bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular cloning of gaf2, A schizosaccharomyces pombe GATA factor, which has two zinc‐finger sequences
Authors: Hoe Kwang‐Lae , Won Mi‐Sun , Yoo Ook‐Joon , Yoo Hyang‐Sook 
Published: July 2007

AbstractBy low stringency screening of a λ‐Shizosaccharomyces pombe genomic library, we have cloned a GATA factor homologous gene, gaf2+, within a 3.1‐kb EcoRI fragment. The gaf2 ORF predicts a protein of Mr 61 kDa consisting of intronless 564 amino acids corresponding to 1,692 bp. Gaf2 has two zinc‐fingers as Urbs1 of Ustilago maydis, whereas most of fungal GATA factors have only one zinc‐finger. The separation between two zinc‐fingers of Gaf2 is rather long. In addition to gaf2, the sequence analysis revealed a Val‐tRNA gene in the 3′‐flanking region of gaf2. Northern blot analysis indicated that the gaf2 gene is transcribed constitutively irrespective of the nitrogen source in a medium.
A comparative study of the binding characteristics of ceftriaxone, cefoperazone and cefsudolin to human serum albumin
Authors: Nerli Bibiana , Farruggia Beatriz , Picó Guillermo 
Published: July 2007

AbstractThe binding to human serum albumin of three cephalosporins of pharmacological interest: cefoperazone, ceftriaxone and cefsulodin was studied by ultrafiltration and differential scanning calorimetry methods. The identification of the binding sites in albumin was also performed using probes for the so‐called sites I, II, bilirubin and fatty acids binding sites. Albumin showed two types of binding sites for cefoperazone and ceftriaxone, while for cefsulodin it showed a single type of binding site. The affinity values were: 5.6 104 M‐1 and 3.1 104 M‐1 for cefoperazone and ceftriaxone respectively, while cefsulodin showed low affinity (3.8 102 M‐1). It was found that only cefoperazone interacted in a slight way with site I on serum albumin, while site II and the bilirubin binding site have capacity of binding the three cephalosporins assayed. Ceftriaxone and cefoperazone showed capacity to bind to the fatty acids binding site on albumin. These cephalosporins increased the thermal stability of the protein, suggesting that these ligands are favouring the compact structure of the native form of the protein more than the unfolded form.
A novel method for purification of catalytic antibodies toward DNA from sera of patients with lymphoproliferative diseases
Authors: Kozyr A. V. 
Published: July 2007

AbstractA novel highly efficient method of purification of DNA‐hydrolyzing antibodies from sera of patients with lymphoproliferative diseases was developed. The method suggests purification of serum sample using Cibacron Blue 3GA, ion exchange chromatography on DEAE‐Sepharose FF, PrG affinity chromatography and selection of the DNA‐binding fraction on DNA‐Sephacryl. The application of the method allows to obtain the stable and active polyclonal preparation with increased content of DNA‐hydrolyzing antibodies characterized by specific binding constant determined using heteropolymeric oligonucleotide substrate. The unusual properties of anti‐DNA catalytic antibodies in respect to their interactions with DEAE ion exchanger are discussed.
Binding properties of human immunodeficiency virus type‐2 (HIV‐2) rna corresponding to the packaging signal to its nucleocapsid protein
Authors: Tsukahara Tomonori , Komatsu Hiroyoshi , Kubo Makoto , Obata Fumiya , Tozawa Hideki 
Published: July 2007

