Variation in diagnosis of urinary incontinence in women by provider and patient demographic factors.

INTRODUCTION: Urinary incontinence (UI) among women is under-recognized in primary care setting. We hypothesized that UI is, therefore, more commonly diagnosed by specialists. Our aim was to determine the rate of UI diagnosis by provider and patient demographics, and whether these factors affect the likelihood of UI diagnosis. METHODS: Retrospective study using electronic medical records from 2010 to 2019. Ambulatory patient encounters by adult females were identified. Encounters with new diagnosis of UI (stress, urgency, mixed, or unspecified) were identified using ICD 9 and 10 codes. The following data were extracted: diagnosing provider specialty and sex, patient age, BMI, race, estimated household income, insurance coverage and type, and primary care provider (PCP). Rate of UI diagnosis was calculated using proportions. Univariable comparison and multivariable logistic regression were performed. RESULTS: 576,110 patient encounters were captured. 14,378 patient encounters had UI diagnosis (2.5%). UI population had the following characteristics: Mean age of 60.1 ± 15.5 years, 65.6% identified as white, 75.7% had a PCP, and 87.9% had insurance. UI diagnosis rate was < 1% for PCPs. Multivariable logistic regression showed that urogynecologists and female providers were more likely to diagnose UI; patient demographics associated with UI diagnosis included older age, elevated BMI, white race, commercial insurance, and having a PCP. Estimated household income did not have a significant effect. CONCLUSION: Diagnosis of UI is seldom made by PCPs. Race, insurance, and having a PCP may affect the likelihood of receiving UI diagnosis. Continued efforts to promote equity in recognizing UI may be warranted.

Training clinicians in culturally relevant care: a curriculum to improve knowledge and comfort with the transgender and gender diverse population.

PURPOSE: To design a replicable simulation curriculum collaboratively with the transgender and gender diverse community to improve clinician knowledge and comfort with providing reproductive care to this population. METHODS: This is a prospective, single arm pre-post analysis of obstetrics and gynecology residents at a single academic institution after completion of a novel simulation curriculum. The primary outcome was the change in resident comfort and knowledge in providing transgender and gender diverse patient care. A thematic analysis of learner and standardized patient free text responses was analyzed for insights on perceived learner experiences. RESULTS: This curriculum was created with iterative feedback from the transgender community and involved only transgender and gender diverse-identified standardized patients. Thirty residents participated, with 22 responding to both the pre-and post-curriculum surveys, and 11 responding to a 6-month post-curriculum survey. There were significant improvements in learner comfort and knowledge after participation that were found to persist at 6 months. Qualitative analysis demonstrated that this was a positive and powerful learning experience for both residents and standardized patients. CONCLUSIONS: This simulation curriculum may be an effective and impactful tool to increase trainee comfort and knowledge of transgender and gender diverse patient care, which is important given the lack of physician training in the care for these individuals. By building the foundation with resident learners, the ultimate goal is to enhance the pool of clinicians confident and capable of caring for transgender and gender diverse patients, to increase access to care, and to improve health outcomes in this vulnerable population.

Nrf2 regulates CD4+ T cell-induced acute graft-versus-host disease in mice.

Nuclear factor erythroid-derived 2-like 2 (Nrf2) is a ubiquitously expressed transcription factor that is well known for its role in regulating the cellular redox pathway. Although there is mounting evidence suggesting a critical role for Nrf2 in hematopoietic stem cells and innate leukocytes, little is known about its involvement in T-cell biology. In this study, we identified a novel role for Nrf2 in regulating alloreactive T-cell function during allogeneic hematopoietic cell transplantation (allo-HCT). We observed increased expression and nuclear translocation of Nrf2 upon T-cell activation in vitro, especially in CD4+ donor T cells after allo-HCT. Allo-HCT recipients of Nrf2 -/- donor T cells had significantly less acute graft-versus-host disease (GVHD)-induced mortality, morbidity, and pathology. This reduction in GVHD was associated with the persistence of Helios+ donor regulatory T cells in the allograft, as well as defective upregulation of the gut-homing receptor LPAM-1 on alloreactive CD8+ T cells. Additionally, Nrf2 -/- donor CD8+ T cells demonstrated intact cytotoxicity against allogeneic target cells. Tumor-bearing allo-HCT recipients of Nrf2 -/- donor T cells had overall improved survival as a result of preserved graft-versus-tumor activity and reduced GVHD activity. Our findings characterized a previously unrecognized role for Nrf2 in T-cell function, as well as revealed a novel therapeutic target to improve the outcomes of allo-HCT.

