Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| fragmentation of a golgi-localized chimeric protein allows detergent solubilization and reveals an alternate conformation of the cytoplasmic domain. | golgi resident proteins maintain their localization despite a continual protein and lipid flux through the organelle. to study golgi retention mechanisms, we have focused upon the chimeric protein gm1. this protein contains the golgi transmembrane domain targeting signal from the infectious bronchitis virus m protein and the lumenal and cytoplasmic domain of the vesicular stomatitis virus glycoprotein (vsv g). the gm1 protein is targeted to the golgi where it forms an unusually stable detergent- ... | 1998 | 9425038 |
| comparison of the efficacies of three fluoroquinolone antimicrobial agents, given as continuous or pulsed-water medication, against escherichia coli infection in chickens. | this study compared the efficacy of continuous or pulsed-water medication with enrofloxacin, danofloxacin, and sarafloxacin in eight groups of 90 chicks each by using an infectious bronchitis virus-escherichia coli model of colisepticemia. the model produced lesions of typical those occurring in birds with severe colisepticemia; for the infected, nonmedicated birds the mortality was 43.5% and the morbidity was 89%, 17.8% of birds had severe lesions, and the birds had a mean air sac lesion score ... | 1998 | 9449265 |
| recombinant nucleocapsid protein is potentially an inexpensive, effective serodiagnostic reagent for infectious bronchitis virus. | the nucleocapsid protein of the gray strain of infectious bronchitis virus (ibv) is highly immunogenic and cross-reactive among various distinct serotypes. recombinant nucleocapsid polypeptide expressed in bacteria with a histidine tag at the amino terminus has been used as antigen for developing an assay to detect ibv-specific antibody. this fusion protein was produced readily in bacteria and easily purified with a nickel column which bound to the histidine tag. conditions were optimized for us ... | 1998 | 9506811 |
| detection and classification of infectious bronchitis viruses isolated in korea by dot-immunoblotting assay using monoclonal antibodies. | dot-immunoblotting assay (dia) using five monoclonal antibodies (mabs) to infectious bronchitis virus (ibv) was used to detect and classify the viruses propagated in embryonated chicken eggs. using a group-specific mab 3f5, 10 reference strains and 12 korean isolates of ibv were successfully detected by dia, and the lowest virus titer of ibv detected by dia was approximately less than 10(3.8) mean embryo infective dose/ml. for evaluating the diagnostic efficiency, dia was compared with the conve ... | 1998 | 9533085 |
| transmission of infectious bronchitis virus within vaccinated and unvaccinated groups of chickens. | the aim of this study was to determine whether vaccination against infectious bronchitis virus (ibv) reduces virus transmission, i.e. to test whether ibv transmission among vaccinated chickens is significantly reduced compared to that among unvaccinated chickens. in two vaccinated and two unvaccinated groups of spf chickens, a standard measure for virus transmission, the reproduction ratio (r) was determined. r is defined as the average number of new infections caused by one typical infectious i ... | 1998 | 18484273 |
| detection of specific igm antibodies to infectious bronchitis virus by an antibody-capture elisa. | the results of a new antibody-capture elisa (alpha-igm-ibv elisa), specific for igm directed against infectious bronchitis virus (ibv) show that this assay is a useful tool for diagnosing ibv infections. the data include individual results of the alpha-igm-ibv elisa in sequential spf chicken sera after vaccination with h120 and challenge with m41, the specificity is based on results of 499 spf sera, and the sensitivity on sera from experimentally vaccinated and challenged birds. also reported ar ... | 1998 | 18483980 |
| intracloacal infection with avian infectious bronchitis virus. | an infectious bronchitis virus (ibv) strain hs-91 isolated from kidneys of chicks which died of nephrosis was inoculated via the cloaca of specific pathogen-free (spf) chicks. these chicks showed more severe clinical signs, grosser kidney lesions and higher mortality than chicks inoculated with the same ibv strain via the trachea. | 1998 | 18484004 |
| epidemiological classification of infectious bronchitis virus isolated in korea between 1986 and 1997. | forty korean isolates and four reference strains of infectious bronchitis virus (ibv) were classified by reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism (rflp) analysis. each korean isolate was isolated from different types of commercial chicken flocks between 1986 and 1997. rflp patterns of an amplified dna fragment (1722 bp) containing the s1 gene of ibv digested by restriction enzyme haeiii showed that the 40 korean isolates were classified into fi ... | 1998 | 18484021 |
| development and application of an aerosol challenge method for reproduction of avian colibacillosis. | we have developed a reliable aerosol challenge method for reproduction of avian colibacillosis. this method involves intranasal administration of infectious bronchitis virus (ibv) to 1-day-old birds followed by three aerosol administrations of .e. coli at 3 to 4-day intervals. in four separate experiments there was no significant difference in virulence for a single isolate of .e. coli (e3) whereas four other field isolates of .e. coli ranged from highly virulent to avirulent. we also observed t ... | 1998 | 18484035 |
| antigenic and immunogenic characterization of infectious bronchitis virus strains isolated in china between 1986 and 1995. | eight strains of infectious bronchitis virus (ibv) were isolated between 1986 and 1995 from broilers and layers at eight different farms in four provinces in china. the viruses were isolated from flocks which suffered from either respiratory disease or nephritis and the majority had not been vaccinated against ibv. six strains were shown by monoclonal antibodies to differ from h120, connecticut and arkansas 99 strains of ibv and also to differ from each other. four of these strains were serotype ... | 1998 | 18484046 |
| a multiplex pcr for massachusetts and arkansas serotypes of infectious bronchitis virus. | infectious bronchitis virus (ibv), the prototype of the coronavirus family, is an enveloped, single-stranded rna virus with a genome size of approximately 27.6 kilobase. infectious bronchitis virus causes an acute, highly contagious respiratory and urogenital disease of chickens which results in significant economic losses in commercial broilers, layers and breeders. a rapid, highly sensitive and specific method is needed in the differential diagnosis of infections of different serotypes. a mult ... | 1999 | 10024427 |
| coronavirus pneumonia following autologous bone marrow transplantation for breast cancer. | infectious bronchitis virus, otherwise known as coronavirus, can cause mild upper respiratory tract illnesses in children and adults. rarely has coronavirus been linked, either by serology or nasal wash, to pneumonia. we report a case of a young woman who, following treatment for stage iiia breast cancer using a high-dose chemotherapy regimen followed by autologous bone marrow and stem cell transplantation, developed respiratory failure and was found to have coronavirus pneumonia as diagnosed by ... | 1999 | 10084516 |
