bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular cloning and analysis of the argC gene from Corynebacterium glutamicum
Authors: Chun Jae‐Yeon , Lee Eun‐Jung , Lee Heung‐Shick , Cheon Choong‐Ill , Min Kyung‐Hee , Lee Myeong‐Sok
Published: July 2007

The argC gene encoding N‐acetylglutamate 5‐semialdehyde dehydrogenase has been cloned from Corynebacterium glutamicum by transforming Escherichia coli arginine auxotroph with the genomic DNA library. Based on the restriction map of the cloned DNA, we have subcloned and sequenced the minimal DNA fragment complementing the E. coli argC mutant. The coding region of the cloned gene is 1041 nucleotides long with a predicted molecular mass of about 38 kDa polypeptide. Enzyme activity and size of the expressed protein in the E. coli auxotroph carrying the recombinant argC gene revealed that the cloned gene indeed codes for N‐acetylglutamate 5‐semialdehyde dehydrogenase. Computer analysis of the amino acid sequences of the predicted protein revealed a strong similarity to the corresponding protein of other bacteria.
Increased solubility of glutathione S‐transferase‐p16 (GST‐p16) fusion protein by co‐expression of chaperones groes and groel in Escherichia coli
Authors: Luo Zhong‐Hui , Hua Zi‐Chun
Published: July 2007

Human cdk (cyclin dependent kinase) inhibitor p16 was fused with glutathione S‐transferase (GST) and the GST‐p16 fusion protein is under the control of T7 promoter. When expressed in E. coli BL21(DE3), most products existed in the form of insoluble inclusion bodies. When co‐expressed with molecular chaperones E. coli GroESL, most GST‐p16 products accumulated in the soluble form with a 5‐6 fold increase in solubility. When co‐produced with human protein disulfide isomerase (PDI), there was no improvement in the solubility of GST‐p16 fusion protein.
Redox regulation of signal transduction in vascular smooth muscle cells: Thiol oxidizing agents induced phospholipase D
Authors: Taher Mohiuddin M. , Mahgoub Mahmoud A. , Abd‐Elfattah Anwar S.
Published: July 2007

Decrease in intracellular thiols leads to oxidative stress and thus may cause alterations in the activity of redox‐sensitive enzymes required for signal transduction. Here, we report that, N‐ethylmaleimide and phenylarsine oxide, which are known to oxidize free thiols as well as protein thiols, induced phosphatidyl ethanol generation in the micromolar range suggesting activation of phospholipase D in vascular smooth muscle cells. These agents also induced significant phosphatidic acid and diacylglycerol generation without causing protein kinase C activation. Phenylarsine oxide and N‐ethyl maleimide induced phosphotipase D activation is protein kinase C independent as it was not inhibited by compound‐3 and bisindolylmaleimide, potent protein kinase C inhibitors. Tyrosine kinase inhibitor herbimycin A by itself activated PLD, but inhibited the phospholipase D activation by phenytarsine oxide and N‐ethylmaleimide. These results suggest that oxidation of the cellular thiols activates phospholipase D independent of protein kinase C.
Augmentation in the expression of a ribosomal protein associated with transformation
Authors: Go Hiroki , Taniguchi ShuN′ichiro
Published: July 2007

Using differential hybridization technique, cDNA that was a partial sequence of rat ribosomal protein L41 was isolated from fos‐ and src‐transfected rat fibroblast 3Y1. The cDNA was named #31. Subsequently, the human counterpart(named hm3168) was cloned from a human melanoma cell line(M14) and the amino acid sequence deduced from the cDNA proved to be identical to that of HG‐12. The gene expression of hm3168 was inducible by serum‐stimulation. It reveals the possible up‐regulation of the transcription via fos‐mediated signal transduction. Northern‐blot and Western‐blot analyses showed a large expression of the #31 gene in the rat transformed cell lines.
Arachidonic acid and protein synthesis inhibitor act synergistically to suppress insulin‐stimulated glucose transport in 3T3‐L1 adipocytes
Authors: Liu David , Chen Chih‐Chiun , Chai Shin‐Pei , Ho Low‐Tone , Fong Jim C.
Published: July 2007

The effect of arachidonic acid (AA) on insulin‐stimulated glucose transport by 3T3‐L1 adipocytes was examined in the presence of cycloheximide. We found that AA acted synergistically with cycloheximide to suppress insulin‐stimulated glucose transport, although it alone was without effect. Similar phenomena were observed while protein synthesis inhibitors other than cycloheximide were employed. Immunoblot analysis indicated that the increase in plasma membranes of the insulin‐regulated glucose transporter (GLUT4) in response to insulin was decreased in cells pretreated with cycloheximide for a prolonged time, while total amount of GLUT4 was not altered. Simultaneous presence of AA with cycloheximide had no further effect on the amount of GLUT4 in either total or plasma membranes. Thus the present study suggests that AA in the presence of a protein synthesis inhibitor seems to decrease the intrinsic activity of GLUT4.
A multiplex RT‐PCR assay for analysis of relative transcript levels of different members of multigene families: Application to Arabidopsis calmodulin gene family
Authors: Verma Praveen K. , Upadhyaya Kailash C.
Published: July 2007

