Dynamic Compression of the Cervical Spinal Cord: A Myelographic and Pathologic Investigation in Great Dane Dogs

The authors report the radiographic and pathologic findings in 10 Great Dane dogs with the wobbler syndrome. In all 10 dogs it was possible to demonstrate myelographically that there was cervical spinal cord compression at 1 or 2 sites. The spinal cord compression was mainly dynamic in nature, as degree of compression increased in extension and decreased in flexion of the neck in 8 dogs. In 1 dog with deformed vertebral bodies (G6 and C7), compression increased slightly in flexion of the neck. In another dog, compression was lateral and could only be seen in the ventrodorsal view.The macroscopic findings substantiated the radiologic findings. The cause of the spinal cord compression was in 8 dogs a decrease in the dorsoventral diameter of the orifice of the vertebral canal of 1 or 2 vertebrae in combination with deformation and elongation of 1 or several vertebral arches. In extension of the neck, the cervical spinal cord was squeezed between the anterior tip of the elongated vertebral arch and the caudodorsal rim of the body of the adjacent cranial vertebra.Histologic examination was made of the spinal cord in 5 dogs and the compressive lesions that were found could explain the neurologic signs.In the discussion, the question is raised as to why pain is not a prominent sign in dogs with the wobbler syndrome in contrast to in dogs with cervical disc protrusion. It is believed that the inflammatory foreign body reaction, triggered by the protruded calcified nucleus pulposus is the main cause of pain in the disc protrusion syndrome. In the wobbler syndrome there is no obvious inflammatory reaction in the epidural space.Finally, the possible etiologic factors oC importance for the deformation oC the cervical vertebrae in wobblers are discussed. There are indications that both overnutrition and a genetic trait for rapid growth are of importance.     

Cerebrospinal Fluid Analysis and Clinical Outcome of Eight Dogs With Eosinophilic Meningoencephalomyelitis

Eight dogs, 14 weeks to 5.5 years of age, had signs of diffuse or multifocal meningoencephalomyelitis. The total white cell counts of the cerebrospinal fluid (CSF) ranged from 11 to 5,550 cells/microliters; the percentage of eosinophils ranged from 21% to 98%. The total CSF protein content range was 19 to 1,430 mg/dl. On necropsy, two dogs had granulomatous encephalomyelitis due to protozoan infection. The other six dogs, of which three were Golden Retriever dogs, appeared to have an idiopathic eosinophilic meningoencephalitis; four of these dogs recovered. The significance of eosinophils in CSF and the possible emergence of a new encephalitic syndrome of dogs involving a hypersensitivity to an unknown agent is also discussed.     

Spinal Cord Swelling as a Myelographic Indicator of Prognosis: A Retrospective Study in Dogs With Intervertebral Disc Disease and Loss of Deep Pain Perception

The association of myelographic spinal cord swelling with neurological outcome was examined in 46 dogs with intervertebral disc disease and absence of deep pain perception (DPP). Spinal cord swelling was measured by calculating a ratio of the length of the loss of the myelographic dye column to the length of the second lumbar vertebra (L2). A positive neurological outcome was defined as return of voluntary motor function. A cut-off value for swelling:L2 of 5.0 was established by the creation of a receiver operator characteristic curve. Using a swelling:L2 ratio of 5.0 as a cutoff for indication of neurological recovery yielded a sensitivity of 74% and a specificity of 61%. Overall neurological recovery rate was 43%. Dogs with spinal cord swelling: L2 ratios less than 5.0 had a recovery rate of 61%, whereas dogs with a ratio greater than or equal to 5.0 had a recovery rate of 26%. Evaluation of these data by chi square analysis confirmed that a ratio less than 5.0 was associated with a positive outcome, and a ratio greater than or equal to 5.0 was associated with a negative outcome, ( P <.05). Although other factors, such as duration of neurological signs, affect neurological outcome in dogs with no DPP, evaluation of myelographic spinal cord swelling can assist in establishing a prognosis.     

