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1.
Prev Vet Med ; 81(1-3): 117-34, 2007 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17482298

RESUMO

Surveillance information is most useful when provided within a risk framework, which is achieved by presenting results against an appropriate denominator. Often the datasets are captured separately and for different purposes, and will have inherent errors and biases that can be further confounded by the act of merging. The United Kingdom Rapid Analysis and Detection of Animal-related Risks (RADAR) system contains data from several sources and provides both data extracts for research purposes and reports for wider stakeholders. Considerable efforts are made to optimise the data in RADAR during the Extraction, Transformation and Loading (ETL) process. Despite efforts to ensure data quality, the final dataset inevitably contains some data errors and biases, most of which cannot be rectified during subsequent analysis. So, in order for users to establish the 'fitness for purpose' of data merged from more than one data source, Quality Statements are produced as defined within the overarching surveillance Quality Framework. These documents detail identified data errors and biases following ETL and report construction as well as relevant aspects of the datasets from which the data originated. This paper illustrates these issues using RADAR datasets, and describes how they can be minimised.


Assuntos
Bases de Dados Factuais/normas , Controle de Qualidade , Medição de Risco , Animais , Interpretação Estatística de Dados , Gestão de Riscos , Reino Unido
2.
J Wildl Dis ; 41(2): 317-25, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16107666

RESUMO

Conjunctivitis in house finches (Carpodacus mexicanus), caused by Mycoplasma gallisepticum (MG), was first reported in 1994 and, since this time, has become endemic in house finch populations throughout eastern North America. Although the house finch is most commonly associated with MG-related conjunctivitis, MG has been reported from other wild bird species, and conjunctivitis (not confirmed as MG related) has been reported in over 30 species. To help define the host range of the house finch strain of MG and to better understand the effect of MG on other host species, we monitored a community of wild birds for exposure to MG and conducted experimental infections on nine avian species. For the field portion of our study, we conducted a 9-mo survey (August 2001 to April 2002) of wild avian species in a peri-urban environment on the campus of Auburn University. During this time 358 birds, representing 13 different families, were sampled. No clinical signs of mycoplasmosis were observed in any bird. Thirteen species from nine families had positive agglutination reactions for antibodies to MG, but all birds tested negative by polymerase chain reaction (PCR). Three mourning doves were PCR-positive for MG, but antibodies to MG were not detected. In the experimental infections, we exposed seven native avian species and two cage-bird species to MG (May 2000 to June 2002). After exposure, clinical disease was seen in all four species from the family Fringillidae and in eastern tufted titmice (Baeolophus bicolor). In addition, three other species were infected without clinical signs, suggesting that they may represent potential MG reservoirs.


Assuntos
Doenças das Aves/epidemiologia , Conjuntivite Bacteriana/veterinária , Tentilhões , Infecções por Mycoplasma/veterinária , Mycoplasma gallisepticum/imunologia , Aves Canoras , Animais , Animais Selvagens , Anticorpos Antibacterianos/sangue , Doenças das Aves/imunologia , Doenças das Aves/microbiologia , Conjuntivite Bacteriana/epidemiologia , Conjuntivite Bacteriana/imunologia , Suscetibilidade a Doenças/veterinária , Feminino , Masculino , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/imunologia , Reação em Cadeia da Polimerase/veterinária , Estudos Soroepidemiológicos , Especificidade da Espécie
3.
Avian Dis ; 49(1): 92-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15839419

