Histological changes in the nasal ventral conchae of piglets infected with Bordetella bronchiseptica.

Piglets infected intranasally with Bordetella bronchiseptica were injected with two fluorochrome markers. Transverse sections of undecalcified nasal conchae (cut between the third incisor and the third premolar teeth) were examined by microradiography and fluorescence microscopy; surface-stained sections were evaluated by light microscopy. The fluorescent surface of the nasal ventral conchae from the infected piglets was increased as compared with the controls. This was due to an increased amount of fluorescent mineralization fronts as well as to the presence of abnormal fluorescent areas within trabeculae. Trabecular mineral content of the microradiographs was irregular and varied from hypo- to hypermineralized. When compared with the corresponding surface-stained sections, no correlation could be made between the mineral content and the type of tissue. These findings suggest that an increased number of osteoblasts which secrete prebone matrix but are modified so that mineralization does not occur normally.     

Upregulation of mRNA of interleukin-1 and -6 in subchondral cystic lesions of four horses

This study investigated the potential association of interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) in subchondral cystic lesions (SCL) in horses. With the technique of in situ hybridisation in paraffin sections of fibrous tissue of SCL and quantitative real-time PCR in fresh frozen fibrous tissue and undecalcified bone sections of SCL embedded in acrylic resin, upregulation of mRNA of both cytokines could be demonstrated. mRNA of IL-1beta was upregulated at the periphery of the cystic lesion adjacent to normal bone, whereas IL-6 mRNA was upregulated within the fibrous tissue found within the centre of the SCL. It was concluded that both cytokines are associated in pathological bone resorption observed in SCL and, in combination with increased production of prostaglandin E2, may be responsible for the slow healing, maintenance or further expansion of the cystic lesions.     

Shortening of the Bovine Tongue According to Regulation (EC) 999/2001 is not Complying with the Current Legal Definition of Specified Risk Material – a Macroscopical and Histological Preliminary Study

The full elimination of all specified risk material (SRM) in food of animal origin is crucial for consumer protection and is of high priority in inner EU trade. Among other tissues, the tonsils of cattle are considered as SRM. The aim of this study was to evaluate whether the ‘cut at the back of the tongue just before the tongue bones’ required by EC regulation is sufficient to remove tonsils and lymphatic tissue completely. Eight skulls from cattle were collected for the simulation of a vertical cut according to the EC regulation and the detection of the target at the back of the tongue. Further, specimens of the lingual mucosa were cut out from two tongues and examined microscopically. The most caudal of these specimens was from the macroscopically visible part of the lingual tonsil. The most rostral specimen contained the most caudal Papilla vallata. Simulation of the obligatory ventro‐dorsal cut yielded hits at varying locations on the dorsal surface of the tongue, sometimes including tissue of the lingual tonsil. Histological examination of the lingual mucosa gave clear evidence that lymphatic tissue resembling the tissue of a tonsil in terms of its histological organization and infiltration of the mucosal epithelium could even be found in areas with no macroscopically visible lingual tonsils.     

Shortening of the bovine tongue according to regulation (EC) 999/2001 is not complying with the current legal definition of specified risk material - a macroscopical and histological preliminary study

The full elimination of all specified risk material (SRM) in food of animal origin is crucial for consumer protection and is of high priority in inner EU trade. Among other tissues, the tonsils of cattle are considered as SRM. The aim of this study was to evaluate whether the 'cut at the back of the tongue just before the tongue bones' required by EC regulation is sufficient to remove tonsils and lymphatic tissue completely. Eight skulls from cattle were collected for the simulation of a vertical cut according to the EC regulation and the detection of the target at the back of the tongue. Further, specimens of the lingual mucosa were cut out from two tongues and examined microscopically. The most caudal of these specimens was from the macroscopically visible part of the lingual tonsil. The most rostral specimen contained the most caudal Papilla vallata. Simulation of the obligatory ventro-dorsal cut yielded hits at varying locations on the dorsal surface of the tongue, sometimes including tissue of the lingual tonsil. Histological examination of the lingual mucosa gave clear evidence that lymphatic tissue resembling the tissue of a tonsil in terms of its histological organization and infiltration of the mucosal epithelium could even be found in areas with no macroscopically visible lingual tonsils.     