Insulin-like growth factor-1 and soluble FMS-like tyrosine kinase-1 prospectively predict cancelled IVF cycles.

PURPOSE: To identify biomarkers that prospectively predict IVF cycle cancellation. METHODS: In this prospective study, sera were obtained prior to any intervention, from women about to undergo an IVF cycle. The sera were assayed by ELISA for levels of insulin-like growth factor (IGF)-1, IGF-2, IGF binding protein (BP)-1, and soluble fms-like tyrosine kinase (sFLT-1). The cancellation or progression of the IVF cycle was subsequently obtained by chart review. Associations between serum components and outcome were analyzed by the Mann-Whitney test. Receiver operator curves were constructed to evaluate the strength of the correlations between biomarkers and cycle cancellation, as assessed from the area under the curve (AUC). RESULTS: A total of 205 women were included. Twenty-seven (13.2%) cycle cancellations due to poor response were recorded. Women with a cancelled cycle had reduced anti-Mullerian hormone (AMH) values (p < 0.001) and antral follicle count (p = 0.003). There were no significant differences between the two groups with regard to age and BMI. Median concentrations of IGF-1 and sFLT-1 were elevated in sera from women whose IVF cycles were cancelled as compared to those with ongoing cycles (p = 0.015 and p < 0.001, respectively); AUC for IGF-1 and sFLT-1 were 0.67 and 0.75, respectively. Concentrations of sFLT-1 remained significantly higher in patients with cancelled cycles even after controlling for AMH levels. There were no differences in IGF-2 and IGFBP-1 levels between the two groups. CONCLUSIONS: Measurement of circulating IGF-1 and sFLT-1 levels prior to initiation of an IVF cycle has the potential to identify women whose cycles have an increased likelihood to be subsequently cancelled.

IL-1ß predicts IVF outcome: a prospective study.

PURPOSE: Retrospective cohort studies have shown a relationship between maternal serum interleukin-1ß (IL-1ß) and interleukin-1 receptor antagonist (IL-1Ra) levels and in vitro fertilization (IVF) cycle outcome. The objective of this investigation was to explore the correlation between serum IL-1ß and/or IL-1Ra levels obtained prospectively and IVF outcomes. METHODS: Sera from 205 women were collected just prior to initiation of their IVF cycle, at the time of human chorionic gonadotropin administration, day 24 of IVF cycle, day 28, and day 35. Sera were analyzed for IL-1ß and IL-1Ra using commercially available ELISA kits. Cycle outcomes were followed prospectively. Data were analyzed using Friedman analysis of variance by ranks and chi-square analysis. RESULTS: Among women with a viable pregnancy, IL-1ß serum levels increased over time for those that proceeded to deliver or had an ongoing pregnancy. There was no increase in serum levels for those with subsequent pregnancy loss. Of the women that had an embryo transfer, detectable IL-1ß levels at the start of the cycle were associated with successful IVF outcome (p = 0.027). Of women with a positive pregnancy test, undetectable IL-1ß at the start of the cycle were associated with subsequent pregnancy loss (p = 0.046). For all IL1-Ra serum analysis, there were no significant results. CONCLUSIONS: The increasing levels of IL-1ß over time are consistent with the known role of the IL-1 cytokine family in implantation and pregnancy. Additionally, we confirm in a prospective investigation the positive relationship between detectable serum IL-1ß at the start of IVF cycle and outcome.

