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Estudo das propriedades biomecânicas e histológicas da aorta abdominal de ratos diabéticos e expostos à fumação de cigarro / Study of the biomechanical and histological properties of the abdominal aorta of diabetic rats and exposed to cigarette smokeBarão, Felipe Trajano de Freitas 18 June 2018 (has links)
INTRODUÇÃO: O aneurisma da aorta abdominal (AAA) tem grande importância clínica em função de sua incidência e das complicações que pode acarretar, entretanto sua etiopatogenia não está completamente esclarecida. A associação entre tabagismo e desenvolvimento de AAA tem sido repetidamente confirmada. Apesar de o AAA ter sido inicialmente atribuído à aterosclerose, observou-se associação negativa entre diabetes (um dos principais fatores de risco para aterosclerose) e doença vascular aneurismática. O estudo biomecânico e histológico da parede aórtica pode contribuir para a elucidação da etiopatogenia dos aneurismas. OBJETIVOS: Avaliar as propriedades biomecânicas e histológicas da aorta abdominal de ratos em três situações: exposição à fumaça do cigarro, induzidos ao desenvolvimento do diabetes mellitus e com a associação desses dois fatores. MÉTODOS: Setenta e cinco ratos Wistar foram distribuídos em quatro grupos: controle (GC), tabagista (GT), diabético (GD), diabético e tabagista (GDT). Os ratos dos GT e GDT foram expostos à fumaça de cigarro por 30 minutos ao dia, 5 dias por semana. O diabetes foi induzido por injeção endovenosa de estreptozotocina. Após 16 semanas, os animais foram sacrificados para a coleta da aorta abdominal. Testes de tração uniaxiais destrutivos foram realizados para a obtenção das seguintes propriedades biomecânicas: força, tensão, estresse, deformação e energia de deformação. A análise histológica desses fragmentos consistiu na avaliação das fibras colágenas e elásticas e verificação da deposição de elementos da matriz extracelular na túnica média e avaliação da sua composição. Através da zimografia foi quantificada a atividade da metaloproteinase-2 nos espécimes aórticos obtidos. RESULTADOS: Foram analisados os testes biomecânicos válidos de 52 espécimes, sendo que 11 pertenciam ao GC, 10 ao GD, 16 ao GT e 15 ao GTD. A análise biomecânica dos fragmentos não revelou diferença entre os grupos controle, GD, GT e GDT. A deposição de colágeno também não apresentou diferença estatística significativa entre os grupos estudados. A contagem total de lâminas elásticas foi maior nos ratos diabéticos (GD e GDT) quando comparados aos do GT. Foi observada resposta inflamatória mais intensa, com significância estatística, em todos os grupos estudados quando comparados ao GC. A atividade da MMP-2 apresentou diminuição no GD em relação ao GDT, com significância estatística. CONCLUSÕES: As propriedades biomecânicas da parede da aorta de ratos relacionadas à resistência e elasticidade não apresenta diferença entre o GC e os GD, GT e GDT. As alterações histológicas relacionadas à contagem total e fragmentação das lâminas elásticas, deposição de matriz pericelular e perda/substituição celular na túnica média são significativas na parede da aorta do GD, GT e GDT em relação ao GC. A atividade da MMP-2 na aorta do GD é menor que na aorta do GDT / INTRODUCTION: Abdominal aortic aneurysm (AAA) is of great clinical importance due to its incidence and complications, but its etiopathogenesis is not fully understood. The association between smoking and AAA development has been repeatedly confirmed. Although AAA was initially attributed to atherosclerosis, there was a negative association between diabetes (a major risk factor for atherosclerosis) and aneurysmal vascular disease. The biomechanical and histological study of the aortic wall may contribute to the elucidation of the etiopathogeny of the aneurysms. OBJECTIVES: To evaluate the biomechanical and histological properties of the abdominal aorta of rats in three situations: exposed to cigarette smoke, induced to the development of diabetes mellitus, and the association of these two factors. METHODS: Seventy-Five Wistar rats were divided into four groups: control (CG), smoker (GT), diabetic (GD), diabetic and smoker (GDT. The GT and GDT rats were exposed to cigarette smoke for 30 minutes a day, 5 days a week. Diabetes was induced by intravenous injection of streptozotocin. After sixteen weeks, the animals were sacrificed for collection of the abdominal aorta. Uniaxial destructive tensile tests were performed to obtain the following biomechanical properties: maximal force, failure stress, failure tension, failure strain and failure strain energy. The histological analysis of these fragments consisted in the evaluation of the collagen and elastin and verification of the deposition of elements of the extracellular matrix in the tunica media and evaluation of its composition. The activity of metalloproteinase-2 in the aortic specimens obtained was quantified by zymography. RESULTS: A total of 52 strips were studied (11 from GC, 10 from GD, 16 from GT and 15 from GDT. The biomechanical analysis of the fragments was not different between the control group and the GD, GT and GDT groups. Collagen deposition also did not present