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M J Day

Publications and source records attributed to M J Day.

At least 55 records · Page 3Linked to original sources

Phylogenetic analysis of hemoplasma species: an international study.

Nearly complete 16S rRNA gene sequences for feline and canine hemoplasma isolates from Europe, Australia, Africa, and Asia showed almost 100% identity to those previously reported for United States isolates. Partial sequences of the RNA subunit of the RNase P gene were also determined, and RNase P-based phylogenetic analysis showed that the hemoplasmas are most closely related to the members of the Mycoplasma pneumoniae group.

Africa↗

Prevalence of Bartonella species causing bacteraemia in domesticated and companion animals in the United Kingdom.

Between October 1999 and February 2000, 691 blood samples examined routinely for either haematological or virological assessment were screened by culture for the presence of Bartonella species. They came from 615 animals: 360 cats, 211 dogs, 27 horses, 16 cattle and a gorilla. The samples were incubated for long periods on 10 per cent horse blood agar at 37 degrees C in an atmosphere containing 5 per cent carbon dioxide. Isolates were obtained from 35 samples from 34 (9.4 per cent) of the cats, but not from any of the other animals. Comparison of citrate synthase gene sequences from the isolates indicated that they were all Bartonella henselae. Analysis of 16S rRNA gene fragments indicated that 30 of the cats were infected solely with B henselae genotype II, two were infected solely with B henselae genotype I and two were infected with both genotypes.

Animals↗

Extensive interbreed, but minimal intrabreed, variation of DLA class II alleles and haplotypes in dogs.

The DLA class II genes in the dog major histocompatibility complex are highly polymorphic. To date, 52 DLA-DRB1, 16 DLA-DQA1 and 41 DLA-DQB1 allelic sequences have been assigned. The aim of this study was to examine the intrabreed and interbreed variation of DLA allele and haplotype frequencies in dogs, and to ascertain whether conserved DLA class II haplotypes occur within and between different breeds. One thousand and 25 DNA samples from over 80 different breeds were DLA class II genotyped, the number of dogs per breed ranging from 1 to 61. DNA sequence based typing and sequence specific oligonucleotide probing were used to characterize dogs for their DLA-DRB1, DQA1 and DQB1 alleles. The high frequency of DLA class II homozygous animals (35%), allowed the assignment of many haplotypes despite the absence of family data. Four new DLA alleles were identified during the course of this study. Analysis of the data revealed considerable interbreed variation, not only in allele frequency, but also in the numbers of alleles found per breed. There was also considerable variation in the number of breeds in which particular alleles were found. These interbreed variations were found in all three DLA class II loci tested, and also applied to the three-locus haplotypes identified. Within this data set, 58 different DLA-DRB1/DQA1/DQB1 three-locus haplotypes were identified, which were all found in at least two different animals. Some of the haplotypes appeared to be characteristic of certain breeds. The high interbreed, and relatively low intrabreed, variation of MHC alleles and haplotypes found in this study could provide an explanation for reports of interbreed variation of immune responses to vaccines, viruses and other infections.

Alleles↗

Immunohistochemical characterization of tuberculous and non-tuberculous lesionsin naturally infected European badgers (Meles meles).

