bluuebunny/crossref_metadata_2025 huggingface dataset:
The cellulosomes from Clostridium cellulolyticum
Authors: Fendri Imen , Tardif Chantal , Fierobe Henri‐Pierre , Lignon Sabrina , Valette Odile , Pagès Sandrine , Perret Stéphanie
Published: April 2009

Cellulosomes produced by Clostridium cellulolyticum grown on cellulose were purified and separated using anion‐exchange chromatography. SDS/PAGE analysis of six fractions showed variations in their cellulosomal protein composition. Hydrolytic activity on carboxymethyl cellulose, xylan, crystalline cellulose and hatched straw differed from one fraction to another. Fraction F1 showed a high level of activity on xylan, whereas fractions F5 and F6 were most active on crystalline cellulose and carboxymethyl cellulose, respectively. Several cellulosomal components specific to fractions F1, F5 and F6 were investigated using MS analysis. Several hemicellulases were identified, including three xylanases in F1, and several cellulases belonging to glycoside hydrolase families 9 and 5 and, a cystein protease inhibitor were identified in F5 and F6. Synergies were observed when two or three fractions were combined. A mixture containing fractions F1, F3 and F6 showed the most divergent cellulosomal composition, the most synergistic effects and the highest level of activity on straw (the most heterogeneous substrate tested). These findings show that on complex substrates such as straw, synergies occur between differently composed cellulosomes and the degradation efficiency of the cellulosomes is correlated with their enzyme diversity.
Properties of ecdysteroid receptors from diverse insect species in a heterologous cell culture system – a basis for screening novel insecticidal candidates
Authors: Beatty Joshua M. , Smagghe Guy , Ogura Takehiko , Nakagawa Yoshiaki , Spindler‐Barth Margarethe , Henrich Vincent C.
Published: April 2009

Insect development is driven by the action of ecdysteroids on morphogenetic processes. The classic ecdysteroid receptor is a protein heterodimer composed of two nuclear receptors, the ecdysone receptor (EcR) and Ultraspiracle (USP), the insect ortholog of retinoid X receptor. The functional properties of EcR and USP vary among insect species, and provide a basis for identifying novel and species‐specific insecticidal candidates that disrupt this receptor’s normal activity. A heterologous mammalian cell culture assay was used to assess the transcriptional activity of the heterodimeric ecdysteroid receptor from species representing two major insect orders: the fruit fly, Drosophila melanogaster (Diptera), and the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera). Several nonsteroidal agonists evoked a strong response with the L. decemlineata heterodimer that was consistent with biochemical and in vivo evidence, whereas the D. melanogaster receptor’s response was comparatively modest. Conversely, the phytoecdysteroid muristerone A was more potent with the D. melanogaster heterodimer. The additional presence of juvenile hormone III potentiated the inductive activity of muristerone A in the receptors from both species, but juvenile hormone III was unable to potentiate the inductive activity of the diacylhydrazine methoxyfenozide (RH2485) in the receptor of either species. The effects of USP on ecdysteroid‐regulated transcriptional activity also varied between the two species. When it was tested with D. melanogaster EcR isoforms, basal activity was lower and ligand‐dependent activity was higher with L. decemlineata USP than with D. melanogaster USP. Generally, the species‐based differences validate the use of the cell culture assay screen for novel agonists and potentiators as species‐targeted insecticidal candidates.
Associations Between Coerced Anal Sex and Psychopathology, Marital Distress and Non-Sexual Violence
Authors: Mohammadkhani Parvaneh , Khooshabi Katayoon S. , Forouzan Ameneh Setareh , Azadmehr Hedieh , Assari Shervin , Lankarani Maryam Moghani
Published: April 2009

Background

There is a dearth of scientific data on anal intercourse in heterosexual relationships. Likewise, anal sex within marital relationships has yet to be fully explored.

Objectives

Among a representative sample of married women in the Iranian capital, Tehran, we aimed to determine the association of self-reported coerced anal sex with: (i) self-reported coerced vaginal sex; (ii) self-reported non-sexual violence; (iii) psychopathology; and (iv) marital attitude.

Method

The data presented here were obtained from the Family Violence Survey conducted in Tehran in 2007. A total of 230 married Iranian women were selected via a multi-cluster sampling method from four different randomized regions. The subjects’ sociodemographic data, psychological distress (Symptom Check List; SCL-90-R), personality, and relationship characteristics (Personal and Relationships Profile), and marital attitude (Marital Attitude Survey) were gathered. In addition, the participants’ self-reported histories of lifetime victimization through all types of violence by the husband, including coerced anal and vaginal sex as well as psychological and physical assault (Conflict Tactic Scales-Revised; CTS-2), were collected.

Results

There were associations between self-reported victimization through coerced anal and vaginal sex (P < 0.001), psychological (P < 0.001), and physical aggression (P < 0.001). Those reporting to have been forced into anal intercourse cited higher rates of paranoid and psychotic features, jealousy, attribution of problems to one’s own behavior, conflict, and male dominance, as well as lower expectations of improvement in one’s marital relationship.

Conclusion

In marital relationships, women are at a higher risk of coerced anal sex if subjected to other types of sexual or non-sexual violence. Higher rates of psychopathology and poorer marital relationships are also allied to self-reported anal sexual coercion.
FK506 and Rapamycin Neuroprotect Erection and Involve Different Immunophilins in a Rat Model of Cavernous Nerve Injury
Authors: Lagoda Gwen , Sezen Sena F. , Burnett Arthur L.
Published: April 2009

Introduction

Immunophilin ligands function by binding to receptor proteins such as FK506 binding proteins (FKBPs). FKBPs are studied for their roles in neuroprotection.

Aim

Compare the effect of FK506 (FK) and rapamycin (RAP) on erectile function (EF) recovery and FKBP expressions in penis and major pelvic ganglion (MPG) after cavernous nerve (CN) injury.

