bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Silencer Element in the Bovine Papillomavirus Type 4 Promoter Represses the Transcriptional Response to Papillomavirus E2 Protein
Authors: Vance Keith W. , Campo M. Saveria , Morgan Iain M. 
Published: July 2002

ABSTRACT

The long control regions (LCRs) of mucosal epitheliotropic papillomaviruses have similar organizations: a promoter region, an enhancer region, and a highly conserved distribution of E2 DNA binding sites (C. Desaintes and C. Demeret, Semin. Cancer Biol. 7:339–347, 1996). The enhancer of these viruses is epithelial cell specific, as it fails to activate transcription from heterologous promoters in nonepithelial cell types (B. Gloss, H. U. Bernard, K. Seedorf, and G. Klock, EMBO J. 6:3735–3743, 1987). Using the bovine papillomavirus type 4 (BPV-4) LCR and a bovine primary cell system, we have shown previously that a level of epithelial specificity resides in a papillomavirus promoter region. The BPV-4 promoter shows an enhanced response to transcriptional activators in epithelial cells compared with that of fibroblasts (K. W. Vance, M. S. Campo, and I. M. Morgan, J. Biol. Chem. 274:27839–27844, 1999). A chimeric lcr/tk promoter suggests that the upstream BPV-4 promoter region determines the cell-type-selective response of this promoter in fibroblasts and keratinocytes. Promoter deletion analysis identified two novel repressor elements that are, at least in part, responsible for mediating the differential response of this promoter to upstream activators in fibroblasts and keratinocytes. One of these elements, promoter repressor element 2 (PRE-2), is conserved in position and sequence in the related mucosal epitheliotropic papillomaviruses, BPV-3 and BPV-6. PRE-2 functions in
cis
to repress the basal activity of the simian virus 40 promoter and binds a specific protein complex. We identify the exact nucleotides necessary for binding and correlate loss of binding with loss of transcriptional repression. We also incorporate these mutations into the BPV-4 promoter and demonstrate an enhanced response of the mutated promoter to E2 in fibroblasts. The DNA binding protein in the detected complex is shown to have a molecular mass of approximately 50 kDa. The PRE-2 binding protein represents a novel transcriptional repressor and regulator of papillomavirus transcription.
Arbovirus of Marine Mammals: a New Alphavirus Isolated from the Elephant Seal Louse,
Lepidophthirus macrorhini
Authors: La Linn May , Gardner Joy , Warrilow David , Darnell Grant A. , McMahon Clive R. , Field Ian , Hyatt Alex D. , Slade Robert W. , Suhrbier Andreas 
Published: July 2002

ABSTRACT

A novel alphavirus was isolated from the louse
Lepidophthirus macrorhini
, collected from southern elephant seals,
Mirounga leonina
, on Macquarie Island, Australia. The virus displayed classic alphavirus ultrastructure and appeared to be serologically different from known Australasian alphaviruses. Nearly all Macquarie Island elephant seals tested had neutralizing antibodies against the virus, but no virus-associated pathology has been identified. Antarctic Division personnel who have worked extensively with elephant seals showed no serological evidence of exposure to the virus. Sequence analysis illustrated that the southern elephant seal (SES) virus segregates with the Semliki Forest group of Australasian alphaviruses. Phylogenetic analysis of known alphaviruses suggests that alphaviruses might be grouped according to their enzootic vertebrate host class. The SES virus represents the first arbovirus of marine mammals and illustrates that alphaviruses can inhabit Antarctica and that alphaviruses can be transmitted by lice.
Multiple eIF4GI-Specific Protease Activities Present in Uninfected and Poliovirus-Infected Cells
Authors: Zamora Miguel , Marissen Wilfred E. , Lloyd Richard E. 
Published: July 2002

