Biological exposure limit of 1,3-butadiene occupational exposure / 中国职业医学

OBJECTIVE: To study the biological exposure limit of 1,3-butadiene occupational exposure. METHODS: A total of 139 workers who exposed to 1,3-butadiene in a rubber plant was chosen as exposure group,and 45 workers without 1,3-butadiene exposure were chosen as control group by judgment sampling method. Gas chromatography-flame ionization detection method was used to detect the level of 1,3-butadiene in workplace air,and ultra-high performance liquid chromatography-tandem mass spectrometric was used to determine the level of urinary dihydroxybutyl mercapturic acid( DHBMA) in end-of-shift workers. The correlation between 1,3-butadiene level and urinary DHBMA level was analyzed.The biological limit of 1,3-butadiene occupational exposure was assessed. RESULTS: The range of concentration-time weighted average( C_(TWA)) of 1,3-butadiene was from 0. 004 to 7. 609 mg/m~3,the medium was 0. 253 mg/m~3 in the exposure group,while the level of urinary DHBMA was from 0. 171 to 4. 235 mg/g Cr,and the medium was 1. 220 mg/g Cr. The range of C_(TWA)of 1,3-butadiene was below detection limit in the control group. The level of urinary DHBMA was from 0. 157 to 1. 808 mg/g Cr,and the medium was 0. 627 mg/g Cr in the control group. The level of urinary DHBMA in the exposure group was higher than that of the control group( P < 0. 01). The level of urinary DHBMA( y) of workers was related to the level of 1,3-butadiene( x) of the workplace air in the exposure group( y = 0. 349 x + 1. 082,P < 0. 01).CONCLUSION: DHBMA in urine could be used as a biomarker for 1,3-butadiene exposure in workers. The recommended biological exposure limit of DHBMA is 2. 900 mg/g Cr.

Effects of polymorphisms in XRCC1 and APE1 on vinyl chloride-induced chromosome damage / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of polymorphisms in XRCC1 and APE1 genes on vinyl chloride (VC)-induced chromosomal damage in peripheral lymphocytes.</p><p><b>METHODS</b>In this study, 317 workers occupationally exposed to VC were recruited from a factory in Shandong Province, China. The micronucleus (MN) frequency in peripheral lymphocytes was used as an indicator of chromosomal damage. Polymerase chain reaction-restriction fragment length polymorphism and created restriction site combined with restriction fragment length polymorphism were used to determine the five single nucleotide polymorphisms in XRCC1 and APE1 genes in the base excision repair pathway. The association of chromosomal damage with these polymorphisms and the haplotype of XRCC1 was analyzed using Poisson regression and PHASE 2.0.2.</p><p><b>RESULTS</b>It was found that among the VC-exposed workers, individuals with XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) had a significantly higher MN frequency than those with homozygous wild-type genotypes, with frequency ratios (FR) as follows, respectively: FR = 1.21, 95%CI: 1.05∼1.39 (P < 0.05); FR = 1.14, 95%CI: 1.00∼1.38 (P < 0.05); FR = 1.26, 95%CI: 1.11∼1.44 (P < 0.05); FR = 1.23, 95%CI: 1.08∼1.46 (P < 0.05). APE1 Asp148Glu was found of no significant relationship with MN frequency. Haplotype analysis of XRCC1 demonstrated that the MN frequencies in subjects with CTAA/CTAA and CCAA/CTAA were significantly higher than that in those with TCGG/TCGG (FR = 1.19, 95%CI: 1.02∼1.32, P < 0.05; FR = 1.41, 95%CI: 1.02∼1.87, P < 0.05). Furthermore, association was found between accumulated exposure to VC and XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) after adjustment for age, sex, drinking, and smoking.</p><p><b>CONCLUSION</b>VC can induce chromosomal damage even when the exposure level is lower than the national occupational health standard of China (PC-TWA: 10 mg/m(3)); the polymorphisms in XRCC1 and APE1 are associated with chromosomal damage induced by VC.</p>

Promoter methylation of DAPK1, RAR-β and MGMT in exfoliated cervical cytology and its clinicalapplication / 中华妇产科杂志

