Biomedical subjects

M J Day

Publications and source records attributed to M J Day.

At least 91 records · Page 5Linked to original sources

PubMed1999

The distribution of lymphocytes expressing alphabeta and gammadelta T-cell receptors, and the expression of mucosal addressin cell adhesion molecule-1 in the canine intestine.

The present study defined the distribution of alphabeta and gammadelta T-cell subsets, and the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in the intestinal tract of an outbred population of dogs with no evidence of gastrointestinal disease. A panel of monoclonal antibodies reactive with the canine alphabeta and gammadelta T-cell receptors (TCRs) and human MAdCAM-1 was used in a series of immunoperoxidase or immunofluorescence studies. alphabeta T cells were predominant within the villous lamina propria with a significantly decreasing linear trend from upper villus to crypt (P<0.0001). A proportion of intraepithelial lymphocytes (IELs) also expressed the alphabeta T-cell receptor, with significantly greater numbers in villous than in crypt epithelium (P<0.0001). However, there were no significant differences in the numbers of either lamina propria or epithelial alphabeta T cells between different intestinal regions. gammadelta T cells were rare in the lamina propria, but a prominent gammadelta IEL population was present and shown by double-colour immunofluorescence studies to be principally of the CD4(&)minus;CD8alpha(&)minus; phenotype. MAdCAM-1 was expressed by endothelial cells in the mucosa, sub-mucosa and muscularis layers of all levels of the intestinal tract. In the mucosa, significantly more MAdCAM-1 positive endothelium was present in regions of crypt than villous lamina propria (P<0.0001), but there were no significant differences between expression in different intestinal regions. The quantitative and qualitative data will enable comparisons of these parameters to be made with those in dogs suffering from inflammatory bowel diseases.

Animals↗

PubMed1999

Immunohistochemical study of the inflammatory infiltrate associated with equine squamous cell carcinoma.

The distribution of T (CD3), B (CD79) lymphocytes, immunoglobulin (IgG, IgM and IgA)-producing plasma cells, macrophages (lysozyme, Mac387) and MHC Class II antigen was analysed in the inflammatory infiltrate associated with 19 equine squamous cell carcinomas (SCCs) and six cases of precancerous lesions (actinic keratosis). The SCCs came from the penis (11 cases), conjunctiva (four), skin (two), nasal cavity (one) and oral cavity (one). Seven cases were well-differentiated and 12 moderately differentiated. Nine cases showed no invasion of peritumoral deep tissues (locally invasive), whereas the remaining 10 cases were highly invasive. An abundant inflammatory infiltrate was associated with the majority of the SCCs and with lesions of actinic keratosis. This infiltrate was composed mainly of CD3(+)T lymphocytes, CD79(+)B cells and numerous IgG(+)plasma cells; IgM- and IgA-producing plasma cells were scarce and variable, respectively. Macrophages were usually numerous. Macrophages, lymphocytes, intra-epithelial dendritic cells and fibroblasts expressed MHC Class II antigen. No significant correlation was found between the nature of the inflammatory infiltrate and the SCC histological grade or degree of invasion, suggesting that the local anti-tumour immune response failed to prevent tumour invasion or metastasis. MHC Class II was expressed by a variable number of neoplastic epithelial cells in four SCCs, all of which were only locally invasive. In addition, in areas where SCC cells expressed Class II antigen, numerous CD3(+)T lymphocytes were present and some of them were associated with degenerate tumour cells. These findings suggest that the expression of MHC Class II by neoplastic cells induces an improved local anti-tumour immune response.

Animals↗

PubMed1999

Immune-mediated haemolytic anaemia in two sibling cats associated with multicentric lymphoblastic infiltration.

Immune-mediated haemolytic anaemia associated with multicentric lymphoblastic infiltration is reported in two sibling cats. Both cats presented at under 16 months of age with clinical signs of acute anaemia. In each case there was autoagglutination, a positive Coombs' test and the anaemia was regenerative. At presentation, both cats were negative for FeLV antigen. In each case, the disease proved fatal within 2 months of the initial diagnosis. In both cases, T-lymphoblastic infiltration of bone marrow, liver and spleen was found at post-mortem examination.

Anemia, Hemolytic, Autoimmune↗

PubMed1999

Possible immunodeficiency in related rottweiler dogs.

