bluuebunny/crossref_metadata_2025_split huggingface dataset:
γ-Butyrolactone-Dependent Expression of theStreptomycesAntibiotic Regulatory Protein GenesrrYPlays a Central Role in the Regulatory Cascade Leading to Lankacidin and Lankamycin Production inStreptomyces rochei
Authors: Yamamoto Shouji , He Yuxi , Arakawa Kenji , Kinashi Haruyasu 
Published: December 2007

ABSTRACTOur previous studies revealed that thesrrXandsrrAgenes carried on the large linear plasmid pSLA2-L constitute a γ-butyrolactone-receptor system inStreptomyces rochei. Extensive transcriptional analysis has now showed that theStreptomycesantibiotic regulatory protein genesrrY, which is also carried on pSLA2-L, is a target of the receptor/repressor SrrA and plays a central role in lankacidin and lankamycin production. ThesrrYgene was expressed in a growth-dependent manner, slightly preceding antibiotic production. The expression ofsrrYwas undetectable in thesrrXmutant but was restored in thesrrX srrAdouble mutant. In addition, SrrA was bound specifically to the promoter region ofsrrY, and this binding was prevented by the addition of theS. rocheiγ-butyrolactone fraction, while the W119A mutant receptor SrrA was kept bound even in the presence ofS. rocheiγ-butyrolactone. Furthermore, the introduction of an intactsrrYgene under the control of a foreign promoter into thesrrXorsrrA(W119A) mutant restored antibiotic production. All of these results confirmed the signaling pathway fromsrrXthroughsrrAtosrrY, leading to lankacidin and lankamycin production.
A Mutational Analysis Defines
Vibrio fischeri
LuxR Binding Sites
Authors: Antunes Luis Caetano M. , Ferreira Rosana B. R. , Lostroh C. Phoebe , Greenberg E. Peter 
Published: December 2007

ABSTRACT

Vibrio fischeri
quorum sensing involves the LuxI and LuxR proteins. The LuxI protein generates the quorum-sensing signal
N
-3-oxohexanoyl-
l
-homoserine lactone (3OC6-HSL), and LuxR is a signal-responsive transcriptional regulator which activates the luminescence (
lux
) genes and 17 other
V. fischeri
genes. For activation of the
lux
genes, LuxR binds to a 20-base-pair inverted repeat, the
lux
box, which is centered 42.5 base pairs upstream of the transcriptional start of the
lux
operon. Similar
lux
box-like elements have been identified in only a few of the LuxR-activated
V. fischeri
promoters. To better understand the DNA sequence elements required for LuxR binding and to identify binding sites in LuxR-regulated promoters other than the
lux
operon promoter, we have systematically mutagenized the
lux
box and evaluated the activity of many mutants. By doing so, we have identified nucleotides that are critical for promoter activity. Interestingly, certain
lux
box mutations allow a 3OC6-HSL-independent LuxR activation of the
lux
operon promoter. We have used the results of the mutational analysis to create a consensus
lux
box, and we have used this consensus sequence to identify LuxR binding sites in 3OC6-HSL-activated genes for which
lux
boxes could not be identified previously.
The Acyl-Homoserine Lactone-Type Quorum-Sensing System Modulates Cell Motility and Virulence of
Erwinia chrysanthemi
pv. zeae
Authors: Hussain Mumtaz B. B. M. , Zhang Hai-Bao , Xu Jin-Ling , Liu Qiongguang , Jiang Zide , Zhang Lian-Hui 
Published: December 2007

ABSTRACT

Erwinia chrysanthemi
pv. zeae is one of the
Erwinia chrysanthemi
pathovars that infects on both dicotyledons and monocotyledons. However, little is known about the molecular basis and regulatory mechanisms of its virulence. By using a transposon mutagenesis approach, we cloned the genes coding for an
E. chrysanthemi
pv. zeae synthase of acyl-homoserine lactone (AHL) quorum-sensing signals (

expI
Ecz

) and a cognate response regulator (

expR
Ecz

). Chromatography analysis showed that

expI
Ecz

encoded production of the AHL signal
N
-(3-oxo-hexanoyl)-homoserine lactone (OHHL). Null mutation of

expI
Ecz

in the
E. chrysanthemi
pv. zeae strain EC1 abolished AHL production, increased bacterial swimming and swarming motility, disabled formation of multicell aggregates, and attenuated virulence of the pathogen on potato tubers. The mutation also marginally reduced the inhibitory activity of
E. chrysanthemi
pv. zeae on rice seed germination. The mutant phenotypes were rescued by either exogenous addition of AHL signal or in
trans
expression of