Fibrocartilaginous Embolism of the Spinal Cord in Dogs: Review of 36 Histologically Confirmed Cases and Retrospective Study of 26 Suspected Cases

Clinical features of 36 dogs with histologically confirmed fibrocartilaginous embolism (FCE) were contrasted with those of 26 dogs in which FCE was suspected based on characteristic clinical findings and the absence of compressive spinal cord disease on myelography. Dogs with confirmed and suspected FCE were of similar signalment, and had acute, nonprogressive dysfunction, often associated with trauma or exercise. The "suspected" group included fewer giant breeds and more often had asymmetric lesions, intact nociception, and upper motor neuron involvement. Dog size and severity of clinical signs probably contributed to owners choosing euthanasia in dogs with confirmed lesions. Accordingly, data from such patients may be skewed relative to these clinical features. J Vet Intern Med 1996;10:241–245. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Comparison of Hypothermic and Normothermic Spinal Cord Perfusion in the Dog

Lumbar dorsal laminectomies were performed on 24 dogs, and exposed spinal cords were subjected to various time-temperature combinations of perfusion according to the following schedule: 1) 30 minutes of hypothermic perfusion—6 dogs; 2) 30 minutes of normothermic perfusion—6 dogs; 3) 120 minutes of hypothermic perfusion—6 dogs; and 4) 120 minutes of normothermic perfusion—6 dogs.
Surgery, cord perfusion, and exposure of the dorsal aspects of the spinal cord to the epaxial musculature for 5 days following surgery produced histopathologic changes in the dorsal aspects of the cord, especially around the dorsal root area. Hypothermic spinal cord perfusion for 120 minutes produced a marked deleterious effect on normal spinal cord function and spinal cord tissue. Spinal cords exposed to 30 minutes of hypothermic or normothermic perfusion or 120 minutes of normothermic perfusion had less severe clinical and histopathologic changes than those exposed to 120 minutes of hypothermic perfusion. Hypothermic perfusion for 30 minutes and 120 minutes affected not only dorsal aspects of the cord, but also the grey matter. The most severe change in grey matter occurred in cords perfused for 120 minutes.     

除草剂敌草快(Diquat)所致的大鼠胎儿动脉管收缩与血管紧张素及其受体的关系

为研究除草剂敌草快（Diquat）对胎儿动脉管的毒性作用机理，进行了以下3个试验：（1）取妊娠21d大鼠20只，随机分成5组，每组4只，于不同时间皮下注射敌草快7mg／kg，对照组注射等量生理盐水。取出胎儿，冷冻后，观察动脉管收缩情况。（2）取妊娠21d大鼠16只，随机分成4组，每组4只。试验1组母体皮下注射敌草快7mg／kg，2、3组通过子宫壁给胎儿分别注射D．05mL生理盐水和0．05mL（0．05mg）非选择性血管紧张素（ET）受体ETA／ETB拮抗药TAK-044后，再母体皮下注射敌草快7mg／kg，取出胎儿，观察动脉管收缩情况。（3）取妊娠21d大鼠16只，随机分成4组，每组4只。试验1组母体皮下注射敌草快7mg／kg，2、3组通过子宫壁给胎儿分别注射0．05mL生理盐水和0．05mL（0．02mg）选择性ETA受体拮抗药BQ-123后，再母体皮下注射敌草快7mg／kg，取出胎儿，观察动脉管收缩情况。结果表明，敌草快对妊娠末期胎儿动脉管有毒性作用，胎儿注射TAK-044和BQ-123都不引起动脉管收缩。由此可见，敌草快所致胎儿动脉管收缩与ET有关，且有ETA受体作为媒介参与。     

Laminotomy of the Axis for Surgical Access to the Cervical Spinal Cord A Case Report

A cranially hinged laminotomy of vertebra C2 was used to expose the cervical spinal cord of a dog with a meningioma in the region of the atlantoaxial articulation. By preserving the dorsal atlantoaxial ligament, the technique seemed to result in greater and more physiologic stability between the atlas and axis than dorsal laminectomy and prosthetic replacement of the dorsal atlantoaxial ligament. The procedure allowed a dorsal approach, avoiding injury to the vertebral arteries and limited exposure, which are potential problems with hemilaminectomy of C1-C2. Further investigation is needed to evaluate long-term consequences of this procedure.     

