Genotype characterisation of Giardia duodenalis isolates from domestic and farm animals by SSU-rRNA gene sequencing

In order to investigate the genotypes of Giardia duodenalis from domestic and farm animals in Italy, 21 Giardia isolates, 17 from dogs, 1 from cat and 3 from dairy calves, were genetically characterised by SSU-rRNA gene sequencing. Among dogs, 76.5% of isolates showed the dog-specific genotypes (Assemblages C, D and C/D mixed Assemblage) and 23.5% exhibit potential zoonotic genotypes (Assemblage A and A/C mixed Assemblages). The cat isolate belonged to assemblage A, whereas the sequences among the isolates from calves were found to correspond to hoofed-livestock genotype, namely Assemblage E. These findings suggest that infection of humans by zoonotic genotypes from domestic animals could be of low epidemiological significance, although possible. The present study represents the first contribute to the knowledge of G. duodenalis genotypes in domestic and farm animals from Italy.     

Swelling of a fibre reinforced composite in which the matrix is water reactive

Summary The swelling behaviour of an elastic fibre reinforced composite consisting of an inert fibrous phase embedded in a water reactive matrix is described. It is supposed that the addition of water causes the matrix to swell and become more compliant while the fibres passively resist the swelling stresses exerted by the matrix. A concise relation for the shrinkage or swelling strain is derived in terms of moisture content, the volume proportions of the phases, the overall elastic constants of the composite, the elastic constants of the matrix, and the moisture content at which the reinforcing elements are stress free.     

Theory of X-ray measurement of microfibril angle in wood

Summary A diffraction intensity function for material bodies composed of arrays of crystalline fibres such as occurs with the cellulose of wood has been derived. It is implied in the analysis that the crystalline fibres making up the body have fibre symmetry- that there is a tendency for groups of fibres to have one set of crystal axes parallel while in the orthogonal direction the axes assume a low degree of order. It is further assumed that the patterns of the angular arrangement of the fibre groups relative to one axis of the body is independent of the direction about that axis. These conditions are believed to be compatible with the cellulosic structure found in wood. Thus it becomes possible to calculate the expected diffraction intensity profiles of realistic (and therefore complex) models of wood. This has aided the interpretation of the reflections from the (040) crystal planes of cellulose which are contaminated by low level reflections from other crystal planes, and it has been found that it might be possible by conjoint analysis of the paratropic (002) reflections and the diatropic (040) reflections to measure the complete cell wall planar microfibril angle distribution and the shape of the cell wall cross-section.This work is supported by the New Zealand Foundation for Research Science and Technology under contract # UOC 401     

Correlation between radiographie and arthroscopic findings in the equine carpus

The radiographic and arthroscopic findings in 150 carpal joints in 114 lame horses were compared. Chip, slab, or sagittal fractures were identified in 130 (87%) joints. In 101 (78%) of these there was good agreement between radiographic and arthroscopic findings on the number and position of fractures. In 23 (18%) joints, chip fractures additional to those seen radiographically were found arthroscopically. In one joint a large chip fracture from the craniolateral aspect of the distal radius was identified only by arthroscopy, while in 6 joints fractures were identified only by radiography. Observed causes of lameness, other than intra-articular fractures, included degenerative joint disease, synovitis, ruptured intra-carpal ligaments, and haemarthrosis. Correlation between the radiographic and arthroscopic assessment of degenerative joint disease was poor. It was concluded that both radiography and arthroscopy should be used to obtain the most accurate assessment of the equine carpus.     

Myofibroblastic fibrosarcoma with multifocal osseous metaplasia at the site of equine influenza vaccination

We describe a fibrosarcoma in a 12-year-old Quarterhorse × Arabian gelding as a sequela to equine influenza vaccination. Shortly after the second vaccination, swelling at the site was noticed by the owner and it continued to increase in size over the following 6 months. Biopsy of the mass indicated a fibrosarcoma had developed at the vaccination site. It was approximately 20 cm in diameter and elevated well above the level of the skin. There was no clinical evidence of metastases to the lungs or local lymph nodes. Surgical resection of the mass was performed and the wound healed by first and second intention. Histopathological examination and immunohistochemical staining confirmed a myofibroblastic fibrosarcoma with multifocal osseous metaplasia. To the authors' knowledge, this is the first equine case of a vaccine-associated fibrosarcoma.     

