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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.
481

Dissecting the molecular responses of Sorghum bicolor to Macrophomina phaseolina infection

Bandara, Y.M. Ananda Yapa January 1900 (has links)
Doctor of Philosophy / Department of Plant Pathology / Christopher R. Little / Charcoal rot, caused by the necrotrophic fungus, Macrophomina phaseolina (Tassi) Goid., is an important disease in sorghum (Sorghum bicolor (L.) Moench). The molecular interactions between sorghum and M. phaseolina are poorly understood. In this study, a large-scale RNA-Seq experiment and four follow-up functional experiments were conducted to understand the molecular basis of charcoal rot resistance and/or susceptibility in sorghum. In the first experiment, stalk mRNA was extracted from charcoal-rot-resistant (SC599) and susceptible (Tx7000) genotypes and subjected to RNA sequencing. Upon M. phaseolina inoculation, 8560 genes were differentially expressed between the two genotypes, out of which 2053 were components of 200 known metabolic pathways. Many of these pathways were significantly up-regulated in the susceptible genotype and are thought to contribute to enhanced pathogen nutrition and virulence, impeded host basal immunity, and reactive oxygen (ROS) and nitrogen species (RNS)-mediated host cell death. The paradoxical hormonal regulation observed in pathogen-inoculated Tx7000 was characterized by strongly upregulated salicylic acid and down-regulated jasmonic acid pathways. These findings provided useful insights into induced host susceptibility in response to this necrotrophic fungus at the whole-genome scale. The second experiment was conducted to investigate the dynamics of host oxidative stress under pathogen infection. Results showed M. phaseolina’s ability to significantly increase the ROS and RNS content of two charcoal-rot-susceptible genotypes, Tx7000 and BTx3042. Over-accumulation of nitric oxide (NO) in stalk tissues in the pathogen-inoculated susceptible genotypes was confirmed using a NO-specific fluorescent probe and confocal microscopy. Significantly increased malondialdehyde content confirmed the enhanced oxidative stress experienced by the susceptible genotypes after pathogen inoculation. These findings suggested the contribution of oxidative stress-associated induced cell death on charcoal rot susceptibility under infection. In the third functional experiment, the behavior of the sorghum antioxidant system after pathogen inoculation was investigated. M. phaseolina significantly increased the glutathione s-transferase (GST), glutathione peroxidase (GPX), glutathione reductase (GR), and peroxidase activities of the susceptible genotypes (Tx7000, BTx3042) but not in the resistant genotypes (SC599, SC35). Increased activities of these enzymes in susceptible genotypes may contribute to reduced oxidative stress thus lowering charcoal rot susceptibility. The fourth functional experiment was designed to quantify induced host-derived cell wall degrading enzymes (CWDEs) using crude enzyme mixtures from stalks. A gel diffusion assay revealed significantly increased pectinesterase activity in pathogen-inoculated Tx7000 and BTx3042 while significantly increased polygalacturonase activity was determined by absorbance. Fluorimetric determination of cell extracts revealed significantly increased cellulose degrading enzyme activity in M. phaseolina-inoculated Tx7000 and BTx3042. These findings revealed the pathogen’s ability to promote charcoal rot susceptibility in grain sorghum through induced host CWDEs. The last functional study was designed to profile the stalk tissue lipidome of Tx7000 and SC599 after M. phaseolina inoculation using automated direct infusion electrospray ionization-triple quadrupole mass spectrometry (ESI-MS/MS). M. phaseolina significantly decreased the phytosterol, phosphatidylserine, and ox-lipid contents in Tx7000 while significantly increasing stigmasterol:sitosterol ratio. Except for ox-lipid content, none of the above was significantly affected in resistant SC599. Results suggested the lethal impacts of M. phaseolina inoculation on plastid- and cell- membrane integrity and the lipid-based signaling capacity of Tx7000. Findings shed light on the host lipid classes that contribute to induced charcoal rot susceptibility in grain sorghum.
482

