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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.
81

Prognostic factors for squamous cell cervical cancer : tumor markers, hormones, smoking, and S-phase fraction

Lindström, Annika January 2010 (has links)
Cervical cancer is the second most common malignancy in women worldwide and one of the leading causes of cancer mortality globally. In patients with invasive cervical cancer prognostic factors are of value for the choice of treatment, monitoring of treatment and follow-up. The most important clinical prognostic factors are stage, tumor volume, parametrial infiltration, vascular invasion, lymph node metastases, and distant metastases. An improved estimation of the prognosis of cervical cancer is desirable, especially in early cancer stages. The aim of this research was to study possible associations between tumor markers, female sex steroids, smoking, S-phase fraction (SPF), and prognosis in invasive squamous cell cervical cancer (SCC). The study comprised 190 patients with SCC, stages IB-IV, admitted to the Department of Gynecologic Oncology at Norrland University Hospital in Umeå between September 1984 and October1990. Ten year mortality was estimated. In study I, of a total of 103 patients, it was found that increased tumor growth, measured by the DNA SPF, was associated with elevated serum progesterone and smoking in the premenopasual patients and with aneuploidy in the whole group. In study II, comprising 128 patients, survival length related to hormone levels and SPF was evaluated in women who died of cervical cancer. In both pre- and postmenopausal women, who died of cervical cancer, SPF at or above 12% was correlated with reduced survival. There was significant positive correlation between a low serum estradiol/progesterone ratio and short survival in those premenopausal women who died of cancer (p=0.02). In study III, ten-year follow-up results in 128 women were compared with the expression of ten relevant tumor markers, assessed by immunohistochemistry. The overall ten-year survival rate in patients with low COX-2 and high CD4+ expression was 76%, versus 53% in the remaining women. The survival rate with absent p53 and high COX-2 expression in the tumors was 42%, versus 71%, while the corresponding figure for the combination of high COX-2 intensity and expression of c-myc was 27%, versus 62%. None of the single markers correlated significantly with outcome in the final Cox regression analyses, while five combinations did. Study IV addressed possible associations between selected tumor markers and cofactors in SCC. Ten tumor markers were examined in 128 patients. Smoking habits and previous oral contraceptive use were recorded. Serum estradiol and progesterone levels were evaluated in 80 women. Highly significant associations were found between strong c-myc staining and increased progesterone, low EGFR staining and high serum estradiol, and absence of p53 staining and smoking. There was an association between absence of p53 and high serum progesterone. In study V, LRIG1 expression was studied in 128 patients and was compared with expression of nine other tumor markers, smoking history, hormone levels, and prognosis. LRIG1 appears to be a significant prognostic predictor in early stage SCC, independent of the other tumor markers that were studied.  Diminished expression in advanced cancer stages and the inverse correlation to serum progesterone and smoking indicate that LRIG1 is a tumor suppressor in squamous cell cervical cancer. Conclusion: The results of these studies support a role of progesterone as a promoter of cervical cancer and indicate that smoking is associated with tumor progression. A combination of tumor markers might be of help in prognostic prediction. LRIG1 acts as a tumor suppressor. These findings might contribute towards greater understanding of prognostic prediction of squamous cell cervical cancer.
82

Moléculas séricas relacionadas con la fisiopatología del adenocarcinoma pancreático como posibles marcadores tumorales

