946 resultados para cyanocobalamin deficiency
Resumo:
DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT
Resumo:
DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT
Resumo:
Despite intense investigation, mechanisms that facilitate the emergence of the pre-eclampsia phenotype in women are still unknown. Placental hypoxia, hypertension, proteinuria and oedema are the principal clinical features of this disease. It is speculated that hypoxia-driven disruption of the angiogenic balance involving vascular endothelial growth factor (VEGF)/placenta-derived growth factor (PLGF) and soluble Fms-like tyrosine kinase-1 (sFLT-1, the soluble form of VEGF receptor 1) might contribute to some of the maternal symptoms of pre-eclampsia. However, pre-eclampsia does not develop in all women with high sFLT-1 or low PLGF levels, and it also occurs in some women with low sFLT-1 and high PLGF levels. Moreover, recent experiments strongly suggest that several soluble factors affecting the vasculature are probably elevated because of placental hypoxia in the pre-eclamptic women, indicating that upstream molecular defect(s) may contribute to pre-eclampsia. Here we show that pregnant mice deficient in catechol-O-methyltransferase (COMT) show a pre-eclampsia-like phenotype resulting from an absence of 2-methoxyoestradiol (2-ME), a natural metabolite of oestradiol that is elevated during the third trimester of normal human pregnancy. 2-ME ameliorates all pre-eclampsia-like features without toxicity in the Comt(-/-) pregnant mice and suppresses placental hypoxia, hypoxia-inducible factor-1alpha expression and sFLT-1 elevation. The levels of COMT and 2-ME are significantly lower in women with severe pre-eclampsia. Our studies identify a genetic mouse model for pre-eclampsia and suggest that 2-ME may have utility as a plasma and urine diagnostic marker for this disease, and may also serve as a therapeutic supplement to prevent or treat this disorder.
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
Placenta growth factor (PlGF) deficient mice are fertile at a Mendelian ratio. Interestingly, low maternal plasma levels of PlGF are strongly associated with early onset of preeclampsia, a pregnancy hypertensive disorder characterised by high blood pressure, proteinuria and fetal growth restriction. PlGF is increasingly being recognised as an early diagnostic biomarker, but the physiological importance of PlGF in the pathogenesis of preeclampsia is unknown. We investigated whether the decreased levels of PlGF in pregnancy exacerbate the fetal growth restriction associated with preeclampsia in the presence of high sFlt-1 and the potential of hydrogen sulphide to ameliorate these effects. Pregnant PlGF−/− mice were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) at 1 × 109 pfu/ml at E10.5 and mean arterial blood pressure (MAP), biochemical and histological analysis of maternal kidney, placenta and embryos were assessed at the end of pregnancy. Ad-sFlt-1 significantly increased MAP and induced severe glomerular endotheliosis in PlGF−/− mice compared to wild-type animals. Soluble Flt-1 also significantly elevated albumin–creatinine ratio and increased levels of urinary kidney injury molecule-1, a marker for proximal tubule injury. Furthermore, sFlt-1 over expression increased fetal resorption rate in the PlGF−/− mice and promoted abnormal placental vascularisation. To determine whether placental PlGF is critical for preventing fetal growth restriction associated with preeclampsia, we generated haploinsufficient PlGF+/− placentas and embryos in dams and exposed to high sFlt-1 environment. These mothers showed reduced fetal resorption, gestational hypertension and proteinuria when compared to pregnant PlGF−/− mice. Furthermore, treatment with hydrogen sulphide-releasing agent, GYY4137, significantly reduced resorption, hypertension and proteinuria observed in Ad-sFlt-1 treated pregnant PlGF−/− mice. Our study shows that placental PlGF is a critical protective factor against the damaging effects of high sFlt-1 associated with preeclampsia and activation of the hydrogen sulphide pathway may rescue preeclampsia phenotypes even under low PlGF environment.
