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At least 433 records · Page 24Linked to original sources
PubMed2006

Euphoportlandols A and B, tetracylic diterpene polyesters from Euphorbia portlandica and their anti-MDR effects in cancer cells.

Two new tetracyclic diterpene polyesters, euphoportlandols A (1) and B (2), have been isolated along with 12 known tetracyclic triterpenes from an acetone extract of Euphorbia portlandica. Their structures were established as 5alpha,11alpha,14alpha,17-tetraacetoxy-3beta-benzoyloxy-6beta,15beta-dihydroxy-9-oxoseget-8(12)-ene (1) and 5alpha,11alpha,14alpha,17-tetraacetoxy-3beta-benzoyloxy-6beta,15beta-dihydroxy-9-oxosegetane (2), respectively, by spectroscopic data interpretation. Compounds 1 and 2 were evaluated for their ability to inhibit multidrug resistance in cancer cells. Both compounds were found to be inhibitors of P-glycoprotein activity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Synthesis and characterization of polyester dendrimers from acetoacetate and acrylate.

New aliphatic polyester-type dendrimers were synthesized using a new AB2-type building block 3, prepared from benzyl acetoacetate and 2 equiv of tert-butyl acrylate by acetoacetic acid ester synthesis. The reiterative [deprotection by HCO2H, then EDCI/DMAP coupling] sequence using divergent growth method gave [G1]-4tBu-[G5]-64tBu dendrimers. 13C NMR relaxation time (T1) measurements on the carboxy carbons show that the extended chain conformations are predominant in CDCl3. [structure: see text]

Acetoacetates↗
PubMed2000

Production of polyesters consisting of medium chain length 3-hydroxyalkanoic acids by Pseudomonas mendocina 0806 from various carbon sources.

Pseudomonas mendocina strain 0806 was isolated from oil-contaminated soil and found to produce polyesters consisting of medium chain length 3-hydroxyalkanoates (mclPHAs). The monomers of mclPHAs contained even numbers of carbon atoms, such as 3-hydroxyhexanoate (HHx or C6), 3-hydroxyoctanoate (HO or C8), and/or 3-hydroxydecanoate (HD or C10) as major components when grown on many carbon sources unrelated to their monomeric structures, such as glucose, citric acid, and carbon sources related to their monomeric structures, such as myristic acid, octanoate, or oleic acid. On the other hand, PHA containing both even and odd numbers of hydroxyalkanoates (HA) monomers was synthesized when the strain was grown on tridecanoic acid. The molar ratio of carbon to nitrogen (C/N) had a significant effect on PHA composition: the strain produced PHAs containing 97-99% of HD monomer when grown in a glucose ammonium sulfate medium of C/N<20, and 20% HO, and 80% of the HD monomer when growth was conducted in media containing C/N>40. It was demonstrated that the HO/HD ratio in the polymers remained constant in media with a constant C/N ratio, regardless of the glucose concentration. Up to 3.6 g/L cell dry weight containing 45% of PHAs was produced when the strain was grown for 48 h in a medium containing 20 g/L glucose with a C/N ratio of 40.

Glucose↗
PubMed2003

Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics.

Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth.

Adipates↗
PubMed2003

Polyester-poly(ethylene glycol) nanoparticles loaded with the pure antiestrogen RU 58668: physicochemical and opsonization properties.

PURPOSE: The pure antiestrogen RU58668 (RU) was encapsulated within nanospheres (NS) and nanocapsules (NC) prepared from different polyester copolymers with poly(ethylene glycol) (PEG) chains. The influence of their physicochemical properties on drug release in vitro and their susceptibility to opsonization were evaluated. METHODS: RU-loaded PEG-bearing nanoparticles (NP) prepared by interfacial deposition of preformed polymer were characterized (size, zeta potential, percentage encapsulation and loading). In vitro release kinetics were studied in the presence of 10% fetal calf serum (FCS). Their opsonization in mouse serum was evaluated by silver staining of SDS-PAGE and Western blotting of desorbed proteins. RESULTS: The NS were smaller than NC and had a zeta potential close to zero and a higher percentage of loading. RU release from NS in vitro was reduced as compared with the dissolution profile of free RU in a serum-containing medium. Decreased opsonin adsorption at the surface of pegylated NS was observed. CONCLUSION: Small nanoparticulate systems containing a high load of pure antiestrogen, showing reduced drug release, have been developed. Among the six nanosphere preparations containing RU, two show a size below 200 nm, and two others undergo reduced protein adsorption in the presence of serum, compatible with increased persistence in the blood.

