-
Clinical Hemorheology and... 2022Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in...
BACKGROUND
Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in COVID-19 patients. Although informative, EBV does not account for cellular interactions or fibrinogen.
OBJECTIVE
Investigate whether patients with acute and recent COVID-19 have altered whole blood viscosity (WBV) when measured at both high and low shear rates using in vitro blood samples from patients.
METHODS
Cross-sectional study of 58 patients: 15 in the intensive care unit with acute COVID-19, 32 convalescent (9 < 8weeks [W] from acute infection, 23 > 8 W), and 11 controls without COVID-19. WBV was measured at high (300 s-1) and low (5 s-1) shear rates (HSR, LSR) using a scanning capillary viscometer.RESULTSAcute and convalescent patients < 8 W had mean WBV at LSR (16.0 centipoise [cP] and 15.1 cP) and HSR (5.1 cP and 4.7 cP). Mean WBV of convalescent > 8 W and control patients were 12.3 cP and 13.0 cP at LSR, and 4.1 cP and 4.2 cP at HSR. Acute and < 8 W patients had significantly higher WBV at both HSR and LSR compared to patients > 8 W (all p≤0.01). No significant differences in WBV were observed between acute and < 8 W patients, or between patients > 8 W and controls.
CONCLUSIONS
Hyperviscosity provides a possible explanation for thrombotic risk in acute and convalescent (< 8 W) patients. These findings have important implications for thromboprophylaxis.
Topics: Humans; Cross-Sectional Studies; COVID-19; Anticoagulants; Venous Thromboembolism; Blood Viscosity; Thrombosis; Thrombophilia
PubMed: 35466930
DOI: 10.3233/CH-221429 -
Transfusion Apr 2021Recent data suggests an association between blood hyperviscosity and both propensity for thrombosis and disease severity in patients with COVID-19. This raises the...
BACKGROUND
Recent data suggests an association between blood hyperviscosity and both propensity for thrombosis and disease severity in patients with COVID-19. This raises the possibility that increased viscosity may contribute to endothelial damage and multiorgan failure in COVID-19, and that therapeutic plasma exchange (TPE) to decrease viscosity may improve patient outcomes. Here we sought to share our experience using TPE in the first 6 patients treated for COVID-19-associated hyperviscosity.
STUDY DESIGN AND METHODS
Six critically ill COVID-19 patients with plasma viscosity levels ranging from 2.6 to 4.2 centipoise (cP; normal range, 1.4-1.8 cP) underwent daily TPE for 2-3 treatments.
RESULTS
TPE decreased plasma viscosity in all six patients (Pre-TPE median 3.75 cP, range 2.6-4.2 cP; Post-TPE median 1.6 cP, range 1.5-1.9 cP). TPE also decreased fibrinogen levels in all five patients for whom results were available (Pre-TPE median 739 mg/dL, range 601-1188 mg/dL; Post-TPE median 359 mg/dL, range 235-461 mg/dL); D-dimer levels in all six patients (Pre-TPE median 5921 ng/mL, range 1134-60 000 ng/mL; Post-TPE median 4893 ng/mL, range 620-7518 ng/mL); and CRP levels in five of six patients (Pre-TPE median 292 mg/L, range 136-329 mg/L; Post-TPE median 84 mg/L, range 31-211 mg/L). While the two sickest patients died, significant improvement in clinical status was observed in four of six patients shortly after TPE.
CONCLUSIONS
This series demonstrates the utility of TPE to rapidly correct increased blood viscosity in patients with COVID-19-associated hyperviscosity. Large randomized trials are needed to determine whether TPE may improve clinical outcomes for patients with COVID-19.
Topics: Adult; Aged; Blood Viscosity; COVID-19; Humans; Male; Middle Aged; Plasma Exchange; SARS-CoV-2
PubMed: 33231313
DOI: 10.1111/trf.16218 -
Frontiers in Neurology 2023The changes in blood viscosity can influence the shear stress at the vessel wall, but there is limited evidence regarding the impact on thrombogenesis and acute stroke....
