养殖鲟鱼肝硬化病的器官和组织病理学观察

为了明确养殖鲟鱼Acipenser sinensis肝硬化的致病因素及诊治方法,在3批次现场采集病样(共计41尾)中,选取9尾具典型症状的患病鲟鱼,对其重要组织器官进行采样,制作石蜡切片,H-E染色,对自然发病的疑似肝硬化杂交鲟进行了病理解剖观察和组织病理学研究,并对其组织病理变化及发病机理进行了分析。结果表明:1、2、3、9号病样表现出明显肝组织病变,肝组织内出现弥漫性纤维增生等典型肝纤维化症状;脾充血,空泡变性、坏死;胃、肠充血,炎性细胞浸润,肠绒毛坏死甚至脱落;其他器官(鳃、心等)组织轻微淤血、炎症;结合各器官症状和组织病变及参考相关研究,确定本病例为鲟鱼肝病,具体诊断为鲟鱼肝硬化。研究表明,鲟鱼肝硬化的器官和组织病理学诊断特征为肝淤血和溃疡,肝腹水,肝血窦扩张、炎性细胞浸润、组织空泡化、组织纤维化。     

Evaluation of fixation methods for demonstration of Neoparamoeba perurans infection in Atlantic salmon,Salmo salar L., gills

Formaldehyde‐based fixatives are generally employed in histopathology despite some significant disadvantages associated with their usage. Formaldehyde fixes tissue by covalently cross‐linking proteins, a process known to mask epitopes which in turn can reduce the intensity of immunohistochemical stains widely used in disease diagnostics. Additionally, formaldehyde fixation greatly limits the ability to recover DNA and mRNA from fixed specimens to the detriment of further downstream molecular analyses. Amoebic gill disease (AGD) has been reliably diagnosed from histological examination of gills although complementary methods such as in situ hybridization (ISH) and polymerase chain reaction (PCR) are required to confirm the presence of Neoparamoeba perurans, the causative agent of AGD. As molecular techniques are becoming more prevalent for pathogen identification, there is a need to adapt specimen collection and preservation so that both histology and molecular biology can be used to diagnose the same sample. This study used a general approach to evaluate five different fixatives for Atlantic salmon, Salmo salar L., gills. Neutral‐buffered formalin and seawater Davidson's, formaldehyde‐based fixatives commonly used in fish histopathology, were compared to formalin‐free commercial fixatives PAXgene^®, HistoChoice?MB* and RNAlater?. Each fixative was assessed by a suite of analyses used to demonstrate AGD including routine histochemical stains, immunohistochemical stains, ISH and DNA extraction followed by PCR. All five fixatives were suitable for histological examination of Atlantic salmon gills, with seawater Davidson's providing the best quality histopathology results. Of the fixatives evaluated seawater Davidson's and PAXgene^® were shown to be the most compatible with molecular biology techniques. They both provided good DNA recovery, quantity and integrity, from fixed and embedded specimens. The capacity to preserve tissue and cellular morphology in addition to allowing molecular analyses of the same specimens makes seawater Davidson's and PAXgene^® appear to be the best fixation methods for diagnosis and research on AGD in Atlantic salmon gills.     

复方参芩对人工感染心肌炎型细小病毒病犬的疗效试验

本试验为探讨复方参芩对人工感染心肌炎型细小病毒病犬的疗效,将犬分为空白对照组、模型组、阳性药物对照组、复方参芩组,用犬细小病毒接种建立动物模型,用复方参芩预防犬细小病毒病,应用生物信号采集系统的心电图技术测定试验动物的心率、心电图,取心脏石蜡包埋、切片、镜检。试验结果显示,攻毒后3 d,模型组犬心率和心电图异常率增加,心肌损害严重;复方参芩组犬心率保持正常,心电图异常率显著低于模型组犬,心肌组织与空白对照组相比差异不显著。试验犬感染病毒第5天,空白对照组犬未出现死亡,模型组犬死亡率为100%,复方参芩组保护率为80%,阳性药物对照组保护率为70%。表明复方参芩能有效预防心肌炎型犬细小病毒病。     

