bluuebunny/crossref_metadata_2025 huggingface dataset:
β‐Lactoglobulin binds retinol and protoporphyrin IX at two different binding sites
Authors: Dufour Eric , Marden Michael C. , Haertlé Tomasz
Published: July 2002

Measurement of tryptophan fluorescence quenching and the excitation energy transfer from tryptophanyl residues to the bound ligand indicates that β‐lactoglobulin binds tightly to hemin and protoporphyrin IX in a ligand‐to‐protein stoichiometric ratio. The apparent dissociation constants of hemin‐β‐lactoglobulin and protoporphyrin IX‐β‐lactoglobulin complexes are 2.5 × 10−7 M and 4 × 10−7 M, respectively. The addition of β‐lactoglobulin (final concentration = 10 μM, phosphate buffer 50 mM, pH 7.1) to the solution containing retinol and protoporphyrin IX triggers an energy transfer between β‐lactoglobulin tryptophan and protoporphyrin IX as well as between retinol and protoporphyrin IX. The efficiency of energy transfer depends on the distance between the donor (retinol) and the acceptor (protoporphyrin IX). Using the Förster theory, a retinol‐protoporphyrin IX distance of 25 Å was calculated. These results indicate that retinol and protoporphyrin IX are bound to the β‐lactoglobulin monomer at two different sites.
Genomic organization and full‐length cDNA sequence of human collagen X
Authors: Reichenberger Ernst , Beier Frank , LuValle Phyllis , Olsen Bjorn R. , von der Mark Klaus , Bertling Wolf M.
Published: July 2002

We have determined the full‐length cDNA sequence of the human αl(X) collagen gene by sequence analysis of a genomic clone ERG [(1991) Dev. Biol. 148, 562–572], and of cDNA fragments generated from a reverse transcribed as αl(X) mRNA by PCR. We defined the promoter region, the transcription initiation site and the full‐length 5′‐untranslated region. We also report the exon/intron boundaries of the transcript and the complete 3′‐untranslated region as well as a 3′‐flanking sequence containing two additional polyadenylation signals. The promoter region is homologous to chicken and mouse type X promoters within several highly conserved regions. The genomic organization shows high homologies to chicken and mouse.
Glycosyl‐phosphatidylinositol‐specific phospholipase D
Authors: Hoener Marius C. , Bolli Reinhard , Brodbeck Urs
Published: July 2002

Glycosyl‐phosphatidylinositol‐specific phospholipase D (GPI‐PLD) is an amphiphilic protein which, in serum, is associated with high‐density lipoproteins (HDL). It is shown that the major component of the HDL fraction, apolipoprotein A‐I (apo A‐I), is responsible for this association. In the absence of apo A‐I, purified GPI‐PLD occurred as virtually inactive aggregates which became disaggregated by apo A‐I. The enzyme/apo A‐I complex efficiently hydrolyzed the solubilized GPI‐anchored substrate, acetylcholinesterase. Triton X‐100 was also able to dissociate aggregated GPI‐PLD, however, it strongly inhibited enzyme activity at detergent concentrations above the critical micellar concentration.
Molecular cloning of a murine N‐type calcium channel α1 subunit
Authors: Coppola Thierry , Waldmann Rainer , Borsotto Marc , Heurteaux Catherine , Romey Georges , Mattéi Marie-Geneviève , Lazdunski Michel
Published: July 2002

A cDNA encoding a N‐type Ca2+ channel has been cloned from the murine neuroblastoma cell line N1A103. The open reading frame encodes a protein of 2,289 amino acids (257 kDa). Analysis of different clones provided evidence for the existence of distinct isoforms of N‐type channels. High levels of mRNA were found in the pyramidal cell layers CA1, CA2 and CA3 of the hippocampus, in the dentate gyrus, in the cortex layers 2 and 4, in the subiculum and the habenula. The N‐type Ca2+ channel gene has been localized on the chromosome 2, band A.
2,4‐diamino‐6‐hydroxypyrimidine, an inhibitor of tetrahydrobiopterin synthesis, downregulates the expression of iNOS protein and mRNA in primary murine macrophages
Authors: Bogdan Christian , Werner Ernst , Stenger Steffen , Wachter Helmut , Rbllinghoff Martin , Werner-Felmayer Gabriele
Published: July 2002

2,4‐diamino‐6‐hydroxy‐pyrimidine (DAHP), an inhibitor of GTP cyclohydrolase I, blocks the synthesis of tetrahydrobiopterin (BH4), which is a known cofactor of inducible nitric oxide synthase (iNOS). Previously, DAHP was shown to suppress the production of nitric oxide by cytokine‐activated fibroblasts, smooth muscle cells or endothelial cells which could be attributed to its function as a cofactor antagonist. Here, we demonstrate that in interferon‐γ‐activated murine peritoneal macrophages DAHP suppresses the expression of iNOS mRNA and protein in a BH4‐independent manner and, thus, acts by a novel mechanism.
A novel Ca2+‐dependent step in exocytosis subsequent to vesicle fusion
Authors: Hartmann Jana , Lindau Manfred
Published: July 2002

Exocytosis begins with formation of a small fusion pore which then expands allowing rapid release of granular contents. We studied the influence of cytoplasmic free Ca2+ ([Ca2+]i) on the conductance of the initial pore and on the dynamics of subsequent expansion in horse eosinophils using the patch clamp technique. The mean initial conductance is ∼200 pS independent of [Ca2+]i. This value is close to that previously found in beige mouse mast cells. The pore subsequently expands by 18 nS/s at [Ca2+]i < 10 nM, by 40 nS/s at [Ca2+]i = 1.5 μM and by 90 nS/s at [Ca2+]i = 10 μM. These results show that the structure of the initial fusion pore is independent of cytoplasmic Ca2+. However, the pore expansion is a Ca2+‐dependent process modulating secretion at a step later than vesicle‐plasma membrane fusion.
Sudden depletion of carbon source blocks translation, but not transcription, in the yeast Saccharomyces cerevisiae
Authors: Martínez-Pastor M.T. , Estruch F.
Published: July 2002

