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Physical Biology Jun 2022Polymers are important components of the complex fluid environment for microorganisms. The mechanical effects on bacterial motile behavior due to the viscous or...
Polymers are important components of the complex fluid environment for microorganisms. The mechanical effects on bacterial motile behavior due to the viscous or viscoelastic properties of polymers were extensively studied, whereas possible chemical effects on bacterial motility through bacterial chemoreception of the polymers were unclear. Here we studied the chemotactic response ofto polymeric solutions by combining the bead assay and FRET measurements. We found that the wild-typestrain exhibited an attractant response to widely used polymers such as Ficoll 400, polyethylene glycol (PEG) 20000 and polyvinyl pyrrolidone (PVP) 360000, and the response amplitude from chemoreception was much larger than that from the load-dependence of motor switching due to viscosity change. The chemotactic response depended on the type of receptors and the chain length of the polymers. Our findings here provided important new ingredients for further studies of bacterial motile behavior in complex fluids.
Topics: Polymers; Povidone; Viscosity
PubMed: 35545074
DOI: 10.1088/1478-3975/ac6eb1 -
Medizinische Klinik, Intensivmedizin... Nov 2021Fluid balance is crucial in critically ill patients because mechanisms to counteract fluid dysbalances are limited. Therefore, an extremely important task of ICU staff... (Review)
Review
Fluid balance is crucial in critically ill patients because mechanisms to counteract fluid dysbalances are limited. Therefore, an extremely important task of ICU staff is to assess and maintain fluid status. Fluid overload has been shown to have deleterious consequences for patients. Infusion fluids may be divided into colloid and crystalloid solutions. Within the crystalloids, balanced solutions have been shown to be superior over 0.9% saline with respect to acidosis, acute kidney injury, and mortality. The most widespread used colloid is hydroyethyl starch (HES). Compared to crystalloids, HES has a much greater volume effect. Despite this advantage, precautions must be undertaken with the use of HES. Side effects such as anaphylactic reactions and acute kidney injury are not uncommon; thus, critically ill patients and those at risk of kidney dysfunction should only receive HES preparations after careful consideration.
Topics: Colloids; Critical Illness; Crystalloid Solutions; Fluid Therapy; Homeostasis; Humans; Hydroxyethyl Starch Derivatives; Isotonic Solutions; Plasma Substitutes; Rehydration Solutions; Resuscitation
PubMed: 34599373
DOI: 10.1007/s00063-021-00871-8 -
Neuroscience Bulletin Jan 2020
Review
Topics: Aging; Alzheimer Disease; Animals; Humans; Plasma Exchange; Plasma Substitutes
PubMed: 31111428
DOI: 10.1007/s12264-019-00394-5 -
ASAIO Journal (American Society For... Jul 2023Ex vivo lung perfusion (EVLP) is a method of organ preservation to expand the donor pool by allowing organ assessment and repair. Perfusion solution composition is...
Ex vivo lung perfusion (EVLP) is a method of organ preservation to expand the donor pool by allowing organ assessment and repair. Perfusion solution composition is crucial to maintaining and improving organ function during EVLP. EVLP compared perfusates supplemented with either polymeric human serum albumin (PolyHSA) or standard human serum albumin (HSA). Rat heart-lung blocks underwent normothermic EVLP (37°C) for 120 minutes using perfusate with 4% HSA or 4% PolyHSA synthesized at a 50:1 or 60:1 molar ratio of glutaraldehyde to PolyHSA. Oxygen delivery, lung compliance, pulmonary vascular resistance (PVR), wet-to-dry ratio, and lung weight were measured. Perfusion solution type (HSA or PolyHSA) significantly impacted end-organ metrics. Oxygen delivery, lung compliance, and PVR were comparable among groups ( P > 0.05). Wet-to-dry ratio increased in the HSA group compared to the PolyHSA groups (both P < 0.05) suggesting edema formation. Wet-to-dry ratio was most favorable in the 60:1 PolyHSA-treated lungs compared to HSA ( P < 0.05). Compared to using HSA, PolyHSA significantly lessened lung edema. Our data confirm that the physical properties of perfusate plasma substitutes significantly impact oncotic pressure and the development of tissue injury and edema. Our findings demonstrate the importance of perfusion solutions and PolyHSA is an excellent candidate macromolecule to limit pulmonary edema. http://links.lww.com/ASAIO/A980.
