Increased exposure to Ozone (O3) is associated with adverse health effects in individuals afflicted with respiratory diseases. Surfactant protein-A (SP-A), encoded by SP-A1 and SP-A2, is the largest ...protein component in pulmonary surfactant and is functionally impaired by O3-oxidation.
We used humanized SP-A2 transgenic mice with allelic variation corresponding to a glutamine (Q) to lysine (K) amino acid substitution at position 223 in the lectin domain to determine the impact of this genetic variation in regards to O3 exposure.
Mice were exposed to 2ppm O3 or Filtered Air (FA) for 3 hours and 24 hrs post-challenge pulmonary function tests and other parameters associated with inflammation were assessed in the bronchoalveolar lavage (BAL) fluid and lung tissue. Additionally, mouse tracheal epithelial cells were cultured and TEER measurements recorded for each genotype to determine baseline epithelial integrity.
Compared to FA, O3 exposure led to significantly increased sensitivity to methacholine challenge in all groups of mice. SP-A2 223Q variant mice were significantly protected from O3-induced AHR compared to SP-A-/- and SP-A2 223K mice. Neutrophilia was observed in all genotypes of mice post O3-exposure, however, SP-A2 223Q mice had a significantly lower percentage of neutrophils compared to SP-A-/- mice. Albumin levels in BAL were unchanged in O3-exposed SP-A2 223Q mice compared to their FA controls, while levels were significantly increased in all other genotypes of O3-exposed mice. SP-A 223Q MTECS has significant higher TEER values than all other genotypes, and WT MTECS has significantly higher TEER than the SP-A KO and SP-A 223K MTECS.
Taken together, our study suggests that expression of a glutamine (Q) as position 223 in SP-A2, as opposed to expression of lysine (K), is more protective in acute exposures to ozone and results in attenuated O3-induced AHR, neutrophilia, and vascular permeability.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Studies have shown that club cell secretory protein (CC16) plays important protective roles in the lungs, yet its complete biological functions are unclear. We devised a translational mouse model in ...order to investigate the impact of early life infections, in the context of CC16 deficiency, on lung function in adult mice. CC16 sufficient (WT) and deficient (CC16
) mice were infected with Mycoplasma pneumoniae (Mp) as weanlings and assessed as adults (
arly
ife
nfection
odel; ELIM) and compared to adult mice infected for only 3 days (
dult
nfection
odel; AIM). CC16
Mp-infected mice had significantly increased airway hyperresponsiveness (AHR) in both models compared to WT mice. However, CC16
mice infected in early life (ELIM) displayed significantly increased AHR compared to CC16
mice infected in adulthood (AIM). In stark contrast, lung function in ELIM WT mice returned to levels similar to saline-treated controls. While WT mice cleared Mp infection in the ELIM, CC16
mice remained colonized with Mp throughout the model, which likely contributed to increased airway remodeling and persistence of
expression. When CC16
mouse tracheal epithelial cells (MTECs) were infected with Mp, increased Mp colonization and collagen gene expression were also detected compared to WT cells, suggesting that CC16 plays a protective role during Mp infection, in part through epithelial-driven host defense mechanisms.
Background and Purpose
Asthma is a heterogenous disease strongly associated with inflammation that has many different causes and triggers. Current asthma treatments target symptoms such as ...bronchoconstriction and airway inflammation. Despite recent advances in biological therapies, there remains a need for new classes of therapeutic agents with novel, upstream targets. The proteinase‐activated receptor‐2 (PAR2) has long been implicated in allergic airway inflammation and asthma and it remains an intriguing target for novel therapies. Here, we describe the actions of C781, a newly developed low MW PAR2 biased antagonist, in vitro and in vivo in the context of acute allergen exposure.
Experimental Approach
A human bronchial epithelial cell line expressing PAR2 (16HBE14o‐ cells) was used to evaluate the modulation in vitro, by C781, of physiological responses to PAR2 activation and downstream β‐arrestin/MAPK and Gq/Ca2+ signalling. Acute Alternaria alternata sensitized and challenged mice were used to evaluate C781 as a prophylactically administered modulator of airway hyperresponsiveness, inflammation and mucus overproduction in vivo.
Key Results
C781 reduced in vitro physiological signalling in response to ligand and proteinase activation. C781 effectively antagonized β‐arrestin/MAPK signalling without significant effect on Gq/Ca2+ signalling in vitro. Given prophylactically, C781 modulated airway hyperresponsiveness, airway inflammation and mucus overproduction of the small airways in an acute allergen‐challenged mouse model.
Conclusion and Implications
Our work demonstrates the first biased PAR2 antagonist for β‐arrestin/MAPK signalling. C781 is efficacious as a prophylactic treatment for allergen‐induced airway hyperresponsiveness and inflammation in mice. It exemplifies a key pharmacophore for PAR2 that can be optimized for clinical development.
