bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of immunoreactive mammalian gonadotropin‐releasing hormone in the brain of metamorphic larvae of Bufo arenarum hensel (Amphibia: Anura)
Authors: Somoza Gustavo M. , Paz Dante A. , Stefano Andrea V. , Affanni Jorge M.
Published: July 2002

Gonadotropin‐releasing hormone (GnRH) immunoreactivity in brain extracts of Bufo arenarum tadpoles were investigated by high‐performance liquid chromatography, followed by radioimmunoassay analysis using two different antisera raised against different GnRH variants. Only one immunoreactive peak was identified, eluting in the same position as synthetic mammalian GnRH. This result was further confirmed by serial dilution studies using more specific mammalian GnRH antisera. Our results suggest that mammalian GnRH is most likely an endogenous peptide in the brain of the developing larvae and froglets of Bufo arenarum and quite likely it is the only GnRH variant present during those development stages. The distribution and density of cell bodies and fibers were analysed by immunocytochemical procedures. Immunoreactive cell bodies appeared in the olfactory epithelium and across the olfactory nerve at late prometamorphic larval stages. Near the metamorphic climax and in froglets, perikarya and fibers were detected in basal forebrain, preoptic and hypothalamic areas. No immunoreaction was observed at midbrain, hindbrain and spinal cord levels. This study suggests that mammalian GnRH is most likely an endogenous peptide and is probably the only GnRH variant in the brain of the developing larvae and froglets of Bufo arenarum.
β Subunit heterogeneity of L‐type Ca2+ channels in smooth muscle tissues
Authors: Reimer Daniel , Huber Irene G. , Garcia Maria L. , Haase Hannelore , Striessnig Jörg
Published: July 2002

Various β subunit isoforms stabilize different gating properties of voltage‐gated L‐type Ca2+ channels. We therefore investigated the expression of Ca2+ channel β subunit isoforms in different smooth muscle types on the protein level by immunoblotting and immunoprecipitation employing β subunit‐selective sequence‐directed antibodies. From the four known β subunit isoforms only β2 and β3 were detected in porcine uterus, bovine trachea and bovine aorta membranes. Multiple immunoreactive β2 bands were detected in a tissue‐selective manner indicating structural heterogeneity of β2. Immunoprecipitation of (+)‐[3H]isradipine‐prelabeled channels revealed that β2 and β3 participate in Ca2+ channel formation in uterus and trachea, and β3 in aortic smooth muscle. We conclude that β2 and β3 subunits form L‐type Ca2+ channels in smooth muscle tissues. This subunit heterogeneity may be important to fine‐tune channel function.
Dipeptide synthesis by an isolated adenylate‐forming domain of non‐ribosomal peptide synthetases (NRPS)
Authors: Dieckmann Ralf , Neuhof Torsten , Pavela-Vrancic Maja , von Döhren Hans
Published: July 2002

A deletion mutant of tyrocidine synthetase 1 (ΔΔTY1), comprising the adenylation domain of TY1 as an independent functional adenylate‐forming unit, was used to investigate the ability of the adenylation domain in non‐ribosomal peptide synthetases to catalyse peptide bond formation from the aminoacyl adenylate intermediate. The results demonstrate that only one substrate amino acid needs to be activated as an aminoacyl adenylate. In view of the potential exploitation of peptide synthetases for enzymatic synthesis of dipeptides of choice, it is important to note that this does not necessarily require a dimodular construct or an intermediate acyl transfer step.
The effect of mild trypsin digestion of F1 on energy coupling in the mitochondrial ATP synthase
Authors: Xu Ting , Candita Cosimo , Papa Sergio
Published: July 2002

Mild trypsin digestion of isolated bovine‐heart mitochondrial F1‐ATPase removed the first 15 residues from the N‐terminus of subunit a under conditions in which other F1 subunits were apparently untouched. When the trypsinized F1 (TF1) was reconstituted with the F0 sector in the mitochondrial membrane (USMP), the ATP hydrolase activity acquired oligomycin sensitivity but ATP hydrolysis was decoupled from proton pumping. TF1 added to USMP did not block the proton channel in F0 as the native F1 did. AMP‐PNP inhibited proton conductivity in reconstituted F1‐USMP but this effect was lost in reconstituted TF1‐USMP. These results indicate that the N‐terminus of the F1 α subunit plays a critical role in the conformational communication between F1 and F0
Crystallization and preliminary X‐ray analysis of a thiol‐activated cytolysin
Authors: Feil Susanne C. , Rossjohn Jamie , Rohde Kyle , Tweten Rodney K. , Parker Michael W.
Published: July 2002

We present the first reported crystallization of a member of the thiol‐activated family of protein toxins. Perfringolysin O, a virulence factor of Clostridium perfringens, has been crystallized in two different forms by the hanging drop vapor diffusion method. In one form the toxin crystallizes with PEG 20000 in the orthorhombic space group C2221 with cell dimensions of and the crystals diffract to beyond 2.5 Å resolution. In the second form the toxin crystallizes in a large variety of organic solvents including malt whisky. This crystal form belongs to the orthorhombic space group P2221 with unit cell dimensions and with diffraction observed to 2.4 Å resolution.
Identification and expression of a variant isoform of the levocabastine‐sensitive neurotensin receptor in the mouse central nervous system
Authors: Botto Jean-Marie , Sarret Philippe , Vincent Jean-Pierre , Mazella Jean
Published: July 2002