Topics: Humans; Animals; Rats; Lung Transplantation; Lung; Perfusion; Serum Albumin, Human; Organ Preservation; Oxygen
PubMed: 36976617
DOI: 10.1097/MAT.0000000000001918 -
Critical Care (London, England) May 2020Burn injury is associated with a long-standing inflammatory reaction. The use of albumin solutions for plasma volume support is controversial because of concerns of...
BACKGROUND
Burn injury is associated with a long-standing inflammatory reaction. The use of albumin solutions for plasma volume support is controversial because of concerns of increased capillary leakage, which could aggravate the commonly seen interstitial oedema.
METHODS
In the present open controlled clinical trial, an intravenous infusion of 20% albumin at 3 mL/kg was given over 30 min to 15 burn patients and 15 healthy volunteers. Blood samples and urine were collected for 5 h. Plasma dilution, plasma albumin and colloid osmotic pressure were compared. Mass balance calculations were used to estimate plasma volume expansion and capillary leakage of fluid and albumin.
RESULTS
The patients were studied between 4 and 14 (median, 7) days after the burn injury, which spread over 7-48% (median, 15%) of the total body surface area. The albumin solution expanded the plasma volume by almost 15%, equivalent to twice the infused volume, in both groups. The urinary excretion exceeded the infused volume by a factor of 2.5. Capillary leakage of albumin occurred at a rate of 3.4 ± 1.5 g/h in burn patients and 3.7 ± 1.6 g/h in the volunteers (P = 0.61), which corresponded to 2.4 ± 1.0% and 2.5 ± 1.2% per hour of the intravascular pool (P = 0.85). The median half-life of the plasma volume expansion was 5.9 (25th-75th percentiles 2.7-11.7) h in the burn patients and 6.9 (3.4-8.5) h in the volunteers (P = 0.56).
CONCLUSIONS
Albumin 20% was an effective volume expander in patients at 1 week post-burn. No relevant differences were found between burn patients and healthy volunteers.
TRIAL REGISTRATION
EudraCT 2016-000996-26 on May 31, 2016.
Topics: Adult; Burns; Capillary Leak Syndrome; Female; Humans; Male; Plasma Substitutes; Plasma Volume; Serum Albumin, Human
PubMed: 32366324
DOI: 10.1186/s13054-020-02855-0 -
The Annals of Pharmacotherapy Sep 2020The purpose of this critical narrative review is to discuss the revised Starling equation for microvascular fluid exchange and the associated implications for... (Review)
Review
The purpose of this critical narrative review is to discuss the revised Starling equation for microvascular fluid exchange and the associated implications for intravenous fluid administration. PubMed (1946 to December 2019) and EMBASE (1947 to December 2019) were used, and bibliographies of retrieved articles were searched for additional articles. Articles pertaining to the revised Starling equation and microvascular fluid exchange. Additionally, prospective human studies involving the disposition and oncotic action of radiolabeled albumin and large randomized trials comparing fluid requirements associated with isotonic crystalloid and albumin administration were included. In the revised Starling equation, oncotic forces act across the endothelial cell layer, more specifically between the fluid in the vessel lumen and the protein-sparse subglycocalyx space. The revised Starling equation and radiolabeled investigations of albumin necessitate a reconsideration of conventional views of the plasma-expanding properties of exogenous albumin. Large clinical trials demonstrate that the administration of iso-oncotic or hyper-oncotic albumin solutions in patients undergoing resuscitation does not have the reductions in fluid requirements anticipated from a traditional understanding of the oncotic actions of albumin. When used as a resuscitation fluid, albumin does not have the degree of plasma expansion or intravascular retention commonly used to justify its use. The principles underlying the revised Starling equation in conjunction with data from radiolabeled studies of albumin and large clinical trials demonstrate that albumin does not have the perceived degree of plasma expansion or duration of intravascular retention beyond crystalloid solutions predicted by the classic Starling equation.
