Research on methylation of FHIT,hMLH1,p16,RAR-beta,Reprimo and TIMP3 genes in gastric cancer patients / 实用肿瘤学杂志

Objective The aim of this study was to investigate the methylation status of fragile histidine triad( FHIT) gene, human mutl homolog 1(hMLH1)gene,p16 gene,retinoic acid receptor beta( RAR-beta) gene,Reprimo gene and tissue inhibitor of metalloproteinase 3 ( Timp3) gene in gastric cancer and corresponding paracancerous tissues. Methods The methylation levels of FHIT,hMLH1,p16,RAR-beta,Reprimo and TIMP3 genes in 42 clinically resected gastric cancer specimens and 42 corresponding paracancerous tissues were detected by sodium bisulfite sequencing. Results The average methylation rates of the genes in gastric cancer and corresponding paracancerous tissues were:FHIT(1. 50% ,1. 36% ),hMLH1(4. 77% ,0. 48% ),p16(9. 63% ,10. 36% ), RAR-beta(4. 75% ,4. 17% ),Reprimo(9. 71% ,3. 76% )and TIMP3 genes(18. 34% ,14. 06% ). Compared with the paracancerous control group,the average methylation rate of Reprimo gene was only statistically different in gastric cancer patients(P=0. 00787). The difference in methylation rate of Reprimo gene promoter in gastric cancer patients with the degree of tissue differentiation was sta-tistically significant(P<0. 05). Conclusion There has methylation in the cytosine guanidine dinucleotide island of the Reprimo gene promoter region in gastric cancer. The high methylation rate of the Reprimo gene can be used as a potential biomarker for gastric cancer to detect the early stage of gastric cancer.

Relationship between methylation of SOX11 gene and cervical cancer / 西安交通大学学报(医学版)

Objective: To detect the methylation status of SOX11 gene in normal cervix, cervical cancer tissues and cervical cancer cell lines so as to explore the relationship between methylation status and expression of SOX11 gene. Methods: DNA methylation status of SOX11 gene in normal cervical, cervical cancer tissues and cervical cancer cell lines was analyzed by bisulfite sequencing and TA cloning assay. The expression of SOX11 mRNA in cervical cancer tissues, cell lines and normal cervical was detected by RT-PCR. Results: The average methylation rate of SOX11 in cervical cancer tissues (81.07%) was significantly higher than that in normal cervical tissues (12.86%) (P<0.001). The methylation status of SOX11 in HeLa, SiHa, C33-A and CaSki cells was all hypermethylated with the methylation of 90.71%, 97.14%, 77.14% and 99.64%, respectively. The expression of SOX11 mRNA in cervical cancer tissues was significantly lower than that in normal cervixes (P<0.001). The SOX11 gene expression was significantly negatively correlated with its promoter hypermethylation (P<0.001, r=-0.808). After demethylation agent 5-azacytidine treatment, SOX11 mRNA expression in cervical cancer cell lines was significantly increased. Further analysis showed that HPV infection in cervical cancer might increase SOX11 promotor methylation. Conclusion: SOX11 gene in cervical cancer is silenced by the hypermethylation of DNA in the promoter region.

HeteroMeth: A Database of Cell-to-cell Heterogeneity in DNA Methylation / 基因组蛋白质组与生物信息学报·英文版

DNA methylation is an important epigenetic mark that plays a vital role in gene expression and cell differentiation. The average DNA methylation level among a group of cells has been extensively documented. However, the cell-to-cell heterogeneity in DNA methylation, which reflects the differentiation of epigenetic status among cells, remains less investigated. Here we established a gold standard of the cell-to-cell heterogeneity in DNA methylation based on single-cell bisulfite sequencing (BS-seq) data. With that, we optimized a computational pipeline for estimating the heterogeneity in DNA methylation from bulk BS-seq data. We further built HeteroMeth, a database for searching, browsing, visualizing, and downloading the data for heterogeneity in DNA methylation for a total of 141 samples in humans, mice, Arabidopsis, and rice. Three genes are used as examples to illustrate the power of HeteroMeth in the identification of unique features in DNA methylation. The optimization of the computational strategy and the construction of the database in this study complement the recent experimental attempts on single-cell DNA methylomes and will facilitate the understanding of epigenetic mechanisms underlying cell differentiation and embryonic development. HeteroMeth is publicly available at http://qianlab.genetics.ac.cn/HeteroMeth.

