bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of Nutlin‐3 on laryngeal carcinoma cell lines with wild‐type p53: a promising treatment strategy for laryngeal carcinoma
Authors: Arya A.K. , El‐Fert A. , Devlin T. , Jones T.M. , Boyd M.T. 
Published: June 2008

Objectives.  Abnormalities of the p53 gene are the commonest mutation found in all human cancers, and evidence suggests this may influence response to chemoradiotherapeutic agents. Nutlin‐3, the small molecule inhibitor of MDM2/p53 interaction, has been shown to be effective in prostate cancer and leukemia by inducing apoptosis in cells with functioning p53. It is this effect that we wished to demonstrate in laryngeal carcinoma.Methods.  Eight cell lines derived from patients with laryngeal carcinoma were used in this study. Other cell lines from other sites of the head and neck were deliberately excluded to avoid using heterogeneous cell types. The p53 status of the cell lines was determined using direct sequence analysis of the entire coding length of the gene (exons 2–11). Cell lines were treated with Nutlin‐3 for 48 h and surviving cells were counted using the Beckman Coulter Counter. Flow cytometry was used to determine cell cycle characteristics.Results.  Four cell lines harboured p53 mutations, four contained wild‐type p53. All cell lines with wild type p53 were sensitive to the effects of Nutlin‐3 in a time and dose dependant manner. Cell lines harbouring mutant p53 were resistant to Nutlin‐3. Flow cytometry demonstrated an increase in p53‐dependant apoptosis in responsive cell lines.Conclusions.  This is the first study to demonstrate that Nutlin‐3 is effective in laryngeal cancer cell lines with wild‐type p53. The clinical application of Nutlin‐3 could provide a new and targeted treatment option for patients with laryngeal carcinoma.
The antidepressant sertraline downregulates Akt and has activity against melanoma cells
Authors: Reddy Kalpana K. , Lefkove Benjamin , Chen Lan Bo , Govindarajan Baskaran , Carracedo Arkaitz , Velasco Guillermo , Carrillo Carol O. , Bhandarkar Sulochana S. , Owens Michael J. , Mechta‐Grigoriou Fatima , Arbiser Jack L. 
Published: June 2008

SummaryMelanoma is a common malignancy which is poorly responsive to chemotherapy and radiation. One of the major reasons melanoma responds poorly to these modalities is constitutive expression of Akt, which protects against apoptosis. The antidepressant sertraline was found to be a potent cytotoxic agent against A375 human melanoma. To determine the mechanism by which sertraline kills melanoma cells, Western blot analysis of signaling molecules, including phosphorylated Akt, caspase 9 and phospho‐p70 S6 kinase was performed. Finally, the effects of sertraline on A375 xenografts in mice were assessed. Sertaline potently inhibited the phosphorylation of Akt, and caused cell death through induction of endoplasmic reticulum in vitro. Sertraline monotherapy demonstrated activity against A375 xenografts in vivo. Akt is a major cause of resistance of melanoma to current therapy. Antidepressants are commonly used to prevent interferon‐induced depression. Use of antidepressants that decrease Akt may improve the efficacy of interferon and other therapies against melanoma. Further studies are needed to elucidate whether sertraline acts as an Akt inhibitor in melanoma.
Use of Vaxfectin Adjuvant with DNA Vaccine Encoding the Measles Virus Hemagglutinin and Fusion Proteins Protects Juvenile and Infant Rhesus Macaques against Measles Virus
Authors: Pan Chien-Hsiung , Jimenez Gretchen S. , Nair Nitya , Wei Qun , Adams Robert J. , Polack Fernando P. , Rolland Alain , Vilalta Adrián , Griffin Diane E. 
Published: June 2008

