bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti-inflammatory effect of Rhus verniviflua Stokes by suppression of iNOS-mediated Akt and ERK pathways: in-vitro and in-vivo studies
Authors: Jung Chang Hwa , Kim Jeong-Hyun , Kim Ji Hye , Chung Joo Hee , Choi Han-Seok , Seo Jong Bok , Shin Yong-Cheol , Kim Sung-Hoon , Ko Seong-Gyu 
Published: March 2011

Abstract

Objectives
Rhus verniciflua Stokes (RVS), which has valuable medicinal properties, has for many years been prescribed for inflammation in east Asian medicine. Recent studies suggest that RVS has potent antioxidative, antitumor and anti-inflammatory properties.

Methods
In this study, the anti-inflammatory effects of RVS in vitro and in vivo were investigated. The ethanol extract from RVS was partitioned with different solvents in order of increasing polarity.

Key findings
Among the various extracts, the n-butanol extract displayed the most potent activity against nitric oxide and reactive oxygen species. The n-butanol extract also significantly regulates expression of nitric oxide synthase, which inhibits nitric oxide production at the transcriptional level in activated macrophages. Immunoblot analysis also showed that n-butanol extract suppresses the phosphorylation of extracellular signal-regulated kinase and Akt, suggesting that nitric oxide synthase suppression might be mediated via the extracellular signal-regulated kinase and Akt signaling pathways. This study also investigated whether n-butanol exerts an anti-inflammatory effect in an animal model. n-butanol extract significantly reduces carrageenan-induced mouse paw edema at 5 h.

Conclusions
These results suggest that RVS could be a promising candidate agent for inflammation prevention and combination therapy with anti-inflammatory drugs.
Oltipraz therapy in patients with liver fibrosis or cirrhosis: a randomized, double-blind, placebo-controlled phase II trial
Authors: Kim Sang Geon , Kim Young Mi , Choi Jong Young , Han Joon-Yeol , Jang Jeong Won , Cho Se-Hyun , Um Soon Ho , Chon Chae Yoon , Lee Dong Hoo , Jang Ja-June , Yu Eunsil , Lee Young Sok 
Published: March 2011

Abstract

Objectives
Oltipraz, a cancer chemopreventive agent, has an anticirrhotic effect in animals. A phase II trial was designed to investigate the preliminary efficacy of oltipraz therapy in liver fibrosis or cirrhosis.

Methods
Of 83 patients who were randomized to receive placebo, oltipraz 60 mg bid or oltipraz 90 mg qd for 24 weeks, 68 completed the study without any major protocol violation. Pre- and post-treatment liver biopsies, and blood fibrosis markers were assessed.

Key findings
Twenty-four weeks of oltipraz treatment showed no significant differences in the proportions of patients showing an improvement in histological outcomes, including Ishak fibrosis score. In the oltipraz 60 mg bid group, there was a trend of decreases in hepatic collagen area and plasma transforming growth factor-β1 (TGF-β1, a blood fibrosis marker) levels from baseline to week 24. In the per-protocol population (n = 68), decreases in plasma TGF-β1 correlated with those in the Ishak fibrosis score, suggesting that circulating TGF-β1 serves a possible indicator for fibrosis treatment.

Conclusions
No significant differences in liver histological outcomes were seen among the three treatment groups in this 24-week pilot study. Our finding indicates an association between TGF-β1 repression and improvement in the histological index of fibrosis.
A modified Tat peptide for selective intracellular delivery of macromolecules
Authors: Murphy Diarmaid J , Walker Brian , Greer Brett , Harriott Patrick , Martin S Lorraine 
Published: March 2011

Abstract

Objectives
The Tat peptide has been widely used for the intracellular delivery of macromolecules. The aim of this study was to modify the peptide to enable regulation of cellular uptake through a dependency on activation by proteases present in the local environment.

Methods
The native Tat peptide sequence was altered to inhibit the initial interaction of the peptide with the cell membrane through the addition of the consensus sequence for urokinase plasminogen activator (uPA). uPA expression was characterised and semi-quantitatively rated in three cell lines (U251mg, MDA-MB-231 and HeLa). The modified peptide was incubated with both recombinant enzyme and with cells varying in uPA activity. Cellular uptake of the modified Tat peptide line was compared with that of the native peptide and rated according to uPA activity measured in each cell line.