expI
Ecz

. These data demonstrate that the AHL-type QS signal plays an essential role in modulation of
E. chrysanthemi
pv. zeae cell motility and the ability to form multicell aggregates and is involved in regulation of bacterial virulence.
In Vivo Growth of
Pseudomonas aeruginosa
Strains PAO1 and PA14 and the Hypervirulent Strain LESB58 in a Rat Model of Chronic Lung Infection
Authors: Kukavica-Ibrulj Irena , Bragonzi Alessandra , Paroni Moira , Winstanley Craig , Sanschagrin François , O'Toole George A. , Levesque Roger C. 
Published: December 2007

ABSTRACT

Pseudomonas aeruginosa
chronic lung infections are the major cause of morbidity and mortality in cystic fibrosis (CF) patients. The
P. aeruginosa
strains PAO1 and PA14 were compared with the Liverpool epidemic strain LESB58 to assess in vivo growth, infection kinetics, and bacterial persistence and localization within tissues in a rat model of chronic lung infection. The three
P. aeruginosa
strains demonstrated similar growth curves in vivo but differences in tissue distribution. The LESB58 strain persisted in the bronchial lumen, while the PAO1 and PA14 strains were found localized in the alveolar regions and grew as macrocolonies after day 7 postinfection. Bacterial strains were compared for swimming and twitching motility and for the production of biofilm. The
P. aeruginosa
LESB58 strain produced more biofilm than PAO1 and PA14. Competitive index (CI) analysis of PAO1, PA14, and LESB58 in vivo indicated CI values of 0.002, 0.0002, and 0.14 between PAO1-PA14, PAO1-LESB58, and LESB58-PA14, respectively. CI analysis comparing the in vivo growth of the PAO1 ΔPA5441 mutant and four PA14 surface attachment-defective (
sad
) mutants gave CI values 10 to 1,000 times lower in competitions with their respective wild-type strains PAO1 and PA14.
P. aeruginosa
strains studied in the rat model of chronic lung infection demonstrated similar in vivo growth but differences in virulence as shown with a competitive in vivo assay. These differences were further confirmed with biofilm and motility in vitro assays, where strain LESB58 produced more biofilm but had less capacity for motility than PAO1 and PA14.
Coastal chalk cliff instability in NW France: role of lithology, fracture pattern and rainfall
Authors: Duperret A. , Genter A. , Martinez A. , Mortimore R. N. 
Published: December 2007

Abstract
Coastal retreat has been studied along 120km of French Channel chalk coast from Upper Normandy to Picardy. During the investigation period, 1998–2001, 55 significant collapses were recorded. Of these 5.5% were very large-scale, 34.5% large-scale, 34.5% medium-scale and 25.5% small-scale collapses. Observations indicate that the larger the collapse size the greater the coastal cliff retreat. Four types of cliff failure were observed: (1) vertical failures in homogeneous chalk units; (2) sliding failures where two superimposed chalk units were present; (3) wedge and plane failures mainly recognized in the UK in formations with stratabound fractures; (4) complex failures in cliffs with more than one style of fracturing. Rainfall in relation to the timing of cliff collapse indicates two periods that trigger a collapse. The first occurs about one month after heavy rainfall within poorly fractured chalk and the second occurs when a dry period is interrupted by sharp rainfall in cliffs with major karst features (pipes etc). Medium to small-scale cliff collapses were, in some cases, caused by marine erosion at the base of the cliff creating a notch. A key factor controlling the type of collapse is the lithostratigraphic unit, while the extent of the collapse scar may be controlled by fracture type.
Secondhand Smoke Exposure in Public Places in Guatemala: Comparison with other Latin American Countries
Authors: Barnoya Joaquin , Mendoza-Montano Carlos , Navas-Acien Ana 
Published: December 2007

