bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do Internet interventions for consumers cause more harm than good? A systematic review
Authors: Bessell Tracey L. , McDonald Steve , Silagy Chris A. , Anderson Jeremy N. , Hiller Janet E. , Sansom Lloyd N. 
Published: March 2003

Objective To systematically review the effect of consumer use of online health information on decision‐making, attitudes, knowledge, satisfaction and health outcomes and utilization. Search strategy Electronic databases searched included the Cochrane Controlled Trials Register, MEDLINE, PREMEDLINE (to 14 March 2001), CINAHL, Australian Medical Index, Health and Society, National Institutes of Health Clinical Trials Database and CenterWatch. Inclusion criteria All post‐1995 comparative studies (including controlled studies, before and after studies, and interrupted time series analyses) of Internet users vs. non‐Internet users and other communications mediums, and Internet characteristics such as e‐mail vs. other communication mediums, were included. Outcomes included consumer decision‐making, attitudes, knowledge, satisfaction and measurable changes in health status or health utilization. Data extraction and synthesis One reviewer screened all papers then two reviewers independently assessed studies against the selection criteria and any discrepancies were resolved by discussion with a third reviewer. No attempt was made to combine the data for further statistical analysis. Main results We identified 10 comparative studies. Studies evaluated the effectiveness of using the Internet to deliver a smoking cessation programme, cardiac and nutrition educational programmes, behavioural interventions for headache and weight loss, and pharmacy and augmentative services. All studies showed some positive effects on health outcomes, although the methodological quality of many studies was poor. Conclusions Despite widespread consumer Internet use to obtain health‐care information, there is almost a complete lack of evidence of any effects this may have on health outcomes.
The effect of qualitative vs. quantitative presentation of probability estimates on patient decision‐making: a randomized trial
Authors: Man‐Son‐Hing Malcolm , O'Connor Annette M. , Drake Elizabeth , Biggs Jennifer , Hum Valerie , Laupacis Andreas 
Published: March 2003

AbstractBackground  Given the greater uncertainty surrounding probability estimates associated with qualitative (use of words or phrases) descriptions, the use of quantitative (numerical) information to communicate the risks and benefits of therapies is recommended but the impact of its use in decision aids is unexplored.Objective  Using stroke prevention in atrial fibrillation as an example, to compare the impact of quantitative vs. qualitative descriptions of probability risk estimates in decision aids on the clinical decision‐making process.Design  Randomized trial with a 2 × 2 factorial design.Subjects  A total of 198 volunteers aged 60–80 years.Setting  Outpatient clinics of a university‐affiliated, tertiary‐care teaching hospital.Methods  Participants were asked to imagine that they had atrial fibrillation, and using a decision aid, were then randomized to two ways of receiving pertinent risk information regarding the probability of stroke and major bleeding when taking warfarin, aspirin or no therapy: (1) quantitatively, in which the 2‐year probabilities of stroke and major haemorrhage were presented both numerically and graphically with 100 faces (e.g. 8 of 100), and (2) qualitatively in which these probabilities were presented with the use of verbal phrases (e.g. very low, moderate).Outcome measures  Primary: decisional conflict. Secondary: participants' choices, knowledge and expectations of outcomes using qualitative and quantitative scales.Results  Participants reviewing quantitative risk information scored better on the informed subscale of the decisional conflict scale (P < 0.05) and, as expected, were better able to estimate numerically their chance of stroke and bleeding when taking warfarin, aspirin or no medication. For the low risk arm, there were no significant differences in treatment choices for the qualitative and quantitative groups. For the moderate risk arm, treatment choices between the two groups were significantly different (P = 0.01), with those in the quantitative group more likely to make an actual choice and to choose therapies at the extremes of effectiveness (warfarin and no treatment). There were no significant differences between the quantitative and qualitative groups in their ability to rank‐order their stroke risk when taking warfarin, aspirin and no treatment, overall knowledge about atrial fibrillation and its treatment, and other dimensions of decisional conflict (all P‐values >0.05).Conclusions  For participants without the disease in question, this study found that providing sufficient quantitative risk information makes them feel more informed, which sometimes affects their treatment choices. Further studies are necessary to confirm these findings for patients making actual clinical decisions.
Structure of the O‐polysaccharide and classification of Proteus mirabilis strain G1 in Proteus serogroup O3
Authors: Sidorczyk Zygmunt , Zych Krystyna , Toukach Filip V. , Arbatsky Nikolay P. ,   Agnieszka Zablotni, Shashkov Alexander S. , Knirel Yuriy A. 
Published: March 2003

