Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3M-KCl extracts of the hepatoma D23 contain antigens that inhibit the complement-dependent cytotoxicity for D23 hepatoma cells of serum from D23 tumour-bearing rats (D23 TBS). Inhibition was not due to a general anticomplementary activity of the extracts. Although a minor part (25%) of the protein of D23-KCl extract was insoluble in PBS, this part contained most of the inhibitory activity. Fractionation of the PBS-soluble material of the extract on Concanavalin A-Sepharose showed that the inhibitory activity did not bind to the lectin. Analysis of D23-KCl extracts on a Sepharose CL-4B column showed that the antigens involved in the cytotoxicity were heterogeneously distributed in the high-mol. wt region (greater than 200,000). Precipitation with 10% trichloroacetic acid (TCA) of D23 KCl extracts revealed that most of the antigenicity was insoluble in TCA. Heating of D23 KCl extracts at 100 degrees C did not affect the antigenicity. Enzyme treatment of D23 extra nuclear membranes (D23 ENP) revealed that the inhibitory activity was not sensitive to proteolytic digestion, while treatment with phospholipase A2, C or D abrogated partly the inhibitory activity. The lipid nature of the antigenicity was indicated by its solubility in organic solvents as chloroform or n-butanol.
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PMID:Tumour-associated antigens reacting with cytotoxic antibodies in serum of hepatoma-bearing rats. 729 8

The bioactivity of feverfew (Tanacetum parthenium) leaf extracts has been analysed, by use of a human polymorphonuclear leukocyte (PMNL) bioassay, to assess the relative contributions of solvent extraction and parthenolide content to the biological potency of the extract. Extracts prepared in acetone-ethanol (system 1) contained significantly more parthenolide (mean +/- s.d. 1.3 +/- 0.2% dry leaf weight) than extracts in chloroform-PBS (phosphate-buffered saline; system 2; 0.1 +/- 0.04% dry leaf weight) or PBS alone (system 3; 0.5 +/- 0.1% dry leaf weight). Extract bioactivity, measured as inhibition of phorbol 12-myristate 13-acetate-induced, 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol)-enhanced PMNL, chemiluminescence, followed a similar trend. Extracts inhibited phorbol 12-myristate 13-acetate-induced oxidative burst by amounts which, if solely attributable to parthenolide, indicated parthenolide concentrations for the respective solvent systems of 2.2 +/- 0.6%, 0.2 +/- 0.1% and 0.9 +/- 0.1% dry leaf weight. The mean ratio of parthenolide concentration to the parthenolide equivalent/PMNL-bioactivity value, for acetone-ethanol and PBS extracts were both 1:1.7. Parthenolide, although a key determinant of biological activity for T. parthenium leaf extracts based on the PMNL-bioassay, seems not to be the sole pharmacologically-active constituent. The identical and elevated bioactivity-parthenolide ratios for both organic and aqueons-phase leaf extracts suggest that a proportion of the other bioactive compounds have solubilities similar to that of parthenolide.
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PMID:Pharmacological activity of feverfew (Tanacetum parthenium (L.) Schultz-Bip.): assessment by inhibition of human polymorphonuclear leukocyte chemiluminescence in-vitro. 917 94

A new method of preparing liposomes containing amphotericin B (AmB) was developed with the purpose of reducing the toxicity of AmB without causing a loss in its antifungal activity. The procedure involved the precipitation of AmB and egg phosphatidylcholine (PC) in phosphate buffered saline (PBS, pH 7.4) or tris buffered saline (TBS, pH 7.4) by evaporating methanol and chloroform, which had been previously mixed in the buffer solution, at 4 degrees C and 600 mm Hg. The in vitro toxicity of the precipitated liposomes containing 3, 6, 9, 12, and 15 wt% AmB was compared with that of the film-swollen liposomes containing the equivalent contents of the drug. The hemolytic ability of the precipitated liposomes at 37 degrees C was 50.3% at maximum of the film-swollen liposomes at a dose of 30 micrograms AmB/ml, as measured after 17-hr incubation. The significant reduction in the hemolysis effect may in fact be attributed to the reduced rate of drug release from the precipitated liposomes. The precipitated liposomes were multilayered and aggregates of AmB were embedded in the bilayers. These aggregates of AmB would be responsible for an intensive positive peak around 330 nm and reduced toxicity. Despite the decrease in toxicity, the activity of the precipitated liposomes against Candida albicans remained almost equipotent to that of the film-swollen liposomes. Therefore, liposomes prepared by the precipitation method are less toxic but equally as active.
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PMID:Hemolytic and antifungal activity of liposome-entrapped amphotericin B prepared by the precipitation method. 955 55