AbstractThe nucleocapsid (NC) protein of human immunodeficiency virus type‐1 (HIV‐1) contains two zinc finger motifs (ZFMs), and binds specifically to the packaging signal which is located in the 5′ leader sequence of the viral genomic RNA between the first splice donor and the gag initiator codon (AUG). In this study, we analyzed the specificity of the binding of the corresponding region of HIV‐2 (Region 3) to its NC protein (NCp8), by performing a competitive ultraviolet (UV) cross‐linking assay using in vitro‐synthesized 32P‐labeled and unlabeled RNAs corresponding to a sequence between the primer binding site and the gag AUG (Region 1). Binding of 32P‐labeled Region 1 RNA to NCp8 was inhibited specifically by adding unlabeled Region 1 and 3 RNAs and no specific binding was detected using deletion mutant peptides of NCp8. These findings suggest that the region(s) which bind(s) specifically to HIV‐2 NCp8 lie(s) between the first splice donor and the gag AUG in the 5′ leader sequence and that NCp8 is the minimum binding region responsible for the specific binding of the region downstream of the first splice donor site of HIV‐2 RNA.
Effects of metabolic inhibitors and lectins on the menadione‐dependent generation of H2O2 by rat thymocytes
Authors: Timoshenko A. V. , Loiko E. N. , Cherenkevich S. N. , Gabius H. ‐J. 
Published: July 2007

AbstractThe capacity of oxidative metabolism and its regulation is an important factor in disease control. Using scopoletin as a fluorescent substrate of peroxidase the extent of menadione‐dependent production of H2O2 by rat thymocytes was determined. The reaction was inhibited by 2,4‐dinitrophenol, papaverine, nordihydroguaiaretic acid and iodacetamide. The membrane‐penetrating SH reagent N‐ethylmaleimide primed the reaction, probably due to an inhibition of glutathione peroxidase. To delineate an influence of cell‐surface protein‐carbohydrate interactions by exogenous lectins, the impact of cell binding was analyzed for several plant lectins, namely concanavalin A, phytohemagglutinin, the lectins from Triticum vulgaris and from Sambucus nigra. Except for the α‐NeuNAc(2‐6)gal/galNAc‐binding agglutinin, the other three plant proteins with specificities to different parts of N‐linked oligosaccharides primed the reaction. This activity of lectins did not coincide with their ability to aggregate cells. The given results indicate that biosignaling pathways triggered by lectins are involved in the regulation of the intracellular reduction of menadione.
Inactivation of aconitase in yeast exposed to oxidative stress
Authors: Murakami Keiko , Yoshino Masataka 
Published: July 2007

AbstractInactivation of aconitase by oxidative stress was analyzed under the in vivo and in situ conditions of yeast cells. Treatment of yeast cells with paraquat caused a specific inactivation of aconitase without affecting the activity of other citric acid cycle enzymes. Addition of copper plus ascorbic acid to permeabilized yeast cells also inactivated aconitase, but did not affect other TCA cycle‐related enzymes. Inactivation of aconitase was suggested to be due to the superoxide and hydroxyl radicals produced from the reaction of 02 with paraquat and by Fenton reaction with copper and ascorbic acid under the in vivo and in situ conditons of yeast, respectively. Citrate the substrate of aconitase effectively protected aconitase from the oxidative inactivation. Toxicity of oxygen to yeast cells can be explained by the specific inactivation of aconitase by oxygen radicals. Increased concentrations of citrate can act as a defense mechanism against oxidative inactivation of aconitase under the exposure of aerobically grown yeast to oxidative stress.
Endogenous superoxide‐like species and antioxidant activity in ocular tissues detected by luminol luminescence
Authors: Trevithick John R. , Dzialoszynski Tomasz 
Published: July 2007

AbstractA new luminescent method was used to detect the reactive oxygen species in aqueous and vitreous humors and in homogenates of the lens and retina of laboratory rats. Superoxide‐like activity per μg protein increased in all tissues with weight of the rat, a good indicator of animal age. Superoxide dismutase, centrophenoxine, soluble vitamin E (D‐α‐tocopherol (polyethlyene glycol 1000) succinate, and N′‐diphenyl‐p‐phenylenediamine (DPPD) reduced the luminescence. Catalase had no effect. These results are consistent with the detected species being superoxide‐like.
Hydroxyl and superoxide anion radical scavenging activities of natural source antioxidants using the computerized JES‐FR30 ESR spectrometer system
Authors: Noda Yasuko , Anzai Kazunori , Mori Akitane , Kohno Masahiro , Shinmei Masashi , Packer Lester 
Published: July 2007

