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Dissertation (Ph.D.) -- University of Texas Southwestern Medical Center at Dallas, 2008. / Vita. Bibliography: p. 174-213.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Small cells are deployed in a crowded areas with a high demand for both coverage and capacity. It is hard to address both of these requirements simultaneous with a conventional mobile network architecture based on macro cells. In many case a wire is not available to connect the small cell to the core of the mobile network. Under these circumstances a wireless link could be a convenient solution for the backhaul. In this master’s thesis IEEE 802.11n technology was evaluated to assess its suitability for backhaul from a small wireless cell. The performance of wireless equipment manufactured by several vendors has been measured. The results of these measurements were analyzed and compared to a set of requirements established for small cell backhaul. The analysis has affirmed that IEEE 802.11n is capable of providing sufficient performance to be used for small cell backhaul in various deployment scenarios. Note that in this thesis we include femtocells, picocells, wireless LAN access points, and other technologies in the category of "small cells". Another research questions of this master’s thesis is security of small cell backhaul. In addition to protecting the backhaul link itself, the security research investigated the safety of the whole mobile network architecture remodeled with the introduction of small cells. A mechanism to integrate secure small cells into a mobile network was developed. The results obtained during the project will be used as an input for product development activities in the company hosting the project. The resulting product could become the target of future wireless system performance measurements. / Små celler sätts ut i områden med höga krav på täckning och kapacitet. Det är svårt att adressera båda dessa krav samtidigt med en konventionell mobil nätverksarkitektur baserad på makro-celler. I många fall finns ingen kabel tillgänglig att koppla den lilla cellen till kärnan i det mobila nätverket. Under dessa omständigheter kan en trådlös länk vara en lämplig lösning för backhaul. I denna avhandling utvärderas IEEE 802.11n-teknikens lämplighet för backhaul av små celler. Prestandan hos trådlös utrustning tillverkad av flera olika tillverkare har mätts. Resultaten av dessa mätningar analyserades och jämfördes med en mängd krav uppsatta för backhaul av små celler. Analysen har förankrat att IEEE 802.11n är kapabel till att tillhandahålla tillräcklig prestanda för backhaul av små celler i diverse miljöer. Notera att i denna avhandling så inkluderas femto-celler, pico-celler, Wireless LAN-åtkomstpunkter, och andra teknologier i kategorin små celler". Andra forskningsfrågor berörda i avhandlingen är säkerhet vid backhaul av små celler. Utöver att skydda backhaul-länken själv så undersökte säkerhetsforskningen säkerheten av hela mobilnätsarkitekturen när små celler används i arkitekturen. En mekanism för att integrera säkra små celler i ett mobilnät utvecklades. De resultat som införskaffades under projektets genomförande kommer att användas som input till produktutvecklingsaktiviteter hos företaget som sponsrade projektet. Den resulterande produkten skulle kunna bli mål för framtida prestandamätningar av trådlösa system.