The high degree of conservation of nucleotide sequences among different members of a multigene family poses problems in analysis of expression patterns governed by each member of the gene family. In this report we describe a simple, semi‐quantitative and single tube multiplex RT‐PCR assay for simultaneous and relative expression analysis with an application to all the six members of Arabidopsis calmodulin multigene family. In the multiplex primer set, individual gene specific primers were derived from 3′‐untranslated region of the genes and a single common primer from the conserved exonic region. Transcriptional activation of all the members of the calmodulin gene family in response to touch was monitored. The results demonstrate that two of the genes are not regulated by touch; however, the other four that are induced by touch show a differential response including their kinetics of induction.
Inverse effects of 20K and 22K human growth hormones on the growth of T‐47D human breast cancer cells in culture and in nude mice
Authors: Fujikawa Takahiko , Kaneko Hiroshi , Hibasami Hiroshige , Sakaguchi Kesami , Alam Khorshed S. M. , Tanaka Minoru , Nakashima Kunio
Published: July 2007

The major form of human growth hormone (22K hGH) stimulates the growth of T‐47D human breast cancer cells in culture and in nude mice by binding to their receptors for growth hormone and prolactin. Another isoform of hGH having a smaller molecular mass (20K hGH) is known to show different binding affinities to these receptors. In this study, we have analyzed the effects of 20K hGH on the growth of T‐47D cells in vitro and in vivo. 20K hGH (50 ng/ml) inhibited the proliferation and DNA synthesis of T‐47D cells cultured in the presence and absence of 17β‐estradiol (100 ng/ml), while 22K hGH (50 ng/ml) promoted the cellular growth. In estradiol‐treated nude mice, 22K hGH (100 μg) remarkably promoted the growth of T‐47D tumor, but 20K hGH again suppressed the tumor growth significantly. The results suggest the presence of different signal pathways for these two hGH isoforms and imply a possible clinical application for 20K hGH.
Growth retardation and discordant twin pregnancy. An immunomorphological and biochemical characterisation of the human umbilical cord
Authors: Salvolini Eleonora , Lucarini Guendalina , Cester Nelvio , Arduini Domenico , Mazzanti Laura
Published: July 2007

Growth retardation and low birth weight represent an important factor associated with the high risk of mortality and morbidity, particularly in twin pregnancy, since twins are frequently characterised by fetal growth retardation and sometimes by a discordant growth between the twins. The present work sets out to elucidate the role of growth discordance between twins in the behaviour of human umbilical vein endothelial cells; biochemical, ultrastructural and immunohistochemical data obtained from a discordant twin pregnancy are discussed. Endothelial cells were obtained from umbilical cord of 5 singleton pregnancies and from 5 dichorionic twin pregnancies, among which was one discordant twin pregnancy. Membrane fluidity was assayed using a fluorescent probe and each sample was immunohistochemically processed employing specific monoclonal antibodies. An increased fluidity was observed in endothelial cells from the smaller twin as compared with the larger one. As concerns electron microscopy, the features of endothelial cells from the smaller twin were similar to those of twins with similar growth, while endothelial cells from the larger one were more similar to those from singleton pregnancies. Our findings confirm the presence of the feto‐fetal transfusion as a pathogenetic mechanism involved in twin growth discordancy.
Changes of glycosylation of serum proteins in psoriatic arthritis, studied by enzyme‐linked lectin assay (ELLA), using concanavalin A
Authors: Saso Luciano , Valentini Giovanni , Giardino Angela Maria , Spadaro Antonio , Riccieri Valeria , Zoppini Antonio , Silvestrini Bruno
Published: July 2007

Changes of glycosylation of serum proteins of patients with psoriatic arthritis were detected by lectin blotting and a new enzyme‐linked lectin assay (ELLA) using concanavalin A (Con A). A good linear correlation was found between the total Con A‐reactivity of serum and the serum levels of C‐reactive protein and interleukin‐6, which is known to regulate the glycosylation pattern of proteins upon inflammation. A good linear correlation was also observed between the immunoreactivity of α1‐antitrypsin, measured by ELISA, using a monoclonal antibody sensitive to glycosylation changes, and the erythrocyte sedimentation rate and the serum concentrations of soluble interleukin‐2 receptor, an index of lymphocyte activation which correlated with some inflammatory parameters of disease activity. These protein changes, which are described here for the first time, deserve to be studied in further detail in view of their possible clinical applications.
Protein Binding in vivo to OP2 promoter of the Pseudomonas putida TOL plasmid
Authors: Miura Koshiro , Inouye Sachiye , Nakazawa Atsushi
Published: July 2007

The transcription of OP2 encoding enzymes for m‐toluate catabolism on the Pseudomonasputida TOL plasmid is activated by basal‐level XylS protein in the presence of m‐toluate or by overproduced XylS protein in the absence of m‐toluate. In this study, in vivo dimethyl sulfate (DMS) footprinting was performed to understand the mechanism of transcriptional regulation of OP2 promoter by XylS. In the presence of overproduced XylS without m‐toluate, several protected nucleotides were observed, indicating the binding of RNA polymerase to DNA. However, the protection was canceled upon addition of m‐toluate. These results suggest that RNA polymerase is retained by XylS on the OP2 promoter in the absence of inducer, and is released by m‐toluate binding to XylS, concomitant with transcription.
Effect of chronic alcohol ingestion on buccal mucosal expression of bFGF and Cdk2 during ulcer healing
Authors: Slomiany B. L. , Piotrowski J. , Slomiany A.
Published: July 2007

