bluuebunny/crossref_metadata_2025 huggingface dataset:
Penicillin binding protein 2x as a major contributor to intrinsic β‐lactam resistance of Streptococcus pneumoniae
Authors: Jamin Marc , Hakenbeck Regine , Frere Jean-Marie
Published: July 2002

The production and purification to protein homogeneity of a soluble form of PBP2x from a cefotaxime‐resistant Streptococcus pneumoniae strain is reported. It was obtained by a site‐directed deletion of the membrane anchor in the corresponding gene, a method similar to that successfully utilized for the production of PBP2x from a cefotaxime‐sensitive wild type strain [1]. The kinetic parameters characterizing the interactions of both cefotaxime‐resistant and ‐sensitive proteins have been determined and compared. The results are in agreement with the identification of PBP2x as the primary target for cefotaxime in the sensitive strain and as probably one of several targets in the resistant strain.
The GP‐protein of Marburg virus contains the region similar to the ‘immunosuppressive domain’ of oncogenic retrovirus P15E proteins
Authors: Bukreyev A.A. , Volchkov V.E. , Blinov V.M. , Netesov S.V.
Published: July 2002

cDNA was synthesized and cloned on the template of the genomic RNA of Marburg virus (strain Popp). Recombinant plasmids with specific cDNA inserts were selected and sequenced. The length of the open reading frame encoding the GP‐protein is 681 amino acids. GP‐protein is proposed to be an integral membrane protein. Computer‐assisted comparison of the deduced amino acid sequence with those of different viruses revealed significant homology with the GP‐protein of Ebola virus and with the ‘immunosuppressive domain” of the P15E envelope proteins of some oncogenic retroviruses.
Intracellular dynamics of ricin followed by fluorescence microscopy on living cells reveals a rapid accumulation of the dimeric toxin in the Golgi apparatus
Authors: Lendaro Eugenio , Ippoliti Rodolfo , Bellelli Andrea , Brunori Maurizio , Evangelista Valtere , Guidarini Dante , Benedetti Pier Alberto
Published: July 2002

The intracellular dynamics of fluorescent conjugates of the toxic lectin ricin was followed by video fluorescence microscopy on living CHO cells, demonstrating that the ricin heterodimer and its isolated B chain, after binding to the plasma membrane receptors, migrate to and accumulate in the Golgi apparatus following internalization. A ricin derivative labelled with fluorescein on the A chain and rhodamine on the B chain did not display significant splitting of the A‐B heterodimer during translocation of the toxin to the Golgi; this novel finding provides support for the hypothesis that further processing of ricin takes place in this cellular compartment.
ATP/ADP antiporter is involved in uncoupling of plant mitochondria induced by low concentrations of palmitate
Authors: Vianello A. , Petrussa E. , Macrì F.
Published: July 2002

Carboxyatractyloside partially restored the transmembrane electrical potential difference (ΔΨ) dissipated by low concentrations of palmitate in pea stem mitochondria. This effect was more marked when mitochondria from sunflower were assayed. It is suggested that the ATP/ADP translocator is involved in the free fatty acid‐induced uncoupling of oxidative phosphorylation in plant mitochondria, only when its level is sufficiently high and the concentration of the fatty acid is low to collapse only partially the ΔΨ.
Purification of FKBP‐70, a novel immunophilin from Saccharomyces cerevisiae, and cloning of its structural gene, FPR3
Authors: Manning-Krieg Ute C. , Henríquez Rubén , Cammas Florence , Graff Patrick , Gavériaux Samuel , Movva N.Rao
Published: July 2002

A novel protein, belonging to the yeast family of FKBPs (FK‐binding proteins), FKBP‐70, was isolated from Saccharomyces cerevisiae by its interaction with the immunosuppressive agent FK‐520. Its structural gene, FPR3, was cloned and the protein expressed and purified from Escherichia coli. This third member of the FKBP family in yeast is homologous to the other FKBPs at its carboxy terminus, showing conserved ligand binding and proline isomerase regions. It is, however,a longer acidic protein with several potential nuclear targeting sequences and a region of homology to nucleolins. Yeast strains deleted for FPR3, as well as a triple deletion mutant of this family of genes, FPR1, FPR2 and FPR3, are viable under normal conditions of growth, indicating that the FPR genes are not essential for life.
On the site by which α‐dendrotoxin binds to voltage‐dependent potassium channels: Site‐directed mutagenesis reveals that the lysine triplet 28–30 is not essential for binding
Authors: Danse Jean Marc , Rowan Edward G. , Gasparini Sylvaine , Ducancel Frédéric , Vatanpour Hossein , Young Louise C. , Poorheidari Grolamrize , Lajeunesse Evelyne , Drevet Pascal , Ménez Renée , Pinkasfeld Suzanne , Boulain Jean-Claude , Harvey Alan L. , Ménez André
Published: July 2002

