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1.
The objective of the study reported here was to characterise the microscopic appearance of peptic-injured equine gastric squamous epithelium in relation to the duration of peptic injury. Erosions and ulcers were induced in equine gastric squamous epithelium using a feed deprivation protocol that results in prolonged increased gastric acidity. Specimens of normal gastric mucosa and mucosa with lesions created after 48 and 96 h of feed deprivation were compared for characteristics associated with angiogenesis and mucosal proliferation. Fifteen mature horses, 9 geldings and 6 mares, age 3-20 years, were divided into 3 groups. Group 1 (n = 5) had normal-appearing gastric squamous mucosal epithelium and had been killed due to problems unrelated to the gastrointestinal tract. Groups 2 (n = 5) and 3 (n = 5) had lesions induced in the gastric squamous epithelium by alternating 24 h periods of feed deprivation and ad libitum access to hay, for totals of 48 and 96 h feed deprivation, respectively. Following lethal injection of barbiturate, stomachs were removed and fixed by filling with 4-6 l 10% buffered formalin. Sections were made from lesions in the gastric squamous epithelium adjacent to the margo plicatus along the right side of the stomach/greater curvature and the lesser curvature. Measurements of total epithelial thickness, keratinised epithelium, nonkeratinised epithelium, epithelial projections, capillary extension into the epithelium and lamina propria thickness were made. The cross-sectional areas of arterial and venous vascular structures in the lamina propria at the lesions and their margins were measured using image analysis software. All horses, except one, in Group 2 developed erosions or ulcers in the gastric squamous epithelium after feed deprivation. There were several changes in the epithelium adjacent to erosions and ulcers, compared to normal epithelium, from horses in Groups 2 and 3: total epithelial thickness was significantly (P<0.05) greater, including both keratinised and nonkeratinised layers in most specimens; the length of epithelial projections and extent to which capillaries from the lamina propria extended toward the luminal surface, and the cross-sectional area of vascular structures (arterioles, capillaries, venules) in the lamina propria were significantly greater. Epithelial thickness of erosion beds was not significantly less than normal epithelium, although a greater proportion of the epithelium in erosions consisted of epithelial projections (Group 1, 23%; Group 2, 76%; Group 3, 72%). The cross-sectional area of vascular structures in the lamina propria beneath erosions was significantly greater than in normal mucosa only in Group 2 tissues, whereas in the lamina propria of ulcers it was significantly greater than in normal mucosa only in Group 3 tissues. The epithelial proliferation and increased vascular cross-sectional area in the lamina propria associated with peptic-induced gastric lesions are consistent with processes associated with the initiation of ulcer healing, and these changes temporally coincided with the initiation of peptic insult to the gastric squamous epithelium. These findings demonstrate that processes that promote ulcer healing begin soon after peptic injury and that they progress even with repeated peptic injury. Furthermore, our findings support observations that gastric ulcers often heal without medical intervention, and the theory that medications that reduce gastric acidity do not initiate healing, but rather facilitate ulcer healing by providing a microenvironment that is optimal for healing to proceed.  相似文献   

2.
Pasteurella multocida and Ascaridia galli are observed with high prevalences in free range chickens in Denmark, but the impact is unknown. A study was carried out to examine the interaction between A. galli and P. multocida in chickens and the impact on production.Five groups, each with 20 18-week-old Lohmann Brown chickens were infected. Group 1 was orally infected with 1000+/-50 embryonated A. galli eggs. Group 2 received 10(4) cfu P. multocida intratracheally. Group 3 was infected with A. galli and subsequently with P. multocida. Group 4 was infected with P. multocida followed by A. galli. Group 5 was the control. The study ran for 11 weeks where clinical manifestations, weight gain and egg production were recorded. Excretion of P. multocida was determined on individual basis and blood smears were made for differential counts. At the end of the study pathological lesions and the number of adult worms, larvae and eggs in the faeces were recorded.The birds were more severely affected when infected with both pathogens compared to single infections with A. galli or P. multocida, respectively. A lower weight gain and egg production was observed with dual infections. A. galli infection followed by a secondary P. multocida infection resulted in more birds with pathological lesions and continued P. multocida excretion.In conclusion a negative interaction between A. galli and P. multocida was observed and it is postulated that free range chickens are at higher risk of being subjected to outbreaks of fowl cholera when they are infected with A. galli.  相似文献   

