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1.  Prevalence of congenital hereditary sensorineural deafness in Australian Cattle Dogs and associations with coat characteristics and sex 
Background
Congenital hereditary sensorineural deafness (CHSD) occurs in many dog breeds, including Australian Cattle Dogs. In some breeds, CHSD is associated with a lack of cochlear melanocytes in the stria vascularis, certain coat characteristics, and potentially, abnormalities in neuroepithelial pigment production. This study investigates phenotypic markers for CHSD in 899 Australian Cattle Dogs.
Results
Auditory function was tested in 899 Australian Cattle Dogs in family groups using brainstem auditory evoked response testing. Coat colour and patterns, facial and body markings, gender and parental hearing status were recorded.
Deafness prevalence among all 899 dogs was 10.8% with 7.5% unilaterally deaf, and 3.3% bilaterally deaf, and amongst pups from completely tested litters (n = 696) was 11.1%, with 7.5% unilaterally deaf, and 3.6% bilaterally deaf.
Univariable and multivariable analyses revealed a negative association between deafness and bilateral facial masks (odds ratio 0.2; P ≤ 0.001). Using multivariable logistic animal modelling, the risk of deafness was lower in dogs with pigmented body spots (odds ratio 0.4; P = 0.050).
No significant associations were found between deafness and coat colour.
Within unilaterally deaf dogs with unilateral facial masks, no association was observed between the side of deafness and side of mask. The side of unilateral deafness was not significantly clustered amongst unilaterally deaf dogs from the same litter. Females were at increased risk of deafness (odds ratio from a logistic animal model 1.9; P = 0.034) after adjusting for any confounding by mask type and pigmented body spots.
Conclusions
Australian Cattle Dogs suffer from CHSD, and this disease is more common in dogs with mask-free faces, and in those without pigmented body patches. In unilaterally deaf dogs with unilateral masks, the lack of observed association between side of deafness and side of mask suggests that if CHSD is due to defects in molecular pigment pathways, the molecular control of embryonic melanoblast migration from ectoderm to skin differs from control of migration from ectoderm to cochlea. In Australian Cattle Dogs, CHSD may be more common in females.
doi:10.1186/1746-6148-8-202
PMCID: PMC3489614  PMID: 23107143
2.  PTPN22 polymorphisms may indicate a role for this gene in atopic dermatitis in West Highland white terriers 
BMC Research Notes  2011;4:571.
Background
Canine atopic dermatitis is an allergic inflammatory skin disease common in West Highland white terriers. A genome-wide association study for atopic dermatitis in a population of West Highland white terriers identified a 1.3 Mb area of association on CFA17 containing canine protein tyrosine phosphatase non-receptor type 22 (lymphoid) PTPN22. This gene is a potential candidate gene for canine atopic dermatitis as it encodes a lymphoid-specific signalling mediator that regulates T-cell and possibly B-cell activity.
Findings
Sequencing of PTPN22 in three atopic and three non-atopic West Highland white terriers identified 18 polymorphisms, including five genetic variants with a bioinformatically predicted functional effect. An intronic polymorphic repeat sequence variant was excluded as the cause of the genome-wide association study peak signal, by large-scale genotyping in 72 West Highland white terriers (gene-dropping simulation method, P = 0.01).
Conclusions
This study identified 18 genetic variants in PTPN22 that might be associated with atopic dermatitis in West Highland white terriers. This preliminary data may direct further study on the role of PTPN22 in this disease. Large scale genotyping and complementary genomic and proteomic assays would be required to assess this possibility.
doi:10.1186/1756-0500-4-571
PMCID: PMC3271996  PMID: 22208456
3.  Real-time PCR quantification of the canine filaggrin orthologue in the skin of atopic and non-atopic dogs: a pilot study 
BMC Research Notes  2011;4:554.