Methods

Adult male rats were divided into four groups: sham surgery (CN exposure only) + vehicle; bilateral CN injury (BCNI; bilateral crush, 3 minutes with hemostat clamp) + vehicle; BCNI + FK (5 mg/kg/day, 5 days, sc); and BCNI + RAP (2 mg/kg/day, 5 days, sc). At both 24 hours (Day 1) or 1 week (Day 7) after BCNI, EF was assessed by intracavernosal pressure measurement and FKBPs 12, 38, 52, and 65 expressions were evaluated by Western blot analysis in collected penises and MPGs.

Main Outcome Measures

EF and change in protein expressions of FKBPs in the rat penis and MPG after BCNI with and without immunophilin ligand treatment.

Results

Both FK- and RAP-treated rats had preserved EF compared with vehicle-treated rats after BCNI. FKBPs changed variably following injury and treatment. In particular, in the penis at Day 1, FKBP 38 expression was decreased after BCNI and both FK and RAP attenuated this decrease. In MPG at Day 1, FKBP 38 expression was also decreased after BCNI and FK attenuated the decrease, while at Day 7, FKBP 38 expression was still decreased and RAP attenuated the decrease. Also, in the penis at Day 1, FKBP 65 expression decreased after BCNI and FK attenuated the decrease. In the MPG, FKBP 65 expression increased at both Days 1 and 7 with FK treatment.

Conclusions

Improved EF after BCNI, as shown with RAP, further suggests a role of immunophilin ligands as a protective therapy of CN injury associated erectile dysfunction. Our findings also suggest that select FKBPs, such as FKBP 38 and FKBP 65, may mediate these effects.
cDNA of an arylphorin‐type storage protein from Pieris rapae with parasitism inducible expression by the endoparasitoid wasp Pteromalus puparum
Authors: Zhu Jia‐Ying , Ye Gong‐Yin , Fang Qi , Hu Cui , Akhtar Zunnu‐raen
Published: April 2009

Abstract  This report presents the cDNA cloning of a storage protein, PraAry, from Pieris rapae and investigates its expression regulated by parasitism of an endoparasitoid wasp Pteromalus puparum. The full‐length cDNA of PraAry is 2 270 nucleotides and contains a 2 121 nucleotide open reading frame encoding 707 amino acids with calculated molecular weights of approximately 83 kDa. Analysis of the primary protein sequence revealed that it possesses a signal peptide of 16 amino acids at the N‐terminus and contains two highly conserved storage protein signature motifs. According to both phylogenetic analysis and the criteria for amino acid composition, PraAry belongs to the subfamily of arylphorin‐type storage protein (1.42% methionine and 18.82% aromatic amino acids). Reverse transcription – polymerase chain reaction analysis indicated that the transcriptional level of PraAry mRNA in P. rapae pupae fat body is inducible in response to parasitism by P. puparum.
Identification, isolation and characterization of the antifeedant constituent of Clausena anisata against Helicoverpa armigera (Lepidoptera: Noctuidae)
Authors: Pitan Olufemi O. R. , Ayelaagbe O. O. , Wang Hong‐Lei , Wang Chen‐Zhu
Published: April 2009

Abstract  Hexane, petroleum ether, chloroform, ethyl acetate, methanol and water extracts of Clausena anisata[(Willd.) Hook F. Ex Benth] leaves and roots were evaluated against Helicoverpa armigera (Hübner) for antifeedant activities. Antifeedant activity was confirmed, and was found to be higher in root extracts than those of the leaf. Chloroform and petroleum ether extracts of the root showed strongest antifeedant activities (DC50s [concentration (C) causing 50% deterrence compared with the control] 0.014% and 0.016% respectively), and root extracts were fractionated using silica gel column chromatography. One fraction of the chloroform and one of the petroleum ether root extracts was active; and on the basis of mass spectroscopy and 1H and 13C nuclear magnetic resonance spectral data, the active compounds in the two fractions were confirmed to be identical, and identified as osthol [2H‐1‐Benzopyran‐2‐one, 7‐methoxy‐8‐(3‐methyl‐2‐butenyl)]. The highest concentration of osthol was found in the chloroform root extract. Antifeedant activities of the root extracts, as measured by DC50 values, were highly correlated with their osthol contents. Approximately 99% of the variation in bioactivity of the root extracts could be accounted for by variation in osthol content; osthol therefore, appeared to be an antifeedant component of C. anisata to H. armigera. This may provide a new approach to managing this pest.
Multiple osteolytic bone lesions with high serum levels of interleukin‐6 and CCL chemokines in a patient with adult T cell leukemia
Authors: CHIBA K. , HASHINO S. , IZUMIYAMA K. , TOYOSHIMA N. , SUZUKI S. , KUROSAWA M. , ASAKA M.
Published: April 2009

A 37‐year‐old woman was diagnosed as having chronic adult T‐cell leukemia (ATL) of the skin by a skin biopsy and human T‐cell leukemia virus type‐1 serology at our hospital in August 1992. The skin lesions of ATL were improved by treatment with psoralen ultraviolet ray A. She complained of severe pain in her bilateral forearms, hands and ankles, and X‐ray examination in July 1999 revealed multiple punched‐out lesions of the extremities. Serum levels of parathyroid hormone‐related peptide, interleukin‐1β (IL‐1β), tumor necrosis factor‐α and total serum receptor activator of nuclear factor κB ligand were not elevated. However, serum levels of IL‐6, CCL2 monocyte chemoattractant protein‐1 (MCP‐1), CCL3 [macrophage inflammatory protein‐1α (MIP‐1α)] and CCL4 (MIP‐1β) were markedly elevated. Here, we have discussed the possible mechanism underlying the onset of the osteolytic lesions.
Consistent Regulation of Infrastructure Businesses: Some Economic Issues*
Authors: Menezes Flavio M.
Published: April 2009