Anxiety among Adolescents : Measurement, Clinical Characteristics, and Influences of Parenting and Genetics

Olofsdotter, Susanne January 2017 (has links)
Anxiety is the most commonly reported mental health problem among adolescents. Still, many adolescents in need of treatment are not detected and the clinical characteristics and etiological pathways of adolescent anxiety are under-researched topics. This thesis examined the clinical utility of the Swedish versions of the Spence Children’s Anxiety Scale (SCAS) and the clinical characteristics of multiple anxiety disorders among psychiatrically referred adolescents, and the influence of parenting and oxytocin gene (OXT) variants on anxiety among adolescents in the general population.  Studies employed cross-sectional and longitudinal designs and were based on questionnaire, interview, and genotype data. Support for the reliability and validity of both SCAS and SCAS-P was obtained. The overall ability to predict anxiety among referred adolescents ranged from fair to excellent for both scales.  Among adolescents psychiatrically referred for any reason, the prevalence of any anxiety disorder was 46%. Homotypic comorbidity was observed in 43%, and heterotypic comorbidity in 91%. Early adolescent anxiety influenced homotypic anxiety in late adolescence independent of parental rejection and control. The mediating role of parenting was small with indirect effect sizes no larger than one-tenth the size of direct effects, irrespective of the informant on parenting behavior. Significant interaction effects with positive and negative parenting were observed for OXT variants rs4813625 and rs2770378 in relation to social anxiety. The nature of the interactions was in line with the differential susceptibility framework for rs4813625, whereas for rs2770378, results indicated a diathesis–stress type of interaction. The findings suggest that psychiatrically referred adolescents with anxiety disorders are best characterized as a highly complex patient group and call attention to the necessity of structured assessment. For this purpose, this thesis provides evidence for the clinical utility of the SCAS; routine utilization of this questionnaire can improve detection of adolescents in need of anxiety treatment. Findings of this theses further suggest that the influence of positive and negative parenting behaviors on anxiety may be of greater importance among some adolescents than others, depending on individual differences in sensitivity to parenting. The etiology of anxiety among adolescents may therefore involve differential susceptibility effects of the interplay between genes and parenting behaviors.
483

Genetic diversity and population structure of plasmodium falciparum from four epidemiological locations in Malawi

Selemani, George Paul January 2014 (has links)
In malaria-endemic regions, Plasmodium falciparum (P. falciparum) infection is characterized by extensive genetic/antigenic diversity. Describing this diversity provides important information about the local molecular epidemiology of infecting P. falciparum parasites. Intriguingly, one of the major obstacles to the development of an effective malaria vaccine has been the genetic polymorphisms exhibited by P. falciparum genes encoding targets of human immune system. This situation has necessitated the development of polyvalent vaccines with wide antigenic coverage that would increase the likelihood of vaccine efficacy that covers wide geographical areas of malaria endemic countries. Limited reports are available on the population genetic diversity and structure of P. falciparum in Malawi, and this is of particular concern as the country has put in place several interventions to combat the disease. The primary aim of the research project was to determine the genetic diversity and population structure of P. falciparum isolates and comparing complexity from four different epidemiological settings in Malawi using msp-2 gene polymorphisms. Samples were collected from four epidemiological locations in the north, centre and southern regions of Malawi. The diversity and genetic differentiation of P. falciparum populations were analyzed based on the highly polymorphic block 3 msp-2 gene. One hundred and twenty patient samples who presented with signs and symptoms of malaria and who had microscopically confirmed P. falciparum infection were enrolled in the study after they had satisfied the inclusion criteria. Parasite DNA was extracted from the blood spot on to filter paper and analyzed by genotyping the msp-2 gene using allele-specific nested PCR. A total of 28 msp-2 block 3 fragments, defined by the size and the allelic types were detected in the 102 patients. The length variants of the PCR product ranged from 240basepairs (bp) to 450bp for the K1/FC and 410bp to 780bp for the 3D7/IC allelic families. Isolates of the 3D7 alleles were predominant in the population (59 percent), compared to isolates of the K1/ FC27 alleles (41 percent) and for 3D7 and K1 most of the isolates were monoclonal infections. In comparisons between the sites, we observed the highest prevalence of mixed infection in Mwanza (46.7 percent) followed by Dwangwa (23.3 percent) compared to Bolero (16.7 percent) and Mitundu (16.7 percent). The difference in prevalence of mixed infections between Mwanza and the other sites was statistically significant (p=0.041). There was also a non-significant trend towards a higher mean genotype number per isolate in the children aged >5 years compared to those below 5 years of age. These data suggest differences in prevalence rates of mixed infections in different geographical/epidemiological settings in Malawi. Further studies are needed to confirm, with larger sample sizes, the observation of a non-significant trend towards higher multiclonality of infection in older children in malaria endemic areas of Malawi.
484

