabulary (g = 0.93). Differences were not identified for other key outcomes. Narrative synthesis highlighted heterogeneity in the conceptualization and implementation of guided play across studies.

A rapid review of the impact of quarantine and restricted environments on children's play and the role of play in children's health.

Amidst the coronavirus disease 2019 (COVID-19) pandemic, there is uncertainty regarding potential lasting impacts on children's health and educational outcomes. Play, a fundamental part of childhood, may be integral to children's health during crises. We undertook a rapid review of the impact of quarantine, isolation and other restrictive environments on play and whether play mitigates adverse effects of such restrictions. Fifteen peer-reviewed studies were identified, spanning hospitals, juvenile and immigration detention and refugee camps. We found evidence of changes in children's access to play in crises and quarantine. These studies indicated how play might support children enduring isolation but lacked robust investigations of play as an intervention in mitigating impacts of restriction. Studies pertaining to children in isolation due to infectious disease outbreaks were notably absent. It is important that the potential effects of changes to such a crucial aspect of childhood are better understood to support children in this and future crises.

The effects of transcranial direct current stimulation on within- and cross-paradigm transfer following multi-session backward recall training.

Transcranial direct current stimulation (tDCS) has been shown to enhance the efficacy and generalisation of working memory (WM) training, but there has been little systematic investigation into how coupling task-specific WM training with stimulation impacts more specifically on transfer to untrained tasks. This randomised controlled trial investigated the boundary conditions to transfer by testing firstly whether the benefits of training on backward digit recall (BDR) extend to untrained backward recall tasks and n-back tasks with different materials, and secondly which, if any, form of transfer is enhanced by tDCS. Forty-eight participants were allocated to one of three conditions: BDR training with anodal (10 min, 1 mA) or sham tDCS, or visual search training with sham tDCS, applied over the left dorsolateral prefrontal cortex. Transfer was assessed on within- (backward recall with digits, letters, and spatial locations) and cross-paradigm (n-back with digits and letters) transfer tests following three sessions of training and stimulation. On-task training gains were found, with transfer to other backward span but not n-back tasks. There was little evidence that tDCS enhanced on-task training or transfer. These findings indicate that training enhances paradigm-specific processes within WM, but that tDCS does not enhance these gains.

Speaker gaze increases information coupling between infant and adult brains.

When infants and adults communicate, they exchange social signals of availability and communicative intention such as eye gaze. Previous research indicates that when communication is successful, close temporal dependencies arise between adult speakers' and listeners' neural activity. However, it is not known whether similar neural contingencies exist within adult-infant dyads. Here, we used dual-electroencephalography to assess whether direct gaze increases neural coupling between adults and infants during screen-based and live interactions. In experiment 1 (n = 17), infants viewed videos of an adult who was singing nursery rhymes with (i) direct gaze (looking forward), (ii) indirect gaze (head and eyes averted by 20°), or (iii) direct-oblique gaze (head averted but eyes orientated forward). In experiment 2 (n = 19), infants viewed the same adult in a live context, singing with direct or indirect gaze. Gaze-related changes in adult-infant neural network connectivity were measured using partial directed coherence. Across both experiments, the adult had a significant (Granger) causal influence on infants' neural activity, which was stronger during direct and direct-oblique gaze relative to indirect gaze. During live interactions, infants also influenced the adult more during direct than indirect gaze. Further, infants vocalized more frequently during live direct gaze, and individual infants who vocalized longer also elicited stronger synchronization from the adult. These results demonstrate that direct gaze strengthens bidirectional adult-infant neural connectivity during communication. Thus, ostensive social signals could act to bring brains into mutual temporal alignment, creating a joint-networked state that is structured to facilitate information transfer during early communication and learning.

Cyberbullying and Social Media: Information and Interventions for School Nurses Working With Victims, Students, and Families.

