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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.
141

Bloqueio do sistema renina-angiotensina atenua lesões em órgãos-alvo em modelo de diabetes mellitus tipo 2 e hipercolesterolemia induzidos por dieta / Blockade of renin-angiotensin system attenuates target-organ lesions in a model of type 2 diabetes mellitus and hypercholesterolemia induced by diet

Helfenstein, Tatiana [UNIFESP] January 2009 (has links) (PDF)
Submitted by Diogo Misoguti (diogo.misoguti@gmail.com) on 2016-06-29T12:59:34Z No. of bitstreams: 1 cp118956.pdf: 11152798 bytes, checksum: 413c607598471e1abd0db7c49883c8ac (MD5) / Approved for entry into archive by Diogo Misoguti (diogo.misoguti@gmail.com) on 2016-06-29T13:00:23Z (GMT) No. of bitstreams: 1 cp118956.pdf: 11152798 bytes, checksum: 413c607598471e1abd0db7c49883c8ac (MD5) / Made available in DSpace on 2016-06-29T13:00:23Z (GMT). No. of bitstreams: 1 cp118956.pdf: 11152798 bytes, checksum: 413c607598471e1abd0db7c49883c8ac (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Com o crescente aumento da prevalência mundial de diabetes mellitus, tem-se buscado modelos experimentais para melhor compreensão de sua fisiopatologia e tratamento que atendam de maneira mais adequada à preservação de células beta, proteção de órgãos-alvo e atenuação da aterosclerose. Objetivos: Desenvolver modelo experimental de diabetes mellitus tipo 2 induzido por meio de dieta, e utilizá-lo para examinar os efeitos de um inibidor da enzima conversora de angiotensina (IECA) e de um bloqueador do receptor de angiotensina (BRA) na proteção de órgãos-alvo. Métodos: Coelhos machos Nova Zelândia (n=49) receberam dieta acrescida de banha (10%), sacarose (40%) durante todo o protocolo do estudo além de colesterol (0,5% nos três primeiros meses e 0,1% nos meses subseqüentes). Os animais receberam aleatoriamente: apenas a dieta sem fármacos (G1), olmesartana 5 mg (G2), quinapril 30 mg (G3), ou a combinação de ambos (G4), acrescidos à mesma dieta por seis meses. Foram analisados lípides, frutosamina, glicose e insulina em jejum com cálculo dos índices para resistência à insulina e função de células beta pancreáticas. Foram ainda examinadas as áreas sob as curvas de insulina e glicose, após infusão de glicose intraperitoneal. Angiofluoresceinografias e análises histopatológicas avaliaram lesões em órgãos-alvo. Resultados: Os coelhos ganharam peso, e houve aumento dos níveis de glicose, colesterol total, LDL-C e triglicérides e redução do HDL-C (p <0,05 vs. basal). A frutosamina e o HOMA-IR se elevaram, enquanto houve redução do HOMA-β (p <0,05 vs. basal). Sinais precoces de retinopatia diabética foram observados a partir do terceiro mês, progredindo até o final do experimento (p<0,0005). Lesões ateroscleróticas em aorta, esteatofibrose hepática e infiltrado glomerular de macrófagos constituíram os principais achados histomorfológicos. O bloqueio do sistema renina-angiotensina modificou favoravelmente a glicemia e o HOMA-β (p<0,05) e houve atenuação do número e grau dos microaneurismas pelo tratamento com BRA isoladamente ou combinado com IECA (p<0,05 vs. G1). Conclusões: Nosso modelo reproduziu várias características glucometabólicas do diabetes mellitus tipo 2 humanóide, incluindo déficit de secreção e resistência à insulina. O bloqueio do sistema renina-angiotensina atenuou algumas alterações bioquímicas e as lesões microvasculares em retina. / With the increasing prevalence of diabetes mellitus worldwide, new experimental models are required to better understand the pathophysiology of this disease and to offer therapeutic options that can preserve pancreatic beta-cells, protect target organs and attenuate atherosclerosis. Objective: The aims of this study were to develop an experimental model of type 2 diabetes mellitus induced by diet and assess on this model the effects of an angiotensin-converting enzyme inhibitor (ACEI) and an antagonist of the angiotensin II type1 receptor (AT1R) on target organ protection. Methods: New Zealand male white rabbits (n=49) were fed high-fat/high-sucrose (10/40%) during the study protocol and cholesterol-enriched diet (0.5% in the first three months followed by 0.1% until the end of the study). These animals were randomized to receive: diet alone (G1), olmesartan 5 mg (G2), quinapril 30mg (G3), or combination of both drugs (G4), added to the same diet for six months. Fasting lipids, fructosamine, glucose and insulin, with calculation of insulin resistance and beta-cell function indexes were evaluated. The areas under the curves for glucose and insulin were obtained after intraperitoneal glucose bolus injection. Fluorescein angiography and histopathological analyses were performed to assess target-organs lesions. Results: The animals gained weight, and there were increases in blood glucose, total cholesterol, LDL-C and triglycerides, and decrease in HDL-C (p<0.05 vs. baseline). Fructosamine levels and the homeostasis model assessment of insulin resistance (HOMA-IR) were increased, while there was a reduction in the HOMA-β (p<0.05 vs. baseline). Early clinical features of diabetic retinopathy were seen since the third month, progressing up to the end of the experiment (p<0.0005). Aortic atherosclerosis, hepatic steatofibrosis and glomerular macrophage infiltration were the main histomorphologic findings of this study. The renin-angiotensin system (RAS) blockade favorably modified blood glucose and the HOMA- β (p<0.05) and promoted attenuation of the number and grade of microaneurysms in retina in the group of animals receiving AT1R antagonist or combined therapy with the ACEI (p<0.05 vs. G1). Conclusion: Our model reproduced several glucometabolic characteristics of humanoid type 2 diabetes, including decreased insulin secretion and insulin resistance. The RAS blockade attenuated some biochemical abnormalities and the diabetic retinopathy. / FAPESP: 07/51058-8
142