RESUMO

Pigeon paramyxovirus-1 (PPMV-1) was isolated from pigeons from east-central Alabama and used in association with chicken anemia virus (CAV), infectious bursal disease virus (IBDV), or finch Mycoplasma gallisepticum (MG) in specific-pathogen-free chickens to assess dinical disease and pathology. PPMV-1 infection in all groups was conducted at day 10 of age via the ocular route. The low passage PPMV-1 isolate was inoculated into chickens in different groups at 10 days post-CAV infection, 6 days post-IBDV infection, and 6 days post-finch MG infection, respectively. Additionally, to obtain information on the status of paramyxovirus infection in the wild bird population of the region, we used a multispecies competitive enzyme-linked immunosorbent assay kit to assess serum samples from 180 wild birds representing 24 species obtained throughout 2001. Mild respiratory signs characterized by sneezing were observed in PPMV-1-infected chicks. In the brain, PPMV-1 caused disseminated vasculitis in the neuropile and meninges, sometimes with small foci of gliosis. Most brains had only mild lesions. In the upper respiratory tract, lesions were confined to the larynx and proximal trachea as hyperplasia of laryngeal mucosa-associated lymphoid tissue. In the lung, PPMV-1 caused minimal to moderate multifocal interstitial pneumonia. Lymphocytic expansion occurred in the interstitium of the Harderian gland. PPMV-1 in the spleen caused expansion of the white pulp as a result of hypertrophy of the macrophages in the periarteriolar sheaths accompanied by lymphocytic hyperplasia at the periphery. No severe aggravation of either signs or lesions could be attributed to any of the avian pathogens used in association with PPMV-1. The serologic survey in wild birds showed antibody levels that were considered negative or doubtful. Interestingly, significantly (P < 0.05) higher mean titers were observed during the months of October and November 2001, following closely multiple PPMV-1 episodes of mortality in wild collard doves in northwestern Florida.


Assuntos
Avulavirus , Galinhas/virologia , Passeriformes/virologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Viroses/veterinária , Alabama , Animais , Encéfalo/patologia , Encéfalo/virologia , Vírus da Anemia da Galinha , Columbidae/virologia , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Doença Infecciosa da Bursa , Mycoplasma gallisepticum , Vírus da Doença de Newcastle , Sistema Respiratório/patologia , Sistema Respiratório/virologia , Testes Sorológicos/veterinária , Organismos Livres de Patógenos Específicos , Viroses/patologia
4.
Avian Dis ; 47(3): 640-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14562892

RESUMO

Mycoplasma gallisepticum, a major pathogen of chickens and turkeys, has caused significant declines in house finch (Carpodacus mexicanus) populations in the eastern United States since it was first observed in this species in 1994. There is evidence that M. gallisepticum infection is now endemic among eastern house finches, although disease prevalence has declined, suggesting an evolving host-parasite relationship. Studies based on randomly amplified polymorphic DNA (RAPD) have documented the presence of a single, unique RAPD profile in house finch M. gallisepticum isolates, suggesting a single point source of origin, which agrees with the known epidemiologic observations. In the present study, we evaluated the molecular variability of 55 house finch isolates as well as 11 chicken and turkey isolates including reference strains of M. gallisepticum. Molecular variability was evaluated by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis and nucleotide sequencing of the pvpA gene, which encodes for the putative cytadhesin protein PvpA. Three different RFLP groups and 16 genotypes were evident from the 55 house finch isolates evaluated. Sequence analysis of pvpA gene PCR products showed that although most house finch M. gallisepticum isolates clustered more closely to each other, others clustered more closely to either turkey or chicken field isolates. These findings suggest that house finch isolates are more polymorphic than previously recognized by RAPD studies. This feature may allow us to learn more about the molecular evolution and epidemiology of this emerging disease host-parasite relationship.


Assuntos
Adesinas Bacterianas/genética , Variação Genética , Mycoplasma gallisepticum/genética , Aves Canoras/microbiologia , Adesinas Bacterianas/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Galinhas , DNA Bacteriano/química , Genótipo , Mycoplasma gallisepticum/classificação , Filogenia , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Técnica de Amplificação ao Acaso de DNA Polimórfico/veterinária , Alinhamento de Sequência/veterinária , Análise de Sequência de DNA/veterinária , Perus
5.
Ann Thorac Surg ; 72(3): 953-4, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11565702

RESUMO

Postinfarction left ventricular thrombi are at risk for embolization with resultant injury. Surgical removal is recommended especially if they are pedunculated or mobile. We describe an easily applied transatrial method that can allow avoidance of a ventriculotomy.