The Control of Surface Skin Temperature Through Hypnosis and Hypnotic Age Regression

Neuger, Gary Jay 12 1900 (has links)
A total of 60 male and female subjects scoring between 0-5 and 8-12 on the Harvard Group Scale of Hypnotic Susceptibility: Form A underwent hypnosis procedures, hypnosis and age regression procedures to age 10, or were read an article about hypnosis. All subjects then listened to 20 minutes of directed imagery for warming and cooling the hands. Skin temperature was monitored on both index fingers. Dependent measures were the difference between each subject's highest temperature and baseline temperature, the difference between each subject's baseline temperature and lowest temperature, and the latency of change from baseline to highest temperature, and the latency of change from the beginning of cooling imagery to lowest temperature. Results indicated that the age regression group achieved significantly warmer temperatures than the control group and that the age regression group remained significantly warmer than the two other groups during the cooling imagery. Results also indicated that these skin temperature responses generalized to the nondominant hand. The data were interpreted as suggesting that those subjects exposed to the age regression procedures may have been more relaxed than the other groups. Another interpretation suggested the cooling imagery may not have been accessing common or pleasant experiences of the subjects.
485

The Role of the Circardian Clock in the Control of Plant Immunity in Arabidopsis Thaliana

Alhumaydhan, Norah January 2015 (has links)
The circadian clock regulates a wide range of biological processes, allowing plants to be prepared for predictable daily diurnal changes in environmental cues such as light and temperature. Recent studies have suggested that the circadian clock may also control plant immunity. The exact nature of the interaction between the circadian clock and plant pathogens remains unknown. Our focus in this study is on the elucidation of the role of the biological clock in plant immunity against the necrotrophic pathogen to Botrytis cinerea. In order to do this we tested the level of susceptibility to B. cinerea in Arabidopsis thaliana wild type and transgenic plants: toc1, cca1/lhy, cca1/toc1, lhy/toc1, cca1/lhy/toc1, GLK1 OE, GLK2 OE, glk1, glk2, and glk1/glk2. We demonstrated that the time of infection plays a role in susceptibility to B. cinerea. Specifically, we found that plants are more susceptible to infection in the subjective morning. We also found that genetic mutations in core clock components or in GLK genes leads to changes in susceptibility to B. cinerea. Our data suggests that clock genes are not solely responsible for plant immune responses to B. cinerea but rather the ways in which the biological clock system regulates outcome pathways. Furthermore, when we entrain the biological clock by changing the photoperiod (day length) in normal earth conditions LD 24h and SD 24h, we observed that short day plants had higher susceptibility to B. cinerea than long day plants. In addition, when we entrain the biological clock in different photoperiods, the LD 30h photoperiod plants displayed similar responses as those in the SD 24h photoperiod. The data indicates that day length is not responsible for the control of plant immunity; it is the ability of light to entrain the biological clock that is important. Together, the data strongly support the conclusion that the circadian clock plays a role in plant defense regulation.
486

Youth vulnerability and susceptibility to credit card misuse and indebtedness : a cross-country exploration

