热应激造成猪气管和肺损伤的组织病理学观察

把6头小型猪随机分成热应激组和常温对照组两组.人工气候室内,热应激组模拟夏季炎热气候,气温从26℃39℃ 24 h循环变温,在39℃时维持4h;常温对照组在24℃下饲养.试验持续10 d,热应激结束时剖杀试验猪,取其气管和肺组织进行固定、石蜡切片,分别进行H.E.染色、甲苯胺蓝染色和PAS染色,显微镜下观察各组气管及肺组织结构,并统计肥大细胞和杯状细胞数量.结果显示:热应激后猪的肺组织结构受到严重损伤,气管黏膜和肺组织中的肥大细胞和杯状细胞显著增多(P<0.05).该试验结果提示,肺组织结构损伤,气管黏膜及肺组织中肥大细胞及杯状细胞的增多是热应激造成猪呼吸障碍的形态学基础.     

First evidence of Kunjin strain of West Nile virus associated with saltwater crocodile (Crocodylus porosus) skin lesions

Recently, the Kunjin strain of West Nile virus (WNV_KUN) has been detected using qRT‐PCR in belly skin lesions of farmed juvenile saltwater crocodiles. This follows an established association between similar lesions and West Nile virus in American alligators. The lesions present as cutaneous lymphohistiocytic aggregates in the dermal layers of both species. While these lesion do not create an obvious defect on the live crocodile, upon tanning the lesion area collapses and does not uptake the dye evenly, thus reducing its aesthetic appeal. As a result, skins are being rejected jeopardising the economic viability of the Australian crocodile industry. Over 50 skin lesions have since been confirmed as WNV_KUN‐positive and preliminary evidence of lesion restructuring is presented. Horizontal transmission of WNV_KUN by mosquitoes is well‐established but other transmission routes, such as ingestion and cloacal shedding, need further evaluation. An infection trial is currently underway to ensure WNV_KUN is the causative agent of these skin lesions.     

Influence of environmental conditions in a glasshouse on conidia ofBotrytis cinerea and on post-harvest infection of rose flowers

Quantification and horizontal distribution of air-borne inoculum ofBotrytis cinerea in a rose crop in a glasshouse of 300 m² was studied in 1991 and 1992. Conidia ofB. cinerea were caught in spore traps consisting of an agar medium selective forB. cinerea in Petri dishes placed within the crop, at flower height 1 m above the ground. Spore catches were counted as colonies, after incubation. Lesions due to conidial infection were counted on petals of rose flowers, also after incubation. Relative humidity (RH) and temperature within the glasshouse and global radiation and windspeed outside were recorded during the experiments. The horizontal distribution ofB. cinerea in a rose crop grown under glass was fairly uniform in both years. In 1991 a clear seasonal pattern in the number of colonies could not be found. In 1992 the number of colonies were high in August, September and October. The number of lesions on rose flowers showed a distinct pattern in both years. In August, September and October many lesions were counted whereas in the other months few lesions appeared. In linear regression analysis, variation in numbers of colonies (spore catches) could not be explained by environmental factors recorded during the experiments. Linear regression accounted for 76 and 63% of the variation in the number of lesions on rose flowers in 1991 and 1992, in terms of relative humidity (positively correlated), global radiation outside the glasshouse (negatively correlated) and, numbers of colonies on spore traps (positively correlated). The results in the rose crop suggest that RH, global radiation and spore density in glasshouses are important variables in regulating the numbers of lesions during storage and transport. The numbers of spores in glasshouses are dependent on the production system. A glasshouse with a system resulting in wet dead tissue on the ground give higher amount of spores in the glasshouse air and through that high numbers of lesions on flowers. On roses outside the glasshouses very high numbers of lesions were counted sometimes, mostly during and after rain showers, as a result of rain-deposition of spores onto the flowers.     

Relationship between herd-level incidence rate of energy-related postpartum diseases,general risk factors and claw lesions in individual dairy cows recorded at maintenance claw trimming

Background

Laminitis and energy-related postpartum diseases share several risk factors, indicating a common etiology. Thus, a herd’s incidence rate of energy-related postpartum diseases, such as displaced abomasum and clinical ketosis, might reflect the likelihood of cows to suffer from laminitis-related claw lesions. The aim of this study was to investigate the association between herd-level incidence rate of displaced abomasum and clinical ketosis, general risk factors, and claw lesions in individual cows recorded at maintenance claw trimming.

