Student No. 9404705H MDent Research Report School of Oral Sciences / Expression of the E-cadherin/β-catenin complex in oral squamous cell carcinoma and its correlation with histomorphology and metastasis. The immunohistochemical expression of E-cadherin and β-catenin was examined in 30 primary oral squamous cell carcinomas in patients with (n=19) and without (n=11) nodal metastasis, as confirmed on histopathological examination of the resected regional lymph nodes. The corresponding primary and nodal metastases tissue samples were available for 17 patients. The 30 primary carcinomas were histologically graded according to the invasive tumour front grading system and by conventional Broders’ criteria. None of the 30 primary carcinomas showed homogenous, membranous E-cadherin and β-catenin expression when compared to the normal oral squamous epithelium. Staining was heterogeneous in 73% (22/30) and in 77% (23/30) of the primary carcinomas stained for E-cadherin and β-catenin respectively. There was a highly significant reduction (P<0,001) of both E-cadherin and β- catenin expression with progression from the well-differentiated areas to the less differentiated tumour cells at the invasive tumour front. At the invasive tumour front, however, irrespective of the nodal status and invasive tumour front grading score, 28/30 (93%) tumours showed loss of E-cadherin expression. Loss of β-catenin expression was recorded in 22/30 (73%) cases. These findings indicate that E-cadherin and β-catenin play a key role in the loss of differentiation of tumour cells in oral squamous cell carcinoma and while they may be permissive for metastasis, in isolation, E-cadherin and β-catenin are probably not predictive of metastatic potential in oral squamous cell carcinoma.

No description available.

Histological methods to estimate skeletal age at death, in forensic cases, are an alternative to the more traditional gross morphological methods. Most histological methods utilize counts of bone type within a given field for their estimation. The method presented in this paper uses the percentage area occupied by unremodeled bone to estimate age. The percentage area occupied by unremodeled bone is used in a linear regression model to predict skeletal age at death. Additionally, this method uses digital software to measure area rather than the traditional technique in which a gridded microscope is used to estimate area. The clavicle was chosen as a sample site since it is not a weight bearing bone and has little muscular insertion. These factors reduce the variation seen as a result of differences in lifestyle or activity pattern.

The intestinal tract of salmonids provides a dynamic interface that not only mediates nutrient uptake but also functions as the first line of defence against ingested pathogens. Exposure of the immune system to beneficial microorganisms and different dietary immunostimulants via the intestine has been shown to prime the immune system and help in the development of immune competence. Furthermore, the morphology and function of teleostean intestines are known to respond to feed components and to ingested and resident bacterial communities. Histological appraisal is still generally considered to be the gold standard for sensitive assessment of the effects of such dietary modulation. The aim of the present study was to improve understanding of salmonid intestinal function, structure and dynamics and to use the knowledge gained to develop a model for analysis, which would allow intestinal health to be assessed with respect to different intestinal communities and feed components. Virtual histology, the process of assessing digital images of histological slides, is gaining momentum as an approach to supplement traditional histological evaluation methodologies and at the same time, image analysis of digitised histological sections provides a practical means for quantifiable assessment of structural and functional changes in tissues, being both objective and reproducible. This project focused on the development of a rapid, practical analytical methodology based on advanced image analysis, that was able to measure and characterise a range of features of the intestinal histology of Atlantic salmon in a quantitative manner. In the first research chapter, the development of a novel histological assessment system based upon advanced image analysis was described, this being developed with the help of a soybean feed model known to induce enteropathy in Atlantic salmon. This tool targeted the evaluation of the extent of morphological changes occurring in the distal intestine of Atlantic salmon following dietary modulation. The final analytical methodology arrived at, could be conducted with minimal user-interaction, allowing rapid and objective assessment of 12 continuous variables per histological frame analysed. The processing time required for each histological frame was roughly 20-25 min, which greatly improved the efficiency of conducting such a quantitative assessment with respect to the time taken for a subjective