bluuebunny/crossref_metadata_2025 huggingface dataset:
An integrated approach in the discovery and characterization of a novel nuclear protein over‐expressed in liver and pancreatic tumors
Authors: Choong Meng Ling , Tan Li Kiang , Lo Siaw Ling , Ren Ee-Chee , Ou Keli , Ong Shao-En , Liang Rosa C.M.Y. , Seow Teck Keong , Chung Maxey C.M.
Published: July 2002

An integrated approach in protein discovery through the use of multidisciplinary tools was reported. A novel protein, Hcc‐1, was identified by analysis of the hepatocellular carcinoma (HCC)‐M cell proteome. The assembled EST sequence of the 210 amino acid novel protein was subsequently confirmed by rapid amplification of cDNA ends (RACE). A total of 687 bp at the 5′ untranslated region of Hcc‐1 was identified. Promoter activity and several upstream open reading frames (uORFs) were demonstrated at this region. Bioinformatics prediction showed that the first 42 amino acids of the protein is a SAP domain with sequence matches to hnRNP from various vertebrate species. The Hcc‐1 protein was localized to the cell nucleus while the gene was localized to chromosome 7q22.1. Hcc‐1 cDNA level was increased in pancreatic adenocarcinoma. The level was also increased in well‐differentiated hepatocellular carcinoma but decreases as the carcinoma progressed to a poorly differentiated stage.
The fission yeast meiotic regulator Mei2p undergoes nucleocytoplasmic shuttling
Authors: Sato Masamitsu , Shinozaki-Yabana Satoko , Yamashita Akira , Watanabe Yoshinori , Yamamoto Masayuki
Published: July 2002

Schizosaccharomyces pombe Mei2p is an RNA‐binding protein that switches the cell cycle from mitotic to meiotic. Mei2p forms a unique dot in the nucleus prior to meiosis I, aided by a non‐coding RNA molecule termed meiRNA. Here we show that Mei2p intrinsically undergoes nucleocytoplasmic shuttling. Artificial acceleration of nuclear migration of Mei2p advances nuclear dot formation, but meiRNA does not appear to promote the dot formation by modulating the migration rate of Mei2p into the nucleus. Rather, this RNA is likely to facilitate the assembly of Mei2p into a dot structure and trap the protein as such in the nucleus.
Inhibition of anandamide hydrolysis in rat brain tissue by (E)‐6‐(bromomethylene) tetrahydro‐3‐(1‐naphthalenyl)‐2H‐pyran‐2‐one
Authors: Beltramo Massimiliano , di Tomaso Emmanuelle , Piomelli Daniele
Published: July 2002

© Federation of European Biochemical Societies.
AMP‐activated protein kinase isoenzyme family: subunit structure and chromosomal location
Authors: Stapleton David , Woollatt Erica , Mitchelhill Ken I , Nicholl Jillian K , Fernandez C.Shamala , Michell Belinda J , Witters Lee A , Power David A , Sutherland Grant R , Kemp Bruce E
Published: July 2002

The AMP‐activated protein kinase (AMPK) consists of catalytic α and non‐catalytic, β and γ (38 kDa) subunits and is responsible for acting as a metabolic sensor for AMP levels. There are multiple genes for each subunit and we find that rat liver AMPK‐α2 isoform catalytic subunit is associated with β1 and γ1 and not with β2 or γ2 subunit isoforms. The β1 and γ1 isoforms are also subunits of the α1 isoform. The sequence of cloned human AMPK‐β1 is 95% identical in amino acid sequence with rat β1. Human chromosomal localizations were determined for AMPK‐α1 (5p11‐p14), AMPK‐β1 (12q24.1‐24.3) and AMPK‐γ1 (12q12‐q14), respectively.
The NMR solution structure of the NMDA receptor antagonist, conantokin‐T, in the absence of divalent metal ions
Authors: Warder Scott E , Chen Zhigang , Zhu Yi , Prorok Mary , Castellino Francis J , Ni Feng
Published: July 2002

The solution conformation of conantokin‐T, a Gla‐containing 21‐residue peptide, (G1EγγY5QKMLγ10NLRγA15EVKKN20A‐amide), in the absence of divalent metal ions, was studied by use of two‐dimensional proton NMR spectroscopy. The peptide is helical from the N‐terminus to the C‐terminus, as defined by upfield‐shifted α‐proton resonances and by characteristic NOE connectivities. Extensive interactions among the amino acid side‐chains were identified from the NOESY spectra of this peptide in a buffered aqueous solution. Four hydrophobic residues Tyr5, Met8, Leu9, and Leu12 contact one another in a stable cluster, even in the presence of 6 M urea. The solution structure of conantokin‐T is a well‐defined α‐helix, having RMSD values for the backbone and all heavy atoms of 0.40 Å and 0.77 Å, respectively. Potential repulsion between the negatively‐charged side chains of Gla10 and Gla14 is minimized by a Gln6‐Gla10 hydrogen bond and by an Arg13‐Gla14 ion‐pair interaction. The C‐terminal amide and the Asn20 side‐chain amide both interact with the backbone and minimize fraying at the C‐terminal end of the α‐helix. This study provides a basis to evaluate the changes in peptide conformation concomitant upon the binding of divalent metal ions. In addition, this investigation demonstrates that apo‐conantokin‐T has almost all of the favorable interactions that are known to contribute to helical stabilization in proteins and monomeric helices.
Amino acid sequence and three‐dimensional structure of the Tn‐specific isolectin B4 from Vicia villosa
Authors: Osinaga Eduardo , Tello Diana , Batthyany Carlos , Bianchet Mario , Tavares Gisele , Durán Rosario , Cerveñansky Carlos , Camoin Luc , Roseto Alberto , Alzari Pedro M
Published: July 2002