Abstract
Objective: To measure secondhand smoke levels in workplaces in Guatemala and to compare exposure to levels in other Latin American cities.
Methods: Exposure was estimated by passive sampling of vapor phase nicotine using a filter badge. Filters were placed in 1 hospital, 1 school, 2 universities, 1 government building, the airport, and 10 restaurants/bars. In total, 103 filters were deployed (plus 7 duplicates and 10 blanks). Nicotine (μg/m3) was measured by gas chromatography. Medians [interquartile ranges (IQR)] of nicotine concentrations were reported and compared with other Latin American cities. A survey about attitudes for smoke-free workplaces was distributed among employees.
Results: Nicotine was detected in most (68%) locations surveyed (including workplaces where smoking is banned). The highest levels were found in bars [median, 4.58 μg/m3 (IQR, 1.71-6.44)] and restaurants [median, 0.56 μg/m3 (IQR, 0.46-0.71)]. Nicotine concentrations in bars and restaurants were 710 and 114 times higher, respectively, compared with hospital concentrations after adjustment for smoking ban signs, type of ventilation, and volume of the area. Support for smoke-free environments was high, except in bar/restaurant and airport workers. Airborne nicotine levels in Guatemala were similar to those found in other Latin American cities.
Conclusion: In Guatemala, exposure to secondhand smoke is highly prevalent. Workers in bars and restaurants are disproportionately exposed to secondhand smoke compared with other workers. There is an urgent need for complete smoke-free legislation and for educating workers about the benefits of smoke-free workplaces. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2730–5)
Distinctive Heavy Metal Composition of Pancreatic Juice in Patients with Pancreatic Carcinoma
Authors: Carrigan Patricia E. , Hentz Joseph G. , Gordon Gwyneth , Morgan Jennifer L. , Raimondo Massimo , Anbar Ariel D. , Miller Laurence J. 
Published: December 2007

Abstract
Epidemiologic studies have shown the health risks of exposure to cigarette smoke and air pollution, with heavy metal composition implicated as contributing to both. Environmental exposure to cigarette smoke has been epidemiologically associated with pancreatic cancer, but the pathophysiologic basis for this is not yet clear. In the current work, we have used inductively coupled plasma mass spectrometry to quantify the metal composition of pancreatic juice collected in response to secretin stimulation in successive patients evaluated for abdominal pain (35 with pancreatic cancer, 30 with chronic pancreatitis, and 35 with normal pancreas). Indeed, metal composition of pancreatic juice was distinctive in patients with pancreatic cancer relative to those without such a cancer. The metal concentrations that were found to have the strongest association with pancreatic cancer were chromium, selenium, and molybdenum, with 1 SD increases in the concentrations of each associated with substantial increases in the odds of having pancreatic cancer relative to those in patients with normal pancreas (210%, 160%, and 76%, respectively). Of note, elevations in concentrations of chromium and selenium did not correlate in individuals, whereas those having a 1 SD increase in the sum of the concentrations of these two metals in their pancreatic juice had a 480% increase in the odds of having pancreatic cancer. Elevations of nickel and zinc correlated with elevated chromium in individuals, with each of these metals known to be present in cigarette smoke, whereas other recognized metal components of cigarette smoke were not elevated. An understanding of why these metals are elevated in pancreatic juice and what effects they might have on pancreatic cells may have important implications for the diagnosis, treatment, and even prevention of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2656–63)
Time Trend and Geographic Patterns of Lung Adenocarcinoma in the United States, 1973-2002
Authors: Chen Fan , Cole Phillip , Bina William F. 
Published: December 2007

Abstract
Objective: To find the major factor explaining the substantial increase in incidence of adenocarcinoma of the lung (ADL), we observed its temporal trend, distributions in geographic areas and populations, and compared them with the distributions of air pollution and low-tar cigarette consumption in time, place, and populations.
Methods: The temporal and spatial patterns of ADL were compared with the level of nitrogen oxides (NOx) emissions as well as the use of low-tar cigarettes.
Results: Similar increasing trends followed by declining trends were seen in emission levels of NOx and ADL incidence rates. These trends peak about 20 years earlier for NOx levels than for ADL incidence. Incidence rates of ADL in high NOx emission areas were substantially higher than those in low NOx emission areas. Incidence rates of ADL in Black males are about 50% higher than in White males and can be explained by the differences in air quality related to residence site and size.
Conclusions: The descriptive epidemiologic data help generate the hypothesis that long-term exposure to low-dose NOx may play a major role in causing steep increases in past ADL incidence rates. There is an urgent need to conduct further studies to determine whether the association is a causal relationship between long-term, low-dose exposure to NOx and ADL. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2724–9)
Leptin Concentrations, Leptin Receptor Polymorphisms, and Colorectal Adenoma Risk
Authors: Chia Victoria M. , Newcomb Polly A. , Lampe Johanna W. , White Emily , Mandelson Margaret T. , McTiernan Anne , Potter John D. 
Published: December 2007

