bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythrocruorin of Glossoscolex paulistus (Oligochaeta, Glossoscolecidae): Modulation of oxygen affinity by specific antibodies
Authors: Cardillo F. , de Paula E. , Oliveira G. R. , Marangoni S. , Oliveira B. , Meirelles N. C. 
Published: July 2007

Abstract1) The Soret region absorption spectrum of erythrocruorin (ERC) obtained from Glossoscolex paulistus, shows that oxy‐ERC has a maximum absorption peak at 416 nm while the deoxy‐ERC form has a maximum at 427 nm. 2) In the presence of a specific antiserum (anti‐ERC) and of anti‐ERC immunoglobulin G raised in rabbits, there is a deviation to low wavelengths in the maximum absorption peak of deoxy‐ERC while for the oxy form a red‐shift is noticed. These shifts accompanied an increased affinity of the hemeprotein for oxygen, possibly because of changes in the overall macromolecular conformation. 3) A decrease in the oxygen affinity of erythrocruorin is observed when large amounts of non‐specific serum are used. The same effect is observed in the presence of serum albumin, probably as a result of non‐specific binding between the albumin and erythrocruorin. 4) The fluorimetric titration of erythrocruorin with anti‐ERC Fab fragments results in a decrease in the intrinsic tryptophan fluorescence of the hemeprotein, a response indicative of a modification in the ERC's quaternary structure.
Captopril reverses high glucose‐induced effects on LLC‐PK1 cells partly by enhancing facilitative glucose transporter messenger RNA expressions
Authors: Yang Mei‐Li , Guh Jinn‐Yuh , Yang Yu‐Lin , Chang Chun‐Chang , Chuang Lea‐Yea 
Published: July 2007

AbstractOne of the mechanisms of angiotensin‐converting enzyme inhibitors in treating diabetic nephropathy is the reversal of renal hypertrophy. Hyperglycemia is the common denominator of all diabetic states. Thus, effects of captopril on high glucose (27.5 mM)‐induced alterations in LLC‐PK1 cells were studied as related to the facilitative glucose transporters. We found that high glucose (27.5 mM) inhibited mitogenesis and induced hypertrophy in these cells after 48 hours of culture concomitantly with decreased glucose transporter I messenger RNA expression. Captopril (1 mM) reversed the above effects concomitantly with enhancement of glucose transporter I and II messenger RNA expressions. We conclude that decreased expression of glucose transporter I may be associated with increased intracellular glucose and the resultant ill effects. Captopril reversed the above high glucose‐induced effects partly by enhancing glucose transporter I and II messsenger RNA expressions.
Erythrophagocytosis and its relation to band 3 clustering in chronic myelogenous leukemia
Authors: Das Amit K. , Sinha Ajay K. , Basu Joyoti 
Published: July 2007

AbstractBand 3, a major erythrocyte membrane glycoprotein, undergoes topographic redistribution leading to enhanced clustering, in chronic myelogenous leukemia (CML). This is probably due to the binding of heme compounds to the CML erythrocyte membrane resulting from depletion of cellular levels of reduced glutathione (GSH). Band 3 clustering appears to be one of the factors associated with increased erythrophagocytosis in CML
Behavior of uridine phosphorylase from Escherichia coli K‐12 in hydrated reversed micelles of surfactant in organic solvent
Authors: Kurganov B. I. , Burlakova A. A. , Chebotareva N. A. , Debabov V. G. 
Published: July 2007

AbstractThe catalytic activity of uridine phosphorylase from Escherichia coli K‐12 entrapped in hydrated reversed micelles of aerosol OT (AOT) in octane has been studied as a function of the degree of hydration of micelles. It was shown that the catalytic activity reaches maximum values at ratios [H20]/[AOT] equal to 8.4, 12.8, 16.1, and 18.6. On the basis of sedimentation data the conclusion has been made that the maximums of the catalytic activity of uridine phosphorylase correspond to monomenc, dimeric, trimeric, and tetrameric forms of the enzyme.
Stability and activity of potato acid phosphatase in aqueous surfactant media
Authors: Lalitha J. , Mulimani VH 
Published: July 2007

