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Sample records for low-molecular-weight heparin therapy

  1. Massive choroidal hemorrhage associated with low molecular weight heparin therapy.

    PubMed

    Neudorfer, M; Leibovitch, I; Goldstein, M; Loewenstein, A

    2002-04-01

    An 84-year-old woman with unstable angina pectoris was treated with subcutaneous enoxaparine (Clexane) for several days before presenting with severe pain and decreased vision in her left eye. The intraocular pressure was 70 mmHg, and fundus examination showed a pigmented choroidal lesion and associated choroidal and retinal detachment. Ultrasonography was consistent with choroidal hemorrhage, and she was diagnosed as having acute glaucoma secondary to massive subchoroidal hemorrhage. Medical control of the intraocular pressure resulted in a significant clinical improvement. Intraocular hemorrhage and angle-closure glaucoma are rare and previously unreported complications in patients treated with low molecular weight heparin. It is important to be aware of this ocular complication as these drugs are so often used. PMID:11943940

  2. Study of the Efficacy, Safety and Tolerability of Low-Molecular-Weight Heparin vs. Unfractionated Heparin as Bridging Therapy in Patients with Embolic Stroke due to Atrial Fibrillation

    PubMed Central

    Feiz, Farnia; Sedghi, Reyhane; Salehi, Alireza; Hatam, Nahid; Bahmei, Jamshid; Borhani-Haghighi, Afshin

    2016-01-01

    Background Anticoagulation with adjusted dose warfarin is a well-accepted treatment for the prevention of recurrent stroke in patients with atrial fibrillation. Meanwhile, using bridging therapy with heparin or heparinoids before warfarin for initiation of anticoagulation is a matter of debate. We compared safety, efficacy, and tolerability of low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) as a bridging method in patients with recent ischemic stroke due to atrial fibrillation. Method This study was a randomized single-blind controlled trial in patients with acute ischemic stroke due to atrial fibrillation who were eligible for receiving warfarin and were randomly treated with 60 milligrams (mg) of LMWH (enoxaparin) subcutaneously every 12 h, or 1000 units/h of continuous intravenous heparin. The primary efficacy endpoints were recurrence of new ischemic stroke, myocardial infarction and/or death. The primary safety endpoint was central nervous system and/or systemic bleeding. Results Seventy-four subjects were recruited. Baseline demographic and clinical characteristics of two groups were matched. Composite endpoint outcome of new ischemic stroke, myocardial infarction, and/or death in follow-up period was seen in 10 subjects (27.03%) in UFH group and in four subjects (10.81%) in LMWH group (p value: 0.136). All hemorrhages and symptomatic central nervous system (CNS) hemorrhages in follow-up period were in 7 (18.9%) and 4 (10.8%) patients in UFH group, in 5 (13.5%), and 3 (8.1%) patients in LMWH group (p values: 0.754 and 0.751), respectively. Drop out and major adverse-effects such as heparin-induced thrombocytopenia and drug hypersensitivity were not seen in any patient. Conclusion Enoxaparin can be a safe and efficient alternative for UFH as bridging therapy. PMID:27403222

  3. Diffuse alveolar hemorrhage associated with low molecular weight heparin

    PubMed Central

    Hayashi, Shinichi; Maruoka, Shuichiro; Nakagawa, Yoshiko; Takahashi, Noriaki; Hashimoto, Shu

    2013-01-01

    Diffuse alveolar hemorrhage (DAH) has a varied etiology, including anticoagulation drugs. There is conflicting evidence whether low molecular weight heparin (LMWH) has a low risk of bleeding complications compared to unfractionated heparin. We report here a case of DAH in a 74-year-old woman who was administered enoxaparin, a LMWH, after bilateral total knee arthroplasty. Although congestive heart failure after blood transfusion and fluid infusion could in part be associated with the bleeding, LMWH may be a major cause of DAH since the patient quickly recovered after its cessation. DAH should be of concern when acute respiratory failure with ground-glass shadow develops in both lungs during anticoagulation therapy with LMWH. PMID:25473525

  4. Strategies and outcomes of periprocedural bridging therapy with low-molecular-weight heparin in patients with mechanical heart valves.

    PubMed

    Schulman, Jacqueline M; Majeed, Ammar; Mattsson, Eva; Schulman, Sam; Holmström, Margareta; Ågren, Anna

    2015-11-01

    Patients with mechanical heart valves (MHV) undergoing invasive procedures often receive periprocedural bridging with low-molecular-weight heparin (LMWH). The bridging strategies used in real-life and the predictors for bleeding and thrombosis are not well studied. We retrospectively assessed patients with MHV that underwent invasive procedures requiring vitamin K antagonist interruption and LMWH bridging. Thromboembolic and bleeding events occurring up to 30 days after the procedures were recorded. Predictors of major bleeding events (MBEs) were analyzed with logistic regression. We evaluated 547 patients with MHV who underwent 275 procedures during a 6.5-year period. Bridging with LMWH was used in 185 procedures in a total of 117 patients. Combined pre- and post-operative bridging was the most frequently employed (63 %). Doses of LMWH were prophylactic in 96 (52 %) of the procedures and therapeutic in 89 (48 %). The procedure-related bleeding risk was evaluated as high in 70 (38 %) and low in 115 (62 %) of the procedures. There was a trend to more frequent use of prophylactic doses (61 %) in high-risk surgery, and more therapeutic doses (53 %) in low-risk ones. There were 36 bleeding episodes, 21 (11 % of procedures) of which were classified as MBEs, but there were no thromboembolic events. Most MBEs (n = 14; 67 %) occurred in surgeries with high bleeding risk. In the multivariate analysis, the bleeding risk of the surgery itself was the only independent predictor for MBEs. For patients with MHV receiving perioperative bridging with LMWH, the major predictor for MBE is the bleeding risk of the surgery. PMID:25868460

  5. The Effect of Low Molecular Weight Heparins on Fracture Healing

    PubMed Central

    Kapetanakis, Stylianos; Nastoulis, Evangelos; Demesticha, Theano; Demetriou, Thespis

    2015-01-01

    Venous Thromboembolism is a serious complication in the trauma patient. The most commonly studied and used anticoagulant treatment in prophylaxis of thrombosis is heparin. The prolonged use of unfractionated heparin has been connected with increased incidence of osteoporotic fractures. Low molecular-weight-heparins (LMWHs) have been the golden rule in antithrombotic therapy during the previous two decades as a way to overcome the major drawbacks of unfractioned heparin. However there are few studies reporting the effects of LMWHs on bone repair after fractures. This review presents the studies about the effects of LMWHs on bone biology (bone cells and bone metabolism) and underlying the mechanisms by which LMWHs may impair fracture healing process. The authors’ research based on literature concluded that there are no facts and statistics for the role of LMWHs on fracture healing process in humans and the main body of evidence of their role comes from in vitro and animal studies. Further large clinical studies designed to compare different types of LMWHs, in different dosages and in different patient or animal models are needed for exploring the effects of LMWHs on fracture healing process. PMID:26161162

  6. The Effect of Low Molecular Weight Heparins on Fracture Healing.

    PubMed

    Kapetanakis, Stylianos; Nastoulis, Evangelos; Demesticha, Theano; Demetriou, Thespis

    2015-01-01

    Venous Thromboembolism is a serious complication in the trauma patient. The most commonly studied and used anticoagulant treatment in prophylaxis of thrombosis is heparin. The prolonged use of unfractionated heparin has been connected with increased incidence of osteoporotic fractures. Low molecular-weight-heparins (LMWHs) have been the golden rule in antithrombotic therapy during the previous two decades as a way to overcome the major drawbacks of unfractioned heparin. However there are few studies reporting the effects of LMWHs on bone repair after fractures. This review presents the studies about the effects of LMWHs on bone biology (bone cells and bone metabolism) and underlying the mechanisms by which LMWHs may impair fracture healing process. The authors' research based on literature concluded that there are no facts and statistics for the role of LMWHs on fracture healing process in humans and the main body of evidence of their role comes from in vitro and animal studies. Further large clinical studies designed to compare different types of LMWHs, in different dosages and in different patient or animal models are needed for exploring the effects of LMWHs on fracture healing process. PMID:26161162

  7. Photochemical Preparation of a Novel Low Molecular Weight Heparin

    PubMed Central

    Higashi, Kyohei; Hosoyama, Saori; Ohno, Asami; Masuko, Sayaka; Yang, Bo; Sterner, Eric; Wang, Zhenyu; Linhardt, Robert J.; Toida, Toshihiko

    2011-01-01

    Commercial low molecular weight heparins (LMWHs) are prepared by several methods including peroxidative cleavage, nitrous acid cleavage, chemical ß-elimination, and enzymatic β-elimination. The disadvantages of these methods are that strong reaction conditions or harsh chemicals are used and these can result in decomposition or modification of saccharide units within the polysaccharide backbone. These side-reactions reduce product quality and yield. Here we show the partial photolysis of unfractionated heparin can be performed in distillated water using titanium dioxide (TiO2). TiO2 is a catalyst that can be easily removed by centrifugation or filtration after the photochemical reaction takes place, resulting in highly pure products. The anticoagulant activity of photodegraded LMWH (pLMWH) is comparable to the most common commercially available LMWHs (i.e., Enoxaparin and Dalteparin). 1H NMR spectra obtained show that pLMWH maintains the same core structure as unfractionated heparin. This photochemical reaction was investigated using liquid chromatography/mass spectrometry (LC/MS) and unlike other processes commonly used to prepare LMWHs, photochemically preparation affords polysaccharide chains of reduced length having both odd and even of saccharide residues. PMID:22205826

  8. Arterial indications for the low molecular weight heparins

    PubMed Central

    Ageno, Walter; Huisman, Menno V

    2001-01-01

    Antithrombotic treatment is of proven importance in patients with acute coronary syndromes. There is now accumulating evidence from several clinical trials in patients with unstable angina pectoris that the low molecular weight heparins (LMWHs) are at least as effective as unfractionated heparin. The LMWHs are easier to use, with the potential to facilitate long-term outpatient treatment. The results of the trials have actually failed to show any clear advantage, however, of the LMWHs over the standard antiplatelet treatment, despite the evidence of a sustained hypercoagulability. Potentially, the use of higher doses of LMWHs could improve the outcomes, but this is as yet unproven and could be associated with unacceptably increased risk of bleeding. During the acute phase of a stroke, aspirin is the first choice of antithrombotic drug because it reduces the risk of recurrent stroke. LMWH cannot be recommended as an antithrombotic agent for the acute treatment of stroke. Prophylactic use of low dose LMWH for the prevention of venous thromboembolism should be considered in every patient with a stroke. PMID:11806802

  9. Anti-heparanase activity of ultra-low-molecular-weight heparin produced by physicochemical depolymerization.

    PubMed

    Achour, Oussama; Poupard, Nicolas; Bridiau, Nicolas; Bordenave Juchereau, Stephanie; Sannier, Fredéric; Piot, Jean-Marie; Fruitier Arnaudin, Ingrid; Maugard, Thierry

    2016-01-01

    Heparanase is an endo-β-D-glucuronidase that plays an important role in cancer progression, in particular during tumor angiogenesis and metastasis. Inhibiting this enzyme is considered as one of the most promising approaches in cancer therapy. Heparin is a complex glycoaminoglycan known as a strong inhibitor of heparanase. It is primarily used in clinical practice for its anticoagulant activities, which may not be compatible with its use as anti-angiogenic agent. In this study, we described the production of ultra-low-molecular-weight heparins (ULMWH) by a physicochemical method that consists in a hydrogen peroxide-catalyzed radical hydrolysis assisted by ultrasonic waves. We assessed the structural characteristics, anticoagulant and anti-heparanase activities of the obtained heparin derivatives and compared them with three commercial low-molecular-weight heparins (LMWH), glycol-split non-anticoagulant heparins and heparins produced by enzymatic methods. ULMWH generated by the physicochemical method were characterized by high anti-heparanase and moderate anticoagulant activities. These heparin derivatives might be potential candidates for cancer therapy when a compromise is needed between anti-heparanase and anticoagulant activities. PMID:26453883

  10. Isolation of low-molecular-weight heparin/heparan sulfate from marine sources.

    PubMed

    Saravanan, Ramachandran

    2014-01-01

    The glycosaminoglycan (heparin and heparan sulfate) are polyanionic sulfated polysaccharides mostly recognized for its anticoagulant activity. In many countries, low-molecular-weight heparins have replaced the unfractionated heparin, owing to its high bioavailability, half-life, and less adverse effect. The low-molecular-weight heparins differ in mode of preparation (chemical or enzymatic synthesis and chromatography fractionations) and as a consequence in molecular weight distribution, chemical structure, and pharmacological activities. Bovine and porcine body parts are at present used for manufacturing of commercial heparins, and the appearance of mad cow disease and Creutzfeldt-Jakob disease in humans has limited the use of bovine heparin. Consequently, marine organisms come across the new resource for the production of low-molecular-weight heparin and heparan sulfate. The importance of this chapter suggests that the low-molecular-weight heparin and heparan sulfate from marine species could be alternative sources for commercial heparin. PMID:25081076

  11. The potential benefits of low-molecular-weight heparins in cancer patients

    PubMed Central

    2010-01-01

    Cancer patients are at increased risk of venous thromboembolism due to a range of factors directly related to their disease and its treatment. Given the high incidence of post-surgical venous thromboembolism in cancer patients and the poor outcomes associated with its development, thromboprophylaxis is warranted. A number of evidence-based guidelines delineate anticoagulation regimens for venous thromboembolism treatment, primary and secondary prophylaxis, and long-term anticoagulation in cancer patients. However, many give equal weight to several different drugs and do not make specific recommendations regarding duration of therapy. In terms of their efficacy and safety profiles, practicality of use, and cost-effectiveness the low-molecular-weight heparins are at least comparable to, and offer several advantages over, other available antithrombotics in cancer patients. In addition, data are emerging that the antithrombotics, and particularly low-molecular-weight heparins, may exert an antitumor effect which could contribute to improved survival in cancer patients when given for long-term prophylaxis. Such findings reinforce the importance of thromboprophylaxis with low-molecular-weight heparin in cancer patients. PMID:20074349

  12. Calciphylaxis associated with cholangiocarcinoma treated with low-molecular-weight heparin and vitamin K.

    PubMed

    Riegert-Johnson, D L; Kaur, J S; Pfeifer, E A

    2001-07-01

    Calciphylaxis is a rare disorder of small-vessel calcification and cutaneous infarction associated with chronic renal failure. Rare cases of calciphylaxis not associated with chronic renal failure have been reported with breast cancer, hyperparathyroidism, and alcoholic cirrhosis. To our knowledge, we report the first case of calciphylaxis without chronic renal failure associated with cholangiocarcinoma and the first attempt to treat calciphylaxis with vitamin K. A 56-year-old woman presented with necrotic leg ulceration. She was treated initially with low-molecular-weight heparin, with no effect. A coagulation work-up showed vitamin K deficiency. During vitamin K therapy, the patient had fulminant progression of the calciphylaxis. She died, and an autopsy showed metastatic cholangiocarcinoma. Thrombosis and protein C deficiency have been implicated in the pathophysiology of calciphylaxis. Functional protein C deficiency may be one of several factors contributing to the development of calciphylaxis. Vitamin K therapy was ineffective in our patient and may have been detrimental. PMID:11444409

  13. Biosimilars of low-molecular-weight heparin products: fostering competition or reducing 'biodiversity'?

    PubMed

    Harenberg, J; Cimminiello, C; Agnelli, G; Di Minno, G; Polo Friz, H; Prandoni, P; Scaglione, F

    2016-03-01

    The term 'biosimilars' is used to qualify products developed to be similar to an original biological drug. Biosimilars are much more complicated to develop than a generic version of small-molecule drugs and this is especially true for low-molecular-weight heparins (LMWHs). Evidence on the antithrombotic management of acute coronary syndromes (ACS) showed that the introduction into the market of biosimilars approved on the basis of simple biological criteria, without robust data from comparative clinical trials, may be hazardous. Moreover, the mixtures of LMWH polysaccharide chains, some immunoallergic properties and potential contamination during the extraction process raise safety concerns. As was the case for the biosimilar erythropoietin, there is the risk that only copies of the most commercially successful LMWHs will be marketed, thus jeopardizing the 'biodiversity' now ensured by the presence of several LMWHs, each with unique features that support the use of an individual LMWH as first-choice therapy in certain categories of patients. PMID:26711899

  14. Low-Molecular-Weight Heparin and Unfractionated Heparin Decrease Th-1, 2, and 17 Expressions

    PubMed Central

    Huang, Jing-Ning; Tsai, Ming-Chin; Fang, Shun-Lung; Chang, Margaret Dah-Tsyr; Wu, Yu-Rou; Tsai, Jaw-Ji; Fu, Lin-Shien; Lin, Heng-Kuei; Chen, Yi-Jun; Li, Tsai-Wei

    2014-01-01

    Background We evaluated the effects of T helper cell differentiation in a mite-allergic animal model treated with inhaled heparins of different molecular weight. Method BALB/c mice were divided into four groups: 1. Control, 2. Mite intratracheal (mIT), 3. Inhaled heparin (hIN), 4. Inhaled low-molecular-weight heparin (lmwhIN). Groups 2, 3, and 4 were sensitized twice with Der p allergen subcutaneously on day 1 and day 8. Der p allergen was administered intratracheally on day 15. Groups 3 and 4 were treated with heparin or low-molecular-weight (lmw) heparin intranasally from day 1 to 22. Splenocytes from sacrificed mice stimulated with 16 µg/ml of Der p were cultured for 72 hours. Supernatants of splenocyte were collected to analyze the effect of Interleukin (IL)17-A/F, Interferon(IFN)-γ, IL-4, IL-13, and IL-10. Serum was also collected for Der P-specific IgE level on day 23. Total RNA was extracted from spleen tissue for mRNA expression. Gene expression of Foxp3, IL-10 IFN-γ, GATA3, IL-5, and RORγt were analyzed. Results Both hIN and lmwhIN groups had lower serum IgE level than that of the mIT group (both p<0.0001). Both hIN and lmwhIN groups showed significantly decreased transcripts of GATA-3, IFN-γ, IL-5, and RORγt mRNA in their spleen. Regarding the supernatant of splenocyte culture stimulated with Der p, compared with the mIT group, there were significant decreases in IL-17A/F, IFN-γ, IL-4, IL-13, and IL-10 secretion in inhaled hIN and lmwhIN groups. Conclusions From this balb/c mice study, the analyses of mRNA and cytokines revealed that both intranasal heparin and lmw heparin treatment decreased the expression of Th1, Th2, and Th17 in spleen. The underlying mechanism(s) warrant further studies. PMID:25364825

  15. Low molecular weight protamine as nontoxic heparin/low molecular weight heparin antidote (III): preliminary in vivo evaluation of efficacy and toxicity using a canine model.

    PubMed

    Lee, L M; Chang, L C; Wrobleski, S; Wakefield, T W; Yang, V C

    2001-01-01

    Heparin employed in cardiovascular surgeries often leads to a high incidence of bleeding complications. Protamine employed in heparin reversal, however, can cause severe adverse reactions. In an attempt to address this clinical problem, we developed low molecular weight protamine (LMWP) as a potentially effective and less toxic heparin antagonist. A homogeneous 1880-d peptide fragment, termed LMWP-TDSP5 and containing the amino acid sequence of VSRRRRRRGGRRRR, was derived directly from protamine by enzymatic digestion of protamine with thermolysin. In vitro studies demonstrated that TDSP5 was capable of neutralizing various anticoagulant functions of both heparin and commercial low molecular weight heparin preparations. In addition, TDSP5 exhibited significantly reduced crossreactivity toward mouse sera containing antiprotamine antibodies. TDSP5 showed a decrease in its potential in activating the complement system. All of these findings suggested the possibility of markedly reduced protamine toxicity for TDSP5. In this article, we conducted preliminary in vivo studies to further demonstrate the feasibility and utility of using LMWP as a nontoxic clinical protamine substitute. Dogs were chosen as test animals because they were known to magnify the typical human response to protamine. By using a full spectra of biological and clinical assays for heparin, including the anti-IIa and anti-Xa chromogenic assays and the activated partial, thromboplastin time and TCT clotting assays, TDSP5 showed that it could completely neutralize all these different anticoagulant functions of heparin in dogs. Although administration of protamine in dogs produced a significant reduction in mean arterial blood pressure (-14.9 mm Hg) and elevation in pulmonary artery systolic pressure (+5.0 mm Hg), the use of TDSP5 in dogs did not elicit any statistically significant change in any of the variables measured. Furthermore, the use of LMWP also significantly reduced the protamine

  16. Low molecular weight heparin tinzaparin antagonizes cisplatin resistance of ovarian cancer cells.

    PubMed

    Pfankuchen, Daniel Bastian; Stölting, Daniel Philipp; Schlesinger, Martin; Royer, Hans-Dieter; Bendas, Gerd

    2015-09-15

    Low molecular weight heparin (LMWH) is routinely used for antithrombotic treatment of cancer patients. Preclinical- and clinical data suggest that LMWH has beneficial effects for cancer patients beyond the prevention of thrombosis, i.e. by inhibiting metastasis. It is, however, unclear whether heparin has an impact on the efficiency of chemotherapy in cancer patients. Here we show that a therapeutic dosage of LMWH tinzaparin reverses cisplatin resistance of A2780cis human ovarian cancer cells to the level of sensitive cells. This novel activity of tinzaparin is associated with intense transcriptional reprogramming. Our gene expression profiling experiments revealed that 3776 genes responded to tinzaparin treatment. For this reason tinzaparin has a complex impact on diverse biological processes. We discovered that tinzaparin inhibits the expression of genes that mediate cisplatin resistance of A2780cis cells. In contrast tinzaparin induced the expression of genes that antagonize drug resistance. This activity of tinzaparin is mediated by cell surface proteoglycans, since enzymatic cleavage of heparan sulfates prevented the reversal of cisplatin resistance. These data indicate that cell surface heparan sulfate proteoglycans play an important role for chemotherapy resistance. The results of this study shed a new light on LMWH application in cancer therapy and suggest tinzaparin as promising treatment option of ovarian cancer patients in combination with anticancer drugs. Future clinical trials are needed to validate these findings. PMID:26239805

  17. Low-molecular-weight heparins : mechanisms, trials, and role in contemporary interventional medicine.

    PubMed

    Canales, John F; Ferguson, James J

    2008-01-01

    The clinical spectrum of acute coronary syndromes (ACS) encompasses unstable angina, non-ST-elevation, and ST-elevation myocardial infarction (STEMI). Within an atherosclerotic plaque, disruption of the endothelium can lead to exposure of tissue factor, with platelet adhesion, activation and aggregation, along with activation of the coagulation cascade, culminating in thrombin formation and the development of a cross-linked fibrin clot at the site of injury. Therapy aimed at blocking thrombin formation is now an integral part of the current cardiovascular guidelines in the treatment of ACS. Although unfractionated heparin (UFH) has been the mainstay of antithrombin therapy in the past, it has numerous clinical and biochemical limitations, including substantial protein binding (leading to inconsistent bioavailability), a need for frequent monitoring and adjustment, unreliable and variable degrees of anticoagulation, significant platelet activation, risk of heparin-induced thrombocytopenia, and the inability to block clot bound thrombin. With all of these limitations of UFH, low-molecular-weight heparins (LMWHs) have emerged as attractive alternatives. This review discusses the mechanism of action of LMWHs, and summarizes available literature concerning the use of LMWHs in a variety of clinical settings. Included in this review is an analysis of both current and prior data showing LMWH is as effective as UFH in the conservative and invasive management of patients with ACS. As well, very recent data are evaluated showing the safety and efficacy of LMWHs used in patients transitioning to the cardiac catheterization laboratory, and in those patients undergoing elective or urgent percutaneous coronary intervention (PCI). We also appraise the literature, along with the very recent studies investigating the use of LMWHs as adjunctive therapy to fibrinolytics in patients with STEMI. Finally, we set forth real-world conclusions concerning the use of LMWHs in contemporary

  18. Comparison of Low-Molecular-Weight Heparins Prepared From Bovine Lung Heparin and Porcine Intestine Heparin.

    PubMed

    Guan, Yudong; Xu, Xiaohui; Liu, Xinyue; Sheng, Anran; Jin, Lan; Linhardt, Robert J; Chi, Lianli

    2016-06-01

    Currently porcine intestine is the only approved source for producing pharmaceutical heparin in most countries. Enoxaparin, prepared by benzylation and alkaline depolymerization from porcine intestine heparin, is prevalent in the anticoagulant drug market. It is predicted that porcine intestine heparin-derived enoxaparin (PIE) will encounter shortage, and expanding its production from heparins obtained from other animal tissues may, therefore, be inevitable. Bovine lung heparin is a potential alternative source for producing enoxaparin. Critical processing parameters for producing bovine lung heparin-derived enoxaparin (BLE) are discussed. Three batches of BLEs were prepared and their detailed structures were compared with PIEs using modern analytical techniques, including disaccharide composition, intact chain mapping by liquid chromatography-mass spectrometry and 2-dimensional nuclear magnetic resonance spectroscopy. The results suggested that the differences between PIEs and BLEs mainly result from N-acetylation differences derived from the parent heparins. In addition, bioactivities of BLEs were about 70% of PIEs based on anti-factor IIa and Xa chromogenic assays. We conclude that BLE has the potential to be developed as an analogue of PIE, although some challenges still remain. PMID:27238483

  19. Low molecular weight heparin restores antithrombin III activity from hyperglycemia induced alterations.

    PubMed

    Ceriello, A; Marchi, E; Palazzni, E; Quatraro, A; Giugliano, D

    1990-01-01

    Alteration of antithrombin III (ATIII) activity, glycemia level dependent, exists in diabetes mellitus. In this study the ability of a low molecular weight heparin (LMWH) (Fluxum, Alfa-Wassermann S.p.A., Bologna, Italy), as well as unfractioned héparin, to preserve ATIII activity from glucose-induced alterations, both in vitro and in vivo, is reported. The subcutaneous and intravenous LMWH and heparin administration increases basal depressed ATIII activity in diabetic patients. Heparin shows an equivalent effect on both anti-IIa and anti-Xa activity of ATIII, while LMWH is more effective in preserving the anti-Xa activity. Similarity, heparin preserves ATIII activity from hyperglycemia-induced alterations, during hyperglycemic clamp, and LMWH infusion is able to preserve a significant amount of anti-Xa activity from glucose-induced alterations. Since diabetic patients show a high incidence of thrombotic accidents, LMWH appears to be a promising innovation for the prevention of diabetic thrombophylia. PMID:2196192

  20. Reliable low-molecular-weight heparin reversal in a child undergoing emergency surgery: a case report.

    PubMed

    Botros, Mena M; Mahmoud, Mohamed A; Costandi, Andrew J

    2016-09-01

    Low-molecular-weight heparin neutralization using protamine alone can be unreliable, especially in cases of immediate reversal for emergency surgery. Here, we describe a unique case of a 17-month-old girl with a history of glioneuronal tumor and corresponding hydrocephalus status post debulking and ventriculoperitoneal shunt placement, who was placed on enoxaparin after the development of a sagittal sinus thrombosis. Patient presented for emergency craniectomy and evacuation of subdural bleed after a fall while on therapeutic dose of enoxaparin. Protamine and fresh frozen plasma were used in the patient's perioperative course providing a reliable reversal of enoxaparin. PMID:27555185

  1. Neuroprotective effects of ultra-low-molecular-weight heparin in vitro and vivo models of ischemic injury.

    PubMed

    Zhang, Zhi-guo; Lü, Tai-sheng; Yuan, Hong-ying

    2011-06-01

    This study was conducted to demonstrate ultra-low-molecular-weight heparin's neuroprotective effects on ischemic injury both in vivo and in vitro studies. In vitro, the effect of ultra-low-molecular-weight heparin was tested in cultured PC12 cells exposed to Earle's solution containing sodium dithionite, to identify its neuroprotection to PC12 cells damaged by oxygen-glucose deprivation (OGD). The cell injury was detected by the tetrazolium salt 3-(4,5-dimethyl-2-thiazolyl)-2,5 diphenyl-2H tetrazolium bromide (MTT) assay. In vivo, male Wistar rats with middle cerebral artery occlusion were evaluated for infarct volume followed by the treatment with ultra-low-molecular-weight heparin. The results in vitro showed that ultra-low-molecular-weight heparin significantly inhibited PC12 cells damage induced by OGD. Results in vivo showed that vein injection of Ultra-Low-molecular-weight heparin at doses of 0.5 and 1.0 mg/kg exerted significant neuroprotective effects on rats with focal cerebral ischemic injury by significantly reducing the infarct volume compared with the injury group. All the findings suggest that ultra-low-molecular-weight heparin might act as a neuroprotective agent useful in the treatment of cerebral ischemia. PMID:20608997

  2. Cost-effectiveness of low-molecular-weight heparin and unfractionated heparin in treatment of deep vein thrombosis

    PubMed Central

    Rodger, M; Bredeson, C; Wells, P S; Beck, J; Kearns, B; Huebsch, L B

    1998-01-01

    BACKGROUND: Acute deep vein thrombosis has traditionally been treated with unfractionated heparin (UFH), administered intravenously, but low-molecular-weight heparins (LMWH), administered subcutaneously, have recently become available. The authors sought to determine which therapy was more cost-effective for inpatient and outpatient treatment of deep vein thrombosis. METHODS: An incremental cost-effectiveness analysis based on a decision tree was performed for 4 treatment strategies for deep vein thrombosis. Rate of major hemorrhage while receiving heparin, rate of recurrence of venous thromboembolism 3 months after treatment and mortality rate 3 months after treatment were determined by meta-analysis. Costs for the UFH therapy were prospectively collected by a case-costing accounting system for 105 patients with deep vein thrombosis treated in fiscal year 1995/96. The costs for LMWH therapy were modelled, and cost-effectiveness was determined by decision analysis. RESULTS: Meta-analysis revealed a mean difference in risk of hemorrhage of -1.1% (95% confidence interval [CI] -2.4% to 0.3%), a mean difference in risk of recurrence of venous thromboembolism of -2.6% (95% CI -4.5% to -0.7%) and a mean difference in risk of death of -1.9% (95% CI -3.6% to -0.4%), all in favour of subcutaneous unmonitored administration of LMWH. The cost to treat one inpatient was $2993 for LMWH and $3048 for UFH. Even more would be saved if LMWH was delivered on an outpatient basis (cost of $1641 per patient). The cost-effectiveness analysis showed that LMWH in any treatment setting is more cost effective than UFH. A sensitivity analysis demonstrated the robustness of this conclusion. INTERPRETATION: Treatment of deep vein thrombosis with LMWH is more cost effective than treatment with UFH in both inpatient and outpatient settings. PMID:9834718

  3. A short course of low-molecular-weight heparin to prevent deep venous thrombosis after elective total hip replacement

    PubMed Central

    Gallay, Steve; Waddell, James P.; Cardella, Piera; Morton, Jane

    1997-01-01

    Objective To determine the efficacy of a short course of low-molecular-weight heparin (enoxaparin) in the prevention of deep venous thrombosis and pulmonary embolism after elective total hip replacement. Design A prospective cohort study. Follow-up was a minimum of 3 months. Setting An acute-care hospital with a large-volume practice of elective total joint replacement. Patients A prospective group of 150 patients who required primary total hip arthroplasty and a historic control group of 150 patients. All patients were treated with compression stockings, indomethacin and early mobilization. The treatment group received low-molecular-weight heparin, 30 mg every 12 hours for 5 days postoperatively; the control group received no specific anticoagulant therapy. Interventions Total hip replacement. Doppler venography on postoperative day 5 and 2 to 5 days later if required. Main outcome measures Presence or absence of deep venous thrombosis. Wound hemorrhage, transfusion rate, number of units of blood transfused and changes in the hemoglobin level. Results The incidence of proximal deep venous thrombosis (popliteal vein to common iliac vein) was 0% in the treatment group versus 4% in the control group. There was no difference in bleeding or number of transfusions required. There was, however, a significant (p = 0.005) drop in hemoglobin level in the treatment group. Conclusions A short course of low-molecular-weight heparin provides effective protection against proximal deep venous thrombosis without significantly increasing the risk to the patient. The treatment is compatible with early patient discharge and the pharmacologic prevention of heterotopic ossification after total joint replacement. PMID:9126125

  4. Cancer-associated thrombosis, low-molecular-weight heparin, and the patient experience: a qualitative study

    PubMed Central

    Seaman, Siwan; Nelson, Annmarie; Noble, Simon

    2014-01-01

    Background Venous thromboembolism is a common complication of cancer and its treatments. Treatment of cancer-associated thrombosis (CAT) differs from treatment of thrombosis in noncancer patients, requiring a daily injection of low-molecular-weight heparin (LMWH) for 6 months instead of an oral anticoagulant. Previous research suggested LMWH is an acceptable intervention in the treatment of CAT, yet clinical practice and therapeutic opportunities have changed in the decade since the study was conducted. Furthermore, in the previous study there was acknowledged selection bias in participant recruitment. There is increasing clinical use of the novel oral anticoagulants, although their efficacy and safety is yet to be demonstrated within the cancer population. The experience of patients receiving anticoagulation for CAT will inform future practice with respect to quality of life and adherence to anticoagulation therapy. Aim To explore the acceptability of long-term LMWH for the treatment of CAT in the contexts of living with cancer and quality of life. Design Qualitative study of cancer patients who had been receiving LMWH for at least 3 months for CAT was undertaken. Audiotaped semistructured interviews were conducted and transcribed. Thematic analysis was undertaken until theoretical saturation. Setting/participants Fourteen patients attending a palliative care or CAT clinic were interviewed. Participants had been receiving LMWH for a median 6 months. Results Participants reported distressing symptoms associated with symptomatic CAT, which they rated as worse than their cancer experiences. LMWH was considered an acceptable intervention despite challenges of long-term injections. Several adaptive techniques were reported to optimize ongoing injections. Participants would only favor a novel oral anticoagulant if it was equivalent to LMWH in efficacy and safety. Conclusion Although LMWH remains an acceptable intervention for the treatment of CAT, its long-term use is

  5. Low molecular weight heparin for the treatment of retinal vein occlusion: a systematic review and meta-analysis of randomized trials

    PubMed Central

    Lazo-Langner, Alejandro; Hawel, Jeff; Ageno, Walter; Kovacs, Michael J.

    2010-01-01

    Retinal vein occlusion is a frequent cause of visual loss for which few effective therapies are available. Anticoagulation with low molecular weight heparin might be of value in its treatment. We conducted a systematic review and meta analysis of randomized trials evaluating the effect of low molecular weight heparin in patients with retinal vein occlusion. Data sources included MEDLINE, EMBASE, HealthSTAR, the Cochrane Library, Lilacs, the Investigative Ophthalmology and Visual Science database and gray literature. Main outcome was the mean difference between the visual acuity measured at baseline and at six months expressed in the logMAR scale. Secondary outcome was a composite of any adverse ocular outcome including: worsening of visual acuity, visual fields or fluorescein angiography, or development of iris neovascularization, any neovascularization or neovascular glaucoma. Subgroup analyses for branch versus central retinal vein occlusion were conducted. We identified 1,084 references of which 3 studies comparing low molecular weight heparin with aspirin (229 evaluable patients) were included. Overall, the pooled mean visual acuity difference was −0.23 logMAR (95% CI −0.38, −0.09; P=0.002) in favor of low molecular weight heparin. Low molecular weight heparin was associated with a 78% risk reduction for developing any adverse ocular outcome (pooled RR 0.22; 95% CI 0.10, 0.46; P<0.001). In subgroup analyses benefits seemed lower in branch retinal vein occlusion. No increased vitreous hemorrhages were observed. In patients with retinal vein occlusion treatment with low molecular weight heparin seems to be associated with improvement in the visual acuity and less adverse ocular outcomes. These benefits might differ in patients with central as opposed to branch retinal vein occlusion. Further studies are required to confirm these findings and clarify its benefits in specific subgroups of patients before definitive recommendations can be made. PMID:20305141

  6. Low-molecular-weight heparins in the treatment of venous thromboembolism

    PubMed Central

    Ageno , Walter; Huisman, Menno V

    2000-01-01

    Venous thromboembolism is a common disease that is associated with considerable morbidity if left untreated. Recently, low-molecular-weight heparins (LMWHs) have been evaluated for use in acute treatment of deep venous thrombosis and pulmonary embolism. Randomized studies have shown that LMWHs are as effective as unfractionated heparin in the prevention of recurrent venous thromboembolism, and are as safe with respect to the occurrence of major bleeding. A pooled analysis did not show substantial differences among different LMWH compounds used, but no direct comparison of the different LMWHs is currently available. Finally, in patients with pulmonary embolism, there is a relative lack of large studies of daily practice. It could be argued that large prospective studies, in patients who were treated with LMWHs from the moment of diagnosis, are needed. PMID:11714421

  7. [Anticoagulant activity of low-molecular-weight heparins obtained using a hydrolase complex].

    PubMed

    Drozd, N N; Tolstenkov, A S; Bannikova, G E; Miftakhova, N T; Lapikova, E S; Makarov, V A; Varlamov, V P

    2007-01-01

    The anticoagulant activity of low-molecular weight heparins (LMWH-PC) with average distribution of molecular weights within 3.4-5.8 kD was investigated. The samples of LMWH-PC were obtained from unfractionated heparin using immobilized enzyme complex of protease C. The LMWH-PC derivatives inhibited the activity of blood coagulation factors IIa (thrombin) and Xa. The LMWH-PC derivatives had an anti-factor-Xa activity up to 131-208 IU/mg and anti-factor-IIa activity up to 81-175 IU/mg. All LMWH-PC derivatives form complexes with protamine sulfate during electrophoresis in agarose gel. The anticoagulant activity of rabbit plasma exhibits a doze-dependent increase upon the intravenous or subcutaneous injection of LMWH-PC with a molecular weight of 5.4 kD. PMID:18318190

  8. Comprehensive Identification and Quantitation of Basic Building Blocks for Low-Molecular Weight Heparin.

    PubMed

    Sun, Xiaojun; Sheng, Anran; Liu, Xinyue; Shi, Feng; Jin, Lan; Xie, Shaoshuai; Zhang, Fuming; Linhardt, Robert J; Chi, Lianli

    2016-08-01

    Low-molecular weight heparins (LMWHs) are widely used anticoagulant drugs. They inherit the heterogeneous backbone sequences of the parent heparin, while the chemical depolymerization process modifies the nonreducing end (NRE) and reducing end (RE) of their sugar chains. Some side reactions may also occur and increase the structural complexity of LMWHs. It is important to precisely characterize the structures of LMWHs, especially their chemical modifications, to ensure drug quality and safety. Compositional analysis provides a powerful approach to reveal the building blocks that make up the LMWHs, which are the mutual consequence of the heparin starting materials and the manufacturing process. Here, we introduce a comprehensive analytical method to recover the most basic building blocks of LMWHs. A strategy of combining both enzymatic digestion and oxidative degradation of LMWH was used to make the NRE, RE, and backbone structures differentiable from one another. Satisfactory separation, identification, and quantitation were achieved by coupling hydrophilic interaction chromatography with a triple quadrupole mass spectrometer operating under the multiple reaction monitoring mode. After enzymatic digestion, over 30 species were detected, with both natural and chemically modified heparin basic building blocks. Two novel structures, including a trisaccharide containing two glucosamine residues and a tetrasaccharide containing a 3-O-sulfated uronic acid residue, were discovered. Reduced and oxidatively degraded samples were analyzed to provide the complementary information on both termini of LMWHs. The reproducibility of this method was evaluated, and enoxaparin injections were analyzed to demonstrate the application of this method for evaluating the sameness of LMWH products. PMID:27388010

  9. Low molecular weight heparin gels, based on nanoparticles, for topical delivery.

    PubMed

    Loira-Pastoriza, C; Sapin-Minet, A; Diab, R; Grossiord, J L; Maincent, P

    2012-04-15

    A commercial suspension of nanoparticles (Eudragit RS 30D) was used to manufacture a gel for topical application. Gels were prepared by mixing a polycationic polymer (Eudragit(®) RS 30D) and a low molecular weight heparin (LMWH), an antithrombotic agent. Gels formed spontaneously at a ratio of 1:1 as a result of electrostatic interactions between the polyanionic drug and the polycationic polymer. Different types of heparin were used: Bemiparin, Enoxaparin (Lovenox), Nadroparin (Fraxiparin) and Tinzaparin (Innohep). Several LMWH concentrations were tested. Rheological measurements were performed to investigate the gel behavior. Gel formation was confirmed by dynamic rheological measurements as the elastic modulus (G') was higher than the viscous one (G″). The amount of heparin incorporated into the gel matrix was determined. A maximum of incorporation (100%) was reached using a heparin solution of 600 IU/mL. The release kinetics of LMWH from the gel were also studied. Regardless of the LMWH used in the formulation, a biphasic release profile was observed. Accordingly, a burst effect was observed. Afterwards, the release rate became steady. The penetration of the LMWH through the dermal barrier was also investigated. PMID:22310458

  10. The Anti-Factor Xa Range For Low Molecular Weight Heparin Thromboprophylaxis

    PubMed Central

    Ward, Salena M.

