bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic Di-GMP Stimulates Protective Innate Immunity in Bacterial Pneumonia
Authors: Karaolis David K. R. , Newstead Michael W. , Zeng Xianying , Hyodo Mamoru , Hayakawa Yoshihiro , Bhan Urvhashi , Liang Hallie , Standiford Theodore J. 
Published: July 2007

ABSTRACTInnate immunity is the primary mechanism by which extracellular bacterial pathogens are effectively cleared from the lung. We have previously shown that cyclic di-GMP (c-di-GMP [c-diguanylate]) is a novel small molecule immunomodulator and immunostimulatory agent that triggers protective host innate immune responses. Using a murine model of bacterial pneumonia, we show that local intranasal (i.n.) or systemic subcutaneous (s.c.) administration of c-di-GMP prior to intratracheal (i.t.) challenge withKlebsiella pneumoniaestimulates protective immunity against infection. Specifically, i.n. or s.c. administration of c-di-GMP 48 and 24 h prior to i.t.K. pneumoniaechallenge resulted in significantly increased survival. Pretreatment with c-di-GMP resulted in a 5-fold reduction in bacterial CFU in the lung (P< 0.05) and an impressive >1,000-fold decrease in CFU in the blood (P< 0.01). c-di-GMP administration stimulated a robust innate response to bacterial challenge, characterized by enhanced accumulation of neutrophils and αβ T cells, as well as activated NK and αβ T lymphocytes, which was associated with earlier and more vigorous expression of chemokines and type I cytokines. Moreover, lung macrophages recovered fromKlebsiella-infected mice pretreated with c-di-GMP expressed greater quantities of inducible nitric oxide synthase and nitric oxide ex vivo than did macrophages isolated from infected mice pretreated with the control, c-GMP. These findings demonstrate that c-di-GMP delivered in either a compartmentalized or systemic fashion stimulates protective innate immunity in the lung and protects mice against bacterial invasion. We propose that the cyclic dinucleotide c-di-GMP may be used clinically as an effective immunomodulator, immune enhancer, and vaccine adjuvant to protect against respiratory infection and pneumonia in humans and animals.
Topology of AspT, the Aspartate:Alanine Antiporter of
Tetragenococcus halophilus
, Determined by Site-Directed Fluorescence Labeling
Authors: Nanatani Kei , Fujiki Takashi , Kanou Kazuhiko , Takeda-Shitaka Mayuko , Umeyama Hideaki , Ye Liwen , Wang Xicheng , Nakajima Tasuku , Uchida Takafumi , Maloney Peter C. , Abe Keietsu 
Published: July 2007

ABSTRACT

The gram-positive lactic acid bacterium
Tetragenococcus halophilus
catalyzes the decarboxylation of
l
-aspartate (Asp) with release of
l
-alanine (Ala) and CO
2
. The decarboxylation reaction consists of two steps: electrogenic exchange of Asp for Ala catalyzed by an aspartate:alanine antiporter (AspT) and intracellular decarboxylation of the transported Asp catalyzed by an
l
-aspartate-β-decarboxylase (AspD). AspT belongs to the newly classified aspartate:alanine exchanger family (transporter classification no. 2.A.81) of transporters. In this study, we were interested in the relationship between the structure and function of AspT and thus analyzed the topology by means of the substituted-cysteine accessibility method using the impermeant, fluorescent, thiol-specific probe Oregon Green 488 maleimide (OGM) and the impermeant, nonfluorescent, thiol-specific probe [2-(trimethylammonium)ethyl]methanethiosulfonate bromide. We generated 23 single-cysteine variants from a six-histidine-tagged cysteineless AspT template. A cysteine position was assigned an external location if the corresponding single-cysteine variant reacted with OGM added to intact cells, and a position was assigned an internal location if OGM labeling required cell lysis. The topology analyses revealed that AspT has a unique topology; the protein has 10 transmembrane helices (TMs), a large hydrophilic cytoplasmic loop (about 180 amino acids) between TM5 and TM6, N and C termini that face the periplasm, and a positively charged residue (arginine 76) within TM3. Moreover, the three-dimensional structure constructed by means of the full automatic modeling system indicates that the large hydrophilic cytoplasmic loop of AspT possesses a TrkA_C domain and a TrkA_C-like domain and that the three-dimensional structures of these domains are similar to each other even though their amino acid sequences show low similarity.
A Novel Filamentous Phage from the Deep-Sea Bacterium
Shewanella piezotolerans
WP3 Is Induced at Low Temperature
Authors: Wang Feng , Wang Fengping , Li Qiang , Xiao Xiang 
Published: July 2007