3.
The aim of this study was to histochemically determine the substrates which have a bearing on the carbohydrate metabolism of the vaginal mucosa. Ten multiparous sows of the German Landrace breed were used. Samples were taken from the vagina with a biopsy device throughout the estrus cycle. Increased concentrations of glycoproteins and glycogen occur between proestrus and metestrus. Glycogen in the pig does not reach to vaginal lumen. It is most likely used for the biosynthesis of glycoproteins in deeper layers of the epithelium. Consequently, the drop in pH observed in the vaginal lumen during estrus must result from secretion of acidic glycoproteins by epithelial cells, rather than from the breakdown of glycogen to lactic acid. During proestrus and estrus, the superficial cell-layer of the epithelium secretes mucus. Mucus secretion plays an important role during estrus by supporting phagocytic activity of the neutrophilic granulocytes, and therefore the self-cleaning effect of the vagina. The lamina propria demonstrates cyclical changes as well: fibrocytes in the lamina propria contain increased amounts of cytoplasmic RNA during proestrus and estrus, indicating increased protein synthesis. The protein involved here is most likely a compound of hyaluronic acid-containing proteolycans, which are deposited in the interfibrous substance. RNA determined histochemically in the fibrocytes of the lamina propria is a reliable criterion for diagnosis of proestrus and estrus.  相似文献   

4.
The goal of this study was to morphologically characterize a ligated ileal loop model of Salmonella enterica serotype Typhimurium infection in rhesus macaques (Macaca mulatta) and to verify the occurrence of Salmonella-induced cell death in vivo. Eight adult healthy male rhesus macaques were used for ligated ileal loop surgery. Four macaques had been intravenously inoculated with simian immunodeficiency virus (SIV) mac251. Ileal ligated loops were inoculated with wild-type (WT) S. Typhimurium strain IR715 (ATCC14028 nal (r)), an isogenic noninvasive mutant strain (ATCC14028 nal (r) ΔsipAΔsopABDE2), or sterile Luria Bertani broth. Loops were surgically removed at 2, 5, and 8 hours post-inoculation (hpi). Intestinal samples were processed for histopathology, immunohistochemistry for detecting Salmonella, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and transmission electron microscopy. Combined histopathology scores were similar between SIV-infected and control macaques. As expected, the invasion-deficient mutant was less pathogenic than WT S. Typhimurium. Neutrophil infiltrate in the intestinal mucosa correlated with bacterial loads (r = 0.7148; P < .0001) and fluid accumulation (r = 0.6019; P < .0001) in the lumen of the intestinal loops. Immunolabeled WT S. Typhimurium was observed in the epithelium and lamina propria at the tip of the villi at 2 hpi, progressing toward deeper lamina propria at 5-8 hpi. Most TUNEL-positive cells localized to the lamina propria, and some had morphological features of macrophages. Ultrastructurally, bacteria were observed intracellularly in the lamina propria as well as within apoptotic bodies. This study provides morphological evidence of Salmonella-induced cell death in vivo in a relevant nonhuman primate model.  相似文献   

