COMPUTED TOMOGRAPHY OF NECROTIZING MENINGOENCEPHALITIS IN 3 YORKSHIRE TERRIERS

A necrotizing meningoencephalitis of Yorkshire terriers has recently been reported in 6 dogs in Switzerland, 1 dog in Japan and 1 dog in the United States. The purpose of this report is to describe the computed tomographic (CT) findings in 3 dogs with this disease, and to correlate the CT abnormalities with the clinical and pathologic findings in each case. Three Yorkshire Terriers between 2 and 10 years old were evaluated. Physical and neurologic examinations, complete blood count (CBC), serum biochemistry profile, cerebrospinal fluid analysis, and CT scan were performed on all 3 dogs. Brainstem auditory evoked responses (BAER) were evaluated for 2 dogs. Two dogs were euthanized at the owners' request and necropsies were performed. Neurologic examination findings were consistent with a multifocal/diffuse encephalitis involving the cerebrum and brainstem in all 3 dogs. Complete blood count and biochemistry profiles were normal. Elevated protein concentration and a mononuclear pleocytosis were demonstrated in 2 of 3 dogs on cerebrospinal fluid evaluation. Multifocal, extensive areas of decreased opacity throughout the cerebral hemispheres, asymmetric ventriculomegaly, and lack of contrast enhancement were appreciated on CT images of all three dogs. No mass effect was seen. These findings correlated well with pathologic findings at necropsy, which included multiple malacic cavitations within the brain, representing areas of locally extensive necrosis. CT abnormalities in combination with signalment, clinical findings and cerebrospinal fluid analysis should facilitate a presumptive diagnosis of Yorkshire Terrier necrotizing meningoencephalitis.     

POSITRON EMISSION TOMOGRAPHY FEATURES OF CANINE NECROTIZING MENINGOENCEPHALITIS

A Yorkshire terrier and a Chihuahua were referred for acute onset, generalized tonic‐clonic seizures and were suspected to have meningoencephalitis based on magnetic resonance (MR) imaging findings. Brain lesions appeared hyperintense with T2‐weighted imaging and hypointense with T1‐weighted imaging, and were characteristic of necrotizing meningoencephalitis. Both dogs were diagnosed with necrotizing meningoencephalitis based on pathologic findings. Fluorine‐18 fluorodeoxyglucose positron emission tomography (FDG‐PET) was performed on both animals before euthanasia with the permission of the owner. In FDG‐PET images, these lesions seen in MR images were characterized by multifocal or diffuse hypometabolism. Our FDG‐PET results provided evidence of glucose hypometabolism in areas of necrosis and cavitation associated with necrotizing meningoencephalitis. FDG‐PET has the potential to provide valuable diagnostic information in dogs with suspected necrotizing encephalitis.     

RETROSPECTIVE STUDY EVALUATING ASSOCIATIONS BETWEEN MIDLINE BRAIN SHIFT ON MAGNETIC RESONANCE IMAGING AND SURVIVAL IN DOGS DIAGNOSED WITH MENINGOENCEPHALITIS OF UNKNOWN ETIOLOGY

Difficulty has been encountered when trying to identify ante mortem prognostic indicators for dogs with meningoencephalitis of unknown etiology (MUE). Identifying MRI imaging parameters associated with prognosis may impact treatment decision‐making for clinician and owner. Our hypotheses for this retrospective cohort study are that dogs diagnosed with MUE that had midline shift on brain MRI would have a poorer survival compared to dogs without midline shift; and that younger age, lower weight, and low cerebrospinal fluid (CSF) cell count would be correlated with improved survival. Medical records were reviewed from two institutions. Inclusion criteria included: clinical signs referable to intracranial disease, brain MRI at presentation, abnormal CSF analysis, and negative infectious disease testing. Magnetic resonance imaging scans were evaluated for midline shift using the T2‐weighted transverse image at the interthalamic adhesion and at the site of maximal deviation. Fifty‐two dogs met the inclusion criteria. Median midline deviation was 0.12 cm. Median survival for dogs with no shift was 906 days and with shift was 84 days. Survival was not significantly different between groups (P = 0.11). This remained true when correcting for age (P = 0.22) and CSF TNCC (total nucleated cell count) (P = 0.12). Age at the time of diagnosis (P = 0.02) and CSF TNCC (P = 0.03) were significantly associated with survival. Cerebrospinal fluid protein value (P = 0.84) and weight (P = 0.82) were not significantly associated with survival. In this study of 52 dogs with MUE, MRI evidence of midline brain shift between 0.04 and 0.3 cm at the level of the interthalamic adhesion was not associated with shorter survival.     