AbstractFree radical scavenging activities of water‐soluble extracts from some natural sources, health foods, and antioxidant substances were measured using the JES‐FR30 JEOL spectrometer. The objective was to develop a standardized method whereby comparison could be made between the radical scavenging activities of complex mixtures.Scavenging of hydroxyl radical was determined using DMPO. Activity was calibrated using a standard material, L‐ascorbic acid 2‐[3,4‐dihydro‐2,5,7,8‐tetramethyl‐2‐ (4,8,12‐trimethyltridecyl)‐2H‐1‐benzopyran‐6yl‐hydrogen phosphate] potassium salt (EPC‐K1), an analog of vitamin C and vitamin E which is water soluble and stable at room temperature. The order of greatest hydroxyl radical scavenging activity was green tea extract, pine bark extract (Pycnogenol), Ginkgo Biloba extract (EGb 761), a flavonoid blend of several fruit and vegetable extracts (GNLD), and Bio‐Normalizer (Sun‐O Corp). Activity was determined after treatment of samples with ascorbic acid oxidase. This treatment revealed the presence of ascorbate in some natural extracts and commercial preparations. The pine bark extract was the most heat resistant and had ascorbate‐like activity in the preparations.Scavenging of superoxide anion was determined using the spin trap, 5,5‐dimethyl‐1‐pyrroline‐N‐oxide (DMPO), and analyzed by comparison with a standard curve made with superoxide dismutase. Comparison of the water solubilized components of natural source antioxidants showed that filtrates fractionated using centrifuge type Millipore filter tubes (M.W.<100,000; M.W.<10,000) also had almost the same SOD‐like activity. Samples were also treated with ascorbate oxidase or by heating (100δC for 10min). The order of activity, from greatest to least, was Ginkgo biloba extract EGb 761, pycnogenol, β‐catechin, tea and BioNormalizer.
Expression of soluble, active human macrophage colony stimulating factor in Escherichia coli
Authors: Jiang Xueyuan , Zhou Aiwu , Cen Bo , Qiu Qifeng , Dong Xueyin , Xu Xianxiu 
Published: July 2007

AbstractHuman macrophage colony stimulating factor (M‐CSF) has been successfully overexpressed in Escherichia coli AD494 (DE3) with an expression level of approximate 26 % of the total cellular proteins. The truncated human M‐CSF gene encoding the amino‐terminal 149 amino acids was subcloned into the prokaryotic expression vector pET11d under the control of the inducible T7 promoter. Nearly 40 % of the recombinant protein was in the soluble fraction which showed obvious stimulating effects on mouse macrophage colony formation and had an M‐CSF specific activity of ≈︁1×106 units/mg soluble protein.
Expression of bone morphogenetic proteins of human neoplastic epithelial cells
Authors: Hatakeyama Setsuko , Gao Yu‐Hao , Ohara‐Nemoto Yuko , Kataoka Hiroaki , Satoh Masanobu 
Published: July 2007