Key findings
uPA activity was observed to be high in U251mg and MDA-MB-231 and low in HeLa. In MDA-MB-231 and HeLa, uptake of the modified peptide correlated with the level of uPA expression detected (93 and 52%, respectively). In U251mg, however, the uptake of the modified peptide was much less (19% observed reduction) than the native peptide despite a high level of uPA activity detected.

Conclusions
Proteolytic activation represents an interesting strategy for the targeted delivery of macromolecules using peptide-based carriers and holds significant potential for further exploitation.
Vancomycin Dosing in Critically Ill Patients: Robust Methods for Improved Continuous-Infusion Regimens
Authors: Roberts Jason A. , Taccone Fabio Silvio , Udy Andrew A. , Vincent Jean-Louis , Jacobs Frédérique , Lipman Jeffrey 
Published: March 2011

ABSTRACT

Despite the development of novel antibiotics active against Gram-positive bacteria, vancomycin generally remains the first treatment, although rapidly achieving concentrations associated with maximal efficacy provides an unresolved challenge. The objective of this study was to conduct a population pharmacokinetic analysis of vancomycin in a large population of critically ill patients. This was a retrospective data collection of 206 adult septic critically ill patients who were administered vancomycin as a loading dose followed by continuous infusion. The concentration-versus-time data for vancomycin in serum was analyzed by a nonlinear mixed-effects modeling approach using NONMEM. Monte Carlo simulations were performed using the final covariate model. We found that the best population pharmacokinetic model consisted of a one-compartment linear model with combined proportional and additive residual unknown variability. The volume of distribution of vancomycin (1.5 liters/kg) was described by total body weight and clearance (4.6 liters/h) by 24-hour urinary creatinine clearance (CrCl), normalized to body surface area. Simulation data showed that a 35-mg/kg loading dose was necessary to rapidly achieve vancomycin concentrations of 20 mg/liter. Daily vancomycin requirements were dependent on CrCl, such that a patient with a CrCl of 100 ml/min/1.73 m
2
would require at least 35 mg/kg per day by continuous infusion to maintain target concentrations. In conclusion, we have found that higher-than-recommended loading and daily doses of vancomycin seem to be necessary to rapidly achieve therapeutic serum concentrations in these patients.
Are the Soft, Liquid-Like Structures Detected around Bacteria by Ambient Dynamic Atomic Force Microscopy Capsules?
Authors: Méndez-Vilas A. , Labajos-Broncano L. , Perera-Núñez J. , González-Martín M. L. 
Published: March 2011

ABSTRACT

High-resolution imaging of bacterial capsules by microscopy is of paramount importance in microbiology due to their role in pathogenesis. This is, however, quite a challenging task due to their delicate nature. In this context, recent reports have claimed successful exploitation of the capacity of atomic force microscopy (AFM) for imaging of extremely deformable (even liquid) surfaces under ambient conditions to detect bacterial capsules in the form of tiny amounts of liquid-like substances around bacteria. In order to further explore this supposed capacity of AFM, in this work, three staphylococcal strains have been scrutinized for the presence of capsules using such an AFM-based approach with a phosphate buffer and water as the suspending liquids. Similar results were obtained with the three strains. AFM showed the presence of liquid-like substances identical to those attributed to bacterial capsules in the previous literature. Extensive imaging and chemical analysis point out the central role of the suspending liquid (buffer) in the formation of these substances. The phenomenon has been reproduced even by using nonliving particles, a finding that refutes the biological origin of the liquid-like substances visualized around the cells. Deliquescence of major components of biological buffers, such as K
2
HPO
4
, CaCl
2
, or HEPES, is proposed as the fundamental mechanism of the formation of these ultrasmall liquid-like structures. Such an origin could explain the high similarity of our results obtained with three very different strains and also the high similarity of these results to others reported in the literature based on other bacteria and suspending liquids. Finally, possible biological/biomedical implications of the presence of these ultrasmall amounts of liquids wrapping microorganisms are discussed.
Moist-Heat Resistance, Spore Aging, and Superdormancy in Clostridium difficile
Authors: Rodriguez-Palacios Alexander , LeJeune Jeffrey T. 
Published: March 2011

