bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron entry route in horse spleen apoferritin
Authors: Desideri A. , Stefanini S. , Polizio F. , Petruzzelli R. , Chiancone E.
Published: July 2002

Apoferritin has been selectively labeled with a maleimide nitroxide derivative at Cys‐126, located in the hydrophilic 3‐fold channels. Titration of this derivative with Fe(II), which gives rise to the initial Fe(III)‐apoferritin complex, produces, at low metal‐to‐protein ratios, a decrease of the intensity of the label EPR signal due to the occurrence of a magnetic dipolar interaction. A label‐metal distance ranging between 8–12 Å can be estimated from titrations performed with VO(IV), which is known to bind in the 3‐fold channels, and likewise produces a decrease in the label EPR signal. The present findings indicate that iron binds in the hydrophilic channels in its higher oxidation slate and that these channels represent the metal entry route at least at low metal‐to‐protein ratios.
Down‐regulation of a kinase defective PKC‐α
Authors: Pears Cathy , Parker Peter J.
Published: July 2002

A kinase defective mutant of PKC‐α down‐regulates in response to phorboI esters as effectively as the wild‐type protein when introduced into COS‐1 cells. This demonstrates that intramolecular autophosphorylation is not a prerequisite for down‐regulation.
Autoregulatory control of actin synthesis in cultured rat hepatocytes
Authors: Reuner Karl H. , Schlegel Kurt , Just Ingo , Aktories Klaus , Katz Norbert
Published: July 2002

ADP‐ribosylation of actin by Clostridium botulinum C2 toxin resulted in a depolymerization of filamentous F‐actin and an increase of monomeric G‐actin in cultured hepatocytes, Simultaneously the de novo synthesis of actin was largely reduced, while the synthesis of albumin and of other proteins was not significantly impaired. The specific decrease of actin mRNA to 30% of the control indicates a down‐regulation of actin synthesis at a pretranslational level. On the other hand, treatment with the mycotoxin phalloidin resulted in an increase of F‐actin and a decrease of monomeric G‐actin. Under this condition the de novo synthesis of actin was specifically enhanced and the level of actin mRNA was increased to 600% of the control. The data suggest an autoregulatory control of the actin synthesis.
Growth factor‐stimulated trans plasma membrane electron transport in HL‐60 cells
Authors: Navas Placido , Alcain Francisco J. , Burón Isabel , Rodríquez-Aguilera Juan-Carlos , Villalba Jose M. , Morré Dorothy M. , Morré D.James
Published: July 2002

Electron flow across the plasma membrane of living cells and its rapid modulation by growth factors has been measured continuously through a simple assay procedure whereby the transported electrons are captured by ascorbate free radical to slow the rate of chemical oxidation of ascorbate. The assay provides a direct demonstration of electron transport to an external electron acceptor that is both physiological and impermeant. The reduction of external ascorbate free radical is stimulated by the growth factors, EGF and transform, and is inhibited by wheat germn agglutinin. The results demonstrate, under physiological conditions, the operation of a growth factor‐ and lecitin‐responsive electron transport system at the cell surface using a cultured human cell line.
Evidence for multiple genes coding for the isozymes of hexokinase in the highly glycolytic AS‐30D rat hepatoma
Authors: Wigley W.Christian , Nakashima Richard A.
Published: July 2002

We have compared Southern blots of rat hepatoma DNA probed with Types I, II and III hexokinase cDNAs isolated from normal rat tissues. Hybridization patterns show several fragments recognized by both the Type I and II clones while no resemblance is observed between the Type III probe and the other two isozymes. It therefore appears that the Type I‐like and Type‐II‐like hepatoma isozymes are coded for by similar yet separate genes, while a dissimilar third gene codes for the Type III‐like isozyme. In addition, a loss of heterozygosity was detected at the Type III locus in the AS‐30D hepatoma when compared to normal tissues. As only the Type II‐like isozyme is highly expressed in highly glycolytic tumors. these data have implications for differential gene regulation between the turmor isozymes.
Highly conserved hexamer, octamer and nonamer motifs are positive cis‐regulatory elements of the wheat histone H3 gene
Authors: Nakayama Takuya , Sakamoto Ayako , Yang Ping , Minami Maki , Fujimoto Yoshinobu , Ito Takuya , Iwabuchi Masaki
Published: July 2002

Base substitution mutations were introduced into the promoter region of the wheat histone H3 gene and promoter activity was assayed in stably transformed sunflower calli or in wheat protoplasts transfected transiently. At least four positive regulatory elements, a hexamer motif (ACGTCA). two octamer(‐like) motifs of a direct (CcCGGATC) and a reverse (aATCCGCG) form, and a nonamer motif (CATCCAACG) were identified within the ‐185 region of the H3 promoter. Analyses of the type I element (CCCC) consisting of the hexamer and reverse‐oriented octamer motifs, and which is conserved in other plant histone genes as well, predicted the presence of an octamer‐binding protein(s).
Cycloheximide inhibits cellular, but not SV40, DNA replication
Authors: Schulte Dorothea , Knippers Rolf , Dreier Torsten , Probst Gudrun , Probst Hans
Published: July 2002

We have prepared extracts from cycloheximide‐treated cells for the study of simian‐virus‐40 (SV40)‐DNA replication in vitro. When supplemented with the viral initiator protein (large T antigen), these extracts fully supported SV40‐DNA replication. We also determined that SV40‐DNA replication in vivo is much more resistant to cycloheximide than cellular DNA replication. SV40 encodes its own initiator protein, T antigen, which also functions as a DNA helicase, but depends on cellular functions for all additional replication reactions. Therefore, it appears to be quite likely that cycloheximide affects cellular DNA replication by blocking the synthesis of (a) cellular function(s) that is(are) performed by T antigen in SV40‐DNA replication. Indeed, DNA fiber autoradiography and alkaline sucrose gradient centrifugation of pulse‐labeled cellular DNA showed that cycloheximide treatment almost completely suppressed replicon initiation and reduced the rate of replication fork movement to about one third of the control.
The UDP‐N‐acetylglucosamine 1‐carboxyvinyl‐transferase of Enterobacter cloacae Molecular cloning, sequencing of the gene and overexpression of the enzyme
Authors: Wanke Christoph , Falchetto Rocco , Amrhein Nikolaus
Published: July 2002

