Gastrointestinal stromal tumors and leiomyomas in the dog: a histopathologic,immunohistochemical, and molecular genetic study of 50 cases

Fifty canine gastrointestinal (GI) mesenchymal tumors were examined to determine the occurrence of leiomyomas (LM) and GI stromal tumors and to compare their clinicopathologic features. Twenty-one tumors (42%) were histologically reclassified as gastrointestinal stromal tumors (GISTs) and 29 tumors (58%) as LMs on the basis of their histologic similarity with homologous human tumors. The GISTs occurred equally in males and females, with a mean age of 11 years (range 5-14 years). Five GISTs (24%) were associated with clinical signs and six (29%) had metastasis in liver or abdominal cavity. The GISTs occurred in large intestine (10, 48%), small bowel (six, 29%), stomach (four, 19%), and mesentery of small intestine (one, 5%). Histologically, they were highly cellular spindle, or less commonly epithelioid tumors with mitotic rates ranging from 0 to 19 per 10 HPF. Eleven tumors (52%) were positive for CD117 (KIT); seven (33%) were positive for smooth muscle actin but none for desmin and S-100 protein. Sequences of KIT exon 11, often mutated in human GISTs, were evaluated from four GISTs. Deletion of Try556-Lys557 coexisting with duplication of Gln555 in one case of GIST and T to C transition resulting in substitution of Pro for Leu575 in another were identified. The LMs occurred predominantly in males (82%) with a mean age of 11 years (range 8-17 years). Nine tumors (31%) had associated clinical signs. They occurred in the stomach (22, 76%), esophagus (four, 14%), and intestines (three, 10%); all were paucicellular, had no mitoses, and were composed of mature smooth muscle cells. Twenty-eight (97%) were positive for smooth muscle actin and 18 (62%) for desmin but none for CD117 and S-100. Both GISTs and true LMs occur in the GI tract of dogs. Both tumors have distinctive pathologic features.     

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.     

Epidemiological and genetical differences between classical and atypical scrapie cases

The aim of this study was to analyze the epidemiology and prion protein (PrP) genetics in scrapie-affected sheep flocks in Germany. For this purpose, 224 German scrapie cases in sheep diagnosed between January 2002 and February 2006 were classified as classical or atypical scrapie and the amino acids at codons 136, 141, 154 and 171 were determined. Likewise, representative numbers of flock mates were genotyped. Significant epidemiological differences were observed between classical and atypical scrapie cases in regard to the numbers of scrapie-affected sheep within a flock, the sizes of flocks with only a single scrapie-positive sheep or more than one scrapie-positive sheep and the age distribution of the scrapie-positive sheep. Sheep with the ARQ/ARQ genotype had by far the highest risk for acquiring classical scrapie, but the risk for atypical scrapie was the highest for sheep carrying phenylalanine (F) at position 141 (AF(141)RQ) and/or the AHQ haplotype. However, atypical scrapie also occurred with a notable frequency in sheep with the PrP haplotypes ARR and/or ARQ in combination with Leucine at position 141 (AL(141)RQ). Furthermore, six atypical scrapie-positive sheep carried the PrP genotype ARR/ARR. The high proportion of sheep flocks affected by atypical scrapie underscores the importance of this scrapie type.     

Diagnosis of preclinical scrapie in live sheep by the immunohistochemical examination of rectal biopsies

In most sheep infected with a transmissible spongiform encephalopathy (tse) the disease-associated prion protein (PrP(d)) accumulates in tissues of the lymphoreticular system, suggesting that it might be detected in biopsy specimens. A procedure has been developed to obtain biopsy specimens of rectal mucosa in which PrP(d) has been detected by immunohistochemistry in preclinically infected sheep of all susceptible PrP genotypes. It is probable that PrP(d) increases with the age of sheep or period of incubation. PrP(d) was detectable approximately halfway through the incubation period, with sheep of some PrP genotypes showing positive results earlier than others. For a preclinical diagnosis, the risk of a false negative result was approximately 9 per cent for samples containing 10 follicles, a figure that was reached in 87 per cent of the biopsies. The rectal biopsies had the same sensitivity and time of onset of PrP(d) accumulation as biopsies of the palatine tonsil, but provided larger numbers of follicles. The procedure is simple and quick, does not require dedicated specific instruments, sedation or general anaesthesia, and can be performed repeatedly on the same sheep without detrimental effects to either the animal or the number of follicles obtained.     

Pleural endometriosis in an aged rhesus macaque (Macaca mulatta): a histopathologic and immunohistochemical study

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity and is one of the most common reproductive abnormalities encountered in women as well as Old World primates. The majority of endometriosis cases in Old World primates occur within the abdominal cavity, with spread to extraabdominal sites considered to be a rare event. A 19-year-old multiparous female rhesus macaque (Macaca mulatta) presented to necropsy for difficulty breathing and weight loss. Grossly, the animal had marked abdominal endometriosis and severe hemoabdomen and hemothorax, the latter of which was accompanied by marked pleural fibrosis. Histologic examination confirmed the abdominal endometriosis and also revealed numerous uterine glands and stroma embedded within the pleural fibrosis. Rafts of endometrial tissue were present within pulmonary lymphatics and the tracheobronchial lymph nodes. Immunohistochemically, all ectopic endometrial tissue had varying degrees of positive immunoreactivity to cytokeratin, vimentin, progesterone and estrogen receptors, and calretinin but was negative for desmin and carcinoembryonic antigen. Pleural endometriosis is an extremely rare manifestation of endometriosis in nonhuman primates. This case report emphasizes lymphatic spread as a likely mechanism for extrauterine endometriosis.     