The O‐chain polysaccharide of the lipopolysaccharide (LPS) of a previously nonclassified strain of Proteus mirabilis termed G1 was studied by sugar analysis and 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, rotating‐frame NOE (ROESY), H‐detected 1H,13C HMQC, and heteronuclear multiple‐bond correlation (HMBC) experiments. The following structure of the polysaccharide was established:where d‐GalA6(l‐Lys) stands for Nα‐(d‐galacturonoyl)‐	l‐lysine.The structure of the O‐polysaccharide of P. mirabilis G1 is similar, but not identical, to that of P. mirabilis S1959 and OXK belonging to serogroup O3. Immunochemical studies with P. mirabilis G1 and S1959 anti‐(O‐polysaccharide) sera revealed close LPS‐based serological relatedness of P. mirabilis G1 and S1959, and therefore it was suggested to classify P. mirabilis G1 in serogroup O3 as a subgroup. P. mirabilis G1 and S1959	anti‐(O‐polysaccharide) sera also cross‐reacted with LPS of␣P. mirabilis strains from two other serogroups containing␣d‐GalA6(l‐Lys) in the O‐polysaccharide or in the core region.
Regulation of α1,3galactosyltransferase expression in pig endothelial cells
Authors: Mercier Dominique , Charreau Beatrice , Wierinckx Anne , Keijser Remco , Adriaensens Lize , van den Berg Renate , Joziasse David H. 
Published: March 2003

The disaccharide galactoseα1,3galactose (the αGal epitope) is the major xenoantigen responsible for the hyperacute vascular rejection occurring in pig‐to‐primates organ transplantation. The synthesis of the αGal epitope is catalyzed by the enzyme α1,3‐galactosyltransferase (α1,3GalT). To be able to control porcine α1,3GalT gene expression specifically, we have analyzed the upstream portion of the α1,3GalT gene, and identified the regulatory sequences.Porcine α1,3GalT transcripts were detected by 5′ RACE analysis, and the corresponding genomic sequences were isolated from a phage library. The porcine α1,3GalT gene consists of at least 10 different exons, four of which contain 5′ untranslated sequence. Four distinct promoters, termed A–D, drive α1,3GalT gene transcription in porcine cells. A combination of alternative promoter usage and alternative splicing produces a series of transcripts that differ in their 5′ portion, but encode the same protein.Promoters A–C have been isolated, and functionally characterized using luciferase reporter gene assays in transfected porcine endothelial cells (PEC‐A). Promoter preference in porcine endothelial cells was estimated on the basis of relative transcript levels as determined by real‐time quantitative PCR. More than 90% of the α1,3GalT transcripts in PEC‐A cells originate from promoter B, which has characteristics of a housekeeping gene promoter. While promoter preference remains unchanged, α1,3GalT mRNA levels increase by 50% in 12 h upon tumour necrosis factor α‐activation of PEC‐A cells. However, the magnitude of this change induced by inflammatory conditions could be insufficient to affect cell surface α1,3‐galactosylation.
Purification and characterization of VanXYC, a d,d‐dipeptidase/d,d‐carboxypeptidase in vancomycin‐resistant Enterococcus gallinarum BM4174
Authors: Podmore Adrian H. B. , Reynolds Peter E. 
Published: March 2003

