bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the carbohydrate recognition domain of human E‐selectin
Authors: Mills Alan
Published: July 2002

The three‐dimensional structure of the carbohydrate recognition domain of the human E‐selectin endothelial‐leucocyte adhesion molecule (ELAM‐1) was modelled on the basis of the recently determined X‐ray crystallographic structure of the homologous domain found in the rat mannose‐binding protein. The EGF‐like module, which is contiguous to the E‐selectin lectin domain, and which is also involved in binding the tetrasaccharide ligand, was modelled on the recently determined NMR structure of the EGF‐like module of human factor IX. The rule‐based homology modelling procedures developed at Birkbeck and encoded in the program COMPOSER were used. The model of the two domains combined is discussed in terms of cation and ligand binding.
Fluorescence quenching at interfaces and the permeation of acrylamide and iodide across phospholipid bilayers
Authors: Moro Fernando , Goñi Félix M. , Urbaneja M.Angeles
Published: July 2002

Studies of fluorescence quenching in membrane proteins are complicated by the fact that the barrier effect of the bilayer towards the quenchers is not known with precision. Our studies show that (a) both acrylamide and iodide can permeate the membrane at comparable rates, (b) when quenchers are added externally to a vesicle suspension, the apparent Stern‐Volmer quenching constants for the same fluorophores are lower in the inner than in the outer aqueous compartments, and (c) at least some non‐polar fluorophores embedded in the bilayer are quenched by iodide, but not by acrylamide.
P80 form of the human tumor necrosis factor receptor is involved in DNA fragmentation
Authors: Higuchi Masahiro , Aggarwal Bharat B.
Published: July 2002

Two different types of TNF receptors with molecular masses of 60 kDa (p60) and 80 kDa (p80) have been identified. TNF is known to cause DNA fragmentation in certain tumor cell lines but the role of p60 and p80 in this action is not understood. In the present study, we examined the role of these receptors in TNF‐induced DNA fragmentation. Treatment of U‐937 cells with phorbol ester caused downregulation of both types of TNF receptors and this was accompanied by disappearance of the TNF‐induced DNA fragmentation. The removal of phorbol ester led to two time‐dependent events: (1) the rapid regeneration of the p80 form but not the p60 form of the TNF receptor; and (2) the reappearance of TNF‐induced DNA fragmentation. These results suggest that the p80 receptor could mediate the TNF‐induced DNA fragmentation.
Hydrolysis of small peptide substrates parallels binding of chymotrypsin inhibitor 2 for mutants of subtilisin BPN'
Authors: Eder Jörg , Rheinnecker Michael , Fersht Alan R.
Published: July 2002

Variants of subtilisin BPN' that possess improved specificity towards isoleucine compared with alanine at the P4 position of small peptide substrates, were analysed for their ability to bind chymotrypsin inhibitor 2. The binding of the inhibitor with isoleucine (wild‐type) and with alanine as the P4 residue parallels the hydrolysis of tetrapeptide substrates. There is a linear relationship between the free energy of binding of the transition state of the substrate and the free energy of binding of the inhibitor with a slope of 2.0. The data suggest that the inhibitor uses predominantly ground state rather than transition state binding energy.
A1F‐B, a novel CCAAT‐binding transcription activator that interacts with the aldolase B promoter
Authors: Tsutsumi Ken-ichi , Ito Kikukatsu , Yabuki Tomoko , Ishikawa Kiichi
Published: July 2002

We describe here a 70 kDa transcription factor A1F‐B, which preferentially binds to an element encompassing a CCAAT motif on the rat aldolase B promoter. Comparison of binding specificities, relative molecular masses, and subunit compositions with those of other known CCAAT‐binding factors indicated that A1F‐B is a novel member of CCAAT‐binding factors.
Interaction of clavulanate with class C β‐lactamases
Authors: Monnaie Didier , Frere Jean-Marie
Published: July 2002

The interactions between clavulanate and three class C enzymes have been studied in detail. In all cases, the reactions followed branched pathways where 25–150 turnovers occurred before inactivation was completed. Reactivation rates were quite low. The poor efficiency of clavulanate as a class C inactivator appeared to rest upon a very slow acylation of the protein, and of a relatively high turnover rate.
Purification of hydroxylamine oxidase from Thiosphaera pantotropha
Authors: Wehrfritz Josa-Marie , Reilly Ann , Spiro Stephen , Richardson David J.
Published: July 2002

Thiosphaera pantotropha, a Gram‐negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic hydroxylamine oxidase that differs markedly from the hydroxylamine oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C
551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant.
A conserved intron in the V‐ATPase A subunit genes of plants and algae
Authors: Starke Thomas , Gogarten Johann Peter
Published: July 2002

Amplification and sequencing of part of the coding regions of the catalytic V‐type ATPase subunit shows the presence of (at least) two genes in all land plants as well as the conservative insertion of a noncoding sequence. The two genes exhibit a coding region of the same length but differ in the number of nucleotides present in the intron. The latter is surprisingly conserved suggesting the presence of functional constraints on the intron sequences. The findings presented in this report indicate that introns from plants and animals are characterized by different internal structural elements.
Expression of a novel human homeobox‐containing gene that maps to chromosome 7q36.1 in hematopoietic cells
Authors: Matsui Toshikazu , Hirai Momoki , Wakita Machiko , Hirano Masami , Kurosawa Yoshikazu
Published: July 2002