Ferri Iglesias, María José 27 September 2012 (has links)
Serum levels of several molecules associated to pancreatic adenocarcinoma (PDAC) pathophysiology are evaluated in this work, in order to determine their diagnostic value, distinguishing between PDAC patients and healthy controls (HC), different gastrointestinal tumours (GIT) and chronic pancreatitis (CP). Plasma mRNA levels in plasma of sialyltransferases (ST3Gal III and ST3Gal IV) could differentiate between HC and PDAC. Moreover, lower levels of ST3Gal III in early stages of PDAC compared to PDAC advanced stages were reported. The Glasgow Prognostic Score (GPS), inflammatory response quantification, differentiated between all the study groups. IGF-1 levels were lower in neoplasic groups of patient vs HC and CP. We assessed the diagnostic capacity of different markers alone or in combination and compared with that of CA 19.9. The best diagnostic capacity was found combining CEA, CA 19.9 and IGF-1 compared with CA 19.9 and it could be useful to distinguish PDAC from CP. / En este trabajo se analizan distintos parámetros séricos relacionados con la fisiopatología del adenocarcinoma pancreático (PDAC), para evaluar su uso como marcadores que permitan distinguir entre pacientes con PDAC y controles sanos (C), otras neoplasias del tracto gastrointestinal (ONEOS) y pancreatitis crónica (PC). La expresión en plasma de sialiltransferasas, ST3Gal III y ST3Gal IV diferencia entre controles y PDAC. Así mismo, los niveles de ST3Gal III permiten diferenciar en PDAC entre estadíos iniciales y metastáticos. El Glasgow Prognostic Score (GPS), medida de la respuesta inflamatoria, diferencia entre todos los grupos del estudio. Los valores de IGF-1 disminuyen en procesos neoplásicos vs C y PC.Se analiza la capacidad diagnóstica de los distintos parámetros individualmente y combinados entre sí respecto al CA19.9. La combinación de CA 19.9, CEA, IGF-1 aumenta la precisión diagnóstica frente al CA19.9 y podría ser útil para distinguir PDAC de PC.
83

Novel nanocarriers for invasive glioma

Munson, Jennifer Megan 08 July 2011 (has links)
The invasive nature of glioblastoma (GBM) represents a significant challenge to the standard of care and contributes to poor clinical outcomes. Invasion of tumors into healthy brain restricts chemotherapeutic access and complicates surgical resection. The central hypothesis of the thesis is that an effective anti-invasive agent can enhance the standard chemotherapeutic response in invasive brain tumors. Through a screen of novel compounds, a new anti-invasive small molecule, Imipramine Blue (IB), was identified. This triphenylmethane compound inhibits invasion of highly invasive glioma in vitro and in vivo. To elicit a response in vivo, Imipramine Blue was liposomally encapsulated to yield better delivery to tumor. Using this formulation, it is shown that IB attenuates invasion of glioma in vivo leading to a more compact tumor in an aggressively invasive rodent glioma model. Further, it is shown that this novel compound binds NADPH oxidases and alters expression of actin regulatory elements to elicit this anti-invasive activity. To test our hypothesis that anti-invasive therapy coupled with chemotherapy will enhance efficacy, nano-IB therapy was followed by liposomally encapsulated doxorubicin (DXR) chemotherapy. Additionally, a co-encapsulated formulation of IB and DXR was developed and tested in vivo. This combination therapy significantly enhanced survival compared to IB or DXR alone, resulting in long-term survival in the syngeneic invasive rat astrocytoma model RT2. It was seen that sequential treatment was more effective than the co-encapsulated treatment indicating a benefit of pre-treating the tumor with the anti-invasive. This thesis demonstrates that novel anti-invasive IB mediated 'containment' of diffuse glioma significantly enhances the efficacy of DXR chemotherapy compared to chemotherapy or anti-invasive therapy alone.
84

Theoretical and experimental development of a ZnO-based laterally excited thickness shear mode acoustic wave immunosensor for cancer biomarker detection