Animals↗
PubMed2003

Surfactant-free, biodegradable nanoparticles for aerosol therapy based on the branched polyesters, DEAPA-PVAL-g-PLGA.

PURPOSE: This study describes the development of surfactant-free, biodegradable nanoparticle systems with varying physicochemical properties and their suitability for pulmonary application via nebulization. METHODS: Nanoparticle suspensions were formulated from the branched polyester, diethylaminopropyl amine-poly(vinyl alcohol)-grafted-poly(lactide-co-glycolide) (DEAPA-PVAL-g-PLGA) alone, as well as with increasing amounts of carboxymethyl cellulose (CMC). Particle size, zeta potential, turbidity, and morphology (atomic force microscopy) were characterized. Three formulations were chosen for further study: Cationic nanoparticles without CMC, cationic nanoparticles with CMC, and anionic nanoparticles with an excess of CMC. Nanoparticle degradation was characterized, as well as stability during nebulization. Nanoparticle-cell interactions were investigated and quantified using confocal laser scanning microscopy and fluorescence spectrometry. RESULTS: Nanoparticles ranged in size from 70-250 nm and displayed zeta potentials of +58.9 to -46.6 mV. Anionic nanoparticles showed the highest stability during nebulization. The degradation rate of each nanoparticle formulation decreased with increasing amounts of CMC. Cell association was highest among cationic nanoparticles (57% and 30%, respectively), although these were not internalized. Despite a lower rate of cell association (3%), anionic nanoparticles were internalized by A549 cells. CONCLUSIONS: Surfactant-free nanoparticles from DEAPA-PVAL-g-PLGA are versatile drug delivery systems; however, only the anionic formulations investigated were proven suitable for aerosol therapy.

Aerosols↗
PubMed2002

Self-assembled oligonucleotide-polyester dendrimers.

A new approach to the controlled synthesis of multicomponent dendrimers is presented, in which three oligonucleotide-dendron conjugates were synthesized using solid phase techniques and hybridized to create a second generation polyester dendrimer with DNA as a core and bearing two types of peripheral functional groups.

Chromatography, High Pressure Liquid↗
PubMed2001

Rabies virus production in non-woven polyester fabric(NWPF) packed-bed reactors.

The production of rabies virus from baby hamster kidney-Ankara66 (BHK-An(66), HUKUK 99050302) monolayer cells was examinedin a packed-bed reactor containing non-woven polyester fabric (NWPF)discs. At first, growth characteristics of the cells were determined instatic culture. The suspension culture studies were realized in a 1litre spinner basket with NWPF support. BHK-An(66) cells(inoculation density, 5x10(4) cells.ml(-1)) were maintained in the reactor loaded with5 g.l(-1) carrier. The culture medium wasEagle's minimal essential medium supplemented with 10% (v/v)fetal bovine serum at 37 degrees C. During the culture, the mediumwas sampled daily to assess glucose and lactate concentrations. At theend of the 7 day culture period the cell density was found to be2.2x10(7) cells.ml(-1), and thereactor was inoculated with 5 ml [1.7x10(6) focus-forming units (ffu).ml(-1)] of the CVS 11(Challenge Virus Standard) strain of rabies virus. After a 72 hincubation period, the cultures were stained with fluorescein-conjugated anti-rabies globulin and were observed using a fluorescencemicroscope. Virus titres determined by the Spearman-Kärber method were 2.2x10(5) ffu.ml(-1). In conclusion, NWPF packedreactors can be considered as a suitable system for the large-scaleproduction of rabies virus.

Animals↗
PubMed1999

Occupational allergic contact dermatitis from unsaturated polyester resin in a car repair putty.

