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Med (New York, N.Y.) Jan 2024Ischemic heart disease is the greatest health burden and most frequent cause of death worldwide. Myocardial ischemia/reperfusion is the pathophysiological substrate of... (Review)
Review
Ischemic heart disease is the greatest health burden and most frequent cause of death worldwide. Myocardial ischemia/reperfusion is the pathophysiological substrate of ischemic heart disease. Improvements in prevention and treatment of ischemic heart disease have reduced mortality in developed countries over the last decades, but further progress is now stagnant, and morbidity and mortality from ischemic heart disease in developing countries are increasing. Significant problems remain to be resolved and require a better pathophysiological understanding. The present review attempts to briefly summarize the state of the art in myocardial ischemia/reperfusion research, with a view on both its coronary vascular and myocardial aspects, and to define the cutting edges where further mechanistic knowledge is needed to facilitate translation to clinical practice.
Topics: Humans; Myocardial Reperfusion Injury; Myocardial Ischemia; Myocardial Reperfusion; Myocardium
PubMed: 38218174
DOI: 10.1016/j.medj.2023.12.007 -
Nature Communications Nov 2023Normothermic machine perfusion (NMP) after static cold storage is increasingly used for preservation and assessment of human donor livers prior to transplantation....
Normothermic machine perfusion (NMP) after static cold storage is increasingly used for preservation and assessment of human donor livers prior to transplantation. Biliary viability assessment during NMP reduces the risk of post-transplant biliary complications. However, understanding of molecular changes in the biliary system during NMP remains incomplete. We performed an in-depth, unbiased proteomics analysis of bile collected during sequential hypothermic machine perfusion, rewarming and NMP of 55 human donor livers. Longitudinal analysis during NMP reveals proteins reflective of cellular damage at early stages, followed by upregulation of secretory and immune response processes. Livers with bile chemistry acceptable for transplantation reveal protein patterns implicated in regenerative processes, including cellular proliferation, compared to livers with inadequate bile chemistry. These findings are reinforced by detection of regenerative gene transcripts in liver tissue before machine perfusion. Our comprehensive bile proteomics and liver transcriptomics data sets provide the potential to further evaluate molecular mechanisms during NMP and refine viability assessment criteria.
Topics: Humans; Bile; Liver Transplantation; Proteome; Living Donors; Liver; Biliary Tract; Perfusion
PubMed: 38036513
DOI: 10.1038/s41467-023-43368-y -
Transplant International : Official... 2023Organ preservation and assessment with machine perfusion (MP) has provided transplant physicians with the ability to evaluate and select grafts suitable for... (Review)
Review
Organ preservation and assessment with machine perfusion (MP) has provided transplant physicians with the ability to evaluate and select grafts suitable for transplantation. Nevertheless, the discard of organs considered too damaged still sustains the imbalance between donor organs supply and demands. Therefore, there is the pressing clinical need for strategies to repair and/or regenerate organs before transplantation, and MP is uniquely positioned to satisfy this need. The systemic administration of mesenchymal stromal cells (MSC) was shown to reduce ischemia-reperfusion injury in pre-clinical organ transplant models but could not be reproduced in clinical transplantation, largely because of inefficient cell delivery. The administration of MSC during MP is one strategy that recently gained much attention as an alternative delivery method to target MSC directly to the donor organ. However, careful reinterpretation of preliminary results reveals that this approach is equally limited by a suboptimal delivery of short-lived MSC to the target organ. In contrast, the use of MSC secretome and/or extracellular vesicles therapy during MP seems to be more efficient in harnessing MSC properties during MP. In this mini review we speculate on the future of the novel niche of organ repair and regeneration before transplantation.
