Publications by authors named "Bjornson C"

Objectives: Although croup is a common respiratory illness, there is little published regarding symptom course. We aimed to assess symptom progression and caregiver burden, and whether age, sex or season and initial severity of disease are associated with symptom duration.

Design, Setting And Participants: We conducted a secondary analysis of two Canadian prospective cohorts of children 0-16 years old diagnosed with croup; one recruited from a paediatric emergency department (ED) (307 children) between November 1999 and March 2000, and the other from 26 general EDs (1214 children) between September 2002 and April 2006.

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is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and small-colony-variants. The inoculum effect (IE) is characterized by reduced β-lactam susceptibility when assessed at high inoculum.

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Esophageal Atresia/Tracheoesophageal Atresia (EA/TEF) is a multisystem congenital anomaly. Historically, children with EA/TEF lack coordinated care. A multidisciplinary clinic was established in 2005 to provide coordinated care and improve access to outpatient care.

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Article Synopsis
  • Phasing of heterozygous alleles is essential for interpreting the effects of genetic variations related to cystic fibrosis (CF), and researchers sequenced 477 CF individuals to construct haplotypes using linked-read sequencing.
  • The resulting haplotypes are visualized in an interactive web app called CFTbaRcodes, allowing for exploration of complex CF gene variations.
  • Fine-mapping revealed that a specific 20-kb deletion and a missense variant are linked to an increased risk of CF-related meconium ileus and pancreatic issues, providing insights into the genetic mechanisms involved in both CF and non-CF pancreatitis.
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Article Synopsis
  • - Over 400 variants in the CFTR gene cause cystic fibrosis (CF), and while CFTR modulators can help improve lung function, they don't work for everyone and don't address all variants.
  • - The study examines the SLC26A9 gene marker (rs7512462) and its relationship to lung function in CF patients before and after treatment, finding that certain genetic variants linked to SLC26A9 lead to better lung function and response to CFTR modulators.
  • - The research suggests that targeting SLC26A9 could offer new therapeutic options not just for CF but also for individuals with other lung conditions like chronic obstructive pulmonary disease (COPD).
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Background And Objectives: Cystic fibrosis (CF) screen-positive infants with an inconclusive diagnosis (CFSPID) are infants in whom sweat testing and genetic analysis does not resolve a CF diagnosis. Lack of knowledge about the health outcome of these children who require clinical follow-up challenges effective consultation. Early predictive biomarkers to delineate the CF risk would allow a more targeted approach to these children.

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Objective: This study aimed to evaluate palivizumab (PVZ) use, trends in indications, and outcomes of respiratory illness hospitalizations (RIH) and respiratory syncytial virus hospitalizations (RSVH).

Study Design: It involves a large, Canadian prospective (2005-2017) observational multicenter study of children at high risk for RSV infection.

Results: A total of 25,003 infants (56.

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Despite the development of effective therapies, a substantial proportion of asthmatics continue to have uncontrolled symptoms, airflow limitation, and exacerbations. Transient receptor potential cation channel member A1 (TRPA1) agonists are elevated in human asthmatic airways, and in rodents, TRPA1 is involved in the induction of airway inflammation and hyperreactivity. Here, the discovery and early clinical development of GDC-0334, a highly potent, selective, and orally bioavailable TRPA1 antagonist, is described.

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Article Synopsis
  • Cystic fibrosis (CF) affects various organs, including the pancreas, which can lead to cystic fibrosis-related diabetes (CFRD), impacting survival rates if untreated.
  • Researchers built a CFRD prediction model using genetic data from a Canadian study and validated it with data from a French study, highlighting key predictors like sex and certain genetic variants.
  • The final model successfully identifies individuals at high risk for CFRD and has led to the creation of a web-based tool that helps doctors monitor and treat patients based on their specific risk levels.
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Background: Newborn screening (NBS) for cystic fibrosis (CF) not only identifies infants with a diagnosis of CF, but also those with an uncertain diagnosis of cystic fibrosis (CF), i.e. CF transmembrane conductance regulator (CFTR)-related metabolic syndrome (CRMS) or CF screen positive inconclusive diagnosis (CFSPID).

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Background: Community-acquired pneumonia (CAP) is common within pediatrics and contributes disproportionately to morbidity and mortality. Necrotizing pneumonia is a well-documented complication of CAP. It is thought to be caused by necrosis and liquefaction of consolidated lung and can result in damage to lung parenchyma, including pneumatocele development.