| serological evidence for a 793/b related avian infectious bronchitis virus in india. | 1999 | 10204229 | |
| the role of rna pseudoknot stem 1 length in the promotion of efficient -1 ribosomal frameshifting. | the ribosomal frameshifting signal present in the genomic rna of the coronavirus infectious bronchitis virus (ibv) contains a classic hairpin-type rna pseudoknot that is believed to possess coaxially stacked stems of 11 bp (stem 1) and 6 bp (stem 2). we investigated the influence of stem 1 length on the frameshift process by measuring the frameshift efficiency in vitro of a series of ibv-based pseudoknots whose stem 1 length was varied from 4 to 13 bp in single base-pair increments. efficient fr ... | 1999 | 10329144 |
| evidence for an rna pseudoknot loop-helix interaction essential for efficient -1 ribosomal frameshifting. | rna pseudoknots are structural elements that participate in a variety of biological processes. at -1 ribosomal frameshifting sites, several types of pseudoknot have been identified which differ in their organisation and functionality. the pseudoknot found in infectious bronchitis virus (ibv) is typical of those that possess a long stem 1 of 11-12 bp and a long loop 2 (30-164 nt). a second group of pseudoknots are distinguishable that contain stems of only 5 to 7 bp and shorter loops. the nmr str ... | 1999 | 10329145 |
| health evaluation of free-ranging rockhopper penguins (eudyptes chrysocomes) in argentina. | as part of annual colony counts in santa cruz province, argentina, a health survey of rockhopper penguins (eudyptes chrysocomes) was conducted in 1994. forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. all birds appeared to be in good condition. no ecto- or endoparasites were found. hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. anti ... | 1999 | 10367640 |
| activity of a purified his-tagged 3c-like proteinase from the coronavirus infectious bronchitis virus. | previous studies in vitro of the processing of cloned polyprotein fragments from the coronavirus infectious bronchitis virus (ibv) large open reading frame (orf1), confirmed the activity of a predicted 3c-like proteinase (3clp) domain and suggested that the proteinase is released autocatalytically from the polyprotein in the form of a 35 kda protein, 3clpro, capable of further cleavages in trans. in order to identify such cleavages within the orf1 polyprotein mediated by 3clpro, the proteinase w ... | 1999 | 10392722 |
| phylogenetic analysis of a highly conserved region of the polymerase gene from 11 coronaviruses and development of a consensus polymerase chain reaction assay. | viruses in the genus coronavirus are currently placed in three groups based on antigenic cross-reactivity and sequence analysis of structural protein genes. consensus polymerase chain reaction (pcr) primers were used to obtain cdna, then cloned and sequenced a highly conserved 922 nucleotide region in open reading frame (orf) 1b of the polymerase (pol) gene from eight coronaviruses. these sequences were compared with published sequences for three additional coronaviruses. in this comparison, it ... | 1999 | 10392726 |
| sequence analysis of the matrix/nucleocapsid gene region of turkey coronavirus. | a reverse transcriptase, polymerase chain reaction (rt-pcr) procedure was used to amplify a segment of the genome of turkey coronavirus (tcv) spanning portions of the matrix and nucleocapsid (mn) protein genes (approximately 1.1 kb). the mn gene region of three epidemiologically distinct tcv strains (minnesota, nc95, indiana) was amplified, cloned into puc19, and sequenced. tcv mn gene sequences were compared with published sequences of other avian and mammalian coronaviruses. a high degree of s ... | 1999 | 10393500 |
| development of a nested pcr assay for the detection of canine coronavirus. | a diagnostic test for canine coronavirus (ccv) infection based on a nested polymerase chain reaction (n-pcr) assay was developed and tested using the following coronavirus strains: ccv (usda strain), ccv (45/93, field strain), feline infectious peritonitis virus (fipv, field strain), transmissible gastroenteritis virus (tgev, purdue strain), bovine coronavirus (bcv, 9wbl-77 strain), infectious bronchitis virus (ibv, m-41 strain) and fecal samples of dogs with ccv enteritis. a 230-bp segment of t ... | 1999 | 10403671 |
| a liquid phase blocking elisa for the detection of antibodies against infectious bronchitis virus. | a liquid phase blocking elisa (lpb-elisa) was developed for the detection and measurement of antibodies against infectious bronchitis virus (ibv). the purified and nonpurified virus used as antigen, the capture and detector antibodies, and the chicken hyperimmune sera were prepared and standardized for this purpose. a total of 156 sera from vaccinated and 100 from specific pathogen-free chickens with no recorded contact with the virus were tested. the respective serum titers obtained in the seru ... | 1999 | 10412553 |
| comparison of the immunofluorescent assay and reverse transcription-polymerase chain reaction to detect and type infectious bronchitis virus. | indirect fluorescent antibody (ifa) assay and reverse transcription-polymerase chain reaction (rt-pcr) are two current methods commonly used for the detection of infectious bronchitis virus (ibv) and its serotypes. the objectives of this study were to compare the two methods relative to detecting ibv in chicken embryos that were artificially inoculated with mass41, ark99, or mass41/ark99 in serial embryo passages and in tracheas and cecal tonsils collected from vaccinated commercial flocks with ... | 1999 | 10494432 |
| a reverse transcription-polymerase chain reaction assay for the detection of avian pneumovirus (colorado strain). | a reverse transcription-polymerase chain reaction assay was developed for the detection of avian pneumovirus (colorado strain) (apv-col). the specific primers were designed from the published sequence of the matrix protein gene of apv-col. the primers amplified a product of 631 nucleotides from apv-col. the assay identified only apv-col and did not react with newcastle disease virus and infectious bronchitis virus. | 1999 | 10494434 |
| serum levels of chicken mannan-binding lectin (mbl) during virus infections; indication that chicken mbl is an acute phase reactant. | mannan-binding lectin (mbl) is a serum collectin which is believed to be an opsonin of the innate immune defence against various microorganisms. mbl is a minor acute phase reactant in man. we investigated the concentration of serum mbl in chickens infected with infectious bronchitis virus (ibv) and infectious laryngotracheitis virus (iltv). the concentration of serum mbl increased about twofold (from approximately 6 to 12 microg/ml) due to these viral infections. the concentration peaked 3-7 day ... | 1999 | 10507370 |
| infectious bronchitis virus s2 gene sequence variability may affect s1 subunit specific antibody binding. | the s2 gene of several strains of infectious bronchitis virus (ibv) belonging to the arkansas, connecticut, and florida serotypes was sequenced. phylogenetic analysis of the s2 gene nucleotide and deduced amino acid sequence data resulted in groups of strains that were the same as groupings observed when s1 sequence data was used. thus, it appears that s2 subunits are conserved within a serotype but not between serotypes. although the sequence differences were small, we found that only a few ami ... | 1999 | 10541018 |
