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Theranostics 2020Exosomes are small extracellular vesicles with diameters of 30-150 nm. In both physiological and pathological conditions, nearly all types of cells can release exosomes,... (Review)
Review
Exosomes are small extracellular vesicles with diameters of 30-150 nm. In both physiological and pathological conditions, nearly all types of cells can release exosomes, which play important roles in cell communication and epigenetic regulation by transporting crucial protein and genetic materials such as miRNA, mRNA, and DNA. Consequently, exosome-based disease diagnosis and therapeutic methods have been intensively investigated. However, as in any natural science field, the in-depth investigation of exosomes relies heavily on technological advances. Historically, the two main technical hindrances that have restricted the basic and applied researches of exosomes include, first, how to simplify the extraction and improve the yield of exosomes and, second, how to effectively distinguish exosomes from other extracellular vesicles, especially functional microvesicles. Over the past few decades, although a standardized exosome isolation method has still not become available, a number of techniques have been established through exploration of the biochemical and physicochemical features of exosomes. In this work, by comprehensively analyzing the progresses in exosome separation strategies, we provide a panoramic view of current exosome isolation techniques, providing perspectives toward the development of novel approaches for high-efficient exosome isolation from various types of biological matrices. In addition, from the perspective of exosome-based diagnosis and therapeutics, we emphasize the issue of quantitative exosome and microvesicle separation.
Topics: Biomarkers; Cell Line, Tumor; Chromatography, Gel; Exosomes; Humans; Immunoprecipitation; Microfluidic Analytical Techniques; Precision Medicine; Ultrafiltration
PubMed: 32206116
DOI: 10.7150/thno.41580 -
Critical Care (London, England) Oct 2016This article reports the conclusions of a consensus expert conference on the basic principles and nomenclature of renal replacement therapy (RRT) currently utilized to... (Review)
Review
This article reports the conclusions of a consensus expert conference on the basic principles and nomenclature of renal replacement therapy (RRT) currently utilized to manage acute kidney injury (AKI). This multidisciplinary consensus conference discusses common definitions, components, techniques, and operations of the machines and platforms used to deliver extracorporeal therapies, utilizing a "machine-centric" rather than a "patient-centric" approach. We provide a detailed description of the performance characteristics of membranes, filters, transmembrane transport of solutes and fluid, flows, and methods of measurement of delivered treatment, focusing on continuous renal replacement therapies (CRRT) which are utilized in the management of critically ill patients with AKI. This is a consensus report on nomenclature harmonization for principles of extracorporeal renal replacement therapies. Devices and operations are classified and defined in detail to serve as guidelines for future use of terminology in papers and research.
Topics: Acute Kidney Injury; Critical Illness; Humans; Renal Dialysis; Renal Replacement Therapy; Terminology as Topic; Ultrafiltration
PubMed: 27719682
DOI: 10.1186/s13054-016-1489-9 -
International Journal of Molecular... Sep 2020Extracellular vesicles (EVs) are membranous vesicles secreted by both prokaryotic and eukaryotic cells and play a vital role in intercellular communication. EVs are... (Review)
Review
Extracellular vesicles (EVs) are membranous vesicles secreted by both prokaryotic and eukaryotic cells and play a vital role in intercellular communication. EVs are classified into several subtypes based on their origin, physical characteristics, and biomolecular makeup. Exosomes, a subtype of EVs, are released by the fusion of multivesicular bodies (MVB) with the plasma membrane of the cell. Several methods have been described in literature to isolate exosomes from biofluids including blood, urine, milk, and cell culture media, among others. While differential ultracentrifugation (dUC) has been widely used to isolate exosomes, other techniques including ultrafiltration, precipitating agents such as poly-ethylene glycol (PEG), immunoaffinity capture, microfluidics, and size-exclusion chromatography (SEC) have emerged as credible alternatives with pros and cons associated with each. In this review, we provide a summary of commonly used exosomal isolation techniques with a focus on SEC as an ideal methodology. We evaluate the efficacy of SEC to isolate exosomes from an array of biological fluids, with a particular focus on its application to adipose tissue-derived exosomes. We argue that exosomes isolated via SEC are relatively pure and functional, and that this methodology is reproducible, scalable, inexpensive, and does not require specialized equipment or user expertise. However, it must be noted that while SEC is a good candidate method to isolate exosomes, direct comparative studies are required to support this conclusion.
Topics: Animals; Chromatography, Gel; Exosomes; Extracellular Vesicles; Humans; Ultracentrifugation; Ultrafiltration
PubMed: 32899828
DOI: 10.3390/ijms21186466 -
Archivos de Cardiologia de Mexico Apr 2022The cardiorenal syndrome is a complex entity in which a primary heart dysfunction causes kidney injury (Types 1 and 2) and vice versa (Types 3 and 4), being either acute...
