Cystic cholangioma in the thoracic cavity of a rat

A female congenic rat produced by repeated backcrossing of Nihon rats, a model for hereditary renal cell carcinoma, to Brown Norway rats was necropsied at 24 months of age. At necropsy, a white mass about 1 centimeter in size was observed in the thoracic cavity, and the mass partly adhered to the esophagus and the diaphragm. Histologically, the mass was clearly circumscribed by connective tissue, and consisted of neoplastic cuboidal epithelial cells that showed cystic tubular proliferation. Some islands of well-differentiated hepatocytes and some vessels were observed in the mass. Immunohistochemically, the tumor cells were strongly positive for cytokeratin and partly positive for vimentin but were negative for mesothelin and Von Willebrand Factor. The positive rate for Ki-67 was 2.4%. Based on these histological and immunohistochemical evidences, we diagnosed this tumor as a cystic cholangioma that might have arisen from the ectopic hepatic tissue in the thoracic cavity.     

Partial ligation of the transposed parotid duct at the level of the parotid gland for excessive salivary secretions

Objective To determine the outcome and effect of a partial ligation of the transposed parotid duct at the level of the parotid gland in four dogs with excessive salivation and ocular irritation. Methods Four dogs were previously diagnosed with absolute keratoconjunctivitis sicca. After a parotid duct transposition (PDT) surgery, these dogs experienced excessive saliva production and abundant salivary precipitates, which resulted in epiphora, moist dermatitis, blepharospasm, and keratitis. In an effort to decrease saliva production, a partial ligation of the transposed duct at the level of the parotid gland was performed. Two or three accessory branches to the primary parotid duct were ligated at the level of the salivary gland. Results The four cases were three Yorkshire terriers and a Chihuahua. The average age of the four patients was 2.5 years. Partial ligation of accessory branches of the parotid duct at the level of the parotid gland after a PDT in this study demonstrated improved ocular comfort, decreased salivary precipitates, and adequate Schirmer tear test results without marked epiphora in three of the four animals. The male Yorkshire had epiphora after the initial partial ligations of two accessory branches were placed at the level of the parotid gland. To correct the excessive salivary flow, two additional ligatures were placed at a later date, which resolved the epiphora. Conclusion Partial ligation of the parotid duct at the level of the parotid gland proved to be an effective technique in moderating the salivation in these four patients with excessive salivary secretions after PDT.     

THE RADIOGRAPHIC APPEARANCE OF THE PULMONARY VASCULATURE IN THE CAT

The purpose of this study was to determine the dimensions of the pulmonary arteries and veins in the cat, both in normal animals and those with evidence of intrathoracic disease. The radiographs of 50 normal cats, 35 cats with hypertrophic cardiomyopathy (HCM), and 15 cats with other intrathoracic disease were assessed. The normal range for the right cranial lobar artery compared with the proximal third of the fourth rib was 0.5-1.0, with a mean artery-to-rib ratio of 0.70 (standard deviation +/- 0.13). Normal cats had a mean vein diameter of (0.20 +/- 0.03 cm) (P = 0.034) compared with cats with HCM, which had a significantly greater mean vein diameter (0.22 +/- 0.04 cm).     

ENDOSCOPIC RETROGRADE CHOLANGIO-PANCREATOGRAPHY IN HEALTHY BEAGLES

Endoscopic retrograde cholangiography and pancreatography was performed in seven healthy Beagles to assess the common bile duct and the accessory pancreatic duct after retrograde filling with an iodine contrast medium. All dogs had a major and a minor duodenal papilla. One Beagle had additionally an accessory papilla. The diameter of the contrast filled ducts was measured at three defined measure points (MP1-3) in ventrodorsal radiographs and left lateral radiographs. In ventrodorsal radiographs of endoscopic retrograde cholangiography the common bile duct had a straight craniomedial course. The mean duct diameter was from proximal to distal 3.04 +/- 1.89mm at MP1, 2.38 +/- 1.23 mm at MP2, and 2.11 +/- 0.84 mm at MP3. In ventrodorsal radiographs of endoscopic retrograde pancreatography, the left and right branch of the accessory pancreatic duct united in the pancreatic body. The mean diameter of the right branch was 0.88 +/- 0.14 mm at MP1, 0.72 +/- 0.2 mm at MP2 and 0.61 +/- 0.11 mm at MP3. The left branch had a diameter of 0.93 +/- 0.28 mm at MP1, 0.86 +/- 0.21 at MP2, and 0.6 +/- 0.07 mm at MP3. The mean length was 81.6 +/- 14.3 mm for the right and 107.0 +/- 24.9mm for the left branch. In left lateral radiographs of endoscopic retrograde pancreatography, it was not possible to differentiate the left from the right branch. Both branches ran nearly parallel and showed similar diameters but slight differences in length. The study proves that endosopic retrograde cholangio-pancreatography is possible in dogs. Radiographs taken from dogs in dorsal recumbency allow an objective assessment of the common bile duct and the accessory pancreatic duct.     

