bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epstein-Barr Virus Nuclear Antigen 3C Putative Repression Domain Mediates Coactivation of the LMP1 Promoter with EBNA-2
Authors: Lin Jeffrey , Johannsen Eric , Robertson Erle , Kieff Elliott 
Published: July 2002

ABSTRACT
The Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA-3C) regulates virus and cell genes and is essential for EBV-mediated transformation of primary B lymphocytes. EBNA-3C associates with the cellular DNA sequence-specific transcription factors RBP-Jκ and PU.1 and coactivates the EBV LMP1 promoter with EBNA-2 in BL2 and Raji cells under conditions of restrictive growth. We now find that EBNA-3C is similar to EBNA-LP in coactivating the LMP1 promoter with EBNA-2 in non-EBV-infected Burkitt lymphoma cells under conditions of maximal cell growth, whereas the EBV Cp promoter is repressed under the same conditions. EBNA-3A and EBNA-3B coactivation are at most 40% that of EBNA-3C. The RBP-Jκ binding sites of EBNA-2 and the LMP1 promoter are not required for EBNA-3C coactivation, whereas the PU.1 site in the LMP1 promoter is required for EBNA-2-mediated activation and EBNA-3C coactivation. EBNA-3C amino acids (aa) 365 to 545, including most of the previously identified repression domain (M. Bain, R. J. Watson, P. J. Farrell, and M. J. Allday, J. Virol. 70:2481–2489, 1996), are necessary and sufficient for coactivation with wild-type EBNA-2. EBNA-3C can also coactivate with the EBNA-2 acidic activating domain; this activation does not require aa 343 to 545. These data indicate that there are at least two mechanisms by which EBNA-3C coactivates the LMP1 promoter with EBNA-2. Of the proteins that interact with EBNA-3C in a yeast two-hybrid screen, only the ubiquitin-like proteins SUMO-1 and SUMO-3/hSMT3B map to aa 365 to 545, implicating these molecules in EBNA-3C coactivation. In addition, SUMO-1 associates at a high level with EBNA-3C in lymphoblasts. Promoter coactivation by EBNA-3C is likely to be important in ensuring adequate levels of LMP1, while inhibition of the EBNA-Cp promoter under the same conditions prevents uncontrolled up-regulation of EBNA expression from a positive-feedback loop.
The Central Conserved Cystine Noose of the Attachment G Protein of Human Respiratory Syncytial Virus Is Not Required for Efficient Viral Infection In Vitro or In Vivo
Authors: Teng Michael N. , Collins Peter L. 
Published: July 2002

ABSTRACT
The G glycoprotein of human respiratory syncytial virus (RSV) was identified previously as the viral attachment protein. Although we and others recently showed that G is not essential for replication in vitro, it does affect the efficiency of replication in a cell type-dependent fashion and is required for efficient replication in vivo. The ectodomain of G is composed of two heavily glycosylated domains with mucin-like characteristics that are separated by a short central region that is relatively devoid of glycosylation sites. This central region contains a 13-amino acid segment that is conserved in the same form among RSV isolates and is overlapped by a second segment containing four cysteine residues whose spacings are conserved in the same form and which create a cystine noose. The conserved nature of the cystine noose and flanking 13-amino acid segment suggested that this region likely was important for attachment activity. To test this hypothesis, we constructed recombinant RSVs from which the region containing the cysteine residues was deleted together with part or all of the conserved 13-amino acid segment. Surprisingly, each deletion had little or no effect on the intracellular synthesis and processing of the G protein, the kinetics or efficiency of virus replication in vitro, or sensitivity to neutralization by soluble heparin in vitro. In addition, neither deletion had any discernible effect on the ability of RSV to infect the upper respiratory tract of mice and both resulted in a 3- to 10-fold reduction in the lower respiratory tract. Thus, although the G protein is necessary for efficient virus replication in vivo, this activity does not require the central conserved cystine noose region.
Bipartite Signal for Genomic RNA Dimerization in Moloney Murine Leukemia Virus
Authors: Ly Hinh , Parslow Tristram G. 
Published: July 2002

