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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.
51

Mixomas odontogenicos : analise clinicopatologica e imunohistoquimica de 67 casos / Odontogenic myxoma : clinicopathological and immunohistochemical analyse of 67 cases

Martinez Mata, Guillermo 25 August 2005 (has links)
Orientador: Oslei Paes de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-05T09:05:53Z (GMT). No. of bitstreams: 1 MartinezMata_Guillermo_M.pdf: 1070617 bytes, checksum: 13db66187a1a59eeaa5b18ca3a02cb9d (MD5) Previous issue date: 2005 / Resumo: O objetivo deste trabalho foi analisar as características clínicas, radiográficas, histopatológicas e perfil imunohistoquímico de 67 casos de mixomas odontogênicos (MOs), assim como relatar uma das casuísticas mais extensas da literatura mundial. Nesta pesquisa, o gênero feminino foi o mais afetado com 48 casos (71,64%) enquanto o gênero masculino foi em 19 (28,36%) (relação homem/mulher 1:2,5). A idade dos pacientes variou de 10 a 84 anos, média de 32,7. O sitio mais afetado foi a mandíbula em 27 casos (40.29%) Clinicamente, os MOs apresentaram-se como lesões assintomáticas em 29 (43,28%) casos, em 9 (13,43%) houve dor leve a moderada enquanto em outros 9 (13,43%) houve aumento de volume com evolução lenta. Radiograficamente dos 47 casos com dados disponíveis, 29 (43,28%) casos foram descritos como lesões radiolúcidas e 18 (26,86%) como mistas/multiloculares com aparência de favos de mel ou bolhas de sabão. Microscopicamente MOs apresentaram abundantes células fusiformes e estreladas homogêneas dispersas em um estroma mixóide e frouxo sem apresentar mitoses ou pleomorfismo celular. Em 6 casos (8,95%) evidenciaram presença de epitélio e 16 (23,88%) apresentaram calcificações do tipo distrófica. A reatividade de mastócitos foi positiva pela imunohistoquímica (clone AA1) em 27 casos (40,29%) e na coloração de azul de toluidina em 19 (28,35%). Treze dos 67 casos apresentaram epitélio imunoreativo para o coquetel de citoqueratinas AE1/AE3 e CK 14. Apenas 2 dos 13 casos foram positivos para CK 19 sugerindo uma possível origem odontogênica. As células fusiformes e estreladas foram reativas para vimentina em 67 casos, para a-actina músculo liso específica em 27 casos (40,29%) e para desmina em 6 (8,95%). Todos os casos foram negativos para a proteína S-100 e CK 8. O anticorpo CD-34 foi positivo em 20 (29,85%) casos, evidenciando múltiplas estruturas vasculares de diversos tamanhos. O marcador de proliferação celular Ki-67 foi positivo em apenas 2 casos apesar de sua alta taxa de recorrência. Baseado nestes achados, podemos sugerir que provavelmente os MOs sejam derivados de elementos mesenquimais, possivelmente de células fibroblásticas modificadas com características de miofibroblastos , e que outras nomenclaturas seriam mais adequadas para denominar esta lesão, tais como mixomas da região maxilar ou mixomas dos ossos gnáticos / Abstract: The aim of this study was to analyze the immunohistochemical profile and clinical, radiographical and histopathological characteristics of 67 cases of odontogenic myxoma (OM), as well as to report the greatest series related in the world literature. Females were more affected with 48 cases (71,64%) whereas males were in 19 (26.83%), male-female ratio 1:2.5. The patient¿s age ranged from 10 to 84 years (mean 32,7 years). The most frequent site affected was mandible with 27 cases (40,29%). Clinically, 29 cases (43,28%) of OM were asymptomatic, 9 cases (13,43%) presented pain and another 9 (13.43%) showed swelling. Radiographically, we disposed of clinical information in 47 cases, of which 29 (43,28%) cases were radioluced lesions and 18 (26,86%) were described as mixed/multilobular lesions of honey/comb or soap/bubble appearance. Microscopically, OM was constituted by a myxomatous background with spindle-shaped and stellate cells. Mitoses and pleomorphism were absent. Epithelium was present in 6 (8,95%) cases and 16 (23.88%) presented dystrophic calcifications. Immunohistochemical analyses revealed that 27 cases (40.29%) were positives for mast cell (clone AA1) and 19 (28,35%) positives for toluidine blue. Thirteen cases (19,47%) were positives for the antibody PAN CK AE1/AE3 and CK 14 respectively. Only 2 cases (2,98%) were positives for CK 19 suggering an possible odontogenic origin. The spindle-shaped and stellate cells showed positivity for vimentin in 67 cases, 27 cases (40,29%) for a-smooth muscle actin positives and 6 (8,95%) for desmin. All 67 cases were S-100 and CK 8 negatives. Twenty cases (29,85%) were immunopositives for CD-34, demonstring multiples blood vessels. Expression of the marker of cellular proliferation Ki-67 was low, being present only in two cases. Based on these findings, we can suggest that OM probably derives from mesenchymal elements, possibly modified fibroblasts with miofibroblastic diferentation, and that others nomenclatures as mixoma of the jaws could be suggest for this lesion / Mestrado / Patologia / Mestre em Estomatopatologia
52

