bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of a transcript predicting an alternative form of sulfated glycoprotein‐2 (clusterin) in rat tissues
Authors: Izawa Masao 
Published: July 2007

AbstractAs a clue to understand the role of androgen in rat seminal vesicle, we have isolated several cDNA clones of androgen‐responsive mRNAs. During further characterizations of these cDNAs were in progress, a distinct cDNA clone designated p116 was isolated. The sequence study suggested the expression of a transcript predictding an alternative form of Sulfated Glycoprotein‐2 (SGP‐2)/clusterin. RT‐PCR demonstrated the androgen‐dependent expression of p116 transcript in the seminal vesicles. The transcript was also detectable in the ventral prostate, the liver and the thymus. Since SGP‐2 has been suggested as a classical molecular marker of apoptosis, p116 transcript newly identified in the present study might provide a useful probe to further understand the roles of SGP‐2 and its related proteins during the course of apoptotic process not only in male accessory sex organs, but also in many types of cells undergoing apoptosis.
Reverse transcription‐polymerase chain reaction (RT‐PCR) for direct detection of cucumber mosaic virus (CMV) in gladiolus
Authors: Raj S. K. , Saxena Sangeeta , Hallan Vipin , Singh B. P. 
Published: July 2007

AbstractA diagnostic method based on Reverse Transcription ‐ Polymerase Chain Reaction (RT‐PCR) was performed for detection of CMV genome directly in crude extracts of both healthy and infected gladiolus tissue using primers from the conserved sequences of CMV RNA‐3. RT‐PCR resulted in the amplification of 540 bp long fragment of CMV coat protein gene (CMV‐CP), as expected in most of the plant parts of infected gladiolus samples. Positive signals in Southern hybridization of amplified fragments with cloned CMV‐CP cDNA probe also confirmed the presence of CMV genome in gladiolus.
The stimulation of the mitochondrial permeability transition by dihydrolipoate and α‐lipoate
Authors: Saris Nils‐Erik L. , Karjalainen Ari , Teplova Vera V. , Lindros Kai O. 
Published: July 2007

AbstractThe effect of α‐lipoate and dihydrolipoate on the mitochondrial permeability transition was investigated. Both substances promoted the permeability transition in isolated rat liver mitochondria and in permeabilized hepatocytes, dihydrolipoate most potently in spite of it being a dithiol. The stimulation was prevented by Cyclosporin A or hydroxybutyltoluene but not by ascorbate. It is suggested that the greater potency of dihydrolipoate could be due to formation of a radical.
In vivo inhibition of Walker 256 tumour carnitine palmitoyltransferase I by soya oil dietary supplementation
Authors: Colquhoun Alison , de Mello Fábio E. P. , Curi Rui 
Published: July 2007

AbstractThe role of dietary fatty acids in the regulation of carnitine palmitoyltransferase (CPT) activity has been shown in liver but their role in the regulation of tumour CPT activity in vivo is unknown. The present study investigated the effects of several oils, given as dietary supplements, upon the activity of CPT I and II in the Walker 256 rat tumour and the inhibition or stimulation of tumour growth. CPT I activity was markedly inhibited by soya oil, rich in linoleic acid (70% inhibition vs control). CPT I mRNA expression was not inhibited by any of the oils studied, indeed soya oil caused a marked increase (132% vs control) in expression. These results suggest that soya oil can modulate, in vivo, the β‐oxidative pathway of tumour tissue and further supports the hypothesis of tumour CPT I regulation by polyunsaturated fatty acids.
Transition protein 1 from boar late spermatid nuclei having DNA‐melting activity is a dimeric protein
Authors: Akama Kuniko , Sato Hiroki , Hasegawa Shigeki , Shimada Ichio , Nakano Minoru 
Published: July 2007