ABSTRACT

Cleavage of eukaryotic translation initiation factor 4GI (eIF4GI) is required for shutoff of host cell translation during poliovirus (PV) infection of HeLa cells. Reports published by several groups have led to confusion whether this cleavage is mediated by viral 2A protease (2A
pro
) or a putative cellular enzyme (termed eIF4Gase) which is activated by 2A
pro
or other aspects of viral infection. Here we have further investigated eIF4Gase activities in PV-infected cells. Column purification of eIF4GI cleavage activity separated two activities which generated N-terminal cleavage products of different lengths. Both activities were detected using either native eIF4G or radiolabeled recombinant eIF4G as the substrate. Analysis of cleavage products formed by each activity on native and mutant substrates suggests that one activity cleaves eIF4G1 at or very near the 2A
pro
cleavage site and the other activity cleaves approximately 40 residues upstream of the 2A
pro
cleavage site. When PV infections in HeLa cells were supplemented with 2 mM guanidine, which indirectly limits expression of 2A
pro
, two distinct C-terminal cleavage fragments of eIF4GI were detected. These C-terminal cleavage fragments of eIF4GI were purified from infected cells, and a new eIF4GI cleavage site was mapped to a unique site 43 amino acids upstream of the known 2A
pro
cleavage site. Further, eIF4GI cleavage in vivo could be blocked by addition of zVAD to PV-guanidine infections. zVAD is a broad-spectrum caspase inhibitor which had no effect on 2A
pro
cleavage activity or PV polyprotein processing. Lastly, similar types of eIF4Gase cleavage activities were also detected in uninfected cells under various conditions, including early apoptosis or during cell cycle transit. The data suggest that the same types of eIF4GI cleavage activities which are generated in PV-infected cells can also be generated in the absence of virus. Taken together, the data support a model in which multiple cellular activities process eIF4GI in PV-infected cells, in addition to 2A
pro
.
Vaccine-Induced Immune Responses in Rodents and Nonhuman Primates by Use of a Humanized Human Immunodeficiency Virus Type 1
pol
Gene
Authors: Casimiro Danilo R. , Tang Aimin , Perry Helen C. , Long Romnie S. , Chen Minchun , Heidecker Gwendolyn J. , Davies Mary-Ellen , Freed Daniel C. , Persaud Natasha V. , Dubey Sheri , Smith Jeffrey G. , Havlir Diane , Richman Douglas , Chastain Michael A. , Simon Adam J. , Fu Tong-Ming , Emini Emilio A. , Shiver John W. 
Published: July 2002

ABSTRACT

A synthetic gene consisting of the reverse transcriptase (RT) and integrase (IN) domains of human immunodeficiency virus type 1 (HIV-1)
pol
was constructed using codons most frequently used in humans. The humanized
pol
gave dramatically improved levels of Rev-independent, in vitro protein production in mammalian cells and elicited much stronger cellular immunity in rodents than did virus-derived gene. Specifically, BALB/c mice were immunized with plasmids and/or recombinant vaccinia virus constructs expressing the synthetic gene. High frequencies of Pol-specific T lymphocytes were detected in these animals by the gamma interferon enzyme-linked immunospot assay against pools of short overlapping peptides. Characterization of the stimulatory peptides from these pools indicates that the optimized gene constructs are able to effectively activate both CD4
+
and CD8
+
T cells. Immunization of rhesus macaques with DNA vaccines expressing the humanized
pol
coupled to a human tissue plasminogen activator leader sequence led to pronounced in vitro cytotoxic T-lymphocyte killing activities and enhanced levels of circulating Pol-specific T cells, comparable to those observed in HIV-1-infected human subjects. Thus, optimizing the immunogenic properties of HIV-1 Pol at the level of the gene sequence validates it as an antigen and provides an important step toward the construction of a potent
pol
-based HIV-1 vaccine component.
DNA Cleavage and Packaging Proteins Encoded by Genes U
L
28, U
L
15, and U
L
33 of Herpes Simplex Virus Type 1 Form a Complex in Infected Cells
Authors: Beard Philippa M. , Taus Naomi S. , Baines Joel D. 
Published: July 2002

ABSTRACT

Previous studies have indicated that the U
L
6, U
L
15, U
L
17, U
L
28, U
L
32, and U
L
33 genes are required for the cleavage and packaging of herpes simplex viral DNA. To identify proteins that interact with the U
L
28-encoded DNA binding protein of herpes simplex virus type 1 (HSV-1), a previously undescribed rabbit polyclonal antibody directed against the U
L
28 protein fused to glutathione
S
-transferase was used to immunopurify U
L
28 and the proteins with which it associated. It was found that the antibody specifically coimmunoprecipitated proteins encoded by the genes U
L
28, U
L
15, and U
L
33 from lysates of both HEp-2 cells infected with HSV-1(F) and insect cells infected with recombinant baculoviruses expressing these three proteins. In reciprocal reactions, antibodies directed against the U
L
15- or U
L
33-encoded proteins also coimmunoprecipitated the U
L
28 protein. The coimmunoprecipitation of the three proteins from HSV-infected cells confirms earlier reports of an association between the U
L
28 and U
L
15 proteins and represents the first evidence of the involvement of the U
L
33 protein in this complex.
HLA-Cw*04
and Hepatitis C Virus Persistence
Authors: Thio Chloe L. , Gao Xiaojiang , Goedert James J. , Vlahov David , Nelson Kenrad E. , Hilgartner Margaret W. , O'Brien Stephen J. , Karacki Peter , Astemborski Jacquie , Carrington Mary , Thomas David L. 
Published: July 2002

