bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iron chelator‐induced growth arrest and cytochrome c‐dependent apoptosis in immortalized and malignant oral keratinocytes
Authors: Lee Sun‐Kyung , Lee Jae‐Jung , Lee Hwa‐Jeong , Lee Jun , Jeon Byung‐Hun , Jun Chang‐Duk , Lee Suk‐Keun , Kim Eun‐Cheol 
Published: March 2006

Background:  Many studies have shown the anti‐proliferative effects of iron deprivation on cancer cells, but the effects of iron‐chelators on oral cancer have not been clearly elucidated.Methods:  To investigate the effects of an iron chelator, desferrioxamine (DFO), on the growth of immortalized human oral keratinocytes (IHOK), primary oral cancer cells (HN4), metastatic oral cancer cells (HN12) and human skin keratinocytes (HaCaT) in the MTT assay, three‐dimensional (3D) raft cultures, Western blotting, cell cycle analysis, nuclear staining and cytochrome c expression for apoptosis signaling pathway were used.Results:  Desferrioxamine inhibited the growth of immortalized IHOK and HaCaT and malignant HN4 and HN12 keratinocytes in a time‐ and dose‐dependent manner according to the MTT assay. The 3D organotypic culture also revealed that DFO‐treated cells showed less epithelial maturation, less surface keratinization and decreased epithelial thickness. The major mechanism of growth inhibition with the micromolar DFO treatment was by the induction of apoptosis, which was supported by nuclear DAPI staining, DNA fragmentation analysis and flow cytometric analysis for sub‐G1 phase arrest and Annexin V‐FITC (fluorescein isothiocyanate) staining. Furthermore, Bax expression increased together with p53 and p21WAF1/CIP1, while the Bcl‐2 expression decreased in the immortalized and malignant keratinocytes treated with DFO. Time‐dependent cytochrome c from mitochondria was observed in DFO‐treated IHOK and oral cancer cells and was accompanied by the activation of caspase‐3 in IHOK cells.Conclusion:  These results demonstrate that DFO has growth inhibitory effects on immortalized and malignant oral keratinocytes through the induction of apoptosis and suggest that further evaluation of DFO as a potential therapeutic agent for human oral precancerous lesions is warranted.
Renewing Kenneth Burke’s “Plea for the Shakespearean Drama”
Authors: Newstok Scott L. 
Published: March 2006

AbstractThis article surveys the criticism of the American writer Kenneth Burke (1897–1993), who composed several landmark essays on Shakespeare’s plays and poems throughout his lengthy career. His early writings examined the structures of scenes and the rhetorical appeals of characters, whereas his later pieces ambitiously articulated a ‘recipe’ for Shakespearean drama itself, in the spirit of Aristotle’sPoetics. Burke’s interpretations of Shakespeare anticipated many contemporary academic approaches, as he blended formalist, historical, materialist, psychoanalytic, and sociological critiques of literature. His interpretations continue to be influential, particularly in the United States (although his precedent is typically acknowledged through indirection). As a maverick intellectual, Burke remains difficult to place within the genealogy of literary criticism, as much for his stylistic voice as for ideological reasons.
A proposal for managing wastewater in Harare, Zimbabwe
Authors: Nhapi I. , Siebel M. A. , Gijzen H. J. 
Published: March 2006

AbstractThis paper deals with wastewater management in Harare, in the Lake Chivero catchment area of Zimbabwe. It aims at developing a sustainable system for managing water and nutrients and is based on the literature and a water quality monitoring study conducted from June 2000 to December 2001. This study has shown serious water pollution problems due to urbanisation in the catchment. A ‘three‐step strategic approach’ to urban (waste)water management was used as a basis for formulating solutions. The short‐term solutions include reduction of wastewater volume in industries and households, reducing wastewater flows by 24% and total phosphorus by 5%. The medium‐term solutions involve treating wastewater to high standards, resource recovery and reuse, and controlling upstream sources of pollution, and thus would reduce the lake total nitrogen and total phosphorus levels to about 0.4 and 0.07 mg/L, respectively. A long‐term solution was suggested based on pollution prevention and direct reuse, treatment at onsite and decentralised levels followed by reuse, and minimal disposal of the remaining effluents combined with the stimulation of the self‐purification capacity of the receiving rivers. It was concluded that it is feasible to reduce pollution levels in the catchment by applying these phased developments.
Art, Morality and Ethics: On the (Im)Moral Character of Art Works and Inter‐Relations to Artistic Value
Authors: Kieran Matthew 
Published: March 2006