Adolescentes em situação de acolhimento institucional prolongado : análise do processo de desligamento

Benetti, Daniella Simões 14 December 2012 (has links)
Made available in DSpace on 2016-06-02T19:46:20Z (GMT). No. of bitstreams: 1 4811.pdf: 907758 bytes, checksum: 8839b04b7f1af2b8827dda89f65c7929 (MD5) Previous issue date: 2012-12-14 / The host institution is one of the lines of political action to guarantee the rights of children and adolescents, whose character is provisional and exceptional form of transition to reintegration and family or for integration in a foster family. Usually occurs when families are considered unable to provide child care, or when they have behaviors that put at risk the full development of children. Both the removal of the child or adolescent from family and his dismissal of the institution are made by the Government, however, there is a lack of effective public policies and scientific research data that cover the issue of institutional shutdown, more specifically. The present study aimed to: a) describe the process of institutional shutdown according to the opinion of adolescents who lived in a situation of institutional care for an extended period and the leaders; b) describe the operation of a host institution. This was a qualitative, exploratory. The study included two leaders of the two institutions reception and six individuals who remained in a state of Reception beyond the time allowed by law, and who completed two years of majority, including motive, which led to the shutdown. The instruments used for data collection were: Interview Script 1) The characteristics of the host institution and Interview Script 2) Shutdown Institutional, both were applied with the leaders of institutions and even Home, Interview Script 3) The Consequences Off the Institutional conducted with former accepted. The questions of the interview scripts were submitted before the application, the judges pointed suggestions to better understand the context. The application of the interviews took place at different times and places previously chosen by the participants. By means of the instruments were performed quantitative analyzes, obtained from the defined categories, with the main parameter to content analysis. The results indicated that in some respects the institutions surveyed described themselves differently, therefore, had different types of conduct with regard to the implementation of some of its functions, humanization of the shutdown process, preparation gradual for that time, maintenance of family ties, family support for restructuring, encouraging interaction with other families, participation in the services offered by the local community. Other aspects described by the Institutional leaders have been characterized equally and refer to similar residential maintenance of emotional bonds between siblings, attendance at small groups, among others. Most adolescents showed that the shutdown was a moment Institutional permeated by feelings of sadness, fear, insecurity, memories, and the individual is ready or not to experience this moment and its consequences were related to the difficulty in getting a job, live alone, keep themselves financially. It is concluded that there is need for specific policies that cover the issue of Institutional shutdown, to support the teen financially, emotionally, socially, before, during and after this procedure. Still, training for all social actors involved in institutional care situation for better care and understanding of the context. / O acolhimento institucional é uma das linhas de ação política da garantia dos direitos da criança e do adolescente, cujo caráter é provisório e excepcional; forma de transição para reintegração familiar e ou para integração em família substituta. Normalmente ocorre quando as famílias são consideradas sem condições de dar assistência aos filhos, ou seja, quando apresentam comportamentos que colocam em risco o desenvolvimento pleno dos filhos. Tanto o afastamento da criança ou adolescente do convívio familiar quanto o seu desligamento da instituição são realizados pelo Poder Público, porém, observa-se a inexistência de políticas públicas eficazes, bem como dados de pesquisas científicas que abarquem a questão do desligamento institucional, mais especificamente neste estudo. O presente estudo teve como objetivos: a) descrever o processo de desligamento institucional sob a óptica de adolescentes que viveram em situação de acolhimento institucional por um período prolongado e das dirigentes; b) descrever o funcionamento de uma instituição de acolhimento sob a óptica do dirigente da instituição. Tratou-se de uma pesquisa qualitativa, de caráter exploratório. Participaram do estudo duas dirigentes de duas Instituições de Acolhimento e seis indivíduos que permaneceram em situação de acolhimento além do tempo permitido por lei, dois anos e que completaram maioridade, motivo inclusive, que acarretou o desligamento. Os instrumentos utilizados para coleta de dados foram: Roteiro de Entrevista 1) As características da Instituição de Acolhimento e Roteiro de Entrevista 2) O Desligamento Institucional, ambos foram aplicados com os dirigentes das Instituições de Acolhimento e ainda, Roteiro de Entrevista 3) As Conseqüências do Desligamento Institucional realizado com os ex-acolhidos. As perguntas dos roteiros de entrevista foram submetidas, antes da sua aplicação, a juizes que apontaram sugestões para melhor compreensão do contexto. A aplicação das entrevistas ocorreu em momentos distintos e em locais previamente escolhidos pelos participantes. Por intermédio dos instrumentos foram realizadas análises quantitativas, obtidas a partir das categorias definidas, tendo como parâmetro principal a análise de conteúdo. Os resultados indicaram que em alguns aspectos as Instituições pesquisadas se descreveram de forma diferente, pois, apresentaram diferentes tipos de condutas no que se refere à execução de algumas de suas funções, entre estas, humanização do processo de desligamento, preparação gradativa para o referido momento, manutenção dos vínculos familiares, apoio à reestruturação familiar, incentivo à convivência com outras famílias, participação nos serviços oferecidos pela comunidade local. Outros aspectos institucionais descritos pelas dirigentes, se caracterizaram de forma igualitária e se referem à semelhança residencial, manutenção dos vínculos afetivos entre irmãos, atendimento em pequenos grupos, entre outros. A maioria dos adolescentes apontou que o desligamento institucional foi um momento permeado por sentimento de tristeza, medo, insegurança, lembranças, tendo o individuo se preparado ou não para vivenciar este momento e suas conseqüências estavam relacionadas à dificuldade em arrumar emprego, viver sozinho, manter-se financeiramente. Conclui-se que há necessidade de políticas públicas especificas que abarquem a questão do desligamento Institucional, que ampare o adolescente financeiramente, emocionalmente, socialmente, antes, durante e após o referido processo. Indica-se ainda, a necessidade de capacitação para todos os atores sociais envolvidos com situação de acolhimento Institucional para melhor atuação e compreensão do contexto.
143

