Clinical chemistry
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Clinical Trial Controlled Clinical Trial
Effect of riboflavin status on the homocysteine-lowering effect of folate in relation to the MTHFR (C677T) genotype.
Riboflavin (vitamin B(2)) is the precursor for FAD, the cofactor for methylenetetrahydrofolate reductase (MTHFR). MTHFR catalyzes the formation of 5-methyltetrahydrofolate, which acts as a methyl donor for homocysteine remethylation. Individuals with the MTHFR 677C-->T mutation have increased plasma total homocysteine (tHcy) concentrations, particularly in association with low folate status. It has been proposed that riboflavin may act together with folate to lower plasma tHcy, particularly in individuals with the thermolabile MTHFR T variant. ⋯ Folate and riboflavin interact to lower plasma tHcy, possibly by maximizing the catalytic activity of MTHFR. The effect may be unrelated to MTHFR genotype.
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Comment Clinical Trial
C-reactive protein, interleukin-6, and procalcitonin in the immediate postnatal period: influence of illness severity, risk status, antenatal and perinatal complications, and infection.
Studies of the diagnostic accuracy of most laboratory tests for early-onset neonatal sepsis have yielded variable results. We investigated whether some of this variation might be attributable to differences in population baseline severity and risk status as well as to specific ante- and perinatal variables, independent of the presence of neonatal infection. ⋯ Illness severity and risk status are unlikely to interfere with the use of CRP and PCT for detection of early-onset neonatal sepsis. In contrast, the diagnostic value of IL-6 at birth may be altered by physiologic severity and risk indexes. The reliability of CRP, IL-6, and PCT for the diagnosis of early-onset neonatal infection requires specific cutoff values for each evaluation time point over the first 48 h of life.
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Most pathogenic human mitochondrial DNA (mtDNA) mutations are heteroplasmic (i.e., mutant and wild-type mtDNA coexist in the same individual) and are difficult to detect when their concentration is a small proportion of that of wild-type mtDNA molecules. We describe a simple methodology to detect low proportions of the single base pair heteroplasmic mutation, A3243G, that has been associated with the disease mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) in total DNA extracted from blood. ⋯ This methodology permits easy detection of low concentrations of the MELAS A3243G mutation in blood by standard PCR and sequencing methods.