This work describes the molecular cloning of a variant isoform of the low‐affinity levocabastine‐sensitive neurotensin receptor isolated from mouse brain. Although the corresponding mRNA encodes for a 282 amino acid protein unable to bind neurotensin after transient transfection in COS‐7 cells, this non‐functional neurotensin receptor is expressed in cerebral neocortex, cerebellum, olfactory bulb, striatum and hypothalamus with a level similar to that of the full‐length low‐affinity neurotensin receptor. By contrast, this receptor form is very weakly expressed in mesencephalon and absent in the pituitary, but is the major product in the spinal cord.
Potent inhibition of inducible nitric oxide synthase by geldanamycin, a tyrosine kinase inhibitor, in endothelial, smooth muscle cells, and in rat aorta
Authors: Joly Ghislaine A , Ayres Mary , Kilbourn Robert G
Published: July 2002

©1997 Federation of European Biochemical Societies.
Pancreas specific protein disulfide isomerase, PDIp, is in transient contact with secretory proteins during late stages of translocation
Authors: Volkmer Jörg , Guth Silvia , Nastainczyk Wolfgang , Knippel Peter , Klappa Peter , Gnau Volker , Zimmermann Richard
Published: July 2002

Protein disulfide isomerase (PDI) and an additional lumenal protein of dog pancreas microsomes were previously observed to be in transient contact with secretory proteins during late stages of their co‐ or posttranslational translocation into these mammalian microsomes. The second protein was characterized as a 57 kDa glycoprotein. Here we identified this glycoprotein as the canine equivalent of human PDIp, a protein which was recently described as a new protein disulfide isomerase which is highly expressed in human pancreas. Canine PDIp is also a very abundant protein, its concentration in pancreatic microsomes approaches the concentration of PDI and of the major microsomal molecular chaperones. Apparently, PDIp shares with PDI not just the enzymatic but also the polypeptide binding or chaperoning activity. Furthermore, we suggest that PDIp, too, can be involved in completion of cotranslational as well as posttranslational translocation of proteins into mammalian microsomes.
Stimulation of osteoblast proliferation by the cartilage‐derived growth promoting factors chondromodulin‐I and ‐II
Authors: Mori Yoshihisa , Hiraki Yuji , Shukunami Chisa , Kakudo Shinji , Shiokawa Miho , Kagoshima Masako , Mano Hiroshi , Hakeda Yoshiyuki , Kurokawa Takahide , Suzuki Fujio , Kumegawa Masayoshi
Published: July 2002

We previously reported the isolation of the cartilage‐derived growth promoting factors chondromodulin‐I (ChM‐I) and chondromodulin‐II (ChM‐II) from fetal bovine epiphyseal cartilage. Both of these factors stimulate the growth and matrix formation of chondrocytes in vitro. In the present study, we found that ChM‐I and ChM‐II stimulated the proliferation of clonal mouse osteoblastic MC3T3‐E1 cells as well as primary mouse osteoblasts in culture. Unlike other known growth factors, these factors did not support the proliferation of fibroblasts. Concomitantly with growth stimulation of osteoblasts, there was a reduction of alkaline phosphatase (ALP) activity in the cells, the expression of the differentiated phenotype. These results suggest that epiphyseal cartilage may play a functional role in longitudinal bone growth by production of these unique growth‐promoting factors.
Cytotoxic activity of ribonucleolytic toxin restrictocin‐based chimeric toxins targeted to epidermal growth factor receptor
Authors: Rathore Dharmendar , Batra Janendra K
Published: July 2002

Targeted toxins represent a new approach to specific cytocidal therapy. The ribonucleolytic protein toxin restrictocin is a potent protein synthesis inhibitor produced by the fungus Aspergillus restrictus. In the present study we have constructed two restrictocin based chimeric toxins where human transforming growth factor alpha (TGFα) has been used as a ligand. TGFα is a single chain polypeptide, which binds to epidermal growth factor receptor (EGFR) and causes proliferation in a large number of cancers. The ligand has been separately fused either at the amino terminus or carboxyl terminus of restrictocin, giving rise to TGFα‐restrictocin and restrictocin‐TGFα respectively. The fusion proteins were overexpressed in Escherichia coli and purified from inclusion bodies by a denaturation‐renaturation protocol. Both the chimeric toxins actively inhibited eukaryotic protein synthesis in a cell free in vitro translation assay system. These chimeric toxins selectively killed human epidermal growth factor receptor positive target cells in culture. Among the two proteins, restrictocin‐TGFα was more active than TGFα‐restrictocin on all the cell lines studied.
The use of recombinant vaccinia virus to generate monoclonal antibodies against the cell‐surface glycoprotein endoglin
Authors: Luque Alfonso , Cabañas Carlos , Raab Ulla , Letamendı́a Ainhoa , Páez Eduardo , Herreros Lourdes , Sánchez-Madrid Francisco , Bernabeu Carmelo
Published: July 2002

Characterization of novel cell‐surface protein molecules, initially identified by cDNA cloning techniques, usually requires the generation of specific antibodies to further analyze their biochemical and/or functional properties. Here we report a simple method, using recombinant vaccinia virus, for the generation of monoclonal antibodies (mAb) to the cell‐surface antigen endoglin. A recombinant vaccinia virus carrying a cDNA encoding human endoglin was inserted into the thymidine kinase locus under the control of the 7.5k vaccinia virus promoter. Infection of Balb/c mice with this recombinant virus led to the generation of specific polyclonal antibodies, as demonstrated by the antisera reactivity against human endoglin transfectants. The spleen cells of these infected animals were fused to myeloma cells, allowing efficient generation of several hybridomas which secrete mAbs to human endoglin, as evidenced by their reactivity with purified endoglin as well as with endoglin transfectants. Some of the mAbs selected seem to be specific for regions of endoglin conserved among different species as evidenced by their cross‐reactivity with chicken endoglin. These results underline the utility of recombinant vaccinia virus to generate antibodies with novel properties to new cell surface proteins such as endoglin.
Possible involvement of radical reactions in desialylation of LDL
Authors: Tanaka Kyoko , Tokumaru Sadako , Kojo Shosuke
Published: July 2002