Objective To assess the correlation of promoter methylation of DAPK1,RAR-β and MGMT with cervical lesions from cytology to histology,and to reveal the clinical value of DNA methylation in diagnosis of cervical intraepithelial neoplasia (CIN).Methods A total of 103 random-selected cervical samples were collected from residual liquid-based cytology specimens after clinical use in cytopathological diagnosis in outpatient clinic of obstetrics and gynecology,Peking Union Medical Collage Hospital from March 2010 to October 2010.Informed consent was obtained from each woman before the initiation of the study.The methylation seusitive-high resolution melt (MS-HRM) assay was used to evaluate promoter methylation of three genes ( DAPKI,RAR-β and MGMT) in 103 biopsy-confirmed liquid-based cervical cytology samples.Methylation levels and high-risk HPV DNA loading ( HC Ⅱ values) were analyzed in relation to both cytological and histological diagnosis.Results The methylation level of all three genes showed significant difference among the different cytological groups ( P =0.000,0.011 and 0.002,respectively).The methylation level of DAPK1 and RAR-β showed significant difference among the different histological groups ( P =0.000 and 0.021 ),while there was no significant difference for MGMT.DAPK1 methylation levels was 1.47％ in the CIN Ⅱ/high-grade precancerous lesions group,and 20.98％ in the normal/CIN I groups ( P =0.000 ),but there was no significant difference between CIN I/high-grade precancerous lesions and normal/CIN Ⅰ groups for RAR-β and MGMT.The combination of DAPK1/HR-HPV loading showed a sensitivity of 0.825 and an area under the receiver operating characteristic curve (ROC) curve (AUC) of 0.695 as diagnostic methods for detecting CIN Ⅱ/high-grade precancerous lesions.Conclusions DNA methylation such as DAPK1 and RAR-β,in combination with HR-HPV detection,may serve as biomarkers to detect CIN Ⅱ/high-grade precancerous lesions.Detection of methylated DNA from liquid-based cervical cytology specimens is technically feasible with the MS-HRM assay.

Two-dimensional numerical analysis of impact response of the human tibia in Car-pedestrian accidents / 国际生物医学工程杂志

Objective The purpose of this paper was to use a new biphasic poroelastic tibia model to develop a two-dimensional numerical method for simulating impact responses of human tibia in car-pedestrian accidents. Methods The geometry of tibia model was reconstructed from CT scans of the left tibia of a living human volunteer. A poroelastic approach was utilized to establish the governing equations of the model and the finite element method was applied to solve these governing equations. Both cortical and cancellous components of tibia were represented using a poroelastic material model consisting of solid phase (matrix) and fluid phase (marrow). A lateral-medial impact direction was selected in the simulation analysis and the impact responses of the pedestrian tibia during 0-200 ms were analyzed. Results The bending deformation of the tibia predicted by the computer simulation was primarily concentrated on the impact zones. The displacement response of Node 107 in the impact zone indicated a peak displacement of -6 mm at around 75 ms, and the significant time delay between the impact force and the displacement response of the skeleton. The axial stress response at the center of element E77 in the impact zone indicated a peak stress of 140 MPa at around 30 ms,and the significant time delay was observed between the impact force and the axial stress response of the skeleton, too. Conclusion This research developed a two-dimensional numerical method for simulating impact responses of human tibia in car-pedestrian accidents. It was able to approximately simulate the bending deformation, lateral displacement response and axial stress response of pedestrian tibia in the impact zones,and the effects of the fluid phase on the solid phase. More in-depth investigation is helpful to further the biofidelity of tibia dynamics model.

Investigation on representation methods of dissolubility property of total alkaloid extract from Peganum harmala / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the representation methods of dissolubility property of total alkaloid extract from Peganum hamala in different solvents, and to investigate the evaluation method of the dissolubility property of extracts from traditional Chinese medicine.</p><p><b>METHOD</b>The dissolubility property of the whole extract and markers of harmaline and harmine, as well as the particle diameter distribution of the extract in different solvents were evaluated by precipitation method, solubility test, and the particle diameter test.</p><p><b>RESULT</b>Both the alkaloid extract and it's index ingredients had good solubility in absolute ethanol, 95% ethanol, and 80% ethanol, while the solubility in 60% ethanol was poor, and worst in water. The sequence of particle diameter of extract in solvents was in the following order water > 95% ethanol > 60% ethanol > 60% ethanol > 80% ethanol.</p><p><b>CONCLUSION</b>The extract has good solubility in the ethanol solution whose concentration is over 80%. The results between precipitation method and index components method have certain correlation. The particle diameter method can provide distribution information of the extract in different solvents. Combination of those three methods could reflect the dissolubility property of extracts from traditional Chinese medicine more comprehensively.</p>

Investigation on quality standard of Franchet groundcherry / 中国中药杂志

<p><b>OBJECTIVE</b>To develop identification and assay methods of Franchet groundcherry.</p><p><b>METHOD</b>TLC method was used to identify of physalin L in the sample using high performance silica gel G plate and a mixture of chloroform-acetone-methanol (25:1:1) as a developing solvent. In the chromatogram, physalin L showed a distinct fluorescence spot under UV 365 nm with good separation. In the HPLC method, luteoloside was separated on a Venusil XBP C18 (4.6 mm x 250 mm, 5 microm) column with acetonitrile-0. 2% phosphoric acid (20:80) as the mobile phase with flow rate of 1 mL x min(-1). The detection wavelength was set at 350 nm.</p><p><b>RESULT</b>For the HPLC quantitation method, the calibration curve of luteoloside displayed ideal linearity over the range of 0.50-249.40 mg x L(-1) with the regression equation of Y = 55,313X + 3.1641 (r = 1.000). The average recovery of luteoloside was 98.79% with a RSD of 1.1%. And the intra-day and inter-day precisions were less than 2%.</p><p><b>CONCLUSION</b>The TLC identification and HPLC determination were sensitive, reliable and repeatable and can be applied for the quality evaluation and assessment of Franchet Groundcherry Calyx.</p>

