Spelling suggestions: "subject:"tumor hypoxia"" "subject:"humor hypoxia""
11 |
Imunoexpress?o de VEGF-C, VEGFR-3 e HIF-1? e mensura??o da densidade linf?tica em carcinomas epiderm?ides de l?bio inferior metast?ticos e n?o-metast?ticos: uma rela??o com par?metros clinicopatol?gicos e progn?sticosMartins, Ana Rafaela Luz de Aquino 19 July 2012 (has links)
Made available in DSpace on 2014-12-17T15:32:31Z (GMT). No. of bitstreams: 1
AnaRLAM_TESE.pdf: 3774507 bytes, checksum: 2b9028dcadafe1a4c66e01ba9daab791 (MD5)
Previous issue date: 2012-07-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Squamous cell carcinoma of the lower lip is among the most common malignant tumors of the
oral and maxillofacial region, with good prognosis in more than 90% of patients with 5-year
survival. In these carcinomas, the development of lymph node metastasis decreases the
prognosis and it has been associated with the formation of new lymphatic vessels. It has been
suggested the important role of vascular endothelial growth factor-C (VEGF-C), the receptor
type 3 VEGF (VEGFR-3) and hypoxia-induced factor 1 (HIF-1) in this process. The aim of
this study was to evaluate the immunoexpression of VEGF-C, VEGFR-3 and HIF-1? and
correlate with intra and peritumoral lymphatic density in squamous cell carcinomas of the
lower lip metastatic and non-metastatic. The sample consisted of 50 cases of squamous cell
carcinoma of lower lip, of which 25 had regional lymph node metastasis and 25, absence of
metastasis. The percentages of cells immunostained for VEGF-C, VEGFR-3 and HIF-1? in
front of tumor invasion and in the center of tumor were evaluated. Microvessel density
lymphatic (MDL) was determined by the counting of lymph microvessels immunostained by
the anti-D2-40 in five fields (200?), in an area of evaluation with 0.7386 mm2. The invasion
of the lymph vessels by malignant cells was also evaluated. Immunostaining was correlated
with the presence and absence of metastasis, TNM clinical stage, local recurrence, disease
outcome (remission of injury or patient death) and histological grading. The analysis of intra
and peritumoral lymphatic density showed no significant association with clinicopathological
parameters and immunoexpressions of VEGF-C, VEGFR-3 and HIF-1? (p > 0,05). There was
a weak positive correlation, significant, between intra and peritumoral lymphatic density (r =
0,405; p = 0,004). VEGF-C showed no significant association with clinicopathological and
prognosis parameters (p > 0,05). For VEGFR-3, there was scarce membrane staining and
intense and homogenous cytoplasmic staining in neoplastic cells. Percentage of positive
cytoplasmic VEGFR-3 in center of tumor, exhibited a statistically significant association with
metastasis (p = 0,009), patient death (p = 0,008) and histological grades of malignancy
proposed by Bryne et al. (1992) (p = 0,002) and World Health Organization (p = 0,003). A
low positive correlation was statistically significant between the immunoreactivity of VEGFC
and VEGFR-3 cytoplasmic (r = 0,358; p = 0,011) and between the percentage of positive
cytoplasmic VEGFR-3 in front of tumor invasion and in the center of the tumor (r = 0,387; p
= 0,005) was also demonstrated. There was no association between HIF-1?,
clinicopathological and prognosis parameters, and VEGF-C and VEGFR-3. The percentage of
nuclear positivity for HIF-1? was significantly higher in cases without invasion of peritumoral
lymphatic (p = 0,040). Based on the results we can conclude that most cytoplasmic expression
of VEGFR-3 in center of tumor in metastatic cases, high degree of malignancy and poorly
differentiated, contributes to poor outcome of squamous cell carcinoma of the lower lip,
including patient death. Intra and peritumoral lymphatic density seems to be not associated
with lymph node metastasis in these carcinomas / O carcinoma epiderm?ide de l?bio inferior est? entre as les?es malignas mais comuns da
regi?o oral e maxilofacial, com progn?stico bom, em mais de 90% dos pacientes com
sobrevida de 5 anos. Nestas les?es, o desenvolvimento de met?stase linfonodal diminui
sobremaneira o progn?stico e tem sido associado ? forma??o de novos vasos linf?ticos. Tem
sido sugerido o importante papel do fator de crescimento endotelial vascular-C (VEGF-C), do
receptor tipo 3 do VEGF (VEGFR-3) e do fator 1 induzido por hip?xia (HIF-1) neste
processo. O objetivo desta pesquisa foi avaliar as imunoexpress?es de VEGF-C, VEGFR-3,
HIF-1? e a densidade linf?tica intra e peritumoral em carcinomas epiderm?ides de l?bio
inferior metast?ticos e n?o-metast?ticos, correlacionando-as com par?metros
clinicopatol?gicos e progn?sticos. A amostra foi constitu?da por 50 casos de carcinoma
epiderm?ide de l?bio inferior, 25 com met?stase linfonodal regional e 25 sem met?stase.