In this study, we investigated the effect of chronic alcohol ingestion on the interplay between the receptor‐bound basic fibroblast growth factor (bFGF‐R) and the expression of cyclin‐dependent kinase (Cdk2) in buccal mucosa during ulcer healing. Chronic ulceration was induced by a topical application of acetic acid to the buccal mucosa of rats maintained for 5 weeks on alcohol‐containing or control liquid diet. In both groups, the ulcer healing was accompanied by an increase in buccal mucosal expression of bFGF and Cdk2. In the control group, the ulcer healed within 10 days and maximum induction in bFGF (2.6‐fold) and Cdk2 (2.4‐fold) occurred by the 2nd day of healing. In contrast, the alcohol diet group showed a marked delay in ulcer healing (14 days), associated with the shift in maximum of bFGF and Cdk2 expression to the 4‐6th day, and the values were reduced by 35 to 38%. The findings show that chronic alcohol ingestion exerts detrimental effect on the signaling events initiated by bFGF‐receptor activation and propagated by Cdk2 that propels the cell cycle progression essential for rapid mucosal repair.
Hexokinase, glucose‐6‐phosphate dehydrogenase and antioxidant enzymes in diabetic reticulocytes: effects of insulin and vanadate
Authors: Gupta Bihari L. , Baquer Najma Z.
Published: July 2007

Experimentally induced diabetic rats were treated separately with insulin and vanadate. The activities of hexokinase (HK) and glucose‐6‐phosphate dehydrogenase (G‐6PDH) were increased in reticulocyte hemolysate isolated from the diabetic rats and were restored to normal levels by insulin. The restoration was not detected in vanadate treated diabetic animals. The enzymes of glutathione metabolism namely glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione‐s‐transferase (GST) exhibited increases in their activities with diabetes and were restored to almost control values by insulin treatment. Vanadate given to diabetic animals further increased GPx, and GST. The level of superoxide dismutase(SOD) decreased in the reticulocytes of diabetic rats and catalase (CAT) was unchanged. Both CAT and SOD had normal values when the diabetic rats were treated with insulin and vanadate. It is proposed that vanadate may cause an increase in the activity of GR which may stimulate glucose transporters and glucose metabolism.
Zinc‐induced damage to carp (Cyprinus carpio L.) erythrocytes in vitro
Authors: Akahori Anna , Gabryelak Teresa , Józwiak Zofia , Gondko Roman
Published: July 2007

Fish erythrocytes were used to elucidate the effect of zinc ions on the cell antioxidant defence system. It was detected that an increase of the Zn2+ concentration (0.01‐1 mM) leads to a marked decrease (p<0.05) in the catalase and the glutathione peroxidase activities. We observed a loss of 14‐39 % activity of glutathione peroxidase, and 16‐20% diminution for catalase. No significant changes were found in case of the superoxide dismutase. Incubation of red blood cells with zinc brought about a decrease of the erythrocyte thiol group content. Treatment of carp erythrocytes with zinc ions also resulted in enhanced hemolysis and in the induction of significant (p<0.001) changes in the intracellular glucose level. The increase of glucose concentration in the erythrocytes was correlated with increased concentration of metal in the incubation medium. It was proposed that Zn could affect transport systems across the red blood cells and therefore increased the permeability of the membranes to small molecules (e.g. hexose), and led to hemolysis. Zinc ions could act as a potential cell toxicant, leading to disturbances in functions of the antioxidant defence system and to alterations in the erythrocyte membrane properties.
Expression of two dead box gene (DDX1 amd DDX6) is independent of that of MYCN in human neuroblastoma cell lines
Authors: Akiyama Kiyotaka , Akao Yukihiro , Yokoyama Masahiro , Nakagawa Yoshihito , Noguchi Tohru , Yagi Kunio , Nishi Yoshisuke
Published: July 2007

To examine whether two DEAD box genes, DDX1 and DDX6, would have some roles in the progression of tumors, we investigated the correlation of the expression of these genes with that of MYCN in neuroblastomas either with or without MYCN amplification. The mRNA of MYCN was observed only in the cell lines with amplification of MYCN. The mRNAs of DDX1 and DDX6 were found in all the cell lines examined, but the correlation between the mRNA levels of DDX1 or DDX6 and MYCN was poor. These findings suggest that the expression of neither DEAD box gene is correlated with the gene expression of MYCN.
Citrate carrier and lipogenic enzyme activities in lead intrate‐induced proliferative and apoptotic phase in rat liver
Authors: Dini Luciana , Giudetti Anna Maria , Ruzittu Mariateresa , Gnoni Gabriele V. , Zara Vincenzo
Published: July 2007

After in vivo administration of lead nitrate, functional changes of the mitochondrial tricarboxylate carrier and of the cytosolic lipogenic enzymes acetyl‐CoA carboxylase and fatty acid synthetase have been detected in rat liver. The rate of citrate transport was greatly reduced in rats during both the proliferative phase (3 days after the lead nitrate administration) and the involutive phase (5 days after the metal injection), which follows hepatic hyperplasia and corresponds to the peak of hepatocyte apoptosis. In both phases, a decrease of the lipogenic enzyme activities has been detected. In treated animals, an alteration of mitochondrial lipid composition has also been found. The modified lipid microenvironment could be responsible for the decreased carrier activity which, in turn, may account for the reduced activities of the lipogenic enzymes.
GroEL protects the sarcoplasmic reticulum Ca ‐dependent ATPase from inactivation in vitro
Authors: Javed Masood Ul Hassan , Michelangeli Francisco , Lund Peter A.
Published: July 2007

