Mast cells and IgE-bearing cells in lungs of RAO-affected horses

Recurrent airway obstruction (RAO) is a common condition in stabled horses characterised by small airway inflammation and obstruction following exposure of susceptible horses to mouldy hay and straw. The aim of the present study was to investigate whether lung tissue from horses with RAO contains higher numbers of IgE-protein positive (+) cells and mast cells compared to controls after mouldy hay challenge. Furthermore, mast cell subtypes in lung tissue were investigated. IgE+ cells were detected in most lung tissue samples but no significant differences between RAO-affected and control horses were found. In the wall of the bronchi and bronchioli of both RAO-affected and control horses, mainly chymase+ mast cells (MC(C)) were present (85% in the bronchial wall and 77% in the wall of the bronchioli), while 73% of the mast cells (MC) around blood vessels were tryptase+ mast cells (MC(T)). No double stained MCs were detected. RAO-affected horses had significantly more MC(C) than controls in the wall of the bronchi (median=7.6 and 1.7 cell/mm(2), respectively, P< or =0.05). They also showed a tendency for more MC(C) in the wall of the bronchioli than controls (median=21 and 2.9 cells/mm(2), respectively, P=0.07) but there were no differences in MC(T) numbers. The data suggest an involvement of MC(C) in the pathogenesis of RAO. Independently of the clinical diagnosis, there was a significant relationship between high MC(C) numbers in the bronchial wall and lung fibrosis, suggesting that these MC(C) may be involved in tissue remodelling. Furthermore, high MC(C) numbers were also associated with increased infiltration with lymphocytes and neutrophils.     

Characterization of mast cell numbers and subtypes in biopsies from the gastrointestinal tract of dogs with lymphocytic-plasmacytic or eosinophilic gastroenterocolitis

It has been suggested but not proven that hypersensitivity type I reactions are involved in the pathogenesis of canine inflammatory bowel disease (IBD). The main effector cells in type I hypersensitivity reactions are mast cells (MCs). Canine MCs, as human MCs, can be subdivided into three subtypes according to their content of mast cell-specific proteases: tryptase (MC_T), chymase (MC_C), or tryptase and chymase bearing MCs (MC_TC). In this study, numbers and subsets of mast cells were investigated in biopsies from the gastrointestinal tract of dogs with histopathologically confirmed lymphocytic-plasmacytic enteritis (LPE) (n = 4), lymphocytic-plasmacytic colitis (LPC) (n = 1) and eosinophilic gastroenterocolitis (EGE) (n = 11). Paraffin sections of formalin-fixed samples from the stomach, small intestine (duodenum, jejunum, ileum) and colon were stained by using a metachromatic staining method (kresylecht-violet; KEV) and a combined enzyme histochemical and immunohistochemical technique for chymase and tryptase. Additionally, immunohistochemistry with antibodies against T cells (CD3), macrophages (myeloid/histiocyte antigen) and IgA, IgG and IgM bearing cells was conducted. Quantitative evaluation of mast cells and semiquantitative scoring of immunohistochemically stained cells were performed. Between the two histopathologically defined groups clear differences concerning mast cell numbers were detected. In most affected intestinal tissue locations of dogs with LPE/LPC a decrease in metachromatically (kresylecht-violet) stained granule-containing MCs and immunohistochemically stained MC_T,C,TC was found. This reduction could be due to mast cell degranulation, a T helper cell 1 dominated reaction pattern or a “thinning out” due to increasing T cells, IgA and IgG bearing cells. Dogs with EGE displayed higher variability in mast cell numbers but most of the affected large and small intestinal locations had increased numbers of MCs. In these cases, T cells, IgA bearing cells and macrophages also increased. Increased numbers of MCs and eosinophils seen in the intestinal mucosa of dogs with EGE could indicate the presence of a type I hypersensitivity reaction (T helper cell 2 pattern) in response to dietary antigens. Changes in cell numbers occurred also in unaffected locations of dogs with LPE/LPC and EGE which showed reduced MC_T,C,TC, increased KEV positive cells and partially increased leucocytes and macrophages.     

