bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of iNOS expression and glutathione levels in rat liver by oxygen tension
Authors: Miralles Cristina , Busquets Xavier , Santos Carmen , Togores Bernat , Hussain Sabah , Rahman Irfan , MacNee William , Agustı́ Alvar G.N.
Published: July 2002

Molecular oxygen (O2) regulates the expression of a variety of genes. We hypothesized that O2 tension may regulate iNOS expression in rat liver through the production of reactive oxygen species (ROS) and the reduction of intracellular glutathione (GSH) levels. To investigate this hypothesis, we determined the effects of hyperoxia upon iNOS induction (both at the protein and mRNA level) and the intracellular concentration of GSH in an isolated in vitro perfused rat liver preparation. To study the potential involvement of ROS in the intracellular signaling pathway linking changes in oxygen tension to gene expression, we repeated these determinations in the presence of the thiol antioxidant N‐acetyl‐L‐cysteine (NAC). We found that 95% O2 tension caused a significant induction of the iNOS protein and mRNA levels paralleled by a significant fall in intracellular GSH concentration. The addition of NAC (1 mM) to the perfusate during hyperoxia blocked the induction of iNOS and restored GSH levels. These results indicate that molecular O2 regulates the expression of iNOS in rat liver at the transcriptional level, most likely through the production of ROS and the reduction of intracellular GSH levels.
Cross‐talk between signal transducer and activator of transcription 3 and estrogen receptor signaling
Authors: Yamamoto Tetsuya , Matsuda Tadashi , Junicho Akira , Kishi Hiroyuki , Saatcioglu Fahri , Muraguchi Atsushi
Published: July 2002

Interleukin‐6 (IL‐6) is a multifunctional cytokine that plays important roles in the immune system, hematopoiesis, and acute phase reactions. Estrogens have significant roles in a variety of biological events, such as the development and maintenance of female reproductive organs, and bone and lipid metabolism. Previous studies demonstrated that estrogens suppress IL‐6‐induced osteoporosis and the growth of multiple myeloma cells by repressing IL‐6 and IL‐6 receptor gene expression. Here we present a novel mechanism for the inhibitory effect of estrogens on IL‐6 function. IL‐6‐induced activation of signal transducer and activator of transcription 3 (STAT3) activity and STAT3‐mediated gene expression were suppressed by 17β‐estradiol (E2) in breast cancer cells. E2‐mediated inhibition of STAT3 activation was reversed by tamoxifen, an estrogen receptor (ER) antagonist. We provide evidence that the inhibitory action of ER on STAT3 activity was due to direct physical interactions between STAT3 and ER which represents a novel form of cross‐talk between STAT3 and ER signaling pathways.
The possible involvement of CXCR4 in the inhibition of HIV‐1 infection mediated by DP178/gp41
Authors: Xu Younong , Zhang Xiaoyan , Matsuoka Masao , Hattori Toshio
Published: July 2002

The N‐ (N36/DP107) and C‐terminal peptides (C34/DP178) from two α‐helical domains of human immunodeficiency virus type 1 (HIV‐1) gp41 inhibited HIV infection. A single‐round infection using pseudotyped virus clarified that a greater amount of gp41‐derived peptides was necessary for the inhibition of R5 virus (ADA) infection than for that of X4 virus (LAI) infection. Furthermore, R5X4 virus (89.6) infection via CCR5 needs more peptides for inhibition than its infection via CXCR4 does. A high sensitivity of X4 virus was partially ascribed to the inhibition of the 12G5 binding to CXCR4 by DP178LAI.
Aspirin promotes TFF2 gene activation in human gastric cancer cell lines
Authors: Azarschab Pia , Al-Azzeh Ezzal-din , Kornberger Wolfgang , Gött Peter
Published: July 2002

Trefoil factor family (TFF) peptides promote cell migration, heal the mucosa and may suppress tumor growth. In reporter gene assays we show that aspirin (1–12 mM) evokes a six‐fold up‐regulation of TFF2, but not TFF1 and TFF3 transcription in human gastrointestinal cell lines. 6 h after application up‐regulation of endogenous TFF2 mRNA was observed. TFF2 transcription was enhanced by indomethacin and arachidonic acid but repressed by staurosporine, suggesting mediation via protein kinase C. We mapped an aspirin responding element −546 to −758 bp upstream of TFF2. Up‐regulation of TFF2 by aspirin may partially explain the chemopreventive potential of low dose aspirin in gastrointestinal carcinogenesis.
The adaptive regulation of amino acid transport system A is associated to changes in ATA2 expression
Authors: Franchi Gazzola Renata , Sala Roberto , Bussolati Ovidio , Visigalli Rossana , Dall'Asta Valeria , Ganapathy Vadivel , Gazzola Gian C.
Published: July 2002

The activity of transport system A for neutral amino acids is adaptively stimulated upon amino acid starvation. In cultured human fibroblasts this treatment causes an increase in the expression of the ATA2 system A transporter gene. ATA2 mRNA increase and transport stimulation are suppressed by system A substrates, but they are unaffected by other amino acids. Supplementation of amino acid‐starved cells with substrates of system A causes a decrease in both ATA2 mRNA and system A transport activity. These results suggest a direct relationship between ATA2 expression and system A transport activity.
Nuclear localization of protein phosphatase 5 is dependent on the carboxy‐terminal region
Authors: Borthwick Emma B , Zeke Tamás , Prescott Alan R , Cohen Patricia T.W
Published: July 2002