    2015-01-01

    Low molecular weight heparins (LMWHs) are now the mainstay option in the prevention and treatment of venous thromboembolism. In some patients receiving therapeutic doses of LMWH, activity can be measured by quantifying the presence of Anti-factor Xa (AFXa) for dose adjustment. However, currently there are no guidelines for LMWH monitoring in patients on thromboprophylactic, doses, despite certain patient populations may be at risk of suboptimal dosing. This review found that while the AFXa ranges for therapeutic levels of LMWHs are relatively well defined in the literature, prophylactic ranges are much less clear, thus making it difficult to interpret current research data. From the studies published to date, we concluded that a reasonable AFXa target range for LMWH deep venous thromboses prophylaxis might be 0.2-0.5 IU/mL. PMID:26733269

  11. Hydrothermal synthesis of hydroxyapatite plates prepared using low molecular weight heparin (LMWH).

    PubMed

    Rajeswari, A; Kumar, V Ganesh; Karthick, V; Dhas, T Stalin; Potluri, Sri Lakshmi

    2013-11-01

    Materials with enhanced physical and biological properties have been used for biomedical applications and can be developed by functionalizing them using various components. Hydroxyapatite (HAP), among other available synthetic material, serves as one of the best tools in orthopaedics and ceramic coatings. The porous structure of HAP helps in bone cell regeneration, chemical integration of bone and also favours the interaction between bone and tissues. Herein, we have demonstrated a simple procedure for the synthesis of HAP using low molecular weight heparin (LMWH), a structural analogue of bone heparan sulphate proteoglycan. The presence of small sized HAP plates with well-defined structures was revealed using electron microscopic analysis. The phase purity of the synthesized HAP was evaluated using X-ray diffraction pattern obtained before and after immersion in simulated body fluid (SBF). PMID:23871522

  12. Intentional low-molecular-weight heparin overdose: a case report and review.

    PubMed

    Byrne, Michael; Zumberg, Marc

    2012-12-01

    The reversal of low-molecular-weight heparins, particularly at supratherapeutic levels, remains challenging. The paucity of literature available to guide the treatment of these patients makes their management difficult for primary care providers, surgeons, and subspecialists alike. We report the case of a 34-year-old woman, who intentionally overdosed on enoxaparin (Lovenox) in a suicide attempt. Her initial antifactor Xa activity level was 8.3 IU/ml, the highest level reported in the literature to date. She was initially managed conservatively, however, within 24 h of admission she developed evidence of acute blood loss. Protamine sulfate and three doses of recombinant activated factor VII (rFVIIa) were administered in an effort to control bleeding. We report the effects of these measures and review the literature to date. Our study is one of the first to graph in-vivo antifactor Xa activity levels and to suggest a drug half-life of approximately 25 h. PMID:23135382

  13. Postoperative Suprachoroidal Hemorrhage in a Glaucoma Patient on Low Molecular Weight Heparin

    PubMed Central

    AlHarkan, Dora H.; AlJadaan, Ibrahim A.

    2013-01-01

    Suprachoroidal hemorrhage is a complication associated with intraocular surgery that can occur both intraoperatively and postoperatively. Several intraoperative or postoperative risk factors have been indentified. The use of low-molecular weight heparin (LMWH) is considered one of the risk factors in surgical cases (ocular or non ocular) and non-surgical cases. Here we present a case of suprachoroidal hemorrhage in a glaucoma patient that occurred after preoperative prophylactic LMWH for deep venous thrombosis. The use of LMWH has been reported to cause suprachoroidal hemorrhage even in patients without any risk factors. The use of LMWH continues to increase, hence it is important to be aware of the possibility of suprachoroidal hemorrhage and to determine the risk/benefit ratio, especially in patients with other risk factors. PMID:23741139

  14. EXPERIMENTAL POST THROMBOSIS VEIN WALL RE-ENDOTHELIALIZATION IS MODULATED BY LOW MOLECULAR WEIGHT HEPARIN

    PubMed Central

    Moaveni, Daria K.; Lynch, Erin M.; Luke, Cathy; Sood, Vikram; Upchurch, Gilbert R.; Wakefield, Thomas W.; Henke, Peter K.

    2008-01-01

    Objective Vein wall endothelial turnover after stasis deep vein thrombosis (DVT) has not been well characterized. The purpose of this study was to quantify post DVT re-endothelialization, and hypothesized that low molecular weight heparin (LMWH) therapy would positively affect this process. Methods Stasis DVT was generated in the rat by inferior vena cava (IVC) ligation, with harvest at 1, 4, and 14 days. Immunohistological quantification of vascular smooth muscle cells (VSMC) and luminal endothelialization was estimated by alpha SMA (aSMA) and von Willebrand Factor (vWF) positive staining, respectively. In separate experiments, rats were treated either pre or post-DVT with LMWH (3mg/kg daily, SubQ) until harvesting at 4 and 14 days. The IVC was processed for histological analysis, or after gently removing the thrombus, processed for organ culture. In vitro stimulation of the vein wall with IL-1β (1ng/ml) was done, and the supernatant processed at 48 hours for nitric oxide (NO). Cells were processed by real time PCR for eNOS, iNOS, COX-1, COX-2 and thrombomodulin (TM) at 4 and 14 days, and collagen I and III at 14 days. Comparisons were done with ANOVA or t-test. A P<.05 was significant. Results Thrombus size peaked at 4 days while luminal re-endothelialization increased over time (1d: 11±2%, 4d: 23±4%, 14d: 64±7% (+) vWF staining; P<.01, N = 3−4, compared with non DVT control). Similarly, VSMC staining was lowest at day 1, and gradually returned to baseline by 14 days. Both pre and post DVT LMWH significantly increased luminal re-endothelialization, without a difference in thrombus size at 4 days, but no significant difference was noted at 14 days despite smaller thrombi with LMWH treatment. Pretreatment of LMWH was associated with increased VSMC area, and recovery of certain inducible endothelial specific genes. No significant difference in NO levels in the supernatant was found at 4 days. At 14 days, type III collagen was significantly elevated with LMWH

  15. Administration of low molecular weight and unfractionated heparin during percutaneous coronary intervention.

    PubMed

    Ali-Hassan-Sayegh, Sadegh; Mirhosseini, Seyed Jalil; Shahidzadeh, Azadeh; Mahdavi, Parisa; Tahernejad, Mahbube; Haddad, Fatemeh; Lotfaliani, Mohammad Reza; Sabashnikov, Anton; Popov, Aron-Frederik

    2016-01-01

    This systematic review with meta-analysis sought to determine the efficacy and safety of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) on clinical outcomes following percutaneous coronary intervention. Medline, Embase, Elsevier, and web of knowledge as well as Google scholar literature were used for selecting appropriate studies with randomized controlled design. After screening 445 studies, a total of 23 trials (including a total of 43,912 patients) were identified that reported outcomes. Pooled analysis revealed that LMWH compared to UFH could significantly increase thrombolysis in myocardial infarction grade 3 flow (p<0.001), which was associated with similar target vessel revascularization (p=0.6), similar incidence of stroke (p=0.7), and significantly lower incidence of re-myocardial infarction (p<0.001), major bleeding (p=0.02) and mortality (p<0.001). Overall, LMWH was shown to be a useful type of heparin for patients with MI undergoing PCI, due to its higher efficacy and lower rate of complication compared to UFH. It is also associated with increased myocardial perfusion, decreased major hemorrhage, and mortality. PMID:27133344

  16. Preparation and evaluation a new generation of low molecular weight heparin.

    PubMed

    Zhao, Dan; Sang, Qing; Cui, Huifei

    2016-04-01

    Enoxaparin is widely used in clinic, but it has some disadvantages. For example, its anticoagulant activity is weaker compared with heparin and it can not be effectively neutralizad by protamine sulfate (PS) in case of bleeding. Therefore, in this work, a new generation of low molecular weight heparin (NG-LMWH) was prepared.The NG-LMWH was prepared with the method of alkaline β-elimination followed by gel chromatography. Estimating the molecular weight of the NG-LMWH by GPC-HPLC, it has a remarkably low polydispersity index and narrow molecular weight distribution. The polydispersity index of NG-LMWH was 1.052, which was lower than heparin (1.5) and enoxaparin (1.279). Anti-FXa and anti-FIIa potency of NG-LMWH was much higher than that of Enoxaparin, and close to that of heparin, which was determined by chromogenic substrate method. To test the degree of anti-FXa or anti-FIIa potency neutralized by PS, equivalent anti-FXa or anti-FIIa activity doses of different anticoagulant in plasma were titrated with increasing amounts of PS in plasma. The results indicate that NG-LMWH was more efficiently neutralized by PS than enoxaparin.The efficacy of anti-thrombus of NG-LMWH was superior to enoxaparin and the effect was dose dependent, which was evaluated with rat carotid artery thrombosis and inferior vena cava thrombosis model. The results of pharmacokinetics in New Zealand rabbits showed that the pharmacokinetic characteristics of NG-LMWH were similar to enoxaparin. The NG-LMWH prepared in this work has both advantages of heparin and enoxaparin with more effective and safer anticoagulation than enoxaparin. PMID:27044828

  17. [Treatment and prophylaxis of deep venous thrombosis with low molecular weight heparins (meta-analysis of clinical trials)].

    PubMed

    Valiukiene, Laimute; Naudziūnas, Albinas; Unikauskas, Alvydas

    2003-01-01

    Deep-vein thrombosis is a relevant problem of today's medicine, because the risk to fall ill with this pathology is 2-5%; it increases in senior age. Direct and indirect acting thrombin inhibitors are used for treatment and prevention of vein thrombosis. Though great efficiency and safety of new anticoagulants (especially factor Xa inhibitors) were proven in clinical studies, unfractionated heparin and low molecular weight heparins are still most widely used in clinical practice. Low molecular weight heparins are obtained by depolymerizing heparin: its molecular weight is being decreased to 3-7 kDa, or 18-20 monosaccharides. Low molecular weight heparins strongly inhibit Xa coagulation factor and faintly - IIa, that's why their anti-Xa/anti-IIa proportion is >1 (unfractionated heparin = 1); enoxaparine and nadroparine show up the highest proportion. The low weight of these heparins determines good pharmacodynamic characteristics: excellent assimilation from subcutaneous layer, long circulation in plasma, infrequent side effects. Due to these characteristics they are convenient, safe and economically worth using (used by subcutaneous injections, prescribed only 1-2 times per day, coagulation control not required, possibility for patient to be treated at home); therefore low molecular weight heparins are more and more often used in treatment of deep-vein thrombosis and also in primary and secondary prevention. They are one of the most efficacious contemporary anticoagulants, which allow to decrease the deep-vein thrombosis treatment and prevention costs. This article presents literature review about low molecular weight heparins, their appliance in treatment and prophylaxis of deep-vein thrombosis. PMID:12738903

  18. Market entry of biosimilar low-molecular-weight heparins in Europe: opportunities and challenges.

    PubMed

    Simoens, Steven; Huys, Isabelle

    2013-04-01

    This article examines the market entry of biosimilar low-molecular-weight heparins (LMWHs) in Europe by focusing on regulatory requirements, pricing, reimbursement, prescribing, and dispensing. The window for biosimilar LMWHs to enter the market is narrow on the supply side because of several factors. These include (1) regulatory requirements, including a quality dossier, clinical and nonclinical studies, pharmacodynamic and pharmacokinetic studies, immunogenicity studies, and a comparability exercise (but a reduction in clinical data requirements might be plausible in some cases); (2) prices of originator LMWHs are lower than those of other biologic products; (3) European prices of originator LMWHs are lower than those observed in the rest of the world; (4) research and development and manufacturing costs are substantial; (5) costs of active pharmaceutical ingredients have increased following the heparin contamination crisis; and (6) biosimilar LMWHs may be subjected to generic medicine pricing regulations. Furthermore, there are limited opportunities for biosimilar LMWHs on the demand side. This is because, although LMWHs have a large market volume in Europe, demand-side incentives for biosimilar LMWHs are largely absent, and the questions about interchangeability and substitution between originator and biosimilar LMWHs have yet to be fully resolved. PMID:23235959

  19. Preparation of Low Molecular Weight Heparin by Microwave Discharge Electrodeless Lamp/TiO2 Photo-Catalytic Reaction.

    PubMed

    Lee, Do-Jin; Kim, Byung Hoon; Kim, Sun-Jae; Kim, Jung-Sik; Lee, Heon; Jung, Sang-Chul

    2015-01-01

    An MDEL/TiO2 photo-catalyst hybrid system was applied, for the first time, for the production of low molecular weight heparin. The molecular weight of produed heparin decreased with increasing microwave intensity and treatment time. The abscission of the chemical bonds between the constituents of heparin by photo-catalytic reaction did not alter the characteristics of heparin. Formation of by-products due to side reaction was not observed. It is suggested that heparin was depolymerized by active oxygen radicals produced during the MDEL/TiO2 photo-chemical reaction. PMID:26328426

  20. Outcomes in Women Receiving Low-Molecular Weight Heparin During Pregnancy

    PubMed Central

    Desancho, Maria T.; Khalid, Sana; Christos, Paul J.

    2014-01-01

    Objective To assess the rate and type of maternal and infant complications among pregnant women receiving low-molecular-weight heparin (LMWH). Study Design Retrospective study of pregnant women on LMWH referred to two university hematology clinics from January 2001 to December 2010. We recorded the number of pregnancies, indication, dose and dose adjustments for LMWH, pregnancy outcomes (live births, maternal and infant complications) and side effects of LMWH. Results There were 89 pregnancies in 76 women. The most common indication for LMWH was a history of adverse outcome of pregnancy associated with thrombophilia. LMWH was adjusted in 75% and 45% of pregnancies in women on therapeutic and prophylactic doses, respectively. Live birth rate was 97%. There were 25 maternal and 11 infant complications. Side effects were minimal and included decreased bone mineral density and bleeding. Conclusion LMWH use among pregnant women is associated with successful pregnancy outcomes. While side effects were minimal, maternal and infant complications occurred in 28% and 12% of cases, respectively. PMID:22964770

  1. Thromboprophylaxis with low-molecular-weight heparins: an assessment of the methodological quality of studies.

    PubMed

    Agnelli, Giancarlo; Prandoni, Paolo; Di Minno, Giovanni; Cimminiello, Claudio; Scaglione, Francesco; Boracchi, Patrizia; Molteni, Mauro; Polo Friz, Hernan; Di Minno, Matteo Nicola Dario; Marano, Giuseppe

    2015-03-01

    Low-molecular-weight heparin (LMWH) represents the standard of care for prophylaxis of venous thromboembolism (VTE). We conducted a review of the evidence supporting the use of the different LMWHs employed in VTE prophylaxis, in different clinical settings, and analyzed its progression over time. To evaluate the standards of methodological quality of studies, we elaborated a quality assessment tool. By electronic databases, PubMed, MEDLINE, and Scopus databases, 249 articles deemed eligible for the analysis were selected. Several LMWHs did not have publications in all clinical settings. Extended duration of prophylaxis was documented only for a few LMWH. The quality score yielded statistically significant differences between the medians of the four settings (p = 0.0021) with a higher score in major orthopedic surgery (median, 16; 95% confidence interval [CI], 15-16) when compared with general surgery (median, 14; 95% CI, 13-14; p < 0.001). Median score for studies published after the year 1990 was higher than for those published earlier (p < 0.001). We conclude that the quality of the studies supporting LMWH for VTE prophylaxis in the different clinical settings is not homogeneous and inferior for studies performed before the year 1990. Clinical interchangeability of LMWHs in clinical practice remains a critical issue, and the selection of a product should be based on evidence available for each agent, and for each clinical indication derived from clinical trials. PMID:25703242

  2. Development of subcutaneous sustained release nanoparticles encapsulating low molecular weight heparin

    PubMed Central

    Jogala, Satheesh; Rachamalla, Shyam Sunder; Aukunuru, Jithan

    2015-01-01

    The objective of the present research work was to prepare and evaluate sustained release subcutaneous (s.c.) nanoparticles of low molecular weight heparin (LMWH). The nanoparticles were prepared by water–in-oil in-water (w/o/w) emulsion and evaporation method using different grades of polylactide co-glycolide (50:50, 85:15), and different concentrations of polyvinyl alcohol (0.1%, 0.5%, 1%) aqueous solution as surfactant. The fabricated nanoparticles were evaluated for size, shape, zeta potential, encapsulation efficiency, in vitro drug release, and in vivo biological activity (anti-factor Xa activity) using the standard kit. The drug and excipient compatibility was analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. The formation of nanoparticles was confirmed by scanning electron microscopy; nanoparticles were spherical in shape. The size of prepared nanoparticles was found between 195 nm and 251 nm. The encapsulation efficiency of the nanoparticles was found between 46% and 70%. In vitro drug, release was about 16–38% for 10 days. In vivo drug, release shows the sustained release of drug for 10 days in rats. FTIR studies indicated that there was no loss in chemical integrity of the drug upon fabrication into nanoparticles. DSC and XRD results demonstrated that the drug was changed from the crystalline form to the amorphous form in the formulation during the fabrication process. The results of this study revealed that the s.c. nanoparticles were suitable candidates for sustained delivery of LMWH. PMID:25878975

  3. Preparation and evaluation of a novel oral delivery system for low molecular weight heparin

    PubMed Central

    Lavanya, Nallaguntla; Muzib, Yallamalli Indira; Aukunuru, Jithan; Balekari, Umamahesh

    2016-01-01

    Objective: The objective of the present work was to prepare and evaluate a novel oral formulation for systemic delivery of low molecular weight heparin (LMWH). The formulation consisted of Eudragit S 100-coated positively charged liposomes encapsulating LMWH and a penetration enhancer. Materials and Methods: Positively charged liposomes were first prepared by the thin film hydration method using lipid (soy phosphotidylcholine and cholesterol) and stearyl amine (SA) in the optimum ratio of 16:1, along with cetylpyridinium chloride (CPC) as a penetration enhancer. Prepared liposomes were coated with negatively charged Eudragit S 100 (0.3% w/v). The formulations were studied for various in vitro and in vivo properties. Differential scanning calorimetry (DSC), x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) studies, and in vitro drug release were used for in vitro characterization of the formulations. Ex vivo permeation studies were performed by using distal small intestine of rat. Oral absorption studies were conducted with the rat model. Results: Coating of the liposomes was confirmed by SEM and particle size determination studies. In vitro release studies of coated liposomes have demonstrated that the release of LMWH was in the following order: Stomach < small intestine < distal small intestine < colon. Ex vivo permeation studies have shown a fivefold increase in permeation of LMWH with Eudragit S 100-coated liposomes compared to uncoated, uncharged liposomes. Oral absorption studies have showed that with Eudragit-coated liposomes, the oral bioavailability of LMWH was improved, compared to plain LMWH solution. This is revealed by a threefold increase in the area under the curve (AUC) of the plasma concentration time curve. Conclusion: A novel formulation for oral delivery of LMWH was thus successfully prepared and evaluated. PMID:27606258

  4. Preclinical safety evaluation of low molecular weight heparin-deoxycholate conjugates as an oral anticoagulant.

    PubMed

    Kim, Ji-young; Jeon, Ok-Cheol; Moon, Hyun Tae; Hwang, Seung Rim; Byun, Youngro

    2016-01-01

    The preclinical safety of a newly developed oral anticoagulant, the low molecular weight heparin-deoxycholate conjugate (OH09208), was evaluated by a comprehensive evaluating program in compliance with standard guidelines. The single dose oral toxicity study in rats receiving 2000 and 5000 mg kg(-1) of OH09208 did not reveal any mortality, unusual body weight changes or necropsy findings. The results of the 4-week oral toxicity study with a 4-week recovery program in rats receiving OH09208 in doses of 100, 300 and 1000 mg kg(-1) day(-1) did not reveal any mortality, or indicate any unusual clinical signs, or show any toxicokinetic relationships to the administration of OH09208. Although the increase in liver enzymes in one male dog treated with 300 mg kg(-1) day(-1) and one female dog treated with 1000 mg kg(-1) day(-1) could not be excluded from the effect of the test substance, no other toxicologically significant changes were observed in the 4-week oral toxicity study with a 4-week recovery in beagle dogs. Thus, while the no-observed-adverse-effect level value from the 4-week study in both male and female rats was 1000 mg kg(-1) day(-1), those from the 4-week study in male and female beagle dogs were 300 and 1000 mg kg(-1) day(-1), respectively. Furthermore, OH09208 did not induce anaphylactic reactions in guinea pigs, micronucleated bone marrow cells in male ICR mice, chromosomal aberration in Chinese hamster lung cell lines, bacterial reverse mutation, and any abnormalities in hERG current assay, mouse central nervous system and dog cardiovascular studies. Overall, there were no unexpected toxicities in this preclinical study that might have precluded the safe administration of OH09208 to humans. PMID:25900269

  5. Measuring Anti–Factor Xa Activity to Monitor Low-Molecular-Weight Heparin in Obesity: A Critical Review

    PubMed Central

    Egan, Gregory; Ensom, Mary H H

    2015-01-01

    Background: The choice of whether to monitor anti–factor Xa (anti-Xa) activity in patients who are obese and who are receiving low-molecular-weight heparin (LMWH) therapy is controversial. To the authors’ knowledge, no systematic review of monitoring of anti-Xa activity in such patients has been published to date. Objective: To systematically ascertain the utility of monitoring anti-Xa concentrations for LMWH therapy in obese patients. Data Sources: MEDLINE (1946 to September 2014), the Cochrane Database of Systematic Reviews, Embase (1974 to September 2014), PubMed (1947 to September 2014), International Pharmaceutical Abstracts (1970 to September 2014), and Scopus were searched using the terms obesity, morbid obesity, thrombosis, venous thrombosis, embolism, venous thromboembolism, pulmonary embolism, low-molecular weight heparin, enoxaparin, dalteparin, tinzaparin, anti-factor Xa, anti-factor Xa monitoring, anti-factor Xa activity, and anti-factor Xa assay. The reference lists of retrieved articles were also reviewed. Study Selection and Data Extraction: English-language studies describing obese patients treated with LMWH or reporting anti-Xa activity were reviewed using a 9-step decision-making algorithm to determine whether monitoring of LMWH therapy by means of anti-Xa activity in obesity is warranted. Studies published in abstract form were excluded. Data Synthesis: The analysis showed that anti-Xa concentrations are not strongly associated with thrombosis or hemorrhage. In clinical studies of LMWH for thromboprophylaxis in bariatric surgery, orthopedic surgery, general surgery, and medical patients, and for treatment of venous thrombo embolism and acute coronary syndrome, anti-Xa activity can be predicted from dose of LMWH and total body weight; no difference in clinical outcome was found between obese and non-obese participants. Conclusions: Routinely determining anti-Xa concentrations in obese patients to monitor the clinical effectiveness of LMWH is

  6. Low-molecular-weight heparin and abciximab for thrombo-occlusive saphenous vein graft disease. Report of 2 cases.

    PubMed Central

    Yaryura, R; Doucet, J; Mathur, V S

    1997-01-01

    Both reoperation and alternative treatments for thrombo-occlusive disease of saphenous vein grafts have been fraught with a high rate of complications and a low rate of long-term success. We report 2 cases in which thrombo-occlusive saphenous vein graft disease was treated with the aid of abciximab during the intervention and with low-molecular-weight heparin for 7 to 12 days in an outpatient setting. Images PMID:9456497

  7. Evaluation of the Oral Bioavailability of Low Molecular Weight Heparin Formulated With Glycyrrhetinic Acid as Permeation Enhancer.

    PubMed

    Motlekar, Nusrat A; Srivenugopal, Kalkunte S; Wachtel, Mitchell S; Youan, Bi-Botti C

    2006-02-01

    Low molecular weight heparin (LMWH) is the agent of choice for anticoagulant therapy and prophylaxis of thrombosis and coronary syndromes. However, its therapeutic use is limited due to poor oral bioavailability. The aim of this study was to investigate the oral delivery of LMWH, ardeparin formulated with 18-beta glycyrrhetinic acid (GA), as an alternative to currently used subcutaneous (sc) delivery. Drug transport through Caco-2 cell monolayers was monitored in the presence and absence of GA by scintillation counting and transepithelial electrical resistance. Regional permeability studies using rat intestine were performed using a modified Ussing chamber. Cell viability in the presence of various concentrations of enhancer was determined by MTT assay. The absorption of ardeparin after oral administration in rats was measured by an anti-factor Xa assay. Furthermore, the eventual mucosal epithelial damage was histologically evaluated. Higher ardeparin permeability (~7-fold) compared to control was observed in the presence of 0.02 % GA. Regional permeability studies indicated predominant absorption in the duodenal segment. Cell viability studies showed no significant cytotoxicity below 0.01 % GA. Ardeparin oral bioavailability was significantly increased (F(relative)/(S.C). = 13.3%) without causing any damage to the intestinal tissues. GA enhanced the oral absorption of ardeparin both in vitro and in vivo. The oral formulation of ardeparin with GA could be absorbed in the intestine. These results suggest that GA may be used as an absorption enhancer for the oral delivery of LMWH. PMID:17710191

  8. Interaction Analysis of T7 RNA Polymerase with Heparin and Its Low Molecular Weight Derivatives - An In Silico Approach.

    PubMed

    Borkotoky, Subhomoi; Meena, Chetan Kumar; Murali, Ayaluru

    2016-01-01

    The single subunit T7 RNA polymerase (T7RNAP) is a model enzyme for studying the transcription process and for various biochemical and biophysical studies. Heparin is a commonly used inhibitor against T7RNAP and other RNA polymerases. However, exact interaction between heparin and T7RNAP is still not completely understood. In this work, we analyzed the binding pattern of heparin by docking heparin and few of its low molecular weight derivatives to T7RNAP, which helps in better understanding of T7RNAP inhibition mechanism. The efficiency of the compounds was calculated by docking the selected compounds and post-docking molecular mechanics/generalized Born surface area analysis. Evaluation of the simulation trajectories and binding free energies of the complexes after simulation showed enoxaparin to be the best among low molecular weight heparins. Binding free energy analysis revealed that van der Waals interactions and polar solvation energy provided the substantial driving force for the binding process. Furthermore, per-residue free energy decomposition analysis revealed that the residues Asp 471, Asp 506, Asp 537, Tyr 571, Met 635, Asp 653, Pro 780, and Asp 812 are important for heparin interaction. Apart from these residues, most favorable contribution in all the three complexes came from Asp 506, Tyr 571, Met 635, Glu 652, and Asp 653, which can be essential for binding of heparin-like structures with T7RNAP. The results obtained from this study will be valuable for the future rational design of novel and potent inhibitors against T7RNAP and related proteins. PMID:27594785

  9. Interaction Analysis of T7 RNA Polymerase with Heparin and Its Low Molecular Weight Derivatives – An In Silico Approach

    PubMed Central

    Borkotoky, Subhomoi; Meena, Chetan Kumar; Murali, Ayaluru

    2016-01-01

    The single subunit T7 RNA polymerase (T7RNAP) is a model enzyme for studying the transcription process and for various biochemical and biophysical studies. Heparin is a commonly used inhibitor against T7RNAP and other RNA polymerases. However, exact interaction between heparin and T7RNAP is still not completely understood. In this work, we analyzed the binding pattern of heparin by docking heparin and few of its low molecular weight derivatives to T7RNAP, which helps in better understanding of T7RNAP inhibition mechanism. The efficiency of the compounds was calculated by docking the selected compounds and post-docking molecular mechanics/generalized Born surface area analysis. Evaluation of the simulation trajectories and binding free energies of the complexes after simulation showed enoxaparin to be the best among low molecular weight heparins. Binding free energy analysis revealed that van der Waals interactions and polar solvation energy provided the substantial driving force for the binding process. Furthermore, per-residue free energy decomposition analysis revealed that the residues Asp 471, Asp 506, Asp 537, Tyr 571, Met 635, Asp 653, Pro 780, and Asp 812 are important for heparin interaction. Apart from these residues, most favorable contribution in all the three complexes came from Asp 506, Tyr 571, Met 635, Glu 652, and Asp 653, which can be essential for binding of heparin-like structures with T7RNAP. The results obtained from this study will be valuable for the future rational design of novel and potent inhibitors against T7RNAP and related proteins. PMID:27594785

  10. The development of low-molecular weight hydrogels for applications in cancer therapy

    NASA Astrophysics Data System (ADS)

    Tian, Ran; Chen, Jin; Niu, Runfang

    2014-03-01

    To improve the anti-cancer efficacy and to counteract the side effects of chemotherapy, a variety of drug delivery systems have been invented in past decades, but few of these systems have succeeded in clinical trials due to their respective inherent shortcomings. Recently, low-molecular weight hydrogels of peptides that self-assemble via non-covalent interactions have attracted considerable attention due to their good biocompatibility, low toxicity, inherent biodegradability as well as their convenience of design. Low-molecular weight hydrogels have already shown promise in biomedical applications as diverse as 3D-cell culture, enzyme immobilization, controllable MSC differentiation, wound healing, drug delivery etc. Here we review the recent development in the use of low-molecular weight hydrogels for cancer therapy, which may be helpful in the design of soft materials for drug delivery.

  11. Prevention and treatment of venous thromboembolism with low-molecular-weight heparins: Clinical implications of the recent European guidelines

    PubMed Central

    Prandoni, Paolo

    2008-01-01

    Venous thromboembolism (VTE) is an important cause of avoidable morbidity and mortality. However, routine prophylaxis for at-risk patients is underused. Recent guidelines issued by an international consensus group, including the International Union of Angiology (IUA), recommend use of low-molecular-weight heparins (LMWHs) for the treatment of acute VTE and prevention of recurrence, and for prophylaxis in surgical and medical patients. This review highlights current inadequacies in the provision of thromboprophylaxis, and considers the clinical implications of the European guidelines on the prevention and treatment of VTE. PMID:18782432

  12. Livedoid vasculopathy in a patient with lupus anticoagulant and MTHFR mutation: treatment with low-molecular-weight heparin.

    PubMed

    Abou Rahal, Jihane; Ishak, Rim S; Otrock, Zaher K; Kibbi, Abdul-Ghani; Taher, Ali T

    2012-11-01

    Livedoid vasculopathy is characterized by painful purpuric lesions on the extremities which frequently ulcerate and heal with atrophic scarring. For many years, livedoid vasculopathy has been considered to be a primary vasculitic process. However, there has been evidence considering livedoid vasculopathy as an occlusive vasculopathy due to a hypercoagulable state. We present the case of livedoid vasculopathy in a 21-year-old female who had been suffering of painful lower extremity lesions of 3 years duration. The patient was found to be lupus anticoagulant positive and homozygous for methylenetetrahydrofolate reductase C677T mutation. The patient was successfully treated with low-molecular-weight heparin. PMID:22592843

  13. A practical approach to the use of low molecular weight heparins in VTE treatment and prophylaxis in children and newborns.

    PubMed

    Molinari, Angelo Claudio; Banov, Laura; Bertamino, Marta; Barabino, Paola; Lassandro, Giuseppe; Giordano, Paola

    2015-02-01

    Low-molecular weight heparins are currently the most commonly used anticoagulants in children and newborns. However, since thrombotic complications rarely occur outside large children's hospitals, physicians often encounter some practical problems in managing these treatments when a pediatric thrombosis specialist is not available. The drug of choice is enoxaparin, due to its favorable FXa/FIIa ratio and the availability of pharmacokinetic and pharmacodynamic data. The treatment of acute thrombosis should be started with two daily injections but when compliance is an issue, a single daily administration schedule could be chosen for secondary prophylaxis ensuring careful measurement of the post 24-hour anti-FXa activity. Furthermore, a subcutaneous device may be a useful tool and a topical dermal anesthetic could be effective in controlling pain without affecting anti-FXa levels. In neonate and toddlers, where mini doses are frequently needed, the dead space of syringes and needles could represent an issue and therefore the use of insulin syringes without dead space is advisable, while a dilution of the drug is useful with other syringes. This article derives from a nonsystematic review of the available literature, with special attention to recent international guidelines and expert recommendations, combined to authors' clinical practice in large tertiary pediatric hospitals and will provide concise and practical information for the use of low-molecular weight heparin in childhood and infancy in a sort of "answering frequently asked questions." PMID:25325764

  14. Effect of heparin and a low-molecular weight heparinoid on PAF-induced airway responses in neonatally immunized rabbits.

    PubMed Central

    Sasaki, M.; Herd, C. M.; Page, C. P.

    1993-01-01

    1. We have investigated the effect of an unfractionated heparin preparation, a low-molecular weight heparinoid (Org 10172) and the polyanionic molecule polyglutamic acid against PAF-induced airway hyperresponsiveness and pulmonary cell infiltration in neonatally immunized rabbits in vivo. 2. Exposure of neonatally immunized rabbits to aerosolized platelet activating factor (PAF) (80 micrograms ml-1 for 60 min) elicited an increase in airway responsiveness to inhaled histamine 24 h and 72 h following challenge which was associated with an infiltration of inflammatory cells into the airways, as assessed by bronchoalveolar lavage (BAL). 3. A significant increase in the total numbers of cells recovered from BAL fluid was associated with significantly increased cell numbers of neutrophils, eosinophils and mononuclear cells 24 h following PAF exposure. The numbers of eosinophils and neutrophils in the airways remained elevated 72 h after challenge. 4. The intravenous administration of an unfractionated preparation of heparin (100 units kg-1) or Org 10172 (100 micrograms kg-1) 30 min prior to PAF exposure significantly inhibited the airway hyperresponsiveness induced by PAF, 24 h and 72 h following challenge. PAF-induced hyperresponsiveness was not significantly affected by prior intravenous administration of polyglutamic acid (100 micrograms kg-1). 5. The intravenous administration of unfractionated heparin (100 units kg-1), Org 10172 (100 micrograms kg-1) or polyglutamic acid (100 micrograms kg-1) 30 min prior to PAF exposure significantly inhibited the expected increase in total cell infiltration. 6. This study shows that unfractionated heparin and a low-molecular weight heparinoid, Org 10172, are capable of inhibiting both the airway hyperresponsiveness and pulmonary cell infiltration induced by PAF in the rabbit. PMID:7693273

  15. Low molecular weight heparin nanoparticles: mucoadhesion and behaviour in Caco-2 cells

    NASA Astrophysics Data System (ADS)

    Lamprecht, Alf; Koenig, Petra; Ubrich, Nathalie; Maincent, Philippe; Neumann, Dirk

    2006-08-01

    Nanoparticles (NPs) have shown their efficiency in increasing the oral bioavailability of macromolecular drugs, among them heparin. However, mechanisms of absorption are still unclear. Here, heparin-loaded NPs were prepared from different polymers (Eudragit® RS, poly(lactic-co-glycolic acid) (PLGA), and their respective mixtures) and analysed for their mucoadhesive properties using a resonant mirror system. Subsequent binding and drug transport studies of the free heparin and heparin-loaded NPs were carried out on Caco-2 cells. Cationic NPs were found to be mucoadhesive, while pure drug and polyester NPs were not. The adsorption of anionic heparin masked the positive surface charge of the particles, thus partially diminishing the adhesiveness to mucin. Increased binding to Caco-2 cells was found for all NP formulation, with RS/PLGA NPs showing maximum binding. However, the transport of heparin was the same for the RS/PLGA NPs and the PLGA NPs and slightly higher than for the free drug. In all cases, no NP transport across the cell layer was observed. When Caco-2 cells were coated with an additional mucin layer, cell binding of RS NPs and RS/PLGA NPs was further increased. Transport across Caco-2 cells demonstrated similar tendencies to results obtained without mucin. In contrast, cationic NPs led to higher heparin transport in the presence of mucin. The mechanism of drug absorption associated with RS NPs was concluded to be independent of typical transcellular NP transport.

  16. De novo synthesis of a narrow size distribution low-molecular-weight heparin

    PubMed Central

    Chandarajoti, Kasemsiri; Xu, Yongmei; Sparkenbaugh, Erica; Key, Nigel S; Pawlinski, Rafal; Liu, Jian

    2014-01-01

    Heparin, a commonly used anticoagulant drug, is a mixture of highly sulfated polysaccharides with various molecular weights (MWs). The unique sulfation pattern dictates the anticoagulant activity of heparin. Commercial heparins are categorized into three forms according to their average MW: unfractionated heparin (UFH, MWavg 14,000), low-MW heparin (LMWH, MWavg 3500–6500) and the synthetic pentasaccharide (fondaparinux, MW 1508.3). UFH is isolated from porcine intestine while LMWH is derived from UFH by various methods of depolymerization, which generate a wide range of oligosaccharide chain lengths. Different degradation methods result in structurally distinct LMWH products, displaying different pharmacological and pharmacokinetic properties. In this report, we utilized a chemoenzymatic method to synthesize LMWH with the emphasis on controlling the size distribution of the oligosaccharides. A tetrasaccharide primer and a controlled enzyme-based polymerization were employed to build a narrow size oligosaccharide backbone. The oligosaccharide backbones were further modified by a series of sulfation and epimerization steps in order to obtain a full anticoagulation activity. Determination of the anticoagulation activity in vitro and ex vivo indicated that the synthetic LMWH has higher potency than enoxaparin, a commercial LMWH drug in clinical usage. PMID:24626379

  17. Prophylaxis for the prevention of venous thromboembolism after total knee arthroplasty. A comparison between unfractionated and low-molecular-weight heparin.

    PubMed

    Faunø, P; Suomalainen, O; Rehnberg, V; Hansen, T B; Krøner, K; Soimakallio, S; Nielsen, E

    1994-12-01

    We compared the efficacy and safety of low-molecular-weight heparin with that of low-dose unfractionated heparin in the prevention of venous thromboembolism after total knee arthroplasty in a prospective, randomized, multicenter trial. One hundred and eighty-five patients were randomly assigned to two groups: ninety-two received low-molecular-weight heparin (forty milligrams of enoxaparin the evening before the operation and once a day subsequently) and ninety-three received unfractionated heparin (5000 international units the evening before the operation and three times a day thereafter). The prophylaxis was continued until bilateral ascending venography was performed six to nine days after the operation or, if venography was not done, until the eighth postoperative day. Venography revealed a prevalence of deep-vein thrombosis of 27 per cent (twenty-five of ninety-three patients) in the group that received unfractionated heparin and 23 per cent (twenty-one of ninety-two patients) in the group that received low-molecular-weight heparin. The difference was not significant (p = 0.6). Five patients (5 per cent) who received unfractionated heparin and 3 patients (3 per cent) who received low-molecular-weight heparin had a deep-vein thrombosis in the proximal veins. Two patients who received unfractionated heparin and one who received low-molecular-weight heparin had clinical symptoms suggestive of a pulmonary embolism. None of these three patients had a positive ventilation-perfusion scan. There were no deaths, major bleeding episodes, or wound hematomas necessitating operative intervention or discontinuation of the anticoagulation in the series.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7989386

  18. Dose titration study of tinzaparin, a low molecular weight heparin, in patients on chronic hemodialysis.

    PubMed

    Egfjord, M; Rosenlund, L; Hedegaard, B; Buchardt, H L; Stengel, C; Gardar, P; Andersen, L; Andersen, L

    1998-08-01

    The minimal necessary dose of Innohep (IH) (MNDI) (Innohep [tinzaparin], Leo Pharmaceutical Corp., Ballerup, Denmark) was examined in 40 patients switched from conventional heparin ([CH], Leo Pharmaceutical Corp.) to IH and in 13 patients already treated with IH. Clotting in the venous chamber and in the dialyzer was evaluated on a 4 point scale by visual inspection. IH was administrated as a bolus injection into the arterial side of the dialyzer at the beginning of dialysis sessions. The initial dose of IH was 50% of the total dose of CH used before the study (in respective IU). According to clotting in the venous chamber or dialyzer, the dose of IH was titrated by stepwise changes of 500 IU to the lowest possible dose until 3 subsequent dialysis sessions without clotting were obtained. The total dose of CH (bolus and infusion) before switching was 6,162 +/- 2,100 IU. The bleeding time from the cannulation site after dialysis, in 24 patients with A-V fistulas, was 7.1 +/- 2.8 min(triplicates). Eight patients were excluded before achieving the MNDI, 3 due to bleeding not clearly related to heparinization (1 due to gingival bleeding, 1 to epistaxis, and 1 to sugillations), 1 due to alopecia, 2 due to a need of more than 10,000 IU of IH, and 2 patients due to cessation of treatment resulting from anxiety. After switching over, the MNDI amounted to 66 +/- 26% in respective IU. The conversion IH/CH ratio correlated significantly to the blood flow rate and the type of dialyzer. When compared on 3 subsequent sessions before and after switching to IH, no differences were found in the bleeding time after decannulation and in clotting in the venous chamber while dialyzer clotting fell on the visual scale from an average of 0.36 to 0.19 (p < 0.01). No total clot formation was observed during the study. The MNDI correlated positively to the body weight, blood flow rate, and time on dialysis (with the respective coefficients of correlation of r being 0.58, 0.44, and 0.30, p

  19. [Caution for prophylaxis of thrombosis in connection with spinal anesthesia. Risk of hemorrhage when low-molecular-weight heparin is administered in epidural/spinal anesthesia].

    PubMed

    Bergqvist, D; Wiklund, L

    2000-12-01

    There is an increasing awareness of the risk of haematoma in patients anticoagulated with low molecular weight heparins and scheduled to undergo epidural or spinal anaesthesia. The mechanisms causing this are not always clear, the incidence is very low. Risk factors are discussed as well as possible precautions to avoid this iatrogenic complication. PMID:11188033

  20. The Efficacy of Low Molecular Weight Heparin for the Prevention of Venous Thromboembolism after Hip Fracture Surgery in Korean Patients

    PubMed Central

    Kim, Kwang-Kyoun; Won, Ye-Yeon

    2016-01-01

    Purpose The aim of this study was to investigate the efficacy of low-molecular-weight heparin (LMWH) for the prevention of venous thromboembolism in Korean patients who underwent hip fracture surgery (HFS). Materials and Methods Prospectively, a total 181 cases were classified into the LMWH user group (116 cases) and LMWH non-user group (65 cases). Each group was sub-classified according to fracture types as follows: 81 cases of intertrochanteric fracture (group A: 49, group B: 32) and 100 cases of neck fracture (group C: 67, group D: 33). We compared the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) according to LMWH use. Results Of the 181 cases, four DVTs were found in the LMWH user groups (1 in group A, and 3 in group C). One case of PE was found in LMWH non-user group D. The incidences of DVT and PE showed no statistically significant differences between the LMWH user and non-user groups (p=0.298 and 0.359, respectively). In subgroup analysis, no statistically significant differences were found between groups A and B and between groups C and D. Conclusion The administration of LMWH was not effective in the prevention of venous thromboembolism and PE in the Korean patients who underwent HFS. PMID:27401653

  1. Preliminary safety evaluation of a taurocholate-conjugated low-molecular-weight heparin derivative (LHT7): a potent angiogenesis inhibitor.

