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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modulation of microtubule properties by members of the WNT pathway : implications for Alzheimer's disease

Dayanandan, Rejith January 1999 (has links)
No description available.
2

Growth control mechanisms, luminal factors, and cancer : a molecular approach

Chinery, Rebecca January 1994 (has links)
No description available.
3

Studies on the pathogenesis and prevention of equine laminitis

Andrew William Van Eps Unknown Date (has links)
No description available.
4

Ρυθμιστικοί παράγοντες μετάβασης από την φάση G1 στην φάση S του κυτταρικού κύκλου σε κακοήθεις όγκους του ελύτρου των περιφερειακών νεύρων και νευροϊνώματα

Κουρέα, Ελένη 09 April 2010 (has links)
- / -
5

Análise comparativa das características histológicas e imunoistoquímicas do pilomatricoma, craniofaringioma e tumor odontogênico cístico calcificante / Comparative analysis of histological and immunohistochemical features of pilomatricoma, craniopharyngioma and calcifying cystic odontogenic tumor

Rumayor Piña, Alicia, 1984- 22 August 2018 (has links)
Orientador: Oslei Paes de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T06:50:59Z (GMT). No. of bitstreams: 1 RumayorPina_Alicia_M.pdf: 5492242 bytes, checksum: d72d6dba44229ac2e8e3d662cfee7879 (MD5) Previous issue date: 2013 / Resumo: Pilomatricoma (PM), craniofaringioma (CF) e tumor odontogênico cístico calcificante (TOCC) são tumores que compartilham uma característica histopatológica marcante, a presença de células fantasmas. O objetivo deste trabalho foi analisar e comparar as características histológicas e imunoistoquímicas destas neoplasias. Foram usados 43 casos, sendo 21 PMs, 14 CFs e 8 TOCCs. A metodologia incluiu avaliação de todos os casos em cortes corados em hematoxilina e eosina, e reações imunoistoquímicas para anticorpos contra CKs AE1/AE3, 8, 14 e 19, CD138, ?-Catenina, Glut-1, D2-40, FAS e CD10. Os PMs acometeram principalmente a pele da região facial de homens com média de idade de 17 anos. Os CFs envolveram a região supraselar de pacientes na primeira e segunda década de vida. Os TOCCs predominaram na mandíbula de mulheres com média de idade de 47 anos. Microscopicamente, células basalóides, transicionais e fantasmas foram os principais tipos celulares observados nos PMs. Os CFs e TOCCs apresentaram epitélio formado por camada basal de células colunares em paliçada, região suprabasal composta por células escamosas triangulares, com aspecto semelhante ao retículo estrelado, além de regiões de células transicionais, fantasmas e agregados de células epiteliais em padrão de redemoinho. Nos PMs, as células basalóides mostraram positividade para CD138, ?-Catenina e CD10, enquanto que as células transicionais expressaram principalmente FAS. Todos os casos de CF e TOCC mostraram positividade para CK AE1/AE3 em todas as camadas do epitélio. Nos CFs, CK14 foi expressa na camada basal, e CK8 na região semelhante ao retículo estrelado. Além disto, as células transicionais mostraram expressão forte para Glut-1 e os agregados celulares em forma de redemoinho para CD10. Com relação ao TOCC, a camada basal e a região semelhante ao retículo estrelado mostraram positividade para CK14 e ?-Catenina, enquanto que as células transicionais expressaram CK19, FAS e CD10. As estruturas em padrão de redemoinho foram intensamente positivas para CKs 8, 19 e CD10. Observou-se expressão nuclear de ?-Catenina nos casos de CF e TOCC nas células transicionais e nos agregados em redemoinho. As células fantasmas mostraram expressão fraca apenas para AE1/AE3 e FAS. Em resumo, a semelhança histológica principal entre os três tumores, é a presença de células fantasmas. Apesar de apresentarem aspectos histológicos similares, as três lesões estudadas apresentam histogênese diferente. O mecanismo de formação das células fantasmas a partir das células epiteliais é difícil de ser determinado visto que há perda de expressão de praticamente todos os marcadores usados neste estudo / Abstract: Pilomatricoma (PM), craniopharyngioma (CP) and calcifying cystic odontogenic tumor (CCOT) are entities that share a striking histopathological feature, the ghost cells. The aim of this study was to analyze and compare the histological and immunohistochemical features of these neoplasms. A total of 43 cases were studied, including 21 PM, 14 CP and 8 CCOT. Methods included review of all cases in hematoxylin and eosin stained sections, and immunohistochemical reactions for antibodies against CKs AE1/AE3, 8, 14 and 19, CD138, ?-Catenin, Glut-1, D2-40, FAS and CD10. PM mainly affected facial skin of men with a median age of 17 years-old; presenting as an asymptomatic nodule. CP involved the suprasellar region of patients in the first and second decades of life, while CCOT predominated in the mandible of women with a median age of 47 years-old. Microscopically, basaloid, transitional and ghost cells were the main cell types identified in PM. CP and CCOT characteristically showed an epithelium with a basal layer of palisading columnar cells, a suprabasal layer composed of squamous cells that assumed a triangular shape, and acquire a stellate reticulum appearance due to increased intercellular space by accumulation of amorphous substances, besides areas of transitional, ghost cells and clusters of epithelial cells in a whorl-like array are present. Basaloid cells of PM showed positivity for CD138, ?-Catenin and CD10, whereas transitional cells expressed mainly FAS. All cases of CP and CCOT showed positivity for AE1/AE3 in all epithelial layers. CP showed expression of CK14 in the basal layer, whereas CK8 was positive in the suprabasal region similar to stellate reticulum. Moreover, transitional cells showed strong positivity for Glut-1, and whorl-like clusters for CD10. Regarding to CCOT, the basal layer and the region similar to stellate reticulum showed positivity for CK14 and ?-Catenin, whereas transitional cells expressed CK19, FAS and CD10. Whorl-like clusters were strongly positive for CKs 8, 19 and CD10. Nuclear ?-Catenin expression was observed in the transitional cells and whorl-like clusters of CCOT and CP. Ghost cells showed weak expression of AE1/AE3 and FAS. The main similarity between these tumors is the presence of ghost cells. Despite showing similar histology, these three tumors have different histogenesis. It was not possible to determine the process of ghost cell formation, so there was no clear sequence of proteins expression from basal cells up to ghost cells, which were negative for most of the markers used / Mestrado / Patologia / Mestra em Estomatopatologia
6