Structure of Vomeronasal Organ (Jacobson organ) in Male Camelus Domesticus Var. dromedaris persica

The vomeronasal organ (VNO) is a tubular structure in the roof of nasal cavity. The important role of this organ is olfaction of sexual odour. In this study, position, anatomical structure and histology of VNO in Iranian camels (camelus domesticus var. dromedaris persica) were determined. Fourteen healthy male camel heads were collected from an industrial slaughterhouse in Tehran, Iran, for anatomical and histological studies (seven each). The length of VNO and width of dental pad and the number and width of palatine crests were measured. For anatomical studies, the mandible was removed, and maxilla and nasal cavity was cut longitudinally and transversely. For histological studies, the mandible was removed, and first 0.5 cm of initial part of VNO was cut. Then, nasal cavity was cut in some segments with 2 cm thickness. The width of VNO was 3.85 ± 0.31 cm and 1.57 ± 0.18 cm in front and distal parts, respectively. The length of VNO was 15.61 ± 0.59 cm. In histological examinations, VNO was surrounded by J‐shape hyaline cartilage. The lining epithelium of lateral wall of VNO was originated from respiratory epithelium, while it had an olfactory epithelium origin in the medial wall. Lamina propria and tunica submucosa were a cavernous connective tissue with seromucous gland with abundant of serous secretory units. The lumen of VNO opens into nasal cavity. The presence of olfactory epithelium found in our study indicates an important role for VNO in pheromone perception and beginning of sexual behaviour.     

Evaluation of biocompatible osteoconductive polymer shelf arthroplasty for the surgical correction of hip dysplasia in normal dogs.

Biocompatible osteoconductive polymer (BOP) shelf arthroplasty was performed on ten nondysplastic dogs, divided into five groups. Each group was evaluated at 6, 13, 17, 26 or 39 weeks postsurgery. Evaluation consisted of clinical, radiological and histological studies. The dogs were injected with three fluorochrome markers, 28 days, 14 days and 6 hours before euthanasia. Transverse sections of undecalcified arthroplasty site were examined by microradiography and fluorescence microscopy; surface-stained sections were evaluated by light microscopy. The BOP shelf arthroplasty was not technically difficult. Minimal mineralization of the shelf was noted by radiography, 26 and 39 weeks postop. A moderate to large amount of fibrous mature connective tissue was observed around the BOP fibers throughout the study. Bone ingrowth occurred around the BOP fibers, but was minimal within them. This osseous proliferation of the arthroplasty was very slow to take place; it was first noted microscopically 17 weeks postsurgery and was still minimal 39 weeks after surgery. These findings suggest that there may be interference to the osteoconductive properties of BOP by fibrous tissue. Ossification of the shelf arthroplasty was too unsatisfactory to recommend its use for the treatment of canine hip dysplasia.     

Dual Sarcocystis neurona and Toxoplasma gondii infection in a Northern sea otter from Washington state, USA

Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.     

Haematopoietic necrosis in a goldfish (Carassius auratus) associated with an agent morphologically similar to herpesvirus

One of 14 goldfish (Carassius auratus) died 4 weeks after purchase and was investigated by necropsy and histological examination. Routine formalin fixation of the goldfish was followed by histopathology. Formalin fixed spleen and kidney from the fish was further processed by embedding in epoxy resin and examined by transmission electron microscopy (EM). Severe, diffuse necrosis of haematopoietic tissue in the spleen, thymus and kidney and severe, diffuse hyperplasia in the gill epithelial cells were seen. In the spleen there was severe, diffuse necrosis of lymphocytes and many nuclei with marginated chromatin and intranuclear inclusions were scattered throughout the necrotic tissue. EM of affected tissues demonstrated intranuclear particles morphologically similar to herpesvirus. The presence of an agent similar to a herpesvirus in a goldfish with severe haematopoietic necrosis suggests that the herpesvirus responsible for haematopoietic necrosis in cyprinid species throughout the world has entered the goldfish population in Australia.     

