bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Immunodeficiency Virus Type 1 Isolates with the Reverse Transcriptase (RT) Mutation Q145M Retain Nucleoside and Nonnucleoside RT Inhibitor Susceptibility
Authors: Varghese Vici , Mitsuya Yumi , Shahriar Rajin , Bachmann Michael H. , Fessel W. Jeffrey , Kagan Ron M. , Shafer Robert W. 
Published: February 2009

ABSTRACT
Q145M, a mutation in a conserved human immunodeficiency virus type 1 reverse transcriptase (RT) region, was reported to decrease susceptibility to multiple RT inhibitors. We report that Q145M and other Q145 mutations do not emerge with RT inhibitors nor decrease RT inhibitor susceptibility. Q145M should not, therefore, be considered an RT inhibitor resistance mutation.
ST-246 Antiviral Efficacy in a Nonhuman Primate Monkeypox Model: Determination of the Minimal Effective Dose and Human Dose Justification
Authors: Jordan Robert , Goff Arthur , Frimm Annie , Corrado Michael L. , Hensley Lisa E. , Byrd Chelsea M. , Mucker Eric , Shamblin Josh , Bolken Tove' C. , Wlazlowski Carly , Johnson Wendy , Chapman Jennifer , Twenhafel Nancy , Tyavanagimatt Shanthakumar , Amantana Adams , Chinsangaram Jarasvech , Hruby Dennis E. , Huggins John 
Published: February 2009

ABSTRACTTherapeutics for the treatment of pathogenic orthopoxvirus infections are being sought. In the absence of patients with disease, animal models of orthopoxvirus disease are essential for evaluation of the efficacies of antiviral drugs and establishment of the appropriate dose and duration of human therapy. Infection of nonhuman primates (NHP) by the intravenous injection of monkeypox virus has been used to evaluate a promising therapeutic drug candidate, ST-246. ST-246 administered at 3 days postinfection (which corresponds to the secondary viremia stage of disease) at four different doses (from 100 mg/kg of body weight down to 3 mg/kg) once a day for 14 days was able to offer NHP 100% protection from a lethal infection with monkeypox virus and reduce the viral load and lesion formation. In NHP, the administration of ST-246 at a dose of 10 mg/kg/day for 14 days resulted in levels of blood exposure comparable to the levels attained in humans administered 400 mg in the fed state. These results suggest that administration of an oral dosage of 400 mg once daily for 14 days will be effective for the prevention or treatment of smallpox or monkeypox infections in humans.
Intracellular Activity of Antibiotics against
Staphylococcus aureus
in a Mouse Peritonitis Model
Authors: Sandberg Anne , Hessler Jonas H. R. , Skov Robert L. , Blom Jens , Frimodt-Møller Niels 
Published: February 2009

ABSTRACT

Antibiotic treatment of
Staphylococcus aureus
infections is often problematic due to the slow response to therapy and the high frequency of infection recurrence. The intracellular persistence of staphylococci has been recognized and could offer a good explanation for these treatment difficulties. Knowledge of the interplay between intracellular antibiotic activity and the overall outcome of infection is therefore important. Several intracellular in vitro models have been developed, but few experimental animal models have been published. The mouse peritonitis/sepsis model was used as the basic in vivo model exploring a quantitative ex vivo extra- and intracellular differentiation assay. The intracellular presence of
S. aureus
was documented by electron microscopy. Five antibiotics, dicloxacillin, cefuroxime, gentamicin, azithromycin, and rifampin (rifampicin), were tested in the new in vivo model; and the model was able to distinguish between their extra- and intracellular effects. The intracellular effects of the five antibiotics could be ranked as follows as the mean change in the log
10
number of CFU/ml (Δlog
10
CFU/ml) between treated and untreated mice after 4 h of treatment: dicloxacillin (3.70 Δlog
10
CFU/ml) > cefuroxime (3.56 Δlog
10
CFU/ml) > rifampin (1.86 Δlog
10
CFU/ml) > gentamicin (0.61 Δlog
10
CFU/ml) > azithromycin (0.21 Δlog
10
CFU/ml). We could also show that the important factors during testing of intracellular activity in vivo are the size, number, and frequency of doses; the time of exposure; and the timing between the start of infection and treatment. A poor correlation between the intracellular accumulation of the antibiotics and the actual intracellular effect was found. This stresses the importance of performing experimental studies, like those with the new in vivo model described here, to measure actual intracellular activity instead of making predictions based on cellular pharmacokinetic and MICs.
Development of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive and Inducible Expression Systems for
aroA
-Attenuated
Salmonella enterica
Serovar Typhimurium
Authors: Matic Jake N. , Terry Tamsin D. , Van Bockel David , Maddocks Tracy , Tinworth David , Jennings Michael P. , Djordjevic Steven P. , Walker Mark J. 
Published: February 2009