ABSTRACT

Clostridium difficile
spores can survive extended heating at 71°C (160°F), a minimum temperature commonly recommended for adequate cooking of meats. To determine the extent to which higher temperatures would be more effective at killing
C. difficile
, we quantified (
D
values) the effect of moist heat at 85°C (145°F, for 0 to 30 min) on
C. difficile
spores and compared it to the effects at 71 and 63°C. Fresh (1-week-old) and aged (≥20-week-old)
C. difficile
spores from food and food animals were tested in multiple experiments. Heating at 85°C markedly reduced spore recovery in all experiments (5 to 6 log
10
within 15 min of heating;
P
< 0.001), regardless of spore age. In ground beef, the inhibitory effect of 85°C was also reproducible (
P
< 0.001), but heating at 96°C reduced 6 log
10
within 1 to 2 min. Mechanistically, optical density and enumeration experiments indicated that 85°C inhibits cell division but not germination, but the inhibitory effect was reversible in some spores. Heating at 63°C reduced counts for fresh spores (1 log
10
, 30 min;
P
< 0.04) but increased counts of 20-week-old spores by 30% (15 min;
P
< 0.02), indicating that sublethal heat treatment reactivates superdormant spores. Superdormancy is an increasingly recognized characteristic in
Bacillus
spp., and it is likely to occur in
C. difficile
as spores age. The potential for reactivation of (super)dormant spores with sublethal temperatures may be a food safety concern, but it also has potential diagnostic value. Ensuring that food is heated to >85°C would be a simple and important intervention to reduce the risk of inadvertent ingestion of
C. difficile
spores.
Versatile Enzyme Expression and Characterization System for Aspergillus nidulans, with the Penicillium brevicompactum Polyketide Synthase Gene from the Mycophenolic Acid Gene Cluster as a Test Case
Authors: Hansen Bjarne G. , Salomonsen Bo , Nielsen Morten T. , Nielsen Jakob B. , Hansen Niels B. , Nielsen Kristian F. , Regueira Torsten B. , Nielsen Jens , Patil Kiran R. , Mortensen Uffe H. 
Published: March 2011

ABSTRACT

Assigning functions to newly discovered genes constitutes one of the major challenges en route to fully exploiting the data becoming available from the genome sequencing initiatives. Heterologous expression in an appropriate host is central in functional genomics studies. In this context, filamentous fungi offer many advantages over bacterial and yeast systems. To facilitate the use of filamentous fungi in functional genomics, we present a versatile cloning system that allows a gene of interest to be expressed from a defined genomic location of
Aspergillus nidulans
. By a single USER cloning step, genes are easily inserted into a combined targeting-expression cassette ready for rapid integration and analysis. The system comprises a vector set that allows genes to be expressed either from the constitutive PgpdA promoter or from the inducible PalcA promoter. Moreover, by using the vector set, protein variants can easily be made and expressed from the same locus, which is mandatory for proper comparative analyses. Lastly, all individual elements of the vectors can easily be substituted for other similar elements, ensuring the flexibility of the system. We have demonstrated the potential of the system by transferring the 7,745-bp large
mpaC
gene from
Penicillium brevicompactum
to
A. nidulans
. In parallel, we produced defined mutant derivatives of
mpaC
, and the combined analysis of
A. nidulans
strains expressing
mpaC
or mutated
mpaC
genes unequivocally demonstrated that
mpaC
indeed encodes a polyketide synthase that produces the first intermediate in the production of the medically important immunosuppressant mycophenolic acid.
Solute Transport Proteins and the Outer Membrane Protein NmpC Contribute to Heat Resistance of Escherichia coli AW1.7
Authors: Ruan Lifang , Pleitner Aaron , Gänzle Michael G. , McMullen Lynn M. 
Published: March 2011