| csiro's 'natural' vaccines. | 1999 | 10561787 | |
| sequence analysis of the turkey coronavirus nucleocapsid protein gene and 3' untranslated region identifies the virus as a close relative of infectious bronchitis virus. | the 3' end of the turkey coronavirus (tcv) genome (1740 bases) including the nucleocapsid (n) gene and 3' untranslated region (utr) were sequenced and compared with published sequences of other avian and mammalian coronaviruses. the deduced sequence of the tcv n protein was determined to be 409 amino acids with a molecular mass of approximately 45 kda. the tcv n protein was identical in size and had greater than 90% amino acid identity with published n protein sequences of infectious bronchitis ... | 1999 | 10581391 |
| detection and strain differentiation of infectious bronchitis virus in tracheal tissues from experimentally infected chickens by reverse transcription-polymerase chain reaction. comparison with an immunohistochemical technique. | oligonucleotide pairs were constructed for priming the amplification of fragments of nucleocapsid (n) protein and spike glycoprotein (s) genes of avian infectious bronchitis virus (ibv) by reverse transcriptionpolymerase chain reaction (rt-pcr). one oligonucleotide pair amplified a common segment of the n-gene and could detect various strains of ibv in allantoic fluid from inoculated chicken embryos, and in tracheal tissue preparations from experimentally infected chickens. four pairs of oligonu ... | 1999 | 26905488 |
| pathogenicity of mycoplasma imitans in mixed infection with infectious bronchitis virus in chickens. | mycoplasma imitans (mim) has been isolated from ducks, geese and partridges, and is closely related to mycoplasma gallisepticum (mg). the pathogenicity of mim for chicks was investigated in single and mixed infections with infectious bronchitis virus (ibv) by giving ibv strain m41 at 1-day-old and mim 2 days later. single infections with ibv or mim were also performed. no clinical signs or gross lesions were seen in chicks infected with mim or uninfected control chicks, but they were seen in the ... | 1999 | 26915378 |
| longitudinal field studies of infectious bronchitis virus and avian pneumovirus in broilers using type-specific polymerase chain reactions. | in longitudinal studies, 13 flocks were swabbed twice each week for the life of the flock (up to 46 days). the swabs were analyzed by type-specific reverse transcriptase polymerase chain reactions. massachusetts type vaccinal infectious bronchitis virus (ibvs), applied at the hatchery, were usually maximal during the first week, as expected and, notably, remained detectable for 3 to 4 weeks, occasionally longer. ibv of the 793/b type (also known as 4/91 and cr88) was detected in 11/13 flocks (85 ... | 1999 | 27266431 |
| co-circulation of four types of infectious bronchitis virus (793/b, 624/i, b1648 and massachusetts). | eighteen isolates of infectious bronchitis virus (ibv) from italy and poland in 1997 to 1998 were comprehensively analysed by serum haemagglutination inhibition and virus neutralization tests, and by type-specific polymerase chain reactions and spike protein s1 gene sequencing. four types of ibv (793/b, 624/i, b1648 and massachusetts) were detected in italy, while the presence of 793/b was confirmed in poland. this showed that not only were four types of ibv co-existing within a single year, but ... | 1999 | 27266430 |
| detection of infectious bronchitis virus. | the detection methods for infectious bronchitis virus (ibv) are reviewed. advantages and disadvantages of available techniques of ibv detection by virus isolation, antigen or genome detection, and serology are discussed. factors of influence on the level of success in detection of ibv after a disease outbreak are discussed, as are the possibilities and dangers of strain classification by protectotyping, serotyping, epitope-typing and genotyping. | 2000 | 19184793 |
| turkey coronavirus is more closely related to avian infectious bronchitis virus than to mammalian coronaviruses: a review. | turkey coronavirus (tcov) is the cause of an acute highly contagious enteric disease of turkeys. in recent years, tcov has been increasingly recognized in north america as an important pathogen of young turkeys, resulting in economic loss due to impaired growth and poor feed conversion. while the epidemiology and pathogenesis of tcov have been extensively studied, tcov remains one of the least characterized of the known coronaviruses. avian and mammalian coronaviruses have been subdivided into d ... | 2000 | 19184806 |
| use of reverse transcriptase-polymerase chain reaction-restriction fragment length polymorphism to examine the interaction between infectious bronchitis virus strains massachusetts 41 and jmk in ovo. | the reverse transcriptase-polymerase chain reaction-restriction fragment length polymorphism (rtpcr-rflp) technique has been developed and used in the serotype diagnosis of infectious bronchitis virus (ibv) infection. in this report, we first demonstrate that the rt-pcr-rflp was sensitive in detecting both massachusetts 41 (mass 41) and jmk strains of ibv singly; the detection limit for both was approximately 0.15ng viral rna using gel electrophoresis. subsequently, the ability of the technique ... | 2000 | 19184836 |
| the q-base of asparaginyl-trna is dispensable for efficient -1 ribosomal frameshifting in eukaryotes. | the frameshift signal of the avian coronavirus infectious bronchitis virus (ibv) contains two cis-acting signals essential for efficient frameshifting, a heptameric slippery sequence (uuuaaac) and an rna pseudoknot structure located downstream. the frameshift takes place at the slippery sequence with the two ribosome-bound trnas slipping back simultaneously by one nucleotide from the zero phase (u uua aac) to the -1 phase (uuu aaa). asparaginyl-trna, which decodes the a-site codon aac, has the m ... | 2000 | 10623518 |
| identification of a novel cleavage activity of the first papain-like proteinase domain encoded by open reading frame 1a of the coronavirus avian infectious bronchitis virus and characterization of the cleavage products. | the coronavirus avian infectious bronchitis virus (ibv) employs polyprotein processing as a strategy to express its gene products. previously we identified the first cleavage event as proteolysis at the gly(673)-gly(674) dipeptide bond mediated by the first papain-like proteinase domain (plpd-1) to release an 87-kda mature protein. in this report, we demonstrate a novel cleavage activity of plpd-1. expression, deletion, and mutagenesis studies showed that the product encoded between nucleotides ... | 2000 | 10644337 |
| leader switching occurs during the rescue of defective rnas by heterologous strains of the coronavirus infectious bronchitis virus. | a defective rna (d-rna), cd-61, derived from the beaudette strain of the avian coronavirus infectious bronchitis virus (ibv), was rescued (replicated and packaged) using four heterologous strains of ibv as helper virus. sequence analysis of the genomic rna from the four heterologous ibv strains (m41, h120, hv10 and d207) identified nucleotide differences of up to 17% within the leader sequence and up to 4.3% within the whole of the adjacent 5' untranslated region (utr). analysis of the 5' ends o ... | 2000 | 10675417 |
