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PubMed1977

[Dextran for the prophylaxis of postoperative thromboembolism (author's transl)].

Dextran has a well-documented antithrombotic effect that is due to a reduction in platelet adhesions, increased lysability of thrombi, and improved blood flow. Anaphylactoid reactions may occur during the first 30--50 ccm of dextran infusion. They have an incidence of 1:80000 during anesthesia. The main advantage of dextran prophylaxis is the lack of bleeding complications. It is extremely effective in lowering the incidence of lethal pulmonary embolisms.

Anaphylaxis↗

PubMed1982

[The elimination of hydroxyethyl starch 200/0.5, dextran 40 and oxypolygelatine (author's transl)].

After withdrawal of 400 ml whole blood and subsequent infusion of 500 ml of a colloidal plasma substituent, the intravascular and renal colloid elimination was investigated in 40 test subjects. The individual colloidal solutions could no longer be demonstrated in the intravascular space after the following times: 10% hydroxyethyl starch 200/0.5 (anthrone method) after six weeks, 10% dextran 40 (anthrone method) after two weeks, 6% hydroxyethyl starch 200/0.5 (anthrone method) after four weeks and 5.5% oxypolygelatine (hydroxyproline method) after two days. Colloidal plasma substitutes are polydisperse solutions with various molecular weights and degree of hydroxyethylation and therefore, also have a large number of different elimination constants. With repeated application, the intravascular colloid concentration shifts in favour of the molecules with a longer half life which are difficult to eliminate. The elimination of the clinically employed dextran 40 and oxypolygelatine solution could be best described with an open two-compartment model. As a result of its greater heterogeneity, the elimination of the moderately high molecular weight hydroxyethyl starch 200/0.5 could only be characterized approximately even assuming three elimination constants. In the first four days, the hydroxyethyl starch 200/0.5 was more rapidly eliminated compared to dextran 40. However, subsequently a very much lower elimination from the intravascular space was found for about 3% of the administered hydroxyethyl starch 200/0.5. Oxypolygelatine was eliminated especially rapidly. Accordingly, the greatest renal clearance was found for oxypolygelatine, which showed a close relation to the molecular weight. On the other hand, a rapid elimination simultaneously is followed by a correspondingly lower volume effect.

Adult↗

PubMed1986

Is albumin synthesis regulated by the colloid osmotic pressure? Effect of albumin and dextran on albumin and total protein synthesis in isolated rat hepatocytes.

In order to study the influence of the colloid osmotic pressure on albumin and total liver protein synthesis, rat hepatocytes were isolated by collagenase perfusion and incubated in Krebs-Ringer-buffer for 4 h. The colloid osmotic pressure produced by different bovine serum albumin (BSA) or dextran 60 concentrations varied from 3 to 80 mm Hg. A physiological colloid osmotic pressure of 20 mm Hg was obtained with 5.7 g BSA or 3.7 g dextran 60 per 100 ml of buffer. Albumin synthesis was measured by Laurell rocket immunoelectrophoresis. Total liver protein and total secretory protein synthesis were determined by the measurement of 1-14C-leucine incorporation. Albumin synthesis was not primarily regulated by the colloid osmotic pressure as was demonstrated by a lack of inhibition after addition of BSA. There was no significant influence of the oncotic pressure on the incorporation of 14C-leucine into total liver proteins. The incorporation into total secretory proteins was inhibited by an increasing colloid osmotic pressure, mediated either by BSA or dextran, suggesting an inhibition of the secretion of plasma proteins other than albumin.

Animals↗

PubMed1987

[Hemodilution in patients with stage IIb peripheral arterial occlusive disease: prospective randomized double-blind comparison of middle-molecular weight hydroxyethyl starch and low-molecular weight dextran solution].

