J Neurosurg
Departments of Neurosurgery, Neurology, and Radiology, Stanford University, Stanford, California, USA.
Published: August 2005
Object: Mild hypothermia is a robust neuroprotectant, and the results of prospective clinical trials have indicated that it may improve neurological outcome in certain instances. One aspect of this protection has been associated with the prevention of blood-brain barrier (BBB) disruption. Matrix metalloproteinases (MMPs) have been implicated in BBB disruption because they can degrade the extracellular matrix. In this study the authors explored the relationship between hypothermia and MMPs and whether BBB preservation resulting from mild hypothermia therapy is due to alterations in MMP expression.
Methods: Rats were subjected to middle cerebral artery occlusion for 2 hours; the animals were maintained in a state of normothermia or mild hypothermia (33 degrees C) immediately after the onset of ischemia. The animals' brains were collected 2, 6, and 24 hours after ischemia began. Contrast-enhanced T1-weighted magnetic resonance imaging was performed at 24 hours to assess the extent of BBB disruption. Consistent with prior reports, areas of BBB disruption detected on T1-weighted images were smaller in the brains of rats maintained in a state of hypothermia (normothermia group 8.6 +/- 3% of the brain; hypothermia group 0.2 +/-0.1% of the brain; p < 0.01). Expression of both MMP-2 and MMP-9 at the transcriptional and translational levels was reduced in hypothermic brains at 6 hours and 24 hours after ischemic injury. Matrix metalloproteinase-9 was primarily localized to cells of monocytic origin but was also observed in neurons and astrocytes. Matrix metalloproteinase-2 was found in some neurons and astrocytes but not in inflammatory cells. In addition, hypothermia increased the levels of the endogenous MMP inhibitor, tissue inhibitor of metalloproteinases-2.
Conclusions: The authors conclude that mild hypothermia attenuates BBB disruption, decreases MMP expression, and suppresses MMP activity.
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http://dx.doi.org/10.3171/jns.2005.103.2.0289 | DOI Listing |
Front Neurol
January 2025
Department of Neurology, Hubei No. 3 People's Hospital of Jianghan University, Wuhan, China.
Background: Therapeutic hypothermia improves outcomes in experimental stroke models, especially after ischemia-reperfusion injury. In recent years, the safety and efficacy of hypothermia combining thrombolysis or mechanical thrombectomy have attracted widespread attention. The primary objective of the study was to evaluate the effectiveness and safety of hypothermia by combining reperfusion therapy in acute ischemic stroke patients.
View Article and Find Full Text PDFBMC Cardiovasc Disord
January 2025
Department of Cardiovascular Surgery, The Second Xiangya Hospital of Central South University, Changsha, 410011, China.
Background: As hypothermic circulatory arrest (HCA) is being more frequently induced in patients undergoing aortic arch surgery, its safety at different degrees has become a crucial area of study. The aim of this study was to assess the surgical outcomes of mild hypothermic circulatory arrest (MI-HCA) during aortic arch surgery.
Methods: Acute type A aortic dissection (ATAAD) patients who underwent total arch replacement (TAR) and frozen elephant trunk (FET) surgery between January 2014 and December 2023 were enrolled in this study.
Objective: To determine whether a transesophageal echocardiography (TEE) probe can accurately measure temperature and be used to monitor temperature changes over time without overheating in an experimental model of hypothermia and rewarming.
Methods: A 6L water bath was heated with a sous vide immersion circulator to 24C, 28C, 32C and 36C to simulate severe hypothermia, moderate hypothermia, mild hypothermia, and normothermia. A TEE probe, esophageal temperature probe, and bladder temperature probe were used to measure temperature.
Intensive Care Med Exp
January 2025
Intensive Care Unit, The First Affiliated Hospital of Guangxi Medical University, No.6 Shuangyong Road, Nanning, 530021, Guangxi, China.
Background: Sepsis-induced acute lung injury (S-ALI) significantly contributes to unfavorable clinical outcomes. Emerging evidence suggests a novel role for ferroptosis in the pathophysiology of ALI, though the precise mechanisms remain unclear. Mild hypothermia (32-34 °C) has been shown to inhibit inflammatory responses, reduce oxidative stress, and regulate metabolic processes.
View Article and Find Full Text PDFJ Feline Med Surg
January 2025
Department of Veterinary Medical Science, University of Bologna, Ozzano dell'Emilia, Italy.
Objectives: The aim of the study was to evaluate the association between triage body temperature (BT) and outcome in cats presenting to the emergency department (ED).
Methods: A retrospective observational study was conducted on cats presented to the ED. BT, clinical diagnosis and outcome were recorded.
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