Effect of hypothermia on beta 1-adrenoceptor-mediated relaxation of pig bronchus

New concepts in asthma: clinical phenotypes and pathophysiological mechanisms

Asthma is among the most common chronic inflammatory diseases worldwide. Recent evidence indicates that the pathogenesis shows a high degree of heterogeneity. Patient subsets have been identified that exhibit different cellular and molecular patterns of dysregulation. A prominent example is eosinophilic Th2-driven asthma. These unique and molecular patterns are termed endotypes. Characterization of endotypes has broad implications for therapeutic interventions. Although ∼80% of asthmatic patients respond well to standard anti-inflammatory therapies, the remaining subset particularly consisting of severe patients requires a more specialized endotype-specific approach. This interrelationship between clinical phenotypes, molecular endotypes and endotype-specific therapies is the focus of this review.

Physiological responses to hypothermia

Therapeutic hypothermia is the only treatment currently recommended for moderate or severe encephalopathy of hypoxic‒ischaemic origin in term neonates. Though the effects of hypothermia on human physiology have been explored for many decades, much of the data comes from animal or adult studies; the latter originally after accidental hypothermia, followed by application of controlled hypothermia after cardiac arrest or trauma, or during cardiopulmonary bypass. Though this work is informative, the effects of hypothermia on neonatal physiology after perinatal asphyxia must be considered in the context of a prolonged hypoxic insult that has already induced a number of significant physiological sequelae. This article reviews the effects of therapeutic hypothermia on respiratory, cardiovascular, and metabolic parameters, including glycaemic control and feeding requirements. The potential pitfalls of blood‒gas analysis and overtreatment of physiological changes in cardiovascular parameters are also discussed. Finally, the effects of hypothermia on drug metabolism are covered, focusing on how the pharmacokinetics, pharmacodynamics, and dosing requirements of drugs frequently used in neonatal intensive care may change during therapeutic hypothermia.

The Advance of Personalized and Stratified Therapies in Bronchial Asthma: Phenotypes - Endotypes - Biomarkers

Bronchial asthma (BA) is a chronic inflammatory condition with increasing incidence and prevalence worldwide. BA is currently the most prevalent chronic disease in pediatric patients. The majority of BA patients are therapeutically well controlled with guideline based anti-inflammatory therapies; however, there is also a clinically recognized proportion of patients who do not benefit from currently available medication for several reasons. This is the starting point for further investigation into the complexity of the inflammatory phenotype of BA. Recently, the heterogeneity in terms of cellular and molecular pathways underlying BA has been recognized and established. These different pathogenic mechanisms are defined as 'endotypes'. The best studied endotype so far is the association with T-helper type 2 (TH2) cell eosinophilic airway inflammation. Recently, a number of different therapeutic strategies have been clinically explored which target certain mediators of this pathway, including the interleukins IL-4, IL-5 and IL-13. It is now clear that patients with the TH2-endotype largely benefit from novel biologicals in this area. However, the challenge for diagnostics is to identify patients exhibiting this endotype, and this is the starting point for the search for new biomarkers. One biomarker that has recently been selected based on differential gene expression analysis, and which seems to be strongly associated with the TH2 endotype, is periostin. In this article we will provide a state of the art update on the definition of clinical phenotypes, pathogenetic endotypes and biomarker development for improving BA treatment.

Temperature dependence of beta 1-adrenoceptor-mediated responses examined by use of partial agonists

The inotropic and chronotropic responses of guinea pig atria, and the relaxation responses of guinea pig intestine, trachea, lung, uterus and vas deferens to catecholamines have been examined at bath temperatures of 38 degrees C and 30 degrees C. Hypothermia resulted in a supersensitivity of cardiac tissues with a decrease in isoprenaline EC50 and an increase in the maximum response to the partial agonist, salbutamol. Ileum responses to isoprenaline were potentiated at 30 degrees C but no partial agonist could be found on this tissue. Responses of the lung and vas deferens to partial agonists were not affected by temperature, while uterine responses were inhibited by hypothermia. The trachea was supersensitive to isoprenaline at 30 degrees C, however this was not due to a change in beta-adrenoceptor sensitivity but an inhibition of COMT. Partial agonist responses of trachea were similar at both temperatures. beta-Adrenoceptor supersensitivity was therefore observed only where responses are mediated primarily by beta 1-adrenoceptors and supports the concept that beta 1- but not beta 2-adrenoceptors exhibit hypothermia-induced supersensitivity.