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PubMed1984

Oral anticoagulants and dextran for prevention of venous thrombosis in orthopaedics.

A hundred and fifty-two patients who were to undergo major orthopaedic surgery were divided into two groups in order to study the value of dextrans administered as adjuvants to oral anticoagulants in the prevention of deep venous thrombosis. The control group had oral anticoagulants only from the evening before the day of operation, aimed at the 15 per cent thrombotest level. The dextran group had peroperative and postoperative dextran infusions as well. Radionuclide venography was used for thrombosis detection. The dextran group had a lower incidence of thrombosis, but more haemorrhagic problems. The incidence of thrombosis was high in both groups.

Acenocoumarol↗
PubMed1988

Mechanism of erythrocyte aggregate formation in presence of magnetic field and dextrans as analyzed by laser light scattering.

The mechanism of erythrocyte aggregation has been studied in normal plasma, dextran 40 and dextran 70 suspensions in presence and absence of magnetic field at a concentration of 5 percent by laser light scattering. The inhomogeneous magnetic field enhances the aggregating tendency of normal erythrocytes. The growth of aggregates due to dextran 70 is enhanced in presence of magnetic field. On the other hand the disaggregating effect of dextran 40 is reduced due to this field. The induced changes due to magnetic field during the development of erythrocyte aggregates in these media are determined.

Dextrans↗
PubMed2000

Binding of 125I after administration of 125I-EGF-dextran, 125I-EGF or 125I to human bladder cancer spheroids.

The binding of a targeting agent, 125I-EGF-dextran, to epidermal growth factor (EGF) receptors in tumour spheroids of a human bladder cancer cell line was studied. The accumulation of radioactivity was continuous up to at least 48 h in the peripheral cells of the spheroids, which in comparison with the binding pattern of 125I-EGF indicated that the cells had a limited capacity to degrade the EGF-dextran. The 125I-EGF-dextran was of two different sizes, 28 and 76 kDa, but this did not affect the binding patterns and the results were very similar. The EGF-dextran conjugates had qualities that are of interest for tumour targeting.

Animals↗
PubMed1989

Low dose dextran 40 in reconstructive hip surgery patients.

Preoperative and postoperative bilateral lower extremity venography was used to evaluate the efficacy of low dose dextran 40 in prophylaxis of deep venous thrombosis in reconstructive hip surgery patients. Patients were given dextran 40 at 50 cc/hr, with 250 cc given perioperatively and 500 cc given on postoperative days two and four. Five of 227 patients had positive venograms preoperatively. Of these 227 patients, 179 met protocol requirements and had venography postoperatively. Venous thrombosis occurred in 33 (18%) of those studied postoperatively. Of these, 11 were calf clots without extension to the popliteal region. Therefore, there were 22 patients (12%) with femoral or popliteal involvement overall. There were two deaths, neither of which was secondary to pulmonary embolus or a complication of dextran. There were two wound complications. These results suggest that low dose dextran 40 administered as indicated is a safe and efficacious means of deep venous thrombosis prophylaxis in reconstructive hip surgery patients.

Arthroplasty↗
PubMed1976

Dextran degrading activity of oral microbial flora.

Dextran degrading activity of the human oral microflora was detected by culturing in TYD broth (Tryptose 1.0%, Yeast extract 0.3%, Dextran T-150 (Pharmacia, MW 150,000) 0.15%). All of the plaue and saliva samples collected from 10 subjects showed a dextran degrading activity, both cultured aerobically and anaerobically, while the anaerobic culture was more active than the aerobic. Furthermore, some individual differences were observed in their activity. Crude enzyme(s) was extracted from the supernatant of a mixed culture of plaque sample by adding ammonium-sulfate to 0.6 and 0.8 saturation (called E-1 and E-2, respectively). E-1 contained 2 dextran-degrading enzymes, one being thought to be an endo-enzyme, with the optimal of H being 5.0 and the other an exo-enzyme with the optimal pH being 7.0-7.5. On the other hand, E-2 contained 1 enzyme of the endo-type. Thirteen strains producing dextranase were isolated from the plaque and were identified as Bacteroides oralis-like organisms. Several other organisms were thought to produce dextranase, although we failed to isolate them in this experiment.

Adult↗
PubMed2000

[Magnetic drug delivery system--adriamycin-carboxymethyl dextran magnetic nanoparticles].