VanXYC, a bifunctional enzyme from VanC‐phenotype Enterococcus gallinarum BM4174 that catalyses d,d‐peptidase and d,d‐carboxypeptidase activities, was purified as the native protein, as a maltose‐binding protein fusion and with an N‐terminal tag containing six histidine residues. The kinetic parameters of His6–VanXYC were measured for a variety of precursors of peptidoglycan synthesis involved in resistance: for d‐Ala‐d‐Ala, the Km was 3.6 mm and kcat, 2.5 s−1; for UDP‐MurNAc‐L‐Ala‐d‐Glu‐L‐Lys‐d‐Ala‐d‐Ala (UDP‐MurNAc‐pentapeptide[Ala]), Km was 18.8 mm and kcat 6.2 s−1; for d‐Ala‐d‐Ser, Km was 15.5 mm and kcat 0.35 s−1. His6–VanXYC was inactive against the peptidoglycan precursor UDP‐MurNAc‐l‐Ala‐d‐Glu‐L‐Lys‐d‐Ala‐d‐Ser (UDP‐MurNAc‐pentapeptide[Ser]). The rate of hydrolysis of the terminal d‐Ala of UDP‐MurNAc‐pentapeptide[Ala] was inhibited 30% by 2 mm d‐Ala‐d‐Ser or UDP‐MurNAc‐pentapeptide[Ser]. Therefore preferential hydrolysis of substrates terminating in d‐Ala would occur during peptidoglycan synthesis in E. gallinarum BM4174, leaving precursors ending in d‐Ser with a lower affinity for glycopeptides to be incorporated into peptidoglycan.Mutation of an aspartate residue (Asp59) of His‐tagged VanXYC corresponding to Asp68 in VanX to Ser or Ala, resulted in a 50% increase and 73% decrease, respectively, of the specificity constant (kcat/Km) for d‐Ala‐d‐Ala. This situation is in contrast to VanX in which mutation of Asp68→Ala produced a greater than 200 000‐fold decrease in the substrate specificity constant. This suggests that Asp59, unlike Asp68 in VanX, does not have a pivotal role in catalysis.
Characterization of the 5′ untranslated region of α and β isoforms of the human thromboxane A2 receptor (TP)
Authors: Coyle Adrian T. , Miggin Sinead M. , Kinsella B. Therese 
Published: March 2003

In humans, thromboxane (TX) A2 signals through two TXA2 receptor (TP) isoforms, TPα and TPβ, that diverge within their carboxyl terminal cytoplasmic (C) tail regions and arise by differential splicing. The human TP gene contains three exons E1–E3; while E1 exclusively encodes 5′ untranslated region (UTR) sequence, E2 and E3 represent the main coding exons. An additional noncoding exon, E1b was identified within intron 1. Additionally, the TP gene contains two promoters P1 and P2 located 5′ of E1 and E1b, respectively.Herein, we investigated the molecular basis of the differential expression of the TP isoforms by characterizing the 5′ UTR of the TP transcripts. While E1 and E1b were found associated with TP transcript(s), their expression was mutually exclusive. 5′ rapid amplification of cDNA ends (5′ RACE) established that the major transcription initiation (TI) sites were clustered between −115 and −92 within E1 and at −99 within E1b. While E1 and E1b sequences were identified on TPα transcript(s), neither existed on TPβ transcript(s). More specifically, TPα and TPβ transcripts diverged within E2 and the major TI sites for TPβ transcripts mapped to −12/−15 therein. Through genetic reporter assays, a previously unrecognized promoter, termed P3, was identified on the TP gene located immediately 5′ of −12. The proximity of P3 to the TI site of TPβ suggests a role for P3 in the control of TPβ expression and implies that TPα and TPβ, in addition to being products of differential splicing, are under the transcriptional control of distinct promoters.
Structural diversity and transcription of class III peroxidases from Arabidopsis thaliana
Authors: Welinder Karen G. , Justesen Annemarie F. , Kjærsgård Inger V. H. , Jensen Rikke B. , Rasmussen Søren K. , Jespersen Hans M. , Duroux Laurent 
Published: March 2003

