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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.
71

Prevalência e determinação dos sorotipos circulantes de Streptococcus pneumoniae em crianças que frequentam creches no município de Goiânia-GO / Prevalence and determination of current serotypes of Streptococcus pneumoniae in children attending in day care centers in Goiânia-GO

Guerreiro, Tainá Carvalho 08 July 2015 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-09T13:25:07Z No. of bitstreams: 2 Dissertação - Tainá Carvalho Guerreiro - 2015.pdf: 1793254 bytes, checksum: b06a919b2f95dde4661fe77445d3668c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-09T13:27:31Z (GMT) No. of bitstreams: 2 Dissertação - Tainá Carvalho Guerreiro - 2015.pdf: 1793254 bytes, checksum: b06a919b2f95dde4661fe77445d3668c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-09T13:27:31Z (GMT). No. of bitstreams: 2 Dissertação - Tainá Carvalho Guerreiro - 2015.pdf: 1793254 bytes, checksum: b06a919b2f95dde4661fe77445d3668c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-07-08 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Streptococcus pneumoniae remains as a major cause of childhood morbidity and mortality worldwide, especially in developing countries. Nasopharyngeal colonization is the key of the development of pneumococcal diseases as well as for horizontal spread of this pathogen in the community. Children are the main reservoir of S. pneumoniae and act as vectors in the transmission chain of this microorganism. Pneumococcal conjugate vaccines protect against pneumococcal disease caused by vaccine serotypes, also contributes to the protection against colonization by the same serotypes. In 2010, PCV10 was introduced in the childhood immunization program of Brazil. This is a population-based study that was conducted immediately after the introduction of the vaccine in order to determine the carriage rate of this pathogen in children attending in day care centers in Goiania. These data may be used as a predictor for evaluating the dynamic of the circulating serotypes into the community after the vaccine introduction. Between October and November 2010, nasopharyngeal swabs were collected from 853 children ranging from 36 to 59 months attending in day care centers in Goiania. Isolation and identification of S. pneumoniae were done after the incubation step on broth-enriched for 6 h and posterior plating on blood agar. Isolates that were α-haemolytic, optochin-sensitive and soluble in bile were identified as S. pneumoniae. The isolates were serotyped by cmPCR. The database had been built with the statistical program SPSS (Chicago, IL, USA) version 18.0. The possible risk factors were assessed by multivariate Poisson regression. The level of probability of 0.05 (two-tailed) was used to determine statistical significance. The prevalence of pneumococcus carrier was 57.6% (CI95%: 54.2% - 60.9%). According to the multivariate Poisson regression analysis, children aged 36-47 months (IRR: 1.117; CI95%: 1.007-1.238; p: 0.035) and children in whose houses had four or more residents (IRR: 1.1214; CI95%: 1.078-1.368; p 0.001) were considered risk factors independently associated to pneumococcal colonization. The variable family income equal to or greater than three minimum wages was considered a protective factor independently associated to pneumococcal colonization (IRR: 0.787; CI95%: 0.627-0.990; p 0.041). The most prevalent serotypes and serogroups founded were 6A/6B/6C/6D (n=80; 16.3%), 14 (n=47; 9.6%), 23F (n=46; 9.4%), 19F (n=43; 8.8%), 15B/15C (n=30; 6.1%), 11A/11D (n=28; 5.7%), 3 (n=22; 4.5%) and 19A (n=16; 3.3%). Our results showed a high prevalence of pneumococcal colonization among the study population, indicating that colonization by this microrganism is common among children, especially in environments that favor crowding. The main serotypes/serogroups are cover by PCV10. / Streptococcus pneumoniae é o patógeno responsável pelas maiores taxas de morbidade e mortalidade em crianças, principalmente em países em desenvolvimento. A colonização da nasofaringe é a chave para o desenvolvimento das doenças pneumocócicas, bem como para a transmissão horizontal desse patógeno na comunidade. Crianças são o principal reservatório de S. pneumoniae e atuam como vetores dentro da cadeia de transmissão desse microrganismo. As vacinas pneumocócicas conjugadas (PCV) protegem contra as doenças pneumocócicas causadas pelos sorotipos vacinais, atuando também na proteção contra a colonização pelos mesmos sorotipos. Em 2010, o Brasil introduziu a PCV10 no programa de imunização infantil. Este trabalho é um estudo de base populacional que foi conduzido imediatamente após a introdução da PCV10 para determinar a taxa de portador desse patógeno em crianças não vacinadas que frequentam creches no município de Goiânia. Esses dados poderão ser utilizados como linha de base epidemiológica para avaliação da dinâmica dos sorotipos circulantes na comunidade após a introdução da vacina. Foram coletados, nos meses de outubro e novembro de 2010, 853 swabs de secreção da nasofaringe em crianças entre 36 a 59 meses que frequentavam creches no município de Goiânia. Para o isolamento e identificação de S. pneumoniae as amostras foram incubadas por 6 h em caldo enriquecido e semeadas em ágar sangue. Colônias α-hemolíticas sensíveis à optoquina e à bile foram identificadas como S. pneumoniae. Os isolados foram sorotipados por PCR multiplex convencional. A base de dados foi construída com o programa estatístico SPSS (Chicago, IL, USA) versão 18.0. Os possíveis fatores de risco foram avaliados por regressão de Poisson multivariada. O nível de probabilidade de 0,05 (bi-caudal) foi utilizado para determinar a significância estatística. A prevalência de portador do pneumococo foi de 57,6% (IC95%: 54,2% - 60,9%). De acordo com a análise multivariada crianças com idade entre 36-47 meses de idade (IRR: 1,117; IC95%:1,007 – 1,238; p= 0,035) e crianças em cujos domicílios haviam quatro ou mais pessoas residentes (IRR: 1,1214; IC95%: 1,078 – 1,368; p= 0,001) foram considerados fatores de risco independentemente associados para a colonização pneumocócica. A variável renda familiar igual ou superior a três salários mínimos foi considerada um fator protetor independentemente associado para a colonização pneumocócica (IRR: 0,787; IC95%: 0,627 – 0,990; p= 0,041). Os sorotipos/sorogrupos mais prevalentes foram 6A/6B/6C/6D (n=80; 16,3%), 14 (n=47; 9,6%), 23F (n=46; 9,4%), 19F (n=43; 8,8%), 15B/15C (n=30; 6,1%), 11A/11D (n=28; 5,7%), 3 (n=22; 4,5%) e 19A (n=16; 3,3%). Nossos resultados mostraram uma alta prevalência de colonização por pneumococo entre a população estudada, indicando que a colonização por esse microrganismo é comum entre crianças, principalmente em ambientes que favorecem a aglomeração. Os principais sorotipos/sorogrupos encontrados são contemplados pela PCV10.
72