Isovolemic hemodilution is a simple method of treating patients with peripheral arterial occlusion disease and hematocrit values of 43% or more. Dextran, a plasma substitute, has been used for that purpose since the early 1950s. However, the use of dextran in some diseases, e.g., hemorrhagic diathesis, kidney insufficiency, and microangiopathy is not without risk. Anaphylactic reaction, too, has occurred in some cases. Since the end of the 1970s hydroxyethyl starch, a plasma substitute, is available for the therapy of microcirculatory disorders and hemorrhagic diathesis. The side effects of hydroxyethyl starch are less serious and anaphylactic reactions are less frequent and moderate in extent. The clinical efficacy of both substances was compared in this survey. It could be stated that middle molecular hydroxyethyl starch is even clinically superior to low molecular dextran because the distance that the patients could walk increased significantly.

Arterial Occlusive Diseases↗

PubMed1987

Influence of dextran on pneumococcal septicemia in splenic artery-ligated or splenectomized rats.

Splenic artery ligation is one of several methods in splenic preservation. In this experimental work the susceptibility of splenectomized rats and rats treated with splenic artery ligation to pneumococcal infection and the influence of the plasma expander dextran in the same groups were studied. The mortality among splenectomized rats was 100% vs nil after sham operation. Animals treated with splenic artery ligation and saline had a 23% mortality in pneumococcal septicemia, significantly different (P less than 0.05) from the 59% mortality after splenic artery ligation and dextran. A significant increase (P less than 0.05) in number of abscesses was also seen among rats given dextran.

Abscess↗

PubMed1975

p-CMB-dextran T 10. A useful tool in evaluating the functional importance of superficial SH-groups in rat adipocytes.

A large SH-blocking reagent p-CMB-dextran T 10 (MW about 10,000) was applied to isolated rat adipocytes. This compound possesses the same reactivity towards SH-groups as uncoupled p-CMB. P-CMB-Dextran T 10 did not influence the basal glucose uptake in contrast to uncoupled p-CMB. The results are discussed with respect to the usefulness of p-CMB-dextran T 10 in evaluating the role of superficial SH-groups in various membrane functions.

Adipose Tissue↗

PubMed1983

Influence of dextran macromolecules on the glycosaminoglycan metabolism of cultured corneal stroma and keratoconus fibroblast.

The addition of dextran macromolecules to the incubation medium at 1% and 10% concentration does not cause any alteration of sulphated glycosaminoglycan synthesis or its distribution within the various cell compartments. This is in contrast to observations on a serum-free and dextran-enriched medium in which glycosaminoglycan distribution of stored corneal tissue remains normal and the concentration of keratan sulphate is maintained. The mechanism of this action is unknown. Some experimental findings of the influence of dextran upon cell metabolism are discussed.

Cells, Cultured↗

PubMed1996

Dextran sulfate sodium (DSS) induced experimental colitis in immunodeficient mice: effects in CD4(+) -cell depleted, athymic and NK-cell depleted SCID mice.

Administration of dextran sulfate to mice, given in the drinking water results in acute or subacute colonic inflammation, depending on the administration protocol. This colonic inflammation exhibits ulceration, healing and repair, and a therapeutic response that makes it valuable for the study of mechanisms that could act in the pathogenesis of human ulcerative colitis, a disease thought to have an immunologically dependent pathogenesis. To investigate if immunological mechanisms were involved in the induction of colonic inflammation in this model, mice with different degrees of immunodeficiency were used. It was shown that dextran sulfate induced colitis could be induced in Balb/c mice depleted of CD4(+) helper T cells by treatment with monoclonal antibodies preceded by adult thymectomy. The depletion of CD4(+) was verified by flow cytometric analysis. Furthermore, the colonic inflammation could equally be induced in athymic CD-1 nu/nu mice lacking thymus-derived T cells, in T and B-cell deficient SCID mice, and also in SCID mice depleted of NK cells by treatment with anti-asialo GM1 antibodies. The NK-cell depletion was verified by measuring spleen NK-cell activity. The resulting colonic inflammation in all these types of deficient mice was qualitatively comparable, as shown by clinical and histological appearance. These results indicate that the presence of functional T, B and NK cells is not crucial for the induction of dextran sulfate colitis in mice.

