Immunohistochemistry (IHC) is a laboratory technique used to visualize specific antigens in tissue sections of horses through the application of antibodies. This method allows for the detailed examination of the distribution and localization of proteins within equine tissues, providing insights into various physiological and pathological processes. IHC is employed in equine research to study a range of conditions, including infectious diseases, inflammatory responses, and neoplastic disorders. By utilizing specific antibodies that bind to target antigens, researchers can identify cellular and tissue changes, contributing to a better understanding of equine health and disease mechanisms. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of immunohistochemistry in the field of equine research.
Wong DM, Ghosh A, Fales-Williams AJ, Haynes JS, Kanthasamy AG.The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also ...
Pennick KE, McKnight CA, Patterson JS, Latimer KS, Maes RK, Wise AG, Kiupel M.Immunohistochemistry (IHC) and in situ hybridization (ISH) can be used either to detect or to differentiate between Eastern equine encephalitis virus (EEEV) and West Nile virus (WNV) within formalin-fixed, paraffin-embedded (FFPE) brain tissue of horses. To compare the diagnostic sensitivity and specificity of ISH and IHC, FFPE brain tissue from 20 EEEV-positive horses and 16 WNV-positive horses were tested with both EEEV and WNV oligoprobes and EEEV- and WNV-specific antibodies. Reverse transcription polymerase chain reaction (RT-PCR) for detection of EEEV and WNV was used as the gold standar...
Gordon AN, Marbach CR, Oakey J, Edmunds G, Condon K, Diviney SM, Williams DT, Bingham J.A 5-year-old Australian stock horse in Monto, Queensland, Australia, developed neurological signs and was euthanized after a 6-day course of illness. Histological examination of the brain and spinal cord revealed moderate to severe subacute, nonsuppurative encephalomyelitis. Sections of spinal cord stained positively in immunohistochemistry with a flavivirus-specific monoclonal antibody. Reverse transcription polymerase chain reaction assay targeting the envelope gene of flavivirus yielded positive results from brain, spinal cord, cerebrospinal fluid, and facial nerve. A flavivirus was isolate...
Holzhausen L, Nowak M, Junginger J, Puff C.A 15-year-old gelding presented with a progressive lameness of the left forelimb of 2.5 months duration. Clinically, a dilation of the deep flexor tendon sheath with a firm elastic consistency and a pronounced tenderness was noted. Ultrasonically, a marked swelling of the flexor tendon sheath with an irregular density of the mesotendineum was observed. The white, firm material forming a nodular distension of the flexor tendon sheath with a diameter of approximately 1 cm was excised and sent for histopathological examination. Biopsies of the deep flexor tendon and corresponding tendon sheath we...
Henson FM, Getgood AM, Caborn DM, McIlwraith CW, Rushton N.To investigate effects of 1% hyaluronic acid-chondroitin sulfate-N-acetyl glucosamine (HCNAG) on the damage repair response in equine articular cartilage. Methods: Articular cartilage from 9 clinically normal adult horses. Methods: Full-thickness cartilage disks were harvested from the third metacarpal bone. Cartilage was single-impact loaded (SIL) with 0.175 J at 0.7 m/s and cultured in DMEM plus 1 % (vol/vol) HCNAG or fibroblastic growth factor (FGF)-2 (50 ng/mL). Histologic and immunohistochemical techniques were used to identify tissue architecture and apoptotic cells and to immunolocalize...
Swadzba ME, Hirmer S, Amann B, Hauck SM, Deeg CA.Although the presence of IgG autoantibodies in the vitreous of spontaneous cases of equine recurrent uveitis (ERU) has been demonstrated, the potential role of IgM reactivities during ERU pathogenesis remains unexplored. The purpose of this study was to examine the presence of IgM autoantibodies in vitreous specimens of ERU-affected horses and to test their binding specificity to intraocularly expressed proteins. Methods: To test IgM autoantibody responses to retinal tissue, vitreous samples of eye-healthy controls and ERU patients were analyzed via two-dimensional Western blot analysis with e...
Stumpf G, Fietz D, Ezer J, Litzke LF, Bergmann M.Surgically removed testicular tissue in cryptorchid stallions is sometimes difficult to identify because of morphological and histological malformation. Therefore, a sure method to characterise the removed tissue is required. A 2-year-old Haflinger stallion was castrated after diagnosis of cryptorchidism to remove the left intra-abdomnial testis. Intra-operative exploration of the abdominal cavity revealed a firm, dysmorphic structure, which could not be identified as testis based on macroscopic anatomy. The removed tissue was Bouin-fixed and paraffin-embedded for histological examination. We ...