5.
为了研究贝氏莫尼茨绦虫自然感染绵羊对小肠黏膜免疫组织的影响,分别从宏观、微观及亚微观水平对自然感染贝氏莫尼茨绦虫的成年绵羊(感染组)肠道进行了细致地观察,并与正常成年绵羊(正常组)进行了比较.结果显示,感染组肠道所见虫体平均长度为1.5m,头节主要吸附在空肠淋巴集结分布丰富的部位,一般寄生数量为1～2条.眼观,虫体寄生部位黏膜增厚,表面有大量灰白色黏液附着,其间可见点状出血.镜下,局部黏膜上皮脱落,而在完整的黏膜上皮处,其上皮细胞、上皮内淋巴细胞、杯状细胞的数量都明显增多;固有层内毛细血管充血,淋巴细胞、浆细胞、弥散淋巴组织以及肠腺杯状细胞均有不同程度的增生,头节寄生处部分肠腺坏死;黏膜下层淋巴小结、淋巴集结显著增生,部分增生凸入固有层形成新的圆顶区;固有层与黏膜下层以及黏膜肌层可见大量嗜酸性粒细胞浸润.扫描电镜下,感染组肠黏膜上皮脱落;贝氏莫尼茨绦虫头节呈椭球状,有4个吸盘,无顶突,小沟,表面覆盖一层致密的微绒毛.研究结果表明,肠黏膜增厚,主要是局部黏膜免疫相关细胞在寄生虫虫体表面覆盖的微绒毛的不断刺激下,机体抗感染自身组织增生所致.成年绵羊对抗贝氏莫尼茨绦虫的感染可能是通过黏膜免疫相关组织增生来加强局部免疫力而实现的.  相似文献   

6.
本研究旨在探明犬子宫和卵巢在正常发情期与患子宫蓄脓时，其组织结构及乳铁蛋白（lactoferrin，LF）表达的变化特征。应用Masson’s、VVG、PAS组织化学染色方法观察乏情期、发情期、患子宫蓄脓时犬子宫及卵巢的组织结构特点，用免疫组织化学SP法观察LF的分布特征。结果显示，正常发情期犬：乏情期、发情期子宫内膜肌层厚度比分别为0.762 0、0.924 3；乏情期子宫固有层中胶原纤维含量大于发情期，发情期卵巢中胶原纤维含量大于乏情期；子宫血管层及卵巢血管内弹性膜清晰完整；子宫腺在乏情期时浅层管腔小，深层较大、腺管上皮为单层柱状上皮、上皮细胞及管腔内PAS阳性反应较强，发情期子宫腺管腔变大、腺管上皮为单层立方上皮、上皮细胞及管腔内有PAS阳性反应；子宫黏膜上皮在乏情期和发情期均为单层柱状上皮，但胞核位置不同，乏情期胞核位于中央，发情期胞核位于顶部。患子宫蓄脓犬：子宫内膜肌层厚度比为1.615 0；子宫固有层和卵巢中胶原纤维含量少于正常发情期；子宫腺管腔大，且形状不规则，管腔内有炎性细胞浸润，腺管上皮为单层立方上皮，有淋巴细胞位于基膜，上皮细胞及管腔内PAS阳性反应较弱；子宫血管层及卵巢血管内弹性膜较正常发情期变薄，且有断裂现象；子宫黏膜上皮为单层柱状上皮，胞核位于基底。LF在乏情期子宫腺上皮和卵巢中的表达水平高于发情期，而在子宫黏膜上皮中发情期的表达水平高于乏情期。患子宫蓄脓时犬子宫和卵巢中LF的表达水平均较低。综上表明，犬正常发情期与患子宫蓄脓时的子宫和卵巢组织结构特点显著不同，LF的表达水平也存在差异。  相似文献   

