bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic fate and effects of saturated and unsaturated fatty acids in Hep2 human larynx tumor cells
Authors: Colquhoun Alison , Curi Rui 
Published: July 2007

AbstractPrevious studies have reported the presence of carnitine palmitoyltransferase I and II in tumor cells and the inhibitory effects of fatty acids on cell proliferation. The present work considered the metabolic fate of [14C] or [3HI‐labeled fatty acids and their effects on cellular metabolism in Hep2 human larynx tumor cells.The rate of uptake of acetate was 45% of that of myristate, palmitate, oleate, linoleate and arachidonate. However, acetate was rapidly metabolized within the cell as seen by its low rate of accumulation as non‐esterified fatty acid, <5% of that of the other fatty acids. The incorporation of fatty acids into neutral lipid fractions showed palmitate and oleate primarily entered the phospholipid fraction, while linoleate and arachidonate entered equally the phospholipid and triacylglycerol fractions. Palmitate and oleate were oxidized to 14CO2 at higher rates than linoleate and arachidonate, with arachidonate being the least oxidized of the unsaturated fatty acids. Acetate was oxidized at 10‐30 fold higher rates than the other fatty acids. Palmitate, oleate, linoleate and arachidonate all had significant inhibitory effects on the rate of glucose utilization by Hep2 cells, ranging from 25‐38% inhibition and were found to inhibit cell proliferation by 17‐73%. These findings suggest that certain fatty acids not only play a structural role in cellular metabolism, but may also have a potential regulatory role in the glycolytic pathway of Hep2 cells.
Enhanced production of LTB4 and free radicals in rat lung by exhaustive physical exercise
Authors: Kumar T. Charles , Reddy K. Veera , Anuradha D. , Reddanna P. 
Published: July 2007

AbstractLeukotrienes formed by the action of 5‐lipoxygenase on arachidonic acid are a group of endogenous compounds active in hypersensitivity reactions and inflammation. In this report the formation of LTB4 from LTA4 was measured by incubating lung microsomes from normal and exercised rats to determine whether LTB4 may have a role in the mediation of exercise‐induced oxidant stress. Exhaustive exercise in the form of swimming results in the enhanced production of LTB4 in lung microsomes. Further, free radicals measured by ESR spectroscopy were also significantly increased in lung tissue from exercised rats. These results suggest a role for LTB4 in the mediation of lung tissue damage during exercise‐induced oxidative stress.
The protective effects of dihydrolipoamide and glutathione against photodynamic damage by Al‐phtalocyanine tetrasulfonate
Authors: Kliukiené Regina , Maroziene Audroné , Nivinskas Henrikas , Čénas Narimantas , Kirveliené Vida , Juodka Benediktas 
Published: July 2007

AbstractIn spite of well‐known ability of lipoamide/dihydrolipoamide (LipS2NH2/Lip(SH)2 NH2) and oxidized/reduced glutathione (GSSg/GSH) couples to scavenge singlet oxygen (1O2), the possible protective effects of these compounds against photodynamical damage by Al‐phtalocyanine tetrasulfonate (Al‐PcS4) were examined. Using erythrocyte glutathione reductase, pig heart lipoamide dehydrogenase and hamster kidney fibroblast culture as model systems, we have found that protective effects of Lip(SH)2NH2 and LipS2NH2 were close to that of azide, far exceeding the effects of GSH and GSSG, and paralleling the rates of Al‐PcS4‐sensitized photooxidation of these compounds. We have failed to observe a previously described (Devasagayam, T.P.A., et al. (1991) Biochim. Biophys. Acta 1088, 409‐412) enhancement of damaging action of 1O2 by GSH. These findings point out to the possibility of LipS2NH2/Lip(SH)2NH2 to neutralize the side‐effects of photodynamic therapy, and to a minor but definitely protective role of GSH.
Renaturation and purification of recombinant tissue‐type plasminogen activator expressed in E. coli
Authors: Hua Zi‐Chun 
Published: July 2007

