bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alcohol‐mediated haemolysis in yeast
Authors: Shuster Amir , Osherov Nir , Rosenberg Mel 
Published: November 2004

AbstractAlthough yeast are generally non‐haemolytic, we have found that addition of alcohol vapour confers haemolytic properties on many strains of yeast and other fungi. We have called this phenomenon ‘microbial alcohol‐conferred haemolysis’ (MACH). MACH is species‐ and strain‐specific: whereas all six Candida tropicalis strains tested were haemolytic in the presence of ethanol, none among 10 C. glabrata strains tested exhibited this phenomenon. Among 27 C. albicans strains and 11 Saccharomyces cerevisiae strains tested, ethanol‐mediated haemolysis was observed in 11 and 4 strains, respectively. Haemolysis is also dependent on the alcohol moiety: n‐butanol and n‐pentanol could also confer haemolysis, whereas methanol and 2‐propanol did not. Haemolysis was found to be dependent on initial oxidation of the alcohol. Reduced haemolysis was observed in specific alcohol dehydrogenase mutants of both Aspergillus nidulans and S. cerevisiae. MACH was not observed during anaerobic growth, and was reduced in the presence of pararosaniline, an aldehyde scavenger. Results suggest that initial oxidation of the alcohol to the corresponding aldehyde is an essential step in the observed phenomenon. Copyright © 2004 John Wiley & Sons, Ltd.
Expression and secretion of a prokaryotic protein streptokinase without glycosylation and degradation in Schizosaccharomyces pombe
Authors: Kumar Raj , Singh Jagmohan 
Published: November 2004

AbstractStreptokinase (SK) is an important thrombolytic protein that is secreted by pathogenic strains of Streptococcus. Expression of streptokinase has been so far attempted in Pichia pastoris, Escherichia coli and Bacillus subtilis and shown to yield protein that was either highly glycosylated or degraded. Since the fission yeast, Schizosaccharomyces pombe, shares several molecular characteristics with higher eukaryotes, we decided to express the streptokinase gene in this yeast. A chimeric gene comprising the signal sequence of the Plus pheromone of Sz. pombe fused in‐frame with the mature streptokinase from Streptococcus sp. was constructed and inserted into the expression vector containing the thiamine‐regulated promoter. We obtained a high level of expression of streptokinase comparable to that in E. coli and P. pastoris, with 50–100% processing of the signal sequence and secretion of the mature streptokinase into the periplasmic fraction. The mature enzyme co‐migrates with the authentic mature SK in SDS gels, lacks any major modification and is functional. Importantly, a higher level of expression under stationary phase conditions and improved extractability of the mature and undegraded streptokinase was achieved in a novel mutant of Sz. pombe defective for a potent extracellular protease activity. We suggest that the unique vector/strain system developed here could be advantageous for large‐scale production of prokaryotic proteins without significant modification or degradation in Sz. pombe. Copyright © 2004 John Wiley & Sons, Ltd.
YAP4 gene expression is induced in response to several forms of stress in Saccharomyces cerevisiae
Authors: Nevitt Tracy , Pereira Jorge , Rodrigues‐Pousada Claudina 
Published: November 2004

AbstractExposure of Saccharomyces cerevisiae to several environmental insults, including conditions of oxidative, heavy metal, metalloid and heat stress, induces the expression of the YAP4 gene, previously shown to play a role in the response to hyperosmotic stress. Expression analyses in several mutant strains under pro‐oxidant conditions have determined that YAP4 is regulated by the transactivators Yap1p and Msn2p. Mutation of either the Yap1p‐response element (YRE), located at − 517 bp from the ATG, or the most proximal stress response element (STRE) at −430 bp, is shown to strongly compromise YAP4 gene expression under these conditions. Furthermore, these two mutations in combination lead to a severe depletion of detectable mRNA levels, indicating interplay between the transcription factors Yap1p and Msn2p in the regulation of YAP4 transcription. Transcriptional activation of this gene reflects a concomitant increase in Yap4p protein levels that appear phosphorylated upon stress and negatively regulated by protein kinase A. Yap4p amino acid residues Ser89, Ser196 and Thr241 are shown to be required for protein phosphorylation and/or protein stability. Copyright © 2004 John Wiley & Sons, Ltd.
The risks and benefits of participating in trauma‐focused research studies
Authors: Newman Elana , Kaloupek Danny G. 
Published: November 2004

