Congenital tooth-bearing tumor of the eyelid leading to lacrimal system obstruction.

PURPOSE: We present an unusual case of a congenital lesion presenting with concomitant chronic dacryocystitis. The clinical presentation, examination, management, and histopathology are reviewed. OBSERVATIONS: A healthy male infant born at 37 weeks gestation presented with an isolated painless 5mm congenital mass of the left medial lower eyelid. Parents also reported episodic epiphora and discharge from the left eye. A surgical excision of the mass revealed an underlying dacryocystitis and the presence of a formed tooth. A dacryocystorhinostomy was performed together with a repair of the soft tissue defect. Histopathology revealed components of disorganized epithelial and mesenchymal tissues including a tooth, skeletal muscle, fat, fibrous tissue, nonkeratinized epithelium, and myelinated nerves. A diagnosis of an odontogenic choristoma of the eyelid was made. Furthermore, a lacrimal sac culture was positive for oxacillin-susceptible Staphylococcus aureus with pathological evidence of chronic dacryocystitis. CONCLUSIONS AND IMPORTANCE: Odontogenic choristoma is a very rare finding in the periocular region with only a few cases reported in the literature. Awareness of clinical findings from this case may allow for a more accurate clinical diagnosis and understanding of the embryologic mechanisms underpinning eyelid and nasolacrimal development. Timely management of this condition is critical to ensure normal oculofacial development and prevent future complications.

The Na+, K+-ATPase ß1 subunit regulates epithelial tight junctions via MRCKα.

An intact lung epithelial barrier is essential for lung homeostasis. The Na+, K+-ATPase (NKA), primarily serving as an ion transporter, also regulates epithelial barrier function via modulation of tight junctions. However, the underlying mechanism is not well understood. Here, we show that overexpression of the NKA ß1 subunit upregulates the expression of tight junction proteins, leading to increased alveolar epithelial barrier function by an ion transport-independent mechanism. Using IP and mass spectrometry, we identified a number of unknown protein interactions of the ß1 subunit, including a top candidate, myotonic dystrophy kinase-related cdc42-binding kinase α (MRCKα), which is a protein kinase known to regulate peripheral actin formation. Using a doxycycline-inducible gene expression system, we demonstrated that MRCKα and its downstream activation of myosin light chain is required for the regulation of alveolar barrier function by the NKA ß1 subunit. Importantly, MRCKα is expressed in both human airways and alveoli and has reduced expression in patients with acute respiratory distress syndrome (ARDS), a lung illness that can be caused by multiple direct and indirect insults, including the infection of influenza virus and SARS-CoV-2. Our results have elucidated a potentially novel mechanism by which NKA regulates epithelial tight junctions and have identified potential drug targets for treating ARDS and other pulmonary diseases that are caused by barrier dysfunction.

Adoptive transfer of immature myeloid cells lacking NF-κB p50 (p50-IMC) impedes the growth of MHC-matched high-risk neuroblastoma.

High-risk neuroblastomas harbor abundant myeloid cells that suppress antitumor immunity and support tumor growth. Macrophages lacking the inhibitory NF-κB p50 subunit adopt a pro-inflammatory phenotype. We now report that murine 9464D neuroblastoma cells, which express high levels of exogenous MYCN, grow slower in syngeneic p50(f/f);Lys-Cre mice that lack p50 in macrophages and neutrophils, compared with p50(f/f) littermates. Tumors in p50(f/f);Lys-Cre mice possess increased numbers of total and activated CD4+ and CD8+ T cells, and depletion of both of these T-cell populations accelerates tumor growth. Anti-PD-1 T-cell checkpoint blockade, or DNA methyltransferase and histone deacetylase inhibition, further slows tumor growth. In addition, adoptive transfer of immature myeloid cells lacking NF-κB p50 (p50-IMC), generated either from the bone marrow of p50-/- mice or via nucleofection of a p50 sgRNA:Cas9 complex into wild-type hematopoietic progenitors, also slowed growth of MHC-matched 9464D tumors but not of MHC-mismatched Neuro2A tumors. These findings further validate the utility of targeting myeloid NF-κB p50 as a strategy for cancer therapy and demonstrate activity of p50-IMC generated by gene editing of syngeneic marrow cells, a cell product relevant to clinical translation.