A homeobox is a DNA sequence of 180 base pairs that encodes a DNA‐binding domain known as a homeodomain. The polymerase chain reaction (PCR) has been used to prepare probes of homeobox‐containing genes. We cloned and sequenced the amplified products of PCR that was performed with human genomic DNA and two primers that correspond to well‐conserved regions in homeoboxes. Fifteen kinds of homeobox gene were identified and 13 of them were assigned to HOX genes that have already been reported. Two others represented novel homeobox genes and one of them, GBX1, was mapped to chromosome 7q36.1 by fluorescence in situ hybridization. Northern hybridization of mRNA for various kinds of hematopoietic cell showed that the newly identified GBX1 gene is expressed in K562 cells and Daudi cells.
Sequence similarities in (α/β)8‐barrel enzymes revealed by conserved regions of α‐amylase
Authors: Janeček Štefan
Published: July 2002

The parallel (α/β)8‐barrel is a frequently occurring protein‐folding motif. Although the arrangement of secondary structural elements along the barrel is very similar in different (α/β)8‐barrel enzymes, there is a very low mutual amino acid sequence homology among the enzymes, contributing in part to the hazy view of their evolution. Here an approach to identifying at least the rough of evolutionarily conserved (α/β)8‐barrel sequence is presented. Based on the idea that highly conserved sequence regions of a particular enzyme should be more or less conserved in the sequences of the other evolutionary related enzymes, five sequence similarities of ten different (α/β)8‐barrel enzymes were revealed, using the five conserved regions of the amino acid sequence of the α‐amylase (α/β)8‐barrel as the templates.
SR141716A, a potent and selective antagonist of the brain cannabinoid receptor
Authors: Rinaldi-Carmona Murielle , Barth Francis , Héaulme Michel , Shire David , Calandra Bernard , Congy Christian , Martinez Serge , Maruani Jeanne , Néliat Gervais , Caput Daniel , Ferrara Pascual , Soubrié Philippe , Brelière Jean Claude , Le Fur Gérard
Published: July 2002

SR141716A is the first selective and orally active antagonist of the brain cannabinoid receptor. This compound displays nanomolar affinity for the central cannabinoid receptor but is not active on the peripheral cannabinoid receptor. In vitro, SR141716A antagonises the inhibitory effects of cannabinoid receptor agonists on both mouse vas deferens contractions and adenylyl cyclase activity in rat brain membranes. After intraperitoneal or oral administration SR141716A antagonises classical pharmacological and behavioural effects of cannabinoid receptor agonists. This compound should prove to be a powerful tool for investigating the in vivo functions of the anandamide/cannabinoid system.
Families of zinc metalloproteases
Authors: Hooper Nigel M.
Published: July 2002

A scheme based on the zinc binding site [1992, FEBS Lett. 312, 110–114] has been extended to classify zinc metalloproteases into distinct families. The gluzincins, defined by the HEXXH motif and a glutamic acid as the third zinc ligand, include the thermolysin, endopeptidase‐24.11, aminopeptidase, angiotensin converting enzyme, endopeptidase‐24.15, and tetanus and botulinum neurotoxin families. The metzincins, defined by the HEXXH motif, a histidine as the third zinc ligand and a Met‐turn, include the astacin, serralysin, reprolysin and matrixin families. The inverted zincin motif, HXXEH, defines the inverzincin family of insulin‐degrading enzymes, the HXXE motif defines the carboxypeptidase family, and the HXH Motif dd‐carboxypeptidase.
Receptor availability defines the extent of agonist‐mediated G‐protein down‐regulation in neuroblastoma × glioma hybrid cells transfected to express the β2‐adrenoceptor
Authors: Kim Gun-Do , Milligan Graeme
Published: July 2002

Sustained exposure of neuroblastoma × glioma hybrid, NG108‐15, cells transfected to express the human, β2‐adrenoceptor (clone βN22) to isoprenaline or iloprost (an agonist at the endogenously expressed IP prostanoid receptor) resulted in a substantial and selective down‐regulation of the α subunit of the G‐protein Gs. Treatment of these cells with the irreversible β‐adrenoceptor antagonist bromoacetyl alprenolol menthane diminished both the potency and the maximal ability of isoprenaline but not of iloprost to cause Gsα down‐regulation. These results demonstrate that the extent of agonist‐mediated Gsα down‐regulation is dependent upon the availability of receptor to agonist.
Guanosine 5'‐(γ‐thio) triphosphate (GTPγS) inhibits phosphorylation of insulin receptor and a novel GTP‐binding protein, Gir, from human placenta
Authors: Srivastava Satish K. , Varma Tushar K. , Sinha Ashish C. , Singh Ugra S.
Published: July 2002

A novel 66 kDa GTP‐binding protein, designated Gir, has been partially purified along with insulin receptor (IR) from human placenta. This protein binds 8‐azido‐GTP, is ADP‐ribosylated by pertussis toxin, phosphorylated by IR tyrosine kinase and cross‐reacts with antibodies against synthetic peptides from the GTP‐binding domain of Gzα (P960). Phosphorylation of IR‐β subunit and Gir by IR tyrosine kinase was almost completely inhibited by 100 μM GTPγS, >75% by 50 μM and 20–30% by 1 μM, while GDP at these concentrations had no significant effect on the phosphorylation. IR tyrosine kinase phosphorylated Gir at the tyrosine residues. These studies indicate regulation of IR tyrosine kinase activity by guanosine phosphates and involvement of Gir in insulin action.
Diagnostic relevance of sleep complaints in anxiety and mood disorders
Authors: Arriaga F , Lara E , Matos-Pires A , Cavaglia F , Bastos L
Published: July 2002