semi-quantitative alternative approach. Significant agreement between the fully automated and the manual morphometric image segmentation was achieved, however, the strength of this quantitative approach was enhanced by the employment of interactive procedures, which enabled the operator / observer to rectify preceding automated segmentation steps, and account for the specimen’s variations. Results indicated that image analysis provided a viable alternative to a pathologist’s manual scoring, being more practical and time-efficient. In the second research chapter, feeding Atlantic salmon a high inclusion level of unrefined SBM (25 %) produced an inflammatory response in the distal intestine as previously described by other authors. The model feed trial successfully generated differentiable states, although these were not, for the most part, systemically differentiable through the majority of standard immunological procedures used, being only detectable morphologically. Quantitation of morphometric parameters associated with histological sections using the newly developed image analysis tool successfully allowed identification of major morphological changes. Image analysis was thus shown to provide a powerful tool for describing the histomorphological structure of Atlantic salmon distal intestine. In turn, the semi-automated image analysis methods were able to distinguish normal intestinal mucosa from those affected by enteritis. While individual parameters were less discriminatory, use of multivariate techniques allowed better discrimination of states and is likely to prove the most productive approach in further studies. Work described in the third research chapter sought to validate the semi-automated image analysis system to establish that it was measuring the parameters it was purported to be measuring, and to provide reassurance that it could reliably measure pre-determined features. This study, using the same sections for semi-quantitative and quantitative analyses, demonstrated that the quantitative indices performed well when compared to analogous semi-quantitative descriptive parameters of assessment for enteritis prognosis. The excellent reproducibility and accuracy performance levels indicated that the image analysis system was a useful and reliable morphometric method for the quantification of SB-induced enteritis in salmon. Other characteristics such as rapidity, simplicity and adaptability favour this method for image analysis, and are particularly useful where less experienced interpreters are performing the analysis. The work described in the fourth research chapter characterised changes in the morphology of the intestinal epithelial cells occurring as a result of dietary modulation and aspects of inflammatory infiltration, using a selected panel of enzyme and IHC markers. To accomplish this, image analysis techniques were used to evaluate and systematically optimise a quantitative immunolabelling assessment protocol. Digital computer-assisted quantification of labelling for cell proliferation and regeneration; programmed cell death or apoptosis; EGCs and t-cell like infiltrates; mobilisation of stress-related protein regenerative processes and facilitation of nutrient uptake and ion transport provided encouraging results. Through the description of the intestinal cellular responses at a molecular level, such IHC expression profiling further characterised the inflammatory reaction generated by the enteropathic diet. In addition, a number of potential diagnostic parameters were described for fish intestinal health e.g. the relative levels of antigenicity and the spatial distribution of antigens in tissues. Work described in the final research chapter focused on detailed characterisation of intestinal MCs / EGCs in order to try to elucidate their functional role in the intestinal immune responses. Through an understanding of their distribution, composition and ultrastructure, the intention was to better characterise these cells and their functional properties. The general morphology, histochemical characteristics and tissue distribution of these cells were explored in detail using histochemical, IHC and immunogold staining / labelling, visualised using light, confocal and TEM microscopy. Despite these extensive investigations, their physiological function and the content of their granules still remain somewhat obscure, although a role as immunodulatory cells reacting to various exogeneous signals through a finely regulated process and comparable to that causing the degranulation of mammalian MCs is suggested. The histochemical staining properties demonstrated for salmonid MCs / EGCs seem to resemble those of mammalian mucosal mast cells, with both acidophilic and basophilic components in their granules, and a granule content containing neuromodulator / neurotransmitter-peptides such as serotonin, met-enkephalin and substance-p. Consequently, distinguishable bio-chromogenic markers have been identified that are of utility in generating a discriminatory profile for image analysis of such cells.