AbstractBone morphogenetic proteins (BMPs) are crucial factors of osteogenesis. We investigated the expressions of BMP subtypes in human salivary adenocarcinoma cell line (HSG‐S8), tongue squamous cell (HSC‐4) and gingival squamous cell (Ca9‐22) carcinoma cell lines, gastric poorly differentiated adenocacinoma cell (MNK45) and signet ring cell (KATOIII) carcinoma cell lines, rectal adenocarcinoma (RCM‐1, RCM‐2, and RCM‐3), and thyroid (8505C) and bladder (T24) carcinoma cell lines by reverse transcription‐polymerase chain reaction (RT‐PCR). RT‐PCR disclosed that BMP‐1 was expressed in all cell lines examined, and BMP‐2 was amplified in almost all cells except MKN45. Two squamous cell carcinomas, HSC‐4 and Ca9‐22, and KATOIII expressed only BMP‐1 and BMP‐2. MKN45 did not express BMP‐2, but expressed BMP‐7 and weakly BMP‐4 and BMP‐5. In addition to the expression of BMP‐1 and BMP‐2, three rectal adenocarcinoma cell lines commonly expressed BMP‐7, and HSG‐S8 expressed BMP‐6. These findings indicated that the neoplastic epithelial cells possessed a rather great potency to express BMP mRNAs. On the other hand, among these carcinoma cells, HSG‐S8 solely induced bone in nude mouse tumors, and HSC‐4 and KATOIII contained many calcified masses in tumors while the rest did not induce either.
Regulation of androgen receptor (AR) and prostate specific antigen (PSA) expression in the androgen‐responsive human prostate LNCaP cells by ethanolic extracts of the Chinese herbal preparation, PC‐SPES
Authors: Hsieh Tze‐chen , Chen Sophie S. , Wang Xuhui , Wu Joseph M. 
Published: July 2007

AbstractAs part of the study on the potential use of natural product‐based combination therapy for treating prostate cancer, we have investigated the effects of a “HPLC standardized” herbal preparation, PC‐SPES, on the prostate LNCaP cell line. Proliferation of the LNCaP cells was inhibited by a 4‐6 day incubation with ethanolic extracts of PC‐SPES. Decrease of cell growth was accompanied by a 60‐70 % down‐regulation of the proliferating cell nuclear antigen (PCNA) and level of secreted PSA. A smaller and more variable decrease (20‐40%) in the level of intracellular PSA was also observed. The PC‐SPES‐modulated PSA changes occurred concurrently with the decrease of AR expression, based on Western blot analysis and binding to the radioactive ligand [3H]R1881. A 60% decrease in R1881 binding occurred after a 24 h incubation with PC‐SPES. These results suggest that PC‐SPES negatively affects cell growth in part through its ability to modulate changes in PCNA, and may decrease PSA levels indirectly by suppressing AR expression.
Inhibition of glycohydrolase enzymes by aqueous extracts of Chinese medicinal herbs in a microplate format
Authors: Collins R. A. , Ng T. B. , Fong W. P. , Wan C. C. , Yeung H. W. 
Published: July 2007

AbstractA microplate assay, for use with a variety of glycohydrolase enzymes, was developed to aid the screening of Chinese medicinal herb extracts for the presence of potential anti‐viral and anti‐lymphoma compounds. The microplate assay method described offers greater convenience, speed and reproducibility over existing methods. The enzymes tested were α‐glucosidase, β‐glucosidase and β‐glucuronidase. The assay can be easily adapted for use with other glycohydrolase enzymes. Of the 12 herb extracts examined four did not inhibit any of the enzymes (<50% inhibition), one inhibited α‐glucosidase only (>50% inhibition), six inhibited β‐glucuronidase only, and one inhibited both α‐glucosidase and β‐glucuronidase. None of the extracts were capable of inhibiting β‐glucosidase to any significant extent.
Carbohydrate moeity of Plasmodium falciparum glycoproteins: The nature of the carbohydrate‐peptide linkage in the MSP‐2 glycoprotein
Authors: Khan Abbas H. , Qazi Aamir M. , Hoessli Daniel C. , Torred‐Duarte Armida P. , Senaldi Giorgio , Qazi Mahmood H. , Walker‐Nasir Evelyne 
Published: July 2007

