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Effects of Antithrombotic and Results of Drug Screening
Published in Josef Hladovec, Antithrombotic Drugs in Thrombosis Models, 2020
Dextran preparations serve, in general, as plasma volume expanders. They represent no uniform or homogeneous compound and various preparations differ particularly in the average molecular weight. Natural dextrans have a high molecular weight, while those used for therapeutic purposes are, in fact, partially degraded semisynthetic compounds. Standard preparations have a molecular weight of 70,000, but low molecular weight dextrans of about 40,000 are also often used and differ in some functional parameters.
Transfusion practice in resuscitation and critical illness
Published in Jennifer Duguid, Lawrence Tim Goodnough, Michael J. Desmond, Transfusion Medicine in Practice, 2020
Dextrans cause a dose-related bleeding tendency in vivo by inhibiting platelet aggregation, reducing activation of factor VIII, and promoting fibrinolysis.25 To minimize the risk of bleeding, it is recommended to limit the daily dextran dose to 20 ml/kg. Anaphylaxis is now a rare complication of dextran administration with an incidence of 0.032%. Dextrans can also coat the surface of red blood cells, which may lead to difficulty in crossmatching blood and may increase the erythrocyte sedimentation rate. Dextrans have also been implicated as a cause of acute renal failure resulting from a reduced filtration pressure secondary to the hyperoncotic state following administration.29 However, this mechanism is unproven, and renal failure occurs only exceptionally rarely with dextrans.
The Use of Tracers in Transport Studies
Published in Joan Gil, Models of Lung Disease, 2020
Maya Simionescu, Nicolae Ghinea
Neutral dextrans of various molecular weights and sizes were used as fluid-phase markers in studies of transendothelial transport in fenestrated (Simionescu et al., 1972) and glomerular capillaries (Caulfield and Farquhar, 1974). Dextrans remain as individual particles at high concentrations (10% w/v) in physiological solutions (such as 0.9% NaCl); dissolution of the tracer is accelerated by 50 min sonication at 20°C (Simionescu and Palade, 1971). To increase the contrast and definition of dextran and glycogen particles, a one-step fixation of the tissue using a mixture containing glutaraldehyde, formaldehyde, OsO4, and lead citrate in arsenate or phosphate buffer was devised (Simionescu at al., 1972). This mixture can be used in various buffers and gives good results as a general fixative for electron microscopy for tissues, cell suspensions, or isolated membranes or organelles (for details of the method, see Addendum). Iron-dextrans have been used as fluid phase markers by Herzog and Miller (1981). The advantage of using dextran for permeability studies stems from its biological nature, availability in a wide spectrum of sizes, and direct visualization. Of equal importance is that dextrans are well tolerated upon intravenous injection in vivo and do not induce vascular leakage (of histamine type) in mice and rats.
Polysaccharide dextran-based conjugate for selective co-delivery of two synergistic drugs docetaxel and docosahexaenoic acid to tumor cells
Published in Drug Delivery, 2023
Peng Dong, Hongshuai Lv, Weiping Jia, Jiaojiao Liu, Si Wang, Xiaohai Li, Jinghua Hu, Ling Zhao, Yikang Shi
Dextran is a natural polysaccharide that is composed of α-1,6-glycosidic linkages in the main chain and α-1,3-glycosidic linkages in the branched chains and similar to muscle glycogen or liver glycogen in structure (K. Liu et al., 2016). Originally dextran was approved as a plasma expander, but its desirable physicochemical characteristics such as water solubility, biocompatibility, biodegradability, and non-immunogenicity, along with its low cost and a history of clinical use make it an attractive system for drug delivery. Plenty of hydroxyl groups and terminal aldehyde groups presented on the dextran backbone provide potential functional sites for drug conjugation through direct or indirect methods (Hong et al., 2018; G. Huang & Huang, 2018; Hu et al., 2021). As drug delivery carrier, some of dextran-based DTX encapsulated and chemically conjugated nanoparticles have showed excellent antitumor activity (Alibolandi et al., 2016; Han et al., 2016; Raza et al., 2016). Similarly, many articles showed that dextran-based paclitaxel nanoparticles also exhibited superior antitumor effect than parent paclitaxel (Sugahara et al., 2007; P. Liu et al., 2015; Zhou et al., 2017; Chang et al., 2020).
Management of priming fluids in cardiopulmonary bypass for adult cardiac surgery: network meta-analysis
Published in Annals of Medicine, 2023
Chen-Yang Xian-Yu, Jian-Bo Xu, Yu-Tong Ma, Nian-Jia Deng, Yu-Ting Tao, Hui-Jun Li, Teng-Yu Gao, Jing-Ying Yang, Chao Zhang
No significant advantage was observed with the use of gelatin as a priming fluid. Notably, it had the highest rate of death among all fluids. A meta-analysis demonstrated that gelatin increased the risk of allergic reactions, mortality, kidney failure and bleeding [51]. In addition, the use of gelatin as a priming fluid is more expensive than other liquids. In contrast, dextran is a more effective and safer priming fluid. This study found that patients using dextran had lower mortality, shorter mean CPB, and less blood loss 24h after surgery. In addition, no other obvious disadvantages are observed. Clinical research found that compared with albumin, the extra did not compromise organ function, and no significant difference in blood loss or transfusion volume [26]. Normally, high doses of artificial colloids impair haemostatic function, but dextran does not [26]. However, the use of dextran may also lead to allergies. Studies have shown that the incidence of allergic reactions to dextran was 21.9 per 100,000 injections (0.0219%) [52].
The relationship between serum lipid and sudden sensorineural hearing loss
Published in Acta Oto-Laryngologica, 2023
Jiaying Huang, Yongtian Xu, Ling Li, Wei Ai
We collected the patient’s gender, age, the start of treatment, main symptoms now, the hearing level at the beginning, and hearing improvement after treatment. All patients eligible for ISSNHL were hospitalized within one day after the onset of the disease. For serological indicators, blood specimens were obtained by fasting on the first day after admission. TC levels were measured using standard methods. Medical treatments consisted of the intravenous administration of high-dose steroids and peripheral vasodilators in combination with the intravenous administration of dextran. The steroid administration protocol during hospitalization included tapered doses of intravenous Dexamethasone (12 mg for 3 days, 8 mg for 2 days, and 4 mg for 1 day), followed by outpatient oral prednisolone (20 mg/day for another 8 days). During inpatient care, the pure-tone audiogram (PTA) was performed every 2 days and was followed at 1, 4, 8, and 12 weeks after discharge [8].