We constructed a synthetic gene encoding the published amino acid sequence of DTx from Dendroaspis angusticeps, a ligand of voltage‐dependent postassium channels that facilitates neurotransmitter release. We expressed it in Escherichia coli as a fusion protein secreted in the culture medium. The recombinant DTx was generated in vitro by chemical treatment and recovered as two isoforms. One of them (rDTx), like the venom toxin, has an N‐terminal pyroglutamate whereas the other (rQDTx) has a free N‐terminal glutamine. Chromatographic differences between rDTx and natural DTx led us to re‐examine the amino acid sequence of natural DTx. In contrast to what was previously published, position 12 was an Asp and not Asn. Despite this difference, rDTx and DTx had similar toxicity in mice and binding affinity to synaptosomes, suggesting that residue 12 is not important for DTx function. Nor is the N‐terminal residue implicated in DTx function since rDTx and rQDTx also had similar biological activities. We also synthesized and expressed a mutant of the DTx gene in which the lysine triplet 28–30 was changed into Ala‐Ala‐Gly. The two resulting recombinant isoforms exhibited only small decreases in biological activity, excluding the possibility that the positively charged lysine triplet 28–30 of DTx is directly involved in the toxin functional site.
Detection of 4'‐phosphopantetheine at the thioester binding site for l‐valine of gramicidinS synthetase 2
Authors: Stein Torsten , Vater Joachim , Kruft Volker , Wittmann-Liebold Brigitte , Franke Peter , Panico Maria , Dowell Roy Mc , Morris Howard R.
Published: July 2002

Biosynthesis of gramicidinS in Bacillus brevis is catalysed by a multienzyme system consisting of two multifunctional proteins, gramicidinS synthetase 1 and 2 codified by the grsA and grsB genes, respectively. GramicidinS synthetase 2 shows a modular architecture of four amino acid‐activating domains each containing a thioester binding motif LGG H/D S L/I highly conserved in its C‐terminal region, as demonstrated by sequence analysis of the grsB gene [W. Schlumbohm et al. (1991) J. Biol. Chem. 266, 23135‐23141]. This multienzyme was specifically labeled at the thioester binding site of l‐valine with [3H]N‐ethylmaleimide using a substrate protection technique. After enzymatic digestion a labeled active site peptide was isolated in pure form by multistep methodology. This fragment was identified by gas‐phase sequencing as the active site peptide of the thiotemplate site for l‐Val by comparison with the grsB gene sequence. By mass spectrometry in combination with amino acid analysis it was demonstrated that a 4'‐phosphopantetheine carrier was attached to the active serine in this motif. Our results give evidence that multiple peripheral 4'‐phosphopantetheine carriers are involved in the formation of gramicidinS in contrast to a central carrier arm as assumed in the original version of the thiotemplate mechanism. A ‘Multiple Carrier Model’ of nonribosomal peptide biosynthesis is proposed.
A sialic acid‐binding lectin from the mushroom Hericium erinaceum
Authors: Kawagishi Hirokazu , Mori Hironobu , Uno Akinori , Kimura Atsuo , Chiba Seiya
Published: July 2002

A lectin was isolated from the mushroom Hericium erinaceum. This lectin is composed of two different subunits of 15 and 16 kDa and the molecular mass of the intact lectin was estimated to be 54 kDa by gel filtration. It exhibits specificity towards sialic acids, especially N‐glycolylneuraminic acid.
Patch‐clamp study of liver nuclear ionic channels reconstituted into giant proteoliposomes
Authors: Guihard Gilles , Proteau Sonia , Payet Marcel Daniel , Escande Denis , Rousseau Eric
Published: July 2002

Nuclear ionic channels (NICs) represent ubiquitous structures of living cells, although little is known about their functional properties and encoding genes. To characterize NICs, liver nuclear membrane vesicles were reconstituted into either planar lipid bilayers or proteoliposomes. Reconstitution of nuclear envelope (NE) vesicles into planar lipid bilayer proceeded with low efficiency. NE vesicle reconstitution into proteoliposomes led to NIC observations by the patch‐clamp technique. Large conductance, voltage‐gated, K+‐permeant and Cl−‐permeant NICs were characterized. An 80–105‐pS K+‐permeant NIC with conducting sub‐state was also recorded. Our data establish that NICs can be characterized upon reconstitution into giant proteoliposomes and retain biophysical properties consistent with those described for native NICs.
Propensities for the formation of individual disulfide bonds in hen lysozyme and the size and stability of disulfide‐associated submolecular structures
Authors: Tachibana Hideki
Published: July 2002

Hen lysozyme single‐disulfide variants were constructed to characterize the structures associated with the formation of individual native disulfide bonds. Circular dichroism spectra and the effective concentration of protein thiol groups showed that the propensity for structure formation was relatively high for Cys‐6–Cys‐127 and Cys‐30–Cys‐115 disulfides. The urea concentration dependence of individual effective concentrations showed that the apparent sizes of the structures were 14–50% of the whole molecule. The intrinsic stability of each submolecular structure in a reduced form of protein, obtained by subtracting the entropic contribution of cross‐linking, was highest for Cys‐64–Cys‐80 and lowest for Cys‐76–Cys‐94 disulfide bonds.
Transcriptomes, transcription activators and microarrays
Authors: Devaux Frédéric , Marc Philippe , Jacq Claude
Published: July 2002

Gene‐specific transcription activators are among the main factors which specifically shape the transcriptome profiles. It is tempting to take advantage of their properties to decipher the genome expression circuitry. The advent of microarray technology has offered fantastic opportunities to quickly analyze the expression profiles dictated by specific transcription factors. This review will first focus on the strategies which have been devised to control the activity of transcription factors and in the second part on the microarray experiments which addressed the role of these transcription factors in the genome‐wide expression profile. This last part will mainly consider the case of the yeast Saccharomyces cerevisiae genome. All the collected data are available through the on‐line database yTAFNET (http://transcriptome.ens.fr/ytafnet/). yTAFNET is designed to help the characterization of connections between the different yeast regulatory networks.
The recombinant catalytic domain of membrane‐type matrix metalloproteinase‐1 (MT1‐MMP) induces activation of progelatinase A and progelatinase A complexed with TIMP‐2
Authors: Lichte Andrea , Kolkenbrock Hansjörg , Tschesche Harald
Published: July 2002