ABSTRACT
Retroviral virions each contain two identical genomic RNA strands that are stably but noncovalently joined in parallel near their 5′ ends. For certain viruses, this dimerization has been shown to depend on a unique RNA stem-loop locus, called the dimer initiation site (DIS), that efficiently homodimerizes through a palindromic base sequence in its loop. Previous studies with Moloney murine leukemia virus (Mo-MuLV) identified two alternative DIS loci that can each independently support RNA dimerization in vitro but whose relative contributions are unknown. We now report that both of these loci contribute to the assembly of the Mo-MuLV dimer. Using targeted deletions, point mutagenesis, and antisense oligonucleotides, we found that each of the two stem-loops forms as predicted and contributes independently to dimerization in vitro through a mechanism involving autocomplementary interactions of its loop. Disruption of either DIS locus individually reduced both the yield and the thermal stability of the in vitro dimers, whereas disruption of both eliminated dimerization altogether. Similarly, the thermal stability of virion-derived dimers was impaired by deletion of both DIS elements, and point mutations in either element produced defects in viral replication that correlated with their effects on in vitro RNA dimerization. These findings support the view that in some retroviruses, dimer initiation and stability involve two or more closely linked DIS loci which together align the nascent dimer strands in parallel and in register.
Subcellular Localization and Topology of the p7 Polypeptide of Hepatitis C Virus
Authors: Carrère-Kremer Séverine , Montpellier-Pala Claire , Cocquerel Laurence , Wychowski Czeslaw , Penin François , Dubuisson Jean 
Published: July 2002

ABSTRACT
Although biological and biochemical data have been accumulated on most hepatitis C virus proteins, the structure and function of the 63-amino-acid p7 polypeptide of this virus have never been investigated. In this work, sequence analyses predicted that p7 contains two transmembrane passages connected by a short hydrophilic segment. The C-terminal transmembrane domain of p7 was predicted to function as a signal sequence, which was confirmed experimentally by analyzing the translocation of a reporter glycoprotein fused at its C terminus. The p7 polypeptide was tagged either with the ectodomain of CD4 or with a Myc epitope to study its membrane integration, its subcellular localization, and its topology. Alkaline extraction studies confirmed that p7 is an integral membrane polypeptide. The CD4-p7 chimera was detected by immunofluorescence on the surface of nonpermeabilized cells, indicating that it is exported to the plasma membrane. However, pulse-chase analyses showed that only approximately 20% of endoglycosidase H-resistant CD4-p7 was detected after long chase times, suggesting that a large proportion of p7 stays in an early compartment of the secretory pathway. Finally, by inserting a Myc epitope in several positions of p7 and analyzing the accessibility of this epitope on the plasma membrane of HepG2 cells, we showed that p7 has a double membrane-spanning topology, with both its N and C termini oriented toward the extracellular environment. Altogether, these data indicate that p7 is a polytopic membrane protein that could have a functional role in several compartments of the secretory pathway.
Human Herpesvirus 8 Glycoprotein B (gB), gH, and gL Can Mediate Cell Fusion
Authors: Pertel Peter E. 
Published: July 2002

ABSTRACTHerpesvirus entry into cells and herpesvirus-induced cell fusion are related processes in that virus penetration proceeds by fusion of the viral envelope and cell membrane. To characterize the human herpesvirus 8 (HHV-8) glycoproteins that can mediate cell fusion, a luciferase reporter gene activation assay was used. Chinese hamster ovary (CHO) cells expressing the HHV-8 glycoproteins of interest along with a luciferase reporter gene under the control of the T7 promoter were cocultivated with human cells transfected with T7 RNA polymerase. Because HHV-8 glycoprotein B (gB) expressed in CHO cells localizes to the perinuclear region, a truncated form of gB (designated gBMUT) that lacks putative endocytosis signals was constructed by deletion of the distal 58 amino acids of the cytoplasmic tail. HHV-8 gBMUTwas expressed efficiently on the surface of CHO cells. HHV-8 gB, gH, and gL could mediate the fusion of CHO cells with two different human cell types, embryonic kidney cells and B lymphocytes. Substituting gBMUTfor gB significantly enhanced the fusion of CHO cells with human embryonic kidney cells but not B lymphocytes. Thus, two human cell types known to be susceptible to HHV-8 entry were also suitable targets for cell fusion induced by HHV-8 gB, gH, and gL. For human embryonic kidney cells and B cells at least, optimal fusion was noted with the expression of all three HHV-8 glycoproteins.
Effect of Temperature on the Solubility Diagrams of Ammonium Bromcarnallite
Authors: Christov Christomir , Balarew Christo 
Published: July 2002