BIOACTIVE AND ALLERGENIC PROPERTIES OF EDIBLE CRICKET (GRYLLODES SIGILLATUS) PEPTIDES

Felicia G Hall (9739430) 10 December 2020 (has links)
<p>Cardiovascular diseases (CVD) and their risk factors remain the leading cause of morbidity and mortality in North America. Food-derived bioactive peptides (BAP) have been shown to play a role in regulating physiological pathways of CVD risk factors including hypertension, diabetes, and chronic inflammation. Common sources of BAP include dairy and plant proteins. In addition to being an alternative protein source, it is now accepted that edible insect proteins can also confer health benefits beyond nutrition. However, as with any novel protein source, allergenicity remains a major concern surrounding edible insect consumption. </p> <p>This dissertation aimed to: 1) Evaluate the bioactive potential of peptides from an edible cricket species and; 2) determine the effects of BAP production methods on immunoreactivity. First, peptide-rich extracts were generated from farmed food-grade crickets via enzymatic hydrolysis techniques with the commercial protease Alcalase™. To measure the <i>in vitro</i> bioavailability, cricket peptides were also subject to simulated gastrointestinal digestion (SGD). Peptides and their digests were tested for relevant bioactivities and active groups were further fractionated by chromatographic methods to identify the major peptides responsible for the bioactivity. When tested for <i>in vitro</i> antihypertensive and anti-glycemic properties, cricket peptides were found to inhibit the activities of angiotensin converting enzyme, dipeptidyl peptidase-4, α-amylase, and α-glucosidase. The anti-inflammatory potential was expounded using RAW-264.7 macrophages and human umbilical vein endothelial cells (HUVEC). Cricket peptides (after SGD) effectively lowered NF-κB, MCP-1, and IL-6 production in cells without affecting their viability. Proteomic analyses identified 18 sequences from the enriched cationic peptide fraction that showed the highest activity. Three novel peptides were identified via molecular docking, as potent ACE-inhibitors and binding was similar to that of the commercial drug captopril. Key binding characteristics included interaction with hydrophobic amino acids (Phe, Pro, Leu) near the C-terminal position and coordination with Zn (II) ions near the ACE active site.</p> <p>Immunological reactivity was measured by IgE-binding from shrimp-allergenic patient sera to antigens present within cricket peptides. Our studies demonstrate that immunoreactivity was impacted by enzymatic hydrolysis, depending on the conditions and heating source used. Tropomyosin (a major shrimp allergen) was extracted from both untreated crickets and protein hydrolysates, and verified as the major reactive protein. Tropomyosin reactivity decreased (under both partial and extensive hydrolysis) or retained (under conditions which prevented epitope cleavage). However, using microwave-assisted enzymatic hydrolysis was effective at decreasing tropomyosin reactivity in all immunoassays tested (IgG and IgE). Proteomic and immunoinformatic analyses revealed prominent allergen binding regions of cricket tropomyosin available for cleavage during enzymatic hydrolysis. Conserved antigen regions showed greater homology with other crustacean species, but not with other well studied allergenic insect proteins (i.e., cockroach). Lastly, LC-MS/MS and FT-Raman spectrometry suggests that reactivity was affected due to distinct epitope cleavage within the protein instead of decreased antigen extractability/solubility. </p> <p>The findings of this dissertation support that edible cricket proteins are a potential source of bioactive peptides for functional food or nutraceutical development. Additionally, using protein extraction methods such as microwave-assisted hydrolysis seems a promising tool for minimizing the immunoreactivity of the allergen present in this edible cricket species.</p>
