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P J Timoney

Publications and source records attributed to P J Timoney.

At least 37 records · Page 2Linked to original sources
PubMed1996

Genetic variation in open reading frame 2 of field isolates and laboratory strains of equine arteritis virus.

The open reading frame 2 (ORF2) of three laboratory strains, the live attenuated vaccine virus, and 18 field isolates of equine arteritis virus (EAV) from Europe and North America was sequenced. The ORF2 of EAV encodes the Gs protein that is abundantly expressed in infected cells but constitutes less than 2% of the virion protein mass. Variation of ORF2 among the isolates facilitated phylogenetic analysis that largely confirmed results of an earlier study based on sequence divergence of ORF5 of the same isolates of EAV, despite exposure of the proteins encoded by ORF2 (Gs) and ORF5 (GL) to potentially different selective pressures in vivo. The data indicate that the Gs protein is highly conserved between isolates, considerably more so than the GL protein, consistent with an important role of the Gs protein in virus replication.

Amino Acid Sequence↗
PubMed1996

Characterisation of proteins in the seminal plasma of stallions, geldings and supplemented with testosterone.

The major proteins in stallion seminal plasma were characterised by two-dimensional polyacrylamide gel electrophoresis, and compared with the patterns of proteins in normal geldings (castrated males) and geldings supplemented with testosterone. The major proteins or groups of proteins identified according to their approximate relative molecular weight in kilodaltons (kDa) and apparent isoelectric point (pl) were: 1) 60 kDa. pl 7; 2) 23 kDa, pl 4-5; 3) 25-30 kDa, pl 5.5-6; 4) 23 kDa, pl 7-8; and 5) 15-20 kDa, pl 6-7.5. Protein groups 1 and 2 were more prominent in the seminal plasma from the stallions and supplemented geldings than that from the unsupplemented geldings, while protein groups 3, 4 and 5 were more prominent in the seminal plasma from the unsupplemented geldings.

Animals↗
PubMed1995

Phylogenetic analysis of open reading frame 5 of field isolates of equine arteritis virus and identification of conserved and nonconserved regions in the GL envelope glycoprotein.

The variation and phylogenetic relationship of open reading frame 5 (ORF5) of 3 different laboratory strains of the original prototype Bucyrus strain of equine arteritis virus (EAV), the modified live virus vaccine (ARVAC, Fort Dodge Laboratories), and 18 field isolates of EAV from North America and Europe were determined by comparison of their gene sequences. The viruses differed from the published sequence by between 3 (99.6% homology) and 94 (87.8%) nucleotides and by between 3 (98.8%) and 24 (90.6%) amino acids. The field isolates differed from each other by between 2 (99.7%) and 110 (85.7%) nucleotides and by between 1 (99.6%) and 26 (89.8%) amino acids. Comparison of the nucleotide sequences of these viruses indicates that although they are very closely related, the ORF5 of each virus is distinct. The ORF5 of EAV encodes the GL envelope glycoprotein which expresses the neutralization determinants of the virus. Comparative analysis of the deduced amino acid sequence of the GL protein of the viruses identified three distinct variable regions (V1 [aa 61-121], V2 [141-178], and V3 [aa 202-222]), a putative signal sequence (S [aa 1-18]), and four conserved regions (C1 [aa 19-60], C2 [aa 122-140], C3 [aa 179-201], and C4 [aa 223-255]). Amino acid substitutions in the V1 region of the GL protein of EAV field isolates had significant effects on the predicted hydrophobicity and secondary structure of the protein, which is potentially important because this region contains a major neutralization site. Estimation of genetic distances and phylogenetic tree analysis of these viruses identified four distinct groups of EAV isolates, including two North American (NA1 and NA2) and two European (E1 and E2) groups. The sequence data obtained from individual European and North American isolates suggest movement of viruses between the two continents.

Amino Acid Sequence↗
PubMed1995

Clinical, virological and serological responses of donkeys to intranasal inoculation with the KY-84 strain of equine arteritis virus.

The clinical, virological and serological responses of seven female donkeys (Equus asinus) to inoculation with the KY-84 strain of equine arteritis virus (EAV), a strain that causes moderate to severe clinical signs in horses, was investigated. In the donkeys, the only clinical signs observed were fever (mainly 3-9 days after inoculation), mild depression in four animals, and a slight nasal or ocular discharge in three. All of the donkeys became infected with EAV as shown by recovery of the virus for periods of up to 14 days from the nasopharynx and buffy coat and, in three out of four donkeys sampled, from the cervix or vagina. Virus replication in the donkey appeared to mirror that previously described for the horse. The donkeys had "sero-converted" to EAV by the 10th day after inoculation. Additional studies are needed to obtain a better understanding of the pathogenesis of EAV in donkeys.

