O aborto espontâneo recorrente (AER) caracteriza-se pela ocorrência de três ou mais abortos consecutivos espontâneos até a 20ª semana de gestação. É uma condição patológica multifatorial, em que alterações morfológicas uterinas, distúrbios endócrinos, alterações no cariótipo, polimorfismos genéticos relacionados aos genes envolvidos no metabolismo da homocisteína, hemostasia, infecções, autoanticorpos e o processo inflamatório podem contribuir para a ocorrência de AER. O estado fisiológico do endométrio é essencial para a implantação do embrião no útero durante a gestação. Na interface materno-fetal, há uma modulação de citocinas, necessária para o estabelecimento da angiogênese e desenvolvimento da placenta. Um desequilíbrio entre as citocinas pode diminuir a tolerância ao feto e ocasionar rejeição fetal. A concentração de citocinas pode ser modificada por conta de uma diminuição na expressão de alguns genes, e esta pode ser regulada pelo seu estado de metilação sítio-específica. A metilação do DNA é um mecanismo epigenético de regulação gênica, e que corresponde à incorporação de grupos metila em ilhas CpG localizadas próximas às regiões promotoras de genes humanos, e isso pode ser importante na avaliação do risco de complicações gestacionais. Além disso, o estado nutricional de vitaminas foi relacionado a alterações no padrão de metilação de alguns genes. Os objetivos deste trabalho foram avaliar as concentrações dos mediadores inflamatórios em mulheres com aborto e em grupo controle, verificar correlações entre as concentrações de vitaminas, homocisteína total e taxa de metilação do DNA, verificar correlações entre concentração de citocinas e taxa de metilação do DNA e determinar odds ratio (IC 95%) de ter aborto em modelos multivariados. Foram incluídas 253 mulheres com história de aborto recorrente e 264 mulheres saudáveis (controle). O DNA foi extraído de leucócitos de sangue periférico para o estudo de metilação. Foram separadas alíquotas de soro e plasma para dosagem de vitaminas, metabólitos e citocinas. Não foram encontradas diferenças nas taxas de metilação do DNA entre os grupos aborto e controle. A citocina TNFα está aumentada nos grupos de aborto em comparação ao controle. A taxa de metilação do DNA no gene IFNG foi correlacionada inversamente às concentrações de folato sérico e citocina IFNγ no grupo controle. E as concentrações de IL10 foram inversamente correlacionadas à taxa de metilação do DNA nos grupos de aborto secundário e controle. Neste trabalho, verificou-se que as vitaminas e as citocinas influenciam na taxa de metilação do DNA do gene IFNG e a citocina pró-inflamatória TNFα apresenta-se aumentada em mulheres com história de aborto. / Recurrent spontaneous abortion (RSA) is characterized by the occurrence of three or more consecutive spontaneous abortions until the 20th week of gestation. It is a multifactorial pathological condition in which morphological uterine, endocrine disorders, changes in the karyotype genetic polymorphisms related to genes involved in homocysteine metabolism, infection, autoimmunity and inflammatory processes may contribute to the occurrence of RSA. The physiological state of the endometrium is essential for embryo implantation in the uterus during pregnancy. In maternal-fetal interface, there is a modulation of cytokines necessary for the establishment and development of placental angiogenesis. An imbalance between cytokines can decrease tolerance to fetus and cause fetal rejection. Concentration of cytokines may be modified due to a decrease in the expression of genes related to some of these cytokines that can be regulated by DNA methylation, which is an epigenetic mechanism of gene regulation and which corresponds to the incorporation of groups Methyl CpG islands located near the promoter regions of human genes, and this may be important in assessing the risk of pregnancy complications. In addition, the nutritional status of vitamins was associated with changes in the methylation pattern of certain genes. The aims of this study were to determine the concentrations of inflammatory mediators in women with abortion and the control group, examine correlations between concentrations of vitamins, total homocysteine and DNA methylation rate, examine correlations between cytokine concentration and DNA methylation and determine odds ratio (95% CI) of having abortion in multivariate models. We included 253 women with a history of recurrent miscarriage and 264 healthy women (control). DNA was extracted from peripheral blood leukocytes for the study of methylation. Serum and plasma aliquots were used for determination of vitamins, metabolites and cytokines. There were no differences in rates of DNA methylation between control and abortion groups. The cytokine TNFα is increased in abortion groups compared to the control. DNA methylation rate in gene IFNG was inversely correlated with serum folate and serum cytokine IFNγ in the control group. Also IL10 concentrations were inversely correlated to DNA methylation rate in groups of miscarriage and secondary control. In this work, it was found that vitamins and cytokines influence DNA methylation rate in the promoter region and are different in the study and control groups.