Endogenous and overexpressed protein phosphatase 5 (PP5) localizes to the nucleus and cytoplasm of HeLa cells, while the overexpressed TPR domain of PP5 is restricted to the cytoplasm. Deletion and mutational analysis of human PP5 demonstrates that the C‐terminal amino acids 420–499 are essential for nuclear localization and PP5 activity is not required. Since the phosphatase domain terminates at 473, these studies suggest that the highly conserved section (476–491) with the eukaryotic consensus FXAVPHPXΦXPMAYAN is required for nuclear localization of PP5. Bacterially expressed PP5 is inhibited by several tumor promoters but not by the anticancer drug fostriecin.
Cross‐talk between IL‐6 and TGF‐β signaling in hepatoma cells
Authors: Yamamoto Tetsuya , Matsuda Tadashi , Muraguchi Atsushi , Miyazono Kohei , Kawabata Masahiro
Published: July 2002

Interleukin‐6 (IL‐6) is a multifunctional cytokine that plays important roles in the immune system, hematopoiesis, and acute phase reactions. Transforming growth factor‐β (TGF‐β) also has pleiotropy including the production of acute phase proteins in hepatocytes. To elucidate the cross‐talk between IL‐6 and TGF‐β signaling pathways in hepatic cells, we investigated the effects of TGF‐β on IL‐6‐induced signal transducer and activator of transcription‐3 (STAT3) activation in a human hepatoma cell line, Hep3B. IL‐6‐induced activation of STAT3 activity and STAT3‐mediated gene expression were augmented by TGF‐β in Hep3B cells. We provide evidence that these activities were due to physical interactions between STAT3 and Sma‐ and MAD‐related protein‐3, bridged by p300. These results demonstrate a molecular mechanism of a cross‐talk between STAT3 and TGF‐β signaling pathways in hepatocytes.
Oxidative stress, aging and longevity in Drosophila melanogaster
Authors: Le Bourg Éric
Published: July 2002

Free radicals produced during normal metabolism cause damage to macromolecules. The free radical theory of aging proposes that the organism is unable to repair all of them and that, with time, unrepaired damages accumulate and put the organism at risk: in other words, free radicals provoke aging and death. This article reviews both the results of adding antioxidants to food on longevity in Drosophila melanogaster, as well as the studies on antioxidant enzymes (inactivation in vivo, null mutants, overexpression). It is concluded that antioxidant enzymes are probably poorly connected to the normal aging process, but they allow the organism to cope with stressful conditions.
Different effects of the Ca2+‐binding protein, KChIP1, on two Kv4 subfamily members, Kv4.1 and Kv4.2
Authors: Nakamura Tomoe Y. , Nandi Sumon , Pountney David J. , Artman Michael , Rudy Bernardo , Coetzee William A.
Published: July 2002

The Ca2+‐binding protein, K+ channel‐interacting protein 1 (KChIP1), modulates Kv4 channels. We show here that KChIP1 affects Kv4.1 and Kv4.2 currents differently. KChIP1 slows Kv4.2 inactivation but accelerates the Kv4.1 inactivation time course. Kv4.2 activation is shifted in a hyperpolarizing direction, whereas a depolarizing shift occurs for Kv4.1. On the other hand, KChIP1 increases the current amplitudes and accelerates recovery from inactivation of both currents. An involvement of the Kv4 N‐terminus in these differential effects is demonstrated using chimeras of Kv4.2 and Kv4.1. These results reveal a novel interaction of KChIP1 with these two Kv4 members. This represents a mechanism to further increase the functional diversity of K+ channels.
Enhancement of macrophage phagocytosis upon iC3b deposition on apoptotic cells
Authors: Takizawa Fumitake , Tsuji Shoutaro , Nagasawa Shigeharu
Published: July 2002

Apoptotic cells activate homologous complement and are opsonized with iC3b. We assessed the effect of iC3b opsonization upon phagocytosis of apoptotic Jurkat cells by macrophages, which were differentiated from THP‐1 cells by treatment with retinoic acid. Macrophage phagocytosis of apoptotic Jurkat cells was enhanced upon incubation of the apoptotic cells with normal human serum. The enhanced macrophage phagocytosis of normal serum‐treated apoptotic cells was decreased by anti‐human C3 F(ab′)2 and anti‐CR3 and anti‐CR4 mAbs to the level of phagocytosis of those treated with complement‐blocked serum. These results suggest that interaction between iC3b on apoptotic cells and complement receptor type 3 (CR3) and/or complement receptor type 4 (CR4) on macrophages could play an important role for the clearance of apoptotic cells by macrophages in vivo.
A β‐amyloid peptide variant related with familial Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis is poorly eliminated by cathepsin D
Authors: Hamazaki Hideaki
Published: July 2002

The cerebral deposition of 40–42 residue amyloid β‐protein (Aβ) is a characteristic of Alzheimer's disease. Cathepsin D is possibly involved in the intracellular clearance of Aβ (Hamazaki, H. (1996) FEBS Lett., in press). The present work shows that cathepsin D hydrolyzes wild‐type Aβ 20 times faster than a variant Aβ with a substitution at residue 21 from Ala to Gly. Since the substitution has been linked to familial Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis (Hendriks et al. (1992) Nature Genet. 1, 218–221), the present observations suggest that the inefficient elimination of Aβ by cathepsin D is capable of being one of causes of the amyloid fibril formation.
Maurotoxin, a four disulfide bridge toxin fromScorpio maurusvenom: purification, structure and action on potassium channels
Authors: Kharrat R , Mansuelle P , Sampieri F , Crest M , Oughideni R , Van Rietschoten J , Martin-Eauclaire M.F , Rochat H , El Ayeb M
Published: July 2002

