bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations
Authors: Delpérée Christine , Lutts Stanley 
Published: March 2008

Abstract In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants (Solanum lycopersicum L. var. Ailsa Craig) were exposed under controlled environmental conditions to a high dose of this heavy metal (250 μM CdCl2) in nutrient solution for 7 and 14 d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease in the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance (gl) and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSII (Fv/Fm) was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.
Alfvén quasi-periodic oscillations in magnetars
Authors: Sotani H. , Kokkotas K. D. , Stergioulas N. 
Published: March 2008

Abstract
We investigate torsional Alfvén oscillations of relativistic stars with a global dipole magnetic field, via two-dimensional numerical simulations. We find that (i) there exist two families of quasi-periodic oscillations (QPOs) with harmonics at integer multiples of the fundamental frequency, (ii) the lower-frequency QPO is related to the region of closed field lines, near the equator, while the higher-frequency QPO is generated near the magnetic axis, (iii) the QPOs are long-lived, (iv) for the chosen form of dipolar magnetic field, the frequency ratio of the lower to upper fundamental QPOs is ∼0.6, independent of the equilibrium model or of the strength of the magnetic field, and (v) within a representative sample of equations of state and of various magnetar masses, the Alfvén QPO frequencies are given by accurate empirical relations that depend only on the compactness of the star and on the magnetic field strength. The lower and upper QPOs can be interpreted as corresponding to the edges or turning points of an Alfvén continuum, according to the model proposed by Levin (2007). Several of the low-frequency QPOs observed in the X-ray tail of SGR 1806-20 can readily be identified with the Alfvén QPOs we compute. In particular, one could identify the 18- and 30-Hz observed frequencies with the fundamental lower and upper QPOs, correspondingly, while the observed frequencies of 92 and 150 Hz are then integer multiples of the fundamental upper QPO frequency (three and five times, correspondingly). With this identification, we obtain an upper limit on the strength of the magnetic field of SGR 1806-20 (if is dominated by a dipolar component) between ∼3 and 7 × 1015 G. Furthermore, we show that an identification of the observed frequency of 26 Hz with the frequency of the fundamental torsional ℓ= 2 oscillation of the magnetar's crust is compatible with a magnetar mass of about from 1.4 to 1.6 M⊙ and an equation of state (EOS) that is very stiff (if the magnetic field strength is near its upper limit) or moderately stiff (for lower values of the magnetic field).
Hormone Therapy, Dilemmas, Medical Decisions
Authors: Schulkin Jay 
Published: March 2008

The question of why women, in consultation with their physicians, should choose hormone therapy (HT) in response to menopause represents a renewed controversy at the beginning of the new century. Conflicting messages regarding the health risks and benefits of HT have been conveyed in the mainstream media, especially information in the media regarding the results of large-scale studies of the health impact of hormone therapy. Women who have been on one or another of the hormone replacement regimes have been forced to reconsider continuing on HT. Doctors who suggest these hormones to their patients are somewhat confused, as are perimenopausal women who are considering HT. Pharmaceutical companies that produce these compounds are worried, and public health officials are on the defensive.Media coverage of HT research has been extensive. In particular, two large-scale studies, one here in the U.S. (the Women's Health Initiative, or WHI) and the other in Great Britain, have recently cast a negative light on the use of hormone therapy, after years of routine prescription of HT for menopausal women.
Assessing Laws and Legal Authorities for Public Health Emergency Legal Preparedness
Authors: Kamoie Brian , Pestronk Robert M. , Baldridge Peter , Fidler David , Devlin Leah , Mensah George A. , Doney Michael 
Published: March 2008

Public health legal preparedness begins with effective legal authorities, and law provides a key foundation for public health practice in the United States. Laws not only create public health agencies and fund them, but also authorize and impose duties upon government to protect the public's health while preserving individual liberties. As a result, law is an essential tool in public health practice and is one element of public health infrastructure, as it defines the systems and relationships within which public health practitioners operate.For purposes of this paper, law can be defined as a rule of conduct derived from federal or state constitutions, statutes, local laws, judicial opinions, administrative rules and regulations, international codes, or other pronouncements by entities authorized to prescribe conduct in a legally binding manner. Public health legal preparedness, a subset of public health preparedness, is defined as attainment of legal benchmarks within a public health system.
Improving Cross-Sectoral and Cross-Jurisdictional Coordination for Public Health Emergency Legal Preparedness
Authors: Bullard Cheryl H. , Hogan Rick D. , Penn Matthew S. , Ferris Janet , Cleland John , Stier Daniel , Davis Ronald M. , Allan Susan , Van de Putte Leticia , Caine Virginia , Besser Richard E. , Gravely Steven 
Published: March 2008