This article examines some important economic issues associated with the notion that consistency in the regulation of infrastructure businesses is a desirable feature. It makes two important points. First, it is not easy to measure consistency. In particular, one cannot simply point to different regulatory parameters as evidence of inconsistent regulatory policy. Second, even if one does observe consistency emerging from decisions made by different regulators, it does not necessarily mean that this consistency is desirable. It might be the result, at least partially, of career concerns of regulators.
Protective effects of trichostatin A on liver injury in septic mice
Authors: Zhang Li , Wan Jingyuan , Jiang Rong , Wang Weiwei , Deng Huayu , Shen Yi , Zheng Weiping , Wang Yaping
Published: April 2009

Aim:  Acetylation is emerging as a crucial post‐translational modification in controlling the expression of eukaryotic genes. Histone deacetylase (HDAC) inhibitors, developed as antitumor reagents, have recently exhibited novel anti‐inflammatory properties. In the present study, the influence of HDAC inhibitor on hepatic injury during sepsis was investigated.

Methods:  Trichostatin A (TSA), a potent HDAC‐specific inhibitor, was administrated to mice with cecal ligation and puncture (CLP)‐induced sepsis. The degree of hepatic injury and inflammation was assessed subsequently.

Results:  The results indicated that TSA effectively protected liver from CLP‐induced injury as evidenced by decreased serum aminotransferases (alanine and aspartate) levels, reduced malondialdehyde (MDA) content in liver homogenates and improved histological damage. The dampened liver injury was accompanied by lower myeloperoxidase (MPO) activity and suppressed expression of intercellular adhesion molecule‐1 (ICAM‐1) in liver tissue. In addition, the concentrations of both interleukin (IL)‐6 and IL‐10 in serum or hepatic homogenates were also decreased in TSA‐treated septic mice.

Conclusion:  These data indicate that HDAC inhibitor TSA effectively attenuates liver injury during sepsis and these effects seem to rely on reduced inflammatory mediator production. These findings suggest that novel anti‐inflammatory drugs targeting HDAC might offer promising therapeutic intervention for controlling the dysregulated inflammation.
Blind Kriging: A New Method for Developing Metamodels
Authors: Joseph V. Roshan , Hung Ying , Sudjianto Agus
Published: April 2009

Kriging is a useful method for developing metamodels for product design optimization. The most popular kriging method, known as ordinary kriging, uses a constant mean in the model. In this article, a modified kriging method is proposed, which has an unknown mean model. Therefore, it is called blind kriging. The unknown mean model is identified from experimental data using a Bayesian variable selection technique. Many examples are presented, which show remarkable improvement in prediction using blind kriging over ordinary kriging. Moreover, a blind kriging predictor is easier to interpret and seems to be more robust against mis-specification in the correlation parameters.
Components, Building Blocks, and Demonstrations of Spherical Mechanisms in Microelectromechanical Systems
Authors: Lusk Craig P. , Howell Larry L.
Published: April 2009

Microelectromechanical systems (MEMS) are usually fabricated using planar processing methods, which complicates the design of devices capable of complex motions. For applications that need a micromechanism that rotates out of the plane of fabrication with an in-plane rotational input, or that rotates spatially about a point, spherical kinematics may represent an appropriate solution. This paper describes the design of spherical mechanisms for MEMS including the design of joints and links, and what may be the first demonstration of two spherical micromechanism building blocks: the spherical four-bar micromechanism and the spherical slider-crank micromechanism. Two other micromechanisms are demonstrated to illustrate how the building block devices may be used to create more complex devices.
Bowed Stators: An Example of CFD Applied to Improve Multistage Compressor Efficiency
Authors: Weingold H. D. , Neubert R. J. , Behlke R. F. , Potter G. E.
Published: April 2009

Analysis of multistage compressor stator surface static pressure data reveals that the radial growth of suction surface corner separation prematurely separates core flow stator sections, limiting their pressure rise capability and generating endwall loss. Modeling of the stator flowfield, using a three-dimensional Euler analysis, has led to the development of “bowed” stator shapes, which generate radial forces that reduce diffusion rates in the suction surface corners, in order to delay the onset of corner separation. Experimental testing of the bowed stator concept in a three-stage research compressor has confirmed the elimination of suction surface corner separation, the resulting reduction of the endwall loss, and the increase in pressure rise capability of the stator core sections. This results in more robust pressure rise characteristics and substantially improved efficiency over the entire flow range of the compressor. The strong interaction effects of the bowed stator with the viscous endwall flowfield are shown to be predictable using a three-dimensional multistage Navier–Stokes analysis. This permits matching of the rotors to the altered stator exit profiles, in order to avoid potential stability limiting interactions. Application of bowed stators to a high bypass ratio engine eleven-stage high-pressure compressor has resulted in substantial improvement in efficiency, with no stability penalty.
Unsteady Flow Field Due to Nozzle Wake Interaction With the Rotor in an Axial Flow Turbine: Part II—Rotor Exit Flow Field
Authors: Zaccaria M. A. , Lakshminarayana B.
Published: April 2009

The two-dimensional steady and unsteady flow field at midspan in a turbine rotor has been investigated experimentally using an LDV with an emphasis on the interaction of the nozzle wake with the rotor flow field. The velocity measurements are decomposed into a time-averaged velocity, a periodic velocity component, and an unresolved velocity component. The results in the rotor passage were presented in Part I. The flow field downstream of the rotor is presented in this paper. The rotor wake profiles and their decay characteristics were analyzed. Correlations are presented that match the decay of the various wake properties. The rotor wake velocity defect decays rapidly in the trailing edge region, becoming less rapid in the near and far wake regions. The rotor wake semi-wake width increases rapidly in the trailing edge region and then grows more gradually in the near and far wake regions. The decay of the maximum unresolved unsteadiness and maximum unresolved velocity cross correlations is very rapid in the trailing edge region and this trend slows in the far wake region. In the trailing edge region, the maximum periodic velocity correlations are much larger than the maximum unresolved velocity correlations. But the periodic velocity correlations decay much faster than the unresolved velocity correlations. The interactions of the nozzle and rotor wakes are also studied. While the interaction of the nozzle wake with the rotor wake does not influence the decay rate of the various wake properties, it does change the magnitude of the properties. These and other results are presented in this paper.
Targeted Killing of
Streptococcus mutans
by a Pheromone-Guided “Smart” Antimicrobial Peptide
Authors: Eckert Randal , He Jian , Yarbrough Daniel K. , Qi Fengxia , Anderson Maxwell H. , Shi Wenyuan
Published: April 2009