AbstractMetabolic labelling of Plasmodium falciparum parasites with [3H]GIcN, [3H]Man, [3H]Gal and [3H]ethanolamine, and subsequent purification by SDS‐PAGE of the labelled material provided effective labelling of the MSP‐1, 195 kDa, and MSP‐2, 42‐53 kDa, glycoproteins. Reductive β‐elimination of the MSP‐2 released from the gel consisted of glycopeptides containing labelled sugars. Processing of the eliminated components and identification of the sugar residues demonstrated the presence of N‐acetylglucosaminitol and N‐acetylgalactosaminitol amongst other labelled sugars. Reductive β‐elimination with sodium hydroxide‐sodium borotritide‐borohydride showed the presence of glucosaminitol and alanine in the hydrolysis products. The MSP‐2 was retained on solid phase wheat‐germ agglutinin and was released from the lectin by treatment with GIcNAc. Upon treatment with O‐glycanase the MSP‐2 glycoprotein released lablled amino sugar, and derived oligosaccharides on treatment with exoglycosidases released labelled components corresponding to the metabolically incorporated sugars. Labelled Gal was incorporated into the MSP‐2 glycoprotein using [3H]UDP‐Gal and galactosyltransferase. The galactosylated glycoprotein released labelled Gal upon treatment with β‐galactosidase. The results of the present study suggest that the carbohydrate chains of the MSP‐2 glycoprotein are attached to the protein backbone via GlcNAc‐ and GalNAc‐sedne/threonine in O‐glycosyl linkage and the glycoprotein has terminal GlcNAc and Gal residues. The carbohydrate moieties of MSP‐2, glycoprotein consist mainly of short chains linked to the protein core.
Identification of an “alcohol dehydrogenase‐activating” protease in grass carp hepatopancreas as A chymotrypsin
Authors: Lau King‐kwan , Chan Elaine Yee‐man , Fong Wing‐ping 
Published: July 2007

AbstractPrevious investigation [Tsui et al. (1996) Biochim. Biophys. Acta 1269: 41‐46] showed that two active forms of alcohol dehydrogenase can be purified from grass carp. The use of a protease inhibitor and the results of SDS‐PAGE analysis of the enzymes suggest that one form (ADH‐C) is a proteolytic product of the other (ADH‐I). In this study, the protease responsible for the cleavage was purified. The cleavage enzyme had a subunit molecular weight of 28 kDa. An inhibitor study identified it as a serine protease. It exhibited a strong chymotrypsin activity in both esterase and amidase assays with a pH optimum in the range 7.5‐8.5. The purified chymotrypsin also cleaved the intact grass carp ADH‐I into the two‐fragment ADH‐C, with an accompanying increase in enzyme activity. A similar effect was not found using horse liver alcohol dehydrogenase.
Modulation of macrophage heat shock proteins (HSPs) expression in response to intracellular infection by virulent and avirulent strains of Leishmania donovani
Authors: Adhuna Poonam Salotra , Mukhopadhyay Bani , Bhatnagar Rakesh 
Published: July 2007

AbstractWe have examined the differential expression of heat shock proteins of murine macrophage‐like cell line J774.G8 following infection with Leishmania donovani. In response to infection with virulent promastigotes, the up‐regulation of HSP70 and 90 and a selective down‐regulation of HSP60 was observed using monoclonal antibodies specific for host HSPs. However, infection with avirulent strain failed to alter the expression of host HSPs. The maximum alterations in HSPs expression were noted at 18h post infection, a time period which coincided with the transformation of parasite from promastigote to the amastigote form. Data indicates that host HSPs may play a role in parasite differentiation/survival during infection with L. donovani.
Brain glutamate dehydrogenase changes in streptozotocin diabetic rats as a function of age
Authors: Biju M. P. , Paulose C. S. 
Published: July 2007