ABSTRACT

Active filamentous phage particles were isolated from the deep-sea bacterium
Shewanella piezotolerans
WP3. A putative single-stranded DNA binding protein of the phage was found to be overexpressed at 4°C compared to its expression at 25°C by two-dimensional polyacrylamide gel electrophoresis. Reverse transcription quantitative PCR further revealed that the key genes of the SW1 phage were significantly induced at low temperature.
4-Sulfomuconolactone Hydrolases from
Hydrogenophaga intermedia
S1 and
Agrobacterium radiobacter
S2
Authors: Halak Sad , Basta Tamara , Bürger Sibylle , Contzen Matthias , Wray Victor , Pieper Dietmar Helmut , Stolz Andreas 
Published: July 2007

ABSTRACT

The 4-carboxymethylen-4-sulfo-but-2-en-olide (4-sulfomuconolactone) hydrolases from
Hydrogenophaga intermedia
strain S1 and
Agrobacterium radiobacter
strain S2 are part of a modified protocatechuate pathway responsible for the degradation of 4-sulfocatechol. In both strains, the hydrolase-encoding genes occur downstream of those encoding the enzymes that catalyze the lactonization of 3-sulfomuconate. The deduced amino acid sequences of the 4-sulfomuconolactone hydrolases demonstrated the highest degree of sequence identity to 2-pyrone-4,6-dicarboxylate hydrolases, which take part in the
meta
cleavage pathway of protocatechuate. The 4-sulfomuconolactone hydrolases did not convert 2-pyrone-4,6-dicarboxylate, and the 2-pyrone-4,6-dicarboxylate hydrolase from
Sphingomonas paucimobilis
SYK-6 did not convert 4-sulfomuconolactone. Nevertheless, the presence of highly conserved histidine residues in the 4-sulfomuconolactone and the 2-pyrone-4,6-dicarboxylate hydrolases and some further sequence similarities suggested that both enzymes belong to the metallo-dependent hydrolases (the “amidohydrolase superfamily”). The 4-sulfomuconolactone hydrolases were heterologously expressed as His-tagged enzyme variants. Gel filtration experiments suggested that the enzymes are present as monomers in solution, with molecular weights of approximately 33,000 to 35,000. 4-Sulfomuconolactone was converted by sulfomuconolactone hydrolases to stoichiometric amounts of maleylacetate and sulfite. The 4-sulfomuconolactone hydrolases from both strains showed pH optima at pH 7 to 7.5 and rather similar catalytic constant (
k
cat
/
K

M

)values. The suggested 4-sulfocatechol pathway from 4-sulfocatechol to maleylacetate was confirmed by in situ nuclear magnetic resonance analysis using the recombinantly expressed enzymes.
The EssentialtacFGene Is Responsible for the Choline-Dependent Growth Phenotype ofStreptococcus pneumoniae
Authors: Damjanovic Marlen , Kharat Arun S. , Eberhardt Alice , Tomasz Alexander , Vollmer Waldemar 
Published: July 2007

ABSTRACTStreptococcus pneumoniaehas an absolute nutritional requirement for choline, and the choline molecules are known to incorporate exclusively into the cell wall and membrane teichoic acids of the bacterium. We describe here the isolation of a mutant of strain R6 in which a single G→T point mutation in the genetacF(formerly designatedspr1150) is responsible for generating a choline-independent phenotype. The choline-independent phenotype could be transferred to the laboratory strain R6 and to the encapsulated strain D39 by genetic transformation with a PCR product or with a plasmid carrying the mutatedtacFgene. ThetacFgene product belongs to the protein family of polysaccharide transmembrane transporters (flippases). A model is presented in which TacF is required for the transport of the teichoic acid subunits across the cytoplasmic membrane. According to this model, wild-type TacF has a strict specificity for choline-containing subunits, whereas the TacF present in the choline-independent mutant strain is able to transport both choline-containing and choline-free teichoic acid chains. The proposed transport specificity of parental-type TacF for choline-containing subunits would ensure the loading of the cell wall with teichoic acid chains decorated with choline residues, which appear to be essential for the virulence of this pathogen.
Methionine Sulfoxide Reductase from the Hyperthermophilic Archaeon
Thermococcus kodakaraensis
, an Enzyme Designed To Function at Suboptimal Growth Temperatures
Authors: Fukushima Eiji , Shinka Yasuhiro , Fukui Toshiaki , Atomi Haruyuki , Imanaka Tadayuki 
Published: July 2007