Within the repertoire of antibiotics available to a prescribing clinician, the majority affect a broad range of microorganisms, including the normal flora. The ecological disruption resulting from antibiotic treatment frequently results in secondary infections or other negative clinical consequences. To address this problem, our laboratory has recently developed a new class of pathogen-selective molecules, called
s
pecifically (or
s
electively)
t
argeted
a
nti
m
icrobial
p
eptides (STAMPs), based on the fusion of a species-specific targeting peptide domain with a wide-spectrum antimicrobial peptide domain. In the current study, we focused on achieving targeted killing of
Streptococcus mutans
, a cavity-causing bacterium that resides in a multispecies microbial community (dental plaque). In particular, we explored the possibility of utilizing a pheromone produced by
S. mutans
, namely, the
c
ompetence
s
timulating
p
eptide (CSP), as a STAMP targeting domain to mediate
S. mutans
-specific delivery of an antimicrobial peptide domain. We discovered that STAMPs constructed with peptides derived from CSP were potent against
S. mutans
grown in liquid or biofilm states but did not affect other oral streptococci tested. Further studies showed that an 8-amino-acid region within the CSP sequence is sufficient for targeted delivery of the antimicrobial peptide domain to
S. mutans
. The STAMPs presented here are capable of eliminating
S. mutans
from multispecies biofilms without affecting closely related noncariogenic oral streptococci, indicating the potential of these molecules to be developed into “probiotic” antibiotics which could selectively eliminate pathogens while preserving the protective benefits of a healthy normal flora.
Genetic-Biochemical Analysis and Distribution of the Ambler Class A β-Lactamase CME-2, Responsible for Extended-Spectrum Cephalosporin Resistance in
Chryseobacterium
(
Flavobacterium
)
meningosepticum
Authors: Bellais Samuel , Poirel Laurent , Naas Thierry , Girlich Delphine , Nordmann Patrice
Published: April 2009

In vitro synergy between extended-spectrum cephalosporins and either clavulanic acid or cefoxitin was found for
Chryseobacterium meningosepticum
isolates during a double-disk assay on an agar plate. An extended-spectrum β-lactamase (ESBL) gene from a
C. meningosepticum
clinical isolate was cloned and expressed in
Escherichia coli
DH10B. Its protein conferred resistance to most β-lactams including extended-spectrum cephalosporins but not to cephamycins or to imipenem. Its activity was strongly inhibited by clavulanic acid, sulbactam, and tazobactam, as well as by cephamycins and imipenem. Sequence analysis of the cloned DNA fragment revealed an open reading frame (ORF) of 891 bp with a G+C content of 33.9%, which lies close to the expected range of G+C contents of members of the
Chryseobacterium
genus. The ORF encoded a precursor protein of 297 amino acids, giving a mature protein with a molecular mass of 31 kDa and a pI value of 9.2 in
E. coli
. This gene was very likely chromosomally located. Amino acid sequence comparison showed that this β-lactamase, named CME-2 (
C. meningosepticum
ESBL), is a novel ESBL of the Ambler class A group (Bush functional group 2be), being weakly related to other class A β-lactamases. It shares only 39 and 35% identities with the ESBLs VEB-1 from
E. coli
MG-1 and CBL-A from
Bacteroides uniformis
, respectively. The distribution of
bla
CME-2
among unrelated
C. meningosepticum
species isolates showed that
bla
CME-2
-like genes were found in the
C. meningosepticum
strains studied but were absent from strains of other
C. meningosepticum
-related species. Each
C. meningosepticum
strain produced at least two β-lactamases, with one of them being a noninducible serine ESBL with variable pIs ranging from 7.0 to 8.5.
Ineffectiveness of Topoisomerase Mutations in Mediating Clinically Significant Fluoroquinolone Resistance in
Escherichia coli
in the Absence of the AcrAB Efflux Pump
Authors: Oethinger Margret , Kern Winfried V. , Jellen-Ritter Angelika S. , McMurry Laura M. , Levy Stuart B.
Published: April 2009

Fluoroquinolone-resistant mutants, selected from a wild-type
Escherichia coli
K-12 strain and its Mar mutant by exposure to increasing levels of ofloxacin on solid medium, were analyzed by Northern (RNA) blot analysis, sequencing, and radiolabelled ciprofloxacin accumulation studies. Mutations in the target gene
gyrA
(DNA gyrase), the regulatory gene
marR
, and additional, as yet unidentified genes (genes that probably affect efflux mediated by the multidrug efflux pump AcrAB) all contributed to fluoroquinolone resistance. Inactivation of the
acrAB
locus made all strains, including those with target gene mutations, hypersusceptible to fluoroquinolones and certain other unrelated drugs. These studies indicate that, in the absence of the AcrAB pump, gyrase mutations fail to produce clinically relevant levels of fluoroquinolone resistance.
Characterization of the Antiviral Effect of 2′,3′-Dideoxy-2′, 3′-Didehydro-β-l-5-Fluorocytidine in the Duck Hepatitis B Virus Infection Model
Authors: Le Guerhier Franck , Pichoud Christian , Guerret Sylviane , Chevallier Michèle , Jamard Catherine , Hantz Olivier , Li Xiu-Yan , Chen Shu-Hui , King Ivan , Trépo Christian , Cheng Yung-Chi , Zoulim Fabien
Published: April 2009