a statistically significant difference between the studied groups. The total of elastic fibers was higher in diabetic rats (GD and GDT) when compared to GT. A higher inflammatory response was observed, with statistical significance, in all groups studied when compared to CG. The activity of MMP-2 showed a decrease in GD in relation to GDT, with statistical significance. CONCLUSIONS: The biomechanical properties of the aortic wall of rats related to resistance and elasticity do not present a difference between GC and GD, GT and GDT. Histological changes related to total count and fragmentation of the elastic lamina, pericellular matrix deposition, and cell loss / substitution in the tunica media are significant in the aorta wall of GD, GT and GDT in relation to GC. The activity of MMP-2 in the GD aorta is smaller than in the GDT aorta
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Efeitos do tabagismo sobre os fenótipos renal e cardíaco em camundongos císticos por inativação do gene Pkd1 / Effects of smoking on renal and cardiac phenotypes in cystic mice due to inactivation of the Pkd1 geneSousa, Marciana Veloso de 23 January 2019 (has links)
A doença renal policística autossômica dominante (DRPAD) é uma das doenças hereditárias humanas mais comuns, apresentando uma prevalência de 1:543 a 1:4000 em diferentes populações. Esta enfermidade é essencialmente causada por mutação em um de dois genes: PKD1 (Polycystic Kidney Disease 1) ou PKD2. A maior parte dos casos decorre de mutações em PKD1. O tabagismo foi associado independentemente com progressão da doença renal na DRPAD. Em um estudo recente, contudo, tabagismo não influenciou a sobrevida renal nesta doença. Vários estudos também revelam que a deficiência em PKD1/Pkd1 ou PKD2/Pkd2 se associam a disfunção cardíaca. Para analisar os efeitos potenciais da exposição crônica ao tabagismo sobre os fenótipos renal e cardíaco associados à DRPAD, utilizamos como modelo experimental um animal cístico ortólogo fenotipicamente semelhante à DRPAD humana, o camundongo Pkd1flox/flox:Nestincre. Animais machos foram expostos ao tabagismo da concepção até a idade de 18 semanas. Os níveis séricos de ureia foram mais elevados em camundongos Pkd1flox/flox:Nestincre fumantes (CIF) que em Pkd1flox/flox:Nestincre não fumantes (CI) e em animais Pkd1flox/flox fumantes (NCF) que em Pkd1flox/flox não fumantes (NC). O índice cístico renal foi maior nos animais CIF que CI. A taxa de proliferação de células de revestimento cístico, mas não de apoptose, mostrou-se aumentada em camundongos CIF comparados a CI. As taxas de proliferação e apoptose de células tubulares renais foram mais altas nos rins CI que NC e nos rins CIF que NCF. Observamos, ainda, tais taxas mais elevadas em NCF que NC. Camundongos CIF desenvolveram maior índice de fibrose renal que CI. O mesmo efeito do tabagismo foi detectado em camundongos NCF, porém sua intensidade foi muito menor. As expressões renais de Il1b e Tgfb1 não diferiram significantemente entre os grupos. Os níveis renais de glutationa foram mais baixos em camundongos CIF que CI e em animais NCF que NC. A fração de ejeção do ventrículo esquerdo foi reduzida em camundongos CIF e CI em comparação a NC, mas não foi detectada diferença entre CIF e CI. Parâmetros cardíacos estruturais também se mostraram alterados em animais CIF comparados a CI e NCF. Interessantemente, strain circunferencial e a taxa de strain circunferencial foram menores em camundongos CIF que CI e NCF. A pressão arterial média foi mais baixa em animais CIF que CI hipertensos, atingindo níveis que não diferiram de NC e NCF. A taxa de apoptose em tecido cardíaco foi maior em animais CI que NC, mas não diferiu entre CIF e CI nem entre NCF e NC. A taxa de fibrose cardíaca foi mais elevada em camundongos CIF e CI que NC e NCF. Os grupos não diferiram quanto à sobrevida em 18 semanas, mas o peso corporal foi menor em animais CIF que CI em 16 semanas. Nossos achados indicam que a exposição crônica ao tabagismo desde a concepção agravou os fenótipos renal e cardíaco de camundongos císticos deficientes em Pkd1. Dadas as similaridades entre a DRPAD humana e o modelo animal ortólogo estudado, os efeitos deletérios do tabagismo observados devem provavelmente se aplicar a pacientes com DRPAD / Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common human inherited diseases, with a prevalence of 1:543 to 1:4000 in different populations. This disease is essentially caused by mutation in one of two genes: PKD1 (Polycystic Kidney Disease 1) or PKD2. Most cases result from mutations in PKD1. Smoking has been independently associated with renal disease progression in ADPKD. In a recent study, however, smoking did not influence renal survival in this disease. Several studies also revealed that PKD1/Pkd1 or PKD2/Pkd2 deficiency are associated with cardiac dysfunction. To analyze the potential effects of chronic exposure to smoking on renal and cardiac phenotypes associated with ADPKD, we used an orthologous cystic animal phenotypically similar to human ADPKD as experimental model, the Pkd1flox/flox:Nestincre mouse. Male animals were exposed to smoking from conception to the age of 18 weeks. Serum urea nitrogen