Le remodelage osseux est un processus qui permet le renouvellement du tissu osseux tout au long de la vie des individus (Toppets et al. 2004). Il est bien connu que le remodelage est influencé à la fois par l’environnement mécanique (charges, activités) et par les besoins métaboliques (Pearson et Lieberman 2004; Rosas et Martinez-Maza 2010). Cependant, les effets des charges mécaniques sur le remodelage osseux restent encore peu compris (Lad and al. 2016; Pfeiffer and al 2006). Cette étude a pour but d’évaluer les réponses microscopiques des os aux charges mécaniques. L’échantillon étudié correspond à des paires de seconds métacarpes, issues de deux populations d’origine géographique distinctes (n=103, 55 Euro-Canadiens et 48 Inuits). À partir de section en coupe provenant de la mi-diaphyse, les lames minces ont été analysées selon quatre quadrants anatomiques : antérieur, médial, postérieur et latéral. Afin de contrôler les facteurs non mécaniques qui influencent le remodelage (tels l’âge) l’asymétrie entre les paires des métacarpes est calculée pour toutes les variables étudiées. Les charges sont estimées par les valeurs d’asymétrie de trois variables biomécaniques macroscopiques : Imax, Imin et J. Les asymétries de la densité de population des ostéons (OPD), de l’aire moyenne des ostéons et des canaux de Havers furent calculées pour estimer la réponse osseuse microscopique. De plus, il fut testé l’effet de la densité de population des ostéons sur leur aire moyenne. Les résultats démontrent que la densité d’ostéons diminue pour certains groupes (chez les hommes de St Thomas, r = - 0,412 et les femmes Inuits r = -0,547), et que les aires moyennes des ostéons et des canaux de Havers augmentent dans le quadrant antérieur du métacarpe le plus chargé (chez St-Thomas r = 0,297). De plus, il existe une relation négative entre l’augmentation de la densité d’ostéons et leur aire moyenne, dans le quadrant postérieur des femmes de St Thomas (r = -0,496). En conclusion, les charges mécaniques ont un impact sur la microstructure de l’os, rendant possible l’étude des charges à travers l’analyse histomorphologique du tissu osseux. / Bone remodeling is the process by which the skeleton can be renewed throughout the life of individuals (Toppets and al. 2004). It is well known that bone remodeling is a function of both mechanical (loads, activities) and non-mechanical factors such as metabolic needs of the bone (Pierson and Lieberman 2004; Rosas and Martinez-Maza 2010). However, the effects of mechanical environment on bone remodeling still remain poorly understood (Lad and al. 2016; Pfeiffer and al. 2006). This study aims to evaluate the microscopic bone responses to mechanical loading. The sample analyzed represents pairs of second metacarpal from two genetically separated populations (n=103, 55 Euro-Canadiens and 48 Inuits). From mid-shaft sections, thin sections were analyzed using four anatomical quadrants: anterior, medial, posterior and lateral. In order to control the influence of non-mechanical factors on bone remodeling, the asymmetry between pairs of metacarpals is calculated for each variable studied. Mechanical loading is estimated from the asymmetry values of three macroscopic biomechanical variables: Imax, Imin and J. Besides, asymmetries of osteon population density (OPD), mean areas of osteons and Havers canals were measured to estimate the microscopic bone response. Furthermore, it was tested the effect of osteon population density on osteon area. Results show that osteon population density decreases in some groups (in St-Thomas men r = - 0,412 and Inuit women r = -0,547), and the mean area of osteon and Havers canals increase in the more loaded side (in St-Thomas r = 0,297). In addition, there is a negative relationship between increased density of osteons and their mean areas in the posterior quadrant in St-Thomas women (r = -0,496). In conclusion, mechanical loading seems to have an impact on bone microstructure, making possible the inference of mechanical loadings through the study of bone histomorphology.