Intestinal choristoma in the subcutis of a dog

A 2-year-old, spayed female, Labrador Retriever-cross presented with a subcutaneous mass of several weeks' duration in the right flank region. Surgical excision and histologic examination were performed. The 1.0-cm-diameter mass was circumscribed, unencapsulated, and cystic with a bilayer wall. The inner layer resembled intestinal mucosa, including a tall columnar lining epithelium, crypt-like glands containing scattered neuroendocrine cells that were strongly immunopositive for synaptophysin, and a supporting lamina propria-like fibrovascular tissue that contained lymphocytes and plasma cells. The outer layer was 1- to 2-mm thick and was composed of intersecting and blending bundles of smooth muscle and collagen. Given the presence of organized intestinal tissues in the subcutis, the lesion was consistent with intestinal choristoma.     

Goblet cell hyperplasia and muscular layer thickening in the small intestine of a cynomolgus monkey

We report here the interesting case of a 5-year-old male cynomolgus monkey with goblet cell hyperplasia and thickening of the muscular layer throughout the small intestine without exhibiting any clinical symptoms. Necropsy examination showed diffuse thickening of the intestinal wall from the jejunum to the ileum, with an appearance likened to a rubber tube. Histopathologically, marked thickening was observed in both the mucosal and muscular layers in the jejunum and ileum, and slight thickening was observed in the duodenum. Goblet cell hyperplasia with extension of the circular folds and villi was prominently observed. The mucosal surface was covered with a thick mucus layer containing desquamated mucosal epithelial cells, and both the inner and outer muscular layers were markedly thickened due to smooth muscle hypertrophy. Neither macroscopic nor histopathological examination identified any causative factors, such as infection, enteritis and intestinal stenosis, or obstruction that may have caused development of this lesion. Given these observations, this case may simply be considered of spontaneous goblet cell hyperplasia and muscular layer thickening in the small intestine of a cynomolgus monkey.     

Distribution of the neurokinin-1 receptor in equine intestinal smooth muscle

REASON FOR PERFORMING STUDY: Tachykinins have profound effects on equine intestinal motility, but the distribution of the neurokinin receptors (NKRs) through which they act is unknown. This study reports the distribution of one of these receptors, the neurokinin-1 receptor (NK1R), in smooth muscle throughout the equine intestinal tract. OBJECTIVES: To quantify the distribution of the NK1R, based upon mRNA expression, in smooth muscle of different regions of the equine intestinal tract. METHODS: Nine regions of the intestinal tract were sampled in 5 mature horses. Total RNA was isolated from smooth muscle and reverse transcribed; NK1R mRNA was then quantified using real-time PCR. RESULTS: NK1R mRNA was found at all levels of the sampled intestinal tract. The smooth muscle of the proximal small intestine and the ventral colon exhibited the highest level of NK1R mRNA expression in the equine intestinal tract. CONCLUSIONS: Tachykinins probably affect intestinal contractility and propulsion in the proximal small intestine and in the ventral colon.     

The teniae of the equine intestinal tract.

At several locations along the equine cecum and colon, the outer longitudinal portion of the tunica muscularis is gathered into discrete bands of smooth muscle and connective tissue called "teniae". In this study, the disposition of the teniae ceci and coli was traced along the equine intestinal tract. It was discovered that, in several instances, arrays of teniae converge toward the valves and sphincters which separate the various intestinal compartments. The teniae may also provide support for and directionality to, peristaltic contraction waves. The tissue proportions of the teniae vary in different locations. The tenia libera lateralis of the ventral colon is rich in elastic connective tissue, while that of the right dorsal colon is primarily composed of smooth muscle. This may reflect the different responsibilities of these two compartments. The teniae are innervated and their smooth muscle cells are joined by many gap junctions. The connective tissue constituents afford intestinal support while yielding to intestinal distension. The smooth muscle and neural elements may foster active tenial participation in peristalsis. This premise must be tested by electrophysiological experimentation. Further experimentation is also necessary to ascertain whether injury to the teniae might predispose a horse to colic.     