AbstractPolyacrylamide gel electrophoretic behavior of boar transition protein 1, TP1, under dissociating and non‐dissociating buffer conditions, and titration of fluorescently labeled TP1 with increasing amounts of TP1 showed that TP1 formed a dimer without intermolecular disulfide bond. TP1 dimer with intermolecular disulfide bond had similar DNA‐melting activity to TP1, but was not detected in extracts from boar late spermatid nuclei. These results suggest that TP1 dimer without intermolecular disulfide bond induces local destabilization of DNA in the late spermatid nuclei.
Univalent cation fluxes in yeast
Authors: Lapathitis Georgios , Kotyk Arnost 
Published: July 2007

AbstractTransport of H+, K+, Rb+ and Tl+ ions was studied in a wild‐type strain of Saccharomyces cerevisiae and in its mutants defective in the high‐affinity K+ transport system TRK1 and in the double mutant with an additional deletion in the TRK2 gene. In the absence of glucose K+, Rb+ and Tl+ elicited a more or less stoichiometric exchange outflow of H+, in the mutants K+ moved out of cells even in the presence of 10 mM KCl or KNO3. In the presence of glucose in the wild type, K+, Rb+ and Tl+ brought about a massive outflow of H+ while being transported inward against high concentration gradients. In the trklΔ mutant the exchange fluxes were reduced by 65‐85%, in the double mutant those of K+, Rb+ and Tl+ practically cease but outflow of H+ caused by Tl+ remained at the level of the trklΔ mutant. It appears that, in addition to the H+ export by the PMAl‐coded plasma membrane H+‐ATPase, at least three different univalent‐cation involving activities are present: the high‐affinity transport system for K+ (TRK1), another system (possibly TRK2) with different responses to K+ and Rb+, vs. Tl+, and an active system for K+ export. The first two are apparently active exchange systems for K+, Rb+, and Tl+ against H+. The source of energy for these highly active transports (acting against gradients of 1000:1 and 5000:1, respectively) is unclear.
Studies on the heterologous expression of BstVI restriction endonuclease in Escherichia coli
Authors: Saavedra Claudia , González Enrique , Vásquez Claudio 
Published: July 2007

AbstractBacterial restriction and modification systems must be regulated to avoid self‐restriction. It is generally accepted that cognate DNA methyltransferases normally protects both, the host's chromosome and extrachromosomal elements from the activity of their endonuclease counterparts. When the bstVIRM genes from Bacillus stearothermophilusV were subcloned into Escherichia coli, several clones exhibiting a r+m‐ phenotype were originated. The present work was undertaken to analyze the possibility that mechanisms other than DNA methylation could account for the viability of these cells. No evidence was found for an inhibitory agent or endonuclease compartmentation. In vivo experiments showed that λ phage multiplication was poorly restricted by the heterologous enzyme. The restricting activity against the incoming phage increased however when phage adsortion was performed at higher temperatures. Analogous experiments in which a DNA‐repair deficient strain was used as a host for the thermophilic R‐M system suggested, to some extent, the participation of the repair machinery in the viability of r+m‐ clones.
A novel p53 mutation hotspot at codon 132 (AAG‐‐‐‐> AGG) in human renal cancer
Authors: Dahiya Rajvir , Deng Guoren , Selph Catherine , Carroll Peter , Presti Joseph 
Published: July 2007

