• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 51
  • 11
  • 6
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 78
  • 18
  • 16
  • 15
  • 15
  • 15
  • 14
  • 11
  • 10
  • 9
  • 7
  • 7
  • 6
  • 6
  • 6
  • 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.
71

The therapeutic efficacy of improved α-fetoprotein promoter-mediated tBid delivered by folate-PEI600-cyclodextrin nanopolymer vector in hepatocellular carcinoma. / therapeutic efficacy of improved alpha-fetoprotein promoter-mediated tBid delivered by folate-PEI600-cyclodextrin nanopolymer vector in hepatocellular carcinoma / CUHK electronic theses & dissertations collection

January 2013 (has links)
Hu, Baoguang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 121-143). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
72

Značaj molekularne dijagnostike u dokazivanju virusnog gastrointestinalnog sindroma u Vojvodini / Importance of molecular diagnostics in detection of viral gastrointestinal syndrome in Vojvodina

Patić Aleksandra 14 March 2018 (has links)
<p>Uvod: Virusni gastrointestinalni sindrom je aktuelni zdravstveni problem u celom svetu. To važi kako u razvijenim zemljama, tako i u zemljama u razvoju, a posebno u nerazvijenim zemljama, gde je drugi po redu uzrok mortaliteta. Nagli početak bolesti, praćen pojavom velikog broja tečnih stolica, mukom, povraćanjem, bolovima u stomaku, temperaturom, malaksalo&scaron;ću, ima za posledicu dehidrataciju. U svim starosnim grupama obolelih, a naročito kod sasvim male dece, starih i imunodeficitarnih osoba može da dođe do smrtnog ishoda, ukoliko se brzo ne postavi tačna etiolo&scaron;ka dijagnoza bolesti i ne pristupi se odmah nadoknadi vode i elektrolita, kao i primeni svih ostalih mera simptomatske terapije. Brzo postavljena tačna dijagnoza, &scaron;to se najbolje postiže real-time PCR testom, sprečava pojavu komplikacija, pa i fatalnog ishoda bolesti. Istovremeno, omogućava primenu odgovarajućih epidemiolo&scaron;kih mera da se spreči nastanak epidemija i njihovo &scaron;irenje. Cilj ovog istraživanja bio je da se tačno utvrdi incidenca virusnog gastrointestinalnog sindroma u Vojvodini i učestalost pojave epidemijskog i sporadičnog javljanja ove bolesti. Cilj je bio i postavljanje algoritma za primenu real-time PCR testa u dijagnostici virusnog gastrointestinalnog sindroma u budućem radu. Isto tako, cilj je bio da se molekularnom analizom, sekvenciranjem delova genoma pozitivnih uzoraka stolice, izvr&scaron;i genetska tipizacija i odredi filogenetska pripadnost virusa. Materijal i metode: Tokom petogodi&scaron;njeg istraživanja molekularnim real-time PCR testom pregledane su 1003 obolele osobe sa simptomima virusnog dijarealnog sindroma, starosti od mesec dana do preko 90 godina. Pregledani su na rota, noro, astro i enterične adenoviruse. Na osnovu podataka iz anketnih upitnika i istorija bolesti, detaljno su analizirani svi klinički pokazatelji (javljanje bolesti tokom godine, trajanje bolesti, simptomi). Procena težine kliničke slike vr&scaron;ena je prema Vesikari skali. Svi podaci su upoređivani prema vrsti virusnog uzročnika, prema starosti obolelih, godinama trajanja istraživanja i epidemijskom i sporadičnom javljanju oboljenja. Dobijeni podaci su statistički obrađeni, tabelarno i grafički prikazani. Rezultati: U petogodi&scaron;njem periodu real-time PCR testom pregledan je uzorak od 1003 obolele osobe različite starosti na 4 virusna uzročnika dijarealnog sindroma (rota, noro, astro i enterične adenoviruse). Virusni dijarealni sindrom dokazan je kod 709 obolelih (70,69%). Najče&scaron;će su dokazane rotavirusne infekcije u 28,81%. Statistički značajno najče&scaron;će rotavirusi su bili utvrđeni kod dece do 5 godina (38,90%), ali u visokom procentu i kod dece uzrasta 6 do 14 godina (24,83%). Deca mlađa od 5 godina imala su statistički značajno najtežu kliničku sliku, bila su če&scaron;će hospitalizovana i imala su statistički značajno vi&scaron;u temperaturu. Pored vi&scaron;e temperature kod obolelih od rotavirusa, klinička slika je kod ovih bolesnika bila teža i bolest je duže trajala nego kod obolelih od drugih virusa. Norovirusna infekcija je dokazana u 23,03% obolelih i to statistički značajno če&scaron;će kod odraslih osoba, starijih od 20 godina. Od kliničkih simptoma kod ovih bolesnika statistički značajno če&scaron;će su dokazani muka, povraćanje i