The role of oxidatively modified LDL in the pathogenesis of atherosclerosis has been well documented. These studies have focused on modifications of lipid and protein parts of LDL. Recently desialylated LDL has received attention in relation to atherosclerosis and coronary artery disease. We examined the possible involvement of radical reactions in desialylation of LDL. Human LDL was subjected to oxidative damage using Cu2+ ion. As the conjugated dienes monitored by absorption at 234 nm increased, the content of sialic acid decreased steadily. Both the elevation of conjugated diene and the decrease of sialic acid were inhibited by β‐mercaptoethanol, a typical radical scavenger. Besides, both butylated hydroxytoluene and a nitrogen atmosphere inhibited the decrease of sialic acid. These inhibition experiments suggested that sialic acid moieties in LDL were reactive toward radicals.
The Na+,K+‐ATPase carrying the carboxy‐terminal Ca2+/calmodulin binding domain of the Ca2+ pump has 2Na+,2K+ stoichiometry and lost charge movement in Na+/Na+ exchange
Authors: Yoshimura Shige H , Vasilets Larisa A , Ishii Toshiaki , Takeyasu Kunio , Schwarz Wolfgang
Published: July 2002

An altered ion‐transport stoichiometry from 3Na+,2K+ to 2Na+,2K+ is observed in a chimeric Na+,K+‐ATPase, which carries the Ca2+/calmodulin binding domain (CBD) of the plasma membrane Ca2+‐ATPase at its carboxy‐terminus [Zhao et al., FEBS Lett. 408 (1997) 271–275]. The ouabain‐resistant mutant of this chimera (ORα1‐CBD) was constructed to further investigate the effect of the CBD on ion‐transport properties. The ORα1‐CBD still shows the 2Na+,2K+ stoichiometry. The loss of electrogenicity is accompanied by the disappearance of transient charge movements in the Na+/Na+ exchange mode. We conclude that the binding of the third Na+ ion, but not of the two others, in 3Na+,2K+ transport mode apparently senses the electric field, and that the voltage‐dependent Na+ binding is likely to be lost in the chimera with CBD.
High affinity calmodulin target sequence in the signalling molecule PI 3‐kinase
Authors: Fischer Roland , Julsgart Juanitta , Berchtold Martin W
Published: July 2002

In this study we report that phosphatidylinositol 3‐kinase (PI 3‐kinase), a lipid kinase which participates in downstream signalling events of heterotrimeric G protein‐coupled receptors and receptor tyrosine kinases, contains a high affinity binding site for calmodulin (CaM). The putative CaM‐binding peptide derived from the p110γ isoform interacts with CaM in a calcium‐dependent way. Using gel shift analysis and fluorescence spectrophotometry we discovered that the peptide forms a high affinity complex with CaM. Titration experiments using dansylated CaM gave an affinity constant of 5 nM. Furthermore, a sequence comparison among different PI 3‐kinase isoforms revealed that the sequence which can bind CaM is highly conserved within different PI 3‐kinase isoforms. These results indicate a novel mechanism for regulating PI 3‐kinase and provide a new direct link between Ca2+ and phospholipid signalling pathways.
The skin‐type antifreeze protein gene intron of the winter flounder is a ubiquitous enhancer lacking a functional C/EBPα binding motif
Authors: Miao Ming , Chan Shing-Leng , Hew Choy L , Gong Zhiyuan
Published: July 2002

The winter flounder antifreeze protein (AFP) intron contains a liver‐specific enhancer (Element B) which was shown earlier to bind CCAAT/enhancer binding protein (C/EBP)α. In contrast, as demonstrated in the present studies, the intron of the skin‐type AFP gene acted as a ubiquitous enhancer and contained a TA insertion at similar region to Element B (Element S) which destroyed its interaction with C/EBPα. Furthermore, a TA insertion of Element B by site‐directed mutagenesis decreased its liver enhancer activity. The presence or absence of C/EBPα binding motifs in Element B and Element S, respectively, may provide a mechanism for their differential expression.
Distinct phospholipase C‐regulated signalling pathways in Swiss 3T3 fibroblasts induce the rapid generation of the same polyunsaturated diacylglycerols
Authors: Pettitt Trevor R , Wakelam Michael J.O
Published: July 2002

Prostaglandin F2α, platelet‐derived growth factor (PDGF) and calcium ionophore A23187 stimulated the rapid (within 25 s) generation of polyunsaturated 1,2‐diacylglycerol (DAG) species, in particular 18:0/20:3n‐9, 18:0/20:4n‐6 and 18:0/20:5n‐3, in Swiss 3T3 fibroblasts. This was followed by a second sustained phase characterised by saturated, monounsaturated and diunsaturated DAG species derived, at least partially, from a phospholipase D/phosphatidate phosphohydrolase‐linked pathway. This could be directly activated by phorbol ester. Assay of rat brain protein kinase C (PKC) in lipid vesicles showed that first phase, polyunsaturated‐enriched DAG isolated from Swiss 3T3 cells was a more potent activator of kinase activity compared to that achieved with DAG from control or 5 min stimulated cells. Thus activation of distinct members of the phospholipase C family leads to the rapid and almost identical generation of polyunsaturated DAG species which are capable of preferentially activating protein kinase C (PKC).
Activation of mitogen‐activated protein kinases (p38‐MAPKs, SAPKs/JNKs and ERKs) by adenosine in the perfused rat heart
Authors: Haq Syed E.A. , Clerk Angela , Sugden Peter H.
Published: July 2002