Administration, Intranasal↗
PubMed1995

Clinical features of the 1992 outbreak of equine viral arteritis in Spain.

During 1992, a widespread outbreak of Equine viral arteritis (EVA) occurred at a riding establishment near Barcelona, Spain. A total of 31 out of 186 horses on the premises displayed clinical signs, most frequently, fever, depression, mild ventral and limb oedema and a vesicular-erosive stomatitis, with hypersalivation, petechiations and small ulcerations. Affected horses developed illness of varying severity with only a few exhibiting a severe form of the disease and no mortality was recorded. Haematological and blood biochemical examination the most severely affected horses revealed a thrombocytopenia, slight leucocytosis with neutrophilia, lymphopenia and eosinopenia, an increase in plasma fibrinogen and a small rise in serum proteins and indirect bilirubin values. Diagnosis was confirmed by demonstration of seroconversion to equine arteritis virus in acute and convalescent phase sera. Attempted isolation of the virus from citrated blood samples proved unsuccessful.

Acute Disease↗
PubMed1994

Respiratory burst activity associated with phagocytosis of Ehrlichia risticii by mouse peritoneal macrophages.

Peritoneal macrophages from two strains of mice, BALB/c and C3H/HeN, were analysed by flow cytometry for a respiratory burst associated with the phagocytosis of Ehrlichia risticii. Resident murine peritoneal macrophages failed to respond with a respiratory burst after phagocytosing E risticii. In contrast, mice previously infected with E risticii yielded peritoneal macrophages that did generate a respiratory burst on phagocytosing ehrlichiae.

Animals↗
PubMed1994

Humoral antibody and lymphocyte blastogenesis responses in BALB/c, C3H/HeJ and AKR/N mice following Ehrlichia risticii infection.

Three strains of mice, two susceptible to Ehrlichia risticii induced disease (BALB/c and C3H/HeJ) and one resistant (AKR/N), were evaluated for the development of humoral and cell mediated immune responses following infection with E risticii. The production of serum antibody was determined by indirect fluorescent antibody testing of sera from mice of each strain challenged with one of three different dose levels of E risticii. Antibody was assayed on days 7, 9, 12, 15 and 20 after inoculation. Cell mediated immune responses were evaluated by measuring the blastogenesis response of spleen cells from E risticii infected mice 28 days after inoculation. All three strains of mice at the high challenge level responded with the production of antibody by day 9 after inoculation. Overall, the antibody response occurred earlier and was of greater magnitude in the susceptible BALB/c and C3H/HeJ strains. A marked blastogenesis response occurred in splenocytes from E risticii infected mice of all three strains upon re-exposure to ehrlichial antigen. The findings of this study indicate that susceptibility to E risticii induced disease was not the result of deficient or delayed humoral immune responses and that E risticii infection induced the development of strong cell mediated immunity.

Animals↗
PubMed1994

Resistance of castrated male horses to attempted establishment of the carrier state with equine arteritis virus.

Twelve geldings all became infected when inoculated intranasally with the KY-84 strain of equine arteritis virus (EAV), a strain previously shown to be capable of establishing the carrier state in the stallion. With the exception of one animal that showed no effects other than pyrexia, all of the geldings developed clinical signs characteristic of equine viral arteritis (EVA). The geldings were febrile for varying periods within the range of 2-10 days after inoculation. Viraemia occurred from day 2 onwards, for periods varying from 9 to at least 19 days. Nasal shedding of virus began 2-4 days after inoculation and persisted for periods ranging from 7-14 days. All geldings "seroconverted" to EAV by day 11, with serum neutralization titres ranging from 8 to 64. The titres ranged from 8 to 32 after 4 weeks. Low concentrations of EAV were detected in the kidney and blood of one gelding killed 30 days after inoculation and in the blood of another killed after 57 days. Virus was not isolated from any tissue or fluid sample collected from the remaining 10 geldings, all of which were killed between days 30 and 148. The findings confirm that persistent EAV infection is unlikely to occur in geldings and support the results of previous studies, which demonstrated that testosterone plays an essential role in the establishment and maintenance of the carrier state.

Animals↗
PubMed1994

Variation in susceptibility of ten mouse strains to infection with a strain of Ehrlichia risticii.