AbstractUnder the control of trp promoter, human tissue‐type plasminogen activator was expressed in E. coil in the form of inclusion body. The recombinant t‐PA was recovered for renaturation from preparative native PAGE gel by zinc acetate staining and electroelution. After renaturation in vitro, the recombinant t‐PA was purified by benzamidine affinity chromatography and lysine affinity chromatography. The purified t‐PA showed homogeneous on silver‐stained SDS‐PAGE gel, with a specific activity of 240,000I.U./mg protein.
An essential tryptophan residue of green crab (Syclla Serrata) alkaline phosphatase
Authors: Zheng Wen‐Zhu , Chen Qing‐Xi , Zhao Hong , Zhang Zhe , Zhang Wei , Zhou Hai‐Meng 
Published: July 2007

AbstractThe tryptothan residues in green crab (scylla serrata) alkaline phosphatase (EC 3.1.3.1) have been modified by N‐bromosuccinimide (NBS). The modification of five tryptophan residues leads to complete loss of enzymatic activity. With the increase of NBS concentration, both the absorption at 278 nm and the fluorescence emission intensity at 335 nm of the modified enzyme decreased markedly indicating the modification of tryptophan residues. Quantitative treatment of the data (Tsou, Sci. Sinica 1962, 11, 1535‐1558) shows that among the tryptophan residues modified, one is essential for its catalytic activity. The presence of the substrate markedly protects the modification of tryptophan residues as well as the inactivation, suggesting that the essential tryptophan residue is situated at the active site of this enzyme.
The large ribosomal protein gene cluster of a cryptomonad plastid: Gene organization, sequence and evolutionary implications
Authors: Wang Sheng‐Long , Liu Xiang‐Qin , Douglas Susan E. 
Published: July 2007

AbstractThe complete sequence of the major ribosomal protein gene cluster of the plastid genome of the cryptomonad alga Guillardia theta (formerly Cryptomonas Φ) is presented. The ribosomal protein genes (corresponding to the SIO, spc, alpha and L13/S9 operons of E. coli are found upstream of the previously reported plastid str operon, and transcribed in the same orientation. The genes are very tightly packed with as little as two nucleotides between the rpll4 and rpl24 genes. The gene arrangement is very similar to that reported for the rhodophyte alga, Porphyra purpurea, and the chromophyte diatom, Odontella sinensis, indicating a close evolutionary relationship between these groups of algae. Northern analysis indicates that the 29 genes1 are arranged as one operon and are transcribed as a single mRNA that is subsequently processed into smaller transcripts.
High‐level expression of cecropin CMIV in E. coli from a fusion construct containing the human tumor necrosis factor
Authors: Wang Liang , Wu Haihong , Dou Fei , Xie Wei , Xu Xianxiu 
Published: July 2007

AbstractCecropin CMIV gene was fused to the 3′‐terminus of the mutated tumor necrosis factor (TNFb) gene and the fusion gene was directly under the control of an inducible T7 promoter in pET‐11d. This fusion gene was overexpressed in Escherichia coli with an expression level of approximate 40%‐50% of total cellular proteins, and was produced mainly in the form of inclusion body. Peptide with antibacterial activity was obtained by cleaving the fusion protein with CNBr.
Evidence for antiradical and antioxidant properties of four biologically active N,N‐Diethylaminoethyl ethers of flavaone oximes: A comparison with natural polyphenolic flavonoid rutin action
Authors: Metodiewa Diana , Kochman Agata , Karolczak Stefan 
Published: July 2007