A new toxin acting on K+channels, maurotoxin (MTX), has been purified to homogeneity from the venom of the chactoid scorpionScorpio maurus. MTX is a basic single chain 34 amino acid residue polypeptide, amidated at its C terminal, and crosslinked by four disulfide bridges. It shows 29–68% sequence identity with other K+channel toxins, and presents an original disulfide pattern, the last two half‐cystine residues (31–34) being connected. Although the first three disulfide bonds have not been defined experimentally, modelling based on the structure of charybdotoxin favored two combinations out of six, one of which has two bridges (3–24 and 9–29) in common with the general motif of scorpion toxins. The last bridge would connect residues 13 and 19. MTX inhibits the binding to rat brain synaptosomal membranes of both [125I]apamin, a SKCachannel blocker (IC505 nM), and [125I]kaliotoxin, a Kv channel blocker (IC5030 pM). MTX blocks the Kv1.1, Kv1.2 and Kv1.3 currents expressed inXenopusoocytes with IC50of 45, 0.8 and 180 nM, respectively. MTX represents a member of a new class of short toxins with 4 disulfide bridges, active on voltage‐dependent K+channel and also competing with apamin for binding to its receptor.
The neuronal nitric oxide synthase PDZ motif binds to ‐G(D,E)XV* carboxyterminal sequences
Authors: Schepens Jan , Cuppen Edwin , Wieringa Bé , Hendriks Wiljan
Published: July 2002

PDZ motifs are small protein–protein interaction modules that are thought to play a role in the clustering of submembranous signalling molecules. The specificity and functional consequences of their associative actions is still largely unknown. Using two‐hybrid methodology we here demonstrate that the PDZ motif of neuronal nitric oxide synthase (nNOS) can mediate the binding to several other proteins in brain. Peptide library screening showed that proteins bearing a carboxy‐terminal G(D,E)XV* sequence are preferred targets for the nNOS amino‐terminal PDZ motif. Potential nNOS targets include a melanoma‐associated antigen, cyclophilins and the α1C‐adrenergic receptor.
Activation of translation initiation factor eIF2B by insulin requires phosphatidyl inositol 3‐kinase
Authors: Welsh Gavin I , Stokes Christa M , Wang Xuemin , Sakaue Hiroshi , Ogawa Wataru , Kasuga Masato , Proud Christopher G
Published: July 2002

Eukaryotic initiation factor eIF2B mediates a key regulatory step in peptide‐chain initiation and is acutely activated by insulin, although it is not clear how. Inhibitors of phosphatidylinositide 3‐kinase blocked activation of eIF2B, although rapamycin, which inhibits the p70 S6 kinase pathway, did not. Furthermore, a dominant negative mutant of PI 3‐kinase also prevented activation of eIF2B, while a Sos‐mutant, which blocks MAP kinase activation, did not. The data demonstrate that a pathway distinct from MAP and p70 S6 kinases regulates eIF2B. Glycogen synthase kinase‐3 (GSK‐3) phosphorylates and inactivates eIF2B. In all cases, eIF2B and GSK‐3 were regulated reciprocally. Dominant negative PI 3‐kinase abolished the insulin‐induced inhibition of GSK‐3. These data strongly support the hypothesis that insulin activates eIF2B through a signalling pathway involving PI 3‐kinase and inhibition of GSK‐3.
Human free secretory component is composed of the first 585 amino acid residues of the polymeric immunoglobulin receptor
Authors: Hughes Graham J , Frutiger Séverine , Savoy Luc-Alain , Reason Andrew J , Morris Howard R , Jaton Jean-Claude
Published: July 2002

The main objective of this work was to unequivocally determine the C‐terminal sequence of human milk free secretory component (SC). It was found to end at arginine‐585, i.e. 33 amino acids downstream from the major heterogeneous C‐terminal residue previously identified for colostrum SC. In contrast, our data showed that the C‐terminal end of SC was found to be homogeneous. Conflicting assignments, Asp/Gln, a missing Asn‐211, Asp/Asn, Glu/Gln were corrected and found to agree with the cDNA sequence. An Ala/Val substitution at position 562 (domain VI) was identified. Its genetic significance is uncertain at present.
A novel centromere monospecific serum to a human autoepitope on the histone H3‐like protein CENP‐A
Authors: Valdivia Manuel M , Figueroa Javier , Iglesias Concepción , Ortı́z Manuela
Published: July 2002

Centromere autoantibodies are commonly found in the serum of patients with some systemic autoimmune diseases. Previous studies have shown that a major human centromere autoantigen is the histone H3‐like protein CENP‐A. Although the human cDNA has been cloned, native CENP‐A has been neither isolated nor expressed inEscherichia coli, and specific antibodies to this chromatin‐associated centromere protein are not available yet. In this report, a highly charged peptide on CENP‐A (residues 3–17) was used to generate a monospecific antibody that reacts by immunoblots with the 17 kDa centromeric protein. Immunofluorescence analysis showed reactivity of this anti‐CENP‐A serum in several but not all mammalian culture cells analyzed, suggesting that the sequence of this histone‐like centromere protein could be more variable throughout evolution than originally thought. Selective extractions of human placenta nuclear proteins and immunoblot analysis indicated that CENP‐A behaves in a similar way to the core histone polypeptides after nuclease digestion of chromatin. Also, immunoblot analysis demonstrated that the CENP‐A peptide used as immunogen is a target region on the CENP‐A molecule in several but not all CREST patients analyzed with high titers of autoantibodies to the centromere. Lastly, we found that in Jurkat cells induced to apoptosis, CENP‐A remains associated with the centromere, in contrast to other human autoantigens studied during apoptosis.
Atomic force microscopy examination of tobacco mosaic virus and virion RNA
Authors: Drygin Yuri F , Bordunova Olga A , Gallyamov Marat O , Yaminsky Igor V
Published: July 2002