The partial amino acid sequence of the tetrameric isolectin B4 from Vicia villosa seeds has been determined by peptide analysis, and its three‐dimensional structure solved by molecular replacement techniques and refined at 2.9 Å resolution to a crystallographic R‐factor of 21%. Each subunit displays the thirteen‐stranded β‐barrel topology characteristic of legume lectins. The amino acid residues involved in metal‐ and sugar‐binding are similar to those of other GalNAc‐specific lectins, indicating that residues outside the carbohydrate‐binding pocket modulate the affinity for the Tn glycopeptide. Isolectin B4 displays an unusual quaternary structure, probably due to protein glycosylation.
The wheat wcs120 promoter is cold‐inducible in both monocotyledonous and dicotyledonous species
Authors: Ouellet François , Vazquez-Tello Alejandro , Sarhan Fathey
Published: July 2002

The wcs120 gene is specifically induced by low temperature (LT) and encodes a protein that is thought to play an important role in the cold acclimation process in wheat. To identify the regulatory elements involved in its LT responsiveness, the transient expression activity of different promoter regions was determined using the luciferase reporter gene. The data indicate the involvement of putative enhancer elements, negative and positive regulatory regions in the transcriptional regulation of this gene. The promoter was found to be cold‐inducible in different freezing‐tolerant and ‐sensitive monocot and dicot species, suggesting that universal transcription factors responsive to LT may be present in all plants. This promoter could be used to drive the genes needed for LT tolerance in sensitive species.
Specific inhibition of influenza virus RNA polymerase and nucleoprotein gene expression by circular dumbbell RNA/DNA chimeric oligonucleotides containing antisense phosphodiester oligonucleotides
Authors: Abe Takayuki , Takai Kazuyuki , Nakada Susumu , Yokota Tomoyuki , Takaku Hiroshi
Published: July 2002

We have designed a new class of oligonucleotides, `dumbbell RNA/DNA chimeric oligonucleotides', consisting of a sense RNA sequence and its complementary antisense DNA sequence, with two hairpin loop structures. The reaction of the nicked (NDRDON) and circular (CDRDON) dumbbell RNA/DNA chimeric oligonucleotides with RNase H gave the corresponding antisense phosphodiester oligodeoxynucleotide together with the sense RNA cleavage products. The liberated antisense phosphodiester oligodeoxynucleotide was bound to the target RNA, which gave RNA cleavage products by treatment with RNase H. The circular dumbbell RNA/DNA chimeric oligonucleotide showed more nuclease resistance than the linear antisense phosphodiester oligonucleotide (anti‐ODN) and the nicked dumbbell RNA/DNA chimeric oligonucleotide. The CDRDON with four target sites (influenza virus A RNA polymerases (PB1, PB2, PA) and nucleoprotein (NP)) was synthesized and tested for inhibitory effects by a CAT‐ELISA assay using the clone 76 cell line. The circular dumbbell DNA/RNA chimeric oligonucleotide (CDRDON‐PB2‐as) containing an AUG initiation codon sequence as the target of PB2 showed highly inhibitory effects.
Conversion of Amadori product of Maillard reaction to Nϵ‐(carboxymethyl)lysine in alkaline condition
Authors: Nagai Ryoji , Ikeda Kazuyoshi , Kawasaki Yukie , Sano Hiroyuki , Yoshida Masaki , Araki Tomohiro , Ueda Shoichi , Horiuchi Seikoh
Published: July 2002

N
ϵ‐(carboxymethyl)lysine (CML) is known to be formed by oxidative cleavage of Amadori products between C‐2 and C‐3 of the carbohydrate chain. We report here that CML formation from Amadori compounds is highly accelerated under alkaline conditions. Incubation of glycated human serum albumin (HSA) in 0.1 N NaOH led to the formation of CML whereas glycated HSA reduced by NaCNBH3 or non‐glycated HSA did not generate CML. N
α‐t‐butyloxycarbonyl‐N
ϵ‐fructoselysine (Boc‐FL), a model compound of Amadori product, was converted to CML under alkaline conditions. CML level of human sera (n=224) preincubated with 0.1 N NaOH correlated well with glycated albumin value (r=0.912) and hemoglobin A1c (r=0.797).
Evidence against protein kinase B as a mediator of contraction‐induced glucose transport and GLUT4 translocation in rat skeletal muscle
Authors: Lund S , Pryor P.R , Østergaard S , Schmitz O , Pedersen O , Holman G.D
Published: July 2002

Both insulin and muscle contraction stimulate glucose transport activity. However, contraction stimulation does not involve the insulin signalling intermediate phosphatidylinositol 3‐kinase (PI 3‐kinase). Protein kinase B (PKB) has recently been identified as a direct downstream target of PI 3‐kinase in the insulin signalling pathway. We have examined here whether the two stimuli share PKB as a convergent step in separate signalling pathways. Insulin stimulates both glucose transport, GLUT4 cell‐surface content and PKB activity (by 4–6‐fold above basal) in a wortmannin‐sensitive manner in in vitro incubated rat soleus muscles. By contrast, muscle contraction, which stimulates glucose transport and the cell surface content of GLUT4 by 3‐fold above basal levels, had no effect on PKB activity. These data demonstrate that PKB is not a mediator of contraction‐induced glucose transport and GLUT4 translocation.
Ca2+ channel sensitivity towards the blocker isradipine is affected by alternative splicing of the human α1C subunit gene
Authors: Zühlke R.D , Bouron A , Soldatov N.M , Reuter H
Published: July 2002

