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Sample records for low-molecular-weight glutenin subunit

  1. 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...

  2. Genetic variability of the low-molecular-weight glutenin subunits in spelt wheat (Triticum aestivum ssp. spelta L. em Thell.).

    PubMed

    Caballero, L; Martín, L M; Alvarez, J B

    2004-03-01

    The low-molecular-weight glutenin subunit composition of a collection of 403 accessions of spelt wheat ( Triticum aestivum ssp. spelta L. em. Thell) was analyzed by SDS-PAGE. Extensive variation was found, including 46 different patterns for zone B and 16 for zone C. Patterns within zone B exhibited from two to six bands and patterns in zone C had between four and six bands in SDS-PAGE gels. A higher number of bands was observed when urea was added to the gels. Zone B exhibited between six and 11 bands, and we identified 14 new patterns in this zone. For zone C, up to ten new patterns that comprised between five and nine bands were detected. For both zones, 86 patterns were found. The variability detected in this material is greater than that detected in other hulled wheats.

  3. Comparative transcriptional and proteomic profiling of bread wheat cultivar and its derived transgenic line over-expressing a low molecular weight glutenin subunit gene in the endosperm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have carried out a parallel transcriptional and proteomic comparison of seeds from a transformed bread wheat line that over-expresses a transgenic low molecular weight glutenin subunit gene relative to the corresponding non-transformed genotype. Proteomic analyses showed that, during seed develop...

  4. Cloning and Characterization of Low-Molecular-Weight Glutenin Subunit Alleles from Chinese Wheat Landraces (Triticum aestivum L.)

    PubMed Central

    Zhao, Manli; Zhang, Xin; Yao, Guoliang; Sun, Genlou

    2014-01-01

    Low-molecular-weight glutenin subunits (LMW-GS) are of great importance in processing quality and participate in the formation of polymers in wheat. In this study, eight new LMW-GS alleles were isolated from Chinese wheat landraces (Triticum aestivum L.) and designated as Glu-A3-1a, Glu-A3-1b, Glu-B3-1a, Glu-B3-1b, Glu-B3-1c, Glu-D3-1a, Glu-D3-1b, and Glu-D3-1c, which were located at the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. Based on the proteins encoded, the number of deduced amino acids of Glu-B3 alleles was approximately 50 more than those of Glu-A3 and Glu-D3 alleles. The first cysteine of Glu-A3 and Glu-D3 alleles was located at the N-terminal domain, while that of Glu-B3 alleles was found in the repetitive domain, which may lead to the different functioning in forming disulfide bonds. All the eight genes were LMW-m types and the new allele of Glu-B3-1a which had nine cysteine residues may be the desirable LMW-GS gene for improving bread-making quality. PMID:24982945

  5. New insights into the organization, recombination, expression and functional mechanism of low molecular weight glutenin subunit genes in bread wheat.

    PubMed

    Dong, Lingli; Zhang, Xiaofei; Liu, Dongcheng; Fan, Huajie; Sun, Jiazhu; Zhang, Zhongjuan; Qin, Huanju; Li, Bin; Hao, Shanting; Li, Zhensheng; Wang, Daowen; Zhang, Aimin; Ling, Hong-Qing

    2010-01-01

    The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding. PMID:20975830

  6. New Insights into the Organization, Recombination, Expression and Functional Mechanism of Low Molecular Weight Glutenin Subunit Genes in Bread Wheat

    PubMed Central

    Fan, Huajie; Sun, Jiazhu; Zhang, Zhongjuan; Qin, Huanju; Li, Bin; Hao, Shanting; Li, Zhensheng; Wang, Daowen; Zhang, Aimin; Ling, Hong-Qing

    2010-01-01

    The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding. PMID:20975830

  7. Low molecular weight glutenin subunit gene Glu-B3h confers superior dough strength and breadmaking quality in wheat (Triticum aestivum L.)

    PubMed Central

    Wang, Yaping; Zhen, Shoumin; Luo, Nana; Han, Caixia; Lu, Xiaobing; Li, Xiaohui; Xia, Xianchun; He, Zhonghu; Yan, Yueming

    2016-01-01

    Low molecular weight glutenin subunit is one of the important quality elements in wheat (Triticum aestivum L.). Although considerable allelic variation has been identified, the functional properties of individual alleles at Glu-3 loci are less studied. In this work, we performed the first comprehensive study on the molecular characteristics and functional properties of the Glu-B3h gene using the wheat cultivar CB037B and its Glu-B3 deletion line CB037C. The results showed that the Glu-B3h deletion had no significant effects on plant morphological or yield traits, but resulted in a clear reduction in protein body number and size and main quality parameters, including inferior mixing property, dough strength, loaf volume, and score. Molecular characterization showed that the Glu-B3h gene consists of 1179 bp, and its encoded B-subunit has a longer repetitive domain and an increased number of α-helices, as well as higher expression, which could contribute to superior flour quality. The SNP-based allele-specific PCR markers designed for the Glu-B3h gene were developed and validated with bread wheat holding various alleles at Glu-B3 locus, which could effectively distinguish the Glu-B3h gene from others at the Glu-B3 locus, and have potential applications for wheat quality improvement through marker-assisted selection. PMID:27273251

  8. Characterization of B- and C-type low molecular weight glutenin subunits by electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry.

    PubMed

    Muccilli, Vera; Cunsolo, Vincenzo; Saletti, Rosaria; Foti, Salvatore; Masci, Stefania; Lafiandra, Domenico

    2005-02-01

    Low molecular weight glutenin subunits (LMW-GS) are typically subdivided into three groups, according to their molecular weights and isoelectric points, namely the B-, C-, and D groups. Enriched B- and C-type LMW-GS fractions extracted from the bread wheat cultivar Chinese Spring were characterized using high performance liquid chromatography (HPLC) directly interfaced with electrospray ionization mass spectrometry and HPLC coupled off-line with matrix-assisted laser desorption/ionization mass spectrometry, in order to ascertain the number and relative molecular masses of the components present in each fraction and determine the number of cysteine residues. About 70 components were detected in each of the fractions examined by the combined use of these two techniques, with 18 components common to both fractions. Analysis of the fractions after alkylation with 4-vinylpyridine allowed determination of the number of the cysteines present in about 40 subunits. The proteins detected were tentatively classified based on the relative molecular masses and number of cysteine residues. Cross-contamination was found in both B- and C- fractions, along with the presence of D-type LMW-GS. The two fractions also contained unexpected components, probably lipid transfer proteins and omega-gliadins. The presence of extensive microheterogeneity was suggested by the detection of several co-eluting proteins with minor differences in their molecular masses.

  9. An asparagines residue at the N-terminus affects the maturation process of low molecular weight glutenin subunits of wheat endosperm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat (Triticum spp.) glutenin polymers are of two main types, high- (HMW-GS) and low- (LMW-GS) molecular weight subunits. The most common are the latter, based on the first amino acid of the mature sequence, are known as LMW-m and LMW-s types. They differ as a result of three extra amino acids (MET...

  10. Comparison of low molecular weight glutenin subunits identified by SDS-PAGE, 2-DE, MALDI-TOF-MS and PCR in common wheat

    PubMed Central

    2010-01-01

    Background Low-molecular-weight glutenin subunits (LMW-GS) play a crucial role in determining end-use quality of common wheat by influencing the viscoelastic properties of dough. Four different methods - sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional gel electrophoresis (2-DE, IEF × SDS-PAGE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and polymerase chain reaction (PCR), were used to characterize the LMW-GS composition in 103 cultivars from 12 countries. Results At the Glu-A3 locus, all seven alleles could be reliably identified by 2-DE and PCR. However, the alleles Glu-A3e and Glu-A3d could not be routinely distinguished from Glu-A3f and Glu-A3g, respectively, based on SDS-PAGE, and the allele Glu-A3a could not be differentiated from Glu-A3c by MALDI-TOF-MS. At the Glu-B3 locus, alleles Glu-B3a, Glu-B3b, Glu-B3c, Glu-B3g, Glu-B3h and Glu-B3j could be clearly identified by all four methods, whereas Glu-B3ab, Glu-B3ac, Glu-B3ad could only be identified by the 2-DE method. At the Glu-D3 locus, allelic identification was problematic for the electrophoresis based methods and PCR. MALDI-TOF-MS has the potential to reliably identify the Glu-D3 alleles. Conclusions PCR is the simplest, most accurate, lowest cost, and therefore recommended method for identification of Glu-A3 and Glu-B3 alleles in breeding programs. A combination of methods was required to identify certain alleles, and would be especially useful when characterizing new alleles. A standard set of 30 cultivars for use in future studies was chosen to represent all LMW-GS allelic variants in the collection. Among them, Chinese Spring, Opata 85, Seri 82 and Pavon 76 were recommended as a core set for use in SDS-PAGE gels. Glu-D3c and Glu-D3e are the same allele. Two new alleles, namely, Glu-D3m in cultivar Darius, and Glu-D3n in Fengmai 27, were identified by 2-DE. Utilization of the suggested standard cultivar set, seed of

  11. Composition and functional analysis of low-molecular-weight glutenin alleles with Aroona near-isogenic lines of bread wheat

    PubMed Central

    2012-01-01

    Background Low-molecular-weight glutenin subunits (LMW-GS) strongly influence the bread-making quality of bread wheat. These proteins are encoded by a multi-gene family located at the Glu-A3, Glu-B3 and Glu-D3 loci on the short arms of homoeologous group 1 chromosomes, and show high allelic variation. To characterize the genetic and protein compositions of LMW-GS alleles, we investigated 16 Aroona near-isogenic lines (NILs) using SDS-PAGE, 2D-PAGE and the LMW-GS gene marker system. Moreover, the composition of glutenin macro-polymers, dough properties and pan bread quality parameters were determined for functional analysis of LMW-GS alleles in the NILs. Results Using the LMW-GS gene marker system, 14–20 LMW-GS genes were identified in individual NILs. At the Glu-A3 locus, two m-type and 2–4 i-type genes were identified and their allelic variants showed high polymorphisms in length and nucleotide sequences. The Glu-A3d allele possessed three active genes, the highest number among Glu-A3 alleles. At the Glu-B3 locus, 2–3 m-type and 1–3 s-type genes were identified from individual NILs. Based on the different compositions of s-type genes, Glu-B3 alleles were divided into two groups, one containing Glu-B3a, B3b, B3f and B3g, and the other comprising Glu-B3c, B3d, B3h and B3i. Eight conserved genes were identified among Glu-D3 alleles, except for Glu-D3f. The protein products of the unique active genes in each NIL were detected using protein electrophoresis. Among Glu-3 alleles, the Glu-A3e genotype without i-type LMW-GS performed worst in almost all quality properties. Glu-B3b, B3g and B3i showed better quality parameters than the other Glu-B3 alleles, whereas the Glu-B3c allele containing s-type genes with low expression levels had an inferior effect on bread-making quality. Due to the conserved genes at Glu-D3 locus, Glu-D3 alleles showed no significant differences in effects on all quality parameters. Conclusions This work provided new insights into the

  12. Effect of low molecular weight aliphatic alcohols and related compounds on platelet factor 4 subunit association.

    PubMed

    Yang, Y; Barker, S; Chen, M J; Mayo, K H

    1993-05-01

    Titration of platelet factor 4 (PF4) with increasing concentrations of various low molecular weight aliphatic alcohols disrupts dimer and tetramer quaternary structure while preserving tertiary structural integrity. Normally observed slow subunit exchange (1H NMR time scale) is shifted into the fast chemical exchange regime. The order of effectiveness is butanol > 2-propanol > propanol > ethanol > methanol. Fluorination of ethanol (trifluoroethanol) and 2-propanol (hexafluoro-2-propanol) increases effectiveness by approximately 2 orders of magnitude. Oxidation to 2-propanone or trifluoro-2-propanone produces a less effective compound, suggesting a mechanistic role for the hydroxyl group. Increasing the number of hydroxyls to three, as in glycerol, however, is relatively ineffective in disrupting aggregate states or modifying subunit exchange rates. While 19F NMR studies indicate that these alcohols specifically interact with PF4, binding alone can not explain their mechanism of action. Dimethyl sulfoxide, structurally similar to 2-propanol, disrupts PF4 aggregation by direct binding, but does not shift subunit exchange kinetics into the NMR fast-exchange regime. Although not fully understood, the effectiveness of these compounds appears to be related to the colligative properties of the solution.

  13. Identification of Low Molecular Weight Glutenin Alleles by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) in Common Wheat (Triticum aestivum L.).

    PubMed

    Wang, Aili; Liu, Li; Peng, Yanchun; Islam, Shahidul; Applebee, Marie; Appels, Rudi; Yan, Yueming; Ma, Wujun

    2015-01-01

    Low molecular weight glutenin subunits (LMW-GS) play an important role in determining dough properties and breadmaking quality. However, resolution of the currently used methodologies for analyzing LMW-GS is rather low which prevents an efficient use of genetic variations associated with these alleles in wheat breeding. The aim of the current study is to evaluate and develop a rapid, simple, and accurate method to differentiate LMW-GS alleles using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A set of standard single LMW-GS allele lines as well as a suite of well documented wheat cultivars were collected from France, CIMMYT, and Canada. Method development and optimization were focused on protein extraction procedures and MALDI-TOF instrument settings to generate reproducible diagnostic spectrum peak profiles for each of the known wheat LMW-GS allele. Results revealed a total of 48 unique allele combinations among the studied genotypes. Characteristic MALDI-TOF peak patterns were obtained for 17 common LMW-GS alleles, including 5 (b, a or c, d, e, f), 7 (a, b, c, d or i, f, g, h) and 5 (a, b, c, d, f) patterns or alleles for the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. In addition, some reproducible MALDI-TOF peak patterns were also obtained that did not match with any known alleles. The results demonstrated a high resolution and throughput nature of MALDI-TOF technology in analyzing LMW-GS alleles, which is suitable for application in wheat breeding programs in processing a large number of wheat lines with high accuracy in limited time. It also suggested that the variation of LMW-GS alleles is more abundant than what has been defined by the current nomenclature system that is mainly based on SDS-PAGE system. The MALDI-TOF technology is useful to differentiate these variations. An international joint effort may be needed to assign allele symbols to these newly identified alleles and determine their effects on end

  14. Identification of Low Molecular Weight Glutenin Alleles by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) in Common Wheat (Triticum aestivum L.)

    PubMed Central

    Islam, Shahidul; Applebee, Marie; Appels, Rudi; Yan, Yueming; Ma, Wujun

    2015-01-01

    Low molecular weight glutenin subunits (LMW-GS) play an important role in determining dough properties and breadmaking quality. However, resolution of the currently used methodologies for analyzing LMW-GS is rather low which prevents an efficient use of genetic variations associated with these alleles in wheat breeding. The aim of the current study is to evaluate and develop a rapid, simple, and accurate method to differentiate LMW-GS alleles using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A set of standard single LMW-GS allele lines as well as a suite of well documented wheat cultivars were collected from France, CIMMYT, and Canada. Method development and optimization were focused on protein extraction procedures and MALDI-TOF instrument settings to generate reproducible diagnostic spectrum peak profiles for each of the known wheat LMW-GS allele. Results revealed a total of 48 unique allele combinations among the studied genotypes. Characteristic MALDI-TOF peak patterns were obtained for 17 common LMW-GS alleles, including 5 (b, a or c, d, e, f), 7 (a, b, c, d or i, f, g, h) and 5 (a, b, c, d, f) patterns or alleles for the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. In addition, some reproducible MALDI-TOF peak patterns were also obtained that did not match with any known alleles. The results demonstrated a high resolution and throughput nature of MALDI-TOF technology in analyzing LMW-GS alleles, which is suitable for application in wheat breeding programs in processing a large number of wheat lines with high accuracy in limited time. It also suggested that the variation of LMW-GS alleles is more abundant than what has been defined by the current nomenclature system that is mainly based on SDS-PAGE system. The MALDI-TOF technology is useful to differentiate these variations. An international joint effort may be needed to assign allele symbols to these newly identified alleles and determine their effects on end

  15. Wheat gluten: high molecular weight glutenin subunits--structure, genetics, and relation to dough elasticity.

    PubMed

    Anjum, Faqir Muhammad; Khan, Moazzam Rafiq; Din, Ahmad; Saeed, Muhammad; Pasha, Imran; Arshad, Muhammad Umair

    2007-04-01

    Gluten proteins, representing the major protein fraction of the starchy endosperm, are predominantly responsible for the unique position of wheat amongst cereals. These form a continuous proteinaceous matrix in the cells of the mature dry grain and form a continuous viscoelastic network during the mixing process of dough development. These viscoelastic properties underline the utilization of wheat to prepare bread and other wheat flour based foodstuffs. One group of gluten proteins is glutenin, which consists of high molecular weight (HMW) and low molecular weight (LMW) subunits. The HMW glutenin subunits (HMW-GS) are particularly important for determining dough elasticity. The common wheat possesses 3 to 5 HMW subunits encoded at the Glu-1 loci on the long arms of group 1 chromosomes (1A, 1B, and 1D). The presence of certain HMW subunits is positively correlated with good bread-making quality. Glutamine-rich repetitive sequences that comprise the central part of the HMW subunits are actually responsible for the elastic properties due to extensive arrays of interchain hydrogen bonds. Genetic engineering can be used to manipulate the amount and composition of the HMW subunits, leading to either increased dough strength or more drastic changes in gluten structure and properties.

  16. Synthesis of gluten-forming polypeptides. 1. Biosynthesis of gliadins and glutenin subunits.

    PubMed

    Abonyi, Tibor; Király, István; Tömösközi, Sándor; Baticz, Orsolya; Guóth, Adrienn; Gergely, Szilveszter; Scholz, Eva; Lásztity, Demeter; Lásztity, Radomir

    2007-05-01

    Five winter wheat cultivars--GK Othalom (HMW-GS composition 2*, 7+8, 5+10), Ukrainka (1, 7+8, 5+10), Palotás (2*, 7+9, 5+10), Ködmön (2*, 7+8, 5+10), and Csongrád (2*, 7+9, 2+12)--grown in Hungary and harvested in the year 2005 were studied. The biosynthesis of gluten-forming polypeptides was followed starting at the 12th day after anthesis to the 53rd. Fresh kernel weight, moisture, and dry matter content of fresh kernels and gliadin and glutenin contents were determined. Gliadin components, total amounts of HMW and LMW polypeptides, and individual HMW polypeptides were determined using a RP-HPLC technique. Although considerable quantitative differences were observed concerning the content of total protein, gliadin, glutenin, and individual gluten-forming polypeptides, the character of accumulation of protein components--determined on the basis protein mass/kernel--was the same for the all of the cultivars studied and could be presented by a sigmoid curve. Small quantities of the gliadin and glutenin monomers may be detected in early stages of kernel development, but the bulk of these proteins is synthesized in later stages of development. It is generally suggested by specialists that the formation and accumulation of glutenin polymers starts later than the synthesis of monomers. Experimental data presented in this paper confirm this suggestion and show that in the first phase of protein synthesis the monomers are in "free" form; polymeric glutenin is detected only later. HMW glutenin subunits are synthesized synchronously, and quantitatively the polypeptides coded by chromosomes D and B dominate.

  17. Low-molecular-weight heparins and angiogenesis.

    PubMed

    Norrby, Klas

    2006-02-01

    The involvement of the vascular system in malignancy encompasses not only angiogenesis, but also systemic hypercoagulability and a pro-thrombotic state, and there is increasing evidence that pathways of blood coagulation and angiogenesis are reciprocally linked. In fact, cancer atients often display hypercoagulability resulting in markedly increased thromboembolism, which requires anti-coagulant treatment using heparins, for example. Clinical trials reveal that treatment with various low-molecular-weight heparins (LMWHs) improves the survival time in cancer patients receiving chemotherapy compared with those receiving unfractionated standard heparin (UFH) or no heparin treatment, as well as in cancer patients receiving LMWH as thrombosis prophylaxis during primary surgery. This anti-tumor effect of the heparins appears to be unrelated to their anti-coagulant activity, but the mechanisms involved are not fully understood. Tumor growth and spread are dependent on angiogenesis and it is noteworthy that the most potent endogenous pro- and anti-angiogenic factors are heparin-binding proteins that may be affected by systemic treatment with heparins. Heparin and other glycosaminoglycans play a role in vascular endothelial cell function, as they are able to modulate the activities of angiogenic growth factors by facilitating the interaction with their receptor and promoting receptor activation. To date, preclinical studies have demonstrated that only LMWH fragments produced by the heparinase digestion of UFH, i.e. tinzaparin, exert anti-angiogenic effects in any type of tissue in vivo. These effects are fragment-mass-specific and angiogenesis-type-specific. Data on the effect of various LMWHs and UFH on endothelial cell capillary tube formation and proliferation in vitro are also presented. We hope that this paper will stimulate and facilitate future research designed to elucidate whether the anti-angiogenic or anti-tumor effects of commercial LMWHs in their own right are

  18. Identification and Characterization of High-Molecular-Weight Glutenin Subunits from Agropyron intermedium

    PubMed Central

    Cao, Shuanghe; Li, Zhixin; Gong, Caiyan; Xu, Hong; Yang, Ran; Hao, Shanting; Wang, Xianping; Wang, Daowen; Zhang, Xiangqi

    2014-01-01

    High-molecular-weight glutenin subunit (HMW-GS) is a primary determinant of processing quality of wheat. Considerable progress has been made in understanding the structure, function and genetic regulation of HMW-GS in wheat and some of its related species, but less is known about their orthologs in Agropyron intermedium, a useful related species for wheat improvement. Here seven HMW-GSs in Ag. intermedium were identified using SDS-PAGE and Western blotting experiments. Subsequently, the seven genes (Glu-1Aix1∼4 and Glu-1Aiy1∼3) encoding the seven HMW-GSs were isolated using PCR technique with degenerate primers, and confirmed by bacterial expression and Western blotting. Sequence analysis indicated that the seven Ag. intermedium HMW-GSs shared high similarity in primary structure to those of wheat, but four of the seven subunits were unusually small compared to the representatives of HMW-GS from wheat and two of them possessed extra cysteine residues. The alignment and clustering analysis of deduced amino acid sequences revealed that 1Aix1 and 1Aiy1 subunits had special molecular structure, belonging to the hybrid type compounding between typical x- and y-type subunit. The xy-type subunit 1Aix1 is composed of the N-terminal of x-type and C-terminal of y-type, whereas yx-type subunit 1Aiy1 comprises the N-terminal of y-type and C-terminal of x-type. This result strongly supported the hypothesis of unequal crossover mechanism that might generate the novel coding sequence for the hybrid type of HMW-GSs. In addition to the aforementioned, the other novel characteristics of the seven subunits were also discussed. Finally, phylogenetic analysis based on HMW-GS genes was carried out and provided new insights into the evolutionary biology of Ag. intermedium. PMID:24503781

  19. Identification and characterization of high-molecular-weight glutenin subunits from Agropyron intermedium.

    PubMed

    Cao, Shuanghe; Li, Zhixin; Gong, Caiyan; Xu, Hong; Yang, Ran; Hao, Shanting; Wang, Xianping; Wang, Daowen; Zhang, Xiangqi

    2014-01-01

    High-molecular-weight glutenin subunit (HMW-GS) is a primary determinant of processing quality of wheat. Considerable progress has been made in understanding the structure, function and genetic regulation of HMW-GS in wheat and some of its related species, but less is known about their orthologs in Agropyron intermedium, a useful related species for wheat improvement. Here seven HMW-GSs in Ag. intermedium were identified using SDS-PAGE and Western blotting experiments. Subsequently, the seven genes (Glu-1Aix1 ∼ 4 and Glu-1Aiy1 ∼ 3) encoding the seven HMW-GSs were isolated using PCR technique with degenerate primers, and confirmed by bacterial expression and Western blotting. Sequence analysis indicated that the seven Ag. intermedium HMW-GSs shared high similarity in primary structure to those of wheat, but four of the seven subunits were unusually small compared to the representatives of HMW-GS from wheat and two of them possessed extra cysteine residues. The alignment and clustering analysis of deduced amino acid sequences revealed that 1Aix1 and 1Aiy1 subunits had special molecular structure, belonging to the hybrid type compounding between typical x- and y-type subunit. The xy-type subunit 1Aix1 is composed of the N-terminal of x-type and C-terminal of y-type, whereas yx-type subunit 1Aiy1 comprises the N-terminal of y-type and C-terminal of x-type. This result strongly supported the hypothesis of unequal crossover mechanism that might generate the novel coding sequence for the hybrid type of HMW-GSs. In addition to the aforementioned, the other novel characteristics of the seven subunits were also discussed. Finally, phylogenetic analysis based on HMW-GS genes was carried out and provided new insights into the evolutionary biology of Ag. intermedium. PMID:24503781

  20. Low molecular weight heparin in prevention of perioperative thrombosis.

    PubMed Central

    Leizorovicz, A.; Haugh, M. C.; Chapuis, F. R.; Samama, M. M.; Boissel, J. P.

    1992-01-01

    OBJECTIVE--To determine whether prophylactic treatment with low molecular weight heparin reduces the incidence of thrombosis in patients who have had general or orthopaedic surgery. DESIGN--Meta-analysis of results from 52 randomised, controlled clinical studies (29 in general surgery and 23 in orthopaedic surgery) in which low molecular weight heparin was compared with placebo, dextran, or unfractionated heparin. SUBJECTS--Patients who had had general or orthopaedic surgery. INTERVENTION--Once daily injection of a low molecular weight heparin compared with placebo, dextran, or unfractionated heparin. MAIN OUTCOME MEASURES--Incidence of deep venous thrombosis, pulmonary embolism, major haemorrhages, and death. RESULTS--The results confirm that low molecular weight heparins are more efficacious for the prophylactic treatment of deep venous thrombosis than placebo (common odds ratio 0.31, 95% confidence interval 0.22 to 0.43; p < 0.001) and dextran (0.44, 0.30 to 0.65; p < 0.001). The results suggest that low molecular weight heparins are also more efficacious than unfractionated heparin (0.85, 0.74 to 0.97; p = 0.02), with no significant difference in the incidence of major haemorrhages (1.06, 0.93 to 1.20; p = 0.62). CONCLUSIONS--Low molecular weight heparins seem to have a higher benefit to risk ratio than unfractionated heparin in preventing perioperative thrombosis. However, it remains to be shown in a suitably powered clinical trial whether low molecular weight heparin reduces the risk of fatal pulmonary embolism compared with heparin. PMID:1281030

  1. 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.

  2. Quality trait variations in [⁶⁰Co]-irradiated wheat and high-molecular-weight glutenin subunit mutant identification.

    PubMed

    Lai, D-E; Wang, M; Zhang, C-Y

    2014-10-31

    With 300 Gy of [(60)Co] γ-ray radiation of dry wheat seeds of Vortex 9722, the protein content, wet gluten content, sedimentation value, and hardness variation were analyzed in 341 lines in M4. Using over population mean ± 2X standard deviation as the screening standard, 8 lines with higher protein and wet gluten content and 4 lines with lower protein and wet gluten content were selected. In the M5 generation, the quality traits - silty parameters and high molecular weight glutenin subunits (HMW-GS) - were further analyzed in these 12 lines. The results showed that in the M5 generation, the quality traits in some variants were significantly different from those in the parents; the farinograms varied greatly. Eleven variants had significantly different HMW-GS bands compared to their parents. The parents had a HMW-GS composition of 5 + 14 + 15 + 12 + 9, and the variants had HMW-GS of 11 + 5 + 7 + 9 + 12 subunits or 1 + 5 + 7 + 8 + 12 subunits, indicating that the glutenin loci of these lines were mutated.

  3. Molecular Mechanisms of HMW Glutenin Subunits from 1Sl Genome of Aegilops longissima Positively Affecting Wheat Breadmaking Quality

    PubMed Central

    Li, Ning; Li, Xiaohui; Ma, Wujun; Weißgerber, H.; Zeller, Friedrich; Hsam, Sai; Yan, Yueming

    2013-01-01

    A wheat cultivar “Chinese Spring” chromosome substitution line CS-1Sl(1B), in which the 1B chromosome was substituted by 1Sl from Aegilops longissima, was developed and found to possess superior dough and breadmaking quality. The molecular mechanism of its super quality conformation is studied in the aspects of high molecular glutenin genes, protein accumulation patterns, glutenin polymeric proteins, protein bodies, starch granules, and protein disulfide isomerase (PDI) and PDI-like protein expressions. Results showed that the introduced HMW-GS 1Sl×2.3* and 1Sly16* in the substitution line possesses long repetitive domain, making both be larger than any known x- and y-type subunits from B genome. The introduced subunit genes were also found to have a higher level of mRNA expressions during grain development, resulting in more HMW-GS accumulation in the mature grains. A higher abundance of PDI and PDI-like proteins was observed which possess a known function of assisting disulfide bond formation. Larger HMW-GS deposited in protein bodies were also found in the substitution line. The CS substitution line is expected to be highly valuable in wheat quality improvement since the novel HMW-GS are located on chromosome 1Sl, making it possible to combine with the known superior D×5+Dy10 subunits encoded by Glu-D1 for developing high quality bread wheat. PMID:23593125

  4. 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

  5. Low-molecular-weight heparins: differential characterization/physical characterization.

    PubMed

    Guerrini, Marco; Bisio, Antonella

    2012-01-01

    Low-molecular-weight heparins (LMWHs), derived from unfractionated heparin (UFH) through different depolymerization processes, have advantages with respect to the parent heparin in terms of pharmacokinetics, convenience of administration, and reduced side effects. Each LMWH can be considered as an independent drug with its own activity profile, placing significance on their biophysical characterization, which will also enable a better understanding of their structure-function relationship. Several chemical and physical methods, some involving sample modification, are now available and are reviewed.

  6. Structural Characterization and Evolutionary Relationship of High-Molecular-Weight Glutenin Subunit Genes in Roegneria nakaii and Roegneria alashanica

    PubMed Central

    Zhang, Lujun; Li, Zhixin; Fan, Renchun; Wei, Bo; Zhang, Xiangqi

    2016-01-01

    The Roegneria of Triticeae is a large genus including about 130 allopolyploid species. Little is known about its high-molecular-weight glutenin subunits (HMW-GSs). Here, we reported six novel HMW-GS genes from R. nakaii and R. alashanica. Sequencing indicated that Rny1, Rny3, and Ray1 possessed intact open reading frames (ORFs), whereas Rny2, Rny4, and Ray2 harbored in-frame stop codons. All of the six genes possessed a similar primary structure to known HMW-GS, while showing some unique characteristics. Their coding regions were significantly shorter than Glu-1 genes in wheat. The amino acid sequences revealed that all of the six genes were intermediate towards the y-type. The phylogenetic analysis showed that the HMW-GSs from species with St, StY, or StH genome(s) clustered in an independent clade, varying from the typical x- and y-type clusters. Thus, the Glu-1 locus in R. nakaii and R. alashanica is a very primitive glutenin locus across evolution. The six genes were phylogenetically split into two groups clustered to different clades, respectively, each of the two clades included the HMW-GSs from species with St (diploid and tetraploid species), StY, and StH genomes. Hence, it is concluded that the six Roegneria HMW-GS genes are from two St genomes undergoing slight differentiation. PMID:27447615

  7. Proteogenomic Characterization of Novel x-Type High Molecular Weight Glutenin Subunit 1Ax1.1

    PubMed Central

    Ribeiro, Miguel; Bancel, Emmanuelle; Faye, Annie; Dardevet, Mireille; Ravel, Catherine; Branlard, Gérard; Igrejas, Gilberto

    2013-01-01

    Analysis of Portuguese wheat (Triticum aestivum L.) landrace ‘Barbela’ revealed the existence of a new x-type high molecular weight-glutenin subunit (HMW-GS) encoded at the Glu-A1 locus, which we named 1Ax1.1. Using one-dimensional and two-dimensional electrophoresis and mass spectrometry, we compared subunit 1Ax1.1 with other subunits encoded at the Glu-A1 locus. Subunit 1Ax1.1 has a theoretical molecular weight of 93,648 Da (or 91,508 Da for the mature protein) and an isoelectric point (pI) of about 5.7, making it the largest and most acidic HMW-GS known to be encoded at Glu-A1. Specific primers were designed to amplify and sequence 2601 bp of the Glu-A1 locus from the ‘Barbela 28’ wheat genome. A very high level of identity was found between the sequence encoding 1Ax1.1 and those encoding other alleles of the locus. The major difference found was an insertion of 36 amino acids in the central repetitive domain. PMID:23478438

  8. Characterization of durum wheat high molecular weight glutenin subunits Bx20 and By20 sequences by a molecular and proteomic approach.

    PubMed

    Santagati, Vito Davide; Sestili, Francesco; Lafiandra, Domenico; D'Ovidio, Renato; Rogniaux, Helene; Masci, Stefania

    2016-07-01

    Wheat high molecular weight glutenin subunit variation is important because of its great influence on glutenin polymer structure, that is related to dough technological properties. Among the different subunits, the pair Bx20 and By20 is known to have a negative effect on quality, but the reasons are not clear: Bx20 has two cysteines, which theoretically make this subunit a chain extender of the glutenin polymer, just like the other Bx subunits, showing four cysteines, two of which should be involved in intra-molecular disulfide bonds. By20 has never been characterized so far at molecular level. Here we report the nucleotide sequences of Bx20 and By20 genes isolated from the durum wheat cultivar 'Lira 45' and the validation of the corresponding deduced amino acid sequences by using MALDI-TOF and LC-MS/MS. Four nucleotide differences were identified in the Bx20 gene with respect to the deduced sequence present in NCBI, causing two amino acid substitutions. For the By20 subunit, nucleotide and amino acid sequences revealed a great similarity to By15, both at gene and protein levels, showing five nucleotide changes generating two amino acid differences. No evidence of post-translational modifications has been found. Hypotheses are formulated in regard to relationships with technological quality. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Characteristics of modern triticale quality: glutenin and secalin subunit composition and mixograph properties.

    PubMed

    Pattison, Angela L; Appelbee, Marie; Trethowan, Richard M

    2014-05-28

    Triticale is a hardy, high yielding cereal crop with a reputation for poor gluten strength. The secalogluten formation capacity was investigated in 17 modern triticale cultivars by defining their HMW glutenin and 75K γ-secalin alleles and then assessing SDS-sedimentation height and mixograph parameters in a subset of cultivars. The allelic diversity was poor with only 13 alleles identified at four loci; nevertheless, sufficient variability existed to allow secalogluten improvement through crossbreeding and selection. SDS-sedimentation height of triticale (35.5 mm) and mixing time (2.7 min) was equivalent to soft wheat but significantly less than hard wheat. However, flour protein content was 16% less in triticale compared to wheat, despite similar grain protein contents, suggesting triticale stores a lower proportion of grain protein in the endosperm. The confounding factor of protein content must be considered as part of an equitable analysis of gluten quality in cultivar breeding, in the interpretation of previous triticale research, and when comparing triticale to wheat. Improved glutenin properties will expand the utility of triticale in human food products and, thus, increase potential profitability. PMID:24792750

  10. Characteristics of modern triticale quality: glutenin and secalin subunit composition and mixograph properties.

    PubMed

    Pattison, Angela L; Appelbee, Marie; Trethowan, Richard M

    2014-05-28

    Triticale is a hardy, high yielding cereal crop with a reputation for poor gluten strength. The secalogluten formation capacity was investigated in 17 modern triticale cultivars by defining their HMW glutenin and 75K γ-secalin alleles and then assessing SDS-sedimentation height and mixograph parameters in a subset of cultivars. The allelic diversity was poor with only 13 alleles identified at four loci; nevertheless, sufficient variability existed to allow secalogluten improvement through crossbreeding and selection. SDS-sedimentation height of triticale (35.5 mm) and mixing time (2.7 min) was equivalent to soft wheat but significantly less than hard wheat. However, flour protein content was 16% less in triticale compared to wheat, despite similar grain protein contents, suggesting triticale stores a lower proportion of grain protein in the endosperm. The confounding factor of protein content must be considered as part of an equitable analysis of gluten quality in cultivar breeding, in the interpretation of previous triticale research, and when comparing triticale to wheat. Improved glutenin properties will expand the utility of triticale in human food products and, thus, increase potential profitability.

  11. Low molecular weight Abeta induces collapse of endoplasmic reticulum.

    PubMed

    Lai, Cora Sau-Wan; Preisler, Julie; Baum, Larry; Lee, Daniel Hong-Seng; Ng, Ho-Keung; Hugon, Jacques; So, Kwok-Fai; Chang, Raymond Chuen-Chung

    2009-05-01

    The endoplasmic reticulum (ER) is a dynamic multifunction organelle that is responsible for Ca(2+) homeostasis, protein folding, post-translational modification, protein degradation, and transportation of nascent proteins. Disruption of ER architecture might affect the normal physiology of the cell. In yeast, expansion of the ER is observed under unfolded protein response (UPR) and subsequently induces autophagy initiated from the ER. Here, we found that soluble low molecular weight of Abeta disrupted the anchoring between ER and microtubules (MT) and induced collapse of ER. In addition, it decreased the stability of MT. Subsequently, low molecular weight Abeta triggered autophagy and enhanced lysosomal degradation, as shown by electron microscopy and live-cell imaging. Dysfunction of ER can be further proved in postmortem AD brain and transgenic mice bearing APP Swedish mutation by immunohistochemical analysis of calreticulin. Treatment with Taxol, a MT-stabilizing agent, could partially inhibit collapse of the ER and induction of autophagy. The results show that Abeta-induced disruption of MT can affect the architecture of the ER. Collapse/aggregation of the ER may play an important role in Abeta peptide-triggered neurodegenerative processes.

  12. The wheat transcription factor TaGAMyb recruits histone acetyltransferase and activates the expression of a high-molecular-weight glutenin subunit gene.

    PubMed

    Guo, Weiwei; Yang, Hua; Liu, Yongqiang; Gao, Yujiao; Ni, Zhongfu; Peng, Huiru; Xin, Mingming; Hu, Zhaorong; Sun, Qixin; Yao, Yingyin

    2015-10-01

    Glutenin proteins in wheat (Triticum aestivum L.) flour confer unique viscoelastic properties to dough products and, therefore, the concentration and composition of the glutenin proteins determine its end-use value. However, the mechanisms governing the glutenin gene expression remain elusive. In this study, we report that wheat TaGAMyb activates the high-molecular-weight glutenin subunit genes (TaGLU) through recruiting the histone acetyltransferase GCN5. By sequencing the promoters of TaGLU-1 genes from 40 modern wheat cultivars, we identified eight types of TaGAMyb binding motifs and verified these by electrophoretic mobility shift assays. The number of TaGAMyb binding motifs in TaGLU-1 genes is correlated with the abundance of glutenin in different cultivars. Chromatin immunoprecipitation plus polymerase chain reaction (ChIP-PCR) analysis reveals that TaGCN5 directly targets the promoters of TaGLU-1 genes in wheat endosperm. We find that TaGAMyb physically interacts with the wheat histone acetyltransferase TaGCN5 and also interacts with Arabidopsis thaliana AtGCN5. TaGAMyb ectopically expressed in Arabidopsis binds to the TaGLU-1Dy promoter on a TaGLU-1Dy transgene and activates its expression. AtGCN5 also targets the TaGLU-1Dy transgene and is involved in the establishment of acetylation at H3K9 and H3K14. These results demonstrate that TaGAMyb plays a dual role in activating expression of glutenin gene by directly binding to the TaGLU promoter and by recruiting GCN5 to modulate histone acetylation during wheat endosperm development.

  13. Conserved cis-regulatory modules in promoters of genes encoding wheat high-molecular-weight glutenin subunits

    PubMed Central

    Ravel, Catherine; Fiquet, Samuel; Boudet, Julie; Dardevet, Mireille; Vincent, Jonathan; Merlino, Marielle; Michard, Robin; Martre, Pierre

    2014-01-01

    The concentration and composition of the gliadin and glutenin seed storage proteins (SSPs) in wheat flour are the most important determinants of its end-use value. In cereals, the synthesis of SSPs is predominantly regulated at the transcriptional level by a complex network involving at least five cis-elements in gene promoters. The high-molecular-weight glutenin subunits (HMW-GS) are encoded by two tightly linked genes located on the long arms of group 1 chromosomes. Here, we sequenced and annotated the HMW-GS gene promoters of 22 electrophoretic wheat alleles to identify putative cis-regulatory motifs. We focused on 24 motifs known to be involved in SSP gene regulation. Most of them were identified in at least one HMW-GS gene promoter sequence. A common regulatory framework was observed in all the HMW-GS gene promoters, as they shared conserved cis-regulatory modules (CCRMs) including all the five motifs known to regulate the transcription of SSP genes. This common regulatory framework comprises a composite box made of the GATA motifs and GCN4-like Motifs (GLMs) and was shown to be functional as the GLMs are able to bind a bZIP transcriptional factor SPA (Storage Protein Activator). In addition to this regulatory framework, each HMW-GS gene promoter had additional motifs organized differently. The promoters of most highly expressed x-type HMW-GS genes contain an additional box predicted to bind R2R3-MYB transcriptional factors. However, the differences in annotation between promoter alleles could not be related to their level of expression. In summary, we identified a common modular organization of HMW-GS gene promoters but the lack of correlation between the cis-motifs of each HMW-GS gene promoter and their level of expression suggests that other cis-elements or other mechanisms regulate HMW-GS gene expression. PMID:25429295

  14. Polymerization of wheat gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread.

    PubMed

    Wang, Xiang-Yu; Guo, Xiao-Na; Zhu, Ke-Xue

    2016-06-15

    Polymerization of gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread (CSB) were investigated, providing a theoretical basis to improve and regulate the quality of CSB. Protein extractability and free sulfhydryl (SH) contents increased to some degree during the dough preparation stage, but significantly (P<0.05) decreased during steaming. Remarkable protein aggregates were observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns. The microstructure study of the gas cell and the protein network by confocal laser scanning microscopy (CLSM) further revealed the formation of a continuous and three-dimensional gluten network. The loss and recovery of GMP wet weight during dough processing were significant (P<0.05). Glutenin depolymerization negatively correlated with GMP wet weight and the contents of high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS). Gluten polymerization led to a decrease in G' and G″ of GMP while gluten depolymerization induced a slight recovery in G' and G″ of GMP.

  15. Characterization of a new wheat-Aegilops biuncialis addition line conferring quality-associated HMW glutenin subunits.

    PubMed

    Zhou, J P; Yao, C H; Yang, E N; Yin, M Q; Liu, C; Ren, Z L

    2014-01-28

    In this study, a new disomic addition line, 12-5-2, with 44 chromosomes that was derived from BC3F2 descendants of the hybridization between Triticum aestivum cv. CN19 and Aegilops biuncialis was created and reported. 12-5-2 was immune to both powdery mildew and stripe rust and has stable fertility. Fluorescence in situ hybridization and C-banding revealed that 12-5-2 was a 1U(b) disomic addition line (ADL1U(b)). The seed storage protein electrophoresis showed that 12-5-2 presented all high molecular weight glutenin subunits (7 + 8 and 2 + 12) of CN19 and 2 new subunits that were designated Ux and Uy. Additionally, the flour quality parameters showed that the protein content, Zeleny sedimentation value, wet gluten content, and grain hardness of 12-5-2 were significantly higher than those of its parent CN19. Moreover, 5 pairs of the chromosome 1U(b)-specific polymerase chain reaction-based landmark unique gene markers, TNAC1021, TNAC1041, TNAC1071, TNAC1-01, and TNAC1-04, were also obtained. The new ADL1U(b) 12-5-2 could be a valuable source for wheat improvement, especially for wheat end-product quality and resistance to disease.

  16. Characterization of a new wheat-Aegilops biuncialis addition line conferring quality-associated HMW glutenin subunits.

    PubMed

    Zhou, J P; Yao, C H; Yang, E N; Yin, M Q; Liu, C; Ren, Z L

    2014-01-01

    In this study, a new disomic addition line, 12-5-2, with 44 chromosomes that was derived from BC3F2 descendants of the hybridization between Triticum aestivum cv. CN19 and Aegilops biuncialis was created and reported. 12-5-2 was immune to both powdery mildew and stripe rust and has stable fertility. Fluorescence in situ hybridization and C-banding revealed that 12-5-2 was a 1U(b) disomic addition line (ADL1U(b)). The seed storage protein electrophoresis showed that 12-5-2 presented all high molecular weight glutenin subunits (7 + 8 and 2 + 12) of CN19 and 2 new subunits that were designated Ux and Uy. Additionally, the flour quality parameters showed that the protein content, Zeleny sedimentation value, wet gluten content, and grain hardness of 12-5-2 were significantly higher than those of its parent CN19. Moreover, 5 pairs of the chromosome 1U(b)-specific polymerase chain reaction-based landmark unique gene markers, TNAC1021, TNAC1041, TNAC1071, TNAC1-01, and TNAC1-04, were also obtained. The new ADL1U(b) 12-5-2 could be a valuable source for wheat improvement, especially for wheat end-product quality and resistance to disease. PMID:24615031

  17. 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.

  18. 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.

  19. Conformations of low-molecular-weight lignin polymers in water

    DOE PAGESBeta

    Petridis, Loukas; Smith, Jeremy C.

    2016-01-13

    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 criticalmore » 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. As a result, an implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures.« less

  20. The versatile low-molecular-weight thiols: Beyond cell protection.

    PubMed

    Wang, Min; Zhao, Qunfei; Liu, Wen

    2015-12-01

    Low-molecular-weight (LMW) thiols are extensively involved in the maintenance of cellular redox potentials and the protection of cells from a variety of reactive chemical and electrophilic species. However, we recently found that the metabolic coupling of two LMW thiols - mycothiol (MSH) and ergothioneine (EGT) - programs the biosynthesis of the anti-infective agent lincomycin A. Remarkably, such a constructive role of the thiols in the biosynthesis of natural products has so far received relatively little attention. We speculate that the unusual thiol EGT might function as a chiral thiolation carrier (for modification) and a novel activator (for glycosylation) of sugar. Additionally, we examine recent evidence for LMW thiols (MSH and others) as sulfur donors of sulfur-containing natural products. Clearly, the LMW thiols have more diverse activities beyond cell protection, and more attention should be paid to the correlation of their functions with thiol-dependent enzymes.

  1. Does low molecular weight heparin shorten term labor?

    PubMed

    Ekman-Ordeberg, Gunvor; Akerud, Anna; Dubicke, Aurelija; Malmström, Anders; Hellgren, Margareta

    2010-01-01

    Dalteparin, a low molecular weight heparin (LMWH), is given to pregnant women with thrombotic disorders. Clinical observations together with the documented changes of heparan sulfate proteoglycans in normal and protracted labor fostered the idea that LMWH shortens delivery time. Labor time was retrospectively determined among nulliparous pregnant women treated with dalteparin because of previous venous thromboembolism (VTE), thrombophilia or acute VTE during current pregnancy. Their labor time was compared to matched untreated controls. The proportion of instrumental deliveries and neonatal outcome was also compared. The dalteparin-treated group showed a significantly (30%) shorter labor time compared to matched controls. Total instrumental deliveries were the same in the two groups but operative intervention due to protracted labor was significantly less common in dalteparin-treated women. There was no difference in neonatal outcome. Dalteparin most likely shortens parturition time and may decrease the number of operative interventions due to protracted labor.

  2. 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

  3. Dispersion in the presence of acetic acid or ammonia confers gliadin-like characteristics to the glutenin in wheat gluten.

    PubMed

    Murakami, Tetsuya; Kitabatake, Naofumi; Tani, Fumito

    2015-02-01

    Spray-dried gluten has unique properties and is commercially available in the food industry worldwide. In this study, we examined the viscoelastic properties of gluten powder prepared by dispersion in the presence of acetic acid or an ammonia solvent and then followed by lyophilization instead of a spray drying. Mixograph measurements showed that the acid- and ammonia-treated gluten powders had marked decreases in the time to peak dough resistance when compared with the control gluten powder. The integrals of the dough resistance and bandwidth for 3 min after peak dough resistance decreased in both treated gluten powders. Similar phenomena were observed when gliadin was supplemented to gluten powders. Basic and acidic conditions were applied to the acid- and ammonia-treated gluten powders, respectively, and the viscoelastic behaviors were found to depend on the pH in the gluten dispersion just before lyophilization. These behaviors suggest that gluten may assume a reversible change in viscoelasticity by a fluctuation in pH during gluten dispersion. SDS-PAGE showed that the extractable proteins substantially increased in some polymeric glutenins including the low molecular weight-glutenin subunit (LMW-GS) when the ammonia-treated gluten powder was extracted with 70% ethanol. In contrast, the extractable proteins markedly increased in many polymeric glutenins including the high molecular weight-glutenin subunit and/or the LMW-GS when the acid-treated gluten powder was extracted with 70% ethanol. It thus follows that the extractability of polymeric glutenin to ethanol increases similarly to gliadin when gluten is exposed to an acidic or a basic pH condition; therefore, glutenin adopts gliadin-like characteristics.

  4. Charge-based characterisation of high-molecular-weight glutenin subunits from common wheat by capillary isoelectric focusing.

    PubMed

    Salmanowicz, Bolesław P; Langner, Monika; Franaszek, Sławomir

    2014-11-01

    In this study, the capillary isoelectric focusing (CIEF) method for the separation and charge characterisation of the heterogeneity of high molecular-weight-glutenin subunits (HMW-GS) in common wheat (Triticum aestivum L.) using linear polyacrylamide (LPA) and polyvinyl alcohol (PVA) coated capillaries was developed. Particularly good repeatability and well-resolved charge isoform profiles were obtained by introducing a mixture of carrier ampholytes (pH 3-10 and pH 5-8), a high concentration of urea (6M) and SB3-12 as detergent in a sample solution during separation in a PVA-coated capillary. One major and one or two minor isoforms were observed for the individual HMW-GS. These isoforms were satisfactorily separated using a pH gradient into two groups: y-type isoforms and x-type isoforms encoded by the Glu-B1 locus with shorter migration times and remaining x-type isoforms with longer times. The method produced from eight to twelve isoforms of wheat HMW-GS with pI points in the range of 4.72-6.98. Generally, the minor isoforms were more acidic compared with the major isoform. The y-type subunits had an approximately neutral character (pI 6.70-6.98); however, x-types showed a weakly acidic character (pI 4.72-5.23), with the exception of subunits encoded by the Glu-B1 locus. The isoelectric point peak profiles were compared with capillary zone electrophoresis (CZE) electropherograms. Generally, the number of detected isoforms for the particular HMW-GS detected using both methods were similar.

  5. In situ reinforced polymers using low molecular weight compounds

    NASA Astrophysics Data System (ADS)

    Yordem, Onur Sinan

    2011-12-01

    The primary objective of this research is to generate reinforcing domains in situ during the processing of polymers by using phase separation techniques. Low molecular weight compounds were mixed with polymers where the process viscosity is reduced at process temperatures and mechanical properties are improved once the material system is cooled or reacted. Thermally induced phase separation and thermotropic phase transformation of low molar mass compounds were used in isotactic polypropylene (iPP) and poly(ether ether ketone) (PEEK) resins. Reaction induced phase separation was utilized in thermosets to generate anisotropic reinforcements. A new strategy to increase fracture toughness of materials was introduced. Simultaneously, enhancement in stiffness and reduction in process viscosity were also attained. Materials with improved rheological and mechanical properties were prepared by using thermotropic phase transformations of metal soaps in polymers (calcium stearate/iPP). Morphology and thermal properties were studied using WAXS, DSC and SEM. Mechanical and rheological investigation showed significant reduction in process viscosity and substantial improvement in fracture toughness were attained. Effects of molecular architecture of metal soaps were investigated in PEEK (calcium stearate/PEEK and sodium stearate/PEEK). The selected compounds reduced the process viscosity due to the high temperature co-continuous morphology of metal soaps. Unlike the iPP system that incorporates spherical particles, interaction between PEEK and metal soaps resulted in two discrete and co-continuous phases of PEEK and the metal stearates. DMA and melt rheology exhibited that sodium stearate/PEEK composites are stiffer. Effective moduli of secondary metal stearate phase were calculated using different composite theories, which suggested bicontinuous morphology to the metal soaps in PEEK. Use of low molecular weight crystallizable solvents was investigated in reactive systems

  6. 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

  7. Photoelectrical characterization of a new low molecular weight compound

    NASA Astrophysics Data System (ADS)

    Siderov, V.; Dobrikov, G. H.; Zhivkov, I.; Dobrikov, G. M.; Georgiev, Y.; Yordanov, R.; Honova, J.; Weiter, M.

    2014-12-01

    Photoelectrical characterization of a newly synthesized low molecular weight compound was carried out. 1,8-naphtalimide (chemical formula C32H34N4O5S) was originally synthesized and analyzed by NMR spectroscopy. Thin films were deposited in vacuum on commercially pre-patterned ITO covered glass substrates and the samples were prepared in clean room environment. The films deposited were characterized by SEM. Photoelectrical characteristics of the samples prepared were estimated by dark current-voltage measurement, spectral dependence of the photoconductivity and measurement under exposure with light, produced by solar simulator. Finally electroluminescence measurements were performed. It was found that the samples exhibit diode behaviour. The low values characterizing photovoltaic parameters obtained could be connected with the relative higher series resistance (Rseries). The predominant influence of Rseries is assumed as the relative high photoluminescence, measured from solution should be related to a relatively strong charge carrier photogeneration. This result is supported by electroluminescent measurement. Another reason for the low values of the photovoltaic parameters measured could be the non-optimized film thickness leading to a non-optimal light absorption and increased charge carrier recombination. The assumption for the predominant influence of Rseries is supported by the electroluminescent measurements.

  8. 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.

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

    PubMed

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

    2016-01-01

    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

  10. 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.

  11. 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

  12. Variability in glutenin subunit composition of Mediterranean durum wheat germplasm and its relationship with gluten strength.

    PubMed

    Nazco, R; Peña, R J; Ammar, K; Villegas, D; Crossa, J; Moragues, M; Royo, C

    2014-06-01

    The allelic composition at five glutenin loci was assessed by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (1D SDS-PAGE) on a set of 155 landraces (from 21 Mediterranean countries) and 18 representative modern varieties. Gluten strength was determined by SDS-sedimentation on samples grown under rainfed conditions during 3 years in north-eastern Spain. One hundred and fourteen alleles/banding patterns were identified (25 at Glu-1 and 89 at Glu-2/Glu-3 loci); 0·85 of them were in landraces at very low frequency and 0·72 were unreported. Genetic diversity index was 0·71 for landraces and 0·38 for modern varieties. All modern varieties exhibited medium to strong gluten type with none of their 13 banding patterns having a significant effect on gluten-strength type. Ten banding patterns significantly affected gluten strength in landraces. Alleles Glu-B1e (band 20), Glu-A3a (band 6), Glu-A3d (bands 6 + 11), Glu-B3a (bands 2 + 4+15 + 19) and Glu-B2a (band 12) significantly increased the SDS-value, and their effects were associated with their frequency. Two alleles, Glu-A3b (band 5) and Glu-B2b (null), significantly reduced gluten strength, but only the effect of the latter locus could be associated with its frequency. Only three rare banding patterns affected gluten strength significantly: Glu-B1a (band 7), found in six landraces, had a negative effect, whereas banding patterns 2 + 4+14 + 15 + 18 and 2 + 4+15 + 18 + 19 at Glu-B3 had a positive effect. Landraces with outstanding gluten strength were more frequent in eastern than in western Mediterranean countries. The geographical pattern displayed from the frequencies of Glu-A1c is discussed.

  13. Reductions with lithium in low molecular weight amines and ethylenediamine

    PubMed

    Garst; Dolby; Esfandiari; Fedoruk; Chamberlain; Avey

    2000-10-20

    Reductions of several types of compounds with lithium and ethylenediamine using low molecular weight amines as solvent are described. In all cases 1 mol of ethylenediamine or N, N'-dimethylethylenediamine per gram-atom of lithium was used. In some cases it was beneficial to add an alcohol as a proton donor. These reaction conditions were applied to the debenzylation of N-benzylamide and lactams which are refractory to hydrogenolysis with hydrogen and a catalyst. N-Benzylpilolactam 2, synthesized from pilocarpine hydrochloride in refluxing benzylamine, was debenzylated in good yield using 10 gram-atoms of lithium per mole (10 Li/mol) of 2 in n-propylamine. The debenzylation of N-benzyl-N-methyldecanoic acid amide, 4 (6 Li/mol), in t-butylamine/N, N'-dimethylethylenediamine gave N-methyldecanoic acid amide 6 in 70% yield. Alternatively, reduction of 4 (7 Li/mol) in t-butanol/n-propylamine/ethylenediamine gave n-decanal 12 in 36% yield. Using the same conditions, thioanisole, 1-adamantane-p-toluenesulfonamide, and 1-adamantane methyl p-toluenesulfonate were reduced with 3, 7, and 7.2 Li/mol of compound to give thiophenol (74%), adamantamine (91%), and 1-adamantane methanol (75%), respectively. In this solvent system naphthalene and 3-methyl-2-cyclohexene-1-one were reduced to isotetralin (74%) and 3-methyl cyclohexanone (quantitative) with 5 and 2.2 Li/mol of starting compound, respectively. Oximes and O-methyloximes were reduced to their corresponding amines using 5 and 8 Li/mol of compound, respectively. Anisole was also reduced to 1-methoxy-1,4-cyclohexadiene with 2.5 Li/mol of anisole. Undecanenitrile was reduced to undecylamine with 8.6 Li/mol. Additionally, a base-catalyzed formation of imidazolines from a nitrile and ethylenediamine was also explored.

  14. Permeability of low molecular weight organics through nanofiltration membranes.

    PubMed

    Meylan, Sébastien; Hammes, Frederik; Traber, Jacqueline; Salhi, Elisabeth; von Gunten, Urs; Pronk, Wouter

    2007-09-01

    The removal of natural organic matter (NOM) using nanofiltration (NF) is increasingly becoming an option for drinking water treatment. Low molecular weight (LMW) organic compounds are nevertheless only partially retained by such membranes. Bacterial regrowth and biofilm formation in the drinking water distribution system is favoured by the presence of such compounds, which in this context are considered as the assimilable organic carbon (AOC). In this study, the question of whether NF produces microbiologically stable water was addressed. Two NF membranes (cut-off of about 300Da) were tested with different natural and synthetic water samples in a cross-flow filtration unit. NOM was characterised by liquid chromatography with organic carbon detection (LC-OCD) using a size-exclusion column in addition to specific organic acid measurements, while AOC was measured in a batch growth bioassay. Similarly to high molecular weight organic compounds like polysaccharides or humic substances that have a permeability lower than 1%, charged LMW organic compounds were efficiently retained by the NF membranes tested and showed a permeability lower than 3%. However, LMW neutrals and hydrophobic organic compounds permeate to a higher extent through the membranes and have a permeability of up to 6% and 12%, respectively. Furthermore, AOC was poorly retained by NF and the apparent AOC concentration measured in the permeated water was above the proposed limit for microbiologically stable water. This indicates that the drinking water produced by NF might be biologically unstable in the distribution system. Nevertheless, in comparison with the raw water, NF significantly reduced the AOC concentration.

  15. [Practical use of low molecular weight heparins in angiology].

    PubMed

    Plettner, J L

    1991-01-01

    The recent development of low molecular weight heparins (LMWH), obtained by the depolymerization of standard non-fractioned heparin (NFH), considerably simplifies the course of anticoagulant treatments. They now allow effectively and safely dealing with the risks of thrombosis, both in hospital and at the patient's home. Their effectiveness for both the prevention and the treatment of thromboembolic accidents has been proved by many clinical trials. In comparison to standard heparin, the LMWHs still have a high anti-Xa activity, but their anti-IIa action is much reduced, thus preserving their antithrombotic power while reducing the hemorrhagic risks. Owing to their better bioavailability and longer half-life, they allow using in priority the subcutaneous route, reducing the frequency of the injections and simplifying surveillance, without impairing the effectiveness of the treatment. The prevention of thrombosis with LMWHs requires one daily subcutaneous dose. The control of the anti-Xa activity is not necessary for the doses used. Prior to initiating a curative treatment, it is essential to confirm the existence of thrombosis. When the diagnosis is definitive, the three LMWHs currently known are used after reconversion, at a dosage of 100 IU/kg/12 hrs. The anti-Xa activity, in samples taken 3 to 4 hours after the injection, must be maintained between 0.5 and 1 IU anti-Xa/ml. It is prudent to control the platelet level at D5 and D10, although thrombocytopenia is exceptional. The changeover treatment with antivitamins K (AVK), which is essential to prevent the recurrence of venous thrombosis, is initiated very early (2nd or 3rd day).(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Expression of low molecular weight proteins in patients with leukaemia.