ABSTRACT
A measles virus vaccine for infants under 6 months of age would help control measles. DNA vaccines hold promise, but none has provided full protection from challenge. Codon-optimized plasmid DNAs encoding the measles virus hemagglutinin and fusion glycoproteins were formulated with the cationic lipid-based adjuvant Vaxfectin. In mice, antibody and gamma interferon (IFN-γ) production were increased by two- to threefold. In macaques, juveniles vaccinated at 0 and 28 days with 500 μg of DNA intradermally or with 1 mg intramuscularly developed sustained neutralizing antibody and H- and F-specific IFN-γ responses. Infant monkeys developed sustained neutralizing antibody and T cells secreting IFN-γ and interleukin-4. Twelve to 15 months after vaccination, vaccinated monkeys were protected from an intratracheal challenge: viremia was undetectable by cocultivation and rashes did not appear, while two naïve monkeys developed viremia and rashes. The use of Vaxfectin-formulated DNA is a promising approach to the development of a measles vaccine for young infants.
Mutagenesis and Nuclear Magnetic Resonance Analyses of the Fusion Peptide of
Helicoverpa armigera
Single Nucleocapsid Nucleopolyhedrovirus F Protein
Authors: Tan Ying , Jiang Ling , Wang Manli , Yin Feifei , Deng Fei , Liu Maili , Hu Zhihong , Wang Hualin 
Published: June 2008

ABSTRACT

The entry of enveloped viruses into cells is normally mediated by fusion between viral and cellular membranes, in which the fusion peptide plays a crucial role. The fusion peptides of group II nucleopolyhedrovirus (NPV) F proteins are quite conserved, with a hydrophobic region located at the N terminal of the F
1
fragment. For this report, we used mutagenesis and nuclear magnetic resonance (NMR) to study the structure and function of the fusion peptide of the
Helicoverpa armigera
single-nucleocapsid NPV (HearNPV) F protein (HaF). Five mutations in the fusion peptide of HaF, N
1
G, N
1
L, I
2
N, G
3
L, and D
11
L, were generated separately, and the mutated
f
genes were transformed into the
f
-null HearNPV bacmid. The mutations N
1
L, I
2
N, and D
11
L were found to completely abolish the ability of the recombinant bacmids to produce infectious budded virus, while the mutations N
1
G and G
3
L did not. The low-pH-induced envelope fusion assay demonstrated that the N
1
G substitution increased the fusogenicity of HaF, while the G
3
L substitution reduced its fusogenicity. NMR spectroscopy was used to determine the structure of a synthetic fusion peptide of HaF in the presence of sodium dodecyl sulfate micelles at pH 5.0. The fusion peptide appeared to be an amphiphilic structure composed of a flexible coil in the N terminus from N
1
to N
5
, a 3
10
-helix from F
6
to G
8
, a turn at S
9
, and a regular α-helix from V
10
to D
19
. The data provide the first NMR structure of a baculovirus fusion peptide and allow us to further understand the relationship of structure and function of the fusion peptide.
Disparity between Levels of In Vitro Neutralization of Vaccinia Virus by Antibody to the A27 Protein and Protection of Mice against Intranasal Challenge
Authors: Fogg Christiana N. , Americo Jeffrey L. , Earl Patricia L. , Resch Wolfgang , Aldaz-Carroll Lydia , Eisenberg Roselyn J. , Cohen Gary H. , Moss Bernard 
Published: June 2008

ABSTRACT
Immunization with recombinant proteins may provide a safer alternative to live vaccinia virus for prophylaxis of poxvirus infections. Although antibody protects against vaccinia virus infection, the mechanism is not understood and the selection of immunogens is daunting as there are dozens of surface proteins and two infectious forms known as the mature virion (MV) and the enveloped virion (EV). Our previous studies showed that mice immunized with soluble forms of EV membrane proteins A33 and B5 and MV membrane protein L1 or passively immunized with antibodies to these proteins survived an intranasal challenge with vaccinia virus. The present study compared MV protein A27, which has a role in virus attachment to glycosaminoglycans on the cell surface, to L1 with respect to immunogenicity and protection. Although mice developed similar levels of neutralizing antibody after immunizations with A27 or L1, A27-immunized mice exhibited more severe disease upon an intranasal challenge with vaccinia virus. In addition, mice immunized with A27 and A33 were not as well protected as mice receiving L1 and A33. Polyclonal rabbit anti-A27 and anti-L1 IgG had equivalent MV-neutralizing activities when measured by the prevention of infection of human or mouse cells or cells deficient in glycosaminoglycans or by adding antibody prior to or after virus adsorption. Nevertheless, the passive administration of antibody to A27 was poorly protective compared to the antibody to L1. These studies raise questions regarding the basis for antibody protection against poxvirus disease and highlight the importance of animal models for the early evaluation of vaccine candidates.
Molecular Characterization of the Heparin-Dependent Transduction Domain on the Capsid of a Novel Adeno-Associated Virus Isolate, AAV(VR-942)
Authors: Schmidt Michael , Govindasamy Lakshmanan , Afione Sandra , Kaludov Nick , Agbandje-McKenna Mavis , Chiorini John A. 
Published: June 2008