The study of Epstein-Barr virus encoded microRNAs in nasopharyngeal carcinoma cells. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Based on matching analysis between different EBV strains, we found two nucleotide variations in miR-BART21 and four nucleotide changes in miR-BART22. Interestingly, two nucleotide variations upstream of mature miR-BART22 likely favor its biogenesis by Drosha/DGCR8 processing and we experimentally confirmed this augmentation by in-vitro Drosha digestion, and thus may underline the high and consistent expression of miR-BART22 in NPC tumors. / Infection with the Epstein-Barr virus (EBV) is a strong predisposing factor in the development of nasopharyngeal carcinoma (NPC). Many viral gene products including EBNA1, LMP1 and LMP2 have been implicated in NPC tumorigenesis, although the de novo control of these viral oncoproteins remain largely unclear. / MicroRNAs (miRNAs) are a class of small, non-coding RNAs with a size around 18--24 nucleotides with significant roles in regulating gene expression by either transcriptional silencing or translational suppression. As gene regulators, recent miRNA studies have emphasized the contribution of aberrant miRNA expression in cancer development. The recent discovery of EBV encoded viral miRNAs (ebv-miRNAs) in lymphoid malignancies has prompted us to examine the NPC-associated EBV miRNAs. In this study, we have systematically examined the NPC associated EBV genome for viral-encoded miRNA expression. By constructing small cDNA libraries from a native EBV positive NPC cell line (C666-1) and a xenograft (X2117), we screened about 3000 clones and detected several small EBV fragments, within which two novel ebv-miRNAs in the BARTs region were identified. These two newly identified miRNAs, now named miR-BART21 and miR-BART22, were proven to be abundantly expressed in most NPC samples by both Northern blot and QRT-PCR analysis. / Taken together, this thesis shows that two newly identified EBV-encoded miRNAs are highly expressed in latent EBV infection in NPC. Frequent expression of miR-BART22 can be explained partially by a specific EBV strain that is associated with NPC in our locality. Our findings emphasize the role of miR-BART22 in modulating LMP-2A expression. Because LMP-2A is a potent immunogenic viral antigen that is recognized by the cytotoxic T cells (CTLs), down-modulation of LMP-2A expression by mir-BART22 may permit escape of EBV-infected cells from host immune surveillance. / We attempted to predict the potential viral and cellular targets of miR-BART21 and miR-BART22 by public available computer programs, miRanda and RNAhybrid. A number of potential cellular mRNA targets were suggested, although many failed to be validated by luciferase reporter assay. However, we found a putative miR-BART22 binding site in the LMP2A-3'UTR. Although the LMP-2A transcript is consistently detected in NPC, only 6 out of 26 (23%) primary NPC tumors show weak LMP-2A expression by immunohistochemistry (IHC). The expression levels of miR-BART22 and LMP-2A mRNA have also been determined in eleven of these tumors. Interestingly, the LMP-2A mRNA expression level did not directly correlate with protein expression, and relatively low expression levels of miR-BART22 miRNA were observed in all 3 LMP-2A positive-primary tumors. The suppressive effect of miR-BART22 on LMP-2A was also experimentally validated by a series of dual luciferase reporter assays using reporter constructs containing the putative or mutated recognition site at the LMP-2A 3'UTR. By co-transfection of different amounts of miR-BART22 with the LMP-2A-3'UTR expression vector in reporter assay, we confirmed that miR-BART22 suppressed the LMP-2A protein level in a dose-dependent manner. Furthermore, transfection of miR-BART22 into HEK293 cells that had been stably transfected with pcDNA3.1-LMP-2A, which contains a complete LMP-2A ORF and 3'UTR, readily suppressed levels of the LMP-2A protein. / Lung, Wai Ming Raymond. / Adviser: To Ka Fai. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 197-226). / 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.
73

Identification of novel candidate tumor suppressor genes at 11q and 15q for esophageal squamous cell carcinoma and nasopharyngeal carcinoma via integrative cancer epigenetics and genomics. / 通過整合擬遺傳學與基因組學策略在食管鱗狀細胞癌及鼻咽癌中鑒定位於人類11及15號染色體長臂上的新候選抑癌基因的研究 / CUHK electronic theses & dissertations collection / Tong guo zheng he ni yi chuan xue yu ji yin zu xue ce lüe zai shi guan lin zhuang xi bao ai ji bi yan ai zhong jian ding wei yu ren lei 11 ji 15 hao ran se ti chang bei shang de xin hou xuan yi ai ji yin de yan jiu

