bluuebunny/crossref_metadata_2025_split huggingface dataset:
Overlapping Motifs (PTAP and PPEY) within the Ebola Virus VP40 Protein Function Independently as Late Budding Domains: Involvement of Host Proteins TSG101 and VPS-4
Authors: Licata Jillian M. , Simpson-Holley Martha , Wright Nathan T. , Han Ziying , Paragas Jason , Harty Ronald N. 
Published: January 2003

ABSTRACT
The VP40 protein of Ebola virus can bud from mammalian cells in the form of lipid-bound, virus-like particles (VLPs), and late budding domains (L-domains) are conserved motifs (PTAP, PPxY, or YxxL; where “x” is any amino acid) that facilitate the budding of VP40-containing VLPs. VP40 is unique in that potential overlapping L-domains with the sequences PTAP and PPEY are present at amino acids 7 to 13 of VP40 (PTAPPEY). L-domains are thought to function by interacting with specific cellular proteins, such as the ubiquitin ligase Nedd4, and a component of the vacuolar protein sorting (vps) pathway, tsg101. Mutational analysis of the PTAPPEY sequence of VP40 was performed to understand further the contribution of each individual motif in promoting VP40 budding. In addition, the contribution of tsg101 and a second member of the vps pathway, vps4, in facilitating budding was addressed. Our results indicate that (i) both the PTAP and PPEY motifs contribute to efficient budding of VP40-containing VLPs; (ii) PTAP and PPEY can function as L-domains when separated and moved from the N terminus (amino acid position 7) to the C terminus (amino acid position 316) of full-length VP40; (iii) A VP40-PTAP/tsg101 interaction recruits tsg101 into budding VLPs; (iv) a VP40-PTAP/tsg101 interaction recruits VP40 into lipid raft microdomains; and (v) a dominant-negative mutant of vps4 (E228Q), but not wild-type vps4, significantly inhibited the budding of Ebola virus (Zaire). These results provide important insights into the complex interplay between viral and host proteins during the late stages of Ebola virus budding.
Binding of the Hepatitis C Virus E2 Glycoprotein to CD81 Is Strain Specific and Is Modulated by a Complex Interplay between Hypervariable Regions 1 and 2
Authors: Roccasecca RosaMaria , Ansuini Helenia , Vitelli Alessandra , Meola Annalisa , Scarselli Elisa , Acali Stefano , Pezzanera Monica , Ercole Bruno Bruni , McKeating Jane , Yagnik Asutosh , Lahm Armin , Tramontano Anna , Cortese Riccardo , Nicosia Alfredo 
Published: January 2003

ABSTRACT
The envelope glycoprotein E2 of hepatitis C virus (HCV) is the target of neutralizing antibodies and is presently being evaluated as an HCV vaccine candidate. HCV binds to human cells through the interaction of E2 with the tetraspanin CD81, a putative viral receptor component. We have analyzed four different E2 proteins from 1a and 1b viral isolates for their ability to bind to recombinant CD81 in vitro and to the native receptor displayed on the surface of Molt-4 cells. A substantial difference in binding efficiency between these E2 variants was observed, with proteins derived from 1b subtypes showing significantly lower binding than the 1a protein. To elucidate the mechanism of E2-CD81 interaction and to identify critical regions responsible for the different binding efficiencies of the E2 variants, several mutants were generated in E2 protein regions predicted by computer modeling to be exposed on the protein surface. Functional analysis of these E2 derivatives revealed that at least two distinct domains are responsible for interaction with CD81. A first segment centered around amino acid residues 613 to 618 is essential for recognition, while a second element including the two hypervariable regions (HVRs) modulates E2 receptor binding. Binding inhibition experiments with anti-HVR monoclonal antibodies confirmed this mapping and supported the hypothesis that a complex interplay between the two HVRs of E2 is responsible for modulating receptor binding, possibly through intramolecular interactions. Finally, E2 proteins from different isolates displayed a profile of binding to human hepatic cells different from that observed on Molt-4 cells or isolated recombinant CD81, indicating that additional factors are involved in viral recognition by target liver cells.
Impact of Highly Active Antiretroviral Therapy and Immunologic Status on Hepatitis C Virus Quasispecies Diversity in Human Immunodeficiency Virus/Hepatitis C Virus-Coinfected Patients
Authors: Babik Jennifer M. , Holodniy Mark 
Published: January 2003