Topics: Humans; Organ Preservation; Organ Transplantation; Regeneration; Perfusion; Mesenchymal Stem Cell Transplantation
PubMed: 38020754
DOI: 10.3389/ti.2023.11947 -
Cells Jul 2023Ischemia and reperfusion (IR) damage organs and contribute to many disease states. Few effective treatments exist that attenuate IR injury. The augmentation of nitric... (Review)
Review
Ischemia and reperfusion (IR) damage organs and contribute to many disease states. Few effective treatments exist that attenuate IR injury. The augmentation of nitric oxide (NO) signaling remains a promising therapeutic target for IR injury. NO binds to soluble guanylyl cyclase (sGC) to regulate vasodilation, maintain endothelial barrier integrity, and modulate inflammation through the production of cyclic-GMP in vascular smooth muscle. Pharmacologic sGC stimulators and activators have recently been developed. In preclinical studies, sGC stimulators, which augment the reduced form of sGC, and activators, which activate the oxidized non-NO binding form of sGC, increase vasodilation and decrease cardiac, cerebral, renal, pulmonary, and hepatic injury following IR. These effects may be a result of the improved regulation of perfusion and decreased oxidative injury during IR. sGC stimulators are now used clinically to treat some chronic conditions such as heart failure and pulmonary hypertension. Clinical trials of sGC activators have been terminated secondary to adverse side effects including hypotension. Additional clinical studies to investigate the effects of sGC stimulation and activation during acute conditions, such as IR, are warranted.
Topics: Humans; Soluble Guanylyl Cyclase; Hypertension, Pulmonary; Signal Transduction; Ischemia; Reperfusion
PubMed: 37508567
DOI: 10.3390/cells12141903 -
Scientific Reports Aug 2023The aim of this paper is to introduce a new mathematical model that simulates myocardial blood perfusion that accounts for multiscale and multiphysics features. Our...
The aim of this paper is to introduce a new mathematical model that simulates myocardial blood perfusion that accounts for multiscale and multiphysics features. Our model incorporates cardiac electrophysiology, active and passive mechanics, hemodynamics, valve modeling, and a multicompartment Darcy model of perfusion. We consider a fully coupled electromechanical model of the left heart that provides input for a fully coupled Navier-Stokes-Darcy Model for myocardial perfusion. The fluid dynamics problem is modeled in a left heart geometry that includes large epicardial coronaries, while the multicompartment Darcy model is set in a biventricular myocardium. Using a realistic and detailed cardiac geometry, our simulations demonstrate the biophysical fidelity of our model in describing cardiac perfusion. Specifically, we successfully validate the model reliability by comparing in-silico coronary flow rates and average myocardial blood flow with clinically established values ranges reported in relevant literature. Additionally, we investigate the impact of a regurgitant aortic valve on myocardial perfusion, and our results indicate a reduction in myocardial perfusion due to blood flow taken away by the left ventricle during diastole. To the best of our knowledge, our work represents the first instance where electromechanics, hemodynamics, and perfusion are integrated into a single computational framework.
Topics: Reproducibility of Results; Perfusion; Heart; Myocardium; Heart Ventricles
PubMed: 37648701
DOI: 10.1038/s41598-023-41312-0 -
JCI Insight Mar 2024Efficient clearance and degradation of apoptotic cardiomyocytes by macrophages (collectively termed efferocytosis) is critical for inflammation resolution and...
Efficient clearance and degradation of apoptotic cardiomyocytes by macrophages (collectively termed efferocytosis) is critical for inflammation resolution and restoration of cardiac function after myocardial ischemia/reperfusion (I/R). Here, we define secreted and transmembrane protein 1a (Sectm1a), a cardiac macrophage-enriched gene, as a modulator of macrophage efferocytosis in I/R-injured hearts. Upon myocardial I/R, Sectm1a-KO mice exhibited impaired macrophage efferocytosis, leading to massive accumulation of apoptotic cardiomyocytes, cardiac inflammation, fibrosis, and consequently, exaggerated cardiac dysfunction. By contrast, therapeutic administration of recombinant SECTM1A protein significantly enhanced macrophage efferocytosis and improved cardiac function. Mechanistically, SECTM1A could elicit autocrine effects on the activation of glucocorticoid-induced TNF receptor (GITR) at the surface of macrophages, leading to the upregulation of liver X receptor α (LXRα) and its downstream efferocytosis-related genes and lysosomal enzyme genes. Our study suggests that Sectm1a-mediated activation of the Gitr/LXRα axis could be a promising approach to enhance macrophage efferocytosis for the treatment of myocardial I/R injury.