A novell-nucleoside analog of deoxycytidine, 2′,3′-dideoxy-2′,3′-didehydro-β-l-5-fluorocytidine (β-l-Fd4C), was recently shown to strongly inhibit hepatitis B virus (HBV) replication in the 2.2.15 cell line. Therefore, its antiviral activity was evaluated in the duck HBV (DHBV) infection model. Using a cell-free system for the expression of the DHBV polymerase, β-l-Fd4C-TP exhibited a concentration-dependent inhibition of dCTP incorporation into viral minus-strand DNA with a 50% inhibitory concentration of 0.2 μM which was lower than that of other tested deoxycytidine analogs, i.e., lamivudine-TP, ddC-TP, and β-l-FddC-TP. Further analysis showed that β-l-Fd4C-TP is likely to be a competitive inhibitor of dCTP incorporation and to cause premature DNA chain termination. In primary duck hepatocyte cultures infected in vitro, β-l-Fd4C administration exhibited a long-lasting inhibitory effect on viral DNA synthesis but could not clear viral covalently closed circular DNA (CCC DNA). Results of short-term antiviral treatment in experimentally infected ducklings showed that β-l-Fd4C exhibited the most potent antiviral effect, followed by β-l-FddC, lamivudine, and ddC. Longer administration of β-l-Fd4C induced a sustained suppression of viremia (>95% of controls) and of viral DNA synthesis within the liver. However, the persistence of trace amounts of viral CCC DNA detected only by PCR was associated with a recurrence of viral replication after drug withdrawal. In parallel, β-l-Fd4C treatment suppressed viral antigen expression within the liver and decreased intrahepatic inflammation and was not associated with any sign of toxicity. Our data, therefore, demonstrate that in the duck model of HBV infection, β-l-Fd4C is a potent inhibitor of DHBV reverse transcriptase activity in vitro and suppresses viral replication in the liver in vivo.
Comparison of the Effects of Liposomal Amphotericin B and Conventional Amphotericin B on Propafenone Metabolism and Hepatic Cytochrome P-450 in Rats
Authors: Inselmann G. , Volkmann A. , Heidemann H. T.
Published: April 2009

The effects of conventional amphotericin B (AmB) dissolved in sodium deoxycholate on microsomal cytochrome P-450 concentrations and propafenone metabolism to 5-hydroxy-propafenone and
N
-desalkyl-propafenone were compared with those of liposomal AMB (Li-AMB) in rats. AmB (3 mg/kg/day, intravenously [i.v.]) given for 4 days caused a significant decrease in the concentration of hepatic microsomal cytochrome P-450 (0.43 ± 0.06 nmol/mg versus 0.62 ± 0.05 nmol/mg for the control [
P
< 0.05]). Following the application of Li-AMB (15 mg/kg/day, i.v.), hepatic microsomal cytochrome P-450 concentrations were unchanged at 0.64 ± 0.08 nmol/mg. AmB decreased ex vivo propafenone metabolism to 5-hydroxy-propafenone and
N
-desalkyl-propafenone significantly. Sodium deoxycholate (the vehicle of AmB) by itself induced a significant decline of 5-hydroxy-propafenone and
N
-desalkyl-propafenone production, while microsomal cytochrome P-450 concentrations remained unchanged. In contrast, Li-AMB did not change the levels of production of 5-hydroxy-propafenone or of
N
-desalkyl-propafenone at either substrate concentration tested (50 μmol and 200 μmol). Microsomal AmB concentrations were significantly higher following Li-AMB application (21.1 ± 6.2 μg/g versus 3.7 ± 1.4 μg/g for AmB [
P
< 0.05]). We conclude that Li-AMB, in contrast to AmB, decreases neither hepatic microsomal cytochrome P-450 nor hepatic propafenone metabolism in rats ex vivo. Sodium deoxycholate alone decreases propafenone metabolism in a similar way to AmB, suggesting that it participates in AmB-induced disturbance of hepatic metabolic function.
Effects of Atovaquone and Diospyrin-Based Drugs on Ubiquinone Biosynthesis in
Pneumocystis carinii
Organisms
Authors: Kaneshiro Edna S. , Sul Donggeun , Hazra Banasri
Published: April 2009

The naphthoquinone atovaquone is effective against
Plasmodium
and
Pneumocystis carinii carinii
. In
Plasmodium
, the primary mechanism of drug action is an irreversible binding to the mitochondrial cytochrome
bc
1
complex as an analog of ubiquinone. Blockage of the electron transport chain ultimately inhibits de novo pyrimidine biosynthesis since dihydroorotate dehydrogenase, a key enzyme in pyrimidine biosynthesis, is unable to transfer electrons to ubiquinone. In the present study, the effect of atovaquone was examined on
Pneumocystis carinii carinii
coenzyme Q biosynthesis (rather than electron transport and respiration) by measuring its effect on the incorporation of radiolabeled
p
-hydroxybenzoate into ubiquinone in vitro. A triphasic dose-response was observed, with inhibition at 10 nM and then stimulation up to 0.2 μM, followed by inhibition at 1 μM. Since other naphthoquinone drugs may also act as analogs of ubiquinone, diospyrin and two of its derivatives were also tested for their effects on ubiquinone biosynthesis in
P. carinii carinii
. In contrast to atovaquone, these drugs did not inhibit the incorporation of
p
-hydroxybenzoate into
P. carinii carinii
ubiquinone.
Postantibiotic Effects of Grepafloxacin Compared to Those of Five Other Agents against 12 Gram-Positive and -Negative Bacteria
Authors: Spangler Sheila K. , Bajaksouzian Saralee , Jacobs Michael R. , Appelbaum Peter C.
Published: April 2009