Social media has become an increasingly prevalent fixture in youths' lives, with over 90% of teenagers reporting daily usage. These online sites and applications have provided many positive opportunities for youths to connect and share ideas with others; however, social media has also become a major platform for cyberbullying. Victims often experience negative health outcomes directly related to cyberbullying. For this reason, it is critical that third parties, such as school nurses, are well versed in social media and the warning signs of those being victimized by cyberbullying. Therefore, this integrative review examines school nurses' knowledge of cyberbullying and social media and identifies the implications for school nursing practice regarding prevention and intervention processes.

Immune and molecular correlates in melanoma treated with immune checkpoint blockade.

Immunotherapy for metastatic melanoma has a decades-long history, and the relatively recent use of checkpoint inhibitors has revolutionized treatment. Durable and sometimes complete remission of metastatic melanoma is now achievable in some patients who receive checkpoint-blocking therapy. However, it is unclear why some patients fare better than others. This review highlights several molecular indicators of response to checkpoint inhibition in metastatic melanoma, focusing on tumor programmed death ligand 1 expression, major histocompatibility complex class I expression, mutational load in the tumor, and T-cell infiltration into the tumor. In addition, clinical correlates of response, notably vitiligo and other immune-related adverse events, can potentially shed light on the mechanisms by which checkpoint blockade may achieve such great success, particularly in melanoma. The authors propose that microphthalmia-associated transcription factor-a key regulator of melanocyte survival, melanin production, and melanoma transformation-produces a molecular landscape in melanocytes and melanoma cells that can make melanomas particularly susceptible to checkpoint blockade and also can result in immune attack on normal melanocytes. Cancer 2017;123:2143-53. © 2017 American Cancer Society.

Transcranial Random Noise Stimulation Does Not Enhance the Effects of Working Memory Training.

Transcranial random noise stimulation (tRNS), a noninvasive brain stimulation technique, enhances the generalization and sustainability of gains following mathematical training. Here it is combined for the first time with working memory training in a double-blind randomized controlled trial. Adults completed 10 sessions of Cogmed Working Memory Training with either active tRNS or sham stimulation applied bilaterally to dorsolateral pFC. Training was associated with gains on both the training tasks and on untrained tests of working memory that shared overlapping processes with the training tasks, but not with improvements on working memory tasks with distinct processing demands or tests of other cognitive abilities (e.g., IQ, maths). There was no evidence that tRNS increased the magnitude or transfer of these gains. Thus, combining tRNS with Cogmed Working Memory Training provides no additional therapeutic value.

Association between vaginal microbiota and vaginal inflammatory immune markers in postmenopausal women.

OBJECTIVE: In premenopausal individuals, vaginal microbiota diversity and lack of Lactobacillus dominance are associated with greater mucosal inflammation, which is linked to a higher risk of cervical dysplasia and infections. It is not known if the association between the vaginal microbiota and inflammation is present after menopause, when the vaginal microbiota is generally higher-diversity and fewer people have Lactobacillus dominance. METHODS: This is a post hoc analysis of a subset of postmenopausal individuals enrolled in a randomized trial for treatment of moderate-severe vulvovaginal discomfort that compared vaginal moisturizer, estradiol, or placebo. Vaginal fluid samples from 0, 4, and 12 weeks were characterized using 16S rRNA gene sequencing (microbiota) and MesoScale Discovery (vaginal fluid immune markers: IL-1b, IL-1a, IL-2, IL-6, IL-18, IL-10, IL-9, IL-13, IL-8, IP10, MIP1a, MIP1b, MIP3a). Global associations between cytokines and microbiota (assessed by relative abundance of individual taxa and Shannon index for alpha, or community, diversity) were explored, adjusting for treatment arm, using linear mixed models, principal component analysis, and Generalized Linear Mixed Model + Microbiome Regression-based Kernel Association Test (GLMM-MiRKAT). RESULTS: A total of 119 individuals with mean age of 61 years were included. At baseline, 29.5% of participants had a Lactobacillus-dominant vaginal microbiota. Across all timepoints, alpha diversity (Shannon index, P = 0.003) was highly associated with immune markers. Individual markers that were associated with Lactobacillus dominance were similar to those observed in premenopausal people: IL-10, IL-1b, IL-6, IL-8 (false discovery rate [FDR] < 0.01), IL-13 (FDR = 0.02), and IL-2 (FDR = 0.09). Over 12 weeks, change in alpha diversity was associated with change in cytokine concentration (Shannon, P = 0.018), with decreased proinflammatory cytokine concentrations observed with decreasing alpha diversity. CONCLUSIONS: In this cohort of postmenopausal individuals, Lactobacillus dominance and lower alpha diversity were associated with lower concentrations of inflammatory immune markers, as has been reported in premenopausal people. This suggests that after menopause lactobacilli continue to have beneficial effects on vaginal immune homeostasis, despite lower prevalence.

