bluuebunny/crossref_metadata_2025 huggingface dataset:
Eutopic production of human chorionic gonadotropin β (hCGβ) and luteinizing hormone β (hLHβ) in the human testis
Authors: Berger P. , Kranewitter W. , Madersbacher S. , Gerth R. , Geley S. , Dirnhofer S.
Published: July 2002

The classical pregnancy and tumor marker hCG has long been considered to be only accidentally expressed ectopically, e.g. by tumors. The biological functions of low levels of bCGβ, hCGα and holo‐hCG in the sera of nonpregnant healthy individuals remained unclear. Immunological analyses by our ultrasensitive time‐resolved fluoroimmunoassays revealed a concentration gradient from < 5 pg hCG in cubital vein serum versus up to 480 pg hCG in the corresponding benign testicular hydrocele fluids. Moreover, hCGβ and its cognate molecule luteinizing hormone β (LHβ) were present in cytosolic extracts of normal human testes. Both hCGβ and hLHβ are eutopically produced as proven by RT‐PCR and subsequent Southern and dot blot analyses. Thus, the view of a purely systemic hormonal function of hLH, and of hCG during pregnancy needs a reassessement as hCGβ and hLHβ are synthesized in the human testis and autocrine/paracrine actions seem to be likely.
Effect of potential binding site overlap to binding of cellulose to cellulose: a two‐dimensional simulation
Authors: Sild Veljo , Ståhlberg Jerry , Pettersson Göran , Johansson Gunnar
Published: July 2002

A computer simulation model for the binding of ligands to a totally anisotropic surface (infinite two‐dimensional square lattice) with overlapping binding sites has been developed. The validity of the simulation has been proven by comparison with cases where the correct results are known. The simulation of kinetics shows that when the lattice is close to saturation, the true equilibrium state is reached extremely slowly due to a lot of rearranging of the ligands on the lattice. Based on these findings, the terms ‘apparent saturation’ and ‘apparent maximum coverage’ have been introduced and defined. The largest discrepancies between ‘apparent maximum coverage’ and the theoretically predicted value were observed for tigands of large size and/or irregular shape. As an example, the model has been applied to describe the binding of cellobiohydrolase‐I core to Avicel. A formula for calculation of the intrinsic binding constant, maximal binding capacity and specific surface of cellulose from real binding data has been derived.
Involvement of intracellular Ca2+ in oxidant‐induced NF‐κB activation
Authors: Sen Chandan K. , Roy Sashwati , Packer Lester
Published: July 2002

In human Jurkat T cells and its subclone Wurzburg cells oxidant challenge elevated [Ca2+]i by mobilizing Ca2+ from intracellular stores. In Jurkat cells this effect was rapid and transient, but in Wurzburg cells the response was slow and sustained. H202‐induced NF‐κB activation in Wurzburg cells was not influenced by the presence of extracellular EGTA but was totally inhibited in cells that were loaded with esterified EGTA. In Jurkat cells that are not sensitive to H202‐induced NF‐κB activation, H202 potentiated NF‐κB activation in the presence of sustained high [Ca2+]i following thapsigargin treatment. NF‐κB regulatory effect of α‐lipoate and N‐acetylcysteine appeared to be, at least in part, due to their ability to stabilize elevation of [Ca2+]i following oxidant challenge. Results of this study indicate that a sustained elevated [Ca2+]i is a significant factor in oxidant‐induced NF‐κB activation.
Evidence that the glucoamylases and α‐amylase secreted by Aspergillus niger are proteolytically processed products of a precursor enzyme
Authors: Dubey A.K. , Suresh C. , Kavitha R. , Karanth N.G. , Umesh-Kumar S.
Published: July 2002

A 125‐kDa starch hydrolysing enzyme of Aspergillus niger characterised by its ability to dextrinise and saccharify starch [Suresh et al. (1999) Appl. Microbiol. Biotechnol. 51, 673–675] was also found to possess activity towards raw starch. Segregation of these activities in the 71‐kDa glucoamylase and a 53‐kDa α‐amylase‐like enzyme supported by antibody cross‐reactivity studies and the isolation of mutants based on assay screens for the secretion of particular enzyme forms revealed the 125‐kDa starch hydrolysing enzyme as their precursor. N‐terminal sequence analysis further revealed that the 71‐kDa glucoamylase was the N‐terminal product of the precursor enzyme. Immunological cross reactivity of the 53‐kDa amylase with antibodies raised against the precursor enzyme but not with the 71‐ and 61‐kDa glucoamylase antibodies suggested that this enzyme activity is represented by the C‐terminal fragment of the precursor. The N‐terminal sequence of the 53‐kDa protein showed similarity to the reported Taka amylase of Aspergillus oryzae. Antibody cross‐reactivity to a 10‐kDa non‐enzymic peptide and a 61‐kDa glucoamylase described these proteins as products of the 71‐kDa glucoamylase. Identification of only the precursor starch hydrolysing enzyme in the protein extracts of fungal protoplasts suggested proteolytic processing in the cellular periplasmic space as the cause for the secretion of multiple forms of amylases by A. niger.
Crystal structure of SULT2A3, human hydroxysteroid sulfotransferase
Authors: Pedersen Lars C , Petrotchenko Evgeniy V , Negishi Masahiko
Published: July 2002