Administration, Oral↗

PubMed1996

Population changes in immunoglobulin-containing mononuclear cells in dextran sulfate sodium-induced coltitis.

To investigate the relation of immunoglobulin-containing cells in the colonic mucosa to mucosal inflammation, we immunohistochemically examined the localization of immunoglobulin-containing mononuclear cells in the lamina propria in dextran sulfate sodium induced colitis in mice. Mice were treated repeatedly with 3% dextran sulfate sodium (MW 54,000) solution or distilled water for a total of 170 days (chronic model), or for 85 days (subacute model) or for 10 days (acute model). IgG, IgA, and IgM-containing mononuclear cells were studied by enzyme immunostaining. The number of IgA- and IgG-containing cells gradually and significantly increased in the acute, subacute, and chronic models, in that order (P < 0.01 or 0.05). However, the numbers of IgM-containing cells in the three models were similar to that in the controls. These findings resembled those of human ulcerative colitis. In this dextran sulfate sodium-induced colitis, IgA-containing mononuclear cells may play an essential role in the mucosal immune system is the acute, subacute, and chronic phases. The finding that IgG-containing mononuclear cells increased substantially in the chronic phase suggests that IgG plays an important role in the mucosal inflammatory reaction during the chronic phase.

Acute Disease↗

PubMed1993

Effects of TC7 associated to 32% dextran 70, heparin and carboxymethylcellulose in adhesion prevention in the rat.

Experimental studies on adhesion formation 90 days after laparotomy in the rat were done. Uterine horn adhesions after standardised procedures and trauma in a control group of 10 rats were compared with those obtained in six other 10-rat groups in whom heparin, carboxymethylcellulose (CMC), 32% dextran 70 and the fabric TC7 either alone or in various combinations were used at the time of laparotomy. Dextran 70 and CMC used on their own appeared to reduce adhesion formation but the improvement did not achieve statistical significance when compared with the control group. TC7 used alone had no anti-adhesion effect; when used with CMC or dextran 70, TC7 did not enhance the anti-adhesion benefit conferred by either substance used on its own.

Animals↗

PubMed2001

The role of microflora in the development of intestinal inflammation: acute and chronic colitis induced by dextran sulfate in germ-free and conventionally reared immunocompetent and immunodeficient mice.

One-week dextran sulfate treatment of conventional (CV) immunodeficient (SCID) mice gave rise to acute colitis in the colon mucosa; germ-free (GF) SCID mice did not exhibit any changes in colon morphology. Dextran sulfate application to CV immunocompetent (BALB/c) mice did induce substantial changes in the colon mucosa (grade 4); GF BALB/c mice showed mild changes in the colon morphology (grade 1) only. GF SCID mice and CV SCID mice died during the second round of dextran sulfate treatment suffering from chronic colitis; GF BALB/c mice exhibited mild crypt distortion while CV BALB/c mice showed a complete loss of the surface epithelium (grade 4), accompanied by T and B lymphocyte infiltration.

Animals↗

PubMed1998

Volume kinetics of Ringer's solution and dextran 3% during induction of spinal anaesthesia for caesarean section.

PURPOSE: To study how the body handles fluid given intravenously during the onset of spinal anaesthesia in women scheduled for Caesarean section. METHODS: The effect of spinal anaesthesia on the volume kinetics of a constant-rate infusion of 25 ml.kg-1 of Ringer's solution (n = 11) and 10 ml.kg-1 of dextran 3% 60 (n = 8) was studied before elective Caesarean section. Measurements of the blood haemoglobin concentration and urine excretion served as input variables in calculations of the size(s) of the body fluid spaces expanded by the infused fluid. The blood glucose level was also monitored. RESULTS: When a one-volume kinetic model were fitted to the data, spinal anaesthesia reduced the size of the expanded body fluid space by 30% (Ringer's) and 58% (dextran) (P < 0.02) When a two-volume model was statistically justified, anaesthesia reduced the rate of fluid equilibration between the two expanded body fluid spaces by 47% and 19%, respectively (P < 0.04) The baseline volume for the primary (central) fluid space was smaller than the expected plasma volume; 1.5 l for Ringer's solution and 0.9 l for dextran. Only small changes in the blood glucose concentration were found. CONCLUSION: The onset of spinal anaesthesia induces acute changes in the body's handling of infused fluid that can be described by volume kinetic analysis.

