bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross-Packaging of a Single Adeno-Associated Virus (AAV) Type 2 Vector Genome into Multiple AAV Serotypes Enables Transduction with Broad Specificity
Authors: Rabinowitz Joseph E. , Rolling Fabienne , Li Chengwen , Conrath Hervè , Xiao Weidong , Xiao Xiao , Samulski R. Jude 
Published: July 2002

ABSTRACT

The serotypes of adeno-associated virus (AAV) have the potential to become important resources for clinical gene therapy. In an effort to compare the role of serotype-specific virion shells on vector transduction, we cloned each of the serotype capsid coding domains into a common vector backbone containing AAV type 2 replication genes. This strategy allowed the packaging of AAV2 inverted terminal repeat vectors into each serotype-specific virions. Each of these helper plasmids (pXR1 through pXR5) efficiently replicated the transgene DNA and expressed helper proteins at nearly equivalent levels. In this study, we observed a correlation between the amount of transgene replication and packaging efficiency. The physical titer of these hybrid vectors ranged between 1.3 × 10
11
and 9.8 × 10
12
/ml (types 1 and 2, respectively). Of the five serotype vectors, only types 2 and 3 were efficiently purified by heparin-Sepharose column chromatography, illustrating the high degree of similarity between these virions. We analyzed vector transduction in reference and mutant Chinese hamster ovary cells deficient in heparan sulfate proteoglycan and saw a correlation between transduction and heparan sulfate binding data. In this analysis, types 1 and 5 were most consistent in transduction efficiency across all cell lines tested. In vivo each serotype was ranked after comparison of transgene levels by using different routes of injection and strains of rodents. Overall, in this analysis, type 1 was superior for efficient transduction of liver and muscle, followed in order by types 5, 3, 2, and 4. Surprisingly, this order changed when vector was introduced into rat retina. Types 5 and 4 were most efficient, followed by type 1. These data established a hierarchy for efficient serotype-specific vector transduction depending on the target tissue. These data also strongly support the need for extending these analyses to additional animal models and human tissue. The development of these helper plasmids should facilitate direct comparisons of serotypes, as well as begin the standardization of production for further clinical development.
NS1 Protein of Influenza A Virus Down-Regulates Apoptosis
Authors: Zhirnov O. P. , Konakova T. E. , Wolff T. , Klenk H.-D. 
Published: July 2002

ABSTRACT
Wild-type (WT) influenza A/PR/8/34 virus and its variant lacking the NS1 gene (delNS1) have been compared for their ability to mediate apoptosis in cultured cells and chicken embryos. Cell morphology, fragmentation of chromatin DNA, and caspase-dependent cleavage of the viral NP protein have been used as markers for apoptosis. Another marker was caspase cleavage of the viral M2 protein, which was also found to occur in an apoptosis-specific manner. In interferon (IFN)-competent host systems, such as MDCK cells, chicken fibroblasts, and 7-day-old chicken embryos, delNS1 virus induced apoptosis more rapidly and more efficiently than WT virus. As a consequence, delNS1 virus was also more lethal for chicken embryos than WT virus. In IFN-deficient Vero cells, however, apoptosis was delayed and developed with similar intensity after infection with both viruses. Taken together, these data indicate that the IFN antagonistic NS1 protein of influenza A viruses has IFN-dependent antiapoptotic potential.
Virion Disassembly Is Required for Apoptosis Induced by Reovirus
Authors: Connolly Jodi L. , Dermody Terence S. 
Published: July 2002

ABSTRACTReovirus infection leads to apoptosis in cultured cells and in vivo. Binding of viral attachment protein ς1 to both sialic acid and junction adhesion molecule is required for induction of apoptosis. However, it is not known whether viral engagement of receptors is sufficient to elicit this cellular response. To determine whether steps in reovirus replication subsequent to viral attachment are required for reovirus-induced apoptosis, we used inhibitors of viral disassembly and RNA synthesis, viral disassembly intermediates, temperature-sensitive (ts) reovirus mutants, and reovirus particles deficient in genomic double-stranded RNA (dsRNA). We found that reovirus-induced apoptosis is abolished in the presence of the viral disassembly inhibitors ammonium chloride and E64. Infectious subvirion particles (ISVPs), which are intermediates in reovirus disassembly that can be generated in vitro by protease treatment, are capable of inducing apoptosis in the presence or absence of these inhibitors. Treatment of cells with the viral RNA synthesis inhibitor ribavirin does not diminish the capacity of reovirus to induce apoptosis, and reovirustsmutants arrested at defined steps in viral replication produce apoptosis with efficiency similar to that of wild-type virus. Furthermore, reovirus particles lacking dsRNA are capable of inducing apoptosis. Finally, we found that viral attachment and disassembly must occur within the same cellular compartment for reovirus to elicit an apoptotic response. These results demonstrate that disassembly of reovirus virions to form ISVPs, but not viral transcription or subsequent steps in viral replication, is required for reovirus to induce apoptosis.
Positively Charged Amino Acid Substitutions in the E2 Envelope Glycoprotein Are Associated with the Emergence of Venezuelan Equine Encephalitis Virus
Authors: Brault Aaron C. , Powers Ann M. , Holmes Edward C. , Woelk C. H. , Weaver Scott C. 
Published: July 2002