Atomic force microscopy (AFM) was applied to study uncoated virus particles and RNA prepared by stripping of tobacco mosaic virions (TMV) with mild alkali or urea and dimethylsulfoxide. We found that AFM is an appropriate method to study ribonucleoprotein and free RNA structures. Images of entire tobacco mosaic virions, partially uncoated TMV particles with protruding RNA molecule from one or both ends and individual RNA molecules are presented.
Different degradation pathways for heterologous glycoproteins in yeast
Authors: Holkeri Heidi , Makarow Marja
Published: July 2002

Rat nerve growth factor receptor ectodomain (NGFRe) and Escherichia coli β‐lactamase were translocated into the yeast endoplasmic reticulum (ER), glycosylated, misfolded and rapidly degraded. NGFRe underwent ATP‐dependent thermosensitive degradation independently of vesicular transport. Since no evidence for degradation by the cytoplasmic 26S proteosome complex could be obtained, NGFRe appeared to be degraded in the ER. β‐Lactamase exited the ER by vesicular traffic and was transported from the Golgi via the Vps10 receptor pathway to the vacuole for degradation. Machineries in the ER and the Golgi appear to recognize distinct structural features on misfolded heterologous proteins and guide them to different degradation pathways.
Isolation, characterization and synthesis of a novel pardaxin isoform
Authors: Adermann Knut , Raida Manfred , Paul Yasmin , Abu-Raya Saleh , Bloch-Shilderman Eugenia , Lazarovici Philip , Hochman Jacob , Wellhöner Hans
Published: July 2002

We report the isolation of a novel pardaxin isoform from the toxic secretion of the Red Sea Moses sole (Pardachirus marmoratus). Mass spectrometrical analysis of the newly purified peptide revealed a different primary structure compared to the previously known pardaxin isoforms. Sequence analysis disclosed an aspartic acid residue instead of glycine at position 31 of the new isoform. According to the novel sequence, a synthetic Asp‐31‐peptide was compared with the native compound as well as with synthetic Gly‐31‐pardaxin. The isolated Asp‐31‐pardaxin isoform and its synthetic analog exhibited identical elution properties during reverse‐phase HPLC, as well as similar dose‐dependent lytic effects on human erythrocytes at a concentration of 10−6 to 10−5 M. The hemolytic activity of Asp‐31‐pardaxins was lower than that of Gly‐31‐pardaxin and no synergistic effect between these peptides was found. The additional negative charge introduced by Asp‐31 is likely to affect the selectivity of pardaxin pores towards a variety of ions.
Fatty acids as natural uncouplers preventing generation of O⋅−2 and H2O2 by mitochondria in the resting state
Authors: Korshunov Sergey S , Korkina Olga V , Ruuge Enno K , Skulachev Vladimir P , Starkov Anatoly A
Published: July 2002

Both natural (laurate) and artificial (m‐chlorocarbonylcyanide phenylhydrazone; CCCP) uncouplers strongly inhibit O⋅−
2 and H2O2 formation by rat heart mitochondria oxidizing succinate. Carboxyatractylate, an ATP/ADP antiporter inhibitor, abolishes the laurate inhibition, the CCCP inhibition being unaffected. Atractylate partially releases the inhibition by laurate and decelerates the releasing effect of carboxyatractylate. GDP is much less effective than carboxyatractylate in releasing the laurate inhibition of reactive oxygen species (ROS) formation. Micromolar laurate concentrations arresting the ROS formation cause strong inhibition of reverse electron transfer from succinate to NAD+, whereas State 4 respiration and the transmembrane electric potential difference (ΔΨ) level are affected only slightly. It is suggested that (i) free fatty acids operate as natural ‘mild uncouplers’ preventing the transmembrane electrochemical H+ potential difference () from being above a threshold critical for ROS formation by complex I and, to a lesser degree, by complex III of the respiratory chain, and (ii) it is the ATP/ADP‐antiporter, rather than uncoupling protein 2, that is mainly involved in this antioxidant mechanism of heart muscle mitochondria.
Dissection of the cAMP induced cytosolic calcium response in Dictyostelium discoideum: the role of cAMP receptor subtypes and G protein subunits
Authors: Sonnemann Jürgen , Aichem Annette , Schlatterer Christina
Published: July 2002

The cAMP signaling cascade leading to changes in [Ca2+]i in Dictyostelium discoideum was analyzed using cell lines overexpressing single cAMP receptor subtypes (cAR1–cAR3) or lacking the Gα2 or Gβ subunit of the G protein. Imaging of fura2‐dextran‐loaded amoebae revealed cAMP‐induced [Ca2+]i changes characteristic for each receptor subtype activated. Cells expressing distinct subtypes sort to defined zones during multicellular development suggesting involvement of the specific [Ca2+]i transients in patterning processes. Whereas generation of the [Ca2+]i increase was Gα2‐independent, only few cells devoid of Gβ displayed a [Ca2+]i change after stimulation indicating its participation in the regulation of the calcium homeostasis.
Production of a functional single chain antibody attached to the surface of a plant virus
Authors: Smolenska Lisa , Roberts Ian M , Learmonth Deanne , Porter Andrew J , Harris William J , Wilson T.Michael A , Santa Cruz Simon
Published: July 2002

