bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure analysis of a soil community of predatory bacteria using culture‐dependent and culture‐independent methods reveals a hitherto undetected diversity of Bdellovibrio‐and‐like organisms
Authors: Davidov Yaacov , Friedjung Avital , Jurkevitch Edouard 
Published: May 2006

Summary Bdellovibrio‐and‐like organisms (BALOs) are widespread obligatory predators of other Gram‐negative bacteria. Their detection by culture‐dependent methods is complicated as their replication is totally dependent upon the availability of an appropriate prey. Because BALOs do not form numerically dominant groups within microbial communities, non‐specific culture‐independent tools also generally fail to detect them. We designed sets of 16S rRNA primers that specifically target BALOs. Polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) were combined, yielding partial 16S rDNA sequences. This simple method that allows specific in situ culture‐independent detection of BALOs was applied to the soil environment. Bdellovibrio‐and‐like organisms were also isolated from the same soil and the phylogeny and prey range of the isolates analysed. Seventeen isolates retrieved using five different potential preys exhibited eight different spectra of prey utilization and formed nine operational taxonomic units (OTUs). These OTUs were affiliated with the Bdellovibrionaceae, Bacteriovorax, Peredibacter or Micavibrio, i.e. the known BALO groups. In comparison, 15 OTUs including 10 that were not detected by the culture‐dependent approach were obtained using the specific primers in a PCR‐DGGE approach. The occurrence of a complex BALO community suggests that predation occurs on a much wider range of prey than can be detected by the classical culture‐dependent technique.
Maximum growth rates and possible life strategies of different bacterioplankton groups in relation to phosphorus availability in a freshwater reservoir
Authors: Šimek Karel , Horňák Karel , Jezbera Jan , Nedoma Jiří , Vrba Jaroslav , Straškrábová Viera , Macek Miroslav , Dolan John R. , Hahn Martin W. 
Published: May 2006

SummaryWe investigated net growth rates of distinct bacterioplankton groups and heterotrophic nanoflagellate (HNF) communities in relation to phosphorus availability by analysing eight in situ manipulation experiments, conducted between 1997 and 2003, in the canyon‐shaped Římov reservoir (Czech Republic). Water samples were size‐fractionated and incubated in dialysis bags at the sampling site or transplanted into an area of the reservoir, which differed in phosphorus limitation (range of soluble reactive phosphorus concentrations – SRP, 0.7–96 µg l−1). Using five different rRNA‐targeted oligonucleotide probes, net growth rates of the probe‐defined bacterial groups and HNF assemblages were estimated and related to SRP using Monod kinetics, yielding growth rate constants specific for each bacterial group. We found highly significant differences among their maximum growth rates while insignificant differences were detected in the saturation constants. However, the latter constants represent only tentative estimates mainly due to insufficient sensitivity of the method used at low in situ SRP concentrations. Interestingly, in these same experiments HNF assemblages grew significantly faster than any bacterial group studied except for a small, but abundant cluster of Betaproteobacteria (targeted by the R‐BT065 probe). Potential ecological implications of different growth capabilities for possible life strategies of different bacterial phylogenetic lineages are discussed.
Chemostat‐based proteomic analysis of toluene‐affected Pseudomonas putida S12
Authors: Volkers Rita J. M. , De Jong Ad L. , Hulst Albert G. , Van Baar Ben L. M. , De Bont Jan A. M. , Wery Jan 
Published: May 2006

SummaryThe aim of this study was to assess the cellular response of the solvent‐tolerant Pseudomonas putida S12 to toluene as the single effector. Proteomic analysis (two‐dimensional difference‐in‐gel‐electrophoresis) was used to assess the response of P. putida S12 cultured in chemostats. This approach ensures constant growth conditions, both in the presence and absence of toluene. A considerable negative effect of toluene on the cell yield was found. The need for energy in the defence against toluene was reflected by differentially expressed proteins for cell energy management. In toluene‐stressed cells the balance between proton motive force (PMF) enforcing and dissipating systems was shifted. NAD(P)H generating systems were upregulated whereas the major proton‐driven system, ATP synthase, was downregulated. Other differentially expressed proteins were identified: outer membrane proteins, transport proteins, stress‐related proteins and translation‐related proteins. In addition, a protein with no assigned function was found. This study yielded a more detailed view of the effect of toluene on the intracellular energy management of P. putida S12 and several novel leads have been obtained for further targeted investigations.
Persistent high rates of hysterectomy in Western Australia: a population‐based study of 83 000 procedures over 23 years
Authors: Spilsbury K , Semmens JB , Hammond I , Bolck A 
Published: May 2006