AbstractThe effect of three different classes of surfactants viz., anionic, cationic and neutral on catalytic activity of potato acid phosphatase (AcPase) was studied. Anionic surfactants bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) and sodium dodecyl sulfate (SDS) inhibited AcPase activity completely at 3 mM concentration. The cationic surfactant cetyltrimethylammonium bromide (CTAB), at 3.33 mM enhanced the activity by 20 per cent. Increase in CTAB concentration decreased the activity, so that only 50 per cent was retained at 27 mM concentration. Brij 35, a neutral surfactant also decreased the activity, whereas TritonX‐100 had little or no effect. At low CTAB concentration, an increase in Vmax and a decrease in Km was observed and the V/K ratio increased. TritonX‐100 enhanced Vmax without changing Km. The V/K ratio was also increased. The UV‐difference spectra of AcPase in presence of CTAB showed perturbations. The intensity of intrinsic fluorescence also enhanced in presence of CTAB.
Molecular cloning and growth hormone‐regulated gene expression of carp insulin‐like growth factor‐I
Authors: Hashimoto Hisashi , Mikawa Satoshi , Takayama Eiji , Yokoyama Yoshihiro , Toyohara Haruhiko , Sakaguchi Morihiko 
Published: July 2007

AbstractTwo distinct insulin‐like growth factor‐I (IGF‐1 cDNAs were isolated from a juvenile carp liver cDNA library. Both of the cDNAs encoded a full length prepro IGF‐I with 161 amino acids: a mature peptide (70 residues), its signal peptide (44 residues), and a carboxy‐terminal E domain (47 residues). The similarity of the two cDNA in the open reading frame was 95.1%. The amino acid sequences of E domain predicted by the two cDNAs were different while those of the signal peptide and the mature peptide were the same. By Northern blot analysis, four different sizes (1, 1.5, 2, and 4.5kb) of IGF‐I mRNA were recognized in the liver of juvenile carp. The two smaller species (lkb and 1.5kb) were not detected in adult carp. The expression of these two species was preferably induced by exogenous growth hormone administration in the liver of juvenile carp.
Mutation of Arg154 to Gly154 in urokinase augments its fibrin‐specificity
Authors: Peng Guihong , Ma Zhong , Kuai Letian , Zhu Dexu 
Published: July 2007

AbstractRscu‐PA and its mutant constructed by in vitro site specific mutagenesis of Arg154 in rscu‐PA to Gly154 (mscu‐PA) were both expressed in Escherichia coli. After in vitro denaturation and renaturation, the rscu‐PA and mscu‐PA were purified to homogeneity by Zn2+ selective precipitation, anti‐u‐PA IgG‐sepharose CL 4B affinity chromatography. After activation by plasmin, the kinetic constants for the resultant mtcu‐PA against synthetic substrate S2444 hydrolysis were found to be essentially identical to rtcu‐PA, suggesting that no impairment had been exerted on the catalytic active site of mtcu‐PA. However, both 125I‐fibrin plasma‐clot lysis and fibrinogenolysis showed that mtcu‐PA possessed a higher fibrinolytic activity but hardly any degradation of fibrinogen in plasma compared to rtcu‐PA and rscu‐PA. It was concluded that the substitution of Arg154 by Gly154 in tcu‐PA promoted the fibrin‐specificity of urokinase.
FcεRI‐ligation induces association of tyrosine phosphorylated proteins with SRC homology 2 domains of phospholipase Cγ1 in RBL‐2H3 rat basophilic leukemia cells
Authors: Han Mi Y. , Koh Woo S. , Yoon Sun Y. , Park Young M. , Choe Yong K. 
Published: July 2007