January 2010 (has links)
In brief, mRNA expression profiling of candidate genes in each locus was performed using semi-quantitative RT-PCR in a panel of ESCC and NPC cell lines, normal tissues and immortalized epithelial cell lines. Genes downregulated in cancer cells but with high expression in normal tissues and immortalized epithelial cells were subjected to promoter methylation analysis using methylation-specific PCR (MSP), bisulfite genomic sequencing (BGS) and pharmacological demethylation treatment. Genes with tumor-specific downregulation and methylation were further selected as candidates and their tumor suppressive roles were verified via functional studies. / In conclusion, RAB39 and WDRX, epigenetically silenced in multiple cancer cell lines, were identified as novel TSG candidates in this study. Meanwhile, the tumor suppressive functions of ADAMTS8 were further validated, proving the efficiency of this integrative approach. Further study on these novel TSG candidates may help to elucidate the detailed molecular mechanisms for ESCC and NPC, and provide novel therapeutic targets and biomarkers. / In this study, RAB39 and WDRX were identified as candidate TSGs in 11q22.3 and 15q21.3, respectively. Both genes were broadly expressed in normal tissues and immortalized epithelial cell lines, but significantly downregulated and methylated in multiple cancer cell lines. Demethylation treatment with 5-Aza-2'-deoxycytidine restored their mRNA expression, indicating that CpG methylation directly contributed to their transcriptional inactivation. Methylation of RAB39 and WDRX was detected in primary ESCC and NPC, but rarely observed in normal tissues, implicating that their tumor-specific methylation might be used as biomarkers. Ectopic expression of both genes significantly inhibited the clonogenicity of multiple cancer cell lines, supporting their potential roles as functional TSGs. Moreover, WDRX repressed WNT/beta-catenin signaling, underscoring a possible anti-tumorigenic mechanism for it. In addition, ADAMTS8 was revealed to inhibit clonogenicity of NPC and ESCC cell lines, acting as a negative modulator for ERK pathway and a potential pro-apoptotic metalloprotease. / Inactivation of tumor suppressor genes (TSGs) contributes to the genesis of cancers including esophageal squamous cell carcinoma (ESCC) and nasopharyngeal carcinoma (NPC), two prevalent causes of death in Hong Kong. Apart from genetic abnormalities, epigenetic disruptions including CpG methylation represent another major mechanism for TSG inactivation. Promoter methylation of multiple TSGs was detected in different cancer types, suggesting that it could be utilized as therapeutic target or biomarker for disease diagnosis and prognosis. / TSGs are often located at frequently deleted chromosomal regions and subjected to tumor-specific methylation, making it possible to use an integrative epigenetic and genomic approach combining array comparative genomic hybridization (aCGH) with epigenetic profiling to screen for novel TSGs. Previous aCGH revealed that several loci in 11822.3, 15q14, 15q21.1 and 15q21.3 underwent frequent copy number loss in ESCC cell lines. Loss of heterozygosity (LOH) of these regions was also reported in other cancers, indicating that TSGs might reside within them. The aim of this study was thus to identify the candidate TSGs in these loci and study their anti-tumorigenic roles. In addition, the tumor suppressive function of ADAMTS8, a silenced 11q25 candidate TSG previously identified in our lab via this approach, was also studied. / Li, Jisheng. / Adviser: Qian Tao. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 136-159). / 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.
74

NF-кB targeting by dehydroxymethylepoxyquinomicin (DHMEQ) in nasopharyngeal carcinoma (NPC). / NF-kappa B targeting by dehydroxymethylepoxyquinomicin (DHMEQ) in nasopharyngeal carcinoma (NPC) / NF-KB targeting by dehydroxymethylepoxyquinomicin (DHMEQ) in nasopharyngeal carcinoma (NPC) / 抗癌葯物DHMEQ在鼻咽癌中標靶NF-кB腫瘤治療 / Kang ai yao wu DHMEQ zai bi yan ai zhong biao ba NF-кB zhong liu zhi liao