Adult↗

PubMed2006

Epidural dextran-40 and paramethasone injection for treatment of spontaneous intracranial hypotension.

PURPOSE: This report describes treatment with epidural dextran-40 and paramethasone injection of postural headache resulting from spontaneous intracranial hypotension in a pregnant patient. CLINICAL FEATURES: A 39-yr-old pregnant woman consulted the pain clinic for the assessment of a debilitating postural headache which was non-responsive to conventional analgesic treatment. Clinical findings and cranial magnetic resonance imaging indicated the diagnosis of spontaneous intracranial hypotension syndrome. Treatment with an epidural blood patch was not undertaken for several reasons. A lumbar epidural injection with dextran-40 and paramethasone led to a significant improvement in the symptoms and allowed a progressive discontinuation of adjuvant treatment with oral steroids, with complete resolution of symptoms. CONCLUSION: We report a case of spontaneous intracranial hypotension in a pregnant patient successfully treated by epidural injection of dextran-40 and paramethasone, with adjuvant oral steroid therapy. Clinical trials are warranted to establish the efficacy of this treatment as an alternative to the epidural blood patch administration.

Adult↗

PubMed2005

One-step synthesis of amino-dextran-protected gold and silver nanoparticles and its application in biosensors.

A sensitive method for the detection of the lectin protein concanavalin A (Con A) was developed using amino-dextran (AD)-protected gold (AD-Au) and silver nanoparticles (AD-Ag) as sensitive optical probes. The AD-Au and AD-Ag nanoparticles were synthesized by directly applying amino-dextran as a reductive and protective reagent. The size of the nanoparticles could be altered by changing the molar ratio of AD to the metal salt. The amino-dextran bound to Con A by forming a 4:1 Au-Con A complex at neutral pH, and the nanoparticles were induced to aggregate by Con A. The absorption intensity of the nanoparticles decreased linearly with as the Con A concentration was increased from 3.85 x 10(-8) to 6.15 x 10(-7) M. The Au-Con A complex was dissociated by the disaccharide isomaltose, which has a higher affinities for Con A than Au; this competitive strategy could also be used to detect similar types of saccharides.

Biosensing Techniques↗

PubMed2003

Platelet-activating factor, a critical mediator in the pathogenesis of dextran sulfate sodium-induced colitis in rats.

PURPOSE: Disorder of mucosal immunity based on an imbalance between proinflammatory and anti-inflammatory cytokines is believed to be a major factor in the pathogenesis of ulcerative colitis. Platelet-activating factor potentially stimulates the production of proinflammatory cytokines and recruits inflammatory cells. The aim of this study was to determine whether and to what extent platelet-activating factor plays a role in the pathogenesis of ulcerative colitis. METHODS: Using dextran sulfate sodium-induced colitis in rats as a model of ulcerative colitis, we analyzed the composition of cellular infiltrates and the local tissue expression of messenger ribonucleic acid for cytokine-induced neutrophil chemoattractant and tumor necrosis factor-alpha. To directly assess the impact of platelet-activating factor on the development of colitis, we also determined the efficacy of a specific platelet-activating factor receptor antagonist for preventing dextran sulfate sodium-induced colitis. RESULTS: The activity of colitis was well correlated with the upregulation of cytokine-induced neutrophil chemoattractant and tumor necrosis factor-alpha messenger ribonucleic acid in local tissues and infiltration of cytokine-induced neutrophil chemoattractant-positive neutrophils and ED1-positive macrophages. The platelet-activating factor receptor antagonist effectively ameliorated colitis, along with causing a decrease in the tissue cytokine-induced neutrophil chemoattractant messenger ribonucleic acid level and a decline in neutrophil and macrophage infiltration. However, the antagonist did not alter tissue levels of tumor necrosis factor-alpha messenger ribonucleic acid. CONCLUSION: Platelet-activating factor plays a critical role in the pathogenesis of dextran sulfate sodium-induced colitis through recruitment of cytokine-induced neutrophil chemoattractant-positive neutrophils and macrophages and/or stimulation of cytokine-induced neutrophil chemoattractant release from activated neutrophils. The tissue level of tumor necrosis factor-alpha messenger ribonucleic acid does not closely reflect the activity of colitis.

