bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of NF‐κB/Rel nuclear translocation by dexamethasone: Mechanism for the inhibition of iNOS gene expression
Authors: Jeon Young Jin , Han Seung Hyun , Lee Yong Woo , Yea Sung Su , Yang Kyu‐Hwan
Published: July 2007

The decrease in NO production was found to correlate well with a decrease in inducible nitric oxide synthase (iNOS) mRNA expression as demonstrated by Northern blot analysis and quantitative RT‐PCR. Since the promoter in iNOS gene contains binding motifs for NF‐κB/Rel, NF‐IL6, and Oct which appear to be important for LPS‐mediated iNOS induction, the effects of DEX on the activation of these transcription factors were examined. Treatment of DEX to RAW 264.7 cells induced a dose‐related inhibition of NF‐κB/Rel in chloramphenicol acetyltransferase activity, while NF‐IL6 or Oct activation was not affected by DEX. Treatment of RAW 264.7 cells with DEX inhibited DNA binding of NF‐κB/Rel proteins to their cognate DNA site as measured by electrophoretic mobility shift assay. In addition, DEX treatment caused a significant reduction in nuclear c‐rel, p65, and p50 protein contents, and these decreases were paralleled by the accumulation of cytoplasmic c‐rel, p65, and p50. These results suggest that DEX may inhibit iNOS gene expression by a mechanism involving the blockade of LPS‐induced nuclear translocation of NF‐κB/Rel.
Production and purification of an extracellular cellulase from Bacillus brevis vs‐1
Authors: Singh Vinay K. , Kumar Anil
Published: July 2007

A bacteria identified as Bacillus brevis has been isolated from the soil. It has been found to secrete cellulase extracellularly whose production increased almost five times on addition of galactose in the culture medium. Production of cellulase has been found optimal at pH 5.5, 37°C and 175 rpm speed using environmental orbital shaker. The cellulase has been purified using ultrafiltration and Sephadex G‐200 column chromatography. The native molecular weight of the enzyme is found to be 33,000±2000 using Sephadex G‐200 gel filtration chromatography. The subunit molecular weight (33,000±2,000) indicate monomeric nature of the enzyme. The enzyme showed Michaelis Menten kinetics exhibiting Km ≈︁1.7±0.1 mg/ml for CMC. The enzyme activity got inhibited by heavy metals viz. Hg+2 and Ag+2
Immunological studies on DNA‐lysine photoadduct
Authors: Islam Najmul , Ali Rashid
Published: July 2007

Calf thymus native DNA was covalently linked with lysine by irradiation with 254 nm light. Thermal melting studies indicated a decrease of 16°C in the Tm of DNA‐lysine photoadduct over native DNA. The decrease in Tm was dependent of irradiation dose. The photoadduct was found to be a potent immunogen in experimental animal. Thymine‐lysine photoconjugate in DNA‐lysine photo‐monoadduct appears to be the major immunodominant portion. A strong recognition of DNA‐lysine photoadduct was observed with anti‐DNA autoantibodies found in the sera of patients with SLE. Thymine‐lysine conjugate in DNA‐lysine photo‐monoadduct appears to provide an immunodominant epitope(s) for SLE autoantibody recognition. The results suggests for the possible involvement of DNA‐lysine photoadduct or similar modified structure(s) as a potential trigger for anti‐DNA autoantibody production.
Comparison of inactivation and conformational changes of native and apo yeast alcohol dehydrogenase during thermal denaturation
Authors: Yang Yi , Chen Rong , Zhou Hai‐Meng
Published: July 2007

The conformational changes of native and apo yeast alcohol dehydrogenase during thermal denaturation have been followed by fluorescence emission and circular dichroism spectra. A comparison of inactivation and conformational changes during thermal denaturation shows that for the native enzyme and for the apo‐I YADH which has the conformational zinc removed, the extent of inactivation was larger than the extent of conformational changes at the same temperature. This result supported the suggestion by Tsou (Trends Biochem. Sci. 1986, 11, 427‐429: Science 1993, 262, 380‐381) that the enzyme active site is more flexible. The results also show that apo‐I YADH without the conformational zinc was more easily inactivated with increasing incubation temperature, indicating that the stability of the apo‐I YADH decreased. Kinetic analysis suggest that the substrate does not provide any protective effect during thermal inactivation of native and apo‐I YADH.
Binding of naturally occurring anti‐DNA antibodies to estradiol
Authors: Ali Asif
Published: July 2007

Binding of naturally occurring human anti‐DNA autoantibodies to β‐estradiol and native DNA has been investigated. Sera from seven SLE patients were tested for their reactivity with β‐estradiol and native calf thymus DNA. Solid Phase enzyme immunoassay was performed using both colorigenic and fluorogenic substrates. The results show enhanced binding of human anti‐ DNA autoantibodies to β‐estradiol as compared to native DNA. This was further substantiated by increased binding of affinity purified SLE IgG to β‐estradiol. These results suggest a role for female sex hormone in the etiopathogenesis of SLE and are significant vis‐a‐vis female predominance of SLE.
Modulation of erythrocyte photohemolysis rate by glutathione reductase inactivating alkylating agents
Authors: Kersene Regina , Maroziene Audrone , Kliukiene Regina , Anusevicius Zilvinas , DidZiapctriene Janina , Cenas Narimantas
Published: July 2007

