-
Biomicrofluidics May 2024The role of the circulatory system, containing the blood and lymphatic vasculatures, within the body, has become increasingly focused on by researchers as dysfunction of... (Review)
Review
The role of the circulatory system, containing the blood and lymphatic vasculatures, within the body, has become increasingly focused on by researchers as dysfunction of either of the systems has been linked to serious complications and disease. Currently, models are unable to provide the sufficient monitoring and level of manipulation needed to characterize the fluidic dynamics of the microcirculation in blood and lymphatic vessels; thus models have been pursued as an alternative model. Microfluidic devices have the required properties to provide a physiologically relevant circulatory system model for research as well as the experimental tools to conduct more advanced research analyses of microcirculation flow. In this review paper, the physiological behavior of fluid flow and electrical communication within the endothelial cells of the systems are detailed and discussed to highlight their complexities. Cell co-culturing methods and other relevant organ-on-a-chip devices will be evaluated to demonstrate the feasibility and relevance of the microfluidic model. Microfluidic systems will be determined as a noteworthy model that can display physiologically relevant flow of the cardiovascular and lymphatic systems, which will enable researchers to investigate the systems' prevalence in diseases and identify potential therapeutics.
PubMed: 38726373
DOI: 10.1063/5.0175154 -
Heliyon Sep 2023Bisphosphonates are known to induce a severe adverse effect known as medication-related osteonecrosis of the jaw (MRONJ). Previous studies have proven the impact of...
OBJECTIVES
Bisphosphonates are known to induce a severe adverse effect known as medication-related osteonecrosis of the jaw (MRONJ). Previous studies have proven the impact of bisphosphonates on microperfusion; therefore, this study aimed to investigate alendronate-induced microcirculatory reactions in the calvarial periosteum of rats.
STUDY DESIGN
Bone chambers were implanted into 48 Lewis rats. Microhemodynamics, inflammatory parameters, functional capillary density and defect healing were examined after alendronate treatment for two and six weeks using repetitive intravital fluorescence microscopy for two weeks.
RESULTS
Microhemodynamics remained unchanged. In alendronate-treated rats, inflammation was slightly increased, functional capillary density was significantly reduced (day 10: controls 100.45 ± 5.38 cm/cm, two weeks alendronate treatment 44.77 ± 3.55 cm/cm, six weeks alendronate treatment 27.54 ± 2.23 cm/cm) and defect healing was decelerated. The changes in functional capillary density and defect healing were dose-dependent.
CONCLUSION
The bisphosphonate alendronate has a significant negative impact on periosteal microperfusion in vivo. This could be a promising target for the treatment of MRONJ.
PubMed: 37681156
DOI: 10.1016/j.heliyon.2023.e19468 -
Journal of Clinical Monitoring and... Oct 2023Acute kidney injury (AKI) is frequently seen in patients with hemorrhagic shock due to hypotension, tissue hypoxia, and inflammation despite adequate resuscitation....
Acute kidney injury (AKI) is frequently seen in patients with hemorrhagic shock due to hypotension, tissue hypoxia, and inflammation despite adequate resuscitation. There is a lack of information concerning the alteration of renal microcirculation and perfusion during shock and resuscitation. The aim of this study was to investigate the possible role of renal microcirculatory alterations on development of renal dysfunction in a pig model of non-traumatic hemorrhagic shock (HS) induced AKI.Fully instrumented female pigs were divided into the two groups as Control (n = 6) and HS (n = 11). HS was achieved by withdrawing blood until mean arterial pressure (MAP) reached around 50 mmHg. After an hour cessation period, fluid resuscitation with balanced crystalloid was started for the duration of 1 h. The systemic and renal hemodynamics, renal microcirculatory perfusion (contrast-enhanced ultrasound (CEUS)) and the sublingual microcirculation were measured.CEUS peak enhancement was significantly increased in HS during shock, early-, and late resuscitation indicating perfusion defects in the renal cortex (p < 0.05 vs. baseline, BL) despite a stable renal blood flow (RBF) and urine output. Following normalization of systemic hemodynamics, we observed persistent hypoxia (high lactate) and high red blood cell (RBC) velocity just after initiation of resuscitation resulting in further endothelial and renal damage as shown by increased plasma sialic acid (p < 0.05 vs. BL) and NGAL levels. We also showed that total vessel density (TVD) and functional capillary density (FCD) were depleted during resuscitation (p < 0.05).In this study, we showed that the correction of systemic hemodynamic variables may not be accompanied with the improvement of renal cortical perfusion, intra-renal blood volume and renal damage following fluid resuscitation. We suggest that the measurement of renal injury biomarkers, systemic and renal microcirculation can be used for guiding to the optimization of fluid therapies.