7.
The use of phytogenic bioactive compounds to control poultry helminthes is increasing in different production systems. In vitro and in vivo anthelmintic activity of citrus peels against Ascaridia galli was investigated. Ethanolic extracts of three citrus peels species were suspended in 0.5% dimethyl sulfoxide (DMSO) to form an experimental composition (EC). EC was mainly composed of Limonene (96%), followed by β-Pinene (1.5%), α-Pinene (0.5%), and Sabinene (0.3%). For in vitro investigation, adult A. galli worms (n=225) were collected from naturally infected chickens and distributed to 3 equal groups. Groups 1, 2, and 3 were exposed to Fenbendazole (0.5mg/ml), EC (50mg/ml), and 0.5% DMSO, respectively. For in vivo investigation, 200 Lohmann Selected Leghorns chicks were infected at 1-day old with 250 embryonated A. galli eggs. At 6 weeks of age, 150 A. galli infected birds were randomly allocated into 5 equal groups. Groups 1, 2, and 3 were treated with 300, 600, and 1200 mg EC kg(-1) body weight, respectively. Group 4 was treated with Fenbendazole (50 mg kg(-1)). Group 5 was left as control. Birds were euthanized 2-weeks post-treatment, and all worms were collected from their intestines. EC possessed significant (P<0.001) in vitro anthelmintic properties on live worms. No significant (P>0.05) difference was quantified between number of motile worms exposed either to EC or Fenbendazole 7h post-exposure. A significant (P<0.0001) reduction in fecal egg count was observed 14 days post-treatment with 1200 mg kg(-1) EC. No significant differences were observed in worm burden of the 300 mg EC-treated group compared to the controls. In contrast, the 600 and 1200 mg EC-treated groups showed significant (P<0.0001) reduction in worm burden. Fenbendazole was the most effective in reducing A. galli burden (Efficacy=97%) followed by 1200 mg EC kg(-1) (68%), 600 mg EC kg(-1) (66%), and 300 mg EC kg(-1) (5%). It is concluded that citrus peels extracts have potential anthelmintic properties against A. galli.  相似文献   

8.
OBJECTIVE: To validate use of canine colonic biopsy specimens obtained via endoscopy as a source of mucosal lymphocytes (ML) for flow cytometric analysis. SAMPLE POPULATION: Mucosal biopsy specimens from 10 adult dogs. PROCEDURE: Mucosal lymphocyte subsets obtained from excised colon were compared with ML subsets obtained from biopsy specimens obtained by use of an endoscopic forceps (6 dogs). Endoscopic colonic biopsy specimens from 4 other dogs were used to define whether obtained ML were predominantly of intraepithelial or lamina propria origin. Mucosal lymphocytes were isolated and labeled, using commercially available monoclonal antibodies directed against canine cell surface antigens. Lymphocyte subsets (cytotoxic or helper T cells; B cells) were determined by use of flow cytometric analysis. RESULTS: A large number of viable ML was obtained after dissociation of the colonic epithelium from excised colon (45.5 + 21.5 X 10(6)) and endoscopic (7.2+/-3.4 X 10(6)) biopsy specimens. Lymphocyte subsets obtained with both methods were identical for each dog and consisted predominantly of intraepithelial lymphocytes, with some lymphocytes from the lamina propria. Collagenase digestion of excised colon also yielded a large number of viable lymphocytes from the lamina propria (56.7+/-20.4 X 10(6)), but collagenase digestion of endoscopic biopsy specimens was less rewarding. CONCLUSION AND CLINICAL RELEVANCE: A representative sample of viable intraepithelial ML is obtainable from endoscopic biopsy specimens. Flow cytometric analysis, a minimally invasive technique, can be used to study ML of client-owned animals.  相似文献   

9.
Developmental changes in the mucous membrane of the rumen in bovine fetuses were observed by scanning electron microscopy (SEM). The ruminal epitheliums were obtained from 20 bovine fetuses and 4 bovine neonates. The samples were divided into 3 groups. Group 1 was examined in the epithelial surface by SEM. Group 2 was examined in the surface of the lamina propria and the reverse face of the epithelium by SEM, after having separate the epithelium from the lamina propria by Scallata's PBS-EDTA method. Group 3 was examined in histological aspect.
The ruminal papillae appeared first in early in the 5th month of gestation. On the other hand, the papillae of the lamina propria appeared first in early 4th month or late 4th month of gestation. It seemed that the formation of papillae in the lamina propria always preceded that of ruminal papillae. Meanwhile, some epithelial cells were exfoliated from the ruminal surface cells during late 4th month to early 5th month of gestation. Ruminal surface cells came to have keratohyaline granules from the 5th month of gestation onward.  相似文献   