The crystal structure of SULT2A3 human hydroxysteroid sulfotransferase has been solved at 2.4 Å resolution in the presence of 3′‐phosphoadenosine 5′‐phosphate (PAP). The overall structure is similar to those of SULT1 enzymes such as estrogen sulfotransferase and the PAP binding site is conserved, however, significant differences exist in the positions of loops Pro14–Ser20, Glu79–Ile82 and Tyr234–Gln244 in the substrate binding pocket. Moreover, protein interaction in the crystal structure has revealed a possible dimer‐directed conformational alteration that may regulate the SULT activity.
Alternative 5′‐exons of the mouse cAMP‐dependent protein kinase subunit RIα gene are conserved and expressed in both a ubiquitous and tissue‐restricted fashion
Authors: Barradeau S. , Imaizumi-Scherrer T. , Weiss M.C. , Faust D.M.
Published: July 2002

The activity of cAMP‐dependent protein kinase is controlled by its regulatory subunits. Mouse RIα regulatory subunit expression is initiated from five different non‐coding 5′‐regions (exons 1a, 1b, 1c, 1d and 1e). This organization appears to be conserved among species. All mouse tissues accumulate exon 1a and 1b transcripts and most contain more 1b than 1a, except brain, heart and oesophagus. Exon 1d and 1e transcripts are found in several tissues, while exon 1c is testis‐specific. All five transcripts are in RIα‐rich tissues: gonads and adrenal glands.
The galactose‐binding and mannose‐binding jacalin‐related lectins are located in different sub‐cellular compartments
Authors: Peumans Willy J. , Hause Bettina , Van Damme Els J.M.
Published: July 2002

A galactose‐specific and a mannose‐specific lectin of the family of the jacalin‐related lectins have been localized by immunofluorescence microscopy. The present localization studies provide for the first time unambiguous evidence for the cytoplasmic location of the mannose‐specific jacalin‐related lectin from rhizomes of Calystegia sepium, which definitely differs from the vacuolar location of the galactose‐specific jacalin from Artocarpus integrifolia. These observations support the hypothesis that the galactose‐specific jacalin‐related lectins evolved from their mannose‐specific homologues through the acquisition of vacuolar targeting sequences.
Activation of endogenous c‐Src or a related tyrosine kinase by intracellular (pY)EEI peptide increases voltage‐operated calcium channel currents in rabbit ear artery cells
Authors: Wijetunge S. , Hughes A.D.
Published: July 2002

The effect of activation of endogenous c‐Src tyrosine kinase by (pY)EEI peptide was examined on voltage‐operated calcium channel (VOC) currents in arterial smooth muscle cells. In single rabbit ear artery cells intracellular application of (pY)EEI peptide increased calcium channel currents. Inactive, non‐phosphorylated YEEI peptide had no effect on currents. Peptide‐A, a 21 amino acid inhibitor of c‐Src inhibited currents and prevented the effect of (pY)EEI peptide on calcium channel currents. These results indicate that activation of intrinsic c‐Src increases VOC and support a role for c‐Src in the regulation of VOC in vascular smooth muscle cells.
Expression of a 26S proteasome ATPase subunit, MS73, in muscles that undergo developmentally programmed cell death, and its control by ecdysteroid hormones in the insect Manduca sexta
Authors: Löw P , Bussell K , Dawson S.P , Billett M.A , Mayer R.J , Reynolds S.E
Published: July 2002

MS73, an ATPase regulatory subunit of the 26S proteasome in the moth Manduca sexta, is shown to be expressed at a high level only in muscles that are undergoing developmentally programmed cell death, or which are destined to do so. The amount of MS73 is increased by more than two‐fold just before death in each of three different muscles that die at different times, under different developmental controls. An ecdysteroid (moulting hormone) agonist, RH‐5849, that prevents the occurrence of programmed cell death in two of these muscles also prevents the normally occurring rise in level of MS73 in these muscles. This evidence is consistent with a role for MS73 in programmed cell death.
Human metallothionein gene MT1L mRNA is present in several human tissues but is unlikely to produce a metallothionein protein
Authors: Holloway Adele F , Stennard Fiona A , West Adrian K
Published: July 2002

© 1997 Federation of European Biochemical Societies.
A novel delta‐endotoxin gene cryIM from Bacillus thuringiensis ssp. wuhanensis
Authors: Shevelev A.B , Kogan Ya.N , Bushueva A.M , Voronina E.J , Rebrikov D.V , Novikova S.I , Chestukhina G.G , Kuvshinov V , Pehu E , Stepanov V.M
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Identification of novel heparin‐binding domains of vitronectin
Authors: Liang Olin D , Rosenblatt Sylvia , Chhatwal Gursharan S , Preissner Klaus T
Published: July 2002

Vitronectin is a multifunctional serum protein which provides a unique regulatory link between cell adhesion, humoral defense mechanism and the hemostatic system, and the heparin‐binding properties of vitronectin are thought to have participated in various functional aspects. In addition to the carboxy‐terminal glycosaminoglycan‐binding motif, we report on two novel heparin‐binding domains which were identified using phage display technique. One heparin‐binding domain is located between amino acids Asp82 and Cys137 at the end of the connector region, while the other is in the second hemopexin‐type repeat, between amino acids Lys175 and Asp219 of the vitronectin molecule. Our findings may shed new light to the activities of vitronectin and its binding to cells, which could not be explained solely on the basis of the known heparin‐binding domain.
Differential effects of five types of antipathogenic plant peptides on model membranes
Authors: Caaveiro José Manuel M , Molina Antonio , González-Mañas Juan M , Rodrı́guez-Palenzuela Pablo , Garcı́a-Olmedo Francisco , Goñi Félix M
Published: July 2002