AbstractConcern about minimizing harm and maximizing benefit has been particularly acute with regard to the scientific study of individuals exposed to potentially traumatic events such as terrorist attack or disaster. This review outlines conceptual and practical issues and summarizes available evidence regarding potential risks and benefits of participation in trauma‐related research. Current, limited evidence suggests that most individuals make favorable cost–benefit appraisals regarding their participation. Although a subset of participants report strong negative emotions or unanticipated distress, the majority of these do not regret or negatively evaluate the overall experience. Continuing efforts are needed to identify individuals at risk for unfavorable reactions to research participation. A systematic empirical approach to evaluating participant experience in all human research is recommended.
The concept of vulnerability in disaster research
Authors: Levine Carol 
Published: November 2004

AbstractThe concept of vulnerability in research derives from a specific set of historical circumstances relating to abuses in biomedical research. Now so many people and groups have been labeled vulnerable that the concept has lost much of its force. In disaster research, participants should not be automatically considered vulnerable unless they are legally designated as such, for example, children. Instead specific aspects of the research should be thoroughly examined. Examples are the potential for the participants to be pressured to participate in several protocols, political or social turmoil surrounding the disaster, and cognitive impairments or mental health problems. In addition to a careful consent process, there should be procedures in place to provide assistance to participants who experience serious distress.
Multidrug transporter activity in lymphocytes
Authors: Elliott James I , Raguz Selina , Higgins Christopher F 
Published: November 2004

Multidrug transporters play a dual role in haematopoietic cells, mediating the efflux of xenobiotics and regulating cell migration.
For several reasons including the lack of specific antibodies, reports of multidrug transporter distribution on lymphocytes conflict. Murine B cells have been reported to completely lack transporter activity.
Through analysis of parental and ‘knockout’ mice we show that, contrary to previous studies, murine B and T lymphocytes possess at least three active multidrug transporters and also a hitherto unrecognised drug‐specific import activity.
Surprisingly, the drug specificity of P‐glycoprotein appears cell type dependent. The data indicate that a range of developmentally regulated, multidrug transporters can impose a barrier to treatment of immune disorders.

British Journal of Pharmacology (2004) 143, 899–907. doi:10.1038/sj.bjp.0705940
Effects of pH on Helicobacter pylori binding to human gastric mucins: identification of binding to non-MUC5AC mucins
Authors: LINDÉN Sara , MAHDAVI Jafar , HEDENBRO Jan , BORÉN Thomas , CARLSTEDT Ingemar 
Published: November 2004

Helicobacter pylori causes gastritis, peptic ulcer disease and gastric cancer. The microbe is found in the gastric mucus layer where a pH gradient ranging from acidic in the lumen to neutral at the cell surface is maintained. The aim of the present study was to investigate the effects of pH on H. pylori binding to gastric mucins from healthy individuals. At pH 3, all strains bound to the most charged MUC5AC glycoform and to a putative mucin of higher charge and larger size than subunits of MUC5AC and MUC6, irrespective of host blood-group. In contrast, at pH 7.4 only Leb-binding BabA-positive strains bound to Leb-positive MUC5AC and to smaller mucin-like molecules, including MUC1. H. pylori binding to the latter component(s) seems to occur via the H-type-1 structure. All strains bound to a proteoglycan containing chondroitin sulphate/dermatan sulphate side chains at acidic pH, whereas binding to secreted MUC5AC and putative membrane-bound strains occurred both at neutral and acidic pH. The binding properties at acidic pH are thus common to all H. pylori strains, whereas mucin binding at neutral pH occurs via the bacterial BabA adhesin and the Leb antigen/related structures on the glycoprotein. Our work shows that microbe binding to membrane-bound mucins must be considered in H. pylori colonization, and the potential of these glycoproteins to participate in signalling events implies that microbe binding to such structures may initiate signal transduction over the epithelial layer. Competition between microbe binding to membrane-bound and secreted mucins is therefore an important aspect of host–microbe interaction.
Membrane insertion of the N-terminal α-helix of equinatoxin II, a sea anemone cytolytic toxin
Authors: GUTIÉRREZ-AGUIRRE Ion , BARLIČ Ariana , PODLESEK Zdravko , MAČEK Peter , ANDERLUH Gregor , GONZÁLEZ-MAÑAS Juan M. 
Published: November 2004