Expression of invertase in the yeast Saccharomyces cerevisiae is greatly delayed when derepression occurs in a medium that lacks a usable carbon source. The delay is not a consequence of defects in the transcription of the SUC2 gene but is due to the impossibility of translating the normal levels of mRNA generated under derepressing conditions. The inhibition of translation in the absence of glucose has to be considered when reporter genes such as E. coli lacZ are used to measure transcription in conditions of carbon source starvation.
The epidemiology of illicit and licit drug use in Greece: a nationwide general population survey
Authors: Madianos MG , Gefou-Madianou D , Stefanis CN
Published: July 2002

A cross-sectional home survey on the epidemiology of drug use in Greece, with a nationwide general population sample of 4,291 respondents aged 12 to 64, was carried out. The weighted life prevalence of reported illicit drug use in the total sample was found to be 9% among males and 2.5% among females, with a ratio of 3.6: 1. Six and a half percent of males of all ages had used, at some time, licit psychotropic drugs without a doctor's order, while females presented much higher prevalence rates (14.9%). Young adults reported higher rates of both illicit and licit lifetime and past-year use, compared to the other age groups. Illicit drug use was less common, in females of all ages. Cannabis was the most common illicit drug used. Current as well as lifetime use of pain relievers without a doctor's prescription was found to be highest among all other licit substances. This holds true for all age groups and for both sexes. Tranquillizers were predominantly used by females of all ages. Certain sociodemographic variables, such as sex, educational level, marital status, place of residence and occupational status were found to be related to drug use in Greece.
Inositol polyphosphate multikinase (ArgRIII) determines nuclear mRNA export inSaccharomyces cerevisiae
Authors: Saiardi Adolfo , Caffrey James J , Snyder Solomon H , Shears Stephen B
Published: July 2002

TheARGRIIIgene ofSaccharomyces cerevisiaeencodes a transcriptional regulator that also has inositol polyphosphate multikinase (ipmk) activity [Saiardi et al. (1999) Curr. Biol. 9, 1323–1326]. To investigate how inositol phosphates regulate gene expression, we disrupted theARGRIIIgene. This mutation impaired nuclear mRNA export, slowed cell growth, increased cellular [InsP3] 170‐fold and decreased [InsP6] 100‐fold, indicating reduced phosphorylation of InsP3to InsP6. Levels of diphosphoinositol polyphosphates were decreased much less dramatically than was InsP6. Low levels of InsP6, and considerable quantities of Ins(1,3,4,5)P4, were synthesized by an ipmk‐independent route. Transcriptional control by ipmk reflects that it is a pivotal regulator of nuclear mRNA export via inositol phosphate metabolism.
M‐ABC2, a new human mitochondrial ATP‐binding cassette membrane protein
Authors: Zhang Fang , Hogue Douglas L. , Liu Lin , Fisher Cynthia L. , Hui David , Childs Sarah , Ling Victor
Published: July 2002

We have isolated a human cDNA encoding a novel ATP‐binding cassette (ABC) protein whose gene was previously localized to chromosome 1q42 [Allikmets et al. (1995) Mamm. Genome 6, 111–117]. The gene transcript is expressed in all human tissues examined, with the highest levels in bone marrow. A non‐expressed pseudogene also exists at chromosome 15q13–14. The new protein, which is most similar to the mitochondrial (M)‐ABC1 protein, was also localized to mitochondria and therefore designated ‘M‐ABC2’. The N‐terminus of M‐ABC2 was shown to contain a mitochondrial‐targeting signal sequence.
Cleavage of yeast tRNAPhe with complementary oligonucleotide conjugated to a small ribonuclease mimic
Authors: Beloglazova N.G. , Sil'nikov V.N. , Zenkova M.A. , Vlassov V.V.
Published: July 2002

An oligonucleotide conjugate bearing a chemical construct mimicking the catalytic center of ribonuclease A has been designed and studied. The conjugate efficiently cleaves yeast tRNAPhe at a single site adjacent to the target complementary sequence.
Unlocking the allergenic structure of the major house dust mite allergen Der f 2 by elimination of key intramolecular interactions
Authors: Takai Toshiro , Ichikawa Saori , Yokota Toyokazu , Hatanaka Hideki , Inagaki Fuyuhiko , Okumura Yasushi
Published: July 2002

We report on the structural background of the remarkable reduction of allergenicity in engineering of the major house dust mite allergen Der f 2. Disruption of intramolecular disulfide bonds in Der f 2 caused extensive conformational change that was monitored by circular dichroism and gel‐filtration analysis. The degree of conformational change correlated well with the degree of reductions in the capacity to bind IgE and to induce histamine release from basophils in mite‐allergic patients. Loosening the rigid tertiary structure by elimination of key intramolecular interactions is an effective strategy to reduce the number of high affinity IgE epitopes of allergen vaccine.
Function of the cytosolic N‐terminus of sucrose transporter AtSUT2 in substrate affinity
Authors: Schulze Waltraud , Weise Andreas , Frommer Wolf B. , Ward John M.
Published: July 2002

AtSUT2 was found to be a low‐affinity sucrose transporter (K
M=11.7 mM at pH 4). Chimeric proteins between AtSUT2 and the high‐affinity StSUT1 were constructed in which the extended N‐terminus and central loop of AtSUT2 were exchanged with those domains of StSUT1 and vice versa. Chimeras containing the N‐terminus of AtSUT2 showed significantly lower affinity for sucrose compared to chimeras containing the N‐terminus of StSUT1. The results indicate a significant function of the N‐terminus but not the central cytoplasmic loop in determining substrate affinity. Expression of AtSUT2 in major veins of source leaves and in flowers is compatible with a role as a second low‐affinity sucrose transporter or as a sucrose sensor.
Shiga toxin activates p38 MAP kinase through cellular Ca2+ increase in Vero cells
Authors: Ikeda Masahiro , Gunji Yasuhiro , Yamasaki Shinji , Takeda Yoshifumi
Published: July 2002