USE OF RADIOGRAPHY IN COMBINATION WITH COMPUTED TOMOGRAPHY FOR THE ASSESSMENT OF NONCARDIAC THORACIC DISEASE IN THE DOG AND CAT

Computed tomography (CT) of the thorax was performed in 28 dogs and five cats and findings were compared with previous thoracic radiographs. The sample population included all animals that had thoracic radiographs and a CT study within 5 days of each other, where the complete imaging studies were available for review. Thoracic radiographs were considered indeterminate in 31 patients and CT examinations were done to acquire additional information. The presence of additional information from CT relating to presence of pathology, location of pathology, extent of pathology, and involvement of mediastinal structures was recorded. Whether there was a change in diagnosis based on the CT findings was also recorded. In only 4/33 animals (all dogs) did CT fail to provide any new information for the parameters evaluated when compared with survey thoracic radiographs. Additional information about the pathology that was present was gained by CT in 5/5 cats and 21/ 28 dogs. New information on compartmental location of pathology was seen in 4/5 cats and 19/28 dogs. New information on pathology extent was noted in 5/5 cats and 20/28 dogs. Additional information regarding involvement of mediastinal structures was obtained in 2/5 cats and 10/28 dogs. A change in diagnosis was made in 3/5 cats and 13/28 dogs. In conclusion, CT is a valuable tool for evaluating intrathoracic disease. CT provides additional cross-sectional anatomic information that can aid in anatomic localization and evaluation of the extent of the pathology in question.     

旋转直扩张通道中柱状物的取向数值模拟

为了获得柱状物的轨迹和取向演变过程,对旋转直扩张通道中的柱状物悬浮流进行了数值模拟.采用Laplace方程生成通道的数值网格,使用有限体积法求解流场,然后采用Runge-Kutta法沿轨迹积分Jeffery方程来获得柱状物的取向演变.通过求解概率分布函数获得柱状物稳态取向分布.结果表明,流场的进口速度和柱状物所处的进口位置对于柱状物的取向演变具有重要影响,而通道的旋转速度和柱状物的初始取向对于柱状物的取向演变影响不大.当柱状物的长径比大于5时,取向分布对于长径比的变化不敏感;小于5时,长径比越小,柱状物旋转的速度越快,并且出现指向围绕流动方向振荡的情况越频繁.柱状物的取向总体上朝着流线方向,在壁面附近这一现象更为明显.结论对于含柱状物悬浮流泵送过程的研究具有参考价值.     

农用烟囱风机结构性能优化

针对农用烟囱风机流量小,能效比偏低的问题,采用数值模拟的方法,在节约投资成本的前提下,不改变烟囱风机的叶片造型,对其配套的风筒结构尺寸进行改型优化。利用试验测试原型风机的性能后,通过数值模拟方法,从烟囱风机的风筒内径d(用改型后风筒内径与原型风筒内径之比,即内径比k表示)、出口段扩散角度α和扩散深度l这3个方面进行单因素改型优化。在单因素优化基础上,采用正交优化方法综合以上3个因素,得到风筒正交优化设计参数。根据正交所得优化参数制备相应风筒样机,进行试验性能测试。结果表明:1)单因素优化模拟下,与原型风机相比,k=0.985时风量和能效比提高了4.7%和4.0%;α=28°时风量和能效比提高了4.7%和5.3%;l=250 mm时风量和能效比提高了1.8%和3.2%。2)多因素正交数值模拟下,与原型风机相比,k=0.988、α=28°、l=200 mm时风量和能效比提高了7.9%和8.1%;3)对优化风机进行测试,与原型风机相比,优化风机风量和能效比提高4.6%和4.5%。     

马尾松茎树脂道发育的组织化学研究

利用组织化学方法对马尾松茎树脂道发育过程中上皮细胞内淀粉粒和树脂滴的动态变化进行了研究。结果表明,在树脂道原始细胞阶段,原始细胞内所含的淀粉粒数量较少,体积较小,树脂滴的数量也少。在树脂道形成阶段,上皮细胞内所含淀粉粒数量增加,体积增大,而树脂滴的数量也逐渐增多。在树脂道成熟阶段,上皮细胞内所含的淀粉粒数量减少,体积也减少,而树脂滴的数量和体积均达到最大。淀粉粒和树脂滴具有密切的相互关系,淀粉粒可能为树脂滴的合成提供前体。