Understanding peroxidase function in plants is complicated by the lack of substrate specificity, the high number of genes, their diversity in structure and our limited knowledge of peroxidase gene transcription and translation. In the present study we sequenced expressed sequence tags (ESTs) encoding novel heme‐containing class III peroxidases from Arabidopsis thaliana and annotated 73 full‐length genes identified in the genome. In total, transcripts of 58 of these genes have now been observed. The expression of individual peroxidase genes was assessed in organ‐specific EST libraries and compared to the expression of 33 peroxidase genes which we analyzed in whole plants 3, 6, 15, 35 and 59 days after sowing. Expression was assessed in root, rosette leaf, stem, cauline leaf, flower bud and cell culture tissues using the gene‐specific and highly sensitive reverse transcriptase‐polymerase chain reaction (RT‐PCR).We predicted that 71 genes could yield stable proteins folded similarly to horseradish peroxidase (HRP). The putative mature peroxidases derived from these genes showed 28–94% amino acid sequence identity and were all targeted to the endoplasmic reticulum by N‐terminal signal peptides. In 20 peroxidases these signal peptides were followed by various N‐terminal extensions of unknown function which are not present in HRP. Ten peroxidases showed a C‐terminal extension indicating vacuolar targeting. We found that the majority of peroxidase genes were expressed in root. In total, class III peroxidases accounted for an impressive 2.2% of root ESTs. Rather few peroxidases showed organ specificity. Most importantly, genes expressed constitutively in all organs and genes with a preference for root represented structurally diverse peroxidases (< 70% sequence identity). Furthermore, genes appearing in tandem showed distinct expression profiles. The alignment of 73 Arabidopsis peroxidase sequences provides an easy access to the identification of orthologous peroxidases in other plant species and will provide a common platform for combining knowledge of peroxidase structure and function relationships obtained in various species.
pgaE encodes a fourth member of the endopolygalacturonase gene family from Aspergillus niger
Authors: Pařenicová Lucie , Benen Jacques A. E. , Kester Harry C. M. , Visser Jaap 
Published: March 2003

In the present study, the molecular and basic biochemical characterization of endopolygalacturonase E, the fourth Aspergillus niger N400 endopolygalacturonase, is reported. The entire endopolygalacturonase E gene consists of 1293 bp interrupted by three short introns (50, 50, and 59 bp, respectively) as concluded from the cDNA sequence. The deduced amino acid sequence comprises 378 residues that include 39 N‐terminal amino acids of the prepropeptide. The calculated Mr and pI of the mature protein are 35 584 and 3.6, respectively.Compared with other endopolygalacturonases from A. niger N400, the mature protein endopolygalacturonase E has the highest sequence identity with endopolygalacturonase C (77.6 %) followed by endopolygalacturonase I (57.6 %) and endopolygalacturonase II (54.3 %).For overproduction of endopolygalacturonase E, an A. niger multicopy strain was used that was transformed with a promoter gene fusion construct that directs expression from the glycolytic A. niger pyruvate kinase promoter. The enzyme was purified and characterized as an endopolygalacturonase based on product analysis after polygalacturonate hydrolysis and on bond cleavage frequencies of oligogalacturonates of different degree of polymerisation (n = 2−7). The pH optimum was 3.8. The Km and Vmax for polygalacturonate hydrolysis were 2.5 ± 0.4 mg ml−1 and 1.3 ± 0.2 μkat mg−1, respectively. A subsite map was calculated by the combination of the methods of Suganuma et al. [Suganuma, T., Matsuno, R., Ohnishi, M. & Hiromi, K. (1978) J. Biochem. (Tokyo) 84, 293−316] and Nitta et al. [Nitta, Y., Mizushima, M., Hiromi, K. & Ono, S. (1971) J. Biochem. (Tokyo) 69, 567−576]. This indicated that the enzyme was composed of at least five subsites.
Deletion and site‐directed mutagenesis of the Wolinella succinogenes fumarate reductase operon
Authors: Simon Jörg , Gross Roland , Ringel Michael , Schmidt Enrico , Kröger Achim 
Published: March 2003