Background: One key component in the development of sustainable farming and foodstuffs is to increase the cultivation of legumes, due to their environmental and health benefits. Legumes contain several essential vitamins and minerals, protein and fiber, but cultivation can be problematic due to their weak stem strength which results in loss of crops as a result of crop lodging and susceptibility to weed invasion. One possible solution is co-cultivation with cereal crops such as oats as they provide support and outcompete weed growth, however, it is still unknown if co-cultivation will affect the nutrient content of lentils. Aim: The thesis has two aims: first, to compare choline, betaine, folate, resistant starch and dietary fiber content in two different types of lentils: Gotland lentils and Anicia lentils; and second to examine if cocultivation with oats will affect the nutrient content of the two lentil types. Methods: Betaine and choline were analyzed through high pressure liquid chromatography-mass spectrometry (HPLC-MS) and folate through high pressure liquid chromatography with fluorometric/UV detection (HPLC-FL/UV). Resistant starch, non-resistant starch and dietary fiber were analyzed according to enzymatic assay kits by Megazyme. Results: Significant differences in nutrient content between Anicia and Gotland lentils were seen regarding resistant starch content, with Gotland showing a 50 % higher content. A significantly greater choline content was found in Anicia lentil samples that were co-cultivated with oats, showing approx. a 15 % higher choline content. Gotland lentils co-cultivated with oats showed a significantly greater choline, resistant starch and dietary fiber content by 15 %, 70 % and 10 %, respectively. Conclusions: There was no reported significant difference in choline, betaine, folate and dietary fiber content, but in resistant starch between the two lentil types, with Gotland lentil showing a higher resistant starch content. There appeared to be a positive effect of co-cultivation with oats since a significantly higher choline content in both lentil types co-cultivated with oats and a significant increase resistant starch and dietary fiber in Gotland lentils co-cultivated with oats was reported. This suggests that cocultivation can lead to an increase in nutritional content for some nutrients in Gotland and Anicia lentils. The dietary fiber analysis confirmed that legumes are a great source of fiber by one portion providing approx. half the recommended daily amount. Cultivation and consumption of lentils can give both environmental and health benefits. Further studies are needed to explore other pulses and effect on other nutrients. / Svenska ekologiska linser

Malaria is a fatal tropical disease affecting billions of people in impoverished countries world-wide. An alarming fact is that a child in Africa dies of malaria every 30 seconds that amounts to 2500 children per day (www.who.int/features/factfiles). Malaria is caused by the intraerythrocytic forms of Plasmodium species, notably P. falciparum, P. vivax, P. ovale and P. malariae (Hyde 2007). The spread of drug-resistant strains, failure of vector control programs, rapid growth rate of the parasite, and lack of a vaccine have further exacerbated the effects of malaria on economic development and human health. It is therefore imperative that novel drug targets are developed or current antimalarial drugs optimized (Foley and Tilley 1998). One such target is folate biosynthesis, given that folates and their derivatives are required for the survival of organisms (Muller et al. 2009). DHFR and DHPS are currently the only folate targets exploited however, their antifolate drugs are almost useless against parasite resistant strains. As such, guanosine-5’triphosphate cyclohydrolase I (GTPCHl) among other antifolate candidates are considered for intervention (Lee et al. 2001). Knock-out studies (of P. falciparum gtpchI) resulted in the suppression of DHPS activity (Nzila et al. 2005). Additionally, gtpchI amplified 11-fold in P. falciparum strains resistant to antifolates due to mutations in dhps and dhfr and this may be a mechanism for the compensation of reduced flux of folate intermediates (Kidgell et al. 2006; Nair et al. 2008). Over-expression of P. falciparum proteins in E. coli remains a challenge mainly due to the A+T rich Plasmodium genome resulting in a codon bias. This results in the expression of recombinant proteins as insoluble proteins sequestered in inclusion bodies (Carrio and Villaverde 