Morphology of the nerve endings in laryngeal mucosa of the horse

To discuss the significance of laryngeal sensation on various disorders of the horse, we studied the morphological and topographical characteristics of sensory structures in the laryngeal mucosa using immunohistochemistry and immunoelectron microscopy. Various sensory structures, i.e. glomerular endings, taste buds and intraepithelial free nerve endings, were found in the laryngeal mucosa by immunohistochemistry for protein gene product 9.5 (PGP 9.5) and neurofilament 200kD (NF200). Glomerular nerve endings were distributed mainly in the epiglottic mucosa; some endings were also found in the arytenoid region arising from thick nerve fibres running through the subepithelial connective tissue. Some terminals directly contacted the epithelial cells. Taste buds were distributed in the epithelium of the epiglottis and aryepiglottic fold. In the whole mount preparation, the taste buds were supplied by the terminal branching of the thick nerve fibres. In some cases, the taste buds were arranged around the opening of the duct of the epiglottic glands. The intraepithelial free nerve endings were found to be immunoreactive for substance P (SP) and calcitonin gene-related peptide (CGRP). These nerve endings were surrounded by the polygonal stratified epithelial cells in the supraglottic region, and by the ciliated cells in the subglottic region. The density of the intraepithelial free nerve endings was highest in the corniculate process of the arytenoid region and lowest in the vocal cord mucosa. The densities of CGRP- and SP-immunoreactive nerve endings in the arytenoid region were (mean +/- s.d.) 30.6+/-12.0 and 10.0+/-4.9 per unit epithelial length (1 mm), respectively and in the vocal fold mucosa, 1.1+/-0.9 and 0.8+/-0.7, respectively. Approximately one half of the CGRP immunoreactive nerve endings were immunoreactive for SP, and most SP-immunoreactive nerve endings were also immunoreactive for CGRP. Well-developed subepithelial plexus with numerous intraepithelial fibres were observed in flat or round mucosal projections that existed on the corniculate process of the arytenoid region. In conclusion, the laryngeal mucosa of the horse seems to have morphology- and/or location-dependent sensory mechanisms against various endo-and exogenious stimuli.     

Molecular insights into dietary induced colic in the horse

Equine colic, a disorder manifested in abdominal pain, is the most frequent cause of emergency treatment and death in horses. Colic often requires intestinal surgery, subsequent hospitalisation and post operative care, with a strong risk of complications arising from surgery. Therefore strategies that explore approaches for preventing the condition are essential. To this end, a better understanding of the factors and mechanisms that lead to the development of colic and related intestinal diseases in the horse allows the design of preventive procedures. Colic is a multifactorial disorder that appears to be induced by environmental factors and possibly a genetic predisposition. One factor that seems to influence the risk of developing colic is the excessive consumption of diets containing high levels of carbohydrates. Therefore, major efforts have been made by various laboratories and institutions across the world to study the type and digestibility of various feed in order to formulate accurate and safe feed components and proportions. However, relatively little work has been carried out to characterise, in detail, the carbohydrate digestive and absorptive capacity and mechanisms underlying the potential adaptive response of equine gut epithelium to a changing diet. This review focuses on advances made towards understanding the molecular and cellular mechanisms involved in digestion and absorption of dietary carbohydrates in the equine gastrointestinal tract and the implication of these processes for the whole body physiology. It addresses the underlying mechanisms that may govern the adaptive response of equine small intestine to increased dietary hydrolysable carbohydrates. Furthermore, it describes changes that occur in the equine large intestinal microbiology and host tissue biology brought about by alterations in diet and in colic. It is hoped that a better understanding of the molecular and cellular processes that play important roles in the physiology and pathology of the equine gastrointestinal tract will assist the development of effective strategies to prevent equine colic.     

非洲马瘟病毒分子生物学研究进展

非洲马瘟病毒属呼肠病毒科环状病毒属,有9个血清型,是一种有10个节段(L1~L3,M4~M6,S7~S10)的双链RNA病毒,编码10个蛋白(VP1~VP7和NS1,NS2,NS3/NS3A)。VP2蛋白在病毒的各蛋白中变异率最大,有15个抗原位点,是病毒的血清型特异性抗原,能与病毒的中和抗体发生反应;VP7蛋白在病毒的各蛋白中最保守,是病毒的血清群特异性抗原。NS1蛋白在感染细胞中形成病毒特异性微管结构;NS3蛋白在病毒各蛋白中变异率位居第二,系统进化分析将NS3分成3个进化群(α,β和γ)。该病毒的分子生物学诊断技术主要有RT-PCR和核酸探针技术。     