The postantibiotic effect (PAE) (10× the MIC) and the postantibiotic sub-MIC effects (0.125, 0.25, and 0.5× the MIC) were determined for six compounds against 12 strains. Measurable PAEs ranged between 0 and 1.8 h for grepafloxacin, 0 and 2.2 h for ciprofloxacin, 0 and 3.1 h for levofloxacin, 0 and 2.2 h for sparfloxacin, 0 and 2.4 h for amoxicillin-clavulanate and 0 and 4.8 h for clarithromycin. Reexposure to subinhibitory concentrations increased the PAEs against some strains.
Therapeutic Efficacy of Human Macrophage Colony-Stimulating Factor, Used Alone and in Combination with Antifungal Agents, in Mice with SystemicCandida albicansInfection
Authors: Kuhara Tetsuya , Uchida Katsuhisa , Yamaguchi Hideyo
Published: April 2009

We examined the in vivo activity of human macrophage colony-stimulating factor (hM-CSF) against lethalCandida albicansinfection in mice. InC. albicans-infected mice which had been immunosuppressed with cyclophosphamide, treatment with hM-CSF at a daily dose of 8 × 105units/kg of body weight or greater slightly but significantly prolonged survival. Furthermore, the therapeutic efficacy of amphotericin B (AMPH-B) in infected mice was enhanced by its combined use with hM-CSF, while that of fluconazole (FLCZ) was not. The activities of peritoneal macrophages and neutrophils from mice administered hM-CSF plus AMPH-B in combination for inhibition of hyphal growth ofC. albicanscells and intracellular phagocytosis and killing of the cells were greater than those of comparable phagocytic cells from control mice to which hM-CSF plus AMPH-B was not administered. These results suggest that intravenous administration of hM-CSF augments the efficacy of AMPH-B by enhancing the antifungal activities of macrophages and neutrophils. Therefore, it is expected that therapy with the combination AMPH-B and hM-CSF could improve the efficacy of AMPH-B and reduce the therapeutic dose of the antifungal drug that is required.
satG
, Conferring Resistance to Streptogramin A, Is Widely Distributed in
Enterococcus faecium
Strains but Not in Staphylococci
Authors: Haroche Julien , Allignet Jeanine , Aubert Sylvie , Van Den Bogaard Anthony E. , El Solh Névine
Published: April 2009

A gene almost identical to
satG
was isolated from an
Enterococcus faecium
strain. This gene was transferred to a
Staphylococcus aureus
recipient strain where it conferred resistance to streptogramin A.
satG
was found to be widely distributed among
E. faecium
strains but not detected among staphylococci.
Sequence Analysis of ARI-1, a Novel OXA β-Lactamase, Responsible for Imipenem Resistance in
Acinetobacter baumannii
6B92
Authors: Donald Helen M. , Scaife Wendy , Amyes Sebastian G. B. , Young Hilary-Kay
Published: April 2009

The sequence of the
bla
ARI-1
gene from imipenem-resistant
Acinetobacter baumannii
6B92 has been determined. The structural gene encodes a 273-amino-acid protein which is most related to the OXA class D β-lactamases. The conserved S-T-F-K and K-T-G motifs were identified in the ARI-1 protein sequence, also named OXA-23, but significantly, a point mutation (Y→F) was identified in the Y-G-N conserved motif, also known to function in the active site.
Δ
12
-Prostaglandin J
2
Is a Potent Inhibitor of Influenza A Virus Replication
Authors: Pica Francesca , Palamara Anna Teresa , Rossi Antonio , De Marco Alessandra , Amici Carla , Santoro M. Gabriella
Published: April 2009

9-Deoxy-Δ
9
,Δ
12
-13,14-dihydro-prostaglandin D
2
(Δ
12
-PGJ
2
), a natural cyclopentenone metabolite of prostaglandin D
2
, is shown to possess therapeutic efficacy against influenza A virus A/PR8/34 (H1N1) infection in vitro and in vivo. The results indicate that the antiviral activity is associated with induction of cytoprotective heat shock proteins and suggest novel strategies for treatment of influenza virus infection.
Bioavailability of Aciclovir after Oral Administration of Aciclovir and Its Prodrug Valaciclovir to Patients with Leukopenia after Chemotherapy
Authors: Steingrimsdottir Hlif , Gruber Astrid , Palm Carina , Grimfors Gunnar , Kalin Mats , Eksborg Staffan
Published: April 2009

The median bioavailabilities of aciclovir after administration of aciclovir and its prodrug valaciclovir were 21.5 and 70.1%, respectively, in 12 patients with malignant hematological diseases with leukopenia after chemotherapy. The interindividual variations of the bioavailability were 48.5 and 21.0% after administration of aciclovir and valaciclovir, respectively. Neither the bioavailability nor the interindividual variation of area under the concentration-time curve of oral aciclovir or valaciclovir differed from that reported in healthy volunteers.
Complete Sequence of a β-Lactamase-Encoding Plasmid in
Neisseria meningitidis
Authors: Bäckman Anders , Orvelid Paula , Vazquez Julio A. , Sköld Ola , Olcén Per
Published: April 2009

Identical β-lactamase-encoding (TEM-1) plasmids were found in two different clinical
Neisseria meningitidis
strains. They were completely sequenced (5,597 bp) and designated pAB6. The plasmid is almost identical to
Neisseria gonorrhoeae
plasmid pJD5 (5,599 kb) and may have been picked up from a gonococcus in vivo.
A Novel Integron in
Salmonella enterica
Serovar Enteritidis, Carrying the
bla
DHA-1
Gene and Its Regulator Gene
ampR
, Originated from
Morganella morganii
Authors: Verdet Charlotte , Arlet Guillaume , Barnaud Guilene , Lagrange Philippe H. , Philippon Alain
Published: April 2009