Quality of web-based family-building information for LGBTQ individuals.

OBJECTIVE: The number of patients who seek health information on the internet is increasing. Rates are particularly high among lesbian, gay, bisexual, transgender and queer (LGBTQ) individuals, due to health care barriers. The aim of this study was to evaluate the quality and inclusivity of web-based information pertaining to LGBTQ family building. METHODS: The first 100 US-based websites pertaining to LGBTQ family building were identified through a terminology-based internet search. After eliminating 45 websites, 55 websites were found to be eligible. The 2016 Website Information Reliability Evaluation Instrument (of the Office of Disease Prevention and Health Promotion, US Department of Health and Human Services) was used to analyse the quality of information on each website. Websites were analysed for inclusivity of important topics surrounding LGBTQ family building. RESULTS: A total of 46 websites (83.6%) belonged or were related to reproductive services and served as advertisements for their respective owners; nine websites (16.4%) belonged to third parties. No website met more than four of the six major reliability criteria, and 42 websites (76.4%) met only one or two of the six major reliability criteria. When inclusivity was considered, 29 websites (52.7%) mentioned options for transgender individuals and nine websites (16.4%) mentioned adoption. CONCLUSIONS: There is a lack of reliable web-based information for LGBTQ family building and a need for improvement in quality and scope. Improvements could lead to a shift in reproductive health care towards better inclusion of and catering to LGBTQ individuals.

Image-guided intrathymic injection of multipotent stem cells supports lifelong T-cell immunity and facilitates targeted immunotherapy.

T-cell deficiency related to disease, medical treatment, or aging represents a major clinical challenge and is associated with significant morbidity and mortality in cancer and bone marrow transplantation recipients. This study describes several innovative and clinically relevant strategies to manipulate thymic function based on an interventional radiology technique for intrathymic injection of cells or drugs. We show that intrathymic injection of multipotent hematopoietic stem/progenitor cells into irradiated syngeneic or allogeneic young or aged recipients resulted in efficient and long-lasting generation of functional donor T cells. Persistence of intrathymic donor cells was associated with intrathymic presence of cells resembling long-term hematopoietic stem cells, suggesting a self-renewal capacity of the intrathymically injected cells. Furthermore, our approach enabled the induction of long-term antigen-specific T-cell-mediated antitumor immunity following intrathymic injection of progenitor cells harboring a transgenic T-cell receptor gene. The intrathymic injection of interleukin-7 prior to irradiation conferred radioprotection. In addition, thymopoiesis of aged mice improved with a single intrathymic administration of low-dose keratinocyte growth factor, an effect that was sustained even in the setting of radiation-induced injury. Taken together, we established a preclinical framework for the development of novel clinical protocols to establish lifelong antigen-specific T-cell immunity.

Extreme enhanced myometrial vascularity following cesarean scar pregnancy: a new diagnostic entity.