Topics: Humans; Female; Animals; Swine; Shock, Hemorrhagic; Microcirculation; Acute Kidney Injury; Kidney; Fluid Therapy; Hypoxia; Resuscitation; Hemodynamics
PubMed: 36745316
DOI: 10.1007/s10877-023-00978-7 -
Annals of Medicine and Surgery (2012) Jun 2024Kidney damage can result from various factors, leading to structural and functional changes in the kidney. Acute kidney injury (AKI) refers to a sudden decline in kidney... (Review)
Review
INTRODUCTION
Kidney damage can result from various factors, leading to structural and functional changes in the kidney. Acute kidney injury (AKI) refers to a sudden decline in kidney function, while chronic kidney disease involves a gradual deterioration lasting more than 3 months. Mechanisms of renal injury include impaired microcirculation, inflammation, and oxidative stress. Cysteinyl-leukotrienes (CysLTs) are inflammatory substances contributing to tissue damage. Montelukast, a leukotriene receptor antagonist, has shown potential renoprotective effects in experimental models of kidney injury.
METHODS
The authors conducted a scoping review using PubMed, Scopus, and Web of Science databases to identify relevant studies investigating the impact of montelukast on renal diseases. Articles published until 2022 were included and evaluated for quality. Data extraction and analysis were performed based on predetermined inclusion criteria.
RESULTS
The scoping review included 30 studies from 8 countries. Montelukast demonstrated therapeutic effects in various experimental models of nephrotoxicity and AKI induced by agents such as cisplatin, lipopolysaccharide, diclofenac, amikacin, , cyclosporine, methotrexate, cobalt-60 gamma radiation, doxorubicin, and cadmium. Studies involving human subjects with nephrotic syndrome, pyelonephritis, and other renal diseases also reported positive outcomes with montelukast treatment. Montelukast exhibited anti-inflammatory, anti-apoptotic, antioxidant, and neutrophil-inhibiting properties, leading to improved kidney function and histopathological changes.
CONCLUSIONS
Montelukast shows promise as a renoprotective medication, particularly in early-stage kidney injury. Its ability to mitigate inflammation, oxidative stress, and neutrophil infiltration contributes to its therapeutic effects. Further research is needed to explore the clinical applications and mechanisms underlying the renoprotective action of montelukast.
PubMed: 38846849
DOI: 10.1097/MS9.0000000000002085 -
Diagnostics (Basel, Switzerland) Feb 2024Thrombotic microangiopathies (TMAs) comprise a distinct group of diseases with different manifestations that can occur in both pediatric and adult patients. They can be... (Review)
Review
Thrombotic microangiopathies (TMAs) comprise a distinct group of diseases with different manifestations that can occur in both pediatric and adult patients. They can be hereditary or acquired, with subtle onset or a rapidly progressive course, and they are particularly known for their morbidity and mortality. Pregnancy is a high-risk time for the development of several types of thrombotic microangiopathies. The three major syndromes are hemolysis, elevated liver function tests, and low platelets (HELLP); hemolytic uremic syndrome (HUS); and thrombotic thrombocytopenic purpura (TTP). Because of their rarity, clinical information and therapeutic results related to these conditions are often obtained from case reports, small series, registries, and reviews. The collection of individual observations, the evolution of diagnostic laboratories that have identified autoimmune and/or genetic abnormalities using von Willebrand factor post-secretion processing or genetic-functional alterations in the regulation of alternative complement pathways in some of these TMAs, and, most importantly, the introduction of advanced treatments, have enabled the preservation of affected organs and improved survival rates. Although TMAs may show different etiopathogenesis routes, they all show the presence of pathological lesions, which are characterized by endothelial damage and the formation of thrombi rich in platelets at the microvascular level, as a common denominator, and thrombotic damage to microcirculation pathways induces "mechanical" (microangiopathic) hemolytic anemia, the consumption of platelets, and ischemic organ damage. In this review, we highlight the current knowledge about the diagnosis and management of these complications during pregnancy.
PubMed: 38396391
DOI: 10.3390/diagnostics14040352 -
Heart (British Cardiac Society) Jul 2023
Topics: Humans; Exercise Test; Angina Pectoris; Coronary Artery Disease; Coronary Angiography; Microcirculation; Coronary Vessels; Coronary Circulation
PubMed: 37012042
DOI: 10.1136/heartjnl-2023-322512 -
Translational Stroke Research Oct 2023Aneurysmal subarachnoid hemorrhage (SAH) can cause severe neurological deficits and high mortality. Early brain edema following SAH contributes to the initiation of...
Dental Pulp Stem Cell-Derived Conditioned Medium Alleviates Subarachnoid Hemorrhage-Induced Microcirculation Impairment by Promoting M2 Microglia Polarization and Reducing Astrocyte Swelling.