January 2008 (has links)
Wong, Ho Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 66-77). / Abstracts in English and Chinese. / Acknowledgement --- p.i / List of abbreviations --- p.ii / List of tables and figures --- p.iv / Abstract in English --- p.vi / Abstract in Chinese --- p.viii / Table of content --- p.x / Chapter Chapter 1 --- Literature review / Chapter 1.1 --- Nasopharyngeal carcinoma (NPC) and treatments --- p.1 / Chapter 1.2 --- EBV and NF-kB signaling in NPC / Chapter 1.2.1 --- Role of EBV and NF-kB in NPC --- p.2 / Chapter 1.2.2 --- NF-kB signaling in cancer --- p.4 / Chapter 1.2.3 --- NF-kB activation in NPC --- p.7 / Chapter 1.2.3.1 --- NF-kB activation by LMP1 --- p.8 / Chapter 1.2.3.2 --- NF-kB and LMP2A --- p.10 / Chapter 1.2.3.3 --- NF-kB activation by non-viral factors --- p.10 / Chapter 1.2.4 --- NF-kB target genes in NPC --- p.11 / Chapter 1.3 --- NF-kB targeting / Chapter 1.3.1 --- NF-kB targeting agents --- p.14 / Chapter 1.3.2 --- "DHMEQ, a novel blocker of NF-kB Transactivation" --- p.15 / Chapter Chapter 2 --- Aim of study and Research plan --- p.18 / Chapter Chapter 3 --- Materials and Methods / Chapter 3.1 --- Cell lines and Reagents --- p.20 / Chapter 3.2 --- Cell viability assay --- p.21 / Chapter 3.3 --- Cell apoptosis detection / Chapter 3.3.1 --- PARP cleavage --- p.22 / Chapter 3.3.2 --- DNA fragmentation --- p.22 / Chapter 3.4 --- Cell cycle analysis --- p.22 / Chapter 3.5 --- Transwell migration or Matrigel invasion assay --- p.23 / Chapter 3.6 --- Soft agar colony formation assay --- p.24 / Chapter 3.7 --- Drug treatment for western blotting --- p.25 / Chapter 3.8 --- "Protein extraction and quantification, SDS-PAGE and western blotting" / Chapter 3.8.1 --- Protein extraction and quantification --- p.25 / Chapter 3.8.2 --- SDS-PAGE and western blotting --- p.26 / Chapter 3.9 --- Fractionation --- p.28 / Chapter 3.10 --- NF-kB transcriptional activity assay / Chapter 3.10.1 --- Construction of NF-kB reporter system --- p.29 / Chapter 3.10.2 --- Luciferase assay --- p.29 / Chapter 3.11 --- Statistical Analysis --- p.30 / Chapter Chapter 4 --- Results / Chapter 4.1 --- Anti-tumor activity of DHMEQ in NPC / Chapter 4.1.1 --- Growth inhibition in NPC cell lines --- p.31 / Chapter 4.1.2 --- Apoptotic induction in NPC cell lines --- p.35 / Chapter 4.1.3 --- Cell cycle arrest in NPC cell lines --- p.38 / Chapter 4.1.4 --- Inhibition of migration and invasive behavior of NPC cell lines --- p.38 / Chapter 4.1.5 --- Abrogation of soft agar colony formation ability of NPC cell lines --- p.43 / Chapter 4.2 --- Mechanistic study of DHMEQ in NPC / Chapter 4.2.1 --- Blockade of p65 nuclear translocation --- p.48 / Chapter 4.2.2 --- Attenuation of NF-kB transcriptional activity --- p.48 / Chapter 4.2.3 --- Downregulation of NF-kB target genes --- p.53 / Chapter Chapter 5 --- Discussion --- p.54 / Chapter Chapter 6 --- Summary --- p.60 / Chapter Chapter 7 --- Future Study --- p.63 / Reference List --- p.66 / Appendix / Chapter Appendix 1 --- Construction of NF-kb report plasm id --- p.78 / Chapter Appendix 2 --- Wound healing assay --- p.86 / Chapter Appendix 3 --- Reverse-phase protein Array --- p.88
75

Investigação de sapovírus em amostras de swab nasofaringeano e fezes de crianças hospitalizadas de Goiânia, Goiás / Investigation of sapovirus in nasopharyngeal swab samples and feces of hospitalized children from Goiânia, Goiás

Silva, Thairiny Neres 03 October 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-11-13T10:36:11Z No. of bitstreams: 2 Dissertação - Thairiny Neres Silva - 2017.pdf: 2022674 bytes, checksum: a9ff46169fe46df4f2909e2719e18791 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-11-13T10:36:47Z (GMT) No. of bitstreams: 2 Dissertação - Thairiny Neres Silva - 2017.pdf: 2022674 bytes, checksum: a9ff46169fe46df4f2909e2719e18791 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-13T10:36:47Z (GMT). No. of bitstreams: 2 Dissertação - Thairiny Neres Silva - 2017.pdf: 2022674 bytes, checksum: a9ff46169fe46df4f2909e2719e18791 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-10-03 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Sapoviruses are important agents causing acute gastroenteritis worldwide, and are most often detected in children under five years of age. The present study aimed to evaluate the positivity and viral load index of sapovirus in faecal samples and nasopharyngeal swab of children, in association with the symptoms presented by these children. The study included 102 children hospitalized at the Hospital Materno Infantil, presenting symptoms of gastroenteritis, attended between May 2014 and May 2015, with a sample of faeces and a nasopharyngeal swab sample from each of them. Samples of faeces and nasopharyngeal swabs from all children were submitted to extraction of the genetic material from a commercial kit and screened for sapovirus by RT-qPCR. The viral load was determined by constructing a standard curve from recombinant plasmid. A faecal sample and a nasopharyngeal swab sample were obtained and 47% of the children were positive for sapovirus in at least one of the samples collected, being 10.7% positive only in faecal samples and 28.4% positive only in the samples of nasopharyngeal swab. Regarding viral load, a median of 7.77 x 108 CG / mL was found for stool samples. Regarding the viral load of the nasopharyngeal swab samples, a median 1.54 x 108 CG / mL was observed and a statistically significant result was observed (13/14 p = 0.01), for the samples with viral load above the median obtained in the rainy season. The median viral load of samples from positive children in both clinical specimens was 2.33 x 108 CG / mL in the faeces and 2.67 x 108 CG / mL in the nasopharyngeal swab. Two of these children presented a considerably higher viral load when compared to the others. It is hoped that the data obtained may contribute to a better understanding of the molecular epidemiology of sapoviruses, as well as to the development of better preventive measures, in order to limit the risk of transmission of sapoviruses, especially in a hospital environment. This is the first study to carry out the research and detection of sapovirus in a respiratory tract sample, which could suggest a possible alternative route of viral transmission. / Sapovírus são importantes agentes causadores de gastroenterite aguda no mundo todo, sendo mais frequentemente detectados em crianças menores de cinco anos. O presente estudo teve como objetivo, avaliar o índice de positividade e carga viral de sapovírus em amostras de fezes e swab nasofaringeano de crianças, em associação com os sintomas apresentados por essas crianças. Participaram do estudo 102 crianças hospitalizadas no Hospital Materno Infantil, apresentando sintomas de gastroenteríte, atendidas entre o período de maio de 2014 a maio de 2015, sendo obtidas uma amostra de fezes e uma amostra de swab nasofaringeano de cada uma delas. As amostras de fezes e de swab nasofaringeano de todas as crianças, foram submetidas a extração do material genético a partir de kit comerciale triadas para sapovírus por RT-qPCR. A carga viral foi determinada através da construção de uma curva padrão, a partir de plasmídeo recombinante. Foram obtidas uma amostra de fezes e uma de amostra de swab nasofaringeano sendo 47% das crianças foram positivas para sapovírus em pelo menos uma das amostras coletadas, sendo 10,7% positivas apenas nas amostras de fezes e 28,4% positivas apenas nas amostras de swab nasofaringeano. Em relação a carga viral constatou-se uma mediana 7,77 x 10 8 CG/mL para as amostras de fezes. Em relação a carga viral das amostras de swab nasofaringeano, foi observada uma mediana 1,54 x 10 8 CG/mL e um resultado estatisticamente significativo foi observado (13/14 p= 0,01), para as amostras com carga viral acima da mediana obtidas no período chuvoso. A mediana da carga viral das amostras proveniente das crianças com positividade em ambos espécimes clínicos foi de 2,33 x 10 8 CG/mL nas fezes e de 2,67 x 10 8 CG/mL nos swab nasofaringeano. Duas dessas crianças apresentaram carga viral consideravelmente mais elevada, quando comparada com as demais. Espera-se que os dados obtidos possam contribuir para um melhor entendimento da epidemiologia molecular dos sapovírus, bem como para que melhores medidas preventivas sejam desenvolvidas, a fim de limitar os riscos de transmissão dos sapovírus, especialmente em ambiente hospitalar. Este é o primeiro estudo a realizar a pesquisa e detecção de sapovírus em amostra do trato respiratório, o que poderia sugerir uma possível rota alternativa de transmissão viral.
76