10.
A 7-year-old, intact female mixed-breed dog was presented for evaluation of hematuria. Physical examination revealed a suprapubic mass. Ultrasonographic examination showed a large lobular mass occupying the urinary bladder. At the owners' request, the dog was euthanatized and a postmortem examination was performed. Necropsy confirmed the presence of a lobular mass of about 5- to 6-cm diameter protruding into the lumen of the bladder. Histologically, the mass was composed of a large number of atypical lymphoid cells in the lamina propria and mucosal epithelium. Immunohistochemically, the neoplastic cells expressed CD3 but not CD79alpha or keratin and vimentin, supporting a diagnosis of T-cell lymphoma.  相似文献   

11.
Atrophy of seminiferous tubules and interstitial fibrosis are frequently observed in aged horses. Samples from 8 male Thoroughbreds, age 4-24 years, were subjected to histological, electron microscopical and immunohistochemical examination and statistical analysis. There were statistically significant increases in collagen fibres in the lamina propria of seminiferous tubules and testicular interstitium in 3 horses age 23 and 24 years compared with 5 horses age 4-20 years (P<0.001). Lamina propria surrounding atrophic tubules was thickened by an increase in collagen type IV and elastic fibres and by proliferation of bizarre myoid cells. Basal lamina was also thickened but had decreased reactivity for collagen type IV. Some myoid cells changed morphologically to a swollen and irregular shape and contained abundant cytoplasmic organelles. Laser scanning microscopy revealed that cytoplasmic actin filaments were decreased; the remaining filaments were positive for alpha-smooth muscle actin and vimentin, and matrix metalloproteinase-2 was secreted. These myoid cells transformed into myofibroblasts. The changes are interpreted as evidence of injured structure and function of the lamina propria and basal lamina and may explain the functional decline of the blood-testis barrier. Myoid cells may play an important role in the progression of testicular fibrosis.  相似文献   

12.
The present study was made to know the morphology of the initial invasion and lesions involved in the intestinal colonization of Yersinia enterocolitica serovar O3 in the epithelium of Peyer's patches of mice. Microfold (M) cells formed a specific structure like a pseudopodium and the bacteria were observed on the surface of the pseudopodium-like structure 4 hr after oral administration of serovar O3. The colonies of serovar O3 were observed in the epithelium and the lamina propria of the Peyer's patches dome region, and the bacteria grown in the Peyer's patches were in direct contact with the lumen without covered with the host tissue 24 hr after the administration.  相似文献   

13.
The process of the disappearance of epithelial cells was examined in chicken cecal villi and follicle-associated epithelium (FAE). The apoptotic epithelial cells with intense DNA-fragmentation and their exfoliation were found in the villous tips. The epithelial cells with weak DNA-fragmentation were seen in the upper portion of the villi and their sparse exfoliations were also found there. Numerous epithelial cells in the intestinal lumen expressed the apoptotic features. A row of apoptotic epithelial cells with DNA-fragmentation was also found in the apical FAE, whereas no M cells exhibited any apoptotic signs. In all cecal regions, CD3+, CD8+, and TCR2+ lymphocytes were predominant in the epithelium at the upper portion of the villi and the FAE. CD4+ lymphocytes were mainly seen in the lamina propria. TCR1+ lymphocytes were not abundant in comparison with TCR2+ lymphocytes in the epithelium. TCR3+ T lymphocytes were rarely detected. These results suggest that the chicken cecal epithelial cells exfoliated into the lumen after the induction of the apoptosis, and that the induction may be involved with CD3+, CD8+, and TCR2+ lymphocytes. No death in M cells suggests that M cells may transform into microvillous epithelial cells.  相似文献   

14.
Comparative resistance to different isolates of Ascaridia galli was investigated in a local chicken breed from Jordan (LC) and in the Lohmann LSL white chicken (LW) strain. In two trials, birds of LC and LW were inoculated orally at 1-day old with 250 embryonated A. galli eggs. In the first trial a German source of A. galli was used, whereas in the second trial, a Jordan source of A. galli was used. At week 7 of infection, infected LC birds harbored significantly (P<0.05) fewer worms and excreted less A. galli eggs than infected LW birds. A. galli isolated from Jordan were less infectious than A. galli from Germany. Results suggest that the variation in genetic background between LC and LW is involved in the resistance to A. galli infection. A. galli isolates from different geographic areas differ in their ability to infect different chicken genotypes.  相似文献   

