Methods in molecular biology
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Methylation of cytosines is a very important epigenetic modification of genomic DNA in many different eukaryotes, and it is frequently involved in transcriptional regulation of genes. In plants, DNA methylation is regulated by a complex interplay between several methylating and demethylating enzymes. ⋯ Subsequent PCR and sequence analysis of individual amplicons displays the degree, position, and sequence context of methylation of every cytosine residue in individual genomic sequences. We describe the application of bisulfite sequencing for the analysis of DNA methylation at defined individual sequences of plant genomic DNA.
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The principles of fluorescence resonance energy transfer have been utilized to develop a high-throughput assay which detects compounds that interfere with interaction between retinol-binding protein (RBP) and transthyretin (TTR). In this assay, the intrinsic fluorescence from the RBP-retinol complex excites a probe molecule which is covalently coupled to TTR. ⋯ Thus, compounds which bind to RBP must compete with retinol in order to affect RBP-TTR interaction. This feature of the assay will be useful to identify test compounds which are more likely to have an effect in vivo.
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The study of procedural sedation and analgesia has experienced significant development recently. As specific procedural sedation and analgesia agents have been developed and introduced into clinical practice, safety and efficacy studies have been conducted. ⋯ As procedural sedation and analgesia research has expanded, measurement techniques have been refined to allow for precise comparisons between smaller groups of subjects to improve the capacity to compare these procedures. We have used capnography, bispectral EEG analysis, and subject perceptions of pain and recall as surrogate predictors of adverse events in order to compare agents and procedural techniques in procedural sedation and analgesia.
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The specific causes of prostate cancer are not known. However, multiple etiologic factors, including genetic profile, metabolism of steroid hormones, nutrition, chronic inflammation, family history of prostate cancer, and environmental exposures are thought to play significant roles. Variations in exposure to these risk factors may explain interindividual differences in prostate cancer risk. ⋯ Numerous single nucleotide polymorphisms (SNPs) in DNA repair genes have been found, and studies of these SNPs and prostate cancer risk are critical to understanding the response of prostate cells to DNA damage. A few SNPs in DNA repair genes are associated with significantly increased risk of prostate cancer; however, in most cases, the effects are moderate and often depend upon interactions among the risk alleles of several genes in a pathway or with other environmental risk factors. This report reviews the published epidemiologic literature on the association of SNPs in genes involved in DNA repair pathways and prostate cancer risk.
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Magnetoencephalography (MEG) encompasses a family of non-contact, non-invasive techniques for detecting the magnetic field generated by the electrical activity of the brain, for analyzing this MEG signal and for using the results to study brain function. The overall purpose of MEG is to extract estimates of the spatiotemporal patterns of electrical activity in the brain from the measured magnetic field outside the head. The electrical activity in the brain is a manifestation of collective neuronal activity and, to a large extent, the currency of brain function. The estimates of brain activity derived from MEG can therefore be used to study mechanisms and processes that support normal brain function in humans and help us understand why, when and how they fail.