Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly(L-glutamic acid) (PGA)-cystamine-[gadolinium (Gd)-DO3A] was prepared in high yield with a high Gd-DO3A conjugation efficiency. Approximately 55% of the carboxylic groups in PGA were loaded with Gd-DO3A via cystamine as the spacer. Cystamine can be readily cleaved by endogenous thiols to release the Gd(III) chelates from the conjugate facilitating Gd(III) excretion after the magnetic resonance imaging (MRI). The contrast-enhanced MRI with PGA-cystamine-(Gd-DO3A) was investigated in mice bearing MDA-MB-231 breast carcinoma xenografts. PGA-1,6-hexanediamine-(Gd-DO3A), a paramagnetic polymer conjugate of a nondegradable spacer, was used as a control. Both conjugates resulted in similar contrast enhancement in the heart, vasculature, liver and kidneys in the first hour post injection. More substantial signal intensity reduction was observed for PGA-cystamine-(Gd-DO3A) in these organs than PGA-1,6-hexanediamine-(Gd-DO3A) due to release of the Gd chelates from PGA-cystamine-(Gd-DO3A) after the cleavage of the disulfide spacer by the endogenous thiols. Both conjugates resulted in similar tumor enhancement with approximately 70% increased signal intensity in the tumor periphery and 10-40% increased signal intensity in tumor interstitium. No cross-reaction was observed between PGA-cystamine-(Gd-DO3A) and human serum albumin, a plasma protein containing a cysteine residue. PGA-cystamine-(Gd-DO3A) resulted in significantly lower Gd(III) tissue retention than PGA-1,6-hexanediamine-(Gd-DO3A) 10 days after the injection in the mice (P<.05). The conjugation of Gd(III) chelates to biomedical copolymers via the degradable disulfide spacer resulted in significant contrast enhancement in the blood pool and tumor tissue but minimal long-term Gd(III) tissue retention.
Magn Reson Imaging 2006 Sep
PMID:Biodegradable cystamine spacer facilitates the clearance of Gd(III) chelates in poly(glutamic acid) Gd-DO3A conjugates for contrast-enhanced MR imaging. 1691 10

The extracellular matrix produced by Bacillus subtilis B-1, an environmental strain that forms robust floating biofilms, was purified, and determined to be composed predominantly of gamma-polyglutamate (gamma-PGA), with a molecular mass of over 1,000 kDa. Both biofilm formation and gamma-PGA production by B. subtilis B-1 increased with increasing Mn(2+) or glycerol concentration. gamma-PGA was produced in a growth-associated manner in standing culture, and floating biofilms were formed. However, gamma-PGA was produced in a non-growth-associated manner in shaking culture conditions. When B. subtilis B-1 was grown in a microaerated culture system, floating biofilm formation and gamma-PGA production were significantly retarded, suggesting that oxygen depletion is involved in the initial steps of floating biofilm formation in standing culture. Proteomic analysis of membrane proteins demonstrated that flagellin, oligopeptide permease and Vpr protease precursor were the major proteins produced by cells in a floating biofilm and a colony.
Microbiology (Reading) 2006 Sep
PMID:Biofilm formation by a Bacillus subtilis strain that produces gamma-polyglutamate. 1694 74