AbstractMutations of p53 tumor suppressor gene are the most common genetic alterations in a variety of human carcinomas. The sites of p53 mutations, however, vary in different cancers. The present study was designed to characterize p53 mutations in 40 primary human renal cancer specimens using hot‐start‐PCR‐single‐strand conformation polymorphism (SSCP) analysis, sequencing of PCR product and immunohistochemistry. DNA extracted from microdissected paraffin‐embedded sections was amplified by hot‐start‐PCR using oligonucleotide primers specific for exons 4‐9 of p53. The mutations were analyzed by PCR‐SSCP technique and the generated fragments were denatured and analyzed by 6% polyacrylamide gel electrophoresis. The samples showing a band shift were denatured and sequenced using the SequenaseTM Version 2.0 DNA Sequencing Kit (US Biochemical, Cleveland, Ohio). Genomic DNA from control samples containing wild‐type p53 alleles was sequenced in parallel for confirming mutations in samples that were positive for p53 in the PCR‐SSCP analysis. The results of these experiments demonstrate that: (1) there were mutations in p53 exon 5 and 8 in 35% (14 out of 40 samples) of human renal cancer tissues as revealed by PCR‐SSCP analysis; (2) DNA sequencing of samples showing frame‐shift have hot spot of p53 mutation on exon 8 at codon 244 (GGC‐‐‐> TGC) and exon 5 at codon 132 [AAG(Lys)‐‐‐> AGG(Arg)]. This mutation in p53 exon 5 at codon 132 is novel and has not yet been reported; (3) immunohistochemical staining of p53 in renal cancer tissue using mouse anti‐human p53 monoclonal antibody, clone PAb 1801, correlated with the p53 mutation assessed by PCR‐SSCP. No correlation was found between p53 mutations and tumor stage and grade of renal cancer.
Influence of polyethylene glycol on lactate dehydrogenase
Authors: Lushchak Volodymyr I. 
Published: July 2007

AbstractIt is well established that polyethylene glycol (PEG) shifts the equilibrium in oligomeric protein systems to form higher molecular weight associates. We used this effect of PEG to evaluate a modification of functional properties of LDH from pig skeletal muscles. PEG decreases the rate of heating‐induced LDH inactivation in the concentration dependent manner. Michaelis constant and maximal velocity of the enzyme as well as inhibition of LDH by high pyruvate concentrations were affected by PEG. Enzyme preincubaion with PEG suppresses also the formation of ternary inactive complex NAD‐pyruvate‐LDH.
Detection of transmembrane helical segments at the nucleotide level in ukarayotic membrane protein genes
Authors: Lesnik T. , Reiss C. 
Published: July 2007

AbstractThe analysis of base distributions at the three codon positions, in sequences coding for polytopic membrane proteins from Eukaryotes, reveals a global excess of thymine and a depletion of adenine, at the second codon position. These genes were scanned using a sliding window, in which the average ratio of T over A at the second position of codons was computed. The scan shows that sharp peaks of this ratio, which are responsible for the high mean value of this parameter in the genes, correlate closely with the transmembrane segments of the membrane proteins. These results are quite similar to our previous findings for bacterial polytopic inner membrane proteins. This establishes the ratio of T over A at codon position two as a universal parameter for both the characterization of the genes of polytopic membrane proteins, and for the location of alpha‐helical, transmembrane segments of these proteins.
Inosine‐5′‐monophosphate analogues as inhibitors of human IMP cyclohydrolase and cellular growth
Authors: Szabados Eve , Manthey Michael K. , Wilson Paul K. , Christopherson Richard I. 
Published: July 2007

AbstractThe catalytic mechanism for the enzyme, IMP cyclohydrolase, may involve a reaction intermediate with negative charge in the 2‐position of the purine ring (Szabados, E., Hindmarsh, E., Phillips, L., Duggleby, R.G. & Christopherson, R.I. (1994) Biochemistry 33, 14237‐14245). Threeanalogues of IMP have been synthesised where fluorine, chlorine or bromine has been substituted in the 2‐position on the purine ring. These analogues with an electronegative substituent may resemble a reaction intermediate for IMP cyclohydrolase; 2‐fluoro IMP is a potent inhibitor of the enzyme with a Ki value of 0.19 μM, while 2‐chtoro IMP has a Ki of 1.9 μM and 2‐bromo IMP is not inhibitory. However, IMP cyclohydrolase is not inhibited in human CCRF‐CEM leukaemia cells exposed to 2‐fluoro inosine although it is toxic to these cells with an IC50 value of 4.9 μM.
The effect of ribosome‐inactivating proteins on the ribosome from the hyperthermophilic archaeon Sulfolobus solfataricus
Authors: Raimo Gennaro , Arcucci Alessandro , Masullo Mariorosario , Bocchini Vincenzo , Barbieri Luigi , Valbonesi Paola , Stirpe Fiorenzo 
Published: July 2007