Assuntos
Cardiopatias/cirurgia , Trombectomia/métodos , Trombose/cirurgia , Feminino , Cardiopatias/diagnóstico por imagem , Ventrículos do Coração , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Radiografia , Trombose/diagnóstico por imagem
6.
Avian Dis ; 45(1): 70-5, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11332501

RESUMO

Since 1995, the epidemic of mycoplasmal conjunctivitis in eastern house finches has affected the Auburn, AL, house finch population. To better characterize the current status of this host-parasite interaction, we established a captive flock of 38 seronegative, healthy finches in fall 1998. After a minimum quarantine period of 4 wk, two Mycoplasma gallisepticum (MG)-infected house finches were introduced into this flock. Over a 12-wk period, the flock was captured every 2 wk and each bird was observed for conjunctivitis. Blood and choanal swabs were collected from each bird for serologic analysis and for the detection of MG by polymerase chain reaction. The infection spread rapidly through the flock just as it had in a similar study performed in 1996 at the height of the epidemic. Unlike the earlier study in which birds remained chronically infected, most of the birds in our study recovered rapidly, and only three of the birds died during the study. Two patterns of host response to infection with MG were observed. Twenty-seven birds (73%) experienced an acute conjunctivitis that resolved, and the birds appeared to clear the infection. Ten birds (27%) suffered prolonged clinical disease, and MG could be detected in these birds intermittently throughout the experiment. These results, in conjunction with our surveys of MG in the wild population, suggest an evolving host-parasite interaction.


Assuntos
Doenças das Aves/microbiologia , Conjuntivite/veterinária , Surtos de Doenças/veterinária , Infecções por Mycoplasma/veterinária , Mycoplasma/patogenicidade , Doença Aguda , Adaptação Fisiológica , Alabama/epidemiologia , Animais , Animais de Zoológico , Conjuntivite/microbiologia , Infecções por Mycoplasma/microbiologia , Aves Canoras
9.
Ann Thorac Surg ; 71(2 Suppl): S19-21, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11235767

RESUMO

BACKGROUND: Of 5,812 persons boarded by the American Board of Thoracic Surgery (ABTS), 99 (< 2%) are women. This study was designed to collect and report the contributions made by these women in the specialty of cardiothoracic surgery. METHODS: Identification of ABTS board-certified women was obtained from the ABTS. Compilation of data was accomplished through membership databases, medical licensing boards, thoracic surgery residency programs, and residency program attending surgeons. Data were substantiated through hospital medical staff offices, local practitioners, and personal telephone calls. Curricula vitae were requested; practice types (adult, pediatric, cardiac, general thoracic, or transplantation) were established. Data were collated, extrapolated, and tallied. Trends over time were analyzed by logistic regression analyses. RESULTS: Currently, 84 women are actively practicing: 44 have academic appointments and 40 are in private practice. Of the remaining 15 women, 4 are deceased; 4 are retired; 5 are in other professional fields; and 2 are in an unknown practice setting. Accumulated data confirmed that women surgeons are practicing in every type and subgroup of cardiothoracic surgery (adult, pediatric, cardiac, general thoracic, transplantation, and combinations of these). Collectively, they have published 2,292 articles and book chapters. Manuscripts directly related to cardiac topics number 1,220. Women in cardiothoracic surgical research have been awarded $31.9 million in grant funds. Two trends over time were identified. First, the distribution of practice setting (academic or private) was stable compared with year of board certification. Secondly, a statistically significant rise in the annual percentage of board-certified persons who are women (p < 0.0001) has been established. CONCLUSIONS: The percent of ABTS board-certified women surgeons has increased; more than 50% have academic appointments; and a stable trend for women to choose academic cardiothoracic surgery exists.