Leise BS, Faleiros RR, Watts M, Johnson PJ, Black SJ, Belknap JK.A significant proinflammatory response is known to occur in the forelimb lamina after carbohydrate administration. As the hindlimbs are often less affected by laminitis compared with the forelimbs, we assessed hindlimb inflammatory response in the early stages of carbohydrate-induced laminitis to determine whether differences in the response existed. Objective: To determine whether a similar proinflammatory response occurs in the hindlimb laminae to that previously reported for the forelimb. Methods: Archived laminar samples from 12 horses administered 17.6 g of starch (85% corn starch, 15% wo...
Grosche A, Freeman DE, Morton AJ, Polyak MM, Matyjaszek SA.To assess the effects of ischemia and reperfusion on indicators of oxidative stress, activation of eosinophils, and apoptosis in the large colonic mucosa of horses. Methods: 40 horses. Methods: In 1 or two 20-cm-long segments of the pelvic flexure, ischemia was induced for 1 or 2 hours followed by no reperfusion or 30 minutes and 18 hours of reperfusion in anesthetized horses. Mucosal specimens were collected before (controls; n = 20 horses) and after each period of ischemia, and full-thickness tissue samples were collected after each period of reperfusion. Sections of colonic tissues were sta...
Deeg CA, Eberhardt C, Hofmaier F, Amann B, Hauck SM.Autoimmune uveitis is an intraocular inflammation that arises through autoreactive T-cells attacking the inner eye, eventually leading to blindness. However, the contributing molecular pathomechanisms within the affected tissues remain as yet elusive. The extracellular matrix (ECM) is a highly dynamic structure that varies tremendously and influences the encompassing tissue. In order to assess ECM re-modeling in autoimmune uveitis, we investigated the expression of ECM molecules fibronectin and osteopontin in vitreous and retina samples. This was carried out in the only spontaneous animal mode...
Grigolo B, Desando G, Cavallo C, Zini N, Ghisu S, Facchini A.Association of biomaterials with autologous cells can provide a new generation of implantable devices for cartilage repair. An ideal scaffold should possess a preformed three-dimensional shape, fix the cells to the damaged area and prevent their migration into the articular cavity. Furthermore, the constructs should have sufficient mechanical strength to facilitate handling in a clinical setting and stimulate the uniform spreading of cells and a phenotype re-differentiation process. The aim of this study was to verify the ability of an equine collagen membrane to support the growth of human ch...
Uzal FA, Diab SS, Blanchard P, Moore J, Anthenill L, Shahriar F, Garcia JP, Songer JG.Clostridium perfringens type C is one of the most important agents of enteric disease in newborn foals. Clostridium difficile is now recognized as an important cause of enterocolitis in horses of all ages. While infections by C. perfringens type C or C. difficile are frequently seen, we are not aware of any report describing combined infection by these two microorganisms in foals. We present here five cases of foal enterocolitis associated with C. difficile and C. perfringens type C infection. Five foals between one and seven days of age were submitted for necropsy examination to the Californi...
Tokunaga S, Fujiki M, Yabuki A, Misumi K.Cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA), which appears abundantly in hypertrophic cartilage at the stage of endochondral ossification, is also detected in cerebrospinal fluid (CSF) following spinal cord injury. In this study, the localization of the CD-RAP/MIA molecule in normal tissues of the spine and brain obtained from mice, rats, dogs, cattle and horses was examined using immunohistochemistry with a specific antibody. The positive signals of CD-RAP/MIA were found at nerve cells in the spinal cords of all species and were especially str...
Almeida J, Conley AJ, Mathewson L, Ball BA.Sertoli cells are essential in development of a functional testis. During puberty, Sertoli cell maturation can be characterized by a number of markers, including anti-Müllerian hormone (AMH) and its receptor (AMHR2), androgen receptor (AR), cyclin-dependent kinase inhibitor (CDKN1B), and connexin 43 (Cx43). In the present study, immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to characterize changes in expression of AMH, AMHR2, AR, CDKN1B, and Cx43 in prepubertal, postpubertal, and adult equine testes. During puberty, AMH expression decrease...
Wilsher S, Gower S, Allen WR.Previous reports documenting progesterone receptors (PR) and oestrogen receptors (ER) in the endometrium of early pregnant mares included specimens only up to Day 20 post ovulation. This study aimed to localise PR and ERα on equine feto-maternal tissues between Days 20 and 68 to encompass the period around fixation of the conceptus, development of the endometrial cups and attachment and initial interdigitation of the allantochorion. During early pregnancy mares had the same pattern of PR in the endometrium as that reported for other mammals; namely, a loss of PR from the endometrial epithelia...