Despite improvements in therapy, the prognosis for non-small cell lung cancer (NSCLC) patients remains poor, and cure is only possible in localized tumors after surgical resection. A new generation of targeted cancer drugs has led to the expectation that lung cancer therapy can be significantly improved, but these drugs are today only an option in a small subset of NSCLC patients, and their effect is temporary. Therefore, the aim of this thesis was to characterize NSCLC in order to find new treatment targets and to evaluate biomarkers that further optimize therapy selection. In Paper I, the expression of the potential treatment targets claudin 6 and claudin 18.2 were evaluated based on immunohistochemical- and gene expression analysis. High ectopic protein and gene expression were demonstrated for both claudins in small subgroups of NSCLC. Clinical trials using humanized monoclonal antibodies against both proteins are ongoing in other cancer forms and may be extended to NSCLC. In Paper II, the prognostic impact of the inflammatory mediator cyclooxygenase 2 (COX-2) was evaluated. No prognostic significance was found in a meta-analysis incorporating gene expression data of 1337 NSCLC patients. Likewise, COX-2 protein expression in tumor cells was not associated with survival in two independent NSCLC cohorts. However, in one of the analyzed cohorts, higher COX-2 expression in the tumor stroma was associated with longer survival and may therefore be a subject for further investigation. In Paper III, tumor and stromal COX-2 protein expression was examined in patients treated with the COX-2 inhibitor celecoxib in order to evaluate if COX-2 expression is a predictive biomarker for benefit of celecoxib therapy. Celecoxib did not prolong overall survival neither in the whole cohort nor in patients stratified according to COX-2 expression in tumor or stromal cells. Noteworthy, a tendency towards longer survival was again demonstrated in patients with high COX-2 stromal expression. In Paper IV, the diagnostic methods for identification of ALK rearrangements were assessed in a large representative Swedish NSCLC population. Fluorescence in situ hybridization (FISH), as the diagnostic standard, was compared to two immunohistochemical assays. ALK gene expression levels were incorporated to supplement the molecular data. The frequency of ALK rearrangements was lower than previously reported. The different methods to detect the ALK fusion demonstrated overlapping results. However, the overlap was poor, so the methods cannot be regarded as interchangeable and should thereby be interpreted with caution when used in clinical diagnostics. In summary, this thesis applied an integrative translational approach to characterize potential new treatment targets and to evaluate the detection of existing predictive biomarkers in NSCLC.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Spectrum sharing between Federal and commercial users is a technique proposed by the FCC and NTIA to open up the 3.5 GHz band for wireless broadband use and small cell technology is one of the candidates for its' realization. The traffic on small cells is temporal and their chances of interfering with other services in shared spectrum are limited. DoD has a documented requirement of 865 MHz by 2025 to support telemetry but only 445 MHz is presently available. DoD is conducting researches to realize test and evaluation spectrum efficient technology with the aim to develop, demonstrate, and evaluate technology components required to enable flight and ground test telemetry operations. This paper will provide an overview on spectrum sharing using small cell technology for LTE-Advanced and dynamic spectrum access would be briefly described. Research challenges for protocols and algorithms would be addressed for future studies.

Doctor of Philosophy / Department of Chemistry / Stefan H. Bossmann / Cancer is a group of diseases that are characterized by uncontrolled growth and spread of cells. In order to treat cancer successfully, it is important to diagnose cancers in their early stages, because survival often depends on the stage of cancer detection. For that purpose, highly sensitive and selective methods must be developed, taking advantage of suitable biomarkers. The expression levels of proteases differ from one cancer type to the other, because different cancers arise from different cell types. According to the literature, there are significant differences between the protease expression levels of cancer patients and healthy people, because solid tumors rely on proteases for survival, angiogenesis and metastasis. Development of fluorescence-based nanobiosensors for the early detection of pancreatic cancer and non-small-cell lung cancer is discussed in this thesis. The nanobiosensors are capable of detecting protease/arginase activities in serum samples over a broad range. The functionality of the nanobiosensor is based on Förster resonance energy transfer and surface energy transfer mechanisms. The nanobiosensors for protease detection feature dopamine-coated Fe/Fe₃O₄ nanoparticles, consensus (cleavage) peptide sequences, meso-tetra(4-carboxyphenyl)porphine (TCPP), and cyanine 5.5. The consensus peptide sequences were synthesized by solid-supported peptide synthesis. In this thesis, improved consensus sequences were used, which permit faster synthesis and higher signal intensities. TCPP, which is the fluorophore of the nanoplatform, was connected to the N-terminal end of the oligopeptides while it was still on the resin. After the addition of TCPP, the TCPP-oligopeptide was cleaved off the resin and linked to the primary amine groups of Fe/Fe₃O₄-bound via a stable amide bond. In the presence of a particular protease, the consensus sequences attached to the nanoparticle can be cleaved and release TCPP to the aqueous medium. Upon releasing the dye, the emission intensity increases significantly and can be detected by fluorescence spectroscopy or, similarly, by using a fluorescence plate reader. In sensing of arginase, posttranslational modification of the peptide sequence will occur, transforming arginine to ornithine. This changes the conformational dynamics of the oligopeptide tether, leading to the increase of the TCPP signal. This is a highly selective technology, which has a very low limit of detection (LOD) of 1 x 10⁻¹⁶ molL⁻¹ for proteases and arginase. The potential of this nanobiosensor technology to detect early pancreatic and lung cancer was demonstrated by using serum samples, which were collected from patients who have been diagnosed with pancreatic cancer and non-small cell lung cancer at the South Eastern Nebraska Cancer Center (lung cancer) and the University of Kansas Cancer Center (pancreatic cancer). As controls, serum samples collected from healthy volunteers were analyzed. In pancreatic cancer detection, the protease/arginase signature for the detection of pancreatic adenocarcinomas in serum was identified. It comprises arginase, MMPs -1, - 3, and -9, cathepsins -B and -E, urokinase plasminogen activator, and neutrophil elastase. For lung cancer detection, the specificity and sensitivity of the nanobiosensors permit the accurate measurements of the activities of nine signature proteases in serum samples. Cathepsin -L and MMPs-1, -3, and -7 permit detecting non-small-cell lung-cancer at stage 1.