AbstractStimulation of the IgE receptors on mast cells and basophils activates protein tyrosine kinases and phosphotipases leading to histamine release. However, the mechanism by which protein tyrosine kinases regulate the phospholipases is not clearly defined yet. In this study, we examined the possibility that phospholipase Cγ1 associates with protein tyrosine kinases and tyrosine phosphorylated molecules as a result of activation of RBL‐2H3 cells, and that this association involves the Src homology 2 domains of phospholipase CγI. An increase in cytoplasmic Ca2+ level and tyrosine phosphorylations of proteins, including 72 and 40 kDa proteins, were observed after the cross‐linking of the IgE receptors on RBL‐2H3 rat basophilic cells by dinitrophenyl‐specific IgE and dinitrophenyl‐conjugated human serum albumin. Immunoprecipitation and coprecipitation experiments were performed to determine if the activation of protein tyrosine kinases is linked to the activation of phospholipase Cγ1 via its SH2 domains. Tyrosine phosphorylation of phospholipase Cγ1 was observed in 1 min following IgE receptor stimulation. Several proteins (72, 50, 40, and 33 kDa) were identified to be tyrosine phosphorytated and specifically associated with phospholipase Cγ1 by its Src homology 2 domains. In addition, the coprecipitated complex contains the tyrosine kinase activity which phosphorylates 72, 40, and 33 kDa proteins in the complex. In conclusion, these studies establish that tyrosine‐phosphorylated proteins of 72, 40, and 33 kDa associate with phospholipase Cγ1 via its SH2 domains following IgE receptor stimulation of RBL‐2H3 basophilic cells, implying that protein tyrosine kinases may tyrosine‐phosphorylate and recruit signaling proteins around the phospholipase Cγ1 and that phospholipase Cγ1 activation induces calcium mobilization, PKC activation and degranulation in mast cells or basophils.
Induction of mRNAs for ICAM‐1, VCAM‐1, and ELAM‐1 in cultured rat cardiac myocytes and myocardium in vivo
Authors: Hattori Yoshiyuki , Kasai Kikuo 
Published: July 2007

AbstractWe evaluated the expression of mRNAs for intercellular adhesion molecule‐1 (ICAM‐1), vascular cell adhesion molucule‐I (VCAM‐1), and endothelial leukocyte adhesion molecule‐1 (ELAM‐1) in cultured neonatal rat cardiac myocytes and in the rat heart by the reverse transcription‐polymerase chain reaction with gene specific primers. Bacterial lipopolysaccharide (LPS) and interferon‐γ induced gene expression for ICAM‐t, VCAM‐1, and ELAM‐1 in cultured cardiac myocytes. While mRNA for any of these adhesion molecules was very low or negligible in hearts of control rats, the three mRNAs were substantially induced in hearts 3h after the injection of LPS. Results show that mRNAs for the three inducible adhesion molecules are expressed in cultured cardiac myocytes and rat heart tissues and are enhanced by immune stimulation, suggesting their involvement in cardiac inflammatory disorders.
Effect of “βCATECHIN” on the life span of senescence accelerated mice (SAM‐P8 strain)
Authors: Kumari M.V. Ramana , Yoneda Tadashi , Hiramatsu Midori 
Published: July 2007

Abstract“βCATECHIN”, a preparation of natural vitamins and phytosubstances, has been designed as an “universal antioxidant” drink. Having previously demonstrated the scavenging action of a variety of free radicals by “βCATECHIN”, we now report the effect of its long renal administration on the life span of senescence accelerated mice (SAM‐P8), a routine model system that offers many characteristics of mammalian aging with a shortened life span. Both male and female SAM (age: 10 weeks) maintained on “βCATECHIN” containing drinking water (lml/kg b.w) showed significant extension of the mean life span as compared to their respective controls that received normal drinking water. Results show that administration of “βCATECHIN” increased the 50% mean survival rate by 8 weeks in case of female, and 7.5 weeks for male SAM. In addition to offering fresh evidence to the “free radical theory of aging”, the results emphasize on the importance of a daily supplement of natural antioxidants, especially as a combination, to achieve the goal of a long and disease‐free life.
Identification of two poly (A) Polymerases in Bacillus subtilis
Authors: Sarkar Bedabrata , Cao Gong‐jie , Sarkar Nilima 
Published: July 2007