The molecular chaperone, GroEL, facilitates correct protein folding and inhibits protein aggregation. The function of GroEL is often, though not invariably, dependent on the cochaperone, GroES, and ATP. In this study it is shown that GroEL alone substantially reduces the inactivation of purified Ca++‐ATPase from rabbit skeletal muscle sarcoplasmic reticulum. In the absence of GroEL, the enzyme became completely inactive in about 45‐60 hours when kept at 25°C, while in the presence of an equimolar amount of GroEL, the enzyme remained approximately 80% active even after 75 hours. Equimolar amounts of BSA or lysozyme were unable to protect the enzyme from inactivation under identical conditions. Analysis by SDS‐PAGE showed GroEL was acting by blocking the aggregation of ATPase at 25°C. GroEL was not as effective in protection at ‐20°C or 4°C. These results are discussed in the context of current models of the GroEL mechanism.
Absence of R1066X mutation in six Japanese patients with Dubin‐Johnson syndrome
Authors: Kagawa Tatehiro , Sato Masahiro , Hosoi Katsumi , Uchiyama Junzo , Nishizaki Yasuhiro , Watanabe Norihito , Inagaki Yasutaka , Kimura Minoru , Matsuzaki Shohei
Published: July 2007

The Dubin‐Johnson syndrome (DJS)is a rare autosomal recessive liver disease characterized by chronic conjugated hyperbilirubinemia. The phenotype of this syndrome is thought to be caused by the impaired expression of the canalicular multispecific organic anion transporter (cMOAT), which transports non‐bile salt organic anions into the bile. Recently, a mutation from arginine (Arg) to stop‐codon at codon 1066 in the cMOAT gone has been reported in one Caucasian patient with DJS. In this study, we investigated whether this mutation is found in Japanesei patients with DJS. Genomic DNAs were extracted from the leukocytes of six Japanese patients and the fragments spanning codon 1066 were amplified by polymerase‐chain reaction. The digest of the amplified fragments with a restriction enzyme, Taql, demonstrated that all of six patients did not exhibit an R1066X mutation. No mutation at Arg1066 was also confirmed by direct sequencing of the amplified products. These findings suggested that this R1066X mutation was not a major mutation in Japanese patients with DJS. Further investigation will be required in an attempt to search other mutations in cMOAT gene in Japanese patients with DJS.
Protein kinase C isoforms in the epidermal tissues of normal and postburn human skin
Authors: Wang Yen‐Chu , Hsieh Yih‐Shou , Tang Yu‐Wen , Liu Jer‐Yuh
Published: July 2007

Because the expression of the isoforms of protein kinase C (PKC) in human basal keratinocytes is not understood, the expression of PKC isoforms were screened in specimens of epidermal tissue from postburn skin and the normal locations for skin grafts in patients with second or higher degrees of flame injury. The expression of individual isoform was determined by Western blot technique. Only PKC α and ζ were detected in the epidermal tissues of normal and postburn skin and translocation occurred in PKC α. Patients without antibiotic treatment after flame injury had higher expressions of PKC α and ζ. These findings indicate that the mechanisms of cellular differentiation and growth in postburn epidermal tissue may be related to the expression and translocation of PKC α induced by intra‐ and extracellular stimulation. These changes in PKC α further activate the DAG/PKC signal transduction pathways.
Lipoprotein alterations, abdominal fat distribution and breast cancer
Authors: Schreier Laura E. , Berg Gabriela A. , Basilio Francisco M. , Lopez Graciela I. , Etkin Alberto E. , Wikinski Regina L.
Published: July 2007

Plasma lipid profile and abdominal obesity have been associated with breast cancer risk, however published results have been inconsistent. To clarify these associations we studied lipid and lipoprotein alterations, obesity degree and body fat distribution, in 30 newly diagnosed breast cancer patients without treatment and 30 controls matched by age and menopausal status. Both pre and postmenopausal breast cancer patients presented higher body mass index, waist/hip ratio and insulin levels than their matched controls. An increase in triglycerides and a decrease in HDL‐cholesterol, especially in the HDL2 subfraction, were observed in patients with breast cancer. Besides, HDL particle from these patients showed increased apo A1/HDL‐cholesterol ratio. These alterations were correlated with waist/hip ratio.

The association between lipoprotein alterations and abdominal obesity independent of menopausal status, in untreated newly diagnosed breast cancer patients is reported for the first time in this study.
Influence of atropine on carbachol dual effect on Ca2 mobilization in SH‐SY5Y neuroblastoma cells
Authors: Oras Aldo , Järv Jaak , Åkerman Karl E. O.
Published: July 2007

The muscarinic receptor stimulated mobilisation of calcium ions in SH‐SY5Y neuroblastoma cells was measured as a function on carbachol and atropine concentrations. The combined application of this pair of muscarinic agonist and antagonist yielded a set of bell‐shaped dose‐response curves. In the presence of atropine the cell responses were smaller and the up‐going phase of these relationships was shifted towards higher agonist concentration, while the down‐going phase of these curves was not influenced by the antagonist. These results pointed to a similar mechanism of the receptor inhibition at high carbachol (agonist) concentrations and by atropine (antagonist).
Inhibition of eukaryotic DNA polymerase α by persimmon (Diospyros kaki) extract and related polyphenols
Authors: Umekawa Hayato , Takada Yoshie , Furuichi Yukio , Takahashi Takao , Achiwa Yumiko , Komiya Takashi , Yoshida Shonen
Published: July 2007

The effects of persimmon extract (Diospyros kaki) and related polyphenols on eukaryotic DNA polymerase α were examined. It was found that persimmon extract, epigallocatechin gallate, and epicatechin gallate strongly inhibited the activity of DNA polymerase α purified from calf thymus. Among these polyphenols, persimmon extract had the most potent effect on DNA polymerase α activity and the concentration of persimmon extract producing 50% inhibition of the activity was 0.191 μM. Persimmon extract showed a weaker effect on DNA polymerase β and slightly inhibited primase and DNA polymerase I. The inhibition of DNA polymerase α by persimmon extract was competitive with the template‐primer and noncompetitive with dTTP substrate. The Ki value of DNA polymerase α for persimmon extract was estimated to be 70 nM. Moreover, persimmon extract inhibited [3H]thymidine incorporation of human peripheral lymphocyte cells stimulated by PHA.
The Shifting Identities and Loyalties in Kyrgyzstan: The Evidence from the Field
Authors: Elebayeva Ainura , Omuraliev Nurbek , Abazov Rafis
Published: July 2007

