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.     

Molecular characterisation of the gut microflora of healthy and inflammatory bowel disease cats using fluorescence in situ hybridisation with special reference to Desulfovibrio spp

Inflammatory bowel disease (IBD) is a common cause of chronic large bowel diarrhoea in cats. Although the aetiology of IBD is unknown, an immune-mediated response to a luminal antigen is thought to be involved. As knowledge concerning the colonic microflora of cats is limited and requires further investigation, the purpose of this study was to determine the presence of specific bacterial groups in normal and IBD cats, and the potential role they play in the health of the host. Total bacterial populations, Bacteroides spp., Bifidobacterium spp., Clostridium histolyticum subgp., Lactobacillus-Enterococcus subgp. and Desulfovibrio spp. were enumerated in 34 healthy cats and 11 IBD cats using fluorescence in situ hybridisation. The study is one of the first to show the presence of Desulfovibrio in cats. Total bacteria, Bifidobacterium spp. and Bacteroides spp. counts were all significantly higher in healthy cats when compared with IBD cats, whereas Desulfovibrio spp. (producers of toxic sulphides) numbers were found to be significantly higher in colitic cats. The information obtained from this study suggests that modulation of bacterial flora by increasing bifidobacteria and decreasing Desulfovibrio spp. may be beneficial to cats with IBD. Dietary intervention may be an important aspect of their treatment.     

鸡传染性法氏囊病BK912变异株疫苗安全及效力试验

使用３批ＩＢＤ－ＢＫ９１２冻干疫苗对２０日龄在隔离器中饲养的ＳＰＦ鸡经２次点眼、口服各２０００ＴＣＩＤ５０，干二免后１４天用１００ＢＩＤ５０１０８４Ａ法氏囊囊毒攻毒，对照组１００％发病，免疫的３个组１００％保护，通过对囊指数的测定，疫苗安全，对囊无损伤。     

不同IBD疫苗对SPF鸡的免疫抑制作用

用Ａ、Ｂ、Ｃ、Ｄ４种ＩＢＤ毒性型疫苗对６日龄ＳＰＦ鸡进行免疫接种，根据免疫５ｄ后法氏囊的病理变化、囊／体比、囊指数以及免疫１２ｄ后对ＮＤ疫苗的免疫应答情况等，综合评定这４种疫苗的免疫抑制作用。结果发现，雏鸡早期免疫ＩＢＤ毒性型疫苗对法氏囊有明显的损害，其中对囊损伤最轻的是Ａ苗，最严重的是Ｂ苗。这４种ＩＢＤ疫苗均对新城疫疫苗免疫产生免疫抑制作用，其中Ａ苗引起的最轻、最短暂，Ｄ苗次之，最严重的是Ｂ苗。     

鸡传染性囊病二价活疫苗攻击保护效果的观察

使用ＳＰＦ雏鸡进行了鸡传染性囊病二价活疫苗攻击保护效果的观察。１４日龄免疫２０００ＴＣＩＤ５０剂量的二阶苗或ＢＪ８３６苗价苗。免疫后１４ｄ（２８日龄）分别用不同剂量（１：１,１：１０,１：１００）的标准Ｉ型强毒株ＣＪ８０１株或标准变异株强毒１０８４Ａ株进行攻击,攻击后５ｄ剖杀观察。二价革免疫组能抵抗极高剂量（１：１）的ＣＪ８０１株及高剂量（１：１０）的１０８４Ａ株的攻击,但不能抵抗极高剂量（１：１     

鸡传染性法氏囊病的实验研究

将１２０只白来航雏鸡随机分成４个实验组和对照组,分别于第１、２、３和４周龄感染传染性法氏囊病病毒和生理盐水。在感染后第７ｄ,外周血液中白细胞数、血糖和胰高血糖素含量明显低于对照组;在感染后第１４ｄ,上述指标虽有所升高,但仍低于同期对照组。表明ＩＢＤＶ对体内淋巴组织有明显损伤,胰高血糖素的变化及血糖的降低可能是由于胰腺实质细胞变性坏死所致。     

传染性法氏囊病Vero细胞灭活疫苗的研究

传染性法氏囊病Ｖｅｒｏ细胞灭活疫苗的免疫试验表明,用０．５和０．８ｍＬ／只剂量分别肌肉接种。１０～１４日龄首免,８ｄ后可检出病毒特异性抗体,１４ｄ抗体Ｐ／Ｎ值为３．８～５．６．病毒中和抗体滴度为１∶３２～１∶６４;２１ｄＰ／Ｎ值为６．３～６．８,中和抗体滴度平均为１∶１０２４～１∶２０４８,此时血清抗体对鸡的保护率为８５．７％．３０～３５日龄二免,１４ｄ后Ｐ／Ｎ值５．０～５．２,中和抗体滴度高达１∶２０４８～１∶８１９２,对鸡的保护率为１００％．二免后１１２ｄ（１４７日龄）抗体仍保持较高水平,Ｐ／Ｎ值为３．２～３．４．野外试验表明,这种疫苗安全、有效。在３０００只蛋鸡群平行试验,灭活苗比活苗抗体水平高出０．２个光密度值,抗体持续期长。接种灭活苗的鸡群５个月内未发生此病。     

复方中药合剂对肉仔鸡疫苗免疫抗体效价的影响

为探讨自拟复方中药合剂对疫苗免疫后抗体效价的影响。以AA肉仔鸡为研究对象,重点考察复方中药合剂分别与新城疫(ND)Clone-30疫苗、ND油乳剂灭活苗和传染性法氏囊病(IBD)冻干苗联用后,肉仔鸡血清中ND、IBD抗体效价的变化规律。结果显示,试验组鸡血清中的ND和IBD抗体效价均高于对照组。说明,该复方中药合剂可增强肉仔鸡的疫苗免疫效果,具有显著的免疫增强作用。