The genetic organization of the gene coding for DHA-1 and the corresponding
ampR
gene was determined by PCR mapping. These genes have been mobilized from the
Morganella morganii
chromosome and inserted into a complex
sulI
-type integron, similar to In6 and In7. However, they are not themselves mobile cassettes. This integron probably includes a specific site for recombination allowing the mobilization of diverse resistance genes, as observed for
bla
CMY-1
and
bla
MOX-1
.
Penetration of Rufloxacin into the Cerebrospinal Fluid in Patients with Inflamed and Uninflamed Meninges
Authors: Moretti Maria Vittoria , Pauluzzi Sergio , Cesana Marina
Published: April 2009

Forty-four patients scheduled for lumbar puncture (LP) were recruited to determine the level of penetration of orally administered rufloxacin into cerebrospinal fluid (CSF). The patients were divided into three clinical groups: those with normal CSF (groups A1dand A7d), those with aseptic meningitis (group B), and those with bacterial meningitis (group C). Members of group A1dreceived a single 400-mg rufloxacin dose, while group A7d, B, and C constituents had a multiple-dose regimen (one 400-mg dose, followed by one 200-mg dose daily for 6 days). LP was performed on group A1dmembers 5 h after they had received treatment, while for group A7dit was undertaken 5 h after administration of the last dose. For group B, LP was performed 5 h after the first and the last doses, whereas for group C it was undertaken after the first, fourth, and last doses. Concentrations of rufloxacin in simultaneously collected CSF and plasma samples were determined. Mean CSF/plasma rufloxacin concentration ratios ranged from 0.57 to 0.84, depending on the study group. A higher, but not statistically significant, degree of penetration into CSF was observed in patients with bacterial meningitis than in those with normal CSF or aseptic meningitis. These data indicate that rufloxacin diffuses efficiently into the CSF of patients with either inflamed or uninflamed meninges.
Removal of Nitrate from Groundwater by Cyanobacteria: Quantitative Assessment of Factors Influencing Nitrate Uptake
Authors: Hu Qiang , Westerhoff Paul , Vermaas Wim
Published: April 2009

The feasibility of biologically removing nitrate from groundwater was tested by using cyanobacterial cultures in batch mode under laboratory conditions. Results demonstrated that nitrate-contaminated groundwater, when supplemented with phosphate and some trace elements, can be used as growth medium supporting vigorous growth of several strains of cyanobacteria. As cyanobacteria grew, nitrate was removed from the water. Of three species tested,
Synechococcus
sp. strain PCC 7942 displayed the highest nitrate uptake rate, but all species showed rapid removal of nitrate from groundwater. The nitrate uptake rate increased proportionally with increasing light intensity up to 100 μmol of photons m
−2
s
−1
, which parallels photosynthetic activity. The nitrate uptake rate was affected by inoculum size (i.e., cell density), fixed-nitrogen level in the cells in the inoculum, and aeration rate, with vigorously aerated, nitrate-sufficient cells in mid-logarithmic phase having the highest long-term nitrate uptake rate. Average nitrate uptake rates up to 0.05 mM NO
3
−
h
−1
could be achieved at a culture optical density at 730 nm of 0.5 to 1.0 over a 2-day culture period. This result compares favorably with those reported for nitrate removal by other cyanobacteria and algae, and therefore effective nitrate removal from groundwater using this organism could be anticipated on large-scale operations.
Genetic Diversity of Clinical and Environmental Isolates of
Vibrio cholerae
Determined by Amplified Fragment Length Polymorphism Fingerprinting
Authors: Jiang Sunny C. , Matte Maria , Matte Glavur , Huq Anwar , Colwell Rita R.
Published: April 2009

Vibrio cholerae
, the causative agent of major epidemics of diarrheal disease in Bangladesh, South America, Southeastern Asia, and Africa, was isolated from clinical samples and from aquatic environments during and between epidemics over the past 20 years. To determine the evolutionary relationships and molecular diversity of these strains, in order to understand sources, origin, and epidemiology, a novel DNA fingerprinting technique, amplified fragment length polymorphism (AFLP), was employed. Two sets of restriction enzyme-primer combinations were tested for fingerprinting of
V. cholerae
serogroup O1, O139, and non-O1, O139 isolates. Amplification of
Hin
dIII- and
Taq
I-digested genomic DNA produced 30 to 50 bands for each strain. However, this combination, although capable of separating environmental isolates of O1 and non-O1 strains, was unable to distinguish between O1 and O139 clinical strains. This result confirmed that clinical O1 and O139 strains are genetically closely related. On the other hand, AFLP analyses of restriction enzyme
Apa
I- and
Taq
I-digested genomic DNA yielded 20 to 30 bands for each strain, but were able to separate O1 from O139 strains. Of the 74 strains examined with the latter combination, 26 serogroup O1 strains showed identical banding patterns and were represented by the O1 El Tor strain of the seventh pandemic. A second group, represented by O139 Bengal, included 12 strains of O139 clinical isolates, with 7 from Thailand, 3 from Bangladesh, and 2 from India. Interestingly, an O1 clinical isolate from Africa also grouped with the O139 clinical isolates. Eight clinical O1 isolates from Mexico grouped separately from the O1 El Tor of the seventh pandemic, suggesting an independent origin of these isolates. Identical fingerprints were observed between an O1 environmental isolate from a river in Chile and an O1 clinical strain from Kenya, both isolated more than 10 years apart. Both strains were distinct from the O1 seventh pandemic strain. Two O139 clinical isolates from Africa clustered with environmental non-O1 isolates, independent of other O139 strains included in the study. These results suggest that although a single clone of pathogenic
V. cholerae
appears responsible for many cases of cholera in Asia, Africa, and Latin America during the seventh pandemic, other cases of clinical cholera were caused by toxigenic
V. cholerae
strains that appear to have been derived locally from environmental O1 or non-O1 strains.
Oxygen Activation during Oxidation of Methoxyhydroquinones by Laccase from
Pleurotus eryngii
Authors: Guillén Francisco , Muñoz Carmen , Gómez-Toribio Víctor , Martínez Angel T. , Jesús Martínez María
Published: April 2009