Foram avaliados os percentuais de c?lulas imunomarcadas para os anticorpos anti-VEGF-C,
anti-VEGFR-3 e anti-HIF-1?, no front de invas?o e no centro tumoral. A densidade
microvascular linf?tica (LMVD) foi estabelecida por meio da soma da contagem de
microvasos linf?ticos imunomarcados pelo anticorpo anti-D2-40, em cinco campos (200?),
em uma ?rea de avalia??o com 0,7386 mm2. A invas?o dos vasos linf?ticos por c?lulas
neopl?sicas tamb?m foi avaliada. A imunomarca??o foi relacionada com a presen?a e
aus?ncia de met?stase, estadiamento cl?nico TNM, recidiva local, desfecho da doen?a
(remiss?o da les?o ou ?bito dos pacientes) e grada??o histol?gica. A an?lise das densidades
linf?ticas intra e peritumorais n?o demonstrou associa??o significativa com os par?metros
clinicopatol?gicos, progn?sticos e imunoexpress?es de VEGF-C, VEGFR-3 e HIF-1? (p >
0,05). Houve fraca correla??o positiva, significativa, entre as densidades linf?ticas intra e
peritumorais (r = 0,405; p = 0,004). O VEGF-C n?o exibiu associa??o significativa entre os
par?metros clinicopatol?gicos e progn?sticos avaliados (p > 0,05). Para o VEGFR-3, houve
escassa marca??o membranar e intensa e homog?nea marca??o citoplasm?tica nas c?lulas
neopl?sicas. O percentual de positividade citoplasm?tica do VEGFR-3, no centro tumoral,
exibiu associa??o estatisticamente significativa com a presen?a de met?stase (p = 0,009),
?bito dos pacientes (p = 0,008) e grada??es histol?gicas de malignidade proposta por Bryne et
al. (1992) (p = 0,002) e pela Organiza??o Mundial de Sa?de (p = 0,003). Uma fraca
correla??o, estatisticamente significativa, entre a imunoexpress?o de VEGF-C e VEGFR-3
citoplasm?tica (r = 0,358; p = 0,011) e entre os percentuais de positividade citoplasm?tica de
VEGFR-3 no front de invas?o e no centro tumoral (r = 0,387; p = 0,005) tamb?m foi
demonstrada. N?o foi observada associa??o entre o HIF-1? os par?metros clinicopatol?gicos,
progn?sticos e o VEGF-C e VEGFR-3. O percentual de positividade nuclear para HIF-1? foi
significativamente maior nos casos sem invas?o dos linf?ticos peritumorais (p = 0,040). Com
base nos resultados pode-se concluir que a maior express?o citoplasm?tica de VEGFR-3, no
centro tumoral, nos casos metast?ticos, de alto grau de malignidade e pobremente
diferenciados, contribui para pior evolu??o dos carcinomas epiderm?ides de l?bio inferior,
incluindo o ?bito dos pacientes. As densidades linf?ticas intra e peritumorais parecem n?o
estar associadas ao densenvolvimento de met?stase linfonodal nestes carcinomas
|
12 |
Die Charakterisierung der induzierbaren Stickstoffmonoxidsynthase im murinen RENCA-Nierenzellkarzinommodell unter spezieller Berücksichtigung tumorassoziierter Makrophagen, der Gefäßdichte und Tumorhypoxie / Characterization of inducible nitric oxide synthase in murine renal cell carcinoma considering of tumor associated macrophages, vessel distance and tumor hypoxiaKrösel, Juliane Franziska 11 March 2013 (has links)
Einleitung: Ziel dieser Arbeit war es, das RENCA-Nierenzell-Karzinommodell anhand der Hypoxie-induzierten Nekrosen, der Makrophageninfitration sowie der iNOS-Expression und –aktivität zu charakterisieren.