Expression of interleukin-6 in hippocampus of rat with febrile seizures and the effect of valproic acid administration on its methylation level / 中华行为医学与脑科学杂志

Objective@#To investigate the level of interleukin-6 (IL-6) and the effect of valproic acid(VPA) administration on IL-6 promoter methylation, further to explore the epigenetic mechanism in febrile seizures.@*Methods@#Sprague-Dawley (SD) rats (21 day) were randomly divided into control group (n=12) and febrile seizure (FS) group (n=12), and seizures were generated using hot bath methods and evaluated by racine score and electroencephalogram (EEG). The IL-6 protein and mRNA levels were detected using ELISA and quantitative reverse transcription polymerase chain reaction (qRT-PCR), respectively.Rat C6 cell line was cultured and randomly divided into control, VPA(0.2 mol/L), hyperthermia(43.5 ℃, 1 h), hyperthermia (43.5 ℃, 1 h)+VPA (0.2 mol/L) groups.The methylation status of IL-6 promoter in FS rats and the effect of VPA on IL-6 methylation in C6 cell line were examined by bisulfite sequencing polymerase chain reaction (BSP) to determine the epigenetic regulation of IL-6 level in FS.@*Results@#Racine score and EEG results showed that the frequency and amplitude of neuronal discharge increased after hot water bath in rats, and the latency of convulsion was shorter.The expression levels of IL-6 mRNA and protein were significantly increased in Fs group compared with those in control group(mRNA: Control: 0.98±0.34; FS: 2.85±0.39, P<0.05; Protein: Control: (2 824.33±169.20)pg/ml; FS: (3 514.58±86.4)pg/ml, P<0.01). The methylation of IL-6 promoter in FS group (84% (21/25)) was lower than that in control group (100% (25/25)) (P<0.05). A significant increase in methylation of IL-6 promoter was observed in C6 cell line from VPA combined with hyperthermia (96% (24/25)) but no change was showed in that from VPA alone (100% (25/25)) compared with that from control(100% (25/25)).@*Conclusion@#IL-6 level is up-regulated in FS rats, and the hypomethylation or demethylation of the IL-6 promoter region might increase the IL-6 level.VPA administration can elevate its methylation level, which provides a strong experimental basis for the future study of the epigenetic mechanism in FS.

A influência de polimorfismos de base única na metilação de DNA em genes de receptores olfatórios / Single nucleotide polymorphisms lead to differential DNA methylation in odorant receptor genes

Os genes de receptores olfatórios (OR) pertencem a uma família de proteínas de membrana formada por cerca de 1000 genes no genoma de camundongo. Os genes OR são expressos de forma monogênica e monoalélica nos neurônios olfatórios (OSNs). No entanto, ainda não está claro o mecanismo que permite essa forma de expressão peculiar, sobretudo, qual o papel da metilação de DNA nesse processo. Nosso estudo determinou o padrão de metilação de DNA da região promotora e codificadora do gene Olfr17. Em células de epitélio olfatório (MOE) de camundongos adultos, observamos na região codificadora (CDS) do gene uma frequência de metilação em dinucleotídeos CpG 58%, enquanto que na sua região promotora ela foi bem mais baixa. Os níveis de metilação do Olfr17 em MOE de embrião (E15.5) e fígado foram similares aos observados em MOE de animais adultos. Em seguida, analisamos se a metilação de DNA pode regular a expressão gênica do Olfr17. Utilizando animais transgênicos onde os neurônios olfatórios que expressam Olfr17 também expressam GFP, pudemos selecionar neurônios olfatórios GFP+ e analisar a metilação do gene Olfr17, que está ativo nestas células. Verificamos que o padrão geral de metilação do Olfr17, tanto na região CDS como na região promotora, não se altera quando este gene está ativo. Este resultado indica que alterações na metilação do gene Olfr17 não são necessárias para que este receptor seja expresso. Finalmente, verificamos que a região promotora do gene Olfr17, de duas linhagens de camundongos diferentes, a C57BL/6 e a 129, possuem dois polimorfismos de base única (SNPs) que alteram o conteúdo CpG. Devido a estes SNPs, a linhagem 129 apresenta dois sítios CpG adicionais, inexistentes na linhagem C57BL/6. Nossas análises mostraram que estes CpGs são frequentemente metilados, o que torna o promotor do Olfr17 de 129 significativamente mais metilado que o promotor de C57BL/6. Em seguida, nós analisamos o nível de expressão no MOE dos dois alelos de Olfr17, o 129 e o C57BL/6, utilizando ensaios de RT-qPCR. Estes experimentos demonstraram que o nível de expressão do alelo 129, que possui 3 CpGs metiladas em seu promotor, é menor que o do alelo C57BL/6, que apresenta apenas uma CpG que é pouco metilada em seu promotor. Nossos resultados sugerem que as alterações na região promotora influenciam a probabilidade com que o gene OR é escolhido para ser expresso no MOE