Background
Canine atopic dermatitis (AD) is a common inflammatory skin disease associated with defects in the epidermal barrier, particularly in West Highland white terriers (WHWTs). It shares many similarities with human AD, and so may be a useful animal model for this disease. Epidermal dysfunction in human AD can be caused by mutations in the gene encoding the epidermal protein filaggrin (FLG) and, in some atopic patients, be associated with altered FLG mRNA and protein expression in lesional and/or non-lesional skin. In experimental models of canine AD, mRNA expression of the orthologous canine filaggrin gene may be reduced in non-lesional skin compared with healthy controls. However, there is no published data on canine filaggrin mRNA expression in the skin of dogs with naturally-occurring AD. Hence, the aim of this pilot study was to develop a reverse transcriptase real-time PCR assay to compare filaggrin mRNA expression in the skin of atopic (n = 7) and non-atopic dogs (n = 5) from five breeds, including eight WHWTs.
Findings
Overall, filaggrin mRNA expression in non-lesional atopic skin was decreased compared to non-lesional non-atopic skin (two fold change); however this difference was only statistically significant in the subgroup of WHWTs (P = 0.03).
Conclusions
Although limited by the small sample size, these results indicate that, comparable to some cases of human AD, altered filaggrin mRNA expression may exist in the skin of some atopic dogs with naturally-occurring disease. Additional studies, including larger sample numbers, will be necessary to confirm this finding and to investigate whether mutations in the filaggrin gene exist and contribute to epidermal lesions of AD in dogs.
doi:10.1186/1756-0500-4-554
PMCID: PMC3339370  PMID: 22188733
4.  Molecular evidence of Rickettsia felis infection in dogs from northern territory, Australia 
Parasites & Vectors  2011;4:198.
The prevalence of spotted fever group rickettsial infection in dogs from a remote indigenous community in the Northern Territory (NT) was determined using molecular tools. Blood samples collected from 130 dogs in the community of Maningrida were subjected to a spotted fever group (SFG)-specific PCR targeting the ompB gene followed by a Rickettsia felis-specific PCR targeting the gltA gene of R. felis. Rickettsia felis ompB and gltA genes were amplified from the blood of 3 dogs. This study is the first report of R. felis infection in indigenous community dogs in NT.
doi:10.1186/1756-3305-4-198
PMCID: PMC3214141  PMID: 21989454
5.  A Non-Synonymous Mutation in the Canine Pkd1 Gene Is Associated with Autosomal Dominant Polycystic Kidney Disease in Bull Terriers 
PLoS ONE  2011;6(7):e22455.
Polycystic Kidney Disease is an autosomal dominant disease common in some lines of Bull Terriers (BTPKD). The disease is linked to the canine orthologue of human PKD1 gene, Pkd1, located on CFA06, but no disease-associated mutation has been reported. This study sequenced genomic DNA from two Bull Terriers with BTPKD and two without the disease. A non-synonymous G>A transition mutation in exon 29 of Pkd1 was identified. A TaqMan® SNP Genotyping Assay was designed and demonstrated the heterozygous detection of the mutation in 47 Bull Terriers with BTPKD, but not in 102 Bull Terriers over one year of age and without BTPKD. This missense mutation replaces a glutamic acid residue with a lysine residue in the predicted protein, Polycystin 1. This region of Polycystin 1 is highly conserved between species, and is located in the first cytoplasmic loop of the predicted protein structure, close to the PLAT domain and the second transmembrane region. Thus, this change could alter Polycystin 1 binding or localization. Analytic programs PolyPhen 2, Align GVGD and SIFT predict this mutation to be pathogenic. Thus, BTPKD is associated with a missense mutation in Pkd1, and the application of this mutation specific assay could reduce disease transmission by allowing diagnosis of disease in young animals prior to breeding.
doi:10.1371/journal.pone.0022455
PMCID: PMC3144903  PMID: 21818326
6.  A Randomised Controlled Trial of Ion-Exchange Water Softeners for the Treatment of Eczema in Children 
PLoS Medicine  2011;8(2):e1000395.