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Respiratory syncytial virus (RSV) may cause severe illness in cystic fibrosis (CF) children, but recommendations vary on prophylaxis. CARESS is a prospective registry of children who received palivizumab in 32 Canadian sites from 2005 to 2016. Demographic data were collected at enrollment and respiratory illness-related events recorded monthly.

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Objectives: Acute respiratory distress syndrome (ARDS) is caused by many factors including inhalation of toxicants, acute barotrauma, acid aspiration, and burns. Surfactant function is impaired in ARDS and acute airway injury resulting in high surface tension with alveolar and small airway collapse, edema, hypoxemia, and death. In this study, we explore the mechanisms whereby surfactant becomes dysfunctional in ARDS and bronchiolitis and its repair with a cyclodextrin drug that sequesters cholesterol.

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Respiratory syncytial virus (RSV) infection in cystic fibrosis (CF) infants is associated with significant morbidities. This study's objective is to evaluate the effectiveness and adverse events related to palivizumab (PVZ) in CF infants. Data on respiratory-related illness (RIH) and RSV hospitalizations (RSVH) were collected retrospectively in CF infants aged < 2 years in Alberta, Canada, from 2000 to 2017.

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Background: Airway surfactant is impaired in cystic fibrosis (CF) and associated with declines in pulmonary function. We hypothesized that surfactant dysfunction in CF is due to an excess of cholesterol with an interaction with oxidation.

Methods: Surfactant was extracted from bronchial lavage fluid from children with CF and surface tension, and lipid content, inflammatory cells and microbial flora were determined.

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Objective: The objective was to derive a simple clinical scoring instrument for assessing children with croup by telephone for use in clinical research studies.

Methods: We reviewed published literature on croup scores, surveyed experienced pediatric emergency nurses and physicians, and conducted a prospective cohort study. Score items were derived from published literature and surveys of experienced clinicians.

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Article Synopsis
  • - The study aimed to analyze infants with inconclusive cystic fibrosis diagnoses, identified through newborn screening, to understand disease manifestations and outcomes.
  • - It involved 82 infants with CFSPID and 80 with confirmed cystic fibrosis, comparing various health data including sweat tests and genetic information, revealing that some CFSPID infants eventually received a cystic fibrosis diagnosis.
  • - Results showed that CFSPID infants had lower immunoreactive trypsinogen levels and that a significant number were likely to be diagnosed with cystic fibrosis within the first three years, indicating the need for close monitoring and repeat testing.
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Lineage or cell of origin of cancers is often unknown and thus is not a consideration in therapeutic approaches. Alveolar rhabdomyosarcoma (aRMS) is an aggressive childhood cancer for which the cell of origin remains debated. We used conditional genetic mouse models of aRMS to activate the pathognomonic Pax3:Foxo1 fusion oncogene and inactivate p53 in several stages of prenatal and postnatal muscle development.

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A cell therapy strategy utilizing genetically-corrected induced pluripotent stem cells (iPSC) may be an attractive approach for genetic disorders such as muscular dystrophies. Methods for genetic engineering of iPSC that emphasize precision and minimize random integration would be beneficial. We demonstrate here an approach in the mdx mouse model of Duchenne muscular dystrophy that focuses on the use of site-specific recombinases to achieve genetic engineering.

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An infant with esophageal atresia (EA) had delayed diagnosis of proximal tracheoesophageal fistula (TEF) and severe tracheomalacia. We recommend bronchoscopy via laryngeal mask or rigid bronchoscopy to rule out associated TEF in infants diagnosed with esophageal atresia, as flexible bronchoscopy via endotracheal tube may not provide complete visualization of the trachea. We also describe a novel cervical approach to tracheopexy via neck incision for treatment of associated severe tracheomalacia in this infant.

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Background: Croup is a common childhood illness characterized by barky cough, stridor, hoarseness and respiratory distress. Children with severe croup are at risk for intubation. Nebulized epinephrine may prevent intubation.

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Congenital central hypoventilation syndrome (CCHS) is a rare disorder of autonomic dysregulation, characterized by alveolar hypoventilation especially during sleep. As a result, lifelong ventilatory assistance is necessary in these patients. Many infants and children initially require positive pressure ventilation via tracheostomy for support.

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Myf5 is a member of the muscle-specific determination genes and plays a critical role in skeletal muscle development. Whereas the expression of Myf5 during embryonic and fetal myogenesis has been extensively studied, its expression in progenitors that will ultimately give rise to adult satellite cells, the stem cells responsible for muscle repair, is still largely unexplored. To investigate this aspect, we have generated a mouse strain carrying a CreER coding sequence in the Myf5 locus.

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