180 research outputs found
Nonnegative Trigonometric Sums
AbstractWe obtain estimates for ∑|k|≤N|ck|2 and ∑|k|≤N|ck|4, when ∑|k|≤Nckeitkx≥0, t0=0, and c0=1. It is shown that∑k=−NN|ck|4≤M/b+1and∑k=−NN|ck|2≤(2N+1)(M/b+1),where M=max|tk| and b=min{|tj|:j≠0}. When the cks are known to be nonnegative, the inequality∑k=−NN|ck|2≤M/b+1is established
Crawling with virus: Translational insights from a neonatal mouse model on the pathogenesis of respiratory syncytial virus in infants
© 2015, American Society for Microbiology. The infant immune response to respiratory syncytial virus (RSV) remains incompletely understood. Here we review the use of a neonatal mouse model of RSV infection to mimic severe infection in human infants. We describe numerous age-specific responses, organized by cell type, observed in RSV-infected neonatal mice and draw comparisons (when possible) to human infants
Building a better neonatal mouse model to understand infant respiratory syncytial virus disease
© 2015 You et al. Background: Respiratory syncytial virus (RSV) is the number one cause of lower respiratory tract infection in infants; and severe RSV infection in infants is associated with asthma development. Today, there are still no vaccines or specific antiviral therapies against RSV. The mechanisms of RSV pathogenesis in infants remain elusive. This is partly due to the fact that the largely-used mouse model is semi-permissive for RSV. The present study sought to determine if a better neonatal mouse model of RSV infection could be obtained using a chimeric virus in which the F protein of A2 strain was replaced with the F protein from the line 19 clinical isolate (rA2-19F). Methods: Five-day-old pups were infected with the standard laboratory strain A2 or rA2-19F and various immunological and pathophysiological parameters were measured at different time points post infection, including lung histology, bronchoalveolar lavage fluid (BALF) cellularity and cytokines, pulmonary T cell profile, and lung viral load. A cohort of infected neonates were allowed to mature to adulthood and reinfected. Pulmonary function, BALF cellularity and cytokines, and T cell profiles were measured at 6 days post reinfection. Results: The rA2-19F strain in neonatal mice caused substantial lung pathology including interstitial inflammation and airway mucus production, while A2 caused minimal inflammation and mucus production. Pulmonary inflammation was characterized by enhanced Th2 and reduced Th1 and effector CD8+ T cells compared to A2. As with primary infection, reinfection with rA2-19F induced similar but exaggerated Th2 and reduced Th1 and effector CD8+ T cell responses. These immune responses were associated with increased airway hyperreactivity, mucus hyperproduction and eosinophilia that was greater than that observed with A2 reinfection. Pulmonary viral load during primary infection was higher with rA2-19F than A2. Conclusions: Therefore, rA2-19F caused enhanced lung pathology and Th2 and reduced effector CD8+ T cell responses compared to A2 during initial infection in neonatal mice and these responses were exacerbated upon reinfection. The exact mechanism is unknown but appears to be associated with increased pulmonary viral load in rA2-19F vs. A2 infected neonatal lungs. The rA2-19F strain represents a better neonatal mouse model of RSV infection
Brain metastasis from urachal carcinoma: the importance of locally aggressive treatment
We present the case of a 52 years old woman who developed multiple brain metastasis after cystectomy with anterior exenteration and chemotherapy. She received whole-brain radiotherapy with 20 gray in 5 sessions. On magnetic resonance imaging 8 weeks after radiotherapy she showed a regression of some lesions while others responded only partially. This case-report and a review of the literature show the importance of aggressive local treatment in patients with brain metastasis from urachal carcinoma
Altered gut microbiota in infants is associated with respiratory syncytial virus disease severity
© 2020 The Author(s). Background: Respiratory syncytial virus (RSV) is the number one cause of lower respiratory tract infections in infants. There are still no vaccines or specific antiviral therapies against RSV, mainly due to the inadequate understanding of RSV pathogenesis. Recent data suggest a role for gut microbiota community structure in determining RSV disease severity. Our objective was to determine the gut microbial profile associated with severe RSV patients, which could be used to help identify at-risk patients and develop therapeutically protective microbial assemblages that may stimulate immuno-protection. Results: We enrolled 95 infants from Le Bonheur during the 2014 to 2016 RSV season. Of these, 37 were well-babies and 58 were hospitalized with RSV. Of the RSV infected babies, 53 remained in the pediatric ward (moderate) and 5 were moved to the pediatric intensive care unit at a later date (severe). Stool samples were collected within 72 h of admission; and the composition of gut microbiota was evaluated via 16S sequencing