L‐type Ca2+ channels are important targets for drugs, such as dihydropyridines (DHPs), in the treatment of cardiovascular diseases. Channel expression is regulated by alternative splicing. It has been suggested that in the cardiovascular system tissue‐specific expression of different L‐type Ca2+ channel splice variants may underlie the observed differences in sensitivities to channel block by DHPs. We investigated the sensitivity of Ca2+ channel splice variants derived from the human α1C gene to the DHP isradipine. Among seven α1C channels we observed up to 10‐fold differences in IC50 values for isradipine, as well as changes in the voltage dependence of DHP action.
Acylation of Streptomyces type II polyketide synthase acyl carrier proteins
Authors: Crosby John , Byrom Kate J , Hitchman Timothy S , Cox Russell J , Crump Matthew P , Findlow I.Stuart C , Bibb Maureen J , Simpson Thomas J
Published: July 2002

Acyl derivatives of type II PKS ACPs are required for in vitro studies of polyketide biosynthesis. The presence of an exposed cysteine residue prevented specific chemical acylation of the phosphopantetheine thiol of the actinorhodin PKS holo ACP. Acylation studies were further complicated by intramolecular disulphide formation between cysteine 17 and the phosphopantetheine. The presence of this intramolecular disulphide was confirmed by tryptic digestion of the ACP followed by ESMS analysis of the fragments. An act Cys17Ser ACP was engineered by site‐directed mutagenesis. S‐Acyl adducts of act C17S, oxytetracycline and griseusin holo ACPs were rapidly formed by reaction with hexanoyl, 5‐ketohexanoyl and protected acetoacetyl imidazolides. Comparisons with type II FAS ACPs were made.
How the presence of three iron binding sites affects the iron storage function of the ferritin (EcFtnA) of Escherichia coli
Authors: Treffry Amyra , Zhao Zhongwei , Quail Michael A , Guest John R , Harrison Pauline M
Published: July 2002

The iron storage proteins, ferritins, are found in all organisms which use iron. Here iron storage processes in the Escherichia coli ferritin (EcFtnA) are compared with those in human H‐type ferritin (HuHF). Both proteins contain dinuclear iron centres that enable the rapid oxidation of 2 Fe(II) by O2. The presence of a third iron binding site in EcFtnA, although not essential for fast oxidation, causes the O2/Fe ratio to increase from 2 to 3–4. In EcFtnA the rate of iron oxidation falls markedly after the oxidation of 48 Fe(II) atoms/molecule probably because some of it remains at the oxidation site. However a compensatory physiological advantage is conferred because this iron is more readily available to meet the cell's needs.
NMDA‐receptor antagonist requirements in conantokin‐G
Authors: Blandl Tamas , Prorok Mary , Castellino Francis J
Published: July 2002

A series of variants of the neuroactive 17‐residue γ‐carboxyglutamate‐(Gla)‐containing polypeptide, conantokin‐G (con‐G), were synthesized with the intention of determining those features that were important for its N‐methyl‐d‐aspartate (NMDA) receptor‐targeted antagonist activity and for adoption of its divalent cation‐dependent α‐helical conformation. Employing the binding of [3H]dizolcipine (MK‐801) as an assay for open receptor ion channels in rat brain membranes, which displays inhibition by con‐G (IC50=0.48 μM), it was found that replacement by an Ala residue of Gla4 led to complete inactivation of the peptide, whereas a similar replacement of Gla3 resulted in a 20‐fold decreased potency. Ala substitutions for Gla10 and Gla14 did not substantially affect [3H]MK‐801 binding. This same substitution at Gla7 appeared to slightly enhance binding. Ala replacements of non‐Gla residues demonstrated that four of them, viz. Glu2, Leu5, Gln9, and Ile12, possessed at least 200‐fold decreases in inhibitory potency, whereas similar replacements at Gly1, Leu11, and Arg13 resulted in peptides with 8‐ to 12‐fold increases in the IC50 values. The remaining amino acid residues tested in the single Ala replacement series showed no significant changes in the inhibitory characteristics of wild‐type con‐G. Additional studies with carboxyl‐terminal truncated peptides revealed that the carboxyl‐terminal 4 amino acids were unimportant for this activity. There was no strict correlation of inhibition of [3H]MK‐801 binding with the ability of these peptides to form cation‐dependent α‐helices. Peptides with notably low α‐helical content in the presence of these cations were lacking at least one, or both, of Gla10 and Gla14. Con‐G[Gla3,4,7,10,14E] and con‐G[Gla7,10,14E] were the only peptides that remained in a completely random conformation upon metal ion addition.
Barley oxalate oxidase is a hexameric protein related to seed storage proteins: evidence from X‐ray crystallography
Authors: Woo Eui-Jeon , Dunwell Jim M , Goodenough Peter W , Pickersgill Richard W
Published: July 2002

The oxalate oxidase enzyme expressed in barley roots is a thermostable, protease‐resistant enzyme that generates H2O2. It has great medical importance because of its use to assay plasma and urinary oxalate, and it has also been used to generate transgenic, pathogen‐resistant crops. This protein has now been purified and three types of crystals grown. X‐ray analysis shows that the symmetry present in these crystals is consistent with a hexameric arrangement of subunits, probably a trimer of dimers. This structure may be similar to that found in the related seed storage proteins.
NADH:ubiquinone oxidoreductase from bovine heart mitochondria: sequence of a novel 17.2‐kDa subunit
Authors: Skehel J.Mark , Fearnley Ian M , Walker John E
Published: July 2002