    PubMed

    Sheikh, N; Abid, R; Qureshi, A W; Basheer, T

    2012-06-01

    The current study is conducted to observe the differences in the level of low molecular weight proteins in the sera of patients with leukaemia in comparison to healthy subjects (control group). The sera of patients with leukaemia showed 15 peaks in the densitometric curve in comparison to the seven peaks of the controls. The peaks in the experimental samples that coincide with those in the control were of 134.14, 113.15, 76.06, 63.25, 48.07, 22.85 and 16.47 kDa molecular weights, respectively. Most of the new peaks appeared between the proteins of molecular weight 36-29 kDa in the experimental groups. Mean density of the 134.14 kDa protein band showed an increase in the protein in experimental groups I and II only whereas 113.15 and 22.85 kDa protein were increased in all experimental groups of patients with leukaemia. The expression of 76.06 and 63.25 kDa protein fraction was downregulated in the patients with leukaemia. A decline in the level of the protein of 48.07 kDa was observed in patients with leukaemia except in group I. Unlike the other protein fractions, the level of the protein of 16.47 kDa was significantly (p < 0.05) increased with a maximum density in group II. Intergroup experimental) comparison revealed an increasing pattern of 95.44 and 89.21 kDa with maximum level in group III sera. However the protein fractions of 38.07 and 34.94 kDa varied in the serum with maximum density in Group IV Protein fractions of 32.92 and 31.24 kDa were expressed in all age groups of patients with leukaemia with a maximum density in group III whereas the percentage densities of 14.42 and 13.56 kDa protein were quite different. This preliminary study will provide a basis to study the role of different proteins in patients with leukaemia.

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

    PubMed

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

    2010-12-01

    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

  18. 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

  19. 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

  20. In vivo models of occupational asthma due to low molecular weight chemicals

    PubMed Central

    Hayes, J P; Taylor, A J Newman

    1995-01-01

    The aim was to review the development of in vivo models of asthma due to low molecular weight chemicals, in particular, those aspects that may be important to the understanding of occupational asthma in humans. PMID:7663640

  1. 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

  2. Preparation of low-molecular-weight hyaluronic acid by ozone treatment.

    PubMed

    Wu, Yue

    2012-06-20

    Recently, low-molecular-weight hyaluronic acid has been reported to have novel features, such as free radical scavenging activities, antioxidant activities, promotion of excisional wound healing, etc. In the present work, degradation of native hyaluronic acid by ozone treatment was performed for preparation of low-molecular-weight hyaluronic acid. The molecular weight of native hyaluronic acid was reduced from 1535 to 87 kDa for 120 min at 40°C. The rate of reduction of molecular weight was 94.33%. The FT-IR, 13C NMR, and UV-vis spectra suggested that there was no obvious modification of chemical structure of low-molecular-weight hyaluronic acid. The use of degradation of native hyaluronic acid by ozone treatment can be a useful alternative for production of low-molecular-weight hyaluronic acid.

  3. Influence of high-molecular-weight glutenin subunit composition at Glu-B1 locus on secondary and micro structures of gluten in wheat (Triticum aestivum L.).

    PubMed

    Gao, Xin; Liu, Tianhong; Yu, Jing; Li, Liqun; Feng, Yi; Li, Xuejun

    2016-04-15

    Glutenin is one of the critical gluten proteins that affect the processing quality of wheat dough. High-molecular-weight glutenin subunits (HMW-GS) affect rheological behavior of wheat dough. This research demonstrated the effects of four variations of HMW-GS composition at the Glu-B1 locus on secondary and micro structures of gluten and rheological properties of wheat dough, using the bread wheat Xinong 1330 and its three near-isogenic lines (NILs). Results indicated that the Amide I bands of the four wheat lines shifted slightly, but the secondary structure, such as content of α-helices, β-sheets, disulfide bands, tryptophan bands and tyrosine bands, differed significantly among the four NILs. The micro structure of gluten in NIL 2 (Bx14+By15) and NIL 3 (Bx17+By18) showed more cross linkage, with two contrasting patterns. Correlation analysis demonstrated that the content of β-sheets and disulfide bonds has a significant relationship with dough stability, which suggests that the secondary structures could be used as predictors of wheat quality.

  4. Low molecular weight C1q in systemic lupus erythematosus.

    PubMed

    Hoekzema, R; Hannema, A J; Swaak, T J; Paardekooper, J; Hack, C E

    1985-07-01

    In sera of patients suffering from an exacerbation of systemic lupus erythematosus (SLE), increased amounts of abnormal C1q were detected, contrasting with decreased or even undetectable levels of normal C1q in these sera. When analyzed immunochemically by double immunodiffusion, this low m.w. C1q (LMW-C1q) appeared to be identical with the defective C1q in serum of individuals with an inherited, homozygous inability to produce functional plasma C1q. These persons show a tendency to develop SLE-like syndromes. Like the genetically defective C1q, the abnormal C1q molecule in SLE sera was hemolytically inactive, did not incorporate in C1, was found in the supernatant of euglobulin-precipitated serum, and appeared in the break-through fraction of a cation-exchange column. Sucrose gradients and gel filtration analyses supported the putative identity of the molecules. SDS-PAGE and immunoblots revealed the presence of subunits that reacted with antibodies against C1q and confirmed the C1q-like nature of LMW-C1q. Low levels of LMW-C1q were also detected in serum and plasma of normal individuals. A radial immunodiffusion technique was used to measure LMW-C1q in the serum of 54 patients. Although these patients were not selected for parameters of disease activity, their levels of LMW-C1q were significantly higher than those of normal individuals and children with decreased C3 levels due to acute glomerulonephritis.

  5. Characterization of the Modes of Binding between Human Sweet Taste Receptor and Low-Molecular-Weight Sweet Compounds

    PubMed Central

    Nakajima, Ken-ichiro; Tanaka, Takaharu; Abe, Keiko; Misaka, Takumi; Ishiguro, Masaji

    2012-01-01

    One of the most distinctive features of human sweet taste perception is its broad tuning to chemically diverse compounds ranging from low-molecular-weight sweeteners to sweet-tasting proteins. Many reports suggest that the human sweet taste receptor (hT1R2–hT1R3), a heteromeric complex composed of T1R2 and T1R3 subunits belonging to the class C G protein–coupled receptor family, has multiple binding sites for these sweeteners. However, it remains unclear how the same receptor recognizes such diverse structures. Here we aim to characterize the modes of binding between hT1R2–hT1R3 and low-molecular-weight sweet compounds by functional analysis of a series of site-directed mutants and by molecular modeling–based docking simulation at the binding pocket formed on the large extracellular amino-terminal domain (ATD) of hT1R2. We successfully determined the amino acid residues responsible for binding to sweeteners in the cleft of hT1R2 ATD. Our results suggest that individual ligands have sets of specific residues for binding in correspondence with the chemical structures and other residues responsible for interacting with multiple ligands. PMID:22536376

  6. Characterization of the modes of binding between human sweet taste receptor and low-molecular-weight sweet compounds.

    PubMed

    Masuda, Katsuyoshi; Koizumi, Ayako; Nakajima, Ken-ichiro; Tanaka, Takaharu; Abe, Keiko; Misaka, Takumi; Ishiguro, Masaji

    2012-01-01

    One of the most distinctive features of human sweet taste perception is its broad tuning to chemically diverse compounds ranging from low-molecular-weight sweeteners to sweet-tasting proteins. Many reports suggest that the human sweet taste receptor (hT1R2-hT1R3), a heteromeric complex composed of T1R2 and T1R3 subunits belonging to the class C G protein-coupled receptor family, has multiple binding sites for these sweeteners. However, it remains unclear how the same receptor recognizes such diverse structures. Here we aim to characterize the modes of binding between hT1R2-hT1R3 and low-molecular-weight sweet compounds by functional analysis of a series of site-directed mutants and by molecular modeling-based docking simulation at the binding pocket formed on the large extracellular amino-terminal domain (ATD) of hT1R2. We successfully determined the amino acid residues responsible for binding to sweeteners in the cleft of hT1R2 ATD. Our results suggest that individual ligands have sets of specific residues for binding in correspondence with the chemical structures and other residues responsible for interacting with multiple ligands.

  7. Development of isohomoeoallelic lines within the wheat cv. Courtot for high molecular weight glutenin subunits: transfer of the Glu-D1 locus to chromosome 1A.

    PubMed

    Dumur, J; Branlard, G; Tanguy, A-M; Dardevet, M; Coriton, O; Huteau, V; Lemoine, J; Jahier, Joseph

    2009-08-01

    Wheat quality depends on protein composition and grain protein content. High molecular weight glutenin subunits (HMW-GS) play an important role in determining the viscoelastic properties of gluten. In an attempt to improve the bread-making quality of hexaploid wheat by elaborating novel HMW-GS combinations, a fragment of wheat chromosome 1D containing the Glu-D1 locus encoding the Dx2+Dy12 subunits was translocated to the long arm of chromosome 1A using the ph1b mutation. The partially isohomoeoallelic line selected was characterized using cytogenetical and molecular approaches to assess the amount of chromatin introgressed in the translocated 1A chromosome. Triple-target genomic in situ hybridization indicated that the translocated 1A chromosome had a terminal 1D segment representing 25% of the length of the recombinant long arm. The translocation was also identified on the long arm using molecular markers, and its length was estimated with a minimum of 91 cM. Proteome analysis was performed on total endosperm proteins. Out of the 152 major spots detected, 9 spots were up-regulated and 4 spots were down-regulated. Most of these proteins were identified as alpha-, beta-, gamma-gliadins assigned to the chromosomes of homoeologous groups 1 and 6. Quantitative variations in the HMW-GS were only observed in subunit Dy12 in response to duplication of the Glu-D1 locus.

  8. 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.

  9. Low molecular-weight phenols in Tannat wines made by alternative winemaking procedures.

    PubMed

    Favre, Guzmán; Peña-Neira, Álvaro; Baldi, Cecilia; Hernández, Natalia; Traverso, Sofía; Gil, Graciela; González-Neves, Gustavo

    2014-09-01

    Low molecular weight phenols of Tannat red wines produced by Traditional Maceration (TM), Prefermentative Cold Maceration (PCM), Maceration Enzyme (ENZ) and grape-Seed Tannins additions (ST), were performed and discussed. Alternatives to TM increased wine phenolic contents but unequally, ST increased mainly smaller flavans-3-ol, PCM anthocyanins and ENZ proanthocyanidins (up to 2250 mg/L). However low molecular weight flavan-3-ols remained below 9 mg/L in all wines, showing that there is not necessarily a correspondence between wine richness in total tannins and flavan-3-ols contents at low molecular weight. PCM wines had particularly high concentrations of tyrosol and tryptophol, yeast metabolism derived compounds. The use of grape-seed enological tannins did not increase grape seed derived phenolic compounds such as gallic acid. Caftaric acid was found in concentrations much higher than those reported in other grape varieties. Wine phenolic content and composition was considerably affected by the winemaking procedures tested.

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  16. Anticancer properties of low molecular weight oat beta-glucan – An in vitro study.

    PubMed

    Choromanska, Anna; Kulbacka, Julita; Rembialkowska, Nina; Pilat, Justyna; Oledzki, Remigiusz; Harasym, Joanna; Saczko, Jolanta

    2015-09-01

    Anticancer properties of 1-3, 1-4 oat beta glucan are under intensive investigation now. Antitumor characteristic of fungi and yeast beta-glucans have been widely recognized, but those polysaccharides are mostly insoluble which creates several problems especially in topical formulation. Also high molecular weight oat beta-glucans reveal high viscosity which restricts its application. According to those problems in the current study the antitumor activities of low molecular weight beta-glucan derived from oats were investigated in cancer cells: Me45, A431 and normal HaCaT and murine macrophages P388/D1. The low molecular weight beta-glucan from oat significantly deceased cancer cells viability, while for the normal cells it was non-toxic. It was observed that with the increasing incubation time and the beta-glucan concentration the cancer cells viability significantly deceased. Furthermore for the normal cells the low molecular weight beta-glucan from oat was non-toxic. Immunocytochemical ABC analysis showed that beta-glucan induced strong expression of caspase-12 in both cancer cell lines, while in HaCaT cells ABC reaction was significantly lower and in P388/D1 cell line ABC reaction was negative. Our preliminary studies show strong anti-tumor properties of new low molecular weight beta-glucan from oat and at the same time no toxicity for normal cells.

  17. 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...

  18. Comparative gene transfer efficiency of low molecular weight polylysine DNA-condensing peptides.

    PubMed

    McKenzie, D L; Collard, W T; Rice, K G

    1999-10-01

    In a previous report (M.S. Wadhwa et al. (1997) Bioconjugate Chem. 8, 81-88), we synthesized a panel of polylysine-containing peptides and determined that a minimal repeating lysine chain of 18 residues followed by a tryptophan and an alkylated cysteine residue (AlkCWK18) resulted in the formation of optimal size (78 nm diameter) plasmid DNA condensates that mediated efficient in vitro gene transfer. Shorter polylysine chains produced larger DNA condensates and mediated much lower gene expression while longer lysine chains were equivalent to AlkCWK18. Surprisingly, AlkCWK18 (molecular weight 2672) was a much better gene transfer agent than commercially available low molecular weight polylysine (molecular weight 1000-4000), despite its similar molecular weight. Possible explanations were that the cysteine or tryptophan residue in AlkCWK18 contributed to the DNA binding and the formation of small condensates or that the homogeneity of AlkCWK18 relative to low molecular weight polylysine facilitated optimal condensation. To test these hypotheses, the present study prepared AlkCYK18 and K20 and used these to form DNA condensates and conduct in vitro gene transfer. The results established that DNA condensates prepared with either AlkCYK18 or K20 possessed identical particle size and mediated in vitro gene transfer efficiencies that were indistinguishable from AlkCWK18 DNA condensates, eliminating the possibility of contributions from cysteine or tryptophan. However, a detailed chromatographic and electrospray mass spectrometry analysis of low molecular weight polylysine revealed it to possess a much lower than anticipated average chain length of dp 6. Thus, the short chain length of low molecular weight polylysine explains its inability to form small DNA condensates and mediate efficient gene transfer relative to AlkCWK18 DNA condensates. These experiments further emphasize the need to develop homogenous low molecular weight carrier molecules for nonviral gene delivery.

  19. 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.

  20. 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

  1. 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

  2. About the origin of European spelt ( Triticum spelta L.): allelic differentiation of the HMW Glutenin B1-1 and A1-2 subunit genes.

    PubMed

    Blatter, R H E; Jacomet, S; Schlumbaum, A

    2004-01-01

    To investigate the origin of European spelt ( Triticum spelta L., genome AABBDD) and its relation to bread wheat ( Triticum aestivum L., AABBDD), we analysed an approximately 1-kb sequence, including a part of the promoter and the coding region, of the high-molecular-weight (HMW) glutenin B1-1 and A1-2 subunit genes in 58 accessions of hexa- and tetraploid wheat from different geographical regions. Six Glu-B1-1 and five Glu-A1-2 alleles were identified based on 21 and 19 informative sites, respectively, which suggests a polyphyletic origin of the A- and B-genomes of hexaploid wheat. In both genes, a group of alleles clustered in a distinct, so-called beta subclade. High frequencies of alleles from the Glu-B1-1 and Glu-A1-2 beta subclades differentiated European spelt from Asian spelt and bread wheat. This indicates different origins of European and Asian spelt, and that European spelt does not derive from the hulled progenitors of bread wheat. The conjoint differentiation of alleles of the A- and B-genome in European spelt suggests the introgression of a tetraploid wheat into free-threshing hexaploid wheat as the origin of European spelt.

  3. [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

  4. [The effect of low molecular weight substances on the human skin. Molecular mechanisms and their consequences].

    PubMed

    Merk, H F; Baron, J M

    2004-12-01

    Interactions between low molecular weight compounds with cells of the skin result in reactions with different proteins which enable the uptake, metabolism and efflux of these compounds. It is unlikely, that small molecular weight compounds can achieve pharmacological concentrations within cells by diffusion alone. The pattern of influx proteins of keratinocytes is different from that of hepatocytes. If the balance between these systems is disturbed, the skin may become unable to function as a protective organ which can result in diseases including cancer or-more frequently-allergic contact dermatitis. Recent investigations of the sensitization to fragrances and p-phenylenediamine are discussed. An improved understanding of the metabolism of low molecular weight compounds can lead to new therapeutic strategies. One example is the introduction of photodynamic therapy with topical applied porphyrin precursors.

  5. 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

  6. Intermolecular complexation of low-molecular-weight succinoglycans directs solubility enhancement of pindolol.

    PubMed

    Kim, Kyoungtea; Cho, Eunae; Choi, Jae Min; Kim, Hwanhee; Jang, Ahri; Choi, Youngjin; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

    2014-06-15

    The low-molecular-weight succinoglycans isolated from Sinorhizobium meliloti are repeating octasaccharide units consisting of monomers, dimers, and trimers. Pindolol is a beta-blocker used to treat cardiovascular disorders. We investigated the formation of complexes between pindolol and low-molecular-weight succinoglycan monomers (SGs). Even though SGs have a linear structure, the solubility of pindolol in the presence of SGs was increased up to 7-fold compared with methyl-β-cyclodextrin reported as the best solubilizer of pindolol. Complexation of SGs with pindolol was confirmed by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Formation constants of complexes were determined from phase solubility diagrams. Conformation of complex was suggested based on a molecular docking study. The present study indicated that formation of pindolol/SGs complexes not only resulted in increased pindolol solubility but also could be useful for improving its clinical application as it did not affect cell viability.

  7. [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.

  8. 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.

  9. 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.

  10. Characterization of Rhizobial Isolates of Phaseolus vulgaris by Staircase Electrophoresis of Low-Molecular-Weight RNA

    PubMed Central

    Velázquez, Encarna; Martínez-Romero, Esperanza; Rodríguez-Navarro, Dulce Nombre; Trujillo, Martha E.; Daza, Antonio; Mateos, Pedro F.; Martínez-Molina, Eustoquio; van Berkum, Peter

    2001-01-01

    Low-molecular-weight (LMW) RNA molecules were analyzed to characterize rhizobial isolates that nodulate the common bean growing in Spain. Since LMW RNA profiles, determined by staircase electrophoresis, varied across the rhizobial species nodulating beans, we demonstrated that bean isolates recovered from Spanish soils presumptively could be characterized as Rhizobium etli, Rhizobium gallicum, Rhizobium giardinii, Rhizobium leguminosarum bv. viciae and bv. trifolii, and Sinorhizobium fredii. PMID:11157280

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Ultrarapid electrophoretic transfer of high and low molecular weight proteins using heat.

    PubMed

    Kurien, Biji T; Scofield, R Hal

    2009-01-01

    An ultrarapid 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 degrees 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.

  16. Post-translational modification and stability of low molecular weight cyclin E.

    PubMed

    Mull, B B; Cox, J; Bui, T; Keyomarsi, K

    2009-09-01

    Our laboratory has previously described the presence of five tumor-specific low molecular weight isoforms of cyclin E in both tumor cell lines and breast cancer patient biopsies. We have also shown that one of these low forms arises from an alternate start site, whereas the other four appear as two sets of doublets following cleavage through an elastase-like enzyme. However, the origin of both sets of doublets was unknown. Here, we demonstrate that the larger isoform of each doublet is the result of phosphorylation at a key degradation site. Through site-directed mutagenesis of different phosphorylation sites within the cyclin E protein, we discovered that phosphorylation of threonine 395 is responsible for generating the larger isoform of each doublet. Because phosphorylation of threonine 395 has been linked to the proteasome-mediated degradation of full length cyclin E, we examined the stability of T395A phospho-mutants in both non-tumorigenic mammary epithelial cells and tumor cells. The results revealed that the low molecular weight isoforms appear to be stable in both a tumor cell line and a non-tumor forming cell line regardless of the presence of this critical phosphorylation site. The stability of low molecular weight cyclin E may have implications for both tumorigenesis and treatment of tumors expressing them.

  17. 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

  18. A low-molecular-weight inhibitor of the neutral proteinase from rat intestinal smooth muscle.

    PubMed Central

    Carney, I T; Curtis, C G; Kay, J K; Birket, N

    1980-01-01

    1. Rat intestinal smooth muscle was shown to contain endogenous inhibitory activity towards the neutral trypsin-like muscle proteinase described previously [Beynon & Kay (1978) Biochem. J. 173, 291--298]. 2. Comtamination of the muscle tissue by mucosal, blood and pancreatic inhibitors was shown to be unlikely. 3. The inhibitory activity was resolved into high- and low-molecular-weight components. 4. The low-molecular-weight component was purified to homogeneity. It has a molecular weight of approx. 9000 and was stable over the pH range 3--11. 5. It inhibited the muscle proteinase competitively (Ki congruent to t microM), but had no effect on any of the other proteinases tested. 6. Leupeptin also inhibited the muscle proteinase competitively (Ki congruent to 0.3 microM), whereas the low-molecular weight proteins gastrin, glucagon and insulin B-chain had very little effect. 7. A role for a weakly binding inhibitor in modulating the influence of the neutral proteinase on intracellular protein degradation is considered. Images Fig. 4. PMID:7396824

  19. HMW and LMW glutenin alleles among putative tetraploid and hexaploid European spelt wheat (Triticum spelta L.) progenitors.

    PubMed

    Yan, Y; Hsam, S L K; Yu, J Z; Jiang, Y; Ohtsuka, I; Zeller, F J

    2003-11-01

    The allelic compositions of high- and low-molecular-weight subunits of glutenins (HMW-GS and LMW-GS) among European spelt ( Triticum spelta L.) and related hexaploid and tetraploid Triticum species were investigated by one- and two-dimensional polyacrylamide-gel electrophoresis (PAGE) and capillary electrophoresis (CE). A total of seven novel glutenin alleles (designated A1a*, B1d*, B1g*, B1f*, B1j*, D1a* at Glu-1 and A3h at the Glu-3 loci, respectively) in European spelt wheat were detected by SDS-PAGE, which were confirmed further by employing A-PAGE and CE methods. Particularly, two HMW-GS alleles, Glu-B1d* coding the subunits 6.1 and 22.1, and Glu-B1f* coding the subunits 13 and 22*, were found to occur in European spelt with frequencies of 32.34% and 5.11%, respectively. These two alleles were present in cultivated emmer (Triticum dicoccum), but they were not observed in bread wheat (Triticum aestivum L.). The allele Glu-B1g* coding for 13* and 19* subunits found in spelt wheat was also detected in club wheat (Triticum compactum L.). Additionally, two alleles coding for LMW-GS, Glu-A3h and Glu-B3d, occurred with high frequencies in spelt, club and cultivated emmer wheat, whereas these were not found or present with very low frequencies in bread wheat. Our results strongly support the secondary origin hypothesis, namely European spelt wheat originated from hybridization between cultivated emmer and club wheat. This is also confirmed experimentally by the artificial synthesis of spelt through crossing between old European emmer wheat, T. dicoccum and club wheat, T. compactum.

  20. Coexpression of the high molecular weight glutenin subunit 1Ax1 and puroindoline improves dough mixing properties in durum wheat (Triticum turgidum L. ssp. durum).

    PubMed

    Li, Yin; Wang, Qiong; Li, Xiaoyan; Xiao, Xin; Sun, Fusheng; Wang, Cheng; Hu, Wei; Feng, Zhijuan; Chang, Junli; Chen, Mingjie; Wang, Yuesheng; Li, Kexiu; Yang, Guangxiao; He, Guangyuan

    2012-01-01

    Wheat end-use quality mainly derives from two interrelated characteristics: the compositions of gluten proteins and grain hardness. The composition of gluten proteins determines dough rheological properties and thus confers the unique viscoelastic property on dough. One group of gluten proteins, high molecular weight glutenin subunits (HMW-GS), plays an important role in dough functional properties. On the other hand, grain hardness, which influences the milling process of flour, is controlled by Puroindoline a (Pina) and Puroindoline b (Pinb) genes. However, little is known about the combined effects of HMW-GS and PINs on dough functional properties. In this study, we crossed a Pina-expressing transgenic line with a 1Ax1-expressing line of durum wheat and screened out lines coexpressing 1Ax1 and Pina or lines expressing either 1Ax1 or Pina. Dough mixing analysis of these lines demonstrated that expression of 1Ax1 improved both dough strength and over-mixing tolerance, while expression of PINA detrimentally affected the dough resistance to extension. In lines coexpressing 1Ax1 and Pina, faster hydration of flour during mixing was observed possibly due to the lower water absorption and damaged starch caused by PINA expression. In addition, expression of 1Ax1 appeared to compensate the detrimental effect of PINA on dough resistance to extension. Consequently, coexpression of 1Ax1 and PINA in durum wheat had combined effects on dough mixing behaviors with a better dough strength and resistance to extension than those from lines expressing either 1Ax1 or Pina. The results in our study suggest that simultaneous modulation of dough strength and grain hardness in durum wheat could significantly improve its breadmaking quality and may not even impair its pastamaking potential. Therefore, coexpression of 1Ax1 and PINA in durum wheat has useful implications for breeding durum wheat with dual functionality (for pasta and bread) and may improve the economic values of durum

  1. Biocompatibility of low molecular weight polymers for two-phase partitioning bioreactors.

    PubMed

    Harris, Jesse; Daugulis, Andrew J

    2015-12-01

    Two phase partitioning bioreactors (TPPBs) improve the efficiency of fermentative processes by limiting the exposure of microorganisms to toxic solutes by sequestering them into a non-aqueous phase (NAP). A potential limitation of this technology, when using immiscible organic solvents as the NAP, is the cytoxicity that these materials may exert on the microbes. An improved TPPB configuration is one in which polymeric NAPs are used to replace organic solvents in order to take advantage of their low cost, improved handling qualities, and biocompatibility. A recent study has shown that low molecular weight polymers may confer improved solute uptake relative to high molecular weight polymers (i.e., have higher partition coefficients), but it is unknown whether sufficiently low molecular weight polymers may inhibit cell growth. This study has investigated the biocompatibility of a range of low molecular weight polymers, and compared trends in biocompatibility to the well-established "critical log P" concept. This was achieved by determining the biocompatibility of polypropylene glycol polymers over a molecular weight (MW) range of 425-4,000 to Saccharomyces cerevisiae and Pseudomonas putida, two organisms which have been previously used in TPPB systems. The lower MW polymers were shown to have lower average log P values, and showed more cytotoxicity than polymers of the same structure but with higher molecular weight. Since polymers are generally polydisperse (i.e., polymer samples contain a distribution of MWs), removal of the lower MW fractions via water washing was found to result in improved polymer biocompatibility. These results suggest that the critical log P concept remains useful for describing the toxicity of polymeric substances of different MWs, although it is complicated by the presence of the low MW fractions in the polymers arising from polydispersity.

  2. 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.

  3. 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

  4. 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

  5. [Venous thrombo-embolic disease in cancer. Low molecular weight heparin indications].

    PubMed

    Nou, M; Laroche, J-P

    2016-05-01

    Cancer and venous thrombo-embolic disease (VTE) are closely related. Indeed, cancer can reveal VTE and VTE can be the first sign of cancer. Low molecular weight heparin (LWMH) is now the first line treatment in cancer patients. Compliance with marketing authorizations and guidelines are crucial for patient-centered decision-making. This work deals with the prescription of LWMH in patients who develop VTE during cancer in order to better recognize what should or should not be done. The patient's wishes must be taken into consideration when making the final therapeutic decision. The other treatments are discussed: vitamin K antagonists and direct oral anticoagulants (DOACs) may be useful. PMID:27146099

  6. Fluorocarbon Modified Low-Molecular-Weight Polyethylenimine for siRNA Delivery.

    PubMed

    Johnson, Mark E; Shon, Judy; Guan, Brian M; Patterson, Joseph P; Oldenhuis, Nathan J; Eldredge, Alexander C; Gianneschi, Nathan C; Guan, Zhibin

    2016-08-17

    We report the synthesis and study of fluorocarbon (FC) modified polyethylenimine (PEI) for the purpose of siRNA delivery. Low-molecular-weight PEI (Mn = 600) was functionalized with fluorocarbon epoxides of varying length. All FC-modified samples with greater than 2.0 equiv of FC epoxide per PEI induced potent gene silencing in vitro. Compared to hydrocarbon (HC) analogues, the FC vectors showed greater general silencing efficacy, higher cell uptake, and reduced association with serum components. Collectively, the data suggest that modification of polyamines with FCs is a promising approach for the discovery of novel vectors for siRNA delivery.

  7. Preparation and Characterization of Low Molecular Weight Heparin by Liquid Phase Plasma Method.

    PubMed

    Lee, Do-Jin; Kim, Hangun; Kim, Byung Hoon; Park, Young-Kwon; Lee, Heon; Park, Sung Hoon; Jung, Sang-Chul

    2015-08-01

    An liquid phase plasma process system was applied to the production of low molecular weight heparin. The molecular weight of produed heparin decreased with increasing liquid phase plasma treatment time. The abscission of the chemical bonds between the constituents of heparin by liquid phase plasma reaction did not alter the characteristics of heparin. Formation of any by-products due to side reaction was not observed. It is suggested that heparin was depolymerized by active oxygen radicals produced during the liquid phase plasma reaction.

  8. 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.

  9. 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.

  10. Mass spectrometric techniques for characterizing low-molecular-weight resins used as paint varnishes.

    PubMed

    Bonaduce, I; Colombini, M P; Degano, I; Di Girolamo, F; La Nasa, J; Modugno, F; Orsini, S

    2013-01-01

    The molecular structure of three low-molecular-weight resins used as paint varnishes has been characterized by use of an approach based on three different mass spectrometric techniques. We investigated the ketone resin MS2A, the aldehyde resin Laropal A81, and the hydrocarbon resin Regalrez 1094, now commonly used in restoration. To date, the molecular structures of these resins have not been completely elucidated. To improve current knowledge of the chemical composition of these materials, information obtained by gas chromatography-mass spectrometry (GC/MS), pyrolysis-gas chromatography-mass spectrometry (Py/GC/MS), and electrospray ionization mass spectrometry (ESI-Q-ToF) was combined. Analysis, in solution, of the whole polymeric fraction of the resins by flow-injection ESI-Q-ToF, and of the non-polymeric fraction by GC-MS, enabled us to identify previously unreported features of the polymer structures. In addition, the Py-GC/MS profiles that we obtained will help to enhance the databases currently available in the literature. The proposed approach can be extended to other low-molecular-weight resins used as varnishes in conservation.

  11. Weak oligomerization of low-molecular-weight protein tyrosine phosphatase is conserved from mammals to bacteria.

    PubMed

    Blobel, Jascha; Bernadó, Pau; Xu, Huimin; Jin, Changwen; Pons, Miquel

    2009-08-01

    The well-characterized self-association of a mammalian low-molecular-weight protein tyrosine phosphatase (lmwPTP) produces inactive oligomers that are in equilibrium with active monomers. A role of the inactive oligomers as supramolecular proenzymes has been suggested. The oligomerization equilibrium of YwlE, a lmwPTP from Bacillus subtilis, was studied by NMR. Chemical shift data and NMR relaxation confirm that dimerization takes place through the enzyme's active site, and is fully equivalent to the dimerization previously characterized in a eukaryotic low-molecular-weight phosphatase, with similarly large dissociation constants. The similarity between the oligomerization of prokaryotic and eukaryotic phosphatases extends beyond the dimer and involves higher order oligomers detected by NMR relaxation analysis at high protein concentrations. The conservation across different kingdoms of life suggests a physiological role for lmwPTP oligomerization in spite of the weak association observed in vitro. Structural data suggest that substrate modulation of the oligomerization equilibrium could be a regulatory mechanism leading to the generation of signaling pulses. The presence of a phenylalanine residue in the dimerization site of YwlE, replacing a tyrosine residue conserved in all eukaryotic lmwPTPs, demonstrates that lmwPTP regulation by oligomerization can be independent from tyrosine phosphorylation.

  12. 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

  13. Insights into the toxicological properties of a low molecular weight fraction from Zoanthus sociatus (Cnidaria).

    PubMed

    Domínguez-Pérez, Dany; Diaz-Garcia, Carlos Manlio; García-Delgado, Neivys; Sierra-Gómez, Yusvel; Castañeda, Olga; Antunes, Agostinho

    2013-08-13

    The phylum Cnidaria is an ancient group of venomous animals, specialized in the production and delivery of toxins. Many species belonging to the class Anthozoa have been studied and their venoms often contain a group of peptides, less than 10 kDa, that act upon ion channels. These peptides and their targets interact with high affinity producing neurotoxic and cardiotoxic effects, and even death, depending on the dose and the administration pathway. Zoanthiniaria is an order of the Subclass Hexacorallia, class Anthozoa, and unlike sea anemone (order Actiniaria), neither its diversity of toxins nor the in vivo effects of the venoms has been exhaustively explored. In this study we assessed some toxicological tests on mice with a low molecular weight fraction obtained by gel filtration in Sephadex G-50 from Zoanthus sociatus crude extract. The gel filtration chromatogram at 280 nm revealed two major peaks, the highest absorbance corresponding to the low molecular weight fraction. The toxicological effects seem to be mostly autonomic and cardiotoxic, causing death in a dose dependent manner with a LD50 of 792 μg/kg. Moreover, at a dose of 600 μg/kg the active fraction accelerated the KCl-induced lethality in mice.

  14. Low-molecular-weight carboxylic acids produced from hydrothermal treatment of organic wastes.

    PubMed

    Quitain, Armando T; Faisal, Muhammad; Kang, Kilyoon; Daimon, Hiroyuki; Fujie, Koichi

    2002-07-22

    This article reports production of low-molecular-weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds (i.e. domestic sludge, proteinaceous, cellulosic and plastic wastes) with or without oxidant (H(2)O(2)). Organic acids such as acetic, formic, propionic, succinic and lactic acids were obtained in significant amounts. At 623 K (16.5 MPa), acetic acid of about 26 mg/g dry waste fish entrails was obtained. This increased to 42 mg/g dry waste fish entrails in the presence of H(2)O(2). Experiments on glucose to represent cellulosic wastes were also carried out, getting acetic acid of about 29 mg/g glucose. The study was extended to terephthalic acid and glyceraldehyde, reaction intermediates of hydrothermal treatment of polyethylene terephthalate (PET) plastic wastes and glucose, respectively. In addition, production of lactic acid, one of the interesting low-molecular-weight carboxylic acids, was discussed on the viewpoint of resources recovery. Studies on temperature dependence of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general, results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product.

  15. 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

  16. Determination of the low molecular weight fraction of food-grade carrageenans.

    PubMed

    Spichtig, Véronique; Austin, Sean

    2008-01-01

    Recently there has been some debate regarding the presence and associated health risk of low molecular weight carrageenan in foodstuffs. Unfortunately measurement of the low molecular weight tail (LMT) of food-grade carrageenans (defined here as the carrageenan having relative molecular mass (Mr) below 50,000) is not trivial, largely due to its low abundance. So far methods employing light scattering have been unsuccessful in producing reproducible results, probably due to the poor detector response at low masses. In this work a method based on high performance size exclusion chromatography coupled to a refractive index detector (HPSEC-RI) has been used for the measurement of the LMT in food-grade carrageenan ingredients and in a carrageenan-containing finished product (a jelly). Over the course of half a year, 19 measurements were made on a reference carrageenan; the results demonstrated that the method had excellent reproducibility. Applied to a number of different carrageenan ingredients, it was found that, in general, the LMT represents less than 8% of the total carrageenan in ingredients, and under the correct conditions increases little during food processing. The data also indicated that pH appears to be a critical factor during food processing and pH levels below 4.0 should be avoided.

  17. 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.

  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. 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.

  20. 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.

  1. 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.

  2. Capillary Electrophoresis-Mass Spectrometry for the Analysis of Heparin Oligosaccharides and Low Molecular Weight Heparin.

    PubMed

    Sun, Xiaojun; Lin, Lei; Liu, Xinyue; Zhang, Fuming; Chi, Lianli; Xia, Qiangwei; Linhardt, Robert J

    2016-02-01

    Heparins, highly sulfated, linear polysaccharides also known as glycosaminoglycans, are among the most challenging biopolymers to analyze. Hyphenated techniques in conjunction with mass spectrometry (MS) offer rapid analysis of complex glycosaminoglycan mixtures, providing detailed structural and quantitative data. Previous analytical approaches have often relied on liquid chromatography (LC)-MS, and some have limitations including long separation times, low resolution of oligosaccharide mixtures, incompatibility of eluents, and often require oligosaccharide derivatization. This study examines the analysis of glycosaminoglycan oligosaccharides using a novel electrokinetic pump-based capillary electrophoresis (CE)-MS interface. CE separation and electrospray were optimized using a volatile ammonium bicarbonate electrolyte and a methanol-formic acid sheath fluid. The online analyses of highly sulfated heparin oligosaccharides, ranging from disaccharides to low molecular weight heparins, were performed within a 10 min time frame, offering an opportunity for higher-throughput analysis. Disaccharide compositional analysis as well as top-down analysis of low molecular weight heparin was demonstrated. Using normal polarity CE separation and positive-ion electrospray ionization MS, excellent run-to-run reproducibility (relative standard deviation of 3.6-5.1% for peak area and 0.2-0.4% for peak migration time) and sensitivity (limit of quantification of 2.0-5.9 ng/mL and limit of detection of 0.6-1.8 ng/mL) could be achieved.

  3. 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...

  4. Thromboprophylaxis with low-molecular-weight heparin in outpatients with plaster-cast immobilisation of the leg.

    PubMed

    Kock, H J; Schmit-Neuerburg, K P; Hanke, J; Rudofsky, G; Hirche, H

    1995-08-19

    Deep-vein thrombosis is common after plaster-cast immobilisation for traumatic injury. We did a randomised prospective study of the effect of low-molecular-weight heparin on the incidence of deep-vein thrombosis in patients with minor injuries treated with plaster-cast immobilisation of the leg. A control group (n = 163) received no prophylaxis, the prophylaxis group received low-molecular-weight heparin once daily (n = 176). The incidence of deep-vein thrombosis in the prophylaxis group was 0% (one tailed p < 0.006) vs 4.3% in the control group. No severe side-effects of low-molecular-weight heparin were observed. Thromboprophylaxis with low-molecular-weight heparin once daily is effective in reducing the risk of deep-vein thrombosis in outpatients with plaster-cast immobilisation of the leg.

  5. 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

  6. Photochemical alkylation of inorganic selenium in the presence of low molecular weight organic acids.

    PubMed

    Guo, Xuming; Sturgeon, Ralph E; Mester, Zoltán; Gardner, Graeme J

    2003-12-15

    Using a flow-through photochemical reactor and a low pressure mercury lamp as a UV source, alkyl selenium species are formed from inorganic selenium(IV) in the presence of low molecular weight organic acids (LMW acids). The volatile alkyl Se species were cryogenically trapped and identified by GC-MS and GC-ICP-MS. In the presence of formic, acetic, propionic and malonic acids, inorganic selenium(IV) is converted by UV irradiation to volatile selenium hydride and carbonyl, dimethylselenide and diethylselenide, respectively. Se(IV) was successfully removed from contaminated agricultural drainage waters (California, U.S.A.) using a batch photoreactor system Se. Photochemical alkylation may thus offer a promising means of converting toxic selenium salts, present in contaminated water, to less toxic dimethylselenide. The LMW acids and photochemical alkylation process may also be key to understanding the source of atmospheric selenium and are likely involved in its mobility in the natural anaerobic environment.

  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. 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

  9. Increased production of low molecular weight recombinant proteins in Escherichia coli.

    PubMed

    Belagaje, R M; Reams, S G; Ly, S C; Prouty, W F

    1997-09-01

    A general method for obtaining high-level production of low molecular weight proteins in Escherichia coli is described. This method is based on the use of a novel Met-Xaa-protein construction which is formed by insertion of a single amino acid residue (preferably Arginine or Lysine) between the N-terminal methionine and the protein of interest. The utility of this method is illustrated by examples for achieving high-level production of human insulin-like growth factor-1, human proinsulin, and their analogs. Furthermore, highly produced insulin-like growth factor-1 derivatives and human proinsulin analogs are converted to their natural sequences by removal of dipeptides with cathepsin C.

  10. Ultra-low-molecular-weight heparins: precise structural features impacting specific anticoagulant activities.

    PubMed

    Lima, Marcelo A; Viskov, Christian; Herman, Frederic; Gray, Angel L; de Farias, Eduardo H C; Cavalheiro, Renan P; Sassaki, Guilherme L; Hoppensteadt, Debra; Fareed, Jawed; Nader, Helena B

    2013-03-01

    Ultra-low-molecular-weight heparins (ULMWHs) with better efficacy and safety ratios are under development; however, there are few structural data available. The main structural features and molecular weight of ULMWHs were studied and compared to enoxaparin. Their monosaccharide composition and average molecular weights were determined and preparations studied by nuclear magnetic resonance spectroscopy, scanning ultraviolet spectroscopy, circular dichroism and gel permeation chromatography. In general, ULMWHs presented higher 3-O-sulphated glucosamine and unsaturated uronic acid residues, the latter being comparable with their higher degree of depolymerisation. The analysis showed that ULMWHs are structurally related to LMWHs; however, their monosaccharide/oligosaccharide compositions and average molecular weights differed considerably explaining their different anticoagulant activities. The results relate structural features to activity, assisting the development of new and improved therapeutic agents, based on depolymerised heparin, for the prophylaxis and treatment of thrombotic disorders.

  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. 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

  13. [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

  14. 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

  15. 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

  16. 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.

  17. Participation of Low Molecular Weight Electron Carriers in Oxidative Protein Folding

    PubMed Central

    Margittai, Éva; Csala, Miklós; Mandl, József; Bánhegyi, Gábor

    2009-01-01

    Oxidative protein folding is mediated by a proteinaceous electron relay system, in which the concerted action of protein disulfide isomerase and Ero1 delivers the electrons from thiol groups to the final acceptor. Oxygen appears to be the final oxidant in aerobic living organisms, although the existence of alternative electron acceptors, e.g. fumarate or nitrate, cannot be excluded. Whilst the protein components of the system are well-known, less attention has been turned to the role of low molecular weight electron carriers in the process. The function of ascorbate, tocopherol and vitamin K has been raised recently. In vitro and in vivo evidence suggests that these redox-active compounds can contribute to the functioning of oxidative folding. This review focuses on the participation of small molecular weight redox compounds in oxidative protein folding. PMID:19399252

  18. 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

  19. 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.

  20. Computational and experimental investigation of DNA repair protein photolyase interactions with low molecular weight drugs.

    PubMed

    Azizoğlu, Selimcan; Kizilel, Riza; Marušič, Maja; Kavakli, Ibrahim Halil; Erman, Burak; Kizilel, Seda

    2013-07-01

    This paper reports the previously unknown interactions between eight low molecular weight commercially available drugs (130-800 Da) and DNA repair protein photolyase using computational docking simulations and surface plasmon resonance (SPR) experiments. Theoretical dissociation constants, K(d), obtained from molecular docking simulations were compared with the values found from SPR experiments. Among the eight drugs analyzed, computational and experimental values showed similar binding affinities between selected drug and protein pairs. We found no significant differences in binding interactions between pure and commercial forms of the drug lornoxicam and DNA photolyase. Among the eight drugs studied, prednisone, desloratadine, and azelastine exhibited the highest binding affinity (K(d) = 1.65, 2.05, and 8.47 μM, respectively) toward DNA photolyase. Results obtained in this study are promising for use in the prediction of unknown interactions of common drugs with specific proteins such as human clock protein cryptochrome. PMID:23657985

  1. Inhibition of protein-protein interactions with low molecular weight compounds

    PubMed Central

    Matthews, Marilyn M.; Weber, David J.; Shapiro, Paul S.; Coop, Andrew; MacKerell, Alexander D.

    2010-01-01

    An overview of issues associated with the design and development of low molecular weight inhibitors of protein-protein interactions is presented. Areas discussed include information on the nature of protein-protein interfaces, methods to characterize those interfaces and methods by which that information is applied towards ligand identification and design. Specific examples of the strategy for the identification of inhibitors of protein-protein interactions involving the proteins p56lck kinase, ERK2 and the calcium-binding protein S100B are presented. Physical characterization of the inhibitors identified in those studies shows them to have drug-like and lead-like properties, indicating their potential to be developed into therapeutic agents. PMID:21927717

  2. Absorption and effectiveness of orally administered low molecular weight collagen hydrolysate in rats.

    PubMed

    Watanabe-Kamiyama, Mari; Shimizu, Muneshige; Kamiyama, Shin; Taguchi, Yasuki; Sone, Hideyuki; Morimatsu, Fumiki; Shirakawa, Hitoshi; Furukawa, Yuji; Komai, Michio

    2010-01-27

    Collagen, a major extracellular matrix macromolecule, is widely used for biomedical purposes. We investigated the absorption mechanism of low molecular weight collagen hydrolysate (LMW-CH) and its effects on osteoporosis in rats. When administered to Wistar rats with either [(14)C]proline (Pro group) or glycyl-[(14)C]prolyl-hydroxyproline (CTp group), LMW-CH rapidly increased plasma radioactivity. LMW-CH was absorbed into the blood of Wistar rats in the peptide form. Glycyl-prolyl-hydroxyproline tripeptide remained in the plasma and accumulated in the kidney. In both groups, radioactivity was retained at a high level in the skin until 14 days after administration. Additionally, the administration of LMW-CH to ovariectomized stroke-prone spontaneously hypertensive rats increased the organic substance content and decreased the water content of the left femur. Our findings show that LMW-CH exerts a beneficial effect on osteoporosis by increasing the organic substance content of bone.

  3. Low molecular weight carbohydrates in pine nuts from Pinus pinea L.

    PubMed

    Ruiz-Aceituno, L; Ramos, L; Martinez-Castro, I; Sanz, M L

    2012-05-16

    Low molecular weight carbohydrates in pine nuts from Pinus pinea L. (n = 7) have been studied by gas chromatography-mass spectrometry as their trimethylsilyl oximes. Besides previously reported components, such as glucose, fructose, sucrose, and raffinose, several soluble carbohydrates have been identified for the first time in this product, including saccharides (galactose, maltose, and planteose) and cyclitols (pinitol, galactinol, galactopinitol A1, fagopyritol B1, and other glycosyl-inositols). Most abundant cyclitols were chiro-inositol, fagopyritol B1, and pinitol, with concentrations ranging from 126.7 to 222.1 mg (100 g)(-1), 94.2 to 177.1 mg (100 g)(-1), and 51.2 to 282.8 mg (100 g)(-1), respectively.

  4. Characterization and Immunological Evaluation of Low-Molecular- Weight Alginate Derivatives.

    PubMed

    Xu, Xu; Bi, Decheng; Wan, Min

    2016-01-01

    Alginate is a naturally occurring acidic linear polysaccharide obtained from marine brown seaweed. Low molecular weight structurally diverse derivatives and oligosaccharides derived from alginate have shown various tremendous biological and pharmacological activities. It has been demonstrated that immuno-inflammation is involved in many prevalent human diseases, such as cancer, severe infection and neurodegeneration. Given the activities of marine natural products in the regulation of immune responses, increasing efforts are being made toward the development of lowmolecular- weight natural compounds that aid in the prevention and treatment of immune- and inflammatory-related diseases. In this review, we describe the development of chemical modification and molecular depolymerization methods that modify the physicochemical and biological characteristics of alginate. Additionally, current progress in research on immuno-inflammatory, anti-neurodegenerative and anti-tumor activities of alginate derivatives is highlighted.

  5. Characterization of fatty acid liposome coated with low-molecular-weight chitosan.

    PubMed

    Tan, Hsiao Wei; Misran, Misni

    2012-12-01

    Preparation of chitosan-coated fatty acid liposomes is often restricted by the solubility of chitosan under basic conditions. In this experiment, the preparation of chitosan-coated oleic acid (OA) liposomes using low molecular weight (LMW) chitosan (10 and 25 kDA) was demonstrated. These selected LMW chitosans are water soluble. The coating of the chitosan layer on OA liposomes was confirmed by its microscope images and physicochemical properties, such as zeta potential and the size of the liposomes. The "peeling off" effect on the surface of chitosan-coated OA liposomes was observed in the atomic force microscope images and showed the occurrence of the chitosan layer on the surface of OA liposomes. The size of the chitosan-coated liposomes was at least 20 nm smaller than the OA liposomes, and the increase of zeta potential with the increasing amount of LMW chitosan further confirmed the presence of the surface modification of OA liposomes.

  6. 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.

  7. 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.

  8. 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.

  9. Low-molecular weight metalloproteins in tissues of the narwhal (Monodon monoceros).

    PubMed

    Wagemann, R; Hobden, B

    1986-01-01

    Narwhal (Monodon monoceros) liver and kidney cytosol were fractionated by gel chromatography, anion-exchange chromatography and electrophoresis. Cadmium was associated largely with low molecular weight proteins, while mercury was associated also with high molecular weight proteins, but apparently not because of saturation of the metallothionein mechanism. Eight different electrophoretic bands, four of which were metalloproteins, were found under the "metallothionein" peak. Anion-exchange chromatography yielded five metal peaks while further fractionation on G-50 gave two peaks, one containing almost pure metallothionein (Mt-1) and the other a metalloprotein having twice the molecular weight of metallothionein. Mt-2 was observed, at a much lower concentration than Mt-1, in liver but not kidney. PMID:2874949

  10. Effect of soil sieving on respiration induced by low-molecular-weight substrates

    NASA Astrophysics Data System (ADS)

    Datta, Rahul; Vranová, Valerie; Pavelka, Marian; Rejšek, Klement; Formánek, Pavel

    2014-03-01

    The mesh size of sieves has a significant impact upon soil disturbance, affecting pore structure, fungal hyphae, proportion of fungi to bacteria, and organic matter fractions. The effects are dependent upon soil type and plant coverage. Sieving through a 2 mm mesh increases mineralization of exogenously supplied carbohydrates and phenolics compared to a 5 mm mesh and the effect is significant (p<0.05), especially in organic horizons, due to increased microbial metabolism and alteration of other soil properties. Finer mesh size particularly increases arabinose, mannose, galactose, ferulic and pthalic acid metabolism, whereas maltose mineralization is less affected. Sieving through a 5 mm mesh size is suggested for all type of experiments where enhanced mineralization of low-molecular-weight organic compounds needs to be minimalized.

  11. Formation mechanism of monodisperse, low molecular weight chitosan nanoparticles by ionic gelation technique.

    PubMed

    Fan, Wen; Yan, Wei; Xu, Zushun; Ni, Hong

    2012-02-01

    Chitosan nanoparticles have been extensively studied for drug and gene delivery. In this paper, monodisperse, low molecular weight (LMW) chitosan nanoparticles were prepared by a novel method based on ionic gelation using sodium tripolyphosphate (TPP) as cross-linking agent. The objective of this study was to solve the problem of preparation of chitosan/TPP nanoparticles with high degree of monodispersity and stability, and investigate the effect of various parameters on the formation of LMW chitosan/TPP nanoparticles. It was found that the particle size distribution of the nanoparticles could be significantly narrowed by a combination of decreasing the concentration of acetic acid and reducing the ambient temperature during cross-linking process. The optimized nanoparticles exhibited a mean hydrodynamic diameter of 138 nm with a polydispersity index (PDI) of 0.026 and a zeta potential of +35 mV, the nanoparticles had good storage stability at room temperature up to at least 20 days.

  12. 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

  13. Low-molecular-weight heparin in the treatment of deep venous thrombosis.

    PubMed Central

    Hauer, K E

    1998-01-01

    Traditionally, acute deep venous thrombosis (DVT) is treated with intravenous heparin followed by oral anticoagulants. With the advent of the low-molecular-weight heparins (LMWHs), this strategy is changing dramatically. LMWHs are compounds derived from standard unfractionated heparin that offer distinct clinical advantages over unfractionated heparin, including better bioavailability, longer half-life, and a more predictable anticoagulant response that obviates the need for laboratory monitoring. The common side effects of unfractionated heparin, including bleeding, thrombocytopenia, and osteoporosis, may be less common with LMWH. For the treatment of established venous thromboembolism, LMWH is at least as safe and effective as unfractionated heparin. Recent studies demonstrate that home therapy of DVT with LMWH, compared with inpatient therapy with unfractionated heparin, produces comparable clinical outcomes and patient satisfaction, with dramatic cost savings. With careful patient selection, home therapy of venous thromboembolism is quickly becoming the new standard of care. PMID:9795594

  14. 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

  15. Effects of a supersulfated low molecular weight heparin (IK-SSH) on different hemostatic parameters.

    PubMed

    Glusa, E; Barthel, W; Schenk, J; Radziwon, P; Butti, A; Markwardt, F; Breddin, K H

    1998-01-01

    In a phase I trial effects of a new supersulfated low molecular weight heparin (IK-SSH) on different hemostatic parameters were investigated in healthy volunteers. Parameters studied were activated partial thromboplastin time (aPTT), thrombin time, Heptest, anti-activated factor II (anti-FIIa) and anti-activated factor X (anti-FXa) activity, platelet adhesion, platelet count, platelet-induced thrombin generation time (PITT), bleeding time, antithrombin III, fibrinogen and several safety parameters. After single intravenous (i.v.) injections of IK-SSH (0.14, 0.33 and 0.66 mg/kg) aPTT, Heptest and PITT were strongly and dose-dependently prolonged. After ascending subcutaneous (s.c.) doses of IK-SSH (0.33, 0.66 and 1 mg/kg) aPTT, Heptest and PITT were prolonged in a dose-dependent manner. Repeat s.c. injections of 1 mg/kg IK-SSH for 5 days markedly prolonged aPTT, Heptest and PITT. No cumulative effects were observed. Anti-FIIa and anti-FXa activity were not or only slightly increased. Bleeding time, thrombin time and platelet adhesion were not significantly changed after i.v. and s.c. injections of IK-SSH. However, tissue factor pathway inhibitor (TFPI) concentration was markedly increased after each injection of IK-SSH and returned to the preinjection value 24 h later. IK-SSH prolongs aPTT, Heptest and PITT in a similar manner as other low molecular weight heparins but without significantly affecting thrombin time, FIIa and FXa activity. The release of TFPI may well be responsible for the prolongation of aPTT, Heptest and PITT. IK-SSH may be further developed as an antithrombotic agent.

  16. Low-molecular-weight sulfonates, a major substrate for sulfate reducers in marine microbial mats.

    PubMed

    Visscher, P T; Gritzer, R F; Leadbetter, E R

    1999-08-01

    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 microM HS(-) h(-1) in a stromatolite mat, 38 and 36 microM HS(-) h(-1) in a salt pond mat, and 27 and 18 microM 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

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

    PubMed

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

    2012-10-01

    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 59 proteins 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

  18. Eczematous plaques related to unfractionated and low-molecular-weight heparin in pregnancy: cross-reaction with danaparoid sodium.

    PubMed

    Blickstein, Dorith; Hod, Moshe; Bar, Jacob

    2003-12-01

    The use of low-molecular-weight heparin has been expanded to prevent pregnancy complications such as pregnancy loss, intra-uterine growth restriction and severe early-onset pre-eclampsia in high-risk patients with evidence of acquired or congenital thrombophilia. Therefore, the number of patients with side effects from low-molecular-weight heparin is expected to increase. We describe two women with infiltrating patchy plaques that developed in reaction to low-molecular-weight heparin during pregnancy. In the first patient, a switch to other formulations of heparin and heparinoid failed; the second patient, however, did well when enoxaparin was replaced with dalteparin. This report confirms the risk of skin reactions to enoxaparin and dalteparin, and reports on a skin reaction associated with danaparoid sodium in a pregnant woman. PMID:14614358

  19. [Implementing ambulatory prevention of thrombosis with low molecular weight heparin in plaster immobilization of the lower extremity].

    PubMed

    Kock, H J; Schmit-Neuerburg, K P; Hanke, J; Terwort, A; Rudofsky, G; Hirche, H

    1994-12-01

    Plaster cast immobilisation following trauma is a major risk factor for the development of deep vein thrombosis. In our controlled, randomized and prospective study in patients with minor injuries the incidence of deep vein thrombosis was 4.3% in conservatively treated outpatients with plaster cast immobilisation of the leg (n = 163 control group without prophylaxis). By application of low molecular weight heparin once daily the number of deep vein thrombosis in the prophylaxis group (n = 176) was reduced to 0% (p = 0.006). No severe side effects of low molecular weight heparin were observed. Subcutaneous injections were self-applicated by 89% of males and 72% of females. We conclude that thromboprophylaxis with low molecular weight heparin once daily is effective to reduce the risk of deep vein thrombosis in outpatients with plaster cast immobilisation of the leg.

  20. A microfluidic approach for high efficiency extraction of low molecular weight RNA.

    PubMed

    Vulto, Paul; Dame, Gregory; Maier, Urban; Makohliso, Solomzi; Podszun, Susann; Zahn, Peter; Urban, Gerald A

    2010-03-01

    The lack of sample pre-treatment concepts that are easily automatable, miniaturized and highly efficient for both small volumes and low target concentrations, is one of the key issues that block the road towards effective miniaturized diagnostic instruments. This paper presents a novel, highly efficient and simple method for low-molecular weight RNA extraction using electricity only. Cells are lysed by thermo-electric lysis and RNA is purified using a gel-electrophoretic purification step. The combination of the two steps in one integrated cartridge reduces the time frame between the two steps, thus protecting RNA from enzymatic degradation. A disposable chip solution is proposed using a novel dry film resist laminate technology that allows cheap, large-scale fabrication. The chip contains crucial microfluidic innovations that allow for a simple user interface, reproducible functioning and precise quantification. Phaseguides are invented that allow controlled spatial injection of gel, injection of sample and recovery of extracted RNA. A precise sample volume can be defined by integrating electrophoretic actuation electrodes in the microfluidic chamber. Electrolytic gas bubbles that are the result of constant-current actuation are driven out from the chip by the novel introduction of capillary bubble-expulsion techniques. The extraction approach and the functionality of the chip are demonstrated for Escherichia coli and Streptococcus thermophilus bacteria. Linear extraction behavior is obtained for transfer-messenger RNA down to one colony-forming unit per microlitre, or five colony-forming units per chip. The latter is an increase in extraction efficiency of a factor of 1000 with respect to the commercial extraction kit Ambion Ribopure. The chip shows particularly good performance for extraction of low-molecular weight RNA, thereby eliminating the need for large ribosomal RNA and DNA removal. RNA can be extracted in less than 11 min, being a speed-up of more than a

  1. 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

  2. Low Molecular Weight Hydrocarbon Production at the Lost City Hydrothermal Field

    NASA Astrophysics Data System (ADS)

    Proskurowski, G.; Lilley, M.; Olson, E.; Kelley, D.; Frueh-Green, G.

