Chromosome instability in a calf with amelia of thoracic limbs

We report here on a case of a Holstein-Friesian male calf with the congenital total absence of thoracic limbs (amelia). Cytogenetic study showed a high rate of chromosome instability, represented by chromosome or chromatid breaks and gaps in 46% of the analyzed metaphase spreads. Moreover, 12% of the spreads appeared to be polypolid. The number of micronuclei also was significantly higher when compared to control animals. This paper discusses the association between chromosome instability and limb malformation.     

Anterior chamber-associated immune deviation.

The eye possesses a critical method of self-preservation in response to intraocular antigen presentation. Instead of conventional immunity by means of delayed-type hypersensitivity (DTH), the eye participates in a systemic immune response involving the thymus and spleen, ultimately leading to suppression of cell-mediated (T helper 1) immunity. The immune response begins with intraocular capture of antigen by specialized ocular antigen-presenting cells (APCs). These activated APCs then migrate preferentially to the marginal zone of the spleen, where they become part of an intricate and highly specific cluster of immune cells. The end result is the emergence of a population of antigen-specific T-regulatory lymphocytes that return to the eye and suppress DTH.     

Anterior uveal spindle cell tumor in a cat

Purpose To describe a case of anterior uveal spindle cell tumor in a cat with features similar to spindle cell tumor of blue eyed dogs. Methods A 10‐year‐old female spayed domestic short‐haired cat was referred for an iris mass OS. The mass was solitary, nodular, nonpigmented, located medially, and causing dyscoria. A diagnosis of a benign epithelial tumor was suggested by a FNA of the mass. The cat was lost to follow‐up for 2 years, after which time she re‐presented with glaucoma, blindness and grossly evident iridal mass enlargement OS. Transconjunctival enucleation was performed and the globe submitted for histopathology. Results Histopathology of the enucleated globe revealed the superior iris to be infiltrated and effaced by a large population of neoplastic spindle cells. The cells were arranged in streams and bundles and exhibited Antoni‐A and Antoni‐B tissue patterns, which are characteristic of Schwann cell tumors. Mitotic figures were rare and cellular pleomorphism moderate. Immunohistochemical staining was positive for S‐100 protein and glial fibrillary acidic protein (GFAP), and negative for Melan‐A. Interestingly, there was no histological evidence of glaucoma. Conclusions Based on its histopathologic characteristics, this iris tumor was diagnosed as a Schwann cell variant of a peripheral nerve sheath tumor (PNST) closely resembling the spindle cell tumor of blue‐eyed dogs. Anterior uveal PNST has not been previously reported in cats to the authors’ knowledge. The presence of Antoni type A and type B tissue patterns along with immunohistochemical staining may facilitate a diagnosis of PNST and rule out malignant melanoma.     

Replacement of the Anterior Cruciate Ligament in the Dog

Abstract—A method using the central one third of the patellar ligament, a full-length strip of the superficial one-half of the patella and a full thickness strip of the quadriceps tendon was used as a replacement for the anterior cruciate ligament in nine experimental dogs and four clinical cases. The pathology and histological picture of the stifle joints in the experimental dogs are described. The results are encouraging. Sammendrag—Det beskrives en ny metode til å erstatte et overrevet ligamentum cruciatum anterius i kneleddet hos hund. En bruker den midterste tredjedelen av ligamentum-patella i hele dets tykkelse, et tilsvarende bredt stykke av ytterste halvpart av patella og et tilsvarende bredt stykke av senen til musculus quadriceps femoris fra dew tilheftning proksimalt pB patella. Operasjonsmetoden er brukt på ni forsökshunder og fire kliniske tilfelle av ligamentruptur. På forsökshundene ble kneleddene undersökt makro og mikroskopisk etter avlivningen. Resultatet etter operasjonene var oppmuntrende. Résumé—Une méthode comportant l'utilisation du centre tiers du ligament rotulien, toute une longueur de la moitié superficielle de la rotule ainsi que toute une épaisseur du tendon quadriceps a été appliquée pour remplacer le ligament cruciforme antérieur chez neuf chiens d'expérience et quatre cas cliniques. La pathologie et l'image histologique des grassets chez les chiens d'expérience furent décrites, et les résultats en furent encourageants. Zusammenfassung—Eine Methode, die das zentrale Drittel des Ligamentum patellae, einen Streifen in voller Länge der oberflachlichen Hälfte der Patella und einen Streifen der ganzen Dicke der Sehne des Quadriceps benutzt, wurde als Ersatz für das Ligamentum cruciatum in 9 Experiment Hunden und 4 klinischen Fallen angewandt. Die Pathologie und Histologie der Kniegelenke der Experiment Hunde wurden beschrieben. Die Resultate waren ermutigend.     

Development of the Mouse Anterior Commissure: Part II: A Comparison of Glial Differentiation in the Anterior and Posterior Limbs of the Anterior Commissure of the Mouse Brain during Myelination using Semithin Light Microscopic Sections

The percentage of glioblasts, oligodendrocytes, astrocytes and microglia in the anterior and posterior limbs of the mouse anterior commissure during myelination was estimated from semithin, toluidine blue stained sections using the criteria of LING et al. (1973). From 11 to 25 days glial differentiation was more advanced in the anterior limb, but from 35 days the percentage of each type of glial cell was similar in each limb. The percentage of microglia was similar in each type of glial cell was similar in each limb. The percentage of microglia was similar in each limb and remained constant from 11 to 240 days. The percentage of astrocytes was similar in each limb at each age, but increased from 10% at 11 days to 20% at 35 days, when it became constant. The percentage of oligodendrocytes was higher in the anterior limb from 11 to 24 days, and continued to increase in both limbs up to 240 dyas. The precentage of dark oligodendrocytes increased with age, while the percentage of light and medium oligodendrocytes declined. Oligodendrocyte differentiation corresponded closely with myelination in each limb.     

双峰驼乳前齿的形态学研究

以14峰双峰驼头骨为研究对象,通过观察、测量和拍照,研究了双峰驼乳前齿的形态结构。拔出的乳齿用游标卡尺测量各个参数,进行统计学处理。结果表明:双峰驼乳前齿共有12枚,包括上乳切齿1对,上乳犬齿1对,下乳切齿3对,下乳犬齿1对。上乳切齿牙体最小,牙冠呈柱状,功能退化。下乳切齿牙冠呈铲状,切嵴锋利,单齿根长而尖,易铲起植被而取食。上乳犬齿牙冠呈较扁平的锥状,冠短根长,牙尖不显著,犬齿功能退化。下乳犬齿形态特征与下乳切齿相似,主要是铲切食物。双峰驼乳前齿的典型形态学特点与其取食多刺粗糙的旱生植物相适应。