In order to determine the rote of glutathione reductase (GR) in protection against AI‐phtalocyanine tetrasulfonate‐sensitized human erythrocyte photolysis, we have studied the effects of antitumour alkylating agents that inactivate GR, on photohemolysis rate. The rates of inactivation of reduced GR decreased in order BCNU > pharanox (N‐p‐[bis‐(2‐chloroethyl)‐amino]‐phe‐nylacetic acid N‐oxide) > phenalol (N‐p‐[bis‐(2‐chloroethyl)‐amino]‐phenylacetyl‐L‐phenylalanine) > o‐F‐ and p‐F‐lophenal (o‐ and p‐isomers of N‐p‐[bis‐(2‐chloroethyl)‐amino]‐phenylacetyl‐D,L‐fluorophenylalanine) > D,L‐melphalan. As supposed, erythrocyte photolysis was accelerated by BCNU and pharanox, however, it was slowed down by phenylalanine mustards. The latter effect was explained by singlet oxygen quenching and/or photooxidation reactions of these compounds. This points out to a possibility of certain phenylalanine derivatives to neutralize the side‐effects of photodynamic therapy.
Effects of D‐glucose and starvation upon the cyclic ADP‐ribose content of rat pancreatic islets
Authors: Scruel O. , Wada T. , Kontani K. , Sener A. , Katada T. , Malaisse W. J.
Published: July 2007

Rat pancreatic islets were found to display a much lower content of immunoreactive CD38 and a much lower ADP‐ribosyl cyclase activity than rat spleen or brain. Cyclic ADP‐ribose was also measured by a radioimmunological procedure in rat pancreatic islets. In fed rats, the cyclic ADP‐ribose content appeared higher after isolation of the islets in the presence of 2.8 mM D‐glucose rather than in the absence of the hexose, progressively increased during incubation of the islets for 5‐60 min at 37°C, but failed to be affected by the concentration of D‐glucose (zero to 20.0 mM) in the incubation medium. In rats fasted for 24 hours, the cyclic ADP‐ribose islet content also increased during incubation, but again failed to be affected by the concentration of D‐glucose in the incubation medium. Although these findings indicate that the islet cyclic ADP‐ribose content is influenced by nutritional and environmental factors, they do not support the view that the insulinotropic aciton of D‐glucose involves major change in the islet cell content of the cyclic nucleotide.
Purification and partial characterization of cathepsin D from porcine (Sus scrofa) liver using affinity chromatography
Authors: Canduri Femanda , Ward Richard J. , de Azevedo Walter F. , Gomes Roseli A. S. , Arni R. K.
Published: July 2007

Cathepsin D, a lysosomal aspartic protease, has been purified from porcine liver using a combination of pepstatin‐A agarose and Affi‐Gel Blue affinity chromatography, followed by size‐exelusion chromatography. The purified protein consists of two polypeptide chains of 15 and 30 kDa, and has an isoelectric point of 6.8. Porcine fiver cathepsin D has maximum activity at pH 2.5‐3.0 as determined by its activity against hemoglobin, with a Kcat of 14.3 s‐1 and a kcat/KM of 2.70×106 s‐1M‐1 as determined by the hydrolysis of a fluorogenic peptide substrate.
Interaction of sodium bis(2‐ethylhexyljt) sulfosuccinate (AOT) with catalase and horseradish peroxidase in an aqueous solution and in the reverse micelles of AOT/n‐heptane
Authors: Gębicka Lidia , Gębicki Jerzy L.
Published: July 2007

Some properties of catalase and horseradish peroxidase entrapped into reverse micelles of sodium bis(2‐ethylhexyl) sulfosuccinate (AOT)/n‐heptane with those in an aqueous solution of AOT are compared. Secondary structure of catalase significantly changes and activity is completely lost in the presence of aqueous micellar solution of AOT. In AOT/n‐heptane reverse micelles secondary structure of catalase does not change. AOT has no effect on horseradish peroxidase in aqueous solution. On the other hand slight changes in secondary structure of horseradish peroxidase in AOT/n‐heptane reverse micelles appear. It is concluded that electrostatic interactions between catalase or horseradish peroxidase with AOT molecule at neutral pH are not the main factor determining reactivity of investigated enzymes in reverse micelles.
Effect of seasonal acclimatization on the expresion of the carp transcription factor Pit‐1
Authors: Kausel Gudrun , Vera María Inés , Figueroa Jaime , Hernández Jaime , Martin Rody San , Molina Alfredo , Chavez Viviana Marcela , Muller Marc , Martial Joseph , Krauskopf Manuel
Published: July 2007

We isolated a clone comprising four exons of the carp Pit‐1 gene. Using synthetic oligonucleotide probes derived from the carp Pit‐1 sequence Pit‐1 expression was assessed by in situ hybridization in pituitary sections from summer‐ and winter‐acclimatized carp. Semiquantitative analyses of the hybridization signals revealed a significant higher Pit‐1 expression in the proximal pars distalis (PPD) and pars intermedia (PI) of the pituitary glands from summer‐acclimatized carp, compared to the winter‐acclimatized fish. In both adaptive states, relative to the PPD and PI, only a basal Pit‐1 expression was detected in the rostral pars distalis. Thus, during seasonal acclimatization of an eurythermal fish, Pit‐1 seems to be involved in the mechanisms that underlie the compensatory response.
A human B cell line AF10 expressing hIL‐17
Authors: Zhou Limei , Peng Shanyun , Duan Jubao , Zhou Jing , Wang Lihong , Wang Jiaxi
Published: July 2007

AF10, a human B cell line, is a mycoplasma‐free variant cloned from the human IgE myeloma cell line U266. Total RNA isolated from the AF10 cells was used as template for RT‐PCR, and a specific product of about 411bp corresponding to the coding region of hIL‐17 lack of a leading sequence obtained. The sequence of the RT‐PCR product is the same to that reported in the literature. The expressed rhIL‐17 in E. coli can induce 10‐ to 15‐fold increase of IL‐6 secretion by mouse fibroblast 3T3 cells. It is for the first time until now that hIL‐17 messager has been detected in B cell. There may exist some potential relationship between hIL‐17 and myeloma cells.
Hepatic and renal metallothionein induction following single oral administration of gallium arsenide in rats
Authors: Flora Swaran J. S. , Tripathi Neelima
Published: July 2007