BACKGROUND: Unsaturated polyester (UP) resins are widely used as cements in car repair painting to produce a smooth surface before the final painting. We report two car painters with hand and face dermatitis who were sensitized to a UP resin used for car repair cements. METHODS: Patch testing with commercial substances and ingredients and extracts from UP resins was used to verify the sensitivity. RESULTS: Both patients showed an allergic patch test reaction to a UP resin. They also had an allergic patch test reaction to diethyleneglycol maleate (DEGM), an extract of a UP resin. CONCLUSIONS: Both patients had been patch tested elsewhere with negative results because UP resins had not been used for patch testing. Accordingly, patients with dermatitis who have been exposed to UP resins need to be patch tested with UP resins. The specific chemical causing allergic contact dermatitis in our patients was DEGM.

Automobiles↗
PubMed2002

Removal of T and B lymphocytes by in-line filtration: evaluation of the efficiency of a polyester filter type (Pall WBF-2) by flow cytometric counting.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate whether in-line filtration, using a polyester filter for the preparation of red cell concentrates (RCC) and plasma (PL), leads to an altered proportion of T and B lymphocytes in the fraction of residual white blood cells (WBC). MATERIALS AND METHODS: The capacity of Pall WBF-2 in-line filters to reduce the numbers of T and B lymphocytes from red blood cell concentrates (RCC) and plasma (PL) of 22 donations was investigated by three-colour flow cytometry (FC) using the Tritest-Trucount kit. T and B lymphocytes were identified using monoclonal antibodies (mAbs) against CD3, CD19 and CD45, conjugated with fluorescein isothiocyanate, phycoerythrin or peridinin chlorophyll protein-A, respectively. As the number of B cells was below the detection limit of the FC method, WBC of the respective blood components of healthy donors were concentrated 25-fold by Percoll density-gradient centrifugation. In this fraction the absolute numbers of T and B cells, as well as their ratio, were determined using the Attractor software, which provides a discrimination of rare cell counts from FC in relation to debris. RESULTS: The mean numbers, as well as minima and maxima of T and B lymphocytes per unit, were as follows. T cells in RCC: 4.51 x 10(3) (1.68 x 10(2)-4.09 x 10(4)) and in PL: 1.35 x 10(3) (2.21-1.78 x 10(4)); B cells in RCC: 2.33 x 10(3) (7.10 x 10(1)-9.15 x 10(3)) and in PL: 2.33 x 102 (7.5 x 10(2)-2.8 x 10(3)). T cells were retained, on average, at a higher level than B cells: 3.01 times higher in RCC and 1.01 times higher in PL. CONCLUSION: After filtration, the ratio of T and B lymphocytes changed in RCC (1.95 : 1) compared with unfiltered blood, where it was 5.83 : 1. In PL the ratio did not change notably compared to unfiltered blood. The results of this research show that cell concentration (using gradient centrifugation) in combination with an appropriate FC acquisition and analysis procedure, allows both residual T and B lymphocytes (being under the detection limit without cell concentration) to be determined.

B-Lymphocytes↗
PubMed2003

Successful treatment of ulcerative colitis with leukocytapheresis using non-woven polyester filter.

Ulcerative colitis is a chronic inflammatory disease of the rectum and colon. Although the pathogenesis of ulcerative colitis is not fully elucidated, cell-mediated immunity plays an important role in disease pathogenesis. Leukocytapheresis is a newly emerging therapy to eliminate activated leukocyte from systemic circulation. We have studied the effects of leukocytapheresis on patients with ulcerative colitis who had failed to respond to conventional therapy. A total of 51 patients with ulcerative colitis were treated with apheresis using a non-woven polyester fiber filter (Finecell, Asahi Medical Co.,Tokyo, Japan) originally developed as a microcoagulation elimination filter for massive transfusion. Of the 51 patients, 33 (64.7%) achieved clinical remission manifested by clinical activity and colonoscopic findings without any adverse effects. This result suggested that leukocytapheresis using Finecell might serve as an alternative therapy for ulcerative colitis as other leukocytapheresis using centrifugation or column.