OBJECTIVE: To define, illustrate and to follow-up the diagnosis, pathophysiology and treatment of a subset of the known enhanced myometrial vascularity (EMV): its extreme form, associated with cesarean scar pregnancies (CSP) and with some cases pf placenta accreta spectrum being at increased risk of significant bleeding complications. We also aim to provide guidance to the management of such cases. MATERIAL AND METHODS: This is an IRB-approved retrospective observational study of thirteen patients with an extreme form of EMV complicating CSPs. Patient's age, parity, number of cesarean deliveries, initial and time to negative serum hCG levels, primary and secondary diagnoses, blood flow peak systolic velocities, primary and secondary treatments, uterine artery embolization and outcomes were recorded. RESULTS: Gestational ages ranged 6-11 weeks at initial presentation. Initial serum hCG was 20.0-102.48 mIU/L (mean 44.4 mIU/L). Diameter of EMV reached 20-75 mm (mean 46.8 mm). The mean peak systolic velocity (PSV) was 84.2 cm/s (range 46.7-118.0). Primary treatments were: systemic methotrexate (MTX) alone; D&C alone; MTX and D&C; local and systemic intra-gestational MTX injection; double cervical ripening balloon with systemic MTX; misoprostol and D&C; emergent UAE. UAE and hysterectomy were the two main secondary treatments in 10 women except 1 having a D&C after UAE, and in 1 the lesion regressed without secondary treatment. Mean time to nonpregnant hCG levels was 21-122 days (mean 67.2). Mean follow-up was 110.2 days (range 26-160). Ten women were treated with UAE, 6 had one, 3 had two embolizations. Two women had hysterectomies, one of these for persistent bleeding. Based upon the common denominators of the clinical and the US pictures, our definition of extreme EMV is sustained form of EMV associated with treated or untreated CSP, with peak systolic velocities of blood flow over 50 cm/s, slow return or plateauing serum hCG, with or without clinically significant vaginal bleeding, unresponsive to initial or secondary treatment requiring uterine artery embolization or hysterectomy. CONCLUSION: The EMV developing in the background of retained placental tissue associated with CSP differs following the normal regression of the physiologically re-modelled, dilated vascular bed from the faulty "disrepair" of the vessel wall in in treated or untreated CSPs. The "threatening" appearance of the above EMVs warranted the term "extreme", creating their separate new sub-category." Extreme forms of CSP-related EMV pose significant diagnostic and management challenges. Prompt recognition and intervention, the proactive use of UAE, can maximize the outcome of women affected by this "extreme" form of EMV enabling to preserve reproductive potential. Obstetricians, gynecologists and interventional radiologists should be aware of this form of severe vascular complication.

The Effect of Symptomatic Stress Urinary Incontinence on Catheterization Rates After Intradetrusor OnabotulinumtoxinA Injections.

OBJECTIVES: To determine whether catheterization rates after intradetrusor onabotulinumtoxinA injection for nonneurogenic overactive bladder and urgency incontinence differ between women with urgency urinary incontinence only and women with urgency-predominant mixed urinary incontinence. METHODS: This was a retrospective cohort study of patients that underwent intradetrusor onabotulinumtoxinA injection of 100 U for nonneurogenic urgency urinary incontinence. The primary outcome was the difference in catheterization rates between women with urgency urinary incontinence alone compared with women with urgency-predominant mixed urinary incontinence. Descriptive statistics and multivariate logistic regression analysis were performed. RESULTS: Of the 177 women included in the final analysis, 105 had urgency urinary incontinence and 72 had urgency-predominant mixed urinary incontinence. The overall catheterization rate after onabotulinumtoxinA injection was 11.3%, with significantly fewer women with mixed urinary incontinence requiring catheterization when compared with women with urgency urinary incontinence alone (4.2% vs 16.2%; P = 0.03), despite an older population (P = 0.02). Patient-reported improvement (P = 0.37) and decision to continue onabotulinumtoxinA treatments (P = 0.89) were similar between groups. Multivariate logistic regression analysis revealed that women with mixed urinary incontinence had significantly lower odds of requiring catheterization after onabotulinumtoxinA injections than women with urgency urinary incontinence alone (odds ratio, 0.16; 95% confidence interval, 0.04-0.67; P = 0.01). CONCLUSIONS: Findings suggest that the presence of symptomatic stress urinary incontinence is associated with lower rates of catheterization after intradetrusor onabotulinumtoxinA, but does not compromise efficacy of treatment for urgency-predominant mixed urinary incontinence.

The PreOp Program: Intensive Preclinical Surgical Exposure is Associated With Increased Medical Student Surgical Interest and Competency.