bolovi u stomaku, nego kod obolelih od drugih virusa. Norovirusi su značajno če&scaron;će bili uzročnici epidemijskog javljanja bolesti. Astrovirus je dokazan kod znatno manjeg broja obolelih (u 2,29%) i to samo kod dece do 5 godina i dece uzrasta 6 do 14 godina. Infekcija izazvana enteričnim adenovirusima dokazana je kod 13,36% bolesnika. Njače&scaron;će je utvrđena kod dece uzrsta do 5 godina i 6 do 14 godina. Oboleli od adenovirusa imali su statistički značajno blažu kliničku sliku bolesti. Dva virusna uzročnika u uzorku stolice dokazana su u 3,19% osoba, obično u toku epidemijskog javljanja bolesti. Ovi bolesnici su imali bitno težu kliničku sliku. Najvi&scaron;e obolelih od dijarealnog sindroma bilo je u hladnim mesecima, mada su dijagnostikovani i tokom cele godine. U petogodi&scaron;njem periodu utvrđene su 22 epidemije u kolektivima i 9 porodičnih epidemija. Epidemijsko javljanje bolesti bilo je statistički značajno najče&scaron;će kod najstarijih bolesnika (starijih od 50 godina), a sporadično javljanje bilo je statističko značajno najče&scaron;će kod dece. U cilju potvrde tačnosti dijagnostike virusa u ispitivanim uzorcima real-time PCR testom, genotipizacije, kao i detaljnije molekularne analize, izabrani su reprezentativni uzorci pozitivni na rota, noro, astro ili adenoviruse. Delovi genoma ovih uzoraka su amplifikovani, a zatim sekvencirani. Sekvencirani izolati rotavirusa pripadali su grupi A i tipovima G1P[8], G2P[4], G3P[8] i G9P[8]. Sekvencirani izolati norovirusa pripadali su genogrupi I tipu 2, zatim genogrupi II tipovima 1, 2, 4 i 17. Sekvencirani izolati astrovirusa pripadali su grupi klasičnih astrovirusa i tipovima 1, 4 i 5. Sekvencirani izolati adenovirusa pripadali su grupi F i tipovima 40 i 41, kao i grupi C tipu 2. Pripadnost dobijenih sekvenci u ovom istraživanju, dodatno je potvrđena izradom filogenetskog stabla za sekvence pozitivne na rota, noro, astro ili adenoviruse. Zaključak: Incidenca virusnog dijarealnog sindroma u Vojvodini (70,69%) vrlo je visoka i vi&scaron;a je nego &scaron;to je bilo pretpostavljeno prilikom prijave teze (u hipotezi). Real-time PCR test treba da bude redovno kori&scaron;ćen u budućem dijagnostičkom radu, jer dovodi do brze dijagnostike, čak i ako su virusi prisutni u malom broju u uzorcima tečnih stolica, &scaron;to je utvrđeno tokom ovog dijagnostičkog rada. Ispitivani virusi treba da budu redovno dijagnostikovani kod obolelih od dijarealnog sindroma i to u svim starosnim grupama, tokom epidemijskog i sporadičnog javljanja oboljenja.</p> / <p>Introduction: Viral gastrointestinal syndrome is a current ongoing health problem worldwide. This is true of both developed and developing countries, especially underdeveloped ones where it is the second leading cause of mortality. Sudden onset of the disease&mdash;accompanied by the occurrence of large numbers of liquid stools, nausea, vomiting, abdominal pain, fever, and exhaustion&mdash;leads to dehydration. A fatal outcome can occur in all age groups of patients, especially very young children, the elderly, and the immuno-deficient, unless an accurate etiological diagnosis of the disease is quickly established, followed by a prompt institution of fluid and electrolyte placement, and implementation of other symptomatic therapy measures. Quick establishment of an accurate diagnosis, which is best achieved using the real-time PCR test, prevents the onset of complications, including a potentially fatal outcome of the disease. Simultaneously, it enables the implementation of appropriate epidemiological measures to prevent epidemic outbreaks and their spread. The aim of this study was to accurately determine the incidence of viral gastrointestinal syndrome in Vojvodina and the frequency of epidemic and sporadic occurrence of this disease. The aim was also to set up an algorithm for the application of the real-time PCR test in diagnostics of viral gastrointestinal syndrome in future work. Likewise, the aim was to carry out genetic typing and determine phylogenetic affiliation of the virus using molecular analysis and sequencing of parts of genomes from positive stool samples. Material and Methods: During a five-year study, 1003 patients with symptoms of viral diarrheal syndrome, aged from one month to more than 90 years old, were examined using molecular real-time PCR test. They were screened for rota, noro, astro, and