Ascites and Peritonitis
John F. Pohl, Christopher Jolley, Daniel Gelfond in Pediatric Gastroenterology, 2014
Albumin is a plasma volume expander that improves arterial hypotension. Patients with hepatic impairment can be albumin deficient secondary to loss of the liver’s synthetic function. The use of intravenous albumin has been shown to improve diuretic response, decrease the need for paracentesis, and reduce the length of hospital stay and need for readmission in patients with ascites. Traditionally, 5% albumin infusions are used to expand the intravascular volume and to provide albumin. Studies have shown that hemodynamic instability, which is usually seen in large volume paracentesis, is uncommon, and thus volume expansion is usually not necessary. The use of 25% albumin infusions (0.5–1.0 g/kg dry weight) has become the standard of care for both adult and pediatric patients. An alternative plasma volume expander is dextran 70 which has been shown to have similar efficacy to albumin infusions.
Stimulation of Endogenous Fibrinolysis
Cornelis Kluft in Tissue-Type Plasminogen Activator (t-PA): Physiological and Clinical Aspects, 1988
Intravenous infusion of dextrans, especially dextran 70, appears to reduce the incidence of postoperative venous thromboembolism.48 Dextran has many effects on blood flow, hemorheology, hemostasis, and fibrinolysis; their relative contributions to the antithrombotic effect are not known.48 There are some reports of increased plasminogen activator levels following dextran infusion; levels of urokinase inhibition, plasminogen, and α2-macroglobulin do not appear to change.48 In vitro, dextran increases plasminogen activation by urokinase.49 However, dextran also appears to increase the lysability of fibrin by plasmin, both in clots50 and in thrombi formed ex vivo in the Chandler tube.51 The addition of streptokinase reduces thrombus size if dextran has been added to blood in vitro.52 This increased lysability of fibrin thrombi may result from an effect of dextran on their structure, such as an altered distribution of platelets when thrombi are formed in the Chandler tube,53 or a coarser fibrin network which protects plasmin from inactivation by α2-antiplasmin.49
Fluids and electrolyte management
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Geriatric Neuroanesthesia, 2019
The colloid fluids used today include albumin 5%, hydroxyethyl starch (HES), dextran 70, and gelatin. Albumin 5% expands the plasma volume by 80% (40), HES by 100% (41), and dextran 70 by slightly more than 100% of the infused amount. There are scarce data on gelatin, but the expansion is probably close to that of HES. The half-life for the intravascular persistence of these colloids is 110 min for albumin and HES, and 175 min for dextran 70 (42). There are no data on the intravascular persistence of colloid fluids during surgery, but a shorter half-life is implicated in inflammatory disease due to increased capillary leakage of macromolecules.
Alkoxy cyanoacrylate-based nanoparticles with stealth and brain-targeting properties
Published in Journal of Drug Targeting, 2022
Jimin Liu, Yunfeng Li, Shan Liu, Yi Zhang, Yuan Luo, Yang Yang, Xiaomei Zhuang, Xuanzhi Wang, Baoquan Zhao, Tao Xu, Liang Xu
After 0.04 g DEAE-Dextran (70,000 Da) and 0.06 g Dextran-70 were dissolved in 10 mL deionised water, the solution was adjusted to pH 2 with 0.1 M HCl. Then, 100 μL CA monomers in 500 μL acetonitrile were added in a dropwise fashion, after which the mixture was stirred with a magnet at room temperature for 10 h. The resulting suspension was neutralised with 0.1 M sodium hydroxide, then filtered and centrifuged at 4 °C and 40,000 rpm. The precipitate was resuspended in deionised water after freeze-drying to prepare a 10 μg/mL NP solution. After ASON was added at a mass ratio of 10:1 (NP:ASON) and incubated for 30 min, 1% Tween 80 (10 μL) was added. The mixture was incubated for 10 min to obtain the final ASON–NPs. The final concentration of ASON–NP stock solution was 10 μg/mL (equivalent to ASON). Unless noted otherwise, concentration values below represent the concentration of nucleic acid contained within the NP. And FITC is used to mark ASON.
GDNF enhances human blood-nerve barrier function in vitro via MAPK signaling pathways
Published in Tissue Barriers, 2018
Chaoling Dong, Eroboghene E. Ubogu
6.5 mm diameter polyester membrane Transwell® inserts with 3.0 µm pore size (Corning, catalog # 3472) placed in 24-well tissue culture plates were coated with GTA-crosslinked RTC followed by RTC gel coating, as previously described. pHEndECs were seeded and serum withdrawal performed 5 days after culture in regular growth medium. The permeability of confluent, optimally cultured pHEndEC layers to sodium fluorescein (Na-FITC, molecular weight 376 Da) and fluoresceinated high molecular weight (70 KDa) dextran (dextran-70-FITC) were independently determined across each transwell inserts 48 hours later, using previously published methods.19,37,59 Briefly, 100 μL of a 1 mg/mL solution of either Na-FITC or dextran-70-FITC in 1X PBS (warmed to 37°C) was added into each transwell insert placed in a 24-well tissue culture plate containing 600 μL of basal medium at 37°C for 15 minutes in a humidified incubator containing 95% air/5% CO2. The concentration of Na-FITC or FITC-dextran-70 kDa in the receiving well was determined fluorometrically against a standard curve of known concentrations using a Synergy 2 Multi-Mode microplate Reader (BioTeK, North Carolina, USA). The permeability coefficient is directly proportional to the ratio of solute that permeates the transwell membrane to the input, expressed as a percentage of the input.59
Pharmacokinetics, biodistribution and receptor mediated endocytosis of a natural Angelica sinensis polysaccharide
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Yu Zhang, Tao Zhou, Li Luo, Zheng Cui, Na Wang, Yamin Shu, Kai-Ping Wang
The plasma concentration-time profile of FA following an intravenous injection at a single dose of 12 mg/kg, shown in Figure 3, was consistent with a two-compartment model. It has been reported that the half-life period of polysaccharides is related to different molecular weight and dosages [33]. For instance, a typical two-compartment model of dextran in mouse plasma after intravenous administration was authenticated in previous studies [34], and the results demonstrated that the half-life period of dextran in blood increased along with the increase in its molecular weight. However, compared to dextran, the results of a pharmacokinetic study of FA did not confirm this conclusion. With a higher molecular weight and higher dosages (80 kDa, 12 mg/kg) relative to dextran (70 kDa, 5 mg/kg), the half-life period of FA in blood, determined to be 13.45 min, was significantly shorter than the expected value. Since ASP mainly contains galactose and dextran contains only glucose, differences in monosaccharide composition between ASP and dextran may be responsible for this phenomenon. Additionally, the large extent of organ accumulation also usually results in a rapid elimination from the bloodstream after the i.v. injection of water-soluble macromolecules. Therefore, we assumed that ASP could be primarily absorbed by the liver via the ASGPR. The hypothesis was then tested using a tissue distribution study of FA. The concentrations of FA in tissues at 30, 60 and 120 min are listed in Table 2. In all tissues studied, the highest levels of FA were observed at 60 min post-dose, and FA became undetectable in the brain beyond 120 min. It was found that the accumulation of FA in the liver was appreciably higher than in other tissues at all the time points, indicating that FA has a high affinity for the liver.
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