ABSTRACT
Epidemic-epizootic Venezuelan equine encephalitis (VEE) viruses (VEEV) have emerged repeatedly via convergent evolution from enzootic predecessors. However, previous sequence analyses have failed to identify common sets of nucleotide or amino acid substitutions associated with all emaergence events. During 1993 and 1996, VEEV subtype IE epizootics occurred on the Pacific Coast of the states of Chiapas and Oaxaca in southern Mexico. Like other epizootic VEEV strains, when inoculated into guinea pigs and mice, the Mexican isolates were no more virulent than closely related enzootic strains, complicating genetic studies of VEE emergence. Complete genomic sequences of 4 of the Mexican strains were determined and compared to those of closely related enzootic subtype IE isolates from Guatemala. The epizootic viruses were less than 2% different at the nucleotide sequence level, and phylogenetic relationships confirmed that the equine-virulent Mexican strains probably evolved from enzootic progenitors on the Pacific Coast of Mexico or Guatemala. Of 35 amino acids that varied among the Guatemalan and Mexican isolates, only 8 were predicted phylogenetically to have accompanied the phenotypic change. One mutation at position 117 of the E2 envelope glycoprotein, involving replacement of Glu by Lys, resulted in a small-plaque phenotype characteristic of epizootic VEEV strains. Analysis of additional E2 sequences from representative enzootic and epizootic VEEV isolates implicated similar surface charge changes in the emergence of previous South American epizootic phenotypes, indicating that E2 mutations are probably important determinants of the equine-virulent phenotype and of VEE emergence. Maximum-likelihood analysis indicated that one change at E2 position 213 has been influenced by positive selection and convergent evolution of the epizootic phenotype.
Expression and Self-Assembly of Norwalk Virus Capsid Protein from Venezuelan Equine Encephalitis Virus Replicons
Authors: Baric Ralph S. , Yount Boyd , Lindesmith Lisa , Harrington Patrick R. , Greene Shermalyn R. , Tseng Fan-Chen , Davis Nancy , Johnston Robert E. , Klapper David G. , Moe Christine L. 
Published: July 2002

ABSTRACT
The Norwalk virus (NV) capsid protein was expressed using Venezuelan equine encephalitis virus replicon particles (VRP-NV1). VRP-NV1 infection resulted in large numbers of recombinant NV-like particles that were primarily cell associated and were indistinguishable from NV particles produced from baculoviruses. Mutations located in the N-terminal and P1 domains of the NV capsid protein ablated capsid self-assembly in mammalian cells.
Mutation of the Dominant Endocytosis Motif in Human Immunodeficiency Virus Type 1 gp41 Can Complement Matrix Mutations without Increasing Env Incorporation
Authors: West John T. , Weldon Sally K. , Wyss Stephanie , Lin Xiaoxu , Yu Qin , Thali Markus , Hunter Eric 
Published: July 2002

ABSTRACTThe human immunodeficiency virus type 1 transmembrane glycoprotein (TM) is efficiently endocytosed in a clathrin-dependent manner. Internalization is mediated by a tyrosine-containing motif within the cytoplasmic domain, and replacement of the cytoplasmic tyrosine by cysteine or phenylalanine increased expression of mutant glycoprotein on the surface of transfected cells by as much as 2.5-fold. Because interactions between the cytoplasmic domain of Env and the matrix protein (MA) have been suggested to mediate incorporation of Env in virus particles, we examined whether perturbation of endocytosis would alter incorporation. Proviruses were constructed to contain the wild-type or mutant Env in conjunction with point mutations in MA that had previously been shown to block Env incorporation. These constructs were used to evaluate the effect of glycoprotein endocytosis on incorporation into virus particles and to test the necessity for a specific interaction between Env and MA to mediate incorporation. Viruses produced from transfected 293T cells were used to infect various cell lines, including MAGI, H9, and CEMx174. Viruses encoding both a disrupted endocytosis motif signal and mutations within MA were significantly more infectious in MAGI cells than their counterparts encoding a mutant MA and wild-type Env. This complementation of infectivity for the MA incorporation mutant viruses was not due to increased glycoprotein incorporation into particles but instead reflected an enhanced fusogenicity of the mutated Env proteins. Our findings further support the concept that a specific interaction between the long cytoplasmic domain of TM and MA is required for efficient incorporation of Env into assembling virions. Alteration of the endocytosis signal of Env, and the resulting increase in cell surface glycoprotein, has no effect on incorporation despite demonstrable effects on fusion, virus entry, and infectivity.
Intrinsic Stability of Episomal Circles Formed during Human Immunodeficiency Virus Type 1 Replication
Authors: Pierson Theodore C. , Kieffer Tara L. , Ruff Christian T. , Buck Christopher , Gange Stephen J. , Siliciano Robert F. 
Published: July 2002