Wolinella succinogenes is known to grow at the expense of fumarate respiration with formate or sulfide as electron donor. A W. succinogenes mutant (ΔfrdCAB) lacking the fumarate reductase operon did not grow with fumarate as terminal electron acceptor and either formate or sulfide as electron donor. The ΔfrdCAB mutant grown with formate and nitrate did not contain fumarate reductase activity and did not catalyze electron transport from sulfide to fumarate, in contrast to the nitrate‐grown wild‐type strain. A mutant constructed by integration of frdCAB into the ΔfrdCAB mutant genome showed wild‐type properties with respect to growth and enzyme activities. The frdC2 gene located downstream of the fumarate reductase operon frdCAB possibly encodes a diheme cytochrome b that is similar to FrdC (41 % identical residues). The corresponding transcript differs from that of frdCAB. A ΔfrdC2 mutant showed wild‐type properties with respect to growth and enzyme activities. Using site‐directed mutagenesis, each of the four histidine residues that are predicted to serve as the axial heme ligands in FrdC (His44, His93, His143, and His182) was replaced by alanine or other residues. The resulting mutants did not grow with formate and fumarate and did not contain fumarate reductase activity, FrdA or FrdC when grown with formate and nitrate. In contrast, substitution of two histidine residues that are not considered heme ligands, yielded mutants (H114A and H120A) that grew with fumarate.It is concluded that FrdCAB is an obligatory component of fumarate respiration with formate and with sulfide in W. succinogenes. FrdC2 is not involved in fumarate respiration. Replacement of the putative heme ligands of FrdC prevents formation of a functional fumarate reductase.
A core‐shell model of calcium phosphate nanoclusters stabilized by β‐casein phosphopeptides, derived from sedimentation equilibrium and small‐angle X‐ray and neutron‐scattering measurements
Authors: Holt Carl , Timmins Peter A. , Errington Neil , Leaver Jeffrey 
Published: March 2003

Calcium phosphate nanoclusters were prepared under standardised conditions using 10 mg ml−1 of the 25‐amino‐acid N‐terminal tryptic phosphopeptide of bovine β‐casein as a stabilising agent. The Mr determined by sedimentation equilibrium was 197 600 ± 13 700 and the apparent radius of gyration determined by X‐ray scattering was 2.80 ± 0.05 nm. A small‐angle neutron scattering contrast variation study in 1H2O/2H2O mixtures was performed and gave radii of gyration at the calculated match points for the calcium phosphate (88.2 %2H2O) and phosphopeptide (41.3 %2H2O) of 3.39 ± 0.08 nm and 1.85 ± 0.05 nm, respectively. Measurements at larger scattering wave vector showed a subsidiary maximum at about Q = 1.6 nm−1.The results are consistent with a model of the nanoclusters comprising a spherical core of 355 ± 20 CaHPO4 2 H2O units, density 2.31 g ml−1 and radius 2.30 ± 0.05 nm surrounded by 49 ± 4 peptide chains with a partial specific volume of 0.7 cm3 g−1, forming a tightly packed shell with an outer radius of 4.04 ± 0.15 nm.This model suggests that the phosphopeptide is able to arrest the process of growth of the precipitating phase of calcium phosphate at its earliest stages. A similar role for whole casein could be vital to the normal functioning of the mammary gland during milk secretion.
Functional expression of recombinant N‐methyl‐	D‐aspartate receptors in the yeast Saccharomyces cerevisiae
Authors: Li Ziyu , Becker Jürgen , Noe Christian R. 
Published: March 2003

