Convergent Validity of Behavioural and Subjective Sensitivity in Relation to Autistic Traits.

Sensory issues are highly prevalent in autism and previous findings support a relationship between questionnaires of sensitivity and autistic symptoms and traits, whereas studies that examine this relationship through behavioural assessments of sensitivity are less consistent. The current study explores these differences and suggests that behavioural thresholds for sensitivity and subjective sensitivity are distinct constructs. One hundred and eighteen adults completed a visual and auditory detection task and questionnaires on sensory processing and autistic traits. Visual thresholds and subjective visual sensitivity were not correlated, but both were related to autistic traits. Auditory thresholds and subjective auditory sensitivity were also unrelated. Overall, sensitivity is highly associated with autistic traits, however, behavioural and questionnaire assessments lack convergent validity and therefore, likely assess distinct constructs.

Examining the relationship between measures of autistic traits and neural synchrony during movies in children with and without autism.

Children who have been diagnosed with autism spectrum disorder (ASD) often show a marked deficit in measures of social cognition. In autistic adults, measures of social cognition have been shown to relate to differences in brain synchronization (as measured by fMRI) when individuals are processing naturalistic stimuli, such as movies. However, whether children who differ in their degree of autistic traits, with or without a diagnosis of ASD, differ in their neural responses to movies has not yet been investigated. In the current study, neural synchrony, measured using fMRI, was examined in three groups of children aged 7 to 12, who differed with respect to scores on a measure of autistic traits associated with social impairment and whether or not they had been diagnosed with ASD. While watching the movie 'Despicable Me', those diagnosed with ASD had significantly less neural synchrony in areas that have been previously shown to be associated with social cognition (e.g. areas related to 'theory of mind'), and plot following (e.g. the lateral prefrontal cortex), than those who did not have an ASD diagnosis. In contrast, two groups who differed in their degree of autistic traits, but did not have a diagnosis of ASD, showed no significant differences in neural synchrony across the whole brain. These results shed some light on how autistic traits may contribute to an individual's conscious experience of the world, and how, for children with ASD, that experience may differ markedly from that of those without ASD.

Prevalence of serum neutralising antibody to equine rhinitis A virus (ERAV), equine rhinitis B virus 1 (ERBV1) and ERBV2.

The objective of this study was to determine the incidence of serum neutralising (SN) antibody to ERAV, ERBV1 and ERBV2 in a population of horses from birth to 22 years of age. The prevalences of ERAV, ERBV1 and ERBV2 SN antibodies in 381 sera obtained from 291 horses were 37%, 83% and 66%, respectively. ERAV, ERBV1 and ERBV2 maternal antibody was present in foals 12 h postsuckling but by 10-12 months, ERAV SN antibody was not detected in any of the horses, while ERBV1 and ERBV2 SN antibodies were common (83% and 100%, respectively). Sera were obtained from 44 Thoroughbred horses when they were newly introduced into a training centre when their average age was 23 months and a second sample was obtained approximately 7 months later. ERAV SN antibody was present in 8 (18%) when first bled and in 27 (61%) when tested 7 months later. Accordingly 19 of the 44 horses (43%) seroconverted to ERAV within 7 months of entering the training stable. Among all the horses the average ERAV SN antibody titre was relatively high (3796) and in contrast, ERBV1 and ERBV2 titres were relatively low (average 84 and 45, respectively) and often fell to below detectable levels over time and at a rate comparable to new seroconversions in the same group of horses.

Sequence conservation and antigenic variation of the structural proteins of equine rhinitis A virus.

The nucleotide and deduced amino acid sequences of the P1 region of the genomes of 10 independent equine rhinitis A virus (ERAV) isolates were determined and found to be very closely related. A panel of seven monoclonal antibodies to the prototype virus ERAV.393/76 that bound to nonneutralization epitopes conserved among all 10 isolates was raised. In serum neutralization assays, rabbit polyclonal sera and sera from naturally and experimentally infected horses reacted in a consistent and discriminating manner with the 10 isolates, which indicated the existence of variation in the neutralization epitopes of these viruses.

Evidence that Equine rhinitis A virus VP1 is a target of neutralizing antibodies and participates directly in receptor binding.

Equine rhinitis A virus (ERAV) is a respiratory pathogen of horses and is classified as an Aphthovirus, the only non-Foot-and-mouth disease virus (FMDV) member of this genus. In FMDV, virion protein 1 (VP1) is a major target of protective antibodies and is responsible for viral attachment to permissive cells via an RGD motif located in a distal surface loop. Although both viruses share considerable sequence identity, ERAV VP1 does not contain an RGD motif. To investigate antibody and receptor-binding properties of ERAV VP1, we have expressed full-length ERAV VP1 in Escherichia coli as a glutathione S-transferase (GST) fusion protein (GST-VP1). GST-VP1 reacted specifically with antibodies present in serum from a rabbit immunized with purified ERAV virions and also in convalescent-phase sera from horses experimentally infected with ERAV. An antiserum raised in rabbits to GST-VP1 reacted strongly with viral VP1 and effectively neutralized ERAV infection in vitro. Using a flow cytometry-based binding assay, we found that GST-VP1, but not other GST fusion proteins, bound to cell surface receptors. This binding was reduced in a dose-dependent manner by the addition of purified ERAV virions, demonstrating the specificity of this interaction. A separate cell-binding assay also implicated GST-VP1 in receptor binding. Importantly, anti-GST-VP1 antibodies inhibited the binding of ERAV virions to Vero cells, suggesting that these antibodies exert their neutralizing effect by blocking viral attachment. Thus ERAV VP1, like its counterpart in FMDV, appears to be both a target of protective antibodies and involved directly in receptor binding. This study reveals the potential of recombinant VP1 molecules to serve as vaccines and diagnostic reagents for the control of ERAV infections.

Single daily dose of methimazole compared to every 8 hours propylthiouracil in the treatment of hyperthyroidism.

This study to compare single-dose and multiple-dose antithyroid therapy was prompted by a perceived lack of compliance in our University Medical Clinics by those patients using multidose regimens. Twenty-two hyperthyroid patients were randomly assigned to two therapy groups. Twelve received methimazole (Tapazole) 30 mg once daily in the morning; 10 received propylthiouracil 100 mg every 8 hours. Patients were seen every 4 weeks for 3 months and assessed clinically, as well as having the appropriate thyroid tests done. Univariate analysis revealed no difference in the two groups at baseline. Posttreatment assessment revealed the once-a-day methimazole therapy to be just as effective as propylthiouracil in improving thyroid indices and clinical markers. Compliance with methimazole was 83.3% compared to 53.3% with propylthiouracil. In conclusion, once-a-day methimazole was just as effective as propylthiouracil every 8 hours in this population. Compliance was also improved with the once-a-day therapy.