bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro transcription of c‐jun gene using fractionated nuclear extract from regenerating rat liver
Authors: Sharma Dipali , Choudhary Shailesh Kumar , Dixit Aparna 
Published: July 2007

AbstractRegenerating rat liver serves as a source of proliferating cells, such a system can be used to study the regulation of genes involved in proliferation. We have established an in vitro transcription capable of supporting accurate transcription of cloned c‐jun gene using fractionated nuclear extract prepared from partially hepatectomized rat liver. EcoR I linearized plasmid ‐132/+170 jun‐CAT containing c‐jun gene promoter region (‐132 to +170 nucleotides) was transcribed in an in vitro run‐off transcription assay and a transcript of expected size i.e. 370 nucleotides was obtained. The intensity of the transcript was dependent on the concentration of fractionated nuclear extract as well as template. The transcription was α‐amanitin sensitive indicating that it is directed by RNA polymerase II.
Differential oligomerization of membrane‐bound CD38/ADP‐ribosyl cyclase in porcine heart microsomes
Authors: Chidambaram Natesavelalar , Wong Ee Tsin , Chang Chan Fong 
Published: July 2007

AbstractA protein fraction displaying ADP‐ribosyl cyclase activity was purified from porcine heart microsomes which appeared as a major band of 45 kDa on Coomassie blue stained SDS‐PAGE gel under reducing condition. Protein immunoblot analysis with antiserum to recombinant rat CD38 showed a series of bands (45‐285 kDa) under non‐reducing condition, while only the 45 kDa monomer under reducing condition. The high molecular weight oligomers of CD38 were found to be stable even upon treatment with various concentrations of SDS in the sample buffer and also upon incubation at lower temperature. These oligomers of CD38 also displayed higher ADP‐ribosyl cyclase activity than that of the monomer.
Effect on colon cancer cells of human interferon‐β gene entrapped in cationic multilamellar liposomes
Authors: Shimizu Minoru , Akiyama Seiji , Ito Katsuki , Kasai Yasushi , Takagi Hiroshi , Kito Mariko , Ohishi Nobuko , Yagi Kunio 
Published: July 2007

AbstractWhen cultured cells of human colon cancer cell line SW480 were transfected with human interferon‐β (hIFN‐β) gene by means of cationic multilamellar liposomes, the endogenously produced hIFN‐β exhibited a remarkable anti‐proliferative effect on the cells, which was more effective than that of exogenously added hIFN‐β. This effect lasted for several days, and was blocked completely by the addition of sufficient amounts of anti‐hIFN‐β antibody. From experiments using a transwell plate and an infusion pump, we found that endogenously produced hIFN‐β acted effectively on the cells around the transfectants and that the growth‐inhibitory effect was totally retained upon continuous dilution of the medium. These data indicate that hIFN‐β expressed endogenously by transfer of its gene acted on these cancer cells mainly in a paracrine manner. Although the transfection with hIFN‐γ gene also revealed a definite growth‐inhibitory effect on the same tumor cells, the extent was less than that of hIFN‐β gene.
Reductive dechlorination of DDT to DDD by rat blood
Authors: Sugihara Kazumi , Kitamura Shigeyuki , Ohta Shigeru 
Published: July 2007

AbstractThe present study provides evidence that the reductive dechlorination of DDT (p, p'‐dichlorodiphenyltrichloroethane) to DDD (p, p'‐dichlorodiphenyldichloroethane) mediated by rat blood proceeds in the presence of both a reduced pyridine nucleotide and aflavin. The reduction appears to proceed in two steps. The first step is reduction of a flavin such as FAD, FMN or riboflavin by NADPH or NADH, either enzymatically or nonenzymatically. The second step is nonenzymatic reductive dechlorination of DDT by the reduced flavin, catalyzed by the heme group of hemoglobin.
Hydrogen peroxide‐supported activities of semisynthetic flavocytochrome 2B4
Authors: Shumyantseva Victoria V. , Avdeenko Yuliya L. , Moskvitina Tatyana L. , Bulko Tatyana V. , Archakov Alexander I. 
Published: July 2007