Olfactory receptor (OR) genes belong to a large family of membrane proteins composed of 1000 genes in the mouse genome. The OR genes are expressed in the olfactory sensory neurons (OSNs) in a monogenic and monoallelic fashion. However, the mechanisms that govern OR gene expression are unclear. Here we asked whether DNA methylation plays a role in the regulation of OR gene expression. We first determined the DNA methylation pattern in the coding (CDS) and promoter regions of the odorant receptor gene Olfr17. In olfactory epithelium (MOE) cells, the CpG methylation level in the CDS is 58% but is much lower in the promoter region of the gene. In embryonic MOE (E15.5) and liver, the levels of Olfr17 DNA methylation are similar to the ones shown in adult MOE. We next analyzed whether DNA methylation is involved in Olfr17 regulation. We isolated GFP+ neurons from transgenic mice that coexpress GFP with Olfr17, and analyzed the DNA methylation pattern of the Olfr17, which is active in these cells. We found that the general methylation pattern, both, in the coding and promoter regions is not altered in the active gene. These results indicate that changes in DNA methylation are not required for the activation of Olfr17. Finally, we found that the Olfr17 promoter region from two different mouse strains, C57BL/6 and 129, has two single-nucleotide polymorphisms (SNPs) that alter the CpG content. The SNPs lead to the existence of two additional CpGs in the 129 allele, which are absent in the C57BL/6 allele. These CpGs are frequently methylated, making the 129 Olfr17 promoter significantly more methylated than the Olfr17 promoter from C57BL/6. We next performed RT-qPCR experiments to analyze the expression levels of the 129 and C57BL/6 Olfr17 alleles in the MOE. These experiments showed that the expression level of the 129 Olfr17 allele, which contains three methylated CpGs in its promoter region, is lower than the one from C57BL/6, which contains only one, undermethylated CpG, in its promoter. Our results suggest that these promoter modifications regulate the probability of the OR gene choice

Preliminary Study on Compatibility Rationality of Sodium Bisulfite in Zhengqing Fengtongning Injection / 中国药师

Objective: To analyze the compatibility rationality between the raw material and auxiliary material sodium bisulfite in Zhengqin Fengtongning injection.Methods: HPLC was applied to detect the contents of the impurity and the main component in Zhengqing Fengtongning injection, and ion chromatography was applied to determine the content of sodium bisulfite in Zhengqing Fengtongning injection.The changes of impurity, main component and sodium bisulfite among the samples were compared before and after the stress testing (high temperature at 40℃, 60℃ and illumination at 4 500 lx).LC-MS-MS was used to identify the structures of the impurities.Results: The impurity in Zhengqing Fengtongning injection was the combination of the raw material and sodium bisulfite.Conclusion: It is irrational for Zhengqing Fengtongning injection to use sodium bisulfite as the antioxidant.