Evaluation of a Paratuberculosis Quantitative Polymerase Chain Reaction Assay with Microscopic Correlation

Tyler, Ronald Dale Jr. 29 May 2012 (has links)
Paratuberculosis is an intestinal condition in ruminants infected with Mycobacterium avium subspecies paratuberculosis (MAP) and precedes Johne's disease, a chronic enteric disorder in ruminants caused by MAP infection. Necropsy with histopathology provides definitive diagnosis of Johne's disease and positive culture of MAP from tissues provides definitive diagnosis of paratuberculosis. To determine assay sensitivity, 85 formalin-fixed paraffin-embedded (FFPE) tissues from ruminants diagnosed with Johne's disease were tested with a commercial paratuberculosis quantitative polymerase chain reaction (qPCR) assay and had a sensitivity of 92%. To determine assay specificity, 21 FFPE tissues from animals without gastrointestinal disease combined with 13 FFPE tissues from non-ruminant animals (frog, dove, turtle, dog, and 2 cats) with non-paratuberculosis mycobacterial diseases were tested with the commercial qPCR assay and had a specificity of 100%. Slides prepared from the FFPE tissue blocks were stained with hematoxylin & eosin (H&E) and Ziehl-Neelsen's (acid fast stain), then examined for granulomatous inflammation and scored on a scale from 0-4 based on the quantity of acid fast bacteria (AFB). Digital microscopy and morphometric software were used to compute an acid fast bacteria area index (AFBAI) to evaluate a more precise correlation with the qPCR results. The quantity of AFB in tissue slides showed medium to strong correlation with the appropriate qPCR results. The results indicate that the commercial qPCR assay can be used on FFPE tissues with good results and the qPCR results have medium-strong correlation with quantitative acid fast histopathology. / Master of Science
7

Histopathological effects of metal and metalic nanoparticles on the body systems of rainbow trout (Oncorhynchus mykiss)