ABSTRACT

This study analyzes the effect of highly active antiretroviral therapy (HAART), and thus immunologic status, on hepatitis C virus (HCV) load and quasispecies diversity in patients coinfected with the human immunodeficiency virus (HIV) and HCV. Three cohorts of coinfected patients were analyzed retrospectively over a period of 7 to 10 months: group A was antiretroviral drug naïve at baseline and then on HAART for the remainder of the study, group B did not receive antiretroviral therapy at any point, and group C was on HAART for the entire study. HCV quasispecies diversity was analyzed by sequencing hypervariable region 1. In a longitudinal analysis, there was no significant change from baseline in any immunologic, virologic, or quasispecies parameter in any of the three groups. However, in comparison to groups A and B, group C had significantly higher CD4
+
- and CD8
+
-cell counts, a trend toward a higher HCV load, and significantly increased number of HCV clones, entropy, genetic distance, and ratio of nonsynonymous substitutions per nonsynonymous site to synonymous substitutions per synonymous site (

K
a

/

K
s

). In addition, CD4
+
-cell count was positively correlated with HCV load, genetic distance, and

K
a

. Interestingly, patients infected with HCV genotype 2 or 3 had a significantly higher CD4
+
-cell count, HCV load, genetic distance, and

K
a

/

K
s

than those infected with genotype 1. These results suggest that there is no immediate effect of HAART on HCV but that, with prolonged HAART, immune restoration results in an increase in HCV load and quasispecies diversity.
Importance of Basic Residues in Binding of Rous Sarcoma Virus Nucleocapsid to the RNA Packaging Signal
Authors: Lee Eun-gyung , Alidina Annie , May Cynthia , Linial Maxine L. 
Published: January 2003

ABSTRACT

In the context of the Rous sarcoma virus Gag polyprotein, only the nucleocapsid (NC) domain is required to mediate the specificity of genomic RNA packaging. We have previously showed that the
Saccharomyces cerevisiae
three-hybrid system provides a rapid genetic assay to analyze the RNA and protein components of the avian retroviral RNA-Gag interactions necessary for specific encapsidation. In this study, using both site-directed mutagenesis and in vivo random screening in the yeast three-hybrid binding assay, we have examined the amino acids in NC required for genomic RNA binding. We found that we could delete either of the two Cys-His boxes without greatly abrogating either RNA binding or packaging, although the two Cys-His boxes are likely to be required for efficient viral assembly and release. In contrast, substitutions for the Zn-coordinating residues within the boxes did prevent RNA binding, suggesting changes in the overall conformation of the protein. In the basic region between the two Cys-His boxes, three positively charged residues, as well as basic residues flanking the two boxes, were necessary for both binding and packaging. Our results suggest that the stretches of positively charged residues within NC that need to be in a proper conformation appear to be responsible for selective recognition and binding to the packaging signal (Ψ)-containing RNAs.
Exonic Splicing Enhancer-Dependent Selection of the Bovine Papillomavirus Type 1 Nucleotide 3225 3′ Splice Site Can Be Rescued in a Cell Lacking Splicing Factor ASF/SF2 through Activation of the Phosphatidylinositol 3-Kinase/Akt Pathway
Authors: Liu Xuefeng , Mayeda Akila , Tao Mingfang , Zheng Zhi-Ming 
Published: January 2003