The sequences of 41 subunits of complex I (NADH:ubiquinone oxidoreductase) from bovine heart mitochondria have been described previously. Seven of them are encoded in mitochondrial DNA, and the remainder are nuclear gene products that are imported into the organelle from the cytoplasm. By electrospray mass spectrometry experiments conducted on complex I and on two related subcomplexes, an additional protein has been identified with a mass not corresponding to any of the known subunits of the enzyme. This protein has also been found in samples of the enzyme fractionated on two dimensional polyacrylamide gels. Material from these gels has been digested with trypsin and peptide sequences have been determined, confirming that the protein did not correspond to any of the known subunits of complex I. The cDNA sequence of this protein, determined with the aid of the peptide sequences, demonstrates that it is a novel subunit of complex I, and that it is related to a 13‐kDa human protein associated with differentiation.
Classical late infantile neuronal ceroid lipofuscinosis fibroblasts are deficient in lysosomal tripeptidyl peptidase I1
Authors: Vines David J , Warburton Michael J
Published: July 2002

Tripeptidyl peptidase I (TPP‐I) is a lysosomal enzyme that cleaves tripeptides from the N‐terminus of polypeptides. A comparison of TPP‐I amino acid sequences with sequences derived from an EST database suggested that TPP‐I is identical to a pepstatin‐insensitive carboxyl proteinase of unknown specificity which is mutated in classical late infantile neuronal ceroid lipofuscinosis (LINCL), a lysosomal storage disease. Both TPP‐I and the carboxyl proteinase have an M
r of about 46 kDa and are, or are predicted to be, resistant to inhibitors of the four major classes of proteinases. Fibroblasts from LINCL patients have less than 5% of the normal TPP‐I activity. The activities of other lysosomal enzymes, including proteinases, are in the normal range. LINCL fibroblasts are also defective at degrading short polypeptides and this defect can be induced in normal fibroblasts by treatment with a specific inhibitor or TPP‐I. These results suggest that the cell damage, especially neuronal, observed in LINCL results from the defective degradation and consequent lysosomal storage of small peptides.
Evidence for an ancient chromosomal duplication in Arabidopsis thaliana by sequencing and analyzing a 400‐kb contig at the APETALA2 locus on chromosome 41
Authors: Terryn Nancy , Heijnen Leo , De Keyser Annick , Van Asseldonck Martien , De Clercq Rebecca , Verbakel Henk , Gielen Jan , Zabeau Marc , Villarroel Raimundo , Jesse Taco , Neyt Pia , Hogers René , Van Den Daele Hilde , Ardiles Wilson , Schueller Christine , Mayer Klaus , Déhais Patrice , Rombauts Stephane , Van Montagu Marc , Rouzé Pierre , Vos Pieter
Published: July 2002

As part of the European Scientists Sequencing Arabidopsis program, a contiguous region (396 607 bp) located on chromosome 4 around the APETALA2 gene was sequenced. Analysis of the sequence and comparison to public databases predicts 103 genes in this area, which represents a gene density of one gene per 3.85 kb. Almost half of the genes show no significant homology to known database entries. In addition, the first 45 kb of the contig, which covers 11 genes, is similar to a region on chromosome 2, as far as coding sequences are concerned. This observation indicates that ancient duplications of large pieces of DNA have occurred in Arabidopsis.
Requirement of the carboxy‐terminal domain of RNA polymerase II for the transcriptional activation of chromosomal c‐fos and hsp70A genes
Authors: Meininghaus Mark , Eick Dirk
Published: July 2002

The carboxy‐terminal domain of the large subunit of mouse and human RNA polymerase II contains 52 repeats of a heptapeptide which are the targets for a variety of kinases. We have used an α‐amanitin resistant form of the large subunit of pol II to study the role of the carboxy‐terminal domain in the expression of chromosomal genes. The large subunit of RNA polymerase II and deletion mutants thereof, which contain only 31 (LSΔ31) and 5 (LSΔ5) repeats, were expressed in 293 cells. Subsequently, the endogenous large subunit of RNA polymerase II was inhibited by α‐amanitin and the induction of chromosomal c‐fos and hsp70A genes was determined. Cells expressing the large subunit of RNA polymerase II and LSΔ31 were able to transcribe the c‐fos and hsp70A genes after treatment with the phorbolester TPA and after heat‐shock, respectively. In contrast, cells expressing LSΔ5 failed to induce expression of both genes.
Crystal structure of the α1β1 integrin I‐domain: insights into integrin I‐domain function
Authors: Nolte Matthias , Pepinsky R.Blake , Venyaminov Sergei Yu. , Koteliansky Victor , Gotwals Philip J. , Karpusas Michael
Published: July 2002

The α1β1 integrin is a major cell surface receptor for collagen. Ligand binding is mediated, in part, through a ∼200 amino acid inserted ‘I’‐domain contained in the extracellular part of the integrin α chain. Integrin I‐domains contain a divalent cation binding (MIDAS) site and require cations to interact with integrin ligands. We have determined the crystal structure of recombinant I‐domain from the rat α1β1 integrin at 2.2 Å resolution in the absence of divalent cations. The α1 I‐domain adopts the dinucleotide binding fold that is characteristic of all I‐domain structures that have been solved to date and has a structure very similar to that of the closely related α2β1 I‐domain which also mediates collagen binding. A unique feature of the α1 I‐domain crystal structure is that the MIDAS site is occupied by an arginine side chain from another I‐domain molecule in the crystal, in place of a metal ion. This interaction supports a proposed model for ligand‐induced displacement of metal ions. Circular dichroism spectra determined in the presence of Ca2+, Mg2+ and Mn2+ indicate that no changes in the structure of the I‐domain occur upon metal ion binding in solution. Metal ion binding induces small changes in UV absorption spectra, indicating a change in the polarity of the MIDAS site environment.
Revolution in mitochondrial medicine
Authors: Larsson Nils-Göran , Luft Rolf
Published: July 2002