A litter of eight rottweiler pups is described in which two dogs died before the age of six months from systemic inflammatory disease, and two further pups developed inflammatory skin disease. All seven pups tested had a markedly low serum immunoglobulin A (IgA) concentration (< 0.1 mg/ml) and six of these dogs also had subnormal serum IgG (< 0.1 to 6.4 mg/ml). Tissues taken from three diseased pups were examined immunohistochemically using a number of lymphoid markers. Secondary lymphoid tissues had a paucity of CD3+ T lymphocytes, although T cells were found within some inflammatory foci. B-lymphocyte follicles were present within lymphoid tissues, but there were irregularities of plasma cell development and a lack of plasma cells of all classes within mucosal and cutaneous sites. Inflammatory lesions were dominated by macrophages expressing class II molecules of the major histocompatibility complex. Serum immunoglobulins were also investigated in eight related, clinically normal adult dogs. Five of these dogs, from two separate breeding lines, had subnormal serum IgA (< 0.1 to 0.15 mg/ml). The spectrum of disease within the affected litter may be consistent with an underlying inherited immunological defect, and the observed immunological abnormalities suggest a more complex disorder than simple IgA deficiency.

Animals↗

PubMed1999

Determination of the prevalence of feline blood types in the UK.

The efficacy and diagnostic accuracy of a new desk-top feline blood typing kit was evaluated by comparing the results of the kit with traditional blood typing methods on 35 feline blood samples. The kit was then used to blood type 139 non-pedigree cats from Scotland and the north of England and 207 pedigree cats from throughout the UK. Of the non-pedigree cats, 87.1 per cent were type A, 7.9 per cent were type B and 5.0 per cent were type AB, while of the pedigree cats, 54.6 per cent were type A, 40.1 per cent were type B and 5.3 per cent were type AB. The majority (121 out of 207) of these pedigree cats were British shorthaired, of which 39.7 per cent were type A, 58.7 per cent were type B and 1.6 per cent were type AB. No cats were identified that failed to express the type A and/or type B antigens. The prevalence of type AB cats appears to be higher in this study than previously reported. The prevalence of blood types within specific pedigree breeds in the UK appears to vary from that reported elsewhere.

Animals↗

PubMed1999

Primary immune-mediated thrombocytopenia in a cat.

A young female Somali cat was referred for investigation of chronic intermittent haematuria. Petechiae were found on the ears and ventral abdomen and further investigation revealed severe thrombocytopenia and megakaryocyte hyperplasia. Direct marrow immunohistochemistry detected anti-megakaryocyte autoantibody (Immunoglobulin G), but extensive investigation failed to find secondary causes of immune-mediated thrombocytopenia, so a diagnosis of primary (autoimmune) immune-mediated thrombocytopenia was concluded. Thrombocytopenia persisted despite aggressive immunosuppressive therapy (prednisolone, azathioprine and vincristine) but resolved after oral prednisolone was replaced with dexamethasone.

Animals↗

PubMed1999

Measurement of titres of naturally occurring alloantibodies against feline blood group antigens in the UK.

Measurement of anti-A and anti-B haemagglutinating alloantibody titres was performed on serum samples from both pedigree (n = 61) and non-pedigree (n = 43) cats previously typed using a commercial blood typing kit. All 40 type B cats had anti-A antibody with titres ranging from 4 to 1600. Among the 61 type A sera tested, an anti-B agglutination titre of greater than 2 was recorded in 16.4 per cent. There was no significant association between serum alloantibody titre and cat breed or gender (P > 0.05).

Animals↗

PubMed1999

Cytokine mRNA expression in lesions in cats with chronic gingivostomatitis.