Metallothionein genes (MT) are inducible by a variety of agents, including heavy metals. We report the induction of MT expression by gallium arsenide (GaAs), a superior intermetallic semiconductor material at two time intervals following single oral exposure in rats. The data is also supplemented with two additional groups exposed to gallium (III) as gallium oxide and arsenic (III) as sodium arsenite to determine which of the two moieties in GaAs is responsible for any such possible effects. The results indicate that GaAs administration does significantly induces MT in hepatic tissues accompanied by an increase in cytosolic glutathione, arsenic, zinc and copper concentration. It thus proves that arsenic moiety is chiefly responsible for such an effect.
Effect of cholesterol/phosholipid ratio on stimulatory GTP‐binding protein function
Authors: Bai Luo , Youguo Huang
Published: July 2007

The effect of different cholesterol/phospholipid (C/P) ratios on the coupling function between stimulatory GTP‐binding protein(Gs) and adenylyl cyclase (AC) in proteoliposomes, and its relationship to the conformational change of Gs were investigated. The results showed that Gs activities of both binding GTPTγS and stimulating adenylyl cyclase were the highest in proteoliposomes with a proper content of cholesterol similar to physiological situation while the lowest with higher cholesterol content similar to pathological situation. In addition, the conformational change of Gs in proteoliposomes was also detected by steady‐state and nanosecond time‐resolved fluorescence using acrylodan as a probe. It is suggested that a proper C/P ratio similar to physiological situation regulates the function of Gs by inducing a change in the physical state of lipid bilayer, which would favor the formation of a suitable conformation of Gs with higher activities of both binding GTP and stimulating adenylyl cyclase. But if C/P ratio is higher, such as in pathological situation, this is unfavorable for motion of Gs in membrane, which results in inhibition of Gs function significantly.
Monoclonal antibodies directed against lipopolysaccharide of legionella pneumophila serogroup 1
Authors: Baranov A. M. , Vetchinin S. S. , Baranova E. V. , Biketov S. F. , Svetoch E. A.
Published: July 2007

The monoclonal antibodies (MAbs) against lipopolysaccharide of virulent strain of Legionella pneumophila serogroup 1 were produced. Three most productive hybrid clones (5F4, 5F10 and 2C9) were selected from fusions of mouse myeloma cells with spleen cells from BALB/c mice, immunized with bacterial outer membrane antigens. All generated clones were IgG‐secreting. The MAbs had narrow strain specificity mad showed no cross‐reactions with other unrelated bacterial species. These antibodies were tested in sandwich ELISA. The results suggest that the MAbs could be used for diagnostic purposes.
The effect of interferon therapy on erythrocyte membrane Na, K ATP activity in patients with chronic hepatitis B and C virus infections
Authors: Kuralay Filiz , Tanyalçin Tijen , Kutay Fatma , Ersöz Galip , Yüce Gül , Batur Yücel
Published: July 2007

In order to evaluate the effect of alpha interferon on erythrocyte membrane Na+, K+ ATPase (EC 3.6.1.37) activity, 10 patients with chronic hepatitis B virus (HBV) infection and 8 patients with chronic hepatitis C virus (HCV) infection were investigated. Erythrocyte membrane Na+, K+ ATPase activity was determined in controls and in patients with HBV and HCV infection. Na+, K+ ATPase activity was significantly less in untreated patients with (HBV) infection (n=20; 0,134±0,073 μmol of phosphate produced per milligram of protein per hour) and (HCV) infection (n=11; 0,144±0,049) when compared to the controls (n=10; 0,219±0,055). Among these subjects patients were treated with interferon and following treatment, significant elevation of Na+, K ATPase activity was seen in patients with HCV (n=8; 0,183±0,044; P=0,049) and HBV (n=10, 0,213±0,095, P=0,0069) infections when compared with the pre‐treatment values (n=8; 0,152±0,050) and (n=10, 0,131±0,083), respectively. Normalization of serum alanin amino transferase levels (ALT) at treatment cessation was seen in 8 of 10 (%80) HBV infected patients of whom 2 of 8 (%25) had sustained ALT responses within three months after the end of treatment. In HCV infected patients 1 of 8 (%12,5) had sustained response following treatment. At the end of treatment, although Na+, K+ ATPase was restored in both of the patients groups, relative changes in enzyme activity in relation to relative reduction in ALT levels as a response to IFN therapy were not correlated.
A comparative study by a single chromatographic procedure of glycolytic regulatory kinase isozymes in rat erythroid cells as a function of differentiation‐maturation process
Authors: Jimeno Pilar , Luque José , García‐Pérez Ana I. , Pinilla Montserrat
Published: July 2007

The isozymes of three glycolytic regulatory kinases: hexokinase, phosphofructokinase and pyruvate kinase are fractionated by a single ion exchange chromatographic procedure on DEAE‐cellulose. Enriched‐erythroblast bone marrow cells showed two heterogeneous peaks, each consisting of two overlapping peaks: one major and one minor peak, but only two isozymes were observed in reticulocytes and erythrocytes. Phosphofructokinase showed multiple isozymic forms in the three cell populations, but while in erythroblasts the main one eluted in the last fractions, in reticulocytes and erythrocytes it eluted in the early fractions. Pyruvate kinase showed a main early activity peak with a shoulder in erythroblasts, reticulocytes and erythrocytes but the response to the allosteric effectors (fructose‐1,6‐bisphosphate and ATP) suggests the presence of different pyruvate kinase isozymes in reticulocytes and erythrocytes.
5‐Azacytidine modulates γ‐glutamyltransferase and glutathione levels in two human prostatic adenocarcinoma cell lines
Authors: Yaagoubi M. El , Visvikis A. , Khalid A. , Siest G. , Wellman M.
Published: July 2007