2002; Mehlin et al. 2006; Birkholtz et al. 2008a). Comparative expression studies were conducted of native GTPCHI (nGTPCHI), codon optimized GTPCHI (oGTPCHI) and codon harmonized (hGTPCHI) in various E. coli cell lines, using alternative media compositions and co-expression with Pfhsp70. The nGTPCHI protein did not express because the gene consisted of codons rarely used by E. coli (codon bias). The expression levels of purified hGTPCHI were a greater in comparison to oGTPCHI using the different expression conditions. This is because codon-harmonization involves substituting codons to replicate the codon frequency preference of the target gene in P. falciparum, as such the translation machinery matches that of Plasmodium (Angov et al. 2008). Furthermore, greater expression levels of GTPCHI were achieved in the absence of Pfhsp70 due to expression of a possible Nterminal deletion product or E. coli protein. Purification conditions could be improved to obtain homogenous GTPCHI and further analysis (mass spectrometry and enzyme activity assays) would be required to determine the nature of soluble GTPCHI obtained. To improve the expression of soluble proteins the wheat germ expression system was used as an alternate host. However, GTPCHI expression was not effective, possibly due to degradation of mRNA template or the absence of translation enhancer elements. / Dissertation (MSc)--University of Pretoria, 2010. / Biochemistry / unrestricted

Pregnancy places great strain upon the body of a woman. Many things contribute to a successful pregnancy, such as healthy eating habits, healthy lifestyle, adequate physical activity, fresh air, good mental health. It is recommended to begin folic acid supplementation even before conception. Folic acid, known as folate, is one of the B vitamins. Pregnancy places greater need for folic acid intake, especially in the early stages, where insufficiency or even deficiency can manifest in a pathological pregnancy, oftentimes fatal. The specific link between the two is not yet very well known. However, several studies have confirmed that there is a positive effect that comes with increased folic acid intake before conception and during the first few weeks of pregnancy, most notably reduced occurrence of neural tube birth defects. General population generally doesn't have adequate intake of folic acid, so there is usually a folic acid deficit before and during pregnancy as well. This can be countered by consuming food high in folate, targeted food enrichment or direct consumption of supplements containing folic acid. The Czech Republic currently doesn't enrich food with folic acid, therefore it is recommended to increase its intake via supplementation. Research investigation through paper questionnaires...

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The global DNA methylation pattern is erased and re-established during oogenesis and again in preimplantation (PI) embryo development. Understanding where these methyl groups come from and how the process of methylation is regulated is important, as disruptions could result in detrimental effects. The methionine cycle that produces the cellular methyl pool is linked to the folate cycle. The key enzyme linking theses cycles is Methylenetetrahydrofolate Reductase (MTHFR) which converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. Mthfr RNA and protein are present throughout mouse oocyte and PI embryo development, including the germinal vesicle, MII egg, 1-cell embryo, 2-cell embryo, morula and blastocysts. In MII eggs the protein appears to be heavier than in any other stage. This was reversed by treatment with Lambda Protein Phosphatase (LPP), indicating that MTHFR is phosphorylated in MII eggs. MTHFR was progressively phosphorylated beginning shortly after initiation of meiotic maturation, reaching maximal levels in MII eggs before decreasing after egg activation using strontium chloride. Potential kinases responsible for the phosphorylation of MTHFR have been identified however not in oocytes or PI embryos. DYRK1A/1 and GSK3A/B have both been suggested to mediate the phosphorylation, however when inhibited showed no effect on the oocyte sample. An LC-MS/MS assay was attempted to measure the activity of MTHFR in wildtype and knockout mouse liver samples, however unsuccessful in the amounts needed to be used for comparison to oocytes. Overall, MTHFR is present in the developing stages of interest and is mediated in some capacity by phosphorylation modifications around the MII stage of development.