Application strategy of DNA methylation and bisultite sequencing in medicinal plants / 中草药

DNA methylation is one of the most widely epigenetics phenomena, methylated DNA can regulate the phenotype of plants without changing the nucleotide sequence. In higher plants, there are three methylated sites, CG, CHG, and CHH (H stands for A, C, or T). They often occur in symmetrical sequences CG and repetitive sequence, and methylation degrees and patterns are different among different species. The methylation of functional gene promoters can suppress the gene expression in medicinal plants, and then affect the accumulation of secondary metabolites, resulting in quality variations. Among many methods for the DNA methylation detection, bisulfite sequencing can identify the site and extent of DNA methylation at single nucleotide level, which is the gold standard for DNA methylation analysis. Through optimizing primers and improving technology, it can effectively reveal the DNA methylation status for medicinal plants and provide technical support and a new research direction for clarifying some problems such as quality variations in medicinal plants, which are not completely explained by classical genetics.

5'-flanking regulatory sequence methylation of the Boule gene in the testis tissue of infertile men with Sertoli cell-only syndrome / 中华男科学杂志

<p><b>Objective</b>To investigate the 5'-flanking regulatory sequence methylation status of the Boule gene in the testis tissue of infertile men with Sertoli cell-only syndrome (SCOS).</p><p><b>METHODS</b>We collected biopsy samples of the testis tissue from 12 men with obstructive azoospermia (the control group) and 15 cases of SCOS, all without varicocele, cryptorchidism, or infectious disease. We extracted genomic DNA from the testis tissue of the SCOS patients, analyzed the characteristics of the 5'-flanking regulatory sequence of the Boule gene using the bioinformatics method, and detected the methylation status of the Boule gene by sodium bisulfite sequencing.</p><p><b>RESULTS</b>A CpG island was observed in the 5'-flanking regulation region of the Boule gene. The methylation level of the Boule gene was remarkably higher in the SCOS group than in the obstructive azoospermia controls (61.4% vs 21.7%, P<0.01), with significant differences in the methylation levels of 14 CpG sites, namely, －58 bp, －50 bp, －48 bp, －38 bp, －28 bp, －24 bp, －20 bp, －15 bp, －1 bp, +5 bp, +8 bp, +15 bp, +29 bp, and +58 bp.</p><p><b>CONCLUSIONS</b>The methylation level of the Boule gene is significantly higher in the SCOS patients than in the obstructive azoospermia males, which suggests that the changes in Boule methylation may be associated with spermatogenic dysfunction.</p>

Synthesis and application of a fluorescent molecular probe for rapid detection of sulfur dioxide residues in traditional Chinese herbs / 中国药科大学学报

@#A fluorescence method based on a “turn-on” rhodamine derivative fluorescent probe was developed for the detection of hydrogen sulfite ions and sulfur dioxide residues in sulfur-fumigated herbs. This method was realized through a well-known aldehyde-bisulfite addition reaction accompanied by a ring opening of spirolactam of probe molecule in pH 4. 8 aqueous ethanol media which resulted in a significant fluorescence and color change. The fluorescence enhancement was linearly proportional to the concentrations of bisulfite ranging from 0. 005 to 20 μmol/L with a correlation coefficient of 0. 998 5. The detection limit was low as to 2. 0 nmol/L and there was no interference with other familiar co-existing anions, cations and reducing reagents indicating high sensitivity and selectivity of the proposed method. In addition, the novel probe was successfully applied for the identification of sulfur dioxide residues in herbs with a satisfactory recovery in five real samples.