Topics: Albumins; Crystalloid Solutions; Fluid Therapy; Humans; Models, Biological; Osmotic Pressure; Plasma Substitutes; Rehydration Solutions; Resuscitation
PubMed: 32059617
DOI: 10.1177/1060028020907084 -
Acta Anaesthesiologica Scandinavica Aug 2022Albumin for intravenous infusion is marketed in two concentrations, 20% and 5%, but how they compare with regard to plasma volume expansion over time is unclear. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Albumin for intravenous infusion is marketed in two concentrations, 20% and 5%, but how they compare with regard to plasma volume expansion over time is unclear.
METHODS
In a prospective crossover study, 12 volunteers received 3 ml kg of 20% albumin and, on another occasion, 12 ml kg of 5% albumin over 30 min. Hence, equivalent amounts of albumin were given. Blood was collected on 15 occasions over 6 h. Mass balance and volume kinetics were used to estimate the plasma volume expansion and the capillary leakage of albumin and fluid based on measurements of blood hemoglobin, plasma albumin, and the colloid osmotic pressure.
RESULTS
The greatest plasma volume expansion was 16.0 ± 6.4% (mean ± SD) with 20% albumin and 19.0 ± 5.2% with 5% albumin (p < .03). The volume expansion with 20% albumin corresponded to twice the infused volume. One third of the 5% albumin volume quickly leaked out of the plasma, probably because of the higher colloid osmotic pressure of the volunteer plasma (mean, 24.5 mmHg) than the albumin solution (19.1 mmHg). At 6 h, the capillary leakage amounted to 42 ± 15% and 47 ± 11% of the administered albumin with the 20% and 5% preparations, respectively (p = .28). The corresponding urine outputs were 547 (316-780) ml and 687 (626-1080) ml (median and interquartile range; p = .24).
CONCLUSION
The most important difference between the fluids was a dehydrating effect of 20% albumin when the same albumin mass was administered.
Topics: Colloids; Cross-Over Studies; Humans; Kinetics; Plasma Substitutes; Prospective Studies; Serum Albumin; Volunteers
PubMed: 35491239
DOI: 10.1111/aas.14074 -
BMC Surgery Apr 2022A meta-analysis of randomized controlled trials was recently published in BMC Surgery that compared the use of human albumin with 6% hydroxyethyl starches 130/0.4 for... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A meta-analysis of randomized controlled trials was recently published in BMC Surgery that compared the use of human albumin with 6% hydroxyethyl starches 130/0.4 for cardiopulmonary bypass prime and perioperative fluid management in pediatric and adult cardiac surgery patients. The two plasma expanding solutions are described as equivalent for efficacy and safety outcomes, and, on that basis, the preferential use of hydroxyethyl starches 130/0.4 was recommended for economic reasons because of the higher unit costs of human albumin solutions.
RESULTS
In addition to the fact that trials were mostly small, single-center studies and the number of total participants was low, making the meta-analysis underpowered for several outcomes, selective reporting of data for ICU length of stay was identified. Re-calculation of statistics at higher precision showed that ICU length of stay of patients in the human albumin group was significantly shorter than that of patients in the 6% hydroxyethyl starches 130/0.4 group (standard mean difference - 0.181, 95% confidence interval - 0.361 to - 0.001, P = 0.049), which may offset any proposed economic advantage of using 6% hydroxyethyl starches 130/0.4. At the same time, the renal safety of 6% hydroxyethyl starches 130/0.4 in surgical patients is under regulatory review.
CONCLUSIONS
Underpowered trials and selective reporting may impair the validity of the meta-analysis. A more cautious conclusion about the interchangeability between human albumin and 6% hydroxyethyl starches 130/0.4 in cardiac surgery should have been reached.