Equinatoxin II (Eqt-II) is a member of the actinoporins, a unique family of cytotoxins comprising 20 kDa pore-forming proteins isolated from sea anemones. Actinoporins bind preferentially to lipid membranes containing sphingomyelin, and create cation-selective pores by oligomerization of three to four monomers. Previous studies have shown that regions of Eqt-II crucial for its cytolytic mechanism are an exposed aromatic cluster and the N-terminal region containing an amphipathic α-helix. In the present study, we have investigated the transfer of the N-terminal α-helix into the lipid membrane by the use of three mutants containing an additional tryptophan residue in different positions within the amphipathic α-helix (Ile18→Trp, Val22→Trp and Ala25→Trp). The interaction of the mutants with different model systems, such as lipid monolayers, erythrocytes and ghost membranes, was extensively characterized. Intrinsic fluorescence measurements and the use of vesicles containing brominated phospholipids indicated a deep localization of the N-terminal amphipathic helix in the lipid bilayer, except for the case of Val22→Trp. This mutant is stabilized in a state immediately prior to final pore formation. The introduction of additional tryptophan residues in the sequence of Eqt-II has proved to be a suitable approach to monitor the new environments that surround defined regions of the molecule upon membrane interaction.
Characterization of Staufen 1 ribonucleoprotein complexes
Authors: BRENDEL Cornelia , REHBEIN Monika , KREIENKAMP Hans-Jürgen , BUCK Friedrich , RICHTER Dietmar , KINDLER Stefan 
Published: November 2004

In Drosophila oocytes and neuroblasts, the double-stranded RNA binding protein Staufen assembles into ribonucleoprotein particles, which mediate cytoplasmic mRNA trafficking and translation. Two different mammalian orthologues also appear to reside in distinct RNA-containing particles. To date, relatively little is known about the molecular composition of Staufen-containing ribonucleoprotein complexes. Here, we have used a novel one-step affinity purification protocol to identify components of Staufen 1-containing particles. Whereas the nucleocytoplasmic RNA-binding protein nucleolin is linked to Staufen in an RNA-dependent manner, the association of protein phosphatase 1, the microtubule-dependent motor protein kinesin and several components of the large and small ribosomal subunits with Staufen ribonucleoprotein complexes is RNA-independent. Notably, all these components do not co-purify with a second RNA-binding protein, hnRNPK (heterogeneous ribonucleoprotein K), demonstrating the high specificity of the purification protocol. Furthermore, pull-down and immunoprecipitation experiments suggest a direct interaction between Staufen 1 and the ribosomal protein P0 in vitro as well as in cells. In cell fractionation and sucrose gradient assays, Staufen co-fractionates with intact ribosomes and polysomes, but not with the isolated 40 S ribosomal subunit. Taken together, these findings imply that, in the cytoplasm of mammalian cells, an association with the ribosomal P-stalk protein P0 recruits Staufen 1 into ribosome-containing ribonucleoprotein particles, which also contain kinesin, protein phosphatase 1 and nucleolin.
Myocardial Performance Index with Sevoflurane–Pancuronium versus Fentanyl–Midazolam–Pancuronium in Infants with a Functional Single Ventricle
Authors: Ikemba Catherine M. , Su Jason T. , Stayer Stephen A. , Miller-Hance Wanda C. , Eidem Benjamin W. , Bezold Louis I. , Hall Stuart R. , Havemann Luke M. , Andropoulos Dean B. 
Published: November 2004

Background
Patients with congenital heart disease characterized by a functional single ventricle make up an increasing number of patients presenting for cardiac or noncardiac surgery. Conventional echocardiographic methods to measure left ventricular function, i.e., ejection fraction, are invalid in these patients because of altered ventricular geometry. Two recently described Doppler echocardiographic modalities, the myocardial performance index and Doppler tissue imaging, can be applied to single-ventricle patients because they are independent of ventricular geometry. This study assessed the changes in myocardial performance index and Doppler tissue imaging in response to two anesthetic regimens, fentanyl-midazolam-pancuronium and sevoflurane-pancuronium.

Methods
Thirty patients aged 4-12 months with a functional single ventricle were randomized to receive fentanyl-midazolam or sevoflurane. Myocardial performance index and Doppler tissue imaging were measured by transthoracic echocardiography at baseline and two clinically relevant dose levels.

Results
Sixteen patients receiving sevoflurane and 14 receiving fentanyl-midazolam were studied. Myocardial performance index was unchanged from baseline with either agent (fentanyl-midazolam: 0.50 +/- 15 baseline vs. 0.51 +/- 0.15 at dose 2; sevoflurane: 0.42 +/- 0.14 baseline vs. 0.46 +/- 0.09 at dose 2). Doppler tissue imaging S (systolic)- and E (early diastolic)-wave velocities in the lateral ventricular walls at the level of the atrioventricular valve annulus were unchanged in the sevoflurane group; however, both Doppler tissue imaging S- and E-wave velocities were decreased significantly from baseline at dose 1 and dose 2 with fentanyl-midazolam, consistent with decreased longitudinal systolic and diastolic ventricular function.