was higher in Pkd1flox/flox:Nestincre submitted to smoking (CYS) than in Pkd1flox/flox:Nestincre not submitted to smoking (CY) and in Pkd1flox/flox submitted to smoking (NCS) than in Pkd1flox/flox not submitted to smoking (NC). Renal cystic index was higher in CYS animals than CY. Proliferation rate of cyst-lining cells, but not apoptotic rate, was increased in CYS mice compared to CY. The proliferation and apoptotic rates of renal tubular cells were higher in CY kidneys than NC and in CYS kidneys than NCS. We also observed increase in such rates in NCS compared to NC. CYS mice developed a higher renal fibrosis index than CY animals. Although the same effect of smoking was detected in NCS mice, its intensity was much lower than in cystic animals. Renal expression of Il1b e Tgfb1 did not significantly differ among the groups. Renal levels of glutathione were lower in CYS mice than CY and in NCS animals than NC. Left ventricular ejection fraction was reduced in CYS and CY mice compared to NC, but no difference was detected between CYS and CY. Cardiac structural parameters were also altered in CYS animals in comparison to CY and NCS. Interestingly, circumferential strain and circumferential strain rate were lower in the CYS mice than CY and NCS. MAP was lower in CYS animals than in the hypertensive CY mice, reaching normotensive levels that did not differ from NC and NCS. The apoptotic rate in cardiac tissue was higher in CY animals than NC, but did not differ between CYS and CY and between NCS and NC. The rate of cardiac fibrosis was also higher in CYS and CY mice than in NC and NCS. Survival at 18 weeks did not differ among the groups but body weight was lower in CYS animals than CY at 16 weeks of age. Our findings show that chronic exposure to smoking since conception aggravated the renal and cardiac phenotypes of Pkd1-deficient cystic mice. Given the similarities between human ADPKD and the studied orthologous animal model, the observed deleterious effects of smoking are likely to apply to ADPKD patients
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O papel da imunidade adaptativa (Th17/Treg) na progressão da DPOC em modelo induzido por exposição à fumaça de cigarro / The role of adaptive immunity (Th17/Treg) in COPD progression in a cigarette smoke induced modelIto, Juliana Tiyaki 16 October 2018 (has links)
INTRODUÇÃO: O desequilíbrio entre as respostas imunes pró- e anti-inflamatórias, mediado pela via T helper (Th)17 e T regulatória (Treg), respectivamente, contribui para o desenvolvimento e progressão da doença pulmonar obstrutiva crônica (DPOC). Os modelos experimentais são ferramentas valiosas para esclarecer os mecanismos fisiopatológicos envolvidos na diferenciação dos subtipos celulares presentes nos diferentes estágios da DPOC. OBJETIVO: Realizar uma análise temporal da progressão da inflamação mediada pelas respostas imunológicas em modelo experimental induzido por exposição à fumaça de cigarro, com foco no perfil Th17/Treg. MÉTODOS: Camundongos C57BL/6 machos foram expostos à fumaça de cigarro para indução da DPOC, durante 1, 3 ou 6 meses, e os grupos controle foram mantidos no biotério recebendo ar filtrado nos mesmos tempos. Os animais foram anestesiados e traqueostomizados para avaliação da mecânica do sistema respiratório: Raw (resistência de vias aéreas), Gtis (resistência do tecido pulmonar) e Htis (elastância do tecido pulmonar). Em seguida, foram eutanasiados para remoção dos pulmões para posterior análise morfométrica. O alargamento dos espaços aéreos peribrônquico e distal foi mensurado pelo intercepto linear médio (Lm) e as células T CD4+, T CD8+, Treg, B CD20+ e células positivas para granzima-B, IL-17, IL-10, NF-kB e TNF-alfa foram quantificadas na região peribroncovascular por imuno-histoquímica. Adicionalmente, foi realizada dupla marcação por imunofluorescência para as células Treg e IL-10+ e foi avaliada a expressão gênica de NF-?B e TNF nas células epiteliais brônquicas. RESULTADOS: Este modelo experimental de DPOC induzido por exposição à fumaça de cigarro demonstrou um desequilíbrio entre a resposta imune pró-inflamatória, refletida pelo aumento das células T CD4+, T CD8+, B CD20+, IL-17+, NF-kB+ e TNFalfa+; e a resposta imune anti-inflamatória, representada pela redução de células Treg e IL10+. Esta resposta foi progressiva ao longo do tempo de exposição à fumaça de cigarro e foi associado ao aumento do alargamento dos espaços aéreos desde o primeiro mês de exposição e à piora da função pulmonar a partir do terceiro mês. CONCLUSÃO: Nossos achados apontam que o desequilíbrio Th17/Treg associado à falha na regulação do processo inflamatório, mediado pela deficiência na liberação de IL-10 nos estágios iniciais da DPOC, contribuam para a progressão desta doença iratory mechanics / BACKGROUND: The imbalance between pro- and anti-inflammatory immune responses, mediated by T helper (Th)17 and T regulatory (Treg) profiles, respectively, contributes to chronic obstructive pulmonary disease (COPD) development and progression. Experimental models are valuable tools to clarify the pathophysiological mechanisms involved in the cell subtypes differentiation present in different stages of COPD. AIM: To perform a temporal analysis of inflammation progression mediated by immune responses in a cigarette smoke (CS) induced model, focusing on the Th17/Treg profile. METHODS: C57BL/6 mice were exposed to CS to induce COPD for 1, 3 or 6 months, and the control groups were kept under filtered air conditions at the same time points. Animals were anesthetized and tracheostomized for the respiratory mechanics evaluation: airway resistance (Raw), tissue damping (Gtis) and tissue elastance (Htis). Subsequently, they were euthanized for lungs removal in order to perform morphometric analysis. Airspace enlargement was measured by the mean linear intercept (Lm) around airways and in distal parenchyma, and CD4+ T cells, CD8+ T cells, Treg cells, CD20+ B cells and positive cells for granzima-B, IL-17, IL-10, NF-kB and TNF-alpha were quantified in peribronchovascular areas by immunohistochemistry. Also, double-label immunofluorescence for Treg cells and IL-10+ cells was performed and gene expression of NF-kB and TNF was evaluated in bronchiolar epithelial cells. RESULTS: This experimental model of COPD induced by CS exposure demonstrated an imbalance between pro-inflammatory immune response, reflected by the increase in CD4+ T cells, CD8+ T cells, CD20+ B cells, IL-17+, NF-kB+ and TNF-alpha+ cells; and antiinflammatory immune response, represented by the reduction of Treg cells and IL-10+ cells. This response was progressive throughout CS exposure time and was associated with increased alveolar enlargement from the first month of CS exposure and impaired lung function from the third month. CONCLUSION: Our results suggest that Th17/Treg imbalance associated with a failure in pulmonary inflammatory process regulation, mediated by deficiency in IL-10 release in the early stages of COPD, contribute to this disease progression
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Estudo das propriedades biomecânicas e histológicas da aorta abdominal de ratos diabéticos e expostos à fumação de cigarro / Study of the biomechanical and histological properties of the abdominal aorta of diabetic rats and exposed to cigarette smokeFelipe Trajano de Freitas Barão 18 June 2018 (has links)
INTRODUÇÃO: O aneurisma da aorta abdominal (AAA) tem grande importância clínica em função de sua incidência e das complicações que pode acarretar, entretanto sua etiopatogenia não está completamente esclarecida. A associação entre tabagismo e desenvolvimento de AAA tem sido repetidamente confirmada. Apesar de o AAA ter sido inicialmente atribuído à aterosclerose, observou-se associação negativa entre diabetes (um dos principais fatores de risco para aterosclerose) e doença vascular aneurismática. O estudo biomecânico e histológico da parede aórtica pode contribuir para a elucidação da etiopatogenia dos aneurismas. OBJETIVOS: Avaliar as propriedades biomecânicas e histológicas da aorta abdominal de ratos em três situações: exposição à fumaça do cigarro, induzidos ao desenvolvimento do diabetes mellitus e com a associação desses dois fatores. MÉTODOS: Setenta e cinco ratos Wistar foram distribuídos em quatro grupos: controle (GC), tabagista (GT), diabético (GD), diabético e tabagista (GDT). Os ratos dos GT e GDT foram expostos à fumaça de cigarro por 30 minutos ao dia, 5 dias por semana. O diabetes foi induzido por injeção endovenosa de estreptozotocina. Após 16 semanas, os animais foram sacrificados para a coleta da aorta abdominal. Testes de tração uniaxiais destrutivos foram realizados para a obtenção das seguintes propriedades biomecânicas: força, tensão, estresse, deformação e energia de deformação. A análise histológica desses fragmentos consistiu na avaliação das fibras colágenas e elásticas e verificação da deposição de elementos da matriz extracelular na túnica média e avaliação da sua composição. Através da zimografia foi quantificada a atividade da metaloproteinase-2 nos espécimes aórticos obtidos. RESULTADOS: Foram analisados os testes biomecânicos válidos de 52 espécimes, sendo que 11 pertenciam ao GC, 10 ao GD, 16 ao GT e 15 ao GTD. A análise biomecânica dos fragmentos não revelou diferença entre os grupos controle, GD, GT e GDT. A deposição de colágeno também não apresentou diferença estatística significativa entre os grupos estudados. A contagem total de lâminas elásticas foi maior nos ratos diabéticos (GD e GDT) quando comparados aos do GT. Foi observada resposta inflamatória mais intensa, com significância estatística, em todos os grupos estudados quando comparados ao GC. A atividade da MMP-2 apresentou diminuição no GD em relação ao GDT, com significância estatística. CONCLUSÕES: As propriedades biomecânicas da parede da aorta de ratos relacionadas à resistência e elasticidade não apresenta diferença entre o GC e os GD, GT e GDT. As alterações histológicas relacionadas à contagem total e fragmentação das lâminas elásticas, deposição de matriz pericelular e perda/substituição celular na túnica média são significativas na parede da aorta do GD, GT e GDT em relação ao GC. A atividade da MMP-2 na aorta do GD é menor que na aorta do GDT / INTRODUCTION: Abdominal aortic aneurysm (AAA) is of great clinical importance due to its incidence and complications, but