The solubility isotherms of the systems NH4Br - MgBr2 - H2O and NH4Br . MgBr2 . 6 H2O - MgBr2 - H2O have been investigated by the physicochemical analysis method at 75 °C and formation of carnallite type double salt is established. The effect of temperature on the crystallization conditions is discussed.
Transient forces generated by projectiles on variable quality mouthguards monitored by instrumented impact testing
Authors: Warnet L , Greasley A 
Published: July 2002

Objectives—(a) To determine the force-time trace that occurs when a spring mounted simulated upper jaw is impacted; (b) to examine if mouthguards of variable quality have significant influence on such force-time traces; (c) to attempt to relate physical events to the profile of the force-time traces recorded.Methods—A simulated jaw, consisting of ceramic teeth inserted into a hard rubber arch reinforced with a composite jawbone, was fitted with various mouthguards as part of a previous round robin study. A clinical assessment distinguished good, bad, and poor mouthguards, and these were each fitted to the jaw, which was then submitted to instrumental impact tests under conditions expected to produce tooth fractures. The force-time trace was recorded for such impact events.Results—The spring mounting method caused two distinct peaks in the force-time trace. The initial one was related to inertia effects and showed an increase in magnitude with impactor velocity as expected. The second peak showed features that were related to the differences in the mouthguards selected.Conclusions—The use of a force washer within a conical ended impactor enabled force-time traces to be recorded during the impact of a spring mounted simulated jaw fitted with mouthguards of variable quality. The spring mounting system causes an initial inertial peak followed by a second peak once the spring mount has fully compressed. Good fitting guards, which keep most teeth intact, result in high stiffness targets that in turn generate high reaction forces in the impactor. If the spring mounting is omitted, the two peaks are combined to give even higher reaction forces. The force-time trace offers some potential for assessing both overall mouthguard performance and individual events during the impact sequence. Mouthguards with good retention to the jaw remained attached during the impact event and helped to preserve the structural integrity of the target. This in turn developed high forces in the second part of the force-time trace. Guards that detached during impact and allowed tooth fractures showed lower forces in the second part of the test. The force profile measured offered some quantitative support to, and agreement with, the observed clinical quality of the mouthguards.
Computerised cognitive assessment of concussed Australian Rules footballers
Authors: Makdissi M , Collie A , Maruff P , Darby D G , Bush A , McCrory P , Bennell K 
Published: July 2002

Background—“Paper and pencil” neuropsychological tests play an important role in the management of sports related concussions. They provide objective information on the athlete's cognitive function and thus facilitate decisions on safe return to sport. It has been proposed that computerised cognitive tests have many advantages over such conventional tests, but their role in this domain is yet to be established.Objectives—To measure cognitive impairment after concussion in a case series of concussed Australian Rules footballers, using both computerised and paper and pencil neuropsychological tests. To investigate the role of computerised cognitive tests in the assessment and follow up of sports related concussions.Methods—Baseline measures on the Digit Symbol Substitution Test (DSST), Trail Making Test-Part B (TMT), and a simple reaction time (SRT) test from a computerised cognitive test battery (CogState) were obtained in 240 players. Tests were repeated in players who had sustained a concussive injury. A group of non-injured players were used as matched controls.Results—Six concussions were observed over a period of nine weeks. At the follow up, DSST and TMT scores did not significantly differ from baseline scores in both control and concussed groups. However, analysis of the SRT data showed an increase in response variability and latency after concussion in the injured athletes. This was in contrast with a decrease in response variability and no change in latency on follow up of the control players (p<0.02).Conclusion—Increased variability in response time may be an important cognitive deficit after concussion. This has implications for consistency of an athlete's performance after injury, as well as for tests used in clinical assessment and follow up of head injuries.
Effects of rapid weight loss on mood and performance among amateur boxers
Authors: Hall C J , Lane A M 
Published: July 2002