The UDP‐N‐acetylglucosamine 1‐carboyyvinyltransferase (enol‐pyruvyltransferase, EC 2.5,1.7) which catalyses the first committed step in the biosynthesis of the bacterial cell‐wall peptidoglycan was purified to near homogeneity from Enterobacter cloacae and the NH2‐terminal amino‐acid sequence determined. Using the polymerase chain reaction a 53‐bp DNA fragment was synthesized; this fragment encodes the NH2‐terminal sequence of the enzyme. A clone was then isolated which contained an open reading frame of 1257 bp coding for a protein of 419 amino acids. This protein was overexpressed 100‐fold in transformed Escherichia coli cells and shown to possess the enolpyruvyltransferase activity. The overall amino‐acid sequence of the enolpyruvyltransferase is significantly similar to that of the 5‐enolpyruvylshikimate 3‐phosphate synthase, the only other enzyme known to catalyse the transfer of the enolpyruvate moiety of phosphoenolpyruvate to a substrate.
Effects of thionins on β‐glucuronidase in vitro and in plant protoplasts
Authors: Diaz Isabel , Carmona María Jose , García-Olmedo Francisco
Published: July 2002

Thionins cause the irreversible inactivation of β‐glucuronidase (GUS) in vitro in a dose‐ and time‐dependent manner. The enzyme is also sensitive to externally added thionins when expressed in the cytoplasmic compartment of tobacco protoplasts transformed with the Gus gene under the 35S promoter of the cauliflower mosaic virus. In protoplasts transformed with the Gus gene fused to a signal peptide, where GUS is translocated into the lumen of the endoplasmic reticulum, the activity is significantly increased both by externally‐added and by transiently‐expressed thionin, suggesting that it interferes with GUS secretion.
Phosphorylation of the phosphatase modulator subunit (inhibitor‐2) by casein kinase‐1 Identification of the phosphorylation sites
Authors: Agostinis Patrizia , Marin Oriano , James Peter , Hendrix Peter , Merlevede Wilfried , Vandenheede Jackie R. , Pinna Lorenzo A.
Published: July 2002

The isolated modulator subunit of the inactive protein phosphatase‐1 is phosphorylated in vitro by casein kinase‐1 at two different site Ser‐86 and Ser‐174. The Ser‐86 site is a common target for casein kinase‐1 and casein kinase‐2, but is preferentially phosphorylated by the former enzyme. The Ser‐174 site seems to be specific for casein kinase‐1, and is phosphorylated at a slower rate. These results give a new insight into the in vitro phosphorylation pattern of the modulator subunit of the phosphatase and provides additional data on the specificity of casein kinase‐1.
Tyrosine‐89 is important for enzymatic activity of S. cerevisiae inorganic pyrophosphatase
Authors: Raznikov Andrey V. , Sklyankina Vera A. , Avaeva Svetlana M.
Published: July 2002

7‐Chloro‐4‐nitro‐benzofurazan selectively modifies one PPase Tyr residue per subunit and lowers the enzyme activity. Hydrolysis of the modified protein by trypsin and then by chymotrypsin produces the 82–89 peptide which possesses modified Tyr‐89. Substrate analog (CaPPi) and the product of the enzyme reaction, MgP1, protect the enzyme against inactivation. Ions of metal‐activators (Mg2+, Zn2+) exert no influence on the inactivation rate. On the contrary, the Ca2+‐inhibitor of the enzyme accelerates the reaction by binding to the high‐affinity site, and effectively decreases it when Ca2+ binds to both sites. Mg2+ competes with Ca2+ for one binding site, which is the low affinity site for Mg2+ and the high‐affinity site for Ca2+. The Ca2+ saturation of the high‐affinity site decreases the pK
2 of Tyr‐89, probably due to direct coordination between Tyr and Ca2+. The observed properties of Tyr‐89 modification enable us to propose that Tyr‐89 serves as a proton donor for phosphate releasing during enzymatic hydrolysis of pyrophosphate. The Ca2+ inhibitory effect on the enzyme activity may be due to the existence of a Tyr‐89 bond in the Cn2+ pyrophosphatase complex.
Decay of Superoxide catalyzed by ferritin
Authors: Bolann Bjørn J. , Ulvik Rune J.
Published: July 2002

Ferritin iron can be reduced by O.−
2, released, and form a Fe(II)‐chelator complex. However, the thermodynamic influence of the chelator may disturb the reaction balance. We therefore excluded the chelator and measured instead the effect of ferritin on the decay of O.−
2, monitored by direct spectrophotometry at pH 9.5. Ferritin, but not apoferritin, accelerated the decay of O−
2. Ferritin iron was apparently the responsible agent. The effect of ferritin was maintained after several bursts of O.−
2, and the ratio degraded O.−
2/released Fe(II) greatly exceeded one, consistent with a catalytic reaction.
NMR and circular dichroism studies of the lantibiotic nisin in non‐aqueous environments
Authors: van den Hooven Henno W. , Fogolari Federico , Rollema Harry S. , Konings Ruud N.H. , Hilbers Cornelis W. , van de Ven Frank J.M.
Published: July 2002