ABSTRACT

Live-vaccine delivery systems expressing two model antigens from
Mycoplasma hyopneumoniae
, F2
P97
(Adh) and NrdF, were constructed using
Salmonella enterica
serovar Typhimurium
aroA
(STM-1), and immunogenicity in mice was evaluated. Recombinant plasmid-based expression (PBE) and chromosomally based expression (CBE) systems were constructed. The PBE system was formed by cloning both antigen genes into pJLA507 to create an operon downstream of temperature-inducible promoters. Constitutive CBE was achieved using a promoter-trapping technique whereby the promoterless operon was stably integrated into the chromosome of STM-1, and the expression of antigens was assessed. The chromosomal position of the operon was mapped in four clones. Inducible CBE was obtained by using the in vivo-induced
sspA
promoter and recombining the expression construct into
aroD
. Dual expression of the antigens was detected in all systems, with PBE producing much larger quantities of both antigens. The stability of antigen expression after in vivo passage was 100% for all CBE strains recovered. PBE and CBE strains were selected for comparison in a vaccination trial. The vaccine strains were delivered orally into mice, and significant systemic immunoglobulin M (IgM) and IgG responses against both antigens were detected among all CBE groups. No significant immune response was detected using PBE strains. Expression of recombinant antigens in
S. enterica
serovar Typhimurium
aroA
from chromosomally located strong promoters without the use of antibiotic resistance markers is a reliable and effective method of inducing a significant immune response.
First
Streptococcus pyogenes
Signature-Tagged Mutagenesis Screen Identifies Novel Virulence Determinants
Authors: Kizy Anne E. , Neely Melody N. 
Published: February 2009

ABSTRACT

The virulence of bacterial pathogens is a complex process that requires the dynamic expression of many genes for the pathogens to invade and circumvent host defenses, as well as to proliferate in vivo. In this study, we employed a large-scale screen, signature-tagged mutagenesis (STM), to identify
Streptococcus pyogenes
virulence genes important for pathogenesis within the host. Approximately 1,200 STM mutants were created and screened using the zebrafish infectious disease model. The transposon insertion site was identified for 29 of the 150 mutants that were considered attenuated for virulence. Previously reported streptococcal virulence genes, such as
mga
,
hasA
,
amrA
,
smeZ
, and two genes in the
sil
locus, were identified, confirming the utility of the model for revealing genes important for virulence. Multiple genes not previously implicated in virulence were also identified, including genes encoding putative transporters, hypothetical cytosolic proteins, and macrolide efflux pumps. The STM mutant strains display various levels of attenuation, and multiple separate insertions were identified in either the same gene or the same locus, suggesting that these factors are important for this type of acute, invasive infection. We further examined two such genes,
silB
and
silC
of a putative quorum-sensing regulon, and determined that they are significant virulence factors in our model of necrotizing fasciitis.
sil
locus promoter expression was examined under various in vitro conditions, as well as in zebrafish tissues, and was found to be differentially induced. This study was a unique investigation of
S. pyogenes
factors required for successful invasive infection.
Concurrent
Helicobacter bilis
Infection in C57BL/6 Mice Attenuates Proinflammatory
H. pylori
-Induced Gastric Pathology
Authors: Lemke Laura B. , Ge Zhongming , Whary Mark T. , Feng Yan , Rogers Arlin B. , Muthupalani Sureshkumar , Fox James G. 
Published: February 2009