BACKGROUND
The changes in blood viscosity can influence the shear stress at the vessel wall, but there is limited evidence regarding the impact on thrombogenesis and acute stroke. We aimed to investigate the effect of blood viscosity on stroke and the clinical utility of blood viscosity measurements obtained immediately upon hospital arrival.
METHODS
Patients with suspected stroke visiting the hospital within 24 h of the last known well time were enrolled. Point-of-care testing was used to obtain blood viscosity measurements before intravenous fluid infusion. Blood viscosity was measured as the reactive torque generated at three oscillatory frequencies (1, 5, and 10 rad/sec). Blood viscosity results were compared among patients with ischemic stroke, hemorrhagic stroke, and stroke mimics diagnosed as other than stroke.
RESULTS
Among 112 enrolled patients, blood viscosity measurements were accomplished within 2.4 ± 1.3 min of vessel puncture. At an oscillatory frequency of 10 rad/sec, blood viscosity differed significantly between the ischemic stroke (24.2 ± 4.9 ) and stroke mimic groups (17.8 ± 6.5 , < 0.001). This finding was consistent at different oscillatory frequencies (134.2 ± 46.3 vs. 102.4 ± 47.2 at 1 rad/sec and 39.2 ± 11.5 vs. 30.4 ± 12.4 at 5 rad/sec, Ps < 0.001), suggesting a relationship between decreases in viscosity and shear rate. The area under the receiver operating curve for differentiating cases of stroke from stroke mimic was 0.79 (95% confidence interval, 0.69-0.88).
CONCLUSION
Patients with ischemic stroke exhibit increases in whole blood viscosity, suggesting that blood viscosity measurements can aid in differentiating ischemic stroke from other diseases.
PubMed: 38107646
DOI: 10.3389/fneur.2023.1320773 -
Journal of Pediatric Gastroenterology... Jun 2020The aim of the study was to quantify the differences in viscosity of over a range of commercial food-based formulas and home-prepared blenderized feeds used for enteral...
OBJECTIVE
The aim of the study was to quantify the differences in viscosity of over a range of commercial food-based formulas and home-prepared blenderized feeds used for enteral feeding in the clinical management of gastroesophageal reflux and gastroesophageal reflux-related aspiration in children with oropharyngeal dysphagia.
METHODS
The viscosity of commercial and home blends was measured using digital rotational viscometer and International Dysphagia Diet Standardization Initiative Syringe Flow Test. Additional testing was performed to determine the impact of added cereal, water flushes, and freezing/thawing on formula viscosity.
RESULTS
There were significant variations in viscosity between commercial blends with values ranging from extremely to mildly thick by Syringe Flow Test. The highest centipoise (cP) value was 13,847 and the lowest 330 and 438 cP. Dilution of 240 mL of commercial blend with 30, 60, and 90 mL of water resulted in a decrease in viscosity of 31%, 62%, and 85%, respectively. Exposure to 1 freeze/thaw cycle decreased viscosity by as much as 59% to 80% depending on the blend. Thickening conventional pediatric formulas with rice or oatmeal did not achieve consistency equivalent to most blenderized feeds.
CONCLUSIONS
Commercial food-based formulas and home prepared blends vary greatly in viscosity, ranging from thin to extremely thick liquids, with the majority achieving viscosity greater than thickened formula. Viscosity is reduced by addition of free water and with freezing and thawing. These data can inform the clinical choice of feeding regimen depending on the goals of nutritional therapy.
Topics: Child; Deglutition Disorders; Diet; Enteral Nutrition; Food, Formulated; Humans; Viscosity
PubMed: 32443040
DOI: 10.1097/MPG.0000000000002657 -
AIMS Microbiology 2022This study evaluated the ability of two strains of bacterial starter cultures, AP (AP) and AG (AG), to produce exopolysaccharides (EPSs). First, the physicochemical...