OBJECTIVE: As medical students' interest in surgical fields wanes, we investigated the impact of a preclinical surgical exposure program on students' attitudes toward pursuing surgical careers. DESIGN: This is a prospective longitudinal study of PreOp, a preclinical rotation-based surgical exposure program for first-year medical students, from 2013 to 2017. Surveys assessed PreOp rotation quality, students' surgical interest, and students' self-reported preparedness for the surgical clerkship. Surgery clerkship grades were obtained as a measure of surgical competency and compared to class-wide peers. Match data was collected and compared to class-wide peers as well as historical norms. SETTING: NewYork-Presbyterian Hospital/Weill Cornell Medicine, New York, NY; tertiary care center. PARTICIPANTS: Fifty-four PreOp students from 2013 to 2017. RESULTS: Fifty-four PreOp participants were recruited. After completing the PreOp program, 66.7% of PreOp students reported being very likely to apply into a surgical field compared to 29.4% when they started medical school. Ultimately, 71.4% of PreOp students versus 21.7% of non-PreOp class-wide peers matched into surgical fields (p < 0.001). From the preceding 5 match years before PreOp implementation, 21.4% of all students matched into surgical fields compared to 25.6% of all students after PreOp was started (p = 0.26). In terms of preparedness, 75% of PreOp students reported feeling more prepared for the third-year surgery clerkship than their non-PreOp peers after the second year of medical school. PreOp students were significantly more likely than non-PreOp class-wide peers to receive honors in the surgery clerkship when controlling for cumulative clerkship GPA (p = 0.012, adjusted odds ratio = 5.5 [95% confidence interval 1.5-22.1]). CONCLUSIONS: Hands-on preclinical surgical exposure was associated with student-reported increased surgical interest that was maintained longitudinally and reflected in significantly increased surgical matches relative to non-PreOp class-wide peers. This study uniquely demonstrates that participation in PreOp was also associated with increased self-reported surgical preparedness and significantly higher surgery clerkship grades relative to overall academic performance.

Suppression of luteinizing hormone enhances HSC recovery after hematopoietic injury.

There is a substantial unmet clinical need for new strategies to protect the hematopoietic stem cell (HSC) pool and regenerate hematopoiesis after radiation injury from either cancer therapy or accidental exposure. Increasing evidence suggests that sex hormones, beyond their role in promoting sexual dimorphism, regulate HSC self-renewal, differentiation, and proliferation. We and others have previously reported that sex-steroid ablation promotes bone marrow (BM) lymphopoiesis and HSC recovery in aged and immunodepleted mice. Here we found that a luteinizing hormone (LH)-releasing hormone antagonist (LHRH-Ant), currently in wide clinical use for sex-steroid inhibition, promoted hematopoietic recovery and mouse survival when administered 24 h after an otherwise-lethal dose of total-body irradiation (L-TBI). Unexpectedly, this protective effect was independent of sex steroids and instead relied on suppression of LH levels. Human and mouse long-term self-renewing HSCs (LT-HSCs) expressed high levels of the LH/choriogonadotropin receptor (LHCGR) and expanded ex vivo when stimulated with LH. In contrast, the suppression of LH after L-TBI inhibited entry of HSCs into the cell cycle, thus promoting HSC quiescence and protecting the cells from exhaustion. These findings reveal a role of LH in regulating HSC function and offer a new therapeutic approach for hematopoietic regeneration after hematopoietic injury.

Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration.

The thymus is not only extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood, and this capacity diminishes considerably with age. We show that thymic endothelial cells (ECs) comprise a critical pathway of regeneration via their production of bone morphogenetic protein 4 (BMP4) ECs increased their production of BMP4 after thymic damage, and abrogating BMP4 signaling or production by either pharmacologic or genetic inhibition impaired thymic repair. EC-derived BMP4 acted on thymic epithelial cells (TECs) to increase their expression of Foxn1, a key transcription factor involved in TEC development, maintenance, and regeneration, and its downstream targets such as Dll4, a key mediator of thymocyte development and regeneration. These studies demonstrate the importance of the BMP4 pathway in endogenous tissue regeneration and offer a potential clinical approach to enhance T cell immunity.