    PubMed

    Alam, Farzana; Chung, Seung Woo; Hwang, Seung Rim; Kim, Ji-Young; Park, Jooho; Moon, Hyun Tae; Byun, Youngro

    2015-01-01

    In our previous studies, taurocholic acid (TA)-conjugated low-molecular-weight heparin derivative (LHT7) has been proven to be a potent anti-angiogenic agent by demonstrated successful blockage capability of vascular endothelial growth factors (VEGF). Preliminary safety evaluations were conducted based on its mechanism of action and chemical behavior. For this purpose, acute toxicity study, and hematological and serological evaluations were carried out. Additionally, in order to evaluate mechanism-related side effects, both blood pressure and the occurrence of proteinuria were measured using a treatment regime of multiple high doses of LHT7 in a biodistribution study. LD50 values for LHT7 in female and male mice were 56.9 and 64.7 mg kg(-1) doses, respectively. There were no vital fluctuations in the serological and hematological parameters, except for the elevated levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at 100 and 200 mg kg(-1) doses of LHT7, representing vital changes in the liver function. Moreover, the results of mechanism-related studies showed that blood pressure at 50 mg kg(-1) did not change but showed elevated levels of protein in urine. In the biodistribution study, a slight accumulation of LHT7 in the kidney and the liver were observed at the 50 mg kg(-1) repeated dose owing to the presence of bile acid. No fatal damage was observed in this study; most observations were related to the chemical composition or the mechanism of action of the material. PMID:24532548

  2. Comparative assessment of low-molecular-weight heparins in cancer from the perspective of patient outcomes and survival

    PubMed Central

    Falanga, Anna; Vignoli, Alfonso; Diani, Erika; Marchetti, Marina

    2011-01-01

    Patients with cancer are at high risk of developing venous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism. Compared to non-cancer patients, VTE in cancer is more frequently associated with clinical consequences, including recurrent VTE, bleeding, and an increase in the risk of death. Low-molecular-weight heparins (LMWHs) are commonly recommended for the prevention and treatment of VTE in cancer patients because of their favorable risk-to-benefit profile. Indeed, compared with vitamin K antagonists, LMWHs are characterized by a reduced need for coagulation monitoring, few major bleeding episodes, and once-daily dosing, which make these drugs more suitable in the cancer setting. Guidelines have been published recently with the aim to improve the clinical outcomes in cancer patients at risk of VTE and its complications. Coagulation activation in cancer may have a role not only in thrombosis but also in tumor growth and dissemination. Hence, inhibition of fibrin formation has been considered a possible tool against the progression of malignant disease. Clinical studies show that anticoagulant drugs may have a beneficial effect on survival in cancer patients, with a major role for LMWHs. Recently a number of prospective randomized clinical trials to test LMWHs to improve cancer survival as a primary endpoint in cancer patients have been conducted. Although the results are controversial, the interest in this research area remains high. PMID:22915978

  3. Anti-proliferative effects of O-acyl-low-molecular-weight heparin derivatives on bovine pulmonary artery smooth muscle cells

    PubMed Central

    Garg, Hari G.; Mrabat, Hicham; Yu, Lunyin; Hales, Charles A.; Li, Boyangzi; Moore, Casey N.; Zhang, Fuming; Linhardt, Robert J.

    2011-01-01

    Heparin (HP) inhibits the growth of several cell types in vitro including bovine pulmonary artery (BPA) smooth muscle cells (SMCs). In initial studies we discovered that an O-hexanoylated low-molecular-weight (LMW) HP derivative having acyl groups with 6-carbon chain length was more potent inhibitor of BPA-SMCs than the starting HP. We prepared several O-acylated LMWHP derivatives having 4-, 6-, 8-, 10-, 12-, and 18- carbon acyl chain lengths to determine the optimal acyl chain length for maximum anti-proliferative properties of BPA-SMCs. The starting LMWHP was prepared from unfractionated HP by sodium periodate treatment followed by sodium borohydride reduction. The tri-n-butylammonium salt of this LMWHP was O-acylated with butanoic, hexanoic, octanoic, decanoic, dodecanoic, and stearyl anhydrides separately to give respective O-acylated LMWHP derivatives. Gradient polyacrylamide gel electrophoresis (PAGE) was used to examine the average molecular weights of those O-acylated LMWHP derivatives. NMR analysis indicated the presence of one O-acyl group per disaccharide residue. Measurement of the inhibition of BPA-SMCS as a function of O-acyl chain length shows two optima, at a carbon chain length of 6 (O-hexanoylated LMWHP) and at a carbon chain length 12–18 (O-dodecanoyl and O-stearyl LMWHPs). A solution competition SPR study was performed to test the ability of different O-acylated LMWHP derivatives to inhibit fibroblast growth factor (FGF) 1 and FGF2 binding to surface-immobilized heparin. All the LMWHP derivatives bound to FGF1 and FGF2 but each exhibited slightly different binding affinity. PMID:21773727

  4. Low-molecular-weight heparin modulates vein wall fibrotic response in a plasminogen activator inhibitor 1-dependent manner

    PubMed Central

    Obi, Andrea T.; Diaz, Jose A.; Ballard-Lipka, Nicole L.; Roelofs, Karen J.; Farris, Diana M.; Lawrence, Daniel A.; Henke, Peter K.; Wakefield, Thomas W.

    2014-01-01

    Background Treatment with low-molecular-weight heparin (LMWH) favorably alters the vein wall response to deep venous thrombosis (DVT), although the mechanisms remain unclear. Previous studies have suggested that LMWH alters the levels of circulating plasminogen activator inhibitor 1 (PAI-1), a known mediator of fibrosis, and may improve endogenous fibrinolysis. We hypothesized that LMWH favorably alters the vein wall response by binding of PAI-1 and acceleration of fibrinolysis. Methods Wild-type and PAI-1 −/− mice underwent treatment with LMWH after induction of occlusive DVT. Vein wall and plasma were harvested and analyzed by enzyme-linked immunosorbent assay, zymography, real-time polymerase chain reaction, and immunohistochemistry. Results Wild-type mice treated with LMWH exhibited diminished vein wall fibrosis (0.6 ± 0.6 vs 1.4 ± 0.2; P < .01; n = 5) and elevation of circulating PAI-1 (1776 ± 342 vs 567 ± 104 ρg/mL; P < .01; n = 5) compared with untreated controls after occlusive DVT. PAI-1−/− mice treated with LMWH were not similarly protected from fibrosis, despite improved thrombus resolution. Treatment with LMWH was associated with decreased intrathrombus interleukin-lβ (68.6 ± 31.0 vs 223.4 ± 28.9 ρg/mg total protein; P < .01; n = 5) but did not alter inflammatory cell recruitment to the vein wall. PAI-1 −/− mice exhibited significantly elevated intrathrombus (257.2 ± 51.5 vs 4.3 ± 3.8 ρg/mg total protein; n = 5) and vein wall interleukin-13 (187.2 ± 57.6 vs 9.9 ± 1.1 ρg/mg total protein; P < .05; n = 5) as well as vein wall F4/80 positively staining monocytes (53 ± 11 vs 16 ± 2 cells/5 high-power fields; P < .05; n = 4). Conclusions LMWH did not accelerate venous thrombosis resolution but did protect against vein wall fibrosis in a PAI-1-dependent manner in an occlusive DVT model. Lack of PAI-1 correlated with accelerated venous thrombosis resolution but no protection from fibrosis. PAI-1 inhibition as a treatment strategy

  5. Low molecular weight heparin prevents CLP-induced acute lung injury in rats by anti-inflammatory coagulation.

    PubMed

    Lu, Xiao; Zhao, Liang; Xu, Yong-Hua

    2013-02-01

    The aim of our study was to observe the influence of low molecular Weight heparin (LMWH) on systemic inflammation, including high mobility group box 1 protein (HMGB1) and protective effect on acute lung injury induced by cecal ligation and puncture(CLP). Discuss the mechanism of this effect. 144 male SD rats were randomly divided into sham operation group (A), normal treatment group (B), the LMWH treatment group (C), n=48.Group A received a sham operation and the other groups were underwent CLP operation. Groups A and B accepted intraperitoneal injection (i.p.) of normal saline (NS) at a dose of 2.0 ml/kg and ceftriaxone (30 mg/kg), Group C were intraperitoneal injection additional LMWH (150 U/kg) except saline and ceftriaxone. Observe points were made at 3, 6, 12, 18, 24, 48 h, the rats were anesthetized and killed, mortality, lungs wet/dry ratio and Pathology change were determined. HMGB-1 mRNA, protein of lung tissues was calculated by RT-PCR and Western blot. TNF-α and IL-6 of blood plasma calculated by ELSIA. There was significantly different in each index between A and B group (p<0.05).Compared with CLP group, there was a significant decrease in the lung injury, the mortality, HMGB1 mRNA and protein expression on lung tissues (p<0.05). LMWH can decreases cytokine, HMGB1 levels of lung tissue during CLP-induced inflammation. As a result, LMWH ameliorated lung pathology and reduces mortality in CLP-induced systemic inflammation in a rat model. This effect may be mediated through the inhibition of axis of inflammation and coagulation. PMID:23448611

  6. Preparation and optimization of N-trimethyl-O-carboxymethyl chitosan nanoparticles for delivery of low-molecular-weight heparin.

    PubMed

    Mahjub, Reza; Heidari Shayesteh, Tavakol; Radmehr, Moojan; Vafaei, Seyed Yaser; Amini, Mohsen; Dinarvand, Rasoul; Dorkoosh, Farid Abedin

    2016-01-01

    The aim of this study was preparation, optimization and in vitro characterization of nanoparticles composed of 6-[O-carboxymethyl]-[N,N,N-trimethyl] (TMCMC) for oral delivery of low-molecular-weight heparin. The chitosan derivative was synthesized. Nanoparticles were prepared using the polyelectrolyte complexation method. Box-Behnken response surface experimental design methodology was used for optimization of nanoparticles. The morphology of nanoparticles was studied using transmission electron microscopy. In vitro release of enoxaparin from nanoparticles was determined under simulated intestinal fluid. The cytotoxicity of nanoparticles on a Caco-2 cell line was determined, and finally the transport of prepared nanoparticles across Caco-2 cell monolayer was defined. Optimized nanoparticles with proper physico-chemical properties were obtained. The size, zeta potential, poly-dispersity index, entrapment efficiency and loading efficiency of nanoparticles were reported as 235 ± 24.3 nm, +18.6 ± 2.57 mV, 0.230 ± 0.03, 76.4 ± 5.43% and 12.6 ± 1.37%, respectively. Morphological studies revealed spherical nanoparticles with no sign of aggregation. In vitro release studies demonstrated that 93.6 ± 1.17% of enoxaparin released from nanoparticles after 600 min of incubation. MTT cell cytotoxicity studies showed no cytotoxicity at 3 h post-incubation, while the study demonstrated concentration-dependent cytotoxicity after 24 h of exposure. The obtained data had shown that the nanoparticles prepared from trimethylcarboxymethyl chitosan may be considered as a good candidate for oral delivery of enoxaparin. PMID:25255172

  7. Histopathologic effects of a low molecular weight heparin on bone healing in rats: a promising adjuvant in dacryocystorhinostomy

    PubMed Central

    Alp, Mehmet Numan; Oken, Ozdamar Fuad; Sargon, Mustafa Fevzi; Ucaner, Ahmet

    2016-01-01

    AIM To investigate the effect of short-term prophylactic dose of a low molecular weight heparin (LMWH) drug on the bone healing process in an animal model simulating the osteotomy obtained in dacryocystorhinostomy. METHODS Forty male Wistar albino rats were divided into 2 groups. Subcutaneous injections of enoxaparin 1 mg/kg (enoxaparin-treated group) and saline solution (control group) were performed once daily for 4d, beginning on the first preoperative day. The osteotomy was created at the femoral diaphysis in all animals by using a Kirschner wire. Each group was further divided into 2 subgroups depending on the timing of the second operation, 14 or 21d following initial osteotomy. Patent osteotomy area on the second and the third weeks in each group were calculated by using a computer software on digital micrographs. RESULTS The patent osteotomy areas at the second and the third weeks were significantly larger in the enoxaparin-treated group than those of the control group (P<0.001 for each time-period). In the control group, the patent osteotomy area at the third week of healing was significantly smaller than that of the second week (P=0.003), whereas there was no significant difference between these two measurements in the enoxaparin-treated group (P=0.185). CONCLUSION Short-term administration of enoxaparin resultes in a significant alteration in bone healing at 14 and 21d after injury. LMWHs can be regarded as promising alternative adjuvants in dacryocystorhinostomy after being evaluated with further clinical and animal studies. PMID:27366684

  8. Low-molecular-weight heparin for prevention of placenta-mediated pregnancy complications: protocol for a systematic review and individual patient data meta-analysis (AFFIRM)

    PubMed Central

    2014-01-01

    Background Placenta-mediated pregnancy complications include pre-eclampsia, late pregnancy loss, placental abruption, and the small-for-gestational age newborn. They are leading causes of maternal, fetal, and neonatal morbidity and mortality in developed nations. Women who have experienced these complications are at an elevated risk of recurrence in subsequent pregnancies. However, despite decades of research no effective strategies to prevent recurrence have been identified, until recently. We completed a pooled summary-based meta-analysis that strongly suggests that low-molecular-weight heparin reduces the risk of recurrent placenta-mediated complications. The proposed individual patient data meta-analysis builds on this successful collaboration. The project is called AFFIRM, An individual patient data meta-analysis oF low-molecular-weight heparin For prevention of placenta-medIated pRegnancy coMplications. Methods/Design We conducted a systematic review to identify randomized controlled trials with a low-molecular-weight heparin intervention for the prevention of recurrent placenta-mediated pregnancy complications. Investigators and statisticians representing eight trials met to discuss the outcomes and analysis plan for an individual patient data meta-analysis. An additional trial has since been added for a total of nine eligible trials. The primary analyses from the original trials will be replicated for quality assurance prior to recoding the data from each trial and combining it into a common dataset for analysis. Using the anonymized combined data we will conduct logistic regression and subgroup analyses aimed at identifying which women with previous pregnancy complications benefit most from treatment with low-molecular-weight heparin during pregnancy. Discussion The goal of the proposed individual patient data meta-analysis is a thorough estimation of treatment effects in patients with prior individual placenta-mediated pregnancy complications and

  9. Low molecular weight oligochitosans for non-viral retinal gene therapy.

    PubMed

    Puras, G; Zarate, J; Aceves, M; Murua, A; Díaz, A R; Avilés-Triguero, M; Fernández, E; Pedraz, J L

    2013-02-01

    Ultrapure oligochitosans have recently been evaluated as a promising tool for corneal gene therapy; however, there are no reports regarding the potential use of this polymer in other ocular tissues. We have prepared and characterized at pH 7.1 oligochitosan/pCMS-EGFP polyplexes to evaluate the transfection efficiency in rat retinas after subretinal and intravitreal administration. Polyplexes were characterized in terms of shape, size, surface charge, DNA condensation, and transfection efficiency in HEK-293 and ARPE-19 culture cells. Polyplexes were positively charged, around 10 mV, and size oscillated between 256.5 ± 56 and 67.3 ± 0.44 nm, depending on the nitrogenous/phosphate ratio. Polyplexes efficiently protected the plasmid against enzymatic digestion. A drastic increase in transfection efficiency was observed when pH slightly decreased from 7.4 to 7.1 in both HEK-293 (from 19.1% to 51.5%) and ARPE-19 (from 2.0% to 36.5%) cells (data normalized to Lipofectamine™ 2000). In rat retinas, subretinal administrations transfected cells mainly in the RPE layer, whereas intravitreal injections transfected cells in the inner nuclear and plexiform layers of the retina and mainly in the ganglion cell layer. This study establishes the base for future treatments of genetic retinal disorders with low molecular weight oligochitosan polyplexes. PMID:23059418

  10. The efficacy and safety of low-molecular-weight heparin and unfractionated heparin in the treatment of cerebral venous sinus thrombosis

    PubMed Central

    Afshari, Daryoush; Moradian, Nasrin; Nasiri, Freshteh; Razazian, Nazanin; Bostani, Arash; Sariaslani, Payam

    2015-01-01

    Objective: To compare the efficacy and safety of low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) in the treatment of patients with cerebral venous sinus thrombosis (CVST), and to provide an appropriate treatment option in these patients. Method: This is a randomized double blind clinical trial conducted between December 2013 and December 2014. The subjects were selected among patients referred to Neurology Department, Imam Reza Hospital; affiliated to Kermanshah University of Medical Sciences, Kermanshah, Iran. Fifty-two cases of CVST were included in this study and randomly divided into 2 groups. Twenty-six cases received LMWH and the other 26 cases received UFH. The primary outcomes include hospital mortality rate and neurologic deficits as assessed by the National Institutes of Health Stroke Scale (NIHSS). The secondary end point was disability as measured by the Modified Rankin Scale (MRS). Results: We observed the rate of mortality and neurological deficits and disability based on NIHSS, and the MRS did not differ between the 2 groups. Conclusion: The efficacy of LMWH and UFH in reduction of neurologic deficit and functional disability in patients with CVST are similar. PMID:26492115

  11. Efficacy and safety of low molecular weight heparin compared to unfractionated heparin for chronic outpatient hemodialysis in end stage renal disease: systematic review and meta-analysis.

    PubMed

    Palamaner Subash Shantha, Ghanshyam; Kumar, Anita Ashok; Sethi, Mansha; Khanna, Rohit C; Pancholy, Samir Bipin

    2015-01-01

    Background. Low molecular weight heparin (LMWH) is an effective anti-coagulant for thrombotic events. However, due to its predominant renal clearance, there are concerns that it might be associated with increased bleeding in patients with renal disease. Objectives. We systematically evaluated the efficacy and safety of LMWH compared to unfractionated heparin (UH) in end stage renal disease (ESRD) patients. Search Methods. Pubmed, Embase and cochrane central were searched for eligible citations. Selection Criteria. Randomized controlled trials, comparing LMWH and UH, involving adult (age > 18 years), ESRD patients receiving outpatient, chronic, intermittent hemodialysis were included. Data Collection and Analysis. Two independent reviewers performed independent data abstraction. I2 statistic was used to assess heterogeneity. Random effects model was used for meta-analysis. Results. Nineteen studies were included for systematic review and 4 were included for meta-analysis. There were no significant differences between LMWH and UFH for extracorporeal circuit thrombosis [risk ratio: 1 (95% CI [0.62-1.62])] and bleeding complications [risk ratio: 1.16 (95% CI [0.62-2.15])]. Conclusions. LMWH is as safe and effective as UFH. Considering the poor quality of studies included for the review, larger well conducted RCTs are required before conclusions can be drawn. PMID:25780780

  12. Combination chemotherapy of doxorubicin, all-trans retinoic acid and low molecular weight heparin based on self-assembled multi-functional polymeric nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Xiong, Hui; Zohra Dahmani, Fatima; Sun, Li; Li, Yuanke; Yao, Li; Zhou, Jianping; Yao, Jing

    2015-04-01

    Based on the complementary effects of doxorubicin (DOX), all-trans retinoic acid (ATRA) and low molecular weight heparin (LMWH), the combination therapy of DOX, ATRA and LMWH was expected to exert the enhanced anti-tumor effects and reduce the side effects. In this study, amphiphilic LMWH-ATRA conjugate was synthesized for encapsulating the DOX. In this way, DOX, ATRA and LMWH were assembled into a single nano-system by both chemical and physical modes to obtain a novel anti-tumor targeting drug delivery system that can realize the simultaneous delivery of multiple drugs with different properties to the tumor. LMWH-ATRA nanoparticles exhibited good loading capacities for DOX with excellent physico-chemical properties, good biocompatibility, and good differentiation-inducing activity and antiangiogenic activity. The drug-loading capacity was up to 18.7% with an entrapment efficiency of 78.8%. It was also found that DOX-loaded LMWH-ATRA nanoparticles (DHR nanoparticles) could be efficiently taken up by tumor cells via endocytic pathway, and mainly distributed in cytoplasm at first, then transferred into cell nucleus. Cell viability assays suggested that DHR nanoparticles maintained the cytotoxicity effect of DOX on MCF-7 cells. Moreover, the in vivo imaging analysis indicated that DiR-loaded LMWH-ATRA nanoparticles could target the tumor more effectively as compared to free DiR. Furthermore, DHR nanoparticles possessed much higher anticancer activity and reduced side effects compared to free drugs solution. These results suggested that DHR nanoparticles could be considered as a promising targeted delivery system for combination cancer chemotherapy with lower adverse effects.

  13. Combination chemotherapy of doxorubicin, all-trans retinoic acid and low molecular weight heparin based on self-assembled multi-functional polymeric nanoparticles.

    PubMed

    Zhang, Ting; Xiong, Hui; Dahmani, Fatima Zohra; Sun, Li; Li, Yuanke; Yao, Li; Zhou, Jianping; Yao, Jing

    2015-04-10

    Based on the complementary effects of doxorubicin (DOX), all-trans retinoic acid (ATRA) and low molecular weight heparin (LMWH), the combination therapy of DOX, ATRA and LMWH was expected to exert the enhanced anti-tumor effects and reduce the side effects. In this study, amphiphilic LMWH-ATRA conjugate was synthesized for encapsulating the DOX. In this way, DOX, ATRA and LMWH were assembled into a single nano-system by both chemical and physical modes to obtain a novel anti-tumor targeting drug delivery system that can realize the simultaneous delivery of multiple drugs with different properties to the tumor. LMWH-ATRA nanoparticles exhibited good loading capacities for DOX with excellent physico-chemical properties, good biocompatibility, and good differentiation-inducing activity and antiangiogenic activity. The drug-loading capacity was up to 18.7% with an entrapment efficiency of 78.8%. It was also found that DOX-loaded LMWH-ATRA nanoparticles (DHR nanoparticles) could be efficiently taken up by tumor cells via endocytic pathway, and mainly distributed in cytoplasm at first, then transferred into cell nucleus. Cell viability assays suggested that DHR nanoparticles maintained the cytotoxicity effect of DOX on MCF-7 cells. Moreover, the in vivo imaging analysis indicated that DiR-loaded LMWH-ATRA nanoparticles could target the tumor more effectively as compared to free DiR. Furthermore, DHR nanoparticles possessed much higher anticancer activity and reduced side effects compared to free drugs solution. These results suggested that DHR nanoparticles could be considered as a promising targeted delivery system for combination cancer chemotherapy with lower adverse effects. PMID:25771790

  14. The Impact of Inherited Thrombophilia Types and Low Molecular Weight Heparin Treatment on Pregnancy Complications in Women with Previous Adverse Outcome

    PubMed Central

    Aracic, Nada; Roje, Damir; Jakus, Ivana Alujevic; Bakotin, Marinela

    2016-01-01

    Purpose To assess the distribution of births and spontaneous abortions, first-trimester abortion (FTA) and mid-trimester abortion (MTA), in untreated (n=128) and low molecular weight heparin (LMWH) treated pregnancies (n=50) of the same women with inherited thrombophilias and adverse pregnancy outcome (APO) in previous pregnancies. We particularly investigated the impact of LMWH on reducing the pregnancy complications in two thrombophilia types, "Conventional" and "Novel". Materials and Methods 50 women with inherited thrombophilia (26 Conventional and 24 Novel) and APO in previous pregnancies were included in the study. Conventional group included factor V Leiden (FVL), prothrombin G20210A (PT) mutations and antithrombin (AT), protein S (PS), and protein C (PC) deficiency, while the Novel group included methylentetrahydrofolate-reductase (MTHFR), plasminogen activator inhibitor-1 (PAI-1), and angiotensin converting enzyme (ACE) polymorphism. APO was defined as one of the following: preterm birth (PTB), fetal growth restriction (FGR), preeclampsia (PE), intrauterine fetal death (IUFD), placental abruption (PA) and deep venous thrombosis (DVT). Results There was no difference in distribution of births and spontaneous abortions between Conventional and Novel thrombophilia in untreated pregnancies (χ2=2.7; p=0.100) and LMWH treated pregnancies (χ2=0.442; p=0.506). In untreaed pregnancies thrombophilia type did not have any impact on the frequency of FTA and MTA (χ2=0.14; p=0.711). In birth-ended pregnancies LMWH treatement reduced the incidence of IUFD (p=0.011) in Conventional and FGR, IUFD, and PTB in Novel thrombophilia group. Conclusion The equal impact of two thrombophilia types on the pregnancy outcomes and a more favorable effect of LMWH therapy on pregnancy complications in Novel thrombophilia group point the need for Novel thrombophilias screening and the future studies on this issue should be recommended. PMID:27401656

  15. Beneficial cardio-renovascular effects of a low-molecular-weight heparin-derivative on adriamycin-induced glycosaminoglycanuria and tissue lipid abnormalities.

    PubMed

    Deepa, P R; Varalakshmi, P

    2005-07-01

    The present work includes a study on the glycosaminoglycanuric condition induced by adriamycin (ADR, a chemotherapeutic agent) and the accompanying secondary hyperlipidemia, wherein the treatment with a low-molecular-weight heparin-derivative (LMWH), certoparin, is evaluated for its protective role (if any) on these parameters. Two groups of male albino rats of the Wistar strain (140+/-10 g) received a single intravenous injection of adriamycin (7.5 mg/kg), and one of these groups was treated with a low-molecular-weight heparin-derivative (Certoparin Sodium, Troparin; 300 microg/day/rat s.c.), commencing on day 8, for a week. Urinary total glycosaminoglycans excretion of the untreated ADR-induced group was found to increase on the 8th and the 15th days of observation, when compared with the controls. The LMWH treatment commencing on day 8 resulted in minimising the glycosaminoglycans (GAGs) excretion by day 15 (p<0.001). Plasma, cardiac, hepatic and renal lipids (cholesterol, triglycerides and phospholipids) showed a sharp increase in the pathologic group, along with a rise in plasma LDL and VLDL cholesterol and drop in HDL cholesterol levels, paralleled by abnormal activities of the enzymes involved in lipid metabolism. LMWH treated group showed a normalised lipid profile and the activities of the lipid-metabolising enzymes was close to that of controls. It is concluded herein that adriamycin administration resulted in severe nephropathy manifested by increased glycosaminoglycanuria and abnormal lipid metabolism, and that LMWH treatment afforded substantial protection by restoring glomerular structure and function, and normalised the plasma and tissue lipid levels, lipoprotein profile and the activities of lipid-metabolising enzymes. PMID:15863250

  16. Deep vein thrombosis in elderly Hong Kong Chinese with hip fractures detected with compression ultrasound and Doppler imaging: incidence and effect of low molecular weight heparin.

    PubMed

    Kew, J; Lee, Y L; Davey, I C; Ho, S Y; Fung, K C; Metreweli, C

    1999-01-01

    Seventy-eight patients of average age 78 years suffering from an unilateral non-pathological hip fracture underwent compression ultrasound and pulsed and colour Doppler examination of both legs. Twenty-three patients were randomly placed on low molecular weight heparin (LMWH). Twenty-nine (37%) suffered deep venous thrombosis (DVT). There was no statistically significant difference in the incidence of DVT between the control and LMWH groups, and the incidence of DVT in elderly Chinese patients after hip replacement for a hip fracture is similar to that in other studies in Caucasians. There were, however, some differences, namely the contiguous nature of the thrombi rather than focal segmental clots, and the absence of propagation or tail formation. Although the numbers are small, this could possibly represent a population difference. There was a significantly increased occurrence of DVTs on the operated side in both groups. Serial ultrasound examination supports evidence that DVTs occur in the 1st week postoperatively, but there were also a number of patients who developed DVTs in the 2nd week. There was no statistically significant difference in overall incidence of DVT between patients on prophylactic heparin and the control group. Patients on prophylactic heparin had no thigh DVTs in comparison to the control group. LMWH may thus be effective in preventing thigh DVTs and pulmonary emboli. PMID:10392509

  17. [Effect on low-molecular-weight heparin obtained using a chitinolytic complex on the anticoagulant activity of plasma in rabbits and rats].

    PubMed

    Drozd, N N; Tolstenkov, A S; Makarov, V A; Miftakhova, N T; Bannikova, G E; Sukhanova, P P; Varlamov, V P; Vikhoreva, G E

    2007-01-01

    The anticoagulant activity of low-molecular-weight heparin with an average molecular weight of 4.7 kD (LMWH-4.7) has been studied. This derivative was prepared from unfractionated heparin with the help of chitinolytic enzyme complex from Streptomyces kurssanovii. The antithrombin activity of LMWH-4.7 (aIla activity) was 72 +/- 9 IU/mg and the activity with respect to the blood coagulation factor Xa (aXa activity) was 200 +/- 33 IU/mg, which corresponded to an aXa/aIIa ratio of 2.8 (necessary for effective antithrombotic drugs). The aIIa and aXa activity exhibited a dose-dependent variation upon intravenous and subcutaneous injections in rabbits, so that a high aIIa/aXa ratio was retained: 5 min after the intravenous injection of a minimum dose (0.3 mg/kg), this ratio was 2, 7, and for a greater dose (3.0 mg/kg) it reached 3.8. Subcutaneous injections were followed by slow elimination of the anticoagulant within 24 h. LMWH-4.7 upon intraperitoneal injections produced a dose-dependent inhibition of a model thrombosis in rats. Complete inhibition was observed for a dose of 3 mg/kg. Thus, it is possible to obtain active LMW heparin with the help of chitinases. PMID:17523450

  18. Profiling analysis of low molecular weight heparins by multiple heart-cutting two dimensional chromatography with quadruple time-of-flight mass spectrometry.

    PubMed

    Ouyang, Yilan; Zeng, Yangyang; Rong, Yinxiu; Song, Yue; Shi, Lv; Chen, Bo; Yang, Xinlei; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2015-09-01

    Low molecular weight heparins (LMWHs) are polydisperse and microheterogenous mixtures of polysaccharides used as anticoagulant drugs. Profiling analysis is important for obtaining deeper insights into the structure of LMWHs. Previous oligosaccharide mapping methods are relatively low resolution and are unable to show an entire picture of the structural complexity of LMWHs. In the current study a profiling method was developed relying on multiple heart-cutting, two-dimensional, ultrahigh performance liquid chromatography with quadruple time-of-flight mass spectrometry. This represents an efficient, automated, and robust approach for profiling LMWHs. Using size-exclusion chromatography and ion-pairing reversed-phase chromatography in a two-dimensional separation, LMW components of different sizes and LMW components of the same size but with different charges and polarities can be resolved, providing a more complete picture of a LMWH. Structural information on each component was then obtained with quadrupole time-of-flight mass spectrometry. More than 80 and 120 oligosaccharides were observed and unambiguously assigned from the LMWHs, nadroparin and enoxaparin, respectively. This method might be useful for quality control of LMWHs and as a powerful tool for heparin-related glycomics. PMID:26222954

  19. Low-Molecular-Weight Heparin (Reviparin) Reduces the Incidence of Femoropopliteal In-Stent Stenosis: Preliminary Results of an Ongoing Study

    SciTech Connect

    Strecker, Ernst-Peter K.; Goettmann, Dieter; Boos, Irene B. L.; Vetter, Sylvia

    1998-09-15

    Purpose: To examine the efficacy of the low-molecular-weight heparin, reviparin, for prevention of femoropopliteal stent restenosis. Methods: Forty-two patients who had implantation of flexible tantalum stents for the treatment of stenosis (n= 24) or occlusion (n= 18) of the femoral (n= 27) or popliteal (n= 15) arteries were included in this study protocol. An intraarterial bolus of 5000 IU heparin was given before percutaneous transluminal angioplasty (PTA), and in the case of stent implantation due to unsuccessful PTA, an additional dose of reviparin (3500 anti-factor Xa IU) was given. Postprocedurally, 10,500 anti-factor Xa IU of reviparin were administered intravenously over 24 hr, followed by 3500 anti-factor Xa IU subcutaneously twice a day for 23 days. Oral aspirin (100 mg/day) was prescribed for the long term. Follow-up criteria (maximum follow-up 37 months) were clinical symptoms, Doppler ankle arm indices, color and duplex sonography, and angiography for suspicion of restenosis. Results: Early stent thromboses were not observed. Overall primary patency rate (PPR) was 88% {+-} 6.0% (1 year) and 74% {+-} 10.1% (2 years). Major hemorrhagic complications have not occurred. Conclusion: Reviparin administered in a high dose over a period of 24 days is a safe medication regimen and provides excellent patency rates after stent implantation.

  20. Low Molecular Weight Heparin (LMWH) Improves Peritoneal Function and Inhibits Peritoneal Fibrosis Possibly through Suppression of HIF-1α, VEGF and TGF-β1

    PubMed Central

    Li, Juan; Guo, Zhi Yong; Gao, Xian Hua; Bian, Qi; Jia, Meng; Li Lai, Xue; Wang, Tie Yun; Bian, Xiao Lu; Wang, Hai Yan

    2015-01-01

    Background Peritoneal fibrosis is the major cause of ultrafiltration failure, and intraperitoneal administration of Low Molecular Weight Heparin (LMWH) was reported to protect peritoneal function. But the exact mechanism of its influence on peritoneal structure and function is still unknown. Methods A fibrosis model of rat was established by intraperitoneal (IP) administration of PD fluid and Erythromycin Lactobionate. Fifty-two rats were randomly divided into 6 groups: (1) normal control group (CON, n = 6); (2) normal saline group (NS, n = 10); (3) high-glucose group (GLU, n = 10); (4) heparin group (HEP, n = 6); (5) low dose LMWH group (LLMWH, n = 10); (6) high dose LMWH group (HLMWH, n = 10). Two hour peritoneal equilibration test was performed after 28 days of intervention. The peritoneum, mesentery and omentum were harvested, and evaluated by Hematoxylin-Eosin and Masson Trichrome staining. The expressions of HIF-1α, VEGF and TGF-β1 in parietal peritoneum were detected by IHC and RT-PCR (Reverse Transcriptase Polymerase Chain Reaction). Results Compared with group CON and NS, ultrafiltration volume and D2/D0 glucose in group GLU decreased significantly, D/Purea (Dialysate-Plasma ratio of urea), D/Palb (Dialysate-Plasma ratio of albumin), peritoneal thickness, neoangiogenesis and inflammatory reaction increased significantly (all P<0.05). Administration of heparin and LMWH markedly alleviated these above pathological changes. The protein and mRNA levels of HIF-1α, VEGF and TGF-β1 increased significantly in group GLU, and decreased significantly after administration of LMWH in a dose-dependent manner. Conclusions LMWH ameliorates peritoneal function and inhibits peritoneal fibrosis, possibly through suppression of HIF-1α, VEGF and TGF-β1. PMID:25723475

  1. [Long-term treatment with a low-molecular-weight heparin administered subcutaneously compared with a vitamin K antagonist: subanalysis of patients with cancer].

    PubMed

    Romera-Villegas, Antonio; Martí Mestre, Xavier; Vila Coll, Ramón; Colomé Nafría, Esteve

    2015-01-01

    We performed a subanalysis of cancer patients enrolled in a clinical trial that compared long-term (6 months) treatment with a low-molecular-weight heparin (LMWH) administered subcutaneously or with acenocoumarol. The subanalysis assessed whether the characteristics of the tumor had an influence on the clinical response. A randomized open trial included 69 patients with cancer and symptomatic proximal deep vein thrombosis of the lower limbs. The tumor characteristics and treatment type were recorded. The main assessment criterion was the 12-month incidence of recurrent symptomatic venous thromboembolism (VTE). Sixty-one patients (88.4%) were analyzed. At the time of inclusion, the cancer characteristics and treatment were comparable between the 2 groups. Over the course of 12 months, the recurrent VTE was significantly greater in the elderly patients (71.5 ± 6.4 vs. 62.0 ± 15.1; p=.006). The logistic regression analysis showed no association between VTE recurrence and the location or extent of the tumor. However, the use of thrombogenic chemotherapy (p=.045) was independently associated with VTE recurrence, and longterm treatment with tinzaparin was almost a protective factor (p=.15). In this small sample, we observed an association between thrombogenic chemotherapy and recurrent VTE. The tendency towards a reduction in VTE recurrence at 12 months in patients with cancer in the LMWH group could be attributed to the effect of the full LMWH dosage. PMID:25771087

  2. Low-molecular-weight heparins for managing vasoocclusive crises in people with sickle cell disease: a summary of a cochrane systematic review.

    PubMed

    van Zuuren, Esther J; Fedorowicz, Zbys

    2014-01-01

    We summarize a Cochrane systematic review that was conducted to assess the effects of low-molecular-weight heparins (LMWH) for managing vasoocclusive crises (VOC) in people with sickle cell disease. Sickle cell disease is one of the most common and severe genetic disorders in the world. It can be divided into three broadly distinct clinical phenotypes characterized by either hemolysis, pain syndromes or organ damage. Pain is the most prominent symptom of vasoocclusion, and hypercoagulability is a well-established pathogenic phenomenon in people with sickle cell disease. Searches included the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, abstract books of conference proceedings and several online trials registries (December 2012). One study (with an overall unclear to high risk of bias) comprising 253 participants was included. This study provided limited data, but concluded that tinzaparin resulted in a more rapid resolution of pain, and in a statistically significant lower number of hospitalization days compared to a placebo. Two minor bleeding events were reported as adverse events in the tinzaparin group. Based on the results from this single study, there is incomplete evidence to either support or refute the effectiveness of LMWH in people with sickle cell disease. PMID:24826795

  3. Preparation and characterization of self-assembled nanoparticles based on low-molecular-weight heparin and stearylamine conjugates for controlled delivery of docetaxel

    PubMed Central

    Kim, Dong-Hwan; Termsarasab, Ubonvan; Cho, Hyun-Jong; Yoon, In-Soo; Lee, Jae-Young; Moon, Hyun Tae; Kim, Dae-Duk

    2014-01-01

    Low-molecular-weight heparin (LMWH)–stearylamine (SA) conjugates (LHSA)-based self-assembled nanoparticles were prepared for intravenous delivery of docetaxel (DCT). 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide were used as coupling agents for synthesis of LHSA conjugates. The physicochemical properties, in vitro antitumor efficacy, in vitro cellular uptake efficiency, in vivo antitumor efficacy, and in vivo pharmacokinetics of LHSA nanoparticles were investigated. The LHSA nanoparticles exhibited a spherical shape with a mean diameter of 140–180 nm and a negative surface charge. According to in vitro release and in vivo pharmacokinetic test results, the docetaxel-loaded LHSA5 (LMWH:SA =1:5) nanoparticles exhibited sustained drug release profiles. The blank LHSA nanoparticles demonstrated only an insignificant cytotoxicity in MCF-7 and MDAMB 231 human breast cancer cells; additionally, higher cellular uptake of coumarin 6 (C6) in MCF-7 and MDAMB 231 cells was observed in the LHSA5 nanoparticles group than that in the C6 solution group. The in vivo tumor growth inhibition efficacy of docetaxel-loaded LHSA5 nanoparticles was also significantly higher than the Taxotere®-treated group in the MDAMB 231 tumor-xenografted mouse model. These results indicated that the LHSA5-based nanoparticles could be a promising anticancer drug delivery system. PMID:25525355

  4. Efficacy and safety of low-molecular-weight heparin in patients with sepsis: a meta-analysis of randomized controlled trials

    PubMed Central

    Fan, Yu; Jiang, Menglin; Gong, Dandan; Zou, Chen

    2016-01-01

    Low-molecular-weight heparin (LMWH) is part of standard supportive care. We conducted a meta-analysis to investigate the efficacy and safety of LMWH in septic patients. We searched Pubmed, Embase, CKNI and Wanfang database prior to July 2015 for randomized controlled trials investigating treatment with LMWH in septic patients. We identified 11 trials involving 594 septic patients. Meta-analysis showed that LMWH significantly reduced prothrombin time (mean differences [MD] −0.88; 95% CI −1.47 to −0.29), APACHE II score (MD −2.50; 95% CI −3.55 to −1.46), and 28-day mortality (risk ratio [RR] 0.72; 95% CI 0.57–0.91) as well as increased the platelet counts (MD 18.33; 95% CI 0.73–35.93) than the usual treatment. However, LMWH did not reduce D-dimer (MD −0.34; 95% CI −0.85 to 0.18). LMWH also significantly increased the bleeding events (RR 3.82; 95% CI 1.81–8.08). LMWH appears to reduce 28-day mortality and APACHE II score among septic patients. Bleeding complications should be monitored during the LMWH treatment. As for limited data about LMWH and sepsis in the English literature, only trials published in the Chinese were included in the meta-analysis. PMID:27181297

  5. Incidences of Deep Vein Thrombosis and Pulmonary Embolism after Total Knee Arthroplasty Using a Mechanical Compression Device with and without Low-Molecular-Weight Heparin

    PubMed Central

    Park, Sin Hyung; Ahn, Joong Hyeon; Park, Yong Bok; Lee, Sun Geun

    2016-01-01

    Purpose To investigate the incidence of thromboembolic events and complications related to bleeding after total knee arthroplasty (TKA) with a mechanical compression device alone or in combination with low-molecular-weight heparin (LMWH). Materials and Methods A total of 489 TKA patients (776 knees) were retrospectively reviewed for the incidence of thromboembolic events and complications related to bleeding. While 233 patients (354 knees) were treated with a mechanical compressive device without LMWH, 256 patients (422 knees) were treated with the mechanical compressive device along with LMWH. Results The incidences of deep vein thrombosis (DVT) and pulmonary embolism (PE) were 15 of 375 knees (4.0%) and 5 of 375 knees (1.3%), respectively, in the group that used only a mechanical compressive device, and 14 of 401 knees (3.4%) and 5 of 401 knees (1.2%), respectively, in the group that used the mechanical compressive device with LMWH. There was no significant difference between the two groups (p=0.125 and p=0.146, respectively). The postoperative hemovac drainage amount was 635±57 mL in the group with a mechanical compressive device only and 813±84 mL in the group with the device and LMWH; therefore, the amount of drainage was significantly greater in the latter group (p=0.013). Conclusions Mechanical compression alone for prophylaxis against DVT and PE after TKA can be an attractive option in Korean patients. PMID:27595075

  6. Ion exchange chromatographic separation and isolation of oligosaccharides of intact low-molecular-weight heparin for the determination of their anticoagulant and anti-inflammatory properties.