ABSTRACT

Methionine sulfoxide reductase (Msr) catalyzes the thioredoxin-dependent reduction and repair of methionine sulfoxide (MetO). Although Msr genes are not present in most hyperthermophile genomes, an Msr homolog encoding an MsrA-MsrB fusion protein (MsrAB
Tk
) was present on the genome of the hyperthermophilic archaeon
Thermococcus kodakaraensis
. Recombinant proteins corresponding to MsrAB
Tk
and the individual domains (MsrA
Tk
and MsrB
Tk
) were produced, purified, and biochemically examined. MsrA
Tk
and MsrB
Tk
displayed strict substrate selectivity for Met-
S
-O and Met-
R
-O, respectively. MsrAB
Tk
, and in particular the MsrB domain of this protein, displayed an intriguing behavior for an enzyme from a hyperthermophile. While MsrAB
Tk
was relatively stable at temperatures up to 80°C (with a half-life of ∼30 min at 80°C), a 75% decrease in activity was observed after 2.5 min at 85°C, the optimal growth temperature of this archaeon. Moreover, maximal levels of MsrB activity of MsrAB
Tk
were observed at the strikingly low temperature of 30°C, which also was observed for MsrB
Tk
. Consistent with the low-temperature-specific biochemical properties of MsrAB
Tk
, the presence of the protein was greater in
T. kodakaraensis
cells grown at suboptimal temperatures (60 to 70°C) and could not be detected at 80 to 90°C. We found that the amount of intracellular MsrAB
Tk
protein increased with exposure to higher dissolved oxygen levels, but only at suboptimal growth temperatures. While measuring background rates of the Msr enzyme reactions, we observed significant levels of MetO reduction at high temperatures without enzyme. The occurrence of nonenzymatic MetO reduction at high temperatures may explain the specific absence of Msr homologs in most hyperthermophiles. Together with the fact that the presence of Msr in
T. kodakaraensis
is exceptional among the hyperthermophiles, the enzyme may represent a novel strategy for this organism to deal with low-temperature environments in which the dissolved oxygen concentrations increase.
Salinity-Dependent Switching of Osmolyte Strategies in a Moderately Halophilic Bacterium: Glutamate Induces Proline Biosynthesis in
Halobacillus halophilus
Authors: Saum Stephan H. , Müller Volker 
Published: July 2007

ABSTRACT

The moderately halophilic bacterium
Halobacillus halophilus
copes with the salinity in its environment by the production of compatible solutes. At intermediate salinities of around 1 M NaCl, cells produce glutamate and glutamine in a chloride-dependent manner (S. H. Saum, J. F. Sydow, P. Palm, F. Pfeiffer, D. Oesterhelt, and V. Müller, J. Bacteriol. 188:6808-6815, 2006). Here, we report that
H. halophilus
switches its osmolyte strategy and produces proline as the dominant solute at higher salinities (2 to 3 M NaCl). The proline biosynthesis genes
proH
,
proJ
, and
proA
were identified. They form a transcriptional unit and encode the pyrroline-5-carboxylate reductase, the glutamate-5-kinase, and the glutamate-5-semialdehyde dehydrogenase, respectively, catalyzing proline biosynthesis from glutamate. Expression of the genes was clearly salinity dependent and reached a maximum at 2.5 M NaCl, indicating that the
pro
operon is involved in salinity-induced proline biosynthesis. To address the role of anions in the process of
pro
gene activation and proline biosynthesis, we used a cell suspension system. Chloride salts lead to the highest accumulation of proline. Interestingly, chloride could be substituted to a large extent by glutamate salts. This unexpected finding was further analyzed on the transcriptional level. The cellular mRNA levels of all three
pro
genes were increased up to 90-fold in the presence of glutamate. A titration revealed that a minimal concentration of 0.2 M glutamate already stimulated
pro
gene expression. These data demonstrate that the solute glutamate is involved in the switch of osmolyte strategy from glutamate to proline as the dominant compatible solute during the transition from moderate to high salinity.
The invisible hand: how British American Tobacco precluded competition in Uzbekistan
Authors: Gilmore Anna B , McKee Martin , Collin Jeff 
Published: July 2007