Semiquantitative reverse transcription-PCR assays were developed to measure feline interleukin-2 (IL-2), IL-4, IL-5, IL-6, IL-10, and IL-12 (p35 & p40); gamma interferon (IFN-gamma); and glyceraldehyde-3-phosphate dehydrogenase mRNA concentrations in biopsies of feline oral mucosa. Biopsies were collected from 30 cats with chronic gingivostomatitis (diseased) prior to each cat receiving one of four treatments. In 23 cases replicate biopsies were collected 3 months after treatment commenced. Biopsies were also analyzed from 11 cats without clinical disease (nondiseased). Expression of IL-2, IL-10, IL-12 (p35 and p40), and IFN-gamma was detected in most nondiseased biopsies, while IL-6 was detected in a minority, and IL-4 and IL-5 were both undetectable. Compared to nondiseased cats, the diseased population showed a significant increase in the relative mRNA expression of IL-2, IL-4, IL-6, IL-10, IL-12 (p35 and p40), and IFN-gamma. In contrast, IL-5 mRNA expression was unchanged and was only detected in one case. No significant relationship was demonstrable between the change in relative expression of specific cytokine mRNA and the change in clinical severity of the local mucosal lesions over the treatment period. The results demonstrate that the normal feline oral mucosa is biased towards a predominantly (Th) type 1 profile of cytokine expression and that during the development of lesions seen in feline chronic gingivostomatitis there is a shift in the cytokine profile from a type 1 to a mixed type 1 and type 2 response.

Animals↗

PubMed1998

Determination of salivary and serum immunoglobulin concentrations in the cat.

The concentrations of immunoglobulin(Ig)G, IgM, and IgA were determined in unstimulated saliva (n=14), stimulated saliva (n=6), and serum (n=14) from healthy adult cats. Analysis by single radial immunodiffusion (SRID) was compared with class-specific enzyme linked immunoassays (ELISA), and good correlation was demonstrated between the two techniques. Mean (s.d.) serum concentrations of 19.08 (5.38) mg/ml IgG, 2.04 (0.83) mg/ml IgM and 2.6 (2.16) mg/ml IgA were obtained by SRID. The immunoglobulin concentrations of the saliva samples frequently fell below the quantification limits for SRID, however, all samples could be quantified by ELISA making this the method of choice for the determination of salivary immunoglobulin concentrations. IgA was the predominant class of immunoglobulin secreted by the major feline salivary glands, and the concentration of each immunoglobulin class was greater in unstimulated versus stimulated saliva. Analysis of sequential unstimulated saliva samples collected each morning and evening over a 4-day period from four cats revealed the salivary immunoglobulin concentrations to be relatively constant.

Animals↗

PubMed1998

Immunohistochemical study of the local inflammatory infiltrate in spontaneous canine transmissible venereal tumour at different stages of growth.

In this study, the immunohistochemical distribution of CD3 (T lymphocytes), CD79 (B lymphocytes and plasma cells), IgG, IgM, IgA, IgG subclasses (IgG2, IgG3 and IgG4) L1 (macrophages) and MHC Class II antigen was analysed in the inflammatory infiltrates associated with spontaneous canine transmissible venereal tumours (CTVT) at different stages of growth. With all antibodies used, except IgM and IgA, the number of immunoreactive cells was significantly higher (p < 0.05) in the infiltrate of CTVT undergoing spontaneous regression or with stable growth (14 cases), than in tumours undergoing progressive growth (nine cases). This result suggests that T lymphocytes in addition to B cells, plasma cells expressing IgG, IgG2 and IgG4, and macrophages participate in the effective immune response against CTVT and mediate spontaneous regression of the tumour. MHC Class II antigen was expressed by infiltrating lymphocytes and macrophages, and also by fibroblasts within and around the tumours. Class II was also expressed by a variable number of neoplastic cells, particularly those in regressing or stable tumours with a marked lymphoplasmacytic infiltrate. This suggests that the expression of Class II by neoplastic cells is associated with the effective immune response and regression of CTVT.

Animals↗

PubMed1998

Measurement of IgG, IgM and IgA concentrations in canine serum, saliva, tears and bile.

Capture ELISAs, for canine IgG, IgM, IgA and albumin, were developed and used to analyse immunoglobulin (Ig) concentrations in both serum and secretions. Matched samples of serum, saliva and tears were taken from 31 dogs, assigned to two groups based on age, whilst bile samples were obtained from nine adult dogs at post-mortem. Serum and tear IgA concentrations were significantly lower in dogs < or = 12 months of age compared with dogs > 12 months of age (p = 0.006 and 0.045, respectively). There was no significant correlation between serum and secretory Ig levels, with the single exception of serum and tear IgM concentrations (rp = 0.553, p = 0.004). IgG and IgM concentrations were significantly correlated in matched tear and saliva samples (IgG: rp = 0.470, p = 0.023; IgM: rp = 0.651, p < 0.0001). Albumin concentrations were significantly correlated with IgG, but not IgM or IgA, in both saliva and tears (saliva, rp = 0.581, p = 0.004; tears, rp = 0.843, p < 0.0001) whilst IgA and IgM concentrations were significantly correlated with each other in both secretions (saliva, rp = 0.644, p = 0.001; tears, rp = 0.555, p = 0.009). Significantly, more Ig of all classes was secreted into saliva than tears as calculated by a secretory index. A large diurnal and day-to-day variation was observed in Ig concentrations in serial saliva and tear samples taken from a further four dogs. Serum Ig concentrations are therefore, poor indicators of mucosal secretion in this species and significant intra-individual variation exists in secretory Ig levels. Both findings should be taken into account in future studies of canine mucosal immunoglobulins.