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This thesis was composed of three scientific papers. The first paper was the more comprehensive one. All necropsy and biopsy cases of mycoses and oomycosis diagnosed in domestic animals between 1990 and 2012 were analyzed. In the studied period, 29,686 exams (9,487 necropsy reports and 20,199 biopsy reports) performed at the Laboratório de Patologia Veterinária (LPV) of the Universidade Federal de Santa Maria (UFSM) were studied. Two hundred and thirty cases of mycosis or pythiosis (oomycosis) were found, being 179 cases (78%) of mycoses and 51 cases (22%) of pythiosis. The main diseases observed, in descending order of prevalence, were: pythiosis, candidiasis, aspergillosis, zygomycosis, dermatophytosis, mallasseziosis, cryptococcosis, megabacteriosis, and sporothrichosis. Pythiosis affected mainly horses and the mycosis affected mainly dogs and cats. The second article focused on the histomorphological and histochemical characteristics determinant for the histopathological diagnosis of this condition in dogs and cats. By the hematoxylin-eosin (HE) stain, the yeasts were round, with a central cell containing a nucleus, surrounded by a clear halo (usually non-stained capsule). The techniques of periodic Schiff acid (PAS), Grocott, and Fontana-Masson (FM) were utilized and demonstrated the wall of the yeast cells. The FM stain showed the melanin present in these cells. The Alcian blue and Mayer s mucicarmin stains showed mainly the yeast polysaccharide capsule. The diameter of the cells ranged from 1.67 to 10.00μm and the full diameter of the encapsulated yeasts varied between 4.17 e 34.16μm. Yeast buddings were better observed through the PAS stain and were narrow based, simple or multiple, mainly in the opposite poles of the cells, or forming chains. The third article emphasized an immunohistochemical (IHC) study of cases of aspergillosis and zygomycosis aiming to optimize the use of the IHC technique in the detection of Aspergillus spp. and zygomycetes in animal tissues. Two fungal-specific monoclonal antibodies were utilized in tissue fragments (formalin-fixed paraffin-embedded) previously diagnosed as aspergillosis or zygomycosis. Tissues were submitted to three different detection systems (two biotinilated and one nonbiotinilated). Both antibodies showed high specificity and sensitivity in the examined tissues. No cross-reactions were observed between the antibodies utilized and the agents evaluated (including cases of aspergillosis, zygomycosis, candidiasis, and pythiosis). However, nonspecific reactions were observed in hyphae of some cases, but were eliminated by mean of one of the detection systems used. The IHC technique showed to be a useful tool detecting and confirming aspergillosis and zygomycosis in this retrospective study. / Esta tese foi constituída de três partes que resultaram em três artigos científicos. O primeiro artigo foi o mais abrangente, onde todos os casos de micoses e pitiose diagnosticados em animais domésticos, provenientes de necropsias e biópsias entre 1990 e 2012, foram analisados. No período estudado foram revisados 9.487 protocolos de necropsias e 20.199 exames histopatológicos, totalizando 29.686 casos examinados no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV-UFSM). Do total de protocolos analisados, em 230 foram diagnosticadas micoses ou pitiose (oomicose), sendo 179 casos (78%) de micoses e 51 casos (22%) de pitiose. As principais doenças diagnosticadas, em ordem decrescente de prevalência, foram: pitiose, candidíase, aspergilose, zigomicose, dermatofitose, malasseziose, criptococose, megabacteriose e esporotricose. Os equinos foram os mais acometidos pela pitiose e os animais de companhia (cães e gatos) foram os mais acometidos pelas micoses. O segundo artigo enfocou as características histomorfológicas e histoquímicas determinantes no diagnóstico histopatológico da criptococose em cães e gatos. Pela técnica de hematoxilina-eosina (HE) as leveduras eram arredondadas, com célula central contendo um núcleo, circundada por um halo claro (cápsula geralmente não corada). As técnicas histoquímicas do ácido periódico de