Genome-wide detection and characterization of positive selection in human populations.

With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms from the International HapMap Project Phase 2 (HapMap2). We used 'long-range haplotype' methods, which were developed to identify alleles segregating in a population that have undergone recent selection, and we also developed new methods that are based on cross-population comparisons to discover alleles that have swept to near-fixation within a population. The analysis reveals more than 300 strong candidate regions. Focusing on the strongest 22 regions, we develop a heuristic for scrutinizing these regions to identify candidate targets of selection. In a complementary analysis, we identify 26 non-synonymous, coding, single nucleotide polymorphisms showing regional evidence of positive selection. Examination of these candidates highlights three cases in which two genes in a common biological process have apparently undergone positive selection in the same population:LARGE and DMD, both related to infection by the Lassa virus, in West Africa;SLC24A5 and SLC45A2, both involved in skin pigmentation, in Europe; and EDAR and EDA2R, both involved in development of hair follicles, in Asia.

Immunohistochemical distinction of haematogones from B lymphoblastic leukaemia/lymphoma or B-cell acute lymphoblastic leukaemia (B-ALL) on bone marrow trephine biopsies: a study on 62 patients.

Haematogones are normal, maturing B-cell precursors. They can be confused with neoplastic immature lymphoid cells of B lymphoblastic leukaemia/lymphoma or B-cell acute lymphoblastic leukaemia (B-ALL). Though multi-colour flow-cytometry strategies for distinguishing haematogones from cells of B-ALL are well-described, similar strategies have not been determined for bone marrow trephine biopsies (BMTB). We revisited the morphological and immunohistochemical features (CD20, CD34, TdT and PAX5 expression) in 69 BMTB from 62 patients - 27 with excess haematogones; seven with residual B-ALL after therapy; 18 with no reported excess of haematogones or residual acute leukaemia on BMTB; and 17 diagnostic samples of B-ALL. The distinctive immunophenotypic pattern of BMTB with excess haematogones was of CD34, TdT, CD20 and PAX5 accounting for increasing proportions of cells in the order mentioned, whereas among B-ALL, the immunohistochemical pattern was of CD20, PAX5 and TdT accounting for an equal proportion of cells. Furthermore, among haematogones, the intensity of CD20 expression was extremely heterogeneous as compared to the neoplastic cells in CD20-positive B-ALL. The TdT-positive haematogones were generally small and uniform, while a certain degree of heterogeneity was noticed among neoplastic B-ALL cells. This study provides a practical strategy to distinguish haematogones from B-ALL cells in BMTB.

Antigen Presenting Cells Link the Female Genital Tract Microbiome to Mucosal Inflammation, With Hormonal Contraception as an Additional Modulator of Inflammatory Signatures.