15.
Ultrastructure of the Uterotubal Junction in Preovulatory Pigs   总被引：2，自引：0，他引：2  
The ultrastructure of the surface epithelia from the uterotubal junction (UTJ), and the adjacent tubal isthmic and endometrial regions, was studied in preovulatory oestrus gilts, either unmated or inseminated 12 h before with fresh boar semen. The simple columnar epithelium of the UTJ consisted of non-ciliated (secretory) and ciliated cells. Secretory vesicles occurred in the secretory cells, especially in inseminated gilts. Lymphocytes, monocytes and macrophages were found dispersed basally among the epithelial cells. Phagocytosis of epithelial cells undergoing apoptosis was seen throughout the UTJ at oestrus, increasing after insemination. Neutrophilic granulocytes were found in the lamina propria of the uterine component of the UTJ, but only occasionally in the epithelium. After insemination, neutrophils invaded the uterine epithelium, to actively participate in intraepithelial phagocytosis or move into the lumen, engulfing spermatozoa. Neutrophils were absent from the UTJ proper and the isthmic epithelium, irrespective of the presence of spermatozoa in the lumen. Those spermatozoa in the uterine lumen that escaped phagocytosis had severely damaged plasma membranes, whereas those in the UTJ proper--concentrated towards the deep furrows of the diverticulae--mostly showed normal sperm ultrastructure.  相似文献   

16.
为探寻鸡回肠中T淋巴细胞及其亚群的发育规律,本试验通过免疫组织化学方法,应用CD3、CD4和CD8单克隆抗体研究鸡回肠中T淋巴细胞及其亚群出现、迁移、定位分布及数量变化过程.结果显示,CD3+、CD8+T淋巴细胞最初于18胚龄时出现,CD4+T淋巴细胞于出壳后1日龄时出现.在定位分布上,CD3+细胞在黏膜上皮内以及固有层中均匀分布,CD4+细胞以固有层中的分布为主,黏膜上皮内的分布较少.CD8+细胞最初主要分布在黏膜固有层中;随后,CD8+细胞逐渐向上皮内迁移;最终,黏膜上皮内出现广泛的CD8+细胞浸润.在数量变化上,CD3+、CD4+及CD8+整体呈逐渐增加趋势,第2周时阳性细胞数量稍有下降,21日龄时显著增加到达较高水平后保持稳定.结果表明,鸡出壳后,回肠的细胞免疫功能逐渐增强,并在21日龄时到达成熟水平.  相似文献   

17.
Groups of Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL) hens were reared under helminth-free conditions and kept afterwards together in a free range system. Mortality rate, body weight development, laying performance and faecal egg counts (FEC) were recorded during a 12 month laying period. At the end of the laying period, 246 LSL and 197 LB hens were necropsied and worms counted following the World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines. In addition adult Heterakis gallinarum and Ascaridia galli were sexed and measured for length. Significant (P<0.01) differences were observed in mortality rates between LSL and LB animals (12.9 vs. 5.7%). LSL hens showed significantly (P<0.05) higher FEC when compared with LB hens at almost all dates of monitoring. Almost all animals became infected with at least one helminth species. The most prevalent species were H. gallinarum, Capillaria spp. and A. galli. LB hens showed a significantly (P<0.05) higher average number of adult H. gallinarum, Capillaria spp. and tapeworms when compared with LSL animals. However, number of adult A. galli was in tendency lower in these animals. In total, LB had a significantly (P<0.05) higher worm burden than LSL (192.3 vs. 94.3). The estimated heritabilities for total worm burden were 0.23 (SE±0.12) in LSL and 0.75 (SE±0.21) in LB, respectively. The number of all different helminth species were positively correlated. The sex ratio of H. gallinarum and A. galli and the average worm lengths were not significantly (P>0.05) different between the genotypes. There was no significant phenotypic correlation between body weight and worm burden in LSL, whereas it was the case in LB (r=0.17, P<0.05). Based on the estimated heritabilities it is possible to select for helminth resistance in both genotypes.  相似文献   