its etiopathogenesis is not fully understood. The association between smoking and AAA development has been repeatedly confirmed. Although AAA was initially attributed to atherosclerosis, there was a negative association between diabetes (a major risk factor for atherosclerosis) and aneurysmal vascular disease. The biomechanical and histological study of the aortic wall may contribute to the elucidation of the etiopathogeny of the aneurysms. OBJECTIVES: To evaluate the biomechanical and histological properties of the abdominal aorta of rats in three situations: exposed to cigarette smoke, induced to the development of diabetes mellitus, and the association of these two factors. METHODS: Seventy-Five Wistar rats were divided into four groups: control (CG), smoker (GT), diabetic (GD), diabetic and smoker (GDT. The GT and GDT rats were exposed to cigarette smoke for 30 minutes a day, 5 days a week. Diabetes was induced by intravenous injection of streptozotocin. After sixteen weeks, the animals were sacrificed for collection of the abdominal aorta. Uniaxial destructive tensile tests were performed to obtain the following biomechanical properties: maximal force, failure stress, failure tension, failure strain and failure strain energy. The histological analysis of these fragments consisted in the evaluation of the collagen and elastin and verification of the deposition of elements of the extracellular matrix in the tunica media and evaluation of its composition. The activity of metalloproteinase-2 in the aortic specimens obtained was quantified by zymography. RESULTS: A total of 52 strips were studied (11 from GC, 10 from GD, 16 from GT and 15 from GDT. The biomechanical analysis of the fragments was not different between the control group and the GD, GT and GDT groups. Collagen deposition also did not present a statistically significant difference between the studied groups. The total of elastic fibers was higher in diabetic rats (GD and GDT) when compared to GT. A higher inflammatory response was observed, with statistical significance, in all groups studied when compared to CG. The activity of MMP-2 showed a decrease in GD in relation to GDT, with statistical significance. CONCLUSIONS: The biomechanical properties of the aortic wall of rats related to resistance and elasticity do not present a difference between GC and GD, GT and GDT. Histological changes related to total count and fragmentation of the elastic lamina, pericellular matrix deposition, and cell loss / substitution in the tunica media are significant in the aorta wall of GD, GT and GDT in relation to GC. The activity of MMP-2 in the GD aorta is smaller than in the GDT aorta
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Regulation and Function of Neuronal Nicotinic Acetylcholine Receptors in Lung Cancer: A DissertationImprogo, Ma. Reina D. 10 August 2011 (has links)
Lung cancer is the leading cause of cancer-related mortality worldwide. The main risk factor associated with lung cancer is cigarette smoking. Research through the years suggests that nicotine in cigarettes promotes lung cancer by activating signaling pathways that lead to cell proliferation, cell survival, angiogenesis, and metastasis. Nicotine’s cellular actions are mediated by its cognate receptors, nicotinic acetylcholine receptors (nAChRs). Here, I describe the expression levels of all known human nAChR subunit genes in both normal and lung cancer cells. Of note, the genes encoding the α5, α3, and β4 subunits (CHRNA5/A3/B4) are over-expressed in small cell lung carcinoma (SCLC), the most aggressive form of lung cancer. This over-expression is regulated by ASCL1, a transcription factor important in normal lung development and lung carcinogenesis. The CHRNA5/A3/B4 locus has recently been the focus of a series of genetic studies showing that polymorphisms in this region confer risk for both nicotine dependence and lung cancer. I show that CHRNA5/A3/B4 depletion results in decreased SCLC cell viability. Furthermore, while nicotine promotes SCLC cell viability and tumor growth, blockade of α3β4 nAChRs inhibits SCLC cell viability. These results suggest that increased expression and function of nAChRs, specifically the α3β4α5 subtype, potentiate the effects of nicotine in SCLC. This dual hit from the carcinogens in tobacco and the cancer-promoting effects of nicotine, may provide a possible mechanism for the increased aggressiveness of SCLC. In addition, nAChRs can be activated by the endogenous ligand, acetylcholine, which acts as an autocrine/paracrine growth factor in SCLC. Increased function of α3β4α5 nAChRs in SCLC could also potentiate acetylcholine’s mitogenic effects. This mechanism, combined with other known autocrine/paracrine growth loops in SCLC, may help explain the ineffectiveness of available therapies against SCLC. In an effort to add to the current arsenal against SCLC, I screened a 1280-compund library using a bioluminescence-based viability assay I developed for high-throughput applications. Primary screening, followed by secondary and tertiary verification, indicate that pharmacologically active compounds targeting neuroendocrine markers inhibit SCLC cell viability.