清远麻鸡禽白血病病理组织学观察和PCR诊断

本试验选择临床症状明显、经禽白血病抗原检测为阳性的15只祖代清远麻鸡,采集肝脏、脾脏、肾脏等器官进行病理组织学观察和PCR诊断。结果显示,从病理组织切片中观察到肝脏、肾脏、脾脏、骨髓、腺胃、心脏、肺脏、胰腺和卵巢等组织中有大量的淋巴母细胞呈灶状增生或散在分布,以及少量的成髓细胞增生。禽白血病病毒主要侵害祖代清远麻鸡机体的内脏器官和骨髓,对大脑等神经组织损害较轻;PCR扩增结果表明,所采集的15份样品均能扩增出545 bp左右的特异性片段,证明15份组织样品中均存在J亚型禽白血病病毒。     

Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence

Juvenile pink salmon, Oncorhynchus gorbuscha (Walbaum), in the Broughton Archipelago region of western Canada were surveyed over 2 years for sea lice (Lepeophtheirus salmonis and Caligus clemensi), gross and microscopic lesions and evidence of infections with viruses and bacteria. The 1071 fish examined had an approximate ocean residence time no longer than 3 months. A high prevalence of degenerative liver lesions, renal myxosporean parasites and a low prevalence of skin lesions and sea lice were observed. No indications of viral or bacterial diseases were detected in either year. The monthly prevalence of sea lice in 2007 (18-51%) was higher than in 2008 (1-26%), and the infestation density exceeded the lethal threshold in only two fish. Degenerative hepatic lesions and renal myxosporean parasites occurred in approximately 40% of the pink salmon examined in June of both years, and the peak monthly prevalence of hepatocellular hydropic degeneration was greater in 2007 (32%, in May) than in 2008 (12%, in June). Logistic regression analysis found skin lesions and hepatocellular hydropic degeneration significantly associated with sea lice. Most parasites and lesions occurred during both years, but the prevalence was often higher in 2007. Fish weight was 35% less in June 2007 than in June 2008, but condition factor was not different. Further research is required to monitor inter-annual variations and aetiology of the liver lesions and to assess their potential role on pink salmon survival.     

Histology and growth performance in rainbow trout (Oncorhynchus mykiss) in response to increasing dietary concentration of sparteine,a common alkaloid in lupins

This study evaluated the effects of sparteine, a lupin alkaloid, on growth and organ histology in rainbow trout. Eight diets with increasing concentrations of sparteine (0, 50, 100, 250, 500, 1000, 2500 and 5000 mg kg^?1) were fed to triplicate groups of 61‐g fish for 62 days. Survival was not affected by the dietary treatments. Weight gain, feed conversion efficiency and feed intake decreased in a quadratic manner for sparteine levels above 100 mg kg^?1. No effects were observed at inclusion levels ≤100 mg kg^?1. Whole‐body lipid and dry matter was depleted in a quadratic manner, while protein and ash were not affected. No tissue alteration attributable to sparteine alkaloid intake was found in liver, kidney, spleen or mid and distal intestines. At sparteine levels above 1000 mg kg^?1 of diet, the weight of the intestines and the liver relative to body weight decreased, whereas the weight of the spleen increased. These effects were likely associated with low feed intake and starvation. These results indicate that dietary sparteine alkaloid primarily reduced palatability, but did not impair the health of the fish. The level of sparteine should be kept below 100 mg kg^?1 in trout diets to ensure rapid growth.     

斑鳢嗜水气单胞菌病病原的鉴定及其病理组织学的研究

从患病斑鳢Channamaculata体内分离到一株细菌（FS20100810）,经人工感染试验证实为该病的病原菌。该菌株兼性厌氧,为革兰氏阴性杆菌,能运动,无芽孢,无荚膜,能发酵葡萄糖、蔗糖、麦芽糖、甘露醇、七叶苷,氧化酶反应、接触酶反应、吲哚试验和M．R．试验均为阳性。该菌株对斑鳢的半致死浓度为6．83×10^5cfu／mL。16SrRNA基因序列与嗜水气单胞菌Aeromonashydrophila的同源性为99．6％。药敏试验结果显示,该菌株对氧氟沙星、菌必治、先锋噻肟等抗生素敏感,对复方新诺明等中度敏感,对苯唑青霉素、青霉素G、氨苄青霉素耐药。通过对人工感染的斑鳢进行组织切片观察,发现病鱼的鳃、心肌、肝脏、肾脏、脾脏、肠道等器官组织均有明显的病理变化。