Corso, Christopher David 23 June 2008 (has links)
The object of this thesis research was to develop and characterize a new type of acoustic biosensor - a ZnO-based laterally excited thickness shear mode (TSM) resonator in a solidly mounted configuration. The first specific aim of the research was to develop the theoretical underpinnings of the acoustic wave propagation in ZnO. Theoretical calculations were carried out by solving the piezoelectrically stiffened Christoffel equation to elucidate the acoustic modes that are excited through lateral excitation of a ZnO stack. A finite element model was developed to confirm the calculations and investigate the electric field orientation and density for various electrode configurations. A proof of concept study was also carried out using a Quartz Crystal Microbalance device to investigate the application of thickness shear mode resonators to cancer biomarker detection in complex media. The results helped to provide a firm foundation for the design of new gravimetric sensors with enhanced capabilities. The second specific aim was to design and fabricate arrays of multiple laterally excited TSM devices and fully characterize their electrical properties. The solidly mounted resonator configuration was developed for the ZnO-based devices through theoretical calculations and experimentation. A functional mirror comprised of W and SiO2 was implemented in development of the TSM resonators. The devices were fabricated and tested for values of interest such as Q, and electromechanical coupling (K2) as well as their ability to operate in liquids. The third specific aim was to investigate the optimal surface chemistry scheme for linking the antibody layer to the ZnO device surface. Crosslinking schemes involving organosilane molecules and a phosphonic acid were compared for immobilizing antibodies to the surface of the ZnO. Results indicate that the thiol-terminated organosilane provides high antibody surface coverage and uniformity and is an excellent candidate for planar ZnO functionalization. The fourth and final specific aim was to investigate the sensitivity of the acoustic immunosensors to potential diagnostic biomarkers. Initial tests were performed in buffer spiked with varying concentrations of the purified target antigen to develop a dose-response curve for the detection of mesothelin-rFc. Subsequent tests were carried out in prostate cancer cell line conditioned medium for the detection of PSA. The results of the experiments establish the operation of the devices in complex media, and indicate that the acoustic sensors are sensitive enough for the detection of biomolecular targets at clinically relevant concentrations.
85

Modulating liposomal stealth properties to evade RES and target tumors

McNeeley, Kathleen Margaret 25 August 2008 (has links)
Liposomal nanocarriers offer much promise in chemotherapeutic drug delivery because they may be specifically targeted to tumors thereby shielding healthy organs from toxic side effects of incorporated drugs. Passive targeting of liposomes is achieved through the inclusion of PEG to evade the RES and prolong circulation in the bloodstream. Since tumor vasculature exhibits increased permeability, prolonged circulation results in passive accumulation of liposomes to tumor. Active targeting is accomplished through the inclusion of agents targeted to over-expressed receptors on tumor cells. In vitro studies have demonstrated increased cytotoxicity of actively targeted liposomes due to specific uptake by tumor cells. In vivo, however, actively targeted liposomal nanocarriers have failed to meet the expectations established by the promising outcomes of in vitro studies. This is attributed to the fact that the inclusion of targeting agents results in accelerated clearance from the bloodstream and reductions in passive targeting to tumor thereby offsetting the benefits of active targeting. The central focus of this thesis was to engineer a multi-functional nanoscale drug delivery system which would enable active targeting without compromising RES evasion and passive accumulation to tumor. It was shown that the use of folate in liposomal formulations significantly reduced blood circulation times. To prevent RES recognition of folate on targeted liposomal formulations, a cysteine cleavable phospholipid-PEG conjugate was utilized to "mask" targeting ligands while liposomes were in circulation. Once passive accumulation at the tumor was achieved, cysteine was administered to detach PEG chains, expose folate, and promote uptake by tumor cells. In vivo studies demonstrated that cleavable DSPE-PEG5000 was capable of concealing folate on liposomes to maintain prolonged circulation times. In vitro studies verified the ability to conceal and expose folate on demand, permitting receptor mediated targeting and delivery of drug to target cells. Studies conducted to analyze drug uptake by tumor cells in vivo confirmed that delivery was enhanced when tumor-inoculated animals received targeted liposomes containing cleavable PEG chains followed by a cysteine infusion to expose folate. These results indicate that detachable PEG chains can be used in targeted liposomal formulations to enhance efficacy of chemotherapy in the treatment of glioma.
86

