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Thesis (Ph. D.)--University of Texas Health Science Center at Houston, School of Public Health, 2007. / Source: Dissertation Abstracts International, Volume: 68-10, Section: B, page: 6618. Adviser: Marsha L. Frazier. Includes bibliographical references.

Thesis (doctoral)--Katholieke Universiteit te Nijmegen.

Excessive fructose consumption in Western diets correlates with increases in obesity, insulin resistance, kidney disease, and non-alcoholic fatty liver disease (NAFLD), collectively part of metabolic syndrome (MBS). Liver and kidneys metabolize 50-70% of ingested fructose, but the fate of remaining fructose remains poorly understood. Moreover, the correlation of fructose ingestion with MBS highlights the need for better understanding of whole-body fructose metabolism, in both health and disease. To that end, valid rodent models for fructose metabolism must reflect the same metabolism in humans. A serious autosomal recessive defect in fructose metabolism, called hereditary fructose intolerance (HFI), is caused by mutations in the aldolase B gene (ALDOB, human; Aldo2, mouse). With low levels of fructose exposure, HFI patients develop NAFLD and liver fibrosis, sharing pathologies with MBS. Targeting Aldo2 for deletion in mice (Aldo2-/-) provides a major step in validating that fructose metabolism in mice mimics that in humans. Like HFI patients, Aldo2-/- mice exposed to chronic, low-level dietary fructose show failure to thrive, liver dysfunction, and potential mortality. The fructose-induced symptoms of HFI and MBS result from flux through the ketohexokinase (KHK)-mediated pathway, and the metabolite Fru 1-P. Bioinformatic analysis reveals gene expression for this pathway is highest in liver, as expected; surprisingly, brain is predicted to have expression levels similar to kidney. This predicted gene expression is validated via RNA in situ hybridization, quantification of enzyme activities, presence of transport proteins, and measuring fructose oxidation rates in adult mice brains. Within the brain, regions of the cerebellum, hippocampus, cortex, and olfactory bulb show the highest population of cells expressing Fru-1-P pathway genes. In these regions, enzyme activities for both KHK and aldolase, and rates of fructolytic flux, are many times that seen in liver slices. Additionally, brains of mice on a high fructose diet show a three-fold increase in KHK activity. This suggests that not only are these regions of the brain capable of metabolizing fructose, but that they are also capable of responding to increases in dietary fructose. This work provides a foundation for research of long-term consequences of excessive fructose consumption in multiple organs. / 2017-06-21T00:00:00Z

As doenças neuromusculares incluem um grupo muito heterogêneo de patologias que atingem 1 em cada 1.000 indivíduos nascidos vivos. Dentre as doenças neuromusculares destacam-se as paraplegias espásticas hereditárias que acometem, aproximadamente, cerca de 1 em cada 10.000. As paraplegias espásticas hereditárias (PEH) são caracterizadas pela espasticidade e fraqueza muscular dos membros inferiores. São muito heterogêneas tanto em clínica como geneticamente. Diversas formas já foram descritas e a mais comum delas, acometendo por volta de 40% dos casos autossômicos dominantes, causada por mutações no gene SPAST (PEH do tipo 4 ou SPG4). Estudos de correlação genótipo: fenótipo têm mostrado que indivíduos da mesma família carregando a mesma mutação patogênica, podem ter quadro clínico muito distinto. A explicação para esta questão pode estar na procura por genes modificadores, no padrão de expressão, na análise proteômica (seja por ligantes a proteínas ou no dobramento das mesmas), ou em mecanismos epigenéticos. Além disso, em algumas formas observa-se uma diferença na porcentagem de pessoas afetadas de acordo com o sexo. Essa desproporção foi observada numa grande família de com PEH na qual existe um predomínio de afetados do sexo masculino. O objetivo do presente trabalho foi a análise de pacientes discordantes, ou seja, que possuam a mesma mutação, porém com quadro clínico discordante de uma grande família brasileira com SGP4. Para isso foi feito um estudo da abundância de transcritos (mRNA) e de genótipo (polimorfismos de base única) em relação a um fenótipo (sintomático ou assintomático). Os resultados sugerem que o principal sistema envolvido, que poderia explicar as diferenças entre os pacientes discordantes, é o sistema imune, com a principal atuação dos genes C2, HLA-DRB1 e LY6G6C. Esses genes podem ter papel protetor ou tóxico no desenvolvimento do quadro clínico dos pacientes analisados / The hereditary spastic paraplegia (HSP) is characterized by muscle weakness and lower limb spasticity. They are very heterogeneous both clinically and genetically. Several forms have been described and the most common one, affecting around 40% of autosomal dominant cases, is caused by mutations in the SPAST gene (HSP type 4 or SPG4). Genotype: phenotype correlation studies have shown that affected individuals from the same family, who carry the same pathogenic mutation, can have very distinct phenotypes. The underlying explanation behind this clinical heterogeneity may be found in the search for modifier genes, in expression patterns observed proteomic analyses (either by protein binding or folding), or epigenetic mechanisms. As is observed in other motor neurodisease, there is a disproportion between the number of affected males and females, with males being the predominantly affected. The objective of this study was to analyze discordant patients, i.e., those that possess the same mutation, but show discordant phenotypes, from a large Brazilian family with SGP4. For this study, the abundance of transcripts (mRNA) and genotype (single nucleotide polymorphisms) relative to a phenotype (symptomatic or asymptomatic) were analyzed. The results suggest that the main system involved, which could explain the differences between discordant patients, is the immune system, with the main activity of C2, LY6G6C and HLA-DRB1 genes. These genes may have a protective or toxic role in the development of the analyzed patients\' clinical features