    PubMed

    Shastri, Madhur D; Johns, Cameron; Hutchinson, Joseph P; Khandagale, Manish; Patel, Rahul P

    2013-07-01

    It is well known that enoxaparin, a widely used anticoagulant and low-molecular-weight heparin containing a large number of oligosaccharides, possesses anti-inflammatory activity. Whilst enoxaparin has shown promising results in various inflammatory disorders, some of its oligosaccharides have anti-inflammatory properties and others increase the risk of bleeding due to their anticoagulant effects. The aim of this study was to develop an effective ion exchange chromatographic (IC) technique which allows the separation, isolation and, consequently, the identification of different oligosaccharides of enoxaparin with or without anticoagulant activity. The developed method utilises a semi-preparative CarboPac PA100 (9 × 250 mm) ion exchange column with sodium chloride gradient elution and UV detection at 232 nm. The method successfully resolved enoxaparin into more than 30 different peaks. IC-derived oligosaccharides with high, moderate, low or no anticoagulant activity were identified using an anti-factor Xa assay. The anti-inflammatory activity of selected oligosaccharides was investigated using the Griess assay. Using this technique, the oligosaccharides of enoxaparin with low or no anticoagulant activity, whilst exhibiting significant anti-inflammatory activity, could be fractionated. This technique can provide a platform to identify the oligosaccharides which are devoid of significant anticoagulant activity and are responsible for the therapeutic effects of enoxaparin that have been observed in various inflammatory conditions. PMID:23712644

  7. Biomedical Application of Low Molecular Weight Heparin/Protamine Nano/Micro Particles as Cell- and Growth Factor-Carriers and Coating Matrix

    PubMed Central

    Ishihara, Masayuki; Kishimoto, Satoko; Takikawa, Makoto; Hattori, Hidemi; Nakamura, Shingo; Shimizu, Masafumi

    2015-01-01

    Low molecular weight heparin (LMWH)/protamine (P) nano/micro particles (N/MPs) (LMWH/P N/MPs) were applied as carriers for heparin-binding growth factors (GFs) and for adhesive cells including adipose-derived stromal cells (ADSCs) and bone marrow-derived mesenchymal stem cells (BMSCs). A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter). LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D) cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures. PMID:26006248

  8. Heparin-induced platelet aggregation (H-IPA): dose/response relationship for two low molecular weight (LMW) heparin preparations (CY 216 and CY 222)

    SciTech Connect

    Brace, L.D.; Fareed, J.

    1986-03-01

    The authors have previously demonstrated that heparin and a LMW heparin derivative (PK 10169) causes platelet aggregation in a dose-dependent manner that can be inhibited by antagonists of the thromboxane pathway. Using fractions of these agents separated on the basis of molecular weight (MW) by gel permeation chromatography, the authors showed that H-IPA was directly dependent upon the MW of the agents tested. In order to further examine this MW dependence, the authors tested two other LMW heparin preparations, CY 216 and CY 222 and subfractions of these agents separated on the basis of MW. Citrate anticoagulated whole blood was drawn from drug-free normal healthy donors whose platelets aggregated when heparin was added to their platelet-rich plasma (PRP). PRP was prepared, various concentrations of the agents or their subfractions were added and aggregation was monitored for 40 minutes at 37/sup 0/C. The results demonstrate that like heparin and PK 10169, CY 216 and CY 222 caused platelet aggregation in a dose and MW dependent manner. Fractions with MW less than 2500 daltons caused aggregation only at concentrations exceeding the therapeutic range of the agents. The authors conclude that the ability to cause H-IPA is an inherent property of heparin and its fractions.

  9. pH-responsive thiolated chitosan nanoparticles for oral low-molecular weight heparin delivery: in vitro and in vivo evaluation.

    PubMed

    Fan, Bo; Xing, Yang; Zheng, Ying; Sun, Chuan; Liang, Guixian

    2016-01-01

    The aim of present study was to investigate a pH-responsive and mucoadhesive nanoparticle system for oral bioavailability enhancement of low-molecular weight heparin (LMWH). The thioglycolic acid (TGA) was first covalently attached to chitosan (CS) with 396.97 ± 54.54 μmol thiol groups per gram of polymer and then the nanoparticles were prepared with thiolated chitosan (TCS) and pH-sensitive polymer hydroxypropyl methylcellulose phthalate (HPMCP) by ionic cross-linking method. The obtained nanoparticles were characterized for the shape, particle size, zeta potential, drug entrapment efficiency and loading capacity. In vitro results revealed the acid stability of pH-responsive nanoparticles, which had a significant control over LMWH release and could effectively protect entrapped drugs in simulated gastric conditions. By the attachment of the thiol ligand, an improvement of permeation-enhancing effect on freshly excised carp intestine (1.86-fold improvement) could be found. The mucoadhesive properties were evaluated using fluorescently labeled TCS or CS nanoparticles. As compared with the controls, a significant improvement of mucoadhesion on rat intestinal mucosa was observed in TCS/HPMCP nanoparticles via confocal laser scanning microscopy. The activated partial thromboplastin time (APTT) was significantly prolonged and an increase in the oral bioavailability of LMWH was turned out to be pronounced after oral delivered LMWH-loaded TCS/HPMCP nanoparticles in rats, which suggested enhanced anticoagulant effects and improved absorption of LMWH. In conclusion, pH-responsive TCS/HPMCP nanoparticles hold promise for oral delivery of LMWH. PMID:24865290

  10. Hemostasis during low molecular weight heparin anticoagulation for continuous venovenous hemofiltration: a randomized cross-over trial comparing two hemofiltration rates

    PubMed Central

    2009-01-01

    Introduction Renal insufficiency increases the half-life of low molecular weight heparins (LMWHs). Whether continuous venovenous hemofiltration (CVVH) removes LMWHs is unsettled. We studied hemostasis during nadroparin anticoagulation for CVVH, and explored the implication of the endogenous thrombin potential (ETP). Methods This cross-over study, performed in a 20-bed teaching hospital ICU, randomized non-surgical patients with acute kidney injury requiring nadroparin for CVVH to compare hemostasis between two doses of CVVH: filtrate flow was initiated at 4 L/h and converted to 2 L/h after 60 min in group 1, and vice versa in group 2. Patients received nadroparin 2850 IU i.v., followed by 380 IU/h continuously in the extracorporeal circuit. After baseline sampling, ultrafiltrate, arterial (art) and postfilter (PF) blood was taken for hemostatic markers after 1 h, and 15 min, 6 h, 12 h and 24 h after converting filtrate flow. We compared randomized groups, and 'early circuit clotting' to 'normal circuit life' groups. Results Fourteen patients were randomized, seven to each group. Despite randomization, group 1 had higher SOFA scores (median 14 (IQR 11-15) versus 9 (IQR 5-9), p = 0.004). Anti-Xa art activity peaked upon nadroparin bolus and declined thereafter (p = 0.05). Anti-Xa PF did not change in time. Anti-Xa activity was not detected in ultrafiltrate. Medians of all anti-Xa samples were lower in group 1 (anti-Xa art 0.19 (0.12-0.37) vs. 0.31 (0.23-0.52), p = 0.02; anti-Xa PF 0.34 (0.25-0.44) vs. 0.51 (0.41-0.76), p = 0.005). After a steep decline, arterial ETPAUC tended to increase (p = 0.06), opposite to anti-Xa, while postfilter ETPAUC increased (p = 0.001). Median circuit life was 24.5 h (IQR 12-37 h). Patients with 'short circuit life' had longer baseline prothrombin time (PTT), activated thromboplastin time (aPTT), lower ETP, higher thrombin-antithrombin complexes (TAT) and higher SOFA scores; during CVVH, anti-Xa, and platelets were lower; PTT, aPTT, TAT

  11. Novel, Precise, Accurate Ion-Pairing Method to Determine the Related Substances of the Fondaparinux Sodium Drug Substance: Low-Molecular-Weight Heparin.

    PubMed

    Deshpande, Amol A; Madhavan, P; Deshpande, Girish R; Chandel, Ravi Kumar; Yarbagi, Kaviraj M; Joshi, Alok R; Moses Babu, J; Murali Krishna, R; Rao, I M

    2016-01-01

    Fondaparinux sodium is a synthetic low-molecular-weight heparin (LMWH). This medication is an anticoagulant or a blood thinner, prescribed for the treatment of pulmonary embolism and prevention and treatment of deep vein thrombosis. Its determination in the presence of related impurities was studied and validated by a novel ion-pair HPLC method. The separation of the drug and its degradation products was achieved with the polymer-based PLRPs column (250 mm × 4.6 mm; 5 μm) in gradient elution mode. The mixture of 100 mM n-hexylamine and 100 mM acetic acid in water was used as buffer solution. Mobile phase A and mobile phase B were prepared by mixing the buffer and acetonitrile in the ratio of 90:10 (v/v) and 20:80 (v/v), respectively. Mobile phases were delivered in isocratic mode (2% B for 0-5 min) followed by gradient mode (2-85% B in 5-60 min). An Evaporative Light Scattering Detector (ELSD) was connected to the LC system to detect the responses of chromatographic separation. Further, the drug was subjected to stress studies for acidic, basic, oxidative, photolytic, and thermal degradations as per ICH guidelines and the drug was found to be labile in acid, base hydrolysis, and oxidation, while stable in neutral, thermal, and photolytic degradation conditions. The method provided linear responses over the concentration range of the LOQ to 0.30% for each impurity with respect to the analyte concentration of 12.5 mg/mL, and regression analysis showed a correlation coefficient value (r(2)) of more than 0.99 for all the impurities. The LOD and LOQ were found to be 1.4 µg/mL and 4.1 µg/mL, respectively, for fondaparinux. The developed ion-pair method was validated as per ICH guidelines with respect to accuracy, selectivity, precision, linearity, and robustness. PMID:27110496

  12. Monitoring Low Molecular Weight Heparins at Therapeutic Levels: Dose-Responses of, and Correlations and Differences between aPTT, Anti-Factor Xa and Thrombin Generation Assays

    PubMed Central

    Thomas, Owain; Lybeck, Emanuel; Strandberg, Karin; Tynngård, Nahreen; Schött, Ulf

    2015-01-01

    Background Low molecular weight heparins (LMWH’s) are used to prevent and treat thrombosis. Tests for monitoring LMWH’s include anti-factor Xa (anti-FXa), activated partial thromboplastin time (aPTT) and thrombin generation. Anti-FXa is the current gold standard despite LMWH’s varying affinities for FXa and thrombin. Aim To examine the effects of two different LMWH’s on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests’ concordance. Method Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU)/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR) and Hemochron Jr (HCJ)) and an optical plasma method using two different reagents (ActinFSL and PTT-Automat). Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP) was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents. Results Methods’ mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11) and 69s (SD 14) for enoxaparin and between 101s (SD 21) and 140s (SD 28) for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62–0.87), whereas the other aPTT methods had similar correlation coefficients (Rs0.80–0.92). Conclusions aPTT displays a linear dose-respone to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa’s present gold standard status. Thrombin generation with tissue factor-rich activator is

  13. Does Use of Low-Molecular-Weight Heparin during Pregnancy Influence the Risk of Prolonged Labor: A Population-Based Cohort Study

    PubMed Central

    Sandström, Anna; Cnattingius, Sven; Wikström, Anna-Karin

    2015-01-01

    Background The use of low-molecular-weight heparins (LMWHs) during pregnancy is increasing. In vitro studies and small clinical studies support the hypothesis that LMWH treatment during pregnancy may reduce duration of labor. The aim of this study was to investigate if use of LMWH is associated with a reduced risk of diagnosis of prolonged labor, after taking maternal, fetal and other delivery characteristics into account. Methods and Findings A population-based cohort study from the Swedish Medical Birth Register from April 2006 through December 2011. We identified 514 875 term (≥37 weeks) deliveries of live singleton infants in cephalic presentation with spontaneous or induced onsets of labor. The Birth Register was linked to the Prescribed Drug Register to retrieve information on dispensed LMWH during pregnancy and to the Patient Register for information on underlying diagnosis for use of LMWH. Diagnosis of prolonged labor in the Birth Register was retrieved from diagnosis at discharge from the delivery hospital. The risk of diagnosis of prolonged labor in relation to treatment with LMWH was assessed using logistic regression analysis to estimate unadjusted and adjusted odds ratios. A total of 5 275 (1.0%) of the pregnant women used LMWH. The absolute risk of diagnosis of prolonged labor for nulliparous women was 19.9% among women using LMWH in third trimester, and 21.2% in women without use of LMWH. For parous women the corresponding absolute risks were 4.3% and 4.7%, respectively. Compared to nulliparous women without use of LMWH, nulliparous women with LMWH during third trimester had an odds ratio (OR) of 0.92 (95% CI 0.81–1.05, p-value: 0.051) for diagnosis of prolonged labor in unadjusted analyses and after adjustments for maternal characteristics, gestational age and epidural analgesia the OR was 1.00 (95% CI 0.87–1.15, p-value: 0.673). Parous women treated with LMWH in third trimester presented the same pattern, unadjusted OR for diagnosis of

  14. Novel, Precise, Accurate Ion-Pairing Method to Determine the Related Substances of the Fondaparinux Sodium Drug Substance: Low-Molecular-Weight Heparin

    PubMed Central

    Deshpande, Amol A.; Madhavan, P.; Deshpande, Girish R.; Chandel, Ravi Kumar; Yarbagi, Kaviraj M.; Joshi, Alok R.; Moses Babu, J.; Murali Krishna, R.; Rao, I. M.

    2016-01-01

    Fondaparinux sodium is a synthetic low-molecular-weight heparin (LMWH). This medication is an anticoagulant or a blood thinner, prescribed for the treatment of pulmonary embolism and prevention and treatment of deep vein thrombosis. Its determination in the presence of related impurities was studied and validated by a novel ion-pair HPLC method. The separation of the drug and its degradation products was achieved with the polymer-based PLRPs column (250 mm × 4.6 mm; 5 μm) in gradient elution mode. The mixture of 100 mM n-hexylamine and 100 mM acetic acid in water was used as buffer solution. Mobile phase A and mobile phase B were prepared by mixing the buffer and acetonitrile in the ratio of 90:10 (v/v) and 20:80 (v/v), respectively. Mobile phases were delivered in isocratic mode (2% B for 0–5 min) followed by gradient mode (2–85% B in 5–60 min). An Evaporative Light Scattering Detector (ELSD) was connected to the LC system to detect the responses of chromatographic separation. Further, the drug was subjected to stress studies for acidic, basic, oxidative, photolytic, and thermal degradations as per ICH guidelines and the drug was found to be labile in acid, base hydrolysis, and oxidation, while stable in neutral, thermal, and photolytic degradation conditions. The method provided linear responses over the concentration range of the LOQ to 0.30% for each impurity with respect to the analyte concentration of 12.5 mg/mL, and regression analysis showed a correlation coefficient value (r2) of more than 0.99 for all the impurities. The LOD and LOQ were found to be 1.4 µg/mL and 4.1 µg/mL, respectively, for fondaparinux. The developed ion-pair method was validated as per ICH guidelines with respect to accuracy, selectivity, precision, linearity, and robustness. PMID:27110496

  15. Effects of atorvastatin combined with low-molecular-weight heparin on plasma inflammatory cytokine level and pulmonary pathophysiology of rats with sepsis

    PubMed Central

    Jing, Fei; Li, Ming; Ren, Hongsheng; Zhang, Jitian; Yao, Qingchun; Chu, Yufeng; Wang, Chunting

    2016-01-01

    The aim of the present study was to investigate the effect of atorvastatin combined with low-molecular-weight heparin (LMWH) on plasma early inflammatory cytokine levels as well as pulmonary pathophysiology of rats with sepsis. A total of 122 rats were randomly divided into five groups including the sham operation group (n=10), CLP group (n=10), atorvastatin group (n=34, 20 mg/kg/day), LMWH group (n=34, 100 IU/kg/day), and atorvastatin combined with LMWH group (n=34). Blood samples from 6 rats in each group were collected to detect TNF-α, IL-1β and HMGB1 concentration in plasma by linked immunosorbent assay at baseline and postoperatively at 4, 8, 12 and 24 h. Pulmonary pathophysiology was observed postoperatively at 24 h. The remaining 10 rats in each group were used to calculate the 7-day cumulative mortality rate. Compared to the sham operation group, the scores in CLP were greater than those of the sham operation group (P<0.05). Compared to the CLP group, the sepsis severity scores of the atorvastatin, LMWH, and atorvastatin combined with LMWH groups decreased gradually. Significant difference was detected in the four groups (P<0.05 0.01). Compared to the sham operation group, at 4, 8, 12 and 24 h, the TNF-α, IL-1β and HMGB1 levels in plasma in CLP increased significantly (P<0.01). Compared to the CLP group, the TNF-α, IL-1β and HMGB1 levels of plasma in other groups decreased gradually, and there was a significant difference in the four groups (P<0.01). At 24 h post operation, compared to the sham operation group, the damage of pulmonary pathophysiology in CLP was more severe. Compared to the CLP group, the damage of pulmonary pathophysiology in other groups was slight. Compared to the CLP group, the 7-day cumulative mortality rate in other groups decreased significantly (P<0.05). In conclusion, atorvastatin, combined with LMWH can decrease sepsis severity, plasma inflammatory cytokine levels, pulmonary pathophysiology, and the 7-day cumulative mortality

  16. Low molecular weight hydroxyethyl chitosan-prednisolone conjugate for renal targeting therapy: synthesis, characterization and in vivo studies.

    PubMed

    He, Xia-kai; Yuan, Zhi-xiang; Wu, Xiao-juan; Xu, Chao-qun; Li, Wan-yu

    2012-01-01

    To further evaluate the potential renal targeting profile of low molecular weight hydroxyethyl chitosan (LMWHC) we developed before, prednisolone (Pre) was conjugated with LMWHC by EDC/NHS chemistry to improve the therapeutic effect of glucocorticoids in vivo. The conjugate was denoted as LMWHC-Pre. The prednisolone content of the conjugate was determined by reversed-phase high-performance liquid chromatography (HPLC) with Kromasil C18 column. The results showed that the average coupling degree of prednisolone to LMWHC was 76.7±3.2 μg·mg(-1). The stability and physicochemical characterization of LMWHC-Pre under various conditions were also investigated. To study the fate of LMWHC-Pre after intravenous (i.v.) administration, fluorescein isothiocyanate (FITC) was coupled to the conjugate to explore the renal targeting efficacy. The in vivo results showed that significant amount of the conjugate was accumulated into the kidneys while negligible signal could be detected when the mixture of FITC-LMWHC and prednisolone was co-administered. The preliminary pharmacodynamics study of LMWHC-Pre showed that the conjugate could effectively alleviate the nephrotic syndrome of rats induced by minimal change nephrosis (MCN) model. Toxicity study also revealed that there was little glucocorticoid-induced osteoporosis by LMWHC-Pre upon 20 days of treatment. From this study, LMWHC-Pre may be employed as an effective potential drug candidate for the treatment of chronic renal disease. PMID:23227122

  17. Low Molecular Weight Hydroxyethyl Chitosan-Prednisolone Conjugate for Renal Targeting Therapy: Synthesis, Characterization and In Vivo Studies

    PubMed Central

    He, Xia-kai; Yuan, Zhi-xiang; Wu, Xiao-juan; Xu, Chao-qun; Li, Wan-yu

    2012-01-01

    To further evaluate the potential renal targeting profile of low molecular weight hydroxyethyl chitosan (LMWHC) we developed before, prednisolone (Pre) was conjugated with LMWHC by EDC/NHS chemistry to improve the therapeutic effect of glucocorticoids in vivo. The conjugate was denoted as LMWHC-Pre. The prednisolone content of the conjugate was determined by reversed-phase high-performance liquid chromatography (HPLC) with Kromasil C18 column. The results showed that the average coupling degree of prednisolone to LMWHC was 76.7±3.2 μg·mg-1. The stability and physicochemical characterization of LMWHC-Pre under various conditions were also investigated. To study the fate of LMWHC-Pre after intravenous (i.v.) administration, fluorescein isothiocyanate (FITC) was coupled to the conjugate to explore the renal targeting efficacy. The in vivo results showed that significant amount of the conjugate was accumulated into the kidneys while negligible signal could be detected when the mixture of FITC-LMWHC and prednisolone was co-administered. The preliminary pharmacodynamics study of LMWHC-Pre showed that the conjugate could effectively alleviate the nephrotic syndrome of rats induced by minimal change nephrosis (MCN) model. Toxicity study also revealed that there was little glucocorticoid-induced osteoporosis by LMWHC-Pre upon 20 days of treatment. From this study, LMWHC-Pre may be employed as an effective potential drug candidate for the treatment of chronic renal disease. PMID:23227122

  18. Utility of the clinical practice of administering thrombophilic screening and antithrombotic prophylaxis with low-molecular-weight heparin to healthy donors treated with G-CSF for mobilization of peripheral blood stem cells.

    PubMed

    Martino, Massimo; Luise, Francesca; Oriana, Vincenzo; Console, Giuseppe; Moscato, Tiziana; Mammì, Corrado; Messina, Giuseppe; Massara, Elisabetta; Irrera, Giuseppe; Piromalli, Angela; Lombardo, Vincenzo Trapani; Laganà, Carmelo; Iacopino, Pasquale

    2007-01-01

    The aim of the study was to verify the utility of the clinical practice of administering thrombophilic screening and antithrombotic prophylaxis with low-molecular-weight heparin to healthy donors receiving granulocyte colony-stimulating factor to mobilize peripheral blood stem cells. Thrombophilia screening comprised of testing for factor V Leiden G1691A, prothrombin G20210A, the thermolabile variant (C677T) of the methylene tetrahydrofolate reductase gene, protein C, protein S, factor VIII and homocysteine plasmatic levels, antithrombin III activity, and acquired activated protein C resistance. We investigated prospectively 72 white Italian healthy donors, 39 men and 33 women, with a median age of 42 years (range, 18-65). Five donors (6.9%) were heterozygous carriers of Factor V Leiden G1691A; two healthy donors had the heterozygous prothrombin G20210A gene mutation; C677T mutation in the methylene tetrahydrofolate reductase gene was present in 34 (47.2%) donors in heterozygous and in 7 donors (9.7%) in homozygous. Acquired activated protein C resistance was revealed in 8 donors of the study (11.1%). The protein C plasmatic level was decreased in 3 donors (4.2%); the protein S level was decreased in 7 donors (9.7%). An elevated factor VIII dosage was shown in 10 donors (13.9%) and hyperhomocysteinemia in 9 donors (12.5%). Concentration of antithrombin III was in the normal range for all study group donors. The factor V Leiden mutation was combined with the heterozygous prothrombin G20210A in 2 cases and with protein S deficiency in one case; 2 healthy donors presented an associated deficiency of protein C and protein S. Although none of these healthy subjects had a previous history of thrombosis, low-molecular-weight heparin was administered to all donors during granulocyte colony-stimulating factor administration to prevent thrombotic events. No donor experienced short or long-term thrombotic diseases after a median follow-up of 29.2 months. Our data do not

  19. Anticoagulant mechanism and platelet deaggregation property of a non-cytotoxic, acidic phospholipase A2 purified from Indian cobra (Naja naja) venom: inhibition of anticoagulant activity by low molecular weight heparin.

    PubMed

    Dutta, Sumita; Gogoi, Debananda; Mukherjee, Ashis K

    2015-03-01

    In the present study, anticoagulant and platelet modulating activities of an acidic phospholipase A2 (NnPLA2-I) purified from Indian cobra Naja naja venom was investigated. The NnPLA2-I displayed a mass of 15.2 kDa and 14,186.0 Da when analyzed by SDS-PAGE and MALDI-TOF-MS, respectively. Peptide mass fingerprinting analysis of the NnPLA2-I showed its significant similarity with phospholipase A2 enzymes purified from cobra venom. BLAST analysis of one tryptic peptide sequence of NnPLA2-I demonstrated putative conserved domains of the PLA2-like superfamily. The Km and Vmax values of NnPLA2-I toward hydrolysis of its most preferred substrate-phosphotidylcholine (PC)-were determined to be 0.72 mM and 29.3 μmol min(-1) mg(-1), respectively. The anticoagulant activity of NnPLA2-I was found to be higher than the anticoagulant activity of heparin/AT-III or warfarin. The histidine modifying reagent, monovalent and polyvalent antivenom differentially inhibited the catalytic and anticoagulant activities of NnPLA2-I. Low molecular weight heparin did not inhibit the catalytic and platelet deaggregation activity of NnPLA2-I, albeit its anticoagulant activity was significantly reduced. The NnPLA2-I showed a non-enzymatic, mixed inhibition of thrombin with a Ki value of 9.3 nM. Heparin significantly decreased, with an IC50 value of 15.23 mIU, the thrombin inhibitory activity of NnPLA2-I. The NnPLA2-I uniquely increased the amidolytic activity of FXa without influencing its prothrombin activating property. NnPLA2-I showed dose-dependent deaggregation of platelet rich plasma (PRP) and inhibited the collagen and thrombin-induced aggregation of PRP. However, deaggregation of washed platelets by NnPLA2-I demonstrated in presence of PC or platelet poor plasma. Alkylation of histidine residue of NnPLA2-I resulted in 95% and 21% reduction of its platelet deaggregation and platelet binding properties, respectively. NnPLA2-I did not show cytotoxicity against human glioblastoma U87MG cells

  20. Determination of the molecular weight of low-molecular-weight heparins by using high-pressure size exclusion chromatography on line with a triple detector array and conventional methods.

    PubMed

    Bisio, Antonella; Mantegazza, Alessandra; Vecchietti, Davide; Bensi, Donata; Coppa, Alessia; Torri, Giangiacomo; Bertini, Sabrina

    2015-01-01

    The evaluation of weight average molecular weight (Mw) and molecular weight distribution represents one of the most controversial aspects concerning the characterization of low molecular weight heparins (LMWHs). As the most commonly used method for the measurement of such parameters is high performance size exclusion chromatography (HP-SEC), the soundness of results mainly depends on the appropriate calibration of the chromatographic columns used. With the aim of meeting the requirement of proper Mw standards for LMWHs, in the present work the determination of molecular weight parameters (Mw and Mn) by HP-SEC combined with a triple detector array (TDA) was performed. The HP-SEC/TDA technique permits the evaluation of polymeric samples by exploiting the combined and simultaneous action of three on-line detectors: light scattering detectors (LALLS/RALLS); refractometer and viscometer. Three commercial LMWH samples, enoxaparin, tinzaparin and dalteparin, a γ-ray depolymerized heparin (γ-Hep) and its chromatographic fractions, and a synthetic pentasaccharide were analysed by HP-SEC/TDA. The same samples were analysed also with a conventional HP-SEC method employing refractive index (RI) and UV detectors and two different chromatographic column set, silica gel and polymeric gel columns. In both chromatographic systems, two different calibration curves were built up by using (i) γ-Hep chromatographic fractions and the corresponding Mw parameters obtained via HP-SEC/TDA; (ii) the whole γ-Hep preparation with broad Mw dispersion and the corresponding cumulative distribution function calculated via HP-SEC/TDA. In addition, also a chromatographic column calibration according to European Pharmacopoeia indication was built up. By comparing all the obtained results, some important differences among Mw and size distribution values of the three LMWHs were found with the five different calibration methods and with HP-SEC/TDA method. In particular, the detection of the lower

  1. Evaluation of a highly skin permeable low-molecular-weight protamine conjugated epidermal growth factor for novel burn wound healing therapy.

    PubMed

    Lee, Ji Hae; Bae, Il-Hong; Choi, Jin Kyu; Park, Jin Woo

    2013-11-01

    We evaluated the laser induced burn wound healing efficacy of a recombinant low-molecular-weight protamine conjugated epidermal growth factor (rLMWP-EGF). rLMWP-EGF was prepared by genetically combining LMWP with the N-terminal sequence of EGF; we obtained a homogeneous modified EGF without reduced biological activity. Because of the protein transduction domain of LMWP, rLMWP-EGF showed enhanced drug penetration across artificial skin constructs and excised mouse skin layers versus EGF and showed significantly improved burn wound healing efficacy, with accelerated wound closure and minimized eschar and scar formation, compared with EGF or no treatment. Histological examination also revealed that rLMWP-EGF permeated through the intact skin around the wound and facilitated residual epithelial cell proliferation in an integrated manner to reform an intact epidermis. Radiofrequency microwound formation was effective for reducing large hypertrophic scars formed after severe laser burning by collagen remodeling but rLMWP-EGF did not show a meaningful synergistic effect in burn scar reduction. However, rLMWP-EGF was helpful for forming skin with a more normal appearance and texture. Thus, rLMWP-EGF demonstrated therapeutic potential as a novel topical burn wound healing drug with no obvious toxic effect. PMID:24018779

  2. [GOOD PLANNING PRACTICE IN PRECLINICAL AND CLINICAL STUDIES OF UNFRACTIONATED AND FRACTIONATED HEPARINS IN RUSSIA AS THE BASIS OF SAFE AND EFFECTIVE ANTICOAGULATION THERAPY].

    PubMed

    Gavrishina, E V; Dobrovolskii, A V; Niyazov, R R; Romodanovskii, D P; Vasil'ev, A N

    2015-01-01

    General principles of appropriate strategies for preclinical and clinical development of unfractionated and low-molecular-weight heparins and demonstration of their biosimilarity to corresponding reference medicinal products are provided. Demonstration of the biosimilarity of heparin-containing medicinal products constitutes the basis for their efficacy and safety during anticoagulation therapy. The main quality, safety, and efficacy characteristics of heparin products are described and the extent of non-clinical and clinical investigations necessary prior to drug marketing authorization are considered. PMID:27017700

  3. Rationale and design of a clinical trial of a low-molecular-weight heparin in preventing clinically important venous thromboembolism in medical patients: the prospective evaluation of dalteparin efficacy for prevention of venous thromboembolism in immobilized patients trial (the PREVENT study).

    PubMed

    Vaitkus, Paul T; Leizorovicz, A; Goldhaber, S Z

    2002-01-01

    The utility of low-molecular-weight heparin (LMWH) in the prophylaxis of venous thromboembolic disease has been examined using the surrogate endpoint of venographically identified thrombi. The largest portion of these thrombi were asymptomatic calf-vein thrombi. The clinical relevance of this observation is a matter of debate. The present study is designed to evaluate the impact of an LMWH on clinically important endpoints. The current study is a randomized, prospective, double-blinded, multicenter, multinational, controlled clinical trial comparing dalteparin with placebo in moderately high-risk hospitalized medical patients. A total of 3300 patients will be randomized to receive either 5,000 IU per day of dalteparin or placebo for 14 days. Patients will undergo appropriate evaluation for any symptomatic episodes and all patients will undergo a bilateral compression ultrasound (CUS) on day 21 to search for asymptomatic proximal thrombi. The primary endpoint is the combination of objectively confirmed symptomatic deep vein thrombi (DVT), fatal or non-fatal pulmonary emboli, all proximal DVT, and sudden death. This study will be the first study to examine clinically important endpoints in evaluating the effect of a LMWH in hospitalized medical patients. This study also is the first study to use CUS rather than venography in concordance with contemporary medical practice. This trial is thus designed to address this important question in a clinically relevant manner. PMID:12710842

  4. Prophylaxis of thrombosis with low-molecular-weight heparin (LMWH).

    PubMed

    Holzheimer, René G

    2004-03-30

    Deep vein thrombosis (DVT) and pulmonary embolism (PE) are a major cause of morbidity and mortality, affecting approximately 4 million people each year in the United States. The identification of risk factors for the development of DVT and PE helped to develop a system for risk stratification. The risk to develop a deep vein thrombosis has been estimated to be up to 80% in some populations without prophylaxis. In multiple studies LMWHs demonstrated to be efficient and safe for reduction of DVT of patients in general and visceral surgery, orthopedic surgery, and trauma. Three compounds have been studied best, e.g., dalteparin, enoxaparin, nadroparin, which may help to decide which type of LMWH to use. There is clearly an expanding role for LMWHs in gynecology, cancer, intensive care, patients with acute medical illness and bedridden patients. In summary, LMWHs have chemical, physical, and clinical similarities. They have greater bioavailability, longer half-lifes, more predictable pharmacological response, possible improved safety, and similar or greater efficacy compared with UH. However, the evaluation of clinical trials does not allow the determination of therapeutic equivalence due to different diagnostic methods, drug administration times, dose equivalencies, and outcome measurements The scoring of the quality of clinical trials for meta-analysis is problematic and it has been recommended to assess the methodological aspects individually. Despite clear evidence of effectiveness, deep vein thrombosis prophylaxis is underused. This has been recognized by law firms as evidenced by internet advertisement where patients are informed on the prevention of venous thromboembolism or economy class syndrome. "If you or a family member has been injured, contact a personal injury attorney today. Just fill out Injury.Board.com's on-line questionnaire and have a personal injury lawyer review your potential personal injury claim -- free of charge.". The medico legal implications of antithrombotic prophylaxis and treatment are well recognized. PMID:15096326

  5. Heparin induced thrombocytopenia management with bivalirudin.

    PubMed

    Meera, R; Rachel, D; Ramakrishnapillai, V; Vijayaraghavan, G

    2007-01-01

    We report a case of Heparin Induced Thrombocytopenia (HIT) following percutaneous coronary intervention. The case is unique in that thrombocytopenia occurred very early after heparin administration and responded well to a regime of bivalirudin-a direct thrombin inhibitor readily available in India. Heparin, Thrombocytopenia, Bivalirudin Acute HIT, occurring within few hours of heparin therapy have been reported in patients previously exposed to unfractionated heparin (UFH) or low molecular weight heparin (LMWH) 1. Prompt recognition of the condition and timely intervention with direct thrombin inhibitors, can result in salvaging patients from this potentially fatal complication. PMID:19126942

  6. Low molecular weight species in humic and fulvic fractions

    USGS Publications Warehouse

    Wilson, M.A.; Collin, P.J.; Malcolm, R.L.; Perdue, E.M.; Cresswell, P.

    1988-01-01

    Fourier transform solution 1H nuclear magnetic resonance (NMR) spectrometry with homogated water peak irradiation is a useful method for detecting low molecular weight substances in humic extracts. Succinate, acetate, methanol, formate, lactate and some aryl methoxyl compounds have been detected in extracts from a wide range of sources. In view of the controversy over whether low molecular weight substances are contaminants in humic extracts introduced by the concentration procedure, we report that some of these materials are not contaminants since 1H-NMR can be used to follow their formation from higher molecular weight species. ?? 1988.

  7. Degradable copolymer based on amphiphilic N-octyl-N-quatenary chitosan and low-molecular weight polyethylenimine for gene delivery

    PubMed Central

    Liu, Chengchu; Zhu, Qing; Wu, Wenhui; Xu, Xiaolin; Wang, Xiaoyu; Gao, Shen; Liu, Kehai

    2012-01-01

    Background Chitosan shows particularly high biocompatibility and fairly low cytotoxicity. However, chitosan is insoluble at physiological pH. Moreover, it lacks charge, so shows poor transfection. In order to develop a new type of gene vector with high transfection efficiency and low cytotoxicity, amphiphilic chitosan was synthesized and linked with low-molecular weight polyethylenimine (PEI). Methods We first synthesized amphiphilic chitosan – N-octyl-N-quatenary chitosan (OTMCS), then prepared degradable PEI derivates by cross-linking low-molecular weight PEI with amphiphilic chitosan to produce a new polymeric gene vector (OTMCS–PEI). The new gene vector was characterized by various physicochemical methods. We also determined its cytotoxicity and gene transfecton efficiency in vitro and in vivo. Results The vector showed controlled degradation. It was very stable and showed excellent buffering capacity. The particle sizes of the OTMCS–PEI/DNA complexes were around 150–200 nm with proper zeta potentials from 10 mV to 30 mV. The polymer could protect plasmid DNA from being digested by DNase I at a concentration of 2.25 U DNase I/μg DNA. Furthermore, they were resistant to dissociation induced by 50% fetal bovine serum and 1100 μg/mL sodium heparin. OTMCS–PEI revealed lower cytotoxicity, even at higher doses. Compared with PEI 25 KDa, the OTMCS–PEI/DNA complexes also showed higher transfection efficiency in vitro and in vivo. Conclusion OTMCS–PEI was a potential candidate as a safe and efficient gene vector for gene therapy. PMID:23071395

  8. Recent Developments in Low Molecular Weight Complement Inhibitors

    PubMed Central

    Qu, Hongchang; Ricklin, Daniel; Lambris, John D.

    2009-01-01

    As a key part of the innate immune system, complement plays an important role not only in defending invading pathogens but also in many other biological processes. Inappropriate or excessive activation of complement has been linked to many autoimmune, inflammatory, and neurodegenerative diseases, as well as ischemia-reperfusion injury and cancer. A wide array of low molecular weight complement inhibitors has been developed to target various components of the complement cascade. Their efficacy has been demonstrated in numerous in vitro and in vivo experiments. Though none of these inhibitors has reached the market so far, some of them have entered clinical trials and displayed promising results. This review provides a brief overview of the currently developed low molecular weight complement inhibitors, including short peptides and synthetic small molecules, with an emphasis on those targeting components C1 and C3, and the anaphylatoxin receptors. PMID:19800693

  9. Oral heparins.

    PubMed

    Hiebert, Linda M

    2002-01-01

    The antithrombotic drug heparin is administered parenterally and believed not effective orally. Oral heparin would be most suitable for long term administration, often required for the prevention of thrombosis. Following parenteral administration, heparin is taken up by endothelial cells. Our laboratory has shown that heparin is similarly taken up by endothelium following oral administration, despite low plasma heparin concentrations. In a twenty-four hour period, endothelial heparin concentrations are greatest within 15 minutes of oral dosing although plasma levels never exceed one percent of dose. Endothelial uptake accounts for a considerable amount of absorption if the total body endothelium is considered. In support of oral heparin absorption, we demonstrated a dose-dependent decrease in thrombosis incidence in a rat jugular vein model following single oral doses of unfractionated heparins (bovine and porcine) or low molecular weight heparins (reviparin, logiparin and ardeparin). Low molecular weight heparins were effective at lower doses than unfractionated heparins where a fifty percent reduction in thrombosis was observed with 0.025 mg/kg reviparin, 0.1 mg/kg logiparin, versus 7.5 mg/kg bovine unfractionated heparin. These studies support the work of others demonstrating measurable systemic changes following oral heparin administration and suggest that heparin may be effective when administered by the oral route. It also indicates that the presence of heparin in plasma likely reflects a much greater amount associated with endothelium. PMID:11934211

  10. Interactions between nattokinase and heparin/GAGs.

    PubMed

    Zhang, Fuming; Zhang, Jianhua; Linhardt, Robert J

    2015-12-01

    Nattokinase (NK) is a serine protease extracted from a traditional Japanese food called natto. Due to its strong fibrinolytic and thrombolytic activity, NK is regarded as a valuable dietary supplement or nutraceutical for the oral thrombolytic therapy. In addition, NK has been investigated for some other medical applications including treatment of hypertension, Alzheimer's disease, and vitreoretinal disorders. The most widely used clinical anticoagulants are heparin and low molecular weight heparins. The interactions between heparin and proteins modulate diverse patho-physiological processes and heparin modifies the activity of serine proteases. Indeed, heparin plays important roles in almost all of NK's potential therapeutically applications. The current report relies on surface plasmon resonance spectroscopy to examine NK interacting with heparin as well as other glycosaminoglycans (GAGs). These studies showed that NK is a heparin binding protein with an affinity of ~250 nM. Examination with differently sized heparin oligosaccharides indicated that the interaction between NK and heparin is chain-length dependent and the minimum size for heparin binding is a hexasaccharide. Studies using chemically modified heparin showed the 6-O-sulfo as well as the N-sulfo groups but not the 2-O-sulfo groups within heparin, are essential for heparin's interaction with NK. Other GAGs (including HS, DS, and CSE) displayed modest binding affinity to NK. NK also interfered with other heparin-protein interactions, including heparin's interaction with antithrombin and fibroblast growth factors. PMID:26412225

  11. Diffusion of low molecular weight siloxane from bulk to surface

    SciTech Connect

    Homma, H.; Kuroyagi, T.; Mirley, C.L.; Ronzello, J.; Boggs, S.A.

    1996-12-31

    Silicone-based materials for outdoor insulators have the advantage that low molecular weight (LMW) components migrate through the material and coat the surface, thereby restoring hydrophobicity over a period of hours. By measuring the infrared (IR) absorption of siloxane migrating to the silicone surface through a thin carbon coating, the aspect of the LMW siloxane migration was observed as a real time plot and the time constant of the migration was calculated. According to the time dependence of IR-absorbance, the migration mostly saturated within only 12 hours after the carbon coating was applied. Also, the time constant showed a dependence on the concentration of added filler in the silicone samples.