ABSTRACT

In studies of acute hepatitis C virus (HCV) infection, the early host immune response is one of the determinants of viral persistence. The class I human leukocyte antigens (HLA), which present foreign antigen to cytolytic T cells, are integral components of this response. We hypothesized that the highly polymorphic
HLA
genes affect the outcome of an HCV infection. To test this hypothesis, we molecularly typed 231 persons with well-documented clearance of an HCV infection and 444 matched persistently infected persons.
HLA-A*1101
(odds ratio [OR], 0.49; 95% confidence interval [95% CI], 0.27 to 0.89),
HLA-B*57
(OR, 0.62; 95% CI, 0.39 to 1.00), and
HLA-Cw*0102
(OR, 0.43; 95% CI, 0.21 to 0.89) were associated with viral clearance, whereas
HLA-A*2301
(OR, 1.78; 95% CI, 1.01 to 3.11) and
HLA-Cw*04
(OR, 1.78; 95% CI, 1.21 to 2.59) were associated with viral persistence.
HLA-Cw*04
is in strong linkage disequilibrium with
HLA-B*53
and
HLA-B*35
, but only
HLA-B*53
(OR, 1.70; 95% CI, 0.95 to 3.06) and the
Cw*04-B*53
haplotype (OR, 1.76; 95% CI, 0.94 to 3.26) were weakly associated with viral persistence.
HLA-B*53
has similar, but not necessarily identical, binding specificity to some
HLA-B*35
subtypes (
B*35-Px
group). The association with the
B*35-Px
group was less strong than with
HLA-B*53
alone. The association of
HLA-Cw*04
with HCV persistence was codominant (two copies of the gene were more strongly associated with persistence than one copy). However,
HLA-Cw*04
was not associated with HCV RNA levels among the persistently infected individuals. Since Cw*04 is a ligand for the killer immunoglobulin-like receptors on natural killer cells, these cells may be involved in recovery from HCV infection. Further investigation is needed to understand the relationship between class I alleles and HCV clearance.
Human Immunodeficiency Virus Type 1 Neutralization Measured by Flow Cytometric Quantitation of Single-Round Infection of Primary Human T Cells
Authors: Mascola John R. , Louder Mark K. , Winter Christine , Prabhakara Ranjani , De Rosa Stephen C. , Douek Daniel C. , Hill Brenna J. , Gabuzda Dana , Roederer Mario 
Published: July 2002

ABSTRACT

There is currently intensive research on the design of novel human immunodeficiency virus type 1 (HIV-1) vaccine immunogens that can elicit potent neutralizing antibodies. A prerequisite for comparing and optimizing these strategies is the ability to precisely measure neutralizing antibody responses. To this end, we sought to develop an assay that directly quantifies single-round HIV-1 infection of peripheral blood mononuclear cells (PBMC). Initial experiments demonstrated that essentially all productively infected PBMC could be identified by flow cytometric detection of intracellular p24 antigen (p24-Ag). After infection of PBMC with HIV-1, p24
+
lymphocytes could be distinguished beginning 1 day postinfection, and the majority of CD8
−
T cells were p24-Ag positive by 3 to 4 days postinfection. To directly quantify first-round infection, we included a protease inhibitor in PBMC cultures. The resulting 2-day assay was highly sensitive and specific for the detection of HIV-1-infected PBMC. Serial dilutions of virus stocks demonstrated that the number of target cells infected was directly related to the amount of infectious virus input into the assay. In neutralization assays, the flow cytometric enumeration of first-round infection of PBMC provided quantitative data on the number of target cells infected and on the inactivation of infectious virus due to reaction with antibody. We also used this single-round assay to compare the percentage of cells expressing p24-Ag to the number of copies of HIV-1
gag
per 100 PBMC. The precision and reproducibility of this assay will facilitate the measurement of HIV-1 neutralization, particularly incrementally improved neutralizing antibody responses generated by new candidate vaccines.
Measles Virus Preferentially Transduces the Basolateral Surface of Well-Differentiated Human Airway Epithelia
Authors: Sinn Patrick L. , Williams Greg , Vongpunsawad Sompong , Cattaneo Roberto , McCray Paul B. 
Published: July 2002