Catching the pneumococcus:studies focusing on carriage, epidemiology and microbiological methods

Lankinen, K. S. (Kari S.) 28 June 2003 (has links)
Abstract The purpose of this study was to develop sensitive and specific laboratory diagnostic methods for the demonstration of pneumococcal surface antigens or pneumococcus-specific antibodies in clinical samples. The work took account of epidemiological aspects of both pneumococcal disease and nasopharyngeal carriage of pneumococcus. We first compared the sensitivity of pneumococcal culture and antigen detection methods in nasopharyngeal samples in a developing country setting and then investigated the possibility of improving the sensitivity of the antigen detection by introducing an enrichment step in the procedure. — Further investigations were designed to determine the validity of pneumolysin-specific immune complex bound antibody assay as a tool for diagnosing pneumococcal ALRI in a developing country setting. Finally, we developed an enzyme immunoassay for the detection of pneumococcal capsular polysaccharide antigens, using type-specific antibodies produced in-house in rabbits through immunisation with an in-house-produced pneumococcal whole cell vaccine. The method was tested in nasopharyngeal and middle ear fluid samples. The first results indicated that antigen detection might be more sensitive than culture in demonstrating pneumococci in URT, particularly in children with prior antimicrobial therapy. Antigen detection is a feasible method for studies on pneumococci in developing countries. For type-specific demonstration of S. pneumoniae, detection of pneumococcal antigen after an enrichment step proved a sensitive method that can be applied for epidemiologic study purposes, e.g., in vaccine trials, in areas without ready access to a good microbiology laboratory. Determination of IC-bound pneumolysin IgG antibodies appears to be a useful method for species-specific diagnosis of pneumococcal infections. The results indicating pneumococcal aetiology in ALRI patients in this study compare well with the best results obtained by the use of lung aspirates. Increasing the number of serial samples improves the sensitivity of the assay, but even two samples provide more positive findings than other methods currently in routine use. Criteria of positivity need to be confirmed in subsequent larger studies with both healthy controls and patients with confirmed pneumococcal disease. It is also important to control the findings in patients with pneumonia of non-pneumococcal origin. The novel enzyme immunoassay was shown to work well with enrichment culture samples, with an almost 100% sensitivity compared with the culture. Middle ear fluid samples were too diluted for the enzyme immunoassay method used, and only 74% sensitivity compared with culture was achieved. Provided that adequate samples can be obtained, the method will be a useful complement to the current laboratory methods used to diagnose pneumococcal disease. With the existence of a broad spectrum of microbiological and immunological methods, it is imperative to seek international consensus for standard methods to demonstrate pneumococcus. Otherwise it is very difficult to compare results from different clinical studies. A WHO Working Group recently proposed a standard method for detecting upper respiratory carriage of pneumococcus, but a lot of work remains to be done in other areas of research on pneumococcal infections.
77

Feasibility of an educational intervention program on managing the nutrition impact symptom cluster in patients with nasopharyngeal carcinoma during radiotherapy