Glicosilació aberrant en proteïnes de secreció com a marcadors tumorals

Tabarés Carreras, Glòria 19 March 2004 (has links)
Als països desenvolupats, una de cada cinc persones morirà a causa del càncer. S'ha descrit que les cèl·lules canceroses presenten modificacions en els glicans presents a la superfície cel·lular i aquesta glicosilació anòmala podria reflectir-se en les glicoproteïnes de secreció. Per aquest motiu es planteja l'estudi de la glicosilació de dues proteïnes de secreció en situació normal i tumoral: la ribonucleasa pancreática humana (RNasa 1) i l'antigen prostàtic específic (PSA).La RNasa 1 és una glicoproteïna secretada majoritàriament pel pàncreas. S'ha desenvolupat un mètode immunològic per a detectar els nivells de RNasa 1 en sèrum. Malgrat la millora de la sensibilitat, respecte d'estudis anteriors, no s'han observat diferències significatives entre la concentració de RNasa 1 en sèrum de pacients control sans, afectats de neoplàsia pancreàtica, de pancreatitis o d'altres patologies.L'estudi de les estructures glucídiques de la RNasa 1, mitjançant assaigs immunològics, permet observar diferències importants en la glicosilació entre la situació normal i tumoral: Els antígens sialilats sLex i sLea només apareixen en la RNasa 1 de medi de cultiu de cèl·lules d'adenocarcinoma pancreàtic Capan-1 i MDAPanc-3 i l'antigen fucosilat Ley només apareix en la RNasa 1 de pàncreas de donant. S'ha purificat la RNasa 1 secretada per la línia MDAPanc-3, cosa que ha permès seqüenciar-ne les estructures glucídiques i comparar-les amb les de la RNasa 1 purificada del medi de les cèl·lules Capan-1 i de pàncreas de donant, corroborant els resultats abans esmentats.L'antigen prostàtic específic (PSA) és una glicoproteïna secretada principalment per la pròstata. Els seus nivells sèrics s'utilitzen actualment com a marcador del càncer de pròstata, però la seva especificitat no permet diferenciar clarament una situació benigna d'una maligna.La purificació i caracterització glucídica del PSA secretat per les cèl·lules de carcinoma prostàtic LNCaP mostren diferències molt clares amb la glicosilació que presenta el PSA purificat de plasma seminal de donant. Principalment, el PSA present en situació tumoral, purificat de les cèl·lules de carcinoma prostàtic, no conté àcid siàlic, però presenta nivells més alts de fucosilació que el PSA en situació normal. El PSA purificat de plasma seminal de donant sí que conté àcid siàlic. Aquests resultats s'han obtingut mitjançant assaigs immunològics amb detecció per lectines i s'han corroborat per seqüenciació glucídica. D'acord amb les estructures glucídiques que millor diferencien el PSA de situació normal i tumoral, s'ha portat a terme la caracterització glucídica de mostres biològiques que contenen PSA. S'han desenvolupat diferents assaigs immunològics de detecció per lectines o associats a l'activitat sialiltransferasa, amb un enriquiment previ en PSA per immunoadsorció indirecta o cromatografia per interacció tiofílica. Els resultats dels diferents assaigs permeten concloure que el PSA del sèrum de pacients de neoplàsia prostàtica presenten un contingut en àcid siàlic similar al del plasma seminal de donant, encara que són lleugerament menys sialilats. Aquests resultats s'adiuen amb els determinats sobre mostres de PSA purificat.La separació del PSA per electroforesi bidimensional mostra diverses formes amb pI àcid en el PSA de plasma seminal, explicades per la presència d'àcid siàlic. Es detecten formes de pI més bàsic que el teòric per al PSA en el secretat per les cèl·lules LNCaP, que correspon a formes pPSA. Al sèrum de pacients de neoplàsia prostàtica s'hi observen formes sialilades.Les proteïnes de secreció, RNasa 1 i PSA, es troben alterades a nivell glucídic en situació tumoral, cosa que podria ser d'utilitat per a finalitats diagnòstiques.
87

Uveal melanoma and macular degeneration : molecular biology and potential therapeutic applications /

Economou, Mario A., January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
88

Molecular alterations in colorectal cancer /

Jansson, Agneta, January 2002 (has links) (PDF)
Diss. (sammanfattning) Linköping : Univ., 2002. / Härtill 4 uppsatser.
89

Prognostic markers in breast cancer associated with cell cycle control, proliferation and angiogenesis /

Lindahl, Thomas, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
90

Differential RNA expression in benign and malignant adrenocortical tumours /

Velázquez-Fernández, David. January 2005 (has links)
Lic.-avh. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 2 uppsatser.

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