The cardiorenal syndrome is a complex entity in which a primary heart dysfunction causes kidney injury (Types 1 and 2) and vice versa (Types 3 and 4), being either acute or chronic events, or maybe the result of a systemic disease that involves both organs (Type 5). Approximately 49% of heart failure cases present some grade of kidney dysfunction, significantly increasing morbidity and mortality rates. Its pathogenesis involves a variety of hemodynamic, hormonal and immunological factors that in the majority of cases produce fluid overload; the diagnosis and treatment of such constitutes the disease’s management basis. Currently, a clinical based diagnosis is insufficient and the use of biochemical markers, such as natriuretic peptides, or lung and heart ultrasound is required. These tools, along with urinary sodium levels, allow the evaluation of therapy effectiveness. The preferred initial decongestive strategy is based on a continuous infusion of a loop diuretic with a step-up dosing regimen, aiming for a minimal daily urine volume of 3 liters, with the possibility to sequentially add potassium sparing diuretics, thiazide diuretics and carbonic anhydrase inhibitors to reach the diuresis goal, leaving ultrafiltration as a last resource due to its higher rate of complications. Finally, evidence-based therapy should be given to improve quality of life, decrease mortality, and delay the deterioration of kidney and heart function over the long term.
Topics: Cardio-Renal Syndrome; Heart Failure; Hemodynamics; Humans; Quality of Life; Ultrafiltration
PubMed: 34261129
DOI: 10.24875/ACM.20000183 -
Cardiorenal Medicine 2023Fluid overload is a risk factor for increased morbidity and mortality, especially in patients with heart disease. The treatment options are limited to diuretics and... (Review)
Review
Fluid overload is a risk factor for increased morbidity and mortality, especially in patients with heart disease. The treatment options are limited to diuretics and mechanical fluid removal using ultrafiltration or renal replacement therapy. This paper provides an overview of the challenges of managing fluid overload, outlines the risks and benefits of different pharmacological options and extracorporeal techniques, and provides guidance for clinical practice.
Topics: Humans; Diuretics; Ultrafiltration; Heart Failure; Renal Replacement Therapy; Risk Factors
PubMed: 36630939
DOI: 10.1159/000529068 -
Cardiorenal Medicine 2024Heart failure remains a significant public health burden given its prevalence, morbidity, mortality as well its untoward financial consequences. (Review)
Review
BACKGROUND
Heart failure remains a significant public health burden given its prevalence, morbidity, mortality as well its untoward financial consequences.
SUMMARY
The assessment of congestion and its treatment are integral in heart failure pathophysiology and outcomes. Renal venous congestion and its suboptimal response to diuretic-based and novel pharmacological therapeutic regimens have thus positioned ultrafiltration as a promising therapeutic option for patients with acute decompensated heart failure. As a corollary, peritoneal dialysis has had success establishing itself as a relevant therapeutic option for chronic cardiorenal syndrome in patients with heart failure.
KEY MESSAGES
Herein, we will discuss the pathophysiologic basis of ultrafiltration and peritoneal dialysis in heart failure with a review of the relevant clinical trials on safety and efficacy profiles in these patient populations.
Topics: Humans; Heart Failure; Peritoneal Dialysis; Ultrafiltration; Cardio-Renal Syndrome
PubMed: 39383851
DOI: 10.1159/000541931 -
Bioanalysis Feb 2022The purpose of the study was to find methods suitable for measuring the free concentrations of testosterone and phenytoin. Sample solutions of the compounds in buffer...
The purpose of the study was to find methods suitable for measuring the free concentrations of testosterone and phenytoin. Sample solutions of the compounds in buffer and human albumin were processed using liquid-liquid extraction, microextraction and ultrafiltration and analyzed by LC-MS/MS. Liquid-liquid extraction with dibutyl phthalate provided complete extraction from buffer solutions and partial extraction from albumin samples. Spintip C18 devices provided exhaustive extraction from buffer and albumin samples. Spintip C8 devices offered complete extraction from buffer and approximately 50% recovery from albumin samples. Centrifree ultrafiltration devices showed high recovery of free concentrations from all the samples, while Amicon and Nanosep devices provided partial recovery. Spintip C8 and Centrifree devices proved useful for measuring free concentrations.
Topics: Humans; Liquid Phase Microextraction; Liquid-Liquid Extraction; Phenytoin; Testosterone; Ultrafiltration
PubMed: 35034505
DOI: 10.4155/bio-2021-0249 -
Cardiorenal Medicine 2024Some patients with cardiorenal syndrome 1 and congestion exhibit resistance to diuretics. This scenario complicates management and is associated with a worse prognosis.... (Review)
Review
BACKGROUND
Some patients with cardiorenal syndrome 1 and congestion exhibit resistance to diuretics. This scenario complicates management and is associated with a worse prognosis. In some cases, rescue treatment may be considered by starting kidney replacement therapies or ultrafiltration. This decision is complex and necessitates a profound understanding of these techniques and the pathophysiology of this syndrome. These modalities are classified into continuous, intermittent, and ultrafiltration therapies, each with its own advantages and disadvantages that are pertinent in selecting the optimal treatment.