Expression and promoter methylation of Kras gene in thymic lymphomas induced by ionizing radiation / 吉林大学学报(医学版)

Objective To study the changes of mRNA and protein expressions of Kras gene in thymic lymphomas induced by ionizing radiation,and to detect the methylation of CpG islands in promoter region of Kras gene,then to investigate the mechanisms for the occurrence of radiation carcinogenesis.Methods The thymic lymphoma models of BALB/c mice were made by X-ray irradiation,then the total RNA was extracted,cDNA was synthesized and the total protein was extracted from both thymic lymphoma tissue and normal thymus tissue;the mRNA and protein expressions of Kras gene in thymic lymphoma tissue and normal thymus tissue were detected by RT-PCR and Western blotting method, and the methylation of CpG islands in promoter region of Kras gene was detected by bisulfite sequencing PCR. Results The mRNA expression level of Kras gene in thymic lymphoma tissue was significantly higher than that in normal thymus tissue(P<0.01).The protein expression level in thymic lymphoma tissue was about 1.41 times higher than that in normal thymus tissue;4 CpG sites were methylated detected by bisulfite sequencing PCR in normal thymus tissue, however, 1 CpG site was methylated in thymic lymphoma tissue,the CpG islands in promoter region of Kras gene were demethylation state in thymic lymphoma. Conclusion Ionizing radiation can cause the changes of mRNA and protein expression levels of Kras gene in thymic lymphoma tissue by demethylation state of Kras gene,eventually lead to the occurrence of tumor;it might be one of the mechanisms for the occurrence of radiation carcinogenesis.

Determination of Impurities in Pharmaceutical Adjuvant Sodium Bisulfite by IC / 中国药师

Objective: To determine the impurities in pharmaceutical adjuvant sodium bisulfite. Methods: An IC method was used with a Dionex IonPac AS17-C RFIC analytical column. ECD was used as the detector by gradient elution and the temperature of column was 30℃. Results:Sulfate radical was detected out in all samples. Conclusion:The method is simple and fast with high sensi-tivity, which is suitable for the determination of related substances in sodium bisulfite.

Performance characteristics of bisulfite conversion and SYBR green based quantitative PCR for DNA methylation analysis.

Genomic DNA methylation is one of the most important epigenetic modifications in eukaryotes play vital role in development of severe disease like cancer. Many techniques used for assessment of DNA methylation, bisulfite treatment followed by methylation specific polymerase reaction (MSP) are one of them, which introduce conversion of unmethylated cytosine into uracil. The significant level of bisulfite treated DNA degradation results in the failure of methylation detection. Therefore, this step is to be properly controlled to avoid the degradation of DNA. In the present study, an attempt has been made to access the incubation time of DNA with bisulfate treatment at three time points i.e. 2.5, 4 and 16 hrs to get complete conversion of cytosine to uracil. Currently, the experiments were undertaken using oral cancer tissue, with varying incubation time of bisulfite treatment and 2 representative genes viz MGMT and p16 were selected for the quantitative assessment of methylation by real time PCR. Both genes are frequently methylated at promoter region in carcinogenesis. The short term incubation for 4hrs indicated better real time threshold value for p16 and MGMT gene methylation (Ct 25.55, 27.25) and unmethylation (Ct 18.82, 25.84) in tissue whereas it was 28.16, 37.35 and 21.98, 26.19 in blood sample, respectively as compared to other incubation time which shows less degradation of full length DNA.

Methylation-specific PCR analysis in Col8A1 promoter in Creole cattle carrier of rob(1; 29)

Robertsonian translocation (rob(1;29)) is the most frequent structural chromosomal abnormality in cattle. Heterozygous carriers have a normal phenotype but show a 3-5 percent decrease in fertility. Chromatin decondensation was evaluated similar to the inactive X chromosome when submitted to demethylating agent. Based on this result, and the concept that imprinted genes are essential in embryonic development, we decided to query genes located on BTA1 and BTA29 that could undergo genome imprinting. The collagen typeVIII- alpha 1 (Col8A1) acted on extracellular matrix structural proteins. DNA bisulfite conversion and sequentiation methods were used to compare its differential methylation patterns. It was performed on eight Creole cattle DNA blood samples from normal and rob(1;29) carriers. An in silico screening for CpG islands in its promoter uncovered a single region of 454 bp prone to methylation. BiQ-Analizer software was used to show the selective conversion of unmethylated cytosines to uracils obtaining the following results: unmethylated CpGs: 0.000 (0 cases), methylated CpGs: 0.802 (77 cases) and CpGs not present: 0.198 (19 cases). No differences between samples were observed in this highly methylated region. This technique was successfully applied so it is a straightforward methodology that can be utilized to evaluate different tissue associated to specific gene expression.