    2005-12-01

    Here we present concentration, and stable and radiocarbon isotope data from hydrocarbons dissolved in hydrogen-rich fluids venting at the ultramafic-hosted Lost City Hydrothermal Field. The cool (<90°C) fluids venting from the spectacular carbonate chimneys at Lost City contain abundant low molecular weight hydrocarbons. A log-linear relationship (Schulz-Flory distriubution) between methane (mmol/kg), ethane (?mol/kg), propane (?mol/kg), and butane (nmol/kg) concentrations indicates synchronous production that is compatible with abiogenic formation such as Fischer-Tropsch type (FTT) genesis. However, a Schulz-Flory distribution of low-molecular weight hydrocarbons is commonly observed in the formation of petroleum via the pyrolysis of organic matter. Radiocarbon isotopic evidence suggests that the carbon source to Lost City hydrocarbons is carbon found in the host rocks, with no contribution from seawater bicarbonate. The underlying ultramafic host rocks contain <600 ppm non-carbonate carbon, most likely as a graphite found along grain boundaries, however a macro-molecular organic carbon source has not been eliminated (Delacour et al., 2004). While the absence of a large organic matter source argues for an abiogenic formation mechanism, a thermogenic source cannot yet be completely ruled out. The forthcoming carbon and hydrogen stable isotope analysis of Lost City hydrocarbons is expected to shed light on the formation mechanism. Both abiogenic FTT reactions and thermogenic formation imprint distinctive trends in the carbon isotopes of C1-C4 alkanes (Sherwood Lollar et al., 2002). Our initial findings, pending isotopic confirmation, illustrate the simple minimum requirements for extensive hydrocarbon production in nature: ultramafic rocks and water. Delacour, A. et al., 2004. Fluid-Rock Interaction in the Basement of the Lost City Vent Field: Insights from Stable and Radiogenic Isotopes. Eos, Transactions, American Geophysical Union, 85(47): Abstract B13A-0198

  3. 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

  4. 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

  5. Anticancer activity of chemically prepared shrimp low molecular weight chitin evaluation with the human monocyte leukaemia cell line, THP-1.

    PubMed

    Salah, R; Michaud, P; Mati, F; Harrat, Z; Lounici, H; Abdi, N; Drouiche, N; Mameri, N

    2013-01-01

    In the present study, anticancer activities of chitin, chitosan and low molecular weight chitin were evaluated using a human tumour cell line, THP-1. A molecular weight-activity relationship and an electrostatic interaction-activity relationship were determined. The cytotoxic effects of chitin and derivatives were also evaluated using a normal human foetal lung fibroblastic cell line, MRC-5 and the specific cytotoxicity of chitin and derivatives to tumour cell lines was demonstrated. The high antitumour effect of low molecular weight of chitin was established.

  6. Low molecular weight inhibitors of Myc-Max interaction and function.

    PubMed

    Yin, Xiaoying; Giap, Christine; Lazo, John S; Prochownik, Edward V

    2003-09-18

    c-Myc is helix-loop-helix-leucine zipper (HLH-ZIP) oncoprotein that is frequently deregulated in human cancers. In order to bind DNA, regulate target gene expression, and function in a biological context, c-Myc must dimerize with another HLH-ZIP protein, Max. A large number of c-Myc target genes have been identified, and many of the encoded proteins are transforming. Such functional redundancy, however, complicates therapeutic strategies aimed at inhibiting any single target gene product. Given this consideration, we have instead attempted to identify ways by which c-Myc itself could be effectively disabled. We have used a yeast two-hybrid approach to identify low-molecular-weight compounds that inhibit c-Myc-Max association. All of the compounds prevented transactivation by c-Myc-Max heterodimers, inhibited cell cycle progression, and prevented the in vitro growth of fibroblasts in a c-Myc-dependent manner. Several of the compounds also inhibited tumor growth in vivo. These results show that the yeast two-hybrid screen is useful for identifying compounds that can be exploited in mammalian cells. More specifically, they provide a means by which structural analogs, based upon these first-generation Myc-Max inhibitors, can be developed to enhance antitumor efficacy.

  7. 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

  8. 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.

  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. 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

  11. 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

  12. 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

  13. Low molecular weight heparin (enoxaparin) reverses pregangrene in a preterm neonate.

    PubMed

    Gohil, Jayendra R; Solanki, Dhaval I; Vaghjiyani, Lalji

    2009-01-01

    A 34-week-old, 1.6 kg preterm boy was admitted for management of mild respiratory distress syndrome. On the third day of life 1 min after an intravenous cannulation attempt at the right cubital fossa, he developed pregangrene bluish discoloration of all fingertips up to the distal interphalangial joint and pallor of right palm. Pulsations on right forearm were reduced. There was no evidence of sepsis.Enoxaparin, a low molecular weight heparin (1.5 mg/kg (standard dose)) was injected subcutaneously in the abdomen in two doses 12 h apart within 2 h of the event. At 6 h after the first dose, brachial artery pulsation was bilaterally symmetrical. After the second dose, bilateral radial artery pulsation became symmetrical. The pregangrene changes returned to normal within 20 h as the distal phalanges became pink and warm. He was discharged on the eighth day of life. Enoxaparin was safe and effective in this preterm infant for reversal of pregangrene.

  14. Patient compliance with extended low molecular weight heparin injections following hip and knee arthroplasty.

    PubMed

    Deakin, Dan E; Mishreki, Andrew; Aslam, Nadim; Docker, Charles

    2010-01-01

    The use of extended duration thromboprophylaxis following hip and knee arthroplasty is becoming widespread. The aim of our study was to determine patient compliance with extended duration thromboprophylaxis using low molecular weight (LMWH) injections following hip and knee arthroplasty. 42 consecutive patients undergoing hip and knee arthroplasty were prospectively contacted during their fifth post operative week. A fully anonymised questionnaire was completed by each patient. All patients responded. One was excluded having been prescribed warfarin for pre existing atrial fibrillation. Twenty nine (71%) patients were discharged with the intention of self administering LMWH injections. Eight (20%) and four (9%) patients were discharged with the intention of administration by a relative or district nurse respectively. No patient required the person administering the injections to be changed after discharge from hospital. 90% (n=37) of patients reported not missing any doses. 10% (n=2) of patients missed one dose and 10% (n=2) missed two doses. Patient compliance with extended duration thromboprophylaxis using LMWH injections is extremely high. Oral thromboprophylaxis may be useful in the minority of patients requiring daily visits by a nurse to administer injections.

  15. Low molecular weight heparin improves healing of chronic venous ulcers especially in the elderly.

    PubMed

    Serra, Raffaele; Buffone, Gianluca; Molinari, Vincenzo; Montemurro, Rossella; Perri, Paolo; Stillitano, Domenico M; Amato, Bruno; de Franciscis, Stefano

    2015-04-01

    Venous ulcers are common, especially in the elderly, accounting for more than 50% of all lower extremity ulcers with important socioeconomic problems. Improving extracellular matrix functioning, by heparin administration, seems to be a way to support wound healing. A total of 284 patients with venous ulcers were recruited in a 4-year period. All patients were subjected to the most appropriate treatment after considering their preference (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 142 persons in each (group A and group B as cases and controls, respectively). Patients of group A, in addition to the basic treatment as described earlier, received administration of nadroparin 2850 IU/0.3 ml through subcutaneous injection once a day for 12 months, whereas group B patients received basic treatment alone. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a healing rate of 83·80% at 12 months, whereas that of group B was 60·56%. Results by age group surprisingly showed that the group of older patients took the most advantage from long-term treatment with low molecular weight heparin; this group also had lowest recurrence rate.

  16. Molecular imprinted polymer-coated optical fiber sensor for the identification of low molecular weight molecules.

    PubMed

    Lépinay, Sandrine; Ianoul, Anatoli; Albert, Jacques

    2014-10-01

    A biomimetic optical probe for detecting low molecular weight molecules (maltol, 3-hydroxy-2-methyl-4H-pyran-4-one, molecular weight of 126.11 g/mol), was designed, fabricated, and characterized. The sensor couples a molecular imprinted polymer (MIP) and the Bragg grating refractometry technology into an optical fiber. The probe is fabricated first by inscribing tilted grating planes in the core of the fiber, and then by photopolymerization to immobilize a maltol imprinted MIP on the fiber cladding surface over the Bragg grating. The sensor response to the presence of maltol in different media is obtained by spectral interrogation of the fiber transmission signal. The results showed that the limit of detection of the sensor reached 1 ng/mL in pure water with a sensitivity of 6.3 × 10(8)pm/M. The selectivity of the sensor against other compounds and its reusability were also studied experimentally. Finally, the unambiguous detection of concentrations as little as 10nM of maltol in complex media (real food samples) by the MIP-coated tilted fiber Bragg grating sensor was demonstrated.

  17. 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

  18. Immunostimulative Activity of Low Molecular Weight Chitosans in RAW264.7 Macrophages

    PubMed Central

    Wu, Ning; Wen, Zheng-Shun; Xiang, Xing-Wei; Huang, Yan-Na; Gao, Yang; Qu, You-Le

    2015-01-01

    Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been reported to exert many biological activities, such as antioxidant and antitumor effects. However, complex and molecular weight dependent effects of chitosan remain controversial and the mechanisms that mediate these complex effects are still poorly defined. This study was carried out to investigate the immunostimulative effect of different molecular weight chitosan in RAW264.7 macrophages. Our data suggested that two LMWCs (molecular weight of 3 kDa and 50 kDa) both possessed immunostimulative activity, which was dependent on dose and, at the higher doses, also on the molecular weight. LMWCs could significantly enhance the the pinocytic activity, and induce the production of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon-γ (IFN-γ), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in a molecular weight and concentration-dependent manner. LMWCs were further showed to promote the expression of the genes including iNOS, TNF-α. Taken together, our findings suggested that LMWCs elicited significantly immunomodulatory response through up-regulating mRNA expression of proinflammatory cytokines and activated RAW264.7 macrophage in a molecular weight- and concentration-dependent manner. PMID:26437419

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Comparative study of the physicochemical properties of six clinical low molecular weight gadolinium contrast agents.

    PubMed

    Laurent, Sophie; Elst, Luce Vander; Muller, Robert N

    2006-01-01

    This paper compares the physicochemical properties of six low molecular weight clinical complexes of gadolinium studied under identical experimental conditions. Magnevist, Dotarem, Omniscan, ProHance, MultiHance and Gadovist were investigated by oxygen-17 relaxometry at different temperatures and by proton relaxometry at various magnetic fields, temperatures and media [pure water, zinc(II)-containing aqueous solutions and HSA-containing solutions]. Osmolality, viscosity and stability versus transmetallation by zinc(II) ions were added for a more comprehensive description. The relaxivities of the clinical formulations as measured in water are similar in the imaging magnetic field region, with a slightly better performance for MultiHance. This can be explained by a shorter distance between the hydrogen nuclei of the water molecule bound to the Gd(3+) ion and this paramagnetic centre. In contrast to the open-chain complexes, all macrocyclic systems (Dotarem, ProHance and Gadovist) are insensitive to transmetallation by zinc ions. The stability of the open-chain complexes with respect to transmetallation depends on the chemical structure of the ligand, with a better stability for MultiHance. The presence of human serum albumin has no significant effect on the proton relaxivity of Magnevist, Dotarem, Omniscan, ProHance and Gadovist but markedly increases the relaxivity of MultiHance because of a non-covalent interaction with the protein. As a result, the relaxivity of MultiHance in HSA-containing media of fixed concentration decreases with increasing concentration of the contrast agent.

  4. 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).

  5. Interactions of nano-oxides with low-molecular-weight organic acids in a contaminated soil.

    PubMed

    Vítková, Martina; Komárek, Michael; Tejnecký, Václav; Šillerová, Hana

    2015-08-15

    Various low-molecular-weight organic acids (LMWOAs) play an important role in the mobilisation of contaminants and their subsequent uptake by plants. Nano-maghemite (NM) and an amorphous Mn oxide (AMO) were investigated for their stabilisation potential under simulated rhizosphere conditions in terms of their use during chemical stabilisation and aided phytostabilisation of metal(loid)s in contaminated soils. In order to understand the reactivity of these potential sorbents of contaminants in soils and subsequent mobility of metal(loid)s, a set of time-dependent batch leaching experiments was performed using a mix of acetic, lactic, citric, malic and formic acids simulating root exudates. Despite being relatively unstable under given conditions, the AMO proved to be an efficient amendment for rapid stabilisation of both metals and As compared to NM. Generally, low pH (∼ 4) and the presence of citrate complexes resulted in higher mobility of metals in the non- and NM-amended soil. In contrast, the presence of AMO in the soil accelerated the neutralisation reactions related to pH increase and (co-) precipitation of secondary Fe/Mn/Al oxyhydroxides. Mineralogical transformations of the AMO showed to be crucial for contaminant immobilisation. PMID:25814334

  6. Positively charged polyethylenimines enhance nasal absorption of the negatively charged drug, low molecular weight heparin.

    PubMed

    Yang, Tianzhi; Hussain, Alamdar; Bai, Shuhua; Khalil, Ikramy A; Harashima, Hideyoshi; Ahsan, Fakhrul

    2006-10-27

    This study tests the hypothesis that positively charged polyethylenimines (PEIs) enhance nasal absorption of low molecular weight heparin (LMWH) by reducing the negative surface charge of the drug molecule. Physical interactions between PEIs and LMWH were studied by Fourier transform infrared (FTIR) spectroscopy, particle size analysis, conductivity measurements, zeta potential analysis, and azure A assay. The efficacy of PEIs in enhancing nasal absorption of LMWH was studied by administering LMWH formulated with PEI into the nose of anesthetized rats and monitoring drug absorption by measuring plasma anti-factor Xa activity. The metabolic stability of LMWH was evaluated by incubating the drug in rat nasal mucosal homogenates. FTIR spectra of the LMWH-PEI formulation showed a shift in peak position compared to LMWH or PEI alone. Decreases in conductivity, zeta potential and the amount of free LMWH in the PEI-LMWH formulation, as revealed by azure A assay, suggest that PEIs possibly neutralize the negative surface charge of LMWH. The efficacy of PEI in enhancing the bioavailability of nasally administered LMWH can be ranked as PEI-1000 kDa>or=PEI-750 kDa>PEI-25 kDa. When PEI-1000 kDa was used at a concentration of 0.25%, there was a 4-fold increase in both the absolute and relative bioavailabilities of LMWH compared to the control formulation. Overall, these results indicate that polyethylenimines can be used as potential carriers for nasally administered LMWHs. PMID:17023085

  7. 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.

  8. 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.

  9. The high and low molecular weight forms of hyaluronan have distinct effects on CD44 clustering.

    PubMed

    Yang, Cuixia; Cao, Manlin; Liu, Hua; He, Yiqing; Xu, Jing; Du, Yan; Liu, Yiwen; Wang, Wenjuan; Cui, Lian; Hu, Jiajie; Gao, Feng

    2012-12-14

    CD44 is a major cell surface receptor for the glycosaminoglycan hyaluronan (HA). Native high molecular weight hyaluronan (nHA) and oligosaccharides of hyaluronan (oHA) provoke distinct biological effects upon binding to CD44. Despite the importance of such interactions, however, the feature of binding with CD44 at the cell surface and the molecular basis for functional distinction between different sizes of HA is still unclear. In this study we investigated the effects of high and low molecular weight hyaluronan on CD44 clustering. For the first time, we provided direct evidence for a strong relationship between HA size and CD44 clustering in vivo. In CD44-transfected COS-7 cells, we showed that exogenous nHA stimulated CD44 clustering, which was disrupted by oHA. Moreover, naturally expressed CD44 was distributed into clusters due to abundantly expressed nHA in HK-2 cells (human renal proximal tubule cells) and BT549 cells (human breast cancer cell line) without exogenous stimulation. Our results suggest that native HA binding to CD44 selectively induces CD44 clustering, which could be inhibited by oHA. Finally, we demonstrated that HA regulates cell adhesion in a manner specifically dependent on its size. oHA promoted cell adhesion while nHA showed no effects. Our results might elucidate a molecular- and/or cellular-based mechanism for the diverse biological activities of nHA and oHA.

  10. Low-molecular-weight polyethylenimine enhanced gene transfer by cationic cholesterol-based nanoparticle vector.

    PubMed

    Hattori, Yoshiyuki; Maitani, Yoshie

    2007-09-01

    Both polyethylenimine (PEI) polymers and cationic nanoparticles have been widely used for non-viral DNA transfection. Previously, we reported that cationic nanoparticles composed of cholesteryl-3beta-carboxyamidoethylene-N-hydroxyethylamine and Tween 80 (NP-OH) could deliver plasmid DNA (pDNA) with high transfection efficiency. To increase the transfection activity of NP-OH, we investigated the potential synergism of PEI and NP-OH for the transfection of DNA into human prostate tumor PC-3, human cervices tumor Hela, and human lung adenocarcinoma A549 cells. The transfection efficiency with low-molecular PEI (MW 600) was low, but that with a combination of NP-OH and PEI was higher than with NP-OH alone, being comparable to commercially available lipofectamine 2,000 and lipofectamine LTX, with very low cytotoxicity. Low-molecular weight PEI could not compact pDNA in size, but rather might help to dissociate pDNA from the complex and release pDNA from the endosome to cytoplasm by the proton sponge effect. Therefore, the combination of cationic cholesterol-based nanoparticles and a low-molecular PEI has potential as a non-viral DNA vector for gene delivery.

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

    PubMed

    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.

  12. 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

  13. 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.

  14. 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

  15. [Effects of low molecular weight organic acids on redox reactions of mercury].

    PubMed

    Zhao, Shi-Bo; Sun, Rong-Guo; Wang, Ding-Yong; Wang, Xiao-Wen; Zhang, Cheng

    2014-06-01

    To study the effects of the main component of vegetation root exudates-low molecular weight organic acids on the redox reactions of mercury, laboratory experiments were conducted to investigate the roles of tartaric, citric, and succinic acid in the redox reactions of mercury, and to analyze their interaction mechanism. The results indicated that tartaric acid significantly stimulated the mercury reduction reaction, while citric acid had inhibitory effect. Succinic acid improved the reduction rate at low concentration, and inhibited the reaction at high concentration. The mercury reduction rate by tartaric acid treatment was second-order with respect to Hg2+ concentration, ranging from 0.0014 L x (ng x min)(-1) to 0.005 6 L x (ng x min)(-1). All three organic acids showed a capacity for oxidating Hg(0) in the early stage, but the oxidized Hg(0) was subsequently reduced. The oxidation capacity of the three organic acids was in the order of citric acid > tartaric acid > succinic acid.

  16. 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.

  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. Low-Molecular-Weight Metabolites Secreted by Paenibacillus larvae as Potential Virulence Factors of American Foulbrood

    PubMed Central

    Schild, Hedwig-Annabell; Fuchs, Sebastian W.

    2014-01-01

    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

  19. 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

  20. 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

  1. Partial characterization of a low molecular weight human collagen that undergoes alternative splicing

    SciTech Connect

    Pihlajaniemi, T.; Myllylea, R.; Kurkinen, M.; Prockop, D.J.

    1987-02-01

    A cDNA library prepared from RNA isolated from a cultured human tumor cell line, HT-1080, was screened with a mouse cDNA clone coding for part of the -Gly-Xaa-Yaa-domain of the ..cap alpha..2(IV) collagen chain. Four overlapping cDNA clones were characterized that coded for a low molecular weight human collagen. The cDNA clones did not, however, code for the short-chain collagens, types IX and X. The amino acid sequences derived from the clones resembled type IV collagen in that there were short interruptions in the repeating -Gly-Xaa-Yaa-sequence. The noncollagenous, carboxyl-terminal domain was, however, much shorter and contained only 18 amino acid residues. Interestingly, one of the cDNA clones contained an additional 36 nucleotides not found in an overlapping clone. The 36 nucleotides encoded four -Gly-Xaa-Yaa-repeats without changing the reading frame. Nuclease S1 mapping using a /sup 32/P-labelled probe demonstrated that the different between the clones was due to existence of two different mRNAs. A synthetic 24-residue peptide corresponding to the last two -Gly-Xaa-Yaa-triplets and the entire carboxyl-terminal domain was used to generate polyclonal antibodies. Electrophoretic transfer blot analysis of HT-1080 cells and normal human skin fibroblasts identified two polypeptides, M/sub r/ 67,000 and M/sub r/ 62,000, that were sensitive to bacterial collagenase.

  2. Low molecular weight fucoidan ameliorates diabetic nephropathy via inhibiting epithelial-mesenchymal transition and fibrotic processes

    PubMed Central

    Chen, Jihui; Cui, Wentong; Zhang, Quanbin; Jia, Yingli; Sun, Yi; Weng, Lin; luo, Dali; Zhou, Hong; Yang, Baoxue

    2015-01-01

    Diabetic nephropathy (DN) is one of the most serious microvascular complications of diabetes and may lead to end-stage renal disease (ESRD) and chronic renal failure. The aim of this study was to determine whether low-molecular-weight fucoidan (LMWF) can reduce harmful transforming growth factor-β (TGF-β)-mediated renal fibrosis in DN using in vitro and in vivo experimental models. The experimental results showed that LMWF significantly reversed TGF-β1-induced epithelial-mesenchymal transition and dose-dependently inhibited accumulation of extracellular matrix proteins, including connective tissue growth factor and fibronectin. It was found that LMWF significantly reduced blood urea nitrogen and blood creatinine in both type 1 and type 2 diabetic rat models. H&E, PAS and Masson’s trichrome staining of kidney tissue showed LMWF significantly reduced renal interstitial fibrosis. Treatment with LMWF significantly increased E-cadherin expression and reduced α-SMA, CTGF and fibronectin expression in both type 1 and type 2 diabetic models. LMWF also decreased the phosphorylation of Akt, ERK1/2, p38 and Smad3 in vitro and in vivo. These data suggest that LMWF may protect kidney from dysfunction and fibrogenesis by inhibiting TGF-β pathway and have the potential benefit to slow down the progression of DN. PMID:26550455

  3. 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

  4. 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

  5. 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.

  6. The enhancement of PCR amplification by low molecular-weight sulfones.

    PubMed

    Chakrabarti, R; Schutt, C E

    2001-08-22

    DNA amplification by polymerase chain reaction (PCR) is frequently complicated by the problems of low yield and specificity, especially when the GC content of the target sequence is high. A common approach to the optimization of such reactions is the addition of small quantities of certain organic chemicals, such as dimethylsulfoxide (DMSO), betaine, polyethylene glycol and formamide, to the reaction mixture. Even in the presence of such additives, however, the amplification of GC-rich templates is often ineffective. In this paper, we introduce a novel class of PCR-enhancing compounds, the low molecular-weight sulfones, that are effective in the optimization of high GC template amplification. We describe here the results of an extensive structure-activity investigation in which we studied the effects of a series of six different sulfones on PCR amplification. We identify two sulfones, sulfolane and methyl sulfone, that are especially potent enhancers of high GC template amplification, and show that these compounds often outperform DMSO and betaine, two of the most effective PCR enhancers currently used. We conclude with a brief discussion of the role that the sulfone functional group may play in such enhancement.

  7. Isolation and characterization of low molecular weight glycosaminoglycans from marine mollusc Amussium pleuronectus (linne) using chromatography.

    PubMed

    Saravanan, R; Shanmugam, A

    2010-03-01

    The glycosaminoglycan (GAG) heparin is a polyanionic sulfated polysaccharide most recognized for its anticoagulant activity. In the present study, the GAGs were extracted from bivalve mollusc Amussium pleuronectus. The crude GAGs were fractionated by ion-exchange (DEAE-cellulose and Amberlite IRA-900 & 120) chromatography. The recovered active fractions (as determined by metachromatic assay) were confirmed by agarose gel electrophoresis and the active fractions were purified in Sephadex G-100 column. Fractionated and purified GAG molecular weight was determined through gradient polyacrylamide gel electrophoresis. The structural characterization of low molecular weight GAG was analyzed by Fourier transform infrared spectroscopy. The activated partial thromboplastin time of purified GAG is 95 IU/mg and has molecular weight 6,500-7,500 Da. The disaccharide compositional analysis on the GAG sample was sulfated like porcine intestinal mucosal heparan sulfate, and it contains equivalent amount of uronic acid and hexosamine. The results of this study suggest that the GAG from A. pleuronectus could be an alternative source of heparin.

  8. 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.

  9. Molecular dynamics simulations on the interactions of low molecular weight natural organic acids with C60.

    PubMed

    Sun, Qian; Xie, Hong-Bin; Chen, Jingwen; Li, Xuehua; Wang, Zhuang; Sheng, Lianxi

    2013-07-01

    As an important part of dissolved organic matter (DOM), low molecular weight organic acids (LOAs) may play a key role in the process for DOM stabilizing carbon nanomaterials (e.g. C60) suspensions in aquatic environment. In addition, both LOAs and C60 have been detected in the troposphere and therefore have a chance to interact with each other in the gaseous phase. However, the mechanism for LOAs-C60 interactions and their environmental implications need further investigations. In this study, molecular dynamics (MD) simulation was employed to investigate the interactions between both neutral and ionic LOAs with C60 in vacuum and water. The results showed that the adsorptions of all LOAs on C60 in energy are favorable, and the aromatic acids have stronger interactions with C60 than the aliphatic acids in vacuum and water. The interaction energies (Eint) of the LOA anions with C60 were weaker than those of their corresponding neutral LOA molecules. The models were also developed to predict and interpret Eint based on the results from MD simulations. Dispersion, induction and hydrophobic interactions were found to be the dominating factor in Eint. These findings indicate that cost-efficient MD simulation can be employed as an important tool to predict the adsorption behavior of LOAs on carbon nanomaterials.

  10. Low-molecular-weight-chitosan ameliorates cadmium-induced toxicity in the freshwater crab, Sinopotamon yangtsekiense.

    PubMed

    Li, Ruijin; Zhou, Yanying; Wang, Lan; Ren, Guorui

    2011-07-01

    Cadmium (Cd) has been shown to induce oxidative stress. Low-molecular-weight-chitosan (LMWC) has been demonstrated to exhibit potent antioxidant effects. We investigated the regulation role in Cd²⁺-induced oxidative damage in the hepatopancreas of the freshwater crab Sinopotamon yangtsekiense and the protective effect of LMWC. The results showed that Cd²⁺ significantly increased the hepatopancreatic metallothionein (MT) mRNA levels and protein kinase C (PKC) activity while decreasing the activities of Na⁺,K⁺-ATPase and Ca²⁺-ATPase in crabs relative to the control group. Co-treatment with LMWC suppressed the levels of MT and PKC but raised the activities of Na⁺,K+-ATPase and Ca²⁺-ATPase in hepatopancreatic tissues compared with the crabs exposed to Cd²⁺ alone. We postulate that LMWC may exert its protective effect through regulating the expressions of MT, PKC, Na⁺,K⁺-ATPase and Ca²⁺-ATPase, thereby enhancing antioxidant defense. These observations suggest that LMWC may be beneficial because of its ability to alleviate the Cd²⁺-induced damages to the crabs.

  11. [Antibacterial effects of water-soluble low-molecular-weight chitosans on different microorganisms].

    PubMed

    Gerasimenko, D V; Avdienko, I D; Bannikova, G E; Zueva, O Iu; Varlamov, V P

    2004-01-01

    Low-molecular-weight chitosans with a viscosity-average molecular weight (Mv) of 5 to 27 kDa and equal degree of deacetylation (DD, 85%) were highly active against Pseudomonas aureofaciens, Enterobacter agglomerans, Bacillus subtilis, and Bifidobacterium bifidum 791, causing death of 80 to 100% of cells. An exception to this tendency was Escherichia coli, for which the rate of cell death, induced by the 5-kDa chitosan, was 38%. The antibacterial effect was manifested as early as 10 min after incubation of 12-kDa chitosan with B. subtilis or E. coli cells. Candida krusei was almost insensitive to the above crab chitosans. However, Candida krusei was highly sensitive to chitosans with Mv 5, 6, 12, 15.7, and 27 kDa: the minimum inhibitory concentration (MIC) varied from 0.06 to 0.005%. Chitosans with M, 5, 12, and 15.7 kDa exerted an antibacterial effect on Staphylococcus aureus. Chitosans with Mv 5, 15.7, and 27 kDa had no effect on Bifidobacterium bifidum ATCC 14893. The antibacterial effect of the 4-kDa chitosan on E. coli and B. bifidum 791 increased with DD in the range 55-85%.

  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.

  13. 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.

  14. Determination of aliphatic low-molecular-weight and biogenic amines by capillary zone electrophoresis.

    PubMed

    Fekete, Agnes; Lahaniatis, Majlinda; Lintelmann, Jutta; Schmitt-Kopplin, Philippe

    2008-01-01

    Low-molecular-weight (LMW) aliphatic amines play a key role in the global nitrogen cycle, are involved in nutrient transfer, and act as buffer in the ecosystem. They are widely used as intermediates in chemical synthesis and were shown to cause occupational asthma. Biogenic amines occur in all living organisms and have an effect on the cell growth, although at high concentrations they can be toxic; some are used as cancer markers in health protection or as spoilage markers in foods. Their identification and quantification from different matrices such as human tissues or foods is of high importance. The electrophoretic separation of amines is possible as cations as a result of their high basicity; their detection, however, is more difficult because these amines contain no chromophore group. Indirect ultraviolet (UV) detection is the first presented possibility and widely used for the separation of nonderivatized amines. Otherwise, derivatization of the amines is necessary to directly detect them with laser-induced fluorescence (LIF) detection. Other detection modes such as pulse amperometric, chemiluminescence, or mass spectrometry have been also used for the determination of LMW and biogenic amines, but not on a routine basis. In this chapter, three capillary electrophoretic methods with indirect UV and LIF detection for determination of LMW aliphatic and biogenic amines are described.

  15. 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

  16. 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

  17. 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

  18. 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

  19. A low-molecular-weight antagonist for the human thyrotropin receptor with therapeutic potential for hyperthyroidism.

    PubMed

    Neumann, Susanne; Kleinau, Gunnar; Costanzi, Stefano; Moore, Susanna; Jiang, Jian-kang; Raaka, Bruce M; Thomas, Craig J; Krause, Gerd; Gershengorn, Marvin C

    2008-12-01

    Low-molecular-weight (LMW) antagonists for TSH receptor (TSHR) may have therapeutic potential as orally active drugs to block stimulating antibodies (TsAbs) in Graves' hyperthyroidism. We describe an approach to identify LMW ligands for TSHR based on Org41841, a LMW partial agonist for the LH/choriogonadotropin receptor and TSHR. We used molecular modeling and functional experiments to guide the chemical modification of Org41841. We identified an antagonist (NIDDK/CEB-52) that selectively inhibits activation of TSHR by both TSH and TsAbs. Whereas initially characterized in cultured cells overexpressing TSHRs, the antagonist was also active under more physiologically relevant conditions in primary cultures of human thyrocytes expressing endogenous TSHRs in which it inhibited TSH- and TsAb-induced up-regulation of mRNA transcripts for thyroperoxidase. Our results establish this LMW compound as a lead for the development of higher potency antagonists and serve as proof of principle that LMW ligands that target TSHR could serve as drugs in patients with Graves' disease.

  20. Dipeptide-based low-molecular-weight efficient organogelators and their application in water purification.

    PubMed

    Debnath, Sisir; Shome, Anshupriya; Dutta, Sounak; Das, Prasanta Kumar

    2008-01-01

    The development of new low-molecular-weight gelators for organic solvents is motivated by several potential applications of gels as advanced functional materials. In the present study, we developed simple dipeptide-based organogelators with a minimum gelation concentration (MGC) of 6-0.15 %, w/v in aromatic solvents. The organogelators were synthesized using different L-amino acids with nonpolar aliphatic/aromatic residues and by varying alkyl-chain length (C-12 to C-16). The self-aggregation behavior of these thermoreversible organogels was investigated through several spectroscopic and microscopic techniques. A balanced participation of the hydrogen bonding and van der Waals interactions is crucial for efficient organogelation, which can be largely modulated by the structural modification at the hydrogen-bonding unit as well as by varying the alkyl-chain length in both sides of the hydrophilic residue. Interestingly, these organogelators could selectively gelate aromatic solvents from their mixtures with water. Furthermore, the xerogels prepared from the organogels showed a striking property of adsorbing dyes such as crystal violet, rhodamine 6G from water. This dye-adsorption ability of gelators can be utilized in water purification by removing toxic dyes from wastewater.

  1. Comprehensive Analysis of Low-Molecular-Weight Human Plasma Proteome Using Top-Down Mass Spectrometry.

    PubMed

    Cheon, Dong Huey; Nam, Eun Ji; Park, Kyu Hyung; Woo, Se Joon; Lee, Hye Jin; Kim, Hee Cheol; Yang, Eun Gyeong; Lee, Cheolju; Lee, Ji Eun

    2016-01-01

    While human plasma serves as a great source for disease diagnosis, low-molecular-weight (LMW) proteome (<30 kDa) has been shown to contain a rich source of diagnostic biomarkers. Here we employ top-down mass spectrometry to analyze the LMW proteoforms present in four types of human plasma samples pooled from three healthy controls (HCs) without immunoaffinity depletion and with depletion of the top two, six, and seven high-abundance proteins. The LMW proteoforms were first fractionated based on molecular weight using gel-eluted liquid fraction entrapment electrophoresis (GELFrEE). Then, the GELFrEE fractions containing up to 30 kDa were subjected to nanocapillary-LC-MS/MS, and the high-resolution MS and MS/MS data were processed using ProSightPC 3.0. As a result, a total of 442 LMW proteins and cleaved products, including those with post-translational modifications and single amino acid variations, were identified. From additional comparative analysis of plasma samples without immunoaffinity depletion between HCs and colorectal cancer (CRC) patients via top-down approach, tens of LMW proteoforms, including platelet factor 4, were found to show >1.5-fold changes between the plasma samples of HCs and CRC patients, and six of the LMW proteins were verified by Western blot analysis.

  2. Purification of a Low Molecular Weight Fucoidan for SPECT Molecular Imaging of Myocardial Infarction

    PubMed Central

    Saboural, Pierre; Chaubet, Frédéric; Rouzet, Francois; Al-Shoukr, Faisal; Ben Azzouna, Rana; Bouchemal, Nadia; Picton, Luc; Louedec, Liliane; Maire, Murielle; Rolland, Lydia; Potier, Guy; Le Guludec, Dominique; Letourneur, Didier; Chauvierre, Cédric

    2014-01-01

    Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with 99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome. PMID:25251032

  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. Activation of the low molecular weight protein tyrosine phosphatase in keratinocytes exposed to hyperosmotic stress.

    PubMed

    Silva, Rodrigo A; Palladino, Marcelly V; 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

  5. Immunostimulative Activity of Low Molecular Weight Chitosans in RAW264.7 Macrophages.

    PubMed

    Wu, Ning; Wen, Zheng-Shun; Xiang, Xing-Wei; Huang, Yan-Na; Gao, Yang; Qu, You-Le

    2015-09-30

    Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been reported to exert many biological activities, such as antioxidant and antitumor effects. However, complex and molecular weight dependent effects of chitosan remain controversial and the mechanisms that mediate these complex effects are still poorly defined. This study was carried out to investigate the immunostimulative effect of different molecular weight chitosan in RAW264.7 macrophages. Our data suggested that two LMWCs (molecular weight of 3 kDa and 50 kDa) both possessed immunostimulative activity, which was dependent on dose and, at the higher doses, also on the molecular weight. LMWCs could significantly enhance the the pinocytic activity, and induce the production of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon-γ (IFN-γ), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in a molecular weight and concentration-dependent manner. LMWCs were further showed to promote the expression of the genes including iNOS, TNF-α. Taken together, our findings suggested that LMWCs elicited significantly immunomodulatory response through up-regulating mRNA expression of proinflammatory cytokines and activated RAW264.7 macrophage in a molecular weight- and concentration-dependent manner.

  6. Structure and activity of a new low-molecular-weight heparin produced by enzymatic ultrafiltration.

    PubMed

    Fu, Li; Zhang, Fuming; Li, Guoyun; Onishi, Akihiro; Bhaskar, Ujjwal; Sun, Peilong; Linhardt, Robert J

    2014-05-01

    The standard process for preparing the low-molecular-weight heparin (LMWH) tinzaparin, through the partial enzymatic depolymerization of heparin, results in a reduced yield because of the formation of a high content of undesired disaccharides and tetrasaccharides. An enzymatic ultrafiltration reactor for LMWH preparation was developed to overcome this problem. The behavior, of the heparin oligosaccharides and polysaccharides using various membranes and conditions, was investigated to optimize this reactor. A novel product, LMWH-II, was produced from the controlled depolymerization of heparin using heparin lyase II in this optimized ultrafiltration reactor. Enzymatic ultrafiltration provides easy control and high yields (>80%) of LMWH-II. The molecular weight properties of LMWH-II were similar to other commercial LMWHs. The structure of LMWH-II closely matched heparin's core structural features. Most of the common process artifacts, present in many commercial LWMHs, were eliminated as demonstrated by 1D and 2D nuclear magnetic resonance spectroscopy. The antithrombin III and platelet factor-4 binding affinity of LMWH-II were comparable to commercial LMWHs, as was its in vitro anticoagulant activity.

  7. Effect of preparation parameters on ultra low molecular weight chitosan/hyaluronic acid nanoparticles.

    PubMed

    Nazeri, Niloofar; Avadi, Mohammad Reza; Faramarzi, Mohammad Ali; Safarian, Shahrokh; Tavoosidana, Gholamreza; Khoshayand, Mohammad Reza; Amani, Amir

    2013-11-01

    Nanoparticles of ultra low molecular weight chitosan (ULMWCS)/hyaluronic acid (HA) were prepared by ion gelation. Three independent variables, namely, ratio of concentration of ULMWCS to HA (CS/HA), pH of solution and stirring time were studied to identify their effects on size, polydispersity and zeta potential of prepared nanoparticles using a Box-Behnken design. Results showed that pH and CS/HA have a direct effect on size, while increase of stirring time decreases the size of nanoparticles. Additionally, it was shown that all the independent parameters have direct effects on zeta potential. Also, the minimum polydispersity index was observed at lowest values of CS/HA. The model also predicted that the optimum values are 4.15, 4.14 and 180 (min) for the CS/HA, solution pH and stirring time, respectively. The obtained preparation had a size of 200 nm, polydispersity index of 0.37, and zeta potential of 13.0 mV.

  8. 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

  9. Analysis of Stable Low-Molecular-Weight RNA Profiles of Members of the Family Rhizobiaceae

    PubMed Central

    Velázquez, Encarna; Cruz-Sánchez, José María; Mateos, Pedro F.; Martínez-Molina, Eustoquio

    1998-01-01

    Staircase electrophoresis in polyacrylamide gels was used to analyze the stable low-molecular-weight (LMW) RNA profiles of 24 type strains belonging to the family Rhizobiaceae. This new electrophoretic technique results in good separation of the molecules forming the LMW RNA profiles. Differences in the number and distribution of the RNA bands in these profiles allowed us to identify differences among the 24 strains assayed. Species assignments based on LMW RNAs proved to be consistent with the established taxonomic classification. Analysis of the data obtained and the corresponding dendrograms revealed relationships between genera and species; these relationships were essentially the same as those obtained with other techniques, such as DNA hybridization and 16S rRNA sequencing. Use of the technique described here, with which it is possible to analyze a large number of strains in a short time, permits rapid identification of species belonging to the family Rhizobiaceae and should in the future facilitate biodiversity studies and detection of new species. PMID:9575134

  10. 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

  11. Quantification of a Non-conventional Protein Secretion: The Low-Molecular-Weight FGF-2 Example.

    PubMed

    Arcondéguy, Tania; Touriol, Christian; Lacazette, Eric

    2016-01-01

    Quantification of secreted factors is most often measured with enzyme-linked immunosorbent assay (ELISA), Western Blot, or more recently with antibody arrays. However, some of these, like low-molecular-weight fibroblast growth factor-2 (LMW FGF-2; the 18 kDa form), exemplify a set of secreted but almost non-diffusible molecular actors. It has been proposed that phosphorylated FGF-2 is secreted via a non-vesicular mechanism and that heparan sulfate proteoglycans function as extracellular reservoir but also as actors for its secretion. Heparan sulfate is a linear sulfated polysaccharide present on proteoglycans found in the extracellular matrix or anchored in the plasma membrane (syndecan). Moreover the LMW FGF-2 secretion appears to be activated upon FGF-1 treatment. In order to estimate quantification of such factor export across the plasma membrane, technical approaches are presented (evaluation of LMW FGF-2: (1) secretion, (2) extracellular matrix reservoir, and (3) secretion modulation by surrounding factors) and the importance of such procedures in the comprehension of the biology of these growth factors is underlined. PMID:27665555

  12. 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

  13. Effects of transgene-encoded high-molecular weight glutenin proteins in wheat flour blends and sponge and dough baking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    HMW glutenin subunits are the most important determinants of wheat (Triticum aestivum L.) bread-making quality, and subunit composition explains a large percentage of the variability observed between genotypes. Experiments were designed to elevate expression of a key native HMW glutenin subunit (1D...

  14. 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...

  15. 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...

  16. Acute dyspnea in a woman with swelling of the left leg treated with low molecular weight heparine.

    PubMed

    Luyx, C; Vanpee, D; Douala, C; Gillet, J B

    2001-05-01

    A case of rectus sheath hematoma diagnosed initially as probable pulmonary embolism in a patient on anticoagulation with low molecular weight heparins for swelling of the left leg is presented. Prompt consideration of this hematoma in the emergency department is important to avoid unnecessary and potentially dangerous treatment. PMID:11326351

  17. Membrane disruption by antimicrobial fatty acids releases low-molecular-weight proteins from Staphylococcus aureus.

    PubMed

    Parsons, Joshua B; Yao, Jiangwei; Frank, Matthew W; Jackson, Pamela; Rock, Charles O

    2012-10-01

    The skin represents an important barrier for pathogens and is known to produce fatty acids that are toxic toward gram-positive bacteria. A screen of fatty acids as growth inhibitors of Staphylococcus aureus revealed structure-specific antibacterial activity. Fatty acids like oleate (18:1Δ9) were nontoxic, whereas palmitoleate (16:1Δ9) was a potent growth inhibitor. Cells treated with 16:1Δ9 exhibited rapid membrane depolarization, the disruption of all major branches of macromolecular synthesis, and the release of solutes and low-molecular-weight proteins into the medium. Other cytotoxic lipids, such as glycerol ethers, sphingosine, and acyl-amines blocked growth by the same mechanisms. Nontoxic 18:1Δ9 was used for phospholipid synthesis, whereas toxic 16:1Δ9 was not and required elongation to 18:1Δ11 prior to incorporation. However, blocking fatty acid metabolism using inhibitors to prevent acyl-acyl carrier protein formation or glycerol-phosphate acyltransferase activity did not increase the toxicity of 18:1Δ9, indicating that inefficient metabolism did not play a determinant role in fatty acid toxicity. Nontoxic 18:1Δ9 was as toxic as 16:1Δ9 in a strain lacking wall teichoic acids and led to growth arrest and enhanced release of intracellular contents. Thus, wall teichoic acids contribute to the structure-specific antimicrobial effects of unsaturated fatty acids. The ability of poorly metabolized 16:1 isomers to penetrate the cell wall defenses is a weakness that has been exploited by the innate immune system to combat S. aureus.

  18. Ocular toxicity of low-molecular-weight components of silicone and fluorosilicone oils.

    PubMed

    Nakamura, K; Refojo, M F; Crabtree, D V; Pastor, J; Leong, F L

    1991-11-01

    Silicone oil (SiO) and fluorosilicone oil (FSiO) are injected into the vitreous cavity in difficult cases of retinal detachment surgery. SiO and FSiO contain linear and cyclic low-molecular-weight components (LMWC) that are thought to cause ocular toxicity. Using the purified oils (without LMWC) and some of the individual LMWC, the authors evaluated the relation of the LMWC to the short-term ocular toxicity of the oils. When octamethylcyclotetrasiloxane or other single small species of linear and cyclic LMWC of SiO were injected into the rabbit anterior chamber, severe inflammation and corneal edema were induced. The ocular responses to the single species of the LMWC of SiO decreased with an increase of the molecular weights. Cyclic LMWC of FSiO (a mixture of trimethyl-3,3,3-trifluoropropylcyclotrisiloxane and tetramethyl-3,3,3-trifluoropropylcyclotetrasiloxane) also induced inflammation and corneal edema. However, unpurified SiO and FSiO, as well as purified oils (via solvent fractionation), did not cause significant adverse ocular response, presumably because the amounts of LMWC (especially the smallest species) in the oils were relatively small. Using gas chromatography, the authors analyzed SiO and FSiO recovered from rabbit and human vitreous cavities up to 2 yr after injection. In most of the cases, the concentrations of LMWC in SiO decreased after injection. This is consistent with the possibility that LMWC diffused from the oils into the ocular tissues. The long-term effect of LMWC in intraocular SiO and FSiO has not been determined. However, diffusion of LMWC into ocular tissues may relate to the chronic ocular toxicity of the oils.

  19. Novel low-molecular-weight hypromellose polymeric films for aqueous film coating applications.

    PubMed

    Bruce, Hollie F; Sheskey, Paul J; Garcia-Todd, Paula; Felton, Linda A

    2011-12-01

    The concentration of hypromellose (HPMC) is known to significantly impact the viscosity of coating solutions. The purpose of this study was to determine the viscosity of novel low-molecular-weight (LMW) HPMC products as a function of polymer concentration. The mechanical properties and water vapor permeability of free films prepared from these novel LMW HPMC polymers were also determined and the results were compared with films prepared with conventional HPMC. Solutions of LMW and conventional HPMC 2910 and 2906 containing up to 40% polyethylene glycol (PEG) 400 were prepared and the viscosities were measured using a Brookfield viscometer. Solutions were then cast onto glass plates and stored at 30?C and 50% relative humidity until films were formed. A Chatillon digital force gauge attached to a motorized test stand was used to quantify the mechanical properties of the films, whereas water vapor permeabilities were determined according to the ASTM E96 M-05 water method. As expected, the novel LMW polymer solutions exhibited significantly lower viscosities than the conventional comparators at equivalent polymer concentrations. Film strength of the LMW materials was lower than films prepared from the conventional HPMC solutions, although this effect was not as evident for the HPMC 2906 chemistry. Increasing concentrations of the plasticizer resulted in decreased tensile strength and Young?s modulus and increased elongation as well as increased water vapor permeability, irrespective of polymer type. No statistical difference was found between the tensile strength to Young?s modulus ratios of the F chemistry LMW and conventional HPMC polymer films.

  20. Significance of low molecular weight C1q in systemic lupus erythematosus.

    PubMed

    Hoekzema, R; Swaak, A J; Brouwer, M C; van Rooijen, A; Nieuwenhuys, E J; Hack, C E

    1990-09-01

    The significance of high serum concentrations of low molecular weight C1q (LMW-C1q) in patients with systemic lupus erythematosus (SLE) was studied. Concentrations of LMW-C1q were increased in SLE, but not in rheumatoid arthritis or acute poststreptococcal glomerulonephritis. Concentrations of LMW-C1q in SLE serum samples correlated with titres of anti-dsDNA and were inversely related to concentrations of normal C1q and C3. Serial studies in six patients, who had rising anti-dsDNA titres and who developed a major exacerbation requiring admission to hospital, showed that LMW-C1q increased in parallel with anti-dsDNA, reaching peak values of more than 2000% of normal just before or at the time of clinical relapse and decreasing during convalescence. Most marked increases in LMW-C1q were noted in the three patients in whom C1q concentrations remained normal, whereas increases were less in the three patients who had strongly depressed concentrations of normal C1q. A study of C1q biosynthesis by macrophages cultured from patients with SLE and high serum concentrations of LMW-C1q did not show impaired secretion of normal C1q in favour of LMW-C1q, but indicated that serum concentrations of LMW-C1q may reflect the synthetic rate of C1q in vivo. The results show that increased serum concentrations of LMW-C1q may be helpful in diagnosing SLE and suggest that serial determination of LMW-C1q in serum may have predictive value in monitoring patients with SLE.

  1. Low molecular weight PEIs modified by hydrazone-based crosslinker and betaine as improved gene carriers.

    PubMed

    Fang, Gang; Zeng, Fang; Yu, Changmin; Wu, Shuizhu

    2014-10-01

    Low-molecular-weight polyethyleneimine (LMW PEI) exhibits poorer transfection efficiency but lower cytotoxicity compared to high-molecular-weight polyethyleneimine (such as PEI 25kDa). To enhance the gene transfection performance of LMW PEI, we herein demonstrate a new strategy for modifying LMW PEI. A crosslinker containing an acid-labile hydrazone bond (hydrazone-based crosslinker) was synthesized and used to crosslink PEI 1.8kDa and convert it into higher-molecular-weight polycations. And the crosslinked polycations were further modified by incorporating a betaine monomer [N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate, DMAAPS] onto their surfaces. The molar percentages of the incorporated betaine molecules to amino groups on the polycations were determined as 21.2%, 36.0% and 77.2%, respectively. Molecular weights of the modified polycations were measured using capillary viscometry at pH 7.4 and 5.0, respectively, and the degradation of the polymers in acidic solution was confirmed. The PEIs modified with hydrazone and betaine (PEI-Hdz-DMAAPS) exhibit much lower cytotoxicity than PEI 25K, and they also show no or little hemolytic effect with their hemolysis rates around 5%. PEI-Hdz-DMAAPS21.2%/DNA and PEI-Hdz-DMAAPS36.0%/DNA complexes exhibit high transfection efficiencies, which are comparable to or higher than that of PEI 25K/DNA complex in the absence or presence of 10% serum. With these improved gene delivery properties, the PEI-Hdz-DMAAPS samples have great potential for serving as efficient gene carriers. This strategy may provide some insights for constructing some other biocompatible materials.

  2. 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

  3. Development of implants for sustained release of 5-fluorouracil using low molecular weight biodegradable polymers.

    PubMed

    Hanafy, A Fh; El-Egaky, A M; Mortada, S A; Molokhia, A M

    2009-12-01

    Anticancer drugs have poor efficacy especially against solid tumors that hinder drug penetration into the tumor. Thus, the dose has to be increased, but toxicity is a limiting factor. Local administration of a polymeric biodegradable poly-L-lactic acid (PLA) and poly(L-lactic acid-co-glycolic acid) copolymer (PLGA) implant containing an anticancer drug may be an acceptable method of concentrating the drug near the tumor site. This work sought to synthesize low molecular weight PLA and PLGA by polycondensation to yield polymers with good physical properties to make them suitable for use in implantable therapy. The synthesized polymers were characterized by determining their molecular weight, melting point, and percentage crystallinity using DSC. Fourier transformationinfra red spectrum (FT-IR), nuclear magnetic resonance (NMR) and specific optical rotation measurement were also used to characterize the synthesized polymers. Morphological characteristics were assessed using scanning electron microscopy (SEM). Implants were manufactured using compression (C) and injection molding (IM) and were loaded with 12 mg 5-fluorouracil (5-FU) per 120 mg implant. In vitro release patterns of all implants were assessed in phosphate buffered saline pH 7.4 (PBS 7.4) at 37°C. Factors affecting the release of 5-FU from implants were the polymer species, manufacturing technique, drug particle size, drug concentration, implant dimensions, and coating of the implant. Implants prepared with PLGA had significantly faster release of 5-FU than those prepared with PLA. Those manufactured using compression had significantly faster drug release than those prepared by injection molding. A PLA implant that contained 12 mg 5-FU/120 mg with a diameter of 0.3 cm and that was loaded with a drug particle size smaller than 150 μm and prepared by injection molding and then subsequently coated with PLA had the longest release period of 45 days.

  4. 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.

  5. Dendrimers as a carrier for pulmonary delivery of enoxaparin, a low-molecular weight heparin.

    PubMed

    Bai, Shuhua; Thomas, Chandan; Ahsan, Fakhrul

    2007-08-01

    This study was designed to test the hypothesis that positively charged dendrimers form a complex with enoxaparin, a low-molecular weight heparin (LMWH), and that the resulting drug-dendrimer complex is effective in preventing deep vein thrombosis after pulmonary administration. Fourier Transform Infrared (FTIR) spectroscopy and the azure A assay were used to evaluate interactions between dendrimers and enoxaparin. The efficacy of polyamidoamine (PAMAM) dendrimers in enhancing pulmonary absorption of enoxaparin was studied by administering enoxaparin-dendrimer formulations into the lungs of anesthetized rats and monitoring drug absorption by measuring plasma anti-factor Xa activity. The optimized formulations were evaluated for their efficacy in preventing deep vein thrombosis in a rodent model. The safety of the formulations was tested by studying their effects on mucociliary transport rate (MTR) in a frog palate model and by measuring injury markers in rat bronchoalveolar fluid. The FTIR data and azure A assay revealed ionic interactions between the amino groups of cationic dendrimers and the carboxylic and sulfate groups of enoxaparin. Positively charged dendrimers increased the relative bioavailability of enoxaparin by 40%, while a negatively charged dendrimer had no effect. Formulations containing 1% G2 or 0.5% G3 PAMAM dendrimer plus enoxaparin were as efficacious in preventing deep vein thrombosis in a rat model as subcutaneously administered enoxaparin. The formulations did not adversely affect the MTR or produce extensive damage to the lungs. Positively charged dendrimers are a suitable carrier for pulmonary delivery of enoxaparin. They enhance pulmonary absorption of LMWH probably by reducing negative surface charge density of the drug molecule. PMID:17286291

  6. 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

  7. [Effect of wheat and faba bean intercropping on root exudation of low molecular weight organic acids].

    PubMed

    Xiao, Jing-Xiu; Zheng, Yi; Tang, Li

    2014-06-01

    Pot experiment of wheat and faba bean intercropping was conducted and exudates from wheat and faba bean roots were collected at different growth stages. Low molecular weight organic acids (OA) in root exudates were examined by HPLC. The results showed that wheat and faba bean intercropping significantly increased the total amounts of OA exuded by roots. At tillering (57 d), booting (120 d) and filling stages (142 d), intercropping increased the total amounts of OA in wheat root exudates by 155%, 35.6% and 92.6% respectively, in comparison with that of monoculture wheat (MW). At branching (57 d) and filling stages (142 d), intercropping increased the total amounts of OA in faba bean root exudates by 87.4% and 38.7%, respectively, in comparison with that of monoculture faba bean (MF). Wheat and faba bean intercropping changed the types of OA exuded by roots. At tillering stage, lactic acid was identified in root exudates of intercropping wheat (IW), but not in that of MW. At jointing stage (98 d), citric acid was identified in root exudates of IW, but not in that of MW, and acetic acid was vice versa. At branching stage, acetic acid was identified in root exudates of intercropping faba bean (IF), but not in that of MF, and lactic acid was vice versa. At filling stage, lactic acid was identified in root exudates of IF, but not in that of MF. Wheat and faba bean intercropping increased the OA exudation rate of wheat. At booting stage, the exudation rates of citric and fumaric acid from IW were 179 and 184-times as that of from MW, respectively. At filling stage, the exudation rate of lactic acid from IW was 2.53-times as that from MW. In conclusion, wheat and faba bean intercropping increased the rate and total amount, and changed the types of OA exuded by roots.

  8. 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.

  9. Anti Xa monitoring during treatment with low molecular weight heparin or danaparoid: inter-assay variability.

    PubMed

    Kitchen, S; Iampietro, R; Woolley, A M; Preston, F E

    1999-10-01

    If laboratory monitoring of low molecular weight heparin (LMWH) therapy is required the test of choice is the anti Xa activity assay. The relationship between anti Xa results obtained using different techniques is unknown. The aim of the present study was to compare anti Xa results obtained with eight different commercially available anti Xa activity assays (five chromogenic and three clotting based assays) in samples from patients receiving either therapeutic or prophylactic LMWH (enoxaparin or dalteparin) or danaparoid. We have demonstrated that highly significant differences exist between results obtained using different techniques. The mean anti Xa activity in patients receiving treatment or prophylaxis with enoxaparin ranged from 0.28 to 0.64 iu/ml. A similar relationship was present in samples from patients treated with dalteparin, mean anti Xa results ranging from 0.43 to 0.69 iu/ml. The Heptest clotting assay as used here in combination with the Automated Coagulation Laboratory instrument, was associated with lower results than other clotting or chromogenic techniques. In patients receiving danaparoid for heparin induced thrombocytopaenia (HIT) mean results with three clotting based assays were 0.30 to 0.36 u/ml, compared to mean results of 0.47 to 0.65 u/ml for chromogenic assays. Our data clearly indicate that the selection of anti Xa assay method could influence patient management since the dose required to achieve the therapeutic range would differ according to the assay employed. This is particularly important since the frequency of haemorrhagic side effects has been shown by others to be dose dependent, irrespective of the concomitant anti Xa activity results. In danaparoid therapy the clotting assays studied here should not be employed for monitoring without a modified target range, unless it can be demonstrated that the higher doses required to achieve the therapeutic range are safe. PMID:10544915

  10. Where and When To Inject Low Molecular Weight Heparin in Hemodiafiltration? A Cross Over Randomised Trial

    PubMed Central

    Dhondt, Annemieke; Pauwels, Ruben; Devreese, Katrien; Eloot, Sunny; Glorieux, Griet; Vanholder, Raymond

    2015-01-01

    Background and Objective Low molecular weight heparins (LMWHs) are small enough to pass large pore dialysis membranes. Removal of LMWH if injected before the start of the session is possible during high-flux dialysis and hemodiafiltration. The aim of this study was to determine the optimal mode (place and time) of tinzaparin administration during postdilution hemodiafiltration. Study Design, Setting, Patients In 13 chronic hemodiafiltration patients, 3 approaches of injection were compared in a randomised cross over trial: i) before the start of the session at the inlet blood line filled with rinsing solution (IN0), ii) 5 min after the start at the inlet line filled with blood (IN5) and iii) before the start of the session at the outlet blood line (OUT0). Anti-Xa activity, thrombin generation, visual clotting score and reduction ratios of urea and beta2microglobulin were measured. Results Anti-Xa activity was lower with IN0 compared with IN5 and OUT0, and also more thrombin generation was observed with IN0. No differences were observed in visual clotting scores and no clinically relevant differences were observed in solute reduction ratio. An anti-Xa of 0.3 IU/mL was discriminative for thrombin generation. Anti-Xa levels below 0.3 IU/mL at the end of the session were associated with worse clotting scores and lower reduction ratio of urea and beta2microglobulin. Conclusions Injection of tinzaparin at the inlet line before the start of postdilution hemodiafiltration is associated with loss of anticoagulant activity and can therefore not be recommended. Additionally, we found that an anti-Xa above 0.3 IU/mL at the end of the session is associated with less clotting and higher dialysis adequacy. Trial Registration Clinicaltrials.gov NCT00756145 PMID:26076014

  11. 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.

  12. Possible pathogenetic role of low-molecular-weight proteins in Balkan nephropathy.

    PubMed

    Batuman, V

    1991-11-01

    Balkan endemic nephropathy (BEN) is a tubulointerstitial disease characterized by increased-low-molecular-weight protein (LMWP), most notably, beta 2-microglobulin (beta 2m) excretion in urine. We previously demonstrated that two species of LMWPs, immunoglobulin light chains (LC) and recombinant alpha interferon (rIF), are toxic at proximal tubule cell membrane level. Myeloma LCs and rIF inhibit Na-dependent uptake of 14C-L-alanine and 14C-D-glucose by rat renal brush border membrane (BBM) vesicles at half-maximal inhibitory concentrations, IC50, ranging from 68 to 140 microM for LCs, and 5.4 to 18 nM for rIF. We further demonstrated that LCs bind to high-capacity, low-affinity sites on BBM with dissociation constants (Kd) ranging from 16 to 118 microM, a range similar to IC50s observed with the same LCs. Binding site occupancy is inversely related to alanine (r = -0.95, P less than 0.01), and glucose uptake (r = -0.96, P less than 0.01), implying that LC nephrotoxicity is determined by its binding to BBM. beta 2m shares behavioral and structural similarities with both LC and rIF. Preliminary studies in our laboratory showed that unlabeled LCs compete for the same binding sites on BBM with beta 2m. These observations confirm that all LMWP, including beta 2m, are potentially nephrotoxic. Thus, the characteristic beta 2-microglobulinuria of BEN may be more than a consequence of tubular dysfunction, and may play a pathogenetic role.

