日本大耳白兔TLR3部分cDNA克隆及mRNA在组织中的分布

采用RT—PCR技术从日本大耳白兔的脾脏组织克隆出兔的Toll样受体基因3（命名为。TLR3），并对其mRNA在兔的17种组织中的分布情况进行了检测。结果显示，RTLR3核苷酸序列与GenBank中登载的穴兔（Oryctolagus cuniculus）TLR3序列（登录号：NM_001082219）相似性为100％；兔的胸腺、脾脏、睾丸等14种组织中检测出TLR3 mRNA的转录产物，而在骨骼、胃和皮肤中未能发现。推导的氨基酸序列同源性比对表明，兔TLR3与人、野猪、牛、猫、褐鼠等动物的同源性最高，为80％-85％；与原鸡同源性次之，为61％；与草鱼、绿河豚等同源性在45％～48％之间；系统进化树分析表明，兔TLR3与马的亲缘关系最接近，与猪、人／绵羊、牛、猩猩／猫的亲缘关系依次渐远，与鼠的亲缘关系最远。可见，TLR3在不同种属动物及不同组织中所起的作用具有生物多样性。     

白牛槭休眠芽苞的离体培养

以白牛槭休眠芽为外植体,采用不同培养基和不同接种方法进行组织培养研究。结果表明:拨去白牛槭休眠芽鳞片,露出叶原基2~4 mm,进行接种的萌芽率最高;且在培养基MS+BA 0.5 mg/L+KT 0.01 mg/L+蔗糖30 g/L+琼脂7.5 g/L,pH 5.6~5.8中培养效果最好。     

Needle Collection Time for Nutrient Evaluation in Christmas Tree Production

Christmas tree needle sampling to evaluate nutrient need is an established practice. Data to support the recommended fall sampling time in Oregon and Washington were not found. In addition, the recommendation for needle sampling of Fraser fir in North Carolina was made without data from winter months. The goal for this article is to affirm or modify recommended needle sampling time. Needles of Douglas fir, Turkish fir, Nordmann fir, Noble fir, Grand fir, and Fraser fir Christmas trees were collected monthly for a year, dried, and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and boron (B). No single period was found for any species when needle nutrient concentration was stable for all elements determined. Needle collection time was chosen by integrating cultural practices, likelihood of nutrient deficiency, and needle nutrient concentration changes for species grown in an area. Needle collection is recommended during February in western Oregon and Washington. The current sampling time, fall, is logical for Fraser fir Christmas tree production in North Carolina.     

不同水分状况对箭杆杨叶中输导组织及叶肉组织的影响

自然条件下水分状况对箭杆杨叶中输导组织及叶肉组织有一定的影响。水分状况好的叶中导管管腔直径大于水分状况差的，而管壁厚度却相反，水分状况差的导管管壁厚度大于水分状况好的。此点与试验条件下所得的结果略有差异，原因在于，试验条件下所用的材料为植物的幼茎或同化枝，而此项工作所用的材料为叶，在对干旱环境及水分状况变化的适应上，叶比茎或同化枝更为敏感。叶肉中栅栏组织在水分状况较差时发育程度比水分状况时高。无论     

Zonal dermal separation: a distinctive histopathological lesion associated with hyperelastosis cutis in a Quarter Horse

This case report describes a distinctive deep cutaneous lesion in a 1-year-old Quarter Horse filly with hyperelastosis cutis. The horse had a typical clinical presentation of hyperelastic skin associated with a 6-month history of cutaneous wounds that developed following minor cutaneous trauma. Punch biopsies of skin from the affected horse were thinner than similar biopsies from an age- and breed-matched control. Significant microscopic lesions were not seen in cutaneous punch biopsies stained with haematoxylin and eosin and Masson's trichrome stains, but the ultrastructure of the dermis from the affected horse was characterized by variation in collagen fibre diameter and loose packing of collagen fibres within bundles. The horse was euthanized and necropsied, and full-thickness sections of skin were collected and examined microscopically. Affected skin was of normal thickness; however, the deep dermis contained a distinctive horizontal linear zone in which separation of collagen bundles resulted in the formation of large empty cleft-like spaces between the upper and lower regions of the deep dermis. We suggest the term 'zonal dermal separation' for this microscopic lesion. Incisional full-thickness skin biopsies should be taken in suspected cases of equine hyperelastosis cutis because punch biopsies may not obtain enough deep dermis to adequately represent pathological change in the skin of horses with this disorder.     