Angiogenesis, the growth of new blood vessels, is vital to tumour growth. Prevailing dogma has been that tumours cannot grow without angiogenesis. Based on this premise, anti-angiogenic drugs are used clinically. However, the principle of angiogenesis as an absolute requirement for tumour growth has been challenged with reports that many tumours are entirely or partially non-angiogenic. This study describes and quantifies characteristics of non-angiogenic non-small cell lung tumours, demonstrates non-angiogenic growth in small-cell/neuroendocrine lung tumours and investigates the underlying pathogenetic processes by comparison with angiogenic lung tumours. Hypoxia is an important stimulus for angiogenesis. Differences in response to hypoxia may determine whether a tumour produces new vessels. In order to test this, levels of. necrosis, often considered a surrogate marker of hypoxic stress, were quantified but no difference in quantity of necrosis was found Moreover, immunohistochemical investigation of hypoxia and angiogenesis factors provided no unambiguous explanation for the differences in angiogenesis. Significant differences were seen, however, in fibrosis and inflammation, which were both greater in angiogenic tumours. Differences were greater for lymphocytes rather than cells of the ‘innate’ immune system. This provided an alternative hypothesis: angiogenesis occurs during wound healing and in the growth of granulation tissue, so it is possible that tumour angiogenesis is a response to factors produced by immune cells rather than the tumour itself. A tumour’s angiogenic status may, therefore, be determined by the response it provokes from the immune system. Further work to test this theory would compare levels of immunogenic factors such as Tumour Necrosis Factor and tumour cell surface antigens such as the HLA class I molecules. The study concludes with an investigation into the molecular basis of non-angiogenic growth using the technique of comparative genomic hybridisation (CGH) which allows amplifications and deletions of areas of DNA to be calculated. High-resolution array CGH was evaluated against conventional CGH, and the results compared with previous RNA studies from our laboratory. These revealed a set of genes with consistent changes in both RNA and DNA, several of which form part of known angiogenic and inflammatory pathways.