The main objective of the ethnic policy of the government of Kyrgyzstan in the post-Soviet era was a consolidation of all people and ethnic groups on the territory of the Republic into the Kyrgyzstani nation. Such a goal is important for any nation that has just gained independence, but for the Kyrgyz Republic it was an especially important task for several reasons. First, the multiethnic composition of the country: in 1991 the Kyrgyzs, or the titular nation of the Republic, constituted roughly 52% of the population, there were around 22% Russians, and the Uzbeks represented 13% of the population. Second, interethnic relations in the Republic were especially tense at the beginning of the 1990s because of the interethnic conflicts in the southern regions of the Republic in 1989 and 1990.1 Third, the Kyrgyzs themselves lacked national cohesiveness and they often defined themselves as members of different tribes or tribal groups with distinct dialects, dress, and political affiliations.
The Broad Spectrum of Responses to Oxidants in Proliferating Cells: A New Paradigm for Oxidative Stress
Authors: Davies Kelvin J. A.
Published: July 2007

Proliferating mammalian cells exhibit a broad spectrum of responses to oxidative stress, depending on the stress level encountered. Very low levels of hydrogen peroxide, e.g., 3 to 15 mu M, or 0.1 to 0.5 mu mol/107 cells, cause a significant mitogenic response, 25% to 45% growth stimulation. Greater concentrations of H2O2, 120 to 150 mu M, or 2 to 5 mu mol/107 cells, cause a temporary growth arrest that appears to protect cells from excess energy use and DNA damage. After 4 6 h of temporary growth arrest, many cells will exhibit up to a 40‐fold transient adaptive response in which genes for oxidant protection and damage repair are preferentially expressed. After 18 h of H2O2 adaptation (including the 4‐6h of temporary growth arrest) cells exhibit maximal protection against oxidative stress. The H2O2 originally added is metabolized within 30‐40min, and if no more is added the cells will gradually de‐adapt, so that by 36h after the initial H2O2 stimulus they have returned to their original level of H2O2 sensitivity. At H2O2 concentrations of 250 to 400 mu M, or 9 to 14 mu mol/107 cells, mammalian fibroblasts are not able to adapt but instead enter a permanently growth‐arrested state in which they appear to perform most normal cell functions but never divide again. This state of permanent growth arrest has often been confused with cell death in toxicity studies relying solely on cell proliferation assays as measures of viability. If the oxidative stress level is further increased to 0.5 to 1.0 mM H2O2, or 15 to 30 mu mol/107 cells, apoptosis results. This oxidative stressinduced apoptosis involves nuclear condensation, loss of mitochon/drial transmembrane potential, degradation/down‐regulation of mitochondrial mRNAs and rRNAs, and degradation laddering of both nuclear and mitochondrial DNA. At very high H2O2 concentrations of 5.0 to 10.0 mM, or 150 to 300 mu mol/107 cells and above, cell membranes disintegrate, proteins and nucleic acids denature, and necrosis swiftly follows. Cultured cells grown in 20% oxygen are essentially preadapted or preselected to survive under conditions of oxidative stress. If cells are instead grown in 3% oxygen, much closer to physiological cellular levels, they are more sensitive to an oxidative challenge but exhibit far less accumulated oxidant damage. This broad spectrum of cellular responses to oxidant stress, depending on the amount of oxidant applied and the concentration of oxygen in the cell culture system, provides for a new paradigm of cellular oxidative stress responses.
Effects of Vanadate on Expression of Liver Arginase in Experimental Diabetic Rats
Authors: Upadhyaya Salimuddin Kailash C. , Baquer Najma Z.
Published: July 2007

This work was carried out to study the effects of vanadate on the expression of liver‐type arginase in experimentally induced diabetes in the rat. The results showed that the activity and mRNA levels of arginase were increased significantly in the diabetic condition. Vanadate treatment reversed the increased activity and restored mRNA levels of arginase almost to the control values. The reversal effects of vanadate were found to be similar to those of insulin, and this further confirms the insulin‐like effects of vanadate. ELISA and slot‐blot assay observations were consistent with the biochemical measurements of enzyme activity. The increase in arginase activity and mRNA levels in diabetes and the decrease in insulin‐ and vanadate‐treated animals may be due to the transcriptional regulation of arginase.
Association Between Angiotensin‐Converting Enzyme Gene Polymorphism and Coronary Artery Disease
Authors: Isbir Turgay , Yilmaz Hulya , Agachan Bedia , Aydin Makbule , Isbir C. Selim
Published: July 2007

