Distinctive histopathologic features of canine optic nerve hypoplasia and aplasia: a retrospective review of 13 cases

Canine optic nerve hypoplasia (ONH) and aplasia (ONA) are significant neuro-ophthalmologic disorders that have been reported in several species. The purpose of this study was to describe the distinctive histopathologic features of ONH and ONA in canine patients identified from a collection of 20 000 ocular submissions at the comparative ocular pathology laboratory of Wisconsin from 1989 to 2006. The following information about ONH and ONA cases was collected: signalment, and clinical and gross findings, including unilateral vs. bilateral involvement. Microscopic evaluation was performed, with attention to optic nerve malformation, retinal ganglion cell (RGC) and nerve fiber layer (NFL) loss, and retinal disorganization. The distribution of retinal vasculature was recorded and a search for unusual findings of ONH and ONA was performed. Information and histologic documentation was available for 13 cases. Eight cases of ONH and five cases of ONA were identified. The average group age was 20.2 months and 16.1 months, respectively. The most common breed was the Shih Tzu (3/13). ONH usually presented bilaterally (7/8); all ONA cases presented as a unilateral disease (5/5). The morphologic findings in the optic nerve (ON) in ONH included variable degrees of ON hypoplasia and gliosis, as well as ectopic vestigial ON remnants within orbital nerves and connective tissues. The NFL was detected in the majority of the ONH cases; however, RGCs were rare or absent. Mild retinal disorganization was seen occasionally. Most cases of ONH were associated with regional peripheral retinal blood vessel extension into the vitreous, leaving the peripheral retina avascular. In ONA cases the retinal blood vessels, NFL and RGCs were totally absent and retinal disorganization was severe. Distinctive microscopic features encountered in ONA included anterior segment dysgenesis in some cases. The retina in these cases was stretched across the posterior lens capsule, never making contact with the posterior pole of the globe. The current study reviews the human and veterinary literature pertaining to ONH and ONA, compares ONH and ONA in dogs, and presents related ophthalmic histopathologic findings that have not been reported previously.     

Description of a regional anaesthesia technique for the dorsal cranium in the dog: a cadaveric study

Objective

To identify landmarks and to describe a technique for nerve blockade of the dorsal cranium in dogs.

制作光盘数据库的几种方法

叙述了几种制作数据光盘的方法,它包括数据光盘的刻录,应用程序的安装程序setup．exe的制作,光盘自动启动程序的制作等。     

Extraction of cheek teeth using a lateral buccotomy approach in 114 horses (1999-2009)

Reason for performing the study: There are few published data regarding the success rates of cheek tooth (CT) removal by lateral buccotomy in the horse. Objectives: A retrospective study of 114 horses admitted to 2 private equine referral hospitals over a 10 year period (1999–2009), which underwent CT removal via a lateral buccotomy. Methods: Hospital records were analysed and details including case details, presenting complaint and results of all diagnostic tests and surgical reports were documented. Information obtained during post operative reassessment was also available for analysis. Long‐term follow‐up information (>2 months) was obtained for 112 horses. Results: Short‐term complications (<2 months) occurred in 24/77 horses (31%) undergoing exodontia of the maxillary CT and 10/37 horses (27%) involving mandibular CT, with the majority arising from partial wound dehiscence and infection following 16 extractions (47%). All healed well by second intention. Other complications included both temporary (n = 6) and permanent (n = 3) facial nerve paralysis, myositis (n = 4) and the inadvertent establishment of an oroantral fistula (n = 4). One myositis case was subjected to euthanasia 24 h post operatively. Five horses had persistent sinusitis following surgery due to dental remnants (n = 2) and excessive packing material (n = 1) found in the sinuses. No inciting cause could be found in the remaining 2 horses. One further horse suffered a fatal cardiac arrest at induction of anaesthesia. Of all horses, 92% operated on had returned to their previous level of work after >2 months with no complications. Conclusion: Horses with CT removal by a lateral buccotomy have a reasonable prognosis for long‐term outcome. Potential relevance: Performing a lateral buccotomy is a justified treatment alternative for the surgical removal of equine CT following unsuccessful attempts by standing oral extraction, offering advantages over alternatives such as retropulsion, endodontic therapy and periapical curettage.     