Adenosine and mitogen‐activated protein kinases (MAPKs) have been separately implicated in cardiac ischaemic preconditioning. We investigated the activation of MAPK subfamilies by adenosine in perfused rat hearts. p38‐MAPK was rapidly phosphorylated and activated (10‐fold activation, maximal at 5 min) by 10 mM adenosine, as was the p38‐MAPK substrate, MAPKAPK2 (4.5‐fold). SAPKs/JNKs were activated (5‐fold) and ERKs were phosphorylated (both maximal at 5 min). The concentration dependences of activation of p38‐MAPK and ERKs were biphasic with a ‘high affinity’ component (maximal at 10–100 μM adenosine) and a ‘low affinity’ component that had not saturated at 10 mM. SAPKs/JNKs were activated only by 10 mM adenosine. These results are consistent with MAPK involvement in adenosine‐mediated ischaemic preconditioning.
Molecular cloning and characterization of RBCK2, a splicing variant of a RBCC family protein, RBCK11
Authors: Tokunaga Chiharu , Tatematsu Kenji , Kuroda Shun'ichi , Nakagawa Noritaka , Kikkawa Ushio
Published: July 2002

RBCK1 (C protein interacting with PC 1) has two coiled‐coil regions, a RING finger, a B‐box and a B‐box‐like motif. RBCK2, a cDNA fragment related to RBCK1 was obtained, that lacks the 161‐bp sequence of RBCK1 and encodes 260 amino acid residues. The 240‐amino acid sequence in the NH2‐terminal of RBCK2 is identical with RBCK1 and contains two coiled‐coil regions but no other structural motifs, whereas the 20‐amino acid sequence in the COOH‐terminal is distinct from RBCK1. The analysis of genomic DNA revealed that RBCK1 and RBCK2 are generated from a single gene by alternative splicing. The RBCK1 protein interacted with the RBCK1 and RBCK2 proteins, but the RBCK2 protein did not interact with itself, in vitro. The RBCK2 protein fused with the DNA‐binding domain of yeast GAL4 (GAL4DBD) did not show a transcriptional activity, but the RBCK2 protein inhibited the transcriptional activity of the RBCK1 protein fused with GAL4DBD. These results suggest that RBCK2 may inhibit the transcriptional activity of RBCK1 probably through complex formation with RBCK1.
Lack of correlation between repair of DNA interstrand cross‐links and hypersensitivity of hamster cells towards mitomycin C and cisplatin
Authors: Larminat Florence , Cambois Gilles , Zdzienicka Małgorzata Z. , Defais Martine
Published: July 2002

The ability to repair DNA interstrand cross‐links may be an important factor contributing to mitomycin C (MMC) and cisplatin cytotoxicities. We have assessed the repair of interstrand cross‐links induced by MMC in two MMC‐hypersensitive hamster cell mutants and their resistant parental cell line. Using a gene‐specific repair assay, we found no evidence for repair of MMC cross‐links in either parental or mutant cells, suggesting that persistence of DNA interstrand cross‐links is not responsible for the differential toxicity of MMC towards hypersensitive cells. Repair of cisplatin‐induced interstrand cross‐links was efficient in resistant as well as in mutant cells. Therefore we concluded that a defect in excision repair of interstrand cross‐links was not responsible for the cytotoxic effects of MMC and cisplatin in these hypersensitive mutants.
GSTP1‐1 stereospecifically catalyzes glutathione conjugation of ethacrynic acid
Authors: van Iersel Marlou L.P.S , van Lipzig Marola M.H , Rietjens Ivonne M.C.M , Vervoort Jacques , van Bladeren Peter J
Published: July 2002

Using 1H NMR two diastereoisomers of the ethacrynic acid glutathione conjugate (EASG) as well as ethacrynic acid (EA) could be distinguished and quantified individually. Chemically prepared EASG consists of equal amounts of both diastereoisomers. GSTP1‐1 stereospecifically catalyzes formation of one of the diastereoisomers (A). The GSTP1‐1 mutant C47S and GSTA1‐1 preferentially form the same diastereoisomer of EASG as GSTP1‐1. Glutathione conjugation of EA by GSTA1‐2 and GSTA2‐2 is not stereoselective. When human melanoma cells, expressing GSTP1‐1, were exposed to ethacrynic acid, diastereoisomer A was the principal conjugate formed, indicating that even at physiological pH the enzyme catalyzed reaction dominates over the chemical conjugation.
cAMP‐dependent induction of PDE5 expression in murine neuroblastoma cell differentiation
Authors: Giordano D , Giorgi M , Sette C , Biagioni S , Augusti-Tocco G
Published: July 2002

The present study demonstrates, in both hybrid NG108‐15 and mouse neuroblastoma N18TG2 cells, the presence and regulation of PDE5 mRNA during cell differentiation. PDE5 cDNA probes in Northern blot analysis recognize a ∼9 kb transcript in bovine lung as well as in mouse neuroblastoma cells. Hybridization on total RNA extracted from dibutyryl‐cAMP‐treated NG108‐15 cells shows a 5‐fold increase of PDE5 9 kb mRNA: such an increase is not observed in N18TG2 although we observed a similar increase in the enzymatic activity of both cell lines. Our data demonstrate that PDE5 gene expression can be regulated by cAMP and suggest the existence of a complex regulatory system for PDE5 activity.
Characterization of the domains of E. coli initiation factor IF2 responsible for recognition of the ribosome
Authors: Moreno Juan Manuel Palacios , Dyrskjøtersen Lars , Kristensen Janni Egebjerg , Mortensen Kim Kusk , Sperling-Petersen Hans Uffe
Published: July 2002