This paper is one of the four interrelated action agenda papers resulting from the National Summit on Public Health Legal Preparedness (Summit) convened in June 2007 by the Centers for Disease Control and Prevention (CDC) and multi-disciplinary partners. Each of the action agenda papers deals with one of the four core elements of public health legal preparedness: laws and legal authorities; competency in using those laws; coordination of law-based public health actions; and information. Options presented in this paper are for consideration by policy makers and practitioners — in all jurisdictions and all relevant sectors and disciplines — with responsibilities for all-hazards emergency preparedness.Advancing and protecting the public's health depends upon the coordination of actions by many, diverse partners. For effective public health preparedness, there must be effective coordination of legal tools and law-based strategies across local, state, tribal, and federal jurisdictions, and also across sectors such as public health, health care, emergency management, education, law enforcement, community design, and academia.
Distribution of virF/lcrF‐positive Yersinia pseudotuberculosis Serotype O:3 at Farm Level
Authors: Niskanen T. , Laukkanen R. , Fredriksson‐Ahomaa M. , Korkeala H. 
Published: March 2008

SummaryThe distribution and persistence of pathogenic, virF/lcrF‐positive Yersinia pseudotuberculosis were investigated in pigs and in the pig house environment during rearing to determine possible contamination routes of early infections. Based on Y. pseudotuberculosis‐positive tonsils of slaughter pigs in our previous study, Y. pseudotuberculosis‐positive animals were traced back to the farms. Eight farms were visited from 6–10 months later, and a total of 155 pooled and six individual faecal samples from pigs and 116 pooled environmental samples were collected for analysis by different culture methods. Four of the eight farms were found to be Y. pseudotuberculosis‐positive. All positive faecal samples were obtained from fattening pigs, with prevalence varying from 5% to 71% on positive farms. Sows, boars and suckling piglets were Y. pseudotuberculosis‐negative on all farms. Most Y. pseudotuberculosis‐positive farms (three of four) were on a one‐site production system, which had a higher prevalence of Y. pseudotuberculosis (5–26%) among fattening pigs than the all‐in, all‐out system (1–5%). All Y. pseudotuberculosis isolates belonged to serotype O:3 and carried the virF/lcrF gene on the virulence plasmid. Biotypes 2 and 3 were involved, the latter in one isolate and not being previously reported in pigs. Altogether 53 isolates from 16 positive samples were characterized with pulsed‐field gel electrophoresis (PFGE). Using SpeI, NotI and XbaI enzymes, four, three and two different PFGE patterns were obtained respectively. A total of nine different genotypes were identified when the profiles of the enzymes were combined. The most common genotypes were gIV, found on three, and gXII, found on two of the four Y. pseudotuberculosis‐positive farms. The same genotypes previously detected in pig tonsils were present in pig faeces from the same farm, indicating that some Y. pseudotuberculosis strains can persist in the pig house environment.
Pyrazinamide Resistance and
pncA
Gene Mutations in
Mycobacterium tuberculosis
Authors: Juréen Pontus , Werngren Jim , Toro Juan-Carlos , Hoffner Sven 
Published: March 2008

ABSTRACT

Thirty-four pyrazinamide-resistant and 37 pyrazinamide-susceptible
Mycobacterium tuberculosis
complex strains were analyzed for
pncA
gene mutations. None of the sensitive strains had any mutations, apart from silent mutations, whereas all but one resistant strain showed
pncA
mutations. By using sequencing as a means of early resistance detection, the inconsistency of phenotypic pyrazinamide assays can be circumvented.
Entecavir Exhibits Inhibitory Activity against Human Immunodeficiency Virus under Conditions of Reduced Viral Challenge
Authors: Lin Pin-Fang , Nowicka-Sans Beata , Terry Brian , Zhang Sharon , Wang Chunfu , Fan Li , Dicker Ira , Gali Volodymyr , Higley Helen , Parkin Neil , Tenney Daniel , Krystal Mark , Colonno Richard 
Published: March 2008