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

    PubMed

    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

  14. Efficacy and safety of once daily low molecular weight heparin (tinzaparin sodium) in high risk pregnancy.

    PubMed

    Ní Ainle, Fionnuala; Wong, Audris; Appleby, Niamh; Byrne, Brigitte; Regan, Carmen; Hassan, Tayyaba; Milner, Marie; Sullivan, Ann O; White, Barry; O'Donnell, James

    2008-10-01

    Low molecular weight heparin (LMWH) is widely regarded as the anticoagulant treatment of choice for the prevention and treatment of venous thromboembolism during pregnancy. However, previous studies have demonstrated that the pharmacokinetic profiles of LMWH vary significantly with increasing gestation. Consequently, it remains unclear whether LMWH regimens recommended for use in nonpregnant individuals can be safely extrapolated to pregnant women. The aims of this study were to assess the safety and the efficacy of tinzaparin sodium (Innohep) administered only once daily during pregnancy. A systematic retrospective review identified a cohort of 37 high-risk pregnancies which had been managed using tinzaparin 175 IU/kg once daily. In 26 cases, the index pregnancy had been complicated by development of an acute venous thromboembolism (17 deep vein thrombosis and nine pulmonary embolism). For each individual, case notes were examined and data extracted using a predetermined questionnaire. No episodes of recurrent venous thromboembolism were identified amongst this cohort of pregnancies managed using once daily LMWH administration. However, two unusual thrombotic complications were observed, including a parietal infarct in one patient, and a postpartum cerebral venous thrombosis in another. Once daily tinzaparin was well tolerated, with no cases of heparin-induced thrombocytopaenia, symptomatic osteoporosis, or foetal malformations. Tinzaparin dose modification based upon peak anti-Xa levels occurred in 45% of the cases examined. The present study is the largest study to have examined the clinical efficacy of once daily LMWH for use in pregnant women at high risk of venous thromboembolism. Our data support the safety and efficacy of antenatal tinzaparin at a dose of 175 IU/kg. In order to determine whether this once daily regimen provides equivalent (or indeed greater) thromboprophylaxis to twice daily LMWH regimens during pregnancy will require highly powered direct

  15. [Adsorption of aflatoxin on montmorillonite modified by low-molecular-weight humic acids].

    PubMed

    Yao, Jia-Jia; Kang, Fu-Xing; Gao, Yan-Zheng

    2012-03-01

    The adsorption of a typical biogenic toxin aflatoxin B1 on montmorillonite modified by low-molecular-weight humic acids (M(r) < 3 500) was investigated. The montmorillonite rapidly adsorbed the aflatoxin B1 until amounting to the maximal capacity, and then the adsorbed aflatoxin B1 slowly released into solution and reached the sorption equilibrium state after 12 h. The sorption isotherm of aflatoxin B1 by montmorillonite could be well described by Langmiur model, while the sorption isotherm by humic acid-modified montmorillonite was well fitted by using the Freundlich model. The modification of the montmorillonite with humic acids obviously enhanced its adsorption capacity for aflatoxin B1, and the amounts of aflatoxin adsorbed by modified montmorillonite were obviously higher than those by montmorillonite. The sorption enhancement by humic acid modification was attributed to (1) the enlarged adsorption sites which owed to the surface collapse of crystal layers induced by organic acids, and (2) the binding of aflatoxin with the humic acid sorbed on mineral surface. In addition, the adsorption amounts of aflatoxin by montmorillonite and modified montmorillonite increased with the increase of pH values in solution, and more significant enhancement was observed for the latter than the former, which attributed to the release of humic acids from the modified montmorillonite with the high pH values in solution. This indicates that increasing the pH values resulted in the enhanced hydrophilic property and the release of the organic acids presented in modified montmorillonite, and more sorption sites were available for aflatoxin on the modified montmorillonite. Results of this work would strengthen our understanding of the behavior and fate of biological contaminants in the environment.

  16. Versatile low-molecular-weight hydrogelators: achieving multiresponsiveness through a modular design.

    PubMed

    Milanesi, Lilia; Hunter, Christopher A; Tzokova, Nadejda; Waltho, Jonathan P; Tomas, Salvador

    2011-08-22

    Multiresponsive low-molecular-weight hydrogelators (LMWHs) are ideal candidates for the development of smart, soft, nanotechnology materials. The synthesis is however very challenging. On the one hand, de novo design is hampered by our limited ability to predict the assembly of small molecules in water. On the other hand, modification of pre-existing LMWHs is limited by the number of different stimuli-sensitive chemical moieties that can be introduced into a small molecule without seriously disrupting the ability to gelate water. Herein we report the synthesis and characterization of multistimuli LMWHs, based on a modular design, composed of a hydrophobic, disulfide, aromatic moiety, a maleimide linker, and a hydrophilic section based on an amino acid, here N-acetyl-L-cysteine (NAC). As most LMWHs, these gelators experience reversible gel-to-sol transition following temperature changes. Additionally, the NAC moiety allows reversible control of the assembly of the gel by pH changes. The reduction of the aromatic disulfide triggers a gel-to-sol transition that, depending on the design of the particular LMWH, can be reverted by reoxidation of the resulting thiol. Finally, the hydrolysis of the cyclic imide moieties provides an additional trigger for the gel-to-sol transition with a timescale that is appropriate for use in drug-delivery applications. The efficient response to the multiple external stimuli, coupled to the modular design makes these LMWHs an excellent starting point for the development of smart nanomaterials with applications that include controlled drug release. These hydrogelators, which were discovered by serendipity rather than design, suggest nonetheless a general strategy for the introduction of multiple stimuli-sensitive chemical moieties, to offset the introduction of hydrophilic moieties with additional hydrophobic ones, in order to minimize the upsetting of the critical hydrophobic-hydrophilic balance of the LMWH.

  17. Profile of low molecular weight tinzaparin sodium for anticoagulation during hemodialysis.

    PubMed

    Al-Saran, Khalid A; Sabry, Alaa; Taha, Moammer; Ghafour, Mamdouh Abdul; Al Fawzan, Fawzan

    2010-01-01

    Low-molecular-weight heparin (LMWH) has been suggested as providing safe, efficient, convenient, and possibly more cost-effective anticoagulation for hemodialysis (HD) than unfractionated heparin (UFH) with a single bolus dose at the start of hemodialysis effectively prevents clot formation in the dialyzer and bubble trap with fewer side-effects and possible benefits on uremic dyslipidemia. In this study, we compared the safety, clinical efficacy, and cost effectiveness of tinzaparin sodium (Innohep) with unfractionated heparin (UFH) in 23 chronic HD patients; their extracorporeal anticoagulant protocol consisted of UFH was switched to tinzaparin for a period of 6 months. Clinical clotting (grade 1-4) was evaluated by visual inspection after blood draining of the air trap every hour and the dialyzer after each session. Anticoagulation with tinzaparin sodium resulted in less frequent dialyzer and air-trap clotting compared to UFH (P= 001 and 0.04 respectively). Over 24 weeks, we observed no alteration in the serum lipid profile of the patients. There was a statistically significant improvement in the dialysis single pool Kt/V after 6 months of tinzaparin use (1.40 + or - 0.28 for tinzaparin versus 1.23 + or - 0.28 for heparin) without any modification in the hemodialysis prescription. The total cost for 24 weeks use of tinzaparin sodium was 23% more expensive compared to that for UFH. We conclude that a single bolus of Tinzaparin sodium injection at the start of the dialysis session was more effective and convenient in our patients than UFH, but at a higher total cost. Furthermore, at least on the short term, there was no observed benefit on the lipid profile.

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

    PubMed

    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

  19. A thermosensitive low molecular weight hydrogel as scaffold for tissue engineering.

    PubMed

    Ziane, Sophia; Schlaubitz, Silke; Miraux, Sylvain; Patwa, Amit; Lalande, Charlotte; Bilem, Ibrahim; Lepreux, Sébastien; Rousseau, Benoît; Le Meins, Jean-François; Latxague, Laurent; Barthélémy, Philippe; Chassande, Olivier

    2012-02-23

    Hydrogels that are non-toxic, easy to use, cytocompatible, injectable and degradable are valuable biomaterials for tissue engineering and tissue repair. However, few compounds currently fulfil these requirements. In this study, we describe the biological properties of a new type of thermosensitive hydrogel based on low-molecular weight glycosyl-nucleosyl-fluorinated (GNF) compound. This gel forms within 25 min by self-assembly of monomers as temperature decreases. It degrades slowly in vitro and in vivo. It induces moderate chronic inflammation and is progressively invaded by host cells and vessels, suggesting good integration to the host environment. Although human adult mesenchymal stem cells derived from adipose tissue (ASC) cannot adhere on the gel surface or within a 3D gel scaffold, cell aggregates grow and differentiate normally when entrapped in the GNF-based gel. Moreover, this hydrogel stimulates osteoblast differentiation of ASC in the absence of osteogenic factors. When implanted in mice, gel-entrapped cell aggregates survive for several weeks in contrast with gel-free spheroids. They are maintained in their original site of implantation where they interact with the host tissue and adhere on the extracellular matrix. They can differentiate in situ into alkaline phosphatase positive osteoblasts, which deposit a calcium phosphate-rich matrix. When injected into subcutaneous sites, gel-encapsulated cells show similar biological properties as implanted gel-cells complexes. These data point GNF-based gels as a novel class of hydrogels with original properties, in particular osteogenic potential, susceptible of providing new therapeutic solutions especially for bone tissue engineering applications.

  20. Relationship between chemical structure and the occupational asthma hazard of low molecular weight organic compounds

    PubMed Central

    Jarvis, J; Seed, M; Elton, R; Sawyer, L; Agius, R

    2005-01-01

    Aims: To investigate quantitatively, relationships between chemical structure and reported occupational asthma hazard for low molecular weight (LMW) organic compounds; to develop and validate a model linking asthma hazard with chemical substructure; and to generate mechanistic hypotheses that might explain the relationships. Methods: A learning dataset used 78 LMW chemical asthmagens reported in the literature before 1995, and 301 control compounds with recognised occupational exposures and hazards other than respiratory sensitisation. The chemical structures of the asthmagens and control compounds were characterised by the presence of chemical substructure fragments. Odds ratios were calculated for these fragments to determine which were associated with a likelihood of being reported as an occupational asthmagen. Logistic regression modelling was used to identify the independent contribution of these substructures. A post-1995 set of 21 asthmagens and 77 controls were selected to externally validate the model. Results: Nitrogen or oxygen containing functional groups such as isocyanate, amine, acid anhydride, and carbonyl were associated with an occupational asthma hazard, particularly when the functional group was present twice or more in the same molecule. A logistic regression model using only statistically significant independent variables for occupational asthma hazard correctly assigned 90% of the model development set. The external validation showed a sensitivity of 86% and specificity of 99%. Conclusions: Although a wide variety of chemical structures are associated with occupational asthma, bifunctional reactivity is strongly associated with occupational asthma hazard across a range of chemical substructures. This suggests that chemical cross-linking is an important molecular mechanism leading to the development of occupational asthma. The logistic regression model is freely available on the internet and may offer a useful but inexpensive adjunct to the

  1. 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.

  2. 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

  3. [Modified Mechanism of Cell Walls from Chinese Fir Treated with Low-Molecular-Weight Phenol Formaldehyde Resin].

    PubMed

    Huang, Yan-hui; Fei, Ben-hua; Zhao, Rong-jun

    2015-12-01

    Study on the modified mechanism of wood cell walls, it is very important for improving treatment reagents, optimizing treatment technology, and enhancing wood density, mechanical properties, dimensional stability, and so on. Samples of plantation Chinese fir were treated gradually with synthesized water-soluble low-molecular-weight phenol formaldehyde (PF) resins under vacuum and pressure. The correlated physical and chemical properties of the treated and untreated reference samples were determined by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), and nuclear magnetic resonance spectrometer(NMR) (Using method of Cross Polarization/Magic Angle Spinning for continuous testing) with high precision and resolution. The results showed that, after treated with water-soluble low-molecular-weight PF resin, the average values of crystallinity from the treated samples were decreased obviously, and the average reduction rate was 12.67%, 11.91% and 6.26%, respectively. Comparing water-soluble, low-molecular-weight PF resin modified Chinese fir with untreated reference samples, no new chemical shifts and characteristic peaks of functional groups from esters, ethers, etc. were present by using FTIR and ¹³C NMR spectrum. It was considered that there was no distinct chemical reaction between the water-soluble low-molecular-weight PF resin and Chinese Fir cell walls. But water-soluble low-molecular-weight PF resin could enter into the structure relatively loose, large size spaces, relatively area large amorphous regions in cell walls of Chinese fir tracheids, and form physical filling, which resulting in the decreasing of relative crystallinity. This study has important reference value for the development of new wood modification reagents and the optimization of wood modification process. The findings also provide important theoretical foundation for further proving the modification mechanisms of wood cell walls and enriching the modified theories of

  4. The regulation of factor IXa by supersulfated low molecular weight heparin.

    PubMed

    Misenheimer, Tina M; Sheehan, John P

    2010-11-23

    Supersulfated low molecular weight heparin (ssLMWH) inhibits the intrinsic tenase (factor IXa-factor VIIIa) complex in an antithrombin-independent manner. Recombinant factor IXa with alanine substitutions in the protease domain (K126A, N129A, K132A, R165A, R170A, N178A, R233A) was assessed with regard to heparin affinity in solution and ability to regulate protease activity within the factor IXa-phospholipid (PL) and intrinsic tenase complexes. In a soluble binding assay, factor IXa K126A, K132A, and R233A dramatically (10-20-fold) reduced ssLMWH affinity, while factor IXa N129A and R165A moderately (5-fold) reduced affinity relative to wild type. In the factor IXa-PL complex, binding affinity for ssLMWH was increased 4-fold, and factor X activation was inhibited with a potency 7-fold higher than predicted for wild-type protease-ssLMWH affinity in solution. In the intrinsic tenase complex, ssLMWH inhibited factor X activation with a 4-fold decrease in potency relative to wild-type factor IXa-PL. The mutations increased resistance to inhibition by ssLMWH in a similar fashion for both enzyme complexes (R233A > K126A > K132A/R165A > N129A/N178A/wild type) except for factor IXa R170A. This protease had ssLMWH affinity and potency for the factor IXa-PL complex similar to wild-type protease but was moderately resistant (6-fold) to inhibition in the intrinsic tenase complex based on increased cofactor affinity. These results are consistent with conformational regulation of the heparin-binding exosite and macromolecular substrate catalysis by factor IXa. An extensive overlap exists between the heparin and factor VIIIa binding sites on the protease domain, with residues K126 and R233 dominating the heparin interaction and R165 dominating the cofactor interaction.

  5. Marsh plant response to metals: Exudation of aliphatic low molecular weight organic acids (ALMWOAs)

    NASA Astrophysics Data System (ADS)

    Rocha, A. Cristina S.; Almeida, C. Marisa R.; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

    2016-03-01

    Metal exposure is known to induce the production and secretion of substances, such as aliphatic low molecular weight organic acids (ALMWOAs), into the rhizosphere by plant roots. Knowledge on this matter is extensive for soil plants but still considerably scarce regarding marsh plants roots adapted to high salinity media. Phragmites australis and Halimione portulacoides, two marsh plants commonly distributed in European estuarine salt marshes, were used to assess the response of roots of both species, in terms of ALMWOAs exudation, to Cu, Ni and Cd exposure (isolated and in mixture since in natural environment, they are exposed to mixture of metals). As previous studies were carried out in unrealistic and synthetic media, here a more natural medium was selected. Therefore, in vitro experiments were carried out, with specimens of both marsh plants, and in freshwater contaminated with two different Cu, Ni and Cd concentrations (individual metal and in mixture). Both marsh plants were capable of liberating ALMWOAs into the surrounding medium. Oxalic, citric and maleic acids were found in P. australis root exudate solutions and oxalic and maleic acids in H. portulacoides root exudate solutions. ALMWOA liberation by both plants was plant species and metal-dependent. For instance, Cu affected the exudation of oxalic acid by H. portulacoides and of oxalic and citric acids by P. australis roots. In contrast, Ni and Cd did not stimulate any specific response. Regarding the combination of all metals, H. portulacoides showed a similar response to that observed for Cu individually. However, in the P. australis case, at high metal concentration mixture, a synergetic effect led to the increase of oxalic acid levels in root exudate solution and to a decrease of citric acid liberation. A correlation between ALMWOAs exudation and metal accumulation could not be established. P. australis and H. portulacoides are considered suitable metal phytoremediators of estuarine impacted areas

  6. Hydrophobic modification of low molecular weight polyethylenimine for improved gene transfection.

    PubMed

    Teo, Pei Yun; Yang, Chuan; Hedrick, James L; Engler, Amanda C; Coady, Daniel J; Ghaem-Maghami, Sadaf; George, Andrew J T; Yang, Yi Yan

    2013-10-01

    Hydrophobic modification of low molecular weight (LMW) polyethylenimine (PEI) is known to increase gene transfection efficiency of LMW PEI. However, few studies have explored how the conjugated hydrophobic groups influence the properties of the modified LMW PEI mainly due to difficulties in obtaining well defined final product compositions and limitations in current chemical synthesis routes. The aim of this study was to modify LMW PEI (Mn 1.8 kDa, PEI-1.8) judiciously with different hydrophobic functional groups and to investigate how hydrophobicity, molecular structure and inclusion of hydrogen bonding properties in the conjugated side groups as well as the conjugation degree (number of primary amine groups of PEI-1.8 modified with hydrophobic groups) influence PEI-1.8 gene transfection efficiency. The modified polymers were characterized for DNA binding ability, particle size, zeta potential, in vitro gene transfection efficiency and cytotoxicity in SKOV-3 human ovarian cancer and HepG2 human liver carcinoma cell lines. The study shows that modified PEI-1.8 polymers are able to condense plasmid DNA into cationic nanoparticles, of sizes ~100 nm, whereas unmodified polymer/DNA complexes display larger particle sizes of 2 μm. Hydrophobic modification also increases the zeta potential of polymer/DNA complexes. Importantly, modified PEI-1.8 shows enhanced transfection efficiency over the unmodified counterpart. Higher transfection efficiency is obtained when PEI-1.8 is modified with shorter hydrophobic groups (MTC-ethyl) as opposed to longer ones (MTC-octyl and MTC-deodecyl). An aromatic structured functional group (MTC-benzyl) also enhances transfection efficiency more than an alkyl functional group (MTC-octyl). An added hydrogen-bonding urea group in the conjugated functional group (MTC-urea) does not enhance transfection efficiency over one without urea (MTC-benzyl). The study also demonstrates that modification degree greatly influences gene transfection, and

  7. Organic chemistry of basal ice - presence of labile, low molecular weight compounds available for microbial metabolism

    NASA Astrophysics Data System (ADS)

    Lis, Grzegorz P.; Wadham, Jemma L.; Lawson, Emily; Stibal, Marek; Telling, Jon

    2010-05-01

    Recent studies show that subglacial environments previously thought to be devoid of life contain a host of active microbial organisms. Presence of liquid water due to overburden pressure, the release of nutrients from chemical erosion of bedrock, and the potential carbon sources in overridden sediments facilitate life in this extreme environment. However, little is still known of concentrations and diversity of labile organic compounds essential for sustaining microbial metabolism in subglacial environments. Three subglacial ecosystems that considerably differ in range and amount of available organic compounds were selected for this study 1-Engabreen, northern Norway, overlying high-grade metamorphic rocks with low organic carbon content; 2-Finsterwalderbreen, Svalbard, overriding ancient black shales with a relatively high carbon content yet recalcitrant to microbiological consumption; and 3-Russell Glacier in western Greenland with recently overridden quaternary organic rich paleosols. Basal and pressure ridge ice samples were collected and subsequently analysed for low molecular weight organic compounds, with the emphasis on volatile fatty acids, carbohydrates and amino acids. The highest concentration of labile organic compounds in Greenland basal ice suggest that recently overridden paleosols have the greatest potential for sustaining microbial populations present within and underneath basal ice. The high concentration of "ancient" organic carbon in basal ice from Finsterwalderbreen, Svalbard, doesn't correlate with the presence of labile organic compounds. This indicates the inability of microbes to digest recalcitrant kerogen carbon in cold temperatures. In all three investigated environments, concentrations of labile organic compounds are elevated in basal ice with a high debris content. Until recently, most models of the global carbon cycle tend to neglect the pool of subglacial organic carbon as little is known about the range and concentrations of

  8. Low molecular weight protein enrichment on mesoporous silica thin films for biomarker discovery.

    PubMed

    Fan, Jia; Gallagher, James W; Wu, Hung-Jen; Landry, Matthew G; Sakamoto, Jason; Ferrari, Mauro; Hu, Ye

    2012-04-17

    The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the monitoring of therapeutic efficiency.(1-3) The circulating low molecular weight proteome (LMWP) composed of small proteins shed from tissues and cells or peptide fragments derived from the proteolytic degradation of larger proteins, has been associated with the pathological condition in patients and likely reflects the state of disease.(4,5) Despite these potential clinical applications, the use of Mass Spectrometry (MS) to profile the LMWP from biological fluids has proven to be very challenging due to the large dynamic range of protein and peptide concentrations in serum.(6) Without sample pre-treatment, some of the more highly abundant proteins obscure the detection of low-abundance species in serum/plasma. Current proteomic-based approaches, such as two-dimensional polyacrylamide gel-electrophoresis (2D-PAGE) and shotgun proteomics methods are labor-intensive, low throughput and offer limited suitability for clinical applications.(7-9) Therefore, a more effective strategy is needed to isolate LMWP from blood and allow the high throughput screening of clinical samples. Here, we present a fast, efficient and reliable multi-fractionation system based on mesoporous silica chips to specifically target and enrich LMWP.(10,11) Mesoporous silica (MPS) thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different polymer templates and polymer concentrations in the precursor solution, various pore size distributions, pore structures, connectivity and surface properties were determined and applied for selective recovery of low mass proteins. The selective parsing of the enriched peptides into different subclasses according to their physicochemical properties will enhance the efficiency of recovery and detection of low abundance species. In combination with mass

  9. Evidence for the presence of a low molecular-weight activator of suppressor monocytes (LASM) in dialysates of T lymphocytes.

    PubMed

    Nekam, K; Strelkauskas, A J; Fudenberg, H H; Donnan, G G; Goust, J M

    1981-05-01

    Lysates of peripheral blood T lymphocytes from healthy individuals were found to contain a low molecular-weight peptide that inhibited phytohaemagglutinin-induced DNA synthesis in vitro by autologous or allogeneic peripheral blood mononuclear cells. The peptide was dialysable, partially heat stable, resistant to trypsin, RNase, and DNase but not to pronase, and was not part of the membrane receptor involved in rosette formation by T lymphocytes with sheep erythrocytes. It was found to act through monocytes, inducing the synthesis of second mediator responsible for the inhibition of lymphocyte DNA synthesis. This inducer of inhibition, designated as "low molecular-weight activator of suppressor monocytes' (LASM), may have a role in the depression of cellular immune response seen in various pathological conditions involving the destruction of T lymphocytes. PMID:6972906

  10. Evidence for the presence of a low molecular-weight activator of suppressor monocytes (LASM) in dialysates of T lymphocytes.

    PubMed Central

    Nekam, K; Strelkauskas, A J; Fudenberg, H H; Donnan, G G; Goust, J M

    1981-01-01

    Lysates of peripheral blood T lymphocytes from healthy individuals were found to contain a low molecular-weight peptide that inhibited phytohaemagglutinin-induced DNA synthesis in vitro by autologous or allogeneic peripheral blood mononuclear cells. The peptide was dialysable, partially heat stable, resistant to trypsin, RNase, and DNase but not to pronase, and was not part of the membrane receptor involved in rosette formation by T lymphocytes with sheep erythrocytes. It was found to act through monocytes, inducing the synthesis of second mediator responsible for the inhibition of lymphocyte DNA synthesis. This inducer of inhibition, designated as "low molecular-weight activator of suppressor monocytes' (LASM), may have a role in the depression of cellular immune response seen in various pathological conditions involving the destruction of T lymphocytes. PMID:6972906

  11. Comparison of the evolution of low molecular weight phenolic compounds in typical Sherry wines: Fino, Amontillado, and Oloroso.

    PubMed

    García Moreno, M Valme; Barroso, Carmelo García

    2002-12-18

    Changes in the content of low molecular weight phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, aldehydes, and their esterified derivatives, tyrosol and 5-(hydroxymethyl)-2-furaldehyde) during the aging of three different classes of Sherry wine, Fino, Oloroso, and Amontillado, have been studied. The samples studied were taken from each of the scales of the particular aging system applied to the three classes of wine. Clear differences were observed in the behavior of the low molecular weight phenolic in the three classes of wine. The wines subjected to oxidative aging presented a higher phenolic content overall, with the exception of the esterified derivatives of phenolic compounds that are mainly found in the samples that have not undergone any process of oxidation. MANOVA results confirmed that there are significant differences between all of the samples of the three types of wines. Using LDA, a classification of 100% of the samples has been made. PMID:12475270

  12. [Preparation and antithrombogenicity of oxidated low molecular weight heparin-antithrombin complex coated-polyvinyl chloride tubing].

    PubMed

    Luo, Peng; Liu, Weiyong; Yang, Chun; Zhou, Hua; Cao, Ruijun; Yang, Jian

    2011-02-01

    Based on non-enzymatic protein glycated reaction, the sodium periodate-oxidated low molecular weight heparin-antithrombin covalent complex (SPLMWATH) was produced. By using polyethyleneimine-glutaraldehyde bonding technique, polyvinyl chloride (PVC) tubings were coated with SPLMWATH, heparin and low molecular weight heparin (LMWH). Spectrophotometry and dynamic clotting time experiment were used to determine the synthetic ratio of SPLMWATH, graft density, coating leaching ratio and to evaluate the antithrombogenicity of different coating on the PVC tubings. The results showed that the synthetic ratio of SPLMWATH was approximately 55%, and compared with heparin coating and LMWH coating, the graft density of SPLMWATH coating on the PVC tubing was smaller, but its coating stability and antithrombogenicity were significantly better than that of heparin coating and LMWH coating on the PVC tubings.

  13. Production of Laccase by Cochliobolus sp. Isolated from Plastic Dumped Soils and Their Ability to Degrade Low Molecular Weight PVC.

    PubMed

    Sumathi, Tirupati; Viswanath, Buddolla; Sri Lakshmi, Akula; SaiGopal, D V R

    2016-01-01

    One of the utmost man-made problems faced today has been the ever-increasing plastic waste filling the world. It accounts for an estimated 20-30% (by volume) of municipal solid waste in landfill sites worldwide. Research on plastic biodegradation has been steadily growing over the past four decades. Several fungi have been identified that produce enzymes capable of plastic degradation in various laboratory conditions. This paper presents a study that determined the ability of fungi to degrade low molecular weight polyvinyl chloride (PVC) by the enzyme laccase. We have isolated a fungal species, Cochliobolus sp., from plastic dumped soils and they were cultured on Czapek Dox Agar slants at 30°C. The effectiveness of this fungal species on the degradation of commercial low molecular weight polyvinyl chloride (PVC) was studied under laboratory conditions. Significant differences were observed from the FTIR, GC-MS, and SEM results in between control and Cochliobolus sp. treated PVC. PMID:27293894

  14. Production of Laccase by Cochliobolus sp. Isolated from Plastic Dumped Soils and Their Ability to Degrade Low Molecular Weight PVC

    PubMed Central

    Sumathi, Tirupati; Sri Lakshmi, Akula; SaiGopal, D. V. R.

    2016-01-01

    One of the utmost man-made problems faced today has been the ever-increasing plastic waste filling the world. It accounts for an estimated 20–30% (by volume) of municipal solid waste in landfill sites worldwide. Research on plastic biodegradation has been steadily growing over the past four decades. Several fungi have been identified that produce enzymes capable of plastic degradation in various laboratory conditions. This paper presents a study that determined the ability of fungi to degrade low molecular weight polyvinyl chloride (PVC) by the enzyme laccase. We have isolated a fungal species, Cochliobolus sp., from plastic dumped soils and they were cultured on Czapek Dox Agar slants at 30°C. The effectiveness of this fungal species on the degradation of commercial low molecular weight polyvinyl chloride (PVC) was studied under laboratory conditions. Significant differences were observed from the FTIR, GC-MS, and SEM results in between control and Cochliobolus sp. treated PVC. PMID:27293894

  15. Low molecular weight heparin in one or two doses for the initial treatment of venous thromboembolic disease?

    PubMed

    Albornoz, Juan Pablo; Valenzuela, Andrés; Aizman, Andrés

    2015-11-20

    The preferred dosification for low molecular weight heparins is in two doses for most patients with venous thromboembolic disease. A daily dose would make treatment simpler, less expensive and more comfortable while retaining a similar benefit and safety. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified two systematic reviews including five randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded it is not clear whether the risk of recurrence differs between the two alternatives because the certainty of the evidence is very low, and that administering low molecular weight heparin in two doses might be associated to little or no difference in the risk of major bleeding and mortality.

  16. Low molecular weight heparin in one or two doses for the initial treatment of venous thromboembolic disease?

    PubMed

    Albornoz, Juan Pablo; Valenzuela, Andrés; Aizman, Andrés

    2015-01-01

    The preferred dosification for low molecular weight heparins is in two doses for most patients with venous thromboembolic disease. A daily dose would make treatment simpler, less expensive and more comfortable while retaining a similar benefit and safety. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified two systematic reviews including five randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded it is not clear whether the risk of recurrence differs between the two alternatives because the certainty of the evidence is very low, and that administering low molecular weight heparin in two doses might be associated to little or no difference in the risk of major bleeding and mortality. PMID:26609705

  17. 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

  18. [Treatment with danaparoid during pregnancy for a woman with a cutenous allergy to low-molecular-weight heparin] .

    PubMed

    de Saint-Blanquat, L; Simon, L; Toubas, M F; Hamza, J

    2000-12-01

    The authors describe a case of heparin-induced skin reaction due to two preparations of low molecular weight heparin in a pregnant woman. The main characteristics of heparin-related cutaneous allergy are reported. The use of an heparinoid, usually indicated for patients with heparin-induced thrombocytopenia, appeared to be efficient and safe for the mother and her fetus. An epidural analgesia was performed for labor analgesia, 24 hours after the last injection of danaparid of sodium. PMID:11200764

  19. Microbial production of low molecular weight hyaluronic acid by adding hydrogen peroxide and ascorbate in batch culture of Streptococcus zooepidemicus.

    PubMed

    Liu, Long; Du, Guocheng; Chen, Jian; Zhu, Yang; Wang, Miao; Sun, Jun

    2009-01-01

    Microbial production of low molecular weight hyaluronic acid (HA) by the addition of hydrogen peroxide and ascorbate during the batch culture of Streptococcus zooepidemicus was investigated. Hydrogen peroxide (1.0 mmol/g HA) and ascorbate (0.5 mmol/g HA) were added at 8h and 12h to degrade HA. With the redox depolymerization of HA, the HA molecular weight decreased from 1,300 kDa for the control to 80 kDa, and the average broth viscosity during 8-16 h decreased from 360 mPa s for the control to 290 mPa s. The average oxygen mass transfer coefficient K(L)a increased from 10h(-1) for the control to 35 h(-1) and the average dissolved oxygen level increased from 1% of air saturation in the control to 10%. HA production increased from 5.0 g/L for the control to 6.5 g/L, and contributed to the increased redox potential and energy charge. This novel process not only significantly enhanced production of low molecular weight HA, but also improved purification efficiency due to a decreased broth viscosity. Low molecular weight HA finds applications in biomedical and healthcare fields.

  20. New low molecular weight polycation-based nanoparticles for effective codelivery of pDNA and drug.

    PubMed

    Zhao, Yu; Yu, Bingran; Hu, Hao; Hu, Yang; Zhao, Na-Na; Xu, Fu-Jian

    2014-10-22

    The development of new cationic nanoparticles that are safe and effective for biomedical applications has attracted considerable attention. Low molecular weight polycations generally exhibit low toxicity; however, their poor efficiency in drug delivery systems hampers their application. In this work, a series of new low molecular weight 2,6-bis(1-methylbenzimidazolyl)pyridinyl (BIP)-terminated ethanolamine-functionalized poly(glycidyl methacrylate)s (BIP-PGEAs) were readily fabricated for effective codelivery of a gene and a drug. The BIP-PGEAs could form well-defined cationic nanoparticles (NPs) in an aqueous solution. They could effectively bind pDNA with an appropriate particle size and ζ-potential. More importantly, the BIP-PGEA NPs demonstrated much higher transfection efficiencies than linear PGEA (L-PGEA) and the traditional "gold-standard" branched polyethylenimine (25 kDa). Moreover, the BIP-PGEA NPs could effectively entrap a hydrophobic anticancer drug such as 10-hydroxy camptothecin (CPT). The synergistic antitumor effect of the BIP-PGEA-CPT NPs was demonstrated by employing a suicide gene therapy system, which contained cytosine deaminase and 5-fluorocytosine (CD/5-FC). The present strategy for preparing well-defined cationic nanoparticles from low-molecular-weight polycations could provide an intriguing method to produce new multifunctional, therapeutic NPs.

  1. Heat-mediated, ultra-rapid electrophoretic transfer of high and low molecular weight proteins to nitrocellulose membranes.

    PubMed

    Kurien, Biji T; Scofield, R Hal

    2002-08-01

    Here, we report an ultra-rapid method for the transfer of high and low molecular weight proteins to nitrocellulose membranes following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In this procedure, the electro-transfer was performed with heated (70-75 degrees C) normal transfer buffer from which methanol had been omitted. Complete transfer of high and low molecular weight proteins (a purified protein, molecular weight protein standards and proteins from a human tissue extract) could be carried out in 10 min for a 0.75-mm, 7% SDS-PAGE gel. For 10% and 12.5% gels (0.75 mm), the corresponding time was 15 min. In the case of 1.5-mm gels, a complete transfer could be carried out in 20 min for 7%, 10% and 12.5% 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. When the heat-mediated transfer method was compared with a conventional transfer protocol, under similar conditions, we found that the latter method transferred minimal low molecular weight proteins while retaining most of the high molecular weight proteins in the gel. In summary, this procedure is very rapid, avoids the use of methanol and is particularly useful for the transfer of high molecular weight proteins.

  2. Tailoring of the nanotexture of mesoporous silica films and their functionalized derivatives for selectively harvesting low molecular weight protein.

    PubMed

    Hu, Ye; Bouamrani, Ali; Tasciotti, Ennio; Li, Li; Liu, Xuewu; Ferrari, Mauro

    2010-01-26

    We present a fast, efficient, and reliable system based on mesoporous silica chips to specifically fractionate and enrich the low molecular weight proteome. Mesoporous silica thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different templates and concentrations in the precursor solution, various pore size distributions, pore structures, and connectivity were obtained and applied for selective recovery of low mass proteins. In combination with mass spectrometry and statistic analysis, we demonstrated the correlation between the nanophase characteristics of the mesoporous silica thin films and the specificity and efficacy of low mass proteome harvesting. In addition, to overcome the limitations of the prefunctionalization method in polymer selection, plasma ashing was used for the first time for the treatment of the mesoporous silica surface prior to chemical modification. Surface charge modifications by different functional groups resulted in a selective capture of the low molecular weight proteins from serum sample. In conclusion, our study demonstrates that the ability to tune the physicochemical properties of mesoporous silica surfaces, for a selective enrichment of the low molecular weight proteome from complex biological fluids, has the potential to promote proteomic biomarker discovery.

  3. Comparison of biological activities of two low molecular weight heparins in 10 healthy volunteers.

    PubMed Central

    Azizi, M; Veyssier-Belot, C; Alhenc-Gelas, M; Chatellier, G; Billaud-Mesguish, E; Fiessinger, J N; Aiach, M

    1995-01-01

    1. Low molecular weight heparins (LMWHs) are produced by different depolymerization processes and may therefore differ with respect to their pharmacokinetic properties. 2. We designed a single dose, randomized cross-over study in 10 healthy volunteers to compare the 24 h pharmacokinetics of two LMWHs, reviparin and enoxaparin, which have been previously shown to be clinically equivalent in terms of post-operative deep vein thrombosis prevention, despite significant differences in their in vivo biological activity. The two LMWHs were subcutaneously administered at the same dosages that are used in clinical studies: 4250 anti-Xa iu for reviparin and 40 mg for enoxaparin which have similar in vitro anti-Xa activities. 3. The overall 24 h profiles of the plasma anti-Xa and anti-thrombin activities were similar for reviparin and enoxaparin. The Amax and the AUC(0, 24h) of plasma anti-Xa activity after reviparin administration were both slightly but significantly lower than those observed after enoxaparin administration (difference between treatments of 0.03 95% CI[0.01-0.05] iu ml-1 h and 0.56 95% CI[0.22-0.90] iu ml-1 for Amax and AUC(0, 24h) respectively). After adjustment for in vitro anti-Xa activity, the statistical difference between the two LMWHs persisted for the AUC(0, 24h) but not for the Amax of plasma anti-Xa activity. The tmax and the MRT values for plasma anti-Xa activity did not significantly differ between the two drugs. The t1/2 for reviparin did not significantly differ from that of enoxaparin (2.7 +/- 0.7 h vs 3.5 +/- 0.9 h respectively, NS). The Amax of the plasma anti-thrombin activity after reviparin administration was also slightly but significantly lower than that observed after enoxaparin administration, (difference between treatments of 0.018 95% CI[0.01-0.025] iu ml-1) whereas the AUC(0, 24h) of anti-thrombin activity vs time was not. A slight but significant increase of the activated partial thromboplastin time of a similar magnitude was

  4. Microbial utilization of low molecular weight organics in soil depends on the substances properties

    NASA Astrophysics Data System (ADS)

    Gunina, Anna

    2016-04-01

    Utilization of low molecular weight organic substances (LMWOS) in soil is regulated by microbial uptake from solution and following incorporation of into specific cell cycles. Various chemical properties of LMWOS, namely oxidation state, number of carbon (C) atoms, number of carboxylic (-COOH) groups, can affect their uptake from soil solution and further microbial utilization. The aim of the study was to trace the initial fate (including the uptake from soil solution and utilization by microorganisms) of three main classes of LMWOS, having contrast properties - sugars, carboxylic and amino acids. Top 10 cm of mineral soil were collected under Silver birch stands within the Bangor DIVERSE experiment, UK. Soil solution was extracted by centrifugation at 4000 rpm during 15 min. Soil was spiked with 14C glucose or fructose; malic, succinic or formic acids; alanine or glycine. No additional non-labeled LMWOS were added. 14C was traced in the dissolved organic matter (DOM), CO2, cytosol and soil organic matter (SOM) during one day. To estimate half-life times (T1 /2)of LMWOS in soil solution and in SOM pools, the single and double first order kinetic equations were fitted to the uptake and mineralization dynamics, respectively. The LMWOS T1 /2in DOM pool varied between 0.6-5 min, with the highest T1 /2for sugars (3.7 min) and the lowest for carboxylic acids (0.6-1.4 min). Thus, initial uptake of LMWOS is not a limiting step of microbial utilization. The T1 /2 of carboxylic and amino acids in DOM were closely related with oxidation state, showing that reduced substances remain in soil solution longer, than oxidized. The initial T1 /2 of LMWOS in SOM ranged between 30-80 min, with the longest T1 /2 for amino acids (50-80 min) and the shortest for carboxylic acids (30-48 min). These T1 /2values were in one-two orders of magnitude higher than LMWOS T1 /2 in soil solution, pointing that LMWOS mineralization occur with a delay after the uptake. Absence of correlations between

  5. Peptidylation for the determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    PubMed

    Tang, Feng; Cen, Si-Ying; He, Huan; Liu, Yi; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-05-23

    Determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been a great challenge in the analytical research field. Here we developed a universal peptide-based derivatization (peptidylation) strategy for the sensitive analysis of low-molecular-weight compounds by MALDI-TOF-MS. Upon peptidylation, the molecular weights of target analytes increase, thus avoiding serious matrix ion interference in the low-molecular-weight region in MALDI-TOF-MS. Since peptides typically exhibit good signal response during MALDI-TOF-MS analysis, peptidylation endows high detection sensitivities of low-molecular-weight analytes. As a proof-of-concept, we analyzed low-molecular-weight compounds of aldehydes and thiols by the developed peptidylation strategy. Our results showed that aldehydes and thiols can be readily determined upon peptidylation, thus realizing the sensitive and efficient determination of low-molecular-weight compounds by MALDI-TOF-MS. Moreover, target analytes also can be unambiguously detected in biological samples using the peptidylation strategy. The established peptidylation strategy is a universal strategy and can be extended to the sensitive analysis of various low-molecular-weight compounds by MALDI-TOF-MS, which may be potentially used in areas such as metabolomics.

  6. Efficacy and Safety of a Low-Molecular Weight Hyaluronic Acid Topical Gel in the Treatment of Facial Seborrheic Dermatitis

    PubMed Central

    Rowland Powell, Callie

    2012-01-01

    Objective: Hyaluronic acid sodium salt gel 0.2% is a topical device effective in reducing skin inflammation. Facial seborrheic dermatitis, characterized by erythema and or flaking/scaling in areas of high sebaceous activity, affects up to five percent of the United States population. Despite ongoing studies, the cause of the condition is yet unknown, but has been associated with yeast colonization and resultant immune-derived inflammation. First-line management typically is with topical steroids as well as the immunosuppressant agents pimecrolimus and tacrolimus. The objective of this study was to evaluate the efficacy and safety of a topical anti-inflammatory containing low-molecular weight hyaluronic acid. Design and setting: Prospective, observational, non-blinded safety and efficacy study in an outpatient setting. Participants: Individuals 18 to 75 years of age with facial seborrheic dermatitis. Measurements: Outcome measures included scale, erythema, pruritus, and the provider global assessment, which were all measured on a five-point scale. Subjects were assessed at Baseline, Week 2, Week 4, and Week 8. Results: Interim data for 7 of 15 subjects are presented. Hyaluronic acid sodium salt gel 0.2% was shown through visual grading assessments to improve the provider global assessment by 47.62 percent from Baseline to Week 4. Reductions in scale, erythema, and pruritus were 66.67, 50, and 60 percent, respectively at Week 4. At Week 8, the provider global assessment was improved from baseline in 100 percent of subjects. Conclusion: Treatment with topical low-molecular weight hyaluronic acid resulted in improvement in the measured endpoints. Topical low-molecular weight hyaluronic acid is another option that may be considered for the treatment of facial seborrheic dermatitis in the adult population. Compliance and tolerance were excellent. PMID:23125886

  7. Influence of high-molecular-weight glutenin subunit composition at Glu-A1 and Glu-D1 loci on secondary and micro structures of gluten in wheat (Triticum aestivum L.).

    PubMed

    Li, Xuejun; Liu, Tianhong; Song, Lijun; Zhang, Heng; Li, Liqun; Gao, Xin

    2016-12-15

    As one of critical gluten proteins, high-molecular-weight glutenin subunits (HMW-GS) mainly affect the rheological behaviour of wheat dough. The influence of HMW-GS variations at the Glu-A1 and Glu-D1 loci on both secondary and micro structures of gluten and rheological properties of wheat dough was investigated in this study. Results showed that the Amide I bands of the three near-isogenic lines (NILs) shifted slightly, but the secondary structures differed significantly. The micro structure of gluten in NIL 4 (Ax null) showed bigger apertures and less connection, compared to that in Xinong 1330 (Ax1). The micro structure of gluten in NIL 5 (Dx5+Dy10) showed more compact than that in Xinong 1330 (Dx2+Dy12). Correlation analysis demonstrated that the content of β-sheets and disulfide bonds in gluten has a significant relationship with dough properties. The secondary structures of native gluten are suggested to be used as predictors of wheat quality.

  8. Influence of high-molecular-weight glutenin subunit composition at Glu-A1 and Glu-D1 loci on secondary and micro structures of gluten in wheat (Triticum aestivum L.).

    PubMed

    Li, Xuejun; Liu, Tianhong; Song, Lijun; Zhang, Heng; Li, Liqun; Gao, Xin

    2016-12-15

    As one of critical gluten proteins, high-molecular-weight glutenin subunits (HMW-GS) mainly affect the rheological behaviour of wheat dough. The influence of HMW-GS variations at the Glu-A1 and Glu-D1 loci on both secondary and micro structures of gluten and rheological properties of wheat dough was investigated in this study. Results showed that the Amide I bands of the three near-isogenic lines (NILs) shifted slightly, but the secondary structures differed significantly. The micro structure of gluten in NIL 4 (Ax null) showed bigger apertures and less connection, compared to that in Xinong 1330 (Ax1). The micro structure of gluten in NIL 5 (Dx5+Dy10) showed more compact than that in Xinong 1330 (Dx2+Dy12). Correlation analysis demonstrated that the content of β-sheets and disulfide bonds in gluten has a significant relationship with dough properties. The secondary structures of native gluten are suggested to be used as predictors of wheat quality. PMID:27451241

  9. 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

  10. Preparation of Low Molecular Weight Gelatin Using Microwave Discharge Electrodeless Lamp/TiO2 Photocatalyst Hybrid System.

    PubMed

    Lee, Do-Jin; Kim, Hangun; Park, Young-Kwon; Kim, Byung Hoon; Lee, Heon; Jungf, Sana-Chul

    2016-02-01

    In this study, an MDEL/TiO2 photocatalyst hybrid system was applied to the production of low molecular weight gelatin. The molecular weight of produed gelatin decreased with increasing microwave intensity and increasing treatment time. The abscission of the chemical bonds between the con- stituents of gelatin by photocatalytic reaction did not alter the characteristics of gelatin. Formation of any by-products due to side reaction was not observed. It is suggested that gelatin was depolymerized by hydroxyl radicals produced during the MDEL/TiO2 photochemical reaction. PMID:27433727

  11. Solid State Structures of Alkali Metal Ion Complexes Formed by Low-Molecular-Weight Ligands of Biological Relevance.

    PubMed

    Aoki, Katsuyuki; Murayama, Kazutaka; Hu, Ning-Hai

    2016-01-01

    This chapter provides structural data, mainly metal binding sites/modes, observed in crystal structures of alkali metal ion complexes containing low-molecular-weight ligands of biological relevance, mostly obtained from the Cambridge Structural Database (the CSD version 5.35 updated to February 2014). These ligands include (i) amino acids and small peptides, (ii) nucleic acid constituents (excluding quadruplexes and other oligonucleotides), (iii) simple carbohydrates, and (iv) naturally occurring antibiotic ionophores. For some representative complexes of these ligands, some details on the environment of the metal coordination and structural characteristics are described. PMID:26860299

  12. Computer aided drug discovery of highly ligand efficient, low molecular weight imidazopyridine analogs as FLT3 inhibitors

    PubMed Central

    Frett, Brendan; McConnell, Nick; Smith, Catherine C.; Wang, Yuanxiang; Shah, Neil P.; Li, Hong-yu

    2015-01-01

    The FLT3 kinase represents an attractive target to effectively treat AML. Unfortunately, no FLT3 targeted therapeutic is currently approved. In line with our continued interests in treating kinase related disease for anti-FLT3 mutant activity, we utilized pioneering synthetic methodology in combination with computer aided drug discovery and identified low molecular weight, highly ligand efficient, FLT3 kinase inhibitors. Compounds were analyzed for biochemical inhibition, their ability to selectively inhibit cell proliferation, for FLT3 mutant activity, and preliminary aqueous solubility. Validated hits were discovered that can serve as starting platforms for lead candidates. PMID:25765758

  13. High and low molecular weight tracers for the electron microscopical detection of sialoglycoconjugates.

    PubMed

    Mureşan, V; Simionescu, N

    1987-03-01

    Hydrazide-derivative tracers of different molecular weights have been synthesized for use in the electron microscopical detection of sodium periodate-oxidized sialyl residues of glycoconjugates in various tissues and cells. Haemundecapeptide hydrazide, horseradish peroxidase hydrazide, and Limulus polyphemus haemocyanin hydrazide were obtained by coupling adipic acid dihydrazide to the tracers with the aid of water-soluble carbodiimide. The enzymatic tracers thus prepared retained their peroxidatic activity. On conversion to the hydrazide derivative, the haemocyanin molecule dissociated into its hexameric subunits. In order to test by transmission electron microscopy the ability of the conjugates to bind to the sialoglycoconjugates of endothelial cell surfaces, each tracer was perfused in situ into rat pancreatic vasculature previously oxidized with 1 mM sodium periodate. The three tracers characteristically labelled the various microdomains of the luminal cell coat of the capillary endothelial cell. The electron opacity of the haemocyanin subunits allowed their easy detection when bound to the cell surface or to components of the extracellular matrix. The bound markers were not displaced by a high ionic strength buffer, and did not label desialylated cell surfaces. These results indicate that the three hydrazide-derivative tracers may be useful tools for the electron microscopical detection of cellular and extracellular sialoglycoconjugates. PMID:3597134

  14. Freezing tolerance and low molecular weight cryoprotectants in an invasive parasitic fly, the deer ked (Lipoptena cervi).

    PubMed

    Nieminen, Petteri; Paakkonen, Tommi; Eerilä, Harri; Puukka, Katri; Riikonen, Joakim; Lehto, Vesa-Pekka; Mustonen, Anne-Mari

    2012-01-01

    Insect cold hardiness is often mediated by low molecular weight cryoprotectants, such as sugars, polyols, and amino acids (AA). While many free-living northern insects must cope with extended periods of freezing ambient temperatures (Ta), the ectoparasitic deer ked Lipoptena cervi imago can encounter subfreezing Ta only during a short autumnal period between hatching and host location. Subsequently, it benefits from the body temperature of the cervid host for survival in winter. This study investigated the cold tolerance of the species by determining its lower lethal temperature (100% mortality, LLT100) during faster and slower cold acclimation, by determining the supercooling point (SCP) and by measuring the concentrations of potential low molecular weight cryoprotectants. The LLT100 of the deer ked was approximately -16 ° C, which would enable it to survive freezing nighttime Ta not only in its current area of distribution but also further north. The SCP was -7.8 ° C, clearly higher than the LLT100 , indicating that the deer ked displays freezing tolerance. The concentrations of free AA, especially nonessential AA, were higher in the cold-acclimated deer keds similar to several other insects. The concentrations of proline increased together with γ-aminobutyrate, arginine, asparagine, cystine, glutamate, glutamine, hydroxylysine, sarcosine, serine, and taurine. AA could be hypothesized to act as cryoprotectants by, e.g., protecting enzymes and lipid membranes from damage caused by cold. PMID:22076947

  15. Freezing tolerance and low molecular weight cryoprotectants in an invasive parasitic fly, the deer ked (Lipoptena cervi).

    PubMed

    Nieminen, Petteri; Paakkonen, Tommi; Eerilä, Harri; Puukka, Katri; Riikonen, Joakim; Lehto, Vesa-Pekka; Mustonen, Anne-Mari

    2012-01-01

    Insect cold hardiness is often mediated by low molecular weight cryoprotectants, such as sugars, polyols, and amino acids (AA). While many free-living northern insects must cope with extended periods of freezing ambient temperatures (Ta), the ectoparasitic deer ked Lipoptena cervi imago can encounter subfreezing Ta only during a short autumnal period between hatching and host location. Subsequently, it benefits from the body temperature of the cervid host for survival in winter. This study investigated the cold tolerance of the species by determining its lower lethal temperature (100% mortality, LLT100) during faster and slower cold acclimation, by determining the supercooling point (SCP) and by measuring the concentrations of potential low molecular weight cryoprotectants. The LLT100 of the deer ked was approximately -16 ° C, which would enable it to survive freezing nighttime Ta not only in its current area of distribution but also further north. The SCP was -7.8 ° C, clearly higher than the LLT100 , indicating that the deer ked displays freezing tolerance. The concentrations of free AA, especially nonessential AA, were higher in the cold-acclimated deer keds similar to several other insects. The concentrations of proline increased together with γ-aminobutyrate, arginine, asparagine, cystine, glutamate, glutamine, hydroxylysine, sarcosine, serine, and taurine. AA could be hypothesized to act as cryoprotectants by, e.g., protecting enzymes and lipid membranes from damage caused by cold.

  16. Low molecular weight polyethylenimine grafted N-maleated chitosan for gene delivery: properties and in vitro transfection studies.

    PubMed

    Lu, Bo; Xu, Xiao-Ding; Zhang, Xian-Zheng; Cheng, Si-Xue; Zhuo, Ren-Xi

    2008-10-01

    To develop chitosan-based efficient gene vectors, chitosans with different molecular weights were chemically modified with low molecular weight polyethylenimine. The molecular weight and composition of polyethylenimine grafted N-maleated chitosan (NMC-g-PEI) copolymers were characterized using gel permeation chromatography (GPC) and (1)H NMR, respectively. Agarose gel electrophoresis assay showed that NMC-g-PEI had good binding ability with DNA, and the particle size of the NMC-g-PEI/DNA complexes was 200-400 nm, as determined by a Zeta sizer. The nanosized complexes observed by scanning electron microscopy (SEM) exhibited a compact and spherical morphology. The NMC-g-PEI copolymers showed low cytotoxicity and good transfection activity, comparable to PEI (25 KDa) in both 293T and HeLa cell lines, except for NMC 50K-g-PEI. The results indicated that the molecular weight of NMC-g-PEI has an important effect on cytotoxicity and transfection activity, and low molecular weight NMC-g-PEI has a good potential as efficient nonviral gene vectors.

  17. [Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

    PubMed

    Xie, Li; Chen, Ben-shou; Zhang, Jin-zhong; Lu, Song; Jiang, Tao

    2016-03-15

    The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content. PMID:27337897

  18. [Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

    PubMed

    Xie, Li; Chen, Ben-shou; Zhang, Jin-zhong; Lu, Song; Jiang, Tao

    2016-03-15

    The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content.

  19. The geochemical evolution of low-molecular-weight organic acids derived from the degradation of petroleum contaminants in groundwater

    USGS Publications Warehouse

    Cozzarelli, I.M.; Baedecker, M.J.; Eganhouse, R.P.; Goerlitz, D.F.

    1994-01-01

    The geochemical evolution of low-molecular-weight organic acids in groundwater downgradient from a crude-oil spill near Bemidji, Minnesota, was studied over a five year period (1986-1990). The organic acids are metabolic intermediates of the degradation of components of the crude oil and are structurally related to hydrocarbon precursors. The concentrations of organic acids, particularly aliphatic acids, increase as the microbial alteration of hydrocarbons progresses. The organic-acid pool changes in composition and concentration over time and in space as the degradation processes shift from Fe(III) reduction to methanogenesis. Over time, the aquifer system evolves into one in which the groundwater contains more oxidized products of hydrocarbon degradation and the reduced forms of iron, manganese, and nitrogen. Laboratory microcosm experiments with aquifer material support the hypothesis that organic acids observed in the groundwater originate from the microbial degradation of aromatic hydrocarbons under anoxic conditions. The geochemistry of two other shallow aquifers in coastal plain sediments, one contaminated with creosote waste and the other with gasoline, were compared to the Bemidji site. The geochemical evolution of the low-molecular-weight organic acid pool in these systems is controlled, in part, by the presence of electron acceptors available for microbially mediated electron-transfer reactions. The depletion of electron acceptors in aquifers leads to the accumulation of aliphatic organic acids in anoxic groundwater. ?? 1994.

  20. Characterization of low-molecular-weight hyaluronic acid-based hydrogel and differential stem cell responses in the hydrogel microenvironments.

    PubMed

    Kim, Jungju; Park, Yongdoo; Tae, Giyoong; Lee, Kyu Back; Hwang, Chang Mo; Hwang, Soon Jung; Kim, In Sook; Noh, Insup; Sun, Kyung

    2009-03-15

    Hyaluronic acid is a natural glycosaminoglycan involved in biological processes. Low-molecular-weight hyaluronic acid (10 and 50 kDa)-based hydrogel was synthesized using derivatized hyaluronic acid. Hyaluronic acid was acrylated by two steps: (1) introduction of an amine group using adipic acid dihydrazide, and (2) acrylation by N-acryloxysuccinimide. Injectable hyaluronic acid-based hydrogel was prepared by using acrylated hyaluronic acid and poly(ethylene glycol) tetra-thiols via Michael-type addition reaction. Mechanical properties of the hydrogel were evaluated by varying the molecular weight of acrylated hyaluronic acid (10 and 50 kDa) and the weight percent of hydrogel. Hydrogel based on 50-kDa hyaluronic acid showed the shortest gelation time and the highest complex modulus. Next, human mesenchymal stem cells were cultured in cell-adhesive RGD peptide-immobilized hydrogels together with bone morphogenic protein-2 (BMP-2). Cells cultured in the RGD/BMP-2-incorporated hydrogels showed proliferation rates higher than that of control or RGD-immobilized hydrogels. Real-time RT-PCR showed that the expression of osteoblast marker genes such as CBFalpha1 and alkaline phosphatase was increased in hyaluronic acid-based hydrogel, and the expression level was dependent on the molecular weight of hyaluronic acid, RGD peptide, and BMP-2. This study indicates that low-molecular-weight hyaluronic acid-based hydrogel can be applied to tissue regeneration as differentiation guidance materials of stem cells. PMID:18384163

  1. A novel low molecular weight endo-xylanase from Streptomyces sp. CS628 cultivated in wheat bran.

    PubMed

    Rahman, Md Arifur; Choi, Yun Hee; Pradeep, G C; Choi, Yoon Seok; Choi, Eun Joo; Cho, Seung Sik; Yoo, Jin Cheol

    2014-07-01

    An extracellular low molecular weight xylanase (Xyn628) from Streptomyces sp. CS628 was isolated from Korean soil sample, produced in wheat bran medium, purified, and biochemically characterized. Xyn628 was purified 4.8-fold with a 33.78 % yield using Sepharose CL-6B column chromatography. The purified xylanase was ~18.1 kDa estimated by SDS-PAGE and xylan zymography. N-terminal amino acid sequences of Xyn628 were AYIKEVVSRAYM. The enzyme was found to be stable in a broad range of pH (5.0-13.0) and up to 60 °C and have optimal pH and temperature of pH 11.0 and 60 °C, respectively. Xyn628 activities were remarkable affected by various detergents, chelators, modulators, and metal ions. The xylanase produced xylobiose and xylotriose as principal hydrolyzed end products from the xylan. It was found to degrade agro-waste materials like corn cob and wheat bran by Xyn628 (20 U/g) as shown by electron microscopy. As being simple in purification, low molecular weight, alkaline, thermostable, and ability to produce xylooligosaccharides show that Xyn628 has potential applications in bioindustries as a biobleaching agent or/and xylooligosaccharides production with an appropriate utilization of agro-waste.

  2. Effects of unfractionated heparin, low-molecular-weight heparin, and heparinoid on thromboelastographic assay of blood coagulation.

    PubMed

    Zmuda, K; Neofotistos, D; Ts'ao, C H

    2000-05-01

    Thromboelastography (TEG) has been used increasingly as an intraoperative hemostasis monitoring device. Low-molecular-weight heparins are given increasingly to reduce the development of antibodies against the heparin-platelet factor 4 complex, and heparinoids are given to patients who have developed the antibody. We studied the effect of unfractionated heparin, a low-molecular-weight heparin (enoxaparin sodium [Lovenox]), and a heparinoid (danaparoid sodium [Orgaran]) on blood clotting assayed with TEG (TEG clotting) in vitro and the efficacy of protamine sulfate and heparinase for reversing the effect. Heparin, enoxaparin, and danaparoid all caused a dose-dependent inhibition of TEG clotting of normal blood. Concentrations of enoxaparin and danaparoid that totally inhibited TEG clotting only minimally prolonged the activated partial thromboplastin time. While inhibition of TEG clotting by heparin and enoxaparin was reversed by protamine sulfate and heparinase, inhibition by danaparoid was reversed only by heparinase. Abnormal TEG clotting was observed in patients receiving enoxaparin whose plasma level of the drug was more than 0.1 antiXa U/mL. However, the degree of TEG abnormality did not always coincide with plasma levels of the drug.

  3. Impact of low molecular weight phthalates in inducing reproductive malfunctions in male mice: Special emphasis on Sertoli cell functions.