Adolescent↗
PubMed1991

Histologic and immunohistochemical studies on the preparation of white cell-poor red cell concentrates: the filtration process using three different polyester filters.

Three third-generation white cell (WBC)-depletion filters based on polyester layers with decreasing pore size were investigated. In the coarse layers, unaggregated granulocytes, monocytes, and platelets and aggregates of these cells were captured in close contact with the fibers. This indicates that the depletion of granulocytes, monocytes, and platelets in the coarse layers of the filters is due in part to activation and adhesion with the formation of cell clusters on the fibers. In Filter I and Filter II platelets were not found in the fine layers, whereas in Filter III, 70 percent of the platelets were detected as unaggregated platelets on the fibers of the fine layers. More than 95 percent of the lymphocytes captured in the three filters occurred as single cells in the fine layers, and over 60 percent of these could be recovered. This suggests that the depletion of lymphocytes depended on trapping of the cells in the fiber network. All three filters captured HLA-DR-positive lymphocytes in the top layers, a finding that supports earlier reports that the transfusion of filtered red cell concentrates reduces HLA alloimmunization. More lymphocytes and granulocytes were found in the last layer of Filters II and III than of Filter I. Therefore, the risk of white cell leakage is probably lowest for Filter I. Red cells were found as red cell aggregates in the fine layers of Filters I and II, whereas almost no red cells were detected in Filter III. It was shown that the three filters studied were similar in their removal of WBCs, but differed in their mechanisms of removal.

Blood Platelets↗
PubMed1992

Prevention of growth of Yersinia enterocolitica in blood by polyester fiber filtration.

The ability of polyester white cell-reduction blood filters to prevent the growth of Yersinia enterocolitica in units of donated blood was studied. Sixteen units of freshly drawn blood were inoculated with 10, 50, 100, or 150 colony-forming units (CFU) per mL of a clinical isolate of Y. enterocolitica (serotype O:3). The units were subsequently fractionated into red cell concentrate and resuspended in AS-1 or AS-3 solution. One-half of the red cell concentrates in each solution were filtered within 15 hours of phlebotomy and stored for 42 days. The remaining units served as unfiltered controls. Bacterial growth was monitored by weekly cultures and, on the last storage day, by the presence of endotoxin and the formation of methemoglobin. One hundred twelve primary cultures (560 plates) were performed. Units collected in AS-1 and filtered remained sterile when initially inoculated with 50 CFU or less. Filtered units spiked with 100 CFU or less and collected in AS-3 remained sterile throughout their shelf life. All unfiltered units supported bacterial growth and the formation of endotoxin and methemoglobin. The filtration of freshly donated blood proves to limit the growth of Y. enterocolitica in red cell components.

Blood Gas Analysis↗
PubMed2004

Euphopubescenol and euphopubescene, two new jatrophane polyesters, and lathyrane-type diterpenes from Euphorbia pubescens.

The structures of euphopubescenol and euphopubescene, two new macrocyclic jatrophane diterpene polyesters, isolated from the whole dried plant of Euphorbia pubescens, were established as 5alpha,8alpha,15beta-triacetoxy-3alpha-benzoyloxy -4alpha-hydroxy -9,14-dioxo-13beta H-jatropha-6(17),11 E-diene ( 1) and 3beta,7beta,8beta,9alpha,14alpha,15beta-hexaacetoxy-2beta H-jatropha-5 E,11 E-diene ( 2) by 1D- and 2D-NMR (COSY, HMQC, HMBC and NOESY), IR, EI-MS and EI-FTICR-MS. Two known lathyrane derivatives, jolkinol A ( 3) and jolkinol A ( 4), whose (13)C-NMR spectra were assigned, were also isolated. Compounds 1 - 3 have been evaluated for their ability to inhibit the in vitro growth of three human tumour cell lines representing different tumour types, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer). They inhibited both MCF-7 and NCI-H460 cell lines, with GI50 values ranging between 40.9 microM and 95.3 microM, but were found to be ineffective as growth inhibitors of the SF-268 cell line.

Antineoplastic Agents, Phytogenic↗
PubMed1983

Dibutyryl cAMP-inducible alkaline phosphatase in animal cell plasma membranes: fluorescence detection of mutant clones on polyester cloth.