144

Implementation and Sustainability of Trauma-Informed Care Via Multi-Tiered System of Support (MTSS)

Brice, Aisha Larie Elloie 01 January 2022 (has links)
Trauma-informed care is a relatively new construct in K-12 education, and districts across the United States are seeking avenues to meet the needs of their students. The COVID-19 pandemic elevated the need for districts to develop appropriate supports to address student and adult trauma. Traumatic events can affect a child’s mental, physical, social-emotional, and/or spiritual well-being (Substance Abuse and Mental Health Service Administration, 2011). Furthermore, children with an elevated risk of trauma may not be able to access these supports outside of the school setting (Baweja et al., 2015). Therefore, educational systems need to develop trauma-informed care models for schools that furnish a sense of safety and community so that students receive the necessary support. This evaluation aimed to identify how the moderating factors of district administrators, site administrators, climate and culture, and teacher capacity affect trauma-informed care via a multi-tiered system of support (MTSS) framework. It included a specific focus on Tier 1, universal access, to improve timely support for students. This formative program evaluation explored the impact of the moderating factors through the viewpoint of a newly created conceptual framework. I used qualitative and quantitative data sources to explore the multiple aspects of the phenomenon. The ARTIC-45 provided descriptive statistics about educators’ attitudes toward trauma-informed care. The observational data and analysis of the Panorama Education social-emotional learning (SEL) survey that assessed 3rd-12th students social-emotional well-being provided character to the evaluation. The data analysis yielded inconsistent results. The observational data strongly indicated a trauma-informed environment in which students were given clear expectations and engaged in positive reciprocal interactions with peers and adults. The ARTIC-45 data showed that administrators, teachers, and support staff responded favorably to trauma-informed care approaches. Though statistical significance could not be obtained due to the sample size constraint of being too small, the data provided context to the other data sources. For example, teacher capacity could not be quantified, but the data provided context to the overall staff capacity. The review of the archival and current SEL survey data showed that favorability among domains varied by site and grade level. The variations in students' social-emotional favorability can be related to their lived experiences and it is important to track over time to monitor how experiences, expressions, and feelings change over time. Students' perspectives regarding themselves and their environment differed from the observational data. This indicates that educators should not solely rely on observational data to determine students’ social-emotional well-being. Furthermore, an SEL survey can be used as a tool to understand students’ well-being and thus provide them with timely support. The evaluation determined that district administration, site administration, climate and culture and staff capacity can positively impact a multi-tiered, trauma-informed care environment. In these settings, student behavior and social-emotional well-being is viewed in a healing-centered manner. Districts can create a multi-tiered, trauma-sensitive culture and provide support to enhance teachers’ capacity to implement trauma-informed care, take advantage of administrative influence, develop community partnerships, and create a culture that is open to systematic change.
145