Awanis, Sandra January 2013 (has links)
Vulnerable consumers are likely to fall victim to negative marketplace outcomes due to the secondary effects of marketing practices. In particular, credit card targeting directed towards young people elicits ethical criticisms because of the perceived vulnerability of the target segment, the targeting efforts that are deemed more predatory than informative, and the stigmatising protectionist policies that limit the youths’ financial freedom. Vulnerable consumers are often overlooked in marketing considerations, leaving it to the public policy to intervene. This thesis aims to show that vulnerability is a marketing problem as much as it is a public policy issue, by highlighting the social effects of unethical marketing directed towards vulnerable consumers. The study depicts how young people, supposedly representing the most educated segment of the population, come to experience vulnerability due to credit card misuse and indebtedness. In addition, the study introduces a new concept and measure of susceptibility to credit card misuse and indebtedness (SCCMI) to investigate the extent to which youths are influenced by credit card temptations, which affect their likelihood to experience negative credit card outcomes. This study examines youth vulnerability and susceptibility to credit card misuse and indebtedness in a cross-country context, as the issue of vulnerability and power imbalance is arguably more pressing in the international market. The sampling involves young (18-25 years) credit card users in Singapore, Malaysia and the UK. These countries represent different degrees of credit card issuance and consumer protection regulations, which affect the youths’ credit card attitude and behaviour. The first study utilises qualitative methodology to examine youth vulnerability to credit card misuse. Baker et al.’s (2005) situational framework of actual consumer vulnerability helps to identify relevant themes pertained to the youths’ experience of credit card misuse and indebtedness. The qualitative study also serves as an exploratory phase to the subsequent quantitative study. The qualitative results enhance the conceptualisation and measurement scale development of SCCMI measure. The study then tested the validity, reliability and parsimony of the SCCMI measure and its proposed antecedent and consequent factors across the Malaysian, Singaporean and UK country samples. Vulnerability and susceptibility assessments in this study yield theoretical, methodological and practical implications. Vulnerability analysis draws upon the internal characteristics and external conditions that both facilitate and impede such vulnerability. Meanwhile, assessment of susceptibility provides an analytical tool to foresee and pre-empt future vulnerability. This study offers methodological contributions in its use of mixed methods, as a qualitative inquiry aids in understanding vulnerability while quantitative inquiry focuses on foreseeing potential vulnerability. A cross-country study analysis is valuable as it sheds light on the differences and similarities of consumer vulnerability and susceptibility across developing and developed countries. The study inform marketers that there are negative social consequences arising from unethical targeting practices, which leads to distrust and scepticism over credit card marketing directed towards youths. However, the youths’ experience of vulnerability also varies across individuals, which indicate that protectionist policies that shield the entire youth population from credit card exposure are not always necessary. Both credit card marketers and policy makers have the capacities to redress and pre-empt vulnerability without sacrificing the youths’ financial welfare and rights to harness the benefits that credit cards have to offer.
487

A victimological investigation of farm attacks with specific reference to farmers’ perceptions of their susceptibility, the consequences of attacks for farmers and the coping strategies applied by them after victimisation

