bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation of
Bartonella vinsonii
subsp.
berkhoffii
Genotype II from a Boy with Epithelioid Hemangioendothelioma and a Dog with Hemangiopericytoma
Authors: Breitschwerdt Edward B. , Maggi Ricardo G. , Varanat Mrudula , Linder Keith E. , Weinberg Guy 
Published: April 2009

ABSTRACT

In this report, we describe isolation of
Bartonella vinsonii
subsp.
berkhoffii
genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma. These results suggest that
B
.
vinsonii
subsp.
berkhoffii
may cause vasoproliferative lesions in both humans and dogs.
Comparison of the Bactec 9240 and BacT/Alert Blood Culture Systems for Evaluation of Placental Cord Blood for Transfusion in Neonates
Authors: Riedel Stefan , Junkins Alan , Stamper Paul D. , Cress Gretchen , Widness John A. , Doern Gary V. 
Published: April 2009

ABSTRACT

The Bactec 9240 and the BacT/Alert blood culture systems were compared as a means for detection of bacterial contaminants in whole blood, concentrated red cells, and plasma preparations prepared from umbilical cord blood (UCB) samples. Ninety-two UCB units seeded with low levels of various bacteria were evaluated. In more than 50% of cases, growth was not detected in plasma using either system (
P
< 0.001). When concentrated red cells and whole blood were compared, the Bactec system detected bacterial growth consistently sooner than the BacT/Alert system in all seeded bacteria except
Staphylococcus
species in whole blood. The median lengths of time to detection (LTD) for whole blood and concentrated cells in BacT/Alert were 18.7 h and 18.5 h, respectively. The median LTD for the same blood fractions using the Bactec system were 16.05 h and 15.64 h. These differences in LTD by blood culture system and sample type were statistically significant (whole blood,
P
= 0.0449; concentrated cells,
P
= 0.0037). Based on the results of our study, we recommend the use of either concentrated red cells or whole blood for sterility testing in UCB samples. In our laboratory, the Bactec system compared to the BacT/Alert system was the superior method for rapid detection of bacterial contaminants in cord blood.
First Report of
Tsukamurella
Keratitis: Association between
T. tyrosinosolvens
and
T. pulmonis
and Ophthalmologic Infections
Authors: Woo Patrick C. Y. , Fong Angie H. C. , Ngan Antonio H. Y. , Tam Dorothy M. W. , Teng Jade L. L. , Lau Susanna K. P. , Yuen Kwok-Yung 
Published: April 2009

ABSTRACT

We describe the first two cases of
Tsukamurella
keratitis, presented as eye pain with or without blurring of vision. One case was associated with trichiasis and the other with contact lens wear. The two isolates were identified as
T. tyrosinosolvens
and
T. pulmonis
, respectively, by phenotypic characterization and 16S rRNA sequencing.
Peptide Nucleic Acid-Based Array for Detecting and Genotyping Human Papillomaviruses
Authors: Choi Jae-jin , Kim Chunhee , Park Heekyung 
Published: April 2009

ABSTRACT
We describe a novel array for accurate and reliable genotyping of human papillomavirus (HPV) using peptide nucleic acid (PNA) probes. In order to exploit the superior hybridization properties of PNA with target HPV DNAs, we developed a novel PNA array (PANArray HPV). PANArray HPV enables the detection and genotyping of HPVs using 32 type-specific PNA capture probes for medically important HPVs. All tested HPV types showed highly unique hybridization patterns with type-specific PNA probes. PNA array results showed stable specificities and sensitivities after up to 13 months of storage at room temperature. Also, we demonstrated the superior specificity, sensitivity, and stability of PNA arrays for HPV genotyping. We compared the genotyping results of the PNA array to sequencing with MY09/11 PCR products derived from 72 clinical samples. The results showed excellent agreement between the PNA array and sequencing, except for samples reflecting multiple infections. The results from the PNA array were compared with those of type-specific PCR when discrepant results occurred owing to multiple infections. The results for the PNA array matched those of type-specific PCR in all cases. Newly developed PNA arrays show excellent specificity and sensitivity and long shelf life. Our results suggest that the PNA array represents a reliable alternative to conventional DNA arrays for HPV genotyping, as well as for diagnostics.
Ureaplasma parvum
as a Cause of Sternal Wound Infection
Authors: Walkty Andrew , Lo Evelyn , Manickam Kanchana , Alfa Michelle , Xiao Li , Waites Ken 
Published: April 2009

