SEARCH · PubMed Health

Results for “MOUTH DISEASES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources

PubMed1995

Optimization of an in situ hybridization technique for the detection of foot-and-mouth disease virus in bovine tissues using the digoxigenin system.

An in situ hybridization technique has been optimised for use on paraffin-embedded sections of tissues collected from cattle infected experimentally with foot-and-mouth disease virus type O1BFS. Tissue was collected 5 days after infection by direct contact. In situ hybridization was carried out using an RNA probe corresponding to a region of the 3D gene which codes for the RNA polymerase, and labelled with digoxigenin. Consistent, reproducible signal was detected within the epithelial layers of the palatine tonsil, soft palate and pharyngeal tissue studied. This is the first time that a digoxigenin-based system has been used successfully for FMD virus RNA detection with bovine tissue samples.

Animals↗

PubMed1985

The use of a logistic model for the quantitative interpretation of indirect sandwich enzyme labelled immunosorbent assays (ELISA) for antibodies and antigens in foot and mouth disease.

A three parameter logistic model is described for the analysis of profiles of optical density vs log dose for indirect sandwich ELISA tests in foot and mouth disease. The model describes the observed phenomenon of saturability with increasing dose, and its parameters can be interpreted in terms of molecular binding events. A computer program to fit the model is described. An approximate statistical test is developed which can be used to test for departures from equivalence for replicate profiles. It is found that correlation of the optical density values to a standard reference reaction considerably improves reproducibility.

Animals↗

PubMed1985

Homologous interference by a foot-and-mouth disease virus strain attenuated for cattle.

An attenuated strain of foot-and-mouth disease virus (FMDV) of the A24 Cruzeiro subtype grew less well than wild-type virus in primary bovine fetal kidney (PBK) cells resulting in a 4-log lowered efficiency of plaque formation. Both wild-type and attenuated virus grew equally well in baby hamster kidney (BHK) cells and in suckling mice. Using PBK cells, virus-specific RNA of the wild-type accumulated up to 6 hours after infection. In contrast, PBK cells infected with the attenuated strain made less than 20 per cent of the RNA synthesized by wild-type virus. Infection of the cell with wild-type virus followed by superinfection with attenuated virus led to almost complete inhibition of viral RNA synthesis, an effect which is dependent on the concentration of input attenuated virus. Three subsequent undiluted successive passages of the attenuated virus resulted in a preparation which no longer interfered with wild-type RNA synthesis and which induced more of its own viral RNA synthesis in PBK cells. The basis of this interference was considered. Interference occurred intracellularly and was directed only against viruses within the genus FMDV. A role for interferon was ruled out. Attempts to demonstrate the physical presence of defective interfering (DI) particles of FMDV in the attenuated strain failed; but, cyclic patterns of infectivity were produced during successive undiluted passages.

Animals↗

PubMed1978

Ribonuclease activities associated with purified foot and mouth disease virus.

Ribonuclease activities internally and externally associated with purified foot-and mouth disease virus were detected. The outer activity was easily removed by cesium chloride or by detergent (Sarkosyl). The inner activity is not removable by any procedure used and could be the enzyme responsible for the heterogeneity normally observed in the extracted FMDV-RNA. It is not known at present if both activities are related to the same or to different enzymes.

Aphthovirus↗

PubMed1983

Isolation of capsid proteins of foot-and-mouth disease virus by chromatofocusing.

A method for the isolation of foot-and-mouth disease virus (FMDV) capsid proteins was developed. The FMDV capsid proteins VP1, VP2, VP3 and VP0 were isolated from sucrose gradient purified virus by chromatofocusing in a pH 7.4-4.0 gradient on Polybuffer exchanger PBE 94. Under the conditions used the proteins eluted in the sequence VP1, VP2, VP0 (when present) and VP3. Capsid protein VP4 did not elute and could not be isolated by this method. Protein concentration in the eluate was monitored by the use of a radiolabelled marker and recoveries of approximately 50% of the input marker could be achieved when using up to 15 mg of virus and a 30-ml column. The high capacity and relative simplicity of chromatofocusing make it a useful alternative to other methods of purifying proteins.