We have studied the interactions between the ribosome and the domains of Escherichia coli translation initiation factor 2, using an in vitro ribosomal binding assay with wild‐type forms, N‐ and C‐terminal truncated forms of IF2 as well as isolated structural domains. A deletion mutant of the factor consisting of the two N‐terminal domains of IF2, binds to both 30S and 50S ribosomal subunits as well as to 70S ribosomes. Furthermore, a truncated form of IF2, lacking the two N‐terminal domains, binds to 30S ribosomal subunits in the presence of IF1. In addition, this N‐terminal deletion mutant IF2 possess a low but significant affinity for the 70S ribosome which is increased by addition of IF1. The isolated C‐terminal domain of IF2 has no intrinsic affinity for the ribosome nor does the deletion of this domain from IF2 affect the ribosomal binding capability of IF2. We conclude that the N‐terminus of IF2 is required for optimal interaction of the factor with both 30S and 50S ribosomal subunits. A structural model for the interaction of IF2 with the ribosome is presented.
High affinity interaction of HIV‐1 integrase with specific and non‐specific single‐stranded short oligonucleotides
Authors: Caumont Anne , Jamieson Gordon , de Soultrait Vaea Richard , Parissi Vincent , Fournier Michel , Zakharova Olga D. , Bayandin Roman , Litvak Simon , Tarrago-Litvak Laura , Nevinsky Georgy A.
Published: July 2002

Retroviral integrase (IN) catalyzes the integration of double‐stranded viral DNA into the host cell genome. The reaction can be divided in two steps: 3′‐end processing and DNA strand transfer. Here we studied the effect of short oligonucleotides (ODNs) on human immunodeficiency virus type 1 (HIV‐1) IN. ODNs were either specific, with sequences representing the extreme termini of the viral long terminal repeats, or non‐specific. All ODNs were found to competitively inhibit the processing reaction with K
i values in the nM range for the best inhibitors. Our studies on the interaction of IN with ODNs also showed that: (i) besides the 3′‐terminal GT, the interaction of IN with the remaining nucleotides of the 21‐mer specific sequence was also important for an effective interaction of the enzyme with the substrate; (ii) in the presence of specific ODNs the activity of the enzyme was enhanced, a result which suggests an ODN‐induced conformational change of HIV‐1 IN.
Oxythiamine and dehydroepiandrosterone induce a G1 phase cycle arrest in Ehrlich's tumor cells through inhibition of the pentose cycle
Authors: Raı̈s Badr , Comin Begoña , Puigjaner Joaquim , Brandes James L , Creppy Edmond , Saboureau Dominique , Ennamany Rachid , Paul Lee Wai-Nang , Boros Laszlo G , Cascante Marta
Published: July 2002

Transketolase (TK) reactions play a crucial role in tumor cell nucleic acid ribose synthesis utilizing glucose carbons, yet, current cancer treatments do not target this central pathway. Experimentally, a dramatic decrease in tumor cell proliferation after the administration of the TK inhibitor oxythiamine (OT) was observed in several in vitro and in vivo tumor models. Here, we demonstrate that pentose cycle (PC) inhibitors, OT and dehydroepiandrosterone (DHEA), efficiently regulate the cell cycle and tumor proliferation processes. Increasing doses of OT or DHEA were administered by daily intraperitoneal injections to Ehrlich's ascites tumor hosting mice for 4 days. The tumor cell number and their cycle phase distribution profile were determined by DNA flow histograms. Tumors showed a dose dependent increase in their G0‐G1 cell populations after both OT and DHEA treatment and a simultaneous decrease in cells advancing to the S and G2‐M cell cycle phases. This effect of PC inhibitors was significant, OT was more effective than DHEA, both drugs acted synergistically in combination and no signs of direct cell or host toxicity were observed. Direct inhibition of PC reactions causes a G1 cell cycle arrest similar to that of 2‐deoxyglucose treatment. However, no interference with cell energy production and cell toxicity is observed. PC inhibitors, specifically ones targeting TK, introduce a new target site for the development of future cancer therapies to inhibit glucose utilizing pathways selectively for nucleic acid production.
A cyclic nucleotide PDE5 inhibitor corrects defective mucin secretion in submandibular cells containing antibody directed against the cystic fibrosis transmembrane conductance regulator protein
Authors: McPherson Margaret A. , Pereira Malcolm M.C. , Lloyd Mills Chris , Murray Kenneth J. , Dormer Robert L.
Published: July 2002

A selective cyclic nucleotide PDE5 inhibitor corrected the defective mucin secretion response to the β‐agonist isoproterenol in submandibular acinar cells inhibited by antibody directed against the cystic fibrosis transmembrane conductance regulator. The PDE5 inhibitor was as effective as cpt‐cyclic AMP or a selective PDE4 inhibitor. However, the PDE5 inhibitor had no effect on basal or isoproterenol‐stimulated cyclic AMP levels and did not stimulate mucin secretion. The results showing, for the first time, correction of the CFTR mucin secretion defect by a PDE5 inhibitor, which may involve cyclic GMP, will have a major impact in development of a rational drug treatment for cystic fibrosis.
Nutritional interventions for the prevention of maternal morbidity
Authors: Kulier R. , de Onis M. , Gülmezoglu A.M. , Villar J.
Published: July 2002