of fecal DNA. There was a significant enrichment in S24_7, Clostridiales, Odoribacteraceae, Lactobacillaceae, and Actinomyces in RSV (moderate and severe) vs. controls. Patients with severe RSV disease had slightly lower alpha diversity (richness and evenness of the bacterial community) of the gut microbiota compared to patients with moderate RSV and healthy controls. Beta diversity (overall microbial composition) was significantly different between all RSV patients (moderate and severe) compared to controls and had significant microbial composition separating all three groups (control, moderate RSV, and severe RSV). Conclusions: Collectively, these data demonstrate that a unique gut microbial profile is associated with RSV disease and with severe RSV disease with admission to the pediatric intensive care unit. More mechanistic experiments are needed to determine whether the differences observed in gut microbiota are the cause or consequences of severe RSV disease
Elevated levels of type 2 respiratory innate lymphoid cells in human infants with severe respiratory syncytial virus bronchiolitis
© 2019 by the American Thoracic Society. Rationale: Studies of the immune responses at the site of respiratory syncytial virus (RSV) infection are sparse despite nearly five decades of research into understanding RSV disease. Objectives: To investigate the role of mucosal innate immune responses to RSV and respiratory viral load in infants hospitalized with the natural disease. Methods: Cytokines, viral load, and type 2 innate lymphoid cell (ILC2) levels in nasal aspirates, collected within 24 hours of enrollment, from infants hospitalized with RSV infection were quantified. Measurements and Main Results: RSV severity in infants was categorized based on admission to the general ward (moderate) or the pediatric ICU (severe). Evaluable subjects included 30 patients with severe and 63 patients with moderate disease (median age, 74 d; range, 9-297 d). ILC2s were found in the nasal aspirates of patients with severe disease (0.051% of total respiratory CD451 cells) to a significantly greater extent than in patients with moderate disease (0.018%, P = 0.004). Levels of IL-4, IL-13, IL-33, and IL-1b were significantly higher in nasal aspirates of patients with severe disease compared with those of patients with moderate disease. Factors associated with disease severity were gestational age (odds ratio, 0.49; 95% confidence interval, 0.29-0.82; P = 0.007) and IL-4 (odds ratio, 9.67; 95% confidence interval, 2.45-38.15; P = 0.001). Conclusions: This study shows, for the first time, that elevated levels of ILC2s is associated with infant RSV severity. The findings highlight the dominance of type-2 responses to RSV infection in infants and suggest an important role of ILC2 in shaping the immune response early during RSV infection
Urachal carcinoma presenting with chronic mucusuria: a case report
Urachal adenocarcinoma is a rare tumor and represents 0.17–0.34% of all bladder tumors. It has an insidious course and variable clinical presentation. We present a case report of a 58 year old white male with an urachal cyst who suffered irritative voiding symptoms and long term mucusuria, since childhood. After surgical removal of the cyst with a partial cystectomy a mucus adenocarcinoma was diagnosed histologically
IL-4Rα on dendritic cells in neonates and Th2 immunopathology in respiratory syncytial virus infection
© Society for Leukocyte Biology. Respiratory syncytial virus (RSV) is one of the leading causes of bronchiolitis in children, and severe RSV infection early in life has been associated with asthma development. Using a neonatal mouse model, we have shown that down-regulation of IL-4 receptor α (IL-4Rα) with antisense oligonucleotides in the lung during neonatal infection protected from RSV immunopathophysiology. Significant down-regulation of IL-4Rα was observed on pulmonary CD11b+ myeloid dendritic cells (mDCs) suggesting a role for IL-4Rα on mDCs in the immunopathogenesis of neonatal RSV infection. Here, we demonstrated that neonatal CD11b+ mDCs expressed higher levels of IL-4Rα than their adult counterparts. Because CD11b+ mDCs mainly present antigens to CD4+ T cells, we hypothesized that increased expression of IL- 4Rα on neonatal CD11b+ mDCs was responsible for Th2 - biased RSV immunopathophysiology. Indeed, when IL-4Rα was selectively deleted from CD11b+ mDCs, the immunopathophysiology typically observed following RSV reinfection was ablated, including Th2 inflammation, airway-mucus hyperproduction, and pulmonary dysfunction. Further, overexpression of IL-4Rα on adult CD11b+ DCs and their adoptive transfer into adult mice was able to recapitulate the Th2-biased RSV immunopathology typically observed only in neonates infected with RSV. IL-4Rα levels on CD11c+ cells were inversely correlated with maturation status of CD11b+ mDCs upon RSV infection. Our data demonstrate that developmentally regulated IL-4Rα expression is critical for the maturity of pulmonary CD11b+ mDCs and the Th2-biased immunopathogenesis of neonatal RSV infection
- …