Phylogenetic characterisation of naturally occurring feline immunodeficiency virus in the United Kingdom

Feline immunodeficiency virus (FIV) is a significant pathogen of domestic and non-domestic felids worldwide. In domestic cats, FIV is classified into five distinct subtypes (A-E) with subtypes A and B distributed most widely. However, little is known about the degree of intrasubtype viral diversity and this may prove critical in determining whether monovalent vaccines are likely to protect against FIV strains within a single subtype. Here, we characterise novel env sequences from 47 FIV strains recovered from infected cats in the United Kingdom and its environs. Phylogenetic analyses revealed that all bar one sequence belonged to subtype A, the predominant subtype in Western Europe. A single sequence was identified as a likely subtype A/C recombinant, intriguing given that subtype C does not appear to exist in either the UK or North Western Europe and suggestive of a recombination event predating its introduction into the UK. Subtype A strains from the UK were not significantly differentiated from representative subtype A isolates found elsewhere suggesting multiple introductions of FIV into the country. Divergence among isolates was comparable to that observed for subtype A isolates worldwide, indicating that FIV in the UK covers the full spectrum of subtype A diversity seen globally. This study demonstrates that while subtype A is predominant in the UK, novel introductions may result in the emergence of novel subtypes or intersubtype recombinants, potentially circumventing vaccine strategies. However, the dominance of subtype A suggests that the development of a regional or subtype-specific protective vaccine for the UK could be achievable.     

Distribution of mast cell subtypes and immune cell populations in canine intestines: evidence for age-related decline in T cells and macrophages and increase of IgA-positive plasma cells

The distribution and numbers of leucocytes and mast cells (MC) in the canine gastrointestinal tract of three different age groups was investigated immunhistochemically. In all age groups, CD3+ T cells were more prominent in the villus region than in the crypt areas without differences between intestinal segments, whereas macrophages were more randomly distributed. Kresylecht-violet and tryptase-positive MC were prominent in pericrypt regions with statistic significances. Chymase-bearing mast cells, IgA-, IgG- and IgM-containing cells did not show significant differences in their distribution but, except for IgG-positive cells, subjective trends with increasing numbers towards the crypts exist. The reasons for the distribution of T cells, macrophages, immunoglobulin-containing cells and mast cells are not clear. Lamina propria CD3+ T cells and macrophages significantly decreased whilst a significant increase of IgA-containing plasma cells with increasing age was found. For mast cell subtypes, IgG- and IgM-containing cells no significant changes in numbers with increasing age exist.     

Flea bite hypersensitivity: new aspects on the involvement of mast cells

A study was performed to test the effect of sensitization to flea antigen, followed by exposure to fleas on mast cells (MCs), their subtypes, and IgE+ cells. Biopsies were taken from flea-sensitized dogs (n=28) and non-sensitized dogs (n=5) that had been exposed to fleas. Control groups consisted of flea-sensitized (n=12) and non-sensitized dogs (n=9) that were not exposed to fleas. Biopsies, taken before, 24 and 72 h after local flea exposure, were stained with haematoxylin and eosin (H&E), toluidine blue, a double labelling technique for MC chymase and tryptase and anti-IgE. An intradermal test for flea antigen was performed and serum titres of allergen-specific IgE and IgG were measured. Significantly higher numbers (P<0.001) of double labelled MCs compared to toluidine blue stained MCs were detectable in flea-sensitized dogs independent of flea exposure. In contrast, in non-sensitized dogs, the number of toluidine blue stained MCs and the number of double labelled MCs did not differ. In flea-sensitized dogs after flea exposure the percentage of C-MC was significantly increased at day 1 (P<0.001) and day 3 (P<0.001), whereas the percentage of TC-MCs decreased significantly at day 1 (P<0.001) and day 3 (P<0.05). The percentage of T-MCs decreased (P<0.05 day 0 versus day 1; P<0.05 day 0 versus day 3). No significant difference was detectable after toluidine blue staining and staining for IgE+ cells between the groups nor between the MC density and the number of IgE+ cells. All flea-sensitized dogs had positive skin tests to flea antigen and high serum titres of flea-specific serum IgE and IgG antibodies. In non-sensitized dogs, these results were negative. Our data provide strong evidence for an upregulation of MC proteases during the process of sensitization and a generalized selective release of mast cell tryptase after exposure to the antigen.     