The yeast Saccharomyces cerevisiae was used for expressing the genes encoding the ionotropic N‐methyl‐
D‐aspartate (NMDA) receptor subunits from rats (NR1a, NR2A, NR2C) and mice (NR2B). Four plasmids were constructed by cloning the different NMDA receptor genes in the two multi‐copy yeast‐Escherichia coli shuttle vectors pMB01 (←NR1a gene) and pMB02 (←NR2A‐2C genes). The protease‐deficient S. cerevisiae strain cI3‐ABYS‐86 (leu−, ura−) was transformed or co‐transformed with the resulting plasmids pMBNR1a (leu+) or pMBNR1a/pMBNR2A−C (ura+) respectively.Western blotting analysis with antibodies raised against amino acid sequences at the C‐termini of the respective subunits revealed that the recombinant receptor proteins were differently expressed and only partially glycosylated in the cell membranes of the recombinant yeast strains.The expression and localization of the recombinant NMDA receptor proteins were also proved by immunofluorescence microscopy which indicated a distinct expression of the different NMDA receptor subunits in the plasma membrane of the transformed yeast cells.Pharmacological characterization of crude membrane preparations of the recombinant yeast cells showed saturable binding of the glycine antagonist [3H]MDL105,519 with Kd values of 56.9 ± 6.19 nM (NR1a/NR2A), 26.72 ± 2.13 nM (NR1a/NR2B), and 21.22 ± 1.64 nM (NR1a/NR2C), and bound capacities of 17.94 ± 1.24 pmol/mg membrane protein (NR1a/NR2A), 11.45 ± 0.67 pmol/mg (NR1a/NR2B), and 16.15 ± 0.86 (NR1a/NR2C) pmol/mg. The [3H]MDL105,519 binding was inhibited by the glycine antagonist 5,7‐dichlorokynurenate, ethyl‐2‐carboxy‐4,6‐dichloro‐3‐indoleacetate, and itself, but not by glycine,
D‐serine or 1‐amino‐cyclopropanecarboxylic acid. Specific binding of [3H]glycine or the NMDA channel blocker [3H]dizolcipine were not observed.
Structural analysis of the phase‐variable lipooligosaccharide from Haemophilus somnus strain 738
Authors: Cox Andrew D. , Howard Michael D. , Brisson Jean‐Robert , van der Zwan Mark , Thibault Pierre , Perry Malcolm B. , Inzana Thomas J. 
Published: March 2003

The structure of the phase variable lipooligosaccharide (LOS) from Haemophilus somnus strain 738 was elucidated. The LOS was subjected to a variety of degradative procedures. The structures of the purified products were established by monosaccharide and methylation analyses, NMR spectroscopy and mass spectrometry. The following structures for the two major components were determined on the basis of the combined data from these experiments.
Kdo
PCho
2
P∣∣∣
6
4
4
β‐Gal‐1‐3‐β‐GlcNAc‐1‐3‐β‐Gal‐1‐4‐β‐Glc‐1‐4‐α‐Hep‐1‐5‐α‐Kdo‐2‐6‐β‐GlcN‐1‐6‐α‐GlcN‐1‐P
3
∣
1
α‐Hep‐6‐PEtn
Kdo
PCho
2
P∣∣∣
6
4
4
β‐Gal‐1‐3‐β‐GlcNAc‐1‐3‐β‐Gal‐1‐3‐β‐Glc‐1‐4‐β‐Glc‐1‐4‐α‐Hep‐1‐5‐α‐Kdo‐2‐6‐β‐GlcN‐1‐6‐α‐GlcN‐1‐P
3
∣
1
α‐Hep‐6‐PEtn
In the structures Kdo is 3‐deoxy‐
D‐manno‐octulosonic acid, PEtn is phosphoethanolamine, PCho is phosphocholine, Hep is
L‐glycero‐
D‐manno‐heptose, and the remaining glucose units have the
D configuration. The elucidation of these structures has increased our understanding of the relationship between the phase‐variable LOS and the pathogenic potential of this organism.