ABSTRACT
Entecavir (ETV) was developed for the treatment of chronic hepatitis B virus (HBV) infection and is globally approved for that indication. Initial preclinical studies indicated that ETV had no significant activity against human immunodeficiency virus type 1 (HIV-1) in cultured cell lines at physiologically relevant ETV concentrations, using traditional anti-HIV assays. In response to recent clinical observations of anti-HIV activity of ETV in HIV/HBV-coinfected patients not receiving highly active antiretroviral therapy (HAART), additional investigative studies were conducted to expand upon earlier results. An extended panel of HIV-1 laboratory and clinical strains and cell types was tested against ETV, along with a comparison of assay methodologies and resistance profiling. These latest studies confirmed that ETV has only weak activity against HIV, using established assay systems. However, a >100-fold enhancement of antiviral activity (equivalent to the antiviral activity of lamivudine) could be obtained when assay conditions were modified to reduce the initial viral challenge. Also, the selection of a M184I virus variant during the passage of HIV-1 at high concentrations of ETV confirmed that ETV can exert inhibitory pressure on the virus. These findings may have a significant impact on how future assays are performed with compounds to be used in patients infected with HIV. These results support the recommendation that ETV therapy should be administered in concert with HAART for HIV/HBV-coinfected patients.
Inhibitors of Strand Transfer That Prevent Integration and Inhibit Human T-Cell Leukemia Virus Type 1 Early Replication
Authors: Rabaaoui Samira , Zouhiri Fatima , Lançon Agnès , Leh Hervé , d'Angelo Jean , Wattel Eric 
Published: March 2008

ABSTRACT
The replication of the retrovirus human T-cell leukemia virus type 1 (HTLV-1) is linked to the development of lymphoid malignancies and inflammatory diseases. Data from in vitro, ex vivo, and in vivo studies have revealed that no specific treatment can prevent or block HTLV-1 replication and therefore that there is no therapy for the prevention and/or treatment of HTLV-1-associated diseases in infected individuals. HTLV-1 and human immunodeficiency virus type 1 (HIV-1) integrases, the enzymes that specifically catalyze the integration of these retroviruses in host cell DNA, share important structural properties, suggesting that compounds that inhibit HIV-1 integration could also inhibit HTLV-1 integration. We developed quantitative assays to test, in vitro and ex vivo, the efficiencies of styrylquinolines and diketo acids, the two main classes of HIV-1 integrase inhibitors. The compounds were tested in vitro in an HTLV-1 strand-transfer reaction and ex vivo by infection of fresh peripheral blood lymphocytes with lethally irradiated HTLV-1-positive cells. In vitro, four styrylquinoline compounds and two diketo acid compounds significantly inhibited HTLV-1 integration in a dose-dependent manner. All compounds active in vitro decreased cell proliferation ex vivo, although at low concentrations; they also dramatically decreased both normalized proviral loads and the number of integration events during experimental ex vivo primary infection. Accordingly, diketo acids and styrylquinolines are the first drugs that produce a specific negative effect on HTLV-1 replication in vitro and ex vivo, suggesting their potential efficiency for the prevention and treatment of HTLV-1-associated diseases.
The Lys234Arg Substitution in the Enzyme SHV-72 Is a Determinant for Resistance to Clavulanic Acid Inhibition
Authors: Mendonça Nuno , Manageiro Vera , Robin Frédéric , Salgado M. José , Ferreira Eugénia , Caniça Manuela , Bonnet Richard 
Published: March 2008

ABSTRACT

The new β-lactamase SHV-72 was isolated from clinical
Klebsiella pneumoniae
INSRA1229, which exhibited the unusual association of resistance to the amoxicillin-clavulanic acid combination (MIC, 64 μg/ml) and susceptibility to cephalosporins, aztreonam, and imipenem. SHV-72 (pI 7.6) harbored the three amino acid substitutions Ile8Phe, Ala146Val, and Lys234Arg. SHV-72 had high catalytic efficiency against penicillins (
k
cat
/
K

m

, 35 to 287 μM
−1
·s
−1
) and no activity against oxyimino β-lactams. The concentration of clavulanic acid necessary to inhibit the enzyme activity by 50% was 10-fold higher for SHV-72 than for SHV-1. Molecular-dynamics simulation suggested that the Lys234Arg substitution in SHV-72 stabilized an atypical conformation of the Ser130 side chain, which moved the Oγ atom of Ser130 around 3.5 Å away from the key Oγ atom of the reactive serine (Ser70). This movement may therefore decrease the susceptibility to clavulanic acid by preventing cross-linking between Ser130 and Ser70.
Genetic and Physiological Effects of Noncoherent Visible Light Combined with Hydrogen Peroxide on
Streptococcus mutans
in Biofilm
Authors: Steinberg Doron , Moreinos Daniel , Featherstone John , Shemesh Moshe , Feuerstein Osnat 
Published: March 2008