ULTRASONOGRAPHIC DIAGNOSIS OF GASTROINTESTINAL SMOOTH MUSCLE TUMORS IN THE DOG

Historical, physical examination, clinicopathologic, radiographic and ultrasonographic findings of 13 dogs with gastrointestinal (GI) smooth muscle tumors (11 leiomyosarcomas, 2 leiomyomas) were reviewed. History, including signalment and chief complaint, physical examination and bloodwork were neither sensitive nor specific for GI neoplasia. Imaging procedures, radiology and ultrasonography, detected the presence of abdominal masses in 12 patients, including 9 animals lacking a palpable mass on initial examination. Survey radiographs of 10 of the 13 dogs revealed a mass effect in 5/10 dogs, evidence of peritoneal effusion or free abdominal gas in 3/10 dogs, and an obstructive pattern with gas and fluid distension of the intestinal tract in 1/10 dogs. Ultrasonography identified an abdominal mass in 12/13 dogs, and peritoneal effusion in 5 animals. Ultrasonography correctly recognized an association of the mass with bowel segments by the presence of intraluminal gas, within or adjacent to the mass effect, in 10 dogs, and strongly suggested an intestinal origin in one additional animal. GI smooth muscle tumors often appeared as large masses, eccentrically projecting from the bowel wall, frequently containing single or multiple hypo/anechoic regions. Based on this study we conclude that ultrasonography is more sensitive than survey radiography in the detection of GI smooth muscle tumors, and may present specific features to distinguish smooth muscle tumors from other types of GI tumors. Ultrasonography is recommended as a screening procedure for cases where GI neoplasia is suspected.     

Hypertrophic gastropathy associated with gastric sarcoma in a dog

A 14-y-old spayed female Labrador Retriever was presented with an 8-mo history of chronic vomiting. Abdominal ultrasound and gastrointestinal endoscopy revealed a mass protruding into the gastric lumen, with cytologic features suggestive of sarcoma. A partial gastrectomy was performed; the gastric body and antrum were thickened, with a cerebriform appearance of the mucosal surface. Histologic examination revealed a submucosal neoplastic proliferation of fusiform cells variably arranged in irregular bundles and scattered whorls. Fusiform cells strongly reacted to antibodies against vimentin, S100, and neuron-specific enolase; glial fibrillary acidic protein was moderately and multifocally expressed. Pancytokeratin, KIT, α–smooth muscle actin, and desmin were nonreactive. Histologic and immunohistochemical findings suggested a diagnosis of gastric sarcoma with features referable to a non-GIST (gastrointestinal stromal tumor), non–smooth muscle NIMT (non-angiogenic, non-lymphogenic intestinal mesenchymal tumor). The overlying gastric mucosa was thickened by elongated and dilated gastric glands, predominantly lined by intensely periodic acid-Schiff–stained mucous cells. This altered mucosal architecture was suggestive of Ménétrier-like disease. Although this disease has been hypothesized to predispose to gastric adenocarcinoma in dogs, an association with gastric sarcoma has not been documented previously in the veterinary literature, to our knowledge.     

In vitro effects of lidocaine on the contractility of equine jejunal smooth muscle challenged by ischaemia‐reperfusion injury

Reasons for performing study: Post operative ileus (POI) in horses is a severe complication after colic surgery. A commonly used prokinetic drug is lidocaine, which has been shown to have stimulatory effects on intestinal motility. The cellular mechanisms through which lidocaine affects smooth muscle activity are not yet known. Objectives: To examine the effects of lidocaine on smooth muscle in vitro and identify mechanisms by which it may affect the contractility of intestinal smooth muscle. Hypothesis: Ischaemia and reperfusion associated with intestinal strangulation can cause smooth muscle injury. Consequently, muscle cell functionality and contractile performance is decreased. Lidocaine can improve basic cell functions and thereby muscle cell contractility especially in ischaemia‐reperfusion‐challenged smooth muscle. Methods: To examine the effects of lidocaine on smooth muscle function directly, isometric force performance was measured in vitro in noninjured and in vivo ischaemia‐reperfusion injured smooth muscle tissues. Dose‐dependent response of lidocaine was measured in both samples. To assess membrane permeability as a marker of basic cell function, release of creatine kinase (CK) was measured by in vitro incubations. Results: Lidocaine‐stimulated contractility of ischaemia‐reperfusion injured smooth muscle was more pronounced than that of noninjured smooth muscle. A 3‐phasic dose‐dependency was observed with an initial recovery of contractility especially in ischaemia‐reperfusion injured smooth muscle followed by a plateau phase where contractility was maintained over a broad concentration range. CK release was decreased by lidocaine. Conclusion: Lidocaine may improve smooth muscle contractility and basic cell function by cellular repair mechanisms which are still unknown. Improving contractility of smooth muscle after ischaemia‐reperfusion injury is essential in recovery of propulsive intestinal motility. Potential relevance: Characterisation of the cellular mechanisms of effects of lidocaine, especially on ischaemia‐reperfusion injured smooth muscle, may lead to improved treatment strategies for horses with POI.     