AbstractTwo poly(A) polymerase activities were identified in extracts of a strain of Bacillus subtilis in which the gene for polynucleotide phosphorylase was disrupted. Gel filtration studies showed a large difference in the molecular size of the two poly(A) polymerases. On the other hand, the two enzymes resembled the two major poly(A) polymerases of Escherichia coli both with respect to size and in many of their catalytic properties. The observation that both B. subtilis and E. coli have two poly(A) polymerases with many common properties suggest interesting parallels in the processing of the 3′‐ends of mRNA in gram‐positive and gram‐negative bacteria.
Primary structure of the smallest (6.4‐kDa) subunit of human and bovine ubiquinol‐cytochrome c reductase deduced from cDNA seqences
Authors: Islam Mohammed M. , Suzuki Hiroshi , Yoneda Makoto , Tanaka Masashi 
Published: July 2007

AbstractAmino acid sequences of the smallest subunit of human and bovine ubiquinol‐cytochrome c reductase were deduced from nucleotide sequence of recombinant cDNA clones isolated by screening the corresponding cDNA libraries. Both proteins were composed of 56 amino acids. They were 84% homologous to each other in the coding nucleotide sequences and 88% homologous in the amino acid sequences. Southern blot analysis with human DNA suggested the presence of a single gene coding for the protein. Northern blot of human mRNAs from different tissues confirmed the existence of a single species of transcript among the tissues but the human gene is highly expressed in bioenergetically active tissues like heart and skeletal muscle.
Encystment ‐ specific mRNA is accumulated in the resting cysts of the ciliate Colpoda inflata
Authors: Benítez Laura , Gutiérrez Juan C. 
Published: July 2007

AbstractFrom a random amplified polymorphism cDNA study using vegetative, precystic and mature resting cysts of the ciliate Colpoda inflata, a stage‐specific fragment was isolated from the resting cyst cDNA population. This fragment was used as an encystment probe to study the corresponding mRNA expression during this eukaryotic cell differentiation process. This transcript is accumulated in the resting cyst of this ciliate, and it is the first time that accumulation of specific mRNA molecules associated with the ciliate cryptobiosis process is reported. The meaning of this stored mRNA in microbial cryptobiotic stages is discussed.
Regulation of the ferrochelatase gene expression during differentiation of mouse erythroleukemia cells
Authors: Furukawa Takako , Tokunaga Rikio , Taketani Shigeru 
Published: July 2007

AbstractFerrochelatase [EC 4.99.1.1], the last step enzyme of heme biosynthesis, is transcribed from a single promoter. The enzyme is ubiquitously expressed in all cells, while the transcription is induced during erythroid differentiation. In a transient transfection assay, we identified two cis‐acting elements involved in regulating the human ferrochelatase gene in mouse erythroleukemia (MEL) cells; one is the distal region (‐108 to ‐95) for the basic expression in erythroid and non‐erythroid cells, and the other is the proximal region (‐80 to ‐72) corresponding to the induced expression during differentiation of dimethylsulfoxide‐treated MEL cells. DNase I footprinting and gel mobility shift analyses revealed the presence of nuclear protein binding to the distal and the proximal regions, in both induced and uninduced MEL cells. These mean that two promoter regions play an important role in regulating the induced expression of ferrochelatase.
Modulation of sperm acrosomal exocytosis by guanyl nucleotides and G‐protein‐modifier agents
Authors: Brandelli Adriano 
Published: July 2007