| performance of an rt-nested pcr elisa for detection of newcastle disease virus. | a sensitive and specific rt-nested pcr coupled with an elisa detection system for detecting newcastle disease virus is described. two nested pairs of primer which were highly specific to all the three different pathotypes of ndv were designed from the consensus fusion gene sequence. no cross-reactions with other avian infectious agents such as infectious bronchitis virus, infectious bursal disease virus, influenza virus, and fowl pox virus were observed. based on agarose electrophoresis detectio ... | 2000 | 10713378 |
| cytotoxic t lymphocytes are critical in the control of infectious bronchitis virus in poultry. | various strains of infectious bronchitis virus (ibv) cause respiratory, kidney, enteric and reproductive illnesses in chickens, especially in newly hatched chicks. assays have been developed to identify gray strain ibv-specific cytotoxic t lymphocyte (ctl) responses using viral infected antigen presenting cells (apc) and using the semliki forest virus vector infected apc expressing individual viral polypeptides. it was shown that major histocompatibility complex restricted ctl are responsible fo ... | 2000 | 10717287 |
| avian infectious bronchitis virus: isolation of an apparently new variant in italy. | 2000 | 10718592 | |
| epithelial cell kinetics in the inflammatory process of chicken trachea infected with infectious bronchitis virus. | all stages of degeneration and regeneration in chicken tracheal epithelium were studied morphologically following an intratracheal inoculation of infectious bronchitis virus (ibv). viral antigen was detected in the cytoplasm of tracheal epithelium from 1 to 7 days post-inoculation (d.p.i.) with a peak on 3 d.p.i. at 1 d.p.i., almost all epithelial cells were involved in the degeneration. at this time, labelling index of bromodeoxyuridine (brdu) in the basal cells showed significantly high value ... | 2000 | 10720181 |
| adoptive transfer of infectious bronchitis virus primed alphabeta t cells bearing cd8 antigen protects chicks from acute infection. | infectious bronchitis virus (ibv) infection and associated illness may be dramatically modified by passive transfer of immune t lymphocytes. lymphocytes collected 10 days postinfection were transferred to naive chicks before challenge with virus. as determined by respiratory illness and viral load, transfer of syngeneic immune t lymphocytes protected chicks from challenge infection, whereas no protection was observed in the chicks receiving the mhc compatible lymphocytes from uninfected chicks. ... | 2000 | 10725210 |
| characterization of the stunting syndrome agent: relatedness to known viruses. | an enteric disease of young turkeys, referred to as stunting syndrome (ss), causes reduced growth and impaired feed efficiency. a recently isolated virus, stunting syndrome agent, (ssa) has been found to be the etiologic agent of ss. the objective of the present study was to determine relatedness of the ssa with other viral agents. serologic (viral neutralization and enzyme-linked immunosorbent assay [elisa]) assays and a reverse transcriptase-polymerase chain reaction (rt-pcr) were used. the an ... | 2000 | 10737643 |
| genetic relationships of infectious bronchitis virus isolates from mississippi broilers. | a 582-base pair segment located in the nucleocapsid protein terminal part of the s1 gene of 26 arkansas (ark)-type infectious bronchitis virus (ibv) isolates from mississippi broilers was amplified and sequenced. reverse transcription-polymerase chain reaction and cycle sequencing techniques were used to elucidate the genetic and deduced amino acid relationships among the isolates. analysis suggested that the nucleotide and amino acid sequences of the isolates were highly conserved, with greater ... | 2000 | 10737646 |
| a rapid-plate hemagglutination assay for the detection of infectious bronchitis virus. | a rapid-plate hemagglutination (ha) test to detect infectious bronchitis virus (ibv) in allantoic fluid of embryonated eggs was introduced into routine procedures for ibv identification. this system was tested in 468 diagnostic cases received by the poultry diagnostic and research center at the university of georgia. allantoic fluids from inoculated embryos were harvested and treated with commercially available neuraminidase enzyme. ibv in neuraminidase-treated allantoic fluid was identified by ... | 2000 | 10737649 |
| relationship between serotypes and genotypes based on the hypervariable region of the s1 gene of infectious bronchitis virus. | to group infectious bronchitis virus (ibv) isolates, a genetic grouping method based on hypervariable region 1 (hvr 1, nucleotides 168 to 197) was compared with that based on the whole s1 gene. both methods resulted in the same grouping data. so the grouping method based on hvr 1 could represent the grouping method based on the whole s1 gene. taiwan isolates could not be placed within the existing groups. in order to test the correlation between genotype and serotype, a one-way neutralization te ... | 2000 | 10752554 |
| infectious bronchitis virus e protein is targeted to the golgi complex and directs release of virus-like particles. | the coronavirus e protein is a poorly characterized small envelope protein present in low levels in virions. we are interested in the role of e in the intracellular targeting of infectious bronchitis virus (ibv) membrane proteins. we generated a cdna clone of ibv e and antibodies to the e protein to study its cell biological properties in the absence of virus infection. we show that ibv e is an integral membrane protein when expressed in cells from cdna. epitope-specific antibodies revealed that ... | 2000 | 10756047 |
| structure, stability and function of rna pseudoknots involved in stimulating ribosomal frameshifting. | programmed -1 ribosomal frameshifting has become the subject of increasing interest over the last several years, due in part to the ubiquitous nature of this translational recoding mechanism in pathogenic animal and plant viruses. all cis-acting frameshift signals encoded in mrnas are minimally composed of two functional elements: a heptanucleotide "slippery sequence" conforming to the general form x xxy yyz, followed by an rna structural element, usually an h-type rna pseudoknot, positioned an ... | 2000 | 10764589 |
| the amino and carboxyl domains of the infectious bronchitis virus nucleocapsid protein interact with 3' genomic rna. | previous studies indicated that the nucleocapsid (n) protein of infectious bronchitis virus (ibv) interacted with specific sequences in the 3' non-coding region of ibv rna. in order to identify domains in the n protein that bind to rna, the whole protein (409 amino acids) and six overlapping fragments were expressed as fusion polypeptides with six histidine-tags. using gel shift assays, the intact n protein and amino polypeptides, from residues 1 to 171 and residues 1 to 274, and carboxyl polype ... | 2000 | 10773316 |