Background:Tobacco industry documents provide a unique opportunity to explore the role transnational corporations (TNCs) played in shaping the poor outcomes of privatisation in the former Soviet Union (FSU). This paper examines British American Tobacco’s (BAT’s) business conduct in Uzbekistan where large-scale smuggling of BAT’s cigarettes, BAT’s reversal of tobacco control legislation and its human rights abuses of tobacco farmers have been documented previously. This paper focuses, instead, on BAT’s attitude to competition, compares BAT’s conduct with international standards and assesses its influence on the privatisation process.Methods:Analysis of BAT documents released through litigation.Results:BAT secured sole negotiator status precluding the Uzbekistan government from initiating discussions with other parties. Recognising that a competitive tender would greatly increase the cost of investment, BAT went to great lengths to avoid one, ultimately securing President Karimov’s support and negotiating a monopoly position in a closed deal. It simultaneously secured exclusion from the monopolies committee, ensuring freedom to set prices, on the basis of a spurious argument that competition would exist from imports.Other anticompetitive moves comprised including all three plants in the deal despite intending to close down two, exclusive dealing and implementing measures designed to prevent market entry by competitors. BAT also secured a large number of exemptions and privileges that further reduced the government’s revenue both on a one-off and ongoing basis.Conclusions:BAT’s corporate misbehaviour included a wide number of anticompetitive practices, contravened Organisation of Economic Cooperation and Development’s and BAT’s own business standards on competition and restricted revenue arising from privatisation. This suggests that TNCs have contributed to the failure of privatisation in the FSU. Conducting open tenders and using enforceable codes to regulate corporate conduct would help deal with some of the problems identified.
Second-hand tobacco smoke in public places in urban and rural China
Authors: Stillman Frances , Navas-Acien Ana , Ma Jiemin , Ma Shaojun , Avila-Tang Erika , Breysse Patrick , Yang Gonghuan , Samet Jonathan 
Published: July 2007

Objective:To assess airborne nicotine concentrations as an indicator of second-hand smoke (SHS) exposure in public places in both urban and rural areas of China.Design:Measurement of vapour-phase nicotine concentration using a common protocol in all locations. A total of 273 samplers were placed for 7 days in urban and rural areas of China, including Beijing and the capital city, and a county (rural) area of the following provinces: Sichuan (Chengdu/Mianzhu), Jiangxi (Nanchang/Anyi) and Henan (Zhengzhou/Xin’an).Setting:Samplers were placed in hospitals, secondary schools, city government buildings, train stations, restaurants and entertainment establishments (internet cafes, mahjong parlours and karaoke bars) in each location.Main outcome measure:The time-weighted average airborne concentration of nicotine (μg/m3) was measured by gas chromatography.Results:Airborne nicotine was detected in 91% of the locations sampled. Beijing had the highest nicotine concentrations in most indoor environments (median 3.01 μg/m3) and Chengdu had the lowest concentrations (median 0.11 μg/m3). Overall, restaurants and entertainment establishments had the highest nicotine concentrations (median 2.17 and 7.48 μg/m3, respectively). High nicotine concentrations were also found in government buildings and in train stations.Conclusions:The data collected in this study provide evidence that SHS exposure is frequent in public places in China. Environmental nicotine concentrations in China provide evidence for implementation and enforcement of smoke-free initiatives in public places in China and indicate the need for protecting the public from exposure to SHS.
Tobacco industry lawyers as “disease vectors”
Authors: Guardino Sara D , Daynard Richard A 
Published: July 2007

Objective:Despite their obligation to do so, tobacco companies often failed to conduct product safety research or, when research was conducted, failed to disseminate the results to the medical community and to the public. The tobacco company lawyers’ role in these actions was investigated with a focus on their involvement in company scientific research, claims of attorney-client privilege and work-product cover, document concealment, and litigation tactics.Methods:Searches of previously secret internal tobacco industry documents located at Tobacco Documents Online. Additional searches included court transcripts, legal cases and articles obtained through Westlaw, PubMed, and the internet.Results:Tobacco company lawyers have been involved in activities having little or nothing to do with the practice of law, including gauging and attempting to influence company scientists’ beliefs, vetting in-house scientific research, and instructing in-house scientists not to publish potentially damaging results. Additionally, company lawyers have taken steps to manufacture attorney-client privilege and work-product cover to assist their clients in protecting sensitive documents from disclosure, have been involved in the concealment of such documents, and have employed litigation tactics that have largely prevented successful lawsuits against their client companies.Conclusions:Tobacco related diseases have proliferated partly because of tobacco company lawyers. Their tactics have impeded the flow of information about the dangers of smoking to the public and the medical community. Additionally, their extravagantly aggressive litigation tactics have pushed many plaintiffs into dropping their cases before trial, thus reducing the opportunities for changes to be made to company policy in favour of public health. Stricter professional oversight is needed to ensure that this trend does not continue.
Occasional tobacco use among young adult women: a longitudinal analysis of smoking transitions
Authors: McDermott Liane , Dobson Annette , Owen Neville 
Published: July 2007