Resumo:
INTRODUCTION: Low circulating levels of placenta growth factor (PlGF) is strongly associated with the onset of preeclampsia, a maternal hypertensive disorder characterized by high blood pressure and proteinuria after 20 weeks of gestation. Although, PlGF-deficient mice are born healthy and fertile at a Mendelian ratio, the physiological importance of PlGF in the pathogenesis of preeclampsia is unclear. We hypothesised that decreased levels of PlGF in pregnancy exacerbates the fetal growth restriction associated with preeclampsia in the presence of high sFlt-1. METHODS: Pregnant PlGF-/- mice were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) at high (i) 1.5x109 pfu/ml and low (ii) 0.5x109 pfu/ml doses. Mean arterial blood pressure (MBP), biochemical and histological assessments of maternal kidney, placenta and embryos were performed. RESULTS: Ad-sFlt-1 significantly increased MBP and induced severe glomerular endotheliosis in PlGF-/- mice at E10.5 gestation compared to wild-type animals. High sFlt-1 also significantly elevated albumincreatinine ratio and increased levels of urinary kidney injury molecule-1, a marker for proximal tubule injury.At a high dose of sFlt-1, there was complete fetal resorption in the pregnant PlGF-/- mice, and even the lower dose of sFlt-1 induced severe fetal resorption and abnormal placental vascularization. Hydrogen sulphide-releasing agent, GYY4137, significantly reduced resorption, hypertension and proteinuria in Ad-sFlt-1 treated pregnant PlGF-/- mice. To determine if placental PlGF is critical for preventing fetal growth restriction associated with preeclampsia, we generated haploinsufficient PlGF+/- placentas and embryos were generated in wild-time dams and exposed to high sFlt-1 environment. This resulted in reduced fetal resorption, gestational hypertension and proteinuria when compared to pregnant PlGF-/- mice. CONCLUSIONS: Placental PlGF is a critical protective factor against the damaging effects of high sFlt-1 in preeclampsia and the hydrogen sulphide pathway may rescue preeclampsia phenotypes.
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
Introduction: Vitamin D deficiency during pregnancy is a public health problem and it has been associated with negative pregnancy outcomes for both mothers and infants. Aim: To estimate the prevalence of vitamin D deficiency in pregnant women in the United Arab Emirates (UAE) and to identify the contribution of risk factors to the 25(OH)D levels. Methods: It is a cross-sectional study in which vitamin D levels of 1088 adult pregnant women were assessed. Information on vitamin D intake was available in a sub-sample of 266 women. Results: The mean serum 25(OH)D was 26.2 nmol/L (95% CI 25.2-27.1 range 5-129.1 nmol/L) with 69% of women being vitamin D deficient (<30 nmol/L). In the bivariate analysis, showed that no predictors could have been indicated as no values exceeded significance (p<0.2). Stepwise multiple linear regression analysis could not be applied to identify predictors of vitamin D levels as no values exceeded p=0.2. Conclusion: Due to the high prevalence of vitamin deficiency in UAE, there is an urge for interventions focusing on supplementation, fortification and diet diversity for preventing health consequences during a critical period of development.
Resumo:
During their life cycle, plants are typically confronted by simultaneous biotic and abiotic stresses. Low inorganic phosphate (Pi) is one of the most common nutrient deficiencies limiting plant growth in natural and agricultural ecosystems, while insect herbivory accounts for major losses in plant productivity and impacts ecological and evolutionary changes in plant populations. Here, we report that plants experiencing Pi deficiency induce the jasmonic acid (JA) pathway and enhance their defense against insect herbivory. Pi-deficient Arabidopsis (Arabidopsis thaliana) showed enhanced synthesis of JA and the bioactive conjugate JA-isoleucine, as well as activation of the JA signaling pathway, in both shoots and roots of wild-type plants and in shoots of the Pi-deficient mutant pho1 The kinetics of the induction of the JA signaling pathway by Pi deficiency was influenced by PHOSPHATE STARVATION RESPONSE1, the main transcription factor regulating the expression of Pi starvation-induced genes. Phenotypes of the pho1 mutant typically associated with Pi deficiency, such as high shoot anthocyanin levels and poor shoot growth, were significantly attenuated by blocking the JA biosynthesis or signaling pathway. Wounded pho1 leaves hyperaccumulated JA/JA-isoleucine in comparison with the wild type. The pho1 mutant also showed an increased resistance against the generalist herbivore Spodoptera littoralis that was attenuated in JA biosynthesis and signaling mutants. Pi deficiency also triggered increased resistance to S. littoralis in wild-type Arabidopsis as well as tomato (Solanum lycopersicum) and Nicotiana benthamiana, revealing that the link between Pi deficiency and enhanced herbivory resistance is conserved in a diversity of plants, including crops.