    PubMed

    Kumar, Narender; Srivastava, Swati; Roy, Partha

    2015-05-01

    Phthalates are commonly used as plasticizers in a variety of products. Since they have been identified as endocrine-disrupting chemicals (EDCs), effect of phthalates on human health is a major concern. In this study, we evaluated individual as well as combined mixture effects of three low molecular weight phthalates on the reproductive system of male mice, specifically on the Sertoli cell structure and function. In order to analyze the blood testes barrier (BTB) dynamics, primary culture of Sertoli cells from 3-weeks old male mice was used for mimicking typical tight junction structures. Male mice were exposed to long-term (45 days) and combined mixture of three phthalates, diethyl phthalate (DEP), diphenyl phthalate (DPP), and dimethyl isophthalate (DMIP) between pre-pubertal to adult stage. Our data showed significant decrease (p < 0.05) in the rates of transcription of certain prominent Sertoli cell specific genes like transferrin, testin and occludin. Moreover, we also observed significant decreases in the expression of proteins like 3β-HSD, connexin-43 and occludin in testicular lysates of treated animals (p < 0.05). The transmission electron microscopic analysis revealed that the test compounds significantly altered the structural integrity of Sertoli cells. The significant changes of Sertoli cell tight junction structure by test compounds were associated with phosphorylation of ERK. Taken together, our study suggests that low molecular weight phthalates may affect male fertility by altering both structural and functional integrity of Sertoli cells in testes.

  4. Sol-gel SELEX circumventing chemical conjugation of low molecular weight metabolites discovers aptamers selective to xanthine.

    PubMed

    Bae, Hyunjung; Ren, Shuo; Kang, Jeehye; Kim, Minjung; Jiang, Yuanyuan; Jin, Moonsoo M; Min, Irene M; Kim, Soyoun

    2013-12-01

    Sensitive detection of the metabolites indicative of a particular disease contributes to improved therapy outcomes. Developing binding reagents for detection of low molecular weight metabolites is hampered by the difficulty with immobilization of targets through appropriate covalent chemical linkage while ensuring that selected reagents retain specificity to unmodified metabolites. To circumvent chemical modification of targets, we employed sol-gel droplets deposited onto a porous silicon chip to entrap a purine metabolite, xanthine, which was found at lower levels in urine samples from patients with non-Hodgkin lymphoma. By sol-gel SELEX (systematic evolution of ligands by exponential enrichment) against xanthine, specific aptamers (KD ∼ 10 μM) with sensitivity of detection at as low as 1 μM were isolated, which bound to other purine metabolites at more than 100-fold lower affinity. In contrast, we failed to isolate xanthine-specific aptamers when SELEX was performed against xanthine covalently linked to polymer resin. This study demonstrates that the sol-gel platform for entrapping low molecular weight metabolites without chemical modifications can be utilized for SELEX to discover aptamers against clinical metabolite markers for diagnosis application.

  5. The effect of self-sorting and co-assembly on the mechanical properties of low molecular weight hydrogels

    NASA Astrophysics Data System (ADS)

    Colquhoun, Catherine; Draper, Emily R.; Eden, Edward G. B.; Cattoz, Beatrice N.; Morris, Kyle L.; Chen, Lin; McDonald, Tom O.; Terry, Ann E.; Griffiths, Peter C.; Serpell, Louise C.; Adams, Dave J.

    2014-10-01

    Self-sorting in low molecular weight hydrogels can be achieved using a pH triggered approach. We show here that this method can be used to prepare gels with different types of mechanical properties. Cooperative, disruptive or orthogonal assembled systems can be produced. Gels with interesting behaviour can be also prepared, for example self-sorted gels where delayed switch-on of gelation occurs. By careful choice of gelator, co-assembled structures can also be generated, which leads to synergistic strengthening of the mechanical properties.Self-sorting in low molecular weight hydrogels can be achieved using a pH triggered approach. We show here that this method can be used to prepare gels with different types of mechanical properties. Cooperative, disruptive or orthogonal assembled systems can be produced. Gels with interesting behaviour can be also prepared, for example self-sorted gels where delayed switch-on of gelation occurs. By careful choice of gelator, co-assembled structures can also be generated, which leads to synergistic strengthening of the mechanical properties. Electronic supplementary information (ESI) available: Full experimental and synthetic details for the dipeptides, full experimental descriptions, further NMR, single crystal diffraction data, fXRD data and SANS data. See DOI: 10.1039/c4nr04039b

  6. A novel low molecular weight endo-xylanase from Streptomyces sp. CS628 cultivated in wheat bran.

    PubMed

    Rahman, Md Arifur; Choi, Yun Hee; Pradeep, G C; Choi, Yoon Seok; Choi, Eun Joo; Cho, Seung Sik; Yoo, Jin Cheol

    2014-07-01

    An extracellular low molecular weight xylanase (Xyn628) from Streptomyces sp. CS628 was isolated from Korean soil sample, produced in wheat bran medium, purified, and biochemically characterized. Xyn628 was purified 4.8-fold with a 33.78 % yield using Sepharose CL-6B column chromatography. The purified xylanase was ~18.1 kDa estimated by SDS-PAGE and xylan zymography. N-terminal amino acid sequences of Xyn628 were AYIKEVVSRAYM. The enzyme was found to be stable in a broad range of pH (5.0-13.0) and up to 60 °C and have optimal pH and temperature of pH 11.0 and 60 °C, respectively. Xyn628 activities were remarkable affected by various detergents, chelators, modulators, and metal ions. The xylanase produced xylobiose and xylotriose as principal hydrolyzed end products from the xylan. It was found to degrade agro-waste materials like corn cob and wheat bran by Xyn628 (20 U/g) as shown by electron microscopy. As being simple in purification, low molecular weight, alkaline, thermostable, and ability to produce xylooligosaccharides show that Xyn628 has potential applications in bioindustries as a biobleaching agent or/and xylooligosaccharides production with an appropriate utilization of agro-waste. PMID:24817510

  7. Low-molecular-weight (4.5S) ribonucleic acid in higher-plant chloroplast ribosomes.

    PubMed Central

    Whitfeld, P R; Leaver, C J; Bottomley, W; Atchison, B

    1978-01-01

    A species of RNA that migrates on 10% (w/v) polyacrylamide gels between 5S and 4S RNA was detected in spinach chloroplasts. This RNA (referred to as 4.5 S RNA) was present in amounts equimolar to the 5S RNA and its molecular weight was estimated to be approx. 33 000. Fractionation of the chloroplast components showed that the 4.5S RNA was associated with the 50 S ribosomal subunit and that it could be removed by washing the ribosomes with a buffer containing 0.01 M-EDTA and 0.5 M-KCl. It did not appear to be a cleavage product of the labile 23 S RNA of spinach chloroplast ribosomes. When 125I-labelled 4.5 S RNA was hybridized to fragments of spinach chloroplast DNA produced by SmaI restriction endonuclease, a single fragment (mol.wt. 1.15 times 10(6)) became labelled. The same DNA fragment also hybridized to chloroplast 5 S RNA and part of the 23 S RNA. It was concluded that the coding sequence for 4.5 S RNA was part of, or immediately adjacent to, the rRNA-gene region in chloroplast DNA . A comparable RNA species was observed in chloroplasts of tobacco and pea leaves. Images Fig. 8. PMID:743229

  8. Regulation of the EphA2 kinase by the low molecular weight tyrosine phosphatase induces transformation.

    PubMed

    Kikawa, Keith D; Vidale, Derika R; Van Etten, Robert L; Kinch, Michael S

    2002-10-18

    Intracellular signaling by protein tyrosine phosphorylation is generally understood to govern many aspects of cellular behavior. The biological consequences of this signaling pathway are important because the levels of protein tyrosine phosphorylation are frequently elevated in cancer cells. In the classic paradigm, tyrosine kinases promote tumor cell growth, survival, and invasiveness, whereas tyrosine phosphatases negatively regulate these same behaviors. Here, we identify one particular tyrosine phosphatase, low molecular weight tyrosine phosphatase (LMW-PTP), which is frequently overexpressed in transformed cells. We also show that overexpression of LMW-PTP is sufficient to confer transformation upon non-transformed epithelial cells. Notably, we show that the EphA2 receptor tyrosine kinase is a prominent substrate for LMW-PTP and that the oncogenic activities of LMW-PTP result from altered EphA2 expression and function. These results suggest a role for LMW-PTP in transformation progression and link its oncogenic potential to EphA2.

  9. Structural Evolution of Low-Molecular-Weight Poly(ethylene oxide)-block-polystyrene Diblock Copolymer Thin Film

    PubMed Central

    Huang, Xiaohua

    2013-01-01

    The structural evolution of low-molecular-weight poly(ethylene oxide)-block-polystyrene (PEO-b-PS) diblock copolymer thin film with various initial film thicknesses on silicon substrate under thermal annealing was investigated by atomic force microscopy, optical microscopy, and contact angle measurement. At film thickness below half of the interlamellar spacing of the diblock copolymer (6.2 nm), the entire silicon is covered by a polymer brush with PEO blocks anchored on the Si substrate due to the substrate-induced effect. When the film is thicker than 6.2 nm, a dense polymer brush which is equal to half of an interlamellar layer was formed on the silicon, while the excess material dewet this layer to form droplets. The droplet surface was rich with PS block and the PEO block crystallized inside the bigger droplet to form spherulite. PMID:24302862

  10. Inhibition of oxidative stress by low-molecular-weight polysaccharides with various functional groups in skin fibroblasts.

    PubMed

    Chen, Szu-Kai; Hsu, Chu-Hsi; Tsai, Min-Lang; Chen, Rong-Huei; Drummen, Gregor P C

    2013-09-25

    The aim of this study was to evaluate the in cellulo inhibition of hydrogen-peroxide-induced oxidative stress in skin fibroblasts using different low-molecular-weight polysaccharides (LMPS) prepared from agar (LMAG), chitosan (LMCH) and starch (LMST), which contain various different functional groups (i.e., sulfate, amine, and hydroxyl groups). The following parameters were evaluated: cell viability, intracellular oxidant production, lipid peroxidation, and DNA damage. Trolox was used as a positive control in order to allow comparison of the antioxidant efficacies of the various LMPS. The experimentally determined attenuation of oxidative stress by LMPS in skin fibroblasts was: LMCH > LMAG > LMST. The different protection levels of these LMPS may be due to the physic-chemical properties of the LMPS' functional groups, including electron transfer ability, metal ion chelating capacities, radical stabilizing capacity, and the hydrophobicity of the constituent sugars. The results suggest that LMCH might constitute a novel and potential dermal therapeutic and sun-protective agent.

  11. Degradation of low molecular weight volatile organic compounds by plants genetically modified with mammalian cytochrome P450 2E1.

    PubMed

    James, C Andrew; Xin, Gang; Doty, Sharon L; Strand, Stuart E

    2008-01-01

    Cytochrome P450 2E1 (CYP2E1) is a key enzyme in the mammalian metabolism of several low molecular weight volatile organic compounds (VOCs), such as trichloroethylene (TCE), vinyl chloride (VC), carbon tetrachloride (CT), benzene, chloroform, and bromodichloromethane (BDCM), which are all common environmental pollutants that pose risks to human health. We have developed a transgenic tobacco (Nicotiana tabacum cv. Xanthii) that expresses CYP2E1 with increased activity toward TCE and ethylene dibromide. In experiments with tobacco plant cuttings exposed to VOCs in small hydroponic vessels, the transgenic tobacco had greatly increased rates of removal of TCE, VC, CT, benzene, toluene, chloroform, and BDCM, compared to wild-type or vector control tobacco, but not of perchloroethylene or 1,1,1-trichloroethane.

  12. Volatile organic compound and formaldehyde emissions from Populus davidiana wood treated with low molecular weight urea-formaldehyde resin.

    PubMed

    Wang, Jing-Xian; Shen, Jun; Lei, Cheng-Shuai; Feng, Qi

    2014-09-01

    Populus davidiana wood was usually impregnated with low molecular weight thermosetting resins to improve its physical and mechanical properties. However, volatile organic compounds (VOCs) and formaldehyde emitted from treated wood have lead to poor indoor air quality (IAQ). The trends of VOC and formaldehyde emissions as a function of the weight percent gain (WPG) factor were mainly investigated in this work. Aldehydes and alkanes were the predominant compositions indentified in the VOC emissions, although low amount of ketones, terpenes and alcohols were also found. With the increase in WPG, VOC and formaldehyde concentrations improved. However, their concentration began to decrease when WPG was over 44.06% (VOC) and 36.35% (formaldehyde), respectively. The modulus of elasticity (MOE) of untreated and treated wood at different WPG levels was detected. It showed that treatment of wood with UF resin significantly improved the mechanical properties. Therefore, it is probably helpful to comprehensively analyze correlations among environmental performance, mechanical performance and processing costs.

  13. Coating compositions for solar selective absorption comprising a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon polymer

    SciTech Connect

    Maki, M.; Fukuda, H.; Sano, S.

    1984-01-17

    A coating composition for solar selective absorption comprising, in solvent, particles of an inorganic black pigment dispersed in a dissolved binder of a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon resin contained in an amount of 5-15 parts by weight per 100 parts by weight of the acrylic resin. The inorganic black particles have a size of 0.01-0.5 microns and are contained in an amount of 45-65 parts by weight per 100 parts by weight of the acrylic resin. An article having a metal substrate and a paint film formed thereon from the composition in a dry thickness of 1.5 microns or more is also described.

  14. In Vivo Anti-Cancer Mechanism of Low-Molecular-Weight Fucosylated Chondroitin Sulfate (LFCS) from Sea Cucumber Cucumaria frondosa.

    PubMed

    Liu, Xiaoxiao; Liu, Yong; Hao, Jiejie; Zhao, Xiaoliang; Lang, Yinzhi; Fan, Fei; Cai, Chao; Li, Guoyun; Zhang, Lijuan; Yu, Guangli

    2016-01-01

    The low-molecular-weight fucosylated chondroitin sulfate (LFCS) was prepared from native fucosylated chondroitin sulfate (FCS), which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC) was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF), increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and downregulated the matrix metalloproteinases (MMPs) level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study. PMID:27187337

  15. [The use of enzymatic preparation for the production of low molecular-weight chitosan from the king crab hepatopancrease].

    PubMed

    Il'ina, A V; Zagorskaia, D S; Levov, A N; Albulov, A I; Kovacheva, N P; Varlamov, V P

    2009-01-01

    This article describes the optimal conditions for the enzymatic hydrolysis of chitosan and its chemically-modified derivatives using the preparation extracted from the king crab hepatopancrease possessing pronounced hydrolythic activity. The following preparations were used: chitosan with a molecular weight of 100 kDa and an acetylation level of 0.15, carboxymethyl chitosan 200 kDa witih an extent of replacement of 0.23, and N-succinyl chitosan 390 kDa with an extent of replacement of 0.8. Low molecular-weight samples of chitosan and of its modified derivatives were obtained with the yields of 85, 55, and 80%, respectively. The conditions of the hydrolysis were as follows: an enzyme: substrate ratio of 1:200, 37 degrees C, and 20 h duration of hydrolysis.

  16. Turning low-molecular-weight drugs into prolonged acting prodrugs by reversible pegylation: a study with gentamicin.

    PubMed

    Marcus, Yonit; Sasson, Keren; Fridkin, Mati; Shechter, Yoram

    2008-07-24

    Pegylation is a powerful technology to prolong the action of proteins in vivo, but it is impractical for low-molecular-weight (LMW) drugs, which are usually inactivated upon such modification. Here, we have applied a recently developed strategy of reversible pegylation to gentamicin, a LMW antibiotic. Variable length polyethyleneglycol (PEG-SH) chains were covalently linked to gentamicin using two heterobifunctional agents, each containing a spontaneously hydrolyzable bond. The inactive derivatives regained full antibacterial potency upon incubation under physiological conditions in vitro, and following systemic administration to rats, they released native active gentamicin with half-lives 7- to 15-fold greater than those of systemically administered nonderivatized gentamicin. In conclusion, reversibly pegylated prodrug derivatives of gentamicin were found to be capable of releasing gentamicin for prolonged periods in vivo. Most importantly, the major drawback of conventional pegylation, namely, the loss of pharmacological potency following irreversible derivatization, has been overcome.

  17. In Vivo Anti-Cancer Mechanism of Low-Molecular-Weight Fucosylated Chondroitin Sulfate (LFCS) from Sea Cucumber Cucumaria frondosa.

    PubMed

    Liu, Xiaoxiao; Liu, Yong; Hao, Jiejie; Zhao, Xiaoliang; Lang, Yinzhi; Fan, Fei; Cai, Chao; Li, Guoyun; Zhang, Lijuan; Yu, Guangli

    2016-01-01

    The low-molecular-weight fucosylated chondroitin sulfate (LFCS) was prepared from native fucosylated chondroitin sulfate (FCS), which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC) was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF), increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and downregulated the matrix metalloproteinases (MMPs) level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study.

  18. The major low-molecular-weight heat shock protein in chloroplasts shows antigenic conservation among diverse higher plant species.

    PubMed

    Vierling, E; Harris, L M; Chen, Q

    1989-02-01

    Several plant species are known to synthesize low-molecular-weight nucleus-encoded heat shock proteins (HSPs) which localize to chloroplasts. DNA sequence analysis of chloroplast HSP cDNAs from pea (Pisum sativum) and soybean (Glycine max) has shown that the carboxyl-terminal halves of these proteins are homologous to low-molecular-weight HSPs from a wide range of eucaryotes (E. Vierling, R. T. Nagao, A. E. DeRocher, and L. M. Harris, EMBO J. 7:575-581, 1988). We used a pea cDNA to construct fusion proteins containing either the carboxyl-terminal heat shock domain or the amino-terminal domain of the chloroplast HSP. The fusion proteins were overexpressed in Escherichia coli and used to produce choloroplast HSP-specific polyclonal antibodies. The carboxyl-terminal antibodies recognized chloroplast HSP precursor proteins from pea and from three divergent plant species, Arabidopsis thaliana, petunia (Petunia hybrida), and maize (Zea mays). The amino-terminal antibodies recognized effectively only the pea precursor. When intact plants of each species were subjected to a heat stress regime mimicking field growth conditions, significant levels of the mature forms of the chloroplast HSPs accumulated in pea, A. thaliana, and maize. The levels of accumulated HSPs remained unchanged for 12 h following the stress treatment. We conclude that the synthesis of chloroplast-localized HSPs is an important component of the stree response in all higher plants and that chloroplast HSPs from dicotyledonous and monocotyledonous plants have a conserved carboxyl-terminal domain.

  19. 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

  20. Dissolved low-molecular weight thiol concentrations from the U.S. GEOTRACES North Atlantic Ocean zonal transect

    NASA Astrophysics Data System (ADS)

    Swarr, Gretchen J.; Kading, Tristan; Lamborg, Carl H.; Hammerschmidt, Chad R.; Bowman, Katlin L.

    2016-10-01

    Low-molecular weight thiols, including cysteine and glutathione, are biomolecules involved in a variety of metabolic pathways and act as important antioxidant and metal buffering agents. In this last capacity, they represent a potential mechanism for modulating the bioavailability and biogeochemistry of many trace elements in the ocean, particularly for chalcophilic elements (e.g., Cu, Zn, Cd, Ag and Hg). For this reason, and in the context of the international GEOTRACES program that seeks to understand the biogeochemistry of trace elements in the ocean, we measured the concentration of individual dissolved low-molecular weight thiols during the U.S. GEOTRACES North Atlantic Zonal Transect (USGNAZT). Only two thiols were identified, cysteine and glutathione, in contrast to results from the northeast subarctic Pacific Ocean, where the dipeptides glycine-cysteine and arginine-cysteine were also present and γ-glutamylcysteine was dominant. Concentrations of cysteine and glutathione in the North Atlantic Ocean were lower than in the Pacific and ranged from below detection ( 0.01 nM) to 0.61 nM of cysteine and up to 1.0 nM of glutathione, with cysteine generally more abundant than glutathione. Vertical profiles of cysteine and glutathione were broadly consistent with their biological production, being more abundant in surface water and usually below detection at depths greater than about 200 m. Subsurface concentration maxima, often co-incident with the deep chlorophyll maximum, were frequently observed but not universal. We conclude that cysteine and glutathione do not make up significant portions of complexation capacity for Cu and Zn in the upper open ocean but could be important for Cd, Hg, and potentially other chalcophiles. Extremely low concentrations of cysteine and glutathione in deep water suggest that higher molecular-weight thiols are a more important ligand class for chalcophiles in that portion of the ocean.

  1. Effect of in vivo and in vitro degradation on molecular and mechanical properties of various low-molecular-weight polylactides.

    PubMed

    Mainil-Varlet, P; Curtis, R; Gogolewski, S

    1997-09-01

    The in vivo and in vitro degradation of low-molecular-weight poly(L-lactide), poly(L/D-lactide), and poly (L/DL-lactide) rods was investigated. The low-molecular-weight fast-degrading materials were used to accelerate the degradation process and make the test conditions more critical. In the in vivo study the rods were implanted in the soft tissue of sheep and explanted at 1, 3, 6, and 12 months. In the in vitro experiments the samples were subjected to aging at 37 degrees C in the phosphate buffer using two different modes. In the so-called pseudodynamic mode the aging buffer was regularly replaced if the pH dropped more than 0.5. In the static mode the buffer was not changed over the whole testing period of 52 weeks. The mechanical, molecular, and crystalline properties of the rods were measured and their appearance in the course of aging was evaluated using scanning electron microscopy. It was found that the changes in the mechanical properties of poly(L-lactide), poly(L/D-lactide), and poly(L/DL-lactide) samples subjected to in vitro degradation tests in both the static and pseudodynamic modes are in good approximation with data obtained from the in vivo study. The pH of the buffer solution had no evident effect on the mechanical properties or the rate of degradation as estimated from the drop in molecular weight of the aged samples. The replacement of the aging buffer to maintain a constant pH at 7.4 does not seem to be critical for the degradation of the polylactides. In vitro degradation tests can be used as a relevant procedure for predicting the in vivo functionality of implants from the polylactides used if the criteria for assessing such a functionality are the changes in mechanical properties and molecular weight.

  2. [Significance of low molecular weight urinary protein for assessment of early renal damage in patients with multiple myeloma].

    PubMed

    Liu, Shi-Jing; Zhai, Yong-Ping; Yu, Ya-Ping; Liu, Hai-Ning; Li, Feng; Song, Ping; Zhou, Xiao-Gang; An, Zhi-Ming; Shao, Jing-Jing; Yang, Xiao-Yan

    2013-04-01

    This study was purposed to evaluate the clinical significance of low molecular weight urinary proteins for diagnosis of early renal damage in patients with multiple myeloma (MM). Medical records of 278 patients with MM in Nanjing School of Clinical Medicine from January 2004 to May 2012 were analyzed retrospectively. These patients were divided into 3 groups: glomerular damage group (n = 143), tubular damage group (n = 114) and normal group (n = 21). The clinical and laboratorial data were compared among them. The correlations of urinary retinol-binding protein (RBP) or urinary N-acetyl-β-D-amino-glucosaminidase (NAG) with blood urea nitrogen (BUN), Scr, blood cystatin-C (Cys-C), clearance of creatinine (Ccr), 24 h protein uria and 24 h urine light chains were further analyzed, and the correlation of renal tubulointerstitial lesion scores with low molecular weight urinary proteins in 61 patients were also analyzed. The area under curve (ROC curve) was used to evaluate and compare the discrimination of urinary RBP and urinary NAG. The results showed that glomerular damage group had higher urinary RBP than tubular damage group. However, glomerular damage group had lower urinary NAG than tubular damage group. The two groups had higher urinary RBP and urinary NAG than that in normal group. Urinary RBP related positively to the level of Scr, BUN, Cys-C, 24 h proteinurias and related negatively to the level of Ccr. Urinary NAG related positively to the level of 24 h proteinurias, Ccr and related negatively to the level of Cys-C. Renal tubulointerstitial lesions were significantly correlated with urinary RBP, but weakly correlated with urinary NAG. It is concluded that urinary RBP significantly correlates with renal tubular damage. Compared with urinary NAG, urinary RBP can better assess the extent of renal damage, and has higher specificity.

  3. Inhibition of lipase-catalyzed hydrolysis of emulsified triglyceride oils by low-molecular weight surfactants under simulated gastrointestinal conditions.

    PubMed

    Li, Yan; McClements, David Julian

    2011-10-01

    The effect of low-molecular weight surfactants on the digestibility of lipids in protein-stabilized corn oil-in-water emulsions was studied using an in vitro digestion model. The impact of non-ionic (Tween 20, Tween 80, Brij35), anionic (SDS), and cationic (DTAB) surfactants on the rate and extent of lipid digestion was studied. All surfactants were found to inhibit lipid digestion at sufficiently high concentrations, with half-maximal inhibitory concentrations (IC50) of 1.2% for Tween 20, 0.7% for Tween 80, 2.8% for Brij35, 1.1% for SDS, and 1.4% for DTAB. The effectiveness of the surfactants at inhibiting lipid digestion was therefore not strongly correlated to the electrical characteristics of the surfactant head group, since the IC50 increased in the following order: Tween 80>SDS>Tween 20>DTAB>Brij35. The ability of these low-molecular weight surfactants to inhibit lipid digestion was attributed to a number of potential mechanisms: (i) prevention of lipase/co-lipase adsorption to the oil-water interface; (ii) formation of interfacial complexes; (iii) direct interaction and inactivation of lipase/co-lipase. Interestingly, DTAB increased the rate and extent of lipid digestion when present at relatively low concentrations. This may have been because this cationic surfactant facilitated the adsorption of lipase to the droplet surfaces through electrostatic attraction, or it bound directly to the lipase molecule thereby changing its structure and activity. A number of the surfactants themselves were found to be susceptible to enzyme digestion by pancreatic enzymes in the absence of lipids: Tween 20, Tween 80, Brij35, and DTAB. This work has important implications for the development of emulsion-based delivery systems for food and pharmaceutical applications.

  4. Mineral Dissolution and Metal Mobility From Rhizosphere and Non-rhizosphere Soils by Low Molecular Weight Organic Acids

    NASA Astrophysics Data System (ADS)

    Little, D. A.; Field, J. B.; Welch, S. A.

    2005-12-01

    This research is part of an ongoing investigation of micro-biogeochemistry in the rhizosphere of co-occurring Eucalyptus mannifera and Acacia falciformis on the Southern Tablelands of New South Wales, Australia. While there is still considerable controversy in the literature regarding the roles of low molecular weight organic acids in soil processes there is growing evidence suggesting low molecular weight compounds, especially di-carboxylic acids, have large impacts on mineral dissolution and metal mobility in the rhizosphere. Rhizosphere and non-rhizosphere samples from adjacent E. mannifera and A. falciformis trees were subjected to four separate treatments in sets of 3 replicates; +oxalic acid, +malic acid, +citric acid or +NaCl control solution. These three acids were chosen because they are produced by rhizosphere species and they form stable complexes with nutrient elements such as Phosphorus (P), Iron (Fe), and Calcium (Ca). Solution samples were collected at day 1, day 8 and day 15 for pH measurement and analysed for major and trace elements by ICP-AES and ICP-MS. The results of the preliminary dissolution experiments show that milli-molar concentrations of individual organic acids, malate and oxalate, and in particular citrate, greatly increase the release of major and trace metals to solution compared to inorganic controls. Concentrations of Al and Fe in organic acid solutions were up to 10 times greater than in the inorganic controls. Si concentrations were a factor of 2-5 greater in the organic acid solutions, suggesting preferential weathering of Fe and Al oxyhydroxide phases rather than primary silicate minerals. Dissolution of elements such as Si, Al and Fe from rhizosphere soils were about twice that observed from non-rhizosphere soils, further supporting this. Interestingly Ti and Zr, which are usually considered to be immobile during chemical weathering and are not usually taken up by plants, were also mobilised from the rhizosphere soils

  5. 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

  6. Comparison of efficacy and safety of low molecular weight heparins and unfractionated heparin in initial treatment of deep venous thrombosis: a meta-analysis.

    PubMed Central

    Leizorovicz, A.; Simonneau, G.; Decousus, H.; Boissel, J. P.

    1994-01-01

    OBJECTIVE--To compare the efficacy and safety of low molecular weight heparins and unfractionated heparin in the initial treatment of deep venous thrombosis for the reduction of recurrent thromboembolic events, death, extension of thrombus, and haemorrhages. DESIGN--Meta-analysis of results from 16 randomised controlled clinical studies. SUBJECTS--2045 patients with established deep venous thrombosis. INTERVENTION--Treatment with low molecular weight heparins or unfractionated heparin. MAIN OUTCOME MEASURES--Incidences of thromboembolic events (deep venous thrombosis or pulmonary embolism, or both); major haemorrhages; total mortality; and extension of thrombus. RESULTS--A significant reduction in the incidence of thrombus extension (common odds ratio 0.51, 95% confidence interval 0.32 to 0.83; P = 0.006) in favour of low molecular weight heparin was observed. Non-significant trends also in favour of the low molecular weight heparins were observed for the recurrence of thromboembolic events (0.66, 0.41 to 1.07; P = 0.09), major haemorrhages (0.65, 0.36 to 1.16; P = 0.15), and total mortality (0.72, 0.46 to 1.4; P = 0.16). CONCLUSIONS--Low molecular weight heparins seem to have a higher benefit to risk ratio than unfractionated heparin in the treatment of venous thrombosis. These results, however, remain to be confirmed by using clinical outcomes in suitably powered clinical trials. PMID:8086867

  7. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis

    PubMed Central

    Li, Lian; Li, Yan; Feng, Danyang; Xu, Linghua; Yin, Fengxin; Zang, Hengchang; Liu, Chunhui; Wang, Fengshan

    2016-01-01

    Chondroitin sulfate (CS) plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs) and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV) spectroscopy, high-performance liquid chromatography (HPLC), size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O) had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA) was investigated by destabilization of the medial meniscus (DMM) model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system. PMID:27727159

  8. 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

  9. Prophylaxis of venous thromboembolism: low molecular weight heparin compared to the selective anticoagulants rivaroxaban, dabigatran and fondaparinux.

    PubMed

    Welzel, D; Hull, R; Fareed, J

    2011-06-01

    Newer therapeutic options available in the prevention of postoperative thromboembolism, currently focused on fondaparinux, rivaroxaban and dabigatran warrant an overall therapeutic assessment. The constitutive comparisons with enoxaparin are based on a combined outcome measure solely driven by the incidence of "asymptomatic deep vein thrombosis". Its validity as a clinically relevant endpoint is missing if antithrombotics of different classes are compared. This is because they target different phases of thrombogenesis i. e. ahead and beyond the asymptomatic stage of thrombosis. Additional concerns refer to the dosing-regimens and their practical administration: Fondaparinux, rivaroxaban and dabigatran are dosed to achieve maximum effects very close to their limits of tolerance whereas wide dosing spectra for the low molecular weight herparin (LMWH)'s indicate the potential for dose adaptation and increase. The other disadvantage to the control-heparin originates in the timing for the 1st administration which doesn't fit in with the "just-in-time" principle. So the enoxaparin-regimen is lacking in benchmark-quality - with the consequence that the meaning of the Phase III-trials does'nt go beyond a mere technical demarcation from the marketed variant of the product as defined by the stipulations in the package insert. As to tolerance the selective anticoagulants exhibit an increased risk of major and other clinically relevant bleeding, exceeding that of enoxaparin by 30% (P<0.001). The outcome of the meta-analyses on fondaparinux, rivaroxaban and dabigatran is supported by product-specific calculations and assessments of the European Medicine Equivalence Agency (EMEA). Rivaroxaban and dabigatran show significant age-dependent renal accumulation. Because the dose-finding studies were restricted to patients over 60 year old the regimens definitely established are not applicable to younger patients. The reason for the limited therapeutic index of the selective

  10. Preparation of the different derivatives of the low-molecular-weight porphyran from Porphyra haitanensis and their antioxidant activities in vitro.

    PubMed

    Zhang, Zhongshan; Zhang, Quanbin; Wang, Jing; Zhang, Hong; Niu, Xizhen; Li, Pengcheng

    2009-07-01

    Porphyran extracted from Porphyra haitanensis is a sulfated polysaccharide, which possesses excellent antioxidant activities. In this study, we prepared one low-molecular-weight porphyran and its sulfated, acetylated, phosphorylated and benzoylated derivatives. Their antioxidant activities were investigated including scavenging effect of superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals. The results of chemical analysis and FT-IR spectrums showed the modification was successful. And in addition, we found that certain derivative exhibited stronger antioxidant activity than low-molecular-weight porphyran. The benzoylated derivative showed the most excellent antioxidant activity in three assays, so this derivative needs to be attended to.

  11. Development of gel-filter method for high enrichment of low-molecular weight proteins from serum.

    PubMed

    Chen, Lingsheng; Zhai, Linhui; Li, Yanchang; Li, Ning; Zhang, Chengpu; Ping, Lingyan; Chang, Lei; Wu, Junzhu; Li, Xiangping; Shi, Deshun; Xu, Ping

    2015-01-01

    The human serum proteome has been extensively screened for biomarkers. However, the large dynamic range of protein concentrations in serum and the presence of highly abundant and large molecular weight proteins, make identification and detection changes in the amount of low-molecular weight proteins (LMW, molecular weight ≤ 30kDa) difficult. Here, we developed a gel-filter method including four layers of different concentration of tricine SDS-PAGE-based gels to block high-molecular weight proteins and enrich LMW proteins. By utilizing this method, we identified 1,576 proteins (n = 2) from 10 μL serum. Among them, 559 (n = 2) proteins belonged to LMW proteins. Furthermore, this gel-filter method could identify 67.4% and 39.8% more LMW proteins than that in representative methods of glycine SDS-PAGE and optimized-DS, respectively. By utilizing SILAC-AQUA approach with labeled recombinant protein as internal standard, the recovery rate for GST spiked in serum during the treatment of gel-filter, optimized-DS, and ProteoMiner was 33.1 ± 0.01%, 18.7 ± 0.01% and 9.6 ± 0.03%, respectively. These results demonstrate that the gel-filter method offers a rapid, highly reproducible and efficient approach for screening biomarkers from serum through proteomic analyses.

  12. Mathematically combined half-cell reduction potentials of low-molecular-weight thiols as markers of seed ageing.

    PubMed

    Birtić, Simona; Colville, Louise; Pritchard, Hugh W; Pearce, Stephen R; Kranner, Ilse

    2011-09-01

    The half-cell reduction potential of the glutathione disulphide (GSSG)/glutathione (GSH) redox couple appears to correlate with cell viability and has been proposed to be a marker of seed viability and ageing. This study investigated the relationship between seed viability and the individual half-cell reduction potentials (E(i)s) of four low-molecular-weight (LMW) thiols in Lathyrus pratensis seeds subjected to artificial ageing: GSH, cysteine (Cys), cysteinyl-glycine (Cys-Gly) and γ-glutamyl-cysteine (γ-Glu-Cys). The standard redox potential of γ-Glu-Cys was previously unknown and was experimentally determined. The E(i)s were mathematically combined to define a LMW thiol-disulphide based redox environment (E(thiol-disulphide)). Loss of seed viability correlated with a shift in E(thiol-disulphide) towards more positive values, with a LD(50) value of -0.90 ± 0.093 mV M (mean ± SD). The mathematical definition of E(thiol-disulphide) is envisaged as a step towards the definition of the overall cellular redox environment, which will need to include all known redox-couples.

  13. The role of root exuded low molecular weight organic anions in facilitating petroleum hydrocarbon degradation: current knowledge and future directions.

    PubMed

    Martin, Belinda C; George, Suman J; Price, Charles A; Ryan, Megan H; Tibbett, Mark

    2014-02-15

    Rhizoremediation is a bioremediation technique whereby enhanced microbial degradation of organic contaminants occurs within the plant root zone (rhizosphere). It is considered an effective and affordable 'green technology' for remediating soils contaminated with petroleum hydrocarbons (PHCs). This paper critically reviews the potential role of root exuded compounds in rhizoremediation, with emphasis on commonly exuded low molecular weight aliphatic organic acid anions (carboxylates). The extent to which remediation is achieved shows wide disparity among plant species. Therefore, plant selection is crucial for the advancement and widespread adoption of this technology. Root exudation is speculated to be one of the predominant factors leading to microbial changes in the rhizosphere and thus the potential driver behind enhanced petroleum biodegradation. Carboxylates can form a significant component of the root exudate mixture and are hypothesised to enhance petroleum biodegradation by: i) providing an easily degradable energy source; ii) increasing phosphorus supply; and/or iii) enhancing the contaminant bioavailability. These differing hypotheses, which are not mutually exclusive, require further investigation to progress our understanding of plant-microbe interactions with the aim to improve plant species selection and the efficacy of rhizoremediation.

  14. Anti-HCV effect of Lentinula edodes mycelia solid culture extracts and low-molecular-weight lignin.

    PubMed

    Matsuhisa, Koji; Yamane, Seiji; Okamoto, Toru; Watari, Akihiro; Kondoh, Masuo; Matsuura, Yoshiharu; Yagi, Kiyohito

    2015-06-19

    Lentinula edodes mycelia solid culture extract (MSCE) contains several bioactive molecules, including some polyphenolic compounds, which exert immunomodulatory, antitumor, and hepatoprotective effects. In this study, we examined the anti-hepatitis C virus (HCV) activity of MSCE and low-molecular-weight lignin (LM-lignin), which is the active component responsible for the hepatoprotective effect of MSCE. Both MSCE and LM-lignin inhibited the entry of two HCV pseudovirus (HCVpv) types into Huh7.5.1 cells. LM-lignin inhibited HCVpv entry at a lower concentration than MSCE and inhibited the entry of HCV particles in cell culture (HCVcc). MSCE also inhibited HCV subgenome replication. LM-lignin had no effect on HCV replication, suggesting that MSCE contains additional active substances. We demonstrate here for the first time the anti-HCV effects of plant-derived LM-lignin and MSCE. The hepatoprotective effect of LM-lignin suggests that lignin derivatives, which can be produced in abundance from existing plant resources, may be effective in the treatment of HCV-related diseases.

  15. Identification, content and distribution of anthocyanins and low molecular weight anthocyanin-derived pigments in Spanish commercial red wines.

    PubMed

    Blanco-Vega, Dora; Gómez-Alonso, Sergio; Hermosín-Gutiérrez, Isidro

    2014-09-01

    The content and distribution of low molecular weight red wine pigments (anthocyanins, flavanol-anthocyanins adducts and pyranoanthocyanins) has been analysed in 283 wine samples. A total of 90 red wine pigments were identified and up to 68 of them quantified in most of the wine samples. The content of the different pigments classes accounted for wide ranges of values, because of the diversity of the commercial wines regarding grape cultivar and age. Garnacha young wines were prone to contain higher hydroxyphenyl-pyranoanthocyanin concentrations. The aging had an effect of making uniform the concentrations and molar percentages of every type of pigments, and only slight differences among wine groups were found for B-type vitisins (highest values for Syrah wines) and 10-hydroxyphenyl-pyranoanthocyanins (highest values for Merlot wines). Among Tempranillo wines, the ethylidene-bridged flavanol-anthocyanin adducts were the most affected by disappearance during aging, whereas hydroxyphenyl-pyranoanthocyanins increased their contribution in most of those aged wines.

  16. Low molecular weight chitosan-coated polymeric nanoparticles for sustained and pH-sensitive delivery of paclitaxel

    PubMed Central

    Abouelmagd, Sara A.; Ku, Youn Jin; Yeo, Yoon

    2015-01-01

    Low molecular weight chitosan (LMWC) is a promising polymer for surface modification of nanoparticles (NPs), which can impart both stealth effect and electrostatic interaction with cells at mildly acidic pH of tumors. We previously produced LMWC-coated NPs via covalent conjugation to poly(lactic-co-glycolic) acid (PLGA-LMWC NPs). However, this method had several weaknesses including inefficiency and complexity of the production as well as increased hydrophilicity of the polymer matrix, which led to poor drug release control. Here, we used the dopamine polymerization method to produce LMWC-coated NPs (PLGA-pD-LMWC NPs), where the core NPs were prepared with PLGA that served best to load and retain drugs and then functionalized with LMWC via polydopamine layer. The PLGA-pD-LMWC NPs overcame the limitations of PLGA-LMWC NPs while maintaining their advantages. First of all, PLGA-pD-LMWC NPs attenuated the release of paclitaxel to a greater extent than PLGA-LMWC NPs. Moreover, PLGA-pD-LMWC NPs had a pH-dependent surface charge profile and cellular interactions similar to PLGA-LMWC NPs, enabling acid-specific NP-cell interaction and enhanced drug delivery to cells in weakly acidic environment. Although the LMWC layer did not completely prevent protein binding in serum solution, PLGA-pD-LMWC NPs showed less phagocytic uptake than bare PLGA NPs. PMID:26453168

  17. 14-3-3 protein binds to the low molecular weight neurofilament (NFL) mRNA 3' UTR.

    PubMed

    Ge, Wei-Wen; Volkening, Kathryn; Leystra-Lantz, Cheryl; Jaffe, Howard; Strong, Michael J

    2007-01-01

    We have previously reported that altered stability of low molecular weight neurofilament (NFL) mRNA in lumbar spinal cord homogenates in amyotrophic lateral sclerosis (ALS) is associated with altered expression of trans-acting 3' UTR mRNA binding proteins. We have identified two hexanucleotide motifs as the main cis elements and, using LC/MS/MS of peptide digests of NFL 3' UTR interacting proteins from human spinal cord, observed that 14-3-3 proteins interact with these motifs. 14-3-3 beta, zeta, tau, gamma, and eta isoforms were found to be expressed in human spinal cord. Each isoform was expressed in vitro and shown to interact with NFL 3' UTR mRNA. Mutation of one or both motifs resulted in decreased 14-3-3 interaction, changes in predicted mRNA structure or alteration in stability of the mRNA. These data show a novel interaction for 14-3-3 with NFL mRNA, and suggests that 14-3-3 may play a role in regulating NFL mRNA stability.

  18. Development of a membrane-less dynamic field gradient focusing device for the separation of low-molecular-weight molecules.

    PubMed

    Burke, Jeffrey M; Smith, Colin D; Ivory, Cornelius F

    2010-03-01

    Dynamic field gradient focusing uses an electric field gradient generated by controlling the voltage profile of an electrode array to separate and concentrate charged analytes according to their individual electrophoretic mobilities. This study describes a new instrument in which the electrodes have been placed within the separation channel. The major challenge faced with this device is that when applied voltages to the electrodes are larger than the redox potential of water, electrolysis will occur, producing hydrogen ions (H+) plus oxygen gas on the anodes and hydroxide (OH(-)) plus hydrogen gas on the cathodes. The resulting gas bubbles and pH excursions can cause problems with system performance and reproducibility. An on-column, degassing system that can remove gas bubbles "on-the-fly" is described. In addition, the use of a high capacity, low-conductivity buffer to address the problem of the pH shift that occurs due to the production of H+ on the anodes is illustrated. Finally, the successful separation of three, low-molecular-weight dyes (amaranth, bromophenol blue and methyl red) is described.

  19. In silico design of low molecular weight protein-protein interaction inhibitors: Overall concept and recent advances.

    PubMed

    Kuenemann, Mélaine A; Sperandio, Olivier; Labbé, Céline M; Lagorce, David; Miteva, Maria A; Villoutreix, Bruno O

    2015-10-01

    Protein-protein interactions (PPIs) are carrying out diverse functions in living systems and are playing a major role in the health and disease states. Low molecular weight (LMW) "drug-like" inhibitors of PPIs would be very valuable not only to enhance our understanding over physiological processes but also for drug discovery endeavors. However, PPIs were deemed intractable by LMW chemicals during many years. But today, with the new experimental and in silico technologies that have been developed, about 50 PPIs have already been inhibited by LMW molecules. Here, we first focus on general concepts about protein-protein interactions, present a consensual view about ligandable pockets at the protein interfaces and the possibilities of using fast and cost effective structure-based virtual screening methods to identify PPI hits. We then discuss the design of compound collections dedicated to PPIs. Recent financial analyses of the field suggest that LMW PPI modulators could be gaining momentum over biologics in the coming years supporting further research in this area.

  20. Effect of low molecular weight epidermal material upon DNA synthesis in primary cultures of newborn rat keratinocytes

    SciTech Connect

    Abler, A.S.

    1985-01-01

    The objective of this study was to isolate inhibitors of replicative DNA synthesis from newborn rat epidermis. The strategy for this study was to assay epidermal extracts for inhibitors of DNA synthesis in primary cultures of newborn rat keratinocytes. DNA synthesis was measured as the incorporation of /sup 4/H-TdR into acid precipitable material. The low molecular weight fraction, LMWF (less than 10Kd), of an aqueous epidermal extract was found to contain activity that inhibits replicative DNA synthesis in primary cultures. The inhibitory activity of the LMWD was detected in a novel assay utilizing primary cultures that were synchronized at the G1/S boundary with the DNA polymerase alpha inhibitor, aphidicolin. LMWF caused a dose dependent inhibition of replicative DNA synthesis as measured by the incorporation of /sup 3/H-TdR into acid precipitable material. The magnitude of the inhibitory effect for a given dose of LMWF was dependent upon the duration of exposure to that dose. The results presented in this investigation suggest that newborn rat epidermis contains a small polypeptide factor that inhibits replicative DNA synthesis in primary culture of newborn rat keratinocytes.

  1. Comparison of three different enrichment strategies for serum low molecular weight protein identification using shotgun proteomics approach.

    PubMed

    Capriotti, Anna Laura; Caruso, Giuseppe; Cavaliere, Chiara; Piovesana, Susy; Samperi, Roberto; Laganà, Aldo

    2012-08-31

    Serum low-molecular weight (LMW) proteins potentially contain useful biological information and their identification can be used to discover novel potential biomarkers. Given the high complexity of serum samples, in the last years several different prefractionation and enrichment strategies have been developed. In this study three different methods, i.e. hydrogel nanoparticles, Proteominer(®) peptide ligand affinity beads and Sartorius Vivaspin(®) centrifugal ultrafiltration device, were compared and evaluated in order to select the best strategy for the enrichment and prefractionation of LMW proteins. A shotgun proteomics approach was adopted, with in-solution proteolytic digestion of the whole protein mixture and determination of the resulting peptides by nanoHPLC coupled with a high-resolution Orbitrap LTQ-XL mass spectrometer. Data analysis, focusing on the LMW proteome (MW ≤ 40 kDa), has shown that the hydrogel nanoparticles performed better in enriching the LMW protein profiles, with 115 proteins identified against 93 and 95 for Proteominer(®) beads and Sartorius Vivaspin(®) device, respectively.

  2. The role of low molecular weight organic acids on controlling pH in coastal sea water

    NASA Astrophysics Data System (ADS)

    Ding, H.

    2015-12-01

    Series investigation of the Jiaozhou Bay, China, observed existences of three low molecular weight organic acids (LMWOAs), including lactic acid, acetic acid and formic acid, with high concentration in the sea water. Generally, their amount accounted for about 20% of DOC in the sea water of the bay. Human activities around the bay were considered as the major source of the LMWOAs. Also, long term detection showed that the pH value in the Jiaozhou Bay was lower than that in the adjacent Yellow Sea. On average, the difference of pH values between the bay and the Yellow was about 0.2. Due to higher concentrations of the LMWOAs, their contribution to lower pH value of the bay should not be ignored. To validate the effect of LMWOAs on the pH value of the bay, a new software was developed to calculate the pH value in the sea water samples based on alkalinity by adding three items of the three organic acids in the expression. Compared to the traditional pH calculating software, the new software could improve the calculating results significantly. Our results confirmed that LMWOAs was an important control factor to adjust pH values in coastal area.

  3. Influence of arsenic stress on synthesis and localization of low-molecular-weight thiols in Pteris vittata.

    PubMed

    Sakai, Yuki; Watanabe, Toshihiro; Wasaki, Jun; Senoura, Takeshi; Shinano, Takuro; Osaki, Mitsuru

    2010-12-01

    The roles of low-molecular-weight thiols (LMWTs), such as glutathione and phytochelatins, in arsenic (As) tolerance and hyperaccumulation in Pteris vittata an As-hyperaccumulator fern remain to be better understood. This study aimed to thoroughly characterize LMWT synthesis in P. vittata to understand the roles played by LMWTs in As tolerance and hyperaccumulation. LMWT synthesis in P. vittata was induced directly by As, and not by As-mediated oxidative stress. Expression of PvECS2, one of the putative genes of γ-glutamylcysteine synthetase (γECS), increases in P. vittata shoots at 48h after the onset of As exposure, almost corresponding to the increase in the concentrations of γ-glutamylcysteine and glutathione. Furthermore, localization of As showed similar trends to those of LMWTs in fronds at both whole-frond and cellular levels. This study thus indicates the specific contribution of LMWTs to As tolerance in P. vittata. γECS may be responsible for the As-induced enhancement of LMWT synthesis.

  4. Effect of toasting on non-volatile and volatile vine-shoots low molecular weight phenolic compounds.

    PubMed

    Sánchez-Gómez, R; Zalacain, A; Alonso, G L; Salinas, M R

    2016-08-01

    Low molecular weight phenolic compounds (LMWPC), including non-volatile and volatile, of Airén and Moscatel vine-shoot cultivars waste submitted to different toasting conditions (light, 180°/15min; medium, 180°/30min; high 180°/45min) were studied in order to exploit them with oenological purposes. The LMWPC differences were mainly due to the toasting times rather than vine-shoot variety. In non-volatile LMWPC fraction, flavanols and almost all phenolic acids decreased by toasting. The presence of trans-resveratrol has a special relevance at light toasting: 14 times more concentrated in Airén and 6 times in Moscatel vine-shoots, than their respective non-toasted samples. The volatile LMWPC showed a significant increment with toasting, being vanillin the one with the highest difference respect to non-toasted samples at high conditions: more than 15 times in Airén and 11 in Moscatel. Although toasting reduced some LMWPC, particular characteristics of these vine-shoots must be taken into account when considering its future use. PMID:26988529

  5. 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

  6. Presence of a low molecular weight endogenous inhibitor on 3H-muscimol binding in synaptic membranes

    NASA Astrophysics Data System (ADS)

    Yoneda, Yukio; Kuriyama, Kinya

    1980-06-01

    The specific binding of 3H-muscimol to synaptic membrane preparations obtained from the rat brain has been thought to reflect the association of γ-aminobutyric acid (GABA), a potential candidate as an inhibitory neurotransmitter in the mammalian central nervous system (CNS), with its synaptic receptors1,2. Treatment of synaptic membranes with Triton X-100 significantly increases the specific binding of 3H-muscimol2. Several reports also indicate the presence of endogenous substances, such as GABA3, acidic protein4 and phosphatidylethanolamine5, which inhibit Na-independent binding of 3H-GABA in the synaptic membranous fractions from the rat brain. We report here that in the supernatant obtained from Triton-treated synaptic membranes there exists a new type of endogenous inhibitor of 3H-muscimol binding which is apparently different from the inhibitory substances described previously3-5. The new inhibitor has a low molecular weight (MW) and probably originated from neurones rather than glial cells. We have termed this endogenous inhibitor the GABA receptor binding inhibitory factor (GRIF).

  7. Development of a membrane-less dynamic field gradient focusing device for the separation of low-molecular-weight molecules

    PubMed Central

    Burke, Jeffrey M.; Smith, Colin D.; Ivory, Cornelius F.

    2010-01-01

    Dynamic field gradient focusing uses an electric field gradient generated by controlling the voltage profile of an electrode array to separate and concentrate charged analytes according to their individual electrophoretic mobilities. This study describes a new instrument in which the electrodes have been placed within the separation channel. The major challenge faced with this device is that when applied voltages to the electrodes are larger than the redox potential of water, electrolysis will occur, producing hydrogen ions (H+) plus oxygen gas on the anodes and hydroxide (OH−) plus hydrogen gas on the cathodes. The resulting gas bubbles and pH excursions can cause problems with system performance and reproducibility. An on-column, degassing system that can remove gas bubbles “on-the-fly” is described. In addition, the use of a high capacity, low-conductivity buffer to address the problem of the pH shift that occurs due to the production of H+ on the anodes is illustrated. Finally, the successful separation of three, low-molecular-weight dyes (amaranth, bromophenol blue and methyl red) is described. PMID:20191553

  8. Stability of Chloropyromorphite in Ryegrass Rhizosphere as Affected by Root-Secreted Low Molecular Weight Organic Acids

    PubMed Central

    Wei, Wei; Wang, Yu; Wang, Zheng; Han, Ruiming; Li, Shiyin; Wei, Zhenggui; Zhang, Yong

    2016-01-01

    Understanding the stability of chloropyromorphite (CPY) is of considerable benefit for improving risk assessment and remediation strategies in contaminated water and soil. The stability of CPY in the rhizosphere of phosphorus-deficient ryegrass was evaluated to elucidate the role of root-secreted low molecular weight organic acids (LMWOAs) on the dissolution of CPY. Results showed that CPY treatments significantly reduced the ryegrass biomass and rhizosphere pH. The presence of calcium nitrate extractable lead (Pb) and phosphorus (P) suggested that CPY in the rhizosphere could be bioavailable, because P and Pb uptake by ryegrass potentially provided a significant concentration gradient that would promote CPY dissolution. Pb accumulation and translocation in ryegrass was found to be significantly higher in P-sufficient conditions than in P-deficient conditions. CPY treatments significantly enhanced root exudation of LMWOAs irrigated with P-nutrient solution or P-free nutrient solution. Oxalic acid was the dominant species in root-secreted LMWOAs of ryegrass under P-free nutrient solution treatments, suggesting that root-secreted oxalic acid may be the driving force of root-induced dissolution of CPY. Hence, our work, provides clarifying hints on the role of LMWOAs in controlling the stability of CPY in the rhizosphere. PMID:27494023

  9. Occurrence of non-protein low molecular weight cardiotoxin in Indian King Cobra (Ophiophagus hannah) Cantor 1836, venom.

    PubMed

    Saha, Archita; Gomes, Aparna; Giri, B; Chakravarty, A K; Biswas, A K; Dasgupta, S C; Gomes, A

    2006-04-01

    Pathophysiology due to snakebite is a combined effect of various actions of the complex venom constituents. Importance of protein toxins in snake envenomation is well known. The present investigation reports the existence of nonprotein/nonpetide low molecular weight toxin in Indian King Cobra venom, which plays an important role in envenomation consequences in experimental animal models. A group of non-peptidic toxins (OH-NPT1) was isolated from Indian King Cobra Ophiophagus hannah by thin layer chromatography and silica gel column chromatography. UV, IR, NMR and (ESI) TOF-MS studies characterized the OH-NPT1 as a mixture of aliphatic acids having molecular weights 256, 326 and 340Da. The minimum lethal dose of OH-NPT1 was found to be 2.5 microg/20g (iv) and 4microg/20g (ip) in male albino mice. The cardiotoxic property of OH-NPT1 was established through studies on isolated guinea pig heart and auricle preparations, ECG studies in albino rat and estimation of LDH1/LDH and CPK-MB/CPK ratio in Swiss albino mice. Commercial antiserum failed to neutralize the lethality and cardiotoxicity of the toxin. However, calcium and magnesium effectively neutralized the lethal action. PMID:16629369

  10. Occurrence of non-protein low molecular weight cardiotoxin in Indian King Cobra (Ophiophagus hannah) Cantor 1836, venom.

    PubMed

    Saha, Archita; Gomes, Aparna; Giri, B; Chakravarty, A K; Biswas, A K; Dasgupta, S C; Gomes, A

    2006-04-01

    Pathophysiology due to snakebite is a combined effect of various actions of the complex venom constituents. Importance of protein toxins in snake envenomation is well known. The present investigation reports the existence of nonprotein/nonpetide low molecular weight toxin in Indian King Cobra venom, which plays an important role in envenomation consequences in experimental animal models. A group of non-peptidic toxins (OH-NPT1) was isolated from Indian King Cobra Ophiophagus hannah by thin layer chromatography and silica gel column chromatography. UV, IR, NMR and (ESI) TOF-MS studies characterized the OH-NPT1 as a mixture of aliphatic acids having molecular weights 256, 326 and 340Da. The minimum lethal dose of OH-NPT1 was found to be 2.5 microg/20g (iv) and 4microg/20g (ip) in male albino mice. The cardiotoxic property of OH-NPT1 was established through studies on isolated guinea pig heart and auricle preparations, ECG studies in albino rat and estimation of LDH1/LDH and CPK-MB/CPK ratio in Swiss albino mice. Commercial antiserum failed to neutralize the lethality and cardiotoxicity of the toxin. However, calcium and magnesium effectively neutralized the lethal action.

  11. Influence of low molecular weight fractions of humic substances on reducing capacities and distribution of redox functional groups

    NASA Astrophysics Data System (ADS)

    Yang, Zhen; Jiang, Jie

    2016-04-01

    Humic substances (HS) are redox-active organic compounds and their reducing capacities depend on their molecule structure and distribution of redox functional groups (RFG). During dialysis experiments, bulk humic acids (HA) were separated into low molecular weight fractions (LMWF) and retentate. LMWF account for only 2% of the total organic carbon content of HA molecules, however, their reducing capacities are up to 33 times greater than either those of the bulk HA or retentate. Furthermore, the total reducing capacity of the bulk HA accounts for less than 15% of the total reducing capacity of bulk HA, retentate and LMWF combined, suggesting that releasing of LMWF cannot reduce the number of RFG. RFG are neither in fixed amounts nor in uniformly distributed in bulk HA. LWMF have great fluorescence intensities for humic-like fluorophores (quinone-like functional groups), where quinonoid π-π* transition is responsible for the great reducing capacities of LMWF, and protein-like fluorophores. The 3,500 Da molecules (1.25 nm diameter) of HS could stimulate transformation of redox-active metals or potential pollutants trapped in soil micropores (< 2 nm diameter). A development of relationship between reducing capacity and Ex/Em position provides a possibility to predicate relative reducing capacities of HS in environmental samples.

  12. Phenylboronic Acid Appended Pyrene-Based Low-Molecular-Weight Injectable Hydrogel: Glucose-Stimulated Insulin Release.

    PubMed

    Mandal, Deep; Mandal, Subhra Kanti; Ghosh, Moumita; Das, Prasanta Kumar

    2015-08-17

    A pyrene-containing phenylboronic acid (PBA) functionalized low-molecular-weight hydrogelator was synthesized with the aim to develop glucose-sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8-12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL(-1) . The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π-π stacking, and van der Waals interactions are the key factors for the self-assembled gelation. The diol-sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose-responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose-induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin-loaded hydrogel showed thixotropic self-recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells.

  13. Protective effects of low molecular weight chondroitin sulfate on amyloid beta (Aβ)-induced damage in vitro and in vivo.

    PubMed

    Zhang, Q; Li, J; Liu, C; Song, C; Li, P; Yin, F; Xiao, Y; Li, J; Jiang, W; Zong, A; Zhang, X; Wang, F

    2015-10-01

    In the present study, we investigated the effects of low molecular weight chondroitin sulfate (LMWCS) on amyloid beta (Aβ)-induced neurotoxicity in vitro and in vivo. The in vitro results showed that LMWCS blocked Aβ25-35-induced cell viability loss and apoptosis, decreased intracellular calcium concentration, reactive oxygen species (ROS) levels, the mitochondrial membrane potential (MMP) depolarization, and the protein expression of Caspase-3. During in vivo experiments, LMWCS improved the cognitive impairment induced by Aβ1-40, increased the level of choline acetyltransferase (ChAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and decreased the level of malondialdehyde (MDA) and acetylcholinesterase (AChE) in the mouse brain. Moreover, LMWCS decreased the density of pyramidal cells of CA1 regions, and suppressed the protein expression of Bax/Bcl-2 and Caspase-3, -9 in the hippocampus of mice. In conclusion, LMWCS possessed neuroprotective properties against toxic effects induced by Aβ peptides both in vitro and in vivo, which might be related to anti-apoptotic activity. LMWCS might be a useful preventive and therapeutic compound for Alzheimer's disease.