A panel of species cross-reactive antibodies was established for the immunohistochemical labelling of phagocytic and lymphoid cells in formalin-fixed normal badger tissues. These reagents were used to investigate the immunopathogenesis of both tuberculous and non-tuberculous granulomas in badgers. In normal badger tissues, antisera specific for the CD79a and CD79b epitopes strongly labelled follicular B lymphocytes and plasma cells in lymph nodes, bronchus-associated lymphoid tissue and Peyer's patches. Rabbit anti-dog IgG, IgM and IgA, and goat anti-human lambda light chain strongly labelled plasma cells, but goat anti-ferret IgA produced weak labelling. Interfollicular and occasional follicular lymphocytes and gut intraepithelial lymphocytes expressed the CD3 epitope. Mouse anti-human HLA-DR (MHC Class II) antigen strongly labelled macrophages, some follicular lymphocytes and some intestinal and respiratory epithelial cells. Mouse anti-human calprotectin (MAC387) labelled a limited number of macrophages. In infected badgers, all fusiform to angular macrophages (epithelioid cells) of all tuberculous granulomas strongly expressed HLA-DR antigen, but only a small, variable proportion of these were labelled by MAC387 antiserum. Lymphocytes in the peripheral rims of granulomas and those scattered sparsely amongst the epithelioid cells were labelled primarily with CD3 antiserum. Peripheral plasma cells were more common in larger than in smaller tubercles and usually expressed IgA or IgG. Small unencapsulated siliceous granulomas, which were present in both tuberculous and non-tuberculous badgers, consisted of aggregates of round to polyhedral epithelioid cells expressing the MHC Class II but not the MAC387 epitope. Granulomas caused by infection with presumed fungal adiaspores of Chrysosporium sp. consisted of aggregates of variably shaped macrophages that expressed MHC Class II antigen, but only a proportion expressed MAC387 antigen. The majority of lymphocytes within the peripheral rims of these granulomas were T cells, accompanied by sparse to moderate numbers of plasma cells that primarily expressed IgG or IgA. In conclusion, species cross-reactive antibodies can be used to identify the cellular components of tuberculous and non-tuberculous granulomas. Immunohistochemical examination failed to distinguish small tuberculous granulomas from adiaspiromycotic granulomas.

Animals↗

Expression of chemokine receptors in the feline reproductive tract and large intestine.

Feline immunodeficiency virus (FIV) is a lentivirus that causes feline acquired immunodeficiency syndrome. Infection can be transmitted experimentally via the vagina and rectum, making the cat a useful model for human immunodeficiency virus (HIV) infection. Some strains of FIV use the CXCR4 chemokine receptor in vitro to gain entry to feline cell lines, thymocytes and peripheral blood leucocytes (PBLs). In this study, the tissue expression of messenger ribonucleic acid (mRNA) encoding the CCR3, CXCR4 and CCR5 receptors was examined by reverse transcriptase polymerase chain reaction (RT-PCR). mRNA encoding each receptor was expressed by two feline T-cell lines (Mya-1 and FeTJ), a feline kidney fibroblast cell line (FKCU) and PBLs. Mesenteric lymph node, colon, rectum, uterus, cervix and vagina all expressed mRNA for CXCR4 and CCR5 whilst only lymph node expressed CCR3 mRNA. In order to locate this receptor mRNA expression, in-situ hybridization studies were performed with DNA probes specific for the chemokine receptor mRNAs. CCR5 and CXCR4 receptor mRNA was expressed by epithelial cells and some lamina propria cells of the colon and rectum. Epithelial cell expression of chemokine receptor mRNA was reduced in intensity towards the base of the crypts. Expression of CXCR4 receptor was also demonstrated immunohistochemically on some lamina propria and intraepithelial cells. The expression of these receptor molecules may be important in mucosal infection with FIV.

Animals↗

Eosinophilic diseases in two Cavalier King Charles spaniels.

This report describes the clinical presentation of two Cavalier King Charles spaniels with different eosinophilic diseases. The first case presented with dyspnoea and a non-productive cough, and investigations demonstrated eosinophilic bronchopneumonopathy. The second dog was referred for the investigation of haemorrhagic vomiting and diarrhoea and was eventually diagnosed with eosinophilic enteritis. Both dogs had concurrent eosinophilic stomatitis, and both responded completely to immunosuppressive glucocorticoid therapy. This report is the first to describe the concurrence of eosinophilic stomatitis and systemic eosinophilic disease in Cavalier King Charles spaniels, and suggest that this breed may be predisposed to eosinophilic syndromes.

Animals↗

Immunohistochemical characterisation of the lesions of canine idiopathic pericarditis.