January 2016 (has links)
"Background: Nasopharyngeal carcinoma (NPC) is endemic in southern China. Despite the improvement in radiotherapy (RT) technology, NPC patients still suffer from numerous and simultaneous distressing symptoms. / Aims: The aim of the study was to explore the feasibility of an intervention program (an educational intervention program) in managing the most distressing symptom cluster (nutrition impact symptom cluster) in NPC patients during RT. / Methods: The study was carried out in two parts. Part I consisted of groundwork research (n = 130) using a cross-sectional design to identify the most distressing symptom cluster. An instrument validation was also conducted at this point. Part II covered the development process and pilot testing of an educational intervention program, guided by the Medical Research Council (MRC) framework, to manage the nutrition impact symptom cluster identified in Part I. First, to inform development of the intervention, a systematic review was conducted to evaluate the effectiveness of psychoeducational intervention (PEI), which includes the educational intervention, in managing symptom clusters in patients with generic cancers. Second, a descriptive qualitative study was conducted through face-to-face semi-structured interviews with 25 NPC patients and 16 health professionals, separately, to provide further help in developing the intervention by investigating patients’ self-care experience and current clinical practice in managing the nutrition impact symptom cluster. Third, the feasibility and estimated effectiveness of the educational intervention program was explored in a pilot randomized controlled trial (RCT) (n = 40). Outcome measures, including severity of the nutrition impact symptom cluster, body weight, functional performance and quality of life (QOL), were assessed at baseline, week 3 of RT and at the end of RT. Inferential statistics, such as independent t-test, Chi-square test, Fisher’s exact test and the generalized estimating equation (GEE) model, were used to compare the baseline and various outcome variables between groups. / Results: In Part I, the Chinese version of the MD Anderson Symptom Inventory - Head and Neck Module (MDASI-HN-C) was found to be a reliable and valid instrument. The same dataset then revealed four symptom clusters in NPC patients during RT; the nutrition impact cluster was identified as the most distressing, and was thus chosen as the target outcome of the intervention. In Part II, the systematic review found that PEI, in particular, patient education, was a promising intervention to manage cancer symptom clusters. Then, the findings of the qualitative study further informed and guided the development of an educational intervention program. The pilot RCT found that the conducting the program in a clinical setting was feasible and well received by patients. It also had some favorable effects on managing the nutrition impact symptom cluster, in terms of relieving the cluster itself (Cohen’s d = -0.37), and improving the physical well-being (Cohen’s d = -0.15) and head and neck cancer (HNC) specific QOL (Cohen’s d = -0.05). / Conclusion: The implementation of the educational intervention program appears to be feasible with NPC patients during RT, showing some effect in improving the nutrition impact symptom cluster. A future full-scale study with an adequate sample is warranted." / 研究背景:鼻咽癌在中國南部高發。儘管放療技術在進步,鼻咽癌病人在接受放療期間仍然存在著各種同時出現的症狀困擾。 / 研究目的:本研究旨在測試一個健康教育干預項目在管理鼻咽癌病人放療期間最嚴重的營養相關症狀群的可行性。 / 研究方法:本研究分為兩個部分。第一部分採用橫斷面的研究方法(n = 130),目的是為了找出最嚴重的症狀群,包括檢驗一個量表的信效度。第二部分包括健康教育干預專案的設計和預實驗。首先,研究者做了一個系統評價來評估心理及健康教育干預對管理癌症病人症狀群的效果。然後,研究者又做了一個質性研究,通過與25名鼻咽癌放療病人和16名醫護人員面對面訪談來瞭解目前營養相關症狀群的管理現狀,以便為干預的設計提供進一步線索。最後,研究者做了一個隨機對照試驗的預實驗(n = 40),來評價本研究所設計的健康教育干預專案的可行性。研究指標包括營養相關症狀群的嚴重性、體重、功能水準以及生活品質,並於干預前、放療第3周以及放療結束進行測量。統計推斷方法包括獨立樣本t檢驗、卡方檢驗、Fisher確切概率法和廣義估計方程模型,用以比較組間差異。 / 研究結果:第一部分的研究結果表明,中文版的M. D. Anderson症狀調查表(頭頸)的信效度良好。此外,四個症狀群被發現,其中以營養相關症狀群最為嚴重,因此被選為本研究的干預目標。第二部分,通過系統評價,研究者發現心理及健康教育干預,尤其是健康教育對管理癌症病人的症狀群有一定效果。接著,質性研究的結果進一步提示了健康教育干預項目的必要性,並為該專案的設計提供了具體方案。最後,預實驗表明本研究所設計的健康教育干預專案是可行的並受病人歡迎。該項目在減輕營養相關症狀群(Cohen’s d = -0.37)以及提高與身體(Cohen’s d = -0.15)和頭頸癌相關(Cohen’s d = -0.05)的生活品質上有一定效果。 / 研究結論:本研究所設計的健康教育干預專案是可行的,並對管理鼻咽癌病人放療期間的營養相關症狀群有一定效果。將來需要做一個大規模的研究來驗證該項目的有效性。" / Xiao, Wenli. / Thesis Ph.D. Chinese University of Hong Kong 2016. / Includes bibliographical references (leaves 226-250). / Abstracts also in Chinese. / Title from PDF title page (viewed on 01, February, 2018). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
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Libération extra-cellulaire de microARN et de complexes nucléo-protéiques par les cellules infectées par EBV : rôle des exosomes et d’autres transporteurs / Extra-cellular release of microRNA and nucleoprotein complexes by malignant cells infected by EBV : role of exosomes and other carriers