The lantibiotic, nisin, which is known to interact with membranes of certain Gram‐positive bacteria, was studied in three model systems which mimic a membrane‐like environment, i.e. a mixture of trifluoroethanol and water, or micelles of sodium dodecyl sulfate or dodecylphosphocholine. The 1H NMR spectra of nisin in the non‐aqueous environments, at 40°C and pH 3.5, have been assigned completely. The CD and NMR results indicate that the conformation of nisin in the three non‐aqueous environments differs from that in aqueous solution, and that the conformation in the two micellar systems is similar. The major conformational changes, relative to nisin in aqueous solution, occur in the N‐terminus.
pp59fyn and pp62c‐yes are enriched in SH‐SY5Y neuroblastoma growth cones but do not associate to the 38 kDa protein which complexes with pp60c src and pp60c‐srcN
Authors: Meyerson Gabrielle , Påhlman Sven
Published: July 2002

The tyrosine‐specific kinases pp60c‐src and pp60c‐srcN (pp60src) are slightly enriched and activated in growth cones isolated from neuronally differentiating SH‐SY5Y neuroblastoma cells. In the growth cones the two src isoforms are associated with a 38 kDa protein. In this report, we have compared the subcellular distribution of pp59fyn and pp62c‐yes with that of pp60src in differentiating SH‐SY5Y cells. Like pp60src, the other two tyrosine kinases were slightly enriched and activated in the growth cones as compared to the levels in the cell bodies. The kinase activites were 3‐ to 4‐times higher in growth cones than in cell bodies. However, only pp60src formed a complex with the 38 kDa protein while immunoprecipitation of pp59fyn brought down an additional protein of 90 kDa. This may suggest that these related tyrosine kinases have different substrates and in part mediate different cellular responses in the growth cones of differentiating SH‐SY5Y cells.
Inhibition of passive sensitization of human peripheral basophils by synthetic human immunoglobulin E peptide fragments
Authors: Nio Noriki , Seguro Katsuya , Ariyoshi Yasuo , Imano Kiyomi , Yakuo Ikuhisa , Kita Atsuko , Nakamura Hideo
Published: July 2002

To delineate the binding site in the human immunoglobulin E (IgE) molecule to the Fcϵ receptor on basophils and mast cells, we chemically synthesized a total of 71 peptide fragments within the sequence Ser300‐Lys547 in the human IgE molecule. The synthetic peptides were tested for their capacity to inhibit passive sensitization of human peripheral basophils with atopic patient's serum containing the specific IgE against dust mites in vitro. It was found that a peptide fragment, Pro345‐Ile356, potently inhibited the passive sensitization. To clarify the minimal active core, various analogues, such as shortened, substituted (by Gly or Ala residue), omission and retro‐sequence peptides, were synthesized and assayed. The results suggested that the sequence Pro345‐Lys352 in the human IgE molecule would be an IgE binding site, and that a synthetic octapeptide, Pro345‐Phe‐Asp‐Leu‐Phe‐Ile‐Arg‐Lys352, inhibited the passive sensitization, probably by occupying the Fcϵ receptor sites on the cells.
Sequence, overproduction and crystallization of aspartyl‐tRNA synthetase from Thermus thermophilus
Authors: Poterszman Arnaud , Plateau Pierre , Moras Dino , Blanquef Sylvain , Mazauric Marie-Hélène , Kreutzer Roland , Kern Daniel
Published: July 2002

The genes of aspartyl‐tRNA synthetase (AspRS) from two Thermus thermophilus strains VK.‐1 and HB8, have been cloned and sequenced. Their nucleotidic sequences code for the same protein which displays the three characteristic motifs of class II aminoacyl‐tRNA synthetases. This enzyme shows 50% identity with Escherichia coli AspRS, over the totality of the chain (580 amino acids). A comparison with the eukaryotic yeast cytoplasmic AspRS indicates the presence in the prokaryotic AspRS of an extra domain between motifs 2 and 3 much larger than in the eukaryotic ones. When its gene is under the control of the tac promoter of the expression vector pKK223‐3, the protein is efficiently overexpressed as a thermostable protein in E. coli. It can be further purified to homogeneity using a heat treatment followed by a single anion exchange chromatography. Single crystals of the pure protein, diffracting at least to 2.2 Å resolution (space group P212121, a = 61.4 Å, b = 156.1 Å, c = 177.3 Å) are routinely obtained. The same crystals have previously been described as crystals of threonyl‐tRNA synthetase [1].
ATP‐driven Na+ transport and Na+‐dependent ATP synthesis in Escherichia coli grown at low \ΔgmH+
Authors: Avetisyan A.V. , Bogachev A.V. , Murtasina R.A. , Skulachev V.P.
Published: July 2002

In inverted subcellular vesicles of Escherichia coli grown at high \ΔgmH+ (neutral pH, no protonophorous uncoupler), ATP‐driven Na+ transport and oxidative phosphorylation are completely inhibited by the protonophore CCCP. If E coli was grown at low \ΔgmH+, i.e. at high pH or in the presence of uncoupler, some oxidative phosphorylation was observed in the vesicles even in CCCP‐containing medium, and Na+ transport was actually stimulated by CCCP. The CCCP‐resistant transport and phosphorylation were absent from the unc mutant lacking F0F1, ATPase. Both processes proved to be sensitive to (i) the Na+/H+ antiporter monensin, (ii) the Na+ uniporter ETH 157, (iii) the F0 inhibitors DCCD and venturicidin, and (iv) the F1 inhibitor aurovertin. The CCCP‐resistant oxidative phosphorylation was stimulated by Na+ and arrested by oppositely directed ΔpNa. These data are consistent with the assumption that, under appropriate growth conditions, the F0F1‐type ATPase of E. coli becomes competent in transporting Na+ ions.
Tissue specificity of mitochondrial F0F1‐ATPase activity of Lilium longiflorum plant
Authors: Itoh Aya , Sekiya Jiro
Published: July 2002