Assuntos
Médicas/provisão & distribuição , Cirurgia Torácica , Educação Médica , Feminino , História do Século XX , Humanos , Médicas/história , Área de Atuação Profissional , Pesquisa , Conselhos de Especialidade Profissional/estatística & dados numéricos , Cirurgia Torácica/história , Recursos Humanos
10.
J Appl Physiol (1985) ; 90(4): 1385-91, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11247938

RESUMO

Ca2+ signaling forms part of a possible mechanotransduction pathway by which chondrocytes may alter their metabolism in response to mechanical loading. In this study, a well-characterized model system utilizing bovine articular chondrocytes embedded in 4% agarose constructs was used to investigate the effect of physiological mechanical compressive strain applied after 1 and 3 days in culture. The intracellular Ca2+ concentration was measured by use of the ratiometric Ca2+ indicator indo 1-AM and confocal microscopy. A positive Ca2+ response was defined as a percent increase in Ca2+ ratio above a preset threshold. A significantly greater percentage of cells exhibited a positive Ca2+ response in strained constructs compared with unstrained controls at both time points. In strained constructs, treatment with either Ga3+ or EGTA significantly reduced the number of positive Ca2+ responders compared with untreated controls. These results represent an important step in understanding the physiological role of intracellular Ca2+ in chondrocytes under mechanical compression.


Assuntos
Sinalização do Cálcio/fisiologia , Condrócitos/fisiologia , Algoritmos , Animais , Bovinos , Células Cultivadas , Espaço Extracelular/fisiologia , Processamento de Imagem Assistida por Computador , Masculino , Mecanorreceptores/fisiologia , Microscopia Confocal , Estimulação Física , Sefarose
11.
J Wildl Dis ; 37(1): 82-8, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11272508

RESUMO

An epidemiological study of the prevalence of mycoplasmal conjunctivitis in the house finch (Carpodacus mexicanus) was conducted in Auburn (Alabama, USA) between March 1998 and February 1999. Clinical disease was observed in 4% of the 1,214 finches trapped and examined. This rate is comparable to the average annual prevalence observed in this population since 1996, although the prevalence of clinical disease observed in the peak months of September through November was lower than in previous years. Clinically ill birds were observed in all months of the study. To estimate the prevalence of recovering and asymptomatic, infected birds, we tested a subset of 334 house finches serologically for exposure to Mycoplasma gallisepticum (MG) using the serum plate agglutination (SPA) assay. The prevalence of clinical disease in this subsample was slightly higher (7%) than in the entire sample, reflecting the fact that the serological survey was initiated in the late summer when the prevalence of MG infection peaks in our study population and a sampling bias for symptomatic birds. The serological survey indicated that 13% of this subpopulation had been exposed to MG. We also tested 46 of 334 finches by polymerase chain reaction (PCR) to detect MG in seropositive, asymptomatic birds. Use of the PCR in conjunction with the SPA detected six asymptomatic, infected birds that may represent potential carriers or birds in the early stages of infection. The decreasing prevalence of clinical disease observed during the peak months suggests a changing host-parasite relationship. Continued surveillance of this population, employing both clinical observation and serological analysis will be useful in characterizing these changes over time.


Assuntos
Doenças das Aves/epidemiologia , Conjuntivite/veterinária , Infecções por Mycoplasma/veterinária , Animais , Conjuntivite/epidemiologia , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/transmissão , Aves Canoras , Sudeste dos Estados Unidos/epidemiologia
12.
Ann Thorac Surg ; 69(1): 146-50, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10654504

RESUMO

BACKGROUND: Health care reform, public disclosure of hospital and surgeon-specific results, plus changes in reimbursement patterns have raised the specter of volume-based credentialing. METHODS: Using The Society of Thoracic Surgeons Cardiac Database, we examined the data for all coronary artery bypass graft-only patients (n = 615) operated on by us from July 1991 to June 1997. RESULTS: The observed mortality was 0.33% and the observed-to-expected ratio was 0.12 (p<0.005). Morbidity was low as well. CONCLUSIONS: Excellent results can be obtained for patients undergoing coronary artery bypass grafting in the presence of both low surgeon and low hospital case volume.