The purpose of this study was to evaluate host response and soft-tissue regeneration after poly(lactic acid) (PLA) mesh implantation in a rat model, in comparison with light-weight polypropylene (PPL) and poly(glycolic acid) (PGA) meshes. Full-thickness abdominal wall defects were created in 45 Wistar rats and reconstructed with 15 PLA(94), 15 PPL and 15 PGA meshes. Animals were killed on days 7, 30 and 90 to evaluate the presence of adhesions and changes in tensile strength of the implants. Histopathology and immunohistochemistry were performed to evaluate the collagen deposition and the inflammatory response. Statistics were done using unpaired Student's t-test, Mann-Whitney rank sum test, Student-Newman-Keuls test and Bonferroni (Dunn) t-test. The inflammatory response induced by the PLA mesh implantation was significantly milder than after PPL mesh. In PLA, vascularity and collagen organization was significantly higher than in PPL and PGA at 30 and 90 days, and collagen composition score was significantly higher than in PPL at 7 and 30 days. In PLA, shrinkage was significantly lower than in PPL and PGA at 7 and 30 days. Elongation at break and tensile strength were comparable between PLA and PPL over the 90-day period. The PLA mesh induces a milder inflammatory response, more orderly collagen deposition than PPL, and preserved comparable tensile strength after 90 days.
Int Urogynecol J Pelvic Floor Dysfunct 2007 Sep
PMID:Long-lasting bioresorbable poly(lactic acid) (PLA94) mesh: a new approach for soft tissue reinforcement based on an experimental pilot study. 1721 29

The mainstream of recent anti-AIDS vaccines is a prime/boost approach with multiple doses of the target DNA of human immunodeficiency virus type 1 (HIV-1) and recombinant viral vectors. In this study, we have attempted to construct an efficient protein-based vaccine using biodegradable poly(gamma-glutamic acid) (gamma-PGA) nanoparticles (NPs), which are capable of inducing potent cellular immunity. A significant expansion of CD8+ T cells specific to the major histocompatibility complex class I-restricted gp120 epitope was observed in mice intranasally immunized once with gp120-carrying NPs but not with gp120 alone or gp120 together with the B-subunit of cholera toxin. Both the gp120-encapsulating and -immobilizing forms of NPs could induce antigen-specific spleen CD8+ T cells having a functional profile of cytotoxic T lymphocytes. Long-lived memory CD8+ T cells could also be elicited. Although a substantial decay in the effector memory T cells was observed over time in the immunized mice, the central memory T cells remained relatively constant from day 30 to day 238 after immunization. Furthermore, the memory CD8+ T cells rapidly expanded with boosting with the same immunogen. In addition, gamma-PGA NPs were found to be a much stronger inducer of antigen-specific CD8+ T-cell responses than nonbiodegradable polystyrene NPs. Thus, gamma-PGA NPs carrying various HIV-1 antigens may have great potential as a novel priming and/or boosting tool in current vaccination regimens for the induction of cellular immune responses.
J Virol 2007 Sep
PMID:Induction of potent CD8+ T-cell responses by novel biodegradable nanoparticles carrying human immunodeficiency virus type 1 gp120. 1760 61

The aim of this study was to investigate the adsorption and desorption kinetics of antibiotics to microporous bioceramics fabricated by a novel low temperature 3D powder direct printing process. The adsorption of vancomycin, ofloxacin and tetracycline onto hydroxyapatite, brushite and monetite showed a linear correlation with the drug concentration in the immersion solution, whereas a non-linear relationship was found between the immersion time and the amount of adsorbed drug. Differences in the total amount of adsorbed drugs were correlated to the specific surface areas of the matrices, which varied between 2.4-13.1 m(2)/g. Normalised drug loadings were found to be in the range of 1.5-1.8 mg/m(2) for vancomycin and ofloxacin, whereas higher loads of up to 5-7 mg/m(2) were obtained for tetracycline. Vancomycin and ofloxacin were rapidly released into PBS buffer within 1-2 days, while tetracycline showed a much slower release rate of approximately 25% after 5 days of immersion. Additional polymer impregnation of the drug loaded matrix with PLA/PGA polymer solutions enabled the release kinetics to be delayed such that sustained release was achieved in polymer ceramic biocomposites.
J Control Release 2007 Sep 26
PMID:Low temperature direct 3D printed bioceramics and biocomposites as drug release matrices. 1765 62