Objective:To describe prospective transitions in smoking among young adult women who were occasional smokers, and the factors associated with these transitions, by comparing sociodemographic, lifestyle and psychosocial characteristics of those who changed from occasional smoking to daily smoking, non-daily smoking or non-smoking.Design:Longitudinal study with mailed questionnaires.Participants/setting:Women aged 18–23 years in 1996 were randomly selected from the Medicare Australia database, which provides the most complete list of people in Australia.Main outcome measures:Self-reported smoking status at survey 1 (1996), survey 2 (2000) and survey 3 (2003), for 7510 participants who took part in all three surveys and who had complete data on smoking at survey 1.Results:At survey 1, 28% (n = 2120) of all respondents reported smoking. Among the smokers, 39% (n = 829) were occasional smokers. Of these occasional smokers, 18% changed to daily smoking at survey 2 and remained daily smokers at survey 3; 12% reported non-daily smoking at surveys 2 and 3; 36% stopped smoking and remained non-smokers; and 33% moved between daily, non-daily and non-smoking over surveys 2 and 3. Over the whole 7-year period, approximately half stopped smoking, one-quarter changed to daily smoking and the remainder reported non-daily smoking. Multivariate analysis identified that a history of daily smoking for ⩾6 months at baseline predicted reversion to daily smoking at follow-up. Being single and using illicit drugs were also associated with change to daily or non-daily smoking, whereas alcohol consumption was associated with non-daily smoking only. Compared with stopping smoking, the change to daily smoking was significantly associated with having intermediate educational qualifications. No significant associations with depression and perceived stress were observed in the multivariate analysis.Conclusions:Interventions to reduce the prevalence of smoking among young women need to take account of occasional smokers, who made up 39% of all smokers in this study. Targeted interventions to prevent the escalation to daily smoking and to promote cessation should allow for the social context of smoking with alcohol and other drugs, and social and environmental influences in vocational education and occupational settings.
Legislation reduces exposure to second-hand tobacco smoke in New Zealand bars by about 90%
Authors: Fernando Dinusha , Fowles Jefferson , Woodward Alistair , Christophersen Annemarie , Dickson Stuart , Hosking Matthew , Berezowski Richard , Lea Rod A 
Published: July 2007

Aim:To measure exposure to second-hand smoke (SHS) in New Zealand bars before and after comprehensive smoke-free legislation enacted on 10 December 2004.Methods:Cotinine is the main specific metabolite of nicotine and a well-established biomarker for SHS exposure. We measured cotinine levels in saliva of non-smoking volunteers before and after a 3 h visit to 30 randomly selected bars in 3 cities across the country. Two measures of cotinine before the smoke-free law change during winter and spring 2004, and two follow-up measurements in the same volunteers and venues during winter and spring 2005, were included.Results:Before the smoke-free law change, in all bars and in all volunteers, exposure to SHS was evident with an average increase in saliva cotinine of 0.66 ng/ml (SE 0.03 ng/ml). Increases in cotinine correlated strongly with the volunteers’ subjective observation of ventilation, air quality and counts of lit cigarettes. However, even venues that were judged to be “seemingly smoke free” with “good ventilation” produced discernable levels of SHS exposure. After the law change, there remained some exposure to SHS, but at much lower levels (mean saliva cotinine increase of 0.08 ng/ml, SE 0.01 ng/ml). Smoking indoors in bars was almost totally eliminated: in 2005 only one lit cigarette was observed in 30 visits.Conclusions:Comprehensive smoke-free legislation in New Zealand seems to have reduced exposure of bar patrons to SHS by about 90%. Residual exposures to SHS in bars do not result from illicit smoking indoors.