| kinetics of lymphocytic subsets in chicken tracheal lesions infected with infectious bronchitis virus. | the kinetics of t-cells (cd3 positive (+), cd4+ and cd8+ cells) and b-cells (igg+, igm+ and iga+ cells) in chicken trachea were studied immunohistochemically and histopathologically following an intratracheal inoculation of infectious bronchitis virus (ibv). viral antigen was detected in the cytoplasm of tracheal epithelium from 16 hr to 6 days post-inoculation (p.i.) with a peak on 4 days p.i. a few igg+, igm+ and iga+ cells were detected in the submucosa from 8 hr p.i. thereafter igg+ and igm+ ... | 2000 | 10823726 |
| expression of reporter genes from the defective rna cd-61 of the coronavirus infectious bronchitis virus. | the defective rna (d-rna) cd-61, derived from the beaudette strain of the avian coronavirus infectious bronchitis virus (ibv), was used as an rna vector for the expression of two reporter genes, luciferase and chloramphenicol acetyltransferase (cat). d-rnas expressing the cat gene were demonstrated to be capable of producing cat protein in a helper-dependent expression system to about 1.6 microgram per 10(6) cells. the reporter genes were expressed from two different sites within the cd-61 seque ... | 2000 | 10859373 |
| localization of linear b-cell epitopes on infectious bronchitis virus nucleocapsid protein. | the nucleocapsid (n) protein of many viruses is highly conserved, immunogenic, and abundantly expressed during infection. these features make it a suitable candidate for diagnostic applications. the nucleocapsid protein of infectious bronchitis virus (ibv) was dissected into 12 fragments and expressed in escherichia coli. sera against australia t, china ch5, singapore p4, usa m41 and china t3 isolates were used to study the conservation and localization of the antigenic region on the ibv nucleoc ... | 2000 | 10865148 |
| further characterization of the coronavirus infectious bronchitis virus 3c-like proteinase and determination of a new cleavage site. | coronavirus infectious bronchitis virus (ibv) encodes a trypsin-like proteinase (3c-like proteinase) by orf 1a, which has been demonstrated to play a pivotal role in proteolytic processing of gene 1-encoded polyproteins. in our previous studies, the proteinase was identified as a 33-kda protein in ibv-infected cells, and its catalytic center was shown to consist of h(2820) and c(2922) residues. it is released from the 1a and 1a/1b polyproteins by autoprocessing at two q-s dipeptide bonds (q(2779 ... | 2000 | 10873746 |
| identification of avian infectious bronchitis virus by direct automated cycle sequencing of the s-1 gene. | direct automated cycle sequencing (dacs) of a reverse transcription-polymerase chain reaction (rt-pcr) product of the s-1 subunit of the spike peplomer gene was used to identify infectious bronchitis virus (ibv) serotypes. degenerate primers ck4 and ck2, utilized previously in our laboratory, were selected for dacs because they successfully amplify a wide range of serotypes represented by various reference strains and field isolates and the resulting polymerase chain reaction (pcr) product conta ... | 2000 | 10879913 |
| increased tracheal colonization in chickens without impairing pathogenic properties of avian pathogenic escherichia coli mt78 with a fimh deletion. | several studies suggest that the expression of f1 fimbriae could be involved in the virulence of escherichia coli for chickens. f1 fimbriae display multivalent properties such as adhesion to epithelia or interaction with the immune system that imply specific interactions between the adhesin fimh and different cell receptors. we constructed a delta fimh mutant of the avian pathogenic e. coli mt78 and evaluated its in vivo colonization and pathogenicity, as compared to that of the parent strain. t ... | 2000 | 10879915 |
| avian infectious bronchitis virus. | infectious bronchitis virus (ibv) is prevalent in all countries with an intensive poultry industry, with the incidence of infection approaching 100% in most locations. vaccination is only partially successful due to the continual emergence of antigenic variants. at many sites, multiple antigenic types are simultaneously present, requiring the application of multiple vaccines. although many countries share some common antigenic types, ibv strains within a geographic region are unique and distinct ... | 2000 | 10935276 |
| detection of antibody to turkey coronavirus by antibody-capture enzyme-linked immunosorbent assay utilizing infectious bronchitis virus antigen. | an antibody-capture enzyme-linked immunosorbent assay (elisa) for detection of antibody to turkey coronavirus (tcv) utilizing infectious bronchitis virus (ibv) antigen was developed. anti-tcv hyperimmune turkey serum and normal turkey serum were used as positive or negative control serum for optimization of the elisa system. goat anti-turkey immunoglobulin g (light plus heavy chains) conjugated with horseradish peroxidase was used as detector antibody. the performance of the elisa system was eva ... | 2000 | 11006996 |
| morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation. | the histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (massachusetts serotype). one-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (fv group); 2) nonfumigated and vaccinated birds (nfv group); 3) fumiga ... | 2000 | 11006997 |
| protective immunity to infectious bronchitis in broilers vaccinated against marek's disease either in ovo or at hatch and against infectious bronchitis at hatch. | two experiments were conducted using commercial broiler chickens to determine if marek's disease (md) vaccines hvt/sb-1 and hvt plus cvi-988 given either in ovo or at hatch adversely affected the efficacy of infectious bronchitis (ib) vaccines (ark and mass serotypes) given by eyedrop on the day of hatch. nonvaccinated negative controls and controls that received only ib vaccines were included in each study. birds were challenged with either infectious bronchitis virus (ibv) mass-41 or ibv ark-9 ... | 2000 | 11007000 |
| emergence of subtype strains of the arkansas serotype of infectious bronchitis virus in delmarva broiler chickens. | infectious bronchitis virus (ibv) field isolates of the arkansas (ark) serotype were identified by reverse transcription-polymerase chain reaction (rt-pcr) as the most common serotype isolated from 1993 to 1997. these isolates were recovered from broiler flocks with respiratory disease raised on the delmarva peninsula in spite of ark vaccination in the region. for the purposes of investigating this apparently paradoxical finding, five rt-pcr ark-positive field isolates recovered in 1995 and 1996 ... | 2000 | 11007004 |
| characterization of infectious bronchitis viruses isolated from outbreaks of disease in commercial flocks in brazil. | fifteen isolations of infectious bronchitis (ib) virus were made from a total of 126 brazilian poultry flocks of all ages that were examined. these flocks (14 chicken and 1 quail) were experiencing a variety of ib-like conditions including respiratory disease, digestive and kidney problems, and drops in egg production. one of the isolates was of the massachusetts serotype. the remainder were examined by means of cross-neutralization tests in tracheal organ cultures and were shown to belong to at ... | 2000 | 11007005 |