C/EBPα induces Ebf1 gene expression in common lymphoid progenitors.

C/EBPα is required for formation of granulocyte-monocyte progenitors (GMP) and also participates in B lymphopoiesis. The common lymphoid progenitor (CLP) and preproB populations but not proB cells express Cebpa, and pan-hematopoietic deletion of the +37 kb Cebpa enhancer using Mx1-Cre leads not only to reduced GMP but also to 2-fold reduced marrow preproB and >15-fold reduced proB and preB cells. We now show that IL7Rα-Cre-mediated deletion of the +37 kb Cebpa enhancer, which occurs in 89% of Ly6D+ and 65% of upstream Ly6D- CLP, leads to a 2-fold reduction of both preproB and proB cells, and a 3-fold reduction in preB cells, with no impact on GMP numbers. These data support a direct role for C/EBPα during B lineage development, with reduced enhancer deletion in Ly6D- CLP mediated by IL7Rα-Cre diminishing the effect on B lymphopoiesis compared to that seen with Mx1-Cre. Amongst mRNAs encoding key transcriptional regulators that initiate B lymphoid specification (PU.1, E2A, IKAROS, EBF1, FOXO1, and BACH2), only Ebf1 levels are altered in CLP upon Mx1-Cre-mediated Cebpa enhancer deletion, with Ebf1 reduced ~40-fold in Flt3+Sca-1intc-kitintIL7Rα+ CLP. In addition, Cebpa and Ebf1 RNAs were 4- and 14-fold higher in hCD4+ versus hCD4- CLP from Cebpa-hCD4 transgenic mice. Histone modification ChIP-Seq data for CLP indicate the presence of active, intronic Ebf1 enhancers located 270 and 280 kb upstream of the transcription start sites. We identified a cis element in this region that strongly binds C/EBPα using the electrophoretic mobility shift assay. Mutation of this C/EBPα-binding site in an Ebf1 enhancer-TK-luciferase reporter leads to a 4-fold reduction in C/EBPα-mediated trans-activation. These findings support a model of B lymphopoiesis in which induction of Ebf1 by C/EBPα in a subset of CLP contributes to initiation of B lymphopoiesis.

E-Liquid Containing a Mixture of Coconut, Vanilla, and Cookie Flavors Causes Cellular Senescence and Dysregulated Repair in Pulmonary Fibroblasts: Implications on Premature Aging.

Electronic cigarette (e-cig) usage has risen dramatically worldwide over the past decade. While they are touted as a safe alternative to cigarettes, recent studies indicate that high levels of nicotine and flavoring chemicals present in e-cigs may still cause adverse health effects. We hypothesized that an e-liquid containing a mixture of tobacco, coconut, vanilla, and cookie flavors would induce senescence and disrupt wound healing processes in pulmonary fibroblasts. To test this hypothesis, we exposed pulmonary fibroblasts (HFL-1) to e-liquid at varying doses and assessed cytotoxicity, inflammation, senescence, and myofibroblast differentiation. We found that e-liquid exposure caused cytotoxicity, which was accompanied by an increase in IL-8 release in the conditioned media. E-liquid exposure resulted in elevated senescence-associated beta-galactosidase (SA-ß-gal) activity. Transforming growth factor-ß1 (TGF-ß1) induced myofibroblast differentiation was inhibited by e-liquid exposure, resulting in decreased α-smooth muscle actin and fibronectin protein levels. Together, our data suggest that an e-liquid containing a mixture of flavors induces inflammation, senescence and dysregulated wound healing responses.

BRAF V600E-mutated metastatic pediatric Wilms tumor with complete response to targeted RAF/MEK inhibition.