Assuntos
Ponte de Artéria Coronária/estatística & dados numéricos , Credenciamento , Hospitais Rurais , Qualidade da Assistência à Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Ponte Cardiopulmonar , Ponte de Artéria Coronária/efeitos adversos , Ponte de Artéria Coronária/mortalidade , Ponte de Artéria Coronária/normas , Doença das Coronárias/diagnóstico , Doença das Coronárias/cirurgia , Bases de Dados como Assunto , Feminino , Parada Cardíaca Induzida , Mortalidade Hospitalar , Hospitais Rurais/normas , Humanos , Masculino , Pessoa de Meia-Idade , Missouri/epidemiologia , Estudos de Casos Organizacionais , Esterno/cirurgia , Taxa de Sobrevida , Toracotomia
13.
Avian Dis ; 44(4): 948-52, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11195652

RESUMO

Since the beginning of an epidemic of conjunctivitis in wild house finches caused by Mycoplasma gallisepticum (MG), all captive colonies established by capturing free-ranging house finches from the eastern population have also either been infected at the time of capture or developed infection shortly after capture. In an attempt to avoid this infection in captive flocks being maintained for studies of the finches' behavior and ecology, we compared two different flock management strategies and were able to prevent the development of mycoplasmal conjunctivitis with one of the strategies. Single-sex flocks were built by introducing only seronegative wild-caught birds showing no clinical signs of conjunctivitis and covering their outdoor flight cages with netting to prevent interaction with other wild birds although only the female flocks were initially treated with a 6-wk course of tylosin tartrate (0.3 mg/ml). The female flocks never developed conjunctivitis although the disease did develop in the male flocks. Furthermore, serologic assessments of the healthy flock by serum plate agglutination assays for MG indicated that the females remained free of MG infection in the final 7 wk of the study, during which they were unmedicated. We conclude that any low-level MG infection not diagnosed by the initial test for seroconversion was cleared by the prolonged drug treatment.


Assuntos
Doenças das Aves/virologia , Conjuntivite Viral/veterinária , Infecções por Mycoplasma/veterinária , Aves Canoras/crescimento & desenvolvimento , Criação de Animais Domésticos , Animais , Doenças das Aves/prevenção & controle , Conjuntivite Viral/prevenção & controle , Conjuntivite Viral/virologia , Feminino , Masculino , Mycoplasma , Infecções por Mycoplasma/prevenção & controle , Infecções por Mycoplasma/virologia , Caracteres Sexuais , Aves Canoras/virologia , Tilosina/uso terapêutico
14.
JAMA ; 281(11): 984; author reply 985, 1999 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-10086426
15.
J Virol ; 72(4): 2871-80, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9525607

RESUMO

The respiratory syncytial virus (RSV) G glycoprotein promotes differentiation of type 2 CD4+ T lymphocytes and induces an eosinophilic response in lungs of RSV-infected mice. A unique feature of G is that a second initiation codon in the transmembrane region of the glycoprotein results in secretion of soluble protein from infected cells. Recombinant vaccinia viruses that express wild-type G (vvWT G), only secreted G (vvM48), or only membrane-anchored G (vvM48I) were used to define the influence of G priming on immunopathogenesis. Mice immunized with vvM48 had more severe illness following RSV challenge than did mice primed with vvWT G or vvM48I. Coadministration of purified G during priming with the construct expressing membrane-anchored G shifted immune responses following RSV challenge to a more Th2-like response. This was characterized by increased interleukin-5 in lung supernatants and an increase in G-specific immunoglobulin G1 antibodies. Eosinophils were present in the infiltrate of all mice primed with G-containing vectors but were greatest in mice primed with regimens including secreted G. These data suggest the form of G protein available for initial antigen processing and presentation is an important factor in promoting Th2-like immune responses, including the induction of lung eosinophilia. The ability of RSV to secrete G protein may therefore represent a viral strategy for immunomodulation and be a key determinant of disease pathogenesis.