Gourzones, Claire 03 November 2011 (has links)
En pathologie tumorale, l’étude du micro-environnement tumoral doit prendre en compte différents modes de communication cellulaire : contacts directs entre membranes plasmiques, émission et réception de cytokines et enfin émission et internalisation d’objets biologiques plus complexes comme les microvésicules et les exosomes qui peuvent être assimilés à de véritables organites extra-cellulaires. Le virus d’Epstein-Barr (EBV) participe à l’oncogenèse de plusieurs affections malignes humaines d’origine épithéliale (carcinomes nasopharyngés ou NPC) ou lymphocytaire (lymphomes post-transplantation). Dans ces tumeurs, les cellules malignes qui sont infectées de façon latente par EBV libèrent des exosomes et des microvésicules qui contiennent des protéines et des acides nucléiques d’origine virale. L’étude de ces éléments doit permettre de mieux comprendre les interactions hôte-tumeur et de mettre en évidence de nouveaux biomarqueurs utiles pour le diagnostic précoce et la surveillance de la maladie sous traitement. Le premier objectif de ma thèse consistait à étudier la sécrétion par les cellules malignes d’une famille de microARN viraux appelés miR-BART et leur diffusion dans le sang périphérique chez les sujets porteurs de tumeurs associées à EBV. Pour la première fois j’ai mis en évidence une sécrétion d’exosomes porteurs de miR-BART par les cellules de NPC en culture in vitro. J’ai également montré que les miR-BART, particulièrement miR-BART7, sont détectables dans le plasma de sujets porteurs de NPC. Contrairement à ce qui se passe in vitro les miR-BART plasmatiques ne sont pas transportés par des exosomes. Des données obtenues chez la souris montrent qu’ils peuvent être transportés par des complexes extra-cellulaires que l’on peut précipiter au moyen d’anticorps anti-ago2. Nous cherchons à confirmer ces données sur des échantillons de plasma provenant de patients porteurs de NPC. Ces données pourront guider à l’avenir l’utilisation des miR-BART circulants comme source de biomarqueurs.Le deuxième volet de ma thèse avait pour but d’étudier les modifications du protéome des exosomes induites par une oncoprotéine du virus d’Epstein-Barr appelée LMP1 (latent membrane protein 1). J’ai montré que la LMP1, lorsqu’elle est exprimée dans les cellules lymphocytaires ou épithéliales, infectées ou non par EBV, induit la libération de la protéine PARP1 dans le milieu extra-cellulaire. Cette PARP1 extra-cellulaire n’est pas associée aux exosomes ni aux microvésicules mais à des nano-objets non-vésiculaires contenant notamment des histones et de l’ADN. Nous avons désignés ces objets sous le terme de complexes ADN-protéines extra-cellulaires. Nous ne savons presque rien de la biogenèse de ces complexes ; nous pensons qu’ils ne proviennent pas uniquement de cellules en apoptose. En revanche, des expériences préliminaires suggèrent que la présence de PARP1 dans ces complexes coïncide avec une activation permanente de la PARP1 induite dans les cellules productrices par l’expression de l’oncoprotéine LMP1. Cette hypothèse est en cours de vérification grâce à des expériences menées sur des lignées cellulaires exprimant différentes formes sauvages ou mutées de la LMP1. Ces données sur l’activation de la PARP1 et sur sa sécrétion induite par la LMP1 auront des retombées intéressantes pour notre compréhension des mécanismes d’oncogenèse et d’auto-immunité liés à l’infection par le virus d’Epstein-Barr. / The study of tumoral microenvironment should take into account different modes of intercellular communications: direct contacts between extracellular membranes, secretion and uptake of cytokines and finally emission and uptake of complex biological objects like exosomes and microvesicles.Epstein-Barr virus (EBV) is associated with several human malignancies of epithelial origin (Nasopharyngeal carcinoma or NPC) or of lymphoïd origin (post-transplant lymphoproliferative disorder or PTLD). In these tumors, malignant cells are latently infected by EBV and release exosomes and microvesicles containing viral nucleic acids and proteins. Studying them will enable a better understanding of tumor-host interactions and the discovery of new markers which could be useful for early diagnostic and the follow-up of the disease under treatment.The first aim of this thesis was to study the release by malignant cells of EBV microRNAs belonging to the BART family and their blood diffusion in patients bearing NPC tumors. For the first time, I’ve shown that exosomes released by NPC cells in vitro contain EBV miR-BART microRNAs. Moreover, ebv-miR-BART7 can be detected in the plasma of NPC patients. Unlike what is observed in vitro, circulating BART microRNAs are not carried by exosomes. Recent data from studies in xenografted mice show that they are carried by extra-cellular complexes which can be immunoprecipitated by anti-Ago2 antibodies. We are currently trying to confirm these data in plasma from NPC patients. This work will ease the use of miR-BARTs as potential biomarkers.The second aim was to study the proteome modifications induced by the EBV Latent Membrane Protein 1 protein (LMP1). I’ve shown that LMP1 expression in lymphoid or epithelial cells infected or not by EBV induces the release of PARP1 in the extra-cellular space. This extra-cellular PARP1 is not carried by exosomes or microvesicles but is embedded in non-vesicular nano-objects containing histones and DNA. We have called these objects “DNA-proteins complexes”. We don’t know how they are produced and released by cells. We think that they are not only secreted by apoptotic cells. Recent data show that this release of extra-cellular PARP1 is associated with PARP1 activation by LMP1 oncoprotein expression. We are trying to prove this hypothesis using cell lines expressing wild type or mutated LMP1. The release and the activation of PARP1 induced by LMP1 expression will help to understand the mechanisms of EBV-associated oncogenesis and auto-immunity.
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Functional epigenetics identifies novel KRAB-ZNF tumor suppressors in ESCC, NPC and multiple tumors. / CUHK electronic theses & dissertations collection