Menopause-associated asthma impacts a subset of women, tends to be more severe, and is less responsive to current treatments. We recently developed a model of menopause-associated asthma using ...4-Vinylcyclohexene Diepoxide (VCD) and house dust mites (HDM). The goal of this study was to uncover potential biomarkers and drivers of menopause-onset asthma by assessing serum and bronchoalveolar lavage fluid (BALF) samples from mice with and without menopause and HDM challenge by large-scale targeted metabolomics. Female mice were treated with VCD/HDM to model menopause-associated asthma, and serum and BALF samples were processed for large-scale targeted metabolomic assessment. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to examine metabolites of potential biological significance. We identified over 50 individual metabolites, impacting 46 metabolic pathways, in the serum and BALF that were significantly different across the four study groups. In particular, glutamate, GABA, phosphocreatine, and pyroglutamic acid, which are involved in glutamate/glutamine, glutathione, and arginine and proline metabolisms, were significantly impacted in the menopausal HDM-challenged mice. Additionally, several metabolites had significant correlations with total airway resistance including glutamic acid, histamine, uridine, cytosine, cytidine, and acetamide. Using metabolic profiling, we identified metabolites and metabolic pathways that may aid in discriminating potential biomarkers for and drivers of menopause-associated asthma.
The mathematical method used to calculate chest compression (CC) rate during cardiopulmonary resuscitation varies in the literature and across device manufacturers. The objective of this study was to ...determine the variability in calculated CC rates by applying four published methods to the same dataset.
This study was a secondary investigation of the first 200 pediatric cardiac arrest events with invasive arterial line waveform data in the ICU-RESUScitation Project (NCT02837497). Instantaneous CC rates were calculated during periods of uninterrupted CCs. The defined minimum interruption length affects rate calculation (e.g., if an interruption is defined as a break in CCs ≥ 2 s, the lowest possible calculated rate is 30 CCs/min). Average rates were calculated by four methods: 1) rate with an interruption defined as ≥ 1 s; 2) interruption ≥ 2 s; 3) interruption ≥ 3 s; 4) method #3 excluding top and bottom quartiles of calculated rates. American Heart Association Guideline-compliant rate was defined as 100–120 CCs/min. A clinically important change was defined as ±5 CCs/min. The percentage of events and epochs (30 s periods) that changed Guideline-compliant status was calculated.
Across calculation methods, mean CC rates (118.7–119.5/min) were similar. Comparing all methods, 14 events (7%) and 114 epochs (6%) changed Guideline-compliant status.
Using four published methods for calculating CC rate, average rates were similar, but 7% of events changed Guideline-compliant status. These data suggest that a uniform calculation method (interruption ≥ 1 s) should be adopted to decrease variability in resuscitation science.
While most individuals with asthma experience similar symptoms, the time of onset, severity, and underlying mechanisms of disease vary greatly. This has led to the development of unique asthma ...endotypes and the characterization of asthma into varying subtypes such as allergic asthma, exercise induced asthma, late-onset neutrophilic asthma, and others as discussed in Chapter 1. These endotypes often require precise therapies that target the distinct cellular and molecular mechanisms driving the disease. Menopause associated asthma is a subtype of asthma that has been described in clinical settings but has yet to be characterized as a unique asthma endotype. Individuals experiencing menopause-associated asthma tend to have severe exacerbations, often requiring hospitalization, and respond poorly to standard treatment. Current literature describing menopause associated asthma is sparse, and researchers have been unable to develop an appropriate animal model to study the disease. The studies reported here describe the development of a novel mouse model of menopause associated asthma, as well as insights into the cellular and molecular mechanisms at play. Chapter 2 details the development and assessment of this new model in which we combined the Vinylcyclohexene Diepoxide (VCD) model of menopause with the house dust mite (HDM) model of asthma, to develop a novel model of menopause associated asthma in mice that closely mimics findings that have been detailed in the human condition. In this model, the mice demonstrated significant decreases in airway function in menopausal asthmatic mice, as well as increased neutrophil recruitment in the BALF, infiltration of inflammatory cells in the alveolar spaces, and excessive collagen production surrounding the airways, indicative of airway remodeling. In addition, as compared to asthmatic mice only, menopausal asthmatic mice had increased levels of non-Th2 cytokines, specifically Th-17, and elevated Th-9 T-cells in their lungs, suggesting a mixed Th-2 and non-Th-2 inflammatory response. Chapter 3 describes results from large-scale targeted metabolomic analysis of BALF and serum samples from menopausal asthmatic mice, in which we identified over 50 individual metabolites, affecting 46 metabolic pathways that were significantly different across the experimental groups. Of particular interest were pyroglutamic acid, glutamate, GABA, and phosphocreatine, which are intermediates in glutamate and glutamine metabolism, glutathione metabolism, and arginine and proline metabolism. Additionally, acetamide, cytidine, cytosine, glutamic acid, and uridine all had significant positive correlations with airway hypersensitivity, while histamine had a significant negative correlation. The metabolites and pathways described may serve as potential biomarkers for identification of menopause associated asthma or serve as mechanistic targets for future therapeutic intervention. Lastly, in Chapter 4 we performed estrogen replacement therapy on menopausal asthmatic mice in an attempt to attenuate the heightened asthmatic responses observed in the model. However, estrogen had the opposite effect, further decreasing airway function in menopausal animals. Estrogen replacement also had an interesting effect on airway inflammation, reducing eosinophilic inflammation while neutrophilic inflammation remained constant. Estrogen replacement also impacted airway epithelial cell integrity and differentiation in mouse tracheal epithelial cell cultures, which indicates that hormonal regulation could impact lung function at the level of the epithelium. Overall, the results from this work demonstrate the importance of the development of a novel mouse model of menopause associated asthma. We described unique, non-Th-2 inflammation in menopausal asthmatic animals, as well as the metabolomic profiles in the BALF and serum. In addition, we showed that estrogen replacement in menopausal mice does not aid in relieving deficits in airway function. As discussed in Chapter 5, this work lays the foundation for future research into the pathophysiological mechanisms behind menopause associated asthma, in hopes of developing precision therapies for a sub-group of asthmatics who have few treatment options.