Evaluating the specancer cell targeting peptides for applications in cancer diagnostics

Mazyambe, Margaret Kena January 2013 (has links)
>Magister Scientiae - MSc / Cancer is a disease most often associated with poor prognosis. During the development of the disease, cells acquire genetic mutations which result in changes in bio-molecules (DNA and protein), thus altering normal functioning of cells. These bio-molecules can thus serve as biomarkers for the diagnosis of cancer and can also facilitate the early detection of cancer. Antibodies labelled with organic fluorophores are typically used in immunohistochemistry techniques to screen cancerous tissue for the presence of biomarkers. More recently, researchers started to use cancer specific peptides (e.g LYP-1, RGD,) rather than antibodies for this purpose. Advantages of peptides include high affinity to their binding target, rapid accumulation at target sites and the ability to evade the immune system. Fluorescent nanocrystals or quantum dots are emerging as nanoparticles that can replace organic fluorophores. Several properties of quantum dots make these nanoparticles an ideal application in the detection of cancer related biomarkers. These include size tunable fluorescence emission, resistance to photobleaching as well as high quantum yields that result in bright emission of fluorescence. The aim of this research project was to investigate the specific binding of selected peptides to cancer cells using functionalized quantum dots. Since the cost of synthetic peptides are so high, the aim of this study was also to express these peptides in E.coli bacterial cells. Cancer targeting peptides were identified from literature and oligonucleotides with sequences encoding these peptides were designed. Four oligonucleotides encoding the peptides p6.1, p.L, MV and NL1.1 were successfully cloned using the pET21b plasmid vector. However, the peptides were not successfully expressed in E.coli. Cancer targeting peptides namely p.C, p.H, p.L, p6.1 and Frop-1 were chemically synthesized and obtained from GL biochem (Shanghai). These peptides were conjugated to quantum dots (Qdot 525) using 1-ethyl-3-(3-dimethylamino) carbodiimide HCl (EDC) chemistry. The peptidequantum dot conjugates were applied to cancer cells to achieve specific binding. The Kmst-6 noncancerous cell line served as a control. The binding of the peptide-quantum dot conjugates was analyzed using flow cytometry and fluorescence microscopy. The p.H peptide revealed the highest binding affinity to cancer cells as indicated by fluorescence intensity. This was followed by the p.C peptide which showed differential binding amongst the cancer cell lines. The Frop-1 peptide displayed the lowest binding affinity, while the binding affinity of the peptides to Kmst-6 cell lines was very low. This study demonstrated that the cancer targeting peptides used in this study bind to cancer cells and that the specificity with which these peptides bind to the cells depends on the cell types and the peptide
53

Diuretic factors controlling beetle Malpighian tubules : fluid secretion and immunohistochemistry