Sprekeler N, Müller T, Kowalewski MP, Liesegang A, Boos A.In many species, the small intestine is the major site of calcium (Ca(2+)) absorption. The horse differs considerably from most other species with regard to the physiology of its Ca(2+) metabolism and digestion. Thus, this study was performed to get more information about the transcellular Ca(2+) absorption in the horse.Two mechanisms of intestinal Ca(2+) absorption are described: the passive paracellular pathway and the active, vitamin D-dependent transcellular pathway. The latter involves the following elements: vitamin D receptors (VDR), transient receptor potential vanilloid channel member...
Regan DP, Aarnio MC, Davis WS, Carmichael KP, Vandenplas ML, Lauderdale JD, Moore PA.Equine recurrent uveitis (ERU) is a spontaneous disease that is the most common cause of blindness in horses, affecting up to 15% of the horse population. Th17 cells are a major cell population driving the pathogenesis in several mouse models of autoimmune inflammation, including experimental autoimmune uveitis. The purpose of this study is to investigate the role a Th17 cell-mediated response plays in the pathogenesis of ERU. Methods: Banked, Davidson's-fixed equine globes histopathologically diagnosed with ERU (n = 7) were compared immunohistochemically with healthy control globes (n = 7). I...
Herder V, Barsnick R, Walliser U, Teifke JP, König P, Czerwinski G, Hansmann F, Baumgärtner W, Hewicker-Trautwein M.An equid herpesvirus 5 (EHV-5) infection was detected in lesioned skin from a nine-year-old Holsteiner stallion in the south of Germany. Macroscopically, the animal displayed a non-pruritic, multifocal, pustular dermatitis around both eyes, nostrils and the muzzle, which had been ongoing for one year. Histopathologically, skin lesions were characterized by orthokeratotic to parakeratotic hyperkeratosis, pustular dermatitis, epidermal hyperplasia, apoptotic keratinocytes, a lympho-plasmahistiocytic interface dermatitis with hydropic degeneration of keratinocytes, and perivascular to diffuse, ly...
Artese L, Piattelli A, Di Stefano DA, Piccirilli M, Pagnutti S, D'Alimonte E, Perrotti V.The aim of the present study was to perform a comparative histological and immunohistochemical evaluation of microvessel density, vascular endothelial growth factor, and nitric oxide synthase (NOS) expression in sinus augmentation using autologous bone alone or in combination with equine bone. Methods: Sixteen patients underwent sinus augmentation with autologous bone and a 50:50 mixture of autologous and equine bone. Control cores were harvested from preexisting nonaugmented bone under the sinus floor. The specimens were processed for immunohistochemistry. Results: The greatest values of micr...
Coli A, Nocchi F, Lamanna R, Iorio M, Lapi S, Urciuoli P, Scatena F, Giannessi E, Stornelli MR, Passeri S.The amnion is a particular tissue whose cells show features of multipotent stem cells proposed for use in cellular therapy and regenerative medicine. From equine amnion collected after the foal birth we have isolated MSCs (mesenchymal stem cells), namely EAMSCs (equine amnion mesenchymal stem cells), from the mesoblastic layer. The cells were grown in α-MEM (α-modified minimum essential medium) and the effect of EGF (epidermal growth factor) supplementation was evaluated. To assess the growth kinetic of EAMSCs we have taken into account some parameters [PD (population doubling), fold increas...
Dobromylskyj MJ, Copas V, Durham A, Hughes TK, Patterson-Kane JC.A 9-year-old Haflinger mare presented to the Liphook Equine Hospital with a history of weight loss, azotemia, and repeated episodes of ascites over a period of 10 days. The horse was euthanized after exploratory laparotomy revealed large numbers of variably sized masses distributed throughout the peritoneal cavity. Macroscopically, some masses were papillary, while others were nodular. Histologically, the masses were comprised of large to giant, variably shaped, and occasionally multinucleated neoplastic cells with marked anisokaryosis and anisocytosis and a high mitotic rate. Small to moderat...
Sedacca K, Samuelson D, Lewis P.To investigate the uveoscleral (US) pathway in the normal eyes of four domestic spp.: the cat, pig, cow and horse by examining the comparative anatomical structure of anterior US pathway. Methods: Four cats, ten pigs, four cows, eight horses. Methods: Formalin-preserved specimens from anterior uveas of the cat, pig, cow and horse were embedded and serially sectioned sagittally and tangentially and stained with H&E, Masson's trichrome, smooth muscle actin immunolabel, or elastin stain. Results: Spaces between the endings of the outer anterior ciliary body musculature (CBM) formed avenues fo...