A revolution in chemical pathology occurred about 40 years ago with the discovery of a patient with mitochondrial dysfunction. The field of mitochondrial medicine has experienced explosive growth during the last decade. More than 50 mtDNA mutations and several nuclear gene mutations have been identified in affected patients. The recent development of animal models will continue the revolution in mitochondrial medicine by facilitating in depth studies of the molecular pathogenesis and development of novel drug and gene therapy strategies for mitochondrial dysfunction. As we enter the next millennium, we can expect mitochondrial medicine to remain a dynamic and rapidly developing field.
Activation and expression of ERK, JNK, and p38 MAP‐kinases in isolated islets of Langerhans: implications for cultured islet survival
Authors: Paraskevas Steven , Aikin Reid , Maysinger Dusica , Lakey Jonathan R.T. , Cavanagh Thomas J. , Hering Bernhard , Wang Rennian , Rosenberg Lawrence
Published: July 2002

Isolation and purification of islet cells exposes them to ischemic, osmotic and mechanical stresses. The objective of this study was to determine the roles of the MAP‐kinases in islets immediately following isolation. During the first 48 h, activity of JNK1 and JNK2 declined markedly. Activity of p38 increased steadily with time in culture while extracellular signal regulated kinase (ERK) activity declined dramatically within 24 h post‐isolation. High p38 activation relative to ERK activation immediately following isolation correlated with a decrease in islet survival after 36 h in culture. Absence and/or transiency of ERK signaling in conjunction with sustained activation of p38 pathway could be an important regulator of cell death in islets during and following their isolation by commonly employed procedures.
Molecular characterization of the 5′ control region and of two lethal alleles affecting the hsp60 gene in Drosophila melanogaster
Authors: Perezgasga L. , Segovia L. , Zurita M.
Published: July 2002

The chaperonins are evolutionarily conserved essential cellular proteins that help folding newly synthesized or translocated proteins, spending ATP. We present here the molecular analysis of the hsp60 gene promoter region and of two Drosophila hsp60 ethyl methane sulfonate embryonic lethal alleles that have an identical phenotype. No heat shock element sequences were found in the 5′ region, supporting previous data (Kozlova, T. et al., 1997) which suggests that mitochondrial Drosophila melanogaster HSP60.1 is not heat inducible. By sequencing the lethal allele's entire open reading frame (ORF), we found a C‐T transition in the hsp60
F409 allele that produces a serine to leucine change, apparently distorting the protein equatorial domain structure. No changes were found in the hsp60
G93 ORF. However, an analysis of the heterogeneous nuclear RNA levels showed a reduction of the hsp60 transcript in hsp60
G93 flies as compared to the wild‐type. These data suggest that although the defects in the hsp60 gene produced by these alleles are at different levels, both behave as null mutations.
Identification and characterization of splice variants of ephrin‐A3 and ephrin‐A5
Authors: Lai Kwok-On , Ip Fanny C.F. , Ip Nancy Y.
Published: July 2002

Ephrins and Eph receptors have been implicated to play important roles in axon guidance. A variable spacer region exists that differs significantly among distinct ephrins. An ephrin‐A5 isoform has previously been isolated which lacks 27 amino acids within the spacer region. The expression and biological activities of this isoform, as well as the existence of isoforms for other ephrins that show variation within the spacer region, remain unknown. We report here a novel alternatively spliced isoform of ephrin‐A3 which lacks the corresponding variable region. When compared to the longer isoforms, the shorter isoforms of both ephrin‐A3 and ephrin‐A5 remained less prominent in the brain during development, though their expression increased at postnatal stages. In addition, they could inhibit neurite outgrowth of dorsal root ganglia (DRG) neurons, suggesting that the corresponding variable regions were not essential for their axon guidance activities.
Prenatal strategies for reducing severe thalassemia in pregnancy
Authors: Wanapirak C , Tongsong T , Sirivatanapa P , Sa‐nguansermsri T , Sekararithi R , Tuggapichitti A
Published: July 2002

Objective: To describe the prenatal strategy in reducing new cases of severe thalassemia at Maharaj Nakorn Chiang Mai Hospital. The study design involved a prospective descriptive analysis set in Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University. Subjects: Pregnant women attending antenatal clinic. Methods: The strategy included: (1) carrier identification by retrospective (history review) and prospective screening program; (2) the couples at risk were counseled and offered cordocentesis; (3) analysis of fetal blood with high performance liquid chromatography (HPLC) or electrophoresis; and (4) counseling for termination of pregnancy in case of affected fetus. The prospective screening consisted of testing for a carrier by a simple erythrocyte osmotic fragility test (EOFT) in women with no risk and testing the husbands of the women with abnormal tests. A pregnancy in which both of the couple were carriers was considered a risk. Results: Cordocentesis was performed in 554 pregnancies at risk, 252 and 302 from retrospective and prospective screening, respectively. Sixty of 252 of the first group had severe thalassemia. In the prospective screening program of 12 680 women, 459 risk couples were identified, 302 pregnancies underwent cordocentesis and 53 (17.5%) had severe thalassemia. This strategy enabled us to identify 113 cases of severe thalassemia (Hb Bart's; 60, β‐thal entities; 53) from 554 cases at risk. Conclusion: The strategy proves valuable in the control of severe thalassemia. This extensive experience suggests the strategy be considered an effective way in the control of severe thalassemia in high prevalence areas.
Erythropoietin in amniotic fluid as a marker of chronic fetal hypoxia
Authors: Buescher U , Hertwig K , Wolf C , Dudenhausen J.W
Published: July 2002