Corrigendum: Suppression of luteinizing hormone enhances HSC recovery after hematopoietic injury.

This corrects the article DOI: 10.1038/nm.4470.

Stabilization of Tumor-Associated Craniovertebral Junction Instability: Indications, Operative Variables, and Outcomes.

BACKGROUND: Whether primary or metastatic, tumors of the craniovertebral junction (CVJ) are rare and challenging. OBJECTIVE: To examine the surgical indications, operative variables, and outcomes in patients with tumors of the CVJ undergoing occipitocervical (OC) stabilization. METHODS: A single-institution, retrospective case series was performed from a prospectively maintained spine database. Patients with primary or metastatic tumors of the CVJ who underwent OC stabilization were identified. Out of 46 patients who underwent OC fusion, 39 were for tumor. Paired t -tests and Wilcoxon rank-sum tests were performed to assess for postoperative changes. RESULTS: Ten patients (26%) harbored primary tumors, and the remaining 29 (74%) had metastatic disease. Of the metastatic patients, 14 had a neurological deficit, 10 had severe neck pain, and 5 were deemed mechanically unstable. Postoperative visual analog pain scores were significantly reduced at all 3 follow-up times ( P < .001, 95% confidence interval [CI; 3.2, 6.0]; P = .001, 95% CI [2.6, 7.7]; P = .020, 95% CI [0.6, 5.5]). The percentage of patients who were ambulatory and neurologically improved or intact remained stable postoperatively with no significant declines. There were 2 perioperative mortalities (5%), and 13 patients (33%) experienced a major complication. CONCLUSIONS: In patients with primary or metastatic tumor of the CVJ, OC stabilization using a cervical screw-rod system affixed to a midline-keel buttress plate, with or without posterior decompression, is a reliable method for CVJ stabilization in the oncologic setting. Improvement in pain and preservation of neurological function was seen.

Donor CD19 CAR T cells exert potent graft-versus-lymphoma activity with diminished graft-versus-host activity.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for hematological malignancies. However, graft-versus-host disease (GVHD) and relapse after allo-HSCT remain major impediments to the success of allo-HSCT. Chimeric antigen receptors (CARs) direct tumor cell recognition of adoptively transferred T cells. CD19 is an attractive CAR target, which is expressed in most B cell malignancies, as well as in healthy B cells. Clinical trials using autologous CD19-targeted T cells have shown remarkable promise in various B cell malignancies. However, the use of allogeneic CAR T cells poses a concern in that it may increase risk of the occurrence of GVHD, although this has not been reported in selected patients infused with donor-derived CD19 CAR T cells after allo-HSCT. To understand the mechanism whereby allogeneic CD19 CAR T cells may mediate anti-lymphoma activity without causing a significant increase in the incidence of GVHD, we studied donor-derived CD19 CAR T cells in allo-HSCT and lymphoma models in mice. We demonstrate that alloreactive T cells expressing CD28-costimulated CD19 CARs experience enhanced stimulation, resulting in the progressive loss of both their effector function and proliferative potential, clonal deletion, and significantly decreased occurrence of GVHD. Concurrently, the other CAR T cells that were present in bulk donor T cell populations retained their anti-lymphoma activity in accordance with the requirement that both the T cell receptor (TCR) and CAR be engaged to accelerate T cell exhaustion. In contrast, first-generation and 4-1BB-costimulated CAR T cells increased the occurrence of GVHD. These findings could explain the reduced risk of GVHD occurring with cumulative TCR and CAR signaling.

Characterization of a c-Rel Inhibitor That Mediates Anticancer Properties in Hematologic Malignancies by Blocking NF-κB-Controlled Oxidative Stress Responses.