Hornschuh, Veronica 28 July 2008 (has links)
Acts of violence on farms and smallholdings are continuing unabated in spite of the efforts of the government and the agricultural unions to quell attacks on members of the farming community. Although research has been done on various aspects of farm attacks, empirical information regarding farmers’ perceptions of their susceptibility to attacks, the consequences that are suffered and the coping strategies that farmers apply after victimisation, is limited to that contained in the Report of the Committee of Inquiry into Farm Attacks. In order to gain first-hand information with regard to this phenomenon, the researcher interviewed 15 direct victims of attacks on a one-on-one basis. All the attacks occurred in the Mpumalanga Province and the adjoining Nokeng Tsa Taemane region in the Gauteng Province. Based on the analysis and interpretation of the data, it was found that most of the respondents felt unsafe on their farms. In spite of this, they were all taken by surprise by their attackers. While the majority of the respondents believed that their homes were reasonably secure, financial and familial constraints prevented some from improving the guardianship on their farms. Those who had good security systems in their homes, were attacked outside or in the early evening before the systems were activated. The findings also revealed that the immediate reactions of victims of farm attacks do not differ fundamentally from those of other victims of crime. Reactions include surprise, fear of being killed, injured and/or raped and powerlessness. After the attacks they often experienced anger and bitterness. Analysis of the data furthermore indicated that physical injuries ranged from minor to serious injuries that necessitated hospitalisation. Emotional and social harm were also experienced by victims, causing them to be fearful and distrustful of black persons, as the attacks were all black on white. Farm attacks also had negative financial consequences for the victims. Capital that might have been used for other purposes had to be used to pay medical and funeral bills and upgrade security, especially since most victims feared re-victimisation. After the attacks some respondents preferred to relocate. While many of the respondents found it too costly to implement the necessary target hardening measures, avoidance behaviour in the form of alertness was identified as the most effective means of preventing victimisation in the future. Other avoidance tactics included feeding dogs in the afternoon when visibility is still good and sending employees out to establish the reason for the visit of black strangers who arrive on the farm without an appointment. Erroneous perceptions with regard to the motives for attacks and the profile of attackers, as well as complacency about security which often sets in because of the routine nature of farmers’ lifestyle, were identified as the main reasons for farmers’ susceptibility to victimisation. It was also found that the respondents’ coping strategies varied. While some relied on their Christian faith and the support of family and friends, others exerted their inner strength to regain their emotional equilibrium. On the basis of the above findings, recommendations were made regarding further research and measures that might be implemented by both the government and farmers to reduce the number of farm attacks. It was highlighted that factors such as hate speech, socio-economic conditions in rural areas, the acceleration of land reform and education deserve further attention. Farmers must guard against complacency and make informed decisions about security on the farms. As coping strategies vary, it was furthermore stated that victimised farmers need to persevere until they have assimilated the negative experience. / Dissertation (MA)--University of Pretoria, 2008. / Social Work and Criminology / unrestricted
488

Resistencia aos farmacos antimicobacterianos em um hospital terciario : utilidade do metodo de microdiluição em placa com sal de tetrazolium / Susceptibility of M. Tuberculosis to first-line antimycobacterial agents in Brazilian hospital : asessing the utility of the tetrazolium (MTT) microplate assay