AbstractProtein synthesis in the thermoacidophilic archaeon Sulfolobus solfataricus (Ss) was inhibited by polynucleotide:adenosine glycosylase activity of some type 1 ribosome‐inactivating proteins (RIP). The target of RIP was S. solfataricus rRNA that was depurinated thus producing inactive ribosomes. The amount of RIP required to half‐inactivated Ss‐ribosomes was comparable to that needed for eubacterial ribosomes, but two orders of magnitude higher than that required for mammalian ribosomes. In addition, RIP treated Ss‐ribosomes were also less efficient in stimulating the ribosome dependent GTPase activity of the S. solfataricus elongation factor 2 (SsEF‐2) thus suggesting that the inhibition of protein synthesis was probably due to the lack of the interaction between depurinated Ss‐ribosomes and SsEF‐2. Since SsEF‐2 protects Ss‐ribosomes against RIP activity it can be hypothesised that also on Ss‐ribosomes the sites of interaction for the translocation factor 2 and the RIP are topographically close.
Role of naturally occuring autoantibodies in senescence of normal and ATP depleted goat erythrocytes
Authors: Anwar Adil , Saleemuddin Mohammed 
Published: July 2007

AbstractThe possible role of autoantibodies in the senescence of goat erythrocytes has been investigated. For this purpose goat gammaglobulin was purified to homogenity and antigoat gammaglobulin was raised in rabbits. Using the peroxidase labelled antigoat gammaglobulin it was possible to detect the presence of auto anti band‐3 antibodies in goat sera. The goat erythrocytes were aged in vitro by ATP‐depletion, which resulted in appearence of a 52,000 mol. wt. polypeptide. The in vitro aged goat erythrocyte membrane bound substantial amounts of auto anti band‐3 antibodies as visualized by immumoblots.
Response to platelet‐derived growth factor by phenotypically different cultured human aortic smooth muscle cells
Authors: Kato Masahiro , Morimatsu Minoru , Tanimoto Akihide , Arima Nobuyuki , Sasaguri Yasuyuki 
Published: July 2007

AbstractWe investigated the effects of PDGF on DNA synthesis and mitogen‐activated protein (MAP) kinase activity, and demonstrated that the adult intimal SMC was concentration‐dependently stimulated by all PDGF isoforms in terms of both [3H]thymidine incorporation and MAP kinase activation, with PDGF‐BB and ‐AB being more potent than PDGF‐AA. The intimal SMCs and the neonatal SMCs showed a similar response with regard to MAP kinase activation. On the other hand, the intimal SMCs expressed many more PDGF receptors than the adult medial SMCs, which expressed a greater amount of PDGF‐A chain mRNA and showed a lesser response to PDGFs. These results suggest that the intimal SMCs have a relatively high potential to react to exogenous PDGFs, whereas the adult medial SMCs depend on endogenous or autocrine secretion of PDGF‐AA.
Effects on larvicidal activity of single proline substitutions in α3 or α4 of the Bacillus thuringiensis Cry4B toxin
Authors: Uawithya Panapat , Tuntitippawan Tipparat , Katzenmeier Gerd , Angsuthanasombat Chanan , Panyim Sakol 
Published: July 2007