  12. Intramolecular Hydrogen Bonds in Low-Molecular-Weight Polyethylene Glycol.

    PubMed

    Kozlowska, Mariana; Goclon, Jakub; Rodziewicz, Pawel

    2016-04-18

    We used static DFT calculations to analyze, in detail, the intramolecular hydrogen bonds formed in low-molecular-weight polyethylene glycol (PEG) with two to five repeat subunits. Both red-shifted O-H⋅⋅⋅O and blue-shifting C-H⋅⋅⋅O hydrogen bonds, which control the structural flexibility of PEG, were detected. To estimate the strength of these hydrogen bonds, the quantum theory of atoms in molecules was used. Car-Parrinello molecular dynamics simulations were used to mimic the structural rearrangements and hydrogen-bond breaking/formation in the PEG molecule at 300 K. The time evolution of the H⋅⋅⋅O bond length and valence angles of the formed hydrogen bonds were fully analyzed. The characteristic hydrogen-bonding patterns of low-molecular-weight PEG were described with an estimation of their lifetime. The theoretical results obtained, in particular the presence of weak C-H⋅⋅⋅O hydrogen bonds, could serve as an explanation of the PEG structural stability in the experimental investigation. PMID:26864943

  13. Conformations of Low-Molecular-Weight Lignin Polymers in Water.

    PubMed

    Petridis, Loukas; Smith, Jeremy C

    2016-02-01

    Low-molecular-weight lignin binds to cellulose during the thermochemical pretreatment of biomass for biofuel production, which prevents the efficient hydrolysis of the cellulose to sugars. The binding properties of lignin are influenced strongly by the conformations it adopts. Here, we use molecular dynamics simulations in aqueous solution to investigate the dependence of the shape of lignin polymers on chain length and temperature. Lignin is found to adopt collapsed conformations in water at 300 and 500 K. However, at 300 K, a discontinuous transition is found in the shape of the polymer as a function of the chain length. Below a critical degree of polymerization, Nc =15, the polymer adopts less spherical conformations than above Nc. The transition disappears at high temperatures (500 K) at which only spherical shapes are adopted. An implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures. PMID:26763657

  14. Dairy Wastewater Treatment Using Low Molecular Weight Crab Shell Chitosan

    NASA Astrophysics Data System (ADS)

    Geetha Devi, M.; Dumaran, Joefel Jessica; Feroz, S.

    2012-08-01

    The investigation of possible use of low molecular weight crab shell chitosan (MW 20 kDa) in the treatment of dairy waste water was studied. Various experiments have been carried out using batch adsorption technique to study the effects of the process variables, which include contact time, stirring speed, pH and adsorbent dosage. Treated effluent characteristics at optimum condition showed that chitosan can be effectively used as adsorbent in the treatment of dairy wastewater. The optimum conditions for this study were at 150 mg/l of chitosan, pH 5 and 50 min of mixing time with 50 rpm of mixing speed. Chitosan showed the highest performance under these conditions with 79 % COD, 93 % turbidity and 73 % TSS reduction. The result showed that chitosan is an effective coagulant, which can reduce the level of COD, TSS and turbidity in dairy industry wastewater.

  15. Adsorption of low molecular weight halocarbons by montmorillonite

    SciTech Connect

    Estes, T.J.; Shah, R.V.; Vilker, V.L. )

    1988-04-01

    Montmorillonite clay from Clay Spur, WY, was found to adsorb several low molecular weight, hydrophobic halocarbons from aqueous solution at sub-parts-per-million levels. The halocarbons studied were trichloroethylene, tetrachloroethylene, hexachloroethane, and dibromochloropropane. When the montmorillonite was treated with sodium citrate-bicarbonate-dithionite (CBD), it adsorbed higher levels of halocarbons than the untreated clay. In addition, the CBD-treated clay exhibited a maximum in halocarbon adsorption around pH 4, while untreated clay showed little variation in adsorption over the pH range 2-10. Adsorption of trichloroethylene was inhibited by low concentrations of sodium chloride (0.01 M or greater) in solution. Aging the CBD-treated clay in water decreased its capacity to adsorb trichloroethylene. Desorption studies showed that the sorption of tetrachloroethylene to CBD-treated clay is an irreversible process when compared to sorption by fumed silica. The ability of montmorillonite to adsorb halocarbons and the instability of the clay in water are postulated to involve changes in the oxide surface coating on the clay.

  16. Association between cationic liposomes and low molecular weight hyaluronic acid.

    PubMed

    Gasperini, Antonio A M; Puentes-Martinez, Ximena E; Balbino, Tiago Albertini; Rigoletto, Thais de Paula; Corrêa, Gabriela de Sá Cavalcanti; Cassago, Alexandre; Portugal, Rodrigo Villares; de La Torre, Lucimara Gaziola; Cavalcanti, Leide P

    2015-03-24

    This work presents a study of the association between low molecular weight hyaluronic acid (16 kDa HA) and cationic liposomes composed of egg phosphatidylcholine (EPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). The cationic liposome/HA complexes were evaluated to determine their mesoscopic structure, average size, zeta potential, and morphology as a function of the amount of HA in the system. Small angle X-ray scattering results revealed that neighboring cationic liposomes either stick together after a partial coating of low concentration HA or disperse completely in excess of HA, but they never assemble as multilamellar vesicles. Cryo-transmission electron microscopy images confirm the existence of unilamellar vesicles and large aggregates of unilamellar vesicles for HA fractions up to 80% (w/w). High concentrations of HA (> 20% w/w) proved to be efficient for coating extruded liposomes, leading to particle complexes with sizes in the nanoscale range and a negative zeta potential. PMID:25730494

  17. Antiaging activity of low molecular weight peptide from Paphia undulate

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Cai, Bingna; Chen, Hua; Pan, Jianyu; Chen, Deke; Sun, Huili

    2013-05-01

    Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.

  18. Preparation and hemostatic property of low molecular weight silk fibroin.

    PubMed

    Lei, Caihong; Zhu, Hailin; Li, Jingjing; Feng, Xinxing; Chen, Jianyong

    2016-04-01

    Effective hemorrhage control becomes increasingly significant in today's military and civilian trauma, while the topical hemostats currently available in market still have various disadvantages. In this study, three low molecular weight silk fibroins (LMSF) were prepared through hydrolysis of silk fibroin in a ternary solvent system of CaCl2/H2O/EtOH solution at different hydrolysis temperatures. Fourier transform infrared spectroscopy analysis showed that the content of β sheet structure in the LMSF decreased with the increase in hydrolysis temperature. The results of thromboelastographic and activated partial thromboplastin time methods showed that the LMSF hydrolyzed at 50 °C can significantly strengthen the coagulation in blood and activate the intrinsic pathway of coagulation cascade. In the murine hepatic injury model, the LMSF hydrolyzed at 50 °C can promote the blood clotting and decrease the blood loss and bleeding time. Based on these results, it can be suggested that the developed LMSF has the excellent hemostatic effect and may be a promising material in clinical hemostatic application. PMID:26732018

  19. A low molecular weight proteinase inhibitor produced by T lymphocytes.

    PubMed Central

    Ganea, D; Teodorescu, M; Dray, S

    1986-01-01

    A low molecular weight (MW) proteinase inhibitor, between 6500 and 21,500 MW, appeared in the supernatant of rabbit spleen cells cultured at high density for 24 hr. The inhibitor inhibited the enzymatic activity of trypsin for both a high MW natural substrate, fibrinogen, and for a low MW artificial substrate, Chromozym TRY. The low MW proteinase inhibitor is protein in nature and is different, in terms of specificity for enzymes, MW and sensitivity to different physical or chemical treatments, from aprotinin, a low MW proteinase inhibitor (6500 MW) of bovine origin, and from the soybean trypsin inhibitor, a relatively high MW proteinase inhibitor (21,500 MW). The inhibitor was found in the supernatant of purified T cells but not B cells, and its production was increased in the presence of an optimal concentration of Con A. The possibility that this proteinase inhibitor has a role in the regulation of trypsin-like proteinases involved to the immune response remains to be investigated. Images Figure 4 PMID:2417942

  20. [Anaphylactic reactions to low-molecular weight chemicals].

    PubMed

    Nowak, Daria; Panaszek, Bernard

    2015-01-01

    Low-molecular weight chemicals (haptens) include a large group of chemical compounds occurring in work environment, items of everyday use (cleaning products, clothing, footwear, gloves, furniture), jewelry (earrings, bracelets), drugs, especially in cosmetics. They cause type IV hypersensitive reactions. During the induction phase of delayed-type hypersensitivity, haptens form complexes with skin proteins. After internalization through antigen presenting cells, they are bound to MHC class II molecules. Next, they are exposed against specific T-lymphocytes, what triggers activation of Th1 cells mainly. After repeating exposition to that hapten, during effector phase, Th1 induce production of cytokines affecting non-specific inflammatory cells. Usually, it causes contact dermatitis. However, occasionally incidence of immediate generalized reactions after contact with some kinds of haptens is noticed. A question arises, how the hapten does induce symptoms which are typical for anaphylaxis, and what contributes to amplification of this mechanism. It seems that this phenomenon arises from pathomechanism occurring in contact urticaria syndrome in which an anaphylactic reaction may be caused either by contact of sensitized skin with protein antigens, high-molecular weight allergens, or haptens. One of the hypotheses indicates the leading role of basophiles in this process. Their contact with haptens, may cause to release mediators of immediate allergic reaction (histamine, eicosanoids) and to produce cytokines corresponding to Th2 cells profile. Furthermore, Th17 lymphocytes secreting pro-inflammatory interleukin-17 might be engaged into amplifying hypersensitivity into immediate reactions and regulatory T-cells may play role in the process, due to insufficient control of the activity of effector cells. PMID:25661919

  1. Low molecular weight carboxylic acids in oxidizing porphyry copper tailings.

    PubMed

    Dold, Bernhard; Blowes, David W; Dickhout, Ralph; Spangenberg, Jorge E; Pfeifer, Hans-Rudolf

    2005-04-15

    The distribution of low molecular weight carboxylic acids (LMWCA) was investigated in pore water profiles from two porphyry copper tailings impoundments in Chile (Piuquenes at La Andina and Cauquenes at El Teniente mine). The objectives of this study were (1) to determine the distribution of LMWCA, which are interpreted to be the metabolic byproducts of the autotroph microbial community in this low organic carbon system, and (2) to infer the potential role of these acids in cycling of Fe and other elements in the tailings impoundments. The speciation and mobility of iron, and potential for the release of H+ via hydrolysis of the ferric iron, are key factors in the formation of acid mine drainage in sulfidic mine wastes. In the low-pH oxidation zone of the Piuquenes tailings, Fe(III) is the dominant iron species and shows high mobility. LMWCA, which occur mainly between the oxidation front down to 300 cm below the tailings surface at both locations (e.g., max concentrations of 0.12 mmol/L formate, 0.17 mmol/L acetate, and 0.01 mmol/L pyruvate at Piuquenes and 0.14 mmol/L formate, 0.14 mmol/L acetate, and 0.006 mmol/L pyruvate at Cauquenes), are observed at the same location as high Fe concentrations (up to 71.2 mmol/L Fe(II) and 16.1 mmol/L Fe(III), respectively). In this zone, secondary Fe(III) hydroxides are depleted. Our data suggest that LMWCA may influence the mobility of iron in two ways. First, complexation of Fe(III), through formation of bidentate Fe(III)-LMWCA complexes (e.g., pyruvate, oxalate), may enhance the dissolution of Fe(III) (oxy)hydroxides or may prevent precipitation of Fe(III) (oxy)hydroxides. Soluble Fe(III) chelate complexes which may be mobilized downward and convert to Fe(II) by Fe(III) reducing bacteria. Second, monodentate LMWCA (e.g., acetate and formate) can be used by iron-reducing bacteria as electron donors (e.g., Acidophilum spp.), with ferric iron as the electron acceptor. These processes may, in part, explain the low abundances

  2. Optimization of parameters for coverage of low molecular weight proteins

    PubMed Central

    Müller, Stephan A.; Kohajda, Tibor; Findeiß, Sven; Stadler, Peter F.; Washietl, Stefan; Kellis, Manolis; von Bergen, Martin

    2010-01-01

    Proteins with molecular weights of <25 kDa are involved in major biological processes such as ribosome formation, stress adaption (e.g., temperature reduction) and cell cycle control. Despite their importance, the coverage of smaller proteins in standard proteome studies is rather sparse. Here we investigated biochemical and mass spectrometric parameters that influence coverage and validity of identification. The underrepresentation of low molecular weight (LMW) proteins may be attributed to the low numbers of proteolytic peptides formed by tryptic digestion as well as their tendency to be lost in protein separation and concentration/desalting procedures. In a systematic investigation of the LMW proteome of Escherichia coli, a total of 455 LMW proteins (27% of the 1672 listed in the SwissProt protein database) were identified, corresponding to a coverage of 62% of the known cytosolic LMW proteins. Of these proteins, 93 had not yet been functionally classified, and five had not previously been confirmed at the protein level. In this study, the influences of protein extraction (either urea or TFA), proteolytic digestion (solely, and the combined usage of trypsin and AspN as endoproteases) and protein separation (gel- or non-gel-based) were investigated. Compared to the standard procedure based solely on the use of urea lysis buffer, in-gel separation and tryptic digestion, the complementary use of TFA for extraction or endoprotease AspN for proteolysis permits the identification of an extra 72 (32%) and 51 proteins (23%), respectively. Regarding mass spectrometry analysis with an LTQ Orbitrap mass spectrometer, collision-induced fragmentation (CID and HCD) and electron transfer dissociation using the linear ion trap (IT) or the Orbitrap as the analyzer were compared. IT-CID was found to yield the best identification rate, whereas IT-ETD provided almost comparable results in terms of LMW proteome coverage. The high overlap between the proteins identified with IT

  3. Synthesis and self-assembly of 1-deoxyglucose derivatives as low molecular weight organogelators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low molecular weight gelators are an important class of molecules. The supramolecular gels formed by carbohydrate derived low molecular weight gelators, are interesting soft materials that show great potential for many applications. Previously, we synthesized a series of methyl 4,6-O-benzylidene-a-D...

  4. Viscoelastic Behavior of Low Molecular Weight Sulfonated Polystyrene Ionomers

    NASA Astrophysics Data System (ADS)

    Zhao, Hongying

    Ionomers are those hydrophobic polymers having small amounts of bonded ionic groups. The introduction of the ionic groups into polymer chain produces large changes in the physical, mechanical and rheological properties of the parent polymer. Characterization of the effect of the ionic interactions on the rheology is complicated by the difficulty in separating effects due to molecular entanglements and the ionic interactions. In this study, low molecular weight (Mw=4000) sulfonated polystyrene (SPS) was used to study the dynamic and steady shear rheology of SPS ionomers. The polymer chain length used was far below the entanglement molecular weight of polystyrene and effects of molecular entanglements will be absent. Any polymer chain entanglements or lengthening behavior on the melt rheology should be due to the ionic interactions. Random SPS ionomers with two sulfonation levels were examined, 2.5 and 4.8 mol%, which corresponded, respectively, to one and two sulfonate groups per chain on average. The metal counterions was varied across the alkali metal series of the periodic table. Morphology of the ionomer was characterized by using small angle x-ray scattering (SAXS) analysis, and dynamic and steady shear measurements were performed to investigate rheological behavior of the ionomers. Glass transition temperatures of the ionomers increased with increasing ion concentration but were insensitive to cation used. The scattering peak in SAXS indicates the existence of the nanophase separated ionic clusters. The strong ionic nanophase persist up to very high temperatures and is not sensitive to the external stress. Time-temperature superposition (TTS) of G' worked reasonably well while TTS of G" failed for most ionomers. Ionic interactions increased the terminal relaxation time of the melts as much as seven orders of magnitude greater than the unentangled PS melt. The zero shear viscosity and first normal stress coefficients scaled with cq/a, where c was the

  5. Low molecular weight proteinuria in Chinese herbs nephropathy.

    PubMed

    Kabanda, A; Jadoul, M; Lauwerys, R; Bernard, A; van Ypersele de Strihou, C

    1995-11-01

    Urinary excretion of five low molecular weight proteins (LMWP) [beta 2-microglobulin (beta 2m), cystatin C (cyst C), Clara cell protein (CC16), retinol-binding protein (RBP) and alpha 1-microglobulin (alpha 1m)], albumin and N-acetyl-beta-D-glucosaminidase (NAG) were quantified in 16 patients who followed a weight reduction program which included Chinese herbs, which have been incriminated in the genesis of Chinese herbs nephropathy (CHN). An additional group of four patients transplanted for CHN were investigated. Urinary data were obtained for comparison purpose in five groups of proteinuric patients: two groups with normal serum creatinine (SCr) and glomerular albuminura [12 patients with diabetes mellitus and microalbuminuria (DN), 10 patients with primary nephrotic syndrome (NS)]; two groups with normal SCr and toxic nephropathy [6 patients with analgesic (AN), 9 patients with cadmium nephropathy (CdN)]; and one group of seven patients with glomerular diseases and increased SCr (GN). Patients were classified according to serum level S beta 2m to take into account the possibility of overflow proteinuria at S beta 2m > or = 5 mg/liter. Three patients (CHN0) with a S beta 2m < 5 mg/liter, had a normal urinary protein pattern including NAG and a normal S beta 2m. Eight patients (CHN1) with a S beta 2m < 5 mg/liter had various abnormalities of their urinary protein pattern. In four of them (CHN1a) only beta 2m, RBP and CC16 were increased while total proteinuria and SCr were normal. In the other four (CHN1b and c) albumin, cyst C, alpha 1m and NAG were also elevated, while total proteinuria and SCr were moderately raised. Five patients (CHN2) with a S beta 2m > or = 5 mg/liter had a markedly increased excretion of all LMWP, albumin and NAG (CHN1 vs. CHN2, P < 0.05) as well as a further increase in total proteinuria and SCr. The urinary LMWP/albumin concentration ratio was strikingly higher in CHN patients than in patients with glomerular albuminuria (CHN1 vs. DN

  6. Synthetic oligosaccharides as heparin-mimetics displaying anticoagulant properties.

    PubMed

    Avci, Fikri Y; Karst, Nathalie A; Linhardt, Robert J

    2003-01-01

    Heparin and low molecular weight heparins are major clinical anticoagulants and the drugs of choice for the treatment of deep venous thrombosis. The discovery of an antithrombin binding domain in heparin focused interest on understanding the mechanism of heparin's antithrombotic/ anticoagulant activity. Various heparin-mimetic oligosaccharides have been prepared in an effort to replace polydisperse heparin and low molecular weight heparins with a structurally-defined anticoagulant. The goal of attaining a heparin-mimetic with no unwanted side-effects has also provided motivation for these efforts. This article reviews structure-activity relationship (SAR) of structurally-defined heparin-mimetic oligosaccharides. PMID:14529394

  7. Low molecular weight PEI-appended polyesters as non-viral gene delivery vectors.

    PubMed

    Xun, Miao-Miao; Liu, Yan-Hong; Guo, Qian; Zhang, Ji; Zhang, Qin-Fang; Wu, Wan-Xia; Yu, Xiao-Qi

    2014-05-01

    Routine clinical implementation of human gene therapy requires safe and efficient gene delivery methods. Linear biodegradable polyesters with carbon-carbon double bonds are prepared from unsaturated diacids and diols. Subsequent appending of low molecular weight PEI by Michael addition gives target cationic polymers efficiently. Agarose gel retardation and fluorescence quenching assays show that these materials have good DNA binding ability and can completely retard plasmid DNA at weight ratio of 0.8. The formed polyplexes have appropriate sizes around 275 nm and zeta-potential values about +20-35 mV. The cytotoxicities of these polymers assayed by MTT are much lower than that of 25 kDa PEI. In vitro transfection toward 7402, HEK293 and U-2OS cells show that polymer P1 may give dramatically higher transfection efficiency (TE) than 25 kDa PEI, especially in U-2OS cells, suggesting that such polymer might be promising non-viral gene vectors. PMID:24681389

  8. Protection against cerebral malaria by the low-molecular-weight thiol pantethine.

    PubMed

    Penet, Marie-France; Abou-Hamdan, Mhamad; Coltel, Nicolas; Cornille, Emilie; Grau, Georges E; de Reggi, Max; Gharib, Bouchra

    2008-01-29

    We report that administration of the low-molecular-weight thiol pantethine prevented the cerebral syndrome in Plasmodium berghei ANKA-infected mice. The protection was associated with an impairment of the host response to the infection, with in particular a decrease of circulating microparticles and preservation of the blood-brain barrier integrity. Parasite development was unaffected. Pantethine modulated one of the early steps of the inflammation-coagulation cascade, i.e., the transbilayer translocation of phosphatidylserine at the cell surface that we demonstrated on red blood cells and platelets. In this, pantethine mimicked the inactivation of the ATP-binding-cassette transporter A1 (ABCA1), which also prevents the cerebral syndrome in this malaria model. However, pantethine acts through a different pathway, because ABCA1 activity was unaffected by the treatment. The mechanisms of pantethine action were investigated, using the intact molecule and its constituents. The disulfide group (oxidized form) is necessary to lower the platelet response to activation by thrombin and collagen. Thio-sensitive mechanisms are also involved in the impairment of microparticle release by TNF-activated endothelial cells. In isolated cells, the effects were obtained by cystamine that lacks the pantothenic moiety of the molecule; however, the complete molecule is necessary to protect against cerebral malaria. Pantethine is well tolerated, and it has already been administered in other contexts to man with limited side effects. Therefore, trials of pantethine treatment in adjunctive therapy for severe malaria are warranted. PMID:18195363

  9. Antioxidant activity of low molecular weight alginate produced by thermal treatment.

    PubMed

    Kelishomi, Zahra Habibi; Goliaei, Bahram; Mahdavi, Hossein; Nikoofar, Alireza; Rahimi, Mahmood; Moosavi-Movahedi, Ali Akbar; Mamashli, Fatemeh; Bigdeli, Bahareh

    2016-04-01

    By definition, antioxidants are molecules that inhibit the oxidation of other molecules. Therefore, such compounds have very important clinical roles. In this study alginate polymer was depolymerized by heat treatment. The resulting low molecular weight alginates were investigated by UV-visible spectroscopy, Viscometry, Dynamic light scattering and FT-IR spectroscopy techniques. Antioxidant properties of these heat products were studied by ABTS and superoxide radical scavenging assays. Results showed that heating caused breaks in the polymer chain and so generation of low molecular weight alginates. Antioxidant measurements confirmed antioxidant activity of alginate increased upon a decrease in molecular weight. Therefore, low molecular weight alginate produced by heating could be considered as a stronger antioxidant than alginate polymer. These products could be useful for industrial and biomedical applications. PMID:26593570

  10. Chemoprevention of Low-Molecular-Weight Citrus Pectin (LCP) in Gastrointestinal Cancer Cells

    PubMed Central

    Wang, Shi; Li, Pei; Lu, Sheng-Min; Ling, Zhi-Qiang

    2016-01-01

    Background & Aims: Low-molecular-weight citrus pectin (LCP) is a complex polysaccharide that displays abundant galactosyl (i.e., sugar carbohydrate) residues. In this study, we evaluated the anti-tumor properties of LCP that lead to Bcl-xL -mediated dampening of apoptosis in gastrointestinal cancer cells. Methods: We used AGS gastric cancer and SW-480 colorectal cancer cells to elucidate the effects of LCP on cell viability, cell cycle and apoptosis in cultured cells and tumor xenografts. Results: Significantly decreased cell viabilities were observed in LCP treated AGS and SW-480 cells (P<0.05). Cell cycle-related protein expression, such as Cyclin B1, was also decreased in LCP treated groups as compared to the untreated group. The AGS or SW-480 cell-line tumor xenografts were significantly smaller in the LCP treated group as compared the untreated group (P<0.05). LCP treatment decreased Galectin-3 (GAL-3) expression levels, which is an important gene in cancer metastasis that results in reversion of the epithelial-mesenchymal transition (EMT), and increased suppression of Bcl-xL and Survivin to promote apoptosis. Moreover, results demonstrated synergistic tumor suppressor activity of LCP and 5-FU against gastrointestinal cancer cells both in vivo and in vitro. Conclusions: LCP effectively inhibits the growth and metastasis of gastrointestinal cancer cells, and does so in part by down-regulating Bcl-xL and Cyclin B to promote apoptosis, and suppress EMT. Thus, LCP alone or in combination with other treatments has a high potential as a novel therapeutic strategy to improve the clinical therapy of gastrointestinal cancer. PMID:27194951

  11. Holographic recording medium employing a photoconductive layer and a low molecular weight microcrystalline polymeric layer

    NASA Technical Reports Server (NTRS)

    Gange, Robert Allen (Inventor)

    1977-01-01

    A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

  12. A global survey of low-molecular weight carbohydrates in lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentils contain a range of low-molecular weight carbohydrates (LMWC); however, those have not been well characterized. The objectives of this study were to (1) determine the concentrations of LMWC in lentils grown in six locations, and (2) identify any genetic and environmental effects on those LMWC...

  13. A global survey of low-molecular weight carbohydrates in lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentils contain a range of low-molecular weight carbohydrates (LMWC); however, they have not been well characterized. The objectives of this study were to (1) determine the concentrations of LMWC in lentils grown in different environments and (2) identify any genetic and environmental effects on tho...

  14. IR-MALDI OF LOW MOLECULAR WEIGHT COMPOUNDS USING A FREE ELECTRON LASER.

    EPA Science Inventory

    Initial experiments on infrared matrix-assisted laser desorption/ionization mass spectrometry (IR-MALDI) using a free electron laser in the analysis of low-molecular-weight compounds are reported. Mass spectra from samples of ethylenediaminetetraacetic acid (EDTA), nitrilotriacet...

  15. TOXICOLOGICAL HIGHLIGHT (REDOX REDUX: A CLOSER LOOK AT CONCEPTAL LOW MOLECULAR WEIGHT THIOLS)

    EPA Science Inventory

    Glutathione (GSH) is present as the most abundant low molecular weight thiol (LMWT) in virtually all mitochondria-bearing eucaryotic cells, often at millimolar concentrations (Meister, 1988). Functions of GSH include roles in DNA and protein synthesis, maintenance of cell membra...

  16. Determination of low molecular weight thiols using monobromobimane fluorescent labeling and high-performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Fahey, Robert C.; Newton, Gerald L.

    1988-01-01

    Methods are described for the preparation and high-performance liquid chromatography (HPLC) analysis of monobromobimane derivatives of low molecular weight thiols in extracts of biological samples. Typical problems encountered in the development and application of these methods are discussed. Analysis of mung bean extract is used as an example.

  17. Deviation from mean-field behavior in a low molecular weight critical polymer blend

    NASA Astrophysics Data System (ADS)

    Hair, D. W.; Hobbie, E. K.; Nakatani, A. I.; Han, C. C.

    1992-06-01

    A deviation from mean-field behavior is observed in the static susceptibility and correlation length measured with small angle neutron scattering as a function of temperature near the phase boundary of a relatively low molecular weight critical polymer mixture. The possibility of a fluctuation influenced crossover from mean-field to nonmean-field behavior is considered.

  18. Localization of small heat shock proteins to the higher plant endomembrane system. [Low-molecular-weight heat shock proteins

    SciTech Connect

    Helm, K.W.; Vierling, E. ); LaFayette, P.R.; Nagao, R.T.; Key, J.L. )

    1993-01-01

    Most eukaryotic cells respond to high temperature and other stresses with the production of heat shock proteins, which aid in cell survival. There are four major classes of heat shock proteins HSP90, HSP70, HSP60 and low-molecular weight HSP. The data from this research indicate that members of the low-molecular weight heat shock proteins are most likely resident endoplasmic reticulum (ER) proteins and may be similar in function to related low-molecular weight heat shock proteins in the cytoplasm. The low-molecular weight heat shock proteins, the HSP90 and the HSP70 all appear to localize to the endoplasmic reticulum. Since the ER-localized low-molecular weight heat shock proteins are physically separated from their counterparts in other cell compartments, investigations of the ER-localized heat shock proteins provides a simplified model system for determining the functions of low-molecular weight heat shock proteins in eukaryotes.

  19. Heparin centenary - an ever-young life-saving drug.

    PubMed

    Torri, Giangiacomo; Naggi, Annamaria

    2016-06-01

    On the centenary of the discovery of heparin, the International Journal of Cardiology agreed to publish a collection of mini reviews that summarize the historical development of this ever-young life-saving drug. The present articles deal not only with the historical milestones, but also with current and future perspectives regarding the development of heparin in terms of its structure, as well as on-going biochemical, biological and clinical research. Attention is focused on recent applications of heparin derivatives to non-anticoagulant or antithrombotic therapies, providing particular emphasis on their inhibitory activities, including their potential as anti-cancer agents. In the Chapter, entitled 'Recent innovations in the structural analysis of heparin', some recent technological advances are described for the problem of monitoring the purity and reproducibility of pharmaceutical heparin. These now permit sensitive detection of non-heparin impurities, as well as the detection of heparin from different animal sources, to be made in pharmaceutical heparin samples. In 'Past, present, and future perspectives of heparin in clinical settings and the role of impaired renal function', the author traces the history of heparin and the development of low molecular weight heparin, highlighting the large number of clinical trials in which it has been involved, and reviewing its efficacy among patients with impaired renal function. In the final chapter, 'Old and new applications of non-anticoagulant heparin', the authors survey some of the many non-anticoagulant activities of heparin and its derivatives, including glycol-split heparin, which has demonstrated promising activities in a wide-range of situations. PMID:27264864

  20. Role of laccase and low molecular weight metabolites from Trametes versicolor in dye decolorization.

    PubMed

    Moldes, Diego; Fernández-Fernández, María; Sanromán, M Ángeles

    2012-01-01

    The studies regarding decolorization of dyes by laccase may not only inform about the possible application of this enzyme for environmental purposes, but also may provide important information about its reaction mechanism and the influence of several factors that could be involved. In this paper, decolorization of crystal violet and phenol red was carried out with different fractions of extracellular liquids from Trametes versicolor cultures, in order to describe the role of laccase in this reaction. Moreover, the possible role of the low molecular weight metabolites (LMWMs) also produced by the fungus was evaluated. The results confirm the existence of a nonenzymatic decolorization factor, since the nonprotein fraction of the extracellular liquids from cultures of T. versicolor has shown decolorization capability. Several experiments were performed in order to identify the main compounds related to this ability, which are probably low molecular weight peroxide compounds. PMID:22566767

  1. [Chromatographic analysis of low molecular weight fraction of cerebrospinal fluid in children with acute neuroinfections].

    PubMed

    Alekseeva, L A; Shatik, S V; Sorokina, M N; Karasev, V V

    2002-05-01

    Low molecular-weight (oligopeptide) fraction of the cerebrospinal fluid was analyzed by high-performance reversed phase liquid chromatography in 30 children with bacterial and viral neuroinfections. The incidence and height of chromathoraphic peaks in bacterial meningitis depended on the disease etiology, stage, and severity. Qualitative and quantitative composition of low molecular-weight fraction of the liquor varied in patients with viral neuroinfections, depending on the severity of the cerebral parenchyma involvement. Differences in chromatographic profiles in complicated and uneventful course of neuroinfections indicate a possible damaging, protective, or regulatory effect of the liquor peptides. These data focus the attention on the role of oligopeptides in the genesis of neuroinfectious process, significance of search for peptide markers, their further isolation, identification, and development of test systems available for clinical application. PMID:12085699

  2. [Sequencing of low-molecular-weight DNA in blood plasma of irradiated rats].

    PubMed

    Vasilieva, I N; Bespalov, V G; Zinkin, V N; Podgornaya, O I

    2015-01-01

    Extracellular low-molecular-weight DNA in blood of irradiated rats was sequenced for the first time. The screening of sequences in the DDBJ database displayed homology of various parts of the rodent genome. Sequences of low-molecular-weight DNA in rat's plasma are enriched with G/C pairs and long interspersed elements relative to rat genome. DNA sequences in blood of rats irradiated at the doses of 8 and 100 Gy have marked distinctions. Data of sequencing of extracellular DNA from normal humans and with pathology were analyzed. DNA sequences of irradiated rats differ from the human ones by a wealth of long interspersed elements. This new knowledge lays the foundation for development of minimally invasive technologies of diagnosing the probability of pathology and controlling the adaptive resources of people in extreme environments. PMID:25958466

  3. Effects of low molecular weight chitosan (LMC-1) on shrimp preservation

    NASA Astrophysics Data System (ADS)

    Yu, Guang-Li; Wang, Yuan-Hong; Liu, Shu-Qing; Tian, Xue-Lin

    1996-06-01

    This study on the effects of low molecular weight chitosan (LMC-1) and shrimp preserving agents such as phytic acid (PA), sodium bisulfite (SB), and crustacean preservative (CP) on the preservation of shrimp ( Trachypenaeus curvirostris) and the bacteriostasis of LMC-1 showed that: (1) Different LMC-1 concentration has different bacteriostasis on E. coli, B. subtilis and S. aureau; (2) LMC-1 and CP are better than PA and SB for preserving the freshness of shrimp stored at 4 °C.

  4. Low molecular weight Neutral Boron Dipyrromethene (Bodipy) dyads for fluorescence-based neural imaging

    NASA Astrophysics Data System (ADS)

    Bai, Dan; Benniston, Andrew C.; Clift, Sophie; Baisch, Ulrich; Steyn, Jannetta; Everitt, Nicola; Andras, Peter

    2014-05-01

    The neutral low molecular weight julolidine-based borondipyrromethene (Bodipy) dyads JULBD and MJULBD were used for fast voltage-sensitive dye imaging of neurons in the crab stomatogastric ganglion. The fluorescence modulation of the dyads mirrors alterations in the membrane potential of the imaged neurons. The toxicity of the dyes towards the neurons is related to their structure in that methyl groups at the 3,5 positions results in reduced toxic effects.

  5. Western blotting of high and low molecular weight proteins using heat.

    PubMed

    Kurien, Biji T; Scofield, R Hal

    2015-01-01

    A method for the electrophoretic transfer of high and low molecular weight proteins to nitrocellulose membranes following sodium dodecyl sulfate (SDS) polyacrylamide gel is described here. The transfer was performed with heated (70-75 °C) normal transfer buffer from which methanol had been omitted. Complete transfer of high and low molecular weight antigens (molecular weight protein standards, a purified protein, and proteins from a human tissue extract) could be carried out in 10 min for a 7 % (0.75 mm) SDS polyacrylamide gel. For 10 and 12.5 % gels (0.75 mm) the corresponding time was 15 min. A complete transfer could be carried out in 20 min for 7, 10, and 12.5 % gels (1.5 mm gels). The permeability of the gel is increased by heat, such that the proteins trapped in the polyacrylamide gel matrix can be easily transferred to the membrane. The heat mediated transfer method was compared with a conventional transfer protocol, under similar conditions. The conventional method transferred minimal low molecular weight proteins while retaining most of the high molecular weight proteins in the gel. In summary, this procedure is particularly useful for the transfer of high molecular weight proteins, very rapid, and avoids the use of methanol. PMID:26044007

  6. Synthesis of the low molecular weight heat shock proteins in plants

    SciTech Connect

    Mansfield, M.A.; Key, J.L. )

    1987-08-01

    Heat shock of living tissue induces the synthesis of a unique group of proteins, the heat shock proteins. In plants, the major group of heat shock proteins has a molecular mass of 15 to 25 kilodaltons. Accumulation to these proteins to stainable levels has been reported in only a few species. To examine accumulation of the low molecular weight heat shock proteins in a broader range of species, two-dimensional electrophoresis was used to resolve total protein from the following species: soybean (Glycine max L. Merr., var Wayne), pea (Pisum sativum L., var Early Alaska), sunflower (Helianthus annuus L.), wheat (Triticum asetivum L.), rice (Oryza sativa L., cv IR-36), maize (Zea mays L.), pearl millet (Pennisetum americanum L. Leeke, line 23DB), and Panicum miliaceum L. When identified by both silver staining and incorporation of radiolabel, a diverse array of low molecular weight heat shock proteins was synthesized in each of these species. These proteins accumulated to significant levels after three hours of heat shock but exhibited considerable heterogeneity in isoelectric point, molecular weight, stainability, and radiolabel incorporation. Although most appeared to be synthesized only during heat shock, some were detectable at low levels in control tissue. Compared to the monocots, a higher proportion of low molecular weight heat shock proteins was detectable in control tissues from dicots.

  7. Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules.

    PubMed

    Cuecas, Alba; Cruces, Jorge; Galisteo-López, Juan F; Peng, Xiaojun; Gonzalez, Juan M

    2016-08-23

    Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50-80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature. PMID:27558730

  8. Antibody response to low-molecular-weight antigens of Aspergillus fumigatus in allergic bronchopulmonary aspergillosis.

    PubMed Central

    Kurup, V P; Greenberger, P A; Fink, J N

    1989-01-01

    Sera from patients with allergic bronchopulmonary aspergillosis (ABPA) or aspergilloma and normal sera were analyzed for specific antibodies by Western (immuno-) blotting with Aspergillus fumigatus antigens transferred electrophoretically onto polyvinylidene difluoride membranes. Western blot analysis demonstrated consistent reactivity of low-molecular-weight A. fumigatus antigens against ABPA sera but not against uncomplicated aspergilloma or normal sera. None of these low-molecular-weight components had any lectin-binding activity. Sera from patients with aspergilloma, however, frequently reacted with high-molecular-weight components of A. fumigatus. The majority of these high-molecular-weight antigenic components demonstrated concanavalin A-binding activity. The low-molecular-weight bands were discernible in Western blots with sera from all ABPA patients irrespective of disease activities, such as relapse, flare, or treatment. Antibodies detected by methods such as immunodiffusion or enzyme-linked immunosorbent assays demonstrated total antibody responses to most or all antigenic components, while Western blots demonstrated the reactivities of the individual components with the specific antibodies. Western blot analysis thus provided more information for immunodiagnosis of ABPA than other methods, especially when only crude antigens were available. Images PMID:2666440

  9. The evolution of anticoagulant therapy

    PubMed Central

    Franchini, Massimo; Liumbruno, Giancarlo M.; Bonfanti, Carlo; Lippi, Giuseppe

    2016-01-01

    Arterial and venous thromboembolism are leading causes of morbidity and mortality around the world. For almost 70 years, heparins (unfractionated heparin and low molecular weight heparins) and vitamin K antagonists have been the leading therapeutic medical options for the treatment and prevention of thromboembolic disorders. Nevertheless, the many limitations of these traditional anticoagulants have fuelled the search for novel agents over the past 15 years, and a new class of oral anticoagulants that specifically target activated factor X and thrombin has been developed and is now commercially available. In this narrative review, the evolution of anticoagulant therapy is summarised, with a focus on newer oral anticoagulants. PMID:26710352

  10. Synthesis and characterization of bioresorbable in situ crosslinkable ultra low molecular weight poly(lactide) macromer.

    PubMed

    Jabbari, Esmaiel; He, Xuezhong

    2008-01-01

    Reactive low molecular weight poly(L-lactide) (PLA) is required to produce in situ hardened scaffolds with fast rate of crosslinking, high crosslink density, and adequate mechanical strength. The objective of this work was to synthesize unsaturated ultra low molecular weight PLA (ULMW PLA) as an injectable in situ crosslinkable macromer for biomedical applications. Low molecular weight PLA was synthesized by ring-opening polymerization of L-lactide (LA) using diethylene glycol (DEG) as the initiator. The molar ratio of the LA to DEG ranged from 5 to 20. Non-solvents methanol, ether, and hexane were used for purification and fractionation. The PLA samples that were precipitated in methanol and ether had narrow distributions (PDI=1.2) and resulted in a powder with M(n) of 4.8 and a wax with M(n) of 3.6 kDa, respectively. The PLA sample in which the supernatant from ether was re-precipitated in hexane produced a viscous ULMW PLA with M(n) and PDI of 1.2 kDa and 1.2, respectively. The ULMW PLA was reacted with fumaryl chloride to produce unsaturated in situ crosslinkable poly(lactide fumarate) (PLAF) macromer. Porous scaffolds were produced after injection and in situ crosslinking of the PLAF macromer with NVP crosslinker in the presence of a porogen. New bone was formed in the scaffold when it was implanted in nude mice which demonstrated that the scaffold was osteoconductive. PLAF is potentially useful as a reactive macromer in fabrication of bioresorbable injectable in situ crosslinkable scaffolds for tissue regeneration. PMID:17597374

  11. Low molecular weight thermostable {beta}-D-glucosidase from Acidothermus cellulolyticus

    DOEpatents

    Himmel, M.E.; Tucker, M.P.; Adney, W.S.; Nieves, R.A.

    1995-07-11

    A purified low molecular weight {beta}-D-glucosidase is produced from Acidothermus cellulolyticus ATCC 43068. The enzyme is water soluble, possesses activity against pNP-{beta}-D-glucopyranoside, has a high of degree of stability toward heat, exhibits optimal temperature activity at about 65 C at a pH range of from about 2 to about 7, has an inactivation temperature of about 80 C at a pH range of from about 2 to about 7 and has a molecular weight of about 50.5--54.5 kD as determined by SDS-PAGE. 6 figs.

  12. Development of C3-Symmetric Tris-Urea Low-Molecular-Weight Gelators.

    PubMed

    Yamanaka, Masamichi

    2016-04-01

    This article describes recent developments in C3 -symmetric tris-urea low-molecular-weight gelators and their applications. The C3 -symmetric tris-ureas are excellent frameworks to form supramolecular polymers through noncovalent interactions. In organic solvents, hydrophobic tris-ureas form supramolecular gels. Amphiphilic tris-ureas form supramolecular gels in aqueous media. Functional supramolecular gels were prepared by introducing appropriate functional groups into the outer sphere of tris-ureas. Supramolecular hydrogels obtained from amphiphilic tris-ureas were used in the electrophoresis of proteins. These electrophoreses results showed several unique characteristics compared to typical electrophoreses results obtained using polyacrylamide matrices. PMID:26915980

  13. Low molecular weight thermostable .beta.-D-glucosidase from acidothermus cellulolyticus

    DOEpatents

    Himmel, Michael E.; Tucker, Melvin P.; Adney, William S.; Nieves, Rafael A.

    1995-01-01

    A purified low molecular weight .beta.-D-glucosidase is produced from Acidothermus cellulolyticus ATCC 43068. The enzyme is water soluble, possesses activity against pNP-.beta.-D-glucopyranoside, has a high of degree of stability toward heat, exhibits optimal temperature activity at about 65.degree. C. at a pH range of from about 2 to about 7, has an inactivation temperature of about 80.degree. C. at a pH range of from about 2 to about 7 and has a molecular weight of about 50.5-54.5 kD as determineded by SDS-PAGE.