Wilms tumor (WT) is the most common renal malignancy of childhood and accounts for 6% of all childhood malignancies. With current therapies, the 5-yr overall survival (OS) for children with unilateral favorable histology WT is greater than 85%. The prognosis is worse, however, for the roughly 15% of patients who relapse, with only 50%-80% OS reported in those with recurrence. Herein, we describe the extended and detailed clinical course of a rare case of a child with recurrent, pulmonary metastatic, favorable histology WT harboring a BRAF V600E mutation. The BRAF V600E mutation, commonly found in melanoma and other cancers, and previously undescribed in WT, has recently been reported by our group in a subset of epithelial-predominant WT. This patient, who was included in that series, presented with unilateral, stage 1, favorable histology WT and was treated with standard chemotherapy. Following the completion of therapy, the patient relapsed with pulmonary metastatic disease, that then again recurred despite an initial response to salvage chemotherapy and radiation. Next-generation sequencing (NGS) on the metastatic pulmonary nodule revealed a BRAF V600E mutation. After weighing the therapeutic options, a novel approach with dual BRAF/MEK inhibitor combination therapy was initiated. Complete radiographic response was observed following 4 months of therapy with dabrafenib and trametinib. At 12 months following the start of BRAF/MEK combination treatment, the patient continues with a complete response and has experienced minimal treatment-related side effects. This represents the first case, to our knowledge, of effective treatment with BRAF/MEK molecularly targeted therapy in a pediatric Wilms tumor patient.

Chemical Constituents Involved in E-Cigarette, or Vaping Product Use-Associated Lung Injury (EVALI).

The Centers for Disease Control declared e-cigarette, or vaping, product use-associated lung injury (EVALI) a national outbreak due to the high incidence of emergency department admissions and deaths. We have identified chemical constituents in e-cig counterfeit cartridges and compared these to medical-grade and CBD containing cartridges. Apart from vitamin E acetate (VEA) and tetrahydrocannabinol (THC), other potential toxicants were identified including solvent-derived hydrocarbons, silicon conjugated compounds, various terpenes, pesticides/plasticizers/polycaprolactones, and metals. This study provides additional insights into the chemicals associated with EVALI cartridges and thus may contribute to the underlying disease mechanism of acute lung injury.

NF-κB p50-deficient immature myeloid cell (p50-IMC) adoptive transfer slows the growth of murine prostate and pancreatic ductal carcinoma.

BACKGROUND: Macrophages and dendritic cells lacking the transcription factor nuclear factor kappa B p50 are skewed toward a proinflammatory phenotype, with increased cytokine expression and enhanced T cell activation; additionally, murine melanoma, fibrosarcoma, colon carcinoma, and glioblastoma grow slower in p50-/- mice. We therefore evaluated the efficacy of p50-negative immature myeloid cells (p50-IMCs) adoptively transferred into tumor-bearing hosts. Immature cells were used to maximize tumor localization, and pretreatment with 5-fluorouracil (5FU) was examined due to its potential to impair marrow production of myeloid cells, to target tumor myeloid cells and to release tumor neoantigens. METHODS: Wild-type (WT)-IMC or p50-IMC were generated by culturing lineage-negative marrow cells from WT or p50-/- mice in media containing thrombopoietin, stem cell factor and Flt3 ligand for 6 days followed by monocyte colony-stimulating factor for 1 day on ultralow attachment plates. Mice inoculated with Hi-Myc prostate cancer (PCa) cells or K-RasG12D pancreatic ductal carcinoma (PDC)-luciferase cells received 5FU followed 5 days later by three doses of 107 immature myeloid cells (IMC) every 3-4 days. RESULTS: PCa cells grew slower in p50-/- mice, and absence of host p50 prolonged the survival of mice inoculated orthotopically with PDC cells. IMC from Cytomegalovirus (CMV)-luciferase mice localized to tumor, nodes, spleen, marrow, and lung. 5FU followed by p50-IMC slowed PCa and PDC tumor growth, ~3-fold on average, in contrast to 5FU followed by WT-IMC, 5FU alone or p50-IMC alone. Slowed tumor growth was evident for 93% of PCa but only 53% of PDC tumors; we therefore focused on PCa for additional IMC analyses. In PCa, p50-IMC matured into F4/80+ macrophages, as well as CD11b+F4/80-CD11c+ conventional dendritic cells (cDCs). In both tumor and draining lymph nodes, p50-IMC generated more macrophages and cDCs than WT-IMC. Activated tumor CD8+ T cells were increased fivefold by p50-IMC compared with WT-IMC, and antibody-mediated CD8+ T cell depletion obviated slower tumor growth induced by 5FU followed by p50-IMC. CONCLUSIONS: 5FU followed by p50-IMC slows the growth of murine prostate and pancreatic carcinoma and depends on CD8+ T cell activation. Deletion of p50 in patient-derived marrow CD34+ cells and subsequent production of IMC for adoptive transfer may contribute to the therapy of these and additional cancers.