The effects of five antipathogenic plant peptides, wheat α‐thionin, potato PTH1 defensin, barley LTP2 lipid transfer protein, and potato tuber DL1 and DL2 defensins, have been tested against phospholipid vesicles (liposomes). Wheat thionin very actively induces aggregation and leakage of negatively charged vesicles. LTP2 displays the same activities, although to a limited extent. Under certain conditions PTH1 and DL2 induce vesicle aggregation, but not leakage. Potato defensin DL1 failed to show any effect on liposomes. The same peptides have been assayed against a plant pathogenic bacterium, both the membrane‐active and ‐inactive compounds having efficient antibacterial action.
The pag gene product, a physiological inhibitor of c‐abl tyrosine kinase, is overexpressed in cells entering S phase and by contact with agents inducing oxidative stress
Authors: Prospéri Marie-Thérèse , Ferbus Didier , Rouillard Dany , Goubin Gérard
Published: July 2002

The human pag gene product is an inhibitor of the c‐abl tyrosine kinase and belongs to a new family of proteins. We show here that higher levels of pag gene expression are observed following induction of proliferation and contact with compounds inducing oxidative stress such as diethyl maleate and sodium arsenate. A weaker overexpression is seen in a macrophage cell line using hydrogen peroxide or menadione as inducers. Pag gene expression increases in synchronized cells entering the S phase. This raises the possibility that elevated levels of pag counteract the cytostatic activity of abl. Treatment of growth arrested cells with diethyl maleate and sodium arsenate induces pag gene overexpression, independently of cell proliferation. Thus, enhanced pag gene expression occurs in two cellular events: proliferation and response to oxidative stress.
Cross‐inhibition of both estrogen receptor α and β pathways by each dominant negative mutant
Authors: Ogawa Sumito , Inoue Satoshi , Orimo Akira , Hosoi Takayuki , Ouchi Yasuyoshi , Muramatsu Masami
Published: July 2002

Both estrogen receptor α (ERα) and the recently identified ERβ are nuclear receptors that are activated by estrogen. It was reported that ERα and ERβ form heterodimers. Here, we show that they activate transcription independently rather than synergistically via estrogen response elements (ERE). To show the cross‐talk between ERα and ERβ, we utilized dominant negative mutants of ERs constructed by C‐terminal truncation. Interestingly, ERα1–530 inhibited transactivation not only by ERα but also by ERβ, whereas ERβ1–481 inhibited transactivation by ERα as well as by ERβ. The GST pull‐down assay also demonstrated the cross‐interaction of these mutants with wild‐type ERα and ERβ. Thus, we found dominant negative mutants that block both ERα and ERβ signaling pathways.
Targeted cleavage of HIV‐1 envelope gene by a DNA enzyme and inhibition of HIV‐1 envelope‐CD4 mediated cell fusion
Authors: Dash Bipin C , Harikrishnan T.A , Goila Ritu , Shahi Shweta , Unwalla Hoshang , Husain Sajid , Banerjea Akhil C
Published: July 2002

With the ultimate aim of developing an effective antiviral strategy against HIV‐1, a mono‐DNA enzyme possessing the 10–23 catalytic motif [Santoro and Joyce (1997) Proc. Natl. Acad. Sci. USA 94, 4264–4266] was synthesized against the HIV‐1 envelope gene. We tested the in vitro cleavage efficiency of the 178 bp long truncated HIV‐1 Env transcript by DNA enzyme 6339. Protein independent and Mg2+ dependent specific cleavage products were obtained. As soon as 5 min after mixing equimolar concentrations of DNA enzyme and substrate RNA, more than 50% cleavage was observed which increased steadily over a period of 4 h. Very little cleavage was obtained at 1 mM MgCl2 concentration which improved significantly when the concentration of MgCl2 was increased up to 20 mM. Specific inhibition of cell membrane fusion caused by the interaction of gp160 and CD4 in HeLa cells was observed when the above DNA enzyme was used. Thus, these chemically synthesized DNA enzymes could prove to be very useful for in vivo application.
The KCNQ2 potassium channel: splice variants, functional and developmental expression. Brain localization and comparison with KCNQ3
Authors: Tinel Norbert , Lauritzen Inger , Chouabe Christophe , Lazdunski Michel , Borsotto Marc
Published: July 2002

Benign familial neonatal convulsions, an autosomal dominant epilepsy of newborns, are linked to mutations affecting two six‐transmembrane potassium channels, KCNQ2 and KCNQ3. We isolated four splice variants of KCNQ2 in human brain. Two forms generate, after transient expression in COS cells, a potassium‐selective current similar to the KCNQ1 current. L‐735,821, a benzodiazepine molecule which inhibits the KCNQ1 channel activity (EC50=0.08 μM), also blocks KCNQ2 currents (EC50=1.5 μM). Using in situ hybridization, KCNQ2 and KCNQ3 have been localized within the central nervous system, in which they are expressed in the same areas, mainly in the hippocampus, the neocortex and the cerebellar cortex. During brain development, KCNQ3 is expressed later than KCNQ2.
Cloning, molecular analysis and differential cell localisation of the p36 RACK analogue antigen from the parasite protozoon Crithidia fasciculata1
Authors: Taladriz Soraya , Gonzalez-Aseguinolaza Gloria , Marquet Alberto , Larraga Vicente
Published: July 2002