A novel polydimethylsiloxane (PDMS) surface modification method for microchip electrophoresis has been developed to make a stable and sufficient electroosmotic flow (EOF). Poly(l-glutamic acid) (PGA) which had ionizable carboxyl groups at a high pH-range was immobilized on the surface of microchannel fabricated with PDMS. The surface modification involved surface oxidation by plasma, the silanization of 3-aminopropyldimethylethoxysilane (APDMES) and immobilization of PGA via amide bond. The modified channel was extremely stable against consecutive electric power supply over 5h, and its long-term stability was demonstrated by the efficient separation of four amino acid derivatives reproducibly after a week. Additionally, homocysteine (Hcy), important risk factor of cardiovascular disease, osteoporosis and problems in pregnancy, was successfully measured in human serum in modified PDMS channel with the other thio amino acid simultaneously.
J Chromatogr A 2007 Sep 28
PMID:Steady surface modification of polydimethylsiloxane microchannel and its application in simultaneous analysis of homocysteine and glutathione in human serum. 1776 Nov 87

Natural health products (NHPs) or complementary and alternative medicine (CAM) are commonly used to prevent disorders or support the usual treatments of many diseases. XP-828L, a whey protein extract, has demonstrated potential benefits for the treatment of mild to moderate psoriasis. The aim of this study was to analyze further clinical data that demonstrated the clinical benefits and safety of the XP-828L in patients with psoriasis and the potential mechanism of action of this product in vitro. Oral administration (2.5 g, twice a day, over 112 days) of XP-828L in 42 human subjects with mild to moderate psoriasis improved their PGA scores (physician's global assessment). Moreover, no significant changes in haematology or hepatic and renal parameters were observed throughout the study period, indicating the safety of the product. In vitro experiments showed that XP-828L decreased the proliferation of concanavalin A (ConA)-stimulated murine splenocytes and their production of interleukin (IL)-2 and interferon (IFN)-gamma. Although the in vivo mechanism of action of XP-828L remains unknown, XP-828L represents an NHP to be used as an alternative or concomitant treatment for mild to moderate psoriasis and potentially for other immune-mediated diseases.
Can J Physiol Pharmacol 2007 Sep
PMID:XP-828L (Dermylex), a new whey protein extract with potential benefit for mild to moderate psoriasis. 1806 41

The aim of the study was to set up a novel fully enzymatic method for screening glucose and 1,5-anhydro-D-glucitol (1,5-AG) in one cuvette. We have determined glucose and 1,5-AG, based on glucokinase (GK) converting glucose to G6P, a compound that can be catalyzed ultimately into 6-PGA by G-6PD and its coenzyme NADP(+), and then calculated glucose concentration according to absorbance variety. Furthermore, pyranose oxidase was used to oxidize 1,5-AG with the formation of 1, 5-anhydro-fructose and H(2)O(2). Measurement was done according to Trinder's reaction principle. The mean within-run and day-to-day precision (CV) of this method for glucose was 0.88% and 1.4%, and also that for 1,5-AG was 1.05% and 1.94%, respectively. The mean recovery rate of two targets was 100.2% and 101.6%, respectively. The correlation (R(2)) between the results of 1,5-AG obtained with our proposed method (y) and those obtained with LanaAG method (x) was 0.999 (y=1.002x-0.675 micromol/l; n=86), and the correlation (R(2)) of glucose between the results obtained with our GK method (y) and those obtained with recommendatory hexokinase method (x) was 0.9999 (y=1.0043x+0.1229 mmol/l; n=86). The reference range (95%) of serological glucose and 1,5-AG was 3.7 to 5.7 mmol/l (4.70+/-0.51 mmol/l) and 83.1 to 240.7 micromol/l (161.9+/-40.2 micromol/l), respectively; and there was no difference with age and sex (P>0.05). This newly developed method was dependable and steady-going, with analysis automatization, and allows quicker and easier measurement of serum glucose and 1,5-AG in one identical reaction cuvette in-phase than previously described methods.
Appl Biochem Biotechnol 2008 Sep
PMID:A novel fully enzymatic method for determining glucose and 1,5-anhydro-D-glucitol in serum of one cuvette. 1833 75