Ferrari, Michela De Luca, 1978- 14 August 2018 (has links)
Orientadores: Mariangela Ribeiro Resende, Maria Luiza Moretti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T14:58:52Z (GMT). No. of bitstreams: 1 Ferrari_MichelaDeLuca_M.pdf: 2800534 bytes, checksum: 6c0f0dc17633a5c05f98eaf42e330cb7 (MD5) Previous issue date: 2009 / Resumo: Os objetivos do presente estudo foram estimar a prevalência de resistência do M. tuberculosis aos fármacos de primeira linha entre pacientes com tuberculose diagnosticados no Hospital de Clínicas da Unicamp e avaliar o desempenho do método de microdiluição em placa com [3-(4,5-dimethylthiazol-2-yl)- 2,5diphenyl-tetrazolium bromide] (MTT) comparado ao Bactec MGIT 960®. No período foram notificados 360 casos de tuberculose. Destes 211 casos apresentaram cultura positiva para Mycobacterium sp, sendo incluídos 105 casos, nos quais foi identificado o M. tuberculosis. Dentre estes pacientes a apresentação pulmonar da TB ocorreu em 64,8% e co-infecção pelo HIV em 37,1%. A prevalência de resistência a qualquer fármaco foi de 6,7%; multidrogarresistência (RMP e INH) e resistência a INH e SM foram detectadas em 1%, em 3,8% e em 3,8% dos casos, respectivamente. Todos os isolados foram susceptíveis ao EMB. A resistência primária foi encontrada em quatro casos e resistência adquirida em três. Houve associação entre tratamento prévio e resistência (p=0,0181), as demais variáveis estudadas não foram associadas. Dentre os 119 isolados de M. tuberculosis incluídos para a avaliação do desempenho do MTT, ocorreu concordância de 100% para INH e EMB entre os métodos MTT e Bactec MGIT960®, de 99% para RMP (sensibilidade: 90%), enquanto que para SM houve concordância inferior aquela apresentada pelos outros fármacos (95,2%; sensibilidade: 90,9%). A prevalência de resistência entre os casos novos atendidos no Hospital de Clínicas da Unicamp no período de estudo foi de 3,8% para isoniazida, 1% para rifampicina, 3,8% para etambutol e 1% multidrogarresistente. Resistência a qualquer fármaco foi observada em 6,7% dos casos. O método colorimétrico com MTT apresentou bom desempenho e representa uma alternativa acurada, simples e de reduzidos custos, viável e sustentável para locais e países com limitados recursos. / Abstract: This cross-sectional, hospital-based study conducted between January 2006 and March 2008 sought to estimate the resistance of M. tuberculosis to first-line drugs among patients with tuberculosis confirmed by culture at a Brazilian hospital and evaluate the performance of the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) microplate assay in comparison to the Bactec MGIT 960. During the study period were reported to the surveillance system 360 tuberculosis cases, 211 out of these were confirmed by positive culture for Mycobacterium sp and 105 out of these had M. tuberculosis isolated on culture and were included to the prevalence study. Pulmonary involvement was present in 64.8% of cases and HIV co-infection was found in 37.1%. The prevalence of M. tuberculosis resistance was 6.7%; multidrug-resistance [rifampin (RMP) and isoniazid (INH)] and resistance to INH and streptomycin (SM) were detected in 1%, in 3.8% and in 3.8% of cases, respectively. All isolates were susceptible to ethambutol (EMB). The resistance was primary in four cases and acquired in three cases. Previous treatment was associated with resistance (p=0.0181). Among 119 isolates of M. tuberculosis included to the MMTT performance evaluation, there was 100% observed agreement for INH and EMB between the MTT and Bactec MGIT 960¿ methods. For RMP, the observed agreement was 99% (sensitivity: 90%), and for SM, the level of agreement was lower (95.2%; sensibility 90.9%) than those of the other drugs. The prevalence of M. tuberculosis resistance among the new cases during the study period was 6.7%; multidrug-resistance and resistance to INH and streptomycin (SM) were detected in 1%, in 3.8% and in 3.8% of cases, respectively. The colorimetric method with tetrazolium (MTT) represents an accurate, simple and low cost alternative that is both viable and sustainable for settings with limited resources. / Mestrado / Ciencias Basicas / Mestre em Clinica Medica
489

Influência dos polimorfismos dos genes Mu 1 (GSTM1), Theta 1 (GSTT1), XPD Asp312Asn e XPD Lys751Gln na susceptibilidade ao melanoma cutâneo / Influence of the polymorphisms of genes Mu 1 (GSTM1), Theta 1 (GSTT1), XPD Asp312Asn e XPD Lys751Gln in cutaneous melanoma susceptibility