Two human prostate adenocarcinoma cell lines, LNCaP and PC‐3, were used to study the effect of 5‐azacytidine on GGT gene expression, via genomic DNA methylation, and GSH content. When the cells were treated with 5‐azaC, the specific GGT activity increased in a dose and time‐dependent manner and was accompanied by the elevation of intracellular glutathione content. Southern blot analysis of DNA digested with MspI or HpaII showed negative correlation between the methylation pattern of GGT DNA and GGT activity, either in control or 5‐azaC treated cells. Reverse transcription‐polymerase chain reaction (RT‐PCR) analysis revealed that GGT mRNA types I are expressed and induced in a cell type‐specific manner in control and 5‐azacC treated cells respectively. Overall, our investigations suggest that DNA methylation and other mechanisms combine to regulate GGT gene expression in studied prostate adenocarcinoma derived cells.
Cooperative and differential effects of estrogen, prolactin, 22K and 20K human growth hormones on cyclin D1/PRAD1 gene expression in T‐47D human breast cancer cells
Authors: Kaneko Hiroshi , Fujikawa Takahiko , Alam Khorshed S. M. , Kaneko Satoshi , Tanaka Minoru , Hibasami Hiroshige , Nakashima Kunio
Published: July 2007

The cyclin D1/PRAD1 gene is correlated with carcinogenesis of human breast cancer. In this study, we have analyzed effects of breast cancer‐related hormones on the cyclin D1 gene expression in T‐47D human breast cancer cells. Estradiol (E2) and human prolactin (hPRL) equally enhanced the cyclin D1 gene expression in the cells, and 22 and 20 kDa human growth hormones (22K and 20K hGHs) showed less stimulatory effects. In the presence of E2, however, hPRL or 22K hGH showed additive stimulations of the cyclin D1 gene expression to that by E2 alone, while 20K hGH did not show any additive stimulation of the gene expression. The results suggest that the signal pathways through estrogen and hPRL receptors are important for cyclin D1 gene expression in breast cancer cells, and that 20K hGH has little effect on the cyclin D1 gene expression in these cells because of its lower affinity to PRL receptor.
Study of the influence of salt concentration on Newcastle disease virus matrix protein aggregation
Authors: Sagrera Ana , Cobaleda César , Berger Sylvia , Marcos María José , Shnyrov Valery , Villar Enrique
Published: July 2007

The aggregation process of Newcastle disease virus matrix protein (M protein) has been studied using light scattering. We observed that the aggregation of M protein is inversely correlated with ionic strength and that this process can be reversed by high salt concentrations. It was found that the oligomeric structure of NDV matrix protein is different from those described earlier for other matrix proteins of enveloped viruses
Antiidiotypic antibody to gonadotropin releasing hormone as probe for cell surface receptors
Authors: Karande Anjali A. , Rajeshwari Krishnamurthy , Padmanaban Deepa , Ravichandra Balijepalli , Joshi Preeti G. , Yadav Poonam , Shobha Prahlad
Published: July 2007

Monoclonal antibodies were raised to the idiotype of a gonadotropin releasing hormone (GnRH) specific antibody, one of which was found to bind specifically to GnRH receptors present on pituitary gonadotrophs, placental syncytiotrophoblasts and testicular Leydig cells. These observations were confirmed by Western and ligand blotting as well as by the ability of the antibody to induce an increase in intracellular Ca++ in a mouse gonadotroph cell‐line viz., αT3‐1.
Dietary fats alter the activity and expression of glucose‐6‐phosphate dehydrogenase in rat lymphoid cells and tissues
Authors: Otton Rosemari , Graziola Fabiana , Hirata Mário H. , Curi Rui , Williams John F.
Published: July 2007

The effect of diets enriched with fat containing different fatty acids on the activity and expression of the glucose‐6‐phosphate dehydrogenase (EC 1.1.1.49) of mesenteric lymph nodes, lymphocytes and intraperitoneal macrophages was examined. Measurements of the enzyme were also performed using spleen, thymus and liver for comparison. The following fat rich diets containing a variety of fatty acids were used: 1‐standard chow (CC); 2‐medium chain saturated fatty acids (MS)‐cocconut fat‐oil; 3‐long chain saturated fatty acids (LS)‐cocoa butter; 4‐monounsaturated fatty acids (MU)‐canota oil (n‐9); 5‐polyunsaturated fatty acids (PU)‐soybean oil (n‐6). Of the fat‐rich diets tested, MS had the least effect. The G6PDH activity of lymphocytes was reduced by all the fat‐rich diets; 16% for MS, 38% for LS, and 54% for MU. Similarly, the enzyme activity was reduced in macrophages; 35%, 86%, and 73%, for LS, MU, and PU. respectively. In contrast, the fat‐rich diets elevated G6PDH activity in the lymphoid organs; by 42% in the spleen due to LS and by 131%, 35%, and 56% in the thymus due to LS, MU, and PU, respectively. Fat‐rich diets decreased the activity of G6PDH in liver: 42%, 68%, and 39% for MS, MU, and PU, respectively. Some of the changes in G6PDH activity induced by the fat‐rich diets occur through the mechanisms of mRNA abundance.
DNase I hypersensitive Sites in the chromatin of the chicken Msx2 gene differ in anterior and posterior lim mesenchyme, calvarial osteoblasts and embryonic fibroblasts
Authors: Pan ZhongZong , Lichtler Alexander C. , Upholt William B.
Published: July 2007