enteric adenoviruses. Based on the data from survey questionnaires and medical case history, all clinical indicators were meticulously analyzed (disease occurrence during the year, disease duration, symptoms). The assessment of the clinical severity was carried out according to the Vesikari Clinical Severity Scoring scale. All data were compared according to the type of the viral causing agent, age of the patients, duration of research in years, and epidemic and sporadic occurrence of the disease. Obtained data were statistically analyzed, tabulated, and graphically displayed. Results: In a five-year period, a sample of 1003 patients of different ages was screened for four different viral causing agents of diarrheal syndrome (rota, noro, astro, and enteric adenoviruses) using the real-time PCR test. Viral diarrheal syndrome was confirmed in 709 patients (70.69%). The most commonly found were rotavirus infections in 28.81% of the cases. Rotaviruses were statistically significantly most common in children younger than 5 years old (38.90%), but were also found in high percentage in children aged 6-14 years old (24.83%). Children under 5 years of age had statistically significantly highest clinical severity and fever, and were more frequently hospitalized. In addition to higher fever in patients with rotavirus, clinical severity in these patients was also higher, and the disease lasted longer than in patients with other viruses. Norovirus infections were reported in 23.03% of the subjects, statistically significantly more frequently in adults over 20 years of age. Regarding the clinical symptoms in these patients, nausea, vomiting, and abdominal pain were statistically significantly more common than in patients with other viruses. Noroviruses were significantly more common as causing agents of epidemic disease outbreaks. Astrovirus was found in a significantly smaller number of patients (in 2.29%), and only in children under 5 years of age and children aged 6-14 years old. Enteric adenovirus infections were reported in 13.36% of the subjects. They were most commonly found in children younger than 5, and those aged 6- 14 years old. Adenovirus sufferers had statistically significantly milder clinical disease. Two viral causing agents in the stool sample were found in 3.19% of the subjects, usually during an epidemic disease outbreak. These patients had a significantly more severe clinical disease. Highest numbers of sufferers from diarrheal syndrome occurred during the cold months, although they were diagnosed throughout the year. In a five-year period, 22epidemics in collective groups and 9 family epidemics were identified. Epidemic outbreaks of the disease were statistically significantly most frequent in the elderly patients (older than 50), while sporadic occurrences were statistically significantly most frequent in children. Representative samples positive for rota, noro, astro, or adenoviruses were selected in order to confirm the accuracy of virus diagnostics in samples tested by the real-time PCR test, and perform genotyping as well as more detailed molecular analyses. Parts of the genomes of these samples were amplified and then sequenced. Sequenced rotavirus isolates belonged to group A and types G1P[8], G2P[4], G3P[8], and G9P[8]. Sequenced norovirus isolates belonged to genogroup I type 2, and genogroup II types 1, 2, 4, and 17. Sequenced astrovirus isolates belonged to the group of classical astroviruses and types 1, 4, and 5. Sequenced adenovirus isolates belonged to group F and types 40 and 41, as well as group C type 2. The affiliation of the obtained sequences in this study was further confirmed by creating a phylogenetic tree for sequences positive for rota, noro, astro, or adenoviruses. Conclusion: The incidence of viral diarrheal syndrome in Vojvodina (70.69%) is very high&mdash;higher than what was assumed at the time of the thesis submission (in the hypothesis). The real-time PCR test should be regularly used in future diagnostic work, since it leads to rapid diagnostics even if viruses are present in small numbers in liquid stool samples, as determined in the course of this diagnostic study. The investigated viruses should be regularly tested in patients with diarrheal syndrome belonging to all age groups during both epidemic and sporadic occurrences of the disease.</p>
73