| redesign of primer and application of the reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism test to the de072 strain of infectious bronchitis virus. | diagnosis of the de072 strain of infectious bronchitis virus (ibv) by the reverse transcriptase-polymerase chain reaction (rt-pcr) and restriction fragment length polymorphism (rflp) serotype identification test was not possible because the primer used in the rt-pcr did not amplify the s1 gene of the de072 strain. the 3' end of the polymerase gene and the 5' end of the s2 gene of the de072 strain were sequenced and compared with the forward and reverse rt-pcr primers, respectively. a 2-bp mismat ... | 2000 | 11007014 |
| utilizing fowlpox virus recombinants to generate defective rnas of the coronavirus infectious bronchitis virus. | coronavirus defective rnas (d-rnas) have been used as rna vectors for the expression of heterologous genes and as vehicles for reverse genetics by modifying coronavirus genomes by targetted recombination. d-rnas based on the avian coronavirus infectious bronchitis virus (ibv) d-rna cd-61 have been rescued (replicated and packaged into virions) in a helper virus-dependent manner following electroporation of in vitro-generated t7 transcripts into ibv-infected cells. in order to increase the effici ... | 2000 | 11086116 |
| evidence of genetic diversity generated by recombination among avian coronavirus ibv. | previously, we demonstrated that the de072 strain of ibv is a recombinant which has an ibv strain d1466-like sequence in the s gene. herein, we analyzed the remaining 3.8 kb 3' end of the genome, which includes gene 3, gene 4, gene 5, gene 6, and the 3' non-coding region of the de072 and d1466 strains. those two viruses had high nucleotide similarity in gene 4. however, the other individual genes had a much different level of sequence similarity with the same gene of the other ibv strains. the g ... | 2000 | 11087096 |
| antigen quantification as in vitro alternative for potency testing of inactivated viral poultry vaccines. | routine batch control of licensed inactivated viral vaccines for poultry usually includes a potency assay as a measure of vaccine efficacy. potency assays often consist of vaccination-challenge experiments in the target species or in laboratory animals. instead of measuring the protection of vaccinated animals against virulent pathogens, the serological response after vaccination can be quantified for some vaccines. in vitro antigen quantification assays would be attractive alternatives for the ... | 2000 | 11087135 |
| a serological survey for avian infectious bronchitis virus and newcastle disease virus antibodies in backyard (free-range) village chickens in mexico. | the commercial flocks in yucatan, mexico are free of newcastle disease virus (ndv) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. a seroprevalence survey in 30 villages using haemagglutination inhibition (hi) tests for infectious bronchitis virus (ibv) and ndv antibodies was carried out from december 1997 to june 1998. the seroprevalences were 56.5% (95% ci 50-63%) for ibv and 2.2% (95% ci 0.5-3.8%) for ndv. all the villages had chickens th ... | 2000 | 11147278 |
| effect of liquid paraffin on antibody responses and local adverse reactions of bivalent oil adjuvanted vaccines containing newcastle disease virus and infectious bronchitis virus. | effects of liquid paraffin on antibody responses and local adverse reactions after intramuscular injection of oil adjuvanted vaccines containing newcastle disease (nd) and infectious bronchitis (ib) virus were investigated in chickens. each vaccine was prepared with a liquid paraffin such as carnation, crystol 52 and lytol. these vaccines induced sustained antibody responses against nd and ib. among local adverse reactions, lytol induced granulomatous reactions and abscesses, but carnation and c ... | 2000 | 11193350 |
| serological monitoring on layer farms with specific pathogen-free chickens. | to monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (spf) chickens were introduced into two layer farms and reared with laying hens for 12 months. spf chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. as a result, antibodies to eight or ten kinds of pathogens were detected in spf chickens on each farm. antibodies to infectious bronchitis virus (ibv), avian nephritis virus, mycoplasma galli ... | 2000 | 11193353 |
| molecular characterization of an infectious bronchitis virus strain isolated from an outbreak in vaccinated layers. | an infectious bronchitis virus (ibv) strain ct/7852/97 was isolated from a commercial layer flock experiencing decreased egg production and poor egg quality. reciprocal virus neutralization test demonstrated that the isolate was closely related to massachusetts, arkansas, and jmk. with the use of both reverse transcription-polymerase chain reaction-restriction fragment length polymorphism and multiplex polymerase chain reaction methods, results consistently showed that ct/7852/97 isolate was mas ... | 2000 | 11195625 |
| experimental escherichia coli respiratory infection in broilers. | this study determined optimal conditions for experimental reproduction of colibacillosis by aerosol administration of avian pathogenic escherichia coli to 2-to-4-wk-old broiler chickens. the basic model for reproducing disease was intranasal administration of approximately 10(4) mean embryo infectious dose of infectious bronchitis virus (ibv) followed by aerosol administration of an 02 or an 078 strain of e. coli in a horsfall unit (100 ml of a suspension of 10(9) colony-forming units/ml over 40 ... | 2000 | 11195629 |
| characterization of mexican strains of avian infectious bronchitis isolated during 1997. | ten infectious bronchitis virus (ibv) isolates were recovered from broiler chickens in the states of queretaro and guanajuato in mexico. the viruses were isolated from trachea, lung, kidney, and cecal tonsils of birds that showed respiratory signs in spite of vaccination with massachusetts (mass) and connecticut strains of ibv. each isolate was identified by an accession number from 1 to 10. six of the isolates were neutralized by mass monoclonal antibodies, whereas the other four were not. in a ... | 2000 | 11195651 |
| spike gene analysis of the de072 strain of infectious bronchitis virus: origin and evolution. | the entire s2 gene of the de072 strain of infectious bronchitis virus (ibv) was sequenced. the nucleotide and amino acid sequence was most similar to the d1466 strain and was 84.8% and 89.9% identity, respectively. the nucleotide and amino acid sequence similarity among the de072 strain and other ibv strains was less than 71.9% and 76.6%, respectively. phylogenetic analysis, based on both nucleotide and amino acid sequence, showed that ibv isolates were divided into two distinct groups. the de07 ... | 2001 | 11210943 |
| the missing link in coronavirus assembly. retention of the avian coronavirus infectious bronchitis virus envelope protein in the pre-golgi compartments and physical interaction between the envelope and membrane proteins. | one missing link in the coronavirus assembly is the physical interaction between two crucial structural proteins, the membrane (m) and envelope (e) proteins. in this study, we demonstrate that the coronavirus infectious bronchitis virus e can physically interact, via a putative peripheral domain, with m. deletion of this domain resulted in a drastic reduction in the incorporation of m into virus-like particles. immunofluorescent staining of cells coexpressing m and e supports that e interacts wi ... | 2001 | 11278557 |