A large difference was found in the activities of oligomycin‐sensitive mitochondrial F0F1‐ATPase isolated from different tissues of Lilium longiflorum plants. The enzyme activity of F0F1‐ATPase in pollen was the highest, while that in bulbs was the lowest. When ATPases were cross‐reconstituted from F1‐ATPases and F1‐depleted submitochondrial particles (SMP), ATPases reconstituted from F1‐depleted pollen SMP showed the higher activity regardless of the source of F1‐ATPase. Fatty acid compositions of phospholipids in SMP were also different between bulbs and pollen. These suggest that the F0 portion and/or its environment are important for regulation of F0F1‐ATPase activity in L. longiflorum plant.
Thermal unfolding of monomeric Ca(II),Mg(II)‐ATPase from sarcoplasmic reticulum of rabbit skeletal muscle
Authors: Merino Jaime M. , Moller Jesper V. , Gutiérrez-Merino Carlos
Published: July 2002

The thermal unfolding of monomeric and delipidated Ca2+‐ATPase, solubilized in C12E8, can be appropriately described as a non‐two‐state irreversible denaturation, with only one endothermic peak. In the Ca2+ concentration range (0–0.5 mM) which stimulates the ATPase activity of solubilized monomeric ATPase, Ca2+ shifts the critical temperature midpoint of the denaturation process (T
m) from 42 to 50°C without segregation of the endothermic peak into two separate components. Because 20 mM Mg2+ only shifts the T
m from 42 to 44°C, we conclude that the effect of Ca2+ upon the T
m is likely to be due to binding to the high affinity Ca2+ sites in the ATPase. The effect of Ca2+ upon the enthalpy of denaturation is biphasic, suggesting the presence of low affinity Ca2+ sites (K
0.5 in the millimolar range) in monomeric and solubilized ATPase.
Regulatory sequences required for hst‐1 expression in embryonal carcinoma cells
Authors: Koda Toshiaki , Hasan Shahid , Sasaki Akio , Arimura Yutaka , Kakinuma Mitsuaki
Published: July 2002

The hst‐1 gene, which is implicated in mammalian embryonic development and morphological transformation of NIH3T3 cells, is expressed in undifferentiated F9 cells, but not in differentiated F9 and other well‐differentiated cells, such as PYS‐2, NIH3T3 and HeLa cells. An octamer element present in the 3' untranslated region acts as an enhancer. Although Oct3 is down‐regulated when F9 cells are differentiated, transient expression of Oct3 did not enhance the hst‐1 promoter activity in HeLa, NIH3T3 or PYS‐2 cells. Thus, the role of Oct3 on hst‐1 expression remains elusive, and an additional transcription factor which interacts may regulate hst‐1 transcription in association with Oct1, Oct3 or both.
A brain‐specific γ subunit of G protein freed from the corresponding β subunit under non‐denaturing conditions
Authors: Morishita Rika , Kato Kanefusa , Asano Tomiko
Published: July 2002

It has generally been accepted that the β and γ subunits of G proteins are tightly associated and can only be dissociated under denaturing conditions. However, one form of the γ subunit, free of the β subunit, was isolated under non‐denaturing conditions during the purification of βγ complexes from bovine brain. Amino acid sequence analysis revealed that the N‐terminus of this γ subunit was not blocked and its sequence was identical to that of a brain‐specific γ subunit, γ3. Among three forms of γ subunits observed in bovine brain (γ2, γ3 and γ7), γ3 was the only form that was not modified at the N‐terminus. Although the physiological significance of the free form of γ3 is not clear, these results suggest that N‐terminal modification of γ subunits may be important for interaction with β subunits.
The allosteric regulation of pyruvate kinase
Authors: Mattevi Andrea , Bolognesi Martino , Valentini Giovanna
Published: July 2002

Crystallographic and mutagenesis studies have unravelled the general features of the allosteric transition mechanism in pyruvate kinase. The enzyme displays a dramatic conformational change in going from the T‐ to the R‐state. All three domains forming each subunit of the tetrameric enzyme undergo simultaneous and concerted rotations, in such a way that all subunit and domain interfaces are modified. This mechanism is unpreceDAnted since in all tetrameric allosteric enzymes, characterised at atomic resolution, at least one of the domain or subunit interfaces remains unchanged on the T‐ to R‐state transition. The molecular mechanism of allosteric regulation here proposed proviDAs a rationale for the effect of single site mutations observed in the human erythrocyte pyruvate kinase associated with a congenital anaemia.
In isolated human centrosomes, the associated kinases phosphorylate a specific subset of centrosomal proteins
Authors: Keryer Guy , Celati Claude , Klotz Catherine
Published: July 2002

Summary— Several studies have shown that kinases and phosphatases can interact with the centrosome during interphase and mitosis suggesting that centrosomal components might be the targets of these enzymes. The association of the cAMP‐dependent protein kinase type II and the mitotic kinase p34cdc2 with centrosomes from human lymphoblast cells has previously been shown (Keryer et al, 1993, Exp Cell Res 204, 230–240; Bailly et al, 1989, EMBO J 8, 3985–3995). In this paper we demonstrate that isolated centrosomes are able to phosphorylate a few number of centrosomal proteins (Mr 230–220000; 135000 and 50000) and also H1 histone. The phosphorylation of H1‐histone is cell cycle dependent and modulated by phosphatases. The use of kinase and phosphatase inhibitors and the addition of the catalytic subunit of cAMP‐dependent kinase or of cyclinB‐p34cdc2 kinase showed that both kinases phosphorylate the same centrosomal substrates. In addition two centrosomal proteins (Mr 100000 and 37000) were phosphorylated only by p34cdc2 kinase. Although the low amount of centrosomal proteins precluded a full characterization of these substrates we discuss the identity of the major centrosomal phosphoproteins by comparison with proteins known to associate with microtubule‐organizing centres or mitotic spindles. Our results raise also the intriguing possibility that the cAMP‐dependent protein kinase could be regulated by the mitotic kinase at the entry of mitosis.
Type I muscle atrophy caused by microgravity‐induced decrease of myocyte enhancer factor 2C (MEF2C) protein expression
Authors: Yamakuchi Munekazu , Higuchi Itsuro , Masuda Satoko , Ohira Yoshinobu , Kubo Toshikazu , Kato Yutaka , Maruyama Ikuro , Kitajima Isao
Published: July 2002