Mechanisms involved in adenovirus binding to and infection of host cells

Nyberg, Cecilia, January 2009 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 4 uppsatser. Även tryckt utgåva.
74

Protein processing strategies by adeno-associated virus type 5 (AAV5) and the effects of the adenovirus E4orf6/E1b-55k/Cullin 5 E3 ubiquitin ligase complex on AAV protein stability

Farris, Kerry David, Pintel, David J. January 2008 (has links)
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). Vita. Thesis advisor: David Pintel "August 2008" Includes bibliographical references
75

Pesquisa de vírus entéricos humanos em lodos de esgoto originários de duas ETEs do Estado de São Paulo: estabelecimento e avaliação de metodologia para recuperação e detecção viral. / Detection of human enteric viruses in sewage sludge from two sewage treatment plants in São Paulo state: establishment and evaluation of a method for viral recovery and detection.

Karina Medici Barrella 10 June 2008 (has links)
O objetivo foi desenvolver e avaliar uma metodologia simplificada para detecção de vírus entéricos humanos em lodo de esgoto. O método foi baseado em eluição viral com solução protéica, seguida de ultracentrifugação. Alguns parâmetros foram avaliados (tempo e pH de eluição, condições de clarificação e purificação). A seguir, foi aplicado à pesquisa de adenovírus, vírus da hepatite A e norovírus em amostras colhidas ao longo de 12 meses em duas ETEs do estado de São Paulo. Amostras pareadas de esgoto foram também examinadas como referência da presença viral. A detecção viral por PCR, RT-PCR e PCR em tempo real, revelou a presença de adenovírus, incluindo os entéricos (espécie F) e vírus da hepatite A tanto nas esgoto como no lodo de ambas as ETEs. Norovírus não foram detectados. Vírus infecciosos não foram detectados no lodo submetido ao tratamento químico (ETE A). Parte dos vírus presentes na água de esgoto ficaram retidos no lodo e análises estatísticas revelaram que o tratamento químico adotado na ETE A é eficiente para a inativação viral. / The aim was to develop and evaluate a simplified methodology for detection of human enteric viruses in sewage sludge. The method was based on viral elution with protein solution, followed by ultracentrifugation. Several parameters were evaluated, including time and elution pH, clarifying and purifying conditions. The method was applied to the detection of adenoviruses, hepatitis A virus and noroviruses in sewage sludge samples collected for twelve months at two sewage treatment plants in Sao Paulo state. Raw sewage samples were also collected as a reference for viral presence. PCR, RT-PCR and Real-Time PCR revealed the presence of adenoviruses, including the enteric ones (species F) and hepatitis A virus found both in sewage and sludge. Noroviruses were not detected in any samples. Cell culture infectious viruses were not detected in the sludge subjected to chemical treatment (STP A), and statistical analyses revealed the efficiency of this treatment for virus inactivation.
76

Otimização do método de floculação orgânica de concentração viral para avaliação do impacto de tratamento por lodo ativado na Estação de Tratamento de Esgoto Barbosa Lage, Juiz de Fora - Minas Gerais