A truncated form of the membrane‐type matrix metalloproteinase‐1 [(Ala21‐Ile318)proMT1‐MMP] lacking the hemopexin‐like and trans‐membrane domain was produced in E. coli. We demonstrate that the recombinant proenzyme was autoproteolytically processed to a fully active catalytic domain with N‐terminal Ile114. The catalytic domain of MT1‐MMP initiated the activation of progelatinase A and progelatinase A complexed with tissue inhibitor of metalloproteinases‐2 (TIMP‐2). As a typical soluble metalloproteinase it was able to cleave physiologic as well as synthetic substrates. Our kinetic data demonstrate that TIMP‐2 is a potent inhibitor for the recombinant enzyme.
Amino acids of the α1B‐adrenergic receptor involved in agonist binding: differences in docking catecholamines to receptor subtypes
Authors: Cavalli Antonella , Fanelli Francesca , Taddei Carlo , De Benedetti Pier G. , Cotecchia Susanna
Published: July 2002

Site‐directed mutagenesis and molecular dynamics analysis of the 3‐D model of the α
1B
‐adrenergic receptor (AR) were combined to identify the molecular determinants of the receptor involved in catecholamine binding. Our results indicate that the three conserved serines in the fifth transmembrane domain (TMD) of the α
1B‐AR play a distinct role in catecholamine binding versus receptor activation. In addition to the amino acids D125 in TMDIII and S207 in TMDV directly involved in ligand binding, our findings identify a large number of polar residues playing an important role in the activation process of the α
1B‐AR thus providing new insights into the structure/function relationship of G protein‐coupled receptors.
Production of a soluble and active MBP‐scFv fusion: favorable effect of the leaky tolR strain
Authors: Chames Patrick , Fieschi Jacques , Baty Daniel
Published: July 2002

The 6D6 anti‐cortisol scFv was prepared as fusion protein with maltose‐binding protein (MBP) to increase the amount of soluble product. This fusion was almost completely insoluble when produced in a wild‐type strain of Escherichia coli. However, when MBP‐scFv fusion was produced in a tolR leaky strain, it was secreted into the culture medium as an active, soluble protein. Production of recombinant proteins in the tolR strain greatly enhances the recovery of active protein and may be a useful system to produce MBP fusion proteins that would normally aggregate when produced in wild‐type bacterial strains. © 1997 Federation of European Biochemical Societies
Determination of DMPC hydration in the Lαand Lβ′phases by2H solid state NMR of D2O
Authors: Faure Chrystel , Bonakdar Lida , Dufourc Erick J
Published: July 2002

The number of water molecules bound to the dimyristoylphosphatidylcholine (DMPC) interface was investigated both in the fluid (Lα) and gel (Lβ′) phases by solid state deuterium NMR of D2O. We determined that each DMPC molecule binds 9.7±0.5 and less than 4.3±0.5 D2O in the fluid and gel phases respectively. These results are accounted for by considering the number of DMPC binding sites as well as the molecular organization in each phase. © 1997 Federation of European Biochemical Societies.
The F420H2:heterodisulfide oxidoreductase system from Methanosarcina species
Authors: Bäumer Sebastian , Murakami Eisuke , Brodersen Jens , Gottschalk Gerhard , Ragsdale Stephen W , Deppenmeier Uwe
Published: July 2002

F420H2‐dependent CoB‐S‐S‐CoM reduction as catalyzed by the F420H2:heterodisulfide oxidoreductase from Methanosarcina strains was observed in a defined system containing purified F420H2 dehydrogenase from Methanosarcina mazei Gö1, 2‐hydroxyphenazine and purified heterodisulfide reductase from Methanosarcina thermophila. The process could be divided into two partial reactions: (1) reducing equivalents from F420H2 were transferred to 2‐hydroxyphenazine by the F420H2 dehydrogenase with a V
max value of 12 U/mg protein; (2) reduced 2‐hydroxyphenazine acted as electron donor for CoB‐S‐S‐CoM reduction as catalyzed by the heterodisulfide reductase. The specific activity was 14–16 U/mg protein at 37°C and 60–70 U/mg protein at 60°C. The partial reactions could be combined in the presence of both enzymes. Under these conditions reduced 2‐hydroxyphenazine was rapidly oxidized by the heterodisulfide reductase thereby producing the electron acceptor for the F420H2 dehydrogenase. Above a concentration of 50 μM of 2‐hydroxyphenazine, the specific activity of the latter enzyme reached the V
max value. When other phenazines or quinone derivatives were used as electron carriers, the activity of F420H2‐dependent CoB‐S‐S‐CoM reduction was much lower than the rate obtained with 2‐hydroxyphenazine. Thus, this water‐soluble analogue of methanophenazine best mimics the natural electron acceptor methanophenazine in aqueous systems.
Hypoxia induces apoptosis in human neuroblastoma SK‐N‐MC cells by caspase activation accompanying cytochrome c release from mitochondria
Authors: Araya Runa , Uehara Takashi , Nomura Yasuyuki
Published: July 2002