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Developing Three New Pathophysiologically Based Measures of Nicotine Dependence: A DissertationUrsprung, W. W. Sanouri A. 29 January 2014 (has links)
BACKGROUND: Of the 22 known measures of nicotine dependence (ND), none capture the overall disease severity of physical dependence alone. Instead, they capture constructs related to dependence, such as perceived risk, psychological addiction, smoker motivations, or smoking related behaviors, but none of the measures include only physical withdrawal symptoms to capture physical dependence on nicotine.
AIM: To develop a range of nicotine dependence measures that capture physical dependence on nicotine.
METHODS: The final measures were developed in a cross-sectional study conducted in three phases: 1) candidate item development through literature review and cognitive interviews, 2) developing and pre-testing the survey, and 3) survey administration and psychometric evaluation to validate three distinct measures. The final survey was conducted at four health clinics and three high schools. Psychometric tests used to select the final measure items included inter-item correlations, sensitivity analyses done by subgroup, item-total correlations, convergent validity tests, and confirmatory factor analysis. The final measures were evaluated using confirmatory factor analysis (CFA), internal reliability, total score distributions, and convergent validity correlations. Relative validity analyses were also conducted using a ratio of F-Statistics to compare the ability of each new measure to differentiate dependent smokers as compared previous measures.
RESULTS: The final sample included 275 smokers ranging from 14 to 76 years old (mean=30.9, SD=16.2), who smoked an average of 11.5 cigarettes per day (range=0-50, SD=9.4). The sample was 86.5% white and 57.5% male. The three new measures developed included: 1) the 4-item Withdrawal-Induced Craving Scale (WICS) used to capture severity of craving, the most common physical withdrawal symptom; 2) the 12- item Nicotine Withdrawal Symptom Checklist (NWSC), which measures both overall disease severity and the severity of a comprehensive list of individual physical withdrawal symptoms including withdrawal-induced craving, anger, anxiety, depression, headache, insomnia, loss of focus, restlessness, and stress; and 3) the 6-item brief NWSC (NWSC-b), a short measure which only captures overall disease severity. All of the new measures exhibited a unidimensional factor structure loading highly on a single factor (thought to be physical dependence). They also correlated highly (over 0.6) and significantly (p<0.001) to a battery of convergent validity indices including four widely used nicotine dependence measures: Hooked on Nicotine Checklist (HONC), the Autonomy Over Tobacco Scale (AUTOS), the Fagerström Test for Nicotine Dependence (FTND), and self-rated addiction.
CONCLUSION: The WICS, NWSC, and NWSC-b provide three distinct validated tools that can be used by researchers, clinicians, and educators to track the progression of physical dependence on nicotine across a range of smoking behaviors and histories.
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The Role of VTA Gabaergic Nicotinic Acetylcholine Receptors Containing the α4 Subunit in Nicotine Dependence: A DissertationNgolab, Jennifer 06 October 2015 (has links)
Nicotine dependence is hypothesized to be due to neuroadaptations that ultimately drive compulsive nicotine use. The studies in this thesis aim to understand how the “upregulation” of nicotinic acetylcholine receptors (nAChRs) caused by chronic exposure to nicotine contributes to nicotine reward and nicotine withdrawal. Previous studies have shown that chronic nicotine induces upregulation of nAChRs containing the α4 subunit (α4* nAChR) within the Ventral Tegmental Area (VTA), a brain region critical for the rewarding properties of all illicit drugs. Curiously, α4* nAChR upregulation occurs specifically in the inhibitory GABAergic neuronal subpopulation of the VTA. To determine if increased expression and activation of α4* nAChRs in VTA GABAergic neurons contributes to nicotine dependence behaviors, I devised a viral-mediated, Creregulated gene expression system that selectively expressed α4 nAChR subunits containing a “gain-of-function” point mutation (a leucine mutated to a serine residue at the TM2 9´ position: Leu9´Ser) in VTA GABAergic neurons of adult mice. Sub-reward doses of nicotine were sufficient to activate VTA GABAergic neurons in mice expressing Leu9´Ser α4 nAChR subunits in VTA GABAergic neurons (Gad2VTA: Leu9´Ser mice) and exhibited acute hypolocomotion upon initial injection of low doses of nicotine that developed tolerance with subsequent nicotine exposures compared to control animals. In the conditioned place preference procedure, nicotine was sufficient to condition a significant place preference in Gad2VTA: Leu9´Ser mice at low nicotine doses that failed to condition control animals. I conclude from these data that upregulating α4* nAChRs on VTA GABAergic neurons increases sensitivity to nicotine reward. In a separate study testing the hypothesis that overexpression of Leu9´Ser α4* nAChRs in VTA GABAergic neurons disrupts baseline behavior and promotes anxiety-like behaviors, I found that overexpressing Leu9´Ser α4* nAChRs in VTA GABAergic neurons had a minimal effect on unconditioned anxiety-like behaviors. Drug naïve Gad2VTA: Leu9´Ser and control mice failed to exhibit any behavioral differences in the open-field, marble burying test and elevated plus maze compared to control.