We examined whether the mitogen‐activated protein kinase (MAPK) pathway is involved in Shiga toxin (Stx)‐induced Vero cell injury. Consonant with cell injury, Stx caused a transient extracellular signal‐regulated kinase1/2 (ERK1/2) and a sustained p38 MAPK phosphorylation. p38 MAPK inhibitors (SB 203580 and PD 169316), but not an ERK1/2 kinase inhibitor (PD 98059), partially inhibited the Stx‐induced cell death. BAPTA‐AM, a Ca2+ chelator, reduced both cell injury and p38 MAPK phosphorylation. Antioxidants reduced Stx1‐induced p38 MAPK phosphorylation. These data indicate that Stx activates p38 MAPK through an increase in intracellular Ca2+ and reactive oxygen species, and this signaling is involved in Stx‐induced cell death.
Characterization of an intradiol dioxygenase involved in the biodegradation of the chlorophenoxy herbicides 2,4‐D and 2,4,5‐T
Authors: Travkin V.M , Jadan A.P , Briganti F , Scozzafava A , Golovleva L.A
Published: July 2002

Hydroxyquinol 1,2‐dioxygenase, an intradiol dioxygenase, which catalyzes the cleaving of the aromatic ring of hydroxyquinol, a key intermediate of 2,4‐D and 2,4,5‐T degradation, was purified from Nocardioides simplex 3E cells grown on 2,4‐D as the sole carbon source. This enzyme exhibits a highly restricted substrate specificity and is able to cleave hydroxyquinol (K
m for hydroxyquinol as a substrate was 1.2 μM, V
max 55 U/mg, K
cat 57 s−1 and K
cat/K
m 47.5 μM s−1), 6‐chloro‐ and 5‐chlorohydroxyquinol. Different substituted catechols and hydroquinones are not substrates for this enzyme. This enzyme appears to be a dimer with two identical 37‐kDa subunits. Protein and iron analyses indicate an iron stoichiometry of 1 iron/65 kDa homodimer, α2 Fe. Both the electronic absorption spectrum which shows a broad absorption band with a maximum at 450 nm and the electron paramagnetic resonance spectra are consistent with a high‐spin iron(III) ion in a rhombic environment typical of the active site of intradiol cleaving enzymes.
Activation of MAP kinase cascade induced by human pancreatic phospholipase A2 in a human pancreatic cancer cell line
Authors: Kinoshita Eiji , Handa Noriko , Hanada Keiji , Kajiyama Goro , Sugiyama Masanori
Published: July 2002

We have found that the growth of human pancreatic cancer cells MIAPaCa‐2, induced by human pancreatic phospholipase A2 group I (hPLA2‐I), is mediated via its specific receptor but not via its catalytic property. The present study showed that the activation of mitogen‐activated protein kinase (MAPK) cascade in MIAPaCa‐2 cells is induced by hPLA2‐I: this digestive enzyme induced phosphorylation of MEK1/2, p44/42 MAPK and ATF‐2, and the phosphorylation in the MAPK cascade was inhibited after the cells were pre‐incubated with a selective inhibitor of MEK, PD98059. In addition, this inhibitor dose‐dependently blocked the hPLA2‐I‐induced MIAPaCa‐2 proliferation, suggesting that activation of the MAPK cascade is essential for the hPLA2‐I‐induced MIAPaCa‐2 proliferation.
Purification, biochemical properties and substrate specificity of a catechol 1,2‐dioxygenase from a phenol degrading Acinetobacter radioresistens
Authors: Briganti Fabrizio , Pessione Enrica , Giunta Carlo , Scozzafava Andrea
Published: July 2002

A catechol 1,2‐dioxygenase (C1,2O) has been purified to homogeneity from Acinetobacter radioresistens grown on phenol as the sole carbon and energy source. The C1,2O appears to be a homodimer, with a molecular mass of 78 000 Da. At relatively high ionic strengths (0.5 M Na2SO4) subunit dissociation occurs and the monomeric unit (38 700 Da) is shown to be active. This phenomenon has never been observed before in dioxygenases. The purified C1,2O contains 0.96 iron(III) ions per unit and spectroscopic measurements suggest the presence of one high‐spin iron(III) ion in an environment characteristic of intradiol cleaving enzymes. The NH2‐terminal amino acid sequence has been determined and compared to the primary structures of intradiol rings cleaving dioxygenases from other Acinetobacter strains revealing 45% homology with the benzoate‐grown A. calcoaceticus ADP‐1 and an identity of only one of the 20 amino acids sequenced for the phenol‐grown A. calcoaceticus NCIB 8250.
Regeneration of ultraviolet pigments of vertebrates
Authors: Yokoyama Shozo , Radlwimmer F.Bernhard , Kawamura Shoji
Published: July 2002

We report here the regeneration of the visual pigments of mouse, rat, goldfish and pigeon, which have wavelengths of maximal absorption at 359 nm, 358 nm, 359 nm, and 393 nm, respectively. The construction and functional assays of the ultraviolet or near‐ultraviolet pigments from a wide range of vertebrate species will allow us to study the molecular bases of ultraviolet vision for the first time.
A synthetic human Agouti‐related protein‐(83–132)‐NH2 fragment is a potent inhibitor of melanocortin receptor function
Authors: Quillan J.Mark , Sadée Wolfgang , Wei Edward T , Jimenez Charles , Ji Li , Chang J.-K
Published: July 2002