NF-κB plays a variety of roles in oncogenesis and immunity that may be beneficial for therapeutic targeting, but strategies to selectively inhibit NF-κB to exert antitumor activity have been elusive. Here, we describe IT-901, a bioactive naphthalenethiobarbiturate derivative that potently inhibits the NF-κB subunit c-Rel. IT-901 suppressed graft-versus-host disease while preserving graft-versus-lymphoma activity during allogeneic transplantation. Further preclinical assessment of IT-901 for the treatment of human B-cell lymphoma revealed antitumor properties in vitro and in vivo without restriction to NF-κB-dependent lymphoma. This nondiscriminatory, antilymphoma effect was attributed to modulation of the redox homeostasis in lymphoma cells resulting in oxidative stress. Moreover, NF-κB inhibition by IT-901 resulted in reduced stimulation of the oxidative stress response gene heme oxygenase-1, and we demonstrated that NF-κB inhibition exacerbated oxidative stress induction to inhibit growth of lymphoma cells. Notably, IT-901 did not elicit increased levels of reactive oxygen species in normal leukocytes, illustrating its cancer selective properties. Taken together, our results provide mechanistic insight and preclinical proof of concept for IT-901 as a novel therapeutic agent to treat human lymphoid tumors and ameliorate graft-versus-host disease.

Optical stimulation of zebrafish hair cells expressing channelrhodopsin-2.

Vertebrate hair cells are responsible for the high fidelity encoding of mechanical stimuli into trains of action potentials (spikes) in afferent neurons. Here, we generated a transgenic zebrafish line expressing Channelrhodopsin-2 (ChR2) under the control of the hair-cell specific myo6b promoter, in order to examine the role of the mechanoelectrical transduction (MET) channel in sensory encoding in afferent neurons. We performed in vivo recordings from afferent neurons of the zebrafish lateral line while activating hair cells with either mechanical stimuli from a waterjet or optical stimuli from flashes of ∼470-nm light. Comparison of the patterns of encoded spikes during 100-ms stimuli revealed no difference in mean first spike latency between the two modes of activation. However, there was a significant increase in the variability of first spike latency during optical stimulation as well as an increase in the mean number of spikes per stimulus. Next, we compared encoding of spikes during hair-cell stimulation at 10, 20, and 40-Hz. Consistent with the increased variability of first spike latency, we saw a significant decrease in the vector strength of phase-locked spiking during optical stimulation. These in vivo results support a physiological role for the MET channel in the high fidelity of first spike latency seen during encoding of mechanical sensory stimuli. Finally, we examined whether remote activation of hair cells via ChR2 activation was sufficient to elicit escape responses in free-swimming larvae. In transgenic larvae, 100-ms flashes of ∼470-nm light resulted in escape responses that occurred concomitantly with field recordings indicating Mauthner cell activity. Altogether, the myo6b:ChR2 transgenic line provides a platform to investigate hair-cell function and sensory encoding, hair-cell sensory input to the Mauthner cell, and the ability to remotely evoke behavior in free-swimming zebrafish.

Sex steroid blockade enhances thymopoiesis by modulating Notch signaling.

Paradoxical to its importance for generating a diverse T cell repertoire, thymic function progressively declines throughout life. This process has been at least partially attributed to the effects of sex steroids, and their removal promotes enhanced thymopoiesis and recovery from immune injury. We show that one mechanism by which sex steroids influence thymopoiesis is through direct inhibition in cortical thymic epithelial cells (cTECs) of Delta-like 4 (Dll4), a Notch ligand crucial for the commitment and differentiation of T cell progenitors in a dose-dependent manner. Consistent with this, sex steroid ablation (SSA) led to increased expression of Dll4 and its downstream targets. Importantly, SSA induced by luteinizing hormone-releasing hormone (LHRH) receptor antagonism bypassed the surge in sex steroids caused by LHRH agonists, the gold standard for clinical ablation of sex steroids, thereby facilitating increased Dll4 expression and more rapid promotion of thymopoiesis. Collectively, these findings not only reveal a novel mechanism underlying improved thymic regeneration upon SSA but also offer an improved clinical strategy for successfully boosting immune function.