Animals↗

PubMed1998

Expression of major histocompatibility complex class II antigens in the canine intestine.

Immunohistochemical techniques were used to assess major histocompatibility complex (MHC) class II expression by enterocytes and lamina propria cells in the canine intestinal tract. Duodenal enterocyte class II expression was faint and limited to the lower crypt region whereas jejunal and ileal enterocyte expression was stronger, being present in both crypt and villus areas. Enterocyte staining was of greatest intensity in crypts adjacent to Peyer's patches and intense membrane staining of most Peyer's patch lymphocytes was also seen. Enterocyte MHC class II expression in the colon was largely limited to the lower crypt region. Within the lamina propria, of all intestinal sites examined, a heterogeneous population of cells were MHC class II positive and these had morphological features of macrophages and dendritic cells. Lymphocytes, plasma cells, fibroblasts and vascular endothelium were not stained. Definition of constitutive expression of MHC class II within the canine intestine may be important in identifying upregulation of this molecule in inflammatory bowel diseases.

Animals↗

PubMed1998

Immunohistochemical characterization of the lesions of feline progressive lymphocytic cholangitis/cholangiohepatitis.

The histopathological features of liver biopsies from 20 cats with progressive lymphocytic cholangitis/cholangiohepatitis are reported. These biopsies were subject to immunohistochemical investigation for expression of CD3, CD79. Major Histocompatibility Complex (MHC) Class II molecules, and feline IgG, IgM and IgA. Livers from five normal cats, which were also examined showed constitutive expression of MHC Class II by sinusoidal Kupffer cells and bile duct epithelium, in addition to a population of portal, and bile duct inter-epithelial, CD3+ T lymphocytes. In liver biopsies from cats with the active phase of lymphocytic cholangitis/cholangiohepatitis (n = 11), the portal lymphocytes were predominantly CD3+ T cells that infiltrated bile duct epithelium and periportal hepatic parenchyma, CD79+ B lymphocytes formed distinct aggregates or follicles within the regions of T-cell infiltration. Low numbers of plasma cells were present, and these predominantly expressed IgA. MHC Class II was expressed by Kupffer cells, infiltrating T and B lymphocytes and macrophages. There was membrane and cytoplasmic Class II expression by bile duct epithelium, some vascular endothelium, and fibroblasts within areas of fibrosis. In liver biopsies from cats with chronic lymphocytic cholangitis/cholangiohepatitis (n = 9), there was less in flammation, but the composition of the infiltrates was similar to that in the active phase of disease. The findings provide further evidence for an immune mediated pathogenesis in progressive lymphocytic cholangitis/cholangiohepatitis.

Animals↗

PubMed1998

Characterization of wear debris associated with aseptic loosening of a canine hip prosthesis.

A 12-month-old Golden Retriever bitch underwent unilateral hip arthroplasty following a diagnosis of coxofemoral osteoarthritis secondary to hip dysplasia. The hip prosthesis underwent aseptic loosening and was removed 6 months after implantation. Synovial biopsies taken at that time revealed scattered foci of granulomatous inflammation associated with intra-cytoplasmic and extracellular particulate material. Electron microscopical analyses demonstrated that this material contained cobalt, chromium, titanium and zirconium, which was probably wear debris from the loosened prosthesis. In human patients with hip arthroplasty, widespread dissemination of wear debris from loosened prostheses occasionally occurs, with an increased prevalence of neoplasia. A similar phenomenon may be predicted to occur with the increasing use of hip arthroplasty in the dog.

Animals↗

PubMed1998