Routine and specialized laboratory testing for the diagnosis of neuromuscular diseases in dogs and cats

Abstract: The diagnosis of neuromuscular diseases can be challenging. The first step is recognition that the disease involves the neuromuscular system (muscle, neuromuscular junction, peripheral nerve, and ventral horn cells of the spinal cord). Many neuromuscular diseases share clinical signs and cannot be distinguished based on clinical examination. Routine laboratory screening, including a CBC, biochemical profile, and urinalysis, can identify some of the most common systemic abnormalities that cause muscle weakness and myalgia, such as hypo‐ and hyperglycemia, electrolyte disorders, or thyroid abnormalities, and may suggest a specific diagnosis, such as diabetes mellitus, hypo‐ or hyperadrenocorticism, renal failure, or hypothyroidism. Increased creatine kinase activity, increased cardiac troponin I concentration, and myoglobinuria are useful in detecting skeletal and cardiac muscle damage. Identification of acetylcholine receptor antibodies is diagnostic for acquired myasthenia gravis. For primary muscle or peripheral nerve diseases, tissue biopsy is the most direct way to determine specific pathology, correctly classify the disease, and determine the course of additional laboratory testing. For example, inflammatory, necrotizing, dystrophic, metabolic, or congenital myopathies require different laboratory testing procedures for further characterization. Many neuromuscular diseases are inherited or breed‐associated, and DNA‐based tests may already be established or may be feasible to develop after the disorder has been accurately characterized. This review focuses on both routine and specialized laboratory testing necessary to reach a definitive diagnosis and determine an accurate prognosis for neuromuscular diseases.     

Disseminated mast cell tumor infiltrating the sphenoid bone and causing blindness in a dog

Mast cell tumors are found in most organs and tissues with variable biologic behavior in dogs. This case illustrates the clinical and magnetic resonance imaging (MRI) findings in a dog with disseminated mast cell tumor infiltrating the sphenoid bones. A 6‐year‐old male neutered Greyhound presented with a 3‐day history of acute onset of blindness. General physical examination was normal. Neurological examination revealed mildly disorientated mental status, absent menace response in both eyes, bilaterally decreased vestibulo–oculocephalic reflexes and absent direct and consensual pupillary light reflex in both eyes. An electroretinogram indicated normal retinal function in both eyes. A lesion involving the middle and rostral cranial fossa was suspected. Hematology and serum biochemistry were normal except decreased urea (1.2 mmol/L). MRI of the head revealed heterogeneous signal intensity of the sphenoid bones on T2‐weighted images and loss of their normal internal architecture. Cerebrospinal fluid analysis was normal. Abdominal ultrasound revealed hepatosplenomegaly and mesenteric lymphadenopathy. Fine needle aspirates were taken from the jejunal lymph nodes and the spleen. Results were consistent with disseminated mast cell tumor. The owner declined any treatment and the dog was euthanatized. Postmortem examination confirmed disseminated mast cell tumor affecting multiple organs, including the sphenoid bones. To our knowledge, this is the first case describing MRI features of disseminated mast cell tumor affecting the sphenoid bones and causing acute onset of blindness in a dog.     

Fiber‐optic spectrophotometry of cowpea nodules treated with nitrate or ammonium

Abstract

Cowpea nodules (Vigna unguiculata [L.] Walp. cv. CB5) were pierced with two opposing optical fibers (280 μm diameter), and absorbance spectra of 0.1 mm of nodule tissue were recorded from 415 to 600 nm using a modified spectrophotometer with a nodule sampling stage.

The nodule spectra exhibited two absorbance bands, a major band in the near‐UV (415–450 nm) and a lesser one in the green‐yellow region (510–585 nm); the latter exhibited a prominent peak at 550 nm. Nodule spectra were consistent with the superposition of the spectra of ferroleghemoglobin (Lb²⁺), oxyleghemoglobin (Lb²⁺‐ O₂), and cytochrome c (550 nm). The detection of leghemoglobin in vivo was confirmed by demonstrating the reversibility of binding of CO to Lb, and by comparing the spectra of live nodules with those obtained from anaerobic leghemoglobin preparations.

The effects on the nodule spectra of two successive applications (36 and 39 days after planting) of 5 and 10 mM NO₃ ^‐ or NH₄ ⁺ to the nutrient solution bathing the nodulated roots were determined. The spectra of NO₃ ^‐‐ and NH₄ ⁺‐treated nodules were indistinguishable; in each case the height of both the near‐UV and green‐yellow absorbance bands decreased with treatment. Treatment with N caused a significant reduction in the area of the green‐yellow absorbance band.