ABSTRACT

This study aimed to elucidate determinants of heat resistance in
Escherichia coli
by comparing the composition of membrane lipids, as well as gene expression, in heat-resistant
E. coli
AW1.7 and heat-sensitive
E. coli
GGG10 with or without heat shock. The survival of
E. coli
AW1.7 at late exponential phase was 100-fold higher than that of
E. coli
GGG10 after incubation at 60°C for 15 min. The cytoplasmic membrane of
E. coli
AW1.7 contained a higher proportion of saturated and cyclopropane fatty acids than that of
E. coli
GGG10. Microarray hybridization of cDNA libraries obtained from exponentially growing or heat-shocked cultures was performed to compare gene expression in these two strains. Expression of selected genes from different functional groups was quantified by quantitative PCR. DnaK and 30S and 50S ribosomal subunits were overexpressed in
E. coli
GGG10 relative to
E. coli
AW1.7 upon heat shock at 50°C, indicating improved ribosome stability. The outer membrane porin NmpC and several transport proteins were overexpressed in exponentially growing
E. coli
AW1.7. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of membrane properties confirmed that NmpC is present in the outer membrane of
E. coli
AW1.7 but not in that of
E. coli
GGG10. Expression of NmpC in
E. coli
GGG10 increased survival at 60°C 50- to 1,000-fold. In conclusion, the outer membrane porin NmpC contributes to heat resistance in
E. coli
AW1.7, but the heat resistance of this strain is dependent on additional factors, which likely include the composition of membrane lipids, as well as solute transport proteins.
Multiple DNA Extractions Coupled with Stable-Isotope Probing of Anthracene-Degrading Bacteria in Contaminated Soil
Authors: Jones Maiysha D. , Singleton David R. , Sun Wei , Aitken Michael D. 
Published: March 2011

ABSTRACTIn many of the DNA-based stable-isotope probing (SIP) studies published to date in which soil communities were investigated, a single DNA extraction was performed on the soil sample, usually using a commercial DNA extraction kit, prior to recovering the13C-labeled (heavy) DNA by density-gradient ultracentrifugation. Recent evidence suggests, however, that a single extraction of a soil sample may not lead to representative recovery of DNA from all of the organisms in the sample. To determine whether multiple DNA extractions would affect the DNA yield, the eubacterial 16S rRNA gene copy number, or the identification of anthracene-degrading bacteria, we performed seven successive DNA extractions on the same aliquot of contaminated soil either untreated or enriched with [U-13C]anthracene. Multiple extractions were necessary to maximize the DNA yield and 16S rRNA gene copy number from both untreated and anthracene-enriched soil samples. Sequences within the orderSphingomonadales, but unrelated to any previously described genus, dominated the 16S rRNA gene clone libraries derived from13C-enriched DNA and were designated “anthracene group 1.” Sequences clustering withVariovoraxspp., which were also highly represented, and sequences related to the genusPigmentiphagawere newly associated with anthracene degradation. The bacterial groups collectively identified across all seven extracts were all recovered in the first extract, although quantitative PCR analysis of SIP-identified groups revealed quantitative differences in extraction patterns. These results suggest that performing multiple DNA extractions on soil samples improves the extractable DNA yield and the number of quantifiable eubacterial 16S rRNA gene copies but have little qualitative effect on the identification of the bacterial groups associated with the degradation of a given carbon source by SIP.
Survival of Escherichia coli O157:H7 on Cattle Hides
Authors: Arthur Terrance M. , Nou Xiangwu , Kalchayanand Norasak , Bosilevac Joseph M. , Wheeler Tommy , Koohmaraie Mohammad 
Published: March 2011

ABSTRACT

The objective of this study was to determine the time period that
Escherichia coli
O157:H7 survives on the hides of cattle. Extensive research has been conducted and is ongoing to identify and develop novel preharvest intervention strategies to reduce the presence of
E. coli
O157:H7 on live cattle and subsequent transfer to processed carcasses. If a reduction of
E. coli
O157:H7 levels in feces can be achieved through preharvest intervention, it is not known how long it would take for such reductions to be seen on the hide. In the study presented herein, three trials were conducted to follow
E. coli
O157:H7 hide prevalence over time. For each trial, 36 animals were housed in individual stanchions to minimize or prevent hide contamination events. Through prevalence determination and isolate genotyping with pulsed-field gel electrophoresis, survival of
E. coli
O157:H7 on the hides of live cattle was determined to be short lived, with an approximate duration of 9 days or less. The results of this study suggest that any preharvest interventions that are to be administered at the end of the finishing period will achieve maximum effect in reducing
E. coli
O157:H7 levels on cattle hides if given 9 days before the cattle are presented for processing. However, it should be noted that interventions reducing pathogen shedding would also contribute to decreasing hide contamination through lowering the contamination load of the processing plant lairage environment, regardless of the time of application.
Intra- and Intergenerational Persistence of an Insect Nucleopolyhedrovirus: Adverse Effects of Sublethal Disease on Host Development, Reproduction, and Susceptibility to Superinfection
Authors: Cabodevilla Oihana , Villar Eduardo , Virto Cristina , Murillo Rosa , Williams Trevor , Caballero Primitivo 
Published: March 2011