To identify candidate cis‐acting regulatory regions involved in regulation of the Msx2 gene in anterior limb mesenchyme and calvarial osteoblasts, DNase I hypersensitive sites (DHSs) from ‐6.1 kb to +8.4 kb relative to the translation start site of the chicken Msx2 gene were identified in anterior and posterior limb mesenchyme, calvarial osteoblasts, and embryonic fibroblasts. A total of 12 DHSs were detected. Except for the DHS in the basal promoter region, none of the other DHSs were present in all four tissues, suggesting that the chromatin structure in the Msx2 gene locus is differently organized in these four cell types. One DHS was unique to Msx2 expressing cells and a second site to nonexpressing cells. Anterior and posterior limb mesenchyme had similar patterns of DHSs that were much more complex than observed in catvarial osteoblasts possibly reflecting differences in the complexity of Msx2 regulation in these two tissues.
Effect of aminoguanidine on lipid peroxidation and activities of antioxidant enzymes in the diabetic kidney
Authors: Kędziora‐Kornatowska K. , Luciak M.
Published: July 2007

The aim of this study was to examine lipid peroxidation and activities of key antioxidant enzymes in kidneys of rats with streptozotocin (STZ)‐induced diabetes and the effect of aminoguanidine on diabetes‐induced alterations. Three groups, 6 rats each, were studied: control animals, not treated diabetic rats and rats treated with aminoguanidine (AG; 1 g/liter of drinking water). After 6 and 12 weeks the animals were sacrificed and lipid peroxidation products and activities of antioxidant enzymes were determined in their kidney homogenates. Malondialdehyde (MDA) content was significantly elevated and activities of SOD and catalase decreased in the kidneys of STZ‐diabetic rats. AG treatment attenuated the increase in MDA content and diminutions of activities of SOD and catalase in the kidneys of diabetic rats. These results confirm oxidative stress in the kidney of rats with STZ diabetes and point to an antioxidant effect of AG in experimental diabetes.
Role of DNA definite structural elements in interaction with repair enzyme uracil‐DNA glycosylase
Authors: Kubareva Elena A. , Vasilenko Natalja L. , Vorobjeva Olga V. , Volkov Evgeny M. , Oretskaya Tatjana S. , Korshunova Galina A. , Nevinsky Georgy A.
Published: July 2007

Interaction of different oligodeoxyribonucleotides (oligos), their analogs and oligonucleopeptide with uracil‐DNA glycosylase (UDG) from human placenta was investigated. It is shown that there is no considerable contribution of heterocyclic bases of DNA to UDG‐substrate binding but the UDG interaction with some DNA phosphate groups is necessary for enzyme‐substrate recognition. However the phosphate group adjacent to single dU from the 3′‐end in oligo is not involved into the electrostatic contact with UDG. It is found that UDG has the high affinity to its reaction product. An oligonucleotide containing a single 2′‐deoxy‐2′‐aminouridine is a non‐hydrolyzable substrate analog for UDG.
The use of a chimera HIV‐1/HIV‐2 envelope protein for immunodiagosis of HIV infection: Its expression and purification in E. coli by use of a translation initiation site within HIV‐1 env gene
Authors: Han Baoguang , Song Xiaoguo , Chen Qun , Wang Hongyan , Ling Shigan
Published: July 2007

A chimera HIV‐1/HIV‐2 envelope sequence composed of multiple conserved immunodominant epitopes of HIV‐1 envlope protein (HIV‐1 IIIB: env482‐518+env548‐675) and the HIV‐2 gp36 immunodominant epitope (env592‐603), was constructed and directly over‐expressed in E. coli by using a prokaryotic translation initiation sequence contained within the gene of HIV‐1 envelope. The recombinant product was purified and applied in antibody‐screening assay. The purified chimera antigen reacted with all the thirty‐eight HIV‐1 positive serum samples, the two HIV‐2 serum samples, and had no cross‐reaction with all the eighty‐eight normal healthy serum sample. The results indicated that this recombinant chimera HIV‐1/HIV‐2 envelope protein could be useful for diagnostic purposes of HIV infection.
Three dimensional electron spin resonance (ESR) imaging of internal organs in living mice
Authors: Masumizu Toshiki , Fujii Kanae , Kohno Masahiro , Nagai Soichi , Odagaki Yuji , Imanari Mamoru , Mori Akitane , Packer Lester
Published: July 2007

In viva electron spin resonance imaging (ESR imaging) was applied to living mice after peroral administration of a nitroxide radical spin probe. A 3D ESR imaging procedure was applied in vivo in order to obtain the exact distribution of the spin probe in a living animal. The imaging pictures demonstrated that the administered spin probe was firstly located in the stomach, then delivered to the liver, kidney and heart of the animal.
Glucose‐ and phorbol ester‐induced insulin secretion in human insulinoma cells ‐ Association with protein kinase C activation‐
Authors: Miura Atsushi , Ishizuka Tatsuo , Itaya Satomi , Ishizawa Masayoshi , Kanoh Yoshinori , Kimura Mika , Kajita Kazuo , Yasuda Keigo
Published: July 2007

This study examined the effect of glucose and 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) on insulin secretion in isolated human insulinoma cells. In addition, we analyzed conventional PKCα and β activation in the membrane fractions, respectively. Treatment with 5 mM and 20 mM glucose for 5 min and 20 min resulted in 6∼7‐fold increases in insulin secretion, and treatment with 1 μM TPA for 5 min also resulted in 3‐fold increases in insulin secretion from the basal level. Immunoblot analysis of membrane fractions showed increases in PKCα and β immunoreactivities after treatment with 5 mM, 20 mM glucose and 1 μM TPA. Translocations of PKCα after treatment with glucose and TPA were greater than those of PKCβ in membrane fractions. These results suggest that TPA independently provokes insulin secretion via PKC activation and that PKCα and β activation may be involved in insulin secretion in human insulinoma cells.
Occurrence of bovine spleen CD38/NAD glycohydrolase disulfide‐linked dimers
Authors: Berruet Laure , Muller‐Steffner Hélène , Schuber Francis
Published: July 2007