AbstractThe possible role of α‐helices 3 and 4 in toxicity of the dipteran‐active Bacillus thuringiensis Cry4B δ‐endotoxin was investigated by employing proline substitutions via site‐directed mutagenesis. Similar to the wild‐type Cry4B, the mutant toxins were over‐expressed in Escherichia coli as cytoplasmic inclusions and were structurally stable upon solubilization and trypsin activation. The substitution of glutamine 149 by proline in the center of helix 4 (Q149P) resulted in a nearly complete loss of toxicity against Aedes aegypti mosquito‐larvae. However, single proline replacements near the center of helix 3 (V119P) and at the N‐terminus of helix 4 (Q140P) did not decrease larvicidal activity. The toxicity of E. coli cells expressing the wild‐type toxin was significantly reduced by two‐hour preincubation with the non‐toxic mutant (Q149P), thus indicating that the primary binding step was not affected by the proline substitution in helix 4. The results therefore reveal a crucial role for helix 4 of the Cry4B toxin in toxicity, possibly in membrane insertion and pore formation rather than in receptor recognition.
Identification of new GATA factor family genes in Saccharomyces cerevisiae and Schizosaccharomyces pombe
Authors: Hoe Kwang‐Lae , Chung Kyung‐Sook , Won Misun , Yoo Ook‐Joon , Yoo Hyang‐Sook 
Published: July 2007

AbstractBy genomic Southern hybridization using degenerate oligo probes corresponding to the conserved zinc finger of the GATA family, four and three new GATA‐factor genes were detected in Saccharomyces cerevisiae and Schizosaccharomyces pombe, respectively. Through degenerate PCR and Southern hybridization using an internal probe between the PCR primers, a new GATA‐factor gene of S. pombe, gafl, was identified. The DNA sequence analysis revealed that the partial gafl gene contains the strictly conserved zinc finger which is the hallmark of the GATA family. As judged form the codon usage of leucine in the zinc finger probe, the zinc fingers of S. pombe are more similar to those of higher fungi than those of S. cerevisiae, and this means that S. pombe is phylogenically close to higher organisms than S. cerevisiae.
V1a receptor mRNA expression in mouse early proximal tubule (S1) cell line is regulated by protein kinase A
Authors: Takeda Michio , Kobayashi Mami , Shirato Isao , Endou Hitoshi 
Published: July 2007

AbstractThe purpose of this study was to investigate the regulation of V1a receptor gene expression in mouse early proximal tubule (S1) cell line (NF‐5). NF‐5 cells showed arginine vasopressin (AVP)‐induced increase in cytosolic free calcium concentration mediated by V1a receptor. Polymerase chain reaction coupled with reverse transcription analysis revealed that forskolin, but not phorbol‐12‐myristate‐13‐acetate stimulated V1a receptor mRNA expression in NF‐5 cells. Our data suggest that V1a receptor gene expression is regulated by protein kinase A in proximal tubule cell line, and the cell line might be a useful model for the further studies of the function and the regulation of the activity and expression of the V1a receptor in the proximal tubule.
Spectroscopic studies of the interactions of the pyrethroid insecticide fenvalerate with gramicidin
Authors: Ghosh J. K. , Sarkar S. N. , Sikdar S. K. 
Published: July 2007

AbstractFenvalerate is a pyrethroid insecticide which interacts with ionic channels. Using circular dichroism technique we have studied the interaction of fenvalerate with gramicidin, a model channel peptide which transports ions. In most organic solvents, gramicidin exists as a double helix except in trifluoroethanol where it exists as a channel forming single stranded β6.3 helical monomer. In model lipid membranes, under certain experimental conditions, gramicidin exists as a channel forming single stranded β6.3 helical dimer. Our results show that fenvalerate interacts more with the single stranded β6.3 helical monomer or dimer than with the double helical form of gramicidin. This was further confirmed by an increase in the rate of gramicidin mediated proton transport in liposomes by fenvalerate, using the pH sensitive fluorophore, pyranine.
Variations in gene expression and genomic stability of human hepatoma cells integrated with hepatitis B virus DNA
Authors: Kuo Kou‐Wha , Yang Pei‐Yi , Huang Yu‐Sheng , Shieh Dar‐Zen 
Published: July 2007