This study evaluated the ability of two strains of bacterial starter cultures, AP (AP) and AG (AG), to produce exopolysaccharides (EPSs). First, the physicochemical properties of the fermented milk produced by AP and AG were assessed, including physical qualities like viscosity and syneresis and chemical qualities, such as pH, acidity, protein, lactose, fat content, and total solid. Then, AP and AG's ability to produce EPS was measured. Additionally, the EPS' microstructure was observed using a scanning electron microscope, and its chemical structure was assessed using Fourier transform-infrared (FT-IR) spectroscopy. Also, AP and AG's ability to produce EPS was tracked at the molecular level by studying the glycosyltransferase () gene. Statistical analysis showed that the milk fermented using AP and AG had similar physicochemical qualities (P > 0.05) but significantly different physical qualities (P < 0.05). Additionally, the milk fermented with AP had lower viscosity (1137.33 ± 34.31 centiPoise) than AG (1221.50 ± 20.66 centiPoise). In addition, the milk fermented using AP had higher syneresis (19.42%) than AG (17.83%). The higher viscosity and lower syneresis in the milk fermented using AG were associated with AG's ability to produce more EPS (1409 mg/L) than AP (1204 mg/L). In addition, according to the FT-IR analysis, the AP- and AG-synthesized EPS contained absorption bands at 3323, 2980, 2901, 1642, 1084, 1043, and 873 cm. The absorption band at 1642 and 2980 cm corresponds to carbonyl and methylene groups, respectively. Absorption band 873 cm is characteristic of the α-glycosidic bond of α-glucan in EPS. Moreover, the absorption bands on the wavelength region corresponding to the functional groups in the AP- and AG-produced EPS were similar to those in commercially available EPS. Lastly, , contributing to EPS synthesis, was found in the genomes of AP and AG, suggesting the role of glycosyltransferase in the EPS synthesis by both strains.
PubMed: 35974991
DOI: 10.3934/microbiol.2022012 -
MAbs 2021Human/humanized IgG4 antibodies have reduced effector function relative to IgG1 antibodies, which is desirable for certain therapeutic purposes. However, the...
Differences in human IgG1 and IgG4 S228P monoclonal antibodies viscosity and self-interactions: Experimental assessment and computational predictions of domain interactions.
Human/humanized IgG4 antibodies have reduced effector function relative to IgG1 antibodies, which is desirable for certain therapeutic purposes. However, the developability and biophysical properties for IgG4 antibodies are not well understood. This work focuses on the head-to-head comparison of key biophysical properties, such as self-interaction and viscosity, for 14 human/humanized, and chimeric IgG1 and IgG4 S228P monoclonal antibody pairs that contain the identical variable regions. Experimental measurements showed that the IgG4 S228P antibodies have similar or higher self-interaction and viscosity than that of IgG1 antibodies in 20 mM sodium acetate, pH 5.5. We report sequence and structural drivers for the increased viscosity and self-interaction detected in IgG4 S228P antibodies through a combination of experimental data and computational models. Further, we applied and extended a previously established computational model for IgG1 antibodies to predict the self-interaction and viscosity behavior for each antibody pair, providing insight into the structural characteristics and differences of these two isotypes. Interestingly, we observed that the IgG4 S228P swapped variants, where the CH3 domain was swapped for that of an IgG1, showed reduced self-interaction behavior. These domain swapped IgG4 S228P molecules also showed reduced viscosity from experiment and coarse-grained simulations. We also observed that experimental diffusion interaction parameter (kD) values have a high correlation with computational diffusivity prediction for both IgG1 and IgG4 S228P isotypes.Abbreviations: , constant region Hamaker constant; , variable region Hamaker constant; CDRs, Complementarity-determining regions; CG, Coarse-grained model; CH1, Constant heavy chain 1; CH2 Constant heavy chain 2; CH3 Constant heavy chain 3; chgCH3 Effective charge on the CH3 region; CL Constant light chain; cP, Centipoise; DLS, Dynamic light scattering; Fab, Fragment antigen-binding; Fc, Fragment crystallizable; Fv, Variable domaing; (r) Radial distribution function; H1 CDR1 of Heavy Chain; H2 CDR2 of Heavy Chain; H3 CDR3 of Heavy Chain; HVI, High viscosity index; IgG1 human immunoglobulin of IgG1 subclass; IgG4 human immunoglobulin of IgG4 subclass; kD, Diffusion interaction parameter; L1 CDR1 of Light Chain; L2 CDR2 of Light Chain; L3 CDR3 of Light Chain; mAb, Monoclonal antibody; MD, Molecular dynamics; PPI Protein-protein interactions; SCM, Spatial charge map; UP-SEC, Ultra-high-performance size-exclusion chromatography; VH, Variable domain of Heavy Chain; VL, Variable domain of Light Chain.
Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Complementarity Determining Regions; Humans; Immunoglobulin G; Viscosity
PubMed: 34747330
DOI: 10.1080/19420862.2021.1991256 -
Journal of Intensive Care May 2023Increased estimated whole blood viscosity (eWBV) predicts higher mortality in patients hospitalized for coronavirus disease 2019 (COVID-19). This study assesses whether...
BACKGROUND
Increased estimated whole blood viscosity (eWBV) predicts higher mortality in patients hospitalized for coronavirus disease 2019 (COVID-19). This study assesses whether eWBV is an early predictor of non-fatal outcomes among patients hospitalized for acute COVID-19 infection.
METHODS
This retrospective cohort study included 9278 hospitalized COVID-19 patients diagnosed within 48 h of admission between February 27, 2020 to November 20, 2021 within the Mount Sinai Health System in New York City. Patients with missing values for major covariates, discharge information, and those who failed to meet the criteria for the non-Newtonian blood model were excluded. 5621 participants were included in the main analysis. Additional analyses were performed separately for 4352 participants who had measurements of white blood cell count, C-reactive protein and D-dimer. Participants were divided into quartiles based on estimated high-shear blood viscosity (eHSBV) and estimated low-shear blood viscosity (eLSBV). Blood viscosity was calculated using the Walburn-Schneck model. The primary outcome was evaluated as an ordinal scale indicating the number of days free of respiratory organ support through day 21, and those who died in-hospital were assigned a value of -1. Multivariate cumulative logistic regression was conducted to evaluate the association between quartiles of eWBV and events.
RESULTS
Among 5621 participants, 3459 (61.5%) were male with mean age of 63.2 (SD 17.1) years. The linear modeling yielded an adjusted odds ratio (aOR) of 0.68 (95% CI 0.59-0.79, p value < 0.001) per 1 centipoise increase in eHSBV.
CONCLUSIONS
Among hospitalized patients with COVID-19, elevated eHSBV and eLSBV at presentation were associated with an increased need for respiratory organ support at 21 days. These findings are highly relevant, as they demonstrate the utility of eWBV in identifying hospitalized patients with acute COVID-19 infection at increased risk for non-fatal outcomes in early stages of the disease.
PubMed: 37131249
DOI: 10.1186/s40560-023-00665-4 -
Journal of the American College of... Jul 2022Coronavirus disease-2019 (COVID-19) is characterized by a dysfunctional immune response and abnormal blood rheology that contribute to endothelial dysfunction and...
BACKGROUND
Coronavirus disease-2019 (COVID-19) is characterized by a dysfunctional immune response and abnormal blood rheology that contribute to endothelial dysfunction and thrombotic complications. Whole blood viscosity (WBV) is a clinically validated measure of blood rheology and an established predictor of cardiovascular risk. We hypothesize that increased WBV is associated with mortality among patients hospitalized with COVID-19.
OBJECTIVES
This study sought to determine the association between estimated BV (eBV) and mortality among hospitalized COVID-19 patients.
METHODS
The study population included 5,621 hospitalized COVID-19 patients at the Mount Sinai Health System from February 27, 2020, to November 27, 2021. eBV was calculated using the Walburn-Schneck model. Multivariate Cox proportional hazards models were used to evaluate the association between eBV and mortality. Considered covariates included age, sex, race, cardiovascular and metabolic comorbidities, in-house pharmacotherapy, and baseline inflammatory biomarkers.
RESULTS
Estimated high-shear BV (eHSBV) and estimated low-shear BV were associated with increased in-hospital mortality. One-centipoise increases in eHSBV and estimated low-shear BV were associated with a 36.0% and 7.0% increase in death, respectively (P < 0.001). Compared with participants in the lowest quartile of eHSBV, those in the highest quartile of eHSBV had higher mortality (adjusted HR: 1.53; 95% CI: 1.27-1.84). The association was consistent among multiple subgroups, notably among patients without any comorbidities (adjusted HR: 1.69; 95% CI: 1.28-2.22).