A novel magnetic drug carrier-carboxymethyl dextran magnetic nanoparticles(CMD MNPs) was prepared. Adriamycin (ADR) was coupled with two types of carrier-neutral dextran MNPs and anionic CMD MNPs, by periodate oxidation. The physico-chemical characteristics and the magnetic guidance effects in vitro and in vivo of ADR-CMD MNPs were studied. The distribution profiles of liver and spleen in mice were studied for both ADR-dextran conjugate MNPs and ADR-CMD conjugate MNPs. The results showed ADR-CMD conjugate MNPs possessed superparamagnetism, the mean diameter was 56 nm, the mass magnetic susceptibility was 1.06 x 10(-4) emu.g-1, and the drug loading was 12.4%. The distribution profiles in liver and spleen revealed that conjugation with neutral dextran MNPs, excessive accumulation of loaded ADR was found in liver and spleen after intravenous administration, while conjugation with CMD MNPs gave a markedly lower concentration in these organs, which indicated less uptake of ADR-CMD conjugate MNPs by reticuloendothelial system(RES) and the advantage of delivering loaded drug to sites other than the RES; thus it opens a new perspective for the active delivery of drug.

Animals↗
PubMed1975

Fatal anaphylaxis after intravenous iron dextran.

This report records the first reported case of a fatal anaphylactic reaction to an intravenous infusion of iron dextran. An elderly woman was given an infusion of iron dextran in 5% dextrose. Shortly after the infusion started, she developed laryngeal stridor, shock, respiratory arrest, and died despite attempts at resuscitation. Necropsy findings are described and are consistent with death due to anaphylaxis. With the increased parenteral use of dextran and iron dextran complexes it is important for the clinician to be aware of the hazards of anaphylactic reactions. Since the reactions generally occur shortly after the administration has begun, a physician should be in attendance during the infusion of the first 25 cm3 (5 to 10 min). He should be able to promptly recognize and treat the asphyxia and hypotension should it occur. It is also important for the pathologist to be aware of the occurrence of anaphylaxis after the use of these drugs. However, the cause of death should not be based solely on the presence of classic clinical features of fatal anaphylaxis. Specific features of anaphylaxis should be searched for at autopsy and other causes of sudden death must be ruled out.

Aged↗
PubMedDate not supplied

[Use of a freeze-drief culture of Leuconostoc mesenteroides for the synthesis of dextran].

The influence of a prolonged storage of the freeze-dried culture Leuconostoc mesenteroides strain SF-4 on its capacity for the dextrane synthesis has been studied. The culture has maintained its normal viability for 12 years (the observation time) without changes in the cell morphology and capacity for the dextrane synthesis. The structure of dextrane synthesized by the revived culture L. mesenteroides has been similar to that of dextrane synthesized by the culture L. mesenteroides preserved via passages.

Dextrans↗
PubMed1975

The nature of arterial healing following dextran treatment of experimental small artery trauma.

Vascular thrombosis is a major cause of morbidity and death. Because of the many variables involved with thrombosis in patients, major advances in treatment often depend upon design and study of adequate experimental models which provide a degree of control of the variables. Arterial trauma was produced in small femoral arteries 3 mm. or less in diameter by a standardized intimectomy technique. One group of animals was treated with an equal volume of saline and served as controls. Serial sections of blood vessels at graded time intervals from one hour to 90 days were studied. The damaged blood vessels of dextran-treated animals did not thrombose and provided an opportunity for studying the mechanism of healing in traumatized blood vessels which remained patent. The damaged blood vessels of saline-treated animals uniformly thrombosed and eventually healed for scar formation with evidences of attempts at recanalization. The blood vessels of dextran-treated animals remained open for as long as 90 days and were re-endothelialized and healed. What appears to be beginning re-endothelialization of blood vessels of dextran-treated animals was observed as early as 48 hours. In a model experimental setting, dextran has been shown to prevent thrombosis and permit healing in small arteries subjected to a standardized surgical trauma.

Animals↗
PubMed1975

[Antistreptolysin-titre under the use of traditional methods and after saturation with dextran sulfate].