Methods

The dataset consisted of 6773 trimmings, performed between 2004 and 2006 by professional trimmers, from 3607 Swedish Red and Swedish Holstein cows in 26 herds. The herds were classified as having a high, inconsistent-high or low incidence rate of energy-related postpartum diseases, based on the number of recorded cases of veterinary-diagnosed displaced abomasum and clinical ketosis in the Swedish national animal disease recording system during 2002 to 2006, and observations and interviews in connections with herd visits. Generalized linear mixed models were used to investigate the association between herd-level incidence rate of energy-related postpartum diseases and laminitis-related lesions including sole ulcer and sole hemorrhage; and hygiene-related lesions including interdigital dermatitis, digital dermatitis, heel-horn erosion, verrucose dermatitis, and interdigital hyperplasia; and absence of any claw lesion. Systematic effects, including first-order interactions, with P < 0.05 were included in the models. Herd classification was forced into the models, and a random effect of herd was included.

Results

In comparison to herds with a high incidence rate of energy-related postpartum diseases, low-incidence herds showed a lower odds ratio (OR; 0.2) for laminitis-related lesions in cows trimmed during the summer months. Low-incidence herds also showed numerically lower OR estimates for laminitis-related lesions in all parity classes and a numerically lower OR for hygiene-related lesions. In addition, low-incidence herds showed tendencies towards a numerically higher OR for absence of any lesion, irrespective of trimming season or parity.

Conclusions

Only a few statistically significant associations were found, but several tendencies pointed towards better claw health in herds with low as compared with high incidence rate of energy-related postpartum diseases.     

实验性鸡大肠杆菌病的超微动态病理变化

10～ 12日龄 SPF鸡 180只 ,随机分为 4组 ,分别气管内注射致病性大肠杆菌 O18分离株 (大肠杆菌接种组 )、低致病性禽流感病毒 (mildly pathogenic avian influenza virus,MPAIV) H9N2株 (MPAIV接种组 )、先接种 MPAIV再接种大肠杆菌 (混合接种组 ) ,并设健康对照组 ,分别于接种后不同时间 ,取气管、肺、气囊、胸腺、法氏囊、脾、肝和肾组织 ,制作超薄切片 ,电镜观察。结果表明 ,MPAIV与大肠杆菌混合接种组比大肠杆菌接种组出现病变的时间早、恢复慢 ;在大肠杆菌接种组 ,接种后 3h气囊上皮和间质细胞中都可见典型的大肠杆菌 ;在混合接种组 ,接种后 3h,气囊间质细胞的吞噬泡中可见多个 MPAIV粒子。由此认为 ,MPAIV可使鸡大肠杆菌病严重化 ,大肠杆菌对 MPAIV的入侵和在鸡体内的复制可能有促进作用。     

齐墩果酸抑制骨关节炎大鼠肌肉氧化损伤及软骨下骨异常骨重建

旨在探讨齐墩果酸（oleanolic acid,OLA）对于骨关节炎（osteoarthritis,OA）大鼠肌肉氧化损伤和软骨下骨异常骨重建的作用。选取18只Sprague-Dawley大鼠随机分为3组：对照组（CON组）、模型组（OA组）和齐墩果酸给药组（OLA组）。OA组和OLA组利用前十字韧带切断联合半月板部分切除手术（ACLT+PMMx）建立大鼠膝OA模型,CON组进行假手术。OLA组大鼠每天灌胃50 mg·（kg·d）^-1 OLA,CON组和OA组灌服等体积含20 mL·L^-1 Tween 80的无菌生理盐水,连续给药4周后取膝关节、股四头肌和血清样本。利用伸膝发声试验和热敏感试验检测大鼠关节疼痛情况。酶联免疫吸附测定试验检测大鼠肌肉中柠檬酸合酶（citrate synthase,CS）、肌球蛋白重链（myosin heavy chain,MHC）、白细胞介素1（interleukin 1,IL-1）和IL-6的水平,以及大鼠血清中骨钙素（osteocalcin,OCN）和Ⅰ型胶原羧基末端肽（C-terminal typeⅠ collagen telopeptide,CTX-Ⅰ）的水平。免疫印迹法检测肌肉组织Nrf2/NQO1/HO-1通路蛋白表达情况。微型计算机断层扫描（Micro-CT）用于软骨下骨扫描和骨组织显微结构定量分析。结果显示,与OA组比较,OLA可以降低OA疼痛评分（P<0.05）,激活肌肉Nrf2/NQO1/HO-1通路,促进肌肉CS和MHC表达,并下调IL-1和IL-6水平（P<0.05）。此外,补充OLA后大鼠软骨下骨的骨体积分数（BV/TV）、骨矿物质密度（BMD）和骨小梁厚度（Tb.Th）显著升高（P<0.05）,骨代谢标志物OCN和CTX-Ⅰ表达显著降低（P<0.05）。结果提示,OLA能够抑制OA大鼠关节疼痛反应,通过调控Nrf2/NQO1/HO-1通路抑制OA大鼠肌肉功能障碍,改善OA早期软骨下骨生物力学性能和微结构改变,从而延缓OA大鼠软骨下骨异常骨重建的发生。