A potato virus X (PVX) vector was used to express a single chain antibody fragment (scFv) against the herbicide diuron, as a fusion to the viral coat protein. The modified virus accumulated in inoculated Nicotiana clevelandii plants and assembled to give virus particles carrying the antibody fragment. Electron microscopy was used to show that virus particles from infected leaf sap were specifically trapped on grids coated with a diuron‐BSA conjugate. The results demonstrate that the PVX vector can be used as a presentation system for functional scFv.
Three receptor genes for plasminogen related growth factors in the genome of the puffer fish Fugu rubripes1
Authors: Cottage Amanda , Clark Melody , Hawker Kelvin , Umrania Yagnesh , Wheller Denis , Bishop Martin , Elgar Greg
Published: July 2002

Plasminogen related growth factors (PRGFs) and their receptors play major roles in embryogenesis, tissue regeneration and neoplasia. In order to investigate the complexity and evolution of the PRGF receptor family we have cloned and sequenced three receptors for PRGFs in the teleost fish Fugu rubripes, a model vertebrate with a compact genome. One of the receptor genes isolated encodes the orthologue of mammalian MET, whilst the other two may represent Fugu rubripes orthologues of RON and SEA. This is the first time three PRGF receptors have been identified in a single species.
Antioxidant‐mediated inhibition of the heat shock response leads to apoptosis
Authors: Gorman Adrienne M , Heavey Barry , Creagh Emma , Cotter Thomas G , Samali Afshin
Published: July 2002

We examined the hypothesis that reactive oxygen species (ROS) contribute to the induction of heat shock proteins (hsps) during stress response. Exposure of HL‐60 human myelocytic cells to 42°C induced both hsp72 and hsp27. In the presence of the antioxidant molecules pyrrolidine dithiocarbamate or 1,10‐phenanthroline induction of hsp72 and 27 was significantly decreased, while N‐acetyl‐l‐cysteine caused a slight reduction. Prevention of hsp induction was associated with heat sensitization and increased caspase activity, indicating that the cells were undergoing apoptosis. These data suggest that ROS contribute to the induction of hsps and furthermore, that hsp induction and apoptosis are mutually exclusive events within the same cell.
The diversity of the lipoxygenase family
Authors: Kuhn Hartmut , Thiele Bernd J
Published: July 2002

Lipoxygenases form a family of lipid peroxidising enzymes, which oxygenate free and esterified polyenoic fatty acids to the corresponding hydroperoxy derivatives. They are widely distributed in both the plant and animal kingdoms. During the last couple of years more and more lipoxygenase isoforms have been discovered but for most of them the biological significance remains unclear. This review attempts to classify the currently known mammalian lipoxygenase isoforms and critically reviews the concepts for their biological importance.
The jasmonate‐induced 60 kDa protein of barley exhibits N‐glycosidase activity in vivo
Authors: Dunaeva Marina , Goebel Cornelia , Wasternack Claus , Parthier Benno , Goerschen Eckart
Published: July 2002

Upon jasmonate treatment barley leaf segments express a putative ribosome‐inactivating protein (JIP60). The influence of this protein on translation in planta has been analysed by using barley plants and tobacco plants transformed with a barley cDNA encoding JIP60. In both plant systems JIP60 exhibited N‐glycosidase activity in vivo. The depurination of the 25S rRNA of tobacco and barley ribosomes led to accumulation of translationally inactive polysomes.
Tissue‐inherent fate of GPI revealed by GPI‐anchored GFP transgenesis
Authors: Kondoh Gen , Gao Xing-Hua , Nakano Yuka , Koike Hiroko , Yamada Shuichi , Okabe Masaru , Takeda Junji
Published: July 2002

To clarify the fate of glycosylphosphatidylinositol (GPI) in mammals, we developed GPI‐anchored enhanced green fluorescent protein (EGFP‐GPI) and transgenic mice carrying this fusion construct. When it was introduced to culture cells, the EGFP‐GPI protein was correctly sorted to plasma membranes and microsomes depending on GPI biosynthesis. Transgenic mice carrying EGFP‐GPI were found to show a broad transgene expression. Histologically, a prominent polarized localization of EGFP‐GPI protein was observed in various epithelia, the nervous system and liver and secreted from some exocrine glands, as well as non‐polarized presence in non‐epithelial tissues, demonstrating a tissue‐inherent manner of GPI sorting.
The unique N‐terminal domain of the cAMP phosphodiesterase PDE4D4 allows for interaction with specific SH3 domains
Authors: Beard Matthew B. , O'Connell Jonathan C. , Bolger Graeme B. , Houslay Miles D.
Published: July 2002

Of the five PDE4D isoenzymes, only the PDE4D4 cAMP specific phosphodiesterase was able to bind to SH3 domains. Only PDE4D4 and PDE4A5, but not any other PDE4A, B, C and D isoforms expressed in rat brain, bound to src, lyn and fyn kinase SH3 domains. Purified PDE4D4 could bind to purified lyn SH3. PDE4D4 and PDE4A5 both exhibited selectivity for binding the SH3 domains of certain proteins. PDE4D4 did not bind to WW domains. We suggest that an important function of the unique N‐terminal region of PDE4D4 may be to allow for association with certain SH3 domain‐containing proteins.
Dexamethasone in the post‐partum treatment of HELLP syndrome
Authors: Vigil‐De Gracia P , Garcı́a‐Cáceres E
Published: July 2002