The effects of two different decalcification procedures on size and structure of embryonic epithelial tissue in objects prepared for light microscopy

Electrolytic decalcification is a very fast and effective method for removing calcium compounds from bones with minimum damage to tissues. Changes of dimension of tissues in histological sections prepared from specimens decalcified by immersion in a formic acid solution and sections prepared from specimens treated in an electrolytic decalcifier were studied. Heads of mouse foetuses were cut in half, decalcified by one of the above-mentioned methods and embedded in histowax. Dimensional changes of skin, tongue and nasal epithelia in histological sections were evaluated by t-test. Significant shrinking and other unwanted effects of decalcification, such as acidophilia of nuclei, were found in objects decalcified by both methods. No significant differences in the effects of the two methods on tissue dimensions were demonstrated. It is concluded that both decalcification methods are equivalent from the qualitative point of view.     

Histological and immunohistochemical investigations of ovarian interstitial glands during non‐breeding season in camels (Camelus dromedarius)

The aim of this was to investigate the histology and immunohistochemistry of interstitial glands during non‐breeding season in camel ovaries. A total of 21 mature, non‐pregnant and apparently healthy camels aged between 8 and 12 years were slaughtered. The ovaries were removed within 15 min, cleaned from adipose tissue, weighted and examined grossly. The histological preparation was made, and then, the blocks were cut at 3–5 microns thickness and stained by H&E for histological examinations. Moreover, some sections were stained with Sudan Black for lipid detection. Immunohistochemical analysis of paraffin‐embedded ovarian tissues was performed to detect the localization of S‐100, vimentin, progesterone receptors (PR) and oestrogen receptors (ER). Immunoreactive signals were detected using UltraVision Detection System. The results revealed that the interstitial glands were located in the cortical region and they were arranged in various arrangements either single, in couple or in groups rich in lipid droplet. All interstitial gland arrangements were enclosed by connective tissue capsules containing fibroblasts and collagenous fibres separated them from the surrounding ovarian structures. Both interstitial glands and their surrounding CT were penetrated by several blood vessels. There was a strong immunoreactive signal for S‐100 in the nuclei of interstitial cells, and no signals were detected either in cells of the interstitial glands or their connective tissue with PR. We could conclude that the interstitial gland is distinct in ovary of camel and further studies are needed to elucidate its rule in steroid synthesis.     

Donkey dental anatomy. Part 2: Histological and scanning electron microscopic examinations

Ten normal cheek teeth (CT) were extracted at post mortem from donkeys that died or were euthanased for humane reasons. Decalcified histology was performed on three sections (sub-occlusal, mid-tooth and pre-apical) of each tooth, and undecalcified histology undertaken on sub-occlusal sections of the same teeth. The normal histological anatomy of primary, regular and irregular secondary dentine was found to be similar to that of the horse, with no tertiary dentine present. Undecalcified histology demonstrated the normal enamel histology, including the presence of enamel spindles. Scanning electron microscopy was performed on mid-tooth sections of five maxillary CT, five mandibular CT and two incisors. The ultrastructural anatomy of primary and secondary dentine, and equine enamel types-1, -2 and -3 (as described in horses) were identified in donkey teeth. Histological and ultrastructural donkey dental anatomy was found to be very similar to equine dental anatomy with only a few quantitative differences observed.     

Histology of lamb epididymal development

To describe the distribution of the histological regions and their morphometry during epididymal development, 10 Corriedale lambs were castrated monthly from 90 to 180 days of age (n = 24), and their testes and epididymides were weighed. All animals were weighed monthly. Epididymides were divided into caput, corpus and cauda, and cut sagitally so that sections included all the length of the organ. The diameter of the epididymal duct, the smooth muscle depth and the epididymal epithelium height were measured. The quantitative histology of the ovine epididymal development was described. Epididymal development advanced from caput to cauda. The distribution of the histological regions varied according to epididymal weight. Transient histological regions were found during epididymal development. The present results indicate a new way of epididymal development in sheep, which courses from caput to cauda with transient histological regions appearing, varying in location and disappearing during ovine epididymis development.     

Necrotic hepatitis due to Clostridium perfringens infection in newly hatched broiler chicks

Multiple necrotic hepatitis lesions of 5 newly hatched broiler chicks in three flocks derived from two hatcheries were examined pathologically. The livers were brittle, and multiple yellowish or green foci were scattered on the surface and cut surface. The main histological finding was well demarcated multi-focal necrosis in the liver. Many Gram-positive large bacilli that reacted positively with polyclonal anti-Clostridium perfringens serum were observed in necrotic areas.     