AbstractThe (im)moral character of art works often affects how we respond to them. But should it affect our evaluation of them as art? The article surveys the contemporary debate whilst outlining further lines of argument and enquiry. The main arguments in favour of aestheticism, the claim that there is no internal relation between artistic value and moral character, are considered. Nonetheless the connection between art's instructional aspirations and artistic value, as well as the ways in which works solicit responses from us, underwrite the claim that a work's moral character can be directly relevant to a work's value as art. Various competing accounts of how the relationship goes, ethicism, moderate moralism and immoralism, are considered. The article goes on to elaborate novel considerations in favour of a suitably qualified cognitive immoralism and suggests avenues of further enquiry with respect to the moral character of art works.
Deposition of
Cryptosporidium
Oocysts in Streambeds
Authors: Searcy Kristin E. , Packman Aaron I. , Atwill Edward R. , Harter Thomas 
Published: March 2006

ABSTRACT

The transfer of
Cryptosporidium
oocysts from the surface water to the sediment beds of streams and rivers influences their migration in surface waters. We used controlled laboratory flume experiments to investigate the deposition of suspended
Cryptosporidium parvum
oocysts in streambeds. The experimental results demonstrate that hydrodynamic interactions between an overlying flow and a sediment bed cause oocysts to accumulate in the sediments and reduce their concentrations in the surface water. The association of
C. parvum
with other suspended sediments increased both the oocysts' effective settling velocity and the rate at which oocysts were transferred to the sediment bed. A model for the stream-subsurface exchange of colloidal particles, including physical transport and physicochemical interactions with sediment grains, accurately represented the deposition of both free
C. parvum
oocysts and oocysts that were attached to suspended sediments. We believe that these pathogen-sediment interactions play an important role in regulating the concentrations of
Cryptosporidium
in streams and rivers and should be taken into consideration when predicting the fate of pathogens in the environment.
Selective Removal of DNA from Dead Cells of Mixed Bacterial Communities by Use of Ethidium Monoazide
Authors: Nocker Andreas , Camper Anne K. 
Published: March 2006

ABSTRACT

The distinction between viable and dead bacterial cells poses a major challenge in microbial diagnostics. Due to the persistence of DNA in the environment after cells have lost viability, DNA-based quantification methods overestimate the number of viable cells in mixed populations or even lead to false-positive results in the absence of viable cells. On the other hand, RNA-based diagnostic methods, which circumvent this problem, are technically demanding and suffer from some drawbacks. A promising and easy-to-use alternative utilizing the DNA-intercalating dye ethidium monoazide bromide (EMA) was published recently. This chemical is known to penetrate only into “dead” cells with compromised cell membrane integrity. Subsequent photoinduced cross-linking was reported to inhibit PCR amplification of DNA from dead cells. We provide evidence here that in addition to inhibition of amplification, most of the DNA from dead cells is actually lost during the DNA extraction procedure, probably together with cell debris which goes into the pellet fraction. Exposure of bacteria to increasing stress and higher proportions of dead cells in defined populations led to increasing loss of genomic DNA. Experiments were performed using
Escherichia coli
O157:H7 and
Salmonella enterica
serovar Typhimurium as model pathogens and using real-time PCR for their quantification. Results showed that EMA treatment of mixed populations of these two species provides a valuable tool for selective removal of DNA of nonviable cells by using conventional extraction protocols. Furthermore, we provide evidence that prior to denaturing gradient gel electrophoresis, EMA treatment of a mature mixed-population drinking-water biofilm containing a substantial proportion of dead cells can result in community fingerprints dramatically different from those for an untreated biofilm. The interpretation of such fingerprints can have important implications in the field of microbial ecology.
A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials
Authors: Chambless Jason D. , Hunt Stephen M. , Stewart Philip S. 
Published: March 2006