Topics: Mice; Animals; Phagocytosis; Efferocytosis; Apoptosis; Macrophages; Inflammation; Membrane Proteins; Myocardial Reperfusion Injury; Reperfusion
PubMed: 38456501
DOI: 10.1172/jci.insight.173832 -
Acta Neurochirurgica Sep 2023Acute subdural hematoma (aSDH) is one of the main causes of high mortality and morbidity in traumatic brain injury. Prognosis is poor due to the rapid volume shift and...
INTRODUCTION
Acute subdural hematoma (aSDH) is one of the main causes of high mortality and morbidity in traumatic brain injury. Prognosis is poor due to the rapid volume shift and mass effect. Cerebral perfusion is likely affected in this condition. This study quantifies perfusion changes in aSDH using early ER polytrauma CT with perfusion imaging (CTP).
METHODS
Data of 54 patients with traumatic aSDH were retrospectively collected. Glasgow Coma scale (GCS), perfusion parameters, therapeutic decisions and imaging data including hematoma thickness, midline shift, and hematoma localization were analyzed. The cortical perfusion parameters of each hemisphere, the area anterior to the hematoma (AAH), area below the hematoma (ABH), area posterior to the hematoma (PAH), and corresponding mirrored contralateral regions were determined.
RESULTS
We found a significant difference in Tmax in affected and unaffected whole-hemisphere data (mean 4.0 s vs. 3.3 s, p < 0.05) and a significantly different mean for Tmax in ABH and for the corresponding mirrored area (mABH) (mean 3.8 s vs. 3.1 s, p < 0.05). No significant perfusion changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were found.
CONCLUSION
There was a significant elevation of time to maximum (Tmax) values in the underlying cortical area of aSDH. Possible pathophysiological explanations, the influence on immediate surgical decision-making and further therapeutic consequences have to be evaluated.
Topics: Humans; Hematoma, Subdural, Acute; Retrospective Studies; Hematoma; Perfusion; Cerebrovascular Circulation
PubMed: 37460666
DOI: 10.1007/s00701-023-05703-6 -
Free Radical Biology & Medicine Aug 2023Ischemia-reperfusion injury is a critical liver condition during hepatic transplantation, trauma, or shock. An ischemic deprivation of antioxidants and energy...
Ischemia-reperfusion injury is a critical liver condition during hepatic transplantation, trauma, or shock. An ischemic deprivation of antioxidants and energy characterizes liver injury in such cases. In the face of increased reactive oxygen production, hepatocytes are vulnerable to the reperfusion driving ROS generation and multiple cell-death mechanisms. In this study, we investigate the importance of hydrogen sulfide as part of the liver's antioxidant pool and the therapeutic potency of the hydrogen sulfide donors sodium sulfide (NaS, fast releasing) and sodium thiosulfate (STS, NaSO, slow releasing). The mitoprotection and toxicity of STS and NaS were investigated on isolated mitochondria and a liver perfusion oxidative stress model by adding text-butyl hydroperoxide and hydrogen sulfide donors. The respiratory capacity of mitochondria, hepatocellular released LDH, glutathione, and lipid-peroxide levels were quantified. In addition, wild-type and cystathionine-γ-lyase knockout mice were subjected to warm selective ischemia-reperfusion injury by clamping the main inflow for 1 h followed by reperfusion of 1 or 24 h. A subset of animals was treated with STS shortly before reperfusion. Glutathione, plasma ALT, and lipid-peroxide levels were investigated alongside mitochondrial changes in structure (electron microscopy) and function (intravital microscopy). Liver tissue necrosis quantified 24 h after reperfusion indicates the net effects of the treatment on the organ. STS refuels and protects the endogenous antioxidant pool during liver ischemia-reperfusion injury. In addition, STS-mediated ROS scavenging significantly reduced lipid peroxidation and mitochondrial damage, resulting in better molecular and histopathological preservation of the liver tissue architecture. STS prevents tissue damage in liver ischemia-reperfusion injury by increasing the liver's antioxidant pool, thereby protecting mitochondrial integrity.