An insertion/deletion (I/D) polymorphism in the gene for angiotensin‐converting enzyme (ACE) is associated with myocardial infarction and other cardiac pathology. There is evidence for a role of the renin‐angiotensin system in cell growth and in the repair of damaged arterial walls, so the ACE gene is postulated to be a candidate gene affecting the important clinical problem of coronary artery disease (CAD). In view of the clinical importance of the ACE as a major marker of cardiovascular diseases, we investigated the I/D polymorphism of the ACE gene in Turkish CAD patients in comparison with control subjects to evaluate a possible association between CAD and the gene encoding ACE. Polymerase chain reaction, restriction fragment length polymorphism, and agarose gel electrophoresis techniques were used to determine the ACE genotype in 58 subjects. The frequencies of ACE D and ACE I allele among the patients with CAD were 62.26% and 37.73% and in the control subjects were 49.3% and 50.76%, respectively. The greater frequency of deletion allele (D) was in the CAD group than in the control subjects was significant (P < 0.01).
Isolation and Characterization of a New Trypsin Inhibitor from Crotalaria paulina Seeds
Authors: Pando Luiza A. , Ciero Luciana Di , Novello Jose C. , Oliveira Benedito , Weder Jurgen K. P. , Marangoni Sergio
Published: July 2007

A new trypsin inhibitor (CPTI) has been isolated from Crotalaria paulina seeds. Purification of the inhibitor was carried out by gel filtration, ion‐exchange chromatography, and subsequent reversed‐phase HPLC. The presence of a single polypeptide chain, with a molecular mass of 20 kDa and isoelectric point 4.0, was detected. The trypsin inhibitor had a K i value of 4.5 X 10 ‐8 M and was capable of acting on human, bovine, and porcine trypsin and weakly on bovine chymotrypsin. Amino acid analysis showed that CPTI has a high content of aspartate, glutamate, leucine, serine, and glycine, having 177 amino acid residues in its composition. These data suggest that the protein belongs to the Kunitz‐type trypsin inhibitors.
Mechanism of Oxidative Damage to Fish Red Blood Cells by Ozone
Authors: Fukunaga Kenji , Nakazono Naoki , Suzuki Tetsuya , Takama Kozo
Published: July 2007

The present study was conducted to elucidate the adverse effects of ozone exposure on rainbow trout (Oncorhynchus mykiss) red blood cells (RBCs). We evaluated whether hemoglobin (Hb) or Hb‐derived free iron could participate in the RBC damage using an in vitro ozone exposure system. Ozone exposure induced hemolysis, formation of methemoglobin, and RBC membrane lipid peroxidation. This RBC damage was not suppressed by the addition of a specific iron chelator (deferoxamine mesilate) to the medium but was suppressed by carbon monoxide (CO) treatment before ozone exposure. Generation of hydrogen peroxide (H2O2) in RBC was observed upon ozone exposure but was significantly suppressed by CO treatment before ozone exposure. Thus the Hb status (i.e., Hb redox condition) and H2O2 generation in RBC should play important roles in mediating RBC damage by ozone exposure. In other words, neither ozone nor its derivative directly attacked from the outside of the cell, but ozone that penetrated through the membrane derived the reactive oxygen species from Hb inside of the cell.
Signature Sequences for the Galectin‐4 Subfamily
Authors: Jiang Weiping , Puch Sabine , Guo Xiaoxuan , Bhavanandan Veer P.
Published: July 2007

Summary Galectins are a distinct family of animal lectins that have a cation‐independent affinity for beta‐galactoside sugars and share characteristic amino acid sequences. The cDNA encoding rabbit bladder galectin‐4 has been cloned and sequenced (GenBank accession no. AF091738). The deduced 328 amino acid sequence predicts a multidomain structure consisting of an N‐terminal peptide (19 residues) and two carbohydrate recognition domains (130 residues each) connected by a linker region (49 residues). Comparison of rabbit galectin‐4 with related proteins reveals that two peptide motifs, M‐A‐F/Y‐V‐P‐A‐P‐G‐Y‐Q‐P‐T‐Y‐N‐P‐T‐L‐P‐Y in the N terminus and A‐F‐H‐F‐N‐P‐R‐F‐D‐G‐W‐D‐K‐V‐V‐F in the first carbohydrate recognition domain are highly conserved in human, pig, rat, and mouse galectin‐4 as well as in mouse galectin‐6. The two peptide motifs are proposed here as the signature sequences to identify new members of the galectin‐4 subfamily.
General and acculturation‐related daily hassles and psychological adjustment in first‐ and second‐generation South Asian immigrants to Canada
Authors: Abouguendia Mona , Noels Kimberly A.
Published: July 2007

According to Lay and Nguyen (1998), in addition to the general daily hassles encountered by most people, immigrants often face chronic difficulties specific to the acculturation experience, including conflicts with family members, members of the ethnic ingroup, and members of ethnic outgroups. Moreover, it has been suggested that the children of immigrants born in Canada (i.e., second‐generation immigrants) may experience different acculturative stressors from their parents (i.e., first‐generation immigrants). This study examined general and acculturation‐related daily hassles in 74 first‐ and second‐generation South Asians in Canada. Participants completed a questionnaire that assessed their experience of different types of daily hassles (general, family, ingroup, and outgroup), acculturation attitudes, and level of psychological adjustment. Second‐generation individuals reported significantly more ingroup hassles and marginally lower self‐esteem than first‐generation immigrants. For first‐generation immigrants, more ingroup hassles predicted greater depression, and for second‐generation individuals, increased ingroup hassles predicted lower self‐esteem and more outgroup hassles predicted greater depression. The results emphasize the importance of considering the acculturation experience of second‐generation individuals as being unique to that of first‐generation immigrants.
Cloning, Structural Characterization, and Phylogenetic Analysis of Flower MADS-Box Genes from Crocus (Crocus sativusL.)
Authors: Tsaftaris Athanasios S. , Polidoros Alexios N. , Pasentsis Konstantinos , Kalivas Apostolos
Published: July 2007

Crocus (Crocus sativusL.) is a crop species cultivated for its flowers and, more specifically, for its red stigmas. The flower of crocus is bisexual and sterile, since crocus is a triploid species. Its perianth consists of six petaloid tepals: three tepals in whorl 1 (outer tepals) and three tepals in whorl 2 (inner tepals). The androecium consists of three distinct stamens and the gynoecium consists of a single compound pistil with three carpels, a single three-branched style, and an inferior ovary. The dry form of the stigmas constitutes the commercial saffron used as a food additive, in the coloring industry, and in medicine. In order to uncover and understand the molecular mechanisms controlling flower development in cultivated crocus and its relative wild progenitor species, and characterize a number of crocus flower mutants, we have cloned and characterized different, full-length, cDNA sequences encoding MADS-box transcription factor proteins involved in flower formation.