Orientador: Carmen Sílvia Bertuzzo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T04:59:08Z (GMT). No. of bitstreams: 1 Assis_AngelaMariade_D.pdf: 2409399 bytes, checksum: 620279a2d72b5132a10f7af956d4bebf (MD5) Previous issue date: 2007 / Resumo: A Telangiectasia Hemorrágica Hereditária (THH) é uma desordem autossômica dominante caracterizada por epistaxe recorrente, telangiectases mucocutânea, hemorragia gastrointestinal, e malformação arteriovenosa pulmonar (PAVM), cerebral e hepática. A prevalência da doença é de 1/5000 e a mortalidade relatada da doença entre pacientes jovens quando comparado com aqueles com mais de 60 anos é de 36%. Dois genes da superfamília de receptores para TGF-? têm sido relacionados com THH, o gene da endoglina e o gene da activina (activin receptor-like-kinase). Estes genes são altamente expressos em células endoteliais e outros tecidos altamente vascularizados como pulmão e placenta. Mutações no gene da endoglina causam a THH tipo 1 que é caracterizada pela alta incidência de malformação arteriovenosa pulmonar sintomática (PAVMs). Mutações no gene da activina levam a THH tipo 2 caracterizada por epistaxe recorrente e malformação arteriovenosa gastrointestinal. Foi objetivo deste trabalho realizar uma triagem de mutações na região codificadora dos genes ALK-1 e endoglina em doze pacientes portadores de THH atendidos no Hemocentro da Unicamp. A abordagem metodológica incluiu a amplificação dos exóns dos genes da activina e endoglina seguida pela técnica de PCR/CSGE, clonagem e sequenciamento. Dos doze pacientes estudados, sete apresentaram alguma alteração molecular, destes três pacientes apresentaram uma deleção de um nucleotídeo T na posição 913 no exon 7, um paciente apresentou uma inserção de um nucleotídeo G na posição 204-205 no exon 3 e três pacientes apresentavam uma mutação misense nos exons 7 e 8 na posição 976 e 1204 respectivamente. Nossos resultados mostraram que a THH tipo 1 e tipo 2 são raras no Brasil e todas as mutações citadas na tabela IV e Figura 10 são novas, somente a mutação ocorrida no exon 8 foi previamente descrita na literatura / Abstract: Background: Hereditary hemorrhagic telangiectasia in humans, also known as HHT or Osler-Rendu-Weber syndrome, is an autosomal dominant vascular disorder characterizes by recurrent epistaxis, mucocutaneous telangiectases, gastrointestinal, pulmonary, cerebral and hepatic arteriovenous malformations (HAVM). The prevalence of the illness is of 1/5000 and the reported mortality of the illness among young patients when compared with those with more than 60 years is 36%. Two genes of the receptors superfamily for TGF-? have been related with THH, the gene of the endoglin (ENG) in the chromosome 9q33-34 and the gene of the activin (receptor-like-kinase 1 ALK-1), in the chromosome 12q11q14. These genes are highly express in endothelial cells and other tissue highly vascularized as lung and placenta. Mutations in the gene of the endoglin cause the HHT type 1 which is characterized by the high incidence of symptomatic pulmonary arteriovenous malformation (PAVM). Mutations in the activin gene cause HHT were described among patients in whom the linking with HHT in the chromosome 9q33 or mutation in the endoglin gene was excluded. It was the objective of this work to carry through a selection of mutations in the coding region of gene ALK-1 and endoglin in 12 patients carrying HHT whose are treated in the Blood Center at Unicamp. Methods: Twelve patients were analyzed. Diagnosis of HHT was carried out by means of clinical history of recurrent bleeding, heredity studies, and the presence of multiple telangiectases lesions. PCR products with consistent abnormal migration patterns were cloned into the SureCloneTM ligation kit vector system and sequenced using the DYEnamic TM ET dye terminator cycle sequencing Kit, and analyzed by the MegaBace 1000 DNA automated analyzer. A panel of 252 chromosomes from unrelated individuals without the disease was used to evaluate the frequency of each mutation in the general population. Results: In six patients three novel mutations were identified in the coding sequence of the ALK-1 gene in their families, which demonstrated clinical manifestations of HHT type 2. These mutations included an insertion a deletion of single base pairs in éxons 3 (c.204-205insG) and 7 (c.913del T), as well as missense mutations in éxons 7 (c.976A>G) and 8 (c.1204G>A) of the ALK-1 gene. The mutations identified in éxons 7 and 8 affect the kinase domain and the mutation identified in éxon 3 affect the extracellular domain. These data indicate that loss-of-function mutations in a single allele of the ALK1 locus are sufficient to contribute to defects in maintaining endothelial integrity. Conclusion: We suggest the high rate of mutation detection and the small size of the ALK-1 gene make genomic sequencing a viable diagnostic test for HHT2. This was the only research about this subject made in Brazil so far / Doutorado / Genetica Animal e Evolução / Doutora em Genética e Biologia Molecular