ABSTRACTBovine papillomavirus type 1 (BPV-1) late pre-mRNAs are spliced in keratinocytes in a differentiation-specific manner: the late leader 5′ splice site alternatively splices to a proximal 3′ splice site (at nucleotide 3225) to express L2 or to a distal 3′ splice site (at nucleotide 3605) to express L1. Two exonic splicing enhancers, each containing two ASF/SF2 (alternative splicing factor/splicing factor 2) binding sites, are located between the two 3′ splice sites and have been identified as regulating alternative 3′ splice site usage. The present report demonstrates for the first time that ASF/SF2 is required under physiological conditions for the expression of BPV-1 late RNAs and for selection of the proximal 3′ splice site for BPV-1 RNA splicing in DT40-ASF cells, a genetically engineered chicken B-cell line that expresses only human ASF/SF2 controlled by a tetracycline-repressible promoter. Depletion of ASF/SF2 from the cells by tetracycline greatly decreased viral RNA expression and RNA splicing at the proximal 3′ splice site while increasing use of the distal 3′ splice site in the remaining viral RNAs. Activation of cells lacking ASF/SF2 through anti-immunoglobulin M-B-cell receptor cross-linking rescued viral RNA expression and splicing at the proximal 3′ splice site and enhanced Akt phosphorylation and expression of the phosphorylated serine/arginine-rich (SR) proteins SRp30s (especially SC35) and SRp40. Treatment with wortmannin, a specific phosphatidylinositol 3-kinase/Akt kinase inhibitor, completely blocked the activation-induced activities. ASF/SF2 thus plays an important role in viral RNA expression and splicing at the proximal 3′ splice site, but activation-rescued viral RNA expression and splicing in ASF/SF2-depleted cells is mediated through the phosphatidylinositol 3-kinase/Akt pathway and is associated with the enhanced expression of other SR proteins.
Determinant for Endoplasmic Reticulum Retention in the Luminal Domain of the Human Cytomegalovirus US3 Glycoprotein
Authors: Lee Sungwook , Park Boyoun , Ahn Kwangseog 
Published: January 2003

ABSTRACT

US3 of human cytomegalovirus is an endoplasmic reticulum resident transmembrane glycoprotein that binds to major histocompatibility complex class I molecules and prevents their departure. The endoplasmic reticulum retention signal of the US3 protein is contained in the luminal domain of the protein. To define the endoplasmic reticulum retention sequence in more detail, we have generated a series of deletion and point mutants of the US3 protein. By analyzing the rate of intracellular transport and immunolocalization of the mutants, we have identified Ser
58
, Glu
63
, and Lys
64
as crucial for retention, suggesting that the retention signal of the US3 protein has a complex spatial arrangement and does not comprise a contiguous sequence of amino acids. We also show that a modified US3 protein with a mutation in any of these amino acids maintains its ability to bind class I molecules; however, such mutated proteins are no longer retained in the endoplasmic reticulum and are not able to block the cell surface expression of class I molecules. These findings indicate that the properties that allow the US3 glycoprotein to be localized in the endoplasmic reticulum and bind major histocompatibility complex class I molecules are located in different parts of the molecule and that the ability of US3 to block antigen presentation is due solely to its ability to retain class I molecules in the endoplasmic reticulum.
Noninvasive Detection of New Simian Immunodeficiency Virus Lineages in Captive Sooty Mangabeys: Ability To Amplify Virion RNA from Fecal Samples Correlates with Viral Load in Plasma
Authors: Ling Binhua , Santiago Mario L. , Meleth Sreelatha , Gormus Bobby , McClure Harold M. , Apetrei Cristian , Hahn Beatrice H. , Marx Preston A. 
Published: January 2003