Together, these data indicate that overexpression of the “gain-of-function” α4* nAChRs in VTA GABAergic neurons contributes to reward sensitivity without increasing susceptibility to nicotine withdrawal symptoms. My data indicates that nAChRs expressed in VTA GABAergic neurons may be a suitable target for the development of better smoking cessation aids.
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Desenvolvimento e avaliação de uma intervenção para tabagismo mediada por internetGomide, Henrique Pinto 10 February 2014 (has links)
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Previous issue date: 2014-02-10 / Intervenções para tabagismo mediadas por internet disponíveis em língua portuguesa não cobrem
todos os conteúdos das diretrizes de tratamento do tabagismo. Não existem intervenções
de código-aberto na internet, isto é, que divulgam todo o código-fonte para sua adaptação e replicação
para outros contextos e populações. O objetivo do estudo foi descrever uma metologia de
desenvolvimento e avaliar a intervenção para tabagismo mediada por internet de código-aberto
- “Viva sem Tabaco”. O desenvolvimento aconteceu nas seguintes etapas:(1) desenvolvimento
do protótipo, (2) realização de um grupo focal fumantes e correção do protótipo e (3) avaliação
da cobertura, precisão e interatividade do conteúdo com base nos 12 componentes das diretrizes
de tratamento para tabagismo, e (4) revisão do conteúdo. Com os resultados do grupo focal
e na revisão teórica das diretrizes, o protótipo foi desenvolvido e corrigido. Após as correções,
o protótipo foi avaliado pelos especialistas e corrigido. O conteúdo da intervenção foi avaliado
por dois pesquisadores de forma independente, 9 dos 12 tópicos apresentaram cobertura considerada
adequada e 3 com cobertura mínima. Quanto à precisão, 8 tópicos foram avaliados como
corretos e 4 como maior parte correto. Dois dos 12 tópicos apresentaram interatividade. Após
a avaliação, a intervenção foi corrigida. A versão final da intervenção desenvolvida apresentou
convergência com as diretrizes de tratamento. Estudos devem ser conduzidos para avaliar a
eficácia da intervenção. / Web-assisted tobacco interventions (WATI) in Portuguese do not cover the standard guidelines
for smoking treament and lack content quality. Current web-assisted tobacco interventions are
not open-source, which reduce the development speed in developing countries. The objective
of this study was to describe a development methodology of a open-source WATI and evaluate
its quality. The development comprised the following stages: (1) prototype development, (2)
assessment of the prototype using focus groups, and (3) content coverage, accuracy and interactivity
evaluation using as reference the guideline “Treating tobacco use and depedence - 2008
update”, and (4) final review. Based on the data from focus groups and content review, the
initial prototype was redesigned. The content evaluation, performed independently by two specialists,
showed that 9 of 12 components were well covered and 3 minimally covered. Eight of 12
components were classified as correct and 4 as mostly correct. Just two topics were considered
interactive. Based on the evaluation, a final review was conducted in the intervention content.
The developed intervention was compliant with tobacco treatment guidelines, providing an evidence
based guide for smokers who seek help over the internet. Future studies should address
the clinical efficacy of the developed intervention.
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Implementation and Evaluation of a School-Based Anti-Tobacco Program in Mauritius: A Pilot Study to Assess the Usefulness and Reliability of a Tobacco Use Prevention Education InstrumentHussenbocus, Shariah 14 December 2018 (has links)
Tobacco use among Mauritian adolescents has increased steadily since 2008. Currently, Mauritius has not implemented any school-based anti-tobacco program and there is no instrument to assess the effectiveness of existing anti-tobacco school policies. Since the first cigarette can rapidly lead to nicotine dependence, targeted interventions must be assessed before established patterns of smoking appear. This study evaluated a tobacco use prevention education instrument to determine the effectiveness of a school-based anti-tobacco program. 26 male students completed a survey before and after receiving anti-tobacco lessons. Smoking initiation age could not predict likelihood of tobacco addiction (r(12)=0.320, p=0.311). However, after receiving the anti-tobacco lessons, participants were less likely to believe that youth who smoke have more friends (p < 0.001) and were more knowledgeable about tobacco’s dangers (t(25)=3.94, p=0.001). This indicated that, with a few changes, the instrument can be used to assess the implementation of a school-based anti-tobacco program in Mauritius.