The family of the RACK molecules (receptors for activated C kinases) are present in all the species studied so far. In the genus Leishmania, these molecules also induce a strong immune reaction against the infection. We have cloned and characterised the gene that encodes the RACK analogue from the parasite trypanosomatid Crithidia fasciculata (CACK). The molecule seems to be encoded by two genes. The sequence analysis of the cloned open reading frame indicates the existence of a high degree of conservation not only with other members of the Trypanosomatidae but also with mammalians. The study of the protein kinase C phosphorylation sites shows the presence of three of them, shared with the mammalian species, additional to those present in the other protozoa suggesting a certain phylogenetic distance between the protozoon Crithidia fasciculata and the rest of the Trypanosomatidae. The CACK‐encoded polypeptide shows an additional sequence of four amino acids at the carboxy‐terminal end, which produces a different folding of the fragment with the presence of an α‐helix instead of the β‐sheet usual in all the other species studied. A similar result is elicited at the amino‐terminal end by the change of three amino acid residues. The immunolocalisation experiments show that the CACK displays a pattern with a distribution mainly at the plasma membrane, different from that of the related Leishmania species used as control, that displays a distribution close to the nucleus. Altogether, the data suggest that the existence of the structural differences found may have functional consequences.
Mitochondrial DNA sequence diversity in Russians
Authors: Orekhov Vladimir , Poltoraus Andrey , Zhivotovsky Lev A. , Spitsyn Viktor , Ivanov Pavel , Yankovsky Nikolay
Published: July 2002

The article presents the results of the first regular study of Russian populations by sequencing the control region of mitochondrial DNA (mtDNA). The sequenced region is the most variable on mtDNA molecule and is commonly used for population and evolutionary studies. Russians form one of the largest ethnic groups (more than 129 million). However, their genetic diversity had only been characterized with RFLP and biochemical markers, although there are already established mtDNA sequence databases for many ethnic groups of the world. We have obtained sequence data from 103 individuals living in three Russian regions: Kostroma, Kursk, and Rjazan. The sequenced fragment analyzed is 360 bp in length (positions from 16024 to 16383). Fifty nine nucleotide positions have been found polymorphic in Russians, among those were 57 transitions and two transversions. One individual is found having two insertions of two cytosines between positions 16184 and 16193. Among 64 different mitotypes identified in the study 52 were unique in these samples. The index of genetic diversity (Nei, 1987) for Russians is 0.96. This value is within the established range for European populations (0.93 to 0.98). Genetic distances calculated from our data show that Russians form a cluster with Germans, Bulgarians, Swedes, Estonians, and Volgo‐Finns are more distant from Karelians and Finns, and much more differ from Turks and especially Mongolians.
Phosphorylated seryl and threonyl, but not tyrosyl, residues are efficient specificity determinants for GSK‐3β and Shaggy
Authors: Williams Daniel D , Marin Oriano , Pinna Lorenzo A , Proud Christopher G
Published: July 2002

Glycogen synthase kinase‐3 is involved in diverse functions including insulin signalling and development. In a number of substrates, phosphorylation by glycogen synthase kinase‐3 is known to require prior phosphorylation at a Ser in the +4 position relative to its own phosphorylation site. Here we have used synthetic peptides derived from a putative glycogen synthase kinase‐3 site in the Drosophila translation initiation factor eIF2Bϵ to investigate the efficacy of residues other than Ser(P) as priming residues for glycogen synthase kinase‐3β and its Drosophila homologue Shaggy. glycogen synthase kinase‐3β phosphorylated peptides with Ser(P) and Thr(P) in the priming position, but peptides with Tyr(P), Thr, Glu or Asp were not phosphorylated. The V
max for the Thr(P) peptide was three times higher than that of the Ser(P) peptide. These data suggest that glycogen synthase kinase‐3 is unique among phosphate‐directed kinases. The priming site specificity of Shaggy is similar to that of mammalian glycogen synthase kinase‐3β. This unpredicted efficacy of Thr(P) in the priming position suggests that there may be other unidentified substrates for these kinases.
Contribution of separate tryptophan residues to intrinsic fluorescence of actin. Analysis of 3D structure
Authors: Kuznetsova I.M. , Yakusheva T.A. , Turoverov K.K.
Published: July 2002

The location of tryptophan residues in the actin macromolecule was studied on the basis of the known 3D structure. For every tryptophan residue the polarity and packing density of their microenvironments were evaluated. To estimate the accessibility of the tryptophan residues to the solvent molecules it was proposed to analyze the radial dependence of the packing density of atoms in the macromolecule about the geometric center of the indole rings of the tryptophan residues. The proposed analysis revealed that the microenvironment of tryptophan residues Trp‐340 and Trp‐356 has a very high density. So these residues can be regarded as internal and inaccessible to solvent molecules. Their microenvironment is mainly formed by non‐polar groups of protein. Though the packing density of the Trp‐86 microenvironment is lower, this tryptophan residue is apparently also inaccessible to solvent molecules, as it is located in the inner region of macromolecule. Tryptophan residue Trp‐79 is external and accessible to the solvent. All residues that can affect tryptophan fluorescence were revealed. It was found that in the close vicinity of tryptophan residues Trp‐79 and Trp‐86 there are a number of sulfur atoms of cysteine and methionine residues that are known to be effective quenchers of tryptophan fluorescence. The most essential is the location of SG atom of Cys‐10 near the NE1 atom of the indole ring of tryptophan residue Trp‐86. On the basis of microenvironment analysis of these tryptophan residues and the evaluation of energy transfer between them it was concluded that the contribution of tryptophan residues Trp‐79 and Trp‐86 must be low. Intrinsic fluorescence of actin must be mainly determined by two other tryptophan residues – Trp‐340 and Trp‐356. It is possible that the unstrained conformation of tryptophan residue Trp‐340 and the existence of aromatic rings of tyrosine and phenylalanine and proline residues in the microenvironments of tryptophan residues Trp‐340 and Trp‐356 are also essential to their blue fluorescence spectrum.
Mildly oxidized GAPDH: the coupling of the dehydrogenase and acyl phosphatase activities
Authors: Schmalhausen Elena V. , Nagradova Natalya K. , Boschi-Muller Sandrine , Branlant Guy , Muronetz Vladimir I.
Published: July 2002

