Publications by authors named "Blom H"

S-adenosylmethionine (SAM)-dependent methylation of biological molecules including DNA and proteins is rapidly being uncovered as a critical mechanism for regulation of cellular processes. We investigated the effects of reduced SAM-dependent methylation on osteoblast differentiation by using periodate oxidized adenosine (ADOX), an inhibitor of SAM-dependent methyltransferases. The capacity of this agent to modulate osteoblast differentiation was analyzed under non-osteogenic control conditions and during growth factor-induced differentiation and compared with the effect of inhibition of DNA methylation by 5-Aza-2'-deoxycytidine (5-Aza-CdR).

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Evidence exists for an association between use of vitamin supplements with folic acid in early pregnancy and reduced risk for offspring with cleft lip with/without cleft palate (CLP). A few observations have been made about nutrients related to one-carbon metabolism other than folate. Our prospective study attempted to extend information on nutrition and CLP by measuring nutrient analytes in mid-pregnancy sera.

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A method for determination of the plasmid DNA concentration with subsequent analysis of the ratio supercoiled to open circular form is presented. The method is suitable for samples from all steps of the manufacturing process, from fermentation to final product. The analysis consists of size exclusion chromatography, followed by analytical thiophilic aromatic chromatography.

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An unassigned and prominent resonance in the region from delta 2.0-2.1 ppm has frequently been found in the in vivo MR spectra of cancer patients.

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Background: Folic acid is known to reduce risk of neural tube defects (NTDs). Even so, NTDs continue to occur despite individual supplementation or population fortification with folic acid. We investigated other nutrients related to one-carbon metabolism that may affect NTD risk.

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Hyperhomocysteinemia and factors of homocysteine metabolism, S-adenosylhomocysteine (AdoHcy) and S-adenosylmethionine (AdoMet), may play a role in Alzheimer's disease (AD). With liquid-chromatography-tandem-mass-spectrometry AdoMet and AdoHcy were determined in brains of 8- and 15-month-old APP/PS1 Alzheimer mice, and their possible roles in AD brains investigated. The finding that AdoMet levels do not differ between the genotypes in (young) 8-month-old mice, but are different in (older) 15-month-old APP/PS1 mice compared to their wild-type littermates, suggests that alterations in AdoMet are a consequence of AD pathology rather than a cause.

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Clostridium difficile infection (CDI) has become more refractory to standard therapy. We describe 4 patients with severe refractory CDI who were successfully treated with tigecycline. Symptoms improved within 1 week.

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Betaine therapy was given for 2 years to a 2-year-old boy with 5,10-methylenetetrahydrofolate reductase deficiency. Used as a methyl donor to lower homocysteine levels through methylation of methionine, betaine has been reported to be effective in treating homocystinuria. Satisfactory biochemical and clinical responses were obtained with the following regimen: betaine started in the newborn period at increasing doses to reach 1 g given six times a day.

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The triplet-state kinetics of several fluorescent dyes used in ultrasensitive fluorescence microscopy are investigated using total internal reflection fluorescence correlation spectroscopy (TIR-FCS). A theoretical outline of the correlation analysis and the physical aspects of evanescent excitation and fluorescence emission at dielectric interfaces are given. From this analysis, the rates of intersystem crossing and triplet decay are deduced for fluorescein, ATTO 488, rhodamine 110, rhodamine 123, and rhodamine 6G in aqueous buffer solutions.

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Objective: Axonal degeneration is the likely cause of disease progression in multiple sclerosis (MS). Our previous results indicated that neuron-specific N-acetylaspartate (NAA) is a candidate CSF biomarker for disease progression in MS. The aim of this study was to explore the potential of NAA as an early biomarker of axonal damage in MS.

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The risk of nutrient deficiencies increases with age in our modern Western society, and vitamin B(12) deficiency is especially prevalent in the elderly and causes increased homocysteine (Hcy) and methylmalonic acid (MMA) levels. These three factors have been recognized as risk factors for reduced bone mineral density and increased fracture risk, though mechanistic evidence is still lacking. In the present study, we investigated the influence of B(12), Hcy, and MMA on differentiation and activity of bone cells.