ABSTRACT
Four hypothetical mechanisms for protection of biofilms against antimicrobials were incorporated into a three-dimensional model of biofilm growth and development. The model integrated processes of substrate utilization, diffusion, growth, cell migration, death, and detachment in a cellular automaton framework. Compared to simulations of unprotected biofilms, each of the protective mechanisms provided some tolerance to antimicrobial action. When the mechanisms were compared to each other, the behaviors of the four protective mechanisms produced distinct shapes of killing curves, nonuniform spatial patterns of survival and cell type distribution, and anticipated susceptibility patterns for dispersed biofilm cells. The differences between the protective mechanisms predicted in these simulations could guide the design of experiments to discriminate antimicrobial tolerance mechanisms in biofilms. Each of the mechanisms could be a plausible avenue of biofilm protection.
Non-Sulfate-Reducing, Syntrophic Bacteria Affiliated withDesulfotomaculumCluster I Are Widely Distributed in Methanogenic Environments
Authors: Imachi Hiroyuki , Sekiguchi Yuji , Kamagata Yoichi , Loy Alexander , Qiu Yan-Ling , Hugenholtz Philip , Kimura Nobutada , Wagner Michael , Ohashi Akiyoshi , Harada Hideki 
Published: March 2006

ABSTRACTThe classical perception of members of the gram-positiveDesulfotomaculumcluster I as sulfate-reducing bacteria was recently challenged by the isolation of new representatives lacking the ability for anaerobic sulfate respiration. For example, the two described syntrophic propionate-oxidizing species of the genusPelotomaculumform the novelDesulfotomaculumsubcluster Ih. In the present study, we applied a polyphasic approach by using cultivation-independent and culturing techniques in order to further characterize the occurrence, abundance, and physiological properties of subcluster Ih bacteria in low-sulfate, methanogenic environments. 16S rRNA (gene)-based cloning, quantitative fluorescence in situ hybridization, and real-time PCR analyses showed that the subcluster Ih population composed a considerable part of theDesulfotomaculumcluster I community in almost all samples examined. Additionally, five propionate-degrading syntrophic enrichments of subcluster Ih bacteria were successfully established, from one of which the new strain MGP was isolated in coculture with a hydrogenotrophic methanogen. None of the cultures analyzed, including previously describedPelotomaculumspecies and strain MGP, consumed sulfite, sulfate, or organosulfonates. In accordance with these phenotypic observations, a PCR-based screening fordsrAB(key genes of the sulfate respiration pathway encoding the alpha and beta subunits of the dissimilatory sulfite reductase) of all enrichments/(co)cultures was negative with one exception. Surprisingly, strain MGP containeddsrAB, which were transcribed in the presence and absence of sulfate. Based on these and previous findings, we hypothesize that members ofDesulfotomaculumsubcluster Ih have recently adopted a syntrophic lifestyle to thrive in low-sulfate, methanogenic environments and thus have lost their ancestral ability for dissimilatory sulfate/sulfite reduction.
Phylogenetic Analysis and In Situ Identification of
Bacteria
Community Composition in an Acidic
Sphagnum
Peat Bog
Authors: Dedysh Svetlana N. , Pankratov Timofei A. , Belova Svetlana E. , Kulichevskaya Irina S. , Liesack Werner 
Published: March 2006

ABSTRACT

The
Bacteria
community composition in an acidic
Sphagnum
peat bog (pH 3.9 to 4.5) was characterized by a combination of 16S rRNA gene clone library analysis, rRNA-targeted fluorescence in situ hybridization (FISH), and cultivation. Among 84 environmental 16S rRNA gene clones, a set of only 16 cloned sequences was closely related (≥95% similarity) to taxonomically described organisms. Main groups of clones were affiliated with the
Acidobacteria
(24 clones),
Alphaproteobacteria
(20),
Verrucomicrobia
(13),
Actinobacteria
(8),
Deltaproteobacteria
(4),
Chloroflexi
(3), and
Planctomycetes
(3). The proportion of cells that hybridized with oligonucleotide probes specific for members of the domains
Bacteria
(EUB338-mix) and
Archaea
(ARCH915 and ARC344) accounted for only 12 to 22% of the total cell counts. Up to 24% of the EUB338-positive cells could be assigned by FISH to specific bacterial phyla.
Alphaproteobacteria
and
Planctomycetes
were the most numerous bacterial groups (up to 1.3 × 10
7
and 1.1 × 10
7
cells g
−1
peat, respectively). In contrast to conventional plating techniques, a novel biofilm-mediated enrichment approach allowed us to isolate some representatives of predominant
Bacteria
groups, such as
Acidobacteria
and
Planctomycetes
. This novel strategy has great potential to enable the isolation of a significant proportion of the peat bog bacterial diversity.
Kinetics of Single Cells: Observation and Modeling of a Stochastic Process
Authors: Pin Carmen , Baranyi József 
Published: March 2006