Chemical synthesis of Agouti proteins – Agouti and Agouti‐related proteins – is complicated by their large size and by multiple cysteine residues located in the carboxyl terminal regions. Three human Agouti‐related protein (AGRP) fragments, two of which correspond to a proposed endoprotease cleavage site between amino acids 82 and 83, were synthesized and tested for anti‐melanotropic activity using Xenopus laevis dermal melanophores. Amino‐terminal fragments AGRP(25–51) and (54–82) were devoid of significant antagonist activity, whereas the amidated carboxyl‐terminal AGRP fragment (83–132)‐NH2 was potently active with an inhibitory equilibrium dissociation constant (K
i) of 0.7 nM. The ability to synthesize functionally active AGRP should help unravel its role in the central nervous system and its unusual properties with respect to interaction with the melanocortin family of G‐protein coupled receptors.
Formation of a high affinity heregulin binding site using the soluble extracellular domains of ErbB2 with ErbB3 or ErbB4
Authors: Fitzpatrick V.Danial , Pisacane Paul I , Vandlen Richard L , Sliwkowski Mark X
Published: July 2002

ErbB2 functions as a shared signal transducing component for other ErbB receptor family members. Two of these receptors, ErbB3 and ErbB4, bind the heregulin (HRG) or neuregulin family of polypeptide growth factors. Cells expressing ErbB3 alone display a single class of low affinity HRG binding sites, whereas both high and low affinity binding sites can be measured on cells that co‐express both ErbB3 and ErbB2. To assess the interaction of the extracellular domains of ErbB receptors, a series of soluble homodimeric and heterodimeric IgG fusion proteins were constructed. Heregulin binding analysis revealed that a heterodimer composed of either ErbB3 or ErbB4 with ErbB2 is sufficient for the formation of a high affinity binding state. In contrast, heterodimeric ErbB3/4‐IgG, as well as homodimeric ErbB3‐IgG or ErbB4‐IgG, contained only low affinity HRG binding sites. Further evidence for the unique specificity of ErbB2 in generating this high affinity binding site was determined by inhibiting HRG binding with an ErbB2 monoclonal antibody.
Intracellular localization and release of eotaxin from normal eosinophils
Authors: Nakajima Toshiharu , Yamada Hirokazu , Iikura Motoyasu , Miyamasu Misato , Izumi Shinyu , Shida Hisato , Ohta Ken , Imai Toshio , Yoshie Osamu , Mochizuki Mitsuru , Schröder Jens-M , Morita Yutaka , Yamamoto Kazuhiko , Hirai Koichi
Published: July 2002

Eotaxin is a potent and selective CC chemokine for eosinophils and basophils. We established several monoclonal antibodies (Mabs) allowing the neutralization and measurement of human eotaxin. Using the Mabs as probes, we demonstrated that normal eosinophils contained intracellular granule‐associated eotaxin. Quantification of cell‐associated eotaxin in different leukocyte subsets revealed that it was principally expressed in eosinophils. Finally, we showed that normal eosinophils released eotaxin upon stimulation with either of two secretagogues, C5a or ionomycin. These findings raise the possibility that eosinophil‐derived eotaxin contributes to the local accumulation of eosinophils at the site of inflammation.
Interaction between the Arabidopsis thaliana heat shock transcription factor HSF1 and the TATA binding protein TBP
Authors: Reindl Andreas , Schöffl Fritz
Published: July 2002

The heat shock factor (HSF1) is the central regulator of the heat stress (hs) response and is required for stimulating the transcription of the hs genes and consequently the expression of heat shock proteins. To promote the polymerase II‐dependent transcription of the hs genes, HSF has to communicate with the basal transcription machinery. Here, we report that the Arabidopsis thaliana HSF1 interacts directly with TBP, the general TATA box binding transcription factor, as shown by affinity chromatography and electrophoretic mobility shift analyses in vitro. An in vivo interaction between AtHSF1 and AtTBP1 was suggested by results employing the yeast two‐hybrid system.
Purification and characterization of a major 40 kDa outer membrane protein of Acinetobacter baumannii
Authors: Jyothisri Kondapalli , Deepak V. , Rajeswari Moganty R.
Published: July 2002

Acinetobacter baumannii, an opportunistic pathogen, is well known to cause a wide spectrum of nosocomial infections particularly in intensive care units. The major outer membrane (OM) protein, OmpAb, of 40 kDa from A. baumannii has been identified and purified to homogeneity from cultures grown at 30°C and 100 mM NaCl. The synthesis of OM proteins of A. baumannii is thermoregulated and osmoregulated. The pore forming ability of the purified OmpAb and the diffusion of uncharged solutes in proteoliposomes has been demonstrated by following the liposomal swelling assay. The trimeric OmpAb is characterized as a porin with a pore size of 1.3 nm and is found to be similar to the OmpF of Escherichia coli and can possibly be classified as a general diffusion pore. It appears that OmpAb plays an important role in the diffusion properties of the outer membrane of A. baumannii.
Raf‐1 is activated by the p38 mitogen‐activated protein kinase inhibitor, SB203580
Authors: Kalmes Andreas , Deou Jessie , Clowes Alexander W , Daum Günter
Published: July 2002

SB203580 (4‐(4‐fluorophenyl)‐2‐(4‐methylsulfinylphenyl)‐5‐(4‐pyridyl)1H‐imidazole) is widely used as a specific inhibitor of p38 mitogen‐activated protein kinase (MAPK). Here, we report that SB203580 activates the serine/threonine kinase Raf‐1 in quiescent smooth muscle cells in a dose‐dependent fashion. The concentrations of SB203580 required lie above those necessary to inhibit p38 MAPK and we were unable to detect basal levels of active p38 MAPK. SB203580 does not directly activate Raf‐1 in vitro, and fails to activate Ras, MEK, and ERK in intact cells. In vitro, however, SB203580‐stimulated Raf‐1 activates MEK1 in a coupled assay. We conclude that activation of Raf‐1 by SB203580 is not mediated by an inhibition of p38 MAPK, is Ras‐independent, and is uncoupled from MEK/ERK signaling.
Binding of oligopyrimidines to the RNA hairpin responsible for the ribosomegag‐polframeshift in HIV‐1
Authors: Aupeix Karine , Le Tinévez Réjane , Toulmé Jean-Jacques
Published: July 2002