Clinical assessments of sleep and subjective state upon waking were performed in normal controls and patients with generalised anxiety disorder, panic disorder, obsessive-compulsive disorder, primary dysthymia and major depression. Subjects were selected according to DSM-III-R criteria. As compared to normal controls, patients with generalised anxiety, dysthymia and major depression exhibit pervasive and intense complaints of insomnia, and no clear distinctions can be drawn among these groups. Patients with panic disorder do not differ from normal controls, whereas obsessive compulsive patients present limited sleep symptoms. These findings suggest that subjective sleep variables are relevant for the diagnostic discrimination of panic and obsessive-compulsive disorders.
Quality of life measurements in major depression
Authors: Bech P
Published: July 2002

In randomized clinical trials in patients with major depression quality of life is considered as an important dimension of treatment outcome in relation to clinical efficacy and safety. The internal validity, reliability, as well as external validity of quality of life scales have been analysed. It is concluded that such scales have their most appropriate applicability in medicine and long-term trials with antidepressants.
Requirements of basic amino acid residues within the lectin‐like domain of LOX‐1 for the binding of oxidized low‐density lipoprotein
Authors: Chen Mingyi , Inoue Kazuhiko , Narumiya Shuh , Masaki Tomoh , Sawamura Tatsuya
Published: July 2002

Lectin‐like OxLDL receptor‐1 (LOX‐1) was identified as the major receptor for oxidized low‐density lipoprotein (OxLDL) in aortic endothelial cells. LOX‐1 is a type II membrane protein that structurally belongs to the C‐type lectin family. Here, we found that the lectin‐like domain of LOX‐1 is essential for ligand binding, but the neck domain is not. In particular, the large loop between the third and fourth cysteine of the lectin‐like domain plays a critical role for OxLDL binding as well as C‐terminal end residues. Alanine‐directed mutagenesis of the basic amino acid residues around this region revealed that all of the basic residues are involved in OxLDL binding. Simultaneous mutations of these basic residues almost abolished the OxLDL‐binding activity of LOX‐1. Electrostatic interaction between basic residues in the lectin‐like domain of LOX‐1 and negatively charged OxLDL is critical for the binding activity of LOX‐1.
Resistance to fluconazole and cross‐resistance to amphotericin B in Candida albicans from AIDS patients caused by defective sterol Δ5,6‐desaturation
Authors: Kelly S.L , Lamb D.C , Kelly D.E , Manning N.J , Loeffler J , Hebart H , Schumacher U , Einsele H
Published: July 2002

Fluconazole resistance occurs in >10% of cases of candidosis during the late stages of AIDS. We show here in two clinical isolates that resistance was caused by defective sterol Δ5,6‐desaturation. This altered the type of sterol accumulating under fluconazole treatment from 14α‐methylergosta‐8,24(28)‐dien‐3β,6α‐diol to 14α‐methylfecosterol which is capable of supporting growth. A consequence of this mechanism of azole resistance is that an absence of ergosterol causes cross‐resistance to the other major antifungal agent available, amphotericin B. The results also show that growth arrest after fluconazole treatment of C. albicans in clinical conditions is caused by 14α‐methylergosta‐8,24(28)‐dien‐3β,6α‐diol accumulation.
Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53
Authors: Honda Reiko , Tanaka Hirofumi , Yasuda Hideyo
Published: July 2002

The tumor suppressor p53 is degraded by the ubiquitin‐proteasome system. p53 was polyubiquitinated in the presence of E1, UbcH5 as E2 and MDM2 oncoprotein. A ubiquitin molecule bound MDM2 through sulfhydroxy bond which is characteristic of ubiquitin ligase (E3)‐ubiquitin binding. The cysteine residue in the carboxyl terminus of MDM2 was essential for the activity. These data suggest that the MDM2 protein, which is induced by p53, functions as a ubiquitin ligase, E3, in human papillomavirus‐uninfected cells which do not have E6 protein.
Role of P2Y1 purinoceptor in ADP‐induced platelet activation
Authors: Savi P , Beauverger P , Labouret C , Delfaud M , Salel V , Kaghad M , Herbert J.M
Published: July 2002

ADP acts as an agonist of platelet aggregation via specific receptors which are still to be characterised. Amplification by PCR of a human platelet cDNA library confirmed the presence of mRNA of the P2Y1 receptor in platelets. In order to determine if these P2Y1 receptors were involved in ADP‐induced platelet activation, we determined the effects of A3P5PS, an antagonist of the P2Y1 receptor, on the binding of [33P]2‐MeS‐ADP, a potent analogue of ADP. We found that A3P5PS displaced about 27% of [33P]2‐MeS‐ADP binding, a receptor population which has been shown to be resistant to treatment with clopidogrel, a selective anti‐ADP agent. A3P5PS specifically inhibited 2‐MeS‐ADP‐induced shape change and calcium increase but did not affect adenylyl cyclase down‐regulation. 2‐MeS‐ADP‐induced platelet aggregation was also inhibited by A3P5PS but was restored when platelets were further activated by serotonin, a non‐aggregating compound, therefore suggesting that P2Y1‐mediated stimulation is an absolute prerequisite for ADP to induce platelet aggregation and a key event for platelet activation and aggregation to occur. These results therefore show that ADP‐induced aggregation cannot be attributed to activation of P2Y1 alone, but must be attributed to the simultaneous activation of the high affinity receptor (P2Y1) and a low affinity receptor of ADP (still to be discovered), each of them essential, but neither able to trigger aggregation alone.
Xanthine oxidoreductase catalyses the reduction of nitrates and nitrite to nitric oxide under hypoxic conditions
Authors: Millar Timothy M , Stevens Cliff R , Benjamin Nigel , Eisenthal Robert , Harrison Roger , Blake David R
Published: July 2002