ABSTRACT

Because coinfections can alter helicobacter gastritis, we investigated whether enterohepatic
Helicobacter bilis
modulates
Helicobacter pylori
gastritis in C57BL/6 mice. Thirty mice per group were sham dosed,
H. bilis
or
H. pylori
infected, or
H. bilis
infected followed in 2 weeks by
H. pylori
and then evaluated at 6 and 11 months postinfection (mpi) for gastritis and premalignant lesions. Compared to
H. pylori
-infected mice,
H. bilis/H. pylori
-infected mice at 6 and 11 mpi had less severe gastritis, atrophy, mucous metaplasia and hyperplasia (
P
< 0.01) and, additionally, at 11 mpi, less severe intestinal metaplasia and dysplasia (
P
< 0.05).
H. bilis/H. pylori
-infected mice at 11 mpi exhibited less Ki67 labeling of proliferating epithelial cells, reduced numbers of FoxP3
+
T-regulatory (T
REG
) cells, and lower FoxP3
+
mRNA levels than did
H. pylori
-infected mice (
P
< 0.05). Proinflammatory interleukin-1β (IL-1β), gamma interferon, and tumor necrosis factor alpha mRNA levels were attenuated in
H. bilis/H. pylori
-infected mice at 6 and 11 mpi (
P
< 0.01), although anti-inflammatory IL-10, IL-13, and transforming growth factor β1 mRNA levels were not consistently impacted by
H. bilis
coinfection. Decreased pathology in
H. bilis/H. pylori
-infected mice correlated with higher gastric
H. pylori
colonization at 6 mpi (
P
< 0.001) and lower Th1-associated immunoglobulin G2c responses to
H. pylori
at 6 and 10 mpi (
P
< 0.05). We hypothesized that reduced pathology in
H. bilis/H. pylori
-infected mice was due to
H. bilis
-primed T
REG
cells in the lower bowel that migrated to the gastric compartment and inhibited Th1 responses to subsequent
H. pylori
infection. Thus,
H. pylori
-induced gastric lesions may vary in mouse models of unknown enteric helicobacter infection status and, importantly, variable sequelae to human
H. pylori
infection, particularly in developing countries, may occur where coinfection with lower bowel helicobacters and
H. pylori
may be common.
Differential Expression and Glycosylation of
Anaplasma phagocytophilum
Major Surface Protein 2 Paralogs during Cultivation in Sialyl Lewis x-Deficient Host Cells
Authors: Troese Matthew J. , Sarkar Madhubanti , Galloway Nathan L. , Thomas Rachael J. , Kearns Sarah A. , Reneer Dexter V. , Yang Tian , Carlyon Jason A. 
Published: February 2009

ABSTRACT

Many microbial pathogens alter expression and/or posttranslational modifications of their surface proteins in response to dynamics within their host microenvironments to retain optimal interactions with their host cells and/or to evade the humoral immune response.
Anaplasma phagocytophilum
is an intragranulocytic bacterium that utilizes sialyl Lewis x (sLe
x
)-modified P-selectin glycoprotein ligand 1 as a receptor for infecting myeloid cells. Bacterial populations that do not rely on this receptor can be obtained through cultivation in sLe
x
-defective cell lines.
A. phagocytophilum
major surface protein 2 [Msp2(P44)] is encoded by members of a paralogous gene family and is speculated to play roles in host adaptation. We assessed the complement of Msp2(P44) paralogs expressed by
A. phagocytophilum
during infection of sLe
x
-competent HL-60 cells and two HL-60 cell lines defective for sLe
x
expression. Multiple Msp2(P44) and N-terminally truncated 25- to 27-kDa isoforms having various isoelectric points and electrophoretic mobilities were expressed in each cell line. The complement of expressed
msp2
(
p44
) paralogs and the glycosyl residues modifying Msp2(P44) varied considerably among bacterial populations recovered from sLe
x
-competent and -deficient host cells. Thus, loss of host cell sLe
x
expression coincided with both differential expression and glycosylation of
A. phagocytophilum
Msp2(P44). This reinforces the hypothesis that this bacterium is able to generate a large variety of surface-exposed molecules that could provide great antigenic diversity and result in multiple binding properties.
Granulocyte Macrophage Colony-Stimulating Factor Inhibits Breast Cancer Growth and Metastasis by Invoking an Anti-Angiogenic Program in Tumor-Educated Macrophages
Authors: Eubank Tim D. , Roberts Ryan D. , Khan Mahmood , Curry Jennifer M. , Nuovo Gerard J. , Kuppusamy Periannan , Marsh Clay B. 
Published: February 2009

Abstract
Tumor-educated macrophages facilitate tumor metastasis and angiogenesis. We discovered that granulocyte macrophage colony-stimulating factor (GM-CSF) blocked macrophages vascular endothelial growth factor (VEGF) activity by producing soluble VEGF receptor-1 (sVEGFR-1) and determined the effect on tumor-associated macrophage behavior and tumor growth. We show GM-CSF treatment of murine mammary tumors slowed tumor growth and slowed metastasis. These tumors had more macrophages, fewer blood vessels, and lower oxygen concentrations. This effect was sVEGFR-1 dependent. In situ hybridization and flow cytometry identified macrophages as the primary source of sVEGFR-1. These data suggest that GM-CSF can re-educate macrophages to reduce angiogenesis and metastases in murine breast cancer. [Cancer Res 2009;69(5):2133–40]
Identification of Polo-like Kinase 1 as a Potential Therapeutic Target in Anaplastic Thyroid Carcinoma
Authors: Nappi Tito Claudio , Salerno Paolo , Zitzelsberger Horst , Carlomagno Francesca , Salvatore Giuliana , Santoro Massimo 
Published: February 2009