Eight inbred strains of mice (A/J, AKR/NCrlBR, BALB/cAnNHsd, C3H/HeJ, C3H/HeNHsd, C57BL/6J, C57BL/10SnJ and CBA/J) and two outbred strains (CF1 and ICR) were inoculated with a strain of Ehrlichia risticii and their relative susceptibility to disease was determined. The strains varied widely in susceptibility, some showing profound illness, with illness being barely detectable in others. Severity of illness was uniform within strains. This study confirmed that the A/J and BALB/cAnNHsd strains were very susceptible to illness, but the C3H/HeJ, CBA/J and the CF1 strains were slightly less susceptible. The C57BL/6J, C57BL/10SnJ, C3H/HeNHsd, AKR/NCrlBR and ICR strains were resistant.

Animals↗
PubMed1994

Correlation between ultrasonographic findings and serum testosterone concentration in prepubertal and peripubertal colts.

Correlation between serum testosterone concentration and morphometric findings from ultrasonography of the accessory sex glands in peripubertal colts was investigated during pubertal development. Nineteen colts of initial age ranging from 5 to 12 months were monitored over a 13-month period. Serum testosterone concentration was determined on a biweekly basis, and accessory sex gland development was ultrasonographically monitored once a month. Notwithstanding individual variation, there was significant correlation (r = 0.913; P < 0.01) between increasing serum testosterone concentration and the onset of developmental changes involving the accessory sex glands. As colts entered their 2-year-old year with relatively immature reproductive tracts, compared with mature stallions, there was still a significant seasonal effect on serum testosterone concentration and accessory sex gland measurements (P < 0.05). Ultrasonography was confirmed as a valuable noninvasive method of monitoring and assessing peripubertal accessory sex gland development in colts.

Animals↗
PubMed1993

Relationship between onset of puberty and establishment of persistent infection with equine arteritis virus in the experimentally infected colt.

The relationship between stage of reproductive tract maturity and susceptibility to the experimental establishment of persistent infection with equine arteritis virus (EAV) was investigated in 21 prepubertal and 15 peripubertal colts. Five of six prepubertal colts inoculated intranasally remained infected in the reproductive tract from post-challenge day 28 to 93 and two of six from post-challenge day 120 to 180. No virus was detected in five of these animals killed on post-challenge day 210. Each of two peripubertal colts remained infected in the reproductive tract at post-challenge day 60 and one of nine was found to be persistently infected with EAV 15 months after challenge. These findings confirm that the virus can replicate in the reproductive tract of a significant proportion of colts for a variable period of time after clinical recovery in the absence of circulating concentrations of testosterone equivalent to those found in sexually mature stallions. Long-term persistent infection with EAV does not appear to occur in colts exposed to the virus before the onset of peripubertal development. We suggest that colts should be vaccinated at approximately 6 months of age, before peripubertal development but after the disappearance of maternally acquired antibodies.

Age Factors↗
PubMed1993

Pathological changes associated with equine arteritis virus infection of the reproductive tract in prepubertal and peripubertal colts.

The nature and extent of changes associated with equine arteritis virus (EAV) infection of the reproductive tract was documented in 21 prepubertal and 15 peripubertal colts. This study was part of an investigation into the relationship between stage of reproductive tract maturity and susceptibility to the experimental establishment of persistent infection with EAV. After intranasal challenge with a field isolate of EAV, all colts developed clinical signs of equine viral arteritis (EVA) from which they recovered rapidly. Clinical signs during the acute phase consisted of fever, serous to mucopurulent ocular and nasal discharge, oedema of the limbs, scrotum or prepuce, scleral injection, conjunctivitis, icterus, cough, diarrhoea, stiff gait, lethargy, inappetence and depression. At necropsy, the most significant macroscopic lesions included excessive accumulation of fluid within the thoracic and abdominal cavities, lymph node enlargement and oedema of the reproductive tract. Colts killed 7 to 14 days after challenge had acute necrotizing vasculitis involving the testes, epididymides, vasa deferentia, ampullae, prostatic lobes, vesicular glands and bulbourethral glands. Vasculitis was characterized by striking fibrinoid necrosis of small muscular arteries with extravasation of erythrocytes and proteinaceous material into the media, adventitia and perivascular tissues. Colts examined on days 28-180 had lymphocytic and plasmacytic inflammatory cell infiltrates in the lamina propria and muscularis of the epididymides and accessory sex glands. The vascular lesions found during the acute phase of EAV infection contrasted with the multifocal lympho-plasmacytic infiltrates found within the parenchyma of the reproductive tract during the chronic phase. One peripubertal colt was found to be persistently infected with EAV 15 months after challenge. This colt had marked lympho-plasmacytic infiltrates in the ampullae at necropsy.

