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Cells Mar 2021Ischemic nephropathy reflects progressive loss of kidney function due to large vessel atherosclerotic occlusive disease. Recent studies indicate that this process is... (Review)
Review
Ischemic nephropathy reflects progressive loss of kidney function due to large vessel atherosclerotic occlusive disease. Recent studies indicate that this process is characterized by microvascular rarefaction, increased tissue hypoxia and activation of inflammatory processes of tissue injury. This review summarizes the rationale and application of functional MR imaging to evaluate tissue oxygenation in human subjects that defines the limits of renal adaptation to reduction in blood flow, development of increasingly severe tissue hypoxia and recruitment of inflammatory injury pathways in ischemic nephropathy. Human mesenchymal stromal/stem cells (MSC) are capable of modifying angiogenic pathways and immune responses, but the potency of these effects vary between individuals and various clinical characteristics including age and chronic kidney disease and levels of hypoxia. We summarize recently completed first-in-human studies applying intrarenal infusion of autologous adipose-derived MSC in human subjects with ischemic nephropathy that demonstrate a rise in blood flow and reduction in tissue hypoxia consistent with partial repair of microvascular injury, even without restoring main renal arterial blood flow. Inflammatory biomarkers in the renal vein of post-stenotic kidneys fell after MSC infusion. These changes were associated with modest but significant dose-related increments in kidney function. These data provide support a role for autologous MSC in repair of microvascular injury associated with tissue hypoxia.
Topics: Animals; Humans; Hypoxia; Ischemia; Kidney; Kidney Diseases; Mesenchymal Stem Cell Transplantation; Microvessels
PubMed: 33807289
DOI: 10.3390/cells10040765 -
Anaesthesia Dec 2011Apnoea due to airway obstruction is an ever present concern in anaesthesia and critical care practice and results in rapid development of hypoxaemia that is not always... (Review)
Review
Apnoea due to airway obstruction is an ever present concern in anaesthesia and critical care practice and results in rapid development of hypoxaemia that is not always remediable by manual bag-mask ventilation. As it is often difficult or impossible to study experimentally (although some historical animal data exist), it is useful to model the kinetics of hypoxaemia following airway obstruction. Despite being a complex event, the consequences of airway obstruction can be predicted with reasonable fidelity using mathematical and computer modelling. Over the last 15 years, a number of high fidelity mathematical and computer models have been developed, that have thrown light on this important event.
Topics: Airway Management; Airway Obstruction; Apnea; Humans; Hypoxia; Intubation, Intratracheal; Models, Biological; Respiration, Artificial
PubMed: 22074074
DOI: 10.1111/j.1365-2044.2011.06929.x -
International Journal of Medical... 2023Severe hypoxia can induce a range of systemic disorders; however, surprising resilience can be obtained through sublethal adaptation to hypoxia, a process termed as... (Review)
Review
Severe hypoxia can induce a range of systemic disorders; however, surprising resilience can be obtained through sublethal adaptation to hypoxia, a process termed as hypoxic conditioning. A particular form of this strategy, known as intermittent hypoxia conditioning hormesis, alternates exposure to hypoxic and normoxic conditions, facilitating adaptation to reduced oxygen availability. This technique, originally employed in sports and high-altitude medicine, has shown promise in multiple pathologies when applied with calibrated mild to moderate hypoxia and appropriate hypoxic cycles. Recent studies have extensively investigated the protective role of intermittent hypoxia conditioning and its underlying mechanisms using animal models, demonstrating its potential in organ protection. This involves a range of processes such as reduction of oxidative stress, inflammation, and apoptosis, along with enhancement of hypoxic gene expression, among others. Given that intermittent hypoxia conditioning fosters beneficial physiological responses across multiple organs and systems, this review presents a comprehensive analysis of existing studies on intermittent hypoxia and its potential advantages in various organs. It aims to draw attention to the possibility of clinically applying intermittent hypoxia conditioning as a multi-organ protective strategy. This review comprehensively discusses the protective effects of intermittent hypoxia across multiple systems, outlines potential procedures for implementing intermittent hypoxia, and provides a brief overview of the potential protective mechanisms of intermittent hypoxia.
Topics: Animals; Hypoxia; Oxygen; Oxidative Stress
PubMed: 37859700
DOI: 10.7150/ijms.86622 -
British Heart Journal Jan 1993
Topics: Cell Hypoxia; Coronary Vessels; Heart; Humans; Hypoxia; Lung; Vasoconstriction
PubMed: 8457390
DOI: 10.1136/hrt.69.1.3 -
Progress in Neurobiology Oct 2017Sublethal hypoxic or ischemic events can improve the tolerance of tissues, organs, and even organisms from subsequent lethal injury caused by hypoxia or ischemia. This... (Review)
Review
Sublethal hypoxic or ischemic events can improve the tolerance of tissues, organs, and even organisms from subsequent lethal injury caused by hypoxia or ischemia. This phenomenon has been termed hypoxic or ischemic preconditioning (HPC or IPC) and is well established in the heart and the brain. This review aims to discuss HPC and IPC with respect to their historical development and advancements in our understanding of the neurochemical basis for their neuroprotective role. Through decades of collaborative research and studies of HPC and IPC in other organ systems, our understanding of HPC and IPC-induced neuroprotection has expanded to include: early- (phosphorylation targets, transporter regulation, interfering RNA) and late- (regulation of genes like EPO, VEGF, and iNOS) phase changes, regulators of programmed cell death, members of metabolic pathways, receptor modulators, and many other novel targets. The rapid acceleration in our understanding of HPC and IPC will help facilitate transition into the clinical setting.