The chloroform extract of Tripterygium wilfordii Hook f (TWH extract) administered into mice daily at doses of 80.0 to 200.0 micrograms/kg (but not 40.0 micrograms/kg) caused suppression of protective immunity to Hymenolepis nana when the extract was injected subcutaneously during the induction phase of protective immunity. Daily administration of 200.0 micrograms/kg TWH extract, during the course of larval development from challenge, also suppressed protective immunity. Inhibition of protective immunity was only observed in mice that received TWH extract for 6 days at a daily dose of 200.0 micrograms/kg and were challenged 24 h after the final injection. TWH extract did not inhibit formation of effector cells that mediate delayed type hypersensitivity (DTH) to H. nana egg antigen when the extract was administered subcutaneously at a dose of 200.0 micrograms/kg/day for 5 days before cell preparation. However, TWH extract did inhibit DTH effector cell activation when cells prepared from infected, PBS-injected mice were transferred into 200.0 micrograms/kg TWH extract-treated recipient mice. These results strongly indicate that TWH extract cannot inhibit the generation of effector cells but will suppress their function in vivo.
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PMID:Suppressive activity of the chloroform extract of Tripterygium wilfordii Hook f on effector T cell activation during Hymenolepis nana infection in mice. 979 70

Human papillomaviruses (HPVs) are major pathogens associated with the development of cancer of the uterine cervix, the most common malignant tumour of women worldwide. Reliable diagnosis of HPV infection, particularly the 'high-risk' types (16/18), may facilitate early identification of 'high-risk' populations for developing cervical cancer and may augment the sensitivity and specificity of primary cervical cancer screening programmes by complementing the conventional Pap test. A simple paper smear method has been developed for dry collection, transport and storage of cervical smears/scrapes at room temperature for subsequent detection of HPV DNA by PCR assay. Imprint biopsies, blood and fine-needle aspirates were also collected by this method. The cervical scrapes or other body fluids were smeared (within 0.5-1 cm diameter) and dried on to sterile small slides made of Whatman 3MM filter paper, and stored individually at room temperature or at 4 degrees C. A small piece (2-3 mm) of the paper smear was punched or cut out with a sterile surgical blade, boiled in an eppendorf tube containing 50 microl of distilled water for 5 min and used directly for PCR amplification. The quality and quantity of DNA derived from paper smears and the results of PCR amplifications for HPV type 16, BRCA1 and p53 genes were identical to those obtained from the same samples following collection in PBS, storage (-70 degrees C) and phenol-chloroform-based DNA extraction. DNA was stable in the paper smears for up to a year, whether stored at room temperature or at 4 degrees C. This method is simple, rapid and cost-effective, and can be effectively employed for large-scale population screening, especially for regions where the specimens are to be transported from distant places to the laboratory.
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PMID:A simple 'paper smear' method for dry collection, transport and storage of cervical cytological specimens for rapid screening of HPV infection by PCR. 1820 98

Liposomes are effectively used in the treatment of microbial infections. Higher cellular uptake has been reported when antibiotics are encapsulated in liposomes. In this study, enrofloxacin (ENF) was encapsulated in large unilamellar vesicles (LUVs) and the effects of formulation variables on the liposome characteristics were investigated. Liposomes were prepared using dry lipid film method. A number of variables such as molar ratios of phospholipid (DPPC; DL-alpha-phosphatidylcholine dipalmitoyl), cholesterol, ENF and amount of alpha-tocopherol and the volumes of internal (chloroform) and external phases [phosphate buffered saline PBS (pH 7.4)] were studied. In vitro characterization of the liposomes including the encapsulation capacity, size and drug release properties were carried out. Using of this method, spherical LUV liposomes with high drug content could be produced. Particle size of liposomes changed between 3.12 and 4.95 microm. The molar ratios of DPPC, cholesterol and ENF affected the size of the liposome (p < 0.05). The drug encapsulation capacities were high and changed between 37.1% and 79.5%. The highest ENF encapsulation was obtained with the highest cholesterol content. An increase in the drug encapsulation capacity of the liposome was found with increasing molar ratios of DPPC, cholesterol and ENF (p < 0.05). Furthermore, the release of ENF from the liposomes decreased as the molar ratios of DPPC, cholesterol and ENF increased (p < 0.05). In conclusion, a convenient colloidal carrier for the controlled release of ENF can be prepared by changing the formulation parameters of LUVs.
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PMID:Encapsulation of enrofloxacin in liposomes I: preparation and in vitro characterization of LUV. 1546 34

Hepatitis C viral chemotherapy suffers from a relatively short half-life of the interferon alpha-2a (IFN alpha). To address this issue, we investigated the effects of polyethylene glycol modification and their subsequent encapsulation in multivesicular liposomes (MVLs), on the release properties of IFN alpha. In the present study, interferon-alpha was conjugated with methoxy-polyethylene glycol (mPEG, MW 5000). Prepared IFN alpha-mPEG5000 conjugate (IFN alpha-mPEG5000) was purified with size exclusion chromatography. The relative in vitro anti-viral activity of pegylated interferon alpha-2a was found to 87.9% of the unmodified IFN alpha. Pegylated IFN alpha encapsulated multivesicular liposomes were prepared by double emulsification technique followed by evaporation of organic solvents from chloroform ether spherules suspended in water. Prepared MVLs were then characterized for shape, size, vesicle count, encapsulation efficiency, and in vitro release rate. In process stability studies of pegylated IFN alpha protein exhibited better stability when exposed to chloroform: diethyl ether (1:1 ratio) mixture as well as variable vortexing time as compared to native IFN alpha. Relatively high percentage of encapsulation of protein ( approximately 75%) was achieved. In vitro release profile of pegylated IFN alpha-mPEG5000 containing MVLs in the PBS showed lower initial burst release with sustained and incomplete release over a period of 1 week. In contrast, native IFN alpha entrapped MVLs were observed as higher initial burst release, i.e., nearly 35% followed by almost complete release. The results confirmed the possibility of multivesicular liposomes as a long-acting or sustained-release delivery system using a combination of pegylation and encapsulation technique for controlled delivery of interferon alpha.
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PMID:Pegylated protein encapsulated multivesicular liposomes: a novel approach for sustained release of interferon alpha. 1688 25

