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B Catchpole

Publications and source records attributed to B Catchpole.

At least 19 recordsLinked to original sources
PubMed2006

Matrix metalloproteinase mRNA expression in canine anal furunculosis lesions.

Although the aetiology of anal furunculosis (AF) in dogs is poorly understood, there is evidence for an underlying immune dysfunction. This is illustrated by the presence of a T helper type 1 cytokine mRNA profile in AF lesions and the clinical response to ciclosporin therapy. Expression of MMPs 2, 9 and 13 were evaluated in AF lesional biopsies by real-time quantitative RT-PCR. There was significantly increased expression of both MMP-9 and MMP-13 mRNA in AF biopsies compared to controls (p<0.001) but no significant difference in MMP-2 mRNA expression. Since MMP-9 and MMP-13 are primarily produced by macrophages, these data suggest that ulceration could be the result of aberrant activation of this cell type in the tissues. It is feasible that such pathological macrophage activity occurs in response to interferon-gamma secreted by T helper type 1 cells. This could explain why the lesions resolve following treatment with the immunosuppressive drug ciclosporin.

Animals↗
PubMed2006

Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele.

Dogs exhibit a range of immune-mediated conditions including a lymphocytic thyroiditis which has many similarities to Hashimoto's thyroiditis in man. We have recently reported an association in Doberman Pinschers between canine hypothyroidism and a rare DLA class II haplotype that contains the DLA-DQA1*00101 allele. We now report a further series of 173 hypothyroid dogs in a range of breeds where a significant association with DLA-DQA1*00101 is shown.

Alleles↗
PubMed2006

Identification of susceptibility and protective major histocompatibility complex haplotypes in canine diabetes mellitus.

Diabetes mellitus occurs spontaneously in dogs, which is believed to have an autoimmune component and to be a model of human latent autoimmune diabetes of adults (LADA). Some dog breeds (e.g. Samoyed) are particularly predisposed, whereas others (e.g. Boxer) are highly resistant. With the completion of the Dog Genome Assembly, comparative genomic studies of complex diseases in dogs, including diabetes, could provide an important investigative approach into such disorders. Type 1 diabetes in humans is strongly associated with major histocompatibility complex (MHC) class II polymorphisms. We have investigated whether canine dog leucocyte antigen (DLA) class II haplotypes are associated with diabetes. DNA from 460 cases and 1047 controls were genotyped for DLA-DRB1, DLA-DQA1 and DLA-DQB1 using sequence-based typing. Three DLA haplotypes, DRB1*009/DQA1*001/DQB1*008, DRB1*015/DQA1*0061/DQB1*023 and DRB1*002/DQA1*009/DQB1*001, were found at significantly increased frequency in cases with diabetes compared with controls. One DLA-DQ haplotype, DQA1*004/DQB1*013, was significantly reduced in cases with diabetes. Further analysis showed that DQA1 alleles carrying arginine at codon 55 of DQA1 were increased in dogs with diabetes. To our knowledge, this is the first report of a comparative study of MHC and diabetes in a non-rodent species. Since no laboratory model of LADA exists and dogs and humans share similar environments, further research into canine diabetes is warranted.

Alleles↗
PubMed2005

Canine diabetes mellitus: can old dogs teach us new tricks?

BACKGROUND: Diabetes is common in dogs, with an estimated prevalence of 0.32% in the UK. Clinical signs, as in man, include polydipsia, polyuria and weight loss, associated with hyperglycaemia and glucosuria. Diabetes typically occurs in dogs between 5 and 12 years of age, and is uncommon under 3 years of age. Breeds predisposed to diabetes include the Samoyed, Tibetan Terrier and Cairn Terrier, while others such as the Boxer and German Shepherd Dog seem less susceptible. These breed differences suggest a genetic component, and at least one dog leucocyte antigen haplotype (DLA DRB1*009, DQA1*001, DQB1*008) appears to be associated with susceptibility to diabetes. METHODS: Canine diabetes can be classified into insulin deficiency diabetes (IDD), resulting from a congenital deficiency or acquired loss of pancreatic beta cells, or insulin resistance diabetes resulting mainly from hormonal antagonism of insulin function. RESULTS: There is no evidence for a canine equivalent of human type 2 diabetes. Adult-onset IDD, requiring insulin therapy, is the most common form, with pancreatitis and/or immune-mediated beta cell destruction considered to be the major underlying causes of the disease. DISCUSSION: Autoantibodies to insulin, recombinant canine GAD65 and/or canine islet antigen-2 have been identified in a proportion of newly diagnosed diabetic dogs, suggesting that autoimmunity is involved in the pathogenesis of disease in some patients. CONCLUSION: The late onset and slow progression of beta cell dysfunction in canine diabetes resembles latent autoimmune diabetes of the adult in man.