ABSTRACT

A new adeno-associated virus (AAV), referred to as AAV(VR-942), has been isolated as a contaminant of adenovirus strain simian virus 17. The sequence of the
rep
gene places it in the AAV serotype 2 (AAV2) complementation group, while the capsid is only 88% identical to that of AAV2. High-level AAV(VR-942) transduction activity requires cell surface heparan sulfate proteoglycans, although AAV(VR-942) lacks residues equivalent to the AAV2 R585 and R588 amino acid residues essential for mediating the interaction of AAV2 with the heparan sulfate proteoglycan receptor. Instead, AAV(VR-942) uses a distinct transduction region. This finding shows that distinct domains on different AAV isolates can be responsible for the same activities.
Interaction of Hepatitis C Virus Nonstructural Protein 5A with Core Protein Is Critical for the Production of Infectious Virus Particles
Authors: Masaki Takahiro , Suzuki Ryosuke , Murakami Kyoko , Aizaki Hideki , Ishii Koji , Murayama Asako , Date Tomoko , Matsuura Yoshiharu , Miyamura Tatsuo , Wakita Takaji , Suzuki Tetsuro 
Published: June 2008

ABSTRACTNonstructural protein 5A (NS5A) of the hepatitis C virus (HCV) possesses multiple and diverse functions in RNA replication, interferon resistance, and viral pathogenesis. Recent studies suggest that NS5A is involved in the assembly and maturation of infectious viral particles; however, precisely how NS5A participates in virus production has not been fully elucidated. In the present study, we demonstrate that NS5A is a prerequisite for HCV particle production as a result of its interaction with the viral capsid protein (core protein). The efficiency of virus production correlated well with the levels of interaction between NS5A and the core protein. Alanine substitutions for the C-terminal serine cluster in domain III of NS5A (amino acids 2428, 2430, and 2433) impaired NS5A basal phosphorylation, leading to a marked decrease in NS5A-core interaction, disturbance of the subcellular localization of NS5A, and disruption of virion production. Replacing the same serine cluster with glutamic acid, which mimics the presence of phosphoserines, partially preserved the NS5A-core interaction and virion production, suggesting that phosphorylation of these serine residues is important for virion production. In addition, we found that the alanine substitutions in the serine cluster suppressed the association of the core protein with viral genome RNA, possibly resulting in the inhibition of nucleocapsid assembly. These results suggest that NS5A plays a key role in regulating the early phase of HCV particle formation by interacting with core protein and that its C-terminal serine cluster is a determinant of the NS5A-core interaction.
Regulation of Pyrimidine Biosynthetic Gene Expression in Bacteria: Repression without Repressors
Authors: Turnbough Charles L. , Switzer Robert L. 
Published: June 2008

SUMMARY

DNA-binding repressor proteins that govern transcription initiation in response to end products generally regulate bacterial biosynthetic genes, but this is rarely true for the pyrimidine biosynthetic (
pyr
) genes. Instead, bacterial
pyr
gene regulation generally involves mechanisms that rely only on regulatory sequences embedded in the leader region of the operon, which cause premature transcription termination or translation inhibition in response to nucleotide signals. Studies with
Escherichia coli
and
Bacillus subtilis pyr
genes reveal a variety of regulatory mechanisms. Transcription attenuation via UTP-sensitive coupled transcription and translation regulates expression of the
pyrBI
and
pyrE
operons in enteric bacteria, whereas nucleotide effects on binding of the PyrR protein to
pyr
mRNA attenuation sites control
pyr
operon expression in most gram-positive bacteria. Nucleotide-sensitive reiterative transcription underlies regulation of other
pyr
genes. With the
E. coli pyrBI
,
carAB
,
codBA
, and
upp-uraA
operons, UTP-sensitive reiterative transcription within the initially transcribed region (ITR) leads to nonproductive transcription initiation. CTP-sensitive reiterative transcription in the
pyrG
ITRs of gram-positive bacteria, which involves the addition of G residues, results in the formation of an antiterminator RNA hairpin and suppression of transcription attenuation. Some mechanisms involve regulation of translation rather than transcription. Expression of the
pyrC
and
pyrD
operons of enteric bacteria is controlled by nucleotide-sensitive transcription start switching that produces transcripts with different potentials for translation. In
Mycobacterium smegmatis
and other bacteria, PyrR modulates translation of
pyr
genes by binding to their ribosome binding site. Evidence supporting these conclusions, generalizations for other bacteria, and prospects for future research are presented.
Evolutionary Persistence of the Molybdopyranopterin-Containing Sulfite Oxidase Protein Fold
Authors: Workun Gregory J. , Moquin Kamila , Rothery Richard A. , Weiner Joel H. 
Published: June 2008