ABSTRACT

Few reports in the literature have documented the isolation of
Ureaplasma
species from sternal wounds. A case of sternal wound infection likely due to
Ureaplasma parvum
is described. When routine bacterial cultures from a sternal wound infection fail to yield a pathogen, diagnostic testing for mycoplasmas and ureaplasmas should be considered.
Evaluation of the BD GeneOhm StaphSR Assay for Detection of Methicillin-Resistant and Methicillin-Susceptible
Staphylococcus aureus
Isolates from Spiked Positive Blood Culture Bottles
Authors: Gröbner Sabine , Dion Mireille , Plante Mélanie , Kempf Volkhard A. J. 
Published: April 2009

ABSTRACT

To improve the clinical outcome of
Staphylococcus aureus
septicemia, the early selection of appropriate antibiotic treatment is crucial. Molecular diagnostics represents an attractive approach for the rapid identification of
S. aureus
and the determination of its methicillin (meticillin) resistance. In direct comparison to other molecular assays (
sa442
and
mecA
real-time PCRs) and standard laboratory procedures, we evaluated the BD GeneOhm StaphSR assay for its use in the detection of
S. aureus
and methicillin-resistant
S. aureus
(MRSA) from spiked blood culture bottles (
n
= 134). In the case of detecting
S. aureus
(
n
= 90; for methicillin-susceptible
S. aureus
,
n
= 45; for MRSA,
n
= 45), the BD GeneOhm StaphSR assay had a sensitivity and a specificity of 100% each (95% confidence intervals [CIs], 96.0 to 100% and 82.4 to 100%, respectively). For MRSA (
n
= 45), the test was 95.6% (95% CI, 84.9 to 99.5%) sensitive and 95.3% (95% CI, 86.9 to 99.0%) specific. Overall, five discrepant results arose with this assay due to the presence of methicillin-susceptible, revertant MRSA strains (3/45) and MRSA strains that were not detected by the BD GeneOhm StaphSR assay (2/45). Compared to other real-time PCR-based molecular approaches and to conventional standard laboratory methods, the BD GeneOhm StaphSR turned out to be an appropriate diagnostic tool for a rapid (∼1.5 h), preliminary identification of
S. aureus
and MRSA from blood cultures.
Cell Cycle Control of Kaposi's Sarcoma-Associated Herpesvirus Latency Transcription by CTCF-Cohesin Interactions
Authors: Kang Hyojeung , Lieberman Paul M. 
Published: April 2009

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) latency is characterized by the highly regulated transcription of a few viral genes essential for genome maintenance and host cell survival. A major latency control region has been identified upstream of the divergent promoters for the multicistronic transcripts encoding LANA (ORF73), vCyclin (ORF72), and vFLIP (ORF71) and for the complementary strand transcript encoding K14 and vGPCR (ORF74). Previous studies have shown that this major latency control region is occupied by the cellular chromatin boundary factor CTCF and chromosome structural maintenance proteins SMC1, SMC3, and RAD21, which comprise the cohesin complex. Deletion of the CTCF-cohesin binding site caused an inhibition of cell growth and viral genome instability. We now show that the KSHV genes regulated by CTCF-cohesin are under cell cycle control and that mutation of the CTCF binding sites abolished cell cycle-regulated transcription. Cohesin subunits assembled at the CTCF binding sites and bound CTCF proteins in a cell cycle-dependent manner. Subcellular distribution of CTCF and colocalization with cohesins also varied across the cell cycle. Ectopic expression of Rad21 repressed CTCF-regulated transcription of KSHV lytic genes, and a Rad21-CTCF chimeric protein converted CTCF into an efficient transcriptional repressor of KSHV genes normally activated in the G
2
phase. We conclude that cohesins interact with CTCF in mid-S phase and repress CTCF-regulated genes in a cell cycle-dependent manner. We propose that the CTCF-cohesin complex plays a critical role in regulating the cell cycle control of viral gene expression during latency and that failure to maintain cell cycle control of latent transcripts inhibits host cell proliferation and survival.
Breaking Human Cytomegalovirus Major Immediate-Early Gene Silence by Vasoactive Intestinal Peptide Stimulation of the Protein Kinase A-CREB-TORC2 Signaling Cascade in Human Pluripotent Embryonal NTera2 Cells
Authors: Yuan Jinxiang , Liu Xiaoqiu , Wu Allen W. , McGonagill Patrick W. , Keller Michael J. , Galle Courtney S. , Meier Jeffery L. 
Published: April 2009

