The brain depends on a continuous supply of oxygen to maintain its structural and functional integrity. This study measured T1 from MRI under normobaric air, normobaric oxygen, hyperbaric air, and hyperbaric oxygen (HBO) conditions as a marker of tissue pO2 since dissolved molecular oxygen acts as an endogenous contrast agent. Brain tissue T1 decreased corresponding to increased pO2 with increasing inhaled oxygen concentrations, and tissue oxygenation was estimated from the T1 changes between different inhaled oxygen levels. Tissue pO2 difference maps between different oxygen conditions showed heterogeneous pO2 changes in the brain. MRI-derived tissue pO2 was markedly lower than the arterial pO2 but was slightly higher than venous pO2. Additionally, for comparison with published extracellular tissue pO2 data obtained using oxygen electrodes and other invasive techniques, a model was used to estimate extracellular and intracellular pO2 from the MRI-derived mean tissue pO2. This required multiple assumptions, and so the effects of the assumptions and parameters used in modeling brain pO2 were evaluated. MRI-derived pO2 values were strongly dependent on assumptions about the extra- and intracellular compartments but were relatively less sensitive to variations in the relaxivity constant of oxygen and contribution from oxygen in the cerebral blood compartment. This approach may prove useful in evaluating tissue oxygenation in disease states such as stroke.
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http://dx.doi.org/10.1016/j.neuroimage.2016.03.040 | DOI Listing |
Sci Rep
December 2024
Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine- National Research Institute, PL-04-141, Warsaw, Poland.
Hypoxia, a condition of oxygen tension lower than physiological level, plays a crucial role in shaping the tumor microenvironment and modulates distinct cell populations activity. The tumor suppressor PTEN regulates angiogenesis, a process involving endothelial cells (ECs). Pathological in tumors, it is crucial for growth.
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December 2024
Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-093, Lublin, Poland.
Using Fourier Transform Infrared spectroscopy (FTIR), it is possible to show chemical composition of materials and / or profile chemical changes occurring in tissues, cells, and body fluids during onset and progression of diseases. For diagnostic application, the use of blood would be the most appropriate in biospectroscopy studies since, (i) it is easily accessible and, (ii) enables frequent analyses of biochemical changes occurring in pathological states. At present, different studies have investigated potential of serum, plasma and sputum being alternative biofluids for lung cancer detection using FTIR.
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November 2024
Infectious Diseases, Ziauddin University, Karachi, PAK.
Background Venous blood gas (VBG) investigation is a widespread option for arterial blood gas analysis because it is easier to draw and has a lower risk of complications during phlebotomy. This study aimed to establish reference intervals for the accurate analysis of VBG results as there is a lack of published data. Method Dr.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Aerospace Physiology, Air Force Medical University, Xi'an 710032, China.
Hibernating mammals experience severe hemodynamic changes over the torpor-arousal cycle, with oxygen consumption reaching peaks during the early stage of torpor to re-enter arousal. Melatonin (MT) can improve mitochondrial function and reduce oxidative stress and inflammation. However, the regulatory mechanisms of MT action on the vascular protective function of hibernators are still unclear.
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November 2024
Department of Internal Medicine, Merit Health Wesley, Hattiesburg, USA.
Metastatic sarcomatoid renal cell carcinoma (sRCC) is a significant therapeutic and diagnostic challenge due to its rarity and aggressiveness, which contribute to its poor prognosis. This case report presents the case of a 47-year-old Caucasian man with shortness of breath and right-sided abdominal pain. History revealed an extensive smoking history, a left renal mass diagnosed two months ago with inconclusive results, and an enlarged mass on computed tomography (CT) scan one week ago in an emergency department (ED) visit that showed signs consistent with metastatic disease.
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