Qualitative and quantitative analysis of plantamajoside in Plantaginis Herba / 中国中药杂志

Plantamajoside is one of the main bioactive compounds in Plantaginis Herba A TLC method was developed identification of plantamajoside in 11 Plantaginis Herba samples using silica gel G as coating substance and a mixture of ethyl acetiate methanol-formic acid-water (18: 3 : 1.5 : 1) as a developing solvent, the established TLC condition displayed a very well separation on the chromatogram of tested Plantaginis Herba samples and the marker compound plantamajoside showed as a distinct light-blue fluorescence spot observed under UV 365 nm. Using the HPLC method, plantamajoside was separated at 30 degrees C on a Promocil C18, (4.6 mm x 250 mm, 5 microm) column with acetonitrile-0.1% formic acid (17:83) as the mobile phase. The detection wavelength was set at 330 nm and the flow rate was 1 mL x min(-1). The calibration curve of plantamajoside displayed ideal linearity over the range of 0.0499-11.9664 microg (r = 0.9999), and the average recovery of plantamajoside was 100.6% with a RSD of 2.7%. The contents of plantamajoside were in the range of 0.067%-1.80% in Plantaginis Herba The established TLC identification and HPLC were sensitive, reliable and repeatable, which can be applied for the quality evaluation and standard criteria of Plantaginis Herba.

Prevalence of human papillomavirus infection in women in Tibet Autonomous Region of China / 中华妇产科杂志

Objective To determine the prevalence of cervical type-specific human papillomavirus (HPV)infection as well as risk factors associated in Tibet Autonomous Region of China.Methods A cluster sampling study was performed in Lasa,Rikaze and Naqu of Tibet.An epidemiological questionnaire was applied and 3036 cervical specimens were obtained for liquid-based cytology and HPV DNA detection.Statistical analysis included Wald Chi-square and stepwise logistic regression model.Results The overall HPV prevalence of involved 3036 women was 9.19%(279/3036),of which 7.05%(214/3036)of the women were infected by high-risk types (including 14 sorts of types) and 2.14%(65/3036)by low-risk types(including 6 sorts of types).There were no significant differences of HPV prevalence between age groups(P=0.936),race(P=0.718)and areas(P=0.746),respectively.Twenty-one types of HPV were detected,of which HPV16(1.52%) was the most common type,followed by HPV33(1.42%).HPV58(1.22%),HPV52(1.15%),and HPV31(1.05%).HPV type distribution was varied by age.Of the 279 HPV infected women.14.3%(40/279)exhibited multiple HPV infections.Independent risk factors for HPV infection were smoking(P=0.027),number of sex partners(P=0.198)and early age of first intercourse(P=0.237).Conclusion The overall prevalence of HPV infection in Tibet Autonomous Region is lower than that in China or abroad,in which the most common genotype is HPV16 and the independent risk factors for HPV infection included early age of first intercourse,smoking,and number of Bex partners.

Relativity Analysis of Abnormal Cervical Pathology Results in Cytology and Histology / 医学研究杂志

Objective To study the relativity analysis of abnormal cervical pathology results in cytology and histology.Methods With retrospective analysis of 31,634 cases of fluid-based thin-layer method(ThinPrep Cytology Test,TCT)of PUMC Hospital from January,2001 to March,2003,which reported in the Bethesda System,we checked the abnormal results and advised different diagnose biopsy of vaginoscopy and/or conization,and got the relativity description of abnormal results in TCT and CINⅢ/CIS results validated by vaginoscopy,match analysis of the CINⅡ～Ⅲ and CINⅢ/CIS results validated by vaginoscopy and conization labeled by the age group,and relativity analysis of abnormal results in TCT and CINⅢ/CIS results validated by vaginoscopy.Results Among 31,634 cases of TCT test,948 cases had confirmed biopsy results validated by vaginoscopy,of which 70 cases were of CINⅡ～Ⅲ,56 cases were of CINⅢ/CIS.The risk ratio(RR)of different abnormal TCT results in predicting CINⅢ/CIS results validated by vaginoscopy is:ASCUS group,14.7(95% confidence interval 8.0～27.0,P=0.00);CINⅠ group,13.9(6.3～30.9,P=0.00);CINⅡ group,44.2(15.5～126.5,P=0.00);CINⅢ group,272.2(161.6～458.6,P=0.00);Cancer group,unmeasured.As noted,there is no significant difference between the RR of ASCUS group and CINⅠ group(P=0.951)in predicting CINⅢ/CIS results.Conclusions Vaginoscopy examination and biopsy could verify histology abnormity of CINⅡ～Ⅲ及CINⅢ/CIS from abnormal results of TCT,and has a good accordance along with biopsy results of conization.There are significantly greater risk of being CINⅢ/CIS validated by vaginoscopy in the abnormal TCT patients,among which ASCUS group and CINⅠ group have the coequal risk.