SUMMARY
In patients with diuretic-resistant cardiorenal syndrome, extracorporeal ultrafiltration and kidney replacement therapies have the potential to relieve congestion, restore the neurohormonal system, and improve quality of life.
KEY MESSAGES
(i) In cardiorenal syndrome, the resistance to diuretics is common. (ii) Extracorporeal ultrafiltration and renal replacement therapies are rescue options that may improve the management of these patients. (iii) Better understanding of these modalities will help the development of new devices which are friendlier, safer, and more affordable for patients in these clinical settings.
Topics: Humans; Cardio-Renal Syndrome; Ultrafiltration; Renal Replacement Therapy; Diuretics; Quality of Life
PubMed: 38810607
DOI: 10.1159/000539547 -
Clinical Cardiology Dec 2021Cardiopulmonary bypass is known to raise the risk of acute kidney injury (AKI). Previous studies have identified numerous risk factors of cardiopulmonary bypass... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Cardiopulmonary bypass is known to raise the risk of acute kidney injury (AKI). Previous studies have identified numerous risk factors of cardiopulmonary bypass including the possible impact of perioperative ultrafiltration. However, the association between ultrafiltration (UF) and AKI remains conflicting. Thus, we conducted a meta-analysis to further examine the relationship between UF and AKI.
HYPOTHESIS
Ultrafiltration during cardiac surgery increases the risk of developping Acute kidney Injury.
METHODS
We searched PubMed, Web of Science, EBSCO, and SCOPUS through July 2021. The RevMan (version 5.4) software was used to calculate the pooled risk ratios (RRs) and mean differences along with their associated confidence intervals (95% CI).
RESULTS
We identified 12 studies with a total of 8005 patients. There was no statistically significant difference in the incidence of AKI between the group who underwent UF and the control group who did not (RR = 0.90, 95% CI = 0.64-1). Subgroup analysis on patients with previous renal insufficiency also yielded nonsignificant difference (RR = 0.84, 95% CI = 0.53 -1.33, p = .47). Subgroup analysis based on volume of ultrafiltrate removed (> or <2900 ml) was not significant and did not increase the AKI risk as predicted (RR = 0.82, 95% CI = 0.63 -1.07, p = .15). We also did subgroup analysis according to the type of UF and again no significant difference in AKI incidence between UF groups and controls was observed in either the conventional ultrafiltration (CUF), modified ultrafiltration (MUF), zero-balanced ultrafiltration (ZBUF), or combined MUF and CUF subgroups.
CONCLUSION
UF in cardiac surgery is not associated with increased AKI incidence and may be safely used even in baseline chronic injury patients.
Topics: Acute Kidney Injury; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Humans; Risk Factors; Ultrafiltration
PubMed: 34837387
DOI: 10.1002/clc.23750 -
Cardiorenal Medicine 2023Fluid overload is present in two-thirds of critically ill patients with acute kidney injury and is associated with morbidity, mortality, and increased healthcare... (Review)
Review
BACKGROUND
Fluid overload is present in two-thirds of critically ill patients with acute kidney injury and is associated with morbidity, mortality, and increased healthcare resource utilization. Kidney replacement therapy (KRT) is frequently used for net fluid removal (i.e., net ultrafiltration [UFNET]) in patients with severe oliguric acute kidney injury. However, ultrafiltration has considerable risks associated with it, and there is a need for newer technology to perform ultrafiltration safely and to improve outcomes.
SUMMARY
Caring for a critically ill patient with oliguric acute kidney injury and fluid overload is one of the most challenging problems. Although diuretics are the first-line treatment for management of fluid overload, diuretic resistance is common. Various clinical practice guidelines support fluid removal using ultrafiltration during KRT. Emerging evidence from observational studies in critically ill patients suggests that both slow and fast rates of net fluid removal during continuous kidney replacement therapy are associated with increased mortality compared with moderate UFNET rates. In addition, fast UFNET rates are associated with an increased risk of cardiac arrhythmias. Randomized trials are required to examine whether moderate UFNET rates are associated with a reduced risk of hemodynamic instability, organ injury, and improved outcomes in critically ill patients. There is a need for newer technology for fluid removal in patients who do not meet traditional criteria for initiation of KRT. Emerging newer and miniaturized ultrafiltration devices may address an unmet clinical need.
KEY MESSAGES
Among critically ill patients with acute kidney injury and fluid overload requiring continuous kidney replacement therapy, use of higher and slower UFNET rates compared with moderate UFNET rates might be associated with poor outcomes. Newer minimally invasive technologies may allow for safe and efficient UFNET in patients with acute kidney injury who do not meet criteria for initiation of KRT.
Topics: Humans; Ultrafiltration; Critical Illness; Renal Replacement Therapy; Acute Kidney Injury; Diuretics
PubMed: 36202071
DOI: 10.1159/000527390