Objective: To determine if the routine initiation of dexamethasone in patients with post‐partum HELLP syndrome produces therapeutic benefits. Method: The puerperal courses of 17 mothers who initially received dexamethasone after delivery were compared to 17 other mothers with HELLP syndrome who received no corticosteroids during the puerperium course. Treated patients immediately received 10 mg of dexamethasone post‐partum (intravenously) followed 12 h later by 10 mg and 10 mg at 24 h post‐partum, to a total of 30 mg. Results: The steroid treated group had significant changes over time in platelet count. Relative to the control group the platelet count increased significantly by 30 h post‐partum (P<0.01). The blood pressure, urinary output, lactic dehydrogenase, aspartato aminotransferase and alanine aminotransferase values were not significantly different between the dexamethasone and control group at any time by 72 h post‐partum. Conclusion: Parturients with HELLP syndrome who received a short course of post‐partum dexamethasone therapy had an accelerated recovery from their platelet count, but not from their liver enzymes and blood pressure.
Improving adolescent sexual behavior: a tool for better fertility outcome and safe motherhood
Authors: Creatsas G.
Published: July 2002

The consequences of increased adolescent sexuality worldwide include: an increased rate of adolescent pregnancies and abortions; a high prevalence of sexually transmitted diseases; and a significant number of psychosocial problems. Improvement of adolescent sexual behavior should be one of the primary goals of the 21st century. This includes development of new contraception techniques, providing protection from sexually transmitted diseases, improvement of contraception compliance and the correct use of mass media. As adolescents seek advice on sexual matters, it is our responsibility to provide them with accurate consultation as well as free family planning services in well organized adolescent units, where they may be counselled on the prevention of unwanted pregnancy, and sexually transmitted diseases. This will assist in a better fertility outcome and a safe motherhood.
Quantitative analysis, by ultrastructural in situ hybridization, of mitochondrial genomes and their expression in mid‐gut and ovarian cells of a mutant strain ofDrosophila subobscura
Authors: Lécher Pierre , Petit Nathalie , Le Goff Samuel , Alziari Serge
Published: July 2002

In the mitochondrial deletion mutant strain studied here, two types of DNA coexist (heteroplasmy): intact mtDNA (15.9 kb) and mutant mtDNA (10.9 kb), which represents about 80% of the mitochondrial genomes in somatic tissues. The heteroplasmy level is lower in ovary (63%). Mutation is transmitted unchanged through generations. Quantitative analysis of in situ DNA hybridization demonstrated that for the 12SrDNA probe, of a gene outside the deletion, the mitochondrial DNA cellular content in the studied cells of the mutant strain is 1.5 times higher than in the wild‐type strain. For the probe encoding Cyto b, a mitochondrial gene affected by the mutation, the ratios (mutant versus wild‐type content) differ according to cell type: close to 0.4 in MGE cells and 0.7 in ovary cells. These values indicate heteroplasmic levels of about 72% in MGE cells and 50% in stage 10 oocytes, which is lower than that previously reported for stage 14 oocytes (60%) and embryos (69%). Analysis of in situ RNA hybridization showed that for the 12SrDNA probe, the transcript concentrations do not differ significantly between MGE cells and cells of germinal origin from the two strains. For the Cyto b probe, the mutant RNA/wild‐type RNA ratios are lower in somatic cells than in stage 10 nurse cells and oocytes, but in each case less than expected. These studies indicate that the progressive heteroplasmy increase may be related to intense phases of mitochondria biogenesis and that different compensatory phenomena may exist.
Ischemia causes muscle fatigue
Authors: Murthy Gita , Hargens Alan R. , Lehman Steve , Rempel David M.
Published: July 2002

The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 ± 9.8 mm Hg) and systolic (106 ± 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3‐‐5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 ± 1.2% (SEM), 96 ± 1.9%, 93 ± 2.8%, 90 ± 2.5%, and 86 ± 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 ± 0.7% (SEM), 96 ± 2.7%, 93 ± 3.1%, 88 ± 3.2%, and 86 ± 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P < 0.05) than baseline value. Reduced twitch force was correlated in a dose‐dependent manner with reduced muscle oxygenation (r = 0.78, P < 0.001). Although the correlation does not prove causation, the results indicate that ischemia leading to a 7% or greater reduction in muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
A decreased subchondral trabecular bone tissue elastic modulus is associated with pre‐arthritic cartilage damage
Authors: Day J. S. , Ding M. , van der Linden J. C. , Hvid I. , Sumner D. R. , Weinans H.
Published: July 2002

In osteoarthritis, one postulate is that changes in the mechanical properties of the subchondral bone layer result in cartilage damage. The goal of this study was to examine changes in subchondral trabecular bone properties at the calcified tissue level in the early stages of cartilage damage. Finite element models were constructed from microCT scans of trabecular bone from the proximal tibia of donors with mild cartilage damage and from normal donors. In the donors with cartilage damage, macroscopic damage was present only in the medial compartment. The effective tissue elastic moduli were determined using a combination of finite element models and mechanical testing. The bone tissue modulus was reduced by 60% in the medial condyle of the cases with cartilage damage compared to the control specimens. Neither the presence of cartilage damage nor the anatomic site (medial vs. lateral) affected the elastic modulus at the apparent level. The volume fraction of trabecular bone was higher in the medial compartment compared to the lateral compartment of tibiae with cartilage damage (but not the controls), suggesting that mechanical properties were preserved in part at the apparent level by an increase in the bone volume fraction. It seems likely that the normal equilibrium between cartilage properties, bone tissue properties and bone volume fraction is disrupted early in the development of osteoarthritis. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
P300 event-related brain potential and personality in depression
Authors: Hansenne M. , Pitchot W. , Pinto E. , Reggers J , Papart P. , Ansseau M.
Published: July 2002