Pediatric nonaortic arterial aneurysms are uncommon diagnoses and can be affiliated with underlying conditions, which include neurofibromatosis I, Ehlers-Danlos type IV syndrome, Kawasaki disease, ...Marfan syndrome, and Loeys-Dietz, polyarteritis nodosa, as well as Klippel-Trenauny syndrome. The standard of care has been early surgical excision and arterial reconstruction when indicated. This report details a case of recurrent brachial artery aneurysm in a 2-year-old boy despite multiple attempts at excision and reconstruction. Such recurrences were seen as rapidly as 3 months postoperatively. Ultimately, a Gore-Tex conduit was used to reinforce a reversed saphenous vein graft repair. There has been no evidence of recurrent disease during the 18-month follow-up period.
The free fibula flap (FFF) is a preferred option for adult mandibular reconstruction. Due to skeletal immaturity, its routine use in pediatric patients remains in question. Inconsistencies regarding ...the ability of the FFF to grow in concordance with the patients' natural growth currently exist in the literature. The purpose of this report is to quantify mandibular growth in a young patient undergoing partial hemi-mandibular reconstruction with a FFF utilizing advanced three-dimensional software.
A 2-year old underwent left hemi-mandibular reconstruction with a FFF following resection of a desmoid tumor. The condyle was preserved. Using 3D software, changes in mandibular growth and morphology were evaluated based on preoperative (2.1 years old) and postoperative (2.5 years and 5.2 years old) computed tomography imaging.
Mandibular growth occurred throughout the mandible in both postoperative evaluations. Greatest growth was seen in the ramus height. Fibula growth was also seen when comparing measurements to the virtual surgical planning guide. A novel parts comparison analysis revealed the greatest growth potential occurred at the condyle.
Providing an objective evaluation using 3D software, we have demonstrated growth throughout the reconstructed mandible, with greatest growth occurring at the preserved condyle. Despite scientific limitations of our study, the potential for mandibular growth appears to remain after FFF reconstruction, offering successful functional and cosmetic outcomes.
Background
Intraoperative radiation therapy (IORT) has been investigated for patients with low-risk, early-stage breast cancer. The The North American experience was evaluated by TARGIT-R ...(retrospective) to provide outcomes for patients treated in “real-world” clinical practice with breast IORT. This analysis presents a 5-year follow-up assessment.
Methods
TARGIT-R is a multi-institutional retrospective registry of patients who underwent lumpectomy and IORT between the years 2007 and 2013. The primary outcome of the evaluation was ipsilateral breast tumor recurrence (IBTR).
Results
The evaluation included 667 patients with a median follow-up period of 5.1 years. Primary IORT (IORT at the time of lumpectomy) was performed for 72%, delayed IORT (after lumpectomy) for 3%, intended boost for 8%, and unintended boost (primary IORT followed by whole-breast radiation) for 17% of the patients. At 5 years, IBTR was 6.6% for all the patients, with 8% for the primary IORT cohort and 1.7% for the unintended-boost cohort. No recurrences were identified in the delayed IORT or intended-boost cohorts. Noncompliance with endocrine therapy (ET) was associated with higher IBTR risk (hazard ratio HR, 3.67). Patients treated with primary IORT who were complaint with ET had a 5-year IBTR rate of 3.9%.
Conclusion
The local recurrence rates in this series differ slightly from recent results of randomized IORT trials and are notably higher than in previous published studies using whole-breast radiotherapy for similar patients with early-stage breast cancer. Understanding differences in this retrospective series and the prospective trials will be critical to optimizing patient selection and outcomes going forward.
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