SUMMARY

The importance of molybdoenzymes is exemplified both by the debilitating and fatal human diseases caused by their deficiency and by their persistence throughout evolution. Here, we show that the protein fold of the molybdopyranopterin-containing domain of sulfite oxidase (the SUOX fold) can be found in all three domains of life. Analyses of sequence data and protein structure comparisons (secondary structure matching) show that the SUOX fold is found in enzymes that have quite distinct macromolecular architectures comprising one or more domains and sometimes subsidiary subunits. These are summarized as follows: (i) animal SUOXs that contain an N-terminal cytochrome
b
5
domain and an SUOX fold fused to a C-terminal dimerization domain; (ii) plant SUOX that contains an SUOX fold fused to a C-terminal dimerization domain; (iii) the YedY protein from
Escherichia coli
, which comprises only the SUOX fold; (iv) the sulfite dehydrogenase from
Starkeya novella
that contains the SUOX fold, a dimerization domain, and an additional
c
-type cytochrome subunit; and (v) the plant-type nitrate reductases, exemplified by that of
Pichia angusta
, that contain an N-terminal SUOX fold, a dimerization domain, a cytochrome
b
5
domain, and a C-terminal NADH binding flavin adenine dinucleotide-containing domain. We used the primary sequences of the proteins containing an SUOX fold to mine 559 sequences of related proteins. A phylogeny of a nonredundant subset of these sequences was generated, and the resultant clades were categorized by sequence motif analyses in the context of the available protein structures. Based on the motif analyses, cladistics, and domain conservations, we are able to postulate a plausible pathway of SUOX fold enzyme evolution.
Ozone exposure, antioxidant genes, and lung function in an elderly cohort: VA normative aging study
Authors: Alexeeff S E , Litonjua A A , Wright R O , Baccarelli A , Suh H , Sparrow D , Vokonas P S , Schwartz J 
Published: June 2008

Background:Ozone (O3) exposure is known to cause oxidative stress. This study investigated the acute effects of O3on lung function in the elderly, a suspected risk group. It then investigated whether genetic polymorphisms of antioxidant genes (heme oxygenase-1 (HMOX1) and glutathioneS-transferase pi (GSTP1)) modified these associations.Methods:1100 elderly men from the Normative Aging Study were examined whose lung function (forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1)) was measured every 3 years from 1995 to 2005. The study genotyped theGSTP1Ile105Val and Ala114Val polymorphisms and the (GT)n repeat polymorphism in theHMOX1promoter, classifying repeats as short (n<25) or long (n⩾25). Ambient O3was measured continuously at locations in the Greater Boston area. Mixed linear models were used, adjusting for known confounders.Results:A 15 ppb increase in O3during the previous 48 h was associated with a 1.25% decrease in FEV1(95% CI: −1.96% to −0.54%). This estimated effect was worsened with either the presence of a long (GT)n repeat inHMOX1(−1.38%, 95% CI: −2.11% to −0.65%) or the presence of an allele coding for Val105 inGSTP1(−1.69%, 95% CI: −2.63% to −0.75%). A stronger estimated effect of O3on FEV1was found in subjects carrying both theGSTP1105Val variant and theHMOX1long (GT)n repeat (−1.94%, 95% CI: −2.89% to −0.98%). Similar associations were also found between FVC and O3exposure.Conclusions:Our results suggest that O3has an acute effect on lung function in the elderly, and the effects may be modified by the presence of specific polymorphisms in antioxidant genes.
Molecular characteristics of penicillin-binding protein 2b, 2x, and 1a sequences in penicillin-nonsusceptible Streptococcus pneumoniae isolates in Shenyang, China
Authors: Tian Su Fei , Chu Yun Zhuo , Chen Bai Yi 
Published: June 2008