Xanthine oxidoreductase (XOR) catalyses the reduction of the therapeutic organic nitrate, nitroglycerin (glyceryl trinitrate, GTN), as well as inorganic nitrate and nitrite, to nitric oxide (NO) under hypoxic conditions in the presence of NADH. Generation of nitric oxide is not detectable under normoxic conditions and is inhibited by the molybdenum site‐specific inhibitors, oxypurinol and (−)BOF 4272. These enzymic reactions provide a mechanism for generation of NO under hypoxic conditions where nitric oxide synthase does not function, suggesting a vasodilatory role in ischaemia.
Carotenoid mixtures protect multilamellar liposomes against oxidative damage: synergistic effects of lycopene and lutein
Authors: Stahl Wilhelm , Junghans Angelika , de Boer Ben , Driomina Elena S , Briviba Karlis , Sies Helmut
Published: July 2002

Antioxidant activity of carotenoids in multilamellar liposomes assayed by inhibition of formation of thiobarbituric acid‐reactive substances was in the ranking: lycopene>α‐tocopherol>α‐carotene>β‐cryptoxanthin>zeaxanthin=β‐carotene>lutein. Mixtures of carotenoids were more effective than the single compounds. This synergistic effect was most pronounced when lycopene or lutein was present. The superior protection of mixtures may be related to specific positioning of different carotenoids in membranes.
Expression of matrix Gla protein (MGP) in an in vitro model of vascular calcification
Authors: Mori Katsuhito , Shioi Atsushi , Jono Shuichi , Nishizawa Yoshiki , Morii Hirotoshi
Published: July 2002

To investigate the role of matrix Gla protein (MGP), which can bind mineral ions through γ‐carboxylated glutamic acid residues, in vascular calcification, we examined the expression of MGP in an in vitro calcification model by using bovine vascular smooth muscle cells (BVSMC). The expression of MGP mRNA was decreased during BVSMC calcification and its levels were inversely correlated with the quantities of BVSMC calcification. MGP mRNA expression was restored to the level of uncalcified control by inhibiting BVSMC calcification with bisphosphonates. These data suggest that the expression of MGP gene is modulated in the development of vascular calcification.
P2Y receptor subtypes differentially couple to inwardly‐rectifying potassium channels
Authors: Mosbacher J , Maier R , Fakler B , Glatz A , Crespo J , Bilbe G
Published: July 2002

Subtypes of P2Y receptors are well characterized with respect to their agonist profile but little is known about differences in their intracellular signalling properties. When expressed in Xenopus oocytes, both P2Y2 and P2Y6 receptors effectively couple to endogenous Ca2+‐dependent Cl−‐channels. However, only P2Y2 receptors increased currents mediated by inward‐rectifier K+ channels of the Kir3.0 subfamily. This incrase in Kir‐current was sensitive to pertussis toxin, while activation of Ca2+‐dependent Cl−‐channels was not. In contrast, suramin, a P2 receptor antagonist, inhibited activation of both channels. These observations suggest that, in contrast to P2Y6, P2Y2 receptors couple to two different classes of G proteins.
Detoxication of carcinogenic fjord‐region diol epoxides of polycyclic aromatic hydrocarbons by glutathione transferase P1‐1 variants and glutathione
Authors: Sundberg Kathrin , Seidel Albrecht , Mannervik Bengt , Jernström Bengt
Published: July 2002

Epidemiological studies suggest that individuals differing in the expression of allelic variants of the human glutathione transferase (GST) Pi gene differ in susceptibility to chemical carcinogens such as polycyclic aromatic hydrocarbons (PAH). This study reports the catalytic efficiencies (k
cat/K
m) of two naturally occurring variants, GSTP1‐1/I‐105 and GSTP1‐1/V‐105, towards a series of fjord‐region diol epoxides representing potent biologically active PAH metabolites, and two GSTP1‐1 mutants with Ala105 and Trp105 in the active site. The results indicate that individuals who are homozygous for the allele encoding GSTP1‐1/V‐105 might be more susceptible to PAH carcinogenesis due to other reasons than a reduced capacity for detoxifying diol epoxides.
Positive feedback regulation of type I IFN genes by the IFN‐inducible transcription factor IRF‐7
Authors: Sato Mitsuharu , Hata Naoki , Asagiri Masataka , Nakaya Takeo , Taniguchi Tadatsugu , Tanaka Nobuyuki
Published: July 2002

The interferon regulatory factor (IRF) family of transcription factors regulate the interferon (IFN) system, among which IRF‐3 is involved in the virus‐induced IFN‐β gene expression. Here we show that another member IRF‐7 is critical for the IFN‐α gene induction. Unlike the IRF‐3 gene, the IRF‐7 gene is induced by IFNs through activation of the ISGF3 transcription factor, and IRF‐7 undergoes virus‐induced nuclear translocation. In cells lacking p48, an essential component of IFN stimulated gene factor 3 (ISGF3), ectopic expression of IRF‐7 but not IRF‐3 can rescue the deficiency to induce IFN‐α genes. These results indicate that IRF‐7 is a key factor in the positive feedback regulation of IFN‐α/β production.
Polymerization of tau peptides into fibrillar structures. The effect of FTDP‐17 mutations
Authors: Arrasate Monserrat , Pérez Mar , Armas-Portela Rosario , Ávila Jesús
Published: July 2002