New severe strains of Melon necrotic spot virus: symptomatology and sequencing

New strains of Melon necrotic spot virus (MNSV), designated MNSV-YS and MNSV-KS, caused much more severe growth retardation on melon plants than MNSV-NH, which was previously reported as the most severe strain of MNSV in Japan. MNSV-YS spread much more quickly than MNSV-NH in infected plants, and induced more severe growth retardation, even though the appearance of necrotic lesions on inoculated cotyledons was much slower. MNSV-KS had properties intermediate between those of the other two strains. The results suggest that faster-spreading strains can multiply more rapidly as a result of lower levels of activity in inducing necrotic lesions in melon plants. The complete sequences of MNSV-YS and MNSV-KS were determined, and an RT–PCR–RFLP method based on these sequences was successfully developed to detect and discriminate between the three strains.     

ECHOCARDIOGRAPHIC AND DOPPLER DIAGNOSIS: FIRST CASE OF ATRIAL SEPTAL ANEURYSM IN A CAT

A 6-year-old female cat developed pleural and abdominal effusion. Cardiac ultrasound and 2D color tissue Doppler imaging revealed restrictive cardiomyopathy with severe biatrial dilatation and hypertension. This cardiomyopathy was associated with atrial septal aneurysm and a patent foramen ovale. The atrial septal aneurysm involved the entire atrial septum. Necropsy and histological examination confirmed all these findings. ASA is a rare malformation and, as in this cat, it generally occurs concomitantly with congenital or acquired heart disease and may be explained by greater pressure in one atrium, leading to controlateral protrusion of the atrial septum.     

A viability study of Fallopia japonica stem tissue

Vegetative regeneration of intact and split nodes of Fallopia japonica (Houtt.) Ronse Decraene was the focus of this greenhouse experiment. Stem material, collected in May, July and September 1997, was cut into 40-mm-long sections and incubated on the surface of moist compost in a greenhouse. All samples showed some regrowth of buds and new shoots from both intact and split nodes in any season. A maximum number of 0.25 buds per intact node was recorded after 6 days in a spring experiment. The vegetative regrowth of shoots generally appeared after 1 week and increased over time with a maximum mean height of 77 mm after 27 days and a maximum number of 0.39 shoots per intact node after 13 days. Adventitious roots developed from both intact and split nodes during both summer and autumn experiments. From this study, a maximum of 90 stem tissue propagules per square metre of F. japonica stand has been estimated. If the plant is cut as part of a control programme, these propagules can produce shoots with growth rates of up to 2.9 mm per day with a good chance of the development of adventitious roots. This considerable potential for vegetative regeneration of stem tissue shows a clear need for guidelines on the safe management and disposal of F. japonica plant material.     

Residues of zeta‐cypermethrin in bovine tissues and milk following pour‐on and spray application

The depletion of zeta‐cypermethrin residues in bovine tissues and milk was studied. Beef cattle were treated three times at 3‐week intervals with 1 ml 10 kg^?1 body weight of a 25 g litre^?1 or 50 g litre^?1 pour‐on formulation (2.5 and 5.0 mg zeta‐cypermethrin kg^?1 body weight) or 100 mg kg^?1 spray to simulate a likely worst‐case treatment regime. Friesian and Jersey dairy cows were treated once with 2.5 mg zeta‐cypermethrin kg^?1 in a pour‐on formulation. Muscle, liver and kidney residue concentrations were generally less than the limit of detection (LOD = 0.01 mg kg^?1). Residues in renal‐fat and back‐fat samples from animals treated with 2.5 mg kg^?1 all exceeded the limit of quantitation (LOQ = 0.05 mg kg^?1), peaking at 10 days after treatment. Only two of five kidney fat samples were above the LOQ after 34 days, but none of the back‐fat samples exceeded the LOQ at 28 days after treatment. Following spray treatments, fat residues were detectable in some animals but were below the LOQ at all sampling intervals. Zeta‐cypermethrin was quantifiable (LOQ = 0.01 mg kg^?1) in only one whole‐milk sample from the Friesian cows (0.015 mg kg^?1, 2 days after treatment). In whole milk from Jersey cows, the mean concentration of zeta‐cypermethrin peaked 1 day after treatment, at 0.015 mg kg^?1, and the highest individual sample concentration was 0.025 mg kg^?1 at 3 days after treatment. Residues in milk were not quantifiable beginning 4 days after treatment. The mean concentrations of zeta‐cypermethrin in milk fat from Friesian and Jersey cows peaked two days after treatment at 0.197 mg kg^?1 and 0.377 mg kg^?1, respectively, and the highest individual sample concentrations were 2 days after treatment at 0.47 mg kg^?1 and 0.98 mg kg^?1, respectively. © 2001 Society of Chemical Industry