Age Factors↗
PubMed2005

Study of 253 dogs in the United Kingdom with diabetes mellitus.

Clinical information and blood samples were collected from 253 dogs with naturally occurring diabetes mellitus. Over half of them were labrador retrievers, collies, Yorkshire terriers or crossbred dogs, and approximately 80 per cent of them were diagnosed between the ages of five and 12 years. The majority of the dogs were receiving insulin therapy once a day, but in the dogs receiving insulin injections twice a day there was a trend for lower serum fructosamine concentrations, suggesting better glycaemic control. The proportion of female dogs with diabetes was lower than in previous surveys. The disease was diagnosed more commonly in the winter months, a seasonal pattern also observed in human beings with diabetes, suggesting that similar environmental factors might be involved in the disease.

Age Factors↗
PubMed2005

Canine serum immunoreactivity to M. pachydermatis in vitro is influenced by the phase of yeast growth.

In western immunoblotting studies of canine sera using Malassezia pachydermatis extracts, the reported patterns of immunoreactivity vary between different laboratories. Because the duration of culture influences the antigenic composition of lipid-dependent Malassezia spp. when probed with human sera, we investigated whether the in vitro growth phase of M. pachydermatis influences immunoreactivity using canine sera. Extracts of M. pachydermatis CBS 1879 grown in Sabouraud's liquid medium at 37 degrees C for 2, 4, 6, 8 and 10 days were prepared by mechanical disruption, centrifugation, dialysis and lyophilization. Yeast growth phase was assessed by sequential colony counts and optical density measurements. Patterns of IgG immunoreactivity in high (n = 3) and low (n = 3) titre sera were compared using extracts prepared at each time point by sodium dodecyl sulphate polyacrylamide gel electrophoresis and western immunoblotting. Protein bands of 62 and 49 kDa were recognized by all sera, and 98 and 68 kDa bands were recognized by five sera. Proteins of 188, 66, 58, 57, 38, 28 and 17 kDa were only recognized by high titre sera. All high titre sera used recognized more bands in exponential phase (d2) extracts when compared with decline phase (d8-d10) extracts, and two of these sera showed most bands in stationary phase (d4-d6) extracts. Bands of 62 and 57 kDa were primarily detected in exponential and early stationary phase extracts. There is variation in antigenic expression in different growth phases of M. pachydermatis, which might explain discrepancies between previous laboratory studies of canine immunity to this yeast.

Animals↗
PubMed2003

Expression of cytokine mRNA in canine anal furunculosis lesions.

The pattern of expression of cytokine mRNA in the lesions of anal furunculosis was evaluated in tissue biopsies from 15 dogs, and compared with the pattern in control skin samples from 24 dogs, by reverse-transcriptase PCR using canine cytokine-specific primers and a semi-quantitative multiplex PCR assay. Interleukin-2 (IL-2) was detected in 11 of the 15 affected dogs but in only one of the controls, and interferon-gamma was detected in 14 of the affected dogs but none of the controls. In contrast, IL-4 was detected only in one of the affected dogs. Increased expression of mRNA for IL-1beta, IL-6, tumour necrosis factor alpha, IL-8, IL-10 and transforming growth factor beta1 was detected in the biopsies from the lesions of anal furunculosis relative to the control tissues (P < 0.05).

Animals↗
PubMed2003

Evaluation of a continuous glucose monitoring system in diabetic dogs.

The generation of a blood glucose curve is important for assessing the response to insulin therapy in diabetic dogs. Disadvantages of this technique include patient discomfort and the potential for missing transient hypo- or hyperglycaemic episodes. The aim of the current study was to evaluate a continuous glucose monitoring system (CGMS) for use in diabetic dogs. Interstitial fluid glucose concentrations were recorded in 10 diabetic dogs, every five minutes for up to 48 hours, using a subcutaneous sensor attached to the CGMS device. Blood glucose concentrations were measured simultaneously using a glucometer. The correlation between interstitial fluid and blood glucose values was 0.81 (P < 0.01). The largest discrepancies between the two sets of data were seen during the one- to three-hour period following feeding, suggesting that postprandial hyperglycaemia might not be reflected in the interstitial fluid. The authors conclude that the CGMS is a potentially valuable tool in the management of canine diabetic patients.

Animals↗
PubMed2002

Immunosuppressive cytokines in the regional lymph node of a dog suffering from oral malignant melanoma.