| baculovirus expression of turkey coronavirus nucleocapsid protein. | the nucleocapsid (n) gene of turkey coronavirus (tcv) was amplified by reverse transcriptase-polymerase chain reaction, cloned, and expressed in the baculovirus expression system. a recombinant baculovirus containing the tcv n gene (rbtcv/n) was identified by polymerase chain reaction and expression of tcv n protein as determined by western immunoblot analysis. two tcv-specific proteins, 52 and 43 kda, were expressed by rbtcv/n; one of these proteins, p52, was comparable in size to native tcv n ... | 2001 | 11332474 |
| identification and analysis of the georgia 98 serotype, a new serotype of infectious bronchitis virus. | twenty-five field infectious bronchitis viruses (ibvs) similar to, but genetically distinct from, the de072 serotype were isolated from several states in the united states from 1990 through 1999 and were examined molecularly and antigenically. a 421-bp sequence in the hypervariable region of the s1 gene was examined, and phylogenetic analysis on that region indicated that these viruses are closely related but fall into unique groups. cross-virus neutralization testing and entire s1 sequence anal ... | 2001 | 11332478 |
| molecular epidemiology of infectious bronchitis virus isolates from china and southeast asia. | in order to trace the origin and evolution of avian infectious bronchitis virus (ibv) isolates in china and southeast asia, genomic sequencing was used for molecular characterization of 24 ibv isolates and two reference strains in comparison with the published sequences. the 5' region of the s1 genes, containing hypervariable regions i and ii, and 3' region of the nucleocapsid genes, containing cytotoxic t lymphocyte epitopes, were used to construct phylogenetic trees for analysis. the results s ... | 2001 | 11332484 |
| the exacerbating effect of infectious bronchitis virus infection on the infectious bursal disease virus-induced suppression of opsonization by escherichia coil antibody in chickens. | chickens infected with infectious bronchitis virus (ibv) and infectious bursal disease virus (ibdv) commonly develop secondary infection of the respiratory tract with escherichia coli, resulting in significant economic losses. to understand the host factors that may contribute to the e. coli infection, we investigated macrophage-mediated e. coli phagocytosis, intracellular bacterial killing, and development of opsonizing antibody in previously uninfected chickens and in those infected with ibv, ... | 2001 | 11332499 |
| maternal antibody to infectious bronchitis virus: its role in protection against infection and development of active immunity to vaccine. | chicks hatched with high levels of maternal antibody had excellent protection (>95%) against infectious bronchitis virus (ibv) challenge at 1 day of age, but not at 7 days (<30%). this protection significantly (p<0.05) correlated with levels of local respiratory antibody and not with serum antibody.a high percentage of both maternal antibody-positive (mab+) and maternal antibody-negative (mab-) chicks failed to produce ibv antibody when vaccinated at 1 day of age by the intraocular route. in add ... | 2001 | 11356248 |
| nucleocapsid protein gene sequence analysis reveals close genomic relationship between turkey coronavirus and avian infectious bronchitis virus. | antibodies to infectious bronchitis virus (ibv) cross-react with turkey coronavirus (tcv) in immunofluorescence assay (ifa) indicating that ibv and tcv may share an amino acid sequence similarity. to determine its extent, the gene encoding the nucleocapsid (n) protein of tcv was amplified by reverse transcription-pcr (rt-pcr) from rna purified from intestines of embryos of turkeys infected with various tcv isolates and from allantoic fluid of chicken embryos infected with ibv m41 strain, the obt ... | 2001 | 11394575 |
| induction of caspase-dependent apoptosis in cultured cells by the avian coronavirus infectious bronchitis virus. | avian coronavirus infectious bronchitis virus (ibv) is the causative agent of chicken infectious bronchitis, an acute, highly contagious viral respiratory disease. replication of ibv in vero cells causes extensive cytopathic effects (cpe), leading to destruction of the entire monolayer and the death of infected cells. in this study, we investigated the cell death processes during acute ibv infection and the underlying mechanisms. the results show that both necrosis and apoptosis may contribute t ... | 2001 | 11413307 |
| study of protection by recombinant fowl poxvirus expressing c-terminal nucleocapsid protein of infectious bronchitis virus against challenge. | a stable recombinant fowl poxvirus (rfpv) expressing the c-terminal region (119 amino acids) of the nucleocapsid (n) protein of an infectious bronchitis virus (ibv) strain ch3 was constructed by inserting the coding sequence within the thymidine kinase gene of fowl poxvirus (fpv) by homologous recombination. the n protein was expressed under control of the vaccinia virus promoter p7.5 in chicken embryo fibroblast cell cultures as seen in immunofluorescence assay and in rfpv-inoculated specific-p ... | 2001 | 11417813 |
| spike glycoprotein cleavage recognition site analysis of infectious bronchitis virus. | the spike glycoprotein of infectious bronchitis virus (ibv), a coronavirus, is translated as a precursor protein (so), then cleaved into two subunits (s1 and s2) by host cell serine proteases. in this study, we compared the cleavage recognition site of 55 ibv isolates to determine if the cleavage recognition site sequence, which consists of five basic amino acid residues, correlates with host cell range, serotype, geographic origin, and pathogenicity as it does in orthomyxoviruses and paramyxovi ... | 2001 | 11417816 |
| characterization of three infectious bronchitis virus isolates from china associated with proventriculus in vaccinated chickens. | outbreaks of an avian disease in infectious bronchitis-vaccinated chickens in china have led to the characterization of coronaviral isolates q1, j2, and t3, which were isolated from proventricular tissues of the affected young layer flocks. serologic analysis revealed that they could induce high titers of infectious bronchitis virus (ibv) antibodies in inoculated specific-pathogen-free (spf) chickens in indirect enzyme-linked immunosorbent assay but were not neutralized by antisera specific to t ... | 2001 | 11417821 |
| molecular characterization of infectious bronchitis virus isolates foreign to the united states and comparison with united states isolates. | eleven infectious bronchitis virus (ibv) isolates foreign to the united states were analyzed by using reverse transcriptase (rt)-polymerase chain reaction (pcr)/restriction fragment length polymorphism (rflp) and s1 glycoprotein gene sequencing. two of the isolates generated rflp patterns that resembled the mass 41 strain. seven novel rflp patterns were detected among the other nine foreign ibv isolates. five of the foreign isolates were further analyzed by s1 glycoprotein gene sequencing in our ... | 2001 | 11417834 |
| the autocatalytic release of a putative rna virus transcription factor from its polyprotein precursor involves two paralogous papain-like proteases that cleave the same peptide bond. | the largest replicative protein of coronaviruses is known as p195 in the avian infectious bronchitis virus (ibv) and p210 (p240) in the mouse hepatitis virus. it is autocatalytically released from the precursors pp1a and pp1ab by one zinc finger-containing papain-like protease (plpro) in ibv and by two paralogous plpros, pl1pro and pl2pro, in mouse hepatitis virus. the plpro-containing proteins have been recently implicated in the control of coronavirus subgenomic mrna synthesis (transcription). ... | 2001 | 11431476 |