The peptides corresponding to the four repeats found in the microtubule binding region of tau protein were synthesized and their ability for self‐aggregation in presence of heparin or chondroitin sulfate was measured. Mainly, only the peptide containing the third tau repeat is able to form polymers in a high proportion. Additionally, the peptide containing the second repeat aggregates with a very low efficiency. However, when this peptide contains the mutation (P301L), described in a fronto temporal dementia, it is able to form polymers at a higher extent. Finally, it is suggested to have a role for the first and fourth tau repeats. It could be to decrease the ability of the third tau repeat for self‐aggregation in the presence of heparin.
Characterization of the shrimp eyestalk cDNA encoding a novel fushi tarazu‐factor 1 (FTZ‐F1)1
Authors: Chan S.-M. , Chan K.-M.
Published: July 2002

To study the role of ecdysone and the ecdysone inducible gene in the regulation of molting and development in crustaceans, we have cloned a cDNA encoding an orphan nuclear receptor family member from the eyestalk of the shrimp Metapenaeus ensis. The size of the cDNA is 4.3 kb with the longest open reading frame (ORF) encoding a protein of 545 amino acid residues. The deduced amino acid sequence of the shrimp cDNA consists of regions that are characteristic of those of the nuclear hormone receptors. It shows a high degree of amino acid sequence identity in the DNA binding domain, ligand binding domain and the FTZ box as compared to those of invertebrates and vertebrates. Unlike the insects Drosophila melanogaster and Bombyx mori, an AF2 transactivation domain was present in the shrimp FTZ‐F1. Northern blot analysis using total RNA indicated that the FTZ‐F1 mRNA could also be detected in the mature ovary. Northern blot analysis and RT‐PCR analysis showed that the shrimp FTZ‐F1 transcripts could be detected in the ovary, newly hatched nauplius, testis, eyestalk and epidermis of the adult shrimp. Although the cDNA clone was isolated from the eyestalk library, the shrimp FTZ‐F1 appeared to express most abundantly in the mature oocytes. The presence of abundant FTZ‐F1 specific maternal message in the late vitellogenic ovary and early nauplius indicates that it may be important for the early embryonic and larval development of the shrimp. Interestingly, shrimp FTZ‐F1 can also be found in testis of the male shrimp. The presence of FTZ‐F1 in other tissues such as epidermis suggests that it may also be involved in other physiological processes such as molting.
Abnormal microtubule packing in processes of SF9 cells expressing the FTDP‐17 V337M tau mutation
Authors: Frappier Thierry , Liang Nina S. , Brown Kristy , Leung Conrad L. , Lynch Timothy , Liem Ronald K.H. , Shelanski Michael L.
Published: July 2002

Mutations in the gene for the microtubule associated protein, tau have been identified for fronto‐temporal dementia with Parkinsonism linked to chromosome 17 (FTDP‐17). In vitro data have shown that FTDP‐17 mutant tau proteins have a reduced ability to bind microtubules and to promote microtubule assembly. Using the baculovirus system we have examined the effect of the V337M mutation on the organization of the microtubules at the ultrastructural level. Our results show that the organization of the microtubules is disrupted in the presence of V337M tau with greater distances between the microtubules and fewer microtubules per process.
Effect of protein disulfide isomerase on the regeneration of bovine ribonuclease A with dithiothreitol
Authors: Shin Hang-Cheol , Scheraga Harold A
Published: July 2002

The role of protein disulfide isomerase (PDI) in the regeneration of ribonuclease A with dithiothreitol (DTT) was investigated at three different temperatures. The rates of formation of the native protein were markedly increased in the presence of PDI, 9‐fold at 15°C, 6‐fold at 25°C and 62‐fold at 37°C, respectively. In the presence of PDI, major changes were found in the distribution of intermediates in the three‐disulfide region at 25 and 15°C and also in the one‐disulfide region at 15°C, with the fast accumulation of the two native‐like species des‐[65‐72] and des‐[40‐95]. The present results indicate that PDI does not alter the two major parallel pathways involving des‐[65‐72] and des‐[40‐95] in the regeneration of ribonuclease A with DTT.
Amyloid fibril formation by pulmonary surfactant protein C
Authors: Gustafsson Magnus , Thyberg Johan , Näslund Jan , Eliasson Erik , Johansson Jan
Published: July 2002

Lung surfactant protein C (SP‐C) is a lipopeptide that contains two fatty acyl (palmitoyl) chains bound via intrinsically labile thioester bonds. SP‐C can transform from a monomeric α‐helix into β‐sheet aggregates, reminiscent of structural changes that are supposed to occur in amyloid fibril formation. SP‐C is here shown to form amyloid upon incubation in solution. Furthermore, one patient with pulmonary alveolar proteinosis (PAP, a rare disease where lung surfactant proteins and lipids accumulate in the airspaces) and six healthy controls have been studied regarding presence and composition of amyloid fibrils in the cell‐free fraction of bronchoalveolar lavage (BAL) fluid. Abundant amyloid fibrils were found in BAL fluid from the patient with PAP and, in low amounts, in three of the six healthy controls. SDS‐insoluble fibrillar material associated with PAP mainly consists of SP‐C, in contrast to the fibrils found in controls. Fibrillated SP‐C has to a significant extent lost the palmitoyl groups, and removal of the palmitoyl groups in vitro increases the rate of fibril formation.
Efficacy of ethanol sclerotherapy for ovarian endometriomas
Authors: Noma J , Yoshida N
Published: July 2002