  14. Low-molecular-weight inhibitors of NF-κB signalling pathways

    NASA Astrophysics Data System (ADS)

    Dolinnaya, N. G.; Kubareva, Elena A.; Kazanova, E. V.; Zigangirova, N. A.; Naroditsky, B. S.; Gintsburg, A. L.; Oretskaya, Tat'yana S.

    2008-11-01

    The nuclear factor κB (NF-κB) is a transcription factor involved in inducible expression of cellular genes playing a key role in cardiovascular pathologies, carcinogenesis, inflammatory and viral diseases. The review describes the stimuli and processes inducing NF-κB activation and the components of a signalling cascade that could constitute targets for NF-κB inhibition. The molecular action and properties of various low-molecular weight inhibitors aiming to prevent NF-κB activity are summarised.

  15. Total internal reflection ellipsometry and SPR detection of low molecular weight environmental toxins

    NASA Astrophysics Data System (ADS)

    Nabok, A. V.; Tsargorodskaya, A.; Hassan, A. K.; Starodub, N. F.

    2005-06-01

    The environmental toxins, such as herbicides simazine and atrazine, and T2 mycotoxin were registered with the optical methods of surface plasmon resonance (SPR) and recently developed total internal reflection ellipsometry (TIRE). The immune assay approach was exploited for in situ registration of the above low molecular weight toxins with specific antibodies immobilised onto the gold surface via (poly)allylamine hydrochloride layer using electrostatic self-assembly (ESA) technique. The comparison of two methods of SPR and TIRE shows a higher sensitivity of the latter.

  16. The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk.

    PubMed

    Cheema, M; Mohan, M S; Campagna, S R; Jurat-Fuentes, J L; Harte, F M

    2015-08-01

    The agreed biological function of the casein micelles in milk is to carry minerals (calcium, magnesium, and phosphorus) from mother to young along with amino acids for growth and development. Recently, native and modified casein micelles were used as encapsulating and delivery agents for various hydrophobic low-molecular-weight probes. The ability of modified casein micelles to bind certain probes may derive from the binding affinity of native casein micelles. Hence, a study with milk from single cows was conducted to further elucidate the association of hydrophobic molecules into native casein micelles and further understand their biological function. Hydrophobic and hydrophilic extraction followed by ultraperformance liquid chromatography-high resolution mass spectrometry analysis were performed over protein fractions obtained from size exclusion fractionation of raw skim milk. Hydrophobic compounds, including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin, showed strong association exclusively to casein micelles as compared with whey proteins, whereas hydrophilic compounds did not display any preference for their association among milk proteins. Further analysis using liquid chromatography-tandem mass spectrometry detected 42 compounds associated solely with the casein-micelles fraction. Mass fragments in tandem mass spectrometry identified 4 of these compounds as phosphatidylcholine with fatty acid composition of 16:0/18:1, 14:0/16:0, 16:0/16:0, and 18:1/18:0. These results support that transporting low-molecular-weight hydrophobic molecules is also a biological function of the casein micelles in milk. PMID:26074238

  17. Low-molecular-weight hydroxyacids in marine atmospheric aerosol: evidence of a marine microbial origin

    NASA Astrophysics Data System (ADS)

    Miyazaki, Y.; Sawano, M.; Kawamura, K.

    2014-08-01

    Lactic acid (LA) and glycolic acid (GA), which are low-molecular-weight hydroxyacids, were identified in the particle and gas phases within the marine atmospheric boundary layer over the western subarctic North Pacific. A major portion of LA (81%) and GA (57%) was present in the particulate phase, which is consistent with the presence of a hydroxyl group in these molecules leading to the low volatility of the compounds. The average concentration (±SD) of LA in more biologically influenced marine aerosols (33 ± 58 ng m-3) was substantially higher than that in less biologically influenced aerosols (11 ± 12 ng m-3). Over the oceanic region of phytoplankton blooms, the concentration of aerosol LA was comparable to that of oxalic acid, which was the most abundant diacid during the study period. A positive correlation was found between the LA concentrations in more biologically influenced aerosols and chlorophyll a in seawater (r2 = 0.56), suggesting an important production of aerosol LA possibly associated with microbial (e.g., lactobacillus) activity in seawater and/or aerosols. Our finding provides a new insight into the poorly quantified microbial sources of marine organic aerosols (OAs) because such low-molecular-weight hydroxyacids are key intermediates for OA formation.

  18. Low-molecular-weight hydroxyacids in marine atmospheric aerosol: evidence of a marine microbial origin

    NASA Astrophysics Data System (ADS)

    Miyazaki, Y.; Sawano, M.; Kawamura, K.

    2014-04-01

    Lactic acid (LA) and glycolic acid (GA), which are low-molecular-weight hydroxyacids, were identified in the particle and gas phases within the marine atmospheric boundary layer over the western subarctic North Pacific. Major portion of LA (81%) and GA (57%) were present in the particulate phase, which is consistent with the presence of a hydroxyl group in these molecules leading to the low volatility of the compounds. The average concentration of LA in more biologically influenced marine aerosols (average 33 ± 58 ng m-3) was substantially higher than that in less biologically influenced aerosols (average 11 ± 12 ng m-3). Over the oceacnic region of phytoplankton blooms, the concentration of aerosol LA was comparable to that of oxalic acid, which was the most abundant diacid during the study period. A positive correlation was found between the LA concentrations in more biologically influenced aerosols and chlorophyll a in seawater (r2 = 0.56), suggesting an important production of aerosol LA possibly associated with microbial (e.g., lactobacillus) activity in seawater and/or aerosols. Our finding provides a new insight into the poorly quantified microbial sources of marine organic aerosols (OA) because such low-molecular-weight hydroxyacids are key intermediates for OA formation.

  19. Study of Low Molecular Weight Impurities in Pluronic Triblock Copolymers using MALDI, Interaction Chromatography, and NMR

    NASA Astrophysics Data System (ADS)

    Helming, Z.; Zagorevski, D.; Ryu, C. Y.

    2014-03-01

    Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers are a group of commercial macromolecular amphiphilic surfactants that have been widely studied for their applications in polymer-based nanotechnology and drug-delivery. It has been well-established that the synthesis of commercial Pluronic triblocks results in low molecular weight ``impurities,'' which are generally disregarded in the applications and study of these polymers. These species have been shown to have significant effects on the rheological properties of the material, as well as altering the supramolecular ``micellar'' structures for which the polymers are most often used. We have isolated the impurities from the bulk Pluronic triblock using Interaction Chromatography (IC) techniques, and subjected them to analysis by H1 NMR and MALDI (Matrix-Assisted Laser Desorption Ionization) Mass Spectrometry to identify relative block composition and molecular weight information. We report significant evidence of at least two polymeric components: a low-molecular-weight homopolymer of poly(ethylene oxide) and a ``blocky'' copolymer of both poly(ethylene oxide) and poly(propylene oxide). This has significant implications, not only for the applied usage of Pluronic triblock copolymers, but for the general scientific acceptance of the impurities and their effects on Pluronic micelle and hydrogel formation.

  20. Laser-based methods for the analysis of low molecular weight compounds in biological matrices.

    PubMed

    Kiss, András; Hopfgartner, Gérard

    2016-07-15

    Laser-based desorption and/or ionization methods play an important role in the field of the analysis of low molecular-weight compounds (LMWCs) because they allow direct analysis with high-throughput capabilities. In the recent years there were several new improvements in ionization methods with the emergence of novel atmospheric ion sources such as laser ablation electrospray ionization or laser diode thermal desorption and atmospheric pressure chemical ionization and in sample preparation methods with the development of new matrix compounds for matrix-assisted laser desorption/ionization (MALDI). Also, the combination of ion mobility separation with laser-based ionization methods starts to gain popularity with access to commercial systems. These developments have been driven mainly by the emergence of new application fields such as MS imaging and non-chromatographic analytical approaches for quantification. This review aims to present these new developments in laser-based methods for the analysis of low-molecular weight compounds by MS and several potential applications. PMID:27107904

  1. Sensor Based on Aptamer Folding to Detect Low-Molecular Weight Analytes.

    PubMed

    Osypova, Alina; Thakar, Dhruv; Dejeu, Jérôme; Bonnet, Hugues; Van der Heyden, Angéline; Dubacheva, Galina V; Richter, Ralf P; Defrancq, Eric; Spinelli, Nicolas; Coche-Guérente, Liliane; Labbé, Pierre

    2015-08-01

    Aptamers have emerged as promising biorecognition elements in the development of biosensors. The present work focuses on the application of quartz crystal microbalance with dissipation monitoring (QCM-D) for the enantioselective detection of a low molecular weight target molecule (less than 200 Da) by aptamer-based sensors. While QCM-D is a powerful technique for label-free, real-time characterization and quantification of molecular interactions at interfaces, the detection of small molecules interacting with immobilized receptors still remains a challenge. In the present study, we take advantage of the aptamer conformational changes upon the target binding that induces displacement of water acoustically coupled to the sensing layer. As a consequence, this phenomenon leads to a significant enhancement of the detection signal. The methodology is exemplified with the enantioselective recognition of a low molecular weight model compound, L-tyrosinamide (L-Tym). QCM-D monitoring of L-Tym interaction with the aptamer monolayer leads to an appreciable signal that can be further exploited for analytical purposes or thermodynamics studies. Furthermore, in situ combination of QCM-D with spectroscopic ellipsometry unambiguously demonstrates that the conformational change induces a nanometric decrease of the aptamer monolayer thickness. Since QCM-D is sensitive to the whole mass of the sensing layer including water that is acoustically coupled, a decrease in thickness of the highly hydrated aptamer layer induces a sizable release of water that can be easily detected by QCM-D. PMID:26122480

  2. Glutathione depletion in lung cells by low-molecular-weight aldehydes.

    PubMed

    Meacher, D M; Menzel, D B

    1999-06-01

    Use of oxygenates in gasoline in the United States may increase atmospheric levels of aldehydes. To assist in health assessments of inhalation exposure to aldehydes, we studied glutathione (GSH) depletion by low-molecular-weight n-alkanals and 2-alkenals, ubiquitous air pollutants, in adult rat lung (ARL) cells by laser cytometry. For each homologous series, the effective aldehyde concentration that depleted GSH by 50% (EC50) in ARL cells correlates with published values for the median lethal dose of the chemicals and with Hammett/Taft electronic parameters, sigma* for n-alkanals and sigma(+)p for 2-alkenals. n-Alkanals (EC50, 110-400 mmol/L) were 1000 times less effective in depleting GSH than were 2-alkenals (EC50, 2-180 micromol/L), of which acrolein was the most potent. Ability of the 2-alkenals to deplete GSH follows the second-order rate constant for adduct formation. Ability of n-alkanals to deplete GSH follows chain length. Within a homologous series of low-molecular-weight aldehydes, structure-activity relationships are useful for predicting the toxicity of the aldehydes in vitro and in vivo. PMID:10580549

  3. Analysis of low molecular weight metabolites in tea using mass spectrometry-based analytical methods.

    PubMed

    Fraser, Karl; Harrison, Scott J; Lane, Geoff A; Otter, Don E; Hemar, Yacine; Quek, Siew-Young; Rasmussen, Susanne

    2014-01-01

    Tea is the second most consumed beverage in the world after water and there are numerous reported health benefits as a result of consuming tea, such as reducing the risk of cardiovascular disease and many types of cancer. Thus, there is much interest in the chemical composition of teas, for example; defining components responsible for contributing to reported health benefits; defining quality characteristics such as product flavor; and monitoring for pesticide residues to comply with food safety import/export requirements. Covered in this review are some of the latest developments in mass spectrometry-based analytical techniques for measuring and characterizing low molecular weight components of tea, in particular primary and secondary metabolites. The methodology; more specifically the chromatography and detection mechanisms used in both targeted and non-targeted studies, and their main advantages and disadvantages are discussed. Finally, we comment on the latest techniques that are likely to have significant benefit to analysts in the future, not merely in the area of tea research, but in the analytical chemistry of low molecular weight compounds in general. PMID:24499071

  4. Screening for low molecular weight compounds in fish meal solubles by hydrophilic interaction liquid chromatography coupled to mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple analytical method using hydrophilic interaction liquid chromatography coupled with mass spectrometry was developed to screen for low molecular weight compounds in enzyme treated and untreated Alaskan pollock (Theragra chalcogramma) stickwater (SW) generated from processing fish meal with po...

  5. Synthesis and characterization of sugar based low molecular weight gelators and the preparation of chiral sulfinamides

    NASA Astrophysics Data System (ADS)

    Mangunuru, Hari Prasad Reddy

    Low molecular weight gelators (LMWGs) have received considerable attention in the field of chemistry from last few decades. These compounds form self-assembled fibrous networks like micelles, cylindrical, sheets, fibers, layers and so on. The fibrous network entraps the solvent and forms gel, because of the self-assembly phenomenon and their demonstrated potential uses in a variety of areas, ranging from environmental to medicinal applications. Sugars are good starting materials to synthesize the new class of LMWG's, because these are different from some expensive materials, these are natural products. We have synthesized and characterized the LMGS's based on D-glucose and D-glucosamine. D-glucosamine is the versatile starting material to make different peptoids and triazoles. Several series of compounds were synthesized using compounds 1-3 as starting material and studied the gelation behavior all the compounds. We have studied the self-assembling properties of a new class of tripeptoids, synthesized by one-pot Ugi reaction from simple starting materials. Among the focused library of tripeptoids synthesized, we found that several efficient low molecular weight organogelators were obtained for aqueous DMSO and ethanol mixtures. We have also synthesized and characterized a series of monosaccharide triazole derivatives. These compounds were synthesized from N-acetyl glucosamine and D-glucose via a Cu(I) catalyzed azide/alkyne cycloaddition reaction (CuAAc). The compounds have been screened for their gelation properties and several efficient low molecular weight organo/hydro gelators were obtained, among these compounds, five per-acetyl glucosamine derivatives and one peracetyl glucose derivative were able to form gels in water. These new molecules are expected to be useful in drug delivery and tissue engineering.*. Asymmetric synthesis of chiral amines is a challenging in synthetic organic chemistry. The development of new catalysts for asymmetric organic

  6. Systematic synthesis of low-molecular weight fucoidan derivatives and their effect on cancer cells.

    PubMed

    Kasai, Akihiro; Arafuka, Shinsuke; Koshiba, Nozomi; Takahashi, Daisuke; Toshima, Kazunobu

    2015-11-14

    Low-molecular weight type I and II fucoidan derivatives with different sulfation patterns were designed and systematically synthesized from the corresponding common key intermediate and their anti-proliferative activities and apoptosis-inducing activities against human breast cancer (MCF-7) and human cervical epithelioid carcinoma (HeLa) cells were evaluated. Our results demonstrated that one of the type II fucoidan derivatives, 9, effectively reduced the number of viable MCF-7 and HeLa cells in a dose-dependent manner without causing cytotoxicity toward normal WI-38 cells, and that the anti-proliferative activity of 9 was comparable to that of fucoidan 2 isolated from Fucus vesiculosus. Moreover, it was found that both 2 and 9 exhibited similar apoptosis-inducing activities through activation of caspase-8 and -9 on MCF-7 and HeLa cells, respectively. PMID:26340595

  7. Low Molecular Weight Chitosan–Insulin Polyelectrolyte Complex: Characterization and Stability Studies

    PubMed Central

    Al-Kurdi, Zakieh I.; Chowdhry, Babur Z.; Leharne, Stephen A.; Al Omari, Mahmoud M. H.; Badwan, Adnan A.

    2015-01-01

    The aim of the work reported herein was to investigate the effect of various low molecular weight chitosans (LMWCs) on the stability of insulin using USP HPLC methods. Insulin was found to be stable in a polyelectrolyte complex (PEC) consisting of insulin and LMWC in the presence of a Tris-buffer at pH 6.5. In the presence of LMWC, the stability of insulin increased with decreasing molecular weight of LMWC; 13 kDa LMWC was the most efficient molecular weight for enhancing the physical and chemical stability of insulin. Solubilization of insulin-LMWC polyelectrolyte complex (I-LMWC PEC) in a reverse micelle (RM) system, administered to diabetic rats, results in an oral delivery system for insulin with acceptable bioactivity. PMID:25830681

  8. Desorption electrospray ionisation mass spectrometry and tandem mass spectrometry of low molecular weight synthetic polymers.

    PubMed

    Jackson, Anthony T; Williams, Jonathan P; Scrivens, James H

    2006-01-01

    A range of low molecular weight synthetic polymers has been characterised by means of desorption electrospray ionisation (DESI) combined with both mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Accurate mass experiments were used to aid the structural determination of some of the oligomeric materials. The polymers analysed were poly(ethylene glycol) (PEG), polypropylene glycol (PPG), poly(methyl methacrylate) (PMMA) and poly(alpha-methyl styrene). An application of the technique for characterisation of a polymer used as part of an active ingredient in a pharmaceutical tablet is described. The mass spectra and tandem mass spectra of all of the polymers were obtained in seconds, indicating the sensitivity of the technique. PMID:16912984

  9. Low-molecular-weight thiols in plants: functional and analytical implications.

    PubMed

    Pivato, Micaela; Fabrega-Prats, Marta; Masi, Antonio

    2014-10-15

    Low-molecular-weight (LMW) thiols are a class of highly reactive compounds massively involved in the maintenance of cellular redox homeostasis. They are implicated in plant responses to almost all stress factors, as well as in the regulation of cellular metabolism. The most studied LMW thiols are glutathione and its biosynthetically related compounds (cysteine, γ-glutamylcysteine, cysteinylglycine, and phytochelatins). Other LMW thiols are described in the literature, such as thiocysteine, cysteamine, homocysteine, lipoic acid, and many species-specific volatile thiols. Here, we review the known LMW thiols in plants, briefly describing their physico-chemical properties, their relevance in post-translational protein modification, and recently-developed thiol detection methods. Current research points to a huge thiol biodiversity in plants and many species-specific and organ-specific thiols remain to be identified. Recent advances in technology should help researchers in this very challenging task, helping us to decipher the roles of thiols in plant metabolism. PMID:25057770

  10. Antioxidation activities of low-molecular-weight gelatin hydrolysate isolated from the sea cucumber Stichopus japonicus

    NASA Astrophysics Data System (ADS)

    Wang, Jingfeng; Wang, Yuming; Tang, Qingjuan; Wang, Yi; Chang, Yaoguang; Zhao, Qin; Xue, Changhu

    2010-03-01

    Gelatin extracted from the body wall of the sea cucumber ( Stichopus japonicus) was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate (LMW-GH) of 700-1700 Da was produced using an ultrafiltration membrane bioreactor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μg mL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased intracellular glutathione (GSH), which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.

  11. Low molecular weight fucoidan modulates P-selectin and alleviates diabetic nephropathy.

    PubMed

    Xu, Yingjie; Zhang, Quanbin; Luo, Dali; Wang, Jing; Duan, Delin

    2016-10-01

    Diabetic nephropathy (DN) is a serious microvascular complication that can lead to chronic and end-stage renal failure. It is understood that inflammation is associated with the onset and process of DN. Low molecular weight fucoidan (LMWF) isolated from Saccharina japonica has anti-inflammatory properties. Therefore, this study aimed to explore the mechanism of LMWF in DN model induced by streptozotocin. The biochemical indices levels showed LMWF reduced the DN diagnostic indices to protect renal function. The HE stained sections exhibited LMWF protected normal morphological structures and reduced inflammatory cell infiltration in the kidneys of DN rats. Furthermore, the levels of P-selectin and selectin-dependent inflammatory cytokines resulting from LMWF were obviously decreased at both the transcriptional and protein levels. Thus, our results found that LMWF protected the renal function in DN rats and alleviated inflammation through the modulation of P-selectin and inflammatory cytokines. LMWF may have therapeutic potential against DN. PMID:27234491

  12. Reversible Masking Using Low-Molecular-Weight Neutral Lipids to Achieve Optimal-Targeted Delivery

    PubMed Central

    Templeton, Nancy Smyth; Senzer, Neil

    2012-01-01

    Intravenous injection of therapeutics is required to effectively treat or cure metastatic cancer, certain cardiovascular diseases, and other acquired or inherited diseases. Using this route of delivery allows potential uptake in all disease targets that are accessed by the bloodstream. However, normal tissues and organs also have the potential for uptake of therapeutic agents. Therefore, investigators have used targeted delivery to attempt delivery solely to the target cells; however, use of ligands on the surface of delivery vehicles to target specific cell surface receptors is not sufficient to avoid nonspecific uptake. PEGylation has been used for decades to try to avoid nonspecific uptake but suffers from many problems known as “The PEGylation Dilemma.” We have solved this dilemma by replacing PEGylation with reversible masking using low-molecular-weight neutral lipids in order to achieve optimal-targeted delivery solely to target cells. Our paper will focus on this topic. PMID:22655199

  13. Low Molecular Weight Norbornadiene Derivatives for Molecular Solar-Thermal Energy Storage.

    PubMed

    Quant, Maria; Lennartson, Anders; Dreos, Ambra; Kuisma, Mikael; Erhart, Paul; Börjesson, Karl; Moth-Poulsen, Kasper

    2016-09-01

    Molecular solar-thermal energy storage systems are based on molecular switches that reversibly convert solar energy into chemical energy. Herein, we report the synthesis, characterization, and computational evaluation of a series of low molecular weight (193-260 g mol(-1) ) norbornadiene-quadricyclane systems. The molecules feature cyano acceptor and ethynyl-substituted aromatic donor groups, leading to a good match with solar irradiation, quantitative photo-thermal conversion between the norbornadiene and quadricyclane, as well as high energy storage densities (396-629 kJ kg(-1) ). The spectroscopic properties and energy storage capability have been further evaluated through density functional theory calculations, which indicate that the ethynyl moiety plays a critical role in obtaining the high oscillator strengths seen for these molecules. PMID:27492997

  14. Toxicological Evaluation of Low Molecular Weight Fucoidan in Vitro and in Vivo

    PubMed Central

    Hwang, Pai-An; Yan, Ming-De; Lin, Hong-Ting Victor; Li, Kuan-Lun; Lin, Yen-Chang

    2016-01-01

    For a long time, fucoidan has been well known for its pharmacological activities, and recently low molecular weight fucoidan (LMF) has been used in food supplements and pharmaceutical products. In the present study, LMF was extracted from Laminaria japonica by enzyme hydrolysis. The toxicity of LMF in mouse and rat models was determined by many methods, such as total arsenic content, bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus assay. The present findings showed that LMF at 5000 μg/mL exhibited no mutagenicity. It also produced no formatting disruption of red blood cells in vivo. At 2000 mg/kg BW/day there were no toxicological indications. LMF is expected to be used as a safe food supplement. PMID:27347980

  15. [Antibacterial Activity of Alkylated and Acylated Derivatives of Low-Molecular Weight Chitosan].

    PubMed

    Shagdarova, B Ts; Il'ina, A V; Varlamov, V P

    2016-01-01

    A number of alkylated (quaternized) and acylated derivatives of low-molecular weight chitosan were obtained. The structure and composition of the compounds were confirmed by the results of IR and PMR spectroscopy, as well as conductometric titration. The effect of the acyl substituent and the degree of substitution of N-(2-hydroxy-3-trimethylammonium) with the propyl fragment appended to amino groups of the C2 atom of polymer chains on antibacterial activity against typical representatives of gram-positive and gram-negative microorganisms (Staphylococcus epidermidis and Escherichia coli) was studied. The highest activity was in the case of N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride with the maximal substitution (98%). The minimal inhibitory concentration of the derivative was 0.48 µg/mL and 3.90 µg/mL for S. epidermis and E. coli, respectively. PMID:27266254

  16. Sorption of copper onto low molecular weight chitosan derivative from aqueous solution.

    PubMed

    Boamah, Peter Osei; Huang, Yan; Hua, Mingqing; Onumah, Jacqueline; Sam-Amoah, Livingstone K; Boamah, Paul Osei; Qian, Yaao; Zhang, Qi

    2016-07-01

    In this study, sorption of copper onto low molecular weight chitosan derivative was studied. Experimental parameters such as pH of the solution (A), temperature (B), dose of the sorbent (C), and concentration of solution (D) were considered. The statistical results indicated that the dose of sorbent (C) and Cu (II) concentration (D) influenced removal efficiency at 5% significance level. Also, some interactions such as ABCD, ACD, ABC and AC affected the removal process. The sorbent was characterized with FTIR, SEM and TG/DSC. Freundlich isotherm model was the best isotherm model. The kinetic study results correlated well with the pseudo-second-order model. The thermodynamic studies revealed that the nature of copper sorption was spontaneous and endothermic. Strong affinity of the sorbent for copper (II) was revealed by the Isothermal Titration Calorimetry (ITC) technique. PMID:27039244

  17. Preferential synthesis of low-molecular-weight RNA in uv-irradiated plasma of Physarum polycephalum

    SciTech Connect

    Kumari, P.A.V.; Nair, V.R.

    1981-10-01

    Mitotically synchronous surface plasmodia of Physarum polycephalum were irradiated during the G2 phase with a Philips 15-W germicidal lamp. At different intervals after irradiation, the plasmodia were pulse-labeled with (/sup 3/H)uridine, and RNA was extracted and analyzed on linear sucrose gradients. The radioactivity profiles of the RNA showed that irradiated plasmodia synthesize preferentially low-molecular-weight RNA types, including 4 SRNA, during the delay period prior to the first postirradiation mitosis and during the following short mitotic cycle. Double-labeling experiments, employing (/sup 14/C)uridine-prelabeled plasmodia which were pulse-labeled with (/sup 3/H)uridine after irradiation, confirmed this finding. It is also seen that there is an overall reduction in the rate of synthesis of rRNA in the irradiated plasmodia.

  18. Toxicological Evaluation of Low Molecular Weight Fucoidan in Vitro and in Vivo.

    PubMed

    Hwang, Pai-An; Yan, Ming-De; Lin, Hong-Ting Victor; Li, Kuan-Lun; Lin, Yen-Chang

    2016-01-01

    For a long time, fucoidan has been well known for its pharmacological activities, and recently low molecular weight fucoidan (LMF) has been used in food supplements and pharmaceutical products. In the present study, LMF was extracted from Laminaria japonica by enzyme hydrolysis. The toxicity of LMF in mouse and rat models was determined by many methods, such as total arsenic content, bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus assay. The present findings showed that LMF at 5000 μg/mL exhibited no mutagenicity. It also produced no formatting disruption of red blood cells in vivo. At 2000 mg/kg BW/day there were no toxicological indications. LMF is expected to be used as a safe food supplement. PMID:27347980

  19. In vivo endothelial siRNA delivery using polymeric nanoparticles with low molecular weight

    NASA Astrophysics Data System (ADS)

    Dahlman, James E.; Barnes, Carmen; Khan, Omar F.; Thiriot, Aude; Jhunjunwala, Siddharth; Shaw, Taylor E.; Xing, Yiping; Sager, Hendrik B.; Sahay, Gaurav; Speciner, Lauren; Bader, Andrew; Bogorad, Roman L.; Yin, Hao; Racie, Tim; Dong, Yizhou; Jiang, Shan; Seedorf, Danielle; Dave, Apeksha; Singh Sandhu, Kamaljeet; Webber, Matthew J.; Novobrantseva, Tatiana; Ruda, Vera M.; Lytton-Jean, Abigail K. R.; Levins, Christopher G.; Kalish, Brian; Mudge, Dayna K.; Perez, Mario; Abezgauz, Ludmila; Dutta, Partha; Smith, Lynelle; Charisse, Klaus; Kieran, Mark W.; Fitzgerald, Kevin; Nahrendorf, Matthias; Danino, Dganit; Tuder, Rubin M.; von Andrian, Ulrich H.; Akinc, Akin; Panigrahy, Dipak; Schroeder, Avi; Koteliansky, Victor; Langer, Robert; Anderson, Daniel G.

    2014-08-01

    Dysfunctional endothelium contributes to more diseases than any other tissue in the body. Small interfering RNAs (siRNAs) can help in the study and treatment of endothelial cells in vivo by durably silencing multiple genes simultaneously, but efficient siRNA delivery has so far remained challenging. Here, we show that polymeric nanoparticles made of low-molecular-weight polyamines and lipids can deliver siRNA to endothelial cells with high efficiency, thereby facilitating the simultaneous silencing of multiple endothelial genes in vivo. Unlike lipid or lipid-like nanoparticles, this formulation does not significantly reduce gene expression in hepatocytes or immune cells even at the dosage necessary for endothelial gene silencing. These nanoparticles mediate the most durable non-liver silencing reported so far and facilitate the delivery of siRNAs that modify endothelial function in mouse models of vascular permeability, emphysema, primary tumour growth and metastasis.

  20. A low molecular weight proteome comparison of fertile and male sterile 8 anthers of Zea mays

    PubMed Central

    Wang, Dongxue; Adams, Christopher M.; Fernandes, John F.; Egger, Rachel L.; Walbot, Virginia

    2014-01-01

    Summary During maize anther development, somatic locular cells differentiate to support meiosis in the pollen mother cells. Meiosis is an important event during anther growth and is essential for plant fertility as pollen contains the haploid sperm. A subset of maize male sterile mutants exhibit meiotic failure, including ms8 (male sterile 8) in which meiocytes arrest as dyads and the locular somatic cells exhibit multiple defects. Systematic proteomic profiles were analysed in biological triplicates plus technical triplicates comparing ms8 anthers with fertile sibling samples at both the premeiotic and meiotic stages; proteins from 3.5 to 20 kDa were fractionated by 1-D PAGE, cleaved with Lys-C and then sequenced using a LTQ Orbitrap Velos MS paradigm. Three hundred and 59proteins were identified with two or more assigned peptides in which each of those peptides were counted at least two or more times (0.4% peptide false discovery rate (FDR) and 0.2% protein FDR); 2761 proteins were identified with one or more assigned peptides (0.4% peptide FDR and 7.6% protein FDR). Stage-specific protein expression provides candidate stage markers for early anther development, and proteins specifically expressed in fertile compared to sterile anthers provide important clues about the regulation of meiosis. 49% of the proteins detected by this study are new to an independent whole anther proteome, and many small proteins missed by automated maize genome annotation were validated; these outcomes indicate the value of focusing on low molecular weight proteins. The roles of distinctive expressed proteins and methods for mass spectrometry of low molecular weight proteins are discussed. PMID:22748129

  1. Capture, enrichment, and mass spectrometric detection of low-molecular-weight biomarkers with nanoporous silicon microparticles.

    PubMed

    Tan, Jie; Zhao, Wei-Jie; Yu, Jie-Kai; Ma, Sai; Sailor, Michael J; Wu, Jian-Min

    2012-11-01

    Mining the disease information contained in the low-molecular-weight range of a proteomic profile is becoming of increasing interest in cancer research. This work evaluates the ability of nanoporous silicon microparticles (NPSMPs) to capture, enrich, protect, and detect low-molecular-weight peptides (LMWPs) sieved from a pool of highly abundant plasma proteins. The average pore size and porosity of NPSMPs are controlled by the electrochemical preparation conditions, and the critical parameters for admission or exclusion of protein with a definite molecular weight are determined by reflectometric-interference Fourier transform spectroscopy (RIFTS). Sodium dodecyl sulfate polyacrylamide-gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis of the proteins captured by the NPSMPs show that the chemical nature of the NPSMPs surface and the solution pH also play vital roles in determining the affinity of NPSMPs for target analytes. It is found that carboxyl-terminated porous microparticles with a porosity of 26% (pore diameter around 9.0 nm) specifically fractionate, enrich and protect LMWPs sieved from either simulated samples or human serum samples. Moreover, NPSMPs containing captured peptides can be directly spotted onto a MALDI plate. When placed in a conventional MALDI matrix, laser irradiation of the particles results in the release of the target peptides confined in the nanopores, which are then ionized and detected in the MALDI experiment. As a proof-of-principle test case, mass spectra of NPSMPs prepared using serum from colorectal cancer patients and from control patients can be clearly distinguished by statistical analysis. The work demonstrates the utility of the method for discovery of biomarkers in the untapped LMWP fraction of human serum, which can be of significant value in the early diagnosis and management of diseases. PMID:23184826

  2. High and low molecular weight hyaluronic acid differentially influence macrophage activation

    PubMed Central

    Rayahin, Jamie E.; Buhrman, Jason S.; Zhang, Yu; Koh, Timothy J.; Gemeinhart, Richard A.

    2015-01-01

    Macrophages exhibit phenotypic diversity permitting wide-ranging roles in maintaining physiologic homeostasis. Hyaluronic acid, a major glycosaminoglycan of the extracellular matrix, has been shown to have differential signaling based on its molecular weight. With this in mind, the main objective of this study was to elucidate the role of hyaluronic acid molecular weight on macrophage activation and reprogramming. Changes in macrophage activation were assessed by activation state selective marker measurement, specifically quantitative real time polymerase chain reaction, and cytokine enzyme-linked immunoassays, after macrophage treatment with differing molecular weights of hyaluronic acid under four conditions: the resting state, concurrent with classical activation, and following inflammation involving either classically or alternatively activated macrophages. Regardless of initial polarization state, low molecular weight hyaluronic acid induced a classically activated-like state, confirmed by up-regulation of pro-inflammatory genes, including nos2, tnf, il12b, and cd80, and enhanced secretion of nitric oxide and TNF-α. High molecular weight hyaluronic acid promoted an alternatively activated-like state, confirmed by up regulation of pro-resolving gene transcription, including arg1, il10, and mrc1, and enhanced arginase activity. Overall, our observations suggest that macrophages undergo phenotypic changes dependent on molecular weight of hyaluronan that correspond to either (1) pro-inflammatory response for low molecular weight HA or (2) pro-resolving response for high molecular weight HA. These observations bring significant further understanding of the influence of extracellular matrix polymers, hyaluronic acid in particular, on regulating the inflammatory response of macrophages. This knowledge can be used to guide the design of HA-containing biomaterials to better utilize the natural response to HAs. PMID:26280020

  3. Low-Molecular-Weight Sulfonates, a Major Substrate for Sulfate Reducers in Marine Microbial Mats†

    PubMed Central

    Visscher, Pieter T.; Gritzer, Rachel F.; Leadbetter, Edward R.

    1999-01-01

    Several low-molecular-weight sulfonates were added to microbial mat slurries to investigate their effects on sulfate reduction. Instantaneous production of sulfide occurred after taurine and cysteate were added to all of the microbial mats tested. The rates of production in the presence of taurine and cysteate were 35 and 24 μM HS− h−1 in a stromatolite mat, 38 and 36 μM HS− h−1 in a salt pond mat, and 27 and 18 μM HS− h−1 in a salt marsh mat, respectively. The traditionally used substrates lactate and acetate stimulated the rate of sulfide production 3 to 10 times more than taurine and cysteate stimulated the rate of sulfide production in all mats, but when ethanol, glycolate, and glutamate were added to stromatolite mat slurries, the resulting increases were similar to the increases observed with taurine and cysteate. Isethionate, sulfosuccinate, and sulfobenzoate were tested only with the stromatolite mat slurry, and these compounds had much smaller effects on sulfide production. Addition of molybdate resulted in a greater inhibitory effect on acetate and lactate utilization than on sulfonate use, suggesting that different metabolic pathways were involved. In all of the mats tested taurine and cysteate were present in the pore water at nanomolar to micromolar concentrations. An enrichment culture from the stromatolite mat was obtained on cysteate in a medium lacking sulfate and incubated anaerobically. The rate of cysteate consumption by this enrichment culture was 1.6 pmol cell−1 h−1. Compared to the results of slurry studies, this rate suggests that organisms with properties similar to the properties of this enrichment culture are a major constituent of the sulfidogenic population. In addition, taurine was consumed at some of highest dilutions obtained from most-probable-number enrichment cultures obtained from stromatolite samples. Based on our comparison of the sulfide production rates found in various mats, low-molecular-weight sulfonates

  4. Early heparin therapy in patients with spontaneous intracerebral haemorrhage.

    PubMed Central

    Boeer, A; Voth, E; Henze, T; Prange, H W

    1991-01-01

    In 68 patients with spontaneous intracerebral haemorrhage the effect of heparin treatment beginning on the second, fourth or tenth day was investigated. Early (day 2) low-dose heparin medication significantly lowered the incidence of pulmonary embolism. An increase in the number of patients with rebleeding was not observed. The results indicate that the early use of heparin in these patients is safe and can be recommended for the prevention of thromboembolic complications. PMID:1865215

  5. Studies on the low molecular weight RNA associated with 28S ribosomal RNA from Crotalus durissus terrificus liver.

    PubMed Central

    Giorgini, J F; De Lucca, F L

    1976-01-01

    A low molecular weight RNA was released from the purified rattlesnake 28 S RNA by brief heat treatment as well as by treatment with 80% dimethylsulfoxide or formamide. The sedimentation coeficient of this low molecular weight RNA was found to be 5.5 S, corresponding to a nucleotide number of 140 and a molecular weight of 46 000. It was also observed that 5.5S RNA is present in equimolar ratio to 5 S rRNA. Heat treatment of the purified 60 S ribosomal subunit also released the 5.5 S RNA. The possibility that this low molecular weight RNA is located on the surface of the large ribosomal subunit is discussed. PMID:1250695

  6. Low molecular weight compounds with transition metals as free radical scavengers and novel therapeutic agents.

    PubMed

    Bencini, Andrea; Failli, Paola; Valtancoli, Barbara; Bani, Daniele

    2010-07-01

    Molecules able to modulate the levels of endogenous free radicals, such as reactive oxygen species (ROS) and nitric oxide (NO), are of pivotal interest for pharmacological and pharmaceutical sciences because of their potential therapeutic relevance. In fact, ROS and NO, which are normal products of cell metabolism, may play a dual beneficial/deleterious role, depending on local concentration and mode of generation. As such, they have been identified as key pathogenic factors for many inflammatory, vascular dysfunctional and degenerative disorders, including atherosclerosis, hypertension, cardiovascular and neurodegenerative diseases, cancer, diabetes mellitus, and ageing. Therefore, the identification and characterization of novel antioxidant/free radical scavenger molecules may expand the current therapeutic implements for the treatment and prevention of the above diseases. In this perspective, low molecular weight complexes of transition metals with organic scaffolds are viewed and investigated as promising pharmaceutical agents. These complexes take advantage of the known principles of inorganic chemistry, i.e. the ability of transition metals, Fe(II), Co(II), Mn(II) and Ru(II), to bind to and react with NO and/or ROS, to counterbalance excessive endogenous free radical generation in biological systems. Among NO scavengers, representative examples are iron complexes with dithiocarbamates or ruthenium compounds with polyamine-polycarboxylate scaffolds; on the other hand, manganese-based molecules appear effective as ROS scavengers. Of note, Mn(II)-containing molecules, currently under study as ROS scavengers, have major functional similarities to Mn-superoxide dismutase (SOD), a Mn-containing enzyme acting as potent endogenous anti-oxidant. In this article, we briefly summarize the state-of-the-art concerning the chemical and biological properties of transition metal ion complexes with low molecular weight synthetic ligands as ROS/NO scavengers provided with

  7. Surface engineering on mesoporous silica chips for enriching low molecular weight phosphorylated proteins

    NASA Astrophysics Data System (ADS)

    Hu, Ye; Peng, Yang; Lin, Kevin; Shen, Haifa; Brousseau, Louis C., III; Sakamoto, Jason; Sun, Tong; Ferrari, Mauro

    2011-02-01

    Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous silica thin films with precisely engineered pore sizes that sterically select for molecular size combined with chemically selective surface modifications (i.e. Ga3+, Ti4+ and Zr4+) that target phosphoroproteins. These materials provide high reproducibility (CV = 18%) and increase the stability of the captured proteins by excluding degrading enzymes, such as trypsin. The chemical and physical properties of the composite mesoporous thin films were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and ellipsometry. Using mass spectroscopy and biostatistics analysis, the enrichment efficiency of different metal ions immobilized on mesoporous silica chips was investigated. The novel technology reported provides a platform capable of efficiently profiling the serum proteome for biomarker discovery, forensic sampling, and routine diagnostic applications.Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous

  8. Ancient low-molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw.

    PubMed

    Drake, Travis W; Wickland, Kimberly P; Spencer, Robert G M; McKnight, Diane M; Striegl, Robert G

    2015-11-10

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high-temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low-molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters. PMID:26504243

  9. Crystal structure and putative substrate identification for the Entamoeba histolytica low molecular weight tyrosine phosphatase.

    PubMed

    Linford, Alicia S; Jiang, Nona M; Edwards, Thomas E; Sherman, Nicholas E; Van Voorhis, Wesley C; Stewart, Lance J; Myler, Peter J; Staker, Bart L; Petri, William A

    2014-01-01

    Entamoeba histolytica is a eukaryotic intestinal parasite of humans, and is endemic in developing countries. We have characterized the E. histolytica putative low molecular weight protein tyrosine phosphatase (LMW-PTP). The structure for this amebic tyrosine phosphatase was solved, showing the ligand-induced conformational changes necessary for binding of substrate. In amebae, it was expressed at low but detectable levels as detected by immunoprecipitation followed by immunoblotting. A mutant LMW-PTP protein in which the catalytic cysteine in the active site was replaced with a serine lacked phosphatase activity, and was used to identify a number of trapped putative substrate proteins via mass spectrometry analysis. Seven of these putative substrate protein genes were cloned with an epitope tag and overexpressed in amebae. Five of these seven putative substrate proteins were demonstrated to interact specifically with the mutant LMW-PTP. This is the first biochemical study of a small tyrosine phosphatase in Entamoeba, and sets the stage for understanding its role in amebic biology and pathogenesis. PMID:24548880

  10. Crystal structure and putative substrate identification for the Entamoeba histolytica low molecular weight tyrosine phosphatase

    PubMed Central

    Linford, Alicia S.; Jiang, Nona M.; Edwards, Thomas E.; Sherman, Nicholas E.; Van Voorhis, Wesley C.; Stewart, Lance J.; Myler, Peter J.; Staker, Bart L.; Petri, William A.