Schiff (PAS), Grocott e Fontana-Masson (FM) foram utilizadas e evidenciaram a parede das células das leveduras. Pelo FM observou-se a melanina presente nessas células. As técnicas do azul Alciano e da mucicarmina de Mayer evidenciaram principalmente a cápsula polissacarídica das leveduras. O diâmetro das células das leveduras variou de 1,67 a 10,00 μm e o diâmetro total das leveduras encapsuladas variou entre 4,17 e 34,16 μm. Os brotamentos foram melhor visualizados através do PAS e ocorreram em base estreita, de forma única ou múltipla, principalmente em polos opostos das células das leveduras ou formando uma cadeia. O terceiro artigo enfocou um estudo imuno-histoquímico (IHQ) em casos de aspergilose e zigomicose, visando a otimização do uso da técnica de IHQ na detecção de Aspergillus spp. e zigomicetos em tecidos de animais. Utilizaram-se dois anticorpos monoclonais fungo-específicos em fragmentos de tecidos (fixados em formol e embebidos em parafina) com diagnóstico histomorfológico prévio de aspergilose e zigomicose, os quais foram submetidos a três sistemas de detecção diferentes (dois biotinilados e um não biotinilado). Os dois anticorpos apresentaram alta especificidade e sensibilidade nos tecidos examinados. Não ocorreram reações cruzadas entre os anticorpos utilizados e os agentes etiológicos avaliados (incluindo casos de aspergilose, zigomicose, candidíase e pitiose). No entanto, reações inespecíficas foram observadas nas hifas em alguns casos, porém foram eliminadas através de um dos sistemas de detecção utilizados. A técnica de IHQ mostrou-se uma ferramenta muito útil na detecção e confirmação dos casos de aspergilose e zigomicose neste estudo retrospectivo.

Effects of various levels of L-ascorbic acid (L-AA) (12 and 25 mg) in ovo injected at 17 and 18 days of incubation, on embryonic and posthatch physiological variables in Ross 708 broilers were investigated. There were no significant treatment effects on the hatchability or serum concentrations of L-AA in the broilers. Eye L-AA concentrations were higher, and plasma nitric oxide levels were lower in male chicks treated in ovo with 12 mg of L-AA. While exposed to elevated atmospheric NH3 levels, the in ovo injection of 12 mg of L-AA increased the body weight gain and decreased the feed conversion ratio of the broilers from 0 to 28 days of age (doa). Decreased tracheal attenuation incidence was also experienced at 0 doa in the in ovo injected L-AA groups, and tracheal inflammation was significantly reduced at 28 doa in response to the in ovo injection of 12 mg of L-AA.

No description available.

Die equine Endometrose ist eine irreversible periglanduläre und/oder stromale Fibrose, betroffene Uterindrüsen zeigen meist glanduläre Alterationen und häufig eine zyklusasynchrone Differenzierung. Sie ist eine der wichtigsten Ursachen für Fruchtbarkeitsstörungen von Stuten und reduziert - abhängig von ihrer qualitativen und graduellen Ausprägung - die zu erwartende Abfohlrate. Fehldifferenzierte Endometrien treten nach neueren Erkenntnissen häufiger (16 % während der Decksaison) auf als bisher angenommen. Sie sind durch Abweichungen des endometrialen Funktions- und oder Aktivitätszustandes gekennzeichnet, wobei die irreguläre glanduläre Differenzierung (IGD) eine vollständige Pleomorphie ihrer Drüsenanschnitte zeigt. Die ungleichmäßige glanduläre Differenzierung (UGD) ähnelt mit ihren vom Grundzustand des Endometriums abweichend differenzierten Drüsennestern, die bisher als nicht-fibrotisch angesehen wurden, der equinen Endometrose. Bislang finden Fehldifferenzierungen (Ausnahme: die Atrophie in der Decksaison) keine Erwähnung im Kategorisierungsschema der Endometriumbioptate. Tatsächlich sind sie jedoch auch als fertilitätsmindernd anzusehen. Daher war das Ziel der vorliegenden Studie, mittels vergleichender lichtmikroskopischer und immunhistologischer Untersuchung der UGD und der Endometrose in Serienschnitten (n = 837) von Endometriumbioptaten (n = 33), neue Erkenntnisse darüber zu gewinnen, ob die UGD eine Frühform der Endometrose darstellt. Die Bioptate wurden 31 Stuten während der Decksaison (April bis September) der Jahre 1998 - 2012 entnommen und anhand ihrer Befunde in Gruppen eingeteilt: Stuten in Gr. 1 (n = 10) weisen eine UGD auf, Gr. 1a (n = 3) ist durch eine UGD und eine IGD, Gr. 2 (n = 10) durch eine UGD und eine Endometrose gekennzeichnet, während Gr. 2a (n = 10) eine UGD, eine Endometrose und eine IGD zeigt. Als Kontrollen dienten jeweils 5 Biopsien mit unveränderten Endometrien bzw. einer ggr. Endometrose. Die Serienschnitte wurden routinemäßig aufgearbeitet und mittels H.