Al-Bairuty, Genan Adnan January 2013 (has links)
Histopathology studies of metal nanoparticles (NPs) compared to traditional forms of metal in fish are scarce. Additionally, it is unclear whether metal nanoparticles cause greater or different pathologies compared to other forms of metal. The current study aimed to assess the pathological effects of Cu-NPs and TiO2 NPs on rainbow trout via various routes of exposure and, where appropriate, to compare them to either the equivalent dissolved metal salts or bulk powder forms. The first experiment showed that waterborne exposure to Cu-NPs and CuSO4 caused similar types of organ pathologies and alteration in the spleen content, however there were some material-type effects in the incidence injuries; with Cu-NPs in some organs by causing more injury in the intestine, liver, and brain when compared to effects caused by the equivalent concentration of CuSO4. Lowering water pH did have an effect on the toxicity of Cu-NPs and dissolved Cu in trout, and the results illustrated that both Cu treatments are more toxic at pH 5 than pH 7 by causing more physiological and pathological changes, although both CuSO4 and Cu-NP treatments showed similar types of organ lesions. Waterborne exposure to TiO2 NPs and bulk forms of TiO2 showed similar types of organ pathologies and alteration in the spleen contents, but there was a material-type effect in some organs (more injury with the bulk treatment than the NP form). After 96 h following intravenous injections of bulk or TiO2 NPs in trout, organs showed similar types of pathologies; except the spleen and kidney which showed a material-type effects (more injury with NPs than the bulk forms). This could be attributed to the highest Ti accumulation from the TiO2 NP treatment in the kidney and spleens, or to the role of these organs in filtrating the circulating blood. Overall, this thesis demonstrates that metal-NPs produced similar types of organ pathologies to traditional forms of metals through different routes of exposure, but there were some material-type effects on the incidence of injuries in some organs. The results have also added some understanding on the fate, and effects of NPs by identifying the target organs involved. Some of the nano-specific effects may need to be given extra consideration in environmental and human health risk assessments.
8

Quantitative histopathology identifies patients with thin melanomas who are at risk for metastases.

Glazer, Evan S, Bartels, Peter H, Lian, Fangru, Kha, Stephanie T, Morgan, Sherif S, da Silva, Vinicius D, Yozwiak, Michael L, Bartels, Hubert G, Cranmer, Lee D, de Oliveira, Jefferson K, Alberts, David S, Warneke, James A, Krouse, Robert S 06 1900 (has links)
This small exploratory study was designed to test the hypothesis that thin melanoma lesions contain nuclei of two similar phenotypes, in different proportions. In lesions likely to progress to metastatic disease, one of these phenotypes predominates. Histopathological sections from 18 cases of thin melanomas which did not progress to metastasis, and from 10 cases which did progress were imaged and digitized at high resolution, with a total of 2084 and 1148 nuclei, respectively, recorded. Five karyometric features were used to discriminate between nuclei from indolent and from potentially metastatic lesions. For each case, the percentage of nuclei classified by the discriminant function as having come from a potentially metastatic lesion was determined and termed as case classification criterion. Standard histopathological criteria, such as ulceration and high mitotic index, indicated in this material the need for intensive therapy for only one of the 10 participants, as compared with 7/10 identified correctly by the karyometric measure. Using a case classification criterion threshold of 40%, the overall accuracy was 86% in the test set. The proportion of nuclei of an aggressive phenotype may lend itself as an effective prognostic clue for thin melanoma lesions. The algorithm developed in this training set appears to identify those patients at high risk for metastatic disease, and demonstrates a basis for a further study to assess the utility of prognostic clues for thin melanomas.
9

Pólipos colorectales: actualización en el diagnóstico

Arévalo, F., Aragón, V., Alva, J., Perez Narrea, M., Cerrillo, G., Montes, P., Monge, Eduardo 11 August 2014 (has links)
El diagnóstico histológico de los pólipos colorrectales determina la conducta que tomará el médico especialista con el paciente. Con la aparición de nuevos pólipos en los últimos años, la clasificación histológica se ha tornado más compleja y amplia. Nuestro objetivo es actualizar los conceptos en el diagnóstico histológico de pólipos de colon de una manera clara y de fácil comprensión, especialmente para gastroenterólogos y patólogos.
10

Parasites of native and exotic freshwater fishes in the south-west of Western Australia