ABSTRACT

The development of surrogate markers capable of detecting residual ongoing human immunodeficiency virus type 1 (HIV-1) replication in patients receiving highly active antiretroviral therapy is an important step in understanding viral dynamics and in developing new treatment strategies. In this study, we evaluated the utility of circular forms of the viral genome for the detection of recent infection of cells by HIV-1. We measured the fate of both one-long terminal repeat (1-LTR) and 2-LTR circles following in vitro infection of logarithmically growing CD4
+
T cells under conditions in which cell death was not a significant contributing factor. Circular forms of the viral genome were found to be highly stable and to decrease in concentration only as a function of dilution resulting from cell division. We conclude that these DNA circles are not intrinsically unstable in all cell types and suggest that the utility of 2-LTR circle assays in measuring recent HIV-1 infection of susceptible cells in vivo needs to be reevaluated.
Incidence, site, and nature of injuries in amateur rugby league over three consecutive seasons
Authors: Gabbett Tim J 
Published: July 2002

Objectives—To report the incidence, site, and nature of injuries in amateur rugby league over three consecutive seasons.Methods—Six hundred players registered with an amateur rugby league organisation were studied over three consecutive seasons. All injuries sustained during the amateur rugby league matches were recorded. Information recorded included the date and time of injury, name of injured player, anatomical site and nature of injury, and position of the player.Results—The incidence of injury was 160.6 per 1000 player-position game hours, with forwards having a significantly higher incidence of injury than backs (182.3 per 1000v142.0 per 1000, χ2= 14.60, df = 1, p<0.001). Over 25% of the total injuries (40.6 per 1000) sustained during the three year period were to the head and neck, while injuries to the face (21.3 per 1000, 13.3%), abdomen and thorax (21.3 per 1000, 13.3%), and knee (17.8 per 1000, 11.1%) were less common (χ2= 21.83, df = 8, p<0.01). Muscular injuries (haematomas and strains) were the most common type of injury (45.7 per 1000, 28.5%, χ2= 17.98, df = 7, p<0.05). Significantly more injuries occurred in the latter stages of the season (χ2= 22.94, df = 1, p<0.001), with most injuries (70.8%, χ2= 162.29, df = 1, p<0.001) sustained in the second half of matches.Conclusions—The results show that muscular injuries and injuries to the head and neck are the most commonly sustained injuries in amateur rugby league. Furthermore, injuries are more often sustained in the latter stages of the season and during the second half of matches. These findings suggest that fatigue or accumulative microtrauma, or both, may contribute to injuries in amateur rugby league players.
“It's exercise or nothing”: a qualitative analysis of exercise dependence
Authors: Bamber D , Cockerill I M , Rodgers S , Carroll D 
Published: July 2002

Objectives—To explore, using qualitative methods, the concept of exercise dependence. Semistructured interviews were undertaken with subjects screened for exercise dependence and eating disorders.Methods—Female exercisers, four in each case, were allocated a priori to four groups: primary exercise dependent; secondary exercise dependent, where there was a coincidence of exercise dependence and an eating disorder; eating disordered; control, where there was no evidence of either exercise dependence or eating disorder. They were asked about their exercise and eating attitudes and behaviour, as well as about any history of psychological distress. Their narratives were taped, transcribed, and analysed from a social constructionist perspective using QSR NUD*IST.Results—Participants classified as primary exercise dependent either showed no evidence of exercise dependent attitudes and behaviour or, if they exhibited features of exercise dependence, displayed symptoms of an eating disorder. Only the latter reported a history of psychological distress, similar to that exhibited by women classified as secondary exercise dependent or eating disordered. For secondary exercise dependent and eating disordered women, as well as for controls, the narratives largely confirmed the a priori classification.Conclusions—Where exercise dependence was manifest, it was always in the context of an eating disorder, and it was this co-morbidity, in addition to eating disorders per se, that was associated with psychological distress. As such, these qualitative data support the concept of secondary, but not primary, exercise dependence.
Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players
Authors: Cook J L , Khan K M , Kiss Z S , Purdam C R , Griffiths L 
Published: July 2002