In bone, hydroxyapatite (HA) crystals are deposited onto the type I collagen scaffold by a mechanism that has yet to be elucidated. Bone sialoprotein (BSP) is an acidic phosphoprotein that is expressed at high levels in mineralized tissues, capable of binding type I collagen, and nucleating HA. Both bone-extracted and recombinant BSP (rBSP) bind with equal affinity to collagen. The nature of the BSP-collagen interaction and its role in HA nucleation are not known. We have used a solid-phase binding assay and affinity chromatography to characterize the BSP-collagen interaction. rBSP-binding affinities of triple-helical and fibrillar type I collagen were similar (K(D) approximately 13 nM), while that of heat-denatured type I collagen was lower (K(D) approximately 44 nM), indicating the importance of triple-helical structure in binding BSP. Pepsin treatment of collagen had no effect on rBSP binding, demonstrating that the telopeptides of collagen are not involved. The majority of collagen-bound rBSP was eluted by acetonitrile, indicating that hydrophobic interactions are principally responsible for binding. Using an HA-nucleation assay, it was shown that rBSP is ten-fold more potent in reconstituted fibrillar collagen gels than in agarose gels. Nucleating potency of a non-collagen-binding, HA-nucleating peptide [rBSP(134-206)] showed no difference in the two gel systems. The work here shows that optimal binding of rBSP requires collagen to be in a native, triple-helical structure, does not require the telopeptides, and is stabilized by hydrophobic interactions. Upon binding to collagen, rBSP displays an increase in nucleation potency, implying a co-operative effect of BSP and collagen in mineral formation.
Matrix Biol 2008 Sep
PMID:Bone sialoprotein-collagen interaction promotes hydroxyapatite nucleation. 1862 53

The biological function as well as gene expression of the MRP/GS-X pump is closely linked with cellular GSH metabolism. This article describes two important aspects, i.e., 1) a role of the MRP/GS-X pump in the modulation of cell cycle arrest induced by anticancer prostaglandins; 2) coordinated up-regulation of gamma-glutamylcysteine synthetase gamma-GCS) and MRP1 genes. The A and J series of prostaglandins (PGs) accumulate in the nuclei to suppress the proliferation of cancer cells. Delta(7)-Prostaglandin A(1) (Delta(7)-PGA(1)) methyl ester, a synthetic anticancer PG, increased the mRNA level of the cyclin-dependent kinase inhibitor p21(Sdi1/CIP1/WAF1) in human leukemia HL-60 cells. The induction of p21(Sdi1/CIP1/WAF1) was associated with the accumulation of hypophosphorylated retinoblastoma protein (pRB) and the suppression of c-myc gene expression. Unlike HL-60 cells, cisplatin-resistant HL-60/R-CP cells were insensitive to Delta(7)-PGA(1) methyl ester. While c-myc expression was transiently suppressed, neither G1 arrest nor hypophosphorylation of pRB was observed with the anticancer PG. Plasma membrane vesicles from HL-60/R-CP cells showed an enhanced level of GS-X pump activity toward the glutathione S-conjugate of Delta(7)-PGA(1) methyl ester. GIF-0019, a potent inhibitor of the GS-X pump, dose-dependently enhanced the cellular sensitivity of HL-60/R-CP cells to Delta(7)-PGA(1) methyl ester, resulting in G1 arrest. The GS-X pump is suggested to play a pivotal role in modulating the biological action of the anticancer PG. The expression of MRP1 and gamma-GCS genes can be coordinately up-regulated by cisplatin, 1-[5-(4-amino-2-methyl)pyrimidyl]methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), and heavy metals in human cancer cells. For the up-regulation of these genes, both transcriptional and posttranscriptional regulations are considered to be involved.
Cytotechnology 1998 Sep
PMID:A new aspect on glutathione-associated biological function of MRP/GS-X pump and its gene expression. 1900 85


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