Pavone S, Gialletti R, Pepe M, Onofri A, Mandara MT.In this study we investigated the histological changes of the myenteric plexuses and interstitial cells of Cajal (ICC) in gut samples from horses with colic to try to find results useful in the prognostic evaluation of enteric lesions. A morphologic and quantitative study of myenteric ganglia, ganglion cells and neuronal chromatolytic and necrotic changes of 24 horses with colic was performed. For ganglion cells, enteroglial cells and ICC immunolabeling was also performed to identify cell functional disorders. A significant increase of neuronal chromatolysis and necrosis occurred in horses suf...
Lehmann J, Ellenberger C, Hoffmann C, Bazer FW, Klug J, Allen WR, Sieme H, Schoon HA.The aim of the present study was to characterize the morpho-functional features of endometrosis in barren and foaling mares, using both conventional histopathological and immunohistochemical methods. Endometrial biopsy samples were collected during the physiological breeding season from 159 estrous, clinically healthy mares (mean age 12 years), and the quality and degree of endometrosis was histomorphologically defined. The mares were bred and those that foaled were put in the foaling group whereas those that did not foal were placed in the barren group. Foaling mares were then compared with b...
McIlwraith CW, Frisbie DD, Rodkey WG, Kisiday JD, Werpy NM, Kawcak CE, Steadman JR.This study evaluated intra-articular injection of bone marrow-derived mesenchymal stem cells (BMSCs) to augment healing with microfracture compared with microfracture alone. Methods: Ten horses (aged 2.5 to 5 years) had 1-cm2 defects arthroscopically created on both medial femoral condyles of the stifle joint (analogous to the human knee). Defects were debrided to subchondral bone followed by microfracture. One month later, 1 randomly selected medial femorotibial joint in each horse received an intra-articular injection of either 20 × 10(6) BMSCs with 22 mg of hyaluronan or 22 mg of hyalurona...
Chiavaccini L, Hassel DM, Shoemaker ML, Charles JB, Belknap JK, Ehrhart EJ.The black walnut extract (BWE) model of equine laminitis is associated with a systemic inflammatory response manifest by increased expression of inflammatory cytokines in the lungs and liver as well as the laminae. The specific role of the gastrointestinal tract in development of this response is unclear and is of utmost importance, as gastrointestinal disease and laminitis are intimately related. We investigated calprotectin expression and epithelial and endothelial apoptosis in the colon of horses exposed to orally administered BWE. Sections of colon from 19 horses including 7 controls not e...
Martins TB, Kommers GD, Trost ME, Inkelmann MA, Fighera RA, Schild AL.Twenty-one cases of pythiosis in horses (n = 10), dogs (n = 9) and cattle (n = 2) were investigated. The aetiology in all cases was confirmed by immunohistochemistry. Data related to the clinical course and outcome and localization of the lesions were obtained from pathology reports. The equine lesions consisted of fibrotic tissue with multiple, often coalescing, areas of immature granulation tissue encircling eosinophilic cores. Affected dogs had gastrointestinal and/or cutaneous lesions with either or both of a granulomatous/pyogranulomatous or necrotizing eosinophilic inflammatory reaction....
Hopster-Iversen C, Hopster K, Staszyk C, Rohn K, Freeman D, Rötting AK.Large intestinal diseases in horses are characterised by inflammation, which could arise from the disease process with some contribution from intestinal manipulation. The effects of the latter are unknown but important to surgeons and could contribute to post operative complications. Objective: To characterise type and degree of intestinal inflammation induced by various mechanical stimuli in the equine ascending colon. Methods: Laparotomy was performed in 12 horses, the left dorsal colon exteriorised and 3 segments randomly exposed to different mechanical manipulations: 1) enterotomy, 2) ente...
Mair TS, Pearson GR, Scase TJ.Three mature horses presented with progressive weight loss, inappetence, ventral abdominal oedema and lethargy. Two of the animals had intermittent signs of low grade abdominal pain. At presentation, all 3 had hypoalbuminaemia; 2 had hyperfibrinogenaemia and the other had neutrophilia. An oral glucose tolerance test was performed in 2 cases, both of which demonstrated impaired glucose absorption. One pony treated with corticosteroids failed to improve and developed peritonitis and was subjected to euthanasia after 2 weeks. One pony had small intestinal biopsies obtained via a standing flank la...
Ibrahim S, Steinbach F.Earlier studies investigating the cross-reactivity of antibodies submitted to the HLDA8 had used flow cytometry as a method of choice to screen mAbs for reactivity with equine leukocytes, including two-color flow-cytometry to characterize the lymphocyte population they detect. In addition, immuno-histochemistry (IHC) was used to detect distribution of positive cells in lymphoid tissue sections. In this study we performed immunoprecipitation (IP) to complement the previous results and add valuable information regarding the molecules detected by the cross-reacting antibodies. Surface molecules f...