Objective: To determinate the erythropoietin concentration in amniotic fluid in normal pregnancies and pregnancies with suspected hypoxia. Method: The erythropoietin concentration of 164 samples of amniotic fluid was determined by ELISA. The samples were taken by amniotomy during birth, as well as amniocentesis conducted during prenatal care. Results: A distribution of 1.07–7.29 U/l (10th–90th percentile) within the normal group (n=106) was determined. Significantly elevated erythropoietin levels in amniotic fluid were determined in maternal hypertension (P=0.039) and low birth‐weight children (P=0.0032). A correlation with the child's sex could be excluded. Conclusion: Elevated erythropoietin levels in amniotic fluid indicated chronic fetal hypoxia.
Medical versus surgical abortion
Authors: Cabezas E
Published: July 2002

Objective: To evaluate the safety, efficacy, and acceptability of an oral drug regimen of medical abortion compared with surgical abortion. Materials and methods: 500 women with amenorrhea <56 days chose either surgical abortion or 600 mg of mifepristone (RU‐486) followed by 400 μg of misoprostol after 48 h. Results: Medical regimen had more side effects than surgical abortion, including bleeding, cramping, nausea and vomiting. Only fever was more frequent in the surgical method. The failure rates for medical abortion exceeded those for surgical abortion, 16.0% vs. 4.0%. The adolescents' failure rate in the medical regimen group was only 1.7%. Several failures on medical abortion were not true drug failures, but surgical interventions not medically necessary (misdiagnosis). Women were satisfied with either method, but more preferred medical abortion. Conclusion: Medical methods are safe, effective, simpler and potentially allow greater privacy than surgical abortion methods. Therefore, medical methods could be the method of choice for abortion, particularly for adolescents.
Non‐photic signalling in the suprachiasmatic nucleus
Authors: Hastings Michael H. , Duffield Giles E. , Ebling Francis JP , Kidd Andrew , Maywood Elisabeth S. , Schurov Irina
Published: July 2002

Scheduled arousal by handling and sub‐cutaneous saline injection entrains the free‐running clock of the adult Syrian hamster and outbred (ID(ICR)) but not inbred (C57B16) mice. Syrian hamsters bearing lesions of the intergeniculate leaflet of the thalamus remain able to entrain and phase‐shift to light, but the lesions block completely entrainment by serial arousal, even though lesioned animals continue to respond acutely to the arousing cue. This suggests that the innervation from the IGL to the SCN is a necessary component of the pathways which signal an aroused state to the clock. Siberian hamsters do not entrain to serial arousal but they do entrain to serial injections of melatonin, whereas in adult Syrian hamster, systemic treatment with melatonin has no effect above that of arousal. In contrast to the adult, the foetal and neonatal Syrian hamster can be entrained by melatonin. These variations in sensitivity correlate with inter‐specific and developmental differences in the pattern and level of expression of melatonin receptors in the SCN. The perinatal hamster can also be entrained by dopaminergic agonists. SCN tissue from neonatal Syrian hamsters was used to characterise the biochemical actions of dopamine and melatonin. In primary culture and tissue explants, forskolin, dopamine and glutamatergic agonists all stimulated the phosphorylation of the transcription factor CREB. This probably occurred via convergent actions through Ca2+ (glutamate) and cyclic AMP‐dependent (forskolin, dopamine) signalling pathways. Dopamine induced phospho‐CREB‐ir exclusively in GABA‐ir neurons and melatonin reversed this effect of dopamine, indicative of an inhibitory Gi protein linking via the Mel1a receptor to adenylyl cyclase. The regulation of phospho‐CREB by multiple entraining cues in the SCN highlights its position as a point of convergence for regulators of the clock, and indicates a possible role in entrainment.
Lead exposure alters Egr‐1 DNA‐binding in the neonatal rat brain
Authors: Reddy G.R. , Zawia N.H.
Published: July 2002

Zinc finger proteins (ZFP) contain a structural motif (Cys‐2 His‐2) found in a large family of eukaryotic transcriptional regulatory proteins, such as Spl. Previous studies have shown that Sp1 DNA‐binding was disrupted by exposure to lead (Pb), due to action on its zinc finger domain. In this paper, we discuss the results of studies with another ZFP, Egr‐1, an early growth response gene, which is functionally involved in cell proliferation and differentiation. Egr‐1 DNA‐binding was studied by gel shift mobility assays in several brain regions of developing rat pups. We observed a distinct developmental profile of Egr‐1 DNA‐binding with a gradual increase from the early to late postnatal days in all the brain regions examined. Lactational exposure to Pb resulted in a modulation of Egr‐1 DNA binding manifested by premature peaks in DNA‐binding reminiscent of the in vivo changes previously reported for Spl. These data are consistent with earlier findings that exposure to Pb both in vivo and in vitro causes a modulation in the DNA‐binding of ZFP such as Sp1, Egr‐1 and TFIIIA. The commonality by which Pb exposure alters the DNA‐binding patterns of ZFP suggests that divalent Pb may be interacting directly with the Zn moiety of these proteins.
Interindividual variation of cerebral activation during encoding and retrieval of words
Authors: Heun R , Jessen F , Klose U , Erb M , Granath D.O , Freymann N , Grodd W
Published: July 2002

The aim of the present study was to compare the cerebral activation associated with encoding and retrieval in individual subjects with the average activation in the same group of subjects. Twelve volunteers performed two paradigms: 1) intentional encoding of words, and 2) recognition of learned words intermixed with new distracters. Echo-planar magnetic resonance imaging (MRI) of BOLD signal changes was used to compare cerebral activation between active and resting conditions. During encoding, activation of the left precentral gyrus related to the motor response was observed in some subjects. Averaged data showed increased activation of the left precentral gyrus, the supplementary motor area (SMA), the left inferior frontal gyrus and in the left temporo-occipital junction. During recognition, motor response-related activity was found in the precentral cortex and SMA in most subjects. Activation in other brain areas showed considerable interindividual variation. In the entire group, recognition showed activation of the left dorsolateral prefrontal cortex, the precentral gyrus, the SMA, and the temporo-occipital junction. The total amount and the distribution of task-related cerebral activation varies considerably between individuals and might correspond to individual preferences of cognitive strategies. The investigation of these interindividual variations will be an exciting scientific challenge in the near future.
First report of mirtazapine-induced arthralgia
Authors: Jolliet P. , Veyrac G. , Bourin M.
Published: July 2002

Objective.