Molecular genetic studies of the "Einsiedler" horse population

In this study it was investigated whether the "Einsiedler" warmblood horse, a historically old horse population from central Switzerland (Abbey of Einsiedeln), is distinguishable from micellaneous horse breeds, using molecular genetic techniques. The breeding history of Einsiedler horses is characterised by systematic line breeding through the dams. Therefore, two Einsiedler dam lines (N = 28), going back to the middle of the 19th century according to pedigree entries, were the focus of the survey. Random samples of diverse warmblood horse populations, but also samples from more distinct types of horse breeds, served as comparison populations (N = 52).Variation in the mitochondrial genome appeared to be only partially informative to demarcate the studied horses, as horses of distinct breeds may share identical mtDNA sequence fragments. Both dam lines revealed haplotypes commonly found in Iberian horse breeds. This is to take as an indication on the genetic origin of Einsiedler horses. Furthermore, the Klima dam line held a homologous mtDNA sequence fragment with E. ferus przewalskii. Therefore, this seems to be a phylogenetically old haplotype. The analysis of microsatellite loci revealed that horses from the two Einsiedler dam lines were in fact distinguishable from more distinct types of horses, but not from closely related European warmblood horse breeds and English thoroughbred.     

Molecular detection of Coxiella burnetii in horse sera in Iran

Coxiella burnetii is a zoonotic bacterium that can infect a wide range of animals including horses. However, its circulation dynamics in and through horses are still unclear. The aim of this study was to evaluate prevalence of C. burnetii and its genomic characteristics in horse sera samples in the North of Iran (Golestan Province). The samples were collected in 2018 and the age, sex, and breed of each animal were recorded. Nested-PCR was used to detect C. burnetii based on the presence of the transposable gene IS1111. The results showed that 7.50 % (P < 0.05; 95 % CI: 0.5 %–0.12 %) of the examined sera samples were positive for C. burnetii. Based on the resuls, prevalence of C. burnetii in the age groupof < Years 1–5 (p-value <0.05, 95 % CI: 1 %–8 %) was less than the age group of >6 years old (p-value <0.05, 95 %, CI: 7 %–19.8 %). In previous studies, it was concluded that the horses' population in Golestan Province should be considered as an important factor in the epidemiology of Q fever and consequently in public health. Further studies should be implemented to evaluate if horses may be relevant indicators of zoonotic risk in urban and suburban endemic areas.     

Molecular identification of Phialophora oxyspora as the cause of mycetoma in a horse

CASE DESCRIPTION: An 18-year-old mare was evaluated for an oral mass that developed after extraction of a broken incisor. CLINICAL FINDINGS: An ulcerated, firm, darkly pigmented, approximately 5-cm-diameter spherical mass involved the gingiva lateral and dorsal to the right first to third maxillary incisors. Osteolysis of the roots of the first and second right maxillary incisors and periosteal proliferation of the adjacent premaxilla margins were apparent on radiographs. Histologic examination of the mass revealed multiple coalescing and ramifying foci of abscess formation, each containing a well-defined, discrete, black mass (2 to 7 mm in diameter). Myriad fungal hyphae enmeshed in a black, granular, cementlike material were within each of the black structures. Mycetoma was the histologic diagnosis. The causative agent could not be identified via culture because of lack of distinguishing characteristics. Fungal DNA was isolated from frozen fungal cultures and paraffin sections. The D1/D2 domains of the large subunit P gene rDNA were amplified and sequenced. The sequences of the D1/D2 domains of both isolates were 96% homologous with those of Phialophora oxyspora. TREATMENT AND OUTCOME: The mass was surgically excised, the local area curetted, and the wound allowed to heal by second intention. Postoperative treatment consisted of administration of phenylbutazone and IV administration of sodium iodide followed by oral administration of potassium iodide. There was no evidence of recurrence 1 year later. CLINICAL RELEVANCE: Mycetomata should be a differential diagnosis for equine gingival masses. Identification of the fungal agent can be critical for selection of optimal treatments. Molecular methods may permit definitive identification when standard phenotypic-based identification criteria are inconclusive.     

Molecular forms of selected antioxidant enzymes in dog semen--electrophoretical identification

The aim of the study was the electrophoretical identification of molecular forms of selected antioxidant enzymes in dog semen. Ejaculates to be studied were chosen from five dogs, aged from two to eight years. Polyacrylamide gel electrophoresis was carried out under non-denaturing conditions and then gels were stained for the activity of the following enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Sperm homogenates and all fractions (pre-spermatic, spermatic and post-spermatic) of dog ejaculate demonstrated one protein band with SOD activity characterized by low electrophoretic mobility. Based on the confirmed sensitivity to H2O2, it can be assumed that the detected SOD is an enzyme containing ions of Zn2+ and Cu2+ (Cu,Zn SOD). In sperm homogenates one protein band with GPx activity was characterized by high electrophoretic mobility, whereas in the spermatic and post-spermatic fractions of dog ejaculate three protein bands with different (low, medium and high) electrophoretic mobility were identified. CAT molecular forms were not found in either sperm homogenates or in the analyzed fractions of ejaculate.     