Samoilowa S, Giessler KS, Torres CEM, Hussey GS, Allum A, Fux R, Jerke C, Kiupel M, Matiasek K, Sledge DG, Goehring LS.Equid herpesvirus-1 (EHV-1) causes respiratory disease, abortion and myeloencephalopathy in horses worldwide. As member of the , latency is key to EHV-1 epidemiology. EHV-1 latent infection has been detected in the trigeminal ganglion (TG), respiratory associated lymphoid tissue (RALT) and peripheral blood mononuclear cells (PBMC) but additional locations are likely. The aim of this study was to investigate the distribution of viral DNA throughout the equine body. Twenty-five horses divided into three groups were experimentally infected via intranasal instillation with one of three EHV-1 virus...
Pérez J, Mozos E, Martín MP, Day MJ.The distribution of T (CD3), B (CD79) lymphocytes, immunoglobulin (IgG, IgM and IgA)-producing plasma cells, macrophages (lysozyme, Mac387) and MHC Class II antigen was analysed in the inflammatory infiltrate associated with 19 equine squamous cell carcinomas (SCCs) and six cases of precancerous lesions (actinic keratosis). The SCCs came from the penis (11 cases), conjunctiva (four), skin (two), nasal cavity (one) and oral cavity (one). Seven cases were well-differentiated and 12 moderately differentiated. Nine cases showed no invasion of peritumoral deep tissues (locally invasive), whereas th...
Kendall A, Nyström S, Ekman S, Hultén LM, Lindahl A, Hansson E, Skiöldebrand E.Nerve growth factor (NGF) is a neurotrophin with many functions. In humans, it is involved in inflammation, nerve growth, apoptosis and pain signalling. Increased concentrations of NGF in synovial fluid has been shown in humans and dogs with osteoarthritis. Despite osteoarthritis being a common problem in horses, no studies have previously been published on NGF in the equine joint. The aim of this study was to quantify NGF in equine synovial fluid from healthy joints, acutely inflamed septic joints and joints with structural changes associated with osteoarthritis. A secondary aim was to identi...
McGorum BC, Scholes S, Milne EM, Eaton SL, Wishart TM, Poxton IR, Moss S, Wernery U, Davey T, Harris JB, Pirie RS.Equine grass sickness (EGS) is of unknown aetiology. Despite some evidence suggesting that it represents a toxico-infection with Clostridium botulinum types C and/or D, the effect of EGS on the functional targets of botulinum neurotoxins, namely the soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins, is unknown. Further, while it is commonly stated that, unlike EGS, equine botulism is not associated with autonomic and enteric neurodegeneration, this has not been definitively assessed. Objective: To determine: 1) whether botulism causes autonomic and enteric neurodeg...
Schlegel T, Brehm H, Amselgruber WM.The third eyelid of domestic animals is important for the production and distribution of tears, in removing ocular debris and in protection of the globe, and has significant immunologic functions. Although it is known that tears contain antibodies of the immunoglobulin A (IgA) isotype which are produced mainly by plasma cells of the lacrimal gland, very little is known about the antibody repertoires in the third eyelid of domestic animals. To assess whether IgA is derived from local synthesis, we analyzed the location of IgA-producing cells and the cellular distribution of secretory component ...
Quiroz-Rothe E, Rivero JL.Combined methodologies of immunohistochemistry, histochemistry and photometric image analysis were applied: (1) to characterise control equine skeletal muscle fibres according to their myosin heavy chain (MyHC) composition and (2) to determine on a fibre-to-fibre basis the correlation between contractile [i.e. MyHC(s), myofibrillar ATPase (mATPase) and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) isoforms], metabolic [i.e. succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPD) activities, glycogen and phospholamban (PLB) contents], and morphological [i.e. cross-sect...
McKelvie J, Foster AP, Cunningham FM, Hamblin AS.Circulating lymphocyte numbers are elevated in horses with the allergic skin disease sweet itch and skin lesions are typified by an infiltrate of eosinophils and mononuclear cells, the latter of which have not been fully characterised. The aim of the present study was to characterise the lymphocyte subpopulations in the circulation and skin of ponies with sweet itch by flow cytometry and a newly developed modified alkaline phosphatase immunohistochemical technique. Sweet itch ponies were found to have significantly greater numbers of circulating CD5+ and CD4+ T-lymphocytes than normal animals....