Assis, Andrêssa Silvino Ferreira 19 December 2016 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-13T17:29:42Z No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-13T19:33:58Z (GMT) No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) / Made available in DSpace on 2017-03-13T19:33:58Z (GMT). No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) Previous issue date: 2016-12-19 / O tratamento de esgoto pode ser insuficiente para a completa eliminação de vírus entéricos, tais como adenovírus humanos (HAdV) e rotavírus do grupo A (RVA). Portanto, o retorno do lodo e do efluente tratado ao ambiente pode representar riscos à saúde pública. Este estudo foi conduzido para otimizar um protocolo de floculação orgânica para recuperação viral a partir de lodo de esgoto e efluente tratado, bem como realizar um monitoramento de HAdV e RVA na estação de tratamento de esgoto (ETE) de Juiz de Fora, MG. Nos estudos de otimização, foram propostas adaptações no protocolo de floculação com leite desnatado para lodo e efluente tratado, com modificações no tempo de agitação da amostra, na concentração final de leite desnatado e/ou na etapa de centrifugação. No estudo de monitoramento, esgoto bruto (P1), esgoto primário (P2), lodo (P3) e efluente tratado (P4) foram coletados bimensalmente em 2014 (durante as épocas seca e chuvosa), totalizando 96 amostras (simples e compostas). As cargas virais foram determinadas por PCR quantitativo e o bacteriófago PP7 foi usado como controle interno. Amostras de HAdV e RVA foram submetidas ao sequenciamento e a viabilidade das partículas de HAdV foi avaliada em amostras de P4. Os parâmetros físico-químicos e a contagem de coliformes termotolerantes (CT) foram determinados em cada ponto. Nos estudos de otimização, foram selecionadas duas condições que apresentaram as maiores taxas de recuperação viral no lodo (menor tempo de agitação e maior concentração de leite desnatado) e no efluente tratado (sem primeira etapa de centrifugação e com maior concentração de leite desnatado). Ambas provaram ser ferramentas úteis para pesquisa viral em amostras de campo, inclusive para a pesquisa de vírus gigantes. No monitoramento, o HAdV foi detectado em 85,4% (82/96) dos concentrados, com cargas virais variando de 3,27 x 102 a 2,42 x 106 cópias do genoma por mililitro (cg/mL), ao longo do ano. A presença de RVA foi observada em 52,1% (50/96) dos concentrados (1,38 x 103 a 3,65 x 105 cg/mL), com maior detecção na época seca. A carga viral não foi influenciada pelo tipo de amostra, sendo detectada tanto em amostras simples, quanto em amostras compostas. Todas as amostras de HAdV sequenciadas pertenciam à espécie F tipo 41 e as amostras de RVA pertenciam ao genótipo I1. O tratamento de esgoto reduziu a quantidade de matéria orgânica e sólidos, bem como a contagem de CT e as cargas virais. No entanto, a presença de HAdV e RVA foi observada mesmo após o tratamento, inclusive em amostras de efluente tratado consideradas adequadas pelas legislações atuais, com detecção de partículas infecciosas de HAdV. Foram observadas correlações positivas entre a carga viral e a demanda bioquímica de oxigênio, os sólidos sedimentáveis e sólidos suspensos totais. Os dois protocolos otimizados neste estudo podem ser facilmente adequados para uso em laboratório de rotina, podendo impulsionar o monitoramento viral nos subprodutos gerados na ETE. A carga viral detectada na ETE salienta a disseminação ambiental de RVA e HAdV e aponta o potencial do HAdV como um marcador viral de contaminação em ambientes aquáticos. / Sewage treatment may be insufficient for the complete elimination of enteric viruses such as human adenoviruses (HAdV) and group A rotaviruses (RVA). Thus, the return of sewage sludge and treated effluent to the environment poses concerns potential for public health. This study was conducted to optimize an organic flocculation procedure for viral recovery from sludge and treated effluent, and carry out a surveillance of HAdV and RVA in a wastewater treatment plant (WWTP) at Juiz de Fora, MG. In optimization studies, conditions were proposed for sludge and treated effluent with changes in the stirring time, in the final concentration of skimmed-milk and/or in the centrifugation step. In surveillance study, raw sewage (P1), primary sewage (P2), sludge (P3) and treated effluent (P4) were collected bimonthly in 2014 (during the dry and the rainy season), totaling 96 samples (simple and composite). Quantitative PCR determined viral loads and PP7 bacteriophage was used as internal control. HAdV and RVA strains were selected for sequencing, and the HAdV viability was evaluated in P4 samples. Physicochemical parameters and thermotolerant coliforms (TC) counting were determined at each point. After the optimization studies, two conditions were selected: the ones that showed the highest viral recovery rates in sludge (lower stirring time and higher concentration of skimmed-milk) and treated effluent (without the first centrifugation step and with a higher concentration of skimmed-milk). These conditions proved to be a useful tool for viral search in the field samples, including for the research of giant virus. In surveillance study, HAdV was detected in 85.4% (82/96) of the concentrated, with viral loads ranging from 3.27 x 102 to 2.42 x 106 genome copies per milliliter (gc/mL), throughout the year. RVA presence was observed in 52.1% (50/96) of the samples (1.38 x 103 to 3.65 x 105 gc/mL) with detection greater in the dry season. Viral load was not influenced by the type of sample being detected both in single samples, as in composite samples. All the sequenced HAdV strains belonged to species F type 41, and RVA strains belonged to genotype I1. Sewage treatment reduced the content of organic matter and solids, as well as the TC counts and the viral loads. However, the presence of HAdV and RVA was observed after treatment, even in samples considered adequate by current laws with detection of infectious HAdV particles. Positive correlations were observed between viral load and biochemical oxygen demand, sedimented solids and total suspended solids. Two optimized protocols in this study are easily suitable for routine laboratory use and can boost viral monitoring in by-products generated in the WWTP. Viral load detected in WWTP stress the environmental dissemination of HAdV and RVA and addressed the potential of HAdV as a virological marker of contamination in aquatic environments.
77