Objective: To review the effectiveness of nutritional interventions to prevent maternal morbidity. Methods: This is an overview of systematic reviews and individual randomized controlled trials (if no systematic review available) of nutritional interventions during pregnancy. For each nutrient intervention the main maternal morbidity data reported were extracted. These were pre‐eclampsia/eclampsia, pregnancy‐induced hypertension, hemorrhage, anemia, infection and obstructed labor. In addition, the trial settings, the number of trials and participants' characteristics were systematically extracted. Results: The systematic reviews considered in this paper had only few trials that reported the selected maternal outcomes. Outcome measures are based sometimes on one trial only. Most of the interventions compared single micronutrient supplementation with placebo/no treatment and did not show significant benefits for the supplementation groups. Calcium supplementation in women at high risk of pregnancy hypertension reduced the incidence of high blood pressure (RR, 0.35; 95% CI, 0.21–0.57) and pre‐eclampsia (RR, 0.22; 95% CI, 0.11–0.43). Similarly, in women with low dietary calcium intake, calcium supplementation resulted in a significant reduction in the incidence of high blood pressure (RR, 0.49; 95% CI, 0.38–0.62) and pre‐eclampsia (RR, 0.32; CI, 0.21–0.49). In women at low risk of pregnancy hypertension or with adequate baseline calcium intake, the beneficial effects of calcium supplementation are small and unlikely to be of clinical significance. Both, iron and folate supplementation reduced the number of women with low pre‐delivery hemoglobin. Conclusions: Routine calcium supplementation seems to be a promising intervention for pregnant women at risk of developing preeclampsia or have low calcium intake, but these findings need to be confirmed with a trial with adequate power in different settings. In populations with high incidence of nutritional anemia routine iron and folate supplementation should be recommended during ante‐natal care. It is unclear at this stage if adding vitamin A to iron and folate supplementation in anemia prevalent areas provides further benefits. There is inadequate data on the benefits or harms of routine iron or folate supplementation in adequately nourished populations. With regard to other micronutrient supplementation, such as zinc, magnesium and fish oil, randomized controlled trials with sufficient power to detect clinically important differences in maternal and infant outcomes are needed.
Ca2+ oscillations and the cell cycle at fertilisation of mammalian and ascidian eggs
Authors: Nixon Victoria L. , McDougall Alex , Jones Keith T.
Published: July 2002

At fertilisation of mammalian and ascidian eggs the sperm induces a series of Ca2+ oscillations. These Ca2+ oscillations are triggered by a sperm‐borne Ca2+‐releasing factor whose identity is still unresolved. In both mammals and ascidians Ca2+ oscillations in eggs are associated with the period leading up to exit from meiosis and entry into the first embryonic cell cycle. Thus, in mammals Ca2+ oscillations continue for several hours but are complete by within 30 min in the ascidian. In mammals and ascidians Ca2+ oscillations stop at around the time when pronuclei form in the 1‐cell embryo. There is evidence to show that cell cycle factors are important in regulating the fertilisation Ca2+ signal. If the formation of pronuclei is blocked either in mammals (by spindle disruption) or in ascidians (by clamping maturation promoting factor levels high) then Ca2+ oscillations continue indefinitely. Here, we explore the nature of the sperm Ca2+‐releasing factor and examine the relationship between cell cycle resumption and the control of Ca2+ oscillations at fertilisation.
Expression of fructose‐1,6‐bisphosphatase mRNA isoforms in normal and basal forebrain cholinergic lesioned rat brain
Authors: Löffler Thomas , Al‐Robaiy Samiya , Bigl Marina , Eschrich Klaus , Schliebs Reinhard
Published: July 2002

Fructose‐1,6‐bisphosphatase is one of the key enzymes in the gluconeogenic pathway predominantly occurring in liver, kidney and muscle. In the brain, fructose‐1,6‐bisphosphatase has been suggested to be an astrocyte‐specific enzyme but the functional importance of glyconeogenesis in the brain is still unclear. To further elucidate the cellular source of fructose‐1,6‐bisphosphatase in the brain, non‐radioactive in situ hybridizations were performed using digoxigenin‐labeled RNA probes based on the sequence of recently cloned rat liver and muscle fructose‐1,6‐bisphosphatase cDNAs. In situ hybridization using a riboprobe for the liver isoform revealed a location of the hybridization signal mainly in neurons, while rat muscle fructose‐1,6‐bisphosphatase mRNA was detected in both neurons and astrocytes in the hippocampal formation and in layer I of the cerebral cortex.

RT‐PCR using RNA preparations of rat astrocytes, neurons, and adult whole brain demonstrated a localization of liver fructose‐1,6‐bisphosphatase mRNA isoform in neurons but not in astrocytes. The muscle fructose‐1,6‐bisphosphatase mRNA isoform could be detected by RT‐PCR in total rat brain, astrocytic, and neuronal mRNA preparations.

The isoforms of fructose‐1,6‐bisphosphatase mRNA seemingly demonstrate a distinct cellular expression pattern in rat brain suggesting a role of glyconeogenesis in both neurons and glial cells.
Cellular interactions as a response to injury in the organ of corti in culture
Authors: Sobkowicz H.M. , August B.K. , Slapnick S.M.
Published: July 2002

We discovered and described ultrastructurally the intricate relationships between the sensory cells and their supporting cells in cultures of the organ of Corti following laser beam irradiation. Injury was performed using a 440 nm nitrogen‐dye pulse laser aimed at the cuticular plates of inner hair cells. Laser injury is compared with mechanical injury inflicted on the hair cell region by a pulled‐glass pipette. Regardless of the type of injury, but depending on its severity, the surviving hair cells may: (1) lose their stereocilia but subsist at the surface of the organ; (2) retain contact with the reticular lamina but be overgrown by the processes of the supporting cells; or (3) become sequestered from the reticular lamina and internalized among the supporting cells, where they either remain dedifferentiated or regrow an apical process which regains contact with the surface of the organ. All supporting cells, including pillar and Deiters' cells, take part in wrapping their respective inner or outer hair cells. The supporting cells not only cover the injured sensory cells, but also invert their villi toward the maimed cuticular plates and release an extracellular matrix around them. We suggest that the supporting cells play a protective and trophic role in the recovery of injured hair cells.
NGF content in the cerebral cortex of non‐dementedpatients with amyloid‐plaques and in symptomaticALZHEIMER'S disease
Authors: Hellweg Rainer , Gericke Christian A. , Jendroska Klaus , Hartung Heinz‐dieter , Cervós‐Navarro Jorge
Published: July 2002