The hydrogen peroxide‐induced ‘non‐phosphorylating’ activity of D‐glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) is shown to be a result of the successive action of two forms of the enzyme subunits: one catalyzing production of 1,3‐bisphosphoglycerate, and the other performing its hydrolytic decomposition. The latter form is produced by mild oxidation of GAPDH in the presence of a low hydrogen peroxide concentration when essential Cys‐149 is oxidized to the sulfenate derivative. The results obtained with a C153S mutant of Bacillus stearothermophilus GAPDH rule out the possibility that intrasubunit acyl transfer between Cys‐149 and a sulfenic form of Cys‐153 is required for the ‘non‐phosphorylating’ activity of the enzyme.
Ap4A induces apoptosis in human cultured cells
Authors: Vartanian Amalia , Alexandrov Ivan , Prudowski Igor , McLennan Alexander , Kisselev Lev
Published: July 2002

Diadenosine oligophosphates (ApnA) have been proposed as intracellular and extracellular signaling molecules in animal cells. The ratio of diadenosine 5′,5‴‐P1,P3‐triphosphate to diadenosine 5′,5‴‐P1,P4‐tetraphosphate (Ap3A/Ap4A) is sensitive to the cellular status and alters when cultured cells undergo differentiation or are treated with interferons. In cells undergoing apoptosis induced by DNA topoisomerase II inhibitor VP16, the concentration of Ap3A decreases significantly while that of Ap4A increases. Here, we have examined the effects of exogenously added Ap3A and Ap4A on apoptosis and morphological differentiation. Penetration of ApnA into cells was achieved by cold shock. Ap4A at 10 μM induced programmed cell death in human HL60, U937 and Jurkat cells and mouse VMRO cells and this effect appeared to require Ap4A breakdown as hydrolysis‐resistant analogues of Ap4A were inactive. On its own, Ap3A induced neither apoptosis nor cell differentiation but did display strong synergism with the protein kinase C activators 12‐deoxyphorbol‐13‐O‐phenylacetate and 12‐deoxyphorbol‐13‐O‐phenylacetate‐20‐acetate in inducing differentiation of HL60 cells. We propose that Ap4A and Ap3A are physiological antagonists in determination of the cellular status: Ap4A induces apoptosis whereas Ap3A is a co‐inductor of differentiation. In both cases, the mechanism of signal transduction remains unknown.
Degradation of an alkaloid pheromone from the pale‐brown chafer, Phyllopertha diversa (Coleoptera: Scarabaeidae), by an insect olfactory cytochrome P450
Authors: Wojtasek Hubert , Leal Walter S
Published: July 2002

The pale‐brown chafer, Phyllopertha diversa, utilizes an unusual alkaloid, 1,3‐dimethyl‐2,4‐(1H,3H)‐quinazolinedione, as its sex pheromone. This compound is rapidly degraded in vitro by the antennal protein extracts from this scarab beetle. Demethylation at the N‐1 position and hydroxylation of the aromatic ring have been identified as the major catabolic pathways. The enzyme responsible for the pheromone degradation is membrane‐bound, requires NAD(P)H for activity and is sensitive to cytochrome P450 inhibitors, such as proadifen and metyrapone. The ability to metabolize this unusual pheromone was not detected in 12 species tested, indicating that the P450 system, specific to male P. diversa antennae, has evolved as a mechanism for olfactory signal inactivation.
Two types of arrestins expressed in medaka rod photoreceptors
Authors: Imanishi Yoshikazu , Hisatomi Osamu , Tokunaga Fumio
Published: July 2002

Similar to visual arrestins of other vertebrates, two subtypes of medaka visual arrestins, KfhArr‐R1 and KfhArr‐C, are selectively expressed in rods and cones, respectively [Hisatomi et al. (1997) FEBS Lett. 411, 12–18]. We isolated a cDNA encoding the third arrestin, KfhArr‐R2, from a medaka retinal cDNA library. Phylogenetic analysis of arrestin sequences suggests that KfhArr‐R2 is classified into the rod arrestin subtype. In situ hybridization indicated that KfhArr‐R2 mRNA is localized in most of the rod photoreceptors, suggesting that both KfhArr‐R1 and ‐R2 are co‐expressed in rods. Antisera against KfhArr‐R2 recognized outer segments, but anti‐KfhArr‐R1 antisera reacted with cell bodies and synaptic termini in light‐adapted rods. It seems likely that KfhArr‐R1 and ‐R2 play different roles in rod photoreceptors.
Prooxidant toxicity of polyphenolic antioxidants to HL‐60 cells: description of quantitative structure‐activity relationships
Authors: Sergedien≐ Egl≐ , Jönsson Kerstin , Szymusiak Henryk , Tyrakowska Bozena , Rietjens Ivonne M.C.M. , Č≐nas Narimantas
Published: July 2002

Polyphenolic antioxidants exhibited a dose‐dependent toxicity against human promyelocytic leukemia cells (HL‐60). Their action was accompanied by malondialdehyde formation, and was partly prevented by desferrioxamine and the antioxidant N,N′‐diphenyl‐p‐phenylene diamine. This points to a prooxidant character of their cytotoxicity. A quantitative structure‐activity relationship (QSAR) has been obtained to describe the cytotoxicity of 13 polyphenolic antioxidants belonging to three different groups (flavonoids, derivatives of gallic and caffeic acid): log cL50 (μM)=(2.7829±0.2339)+(1.2734±0.4715) E
p/2 (V)−(0.3438±0.0582) log P (r
2=0.8129), where cL50 represents the concentration for 50% cell survival, E
p/2 represents the voltammetric midpoint potential, and P represents the octanol/water partition coefficient. Analogous QSARs were obtained using enthalpies of single‐electron oxidation of these compounds, obtained by quantum‐mechanical calculations. These findings clearly point to two important characteristics determining polyphenol cytotoxicity, namely their ease of oxidation and their lipophilicity.
One of the origins of plasma membrane phosphatidylserine in plant cells is a local synthesis by a serine exchange activity
Authors: Vincent Patrick , Maneta-Peyret Lilly , Sturbois-Balcerzak Bénédicte , Duvert Michel , Cassagne Claude , Moreau Patrick
Published: July 2002