  14. Enhanced miscibility of low-molecular-weight polystyrene/polyisoprene blends in supercritical CO{sub 2}

    SciTech Connect

    Walker, T.A.; Raghavan, S.R.; Royer, J.R.; Khan, S.A.; Spontak, R.J.; Smith, S.D.; Wignall, G.D.; Melnichenko, Y.

    1999-07-01

    While ongoing efforts continue to explore the high-pressure phase equilibria of polymer blends, few studies have attempted to address the impact of a supercritical (sc) fluid on such equilibria. In this work, the authors report on the phase behavior of an upper critical solution temperature (UCST) polymer blend in the presence of supercritical carbon dioxide (scCO{sub 2}), a nonselective plasticizing agent. Blends composed of low-molecular-weight polystyrene and polyisoprene have been examined as a function of temperature in scCO{sub 2} by visual inspection, small-angle neutron scattering, and spectrophotometry. In the presence of scCO{sub 2}, the cloud point temperature is depressed by as much as 28 C, depending on both blend composition and CO{sub 2} pressure. Complementary studies performed with nitrogen decouple the plasticization efficacy of CO{sub 2} from free-volume compression due to hydrostatic pressure. Existence of a pressure yielding a maximum in CO{sub 2}-induced cloud point depression is established. These results provide evidence for enhanced polymer miscibility as a result of the plasticizing effectiveness and tunable solubility of scCO{sub 2}.

  15. Chitosan nanoconstructs for improved oral delivery of low molecular weight heparin: In vitro and in vivo evaluation.

    PubMed

    Paliwal, Rishi; Paliwal, Shivani R; Agrawal, Govind P; Vyas, Suresh P

    2012-01-17

    The aim of present study was to investigate the potential of mucoadhesive polymer chitosan (CS) and N-trimethyl chitosan (TMC) based nanoparticulate systems for oral bioavailability enhancement of low molecular weight heparin (LMWH). The TMC was synthesized by methylation of chitosan followed by characterization using infrared spectroscopy and (1)H-NMR spectroscopy. The IR and NMR spectra of TMC confirmed the presence of trimethyl groups and estimated the degree of quaternization for TMC about 46%. TMC nanoparticles were then prepared by ionic gelation method. The developed CS-NPs and TMC-NPs were characterized for various parameters including morphology, particle size, zeta potential, entrapment efficiency, in vitro release behavior and storage stability at different temperature and simulated gastrointestinal tract conditions. The fluorescent microscopy study confirmed the higher particle uptake of TMC-NPs by gastrointestinal epithelium in comparison to the CS-NPs. The concentration of LMWH in the systemic circulation followed by oral administration of formulations was estimated using FXa chromogenic assay. A significant increase (p<0.05) in the oral bioavailability of LMWH was observed with TMC-NPs than both CS-NPs as well as plain LMWH solution. These findings suggested that TMC nanoparicles hold promise for oral delivery of LMWH and clinical applicability for the treatment of vascular disorders like deep vein thrombosis and pulmonary embolism, etc. PMID:22079712

  16. Design and physicochemical characterisation of novel dissolving polymeric microneedle arrays for transdermal delivery of high dose, low molecular weight drugs

    PubMed Central

    McCrudden, Maelíosa T.C.; Alkilani, Ahlam Zaid; McCrudden, Cian M.; McAlister, Emma; McCarthy, Helen O.; Woolfson, A. David; Donnelly, Ryan F.

    2014-01-01

    We describe formulation and evaluation of novel dissolving polymeric microneedle (MN) arrays for the facilitated delivery of low molecular weight, high dose drugs. Ibuprofen sodium was used as the model here and was successfully formulated at approximately 50% w/w in the dry state using the copolymer poly(methylvinylether/maleic acid). These MNs were robust and effectively penetrated skin in vitro, dissolving rapidly to deliver the incorporated drug. The delivery of 1.5 mg ibuprofen sodium, the theoretical mass of ibuprofen sodium contained within the dry MN alone, was vastly exceeded, indicating extensive delivery of the drug loaded into the baseplates. Indeed in in vitro transdermal delivery studies, approximately 33 mg (90%) of the drug initially loaded into the arrays was delivered over 24 h. Iontophoresis produced no meaningful increase in delivery. Biocompatibility studies and in vivo rat skin tolerance experiments raised no concerns. The blood plasma ibuprofen sodium concentrations achieved in rats (263 μg ml− 1 at the 24 h time point) were approximately 20 times greater than the human therapeutic plasma level. By simplistic extrapolation of average weights from rats to humans, a MN patch design of no greater than 10 cm2 could cautiously be estimated to deliver therapeutically-relevant concentrations of ibuprofen sodium in humans. This work, therefore, represents a significant progression in exploitation of MN for successful transdermal delivery of a much wider range of drugs. PMID:24556420

  17. Transdermal delivery of low molecular weight heparin loaded in flexible liposomes with bioavailability enhancement: comparison with ethosomes.

    PubMed

    Song, Yun-Kyoung; Hyun, Seo Yeon; Kim, Hyung-Tae; Kim, Chong-Kook; Oh, Jung-Mi

    2011-01-01

    Low molecular weight heparin (LMWH)-loaded flexible liposomes (flexosomes) were formulated for transdermal delivery, and their physicochemical and pharmacokinetic parameters were compared with LMWH-loaded ethosomes. Flexosomes had similar particle size compared with ethosomes, but their deformability was higher than that of ethosomes (76.7% vs. 46.8%). In vitro, flexosomes demonstrated 2.6-fold higher permeability coefficient than ethosomes. In comparison to LMWH aqueous solution, skin deposition of flexosome increased 3.2-fold, while that of ethosome increased only 2.0-fold. In vivo, after the topical application of flexosome to hairless mouse, [anti-Xa](max) was 1.11 IU/mL, while ethosomes showed only 0.32 IU/mL. Moreover, AUC(0-24 h) of flexosomes was 2.5-fold higher than ethosomes. In conclusion, the enhanced skin permeation and bioavailability of LMWH can be achieved with flexosomes in comparison with ethosomes. The LMWH transdermal delivery via flexosomes has the potential to replace the parenteral dosage forms for the treatment of venous thromboembolism, pulmonary embolism and cardiovascular events.

  18. Lake secondary production fueled by rapid transfer of low molecular weight organic carbon from terrestrial sources to aquatic consumers.

    PubMed

    Berggren, M; Ström, L; Laudon, H; Karlsson, J; Jonsson, A; Giesler, R; Bergström, A-K; Jansson, M

    2010-07-01

    Carbon of terrestrial origin often makes up a significant share of consumer biomass in unproductive lake ecosystems. However, the mechanisms for terrestrial support of lake secondary production are largely unclear. By using a modelling approach, we show that terrestrial export of dissolved labile low molecular weight carbon (LMWC) compounds supported 80% (34-95%), 54% (19-90%) and 23% (7-45%) of the secondary production by bacteria, protozoa and metazoa, respectively, in a 7-km(2) boreal lake (conservative to liberal estimates in brackets). Bacterial growth on LMWC was of similar magnitude as that of primary production (PP), and grazing on bacteria effectively channelled the LMWC carbon to higher trophic levels. We suggest that rapid turnover of forest LMWC pools enables continuous export of fresh photosynthates and other labile metabolites to aquatic systems, and that substantial transfer of LMWC from terrestrial sources to lake consumers can occur within a few days. Sequestration of LMWC of terrestrial origin, thus, helps explain high shares of terrestrial carbon in lake organisms and implies that lake food webs can be closely dependent on recent terrestrial PP.

  19. A Delicate Balance When Substituting a Small Hydrophobe onto Low Molecular Weight Polyethylenimine to Improve Its Nucleic Acid Delivery Efficiency.

    PubMed

    Meneksedag-Erol, Deniz; KC, Remant Bahadur; Tang, Tian; Uludağ, Hasan

    2015-11-11

    High molecular weight (HMW) polyethylenimine (PEI) is one of the most versatile nonviral gene vectors that was extensively investigated over the past two decades. The cytotoxic profile of HMW PEI, however, encouraged a search for safer alternatives. Because of lack of cytotoxicity of low molecular weight (LMW) PEI, enhancing its performance via hydrophobic modifications has been pursued to this end. Since the performance of modified PEIs depends on the nature and extent of substituents, we systematically investigated the effect of hydrophobic modification of LMW (1.2 kDa) PEI with a short propionic acid (PrA). Moderate enhancements in PEI hydrophobicity resulted in enhanced cellular uptake of polyplexes and siRNA-induced silencing efficacy, whereas further increase in PrA substitution abolished the uptake as well as the silencing. We performed all-atom molecular dynamics simulations to elucidate the mechanistic details behind these observations. A new assembly mechanism was observed by the presence of hydrophobic PrA moieties, where PrA migrated to core of the polyplex. This phenomenon caused higher surface hydrophobicity and surface charge density at low substitutions, and it caused deleterious effects on surface hydrophobicity and cationic charge at higher substitutions. It is evident that an optimal balance of hydrophobicity/hydrophilicity is needed to achieve the desired polyplex properties for an efficient siRNA delivery, and our mechanistic findings should provide valuable insights for the design of improved substituents on nonviral carriers.

  20. The effect of conjugation to gold nanoparticles on the ability of low molecular weight chitosan to transfer DNA vaccine.

    PubMed

    Zhou, Xianfeng; Zhang, Xizhen; Yu, Xianghui; Zha, Xiao; Fu, Qiuan; Liu, Bin; Wang, Xueyun; Chen, Yan; Chen, Yue; Shan, Yaming; Jin, Yinghua; Wu, Yongge; Liu, Junqiu; Kong, Wei; Shen, Jiacong

    2008-01-01

    Nonviral gene delivery systems based on conventional high molecular weight chitosans are efficient as DNA vaccine delivery system, but have poor physical properties such as aggregated shapes, low solubility at neutral pH, high viscosity at concentrations used for in vivo delivery and a slow onset of action. Furthermore, Chitosan oligomers shorter than 14 monomers units were recently found to form only weak complexes with DNA, resulting in physically unstable polyplexes in vitro and in vivo. Here, low molecular weight chitosans with an average molecular mass of 6kDa (Chito6) have been covalently attached to gold nanoparticles (GNPs), and the potency of the resulting Chito6-GNPs conjugates as vectors for the delivery of plasmid DNA has been investigated in vitro and in vivo. After delivery by intramuscular immunization in BALB/c mice, the Chito6-GNPs conjugates induced an enhanced serum antibody response 10 times more potent than naked DNA vaccine. Additionally, in contrast to naked DNA, the Chito6-GNPs conjugates induced potent cytotoxic T lymphocyte responses at a low dose.

  1. Characterization of low molecular weight fragments from gamma irradiated κ-carrageenan used as plant growth promoter

    NASA Astrophysics Data System (ADS)

    Abad, Lucille V.; Aurigue, Fernando B.; Relleve, Lorna S.; Montefalcon, Djowel Recto V.; Lopez, Girlie Eunice P.

    2016-01-01

    Radiation degraded κ-carrageenan (1% solution at absorbed doses of 20 kGy and 30 kGy) were tested for its plant growth promoter (PGP) effect on pechay plants under hydroponics condition. Results revealed that higher PGP effects were found in κ-carrageenan irradiated at an absorbed dose of 30 kGy. Mw of irradiated κ-carrageenan as measured by GPC were determined to be 7362 Da and 6762 Da for 20 kGy and 30 kGy, respectively. Fractionation of the irradiated κ-carrageenan (30 kGy) was done to separate different Mw fractions using Mw cut-off filters of 1 kDa, 3 kDa, and 5 kDa. The PGP effect of the different retentates showed that biological activity in plants followed the order of 5 kDa>3 kDa>1 kDa using hydroponics condition but the reverse was observed in the order of 1 kDa>3 kDa>5 kDa when absorbed in plants by foliar spraying. GPC chromatogram indicated at least three (3) low molecular weight (LMW) fragments from radiation modified κ-carrageenan solution with an Mw<2000 Da. A fragment has also been identified with an Mw of as low as 160 Da which was produced under acidic (un-neutralized) condition. This may be attributed to the formation of 5-hydroxymethylfurfural (5-HMF).

  2. Purification and characteristics of a low-molecular-weight peptide possessing oxidative capacity for phenol from Phanerochaete chrysosporium.

    PubMed

    Hu, Ming; Zhang, Weican; Lu, Xuemei; Gao, Peiji

    2006-06-01

    A new low-molecular-weight peptide with phenol oxidase activity, named Pc factor, was isolated and purified from liquid culture of a white-rot basidiomycete Phanerochaete chrysosporium. Its molecular weight was about 600 Da estimated by gel-filtration. Three amino acids Glu, Gly and Val were detected in hydrolysate. Absorption peaks corresponding to amino acids and peptide were observed by UV and IR spectra analysis. And the signal of Ca of amino acid was also detected by 13C-NMR method. Pc factor had high thermostability and remained active in weakly alkalescent pH range. It could chelate Fe3+ and reduce it to Fe2+, but no hydroxyl radical HO* could be detected during the reaction process. It could oxidize phenolic lignin-model compounds such as 2,6-dimethoxyphenol (2,6-DMP), 2,2'-azinobis (3-ethylbenzathiazoline-6-sulfinic acid) (ABTS) and syringaldazine in the absence of Mn2+ and H2O2. These characteristics differed greatly from those of manganese peroxidases. The oxidative catalysis of Pc factor can be enhanced by certain metal ions such as Cu2+ and Mn2+ etc., and O2 molecule was necessary for this reaction. In summary, Pc factor may function as an electron carrier in this novel oxidation-reduction system. PMID:16856493

  3. A dual labelling method for measuring uptake of low molecular weight compounds into the pathogenic yeast Candida albicans.

    PubMed

    Ziegelbauer, K

    1998-10-01

    In contrast to other eukaryotic cells the pathogenic yeast Candida albicans is resistant to many structurally unrelated metabolic inhibitors. Reduced permeability due to the cell wall and/or altered plasma membrane composition is thought to be at least partly responsible for this phenomenon. To study the uptake of low molecular weight compounds into C. albicans we developed a dual labelling method. Intact cells, metabolically inactivated cells, spheroplasts or membrane fragments of C. albicans were incubated with various [14C]-labelled compound in the presence of [3H]-labelled water. After separation of cells and supernatant isotope ratios [3H]/[14C] were determined. Quotients of the isotope ratios from cells and supernatant, called enrichment coefficients, were calculated under all four conditions. The enrichment coefficients indicated whether a compound can enter C. albicans cells, is trapped within the cell wall, is enriched in the lipophilic membrane compartment, is actively accumulated or actively exported by multidrug resistance carriers. We used six structurally unrelated compounds to test our method. We found no evidence for a general impermeability of C. albicans.

  4. Purification and partial characterization of low molecular weight vicilin-like glycoprotein from the seeds of Citrullus lanatus.

    PubMed

    Yadav, Sushila; Tomar, Anil Kumar; Jithesh, O; Khan, Meraj Alam; Yadav, R N; Srinivasan, A; Singh, Tej P; Yadav, Savita

    2011-12-01

    The watermelon (Citrullus lanatus) seeds are highly nutritive and contain large amount of proteins and many beneficial minerals such as magnesium, calcium, potassium, iron, phosphorous, zinc etc. In various parts of the world, C. lanatus seed extracts are used to cure cancer, cardiovascular diseases, hypertension, and blood pressure. C. lanatus seed extracts are also used as home remedy for edema and urinary tract problems. In this study, we isolated protein fraction of C. lanatus seeds using various protein separation methods. We successfully purified a low molecular weight vicilin-like glycoprotein using chromatographic methods followed by SDS-PAGE and MALDI-TOF/MS identification. This is the first report of purification of a vicilin like polypeptide from C. lanatus seeds. In next step, we extracted mRNA from immature seeds and reverse transcribed it using suitable forward and reverse primers for purified glycoprotein. The PCR product was analysed on 1% agarose gel and was subsequently sequenced by Dideoxy DNA sequencing method. An amino acid translation of the gene is in agreement with amino acid sequences of the identified peptides.

  5. Stability of Chloropyromorphite in Ryegrass Rhizosphere as Affected by Root-Secreted Low Molecular Weight Organic Acids.

    PubMed

    Wei, Wei; Wang, Yu; Wang, Zheng; Han, Ruiming; Li, Shiyin; Wei, Zhenggui; Zhang, Yong

    2016-01-01

    Understanding the stability of chloropyromorphite (CPY) is of considerable benefit for improving risk assessment and remediation strategies in contaminated water and soil. The stability of CPY in the rhizosphere of phosphorus-deficient ryegrass was evaluated to elucidate the role of root-secreted low molecular weight organic acids (LMWOAs) on the dissolution of CPY. Results showed that CPY treatments significantly reduced the ryegrass biomass and rhizosphere pH. The presence of calcium nitrate extractable lead (Pb) and phosphorus (P) suggested that CPY in the rhizosphere could be bioavailable, because P and Pb uptake by ryegrass potentially provided a significant concentration gradient that would promote CPY dissolution. Pb accumulation and translocation in ryegrass was found to be significantly higher in P-sufficient conditions than in P-deficient conditions. CPY treatments significantly enhanced root exudation of LMWOAs irrigated with P-nutrient solution or P-free nutrient solution. Oxalic acid was the dominant species in root-secreted LMWOAs of ryegrass under P-free nutrient solution treatments, suggesting that root-secreted oxalic acid may be the driving force of root-induced dissolution of CPY. Hence, our work, provides clarifying hints on the role of LMWOAs in controlling the stability of CPY in the rhizosphere. PMID:27494023

  6. Inhibition of Helicobacter pylori adhesion to Kato III cells by intact and low molecular weight acharan sulfate.

    PubMed

    Sim, Joon-Soo; Hahn, Bum-Soo; Im, A-Rang; Park, Youmie; Shin, Ji-Eun; Bae, Eun-Ah; Kim, Dong-Hyun; Kim, Yeong Shik

    2011-08-01

    We investigated the inhibitory activity of glycosaminoglycans (GAGs) in terms of growth, adhesion, and VacA vacuolation of Helicobacter pylori. Intact acharan sulfate (AS, MW:114 kDa) potently inhibited H. pylori adhesion to Kato III cells with IC(50) value of 1.4 mg/mL, while other GAGs did not show any inhibitory activity except for heparin which is a well-known inhibitor of H. pylori adhesion. To investigate whether low molecular weight acharan sulfate (LMWAS) can inhibit H. pylori adhesion, we performed chemical depolymerization of AS by radical reactions to obtain LMWAS. Its physicochemical properties were characterized by high-performance size exclusion chromatography (HPSEC), agarose gel electrophoresis, disaccharide compositional analysis after digestion with heparinase II, and (1)H-NMR spectroscopy. The most potent molecular size of LMWAS was 3 kDa with IC(50) value of 32 μg/mL, which is 44-fold more potent than intact AS. These results suggest that AS as well as other GAGs can be chemically depolymerized by free radicals and LMWAS compared to intact AS can be applied as a pharmaceutical candidate in order to inhibit H. pylori adhesion to Kato III cells. PMID:21744069

  7. Development of a fluorescent anti-factor Xa assay to monitor unfractionated and low molecular weight heparins.

    PubMed

    Harris, Leanne F; Castro-López, Vanessa; Hammadi, Nissrin; O'Donnell, James S; Killard, Anthony J

    2010-06-15

    Fluorogenic assays have many potential advantages over traditional clot-based and chromogenic assays such as the absence of interference from a range of factor deficiencies as well as offering the possibility of assays in platelet rich plasma or whole blood. A fluorogenic anti-factor Xa (anti-FXa) assay has been developed for the determination of unfractionated heparin (UFH), low molecular weight heparins (LMWHs), namely enoxaparin and tinzaparin, and the synthetic heparinoid danaparoid, in commercial human pooled plasma. The assay was based on the complexation of heparin-spiked plasmas with exogenous FXa at a concentration of 4nM in the presence of 0.9microM of the fluorogenic substrate methylsulfonyl-D-cyclohexylalanyl-glycyl-arginine-7-amino-4-methylcoumarin acetate (Pefafluor FXa). Pooled plasma samples were spiked with concentrations of anticoagulants in the range 0-1.6U/ml. The assay was capable of the measurement of UFH and danaparoid in the range 0-1U/ml, and enoxaparin and tinzaparin in the range 0-0.8 and 0-0.6U/ml, respectively. Correlation coefficients generated by linear regression of the log/lin data analysis were between 0.93 and 0.96 for the anticoagulants tested. Assay percentage coefficients of variation were typically below 7%. PMID:20441964

  8. Chitosan nanoconstructs for improved oral delivery of low molecular weight heparin: In vitro and in vivo evaluation.

    PubMed

    Paliwal, Rishi; Paliwal, Shivani R; Agrawal, Govind P; Vyas, Suresh P

    2012-01-17

    The aim of present study was to investigate the potential of mucoadhesive polymer chitosan (CS) and N-trimethyl chitosan (TMC) based nanoparticulate systems for oral bioavailability enhancement of low molecular weight heparin (LMWH). The TMC was synthesized by methylation of chitosan followed by characterization using infrared spectroscopy and (1)H-NMR spectroscopy. The IR and NMR spectra of TMC confirmed the presence of trimethyl groups and estimated the degree of quaternization for TMC about 46%. TMC nanoparticles were then prepared by ionic gelation method. The developed CS-NPs and TMC-NPs were characterized for various parameters including morphology, particle size, zeta potential, entrapment efficiency, in vitro release behavior and storage stability at different temperature and simulated gastrointestinal tract conditions. The fluorescent microscopy study confirmed the higher particle uptake of TMC-NPs by gastrointestinal epithelium in comparison to the CS-NPs. The concentration of LMWH in the systemic circulation followed by oral administration of formulations was estimated using FXa chromogenic assay. A significant increase (p<0.05) in the oral bioavailability of LMWH was observed with TMC-NPs than both CS-NPs as well as plain LMWH solution. These findings suggested that TMC nanoparicles hold promise for oral delivery of LMWH and clinical applicability for the treatment of vascular disorders like deep vein thrombosis and pulmonary embolism, etc.

  9. Influence of Low Molecular Weight Fractions of Humic Substances on Their Reducing Capacities and Distribution of Redox Functional Groups.

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Jiang, J.

    2015-12-01

    Humic substances (HS) are redox-active organic compounds and their reducing capacities depend on molecule structure and distribution of redox functional groups (RFG). During dialysis experiments, initial HS were separated into low molecular weight fractions (LMWF, molecular weight <3,500 Da or <14,000 Da) and retentate. LMWF accounts for only 2% in TOC contents of HS molecules, while their reducing capacities are up to 33 times greater than those of initial HA. However, great amount of reducing capacities of LMWF does not cause decreasing reducing capacities of retentate relative to those of initial HA. Total reducing capacities of whole dialysis device were calculated for initial HA, retentate and LMWF in native and reduced state, and result suggests that releasing of LMWF leads to production and explosion of RFG. LWMF have great fluorescence intensities for protein-like fluorophores and humic acids-like fluorophores (quinone-like functional groups), where quinonoid π-π* transition is responsible for the great reducing capacities of LMWF. The 3,500 Da molecules (0.25 nm diameter) of HS are capable of stimulating transformation of redox-active metals or potential pollutants trapped in soil micropores (< 2 nm diameter). A development of relationship between reducing capacity and Ex / Em position provides a possibility to predicate relative reducing capacities of HS in treated raw water sample.

  10. Normal values for 24-h urinary protein excretion: total and low molecular weight proteins with a sex-related difference.

    PubMed

    Kawakami, H; Murakami, T; Kajii, T

    1990-05-01

    Urinary excretion of total and low molecular weight (LMW) (less than 40,000) proteins for a 24-h period was determined in 60 normal individuals, 30 men and 30 women, aged 21 to 44 years. 24-h urinary total protein excretion in men was 91.2 +/- 25.1 mg (mean +/- SD) (range: 40.2-146.8 mg), while that in women was 62.5 +/- 23.6 mg (range: 28.4-130.9 mg), as measured by a biuret method using bicinchoninic acid as a reagent. 24-h urinary LMW protein excretion in men was 37.3 +/- 13.6 mg (range: 12.7-62.7 mg), while that in women was 23.2 +/- 11.8 mg (range: 7.2-54.2 mg), as estimated by sodium dodecylsulfate-polyacrylamide gel electrophoresis of concentrated urine samples. Thus, a significantly higher (t-test, p less than 0.01) excretion of both the total and LMW proteins was found in men than in women. However, the percentage of the LMW proteins among the total proteins did not differ between the sexes: 40.3 +/- 7.5% (range: 21.7-54.9%) for men and 36.5 +/- 9.9% (range: 20.1-56.7%) for women.

  11. Quantitation of low molecular weight sugars by chemical derivatization-liquid chromatography/multiple reaction monitoring/mass spectrometry.

    PubMed

    Han, Jun; Lin, Karen; Sequria, Carita; Yang, Juncong; Borchers, Christoph H

    2016-07-01

    A new method for the separation and quantitation of 13 mono- and disaccharides has been developed by chemical derivatization/ultra-HPLC/negative-ion ESI-multiple-reaction monitoring MS. 3-Nitrophenylhydrazine (at 50°C for 60 min) was shown to be able to quantitatively derivatize low-molecular weight (LMW) reducing sugars. The nonreducing sugar, sucrose, was not derivatized. A pentafluorophenyl-bonded phase column was used for the chromatographic separation of the derivatized sugars. This method exhibits femtomole-level sensitivity, high precision (CVs of ≤ 4.6%) and high accuracy for the quantitation of LMW sugars in wine. Excellent linearity (R(2) ≥ 0.9993) and linear ranges of ∼500-fold for disaccharides and ∼1000-4000-fold for monosaccharides were achieved. With internal calibration ((13) C-labeled internal standards), recoveries were between 93.6% ± 1.6% (xylose) and 104.8% ± 5.2% (glucose). With external calibration, recoveries ranged from 82.5% ± 0.8% (ribulose) to 105.2% ± 2.1% (xylulose). Quantitation of sugars in two red wines and two white wines was performed using this method; quantitation of the central carbon metabolism-related carboxylic acids and tartaric acid was carried out using a previously established derivatization procedure with 3-nitrophenylhydrazine as well. The results showed that these two classes of compounds-both of which have important organoleptic properties-had different compositions in red and white wines.

  12. Hypersulfated low molecular weight heparin with reduced affinity for antithrombin acts as an anticoagulant by inhibiting intrinsic tenase and prothrombinase.

    PubMed

    Anderson, J A; Fredenburgh, J C; Stafford, A R; Guo, Y S; Hirsh, J; Ghazarossian, V; Weitz, J I

    2001-03-30

    In buffer systems, heparin and low molecular weight heparin (LMWH) directly inhibit the intrinsic factor X-activating complex (intrinsic tenase) but have no effect on the prothrombin-activating complex (prothrombinase). Although chemical modification of LMWH, to lower its affinity for antithrombin (LA-LMWH) has no effect on its ability to inhibit intrinsic tenase, N-desulfation of LMWH reduces its activity 12-fold. To further explore the role of sulfation, hypersulfated LA-LMWH was synthesized (sLA-LMWH). sLA-LMWH is not only a 32-fold more potent inhibitor of intrinsic tenase than LA-LMWH; it also acquires prothrombinase inhibitory activity. A direct correlation between the extent of sulfation of LA-LMWH and its inhibitory activity against intrinsic tenase and prothrombinase is observed. In plasma-based assays of tenase and prothrombinase, sLA-LMWH produces similar prolongation of clotting times in plasma depleted of antithrombin and/or heparin cofactor II as it does in control plasma. In contrast, heparin has no effect in antithrombin-depleted plasma. When the effect of sLA-LMWH on various components of tenase and prothrombinase was examined, its inhibitory activity was found to be cofactor-dependent (factors Va and VIIIa) and phospholipid-independent. These studies reveal that sLA-LMWH acts as a potent antithrombin-independent inhibitor of coagulation by attenuating intrinsic tenase and prothrombinase.

  13. Transdermal delivery of low molecular weight heparin loaded in flexible liposomes with bioavailability enhancement: comparison with ethosomes.

    PubMed

    Song, Yun-Kyoung; Hyun, Seo Yeon; Kim, Hyung-Tae; Kim, Chong-Kook; Oh, Jung-Mi

    2011-01-01

    Low molecular weight heparin (LMWH)-loaded flexible liposomes (flexosomes) were formulated for transdermal delivery, and their physicochemical and pharmacokinetic parameters were compared with LMWH-loaded ethosomes. Flexosomes had similar particle size compared with ethosomes, but their deformability was higher than that of ethosomes (76.7% vs. 46.8%). In vitro, flexosomes demonstrated 2.6-fold higher permeability coefficient than ethosomes. In comparison to LMWH aqueous solution, skin deposition of flexosome increased 3.2-fold, while that of ethosome increased only 2.0-fold. In vivo, after the topical application of flexosome to hairless mouse, [anti-Xa](max) was 1.11 IU/mL, while ethosomes showed only 0.32 IU/mL. Moreover, AUC(0-24 h) of flexosomes was 2.5-fold higher than ethosomes. In conclusion, the enhanced skin permeation and bioavailability of LMWH can be achieved with flexosomes in comparison with ethosomes. The LMWH transdermal delivery via flexosomes has the potential to replace the parenteral dosage forms for the treatment of venous thromboembolism, pulmonary embolism and cardiovascular events. PMID:21425940

  14. Molecular characterization of low molecular weight dissolved organic matter in water reclamation processes using Orbitrap mass spectrometry.

    PubMed

    Phungsai, Phanwatt; Kurisu, Futoshi; Kasuga, Ikuro; Furumai, Hiroaki

    2016-09-01

    Reclaimed water has recently become an important water source for urban use, but the composition of dissolved organic matter (DOM) in reclaimed water has rarely been characterized at the compound level because of its complexity. In this study, the transformation and changes in composition of low molecular weight DOM in water reclamation processes, where secondary effluent of the municipal wastewater treatment plant was further treated by biofiltration, ozonation and chlorination, were investigated by "unknown" screening analysis using Orbitrap mass spectrometry (Orbitrap MS). The intense ions were detected over an m/z range from 100 to 450. In total, 2412 formulae with various heteroatoms were assigned, and formulae with carbon (C), hydrogen (H) and oxygen (O) only and C, H, O and sulfur (S) were the most abundant species. During biofiltration, CHO-only compounds with relatively high hydrogen to carbon (H/C) ratio or with saturated structure were preferentially removed, while CHOS compounds were mostly removed. Ozonation induced the greatest changes in DOM composition. CHOS compounds were mostly decreased after ozonation while ozone selectively removed CHO compounds with relatively unsaturated structure and produced compounds that were more saturated and with a higher degree of oxidation. After chlorination, 168 chlorine-containing formulae, chlorinated disinfection by-products (DBPs), were additionally detected. Candidate DBP precursors were determined by tracking chlorinated DBPs formed via electrophilic substitution, half of which were generated during the ozonation. PMID:27235773

  15. Biodegradation of low-molecular-weight alkanes under mesophilic, sulfate-reducing conditions: metabolic intermediates and community patterns.

    PubMed

    Savage, Kristen N; Krumholz, Lee R; Gieg, Lisa M; Parisi, Victoria A; Suflita, Joseph M; Allen, Jon; Philp, R Paul; Elshahed, Mostafa S

    2010-06-01

    We evaluated the ability of the native microbiota in a low-temperature, sulfidic natural hydrocarbon seep (Zodletone) to metabolize short-chain hydrocarbons. n-Propane and n-pentane were metabolized under sulfate-reducing conditions in initial enrichments and in sediment-free subcultures. Carbon isotope analysis of residual propane in active enrichments showed that propane became enriched in (13)C by 6.7 (+/-2.0) per thousand, indicating a biological mechanism for propane loss. The detection of n-propylsuccinic and isopropylsuccinic acids in active propane-degrading enrichments provided evidence for anaerobic biodegradation via a fumarate addition pathway. A eubacterial 16S rRNA gene survey of sediment-free enrichments showed that the majority of the sequenced clones were phylogenetically affiliated within the Deltaproteobacteria. Such sequences were most closely affiliated with clones retrieved from hydrocarbon-impacted marine ecosystems, volatile fatty acid metabolizers, hydrogen users, and with a novel Deltaproteobacterial lineage. Other cloned sequences were affiliated with the Firmicutes and Chloroflexi phyla. The sequenced clones were only distantly (<95%) related to other reported low-molecular-weight alkane-degrading sulfate-reducing populations. This work documents the potential for anaerobic short-chain n-alkane metabolism for the first time in a terrestrial environment, provides evidence for a fumarate addition mechanism for n-propane activation under these conditions, and reveals microbial community members present in such enrichments.

  16. Low-molecular weight carbohydrates modulate dormancy and are required for post-germination growth in turions of Spirodela polyrhiza.

    PubMed

    Appenroth, K-J; Palharini, L; Ziegler, P

    2013-03-01

    The aquatic duckweed Spirodela polyrhiza propagates itself vegetatively by forming turions - bud-like perennation organs - in the autumn, which spend the winter on the bottom of ponds and then germinate in the following spring and proliferate on the water surface. Newly formed turions usually require a period of cold after-ripening and light to germinate effectively, but an ample supply of exogenous sugar can lead to germination even in the dark and independent of after-ripening. The results of the present study indicate that the availability of readily metabolised carbohydrates is a determining factor for turion germination. Freshly harvested turions do not contain soluble, low-molecular weight carbohydrates at a level sufficient to allow germination to take place, but after-ripened turions do. Augmentation of the soluble carbohydrate content during after-ripening derives from gradual breakdown of reserve starch of the turions. The long time required for any germination to be observed in turions incubated in darkness and the limited frequency of germination in the dark (about 50% of turion population), even with an ample external sugar, supply emphasise that both after-ripening and light are essential for ensuring rapid germination and subsequent frond proliferation at an ecologically appropriate time. The carbohydrate supply required for rapid proliferation of the fronds produced at germination is provided by the rapid light-induced breakdown of turion reserve starch. PMID:22686442

  17. Low molecular weight molecules of oyster nacre induce mineralization of the MC3T3-E1 cells.

    PubMed

    Rousseau, Marthe; Boulzaguet, Hélène; Biagianti, Julie; Duplat, Denis; Milet, Christian; Lopez, Evelyne; Bédouet, Laurent

    2008-05-01

    The nacre layer from the pearl oyster shell is considered as a promising osteoinductive biomaterial. Nacre contains one or more signal molecules capable of stimulating bone formation. The identity and the mode of action of these molecules on the osteoblast differentiation were analyzed. Water-soluble molecules from nacre were fractionated according to dialysis, solvent extraction, and reversed-phase HPLC. The activity of a fraction composed of low molecular weight molecules in the mineralization of the MC3T3-E1 extracellular matrix was investigated. Mineralization of the preosteoblast cells was monitored according to alizarin red staining, Raman spectroscopy, scanning electron microscopy, and quantitative RT-PCR. Molecules isolated from nacre, ranging from 50 to 235 Da, induced a red alizarin staining of the preosteoblasts extracellular matrix after 16 days of culture. Raman spectroscopy demonstrated the presence of hydroxyapatite (HA) in samples treated with these molecules. Scanning electron microscopy pictures showed at the surface of the treated cells the occurrence of clusters of spherical particles resembling to HA. The treatment of cells with nacre molecules accelerated expression of collagen I and increased the mRNA expression of Runx2 and osteopontin. This study indicated that the nacre molecules efficient in bone cell differentiation are certainly different from proteins, and could be useful for in vivo bone repair.

  18. Influence of Molecular Weight and Degree of Deacetylation of Low Molecular Weight Chitosan on the Bioactivity of Oral Insulin Preparations

    PubMed Central

    Qinna, Nidal A.; Karwi, Qutuba G.; Al-Jbour, Nawzat; Al-Remawi, Mayyas A.; Alhussainy, Tawfiq M.; Al-So’ud, Khaldoun A.; Al Omari, Mahmoud M. H.; Badwan, Adnan A.

    2015-01-01

    The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin polyelectrolyte complexes were constructed and their ability to reduce blood glucose was assessed in vivo on diabetic rats. Upon acid depolymerization and testing by viscosity method, three molecular weights of LMWC namely, 1.3, 13 and 18 kDa were obtained. As for the DDA, three LMWCs of 55%, 80% and 100% DDA were prepared and characterized by spectroscopic methods for each molecular weight. The obtained LMWCs showed different morphological and in silico patterns. Following complexation of LMWCs with insulin, different aggregation sizes were obtained. Moreover, the in vivo tested formulations showed different activities of blood glucose reduction. The highest glucose reduction was achieved with 1.3 kDa LMWC of 55% DDA. The current study emphasizes the importance of optimizing the molecular weight along with the DDA of the incorporated LMWC in oral insulin delivery preparations in order to ensure the highest performance of such delivery systems. PMID:25826718

  19. Tuning the superstructure of ultrahigh-molecular-weight polyethylene/low-molecular-weight polyethylene blend for artificial joint application.

    PubMed

    Xu, Ling; Chen, Chen; Zhong, Gan-Ji; Lei, Jun; Xu, Jia-Zhuang; Hsiao, Benjamin S; Li, Zhong-Ming

    2012-03-01

    An easy approach was reported to achieve high mechanical properties of ultrahigh-molecular-weight polyethylene (UHMWPE)-based polyethylene (PE) blend for artificial joint application without the sacrifice of the original excellent wear and fatigue behavior of UHMWPE. The PE blend with desirable fluidity was obtained by melt mixing UHMWPE and low molecular weight polyethylene (LMWPE), and then was processed by a modified injection molding technology-oscillatory shear injection molding (OSIM). Morphological observation of the OSIM PE blend showed LMWPE contained well-defined interlocking shish-kebab self-reinforced superstructure. Addition of a small amount of long chain polyethylene (2 wt %) to LMWPE greatly induced formation of rich shish-kebabs. The ultimate tensile strength considerably increased from 27.6 MPa for conventional compression molded UHMWPE up to 78.4 MPa for OSIM PE blend along the flow direction and up to 33.5 MPa in its transverse direction. The impact strength of OSIM PE blend was increased by 46% and 7% for OSIM PE blend in the direction parallel and vertical to the shear flow, respectively. Wear and fatigue resistance were comparable to conventional compression molded UHMWPE. The superb performance of the OSIM PE blend was originated from formation of rich interlocking shish-kebab superstructure while maintaining unique properties of UHMWPE. The present results suggested the OSIM PE blend has high potential for artificial joint application.

  20. Advances in the understanding of low molecular weight silicon formation and implications for control by AMC filters

    NASA Astrophysics Data System (ADS)

    Lobert, Jürgen M.; Cate, Philip W.; Ruede, David J.; Wildgoose, Joseph R.; Miller, Charles M.; Gaudreau, John C.

    2010-03-01

    Trimethylsilanol (TMS) is a low molecular weight / low boiling point silicon-containing, airborne contaminant that has received increased interest over the past few years as an important cause for contamination of optical surfaces in lithography equipment. TMS is not captured well by carbon-based filters, and hexamethyldisiloxane (HMDSO), even though captured well, can be converted to TMS when using acidic filter media commonly used for ammonia removal. TMS and HMDSO co-exist in a chemical equilibrium, which is affected by the acidity and moisture of their environment. This publication shows that HMDSO is converted to TMS by acidic media at concentrations typically found in cleanroom environments. This is contrary to published results that show a re-combination of TMS to HMDSO on acid media. We also demonstrate that, based on its conversion to TMS, HMDSO is not a suitable test compound for hybrid chemical filter performance, as the apparent lifetime/capacity of the filter can be substantially skewed towards larger numbers when conversion to TMS is involved. We show lifetime test results with toluene and HMDSO on acidic and non-acidic filter media. Appropriately designed, asymmetric hybrid chemical filters significantly minimize or eliminate the conversion of HMDSO to TMS, thereby reducing the risk to scanner optical elements. Similarly, such filters can also prevent or reduce acid-sensitive reactions of other AMC when passing through filter systems.

  1. Evalution of capillary electrophoresis-frontal analysis for the study of low molecular weight drug-human serum albumin interactions.

    PubMed

    Østergaard, Jesper; Schou, Christian; Larsen, Claus; Heegaard, Niels H H

    2002-09-01

    Capillary electrophoresis frontal analysis was applied to 12 low molecular weight compounds including 8 drug substances displaying a range of different properties with respect to binding affinity, binding location, structure, lipophilicity, charge at physiological pH, and electrophoretic mobility. It was found that capillary electrophoresis frontal analysis can be used as a general method to study and quantify drug-human serum albumin interactions. The binding parameters obtained were consistent with literature values. Dextran was in some cases added to the run buffer to improve separation of the drug and human serum albumin plateau peaks. Results indicate that mobility differences between free and complexed human serum albumin give rise to only minor errors. Capillary electrophoresis frontal analysis was also found applicable to the study of human serum albumin drug displacement reactions. Low sensitivity of the UV-detection system was found to be the major limitation of capillary electrophoresis frontal analysis. The method is simple, and minimal effort has to be put into method development, which makes it well suited for screening in early drug development.

  2. High-speed memory switching of liquid crystalline copolymer/low-molecular-weight liquid crystal composite systems

    NASA Astrophysics Data System (ADS)

    Kajiyama, Tisato; Yamane, Hirokazu; Kikuchi, Hirotsugu

    1997-04-01

    Reversible and bistable electro-optical switching characteristics have been investigated for induced smectic composite systems composed of side chain type nematic liquid crystalline polymer (nematic LCP) or its copolymer with weak polar methoxy terminal groups in the side chains and low molecular weight nematic liquid crystals (nematic LCs) with strong polar cyano end group. The liquid crystalline copolymer (LCcoP) with weak polar methoxy terminal groups in the side chains was used in order to improve the response speed of the bistable and reversible light switching for the binary composite system at room temperature. Although the LCcoP with 52.5 mol% substituted mesogenic side chains did not exhibit any mesophase characteristics at any temperature, this LCcoP induced a smectic state by mixing nematic LCs. A reversible and bistable electro-optical switching with a short response time (approximately 100 ms) was realized for the induced smectic binary composite system upon application of an appropriate electric field at room temperature.

  3. Ozonolysis of the double bond of the unsaturated uronate residue in low-molecular-weight heparin and K5 heparosan.

    PubMed

    Masuko, Sayaka; Higashi, Kyohei; Wang, Zhenyu; Bhaskar, Ujjwal; Hickey, Anne Marie; Zhang, Fuming; Toida, Toshihiko; Dordick, Jonathan S; Linhardt, Robert J

    2011-09-27

    Ozone is known to add across and cleave carbon-carbon double bonds. Ozonolysis is widely used for the preparation of pharmaceuticals, for bleaching substances and for killing microorganisms in air and water sources. Some polysaccharides and oligosaccharides, such as those prepared using chemical or enzymatic β-elimination, contain a site of unsaturation. We examined ozonolysis of low-molecular-weight heparins (LMWHs), enoxaparin and logiparin, and heparosan oligo- and polysaccharides for the removal of the nonreducing terminal unsaturated uronate residue. 1D (1)H NMR showed that these ozone-treated polysaccharides retained the same structure as the starting polysaccharide, except that the C4-C5 double bond in the nonreducing end unsaturated uronate had been removed. The anticoagulant activity of the resulting product from enoxaparin and logiparin was comparable to that of the starting material. These results demonstrate that ozonolysis is an important tool for the removal of unsaturated uronate residues from LMWHs and heparosan without modification of the core polysaccharide structure or diminution of anticoagulant activity. This reaction also has potential applications in the chemoenzymatic synthesis of bioengineered heparin from Escherichia coli-derived K5 heparosan.

  4. Alkane-modified low-molecular-weight polyethylenimine with enhanced gene silencing for siRNA delivery.

    PubMed

    Guo, Gaoyang; Zhou, Li; Chen, Zhifei; Chi, Weilin; Yang, Xiuqun; Wang, Wei; Zhang, Biliang

    2013-06-25

    Small interfering RNA (siRNA) has tremendous potential as a therapeutic agent for diverse diseases; however, due to its susceptibility to degradation and poor cellular uptake, the low efficiency of administration has been the most important limiting factor for clinical applications of siRNA. Herein, we synthesized alkyl chain modified low-molecular-weight polyethylenimines (LMW PEIs) and found that hydrophobically modified PEIs displayed enhanced efficiency in siRNA-mediated knockdown of target genes. To elucidate the mechanism for increased delivery, we characterized the polymers' physicochemical properties and bioactivity via nuclear magnetic resonance (NMR), gel retardation assay, dynamic laser scattering (DLS) analysis, confocal laser scanning microscopy and flow cytometry. The hydrophobic modification reduced siRNA binding affinity but facilitated the formation of nanoparticles in contrast to the original PEI. The PEIs with eight and thirteen alkyl tails were able to self-assemble into nanoparticles and yielded higher cellular uptake, which leaded to even similar efficiencies of 80-90% knockdown as Lipofectamine™ 2000 control. These results suggested that the status of polymers in aqueous solution, which depended on the degree of hydrophobic modification, played an important role in the uptake of siRNA. Therefore, we provided new information on the role of hydrophobic content in the enhanced gene silencing activity.

  5. Novel microencapsulation of potential drugs with low molecular weight and high hydrophilicity: hydrogen peroxide as a candidate compound.

    PubMed

    Ng, Sing-Muk; Choi, Jeong-Yeon; Han, Hyung-Soo; Huh, Jeung-Soo; Lim, Jeong Ok

    2010-01-15

    Microencapsulation of drugs into solid biodegradable polymeric microspheres via solvent evaporation technique remains challenging especially with those having low molecular weight and high hydrophilicity nature. This paper presents an efficient encapsulation protocol for this group of drugs, demonstrated using hydrogen peroxide as a model compound that is encapsulated into poly(lactic-co-glycolic acid) microspheres. Hydrogen peroxide can be employed as antiseptic agent or its decomposed form into oxygen can be useful in various pharmaceutical applications. The new encapsulation technique was developed based on the modification of conventional double emulsion and solvent evaporation protocol with a backward concentration gradient of hydrogen peroxide. This was achieved by adding and controlling the concentration of hydrogen peroxide at the continuous phase during the solidification stage of the microspheres. Parameters involved in the production and the formulation aspect were optimized to achieve the best protocol having controlled efficiency of encapsulation that is simple, safe, practical, and economical. Evaluation on the encapsulation efficiency and the release profile has been made indirectly by monitoring the dissolved oxygen level of the solution where the microspheres were incubated. Morphology of the microspheres was investigated using scanning electron microscopy. This proposed method has successfully used to prepare batches of microspheres having different encapsulation efficiencies and its potential applications have been demonstrated accordingly.

  6. Low molecular weight chitosan-coated polymeric nanoparticles for sustained and pH-sensitive delivery of paclitaxel.

    PubMed

    Abouelmagd, Sara A; Ku, Youn Jin; Yeo, Yoon

    2015-01-01

    Low molecular weight chitosan (LMWC) is a promising polymer for surface modification of nanoparticles (NPs), which can impart both stealth effect and electrostatic interaction with cells at mildly acidic pH of tumors. We previously produced LMWC-coated NPs via covalent conjugation to poly(lactic-co-glycolic) acid (PLGA-LMWC NPs). However, this method had several weaknesses including inefficiency and complexity of the production as well as increased hydrophilicity of the polymer matrix, which led to poor drug release control. Here, we used the dopamine polymerization method to produce LMWC-coated NPs (PLGA-pD-LMWC NPs), where the core NPs were prepared with PLGA that served best to load and retain drugs and then functionalized with LMWC via polydopamine layer. The PLGA-pD-LMWC NPs overcame the limitations of PLGA-LMWC NPs while maintaining their advantages. First of all, PLGA-pD-LMWC NPs attenuated the release of paclitaxel to a greater extent than PLGA-LMWC NPs. Moreover, PLGA-pD-LMWC NPs had a pH-dependent surface charge profile and cellular interactions similar to PLGA-LMWC NPs, enabling acid-specific NP-cell interaction and enhanced drug delivery to cells in weakly acidic environment. Although the LMWC layer did not completely prevent protein binding in serum solution, PLGA-pD-LMWC NPs showed less phagocytic uptake than bare PLGA NPs.

  7. Low molecular weight heparin mediating targeting of lymph node metastasis based on nanoliposome and enzyme-substrate interaction.

    PubMed

    Ye, Tiantian; Jiang, Xuewei; Li, Jing; Yang, Rui; Mao, Yuling; Li, Kai; Li, Liang; Chen, Fen; Yao, Jianhua; Wu, Yingliang; Yang, Xinggang; Wang, Shujun; Pan, Weisan

    2015-05-20

    The aim of our study is to develop a new function of low molecular weight heparin (LMWHEP) for targeting tumor metastatic lymph node based on LMWHEP-modified nanoliposome and LMWHEP-heparanase (HPA) interaction (LMWHEP-HPA). At First, LMWHEP-modified nanoliposomes (LMWHEP-LPs) were prepared by the electrostatic attraction and the physiochemical properties were evaluated. Then the effects of LMWHEP-HPA on the stability and drug release were investigated. In addition, the cellular uptake of LMWHEP-LPs was studied by using Hela, MCF-7, L929 and RAW264.7 cells. Finally, the targeting ability as well as the tissue distribution was examined in the mice model bearing Hela tumor lymph node metastasis. LMWHEP-LPs prepared had suitable physicochemical properties. The effect results of LMWHEP-HPA showed that LMWHEP coated on the surface of nanoliposome could be degraded by HPA. Compared with the unmodified-nanoliposome, the LMWHEP modification could improve the cellular uptake and increase the targeting ability to the metastatic lymph nodes according to LMWHEP-HPA. This study demonstrates LMWHEP is a highly promising polymer material for the targeting of tumor lymph node metastasis.

  8. 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

  9. Stabilization of Ostwald ripening in low molecular weight amino lipid nanoparticles for systemic delivery of siRNA therapeutics.

    PubMed

    Gindy, Marian E; Feuston, Brad; Glass, Angela; Arrington, Leticia; Haas, R Matthew; Schariter, Joseph; Stirdivant, Steven M

    2014-11-01

    Lipid nanoparticles (LNPs) represent the most clinically advanced technology for the systemic delivery of therapeutic siRNA in vivo. Toward this end, a novel class of LNPs comprising low molecular weight (MW) ionizable amino lipids having asymmetric architecture was recently reported.1 LNPs of these amino lipids, termed asymmetric LNPs, were shown to be highly efficacious and well tolerated in vivo; advances were enabled by improved endosomal escape, coupled with enhanced amino lipid metabolism and clearance. In this work, we show that, in contrast to their desirable pharmacological performance, asymmetric LNPs present a significant pharmaceutical developability challenge, namely physical instability limiting extended shelf life. Using orthogonal characterization methods, we identify the mechanism of LNP instability as Ostwald ripening and establish it to be driven predominantly by the asymmetric amino lipid component. Through rational optimization of LNP physical and macromolecular properties, we are able to significantly attenuate or entirely eliminate the Ostwald ripening instability. Modulation of LNP size, for example, effectively halts particle growth. Similarly, optimization of LNP macromolecular packing through deliberate selection of structurally matched colipids significantly diminishes the rate of ripening. This later experimental observation is substantiated by molecular dynamics simulations of LNP self-assembly, which establish a quantitative dependence of LNP macromolecular order on colipid structure. In totality, the experimental and molecular dynamics outcomes of this work support the rational design of LNP physical and chemical properties leading to effective Ostwald ripening stabilization and enable the advance of asymmetric LNPs as a clinic-ready platform for siRNA therapeutics.

  10. Physicochemical properties and ecotoxicological effects of yttrium oxide nanoparticles in aquatic media: Role of low molecular weight natural organic acids.

    PubMed

    Zhang, Fan; Wang, Zhuang; Wang, Se; Fang, Hao; Chen, Mindong; Xu, Defu; Tang, Lili; Wang, Degao

    2016-05-01

    Understanding how engineered nanoparticles (ENPs) interact with natural organic acids is important to ecological risk assessment of ENPs, but this interaction remains poorly studied. Here, we investigate the dispersion stability, ion release, and toxicity of yttrium oxide nanoparticles (nY2O3) suspensions after exposure to two low molecular weight natural organic acids (LOAs), namely benzoic acid and gallic acid. We find that in the presence of LOAs the nY2O3 suspensions become more stable with surface zeta potential more positive or negative, accompanied by small agglomerated size. LOA interaction with nY2O3 is shown to promote the release of dissolved yttrium from the nanoparticles, depending on the concentrations of LOAs. Toxic effects of the nY2O3 suspensions incubated with LOAs on Scenedesmus obliquus as a function of their mixture levels show three types of signs: stimulation, inhibition, and alleviation. The mechanism of the effects of LOAs on the nY2O3 toxicity may be mainly associated with the degree of agglomeration, particle-induced oxidative stress, and dissolved yttrium. Our results stressed the importance of LOA impacts on the fate and toxicity of ENPs in the aquatic environment.

  11. Absorption enhancing effects of chitosan oligomers on the intestinal absorption of low molecular weight heparin in rats.

    PubMed

    Zhang, Hailong; Mi, Jie; Huo, Yayu; Huang, Xiaoyan; Xing, Jianfeng; Yamamoto, Akira; Gao, Yang

    2014-05-15

    Absorption enhancing effects of chitosan oligomers with different type and varying concentration on the intestinal absorption of low molecular weight heparin (LMWH) were examined by an in situ closed loop method in different intestinal sections of rats. Chitosan hexamer with the optimal concentration of 0.5% (w/v) showed the highest absorption enhancing ability both in the small intestine and large intestine. The membrane toxicities of chitosan oligomers were evaluated by morphological observation and determining the biological markers including amount of protein and activity of lactate dehydrogenase (LDH) released from intestinal epithelium cells. There was no obvious change both in levels of protein and LDH and morphology in the intestinal membrane between control and various chitosan oligomers groups, suggesting that chitosan oligomers did not induce any significant membrane damage to the intestinal epithelium. In addition, zeta potentials became less negative and amount of free LMWH gradually decreased when various chitosan oligomers were added to LMWH solution, revealing that electrostatic interaction between positively charged chitosan oligomers and negative LMWH was included in the absorption enhancing mechanism of chitosan oligomers. In conclusion, chitosan oligomers, especially chitosan hexamer, are safe and efficient absorption enhancers and can be used promisingly to improve oral absorption of LMWH.

  12. Effect of low molecular weight organic acids on phosphorus adsorption by ferric-alum water treatment residuals.

    PubMed

    Wang, Changhui; Wang, Ziyuan; Lin, Lu; Tian, Binghui; Pei, Yuansheng

    2012-02-15

    Effects of low molecular weight organic acids (LMWOAs; citric acid, oxalic acid and tartaric acid) on phosphorus (P) adsorption by ferric-alum water treatment residuals (FARs) were studied. Both batch and column experiments indicated that the effects of LMWOAs on P adsorption were closely related to adsorption time. Initially, all acids presented inhibitory function on P adsorption. The inhibition became weaker with time, eventually promoting P adsorption for citric acid and tartaric acid. In the column experiment with a 61-day duration, high P adsorption rates (>55%) were observed for the test groups containing citric acid and tartaric acid. Interestingly, higher pH likely enhanced P adsorption with the effects of LMWOAs and a distinct relationship between LMWOAs' effects on P adsorption and their concentrations was not observed. Moreover, fractionation of the adsorbed P from the FARs demonstrated that oxalic acid reduced P adsorption capacity, while citric acid and tartaric acid increased. Based on the forms of Fe and Al existing in the FARs and Fourier transform infrared spectroscopy analyses, LMWOAs can promote P adsorption through activating crystalline Fe/Al and preventing crystallization of amorphous Fe/Al to increase P adsorption sites, and can also inhibit P adsorption by competition with adsorption sites.

  13. Purification and biochemical properties of SDS-stable low molecular weight alkaline serine protease from Citrullus colocynthis.

    PubMed

    Khan, Muhammad Bashir; Khan, Hidayatullah; Shah, Muhammad Usman; Khan, Sanaullah

    2016-01-01

    A low molecular weight serine protease from seeds of Citrullus colocynthis was purified to electrophoretic homogeneity with high level of catalytic efficiency (22,945 M(-1) S(-1)). The enzyme was a monomer with molecular mass of 25 kDa estimated by SDS-PAGE. The enzyme was highly active over a pH range of 6.5-9.0 and temperature range of 20-80 °C, with maximum activity at pH 7.5 and at 50 °C. The K(m) and K(cat) were 73 μg/mL and 67/s, respectively. The enzyme was strongly inhibited by PMSF, moderately by soybean trypsin inhibitor, indicating that the enzyme was a serine protease. The enzyme retained 86 and 73% of its activity in the presence of urea and DTT, respectively, and its activity was slightly enhanced in the presence of anionic detergent (SDS). Thus, the enzyme is a novel SDS-stable protease with high catalytic efficiency over wide ranges of pH and temperature which is commercially promising for various industrial applications. PMID:26942486

  14. 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

  15. 2,5-hexanedione altered the degradation of low-molecular-weight neurofilament in rat nerve tissues.

    PubMed

    Song, Fuyong; Zhang, Qingguo; Kou, Ruirui; Zou, Chaoshuang; Gao, Yuan; Xie, Keqin

    2012-12-01

    Occupational exposure to n-hexane produces a central-peripheral distal axonopathy, which is characterized by giant axonal swellings filled with neurofilaments (NFs). To investigate the change of NFs degradation and their possible role in n-hexane neuropathy, adult male Wistar rats were administered intraperitoneally at a dosage of 400 mg/kg/day 2,5-hexanedione (2,5-HD) for 4 weeks. The time course of low-molecular-weight neurofilament (NF-L) degradation and autophagy-related protein in rat sciatic nerves and spinal cords was determined by Western blotting. The results demonstrated that the administration of 2,5-HD inhibited NF-L degradation to an undetectable level in sciatic nerves. Furthermore, a significant reduction of NF-L degradation in spinal cords was observed in the early stage of 2,5-HD exposure. In the meantime, 2,5-HD significantly decreased the level of Beclin-1, a key autophagy-regulated protein in sciatic nerves of rats while increased the level of P62, a selective substrate of autophagy degrading pathway, which indicated a dysfunctional autophagy in rat nerve tissues. Collectively, our findings suggested that the inhibition of autophagy by 2,5-HD might be responsible for the reduction of NF-L degradation in rat sciatic nerves, and involved in the pathogenesis of 2,5-HD-induced axonopathy.

  16. A comparison of the sensitivity of APTT reagents to the effects of enoxaparin, a low-molecular weight heparin.

    PubMed

    Ip, B K; Thomson, A R; Moriarty, H T

    2001-08-01

    Low-molecular weight heparin (LMWH) is the product of enzymatic or chemical degradation of unfractionated heparin (UFH). It has been found to have better bio-availibility, more predictable dose response and can be used as an alternative to UFH for prophylaxis and treatment of thrombotic disorders. It is claimed that no laboratory monitoring is necessary for LMWH therapy; however, for the aged, renal impaired, obese or grossly underweight, monitoring of dose effect with anti-Xa assay is recommended. The activated partial thromboplastin time (APTT), which is the test of choice for UFH monitoring, is believed to be insensitive to the effect of LMWH. The sensitivity of the APTT to heparin lies in the APTT reagent used. In this study, eight different APTT reagents were used to compare the APTT with anti-Xa activity in ex vivo plasma from patients who were on enoxaparin (LMWH, Clexane) therapy. It was found that, as with UFH, APTT reagents show variable sensitivity to LMWH. The APTTs from all eight reagents were found to have a linear relationship to anti-Xa activity. The APTT results using three of the reagents gave an indication of the use of LMWH therapy. It was also found that patients who were lupus anticoagulant (LA)-positive had much more prolonged APTTs when on LMWH therapy; however, a linear correlation between APTT and anti-Xa was not present in these patients.