Chronic inflammatory disorders of the gastrointestinal tract of companion animals

In the inflammatory bowel diseases (IBD) that affect dogs and cats there appears to be dysregulation of normal mucosal immunity, characterised by polyclonal lymphocytic infiltrates which are presumably specific for luminal antigens. There is an absence of a classical polarisation of either T-helper (Th) 1 or Th2 cytokine responses, although increased expression of mRNA for interleukin (IL) 2 and IL-12p40 and a shift towards mucosal immunoglobulin (Ig) G production are consistent findings, whilst variable responses are seen in tumour necrosis factor-α (TNF-α), IL-1, IL-4, IL-6, and interferon-γ (IFN-γ). Increased mucosal permeability and deranged intestinal motility are common sequelae.

Despite obvious similarities with Crohn’s disease and ulcera- tive colitis in humans, important differences exist. Of these, the diffuse superficial nature but with no Th1 or Th2 bias, and the prevalence of proximal small intestinal disease are notable. Potential hypotheses for these disparities include specific differences in the types or locations of “agonistic” gut flora, diffuse abnormalities in microbial-host interactions, a greater importance of diet, or anatomical or cellular differences in mucosal immune responses.

Although specific pathogens and genetic susceptibilities may be involved, quantitative or qualitative changes in the normal flora or abnormal responses to a normal flora are more likely to be involved in the immunopathogenesis. Dietary influences include a large source of antigen, promotion of abnormal microbial growth through Maillard compounds within canned diets, and specific macro- and micronutrient deficiencies. Although dependent on a histopathological diagnosis, limitations of biopsies procured endoscopically, lack of histopathological standardisation and difficulty distinguishing inflammation from neoplasia remain significant problems. Clinician-pathologist dialogue, immunohistochemistry, cytokine profiling and lymphocyte-clonality assessment may lead to more accurate diagnoses, a deeper understanding of the immunopathogenesis, and ultimately to new therapies or prevention of disease induction.     

Evaluation of the immunogenicity of dietary proteins in cats and the influence of the canning process

OBJECTIVE: To characterize the antigen-specific immune response to dietary proteins in cats and evaluate whether there was a qualitative or quantitative difference between the responses to dietary proteins when those proteins were fed unprocessed or as part of a canned diet. ANIMALS: 14 healthy domestic shorthair cats. PROCEDURE: Cats were fed 2 dietary proteins (soy and casein) either as unprocessed aqueous suspensions or as part of canned diets for 21 days. Serum IgG and IgA and salivary IgA were assayed by indirect ELISA, and antigen-specific proliferation of mesenteric lymph node-derived lymphocytes was determined. RESULTS: Robust serum IgG and IgA responses to dietary proteins were elicited, irrespective of the form in which they were fed. Salivary IgA responses to unprocessed proteins were not detected. However, a significant salivary IgA response to the protein isolated from the canned casein diet was observed in cats fed canned casein but not in those fed unprocessed casein. Lymphocyte proliferation to the antigens was slight, and there were no significant differences between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that cats develop robust serum IgG and IgA responses to dietary proteins when fed as either aqueous suspensions or as part of canned diets. For certain proteins, there may be an increase and a qualitative difference in the immunogenicity of canned diets, compared with unprocessed proteins. Canned diets may not be ideal for management of cats with enteritis.     

Meningitis in a dog caused by Prevotella oralis

Prevotella oralis, an obligate Gram-negative anaerobe, was shown to be the cause of meningitis in a two-year-old crossbreed dog. The dog had a six-week history of lethargy and neck pain. On presentation, the animal was reluctant to walk, had a stiff gait and neck pain on flexion. Analysis of cerebrospinal fluid documented a neutrophilic pleocytosis (7488 cells/microl) and the presence of occasional intracellular bacterial coccobacilli. The aetiological diagnosis was confirmed by routine aerobic and anaerobic culture, and identification of the isolates. This report also reviews the literature of the documented cases of bacterial meningitis in dogs.