The aim of our work is to describe the first two cases of arthralgia associated with the antidepressant drug mirtazapine.

Method.

Descriptive analysis of two iatrogenic cases. The review of the literature was achieved by the traditional electronic methods. The French database of iatrogenic cases was consulted.

Results.

A 53-year-old man presented with gonalgia after some weeks of mirtazapine treatment. The intensity of the arthralgia was correlated with the dosage and the adverse effect rapidly disappeared after the antidepressant therapy was stopped. A 38-year-old woman received mirtazapine for 3 months and complained of arthralgia and myalgia. This clinical picture was suspended as the drug was stopped and a positive reintroduction was observed. No other cause was found in these two patients.

Discussion.

No similar case has been reported in the international literature, but several observations of arthralgia with mianserin are mentioned. As mirtazapine is the 6-aza derivative of the tetracyclic antidepressant mianserin, the similarities of their chemical structures begs the responsibility of mirtazapine for arthralgia.
Follow-up studies of schizophrenia I: Natural history and non-psychopathological predictors of outcome
Authors: van Os J , Wright P , Murray RM
Published: July 2002

Treatment-resistant schizophrenia does not exist as a discrete entity, so separating patients who will fail to respond to traditional antipsychotics from those who will respond is impossible with 100% accuracy. However, several predictors of poor clinical outcome have emerged from recent research and knowledge of the processes that lead to poor outcome has become increasingly important with the advent of atypical antipsychotics that may be used in patients with treatment-resistant illness. Much of the variation in outcome can be understood in terms of differences in sample selection, outcome definition and stringency of the diagnostic criteria used. Failure to appreciate these mechanisms may lead to over- or underestimation of the proportion of patients with poor treatment response in clinical and research settings. The importance of factors that predict poor outcome should be judged in terms of their effect size and the degree to which alternative explanations for the association with outcome have been excluded. Although much current research is being focused on specific biological predictors, baseline demographic and illness-related factors, such as ethnic group, sex, social class, type of onset, age of onset and concurrent misuse of alcohol or drugs, have large effects on outcome. Although duration of untreated psychosis before first contact with services may independently predict poor outcome, confounding by variables that are associated with both pathways to care and clinical outcome has not been excluded.
China as great power: from red menace to green giant?
Authors: Foster Gregory D.
Published: July 2002

China's standing in the world—whether it is, or is seen to be, a great power—is a question of signal importance because of what great powers are capable of doing, what effects their actions and words have on others, and what is expected of them. By most conventional measures, China is at least on the verge of being a great power. Yet the country also occupies a pivotal global position in terms of its present and expected future impact on the environment. In the final analysis, because greatness is so much a function of a willingness to shoulder responsibility and demonstrate leadership, China's standing as a great power may well be determined by the country's response to the acute environmental stresses it faces. Published by Elsevier Science Ltd on behalf of The Regents of the University of California.
The effects of enalapril‐digoxin‐diuretic combination therapy on nutritional and anthropometric indices in chronic congestive heart failure: preliminary findings in cardiac cachexia
Authors: Adigun A.Q. , Ajayi A.A. Leslie
Published: July 2002

Background:

Body wasting is a clinical feature of a variety of chronic illnesses including congestive heart failure. The wasting associated with chronic congestive heart failure (cardiac cachexia) has recently been shown to portend a worse prognosis, and it is an independent predictor of mortality. The mechanisms underlying cardiac cachexia are multi‐factorial, including metabolic, nutritional, neuroendocrine and immunological aberrations. There is, however, no direct evidence that current medical treatment reverses cachexia in chronic heart failure.

Methods:

The effect of enalapril, digoxin and frusemide combination on clinical, biochemical and anthropometric indices were determined in eight cachectic Nigerians with chronic congestive heart failure [body mass index (BMI) 20.80 ± 2.7 kg/m2, left ventricular ejection fraction 29 ± 4% and LV mass index 161 + 37 g/m2] at baseline, and again after 3 and 6 months of therapy. Ten age‐ and sex‐matched healthy volunteers whose anthropometric data were concurrently measured served as controls.

Results:

The anthropometric and clinical measurements were significantly (P < 0.001) reduced in heart failure compared to the healthy controls. Congestive hepatomegaly significantly regressed from 161 ± 20 mm to 123 ± 13 mm after 6 months therapy (P < 0.001 ANOVA). There was a significant increase in the sum of four skin fold thickness from 27.6 ± 3.3 mm to 30.1 ± 3.9 mm at 6 months (P < 0.001 ANOVA) 95% confidence intervals for the difference being 1.42 to 3.4 mm. There was a significant increase in the mid‐upper arm circumference (P < 0.001 ANOVA) with a 95% confidence interval of 0.87 – 2.1 cm, and a similar trend for increased mid‐thigh circumference (95% confidence limits 0.93 – 5.30 cm) was apparent. Plasma albumin and sodium increased significantly (P < 0.05) from 30.1 ± 3.8 g/l and 136 ± 5.9 mmol/l to 32.9 ± 2.5 g/l and 139 ± 3.9 mmol/l, respectively. There was a positive and significant correlation between the treatment induced increases in plasma albumin and the increase in mid‐upper arm circumference (y ‐ 0.25x + 0.8, r ‐ 0.76, P ‐ 0.03 ANOVA) but not with the change in skin fold thickness.