Background—Palpation is an important clinical test for jumper's knee.Objectives—To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality.Methods—In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively.Results—Patellar tendon palpation was a reliable examination for a single examiner (Pearsonr= 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36–38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (p<0.001). Tender and symptomatic tendons were more likely to have ultrasound abnormality than tenderness alone (p<0.01).Conclusions—In this age group, palpation is a reliable test but it is not cost effective in detecting patellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal.
Coeliac disease in the father affects the newborn
Authors: Ludvigsson J F , Ludvigsson J 
Published: July 2002

BACKGROUND AND AIMSUntreated coeliac disease in the mother is associated with lower birth weight. We examined the risk of adverse neonatal outcome when the infant's mother, father, or other relative suffered from known coeliac disease.METHODSMothers answered a questionnaire a few days after the birth of their infant. Of a total of 10597 single birth infants from Southeast Sweden, 53 infants had a mother with coeliac disease (father 27, sibling 70, other close relative 442). Adjusted odds ratios and adjusted differences for neonatal outcome were calculated.RESULTSInfants whose father suffered from coeliac disease had a lower birth weight (95% adjusted confidence interval (CI) −459, −72 g), more often belonged to the low birth weight (LBW) category (LBW ⩽2499 g) (95% CI adjusted odds ratio (AOR) 1.48–17.18), and had a shorter pregnancy duration (95% adjusted CI −1.53, −0.08 weeks) than non-coeliac controls. They also weighed less than infants whose father suffered from other autoimmune diseases (95% CI −549, −93 g). Infants whose mother suffered from coeliac disease had a lower birth weight (95% adjusted CI −370, −74 g) and more often belonged to the LBW category (95% CI AOR 2.60–15.08) than non-coeliac controls. These infants were more often in the LBW category than infants whose mother suffered from non-diabetic autoimmune diseases (95% CI AOR 1.24–9.65). Coeliac disease in other relatives was not associated with any adverse effect on neonatal outcome.CONCLUSIONSThis study suggests that even treated coeliac disease, in either of the parents, has a negative effect on pregnancy, resulting in lower birth weight and perhaps shorter duration of pregnancy.
Would you like to know what is wrong with you? On telling the truth to patients with dementia
Authors: Marzanski Marek 
Published: July 2002

Objectives—To discover what dementia sufferers feel is wrong with them; what they have been told and by whom, and what they wish to know about their illness.Background—Ethical guidelines regarding telling truth appear to be equivocal. Declarations of cognitively intact subjects, attitudes of family members and current psychiatric practice all vary, but no previous research has been published concerning what patients with dementia would in fact like to know about their diagnosis and prognosis.Design—Questionnaire study of the patients' opinions.Setting—Old Age Psychiatry Service in Worcester.Participants—30 consecutive patients with dementia.Results—The quality of information received has been poor and many patients have no opportunity to discuss their illness with anybody. Despite that almost half of the participants in this study had adequate insight and a majority declared that they would like to know more about their predicament.Conclusions—Although many patients would like to know the truth, the rights of those who do not want to know should also be respected. Therefore the diagnosis of dementia should not be routinely disclosed but (just as in other disorders) health care professionals should seek to understand their patients' preferences and act appropriately according to their choice.
Ethical dilemmas in palliative care: a study in Taiwan
Authors: Chiu Tai-Yuan , Hu Wen-Yu , Cheng Shao-Yi , Chen Ching-Yu 
Published: July 2002

Objectives—To investigate the incidence and solution of ethical dilemmas in a palliative care unit.Design—Health care workers recorded daily all dilemmas in caring for each patient.Setting—Palliative care unit of National Taiwan University Hospital in Taiwan.Patients—Two hundred and forty-six consecutive patients with terminal cancer during 1997-8.Main measurement—Ethical dilemmas in the questionnaire were categorised as follows: telling the truth; place of care; therapeutic strategy; hydration and nutrition; blood transfusion; alternative treatment; terminal sedation; use of medication, and others.Results—The type and frequency of ethical dilemmas encountered were: place of care (33.3%); truth-telling (32.1%); hydration and nutrition (25.2%); therapeutic strategy (24.8%), and use of medication (19.1%). Ethical problems relating to the place of care and to therapeutic strategy were unlikely to be solved with increased hospital stay and some ethical dilemmas remained unsolved even in the final week in hospital, including place of care (23.2%), truth-telling (17.1%) and therapeutic strategy (11.4%). Problems of truth-telling occurred in nearly half (42.6%) of patients over sixty-five-years-old. Conflicts about blood transfusion were experienced in all patients below 18-years-old, and the dilemmas concerning the place of care occurred most frequently with head and neck cancer patients (43.8%).Conclusions—The solution of ethical dilemmas required refocusing by medical professionals on the importance of continuing communication. Improved ethical training for professionals would contribute to solving the moral dilemmas of palliative care.