Bovine spleen NAD+ glycohydrolase, an ecto‐enzyme closely related to CD38, catalyzes the conversion of NAD+ into ADP‐ribose and cyclic ADP‐ribose, a calcium‐mobilizing metabolite. We have raised polyclonal antibodies against the native enzyme which on immunoblots revealed, besides the 32 kDa monomer, the presence of a stable dimeric form. This dimerization was shown to result from a spontaneous oxidative process involving the formation of one or several disulfide bond(s) sensitive to reducing agents such as 2‐mercaptoethanol. The homodimeric oxidized enzyme, which was not detected during the early steps of the enzyme purification procedure, was catalytically active. Our results underline the differences, in terms of oligomerization and reactivity towards thiols, between CD38/NAD+ glycohydrolases depending on their origin.
A Mg2 ‐dependent endonuclease is responsible for internucleosomal DNA fragmentation in human B lymphoblastic IM9 cells
Authors: Kwon Hyung‐Joo , Kim Doo‐Sik
Published: July 2007

We have identified a Mg2+‐dependent endonuclease activity from human B lymphoblastic IM9 cell lysates and nuclei using autodigestion method and DNA‐native‐polyacrylamide gel electrophoresis (DNA‐native‐PAGE) nuclease assay system. The level of the endonuclease activity in cell lysates was significantly decreased at certain stage by treatment of the cells with cycloheximide. However, the enzyme activity consistently remained for over 12 hours in the isolated nuclei of the apoptotic IM9 cells. The Mg2+‐dependent endonuclease isolated from the nuclei by native‐PAGE elution was able to catalyze the conversion of supercoiled plasmid DNA into linear form. This particular endonuclease activity was not detected in cycloheximide treated‐U937 cells. Several lines of experimental evidence suggest that the Mg2+‐dependent endonuclease localized in the nucleus may be responsible for the DNA fragmentation of apoptotic IM9 cells.
Factors influencing the levels of fatty acid synthase complex activity in fowl
Authors: Li Mei , Shi Yan , Tian Weixi
Published: July 2007

There is a notable discrepancy between the FAS (fatty acid synthase) activity of four types of fowl (egg chicken, meat chicken, egg duck, and meat duck) with distinctively different body fat levels. There is a 14.8 fold difference per unit body weight between the maximum and minimum FAS activities. The three major factors affecting this discrepancy are liver weight per unit body weight, which is 2.3 times greater in meat ducks than in egg chickens, the amount of FAS protein per gram of liver. which is 1.85 times greater in meat ducks than in egg chickens, and the FAS specific activity in meat ducks, which is 3.5 times greater in meat ducks than in egg chickens. Within the same species of egg chickens, the abdomen fat per kg of body weight at 470 days after egg production is 66 times greater than 90 days before egg production and the liver FAS activity is increased 9.6 fold. The 9.6 fold FAS activity increase resulted from an increase in the specific activity, since the liver weight per kilogram of body weight remained constant at approx. 20 grams and the FAS weight per gram of liver also remained constant at approx. 4.5rag. This shows that the control of the basic FAS activity level which is closely related to the level of body fat does not mainly arise from genetic control. For the same kind of fowl, the control of the basic FAS activity level occurs after gene expression. It is suggested that control may be imposed in the folding phase when new peptides give rise to functional proteins.
Relationship between the physicochemical parameters and biological activity of sulfosuccinic and ester surfactants
Authors: Oros Gyula , Cserhàti Tibor , Vrbanovà Alena
Published: July 2007

The effect of 11 sulfosuccinic acid ester surfactants on the abiotrophic developmental forms of the asexual spores of Plasmopara halstedii was determined. The strength and the selectivity of the effect was separated by the spectral mapping technique and the relationship between the biological activities and physicochemical parameters of anionic surfactants was elucidated by stepwise regression analysis. It was established that the plasma‐lemma of cell wall less zoospores showed the highest and the resting zoosporangia the lowest average sensitivity toward the surfactants. The biological efficacy of surfactants was highly different the di‐n‐octyl ester being the most effective. Calculations proved that both the stregth and selectivity of the biological activity mainly depends on the lipophilicity of the molecule and, to a lesser extent, on the electronic parameters.
The polarization model in bacterial photosynthesis
Authors: Borisov A.Yu. , Fok M. V.
Published: July 2007

The widely accepted model of reaction center /RC/ functioning is proved to come into contradiction with some recent data. In particular, it cannot explain why only a minor part of electronic excitations (≈︁10%) escapes from excited RC special pairs back to antenna BChls. Therefore we believe that the model must be substantially modernized. In 1981 we developed a new model/1,2/. We suggested a femtosecond state to precede primary e‐transfer reaction due to reorientation of water molecule dipole in the electric field of excited RC dimer. This mechanism is responsible for energy trapping before the primary e‐transport occurs. During last years his mechanism got support from various experimental works. Now this polarization model claims to fit all reliable experimental data at least in bacterial photosynthesis.
Differential regulation of protooncogene c‐myc expression in rat ventral prostate after castration
Authors: Lee Joong‐Hwa , Sul Chong‐Koo , Kim Young‐Kyun , Hwang Byung‐Doo , Lim Kyu
Published: July 2007