AbstractSemisynthetic flavocytochromes, obtained by covalent binding of riboflavin with cytochromes P450 2B4, were able to catalyze the H202‐mediated reactions of aniline p‐hydroxylation, aminopyrine N‐demethylation and p‐nitroanizole O‐dealkylation. The rates of the flavocytochrome‐catalyzed, H202‐supported reactions far exceeded those of the appropriate NADH‐dependent reactions and were comparable with the cytochrome P450 2B4‐catalyzed, peroxide‐mediated reaction rates. The kinetic parameters (kcat, Km) for the peroxide‐dependent flavocytochrome P450 2B4 reactions were obtained. Sodium cyanide and SKF‐525A, a specific P450 inhibitor, were both shown to inhibit these reactions. The generation of active oxygen species by flavocytochrome 2B4 was registered by chemiluminescence intensity.
A novel rapid‐reaction spectrophotometric method for monitoring monovalent anion exchange by human erythrocyte band 3
Authors: Salhany James M. 
Published: July 2007

AbstractThiocyanate (SCN‐) uptake into human erythrocytes and resealed ghosts was measured by monitoring the intracellular reaction of SCN‐ with methemoglobin using a dual wavelength stopped‐flow apparatus. The cellular reaction was considerably slower than the reaction of SCN with methemoglobin in solution, indicating that SCN‐ diffusion and not chemical reaction was rate limiting. This view was confirmed by showing that the uptake rate followed saturation kinetics ( Km〈9 mM), thus indicating that SCN‐ transport involves a facilitated diffusion process. Addition of DIDS ( 4,4′‐diisothiocyanatostilbene‐2,2′‐disulfonate) totally inhibited SCN‐ uptake, thus identifying band 3 as the sole facilitator. Substitution of iodide or sulfate for trans chloride, slowed SCN‐ uptake by 4‐fold and 35‐fold respectively. Reducing the trans chloride concentration from 150 to 2 mM decreased the extent of the reaction, and slowed the observed rate by about 2‐fold. These results define a new approach for the continuous monitoring of monovalent anion exchange by human erythrocyte band 3.
Subcellular distribution of the R‐subunits of cAMP‐dependent protein kinase in LS‐174T human colon carcinoma cells
Authors: Kondrashin A. A. , Nesterova M. V. , Cho‐Chung Y. S. 
Published: July 2007

AbstractThe analysis of the particulate preparations of LS‐174T human colon carcinoma cells in confluent stage of growth revealed different distribution for regulatory subunits (R) of cAMP‐dependent protein kinase (PKA) in the subcellular compartments. The LS‐174T cell lysates were subjected to differential and discontinuous sucrose density gradient centrifugation. The obtained fractions were assayed for marker enzymes and photoaffinity labeled with 8‐N3[32P]cAMP. The whole lysates and cytoplasmic fraction exhibited the presence of both RIα and RIIα ‐ subunits of PKA. The fractions exhibiting high activity of the marker enzymes for plasma membranes, Golgi apparatus and mitochondria contained mainly RIIα. In the fractions of lysosomes and microsomes RIα and RIIα were found in nearly equal amounts.
Effects of La3 on lipid fluidity and structural transitions in human erythrocyte membranes
Authors: Li Xin‐Min , Ni Jia‐Zuan , Chen Jian‐Wen , Hwang Fen 
Published: July 2007

AbstractThe effects of La3+ on the structure and function of human erythrocyte membranes were investigated by fluorescence polarization, spin‐labeled electron spin resonance (ESR) and differential scanning calorimetry (DSC). The results showed that increasing concentrations of La3+ inhibited (Na++K+)‐ATPase and Mg2+‐ATPase activities. La3+ lowered the lipid fluidity of erythrocyte membranes and induced structural transitions in erythrocyte membranes.
Induction of apoptosis by polyunsaturated fatty acids and its relationship to fatty acid inhibition of carnitine palmitoyltransferase I activity in Hep2 cells
Authors: Colquhoun Alison 
Published: July 2007