AbstractObesity has been shown to be associated with an increased risk of both colorectal cancer and adenomatous polyps. One mechanism underlying this relationship may involve the growth-promoting effects of the circulating hormones associated with obesity, such as leptin. We conducted a gastroenterology clinic-based, case-control study to evaluate the relationship between circulating leptin concentrations and colorectal adenoma risk; in addition, we evaluated the relationship between leptin receptor polymorphisms and adenoma risk. Individuals with adenomas (n = 157) and colonoscopy-negative controls (n = 191), who had a clinically indicated colonoscopy, were recruited from a large health maintenance organization in the Seattle metropolitan area from 1999 to 2003. Odds ratios and 95% confidence intervals were obtained using logistic regression, adjusting for age at diagnosis, body mass index, family history of colorectal cancer, smoking history, nonsteroidal anti-inflammatory drug use, physical activity, and, among women, menopausal status and postmenopausal hormone use. Among men, those in the highest tertile of leptin concentrations had a 3.3-fold (95% confidence interval, 1.2-8.7) increased adenoma risk compared with those in the lowest tertile (P trend = 0.01). There were no associations between leptin concentrations and adenoma risk in women. There were no associations of leptin receptor genotypes or haplotypes and adenoma risk. The results of this study suggest that, in men, leptin may be associated with risk of colorectal adenomas. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2697–703)
Cytokinesis-Block Micronucleus Cytome Assays for the Determination of Genotoxicity and Cytotoxicity of Cecal Water in Rats and Fecal Water in Humans
Authors: Benassi Bianca , LeLeu Richard , Bird Tony , Clifton Peter , Fenech Michael 
Published: December 2007

Abstract
We tested the cytokinesis-block micronucleus cytome assay using the WIL2-NS human B lymphoblastoid cell line as a biomarker of genotoxicity and cytotoxicity of cecal water from rats and fecal water from humans. Cecal water was assessed in rats fed either a diet rich in fat, low in calcium and fiber, and barbecued red meat as the protein source (high colorectal cancer risk diet) or a diet high in fiber and calcium, low in fat, and casein as the protein source (low colorectal cancer risk diet) for 2 weeks. There was a significant 7.6-, 1.8-, and 4.0-fold increase in binucleated (BN) cells with micronuclei (Mn-BN), BN cells with nucleoplasmic bridges (Npb-BN), and necrotic cells (P &lt; 0.001) with 1-h incubation with a 10% dilution of the cecal water isolated from rats fed the high colorectal cancer risk diet compared with rats fed the low colorectal cancer risk diet. In humans, fecal water samples collected from feces of free-living volunteers showed that 24-h exposure to 1% dilution of fecal water produced a significant 2.6-, 6.5-, 7.5-, and 2.2-fold increase in Mn-BN, Npb-BN, BN cells with nuclear buds, and necrotic cells compared with controls (P &lt; 0.05). The coefficients of variations for interindividual differences for Mn-BN, Npb-BN, BN cells with nuclear buds, and necrosis biomarkers were greater than corresponding coefficients of variations for intraindividual variation. These results indicate that the cytokinesis-block micronucleus cytome assay can be used successfully to determine the interindividual variation in genotoxicity and cytotoxicity of cecal or fecal water and to identify dietary patterns that are likely to increase carcinogenic events in the colon. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2676–80)
MDM2 Promoter Polymorphism SNP309 Contributes to Tumor Susceptibility: Evidence from 21 Case-Control Studies
Authors: Hu Zhibin , Jin Guangfu , Wang Lu , Chen Feng , Wang Xinru , Shen Hongbing 
Published: December 2007

Abstract
Since the identification of a well-characterized functional polymorphism named SNP309 in MDM2, abundant studies were published in the last 2 years to evaluate the association between SNP309 and tumor risk in diverse populations. However, the results remain conflicting rather than conclusive. Because a single study may have been underpowered to detect the effect of low-penetrance genes, a quantitative synthesis to accumulate data from different studies may provide better evidence on the association of genetic variant with tumor susceptibility. We conducted a meta-analysis on 14,770 cases with different tumor types and 14,524 controls from 25 published case-control studies to estimate the effect of SNP309 on tumor risk, as well as to quantify the potential between-study heterogeneity. We found that variant homozygote 309GG was associated with a significantly increased risk of all types of tumors [homozygote comparison: odds ratio (OR), 1.17, 95% confidential interval (95% CI), 1.04-1.33, P = 0.0002 for heterogeneity test; recessive model comparison: OR, 1.15, 95% CI, 1.03-1.28, P = 0.0005 for heterogeneity test]. Tumor type and ethnicity contributed to the substantial heterogeneity (69.5% for homozygote comparison and 77.2% for recessive model comparison). The analyses suggest that MDM2 SNP309 serves as a low-penetrance susceptibility tumor marker. Further large studies incorporate quantitative detection of different p53-responsible environmental stresses, p53 mutation status, and also functional genetic variants in p53-MDM2–related genes are warranted. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2717–23)
Medical Treatment in the Ottoman Navy in the Early Modern Period
Authors: Mossensohn Miri Shefer 
Published: December 2007