-E. gefärbt oder immunhistologischen Behandlungen zum Nachweis von α-Aktin, Desmin, Vimentin, Laminin, Östrogen- und Progesteronrezeptoren unterzogen. Die Ergebnisauswertung erfolgte semi-quantitativ und ohne die Erstellung einer Statistik. Alle ausgewählten UGD-Nester wurden in 3 Schnittebenen des Gewebes lichtmikroskopisch auf das Vorhandensein und die Ausprägung periglandulär angelagerter Stromazellen (PSC) überprüft. Dabei wiesen in Schnittebene 1 die Mehrzahl (78,15 %) der Drüsen innerhalb der UGD-Nester PSC auf, die häufig einschichtig (67,56 %), seltener (30,38 %) zwei- bis dreischichtig auftraten und die Drüsen meist (73,42 %) maximal zur Hälfte und selten (7,07 %) vollständig umschlossen. In tieferen Schnittebenen konnte eine dezente Zunahme der zwei- bis dreischichtigen PSC (35,85 % bzw. 34,67 %) festgestellt werden, welche die betroffenen Drüsen etwas häufiger vollständig umfassten (10,53 % bzw. 10,03 %). Immunhistologisch nimmt die α-Aktin-Expression innerhalb der UGD und (stärker ausgeprägt) in der Endometrose gegenüber unveränderten Stromazellen zu. Desmin wird im Vergleich mit unveränderten Arealen in der UGD und in der Endometrose von einem höheren Prozentsatz positiver Stromazellen exprimiert, jedoch – wie in der Literatur bereits für die UGD, nicht aber für die Endometrose, berichtet - mit verminderter Intensität. Die stromale Vimentin-Expression ist in UGD und Endometrose gegenüber den unveränderten Arealen insgesamt erhöht, wobei der Prozentsatz Vimentin exprimierender Stromazellen in der UGD etwas höher ausfällt als in der Endometrose. Auch die Drüsenepithelien zeigen in beiden Alterationen einen leicht erhöhten Prozentsatz und v.a. erhöhte Intensität von Vimentin. Für die Basallamina-Komponente Laminin kann v.a. ein verbreitertes/aufgefasertes, diskontinuierliches oder fehlendes, teilweise auch dünneres Erscheinungsbild um Drüsen in der UGD und in der Endometrose festgestellt werden. Die ER und PR werden von den Stromazellen in UGD und Endometrose insgesamt reduziert exprimiert, die Epithelzellen zeigen insbesondere für die ER eine leicht erhöhte Expression gegenüber unveränderten Drüsen. Zusammenfassend weist ein Großteil der UGD-Drüsen PSC auf. Dies lässt, in Verbindung mit dem vom unveränderten Endometrium abweichenden immunhistologischen Expressionsmuster der UGD sowie (meist stärker ausgeprägt) der Endometrose, den Schluss zu, dass die UGD eine Frühform der Endometrose darstellt. Daraus folgt die Notwendigkeit einer Überarbeitung und Ergänzung des histomorphologischen Kategorisierungsschemas für Endometriumbioptate, wobei für die UGD dieselbe (gradabhängige) prognostische Bewertung wie für die Endometrose angenommen werden muss. Künftige Studien können anhand von Verlaufsuntersuchungen überprüfen, ob UGD-Stuten in einem definierten Zeitraum eine den Kriterien des Kategorisierungsschemas entsprechende Endometrose entwickeln. / Equine endometrosis is known as periglandular and/or stromal fibrosis in combination with glandular alterations. In view of their function and/or activity, the affected glands often are deviating from the physiological stage of the cycle. It is one of the most important reasons for reduced fertility in mares and - in dependence on quality and degree - partly leads to a distinct reduction of the expected foaling rate. According to recent findings, endometrial maldifferentiations occur more often (16% during the breeding season) than expected. Affected endometria are characterised by glands deviating from the physiological stage of the cycle regarding their function and/or activity. The irregular glandular differentiation (IGD) shows