Assuntos
Eosinofilia/imunologia , Proteína HN , Interleucina-5/biossíntese , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sincicial Respiratório Humano/imunologia , Vacinas Sintéticas/imunologia , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Lavagem Broncoalveolar , Linhagem Celular , Humanos , Imunoglobulina G/imunologia , Interferon gama/biossíntese , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/fisiologia , Células Tumorais Cultivadas , Proteínas do Envelope Viral , Proteínas Virais/biossíntese , Replicação Viral , Redução de Peso
16.
Virology ; 231(1): 48-58, 1997 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-9143302

RESUMO

Bovine respiratory syncytial (BRS) virus can be divided into antigenic subgroups based on the reactivity of monoclonal antibodies (mAbs) to the attachment glycoprotein, G. Further, the polyclonal antibody response of calves vaccinated with recombinant vaccinia viruses expressing the G protein of a particular subgroup is also subgroup-specific. To investigate the genetic basis for the antigenic heterogeneity of the BRS virus G protein, the genes for the G protein from 6 BRS virus strains representative of the antigenic subgroups were cloned, sequenced, and compared with the prototype subgroup A strain, 391-2. There was only 10% nucleic acid difference and 15% amino acid difference between strains from different subgroups. These findings are in sharp contrast to the situation with human RS virus, where there is a 45% difference in amino acid identity between subgroups. In fact, the extent of amino acid difference between BRS virus subgroups is similar to the level of heterogeneity observed within human subgroups. Analysis of the reactivity of mAbs with peptides from the cysteine-rich region (174-188) of the G protein representing each antigenic subgroup indicated that amino acids at positions 180, 183, and possibly 184 are important in subgroup distinction. Taken together, these data suggest that although the genetic variation responsible for the antigenic differences determining subgroups among BRS viruses is more limited than that observed among human RS virus subgroups, the amino acid differences that exist have a profound effect upon antibody recognition.


Assuntos
Vírus Sincicial Respiratório Bovino/genética , Proteínas do Envelope Viral/genética , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Sítios de Ligação de Anticorpos , Bovinos , Camundongos , Dados de Sequência Molecular , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Bovino/imunologia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia
17.
J Gen Virol ; 77 ( Pt 1): 109-18, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8558117

RESUMO

The attachment protein G of human respiratory syncytial (RS) virus is a type II transmembrane glycoprotein. A secreted from of the G protein is also produced. To examine the two distinct hydrophobic regions in the N-terminal 63 amino acids of G protein for their role(s) in membrane insertion and anchoring, transport to the cell surface, and secretion, G proteins that contained point mutations or deletions were synthesized by cell-free transcription-translation and in cells by expression from recombinant vaccinia virus vectors. A mutant protein lacking the entire major hydrophobic region (amino acids 38-63) was not glycosylated, not expressed on the cell surface, and not secreted, because it was not inserted into membranes. In contrast, deletion of the minor hydrophobic region (amino acids 23-31) had no detectable effect on membrane insertion or anchoring. These data provided direct evidence that amino acids 38-63 were necessary for membrane insertion and contained the signal/anchor domain of RS virus G protein. Mutant proteins that lacked either the N-terminal or the C-terminal half of this 26 residue hydrophobic region were inserted into membranes and processed to maturity, showing that either half of this region was sufficient for membrane insertion. However, these two mutant proteins were secreted more abundantly than wild-type G protein. We propose that their truncated hydrophobic domains interacted with membranes in a way that mimicked the N-terminal signal sequence of naturally secreted proteins, allowing proteolytic cleavage of the mutant proteins.