百草枯引起胎鼠动脉管收缩与内皮素及其受体的关系研究

本文研究了百草枯对胎儿动脉管的毒性作用机理。取妊娠21d大鼠随机分成5组,在不同时间皮下注射25mg/kg百草枯,观察胎儿动脉管收缩情况;取妊娠21d大鼠随机分成4组,试验第1组母体皮下注射25mg/kg百草枯,第2组和第3组胎儿分别注射生理盐水和TAK-044后,母体皮下注射25mg/kg百草枯,观察胎儿动脉管收缩情况;用BQ-123代替TAK-044重复上述操作。结果表明:百草枯对妊娠末期胎儿动脉管具有毒性作用;由百草枯引起的胎儿动脉管收缩与ET有关,且以ETA受体作为媒介参与动脉管收缩。     

犬用盐酸特比萘芬喷雾剂处方筛选及含量测定研究

对犬用盐酸特比萘芬喷雾剂进行处方筛选并对盐酸特比萘芬进行含量测定。以喷雾剂成型性为指标优选出2%月桂氮卓酮(水溶性),0.35 g/L苯甲酸钠,10%KolliphorHS 15和适量高纯水制成水溶液。采用HPLC法测定该处方中有效成分盐酸特比萘芬的含量,结果显示盐酸特比萘芬在0.0201~0.4026 mg/m L的浓度范围内线性关系良好,回归方程为Y=2.652×107X-2.418×104(r=0.9998,n=6),平均回收率为104.14%,RSD为1.23%。通过采用HPLC法测量有效成分盐酸特比萘芬的含量稳定,所筛选的处方工艺可行,制备方法简单方便。     

除草剂敌草快所致的大鼠胎儿动脉管收缩与肾上腺皮质激素及其受体的关系

研究敌草快所致的大鼠胎儿动脉管收缩与肾上腺皮质激素及其受体的关系。①取妊娠19d大鼠20只，随机分为4组。试验1组未切除肾上腺，2、3组切除两侧肾上腺。1、3组皮下注射7mg／kg敌草使．2组和对照组皮下注射等量生理盐水。取出胎儿，冷冻后观察动脉管收缩情况。②在①里取出胎儿后，从各组母体的腹大动脉中采取血液，测定肾上腺皮质激素浓度。③在①里取出胎儿后，切断头部，收’集血液，测定肾上腺皮质激素的浓度。④取妊娠19、20、21d大鼠各20只，随机分成2组。试验组、对照组分别皮下注射40mg／kg肾上腺皮质激素和等量生理盐水，取出胎儿，冷冻后观察动脉管收缩情况。另用80mg／kg肾上腺皮质激素，重复上述操作。⑤取妊娠21d大鼠20只，收集120只胎儿动脉管，大动脉和母体肝脏，Western blotting法定量其组织液中蛋白质，并与标准肾上腺皮质激素受体蛋白（97000）对照比较。另取妊娠19、20、21d大鼠各20只，收集各自胎儿心脏及心血管系统，通过免疫组织学方法，观察胎儿动脉菅内皮中肾上腺皮质激素受体的分布情况。结果表明，敌草快能促进妊娠末期母鼠分泌大量肾上腺皮质激素；注射肾上腺皮质激素的胎儿动脉管内径明显小于对照组，且引起收缩的临界期为胎龄19～20d；妊娠20、21d胎儿动脉管内皮细胞中存在肾上腺皮质激素受体。由此可见，敌草快能促进肾上腺皮质激素的释放，肾上腺皮质激素对胎儿动脉管具有收缩作用。     

犬氧化损伤诱发白内障模型及其评价标准的研究

犬白内障是常见的眼科疾病,发病率高,严重影响犬的视力。有研究表明氧化损伤是重要的发病机制之一,目前对其疾病模型与发病机理研究较少。本研究旨在建立犬老年性白内障动物模型,为其后续机理研究奠定基础。本试验选取健康成年犬10只,随机选取6只为模型组,4只为对照组,用Fenton液造模。裂隙灯观察晶状体的混浊情况,光镜和透射电镜观察形态结构的变化,测定晶状体生化指标的改变,判定造模结果。与对照组相比,模型组晶状体混浊度变化明显,光镜和电镜下能观察到凋亡现象,T-SOD、GSH-Px和MDA值差异显著(P<0.05)。本试验证明用Fenton液囊袋内注射即可成功建立犬老年性白内障疾病模型。