a polymorphy of epithelial cells within one gland cross-section, while the unequal glandular differentiation (UGD) reminds on endometrosis because of the glandular nests, up to now seen as non-fibrotic, deviating from the stage of the cycle. Until now, endometrial maldifferentiations, excluding atrophia during the breeding season, are not mentioned in the catgorisation system for endometrial tissue examination. But in fact, they also are reducing the fertility. So the aim of this study was to get new insights if UGD is an early form of endometrosis by comparative histomorphological and immunohistochemical examinations on serial slides (n = 837) of 33 endometrial tissue specimens with UGD and endometrosis. The biopsies were taken of 31 mares during physiological breeding season (April to September) between 1998 and 2012 and grouped according to their diagnostic findings: The mares in group 1 (n = 10) show UGD, group 1a (n = 3) shows UGD and IGD while Group 2 (n = 10) is characterised by the presence of UGD and endometrosis and group 2a (n = 10) by UGD, endometrosis and IGD. Each 5 tissue samples without alterations, respectively a mild endometrosis served as controls. All serial slides (n = 837) were routinely processed and stained by hematoxylin and eosin or underwent an immunohistochemical treatment to detect α-actin, desmin, vimentin, laminin, estrogen- und progesteronreceptors. The evaluation of the results was carried out semi-quantitatively and without statistical analysis. Each three slide levels of the tissue samples were examined by light microscopy, if and of which gradual occurrence periglandular arranged stromal cells (PSC) were noticeable in deeper areas of the selected UGD-nests. In slide level 1 most of the glands (78.15%) within UGD show PSC, which mostly (73.42%) surrounds maximally half of the affected gland and rarely (7.07%) the whole gland, often (67.56%) consists of one layer and less frequently (30.38%) of two or three layers. A slight increase of PSC with two or three layers (35.85% respectively 34.67%) is detectable in deeper slide levels, also more often a complete surrounding of the glands (10.53% respectively 10.03%) by the PSC is seen. The immunohistochemical investigations reveal, compared to unchanged stromal cells, an increase of the stromal α-actin-expression in UGD and (stronger) in endometrosis. Desmin is expressed by a higher percentage of stromal cells in UGD as well as in endometrosis, but with reduced intensity. This is already described in literature for UGD but not for endometrosis. The stromal vimentin-expression is increased towards the unchanged areas in UGD and endometrosis, but the percentage of vimentin-positive stromal cells is slightly higher within UGD than within endometrosis. Vimentin also is detectable with slightly hightened percentage and first of all stronger intensity in epithelial cells of both alterations. Laminin, which is a part of the basal lamina, can be found around glands and around UGD- and fibrotic glands primarily is characterised by a widened/filamentous, discontinuous or missing, sometimes also slighter morphology. Compared to the unchanged areas, the stromal cells in UGD and endometrosis express the ER and PR in a reduced way, while epithelial cells show a slightly increased expression, especially for the ER. To sum up, a big part of the glands within UGD is characterised by PSC. In association with the immunohistochemical expression pattern of UGD and endometrosis differing (mostly stronger in endometrosis) from those of the unchanged endometrium, this is regarded as an aproach of UGD towards endometrosis, which suggests UGD being an early form of endometrosis. Because of that, a revision and completion of the histomorphological categorisation system for endometrial tissue samples is necessary, assuming the same prognostical evaluation für UGD as for endometrosis, that depends on the degree of the alterations. Future studies could verify, if mares suffering from UGD are developing an endometrosis according to the diagnostical criteria of the categorization system by a defined period of time.