Over the past forty years, there has been an increase in obesity, diabetes, and heart disease, collectively known as metabolic syndrome (MetS), in which fructose has been implicated. In addition to MetS, hereditary fructose intolerance (HFI) has no known treatment aside from the difficult removal of fructose from the diet. Ketohexokinase (KHK) is the first enzyme in the fructose metabolic pathway and catalyzes an ATP-dependent reaction that phosphorylates fructose to fructose 1-phosphate. For effective inhibitor development, it is key to understand the KHK-catalytic mechanism. To that end, the research described in this thesis focuses on two goals: 1) understanding how KHK functions in its role as a metabolic enzyme, using structure-function analysis to inform the development of KHK inhibitors, and 2) investigating how these findings can be used to make KHK a prime therapeutic target for alleviating diseases such as HFI and MetS. The X-ray crystal structure of the mouse-liver isozyme, KHK-C (mKHK-C), was determined at a resolution of 1.79 Å. The mKHK-C structure is in complex with the substrate fructose and the product of catalysis, ADP, forming a ground-state complex. The mKHK-C structure has nearly identical secondary structure to its human homolog and has similar steady-state kinetic parameters validating the use of mouse models for exploring the pre-clinical efficacy of KHK-C inhibitors. Furthermore, six structures of human KHK-C in complex with inhibitors and ligands are presented. These structures support the kinetic analyses showing these inhibitors are all competitive with ATP and reveal the shape and polarity of the ATP-binding pocket to achieve inhibition constants (Ki) as low as 50 nM. Lastly, comparison of all KHK structures demonstrate that the β-sheet domain of KHK is capable of 30.3° rotation of the β-sheet domain towards the active site of the opposing dimer subunit. Kinetic experiments using site-directed mutants of human KHK-C and various viscogens confirmed that a conformational change is linked to KHK’s catalytic function. This research provides a foundation for further development of more specific KHK inhibitors aimed at HFI and MetS therapies. / 2022-10-30T00:00:00Z

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22737号 / 医博第4655号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊佐 正, 教授 林 康紀, 教授 髙折 晃史 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

The incidences of maternal opioid use and neonatal opioid withdrawal syndrome (NOWS) have increased by nearly 400% over the past decade. Isemann and colleagues (2017) developed prediction tools (TiTE/TiTE2) to differentiate, within the first two days of life, between infants who will require pharmacotherapy for NOWS from those infants who will not require pharmacotherapy for NOWS. The goal of the current experiment was to replicate and extend their prediction model. The present experiments successfully replicated Isemann et al., (2017) results and also established alternative cutoff values for requiring treatment that provide better balance between all four metrics. Moreover, new prediction models (TEN/TEN2) were proposed based on a factor analysis of modified Finnegan scores across the first 48 hours of life. Area Under the Curve-Receiver Operating Characteristic curve analyses indicated that the TEN2 was the best prediction model compared to the TiTE2 and the TEN.

Background: When women from families with a known BRCA1 or BRCA2 mutation test negative for the family mutation, it is assumed that they will transition their personal cancer risk perception from high to average risk. However, there are scant data regarding the experience of mutation-negative women after genetic testing disclosure, particularly related to the shift of risk perception from assumed mutation-positive to actual mutation-negative. This study was designed to explore cancer risk perception and the experience of being a mutation-negative woman within a known BRCA1/2 mutation-positive family. Methods: We employed a qualitative descriptive design and convened a sample of 13 women who contributed in-depth, semi-structured telephone interviews (audio-recorded and transcribed verbatim) and performed qualitative content analysis with NVivo 2.0 software. Results: Six major content areas emerged from interview data: (i) rationale for initial involvement in the breast imaging study, (ii) rationale for continued participation, (iii) experience of living in a multiple-case family, (iv) risk perception: the personal meaning of mutation-negative status, (v) opinions regarding cancer aetiology and (vi) communication patterns between mutation-negative and mutation-positive family members. Conclusions: Living in a hereditary breast and ovarian cancer family is a complex experience that affects cognitive, emotional and social functioning. Our findings indicate that mutation-negative women may have unmet psychosocial needs that must be addressed by health-care professionals, particularly in the primary-care setting following genetic disclosure of a potentially reassuring result regarding their lack of the very high cancer risks associated with BRCA1/2 mutations.