To investigate the molecular mechanisms of muscle atrophy under microgravity, the paraspinal muscles of rats after 14 days spaceflight and those of ground‐based controls were examined. In the microgravitational environment, expressions of 42 genes changed, and the expressions of heat shock protein 70 and t complex polypeptide 1 increased. In Northern blotting, myocyte‐specific enhancer binding factor 2C (MEF2C) and MEF2C‐related genes including aldolase A and muscle ankyrin decreased. After 9 days ground recovery, expression of MEF2C increased and it was located mainly on the satellite cells in the muscle regeneration state. MEF2C could be a key transcriptional factor for skeletal muscle atrophy and regeneration under microgravity.
Transcriptome meets metabolome: hierarchical and metabolic regulation of the glycolytic pathway
Authors: ter Kuile Benno H , Westerhoff Hans V
Published: July 2002

The fact that information flows from DNA to RNA to protein to function suggests that regulation is ‘hierarchical’, i.e. dominated by regulation of gene expression. In the case of dominant regulation at the metabolic level, however, there is no quantitative relationship between mRNA levels and function. We here develop a method to quantitate the relative contributions of metabolic and hierarchical regulation. Applying this method to the glycolytic flux in three species of parasitic protists, we conclude that it is rarely regulated by gene expression alone. This casts strong doubts on whether transcriptome and proteome analysis suffices to assess biological function.
Aspirin inhibits expression of the interleukin‐1β‐inducible group II phospholipase A2
Authors: Vervoordeldonk Margriet J.B.M. , Pineda Torra Inés M. , Aarsman Anton J. , van den Bosch Henk
Published: July 2002

Nonsteroidal anti‐inflammatory drugs (NSAIDs) clearly inhibit the synthesis and release of prostaglandins. However, these actions are not sufficient to explain all the anti‐inflammatory effects of these drugs. Recently, it has been shown that aspirin and sodium salicylate inhibit the activation of the transcription factor NF‐κB. Group II phospholipase A2 (sPLA2) is expressed in rat glomerular mesangial cells upon exposure to the inflammatory cytokine interleukin‐1β (IL‐1β) and this induction is attenuated by the NF‐κB inhibitor pyrrolidine dithiocarbamate (PDTC). We now report that aspirin inhibits the IL‐1β‐induced sPLA2 activity in rat mesangial cells in a dose‐dependent manner. The IC50 value of aspirin for sPLA2 inhibition was 6.5 mM. This decrease in sPLA2 activity was not due to direct inhibition of enzymatic activity but rather to the fact that aspirin inhibits the expression of IL‐1β‐induced sPLA2 protein and mRNA. Furthermore, by electrophoretic mobility shift analysis we demonstrate reduced DNA binding of the nuclear factor κB, an essential component of the IL‐1β‐dependent upregulation of sPLA2 gene transcription, after treatment of the cells with aspirin. The study described in this report indicates that the inhibition of sPLA2 expression as induced by pro‐inflammatory cytokines potentially represents an additional mechanism of action for aspirin.
Demonstration of dimer formation of the cytoplasmic domain of a transmembrane osmosensor protein, EnvZ, of Escherichia coli using Ni‐histidine tag affinity chromatography
Authors: Hidaka Yuji , Park Heiyoung , Inouye Masayori
Published: July 2002

EnvZ is a transmembrane osmosensor which regulates the phosphorylation of OmpR, a transcription factor for ompF and ompC genes which encode the major outer membrane porin proteins, OmpF and OmpC in Escherichia coli. Autophosphorylation of EnvZ occurs through a transphosphorylation reaction between two EnvZ molecules. To elucidate the molecular mechanism of signal transduction by EnvZ, we examined the dimer formation of the EnvZ cytoplasmic domain [EnvZ(C)]. For this purpose, we developed a method to determine the complex formation between the purified EnvZ(C) and the purified His6‐EnvZ(C) by means of Ni‐6xhistidine tag affinity chromatography. When the mixture of EnvZ(C) and His6‐EnvZ(C) was applied to Ni‐NTA resin, both His6‐EnvZ(C) and EnvZ(C) were bound to the resin, indicating that EnvZ can form an oligomer without the periplasmic and transmembrane domains. Binding experiments using the Ni‐NTA resin revealed that EnvZ(C) forms a dimer with the K
a value for dimerization being approximately 105 M−1 in the equilibrium state.
Folding intermediates of β‐lactamase recognized by GroEL
Authors: Gervasoni Pietro , Plückthun Andreas
Published: July 2002

β‐Lactamase, from which the disulfide bond was removed by two Cys→Ala mutations, forms stable complexes with GroEL only during the first 30 s of folding, while wild‐type β‐lactamase forms no stable complex under these conditions. The 3‐phasic kinetics of folding are very similar between wild‐type and mutant. After 4 s, Trp‐210 is already juxtaposed to the disulfide bond, but proline cis‐trans isomerization has not yet taken place and almost no enzymatic activity is observed. This shows that GroEL is unable to bind late folding intermediates and also discriminates between the degree of unfolding possible in wild‐type disulfide‐containing β‐lactamase and the Cys‐Ala mutant.
Regulation of leptin receptor and NPY gene expression in hypothalamus of leptin‐treated obese (ob/ob) and cold‐exposed lean mice
Authors: Mercer Julian G , Moar Kim M , Rayner D.Vernon , Trayhurn Paul , Hoggard Nigel
Published: July 2002