2016-2017年江西地区猪繁殖与呼吸综合征病毒分子流行病学调查及ORF5基因变异分析

为了解近年来江西地区猪繁殖与呼吸综合征病毒（porcine reproductive and respiratory syndrome virus,PRRSV）分子流行病学和其遗传变异情况,本次调查于2016-2017年从江西省各地区规模化猪场采集453份疑似猪繁殖与呼吸综合征（PRRS）的病料,采用RT-PCR方法对所有病料进行检测。结果发现,其中321份病料为PRRSV阳性,阳性率为70.86%,各地区的阳性率在19.15%~84.85%之间。挑选14份阳性样品测序后,经ORF5基因序列分析,江西地区各PRRSV毒株ORF5基因的核苷酸同源性为83%~100%,PRRSV流行毒株与参考毒株的同源性在59.9%~98.5%之间。基于ORF5基因的进化树分析表明,14个测序毒株均为美洲型毒株,其中有4株为基因亚型Ⅰ,即高致病性毒株（HP-PRRSV）;3株为基因亚型Ⅱ,即经典毒株;3株为基因亚型Ⅲ,即NADC30-like毒株;4株为新出现的基因亚型Ⅳ。氨基酸序列比对分析表明,基因亚型Ⅰ、Ⅱ、Ⅲ和Ⅳ毒株ORF5基因编码的GP5蛋白氨基酸在3个表位及2个重要的抗原相关区域存在较大变异,其中以NADC30毒株为代表的基因亚型Ⅲ毒株和以GD1404毒株为代表的基因亚型Ⅳ毒株均表现出独有的氨基酸变异,这些变异可能会影响GP5蛋白的免疫原性。本次调查结果表明,2016-2017年江西地区PRRSV流行出现了新形势,美洲型毒株出现了多基因亚型共同存在的局面,以高致病性毒株（HP-PRRSV）为主,NADC30-like毒株和新基因亚型等新毒株的比例较高,同时还存在经典毒株;持续实时监测PRRSV的毒株流行和变异情况,可为临床诊断、药物和疫苗开发及PRRS的科学防控提供依据。     

Histopathological and enzyme histochemical observations on mast cells in pulmonary arterial lesion of dogs with Dirofilaria immitis infestation

Histopathological and enzyme histochemical observations were performed on mast cells in pulmonary arterial lesion of Dirofilaria immitis in dogs. The results showed that chymase- and tryptase-positive mast cells were diffusely present in the lesions, especially in the adventitia and proliferated intima. At 2 weeks after surgical worm transplantation, mast cells already appeared in the intima and media, and chymase-positive cells were dominant in the adventitia. Results of this study suggested a possibility that mast cells would be involved in the pathogenesis of pulmonary arterial lesion of dogs with Dirofilaria immitis infestation.     

One‐year conditional survival of dogs and cats with invasive mammary carcinomas: A concept inspired from human breast cancer

Numerous studies have described the prognostic factors of canine and feline mammary carcinomas (MCs), that is, variables that predict patient survival after diagnosis. But how does survival estimation evolve in patients that escaped early death from their cancer? In human oncology, conditional survival (CS), the probability of surviving X further years when cancer patients have already survived Y years, is used to analyse cancer outcomes in a long‐term perspective. In this cohort of 344 dogs and 342 cats with surgically removed stage I to III invasive MCs, with a minimal follow‐up of 2 years, we calculated the 1‐year CS, that is, the probability for patients that have survived 1 year, to survive or to die from cancer during the subsequent year. The 1‐year conditional specific survival probabilities were 59% and 48% at diagnosis of invasive MC respectively in dogs and cats, and 80% and 52% in 1‐year surviving dogs and cats respectively, suggesting that 1‐year surviving dogs were relatively protected from cancer‐related death, whereas feline MCs remained life‐threatening cancers for longer periods of time. Among the most significant parameters associated with CS in surviving dogs and cats were the nodal stage and lymphovascular invasion, as well as patient age, cancer stage and margin status in surviving dogs. By comparison, tumour size and the histological grade did not significantly alter CS probabilities in surviving dogs and cats. Conditional survival may be considered a very interesting tool for veterinary practitioners to estimate the likely outcome of cancer survivors.     

