Occupational exposure limits of methyl t-butyl ether in workplace air / 中国职业医学

OBJECTIVE: To establish the occupational exposure limits for methyl t-butyl ether(MTBE) in the air of workplace in China. METHODS: According to the GBZ/T 210.1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace, we collected and analyzed data on physical and chemical properties, toxicology, occupational epidemiology and foreign occupational exposure limits related to MTBE by literature search. A total of 180 occupational workers exposed to MTBE were selected as exposure group, and 155 workers and administrative logistics personnel without exposure to MTBE were selected as the control group. Occupational hygiene investigation and occupational physical examination were carried out. We deduced the occupational exposure limits for MTBE in workplace air in China by combining literature data. RESULTS: The time-weighted average(TWA) of MTBE in the workplace air developed by the United States of America and Britain is 180.00 mg/m~3. The short-term exposure limit(STEL) of MTBE in the workplace air developed by Australia and New Zealand is 270.00 mg/m~3. The concentration of TWA(C_(TWA)) of MTBE in the exposure group was less than 0.08-4.90 mg/m~3. The concentration of short term exposure was less than 0.10-14.28 mg/m~3, and the C_(TWA) was less than 0.02-83.66 mg/m~3, in parts of workplaces. There was no statistically significant difference on the self-conscious discomfort and the abnormality in physical examination between these two groups(P>0.05). CONCLUSION: It's recommended that the permissible concentration-TWA of MTBE should be set at 180.00 mg/m~3, and the permissible concentration-STEL should be set at 270.00 mg/m~3 in China.

Study on the efficacy and safety of tiotropium bromide inhalation agent with tulobuterol patch in the treat- ment of C and D level in patients with chronic obstructive pulmonary disease in stable period / 中国基层医药

Objective To explore the effectiveness and safety of tiotropium bromide inhalation agent with tulobuterol patch in the treatment of C and D level of COPD in stable period .Methods According to the digital table,255 cases of C and D level in patients with stable COPD were randomly divided into the study group and control group,the patients in study group received inhalation of tiotropium bromide dry powder 18μg/times,one time every day,and give tulobuterol patch(2mg/paste),one time every day.The control group received inhalation of tiotropium bromide dry powder 18μg/times,one time every day.The changes of lung function were observed before and after treatment,the clinical symptom score and inhaled short acting beta 2 agonists used,6min walk test,times of acute exacerbation condition.Results The patients in the two groups after treatment ,pulmonary function ,clinical symptoms score,inhaled short acting beta 2 agonists used,6min walk test,times of acute exacerbation compared with statistical significance(all P0.05).Conclusion Tiotropium bromide inhalation agent with tulobuterol patch can improve clinical symptoms and pulmonary function in patients with C and D level part of the stable phase of COPD .

Application of risk grading and classification for occupational hazards in risk management for a shipbuilding project / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the application of risk grading and classification for occupational hazards in risk management for a shipbuilding project.</p><p><b>METHODS</b>The risk management for this shipbuilding project was performed by a comprehensive application of MES evaluation, quality assessment of occupational health management, and risk grading and classification for occupational hazards, through the methods of occupational health survey, occupational health testing, and occupational health examinations.</p><p><b>RESULTS</b>The results of MES evaluation showed that the risk of occupational hazards in this project was grade 3, which was considered as significant risk; Q value calculated by quality assessment of occupational health management was 0.52, which was considered to be unqualified; the comprehensive evaluation with these two methods showed that the integrated risk rating for this shipbuilding project was class D, and follow- up and rectification were needed with a focus on the improvement in health management.</p><p><b>CONCLUSION</b>The application of MES evaluation and quality assessment of occupational health management in risk management for occupational hazards can achieve objective and reasonable conclusions and has good applicability.</p>

Determination of stannum in urine by graphite furnace atomic absorption spectrometry / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the method of graphite furnace atomic absorption spectrometry for the measurement of stannum in urine with calcium nitrate as the matrix modifier.</p><p><b>METHODS</b>Graphite tube was pretreated with calcium nitrate as the matrix modifier, the urine sample was diluted with 1% nitric acid and then direct injection was performed for these samples, and graphite furnace atomic absorption spectrometry was applied for measurement.</p><p><b>RESULTS</b>The concentration of stannum in urine showed a good linear relationship within the range of 8.0~40.0 μg/L, with a correlation coefficient of 0.9981. The minimum detectable concentration was 0.72 μg/L, the degree of precision was 1.54%~6.69%, and the recovery rate was 99.23%~107.63%.</p><p><b>CONCLUSION</b>This method can determine the content of stannum in urine accurately and rapidly, with a high sensitivity and a low cost.</p>

Determination of N acetyl-S-(2-carbamoylethyl)-cysteine in urine by high-performance liquid chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the method of high-performance liquid chromatography HPLC for the determination of N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA) in urine.</p><p><b>METHODS</b>After acid hydrolysis, AAMA in urine was converted into S-2-carboxyethyl cysteine (CEC). CEC reacted with the derivative reagent ophthalaldehyde and formed the derivative with strong fluorescence absorption. The HPLC-fluorescence detector was applied, with an excitation wavelength of 340 nm and an emission wavelength of 450 nm.</p><p><b>RESULTS</b>Urinary AAMA demonstrated an excellent linearity in the range of 5.3~123.5 μmol/L, with a correlation coefficient of 0.9994. The minimum detectable concentration was 0.1 μmol/L (the volume of urine sample was 1.0 ml), the recovery of standard addition was 97.4%~104.2%, and the between-run precision was 2.3%~4.3%. The sample could be stored in the refrigerator for at least 7 days at a temperature of 4℃.</p><p><b>CONCLUSION</b>The method is simple, with a low cost, a high sensitivity, and good precision and accuracy, and the instrument and equipment commonly seen in laboratories are applied. Therefore, this method is worthy of wide application.</p>