AbstractThe effects of fatty acids on the induction of apoptosis were studied over a 24 hour period in Hep2 human larynx tumour cells. While oleic and linoleic acids had little effect on the apoptotic index, the polyunsaturated fatty acids α‐linolenie, γ‐linolenic, arachidonic, eicosapentaenoic and docosahexaenoic acids all induced apoptosis, beginning at ∼6 hours after fatty acid exposure. By 24 hours after exposure, the apoptotic index had reached as much as 19% in the presence of docosahexaenoic or α‐iinolenic acid. The correlation between degree of unsaturation of the 18‐carbon fatty acids and the apoptotic index was r2=0.45, 0.89, 0.84 and 0.98 at 6, 8, 12 and 24 hours, respectively. The correlation between mitochondrial carnitine palmitoyltransferase I (CPT I) activity, 6 hours after exposure, and the apoptotic index was r2=0.842 and 0.798 at 12 and 24 hours, respectively. The inhibition of CPT I and subsequent fatty acid oxidation by polyunsaturated fatty acids leads to a significant increase in apoptosis, suggesting that CPT I may be involved in the processes of programmed cell death in Hep2 human turnout cells.
Captopril ameliorates myocardial and hematological toxicities induced by adriamycin
Authors: Al‐Shabanah Othman , Mansour Mahmoud , El‐Kashef Hassan , Al‐Bekairi Abdullah 
Published: July 2007

AbstractAdriamycin has a wide spectrum of antitumor activity with dose related cardiotoxicity as a major side effect. The objective of this study was to investigate the influence of captopril, a sulphydryl containing angiotensin converting enzyme inhibitor, on the cardio‐and hematotoxicity of adriamycin in normal rats. A single dose of adriamycin (15 mg/kg) caused myocardial toxicity after 24 h manifested biochemically by elevation of serum enzymes:‐ Aspartate transaminase (AST, EC: 2.6.1.1), lactate dehydrogenase (LDH, EC: 1.1.1.27), creatine phosphokinase (CPK, EC:2.7.3.2) and the cardiac iso‐enzymes of LDH and CPK. The hematotoxicity was characterized by severe leukopenia and anemia that appeared after 72 h of adriamycin adminstration. Captopril (60 mg/kg i.p) 1 h before adriamycin injection ameliorated the biochemical toxicity induced by adriamycin. This was evidenced by a significant reduction in serum enzymes, after 24 and 48 h and a significant reduction of serum cardiac iso‐enzymes after 48 h. Also restoration of the white blood cell counts as well as hemoglobin concentration occured after 72 h of captopril adminstration. These results suggest that captopril may be benificial as a protective agent against cardio‐and hematotoxicity induced by adriamycin.
Enhancement by copper, zinc superoxide dismutase of DNA damage and mutagenicity with hydrogen peroxide
Authors: Kim Ryoung Hyo , Lee Su Min , Park Jeen‐Woo 
Published: July 2007

AbstractOxidative DNA damage caused by hydrogen peroxide was enhanced by copper, zinc superoxide dismutase (CuZnSOD) in a concentration‐dependent manner, as reflected by the formation of 8‐hydroxy‐2′‐deoxyguanosine (8‐OH‐dG) and strand breaks. Hydroxyl radical scavengers such as sodium azide, mannitol and 5,5‐dimethyl‐l‐pyrroline N‐oxide (DMPO), a metal chelator, diethyenetriamine‐ pentaacetic acid, and catalase decreased strand breaks and 8‐OH‐dG formation in DNA. The deoxyribose assay showed that hydroxyl free radicals were generated in the reaction of CuZnSOD with H2O2. CuZnSOD also caused enhancement of mutation in the pUC18 lacZ' gene in the presence of H2O2 when measured as a loss of a‐complementation. Based on these results, we interpret the effects of CuZnSOD on hydrogen peroxide induced DNA damage and mutation as due to reactive oxygen species, probably hydroxyl free radicals, formed predominantly by the reaction of hydrogen peroxide and free Cu2+ released from oxidatively damaged CuZnSOD.
RGD‐containing trypsin with both platelet aggregation inhibitory activity and proteolytic activity
Authors: Nie Xin , Tang Jian‐Guo 
Published: July 2007