We have developed a rapid screening assay that allows us to estimate the alkaline phosphatase content of mouse L-M cell colonies immobilized on polyester cloth. This permitted the identification and isolation of two mutant clones with increased constitutive alkaline phosphatase activity and six clones that fail to express this activity when treated with dibutyryl cyclic AMP. Both of the strains with increased constitutive activity have basal enzymatic activities that are 6- to 7-fold higher than the activity of the parental strain. The extents to which the cyclic nucleotide further induces alkaline phosphatase in these two strains are different, however, indicating that they represent two classes of mutants. Studies using amino acids and synthetic peptides as alkaline phosphatase inhibitors suggest that only one alkaline phosphatase isoenzyme predominates, in both the parental and the mutant cell lines, with or without induction by cyclic nucleotide. Comparison to mouse tissues indicates that our cell lines express an isozyme resembling that found in kidney and bone. The six clones that fail to express alkaline phosphatase activity when treated with dibutyryl cyclic AMP also have extremely low basal levels of the enzyme. All of these mutant strains continue to synthesize protein when treated with dibutyryl cyclic AMP and undergo growth cessation and morphological changes in the presence of this agent. Thus, the mutations all appear to affect factors specific to the expression of alkaline phosphatase activity rather than factors that affect general cellular responsiveness or permeability to dibutyryl cyclic AMP. The characterization of these strains may help elucidate mechanisms of eukaryotic membrane protein biogenesis, enzyme induction, and regulation of gene expression by cyclic nucleotides.

Alkaline Phosphatase↗
PubMed2004

Preparation of hydrogel hollow particles for cell encapsulation by a method of polyester core degradation.

Implantation of encapsulated cells in particles of less than 1 mm (micro-encapsulation) has been proposed as a cell synthesized bio-molecule delivery system. Encapsulation provides immuno-isolation, protecting foreign cells from host immune system while nutrients, oxygen and therapeutic products can diffuse freely across capsule walls. A new method is described for the synthesis of a new family of hollow microparticles for cell encapsulation. Unlike other micro-encapsulation methods, encapsulation in those devices will take place after capsule synthesis, by micro-injection. The microcapsules were prepared by a three-steps original procedure: first, synthesis of a core particle, followed by coating with a layer of epichlorohydrin cross-linked amylo-pectin gel and, finally, selective degradation of the core particle to create the cavity. Initial experiments make use of amylo-pectin cross-linked with trimetaphosphate as core particle material. However, selective degradation was difficult to achieve. In further essays, polyesters were used successfully for the preparation of core particles. Optimizations were carried out and the permeability and morphology of the hollow particles were investigated. The preliminary results show that the new method has the potential to become a standard procedure to obtain hydrogel hollow particles. Moreover, the permeability study seems to be in accordance with specifications for immuno-isolation.

Cell Transplantation↗
PubMed2004

The effect of solar irradiation on the fading of nylon and polyester fabrics dyed with selected disperse dyestuffs on radiant energy basis.

Solar total, UVA and UVB irradiances were measured separately using three kinds of wavelength band detectors in Tokyo, Japan in November 1999. Characteristics of diurnal variations were examined: Total irradiance reached a maximum value of about 600 W m(-2) at around noon. The variation pattern of UVA irradiance was observed to be similar to the total irradiance. The energy level was about 4.65% of total irradiance. Diurnal variation of UVB was in the form of a steeper bell curve due to the absorption in the air mass. UVB energy to solar total irradiance was about 0.07%. Photodegradation characteristics of two disperse dyestuffs were investigated on the basis of solar radiant energy. A UVA fluorescent lamp was applied to examine the fading characteristics to find the wavelength dependency. As a result, nylon dyeings were less lightfast by a factor of about 6 and 13 for C I Disperse Blue 27 and C I Disperse Blue 165, respectively, compared with polyester on the radiant energy basis. Visible light, as well as UVA, radiation contribute to fading of C I Disperse Blue 165 whereas UVA mostly cause the fading of C I Disperse Blue 27.

Coloring Agents↗