Feline large granular lymphocyte lymphoma: An Italian Society of Veterinary Oncology (SIONCOV) retrospective study

Feline large granular lymphocyte (LGL) lymphoma is an uncommon subtype of lymphoma characterized by a grave prognosis and scarce response to chemotherapy. There are limited reports on clinico‐pathological and prognostic factors. One‐hundred and 9 cats with newly diagnosed LGL lymphoma that underwent initial staging (including hematology, serum biochemistry, thoracic radiographs and abdominal ultrasound), and followed‐up were retrospectively evaluated. LGL lymphoma was localized within the gastrointestinal tract with or without extra‐intestinal involvement in 91.7% of the cases, and at extra‐gastrointestinal sites in 8.3%. Symptoms were frequent. Anemia (31.2%) and neutrophilia (26.6%) were commonly observed, and 14 (12.8%) cats had neoplastic circulating cells. Frequent biochemistry abnormalities included elevated ALT (39.4%) and hypoalbuminemia (28.4%). Twenty (54.1%) of 37 cats had elevated serum LDH. Treatment varied among cats, and included surgery (11%), chemotherapy (23%), corticosteroids (38.5%) and no treatment (27.5%). Median time to progression (MTTP) was 5 days, and median survival time (MST) 21 days. MST was significantly shorter in the case of substage b, circulating neoplastic cells, lack of chemotherapy administration, and lack of treatment response. A small subset of cats (7.3%) survived more than 6 months, suggesting that a more favorable clinical course can be found among LGL lymphoma patients.     

Molecular subtyping of feline immunodeficiency virus from cats in Melbourne

OBJECTIVE: To determine the subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population in Melbourne. METHODS: Blood samples were collected from 42 cats that had serum antibodies against FIV. DNA was extracted and subjected to polymerase chain reaction (PCR) to amplify variable regions of the envelope (env) and group specific antigen (gag) genes of FIV. PCR products were directly sequenced or sequenced after cloning when direct sequencing yielded ambiguous results. Phylogenetic analysis was performed and comparisons made with representative sequences of different subtypes. RESULTS: The variable region of the env gene was successfully amplified by PCR from 41 of the 42 cats. All 41 were found to cluster with subtype A env sequences. The variable region of the gag gene was successfully amplified by PCR from all 42 cats. Forty-one were found to cluster with subtype A gag genes and one was found to cluster with subtype B sequences, suggesting that it may be derived from a recombinant env A/gag B virus. CONCLUSIONS: Subtype A is the predominant FIV type in Melbourne, although a subtype A/B recombinant was identified in the population of FIV positive cats. These results of env gene analysis were similar to those in a previous Australian study, suggesting that subtype A predominates in Australia. The results of the gag gene analysis show the importance of analysing multiple areas of the FIV genome when assigning FIV subtypes. Comparison with other major urban centres may provide useful information about the phylogenic diversity of FIV in Australia.     

Effects of ibrutinib on proliferation and histamine release in canine neoplastic mast cells

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib is effective in the treatment of human chronic lymphocytic leukaemia and mantle cell lymphoma. Recent data have shown that ibrutinib also blocks IgE‐dependent activation and histamine release in human basophils (BAs) and mast cells (MCs). The aim of this study was to investigate whether BTK serves as a novel therapeutic target in canine mast cell tumours (MCTs). We evaluated the effects of ibrutinib on two canine MC lines, C2 and NI‐1 and on primary MCs obtained from canine MCTs (n = 3). Using flow cytometry, we found that ibrutinib suppresses phosphorylation of BTK and of downstream STAT5 in both MC lines. In addition, ibrutinib decreased proliferation of neoplastic MCs, with IC₅₀ values ranging between 0.1 and 1 μM in primary MCT cells and between 1 and 3 μM in C2 and NI‐1 cells. In C2 cells, the combination “ibrutinib + midostaurin” produced synergistic growth‐inhibitory effects. At higher concentrations, ibrutinib also induced apoptosis in both MC lines. Finally, ibrutinib was found to suppress IgE‐dependent histamine release in primary MCT cells, with IC₅₀ values ranging from 0.05 to 0.1 μM in NI‐1 cells, and from 0.05 to 1 μM in primary MCT cells. In summary, ibrutinib exerts anti‐proliferative effects in canine neoplastic MCs and counteracts IgE‐dependent histamine release in these cells. Based on our data, ibrutinib may be considered as a novel therapeutic agent for the treatment of canine MCT. The value of BTK inhibition in canine MCT patients remains to be elucidated in clinical trials.     