We have attempted to elucidate the mechanism of apoptotic cell death induced by hypoxia (very low oxygen conditions) in neuronal cells. Human neuroblastoma SK‐N‐MC cells under hypoxic conditions resulted in apoptosis in a time‐dependent manner estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent chromatin dye. Pretreatment with Z‐Asp‐CH2‐DCB, a caspase inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration‐dependent manner. An increase in caspase‐3‐like protease (DEVDase) activity was observed during apoptosis, but no caspase‐1 activity (YVADase) was detected. To confirm the involvement of caspase‐3 during apoptosis, Western blot analysis was performed using anti‐caspase‐3 antibody. The 20‐ and 17‐kDa proteins, corresponding to the active products of caspase‐3, were generated in hypoxia‐challenged lysates in which processing of the full length form of caspase‐3 was evident. With a time course similar to this caspase‐3 activation, hypoxic stress caused the cleavage of PARP, yielding an 85‐kDa fragment typical of caspase activity. In addition, caspase‐2 was also activated by hypoxia, and the stress elicited the release of cytochrome c into the cytosol during apoptosis. These results suggest that caspase activation and cytochrome c release play roles in hypoxia‐induced neuronal apoptosis.
A comparative study of two retaining enzymes of Trichoderma reesei: transglycosylation of oligosaccharides catalysed by the cellobiohydrolase I, Cel7A, and the β‐mannanase, Man5A
Authors: Harjunpää Vesa , Helin Jari , Koivula Anu , Siika-aho Matti , Torbjörn Drakenberg
Published: July 2002

HPLC, MALDI‐TOF MS and NMR spectroscopy were used to investigate the hydrolysis of cello‐ and manno‐oligosaccharides by Cel7A and Man5A from Trichoderma reesei. The experimental progress curves were analysed by fitting the numerically integrated kinetic equations, which provided cleavage patterns for oligosaccharides. This data evaluation procedure accounts for product inhibition and avoids the initial slope approximation. In addition, a transglycosylation step had to be included in the model to reproduce the experimental progress curves. For the hydrolysis of manno‐oligosaccharides, Man4–6, by Man5A no mannose was detected at the beginning of the reaction showing that only the internal linkages are hydrolysed. For cellotriose and cellotetraose hydrolysis by Cel7A, the main product is cellobiose and glucose is released from the non‐reducing end of the substrate. Intermediary products longer than the substrates were detected by MALDI‐TOF MS when oligosaccharides (Glc4–6 or Man4–6) were hydrolysed by either Cel7A or Man5A. Interestingly, two distinct transglycosylation pathways could be observed. Cel7A produced intermediates that are one unit longer than the substrate, whereas Man5A produced intermediates that are two units longer than the substrate.
NMR structure of the mature dimer initiation complex of HIV‐1 genomic RNA
Authors: Mujeeb Anwer , Parslow Tristram G. , Zarrinpar Ali , Das Chandreyee , James Thomas L.
Published: July 2002

The two identical genomic RNA strands inside each HIV‐1 viral particle are linked through homodimerization of an RNA stem‐loop, termed SL1, near their 5′ ends. SL1 first dimerizes through a palindromic sequence in its loop, forming a transient kissing‐loop complex which then refolds to a mature, linear duplex. We previously reported the NMR structure of a 23‐base truncate of SL1 in kissing‐dimer form, and here report the high‐resolution structure of its linear isoform. This structure comprises three short duplex regions – derived from the central palindrome and two stem regions of each strand, respectively – separated by two bulges that each encompass three unpaired adenines flanking the palindromes. The stacking pattern of these adenines differs from that seen in the kissing‐loop complex, and leads to greater colinear base stacking overall. Moreover, the mechanical distortion of the palindrome helix is reduced, and base pairs ruptured during formation of the kissing‐loop complex are re‐established, so that all potential Watson‐Crick pairs are intact. These features together likely account for the greater thermodynamic stability of the mature dimer as compared to its kissing‐loop precursor.
CDC25Mm/Ras‐GRF1 regulates both Ras and Rac signaling pathways
Authors: Innocenti Metello , Zippel Renata , Brambilla Riccardo , Sturani Emmapaola
Published: July 2002

The Ras‐GRF1 exchange factor molecule contains in addition to the catalytic domain two pleckstrin homology (PH1 and PH2), one IQ and one Dbl homology (DH) domains. In this study we investigated the role of such additional domains. We found that a Ras‐GRF1 mutant lacking PH1 and IQ domains is sufficient to activate c‐fos promoter in response to lysophosphatidic acid (LPA). The same mutant did not increase external stimuli‐regulated kinase (ERK) activity, suggesting an additional mechanism for the induction of gene transcription. Isolated DH‐PH2 module activates c‐Jun NH2‐terminal kinase and the c‐fos promoter in response to LPA, providing the basis for an ERK‐independent mechanism. These results provide evidence that Ras‐GRF1 acts as a bifunctional molecule on both ERK‐dependent and independent pathways.
Polycystic ovarian syndrome (PCOS) and insulin resistance
Authors: Park K.H , Kim J.Y , Ahn C.W , Song Y.D , Lim S.K , Lee H.C
Published: July 2002

Objectives: Polycystic ovary syndrome (PCOS) presents a high risk of developing type 2 diabetes mellitus. We studied a group of women with PCOS and evaluated this defect in insulin action. Methods: The study population consisted of nine PCOS women, six obese type 2 diabetic patients, and five controls whose body mass index (BMI) was similar to that of the nine PCOS women. The 75‐g oral glucose tolerance test (OGTT) and the hyperinsulinemic euglycemic glucose clamp test were performed. Clinical characteristics and the metabolic profiles, including the insulin sensitivity index (ISI), were compared. Results: PCOS women showed significantly elevated insulin responses during OGTT, but their blood glucose levels were comparable with the controls. The subjects with PCOS had more insulin resistance than the other groups. There was no difference among the groups in terms of clinical characteristics and metabolic profiles, except age, luteinzing hormone (LH), testosterone, and sex hormone binding globulin (SHBG). Conclusion: We conclude that PCOS women have significant insulin resistance which is independent of adiposity.
Single dose methotrexate therapy: application to interstitial ectopic pregnancy
Authors: Borgatta L , Burnhill M , Stubblefield P
Published: July 2002