Here we review the different methods followed or developed for obtaining these sequences involving conventional 5' 3' RACE, as well as newly developed methods from our group, named Rolling Circle Amplification – RACE (RCA-RACE) and its modification named familyRCA-RACE (famRCA-RACE). Furthermore, the characteristics of the protein structure and their common and specific domains for each type of MADS-box transcription factors in this lower nongrass monocot belonging to the Iridaceae family are described. Finally, a phylogenetic tree of all the MADS-box sequences available in our lab is presented and discussed in relation to other data from studies of species of the Iridaceae group and closely related families from an evolutionary perspective. The structural and phylogenetic analyses are based on both published and unpublished data.
Zebrafish Fins as a Model System for Skeletal Human Studies
Authors: Marí-Beffa Manuel , Santamaría Jesús A. , Murciano Carmen , Santos-Ruiz Leonor , Andrades José A. , Guerado Enrique , Becerra José
Published: July 2007

Recent studies on the morphogenesis of the fins ofDanio rerio(zebrafish) during development and regeneration suggest that a number of inductive signals involved in the process are similar to some of those that affect bone and cartilage differentiation in mammals and humans. Akimenko et al. (2002) has shown that bone morphogenetic protein-2b (BMP2b) is involved in the induction of dermal bone differentiation during fin regeneration. Many other groups have also shown that molecules from the transforming growth factor-beta superfamily (TGFβ), including BMP2, are effective in promoting chondrogenesis and osteogenesisin vivoin higher vertebrates, including humans. In the present study, we review the state of the art of this topic by a comparative analysis of skeletal tissue development, regeneration and renewal processes in tetrapods, and fin regeneration in fishes. A general conclusion of this study states that lepidotrichia is a special skeletal tissue different to cartilage, bone, enamel, or dentine in fishes, according to its extracellular matrix (ECM) composition. However, the empirical analysis of inducing signals of skeletal tissues in fishes and tetrapods suggests that lepidotrichia is different to any responding features with main skeletal tissues. A number of new inductive molecules are arising from fin development and regeneration studies that might establish an empirical basis for further molecular approaches to mammal skeletal tissues differentiation. Despite the tissue dissimilarity, this empirical evidence might finally lead to clinical applications to skeletal disorders in humans.
AnUstilago maydisGene Involved in H2O2 Detoxification Is Required for Virulence
Authors: Molina Lázaro , Kahmann Regine
Published: July 2007

The fungus Ustilago maydis is a biotrophic pathogen of maize (Zea mays). In its genome we have identified an ortholog of YAP1 (for Yeast AP-1-like) from Saccharomyces cerevisae that regulates the oxidative stress response in this organism. yap1 mutants of U. maydis displayed higher sensitivity to H2O2 than wild-type cells, and their virulence was significantly reduced. U. maydis yap1 could partially complement the H2O2 sensitivity of a yap1 deletion mutant of S. cerevisiae, and a Yap1-green fluorescent protein fusion protein showed nuclear localization after H2O2 treatment, suggesting that Yap1 in U. maydis functions as a redox sensor. Mutations in two Cys residues prevented accumulation in the nucleus, and the respective mutant strains showed the same virulence phenotype as Δyap1 mutants. Diamino benzidine staining revealed an accumulation of H2O2 around yap1 mutant hyphae, which was absent in the wild type. Inhibition of the plant NADPH oxidase prevented this accumulation and restored virulence. During the infection, Yap1 showed nuclear localization after penetration up to 2 to 3 d after infection. Through array analysis, a large set of Yap1-regulated genes were identified and these included two peroxidase genes. Deletion mutants of these genes were attenuated in virulence. These results suggest that U. maydis is using its Yap1-controlled H2O2 detoxification system for coping with early plant defense responses.
Chernobyl exposure as stressor during pregnancy and behaviour in adolescent offspring
Authors: Huizink A. C. , Dick D. M. , Sihvola E. , Pulkkinen L. , Rose R. J. , Kaprio J.
Published: July 2007

Objective:  Research in animals has shown that exposure to stressors during pregnancy is associated with offspring behavioural disorders. We aimed to study the effect of in utero exposure to the Chernobyl disaster in 1986, and maternal anxiety presumably associated with that exposure, on behaviour disorder observed at age 14.

Method:  Exposed (n = 232) and non‐exposed Finnish twins (n = 572) were compared. A semi‐structured interview was used to assess lifetime symptoms of depression, generalized anxiety disorder, attention deficit hyperactivity disorder, conduct disorder and oppositional defiant disorder symptoms.

Results:  Adolescents who were exposed from the second trimester in pregnancy onwards, had a 2.32‐fold risk (95% CI: 1.13–4.72) of having lifetime depression symptoms, an increased risk of fulfilling DSM‐III‐R criteria of a major depressive disorder (OR = 2.48, 95% CI: 1.06–5.7), and a 2.01‐fold risk (95% CI: 1.14–3.52) of having attention deficit hyperactivity disorder symptoms.