New Advances in High-quality Screening by Capillary Electrophoresis: A Unified Platform for Thermodynamic and Kinetic Characterization of Protein-Small Molecule Interactions / High-quality Screening by Capillary Electrophoresis

Gavina, Jennilee 12 1900 (has links)
<p> The development of high-quality screening assays for the identification of biologically active ligands is critical in drug discovery. This thesis is aimed at developing new advances m capillary electrophoresis (CE) for the characterization of the conformational stability and enzymatic activity of protein targets with small molecules. CE provides a convenient platform for unbiased assessment of multiple thermodynamic and kinetic parameters associated with biomolecular interactions involving regulatory protein or isomerase enzymes, where various sample pretreatment steps can be integrated directly in-capillary during analysis. The first two chapters of the thesis (Chapters II, III) outline the development of dynamic ligand exchange-affinity capillary electrophoresis (DLEACE) as a novel strategy for the screening of allosteric ligands based on the differential stability of urea-induced unfolding of various apolholo-protein states of cAMP receptor protein constructs. This work introduced a label-free and multivariate approach for ligand selection based on complementary thermodynamic parameters that allowed for determination of the dissociation constant of protein-ligand interactions over a wide dynamic range (> 10^4, Kd = nM-mM). The subsequent two chapters of the thesis (Chapters IV, V) describe the development of a novel kinetic assay for unbiased characterization of isomerase activity associated with D/L-amino acid metabolism using hydroxyproline epimerase as a model system. Stereoselective resolution of various hydroxyproline isomers was accomplished via off-line or on-line chemical derivatization with dynamic complexation usmg chiral selector(s) in order to screen potential inhibitors for putative epimerase and racemase activity. The integration of both thermodynamic and kinetic strategies for differentiation of mutant from wild-type enzymes was important for revealing the function of a catalytic acid/base cysteine pair in the epimerase active site. Overall, this thesis outlines an integrative framework based on CE for high-quality screening, which is relevant in reducing the high attrition rate of lead candidates in drug development. </p> / Thesis / Doctor of Philosophy (PhD)
146

Cross-Reactivity of IgG Antibodies and Virus Neutralization in mRNAVaccinated People Against Wild- Type SARS-CoV-2 and the Five Most Common SARS-CoV-2 Variants of Concern

Schwarze, Mandy, Krizsan, Andor, Brakel, Alexandra, Pohl, Fabian, Volke, Daniela, Hoffmann, Ralf 11 July 2023 (has links)
The rapid development, approval, and production of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in less than 1 year after the first reports of a new infectious disease was a real game changer, providing 80%–90% efficacy in preventing severe etiopathologies of the coronavirus disease 2019 (COVID-19). These vaccines induce an immune response against the SARS-CoV-2 spike (S) protein located on the surface of the virus particle. Antibodies (Abs) recognizing the S-protein can inhibit binding of the virus via the S-protein to the angiotensin-converting enzyme-2 (ACE-2) receptor expressed on different human cells, especially when these Abs bind to the interaction site, the so-called receptor-binding domain (RBD). We have expressed the RBDs of wild-type SARS-CoV-2 and five variants of concern (VOCs) to test the immune response in people before vaccination with mRNA vaccines BNT162b2 and mRNA-1273 and after up to three vaccinations using in-house ELISA and inhibition assays. The methods of both assays are provided. Both vaccines initiated similarly high IgG titers after two vaccinations against the wild-type and even two VOC-RBDs (alpha and delta) and strongly inhibited the corresponding RBD-ACE-2 binding. The IgG titers and inhibition of ACE-2 binding were lower for beta and gamma RBDs and much lower for omicron RBD. The third vaccination after 6 months strongly increased both the IgG titers and the neutralizing effect against all variants, especially for omicron, leading to 63% ± 13% neutralization potential. Importantly, neutralization linearly increased with the IgG titers.
147