The 12 bp stem of the RNA hairpin responsible for thegag‐polframeshifting of the ribosomes during translation of the polycistronic HIV‐1 mRNA has a pyrimidine‐rich 5′ strand and, consequently, a purine‐rich 3′ strand. Electrophoretic mobility shift assays have shown that DNA oligopyrimidines, 12 and 20 nucleotides long (but not oligopurines or G,T‐containing oligomers), designed to form triplexes actually bind to the double‐stranded RNA target. RNase V1 footprinting studies have confirmed the interaction between the hairpin stem and the. RNA and 2′‐O‐methyl oligoribonucleotide analogues of the 12‐mer oligodeoxypyrimidine as well as 5 propynyl,cytosine, containing the 12‐mer oligodeoxypyrimidine, bind more strongly to the RNA target than the unmodified parent DNA oligomer. The complexes formed by the RNA hairpin and either the 12‐mer oligodeoxypyrimidine or the 20‐mer oligopyrimidine are stable at a neutral pH and in the absence of Mg2+but blocked neither the reverse transcription nor cell‐free translation of a RNA template in which thegag‐polframeshifting hairpin was inserted at the 5′ end of the luciferase open reading frame.
Calpain controls the balance between protein tyrosine kinase and tyrosine phosphatase activities during platelet activation
Authors: Pain Sabine , Monstero-Lastres Alfonso , Falet Hervé , Brohard-Bohn Brigitte , Fraiz Nuria , Bachelot-Loza Christilla , Cano Ernesto , Rendu Francine
Published: July 2002

Protein phosphorylation was studied during platelet stimulation in two ranges of ionized [Ca2+]. At ionized [Ca2+]i≤1 μM, proteins were phosphorylated. At ionized [Ca2+]i≥4 μM, phosphoproteins disappeared. Protein dephosphorylation was prevented by the combined action of calpeptin and phosphatase inhibitors. Protein tyrosine phosphatase activity was stimulated regardless of the ionized [Ca2+]i level. Protein tyrosine kinase activity was stimulated at ionized [Ca2+]i≤1 μM, whereas at ionized [Ca2+]i≥4 μM, no protein tyrosine kinase activity was observed except in the presence of calpeptin. Thus, the massive tyrosine phosphoprotein disappearance observed at a high ionized [Ca2+]i resulted not only in protein tyrosine phosphatase activation, but also in calpain‐induced protein tyrosine kinase inactivation.
Regions in vertebrate photoreceptor guanylyl cyclase ROS‐GC1 involved in Ca2+‐dependent regulation by guanylyl cyclase‐activating protein GCAP‐1
Authors: Lange Christian , Duda Teresa , Beyermann Michael , Sharma Rameshwar K. , Koch Karl-Wilhelm
Published: July 2002

The membrane bound guanylyl cyclase (GC) photoreceptor membrane GC1 (ROS‐GC1) of photoreceptor cells synthesizes cGMP, the intracellular transmitter of vertebrate phototransduction. The activity of ROS‐GC1 is controlled by small Ca2+‐binding proteins, named GC‐activating proteins (GCAPs). We identified and characterized two short regulatory regions (M445–L456 and L503–I522) in the juxtamembrane domain (JMD) of ROS‐GC1 by peptide competition and mutagenesis studies. Both regions are critical for the activation of ROS‐GC1 by GCAP‐1.
Variability in the ratio of mutant to wildtype myosin heavy chain present in the soleus muscle of patients with familial hypertrophic cardiomyopathy. A new approach for the quantification of mutant to wildtype protein
Authors: Nier Volker , Schultz Imke , Brenner Bernhard , Forssmann Wolf-Georg , Raida Manfred
Published: July 2002

The ratio of mutant to wildtype myosin heavy chain (β‐isoform, β‐MHC) in the soleus muscle of patients with familial hypertrophic cardiomyopathy was determined by a combination of HPLC, mass spectrometry and capillary zone electrophoresis. In two patients, one with a Val 606 Met mutation and another with a Gly 584 Arg mutation, the fraction of mutant β‐MHC was only 12±6% and 23±0.7% of total β‐MHC, respectively. These results demonstrate the necessity to determine the ratio of mutant to wildtype protein for the interpretation of functional studies on biopsy material from heterozygous patients with an inherited disease.
Fluorescence labeling of the C‐terminus of proteins with a puromycin analogue in cell‐free translation systems
Authors: Nemoto Naoto , Miyamoto-Sato Etsuko , Yanagawa Hiroshi
Published: July 2002

We have developed a new method for the C‐terminus‐specific fluorescence labeling of proteins. This method is based on the experimental finding that a fluorescent puromycin analogue at lower concentrations bonds efficiently to the C‐terminus of mature proteins in cell‐free translation systems using mRNA without a stop codon. This labeling is performed under moderate conditions and its labeling efficiency is in the range of 50–95%. Here we demonstrate a protein‐protein interaction assay using fluorescence polarization measurement. This labeling method should also be useful for other rapid molecular interaction assays without purification of the labeled proteins, such as fluorescence correlation spectroscopy.
Characterization of a core α1→3‐fucosyltransferase from the snail Lymnaea stagnalis that is involved in the synthesis of complex‐type N‐glycans
Authors: van Tetering Angelique , Schiphorst Wietske E.C.M , van den Eijnden Dirk H , van Die Irma
Published: July 2002