1,700 blood samples of healthy test persons without clinically and paraclinically provable streptococcal diseases were examined for their content of antistreptolysin. Beside the usual method parallel determinations were carried out after addition of dextran sulfate. Thus increases of unspecific antistreptolysin titres shall be in most cases excluded, above all by the influence of the lipoproteins. The absorption of dextran sulfate led to the decrease of the antistreptolysin titre by 12.33%. Furthermore could be proved that the average antistreptolysin titre of female test persons is ca. 20 antistreptolysin units below the titre of male test persons, that seasonal variations of the antistreptolysin titre with the highest titres appear in the first and third quarter which may be explained by a bad unspecific defensive condition, that, furthermore, the antistreptolysin titres increase to the 14th year and then continuously decrease and that in new-born children the arithmetic mean value of the antistreptolysin units is significantly higher than in their mothers. Hereby an active influence of the placenta on the transmission of antibodies seems to be possible. Though a slightly increased financial expenditure is necessary for dextran sulfate, temporarily and concerning working technique, however, no larger loads appear, it is justifiable to perform the determination of antistreptolysin titres only by means of dextran sulfate-absorbed sera, since in this way a considerable number of unspecific and misleading reactions can be excluded.

Adolescent↗
PubMed1976

A semiautomated micromethod for dextran in the presence of glucose.

A semiautomated method for microanalysis of dextran with anthrone reagent has been developed. The method utilizes the Technicon inulin manifold and other standard AutoAnalyzer equipment. Since the anthrone method is sensitive to plasma glucose, a glocuse oxidase method which eliminates glucose in samples to be analyzed for dextran has also been developed. When solutions containing 50 mg. per 100 ml. of dextran were compared to solutions containing 50 mg. per 100 ml. of dextran plus up to 200 mg. per 100 ml. glucose, no significant difference was observed. The coefficient of the anthrone-glucose oxidase method is 0.039, which is within the error of the AutoAnalyzer itself.

Autoanalysis↗
PubMed1992

The effect of somatostatin, gabexate mesilate and dextran 40 on the microcirculation in sodium taurocholate-induced pancreatitis.

In vivo microscopy was performed to assess the effect of dextran 40, gabexate mesilate and somatostatin on the microcirculation in sodium taurocholate-induced pancreatitis in rats. Intraductal infusion of 0.4 ml of a 4% solution of sodium taurocholate decreased capillary blood flow, induced capillary stasis and increased vascular permeability in the head of the pancreas. Dextran 40, gabexate mesilate and somatostatin improved capillary blood flow in the initial phase of acute pancreatitis significantly and prevented stasis in 5 of 9, 3 of 8 and 7 of 10 (p < 0.05) cases. Only dextran 40 reduced the increase of vascular permeability. Decrease of capillary blood flow, capillary stasis and vascular permeability changes are important factors contributing to the pathogenesis of sodium taurocholate-induced pancreatitis. Dextran 40, gabexate mesilate and somatostatin exert a beneficial effect on the microcirculatory changes in this model of acute pancreatitis.

Animals↗
PubMed1992

Antiinflammatory effect of a protein kinase C inhibitor (K-252a) on the development of the dextran-induced paw edema in the rat (preliminary results).

The effect of a metabolite of Nocardiopsis sp. as a protein kinase C inhibitor from microbial origin was investigated on the onset and development of dextran-induced paw edema in the rat. It was published that this compound (K-252a) interferes with histamine release from mast cells, while dextran-induced paw and nose edema are induced by vasoactive agents, like histamine etc., released from the disrupted mast cells. The antiinflammatory effect of the K-252a is effectuated by the inhibition of protein kinase C. Groups of male Wistar rats with 180-200 g b.w. were used; each group consisted of 10-10 rats. The following groups were consisted: rats given orally DMSO (control), rats given 1 mg/kg, or 3 mg/kg b.w. of K-252a dissolved in DMSO and given p.o. one hour before dextran injection. Dextran (BDH Chem. LTD, molW: 200.000, England) was injected intraperitoneally in 10% solution, in a dose of one ml/100 g b.w. Volume of the hind leg was measured by a mercury plethysmometer. Time-sequence of the edema was followed. Increase in volume of hind leg paw was related to its 0-min volume in %. Results were analyzed by the Kruskal-Wallis-test. Edema of the legs and noses appeared in each of the control rats in one hour. The 1 mg/kg dose of K-252a retarded the appearance of the edema by 1 hour, the 3 mg/kg dose, however, prevented its onset for 4 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

[Characteristics of drug-release in vitro of different dextran-dexamethasone conjugates].