AbstractMammalian sperm must undergo an exocytotic event during fertilization, the acrosome reaction (AR). This process is specifically induced by egg‐surface glycoproteins and it involves guanine nucleotide binding proteins (G‐proteins). Neoglycoproteins (NGP) with mannose or N‐acetylglucosamine residues has been demonstrated to induce the AR in human sperm. Activators of G‐proteins, like GTPγS, GppNHp, mastoparan and A1F4‐ were capable of inducing the AR, while other nucleotides or analogues did not. When sperm were preincubated with these agents and then with NGPs, only the G‐protein inhibitor GDPIβS decreased the AR rate. The preincubation of sperm with Pertussis toxin resulted in the inhibition of NGP‐induced AR, while no effect was observed with cholera toxin. Results indicate that direct activation of G‐proteins is sufficient to elicit the AR, and the induction of the AR in human sperm is mediated by N‐acetylglucosaminyl and mannosyl binding sites involving PTx‐sensitive G‐proteins similar to the induction by zona pellucida glycoproteins.
Interaction of interferon‐γ and epidermal growth factor in the regulation of nitric oxide production and cellular proliferation in a cultured murine mammary cell line, COMMA‐D
Authors: Low Boon Chuan , Prosser Colin G. , Lacasse Pierre , Grigor Murray R. 
Published: July 2007

AbstractThe regulation of nitric oxide synthase (NOS) activity and gene expression by cytokines and growth factors has been studied using the murine mammary epithelial cell line, COMMA‐D. NOS activity was stimulated by exposure to interferon‐γ (IFN‐γ) and could be further stimulated by tumour necrosis factor‐α (TNF‐α) and epidermal growth factor (EGF) although neither was affective alone. The maximal activity observed in the presence of IFN‐α and EGF was not affected by the order in which cells were exposed. Messenger RNA levels for the inducible NOS isoform were increased by IFN‐γ and TNF‐α in a manner consistent with the elevation of NOS activity. EGF also stimulated thymidine incorporation into DNA which was attenuated by coexposure with IFN‐γ in a manner that appeared to be largely NO‐independent.
TsTX‐VII, a new toxin from Tityus serrulatus scorpion venom able to induce the release of neurotransmitters from rat brain synaptosomes not blocked by tetrodotoxin
Authors: Sampaio Suely V. , Coutinho‐Netto J. , Arantes Eliane C. , Toyama Marcos H. , Novello José C. , Giglio José R. 
Published: July 2007

AbstractA procedure for the isolation of the toxin Tityustoxin VII (TsTX‐VII) from Tityus serrulatus scorpion venom and its biochemical characterization is reported. This protein has a Mr=6,700‐6,800, eight half‐cystine residues accounting for four disulfide bridges and no His. Its N‐terminal sequence GHZGYGS … characterizes it as a new toxin, able to release glutamic acid and gamma aminobutyric acid from rat brain synaptosomes “in vitro”. This release was also induced by the whole venom. Tetrodotoxin however blocked the effect of the whole venom but not that of TsTX‐VII, thus suggesting that the releasing mechanism by TsTX‐VII does not involve Na+ but perhaps K+ or Ca++ channels.
Enhanced in vivo catalytic activity of PEG‐modified cellulase complex from Trichoderma reesei
Authors: Mitra Gargi , Bachhawat Bimal K. 
Published: July 2007

AbstractThe cellulase complex from Trichoderma reesei was polyethylene glycol (PEG)‐modified with considerable retention of endo‐β‐1,4‐glucanase activity, as evaluated by the carboxymethylcellutase (CMCase) assay. While resistance towards heat denaturation was the same for either form, susceptibility towards proteolysis was slightly greater for the PEG‐conjugate, in contrast to most reports using other enzymes. The circulatory life of endoglucanase activity associated with the complex was enhanced upon PEG‐modification. This was confirmed by demonstrating degradation of chromogen‐tabelled substrate injected (i.v.) after 24hr of administration of the PEG‐ylated enzymes; in contrast the substrate remained undegraded in mice pretreated with the native complex. The PEG‐modified complex could be a good candidate for the treatment of pneumoconioses of textile workers exposed to cotton dust.
Isolation of the transferrin receptor from human placenta
Authors: Kanevsky Yu V. , Pozdnyakova L. P. , Katukov Yu V. , Severin S. E. 
Published: July 2007