Abstract
Anaplastic thyroid carcinoma (ATC) is one of the most aggressive and chemoresistant cancers. The serine/threonine kinase Polo-like kinase 1 (PLK1), a key regulator of multiple steps during mitotic progression, is highly expressed in ATC. Here, we used the BI 2536 PLK1 inhibitor on ATC and nontransformed thyroid follicular cell lines. Our data show that ATC cells are addicted to high levels of PLK1 activity for proliferation, survival, anchorage-independent growth, and tumorigenicity. On treatment with nanomolar doses of BI 2536, ATC cells progressed normally through S phase but died thereafter, directly from mitotic arrest. Immunofluorescence microscopy, immunoblot, and flow cytometry analysis showed that, on PLK1 blockade, ATC cells arrested in prometaphase with a 4N DNA content. Treated ATC cells accumulated phosphohistone H3 and displayed characteristic mitotic (Polo) spindle aberrations. Nontransformed thyroid cells were 3.2- to 18.4-fold less susceptible to BI 2536–induced cell cycle effects compared with ATC cells. These findings identify PLK1 as a promising target for the molecular therapy of ATC. [Cancer Res 2009;69(5):1916–23]
Lysine-Specific Demethylase 1 Is Strongly Expressed in Poorly Differentiated Neuroblastoma: Implications for Therapy
Authors: Schulte Johannes H. , Lim Soyoung , Schramm Alexander , Friedrichs Nicolaus , Koster Jan , Versteeg Rogier , Ora Ingrid , Pajtler Kristian , Klein-Hitpass Ludger , Kuhfittig-Kulle Steffi , Metzger Eric , Schüle Roland , Eggert Angelika , Buettner Reinhard , Kirfel Jutta 
Published: February 2009

Abstract
Aberrant epigenetic changes in DNA methylation and histone acetylation are hallmarks of most cancers, whereas histone methylation was previously considered to be irreversible and less versatile. Recently, several histone demethylases were identified catalyzing the removal of methyl groups from histone H3 lysine residues and thereby influencing gene expression. Neuroblastomas continue to remain a clinical challenge despite advances in multimodal therapy. Here, we address the functional significance of the chromatin-modifying enzyme lysine-specific demethylase 1 (LSD1) in neuroblastoma. LSD1 expression correlated with adverse outcome and was inversely correlated with differentiation in neuroblastic tumors. Differentiation of neuroblastoma cells resulted in down-regulation of LSD1. Small interfering RNA–mediated knockdown of LSD1 decreased cellular growth, induced expression of differentiation-associated genes, and increased target gene–specific H3K4 methylation. Moreover, LSD1 inhibition using monoamine oxidase inhibitors resulted in an increase of global H3K4 methylation and growth inhibition of neuroblastoma cells in vitro. Finally, targeting LSD1 reduced neuroblastoma xenograft growth in vivo. Here, we provide the first evidence that a histone demethylase, LSD1, is involved in maintaining the undifferentiated, malignant phenotype of neuroblastoma cells. We show that inhibition of LSD1 reprograms the transcriptome of neuroblastoma cells and inhibits neuroblastoma xenograft growth. Our results suggest that targeting histone demethylases may provide a novel option for cancer therapy. [Cancer Res 2009;69(5):2065–71]
LY303511 Enhances TRAIL Sensitivity of SHEP-1 Neuroblastoma Cells via Hydrogen Peroxide–Mediated Mitogen-Activated Protein Kinase Activation and Up-regulation of Death Receptors
Authors: Shenoy Kirthan , Wu Yongfei , Pervaiz Shazib 
Published: February 2009