We evaluated the blended compound of DNA/lipid complexes and PLGA (poly(D,L-lactide-co-glycolide)) as a carrier material for drug delivery system (DDS). Transparent, self-standing DNA/lipid/PLGA films were prepared by casting from an organic solvent such as DMSO/chloroform. Daunorubicin hydrochloride (DH) could intercalate and groove bind into DNA in the films, whereby the amount of DH bound to the films was controlled by the latter's immersion period in DH aqueous solution. DH was released from DH films after immersion in PBS solution, whereby release rate was dependent on the chemical structure of lipids. Released DH caused reduction of cell viability during the cell culture of L929 mouse fibroblasts. These results suggested that DNA/lipid/PLGA film was a promising useful material for DDS.
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PMID:Drug binding and releasing characteristics of DNA/lipid/PLGA film. 1820 91

A2E is one of the bis-retinoid pyridinium compounds that accumulate as lipofuscin pigments in retinal pigment epithelial (RPE) cells in association with aging and in some inherited forms of retinal degeneration. Here we observed that 430nm irradiation of A2E in the presence of the spin trap DMPO, led to the appearance of a superoxide dismutase-inhibitable electron paramagnetic resonance (EPR) spectrum characteristic of DMPO-OH; this finding was indicative of hydroxyl radical (OH) formation following initial spin trapping of superoxide anion by DMPO. We also observed an increase in dihydroethidium (HEt) fluorescence and luminol-based chemiluminescence that on the basis of inhibition by superoxide dismutase, was indicative of superoxide anion generation when A2E was irradiated at 430nm in cell-free systems. Nevertheless, while A2E was readily oxidized in the presence of a singlet oxygen generator, superoxide anion did not serve to oxidize A2E. Specifically, by HPLC quantitation and FAB-mass spectroscopy, there was no evidence of A2E oxidation when A2E was incubated with a superoxide anion generator (xanthine/xanthine oxidase) in a variety of solvents (100% PBS, 30% DMSO in PBS, 100% MeOH and CHCl3) or in the presence of detergent. On the other hand, however, peroxy-A2E, an oxidized form of A2E with an endoperoxide moiety on the short-arm of the molecule, readily underwent further oxygen addition when incubated with xanthine/xanthine oxidase. Superoxide anion may be generated by irradiation of A2E but is not involved in the early events that oxidize A2E. Superoxide can contribute to the further oxidation of already-oxidized A2E.
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PMID:Mechanisms involved in A2E oxidation. 1843 97

Biodegradable amino-acid-based poly(ester amide) (PEA) ultra-fine fibers pre-loaded with a nitroxyl radical model compound, 4-amino-2.2.6.6-tetramethylpiperidine-1-oxy (4-amino-TEMPO), were prepared by electrospinning. The fiber size and morphology were shown to be greatly affected by the composition ratio of the solvent mixture (chloroform to DMF) prepared for electrospinning. Nano-size PEA fibers (approx. 640 nm) were obtained when PEA dope was electrospun from the chloroform/DMF solvent mixture at a volume ratio of 2 to 1 vs. 3.5 mum size PEA fibers obtained from chloroform-based electrospun dope. Due to the low glass transition temperature and completely amorphous structures, the PEA electrospun fibrous membranes gradually lost their fiber characteristic during 1 month incubation in PBS buffer at 37 degrees C. The glass transition temperature and heat of fusion of PEA electrospun fibers increased with an increasing incubation time and the most significant change occurred in the first day of incubation in PBS. A sustained release of 4-amino-TEMPO from the electrospun PEA nanofiber membranes was observed over the 1-month incubation period in PBS buffer at 37 degrees C and 38% of the incorporated 4-amino-TEMPO (initial loading level 10 mg/g PEA fibers) was released in one month. During this 1 month incubation in PBS buffer, there were only 1.2% weight loss and 11.7% molecular weight reduction for the electrospun PEA fibrous membranes. In an alpha-chymotrypsin medium (0.1 mg/ml PBS), however, the same electrospun PEA fibrous membranes showed more than 80% weight loss within 6 days and a complete release of encapsulated 4-amino-TEMPO within 5 days.
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PMID:Nitroxyl radical incorporated electrospun biodegradable poly(ester Amide) nanofiber membranes. 1919 60


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