ABSTRACT

The successive generation times for single cells of
Escherichia coli
K-12 were measured as described by A. Elfwing, Y. LeMarc, J. Baranyi, and A. Ballagi (Appl. Environ. Microbiol. 70:675-678, 2004), and the histograms they generated were used as empirical distributions to simulate growth of the population as the result of the multiplication of its single cells. This way, a stochastic birth model in which the underlying distributions were measured experimentally was simulated. To validate the model, analogous bacterial growth curves were generated by the use of different inoculum levels. The agreement with the simulation was very good, proving that the growth of the population can be predicted accurately if the distribution of the first few division times for the single cells within that population is known. Two questions were investigated by the simulation. (i) To what extent can we say that the distribution of the detection time, i.e., the time by which a single-cell-generated subpopulation reaches a detectable level, can be identified with that of the lag time of the original single cell? (ii) For low inocula, how does the inoculum size affect the lag time of the population?
Assessing the Impact of Denitrifier-Produced Nitric Oxide on Other Bacteria
Authors: Choi Peter S. , Naal Zeki , Moore Charles , Casado-Rivera Emerilis , Abruña Hector D. , Helmann John D. , Shapleigh James P. 
Published: March 2006

ABSTRACT

A series of experiments was undertaken to learn more about the impact on other bacteria of nitric oxide (NO) produced during denitrification. The denitrifier
Rhodobacter sphaeroides
2.4.3 was chosen as a denitrifier for these experiments. To learn more about NO production by this bacterium, NO levels during denitrification were measured by using differential mass spectrometry. This revealed that NO levels produced during nitrate respiration by this bacterium were in the low μM range. This concentration of NO is higher than that previously measured in denitrifiers, including
Achromobacter cycloclastes
and
Paracoccus denitrificans
. Therefore, both 2.4.3 and
A. cycloclastes
were used in this work to compare the effects of various NO levels on nondenitrifying bacteria. By use of bacterial overlays, it was found that the NO generated by
A. cycloclastes
and 2.4.3 cells during denitrification inhibited the growth of both
Bacillus subtilis
and
R. sphaeroide
s 2.4.1 but that
R. sphaeroides
2.4.3 caused larger zones of inhibition in the overlays than
A. cycloclastes
. Both
R. sphaeroides
2.4.3 and
A. cycloclastes
induced the expression of the NO stress response gene
hmp
in
B. subtilis
. Taken together, these results indicate that there is variability in the NO concentrations produced by denitrifiers, but, irrespective of the NO levels produced, microbes in the surrounding environment were responsive to the NO produced during denitrification.
Preferential Utilization of Aromatic Compounds over Glucose by
Pseudomonas putida
CSV86
Authors: Basu Aditya , Apte Shree K. , Phale Prashant S. 
Published: March 2006

ABSTRACT

Pseudomonas putida
CSV86, a naphthalene-degrading organism, exhibited diauxic growth on aromatic compounds plus glucose, with utilization of aromatics in the first log phase and of glucose in the second log phase. Glucose supplementation did not suppress the activity of degrading enzymes, which were induced upon addition of aromatic compounds. The induction was inhibited by chloramphenicol, suggesting that de novo protein synthesis was essential. Cells showed cometabolism of aromatic compounds and organic acids; however, organic acids suppressed glucose utilization.
Tolerance of
Listeria monocytogenes
to Cell Envelope-Acting Antimicrobial Agents Is Dependent on SigB
Authors: Begley Máire , Hill Colin , Ross R. Paul 
Published: March 2006

ABSTRACT

Mutation of
sigB
impairs the ability of
Listeria monocytogenes
to grow in sublethal levels, and to survive in lethal concentrations, of the bacteriocins nisin and lacticin 3147 and the antibiotics ampicillin and penicillin G. SigB may therefore represent an attractive target for the development of new control and treatment strategies for this important pathogen.
Synbiotic Microcapsules That Enhance Microbial Viability during Nonrefrigerated Storage and Gastrointestinal Transit
Authors: Crittenden Ross , Weerakkody Rangika , Sanguansri Luz , Augustin MaryAnn 
Published: March 2006