Conclusion:

The preliminary results demonstrate increased subcutaneous fat (increased skin fold thickness), greater muscle bulk (increased mid‐upper arm and thigh circumferences) together with a significant elevation in plasma albumin and the hematocrit, which reflect the anabolic state in patients treated with ACE inhibitor–digoxin–diuretic with congestive heart failure.
Chiral Photodetector Based on GaAsN
Authors: Joshya Rajagopal Shyamala , Carrère Hélène , Ibarra‐Sierra Victor Guadalupe , Sandoval‐Santana Juan Carlos , Kalevich Vladimir K. , Ivchenko Eugeniyus L. , Marie Xavier , Amand Thierry , Kunold Alejandro , Balocchi Andrea
Published: April 2021

The detection of light helicity is key for various applications, from drug production to optical communications. However, the light helicity direct measurement is inherently impossible with conventional photodetectors based on III–V or IV–VI non‐chiral semiconductors. The prior polarization analysis by often moving optical elements is necessary before light is sent to the detector. A method is here presented to effectively give the conventional dilute nitride GaAs‐based semiconductor epilayer a chiral photoconductivity. The detection scheme relies on the giant spin‐dependent recombination of conduction electrons and the accompanying spin polarization of the engineered defects to control the conduction band. As the conduction electron spin polarization is, in turn, intimately linked to the excitation light polarization, the light polarization state and intensity can be determined by a simple conductivity measurement. This approach, removing the need for any optical elements in front of a non‐chiral detector, could offer easier integration and miniaturization. This new chiral photodetector could potentially operate in a spectral range from the visible to the infra‐red using (InGaAl)AsN alloys or ion‐implanted nitrogen‐free III–V compounds.
Extracellular Vesicles from 3D Engineered Microtissues Harbor Disease‐Related Cargo Absent in EVs from 2D Cultures
Authors: Millan Christopher , Prause Lukas , Vallmajo‐Martin Queralt , Hensky Natalie , Eberli Daniel
Published: April 2021

Engineered microtissues that recapitulate key properties of the tumor microenvironment can induce clinically relevant cancer phenotypes in vitro. However, their effect on molecular cargo of secreted extracellular vesicles (EVs) has not yet been investigated. Here, the impact of hydrogel‐based 3D engineered microtissues on EVs secreted by benign and malignant prostate cells is assessed. Compared to 2D cultures, yield of EVs per cell is significantly increased for cancer cells cultured in 3D. Whole transcriptome sequencing and proteomics of 2D‐EV and 3D‐EV samples reveal stark contrasts in molecular cargo. For one cell type in particular, LNCaP, enrichment is observed exclusively in 3D‐EVs of GDF15, FASN, and TOP1, known drivers of prostate cancer progression. Using imaging flow cytometry in a novel approach to validate a putative EV biomarker, colocalization in single EVs of GDF15 with CD9, a universal EV marker, is demonstrated. Finally, in functional assays it is observed that only 3D‐EVs, unlike 2D‐EVs, confer increased invasiveness and chemoresistance to cells in 2D. Collectively, this study highlights the value of engineered 3D microtissue cultures for the study of bona fide EV cargoes and their potential to identify biomarkers that are not detectable in EVs secreted by cells cultured in standard 2D conditions.
Asymmetric Synthesis of Spirocyclopentane Oxindoles via [2+3] Annulation with 2‐(2‐Oxoindolin‐3‐yl)malononitriles as 1,2‐Carbon Bisnucleophiles
Authors: Ai Yue‐Yan , Li Dong‐Ai , Li Guo , Li He‐Ping , He Xiang‐Hong , Fu Xue‐Ju , Wang Yu‐Ting , Zhan Gu , Han Bo
Published: April 2021

Carbon bisnucleophiles are important building blocks in organic synthesis and have widespread applications in the construction of carbocyclic compounds. Among them, 1,2‐carbon bisnucleophile has been much less explored. Herein, we developed a [2+3] annulation of 2‐(2‐oxoindolin‐3‐yl)malononitrile with 2‐nitroallylic acetates, where 2‐(2‐oxoindolin‐3‐yl)malononitrile served as a new type of 1,2‐carbon bisnucleophile. Remarkably, the annulation reaction exhibits exclusive chemo‐ and regioselectivity. A Michael addition/SN2 mechanism was proposed to avoid the “anti‐Baldwin” cyclization. This stereoselective strategy provides a facile synthetic route for a new series of spirocyclopentane oxindole derivatives containing three stereogenic centers.

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Dynamic Windows Using Reversible Zinc Electrodeposition in Neutral Electrolytes with High Opacity and Excellent Resting Stability
Authors: Islam Shakirul M. , Barile Christopher J.
Published: April 2021

Dynamic windows, which electronically switch between clear and dark states, can play a vital role in energy‐efficient buildings by reducing lighting, heating, and cooling demands. In this manuscript, reversible Zn electrodeposition on tin‐doped indium oxide electrodes is studied and a mechanism is proposed that explains the deposition and dissolution processes. This mechanistic understanding enables the construction of 100 cm2 two‐electrode devices that transition from clear (80% transmission at 600 nm) to highly opaque (<0.1% transmission at 600 nm) in less than 20 s. Additionally, the dynamic windows utilize a pH‐neutral electrolyte, which enables them to switch without degradation over the course of four weeks. The high opacity and stability of the Zn‐based devices represent significant improvements over existing switchable thin films based on the reversible electrodeposition of more noble metals such as Bi and Cu.