Conclusions
Myocardial performance index, a global measurement of combined systolic and diastolic ventricular function, is not affected by commonly used doses of fentanyl-midazolam or sevoflurane in infants with a functional single ventricle.
Probenecid Interacts with the Pharmacokinetics of Morphine-6-glucuronide in Humans
Authors: Skarke Carsten , Langer Michael , Jarrar Marwan , Schmidt Helmut , Geisslinger Gerd , Lötsch Jörn 
Published: November 2004

Background
Evidence obtained from porcine cell cultures and experiments in laboratory animals indicates that transmembrane transporters may play a role in the distribution of the active morphine metabolite morphine-6-glucuronide (M6G). This was evaluated in a study in healthy volunteers.

Methods
Ten subjects received an intravenous M6G infusion for 30 min at a dosage of 0.5 mg/kg body weight, leading to M6G plasma concentrations approximately two to three times higher than those observed with analgesic morphine doses in subjects with normal kidney function. In a randomized, double-blind, three-way crossover fashion, subjects received 800 mg quinidine for inhibition of P-glycoprotein; 500 mg probenecid for inhibition of other transporters, including organic anion transporter peptide, multidrug resistance-related protein, and organic anion transporter families; or placebo 1 h before the start of M6G administration. Plasma concentrations of M6G and pupil size were measured for 7 h.

Results
Probenecid pretreatment resulted in a decrease in the clearance of M6G from 8.3 +/- 1 l/h to 6.7 +/- 1.3 l/h (factor of 0.8; P < 0.05 vs. placebo cotreatment). This was paralleled by an increase by a factor of 1.2 of the area under the miotic effect-versus-time curves (P < 0.05 vs. placebo). In contrast, quinidine pretreatment had no influence on the pharmacokinetics of M6G.

Conclusions
The active morphine metabolite is subject to transmembrane transport by transporters inhibited by probenecid in humans.
Efficacy of a Prophylactic Epidural Blood Patch in Preventing Post Dural Puncture Headache in Parturients after Inadvertent Dural Puncture
Authors: Scavone Barbara M. , Wong Cynthia A. , Sullivan John T. , Yaghmour Edward , Sherwani Saadia S. , McCarthy Robert J. 
Published: November 2004

Background
Postdural puncture headache (PDPH) occurs in up to 80% of parturients who experience inadvertent dural puncture during epidural catheter placement. The authors performed a randomized double blind study to assess the effect of prophylactic epidural blood patch on the incidence of PDPH and the need for therapeutic epidural blood patch.

Methods
Sixty-four parturients who incurred inadvertent dural puncture were randomized to receive a prophylactic epidural blood patch with 20 ml autologous blood (prophylactic epidural blood patch group) or a sham patch (sham group). Subjects were evaluated daily for development of PDPH for a minimum of 5 days after dural puncture. Those who developed a PDPH were followed daily for a minimum of 3 days after resolution of the headache. Subjects with moderate headaches who reported difficulties performing childcare activities and all those with severe headaches were advised to receive a therapeutic epidural blood patch.

Results
Eighteen of 32 subjects in each group (56%) developed PDPH. Therapeutic blood patch was recommended in similar numbers of patients in each group. The groups had similar onset time of PDPH, median peak pain scores, and number of days spent unable to perform childcare activities as a result of postural headache. The median duration of PDPH, however, was shorter in the prophylactic epidural blood patch group.

Conclusions
A decrease in the incidence of PDPH or the need for criteria-directed therapeutic epidural patch was not detected when a prophylactic epidural blood patch was administered to parturients after inadvertent dural puncture. However, prophylactic epidural blood patch did shorten the duration of PDPH symptoms.
PHOSPHOENOLPYRUVATE CARBOXYKINASE ACTIVITY IN ASCOPHYLLUM NODOSUM (PHAEOPHYCEAE)1
Authors: Kerby Nigel W. , Evans Leonard V. 
Published: November 2004

ABSTRACTPEP‐dependent4 CO2‐fixation by extracts of Ascophyllum nodosum (L.) Le Jol. is reported. The carboxylation of PEP is Mn2+ dependent and ATP is shown to be a product. IDP was found to be less efficient as a phosphate acceptor than ADP and 3‐mercaptopicolinic acid inhibited the carboxylation reaction. Extracts decarboxylated OAA only in the presence of ATP and had high activities of MDH and GOT. This evidence, together with the probable absence of PEPC, PEPCTrP, and PC in A. nodosum extracts, favors the view that PEPCK is responsible for the light‐independent CO2‐fixation observed in this alga.
SHORT‐TERM STANDING CROP AND DIVERSITY OF PERIPHYTIC DIATOMS IN A EUTROPHIC RESERVOIR1
Authors: Hoagland Kyle D. 
Published: November 2004