Neuroendocrine tumors of the cervix are extremely rare. Women diagnosed with small cell neuroendocrine carcinoma of the cervix have a higher frequency of metastases in the lymph nodes, lymphovascular invasion, recurrence and worse prognosis compared to those with other types of cervical neoplasia. We report the case of a 58-year-old female, with a history of six years of postmenopausal irregular vaginal bleeding, in addition to symptoms related to chronic anemia. Gynecological examination showed a tumor of 4 cm that occupied the upper third of the vagina and protruded through the cervix initially diagnosed as an abortifacient myoma, and sent to histopathology study. 90% of the tumor was small cell neuroendocrine carcinoma grade III, and the remaining 10% was squamous cell carcinoma. The patient underwent into a radical hysterectomy plus bilateral salpingo-oophorectomy, and bilateral pelvic and para-aortic lymphadenectomy. Histopathologic examination of the surgical specimen found endometrium and myometrium compromised by malignancy. Parametrium, annexes and lymph nodes were free of neoplasia. At microscopy, the result was a grade III neuroendocrine carcinoma (small cell carcinoma, infiltrating), with extensive lymphovascular emboli. The immune-histochemical study showed synaptophysin positive in areas with neuroendocrine differentiation. / Los tumores neuroendocrinos de cuello uterino son extremadamente raros. Las mujeres con diagnóstico de carcinoma neuroendocrino de células pequeñas del cuello uterino tienen mayor frecuencia de metástasis en los ganglios linfáticos, invasión linfovascular, recurrencia y peor pronóstico en comparación con aquellos con otros tipos de neoplasias cervicales. Se presenta el caso de una mujer de 58 años, con un tiempo de enfermedad de seis años antes del ingreso, caracterizado por sangrado vaginal irregular posmenopáusica, además de sintomatología relacionada a anemia crónica. En el examen ginecológico, se evidenció tumoración de 4 cm que ocupaba tercio superior de vagina y protruía por el cérvix. Fue diagnosticado como mioma abortivo y enviada a estudio anatomopatológico. El resultado fue carcinoma neuroendocrino de células pequeñas grado III en el 90% y carcinoma epidermoide en el 10%. La paciente fue sometida a histerectomía radical más salpingo-ooferectomía bilateral y linfadenectomía pélvica bilateral y para-aortica. El estudio anatomopatológico de la pieza quirúrgica encontró endometrio y miometrio comprometido por neoplasia maligna. Parametrios, anexos y ganglios linfáticos se encontraron libres de neoplasia. A la microscopía el resultado fue carcinoma neuroendocrino grado III (carcinoma de células pequeñas, infiltrante), con extensa embolia linfovascular. El estudio de inmunohistoquímica arrojó sinaptofisina positivo en las áreas con diferenciación neuroendocrina.

Pemetrexed (PTX), an antifolate drug, has been approved by the US FDA for first line therapy of mesothelioma and non-small cell lung cancer. In addition to its primary site of action on thymidylate synthase (TS), PTX also inhibits the second folate-dependent enzyme of purine biosynthesis aminoimidazolecarboxamide ribonucleotide formyltransferase (AICART). The accumulation of the substrate for AICART, ZMP, in PTX-inhibited cancer cells leads to activation of AMP-activated protein kinase (AMPK) with subsequent inhibition of mammalian target of rapamycin (mTOR) and hypophosphorylation of its downstream targets responsible for protein synthesis and cell proliferation. Inhibitors of mTORC1 like Rapamycin and its analogs (rapalogs) have only partial effects on tumor cells as they do not inhibit mTORC2, which phosphorylates Akt subsequently relieving the inhibition of mTORC1, thus leading to poor cytotoxicity by rapalogs. AMPK exerts control on mTORC1 kinase activity and PTX mediated activation of AMPK leads to its subsequent downregulation and hence, would be expected to have a therapeutic interaction with direct mTOR inhibitors. AZD8055, an ATP-competitive inhibitor of mTOR kinase, potently inhibits both mTORC1 and mTORC2 and therefore, can overcome the feedback mechanism(s) limiting the action of rapalogs to cytostatic effects. To study the effects of AMPK activation and mTOR inhibition pharmacologically, we performed growth suppression assays using pemetrexed, AICAR, RAD001, and AZD8055. The effect of inhibition of mTOR with these drugs was assessed by examining the dephosphorylation of mTORC1 substrates S6K1 and 4E-BP1, as single agents and in combination, at their 50% inhibitory concentrations (IC50) by western blotting. Our data suggested that AMPK activation via PTX mediated AICART inhibition in combination with direct mTOR inhibition by AZD8055 has a synergistic interaction on the proliferation of NSCLC cells in culture. Inhibition of mTOR endogenously by pemetrexed, along with direct pharmacological inhibition of mTOR prevents the feedback circuit which may compromise the therapeutic efficacy of rapamycin analogs. Pemetrexed and AZD8055, as single agents, demonstrated inhibitory activity on phosphorylation events of mTORC1 substrates. This activity was markedly increased by combining both the drugs. Our findings suggest that direct inhibitors of mTOR enhance the effects of activators of AMPK. These effects appear to be mediated via combined effects on mTORC1. Taken together, the combination of catalytic site mTOR inhibitors and pemetrexed is a promising therapeutic strategy and calls for further preclinical and clinical investigations.