Topics: Animals; Humans; Hypoxia; Ischemia; Ischemic Preconditioning; Neuroprotection
PubMed: 28110083
DOI: 10.1016/j.pneurobio.2017.01.001 -
Anesthesiology Feb 2011
Topics: Acute Kidney Injury; Animals; Hypoxia; Inflammation; Mice
PubMed: 21239967
DOI: 10.1097/ALN.0b013e3182070c66 -
Seminars in Fetal & Neonatal Medicine Apr 2020The premature infant is to some extent protected from hypoxia, however defense against hyperoxia is poorly developed. The optimal assessment of oxygenation is to measure... (Review)
Review
The premature infant is to some extent protected from hypoxia, however defense against hyperoxia is poorly developed. The optimal assessment of oxygenation is to measure oxygen delivery and extraction. At the bedside PaO and SpO are approximations of oxygenation at the tissue level. After birth asphyxia it is crucial to know whether or not to give oxygen supplementation, when, how much, and for how long. Oxygen saturation targets in the delivery room have been studied, but the optimal targets might still be unknown because factors like gender and delayed cord clamping influence saturation levels. However, SpO > 80% at 5 min of age is associated with favorable long term outcome in preterm babies. Immature infants most often need oxygen supplementation beyond the delivery room. Predefined saturation levels, and narrow alarm limits together with the total oxygen exposure may impact on development of oxygen related diseases like ROP and BPD. Hyperoxia is a strong trigger for genetic and epigenetic changes, contributing to the development of these conditions and perhaps lifelong changes.
Topics: Humans; Hyperoxia; Hypoxia; Infant; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Oximetry; Oxygen; Oxygen Inhalation Therapy
PubMed: 32037265
DOI: 10.1016/j.siny.2020.101078 -
Scientific Reports Oct 2022Osteosarcoma is a primary malignant tumor that often metastasizes in orthopedic diseases. Although multi-drug chemotherapy and surgical treatment have significantly...
Osteosarcoma is a primary malignant tumor that often metastasizes in orthopedic diseases. Although multi-drug chemotherapy and surgical treatment have significantly improved the survival and prognosis of patients with osteosarcoma, the survival rate is still very low due to frequent metastases in patients with osteosarcoma. In-depth exploration of the relationship between various influencing factors of osteosarcoma is very important for screening promising therapeutic targets. This study used multivariate COX regression analysis to select the hypoxia genes SLC2A1 and FBP1 in patients with osteosarcoma, and used the expression of these two genes to divide the patients with osteosarcoma into high-risk and low-risk groups. Then, we first constructed a prognostic model based on the patient's risk value and compared the survival difference between the high expression group and the low expression group. Second, in the high expression group and the low expression group, compare the differences in tumor invasion and inflammatory gene expression between the two groups of immune cells. Finally, the ferroptosis-related genes with differences between the high expression group and the low expression group were screened, and the correlation between these genes was analyzed. In the high-risk group, immune cells with higher tumor invasiveness, macrophages M0 and immune cells with lower invasiveness included: mast cell resting, regulatory T cells (Tregs) and monocytes. Finally, among genes related to ferroptosis, we found AKR1C2, AKR1C1 and ALOX15 that may be related to hypoxia. These ferroptosis-related genes were discovered for the first time in osteosarcoma. Among them, the hypoxia gene FBP1 is positively correlated with the ferroptosis genes AKR1C1 and ALOX15, and the hypoxia gene SLC2A1 is negatively correlated with the ferroptosis genes AKR1C2, AKR1C1 and ALOX15. This study constructed a prognostic model based on hypoxia-related genes SLC2A1 and FBP1 in patients with osteosarcoma, and explored their correlation with immune cells, inflammatory markers and ferroptosis-related genes. This indicates that SLC2A1 and FBP1 are promising targets for osteosarcoma research.
Topics: Female; Humans; Bone Neoplasms; Osteosarcoma; Prognosis; Neoplasm Invasiveness; Hypoxia; Fetal Hypoxia
PubMed: 36316355
DOI: 10.1038/s41598-022-17622-0 -
Journal of Applied Physiology... Apr 2014
Topics: Acclimatization; Altitude; Animals; Humans; Hypoxia; Hypoxia-Inducible Factor 1; Oxygen; Signal Transduction; Translational Research, Biomedical
PubMed: 24557798
DOI: 10.1152/japplphysiol.00145.2014 -
Biology of Reproduction Mar 2022Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to... (Review)
Review
Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular, and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.
Topics: Altitude; Altitude Sickness; Humans; Hypoxia; Male; Oxygen; Prostate; Reproduction
PubMed: 34725677
DOI: 10.1093/biolre/ioab205