Adjuvanted rush immunotherapy using CpG oligodeoxynucleotides in experimental feline allergic asthma

Allergic asthma is driven by relative overexpression of Th2 cell-derived cytokines in response to aeroallergens. In independent studies, both allergen-specific rush immunotherapy (RIT) and CpG oligodeoxynucleotides (ODN) showed promise in blunting eosinophilic inflammation in a model of feline allergic asthma. We hypothesized that RIT using allergen and CpG ODN would work synergistically to dampen the asthmatic phenotype in experimentally asthmatic cats. Twelve cats with asthma induced using Bermuda grass allergen (BGA) were studied. Of these, six were administered adjuvanted BGA RIT using CpG ODN #2142; six were administered placebo (saline) RIT and later crossed over to adjuvanted RIT. Over 2 days, subcutaneous CpG ODN (0.5ng/kg) with BGA (increasing doses every 2h from 20 to 200microg) was administered. Adverse events were recorded and compared with historical controls. Percentage of eosinophils in bronchoalveolar lavage fluid (BALF), % peripheral CD4+CD25+ T regulatory cells (Tregs), lymphocyte proliferation in response to ConA, and cytokine concentrations in BALF were measured over 2 months. Group mean BALF % eosinophils for the adjuvanted RIT cats were significantly lower at week 1 and month 1 (p=0.03 for both), and marginally significantly lower at month 2 (p=0.09) compared with placebo RIT cats. By the end of the study, 8/12 treated cats had BALF % eosinophils within the reference range for healthy cats. Adjuvanted RIT, but not placebo RIT, cats had significant decreases in the ConA stimulation index over time (p=0.05). BALF IL-4 concentrations were significantly higher at week 1 in adjuvanted RIT cats compared with baseline and month 2, and also with placebo RIT cats at week 1. No significant differences were detected between treatments or over time for IL-10 or IFN-gamma concentrations in BALF or for %Tregs cells in peripheral blood. Adjuvanted RIT using CpG ODN in experimental feline asthma dampens eosinophilic airway inflammation. Adverse effects associated with adjuvanted RIT were less severe compared with a historical, non-adjuvanted RIT protocol. The exact mechanism(s) by which adjuvanted RIT alters the aberrant allergic immune response were not elucidated in this study.     

The morphology and behavior of feline cutaneous mastocytomas

Correlation of histopathology with the behavior of cutaneous mastocytomas in 85 cats revealed two distinct histologic subtypes which were predictive of biologic behavior. The first subtype comprised 65 cats of various breeds which had solitary, discrete, dermal tumors composed of slightly atypical mast cells. Most tumors in this group were histologically and behaviorally benign. However, seven solitary tumors with marked anisocytosis and mitotic activity recurred or spread to other sites within 2 to 3 months. The second subtype occurred in 18 cats which had discrete subcutaneous nodules composed primarily of histiocyte-like cells with equivocal cytoplasmic granularity after staining with toluidine blue. They were identified as mast cells by electron microscopy. Seventeen of the 18 affected cats were Siamese. The histiocytic mastocytomas occurred predominantly in young cats (less than 4 years) and were usually multiple. In the four cats of this group for which we have prolonged follow-up data, the tumors underwent apparently spontaneous regression within 2 years of initial tumor detection. Two other cats had tumors which contained mixtures of mast cell and histiocytic morphologies.     