Animals↗

PubMed1988

Further characterization of an RNA defective mutant of the foot-and-mouth disease virus.

In this paper a further characterization of a foot-and-mouth disease virus (FMDV) temperature-sensitive mutant, ts 6, is described. This mutant presents a defective RNA synthesis at non-permissive temperature (NPT) by comparison to the wt capacity. However, a low level of viral RNA synthesis (below 10%) was sufficient to achieve an almost normal protein synthesis including a normal pattern of protein cleavage. In addition, morphogenetic precursor particles, 14S and 75S, are formed, indicating that the structural proteins VP0, VP1 and VP3 provide the necessary signal for self-assembly, and that the RNA is not necessary for such assemblage. Finally, although an almost normal synthesis of viral proteins and morphogenetic precursors (14S and 75S) occurs, the induction of cellular protein shut-off was not evident, indicating that this viral effect appears late in the viral cycle once complete viral replication has occurred.

Animals↗

PubMed1983

A serological and biochemical study of new field isolates of foot-and-mouth disease virus type A in Peru, 1975 to 1981.

Three foot-and-mouth disease virus type A isolates recovered from field outbreaks in the Department of San Martin, Peru, during the period 1975 to 1981 were compared with each other, and the South American vaccine strains A24 and A27, by complement fixation (CF), virus neutralization (VN) and polyacrylamide gel electrophoresis (PAGE). Complement fixation and VN tests gave comparable results distinguishing the field isolates from each other and from the vaccine strains. Analysis of the structural polypeptides by PAGE also showed clear differences between all the viruses examined. Samples from tissue culture passaged and mouse adapted strains of one of the field isolates gave identical patterns in PAGE, but differences were observed in the polypeptide pattern of the A24/BRA/55 strain and the Peru vaccine strain, which were serologically indistinguishable. Results illustrate a continued antigenic variation in an endemic area where vaccination has been used; however, asymmetric serological reactions between the A24 vaccine strain and the most recent field isolate indicated that a vaccine incorporating A24 should still give adequate protection.

Animals↗

PubMed1998

Exposure of in vitro-produced bovine embryos to foot-and-mouth disease virus.

The aim of this study was to investigate whether foot and mouth disease virus (FMDV) interacts with in vitro produced (IVP) bovine embryos. One milliliter of a suspension of FMDV (2 x 10(7) TCID50/mL) was added to several batches of these embryos 7 d after in vitro fertilization, by which time they had either developed to the morula/blastocyst stage (n = 256) or degenerated (n = 260). Six experiments were performed in which developed or degenerated batches of embryos were incubated with FMDV for periods of 1 h (3), 2 h (2) or 4h (1). After this, the embryos were washed 10 times according to the International Embryo Transfer Society (IETS), then pooled and ground up to form a suspension, and assayed on cell cultures for FMDV. The cell cultures were observed daily for cytopathic effects for 3 d post exposure. In addition to the cell culture method, the polymerase chain reaction (PCR) technique was used to assay for the presence of the virus in the washing fluids. Assays for FMDV were also conducted on the first and second wash and on the pooled sample constituting the eight, ninth and tenth wash. With the exception of the second wash from a batch of embryos exposed to FMDV for 2 h, all samples of the first and second wash produced FMDV cytopathic effects, but none occurred with the pooled samples of the 8th, 9th and 10th wash. FMDV was also isolated from all but 1 of the batches of embryos after 1 h of incubation, from 1 of 4 batches after 2 h of incubation and from all batches after 4 h incubation. By contrast, the presence of virus could not be demonstrated by PCR based on the technique used here. These results show that 7 d old IVP bovine embryos can retain FMDV after washing, unlike in vivo-derived embryos, which do not appear to carry risks of FMDV transmission when washed according to IETS recommendations. Stricter controls are, therefore, necessary when using IVP embryos from cattle in a non-FMD-free zone in domestic or international trade.

Animals↗

PubMed1981

Molecular cloning of foot and mouth disease virus genome and nucleotide sequences in the structural protein genes.