AbstractThe antiradical and antioxidant activities of four biologically active N,N‐diethyloaminoethyl ethers of flavanone oximes (N,N‐DEAEFo) were investigated in vitro and compared with these of polyphenolic flavonoid (rutin). Four experimental models were used: iron‐ and ascorbate driven Fenton systems, γ‐radiolysis, xanthine/xanthine oxidase system and diphenylpicrylhydrazyl (DPPH) radical scavenging. The results clearly indicate that N,N‐DEAEFo are acting as promising antioxidants and radioprotectors comparable to rutin activities: they should prove to be useful under acute oxidative stress conditions for which both properties were required.
Substances in the aqueous fraction of cigarette smoke inhibit lipid peroxidation in synaptosomes of rat cerebral cortex
Authors: Kamisaki Yoshinori , Wada Kouichirou , Nakamoto Kentaro , Kishimoto Yosuke , Ashida Kumiyo , Itoh Tadao 
Published: July 2007

AbstractThe effects of water‐soluble substances in cigarette smoke on lipid peroxidation were investigated using nerve terminals prepared from the rat cerebral cortex. The prepared smoke‐substances significantly reduced the spontaneous increase in thiobarbituric acid‐reactive substances in synaptosomes in a dilution factor‐dependent manner. Furthermore, the aqueous extract also inhibited the elevation of lipid peroxidation induced by 2,2′‐azobis (2‐amidinopropane) dihydrochloride, a peroxyl radical generator. Smoke‐substances scavenged superoxide radicals generated from stimulated human leukocytes and from the xanthine/xanthine oxidase system. These effects were not mimicked by nicotine. The antioxidant effects of smoke‐substances were preserved for several days at 5 ° or ‐80 °C. The results suggest that the smoke‐substances may possess long half‐lives and scavenge the radicals which cause lipid‐peroxidation in synaptosome membranes.
Ontogeny of neurotransmitter amino acids in human fetal brains
Authors: Das Shyamal K. , Ray Pradip K. 
Published: July 2007

AbstractA wide spectrum of developmental profiles is presented for a few important neurotransmitter amino acids, namely γ‐aminobutyric acid, glycine, glutamic acid, aspartic acid and taurine as well as the key enzymes involved in their metabolism in human fetal brains of different gestational ages. Besides taurine almost all these amino acids and their key metabolic enzymes were found to be progressively enhanced upto the mid period of third trimester of pregnancy indicating a rapid growth of nerve processes, myelination and maturation of fetal brains particularly during this period. Interestingly taurine showed an inverse relationship of ontogenic pattern with respect to its biosynthesizing enzyme in fetal brains.
Glucose transport in a murine mammary epithelial cell line
Authors: Bennett Brydon L. , Grigor Murray R. , Prosser Colin G. 
Published: July 2007

AbstractThe glucose transport systems of the COMMA‐D cell line (a murine mammary epithelial cell line) were examined using 2‐deoxyglucose as substrate. The kinetics and inhibition studies with other sugars including xylose suggested that the transport system had properties of both GLUT‐1 and Gtut‐3. Subsequent analysis of mRNA transcripts using cDNAs for GLUT‐1 to 4 showed that only GLUT‐1 was expressed in the COMMA‐D cells. The results highlight the fact that kinetic and substrate specificity are not sufficient, by themselves, for the identification and characterisation of GLUT isoforms in cultured cells.
Partial restoration of inactivated ribosomes: role of the aldehyde group generated by RNA N‐glycosidase in the sarcin/ricin domain of 28S rRNA in ribosome
Authors: Cheng Le‐Ping , Liu Wang‐Yi 
Published: July 2007

AbstractIn this paper, we report more information on the important role of the aldehyde group in the sarcin/ricin domain of 28S rRNA in rat liver ribosome. We find D‐amino acids, amino acid derivatives having free amino group and two polyamines can also partially restore the activity of cinnamomin‐inactivated ribosomes. However, amino acid derivatives and a tripeptide with blocked amino group cannot. Neither sodium borohydride nor the L‐amino acids can restore the activity of ribosomes inactivated by α‐sarcin. These data demonstrate that partial restoration of the activity of the inactivated ribosome is indeed the result of the blockage of the aldehyde group. It reaches the conclusion that emergence of the active aldehyde group in the sarcin/ricin domain of 28S rRNA is one of factors that inactivate the ribosome for protein synthesis.
Production and characterisation of monoclonal and polyclonal amtobpdoes agaomst bovine osteocalcin
Authors: Nielsen Peter Kresten , Hønberg Lisbeth Skou , Larsen Torben , Sperling‐Petersena Hans Uffe , Sottrup‐Jensen Lars 
Published: July 2007