ABSTRACTThe sooty mangabey (SM) (Cercocebus atys) is the natural host of a simian immunodeficiency virus, termed SIVsm, which gave rise to human immunodeficiency virus type 2. Data on the geographic distribution, prevalence, and genetic diversity of SIVsm in the wild remains limited. To address this issue, noninvasive strategies based on screening SM fecal and urine specimens for SIVsm-specific antibodies and virion RNA (vRNA) were developed, and the results were correlated with viral loads in plasma. Twenty-three SIVsm-infected and 27 uninfected SMs were evaluated. Time-matched urine, fecal and plasma samples were collected over a 2-month period from 16 captive naturally infected SMs. The remaining 7 infected and 27 uninfected SMs were sampled once. Each specimen was subjected to enhanced chemiluminescence-Western blot analysis and nested reverse transcriptase (RT) PCR. The results showed that urine was highly sensitive (96%) and specific (100%) for detection of SIVsm antibodies, while fecal detection was much less sensitive (16%). Conversely, vRNA detection was more sensitive in feces (50%) than in urine (2%) samples. Fecal-vRNA detection correlated with viral loads in plasma (P< 0.002). SMs with detectable fecal vRNA had a mean viral load in plasma of 458,006 copies/ml, while those with undetectable fecal vRNA had a mean viral load in plasma of 29,428 copies/ml. Moreover, for every log increase in the viral load in plasma, the odds of detecting virus in fecal samples increased 87-fold. Genetic diversity of SIVsm in the SM colony was characterized by sequencing partialgag(846 bp) andgp43(439 bp) fragments. Surprisingly, four new SIVsm lineages were identified, two of which were initially detected by fecal RT-PCR. This study documents the suitability of noninvasive methods for the detection and molecular characterization of new SIV variants. These assays will be useful for studying the phylogeny and epidemiology of SIVsm infections in the wild, and they hold promise as tools for investigating natural SIV infections in endangered nonhuman primates.
The Foot-and-Mouth Disease Virus
cis
-Acting Replication Element (
cre
) Can Be Complemented in
trans
within Infected Cells
Authors: Tiley Laurence , King Andrew M. Q. , Belsham Graham J. 
Published: January 2003

ABSTRACT

A temperature-sensitive (
ts
) mutation was identified within the 5′-untranslated region of foot-and-mouth disease virus (FMDV) RNA. The mutation destabilizes a stem-loop structure recently identified as a
cis
-acting replication element (
cre
). Genetic analyses indicated that the
ts
defect in virus replication could be complemented. Thus, the FMDV
cre
can function in
trans
. It is suggested that the
cre
be renamed a 3B-uridylylation site (
bus
).
Genetics and Pathophysiology of Human Obesity
Authors: Cummings David E. , Schwartz Michael W. 
Published: January 2003

Obesity has become a leading public health concern. Over 1 billion people are now overweight or obese, and the prevalence of these conditions is rising rapidly. Remarkable new insights into the mechanisms that control body weight are providing an increasingly detailed framework for a better understanding of obesity pathogenesis. Key peripheral signals, such as leptin, insulin, and ghrelin, have been linked to hypothalamic neuropeptide systems, and the anatomic and functional networks that integrate these systems have begun to be elucidated. This article highlights some of these recent findings and their implications for the future of obesity treatment. “Banish plump Jack, and banish all the world.” William Shakespeare, King Henry IV Part 1
Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury
Authors: Bouhemad Bélaid , Richecoeur Jack , Lu Qin , Malbouisson Luiz M , Cluzel Philippe , Rouby Jean-Jacques ,   and the CT Scan Study Group ARDS
Published: January 2003

Abstract
Background
Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury.

Method
A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.

Results
Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml.

Conclusion
Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.
Esophageal capnometry during hemorrhagic shock and after resuscitation in rats
Authors: Totapally Balagangadhar R , Fakioglu Harun , Torbati Dan , Wolfsdorf Jack 
Published: January 2003

Abstract
Background
Splanchnic perfusion following hypovolemic shock is an important marker of adequate resuscitation. We tested whether the gap between esophageal partial carbon dioxide tension (PeCO2) and arterial partial carbon dioxide tension (PaCO2) is increased during graded hemorrhagic hypotension and reversed after blood reinfusion, using a fiberoptic carbon dioxide sensor.

Materials and method
Ten Sprague–Dawley rats were anesthetized, tracheotomized, and cannulated in one femoral artery and vein. A calibrated fiberoptic PCO2 probe was inserted into the distal third of the esophagus for determination of luminal PeCO2 during maintained anesthesia (pentobarbital 15 mg/kg per hour), normothermia (38 ± 0.5°C), and fluid balance (saline 5 ml/kg per hour). Three out of 10 rats were used to determine the limits of hemodynamic stability during gradual hemorrhage. Seven of the 10 rats were then subjected to mild and severe hemorrhage (15 and 20–25 ml/kg, respectively). Thirty minutes after severe hemorrhage, these rats were resuscitated by reinfusion of the shed blood. Arterial gas exchange, hemodynamic variables, and PeCO2 were recorded at each steady-state level of hemorrhage (at 30 and 60 min) and after resuscitation.