Isolation and characterization of a new Methanosarcina mazei strain GFJ07 from a mountain forest pond

Aims: A new methanogenic strain, named GFJ07, was isolated from a pond of mountain forests in Guangxi, China. Cells grown in liquid culture tended to form aggregates with pseudosarcina-like or irregular shape. Methodology and Results: The optimum temperature, pH and NaCl concentration were 35 ℃, 7.0 and 0.5%, respectively. The isolate used methanol, trimethylamine, acetate and H2-CO2 as substrates. Analysis of the 16S rDNA sequences revealed strain GFJ07 showed the highest sequence similarity of 99.9% to Methanosarcina mazei. Conclusion, significance and impact of study: The cells were Gram positive and nonmotile. Most of single cell grew as a sausage-like clinder about 0.5 μm in diameter and 1.0 μm in length.

Analysis of volatile components of flowers of Fritillaria thunbergii by GC-TOF-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To determine the structures and contents of the volatile components of flowers of Fritillaria thunbergii, and investigate the effects of operation modes on its volatile components.</p><p><b>METHOD</b>The volatile oils were first obtained by the hydrodistillation assay and then submitted to gas chromatography-time-of flight mass spectrometry (GC-TOF-MS) analysis.</p><p><b>RESULT</b>More than 60 peaks were resolved, and 39 of which were identified quantitatively and qualitatively based on high-resolution spectra and compounds library screening. Among these identified components, the octadecatrienoic acid methyl esters were major components in the unprocessed flowers, while some aromatic aldehydes and ketones, such as benzeneacetaldehyde and 1-(2-hydroxy-5-methylphenyl)-ethanone, were prominent components in the flowers both dried in the fluidized bed and in shadow. In addition, the flowers dried in the fluidized bed were more fragrant than other flowers.</p><p><b>CONCLUSION</b>The component and contents closely related to their processing mode, and the fluided bed drying may be a best choice to process the flowers of F. thunbergii.</p>

Effect of 8-nitrochyrsin on the proliferation and apoptosis of HL-60 cells / 基础医学与临床

Objective To investigate the effect of 8-Nitrochyrsin on cell proliferation and cell apoptosis of HL-60 cells in vitro.Methods 8-Nitrochyrsin on proliferation of HL-60 cells was detected by MTT assay;The trypan blue exclusion method was used to count the number of viable and dead cells,then the survival rate and growth curve were achieved;DNA ladder bands were observed by DNA agarose gel electrophoresis;HL-60 cell apoptotic percentage was detected by flow cytometry with PI staining.Results 8-Nitrochrysin inhibited proliferation of HL-60 cells in a concentration-dependent manner;8-Nitrochyrsin possess the inhibitory effect on the proliferation and growth of HL-60 cells;8-Nitrochrysin possess the significantly effect of inducing apoptosis of HL-60 cells.Conclusion 8-Nitrochyrsin possess the inhibitory effect of the proliferation and growth of HL-60 cells and significantly induces apoptosis of HL-60 cells.

The role of reactive oxygen species in epigallocatechin-3-gallate-induced apoptosis of human gastric cancer MGC803 cells / 中国癌症杂志

Background and purpose:Anticancer mechanism of epigallocatechin-3-gallate(EGCG)remains unclear.This study investigated the role of reactive oxygen species(ROS)in epigallocatechin-3-gallate(EGCG)-induced apoptosis in human gastric cancer MGC803 cells.Methods:The inhibition of MGC803 cells growth was measured by MTT assay.Apoptosis of MGC803 cells was studied by using the AO/EB fluorescence stain.Flow cytometry was used to detect the intracellular ROS level and the rate of apoptosis.Results:EGCG could induce apoptosis of MGC803 cells and increased in the intracellular ROS level.However,after treatment with N-acetyl-L-cystein and an athiol-containing antioxidant,the inhibitory effect of EGCG on MGC803 cells was significantly weakened.The apoptotic rate of the cells and the activity of the intracellular ROS level also decreased dramatically.Conclusion:EGCG can induce apoptosis of MGC803 cells.In turn,the ROS inhibitor can significantly inhibit the apoptosis induced by EGCG in MGC803 cells.These results suggest that the cellular generation of ROS plays a role in initiating EGCG-mediated apoptosis of MGC803 cells.

Analysis of Policies on Human Embryonic Stem Cells in foreign countries / 中国医学伦理学

Stem cell research is one of the most notable fields in life science at the end of 20th century and the beginning of 21st century,which has made a considerable contribution to every aspect of life science,especially to the regenerative medicine.However,a great debate on ethics has also arisened all over the world on the research of human embryonic stem cells.This paper gives the cause of the debate,provides the analysis of the stem cell legislations among various countries,which have different impacts on the research of stem cell and finally points out its enlightenment to our country.