Despite the recent advances in cancer therapy, the successful detections and treatments of cancer still remains a challenge. The existing strategies for early cancer detection are often limited due to their poor sensitivity and specificity. Also, the non-selective action of therapeutic interventions hinders treatment success. Our research was therefore directed towards the engineering of excellent bi-functionalized nanoparticles (NPs) based on carbon dots (CDs) that would improve early cancer detection and overcome the limitations of chemotherapy. With the actively targeting agent, these new NPs are expected to effectively deliver pharmacological agents directly to cancer cells. CDs are carbon-based NPs that are utilized as bioimaging agents and drug delivery systems (DDS) due to their excellent biocompatibility, non-toxicity, unique imaging, and facile surface modification. Using folic acid (FA) as targeting agent, the prepared novel CDs will carry doxorubicin (DOX) covalently and non-covalently to the cancer cells with overexpressed folate receptors. The CDs were first synthesized via the hydrothermal bottom-up approach using citric acid and ethylenediamine as precursors. The prepared CDs were then functionalized by FA via a non-cleavable peptide bond followed by complexation with DOX covalently or non-covalently to obtain the desired FA-CD-DOX NPs. All the NPs and intermediates were characterized using ultraviolet-visible spectroscopy (UV-vis), fluorescence spectroscopy (FL), and Fourier transform infrared spectroscopy (FTIR). Assessment of the drug loading capacity (DLC) and drug loading efficiency (DLE) with UV-vis indicated that the non-covalent NPs have low DLC but high DLE compared to the relatively low DLE and high DLC of covalent NPs. In vitro drug release studies were also carried out in phosphate buffered saline (PBS) systems with various pH. It was found that even though both non-covalent and covalent complexes released more DOX at pH 5.0 than at pH 7.0, the DOX release rate was faster in the non-covalent FA-CD-DOX NPs compared to the covalent FA-CD-DOX. Based on these results, we project increased accumulation of drugs in the more acidic (pH 4.5-5.0) microenvironment of cancer cells compared to that of normal healthy cells under physiological pH (7.4). This new FA-CD-DOX NPs could work as efficient theranostic systems to detect and treat cancer.

Der Folsäureantagonist Methotrexat (MTX) wird zur Behandlung onkologischer und rheumatoider Erkrankungen eingesetzt. Die Aufnahme des Methotrexats in die Zielzelle ist dabei Vorraussetzung für die Bindung an seine intrazellulären Zielstrukturen und erfolgt über verschiedene Transportsysteme. In diesem Zusammenhang ist bei entsprechenden Plasma-konzentrationen von MTX der Reduced Folate Carrier (RFC1) von besonderer Bedeutung. 1994 konnte erstmals die cDNA dieses Transporters aus Maus- und Hamstergewebe isoliert werden. Die cDNA für einen mit dem RFC1 identischen hepatozellulären MTX-Transporter der Ratte wurde 2000 kloniert. Vorhergehende Gen-Expressionsstudien zeigten, dass die RFC1-mRNA ubiquitär gebildet wird. Die Proteinexpression wurde jedoch bisher nur in ausgewählten Geweben der Maus untersucht. Systematische Arbeiten, in denen in vergleichender Weise sowohl die RFC1 Gen- als auch die Proteinexpression in allen Geweben mit einer möglichen Relevanz für die Folat- und Antifolataufnahme, Speicherung und Eliminierung untersucht werden, fehlten bisher. Insbesondere die Expression des RFC1-Proteins der Ratte (rRFC1) mittels immunologischer Verfahren ist bisher nicht beschrieben worden. Ziel dieser Arbeit war es daher, die Gen- und Proteinexpression des rRFC1 in ausgewählten Geweben der Ratte darzustellen. Dieses schließt die Generierung spezifischer Antiseren gegen den rRFC1 als ersten Schritt mit ein. Es wurden geeignete antigene Aminosäuresequenzen des rRFC1 bestimmt und die entsprechenden cDNA Sequenzen wurden amplifiziert und in einen geeigneten Expressionsvektor kloniert. Rekombinante rRFC1 Fusionsproteine konnten mittels E. coli Zellen hergestellt und anschließend aufgereinigt