Ahdy AM, Ahmed BM, Elgamal MA, Shaalan M, Farag IM, Mahfouz ER, Darwish HR, Sayed-Ahmed MZ, Shalaby MA, El-Sanousi AA.Equid alphaherpesvirus 1 (EHV-1) is an important virus causing pathological disorders in horses. This highly contagious pathogen causes persistent outbreaks of upper respiratory tract infection, ocular affections, abortion, and neurological disorders with high mortality in Arabian horses in Egypt. The quick and accurate diagnosis is important to broaden our understanding about EHV-1 in the field, and to implicate stronger preventive, and control measures. Sixty-six Arabian horses from Cairo and Giza governorates were sampled from respiratory, abortigenic and neurological outbreaks over a perio...
Wong DM, Ghosh A, Fales-Williams AJ, Haynes JS, Kanthasamy AG.The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also ...
Clark RK, Galantino-Homer HL.Equine laminitis is a common, painful, debilitating condition of the hoof that is a leading cause of disability in horses, often necessitating euthanasia. The equine hoof represents an extreme evolutionary adaptation of an epidermal structure homologous to the human or murine nail units. Immunohistochemistry is frequently utilized in the study of the pathophysiology of laminitis. The complex, multilayered, extensively interdigitated epidermal-dermal lamellar interface renders precise interpretation of immunofluorescence localization difficult, especially when effective technique and reagents r...
White KS, Fuji RN, Valentine BA, Bildfell RJ.Abstract Congenital cutaneous papillomas were identified in five foals. Age at diagnosis ranged from 305 days' gestation to 2 days of age. Breeds were thoroughbred (2), standard-bred (1), warmblood (1) and paint (1). Two were female, one was male and the gender of two cases was not specified. Masses were pedunculated with a roughened, wart-like (verrucous) or a smoother, cauliflower-like surface. Masses occurred as single lesions on the forelimb, lip and face, or as multiple lesions on the trunk. Histological features included relatively uniform epidermal papillary hyperplasia with variable me...
Contreiras EC, Lenzi HL, Meirelles MN, Caputo LF, Calado TJ, Villa-Verde DM, Savino W.We characterized herein the microarchitecture of the equine thymus along with post-natal development (6 months-->18 years). Thymuses showed an involutional process, beginning before the puberty and defined by five histological grades, which consider the progressive cortical thymocyte depletion, shrinkage and rearrangement of the epithelial network and increase in extracellular matrix (ECM). A second feature of the equine thymus was the presence of eosinopoiesis, erythropoiesis, mastocytopoiesis and plasmacytogenesis. Additionally, lymphatic vessels, full of lymphocytes, were particularly pr...
van den Ingh TS, Binkhorst GJ, Kimman TG, Vreeswijk J, Pol JM, van Oirschot JT.A horse with neurological signs and severe meningoencephalitis caused by Aujeszky's disease is described. The diagnosis was established by immunohistochemistry, DNA-in situ hybridization and serological tests. Aujeszky's disease virus antigen and Aujeszky's disease viral DNA were detected in neurons of the cerebrum. In the serum of the horse antibodies against Aujeszky's disease virus were detected in a virus neutralization test, in a blocking ELISA which specifically detects antibodies against the glycoprotein I (Ig) of the virus, in an indirect double sandwich ELISA and with colloidal gold i...
Gibson C, de Ruijter-Villani M, Stout TAE.In many species, the insulin-like growth factors (IGF1 and IGF2), their receptors and IGF binding proteins play important roles in preparing the endometrium for implantation, and regulating conceptus growth and development. To determine whether the IGF system may contribute to conceptus-maternal interaction during equine pre-implantation development, we evaluated mRNA expression for IGF system components in conceptuses, and endometrium recovered from pregnant and cycling mares, on days 7, 14, 21 and 28 after ovulation. We also investigated expression of IGF1, IGF2 and their receptors 6 and 11 ...
Almadhidi J, Seralini GE, Fresnel J, Silberzahn P, Gaillard JL.Estrogens are the major steroids produced by equine gonads. To identify the cells responsible for estrogen synthesis, an antiserum against purified equine testicular cytochrome P450 aromatase was produced in rabbits. The reactivity and specificity of the antiserum were assessed by ELISA, immunoblot analysis, and immunoneutralization studies. Immunofluorescence microscopy demonstrated that in the male gonad, cytochrome P450 aromatase (P450arom) was localized in the interstitial tissue, whereas, under the experimental conditions used, the Sertoli and germ cells did not show any specific staining...