summary

P300 is an event-related brain potential (ERP) particularly interesting to the study of cognitive processes in normal subjects and in psychopathology. P300 has been applied in depression with controversial results. A major source for these controversial results could result from the diversity of depressed patients included in the different studies. Supporting this assumption, impulsivity, blunted affect, suicidal behavior and psychotic features significantly influence P300 amplitude. However, no data are available on the possible influences of the personality of depressed patients on P300. Since personality is related to P300 in normal subjects, the aim of the present study is to investigate the relationship between ERPs (P200, N200, and P300) and the Temperament and Character Inventory (TCI) in 54 depressed patients. The main results of the study concern the absence of major correlations between personality dimensions as assessed by the TCI and ERP parameters among depressed patients. Only weak partial positive correlations relate N200 latency with harm avoidance, and P300 amplitude (Pz) with the self-directedness dimension. N200 amplitude is also negatively correlated to persistence. However, the preliminary nature of the presented results with respect to the weak statistical significance should be underlined.
Measures of anhedonia and hedonic responses to sucrose in depressive and schizophrenic patients in comparison with healthy subjects
Authors: Berlin I , Givry-Steiner L , Lecrubier Y , Puech AJ
Published: July 2002

Anhedonia may be considered as a transnosological feature of depression and schizophrenia. The aim of the present study was to assess hedonic responses to sucrose solutions and sweet taste perception threshold in patients with major depression and in schizophrenic patients in comparison with healthy subjects (matched for age and gender with depressive patients), and to compare these responses to evaluations by the Physical and Social Anhedonia scale of Chapman and the Pleasure Scale of Fawcett, generally used to quantify anhedonia. Hedonic responses to sucrose solutions were similar in patients with major depression (n = 20), schizophrenia (n = 20), and healthy controls (n = 20). Sweet taste perception threshold was significantly higher in depressive patients than in controls. Hedonic response to sucrose was inversely correlated with physical Anhedonia Scores and sweet taste perception threshold with Pleasure Scale scores. Measures of hedonia/anhedonia were not related with the intensity of depression or anxiety as measured by the Montgomery-Asberg Depression Rating Scale (MADRS) and Hamilton Anxiety Scale, respectively. In 11 depressed patients hospitalised for 17 to 33 days, neither hedonic ratings to sucrose solutions, sweet taste perception threshold, Physical, Social Anhedonia scores nor Pleasure Scale scores were modified in spite of substantial decrease in MADRS or Hamilton Anxiety scores. Hedonic responses to sucrose solutions and sweet taste perception threshold may be used as complementary evaluation to quantify anhedonia.
Comparison of the diagnosis of melancholic and atypical features according to DSM-IV and somatic syndrome according to ICD-10 in patients suffering from major depression
Authors: Fountoulakis K.N. , Iacovides A. , Nimatoudis I. , Kaprinis G. , Ierodiakonou Ch.
Published: July 2002

While melancholic (according to DSM) or somatic syndrome (according to ICD) has strong historical roots and substantial empirical verification, the concept of atypical features is relatively new and not sufficiently studied. The aim of the current study was to investigate the reliability of these diagnostic subcategories in patients suffering from major depression in Greece. Forty patients (eight males and 32 females) aged 19-60 years (mean 39.3, sd 12.2) suffering from major depression according to DSM-IV criteria were studied. SCAN v.2.0 was used to assess symptomatology. The presence of each criterion according to DSM-IV and ICD-10 was registered. Frequency tables were developed and factor and cluster analysis were performed. The results of the analysis suggest the existence of three syndromes which roughly reflect the melancholic and atypical but also propose a third, which can be considered as an ‘undifferentiated’ syndrome. The DSM demand that the existence of melancholic features be excluded first and then that diagnosis of atypical features be made was confirmed.
Social adjustment and self-esteem in remitted patients with mood disorders
Authors: Serretti A , Cavallini MC , Macciardi F , Namia C , Franchini L , Souery D , Lipp O , Bauwens F , Smeraldi E , Mendlewicz J
Published: July 2002

Mood disorders are characterized by manic and depressive episodes alternating with normal mood. While social function is heavily impaired during episodes of illness, there are conflicting opinions about inter-episode function. The present paper focuses on self-esteem and social adjustment in remitted mood disorders patients.

Patients with mood disorders (99 bipolar and 86 major depressive subjects, in remission) were compared with a group of 100 control subjects. The self-esteem scale (SES) and the social adjustment scale (SAS) were used to measure self-esteem and social adjustment, respectively, in both groups of subjects.

Patients with mood disorder exhibited worse social adjustment and lower self-esteem than control subjects.These results strongly confirm previous observations of poor inter-episode function in patients with mood disorder.
Prevalence and aetiology of heart failure in an Arab population
Authors: Agarwal A.K. , Venugopalan P. , de Bono D.
Published: July 2002

Background:

The epidemiology of heart failure in Arabia, with a population different from the West in cultural and ethnic origin, has not been studied before.

Aims:

To determine the prevalence and aetiologies of symptomatic heart failure in an indigenous Arab population over a 3‐year period.

Methods:

All patients with heart failure ≥ 13 years of age, treated at the only secondary care hospital of the Dhakliya region of Oman between 1992 and 1994 were evaluated prospectively by clinical history and physical examination. Chest radiograph and echo‐Doppler studies were used to confirm the diagnosis of heart failure. Exercise stress testing and/or coronary angiography were also performed in patients > 30 years of age, or earlier if ischaemic heart disease was suspected.