IMAGING DIAGNOSIS—MENINGOENCEPHALITIS SECONDARY TO SUPPURATIVE RHINITIS AND MENINGOENCEPHALOCELE INFECTION IN A DOG

Nasal encephaloceles (meningoceles or meningoencephaloceles) are rare and not reported to be infected or coupled with a facial deformity in dogs. This report describes an older dog with acute worsening of seizures due to suppurative meningoencephalitis with coexisting suppurative rhinitis and infection of a meningoencephalocele. Additionally, the dog had a facial deformity for at least 5 years. The results of necropsy, computed tomography, and postmortem magnetic resonance imaging are compared. The development of nasal encephaloceles is discussed, including the potential role of early trauma, and whether separation of neural ectoderm from the surface ectoderm is part of the pathogenesis.     

MAGNETIC RESONANCE IMAGING IN THE DIAGNOSIS OF FOCAL GRANULOMATOUS MENINGOENCEPHALITIS IN TWO DOGS

Two dogs with neurologic signs were evaluated by magnetic resonance imaging of the brain. Focal space-occupying lesions were present in both dogs. In the first, the lesion was in the brain stem and in the second, in the cerebellum. In one dog the lesion was only evident after administration of gadolinium-DTPA-dimeglumine. Based on the magnetic resonance images, neoplasia was suspected in both dogs but histopathologically, granulomatous meningoencephalomyelitis was diagnosed.     

A COMPARISON OF ECHOCARDIOGRAPHIC INDICES OF THE NONRACING, HEALTHY GREYHOUND TO REFERENCE VALUES FROM OTHER BREEDS

Echocardiographic evaluation of healthy, nonexercising, awake greyhounds revealed substantial differences in left ventricular cavity dimensions, wall thickness, systolic time intervals and fractional shortening as compared to previously reported normal echocardiographic values obtained from mongrels and various other dog breeds. Despite corrections for body surface area and body weight, these differences remained, suggesting that breed and body conformation should be considered when interpreting echocardiographic studies in the dog.     

NON-SKELETAL DISTRIBUTION OF BONE-SEEKING RADIOPHARMACEUTICALS

A variety of factors may change the normal distribution of bone-seeking radiopharmaceuticals. This paper presents a classification of non-skeletal bone tracer distribution according to physiologic, pathologic, and artifactual causes. The mechanisms thought to account for non-skeletal distribution are reviewed. Examples of non-skeletal bone tracer distribution include calcinosis cutis and pulmonary mineralization in hyperadrenocorticism, renal infarct, acute rhabdomyolysis, urine contamination, lymph node uptake following extravasation of the radiopharmaceutical, thyroid uptake due to free pertechnetate in the injectate, and intramuscular uptake following injection of butorphanol.     

LOW-FIELD MAGNETIC RESONANCE IMAGING OF A PYOCEPHALUS AND A SUSPECTED BRAIN ABSCESS IN A GERMAN SHEPHERD DOG

Magnetic resonance imaging was performed on an eight-year-old, neutered female German Shepherd dog with a history of acute depression, inappetence, and hyperthermia. A lesion in the cerebrum was suspected. Possible differential diagnoses were meningoencephalitis, neoplasia, and vascular lesion (infarction, bleeding). A ring enhancing lesion was found in the basal ganglia on the left side with edema of the surrounding brain tissue. A similar mass lesion was present in the right pterygoid musculature. With inversion recovery sequences an altered composition of the cerebrospinal fluid (CSF) in the left lateral ventricle could be detected. CSF analysis confirmed a pyocephalus, probably due to rupture of a brain abscess into the left lateral ventricle.     