神经-体液对家兔颈动脉窦压力感受性反射的试验性研究

试验在氨基甲酸乙酯麻醉的家兔上进行 ,观察乙酰胆碱与肾上腺素对颈动脉窦压力感受器反射的影响。结果如下 :①以不同浓度的乙酰胆碱灌流家兔颈动脉窦区时 ,压力感受器机能曲线向左下方移位 ,曲线最大斜率 (PS)、反射性血压下降幅度 (RD)、阈压 (TP)、平衡压 (EP)和饱和压 (SP )均呈明显的剂量依赖性 ;②肾上腺素的作用则相反 ;③再以电刺激分别刺激减压神经、减压神经中枢端、迷走神经及迷走神经外周端 ,记录其血压、心率和功率谱密度 (PSD)后加以分析。观察到电刺激减压神经使PSD高频率成分 (HF )变化不大 ,其余低频成分 (LF )、极低频成分 (VLF)及总变异 (TV)增大 (P <0 0 5)。还观察到电刺激迷走神经后对心率变异性 (HRV)的影响 ,以及对HF、LF、VLF及TV的增大显著 (P <0 0 5)。     

The use of electrical stimulation to guide epidural and intrathecal needle advancement at the L5‐L6 intervertebral space in dogs

ObjectiveTo determine the minimal electrical threshold (MET) necessary to elicit appropriate muscle contraction when the tip of an insulated needle is positioned epidurally or intrathecally at the L_5-6 intervertebral space (phase-I) and to determine whether the application of a fixed electrical current during its advancement could indicate needle entry into the intrathecal space (phase-II) in dogs.Study designProspective, blinded study.AnimalsThirteen (phase-I) and seventeen (phase-II) dogs, scheduled for a surgical procedure where L_5-6 intrathecal administration was indicated.MethodsUnder general anesthesia, an insulated needle was first inserted into the L_5-6 epidural space and secondly into the intrathecal space and the MET necessary to obtain a muscular contraction of the pelvic limb or tail at each site was determined (phase-I). Under similar conditions, in dogs of phase-II an insulated needle was inserted through the L_5-6 intervertebral space guided by the use of a fixed electrical current (0.8 mA) until muscular contraction of the pelvic limb or tail was obtained. Intrathecal needle placement was confirmed by either free flow of cerebrospinal fluid (CSF) or myelography.ResultsThe current required to elicit a motor response was significantly lower (p < 0.0001) when the tip of the needle was in the intrathecal space (0.48 ± 0.10 mA) than when it was located epidurally (2.56 ± 0.57). The use of a fixed electrical stimulation current of 0.8 mA resulted in correct prediction of intrathecal injection, corroborated by either free flow of CSF (n = 12) or iohexol distribution pattern (n = 5), in 100% of the cases.Conclusion and clinical relevanceNerve stimulation may be employed as a tool to distinguish epidural from intrathecal insulated needle position at the L_5-6 intervertebral space in dogs. This study demonstrates the feasibility of using an electrical stimulation test to confirm intrathecal needle position in dogs.     

MicroPNA-21 promotes proliferation of rat Schwann cells following nerve injury

AIM: To investigate the molecular mechanism of microRNA-21 (miR-21) in the regulation of Schwann cell proliferation following nerve injury. METHODS: The expression of miR-2l was detected by real-time PCR. Synthetic miR-21 mimic and its control were transfected into rat Schwann cells. CCK-8 assay was performed to evaluate the influence of miR-21 on the proliferation of Schwann cells. The cell cycle distribution was determined by flow cytometry. The expression of transforming growth factor β-induced protein (TGFBI) and cyclin D1 were detected by Western blotting. RESULTS: The expression of miR-21 in model group was 7.87±0.75 and 7.75±0.80 times higher than that in sham operation group and blank group respectively. After transfected with miR-21 mimic, the expression of miR-21 in experimental group was 2.21±0.14 and 2.29±0.21 times higher than that in negative control group and blank group respectively. Moreover, the A₄₅₀ value of CCK-8 assay in experimental group at 48 h was higher than that in negative control group and blank group. The proliferation index in experimental group was higher than that in negative control group and blank group. At the same time, the expression of TGFBI obviously decreased and the cyclin D1 increased in the Schwann cells 48 h after transfection with miR-21. CONCLUSION: miR-21 promotes the proliferation activity of Schwann cells by down-regulating TGFBI expression.