Objective  To investigate incidence trends and demographic, social and health factors associated with the rate of hysterectomy and morbidity outcomes in Western Australia and compare these with international studies.Design  Population‐based retrospective cohort study.Setting  All hospitals in Western Australia where hysterectomies were performed from 1981 to 2003.Population  All women aged 20 years or older who underwent a hysterectomy.Methods  Statistical analysis of record‐linked administrative health data.Main outcome measures  Rates, rate ratios and odds ratios for incidence measures and length of stay in hospital and odds ratios for morbidity measures.Results  The age‐standardised rate of hysterectomy adjusted for the underlying prevalence of hysterectomy decreased 23% from 6.6 per 1000 woman‐years (95% CI 6.4–6.9) in 1981 to 4.8 per 1000 woman‐years (95% CI 4.6–4.9) in 2003. Lifetime risk of hysterectomy was estimated as 35%. In 2003, 40% of hysterectomies were abdominal. The rate of hysterectomy to treat menstrual disorders fell from 4 per 1000 woman‐years in 1981 to 1 per 1000 woman‐years in 1993 and has since stabilised. Low socio‐economic status, having only public health insurance, nonindigenous status and living in rural or remote areas were associated with increased risk of having a hysterectomy for menstrual disorders. Indigenous women had higher rates of hysterectomy to treat gynaecological cancers compared with nonindigenous women, particularly in rural areas. The odds of a serious complication were 20% lower for vaginal hysterectomies compared with abdominal procedures.Conclusion  Western Australia has one of the highest hysterectomy rates in the world, although proportionally, significantly fewer abdominal hysterectomies are performed than in most countries.
The effect of metformin on fat distribution and the metabolic syndrome in women with polycystic ovary syndrome—a randomised, double‐blind, placebo‐controlled trial
Authors: Lord J , Thomas R , Fox B , Acharya U , Wilkin T 
Published: May 2006

Objective  To establish whether metformin has a significant action in reducing visceral fat and improving other metabolic parameters in women with polycystic ovary syndrome (PCOS).Design  Randomised, double‐blind, placebo‐controlled trial.Setting  Reproductive medicine clinic.Population  Forty women with anovulatory PCOS.Methods  Participants were randomised into receiving metformin 500 mg three times a day or placebo for 3 months.Main outcome measures  Fat distribution was measured by computed tomography scan. Secondary outcome measures included serum indices of the metabolic syndrome and evidence of ovulation.Results  We found no significant differences in any of the measures of fat distribution between the placebo and metformin groups. The metformin group had significantly lower total cholesterol (P= 0.02), low‐density lipoprotein cholesterol (P= 0.02) and cholesterol:high‐density lipoprotein cholesterol ratio (P= 0.05), but there was no statistically significant treatment effect on androgens, insulin, insulin resistance, triglycerides, ovulation or pregnancy.Conclusions  Metformin has no clinically significant effect in reducing visceral fat mass, although it does have a beneficial effect on lipids. This trial lends support to the growing evidence that metformin is not a weight loss drug. Metformin might therefore be used as an adjunct to lifestyle modification in women with PCOS, but not as a substitute for it.
Second messenger and Ras/MAPK signalling pathways regulate CLOCK/CYCLE‐dependent transcription
Authors: Weber Frank , Hung Hsiu‐Cheng , Maurer Christian , Kay Steve A. 
Published: May 2006

AbstractThe heterodimeric complex of the transcription factors CLOCK (CLK) and CYCLE (CYC) constitutes the positive element of the circadian clock in Drosophila and mammals. Phosphorylation of clock proteins represents an essential mechanism for promotion and control of the molecular oscillator. However, the kinases and signalling pathways that regulate CLK/CYC function remain largely elusive. In the present study we performed a chemical screen of kinase inhibitors in a cell culture reporter assay to identify functional regulators of CLK/CYC‐dependent gene expression. These studies and analysis of constitutively active forms of kinases revealed that cyclic nucleotide/protein kinase A (PKA), calcium/calmodulin‐dependent kinase (CaMK) II and Ras/mitogen‐activated protein kinase (MAPK) regulate CLK/CYC activity. In vitro phosphorylation analysis showed a direct phosphorylation of CLK by CaMK II and p42 MAPK [extracellular signal‐regulated kinase (ERK) 2], suggesting that these kinases regulate CLK/CYC‐dependent transcription by direct phosphorylation of CLK.
Slow and selective death of spinal motor neurons in vivo by intrathecal infusion of kainic acid: implications for AMPA receptor‐mediated excitotoxicity in ALS
Authors: Sun Hui , Kawahara Yukio , Ito Kyoko , Kanazawa Ichiro , Kwak Shin 
Published: May 2006