Foot and mouth disease virus (FMDV), of the family Picornaviridae, consists of a single-stranded RNA (approximately 8,000 nucleotides), the translation of which is initiated on the 3' side of a 150-nucleotide poly(C) tract and yields a single polyprotein which is processed by host cell proteases into four primary products (Fig. 1). One or more virus-specified proteases further cleave these into the final products, the capsid proteins (VP1-4) being derived from the precursor p88 (for review see ref. 5). There are seven serotypes of the virus and as it has been shown that the immunizing activity of FMDV particles is associated primarily with VP1 (refs 6, 7), it seems likely that antigenic variation in FMDV is a result of changes in the structure of this protein. To further our understanding of this variation and as a first step in the possible development of FMDV vaccines from genetically manipulated microorganisms, we report here the construction and analysis of recombinant plasmids containing cDNA copies of the RNA. Comparison of the deduced amino acid sequence with the known polypeptide sequences shows that the NH2-termini of VP2 and VP3 are conserved between the A and O serotypes whereas that of VP1 (the immunizing antigen) varies by as much as 42% between serotypes.

Amino Acid Sequence↗

PubMed1984

Biologically active protease of foot and mouth disease virus is expressed from cloned viral cDNA in Escherichia coli.

Foot and mouth disease virus O1K cDNA had been cloned in Escherichia coli. Here we report on in vitro recombination of cDNA fragments according to the cDNA restriction map and on expression of viral proteins in E. coli. Use was made of the expression vector pPLVP1 , which is known to express the virus capsid protein VP1. Recombined cDNAs of various sizes were inserted downstream from the VP1 gene. The constructed plasmids differ from each other in the number of virus genes coding for nonstructural proteins. The effects caused by their expression in E. coli are compared. It is shown that the virus protease is expressed in E. coli as an active enzyme that recognizes the simultaneously produced virus-specific polyprotein as substrate. The virus protease gene was mapped 5'-adjacent to the virus replicase gene.

Aphthovirus↗

PubMed1984

Nucleotide sequence and genome organization of foot-and-mouth disease virus.

A continuous 7802 nucleotide sequence spanning the 94% of foot and mouth disease virus RNA between the 5'-proximal poly(C) tract and the 3'-terminal poly(A) was obtained from cloned cDNA, and the total size of the RNA genome was corrected to 8450 nucleotides. A long open reading frame was identified within this sequence starting about 1300 bases from the 5' end of the RNA genome and extending to a termination codon 92 bases from its polyadenylated 3' end. The protein sequence of 2332 amino acids deduced from this coding sequence was correlated with the 260 K FMDV polyprotein. Its processing sites and twelve mature viral proteins were inferred from protein data, available for some proteins, a predicted cleavage specificity of an FMDV encoded protease for Glu/Gly(Thr, Ser) linkages, and homologies to related proteins from poliovirus. In addition, a short unlinked reading frame of 92 codons has been identified by sequence homology to the polyprotein initiation signal and by in vitro translation studies.

Amino Acid Sequence↗

PubMed1984

The complete nucleotide sequence of the RNA coding for the primary translation product of foot and mouth disease virus.

The complete nucleotide sequence of the coding region of foot and mouth disease virus RNA (strain A1061) is presented. The sequence extends from the primary initiation site, approximately 1200 nucleotide from the 5' end of the genome, in an open translational reading frame of 6,999 nucleotides to a termination codon 93 nucleotides from the 3' terminal poly (A). Available amino acid sequence data correlates with that predicted from the nucleotide sequence. The amino acid sequence around cleavage sites in the polyprotein shows no consistency, although a number of the virus-coded protease cleavage sites are between glutamate and glycine residues.

Amino Acid Sequence↗

PubMed1987

Potential secondary and tertiary structure in the genomic RNA of foot and mouth disease virus.

The nucleotide sequence of the 5' untranslated region of foot and mouth disease virus (FMDV), serotype A10 has been determined. This completes the first total genomic sequence for any one serotype of FMDV. Analysis of the sequence to the 3' side of the poly (C) tract reveals the presence of a 24 nucleotide repeated motif which has homologies with a sequence located upstream of the transcriptional initiation site from several mammalian fibrinogen genes. The function of this element in FMDV is unclear. However, computer analysis of this region predicts the presence of a high degree of secondary and tertiary structure in which these repeats form an important part. The implications of these predictions are discussed.