A Visualization Tool for Computational Analysis of DNA Methylation Level Using Bisulfite Sequencing Data

Methylation of cytosine is a post-synthesis modification that does not affect the primary DNA sequence but greatly influences gene expression level and phenotypes of an organism. As high-throughput sequencing of bisulfite-treated DNA is the most efficient method to identify methylated sites, several tools to map sequencing reads on a reference are available. But tools to visualize and to interpret the methylation level of methylation sites are currently insufficient. Herein, we present a novel tool to visualize the methylation level of CpG sites.

An improved bisulfite genomic sequencing for DNA methylation marker scanning / 中华检验医学杂志

Objective To develop a simplified bisulfite genomie sequencing(BGS)method for DNA methylation marker scanning.Methods According to modified BGS protocol,the desalt DNA treated with bisulfite were directly used for bisulfite-PCR(BSP)without alkali treatmenL Complement of the bisulfite modification Wag accomplished by a prolonged pre-denaturation stage.After BSP,a second round PCR was performed with a pair of GC tagged primers to adjust the GC content of the amplieon for direct sequencing.To assess this improved protocol,promotor methylation of TNF-α gene in 3T3-L1 cell and androgen receptor(AR)gene in Hela cell was investigated.The real time BSP for Alu was also used to compare the sensitivity of the modified assay with traditional assay.Results Both the hypermethylated TNF-α promotor and hypomethylated AR promotor were successfully sequenced by improved BGS method,and the results were consistent with that of the traditional assay.The conversion rate reached 100%,while the conversion specificity was higher than 93.75%.The sensitivity of improved BGS method inereaged significantly(t=2.978 2,P＜0.05)and showed good reproducibility.Condusion The improved BGS method is simple and sensitive,facilitating more ambitious genomic methyhtion mapping studies.

Role of 5'-CpG island hypermethylation of the FHIT gene in cervical carcinoma / 부인종양

OBJECTIVE: The abnormal expression of fragile histidine triad (FHIT) gene has been frequently reported in a variety of epithelial malignancies including cervical carcinoma. Furthermore, in a recent study it was proposed that transcriptional inactivation of FHIT, as a consequence of aberrant 5'-CpG island methylation, plays an important role in the carcinogenesis of human cervical carcinoma. The authors sought to determine whether abnormal FHIT transcription occurs in human cervical carcinoma, and if so, whether this abnormal expression is associated with aberrant 5'-CpG island methylation. In addition, the clinical significance of FHIT inactivation was investigated in Korean women with cervical cancer. METHODS: To examine for abnormal transcripts of the FHIT gene, quantitative RT-PCR, genomic DNA-PCR and nonisotopic RT-PCR-SSCP analysis were performed using the standard method. The methylation status was determined by methylation specific PCR and bisulfite DNA sequencing. RESULTS: The FHIT gene was down-regulated in 15 of 58 (25.9%) cervical carcinomas. FHIT promoter hypermethylation was detected in 15 of 15 (100%) abnormally expression in cervical carcinomas. Bisulfite DNA sequencing confirmed these findings and a significant correlation was found between CpG site hypermethylation and low FHIT expression. However, no significant correlation was found between reduced FHIT expression and clinicopathological characteristics. CONCLUSION: In this study, FHIT inactivation in cervical cancer was found to be strongly correlated with 5'-CpG island hypermethylation rather than a genetic alteration. Furthermore, no significant relation was found between a lack of FHIT expression and the prognostic factors of cervical cancer in our Korean cohort.

