Re-emergence of a genetic outlier strain of equine arteritis virus: Impact on phylogeny.

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids, which is notifiable in some countries including the Great Britain (GB) and to the OIE. Herein, we present the case of a persistently infected stallion and the phylogenetic tracing of the virus strain isolated. Discussing EAV occurrence and phylogenetic analysis we review features, which may aid to harmonise and enhance the classification of EAV.

Equivalent whole-body concentrations of 11-ketotestosterone in female and male coral goby Gobiodon erythrospilus, a bidirectional sex-changing fish.

The relationship between whole-body concentrations of 11-ketotestosterone (11-KT) and sexual function was examined in the coral goby Gobiodon erythrospilus, a bi-directional sex-changing fish. 11-KT occurred in both female and male G. erythrospilus, but levels were not always higher in males than in females within heterosexual pairs, and were not related to the stage of gonadal development of individual fish. These results suggest that comparable 11-KT levels in both sexes may allow serial adult sex change to take place in bi-directional sex-changing species, such as Gobiodon spp.

Dynamic differential regulation of innate immune transcripts during the infection of alveolar macrophages by the porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus, is the etiologic agent of an infectious disease of that name, characterized by respiratory disorders, abortion in pregnant sows and high mortality in piglets, resulting in significant economic losses in the pig industry worldwide. In order to identify whether genetic differences in PRRSV response may exist in pigs, alveolar macrophages were used to assess the progression of the type-I interferon (IFN) transcript response in porcine alveolar macrophages infected by PRRSV. Our results suggest that a dynamic differential regulation of the type-I IFN and chemokine transcripts may operate during the first hours of infection with and entry of the virus in alveolar macrophages, and provide a compelling mechanism for the establishment of PRRSV replication in susceptible cells.

Bryophyte dispersal by flying foxes: a novel discovery.

This research provides the first evidence of dispersal of bryophytes and associated microorganisms through ingestion by a highly mobile vertebrate vector, the spectacled flying fox (Pteropus conspicillatus). Bryophyte fragments were found in faeces collected at four P. conspicillatus' camps in the Wet Tropics bioregion, northeastern Australia. These fragments were viable when grown in culture; live invertebrates and other organisms were also present. Our study has significantly increased understanding of the role of flying foxes as dispersal vectors in tropical forests.

Detection of equine arteritis virus (EAV)-specific cytotoxic CD8+ T lymphocyte precursors from EAV-infected ponies.

Equine arteritis virus (EAV) causes a systemic infection in equids with variable outcome, ranging from subclinical infections to severe disease, and also has the capacity to induce abortion in pregnant mares and persistent infections in stallions. The serum virus-neutralizing antibody response that invariably develops in the infected animal lasts for many months or years and is believed to play an important role in virus clearance. However, very little is known about cellular immunity against EAV because of a lack of methods for evaluating these immune responses. In the present study, we describe methods for detecting cytotoxic T lymphocyte (CTL) precursors in the peripheral blood of EAV-convalescent ponies using a (51)Cr release cytolysis assay. Primary equine dermal cells, used as CTL targets, were shown to express MHC I but not MHC II and to retain (51)Cr efficiently and support EAV replication. Peripheral blood mononuclear cells (PBMC) collected from EAV-convalescent ponies that had been incubated with or without live EAV were used as effectors. EAV-induced PBMC cultures showed evidence of expansion and activation of lymphoblasts, with an increase in the CD8(+)/CD4(+) ratio in comparison with mock-induced PBMC. The cytotoxicity induced by EAV-stimulated PBMC was virus specific, showed genetic restriction, was mediated by CD8(+) T lymphocytes and could be detected for periods of 4 months to more than 1 year post-infection. These findings and methods will hopefully contribute to an understanding of virus-host interactions in horses, in particular the mechanisms of virus clearance occurring during EAV infection.

Use of medetomidine for capture and restraint of cassowaries (Casuarius casuaris).

OBJECTIVE: To examine the use of medetomidine for the sedation of captive and wild cassowaries (Casuarius casuarius). DESIGN: Clinical evaluation after administration of medetomidine by IM injection. PROCEDURE: Nine captive and two wild birds were chemically restrained, with the drug being administered by dart to 10 birds and hand injected to one. Doses of 0.26 to 0.31 mg/kg IM provided light sedation sufficient to allow approach and limited handling. Doses of 0.38 to 0.54 mg/kg IM provided heavy sedation adequate for full clinical examination. Body weights were estimated in six birds and measured in five birds and ranged from 40 to 66 kg. Sternal recumbency occurred in six birds, three in each dose range. In nine birds sedation was reversed with atipamezole at a dose of 15 to 80 mg/kg IM, which produced a return to alertness in 40 to 139 min. Forceful sneezing occurred during recovery in three birds. CONCLUSION: Medetomidine is a safe and reliable alternative to manual restraint in cassowaries.