Objective: To evaluate the efficacy and limitations of ethanol sclerotherapy for ovarian endometriomas. Methods: Retrospective investigation was made on 83 women with ovarian endometriomas who underwent transvaginal aspiration and ethanol sclerotherapy at Hiroshima City Hospital between 1993 and 1998. Furthermore, 30 who underwent laparoscopic cystectomy for ovarian endometriomas during the same period were investigated. Results: Of the 74 women who were followed for more than 6 months, 11 (14.9%) had recurrent cysts. The recurrence rate of laparoscopic cystectomy was 3.8% (NS). The recurrence rate of cases instilled for less than 10 min was 62.5% (5/8), and that for 10 or more than 10 min was 9.1% (6/66) (P<0.001). The recurrence rate of cases having one cyst was 7.5% (4/53) and that of cases having two or more cysts was 33.3% (7/21) (P<0.05). Conclusion: Ethanol sclerotherapy is an effective and safe procedure and can be indicated for almost all ovarian endometriomas. Conduct of ethanol instillation for more than 10 min particularly for a case with a single endometrial cyst is considered most effective from the standpoint of recurrence.
Interfacial Curvature as a Potential Index for Prognosis of Colon Adenocarcinoma
Authors: Gao Jingwei , Yang Chongqing , Li Jianjun , Liu Sidi , Ao Zhuo , Han Dong
Published: January 2021

Tumor invasion and metastasis are complex interfacial mechanical processes between the tumor and its surrounding tissue, with the interfacial curvature of tumor playing an important role in cancer progression. In this study, the potential role of interfacial curvature in the prognosis of patients with colon adenocarcinoma is investigated. The front edge interfacial curvature of adenocarcinoma from biopsies of patients in different tumor, lymph node, and metastasis (TNM) stages are calculated and compared, and prognosis assessment is conducted using Kaplan–Meier and Cox proportional hazards regression analyses. Results reveal that patients with larger interfacial curvature of adenocarcinoma are more likely to belong to higher TNM stages. Concomitantly, in the same TNM stage, patients with increased adenocarcinoma interfacial curvature show worse prognosis with higher recurrence and lower survival rates. Besides, interfacial curvature is an independent prognostic factor for cause‐specific survival and relapse‐free survival among all selected patients. Mechanical models of colon adenocarcinoma invasion and metastasis are established to better understand the close association between interfacial curvature and tumor progression. The results together with hematoxylin and eosin staining indicate that metastasis in stages T3N0M0 and T3N1M0 may be linked to large interfacial curvatures. Therefore, interfacial curvature may serve as a potential index for predicting prognosis in patients with colon adenocarcinoma.
A Covalently Integrated Reduced Graphene Oxide–Ion‐Exchange Resin Electrode for Efficient Capacitive Deionization
Authors: Islam Md Rabiul , Gupta Soujit Sen , Jana Sourav Kanti , Srikrishnarka Pillalamarri , Mondal Biswajit , Chennu Sudhakar , Ahuja Tripti , Chakraborty Amrita , Pradeep Thalappil
Published: January 2021

Capacitive deionization (CDI) is an emerging, cost‐effective alternative for energy‐efficient desalination technology. Efficient electrode materials based on individual reduced graphene oxide (rGO) nanosheets are produced by functionalizing them with polystyrene (rGO–PS) through an in situ polymerization process involving rGO, styrene monomer, and divinylbenzene. The rGO–PS‐integrated composite nanostructures are subsequently functionalized with sulfonate and quaternary amine functionalities to achieve positively and negatively charged electro‐adsorbent ion‐exchange resins (EAIERs), respectively. These EAIERs ‘molecular constructs’ are used to fabricate CDI electrodes, and deionization is performed to remove various ions. These molecular constructs promote faster charge transfer at the electrode–electrolyte interface and maintained the electrical conductivity of the active rGO. This leads to a high electroadsorption capacity of 15.93 mg g−1of Cl−using NaCl solution with a conductivity of 802 µS in laboratory batch experiments, which is approximately five times higher than the adsorption capacity of rGO electrodes reported earlier (≈2–3 mg g−1) in comparable experimental conditions. No significant Faradaic redox reactions or chemical changes are observed on the electrode surface, which make these electrodes exhibit excellent electrochemical stability even after multiple adsorption/desorption cycles.
J‐wave change during rewarming therapy for accidental hypothermia
Authors: Maeda Satoshi , Abe Ichitaro , Zaizen Hirofumi , Takahashi Naohiko
Published: January 2021

Background

J waves are abnormal electrocardiogram findings that indicate an elevation at the junction between the QRS complex and the ST segment. Hypothermia is associated with fetal arrhythmia, along with the increase of J‐wave manifestation.

Case Presentation

A 68‐year‐old woman with a medical history of old cerebral infarction and dementia was admitted to the emergency department with accidental hypothermia. An admission, electrocardiogram (ECG) showed prominent J waves with the highest amplitude recorded in limb and precordial leads. Continuous ECG monitoring was recorded during the rewarming therapy. As the body temperature increased, the amplitude of J waves became lower and disappeared. This case clearly showed that the degree of core body temperature is related to the height of the J‐wave amplitude. There was no fatal arrhythmia during rewarming therapy.

Conclusion

This case describes serial changes in the J‐wave amplitude and morphology during rewarming therapy. Continuous ECG monitoring is important in a patient with severe hypothermia.
Enhancement of Transmission Efficiency on Pancharatnam−Berry Geometric Phase Encoding Metasurfaces
Authors: Tang Xiaoyan , Li Chenxia , Gan Haiyong , He Yingwei , Jing Xufeng , Fang Bo , Hong Zhi
Published: January 2021