AbstractKinetic parameters of brain glutamate dehydrogenase (GDH) were compared in the brain stem, cerebellum and cerebral cortex of three weeks and one year old streptozotocin (STZ) induced four day diabetic rats with respective controls. A single intrafemoral dose of STZ (60mg/Kg body weight) was administered to induce diabetes in both age groups. After four days the blood glucose levels showed a significant increase in the diabetic animals of both age groups compared with the respective controls. The increase in blood glucose was significant in one year old compared to the three weeks old diabetic rats. The Vmax of the enzyme was decreased in all the brain regions studied, of the three weeks old diabetic rats without any significant change in the Km. In the adult the Vmax of GDH was increased in cerebellum and brain stem but was unchanged in the cerebral cortex. The Km was unchanged in cerebellum and cerebral cortex but was increased in the brain stem. These results suggest there may be an important regulatory role of the glutamate pathway in brain neural network disturbances and neuronal degeneration in diabetes as a function of age.
Additive effects of bovine serum albumin, dithiothreitol and glycerolon PCR
Authors: Nagai Masazumi , Yoshida Akihide , Sato Nobuko 
Published: July 2007

AbstractThe effects of bovine serum albumin, dithiothreitol, and glycerol on PCR were studied. PCR under standard conditions failed the amplification of an enterohemorrhagic E. coli DNA fragment when the boiled bacterial cell lysate was used as the template. The addition of either one of bovine serum albumin, dithiothreitol, or glycerol in the reaction mixture allowed the specific fragment amplification; and the optimum concentrations were as follows: bovine serum albumin, 1 mg/ml; dithiothreitol, 10 mM; and glycerol, 5%. In addition, when all of the three agents were included at the above concentrations, the PCR yeild was further increased. The effect of the three‐agent mixture was not the template specific. Furthermore, the mixture enabled long PCR over 20 kb when Taq DNA polymerase with 3′‐5′ exnuclease activity was used for the amplification. Our simple PCR method allows robust PCR independent of template purity or amplification length.
Esr studies of vitamin c regeneration, order of reactivity of natural source phytochemical preparations
Authors: Cossins Elaine , Lee Reaching , Packer Lester 
Published: July 2007

AbstractThe effect of various flavonoids upon the ascorbate radical lifetime was investigated by ESR spectroscopy. The radical was generated via the reaction between ascorbic acid and ascorbate oxidase, the ascorbate radical being detected. The inclusion of the flavonoids in the ascorbic acid‐ascorbate oxidase reaction mixture affected both the initial intensity of the ascorbate radical and its lifetime. Of the natural sources tested, Pycnogenol® prolonged the ascorbate radical lifetime to the greatest extent, from a control value of 20 rain to a maximum of 80 min with 200 μg/ml Pycnogenol®. The flavonoids could either be regenerating ascorbic acid from ascorbate, or interacting with ascorbate oxidase, thus preventing ascorbic acid binding. When p‐cresol, a known ascorbate oxidase inhibitor was added to the ascorbic acid‐ascorbate oxidase reaction mixture, the ascorbate radical signal intensity was dramatically reduced and did not display the time‐dependent decay observed with the flavonoids. This indicates that a direct interaction between the flavonoids and ascorbate radical occurs. Some of the flavonoids tested; myricetin, polyphenon and theaflavin appeared to compete with ascorbic acid for ascorbate oxidase, as they displayed saturation behaviour. By modifying the experimental conditions the myricetin radical was detected, thus confirming the direct interaction between myricetin and ascorbate oxidase
Analysis of glycosphingolipids of human head and neck carcinomas with comparison to normal tissue
Authors: Bolot G. , David M. J. , Taki T. , Handa S. , Kasama T. , Richard M. , Pignat J. C. , Thomas L. , Portoukalian J. 
Published: July 2007

AbstractGlycosphingolipids of head and neck carcinomas from six tumor‐bearing patients were analyzed and compared to those of normal tissue from similar areas. The total glycosphingolipid content and the lipid‐bound sialic acid were much higher in carcinomas than in normal tissue. Major neutral glycolipids were glucosylceramide, lactosylceramide, trihexosylceramide and paragloboside. Sulfatides were seen only in extracts from normal tissue which also showed a rather simple ganglioside pattern with #GM3 and GD3 as major species, whereas tumors showed additional species such as GM2 and GD2, along with a strong increase in LM1, GM1, GDla and GT1b.