Personality Predictors of Communication Skills Among Orthopedic Surgery Residents.

INTRODUCTION: This study examined the relationship between personality traits and interpersonal communication skills among first-year orthopedic surgery residents. METHOD: This study performed a retrospective analysis on the data collected in the 2 phases among the 6 cohorts of first-year orthopedic surgery residents (n = 73) during a 6-year period at an urban academic medical hospital. Resident personality was assessed through self-report prior to entry into the program and included a total of 7 personality traits. These traits were broken down into 2 categories, day to day, or usual, tendencies, which measured personality traits when no stress was present and stress tendencies, which measured personality traits when stressed or fatigued. The "day to day" tendencies measured were Emotional Stability, Agreeableness, Conscientiousness and Openness) and "stress" tendencies measured were Excitable, Skeptical and Imaginative. Communication skills were measured across 4 specific dimensions of patient communication (Engage, Empathy, Educate, Enlist) in an Objective Structured Clinical Examination (OSCE). RESULTS: Multiple regression analyses showed that the personality traits identified as "stress" tendencies predicted performance on 2 of the 4 communication skills dimensions measured by the OSCE and accounted for up to 34.8% of the total variance in the ratings of empathic communication and up to 67.2% of the total variance in education-related communication. CONCLUSIONS: Our research identifies specific personality traits that affect resident communication skills related to patient education and empathy in simulated encounters. Three stress-related personality traits (Excitable, Skeptical, Imaginative) had a strong negative influence on communication skills, while day to day personality traits (Emotional Stability, Agreeableness, Conscientiousness) positively influenced communication skills.

HoxA9 binds and represses the Cebpa +8 kb enhancer.

C/EBPα plays a key role in specifying myeloid lineage development. HoxA9 is expressed in myeloid progenitors, with its level diminishing during myeloid maturation, and HOXA9 is over-expressed in a majority of acute myeloid leukemia cases, including those expressing NUP98-HOXD13. The objective of this study was to determine whether HoxA9 directly represses Cebpa gene expression. We find 4-fold increased HoxA9 and 5-fold reduced Cebpa in marrow common myeloid and LSK progenitors from Vav-NUP98-HOXD13 transgenic mice. Conversely, HoxA9 decreases 5-fold while Cebpa increases during granulocytic differentiation of 32Dcl3 myeloid cells. Activation of exogenous HoxA9-ER in 32Dcl3 cells reduces Cebpa mRNA even in the presence of cycloheximide, suggesting direct repression. Cebpa transcription in murine myeloid cells is regulated by a hematopoietic-specific +37 kb enhancer and by a more widely active +8 kb enhancer. ChIP-Seq analysis of primary myeloid progenitor cells expressing exogenous HoxA9 or HoxA9-ER demonstrates that HoxA9 localizes to both the +8 kb and +37 kb Cebpa enhancers. Gel shift analysis demonstrates HoxA9 binding to three consensus sites in the +8 kb enhancer, but no affinity for the single near-consensus site present in the +37 kb enhancer. Activity of a Cebpa +8 kb enhancer/promoter-luciferase reporter in 32Dcl3 or MOLM14 myeloid cells is increased ~2-fold by mutation of its three HOXA9-binding sites, suggesting that endogenous HoxA9 represses +8 kb Cebpa enhancer activity. In contrast, mutation of five C/EBPα-binding sites in the +8 kb enhancer reduces activity 3-fold. Finally, expression of a +37 kb enhancer/promoter-hCD4 transgene reporter is reduced ~2-fold in marrow common myeloid progenitors when the Vav-NUP98-HOXD13 transgene is introduced. Overall, these data support the conclusion that HoxA9 represses Cebpa expression, at least in part via inhibition of its +8 kb enhancer, potentially allowing normal myeloid progenitors to maintain immaturity and contributing to the pathogenesis of acute myeloid leukemia associated with increased HOXA9.