AbstractArg‐Gly‐Asp (RGD) motif mediates cell adhesion as a major determinant in interactions of disintegrins with cell surface receptors. In order to obtain a mutant trypsin with both high affinity to integrins and retained proteolytic activity, RGDS and RGD were inserted into a rigid tuna region and a flexible loop of trypsin, respectively. Wild type trypsin and substituted mutant trypsins, 37RGDS and 77RGD, were expressed in E. coli and purified. Kinetic properties, autolytic stability as well as platelet aggregation inhibitory activity of both 37RGDS and 77RGD were determined. 37RGDS and 77RGD give retained proteolytic activities of 34% and 87%, respectively, and both become less stable to autolysis. 37RGDS shows an obvious inhibition rate of 29% for platelet aggregation and 77RGD gives a rather weak rate of 14% at the same protein concentration of 3.5 μM, while the wild type trypsin shows no inhibitory activity.
Reduced level of ATF is correlated with transcriptional repression of DNA topoisomerase IIα gene during TPA‐induced differentiation of HL‐60 cells
Authors: Lim Kyu , Lee Jong‐In , Yun Kyung‐Ah , Son Mee‐Young , Park Jong‐Il , Yoon Wan‐Hee , Hwang Byung‐Doo 
Published: July 2007

AbstractDNA topoisomerase II is a marker for the proliferation state of mammalian cells in culture, and the protein levels are markedly higher in exponentially growing cells than quiescent cells and can be downregulated by growth of the cells at high density and serum starvation. Correlation between ATF and TPA‐repressed DNA topoisomerase IIα (Topo IIα) mRNA has been investigated during TPA‐induced differentiation of HL‐60 cells. Topo IIα RNA and unknotting activity were reduced at 24 hours in TPA‐treated HL‐60 cells. The level of Topo IIα mRNA and the activity were gradually decreased in proportion to the concentration of TPA. Two DNA‐protein complexes were formed by DNA mobility shift assay when ATF‐binding site was incubated with nuclear extract prepared from TPA‐free HL‐60 cells, and the amount of ATF was vanished after TPA treatment. TPA‐repressed Topo IIα mRNA and ATF levels were partially restored after pretreatment of staurosporin. These results suggest that the reduced level of ATF may be important to the transcriptional repression of Topo IIα gene during TPA‐induced differentiation in HL‐60 cells and related to protein kinase C signal pathway.
Alloxan diabetes regulates adenosine deaminase activity in mice: tissue‐ and age‐ specific correlation
Authors: Singh L. Shanjukumar , Sharma Ramesh 
Published: July 2007

AbstractEffect of alloxan induced diabetes on the activity of adenosine deaminase (ADA) was studied in the liver, spleen, stomach and small intestine of mice at two different postnatal ages (preweaned, 15‐day and postweaned, 60‐day). Alloxan significantly stimulates (133%) ADA activity in the liver of 15‐day old mice, while it has no significant effect in the 60‐day old animals. In contrast, ADA activity was moderately increased (25%) in spleen of both the ages. However, no significant influence of alloxan was observed on ADA activity of stomach at either age of mice. On the other hand, alloxan treatment increases (69%) intestinal ADA activity in 15‐day old mice, with no significant change in 60‐day old animals. Thus, alloxan diabetes increases ADA activity in an age‐ and tissue‐specific manner. Stimulation of ADA activity in diabetic mice might play role in immune and other metabolic dysfunctions in diabetic conditions.
Inhibitory effects by a submandibular gland extract on luteinizing hormone‐stimulated testosterone production by testicular cells
Authors: Koshika Shinri , Izukuri Kazuhito , Kato Yasumasa , Saito Shigeru , Hosaka Masahiko 
Published: July 2007