A woman with a small (6‐mm gestational sac) interstitial pregnancy had complete resolution after medical therapy alone. A single cycle of methotrexate 50 mg/m2 was used as outpatient treatment without any operative procedure either for diagnosis or intervention. The guidelines that have evolved for selection of women for single dose methotrexate treatment for both intrauterine and tubal ectopic pregnancies may be applicable to interstitial ectopic pregnancy as well. A suggested framework for treatment decisions is presented.
Dynamic changes in microtubule organization during division of the primitive dinoflagellate Oxyrrhis marina
Authors: Kato Koichi H. , Moriyama Akihiko , Itoh Tomohiko J. , Yamamoto Masayuki , Horio Tetsuya , Huitorel Philippe
Published: July 2002

Summry— The marine dinoflagellate Oxyrrhis marina has three major microtubular systems: the flagellar apparatus made of one transverse and one longitudinal flagella and their appendages, cortical microtubules, and intranuclear microtubules. We investigated the dynamic changes of these microtubular systems during cell division by transmission and scanning electron microscopy, and confocal fluorescent laser microscopy. During prophase, basal bodies, both flagella and their appendages were duplicated. In the round nucleus situated in the cell centre, intranuclear microtubules appeared radiating toward the centre of the nucleus from densities located in some nuclear pores. During metaphase, both daughter flagellar apparatus separated and moved apart along the main cell axis. Microtubules of ventral cortex were also duplicated and moved with the flagellar apparatus. The nucleus flattened in the longitudinal direction and became discoid‐shaped close to the equatorial plane. Many bundles of microtubules ran parallel to the short axis of the nucleus (cell long axis), between which chromosomes were arranged in the same direction. During ana—telophase, the nucleus elongated along the longitudinal axis and took a dumbbell shape. At this stage a contractile ring containing actin was clearly observed in the equatorial cortex. The cortical microtubule network seemed to be cut into two halves at the position of the actin bundle. Shortly after, the nucleus divided into two nuclei, then the cell body was constricted at its equator and divided into one anterior and one posterior halves which were soon rebuilt to produce two cells with two full sets of cortical microtubules. From our observations, several mechanisms for the duplication of the microtubule networks during mitosis in O. marina are discussed.
Medical ethics and the judicial coerced treatment of sexual abusers
Authors: Cosyns P
Published: July 2002

The increasing demand for judicial coerced treatment of sexual abusers constitutes a new challenge for mental health professionals. The discussed controversial ethical issues are the influence of coercion on the treatment, the motivation of patient as well as therapist, confidentiality and hormonal treatment. Social control is not the primary concern of therapists and any treatment must be beneficial to the individual patient. The coerced treatment of sexual abusers requests an agreement between psychiatric and judicial authorities with respect for their respective professional ethics.
Plasma and pericardial fluid natriuretic peptide levels in postinfarction ventricular dysfunction
Authors: Klemola Rauli , Tikkanen Ilkka , Vuolteenaho Olli , Toivonen Lauri , Laine Mika
Published: July 2002

Aims:

In the present study we examined plasma and pericardial fluid ANP and BNP concentrations in postinfarction ventricular dysfunction. The association of peptide levels to left ventricular (LV) dysfunction and to the localization of the myocardial infarction (MI) was studied.

Methods and results:

Plasma and pericardial fluid samples were obtained from 37 patients undergoing coronary bypass surgery. According to the ECG and preceding coronary angiography, the patients were divided into three groups: previous anterior myocardial infarction (MI) (n = 12), previous inferior/posterior MI (n = 15) and no history of MI (n = 10). When compared to the control group with no MI, the patients with anterior MI had elevated plasma ANP and BNP (134 ± 13 vs. 81 ± 15 pg/ml, P < 0.01 and 95 ± 10 pg/ml vs. 26 ± 8 pg/ml, P < 0.01, respectively) and pericardial fluid BNP (473 ± 60 pg/ml vs. 57 ± 8 pg/ml, P < 0.001) levels. The plasma natriuretic peptide concentrations were not increased in the patients with inferior/posterior MI, but the pericardial fluid BNP concentrations were greater than in the patients with no history of MI (129 ± 35 pg/ml vs. 57 ± 8 pg/ml, P < 0.05). Six of the 12 patients with previous anterior MI had LVEF ≥ 45%. Despite their normal LV systolic function, these patients had increased plasma and pericardial fluid BNP levels when compared to the group with no history of MI (68 ± 18 pg/ml vs. 26 ± 8 pg/ml, P < 0.05 and 534 ± 258 pg/ml vs. 57 ± 8 pg/ml, P < 0.01, respectively).