AbstractExcitotoxicity mediated by α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) receptors has been proposed to play a major role in the selective death of motor neurons in sporadic amyotrophic lateral sclerosis (ALS), and motor neurons are more vulnerable to AMPA receptor‐mediated excitotoxicity than are other neuronal subclasses. On the basis of the above evidence, we aimed to develop a rat model of ALS by the long‐term activation of AMPA receptors through continuous infusion of kainic acid (KA), an AMPA receptor agonist, into the spinal subarachnoid space. These rats displayed a progressive motor‐selective behavioral deficit with delayed loss of spinal motor neurons, mimicking the clinicopathological characteristics of ALS. These changes were significantly ameliorated by co‐infusion with 6‐nitro‐7‐sulfamobenso(f)quinoxaline‐2,3‐dione (NBQX), but not with d(–)‐2‐amino‐5‐phosphonovaleric acid (APV), and were exacerbated by co‐infusion with cyclothiazide, indicative of an AMPA receptor‐mediated mechanism. Among the four AMPA receptor subunits, expression of GluR3 mRNA was selectively up‐regulated in motor neurons but not in dorsal horn neurons of the KA‐infused rats. The up‐regulation of GluR3 mRNA in this model may cause a molecular change that induces the selective vulnerability of motor neurons to KA by increasing the proportion of GluR2‐lacking (i.e. calcium‐permeable) AMPA receptors. This rat model may be useful in investigating ALS etiology.
Going Native: Savage Actors and the Play of Textuality in Melville’s Benito Cereno
Authors: Ghorashi Mahni 
Published: May 2006

Abstract This essay won the 2005 Literature Compass Graduate Essay Prize, American Section. This essay on Herman Melville’s Benito Cereno (1856) examines the author’s views on savagery not merely as ethnic composition but as a progression through the performative to become a product of language itself. Thus, locating the savage becomes less a task of highlighting cultural otherness than examining how one writes and speaks about the primitive. In Benito Cereno, Melville liberates the discourse of civilized versus savage from what today would be considered a strictly post‐Colonial model – one which seems to fit Melville’s own encounters with the cultural outsider as documented in his early works Typee (1846), Omoo (1847), and Mardi (1849) – and places it in a linguistic sphere. Melville therefore introduces us to a savagery writ so large that only a system of signs becomes large enough to contain it. The critical figure in Benito Cereno is Babo, the mastermind behind a play of such monstrous proportions that even the reader becomes a savage actor in his infernal drama.
Understanding the genetics of autoimmune disease: two loci that regulate late onset Addison's disease in Portuguese Water Dogs
Authors: Chase K. , Sargan D. , Miller K. , Ostrander E. A. , Lark K. G. 
Published: May 2006

SummaryAddison's disease, an immune‐mediated disorder caused by destruction of the adrenal glands, is a rare disorder of Western European populations. Studies indicate that the disorder is polygenic in nature, involving specific alleles of the CTLA‐4, DRB1*04 and DQ, Cyp27B1, VDR and MIC‐A and ‐B loci. A similar immune form of Addison's disease occurs in several breeds of domestic dog, with frequencies ranging from 1.5 to 9.0%. The high frequency of the disease in domestic dog breeds likely reflects the small number of founders associated with many breeds, subsequent inbreeding, and the frequent use of popular sires.The Portuguese Water Dog (PWD) is a significantly affected breed. An analysis of 11 384 PWDs surveyed between 1985 and 1996 suggests a breed‐specific disease incidence of 1.5%. As with humans, the disease is typically of late onset.This study involves a genetic comparison of Addison's disease in the PWD to the analogous disease in humans. The study is facilitated by the existence of complete pedigrees and a relatively high degree of inbreeding among PWDs. The breed originated from 31 founders, with 10 animals responsible for 90% of the current gene pool. We describe, specifically, the identification of two disease‐associated loci, on Canis familiaris (CFA) chromosomes CFA12 and 37, which are syntenic with the human DRB1 histocompatibility locus alleles HLA‐DRB1*04 and DRB1*0301, and to a locus for immunosuppression syntenic with CTLA‐4. Strong similarities exist therefore in the complex genetic background of Addison's disease in humans and in the PWD. With the completion of the canine and human genome sequence, the purebred dog is set to become an important comparative model for Addison's as well as other human immune disorders.
HLA class II gene polymorphism in Parsees and Zoroastrians of Iran
Authors: Farjadian S. , Moqadam F. A. , Ghaderi A. 
Published: May 2006