The expressions of some metabolic hormones (leptin,ghrelin and obestatin) in the tissues of sheep tongue

In this study, we aimed to observe the localization and expression of peptide hormones—leptin, ghrelin and obestatin—in the sheep tongue by immunohistochemistry. For that purpose, tongues of ten adult sheep were used. Leptin expression of moderate intensity was observed in the basal and parabasal epithelial cells of the luminal epithelium, and leptin was strongly expressed in the taste buds of the circumvallate and fungiform papillae and in von Ebner's glands. Ghrelin was primarily expressed in some of the skeletal muscle cells and the smooth muscle cells of the middle layer of blood vessels. A strong expression was observed in the epithelial cells lining the base of the groove surrounding the circumvallate papillae. Obestatin expression was particularly strong in the epithelial cells of the salivary ducts. It was also stronger in the von Ebner's glands than in the seromucous glands. Leptin, ghrelin and obestatin were shown to be produced at varying levels in different cell types, including epithelial, stromal and skeletal muscle cells, as well as in ganglion neurons, neural plexuses and blood vessels in the sheep tongue. Cellular localization and expression of these peptide hormones have not been investigated in many species including sheep.     

ULTRASONOGRAPHIC AND PATHOLOGIC FEATURES OF INTESTINAL SMOOTH MUSCLE HYPERTROPHY IN FOUR CATS

The ultrasonographic findings for four cats with intestinal smooth muscle hypertrophy are described. In two cats, intestinal smooth muscle hypertrophy was associated with chronic enteritis. In the remaining two cats, intestinal smooth muscle hypertrophy affected the intestinal tract proximal to stenosis due to alimentary lymphoma and an intestinal foreign body, respectively. Moderate increased thickness of the affected intestinal wall, measuring 7-8 mm, was evident on abdominal ultrasonographic examination of all subjects. In addition, the ultrasonographic five-layered feature of the intestinal wall was maintained, and only the muscular layer appeared thickened. Abdominal ultrasound allowed a presumptive diagnosis of intestinal smooth muscle hypertrophy that was confirmed histologically in all cats.     

Spontaneous contractions of intestinal smooth muscle re-aggregates from the new-born rat triggered by thromboxane A2

Isolated smooth muscle cells from the small intestine of new-born rats were prepared by enzymatic digestion. These cells re-aggregate after 1 day in culture to clusters. The re-aggregates show spontaneous rhythmical contractions at 37 degrees C with a frequency (13.1 +/- 0.8 min-1, n = 49), which is similar to that of the intact smooth muscle layer. The cholinergic agonist carbachol (5 x 10(-5) mol l-1) caused an increase in the frequency of the spontaneous contractions often ending in a permanent contraction. A similar effect was achieved with the thromboxane A2 (TXA2) agonist, U-46619 (10(-5) mol l-1). In contrast, both the TXA2 receptor blocker, Bay u3405 (5 x 10(-4) mol l-1), as well as the Ca2+ channel blocker, verapamil (5 x 10(-5) mol l-1), suppressed the spontaneous contractions. The observed contractility was insensitive against the neuronal blocker tetrodotoxin (10(-6) mol l-1). These analyses of video images were supported by the measurement of relative changes in the intracellular Ca2+ concentration with the Ca(2+)-sensitive dye, fura-2. Spontaneous contractions were paralleled by spikes in the intracellular Ca2+ concentration, which were abolished by Bay u3405, but stimulated by U-46619 or carbachol. In summary, these results obtained at re-aggregates of intestinal smooth muscle cells support the hypothesis of a role of TXA2 in the generation of spontaneous intestinal smooth muscle contractions in vitro.     

A collision tumor consisting of granular cell tumor and adenocarcinoma in the uterus of an aged djungarian hamster

A neoplastic nodular lesion consisting of an admixture of granular cell tumor and adenocarcinoma was found in the uterus of a 26-month-old Djungarian hamster. Neoplastic cells of the uterine adenocarcinoma showed an epithelial nature in their growth patterns and by cytokeratin-immunopositive reaction, exhibiting nuclear pleomorphism. The granular cells had an abundant amount of fine granular eosinophilic cytoplasm and eccentric or central nuclei with no nuclear atypia; the granular structures were positive for periodic acid-Schiff with diastase resistance and were confirmed as lysosomes/autophagosomes by electron microscopy; immunohistochemically, the cells reacted to desmin, vimentin and α-smooth muscle actin and negatively for neurogenic, histiocyte/macrophage or epithelial markers, indicating smooth muscle origin. Because these tumors were generated from different cell origins, a diagnosis of collision tumor was made.     