  17. The low molecular weight DNA diffusion assay as an indicator of cytotoxicity for the in vitro comet assay.

    PubMed

    Speit, Günter; Vesely, Alexandra; Schütz, Petra; Linsenmeyer, Regina; Bausinger, Julia

    2014-07-01

    The low molecular weight DNA diffusion assay (LMW assay) has been recommended as a measure for cytotoxicity for the in vivo comet assay. To better understand the relationship between effects in the LMW assay, DNA migration in the comet assay and effects in established cytotoxicity tests, we performed in vitro experiments with cultured human cell lines (TK6, A549) and comparatively investigated five test substances (methyl methanesulfonate, (±)-benzo[a]pyrene diol epoxide, sodium dodecyl sulphate, menthol and sodium arsenite). We measured DNA migration (tail intensity) in the comet assay and the frequency of 'hedgehogs' (cells with almost all DNA in the tail), DNA diffusion in the LMW assay, cell viability (trypan blue and fluorescein diacetate/ethidium bromide staining) and inhibition of proliferation (relative cell counts). Our in vitro experiments indicate that effects in the LMW assay occur independently from DNA effects in the comet assay and are not related to the occurrence of hedgehogs. Results from the LMW assay are in good agreement with results from viability assays and seem to allow discriminating genotoxic from non-genotoxic substances when appropriate preparation times are considered. Measurements of cytotoxicity by these methods only at an early preparation time after exposure to genotoxic substances may lead to erroneous results.

  18. Effect of a low-molecular-weight cross-linkable macromer on electrospinning of poly(lactide-co-glycolide) fibers.

    PubMed

    Xu, Weijie; He, Xuezhong; Sarvestani, Alireza S; Jabbari, Esmaiel

    2007-01-01

    A mixture of low-molecular-weight poly(L-lactide-co-glycolide ethylene oxide fumarate) (PLGEOF) macromer and high-molecular-weight poly(lactide-co-glycolide) (PLGA) was used to produce fibers by electrospinning. PLGEOF is a biodegradable and in situ cross-linkable terpolymer made from building blocks with excellent biocompatibility. PLGA provides the required elongational viscosity to the spinning jet while the unsaturated PLGEOF macromers contribute to in situ crosslinking of fibers and attachment of bioactive functional groups. Mechanical rheometry demonstrated that PLGEOF macromers cross-link in situ by ultraviolet radiation. The addition of PLGEOF macromer to PLGA solutions had a significant effect on size and morphology of the electrospun fibers. The morphology of the electrospun fibers changed from bead- to fiber-like with increasing PLGEOF concentration. As PLGEOF was added to 12 wt% PLGA solutions, the fiber diameter first decreased with 2% PLGEOF and then increased with the addition of 5% and 10% PLGEOF. Our results demonstrate that the fiber size initially is decreased with the addition of PLGEOF due to an increase in solution conductivity and then is increased with further PLGEOF addition due to higher viscosity of the polymerizing mixture. PMID:17961321

  19. [Effect of low molecular weight organic acids on Pb2+ adsorption and desorption by constant charge soil colloids].

    PubMed

    Yang, Yati; Wang, Xudong; Zhang, Yiping; Qu, Aihua

    2003-11-01

    The isothermal curves of Pb2+ adsorption-desorption by soil colloids followed Freundlich and Langmuir equation. The adsorption constant Ka showed the trend of old manured loessal soil > yellow loessal soil > dark cultivated loessal soil > yellow cinamon soil, which was consistent with surface charge density sigma 0, an indicator of the strength of Pb2+ adsorption by each soil colloid. Low molecular-weight organic acids (LMWOAs) made Pb2+ adsorbed amount decreased and adsorption affinity increased, and the effect of citric acid was larger than that of oxalic acid. The constant Kd of residual Pb2+ adsorption after desorption showed the trend of old manured loessal soil > yellow cinamon soil > dark cultivated loessal soil > yellow loessal soil, which reflected the adsorption strength of residual Pb2+ after desorption, and was related to the contents of organic matter and free ferric oxide. The isothermal curves of Pb2+ desorption from soil colloids were obvious higher than those of Pb2+ adsorption. In NaNO3 and oxalic acid background solution, the isothermal curves of Pb2+ adsorption were far away from those of Pb2+ desorption, showing that the hysteretic degree between adsorption and desorption was very large. The isothermal curves of Pb2+ desorption from soil colloids were closed to those of Pb2+ adsorption in citric acid background solution, which showed that the Pb adsorption and desorption was reversible.

  20. Low-molecular-weight adiponectin is more closely associated with disease activity of rheumatoid arthritis than other adiponectin multimeric forms.

    PubMed

    Li, Ping; Yang, Li; Ma, Cui-Li; Liu, Bo; Zhang, Xin; Ding, Rui; Bi, Li-qi

    2015-06-01

    Adiponectin is divided into high-molecular-weight (HMW), medium-molecular-weight (MMW), and low-molecular-weight (LMW) forms. These forms differ not only in the number of adiponectin molecules but also in their biological activity. There are conflicting findings regarding the role of adiponectin in rheumatoid arthritis (RA). Moreover, few reports have described the relationships between serum adiponectin multimers levels and RA. Therefore, we examined the association of total adiponectin and its multimers with RA. Two study groups were examined: 180 recently diagnosed untreated RA patients with disease duration less than 1 year (RA group) and 160 age- and sex-matched control subjects (control group). RA-related factors, blood pressure, body mass index, glucose, complete lipid profile, and adiponectin multimers were measured. The levels of total adiponectin and each multimer of adiponectin were significantly lower in the RA than in the control (P < 0.01). Serum levels of total, HMW, MMW, and LMW were positively correlated with triglycerides levels and negatively correlated with the Disease Activity Score for 28 joints (DAS28). Multivariate regression analysis showed that total, HMW, and MMW adiponectin were independently associated with serum triglycerides level. LMW adiponectin was independently correlated with serum triglycerides level and DAS28. The decreased LMW adiponectin levels may be associated with disease activity of RA.

  1. Molecular characterization of low molecular weight dissolved organic matter in water reclamation processes using Orbitrap mass spectrometry.

    PubMed

    Phungsai, Phanwatt; Kurisu, Futoshi; Kasuga, Ikuro; Furumai, Hiroaki

    2016-09-01

    Reclaimed water has recently become an important water source for urban use, but the composition of dissolved organic matter (DOM) in reclaimed water has rarely been characterized at the compound level because of its complexity. In this study, the transformation and changes in composition of low molecular weight DOM in water reclamation processes, where secondary effluent of the municipal wastewater treatment plant was further treated by biofiltration, ozonation and chlorination, were investigated by "unknown" screening analysis using Orbitrap mass spectrometry (Orbitrap MS). The intense ions were detected over an m/z range from 100 to 450. In total, 2412 formulae with various heteroatoms were assigned, and formulae with carbon (C), hydrogen (H) and oxygen (O) only and C, H, O and sulfur (S) were the most abundant species. During biofiltration, CHO-only compounds with relatively high hydrogen to carbon (H/C) ratio or with saturated structure were preferentially removed, while CHOS compounds were mostly removed. Ozonation induced the greatest changes in DOM composition. CHOS compounds were mostly decreased after ozonation while ozone selectively removed CHO compounds with relatively unsaturated structure and produced compounds that were more saturated and with a higher degree of oxidation. After chlorination, 168 chlorine-containing formulae, chlorinated disinfection by-products (DBPs), were additionally detected. Candidate DBP precursors were determined by tracking chlorinated DBPs formed via electrophilic substitution, half of which were generated during the ozonation.

  2. Influence of molecular weight and degree of deacetylation of low molecular weight chitosan on the bioactivity of oral insulin preparations.

    PubMed

    Qinna, Nidal A; Karwi, Qutuba G; Al-Jbour, Nawzat; Al-Remawi, Mayyas A; Alhussainy, Tawfiq M; Al-So'ud, Khaldoun A; Al Omari, Mahmoud M H; Badwan, Adnan A

    2015-03-27

    The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin polyelectrolyte complexes were constructed and their ability to reduce blood glucose was assessed in vivo on diabetic rats. Upon acid depolymerization and testing by viscosity method, three molecular weights of LMWC namely, 1.3, 13 and 18 kDa were obtained. As for the DDA, three LMWCs of 55%, 80% and 100% DDA were prepared and characterized by spectroscopic methods for each molecular weight. The obtained LMWCs showed different morphological and in silico patterns. Following complexation of LMWCs with insulin, different aggregation sizes were obtained. Moreover, the in vivo tested formulations showed different activities of blood glucose reduction. The highest glucose reduction was achieved with 1.3 kDa LMWC of 55% DDA. The current study emphasizes the importance of optimizing the molecular weight along with the DDA of the incorporated LMWC in oral insulin delivery preparations in order to ensure the highest performance of such delivery systems.

  3. Mechanism study of endothelial protection and inhibits platelet activation of low molecular weight fucoidan from Laminaria japonica

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline (0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. vWF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce vWF level in vascular endothelial injury rats and also significantly reduce vWF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and vWF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

  4. M118--a rationally engineered low-molecular-weight heparin designed specifically for the treatment of acute coronary syndromes.

    PubMed

    Kishimoto, Takashi Kei; Qi, Yi Wei; Long, Alison; Capila, Ishan; Sasisekharan, Ram; Guerrero, Luis; Fier, Ian; Roach, James; Venkataraman, Ganesh

    2009-11-01

    The initial choice of anticoagulant therapy administered in emergency departments for acute coronary syndromes (ACS) has important consequences for subsequent patient care, as neither unfractionated heparin (UFH) nor low-molecular-weight heparin (LMWH) are ideally suited for all potential clinical treatment pathways. UFH remains widely used for surgical interventions because of the ability to rapidly reverse its anticoagulant activity. However, the unpredictable pharmacokinetic profile of UFH presents safety issues, and the low subcutaneous bioavailability limits the utility of UFH for patients who are medically managed. LMWH has superior pharmacokinetic properties, but its anticoagulant activity cannot be effectively monitored or reversed during surgery. There is an unmet medical need for a baseline anticoagulant therapy that addresses these shortcomings while retaining the beneficial properties of both UFH and LMWH. We describe here M118, a novel LMWH designed specifically for use in the treatment of ACS. M118 shows broad anticoagulant activity, including potent activity against both factor Xa (~240 IU/mg) and thrombin (factor IIa; ~170 IU/mg), low polydispersity, high (78%) subcutaneous bioavailability in rabbits, and predictable subcutaneous and intravenous pharmacokinetics. Additionally, the anticoagulant activity of M118 is monitorable by standard coagulation assays and is reversible with protamine. M118 demonstrates superior activity to conventional LMWH in a rabbit model of abdominal arterial thrombosis without increasing bleeding risk, and is currently being evaluated in a phase II clinical trial evaluating efficacy and safety in patients undergoing percutaneous coronary intervention. PMID:19888526

  5. Effects of low molecular weight chondroitin sulfate on type II collagen-induced arthritis in DBA/1J mice.

    PubMed

    Cho, So Yean; Sim, Joon-Soo; Jeong, Choon Sik; Chang, Seung Yeup; Choi, Don Woong; Toida, Toshihiko; Kim, Yeong Shik

    2004-01-01

    In order to evaluate the improvement in the treatment of chronic arthritis, we investigated chondroitin sulfate depolymerization product (low molecular weight chondroitin sulfate, LMWCS) and intact chondroitin sulfate (CS) in vitro and in vivo. LMWCS was prepared by a chemical depolymerization process induced by hydrogen peroxide in the presence of copper salts. LMWCS (300 mg/kg) and CS (1200 mg/kg) were orally administered to DBA/1J mice once daily for 14 d prior to initial immunization with type II collagen. Their elastase activities and the production of cytokines in sera were examined on type II collagen-induced arthritis in DBA/1J mice. We also compared the paracellular transport of LMWCS and CS across Caco-2 cell monolayers and examined the inhibitory effects on elastase activities. LMWCS inhibited elastase activity slightly, but CS did not show inhibition. Hind paw edema was significantly decreased by LMWCS treatment. Levels of anti-type II collagen antibody and tumor necrosis factor-alpha (TNF-alpha) in sera were also reduced by LMWCS treatment but not in case of CS, although no significant difference was observed between LMWCS and CS on interleukin-6 (IL-6) induction. The LMWCS preparation showed preventive effects on the type II collagen-induced arthritis in DBA/1J mice and better permeability through Caco-2 cells. PMID:14709897

  6. Purification and biochemical properties of SDS-stable low molecular weight alkaline serine protease from Citrullus colocynthis.

    PubMed

    Khan, Muhammad Bashir; Khan, Hidayatullah; Shah, Muhammad Usman; Khan, Sanaullah

    2016-01-01

    A low molecular weight serine protease from seeds of Citrullus colocynthis was purified to electrophoretic homogeneity with high level of catalytic efficiency (22,945 M(-1) S(-1)). The enzyme was a monomer with molecular mass of 25 kDa estimated by SDS-PAGE. The enzyme was highly active over a pH range of 6.5-9.0 and temperature range of 20-80 °C, with maximum activity at pH 7.5 and at 50 °C. The K(m) and K(cat) were 73 μg/mL and 67/s, respectively. The enzyme was strongly inhibited by PMSF, moderately by soybean trypsin inhibitor, indicating that the enzyme was a serine protease. The enzyme retained 86 and 73% of its activity in the presence of urea and DTT, respectively, and its activity was slightly enhanced in the presence of anionic detergent (SDS). Thus, the enzyme is a novel SDS-stable protease with high catalytic efficiency over wide ranges of pH and temperature which is commercially promising for various industrial applications.

  7. Purification and chromium-excretory function of low-molecular-weight, chromium-binding substances from dog liver.

    PubMed

    Wada, O; Wu, G Y; Yamamoto, A; Manabe, S; Ono, T

    1983-10-01

    From liver of dogs injected iv with potassium dichromate (38 mg/kg body wt), a low-molecular-weight chromium-binding substance (LMCr) was purified into two subfractions, LMCr I and LMCr II, which differ in physical and chemical properties. LMCr I was identified to be an anionic, organic chromium compound with a molecular weight of 1500. It contained glutamic acid, glycine, and cysteine as the predominant amino acids and firmly bound chromium in a ratio of one chromium(III) to one molecule of LMCr I. LMCr II was isolated in crystalline form and demonstrated to be a water-soluble, inorganic chromium(III) complex consisting of Na2HPO4 . 7H2O and Na2HPO4 . 2H2O. Although its crystallization reduced the chromium content, it had a maximum chromium-binding capacity as much as one chromium per one phosphorus in water. The mixture of LMCr I and LMCr II as approximated to be the natural composition showed a lower acute toxicity as measured by lethality in mice and had higher rates of urinary excretion and renal clearance in rabbits, accompanied by lower rates of renal tubular reabsorption and retention in kidney and liver than potassium dichromate(VI) and chromium(III) chloride. Pretreatment with chromium-free LMCr II remarkably reduced the mortality rates of mice acutely poisoned with chromium chloride. These results indicate that LMCr plays an important role in the detoxification and excretion of chromium in mammals. PMID:6617615

  8. Photoalignment and resulting holographic vector grating formation in composites of low molecular weight liquid crystals and photoreactive liquid crystalline polymers

    NASA Astrophysics Data System (ADS)

    Sasaki, Tomoyuki; Shoho, Takashi; Goto, Kohei; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2015-08-01

    Polarization holographic gratings were formed in liquid crystal (LC) cells fabricated from a mixture of low molecular weight nematic LC and a photoreactive liquid crystalline polymer (PLCP) with 4-(4-methoxycinnamoyloxy)biphenyl side groups. The diffraction properties of the gratings were analyzed using theoretical models which were determined based on the polarization patterns of the polarization holography. The results demonstrated that vector gratings comprised of periodic orientation distributions of the LC molecule were induced in the cells based on the axis-selective photoreaction of the PLCP. The vector gratings were erased by applying a sufficiently high voltage to the cells and then were reformed with no hysteresis after the voltage was removed. This phenomenon suggested that the PLCP molecules were stabilized based on the axis-selective photocrosslink reaction and that the LC molecules were aligned by the photocrosslinked PLCP. This LC composite with axis-selective photoreactivity is useful for various optical applications, because of their stability, transparency, and response to applied voltage.

  9. Nanowires formed by the co-assembly of a negatively charged low-molecular weight gelator and a zwitterionic polythiophene.

    PubMed

    Li, Feng; Palaniswamy, Ganesan; de Jong, Menno R; Aslund, Andreas; Konradsson, Peter; Marcelis, Antonius T M; Sudhölter, Ernst J R; Stuart, Martien A Cohen; Leermakers, Frans A M

    2010-06-21

    Conjugated organic nanowires have been prepared by co-assembling a carboxylate containing low-molecular weight gelator (LMWG) and an amino acid substituted polythiophene derivative (PTT). Upon introducing the zwitterionic polyelectrolyte PTT to a basic molecular solution of the organogelator, the negative charges on the LMWG are compensated by the positive charges of the PTT. As a result, nanowires form through co-assembly. These nanowires are visualized by both transmission electron microscopy (TEM) and atomic force microscopy (AFM). Depending on the concentration and ratio of the components these nanowires can be micrometers long. These measurements further suggest that the aggregates adopt a helical conformation. The morphology of these nanowires are studied with fluorescent confocal laser scanning microscopy (CLSM). The interactions between LMWG and PTT are characterized by steady-state and time-resolved fluorescence spectroscopy studies. The steady-state spectra indicate that the backbone of the PTT adopts a more planar and more aggregated conformation when interacting with LMWG. The time- resolved fluorescence decay studies confirm this interpretation.

  10. Identification of selenosugars and other low-molecular weight selenium metabolites in high-selenium cereal crops.

    PubMed

    Aureli, Federica; Ouerdane, Laurent; Bierla, Katarzyna; Szpunar, Joanna; Prakash, Nagaraja Tejo; Cubadda, Francesco

    2012-08-01

    Several novel selenium containing compounds were characterized in staple crops (wheat, rice and maize) grown on soils naturally rich in selenium. A dedicated method based on the coupling of liquid chromatography with multiplexed detection (ICP-MS, ESI-Orbitrap MS(/MS)) was developed for the speciation of low-molecular weight (<5 kDa) selenium metabolites. Nine species present in different proportions as a function of the crop type were identified by cation-exchange HPLC-ESI-Orbitrap MS on the basis of the accurate molecular mass and MS/MS spectra. The natural origin of these species was then validated by varying extraction conditions and by using hydrophilic interaction LC (HILIC)-ESI-Orbitrap MS(/MS). Among the identified compounds, Se-containing monosaccharides (hexose moiety, m/z 317 and m/z 358) or Se-containing disaccharides (hexose-pentose moiety, m/z 407 and m/z 408) were the first selenosugars reported in edible plants. It is also the first report of the presence of 2,3-dihydroxypropionyl-selenolanthionine (m/z 345) in rice. Because these crops can be an important source of selenium in animal and human nutrition, the understanding of the origin and the fate of these species during metabolic processes will be of great interest.

  11. 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

  12. Attenuation of corneal neovascularization by topical low-molecular-weight heparin-taurocholate 7 without bleeding complication

    PubMed Central

    Kim, Jae Yong; Kim, Soo Yeon; Cheon, Mi Hyun; Kim, Eun-Soon; Song, In Seok; Kim, Myoung Joon; Tchah, Hungwon

    2016-01-01

    AIM To investigate the antiangiogenic effects and safety of topically administered low-molecular-weight heparin-taurocholate 7 (LHT7) on corneal neovascularization (CoNV). METHODS Twenty-four Sprague-Dawley rats were randomly distributed into four groups of six rats each. The central corneas were cauterized using a silver/potassium nitrate solution. From 2d after cauterization, 12.5 mg/mL (low LHT7 group) or 25 mg/mL (high LHT7 group) LHT7 was topically administered three times daily; 12.5 mg/mL bevacizumab was topically administered as positive control (bevacizumab) group, with normal saline (NS) administered as negative control (NS group). The corneas were digitally photographed to calculate the CoNV percentage from the neovascularized corneal area at 1 and 2wk. RESULTS The 4 study groups did not have different CoNV percentages at 1wk after injury (P>0.05). However, the low LHT, high LHT, and bevacizumab groups had significantly lower CoNV percentages than the NS group at 2wk (all P<0.05). No significant differences in CoNV percentage were found among the low LHT, high LHT, and bevacizumab groups (all P>0.05). All groups except the NS group had lower CoNV percentages at 2wk post-injury than the levels observed at 1wk (all P<0.05). CONCLUSION Topically-administered LHT7 inhibited CoNV without complication after chemical cauterization in the rat. PMID:27672587

  13. An evaluation of the capability of a biolayer interferometry biosensor to detect low-molecular-weight food contaminants.

    PubMed

    McGrath, Terry F; Campbell, Katrina; Fodey, Terry L; O'Kennedy, Richard; Elliott, Christopher T

    2013-03-01

    The safety of our food is an essential requirement of society. One well-recognised threat is that of chemical contamination of our food, where low-molecular-weight compounds such as biotoxins, drug residues and pesticides are present. Low-cost, rapid screening procedures are sought to discriminate the suspect samples from the population, thus selecting only these to be forwarded for confirmatory analysis. Many biosensor assays have been developed as screening tools in food contaminant analysis, but these tend to be electrochemical, fluorescence or surface plasmon resonance based. An alternative approach is the use of biolayer interferometry, which has become established in drug discovery and life science studies but is only now emerging as a potential tool in the analysis of food contaminants. A biolayer interferometry biosensor was assessed using domoic acid as a model compound. Instrument repeatability was tested by simultaneously producing six calibration curves showing replicate repeatability (n = 2) ranging from 0.1 to 6.5 % CV with individual concentration measurements (n = 12) ranging from 4.3 to 9.3 % CV, giving a calibration curve midpoint of 7.5 ng/ml (2.3 % CV (n = 6)). Reproducibility was assessed by producing three calibration curves on different days, giving a midpoint of 7.5 ng/ml (3.4 %CV (n = 3)). It was further shown, using assay development techniques, that the calibration curve midpoint could be adjusted from 10.4 to 1.9 ng/ml by varying assay parameters before the simultaneous construction of three calibration curves in matrix and buffer. Sensitivity of the assay compared favourably with previously published biosensor data for domoic acid. PMID:23338757

  14. Natural Compounds Interacting with Nicotinic Acetylcholine Receptors: From Low-Molecular Weight Ones to Peptides and Proteins

    PubMed Central

    Kudryavtsev, Denis; Shelukhina, Irina; Vulfius, Catherine; Makarieva, Tatyana; Stonik, Valentin; Zhmak, Maxim; Ivanov, Igor; Kasheverov, Igor; Utkin, Yuri; Tsetlin, Victor

    2015-01-01

    Nicotinic acetylcholine receptors (nAChRs) fulfill a variety of functions making identification and analysis of nAChR subtypes a challenging task. Traditional instruments for nAChR research are d-tubocurarine, snake venom protein α-bungarotoxin (α-Bgt), and α-conotoxins, neurotoxic peptides from Conus snails. Various new compounds of different structural classes also interacting with nAChRs have been recently identified. Among the low-molecular weight compounds are alkaloids pibocin, varacin and makaluvamines C and G. 6-Bromohypaphorine from the mollusk Hermissenda crassicornis does not bind to Torpedo nAChR but behaves as an agonist on human α7 nAChR. To get more selective α-conotoxins, computer modeling of their complexes with acetylcholine-binding proteins and distinct nAChRs was used. Several novel three-finger neurotoxins targeting nAChRs were described and α-Bgt inhibition of GABA-A receptors was discovered. Information on the mechanisms of nAChR interactions with the three-finger proteins of the Ly6 family was found. Snake venom phospholipases A2 were recently found to inhibit different nAChR subtypes. Blocking of nAChRs in Lymnaea stagnalis neurons was shown for venom C-type lectin-like proteins, appearing to be the largest molecules capable to interact with the receptor. A huge nAChR molecule sensible to conformational rearrangements accommodates diverse binding sites recognizable by structurally very different compounds. PMID:26008231

  15. An evaluation of the capability of a biolayer interferometry biosensor to detect low-molecular-weight food contaminants.

    PubMed

    McGrath, Terry F; Campbell, Katrina; Fodey, Terry L; O'Kennedy, Richard; Elliott, Christopher T

    2013-03-01

    The safety of our food is an essential requirement of society. One well-recognised threat is that of chemical contamination of our food, where low-molecular-weight compounds such as biotoxins, drug residues and pesticides are present. Low-cost, rapid screening procedures are sought to discriminate the suspect samples from the population, thus selecting only these to be forwarded for confirmatory analysis. Many biosensor assays have been developed as screening tools in food contaminant analysis, but these tend to be electrochemical, fluorescence or surface plasmon resonance based. An alternative approach is the use of biolayer interferometry, which has become established in drug discovery and life science studies but is only now emerging as a potential tool in the analysis of food contaminants. A biolayer interferometry biosensor was assessed using domoic acid as a model compound. Instrument repeatability was tested by simultaneously producing six calibration curves showing replicate repeatability (n = 2) ranging from 0.1 to 6.5 % CV with individual concentration measurements (n = 12) ranging from 4.3 to 9.3 % CV, giving a calibration curve midpoint of 7.5 ng/ml (2.3 % CV (n = 6)). Reproducibility was assessed by producing three calibration curves on different days, giving a midpoint of 7.5 ng/ml (3.4 %CV (n = 3)). It was further shown, using assay development techniques, that the calibration curve midpoint could be adjusted from 10.4 to 1.9 ng/ml by varying assay parameters before the simultaneous construction of three calibration curves in matrix and buffer. Sensitivity of the assay compared favourably with previously published biosensor data for domoic acid.

  16. Low molecular weight heparin seems to improve local capillary circulation and healing of chronic foot ulcers in diabetic patients.

    PubMed

    Jörneskog, G; Brismar, K; Fagrell, B

    1993-01-01

    Ten diabetic patients with peripheral arterial occlusive disease, peripheral polyneuropathy and chronic foot ulcers were given 2500 U low molecular weight heparin (Fragmin, Kabi-Pharmacia AB, Sweden) subcutaneously once a day during 8 weeks. The mean age was 63 (47-80) years and the mean duration of foot ulcers 8 (4-12) months. All patients had previously received conventional treatment during 12 weeks, without any noticeable improvement on ulcer healing. The ulcer area was measured, and the skin microcirculation of the forefoot and around the ulcers was investigated before, during and after treatment with Fragmin. The total skin microcirculation was measured by laser Doppler fluxmetry, the nutritional skin microcirculation by vital capillaroscopy and the macrocirculation by determination of the ankle/arm pressure ratio. The ulcer area decreased significantly in eight patients of which four healed the ulcers completely. Of the remaining two patients one deteriorated, whereas one showed a decrease of the ulcer area during treatment, but an increase when treatment was stopped. The macro- and total microcirculation were unchanged in all patients, whereas the nutritional capillary circulation improved in seven out of nine patients, concomitantly with clinical improvement. The biological zero value (a flow-independent part of the LD signal) was high in 4 patients before treatment, but decreased during treatment and remained low even after treatment with Fragmin.-The results indicate that Fragmin positively influences the healing process of chronic foot ulcers in diabetic patients, possibly by improving the capillary circulation in the ulcer margin, in spite of an unchanged arterial and total skin microcirculation of the region.

  17. Inhibitory effects of low molecular weight polyphenolics from Inonotus obliquus on human DNA topoisomerase activity and cancer cell proliferation.

    PubMed

    Kuriyama, Isoko; Nakajima, Yuki; Nishida, Hiroshi; Konishi, Tetsuya; Takeuchi, Toshifumi; Sugawara, Fumio; Yoshida, Hiromi; Mizushina, Yoshiyuki

    2013-08-01

    Low molecular weight (LMW) polyphenolics containing a polyhydroxylated benzyl moiety are abundant in medicinal plants. In the present study, we report on the activities of seven LMW polyphenolics isolated from Inonotus obliquus, a medicinal mushroom. The isolated compounds included caffeic acid (CA), 3,4-dihydroxybenzalacetone (DBL), gallic acid, syringic acid, protocatechuic acid, 3,4-dihydroxybenzaldehyde and 2,5-dihydroxyterephthalic acid. We analyzed their inhibitory effects on DNA polymerase (pol) and DNA topoisomerase (topo), and their effects on human cancer cell growth. All isolated compounds inhibited human topo II activity; the most potent were DBL and CA, which contain a catechol propanoid moiety. CA and DBL inhibited the activity of human topo I, whereas other compounds had no effect. No compound modulated the activities of 11 mammalian pol species or other DNA metabolic enzymes, including T7 RNA polymerase, mouse IMP dehydrogenase (type II), T4 polynucleotide kinase and bovine deoxyribonuclease I. CA and DBL markedly suppressed the proliferation of human colon HCT116 carcinoma cells with an LD50 of 70.0 and 49.4 µM, respectively, and halted the cell cycle in the G2/M phase. The suppressive effect of these compounds on cancer cell growth correlated with their ability to inhibit topo II. These results suggest that CA- and DBL-dependent decreases in cell proliferation are due to the inhibition of cellular topo II. The mechanism of action of these catechol propanoid compounds and the implication for their use as anticancer agents are discussed. PMID:23799608

  18. Identification and analysis of low molecular weight dissolved organic carbon in subglacial basal ice ecosystems by ion chromatography

    NASA Astrophysics Data System (ADS)

    Lawson, E. C.; Wadham, J. L.; Lis, G. P.; Tranter, M.; Pickard, A. E.; Stibal, M.; Dewsbury, P.; Fitzsimons, S.

    2015-08-01

    Glacial runoff is an important source of dissolved organic carbon (DOC) for downstream heterotrophic activity, despite the low overall DOC concentrations. This is because of the abundance of bioavailable, low molecular weight (LMW) DOC species. However, the provenance and character of LMW-DOC is not fully understood. We investigated the abundance and composition of DOC in subglacial environments via a molecular level DOC analysis of basal ice, which forms by water/sediment freeze-on to the glacier sole. Spectrofluorometry and a novel ion chromatographic method, which has been little utilised in glacial science for LMW-DOC determinations, were employed to identify and quantify the major LMW fractions (free amino acids, carbohydrates and carboxylic acids) in basal ice from four glaciers, each with a different basal debris type. Basal ice from Joyce Glacier (Antarctica) was unique in that 98 % of the LMW-DOC was derived from the extremely diverse FAA pool, comprising 14 FAAs. LMW-DOC concentrations in basal ice were dependent on the bioavailability of the overridden organic carbon (OC), which in turn, was influenced by the type of overridden material. Mean LMW-DOC concentrations in basal ice from Russell Glacier (Greenland), Finsterwalderbreen (Svalbard) and Engabreen (Norway) were low (0-417 nM C), attributed to the relatively refractory nature of the OC in the overridden paleosols and bedrock. In contrast, mean LMW-DOC concentrations were an order of magnitude higher (4430 nM C) in basal ice from Joyce Glacier, a reflection of the high bioavailability of the overridden lacustrine material (>17 % of the sediment OC comprised extractable carbohydrates, a proxy for bioavailable OC). We find that the overridden material may act as a direct (via abiotic leaching) and indirect (via microbial cycling) source of DOC to the subglacial environment and provides a range of LMW-DOC compounds that may stimulate microbial activity in wet sediments in current subglacial

  19. 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.

  20. Comparative studies on chitosan and polylactic-co-glycolic acid incorporated nanoparticles of low molecular weight heparin.

    PubMed

    Yang, Tianzhi; Nyiawung, Divine; Silber, Alexandra; Hao, Jiukuan; Lai, Leanne; Bai, Shuhua

    2012-12-01

    This study was performed to test the feasibility of chitosan and polylactic-co-glycolic acid (PLGA) incorporated nanoparticles as sustained-release carriers for the delivery of negatively charged low molecular weight heparin (LMWH). Fourier transform infrared (FTIR) spectrometry was used to evaluate the interactions between chitosan and LMWH. The shifts, intensity, and broadening of the characteristic peaks for the functional groups in the FTIR spectra indicated that strong interactions occur between the positively charged chitosans and the negatively charged LMWHs. Three types of LMWH nanoparticles (NP-1, NP-2, and NP-3) were prepared using chitosan with or without PLGA: NP-1 nanoparticles were formed by polyelectrolyte complexation after single mixing, NP-2 nanoparticles were prepared by polyelectrolyte complexation after single emulsion-diffusion-evaporation, and NP-3 nanoparticles were optimized by double emulsion-diffusion-evaporation. NP-3 nanoparticles of LMWH prepared by the emulsion-diffusion-evaporation method showed significant differences in particle morphology, size, zeta potential, and drug release profile compared to NP-1 nanoparticles formed by polyelectrolyte complexation. Another ionic complex of LMWH with chitosan-incorporated PLGA nanoparticles (NP-2) showed lower drug entrapment efficiency than that of NP-1 and NP-3. The drug release rate of NP-3 was slower than the release rates of NP-1 and NP-2, although particle morphology of NP-3 was similar to that of NP-2. Cell viability was not adversely affected when cells were treated with all three types of nanoparticles. The data presented in this study demonstrate that nanoparticles formulated with chitosan-PLGA could be a safe sustained-release carrier for the delivery of LMWH.

  1. Effects of low molecular weight sodium alginate on growth performance, immunity, and disease resistance of tilapia, Oreochromis niloticus.

    PubMed

    Van Doan, Hien; Tapingkae, Wanaporn; Moonmanee, Tossapol; Seepai, Apichart

    2016-08-01

    Present study was carried out to evaluate the effects of low molecular weight sodium alginate (LMWSA) as potential prebiotic source on growth performance, innate immunity and disease resistance of tilapia, Oreochromis niloticus. Three hundred twenty fish were divided into four treatments and fed following diets 0 (T1- Control), 10 (T2), 20 (T3) and 30 (T4) g kg(-1) LMWSA for period of 60 days. A Completely Randomized Design with four replications was applied. At the end of experiment, fish in each replication were weighed and specific growth rate (SGR) and feed conversion ratio (FCR) were calculated. Five randomly selected fish were used for innate immune response measurement. Another ten fish were randomly selected for challenge test against Streptococcus agalactiae for a period of 18 days. The lysozyme, complement, phagocytosis, and respiratory burst activities were detected after 60 days of feeding trial and after challenge test. The results indicated that fish fed diet 10 g kg(-1) LMWSA significantly improved SGR and FCR after 60 days of feeding trial. The lysozyme, phagocytosis, respiratory burst, and complement activities were significantly higher in fish fed LMWSA diets compared to control. Fish fed 10 g kg(-1) LMWSA had greatest values compared to fish fed 20 and 30 g kg(-1) LMWSA. The survival rate of O. niloticus was significantly improved in fish fed LMWSA diets after challenge with S. agalactiae for 18 days. However, no significant difference in survival rate was observed among LMWSA supplemented diets. It is indicated that fish fed 10, 20 and 30 g kg(-1) LMWSA diets can stimulate growth performance, innate immunity and disease resistance in tilapia against S. agalactiae.

  2. [Low molecular weight carboxylic acids in precipitation during the rainy season in the rural area of Anshun, West Guizhou Province].

    PubMed

    Zhang, Yan-Lin; Lee, Xin-Qing; Huang, Dai-Kuan; Huang, Rong-Sheng; Jiang, Wei

    2009-03-15

    40 rainwater samples were collected at Anshun from June 2007 to October 2007 and analysed in terms of pH values, electrical conductivity, major inorganic anions and soluble low molecular weight carboxylic acids. The results showed that pH of individual precipitation events ranged from 3.57-7.09 and the volume weight mean pH value was 4.57. The most abundant carboxylic acids were acetic (volume weight mean concentration 6.75 micromol x L(-1)) and formic (4.61 micromol x L(-1)) followed by oxalic (2.05 micromol x L(-1)). The concentration levels for these three species during summer especially June and July were comparatively high; it implied that organic acids in Anshun may came primarily from emissions from growing vegetations or products of the photochemical reactions of unsaturated hydrocarbons. Carboxylic acids were estimated to account for 32.2% to the free acidity in precipitation. The contribution was higher than in Guiyang rainwater, which indicated contamination by industry in Guiyang was more than in Anshun. The remarkable correlation(p = 0.01) between formic acid and acetic acid suggest that they have similar sources or similar intensity but different sources. And the remarkable correlation (p = 0.01) between and formic acid and oxalic acid showed that the precursors of oxalic acid and formic acid had similar sources. During this period, the overall wet deposition of carboxylic acids were 2.10 mmol/m2. And it appeared mainly in the summer, during which both concentration and contribution to free acidity were also relatively high. Consequently, it was necessary to control emission of organic acids in the summer to reduce frequence of acid rain in Anshun.

  3. Voltammetric extraction of heparin and low-molecular-weight heparin across 1,2-dichloroethane/water interfaces.

    PubMed

    Jing, Ping; Kim, Yushin; Amemiya, Shigeru

    2009-12-01

    Heparin and low-molecular-weight heparin are voltammetrically extracted across 1,2-dichloroethane/water interfaces for the detection of these highly sulfated polysaccharides widely used as anticoagulants/antithrombotics in many medical procedures. A new heparin ionophore, 1-[4-(dioctadecylcarbamoyl)butyl]guanidinium, is the first to enable the voltammetric extraction of various polyanionic heparins with average molecular weights of up to approximately 20 kDa including those in commercial preparations (i.e., Arixtra (1.5 kDa), Lovenox (4.5 kDa), and unfractionated heparin (15 kDa), as well as chromatographically fractionated heparins (7, 9, 15, and 20 kDa)). Facilitated Arixtra extraction is fully and quantitatively characterized by micropipet voltammetry to propose that cooperative effects from strong heparin-binding capability and high lipophilicity of this ionophore are required for the formation of an electrically neutral and highly lipophilic complex of a heparin molecule with multiple ionophore molecules to be extracted into the nonpolar organic phase. At the same time, the participation of multiple ionophore molecules in interfacial complexation with a heparin molecule slows down its extraction across the interface. This kinetic limitation is enhanced by fast mass transfer at a micropipet-supported interface to compromise thermodynamically favorable selectivity for heparin and an important contaminant, oversulfated chondroitin sulfate, thereby requiring a macroscopic interface for sensing applications. Another highly lipophilic guanidinium ionophore, N,N-dioctadecylguanidinium, cannot completely extract even Arixtra, which indicates the importance of elaborate ionophore design for heparin extraction.

  4. α, ω-Cholesterol-functionalized low molecular weight polyethylene glycol as a novel modifier of cationic liposomes for gene delivery.

    PubMed

    Ma, Cui-Cui; He, Zhi-Yao; Xia, Shan; Ren, Ke; Hui, Li-Wei; Qin, Han-Xiao; Tang, Ming-Hai; Zeng, Jun; Song, Xiang-Rong

    2014-11-06

    Here, three novel cholesterol (Ch)/low molecular weight polyethylene glycol (PEG) conjugates, termed α, ω-cholesterol-functionalized PEG (Ch2-PEGn), were successfully synthesized using three kinds of PEG with different average molecular weight (PEG600, PEG1000 and PEG2000). The purpose of the study was to investigate the potential application of novel cationic liposomes (Ch2-PEGn-CLs) containing Ch2-PEGn in gene delivery. The introduction of Ch2-PEGn affected both the particle size and zeta potential of cationic liposomes. Ch2-PEG2000 effectively compressed liposomal particles and Ch2-PEG2000-CLs were of the smallest size. Ch2-PEG1000 and Ch2-PEG2000 significantly decreased zeta potentials of Ch2-PEGn-CLs, while Ch2-PEG600 did not alter the zeta potential due to the short PEG chain. Moreover, the in vitro gene transfection efficiencies mediated by different Ch2-PEGn-CLs also differed, in which Ch2-PEG600-CLs achieved the strongest GFP expression than Ch2-PEG1000-CLs and Ch2-PEG2000-CLs in SKOV-3 cells. The gene delivery efficacy of Ch2-PEGn-CLs was further examined by addition of a targeting moiety (folate ligand) in both folate-receptor (FR) overexpressing SKOV-3 cells and A549 cells with low expression of FR. For Ch2-PEG1000-CLs and Ch2-PEG2000-CLs, higher molar ratios of folate ligand resulted in enhanced transfection efficacies, but Ch2-PEG600-CLs had no similar in contrast. Additionally, MTT assay proved the reduced cytotoxicities of cationic liposomes after modification by Ch2-PEGn. These findings provide important insights into the effects of Ch2-PEGn on cationic liposomes for delivering genes, which would be beneficial for the development of Ch2-PEGn-CLs-based gene delivery system.

  5. Isolation and characterization of cotiaractivase, a novel low molecular weight prothrombin activator from the venom of Bothrops cotiara.

    PubMed

    Senis, Yotis A; Kim, Paul Y; Fuller, Gemma L J; García, Angel; Prabhakar, Sripadi; Wilkinson, Mark C; Brittan, Helen; Zitzmann, Nicole; Wait, Robin; Warrell, David A; Watson, Steve P; Kamiguti, Aura S; Theakston, R David G; Nesheim, Michael E; Laing, Gavin D

    2006-05-01

    In this study, we isolated a novel prothrombin activator from the venom of Bothrops cotiara, a Brazilian lance-headed pit viper (Cotiara, Jararaca preta, Biocotiara), which we have designated "cotiaractivase" (prefix: cotiar- from B. cotiara; suffix: -activase, from prothrombin activating activity). Cotiaractivase was purified using a phenyl-Superose hydrophobic interaction column followed by a Mono-Q anion exchange column. It is a single-chain polypeptide with a molecular weight of 22,931 Da as measured by mass spectroscopy. Cotiaractivase generated active alpha-thrombin from purified human prothrombin in a Ca2+-dependent manner as assessed by S2238 chromogenic substrate assay and SDS-PAGE. Cotiaractivase cleaved prothrombin at positions Arg271-Thr272 and Arg320-Ile321, which are also cleaved by factor Xa. However, the rate of thrombin generation by cotiaractivase was approximately 60-fold less than factor Xa alone and 17 x 10(6)-fold less than the prothrombinase complex. The enzymatic activity of cotiaractivase was inhibited by the chelating agent EDTA, whereas the serine protease inhibitor PMSF had no effect on its activity, suggesting that it is a metalloproteinase. Interestingly, S2238 inhibited cotiaractivase activity non-competitively, suggesting that this toxin contains an exosite that allows it to bind prothrombin independently of its active site. Tandem mass spectrometry and N-terminal sequencing of purified cotiaractivase identified peptides that were identical to regions of the cysteine-rich and disintegrin-like domains of known snake venom metalloproteinases. Cotiaractivase is a unique low molecular weight snake venom prothrombin activator that likely belongs to the metalloproteinase family of proteins. PMID:16647309

  6. Natural compounds interacting with nicotinic acetylcholine receptors: from low-molecular weight ones to peptides and proteins.

    PubMed

    Kudryavtsev, Denis; Shelukhina, Irina; Vulfius, Catherine; Makarieva, Tatyana; Stonik, Valentin; Zhmak, Maxim; Ivanov, Igor; Kasheverov, Igor; Utkin, Yuri; Tsetlin, Victor

    2015-05-01

    Nicotinic acetylcholine receptors (nAChRs) fulfill a variety of functions making identification and analysis of nAChR subtypes a challenging task. Traditional instruments for nAChR research are d-tubocurarine, snake venom protein α-bungarotoxin (α-Bgt), and α-conotoxins, neurotoxic peptides from Conus snails. Various new compounds of different structural classes also interacting with nAChRs have been recently identified. Among the low-molecular weight compounds are alkaloids pibocin, varacin and makaluvamines C and G. 6-Bromohypaphorine from the mollusk Hermissenda crassicornis does not bind to Torpedo nAChR but behaves as an agonist on human α7 nAChR. To get more selective α-conotoxins, computer modeling of their complexes with acetylcholine-binding proteins and distinct nAChRs was used. Several novel three-finger neurotoxins targeting nAChRs were described and α-Bgt inhibition of GABA-A receptors was discovered. Information on the mechanisms of nAChR interactions with the three-finger proteins of the Ly6 family was found. Snake venom phospholipases A2 were recently found to inhibit different nAChR subtypes. Blocking of nAChRs in Lymnaea stagnalis neurons was shown for venom C-type lectin-like proteins, appearing to be the largest molecules capable to interact with the receptor. A huge nAChR molecule sensible to conformational rearrangements accommodates diverse binding sites recognizable by structurally very different compounds. PMID:26008231

  7. Opposing Effects of Low Molecular Weight Heparins on the Release of Inflammatory Cytokines from Peripheral Blood Mononuclear Cells of Asthmatics

    PubMed Central

    Shastri, Madhur D.; Stewart, Niall; Eapen, Mathew; Peterson, Gregory M.; Zaidi, Syed Tabish R.; Gueven, Nuri; Sohal, Sukhwinder Singh; Patel, Rahul P.

    2015-01-01

    Background T-cell-mediated inflammatory cytokines, such as interleukin (IL)-4, IL-5, IL-13 and tumor necrosis factor-alpha (TNF-α), play an important role in the initiation and progression of inflammatory airways diseases. Low-molecular-weight heparins (LMWHs), widely used anticoagulants, possess anti-inflammatory properties making them potential treatment options for inflammatory diseases, including asthma. In the current study, we investigated the modulating effects of two LMWHs (enoxaparin and dalteparin) on the release of cytokines from stimulated peripheral blood mononuclear cells (PBMCs) of asthmatic subjects to identify the specific components responsible for the effects. Methods PBMCs from asthmatic subjects (consist of ~75% of T-cells) were isolated from blood taken from ten asthmatic subjects. The PBMCs were pre-treated in the presence or absence of different concentrations of LMWHs, and were then stimulated by phytohaemagglutinin for the release of IL-4, IL-5, IL-13 and TNF-α. LMWHs were completely or selectively desulfated and their anticoagulant effect, as well as the ability to modulate cytokine release, was determined. LMWHs were chromatographically fractionated and each fraction was tested for molecular weight determination along with an assessment of anticoagulant potency and effect on cytokine release. Results Enoxaparin inhibited cytokine release by more than 48%, whereas dalteparin increased their release by more than 25%. The observed anti-inflammatory effects of enoxaparin were independent of their anticoagulant activities. Smaller fractions, in particular dp4 (four saccharide units), were responsible for the inhibitory effect of enoxaparin. Whereas, the larger fractions, in particular dp22 (twenty two saccharide units), were associated with the stimulatory effect of dalteparin. Conclusion Enoxaparin and dalteparin demonstrated opposing effects on inflammatory markers. These observed effects could be due to the presence of structurally

  8. 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

  9. 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.

  10. Low Molecular Weight Hyaluronan-Pulsed Human Dendritic Cells Showed Increased Migration Capacity and Induced Resistance to Tumor Chemoattraction

    PubMed Central

    Rizzo, Manglio; Bayo, Juan; Piccioni, Flavia; Malvicini, Mariana; Fiore, Esteban; Peixoto, Estanislao; García, Mariana G.; Aquino, Jorge B.; Gonzalez Campaña, Ariel; Podestá, Gustavo; Terres, Marcelo; Andriani, Oscar; Alaniz, Laura; Mazzolini, Guillermo

    2014-01-01

    We have shown that ex vivo pre-conditioning of bone marrow-derived dendritic cells (DC) with low molecular weight hyaluronan (LMW HA) induces antitumor immunity against colorectal carcinoma (CRC) in mice. In the present study we investigated the effects of LMW HA priming on human-tumor-pulsed monocytes-derived dendritic cells (DC/TL) obtained from healthy donors and patients with CRC. LMW HA treatment resulted in an improved maturation state of DC/TL and an enhanced mixed leucocyte reaction activity in vivo. Importantly, pre-conditioning of DC/TL with LMW HA increased their ability to migrate and reduced their attraction to human tumor derived supernatants. These effects were associated with increased CCR7 expression levels in DC. Indeed, a significant increase in migratory response toward CCL21 was observed in LMW HA primed tumor-pulsed monocyte-derived dendritic cells (DC/TL/LMW HA) when compared to LWM HA untreated cells (DC/TL). Moreover, LMW HA priming modulated other mechanisms implicated in DC migration toward lymph nodes such as the metalloproteinase activity. Furthermore, it also resulted in a significant reduction in DC migratory capacity toward tumor supernatant and IL8 in vitro. Consistently, LMW HA dramatically enhanced in vivo DC recruitment to tumor-regional lymph nodes and reduced DC migration toward tumor tissue. This study shows that LMW HA –a poorly immunogenic molecule- represents a promising candidate to improve human DC maturation protocols in the context of DC-based vaccines development, due to its ability to enhance their immunogenic properties as well as their migratory capacity toward lymph nodes instead of tumors. PMID:25238610

  11. LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

    NASA Astrophysics Data System (ADS)

    Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

    2010-06-01

    This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29-83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.

  12. A review of environmental characteristics and effects of low-molecular weight organic acids in the surface ecosystem.

    PubMed

    Xiao, Min; Wu, Fengchang

    2014-05-01

    Low molecular weight organic acids (LMWOAs) are prevalent on the earth's surface. They are vital intermediate products during metabolic pathways of organic matter and participate in the tricarboxylic acid cycle during life activities. Photochemical reactions are pivotal for LMWOAs' origination and play a large role in determining their diversity and their ultimate fate. Within the long time that organic matter is preserved in sediments, it can be decomposed and converted to release organic and inorganic pollutants as well as C, N, and P nutrients, which are of potential ecological risk in causing secondary pollution to lake water. The sediment pool is a comprehensive and complex compartment closely associated with overlying water by various biochemical processes, during which LMWOAs play critical roles to transport and transform elements. This article elucidates geochemical behaviors of LMWOAs in the surface environment in details, taking natural water, soil, and aerosol as examples, focusing on reviewing research developments on sources and characteristics, migration and mineralization of LMWOAs and relevant environmental effects. Simultaneously, this review article depicts the categories and contents of LMWOAs or their contribution to DOC in environmental media, and evaluates their importance during organic matter early diagenesis. Through concluding and discussing the conversion mechanisms and influencing factors, the next research orientations on LMWOAs in lake ecosystems are determined, mainly concerning relationships with hydrochemical parameters and microorganisms, and interactions with pollutants. This will enrich the knowledge on organic matter degradation and related environmental effects, and help reconstruct a theoretical framework for organic compound succession and influencing factors, providing basic data for lake eutrophication and ecological risk assessment, conducive to better control over water pollution and proper management of water quality.

  13. Do soil Fe transformation and secretion of low-molecular-weight organic acids affect the availability of Cd to rice?

    PubMed

    Chen, Xue; Yang, Yazhou; Liu, Danqing; Zhang, Chunhua; Ge, Ying

    2015-12-01

    The bioavailability of cadmium (Cd) to rice may be complicated by chemical and biological factors in the rhizosphere. The aim of this work is to investigate how soil iron (Fe) redox transformations and low-molecular-weight organic acid (LMWOA) exudation from root affect Cd accumulation in rice. Two soils (a paddy soil and a saline soil) with different physicochemical properties were used in this study. Soil redox conditions were changed by flooding and addition of organic matter (OM). Two days after the soil treatments, rice seedlings were transplanted in a vermiculite-soil system and grown for 10 days. We measured pH and Eh, LMWOA, Fe and Cd contents in rice, and their fractions in the soils and vermiculite. Cadmium accumulation in rice declined in both soils upon the flooding and OM treatment. Iron dissolution in the paddy soil and its deposition in the rhizosphere significantly increased upon the OM addition, but the concentration of Fe plaque on the rice root significantly declined. Conversely, although Fe transformed into less active fractions in the saline soil, Fe accumulation on the surface and in the tissue of root was considerably enhanced. The secretion of LMWOA was remarkably induced when the OM was amended in the saline soil, but the same effect was not observed in the paddy soil. Reduction of Cd uptake by rice could be attributed to different factors in the two soils. For the paddy soil, the lowered Cd bioavailability was likely due to the competition of Fe and Cd for the binding sites on the vermiculite surface. For the saline soil, however, rice responded to the low Fe mobility through more LMWOA exudation and Fe plaque formation, and their increases could explain the decrease of rice Cd.

  14. 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.

  15. Effects of cadmium amendments on low-molecular-weight organic acid exudates in rhizosphere soils of tobacco and sunflower.

    PubMed

    Chiang, Po-Neng; Wang, Ming Kuang; Chiu, Chih Yu; Chou, Shu-Yen

    2006-10-01

    To recognize physiological response of plants to cadmium (Cd) toxicity in rhizosphere of plants, the pot experiments were employed to investigate how low-molecular-weight organic acids (LMWOAs) were exudated from tobacco and sunflower roots of Cd-amended soils. The aims of this study were to assess the effect of LMWOAs on uptake of Cd by tobacco and sunflower under pot experiments, thus comparing the ability of tobacco and sunflower for phytoremediation. Surface soils (0-20 cm) were collected from Taichung Experiment Station (TC) (silty loam). Cadmium chloride (CdCl(2)) was amended into TC soil, giving Cd concentrations of 1, 5, 10 mg kg(-1) soil. Soils with different concentrations of Cd were put into 12 cm (i.d.) pots for incubation, and then 2-week-old tobacco and sunflower seedlings were transplanted into the pots. Tobacco and sunflower were grown in greenhouse for 50 days, respectively. The rhizosphere and bulk soils, and fresh plant tissues were collected after harvest. The Cd concentrations in the plant and transfer factor values in the sunflower were higher than that in the tobacco. No LMWOAs were detected by gas chromatograph in bulk soils, and low amounts of LMWOAs were found in uncontaminated rhizosphere soils. Acetic, lactic, glycolic, malic, maleic, and succinic acids were found in the tobacco and sunflower rhizosphere soils. Concentrations of LMWOAs increased with increasing amendment of Cd concentrations in tobacco and sunflower rhizosphere soils. Correlation coefficient (r) of concentrations of Cd amendment versus LMWOAs exudates of tobacco and sunflower were 0.85 and 0.98, respectively. These results suggest that the different levels of LMWOAs present in the rhizosphere soil play an important role in the solubilization of Cd that bound with soil particle into soil solution and then uptake by plants.

  16. Attenuation of corneal neovascularization by topical low-molecular-weight heparin-taurocholate 7 without bleeding complication

    PubMed Central

    Kim, Jae Yong; Kim, Soo Yeon; Cheon, Mi Hyun; Kim, Eun-Soon; Song, In Seok; Kim, Myoung Joon; Tchah, Hungwon

    2016-01-01

    AIM To investigate the antiangiogenic effects and safety of topically administered low-molecular-weight heparin-taurocholate 7 (LHT7) on corneal neovascularization (CoNV). METHODS Twenty-four Sprague-Dawley rats were randomly distributed into four groups of six rats each. The central corneas were cauterized using a silver/potassium nitrate solution. From 2d after cauterization, 12.5 mg/mL (low LHT7 group) or 25 mg/mL (high LHT7 group) LHT7 was topically administered three times daily; 12.5 mg/mL bevacizumab was topically administered as positive control (bevacizumab) group, with normal saline (NS) administered as negative control (NS group). The corneas were digitally photographed to calculate the CoNV percentage from the neovascularized corneal area at 1 and 2wk. RESULTS The 4 study groups did not have different CoNV percentages at 1wk after injury (P>0.05). However, the low LHT, high LHT, and bevacizumab groups had significantly lower CoNV percentages than the NS group at 2wk (all P<0.05). No significant differences in CoNV percentage were found among the low LHT, high LHT, and bevacizumab groups (all P>0.05). All groups except the NS group had lower CoNV percentages at 2wk post-injury than the levels observed at 1wk (all P<0.05). CONCLUSION Topically-administered LHT7 inhibited CoNV without complication after chemical cauterization in the rat.

  17. Effects of low molecular weight sodium alginate on growth performance, immunity, and disease resistance of tilapia, Oreochromis niloticus.

    PubMed

    Van Doan, Hien; Tapingkae, Wanaporn; Moonmanee, Tossapol; Seepai, Apichart

    2016-08-01

    Present study was carried out to evaluate the effects of low molecular weight sodium alginate (LMWSA) as potential prebiotic source on growth performance, innate immunity and disease resistance of tilapia, Oreochromis niloticus. Three hundred twenty fish were divided into four treatments and fed following diets 0 (T1- Control), 10 (T2), 20 (T3) and 30 (T4) g kg(-1) LMWSA for period of 60 days. A Completely Randomized Design with four replications was applied. At the end of experiment, fish in each replication were weighed and specific growth rate (SGR) and feed conversion ratio (FCR) were calculated. Five randomly selected fish were used for innate immune response measurement. Another ten fish were randomly selected for challenge test against Streptococcus agalactiae for a period of 18 days. The lysozyme, complement, phagocytosis, and respiratory burst activities were detected after 60 days of feeding trial and after challenge test. The results indicated that fish fed diet 10 g kg(-1) LMWSA significantly improved SGR and FCR after 60 days of feeding trial. The lysozyme, phagocytosis, respiratory burst, and complement activities were significantly higher in fish fed LMWSA diets compared to control. Fish fed 10 g kg(-1) LMWSA had greatest values compared to fish fed 20 and 30 g kg(-1) LMWSA. The survival rate of O. niloticus was significantly improved in fish fed LMWSA diets after challenge with S. agalactiae for 18 days. However, no significant difference in survival rate was observed among LMWSA supplemented diets. It is indicated that fish fed 10, 20 and 30 g kg(-1) LMWSA diets can stimulate growth performance, innate immunity and disease resistance in tilapia against S. agalactiae. PMID:27238426

  18. Effects of proteins on absorption by the rat of iron from polymeric and low-molecular-weight iron species

    SciTech Connect

    Berner, L.; Miller, D.

    1986-03-05

    To examine effects of proteins on Fe absorption from polymeric ferric hydroxides (polys) or low-molecular-weight complexes (LMW Fe), 2 studies were conducted. First, anemic rats were given /sup 59/Fe-labeled polys or LMW Fe in the presence and absence of pepsin-digested soy protein isolate, casein, and BSA. The doses were introduced into ligated duodenal segments for 1 hr. Uptake into the carcass of /sup 59/Fe from polys was doubled in the presence of BSA (7.8 vs 16.1%, p < .05) while casein and soy had no effect (5.5 and 6.5%). Absorption of /sup 59/Fe from LMW Fe was 7X greater than from polys; BSA and casein had no effect but soy depressed Fe uptake by almost 50% (57.4 vs 35.5%, p < .05). The second experiment repeated the first except that the proteins were not pepsin-digested and the doses were given by gastric intubation. All Fe, whether from polys or LMW Fe, was highly available (although in vitro digestions reveal that polys are not depolymerized to a large degree under simulated stomach conditions). Soy depressed Fe uptake from both sources (92.9 vs. 81.6%, LMW Fe and 85.4 vs 73.7%, polys) while casein and BSA had no effect. These results show: (1) BSA can depolymerize polys in the rat duodenum, thus enhancing absorption; (2) soy isolate generally depressed Fe uptake; and (3) the rat stomach appears to have an exceptional capacity for equalizing Fe sources.

  19. Do soil Fe transformation and secretion of low-molecular-weight organic acids affect the availability of Cd to rice?

    PubMed

    Chen, Xue; Yang, Yazhou; Liu, Danqing; Zhang, Chunhua; Ge, Ying

    2015-12-01

    The bioavailability of cadmium (Cd) to rice may be complicated by chemical and biological factors in the rhizosphere. The aim of this work is to investigate how soil iron (Fe) redox transformations and low-molecular-weight organic acid (LMWOA) exudation from root affect Cd accumulation in rice. Two soils (a paddy soil and a saline soil) with different physicochemical properties were used in this study. Soil redox conditions were changed by flooding and addition of organic matter (OM). Two days after the soil treatments, rice seedlings were transplanted in a vermiculite-soil system and grown for 10 days. We measured pH and Eh, LMWOA, Fe and Cd contents in rice, and their fractions in the soils and vermiculite. Cadmium accumulation in rice declined in both soils upon the flooding and OM treatment. Iron dissolution in the paddy soil and its deposition in the rhizosphere significantly increased upon the OM addition, but the concentration of Fe plaque on the rice root significantly declined. Conversely, although Fe transformed into less active fractions in the saline soil, Fe accumulation on the surface and in the tissue of root was considerably enhanced. The secretion of LMWOA was remarkably induced when the OM was amended in the saline soil, but the same effect was not observed in the paddy soil. Reduction of Cd uptake by rice could be attributed to different factors in the two soils. For the paddy soil, the lowered Cd bioavailability was likely due to the competition of Fe and Cd for the binding sites on the vermiculite surface. For the saline soil, however, rice responded to the low Fe mobility through more LMWOA exudation and Fe plaque formation, and their increases could explain the decrease of rice Cd. PMID:26260840

  20. Arsenic tolerance in mesquite (Prosopis sp.): low molecular weight thiols synthesis and glutathione activity in response to arsenic.