Resumo:
Lymphatic porosity was produced by feeding rats a diet, lacking from the vitamins of the B group. Coumarintroxerutin (Venalot®) treatment has been found to prevent this abnormality. Pathophysiologic and therapeutic implications of these findings are discussed. © 1973 S. Karger AG, Basel.
Resumo:
Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by defects in one of several steroidogenic enzymes involved in the synthesis of cortisol from cholesterol in the adrenal glands. More than 90% of cases are caused by 21-hydroxylase deficiency, and the severity of the resulting clinical symptoms varies according to the level of 21-hydroxylase activity. 21-Hydroxylase deficiency is usually caused by mutations in the CYP21A2 gene, which is located on the RCCX module, a chromosomal region highly prone to genetic recombination events that can result in a wide variety of complex rearrangements, such as gene duplications, gross deletions and gene conversions of variable extensions. Molecular genotyping of CYP21A2 and the RCCX module has proved useful for a more accurate diagnosis of the disease, and prenatal diagnosis. This article summarises the clinical features of 21-hydroxylase deficiency, explains current understanding of the disease at the molecular level, and highlights recent developments, particularly in diagnosis.
Resumo:
Scurvy was a common 18th century disease caused by vitamin C deficiency. It presents with multiple non-specific symptoms and can lead to capillary fragility due to impaired collagen synthesis. We report the case of a 63-year-old woman who presented with fatigue, nausea and progressive skin lesions consisting of multiple ecchymoses on the legs as also described in the diary drawings of a navy doctor in the 19th century. The ascorbic acid level was undetectable low in the patient’s serum. However, treatment with 500 mg ascorbic acid daily dramatically improved the skin lesions within 5 days.
Resumo:
We report a case of a 64-year-old male who, 44 days after starting treatment with prasugrel, presented with severe thrombocytopenia, anemia, renal failure, and severe ADAMTS13 activity deficiency, along with a high titer of autoantibodies to this protease.