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Objective: The WHO describes violence as a global public health problem. In contrast to domestic violence, violence against youth has been little explored. Our aims were to investigate the prevalence and gender differences in relation to emotional, physical and sexual abuse among young men and women attending youth health centers in Sweden, the current adverse effects of the abuse and the perpetrators of the abuse.

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Objective: Patients with inflammatory bowel disease (IBD) often have low iron stores or anaemia. There is controversy about whether iron should be supplemented orally or intravenously (i.v.

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Folic acid, methylation and neural tube closure in humans.

Birth Defects Res A Clin Mol Teratol

April 2009

This review provides a brief description of folate use and folic acid metabolism in relation to neural tube defect (NTD) risk. First, a meta-analysis of reduction in NTD recurrence and occurrence risk with periconceptional folic acid supplementation is presented. Second, an overview of the complex folate metabolism is given.

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Background: Spina bifida is a class of neural tube defects, which are congenital malformations of the central nervous system with a prevalence of 0.5 to 12 per 1000 births globally. In this article we attempt to identify genes related to folate and its metabolic pathways that are involved in the etiology of spina bifida.

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We report an effective method to fabricate two-dimensional (2D) periodic oxide nanopatterns using S-layer proteins as a template. Specifically, S-layer proteins with a unit cell dimension of 20 nm were reassembled on silicon substrate to form 2D arrays with ordered pores of nearly identical sizes (9 nm). Octadecyltrichlorosilane (ODTS) was utilized to selectively react with the S-layer proteins, but not the Si surface exposed through the pores defined by the proteins.

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Previously, we presented evidence that mucins have potential as biomaterial coatings. Here, we reveal substantial batch-to-batch variations for a frequently used commercial bovine salivary mucin preparation (BSM) and stress the importance of standardizing mucins intended for comparative purposes. "Mild" fractionation strategies, aiming at preserving natural mucin functions, were used to prepare two more defined BSM fractions as well as three mucin fractions from porcine gastric (PGM) and human salivary (MG1) sources.

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Objective: Past studies of cigarette smoking as a contributor to orofacial clefts and neural tube defects (NTDs) used self-reports of smoke exposures. We have correlated measurements of cotinine (a nicotine metabolite) in mid-pregnancy sera with clefts and NTDs.

Study Design: From a repository of >180 000 mid-pregnancy serum specimens collected in California from 2003 to 2005 and linked to delivery outcome information, we identified 89 orofacial cleft-associated pregnancies, 80 NTD-affected pregnancies, and randomly selected 409 pregnancy specimens that corresponded to infants without malformations as control subjects.

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Background: An impaired DNA methylation has been suggested to underlie the complex etiology of neural tube defects (NTDs). Previously, we have demonstrated that inhibition of methylation by periodate oxidized adenosine (Adox) results in a widening of the anterior neuropore (ANP) in our in vitro chick embryo model. Since DNA methylation is the chief regulator of gene expression, we hypothesize that inhibition of methylation by Adox in our in vitro chick embryo model will affect the expression of genes that may be involved in neurulation.

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Background: Sepsis is a disease with high incidence and lethality and is accompanied by profound metabolic disturbances. In mammalian methionine metabolism, S-adenosylmethionine (SAM) is produced, which is important in the synthesis of neurotransmitters and glutathione and as an anti-inflammatory agent. The degradation product and antagonist of SAM is S-adenosylhomocysteine (SAH).

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Background: Endothelial nitric oxide synthase (eNOS) produces nitric oxide, which plays a role in vasodilatation and in the regulation of cell growth and apoptosis. eNOS-deficient mice have impaired cardiac development resulting in congenital heart defects (CHDs). In humans, a single nucleotide polymorphism in the gene coding for eNOS (894G>T) is associated with birth defects.

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Background: Hyperhomocysteinemia has been associated with an increased risk of venous thrombosis, which might be mediated through an oxidative stress dependent mechanism. The function of uncoupling protein-2 (UCP2) is still under debate, but it has been suggested to play a role in reduction of mitochondrial reactive oxygen species. In the present study, we investigated whether the 45 bp deletion/insertion (del/ ins) polymorphism in the UCP2 gene is associated with elevated homocysteine levels and whether it might be associated with an increased risk of recurrent venous thrombosis (RVT).

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