Assuntos
Proteína HN , Vírus Sincicial Respiratório Humano/fisiologia , Proteínas Virais de Fusão/fisiologia , Proteínas Virais/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Sistema Livre de Células , Endopeptidases/metabolismo , Vetores Genéticos , Células HeLa , Humanos , Fusão de Membrana , Microscopia de Fluorescência , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oligodesoxirribonucleotídeos , Coelhos , Proteínas Recombinantes , Vírus Sincicial Respiratório Humano/genética , Células Tumorais Cultivadas , Vaccinia virus/genética , Proteínas do Envelope Viral , Proteínas Virais de Fusão/genética , Proteínas Virais/genética
18.
J Virol ; 69(4): 2667-73, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7884920

RESUMO

Respiratory syncytial (RS) virus infects the epithelium of the respiratory tract. We examined the replication and maturation of RS virus in two polarized epithelial cell lines, Vero C1008 and MDCK. Electron microscopy of RS virus-infected Vero C1008 cells revealed the presence of pleomorphic viral particles budding exclusively from the apical surface, often in clusters. The predominant type of particle was filamentous, 80 to 100 nm in diameter, and 4 to 8 microns in length, and evidence from filtration studies indicated that the filamentous particles were infectious. Cytopathology produced by RS virus infection of polarized Vero C1008 cells was minimal, and syncytia were not observed, consistent with the maintenance of tight junctions and the exclusively apical maturation of the virus. Infectivity assays with MDCK cells confirmed that in this cell line, RS virus was released into the apical medium but not into the basolateral medium. In addition, the majority of the RS virus transmembrane fusion glycoprotein on the cell surface was localized to the apical surface of the Vero C1008 cells. Taken together, these results demonstrate that RS virus matures at the apical surface of polarized epithelial cell lines.


Assuntos
Epitélio/virologia , Vírus Sinciciais Respiratórios/fisiologia , Animais , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/virologia , Chlorocebus aethiops , Cães , Células Gigantes , Glicoproteínas de Membrana/metabolismo , Microscopia Eletrônica , Microscopia de Fluorescência , Vírus Sinciciais Respiratórios/patogenicidade , Células Vero
19.
J Virol ; 68(7): 4538-46, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8207828

RESUMO

Respiratory syncytial (RS) virus synthesizes two mature forms of its attachment glycoprotein G: an anchored type II integral membrane form and a smaller form that is secreted into the medium. Here we demonstrate that these two forms are synthesized as distinct primary translation products of a single species of G protein mRNA by initiation at either of two different AUGs. Mutant cDNAs which eliminated one of the other of the two AUG codons near the 5' end of the G gene open reading frame were constructed. Analysis of the proteins synthesized from these cDNAs, either by translation of transcripts in a cell-free system or in cells infected with recombinant vaccinia viruses containing either one of the mutant cDNAs, showed that elimination of either the first or the second of these AUG codons abrogated the synthesis of the membrane-anchored or the secreted form of the protein, respectively. Additionally, two unglycosylated forms of G protein which comigrated with the unglycosylated G proteins expressed by these recombinant viruses were detected in RS virus-infected cells. Since the second AUG encodes a methionine residue that lies near the middle of the signal/anchor domain, initiation at this codon resulted in a protein with a hydrophobic amino terminus. This form of the glycoprotein was efficiently secreted from cells infected with the vaccinia virus recombinant, and the amino-terminal sequence of this protein was identical to that of G protein secreted from RS virus-infected cells. Our results demonstrate that the secreted form of RS virus G protein is produced by initiation at the second AUG codon of the G open reading frame, followed by proteolytic removal of the signal/anchor domain.


Assuntos
Códon , Proteína HN , Vírus Sinciciais Respiratórios/metabolismo , Proteínas Virais/biossíntese , Sequência de Aminoácidos , Sequência de Bases , Membrana Celular/metabolismo , Sistema Livre de Células , Células Cultivadas , DNA Viral , Glicosilação , Dados de Sequência Molecular , Biossíntese de Proteínas , RNA Mensageiro/genética , Proteínas do Envelope Viral , Proteínas Virais/genética
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