A 10-year-old male cross-breed dog was referred for investigation of oral malignant melanoma. Fine-needle aspirates were taken from the draining submandibular lymph node. The presence of metastatic melanoma cells was confirmed by cytological examination and reverse transcription polymerase chain reaction (RT-PCR) using primers for the melanoma-associated antigens: tyrosinase and mart-1/melan A. Cytokine expression in the lymph node was evaluated by multiplex RT-PCR, which demonstrated the presence of mRNA for IL-10 and TGF-beta1. However, IL-2, IL-4 and IFNgamma mRNA could not be detected, suggesting a lack of immune activation. Thoracic radiographs showed a lesion within the caudal lung fields suggestive of pulmonary metastasis. The dog developed signs of dyspnoea and collapse and was euthanased four days later. This case illustrates that molecular techniques can be used to aid clinical staging of canine oral malignant melanoma, and suggests that immunosuppressive cytokines could be involved in the pathogenesis of disease.

Animals↗
PubMed2002

Evaluation of two point-of-care analysers for measurement of fructosamine or haemoglobin A1c in dogs.

Measurement of glycosylated proteins such as fructosamine and haemoglobin A1c (HbA1c) can be used to assess glycaemic control in canine diabetic patients. Two point-of-care analysers, designed for human diabetics, were evaluated for use in dogs. Blood samples were collected from 50 normoglycaemic dogs, 100 diabetic patients and five dogs with insulinoma and tested using the In Charge fructosamine meter and the Haemaquant/Glycosal HbA1c meter. Readings were obtained in all cases except for 21 of 50 diabetics, which were above the upper limit of the In Charge meter. Diabetic dogs had higher fructosamine and HbA1c concentrations compared to controls. However, there was poor agreement between the In Charge meter readings and serum fructosamine concentrations, suggesting that there are problems associated with the use of this device in dogs. HbA1c concentrations showed a high degree of correlation with glycosylated haemoglobin measured at an external laboratory, suggesting that the Haemaquant/Glycosal meter warrants further evaluation for veterinary use.

Animals↗
PubMed2001

T cell lines generated with type II collagen proliferate in an autologous mixed lymphocyte response.

Collagen-induced arthritis (CIA) is a T cell-dependent disease induced in susceptible rodents by immunizing with bovine type II collagen (bCII). In order to study T cell responses, a programme to generate bCII-specific T cell lines from arthritic rats was initiated. Lymph node cells from bCII-immune WA/KIR/kcl rats were cultured with bCII in vitro, and the T cells were isolated and restimulated with bCII-pulsed antigen presenting cells (APC) (thymus cells or splenic low density cells). However, T cells, generated initially to bCII, subsequently proliferated upon co-culture with syngeneic APC even in the absence of bCII. This suggests that exposure to bCII resulted in the activation of a population of self-reactive T cells which proliferate in an autologous mixed lymphocyte response. In contrast, short-term T cell lines generated to ovalbumin, heat-denatured bCII and the collagen peptide bCII(184-198) proliferated in response to specific antigen-pulsed APC without demonstrating self-reactivity. Since denatured bCII and bCII(184-198) peptide are not arthritogenic and failed to generate self reactivity in vitro, this suggests that the native triple helical conformation of bCII is required for stimulating autoreactive T cell responses.

Amino Acid Sequence↗
PubMed2001

Antigen presentation of Type II collagen in rats.

Collagen-induced arthritis (CIA) is a T-cell dependent disease of rats which follows immunization with bovine type II collagen (bCII). Susceptibility to CIA is linked to the genes encoding the major histocompatibility complex (MHC), suggesting that antigen presentation is important in disease pathogenesis. Antigen-presenting cells (APC) (macrophages, dendritic cells (DC) and B cells) were prepared from WA/KIR/KCL rats and presentation of antigen, in the form of native protein (bCII) or synthetic peptide (bCII:184-198), was assessed in T-cell proliferation assays. Whilst macrophages inhibited proliferative responses to bCII, splenic or thymic low density cells, enriched for DC, presented both bCII and bCII(184-198) peptide. However, bone marrow-derived DC, which stimulated T-cell responses to OVA, failed to present bCII, suggesting differences in processing of these two antigens. B-cell depletion from lymph node cells abrogated the proliferative response to bCII and reconstitution of a T-cell population with B cells restored the proliferative response, indicating that B cells are important for stimulating T-cell responses to bCII. B cells play a critical role in CIA by producing pathogenic anti-bCII antibodies, and we propose that B cells are also important APC which present bCII to CD4+ T cells.

Animals↗
PubMed1981

Wound infection.

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Humans↗