Aims—To examine the effects of rapid weight loss on mood and performance among amateur boxers.Methods—Participants were 16 experienced amateur boxers. In stage 1, structured interviews were used to assess the type of strategies that boxers used to reduce weight and the value of performing at their desired weight in terms of performance. In stage 2, boxers completed a 4 × 2 minute (1 minute recovery) circuit training session. Boxers completed the circuit training session on three different occasions with a week between each. The first test was used to familiarise the boxers with the circuit training task; the second and third tasks were at their training weight and championship weight, respectively. Participants were given one week to reduce their body weight to their championship weight using their preferred weight making strategies; boxers reduced their body weight by an average of 5.16% of body weight.Results—Boxers typically lost weight by restricting fluid and food intake in the week leading to competition. Repeated measures multivariate analysis of variance results indicated that rapid weight loss among boxers was associated with poor performance, increased anger, fatigue, and tension, and reduced vigour.Conclusions—Strategies used to make weight by boxers are associated with poor performance and a negative mood profile.
Validation of Ottawa ankle rules protocol in Greek athletes: study in the emergency departments of a district general hospital and a sports injuries clinic
Authors: Papacostas E , Malliaropoulos N , Papadopoulos A , Liouliakis C 
Published: July 2002

Objective—To validate the Ottawa ankle rules protocol for predicting ankle and midfoot fractures in Greek athletes.Method—A prospective survey in the emergency departments of a district general hospital and a sports injury clinic in Greece over nine months. A clinical evaluation was made of 122 patients with acute ankle and/or midfoot injury, and then radiographs were taken.Results—Nine ankle and eight midfoot fractures were detected. The sensitivity of the Ottawa ankle rules protocol in predicting fractures in both the malleolar and midfoot zones was 100%. The negative predictive value for each of these areas was also 1.0. Specificity was estimated to be 0.3 for ankle fractures and 0.4 for midfoot fractures. Positive predictive values were 0.16 and 0.28 respectively. A possible reduction of up to 28.7% was found in the need for radiography.Conclusions—Use of the Ottawa ankle rules protocol in evaluating injured Greek athletes resulted in 100% sensitivity when performed by orthopaedic residents or sports medicine doctors, and had the potential to reduce the use of radiography.
Soluble E-cadherin is a valid prognostic marker in gastric carcinoma
Authors: Chan A O O , Lam S K , Chu K M , Lam C M , Kwok E , Leung S Y , Yuen S T , Law S Y K , Hui W M , Lai K C , Wong C Y , Hu H C , Lai C L , Wong J 
Published: July 2002

BACKGROUNDGastric cancer remains a major cause of cancer mortality globally but no good prognostic tumour marker is available. Soluble fragment of E-cadherin protein has been reported to increase in the sera of patients with cancer and recently was found to be elevated in 67% of patients with gastric cancer.AIMSTo investigate if serum soluble E-cadherin is a valid prognostic marker in gastric cancer.METHODSConcentrations of soluble E-cadherin from 116 patients with histologically confirmed gastric adenocarinoma and 40 healthy subjects were measured using an immunoenzymometric method with a commercially available sandwich ELISA kit based on monoclonal antibodies.RESULTSThe logarithm of the means of soluble E-cadherin concentration was significantly higher in patients with gastric cancers (mean 3.85 (SD 0.28)) than in healthy subjects (3.71 (0.18)) (p=0.001), and in palliative/conservatively treated cancers (3.91 (0.35)) than in operable cancers (3.78 (0.19)) (p=0.015). The logarithm of the concentrations correlated with tumour size (p=0.032) and carcinoembryonic antigen concentrations (p=0.001). The cut off value calculated from discriminant analysis on operability and inoperability/palliative treatment was 7025 ng/ml. Soluble E-cadherin concentrations higher than this cut off value predicted tumour (T4) depth invasion (p=0.020, confidence interval (CI) 1.008–1.668) and palliative/conservative treatment (p=0.023, CI 1.038–2.514). In contrast, the relative risks for lymph node (N2) metastasis, distant metastasis, and stage III/IV disease were 1.41, 1.33, and 1.55 respectively, despite not reaching statistical significance.CONCLUSIONSerum soluble E-cadherin is a potential valid prognostic marker for gastric cancer. A high concentration predicts palliative/conservative treatment and T4 invasion.
‘End-of-life’ decision making within intensive care - objective, consistent, defensible?
Authors: Ravenscroft Andrew J , Bell M D Dominic 
Published: July 2002