AbstractOttoman sources from the sixteenth and seventeenth centuries tell us a great deal about naval finances or dockyard operations. Indeed, the logistics of the Ottoman have been studied reasonably well. However, the Ottoman sources are virtually silent about the people involved in these naval operations. In this article the manpower will be in focus, with particular emphasis on the oarsmen who manned the galleys, the captives and criminals, and the medical treatment offered to them. The resulting discussion allows us to gain insights into the experiences of non-elite or behind the scenes Ottomans involved in the navy—whose voices are difficult to recover—toward the end of the seventeenth century. This article also indirectly contributes to the growing scholarship in recent years on Ottoman slavery. Les sources ottomanes du XVIème-XVIIème siècles sont très informatives au sujet des finances navales, autrement dit, les opérations du chantier naval. Pour cette raison le logiciel de la marine ottomane a été plutôt bien étudié. Par contre, les manuscrits ottomans adressent à peine la main-d'œuvre engagée dans les opérations navales. Cette contribution traite particulièremt des rameurs des galères, des captifs et des condamnés, ainsi que du traitement médical offert à eux. La discussion qui en résulte nous donne une idée des expériences du menu peuple ottoman servant dans la flotte et de ceux travaillant dans les coulisses – des personnes dont les archives nous parlent à peine – vers la fin du XVIIème siècle. En outre elle contribue de façon indirecte à l'étude de l'esclavage ottoman, un thème déployé depuis quelques ans.
Rhetorics of Power and Development: Intellectual Property Rights and The Pharmaceutical Industry in Brazil
Authors: McCabe Ariane 
Published: December 2007

AbstractThis paper examines the rise of an intellectual property (IP) rights discourse and highlights how it has been translated into national IP regimes. Recently, IP has become a polarizing concept, and attention has focused on questions that are overly narrow in scope. The characterization of the issue in simplistic dichotomous terms has ignored complex realities of developing countries. The case of Brazil is to highlights the complex ways in which the local pharmaceutical industry has been shaped by and has responded to the regulatory framework that has been established since and including the passage of the 1996 Industrial Property Law.
Marx's Critique of Economic Categories: Reflections on the Problem of Validity in the Dialectical Method of Presentation in Capital
Authors: Reichelt Helmut 
Published: December 2007

AbstractIt has often been pointed out that the Marxian theory of value contains some inconsistencies, usually in relation to the concept of abstract labour. However, the contradiction between the concept of labour and the concept of validity with which Marx operates in Capital (without actually explaining this conception) has never been discussed. A detailed analysis shows that this concept of validity refers to the process of abstraction which is carried out by the participants of the exchange process. Only the rigorous comprehension of this process of abstraction can illuminate that for which the concept of abstract labour was developed: the unity and universality of value. On this basis, the paper criticises the Marxian development of the money-form and presents an alternative approach that builds on the aforementioned concept of validity. This concept is formulated in more depth by recourse to the works of Hegel, Simmel and Adorno. Furthermore, the paper reconsiders the dialectical development of categories in the light of this alternative conception of the money-form as totality and abstraction (in the sense of Hegel and the young Marx). Finally, the distinction between simple circulation and the process as a whole (found only in the Grundrisse) is explored and it is argued that, according to the novel reading proposed, it acquires a fundamental significance.
Production vs. Realisation: A Critique of Fine and Saad-Filho on Value Theory
Authors: Kincaid Jim 
Published: December 2007

AbstractThis article assess two important recent books on Marx's political economy and argues that, despite many virtues, there are some crucial limitations in their approach to Marx's political economy. Ben Fine's and Alfredo Saad-Filho's Marx's 'Capital' and The Value of Marx by Saad-Filho place too much explanatory weight on the composition of capital, giving too little attention to Marx's analysis of money, and to the processes of circulation and realisation.