Upadacitinib as monotherapy in patients with active rheumatoid arthritis and inadequate response to methotrexate (SELECT-MONOTHERAPY): a randomised, placebo-controlled, double-blind phase 3 study.

BACKGROUND: Upadacitinib, an oral Janus kinase (JAK)1-selective inhibitor, showed efficacy in combination with stable background conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) in patients with rheumatoid arthritis who had an inadequate response to DMARDs. We aimed to evaluate the safety and efficacy of upadacitinib monotherapy after switching from methotrexate versus continuing methotrexate in patients with inadequate response to methotrexate. METHODS: SELECT-MONOTHERAPY was conducted at 138 sites in 24 countries. The study enrolled adults (≥18 years) who fulfilled the 2010 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for rheumatoid arthritis. Patients with active rheumatoid arthritis despite stable methotrexate were randomly assigned 2:2:1:1 to switch to once-daily monotherapy of of upadacitinib or to continue methotrexate at their existing dose as blinded study drug; starting from week 14, patients assigned to continue methotrexate were switched to 15 mg or 30 mg once-daily upadacitinib per prespecified random assignment at baseline. The primary endpoints in this report are proportion of patients achieving 20% improvement in the ACR criteria (ACR20) at week 14, and proportion achieving low disease activity defined as 28-joint Disease Activity Score using C-reactive protein (DAS28[CRP]) of 3·2 or lower, both with non-responder imputation at week 14. Outcomes were assessed in patients who received at least one dose of study drug. This study is active but not recruiting and is registered with ClinicalTrials.gov, number NCT02706951. FINDINGS: Patients were screened between Feb 23, 2016, and May 19, 2017 and 648 were randomly assigned to treatment. 598 (92%) completed week 14. At week 14, an ACR20 response was achieved by 89 (41%) of 216 patients (95% CI 35-48) in the continued methotrexate group, 147 (68%) of 217 patients (62-74) receiving upadacitinib 15 mg, and 153 (71%) of 215 patients (65-77) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). DAS28(CRP) 3·2 or lower was met by 42 (19%) of 216 (95% CI 14-25) in the continued methotrexate group, 97 (45%) of 217 (38-51) receiving upadacitinib 15 mg, and 114 (53%) of 215 (46-60) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). Adverse events were reported in 102 patients (47%) on continued methotrexate, 103 (47%) on upadacitinib 15 mg, and 105 (49%) on upadacitinib 30 mg. Herpes zoster was reported by one (<1%) patient on continued methotrexate, three (1%) on upadacitinib 15 mg, and six (3%) on upadacitinib 30 mg. Three malignancies (one [<1%] on continued methotrexate, two [1%] on upadacitinib 15 mg), three adjudicated major adverse cardiovascular events (one [<1%] on upadacitinib 15 mg, two [<1%] on upadacitinib 30 mg), one adjudicated pulmonary embolism (<1%; upadacitinib 15 mg), and one death (<1%; upadacitinib 15 mg, haemorrhagic stroke [ruptured aneurysm]) were reported in the study. INTERPRETATION: Upadacitinib monotherapy showed statistically significant improvements in clinical and functional outcomes versus continuing methotrexate in this methotrexate inadequate-responder population. Safety observations were similar to those in previous upadacitinib rheumatoid arthritis studies. FUNDING: AbbVie Inc, USA.

Personality Assessment in Orthopaedic Surgery: AOA Critical Issues.

Personality assessment tools are used effectively in many arenas of business, but they have not been embraced by the medical profession. There is increasing evidence that these tools have promise for helping to match resident candidates to specific fields of medicine, for mentoring residents, and for developing improved leadership in our field. This paper reviews many aspects of personality assessment tools and their use in orthopaedic surgery.

T-cell lymphoblastic lymphoma involving the ocular adnexa: report of two cases and review of the current literature.