Objective—To determine the objectivity, consistency and professional unanimity in the initiation, continuation and withdrawal of life-prolonging procedures in intensive care–to determine methods, time-scale for withdrawal and communication with both staff and relatives–to explore any professional unease about legality, morality or professional defensibility.Design—A structured questionnaire directed at clinical nurse managers for intensive care.Setting—All intensive care units in the Yorkshire region.Results—The survey reported a lack of consistency and objectivity in decision making in this area, with accompanying unease amongst staff.Conclusions—There is a need to work towards more consistent care, both before and during admission, for the protection of the individual patient and to allow rational assessment of intensive care need. Comprehensive audit should lead to objective defensible decisions and facilitate informed choice. More open debate and better communication should minimise this issue as a source of stress amongst staff in intensive care.
Don't cry for us Argentinians: two decades of teaching medical humanities
Authors: Acuña Leopoldo E 
Published: July 2002

Medical humanities—history, literature, anthropology, ethics and fine arts applied to medicine—play an important role in medical education. For more than 20 years an effort has been made to obtain an academic identity for such a multidisciplinary approach. A distinction between humanitarianism and humanism is attempted here, the former being associated with medical care and the latter with medical education. In order more precisely to define the relationship between the arts and medicine, an alternative term “medical kalology”, as-yet-unsanctioned, coined after the rules of medical terminology, is proposed.The Department of Medical Humanities in the School of Medicine, National University of La Plata, submits the following apologia: Don't cry for us Argentinians, since the teaching of medical humanities has helped our doctors to function more truly humanistically during the past two decades, and we intend to continue with this calling in the future.
Workplace exposures and oesophageal cancer
Authors: Parent Marie-Élise , Siemiatycki Jack , Fritschi Lin 
Published: July 2002

OBJECTIVESTo describe the relation between oesophageal cancer and many occupational circumstances with data from a population based case-control study.METHODSCases were 99 histologically confirmed incident cases of cancer of the oesophagus, 63 of which were squamous cell carcinomas. Various control groups were available; for the present analysis a group was used that comprised 533 population controls and 533 patients with other types of cancer. Detailed job histories were elicited from all subjects and were translated by a team of chemists and hygienists for evidence of exposure to 294 occupational agents. Based on preliminary results and a review of literature, a set of 35 occupational agents and 19 occupations and industry titles were selected for this analysis. Logistic regression analyses were adjusted for age, birthplace, education, respondent (self or proxy), smoking, alcohol, and β-carotene intake.RESULTSSulphuric acid and carbon black showed the strongest evidence of an association with oesophageal cancer, particularly squamous cell carcinoma. Other substances showed excess risks, but the evidence was more equivocal—namely chrysotile asbestos, alumina, mineral spirits, toluene, synthetic adhesives, other paints and varnishes, iron compounds, and mild steel dust. There was considerable overlap in occupational exposure patterns and results for some of these substances may be mutually confounded. None of the occupations or industry titles showed a clear excess risk; the strongest hints were for warehouse workers, food services workers, and workers from the miscellaneous food industry.CONCLUSIONSThe data provide some support for an association between oesophageal cancer and a handful of occupational exposures, particularly sulphuric acid and carbon black. Many of the associations found have never been examined before and warrant further investigation.