January 2010 (has links)
First, expression profiling of ZNFs with CpG islands at 10 clusters of Chr19 was examined in a panel of NPC and ESCC cell lines by semi-quantitative RT-PCR, with adult normal tissues - larynx and esophagus as controls. Several down-regulated genes were identified, and I further focused on 5 candidates: ZNF382, ZNF545, ZFP30, ZNFT1 and ZNFT2. These genes were frequently downregulated in NPC, ESCC, lung, gastric, colon and breast carcinomas. Their promoters were frequently methylated in multiple downregulated cell lines but less in non-tumor cell lines as revealed by methylation-specific PCR (MSP) and bisulfite genomic sequencing (BGS). Their expression could be restored by pharmacologic or genetic demethylation, suggesting that DNA methylation was directly involved in their silencing. The frequent methylation of these genes indicated they could act as potential biomarkers. / In conclusion, several novel candidate TSGs epigenetically silenced in tumor cells were identified in this study. Their downregulation by promoter methylation was tumor-specific, which could be use as epigenetic biomarkers for diagnosis. / More functional studies were done for ZNF382 and ZNF545, I found that ectopic expression of ZNF382 and ZNF545 in tumor cells lacking endogenous expression could inhibit tumor cell clonogenicity, proliferation and induce apoptosis. I found that ZNF382 suppressed tumorigenesis through mediating heterochromatin formation, as ZNF382 was revealed to be co-localized and interacts with heterochromatin protein. For ZNF545, I found that it is a transcriptional repressor. I further showed that ZNF545 was located in the nucleus and sequestered in the nucleolus. ZNF545 could inhibit tumorigenesis at least partially through downregulating the transcription of target genes or regulating nucleolus function such as ribosome biogenesis. / The development of a tumor from a normal cell is a complex and multi-step process. A large number of oncogenes, tumor suppressor genes (TSGs) and signal transduction pathways are involved in this process. Tumor-specific methylation of TSGs in multiple tumors indicated that it could be used as epigenetic biomarker for molecular diagnosis and therapeutics. / The functions of KRAB-containing proteins are critical to cell differentiation, proliferation, apoptosis and neoplastic transformation. A large number of ZNF genes are located in 10 clusters at chromosome 19. Some of the KRAB-ZNF may function as potential TSGs with epigenetic alterations. Thus, I try to identify silenced novel KRAB-ZNF candidate TSGs through screening chromosome 19. / Cheng, yingduan. / Adviser: Tao Qian. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 110-136). / 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Extrathymic T cell receptor gene rearrangement in human alimentary tract

Bas, Anna January 2003 (has links)
<p>T lymphocytes regulate the initiation, duration, and magnitude of adaptive immune responses and function as effector cells in cell mediated immunity. To become immunologically competent they must generate functional antigen receptors. This process takes place in the thymus and requires somatic recombination of T cell receptor (TCR) genes. It is mediated by the endonucleases recombination activating gene-1 (RAG1) and RAG2. Although the thymus regresses at puberty, T cells are present throughout life implying that other tissues must provide the proper milieu for T cell development. This thesis describes extrathymic T cell maturation in man. RAG1, RAG2, and the preTα-chain (pTα), which is exclusively utilized in developing T cells, were used as markers for TCR gene rearrangement. Two new exons (1A and 1B) encoding sequences in the 5’ untranslated region (5’UTR) of mRNA were discovered in the human RAG1 gene. The previously described 5’UTR exon (renamed 1C) was located between the new exons and exon 2, the latter containing the entire coding sequence. We found that small intestinal lymphocytes of the T cell lineage expressed the new exons in three different splice forms. RAG1 mRNA containing the 1C exon was not expressed in small intestinal lymphocytes. In contrast, splice forms containing the 1A exon were not expressed in thymocytes. RAG1 and pTα mRNA expressing lymphocytes were seen both within the epithelium and in lamina propria. Thymocyte-like CD2<sup>+</sup>CD7<sup>+</sup>CD3<sup>-</sup>, CD4<sup>+</sup>CD8<sup>+</sup>, CD1a<sup>+</sup>, and IL7-R+ lymphocytes were identified in the small intestinal mucosa. CD2<sup>+</sup>CD7<sup>+</sup>CD3<sup>-</sup> cells had the highest expression levels of mRNA for RAG1 and pTα, suggesting that the small intestinal mucosa is indeed a site for T cell maturation. Small intestinal T lymphocytes were also shown to kill via the Fas/FasL pathway in a TCR/CD3 independent manner and via the perforin/granzyme pathway in a TCR/CD3 dependent manner. The Fas/FasL-mediated cytotoxicity may reflect an ongoing selection process of extrathymically maturated T cells. </p><p>The nasopharyngeal tonsil is the major inductive site for immune reactions against inhaled antigens. Previous demonstration of RAG1 expression in tonsillar B cells was interpreted as antigen driven receptor revision. The present study confirms the expression of RAG1 in B cells. We also found that RAG1, RAG2, and pTa mRNAs were expressed in lymphocytes of the T cell lineage. A small population of cells with the immature phenotype CD2+CD7+CD3- was demonstrated. This population had the highest expression levels of mRNA for RAG1, RAG2, pTα and terminal deoxynucleotidyl transferase. All four splice-forms of RAG1 mRNA were expressed. RAG1 and pTα mRNA expressing cells were mainly located in the proximity of the surface epithelium and in the outer rim of the follicles. These results suggest that the nasopharyngeal tonsil is a site where extrathymic T cell development and antigen driven TCR revision are occurring in parallel. </p><p>Celiac disease (CD) is a small intestinal enteropathy characterized by permanent intolerance to gluten. Gluten reactive intestinal T cells are central in the pathogenesis and CD can be regarded as a failure to maintain tolerance to this food antigen. Expression of the RAG1 1A/2 splice form was significantly decreased in small intestinal T cell subsets of CD patients suggesting that impaired TCR gene rearrangement could contribute to failure of maintain tolerance in CD. </p><p>Together, these findings show that both small intestinal and nasopharyngeal tonsillar lymphocytes of T cell lineage have the molecular machinery for antigen receptor rearrangement and that thymocyte-like lymphocytes are present in both tissues. Thus these organs are likely sites of T lymphocyte ontogeny as well as for secondary T cell receptor rearrangement in man. </p>

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