Articles: function.
-
Critical care medicine · Feb 2014
Sepsis Is Associated With Altered Cerebral Microcirculation and Tissue Hypoxia in Experimental Peritonitis.
Alterations in cerebral microvascular blood flow may develop during sepsis, but the consequences of these abnormalities on tissue oxygenation and metabolism are not well defined. We studied the evolution of microvascular blood flow, brain oxygen tension (PbO2), and metabolism in a clinically relevant animal model of septic shock. ⋯ Impaired cerebral microcirculation during sepsis is associated with progressive impairment in PbO2 and brain metabolism. Development of severe hypotension was responsible for a further increase in anaerobic metabolism. These alterations may play an important role in the pathogenesis of brain dysfunction during sepsis.
-
Computed tomography (CT) is the core imaging modality for the evaluation of thoracic disorders. With the recently developed dual-energy CT (DECT) technique, the clinical utility of CT in the management of pulmonary diseases can be expanded. The most actively investigated principle of dual energy is material decomposition based on attenuation differences at different energy levels. ⋯ The second major possibility offered by DECT is virtual monochromatic imaging that represents a new option for standard chest CT in daily routine. In this review, imaging principles and clinical applications of dual-energy thoracic CT are described. Knowledge of the applications of DECT may lead to wider use of this technique in the field of respiratory disorders.
-
Am. J. Respir. Crit. Care Med. · Feb 2014
Regulation of Hypoxia-Induced Pulmonary Hypertension by Vascular Smooth Muscle HIF-1alpha.
Chronic hypoxia induces pulmonary vascular remodeling, pulmonary hypertension, and right ventricular hypertrophy. At present, little is known about mechanisms driving these responses. Hypoxia-inducible factor-1α (HIF-1α) is a master regulator of transcription in hypoxic cells, up-regulating genes involved in energy metabolism, proliferation, and extracellular matrix reorganization. Systemic loss of a single HIF-1α allele has been shown to attenuate hypoxic pulmonary hypertension, but the cells contributing to this response have not been identified. ⋯ These results indicate that HIF-1α in smooth muscle contributes to pulmonary vascular remodeling and pulmonary hypertension in chronic hypoxia. However, loss of HIF-1 function in smooth muscle does not affect hypoxic cardiac remodeling, suggesting that the cardiac hypertrophy response is not directly coupled to the increase in pulmonary artery pressure.