Topics: Adult; Albumins; Cardiac Surgical Procedures; Child; Humans; Hydroxyethyl Starch Derivatives; Plasma Substitutes; Serum Albumin, Human
PubMed: 35410195
DOI: 10.1186/s12893-022-01588-x -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Apr 2021In recent years, it has been reported that the anti-shock effect of plasma substitutes in adult patients with major burn in shock stage is not good. However, due to the...
OBJECTIVES
In recent years, it has been reported that the anti-shock effect of plasma substitutes in adult patients with major burn in shock stage is not good. However, due to the shortage of clinical frozen plasma supply, it is impossible to guarantee that frozen plasma is used as colloidal solution for anti-shock treatment. The purpose of this study is to explore the effect of the infusion ration between frozen plasma and plasma substitutes on the prognosis of adult patients with major burn in shock stage.
METHODS
This study enrolled 586 adult patients with major burn by selecting the hospitalization burn patients, who had been hospitalized at the Jiangxi province burn center from September 2014 to April 2019. The patients with the infusion ratio of frozen plasma to plasma substitutes ≥2꞉1 at 48 hours after admission were included in the experimental group, otherwise they were included in the control group. The basic clinical data and clinical prognosis indicator in the 2 groups were compared. Logistic univariate regression analysis was used to screen the influential factors of 30-day mortality in adult patients with major burn, and logistic multivariate regression analysis was used to obtain independent risk and protective factors; Kaplan-Meier method was used to draw the survival curve of the 2 groups, and log-rank test was used to compare the 30-day survival rate of the 2 groups.
RESULTS
There were significant differences in the infusion volume of frozen plasma and plasma substitutes between the 2 groups at 48 hours after admission (both <0.05). The duration of mechanical ventilation in the experimental group was shorter than that in the control group, the percentage of continuous renal replacement therapy (CRRT) in the experimental group was lower than that in the control group, and the in-hospital mortality and 30-day mortality in the experimental group were lower than those in the control group, the differences were statistically significant (all <0.05). The percentage of burn area and total body surface area (TBSA) was an independent risk factor for 30-day mortality of adult patients with major burn (OR=1.228, 95% CI 1.010 to 1.439, =0.039), while the infusion ration between of frozen plasma and plasma substitutes 48 hours after admission was an independent protective factor (OR=0.016, 95% CI 0.001 to 0.960, =0.023). The 30-day survival rate of the experimental group was significantly higher than that in the control group (<0.001).
CONCLUSIONS
Infusion ration between frozen plasma to plasma substitutes at 48 hours after admission is an independent protective factor for 30-day mortality of adult patients with major burn. In the early stage of adult patients with major burn, frozen plasma should be used as the anti-shock therapy as far as possible (frozen plasma꞉plasma substitute ≥2꞉1) to improve the prognosis and reduce the of 30-day mortality.
Topics: Adult; Hospitalization; Humans; Plasma Substitutes; Prognosis; Retrospective Studies; Shock
PubMed: 33967086
DOI: 10.11817/j.issn.1672-7347.2021.190565 -
International Journal of Biological... Feb 2020As a natural and renewable biological macromolecule, dextran not only has excellent biodegradability, but also has good biocompatibility. Dextran and its derivatives are... (Review)
Review
As a natural and renewable biological macromolecule, dextran not only has excellent biodegradability, but also has good biocompatibility. Dextran and its derivatives are functional polymers for the construction of targeted drug delivery systems. Herein, the application of dextran as prodrug and nanoparticle/nanogel/microsphere/micelle carrier for targeting drug delivery system was summarized. It is clarified that dextran is an important biomaterial with application value.
Topics: Animals; Biocompatible Materials; Dextrans; Drug Carriers; Drug Delivery Systems; Humans; Micelles; Microspheres; Nanoparticles
PubMed: 31756474
DOI: 10.1016/j.ijbiomac.2019.11.151