Conclusions:

Previous anterior myocardial infarction was associated with increased cardiac BNP production even if the LV systolic function was normal (LVEF ≥ 45%). The high pericardial fluid BNP concentrations in postinfarction patients suggest that the BNP synthesis and release are augmented in the ventricular myocardium independent from the LVEF.
A “CONSERVATIVE” APPROACH TO IRON SUPPLEMENTATION DURING PREGNANCY
Authors: Graves Barbara W. , Barger Mary K.
Published: July 2002

A review of current knowledge about iron metabolism during pregnancy and the evidence from various studies on the effects of iron supplementation in pregnancy on maternal, fetal, and infant outcomes suggest that the implicit goal of current recommendations regarding iron supplementation may be to achieve the highest hemoglobin concentration possible. This goal is only weakly related to improved maternal and infant outcomes in the current pregnancy or to improved maternal iron stores long‐term. Indeed, the claim that iron supplementation is universally innocuous is shown to be controversial. For women in developed countries who are generally clinically healthy and have access to adequate nutrition, the benefits of iron supplementation are unclear, and there may be risks. Thus, a better “conservative” approach may be that such women do not require routine iron supplementation during pregnancy. The midwifery philosophy of individualizing care based on a woman's history and health status is one that should be taken in approaching the issue of iron supplementation in pregnancy.
Comparison of asymptotic population growth rates with heterogeneous variances
Authors: Arrontes Julio
Published: October 2020

This report explores how the heterogeneity of variances affects randomization tests used to evaluate differences in the asymptotic population growth rate, λ. The probability of Type I error was calculated in four scenarios for populations with identical λ but different variance of λ: (1) Populations have different projection matrices: the same λ may be obtained from different sets of vital rates, which gives room for different variances of λ. (2) Populations have identical projection matrices but reproductive schemes differ and fecundity in one of the populations has a larger associated variance. The two other scenarios evaluate a sampling artifact as responsible for heterogeneity of variances. The same population is sampled twice, (3) with the same sampling design, or (4) with different sampling effort for different stages. Randomization tests were done with increasing differences in sample size between the two populations. This implies additional differences in the variance of λ. The probability of Type I error keeps at the nominal significance level (α = .05) in Scenario 3 and with identical sample sizes in the others. Tests were too liberal, or conservative, under a combination of variance heterogeneity and different sample sizes. Increased differences in sample size exacerbated the difference between observed Type I error and the nominal significance level. Type I error increases or decreases depending on which population has a larger sample size, the population with the smallest or the largest variance. However, by their own, sample size is not responsible for changes in Type I errors.
Looking back at multidrug resistance (MDR) research and ten mistakes to be avoided when writing about ABC transporters in MDR
Authors: Borst Piet
Published: October 2020

This paper presents a personal, selective, and sometimes critical retrospective of the history of ABC transporters in multidrug resistance (MDR) of cancer cells, overrepresenting discoveries of some early pioneers, long forgotten, and highlights of research in Amsterdam, mainly focussing on discoveries made with disruptions of ABC genes in mice (KO mice) and on the role of ABC transporters in causing drug resistance in a mouse model of mammary cancer. The history is complemented by a list of erroneous concepts often found in papers and grant applications submitted anno 2020.
Cardiolipin deficiency in Barth syndrome is not associated with increased superoxide/H2O2 production in heart and skeletal muscle mitochondria
Authors: Goncalves Renata L. S. , Schlame Michael , Bartelt Alexander , Brand Martin D. , Hotamışlıgil Gökhan S.
Published: October 2020

Barth syndrome (BTHS) is a rare X‐linked genetic disorder caused by mutations in the gene encoding the transacylase tafazzin and characterized by loss of cardiolipin and severe cardiomyopathy. Mitochondrial oxidants have been implicated in the cardiomyopathy in BTHS. Eleven mitochondrial sites produce superoxide/hydrogen peroxide (H2O2) at significant rates. Which of these sites generate oxidants at excessive rates in BTHS is unknown. Here, we measured the maximum capacity of superoxide/H2O2 production from each site and the ex vivo rate of superoxide/H2O2 production in the heart and skeletal muscle mitochondria of the tafazzin knockdown mice (tazkd) from 3 to 12 months of age. Despite reduced oxidative capacity, superoxide/H2O2 production was indistinguishable between tazkd mice and wild‐type littermates. These observations raise questions about the involvement of mitochondrial oxidants in BTHS pathology.
Ultrahighly Efficient White Quantum Dot Light‐Emitting Diodes Operating at Low Voltage
Authors: Zhu Yangbin , Xu Rui , Zhou Yuangui , Xu Zhongwei , Liu Yang , Tian Fengqing , Zheng Xiaojing , Ma Fumin , Alsharafi Rashed , Hu Hailong , Guo Tailiang , Kim Tae Whan , Li Fushan
Published: October 2020

Achieving efficient white quantum dot light‐emitting diodes (WQLEDs) is highly desired because of their promising applications in general illumination and display backlight systems. Herein, a highly efficient WQLED with an extremely low input voltage is reported, which is fabricated via an all‐solution process by using an emitting layer with a mixture of red‐, blue‐, and green‐emitting quantum dots. When a facile strategy of light outcoupling with an optical lens is introduced, the device shows a maximum external quantum efficiency of 28.4%, which is the highest value reported so far. Moreover, the device exhibits a standard white emission with International Commission on Illumination (CIE) coordinates of (0.36, 0.34) at an extremely low input voltage of 3.2 V. This work provides a promising way for achieving high‐performance white quantum‐dot light‐emitting diodes with low driving voltage.
Ag‐Catalyzed Cyclization of Arylboronic Acids with Elemental Selenium for the Synthesis of Selenaheterocycles
Authors: Zhang Xue , Huang Xiao‐Bo , Gao Wen‐Xia , Zhou Yun‐Bing , Liu Miao‐Chang , Wu Hua‐Yue
Published: October 2020

A general method for the synthesis of five‐membered and six‐membered selenaheterocycles through Ag‐catalyzed C−Se bond‐forming reaction is reported. This reaction proceeds via intramolecular cyclization of arylboronic acids with selenium powder. Preliminary mechanism studies demonstrate that this transformation involves a selenium‐centred radical intermediate.