ABSTRACT

Oral biofilms are associated with the most common infections of the oral cavity. Bacteria embedded in the biofilms are less sensitive to antibacterial agents than planktonic bacteria are. Recently, an antibacterial synergic effect of noncoherent blue light and hydrogen peroxide (H
2
O
2
) on planktonic
Streptococcus mutans
was demonstrated. In this study, we tested the effect of a combination of light and H
2
O
2
on the vitality and gene expression of
S. mutans
embedded in biofilm. Biofilms of
S. mutans
were exposed to visible light (wavelengths, 400 to 500 nm) for 30 or 60 s (equivalent to 34 or 68 J/cm
2
) in the presence of 3 to 300 mM H
2
O
2
. The antibacterial effect was assessed by microbial counts of each treated sample compared with that of the control. The effect of light combined with H
2
O
2
on the different layers of the biofilm was evaluated by confocal laser scanning microscopy. Gene expression was determined by real-time reverse transcription-PCR. Our results show that noncoherent light, in combination with H
2
O
2
, has a synergistic antibacterial effect through all of the layers of the biofilm. Furthermore, this treatment was more effective against bacteria in biofilm than against planktonic bacteria. The combined light and H
2
O
2
treatment up-regulated the expression of several genes such as
gtfB
,
brp
,
smu630
, and
comDE
but did not affect
relA
and
ftf
. The ability of noncoherent visible light in combination with H
2
O
2
to affect bacteria in deep layers of the biofilm suggests that this treatment may be applied in biofilm-related diseases as a minimally invasive antibacterial procedure.
Rapid Point-of-Care Test To Detect Broad Ranges of Protective Antigen-Specific Immunoglobulin G Concentrations in Recipients of the U.S.-Licensed Anthrax Vaccine
Authors: Bienek Diane R. , Biagini Raymond E. , Charlton David G. , Smith Jerome P. , Sammons Deborah L. , Robertson Shirley A. 
Published: March 2008

ABSTRACT
Currently, there is no routine monitoring of an immune response to the anthrax vaccine. Simple on-site tests are needed to evaluate the antibody response of anthrax-vaccinated individuals in the Armed Forces and others at high risk. Using a prototype lateral flow assay (LFA) (R. E. Biagini, D. L. Sammons, J. P. Smith, B. A. MacKenzie, C. A. F. Striley, J. E. Snawder, S. A. Robertson, and C. P. Quinn, Clin. Vaccine Immunol. 13:541-546, 2006), we investigated the agreement between a validated anthrax protective antigen (PA) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and the LFA for 335 unvaccinated and vaccinated subjects. We also investigated the performance of the LFA under the following conditions: thermal shock (i.e., thermal cycling between temperature extremes), high temperature/high relative humidity, high temperature/low relative humidity, and low temperature/low relative humidity. With the anti-PA ELISA used as a standard, the LFA was shown to be optimally diagnostic at 11 μg/ml anti-PA-specific IgG. At this concentration, the LFA specificity and sensitivity were 98% (95% confidence interval [CI], 97% to 100%) and 92% (CI, 88% to 97%), respectively. Receiver operating characteristic curve analysis yielded an area under the curve value of 0.988 (CI, 0.976 to 1.00), suggesting that the LFA is an extremely accurate diagnostic test. For ≤4 or ≥50 μg/ml PA-specific IgG, the LFA results for each environmental condition were identical to those obtained in the laboratory. These data indicate that this rapid point-of-care test would be a feasible tool in monitoring the serological antibody responses of individuals that have been vaccinated against anthrax.
Emergence of a Tetracycline-ResistantCampylobacter jejuniClone Associated with Outbreaks of Ovine Abortion in the United States
Authors: Sahin Orhan , Plummer Paul J. , Jordan Dianna M. , Sulaj Kapllan , Pereira Sonia , Robbe-Austerman Suelee , Wang Liping , Yaeger Michael J. , Hoffman Lorraine J. , Zhang Qijing 
Published: March 2008