SummaryExtensive polymorphism of the HLA genes in different ethnic groups has been used as an invaluable tool for anthropological studies. In this study, HLA‐DRB1, DQA1 and DQB1 allele frequencies and haplotypes were determined in 72 Parsees and 65 Zoroastrians living in Iran. The predominant DRB1 allele was *1103 = 4 in Parsees and *0701 in Zoroastrians. DQA1*0501 was the most common alleles in both spopulations. The most frequent DQB1 allele was *0301 in Parsees and *0201 in Zoroastrians. DRB1*1103 = 4‐DQA1*0501‐DQB1*0301 and DRB1*0701‐DQA1*0201‐DQB1*0201 were the most prevalent haplotypes in Parsees and Zoroastrians, respectively. Significant deviation from Hardy–Weinberg equilibrium was observed in DQA1 and DQB1 loci of Zoroastrians. The former locus also departed from neutrality due to balancing selection. All pairs of the studied loci in this study showed significant linkage disequilibrium. Analysis of molecular variance indicated that the main variation was confined to individuals within the studied populations. Neighbour‐joining tree based on Nei's genetic distances according to DRB1 and DQB1 allele frequencies showed that Parsees and Zoroastrians of Iran were located in the same cluster of the phylogenetic tree. Furthermore, Zoroastrians of Iran and Pakistan are very close to each other. This study will serve as a reference for further anthropological studies when the HLA profile of all ethnic groups of Iran is investigated.
THIS ARTICLE HAS BEEN RETRACTED  Cytokine typing: SNP allele frequencies in the Iranian population
Authors: Bagheri M. , Abdi‐Rad I. , Omrani D. , Khalkhali H. R. 
Published: May 2006

SummarySingle nucleotide polymorphisms within the promoter or other regulatory sequences of cytokine genes were evaluated and compared between an Iranian population and populations of different ethnic/geographical background. In 40 healthy Iranian subjects, cytokine typing was performed by polymerase chain reaction–sequence‐specific primers assay. Allele frequencies were calculated and compared with those of other populations.
CTLA‐4 gene polymorphisms and natural soluble CTLA‐4 protein in psoriasis vulgaris
Authors: Łuszczek W. , Kubicka W. , Jasek M. , Baran E. , Cisło M. , Nockowski P. , Łuczywo‐Rudy M. , Wiśniewski A. , Nowak I. , Kuśnierczyk P. 
Published: May 2006

SummaryCTLA‐4 molecule is an important inhibitor of T‐lymphocyte activation. Several single nucleotide polymorphisms (SNPs) in the CTLA‐4 gene were found, and their associations with many human diseases were described. So far, however, such studies have not been performed in psoriasis vulgaris in Caucasoids. Therefore, we examined the distribution of three CTLA‐4 SNPs: −1147C/T, −318C/T and +49 A/G in 116 patients with psoriasis vulgaris and 123 healthy blood donors using the polymerase chain reaction–restriction fragment length polymorphism method. For all three SNPs, the frequencies of alleles, genotypes and three‐point haplotypes were very similar in patients and controls, suggesting no contribution of these genetic variants to psoriasis.
STILBENE GLYCOSIDES FROM THE ROOTS OF POLYGONUM MULTIFLORUM THUNB AND THEIR IN VITRO ANTIOXIDANT ACTIVITIES
Authors: LI‐SHUANG L.V. , GU XIAOHONG , HO CHI‐TANG , TANG JIAN 
Published: May 2006