ABSTRACTThe triggering mechanisms underlying reactivation of human cytomegalovirus (HCMV) in latently infected persons are unclear. During latency, HCMV major immediate-early (MIE) gene expression breaks silence to initiate viral reactivation. Using quiescently HCMV-infected human pluripotent embryonal NTera2 cells (NT2) to model HCMV reactivation, we show that vasoactive intestinal peptide (VIP), an immunomodulatory neuropeptide, immediately and dose-dependently (1 to 500 nM) activates HCMV MIE gene expression. This response requires the MIE enhancer cyclic AMP response elements (CRE). VIP quickly elevates CREB Ser133 and ATF-1 Ser63 phosphorylation levels, although the CREB Ser133 phosphorylation level is substantial at baseline. VIP does not change the level of HCMV genomes in nuclei, Oct4 (pluripotent cell marker), or hDaxx (cellular repressor of HCMV gene expression). VIP-activated MIE gene expression is mediated by cellular protein kinase A (PKA), CREB, and TORC2. VIP induces PKA-dependent TORC2 Ser171 dephosphorylation and nuclear entry, which likely enables MIE gene activation, as TORC2 S171A (devoid of Ser171 phosphorylation) exhibits enhanced nuclear entry and desilences the MIE genes in the absence of VIP stimulation. In conclusion, VIP stimulation of the PKA-CREB-TORC2 signaling cascade activates HCMV CRE-dependent MIE gene expression in quiescently infected NT2 cells. We speculate that neurohormonal stimulation via this signaling cascade is a possible means for reversing HCMV silence in vivo.
Herpes Simplex Virus Type 1 Suppresses RNA-Induced Gene Silencing in Mammalian Cells
Authors: Wu Zetang , Zhu Yali , Bisaro David M. , Parris Deborah S. 
Published: April 2009

ABSTRACT
RNA-induced silencing is a potent innate antiviral defense strategy in plants, and suppression of silencing is a hallmark of pathogenic plant viruses. However, the impact of silencing as a mammalian antiviral defense mechanism and the ability of mammalian viruses to suppress silencing in natural host cells have remained controversial. The ability of herpes simplex virus type 1 (HSV-1) to suppress silencing was examined in a transient expression system that employed an imperfect hairpin to target degradation of transcripts encoding enhanced green fluorescent protein (EGFP). HSV-1 infection suppressed EGFP-specific silencing as demonstrated by increased EGFP mRNA levels and an increase in the EGFP mRNA half-life. The increase in EGFP mRNA stability occurred despite the well-characterized host macromolecular shutoff functions of HSV-1 that globally destabilize mRNAs. Moreover, mutant viruses defective in these functions increased the stability of EGFP mRNA even more than did the wild-type virus in silenced cells compared to results in control cells. The importance of RNA silencing to HSV-1 replication was confirmed by a significantly enhanced virus burst size in cells in which silencing was knocked down with small inhibitory RNAs directed to Argonaute 2, an integral component of the silencing complex. Given that HSV-1 encodes several microRNAs, it is possible that a dynamic equilibrium exists between silencing and silencing suppression that is capable of modulating viral gene expression to promote replication, to evade host defenses, and/or to promote latency.
Cytotoxic-T-Lymphocyte-Mediated Elimination of Target Cells Transduced with Engineered Adeno-Associated Virus Type 2 Vector In Vivo
Authors: Li Chengwen , Hirsch Matt , DiPrimio Nina , Asokan Aravind , Goudy Kevin , Tisch Roland , Samulski R. Jude 
Published: April 2009

ABSTRACT

A recent clinical trial in patients with hemophilia B has suggested that adeno-associated virus (AAV) capsid-specific cytotoxic T lymphocytes (CTLs) eliminated AAV-transduced hepatocytes and resulted in therapeutic failure. AAV capsids elicit a CTL response in animal models; however, these capsid-specific CTLs fail to kill AAV-transduced target cells in mice. To better model the human clinical trial data in mice, we introduced an immunodominant epitope derived from ovalbumin (OVA; SIINFEKL) into the AAV capsid and tested CTL-mediated killing of AAV2-transduced target tissues in vivo. Initially, in vitro experiments demonstrated both classical class I and cross-presentation of the OVA antigen, following endogenous expression or AAV2-OVA vector transduction, respectively. Furthermore, an OVA-specific CTL response was elicited after muscular or systemic injection of the AAV2-OVA vector. Finally, CTL reactivity was enhanced in mice with established SIINFEKL-specific immunity after AAV2-OVA/α1 anti-trypsin (AAT) administration. Most importantly, these OVA-specific CTLs decreased AAT expression in mice treated with AAV2-OVA/AAT vector that followed a time course mimicking uncoating kinetics of AAV2 transduction in OVA-immunized mice. These results demonstrate that AAV capsid-derived antigens elicit CD8
+
CTL reactivity, and these CTLs eliminated AAV-transduced target cells in mice. Notably, this model system can be exploited to study the kinetics of capsid presentation from different serotypes of AAV and permit the design of novel strategies to block CTL-mediated killing of AAV-transduced cells.
Herpes Simplex Virus Glycoprotein B Associates with Target Membranes via Its Fusion Loops
Authors: Hannah Brian P. , Cairns Tina M. , Bender Florent C. , Whitbeck J. Charles , Lou Huan , Eisenberg Roselyn J. , Cohen Gary H. 
Published: April 2009