In plant cells, as in animal cells, the endoplasmic reticulum (ER) is considered to be the major site of phospholipid synthesis, and it has been shown that phosphatidylserine (PS) reaches the plasma membrane via the vesicular ER‐Golgi‐plasma membrane pathway in leek cells. However, it has never been determined whether the plasma membrane of leek cells is able to synthesize PS. We have analyzed the distribution of PS synthesizing enzymes along the vesicular pathway. In ER, Golgi and plasma membrane fractions isolated from leek cells, we have measured the activity of the two biosynthetic pathways leading to the synthesis of PS, i.e. serine exchange and CTP cytidylyltransferase plus PS synthase. We have found a high serine exchange activity in the plasma membrane fraction, and then determined that this membrane is able to synthesize both long chain fatty acid‐ and very long chain fatty acid‐containing PS. Therefore, the PS in the plasma membrane of leek cells has two different origins: the intracellular vesicular pathway from the ER and a local synthesis in the plasma membrane.
Expression, purification, and initial structural characterization of YadQ, a bacterial homolog of mammalian ClC chloride channel proteins
Authors: Purdy Michael D. , Wiener Michael C.
Published: July 2002

YadQ of Escherichia coli is a homolog of the mammalian chloride channels of the ClC family. The yadQ gene was cloned as a fusion protein with a hexahistidine tag and tobacco etch virus protease site for the removal of the tag. The protein was expressed in the membrane of E. coli and extracted with decylmaltoside. Purification was achieved by metal affinity chromatography followed by cation exchange. Circular dichroism revealed a high α‐helical content. Size exclusion chromatography suggests that YadQ forms dimers. The similarity in primary, secondary, and quaternary structure and the ability to recombinantly express YadQ in the cell membrane make the protein a good candidate for the structural study of ClC chloride channels.
Ultrasonographic detection of single umbilical artery: a simple marker of fetal anomaly
Authors: Şener T. , Özalp S. , Hassa H. , Zeytinoglu S. , Başaran N. , Durak B.
Published: July 2002

Objective: To detect associated anomalies, karyotypes and perinatal prognosis of fetuses with single umbilical artery. Method: Fifteen fetuses who have single umbilical artery were evaluated in the obstetrical ultrasonography and medical genetics departments of Osmangazi University. Results: Fifteen fetuses with single umbilical artery were detected during antenatal ultrasonographic examinations. Associated sonographic abnormalities include oligohydramnios (two), intrauterine growth retardation (one), renal agenesis (one), fetal ascites (one), diaphragmatic hernia (one), hydrocephalus (two), and meningomyelocele (one). Complications related to the pregnancy were pre‐eclampsia in one case and abruptio placenta in another. Karyotype analysis was available in 11 cases and the only cytogenetic abnormality detected was trisomy 18 in one case. Two cases with hydrocephalus and single umbilical artery were delivered by cesarean section at 34 and 38 weeks, but both died (on the first and fifth days after birth). Five pregnancies were terminated because of intrauterine death (one), severe pre‐eclampsia (one), cytogenetic abnormality (one), and multiple congenital anomalies associated with single umbilical artery (two) at 36, 27, 22, 26 and 29 weeks, respectively. Eight of the neonates who had no additional congenital or cytogenetic abnormality were completely normal at birth and during the neonatal period. Diagnoses were confirmed pathologically in all cases. Conclusion: Scanning the umbilical cord should be one of the essential parts of ultrasonographic examination. When single umbilical artery is detected, a detailed ultrasonographic examination is necessary to rule out associated abnormalities. We advise fetal karyotyping even when no additional pathology can be detected on ultrasonographic examination.
The initiation and propagation of the fertilization wave in sea urchin eggs
Authors: McDougall Alex , Shearer Joanne , Whitaker Michael
Published: July 2002

Calcium waves sweep across most eggs of the deuterostome lineage at fertilization. The precise timing of the initiation and propagation of a fertilization calcium wave has been best studied in sea urchin embryos, since the rapid depolarization caused by sperm egg fusion can be detected as a calcium influx using confocal imaging of calcium indicator dyes. The time between sperm egg fusion and the first sign of the calcium increase that constitutes the calcium wave is comparable to the time it takes for the wave to sweep across the egg, once initiated. The latency and rise time of the calcium response is sensitive to inhibitors of the InsP3 signalling pathway, as reported previously. Using calcium green dextran and confocal microscopy, we confirm that the propagation time of the calcium wave is lengthened and that initiation of the calcium wave involves activation of calcium release at hot spots that may represent clusters of calcium release channels, as has been seen in other cell types.
Viability of ischemia/reperfused muscles in rat: a new evaluation method by RNA degradation
Authors: Akahane M. , Ono H. , Ohgushi H. , Tamai S.
Published: July 2002

The rat's skeletal muscle viability was evaluated using the muscle viability index (MVI) which reflects the mRNA degradation. To evaluate ischemic injury of the muscle, 24 hind limbs of Fischer rats (three subgroups of eight rats each) were preserved at normothermia for 1, 3 and 6 h and then tibialis anterior muscle was harvested. To investigate ischemia/reperfusion injury, another 48 limbs were transplanted to recipient Fischer rats after the ischemia at normothermia for 1, 3 and 6 h, respectively. The transplanted muscles were harvested on day 3 and day 7 after transplantation. Eight fresh muscles were also harvested and used as control. Total RNA isolated from each muscle was fractionated by electrophoresis and hybridized with 32P‐labelled cDNA of GAPDH, and the radioactivity of intact and degraded GAPDH mRNA was measured. MVI was calculated as follows, MVI = {X/(X + Y)} × 100, where X and Y represent the radioactivities corresponding to intact GAPDH and degraded GAPDH mRNA band, respectively.