Effect of exercise on the vascular pattern in the bone extremities of broiler fowl

The vascular morphology of the proximal femur, tibiotarsus and tarsometatarsus was studied in growing broiler chicks. A carousel was used to exercise one group of 24 birds for four periods of 15 minutes each day. A second group (controls) were not exercised. Some birds were killed during the course of the experiment, and the remainder after 25 days of exercise when they were 33 days old. After killing the limbs were perfused and the bone extremities cleared. The bone extremities were then cut into 1 mm thick slabs and examined. There were abnormalities of the physis and physeal vasculature in 18 (25 per cent) of the bone extremities from the exercised birds and in 24 (40 per cent) of the bone extremities from the unexercised (control) birds. The low level of activity in the unexercised fowls of the present study appeared to contribute to these abnormalities.     

Vascular characteristics of the cartilage and subchondral bone of the distal radial epiphysis of the young foal

The vascular features of the distal epiphysis of the radius of 27 foals aged from 3 weeks premature to 120 days postpartum were determined. The limbs were perfused with barium, and the distal radius was sawn into sagittal slabs which were decalcified, cut into thin slices and radiographed. More arteries approached areas of thick cartilage than thin cartilage. In thick cartilage, vessels in a lattice network were observed, and adjacent to these vessels was sinusoidal filling in the epiphyseal subchondral bone, which had a similar pattern to sinusoidal filling in the metaphysis. The sinusoidal filling adjacent to thick cartilage was at the predisposition site for epiphyseal osteomyelitis lesions in foals. This particular type of bone infection occurs commonly in the foal, but much less commonly in other species. The vascular features of the immature epiphysis may account for the predominance of epiphyseal osteomyelitis in the foal.     

Laparoscopic cryptorchidectomy and ovariectomy in standing horses using the EnSeal® tissue-sealing device

In the present series of cases, 8 laparoscopic cryptorchidectomies and 4 laparoscopic ovariectomies were carried out in sedated standing horses. Sedation involved a lesser anaesthesiological risk than does general anaesthesia. As compared to laparotomic exposure, the minimally invasive laparoscopic intervention provided better visualisation, shorter operative time and faster recovery. The blood vessels supplying the testes and ovaries and the suspensory ligaments of the organs were sealed and cut with EnSeal?, an adaptive bipolar electrosurgical blood vessel- and tissue-sealing device. The clinical use of the blood vessel- and tissue-sealing device proved to be successful in all cases. Gradual separation of the intact tissue from the treated, compacted, dehydrated and homogenised tissue areas and occlusion of the lumen of blood vessels treated with the device could be observed in all histological sections. To the best of our knowledge, this is the first report on the use of EnSeal? for laparoscopic cryptorchidectomy and ovariectomy in horses.     

Epiphyseal cartilage canal blood supply to the metatarsophalangeal joint of foals

Reasons for performing study: It is presently unknown whether cartilage ischaemia plays any part in the pathogenesis of osteochondral fragmentation within the equine metatarsophalangeal joint, as no detailed studies on microcirculation in the area have been reported. Objective: To describe the developmental pattern of the blood supply to the epiphyseal growth cartilage in the metatarso‐phalangeal joint of foals. Methods: Eight Standardbred foals were sacrificed between birth and age 7 weeks to undergo a barium perfusion procedure to demonstrate vessels within growth cartilage canals of one hindlimb. The metatarso‐phalangeal joint was cleared in methyl salicylate and perfused vessels studied in the intact bones. The bones were sawed into 5 mm thick slabs, decalcified and radiographed. Selected slabs were cleared in methyl salicylate for a second time and examined at low magnification. The dorsal half of the sagittal ridge of the distal third metatarsal bone and the plantar half of the proximal phalanx were examined histologically. Results: Regions of the epiphysis with thick cartilage contained a greater number of perfused vessels than regions with thin cartilage. The cartilage canal vessels were oriented either parallel or perpendicular to the underlying ossification front. Cartilage canal vessels were incorporated into the ossification front during growth and became reliant on a subchondral arterial source. Macroscopically visible lesions were not detected in the current group of foals. On histological examination, pathological changes consisting of an area of chondronecrosis surrounded by fibrovascular granulation tissue were found in sections from the lateral proximo‐plantar eminence of the proximal phalanx in the 7‐week‐old foal. Conclusion: The same anatomical feature (traversing the ossification front to enter cartilage canals) reported to render vessels vulnerable to failure in the tarsus was also present in the metatarso‐phalangeal joint of foals. Potential relevance: Osteochondrosis may occur by the same pathogenetic mechanism in the metatarso‐phalangeal joint as in the tarsus of foals.     