The majority of ocular adnexal lymphomas are B-cell in origin. We report two cases of T-cell lymphoblastic lymphoma (T-LBL) involving the ocular adnexa. One patient presented with a painless pink conjunctival lesion and inferior orbital fullness. The second patient presented with a painless orbital mass. The diagnoses were confirmed by histopathology and immunohistochemistry. Both patients had extensive multifocal lesions during staging. Prompt intensified chemotherapy regimens were initiated. T-LBL is an aggressive disease with poor prognosis. This report emphasizes the importance of timely diagnosis by the ophthalmologist with co-management and treatment with an oncologist.

Mass spectrometry based detection of common vitellogenin peptides across fish species for assessing exposure to estrogenic compounds in aquatic environments.

The identification of myriad of chemicals in the environment that mimic hormones and affect the endocrine functions of exposed organism is a daunting analytical challenge for environmental scientists and engineers. Many of these endocrine disrupting chemicals (EDCs) are present at very low concentrations in the aquatic systems, but yet affect the metabolic, developmental, and reproductive functions in exposed fish and wildlife. Vitellogenin (VTG) protein is a widely used biomarker in fish for assessing exposure to EDCs, and is commonly measured using species-specific immunochemical techniques. In this study, we developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method that can measure common peptides from digested VTG in multiple fish species. In the initial experiments using high resolution mass spectrometry, two peptides (ALHPELR and FIELIQLLR) were identified as common fragments in the digested VTG protein isolated from three different fish species (Pimephales promelas, Micropterus salmoides, and Fundulus heteroclitus). Then, a quantitative analysis using LC-MS/MS under selected reaction monitoring mode was developed for the detection of these two peptides in trypsin-digested plasma from female fish (positive control), estrogen-exposed male fish (test sample), and unexposed male fish (negative control) using two of the same species used for identifying the common peptides (P. promelas, and M. salmoides) and one new species (Ameiurus nebulosus) that was not included during the selection of peptides. Results from this study demonstrate the potential of LC-MS/MS as an effective cross-species method to detect VTG in fish, which can be an alternative analytical technique for assessing endocrine disruption in multiple fish species.

Hypertensive crisis with massive retinal and choroidal infarction: A case update.

PURPOSE: We report an update on a recently published case of uncontrolled hypertension secondary to immunoglobulin A (IgA) nephropathy resulting in massive bilateral retinal and choroidal infarction. OBSERVATIONS: In our previous report, we presented a 30-year old female with end-stage renal disease who complained of painless vision loss after many missed hemodialysis. The patient was found to be in hypertensive crisis resulting in massive retinal and choroidal infarction with severe vision loss in both eyes. The patient was treated with pan-retinal photocoagulation (PRP) with intravitreal Bevacizumab and was subsequently lost to follow-up. In this update, we report the complications that followed. After many months, she presented to clinic with a blind painful right eye. She was found to have a further decrease in vision with neovascular glaucoma in the right eye and a tractional retinal detachment in the left eye. The patient ultimately elected for enucleation of her right eye. Immunohistopathology revealed IgA deposition, confirming the presumed diagnosis of IgA nephropathy, previously unconfirmable through renal biopsy. CONCLUSIONS AND IMPORTANCE: There is a strong association between severity of retinopathy and level of kidney function. Although a rare presentation, hypertensive retinopathy is a common complication of end-stage renal disease and can be a devastating process as emphasized by this report. Those with auto-immune renal disease, such as IgA nephropathy, are at higher risk for retino-choroidal complications. It should remind all ophthalmologists and clinicians on the necessity of closer eye examinations for these patients, particularly for those with auto-immune renal disease.

Progression from the Common Lymphoid Progenitor to B/Myeloid PreproB and ProB Precursors during B Lymphopoiesis Requires C/EBPα.