In 1‐h ischemia group, the MVI indices of both ischemic insult and ischemia/reperfusion group were comparable to control. In the 3‐h ischemia group, the index of ischemia/reperfused group was comparable to control although the index of ischemic insult group was significantly lower than control. However, in the 6‐h ischemia group, both indices of ischemic insult and ischemia/ reperfusion group were significantly lower than control. These results show that the muscle damage was detected in ischemia at normothermia even after 3 h. However, this damage was overcome by reperfusion. There was no recovery from damage in muscles that had been preserved for more than 6 h which had resulted in irreversible degeneration. Therefore, in clinical muscle transplantation, one has to transplant the muscle at least within 3‐h ischemia.
Pamidronate decreases tumor‐induced osteoclastogenesis in osteopetrotic mice
Authors: Clohisy Denis R. , O'Keefe Patrick F. , Ramnaraine Margaret L.
Published: July 2002

Recent studies indicate that the bisphosphonate pamidronate reduces skeletal complications caused by tumor osteolysis. In this investigation, the cellular mechanism through which pamidronate affects tumor‐induced osteoclastogenesis is studied in osteopetrotic mice. A unique animal model is employed which studies the effect of pamidronate on a tumor (2472 sarcoma) which induces osteoclastogenesis in osteoclast‐deficient mice (oplop). This model provides opportunity to specifically study effects on osteoclast formation and findings suggest that pamidronate decreases the number of osteoclasts at sites of 2472 tumor by decreasing the number of osteoclast precursor cells at the level of myeloid precursors. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Novel 29 kDa heparin‐binding lectin from human foetal brain
Authors: Basu S. , Gupta G. , Chowdhury G. , Mahajan R.G.
Published: July 2002

Heparin inhibitable lectins are physiologically important because of their interactions with extracellular matrix and with other cell surface glycoconjugates. However, due to the unstable nature of these animal lectins, it becomes necessary to purify them in the shortest possible time. In the present study, a chromatographic procedure was developed to separate heparin inhibitable lectin activity.Lectin activities from human foetal brain were separated on a Q‐Sepharose column employing different equilibration conditions. When proteins were loaded on to a phosphate‐buffered saline (PBS) equilibrated column and eluted with salt gradient, only one lectin peak was obtained. However, when proteins were loaded on to a hypotonic equilibrated column and eluted with a salt gradient, four lectin peaks were obtained.The lectin peak obtained from the PBS equilibrated column was characterized as heparin inhibitable lectin. On SDS–PAGE analysis, it gave a single band of 29 kDa. For optimum lectin activity, a pH of around 7.0 was required. Lectin activity was stimulated by Mn++; amino acid composition was different from other known lectins. The lectin was particularly rich in acidic amino acids.Regional distribution of 29 kDa lectin in different foetal brain regions gave the highest content in the cerebral cortex, showing a caudoroastral distribution. Determination of the subcellular distribution of the lectin in the foetal cerebral cortex gave the highest value with a mitochondrial fraction.
Developmentally regulated release of intraretinal neurotrophic factors in vitro
Authors: Arv‐Pires R. , Nakatani M. , Rehen S.K. , Linden R.
Published: July 2002

The effects of conditioned media either from aggregates or from explants of embryonic chick retinae and of recombinant neurotrophins were tested upon the survival in vitro of ganglion cells in dissociated cell cultures from the retina of newborn rats. Ganglion cells were identified by the detection of retrogradely transported horseradish peroxidase injected bilaterally into the superior colliculus. Conditioned media increased significantly the survival of ganglion cells after 2 days in culture, at a wide range of plating densities, and had no effect upon adhesion of rat retinal cells. Media conditioned by cell ensembles from chick retinae from embryonic day 8 (E8) to E16 had neurotrophic effects. Release of neurotrophic activity peaked at E10‐E12, irrespective of the numbers of cells or total concentration of protein in the conditioned media. The active molecules were non‐dialyzable and were released either in the presence or in the absence of fetal calf serum. The neurotrophic activity was abolished by trypsinization, and recovered by salting‐out with 25–75% ammonium sulfate. NT‐4, BDNF and, to a lesser extent, NT‐3, increased the survival of ganglion cells in our assay, while NGF had no effect. The data show that chick retinal cells release soluble trophic proteins according to a developmentally regulated pattern. These neurotrophic factors may be involved in local competitive interactions that help control naturally occurring neuron death among ganglion cells of the vertebrate retina.
Developmental regulation and effect of early undernutrition on phosphorylation of rat cortical synaptic membrane proteins
Authors: Singh Tryambak Deo , Shankar Raj
Published: July 2002