ABSTRACT
Herpes simplex virus (HSV) glycoproteins gB, gD, and gH/gL are necessary and sufficient for virus entry into cells. Structural features of gB are similar to those of vesicular stomatitis virus G and baculovirus gp64, and together they define the new class III group of fusion proteins. Previously, we used mutagenesis to show that three hydrophobic residues (W174, Y179, and A261) within the putative gB fusion loops are integral to gB function. Here we expanded our analysis, using site-directed mutagenesis of each residue in both gB fusion loops. Mutation of most of the nonpolar or hydrophobic amino acids (W174, F175, G176, Y179, and A261) had severe effects on gB function in cell-cell fusion and null virus complementation assays. Of the six charged amino acids, mutation of H263 or R264 also negatively affected gB function. To further analyze the mutants, we cloned the ectodomains of the W174R, Y179S, H263A, and R264A mutants into a baculovirus expression system and compared them with the wild-type (WT) form, gB730t. As shown previously, gB730t blocks virus entry into cells, suggesting that gB730t competes with virion gB for a cell receptor. All four mutant proteins retained this function, implying that fusion loop activity is separate from gB-receptor binding. However, unlike WT gB730t, the mutant proteins displayed reduced binding to cells and were either impaired or unable to bind naked, cholesterol-enriched liposomes, suggesting that it may be gB-lipid binding that is disrupted by the mutations. Furthermore, monoclonal antibodies with epitopes proximal to the fusion loops abrogated gB-liposome binding. Taken together, our data suggest that gB associates with lipid membranes via a fusion domain of key hydrophobic and hydrophilic residues and that this domain associates with lipid membranes during fusion.
Kaposi's Sarcoma-Associated Herpesvirus RTA Promotes Degradation of the Hey1 Repressor Protein through the Ubiquitin Proteasome Pathway
Authors: Gould Faye , Harrison Sally M. , Hewitt Eric W. , Whitehouse Adrian 
Published: April 2009

ABSTRACT
The Kaposi's sarcoma-associated herpesvirus (KSHV) replication and transcription activator (RTA) protein regulates the latent-lytic switch by transactivating a variety of KSHV lytic and cellular promoters. RTA is a novel E3 ubiquitin ligase that targets a number of transcriptional repressor proteins for degradation by the ubiquitin proteasome pathway. Herein, we show that RTA interacts with the cellular transcriptional repressor protein Hey1. We demonstrate that Hey1 is a target for RTA-mediated ubiquitination and is subsequently degraded by the proteasome. Moreover, a Cys-plus-His-rich region within RTA is important for RTA-mediated degradation of Hey1. We confirm that Hey1 represses the RTA promoter and, furthermore, show that Hey1 binds to the RTA promoter. An interaction was observed between Hey1 and the corepressor mSin3A, and this interaction was abolished in the presence of RTA. Additionally, mSin3A associated with the RTA promoter in nonreactivated, but not reactivated, BCBL1 cells. Small interfering RNA knockdown of Hey1 in HEK 293T cells latently infected with the recombinant virus rKSHV.219 led to increased levels of RTA expression upon reactivation but was insufficient to induce complete lytic reactivation. These results suggest that other additional transcriptional repressors are also important in maintenance of KSHV latency. Taken together, our results suggest that Hey1 has a contributory role in the maintenance of KSHV latency and that disruption of the Hey1 repressosome by RTA-targeted degradation may be one step in the mechanism to regulate lytic reactivation.
Human Immunodeficiency Virus Integration Efficiency and Site Selection in Quiescent CD4
+
T Cells
Authors: Vatakis Dimitrios N. , Kim Sanggu , Kim Namshin , Chow Samson A. , Zack Jerome A. 
Published: April 2009