18.
Porcine enzootic pneumonia (PEN), caused by Mycoplasma hyopneumoniae (Mh), has been described in pigs in all geographic areas. The disease is characterized by high morbidity and low mortality rates in intensive swine production systems. A morphologic and immunohistochemical study was done to determine the cellular populations present in lung parenchyma of infected pigs, with special attention to the bronchus-associated lymphoid tissue (BALT). Polyclonal and monoclonal antibodies were used for the detection of antigens of Mh, T lymphocytes (CD3+, CD4+, and CD8+), IgG+ or IgA+ lymphocytes, and cells containing lysozyme, S-100 protein, major histocompatibility complex class II antigen or myeloid-histiocyte antigen. Findings in lung tissues associated with Mh infection were catarrhal bronchointerstitial pneumonia, with infiltration of inflammatory cells in the lamina propria of bronchi and bronchioles and alveolar septa. Hyperplasia of mononuclear cells in the BALT areas was the most significant histologic change. The BALT showed a high morphologic and cellular organization. Macrophages and B lymphocytes were the main cellular components of germinal centers. T lymphocytes were primarily located in perifollicular areas of the BALT, lamina propria and within the airway epithelium, and plasma cells containing IgG or IgA at the periphery of the BALT, in the lamina propria of bronchi and bronchioles, in alveolar septa, and around bronchial submucosal glands. The hyperplastic BALT in PEN cases consisted of macrophages, dendritic cells, T and B lymphocytes, and IgG+ and IgA+ plasma cells. CD4+ cells predominated over CD8+ cells. Local humoral immunity appears to play an important role in the infection.  相似文献   

19.
1. The objective of the study was to compare the establishment and effect of Asaridia galli infections in 4 different layer-lines. 2. A total of 160 birds comprising 4 different commercial layer-lines, ISA Brown, New Hampshire, Skalborg and a cross of New Hampshire(NH) and Skalborg (Sk), were infected with A. galli eggs. The birds were examined for the presence of parasite eggs and parasites at weeks 3, 6 and 9 post infection (pi). 3. At week 6 pi the chickens of the NH line harboured more larvae compared with the three otherlines. The Sk line chickens excreted more A. galli eggs throughout the study compared with the other lines. Female worms in the Sk line were more fecund than the worms in the other lines. Male and female worms recovered from the Sk line at week 9 pi were longer. Male worms recovered from the NH line 6 weeks pi were shorter than male worms from the other lines. Female worms recovered from the NH line were shorter than the female worms from the ISA line and the Sk line. No differences were seen in weight gain among the 4 lines. 4. The results suggest that genetic factors are involved in the establishment and survival of A. galli in the intestine of layers. Further studies are needed to elucidate the genetic mechanisms behind the observed parasitological findings.  相似文献   

20.
The intracellular microsporidian parasite Loma salmonae affects salmonids of the genus Oncorhynchus and is a significant cause of economic losses in pen-reared Chinook salmon (O. tshawytscha) in British Columbia. Loma salmonae infection is easily recognized by the xenomas that form in the gills, but early stages of infection are difficult to detect in histologic sections. In situ hybridization (ISH), using an L. salmonae-specific digoxigenin-labeled single-stranded DNA probe, was used to detect the parasite during the early stages of infection. Loma salmonae was detected in the gut mucosal epithelium as early as 24 hours postexposure (PE), and it localized in the lamina propria of the intestine within 24 hours of infection. After the parasite was detected in the lamina propria, dividing merogonic stages in infected cells in the heart were detected by ISH as early as 2 days PE, providing the first evidence of parasitaemia and hematogenous distribution of this parasite in infected blood cells. The parasites inside the infected cells appeared to be undergoing merogony as they passed through the heart, indicating that proliferation may start at the site of infection, before the parasite arrives to the gills for their final developmental phase. This is the first time that L. salmonae passage through the intestinal wall and migration to the heart has been visualized; however, the identity of the cells harboring the parasite has yet to be determined.  相似文献   

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