The modulation of the required light wavefront polarization and phase based on the geometric phase encoding metasurface (GPEM) has recently become a hot topic. However, the transmission coefficient of a geometric phase metasurface is greatly decreased when the structure is rotated. To address this problem, a solution of adding a tapered antireflection layer to the substrate and design an all‐dielectric encoding metasurface composed of titanium dioxide and silicon dioxide in the visible light band with a transmission coefficient of 93.65%, is proposed. When circularly polarized light is incident on the designed encoding metasurfaces with rotating unit structures, the GPEM still maintain almost perfect transmission coefficient as with initial linearly polarized light is incident. By comparing the coded metasurface with and without conical structure, the coded metasurface with conical structure can greatly improve transmission efficiency. Importantly, the Fourier convolution theorem in digital signal processing is introduced on encoding metasurfaces. The scattering angle of transmission can be controlled arbitrarily by the all‐dielectric coded metasurface with Fourier convolution addition and subtraction operations.
Ein offenschaliges Singulett‐SnI‐Diradikal und H2‐Spaltung
Authors: Sharma Mahendra K. , Rottschäfer Dennis , Glodde Timo , Neumann Beate , Stammler Hans‐Georg , Ghadwal Rajendra S.
Published: January 2021

Das erste SnI‐Diradikal [(ADCPh)Sn]2 (4) auf Basis eines anionischen Dicarbengerüsts (ADCPh={CN(Dipp)}2CPh; Dipp=2,6‐iPr2C6H3) wurde als grüner, kristalliner Feststoff durch KC8‐Reduktion des entsprechenden Bis‐Chlorstannylens [(ADCPh)SnCl]2 (3) isoliert. Der sechsgliedrige C4Sn2‐Ring von 4, der sechs π‐Elektronen enthält, zeigt einen diatropen Ringstrom, sodass 4 auch als das erste 1,4‐Distannabenzol‐Derivat bezeichnet werden kann. DFT‐Rechnungen deuten auf einen offenschaligen Singulett (OS)‐Grundzustand von 4 mit einer bemerkenswert kleinen Singulett‐Triplett‐Energielücke (ΔEOS–T=4.4 kcal mol−1) hin, was mit CASSCF‐Rechnungen (ΔES–T=6.6 kcal mol−1 und Diradikal‐Charakter y=37 %) übereinstimmt. Das Diradikal 4 spaltet bei Raumtemperatur H2 auf und liefert das Bis‐Hydridostannylen [(ADCPh)SnH]2 (5). Die weitere Reaktivität von 4 wurde mit PhSeSePh und MeOTf untersucht.
Practical and Selective sp3C−H Bond Chlorination via Aminium Radicals
Authors: McMillan Alastair J. , Sieńkowska Martyna , Di Lorenzo Piero , Gransbury Gemma K. , Chilton Nicholas F. , Salamone Michela , Ruffoni Alessandro , Bietti Massimo , Leonori Daniele
Published: January 2021

The introduction of chlorine atoms into organic molecules is fundamental to the manufacture of industrial chemicals, the elaboration of advanced synthetic intermediates and also the fine‐tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site‐selective chlorination of sp3C−H bonds. This process exploits the ability of protonatedN‐chloroamines to serve as aminium radical precursors and also radical chlorinating agents. Upon photochemical initiation, an efficient radical‐chain propagation is established allowing the functionalization of a broad range of substrates due to the large number of compatible functionalities. The ability to synergistically maximize both polar and steric effects in the H‐atom transfer transition state through appropriate selection of the aminium radical has provided the highest known selectivity in radical sp3C−H chlorination.
Platinum‐Catalyzed α,β‐Desaturation of Cyclic Ketones through Direct Metal–Enolate Formation
Authors: Chen Ming , Dong Guangbin
Published: January 2021

The development of a platinum‐catalyzed desaturation of cyclic ketones to their conjugated α,β‐unsaturated counterparts is reported in this full article. A unique diene‐platinum complex was identified to be an efficient catalyst, which enables direct metal‐enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including those sensitive to acids, bases/nucleophiles, or palladium species, are tolerated, which represents a distinct feature from other known desaturation methods. Mechanistically, this platinum catalysis exhibits a fast and reversible α‐deprotonation followed by a rate‐determining β‐hydrogen elimination process, which is different from the prior Pd‐catalyzed desaturation method. Promising preliminary enantioselective desaturation using a chiral‐diene‐platinum complex has also been obtained.
Minimization of Back‐Electron Transfer Enables the Elusive sp3 C−H Functionalization of Secondary Anilines
Authors: Zhao Huaibo , Leonori Daniele
Published: January 2021

Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N‐Dialkyl‐derivatives enable radical generation α to the N‐atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back‐electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α‐anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C−H functionalization.
Application of Kenaf Seed Oil‐Nanostructured Lipid Carrier to Palm‐Based α‐Tocopherol Cream for Photoprotection
Authors: Chu Chee Chin , Hasan Zafarizal Aldrin Bin Azizul , Tan Chin Ping , Nyam Kar Lin
Published: January 2021

The application of a nanostructured lipid carrier (NLC) to ultraviolet (UV) filter encapsulation was found to enhance its safe use. In this work, a kenaf seed oil‐NLC (KSO‐NLC) coloaded with 1% diethylamino hydroxybenzoyl hexyl benzoate and 1% ethylhexyl triazone was used as an active ingredient in α‐tocopherol cream to develop a photoprotective prototype. It was then subjected to further analysis to determine its physical properties, storage stability, and cytotoxicity. The ratio of KSO‐NLC to α‐tocopherol cream was optimized based on the sun protection factor (SPF) value using a UV transmittance analyzer. The physical properties of the samples were analyzed, and the amount of α‐tocopherol was quantified by ultra‐high‐performance liquid chromatography. The optimized sample was then evaluated for in vitro antioxidant activities using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid assays. Meanwhile, in vitro cytotoxicity was studied on a normal human dermal fibroblast cell line using thiazolyl blue tetrazolium bromide and cell counting kit‐8 assays. The sample of KSO‐NLC to α‐tocopherol cream in a ratio of 1:2 (N3) showed SPF value >50. Besides, the samples showed microbial stability and sustainable α‐tocopherol content upon 12 weeks of storage. The cytotoxicity evaluation of N3 and α‐tocopherol cream (N5) showed >100% cell proliferation, which indicated that there is no side effect on the cell growth, while triggering the cell proliferation with the presence of bioactive compounds. Overall, the findings of the study are promising for the development of new sunscreen formulation with the utilization of KSO‐NLC and palm‐based α‐tocopherol cream.
A cautionary tale about translocating mussels and implications for conservation: A case study from two river basins in central Texas
Authors: Hart Michael A. , Fisher Mark , Randklev Charles R.
Published: January 2021