AbstractMonoclonal and polyclonal antibodies were produced against osteocalcin purified from bovine bone. The antibodies were used for the development of a two‐site ELISA. A monoclonal antibody recognising residues 15‐49 of bovine osteocatcin generated by cleavage with 70% formic acid was used as capture antibody and a biotinylated polyclonal antibody recognising the same peptide was used for detection. The two‐site assay did not detect any tryptic peptides of bovine osteocalcin (residues 1‐19, 20‐43, and 45‐49) nor did it detect the peptide 1‐14 or the synthetic peptide 37‐49. Cross‐reaction was observed for osteocalcin in plasma from sheep, goat, chicken and human but not for osteocalcin from rat and pig.
Synergistic effect of glycolic acid on the antioxidant activity of α‐tocopherol and melatonin in lipid bilayers and in human skin homogenates
Authors: Morreale Massimiliano , Livrea Maria A. 
Published: July 2007

AbstractConsiderable interest has been raised concerning the use of natural compounds in preventing skin aging and photoaging. In the idea that the combined action of agents increasing epidermal turnover with antioxidants could be advantageous in cosmetic and therapeuthic treatments, we first investigated if α‐glycolic acid affected or prevented the antioxidant activity of vitamin E and of melatonin, two compounds found beneficial as topical photoprotectant. Assays were carried out in vitro either in a biomimetic liposomal system, or in human skin homogenates. Lipid peroxidation was monitored spectrophotometrically by the time course of lipid hydroperoxide production in liposomes and by formation of TBA reactive substances (TBARS) in skin homogenates. Glycolic acid. at 25 μM to 1 mM, showed a mild, concentration‐dependent antioxidant effect in liposomes, as evaluated by a slight decrease of the peroxidation rate, while, at 1 mM, reduced TBARS production in skin homogenates by 14 %. Combinations of either vitamin E or melatonin with glycolic acid, in a 1:5 to 1:200 molar ratio, resulted in a clear synergistic protection of liposomes, more evident for the combination of glycolic acid with vitamin E. An amount of synergism up to 250% and up to 80% was evahmted with vitamin E and melatonin, respectively. Consumption rate of vitamin E during peroxidation of liposomes, in the absence or in the presence of glycolic acid, suggests that regeneration of vitamin E may in part explain the observed synergism. Synergistic antioxidant activity between vitamin E and glycolic acid was also observed in skin homogenates, whereas the effect of glycolic acid on the antioxidant activity of melatonin appeared additive. However, the combination of these three compounds inhibited TBARS production almost completely.Our data provide evidence that glycolic acid can strongly potentiate the antioxidant action of melatonin and vitamin E. This may suggest the advantage of combining α‐glycolic acid with these antioxidants in skin designed preparations, both to improve penetration and availability of antioxidants to epidermal layers and to enhance their protective potential.
Evidence that Fe‐NTA‐induced renal prostaglandin F2α is responsible for hyperplastic response in kidney: Implications for the role of cyclooxygenase‐dependent arachidonic acid metabolism in renal tumor promotion
Authors: Iqbal Mohammad , Giri Uma , Giri Dipak K. , Athar Mohammad 
Published: July 2007