Analysis of Variance↗

PubMed1987

Hemodynamic effect of dextran, dobutamine, and pericardiocentesis in cardiac tamponade secondary to subacute heart rupture.

Seventeen patients with acute myocardial infarction and tamponade after subacute ventricular free-wall rupture were treated with dextran, dobutamine, and pericardiocentesis before definitive surgical repair. In all of the patients the diagnosis was confirmed anatomically. Dextran (200 to 900 ml), administered to 10 patients, induced a significant increase in systolic blood pressure, cardiac index, stroke index, right atrial pressure, and pulmonary capillary pressure. Dobutamine (500 micrograms/min for 20 to 40 minutes), was infused in 16 patients and induced a significant increase in systolic blood pressure, cardiac index, stroke index, and heart rate. Pericardiocentesis, with extraction of 150 to 500 ml, was performed in five patients. It produced a significant increase in systolic blood pressure, cardiac index, and stroke index and a significant decrease in right atrial pressure and heart rate. The best results were obtained after pericardiocentesis. However, it must not be performed in every case because of its potential risk. Dextran and dobutamine may be sufficient in many cases to support these patients before surgery.

Adult↗

PubMed1975

The prevention of postoperative pulmonary emboli with low-molecular-weight dextran.

The effect of low-molecular-weight (LMW) dextran as a prophylactic agent in the prevention of pulmonary emboli and deep vein thrombophlebitis was evaluated. Eighty-seven patients were given LMW dextran during and after surgery on a predetermined schedule during the study period. These 87 patients were compared to 103 patients who, in the previous year and a half, received no pharmacologic prophylaxis. In the dextran group there was one suspected pulmonary embolus, no case of deep vein thrombophlebitis, and no death. In the control group there was one case of deep vein thrombophlibitis, seven cases of pulmonary emboli, and three deaths directly attributable to pulmonary emboli.

Adult↗

PubMed1983

Fetal blood volume responses to intravenous saline solution and dextran.

The purpose of this study was to determine to what extent the volume of blood circulating in the fetus can be increased by intravascular infusions of either isotonic saline solution or high-molecular weight dextran in saline solution. Unanesthetized, chronically catheterized fetal sheep that averaged 130 days' gestation were studied. In seven fetuses, 50 to 100 ml of warm saline solution (i.e., an average of 19.5% of the initial fetal blood volume) was infused into a vein over 5 minutes, and changes in blood volume were determined 10, 20, and 30 minutes after the infusion was begun. At these times, an average of only 15%, 9%, and 7%, respectively, of the infused volume remained in the fetal circulation. A second infusion of saline solution into these fetuses gave intravascular retentions that averaged 17%, 6%, and 6% at 10, 20, and 30 minutes, respectively. In five fetuses, a 6% solution of dextran 70 that averaged 14.9% of the initial fetal blood volume was infused over 5 minutes. The intravascular retentions averaged 80%, 63%, and 55%, respectively, at 10, 20, and 30 minutes after the infusions were started. Under comparable conditions in the adult, blood volume expansion 30 minutes after rapid infusions averages 20% to 40% of the infused volume for saline solution and 150% to 200% for 6% dextran 70. Thus, the present study suggests that intravascular infusions of crystalloid solutions have very little effect on fetal blood volume, whereas oncotic solutions cause only moderate blood volume expansion.

Animals↗