The C/EBPα transcription factor is required for myelopoiesis, with prior observations suggesting additional contributions to B lymphopoiesis. Cebpa expression is evident in common lymphoid progenitor (CLP) and preproB cells but is absent in proB and preB cells. We previously observed that marrow lacking the Cebpa +37 kb enhancer is impaired in producing B cells upon competitive transplantation. Additionally, a Cebpa enhancer/promoter-hCD4 transgene is expressed in B/myeloid CFU. Extending these findings, pan-hematopoietic murine Cebpa enhancer deletion using Mx1-Cre leads to expanded CLP, fewer preproB cells, markedly reduced proB and preB cells, and reduced mature B cells, without affecting T cell numbers. In contrast, enhancer deletion at the proB stage using Mb1-Cre does not impair B cell maturation. Further evaluation of CLP reveals that the Cebpa transgene is expressed almost exclusively in Flt3+ multipotent CLP versus B cell-restricted Flt3- CLP. In vitro, hCD4+ preproB cells produce both B and myeloid cells, whereas hCD4- preproB cells only produce B cells. Additionally, a subset of hCD4- preproB cells express high levels of RAG1-GFP, as seen also in proB cells. Global gene expression analysis indicates that hCD4+ preproB cells express proliferative pathways, whereas B cell development and signal transduction pathways predominate in hCD4- preproB cells. Consistent with these changes, Cebpa enhancer-deleted preproB cells downmodulate cell cycle pathways while upregulating B cell signaling pathways. Collectively, these findings indicate that C/EBPα is required for Flt3+ CLP maturation into preproB cells and then for proliferative Cebpaint B/myeloid preproB cells to progress to Cebpalo B cell-restricted preproB cells and finally to Cebpaneg proB cells.

Deciphering the mechanism of O2 reduction with electronically tunable non-heme iron enzyme model complexes.

A homologous series of electronically tuned 2,2',2''-nitrilotris(N-arylacetamide) pre-ligands (H3LR ) were prepared (R = NO2, CN, CF3, F, Cl, Br, Et, Me, H, OMe, NMe2) and some of their corresponding Fe and Zn species synthesized. The iron complexes react rapidly with O2, the final products of which are diferric mu-oxo bridged species. The crystal structure of the oxidized product obtained from DMA solutions contain a structural motif found in some diiron proteins. The mechanism of iron mediated O2 reduction was explored to the extent that allowed us to construct an empirically consistent rate law. A Hammett plot was constructed that enabled insightful information into the rate-determining step and hence allows for a differentiation between two kinetically equivalent O2 reduction mechanisms.

Absence of host NF-κB p50 induces murine glioblastoma tumor regression, increases survival, and decreases T-cell induction of tumor-associated macrophage M2 polarization.

High-grade gliomas harbor abundant myeloid cells that suppress anti-tumor immunity and support tumor growth. Targeting transcription factors, such as NF-κB p50, that mediate suppressive myeloid M2 polarization may prove therapeutic. GL261-Luc glioblastoma cells were inoculated into wild-type and p50-/- mice, followed by analysis of tumor growth, survival, tumor myeloid cells, and T cells. The absence of host p50 slows tumor growth and enables regression in 30% of recipients, leading to prolonged survival. Tumors developing in p50-/- mice possess a greater concentration of tumor-infiltrating myeloid cells (TIMs) than those in wild-type mice. TIMs are predominantly F4/80hi macrophages which, along with tumor-associated microglia, express increased pro-inflammatory M1 and reduced immune-suppressive M2 markers. In p50-/- mice, total tumor CD4 T cells are threefold more abundant, whereas CD8 T-cell numbers are unchanged, and both produce increased IFNγ and Granzyme B. Naïve splenic p50-/- CD8 T cells manifest increased activation, whereas naïve p50-/- and WT CD4 T cells show similar Th1, Th2, and Th17 polarization. Antibody targeting CD4, but not CD8, fully obviates the p50-/- survival advantage. Combined CD4 and CD8 T-cell depletion reverses myeloid M2 polarization in wild-type hosts, without affecting myeloid M1 polarization in p50-/- hosts. Finally, gliomas grow similarly in p50(f/f) and p50(f/f);Lysozyme-Cre mice, the latter having reduced p50 specifically in myeloid cells and tumor microglia. Thus, high-grade glioma T cells play a key role in directing M2 polarization of tumor myeloid cells, and reducing NF-κB p50 in both tumor myeloid cells and T cells may contribute to glioma therapy.