ABSTRACTMeasles virus (MV) is typically spread by aerosol droplets and enters via the respiratory tract. The progression of MV infection has been widely studied; yet, the pathway for virus entry in polarized human airway epithelia has not been investigated. Herein we report the use of a replication-competent Edmonston vaccine strain of MV expressing enhanced green fluorescent protein (MV-eGFP) to infect primary cultures of well-differentiated human airway epithelia. Previous studies with polarized Caco-2 cells (intestine-derived human epithelia) and MDCK cells (kidney-derived canine epithelia) demonstrated that MV primarily infected and exited the apical surface. In striking contrast, our results indicate that MV preferentially transduces human airway cells from the basolateral surface; however, virus release remains in an apical direction. When MV-eGFP was applied apically or basolaterally to primary cultures of airway epithelia, discrete foci of eGFP expression appeared and grew; however, the cell layer integrity was maintained for the duration of the study (7 days). Interestingly, utilizing immunohistochemistry and confocal microscopy, we observed widespread expression of the receptor for the vaccine strain of MV (CD46) at greatest abundance on the apical surface of the differentiated human airway epithelia as well as in human tracheal tissue sections. These data suggest that the progression of MV infection through the respiratory epithelium may involve pathways other than direct binding and entry through the apical surface of airway epithelia.
NK T Cells Contribute to Expansion of CD8+T Cells and Amplification of Antiviral Immune Responses to Respiratory Syncytial Virus
Authors: Johnson Teresa R. , Hong Seokmann , Van Kaer Luc , Koezuka Yasuhiko , Graham Barney S. 
Published: July 2002

ABSTRACTCD1d-deficient mice have normal numbers of T lymphocytes and natural killer cells but lack Vα14+natural killer T cells. Respiratory syncytial virus (RSV) immunopathogenesis was evaluated in 129×C57BL/6, C57BL/6, and BALB/c CD1d−/−mice. CD8+T lymphocytes were reduced in CD1d−/−mice of all strains, as shown by cell surface staining and major histocompatibility complex class I tetramer analysis, and resulted in strain-specific alterations in illness, viral clearance, and gamma interferon (IFN-γ) production. Transient activation of NK T cells in CD1d+/+mice by α-GalCer resulted in reduced illness and delayed viral clearance. These data suggest that early IFN-γ production and efficient induction of CD8+-T-cell responses during primary RSV infection require CD1d-dependent events. We also tested the ability of α-GalCer as an adjuvant to modulate the type 2 immune responses induced by RSV glycoprotein G or formalin-inactivated RSV immunization. However, immunized CD1-deficient or α-GalCer-treated wild-type mice did not exhibit diminished disease following RSV challenge. Rather, some disease parameters, including cytokine production, eosinophilia, and viral clearance, were increased. These findings indicate that CD1d-dependent NK T cells play a role in expansion of CD8+T cells and amplification of antiviral responses to RSV.
Preparation of Intermediates for Fluorinated Lignans by Conjugated and Tandem Additions on 3-Fluorofuran-2(5H)-one
Authors: Kvíčala Jaroslav , Vlasáková Růžena , Plocar Jakub , Paleta Oldřich , Pelter Andrew 
Published: July 2002

Two syntheses of 3-fluorofuran-2(5H)-one (1) based on Wittig-Horner reaction of ethyl (diethoxyphosphoryl)fluoroacetate (15) with 2-oxoethyl acetate (16) or on transformation of D-erythronolactone (10) are given. 3-Fluorofuran-2(5H)-one (1) and ethyl 2-fluorobut- 2-enoate (2) undergo conjugate addition with soft nucleophiles based on arene- carboxaldehyde dithioacetals 7 to form 2-fluorolactones 3 and 2-fluoroalkanoates 4. Intermediate enolates can be trapped in the sense of tandem addition with arenecarboxaldehydes 8 or (arylmethyl)bromides 9 to form intermediates 5 and 6 for fluorolignans. Although the conjugate addition proceeds with low stereoselectivity yielding mixture of both diastereoisomers, the electrophile in tandem addition attacks the intermediary fluoroenolate exclusively anti to its bulky β-substituent in good accord with non-fluorinated furan- 2(5H)-ones.
A comparison of lactate concentration in plasma collected from the toe, ear, and fingertip after a simulated rowing exercise
Authors: Forsyth J J , Farrally M R 
Published: July 2002