ABSTRACT

Sublethal infections by
Spodoptera exigua
multiple nucleopolyhedrovirus (SeMNPV) are common in field populations of the beet armyworm (
S. exigua
, Hübner) in the Almerian horticultural region of Spain. Inoculation of second, third, and fourth instars with occlusion bodies (OBs) of an isolate (VT-SeAl1) associated with vertically transmitted infections resulted in 15 to 100% of sublethal infection in adult survivors, as determined by reverse transcription-PCR (RT-PCR) detection of viral DNA polymerase transcripts, and quantitative PCR (qPCR) targeted at the DNA polymerase gene. The prevalence of adult sublethal infection was positively related to the inoculum OB concentration consumed during the larval stage. Sublethal infections persisted in OB-treated insects for at least five generations. Viral transcripts were more frequently detected in adult insects than in third instars. qPCR analysis indicated a consistently higher prevalence of sublethal infection than RT-PCR. Sublethal infection was associated with significant reductions in pupal weight, adult emergence, fecundity, and fertility (egg hatch) and significant increases in larval development time and duration of the preoviposition period. Insects taken from a persistently infected experimental population were significantly more susceptible to the OB inoculum than control insects that originated from the same virus-free colony as the persistently infected insects. We conclude that OB treatment results in rapid establishment of sublethal infections that persist between generations and which incur costs in the development and reproductive capacity of the host insect.
Evaluation of Procedures for the Collection, Processing, and Analysis of Biomolecules from Low-Biomass Surfaces
Authors: Kwan K. , Cooper M. , La Duc M. T. , Vaishampayan P. , Stam C. , Benardini J. N. , Scalzi G. , Moissl-Eichinger C. , Venkateswaran K. 
Published: March 2011

ABSTRACT
To comprehensively assess microbial diversity and abundance via molecular-analysis-based methods, procedures for sample collection, processing, and analysis were evaluated in depth. A model microbial community (MMC) of known composition, representative of a typical low-biomass surface sample, was used to examine the effects of variables in sampling matrices, target cell density/molecule concentration, and cryogenic storage on the overall efficacy of the sampling regimen. The MMC used in this study comprised 11 distinct species of bacterial, archaeal, and fungal lineages associated with either spacecraft or clean-room surfaces. A known cellular density of MMC was deposited onto stainless steel coupons, and after drying, a variety of sampling devices were used to recover cells and biomolecules. The biomolecules and cells/spores recovered from each collection device were assessed by cultivable and microscopic enumeration, and quantitative and species-specific PCR assays. rRNA gene-based quantitative PCR analysis showed that cotton swabs were superior to nylon-flocked swabs for sampling of small surface areas, and for larger surfaces, biological sampling kits significantly outperformed polyester wipes. Species-specific PCR revealed differential recovery of certain species dependent upon the sampling device employed. The results of this study empower current and future molecular-analysis-based microbial sampling and processing methodologies.
Molecular Basis for Mycophenolic Acid Biosynthesis in Penicillium brevicompactum
Authors: Regueira Torsten Bak , Kildegaard Kanchana Rueksomtawin , Hansen Bjarne Gram , Mortensen Uffe H. , Hertweck Christian , Nielsen Jens 
Published: March 2011

ABSTRACT

Mycophenolic acid (MPA) is the active ingredient in the increasingly important immunosuppressive pharmaceuticals CellCept (Roche) and Myfortic (Novartis). Despite the long history of MPA, the molecular basis for its biosynthesis has remained enigmatic. Here we report the discovery of a polyketide synthase (PKS), MpaC, which we successfully characterized and identified as responsible for MPA production in
Penicillium brevicompactum. mpaC
resides in what most likely is a 25-kb gene cluster in the genome of
Penicillium brevicompactum
. The gene cluster was successfully localized by targeting putative resistance genes, in this case an additional copy of the gene encoding IMP dehydrogenase (IMPDH). We report the cloning, sequencing, and the functional characterization of the MPA biosynthesis gene cluster by deletion of the polyketide synthase gene
mpaC
of
P. brevicompactum
and bioinformatic analyses. As expected, the gene deletion completely abolished MPA production as well as production of several other metabolites derived from the MPA biosynthesis pathway of
P. brevicompactum
. Our work sets the stage for engineering the production of MPA and analogues through metabolic engineering.