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Adenoviral Mediated Delivery of OSKM Factors Induces Partial Reprogramming of Mouse Cardiac Cells In Vivo
Authors: Kisby Thomas , de Lázaro Irene , Fisch Sudeshna , Cartwright Elizabeth J. , Cossu Giulio , Kostarelos Kostas
Published: October 2020

The induction of in vivo reprogramming toward pluripotency has been demonstrated in several tissues utilizing either transgenic inducible mice or gene delivery approaches. However, the effects of exogenous reprogramming factor expression in the mammalian heart have not been previously reported. The present study aims to investigate the response of cardiac cells to ectopic Oct3/4, Sox2, Klf4, and cMyc (OSKM) expression in vivo using a non‐integrating adenoviral vector. Direct intramyocardial injection of this vector achieves effective and transient OSKM overexpression in the healthy heart and after myocardial infarction. The expression of these factors induces transient upregulation of a number of endogenous pluripotency (endo‐Oct3/4, Gdf3) and reprogramming related (Cdh1, Fut4) genes, confirming the induction of cell reprogramming. Despite the initiation of reprogramming, markers of fully de‐differentiated cells including Nanog remain silenced, consistent with a partially reprogrammed state. Furthermore, no indications of tumorigenesis or teratoma formation are observed. Overall, these data suggest that adenoviral mediated OSKM delivery can be utilized to induce partial in vivo reprogramming. However, the absence of any clear regenerative effects after myocardial infarction indicates that further optimization of vector mediated reprogramming strategies is essential to overcome barriers to therapeutic efficacy.
Energy intake and expenditure in children and adolescents, contributions of biological maturity
Authors: Silva Ana L. , Teles Júlia , Olivares Luís F. , Fragoso Isabel
Published: October 2020

Objective

The aim of this study was to examine the relationship between the ratio of energy intake (EI) and energy expenditure (EE) and body composition, physical activity and macronutrients intake, considering maturity as a moderator.

Methods

The study involved 459 adolescents aged 10 to 17. Energy and macronutrients intake were estimated using a valid Food Frequency Questionnaire; basal metabolic rate (BMR) was predicted from Schofield equations and EE was estimated using BMR and physical activity level obtained through a Portuguese validated biosocial questionnaire.

Body mass index, body composition, and bone age were objectively measured. Statistical analyses included independent samples t‐tests, ANCOVA and Pearson correlations. All analyses were adjusted for chronological age, sex, and EI.

Results

Body mass index, fat and fat‐free mass, physical activity and protein intake were negatively correlated with EI/EE (P < .001). The study showed significant interactions between maturity and body mass index, fat‐free mass and physical activity level. Maturity attenuated the negative relationships between EI/EE and body mass index, fat‐free mass and physical activity, especially among early maturers. All categories of maturity showed implications in body mass index for values lower than 23.8 kg/m2. A significant EI/EE reduction was observed among late maturers with a fat‐free mass above 39.8 kg.

Conclusions

Our findings suggest that maturity moderates the relationship between EI/EE and body mass index, fat‐free mass and physical activity, especially evident among late maturers.
Indigenous Data Sovereignty in the Era of Big Data and Open Data
Authors: Walter Maggie , Lovett Raymond , Maher Bobby , Williamson Bhiamie , Prehn Jacob , Bodkin‐Andrews Gawaian , Lee Vanessa
Published: October 2020

Indigenous Data Sovereignty, in its proclamation of the right of Indigenous peoples to govern the collection, ownership, and application of data, recognises data as a cultural and economic asset. The impact of data is magnified by the emergence of Big Data and the associated impetus to open publicly held data (Open Data). Aboriginal and Torres Strait Islander peoples, families and communities, heavily overrepresented in social disadvantage–related data will also be overrepresented in the application of these new technologies, but in a data landscape, Indigenous peoples remain largely alienated from the use of data and its utilization within the channels of policy power. Existing data infrastructure, and the emerging Open Data infrastructure, neither recognise Indigenous agency and worldviews nor consider Indigenous data needs. This is demonstrated in the absence of any consideration of Indigenous data issues in Open Data discussions and publication. Thus, while the potential benefits of this data revolution are trumpeted, our marginalised social, cultural and political location suggests we will not share equally in these benefits. This paper discusses the unforeseen (and likely unseen) consequences of the influence of Open Data and Big Data and discusses how Indigenous Data Sovereignty can mediate risks while providing pathways to collective benefits.
Efficient Conversion of Glycerol into High Value‐Added Chemicals by Partial Oxidation
Authors: Chida Tsutomu , Hiromori Kousuke , Shibasaki‐Kitakawa Naomi , Mimura Naoki , Yamaguchi Aritomo , Takahashi Atsushi
Published: October 2020

Glycerol can be effectively converted to glyceric acid, a high value‐added pharmaceutical raw material, through its partial oxidation over an Au/Al2O3 catalyst under strongly basic conditions. The factors important for the highly selective production of glyceric acid were investigated experimentally. It was clarified that NaOH was involved in the glycerol activation step to a glycerol alkoxide intermediate (2, 3‐dihydroxypropoxide) in the liquid phase, then glyceric acid was formed by OOH species derived from O2 on an Au catalyst in the partial oxidation step. We have newly discovered the concerted effect of NaOH and O2 in different reaction steps.
Guidelines in Practice: Sharps Safety
Authors: Link Terri
Published: October 2020