The spectra of green leghemoglobin pigments were obtained from senescent nodules; these exhibited a reduction in the height of the near‐UV absorbance band and a flattening of the green‐yellow band similar to that of nodules treated with N, but the broadening of the near‐UV band was greater in green nodules.     

双峰驼眼神经和上颌神经的研究

作者运用大体解剖学方法对双峰驼的眼神经和上颌神经进行了详细的解剖学研究。研究结果表明双峰驼的眼神经和上颌神经均起于三叉神经节,其中眼神经的分支有颧颞支、泪腺神经、额神经、额窦神经、肌支、鼻睫神经以及连于睫状神经节的交通支。鼻睫神经分为滑车下神经和筛神经。筛神经分为鼻内支和鼻外支。鼻睫神经有交通支连于睫状神经节。上颌神经分出颧面支、副颧面支、颧骨神经,鼻后神经、腭大神经、腭小神经和上齿槽后支,其主干延续为眶下神经。颧骨神经在眼眶后部分出。鼻后神经在翼腭窝内分为数支参与构成翼腭神经丛。腭大神经分出腭副神经以及进入鼻腔底壁的侧支。     

双峰驼面神经解剖

双峰驼的面神经在伸出茎乳突孔之前发出岩大神经、镫骨肌神经、鼓索和一加入岩小神经的交通支,并接受一条来自前庭耳蜗神经的交通支和迷走神经的耳支。面神经穿出茎乳突孔之后发出耳后神经、耳内支,腮腺支二腹肌支、颈支、耳睑神经,上颊支和下颊支。6/10例面神经发出一交通支连于舌咽神经。耳后神经与第一、第二颈神经之间不见有交通支。耳后神经和耳内支有侧支分布于腮腺和腮耳肌。上颊支在犬齿肌深面分为许多小支与眶下神经的分支形成一神经丛。下颊支在下颌骨的外侧面与颏副神经有较粗的交通支相连。     

The repair effects of Achyranthes bidentata extract on the crushed common peroneal nerve of rabbits

In this study the effect of the Achyranthes bidentata root aqueous extract on regeneration of the crushed common peroneal nerve in rabbits by using a combination of electrophysiological assessment and histological aspect were investigated. The examined functional and morphological parameters suggest that A. bidentata extract could accelerate peripheral nerve regeneration in a dose-dependent manner (10-20 microg/kg, i.v.).     

Persistent Bilateral Mydriasis Associated With a Pituitary Adenoma in a Horse

Severe bilateral mydriasis and bilaterally decreased vision were observed in a 23-year-old crossbred warmblood gelding with a history of pituitary pars intermedia dysfunction. Ten years after the onset of clinical signs, it was killed humanely because of worsening of clinical signs and loss of therapeutic responsiveness. Postmortem examination of the head was performed to confirm the suspected pituitary neoplasm and to investigate secondary oculomotor lesions. Pathomorphologic examination revealed an expansile space-occupying pituitary adenoma and degenerative changes in the preganglionic oculomotor nerve, ciliary ganglion, and optic chiasm. The ocular clinical findings share features of a cavernous sinus syndrome.     

鸡脑桥内神经核团的形态学研究

试验利用3只白来杭鸡脑制成的冰冻切片，经Nissl法染色，光镜观察分布于脑桥内的神经核团位置、形态及细胞组成。结果表明：中央上核位于中脑内；三叉神经运动核划分为内侧亚核和外侧亚核；三叉神经感觉主核前极在三叉神经运动核前极近平面；上橄榄核为一单一圆形核团；桥外侧核划分为两个亚核；首次观察到鸡脑桥中存在面神经副核；尾侧线形核、桥吻侧网状核、桥尾侧网状核、展神经核、耳蜗神经核、前庭神经核群等核团与前人观点一致。     

磁场对固定化乳酸脱氨酶催化活性的影响

采用流通池光纤荧光光度法，对固定化乳酸脱氢酶（ＬＤＨ）在静磁场作用下的催化活性进行了探讨．发现在０．０８４～０．２３０Ｔ磁场作用下ＬＤＨ的催化活性明显降低，其降低值随磁场强度增强而增大，且与磁场作用的时间和ｐＨ值有关，而在２５～４０℃范围内，温度则无显著影响。