Pericardial tissue was obtained from 14 dogs with idiopathic pericarditis, and from three dogs with pericardial effusion associated with neoplastic disease, for histopathological assessment and characterisation of infiltrating leucocytes by immunohistochemistry. The major pathological change was extensive pericardial fibrosis which was generally accompanied by a mixed inflammatory response that was of greatest intensity at the cardiac surface of the tissue. Perivascular lymphoplasmacytic aggregates were present at the pleural surface and within the fibrosed pericardium. There were no features that clearly distinguished the samples from dogs with neoplastic disease from dogs with idiopathic pericarditis. The pericardial infiltrates were dominated by MAC 387+ monocyte-macrophages and plasma cells expressing immunoglobulin (Ig)A or IgG. CD3+ T lymphocytes and major histocompatibility complex (MHC) class II+ macrophages were less common, although the perivascular aggregates were mixtures of T and B lymphocytes and a proportion of fibroblasts expressed MHC class II. There was no vascular pathology or deposition of immunoglobulin or complement within vessel walls. These findings are consistent with an immune response dominated by humoral effector mechanisms (Th2 immunity) but do not clearly support a primary immune-mediated pathogenesis for idiopathic pericarditis.

Animals↗

Presence of immune-complexes, and absence of antinuclear antibodies, in sera of dogs naturally and experimentally infected with Ehrlichia canis.

Antinuclear antibodies (ANA), immunoglobulin G (IgG) concentrations and circulating immune-complexes (CIC) were measured, over a period of 3 years, in 6 dogs experimentally infected with Ehrlichia canis, and in 10 dogs naturally infected with the rickettsia. No ANA were detected in any of the samples tested. The IgG concentrations were shown to be higher in the infected dogs when compared to the control dogs. CIC were detected in 2 of 10 naturally and 2 of 6 experimentally infected dogs, during both the acute and the subclinical phases of the disease. The results of this study suggest that ANA do not play a role in the pathogenesis of CME. It is however suggested that some manifestations in canine ehrlichiosis are immune-complex mediated.

Animals↗

Histological evidence of disease in wild stoats (Mustela erminea) in England.

Forty-four free-living stoats were collected from five game estates in England and examined for evidence of disease. All the macroscopic lesions were attributable to the trauma associated with being trapped or shot. There were no significant microscopic lesions in 27 (61 per cent) of the stoats. There was evidence of nematode parasitism in the intestines of six stoats (14 per cent), and in the lungs of five stoats (11 per cent), and of pulmonary granulomatous inflammation or microgranulomas in five stoats. In two of the stoats, blood-filled cavities in the liver were suggestive of peliosis hepatis, possibly associated with infection by Bartonella species or with sublethal exposure to anticoagulant rodenticides.

Animals↗

16S rDNA comparison demonstrates near identity between an United Kingdom Haemobartonella felis strain and the American California strain.

A handful of North American (USA) strains of the uncultured erythrocytotrophic pathogen of cats, Haemobartonella felis, have been differentiated by comparison of the 16S rRNA gene sequences. Using this approach, an UK strain was characterised, providing an identity for a non-USA H. felis for the first time. This strain shared close phylogenetic homology with the USA Californian strain.

Anaplasmataceae↗

Tissue cytokine responses in canine visceral leishmaniasis.

To elucidate the local tissue cytokine response of dogs infected with Leishmania chagasi, cytokine mRNA levels were measured in bone marrow aspirates from 27 naturally infected dogs from Brazil and were compared with those from 5 uninfected control animals. Interferon-gamma mRNA accumulation was enhanced in infected dogs and was positively correlated with humoral (IgG1) but not with lymphoproliferative responses to Leishmania antigen in infected dogs. Increased accumulation of mRNA for interleukin (IL)-4, IL-10, and IL-18 was not observed in infected dogs, and mRNA for these cytokines did not correlate with antibody or proliferative responses. However, infected dogs with detectable IL-4 mRNA had significantly more severe symptoms. IL-13 mRNA was not detectable in either control or infected dogs. These data suggest that clinical symptoms are not due to a deficiency in interferon-gamma production. However, in contrast to its role in human visceral leishmaniasis, IL-10 may not play a key immunosuppressive role in dogs.

Actins↗

Tick-borne infectious diseases of dogs.