AbstractThe association of hepatitis B virus (HBV) infection with human hepatoma is well established. However, no consensus regarding the etiology of hepatocellular carcinoma was elucidated. In this paper, the genomic stability and gene expression of HBV DNA‐integrated and non‐integrated hepatoma cells by Transcript Profile (TP)‐PCR and RT‐PCR are characterized. The additional DNA bands generated from TP‐PCR of HBV integrated genomes were not correlated with the sequence of HBV, suggesting that the variations may result from genomic instability of the host cells. Moreover, differential genes expressed in HBV DNA‐integrated cells were sequenced. A cDNA generated from the integrated cells exhibited 99.3% homology with the sequences of ATP synthase 6 and cytochrome C oxidase III, but the sequences were abnormally linked together. Since HBV infection may alter the energy metabolism of the cell, the results suggest that the integration may cause mitochondriae defects in the ATP synthase 6 and cytochrome C oxidase III genes.
Effects of short‐ and long‐term exposure to linoleic acid hydroperoxide on cytosolic calcium ion level of human aortic intimal smooth muscle cells In vitro
Authors: Arima Nobuyuki , Sasaguri Yasuyuki , Yagi Kunio 
Published: July 2007

AbstractWhen cultured intimal smooth muscle cells from human aorta were exposed for a short period of time (25 sec) to linoleic acid hydroperoxide (100 nmol/ml), influx of calcium ions into the cytosol of these cells was provoked, and a temporal increase in cytosolic calcium ion level was observed. Two calcium channel blockers inhibited this influx. Long‐term exposure (4 min) of these cells to the hydroperoxide also provoked the influx of calcium ions, which resulted in a longer time of the calcium ion increase. In the latter case, however, the calcium channel blocker inhibited the initial influx, but then the influx started and continued even in the presence of the blocker. Such difference in exposure time‐dependent effects should be taken into account in considering pathological roles of lipid hydroperoxides.
Effects of ethanol ingestion on insulin binding to rat leydig cells
Authors: Srikanth V. , Shanthakumari D. , Sudha S. , Govindarajulu P. , Balasubramanian K. 
Published: July 2007

AbstractEffects of ethanol treatment and its withdrawal on insulin binding to isolated rat Leydig cells were Studied. Mature rats were given ethanol by gastric intubation for 30 days at a dose of 3.0g/kg body weight, twice daily, as a 25% (v/v) aqueous solution and treatment was withdrawn for the subsequent 30 days in an another group. Ethanol treatment markedly increased serum insulin and reduced the 125I‐insulin binding to Leydig cells and the activities of Leydig cellular steroidogenic enzymes such as 3β‐HSD and 17β‐HSD. Withdrawal of ethanol treatment restored these changed values to their normal levels. The results suggest the possible involvement of subnormal insulin actions, as that of LH, in the ethanol‐induced impairment of Leydig cellular steroidogenesis and the resulting hypoandrogenization associated with alcohol abuse.
The inhibitory effect of benzodiazepine derivatives on the bovine lens aldose reductase enzyme
Authors: Evcimen Net Das , Pekiner Bilgehan , Süzen Sibel , Büyübingöl Erdem 
Published: July 2007

AbstractThe aldose reductase enzyme, involved in the sorbitol pathway which is an important mechanism in regulation of mammalian glucose metabolism, has been known to play a significant role in the initiation of diabetic complications. Numerous chemical substances have been prepared in order to improve the pharmacological profile of inhibition of aldose reductase enzyme. In this study, aldose reductase inhibitory activities of several benzodiazepine derivatives were investigated. The enzyme was obtained from bovine lenses via the ammonium sulphate‐protein out method with several steps. It was found that tetrazepam had a significant inhibitor potency among the other benzodiazepine derivatives showing very slight inhibitor activities that are indicated in terms of percent inhibitor potency at 10‐4 M concentration.