山羊IL-2的体外表达及其多克隆抗血清的制备

应用RT-PCR方法从山羊外周血淋巴细胞中克隆了山羊白细胞介素-2(Caprine interleukin-2,CapIL-2)基因并进行测序,将编码山羊IL-2蛋白的基因亚克隆至pET30a( )上,转化大肠杆菌BL21(DE3)并用IPTG于37℃诱导培养。表达融合蛋白通过ProBondTM蛋白纯化试剂盒纯化。纯化产物经3次免疫新西兰白兔,制备出山羊IL-2抗血清。本次试验成功地表达、纯化了山羊IL-2,并制备出兔抗山羊IL-2抗血清,为下一步开展山羊IL-2重组蛋白的应用研究奠定了基础。     

Intussusception in dogs and cats: A review of 36 cases

Intussusception is recognized as a common cause of bowel obstruction in small animals. This study documents the clinical and surgical findings in nine cats and 27 dogs diagnosed as having intussusception. The main purposes of the study were to define the predisposing causes and clinical signs of intussusception and to evaluate various surgical techniques commonly employed in its treatment. No common predisposing cause could be established. Diagnosis of intussusception was based most often on clinical signs of bowel obstruction in association with the palpable abdominal mass. The majority of the intussusceptions involved the enterocolic junction. Formation of adhesions was more frequent in cats. Surgical treatments included simple reduction, manual reduction with plication, intestinal resection/anastomosis, and intestinal resection/anastamosis with plication. There was no statistically significant difference (p>0.05) in the recurrence rate of the intussusceptions when the various surgical techniques were compared. Recurrence of an intussusception was not related to either the bowel segment involved or whether a simple reduction, bowel resection, or intestinal plication was performed at the initial surgery.     

Listeric meningoencephalomyelitis in a cougar (Felis concolor): characterization by histopathologic, immunohistochemical, and molecular methods

Listeria monocytogenes has been recognized as an important food-borne pathogen in animals. Records of the disease caused by this bacterium in large felids are, however, rare. The nervous form of listeriosis was diagnosed in a 12-year-old male cougar (Felis concolor) with a several-day history of neurologic disease characterized by excess salivation, head pressing, and circling that progressed to recumbency and death. Microscopically, the main alteration in the brain and spinal cord was a variably severe meningoencephalomyelitis composed mainly of mononuclear cell aggregates with fewer neutrophils. L. monocytogenes was isolated from the brain by microbiological culture, and L. monocytogenes antigen was detected in formalin-fixed, paraffin-embedded sections of brain and spinal cord by immunohistochemical analysis. On the basis of the nucleotide sequence of the 16S rRNA gene, the isolated strain was determined to be serotype 1/2a. Food-borne transmission of the bacterium was suspected, but food was not available for testing.     

对江苏如东首例动物防疫行政复议案件的思考

一、基本案情 今年5月23日下午,江苏省如东县经营者赵某运输一车未经检疫的生猪,计划销往江西,途经相邻的如皋市(县级市)丁堰公安查报站时被查扣.如东县动物卫生监督所接到南通市所行政处罚案件交办指令后,赶赴现场介入案件调查.经查实:赵某用牌照为苏××××××的卡车载72头生猪,未经检疫.     

Urolithiasis in the horse — A review of 13 cases

The presenting signs, treatment and postoperative progress of 13 horses with vesical and urethral calculi are reviewed. Single, discrete stones were present in 10 animals in which the results of treatment were generally good. In three horses with sabulous cystic deposits, urolithiasis was associated with bladder paralysis and the response to treatment was poor.     

Prion protein (PrP) gene polymorphisms associated with natural scrapie cases and their flock-mates in Ireland

The PrP genotypes associated with natural scrapie in Ireland were determined and a comparison was made between genotypes found in scrapie-infected sheep and those found in healthy animals from scrapie-infected flocks. Seven PrP genotypes were identified in scrapie-infected animals: VV(136)RR(154)QQ(171),VA(136)RR(154)QQ(171),VA(136)RR(154)QR(171),VA(136)RR(154)QH(171),AA(136)RR(154)QQ(171),AA(136)RR(154)QH(171) and AA(136)RR(154)HH(171). Of 11 scrapie-infected flocks, 15 genotypes were identified in the healthy flock-mates. The genotypes identified in scrapie-affected animals were also all identified in healthy flock-mates. In 9 of the 11 flocks studied, the genotype frequencies among scrapie-infected animals were significantly different from those among healthy flock-mates. The results show that there is a significant risk of developing the clinical signs of scrapie associated with particular PrP genotypes in the Irish sheep population. The association between the V(136)R(154)Q(171) allele and scrapie was evident, as was the association between A(136)R(154)R(171) and resistance to developing the clinical signs of scrapie. The presence of the A(136)H(154)Q(171) allele in the flocks examined resulted in a decreased risk of developing scrapie compared to the presence of the A(136)R(154)Q(171).