Translocation is used to conserve mussels, yet there remains a debate about its merit owing to poor understating of its effects on transported mussels.

This study evaluated survivorship, body condition, and total glycogen and lipids for one common and widely distributed species (Cyclonaias pustulosa), two rare species (Cyclonaias petrina; Lampsilis bracteata), and one species complex (Fusconaia sp. – Fusconaia chunii and Fusconaia flava) from the East Fork of the Trinity River and the Llano River of Texas.

Survivorship estimates for C. pustulosa and Fusconaia sp. using the Kaplan–Meier estimator were high in the East Fork. Body condition, glycogen, and total lipids varied for C. pustulosa and Fusconaia sp., which may have indicated a short‐term impact. For the Llano, survivorship of C. petrina and L. bracteata was high for the resident treatments but significantly reduced for the translocation treatments.

The decline in survivorship for C. petrina was mirrored by decreases in the body condition, which may indicate inability to acclimate to novel environments. For L. bracteata, declines in survivorship were due to predation by Procyon lotor, racoon. A large flood of 3,766 m3 s−1 at the end of the study eliminated both study sites.

The findings of this study show that translocating mussels can be successful; however, sublethal effects and mortality may still occur. These effects are rooted in species‐specific differences, which is not unexpected because mussel species vary in how they cope with environmental change based on their life‐history traits. However, these traits are rarely considered when translocating mussels.

To complicate matters, most mussel species have yet to be evaluated on how they respond to translocation, and for species where such information is available, adults are the primary focus. Addressing these knowledge gaps is critical for determining the appropriateness of translocation and improving its efficacy.
My Private Lead Service Line
Authors: Jeznach Lillian C. , Goodwill Joseph E.
Published: January 2021

Key Takeaways

Homeowners’ decisions to replace their lead service lines (LSLs) can be complicated by factors including understanding of the science, perceptions of lead exposure risks, and cost of the work.

First‐draw and five‐minute flush samples may not capture the peak lead concentration, further complicating a customer's replacement decision.

In the author's case, sequential sampling indicated that LSL replacement for her home significantly lowered lead concentrations after stagnation.
Bohrverpresspfahl für Belastungen > 2 500 kN
Authors: Tapken Frank , Schwarz Andrej
Published: January 2021

Hafenanlagen gewinnen als Umschlagplatz für Güter jedweder Art immer mehr an Bedeutung. Material wird entladen und umgeschlagen und einer weiteren Verarbeitung zugeführt. Um den sicheren Betrieb insbesondere von größeren Schiffen mit deutlich höheren Tonnagen und immer leistungsstärkeren Kranen weiterhin sicherzustellen, werden die Hafenanlagen sukzessive technisch aufgerüstet. Unter anderem müssen viele Ufereinfassungen schrittweise den erhöhten Belastungen angepasst werden – so etwa in Form einer Ertüchtigung mittels Stahlspundwänden. Für deren sichere Rückverankerung kommen Pfahlsysteme zum Einsatz. Ein neues Mikropfahlsystem, welches sich durch hohe innere Tragfähigkeit und Tragreserven sowie große Robustheit und geringe Verformungen auszeichnet, ist der thyssenkrupp ASF Bohrverpresspfahl. Je nach Länge der Mikropfähle können Zugkräfte von bis zu 4 139 kN und Drucklasten bis 4 242 kN aufgenommen und in den Baugrund abgeleitet werden – unabhängig davon, ob ein bindiger oder nicht bindiger Boden vorliegt. Im Jahre 2019 hat das System, zu dessen weiteren Einsatzbereichen Gründungspfähle, Rückverankerung im Spezialtiefbau sowie Rückverankerung im Wasserstraßenausbau zählen, die DIBt‐Zulassung mit der Nummer Z‐34.14‐243 erhalten und ist damit bislang als einziges Mikropfahlsystem auf dem Markt nachweislich für Belastungen > 2 500 kN zugelassen.
Magnetoelastic sensors for real‐time tracking of cell growth
Authors: Shekhar Sudhanshu , Karipott Salil S. , Guldberg Robert E. , Ong Keat G.
Published: January 2021

Magnetoelastic (ME) sensors, which can be remotely activated via magnetic fields, are an excellent choice for wireless monitoring of biological parameters due to their ability to be scaled into different sizes and have their surface functionalized for chemical or biological sensing. In this study, we present the application of a commercially available ME material (Metglas 2826 MB) to develop a sensor system that can monitor the attachment of anchorage‐dependent mammalian cells in two‐dimensional in vitro cell cultures. Results obtained with the developed sensors and detection system correlated with microscopic image analysis of cell quantification, which showed a linear relationship between the sensor response and attached fibroblast cells on the sensor surface. It was also revealed that the developed ME sensor system is capable of providing temporal profiles of cell growth corresponding to different stages of cell attachment and proliferation in real‐time.