The aim of this sudy was to investigate the nature of the amino acid motifs found in penicillin-binding proteins (PBP) 2b, 2x, and 1a of penicillin-nonsusceptible Streptococcus pneumoniae isolates from Shenyang, China, and to obtain information regarding the prevalence of alterations within the motifs or in positions flanking the motifs. For 18 clinical isolates comprising 4 penicillin-susceptible S. pneumoniae, 5 penicillin-intermediate S. pneumoniae, and 9 penicillin-resistant S. pneumoniae. the DNA sequences of PBP2b, PBP2x, and PBP1a transpeptidase domains were determined and then genotyped by multilocus sequence typing. Sequence analysis revealed that most penicillin-nonsusceptible S. pneumoniae isolates (penicillin MIC ≥ 1.5 μg/mL and cefotaxime MIC ≥ 2 μg/mL) shared identical PBP2b, PBP2x, and PBP1a amino acid profiles. Most penicillin-resistant S. pneumoniae isolates were ST320 (4-16-19-15-6-20-1), the double-locus variant of the Taiwan19F-14 clone. This study will serve as a basis for future monitoring of genetic changes associated with the emergence and spread of β-lactam resistance in Shenyang, China.
Assessment of microbiological quality of drinking water from household tanks in Bermuda
Authors: Lévesque B. , Pereg D. , Watkinson E. , Maguire J.S. , Bissonnette L. , Gingras S. , Rouja P. , Bergeron M.G. , Dewailly É. 
Published: June 2008

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.
IGF UPTAKE WITH COMPETITIVE BINDING IN ARTICULAR CARTILAGE
Authors: ZHANG LIHAI , GARDINER BRUCE S. , SMITH DAVID W. , PIVONKA PETER , GRODZINSKY ALAN J. 
Published: June 2008

Experiments on the transport of radiolabeled Insulin-like Growth Factors (IGF-I and -II) into bovine articular cartilage show differential uptake depending on the relative proportion of IGF-I and -II. In this study, we present a mathematical model describing both the transport and competition of IGF-I and -II for binding sites represented by two functional groupings of IGF binding proteins (IGFBPs). The first grouping has approximately similar binding affinity to both IGF-I and -II (i.e. IGFBPs 1–5), whereas the second group has significantly higher binding preference for IGF-II compared to IGF-I (i.e. IGFBP-6). Using nonlinear least squares, it is shown that the experimental equilibrium competitive binding results can be described using a reversible Langmuir sorption isotherm involving two dominant IGFBP functional groups.After coupling the sorption model with a poromechanical continuum model, parametric studies are carried out to investigate the effect of model changes including IGF boundary conditions and the ratios of the two IGFBP functional groups. The results show that ignoring competitive binding leads to a significant overestimation of total IGF-I uptake, but an underestimation the rate of "free" (physiologically active) IGF-I within the cartilage. An increase of first group of IGFBPs (i.e. IGFBPs 1–5) as has been reported for osteoarthritis, is observed to hinder the bioavailability of free IGF-I in cartilage, even though the total IGF-I uptake is enhanced. Furthermore, the combination of dynamic compression and competitive binding is seen to enhance the IGF-I uptake within cartilage, but this enhancement is overestimated if competitive binding is neglected.
Reducing Uncertainties of SNO-Estimated Intersatellite AMSU-A Brightness Temperature Biases for Surface-Sensitive Channels
Authors: Iacovazzi Robert A. , Cao Changyong 
Published: June 2008

Abstract
In this study, a technique has been developed to improve collocation of two passive-microwave satellite instrument datasets at a simultaneous nadir overpass (SNO). The technique has been designed for the purpose of reducing uncertainties related to SNO-inferred intersatellite brightness temperature (Tb) biases, and it involves replacing the current “nearest-neighbor pixel matching” collocation technique with quality-controlled bilinear interpolation. Since the largest Tb bias estimation uncertainties of the SNO method are associated with highly variable earth scenes and window channels of microwave radiometers that have relatively large (∼50 km) separation between measurements, the authors have used Advanced Microwave Sounding Unit A (AMSU-A) data to develop the technique. It is found that using the new data collocation technique reduces SNO ensemble mean Tb bias confidence intervals in the SNO method, as applied to surface-sensitive channels of AMSU-A, by nearly 70% on average. This improvement in the SNO method enhances its ability to quantify intersatellite Tb biases at microwave radiometer channels that are sensitive to surface radiation, which is necessary to advance the sciences of numerical weather prediction and climate change detection.