Leptin receptor gene expression has been measured in arcuate and ventromedial hypothalamic nuclei. Receptor mRNA in both hypothalamic areas was higher in obese mice than in lean littermates. Twice daily leptin administration for 7 days profoundly affected food intake, reduced leptin receptor mRNA in the arcuate nucleus, and had a similar effect on neuropeptide Y gene expression. A single leptin injection was ineffective. Exposure of lean mice to cold for 24 h caused an induction of leptin receptor and NPY mRNA which was normalized when animals were returned to the warm. Regulation of receptor gene expression may be an important component in the reading of the leptin signal.
Expression of a highly basic peroxidase gene in NaCl‐adapted tomato cell suspensions
Authors: Medina Marı́a I. , Botella Miguel A. , Quesada Miguel A. , Valpuesta Victoriano
Published: July 2002

A tomato peroxidase gene, TPX2, that is only weakly expressed in the roots of young tomato seedlings is highly expressed in tomato suspension cells adapted to high external NaCl concentration. The protein encoded by this gene, with an isolectric point value of ≈9.6, is found in the culture medium of the growing cells. Our data suggest that the expression of TPX2 in the salt‐adapted cells is not the result of the elicitation imposed by the in vitro culture or the presence of high NaCl concentration in the medium.
The effect of some peptides from the hibernating brain on Ca2+ current in cardiac cells and on the activity of septal neurons
Authors: Kokoz Yu.M. , Zenchenko K.I. , Alekseev A.E. , Korystova A.F. , Lankina D.A. , Ziganshin R.H. , Mikhaleva I.I. , Ivanov V.T.
Published: July 2002

The effects of the peptides TSKYR and DY isolated from the brain of hibernating ground squirrels on Ca2+ current were studied. TSKYR activated Ca2+ current in frog auricle fibers and in single cells from frog ventricle whereas DY blocked Ca2+ current in both preparations. In isolated rat and ground squirrel cardiocytes, TSKYR had no effect on Ca2+ current, and DY increased it. In brain slices of rat, DY blocked the activity of medial septal neurons. TSKYR increased activity of septal neurons at the initial phase, which was followed by decrease of neuronal activity.
Structural and functional characterisation of two proteolytic fragments of the bacterial protein toxin, pneumolysin
Authors: Morgan Peter J , Harrison Gayle , Freestone Primrose P.E , Crane Dennis , Rowe Arthur J , Mitchell Timothy J , Andrew Peter W , Gilbert Robert J.C
Published: July 2002

Proteolytic cleavage of the bacterial protein toxin pneumolysin with protease K creates two fragments of 37 and 15 kDa. This paper describes the purification of these two fragments and their subsequent physical and biological characterisation. The larger fragment is directly involved in the cytolytic mechanism of this pore‐forming protein, via membrane binding and self‐association. The smaller fragment lacks ordered structure or discernible activity.
A novel human RasGAP‐like gene that maps within the prostate cancer susceptibility locus at chromosome 1q25
Authors: Noto Satoshi , Maeda Tatsuya , Hattori Seisuke , Inazawa Johji , Imamura Masahiro , Asaka Masahiro , Hatakeyama Masanori
Published: July 2002

We report the molecular cloning of a human cDNA that encodes a molecule having striking homology with Ras‐specific GTPase‐activating proteins (RasGAPs). Among previously described RasGAPs, the cDNA product is most closely related to Caenorhabditis elegans GAP‐2, including a predicted coiled‐coil structure near the carboxyl terminus. Expression of the cDNA in Saccharomyces cerevisiae defective in one of two RasGAPs, Ira2, complemented loss of the Ira2 function, indicating that the cDNA product functions as a RasGAP. The RasGAP‐like gene is located on the human chromosome 1q25, the locus that appears to contain a hereditary prostate cancer susceptible gene, HPC1.
Specificity of novel allosterically trans‐ and cis‐activated connected maxizymes that are designed to suppress BCR‐ABL expression
Authors: Hamada Makiko , Kuwabara Tomoko , Warashina Masaki , Nakayama Aya , Taira Kazunari
Published: July 2002

Chronic myelogenous leukemia (CML) is associated with the presence of the Philadelphia chromosome, which is generated by the reciprocal translocation of chromosomes 9 and 22. In the case of L6 (b2a2) mRNA, it is difficult to cleave the abnormal mRNA specifically because the mRNA includes no sequences that can be cleaved efficiently by conventional hammerhead ribozymes near the BCR‐ABL junction. We recently succeeded in designing a novel maxizyme, which specifically cleaves BCR‐ABL fusion mRNA, as a result of the formation of a dimeric structure. As an extension of our molecular engineering of maxizymes, as well as to improve their potential utility, we examined whether an analogous conformational change could be induced within a single molecule when two maxizymes were connected via a linker sequence. An active conformation was achieved by binding of the construct to the BCR‐ABL junction in trans, with part of the linker sequence then acting as an antisense modulator in cis (within the complex) to adjust the overall structure. Results of studies in vitro in the presence of cetyltrimethylammonium bromide (CTAB) (but not in its absence) suggested that a certain kind of connected maxizyme (cMzB) might be able to undergo a desired conformational change and, indeed, studies in vivo confirmed this prediction. Therefore, we successfully created a fully functional, connected maxizyme and, moreover, we found that the activity and specificity of catalytic RNAs in vivo might be better estimated if their reactions are monitored in vitro in the presence of CTAB.
Improving the quality of obstetric care at the teaching hospital, Zaria, Nigeria
Authors: Ifenne D , Essien E , Golji N , Sabitu K , Alti‐Mu'azu M , Musa A , Adidu V , Mukaddas M
Published: July 2002