Magnetic resonance imaging features of an extranodal T cell rich B cell lymphoma in the pharyngeal mucosa in a horse

An 11‐year‐old Warmblood gelding was presented for inspiratory stridor and dysphagia. Based on history and clinical examination, a solitary mass localised in the oropharynx was suspected. Due to its inaccessibility and defensive behaviour of the horse, it was difficult to visualise this mass either by upper airway endoscopy or by oral examination and the conventional imaging methods (radiology and ultrasound) provided only limited information. Fine needle aspiration cytology was suggestive of lymphoma, but the exact localisation and the extent of tissue infiltration of the tumour could only be defined by magnetic resonance imaging (MRI). MRI has proved to be a very useful diagnostic tool in equine lameness investigation and, as this case illustrates, it has considerable diagnostic potential for soft tissue examination of the equine head.     

The effects of phenylbutazone on the intestinal mucosa of the horse: a morphological, ultrastructural and biochemical study

Phenylbutazone, a non-steroidal anti-inflammatory drug known to produce intestinal erosions, was administered intravenously (13.46 mg/kg bodyweight) to 12 horses which were killed after 24, 48, 72 and 96 h. Eight untreated horses served as controls. Annular erosions in the duodenum and mucosal necrosis in the colon were seen after 48 h which progressed in severity. The erosions were characterised by sloughing of the surface epithelium, subepithelial cleft and bleb formation, necrosis of the lamina propria, degeneration of the walls of subsurface capillaries and microthrombosis. Large numbers of neutrophils with abundant fibrin and cellular debris were present at the erosion sites. Ultrastructurally, there was swelling of the endothelium of capillaries and small vessels, and of pericyte and smooth muscle cytoplasm in arterioles. In capillaries and post capillary venules, the endothelium ranged from swollen to lysed and necrotic. Extensive extravasation of erythrocytes and oedema were seen. These lesions were not seen in the control horses. Phenylbutazone produces a microvascular injury associated with the formation of duodenal and colonic erosions in horses. The duodenal and colonic mucosa were assayed at 48 and 96 h for prostacyclin and PGE2. There was no statistically significant difference between prostaglandin levels in the mucosa of control and treated horses. It was concluded that there was no correlation between mucosal prostaglandin levels and intestinal erosions after 48 h.     

Molecular identification of Candida parapsilosis from crop mucosa in a cockatiel.

A 2-month-old cockatiel was evaluated for diarrhea, dyspnea, and death. Histologic examination of lesions in the crop mucosa revealed hyperkeratosis and the presence of blastoconidia and hyphae. Positive immunohistochemical staining of the organisms was achieved with an antibody directed against Candida spp. Polymerase chain reaction amplification of DNA from crop lesion material with internal transcribed spacer 2 (ITS2) primers yielded fragments of approximately 300 bp, which demonstrated 95% DNA homology with the corresponding sequence from a strain of Candida parapsilosis deposited in the GenBank data base. The Candida species in the lesion of the crop mucosa was therefore identified by DNA sequence analysis as C. parapsilosis.     

Monorchidism in the horse

Six horses with monorchidism, identified at surgery for cryptorchidectomy, are reported. All six presented with a single scrotal testis. Following surgical removal of one testis, they were either hormonally, anatomically or behaviourally determined to be geldings. Three other horses reported in the literature are reviewed. Of these nine cases of monorchidism, eight were thought to be caused by testicular degeneration and one by testicular agenesis. The vaginal process was present in all of the former and absent in the latter. The left side was involved in five of these eight horses. In seven, the epididymis was absent and, in the remaining two, only the epididymal tail was present. The condition was thought to be congenital in the six horses in this series. A surgical approach to identify accurately monorchid horses is described.     

Haemangiosarcoma in the horse

Neoplasms arising from vascular endothelial cells include benign haemangioma and malignant haemangiosarcoma, both of which are rare in the horse. Haemangiosarcoma can arise as a solitary mass, typically involving the eye or skin, or as disseminated tumours throughout multiple organs. There is no sex, breed or age predilection but most cases are found in middle aged horses. Clinical presentations of haemangiosarcoma in the horse include the presence of a visible mass or reflect dysfunction of the organ involved, thus making it difficult to differentiate from other neoplasms. Ante mortem diagnosis through clinicopathological findings, cytological findings of body cavity effusions or fine needle aspirates are often unrewarding. Biopsy or mass submission for histopathological examination may aid in diagnosis of haemangiosarcoma. A majority of cases are diagnosed post mortem; however, if the mass is poorly differentiated additional diagnostics such as immunohistochemical staining may be needed. Unfortunately, treatment of haemangiosarcoma is often unrewarding and limited based on the location of the mass and the aggressive nature of this neoplasm.