We have identified a core α1→3‐fucosyltransferase activity in the albumin and prostate glands of the snail Lymnaea stagnalis. Incubation of albumin gland extracts with GDP‐[14C]Fuc and asialo/agalacto‐glycopeptides from human fibrinogen resulted in a labeled product in 50% yield. Analysis of the product by 400 MHz 1H‐NMR spectroscopy showed the presence of a Fuc residue α1→3‐linked to the Asn‐linked GlcNAc. Therefore, the enzyme can be identified as a GDP‐Fuc:GlcNAc (Asn‐linked) α1→3‐fucosyltransferase. The enzyme acts efficiently on asialo/agalacto‐glycopeptides from both human fibrinogen and core α1→6‐fucosylated human IgG, whereas bisected asialo/agalacto‐glycopeptide could not serve as an acceptor. We propose that the enzyme functions in the synthesis of core α1→3‐fucosylated complex‐type glycans in L. stagnalis. Core α1→3‐fucosylation of the asparagine‐linked GlcNAc of plant‐ and insect‐derived glycoproteins is often associated with the allergenicity of such glycoproteins. Since allergic reactions have been reported after consumption of snails, the demonstration of core α1→3‐fucosylation in L. stagnalis may be clinically relevant.
Lessons for program design from the PMM projects
Authors: Maine D
Published: July 2002

The Prevention of Maternal Mortality (PMM) Network designed and tested projects for reducing maternal deaths. The focus was on improving the availability, quality and utilization of emergency obstetric care (EmOC) for women with serious complications. Teams' projects included interventions in health facilities (to improve skills and services and reduce delays in treatment) and in communities (to address lack of transport, funds and information concerning obstetric complications). The teams' results, reported in this volume, offer several lessons for program planners. Despite difficult conditions in the project countries, the teams demonstrated that it is almost always possible to make improvements in the delivery of EmOC. Their work shows that EmOC can be improved not only by concentrating on hospitals and physicians, but also by focusing on peripheral facilities and other qualified staff. The teams' findings regarding utilization of EmOC suggest that more people utilize services when they know them to be functioning well. Community efforts, including education and mobilization, have a role to play in improving utilization once services are in place. Improving EmOC need not be costly, because in many areas the necessary facilities exist and staff are already in place. © 1997 International Federation of Gynecology and Obstetrics
Energy metabolism and its linkage to intracellular Ca2+ and pH regulation in rat spermatogenic cells
Authors: Herrera Estefania , Salas Karime , Lagos Nestor , Benos Dale J. , Reyes Juan G.
Published: July 2002

Energy metabolism and intracellular adenine nucleotides of meiotic and postmeiotic spermatogenic cells are highly dependent on external substrates for oxidative phosphorylation and glycolysis. Using fluorescent probes to measure the changes in cytosolic [Ca2+] ([Ca2+]i) and pH (pHi), we were able to demonstrate that changes in energy metabolism of meiotic and postmeiotic spermatogenic cells were rapidly translated into changes of pHi and [Ca2+]i in the absence or presence of external Ca2+. Under these conditions, mitochondria were gaining cytosolic calcium in these cells. Our results indicate that Ca2+ mobilised by changes in metabolic energy pathways originated in thapsigargin‐sensitive intracellular Ca2+ stores. Changes in intracellular adenine nucleotides, measured by HPLC, and a likely colocalization of ATP‐producing and ATP‐consuming processes in the cells seemed to provide the linkage between metabolic fluxes and the changes in pHi and [Ca2+]i in pachytene spermatocytes and round spermatids. Glucose metabolism produced an increase of [Ca2+]i in round spermatids but not in pachytene spermatocytes, and a decrease in pHi in both cell types. Hence, glucose emerges as a molecule that can differentially modulate [Ca2+]i and pHi in pachytene spermatocytes and round spermatids in rats.
The effect of surgical dissections on blood flow to the tibial tubercle
Authors: Kanamiya Takeshi , Naito Masatoshi , Ikari Nobuhiro , Hara Michiya
Published: July 2002

Tibial tubercle transfer is often used for the treatment of patella maltracking. Because the periosteum of both sides of the tibia is stripped off along the tibial tubercle and then the bilateral cortices are transferred, this procedure may disturb the blood supply to the tibial tubercle. However, the blood supply to the tibial tubercle has not yet been clearly elucidated. The purpose of this study is to investigate the effect of surgical dissection on blood flow to the tibial tubercle in an animal model using a hydrogen washout technique. Eleven knees of nine mongrel dogs weighing from 7.0 to 19.1 kg were utilized. The blood flow was measured using a hydrogen washout technique. Before performing the surgical procedures, the control blood flow rate of the tibial tubercle averaged 19.6 ml/min per 100 g of tissue. The blood flow rate did not significantly decrease after transecting the periosteum on the lateral side of the tibia alone (P > 0.05). After completing the tibial tubercle osteotomy, the blood flow rate averaged 11.5 ml/min per 100 g of tissue, which is a 25.3% decrease as compared with the value after transecting the periosteum on the lateral side of the tibia alone (P < 0.05). The blood flow rate significantly decreased to 3.4 ml/min per 100 g of tissue after the distal periosteal transection and osteotomy of the distal cortex of the tibial tubercle (P < 0.05). The addition of a medial periosteal transection caused a complete arrest of the blood flow in 10 out of 11 knees, or a 91.2% decrease as compared with the value after a distal periosteal transection and osteotomy of the distal cortex of the tibial tubercle (P < 0.05). © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Activation of oncogenic pathways in degenerating neurons in Alzheimer disease
Authors: Zhu Xiongwei , Raina Arun K. , Boux Heather , Simmons Zachary L. , Takeda Atsushi , Smith Mark A.
Published: July 2002