Preliminary studies: Research at Ahmadu Bello University Teaching Hospital (ABUTH), Zaria, Nigeria, showed delay in treating women with obstetric complications and highlighted multiple contributing factors. Interventions: In response, a surgical theater was restored to working order, the maternity ward renovated, resident physicians trained in obstetrics and an emergency drug pack system instituted. A system of blood donation from families of women attending antenatal clinics was introduced. Later, community interventions focused on improving access and reducing delay in seeking care. Results: Mean admission‐to‐treatment interval was reduced by 57%, from 3.7 h in 1990 to 1.6 h in 1995. The proportion of women treated in less than 30 min increased from 39% in mid‐1993 to 87% in late 1995. Case fatality rate (CFR) among women with major obstetric complications fell from 14% in 1990 to 11% in 1995. The annual number of women with complications seen, however, declined from 326 in 1990 to 65 in 1995. Costs: Cost of material improvements was approximately US $135 000, of which 65% was provided by government. An additional $8000 per year in new staff salaries was paid by the government. Conclusions: Hospital obstetric services can be improved and government can be mobilized to contribute. Treatment delay and obstetric CFR can be reduced. Deteriorating economic conditions, however, may diminish utilization of services despite improvements. © 1997 International Federation of Gynecology and Obstetrics
Lysosomal involvement in the removal of clofibrate‐induced rat liver peroxisomes. A biochemical and morphological analysis
Authors: Serafini Barbara , Stefanini Stefania , Cerù Maria Paola , Sartori Claudia
Published: July 2002

Peroxisomal proliferators induce in rodents hepatic hyperplasia and hypertrophy; the significant increase in the peroxisomal population is accompanied by specific and reversible induction of some peroxisomal enzymes. In suckling rats born from clofibrate‐treated mothers, a massive removal of proliferated organelles occurs within 3 days of recovery. In the present paper we examined the early stages of the recovery period in liver of male rats treated with clofibrate for 5 days. The lysosomal involvement in the removal of drug‐induced peroxisomes was investigated under physiological conditions, ie in the absence of inhibitors of the autophagic process. Biochemical results indicate that peroxisomal β‐oxidation, but not catalase activity, returns to the control values within the examined period. Total acid phosphatase activity is not affected by clofibrate treatment, but following fractionation on a linear density gradient the lysosomal marker enzyme activity is shifted towards lower density values, particularly at day 1 and 2 of recovery. This class of organelles possibly represents lysosomes involved in active autophagic processes. Acid phosphatase cytochemistry shows an increase of lysosome number at day 1 of recovery. Combination of acid phosphatase cytochemistry either with catalase cytochemistry or with catalase immunogold labelling allows to reveal organelles containing both marker enzymes. These results strongly support the involvement of autophagic processes in the removal of proliferated peroxisomes.
Health care costs of heart failure: results from a randomised study of patient education
Authors: Linné A. Björck , Liedholm H. , Jendteg S. , Israelsson B.
Published: July 2002

Background:

Heart failure is a serious syndrome with a bad prognosis. Hospitalisation is common and readmittance rate is high; factors which influence the cost of care and treatment. Only scarce data on detailed patient materials regarding health care costs are known.

Aims:

To describe in detail the health care costs for heart failure patients.

Methods:

Costs for patients (n = 108) who completed a randomised education trial were studied for 6 months after hospital discharge. Costs for hospital stay, out‐patient visits, diagnostic tests and procedures, laboratory analyses and drug treatment were calculated. Official unit prices list used to reimburse providers of cross‐boundary health services and prices for drugs in the Swedish Drug Compendium were employed.

Results

The total cost for a heart failure patient was approximately 20000 SEK (2564 US$, 7.80 SEK = 1 US$) for 6 months. There was a 27‐fold variation between patients. There was no relation between age or sex and cost. In decreasing order cost for hospitalisation was followed by costs for out‐patient visits, diagnostic tests and procedures, laboratory analyses and drugs.

Conclusion:

Hospitalisation was the largest part of the total cost and there was a large inter‐individual variation. Efforts to reduce the economic burden should be focused on hospitalisation. Due to skewed distribution, individual data must be considered in the analysis of the efforts.
Patterns of emergency shelters in coastal plains a case study after the great east Japan Earthquake and Tsunami in Higashi‐Matsushima City
Authors: Araki Yuko , Tsuboi Sotaro , Hokugo Akihiko
Published: August 2020

It has been pointed out that during large‐scale disasters, some evacuees cannot receive necessary support since they evacuate to places other than the shelters pre‐designated by the government. This is due to the fact that prior evacuation plans do not match the actual evacuation situation, and that the information collection and support system are not examined thoroughly beforehand. This research aims to contribute to the provision of measures on how to prepare for the occurrence of non‐designated shelters and evacuees and provide immediate support activities for evacuees after a disaster. From a case study of events in Higashi‐Matsushima during the Great East Japan Earthquake, we examined the occurrence and causes of evacuation within the coastal plains and showed that non‐designated shelters were also found in flooded areas of coastal plains.
Ecolinguistics
Authors: Stanlaw James
Published: August 2020

The International Ecolinguistics Association defines “ecolinguistics” as a field which “explores the role of language in the life‐sustaining interactions of humans, other species and the physical environment.” It is concerned with how the language used to talk about the environment contributes to its degradation, and also how linguistic diversity, like biodiversity, makes for a healthy planet.
Language and Sexuality: Language andLGBTQ+Communities
Authors: Calder Jeremy
Published: August 2020