B亚型禽偏肺病毒的分离鉴定及致病性研究

旨在确定我国部分养鸡场的鸡出现甩头、精神萎靡和肿头综合征是否由禽偏肺病毒（aMPV）引起,本研究从山东、福建、黑龙江等地的发病蛋鸡和肉鸡场采集鼻甲骨、气管和肺等样品,首先利用aMPV特异性的RT-PCR方法对临床样品进行初步检测,将RT-PCR检测阳性样品接种Vero细胞进行病毒分离,然后利用G/F基因序列分析及间接免疫荧光试验（IFA）等鉴定病毒的亚型,最后将分离株感染SPF鸡进行致病性分析。结果显示：在采集的220份样品中,RT-PCR检测结果显示,有3份鼻甲骨样品在228 bp左右出现特异性条带,将阳性病料接种Vero细胞盲传5代后,细胞出现变圆、聚集和融合等aMPV特征性细胞病变（CPE）,表明成功分离到3株aMPV,将其分别命名为SD2001、SD2002和HLJ2101。G和F基因同源性分析显示,来自蛋鸡的SD2001、SD2002和来自肉鸡的HLJ2101分离株的G和F基因与其他B亚型aMPV毒株的核苷酸和氨基酸序列相似性均较高,核苷酸的相似性分别为93.4%～98.6%和95.6%～100.0%,氨基酸的相似性分别为88.7%～97.8%和97.6%～100.0%;而与A、C和D亚型的G和F基因同源性较低,核苷酸的相似性分别为27.1%～61.8%和66.8%～74.8%,氨基酸的相似性分别为16.1%～36.7%和72.5%～86.5%,这些结果表明,SD2001、SD2002和HLJ2101分离株属于B亚型aMPV。进一步利用B亚型aMPV特异性的阳性血清进行IFA检测,接种SD2001、SD2002和HLJ2101的Vero细胞均可以观察到特异性的绿色荧光信号,进一步证实3个分离株属于B亚型aMPV。选择SD2001感染3周龄SPF鸡进行了致病性研究,结果发现SPF鸡感染后3～6 d出现精神萎靡、甩头和流鼻涕等症状,鼻甲骨、气管和肺也出现病理性损伤,其发病率为90%（18/20）。3株B亚型aMPV的分离不仅有助于明确我国部分养鸡场出现肿头综合征的发病原因,同时也证实B亚型aMPV流行毒株对鸡有明显的致病性,这些结果为我国家禽疫病的诊断和有效防控提供了重要理论依据。     

The use of oral cyclosporin to treat feline dermatoses: a retrospective analysis of 23 cases

Limited information is available regarding the use of cyclosporin A (CsA) for the treatment of feline dermatoses. The aim of this retrospective study was therefore to describe the efficacy of CsA for the therapy of eosinophilic granuloma (EG), eosinophilic plaque, indolent ulcer, linear granulomas, idiopathic pruritus and stomatitis. A computer search for feline dermatological cases treated with CsA between 1999 and 2004 was performed. Based on history, clinical signs and laboratory diagnostic tests, it was then possible to divide cases into three groups and to select 23 cats. Seven cats had one or more of the following conditions: EG, eosinophilic plaque, indolent ulcer and/or linear granuloma (group A); eight cats had idiopathic pruritus (group B) and eight cats had plasmacytic stomatitis (group C). Doses ranged from 5.8 to 13.3 mg kg(-1) oral CsA. All cats were monitored, with complete serum blood analysis and physical examination, monthly for a minimum of 6 months. Response to therapy was scored (severity of lesions and pruritus) with a 0-10 visual analogue scale at each visit (day 0, day, 30, day 60, day 90). All cats in groups A and B were cured and were maintained on alternate day therapy. In group C, 4/8 patients went into remission, while remaining cats have a fair to good improvement. Routine haematological and biochemical examination failed to reveal abnormalities related to CsA administration.     

Flow cytometric analysis of T-lymphocyte subsets in cats.

We report a rapid, reliable method for the immunophenotype analysis of feline lymphocytes. Fluorescein isothiocyanate (FITC) conjugated to murine monoclonal antibodies f43, Fel 7 and fCD8 was used to identify phenotypes corresponding to feline T-cells, CD4+ T cells and CD8+ T cells. For isolation of white blood cells, whole blood lysis was faster, less variable and required much less sample than density gradient separation. To identify feline CD4+ and CD8+ cells simultaneously, directly conjugated FITC-fCD8 and phycoerythrin (PE) fCD4 (Fel 7) were used in two-color analysis. The two T cell sub-populations were non-overlapping. Dual-label and single-label values were not significantly different. Mean lymphocyte subset percentages in conventional and specific-pathogen-free (SPF) cats did not differ significantly. These values were: pan T lymphocytes (f43), 54.8%, CD4+ cells (Fel 7), 33.9%, and CD8+ cells (fCD8), 19.1%. Mean CD4/CD8 ratio was 1.9 in normal cats; the range was 1.2-2.6.     

Papular eosinophilic/mastocytic dermatitis (feline urticaria pigmentosa) in Devon Rex cats: A distinct disease entity or a histopathological reaction pattern?