A number of recent findings have highlighted the similarities between neurogenesis during development and neurodegeneration during Alzheimer disease. In fact, neuronal populations that are known to degenerate in Alzheimer disease exhibit phenotypic changes characteristic of cells re‐entering the cell division cycle. In this study, we extended these findings by investigating components of the cell cycle, known to trigger progression through G1 through activation of signal transduction cascades. Specifically, we found that proteins implicated in G1 transition, namely Cdc42/Rac, are upregulated in select neuronal populations in cases of Alzheimer disease in comparison to age‐matched controls. Importantly, Cdc42/Rac shows considerable overlap with early cytoskeletal abnormalities suggesting that these changes are an extremely proximal event in the pathogenesis of the disease. Given the functional role of Cdc42/Rac in various cellular processes known to be perturbed in Alzheimer disease, namely cytoskeletal organization, oxidative balance, and oncogenic signaling, it is likely that increased neuronal Cdc42/Rac is highly significant in relation to the pathogenic process and contributes to neuronal degeneration. In fact, these findings suggest that Alzheimer disease is an oncogenic process.
An animal model for the study of the genetic bases of behaviour in men: the multiple marker strains (MMS)
Authors: Clément Y. , Lepicard E. , Chapouthier G.
Published: July 2002

Animal models are often used for preclinical research on the neurobiology of psychiatric disorders. Whereas many are employed to screen new therapeutic agents, few of them are used to study the genetic bases of psychiatric diseases, probably because of the complex genetic determinism underlying quantitative behavioral traits such as mood, personality or intelligence. The present article presents a short review introducing an analysis model using mi the marker strains model. Using this model it is possible both to display genetic determinism data and to locate some of the chromosomal fragments involved in the regulation of anxiogenic processes. At present it cannot accurately determine the position of one or more genes, but it does provide a valuable means of ‘scanning’ the genome for an approximation. Through genetic analysis, using the model, an attempt will be made to identify autosomal fragments which may be involved in two behavioural traits: anxiety and chemical-induced seizures. In this paper, after reviewing theoretical aspects of looking for genes involved in behaviour, we will successively introduce studies in genetic topics in psychiatric human studies as well as appropriated behavioural animal studies. Then we will present a genetic model in mice which allows us to locate chromosomal fragments associated with a behavioural trait: multiple marker strains.
Predictive factors of chronic Post-Traumatic Stress Disorder in rape victims
Authors: Darves-Bornoz JM , Lépine JP , Choquet M , Berger C , Degiovanni A , Gaillard P
Published: July 2002

This study aimed to investigate the psychological disorders following rape as well as the course of Post-Traumatic Stress Disorder (PTSD), and to determine clinical factors predictive of chronic PTSD. Seventy-three rape victims were observed in a systematic follow-up study over 1 year following rape using structured interview schedules. The frequency of PTSD was massive. The early disorders predicting PTSD 1 year after rape included somatoform and dissociative disorders, agoraphobia and specific phobias as well as depressive and gender identity disorders and alcohol abuse. Through stepwise logistic regressions, the following were found to be good models of prediction of chronic PTSD 1 year after rape: for the characteristics of the traumas, intrafamily rape, being physically assaulted outside rape, and added physical violence during rape; for the early psychological and behavioural attitudes, low self-esteem, permanent feelings of emptiness and running away; and for early mental disorders, agoraphobia and depressive disorders. Finally, among all these predictive factors, added physical violence during rape, low self-esteem, permanent feelings of emptiness and agoraphobia were shown to constitute a strong model of predictors. People presenting features such as the predictive factors of chronic PTSD found in the study should be asked about a history of rape and symptoms of PTSD.
Studies of political elites in Russia: issues and alternatives☆
Authors: Gel’man Vladimir , Tarusina Inessa
Published: July 2002

Studies of political elites have emerged rapidly in post-Communist Russia. This state-of-theart article reflects on various developments in the field, analyzes research projects and frameworks, and focuses on two major issues of elite research: stratification studies and transition studies. The formation of an academic community in this field is close to completion. Russian scholars commonly accept different theoretical and methodological approaches from those employed by Western social scientists, but the lack of value-free work and comparative studies makes Russian studies of political elites somewhat isolated from the mainstream of social research.
Two Models of In‐Service Training to Improve Midwifery Skills: How Well do They Work?
Authors: McDermott Jeanne , Beck Diana , Buffington Sandra Tebben , Annas Janne , Supratikto Gunawan , Prenggono Darwin , Ekonomi Dra. M. F. Sri , Achadi Endang
Published: July 2002

This program evaluation compared the knowledge, confidence, and skills of Indonesian village midwives who attended an intensive in‐service training with midwives who received an internship program and midwives who attended no program. The five key skills compared were prevention of infection, use of the partograph, manual removal of placenta, bimanual uterine compression, and neonatal resuscitation. Midwives from the intensive in‐service that combined competency–based skill training with peer review and continuing education scored higher on the knowledge test and demonstration of the five key skills and reported managing complications better than mid‐wives who attended no training program. Midwives from the internship program scored intermediate between the intensively trained and the untrained midwives. Overall, skill scores were 71% for midwives in the intensive program, 62% for the interns, and 51% for midwives with no in‐service training. Village midwives from the intensive program scored significantly higher in the practical demonstration of manual removal of placenta, bimanual compression, and neonatal resuscitation than the interns, but the scores on infection prevention and use of the partograph were not different between the two groups. Differences in the volume of training opportunities between the two programs could be responsible for the different outcomes.
Sampled‐data filter design for large‐scale interconnected systems with sensor fault and missing measurements
Authors: Sakthivel Rathinasamy , Sweetha Senthilrathnam , Tharanidharan Vasudevan , Harshavarthini Shanmugam
Published: January 2021