In a randomized trial evaluating the effect of installation of ion-exchange water softeners in the households of children with eczema, the researchers found no evidence of improvement in eczema severity as compared to usual care in the study population.
Background
Epidemiological studies and anecdotal reports suggest a possible link between household use of hard water and atopic eczema. We sought to test whether installation of an ion-exchange water softener in the home can improve eczema in children.
Methods and Findings
This was an observer-blind randomised trial involving 336 children (aged 6 months to 16 years) with moderate/severe atopic eczema. All lived in hard water areas (≥200 mg/l calcium carbonate). Participants were randomised to either installation of an ion-exchange water softener plus usual eczema care, or usual eczema care alone. The primary outcome was change in eczema severity (Six Area Six Sign Atopic Dermatitis Score, SASSAD) at 12 weeks, measured by research nurses who were blinded to treatment allocation. Analysis was based on the intent-to-treat population. Eczema severity improved for both groups during the trial. The mean change in SASSAD at 12 weeks was −5.0 (20% improvement) for the water softener group and −5.7 (22% improvement) for the usual care group (mean difference 0.66, 95% confidence interval −1.37 to 2.69, p = 0.53). No between-group differences were noted in the use of topical corticosteroids or calcineurin inhibitors.
Conclusions
Water softeners provided no additional benefit to usual care in this study population. Small but statistically significant differences were found in some secondary outcomes as reported by parents, but it is likely that such improvements were the result of response bias, since participants were aware of their treatment allocation. A detailed report for this trial is also available at http://www.hta.ac.uk.
Trial registration
Current Controlled Trials ISRCTN71423189
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Eczema (sometimes referred to as atopic dermatitis) is a chronic, inflammatory skin condition that affects about 20% of school children in developed countries. Eczema is often associated with other conditions, such as asthma, hay-fever and food allergy and can cause intractable itching leading to thickened skin, bleeding, secondary infection, sleep loss, poor concentration, and psychological distress. Current topical treatments for eczema have side effects, for example, topical corticosteroids may cause skin thinning and the long term safety of topical tacrolimus and pimecrolimus has yet to be determined. Therefore, there is a lot of interest in exploring the benefits of non-pharmacological treatments that have no apparent side effects.
Water hardness (≥200 mg/l calcium carbonate) has become a recent focus of attention.
Why Was This Study Done?
In addition to some epidemiological evidence linking increased water hardness with increased eczema prevalence, there have been widespread anecdotal reports of improvement in the skin of children with eczema when the family has moved from a hard to a soft water area. In addition, some patients report how their eczema symptoms have rapidly improved following the installation of a water softener. However, to date there have been no relevant published trials evaluating the potential benefit of water softeners for eczema. Given the lack of evidence, the high public interest in their potential benefit and the low risk of adverse effects, the researcher conducted a study to assess whether the installation of an ion-exchange water softener reduces the severity of eczema in children with moderate to severe eczema.
What Did the Researchers Do and Find?
The researchers did a pilot study that showed that it was not possible to blind participants to their treatment allocation using real and “dummy” water softener units because the softened water produced more soap suds. So the researchers conducted an observer-blind randomised controlled trial in which they used trained research nurses to conduct an objective assessment of every participant's skin. The researchers recruited 336 children who all lived in hard water areas in England. Eligible children were aged 6 months to 16 years who had a diagnosis of eczema (in line with the UK working party's diagnostic criteria) and an eczema severity score of 10 or over. Participants were randomised to either installation of an ion-exchange water softener plus usual eczema care, or usual eczema care alone. Trained research nurses examined each child's skin at baseline and at 6, 12, and 16 weeks to record changes in eczema severity. The researchers also analysed any changes in symptoms over the study period such as, sleep loss and itchiness, the amount of topical corticosteroid/calcineurin inhibitors used, the Dermatitis Family Impact questionnaire and the health related Quality of Life (children's version).