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Avaliação do efeito de polimorfismos genéticos com a dependência à nicotina / Evaluation of genetic polymorphisms with nicotine dependenceTomaz, Paulo Roberto Xavier 14 March 2016 (has links)
Introdução: A identificação de variantes genéticas que predispõem a maior susceptibilidade à dependência à nicotina pode ser importante para a prevenção e o tratamento do tabagismo. No contexto de medicina personalizada, os principais objetivos do presente estudo foram avaliar se polimorfismos nos genes CHRNA2, CHRNA3, CHRNA5 e CHRNB3 estão associados com o nível de dependência em indivíduos fumantes e com o resultado do tratamento antitabágico. Métodos: Estudo de coorte com 1049 pacientes fumantes que receberam tratamento farmacológico (vareniclina, vareniclina e bupropiona, bupropiona e/ou terapia de reposição nicotínica). O sucesso na cessação tabágica foi considerado para os pacientes que completaram 6 meses de abstinência contínua. O teste de Fagerström para a dependência à nicotina (FTND) e o escore de consumo situacional Issa foram utilizados para avaliar a dependência à nicotina. A escala de conforto PAF foi utilizada para avaliar o conforto do paciente durante o tratamento. Os polimorfismos CHRNA2 rs2472553, CHRNA3 rs1051730, CHRNA5 rs16969968, CHRNA5 rs2036527 e CHRNB3 rs6474413 foram genotipados pela análise da curva de melting. Resultados: As mulheres portadoras dos genótipos GA e AA para os polimorfismos CHRNA5 rs16969968 e rs2036527 obtiveram maior taxa de sucesso no tratamento antitabagismo: 44,0% e 56,3% (rs16969968), 41,5% e 56,5% (rs2036527), respectivamente; em comparação com as mulheres portadoras do genótipo GG: 35,7% (rs16969968) e 34,8% (rs2036527), (P=0,03; n=389; P=0,01; n=391). Os genótipos GA ou AA para os rs16969968 e rs2036527 foram associados com maior OR para o sucesso em mulheres (OR=1,63; IC 95%=1,04-2,54; P=0,03 e OR=1,59; IC 95%=1,02-2,48; P=0,04; respectivamente), em um modelo multivariado. Não foi encontrada associação dos polimorfismos no gene CHRNA5 com o escore de FTND. Para os polimorfismos CHRNA2 rs2472553, CHRNA3 rs1051730 e CHRNB3 rs6474413 não foram encontradas associações significativas com os fenótipos estudados. Conclusão: Os polimorfismos rs16969968 e rs2036527 no gene CHRNA5 foram associados com maior taxa de sucesso no tratamento antitabagismo em mulheres. Estes resultados podem contribuir com avanços na terapêutica baseada em medicina personalizada / Background: The identification of genetic variants that predispose increased susceptibility to nicotine dependence becomes increasingly important for the prevention and smoking treatment. In the context of personalized medicine, the main aims of this study were to evaluate whether the CHRNA2, CHRNA3, CHRNA5 and CHRNB3 polymorphisms are associated with the level of dependence in smokers and the result of smoking treatment. Methods: This cohort study enrolled 1049 smoking patients who received pharmacological treatment (varenicline, varenicline plus bupropion, bupropion plus/or nicotine replacement therapy). Smoking cessation success was considered for patients who completed 6 months of continuous abstinence. Fagerström test for nicotine dependence (FTND) and Issa situational smoking scores were analyzed for nicotine dependence. PAF comfort scale was used to evaluate the comfort of the patient during treatment. The CHRNA2 rs2472553, CHRNA3 rs1051730, CHRNA5 rs16969968 and rs2036527 and CHRNB3 rs6474413 polymorphisms were genotyped by high resolution melting analysis. Results: Females with GA and AA genotypes for CHRNA5 rs16969968 and rs2036527polymorphisms had higher success rate in smoking cessation treatment: 44.0% and 56.3% (rs16969968), 41.5% and 56.5% (rs2036527), respectively; compared with carriers of the GG genotypes: 35.7% (rs16969968), 34.8% (rs2036527), (P=0.03, n=389; P=0.01, n=391). The GA or AA genotypes to the rs16969968 and rs2036527 were associated with higher odds ratio for success in women (OR=1.63; 95%CI=1.04 to 2.54; P=0.03 and OR=1.59, 95%CI=1.02 to 2.48; P=0.04; respectively), in a multivariate model. We found no association of these polymorphisms with FTND score for nicotine dependence. For the CHRNA2 rs2472553, CHRNA3 rs1051730 and CHRNB3 rs6474413 polymorphisms no significant associations were found with phenotypes studied. Conclusion: The CHRNA5 rs16969968 and rs2036527 were associated with higher success rate in the smoking cessation treatment in women. These results can contribute to major advances in personalized medicine based therapy
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