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1.
Human alpha-fetoprotein was isolated from abortive material with the help of affinity chromatography on immobilized estrogens. After butanol extraction from the abortive material human AFP obtained the ability for affinity binding with immobilized estrogens. The addition of estrogens to the extract of isolated AFP preparation and incubation with them did not lower AFP binding with immobilized estrogens during the experiments, using affinity chromatography. A 10% buffered aqueous butanol solution was most optimal for elution. The data obtained can suggest that AFP in biological fluids is bound to estrogens, and butanol extraction deestrogenizes human AFP. The mechanism of AFP binding to estrogens in vivo is, evidently, carried out with the help of specific unknown carrier, as AFP does not bind free estrogens.  相似文献   

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The use of 17 beta-estradiol-17-hemisuccinate coupled to agarose beads is shown to be a rapid and simple procedure for the isolation of alpha-fetoprotein (AFP) from amniotic fluid. The elution profile of the affinity column shows that AFP is sufficiently retarded by the gel to perform the purification of the protein without specific elution with high-affinity AFP ligands. Rat AFP appeared as a single symmetric peak, a profile that is in good agreement with the existence of a single population of AFP molecules having estrogen-binding properties.  相似文献   

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Benzoyl chloride and 53 commercially available aromatic, heterocyclic and aliphatic nitro compounds were tested for mutagenicity in Salmonella typhimurium TA98 and TA100. 34 of 53 nitro compounds (64%) were mutagenic, 4 in TA100 only, 15 in TA98 only, and 15 in both strains. 13 of the heterocyclic derivatives of pyridine, indole, indazole, quinoline, and benzimidazole were mutagenic. 21 of 34 mutagenic nitro compounds were bactericidal. Nitromethane was the only aliphatic tested and was not mutagenic. Benzoyl chloride, a human carcinogen, was mutagenic for TA98.  相似文献   

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Benzoyl chloride and 53 commercially available aromatic heterocyclic and aliphatic nitro compounds were tested for mutagenicity in Salmonella typhimurium TA98 and TA100. 34 of 53 nitro compounds (64%) were mutagenic, 4 in TA100 only, 15 in TA98 only, and 15 in both strains. 13 of the heterocyclic derivatives of pyridine, indole, indazole, quinoline, and benzimidazole were mutagenic. 21 of 34 mutagenic nitro compounds were bactericidal. Nitromethane was the only aliphatic tested and was not mutagenic. Benzoyl chloride, a human carcinogen, was mutagenic for TA98.  相似文献   

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A commercially available assay for aldosterone that requires no extraction was found to be valid without modification for rat serum. The assay was performed in duplicate on as little as 0.5 cc of rat serum and gave linear results from 5 ng/dl to 500 ng/dl, (i.e., the physiological range of the rat). Samples above 150 ng/dl had to be diluted in this assay. The cost per sample if performed in duplicate and in batches was approximately one dollar. We found that this assay, which was developed for and is marketed for determining aldosterone concentration in human samples, offered a cost effective assay for aldosterone determination in the rat.  相似文献   

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The mineralization of nitrogen from citric acid waste mycelium (Aspergillus niger) and Pruteen (Methylophilus methylotrophus), and nitrogen and sulphur mineralization from keratin (feather meal) have been studied in a fertile loam soil. Ammonium nitrogen was rapidly released from the organic nitrogen sources and was subsequently nitrified. Sulphate release from feather meal was also demonstrated. Both the advantages and disadvantages of using these commercially available forms of microbial biomass and keratin as fertilizers are discussed.  相似文献   

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Alpha-fetoproteins (AFP) from amniotic fluid of mouse and rat demonstrate high affinity and specificity during their binding with immobilized diethylstilbestrol, which allows to isolate these two proteins by one step using the method of affinity chromatography on Sepharose with immobilized diethylstilbestrol. Meanwhile the yield of mouse AFP was 42%, and rat AFP--75%. The preliminary incubation of the amniotic fluid of rat and mouse with free estradiol results in abrupt fall of AFP outcome, which may testify to the binding of estradiol and diethylstilbestrol by the same receptor sites on AFP molecule.  相似文献   

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Long L  Davidson JN  Spear BT 《Genomics》2004,83(4):694-705
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The preservation efficiency of eight brands of antacid suspensions currently marketed in Jordan was tested against Pseudomonas aeruginosa (ATCC 9027). Results shown indicate that the preservation equilibria of these preparations have drastically changed with repeated challenges from microbicidal to microbiostatic and then to absence of preservation.  相似文献   