Studies of the language of queer speakers – i.e. speakers whose gender and/or sexual identities fall outside of the normative heterosexual binary – have followed a trajectory largely mirroring evolutions in the greater field of sociolinguistics. While early sociolinguistic research searched for large‐scale linguistic differences patterning according to broad macro‐social demographic differences, the field in recent decades has increasingly implemented ethnographic, context‐sensitive analyses exploring how individuals use language to construct and project a range of locally meaningful identities on the ground. In the same way, studies of speakers with queer identities were initially concerned with discovering linguistic differences between queer and straight speakers, but have increasingly come to emphasize the diversity of queer voices in various contexts and how these voices contribute to the construction of a range of queer identities.
Presupposition and Entailment
Authors: Sidnell Jack
Published: August 2020

The terms “presupposition” and “entailment” refer to fundamental operations of human thinking which are of central relevance to language use and social interaction. While in linguistic pragmatics and the philosophy of language presupposition and entailment are typically conceptualized in terms of relations between propositions or between a speaker's utterance and her beliefs, in linguistic anthropology they are most useful in helping us to understand the relation between speech signal (or any other form of conduct) and its context of occurrence.
Augmentation in restless legs syndrome: an eye tracking study on emotion processing
Authors: Ellmerer Philipp , Heim Beatrice , Stefani Ambra , Peball Marina , Werkmann Mario , Holzknecht Evi , Bergmann Melanie , Brandauer Elisabeth , Sojer Martin , Zamarian Laura , Delazer Margarete , Seppi Klaus , Högl Birgit , Poewe Werner , Djamshidian Atbin
Published: August 2020

Objective

To assess emotional processing and alexithymia in patients with restless legs syndrome (RLS) with augmentation versus those who never had augmentation.

Methods

We recruited 26 patients who had a history of augmentation (AUG), either current or past, 27 RLS patients treated with dopamine agonists who never had augmentation (RLS controls), and 21 healthy controls (HC). All participants were screened for impulse control disorders (ICDs). Alexithymia was assessed by means of the Toronto Alexithymia Scale – 20 (TAS‐20). Facial emotion recognition was tested through an eye‐tracking task. Furthermore, all participants performed neuropsychological tests assessing global cognitive status, impulsivity, anxiety, and depression.

Results

ICD symptoms occurred more frequently in AUG patients than in RLS controls (P = 0.047). Patients with AUG scored higher on the TAS‐20 (P = 0.007) and the attentional subdomain of an impulsivity scale (BIS‐11; P = 0.015) compared to HC. Patients with AUG also performed worse on the facial emotion recognition task relative to RLS controls (P = 0.009) and HC (P = 0.003). We found a group difference for the time to first fixation and the fixation count in the mouth region (P = 0.019 and P = 0.021, respectively). There were no other differences in the eye tracking examination.

Interpretation

This study showed evidence of poorer emotional processing in patients who had augmentation compared to RLS patients without augmentation and healthy controls. The altered exploration pattern of faces and the higher alexithymia scores suggest abnormalities in emotion processing in patients with augmentation.
Helical Networks of π‐Conjugated Rods – A Robust Design Concept for Bicontinuous Cubic Liquid Crystalline Phases with Achiral Ia3¯d and Chiral I23 Lattice
Authors: Dressel Christian , Reppe Tino , Poppe Silvio , Prehm Marko , Lu Huanjun , Zeng Xiangbing , Ungar Goran , Tschierske Carsten
Published: August 2020

Bicontinuous cubic liquid crystalline phases of π‐conjugated molecules, representing self‐assembled 3D‐ordered interpenetrating networks with cubic symmetry, are receiving increasing attention due to their capacity for charge transport in all three dimensions and their inherent spontaneous helicity. Herein, a robust general design concept for creating bicontinuous cubic phases is reported. It is based on a nonsymmetric‐substituted π‐conjugated 5,5′‐diphenyl‐2,2′‐bithiophene platform with one end containing three out‐fanning flexible chains and with a range of substituents at the other end (the apex). The cubic phases are stable over broad temperature ranges, often down to ambient temperature, and tolerate a wide range of apex substitution patterns, allowing structural diversity and tailoring of the cubic phase type and application‐relevant properties. With an increasing number and size of apex substituents, a sequence of three different modes of cubic self‐assembly is observed, following an increasing helical twist. Thus, two ranges of the achiral double network Iad phase range can be distinguished, a long pitch and a short pitch, with the chiral triple network I23 cubic phase in the intermediate pitch range. The findings provide a new prospect for the directed design of cubic phase‐forming functional materials based on spontaneously formed helical network liquid crystals with tunable application specific properties.
Planar Organic‐Si Hybrid Solar Cell with MoOx Mixed PEDOT:PSS as Hole Injection Layer Profits from Mo5+ and Mo6+ Synergistic Effects
Authors: Fang Wenzhong , Wang Pan , Ni Zitao , Sun Tao , Xiang Chaoyu , Yue Kun , Wang Rongfei , Yang Jie , Zhou Yao , Wang Chong , Yang Yu
Published: August 2020

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole injection layer plays an important role in planar Si/PEDOT:PSS heterojunction solar cells (HSCs). Herein, a MoOx mixed aqueous PEDOT:PSS cosolvent is developed and is applied into a Si/PEDOT:PSS solar cell preparation via a time‐saving one‐step spin‐coating method. With an optimal concentration of MoOx dopants, the power conversion efficiency of the device exhibits from 10.26% up to 13.82% with all inherent photovoltaic parameters enhanced. The detailed characterization and analytical results indicate that an advanced electronic property is produced by MoOx dopants and interface optimization caused by synergistic effects from Mo5+ and Mo6+ species with PEDOT:PSS, which enhances its interface work function and promotes hole transportation capacity. The result paves a path for exploring efficient Si/PEDOT:PSS HSCs with suitable functional material and a simple solution‐processable method.