AbstractThe transferrin receptor (TFR) has been detected in tissues characterised by a high degree of proliferation. We have developed a procedure for isolating TFR from human placental tissues by affinity chromatography on transferrin‐Sepharose. Using gel filtration and electrophoresis in 7% PAAG, it has been shown that the molecular mass of the protein is 180 kDa. The protein has a subunit structure and is made up of two identical subunits, 90 kDa each. The constant for the protein binding to transferrin is equal to 5×10‐9 M. The yield of the protein isolated by the novel procedure exceeds 5‐fold that obtained by previously described methods.
Inhibition of various isoforms of rat liver glutathione S‐transferases by tannic acid and butein
Authors: Zhang Kai , Mack Peter , Wong Kim Ping 
Published: July 2007

AbstractGlutathione S‐transferases (EC.2.5.1.18, GSTs) were purified from rat liver by S‐hexylglutathione affinity chromatography and six isoforms, namely C‐1, C‐2, C‐3, C‐4, A‐2 and A‐1, were isolated by CM‐cellulose and DEAE‐cellulose ion‐exchange columns. Tannic acid and butein showed varying degrees of inhibition on the six individual GST isoforms. When 1‐chloro‐2,4‐dinitrobenzene (CDNB) was used as a substrate, butein exerted significantly more potent inhibition on the cationic isoforms C‐2, C‐3 and C‐4 with IC50 values of 6.8, 8.5 and 8.0 μM respectively. All the isoforms showed lower activity towards p‐nitrobenzyt chloride when compared to CDNB and inhibition of the p‐nitrobenzyl chloride‐activity by tannic acid and butein was also weaker. The inhibitory effects of tannic acid and butein on each isoform decreased generally with increasing pH in the range of 6.0 to 8.0. The optimum pHs for inhibitions by tannic acid and butein on the six individual isoforms lie in the pH range of 6.0 to 6.5.
Quantification of epididymal retinoic acid‐binding protein (ERABP) mRNA in different anatomical regions of the adult rat epididymis
Authors: Hall Joseph C. , Tubbs Christopher E. 
Published: July 2007

AbstractEpididymal retinoic acid‐binding protein (ERABP), an 18.5 Kd androgen‐dependent protein, is synthesized and secreted by the rat epididymis. The concentration of ERABP mRNA in different anatomical regions of the rat epididymis was measured using quantitative reverse transcription polymerase chain reaction (RT‐PCR) and Northern blot analysis. While quantitative differences in the level of ERABP were observed in the caput region of the epididymis, no detectable levels of ERABP mRNA was observed in the corpus and cauda regions of the epididymis. In the caput region of the epididymis, 0.22 ng and 0.036 ng mRNA/gg of total RNA were measured in the proximal and distal segments of the caput region, respectively. These results indicate that ERABP is differentially expressed in the rat epididymis and suggest that the protein may be regulated at the level of transcription.
Stability of assembled epitopes on human chorionic gonadotropin to covalent modifications
Authors: Venkatesh N. , Murthy G. S. 
Published: July 2007

AbstractA measure of stability of a given epitope is an important parameter in the exploration of the utility of a desired MAb. It defines the conditions necessary for using MAbs as an investigative tool in several research methodologies and therapeutic protocols. Despite these obvious interests the lack of simple and rapid assay systems for quantitating MAb‐Ag interactions has largely hampered these studies. A single step MAb‐Solid Phase Radioimmunoassay (SS‐SPRIA), is described which eliminates errors that may arise with multistep sandwich assays. SS‐SPRIA has been used to demonstrate the differential stability of the assembled epitopes on gonadotropins. Differential stability towards specific reagents can be exploited to identify aminoacid residues at the epitopic site. Inactivation of an epitopic region is indicative of the presence of the group modified, provided conformational relaxations are not induced due to modifications at distant sites. Here we provide evidence to validate these conclusions.