Perioperative personnel are at risk for sharps injuries when using devices with sharp points and edges and therefore are at risk for infection from exposure to blood and other potentially infectious body fluids. The Occupational Safety and Health Administration bloodborne pathogens standard is the regulatory document that health care employers must follow to protect personnel who are at risk for sharps injuries. The AORN “Guideline for sharps safety” provides guidance to perioperative personnel for identifying sharps hazards and implementing best practices to prevent injuries. This article discusses the guideline recommendations for developing and implementing work practice controls and administrative controls for handling sharps. A scenario describes an interdisciplinary team's efforts to decrease specific sharps injuries and develop policies and procedures based on the identified risks and practice changes. Perioperative RNs should review the entire guideline for additional information when creating and updating policies and procedures for sharps safety.
Synthesis of a green reactive flame‐retardant polyether polyol and its application
Authors: Li Xue , Yu Zaiqian , Zhang Long
Published: October 2020

The low‐flame retardancy properties of pure rigid polyurethane (PU) foams hindered its practical application in many cases for the safety and environmental concern. Although rigid PU foams with flame retardants can achieve standard of fire resistance, addition of flame retardants in PU can worsen its mechanical properties, enlarge production cost, and induce safety problems. Therefore, green reactive flame‐retardant polyether polyols (GPP) have been considered as one of the best solutions. In this work, the GPP by the ring‐opening polymerization of the self‐made environmentally friendly melamine resin (EFMR) with propylene oxide are synthesized with their hydroxyl number of 390 ~ 420 mg KOH/g, and the structure of GPP product was identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The flame‐retardant rigid polyurethane foams (RPUFs) were successfully prepared with GPP as the polyol, the results showed that the addition of GPP can greatly improve the thermal stability and flame retardancy of the RPUFs prepared. The RPUF were prepared by fully GPP with 30.4% of limiting oxygen index and 350 kpa of compressive strength. These properties are qualified for commercial utilization. Therefore, this GPP provides great prospect in the development of specified flame‐retardant PU materials.
Response surface optimization for improving the processing behavior of melamine formaldehyde impregnation resins
Authors: Seidl Regina , Weiss Stephanie , Zikulnig‐Rusch Edith M. , Kandelbauer Andreas
Published: October 2020

Melamine‐formaldehyde resins are widely used for decorative paper impregnation. Resin properties relevant for impregnation are mainly determined already at the stage of resin synthesis by the applied reaction conditions. Thus, understanding the relationship between reaction conditions and technological properties is important. Response surface methodology based on orthogonal parameter level variations is the most suitable tool to identify and quantify factor effects and deduce causal correlation patterns. Here, two major process factors of MF resin synthesis were systematically varied using such a statistical experimental design. To arrive at resins having a broad range of technological properties, initial pH and M:F ratio were varied in a wide range (pH: 7.9–12.1; M:F ratio: 1:1.5–1:4.5). The impregnation behavior of the resins was modeled using viscosity, penetration rate and residual curing capacity as technological responses. Based on the response surface models, nonlinear and synergistic action of process factors was quantified and a suitable process window for preparing resins with favorable impregnation performance was defined. It was found that low M:F ratios (~1:2–1:2.5) and comparatively high starting pHs (~pH 11) yield impregnation resins with rapid impregnation behavior and good residual curing capacity.
Biomimetic soy protein‐based exterior‐use films with excellent UV‐blocking performance from catechol derivative Acacia mangium tannin
Authors: Wang Liuliu , Liu Jian , Zhang Wei , Zhang Derong , Li Jianzhang , Zhang Shifeng
Published: October 2020

Polymer plastic is the main component of current outdoor packaging film materials that are mostly derived from fossil fuels. Its poor ultraviolet (UV) barrier performance and short service life caused by aging degradation result in increased non‐renewable consumption and environmental pollution. The most effective way to solve these problems is the development of a biomass‐based and eco‐friendly packaging with excellent UV‐blocking performance. Herein, inspired by mussels, a facile strategy is reported for the preparation of a biomimetic polymeric material via the incorporation of a biomass‐derived catechol derivative Acacia mangium tannin (AMT) into a biodegradable soy protein isolate (SPI) matrix. The morphologies, mechanical, thermal properties, and UV‐blocking abilities and mechanisms of the modified films were evaluated. With the increase of the AMT content, the stress of the composite film was found to gradually increase, and the modified SPI composite film exhibited a powerful tensile strength of 7.64 MPa and a high breaking strain of 145.6%. After the introduction of AMT, the films exhibited excellent UV‐blocking performance. As both SPI and AMT are biodegradable, this work presents an innovative design strategy for fully‐biodegradable and robust polymeric materials with excellent UV‐blocking performance that have promising potential applications in packaging.
The role of thermodynamic efficiency in setting the star formation efficiency of self‐gravitating molecular clouds
Authors: Kumssa Gemechu M. , Tessema S. B.
Published: October 2020

We study the star formation efficiency per free‐fall time(ϵff) of a self‐gravitating molecular cloud (MC) in the presence of dimensionless thermodynamic efficiency factor ϵ, quantified by taking the ratio of radiation luminosity to the gravitational energy released per free‐fall time (i.e., ) where 0 < ϵ < 1. The results of previous studies indicated that theoretically calculated star formation efficiency of the self‐gravitating MC is larger than the results obtained by observation. These differences may occur due to systematic errors in addition to other physical factors. Currently, there is no single complete model describing star formation efficiency because stars form in a complex and dynamically varying environment. Based on this conceptual framework, we model the equation of star formation efficiency in free‐fall time (ϵff). Moreover, we formulated stellar mass in terms of star formation efficiency by combining the critical mass and the stellar mass models taken from literature. The results indicate that the thermodynamic efficiency factor together with fundamental parameters of the cloud and the time scales play a crucial role in describing the star formation efficiency (SFE) of self‐gravitating MC in its free‐fall time.