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Aims: Commercially available selective media for methicillin‐resistant Staphylococcus aureus (MRSA) were tested for the detection and isolation of methicillin‐resistant Staphylococcus pseudintermedius (MRSP). Methods and Results: Five different screening agars [mannitol salt agar with oxacillin and BD BBL? Chromagar? MRSA (BD Diagnostics); chromID? MRSA agar (bioMérieux); Oxacillin resistance screening agar base (ORSAB); and Brilliance MRSA agar (Oxoid)] were analysed for the detection of MRSP. Bacteria that may be isolated together with MRSP and may grow on the screening agars were included in the study to determine possible interference with the growth of MRSP. MRSP grew well on all selective media except on BD BBL? Chromagar? MRSA (BD Diagnostics) and chromID? MRSA agar (bioMérieux), on which a low to moderate growth rate was noted. Conclusions: ORSAB (Oxoid) and Brilliance MRSA agar (Oxoid) are most suitable for the detection and isolation of MRSP from clinical material. Significance and Impact of the Study: The importance of MRSP in veterinary medicine is increasing. Diagnostic systems are needed to detect MRSP carrier as soon as possible. This study provides information about selected MRSA screening agars for the detection of MRSP to the clinical microbiologists.  相似文献   

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Antibody array analysis of complex samples requires capture reagents with exceptional specificity. The frequency of antibodies with label-based detection may be as low as 5%. Here, however, we show that as many as 25% of commercially available antibodies are useful when biotinylated cellular proteins are fractionated by size exclusion chromatography (SEC) first. A microsphere multiplex with 1725 antibodies to cellular proteins was added to 24 SEC fractions, labelled with streptavidin and analyzed by flow cytometry (microsphere-based affinity proteomics, MAP) The SEC-MAP approach resolved different targets captured by each antibody as reactivity peaks across the separation range of the SEC column (10-670kDa). Complex reactivity profiles demonstrated that most antibodies bound more than one target. However, specific binding was readily detected as reactivity peaks common for different antibodies to the same protein. We optimized sample preparation and found that amine-reactive biotin rarely inhibited antibody binding when the biotin to lysine ratio was kept below 1:1 during labelling. Moreover, several epitopes that were inaccessible to antibodies in native proteins were unmasked after heat denaturation with 0.1% of SDS. The SEC-MAP format should allow researchers to build multiplexed assays with antibodies purchased for use in e.g. Western blotting.  相似文献   

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An acid phosphatase species which was activated by Fe2+ was determined to be partially soluble but mainly particulate in rat spleen. The particulate enzyme could be extracted into 1 M KCl. This enzyme bound to Cibacron Blue-immobilized Sepharose (Blue-Sepharose) and was desorbed by 2 M KCl with a good yield, while the other acid phosphatases in rat spleen did not adsorb on Blue-Sepharose. The enzymes eluted on Blue-Sepharose chromatography of both the soluble and particulate fractions were electrophoretically identical. The enzyme hydrolyzed aryl monophosphates, phosphoproteins, and nucleoside di- and triphosphates. The activity for the three kinds of substrate was similarly activated by Fe2+, ascorbic acid and cysteine, and inhibited by molybdate, Cu2+ and F-. Cibacron Blue inhibited the enzyme competitively with respect to a substrate, p-nitrophenyl phosphate, but kinetic analysis suggested that more than one dye molecule binds to the enzyme. The Blue-Sepharose technique could be applied not only to quantitative separation of acid phosphatases similar to the spleen enzyme from bone and epidermis of rat, but also to that of a tartrate-resistant acid phosphatase from human spleen with Gaucher's disease.  相似文献   

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A specific alpha-fetoprotein (AFP) gene binding nuclear protein (Mol. Wt. 149,000) was determined in Morris hepatoma 7777 cells by the protein blotting technique. This protein is not present in normal adult rat liver and non-AFP producing Morris hepatoma 5123tc. Neoplasia induced in rats fed the hepatocarcinogen 3'-methyl-4-dimethylaminoazobenzine enhanced AFP gene activity and re-expressed specific AFP gene binding nuclear protein. The precise role of this protein in AFP gene regulation remains to be determined.  相似文献   

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An automated and rapid method for quantifying malondialdehyde (MDA) in breath condensate was developed and validated. The method is based on derivatisation with thiobarbituric acid, HPLC separation and fluorescence detection and is optimised for determination of MDA in breath condensate. Sample collection is non-invasive and simple. The detection limit (4.1 nM) is low, precision is good and the analysis time is short. The response is linear in the concentration range of 0.020 to 1.0 microM. Samples could be stored for 1 month at -20 degrees C and for 3 months at -80 degrees C without losses. Using this method, there was no statistically significant difference between patients with asthma and patients without asthma. However, among females, subjects with asthma had higher MDA levels as compared to females without asthma (0.17 vs. 0.12 pmol/s, p=0.04). The use of the method when studying airway inflammation has to be further evaluated.  相似文献   

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