Aphthovirus↗

PubMed1980

Serological and immunological relations between the 146S and 12S particles of foot-and-mouth disease virus.

Intact 146S particles of the seven serotypes of foot-and-mouth disease virus (FMDV) produce type-specific precipitating, complement-fixing and neutralizing antibodies in cattle and guinea-pigs. However, the 12S structural subunit, produced from the virus particle by mild acid treatment (pH 6) or by heating at 56 degrees C, although stimulating the production of precipitating and complement-fixing antibodies, produces only low levels of neutralizing antibody. Nevertheless, 12S antibody in guinea-pigs primed with a vaccine prepared from 146S particles. Moreover, heterotypic 12S and 146S particles also boosted the neutralizing antibody response to the first virus. These results point to an antigenic similarity between the 146S particles of each type and to a close antigenic relationship between the 146S and 12S particles.

Animals↗

PubMed1981

A sensitive method for the detection and isolation of recombinants of foot-and-mouth disease virus.

Recombination between temperature-sensitive (ts) mutants of foot-and-mouth disease (FMD) virus was examined, using an infectious centre technique that was more sensitive (approx. 30-fold) than the conventional virus yield test. The test involved a brief incubation of the mixedly infected cells at the permissive temperature to allow recombination to occur followed by assay at the restrictive temperature to select for those cells in which recombination had occurred. With crosses involving widely separated mutations, as many as 28% of the infected cells produced presumptive recombinant plaques. Since each plaque was the result of an independent event, large numbers of different presumptive recombinants could be isolated for further study. Analysis of presumptive recombinant plaques from a variety of crosses showed that, in general, the virus produced had the properties expected of recombinants. An approximate correlation was found between genetic distance, as determined in the yield recombination test, and the percentage of recombinant infectious centres observed. The phenomenon was very sensitive to the balance between the input multiplicities of the two parent viruses and occurred very early in virus replication. The test has considerable potential for the study of genetic interactions in FMD virus, but it would be surprising if this potential was limited to picornaviruses.

Animals↗

PubMed1965

Detection of Minimal Quantities of Foot-and-Mouth Disease Virus with Bovine Kidney Tissue Cultures.

Minute quantities of foot-and-mouth disease virus (FMDV) were suspended in 500-, 1,000- and 2,000-ml volumes of virus growth medium and inoculated into primary bovine kidney cell cultures grown as monolayers in 5-liter Povitsky bottles. After 48 hr of incubation, the low concentrations of FMDV, containing from 10 to 10 plaque-forming units (PFU) per milliliter of inoculum, multiplied to approximately 10 PFU per milliliter of fluid. The presence of extracellular virus after multiplication was verified by assaying the fluid in 4-oz prescription-bottle cultures. Minimal quantities of FMDV were able to infect the cells and replicate despite the large volume of the suspending fluid. This technique may be applicable for the detection of trace amounts of FMDV in clinical samples and vaccines. Skin samples of unknown infectivity in limited tests gave identical positive or negative results in both steers and Povitsky cultures, but were consistently negative when tested in suckling mice and in prescription-bottle tissue cultures.

Journal Article↗

PubMed1971

Mouse Resistance Against Foot-and-Mouth Disease Virus Induced by Injections of Pyran.

Mouse resistance to foot-and-mouth disease virus (FMDV) was induced by intraperitoneal injections of pyran copolymer. A biphasic pattern of protection occurred with greatest resistance 4 and 48 hr after injection of this polyanion. Viremia was not detectable in pretreated mice challenge-exposed with FMDV. Incubation of virus with pyran did not alter viral infectivity in mice or tissue culture. Serum interferon was demonstrated 1 and 2 days after pyran administration.

Journal Article↗

PubMed1973

Neutralizing antibody response in bovine serum and nasal and salivary secretions after immunization with live or inactivated food-and-mouth disease virus.

Calves develop nasal and salivary neutralizing antibodies against foot-and-mouth disease virus after nasal inoculation with live virus. Nasal and salivary antibody was not detected after exposure to inactive virus. Serum antibodies were induced by live and inactive virus given subcutaneously. Passively acquired antibodies were detected as long as 7 months after birth.

Animals↗