Evaluation of a prototype sub-unit vaccine against equine arteritis virus comprising the entire ectodomain of the virus large envelope glycoprotein (G(L)): induction of virus-neutralizing antibody and assessment of protection in ponies.

An Escherichia coli-expressed recombinant protein (6hisG(L)ecto) comprising the entire ectodomain (aa 18-122) of equine arteritis virus (EAV) glycoprotein G(L), the immunodominant viral antigen, induced higher neutralizing antibody titres than other G(L)-derived polypeptides when compared in an immunization study in ponies. The potential of the recombinant G(L) ectodomain to act as a sub-unit vaccine against EAV was evaluated further in three groups of four ponies vaccinated with doses of 35, 70 or 140 microg of protein. All vaccinated animals developed a virus-neutralizing antibody (VNAb) response with peak titres 1-2 weeks after the administration of a booster on week 5 (VNAb titres of 1.8-3.1), 13 (VNAb titres of 1.4-2.9) or 53 (VNAb titres of 1.2-2.3). Vaccinated and unvaccinated control ponies were infected with EAV at different times post-vaccination to obtain information about the degree of protection relative to the levels of pre-challenge VNAb. Vaccination conferred varying levels of protection, as indicated by reduced or absent pyrexia, viraemia and virus excretion from the nasopharynx. The degree of protection correlated well with the levels of pre-challenge VNAb and, in particular, with levels of virus excretion. These results provide the first evidence that a sub-unit vaccine protects horses against EAV. The use of the sub-unit vaccine in combination with a differential diagnostic test based on other EAV antigens would enable serological discrimination between naturally infected and vaccinated equines.

Patterns of movement and seed dispersal of a tropical frugivore.

Movement is a fundamental feature of vertebrate behavior and can modify processes within populations and communities. Because tropical avian frugivores disperse seeds of many plant species, the temporal and spatial patterning of their movement will influence seed distribution within a habitat. To date, little is known about movement patterns of these birds. Here we consider the movement of an understory frugivore, Mionectes oleagineus. Movements of 16 non-breeding females were monitored using continuous radio-telemetry to provide a general description of movement patterns and to examine the fractal geometry of the spatial component of movement. Most movements were of short distance and duration, with the frequency distributions of both measures strongly skewed to the left. Over the range of measurement scales considered, the fractal dimension of M. oleagineus's movement increased with increasing measurement scale up to ca.100 m, whereafter it appeared to flatten out. We combined movement data with M. oleagineus gut-passage rates for seeds of six plant species to predict seed shadows. Estimated seed shadows were leptokurtic for four of the six plant species, with median dispersal distances for all species from 42 to 56 m. Dispersal distances were of the order of reported pollen dispersal distances, suggesting that even small seed dispersers like M. oleagineus can provide significant dispersal for plant genotypes. Gut-passage rate appears to determine the shape of the seed shadow, while movement determines dispersal scale.

When believing is seeing: the effect of scripts on eyewitness memory.

Two studies examined the conditions under which event schema or scripts produce gap-filling errors in eyewitness accounts of a robbery. In Study 1, scripts for the robbery of a convenience store were identified. Results revealed high agreement among the 120 participants concerning the sequence of actions for such a robbery. Based on the information obtained in Study 1, participants in Study 2 (N = 144) viewed one of two sequences of slides depicting a robbery of a convenience store by a lone robber. In one sequence, three central script actions were omitted and in the other, three peripheral script actions were omitted. In addition, rate of exposure was varied (2 vs. 8 sec) as was the length of the retention interval (5 min vs. 1 week). As predicted, there was a higher rate of false recognition for central as opposed to peripheral actions, and this tendency was exaggerated for the longer retention interval. The theoretical and practical implications of the findings are discussed.

Preliminary characterization of a non-haemagglutinating strain of rabbit haemorrhagic disease virus from the United Kingdom.

A variant strain of rabbit haemorrhagic disease virus, designated "Rainham', originally isolated from a small localized outbreak of the disease in southern England, has been further examined and compared with conventional reference strains. The virus originally failed to haemagglutinate in standard conditions at normal temperature and consistently lacked HA activity after two passages in experimental rabbits. It did haemagglutinate at 4 degrees C. It reacted with hyperimmune sera to normal isolates of RHDV from the UK and Italy, and showed no differential binding activity with a panel of monoclonal antibodies prepared from an Italian reference strain. The Rainham strain appears to be antigenically indistinguishable from other known isolates and this suggests that it may differ by only a few amino acid changes in its capsid protein sequence.

Development of a diagnostic approach to the identification of rabbit haemorrhagic disease.

Haemagglutination and ELISA tests, and negative contrast electron microscopy, have been used to identify rabbit haemorrhagic disease virus in naturally occurring cases of the disease and in experimentally infected rabbits in the United Kingdom. Haemagglutination tests alone are not satisfactory for the diagnosis because non-haemagglutinating isolates of the virus, otherwise indistinguishable from others, have been found in some outbreaks. Haemagglutination inhibition tests have shown that a proportion of both commercial laboratory and wild rabbits in the UK are seropositive to the virus although they have not been associated with clinical disease. This observation, made previously in other parts of Europe, may indicate the longstanding circulation of a related but non-pathogenic strain of virus. Naturally occurring antibody appears to afford a high degree of protection against experimental challenge with virulent virus.