Although both treatment groups improved in disease severity during the course of the trial, the researchers found no difference between the treatment groups in the main outcome—eczema severity. Similar finding were found for night movement (scratching) and the use of topical medications (creams/ointments applied to the skin), both of which were blinded to intervention status. Nevertheless, parents in the trial did report small health benefits, and just over 50% chose to buy the water softener at the end of the trial because of perceived improvements in the eczema and the wider benefits of water softeners. It is unclear how much of this effect can be explained by prior belief in the effectiveness of the water softeners for the treatment of eczema.
What Do These Findings Mean?
The results of this study suggest that water softeners provide no additional clinical benefit to usual care in children with eczema so the use of ion-exchange water softeners for the treatment of moderate to severe eczema in children should not be recommended. However, it is up to each family to decide whether or not the wider benefits of installing a water softener in their home are sufficient to consider buying one.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000395.
The UK's NHS presents information on eczema for patients and families
MedlinePlus gives information for patients, families, and caregivers on eczema and other similar conditions
The National Eczema Society in the UK provides information and a helpline for eczema patients, families, and caregivers
Medinfo provides information for eczema patients
Wikipedia has more information about water softening (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
doi:10.1371/journal.pmed.1000395
PMCID: PMC3039684  PMID: 21358807
7.  Congenital Sensorineural Deafness in Australian Stumpy-Tail Cattle Dogs Is an Autosomal Recessive Trait That Maps to CFA10 
PLoS ONE  2010;5(10):e13364.
Background
Congenital sensorineural deafness is an inherited condition found in many dog breeds, including Australian Stumpy-tail Cattle Dogs (ASCD). This deafness is evident in young pups and may affect one ear (unilateral) or both ears (bilateral). The genetic locus/loci involved is unknown for all dog breeds. The aims of this study were to determine incidence, inheritance mechanism, and possible association of congenital sensorineural deafness with coat colour in ASCD and to identify the genetic locus underpinning this disease.
Methodology/Principal Findings
A total of 315 ASCD were tested for sensorineural deafness using the brain stem auditory evoked response (BAER) test. Disease penetrance was estimated directly, using the ratio of unilaterally to bilaterally deaf dogs, and segregation analysis was performed using Mendel. A complete genome screen was undertaken using 325 microsatellites spread throughout the genome, on a pedigree of 50 BAER tested ASCD in which deafness was segregating. Fifty-six dogs (17.8%) were deaf, with 17 bilaterally and 39 unilaterally deaf. Unilaterally deaf dogs showed no significant left/right bias (p = 0.19) and no significant difference was observed in frequencies between the sexes (p = 0.18). Penetrance of deafness was estimated as 0.72. Testing the association of red/blue coat colour and deafness without accounting for pedigree structure showed that red dogs were 1.8 times more likely to be deaf (p = 0.045). The within family association between red/blue coat colour and deafness was strongly significant (p = 0.00036), with red coat colour segregating more frequently with deafness (COR = 0.48). The relationship between deafness and coat speckling approached significance (p = 0.07), with the lack of statistical significance possibly due to only four families co-segregating for both deafness and speckling. The deafness phenotype was mapped to CFA10 (maximum linkage peak on CFA10 −log10 p-value = 3.64), as was both coat colour and speckling. Fine mapping was then performed on 45 of these 50 dogs and a further 48 dogs (n = 93). Sequencing candidate gene Sox10 in 6 hearing ASCD, 2 unilaterally deaf ASCD and 2 bilaterally deaf ASCD did not reveal any disease-associated mutations.
Conclusions
Deafness in ASCD is an incompletely penetrant autosomal recessive inherited disease that maps to CFA10.
doi:10.1371/journal.pone.0013364
PMCID: PMC2953516  PMID: 20967282

Results 1-7 (7)