The microbiome of the female genital tract (FGT) is closely linked to reproductive health outcomes. Diverse, anaerobe-dominated communities with low Lactobacillus abundance are associated with a number of adverse reproductive outcomes, such as preterm birth, cervical dysplasia, and sexually transmitted infections (STIs), including HIV. Vaginal dysbiosis is associated with local mucosal inflammation, which likely serves as a biological mediator of poor reproductive outcomes. Yet the precise mechanisms of this FGT inflammation remain unclear. Studies in humans have been complicated by confounding demographic, behavioral, and clinical variables. Specifically, hormonal contraception is associated both with changes in the vaginal microbiome and with mucosal inflammation. In this study, we examined the transcriptional landscape of cervical cell populations in a cohort of South African women with differing vaginal microbial community types. We also investigate effects of reproductive hormones on the transcriptional profiles of cervical cells, focusing on the contraceptive depot medroxyprogesterone acetate (DMPA), the most common form of contraception in sub-Saharan Africa. We found that antigen presenting cells (APCs) are key mediators of microbiome associated FGT inflammation. We also found that DMPA is associated with significant transcriptional changes across multiple cell lineages, with some shared and some distinct pathways compared to the inflammatory signature seen with dysbiosis. These results highlight the importance of an integrated, systems-level approach to understanding host-microbe interactions, with an appreciation for important variables, such as reproductive hormones, in the complex system of the FGT mucosa.

Development of a qualitative real-time RT-PCR assay for the detection of SARS-CoV-2: a guide and case study in setting up an emergency-use, laboratory-developed molecular microbiological assay.

Developing and deploying new diagnostic tests are difficult, but the need to do so in response to a rapidly emerging pandemic such as COVID-19 is crucially important. During a pandemic, laboratories play a key role in helping healthcare providers and public health authorities detect active infection, a task most commonly achieved using nucleic acid-based assays. While the landscape of diagnostics is rapidly evolving, PCR remains the gold-standard of nucleic acid-based diagnostic assays, in part due to its reliability, flexibility and wide deployment. To address a critical local shortage of testing capacity persisting during the COVID-19 outbreak, our hospital set up a molecular-based laboratory developed test (LDT) to accurately and safely diagnose SARS-CoV-2. We describe here the process of developing an emergency-use LDT, in the hope that our experience will be useful to other laboratories in future outbreaks and will help to lower barriers to establishing fast and accurate diagnostic testing in crisis conditions.

Development of a qualitative real-time RT-PCR assay for the detection of SARS-CoV-2: A guide and case study in setting up an emergency-use, laboratory-developed molecular assay.

Developing and deploying new diagnostic tests is difficult, but the need to do so in response to a rapidly emerging pandemic such as COVID-19 is crucially important for an effective response. In the early stages of a pandemic, laboratories play a key role in helping health care providers and public health authorities detect active infection, a task most commonly achieved using nucleic acid-based assays. While the landscape of diagnostics is rapidly evolving, polymerase chain reaction (PCR) remains the gold-standard of nucleic acid-based diagnostic assays, in part due to its reliability, flexibility, and wide deployment. To address a critical local shortage of testing capacity persisting during the COVID-19 outbreak, our hospital set up a molecular based laboratory developed test (LDT) to accurately and safely diagnose SARS-CoV-2. We describe here the process of developing an emergency-use LDT, in the hope that our experience will be useful to other laboratories in future outbreaks and will help to lower barriers to fast and accurate diagnostic testing in crisis conditions.

The Wound Microenvironment Reprograms Schwann Cells to Invasive Mesenchymal-like Cells to Drive Peripheral Nerve Regeneration.

Schwann cell dedifferentiation from a myelinating to a progenitor-like cell underlies the remarkable ability of peripheral nerves to regenerate following injury. However, the molecular identity of the differentiated and dedifferentiated states in vivo has been elusive. Here, we profiled Schwann cells acutely purified from intact nerves and from the wound and distal regions of severed nerves. Our analysis reveals novel facets of the dedifferentiation response, including acquisition of mesenchymal traits and a Myc module. Furthermore, wound and distal dedifferentiated Schwann cells constitute different populations, with wound cells displaying increased mesenchymal character induced by localized TGFß signaling. TGFß promotes invasion and crosstalks with Eph signaling via N-cadherin to drive collective migration of the Schwann cells across the wound. Consistently, Tgfbr2 deletion in Schwann cells resulted in misdirected and delayed reinnervation. Thus, the wound microenvironment is a key determinant of Schwann cell identity, and it promotes nerve repair through integration of multiple concerted signals. VIDEO ABSTRACT.