DNA methylation of TPEF gene in head and neck squamous cell carcinoma cell lines

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. The molecular mechanisms involved in the development and progression of these carcinomas are not well known. Abnormalities of genomic methylation patterns have been attributed a role in carcinogenesis and local de novo methylation at tumor suppressor loci was held to be involved in silencing of tumor suppressor genes. Using Ms APPCR, we previously isolated a hypermethylated fragment corresponded to the 5'end of TPEF gene from primary liver and lung cancer cells. To confirm the inactivation of TPEF gene by hypermethylation in HNSCC, we investigated correlation between methylation pattern and expression of TPEF in 10 HNSCC cell lines. In methylation analysis such as combined-bisulfite restriction analysis(COBRA) and bisulfite sequencing, only RPMI 2650 showed none methylated pattern and another 9 cell lines showed dense methylation. The TPEF gene expression level analysis using RT-PCR showed that these 9 cell lines had not or significantly low expression levels of TPEF as compared with RPMI 2650. In addition, the increase of TPEF reexpression by 5-AzaC as demethylating agent in 9 cell lines also indicated that TPEF expression was regulated by hypermethylation. These results of this study demonstrate that epigenetic silencing of TPEF gene by aberrant methylation could play an important role in HNSCC carcinogenesis.

Removal of Low Concentration Formaldehyde in Indoor Air by Chemisorption / 环境与健康杂志

Objective To remove formaldehyde of the low concentration in the indoor air and purify the indoor air. Methods The concentration of formaldehyde was determined by MBTH spectrophotometry and the removal efficiency of low concentration formaldehyde in the indoor air by using sodium sulfite, sodium bisulfite, ammonium sulfate, ammonium chloride, ammonium molybdate and potassium permanganate was tested. Results As the concentration of formaldehyde was at 1 mg/L, 10 mg/L and 100 mg/L respectively, the removal rate of formaldehyde of sodium sulfite, sodium bisulfite and potassium permanganate was 15.9%, 74.7% and 93.5% respectively. On the acidity condition or alkalescence, potassium permanganate was also effective in removing of the different concentration formaldehyde was 23.8%, 74.7% and 93.5%. Ammonium molybdate and potassium permanganate could remove the formaldehyde by 25.9% and 35.7% when the concentration of formaldehyde was at 10 mg/L and 100 mg/L. Ammonium sulfate or ammonium chloride could not effectively remove the low concentration formaldehyde and the removal rate was under 7.0%. Conclusion On the acidity condition or alkalescence, potassium permanganate is effective in removing of the low concentration formaldehyde in the indoor air.

Oxidation Damage of Sulfur Dioxide Inhalation on Erythrocytes of Rats / 环境与健康杂志

Objective The aims of the present study are to further investigate mechanism of toxicological role of sulfur dioxide (SO 2) exposure on mammalian animals Methods Effects of SO 2 inhalation (14 mg/m 3) on activities of antioxidative enzymes and levels of lipid peroxidation in erythrocytes of male rats were determined Results SO 2 inhalation caused the decrease of Cu,Zn SOD activity,the increase of GSH Px activity,and no change of CAT activity,and the increase of level of lipid peroxidation in rat erythrocytes Conclusion Primary mechanism of toxicological role of SO 2 exposure at low concentrations may be that oxidation damages of lipid and other biological large moleculars are caused by SO 2 producing reactive oxygen species

ANTIMUTAGENIC EFFECT OF P—AMINOBENZOIC ACID AND SODIUM EISULFITE ON THE MUTAGNICITY OF N-METHYL-N-NITRO-N-NITROSOGUANIDINE / 西安交通大学学报(医学版)

Antimutagenic effect of p-aminobenzoic acid (PABA) and sodium bisulfite (NaHSO_3)on the mutagenicity of N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was detected by the mehod of human lymphocytes unscheduled DNA Sythesis (LIDS). The results showed that when the concentration of PABA and NaHSO_3 was varied in presence of a constant concentration of MNNG, 5 ?10~(-5) mol/L concentration of PABA, 3 ? 10~(-4) mol/L concentration of NaHSO_3 were the most effective, while the concentration of MNNG varied in the presence of a constant concentration of PABA and NaHSO_3, antimutagenicity was the most effective at high concentration of MNNG. The results indicated that the PABA and NaHSO_3 exhibited antimutagenic activity towards MNNG-induced mutagenicity in LIDS and the extents of antimutagenicity were related with the concentration of MNNG.