Oxygen activation during oxidation of the lignin-derived hydroquinones 2-methoxy-1,4-benzohydroquinone (MBQH
2
) and 2,6-dimethoxy-1,4-benzohydroquinone (DBQH
2
) by laccase from
Pleurotus eryngii
was examined. Laccase oxidized DBQH
2
more efficiently than it oxidized MBQH
2
; both the affinity and maximal velocity of oxidation were higher for DBQH
2
than for MBQH
2
. Autoxidation of the semiquinones produced by laccase led to the activation of oxygen, producing superoxide anion radicals (Q
·−
+ O
2
↔ Q + O
2
·−
). As this reaction is reversible, its existence was first noted in studies of the effect of systems consuming and producing O
2
·−
on quinone formation rates. Then, the production of H
2
O
2
in laccase reactions, as a consequence of O
2
·−
dismutation, confirmed that semiquinones autoxidized. The highest H
2
O
2
levels were obtained with DBQH
2
, indicating that DBQ
·−
autoxidized to a greater extent than did MBQ
·−
. Besides undergoing autoxidation, semiquinones were found to be transformed into quinones via dismutation and laccase oxidation. Two ways of favoring semiquinone autoxidation over dismutation and laccase oxidation were increasing the rate of O
2
·−
consumption with superoxide dismutase (SOD) and recycling of quinones with diaphorase (a reductase catalyzing the divalent reduction of quinones). These two strategies made the laccase reaction conditions more natural, since O
2
·−
, besides undergoing dismutation, reacts with Mn
2+
, Fe
3+
, and aromatic radicals. In addition, quinones are continuously reduced by the mycelium of white-rot fungi. The presence of SOD in laccase reactions increased the extent of autoxidation of 100 μM concentrations of MBQ
·−
and DBQ
·−
from 4.5 to 30.6% and from 19.6 to 40.0%, respectively. With diaphorase, the extent of MBQ
·−
autoxidation rose to 13.8% and that of DBQ
·−
increased to 39.9%.
Artificial and Solar UV Radiation Induces Strand Breaks and Cyclobutane Pyrimidine Dimers in
Bacillus subtilis
Spore DNA
Authors: Slieman Tony A. , Nicholson Wayne L.
Published: April 2009

The loss of stratospheric ozone and the accompanying increase in solar UV flux have led to concerns regarding decreases in global microbial productivity. Central to understanding this process is determining the types and amounts of DNA damage in microbes caused by solar UV irradiation. While UV irradiation of dormant
Bacillus subtilis
endospores results mainly in formation of the “spore photoproduct” 5-thyminyl-5,6-dihydrothymine, genetic evidence indicates that an additional DNA photoproduct(s) may be formed in spores exposed to solar UV-B and UV-A radiation (Y. Xue and W. L. Nicholson, Appl. Environ. Microbiol. 62:2221–2227, 1996). We examined the occurrence of double-strand breaks, single-strand breaks, cyclobutane pyrimidine dimers, and apurinic-apyrimidinic sites in spore DNA under several UV irradiation conditions by using enzymatic probes and neutral or alkaline agarose gel electrophoresis. DNA from spores irradiated with artificial 254-nm UV-C radiation accumulated single-strand breaks, double-strand breaks, and cyclobutane pyrimidine dimers, while DNA from spores exposed to artificial UV-B radiation (wavelengths, 290 to 310 nm) accumulated only cyclobutane pyrimidine dimers. DNA from spores exposed to full-spectrum sunlight (UV-B and UV-A radiation) accumulated single-strand breaks, double-strand breaks, and cyclobutane pyrimidine dimers, whereas DNA from spores exposed to sunlight from which the UV-B component had been removed with a filter (“UV-A sunlight”) accumulated only single-strand breaks and double-strand breaks. Apurinic-apyrimidinic sites were not detected in spore DNA under any of the irradiation conditions used. Our data indicate that there is a complex spectrum of UV photoproducts in DNA of bacterial spores exposed to solar UV irradiation in the environment.
Natural Transformation of
Acinetobacter
sp. Strain BD413 with Cell Lysates of
Acinetobacter
sp.,
Pseudomonas fluorescens
, and
Burkholderia cepacia
in Soil Microcosms
Authors: Nielsen Kaare M. , Smalla Kornelia , van Elsas Jan D.
Published: April 2009

To elucidate the biological significance of dead bacterial cells in soil to the intra- and interspecies transfer of gene fragments by natural transformation, we have exposed the kanamycin-sensitive recipient
Acinetobacter
sp. strain BD413(pFG4) to lysates of the kanamycin-resistant donor bacteria
Acinetobacter
spp.,
Pseudomonas fluorescens
, and
Burkholderia cepacia
. Detection of gene transfer was facilitated by the recombinational repair of a partially (317 bp) deleted kanamycin resistance gene in the recipient bacterium. The investigation revealed a significant potential of these DNA sources to transform
Acinetobacter
spp. residing both in sterile and in nonsterile silt loam soil. Heat-treated (80°C, 15 min) cell lysates were capable of transforming strain BD413 after 4 days of incubation in sterile soil and for up to 8 h in nonsterile soil. Transformation efficiencies obtained in vitro and in situ with the various lysates were similar to or exceeded those obtained with conventionally purified DNA. The presence of cell debris did not inhibit transformation in soil, and the debris may protect DNA from rapid biological inactivation. Natural transformation thus provides
Acinetobacter
spp. with an efficient mechanism to access genetic information from different bacterial species in soil. The relatively short-term biological activity (e.g., transforming activity) of chromosomal DNA in soil contrasts the earlier reported long-term physical stability of DNA, where fractions have been found to persist for several weeks in soil. Thus, there seems to be a clear difference between the physical and the functional significance of chromosomal DNA in soil.