Aneurysmal subarachnoid hemorrhage (SAH) can cause severe neurological deficits and high mortality. Early brain edema following SAH contributes to the initiation of microcirculation impairment and may further lead to delayed ischemic neurologic deficit (DIND). This study aimed to investigate whether dental pulp stem cell conditioned medium (DPSC-CM) ameliorates SAH-induced microcirculation impairment and the underlying mechanisms. SAH was induced via intrathecal injection of fresh autologous blood in Wistar male adult rat. DPSC-CM or DPSC-CM + insulin growth factor-1 (IGF-1) antibody was randomly administered by intrathecal route 5 min after SAH induction. To evaluate the underlying mechanisms of DPSC-CM in the treatment of SAH, primary rat astrocyte and microglia co-cultures were challenged with hemolysate or SAH-patient CSF in the presence or absence of DPSC-CM. The results showed that in vivo, DPSC-CM treatment decreased the brain water content, improved microcirculation impairment and enhanced functional recovery at 24 h post-SAH. DPSC-CM treatment also alleviated the expressions of water channel protein aquaporin-4 (AQP4) and pro-inflammatory cytokines, and enhanced the expressions of anti-inflammatory factors in the cortical region. However, all the beneficial effects of DPSC-CM were abrogated after treatment with IGF-1 neutralizing antibody. The in vitro results further showed that DPSC-CM treatment reduced hemolysate/SAH-patient CSF-induced astrocyte swelling and promoted M2 microglia polarization, partially through IGF-1/AKT signaling. The data suggested that DPSC-CM significantly reduced brain edema and rescued microcirculation impairment with concomitant anti-inflammatory benefits after SAH, and may potentially be developed into a novel therapeutic strategy for SAH.
Topics: Rats; Male; Animals; Microglia; Rats, Wistar; Subarachnoid Hemorrhage; Culture Media, Conditioned; Disease Models, Animal; Brain Edema; Microcirculation; Astrocytes; Insulin-Like Growth Factor I; Dental Pulp; Anti-Inflammatory Agents; Stem Cells
PubMed: 36181630
DOI: 10.1007/s12975-022-01083-8 -
Critical Care (London, England) Mar 2024Sepsis is a life-threatening condition characterised by endothelial barrier dysfunction and impairment of normal microcirculatory function, resulting in a state of... (Review)
Review
Sepsis is a life-threatening condition characterised by endothelial barrier dysfunction and impairment of normal microcirculatory function, resulting in a state of hypoperfusion and tissue oedema. No specific pharmacological therapies are currently used to attenuate microvascular injury. Given the prominent role of endothelial breakdown and microcirculatory dysfunction in sepsis, there is a need for effective strategies to protect the endothelium. In this review we will discuss key mechanisms and putative therapeutic agents relevant to endothelial barrier function.
Topics: Humans; Microcirculation; Sepsis; Endothelium; Endothelium, Vascular
PubMed: 38521954
DOI: 10.1186/s13054-024-04875-6 -
BMC Anesthesiology Nov 2023Intraoperative arterial hypotension (IOH) leads to increased postoperative morbidity. Norepinephrine is often use to treat IOH. The question regarding the mode of... (Observational Study)
Observational Study
BACKGROUND
Intraoperative arterial hypotension (IOH) leads to increased postoperative morbidity. Norepinephrine is often use to treat IOH. The question regarding the mode of administration in either a bolus or continuous infusion remains unanswered. The aim of the present study was to describe and compare the effects on macrocirculation and microcirculation of a bolus and a continuous infusion of norepinephrine to treat IOH.
METHODS
We conducted a prospective observational study with adult patients who underwent neurosurgery. Patients with invasive arterial blood pressure and cardiac output (CO) monitoring were screened for inclusion. All patients underwent microcirculation monitoring by video-capillaroscopy, laser doppler, near-infrared spectroscopy technology, and tissular CO. In case of IOH, the patient could receive either a bolus of 10 µg or a continuous infusion of 200 µg/h of norepinephrine. Time analysis for comparison between bolus and continuous infusion were at peak of MAP. The primary outcome was MFI by videocapillaroscopy.
RESULTS
Thirty-five patients were included, with 41 boluses and 33 continuous infusion. Bolus and continuous infusion induced an maximal increase in mean arterial pressure of +30[20-45] and +23[12-34] %, respectively (P=0,07). For macrocirculatory parameters, continuous infusion was associated with a smaller decrease in CO and stroke volume (p<0.05). For microcirculatory parameters, microvascular flow index (-0,1 vs. + 0,3, p=0,03), perfusion index (-12 vs. +12%, p=0,008), total vessel density (-0,2 vs. +2,3 mm2/mm2, p=0,002), showed significant opposite variations with bolus and continuous infusion, respectively.
CONCLUSIONS
These results on macro and microcirculation enlighten the potential benefits of a continuous infusion of norepinephrine rather than a bolus to treat anaesthesia-induced hypotension.
TRIAL REGISTRATION
(NOR-PHARM: 1-17-42 Clinical Trials: NCT03454204), 05/03/2018.
Topics: Adult; Humans; Norepinephrine; Vasoconstrictor Agents; Prospective Studies; Microcirculation; Hypotension, Controlled; Anesthesia, General; Hypotension
PubMed: 37974084
DOI: 10.1186/s12871-023-02342-3