AbstractIn order to evaluate the role of the submandibular gland (SMG) on testosterone (T) production by the testis, primary cultured testicular cells were prepared from rats that had the submandibular gland surgically ablated (G‐) and control (sham operated) rats (S.O.) respectively. The cells were incubated with or without 100 ng/ml luteinizing hormone (LH) and/or SMG extract. The same linear increase in T secretion was shown by both S.O.G‐ cells on multi‐stimulation with LH for up to 96 hrs. However, while an equivalent response was shown for S.O. cells after a single LH stimulation at 96 hrs, T secretion by the G‐ cells reached a plateau after 24 hrs. The level at 96 hrs was thus approximate 30% and 33% of those of S.O. cells with and without multi‐stimulus by LH for 96 hrs, respectively. When S.O. cells were cultured with SMG extract, LH‐stimulated T secretion was dose‐dependently inhibited and there was no effect on basal T secretion. The inhibitory effect was abolished by treatment at 95 °C for 5 min. Ultra‐filtration indicated that the molecular size of the inhibitory agent was greater than 30,000. It is proposed that SMG may contain a high molecular weight, heat labile soluble factor(s) which affects T secretion by inhibiting LH action in testicular cells.
Identification of a carbohydrate‐binding site in physarum haemagglutinin I
Authors: Morita Masashi , Iwado Yukiko , Okamura Shoji 
Published: July 2007

AbstractCarbohydrate‐binding peptides from trypsin‐digests of Physarum lectins (haemagglutinins I and II) were isolated by affinity column chromatography. The amino acid sequence of the peptlde fragment from haemagglutinin I was determined to be 48TVHQSWY54. A similar amino acid sequence was found in the peptide fragment from haemagglutinin II, in which alignment of valine, histidine, tryptophan and tyrosine was identical. Deletion of the heptapeptide sequence (TVHQSWY) by site‐directed mutation abolished the haemagglutinating activity. The replacement of Trp53 by alanine resulted in a complete loss of the haemagglutinating activity, suggesting that the tryptophan residue in the heptapeptide sequence is essential for carbohydrate binding.
The expressed α domain of mouse metallothionein‐I from Escherichia coli displays independent structure and function
Authors: Xiong Yi , Chen Yiwu , Ru Binggen 
Published: July 2007

AbstractThe α domain of mouse metallothionein‐I (mMT‐I) was expressed in E. coli as a C‐terminus of the 26 KD glutathione‐S‐transferase and purified from the cell lysates. The amino acid composition and molecular weight of the expressed protein are as expected. The metal‐binding stoichimetry was determined to show that divalent metals bind to the expressed α domain at the desired ratio of 4:1. The ultraviolet absorbance, circular dichroism spectra and the atomic force microscopy indicate that it can form the proper metal‐thiolate structure as in the whole MT molecule. The apparent affinity of the expressed α domain to bind cadmium is 1.8‐fold stronger than the recombinant mMT‐I when detected by the reaction with DTNB. The ability to scavenge hydroxyl free radicals remains higher than the whole MT molecule. All the results demonstrate that the expressed α‐domain from E. coli exhibits independent biochemical and physiological structure/function without the assistance of β domain.
Quenching of chlorophyll fluorescence by quinones
Authors: Samuilov Vitaly D. , Borisov Alexander Yu. , Barsky Eugene L. , Borisova Olga F. , Kitashov Andrei V. 
Published: July 2007

AbstractQuinones caused quenching of Chl a fluorescence in native and model systems. Menadione quenched twofold the fluorescence of Chl a and BChl a in pea chloroplasts, chromatophores of purple bacteria, and liposomes at concentrations of 50‐80 μM. To obtain twofold quenching in Triton X‐100 micelles and in ethanol, the addition of 1.3 mM and 11 mM menadione was required, respectively. A proportional decrease in the lifetime and yield of Chl a fluorescence in chloroplasts, observed as the menadione concentration increased, is indicative of the efficient excitation energy transfer from bulk Chl to menadione. The decrease in the lifetime and yield of fluorescence was close to proportional in liposomes, but not in detergent micelles. The insensitivity of the menadione quenching effect to DCMU in chloroplasts, and similarity of its action in chloroplasts and liposomes indicate that menadione in chloroplasts interacts with antenna Chl, i. e., nonphotochemical quenching of fluorescence occurs.
Chromium levels in patients with internal diseases
Authors: Zima T. , Mestek O. , Tesar V. , Tesarová P. , Nemecek K. , Zák A. , Zeman M. 
Published: July 2007