Results
The PeCO2–PaCO2 gap was significantly increased after mild and severe hemorrhage and returned to baseline (prehemorrhagic) values following blood reinfusion. Base deficit increased significantly following severe hemorrhage and remained significantly elevated after blood reinfusion. Significant correlations were found between base deficit and PeCO2–PaCO2 (P < 0.002) and PeCO2 (P < 0.022). Blood bicarbonate concentration decreased significantly following mild and severe hemorrhage, but its recovery was not complete at 60 min after blood reinfusion.

Conclusion
Esophageal–arterial PCO2 gap increases during graded hemorrhagic hypotension and returns to baseline value after resuscitation without complete reversal of the base deficit. These data suggest that esophageal capnometry could be used as an alternative for gastric tonometry during management of hypovolemic shock.
Clinical effects of sexual abuse on people with learning disability
Authors: Sequeira Heather , Hollins Sheila 
Published: January 2003

BackgroundThere are few publications concerning the psychological reactions of people with learning disabilities to sexual abuse. Most significantly, there are no controlled studies and few which demonstrate a systematic approach to documenting the sequelae of trauma.AimsTo critically review the published research in this field.MethodA literature search in peer-reviewed psychiatry, psychology nursing and social care journals for the years 1974 to 2001 was conducted and 25 studies were reviewed.ResultsSeveral studies suggest that, following sexual abuse, people with learning disabilities may experience a range of psychopathology similar to that experienced by adults and children in the general population. However, because of methodological limitations, these results are not conclusive.ConclusionsWhether people with learning disabilities experience reactions to sexual abuse similar to the general population has yet to be explored by systematic research.
Impact of the ICD–10 Primary Health Care (PHC) diagnostic and management guidelines for mental disorders on detection and outcome in primary care
Authors: Croudace Tim , Evans Jonathan , Harrison Glynn , Sharp Deborah J. , Wilkinson Ellen , McCann Gemma , Spence Mathew , Crilly Catherine , Brindle Lucy 
Published: January 2003

BackgroundThe World Health Organization (WHO) ICD–10 Primary Health Care (PHC) Guidelines for Diagnosis and Management of Mental Disorders (1996) have not been evaluated in a pragmatic randomised controlled trial (RCT).AimsTo evaluate the effect of local adaptation and dissemination of the guidelines.MethodPragmatic, pair-matched, cluster RCT involving 30 practices.ResultsGuideline practices were less sensitive but more specific in identifying morbidity, but these differences were not significant. Guideline patients did not differ from usual-care patients on 12-item General Health Questionnaire scores at 3-month follow-up or in the proportion who were still cases. There were no significant differences in secondary outcomes.ConclusionsAttempts to influence clinician behaviour through a process of adaptation and extension of guidelines are unlikely to change detection rates or outcomes.
Death rate from ischaemic heart disease in Western Australian psychiatric patients 1980–1998
Authors: Lawrence David M. , D'Arcy Cashel , Holman J. , Jablensky Assen V. , Hobbs Michael S. T. 
Published: January 2003

BackgroundPeople with mental illness suffer excess mortality due to physical illnesses.AimsTo investigate the association between mental illness and ischaemic heart disease (IHD) hospital admissions, revascularisation procedures and deaths.MethodA population-based record-linkage study of 210 129 users of mental health services in Western Australia during 1980–1998. IHD mortality rates, hospital admission rates and rates of revascularisation procedures were compared with those of the general population.ResultsIHD (not suicide) was the major cause of excess mortality in psychiatric patients. In contrast to the rate in the general population, the IHS mortality rate in psychiatric patients did not diminish over time. There was little difference in hospital admission rates for IHD between psychiatric patients and the general community, but much lower rates of revascularisation procedures with psychiatric patients, particularly in people with psychoses.ConclusionsPeople with mental illness do not receive an equitable level of intervention for IHD. More attention to their general medical care is needed.