To evaluate the possibility that the protooncogene c‐myc plays a role in ventral prostate, the effects of castration have been investigated at a beginning of a period by Northern blot hybridization and the levels of c‐myc mRNA were also compared with mRNA of androgen‐regulated genes, C1 and TRPM‐2. Levels of c‐myc mRNA in ventral prostate increased with maximal stimulation reached at 6 hours (early induction) and 48 hours (late induction) after castration, respectively. The level of C 1 mRNA did not change and TRPM‐2 was not detected at early induction of c‐myc mRNA after castration. The level of early induction of c‐myc mRNA after castration was increased in ventral prostate treated with cycloheximide, but it was almost reduced by actinomycin‐D pretreatment. Administration of androgen at the time of castration prevented early induction of c‐myc mRNA. These results suggest that protooncogene c‐myc is differentially regulated in ventral prostate after castration.
Pre‐conditioning to global cerebral ischemia changes hippocampal acetylcholinesterase in the rat
Authors: Schetinger Maria R. C. , Bonan Carla D. , Frassetto Silvana S. , Wyse Angela T. S. , Schierholt Rejane C. , Webber Analupe , Dias Renato D. , Sarkis Jaão J. F. , Netto Carlos A.
Published: July 2007

This study shows the effect of transient global cerebral ischemia (ISC) on hippocampal acetylcholinesterase (AChE) activity. Naive adult Wistar rats received either a brief (2 min) or a long (10 min) ischemic episode by the four‐vessel occlusion method. Pre‐conditioned rats received double ischemia: a 10 min episode inflicted 24 h after a 2 min event, a condition known to confer cytoprotection to CA1 pyramidal cells of hippocampus. 2 min of ischemia caused an increase in acetylcholinesterase activity both immediately and 30 min after the episode, however enzyme activity was significantly decreased after 24 h of reperfusion. 10 min of ischemia caused an increase in activity both 60 min and 24 h after ischemia. Conversely, pre‐conditioned rats displayed lower activity both immediately and 60 min after ischemia. Our results suggest that: a) neuronal death, that follows 10 min of ischemia, is associated to a late increase in acetylcholinesterase activity; b) pre‐conditioning is related to diminished acetylcholinesterase activity. This is in agreement with previous evidence that acetylcholinesterase inhibition and maintenance of acetylcholine levels are beneficial for cell surviving after cerebral ischemia.
Orthophosphate is a non‐essential activator of Vigna radiata flavokinase
Authors: Das‐Panja Kaberi , Jonnalagadda Vidya S. , Jonnalagadda Sobhanaditya
Published: July 2007

The ATP‐dependent phosphorylation of riboflavin to FMN by flavokinase from Vigna radiata was activated by orthophosphate (Pi) in a concentration dependent manner. Pi affected both the Km and Vmax, indicating that it is a non‐essential, mixed type activator. The extent of activation by Pi was dependent on the cation (Mg2+ or Zn2+). Activation by other anions could be correlated to similarity to Pi in molecular size and structure. These observations suggest the presence of a binding site(s) for a phosphate‐like anion on flavokinase.
Novel gelatinolytic activities in rat organs
Authors: Kubota Satoshi , Yokoyama Yoshihiro , Toyohara Haruhiko , Sakaguchi Morihiko
Published: July 2007

Novel gelatinolytic activities in both latent and active forms were detected in the normal organs of rat by gelatin zymography. Multiple active bands were detected in the extracts from the skin, jejunum, muscle, and kidney without any activation. These activities were inhibited by 1,10‐phenanthroline or leupeptin, nor by E64, suggesting that these activities were derived from metallo‐proteinases or serine‐proteinases. Some gelatinolytic active bands were newly induced or enhanced by p‐aminophenylmercuric acetate. These results suggest that matrix degrading activities due to metallo‐ and serine‐proteinases were constitutively expressed in various rat normal organs.
Comparison of enzymatic activities of the HIV‐1 and HFV integrases to their U5 LTR substrates
Authors: Oh You‐Take , Shin Cha‐Gyun
Published: July 2007

The human immunodeficiency virus type 1 (HIV‐1) and human foamy virus (HFV) integrase proteins were overexpressed in Escherichia coli, and purified to a near homogeneity by one‐ or two‐step purification scheme. The endonucleolytic, integration, and disintegration activities for the HIV‐1 and HFV integrases were characterized in vitro. The endonucleolytic activities for the HIV‐1 and HFV integrases were found only on their own substrates, respectively, indicating that the cognate U5 LTR sequences in the substrates is critical for specific cleavage. However, the integration and disintegration activities showed less specificity on the substrate usage. Our results suggest that the disintegration activity have more preference for substrates based on Y‐shaped structure rather than on viral donor DNA sequence.
Categorizing reactivity of bacteriorhodopsin cysteine mutants crosslinking to 4‐bromoretinal
Authors: Datta‐Gupta N. , Crouch Rosalie K. , Hazard E. Starr
Published: July 2007

The structure of bacteriorhodopsin (bR) has been probed by a large number of experimental methods. In earlier work distance constraints measured from the 1BRD Brookhaven structure (1, 2) were used to guide site‐directed mutagenesis/affinity labeling experiments (3‐5). In the present study we report on the use of limited molecular dynamics (MD) investigations of the same bR/affinity label system. We show here that the chiral center introduced when 4‐bromo‐all‐trans retinal is synthesized produces variable impact on potential crosslinking. Our MD analysis suggests the following ranking of binding site mutants in order of reactivity: R118C>S118C>> S121C>R141C>>S141C⋙R121C, R138C, S 138C. Chirality appears to have limited effect for the M118C mutants but shows more dramatic impact for the T121C and S141C mutants. These results are in excellent agreement with the experimental observations and offer encouragement that MD can be a useful component of experimental design with considerable predictive power.
Human anti‐DNA autoatibodies and induced antibodies against ROS‐modified‐DNA show similar antigenic binding characteristics
Authors: Alam Khurshid , Ali Rashid
Published: July 2007