An Immunohistochemical Observations on the Oviduct of the Goat

The oviduct has an important role in regulating transport of gametes and fertilization. The main role in these functions has a smooth muscle cells and ciliated epithelium lining the oviduct. All functions are under the influence of hormonal and nervous system. The objective of this study was immunohistochemically to examine the following structures: lining epithelium, smooth muscle cells, elastic fibres and nerve fibres. For this purpose, the following antibodies were used: cytokeratin 18, S‐100 protein, acetylated α‐tubulin, smooth muscle actin, desmin and elastin. Ciliary and secretory cells of the lining epithelium were positive for cytokeratin 18 and S‐100 protein. Cilia and the basal body‐associated structures of ciliary cells were positive to acetylated α‐tubulin. Smooth muscle cells (SMC) in mucosa and of the muscular layer were positive for α‐smooth muscle actin (SMA) and desmin. High density of nerve fibres positively reacted to acetylated α‐tubulin and S100 protein was present in the mucosa, muscular layer and serosa. Elastic fibres positive for elastin form a dense network at the base of the mucosal folds and in the muscle layer. A dense network of these fibres is accompanying the blood vessels. It is supposed that together with smooth muscle cells they are involved in the transport of ovum and in blood flow regulation.     

A prostate fibromyxoid sarcoma with smooth muscle differentiation in a F344xBNF1 rat

This report describes a spontaneous prostate fibromyxoid sarcoma with smooth muscle differentiation in an approximately 136-week-old intact male F344xBNF1 rat on a diet study for 2 weeks. At necropsy, the prostate was markedly distorted and enlarged by a firm white multinodular mass (6.0 × 4.5 × 3.5 cm). Histopathologically, the mass consisted of solid sheets of interlacing mesenchymal spindle cells with indistinct cell borders. Nuclei were separated by variable amounts of hyaline to fibrillar eosinophilic and/or myxomatous material. The extracellular myxomatous material tended to form whorls and stained positively with alcian blue. The mass stained strongly with Masson trichrome and vimentin throughout. Approximately 5% of the neoplastic cells were positive for smooth muscle actin, and none stained for desmin and pancytokeratin. To the authors' knowledge, this fibromyxoid sarcoma with smooth muscle differentiation is the first such described prostatic sarcoma in a rat.     

Smooth Muscle Cells of the Bovine Cervical Stroma may have a Secretory, rather than a Contractile Function during Parturition

The bovine cervix contains a large amount of smooth muscle cells distributed over an outer muscular layer and within a stromal layer. The stromal layer exhibits no electromyographic (EMG) activity at parturition. This leads to the question whether the stromal smooth muscle cells of the bovine cervix are prepared to contract with parturition, or whether they have another function. To this end, cervical biopsies were repeatedly taken from 10 pregnant cows at day-185 and -275 of gestation, at spontaneous, uncomplicated calving and at 30 days after calving. The smooth muscle bundles of the stroma were immunohistochemically analysed (n = 5) with regard to their integrity and cellular density, and the degree of staining for connexin-43, smooth muscle actin α (SMA), desmin and vimentin. Additionally, the mRNA expression for connexin-43, SMA, desmin and vimentin was determined with RT-PCR (n = 5). The smooth muscle tissue was arranged in bundles, also at parturition. However, the cellular density of these bundles and the SMA mRNA expression were decreased at parturition. Additionally, the SMA staining and connexin-43 expression and staining remained constant during pregnancy and at parturition. This might indicate that stromal smooth muscle cells are not prepared to contract with parturition, in contrast to the myometrial smooth muscle cells. The smooth muscle cells, stained for SMA, also expressed vimentin, and the proportion of co-expression was increased at day-275 of pregnancy. This suggests that the stromal smooth muscle cells predominantly have a secretory function in cows.     