Abstract
We recently reported that LY294002 (LY29) and LY303511 (LY30) sensitized tumor cells to drug-induced apoptosis independent of the phosphoinositide 3-kinase/Akt pathway. Here, we investigated the mechanism of LY30-induced sensitization of human neuroblastoma cells to TRAIL-mediated apoptosis. We provide evidence that LY30-induced increase in intracellular H2O2 up-regulates the expression of TRAIL receptors (DR4 and DR5) in SHEP-1 cells by activating mitogen-activated protein kinases, resulting in a significant amplification of TRAIL-mediated caspase-8 processing and activity, cytosolic translocation of cytochrome c, and cell death. Involvement of the death receptors was further confirmed by the ability of blocking antibodies against DR4 and/or DR5 to inhibit LY30-induced TRAIL sensitization. Pharmacologic inhibition of c-Jun NH2 terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) activation by SP600125 and PD98059, respectively, blocked LY30-induced increase in sensitization to TRAIL-mediated death. Finally, small interfering RNA–mediated gene silencing of JNK and ERK inhibited LY30-induced increase in surface expression of DR4 and DR5, respectively. These data show that JNK and ERK are two crucial players involved in H2O2-mediated increase in TRAIL sensitization of tumor cells upon exposure to LY30 and underscore a novel mode of action of this inactive analogue of LY29. Our findings could have implications for the use of LY30 and similar compounds for enhancing the apoptotic sensitivity of neuroblastoma cells that often become refractory to chemotherapy. [Cancer Res 2009;69(5):1941–50]
cIAP1, cIAP2, and XIAP Act Cooperatively via Nonredundant Pathways to Regulate Genotoxic Stress–Induced Nuclear Factor-κB Activation
Authors: Jin Hyung-Seung , Lee Dong-Hee , Kim Dong-Hwan , Chung Ji-Hye , Lee Seul-Ji , Lee Tae H. 
Published: February 2009

Abstract
Various genotoxic agents cause monoubiquitination of NEMO/IKKγ—the regulatory subunit of IκB kinase (IKK) complex—in the nucleus. Ubiquitinated NEMO exits from the nucleus and forms a complex with the IKK catalytic subunits IKKα and IKKβ, resulting in IKK activation and, ultimately, nuclear factor-κB (NF-κB) activation. Thus, NEMO ubiquitination is a prerequisite for IKK-dependent activation of NF-κB. However, the IKK activation mechanism is unknown and the NEMO-ubiquitinating E3 enzyme has not been identified. We found that inhibitors of apoptosis protein (IAP) regulate genotoxic stress–induced NF-κB activation at different levels. XIAP mediates activation of the upstream IKK kinase, TAK1, and couples activated TAK1 to the IKK complex. This XIAP-dependent event occurs in response to camptotechin or etoposide/VP16; however, XIAP is dispensable for activation of NF-κB by doxorubicin, which engages a MEK-ERK pathway to activate IKK. We also show that cIAP1 mediates NEMO ubiquitination and cIAP2 regulates an event downstream of NEMO ubiquitination. Our study highlights nonredundant cooperative contributions of IAPs to antiapoptotic NF-κB activation by genotoxic signals beyond their classic caspase inhibitory functions. [Cancer Res 2009;69(5):1782–91]
Xenobiotic Metabolizing Gene Variants, Dietary Heterocyclic Amine Intake, and Risk of Prostate Cancer
Authors: Koutros Stella , Berndt Sonja I. , Sinha Rashmi , Ma Xiaomei , Chatterjee Nilanjan , Alavanja Michael C.R. , Zheng Tongzhang , Huang Wen-Yi , Hayes Richard B. , Cross Amanda J. 
Published: February 2009

Abstract
We recently reported that heterocyclic amines (HCA) are associated with prostate cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. We now use extensive genetic data from this resource to determine if risks associated with dietary HCAs {2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); 2-amino-3,8-dimethylimidazo[4,5-b]quinoxaline (MeIQx); and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx)} from cooked meat are modified by single nucleotide polymorphisms (SNP) in genes involved in HCA metabolism (CYP1A1, CYP1A2, CYP1B1, GSTA1, GSTM1, GSTM3, GSTP1, NAT1, NAT2, SULT1A1, SULT1A2, and UGT1A locus). We conducted a nested case-control study that included 1,126 prostate cancer cases and 1,127 controls selected for a genome-wide association study for prostate cancer. Unconditional logistic regression was used to estimate odds ratios (OR), 95% confidence intervals (95% CI), and P values for the interaction between SNPs, HCA intake, and risk of prostate cancer. The strongest evidence for an interaction was noted between DiMeIQx and MeIQx and the polymorphism rs11102001 downstream of the GSTM3 locus (Pinteraction = 0.001 for both HCAs; statistically significant after correction for multiple testing). Among men carrying the A variant, the risk of prostate cancer associated with high DiMeIQx intake was 2-fold greater than that with low intake (OR, 2.3; 95% CI, 1.2–4.7). The SNP rs11102001, which encodes a nonsynonymous amino acid change P356S in EPS8L3, is a potential candidate modifier of the effect of HCAs on prostate cancer risk. The observed effect provides evidence to support the hypothesis that HCAs may act as promoters of malignant transformation by altering mitogenic signaling. [Cancer Res 2009;69(5):1877–84]