    PubMed

    Mokgalaka-Matlala, Ntebogeng S; Flores-Tavizón, Edith; Castillo-Michel, Hiram; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2009-09-01

    The effects of arsenic stress on the production of low molecular weight thiols (LMWT), glutathione S-transferase activity (GST) and sulfur metabolism of mesquite plant (Prosopis sp.) were examined in hydroponic culture at different arsenic [As(III) and (V)] concentrations. The production of LMWT was dependent on As speciation and concentration in the growth medium. The roots of As(III) treated plants produced significantly higher LMWT levels than As(V) treated roots at the same concentration of As applied. In leaves, the thiols content increased with increasing As(III) and (V) concentrations in the medium. Hypersensitivity of the plant to high As concentrations was observed by a significant decrease of LMWT produced in the roots at 50 mg/L treatment in both As(III) and (V) treatments. Sulfur was translocated from roots and accumulated mainly in the shoots. In response to As-induced phytotoxicity, the plants slightly increased the sulfur content in the roots at the highest As treatment. Compared with As(V)-treated plants, As(III)-treated roots and leaves showed significantly higher GST activity. The roots of both As(III) and (V) treated plants showed an initial increase in GST at low As concentration (5 mg/L), followed by significant inhibition up to 50 mg/L. The leaves had the highest GST activity, an indication of the ability of the plant to detoxify As in the leaves than in the roots. The correlation between LMWT content, S content and GST activity may be an indication these parameters may be used as biomarkers of As stress in mesquite.

  1. Cloning and expression of the Erwinia carotovora subsp. carotovora gene encoding the low-molecular-weight bacteriocin carocin S1.

    PubMed

    Chuang, Duen-yau; Chien, Yung-chei; Wu, Huang-Pin

    2007-01-01

    The purpose of this study was to clone the carocin S1 gene and express it in a non-carocin-producing strain of Erwinia carotovora. A mutant, TH22-10, which produced a high-molecular-weight bacteriocin but not a low-molecular-weight bacteriocin, was obtained by Tn5 insertional mutagenesis using H-rif-8-2 (a spontaneous rifampin-resistant mutant of Erwinia carotovora subsp. carotovora 89-H-4). Using thermal asymmetric interlaced PCR, the DNA sequence from the Tn5 insertion site and the DNA sequence of the contiguous 2,280-bp region were determined. Two complete open reading frames (ORF), designated ORF2 and ORF3, were identified within the sequence fragment. ORF2 and ORF3 were identified with the carocin S1 genes, caroS1K (ORF2) and caroS1I (ORF3), which, respectively, encode a killing protein (CaroS1K) and an immunity protein (CaroS1I). These genes were homologous to the pyocin S3 gene and the pyocin AP41 gene. Carocin S1 was expressed in E. carotovora subsp. carotovora Ea1068 and replicated in TH22-10 but could not be expressed in Escherichia coli (JM101) because a consensus sequence resembling an SOS box was absent. A putative sequence similar to the consensus sequence for the E. coli cyclic AMP receptor protein binding site (-312 bp) was found upstream of the start codon. Production of this bacteriocin was also induced by glucose and lactose. The homology search results indicated that the carocin S1 gene (between bp 1078 and bp 1704) was homologous to the pyocin S3 and pyocin AP41 genes in Pseudomonas aeruginosa. These genes encode proteins with nuclease activity (domain 4). This study found that carocin S1 also has nuclease activity.

  2. Phragmites australis response to Cu in terms of low molecular weight organic acids (LMWOAs) exudation: Influence of the physiological cycle

    NASA Astrophysics Data System (ADS)

    Rocha, A. Cristina S.; Almeida, C. Marisa R.; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

    2014-06-01

    Plant roots have the ability to produce and secrete substances, such as aliphatic low molecular weight organic acids (ALMWOAs), into the rhizosphere for several purposes, including in response to metal contamination. Despite this, little is yet known about the exudation of such substances from marsh plants roots in response to metal exposure. This work aimed at assessing the influence of the physiological cycle of marsh plants on the exudation of ALMWOAs in response to Cu contamination. In vitro experiments were carried out with Phragmites australis specimens, collected in different seasons. Plant roots were exposed to freshwater contaminated with two different Cu concentrations (67 μg/L and 6.9 mg/L), being the ALMWOAs released by the roots measured. Significant differences (both qualitative and quantitative) were observed during the Phragmites australis life cycle. At growing stage, Cu stimulated the exudation of oxalic and formic acids but no significant stimulation was observed for citric acid. At developing stage, exposure to Cu caused inhibition of oxalic acid exudation whereas citric acid liberation was stimulated but only in the media spiked with the lowest Cu concentration tested. At the decaying stage, no significant variation on oxalic acid was observed, whereas the citric and formic acids release increased as a consequence of the plant exposure to Cu. The physiological cycle of Phragmites australis, and probably also of other marsh plants, is therefore an important feature conditioning plants response to Cu contamination, in terms of ALMWOAs exudation. Hence this aspect should be considered when conducting studies on rhizodeposition involving marsh plants exposed to metals and in the event of using marsh plants for phytoremediation purposes in contaminated estuarine areas.

  3. Gas/particle partitioning of low-molecular-weight dicarboxylic acids at a suburban site in Saitama, Japan

    NASA Astrophysics Data System (ADS)

    Bao, Linfa; Matsumoto, Mariko; Kubota, Tsutomu; Sekiguchi, Kazuhiko; Wang, Qingyue; Sakamoto, Kazuhiko

    2012-02-01

    Low-molecular-weight dicarboxylic acids (diacids) exhibit semivolatile behavior in the atmosphere, but their partitioning between the gaseous and particulate phases is still unclear. An annular denuder-filter pack system with a cyclone PM 2.5 was employed to investigate the gaseous and particulate phase concentrations of diacids, with high collection efficiency of most target compounds. Saturated diacids, unsaturated diacids, ketocarboxylic acids, and dicarbonyls were determined in gaseous and particulate samples collected from a suburban site in Japan, during 2007 summer, 2008 late-winter and early-winter. The concentrations of gaseous and particulate diacids in early-winter were lower than those in summer, but higher than those in late-winter. Individual diacid in gaseous phase showed a relatively good correlation with ambient oxidants, but a low correlation with NO gas (a primary pollutant). Particulate fraction to the total amount ( FP) of individual acid was larger in winter than in summer, and also was larger at night than in the daytime. In the same sample, individual diacid and ketocarboxylic acid had higher particulate phase occurrence ( FP > 56% in summer), whereas unsaturated diacid had higher gaseous phase occurrence ( FP < 18% in summer). In summer, gas/particle partitioning of diacids varied diurnally; FP values of oxalic and glyoxylic acids increased from their lowest values in the morning to their highest values at night, exhibiting the similar diurnal variation of relative humidity in the atmosphere. The higher humidity at night may lead to the formation of droplets in which water-soluble gaseous phases can dissolve, thus promoting gas-to-particle conversion. These results suggest that gas/particle partitioning of diacids depends not only on the concentrations in the gaseous phase by photochemical oxidation, but also on the characteristics of the atmosphere (e.g., temperature, sunlight, and relative humidity) and the aerosols (e.g., acidity

  4. Fragment profiling of low molecular weight heparins using reversed phase ion pair liquid chromatography-electrospray mass spectrometry.

    PubMed

    Xu, Xiaohui; Li, Daoyuan; Chi, Lequan; Du, Xuzhao; Bai, Xue; Chi, Lianli

    2015-04-30

    Low molecular weight heparins (LMWHs) are linear and highly charged carbohydrate polymers prepared by chemical or enzymatic depolymerization of heparin. Compared to unfractionated heparin (UFH), LMWHs are prevalently used as clinical anticoagulant drugs due to their lower side effects and better bioavailability. The work presented herein provides a rapid and powerful fragment mapping method for structural characterization of LMWHs. The chain fragments of two types of LMWHs, enoxaparin and nadroparin, were generated by controlled enzymatic digestion with each of heparinase I (Hep I, Enzyme Commission (EC) # 4.2.2.7), heparinase II (Hep II, no EC # assigned) and heparinase III (Hep III, EC # 4.2.2.8). Reversed phase ion pair high performance liquid chromatography (RPIP-HPLC) coupled with electrospray ion trap time-of-flight mass spectrometry (ESI-IT-TOF-MS) was used to profile the oligosaccharide chains ranging from disaccharides to decasaccharides. A database containing all theoretical structural compositions was established to assist the mass spectra interpretation. The six digests derived by three enzymes from two types of LMWHs exhibited distinguishable fingerprinting patterns. And a total of 94 enoxaparin fragments and 109 nadroparin fragments were detected and identified. Besides the common LMWH oligosaccharides, many components containing characteristic LMWH structures such as saturated L-idopyranosuronic acid, 2,5-anhydro-D-mannitol, 1,6-anhydro-D-aminopyranose, as well as odd number oligosaccharides were also revealed. Quantitative comparison of major components derived from innovator and generic nadroparin products was presented. This approach to profile LMWHs' fragments offers a highly reproducible, high resolution and information-rich tool for evaluating the quality of this category of anticoagulant drugs or comparing structural similarities among samples from various sources.

  5. Identification of Antihypertensive Peptides Derived from Low Molecular Weight Casein Hydrolysates Generated during Fermentation by Bifidobacterium longum KACC 91563

    PubMed Central

    Ha, Go Eun; Chang, Oun Ki; Jo, Su-Mi; Han, Gi-Sung; Park, Beom-Young; Ham, Jun-Sang; Jeong, Seok-Geun

    2015-01-01

    Angiotensin-converting enzyme (ACE) inhibitory activity was evaluated for the low-molecular-weight fraction (<3 kDa) obtained from milk fermentation by Bifidobacterium longum KACC91563. The ACE inhibitory activity in this fraction was 62.3%. The peptides generated from the <3 kDa fraction were identified by liquid chromatography-electrospray ionization quantitative time-of-flight mass spectrometry analysis. Of the 28 peptides identified, 11 and 16 were identified as β-casein (CN) and αs1-CN, respectively. One peptide was identified as κ-CN. Three peptides, YQEPVLGPVRGPFPIIV, QEPVLGPVRGPFPIIV, and GPVRGPFPIIV, from β-CN corresponded to known antihypertensive peptides. We also found 15 peptides that were identified as potential antihypertensive peptides because they included a known antihypertensive peptide fragment. These peptides were as follows: RELEELNVPGEIVE (f1-14), YQEPVLGPVRGPFP (f193-206), EPVLGPVRGPFPIIV (f195-206), PVLGPVRGPFPIIV (f196-206), VLGPVRGPFPIIV (f197-206), and LGPVRGPFPIIV (f198-206) for β-CN; and APSFSDIPNPIGSENSEKTTMPLW (f176-199), SFSDIPNPIGSENSEKT- TMPLW (f178-199), FSDIPNPIGSENSEKTTMPLW (f179-199), SDIPNPIGSENSEKTTMPLW (f180-199), DIPNPIGSENSEKTTMPLW (f181-199), IPNPIGSENSEKTTMPLW (f182-199), PIGSENSEKTTMPLW (f185-199), IGSENSEKTTMPLW (f186-199), and SENSEKTTMPLW (f188-199) for αs1-CN. From these results, B. longum could be used as a starter culture in combination with other lactic acid bacteria in the dairy industry, and/or these peptides could be used in functional food manufacturing as additives for the development of a product with beneficial effects for human health. PMID:26877633

  6. Proton play in the formation of low molecular weight chitosan (LWCS) by hydrolyzing chitosan with a carbon based solid acid.

    PubMed

    Krishnan, R Akhil; Deshmukh, Pranjal; Agarwal, Siddharth; Purohit, Poorvi; Dhoble, Deepa; Waske, Prashant; Khandekar, Dileep; Jain, Ratnesh; Dandekar, Prajakta

    2016-10-20

    Low molecular weight chitosan (LWCS) constitute a special class of value added chemicals that are primarily obtained from crustacean shells, which are the main water pollutants from crabs and shrimp processing centers. Unlike chitin and chitosan, LWCS possess improved solubility in water and aqueous solutions, making them widely applicable in numerous fields ranging from drug delivery to waste water treatment. Among the methods employed for their production, chemical breakdown by strong liquid acids has yielded good success. However, this method is met with severe concerns arising from the harsh nature of liquid acids, which may corrode the reactors for commercial synthesis, and their limited reusability. The physical methods like ultrasound and microwave are energy intensive in nature, while the enzymatic methods are expensive and offers limited scope for reuse. We have attempted to overcome these problems by employing carbon based solid acid (CSA) for hydrolyzing chitosan to LWCS. CSA can be easily produced using activated carbon, a cost-effective and easily available raw material. Reactions were carried out between chitosan and CSA in a hydrothermal glass reactor and the products, separated by cold centrifugation, were purified and dried. The dried products were characterized for their molecular weight and solubility. Results indicated more than ten-fold decrease in the molecular weight of chitosan and the product exhibited water solubility. The CSA could be used upto four times, without regeneration, to give a consistent quality product. The aqueous solution of resulting LWCS exhibited a pH of 6.03±0.11, as against the acidic pH range of solutions of commercially available LWCS, indicating its suitability for biomedical applications. Our investigation facilitates a 'green approach' that may be employed for commercial production of value added chemicals from waste products of marine industry. PMID:27474584

  7. 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

  8. A novel method for determination of low molecular weight dicarboxylic acids in background atmospheric aerosol using ion chromatography.

    PubMed

    Tsai, Ying I; Hsieh, Li-Ying; Weng, Tzu-Hsiang; Ma, Yu-Chien; Kuo, Su-Ching

    2008-09-19

    This paper describes a novel gradient elution ion chromatographic method using a Dionex AS11 system for the determination of low molecular weight dicarboxylic acids (low-M(w) DCAs) in background atmospheric aerosol. Interference with the oxalic acid peak from sulfate in background PM(2.5) aerosol, 15.8 times the oxalic acid concentration, was remedied by removing sulfate using a barium cartridge, whilst interference with the malonic acid peak from carbonate was reduced by using a carbonate removal device. An alternative remedy to sulfate interference was use of an AS14 system using isocratic eluent, and this produced good resolution of oxalic acid from a high sulfate peak. In both the AS11 and the AS14 system, linear correlation coefficients were at all times >0.9990 with excellent linear range, the recoveries ranged from 92.8 to 106%, with relative standard deviation of 3.67-6.30%, whilst method detection limits (MDLs) ranged from 0.36microgL(-1) for malic acid to 3.87microgL(-1) for maleic acid. These data indicate that the analytical methods developed herein produce excellent separation efficiency and good determination of low-M(w) DCAs with satisfactory accuracy, recoveries, and MDLs. Samples left at room temperature (20 degrees C) for 300min in a simulation of the 'waiting time' involved in the proposed IC analysis decayed to between 86% (oxalic acid) and 39% (succinic and malonic acids) of their original concentration, whilst at 4 degrees C concentrations remained at 96-101% of original, indicating that maintaining samples at a low temperature prior to injection into the IC analyzer is vital for obtaining accurate results when analyzing low-M(w) DCAs. Oxalic acid was found to be the most prevalent low-M(w) DCA in background aerosol, comprising 57% of the total low-M(w) DCAs and 0.959% of the PM(2.5) aerosol mass, followed by succinic acid and malonic acid.

  9. A multi-tolerant low molecular weight mannanase from Bacillus sp. CSB39 and its compatibility as an industrial biocatalyst.

    PubMed

    Regmi, Sudip; G C, Pradeep; Choi, Yun Hee; Choi, Yoon Seok; Choi, Ji Eun; Cho, Seung Sik; Yoo, Jin Cheol

    2016-10-01

    Bacillus sp. CSB39, isolated from popular traditional Korean food (Kimchi), produced a low molecular weight, thermostable mannanase (MnCSB39); 571.14U/mL using locust bean gum galactomannan as a major substrate. It was purified to homogeneity using a simple and effective two-step purification strategy, Sepharose CL-6B and DEAE Sepharose Fast Flow, which resulted in 25.47% yield and 19.32-fold purity. The surfactant-, NaCl-, urea-, and protease-tolerant monomeric protein had a mass of ∼30kDa as analyzed by SDS-PAGE and galactomannan zymography. MnCSB39 was found to have optimal activity at pH 7.5 and temperature of 70°C. The enzyme showed ˃55% activity at 5.0-15% (w/v) NaCl, and ˃93% of the initial activity after incubation at 37°C for 60min. Trypsin and proteinase K had no effect on MnCBS39. The enzyme showed ˃80% activity in up to 3M urea. The N-terminal amino acid sequence, ALKGDGX, did not show identity with reported mannanases, which suggests the novelty of our enzyme. Activation energy for galactomannan hydrolysis was 26.85kJmol(-1) with a Kcat of 142.58×10(4)s(-1). MnCSB39 had Km and Vmax values of 0.082mg/mL and 1099±1.0Umg(-1), respectively. Thermodynamic parameters such as ΔH, ΔG, ΔS, Q10, ΔGE-S, and ΔGE-T supported the spontaneous formation of products and the high hydrolytic efficiency and feasibility of the enzymatic reaction, which strengthen its novelty. MnCSB39 activity was affected by metal ions, modulators, chelators, and detergents. Mannobiose was the principal end-product of hydrolysis. Bacillus subtilis CSB39 produced a maximum of 1524.44U mannanase from solid state fermentation of 1g wheat bran. MnCSB39 was simple to purify, was active at a wide pH and temperature range, multi-stress tolerant and catalyzes a thermodynamically possible reaction, characteristics that suggests its suitability for application as an industrial biocatalyst. PMID:27542747

  10. Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice.

    PubMed

    Chou, Yen-Jung; Kan, Wei-Chih; Chang, Chieh-Min; Peng, Yi-Jen; Wang, Hsien-Yi; Yu, Wen-Chun; Cheng, Yu-Hsuan; Jhang, Yu-Rou; Liu, Hsia-Wei; Chuu, Jiunn-Jye

    2016-01-01

    Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM). Inonotus obliquus (IO) is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs) have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ)-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP), from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD) plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10-100 kDa, LIOP (300 mg/kg) had progressively increased their sensitivity to glucose (less insulin tolerance), reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR) compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL) incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1), while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

  11. AKAP95 promotes cell cycle progression via interactions with cyclin E and low molecular weight cyclin E

    PubMed Central

    Kong, Xiang-Yu; Zhang, Deng-Cheng; Zhuang, Wen-Xin; Hua, Su-Hang; Dai, Yue; Yuan, Yang-Yang; Feng, Li-Li; Huang, Qian; Teng, Bo-Gang; Yu, Xiu-Yi; Liu, Wen-Zhi; Zhang, Yong-Xing

    2016-01-01

    AKAP95 in lung cancer tissues showed higher expression than in paracancerous tissues. AKAP95 can bind with cyclin D and cyclin E during G1/S cell cycle transition, but its molecular mechanisms remain unclear. To identify the mechanism of AKAP95 in cell cycle progression, we performed AKAP95 transfection and silencing in A549 cells, examined AKAP95, cyclin E1 and cyclin E2 expression, and the interactions of AKAP95 with cyclins E1 and E2. Results showed that over-expression of AKAP95 promoted cell growth and AKAP95 bound cyclin E1 and E2, low molecular weight cyclin E1 (LWM-E1) and LWM-E2. Additionally AKAP95 bound cyclin E1 and LMW-E2 in the nucleus during G1/S transition, bound LMW-E1 during G1, S and G2/M, and bound cyclin E2 mainly on the nuclear membrane during interphase. Cyclin E2 and LMW-E2 were also detected. AKAP95 over-expression increased cyclin E1 and LMW-E2 expression but decreased cyclin E2 levels. Unlike cyclin E1 and LMW-E2 that were nuclear located during the G1, S and G1/S phases, cyclin E2 and LMW-E1 were expressed in all cell cycle phases, with cyclin E2 present in the cytoplasm and nuclear membrane, with traces in the nucleus. LMW-E1 was present in both the cytoplasm and nucleus. The 20 kDa form of LMW-E1 showed only cytoplasmic expression, while the 40 kDa form was nuclear expressed. The expression of AKAP95, cyclin E1, LMW-E1 and -E2, might be regulated by cAMP. We conclude that AKAP95 might promote cell cycle progression by interacting with cyclin E1 and LMW-E2. LMW-E2, but not cyclin E2, might be involved in G1/S transition. The binding of AKAP95 and LMW-E1 was found throughout cell cycle. PMID:27158371

  12. Fluorophore-assisted carbohydrate electrophoresis for the determination of molecular mass of heparins and low-molecular-weight (LMW) heparins.

    PubMed

    Buzzega, Dania; Maccari, Francesca; Volpi, Nicola

    2008-11-01

    We report the use of fluorophore-assisted carbohydrate electrophoresis (FACE) to determine the molecular mass (M) values of heparins (Heps) and low-molecular-weight (LMW)-Hep derivatives. Hep are labeled with 8-aminonaphthalene-1,3,6-trisulfonic acid and FACE is able to resolve each fraction as a discrete band depending on their M. After densitometric acquisition, the migration distance of each Hep standard is acquired and the third-grade polynomial calibration standard curve is determined by plotting the logarithms of the M values as a function of migration ratio. Purified Hep samples having different properties, pharmaceutical Heps and various LMW-Heps were analyzed by both FACE and conventional high-performance size-exclusion liquid chromatography (HPSEC) methods. The molecular weight value on the top of the chromatographic peak (Mp), the number-average Mn, weight-average Mw and polydispersity (Mw/Mn) were examined by both techniques and found to be similar. This approach offers certain advantages over the HPSEC method. The derivatization process with 8-aminonaphthalene-1,3,6-trisulfonic acid is complete after 4 h so that many samples may be analyzed in a day also considering that multiple samples can be run simultaneously and in parallel and that a single FACE analysis requires approx. 15 min. Furthermore, FACE is a very sensitive method as it requires approx. 5-10 microg of Heps, about 10-100-fold lower than samples and standards used in HPSEC evaluation. Finally, the utilization of mini-gels allows the use of very low amounts of reagents with neither expensive equipment nor any complicated procedures having to be applied. This study demonstrates that FACE analysis is a sensitive method for the determination of the M values of Heps and LMW-Heps with possible utilization in virtually any kind of research and development such as quality control laboratories due to its rapid, parallel analysis of multiple samples by means of common and simple largely used

  13. Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice.

    PubMed

    Chou, Yen-Jung; Kan, Wei-Chih; Chang, Chieh-Min; Peng, Yi-Jen; Wang, Hsien-Yi; Yu, Wen-Chun; Cheng, Yu-Hsuan; Jhang, Yu-Rou; Liu, Hsia-Wei; Chuu, Jiunn-Jye

    2016-01-01

    Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM). Inonotus obliquus (IO) is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs) have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ)-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP), from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD) plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10-100 kDa, LIOP (300 mg/kg) had progressively increased their sensitivity to glucose (less insulin tolerance), reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR) compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL) incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1), while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

  14. Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice

    PubMed Central

    Chou, Yen-Jung; Kan, Wei-Chih; Chang, Chieh-Min; Peng, Yi-Jen; Wang, Hsien-Yi; Yu, Wen-Chun; Cheng, Yu-Hsuan; Jhang, Yu-Rou; Liu, Hsia-Wei; Chuu, Jiunn-Jye

    2016-01-01

    Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM). Inonotus obliquus (IO) is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs) have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ)-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP), from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD) plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg) had progressively increased their sensitivity to glucose (less insulin tolerance), reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR) compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL) incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1), while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

  15. Identification and analysis of low-molecular-weight dissolved organic carbon in subglacial basal ice ecosystems by ion chromatography

    NASA Astrophysics Data System (ADS)

    O'Donnell, Emily C.; Wadham, Jemma L.; Lis, Grzegorz P.; Tranter, Martyn; Pickard, Amy E.; Stibal, Marek; Dewsbury, Paul; Fitzsimons, Sean

    2016-07-01

    Determining the concentration and composition of dissolved organic carbon (DOC) in glacial ecosystems is important for assessments of in situ microbial activity and contributions to wider biogeochemical cycles. Nonetheless, there is limited knowledge of the abundance and character of DOC in basal ice and the subglacial environment and a lack of quantitative data on low-molecular-weight (LMW) DOC components, which are believed to be highly bioavailable to microorganisms. We investigated the abundance and composition of DOC in basal ice via a molecular-level DOC analysis. Spectrofluorometry and a novel ion chromatographic method, which has been little utilized in glacial science for LMW-DOC determinations, were employed to identify and quantify the major LMW fractions (free amino acids, carbohydrates, and carboxylic acids) in basal ice from four glaciers, each with a different type of overridden material (i.e. the pre-entrainment sedimentary type such as lacustrine material or palaeosols). Basal ice from Joyce Glacier (Antarctica) was unique in that 98 % of the LMW-DOC was derived from the extremely diverse free amino acid (FAA) pool, comprising 14 FAAs. LMW-DOC concentrations in basal ice were dependent on the bioavailability of the overridden organic carbon (OC), which in turn was influenced by the type of overridden material. Mean LMW-DOC concentrations in basal ice from Russell Glacier (Greenland), Finsterwalderbreen (Svalbard), and Engabreen (Norway) were low (0-417 nM C), attributed to the relatively refractory nature of the OC in the overridden palaeosols and bedrock. In contrast, mean LMW-DOC concentrations were an order of magnitude higher (4430 nM C) in basal ice from Joyce Glacier, a reflection of the high bioavailability of the overridden lacustrine material (> 17 % of the sediment OC comprised extractable carbohydrates, a proxy for bioavailable OC). We find that the overridden material may act as a direct (via abiotic leaching) and indirect (via

  16. Enhanced gene delivery using biodegradable poly(ester amine)s (PEAs) based on low-molecular-weight polyethylenimine and poly(epsilon-caprolactone)-pluronic-poly(epsilon-caprolactone).

    PubMed

    Liu, Tingting; Yu, Xiujun; Kan, Bing; Guo, Qingfa; Wang, Xiuhong; Shi, Shuai; Guo, Gang; Luo, Feng; Zhao, Xia; Wei, Yuquan; Qian, Zhiyong

    2010-08-01

    In this paper, the poly(ester amine)s (PEAs) were successfully prepared from low-molecular-weight PEI (Mn = 2000) and Poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCFC) copolymers using isophorone diisocyanate (IPDI) as cross-linker. The obtained PEAs copolymers are biodegradable and water-soluble. The PEAs/DNA complexes showed effective and stable DNA condensation with the particle size < or = 200 nm and zeta potential > or =10 mV, indicating its potential for intracellular delivery. Compared to the unmodified low-molecular-weight PEI, PEAs displayed similarly low cytotoxicity in all two cell lines (293T: Human kidney carcinoma, HUVEC: Human umbilical vein Endothelial cell) and revealed much higher transfection efficiency in 293T cell lines. Therefore these PEAs might be a novel safe and efficient polymeric gene delivery vectors.

  17. Inkjet-printed gold nanoparticle surfaces for the detection of low molecular weight biomolecules by laser desorption/ionization mass spectrometry.

    PubMed

    Marsico, Alyssa L M; Creran, Brian; Duncan, Bradley; Elci, S Gokhan; Jiang, Ying; Onasch, Timothy B; Wormhoudt, Joda; Rotello, Vincent M; Vachet, Richard W

    2015-11-01

    Effective detection of low molecular weight compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is often hindered by matrix interferences in the low m/z region of the mass spectrum. Here, we show that monolayer-protected gold nanoparticles (AuNPs) can serve as alternate matrices for the very sensitive detection of low molecular weight compounds such as amino acids. Amino acids can be detected at low fmol levels with minimal interferences by properly choosing the AuNP deposition method, density, size, and monolayer surface chemistry. By inkjet-printing AuNPs at various densities, we find that AuNP clusters are essential for obtaining the greatest sensitivity. Graphical Abstract ᅟ.

  18. Free-radical scavenging properties of low molecular weight peptide(s) isolated from S1 cultivar of mulberry leaves and their impact on Bombyx mori (L.) (Bombycidae)

    PubMed Central

    2014-01-01

    The mulberry leaves have been considered as a sole food source for silkworm, Bombyx mori (L.). In present work an attempt was made to investigate the role of low molecular weight peptide(s) isolated from mulberry leaves on silkworm rearing. Also we have tried to find out the role of free-radical scavenging activities of isolated peptide(s) on silkworm growth. Larval growth rate was found effective under the influence of peptide(s). Consumption rate of larvae after peptide(s) treatment on mulberry leaves was significantly enhanced over control. High antioxidant activity was found in Low molecular weight peptide(s) which have an effect on silkworm. PMID:24612781

  19. Solubility of crystalline organic compounds in high and low molecular weight amorphous matrices above and below the glass transition by zero enthalpy extrapolation.

    PubMed

    Amharar, Youness; Curtin, Vincent; Gallagher, Kieran H; Healy, Anne Marie

    2014-09-10

    Pharmaceutical applications which require knowledge of the solubility of a crystalline compound in an amorphous matrix are abundant in the literature. Several methods that allow the determination of such data have been reported, but so far have only been applicable to amorphous polymers above the glass transition of the resulting composites. The current work presents, for the first time, a reliable method for the determination of the solubility of crystalline pharmaceutical compounds in high and low molecular weight amorphous matrices at the glass transition and at room temperature (i.e. below the glass transition temperature), respectively. The solubilities of mannitol and indomethacin in polyvinyl pyrrolidone (PVP) K15 and PVP K25, respectively were measured at different temperatures. Mixtures of undissolved crystalline solute and saturated amorphous phase were obtained by annealing at a given temperature. The solubility at this temperature was then obtained by measuring the melting enthalpy of the crystalline phase, plotting it as a function of composition and extrapolating to zero enthalpy. This new method yielded results in accordance with the predictions reported in the literature. The method was also adapted for the measurement of the solubility of crystalline low molecular weight excipients in amorphous active pharmaceutical ingredients (APIs). The solubility of mannitol, glutaric acid and adipic acid in both indomethacin and sulfadimidine was experimentally determined and successfully compared with the difference between their respective calculated Hildebrand solubility parameters. As expected from the calculations, the dicarboxylic acids exhibited a high solubility in both amorphous indomethacin and sulfadimidine, whereas mannitol was almost insoluble in the same amorphous phases at room temperature. This work constitutes the first report of the methodology for determining an experimentally measured solubility for a low molecular weight crystalline solute

  20. Matrix-assisted and polymer-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of low molecular weight polystyrenes and polyethylene glycols.

    PubMed

    Woldegiorgis, Andreas; Löwenhielm, Peter; Björk, Anders; Roeraade, Johan

    2004-01-01

    Recently, matrices based on oligomers of dioxin and thiophene (polymer-assisted laser desorption/ionization (PALDI)) have been described for mass spectrometric (MS) analysis of low molecular weight compounds (Woldegiorgis A, von Kieseritzky F, Dahlstedt E, Hellberg J, Brinck T, Roeraade J. Rapid Commun. Mass Spectrom. 2004; 18: 841-852). In this paper, we report the use of PALDI matrices for low molecular weight polymers. An evaluation with polystyrene and polyethylene glycol showed that no charge transfer ionization occurs. Ionization is mediated through metal ion adduction. Comparison of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) data for two very low molecular weight polymers with data obtained from size-exclusion chromatography (SEC) revealed a systematic difference regarding mean molecular weight and dispersity. Further, the mass spectra obtained with PALDI matrices had a higher signal-to-noise ratio than the spectra obtained with conventional matrices. For polymers with higher molecular weights (>1500 Da), the conventional matrices gave better performance. For evaluation of the MALDI spectra, three non-linear mathematical models were evaluated to model the cumulative distributions of the different oligomers and their maximal values of Mw, Mn and PDI. Models based on sigmoidal or Boltzmann equations proved to be most suitable. Objective modeling tools are necessary to compare different sample and instrumental conditions during method optimization of MALDI analysis of polymers, since the bias between MALDI and SEC data can be misleading.

  1. Investigation of colloidal graphite as a matrix for matrix-assisted laser desorption/ionisation mass spectrometry of low molecular weight analytes.

    PubMed

    Warren, Alexander D; Conway, Ulric; Arthur, Christopher J; Gates, Paul J

    2016-07-01

    The analysis of low molecular weight compounds by matrix-assisted laser desorption/ionisation mass spectrometry is problematic due to the interference and suppression of analyte ionisation by the matrices typically employed - which are themselves low molecular weight compounds. The application of colloidal graphite is demonstrated here as an easy to use matrix that can promote the ionisation of a wide range of analytes including low molecular weight organic compounds, complex natural products and inorganic complexes. Analyte ionisation with colloidal graphite is compared with traditional organic matrices along with various other sources of graphite (e.g. graphite rods and charcoal pencils). Factors such as ease of application, spectra reproducibility, spot longevity, spot-to-spot reproducibility and spot homogeneity (through single spot imaging) are explored. For some analytes, considerable matrix suppression effects are observed resulting in spectra completely devoid of matrix ions. We also report the observation of radical molecular ions [M(-●) ] in the negative ion mode, particularly with some aromatic analytes. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Aqueous biphasic system based on low-molecular-weight polyethylene glycol for one-step separation of crude polysaccharides from Pericarpium granati using high-speed countercurrent chromatography.

    PubMed

    Zhou, Xin-Yu; Zhang, Jing; Xu, Rui-Ping; Ma, Xue; Zhang, Zhi-Qi

    2014-10-01

    The aqueous biphasic system (ABS) plays a key role in the separation of bioactive substances, and the establishment and application of a low-molecular-weight polyethylene glycol (PEG) ABS remains a challenge in high-speed countercurrent chromatography (HSCCC). In this work, an ABS of low-molecular-weight PEG, namely PEG400-Na2SO4-H2O (20%-16%-64%, w/w/w), was developed on the basis of the phase diagram, and the phase forming time and ratio, and applied to HSCCC for the separation of polysaccharides. The crude polysaccharide extracted from Pericarpium granati (PGP) was successfully separated and three purified polysaccharides were obtained: PGP-1, with an average molecular weight of 13,210Da and composed of xylose (12.4%), ribose (10.1%), and glucose (77.5%); PGP-2, which is a homogeneous polysaccharide with an average molecular weight of 2584Da and consists of mannose; and PGP-3, with an average molecular weight of 2459Da and composed of ribose (51.4%), mannose (26.7%), and glucose (21.9%). This success shows that an ABS based on low-molecular-weight PEG could be applied to HSCCC separation technology.

  3. Investigation of colloidal graphite as a matrix for matrix-assisted laser desorption/ionisation mass spectrometry of low molecular weight analytes.

    PubMed

    Warren, Alexander D; Conway, Ulric; Arthur, Christopher J; Gates, Paul J

    2016-07-01

    The analysis of low molecular weight compounds by matrix-assisted laser desorption/ionisation mass spectrometry is problematic due to the interference and suppression of analyte ionisation by the matrices typically employed - which are themselves low molecular weight compounds. The application of colloidal graphite is demonstrated here as an easy to use matrix that can promote the ionisation of a wide range of analytes including low molecular weight organic compounds, complex natural products and inorganic complexes. Analyte ionisation with colloidal graphite is compared with traditional organic matrices along with various other sources of graphite (e.g. graphite rods and charcoal pencils). Factors such as ease of application, spectra reproducibility, spot longevity, spot-to-spot reproducibility and spot homogeneity (through single spot imaging) are explored. For some analytes, considerable matrix suppression effects are observed resulting in spectra completely devoid of matrix ions. We also report the observation of radical molecular ions [M(-●) ] in the negative ion mode, particularly with some aromatic analytes. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27434807

  4. Utilization of low molecular weight organics by soil microorganisms: combination of 13C-labelling with PLFA analysis

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Dippold, Michaela; Kuzyakov, Yakov

    2014-05-01

    Microbial metabolisation is the main transformation pathway of low molecular weight organic substances (LMWOS), but detailed knowledge concerning the fate of LMWOS in soils is strongly limited. Considering that various LMWOS classes enter biochemical cycles at different steps, we hypothesise that the percentage of their LMWOS-Carbon (C) used for microbial biomass (MB) production and consequently medium-term stabilisation in soil is different. We traced the three main groups of LMWOS: amino acids, sugars and carboxylic acids, by uniformly labelled 13C-alanine, -glutamate, -glucose, -ribose, -acetate and -palmitate. Incorporation of 13C from these LMWOS into MB (fumigation-extraction method) and into phospholipid fatty acids (PLFAs) (Bligh-Dyer extraction, purification and GC-C-IRMS measurement) was investigated under field conditions 3 d and 10 d after LMWOS application. The activity of microbial utilization of LMWOS for cell membrane construction was estimated by replacement of PLFA-C with 13C. Decomposition of LMWOS-C comprised 20-65% of the total label, whereas incorporation of 13C into MB amounted to 20-50% of initially applied 13C on day three and was reduced to 5-30% on day 10. Incorporation of 13C-labelled LMWOS into MB followed the trend sugars > carboxylic acids > amino acids. Differences in microbial utilisation between LMWOS were observed mainly at day 10. Thus, instead of initial rapid uptake, further metabolism within microbial cells accounts for the individual fate of C from different LMWOS in soils. Incorporation of 13C from each LMWOS into each PLFA occurred, which reflects the ubiquitous ability of all functional microbial groups for LMWOS utilization. The preferential incorporation of palmitate can be attributed to its role as a direct precursor for many fatty acids (FAs) and PLFA formation. Higher incorporation of alanine and glucose compared to glutamate, ribose and acetate reflect the preferential use of glycolysis-derived substances in the FAs

  5. Effect of dalteparin, a low-molecular-weight heparin, as adjunctive therapy in patients with Kawasaki disease: a retrospective study

    PubMed Central

    2014-01-01

    Background Dalteparin, a low-molecular-weight heparin, has anticoagulant and anti-angiogenic activity. This study investigated whether dalteparin reduced coronary artery lesion (CAL) prevalence, and resistance to intravenous immunoglobulin (IVIG) therapy in Kawasaki disease (KD). Methods This retrospective study comprised two parts. In the first cohort, 126 patients with KD (68 male, 58 female; median age: 22 months, range: 1–67 months) admitted to Nihon University Nerima-Hikarigaoka Hospital from January 2004 to June 2008, received either dalteparin 75 IU/kg/day, IVIG 400 mg/kg/day for 5 consecutive days, and aspirin 30 mg/kg/day, or dalteparin 75 IU/kg/day and aspirin 30 mg/kg/day, until clinical improvement. Control data came from the 2005–6 Nationwide KD survey. In the second cohort, 112 patients with KD (59 male, 53 female; median age: 19 months, range: 1–66 months) admitted from June 2010 to February 2012, received either dalteparin 75 IU/kg/day, IVIG 2.0 g/kg over 12 h, and aspirin 30 mg/kg/day, or dalteparin 75 IU/kg/day and aspirin 30 mg/kg/day. Control data came from the 2009–10 Nationwide KD survey. No patients enrolled in the nationwide surveys received dalteparin. All patients at our institution were given dalteparin in their combination therapy. Results A comparison of the first cohort with controls in the nationwide survey showed that the prevalence of initial administration of IVIG was 80.2% versus 86.0%; the rate of additional IVIG administration was 7.1% versus 14.0% (p = 0.03); CAL prevalence in the acute period was 4.8% versus 11.9% (p < 0.01); and the prevalence of cardiovascular sequelae was 0% versus 3.8% (p < 0.05). A comparison of the second cohort with controls in the nationwide survey showed that the rate of initial administration of IVIG was 92.9% versus 89.5%; the rate of additional IVIG administration was 8.9% versus 17.1% (p = 0.02); the prevalence of resistance to IVIG was 3.6% versus 14.9% (p

  6. Deep venous thrombosis and pulmonary embolism. Part 1. Initial treatment: usually a low-molecular-weight heparin.

    PubMed

    2013-04-01

    Patients with deep venous thrombosis are at a short-term risk of symptomatic or even life-threatening pulmonary embolism, and a long-term risk of post-thrombotic syndrome, characterised by lower-limb pain, varicose veins, oedema, and sometimes skin ulcers. What is the best choice of initial antithrombotic therapy following deep venous thrombosis or pulmonary embolism, in terms of mortality and short-term and long-term complications? How do the harm-benefit balances of the different options compare? To answer these questions, we reviewed the available literature using the standard Prescrire methodology. Unfractionated heparin has documented efficacy in reducing mortality and recurrent thromboembolic events in patients with pulmonary embolism or symptomatic proximal (above-knee) deep venous thrombosis. The authors of a systematic review selected 23 trials of low-molecular-weight heparin (LMWH) versus adjusted-dose unfractionated heparin in a total of 9587 patients. Deaths, recurrences and major bleeds were less frequent with LMWH than with unfractionated heparin. The results of other meta-analyses are similar, but all are undermined by a probable publication bias and methodological flaws. Compared to unfractionated heparin, LMWHs have the advantage of fixed-dose administration, once or twice daily, by subcutaneous injection. All available LMWHs seem to have similar efficacy. Those with the longest experience of use are enoxaparin, dalteparin and nadroparin. The harm-benefit balances of fondaparinux and rivaroxaban do not appear more favourable than that of an LMWH followed by an adjusted-dose vitamin K antagonist. A meta-analysis included 12 trials comparing thrombolysis with anticoagulation alone in 700 patients with deep venous thrombosis. Adding a thrombolytic drug did not reduce mortality or the incidence of pulmonary embolism, whereas it increased the incidence of bleeding. A meta-analysis of 13 trials failed to show that adding a thrombolytic drug to initial

  7. Characterising low molecular weight dissolved organic carbon compounds in subglacial systems; implications for subglacial metabolic activity and potential downstream export

    NASA Astrophysics Data System (ADS)

    Lawson, Emily; Wadham, Jemma; Lis, Grzegorz; Telling, Jon

    2010-05-01

    Glaciers and ice sheets represent ~10% of the contemporary global surface coverage, yet remain one of the least explored sectors of the Earth's biosphere. The basal regions of these ice masses, known as subglacial environments, are capable of harbouring a diverse range of microorganisms that are often metabolically active despite the lack of sunlight, the cold temperatures and nutrient scarcity. Here, we consider the potential for such environments to be active components of the Earth's biogeochemical cycles. Subglacial environments have traditionally been excluded from global carbon budgets because they were assumed to be predominantly abiotic. Organic carbon (OC) reservoirs and transformations were also believed to be limited. However, significant stores of bioavailable carbon are thought to be present in glacially-overridden material, providing a potential substrate for in situ microbial metabolism. We examine the molecular characteristics of dissolved OC in basal ice and subglacial runoff from two glacier/ice-sheet systems with contrasting organic carbon substrates; Russell/Leverett Glacier, Greenland ice sheet, and Engabreen, Norway, to determine the range of dissolved low molecular weight OC (LMWOC) compounds and their relative bioavailability. Overridden material beneath the Greenland ice sheet is relatively young and organic-rich, contrasting with the older crystalline bedrock/continental shield that was overridden during glaciation at Engabreen. We first utilise a combination of fluorescence spectroscopy and ion chromatography to identify and quantify volatile fatty acids, carbohydrates and amino acids in basal ice. Volatile fatty acids are key metabolic substrates and their provision is thought to be a primary control on subglacial metabolic activity. We then provide a temporal record of amino acids and carbohydrates in subglacial runoff from Leverett Glacier (June 23rd - August 18th 2009), and compare this with subglacial runoff from Engabreen (2008 melt

  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. Hydrolysis of low-molecular-weight oligosaccharides and oligosaccharide alditols by pig intestinal sucrase/isomaltase and glucosidase/maltase.

    PubMed

    Hertel, S; Heinz, F; Vogel, M

    2000-06-30

    The ability of purified pig intestinal sucrase/isomaltase (SI; EC 3.2.1.10/48) and glucosidase/maltase (GM; EC 3.2.1.20) to hydrolyze di- and oligosaccharides consisting of D-glucose and D-fructose residues and the corresponding alditols was studied. The products, after incubation, reflect different binding patterns at both catalytic sites of SI. The active site of the sucrase subunit cleaves alpha,beta-(1-->2) glycosidic bonds, and only two monomer units of the substrates bind with favorable affinity. Oligosaccharides and reduced oligosaccharides containing alpha-(1--6) and alpha-(1-->1) glycosidic bonds are hydrolyzed by isomaltase, and for the active site of this subunit more than two subsites were postulated. Moreover, different binding sites for various aglycons seem to exist for isomaltase. Oligosaccharide alcohols are cleaved at lower rates if the reduced sugar residue occupies the aglycon binding site. GM also hydrolyzes alpha-(1-->1) linkages, but at a lower rate. The enzyme has the ability to bind compounds containing residues other than D-glucose. There are indications for similarities between GM and the isomaltase subunit of SI in the binding mode of oligosaccharides.

  10. Characterization of low molecular weight dissolved natural organic matter along the treatment trait of a waterworks using Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Zhang, Haifeng; Zhang, Yahe; Shi, Quan; Ren, Shuoyi; Yu, Jianwei; Ji, Feng; Luo, Wenbin; Yang, Min

    2012-10-15

    Dissolved natural organic matter (DOM), particularly the low molecular weight DOM, can affect the performance of water treatment processes and serve as a main precursor of disinfection by-products (DBPs) during chlorination. In this study, electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize the low molecular weight DOM along the treatment trait of a conventional drinking water treatment plant. The ESI FT-ICR MS data showed that various C, H, O-only class species were the major components in the source water. According to the van Krevelen diagram analysis, lignin- and tannin-like compounds were the most abundant components. Within an isobaric group, the DOM molecules with a high degree of oxidation (high O/C value) were preferentially removed during coagulation, while those with low degree of oxidation were found to be more reactive toward chlorine. In addition, 357 one-chlorine containing products and 199 two-chlorine containing products formed during chlorination were detected in the chlorination effluent sample at a high confidence level. The chlorinated products can be arranged into series, suggesting that they were originated from C, H, O-only precursor compounds, which were in series related by the replacement of CH(4) against oxygen. For the first time, this study explored the behavior of low molecular weight DOM along a drinking water treatment trait on the molecular level, and revealed the presence of abundant unknown chlorinated products, which are probably rich in carboxylic and phenolic groups, in drinking water.

  11. Efficacy and Safety of a Low Molecular Weight Hyaluronic Acid Topical Gel in the Treatment of Facial Seborrheic Dermatitis Final Report

    PubMed Central

    Rowland Powell, Callie

    2014-01-01

    Objective: Hyaluronic acid sodium salt gel 0.2% is a topical device effective in reducing skin inflammation. Facial seborrheic dermatitis, characterized by erythema and or flaking/scaling in areas of high sebaceous activity, affects up to five percent of the United States population. Despite ongoing study, the cause of the condition is yet unknown, but has been associated with yeast colonization and resultant immune derived inflammation. First-line management typically is with keratolytics, topical steroids, and topical antifungals as well as the targeted immunosuppressant agents pimecrolimus and tacrolimus. The objective of this study was to evaluate the efficacy and safety of a novel topical antiinflammatory containing low molecular weight hyaluronic acid. Design and setting: Prospective, observational, non-blinded safety and efficacy study in an outpatient setting. Participants: Individuals 18 to 75 years of age with facial seborrheic dermatitis. Measurements: Outcome measures included scale, erythema, pruritus, and the provider global assessment, all measured on a five-point scale. Subjects were assessed at baseline, Week 2, Week 4, and Week 8. Results: Final data with 13 of 17 subjects are presented. Hyaluronic acid sodium salt gel 0.2% was shown through visual grading assessments to improve the provider global assessment by 65.48 percent from baseline to Week 4. Reductions in scale, erythema, and pruritus were 76.9, 64.3, and 50 percent, respectively, at Week 4. At Week 8, the provider global assessment was improved from baseline in 92.3 percent of subjects. Conclusion: Treatment with topical low molecular weight hyaluronic acid resulted in improvement in the measured endpoints. Final data reveal continued improvement from that seen in the interim data shown previously. Topical low molecular weight hyaluronic acid is another option that may be considered for the treatment of facial seborrheic dermatitis in the adult population. Compliance and tolerance were

  12. Additive and synergistic effects of a low-molecular-weight, heparin-like molecule and low doses of cyclosporin in preventing arterial graft rejection in rats.

    PubMed

    Plissonnier, D; Amichot, G; Lecagneux, J; Duriez, M; Gentric, D; Michel, J B

    1993-01-01

    Arteriosclerotic intimal proliferation is one of the main long-term complications of organ transplantation. Low-molecular-weight, heparin-like molecules prevent myointimal proliferation in arterial wall injury and limit rejection in skin allografts. Cyclosporin limits rejection but has no major effect on intimal proliferation. Therefore, an experimental protocol was designed to test whether heparin-like molecules interacted with low doses of cyclosporin to prevent arterial wall immune system injury and response in a model of arterial graft rejection in normotensive and hypertensive rats. Aortic allografts were performed in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) normotensive control rats. Four groups of 10 allografted (SHR and WKY) rats were used: one group was treated with placebo, one with low doses of cyclosporin (2 mg/kg body wt per day), one with low-molecular-weight, heparin-like molecule (1 mg/kg body wt per hour), and one with low doses of cyclosporin plus low-molecular-weight, heparin-like molecule. Ten SHRs and 10 WKYs were isografted and served as the control groups. All rats were killed 8 weeks after aortic grafting. Structural parameters of the grafted segment were measured by morphometric analysis on formalin-fixed sections with specific stains. The classical signs of immune system injury and response were present in the untreated allografts in SHRs and WKYs: inflammatory infiltration of the adventitia, medial injury, and intimal proliferative response. Low doses of cyclosporin had a significant beneficial effect on immune medial injury by increasing medial thickness and the number of remaining smooth muscle cells and decreasing the extracellular matrix injury. Cyclosporin had no protective effect on intimal proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Successful Treatment of Dental Infection-Induced Chronic Cavernous Sinus Thrombophlebitis With Antibiotics and Low-Molecular-Weight Heparin: Two Case Reports.

    PubMed

    Li, Yuan; Zheng, Bo; Chen, Kangning; Gui, Li

    2015-08-01

    Two patients developed cavernous sinus thrombophlebitis from a tooth infection. A 36-year-old man experienced a severe headache with bilateral third and sixth cranial nerve palsies after extraction of his left upper third molar. Another 53-year-old diabetic man developed fever, headache, and bilateral complete ophthalmoplegia after a tooth infection. The brain magnetic resonance imaging scans of both patients showed bilateral cavernous sinus partial thrombosis. Broad-spectrum antibiotics plus low-molecular-weight heparin successfully resolved all symptoms. Both patients recovered fully without any recurrence at the 3-month follow-up visit.

  14. Successful Treatment of Dental Infection-Induced Chronic Cavernous Sinus Thrombophlebitis With Antibiotics and Low-Molecular-Weight Heparin: Two Case Reports.

    PubMed

    Li, Yuan; Zheng, Bo; Chen, Kangning; Gui, Li

    2015-08-01

    Two patients developed cavernous sinus thrombophlebitis from a tooth infection. A 36-year-old man experienced a severe headache with bilateral third and sixth cranial nerve palsies after extraction of his left upper third molar. Another 53-year-old diabetic man developed fever, headache, and bilateral complete ophthalmoplegia after a tooth infection. The brain magnetic resonance imaging scans of both patients showed bilateral cavernous sinus partial thrombosis. Broad-spectrum antibiotics plus low-molecular-weight heparin successfully resolved all symptoms. Both patients recovered fully without any recurrence at the 3-month follow-up visit. PMID:26173405

  15. Lack of correlation between turnover of low-molecular-weight dissolved organic carbon and differences in microbial community composition or growth across a soil pH gradient.

    PubMed

    Rousk, Johannes; Brookes, Philip C; Glanville, Helen C; Jones, David L

    2011-04-01

    We studied how soil pH (pHs 4 to 8) influenced the mineralization of low-molecular-weight (LMW)-dissolved organic carbon (DOC) compounds, and how this compared with differences in microbial community structure. The mineralization of LMW-DOC compounds was not systematically connected to differences in soil pH, consistent with soil respiration. In contrast, the microbial community compositions differed dramatically. This suggests that microbial community composition data will be of limited use in improving the predictive power of soil C models.

  16. Effects of specific domains of high-molecular-weight glutenin subunits’ on dough properties by an in vitro assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An in vitro system for incorporating bacterially produced high-molecular-weight glutenin subunits (HMW-GS) into doughs was used to study the effects of specific domains of the HMW-GS. Synergistic effects of incorporating into doughs both the Dx5 and Dy10 subunits are localized to the N-terminal do...

  17. Molecular Analysis of the Polymeric Glutenins with Gliadin-Like Characteristics That Were Produced by Acid Dispersion of Wheat Gluten.

    PubMed

    Murakami, Tetsuya; Nishimura, Takahisa; Kitabatake, Naofumi; Tani, Fumito

    2016-03-01

    We had earlier shown that the dispersion of wheat gluten in acetic acid solution conferred gliadin-like characteristics to the polymeric glutenins. To elucidate the molecular behavior of its polymeric glutenins, the characteristics of gluten powder prepared from dispersions with various types of acid were investigated in this study. Mixograph measurements showed that the acid-treated gluten powders, regardless of the type of acid, had dough properties markedly weakened in both resistance and elasticity properties, as though gliadin was supplemented. The polymeric glutenins extracted with 70% ethanol increased greatly in all acid-treated gluten powders. Size exclusion HPLC and SDS-PAGE indicated that the behavior of polymeric glutenins due to acid treatment was attributed to their subunit composition rich in high molecular weight glutenin subunit (HMW-GS) and not their molecular size. The gluten prepared with the addition of NaCl in acid dispersion had properties similar to those of the control gluten. The results suggest that ionic repulsion induced by acid dispersion made the polymeric glutenins rich in HMW-GS disaggregate, and therefore, act like gliadins.

  18. The methionine-rich low-molecular-weight chloroplast heat-shock protein: evolutionary conservation and accumulation in relation to thermotolerance.

    PubMed

    Downs, C; Heckathorn, S; Bryan, J; Coleman, J

    1998-02-01

    The evolutionary conservation of the low-molecular-weight chloroplast-localized heat-shock protein (LMW chlpHsp) in vascular plants was examined using immunological methods. An antibody (Abmet) specific to the LMW chlpHsp was produced using a synthetic 28-residue peptide containing the most conserved elements of its unique "methionine-rich domain" as an antigen. This antibody detected a heat-inducible low-molecular-weight chloroplast protein in plants of six divergent Anthophyta species, including C3, C4, CAM, monocot, and dicot species. Abmet also detected a LMW chlpHsp in species from the Divisions Psilotophyta, Equisetophyta, Polypodiophyta, and Ginkgophyta. A preliminary examination of the relationship between accumulation of the LMW chlpHsp and habitat was also conducted. Seven Anthophyta species originating from both warm- and cool-temperature habitats were grown at 28C and then heat stressed at 40C. A positive qualitative relationship between the accumulation of the LMW chlpHsp and organismal thermotolerance in these species was observed; similar results were obtained separately with four nonAnthophyta species. The strong evolutionary conservation of this LMW Hsp and its localization to the chloroplast, and the correlation between production of this protein and plant thermotolerance, suggest that the LMW chlpHsp plays an important role in adaptation to heat stress.

  19. Synthesis of heterogeneous mRNA-like RNA and low-molecular-weight RNA before the midblastula transition in embryos of Xenopus laevis

    SciTech Connect

    Nakakura, N.; Miura, T.; Yamana, K.; Ito, A.; Shiokawa, K.

    1987-10-01

    It has been proposed and is now widely accepted that in Xenopus laevis embryogenesis RNA synthesis starts only at and after 12 rounds of cleavage, at the time of the midblastula transition (MBT). In this report, however, we provide evidence that RNA synthesis takes place prior to the MBT stage in normally developing Xenopus embryos. In the present experiments, we cultured fertilized eggs in 80 mM phosphate buffer and loosened the adhesion between blastomeres, so that (/sup 3/H)uridine could be incorporated into blastomeres from the surrounding medium. By this method and also by microinjection of (/sup 3/H)GTP, we found that embryos synthesize heterogeneous, nonribosomal, high-molecular-weight RNAs and a relatively small amount of low-molecular-weight RNA as early as the sixth cleavage. RNAs synthesized were not of mitochondrial origin, and the synthesis was sensitive to actinomycin D and alpha-amanitin. From these results we conclude that mRNA-like RNA and low-molecular-weight RNA start to be synthesized during the cleavage stage.

  20. Low molecular weight oligomers of amyloid peptides display β-barrel conformations: A replica exchange molecular dynamics study in explicit solvent

    NASA Astrophysics Data System (ADS)

    De Simone, Alfonso; Derreumaux, Philippe

    2010-04-01

    The self-assembly of proteins and peptides into amyloid fibrils is connected to over 40 pathological conditions including neurodegenerative diseases and systemic amyloidosis. Diffusible, low molecular weight protein and peptide oligomers that form in the early steps of aggregation appear to be the harmful cytotoxic species in the molecular etiology of these diseases. So far, the structural characterization of these oligomers has remained elusive owing to their transient and dynamic features. We here address, by means of full atomistic replica exchange molecular dynamics simulations, the energy landscape of heptamers of the amyloidogenic peptide NHVTLSQ from the beta-2 microglobulin protein. The simulations totaling 5 μs show that low molecular weight oligomers in explicit solvent consist of β-barrels in equilibrium with amorphous states and fibril-like assemblies. The results, also accounting for the influence of the pH on the conformational properties, provide a strong evidence of the formation of transient β-barrel assemblies in the early aggregation steps of amyloid-forming systems. Our findings are discussed in terms of oligomers cytotoxicity.

  1. Comparative oxidation of 2-propyn-1-ol with other low molecular weight unsaturated and saturated primary alcohols by bovine liver catalase in vitro.

    PubMed

    DeMaster, E G; Dahlseid, T; Redfern, B

    1994-01-01

    The oxidative metabolism of low molecular weight, saturated and unsaturated, primary alcohols, which include ethanol, allyl alcohol (2-propen-1-ol), and propargyl alcohol (2-propyn-1-ol), is generally accepted to occur via alcohol dehydrogenase; however, compared to other short-chain alcohols, 2-propyn-1-ol is a poor substrate for this enzyme. Accordingly, we have examined liver catalase as an alternative pathway for the oxidation or bioactivation of 2-propyn-1-ol to 2-propyn-1-al, a highly reactive alpha,beta-unsaturated aldehyde. The rates of oxidation for a series of low molecular weight, saturated, primary alcohols and selected unsaturated alcohols were determined for the bovine liver catalase-catalyzed reaction by measuring aldehyde production over time employing a GC procedure. A negative correlation was found for log rates of oxidation versus molecular size (volume) of the substrates (p < 0.01); however, the rate of oxidation for 2-propyn-1-ol was higher than predicted by this relation and was 30% greater than the oxidation rate determined for ethanol. In addition, 2-propyn-1-ol-derived 2-propyn-1-al inhibited the peroxidatic and catalytic activities of catalase, whereas 2-propen-1-ol-derived 2-propen-1-al had no effect on these activities of catalase. Inhibition was blocked by GSH; and the activity was not restored to the inhibited enzyme by GSH treatment or dialysis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8075374

  2. Fabrication and Anti-Fouling Properties of Photochemically and Thermally Immobilized Poly(Ethylene Oxide) and Low Molecular Weight Poly(Ethylene Glycol) Thin Films

    PubMed Central

    Wang, Hui; Ren, Jin; Hlaing, Aye; Yan, Mingdi

    2010-01-01

    Poly(ethylene oxide) (PEO) and