Objective—To examine the validity of using blood taken from the toe for the assessment of plasma lactate concentration in rowers. To achieve this, values were compared with those taken from the fingertip and earlobe.Methods—Nine subjects exercised at two separate submaximum workloads on the Concept II rowing ergometer. The loads, each lasting four minutes, elicited mean (SD) heart rate responses of 160.1 (8.5) and 180.1 (5.7) beats/min, which corresponded to 76.4 (6.1)% and 91.9 (4.7)% of the estimated heart rate maximum of the subjects. Blood was simultaneously removed after the cessation of exercise by three experimenters and was analysed for plasma lactate concentration.Results—At 76.4% of estimated heart rate maximum, the mean (SD) plasma lactate concentrations sampled from the fingertip, toe, and earlobe were 6.36 (1.58), 5.81 (1.11), and 5.29 (1.24) mmol/l respectively. At 91.9% of estimated heart rate maximum, respective values were 8.81 (2.30), 8.53 (1.37), and 8.41 (2.35) mmol/l. No significant differences (p>0.05) were found between any of the sites at either work intensity.Conclusions—The toe may offer a practical alternative for assessing the concentration of lactate during rowing, having the advantage that repeated blood samples can be removed without interruption of the rowing action.
Isokinetic performance and shoulder mobility in elite volleyball athletes from the United Kingdom
Authors: Wang Hsing-Kuo , Macfarlane Alison , Cochrane Tom 
Published: July 2002

Objectives—To evaluate the differences in strength and mobility of shoulder rotator muscles in the dominant and non-dominant shoulders of elite volleyball players.Methods—Isokinetic muscle strength tests were performed at speeds of 60 and 120°/s, and shoulder mobility was examined in ten players from the England national men's volleyball squad. The subjects also completed a questionnaire that included a visual prompt and analogue pain scale.Results—The range of motion of internal rotation on the dominant side was less than that on the non-dominant side (p<0.01). The average peak strength at 60°/s external eccentric contraction was lower than that of internal concentric contraction in the dominant arm, but was higher in the non-dominant arm. Six of the ten subjects reported a shoulder problem, described as a diffuse pain located laterally on the dominant shoulder.Conclusions—These elite volleyball players had a lower range of motion (internal rotation) and relative muscle imbalance in the dominant compared with the non-dominant shoulder.
The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinopathy
Authors: Robinson J M , Cook J L , Purdam C , Visentini P J , Ross J , Maffulli N , Taunton J E , Khan K M 
Published: July 2002

Background—There is no disease specific, reliable, and valid clinical measure of Achilles tendinopathy.Objective—To develop and test a questionnaire based instrument that would serve as an index of severity of Achilles tendinopathy.Methods—Item generation, item reduction, item scaling, and pretesting were used to develop a questionnaire to assess the severity of Achilles tendinopathy. The final version consisted of eight questions that measured the domains of pain, function in daily living, and sporting activity. Results range from 0 to 100, where 100 represents the perfect score. Its validity and reliability were then tested in a population of non-surgical patients with Achilles tendinopathy (n = 45), presurgical patients with Achilles tendinopathy (n = 14), and two normal control populations (total n = 87).Results—The VISA-A questionnaire had good test-retest (r= 0.93), intrarater (three tests,r= 0.90), and interrater (r= 0.90) reliability as well as good stability when compared one week apart (r= 0.81). The mean (95% confidence interval) VISA-A score in the non-surgical patients was 64 (59–69), in presurgical patients 44 (28–60), and in control subjects it exceeded 96 (94–99). Thus the VISA-A score was higher in non-surgical than presurgical patients (p = 0.02) and higher in control subjects than in both patient populations (p<0.001).Conclusions—The VISA-A questionnaire is reliable and displayed construct validity when means were compared in patients with a range of severity of Achilles tendinopathy and control subjects. The continuous numerical result of the VISA-A questionnaire has the potential to provide utility in both the clinical setting and research. The test is not designed to be diagnostic. Further studies are needed to determine whether the VISA-A score predicts prognosis.