Methoden: Für die Erzeugung lokaler Tumoren, wurden Balb/c-Mäusen in vitro kultivierte RENCA-Zellen subkutan appliziert. Die Quantifizierung des Makrophageninfiltrates sowie die Charakterisierung der Hypoxie im Tumorgewebe erfolgten mittels immunhistochemischer Färbungen. Für die Darstellung der Stickstoffmonoxid-Aktivität kamen neben der Immunhistochemie die Reverse Transkriptase Polymerase-Kettenreaktion (RT-PCR) zur Anwendung. Der Nitrit-Gehalt der Tumorproben wurde mittels Griess-Reaktion bestimmt.
Ergebnisse: Spontan hypoxische Tumornekrosen sind assoziiert mit einer signifikant geringeren Gefäßdichte. Das Ausmaß der Nekrosen korreliert mit dem Alter der Tumoren. Alte Tumoren (28 Tage) zeigen eine höhere Makrophageninfiltration als junge Tumoren (12 bis 19 Tage). Obwohl die iNOS-Expression auf Proteinebene keinen signifikanten Unterschied zwischen alten und jungen Tumoren ergab, findet sich auf mRNA-Ebene eine signifikant erhöhte iNOS-Expression in alten Tumoren. Hinsichtlich der αActinin-4-Expression konnte kein signifikanter Unterschied gesehen werden.
Schlussfolgerung: Bei annähernd gleicher iNOS- und αActinin-4-Expression beziehungsweise erhöhter iNOS-mRNA-Expression ist die Konzentration an Nitrit in Tumoren mit hypoxischer Nekrose reduziert. Daraus kann man schließen, dass die Aktivität der NO-Synthase unter hypoxischen Bedingungen reduziert ist. Dies stützt wiederum die Vermutung, einer die iNOS-Aktivität steuernden normoxie-abhängigen Assoziation von αActinin-4 und iNOS. Die Aktivitätsinhibierung der iNOS könnte somit ein Mechanismus sein, durch den Hypoxie die Zytotoxizität von TAM inhibiert. Die abnehmende Gefäßdichte mit zunehmendem Tumoralter könnte möglicherweise auf eine Regression der Tumorgefäße zurückzuführen sein. Denkbar wäre, dass die Gefäßregression durch makrophagenabhängige Zytokine begünstigt wird.
|
13 |
Monte Carlo Simulation to Study Propagation of Light through Biological TissuesPrabhu Verleker, Akshay 20 September 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Photoacoustic Imaging is a non-invasive optical imaging modality used to image
biological tissues. In this method, a pulsating laser illuminates a region of tissues to be imaged, which then generates an acoustic wave due to thermal volume expansion. This wave is then sensed using an acoustic sensor such as a piezoelectric transducer and the resultant signal is converted into an imaging using the back projection algorithm. Since different types of tissues have different photo-acoustic properties, this imaging modality can be used for imaging different types of tissues and bodily organ systems.
This study aims at quantifying the process of light conversion into the acoustic signal. Light travels through tissues and gets attenuated (scattered or absorbed) or reflected depending on the optical properties of the tissues. The process of light propagation through tissues is studied using Monte Carlo simulation software which predicts the propagation of light through tissues of various shapes and with different optical properties. This simulation gives the resultant energy distribution due to light absorption and scattering on a voxel by voxel basis.
The Monte Carlo code alone is not sufficient to validate the photon propagation. The success of the Monte Carlo code depends on accurate prediction of the optical properties of the tissues. It also depends on accurately depicting tissue boundaries and thus the resolution of the imaging space. Hence, a validation algorithm has been designed so as to recover the optical properties of the tissues which are imaged and to successfully validate the simulation results. The accuracy of the validation code is studied for various optical properties and boundary conditions. The results are then compared and validated with real time images obtained from the photoacoustic scanner. The various parameters for the successful validation of Monte Carlo method are studied and presented.
This study is then validated using the algorithm to study the conversion of light to sound. Thus it is a significant step in the quantification of the photoacoustic effect so as to accurately predict tissue properties.
|
Page generated in 0.0519 seconds