Aging↗
PubMed1993

Equine viral arteritis.

Equine viral arteritis is an infrequently encountered contagious viral disease of equids that has assumed increased veterinary medical and economic significance since the 1984 epidemic in Thoroughbreds in Kentucky. The most important consequences of this infection are abortion in the mare and establishment of the carrier state in the stallion. Equine arteritis virus becomes localized in the reproductive tract of a relatively high percentage of infected stallions which serve as very efficient transmitters of the infection through direct or indirect venereal contact with susceptible mares. The long-term persistently infected stallion appears to play a major epidemiologic role in the dissemination and perpetuation of the virus in horse populations throughout the world. Aspects of the pathogenesis, immunity, and epidemiology of equine arteritis virus are discussed in relation to current methods for the diagnosis, treatment, and control of this disease.

Animals↗
PubMed1993

In vitro killing of Ehrlichia risticii by activated and immune mouse peritoneal macrophages.

Normal resident murine peritoneal macrophages inoculated in vitro with Ehrlichia risticii readily phagocytized the organism but were unable to suppress ehrlichial replication as determined by indirect fluorescent-antibody staining of the inoculated cells. In contrast, macrophages from Corynebacterium parvum-inoculated and E. risticii-recovered mice rapidly eliminated the ehrlichiae. Macrophages from E. risticii-recovered mice were as effective as the C. parvum-activated cells in phagocytizing and eliminating the organism. Opsonization of E. risticii with homologous antiserum prior to inoculation of macrophage cultures resulted in enhancement of phagocytosis and greater suppression of E. risticii replication in all macrophage groups. These findings indicate that the pathogenesis of E. risticii infection centers on the ability of the organism to enter and replicate within the macrophage with avoidance of macrophage antimicrobial effects. An immune response results in macrophage activation with enhancement of the macrophage's ability to eliminate E. risticii. Opsonization of E. risticii with anti-E. risticii serum renders E. risticii more susceptible to macrophage destruction.

Animals↗
PubMed1992

Genomic variability among globally distributed isolates of equine arteritis virus.

Equine arteritis virus (EAV), a non-arthropod borne togavirus, has been shown to have a global distribution. To date, no major antigenic variation has been demonstrated between EAV isolates from different geographic origins. In this study, the genomic RNA of EAV isolates obtained from horses of different breeds in various countries around the world was oligonucleotide fingerprinted. Comparisons of these fingerprints were used to determine the extent of genomic variation among such isolates. Comparisons among isolates from North American horses revealed, for the most part, oligonucleotide homologies of less than 60%. Only 29 of the 98 comparisons revealed greater than 60% oligonucleotide homology. Nonetheless, several comparisons indicated a close epidemiologic relationship between isolates from horses of different breeds located in different states. Though all European isolates were of Standardbred origin and were from horses located in northern European countries, the majority had oligonucleotide homologies of less than 60%. Where oligonucleotide homology was apparent, it was, with one exception, greater than 70%. The two isolates from New Zealand had 93.2% oligonucleotide homology. This is indicative of an extremely close epidemiologic relationship. Comparisons between EAV isolates from around the world revealed oligonucleotide homologies between viruses from North America, Europe and New Zealand. In several instances, this homology was greater than 70% and in one case greater than 80%. No oligonucleotide homology was evident in comparisons involving the virus from South Africa. The high level of genomic conservation between certain EAV isolates of disparate geographic origins may reflect dissemination of the virus associated with the international movement of horses. The extent of genomic variation demonstrated between most of the EAV isolates used in this study confirms the need for further investigation of genomic heterogeneity among strains of this virus before techniques that rely upon nucleic acid hybridization can be effectively applied as diagnostic procedures.

Animals↗
PubMed1992

Venereal disease.

Equine venereal infections of concern in the United States include EHV-3, T. equigenitalis, P. aeruginosa, and K. pneumoniae. Stallions may also harbor EAV in the genital tract and transmit the virus to mares during coitus. With the exception of EHV-3, the stallion generally remains asymptomatic while transmitting infections to mares during breeding. Methods for diagnosis, treatment, and control of these infections are discussed.

Animals↗