Intestinal ganglioneuroma in a kitten–a case report and review of literature

An intestinal ganglioneuroma of a 6–week–old male kitten is described. The neoplasm was well circumscribed and involved a 6–5–cm segment of the jejunum, which was dilated and had a 6–10 mm thick wall. It was characterized histologically by irregularly–arranged bundles of nerve fibres, with Schwann cells and single or groups of round or angular ganglion cells. Some of the ganglion cells had satellite cells. Vessels with prominent endothelial cells, and islands of epithelial cells forming acini, were also seen. The age of the kitten and slow nature of growth of this tumour led the authors to believe that this is a case of congenital neoplasia. This is the first report of an intestinal ganglioneuroma in a cat.     

Atypical fibrosarcoma in the skin of a Roborovski hamster (Phodopus roborovskii)

A 2.5‐year‐old intact male Roborovski hamster (Phodopus roborovskii) was presented with a large subcutaneous mass overlying the abdomen, affecting the animal's ambulation and access to different compartments of the cage through narrow tubing. Ultrasound examination delineated a well‐circumscribed mass in the subcutis of the caudoventral abdominal region. The mass was surgically excised and on cytologic examination showed, in a background of blood, a small population of individually arranged oval to spindle‐shaped cells that exhibited a moderate degree of anisokaryosis, coarsely stippled chromatin, one or more prominent nucleoli, and lightly basophilic well‐defined cytoplasmic processes. Histologically, the mass was composed of interlacing streams and bundles of pleomorphic spindle cells (ganglion‐like cells) with variable amounts of collagenous stroma. The neoplastic cells exhibited moderate features of malignancy. These cells stained intensely with vimentin, but not with any other markers, including antibodies to cytokeratin AE1/AE3, S100 protein, desmin, smooth muscle actin, synaptophysin, neurofilament, and androgen receptor. Based on histologic features, the mass was diagnosed as an atypical fibrosarcoma. This is the first report of an atypical fibrosarcoma in a Roborovski hamster and one of few reports of atypical fibrosarcoma in domesticated hamsters overall.     

肺炎支原体对大鼠气管平滑肌细胞损害作用的研究

采用贴片法进行大鼠气管平滑肌细胞的培养，将不同稀释度的肺炎支原体培养液接种于单层细胞中孵育。对次日收集的细胞上清液进行肺炎支原体的PCR反应检测，结果为阳性，而冲洗液反应阴性，表明支原体对细胞具有较强的粘附性；接种后7d内观察到细胞产生明显病变，部分细胞发生崩解、脱落。MTT法检测结果表明支原体使细胞活性明显降低，其致细胞死亡率随滴度增高而增加，提示肺炎支原体对大鼠气管平滑肌可产生很强的致病性，使呼吸道受到严重损伤。本研究为探讨肺炎支原体致病作用机制及新药筛选与评价提供一种新的方法。     

A case of adenocarcinoma of the endometrium extending into the leiomyoma of the uterus in a rabbit

In a pet rabbit, 2 tumor masses one on each horn were macroscopically seen in the wall of the uterus. On light microscopic examination, the right horn mass consisted of an admixture of neoplastic epithelial and mesenchymal element. The epithelial element was composed of neoplastic epithelial cells with numerous mitotic figures and formed varied sizes of acini, glandular, and solid structures. The tumor was diagnosed as an adenocarcinoma of the endometrium. The mesenchymal element was composed of well-differentiated smooth muscle cells and was diagnosed as a leiomyoma. While adenocarcinoma cells formed a protrusive mass in the uterine lumen, they also showed an extension into the leiomyoma of the myometrium. By immunohistochemistry, adenocarcinoma stained positive for cytokeratin (MNF116) and leiomyoma stained positive for smooth muscle actin, showing a substantial difference in the cytological nature of these tumor cells. The results may give a further evidence supporting the narrative of the tumor development that an adenocarcinoma of the endometrium extended into leiomyoma of the uterus. To the author's knowledge, this is the first report describing this type of combination of two independent tumors in a pet rabbit.     

Intestinal smooth muscle cells locally enhance stem cell factor (SCF) production against gastrointestinal nematode infections

Smooth muscle cells can produce stem cell factor (SCF) in the normal state for the preservation of mast cells, but it is still unknown whether smooth muscle cells can enhance SCF production in response to the pathological stimuli. The present study showed that smooth muscle cells in mast cell-increased regions around worm cysts of intestinal nematodes significantly enhanced SCF gene expression compared with mast cell non-increased regions in same sample. SCF gene expression in mast cell non-increased regions in nematode-infected mice showed almost the same level as in non-infected control groups. These results indicate that smooth muscle cells can locally enhance SCF gene expression, and may have a role in local immunological reactions as growth factor-producing cells.