ABSTRACT

Until very recently, quiescent CD4
+
T cells were thought to be resistant to human immunodeficiency virus (HIV) infection. Subsequent studies, attempting to fully elucidate the mechanisms of resistance, showed that quiescent cells could become infected by HIV at low efficiency and form a latently infected population. In this study, we set out to identify the sites of viral integration and to assess the efficiency of the overall integration process in quiescent cells. Based on our results, HIV integration in quiescent CD4
+
T cells occurs in sites similar to those of their prestimulated counterparts. While site selections are similar, the integration process in quiescent cells is plagued by the formation of high levels of incorrectly processed viral ends and abortive two-long-terminal-repeat circles.
The Cellular RNA Export Receptor TAP/NXF1 Is Required for ICP27-Mediated Export of Herpes Simplex Virus 1 RNA, but the TREX Complex Adaptor Protein Aly/REF Appears To Be Dispensable
Authors: Johnson Lisa A. , Li Ling , Sandri-Goldin Rozanne M. 
Published: April 2009

ABSTRACT

Herpes simplex virus 1 (HSV-1) protein ICP27 has been shown to shuttle between the nucleus and cytoplasm and to bind viral RNA during infection. ICP27 was found to interact with the cellular RNA export adaptor protein Aly/REF, which is part of the TREX complex, and to relocalize Aly/REF to viral replication sites. ICP27 is exported to the cytoplasm through the export receptor TAP/NXF1, and ICP27 must be able to interact with TAP/NXF1 for efficient export of HSV-1 early and late transcripts. We examined the dynamics of ICP27 movement and its localization with respect to Aly/REF and TAP/NXF1 in living cells during viral infection. Recombinant viruses with a yellow fluorescent protein (YFP) tag on the N or C terminus of ICP27 were constructed. While the N-terminally tagged ICP27 virus behaved like wild-type HSV-1, the C-terminally tagged virus was defective in viral replication and gene expression, and ICP27 was confined to the nucleus, suggesting that the C-terminal YFP tag interfered with ICP27's C-terminal interactions, including the interaction with TAP/NXF1. To assess the role of Aly/REF and TAP/NXF1 in viral RNA export, these factors were knocked down using small interfering RNA. Knockdown of Aly/REF had little effect on the export of ICP27 or poly(A)
+
RNA during infection. In contrast, a decrease in TAP/NXF1 levels severely impaired export of ICP27 and poly(A)
+
RNA. We conclude that TAP/NXF1 is essential for ICP27-mediated export of RNA during HSV-1 infection, whereas Aly/REF may be dispensable.
Kinetic Dependence of Paramyxovirus Entry Inhibition
Authors: Porotto Matteo , Yokoyama Christine C. , Orefice Gianmarco , Kim Han-Sung , Aljofan Mohamed , Mungall Bruce A. , Moscona Anne 
Published: April 2009

ABSTRACT
Peptides derived from conserved heptad repeat (HR) regions of paramyxovirus fusion (F) proteins inhibit viral fusion by interfering with the formation of the fusogenic six-helix bundle structure. Peptide efficacy is affected by the strength of the peptide association with the target virus's complementary HR region. Here, we show that a second basis for peptide efficacy lies in the kinetics of F activation by the homotypic attachment protein: efficient F activation by the attachment protein shortens the period during which antiviral molecules targeting intermediate states of F may act, thereby modulating the effectiveness of inhibitory peptides. These results highlight new issues to be considered in developing strategies for fusion inhibitors.
Identification of Cellular Genes Affecting the Infectivity of Foot-and-Mouth Disease Virus
Authors: Piccone Maria E. , Feng Yanan , Chang Annie C. Y. , Mosseri Ronen , Lu Quan , Kutish Gerald F. , Lu Zhiqiang , Burrage Thomas G. , Gooch Christina , Rock Daniel L. , Cohen Stanley N. 
Published: April 2009

ABSTRACTFoot-and-mouth disease virus (FMDV) produces one of the most infectious of all livestock diseases, causing extensive economic loss in areas of breakout. Like other viral pathogens, FMDV recruits proteins encoded by host cell genes to accomplish the entry, replication, and release of infectious viral particles. To identify such host-encoded proteins, we employed an antisense RNA strategy and a lentivirus-based library containing approximately 40,000 human expressed sequence tags (ESTs) to randomly inactivate chromosomal genes in a bovine kidney cell line (LF-BK) that is highly susceptible to FMDV infection and then isolated clones that survived multiple rounds of exposure to the virus. Here, we report the identification of ESTs whose expression in antisense orientation limited host cell killing by FMDV and restricted viral propagation. The role of one such EST, that of ectonucleoside triphosphate diphosphohydrolase 6 (NTPDase6; also known as CD39L2), a membrane-associated ectonucleoside triphosphate diphosphohydrolase that previously was not suspected of involvement in the propagation of viral pathogens and which we now show is required for normal synthesis of FMDV RNA and proteins, is described in this report.