CONCLUSIONS
Among hospitalized COVID-19 patients, increased eBV is significantly associated with higher mortality. This suggests that eBV can prognosticate patient outcomes in earlier stages of COVID-19, and that future therapeutics aimed at reducing WBV should be evaluated.
Topics: Blood Viscosity; COVID-19; Comorbidity; Hospital Mortality; Hospitalization; Humans; Retrospective Studies; Risk Factors
PubMed: 35863848
DOI: 10.1016/j.jacc.2022.04.060 -
Science Advances Oct 2021Centrifugal pumps are essential mechanical components for liquid delivery in many biomedical systems whose miniaturization can promote innovative disease treatment...
Centrifugal pumps are essential mechanical components for liquid delivery in many biomedical systems whose miniaturization can promote innovative disease treatment approaches. However, centrifugal pumps are predominately constructed by rigid and bulky components. Here, we combine the soft materials and flexible electronics to achieve soft magnetic levitation micropumps (SMLMs) that are only 1.9 to 12.8 grams in weight. The SMLMs that rotate at a rotation speed of 1000 revolutions per min to pump liquids with various viscosities ranging from 1 to 6 centipoise can be used in assisting dialysis, blood circulation, and skin temperature control because of excellent biocompatibility with no organ damage. The development of SMLMs not only demonstrates the possibility to replace rigid rotating structures with soft materials for handling large volumes of fluids but also indicates the potential for fully flexible artificial organs that may revolutionize health care and improve the well-being of patients.
PubMed: 34705505
DOI: 10.1126/sciadv.abi7203 -
ACS Omega Nov 2021Any improvement in drilling technology is critical for developing the oil and gas industry. The success of drilling operations largely depends on drilling fluid...
Any improvement in drilling technology is critical for developing the oil and gas industry. The success of drilling operations largely depends on drilling fluid characteristics. Drilling fluids require enough viscosity to suspend the particles and transport them to the surface and enough capability to control the fluid loss into the formation. Rheology and filtration characteristics of drilling fluids are crucial factors to consider while ensuring the effectiveness of a drilling operation. Graphene oxide (GO), xanthan gum (XG), and low-viscosity carboxymethyl cellulose (CMC LV) are being utilized in this research to produce high-performance, low-solid water-based drilling fluids (WDFs). Rheological and filtration behaviors of GO/XG/CMC LV-WDF were investigated as a function of GO, XG, and CMC LV at low concentrations (0.0-0.3% w/w) and atmospheric conditions. According to the findings, GO improved the rheological and filtration capabilities of the WDF. By adding 0.15 wt % GO, shear stress could be doubled, especially at a high shear rate of 1022 s. The plastic viscosity of the fluid could be expanded from 6 to 13 centipoise, and a fluid loss of 8.7 mL over 30 min was observed during the API fluid test, which would be lower than the suggested fluid loss value (15.0 mL) for water-based mud. At the same concentration of XG and CMC LV, XG had a more significant influence on rheological characteristics in the presence of GO. Adding 0.3 wt % XG could increase fluid shear stress from 20.21 to 30.21 Pa at a high shear rate of 1022 s. In contrast, CMC LV had more impact on filtration properties, acting as a filtration control agent by decreasing the API fluid loss of fluid from 21.4 to 14.2 mL over 30 min. The addition of XG and CMC LV to the GO solution may influence the microstructure of the filter cake, resulting in a tree-root morphology. Indeed, in the GO/CMC LV solution, the individual platelets may bind together, form a jellyfish shape, and block the micropores. The incorporation of CMC LV helped develop compact filter cakes, resulting in excellent filtration. Five rheological models were employed to match the fluid parameters quantitatively. The Herschel-Bulkley model outperformed the other models in simulating fluid rheological behavior. The findings of this study can be utilize to provide low-cost, stable, and environmentally compatible additives for drilling low-pressure, depleted, and fractured oil and gas reservoirs.
PubMed: 34778663
DOI: 10.1021/acsomega.1c04398