Smith KC, McGladdery AJ, Binns MM, Mumford JA.To evaluate transabdominal ultrasound-guided amniocentesis for detection of equid herpes-virus 1 (EHV-1)-induced fetal infection in utero. Methods: 4 Welsh Mountain mares. Methods: Pregnant mares were inoculated intranasally with EHV-1 during the ninth month of gestation. Amniocentesis was initiated on postinoculation day (PID) 12, and was performed at 2- to 3-day intervals in standing mares under deep sedation. Amniotic fluid samples were tested by virus isolation (VI), polymerase chain reaction (PCR), and immunoperoxidase cytologic examination (IC) for detection of EHV-1. Results: Exposure t...
Tydén E, Tallkvist J, Tjälve H, Larsson P.P-glycoprotein (P-gp) is an important drug transporter, which is expressed in a variety of cells, such as the intestinal enterocytes, the hepatocytes, the renal tubular cells and the intestinal and peripheral blood lymphocytes. We have studied the localization and the gene and protein expression of P-gp in these cells in horse. In addition we have compared the protein sequence of P-gp in horse with the protein sequences of P-gp in several other species. Real time RT-PCR and Western blot showed gene and protein expression of horse P-gp in all parts of the intestines, but there was no strict cor...
Aleman M, Scalco R, Malvick J, Grahn RA, True A, Bellone RR.Deleterious genetic variants are an important cause of skeletal muscle disease. Immunohistochemical evaluation of muscle biopsies is standard for the diagnosis of muscle disorders. The prevalence of alleles causing hyperkalemic periodic paralysis (HYPP), malignant hyperthermia (MH), polysaccharide storage myopathy 1 (PSSM1), glycogen branching enzyme deficiency (GBED), myotonia congenita (MC), and myosin heavy chain myopathy (MYHM) in horses with muscle disease is unknown. Archived slides processed for immunohistochemical analysis from 296 horses with muscle disease were reviewed blinded and c...
Cian F, Tyner G, Martini V, Comazzi S, Archer J.A 16-year-old, Irish Draft mare was admitted to the referring veterinarian for an annual health check. A mild generalized lymphadenomegaly was noted. Rectal palpation and transrectal ultrasonographic examination revealed prominent mesenteric lymph nodes. A transcutaneous abdominal ultrasonographic evaluation was unremarkable. A CBC revealed a marked leukocytosis (63.06 × 10(3)/μL) and lymphocytosis (58.2 × 10(3)/μL) due to increased numbers of small lymphocytes. No evidence of anemia or thrombocytopenia was found and neutrophil counts were low-normal. Cytologic examination of fine-needle a...
Chiavaccini L, Hassel DM, Shoemaker ML, Charles JB, Belknap JK, Ehrhart EJ.The black walnut extract (BWE) model of equine laminitis is associated with a systemic inflammatory response manifest by increased expression of inflammatory cytokines in the lungs and liver as well as the laminae. The specific role of the gastrointestinal tract in development of this response is unclear and is of utmost importance, as gastrointestinal disease and laminitis are intimately related. We investigated calprotectin expression and epithelial and endothelial apoptosis in the colon of horses exposed to orally administered BWE. Sections of colon from 19 horses including 7 controls not e...
Rapacz-Leonard A, Leonard M, Chmielewska-Krzesińska M, Paździor-Czapula K, Janowski T.Major histocompatibility protein class I (MHC-I) is believed to be expressed in the horse allantochorion only in limited areas at limited times. However, its expression has only been investigated in early pregnancy with non-quantitative techniques that cannot reliably detect small amounts of protein. To quantify the relative expression of MHC-I in the allantochorion and endometrium during days 90-240 of pregnancy (PREG), parturition with physiological delivery of fetal membranes (PHYS), and parturition with retention of these membranes (FMR). Also, to visualize protein expression and determine...
Furuoka H, Ito H, Hamada M, Suwa T, Satoh H, Itakura C.The endocrine cell components in the pancreatic islets of the following 4 pancreatic regions of the horse were investigated by immunohistochemical methods: lobus pancreatis sinister (left lobe); lobus pancreatis dexter (right lobe); and 2 regions of Corpus pancreatis (body), the duodenal lobe which lies along the cranial duodenal flexure and descending duodenum, and the intermediate lobe which is situated around the portal vein. The islets in the left and intermediate lobes contained a central mass of glucagon cells surrounded by insulin cells, a few somatostatin cells and sporadic pancreatic ...
Theoret CL, Barber SM, Gordon JR.To describe the localization of immunoreactive transforming growth factor (TGF)-beta1 in both normal skin and full-thickness dermal wounds of the limb and the thorax of the horse. Methods: Six full-thickness excisional wounds were created on the lateral aspect of one metacarpal region and on the midthoracic area of each horse. Sequentially collected tissue specimens from wound margins were assessed for TGF-beta1 expression by immunohistochemistry. Methods: Four horses (2 to 4 years of age). Methods: A neutralizing monoclonal anti-human TGF-beta1 antibody was used to detect the spatial expressi...