Topics: Mice; Animals; Antioxidants; Hydrogen Sulfide; Reactive Oxygen Species; Chemical and Drug Induced Liver Injury, Chronic; Liver; Reperfusion Injury; Ischemia; Glutathione; Peroxides; Reperfusion; Lipids
PubMed: 37105418
DOI: 10.1016/j.freeradbiomed.2023.04.012 -
Physics in Medicine and Biology May 2024Standard models for perfusion quantification in DCE-MRI produce a bias by treating voxels as isolated systems. Spatiotemporal models can remove this bias, but it is...
Standard models for perfusion quantification in DCE-MRI produce a bias by treating voxels as isolated systems. Spatiotemporal models can remove this bias, but it is unknown whether they are fundamentally identifiable. The aim of this study is to investigate this question in silico using one-dimensional toy systems with a one-compartment blood flow model and a two-compartment perfusion model.For each of the two models, identifiability is explored theoretically and in-silico for three systems. Concentrations over space and time are simulated by forward propagation. Different levels of noise and temporal undersampling are added to investigate sensitivity to measurement error. Model parameters are fitted using a standard gradient descent algorithm, applied iteratively with a stepwise increasing time window. Model fitting is repeated with different initial values to probe uniqueness of the solution. Reconstruction accuracy is quantified for each parameter by comparison to the ground truth.Theoretical analysis shows that flows and volume fractions are only identifiable up to a constant, and that this degeneracy can be removed by proper choice of parameters. Simulations show that in all cases, the tissue concentrations can be reconstructed accurately. The one-compartment model shows accurate reconstruction of blood velocities and arterial input functions, independent of the initial values and robust to measurement error. The two-compartmental perfusion model was not fully identifiable, showing good reconstruction of arterial velocities and input functions, but multiple valid solutions for the perfusion parameters and venous velocities, and a strong sensitivity to measurement error in these parameters.These results support the use of one-compartment spatiotemporal flow models, but two-compartment perfusion models were not sufficiently identifiable. Future studies should investigate whether this degeneracy is resolved in more realistic 2D and 3D systems, by adding physically justified constraints, or by optimizing experimental parameters such as injection duration or temporal resolution.
Topics: Models, Biological; Magnetic Resonance Imaging; Perfusion; Time Factors; Humans; Image Processing, Computer-Assisted; Spatio-Temporal Analysis
PubMed: 38636525
DOI: 10.1088/1361-6560/ad4087 -
BMC Women's Health Jun 2023The aim of this retrospective study was to investigate whether oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and...
Combined oral antibiotics and intrauterine perfusion can improve in vitro fertilization and embryo transfer pregnancy outcomes in patients with chronic endometritis and repeated embryo implantation failure.
BACKGROUND
The aim of this retrospective study was to investigate whether oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) are beneficial for patients with repeated implantation failure (RIF) and chronic endometritis (CE) to improve clinical pregnancy outcomes.
METHODS
Patients with RIF and CE were diagnosed using hysteroscopy and histology together. A total of 42 patients were enrolled in the study. All patients received oral antibiotics (doxycycline combined with metronidazole) and 22 patients underwent intrauterine perfusion (gentamicin combined with dexamethasone) immediately after the end of oral antibiotic therapy. Pregnancy outcomes were evaluated during the first in vitro fertilization (IVF) and embryo transfer (ET) cycle.
RESULTS
For the first D3 ET after treatment with oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone), higher embryo implantation rate (30.95% vs. 26.67%, P = 0.0308), clinical pregnancy rate (30% vs. 50%, P < 0.001), live birth rate (33.33% vs. 45.45%, P < 0.0001). No fetal malformations or ectopic pregnancies were observed.
CONCLUSION
We report oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) as a novel treatment for CE to improve the outcomes of successful pregnancy compared with those of oral antibiotics alone.
Topics: Female; Pregnancy; Humans; Doxycycline; Metronidazole; Pregnancy Outcome; Endometritis; Retrospective Studies; Perfusion; Anti-Bacterial Agents; Embryo Transfer; Fertilization in Vitro; Gentamicins; Chronic Disease; Embryo Implantation; Dexamethasone
PubMed: 37391748
DOI: 10.1186/s12905-023-02443-8