marina@umt.edu.my, Marina Hassan January 2008 (has links)
Fewer than 200 fish species are found in freshwater habitats in Australia, of which 144 are confined exclusively to freshwater. At least 22 species of exotic freshwater fish have been introduced into Australia, and 19 of these have established self-sustaining populations. However, the parasite fauna of both native and exotic freshwater fishes in Australia is poorly known. This is particularly the case in the south-west of Western Australia, where there have been no previous comprehensive studies of the parasites of 14 native species and nine or more exotic species of fish found in freshwater habitats. This study represents a survey of the parasites of freshwater fishes in the South West Coast Drainage Division and reports 44 putative species of parasites in 1429 individual fishes of 18 different species (12 native and six exotic) from 29 locations. Parasites were found in 327 (22.88%) fishes, and of the infected fishes, 200 (61.16%) were infected with only one species of parasite and 127 (38.84%) were infected with two or more species of parasites. For helminth and arthropod parasites, which were more comprehensively surveyed than protozoan and myxozoans, I found 37 species compared to 77 species found in a recent study of fishes from the East Coast Drainage Division. The present study demonstrated that parasitic infection was significantly more common in native fish species (mean prevalence of infection with any species of parasite = 0.36 ± 0.09) than in exotic fish species (0.01 ± 0.12). Parasites were found in all native fish species, but in only two exotic fish species that were examined. Parasite regional and component community diversity were estimated by species richness (the number of species, S) and by an index of taxonomic diversity (HT). Both parasite species richness and parasite taxonomic diversity were significantly greater in native fish species (mean S = 10.5 ± 2.3; mean HT = 1.19 ± 0.14) than in exotic fish species (mean S = 1.6 ± 3.3; mean HT = 0.27 ± 0.20). These relationships were consistent over all geographic locations that were sampled. The reduced parasite load of exotic species compared to native species has been previous reported across a wide range of taxa. It is thought to arise partly because founding populations of hosts have a low probability of harbouring the species’ total parasite fauna, and partly because parasites that infect introduced exotic species may not be able to maintain their life cycle in the new environment. It has been suggested that a reduced parasite load increases the competitive ability of exotic species compared to native species (the parasite release hypothesis) and this may partly explain the abundance and apparent competitive success of exotic over native species of freshwater fish in the South West Coast Drainage Division. For native species of fish, there were major differences among species in both prevalence of parasitic infection and parasite community diversity, but this variation was not related to fish size, whether the fish were primarily freshwater or primarily estuarine, or whether they were primarily demersal or pelagic. In this study, I report two new parasites in south western Australian waters. Both are copepod parasites; Lernaea cyprinacea and a new species of Dermoergasilus. The Dermoergasilus appears to be native to the south-west of Western Australia and has been described as Dermoergasilus westernensis. It differs from previously described species in the genus principally by the armature of the legs. This new species was found on the gills of freshwater cobbler, Tandanus bostocki and western minnow, Galaxias occidentalis in two different river systems. Lernaea cyprinacea is an introduced parasitic copepod found on the skin and gills of freshwater fishes in many areas of the world. The parasite has not previously been reported in Western Australia. We found infestations of L. cyprinacea on four native fish species (G. occidentalis; Edelia vittata; Bostockia porosa; T. bostocki) and three introduced fish species (Carassius auratus; Gambusia holbrooki; Phalloceros caudimaculatus) at two localities in the Canning River, in the south-west of Western Australia. The parasite has the potential to have serious pathogenic effects on native fish species, although it appears to be currently localised to a small section of the Canning River. Over all localities from which fishes were sampled in the present study, the proportion of native freshwater fishes with parasitic infections and the component community diversity of the parasite fauna of native fishes were both negatively related to habitat disturbance, in particular to a suite of factors (river regulation, loss of riparian vegetation, eutrophication and presence of exotic fish species) that indicate increased human usage of the river and surrounding environment. The reduced parasite load and diversity in native fishes from south-west rivers with greater human usage was due principally to the loss of a number of species of trematode, cestode and nematode endoparasites which use fishes as intermediate hosts. Other studies have also found that endoparasites with complex life cycles are most likely to be adversely affected by environmental changes, presumably because any environmental changes which impact on either free-living parasite stages or on any of the hosts in the complex train of parasite transmission will reduce parasite population size and may cause local extinction of the parasite species. The most heavily infected species of native freshwater fish in the South West Coast Drainage Division was T. bostocki with 96% of all individuals containing at least one species of parasite. As with most freshwater fishes of south-west Australia, T. bostocki is limited in its distribution to waterways with relatively low salinity. The degree of parasitism and histopathology of internal and external organs in T. bostocki from the Blackwood River was examined over a period of rapid, seasonal changes in water salinity. As salinity increased, the infracommunity richness and prevalence of ectoparasites on the skin of fishes decreased, while the infracommunity richness and prevalence of endoparasites increased. This was associated with a decrease in histopathological lesion scores in the skin and an increase in histopathological lesion scores in internal organs, particularly the intestine. I hypothesise that the seasonal spike in salinity had two contrasting effects on parasitic infections of T. bostocki. Firstly, it increased the mortality rate of parasites directly exposed to water, leading to a decrease in ectoparasitic infection and associated pathology. Secondly, it suppressed immune function in fish, leading to a decreased mortality rate of parasites not directly exposed to water and a more severe pathological response to endoparasitism.

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