Rinck Júnior, José Augusto, 1974- 26 August 2018 (has links)
Orientador: Carmen Silvia Passos Lima / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T16:24:35Z (GMT). No. of bitstreams: 1 RinckJunior_JoseAugusto_D.pdf: 4925898 bytes, checksum: cf6e78a6e4ad84c7bbe48d34d75fdae6 (MD5) Previous issue date: 2015 / Resumo: As glutationa S-transferases (GSTs) são enzimas detoxificantes. Os genes GSTM1 e GSTT1 são polimórficos e quando deletados perdem a expressão enzimática. As proteínas codificadas pelos genes XPD são responsáveis pelo reparo de lesões do DNA causadas pela luz solar. Polimorfismos nestes genes também podem codificar proteínas com funções comprometidas, em especial o Lys751Gln e o Asp312Asn do gene XPD. Ainda não é claro o papel dos polimorfismos destes genes no risco de melanoma cutâneo (MC) ou se estão associados com os aspectos clínicopatológicos. Foram incluídos 489 indivíduos (231 pacientes, 258 controles). A genotipagem foi realizada por reação em cadeia da polimerase e digestão enzimática. O risco de MC esteve aumentado em 2,00 (IC 95%: 1,05-3,81, P= 0,03) vezes em portadores do genótipo GSTT1 nulo + Asp/Asn + Asn/Asn do XPD Asp312Asn. O GSTT1 nulo elevou o risco de MC metastático em 3,75 (IC 95%: 1,48-9,44, P= 0,006) vezes e se combinado ao GSTM1 nulo em 7,33 (IC 95%: 2,09-25,68, P= 0,003) vezes. O alelo 312Asn elevou o risco de MC no tronco ou membros em 1,80 (IC 95%: 1,19-2,73, P= 0,005) vezes e do subtipo extensivo superficial ou nodular em 1,80 (IC 95%: 1,14-2,84, P= 0,01) vezes. Os genótipos Asn/Asn + Gln/Gln elevou o risco de MC de níveis I, II ou III de Clark em 2,46 (IC 95%: 1,12-5,37, P= 0,02) vezes. Os genótipos GSTM1 nulo + GSTT1 nulo (HR: 3,18; IC95%: 1,21-8,36, P= 0,01) e o genótipo GSTT1nulo + Gln/Gln (HR: 5,93; IC95%: 1,53-22,91, P= 0,01) estiveram associados a maior risco de morte. Concluímos que os referidos polimorfismos em combinações específicas podem aumentar a susceptibilidade ao MC e influenciar suas características clínicopatológicas e sobrevida / Abstract: The glutathione S-transferases (GST) are detoxifying enzymes; the GSTM1 and GSTT1 genes are polymorphic and when deleted lose enzyme expression. The XPD proteins are responsible for DNA damage repair caused by sunlight. Polymorphisms (SNPs) in XPD genes may also result proteins with impaired function, in particular Lys751Gln and Asp312Asn. However It¿s not entirely clear whether the SNPs of these genes influence the risk of cutaneous melanoma (CM) or are associated with clinic pathological aspects of this disease. In the present study 489 individuals were included (231 patients and 258 controls). Genotyping was performed by polymerase chain reaction and enzyme digestion. The risk of MC was increased 2.00-fold (95% CI: 1.05-3.81, P= 0.03) in carriers of the GSTT1 null combined with Asp/Asn + Asn/Asn genotype of XPD Asp312Asn. The GSTT1 null genotype and GSTT1 null + GSTM1 null genotype increased the risk of metastatic MC by 3.75-fold (95% CI: 1.48-9.44, P= 0.006) and 7.33-fold (95% CI: 2.09-25.68, P= 0.003), respectively. The allele 312Asn increased the risk of MC in the trunk or limbs in 1.80-fold (95% CI: 1.19-2.73, P= 0.005) and superficial spreading or nodular subtype in 1.80-fold (95%: 1.14-2.84, P= 0.01). The combined Asn/Asn + Gln/Gln genotype raised the risk of MC in Clark¿s level I, II or III in 2.46-fold (95% CI: 1.12-5.37, P= 0.02). The genotype GSTM1null + GSTT1 null (HR: 3.18; 95% CI: 1.21-8.36, P= 0.01) and GSTT1 null + Gln/Gln (HR: 5.93; 95% CI: 1.53-22.91, P= 0.01) were predictive of lower overall survival. In conclusion, polymorphisms in specific genes combinations may increase susceptibility to MC and influence their clinic pathological features and survival / Doutorado / Clinica Medica / Doutor em Clínica Médica
490

Anxiety and depression: An empirical investigation of the Diathesis-Stress Model of psychopathology

Hartley, Deborah Jean 01 January 1999 (has links)
No description available.

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