Resumo:
Background: Between 1961-1971 vitamin D deficiency was recognized as a public health issue in the UK, because of the lack of effective sunlight and the population mix [1, 2]. In recent years, health care professionals have cited evidence suggesting a re-emergence of the vitamin D deficiency linked to a number of health consequences as a concern [3-6]. Evidence from observational studies has linked low vitamin D status with impairment in glucose homeostasis and immune dysfunction [7-9]. However, interventional studies, particularly those focused on paediatric populations, have been limited and inconsistent. There is a need for detailed studies, to clarify the therapeutic benefits of vitamin D in these important clinical areas. Objective: The aims of this PhD thesis were two-fold. Firstly, to perform preliminary work assessing the association between vitamin D deficiency and bone status, glucose homeostasis and immune function, and to explore any changes in these parameters following short term vitamin D3 replacement therapy. Secondly, to assess the effectiveness of an electronic surveillance system (ScotPSU) as a tool to determine the current incidence of hospital-based presentation of childhood vitamin D deficiency in Scotland. Methods: Active surveillance was performed for a period of two years as a part of an electronic web-based surveillance programme performed by the Scottish Paediatric Surveillance Unit (ScotPSU). The validity of the system was assessed by identifying cases with profound vitamin D deficiency (in Glasgow and Edinburgh) from the regional laboratory. All clinical details were checked against those identified using the surveillance system. Thirty-seven children aged 3 months to 10 years, who had been diagnosed with vitamin D deficiency, were recruited for the bone, glucose and immunity studies over a period of 24 months. Twenty-five samples were analysed for the glucose and bone studies; of these, 18 samples were further analysed for immune study. Treatment consisted of six weeks taking 5000 IU units cholecalciferol orally once a day. At baseline and after completion of treatment, 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), collagen type 1 cross-linked C-telopeptide (CTX), osteocalcin (OCN), calcium, phosphate, insulin, glucose, homeostasis model assessment index, estimated insulin resistance (HOMA IR), glycated hemoglobin (HbA1c), sex hormone binding globulin (SHBG), lipids profiles, T helper 1 (Th1) cytokines (interleukin-2 ( IL-2), tumor necrosis factors-alpha (TNF-α), interferon-gamma (INF-γ)), T helper 2 (Th2) cytokines (interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6)), T helper 17 (Th17) cytokine (interleukin-17 (IL-17)), Regulatory T (Treg) cytokine (interleukin-10 (IL-10)) and chemokines/cytokines, linked with Th1/Th2 subset balance and/or differentiation (interleukin-8 (IL-8), interleukin-12 (IL-12), eosinophil chemotactic protein ( EOTAXIN), macrophage inflammatory proteins-1beta (MIP-1β), interferon-gamma-induced protein-10 (IP-10), regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein-1(MCP-1)) were measured. Leukoocyte subset analysis was performed for T cells, B cells and T regulatory cells and a luminex assay was used to measure the cytokiens. Results: Between September 2009 and August 2011, 163 cases of vitamin D deficiency were brought to the attention of the ScotPSU, and the majority of cases (n = 82) were reported in Glasgow. The cross-validation checking in Glasgow and Edinburgh over a one-year period revealed only 3 (11%) cases of clearly symptomatic vitamin D deficiency, which had been missed by the ScotPSU survey in Glasgow. While 16 (67%) symptomatic cases had failed to be reported through the ScotPSU survey in Edinburgh. For the 23 children who are included in bone and glucose studies, 22 (96%) children had basal serum 25(OH)D in the deficiency range (< 50 nmol/l) and one (4%) child had serum 25(OH)D in the insufficiency range (51-75 nmol/l). Following vitamin D3 treatment, 2 (9%) children had final serum 25(OH)D lower than 50 nmol/l, 6 (26%) children had final serum 25(OH)D between >50-75 nmol/l, 12 (52%) children reached a final serum 25(OH)D >75-150 nmol/l and finally 3 (13%) exceeded the normal reference range with a final 25(OH)D >150 nmol/l. Markers for remodelling ALP and PTH had significantly decreased (p = 0.001 and <0.0001 for ALP and PTH respectively). In 17 patients for whom insulin and HOMA IR data were available and enrolled in glucose study, significant improvements in insulin resistance (p = 0.04) with a trend toward a reduction in serum insulin (p = 0.05) was observed. Of those 14 children who had their cytokines profile data analysed and enrolled in the immunity study, insulin and HOMA IR data were missed in one child. A significant increase in the main Th2 secreted cytokine IL-4 (p = 0.001) and a tendency for significant increases in other Th2 secreted cytokines IL-5 (p = 0.05) and IL-6 (p = 0.05) was observed following vitamin D3 supplementation. Conclusion: An electronic surveillance system can provide data for studying the epidemiology of vitamin D deficiency. However, it may underestimate the number of positive cases. Improving vitamin D status in vitamin D deficient otherwise healthy children significantly improved their vitamin D deficient status, and was associated with an improvement in bone profile, improvements in insulin resistance and an alteration in main Th2 secreting cytokines.