A maculopapular eruption with clinical and histological features similar to those previously described in Sphinx cats under the name of urticaria pigmentosa is reported in five unrelated Devon Rex cats. Physical examination revealed erythematous, occasionally crusted papules, with a bilaterally symmetrical linear distribution on the latero-ventral trunk in two cases and a diffuse distribution on the ventral thorax in the other three cats. One cat also had a greasy seborrhoea on the head and dorsum. Pruritus and pigmented macules were present only in cats affected by secondary bacterial infection. Histological examination of papules in all cats and of the lesional skin of the cat affected by greasy seborrhoea revealed the presence of a perivascular to diffuse mastocytic and eosinophilic infiltrate in the dermis. The mean numbers of nondegranulated and degranulated mast cells per mm(2) were 303.2 and 451.6, respectively. The condition waxed and waned in all cats, and exacerbations were controlled with prednisolone or essential fatty acids.     

Phylogenetic analysis to define feline immunodeficiency virus subtypes in 31 domestic cats in South Africa

Feline immunodeficiency virus (FIV), a lentivirus, is an important pathogen of domestic cats around the world and has many similarities to human immunodeficiency virus (HIV). A characteristic of these lentiviruses is their extensive genetic diversity, which has been an obstacle in the development of successful vaccines. Of the FIV genes, the envelope gene is the most variable and sequence differences in a portion of this gene have been used to define 5 FIV subtypes (A, B, C, D and E). In this study, the proviral DNA sequence of the V3-V5 region of the envelope gene was determined in blood samples from 31 FIV positive cats from 4 different regions of South Africa. Phylogenetic analysis demonstrated the presence of both subtypes A and C, with subtype A predominating. These findings contribute to the understanding of the genetic diversity of FIV.     

Analysis of 8 Sarcomeric Candidate Genes for Feline Hypertrophic Cardiomyopathy Mutations in Cats with Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. Causative mutations have been identified in the Maine Coon (MC) and Ragdoll breed in the cardiac myosin binding protein C gene (MYBPC3). HCM is thought to be inherited in other breeds.
Hypothesis: That a causative mutation for HCM in the British Shorthair (BSH), Norwegian Forest (NWF), Siberian, Sphynx, or MC cats would be identified in the exonic and splice site regions of 1 of 8 genes associated with human familial HCM.
Animals: Three affected BSH, NWF, Siberians, Sphynx, 2 MC (without the known MC mutation), and 2 Domestic Shorthair cats (controls) were studied.
Methods: Prospective, observational study. Exonic and splice site regions of the genes encoding the proteins cardiac troponin I, troponin T, MYBPC3, cardiac essential myosin light chain, cardiac regulatory myosin light chain, α tropomyosin, actin, and β–myosin heavy chain were sequenced. Sequences were compared for nucleotide changes between affected cats, the published DNA sequences, and control cats. Changes were considered to be causative for HCM if they involved a conserved amino acid and changed the amino acid to a different polarity, acid-base status, or structure.
Results: A causative mutation for HCM was not identified, although several single nucleotide polymorphisms were detected.
Conclusions and Clinical Importance: Mutations within these cardiac genes do not appear to be the only cause of HCM in these breeds. Evaluation of additional cardiac genes is warranted to identify additional molecular causes of this feline cardiac disease.     

Pathological and immunohistochemical features of 45 cases of feline meningioma

Meningioma is the most common primary brain tumor in cats, although there are few reports about their pathological features. To investigate the histopathological subtypes and immunohistochemical features including expression of cytokeratin and cell adhesion molecules, 45 cases of feline meningioma were examined. The mean age was 12.5 years (range 6–21 years). No statistically significant sex predilection was observed. Regarding the anatomical location of meningioma, tumors mostly developed in the cerebrum, followed by spinal cord and cerebellum, and multiple meningioma was observed in one cat. Microscopically, linear or focal mineralization was observed in 40 cases and cholesterol cleft was observed in 14 cases. Based on histopathological subtypes, there were 15 fibrous, 22 transitional, 2 meningothelial, 5 atypical, and 1 anaplastic meningiomas. These subtypes are classified into grade 1 (39 cases), grade 2 (5 cases), and grade 3 (1 case). There was no significant difference in the Ki-67 index among histological subtypes or grades. Immunohistochemically, the tumor cells were positive for cytokeratin in 5 cases (12.8%), vimentin in 17 cases (43.6%), E-cadherin in 36 cases (92.3%), β-catenin in 21 cases (53.8%), and N-cadherin in 1 case (2.6%), demonstrating the utility of E-cadherin-immunohistochemistry for the diagnosis of feline meningiomas.