Expression of multidrug resistance 1 gene and C3435T genetic polymorphism in peripheral blood of patients with intractable epilepsy

BACKGROUND： Increased expression of multidrug resistance 1 （MDR1） mRNA in peripheral blood of patients with intractable epilepsy is not due to epilepsy drugs, but epilepsy behavior. Monitoring MDR1 expression in peripheral blood is a target for MDR1 gene evaluation. OBJECTIVE： To investigate the influence of antiepileptic drugs and seizures on MDR expression in intractable epilepsy, and to analyze the genetic polymorphisms of C3435T in the MDRl gene. DESIGN, TIME AND SETTING： Factorial designs and comparative observations at the experimental center of the Affiliated Hospital of Qingdao Medical College, Qingdao University between October 2003 and October 2004. PARTICIPANTS： A total of 120 subjects were recruited from the epilepsy clinical department of the Affiliated Hospital of Qingdao Medical College. Four groups （n = 30） were classified according to statistical factorial design： intractable epilepsy, treatment response, no treatment, and normal control groups. METHODS： One-step semi-quantitative reverse-transcription polymerase chain reaction technology was used to test expressions of the MDR1 gene in 120 subjects. C3435T polymorphisms in intractable epilepsy group and normal control groups were analyzed by polymerase chain reaction-restriction fragment length polymorphism. MAIN OUTCOME MEASURES： Expression of MDR1 mRNA in the four groups, and C3435T genetic polymorphisms in intractable epilepsy and normal control groups. RESULTS： MDRl gene expression was increased in the intractable epilepsy group, due to the factor seizures, but not the antiepileptic drugs. However, the interaction between the two factors was not statistically significant. Of the 30 subjects in the intractable epilepsy group, the following genotypes were exhibited： 3 （10%） C/C genotype, 9 （30%） C/T genotype, and 18 （60%） T/T genotype at the site of C3435T, while 4 （13%）, 10 （33%）, and 16 （53%） subjects were determined to express these genotypes in the normal control group, respectively. C and T allele frequency were 25% and 75% in the intractable epilepsy group, and 30% and 70% in the normal control group, respectively. However, there was no statistical difference between the groups. CONCLUSION： Results demonstrated that seizures, not antiepileptic drugs, induced MDR1 gene expression in intractable epilepsy. Genetic polymorphisms of C3435T in the MDR1 gene did not contribute to the development of multidrug resistance in patients with intractable epilepsy.

Study of Alkali Metal Corrosion on Heating Surfaces and Bed Material Agglomerate in Biomass-fired Fluidized Bed Boiler

The bed material agglomeration and heating surface high-temperature Corrosion Problems of biomass-fired boiler in South China were studied in this work. The inner and outer surfaces of the corrosion sample were investigated by scanning electron microscope (SEM) with Bruker EDX and XRD. Results showed that the outer side of the corrosion sample was mainly composed of alkali chloride deposited ash, sulphide and a small amount of eutectoid;while the inner side of the corrosion sample was still mainly made up of the composition of SUS316, but added with alkali metal, oxygen, chlorine and sulphur elements, appearing as the corrosion products and eutectoid. It was thought that alkali chloride deposit and the reaction with pipe metal to generate low melting point eutectoid on the outer surfaces, or the corrosion reaction through the alkali metal sulphatization process was the main reasons leading to the damage of metal surface oxide film. Chlorine plays a role as haptoreaction in the corrosion process, and transports metal material as the form of chloride from the inner side to the outer side of the pipe surfaces by diffusion, accelerating the corrosion process. Meanwhile, the slag was studied by scanning electron microscope (SEM) with Bruker EDX, and the transformation process of slage was computationally analyzed by FACTSAGE. Results showed that the amount of alkali metal in the agglomerates was little, however, caused a great impact on severe agglomerates. The increase of temperature enhanced the conversion process of alkali metal to molten oxide, especially when the temperature was higher than760℃, the amount of molten product increased sharply. Thus, the temperature control of fluidized bed plays an important role in solving the problem of alkali metal agglomerates;it also reliefs the volatile of alkali metal into gas phase, benefiting the control of heating surface corrosion.

Mapping the epigenetic modifications of DNA and RNA

Over 17 and 160 types of chemical modifications have been identified in DNA and RNA,respectively.The interest in understanding the various biological functions of DNA and RNA modifications has lead to the cutting-edged fields of epigenomics and epitranscriptomics.Developing chemical and biological tools to detect specific modifications in the genome or transcriptome has greatly facilitated their study.Here,we review the recent technological advances in this rapidly evolving field.We focus on high-throughput detection methods and biological findings for these modifications,and discuss questions to be addressed as well.We also summarize third-generation sequencing methods,which enable long-read and single-molecule sequencing of DNA and RNA modification.

Genome-wide Mapping of Cellular Protein–RNA Interactions Enabled by Chemical Crosslinking

RNA–protein interactions influence many biological processes. Identifying the binding sites of RNA-binding proteins（RBPs） remains one of the most fundamental and important challenges to the studies of such interactions. Capturing RNA and RBPs via chemical crosslinking allows stringent purification procedures that significantly remove the non-specific RNA and protein interactions. Two major types of chemical crosslinking strategies have been developed to date, i.e., UV-enabled crosslinking and enzymatic mechanism-based covalent capture. In this review, we compare such strategies and their current applications, with an emphasis on the technologies themselves rather than the biology that has been revealed. We hope such methods could benefit broader audience and also urge for the development of new methods to study RNA RBP interactions.