Results:

A total of 1164 patients were identified giving a prevalence of 5.17/1000 population during the study period (6.04/1000 among males and 4.21/1000 among females; P < 0.001). The prevalence increased with age from 1.05 / 1000 in age group < 45 years to 15.7/1000 in 45–64 years (P < 0.001) and 25.2 / 1000 in ≥ 65 years (P < 0.001). Common causes of heart failure were ischaemic heart disease (51.7%), hypertensive heart disease (24.9%) and idiopathic dilated cardiomyopathy (8.3%). Valvular heart disease and lung diseases causing heart failure were less common.

Conclusion:

The prevalence of symptomatic heart failure was appreciably significant in the population studied, showed a male preponderance and was frequent in people aged ≥ 45 years. Ischaemic heart disease and hypertension were the commonest aetiologies but idiopathic dilated cardiomyopathy was also present in a significant number of patients being relatively more prevalent than reported from the West.
Dietary and blood antioxidants in patients with chronic heart failure. Insights into the potential importance of selenium in heart failure
Authors: de Lorgeril Michel , Salen Patricia , Accominotti Michèle , Cadau Monique , Steghens Jean‐Paul , Boucher François , de Leiris Joël
Published: July 2002

Background:

Chronic heart failure (CHF) seems to be associated with increased oxidative stress. However, the hypothesis that antioxidant nutrients may contribute to the clinical severity of the disease has never been investigated.

Aims:

To examine whether antioxidant nutrients influence the exercise capacity and left ventricular function in patients with CHF.

Methods:

Dietary intake and blood levels of major antioxidant nutrients were evaluated in 21 consecutive CHF patients and in healthy age‐ and sex‐matched controls. Two indexes of the severity of CHF, peak exercise oxygen consumption (peak VO2) and left ventricular ejection fraction (LVEF), were measured and their relations with antioxidants were analysed.

Results:

Whereas plasma alpha‐tocopherol and retinol were in the normal range, vitamin C (P‐0.005) and beta‐carotene (P‐0.01) were lower in CHF. However, there was no significant association between vitamins and either peak VO2 or LVEF. Dietary intake (P<0.05) and blood levels of selenium (P<0.0005) were lower in CHF. Peak VO2 (but not LVEF) was strongly correlated with blood selenium: r‐0.76 by univariate analysis (polynomial regression) and r‐0.87 (P<0.0005) after adjustment for age, sex and LVEF.

Conclusions:

Antioxidant defences are altered in patients with CHF. Selenium may play a role in the clinical severity of the disease, rather than in the degree of left ventricular dysfunction. Further studies are warranted to confirm the data in a large sample size and to investigate the mechanisms by which selenium and other antioxidant nutrients are involved in CHF.
Mn2+/Yb3+ Codoped CsPbCl3 Perovskite Nanocrystals with Triple‐Wavelength Emission for Luminescent Solar Concentrators
Authors: Cai Tong , Wang Junyu , Li Wenhao , Hills‐Kimball Katie , Yang Hanjun , Nagaoka Yasutaka , Yuan Yucheng , Zia Rashid , Chen Ou
Published: July 2020

Doping metal ions into lead halide perovskite nanocrystals (NCs) has attracted great attention over the past few years due to the emergence of novel properties relevant to optoelectronic applications. Here, the synthesis of Mn2+/Yb3+ codoped CsPbCl3 NCs through a hot‐injection technique is reported. The resulting NCs show a unique triple‐wavelength emission covering ultraviolet/blue, visible, and near‐infrared regions. By optimizing the dopant concentrations, the total photoluminescence quantum yield (PL QY) of the codoped NCs can reach ≈125.3% due to quantum cutting effects. Mechanism studies reveal the efficient energy transfer processes from host NCs to Mn2+ and Yb3+ dopant ions, as well as a possible inter‐dopant energy transfer from Mn2+ to Yb3+ ion centers. Owing to the high PL QYs and minimal reabsorption loss, the codoped perovskite NCs are demonstrated to be used as efficient emitters in luminescent solar concentrators, with greatly enhanced external optical efficiency compared to that of using solely Mn2+ doped CsPbCl3 NCs. This study presents a new model system for enriching doping chemistry studies and future applications of perovskite NCs.
Why Biomass Residue Is Not as Plentiful as It Looks: Case Study on Economic Supply of Logging Residues
Authors: Swinton Scott M. , Dulys Felix , Klammer Sarah S.H.
Published: July 2020

Biomass inventories and techno‐economic supply studies tend to overestimate economic supply of crop and timber residues, because they ignore human decisions on whether to permit residue removal. By combining information about biophysical availability, production and delivery costs, and the willingness of different types of decision maker to permit removal of logging residues, we develop a realistic prediction of economic supply that becomes very price inelastic. Because managers of only 52% of Michigan and Wisconsin forestland studied would allow the removal of logging residues, we conclude that most forecasts overestimate residue biomass supply by 50 to 100%.
Visible‐Light‐Driven Remote C−H Chlorination of Aliphatic Sulfonamides with Sodium Hypochlorite
Authors: Zhu Yanshuo , Wang Juan‐Juan , Wu Danhua , Yu Wei
Published: July 2020

The C(sp3)−H chlorination of aliphatic sulfonamides was realized by visible‐light photoredox catalysis with Ru(bpy)3Cl2 as photocatalsyt and NaOCl⋅5H2O crystals as the chlorinating agent. The reaction proceeds in a tandem pattern of N−H chlorination and Hofmann‐Löffler‐Freytag chlorination. A variety of differently substituted sulfonamides were chlorinated in this way in high yield. A radical‐chain mechanism is proposed for the reaction on the basis of experimental evidence.