Holtzhausen, W.D. (Wendy Dianne) 18 July 2007 (has links)
Water balance in insects is under neuroendocrine control, and both diuretic and antidiuretic factors are thought to be involved. Despite being the largest and most diverse order of insects, the Coleoptera have been largely neglected in studies of hormonal control of excretion. However, the only insect from which both diuretic and antidiuretic peptides, acting on Malpighian tubules, have been isolated, is a beetle: the mealworm Tenebrio molitor. This study reports the effects of different diuretic factors on fluid secretion rates by mealworm tubules and briefly explores cross-reactivity of factors between beetle species, using the scarabaeid Onthophagus gazella. Attempts to localise an antidiuretic factor and a diuretic factor in the mealworm nervous system are also described. The study showed that calcitonin(CT)-like peptides from silkmoth and mosquito increased fluid secretion in mealworm tubules in a dose-dependent manner, but the cockroach CT-like peptide, Dippu-DH31, had no effect. The pharmacological agent thapsigargin, which mimics the action of kinins, caused a small but significant increase in tubule secretion rates. Since mealworm tubules are affected by more than one diuretic factor, the possibility of synergism between different factors was explored by testing CT-like peptides, thapsigargin and the mealworm corticotropin-releasing factor (CRF)-related diuretic peptide Tenmo-DH37, in various combinations and at different concentrations. No synergistic or additive effects were observed. C-terminal fragments of the locust and cockroach CRF-related diuretic peptides, Locmi-DH46 and Dippu-DH46 respectively, had no significant effect on fluid secretion. This is consistent with previous studies which have shown that the receptor binding and activation sites have to be linked in the same molecule for biological activity. However, the corresponding whole peptides increased fluid secretion, revealing the high degree of cross-reactivity of CRF-related peptides across insect orders. The mealworm diuretic factor Tenmo-DH37 increased fluid secretion in isolated tubules of O. gazelle in a dose-dependent manner, demonstrating cross-reactivity with this distantly related beetle species. However, brain homogenates from O. gazelle significantly inhibited fluid secretion in mealworm tubules. This is unusual, because extracts of insect nervous tissue have generally been shown to be a source of diuretic activity. Immunohistochemical techniques were used in an attempt to localise the mealworm antidiuretic factor Tenmo-ADFa in the nervous system of T. molitor. The antiserum developed against Tenmo-ADFa was found to be inadequately sensitive, and so these efforts were unsuccessful. The same techniques were employed in an attempt to locate the tissue containing a putative beetle CT-like peptide in the mealworm, using antiserum raised against the cockroach CT-like peptide Dippu-DH31. This too did not lead to a result. Experiments were repeated with various modifications, without success. It remains unclear whether the lack of results is due to degradation of the antiserum or if CT-like peptides are not present in detectable amounts in the mealworm nervous system. / Dissertation (MSc (Entomology))--University of Pretoria, 2007. / Zoology and Entomology / MSc / unrestricted
54

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
55

Immunohistochemical Detection of p53 Protein as a Prognostic Indicator in Prostate Cancer

Shurbaji, M. Salah, Kalbfleisch, John H., Thurmond, T. Scott 01 January 1995 (has links)
Mutation of the p53 gene is the most common genetic alteration in human cancers. The mutant p53 protein is more stable than the wild type and can be detected by immunohistology. The objective of the current study was to evaluate the immunohistological detection of p53 protein in prostate cancer and its utility as a prognostic indicator. We used a monoclonal anti-p53 antibody and immunostained primary prostate adenocarcinomas (stages Al to Dl) from 109 patients with a mean follow-up of 3.8 years (range, 1.3 to 9.3 years). Immunoreactivity for p53 was seen in 23 cancers (21%). There were 12 instances of progression (14%) among the p53-negative cancers versus seven (30%) among the p53-positive group. Survival analysis using three univariate statistical tests showed that p53 reactivity (P < .03), Gleason score (P < .01), and stage (P < .05) had significant effects on time to progression of prostate cancer. Multivariate analyses showed that Gleason score was significant with all three tests; p53 reactivity was significant with the Wilcoxon test but only approached significance by the log rank and Cox tests. When the analyses included only patients with Gleason scores 2 to 7 (N = 94), univariate analyses showed that p53 reactivity was strongly related to progression of prostate cancer (P < .007). Stage also was significant (P < 0.04), but Gleason score was not. Multivariate analyses showed only p53 reactivity to be significant (P < .007). In conclusion, mutation of the p53 gene may be involved in prostate cancer carcinogenesis. p53 reactivity marks an aggressive subset of prostate cancer and appears to be an independent prognostic indicator that is particularly valuable among the low to intermediate grade cancers.
56

LOXL4 Is a Selectively Expressed Candidate Diagnostic Antigen in Head and Neck Cancer