AbstractOxidative stress in a tissue activates phospholipase A2 which releases free arachidonic acid. In addition, a low grade oxidative tone also stimulates the tissue cyclooxygenase activity. Cyclooxygenase‐dependent arachidonic acid metabolites such as PGF2α are known to play an important role in the development and maintenance of hyperplasia in skin in response to the application of tumor promoters. In this study we show that Fe‐NTA, an oxidant renal tumor promoter induces PGF2α which was maximum at 12 hours after Fe‐NTA treatment. However, at all time points studied, the elevated levels of PGF2α have been observed. As a result of the induction of PGF2α, the hyperplastic response can also be observed in the histopathology of the tissue. Additionally, an increased incorporation of [3H]thymidine in renal DNA has also been observed. Pretreatment of animals with indomethacin suppresses Fe‐NTA‐mediated hyperproliferation suggesting a role of cyclooxygenase in Fe‐NTA‐mediated stimulation of hyperplastic activity. The pretreatment of animals with the chain breaking antioxidants, Vit. E, BHA and BHT were only partially effective in inhibiting Fe‐NTA‐mediated PGF2α production, further suggesting a role of non‐free radical‐dependent mechanism in its production. Our data suggest that Fe‐NTA‐induced PGF2α through the activation of cyclooxygenase is responsible for the development and maintenance of hyperplasia in kidney.
The increased level of PDGF‐A contributes to the increased proliferation induced by mechanical stimulation in osteoblastic cells
Authors: Wang Wei , Zhuang Hongming , Levitz Craig L. , Fan Huijun , Seldes Richard M. , Tahernia A. David , Brighton Carl T. 
Published: July 2007

AbstractMechanical stimulation can prompt healing of bone fractures. However, it is largely unknown how osteogenesis is promoted by mechanical stimulation. In this study, we found that mechanical strain‐induced proliferation of osteoblastic cells (MC3T3‐E1) accompanied increased levels of platelet‐derived growth factor‐A (PDGF‐A) mRNA, determined by quantitative reverse transcription/polymerase chain reaction. In addition, neomycin and W‐7, which blocked mechanical strain‐induced proliferation of the osteoblast cells, also blocked mechanical stimulation‐induced elevation of PDGF‐A mRNA. Finally, an antibody against PDGF can inhibit physical stimulation‐induced proliferation of MC3T3‐E1 ceils, suggesting that the increased MC3T3‐E1 cells produced by mechanical stimulation at least partially depends on the increased activity of PDGF.
Studies on growth‐promoting action of insulin: mitogenic activity of insulin and its analogues in mouse mammary tumor cells
Authors: Shi Min , Feng You‐Min 
Published: July 2007

AbstractGrowth‐promoting action of insulin and its analogues was studied in the mouse mammary tumor cell line GR2H6 by measuring 3H‐thymidine incorporation. The mitogenic activity of the analogues obtained by shortening of C‐terminus of insulin B chain decreased with stepwise removal of terminal residues, and [A3Leu]insulin was approximately 1000 times less potent than insulin. However, the despentapeptide(B26‐B30) insulin(DPI) showed a strikingly higher mitogenic activity at high concentrations; the detected maximal effect of DPI was 136% more than that of insulin. These results demonstrate that the C‐terminal area of the B chain and the N‐terminal α‐helix of the A chain are important for the mitogenic activity of insulin. A region corresponding to the growth‐promoting function of insulin and a model of DPI action are proposed and discussed.
Inhibition of interleukin‐6‐induced human immunodeficiency virus type 1 expression by anti‐GP130 monoclonal antibody
Authors: Okamoto Mika , Yasukawa Kiyoshi , Katsuura Kimio , Baba Masanori 
Published: July 2007