奶牛精子表面电位的群体分布

应用细胞电泳方法,测量了不同电压下奶牛精子的电泳速度,绘制了两类精子在不同电压下的泳动速度分布图,计算了两类精子在磷酸缓冲液中的平均zeta电位,其中X精子为-27.9mV,Y精子为-22.4mV。     

中泰大学生英文E-mail写作独特词汇的对比研究

定量和定性地剖析了中泰两所大学学生的英文E—mail写作独特词汇，即两校学生没有相互共用的词汇。结果表明，华南农业大学（简称华农大）的学生在使用独特词汇的“质”和“量”上都比泰国宋卡王子大学（简称王子大学）学生要强。认知词汇量相同的情况下，华农大学生使用了594词族而王子大学没有使用的词汇，王子大学只使用了302词族华农大没有使用的词汇。定语从句的连词“which”，虽在华农大的文章平均每篇出现1．2次，并未在王子大学的写作出现；华农大学生使用了更多语义上相近的词，如：“if”和“whether”、“but”和“althoush，thoush，however”及“what”和“whatever”。独特词汇主要受两国文化和地理位置及学生使用词汇能力的影响。     

青海天然草地分布规律初探

青海天然草地在发育形成上表现出其特殊的类型和分布规律。在北半部（不包括祁连山地）表现为径向的水平分布规律。从湟水流域向西,地势逐步抬升,经青海湖盆地、共和盆地,到柴达木盆地,天然草地由温性草原逐渐向温性荒漠过渡。在青南高原面上由东南向西北,草地类型大体出现山地疏林草甸→高寒疏灌草甸→高寒（嵩草）草甸→高寒（针茅）草原的...     

都兰县低产草地分布、成因及治理措施

通过对都兰县低产草地调查及成因分析,结果表明全县低产草地面积为99.13×104hm2.其成因主要是水、热和土壤条件不协调人为干扰过度;鼠虫害严重等.综合治理措施是加强围栏保护;实施人工种草和减轻天然草地放牧压力.     

循化县植被类型及分布

根据遥感影像TM数据信息及其文献资料,结合野外验证研究循化县植被类型及其分布。结果表明循化县共有森林、灌丛、草原、荒漠、草甸5个植被型组,20个植被群系;并且植被垂直分布明显。     

青海省温性草原类草地的分布特征

以青海省境内广泛分布的温性草原类草地为研究对象,初步探讨了该类草地区域分布规律及植被结构特点。认为温性草原类是青海省天然草地垂直带谱的基带草地,其分布范围东西跨越5个经度带,南北约跨越1个纬度带。分布地区海拔高度一般在1700~3500m,但在柴达木盆地及青南高原区海拔可上升至3900~4400m。草地植被组成每平方米牧草种类约为10~17种,以旱生丛生禾草西北针茅、疏花针茅、长芒草、芨芨草、青海固沙草等为优势种。由于受人类活动影响较强,在利用上要做到保护和利用、建设和发展并举,实现可持续发展。     

放牧对松嫩平原羊草草地植物种群分布的影响

放牧对羊草草地植被及其土壤环境的影响是放牧演替系列上植物种群规律分布的重要原因。本文从由放牧引起的植被及主要土壤因子变化梯度入手,研究羊草、五脉山黧豆、寸草苔等8种主要植物在放牧衰退演替系列上的分布规律、生态位重叠及主要土壤因子变化对其分布的影响。     