Conclusion:  Perturbations in fetal brain development during the second trimester may be associated with the increased prevalence of depressive and attention deficit hyperactivity disorder symptoms.
Dietary flaxseed inhibits atherosclerosis in the LDL receptor-deficient mouse in part through antiproliferative and anti-inflammatory actions
Authors: Dupasquier Chantal M. C. , Dibrov Elena , Kneesh Annette L. , Cheung Paul K. M. , Lee Kaitlin G. Y. , Alexander Helen K. , Yeganeh Behzad K. , Moghadasian Mohammed H. , Pierce Grant N.
Published: July 2007

Dietary flaxseed has been shown to have potent antiatherogenic effects in rabbits. The purpose of the present study was to investigate the antiatherogenic capacity of flaxseed in an animal model that more closely represents the human atherosclerotic condition, the LDL receptor-deficient mouse (LDLrKO), and to identify the cellular mechanisms for these effects. LDLrKO mice were administered a regular diet (RG), a 10% flaxseed-supplemented diet (FX), or an atherogenic diet containing 2% cholesterol alone (CH) or supplemented with 10% flaxseed (CF), 5% flaxseed (CF5), 1% flaxseed (CF1), or 5% coconut oil (CS) for 24 wk. LDLrKO mice fed a cholesterol-supplemented diet exhibited a rise in plasma cholesterol without a change in triglycerides and an increase in atherosclerotic plaque formation. The CS mice exhibited elevated levels of plasma cholesterol, triglycerides, and saturated fatty acids and an increase in plaque development. Supplementation of the cholesterol-enriched diet with 10% (wt/wt) ground flaxseed lowered plasma cholesterol and saturated fatty acids, increased plasma ALA, and inhibited plaque formation in the aorta and aortic sinus compared with mice fed a diet supplemented with only dietary cholesterol. The expression of proliferating cell nuclear antigen (PCNA) and the inflammatory markers IL-6, mac-3, and VCAM-1 was increased in aortic tissue from CH and CS mice. This expression was significantly reduced or normalized when flaxseed was included in the diet. Our results demonstrate that dietary flaxseed can inhibit atherosclerosis in the LDLrKO mouse through a reduction of circulating cholesterol levels and, at a cellular level, via antiproliferative and anti-inflammatory actions.
Autofrettage theory and fatigue life of open-ended cylinders
Authors: Rees D W A
Published: July 2007

Two new theories of autofrettage are presented for an open-ended, thick-walled cylinder which can take into account work-hardening in the presence of small plastic strains based upon equivalent uniaxial stress-strain data. They apply to an internally pressurised cylinder where the axial force is not reacted by the cylinder wall, as is the case with the closed-end or plane strain condition, but where a close fitting internal piston or plug is supported separately to contain the pressure. It is shown that solutions to the wall stress distributions depend upon the initial yield condition. Both the Tresca and von Mises flow rules are employed to determine applied and residual stress distributions for given elastic-plastic radii in the wall of the cylinder, assuming purely elastic unloading. Since the Tresca theory does not specifically account for the open-end condition the von Mises theory is taken to be the more realistic, particularly for cylinder diameter ratios ( W) in excess of ≈3, where the largest discrepancies between theories arise. It is reasoned, from previous experimental observations, that the greatest benefit autofrettage has on fatigue strength applies to an optimum pressure for which the equivalent residual stress in the bore has not involved reversed yielding. The onset of reversed yielding may be estimated most realistically with an account of the Bauschinger effect as supplied by the rule of kinematic hardening.

In order to further appraise these theories they are employed to predict the fatigue life of fully autofrettaged W = 2, Ni-Cr-Mo cylinders. For this purpose the stress intensity factor calibration of Parker and Farrow is used and that of Bowie and Freese is modified to account for the presence of the residual stress. Comparisons made with available experimentally-determined fatigue lives confirm that a non-hardening assumption is acceptable with this cylinder geometry.
New approximate formulae in the torsion problem
Authors: Ward J P , Devine N F
Published: July 2007

This Note describes the development of new approximate formula for torsional rigidity of beams with simply connected cross-sections. The formulae are not dependent on a ‘thin-section’ assumption and can be applied to cross-sections with many ‘corners’ and many ‘ends’. The formulae give values for torsional rigidity with accuracies which compare well with those achieved using a sophisticated finite element analysis.
Effect of nut compliance on screw thread load distribution
Authors: Dragoni E
Published: July 2007

A well-known theoretical equation for the distribution of contact load along threads in standard nut-bolt connections is generalized to incorporate the case of axially variable Young's moduli of the threaded elements. The influence of the material selection for homogeneous bolt and nut on the thread load concentration factor is initially addressed. The theoretical possibility of equalising the thread load distribution over the whole engagement by a convenient axial variation of the nut Young's modulus is then examined.
Elastic analysis of the flexed plate impact test
Authors: Reed P E
Published: July 2007

A linear elastic analysis for central loading of a circular plate, simply supported (unclamped) on a ring, is developed from established plate theory. The analysis includes equations for the force-deflection relationship until failure is initiated, and also the stresses due to bending within the loaded plate. Equations for the maximum stress in the central region where fracture initiates are given as a possible basis for failure criteria.

The analytical method is applied to a poly (methyl methacrylate) plate and compared with experimental data obtained from an instrumented falling weight impact test on the same material. Close agreement of theory with experiment is obtained until fracture initiates by radical cracking from the centre. A criterion of failure for the brittle material tested is proposed for the impact test, using strengths determined from a standard tensile test.