    2014-01-01

    Entamoeba histolytica is a eukaryotic intestinal parasite of humans, and is endemic in developing countries. We have characterized the E. histolytica putative low molecular weight protein tyrosine phosphatase (LMW-PTP). The structure for this amebic tyrosine phosphatase was solved, showing the ligand-induced conformational changes necessary for binding of substrate. In amebae, it was expressed at low but detectable levels as detected by immunoprecipitation followed by immunoblotting. A mutant LMW-PTP protein in which the catalytic cysteine in the active site was replaced with a serine lacked phosphatase activity, and was used to identify a number of trapped putative substrate proteins via mass spectrometry analysis. Seven of these putative substrate protein genes were cloned with an epitope tag and overexpressed in amebae. Five of these seven putative substrate proteins were demonstrated to interact specifically with the mutant LMW-PTP. This is the first biochemical study of a small tyrosine phosphatase in Entamoeba, and sets the stage for understanding its role in amebic biology and pathogenesis. PMID:24548880

  11. Low molecular weight protein tyrosine phosphatase: Multifaceted functions of an evolutionarily conserved enzyme.

    PubMed

    Caselli, Anna; Paoli, Paolo; Santi, Alice; Mugnaioni, Camilla; Toti, Alessandra; Camici, Guido; Cirri, Paolo

    2016-10-01

    Originally identified as a low molecular weight acid phosphatase, LMW-PTP is actually a protein tyrosine phosphatase that acts on many phosphotyrosine-containing cellular proteins that are primarily involved in signal transduction. Differences in sequence, structure, and substrate recognition as well as in subcellular localization in different organisms enable LMW-PTP to exert many different functions. In fact, during evolution, the LMW-PTP structure adapted to perform different catalytic actions depending on the organism type. In bacteria, this enzyme is involved in the biosynthesis of group 1 and 4 capsules, but it is also a virulence factor in pathogenic strains. In yeast, LMW-PTPs dephosphorylate immunophilin Fpr3, a peptidyl-prolyl-cis-trans isomerase member of the protein chaperone family. In humans, LMW-PTP is encoded by the ACP1 gene, which is composed of three different alleles, each encoding two active enzymes produced by alternative RNA splicing. In animals, LMW-PTP dephosphorylates a number of growth factor receptors and modulates their signalling processes. The involvement of LMW-PTP in cancer progression and in insulin receptor regulation as well as its actions as a virulence factor in a number of pathogenic bacterial strains may promote the search for potent, selective and bioavailable LMW-PTP inhibitors. PMID:27421795

  12. Amphiphilic Interpenetrating Networks for the Delivery of Hydrophobic, Low Molecular Weight Therapeutic Agents

    PubMed Central

    Schoener, Cody A.; Hutson, Heather N.; Fletcher, Grace K.; Peppas, Nicholas A.

    2011-01-01

    To investigate the delivery of hydrophobic therapeutic agents, a novel class of interpenetrating networks (IPNs) were synthesized and composed of two networks: methacrylic acid grafted with poly(ethylene glycol) tethers, P(MAA-g-EG), and poly(n-butyl acrylate) (PBA). The hydrophilic P(MAA-g-EG) networks are pH-responsive hydrogels capable of triggered release of an encapsulated therapeutic agent, such as a low molecular weight drug or a protein, when it passes from the stomach (low pH) to upper small intestine (neutral pH). PBA is a hydrophobic homopolymer that can affect the IPN swelling behavior, the therapeutic agent loading efficiencies in IPNs, and solute release profiles from IPNs. In dynamic swelling conditions, IPNs had greater swelling ratios than P(MAA-g-EG), but in equilibrium swelling conditions the IPN swelling ratio decreased with increasing PBA content. Loading efficiencies of the model therapeutic agent fluorescein ranged from 21 – 44%. Release studies from neat P(MAA-g-EG) and the ensuing IPNs indicated that the transition from low pH (2.0) to neutral pH (7.0) triggered fluorescein release. Maximum fluorescein release depended on the structure and hydrophilicity of the carriers used in these studies. PMID:22247592

  13. Antioxidative low molecular weight compounds in marinated herring (Clupea harengus) salt brine.

    PubMed

    Gringer, Nina; Safafar, Hamed; du Mesnildot, Axelle; Nielsen, Henrik H; Rogowska-Wrzesinska, Adelina; Undeland, Ingrid; Baron, Caroline P

    2016-03-01

    This study aimed at unravelling the antioxidative capacity of low molecular weight compounds (LMWC) (peptides, amino acids and phenolic acids) present in salt brines from the marinated herring production. Brines were fractionated into <10kDa fractions using dialysis and further into 94 fractions using size exclusion chromatography. All samples were analysed for protein, total phenolic content (TPC) and antioxidant activities. Protein-enriched samples were pooled (P1, P2 and P3) and analysed for phenolic acids, total amino acids and peptide/protein sequence using advanced mass spectrometry. All salt brines contain LMWC holding ABTS-radical scavenging activity, reducing power and iron chelating activity. Generally, a strong correlation between TPC and ABTS-radical scavenging was found. In contrast, reducing power and iron chelating activity seemed to be caused by peptides. Protein/peptide sequencing revealed 1kDa peptides with the presence of HDF-motif which could be responsible for some of the antioxidant capacity observed in marinated herring salt brine. PMID:26471668

  14. In situ injection of phenylboronic acid based low molecular weight gels for efficient chemotherapy.

    PubMed

    Gao, Wenxia; Liang, Yan; Peng, Xinyu; Hu, Yalong; Zhang, Longgui; Wu, Huayue; He, Bin

    2016-10-01

    Injectable low molecular weight gels (LMWGs) based on the derivatives of phenylboronic acid were prepared and used as substrates for efficient in situ chemotherapy. The gelators as well as LMWGs were characterized by (1)H NMR, UV-vis, FTIR, MS and SEM. Anticancer drug doxorubicin hydrochloride (DOX) was encapsulated in the gels. The rheological properties and rapid recovery capability of both blank and drug-loaded gels were tested. The LMWGs were non-toxic to both 3T3 fibroblasts and 4T1 breast cancer cells. The gels were formed rapidly after injected in vivo. The in vivo anticancer activities of DOX-loaded LMWGs were investigated in breast cancer bearing mice. The intratumoral injection of DOX loaded LMWGs with dose of 30 mg/kg revealed that the gels could coat around the tumor tissues to release DOX sustainingly and maintain effective DOX concentration for chemotherapy. The systemic toxicity of DOX was reduced significantly with the in situ administration of LMWGs formulations. The injectable LMWGs exhibited excellent therapeutic efficacy and low side effects in local chemotherapy. PMID:27497056

  15. Novel Ion-Exchange Coagulants Remove More Low Molecular Weight Organics than Traditional Coagulants.

    PubMed

    Zhao, Huazhang; Wang, Lei; Hanigan, David; Westerhoff, Paul; Ni, Jinren

    2016-04-01

    Low molecular weight (MW) charged organic matter is poorly removed by conventional coagulants but contributes to disinfection byproduct formation during chlorination of drinking waters. We hypothesized that CIEX, a new Al-based hybrid coagulant with ion-exchange functional groups, would be new mechanistic approach to remove low MW organic matter during coagulation and would perform better than polyaluminum chloride (PACl) or metal-salt based coagulants. We measured coagulation performance using dissolved organic carbon (DOC) in a high hardness surface water. CIEX achieved excellent turbidity removal and removed 20% to 46% more DOC than FeCl3, Al2(SO4)3, or PACl, depending on dose. The improved DOC removal was attributable to better removal of low MW organic matter (<2 kDa). We further studied removal mechanisms in a model water containing a low MW organic acid (salicylic acid (SA)). CIEX achieved high removal of organic acids (>90% of SA) independent of pH, whereas removal by metal salts was lower (<15%) and was strongly pH dependent. CIEX ion-exchange capability is facilitated by its covalently bound quaternary ammonium group, which conventional coagulants lack. Plus, unlike other cationic polymers that react with chloramines to form N-nitrosodimethylamine (NDMA), CIEX has a low molar yield (9.3 × 10(-7) mol NDMA per mol CIEX-N). PMID:26974542

  16. Three low molecular weight cysteine proteinase inhibitors of human seminal fluid: purification and enzyme kinetic properties.

    PubMed

    Yadav, Vikash Kumar; Chhikara, Nirmal; Gill, Kamaldeep; Dey, Sharmistha; Singh, Sarman; Yadav, Savita

    2013-08-01

    The cystatins form a superfamily of structurally related proteins with highly conserved structural folds. They are all potent, reversible, competitive inhibitors of cysteine proteinases (CPs). Proteins from this group present differences in proteinase inhibition despite their high level of structural similarities. In this study, three cysteine proteinase inhibitors (CPIs) of low molecular weight were isolated from human seminal fluid (HSF) by affinity chromatography on carboxymethyl (CM)-papain-Sepharose column, purified using various chromatographic procedures and checked for purity on sodium-dodecyl PAGE (SDS-PAGE). Matrix-assisted laser desorption-ionization-time-of flight-mass spectrometry (MALDI-TOF-MS) identified these proteins as cystatin 9, cystatin SN, and SAP-1 (an N-terminal truncated form of cystatin S). All three CPIs suppressed the activity of papain potentially and showed remarkable heat stability. Interestingly SAP-1 also inhibits the activity of trypsin, chymotrypsin, pepsin, and PSA (prostate specific antigen) and acts as a cross-class protease inhibitor in in vitro studies. Using Surface Plasmon Resonance, we have also observed that SAP-1 shows a significant binding with all these proteases. These studies suggest that SAP-1 is a cross-class inhibitor that may regulate activity of various classes of proteases within the reproductive systems. To our knowledge, this is the first report about purification of CPIs from HSF; the identification of such proteins could provide better insights into the physiological processes and offer intimation for further research. PMID:23619703

  17. A novel role of low molecular weight hyaluronan in breast cancer metastasis.

    PubMed

    Wu, Man; Cao, Manlin; He, Yiqing; Liu, Yiwen; Yang, Cuixia; Du, Yan; Wang, Wenjuan; Gao, Feng

    2015-04-01

    Low molecular weight hyaluronan (LMW-HA), a degradation fragment of the extracellular matrix component hyaluronan (HA), has been proven to play a crucial role in cancer progression. However, no systematic clinical study of breast cancer has been performed to correlate LMW-HA levels with metastasis. In the present study, we analyzed 176 serum specimens and found for the first time that the serum LMW-HA (but not total HA) level significantly correlated with lymph node metastasis, suggesting that serum LMW-HA represents a better prognostic indicator of breast cancer progression than HA. Similarly, we found that breast cancer cell lines displaying higher invasive potential had a higher LMW-HA concentration than less-invasive cell lines. This higher LMW-HA level was accompanied by the overexpression of hyaluronan synthase (HAS2) and hyaluronidase (both HYAL1 and HYAL2). Of great importance, decreasing LMW-HA production significantly inhibited breast cancer cell migration and invasion. Overall, our results suggest that during cancer progression, cancer cells may actively remodel their microenvironment via an autocrine/paracrine-like process, resulting in elevated LMW-HA levels, which in turn may facilitate cancer progression by promoting the migration and invasion of cancer cells. Therefore, cancer-associated LMW-HA may be a more promising molecular biomarker than total HA for detecting metastasis and may have further applications in breast cancer treatment. PMID:25550464

  18. A low molecular weight artificial RNA of unique size with multiple probe target regions

    NASA Technical Reports Server (NTRS)

    Pitulle, C.; Dsouza, L.; Fox, G. E.

    1997-01-01

    Artificial RNAs (aRNAs) containing novel sequence segments embedded in a deletion mutant of Vibrio proteolyticus 5S rRNA have previously been shown to be expressed from a plasmid borne growth rate regulated promoter in E. coli. These aRNAs accumulate to high levels and their detection is a promising tool for studies in molecular microbial ecology and in environmental monitoring. Herein a new construct is described which illustrates the versatility of detection that is possible with aRNAs. This 3xPen aRNA construct carries a 72 nucleotide insert with three copies of a unique 17 base probe target sequence. This aRNA is 160 nucleotides in length and again accumulates to high levels in the E. coli cytoplasm without incorporating into ribosomes. The 3xPen aRNA illustrates two improvements in detection. First, by appropriate selection of insert size, we obtained an aRNA which provides a unique and hence, easily quantifiable peak, on a high resolution gel profile of low molecular weight RNAs. Second, the existence of multiple probe targets results in a nearly commensurate increase in signal when detection is by hybridization. These aRNAs are naturally amplified and carry sequence segments that are not found in known rRNA sequences. It thus may be possible to detect them directly. An experimental step involving RT-PCR or PCR amplification of the gene could therefore be avoided.

  19. Electroejaculation increases low molecular weight proteins in seminal plasma modifying sperm quality in Corriedale rams.

    PubMed

    Ledesma, A; Manes, J; Cesari, A; Alberio, R; Hozbor, F

    2014-04-01

    This study was conducted to evaluate the effect of seminal collection method (artificial vagina or electroejaculation) on the protein composition of seminal plasma and sperm quality parameters in Corriedale rams. To address this question, we assessed the effect of seminal collection method on motility, plasma membrane integrity and functionality, mitochondrial functionality and the decondensation state of nuclear chromatin in sperm cells. Volume, pH, osmolarity, protein concentration, total protein content and protein profile using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2-D polyacrylamide electrophoresis of seminal plasma collected with artificial vagina and electroejaculation were also analysed. The main findings from this study were that ejaculates obtained with electroejaculation had (i) a higher number of spermatozoa with intact plasma membrane and functional mitochondria and (ii) a higher proportion of seminal plasma, total protein content and relative abundance of low molecular weight proteins than ejaculates obtained with artificial vagina. Five of these proteins were identified by mass spectrometry: binder of sperm 5 precursor; RSVP14; RSVP22; epididymal secretory protein E1 and clusterin. One protein spot with molecular weight of approximately 31 kDa and isoelectric point of 4.8 was only found in the seminal plasma from electroejaculation. PMID:24494601

  20. Length variations of i-type low-molecular-weight glutenin subunit genes in diploid wheats.

    PubMed

    Long, H; Huang, Z; Wei, Y-M; Yan, Z-H; Ma, Z-C; Zheng, Y-L

    2008-04-01

    Allelic variation of the low-molecular-weight glutenin subunit (LMW-GS) is associated with the significant differences of dough quality in bread and durum wheat, and has been widely evaluated at protein level in wheat and its relatives. In this study, a PCR primer set, targeting the high variable repetitive domains, was employed to assay the length variation of i-type LMW-GS genes in the A-genomes of diploid wheats, the diploid progenitors of tetraploid and hexaploid wheat. A total of 71 accessions of diploid wheats, belonging to two wild and one cultivated species, were investigated. The higher variations of repetitive length in i-type LMW-GS genes were found in diploid wheats with Nei's genetic variation index (H) of 0.834. The two wild species, T. boeoticum and T. urartu, were found to possess the similar degree of variability, with the Nei's genetic variation index of 0.806 and 0.783, respectively. Less variations were detected in T. monococcum (H = 0.680), a cultivated species domesticated from T. boeoticum. The sufficient variations found in this study could be used as valuable sources for the enrichment of the genetic variations and the alteration of flour-processing properties of the cultivated wheat. To our knowledge, it was the first time that an analysis of length variation targeting a particular group of genes of LMW-GS complex multigene families was conducted. PMID:18666554

  1. Physicochemical characterization of a low-molecular-weight fructooligosaccharide from Chinese Cangshan garlic (Allium sativum L.).

    PubMed

    Zhang, Min; Du, Weina; Bi, Hua

    2012-09-19

    A novel low-molecular-weight fructooligosaccharide (LMWF) from garlic ( Allium sativum ) was isolated and identified. The structure and physicochemical properties of the LMWF were determined by chemical and spectroscopic methods, size-exclusion chromatography, atomic force microscopy (AFM), dynamic rheometry, and differential scanning calorimetry (DSC). The results showed that the LMWF was a neo-ketose with a molecular weight of 1770 Da. The LMWF had a (2,1)-linked β-D-Fruf backbone with (2,6)-linked β-D-Fruf side chains, and it was mainly composed of fructose. The branch degree was 18.1%, and the intrinsic viscosity was 3.06 mL/g. The spherical particles of the LMWF were observed by AFM, and their size was relatively uniform. With an increase in the water content, the peak temperature (T(p)), onset temperature (T(o)), and endset temperature (T(c)) increased, while the gelatinization enthalpy (ΔH(gel)) decreased. The LMWF was more stable at a water content of 10%. PMID:22931231

  2. Low-Molecular-Weight Organo- and Hydrogelators Based on Cyclo(l-Lys-l-Glu).

    PubMed

    Geng, Huimin; Ye, Lin; Zhang, Ai-Ying; Li, Jingbo; Feng, Zeng-Guo

    2016-05-10

    Four cyclo(l-Lys-l-Glu) derivatives (3-6) were synthesized from the coupling reaction of protecting l-lysine with l-glutamic acid followed by the cyclization, deprotection, and protection reactions. They can efficiently gelate a wide variety of organic solvents or water. Interestingly, a spontaneous chemical reaction proceeded in the organogel obtained from 3 in acetone exhibiting not only visual color alteration but also increasing mechanical strength with the progress of time due to the formation of Schiff base. Moreover, 6 bearing a carboxylic acid and Fmoc group displayed a robust hydrogelation capability in PBS solution. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed the characteristic gelation morphologies of 3D fibrous network structures in the resulting organo- and hydrogels. FT-IR and fluorescence analyses indicated that the hydrogen bonding and π-π stacking play as major driving forces for the self-assembly of these cyclic dipeptides as low-molecular-weight gelators. X-ray diffraction (XRD) measurements and computer modeling provided information on the molecular packing model in the hydrogelation state of 6. A spontaneous chemical reaction proceeded in the organogel obtained from 3 in acetone exhibiting visual color alteration and increasing mechanical strength. 6 bearing an optimized balance of hydrophilicity to lipophilicity gave rise to a hydrogel in PBS with MGC at 1 mg/mL. PMID:27101967

  3. Mercury Photolytic Transformation Affected by Low-Molecular-Weight Natural Organics in Water

    SciTech Connect

    He, Feng; Zheng, Wang; Gu, Baohua; Liang, Liyuan

    2012-01-01

    Mechanisms by which dissolved organic matter (DOM) mediates the photochemical reduction of Hg(II) in aquatic ecosystems are not fully understood, owing to the heterogeneous nature and complex structural properties of DOM. In this work, naturally occurring aromatic compounds including salicylic, 4-hydrobenzoic, anthranilic, 4-aminobenzoic, and phthalic acid were systematically studied as surrogates for DOM in order to gain an improved mechanistic understanding of these compounds in the photoreduction of Hg(II) in water. We show that the photoreduction rates of Hg(II) are influenced not only by the substituent functional groups such as OH, NH2 and COOH on the benzene ring, but also the positioning of these functional groups on the ring structure. The Hg(II) photoreduction rate decreases in the order anthranilic acid > salicylic acid > phthalic acid according to the presence of the NH2, OH, COOH functional groups on benzoic acid. The substitution position of the functional groups affects reduction rates in the order anthranilic acid > 4-aminobenzoic acid and salicylic acid > 4-hydroxybenzoic acid. Reduction rates correlate strongly with ultraviolet (UV) absorption of these compounds and their concentrations, suggesting that the formation of organic free radicals during photolysis of these compounds is responsible for Hg(II) photoreduction. These results provide insight into the role of low-molecular-weight organic compounds and possibly DOM in Hg photoredox transformation and may thus have important implications for understanding Hg geochemical cycling in the environment.

  4. Low molecular weight fucoidan protects renal tubular cells from injury induced by albumin overload.

    PubMed

    Jia, Yingli; Sun, Yi; Weng, Lin; Li, Yingjie; Zhang, Quanbin; Zhou, Hong; Yang, Baoxue

    2016-01-01

    Albuminuria is a causative and aggravating factor for progressive renal damage in chronic kidney disease (CKD). The aim of this study was to determine if low molecular weight fucoidan (LMWF) could protect renal function and tubular cells from albumin overload caused injury. Treatment with 10 mg/g bovine serum albumin caused renal dysfunction, morphological changes, and overexpression of inflammation and fibrosis associated proteins in 129S2/Sv mice. LMWF (100 mg/kg) protected against kidney injury and renal dysfunction with decreased blood creatinine by 34% and urea nitrogen by 25%, increased creatinine clearance by 48%, and decreased significantly urinary albumin concentration. In vitro proximal tubule epithelial cell (NRK-52E) model showed that LMWF dose-dependently inhibited overexpression of proinflammatory and profibrotic factors, oxidative stress and apoptosis caused by albumin overload. These experimental results indicate that LMWF protects against albumin overload caused renal injury by inhibiting inflammation, fibrosis, oxidative stress and apoptosis, which suggests that LMWF could be a promising candidate drug for preventing CKD. PMID:27545472

  5. Dragline silk: a fiber assembled with low-molecular-weight cysteine-rich proteins.

    PubMed

    Pham, Thanh; Chuang, Tyler; Lin, Albert; Joo, Hyun; Tsai, Jerry; Crawford, Taylor; Zhao, Liang; Williams, Caroline; Hsia, Yang; Vierra, Craig

    2014-11-10

    Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. However, the mechanical properties of synthetic spider silks spun from recombinant MaSp1 and MaSp2 proteins have yet to approach natural fibers, implying the natural spinning dope is missing critical factors. Here we report the discovery of novel molecular constituents within the spinning dope that are extruded into dragline silk. Protein studies of the liquid spinning dope from the major ampullate gland, coupled with the analysis of dragline silk fibers using mass spectrometry, demonstrate the presence of a new family of low-molecular-weight cysteine-rich proteins (CRPs) that colocalize with the MA fibroins. Expression of the CRP family members is linked to dragline silk production, specifically MaSp1 and MaSp2 mRNA synthesis. Biochemical data support that CRP molecules are secreted into the spinning dope and assembled into macromolecular complexes via disulfide bond linkages. Sequence analysis supports that CRP molecules share similarities to members that belong to the cystine slipknot superfamily, suggesting that these factors may have evolved to increase fiber toughness by serving as molecular hubs that dissipate large amounts of energy under stress. Collectively, our findings provide molecular details about the components of dragline silk, providing new insight that will advance materials development of synthetic spider silk for industrial applications. PMID:25259849

  6. Study on antithrombotic and antiplatelet activities of low molecular weight fucoidan from Laminaria japonica

    NASA Astrophysics Data System (ADS)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue

    2012-06-01

    The antithrombotic and antiplatelet effects of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica were compared in order to examine the influence of chemical character on their antithrombotic activity and the possible mechanism. Both LMW fucoidan fractions exhibited favorable antithrombotic activity in an Fecl3-induced arterial thrombosis. The antithrombotic activity of LMW fucoidan was related with decrease of TXB2 and whole blood viscosity and hematocrit. LMW fucoidan showed a correlation between anticoagulant, antiaggregant and antithrombotic effects in vivo. For LMW fucoidan, antithrombotic activity required high dose of 5-10 nmol kg-1, concomitantly with increase in anticoagulant activity and inhibition of platelet aggregation. Administration of LMW fucoidan significantly promoted the 6-keto-PGF1α content and decreased the TXB2 content, indicating its inhibition of tissue factor pathway and regulation of metabolism of arachidonic acid. By comparison, highly sulfated fucoidan LF2 with Mw 3900 seemed to be a more suitable choice for antithrombotic drug for its antithrombotic activity accompanied with specific inhibitory activity on platelet aggregation, low anticoagulant activity and low hemorrhagic risk in vivo.

  7. Heparanase and Syndecan-4 Are Involved in Low Molecular Weight Fucoidan-Induced Angiogenesis

    PubMed Central

    Haddad, Oualid; Guyot, Erwan; Marinval, Nicolas; Chevalier, Fabien; Maillard, Loïc; Gadi, Latifa; Laguillier-Morizot, Christelle; Oudar, Olivier; Sutton, Angela; Charnaux, Nathalie; Hlawaty, Hanna

    2015-01-01

    Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases. PMID:26516869

  8. Low-molecular-weight metabolites secreted by Paenibacillus larvae as potential virulence factors of American foulbrood.

    PubMed

    Schild, Hedwig-Annabell; Fuchs, Sebastian W; Bode, Helge B; Grünewald, Bernd

    2014-04-01

    The spore-forming bacterium Paenibacillus larvae causes a severe and highly infective bee disease, American foulbrood (AFB). Despite the large economic losses induced by AFB, the virulence factors produced by P. larvae are as yet unknown. To identify such virulence factors, we experimentally infected young, susceptible larvae of the honeybee, Apis mellifera carnica, with different P. larvae isolates. Honeybee larvae were reared in vitro in 24-well plates in the laboratory after isolation from the brood comb. We identified genotype-specific differences in the etiopathology of AFB between the tested isolates of P. larvae, which were revealed by differences in the median lethal times. Furthermore, we confirmed that extracts of P. larvae cultures contain low-molecular-weight compounds, which are toxic to honeybee larvae. Our data indicate that P. larvae secretes metabolites into the medium with a potent honeybee toxic activity pointing to a novel pathogenic factor(s) of P. larvae. Genome mining of P. larvae subsp. larvae BRL-230010 led to the identification of several biosynthesis gene clusters putatively involved in natural product biosynthesis, highlighting the potential of P. larvae to produce such compounds. PMID:24509920

  9. Holographic studies of azobenzene-containing low-molecular-weight organic glasses

    NASA Astrophysics Data System (ADS)

    Audorff, Hubert; Walker, Roland; Kador, Lothar; Schmidt, Hans-Werner

    2009-02-01

    The formation of phase and surface relief gratings in low-molecular-weight organic glasses containing azobenzene moieties has been studied with holographic methods. Advantages of this class of materials are the simple synthesis, the perfectly amorphous phase, and the possibility of blending them with polymers. Surface relief gratings are formed very efficiently in molecular glasses, and this process can be explained by the gradient force model. Heights up to 610 nm were measured; the temporal evolution of the diffraction efficiency could be reproduced in computer simulations. For technical applications, the surface relief gratings can easily be duplicated by replica molding. Since surface gratings are detrimental to holographic data storage at high densities, it is also possible to suppress their formation by using proper polarizations of the writing beams. Reorientation of the azobenzene groups in the bulk of the glasses and angular multiplexing was demonstrated and the thermal stability of the corresponding phase gratings was studied. Different combinations of molecular cores and substituents at the azobenzene moieties were investigated to find the best systems which yield a high sensitivity and fast grating build-up.

  10. Synthesis of low molecular weight thiols in response to Cd exposure in Thlaspi caerulescens.

    PubMed

    Hernández-Allica, J; Garbisu, C; Becerril, J M; Barrutia, O; García-Plazaola, J I; Zhao, F J; Mcgrath, S P

    2006-07-01

    In this study, we investigated the accumulation of phytochelatins (PCs) and other low molecular weight (LMW) thiols in response to Cd exposure in two contrasting ecotypes differing in Cd accumulation. Using a root elongation test, we found that the highly accumulating ecotype Ganges was more tolerant to Cd than the low Cd-accumulation ecotype Prayon. L-buthionine-(S,R)-sulphoximine (BSO), a potent inhibitor of the gamma-glutamylcysteine synthetase gamma-ECS) (an enzyme involved in the PC biosynthetic pathway), increased the Cd sensitivity of Prayon, but had no effect on Ganges. Although PC accumulation increased in response to Cd exposure, no significant differences were observed between the two ecotypes. Cd exposure induced a dose-dependent accumulation of both Cys and a still unidentified LMW thiol in roots of both ecotypes. Root accumulation of Cys and this thiol was higher in Ganges than in Prayon; the ecotypic differences were more pronounced when the plants were treated with BSO. These findings suggest that PCs do not contribute to the Cd hypertolerance displayed by the Ganges ecotype of Thlaspi caerulescens, whereas Cys and other LMW thiols might be involved. PMID:17080963

  11. [Rapidly labelled low molecular weight components in nucleic acid preparations from plant cells].

    PubMed

    Richter, G; Grotha, R

    1974-09-01

    After pulse-labelling with [(3)H]nucleosides and [(3)H]orotic acid of freely suspended callus cells of Petroselinum sativum and tissue fragments of the liverwort Riella helicophylla, rapidly labelled low molecular weight components were detected among the total nucleic acids when these were extracted in the presence of Mg(2+) and finally precipitated with alcohol. These highly labelled species could clearly be distinguished from the 5 S- and 4 S-RNA on the basis of their migration in agarose-polyacrylamide gels (2.4%) and their elution from Sephadex G-150 columns. No degradation was obtained with DNase and RNase. By using [(14)C]ATP as a marker it was found that the low molecular components consisted mainly of nucleoside triphosphates. Only small amounts of nucleoside diphosphates were detected, which were obviously formed by degradation of the former. Nucleic acid preparations free of nucleoside phosphates were obtained by using Mg-free extraction buffers containing EDTA. PMID:24458196

  12. Epoxy resin synthesis using low molecular weight lignin separated from various lignocellulosic materials.

    PubMed

    Asada, Chikako; Basnet, Sunita; Otsuka, Masaya; Sasaki, Chizuru; Nakamura, Yoshitoshi

    2015-03-01

    A low molecular weight lignin from various lignocellulosic materials was used for the synthesis of bio-based epoxy resins. The lignin extracted with methanol from steam-exploded samples (steaming time of 5 min at steam pressure of 3.5 MPa) from different biomasses (i.e., cedar, eucalyptus, and bamboo) were functionalized by the reaction with epichlorohydrin, catalyzed by a water-soluble phase transfer catalyst tetramethylammonium chloride, which was further reacted with 30 wt% aqueous NaOH for ring closure using methyl ethyl ketone as a solvent. The glycidylated products of the lignin with good yields were cured to epoxy polymer networks with bio-based curing agents i.e., lignin itself and a commercial curing agent TD2131. Relatively good thermal properties of the bio-based epoxy network was obtained and thermal decomposition temperature at 5% weight loss (Td5) of cedar-derived epoxy resin was higher than that derived from eucalyptus and bamboo. The bio-based resin satisfies the stability requirement of epoxy resin applicable for electric circuit boards. The methanol-insoluble residues were enzymatically hydrolyzed to produce glucose. This study indicated that the biomass-derived methanol-soluble lignin may be a promising candidate to be used as a substitute for petroleum-based epoxy resin derived from bisphenol A, while insoluble residues may be processed to give a bioethanol precursor i.e., glucose. PMID:25572718

  13. Determination of low molecular weight organic acids in soil, plants, and water by capillary zone electrophoresis.

    PubMed

    Li, Ying-Hui; Huang, Bi-Xia; Shan, Xiao-Quan

    2003-03-01

    Determination of low molecular weight organic acids in soils and plants by capillary zone electrophoresis was accomplished using a phthalate buffer and indirect UV detection mode. The influence of some crucial parameters, such as pH, buffer concentration and surfactant were investigated. A good separation of seven organic acids was achieved within 5 min using an electrolyte containing 15 mmol L(-1) potassium hydrogen phthalate, 0.5 mmol L(-1) myristyltrimethylammonium bromide (MTAB), and 5% methanol (MeOH) (v/v) at pH 5.60, separation voltage -20 kV, and temperature 25 degrees C. The relative standard deviation (n=5) of the method was found to be in range 0.18-0.56% for migration time and 3.2-4.8% for peak area. The limit of detection ranged between 0.5 micro mol L(-1) to 6 micro mol L(-1) at a signal-to-noise ratio of 3. The recovery of standard organic acids added to real samples ranged from 87 to 119%. This method was simple, rapid and reproducible, and could be applied to the simultaneous determination of organic acids in environmental samples. PMID:12664177

  14. Low molecular weight IgM in selective IgA deficiency.

    PubMed Central

    Kwitko, A O; Roberts-Thomson, P J; Shearman, D J

    1982-01-01

    Thirty-nine persons with selective IgA deficiency were studied. These comprised 27 subjects found by population screening and 12 by other means. Low molecular weight (LMW) serum IgM was sought in 28 of the 39 persons. Nine of the 28 (32%) had LMW IgM detectable by a sensitive gel filtration technique. Of 17 patients discovered by screening, five (29%) had LMW IgM. In the nine positive persons, LMW IgM constituted up to 17% of the total serum IgM concentration. Eight of the nine IgA deficient persons with LMW IgM, had clinical disease while associated disease in the entire IgA deficient population was less frequent. Serum immune complexes were demonstrated in five of seven subjects with LMW IgM using a C1q-dependent radioimmunoassay; four of these had immune complex associated disorders, three with polyarthritis and one with glomerulonephritis. Because circulating immune complexes are frequently detected in IgA deficient persons without disease, it is proposed that the presence of LMW serum IgM in IgA deficiency may be associated with disease due to the formation of specific pathogenic immune complexes. PMID:7172505

  15. In vivo endothelial siRNA delivery using polymeric nanoparticles with low molecular weight

    PubMed Central

    Khan, Omar; Thiriot, Aude; Jhunjunwala, Siddharth; Shaw, Taylor E.; Xing, Yiping; Sager, Hendrik B.; Sahay, Gaurav; Speciner, Lauren; Bader, Andrew; Bogorad, Roman L.; Yin, Hao; Racie, Tim; Dong, Yizhou; Jiang, Shan; Seedorf, Danielle; Dave, Apeksha; Sandu, Kamaljeet S.; Webber, Matthew J.; Novobrantseva, Tatiana; Ruda, Vera M.; Lytton-Jean, Abigail K.R.; Levins, Christopher G.; Kalish, Brian; Mudge, Dayna K.; Perez, Mario; Abezgauz, Ludmila; Dutta, Partha; Smith, Lynelle; Charisse, Klaus; Kieran, Mark W.; Fitzgerald, Kevin; Nahrendorf, Matthias; Danino, Dganit; Tuder, Rubin M.; von Andrian, Ulrich H.; Akinc, Akin; Schroeder, Avi; Panigrahy, Dipak; Kotelianski, Victor; Langer, Robert; Anderson, Daniel G.

    2014-01-01

    Dysfunctional endothelium contributes to more disease than any other tissue in the body. Small interfering RNAs (siRNAs) have the potential to help study and treat endothelial cells in vivo by durably silencing multiple genes simultaneously, but efficient siRNA delivery has so far remained challenging. Here we show that polymeric nanoparticles made of low molecular weight polyamines and lipids can deliver siRNA to endothelial cells with high efficiency, thereby facilitating the simultaneous silencing of multiple endothelial genes in vivo. Unlike lipid or lipid-like nanoparticles, this formulation does not significantly reduce gene expression in hepatocytes or immune cells even at the dosage necessary for endothelial gene silencing. It mediates the most durable non-liver silencing reported to date, and facilitates the delivery of siRNAs that modify endothelial function in mouse models of vascular permeability, emphysema, primary tumour growth, and metastasis. We believe these nanoparticles improve the ability to study endothelial gene function in vivo, and may be used to treat diseases caused by vascular dysfunction. PMID:24813696

  16. Relationship between Extracellular Low-Molecular-Weight Thiols and Mercury Species in Natural Lake Periphytic Biofilms.

    PubMed

    Leclerc, Maxime; Planas, Dolors; Amyot, Marc

    2015-07-01

    The uptake of mercury by microorganisms is a key step in the production of methylmercury, a biomagnifiable toxin. Mercury complexation by low-molecular-weight (LMW) thiols can affect its bioavailability and thus the production of methylmercury. Freshwater biofilms were sampled in the summer using artificial Teflon substrates submerged for over a year to allow natural community colonization in the littoral zone of a Boreal Shield lake. Inside biofilms, concentrations of different extracellular thiol species (thioglycolic acid, l-cysteine-l-glycine, cysteine, and glutathione) were up to 3 orders of magnitude greater than in the surrounding water column, potentially more readily controlling mercury speciation than in the water column. All biofilm thiols except thioglycolic acid were highly correlated to chlorophyll a, likely indicating an algal origin. Extracellular total mercury represented 3 ± 1% of all biofilm mercury and was preferentially found in the capsular fraction. Levels of LMW thiols of presumed algal origins were highly correlated with total mercury in the mobile colloidal fraction of biofilms. We propose that periphytic phototrophic microorganisms such as algae likely affect the bioavailability of mercury through the exudation of LMW thiols, and thus they may play a key role in the production of methylmercury in biofilms. PMID:26011687

  17. Low-Molecular-Weight Polyethyleneimine Grafted Polythiophene for Efficient siRNA Delivery

    PubMed Central

    He, Pan; Hagiwara, Kyoji; Chong, Hui; Yu, Hsiao-hua; Ito, Yoshihiro

    2015-01-01

    Owing to its hydrophilicity, negative charge, small size, and labile degradation by endogenous nucleases, small interfering RNA (siRNA) delivery must be achieved by a carrier system. In this study, cationic copolymers composed of low-molecular-weight polyethylenimine and polythiophenes were synthesized and evaluated as novel self-tracking siRNA delivery vectors. The concept underlying the design of these copolymers is that hydrophobicity and rigidity of polythiophenes should enhance the transport of siRNA across the cell membrane and endosomal membrane. A gel retardation assay showed that the nanosized complexes formed between the copolymers and siRNA were stable even at a molar ratio of 1 : 2. The high cellular uptake (>80%) and localization of the copolymer vectors inside the cells were easily analyzed by tracking the fluorescence of polythiophene using fluorescent microscopy and cytometry. An in vitro luciferase knockdown (KD) assay in A549-luc cells demonstrated that the siRNA complexes with more hydrophobic copolymers achieved a higher KD efficiency of 52.8% without notable cytotoxicity, indicating protein-specific KD activity rather than solely the cytotoxicity of the materials. Our polythiophene copolymers should serve as novel, efficient, low cell toxicity, and label-free siRNA delivery systems. PMID:26539490

  18. Stabilization of fenofibrate in low molecular weight hydroxypropylcellulose matrices produced by hot-melt extrusion.

    PubMed

    Deng, Weibin; Majumdar, Soumyajit; Singh, Abhilasha; Shah, Sejal; Mohammed, Noorullah Naqvi; Jo, Seongbong; Pinto, Elanor; Tewari, Divya; Durig, Thomas; Repka, Michael A

    2013-02-01

    The objective of this study was to improve the dissolution rate and to enhance the stability of a poorly water-soluble and low glass-trasition temperature (T(g)) model drug, fenofibrate, in low molecular weight grades of hydroxypropylcellulose matrices produced by hot-melt extrusion (HME). Percent drug loading had a significant effect on the extrudability of the formulations. Dissolution rate of fenofibrate from melt extruded pellets was faster than that of the pure drug (p < 0.05). Incorporation of sugars within the formulation further increased the fenofibrate release rates. Differential scanning calorimetry results revealed that the crystalline drug was converted into an amorphous form during the HME process. Fenofibrate is prone to recrystallization due to its low T(g). Various polymers were evaluated as stabilizing agents among which polyvinylpyrrolidone 17PF and amino methacrylate copolymer exhibited a significant inhibitory effect on fenofibrate recrystallization in the hot-melt extrudates. Subsequently immediate-release fenofibrate tablets were successfully developed and complete drug release was achieved within 5 min. The dissolution profile was comparable to that of a currently marketed formulation. The hot-melt extruded fenofibrate tablets were stable, and exhibited an unchanged drug release profile after 3-month storage at 40°C/75% RH. PMID:22524504

  19. Hydrogen bonding in DPD: application to low molecular weight alcohol-water mixtures.

    PubMed

    Kacar, Gokhan; de With, Gijsbertus

    2016-04-14

    In this work we propose a computational approach to mimic hydrogen bonding in a widely used coarse-grained simulation method known as dissipative particle dynamics (DPD). The conventional DPD potential is modified by adding a Morse potential term to represent hydrogen bonding attraction. Morse potential parameters are calculated by a mapping of energetic and structural properties to those of atomistic scale simulations. By the addition of hydrogen bonding to DPD and with the proposed parameterization, the volumetric mixing behavior of low molecular weight alcohols and water is studied and experimentally observed negative volume excess is successfully predicted, contrary to the conventional DPD implementation. Moreover, the density-dependent DPD parameterization employed provides the asymmetrical shapes of the excess volume curves. In addition, alcohol surface enrichment at the air interface and self-assembly in the bulk is studied. The surface concentrations of alcohols at the air interface compare favorably with the experimental observations at all bulk-phase alcohol fractions and, in consonance with experiment, some clustering is observed. PMID:26986630

  20. Tailoring a low-molecular weight protein tyrosine phosphatase into an efficient reporting protein

    SciTech Connect

    Liu, Xiao-Yan; Li, Lan-Fen; Su, Xiao-Dong; Shenzhen Graduate School of Peking University, Shenzhen 518055

    2009-05-15

    Fusion reporter methods are important tools for biology and biotechnology. An ideal reporter protein in a fusion system should have little effects on its fusion partner and provide an easy and accurate readout. Therefore, a small monomeric protein with high activity for detection assays often has advantages as a reporter protein. For this purpose, we have tailored the human B-form low-molecular-weight phosphotyrosyl phosphatase (HPTP-B) to increase its general applicability as a potent reporter protein. With the aim to eliminate interference from cysteine residues in the native HPTP-B, combined with a systematic survey of N- and C-terminal truncated variants, a series of cysteine to serine mutations were introduced, which allowed isolation of an engineered soluble protein with suitable biophysical properties. When we deleted both the first six residues and the last two residues, we still obtained a soluble mutant protein with correct folding and similar activity with wild-type protein. This mutant with two cysteine to serine mutations, HPTP-B{sup N{sub {Delta}}6-C{sub {Delta}}2-C90S-C109S}, has good potential as an optimal reporter.

  1. Activation of the Low Molecular Weight Protein Tyrosine Phosphatase in Keratinocytes Exposed to Hyperosmotic Stress

    PubMed Central

    Cavalheiro, Renan P.; Machado, Daisy; Cruz, Bread L. G.; Paredes-Gamero, Edgar J.; Gomes-Marcondes, Maria C. C.; Zambuzzi, Willian F.; Vasques, Luciana; Nader, Helena B.; Souza, Ana Carolina S.; Justo, Giselle Z.