日本血吸虫虫卵在BALB/c鼠肝脏各叶中的分布调查

为建立血吸虫虫卵计数的可准确量化和易于操控的小鼠肝脏取样方法,用日本血吸虫人工感染BALB/c系小鼠42 d后,将肝脏分成左叶、中央叶、右叶,分别进行日本血吸虫虫卵计数。结果显示,感染日本血吸虫42 d的BALB/c小鼠肝脏的平均重量为（2.23±0.26）g。左叶、中央叶、右叶和全肝的每克肝脏含卵数（EPG）分别为49.80×103±26.70×103,59.03×103±29.04×103、36.55×103±17.77×103和47.78×103±23.64×103。各肝叶之间差异有统计学意义（P〈0.05）。可见,血吸虫虫卵在肝脏各叶中的分布是不均匀的,以肝中央叶为最多,肝右叶最少。肝脏EPG与各肝叶中EPG符合线性关系,每对配对成虫对肝脏EGP的贡献从3.67×103到6.5×103个虫卵不等。     

USE OF PHOTON FIELDS WITH NONCOINCIDENT ISOCENTERS TO IMPROVE HOMOGENEITY OF DOSE DISTRIBUTION

To compare changes in dose distribution in irregularly shaped volumes treated using fields with noncoincident isocenters compared with fields with coincident isocenters. The hypothesis was that use of fields with noncoincident isocenters would result in improved homogeneity of dose distribution. We chose to test the hypothesis in canine nasal tumors because of the increased dorsoventral thickness of the caudal compared with the rostral nasal cavity. Computed tomography images from eight dogs with nasal tumors were selected. A tissue-contouring program was used to outline contours, including the mandible as a normal tissue structure and the planning target volume (PTV), divided into a rostral and caudal volume. A traditional computerized treatment plan consisting of two parallel-opposed fields was constructed for each dog. A second treatment plan using a third caudally located field having a different isocenter was constructed for comparison. Dose-volume histograms were generated and compared for each contoured structure in both plans. In all dogs the use of noncoincident fields resulted in increased dose to the ethmoid region through the caudal field. Minimum dose in the caudal tumor PTV increased as well. At the same time, dose delivered to the mandible, prone to develop significant side effects, was lower in all dogs with the use of noncoincident fields, as it was possible to reduce the dose delivered from the ventral field. Use of photon fields with noncoincident isocenters can improve the dose distribution in irregularly shaped volumes in comparison with fields with coincident isocenters. Improved tumor dose distribution was achieved with the addition of a smaller field having a different isocenter.     

卫氏与斯氏并殖吸虫在实验动物体内分布的比较观察

目的 比较两种主要对人体致病的肺吸虫在实验动物肺内与肺外（胸、腹腔）的分布，为临床诊断及药物治疗提供参考。方法 粪检肺吸虫卵阴性的猫犬分别经口感染卫氏并殖吸虫（P．W）与斯氏并殖吸虫（P．S）囊蚴，饲养3个月后粪检肺吸虫卵阳性时对犬、猫进行解剖，观察与统计内肺外虫数。结果 猫犬解剖所获得P．W与P．S成虫均以左、右肺下叶寄生成虫数最多，猫、犬感染P．W后检获肺外期与左、右肺的童虫数均无显著性差异（P〉0．05）。猫感染P．S后所检获肺外期童虫数与左、右肺的童虫数有显著性差异（P〈0．05），而犬感染P．S所检获肺外期童虫数与左、右肺的童虫数有高度显著性差异（P〈0．01）。猫感染P．W与P．S囊蚴后虫体平均回收率为41．84％，39．85％；犬感染P．w与P．S囊蚴后虫体平均回收率分别为47．44％，24．57％。经统计学处理猫感染两种虫体回收率显著高于犬（P〈0．05）。结论 两种肺吸虫在实验动物犬、猫肺部的分布均以左、右肺下叶寄生成虫数最多，猫犬感染P．S所检获的肺外期童虫数与检获左、右肺内的童虫数分别为有显著性差异（P〈0．05）与高度显著性差异（P〈0．01），猫感染虫体的回收率明显高于犬。     

桑虎天牛幼虫空间分布型的研究

测定了虎天牛幼虫空间分布型及聚集指标,得知虎天牛幼虫空间分布符合负二项分布,少数也符合奈曼分布,且虎天牛幼虫属聚集分布,引起聚集的原因与环境因素有关。