ABSTRACTStilbene glycosides (SGs) were isolated from the ethanol extract of the roots of Polygonum multiflorum (PM) Thunb. Three samples were obtained: the crude extract, the fraction separated by macroporous resin and the pure crystal 2,3,5,4′‐tetrahydroxystilbene 2‐O‐β‐D‐glucopyranoside. The structure of the crystals was determined by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectrometry. The antioxidant activities of three samples containing SG were evaluated using different antioxidant tests, including free radical scavenging, superoxide anion scavenging, hydroxyl radical scavenging and the inhibition of lipid peroxide formation in organs (liver, heart and brain) of a rat in vitro. These various antioxidant activities were compared with those of resveratrol, which is structurally similar to SG of PM. The results indicated that all three samples showed antioxidant activities, with the pure SG being the most efficient one. The IC50 values for 2,3,5,4′‐tetrahydroxystilbene 2‐O‐β‐D‐glucopyranoside were 8.06, 2.75 and 0.57 µg/mL for 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) scavenging, hydroxyl radical scavenging and superoxide anion scavenging, respectively. The IC50 values for 2,3,5,4′‐tetrahydroxystilbene 2‐O‐β‐D‐glucopyranoside in inhibiting lipid peroxide formation in liver, heart and brain were 13.68, 16.34 and 17.62 µg/mL, respectively. It was shown that SG from PM has a better antioxidant potency than that of resveratrol.
EFFECTS OF CORN MEAL, VITAL WHEAT GLUTEN, HIGH AMYLOSE STARCH AND EXTRUSION PARAMETERS ON TECHNOLOGICAL PROPERTIES OF WHEAT‐BASED EXTRUDED BREADING
Authors: ACIOLI‐MOURA RICARDO , CHANG YOON KIL 
Published: May 2006

ABSTRACT A wheat‐based extruded breading was produced using a Brabender single‐screw laboratory scale extruder (model GNF 1014/2) and applied to chicken nuggets. Response surface methodology was applied to study and optimize the effects of formulation and extrusion parameters on pick up, texture, solid loss, oil absorption and adhesiveness of fried coated nuggets. An optimized extruded breading was produced at 160C, 27% moisture content, 15% vital wheat gluten, 8% high amylose starch and 30% corn meal. The product showed pick up of 29.87%, adhesiveness of 100%, texture of 166.1 g, oil absorption of 2.97% and solid losses of 0.0885 absolute. The product presented similar values of pick up and adhesiveness, better texture, lower oil absorption and higher solid loss during deep‐frying, compared with commercial breadings. Acceptance test showed that the product had better overall appearance and fairly similar texture, compared with the commercial ones.
Role of the Na+/H+ exchanger NHE1 in cell migration
Authors: Stock C. , Schwab A. 
Published: May 2006

AbstractCell migration plays a basic role in many physiological and pathophysiological processes such as embryogenesis, immune defence, wound healing or metastasis. The activity of the ubiquitously expressed NHE1 isoform of the plasma membrane Na+/H+ exchanger is one of the requirements for directed locomotion of migrating cells and also contributes to cell adhesion. The mechanisms by which NHE1 is involved in cell migration are multiple. NHE1 contributes to cell migration by affecting the cell volume, by regulating the intracellular pH and thereby the assembly and activity of cytoskeletal elements, by anchoring the cytoskeleton to the plasma membrane, by signalling, by regulating gene expression and by controlling cell adhesion. The present article gives a review of the different ways in which NHE1 is involved in and contributes to cell migration. These different mechanisms complement one another forming an intricate, integrative process.
Evidence for the role of cell stiffness in modulation of volume‐regulated anion channels
Authors: Byfield F. J. , Hoffman B. D. , Romanenko V. G. , Fang Y. , Crocker J. C. , Levitan I. 
Published: May 2006

AbstractAim:  To investigate the link between cell stiffness and volume‐regulated anion current (VRAC) in aortic endothelium.Method:  Bovine aortic endothelial cells (BAECs) were exposed to methyl‐β‐cyclodextrin (MβCD) to deplete cellular cholesterol and the changes in cellular stiffness were measured by micropipette aspiration. VRAC density was measured electrophysiologically in the same cell populations. Furthermore, to probe the effects of cholesterol depletion on the mechanics of ‘deep’ cytoskeleton, we employ a novel technique to analyse correlated motion of intracellular particles.Results:  We show that cholesterol depletion results in cellular stiffening and an upregulation of VRAC density. Replenishing cellular sterol pool with epicholesterol, a chiral analogue of cholesterol, abrogates both of these effects. This indicates that cholesterol sensitivity of both cell mechanics and VRAC are due to changes in the physical properties of the membrane rather than due to specific sterol–protein interactions. We also show that cholesterol depletion increases the stiffness of the ‘deep cytoskeleton’ and that disruption of actin filaments abolishes both cell stiffening and upregulation of VRAC due to cholesterol depletion. Furthermore, comparing BAECs to human aortic endothelial cells (HAECs), we show that BAECs that are inherently stiffer also develop larger VRACs.Conclusions:  Taken together, our observations suggest an increase in the cytoskeleton stiffness has a facilitatory effect on VRAC development. We suggest that stiffening of the cytoskeleton increases tension in the membrane–cytoskeleton layer and that in turn facilitates VRAC.