Therapeutic effect of adenovirus- and α-fetoprotein promoter-mediated tBid and chemotherapeutic agents in combination on orthotopic hepatocellular carcinoma in mice. / Therapeutic effect of adenovirus- and alpha-fetoprotein promoter-mediated tBid and chemotherapeutic agents in combination on orthotopic hepatocellular carcinoma in mice / CUHK electronic theses & dissertations collection

January 2010 (has links)
Hepatocellular carcinoma (HCC) is the third commonest cancer worldwide. However HCC is considered to be highly resistant to chemotherapy. Gene therapies aimed to regulate Bd-2 proteins may sensitize HCC cells to chemotherapy. Studies have demonstrated that Bid/tBid are crucial in hepatocyte apoptosis. Bid also plays important roles in the development and chemotherapeutic sensitivity of HCC. The objective of this study is to test effect of Ad/AFPtBid and chemotherapeutic agents in combination on an orthotopic HCC model. / In conclusion, (1) Ad/AFPtBid can specifically target and effectively suppress the AFP-producing HCC. (2) Ad/AFPtBid can significantly sensitize HCC to 5-FU, their combination can significantly increase the anti-tumor effectiveness. (3) Ad/AFPtBid shows little toxicity in vivo. (4) The complementary effect of tBid and 5-FU on different phases of the cell cycle may explain the better therapeutic result if both are used to treat HCC. (5) The elucidation of phase specific effect of tBid points to a possible therapeutic option that combines tBid with different phase specific agents to treat HCC. / It is well established that many apoptosis inducers act in a cell cycle-specific fashion. This leads us to hypothesize that tBid might have phase specific effect. So, we tested the susceptibility of Hep3B cells at 00/01, S or G2/M phases to tBid. The results revealed that tBid significantly reduced Hep3B cells in G0/G1 phase, increased cells in G2/M phase. On the contrary, 5-FU arrested Hep3B cells in G0/G1 phase, and significantly reduced cells in G2/M phase. The levels of cell cycle-related proteins were altered in line with the result of the cell cycle. This suggests Hep3B cells in G0/G1 phase may be more susceptible to tBid. The complementary effects tBid and 5-FU on different phases of the cell cycle may explain the better therapeutic result if both are used to treat HCC. / The mice bearing orthotopic HCC tumors were treated with Ad/AFPtBid alone or in combination with 5-FU/Dox. Serum AFP levels were measured to mornitor tumor progression. The mice were killed four weeks after treatment. Liver tissues were subjected to immunohistochemical staining of proliferation cell nuclear antigen (PCNA) and TUNEL staining. Another batch of mice was observed for survival rate over a six month period. In addition, possible side effects of Ad/AFPtBid were tested in BALB/c mice. Results demonstrated that Ad/AFPtBid significantly inhibited Hep3B tumor growth. The combination of Ad/AFPtBid with 5-FU was more effective in tumor regression than either agent alone. However, the combination of Ad/AFPtBid with Dox treatment failed to demonstrated better effect than Dox treatment alone because the mice that received Dox exhibited serious weight loss. Tumor tissues from Ad/AFPtBid alone or combination treatment groups showed a decrease in cells positive for PCNA, and an increase in apoptosis by TUNEL staining, indicating that Ad/AFPtBid induced tumor regression through its pro-apoptotic effect. Inflammatory cell infiltration was also increased. Furthermore, Ad/AFPtBid did not suppress the hepatic tumor formed by non-AFP producing SK-HEP-1 or DLD-1. Finally, Ad/AFPtBid and 5-FU in combination results in better survival rate. No acute toxic effect of Ad/AFPtBid was observed. / Ma, Shihong. / "December 2009." / Adviser: CHEN Gong George. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 114-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
78