AbstractInterleukin 6 (IL‐6) has been reported to upregulate the expression of human immuno‐deficiency virus type 1 (HIV‐1) in infected monocyte/macrophages. Since IL‐6 signal is transduced through the membrane glycoprotein gp130, we investigated the inhibitory effect of anti‐gp130 monoclonal antibody (mAb) on IL‐6‐induced viral expression in monocytic cell lines latently infected with HIV‐I. IL‐6 significantly induced the expression of HIV‐1 in U1 cells, whereas it had no effect in OM‐10.1 cells. Flow cytometric analysis revealed that U1 but not OM‐10.1 cells expressed gp130 on their surface. The anti‐gp130 mAb could inhibit IL‐6‐induced HIV‐1 expression in U1 cells in a dose dependent fashion. These results suggest that blocking the gp130 signal transduction may have therapeutic potential for the treatment of HIV‐1 infection.
Insulin rapidly stimulates ERK2 in the membrane of osteoblast‐like UMR‐106 cell
Authors: Kim Sung‐Jin , Kim Kyung‐Ha 
Published: July 2007

AbstractWe investigated subcellular distribution of ERK2 in osteoblast‐like UMR‐106 cell and explored to determine if its activities are regulated by insulin. 23%, 34% and 43% of total ERK2 were distributed in membrane, cytosol and nucleus, respectively. Insulin caused 40% increase of ERK2 content in membrane in 10 min whereas it induced approximately 50% decrease of ERK2 in cytosol in 10 min. In terms ofkinase activity, insulin stimulated phosphorylation of the membrane‐associated ERK2 by 2‐fold and 1.8‐fold in 1 min and 10 min and cytosolic ERK2 by 2.7‐fold and 2.3‐fold in 1 min and 10 min, respectively. In contrast, the phosphorylation of nuclear ERK2 was stimulated by insulin in time‐dependent manner with maximal (3‐fold) activity observed at 30 min. Insulin also increased the content of MEK2 in membrane by 2.2‐ to 2.6‐fold in 10 min. MEK2 translocated into mambrane in response to insulin may play a role in the activation of the membrane‐associated ERK2 via phosphorylation.
Protein degradation in red cells exposed to 2,2′‐azo‐bis(2‐amidinopropane) derived radicals
Authors: Celedón G. , Lips V. , Alvarado C. , Cortés M. , Lissi E. A. , González G. 
Published: July 2007

AbstractExtensive proteolysis is observed when red blood cells are exposed to free radicals produced in the thermolysis of 2,2′‐azo‐bis(2‐amidinopropane). It is evaluated that nearly one amino terminal group is produced by each free radical introduced into the system. These groups are considered to arise mainly from band 3 fragmentation due to the action of red cell proteinases. Protein fragmentation takes place prior to significant hemolysis or lipid peroxidation, as evaluated by thiobarbituric acid‐reactive substances measurements.
Prolactin‐induced expression of TATA‐less cyclin D3 gene is mediated by Sp1 and AP2
Authors: Yang Miao , Nomura Hideki , Hu Ying , Kaneko Satoshi , Kaneko Hiroshi , Tanaka Minoru , Nakashima Kunio 
Published: July 2007

AbstractThe TATA‐less cyclin D3 gene is stimulated by prolactin (PRL) in rat Nb2 T‐lymphocytes. DNA mobility shift assay and luciferase transfection analysis revealed that the gene has a potential promoter region, two enhancer domanins and a silencer region. The promoter region possessed three Sp1 sites and two AP2 sites, and both enhancer regions bad one AP2 binding site each. Analysis using oligonucleotide probes and purified AP2 protein has suggested that the expression of rat cyclin D3 gene is promoted by Sp1 and AP2 factors.
Comparison of bilirubin binding and other molecular properties of tile serum albumin of several mammalian species
Authors: Rashid Huma , Muzammil Salman , Tayyab Saad 
Published: July 2007

AbstractIn order to develop an animal model for in vivo testing of the displacing action of various drugs and for study of the bilirubin deposition in the brain, some molecular properties of the serum albumin from different species i.e. pig, cat, human, dog, sheep, guinea pig and rat were investigated. These albumins were found to have differences in molecular weight, Stokes radius and electrophoretic mobility. They also showed different bilirubin binding characteristics when studied by spectroscopy and fluorescence quenching. It is therefore, necessary to consider the species differences when results of animal experimentation are used as a basis for the investigation of human kernicterus.