There is increasing evidence that in Alzheimers disease nerve growth factor (NGF)protein and NGF mRNA content in post‐mortem cortex is not decreased, but may evenbe elevated although the NGF‐sensitive cholinergic basal forebrain neurons are preferentiallyaffected. However, only little is known about the early pathophysiological events leading toAlzheimers disease. We therefore measured the post‐mortem NGF concentrations intemporal and frontal cortex of Alzheimers disease patients, non‐demented controls withoutAlzheimers disease‐related pathology, as well as non‐demented patients with βA4plaques who might be classified as preclinical cases. In the Alzheimers disease group we found upto 43% increase in NGF concentrations in the frontal and temporal cortex as compared to the twoother groups. In a subgroup analysis of the non‐demented patients with plaques, NGFconcentrations were lower in the frontal cortex when βA4 plaques were present (46% ofthe control temporal area) than in patients without evidence of frontal plaques (81% of the controltemporal area). This NGF decrease was paralleled to a similar decrease of cholineacetyltransferase activity, which is regulated by NGF in the cholinergic basal forebrain. Thesefindings support the hypothesis of lower cortical NGF content at the onset of plaque formationand of elevated NGF levels in the clinically manifest and neuropathologically advanced stage ofthe disease.
Validation of an echocardiographic wall motion index in heart failure due to ischaemic heart disease
Authors: McGowan J.H. , Martin W. , Burgess M.I. , McCurrach G. , Ray S.G. , McDonagh T.A. , Cleland J.G.F.
Published: July 2002

Aims:

the echocardiographic assessment of left ventricular ejection fraction (LVEF) by geometric methods is limited in many patients because of inadequate views and also in the presence of regional wall motion abnormalities due to ischaemic heart disease (IHD). This study aimed to examine the application of a wall motion index (WMI) method, using a nine‐segment LV model in patients with chronic heart failure (CHF) due to IHD.

Methods and Results:

echocardiography was performed in 71 consecutive subjects with CHF due to IHD. WMI could be derived in 70 subjects (99%). The inter‐observer variability (repeatability coefficient) of WMI was 0.66, i.e. LVEF±20%. In 66 subjects, LVEF was measured, within 4 weeks, using radionuclide ventriculography (RNV‐EF). The inter‐observer variability of RNV‐EF was ±3.1%. Using the mean of two observations for each method, the Bland–Altman range of agreement for LVEF was 26% (±13%).

Conclusion:

WMI is a widely applicable echocardiographic method for assessing LV systolic function and has moderate agreement with RNV‐EF. Unlike RNV‐EF, however, WMI is not likely to be a suitable method for the measurement of small, but prognostically important, changes in LV function that may occur in CHF.
KEEPING MAMMOGRAPHY REFERRAL APPOINTMENTS: MOTIVATION, HEALTH BELIEFS, AND ACCESS BARRIERS EXPERIENCED BY OLDER MINORITY WOMEN
Authors: Bernstein Judith , Mutschler Phyllis , Bernstein Edward
Published: July 2002

Older women of color tend to have much lower rates of regular mammography screening for breast cancer than younger Caucasian women; yet, they have higher rates of mortality. This study was designed to increase mammography rates among inner‐city women aged 50 years or older. Another goal was to investigate differences in mammography utilization related to race/ethnicity and language after barriers associated with cost and the difficulty of making an appointment are removed. A peer delivered intervention, which consisted of interview, mammography referral, and the scheduling of a next‐day appointment, was conducted among a convenience sample of 151 culturally and racially diverse older women through a primary care referral project operating within an urban emergency department (ED). A brief motivational interview and mammography referral at the time of an ED visit, including scheduling of a next‐day no cost appointment, was followed by a cross‐sectional telephone survey of utilization and motivating and hindering factors. Follow‐up was achieved with 96 women (66%). Fifty‐eight women (60%) had a post‐intervention mammogram; of those, 69% were first time users. More than 90% planned a repeat mammogram the following year. Of the 27 who did not receive a mammogram, 21 (77%) requested a “second try” appointment. These findings demonstrate that an interactive intervention among older women of color has the potential to dramatically increase mammography rates.
Dynamic Control of Orthogonal Upconversion in Migratory Core–Shell Nanostructure toward Information Security
Authors: Huang Jinshu , Yan Long , Liu Songbin , Song Nan , Zhang Qinyuan , Zhou Bo
Published: February 2021

Lanthanide‐based materials exhibit abundant emission colors under suitable infrared excitations; however, the dynamic control of orthogonal photon upconversion of lanthanide ions has remained challenging. Here, a novel mechanistic strategy to enable orthogonal upconversion emissions through energy migration in a simple core–shell nanostructure is reported. By constructing the migratory ytterbium‐sublattice shell layer outside the luminescent erbium matrix, the population of erbium emitters at their intermediate energy levels can be finely manipulated, and the red‐to‐green color‐switchable output has been achieved under separate 980 and 808 (or 1530) nm excitations. More interestingly, a tuning of the excitation pulse width also results in a gradual red‐to‐green color change. The mechanistic role of energy migration over ytterbium sublattice is also examined. A conceptual core–shell model for the excitation‐emission orthogonal upconversion output is provided, which is not only important for the fundamental research of photon upconversion but also helps in exciting new chances for the frontier applications such as information security.
Lithiophilic and Antioxidative Copper Current Collectors for Highly Stable Lithium Metal Batteries
Authors: Fu Ang , Wang Chaozhi , Peng Jian , Su Min , Pei Fei , Cui Jingqin , Fang Xiaoliang , Li Jian‐Feng , Zheng Nanfeng
Published: February 2021