AbstractChromium (Cr), an essential element, mainly affects saccharide (potentiated insulin action via interaction with insulin receptor on the cell surface) and lipid metabolism (inhibition of hydroxymethylglutaryl‐CoA reductase with a hypolipidemic effect). The aim of the study was to describe Cr serum levels in different diseases (malignant, metabolic, renal) using an advanced analytical technique with correlation to other biochemical parameters. The concentration was measured using atomic absorption spectrometry with electrothermal atomization.The Cr levels were increased in hemodialysis patients ‐ HD (3.67± 0.35 μg/L) compared to controls ‐ C (0.40±0.12 μg/L), in significantly changed in diabetic patients ‐ DM (0.29±0.08 μg/L) and patients with lymphoproliferative disease ‐ LP (0.24±0.07 μg/L), and decreased in hyperlipidemic patients ‐ HL (0.15±0.03 μg/L). There were no differences in Cr concentration between DM treated by diet or peroral antidiabetic drugs; likewise hypolipidemic drugs in HL did not change the Cr concentration. The biochemical parameters ‐ total protein, transferrin in LP group, glucose in DM group, total cholesterol, triacylglycerols, LDL‐cholesterol, apolipoprotein B and A‐I did not correlate with serum Cr concentration. However, the HDL‐cholesterol concentration marginally significantly (p < 0.07) correlated with it. The role of Cr in humans has not yet been fully characterized. To prevent some complications in patients, it may be important to monitor the Cr levels. Chromium supplementation may be indicated in some diseases with no controversy concerning the importance of decreased serum and/or tissue levels and documented positive effects of Cr supplementation on the quality of life (e.g. hyperlipidemia).
Cholesterol sulfate induces changes in human erythrocyte thermostability
Authors: Przybylska Maria , Faber Miłosz , Zaborowski Andrzej , Bryszewska Maria 
Published: July 2007

AbstractThe influence of cholesterol sulfate (CS) on human red blood cell thermosensitivity was studied by flow cytometry and scanning electron microscopy. It was found that the effect of this sterol on erythrocyte stability is biphasic. Exposure of red blood cells (RBC) to the elevated temperature (51°C) induced perturbation of the cell membrane and led to haemolysis. Preincubation of cells with CS at a concentration of 1 × 10‐5 M protected them, to a certain extent, against lysis. In contrast, enrichment of RBCs with CS during the incubation with lower (0.4 × 10‐5 M) or higher (4‐8 × 10‐5 M) CS concentrations substantially augmented the fragility of the cells. The fact, that at the sublytic concentrations CS stabilises the cell membrane, may be explained by the ability of this amphipathic compound to link hydrophilic and lipophilic domains of the cell membrane and to increase the degree of the lipid bilayer order. Higher CS concentrations cause cell lysis in a detergent‐like manner. Our data support the conclusion that CS can be considered to be a potent thermosensitizer, which enhances the selectivity of biological drug carriers.
Fusion expression of human pro‐urokinase with E. coli thioredoxin
Authors: Sun Ai‐Long , Hua Zi‐Chu , Yao Ju , Yang Yong‐Hua , Yin Da‐Qiang 
Published: July 2007

AbstractHuman pro‐urokinase (pro‐UK) was cloned into plasmid pET32b and fused to the E. coli thioredoxin (trxA). When expressed in E. coli AD494(DE3), the fusion protein Trx‐pro‐UK accumulated as insoluble inclusion bodies and amounted to 35% of total cellular proteins. When co‐expressed with molecular chaperones human protein disulfide isomerase (PDI) and E. coli GroESL, all the expressed products still existed in the form of insoluble inclusion bodies.