Alterations in DNA structure by hydroxyl radical modification was characterized by UV spectroscopy, Tm, nuclease S 1 digestibility and base modification. In view of indicted role of oxygen free radicals in human diseases, an attempt has been made to precisely compare the antigen binding properties of induced antibodies against hydroxyl radical modified DNA with those of naturally occurring anti‐DNA autoantibodies. Antibodies induced against ROS‐DNA showed diverse antigen binding characteristics which were comparable with those derived from SLE patients. The immune IgG recognized native DNA, heat denatured DNA, and synthetic polynucleotides in B‐/B‐like conformations. IgG isolated from SLE sera showed preference for ROS‐DNA in competition‐inhibition assay. The antigenic diversity of induced antibodies and preference of circulating anti‐DNA autoantibodies for ROS‐DNA over that of native DNA demonstrates the possible role of modified DNA antigens in the pathogenesis of SLE.
Cloning and expression of human cDNA encoding human homologue of pituitary tumor transforming gene
Authors: Lee In Ae , Seonga Changkeun , Choe In Seong
Published: July 2007

Recently, a potent transforming gene which was exclusively expressed in rat pituitary tumor but not in normal pituitary had been isolated and named as pituitary tumor transforming gene (PTTG). A cDNA clone encoding human homologue of rat PTTG was isolated from human fetal liver cDNA library. It contained an open reading frame of 603 base pairs predicting a protein composed of 201 amino acids with a calculated molecular weight of 26 kDa. The deduced protein showed about 85% homology (78% identity, 7% favored substitution) with the rat PTTG. Northern blot analysis showed that the cDNA hybridized to 1.0 kb mRNA species which was expressed in fetal liver and several cancer cell lines. These results suggest that the presence of the human homologue of rat PTTG gene may not be restricted to pituitary tumor.
Expression of the divergent transcription unit containing the yeast PET122 and OXA1 genes
Authors: Marathe Sudhir V. , McEwen Joan E.
Published: July 2007

The nuclear PET122 gene of S. cerevisiae encodes a mitochondrial‐localized protein that activates initiation of translation of the mitochondrial mRNA from the COX3 gene, which encodes subunit III of cytochrome c oxidase. The PET122 locus contains two divergent transcription units: one is involved in expression of PET122 mRNA and the mRNA for an adjacent gene OXA1, which is also required for cytochrome c oxidase biogenesis, and the other is involved in expression of an antisense RNA that is complementary to about two thirds of the PET122 mRNA and an adjacent gene YER152C of unknown function. Steady state levels of OXA1, PET122 sense and PET122 antisense RNAs were measured after growth of yeast cells under catabolite repressing or derepressing conditions, or after deletion of portions of the 5′ flanking DNA of the genes. The results reported here indicate that the PET122 and OXA1 genes are unconventional in terms of the control of their transcription. Neither possesses a canonical TATA element and they exhibit no apparent need for native upstream DNA. These results raise the interesting possibility that PET122 and OXA1 transcription is controlled by downstream DNA, perhaps located within the coding regions of the respective genes.
Overexpression of human testis antigens in Escherichia coli host cells is influenced by site of expression and the induction temperature
Authors: Mburu D. N. , Roberts T. K. , Boettcher B.
Published: July 2007

A panel of twenty human testis cDNA clones were expressed in an Escherichia coli expression system and six clones were found to express identifiable fusion polypeptides. Expression was found to be influenced not only by the site of localization of the polypeptide in the host cells, but also by the temperature used for induction. This emphasized the need for cytoplasmic and periplasmic expression of new antigens of unknown properties, as well as the use of temperatures of 30°C or lower. A majority of the expressed polypeptides were mainly in an insoluble form. By reducing the induction temperature to 30°C production of the soluble fraction was further improved.
Free Radicals in Exhaustive Physical Exercise: Mechanism of Production, and Protection by Antioxidants
Authors: VinÑa Jose , Gomez‐Cabrera Mari‐Carmen , Lloret Ana , Marquez Rafael , Miñana Juan B. , Pallardó Federico V. , Sastre Juan
Published: July 2007

Moderate exercise is a healthy practice. However, exhaustive exercise generates free radicals. This can be evidenced by increases in lipid peroxidation, glutathione oxidation, and oxidative protein damage. It is well known that activity of cytosolic enzymes in blood plasma is increased after exhaustive exercise. This may be taken as a sign of damage to muscle cells. The degree of oxidative stress and of muscle damage does not depend on the absolute intensity of exercise but on the degree of exhaustion of the person who performs exercise. Training partially prevents free radical‐formation in exhaustive exercise. Treatment with antioxidants such as vitamins C or E protects in part against free radical‐mediated damage in exercise. Xanthine oxidase is involved in free‐radical formation in exercise in humans and inhibition of this enzyme with allopurinol decreases oxidative stress and muscle damage associated with exhaustive exercise. Knowledge of the mechanism of free‐radical formation in exercise is important because it will be useful to prevent oxidative stress and damage associated with exhaustive physical activity.
Assessment of adhesively bonded joints subjected to surface damage by paint removal
Authors: Prabhune Shantanu C. , Talreja Ramesh
Published: July 2007

Purpose

To provide a basis for making assessment of the safety of adhesively bonded joints after they have been de‐painted by a dry abrasive method or a wet chemical method.

Design/methodology/approach

Stress analysis by a finite element method has been conducted for metal/composite and composite/composite joints in a single lap configuration. The effects of degradation of composite and adhesive, separately or combined, on the stresses in the adhesive layer bonding the two components are studied. Effects of wet and dry conditions of de‐painting are included in the study. It is assumed that in the composite these conditions affect only the laminae close to the surface from which the paint coating is removed.

Findings

The locations and values of the maximum peel and shear stresses in the adhesive are determined for both joints under different assumed conditions of degradation caused by de‐painting.

Research limitations/implications

Experimental data indicating the extent of surface damage caused by de‐painting is not available.

Originality/value

Extensive literature study did not show any investigation of composite surface damage and adhesive property degradation on integrity of adhesively bonded joints. Results reported here will be of use in assessing effects of de‐painting on the structural performance of adhesively bonded joints.