Tick-transmitted infections are an emerging problem in dogs. In addition to causing serious disease in traditional tropical and semi-tropical regions, they are now increasingly recognized as a cause of disease in dogs in temperate climates and urban environments. Furthermore, subclinically infected companion animals could provide a reservoir for human tick-transmitted infectious agents, such as Ehrlichia chaffeensis, Ehrlichia ewingll, the Ehrlichia phagocytophila group and Rickettsia conorii. Here, we discuss the emergence of new canine tick-transmitted diseases, which results from several factors, including the expansion of the tick range into urban and semi-urban areas worldwide, the movement of infected dogs into previously non-endemic areas, and the advent of novel molecular techniques for diagnosis and pathogen identification.

Animals↗

Hypercalcaemia associated with chronic lymphocytic leukaemia in a Giant Schnauzer.

A 7-year-old male Giant Schnauzer was referred with a history of severe vomiting, lethargy, weight loss, polydipsia and polyuria. Detailed investigations revealed leucocytosis with a marked lymphocytosis, mild non-regenerative anaemia, thrombocytopenia, hypercalcaemia and azotaemia. Circulating lymphocytes were small and well-differentiated, and the same lymphoid population was present in bone marrow. Chronic lymphocyctic leukaemia with associated paraneoplastic hypercalcaemia was diagnosed. Immunohistochemical staining of a bone marrow biopsy revealed a neoplastic B-cell line expressing CD79. The dog responded to therapy with prednisolone and chlorambucil for a period of 8 months.

Animals↗

Detection of IgG and IgE serum antibodies to Culicoides salivary gland antigens in horses with insect dermal hypersensitivity (sweet itch).

We postulated that all horses exposed to the bites of Culcoides (midges) would have an antibody response to the antigen secreted in Culcoides saliva, but that IgE antibody would be restricted to allergic individuals. Using immunohistology on sections of fixed Culicoides, we have demonstrated the presence of antibodies in horse serum which recognise Culicoides salivary glands. Antibodies were detected in the serum of horses with insect dermal hypersensitivity and in the serum of normal horses exposed to Culicoides bites. In contrast, no antibodies were detected in serum from native Icelandic ponies which had not been exposed to Culicoides. Anti-salivary gland IgG antibodies were detected in serum from both allergic and healthy horses exposed to Culicoides. IgE antibodies were only detected in horses with signs of insect dermal hypersensitivity, they were not found in serum of healthy controls nor in the serum of horses with a history of hypersensitivity but in remission at the time of sampling. Using western blotting we confirmed the presence of antibodies to Culicoides antigens and demonstrated that individual horses react to different numbers of antigens. This paper demonstrates the ability of serum from allergic horses to detect Culcoides antigens and will enable further studies to isolate and characterise the allergens.

Animals↗

Relative deficiency in IgA production by duodenal explants from German shepherd dogs with small intestinal disease.

Matched samples of serum, saliva and tears were collected from four groups of dogs; two of the groups were German shepherd dogs (GSDs) either with (Group 1) or without (Group 4) a variety of small intestinal disorders; the remaining two groups were dogs of other breeds, again with (Group 2) or without (Group 3) small intestinal disease. Capture ELISAs were used to measure IgG, IgM, IgA and albumin concentrations within these samples; intestinal humoral immune status of clinical cases was assessed by quantifying immunoglobulin production from duodenal explant cultures.There were no significant differences in IgG, IgM or IgA concentrations in serum, saliva or tears between the different groups of dog. Moreover, no significant differences were noted between groups for IgG, IgM and IgA salivary and tear secretory indices. IgA production by 24-h explant cultures was significantly lower in GSDs compared with non-GSDs with small intestinal disease (groups 1 and 2, respectively), but the numbers of lamina propria IgA(+) plasma cells in duodenal biopsies were not different between groups. These results suggest that there may be a relative deficiency in local IgA secretion in GSDs with small intestinal enteropathies, which is not reflected in either serum IgA concentrations, or in secretion at unaffected mucosal sites. It remains to be determined whether such a deficiency is a breed-related primary defect, or whether it arises secondary to the pathological processes within the intestinal mucosa.

Animals↗