AIM: To evaluate the effects of molecular weight of dextran on drug-release of conjugate in vitro by screening colon-specific conjugates. METHODS: The conjugates, synthesized with different molecular-weight dextran and dexamethasone, were incubated in the contents of different parts of rat gastrointestinal tract at 37 degrees C. The release of dexamethasone(Dex) and dexamethasonehemisuccinate was determined by HPLC. The mobile phase consisted of 35% acetonitrile and 65% trisodium citrate (50 mmol.L-1, adjusted to pH 4.1 with phosphoric acid). RESULTS: There was no release of dexamethasone or dexamethasonehemisuccinate from conjugates in the stomach contents. The amount of Dex (including dexamethasonehemisuccinate) released from DexD26 in the contents of colon and cecum was shown to be 4.0 times higher than that released in the contents of proximal and distal small intestine while the amount of Dex (including dexamethasonehemisuccinate) released from DexD50 was shown to be 3.6 times higher. The amount of Dex (including dexamethasonehemisuccinate) released from DexD2 in the contents of colon and cecum and from DexD7.6 were 2.0 times and 1.9 times higher, respectively, than that released in contents of proximal and distal small intestine. CONCLUSION: The molecular weight of dextran showed marked effect on drug-release of the conjugate in vitro, and the conjugates with larger molecular-weight dextran have great potential in colon-specific delivery of dexamethasone.

Animals↗
PubMed1992

[Effect of low and high molecular weight dextrans on selected serum lipid parameters. 1].

Three male patients with hyperlipidaemia were given daily infusions of dextran over a period of 10 days. Plasma levels of total cholesterol, LDL and HDL cholesterol, apolipoprotein B and AI and triglycerides were analysed after the infusion of dextrans different in dose and molecular size. Dextrans caused alterations of some plasma lipids and lipoproteins exceeding the haemodilution effect. The degree of lipid lowering depends on the volume and molecular size of the administered dextran.

Adult↗
PubMed1992

MR imaging of acute myocardial infarction in pigs using Gd-DTPA-labeled dextran.

Myocardial infarctions were induced in 12 pigs. In 6 pigs, dextran-(Gd-DTPA)15 (approximately 0.1 mmol Gd/kg b.w.) was injected i.v. 4 to 4.5 hours after coronary artery occlusion. ECG gated MR images were obtained repeatedly before (n = 4) and after (n = 6) contrast medium injection. Relaxation times in blood samples were measured repeatedly. The animals were sacrificed 2 hours after contrast medium administration. The hearts were excised, reexamined in the MR equipment and stained with triphenyltetrazolium chloride (TTC) in order to define areas of infarction. The remaining 6 pigs were sacrificed 6 hours after occlusion without administration of contrast medium. These hearts were only imaged ex vivo. In vivo, the infarctions could not be identified with or without dextran-(Gd-DTPA)15. Ex vivo, without contrast medium, the infarctions had an increased signal intensity, most pronounced in the T2-weighted images. Dextran-(Gd-DTPA)15 caused a prolonged, pronounced shortening of T1 and T2 in blood samples. The infarct demarcation improved in the T1-weighted images after injection of dextran-(Gd-DTPA)15, due to a moderate enhancement in normal myocardium and a stronger enhancement at the periphery of the infarctions, while the central parts of the infarctions were only weakly enhanced.

Animals↗
PubMed1977

[The treatment of sudden deafness and Menière's disease with papaverin and low molecular weight dextran (author's transl)].

This study is concerned with the mean hearing gain in 50 cases of sudden deafness and 40 cases of Menière's disease treated with different drugs and treated with Papaverin and low molecular weight dextran. The treatment of sudden deafness with Papaverin and low molecular dextran was more effective than different drugs. In cases of Menière's disease the treatment with different drugs was not effective, but Papaverin and low molecular dextran was significantly successful. Finally, it is concluded that treatment according to Spoendlin (1969) with Papaverin and low molecular dextran is superior to different drugs.

Deafness↗
PubMed1992

Analysis of intrinsic fibrinolysis in human plasma induced by dextran sulfate.

The analysis of normal human plasma by fibrin autography revealed four species of plasminogen activator (PA) activity related to tissue-type PA, factor XII, prekallikrein and urokinase-type PA (u-PA). The u-PA activity increased significantly by incubating plasma with dextran sulfate. This increase was coincident with both the cleavage of factor XII and the complex formation of activated factor XII with its plasma inhibitors, which were determined by immunoblotting procedure. The dextran sulfate-dependent activation of u-PA required both factor XII and prekallikrein, but did not require either plasminogen or factor XI. High molecular weight kininogen was required only at a low concentration of dextran sulfate. Thus the results indicate that the factor XII and prekallikrein-mediated activation of single chain u-PA (scu-PA) operates as a major pathway of scu-PA activation in whole plasma in contact with dextran sulfate.

Dextran Sulfate↗