Undernutrition during early postnatal life was employed in rats by restricting the feeding time. The synaptic membrane fraction from cerebral cortex of normal and undernourished rats of various ages was prepared and endogenous protein phosphorylation studied. Many of the synaptic membrane proteins were found to be phosphorylated in an age‐dependent manner. Early undernutrition affects the phosphorylation of various proteins in a complex way; most affected were 48‐, 52‐, 61‐ and 74‐kDa proteins. These proteins were found to have phosphorylations mainly at tyrosine residues. This finding indicates that tyrosine phosphorylations may be affected most by early undernutrition. Adequate nutrition after early undernutrition removes most of the effects of undernutrition on synaptic protein phosphorylation. To address the question of how undernutrition may affect protein phosphorylation, we studied the lipid content of synaptic membrane fraction as it can affect membrane properties, including the fluidity. We found that undernutrition affects phosphorylation of most of the synaptic membrane proteins in the same manner in which it affects the cholesterol–phospholipid ratio of synaptic membrane and, hence, the fluidity of the membrane. This indicates that lipid biosynthesis is one of the ways by which undernutrition can affect synaptic membrane protein phosphorylation.
Role of acetylcholinesterase in the development of axon tracts within the embryonic vertebrate brain
Authors: Anderson R.B. , Key B.
Published: July 2002

In the developing vertebrate brain, acetylcholinesterase (AChE) expression coincides temporally with axon tract formation. Although AChE promotes neurite outgrowth in vitro, the role of this molecule in the development of axon tracts in vivo is unknown. To address this question, we examined the effects of the AChE inhibitor, BW284C51, on the formation of the early scaffold of axon tracts in the embryonic Xenopus brain. In exposed Xenopus brain preparations, axons elongate and establish a normal topography of axon tracts. However, when brains were exposed to BW284C51, the thickness of the major longitudinal axon tract, the tract of the post‐optic commissure decreased in a dose‐dependent manner. When BW284C51 was removed from the culture media axon tract development returned to normal within 5 h. These findings provide the first evidence for a non‐classical role of AChE in the initial formation of axon tracts within the developing vertebrate brain.
Familial factors influencing the consumption of anxiolytics and hypnotics by children and adolescents
Authors: Pélissolo A. , Gourion D. , Notides C. , Bouvard M. , Lépine J.P. , Mouren-Siméoni M.C.
Published: July 2002

Many hypotheses have been made to explain the high rate of benzodiazepine consumption in France, including a general cultural and/or familial tendency to use certain types of psychotropic drugs. This study explored the association between lifetime medication use by parents and their children. Two hundred and twenty-one young patients (158 boys and 63 girls) consulting at a child and adolescent psychiatry department, six to 16 years of age (mean = 9.7 years), were screened for lifetime use of psychotropic drugs using a structured interview. Parents were asked about their own consumption, as well as their children’s. Lifetime consumption rates (at least once) were 22.2% in boys and 20.6% in girls, and 19.6% in children less than 11 years old. Higher rates were found in patients with emotional disorders (anxiety disorders and depression). In parents, 45.1% of mothers and 24.1% of fathers reported using medications at least once. A significant association was found between child and parental medication use: 34.1% of children had positive lifetime consumption when their mothers also used medications at least once versus only 13.6% in other children (odds ratio = 3.31 [1.68–6.50]; P = 0.001). The most significant association was found between medication use by girls and their mothers (odds ratio = 12.1 [2.38–61.5];P = 0.003). These data point to the existence of a family pattern of psychotropic drug consumption, especially in females.
The ICD-10 and DSM-IV diagnostic criteria and the prevalence of schizophrenia
Authors: Lindström E , Widerlöv B , von Knorring L
Published: July 2002

In the present study, all patients who met the diagnostic criteria for a long-term functional psychosis (LFP) were identified within a defined uptake area in the northern part of the county of Uppsala, Sweden. LFP includes patients 1) with productive psychotic symptomatology, not caused by organic disease, for 1 week or more, at least once during the course of the illness; 2) having been affected by a psychosis for a continuous period of at least 6 months on the same occasion; 3) having shown psychotic features or residual symptoms during the index year; and 4) older than 18 years of age. Primarily, all diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R. The prevalence of schizophrenia was 4.2 per 1,000 inhabitants. The prevalence of schizoaffective disorder was 0.7 per 1,000 inhabitants and for delusional disorder, 0.1 per 1,000 inhabitants. When the patients were rediagnosed according to DSM-III, DSM-IV and International Statistical Classification of Disease (ICD)-10, it was found that the prevalence of schizophrenia, schizoaffective disorder and delusional disorder was somewhat lower according to the DSM-III criteria, while the same number of patients fulfilled the criteria according to DSM-IV. If ICD-10 was used, it resulted in a broader concept of schizophrenia and a somewhat more narrow concept of schizoaffective disorder. Thus, the introduction of the new parallel diagnostic systems, ICD-10 and DSM-IV, will result in different, but comparable, prevalence estimates concerning schizophrenia, schizoaffective disorder and delusional disorder.
Collective Protest in Post-Communist Poland, 1989–1993: a Research Report
Authors: Ekiert Grzegorz , Kubik Jan
Published: July 2002

The authors' original research project provides new evidence that collective protest constituted a significant part of Polish political life during the first years of post-communist transformations. The paper demonstrates that the magnitude of protest increased from 1989 to 1993. Major features of protest politics are described: participants' social backgrounds, organizations sponsoring or leading protest, repertoire of contention, demands, targets of protest actions, and finally state responses and protest effectiveness. The main conclusion is that although protest was intense and politically significant, it was at the same time highly institutionalized. The concept of institutionalized contentiousness captures this phenomenon.
Social Security reform
Authors: Elder Erick , Holland Larry
Published: July 2002

Several proposals have been developed to reform the Social Security System to ensure that it is fully funded. The investment of a portion of Social Security funds in equities has often been proposed as a means to avoid increasing payroll taxes. This paper develops a general equilibrium model to demonstrate that investing Social Security funds in equities will decrease the return on equities and increase interest rates on bonds, which also leads to an increase in general income taxes. Thus, investing Social Security funds in equities simply shifts a potential increase in payroll taxes to an increase in income taxes. © 2000 Elsevier Science Inc. All rights reserved.