ABSTRACTAdverse weather and resultant turbulence caused sloughing of attached diatom communities during the first two weeks of colonization on artificial substrates. In contrast to Pacific macroalgal systems, older communities (8–12 d) were the most affected by wave action. Ash‐free dry weight of the periphyton and diatom cell density generally increased, except following periods of high turbulence when losses of up to 80% occurred. The maximum cell density (4 × 105 diatoms · cm−2) and ash‐free dry weight (2.9 mg · cm−2) are among the highest reported for similar conditions. Percent transmittance through the growth layer correlated significantly with cell density and ash‐free dry weight and is recommended as a rapid method for measuring the relative accumulation of periphyton. Diatom diversity generally increased throughout the study period and did not clearly reflect the effects of disturbance as did standing crop. Comparisons of diatom diversity and community composition indicated that the three overlapping growth series were not significantly different and samples collected on the same date were not more similar than those of identical age. Combined with previous evidence, the present study indicates that the first two weeks of substrate exposure in the summer represented a colonization phase followed by rapid microsuccession.
EFFECT OF COPPER ON GROWTH, SILICIC ACID UPTAKE AND SOLUBLE POOLS OF SILICIC ACID IN THE MARINE DIATOM, THALASSIOSIRA WEISFLOGII (BACILLARIOPHYCEAE)1
Authors: Rueter John G. 
Published: November 2004

ABSTRACTThe toxicity of Cu to Thalassiosira weissflogii (Grunow) was investigated, focusing on the internal soluble pool of silicic acid. Silicic acid uptake and growth rates were found to be functions of both the cupric ion activity and the concentration of silicic acid in the growth medium. The soluble pool of Si per cell depended on the balance between the uptake rate and the division rate. The soluble pool in non‐dividing cultures reflected simply the uptake rate (and inhibition by copper of the uptake rate), but in dividing cultures the soluble pools had complex patterns with time depending on uptake rates and timing of division. Intracellular soluble pools of silicic acid are a good indicator for the relative inhibition of uptake and growth processes.
AGGLUTINATION OF THE CHLOROPHYCEAN FLAGELLATE DUNALIELLA TERTIOLECTA BY TREATMENT WITH LECTINS OR DIVALENT CATIONS AT ALKALINE pH1
Authors: Klut M. Emilia , Bisalputra Thana , Antia Naval J. 
Published: November 2004

ABSTRACTWashed cells of Dunaliella tertiolecta Butcher became immobile and agglutinated upon exposure to 100–400 μ/mL lectins in NaCl solution. The agglutinations were strongest with Limulus polyphemus agglutinin and wheat‐germ agglutinin, moderate with soybean agglutinin and weakest with Concanavalin A. All lectin‐induced agglutinations were inhibited or mitigated by the simultaneous presence of specific lectin‐binding sugars. The differential sensitivity of the alga to these lectins suggested that sialic acid and/or N‐acetyl‐D‐glucosamine might be the predominant lectin‐receptor sugars in the algal surface coat, with N‐acetyl‐D‐galactosamine likely present as a lesser component. In the absence of lectins, the divalent cations Mg2+, Ca2+ or Mn2+ also caused agglutination, but this process required an alkaline pH of at least ca. 8.6–8.9. Such cation‐induced agglutination was reversibly inhibited by the cation complexing agent EDTA as well as by lowering the pH below 8.0. SEM observations of the agglutinations revealed random flagellar attachments as well as direct body contact between agglutinated cells.
BRYOBESIA JOHANNAE, A SMALL TROPICAL REPRESENTATIVE OF THE ORDER CLADOPHORALES (CHLOROPHYCEAE)1
Authors: van den Hoek Christiaan 
Published: November 2004

ABSTRACTThe small and ill‐known tropical chlorophyte, Brybesia johannae Weber‐van Bosse, is redescribed on the basis of living material from the coral reef of Curacao, Netherlands Antilles. Additional records are given from the Canary Islands. One species, B. johannae, is recognized (including, B. cylindrocarpa Howe 1920), and this probably has a wide Atlantic and Indo‐Pacific tropical distribution. Bryobesia is not related to Bryopsis and Derbesia (Caulerpales), but belongs to the Cladophorales. It appears to be a rudimentary Cladophora.