Metastasizing seminal vesicle adenocarcinoma in a Wistar rat

An adenocarcinoma in the seminal vesicles of a 15-month-old male Wistar rat from a 30-month inhalation study is described. The rat was killed because of cachexia, apathy and a large palpable mass in the abdominal cavity. Macroscopic examination of the abdominal cavity revealed a 3.8 cm x 3.2 cm yellow-grey to pink mass, firm to soft in consistency. The cut section revealed cystic spaces. Histologically, the mass consisted of epithelial cells arranged in glandular and solid patterns with abundant amounts of connective tissue. Epithelial tumour cells were round-to-cylindrical with round-to-oval basophilic nuclei and one or two prominent nucleoli and a distinct eosinophilic cytoplasm. The glandular structure contained clusters of macrophages in their lumen with eosinophilic cytoplasm and indented nuclei. Extensive necrosis and reactive inflammation were present. The histological features of the small nodules in the pancreas and on the surface of the liver, rectum and urinary bladder resembled those of the primary tumour in the seminal vesicles. Based on these criteria, the neoplasm (mass) was diagnosed as an adenocarcinoma of the seminal vesicles. The immunohistological examination confirmed the diagnosis, i.e. immunostaining was positive for cytokeratins (4, 7, 14, 15, 18, and 19), vimentin, PCNA, and ED(1).     

An equine cryptorchid with testicular and ovarian tissues.

Cytogenetic and histological studies were carried out on an intersex horse which was diagnosed clinically as a cryptorchid. Surgery confirmed the horse to be a bilateral abdominal cryptorchid and histological examination revealed ovarian tissue associated with the left epididymis. Chromosome analysis of cultured cells from testicular tissue, ovarian tissue and skin revealed 64-XX and 64-XY make-up, the left gonad containing a greater preponderance of XX cells over XY cells. The external characteristics and behaviour of the horse were indistinguishable from that of a "routine" cryptorchid. Other cases of equine intersexes are reviewed and theories for the discrepancies between genetic, gonadal and phenotypic sex are discussed.     

Effect of Bovine Ovarian Tissue Vitrification on the Structural Preservation of Antral Follicles

This study was performed to evaluate the structural preservation of antral follicles after bovine ovarian tissue vitrification using histological analysis. Ovaries (n = 30) of slaughtered cows were cut into small fragments using a scalpel blade, and the ovarian tissues were randomly assigned to vitrification using 15% dimethyl sulphoxide (DMSO) and 15% ethylene glycol (EG) and fresh tissues (control) groups. For histological evaluations, fresh and post‐thawing ovarian tissues were immediately fixed, serially sectioned into 5‐μm sections and stained with haematoxylin and eosin (H&E). Nine serial sections per fragment were subjected for morphological assessment. The diameter of the antral follicles was determined and classified into four groups: 1 (≤1 mm), 2 (>1–2 mm), 3 (>2–3 mm) and 4 (>3–4 mm). Then, follicular morphology was evaluated in relation to atresia and categorized into seven grades: Grade A (healthy follicle); Grades B, C and D (early atresia); Grades E and F (moderate atresia); and Grade G (advanced atresia). The results revealed that small diameters of antral follicles (1 and 2 mm) were more susceptible for cryoinjury. The normal follicular morphology (Grade A) was not affected by vitrification throughout follicle diameters. Nevertheless, some damage features were monitored after vitrification. In conclusion, the morphological structure of bovine antral follicles could be successfully preserved by ovarian tissue vitrification.