This article focuses on a decentralized sampled‐data filter design for a class of large‐scale interconnected systems. Precisely in the addressed system, the inevitable factors such as missing measurements, time‐varying delays, randomly occurring uncertainties, and impulsive effects are taken into consideration. Also, we incorporated the gain perturbations and sensor faults in the proposed filter design. Furthermore, a new set of sufficient criterion has been derived by choosing an appropriate Lyapunov‐Krasovskii functional that ensures the asymptotic stability of the resulting augmented filtering error system with the prescribed mixed H∞ and passive performance index. Specifically, the corresponding filter gain matrices are derived by solving the developed sufficient criterion formulated in terms of linear matrix inequalities. The effectiveness of the proposed filter design technique are then exemplified by two numerical examples with simulations.
Dislocation Density–Based Model and Stacked Auto‐Encoder Model for Ti‐55511 Alloy with Basket‐Weave Microstructures Deformed in α + β Region
Authors: Pang Guo-Dong , Lin Yong-Cheng , Qiu Yu-Liang , Jiang Yu-Qiang , Xiao Yi-Wei , Chen Ming-Song
Published: January 2021

The flow behaviors of Ti‐55511 alloy with basket‐weave microstructures are investigated during the hot compression in α + β region. It is observed that the flow behaviors are visibly influenced by the deformation temperature and strain rates. The primary softening mechanisms are the dynamic recovery of β grains and the spheroidization of lamellar α phases. Meanwhile, a dislocation density–based model and a stacked auto‐encoder (SAE) model are built to reveal the flow behaviors of the studied alloy. The relationship between the evolution of dislocation density and the hardening/softening mechanisms are considered in the dislocation density–based model, with the correlation coefficient being 0.9957. The structures of the established SAE model based on the intelligence algorithm are confirmed layer by layer. The SAE model has a high prediction accuracy when the number of hidden layers is 3, and the nodes of three hidden layers are 15, 40, and 35, respectively. It can demonstrate the nonlinear relationship between the flow stress and deformation parameters.
Modulating the Bioactivity of Mucin Hydrogels with Crosslinking Architecture
Authors: Jiang Kun , Yan Hongji , Rickert Carolin , Marczynski Matthias , Sixtensson Kajsa , Vilaplana Francisco , Lieleg Oliver , Crouzier Thomas
Published: January 2021

Hydrogels made of crosslinked macromolecules used in regenerative medicine technologies can be designed to affect the fate of surrounding cells and tissues in defined ways. Their function typically depends on the type and number of bioactive moieties such as receptor ligands present in the hydrogel. However, the detail in how such moieties are presented to cells can also be instrumental. In this work, how the crosslinking architecture of a hydrogel can affect its bioactivity is explored. It is shown that bovine submaxillary mucins, a highly glycosylated and immune‐modulating protein, exhibit strikingly different bioactivities whether they are crosslinked through their glycans or their protein domains. Both the susceptibility to enzymatic degradation and macrophage response are affected, while rheological properties and barrier to diffusion are mostly unaffected. The results suggest that crosslinking architecture affects the accessibility of the substrate to proteases and the pattern of sialic acid residues exposed to the macrophages. Thus, modulating the accessibility of binding sites through the choice of the crosslinking strategy appears as a useful parameter to tune the bioactivity of hydrogel‐based systems.
A Virus‐Mimicking Nucleic Acid Nanogel Reprograms Microglia and Macrophages for Glioblastoma Therapy
Authors: Gao Xihui , Li Sha , Ding Fei , Liu Xinlong , Wu Yijing , Li Jing , Feng Jing , Zhu Xinyuan , Zhang Chuan
Published: January 2021

Immunotherapy is recognized as one of the most promising approaches to treat cancers. However, its effect in glioblastoma (GBM) treatment is insufficient, which can in part be attributed to the immunosuppressive tumor microenvironment (TME). Microglia and macrophages are the main immune infiltrating cells in the TME of GBM. Unfortunately, instead of initiating the anti‐tumor response, GBM‐infiltrating microglia and macrophages switch to a tumor‐promoting phenotype (M2), and support tumor growth, angiogenesis, and immunosuppression by the release of cytokines. In this work, a virus‐mimicking membrane‐coated nucleic acid nanogel Vir‐Gel embedded with therapeutic miRNA is developed, which can reprogram microglia and macrophages from a pro‐invasive M2 phenotype to an anti‐tumor M1 phenotype. By mimicking the virus infection process, Vir‐Gel significantly enhances the targetability and cell uptake efficiency of the miR155‐bearing nucleic acid nanogel. In vivo evaluations demonstrate that Vir‐Gel apparently prolongs the circulation lifetime of miR155 and endows it with an active tumor‐targeting capability and excellent tumor inhibition efficacy. Owing to its noninvasive feature and effective delivery capability, the virus‐mimicking nucleic acid nanogel provides a general and convenient platform that can successfully treat a wide range of diseases.
Advances in Nanostructures for High‐Performance Triboelectric Nanogenerators
Authors: Zou Yongjiu , Xu Jing , Chen Kyle , Chen Jun
Published: January 2021

With the rapid development of the Internet of Things (IoT) and the ongoing Fourth Industrial Revolution, the effective conversion of wasted ambient mechanical energy from the environment to generate electricity is regarded as one of the most pivotal technologies for powering widely distributed electronics in the era of the Internet of Things. Although the triboelectric nanogenerator (TENG), based on the coupling effect of contact electrification and electrostatic induction, has recently undergone a tremendous evolution with the development of various features such as flexibility, conformability, and user‐friendliness, further improvement of the output performance is still required for usage toward practical applications for the next‐generation of IoT devices. In this review article, surface nanostructure modification methods for high‐performance triboelectric nanogenerators are systematically summarized. The field is deeply reviewed, with the methods classified into four categories: templating method, appending method, etching method, and crumpling method. Finally, an in‐depth discussion of the existing challenges and the direction of future efforts for enhancing TENG output performance are clearly stated, which can contribute to promoting further development of the field.