Prävention des Nierenversagens und der Nierenfibrose bei hereditären Erkrankungen der glomerulären Basalmembran (Alport-Syndrom) bei COL4A3-Knockout-Mäusen mit dem Reninantagonisten Aliskiren / Prevention of renal failure and renal fibrosis in hereditary diseases of glomerular basement membrane (Alport-Syndrome) in COL4A3 knockout mice with Aliskiren a direct renin inhibitor

Theisen, Stephanie 04 June 2012 (has links)
No description available.
148

Adverse Childhood Experiences and Couple Relationships: Impacts on Relationship Quality and Partner Selection

Redd, Michael John January 2017 (has links)
No description available.
149

Intravital imaging of hemodynamic glomerular effects of enalapril or/and empagliflozin in STZ-diabetic mice

Kroeger, Hannah, Kessel, Friederike, Sradnick, Jan, Todorov, Vladimir, Gembardt, Florian, Hugo, Christian 30 May 2024 (has links)
Background: Diabetic kidney disease is the leading cause of end-stage renal disease. Administration of ACE inhibitors or/and SGLT2 inhibitors show renoprotective effects in diabetic and other kidney diseases. The underlying renoprotective mechanisms of SGLT2 inhibition, especially in combination with ACE inhibition, are incompletely understood. We used longitudinal intravital microscopy to directly elucidate glomerular hemodynamics on a single nephron level in response to the ACE inhibitor enalapril or/and the SGLT2 inhibitor empagliflozin. Methods: Five weeks after the induction of diabetes by streptozotocin, male C57BL/6 mice were treated with enalapril, empagliflozin, enalapril/empagliflozin or placebo for 3 days. To identify hemodynamic regulation mechanisms, longitudinal intravital multiphoton microscopy was employed to measure single nephron glomerular filtration rate (snGFR) and afferent/efferent arteriole width. Results: Diabetic mice presented a significant hyperfiltration. Compared to placebo treatment, snGFR was reduced in response to enalapril, empagliflozin, or enalapril/empagliflozin administration under diabetic conditions. While enalapril treatment caused significant dilation of the efferent arteriole (12.55 ± 1.46 µm vs. control 11.92 ± 1.04 µm, p < 0.05), empagliflozin led to a decreased afferent arteriole diameter (11.19 ± 2.55 µm vs. control 12.35 ± 1.32 µm, p < 0.05) in diabetic mice. Unexpectedly under diabetic conditions, the combined treatment with enalapril/empagliflozin had no effects on both afferent and efferent arteriole diameter change. Conclusion: SGLT2 inhibition, besides ACE inhibition, is an essential hemodynamic regulator of glomerular filtration during diabetes mellitus. Nevertheless, additional mechanisms—independent from hemodynamic regulation—are involved in the nephroprotective effects especially of the combination therapy and should be further explored in future studies.
150

Is the endothelial nitric oxide synthase (eNOS) gene a susceptibility gene for coronary artery disease, hypertension and type 2 diabetes among North Indian populations?