Waelchli RO, MacPhee DJ, Kidder GM, Betteridge KJ.The unusual hypotonicity of equine blastocyst fluid has prompted us to investigate the role of sodium- and potassium-dependent adenosine triphosphatase (Na+,K+-ATPase) in the process of fluid accumulation in the horse conceptus. Nine mares were used for the experiments. Reverse transcriptase polymerase chain reaction was conducted on two sets of five conceptuses recovered between 12 and 28 days (+/- 1 day) after ovulation. Messenger RNAs encoding the alpha1 and beta1 subunit isoforms of Na+,K+-ATPase were detected in all embryonic tissues examined. Western blot analysis showed that alpha1 and ...
Barreto RSN, Romagnolli P, Mess AM, Rigoglio NN, Sasahara THC, Simões LS, Fratini P, Matias GSS, Jacob JCF, Gastal EL, Miglino MA.In horses, pregnancy is characterized by high levels of maternal estrogens that are produced largely by the interstitial tissue inside the gonads of the offspring, associated with a physiological gonadal hyperplasia, that is uncommon in other species. However, a detailed structural-functional understanding of the early stages of gonadal development and hyperplasia has remained elusive in horse pregnancy because of the lack of substantial data. The goal of this study was to describe the genital organs' development in 19 early horse embryos and fetuses (days 20-140 of gestation) of both sexes by...
Hamada M, Oyamada T, Yoshikawa H, Yoshikawa T, Itakura C.The histopathological development of equine cutaneous papillomas was studied in 78 warts naturally occurring in 50 one to 3-year-old Thoroughbred or Arab horses and in 54 warts experimentally induced in three 2-year-old Thoroughbreds. Lesions in the natural cases were categorized into three phases, growth, development and regression. Main lesions of the growing phase were marked hyperplasia of the basal cells and mild to moderate acanthosis, hyper- and parakeratosis with a few intranuclear inclusion bodies (IIB) which were positive with anti-bovine papillomavirus serum. In the developing phase...
Crump AL, Davis W, Antczak DF.A cell surface molecule of equine T lymphocytes was identified and characterized using a mouse monoclonal antibody, HT23A. The molecule was detected on all T cells but not on other cells in peripheral blood, with the possible exception of a small subpopulation (about 5%) of B cells, as assessed by indirect immunofluorescence and flow cytometry. HT23A labelled T cell areas of horse lymph nodes and spleen when used in an indirect immunoperoxidase assay on frozen sections. Macrophages and neutrophils were not labelled by the antibody nor were frozen sections of horse liver, kidney, or brain. HT23...
Hussein H, Boyaka P, Dulin J, Russell D, Smanik L, Azab M, Bertone AL.Selective inhibition of Cathepsin K (CatK) has a promising therapeutic potential for diseases associated with bone loss and osseous inflammation, such as osteoarthritis, periodontitis, and osteoporosis. In horses, stress-related bone injuries are common and accompanied by bone pain and inflammation resulting in excessive bone resorption and periostitis. VEL-0230 is a highly selective inhibitor of CatK that significantly decreased bone resorption and increased bone formation biomarkers. The goal of this study was to demonstrate the presence of CatK in equine bone and a simultaneous influence on...
Lee GKC, Tessier L, Bienzle D.The Salivary Scavenger and Agglutinin (SALSA) protein is an innate immune protein with various alleged functions, including the regulation of inflammation and tissue remodeling. Transcriptomic studies of severe equine asthma (SEA) showed downregulation of the gene encoding SALSA in bronchial epithelium of asthmatic compared to non-asthmatic horses. This study aimed to characterize expression of SALSA in equine tissues by immunohistochemistry (IHC), corroborate potential differences in epithelial gene expression between asthmatic and non-asthmatic horses, and assess the structure of equine SALS...
McD￮ LA, Anderson GI, Wright GM, Ryan DA.Bone cell cultures were evaluated to determine if osteogenic cell populations at different skeletal sites in the horse are heterogeneous. Osteogenic cells were isolated from cortical and cancellous bone in vitro by an explant culture method. Subcultured cells were induced to differentiate into bone-forming osteoblasts. The osteoblast phenotype was confirmed by immunohistochemical testing for osteocalcin and substantiated by positive staining of cells for alkaline phosphatase and the matrix materials collagen and glycosaminoglycans. Bone nodules were stained by the von Kossa method and counted....