| localization to the nucleolus is a common feature of coronavirus nucleoproteins, and the protein may disrupt host cell division. | the subcellular localization of transmissible gastroenteritis virus (tgev) and mouse hepatitis virus (mhv) (group i and group ii coronaviruses, respectively) nucleoproteins (n proteins) were examined by confocal microscopy. the proteins were shown to localize either to the cytoplasm alone or to the cytoplasm and a structure in the nucleus. this feature was confirmed to be the nucleolus by using specific antibodies to nucleolin, a major component of the nucleolus, and by confocal microscopy to im ... | 2001 | 11533198 |
| infectious bronchitis serology in broilers and broiler breeders: correlations between antibody titers and performance in vaccinated flocks. | in this study, a follow-up was made between 1993 and 1997 from broiler breeders at birth down to offspring broilers at processing, through vertically integrated registration of infectious bronchitis virus (ibv) antibody titers and performance data. all measurements were used two by two in a simple correlation study to calculate the degree to which they were linearly correlated. the antibody patterns in the broiler breeders indicated frequent field infections breaking through vaccinal immunity. s ... | 2001 | 11569734 |
| cases of swollen head syndrome in broiler chickens in greece. | from 50 commercial broiler flocks included in a study concerning respiratory disease, signs of swollen head syndrome (shs) were shown in eight. postmortem examination was performed in eight birds showing signs of shs from each flock. the trachea and head from each bird were collected for laboratory investigation. an enzyme-linked immunosorbent assay (elisa) was used for the detection of viral and avian mycoplasma antigens in the trachea, and bacteriologic examinations were performed from the inf ... | 2001 | 11569754 |
| origin and evolution of georgia 98 (ga98), a new serotype of avian infectious bronchitis virus. | we previously identified ga98, a new serotype of infectious bronchitis virus (ibv), which is closely related to the de072 serotype of ibv genetically, but not antigenically. herein, we analyzed the 421bp sequence of a hypervariable region (hvr) (position 114-534, counting from the atg start site) of the s1 subunit of ga98 ibvs to further examine the evolution of these viruses. these viruses were isolated between the years 1997 and 2000. phylogenetic analysis of the deduced amino acid sequence on ... | 2001 | 11597746 |
| further identification and characterization of novel intermediate and mature cleavage products released from the orf 1b region of the avian coronavirus infectious bronchitis virus 1a/1b polyprotein. | the coronavirus 3c-like proteinase is one of the viral proteinases responsible for processing of the 1a and 1a/1b polyproteins to multiple mature products. in cells infected with avian coronavirus infectious bronchitis virus (ibv), three proteins of 100, 39, and 35 kda, respectively, were previously identified as mature cleavage products released from the 1b region of the 1a/1b polyprotein by the 3c-like proteinase. in this report, we show the identification of two more cleavage products of 68 a ... | 2001 | 11601893 |
| reverse genetics system for the avian coronavirus infectious bronchitis virus. | major advances in the study of the molecular biology of rna viruses have resulted from the ability to generate and manipulate full-length genomic cdnas of the viral genomes with the subsequent synthesis of infectious rna for the generation of recombinant viruses. coronaviruses have the largest rna virus genomes and, together with genetic instability of some cdna sequences in escherichia coli, this has hampered the generation of a reverse-genetics system for this group of viruses. in this report, ... | 2001 | 11711626 |
| ribosomal pausing at a frameshifter rna pseudoknot is sensitive to reading phase but shows little correlation with frameshift efficiency. | here we investigated ribosomal pausing at sites of programmed -1 ribosomal frameshifting, using translational elongation and ribosome heelprint assays. the site of pausing at the frameshift signal of infectious bronchitis virus (ibv) was determined and was consistent with an rna pseudoknot-induced pause that placed the ribosomal p- and a-sites over the slippery sequence. similarly, pausing at the simian retrovirus 1 gag/pol signal, which contains a different kind of frameshifter pseudoknot, also ... | 2001 | 11713298 |
| completion of the porcine epidemic diarrhoea coronavirus (pedv) genome sequence. | the sequence of the replicase gene of porcine epidemic diarrhoea virus (pedv) has been determined. this completes the sequence of the entire genome of strain cv777, which was found to be 28,033 nucleotides (nt) in length (excluding the poly a-tail). a cloning strategy, which involves primers based on conserved regions in the predicted orf1 products from other coronaviruses whose genome sequence has been determined, was used to amplify the equivalent, but as yet unknown, sequence of pedv. primary ... | 2001 | 11724265 |
| growth and immunity of broiler chicks as affected by dietary arginine. | a dietary deficiency of arg may suppress chick immune system functions; however, research evaluating immune function responsiveness of commercial broilers fed dietary arg levels near nrc (1994) recommendations is sparse. therefore, three experiments were conducted to evaluate growth and immunity of broilers fed varying arg levels near nrc (1994) specifications. because arg and lys are similar in structure and are known to compete in intestinal absorption, dietary lys treatments [near nrc (1994) ... | 2001 | 11732668 |
| relationship between the level of dietary vitamin e and the immune response of broiler chickens. | the relationship between the dietary level of vitamin e (ve) and the immune response of broilers was studied in three experiments. immunity was assessed as antibody production to infectious bronchitis virus (ibv), srbc, and brucella abortus (ba) antigens, mitogenic response to phytohemagglutinin a (pha) and concanavalin a (con a), cutaneous basophil hypersensitivity (cbh) to pha, and lipopolysaccharide induction of acute-phase proteins (app) and heterophilia. a range of ve (0, 10, 17.5, 25, 37.5 ... | 2001 | 11732676 |
| further identification and characterization of products processed from the coronavirus avian infectious bronchitis virus (ibv) 1a polyprotein by the 3c-like proteinase. | 2001 | 11774483 | |
| enhancement of defective rna expression vectors as potential vaccine delivery systems for avian infectious bronchitis virus. | 2001 | 11774500 | |
| use of an infectious bronchitis virus d-rna as an rna vector. | 2001 | 11774515 | |
| use of defective rnas containing reporter genes to investigate targeted recombination for avian infectious bronchitis virus. | 2001 | 11774516 | |
| functional ibv minigenomes generated by recombinant fowl pox viruses for use in ibv-targeted recombination studies. | 2001 | 11774520 |