Fitt, Jacqueline S. January 2011 (has links)
Coronary artery disease (CAD), Hypertension (Ht) and Type 2 Diabetes Mellitus (T2DM) are all global health problems. This is particularly evident amongst South Asian population groups. The conventional risk factors do not fully explain the higher prevalence of these diseases among South Asians. The endothelial Nitric Oxide Synthase (eNOS) gene is responsible for the production of Nitric Oxide (NO), which may contribute to the physiology of all three disease states. Endothelial dysfunction (which is characterised by a reduction in basal NO) has been shown to be present in, or prior to all three diseases. Numerous variations exist within the eNOS gene, of these variations three have been shown to have a possible functional effect. The first is the Glu298Asp polymorphism within the exon region of the gene, resulting in an amino acid substitution of Glutamate (Glu) to Aspartate (Asp). The second, known as the T-786C polymorphism, is a thymine to cytosine mutation at position -786 in the promoter region. Finally a VNTR polymorphism in Intron 4 causes either a 4 27bp repeat or a 5 27bp repeat. It is hypothesised that these variations could have an effect on the ability of eNOS to produce NO and thus may increase the risk or contribute to the development of the diseases. Previous studies on these variants have shown conflicting results and further studies are warranted to understand and confirm the role of eNOS gene polymorphisms in cardio-metabolic diseases. There is very limited research into the distributions of these genetic variants and their interaction in diseases processes in North Indian populations. Objectives: 1. To analyse through a case control study three different polymorphisms of the eNOS gene for possible association with Coronary Artery Disease (CAD), Hypertension (Ht) and Type 2 Diabetes Mellitus (T2DM) in North Indian population groups. 2. To statistically evaluate descriptive statistics including; age, gender, smoking, dietary behaviours and lipid parameters for possible influence on disease and potential interaction with genetic polymorphisms. 3. To evaluate linkage disequilibrium between the three eNOS variants and carryout haplotype analysis to work out haplotype risk in different diseases. 4. To analyse through a case control study the deletion variant of the Angiotensin-converting enzyme (ACE) gene for possible association with Coronary Artery Disease (CAD), Hypertension (Ht) and Type 2 Diabetes Mellitus (T2DM) in North Indian population groups. 5. To determine a possible interactive effect of the eNOS polymorphisms with the ACE polymorphism. Subjects and Methods: The Glu298Asp and Intron 4 variants were genotyped using a PCR-RFLP technique, the T-786C variant was genotyped using a real time-PCR technique. The ACE deletion variant was also genotyped using a standard PCR technique. The genotyping was undertaken in a total of 457 CAD patients and 220 matched controls from Lucknow, Uttar Pradesh in North India, 319 T2DM patients and 307 matched controls from Punjab, North India and 210 Ht and 162 matched controls, also from Punjab, North India. Results: CAD: The Glu298Asp was significantly associated with CAD among smokers (TT+GT vs. GG OR=2.84 (CI: 1.61-5.0), p<0.001). The Intron 4 variant was also significantly associated with CAD in a smoking dependent manner (4aa+4ab vs. 4bb OR=0.56 (CI: 0.33-0.96). The T-786C variant showed no overall influence on CAD risk. There was also evidence for both synergistic and haplotypic effects of the eNOS gene on CAD status (haplotype G-C-4b OR=4.76 (CI: 1.43-15.78), p<0.001). The ACE genetic variant was confirmed to be a strong independent risk factor for CAD under a dominant model (OR=2.18 (CI: 1.46-3.25), p<0.001). There was no evidence for an interactive effect between the ACE deletion and any of the three eNOS variants incorporated in the current study. Ht: The Glu298Asp variant was not shown to increase Ht risk, with a reduced risk association found under a recessive model (OR=0.316 (CI:0.089-1.116)), p=0.061). The T-786C variant s role in disease remained unclear with the findings showing a non significant increased risk. The Intron 4 variant was also shown to increase Ht risk, in a non significant manner. Sufficiently powered studies would be required to clarify these possible associations. The combined analysis, using logistic regression and haplotype analysis revealed no significant associations, but there was a possible protective effect of the T-C-4b haplotype (OR=0.46 (CI: 0.21-1.01), p=0.054). The ACE gene variant was confirmed to be a strong independent risk factor for Ht under a recessive model (OR=1.81 (CI: 1.20-2.74), p=0.01). Again there was no evidence for an interactive effect between the ACE deletion and any of the three eNOS variants in hypertension. T2DM: The Glu298Asp variant was found to be associated with T2DM under a dominant model, the protective effect remained significant following adjustment for conventional risk factors and other gene variants (OR=0.407 (CI: 0.231-0.717), p=0.002). The T-786C variant showed no overall influence on T2DM risk. The Intron 4 variant also found no overall influence. Haplotype analysis found the T-T-4b was found to be significantly protective for T2DM (OR=0.41 (CI: 0.26-0.65), p=0.0002). Finally the ACE gene variant was confirmed to be a risk factor for T2DM under a dominant model (OR=2.62 (CI: 1.51-4.54), p=0.001). Overall Conclusions: To conclude, this study successfully identified the frequency of three eNOS gene variants and the ACE deletion variant in three complex diseases within north Indian populations. There is a clear role of the eNOS gene in all three diseases and consequently the genetic variants have susceptible/protective associations. The association with disease was found to be present at an individual level, in association with risk factors and at a haplotypic level. These findings warrant further studies to confirm and untangle the genetics of complex diseases and genetic risk profiles calculations which will contribute to the field of medical genomics/personalised medicare and interventions among North Indian populations.

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