Weise, Jan, Rudolph, Pierre, Heiser, Axel, Kruse, Marie Luise, Hedderich, Jürgen, Cordes, Christian, Hoffmann, Markus, Brant, Ommo, Ambrosch, Petra, Csiszar, Katalin, Görögh, Tibor 01 June 2008 (has links)
Selective up-regulation of the mRNA of LOXL4, a member of the LOX matrix amine oxidase family, significantly correlated with lymph node metastases and higher tumour stages in head and neck squamous cell carcinomas (HNSCC). To evaluate the diagnostic and prognostic value of the protein we produced an antibody specific for LOXL4 and assessed the expression in 317 human HNSCC specimens. The LOXL4 protein was detected in 92.7% of primary tumours, in 97.8% of lymph node metastases and in affected oral mucosa with high-grade dysplasia, but was absent in various non-neoplastic tissues of the head and neck. TNM categories and overall survival did not link to grades of immunoreactivity. Studies in cultured primary hypopharyngeal HTB-43 carcinoma cells detected perinuclear and cell surface expression of LOXL4, but no nuclear localisation. Therefore, its interactive SRCR-domains and catalytic activity combined with tumour cell specific expression and cell surface associated location indicate multiple functions in tumour cell adhesion and interactions with the extracellular matrix. Our data suggest that LOXL4 is useful both as tumour marker and target in the treatment of HNSCC.
57

Tangential distribution of SMI-32 immunoreactive neurons in cat visual cortex

Mareschal, Isabelle January 1994 (has links)
No description available.
58

Immunohistochemistry of the Gills of the Channel Catfish Ictalurus Punctatus: Cells and Neurochemicals That May Be Involved in the Control of Cardioventilatory Reflexes

Oden, David S. 12 1900 (has links)
In teleost fishes the neurochemicals involved in sensing and responding to hypoxia are unresolved. Serotonergic branchial neuroepithelial cells (NECs) are putative O2 chemoreceptors believed to be homologous to the neural crest (NC) derived APUD (amine-precursor uptake and decarboxylation) pulmonary NECs and carotid body type-1 glomus cells. Branchial NECs contain serotonin (5-HT), thought to be central to the induction of the hypoxic cardioventilatory reflexes. However, application of 5-HT in vivo does not elicit cardioventilatory reflexes similar to those elicited by hypoxia. But previous in vitro neural recordings from glossopharyngeal (IX) afferents innervating O2 chemoreceptors in the trout gill show the same discharge response to hypoxic conditions as does that of acetylcholine (ACh) application. This evidence strongly supports the cholinergic hypothesis of chemoreceptor impulse origin rather than a serotonergic-induced impulse origin model. We therefore hypothesized that NECs contain ACh among other neurochemicals in cells belonging to the APUD series. Although serotonergic branchial NECs did not colocalize with ACh using immunohistochemical methods, several populations of ACh and/or tyrosine hydroxylase (TH) (catecholaminergic) positive, dopamine (DA) negative, cells were found throughout the second gill arch of the channel catfish Ictalurus punctatus. In addition, the NC derivation marker zn-12 labelled the HNK-1-like epitope (Human natural killer) expressed by lamellar pillar cells’ collagen column-associated pillar cell adhesion molecules (CC-PCAMs), evidence confirming their hypothesized NC origin.
59

Cellular localization of the blood-brain barrier in the brainstem: Area postrema and nucleus tractus solitarius

Willumsen Fransson, Sara January 2008 (has links)
<p>The blood-brain barrier regulates the transport into the brain and protects the central nerve system (CNS) from toxics substances. However some areas of the brain, called circumventricular organs (CVO), lack the blood-brain barrier. One of these is area postrema (AP), which is located in the brainstem immediately adjacent to the nucleus tractus solitarius (NTS). These two areas together regulate autonomic behaviours such as food intake, and also make up the vomiting center.</p><p>The hormones leptin and ghrelin, which regulate food intake, are too big to pass the blood-brain barrier, but have receptors in NTS.</p><p>In this study we used immunohistochemistry to obtain a detailed map of the different components of the blood-brain barrier in AP and NTS.</p><p>The results suggest that there is a barrier that prevents diffusion of substances from AP into NTS. However, there seems to be some vessels in NTS that have a weaker or no barrier characteristics. These vessels could provide an entrance for peripheral substances to neurons in NTS.</p>
60

A study of the immunopathogenesis of inflammatory bowel disease in cats

Waly, Nashwa Esmat Abdel-Azim January 2001 (has links)
No description available.

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