ABSTRACTCampylobacterinfection is one of the major causes of ovine abortions worldwide. Historically,Campylobacter fetussubsp.fetuswas the major cause ofCampylobacter-associated abortion in sheep; however,Campylobacter jejuniis increasingly associated with sheep abortions. We examined the species distribution, genotypes, and antimicrobial susceptibilities of abortion-associatedCampylobacterisolates obtained from multiple lambing seasons on different farms in Iowa, Idaho, South Dakota, and California. We found thatC. jejunihas replacedC. fetusas the predominantCampylobacterspecies causing sheep abortion in the United States. Most strikingly, the vast majority (66 of 71) of theC. jejuniisolates associated with sheep abortion belong to a single genetic clone, as determined by pulsed-field gel electrophoresis, multilocus sequence typing, andcmpgene (encoding the major outer membrane protein) sequence typing. The in vitro antimicrobial susceptibilities of these isolates to the antibiotics that are routinely used in food animal production were determined using the agar dilution test. All of the 74 isolates were susceptible to tilmicosin, florfenicol, tulathromycin, and enrofloxacin, and 97% were sensitive to tylosin. However, all were resistant to tetracyclines, the only antibiotics currently approved in the United States for the treatment ofCampylobacterabortion in sheep. This finding suggests that feeding tetracycline for the prevention ofCampylobacterabortions is ineffective and that other antibiotics should be used for the treatment of sheep abortions in the United States. Together, these results indicate that a single tetracycline-resistantC. jejuniclone has emerged as the major cause ofCampylobacter-associated sheep abortion in the United States.
Emergence and Dissemination of a Community-Associated Methicillin-Resistant Panton-Valentine Leucocidin-Positive
Staphylococcus aureus
Clone Sharing the Sequence Type 5 Lineage with the Most Prevalent Nosocomial Clone in the Same Region of Argentina
Authors: Sola Claudia , Saka Hector A. ,   the Cordoba MRSA Collaborative Study Group, Vindel Ana , Bocco José Luis 
Published: March 2008

ABSTRACT

Epidemiological surveillance for community-associated methicillin-resistant
Staphylococcus aureus
revealed prevalences of 33% and 13% in pediatric and adult patients, respectively, in Cordoba, Argentina, in 2005. This study describes for the first time the emergence and dissemination of the sequence type 5 (ST5) lineage as the most prevalent clone (89%) (pulsed-field gel electrophoresis type I-ST5-staphylococcal cassette chromosome type IVa-
spa
type 311) harboring the Panton-Valentine leukocidin and enterotoxin A genes.
Detection of Diarrheagenic
Escherichia coli
by Use of Melting-Curve Analysis and Real-Time Multiplex PCR
Authors: Guion Chase E. , Ochoa Theresa J. , Walker Christopher M. , Barletta Francesca , Cleary Thomas G. 
Published: March 2008

ABSTRACT

Diarrheagenic
Escherichia coli
strains are important causes of diarrhea in children from the developing world and are now being recognized as emerging enteropathogens in the developed world. Current methods of detection are too expensive and labor-intensive for routine detection of these organisms to be practical. We developed a real-time fluorescence-based multiplex PCR for the detection of all six of the currently recognized classes of diarrheagenic
E. coli
. The primers were designed to specifically amplify eight different virulence genes in the same reaction:
aggR
for enteroaggregative
E. coli
,
stIa
/
stIb
and
lt
for enterotoxigenic
E. coli
,
eaeA
for enteropathogenic
E. coli
and Shiga toxin-producing
E. coli
(STEC),
stx
1
and
stx
2
for STEC,
ipaH
for enteroinvasive
E. coli
, and
daaD
for diffusely adherent
E. coli
(DAEC). Eighty-nine of ninety diarrheagenic
E. coli
and 36/36 nonpathogenic
E. coli
strains were correctly identified using this approach (specificity, 1.00; sensitivity, 0.99). The single false negative was a DAEC strain. The total time between preparation of DNA from
E. coli
colonies on agar plates and completion of PCR and melting-curve analysis was less than 90 min. The cost of materials was low. Melting-point analysis of real-time multiplex PCR is a rapid, sensitive, specific, and inexpensive method for detection of diarrheagenic
E. coli
.