ABSTRACT

A
Bifidobacterium infantis
strain was microencapsulated within a film-forming protein-carbohydrate-oil emulsion. This novel encapsulant incorporated prebiotics and substantially protected the bacterium during nonrefrigerated storage and gastrointestinal transit. The dried microcapsules were small (15 to 20 μm), had low water activity (0.2 to 0.3), and rapidly released the bacteria in simulated intestinal fluid.
Analysis of 525 Samples To Determine the Usefulness of PCR Amplification and Sequencing of the 16S rRNA Gene for Diagnosis of Bone and Joint Infections
Authors: Fenollar Florence , Roux Véronique , Stein Andréas , Drancourt Michel , Raoult Didier 
Published: March 2006

ABSTRACT

The 16S rRNA gene PCR in the diagnosis of bone and joint infections has not been systematically tested. Five hundred twenty-five bone and joint samples collected from 525 patients were cultured and submitted to 16S rRNA gene PCR detection of bacteria in parallel. The amplicons with mixed sequences were also cloned. When discordant results were observed, culture and PCR were performed once again. Bacteria were detected in 139 of 525 samples. Culture and 16S rRNA gene PCR yielded identical documentation in 475 samples. Discrepancies were linked to 13 false-positive culture results, 5 false-positive PCR results, 9 false-negative PCR results, 16 false-negative culture results, and 7 mixed infections. Cloning and sequencing of 16S rRNA gene amplicons in 6 of 8 patients with mixed infections identified 2 to 8 bacteria per sample. Rarely described human pathogens such as
Alcaligenes faecalis
,
Comamonas terrigena
, and 21 anaerobes were characterized. We also detected, by 16S rRNA gene PCR, four previously identified bacteria never reported in human infection,
Alkanindiges illinoisensis
, dehydroabietic acid-degrading bacterium DhA-73, unidentified Hailaer soda lake bacterium, and uncultured bacterium clone HuCa4. Seven organisms representing new potential species were also detected. PCR followed by cloning and sequencing may help to identify new pathogens involved in mixed bone infection.
First Report of
Leishmania infantum
in French Guiana: Canine Visceral Leishmaniasis Imported from the Old World
Authors: Rotureau Brice , Ravel Christophe , Aznar Christine , Carme Bernard , Dedet Jean-Pierre 
Published: March 2006

ABSTRACT

The first two cases of canine visceral leishmaniasis in French Guiana are described. One infected dog was most probably imported from France. A second dog was then infected with
Leishmania infantum
in French Guiana. These observations exemplify the intercontinental transportation theory for
L. infantum
.
Isolation of a Strictly Anaerobic Strain of
Staphylococcus epidermidis
Authors: Rowlinson Marie-Claire , LeBourgeois Phyllis , Ward Kevin , Song Yuli , Finegold Sydney M. , Bruckner David A. 
Published: March 2006

ABSTRACT

Staphylococcus epidermidis
is a well-characterized, nonfastidious, aerobic gram-positive coccus commonly isolated in the clinical microbiology laboratory. Although coagulase-negative staphylococci, including
Staphylococcus epidermidis
, are often considered a contaminant in the clinical laboratory, an increasing number of reports describe their pathogenesis, in particular in infections of prosthetic devices. This article describes the isolation of a strictly anaerobic strain of
Staphylococcus epidermidis
in pure culture from the site of an infected prosthetic hip. This isolate was unique in that it grew only under strictly anaerobic conditions. Initially, the isolate was thought to be a known anaerobic gram-positive coccus. However, certain key biochemical and antimicrobial tests performed as part of the standard laboratory identification procedure were not consistent with results expected for any known anaerobic gram-positive coccus; the isolate was catalase positive and metronidazole and penicillin resistant. This isolate was characterized by further biochemical analysis, antimicrobial testing, and nucleic acid sequencing. This paper presents the first documented isolation of a strictly anaerobic
Staphylococcus epidermidis
strain, confirmed by
rpoB
gene sequencing.