European brown hare syndrome in the U.K.; a calicivirus related to but distinct from that of viral haemorrhagic disease in rabbits.

The virus recovered from cases of European brown hare syndrome in the U.K. contains one major capsid protein of approximately 60 k molecular weight and morphologically resembles known caliciviruses. It has been compared with a European isolate of rabbit haemorrhagic disease calicivirus and, although it shows some antigenic similarity, it is not identical. In transmission and protection studies the virus from U.K. hares failed to produce disease in rabbits and did not effectively protect against subsequent challenge with the rabbit calicivirus.

Response of cattle persistently infected with bovine virus diarrhoea virus to bovine leukosis virus.

Six cattle persistently infected with bovine virus diarrhoea virus (BVDV) and seronegative, and two control, virus negative seropositive cattle were inoculated with lymphocytes infected with bovine leukosis virus (BLV). The two controls produced a normal immune response to BLV, developing antibodies at four and five weeks after inoculation. Two of the six cattle persistently infected with BVDV developed a strong antibody response by six weeks after inoculation with BLV. Four developed a depressed response to BLV, characterised in three by a 'hooking' reaction in the immunodiffusion test which persisted in successive bleedings but was interspersed occasionally by a weak positive reaction. In one of these animals, a series of 'hooking' reactions was followed by a number of negative results. The fourth animal remained serologically negative until 16 weeks after inoculation when a 'hooking' reaction was observed followed by a series of negative results. BLV was isolated from all the cattle persistently infected with BVDV at 42 or 58 weeks after inoculation regardless of whether the serum samples gave negative, 'hooking', weak positive or positive reactions in the immunodiffusion test. BLV was consistently isolated from the nasal secretions of a steer which was BVDV negative but seropositive. The possibility of decreased immune responsiveness to BLV in animals persistently infected with BVDV should be considered when formulating regulations governing the testing of animals for freedom from BLV.

The isolation of a virus resembling a polyomavirus from normal calves.

Viruses with characteristics of polyomaviruses were isolated from the kidneys of 18 out of 64 clinically normal calves 1-2 weeks old. All the viruses were serologically related.

Low-birth-weight infants in the Cape Peninsula. A follow-up study at the age of 3 years.

A sample of coloured children from the Cape Town City Council area who had been of low birth weight, although a weight appropriate for gestational age, was examined at the age of approximately 3 years. The children were compared with a control group of similar social background who had been of normal birth weight. Growth parameters were compared with the National Center for Health Statistics centiles. The low-birth-weight infants had compensated well. Although they were lighter, shorter in stature and had lower intelligence quotient scores than their normal-birth-weight contemporaries, when corrected for prematurity the growth parameters and IQ did not differ significantly from those of the controls. Six per cent of the preterm infants had major and 15% minor handicaps. Infants with very low birth weights (less than 1500 g) had no more handicaps than those with low birth weights. Iron deficiency was detected in 18% of the children overall but all those who were anaemic were from the low-birth-weight groups. Between 1 and 3 years of age the low-birth-weight infants had more illnesses but no more hospital admissions than the controls.

An evaluation of five serological tests for the detection of antibody to bovine herpesvirus 1 in vaccinated and experimentally infected cattle.

More than 300 bovine sera from a previously reported vaccination and challenge trial were tested for antibodies to bovine herpesvirus 1 (BHV1) by five serological assays: enzyme-linked immunosorbent assay (ELISA) for IgM and IgG, passive haemagglutination (PHA), and two methods of virus neutralisation (VN). In a statistical comparison of ELISA (IgG), PHA and VN results, the assays showed highly significant correlations (P less than 0.01). The sensitivities of ELISA and 24-hour neutralisation tests were similar, in contrast to passive haemagglutination and one hour neutralisation which failed to detect BHV1 antibodies in some low titre sera.

Health care of preterm infants in the first year of life.

The home environment of preterm infants and their use of health services after discharge from hospital were investigated. Of the mothers of preterm infants studied 49% were not educated beyond primary school level, 38% were unmarried and 20% of these families had marked social problems, and 56% lived in grossly overcrowded conditions. Only the extent of unmarried motherhood and marked social problems were greater in preterm infants than in a control group of term infants. Attendance at primary care services for illness was no different for the preterm and term groups, although hospital admissions were most frequent in the preterm infants. Three preterm infants died in the first year. Only 65% of preterm infants and 55% of controls had completed weight charts on their preschool record card at 12 months of age. Three preterm and 2 control infants had not been fully immunized. In spite of poor social circumstances, the use of health services by the mothers of preterm infants was most encouraging.