Preclinical evaluation of immunostimulatory gene therapy for pancreatic cancer

Eriksson, Emma January 2017 (has links)
Pancreatic cancer is characterized by its desmoplastic tumor microenvironment and the infiltration of immunosuppressive cells. It is a devastating disease where most patients are diagnosed at a late stage and the treatment options are few. The development of new treatments is surly needed. One treatment option explored is the use of immunotherapy with the intent to activate the immune system and change the balance from pro-tumor to anti-tumor. This thesis presents the idea of using oncolytic adenoviruses called LOAd-viruses that are armed with immunostimulatory- and microenvironment-modulating transgenes. For effective treatment of pancreatic cancer, the virus needs to be able to be given in addition to standard therapy, the chemotherapy gemcitabine. In paper I, the immunomodulatory effect of gemcitabine was evaluated in blood from pancreatic cancer patients receiving their first 28-day cycle of treatment with infusions day 1, 8 and 15 followed by a resting period. Gemcitabine reduced the level of immunosup-pressive cells and molecules but the effect did not last throughout the resting period. On the other hand, gemcitabine did not affect the level or proliferative function of effector T cells indicating that gemcitabine could be combined with immunotherapy. The LOAd700 virus expresses a novel membrane-bound trimerized form of CD40L (TMZ-CD40L). In paper II, LOAd700 showed to be oncolytic in pancreatic cancer cell lines as well as being immunostimulatory as shown by its capacity to activate dendritic cells (DCs), myeloid cells, endothelium, and to promote expansion of antigen-specific T cells. In paper III, LOAd703 armed with both 4-1BBL and TMZ-CD40L was evaluated. LOAd703 gave a more profound effect than LOAd700 on activation of DCs and the virus was also capable of reducing factors in stellate cells connected to the desmo-plastic and immunosuppressive microenvironment. In paper IV, LOAd713 armed with TMZ-CD40L in combination with a single-chain variable fragment against IL-6R was evaluated. The virus could kill pancreatic cancer cells lines through oncolysis and could also reduce factors involved in desmoplasia in stellate cells. Most interestingly, LOAd713 could reduce the up-regulation of PD-1/PD-L1 in DCs after CD40 activation. Taken together, LOAd703 and LOAd713 seem to have interesting features with their combination of immunostimulation and microenvironment modulation. At present, LOAd703 is evaluated in a clinical trial for pancreatic cancer (NCT02705196).

Page generated in 0.0912 seconds