werden. Nachfolgend wurden entweder die rRFC1 Fusionsproteine oder die rRFC1 spezifischen Peptide, welche von dem Affinitätspeptid separiert worden waren, für die Immunisierung von Kaninchen verwendet Drei Antiseren mit ausreichender Reaktivität und Spezifität konnten gewonnen und mittels Affinitätschromatographie aufgereinigt werden. Die erhaltenen Antiseren sind gegen die intrazellulären N- und C-terminalen Regionen (ID1, ID7) bzw. gegen die erste extrazelluläre Schleife (OD1) gerichtet. In Western-Blot Studien konnte mittels dieser Antiseren für den rRFC1, der in transfizierten Nierenepithelzellen (MDCK-rRFC-HA) stabil exprimiert wurde, ein Molekulargewicht von 71 kD für die glykosylierte Form und von 53 kD für die unglykosylierte Form ermittelt werden. Weiter konnte belegt werden, dass das Protein in MDCK-rRFC1-HA Zellen überwiegend in der glycosylierten Form vorliegt. Mittels RT-PCR Analysen wurde die Genexpression des rRFC1 in allen untersuchten Geweben nachgewiesen. Besonders hohe mRNA-Gehalte waren in Thymus, Niere und Milz vorhanden, während in Herz- und Muskelgewebe sowie in Leukozyten nur ein Signal nahe der Nachweisgrenze detektierbar war. Durch immunhistologische Untersuchungen konnten die rRFC1 Proteinexpression und beträchtliche Unterschiede in der Signalintensität bestätigt werden. Zusätzlich konnten neue Informationen über die unterschiedliche subzelluläre Lokalisation gewonnen werden: so konnte eine starke Expression des Transporters in der apikalen Membran von Dünn- und Dickdarmmukosa dargestellt werden, während die ebenfalls starke Färbung in der Niere auf den Bereich der basolateralen Membran der Tubuli beschränkt war. In der Leber war eine Expression mittlerer Intensität im Bereich der Lebertrias erkennbar. Während in der Milz nur in der roten Pulpa das RFC1-Protein detektiert wurde, konnten im Thymus sowohl in der Rinde als auch im Mark positive Zellen nachgewiesen werden. Im Hoden konnte der Transporter in den Sertoli-Zellen dargestellt werden. Eine starke Expression des Transporters wurde im Gehirn im Bereich der apikalen Membran der Ependymzellen des Plexus choroideus nachgewiesen. In der Skelettmuskulatur und im Herzgewebe beschränkte sich die Expression des rRFC1 auf das Perimysium des Muskelgewebes und auf kleinere Gefäße des Muskel- und Herzgewebes. In dieser Arbeit konnte somit gezeigt werden, dass der RFC1 der Ratte ubiquitär exprimiert wird, wobei die Expressionsstärke jedoch stark variiert. Die beobachtete Gewebslokalisation des RFC1 belegt sowohl dessen zentrale Rolle in der Folathomöostase als auch in der MTX vermittelten Organtoxizität und Pharmakokinetik, insbesondere bei der intestinalen Resorption sowie der hepatischen und renalen Exkretion.

This thesis is focused on folic acid and its preventive effects on human health. Folic acid has many important functions in the human body and is especially important during pregnancy. It is essential for the proper development of the fetus and its adequate intake is the prevention of serious congenital malformations, such as neural tube defects, premature birth, abortion and other pathologies. The increased need for this vitamin is not easy to supplement with a regular diet. It is therefore recommended to take it in the form of food supplements (400-600 µg/day) during pregnancy and at least one month before the planned conception. For these reasons, it is necessary to focus on supporting the primary prevention of folic acid use, preferably in all fertile women. Folic acid also plays a crucial role in hematopoiesis and the main manifestation of its deficiency is megaloblastic anemia. Folic acid is further associated with the prevention of cardiovascular and cancer diseases and influencing the development of cognitive functions. The practical part of this thesis was focused on monitoring the saturation of pregnant women with this vitamin. The work contains a laboratory analysis of the content of the metabolite folic acid 5-methyltetrahydrofolate (5-MTHF) in the urine of pregnant women in order to...

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