Designing copper (Cu) current collectors is a convenient way to stabilize lithium (Li) metal anodes. However, Cu current collectors and their derived Li/Cu anodes still face several obstacles, including lithiophobic and oxidizable Cu surface, cumbersome anode fabrication process, and low Li utilization. Here, a formate‐treatment strategy is presented to reconstruct Cu current collectors with a passivation layer covered Cu(110) surface. This method can easily be generalized to increase the lithiophilicity and oxidation resistibility of Cu current collectors. Using the formate‐treated Cu nanowire network as an anode current collector, the full cell consisting of a LiFePO4 cathode and Li/Cu anode with a low negative/positive capacity ratio delivers an excellent cycling performance with 74.8% capacity retention after 1000 cycles at 1 C. In addition, a concept of an upper current collector is introduced to simplify the manufacturing procedure of Li/Cu anodes. This work provides new insights into the design and construction of high‐performance Li/Cu anodes.
Characterization of Hierarchically Ordered Porous Materials by Physisorption and Mercury Porosimetry—A Tutorial Review
Authors: Schlumberger Carola , Thommes Matthias
Published: February 2021

This paper is devoted to the textural characterization of nanoporous materials with a focus on hierarchically ordered materials such as mesoporous zeolites, which exhibit an interconnected pore network consisting of micro‐, meso‐, and often macropores. Hierarchically ordered zeolites have the potential to improve various industrial applications for instance in the areas of heterogeneous catalysis, separation, gas, and energy storage. Detailed insights into the pore architecture are important, because they control transport phenomena, diffusional rates, and govern selectivity, e.g. in catalyzed reactions. However, a reliable characterization of such complex pore structures is still a major challenge. Within this context, the application of advanced physisorption methodologies for micro‐mesopore analysis is discussed but also the characterization of macroporosity by mercury porosimetry is addressed. Fundamental concepts and recent major advances in understanding the underlying mechanisms are highlighted. In conjunction with selected case studies, it is illustrated how the application of advanced physisorption methodologies allows i) for the determination of reliable surface areas, pore volumes, and pore size distributions and ii) for obtaining information about pore network characteristics. This tutorial offers guidance for an advanced characterization of nanoporous materials by physisorption and mercury intrusion/extrusion.
How corporate social responsibility influences consumer behavior: An empirical analysis in the Spanish agrifood sector
Authors: Mercadé‐Melé Pere , Fandos‐Herrera Carmina , Velasco‐Gómez Sofía
Published: February 2021

This study analyzes how corporate social responsibility (CSR) influences consumer behavior in the case of the Spanish agrifood sector. The originality of the study resides in the proposed model that explains that CSR influences perceptions of food safety and health, and quality, and that this perceived quality influences consumer behavior, that is, satisfaction and loyalty. Structural equation modeling was used to analyze the data from 295 personal interviews; satisfactory results were obtained for all the proposed relationships. Therefore, we suggest that, to achieve consumer loyalty, agrifood companies should orient their strategies toward creating sustainable relationships based on CSR actions. Other academic and management implications are proposed to complete the paper. [EconLit Citations: M14, M310, Q13].
Alazami syndrome: Report of three Indian patients with phenotypic spectrum from adolescence to adulthood
Authors: Das Sweta , Godbole Koumudi , Abraham Suneetha Susan Cleave , Ganesan Paramasivam , Kamdar Payal , Danda Sumita
Published: February 2021

Alazami syndrome (ALAZS) (MIM 615071) is a rare autosomal recessive disorder characterized by short stature, dysmorphic facial features, developmental delay, and impaired intellect. It was first reported in a Saudi Arabian family in 2012. Three Indian patients affected with ALAZS, one boy aged 13 years and other two sisters in their 40s are presented. These patients had few unreported dysmorphic facial features: high arched eyebrows and dental overcrowding. No microcephaly was noted in the sisters. One of the sisters did not have short stature. The boy also presented with unilateral buphthalmos of left eye. All three of them have been identified to harbor novel variants in LARP7.
Asymmetric Coordination Toward a Photoinduced Single‐Chain Magnet Showing High Coercivity Values
Authors: Liu Qiang , Hu Ji‐Xiang , Meng Yin‐Shan , Jiang Wen‐Jing , Wang Jun‐Li , Wen Wen , Wu Qiong , Zhu Hai‐Lang , Zhao Liang , Liu Tao
Published: February 2021

The production of photo‐switchable molecular nanomagnets with substantial coercivity, which is indispensable for information storage and process applications, is challenging. Introducing photo‐responsive spin‐crossover units provides a feasible means of controlling the magnetic anisotropy, interactions, and overall nanomagnet properties. Herein, we report a cyanide‐bridged chain 1⋅12H2O ({[(PzTp)FeIII(CN)3]2FeII(Pmat)2}n⋅12 H2O) generated by linking the FeII‐based spin‐crossover unit with the [(PzTp)Fe(CN)3]− (PzTp: tetrakis(pyrazolyl)borate) building block in the presence of asymmetric ditopic ligand Pmat ((4‐pyridine‐4‐yl)methyleneamino‐1,2,4‐triazole). Structural characterization revealed that the introduction of this asymmetric ligand led to a distorted coordination environment of FeII ions, which were equatorially coordinated by four cyanide N atoms, and apically coordinated by one pyridine N atom and one triazole N atom. Upon 808‐nm light irradiation, 1⋅12H2O underwent photoinduced spin‐crossover and exhibited single‐chain magnet behavior with a coercive field of up to 1.3 T. This represents a 3d‐based photoinduced single‐chain magnet exhibiting pronounced hysteresis.