Effects of TXA2 antagonists on bronchial hyperresponsiveness induced by intravenous administration of LTC4 in guinea pigs were investigated by measurement of dynamic compliance and dynamic respiratory resistance, using a formula to exclude the effects of changes in airway wall thickness. With the formula, the ratio of bronchial smooth muscle constriction by histamine can be estimated as an index of bronchial hyperresponsiveness to histamine. Administration of LTC4 induced airway wall edema. The ratio of bronchial smooth muscle constriction by histamine was enhanced by the administration of LTC4. TXA2 antagonists, ONO-NT-126 and ONO-8809, inhibited the increased ratio of bronchial smooth muscle constriction of LTC4. On the other hand, the antagonists showed no significant effects on airway wall edema by LTC4. These results suggest TXA2 may play a role in LTC4-induced bronchial hyperresponsiveness to histamine.
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Crit Rev Toxicol
January 2025
Syngenta, Bracknell, United Kingdom.
While progress has been made in recent years, there are still no suitable and accepted , or models that can be used to accurately predict whether a chemical substance has the intrinsic property to cause immune-mediated chemical respiratory allergy, typically manifested as allergic asthma or allergic rhinitis which represents a severe health hazard. Regulatory authorities have relied primarily on clinical evidence (case reports, clinical databases, worker exposure studies) to classify substances as respiratory sensitizers, but this evidence can lack a proven immunological mechanism which is necessary to identify substances which can cause life-long sensitization and clinically relevant allergic symptoms in the respiratory tract in an exposed population (such respiratory allergens may be considered as "true" sensitizers, in analogy to the definition of skin sensitization, and in contrast to respiratory irritants). In light of this, the European Center for Ecotoxicology and Toxicology of Chemicals convened a Task Force to evaluate the types of clinical methods and data sources and the implications of relying on such data for regulatory decision making from a scientific perspective.
View Article and Find Full Text PDFZhonghua Yi Xue Za Zhi
January 2025
State Key Laboratory of Respiratory Disease/Guangzhou Institute of Respiratory Health/the First Affiliated Hospital of Guangzhou Medical University, Guangzhou510120, China.
To explore the application value of surface respiratory muscle electromyography and its ratio to tidal volume in the assessment of airway hyperresponsiveness in bronchial asthma patients. A case-control study was conducted to retrospectively analyze the data of 29 asthma patients who visited the outpatient department of respiratory medicine of the First Affiliated Hospital of Guangzhou Medical University from October 2015 to May 2017 and 27 non-asthmatic subjects who were recruited as the control group.Changes in surface respiratory muscle electromyography (parasternal, EMG, diaphragmatic, EMG), and its ratio to tidal volume (EMG/VT, EMG/VT) before and after the histamine challenge test were compared between the asthma group and the control group; and their receiver operating characteristic (ROC) curves were plotted.
View Article and Find Full Text PDFLung
January 2025
Department of Pathology, The Second People's Hospital of China Three Gorges University/ Yichang Second People's Hospital, Yichang, 443000, Hubei, China.
Background: Some studies have suggested that the forced expiratory flow between 25 and 75% of vital capacity (FEF) can be used as an early marker of bronchial hyperresponsiveness (BHR) in asthma and allergic rhinitis (AR), but is highly variable. Here, we aimed to assess whether the FEF can be used to diagnose BHR in patients with asthma-like symptoms and AR.
Methods: PubMed, EMBASE, Web of Science, Wiley Online Library, Cochrane Library, SinoMed, CNKI, and Wanfang Data were searched to acquire eligible studies.
Free Radic Biol Med
January 2025
Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China. Electronic address:
J Pers Med
December 2024
Respiratory Biomedical Research Centre, University Hospital Southampton, Southampton SO16 6YD, UK.
While the phenotypic diversity of childhood wheezing is well described, the subsequent life course of such phenotypes and their adult outcomes remain poorly understood. We hypothesized that different childhood wheezing phenotypes have varying longitudinal outcomes at age 26. We sought to identify factors associated with wheezing persistence, clinical remission, and new onset in adulthood.
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