    2015-01-01

    Herein, we provide new contribution to the mechanisms involved in keratinocytes response to hyperosmotic shock showing, for the first time, the participation of Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP) activity in this event. We reported that sorbitol-induced osmotic stress mediates alterations in the phosphorylation of pivotal cytoskeletal proteins, particularly Src and cofilin. Furthermore, an increase in the expression of the phosphorylated form of LMWPTP, which was followed by an augment in its catalytic activity, was observed. Of particular importance, these responses occurred in an intracellular milieu characterized by elevated levels of reduced glutathione (GSH) and increased expression of the antioxidant enzymes glutathione peroxidase and glutathione reductase. Altogether, our results suggest that hyperosmostic stress provides a favorable cellular environment to the activation of LMWPTP, which is associated with increased expression of antioxidant enzymes, high levels of GSH and inhibition of Src kinase. Finally, the real contribution of LMWPTP in the hyperosmotic stress response of keratinocytes was demonstrated through analysis of the effects of ACP1 gene knockdown in stressed and non-stressed cells. LMWPTP knockdown attenuates the effects of sorbitol induced-stress in HaCaT cells, mainly in the status of Src kinase, Rac and STAT5 phosphorylation and activity. These results describe for the first time the participation of LMWPTP in the dynamics of cytoskeleton rearrangement during exposure of human keratinocytes to hyperosmotic shock, which may contribute to cell death. PMID:25781955

  2. Enhanced gene delivery of low molecular weight PEI by flower-like ZnO microparticles.

    PubMed

    Chen, Ming; Tang, Yaqin; Wang, Tingting; Long, Qipeng; Zeng, Ziying; Chen, Houwen; Feng, Xuli

    2016-12-01

    Low molecular weight (1.8 kDa) branched polyethylenimine (PEI) has been used as non-viral vector for gene delivery because of its low toxicity, however, its further application in biomedical field has been restricted due to its low gene transfection efficiency. Herein, ZnO microflowers were prepared to increase the gene expression level mediated by PEI. Four methods have been applied to tune the shape of ZnO microstructures. Scanning electron microscopy (SEM) demonstrated the successful preparation of four kinds of flower like ZnO microparticles. By loading PEI/pDNA into ZnO microparticles, the formed new complexes showed enhanced gene transfection compared to PEI/pDNA alone. Cell uptaking experiments explained a possible mechanism that the tips of ZnO microflowers penetrated into the surface of cells, thus facilitating the entry of gene cargo into cells. These findings highlight the potential of needle like microstructure as adjuvant for efficient biomacromolecular delivery. PMID:27612838

  3. How does low-molecular-weight polystyrene dissolve: osmotic swelling vs. surface dissolution.

    PubMed

    Marcon, Valentina; van der Vegt, Nico F A

    2014-12-01

    By means of multiscale hierarchical modeling we study the real time evolution of low-molecular-weight polystyrene, below the glass transition temperature, in contact with its solvent, toluene. We observe two concurrent phenomena taking place: (1) the solvent diffuses into the polymer by a Case II mechanism, leading to osmotic driven swelling and progressive chain dilution (inside-out mechanism); (2) polymer chains are solvated, detach from the interface and move into the solvent before the film is completely swollen (outside-in mechanism). From our simulations we conclude that, below the entanglement length, a thin swollen layer, also observed in previous experiments, forms almost instantaneously, which allows for the outside-in mechanism to start a few tens of nanoseconds after the polymer-solvent initial contact. After this initial transient time the two mechanisms are concurrent. We furthermore observe that the presence of the solvent significantly enhances the mobility of the polymer chains of the surface layer, but only in the direction parallel to the interface. PMID:25300931

  4. Anticoagulant and antithrombotic activities of low-molecular-weight propylene glycol alginate sodium sulfate (PSS).

    PubMed

    Xin, Meng; Ren, Li; Sun, Yang; Li, Hai-hua; Guan, Hua-Shi; He, Xiao-Xi; Li, Chun-Xia

    2016-05-23

    Propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide derivative, has been used as a heparinoid drug to prevent and treat hyperlipidemia and ischemic cardio-cerebrovascular diseases in China for nearly 30 years. To extend the applications of PSS, a series of low-molecular-weight PSSs (named FPs) were prepared by oxidative-reductive depolymerization, and the antithrombotic activities were investigated thoroughly in vitro and in vivo. The bioactivity evaluation demonstrated a positive correlation between the molecular weight and the anticoagulant and antithrombotic activities of FPs. FPs could prolong the APTT and clotting time and reduce platelet aggregation significantly. FPs could also effectively inhibit factor IIa in the presence of AT-III and HC-II. FPs decreased the wet weights and lengths of the thrombus and increased occlusion times in vivo. FP-6k, a PSS fragment with a molecular weight of 6 kDa, is an optimal antithrombotic candidate for further study and showed little chance for hemorrhagic action. PMID:26974373

  5. Citric acid mediates the iron absorption from low molecular weight human milk fractions.

    PubMed

    Palika, Ravindranadh; Mashurabad, Purna Chandra; Kilari, Sreenivasulu; Kasula, Sunanda; Nair, Krishnapillai Madhavan; Raghu, Pullakhandam

    2013-11-20

    Previously, we have demonstrated increased iron absorption from low molecular weight (LMW) human milk whey fractions. In the present study, we investigated the effect of heat denaturation, zinc (a competitor of iron), duodenal cytochrome b (DcytB) antibody neutralization and citrate lyase treatment on LMW human milk fraction (>5 kDa referred as 5kF) induced ferric iron reduction, solubilization, and uptake in Caco-2 cells. Heat denaturation and zinc inhibited the 5kF fraction induced ferric iron reduction. In contrast, zinc but not heat denaturation abrogated the ferric iron solubilization activity. Despite inhibition of ferric iron reduction, iron uptake in Caco-2 cells was similar from both native and heat denatured 5kF fractions. However, iron uptake was higher from native compared to heat denatured 5kF fractions in the cells preincubated with the DcytB antibody. Citrate lyase treatment inhibited the ferric iron reduction, solubilization, and uptake in Caco-2 cells. These findings demonstrate that citric acid present in human milk solubilizes the ferric iron which could be reduced by other heat labile components leading to increased uptake in intestinal cells. PMID:24160751

  6. Characterization of low molecular weight allergens from English walnut (Juglans regia).

    PubMed

    Downs, Melanie L; Semic-Jusufagic, Aida; Simpson, Angela; Bartra, Joan; Fernandez-Rivas, Montserrat; Rigby, Neil M; Taylor, Steve L; Baumert, Joseph L; Mills, E N Clare

    2014-12-01

    Although English walnut is a commonly allergenic tree nut, walnut allergens have been poorly characterized to date. The objective of this work was to characterize the natural, low molecular weight (LMW) allergens from walnut. A protocol was developed to purify LMW allergens (specifically 2S albumins) from English walnuts. In addition to 2S albumins, a series of peptides from the N-terminal region of the 7S seed storage globulin proprotein were also identified and characterized. These peptides comprised a four-cysteine motif (C-X-X-X-C-X10-12-C-X-X-X-C) repeated throughout the 7S N-terminal region. Upon IgE immunoblotting, 3/11 and 5/11 sera from walnut-allergic subjects showed IgE reactivity to the 7S N-terminal fragments and 2S albumin, respectively. The mature 7S protein and the newly described 7S N-terminal peptides represent two distinct types of allergens. Because the proteolytic processing of 7S globulins has not been elucidated in many edible plant species, similar protein fragments may be present in other nuts and seeds. PMID:25388987

  7. Impact of low molecular weight organic acids (LMWOAs) on biochar micropores and sorption properties for sulfamethoxazole.

    PubMed

    Sun, Binbin; Lian, Fei; Bao, Qiongli; Liu, Zhongqi; Song, Zhengguo; Zhu, Lingyan

    2016-07-01

    The interaction between biochar (BC) and antibiotics with the presence of low molecular weight organic acids (LMWOAs) is largely unknown, although it is crucial for understanding the role of BC in reducing the bioavailability of antibiotics in rhizosphere. The impacts of two typical LMWOAs (citric and malic acids) on sorption of sulfamethoxazole (SMX) by crop-straw BCs produced at 300 °C (BCs300) and 600 °C (BCs600), respectively, were examined. The sorption of SMX on BCs increased more than 5 times with the concentration of LMWOAs increasing from 0 to 100 mmol/L, which was mainly attributed to the elevated microporosity of BCs (measured by CO2) after treated by LMWOAs. The pore development of BCs was mainly derived from the release of dissolved organic residues from BC by LMWOA washing. For H2O2-oxidized BCs, however, LMWOAs had little effect on SMX sorption by BCs300 but greatly increased that by BCs600, which can be explained by the distinct sorption mechanisms of SMX on BCs300 and BCs600. These results indicate that the impact of LMWOAs on SMX sorption is highly dependent on the properties of BCs and LMWOAs, as well as their interaction mechanisms. PMID:27077553

  8. Occupational asthma secondary to low molecular weight agents used in the plastic and resin industries.

    PubMed

    Bardana, E J; Andrach, R H

    1983-05-01

    The rapid proliferation of complex plastic polymers and resins has led to a marked increase of work-induced asthma due to low molecular weight agents. Phthalates are frequently used in the manufacture of epoxy resins, plasticizers, adhesives and a wide variety of other materials. They have recently been identified as an important irritant and immunogen of at least four occupational respiratory syndromes, i.e., asthma/rhinitis, late respiratory systemic syndrome, pulmonary disease-anemia syndrome, and an irritant reaction. Isocyanates are extensively employed in the production of polyurethane foams, adhesives, paints and other plastic products. They have been incriminated in the causation of occupational lung disease since 1951. It appears that both specific IgE-mediated and non-specific irritant mechanisms are operative in isocyanate-induced asthma. Formaldehyde is a widely used irritating chemical, mainly employed as disinfectant or in the production of multiple resin products employed in the wood, shoe, and clothing industries. Several of these resin products can give off formaldehyde fumes causing occupational and non-occupational dermatitis, urticaria, bronchitis and reactive airway disease. Colophony pine resin used in virtually all soft soldering fluxes, and paraphenylene diamine used in the fur, paint and rubber industries have also been implicated in the generation of industrial asthma. Awareness of where such agents are likely to be encountered, together with patterns of respiratory disease induced, should facilitate earlier diagnosis. PMID:6861919

  9. Low molecular weight fucoidan protects renal tubular cells from injury induced by albumin overload

    PubMed Central

    Jia, Yingli; Sun, Yi; Weng, Lin; Li, Yingjie; Zhang, Quanbin; Zhou, Hong; Yang, Baoxue

    2016-01-01

    Albuminuria is a causative and aggravating factor for progressive renal damage in chronic kidney disease (CKD). The aim of this study was to determine if low molecular weight fucoidan (LMWF) could protect renal function and tubular cells from albumin overload caused injury. Treatment with 10 mg/g bovine serum albumin caused renal dysfunction, morphological changes, and overexpression of inflammation and fibrosis associated proteins in 129S2/Sv mice. LMWF (100 mg/kg) protected against kidney injury and renal dysfunction with decreased blood creatinine by 34% and urea nitrogen by 25%, increased creatinine clearance by 48%, and decreased significantly urinary albumin concentration. In vitro proximal tubule epithelial cell (NRK-52E) model showed that LMWF dose-dependently inhibited overexpression of proinflammatory and profibrotic factors, oxidative stress and apoptosis caused by albumin overload. These experimental results indicate that LMWF protects against albumin overload caused renal injury by inhibiting inflammation, fibrosis, oxidative stress and apoptosis, which suggests that LMWF could be a promising candidate drug for preventing CKD. PMID:27545472

  10. Patient's Guide to Antithrombotic and Thrombolytic Therapy

    MedlinePlus

    ... X Low-molecular-weight heparin X Fondaparinux X Warfarin (Coumadin) X Dabigatran (Pradaxa) X Rivaroxaban (Xarelto) X ... features of these blood thinners? X Heparin and warfarin have been used for more than 50 years, ...

  11. The in vitro and in vivo effects of the low molecular weight fucoidan on the bone osteogenic differentiation properties.

    PubMed

    Hwang, Pai-An; Hung, Yu-Lan; Phan, Nam Nhut; Hieu, Bui-Thi-Ngoc; Chang, Po-Ming; Li, Kuan-Lun; Lin, Yen-Chang

    2016-08-01

    Osteoporosis has been reported as a hidden death factor in aged people. So far, prevention and treatment therapies for osteoporosis only slow down the progress but do not treat the disease. Fucoidan has been recognized its roles in anti-tumor, anti-inflammatory, anti-coagulant and antiviral activities. To date, low molecular weight (LMW) fucoidan role in bone loss disease has been not determined yet. Therefore, this study aims to figure out potential effects of LMW fucoidan in osteoporosis in vitro and in vivo. LMW fucoidan was extracted from fresh Sargassum hemiphyllum showing a significant increase in 7F2 cell viability to 150.33 ± 6.50 % relative to normal fucoidan (130.12 ± 5.74 %). The expression of level BMP-2, ALP, osteocalcin significantly increased with 2.28 ± 0.06, 2.18 ± 0.12 and 2.06 ± 0.07 fold, respectively. The RT-PCR assay showed that LMW fucoidan increased mRNA expression of BMP-2, ALP, osteocalcin, COL I, BSP and osteonectin. Furthermore, the bone density and bone ash weight were considerably boosted by the oral administration of 280 mg/kg LMW fucoidan and 100 mg/kg calcium carbonate in C57BL/6J female aged mice. The present finding indicated that LMW fucoidan triggered osteogenic differentiation in vitro, and had an anabolic effect on bone mineralization in vivo. Dietary intake of LMW fucoidan from S. hemiphyllum suggested playing a role in the enhancement of bone loss with increasing age. PMID:26271462

  12. Application of computer-assisted molecular modeling (CAMM) for immunoassay of low molecular weight food contaminants: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassay for low molecular weight food contaminants, such as pesticides, veterinary drugs, and mycotoxins is now a well-established technique which meets the demands for a rapid, reliable, and cost-effective analytical method. However, due to limited understanding of the fundamental aspects of i...

  13. A MURINE MODEL FOR LOW MOLECULAR WEIGHT CHEMICALS: DIFFERENTIATION OF RESPIRATORY SENSITIZERS (TMA) FROM CONTACT SENSITIZERS (DNFB)

    EPA Science Inventory

    Exposure to low molecular weight (LMW) chemicals contributes to both dermal and respiratory sensitization and is an important occupational health problem. Our goal was to establish an in vivo murine model for hazard identification of LMW chemicals that have the potential to indu...

  14. Characterization of the low-molecular-weight glutenin subunit gene family members using a PCR-based marker approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low-molecular-weight glutenin subunits (LMW-GS) are a class of seed storage proteins that play a major role in the determination of the processing quality of wheat flour. The LMW-GS are encoded by multi-gene families located on the short arms of the homoeologous group 1 chromosomes, at the Glu-A3, G...

  15. PRODUCTION OF LOW MOLECULAR WEIGHT CADMIUM-BINDING PROTEINS IN RABBIT LUNG FOLLOWING EXPOSURE TO CADMIUM CHLORIDE

    EPA Science Inventory

    Low molecular weight cadmium-binding proteins were studied in lung tissue from rabbits exposed to aerosols of CdCl2. Lungs obtained from animals exposed by inhalation to aerosols of 800 or 1600 micrograms/cu.m. CdCl2 for 2-hr periods/day, every other day for a 5-day period, were ...

  16. In vitro effects of heparin and tissue factor pathway inhibitor on factor VII assays. possible implications for measurements in vivo after heparin therapy.

    PubMed

    Bladbjerg, E M; Larsen, L F; Ostergaard, P; Jespersen, J

    2000-12-01

    The coagulant activity of blood coagulation factor VII (FVII:C) can be lowered by changes in lifestyle and by therapeutic intervention, e.g. heparin infusion. The question is, however, whether FVII:C determined ex vivo is a valid measure of the FVII activity in vivo. We measured plasma FVII:C, activated FVII (FVIIa), FVII protein (FVII:Ag), tissue factor pathway inhibitor (TFPI), triglycerides, and free fatty acids (FFA) before and 15 min after infusion of a bolus of unfractionated heparin (50 IU/kg body weight) in 12 healthy subjects. Additionally, we conducted in vitro experiments to investigate the effect of unfractionated heparin and TFPI, which is released from the endothelium by heparin, on FVII:C, FVIIa, and FVII:Ag. Heparin infusion decreased triglycerides and increased FFA and TFPI. This was accompanied by significant reductions in FVIIa, FVII:C and FVII:Ag. In vitro, anti-TFPI antibodies increased FVIIa and FVII:C, and heparin reduced FVIIa. The heparinase Hepzyme was unable to abolish the effect of heparin. There were no in vitro effects on FVII:Ag. We conclude that, due to interference by TFPI and heparin in post-heparin plasma, it is impossible to measure the in vivo FVII activity by means of FVII clotting assays. These assays should therefore not be used to measure the coagulation status of patients in heparin therapy, unless extraordinary precautions are taken to eliminate TFPI and heparin effects ex vivo. The observed effect of heparin on FVII:Ag should be investigated further. PMID:11132652

  17. Do Low Molecular Weight Agents Cause More Severe Asthma than High Molecular Weight Agents?

    PubMed Central

    Meca, Olga; Cruz, María-Jesús; Sánchez-Ortiz, Mónica; González-Barcala, Francisco-Javier; Ojanguren, Iñigo; Munoz, Xavier

    2016-01-01

    Introduction The aim of this study was to analyse whether patients with occupational asthma (OA) caused by low molecular weight (LMW) agents differed from patients with OA caused by high molecular weight (HMW) with regard to risk factors, asthma presentation and severity, and response to various diagnostic tests. Methods Seventy-eight patients with OA diagnosed by positive specific inhalation challenge (SIC) were included. Anthropometric characteristics, atopic status, occupation, latency periods, asthma severity according to the Global Initiative for Asthma (GINA) control classification, lung function tests and SIC results were analysed. Results OA was induced by an HMW agent in 23 patients (29%) and by an LMW agent in 55 (71%). A logistic regression analysis confirmed that patients with OA caused by LMW agents had a significantly higher risk of severity according to the GINA classification after adjusting for potential confounders (OR = 3.579, 95% CI 1.136–11.280; p = 0.029). During the SIC, most patients with OA caused by HMW agents presented an early reaction (82%), while in patients with OA caused by LMW agents the response was mainly late (73%) (p = 0.0001). Similarly, patients with OA caused by LMW agents experienced a greater degree of bronchial hyperresponsiveness, measured as the difference in the methacholine dose-response ratio (DRR) before and after SIC (1.77, range 0–16), compared with patients with OA caused by HMW agents (0.87, range 0–72), (p = 0.024). Conclusions OA caused by LMW agents may be more severe than that caused by HMW agents. The severity of the condition may be determined by the different mechanisms of action of these agents. PMID:27280473

  18. Development and in vitro characterization of galactosylated low molecular weight chitosan nanoparticles bearing doxorubicin.

    PubMed

    Jain, Nitin K; Jain, Sanjay K

    2010-06-01

    The aim of the present research was to evaluate the potential of galactosylated low molecular weight chitosan (Gal-LMWC) nanoparticles bearing positively charged anticancer, doxorubicin (DOX) for hepatocyte targeting. The chitosan from crab shell was depolymerized, and the lactobionic acid was coupled with LMWC using carbodiimide chemistry. The depolymerized and galactosylated polymers were characterized. Two types of Gal-LMWC(s) with variable degree of substitution were employed to prepare the nanoparticles using ionotropic gelation with pentasodium tripolyphosphate anions. Factors affecting nanoparticles formation were discussed. The nanoparticles were characterized by transmission electron microscopy and photon correlation spectroscopy and found to be spherical in the size range 106-320 nm. Relatively higher percent DOX entrapment was obtained for Gal-LMWC(s) nanoparticles than for LMWC nanoparticles. A further increase in drug entrapment was found with nanoparticles prepared by Gal-LMWC with higher degree of substitution. A hypothesis which correlates the ionic concentration of DOX in nanoparticles preparation medium and percent DOX entrapment in cationic polymer has been proposed to explain the enhanced DOX entrapment. In-vitro drug release study demonstrated an initial burst release followed by a sustained release. The targeting potential of the prepared nanoparticles was assessed by in vitro cytotoxicity study using the human hepatocellular carcinoma cell line (HepG(2)) expressing the ASGP receptors on their surfaces. The enthusiastic results showed the feasibility of Gal-LMWC(s) to entrap the cationic DOX and targeting potential of developed Gal-LMWC(s) nanoparticles to HepG(2) cell line. PMID:20414758

  19. Low molecular weight chitosan nanoparticulate system at low N:P ratio for nontoxic polynucleotide delivery.

    PubMed

    Alameh, Mohamad; Dejesus, Diogo; Jean, Myriam; Darras, Vincent; Thibault, Marc; Lavertu, Marc; Buschmann, Michael D; Merzouki, Abderrazzak

    2012-01-01

    Chitosan, a natural polymer, is a promising system for the therapeutic delivery of both plasmid DNA and synthetic small interfering RNA. Reports attempting to identify the optimal parameters of chitosan for synthetic small interfering RNA delivery were inconclusive with high molecular weight at high amine-to-phosphate (N:P) ratios apparently required for efficient transfection. Here we show, for the first time, that low molecular weight chitosan (LMW-CS) formulations at low N:P ratios are suitable for the in vitro delivery of small interfering RNA. LMW-CS nanoparticles at low N:P ratios were positively charged (ζ-potential ~20 mV) with an average size below 100 nm as demonstrated by dynamic light scattering and environmental scanning electron microscopy, respectively. Nanoparticles were spherical, a shape promoting decreased cytotoxicity and enhanced cellular uptake. Nanoparticle stability was effective for at least 20 hours at N:P ratios above two in a slightly acidic pH of 6.5. At a higher basic pH of 8, these nanoparticles were unravelled due to chitosan neutralization, exposing their polynucleotide cargo. Cellular uptake ranged from 50% to 95% in six different cell lines as measured by cytometry. Increasing chitosan molecular weight improved nanoparticle stability as well as the ability of nanoparticles to protect the oligonucleotide cargo from nucleases at supraphysiological concentrations. The highest knockdown efficiency was obtained with the specific formulation 92-10-5 that combines sufficient nuclease protection with effective intracellular release. This system attained >70% knockdown of the messenger RNA, similar to commercially available lipoplexes, without apparent cytotoxicity. Contrary to previous reports, our data demonstrate that LMW-CS at low N:P ratios are efficient and nontoxic polynucleotide delivery systems capable of transfecting a plethora of cell lines. PMID:22457597

  20. Mitigation of chlorine-induced lung injury by low-molecular-weight antioxidants

    PubMed Central

    Leustik, Martin; Doran, Stephen; Bracher, Andreas; Williams, Shawn; Squadrito, Giuseppe L.; Schoeb, Trenton R.; Postlethwait, Edward; Matalon, Sadis

    2008-01-01

    Chlorine (Cl2) is a highly reactive oxidant gas used extensively in a number of industrial processes. Exposure to high concentrations of Cl2 results in acute lung injury that may either resolve spontaneously or progress to acute respiratory failure. Presently, the pathophysiological sequelae associated with Cl2-induced acute lung injury in conscious animals, as well as the cellular and biochemical mechanisms involved, have not been elucidated. We exposed conscious Sprague-Dawley rats to Cl2 gas (184 or 400 ppm) for 30 min in environmental chambers and then returned them to room air. At 1 h after exposure, rats showed evidence of arterial hypoxemia, respiratory acidosis, increased levels of albumin, IgG, and IgM in bronchoalveolar lavage fluid (BALF), increased BALF surfactant surface tension, and significant histological injury to airway and alveolar epithelia. These changes were more pronounced in the 400-ppm-exposed rats. Concomitant decreases of ascorbate (AA) and reduced glutathione (GSH) were also detected in both BALF and lung tissues. In contrast, heart tissue AA and GSH content remained unchanged. These abnormalities persisted 24 h after exposure in rats exposed to 400 ppm Cl2. Rats injected systemically with a mixture of AA, deferoxamine, and N-acetyl-l-cysteine before exposure to 184 ppm Cl2 had normal levels of AA, lower levels of BALF albumin and normal arterial Po2 and Pco2 values. These findings suggest that Cl2 inhalation damages both airway and alveolar epithelial tissues and that resulting effects were ameliorated by prophylactic administration of low-molecular-weight antioxidants. PMID:18708632

  1. Can thiolation render a low molecular weight polymer of just 20-kDa mucoadhesive?

    PubMed

    Mahmood, Arshad; Bonengel, Sonja; Laffleur, Flavia; Ijaz, Muhammad; Idrees, Muneeb Ahmad; Hussain, Shah; Huck, Christian W; Matuszczak, Barbara; Bernkop-Schnürch, Andreas

    2016-05-01

    The objective was to investigate whether even low-molecular weight polymers (LMWPs) can be rendered mucoadhesive due to thiolation. Interceded by the double catalytic system carbodiimide/N-hydroxysuccinimide, cysteamine was covalently attached to a copolymer, poly(4-styrenesulfonic acid-co-maleic acid) (PSSA-MA) exhibiting a molecular weight of just 20 kDa. Depending on the amount of added N-hydroxysuccinimide and cysteamine, the resulting PSSA-MA-cysteamine (PC) conjugates exhibited increasing degree of thiolation, highest being "PC 2300" exhibiting 2300.16 ± 149.86 μmol thiol groups per gram of polymer (mean ± SD; n = 3). This newly developed thiolated polymer was evaluated regarding mucoadhesive, rheological and drug release properties as well from the toxicological point of view. Swelling behavior in 100 mM phosphate buffer pH 6.8 was improved up to 180-fold. Furthermore, due to thiolation, the mucoadhesive properties of the polymer were 240-fold improved. Rheological measurements of polymer/mucus mixtures confirmed results obtained by mucoadhesion studies. In comparison to unmodified polymer, PC 2300 showed 2.3-, 2.3- and 2.4-fold increase in dynamic viscosity, elastic modulus and viscous modulus, respectively. Sustained release of the model drug codeine HCl out of the thiomer was provided for 2.5 h (p < 0.05), whereas the drug was immediately released from the unmodified polymer. Moreover, the thiomer was found non-toxic over Caco-2 cells for a period of 6- and 24-h exposure. Findings of the present study provide evidence that due to thiolation LMWPs can be rendered highly mucoadhesive as well as cohesive and that a controlled drug release out of such polymers can be provided. PMID:26133081

  2. Effect of serum albumin and low molecular weight ligands on Zn uptake by isolated rat hepatocytes

    SciTech Connect

    Flynn, A.; Loennerdal, B.

    1986-03-05

    Although the liver plays an important role in Zn metabolism, the mechanisms regulating hepatic Zn uptake are poorly understood. Hepatocytes were isolated from adult female rats, body weight 200-250 g, by the collagenase perfusion technique and purified by differential centrifugation. Uptake of Zn was studied by incubation of hepatocytes with /sup 65/Zn in 10 mM HEPES buffer, pH 7.4, containing 138 mM NaCl, 5.2 mM KCl, 0.9 mM MgCl/sub 2/ and 1.0 mM CaCl/sub 2/, followed by washing with ice-cold 10 mM EDTA, 0.9% NaCl, pH 7.3 on Whatman GF-C glass microfiber filters. Zn uptake of 37/sup 0/C from ZnSO/sub 4/ (10 ..mu..M) was linear up to approx. 5 min with an initial rate of uptake of 11-20 ng/min/10/sup 6/ viable cells. Initial rate of Zn uptake at 37/sup 0/C was over 10-fold greater than at 4/sup 0/C. At 37/sup 0/C initial rate of uptake increased as a function of Zn concentration in the range 2-20 ..mu..M, with K/sub m/ = 27 ..mu..M and V/sub max/ = 42 ng/min/10/sup 6/ viable cells. Inclusion of bovine serum albumin (2 mg/ml) with ZnSO/sub 4/ (10 ..mu..m) reduced the initial rate of uptake to approx. 25% of the rate with ZnSO/sub 4/ alone. The low molecular weight ligands, phosphate, citrate and histidine at equimolar concentrations with Zn had little effect on Zn uptake by hepatocytes.

  3. Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries.

    PubMed

    Sevov, Christo S; Brooner, Rachel E M; Chénard, Etienne; Assary, Rajeev S; Moore, Jeffrey S; Rodríguez-López, Joaquín; Sanford, Melanie S

    2015-11-18

    The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e(-)) or less), and must function with low molecular weight supporting electrolytes such as LiBF4. However, soluble anolyte materials that undergo reversible redox processes in the presence of Li-ion supports are rare. We report the evolutionary design of a series of pyridine-based anolyte materials that exhibit up to two reversible redox couples at low potentials in the presence of Li-ion supporting electrolytes. A combination of cyclic voltammetry of anolyte candidates and independent synthesis of their corresponding charged-states was performed to rapidly screen for the most promising candidates. Results of this workflow provided evidence for possible decomposition pathways of first-generation materials and guided synthetic modifications to improve the stability of anolyte materials under the targeted conditions. This iterative process led to the identification of a promising anolyte material, N-methyl 4-acetylpyridinium tetrafluoroborate. This compound is soluble in nonaqueous solvents, is prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol·e(-)), and undergoes two reversible 1e(-) reductions in the presence of LiBF4 to form reduced products that are stable over days in solution. PMID:26514666

  4. Anti-inflammatory activity of low molecular weight polysialic acid on human macrophages

    PubMed Central

    Shahraz, Anahita; Kopatz, Jens; Mathy, Rene; Kappler, Joachim; Winter, Dominic; Kapoor, Shoba; Schütza, Vlad; Scheper, Thomas; Gieselmann, Volkmar; Neumann, Harald

    2015-01-01

    Oligosialic and polysialic acid (oligoSia and polySia) of the glycocalyx of neural and immune cells are linear chains, in which the sialic acid monomers are α2.8-glycosidically linked. Sialic acid-binding immunoglobulin-like lectin-11 (SIGLEC-11) is a primate-lineage specific receptor of human tissue macrophages and microglia that binds to α2.8-linked oligoSia. Here, we show that soluble low molecular weight polySia with an average degree of polymerization 20 (avDP20) interacts with SIGLEC-11 and acts anti-inflammatory on human THP1 macrophages involving the SIGLEC-11 receptor. Soluble polySia avDP20 inhibited the lipopolysaccharide (LPS)-induced gene transcription and protein expression of tumor necrosis factor-α (Tumor Necrosis Factor Superfamily Member 2, TNFSF2). In addition, polySia avDP20 neutralized the LPS-triggered increase in macrophage phagocytosis, but did not affect basal phagocytosis or endocytosis. Moreover, polySia avDP20 prevented the oxidative burst of human macrophages triggered by neural debris or fibrillary amyloid-β1–42. In a human macrophage-neuron co-culture system, polySia avDP20 also reduced loss of neurites triggered by fibrillary amyloid-β1–42. Thus, treatment with polySia avDP20 might be a new anti-inflammatory therapeutic strategy that also prevents the oxidative burst of macrophages. PMID:26582367

  5. Mitigation of chlorine-induced lung injury by low-molecular-weight antioxidants.

    PubMed

    Leustik, Martin; Doran, Stephen; Bracher, Andreas; Williams, Shawn; Squadrito, Giuseppe L; Schoeb, Trenton R; Postlethwait, Edward; Matalon, Sadis

    2008-11-01

    Chlorine (Cl(2)) is a highly reactive oxidant gas used extensively in a number of industrial processes. Exposure to high concentrations of Cl(2) results in acute lung injury that may either resolve spontaneously or progress to acute respiratory failure. Presently, the pathophysiological sequelae associated with Cl(2)-induced acute lung injury in conscious animals, as well as the cellular and biochemical mechanisms involved, have not been elucidated. We exposed conscious Sprague-Dawley rats to Cl(2) gas (184 or 400 ppm) for 30 min in environmental chambers and then returned them to room air. At 1 h after exposure, rats showed evidence of arterial hypoxemia, respiratory acidosis, increased levels of albumin, IgG, and IgM in bronchoalveolar lavage fluid (BALF), increased BALF surfactant surface tension, and significant histological injury to airway and alveolar epithelia. These changes were more pronounced in the 400-ppm-exposed rats. Concomitant decreases of ascorbate (AA) and reduced glutathione (GSH) were also detected in both BALF and lung tissues. In contrast, heart tissue AA and GSH content remained unchanged. These abnormalities persisted 24 h after exposure in rats exposed to 400 ppm Cl(2). Rats injected systemically with a mixture of AA, deferoxamine, and N-acetyl-L-cysteine before exposure to 184 ppm Cl(2) had normal levels of AA, lower levels of BALF albumin and normal arterial Po(2) and Pco(2) values. These findings suggest that Cl(2) inhalation damages both airway and alveolar epithelial tissues and that resulting effects were ameliorated by prophylactic administration of low-molecular-weight antioxidants. PMID:18708632

  6. The Use of Low Molecular Weight Protamine Chemical Chimera to Enhance Monomeric Insulin Intestinal Absorption

    PubMed Central

    He, Huining; Sheng, Jianyong; David, Allan E.; Kwon, Young Min; Zhang, Jian; Huang, Yongzhuo; Wang, Jianxin; Yang, Victor C.

    2013-01-01

    Although oral delivery of insulin offers a number of unmatched advantages, it nevertheless is beset by the poor permeability of insulin molecules through the epithelial cell membranes of the intestinal mucosal layer. We previously reported the development of low molecular weight protamine (LMWP) as a nontoxic yet potent cell penetrating peptide, of which via covalent linkage was capable of translocating protein cargos through the membranes of almost all cell types. It is therefore hypothesized that LMWP could be practically employed as a safe and effective tool to deliver insulin across the intestinal mucosal membrane, thereby augmenting its absorption through the GI tract. However, formulating 1:1 monomeric insulin/LMWP conjugate presents a tall order of challenge, as the acidic insulin and basic LMWP would automatically form tight aggregates through electrostatic interactions. In this paper, we developed an innovative conjugation strategy to solve this problem, by using succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-MAL) as an intermediate cross-linker during the coupling process. Both SDS-PAGE and MALDI-TOF mass spectroscopy confirmed the formation of a homogeneous, monomeric (1:1 ratio) insulin/LMWP conjugate without encountering the conventional problem of substrate aggregation. Cell culture studies demonstrated that transport of the Insulin-PEG-LMWP conjugate across the intestinal mucosal monolayer was augmented by almost five folds compared to native insulin. Furthermore, results from the in situ loop absorption tests in rats showed that systemic pharmacological bioavailability of insulin was significantly enhanced after its conjugation with LMWP. Overall, the presented chemical conjugation with LMWP could offer a reliable and safe means to improve the intestinal permeability of therapeutic peptides/proteins, shedding light of the possibility for their effective oral delivery. PMID:23863452

  7. Low molecular weight components of pollen alter bronchial epithelial barrier functions

    PubMed Central

    Blume, Cornelia; Swindle, Emily J; Gilles, Stefanie; Traidl-Hoffmann, Claudia; Davies, Donna E

    2015-01-01

    The bronchial epithelium plays a key role in providing a protective barrier against many environmental substances of anthropogenic or natural origin which enter the lungs during breathing. Appropriate responses to these agents are critical for regulation of tissue homeostasis, while inappropriate responses may contribute to disease pathogenesis. Here, we compared epithelial barrier responses to different pollen species, characterized the active pollen components and the signaling pathways leading to epithelial activation. Polarized bronchial cells were exposed to extracts of timothy grass (Phleum pratense), ragweed (Ambrosia artemisifolia), mugwort (Artemisia vulgaris), birch (Betula alba) and pine (Pinus sylvestris) pollens. All pollen species caused a decrease in ionic permeability as monitored trans-epithelial electrical resistance (TER) and induced polarized release of mediators analyzed by ELISA, with grass pollen showing the highest activity. Ultrafiltration showed that the responses were due to components <3kDa. However, lipid mediators, including phytoprostane E1, had no effect on TER, and caused only modest induction of mediator release. Reverse-phase chromatography separated 2 active fractions: the most hydrophilic maximally affected cytokine release whereas the other only affected TER. Inhibitor studies revealed that JNK played a more dominant role in regulation of barrier permeability in response to grass pollen exposure, whereas ERK and p38 controlled cytokine release. Adenosine and the flavonoid isorhamnetin present in grass pollen contributed to the overall effect on airway epithelial barrier responses. In conclusion, bronchial epithelial barrier functions are differentially affected by several low molecular weight components released by pollen. Furthermore, ionic permeability and innate cytokine production are differentially regulated. PMID:26451347

  8. Competitive adsorption of proteins and low-molecular-weight surfactants: computer simulation and microscopic imaging.

    PubMed

    Pugnaloni, Luis A; Dickinson, Eric; Ettelaie, Rammile; Mackie, Alan R; Wilde, Peter J

    2004-01-30

    Proteins and low-molecular-weight (LMW) surfactants are used in the food industry as emulsifying (and foaming) ingredients and as stabilizers. These attributes are related to their ability to adsorb at fluid-fluid (and gas-fluid) interfaces lowering the interfacial (and surface) tension of liquids. Hence, the study of the properties of adsorbed layers of these molecules can be expected to lead to a better understanding of their effect on food products. Direct proof of the validity of mesoscopic models of systems of proteins and LMW surfactants can only be achieved by quantitative theoretical predictions being tested against both macroscopic and mesoscopic experiments. Computer simulation constitutes one of the few available tools to predict mathematically the behaviour of models of realistic complexity. Furthermore, experimental techniques such as atomic force microscopy (AFM) now allow high resolution imaging of these systems, providing the mesoscopic scale measurements to compare with the simulations. In this review, we bring together a number of related findings that have been generated at this mesoscopic level over the past few years. A useful simple model consisting of spherical particles interacting via bonded and unbonded forces is described, and the derived computer simulation results are compared against those from the imaging experiments. Special attention is paid to the adsorption of binary mixtures of proteins, mixtures of LMW surfactants, and also protein+surfactant mixed systems. We believe that further development of these mathematically well-defined physical models is necessary in order to achieve a proper understanding of the key physico-chemical processes involved. PMID:14962406

  9. Low Molecular Weight Antagonists of Plasminogen Activator Inhibitor-1: Therapeutic Potential in Cardiovascular Disease.

    PubMed

    Simone, Tessa M; Higgins, Paul J

    2012-08-01

    Plasminogen activator inhibitor-1 (PAI-1; SERPINE1) is the major physiologic regulator of the plasmin-based pericellular proteolytic cascade, a modulator of vascular smooth muscle cell (VSMC) migration and a causative factor in cardiovascular disease and restenosis, particularly in the context of increased vessel transforming growth factor- β1 (TGF-β1) levels. PAI-1 limits conversion of plasminogen to plasmin (and, thereby, fibrin degradation) by inhibiting its protease targets urokinase and tissue-type plasminogen activators (uPA, tPA). PAI-1 also has signaling functions and binds to the low density lipoprotein receptor-related protein 1 (LRP1) to regulate LRP1-dependent cell motility that, in turn, contributes to neointima formation. PAI-1/uPA/uPA receptor/LRPI/integrin complexes are endocytosed with subsequent uPAR/LRP1/integrin redistribution to the leading edge, initiating an "adhesion-detachment-readhesion" cycle to promote cell migration. PAI-1 also interacts with LRP1 in a uPA/uPAR-independent manner triggering Jak/Stat1 pathway activation to stimulate cell motility. PAI-1 itself is a substrate for extracellular proteases and exists in a "cleaved" form which, while unable to interact with uPA and tPA, retains LRP1-binding and migratory activity. These findings suggest that there are multiple mechanisms through which inhibition of PAI-1 may promote cardiovascular health. Several studies have focused on the design, synthesis and preclinical assessment of PAI-1 antagonists including monoclonal antibodies, peptides and low molecular weight (LMW) antagonists. This review discusses the translational impact of LMW PAI-1 antagonists on cardiovascular disease addressing PAI-1-initiated signaling, PAI-1 structure, the design and characteristics of PAI-1-targeting drugs, results of in vitro and in vivo studies, and their clinical implications. PMID:23936868

  10. Anti-inflammatory activity of low molecular weight polysialic acid on human macrophages.

    PubMed

    Shahraz, Anahita; Kopatz, Jens; Mathy, Rene; Kappler, Joachim; Winter, Dominic; Kapoor, Shoba; Schütza, Vlad; Scheper, Thomas; Gieselmann, Volkmar; Neumann, Harald

    2015-01-01

    Oligosialic and polysialic acid (oligoSia and polySia) of the glycocalyx of neural and immune cells are linear chains, in which the sialic acid monomers are α2.8-glycosidically linked. Sialic acid-binding immunoglobulin-like lectin-11 (SIGLEC-11) is a primate-lineage specific receptor of human tissue macrophages and microglia that binds to α2.8-linked oligoSia. Here, we show that soluble low molecular weight polySia with an average degree of polymerization 20 (avDP20) interacts with SIGLEC-11 and acts anti-inflammatory on human THP1 macrophages involving the SIGLEC-11 receptor. Soluble polySia avDP20 inhibited the lipopolysaccharide (LPS)-induced gene transcription and protein expression of tumor necrosis factor-α (Tumor Necrosis Factor Superfamily Member 2, TNFSF2). In addition, polySia avDP20 neutralized the LPS-triggered increase in macrophage phagocytosis, but did not affect basal phagocytosis or endocytosis. Moreover, polySia avDP20 prevented the oxidative burst of human macrophages triggered by neural debris or fibrillary amyloid-β1-42. In a human macrophage-neuron co-culture system, polySia avDP20 also reduced loss of neurites triggered by fibrillary amyloid-β1-42. Thus, treatment with polySia avDP20 might be a new anti-inflammatory therapeutic strategy that also prevents the oxidative burst of macrophages. PMID:26582367