Effect of vinyl chloride on liver function and serum sex hormones in male workers / 中国职业医学

OBJECTIVE: To explore the effect of vinyl chloride on the blood sex hormones and liver function of male workers. METHODS: A total of 129 male vinyl chloride workers(exposure group) and 128 male office workers who were not exposed to occupational hazards(control group) were selected as study subjects by judgment sampling method. The time weighted average concentration(C_(TWA)) of vinyl chloride in the workplace air was measured. The level of urine thiodiglycolic acid(TDGA), blood routine, electrocardiogram and liver B-ultrasound were performed on the subjects. The serum levels of liver function and sex hormones were measured. RESULTS: The median of C_(TWA) of vinyl chloride in the workplace was 0.90 mg/m~3, and the geometric mean was 1.40 mg/m~3. The level of urine TDGA in the exposed group was higher than that of the control group(median: 0.68 vs 0.02 mg/g Cr, P<0.01). The abnormal rate of hemoglobin level, erythrocyte count, leukocyte count, hematocrit, mean platelet volume, aspartate transaminase, total bilirubin, indirect bilirubin and liver B-ultrasound increased in the exposure group than that of the control group(P<0.05). The levels of serum prolactin, leuteinizing hormone(LH), follicle-stimulating hormone and estradiol in the exposure group increased, the abnormal rates of prolactin, LH and estradiol increased, and the level of testosterone decreased compared with the control group(P<0.05). The levels of prolactin in the low-, medium-and high-TDGA subgroups in the exposure group increased(P<0.05), and the abnormal rates increased compared with the control group(P<0.017). CONCLUSION: Vinyl chloride can cause liver function damage in male workers and have reproductive toxicity. Prolactin can be used as a biomarker of reproductive toxicity of vinyl chloride.

Effects of lead exposure on copper and copper transporters in choroid plexus of rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of lead exposure on the copper concentration in the brain and serum and the expression of copper transporters in the choroid plexus among rats.</p><p><b>METHODS</b>Sixty specific pathogen-free Sprague-Dawley rats were randomly divided into a control group and three lead-exposed groups, with 8 mice in each group. The lead-exposed groups were orally administrated with 500 (low-dose group)), 1 000 (middle-dose group), and 2 000 mg/L (high-dose group) lead acetate in drinking water for eight weeks. And the rats in control group were given 2 000 mg/L sodium acetate in drinking water. The content of lead and copper in the serum, hippocampus, cortex, choroid plexus, bones, and cerebrospinal fluid (CSF) was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Confocal and real-time PCR methods were applied to measure the expression of copper transporters including copper transporter 1 (Ctr1), antioxidant protein 1 (ATX1), and Cu ATPase (ATP7A).</p><p><b>RESULTS</b>Compared with the control group, the lead-exposed groups showed significantly higher lead concentrations in the serum, cortex, hippocampus, choroid plexus, CSF, and bones (P < 0.05) and significantly higher copper concentrations in the CSF, choroid plexus, serum, and hippocampus (P < 0.05). Confocal images showed that Ctr1 protein was expressed in the cytoplasm and cell membrane of choroid plexus in control group. However, Ctr1 migrated to CSF surface microvilli after lead exposure. Ctr1 fluorescence intensity gradually increased with increasing dose of lead, except that the middle-dose group had a higher Ctr1 fluorescence intensity than the high-dose group. In addition, the middle- and high-dose groups showed a lower ATX1 fluorescence intensity compared with the control group. Real-time PCR data indicated that the three lead-exposed groups showed significantly higher mRNA levels of Ctr1 and ATP7A compared with the control group (P < 0.05).</p><p><b>CONCLUSION</b>Copper homeostasis in the choroid plexus is affected by lead exposure to induce copper homeostasis disorders in brain tissue, which may be one of the mechanisms of lead neurotoxicity.</p>

Determination of cyanamide in workplace air by high-performance liquid chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a method for determining cyanamide in workplace air by high-performance liquid chromatography (HPLC).</p><p><b>METHODS</b>Air samples were collected from the workplace using the shock absorption tube containing water solution at a rate of 2.8∼3.0 ml/min for 60 min; dansyl chloride was used as a derivatization reagent to conduct pre-column derivatization, and the procedure was as follows: acetone solution (2.5 ml), mixed solution (1.0 ml) containing 0.016 mol/L Na2CO3 and 0.184 mol/L NaHCO3, and 10 mg/ml acetone solution of dansyl chloride (0.5 ml) were added into the samples, and reaction proceeded in a water bath (50 °C) for 1 h. HPLC was performed on an ODS C18 column (250 mm × 4.6 mm, 5 üm) with a mobile phase of acetonitrile-phosphate buffer (35:65) at a flow rate of 1.0 ml/min and a column temperature of 25°C; a fluorescence detector was used at an excitation wavelength of 360 nm and an emission wavelength of 495 nm.</p><p><b>RESULTS</b>The minimum detectable concentration of cyanamide was 0.05 üg/ml; a good linear relationship was noted when the concentration of cyanamide was 0.2∼100.0 üg/ml; the intraday relative standard deviation (RSD) was 0.28%∼1.18%, and the interday RSD was 0.22∼2.16%; the recovery rate was 95.7%∼103.0%, and the sampling efficiency was 95.8%∼96.9%. Water solution of cyanamide (pH<6.5) could be stable in the dark at room temperature for 7 d.</p><p><b>CONCLUSION</b>This method is stable, reliable, easy to operate, and highly sensitive and suitable for determination of cyanamide in workplace air.</p>

Molecular regulation of skeletal satellite cell's self-renewal / 生物医学工程学杂志

Skeletal muscle possesses a remarkable ability for its regeneration and injured tissue repair. This ability depends on the activity and contributions of muscle satellite cells. Proliferating satellite cells, termed myogenic precursor cells or myoblasts, are activated and driven out of their quiescent state upon muscle injury. In this summary, we present a review to summarize the molecular regulation in skeletal satellite cells to light on the satellite cells' self-renewal mechanism.

Association between serum levels of SP-A, SP-C and the impairment of lung function in coal workers with pneumoconiosis / 中国综合临床

Objective To investigate the relationship between serum levels of surfactant protein( SP)-A,SP-C and lung function impairment in coal workers with pneumoconiosis(CWP) in order to provide evidence for the biomarker study of pneumoconiosis.Methods Thirty-two coal workers with pneumoconiosis snd 41 healthy controls were included in this study.Serum levels of SP-A and SP-C were measured.Grading assessment of dyspnea and pulmonary function including predicted percentages of FVC,FEV1,FEV/FVC,MVV,and DLCO were conducted.Results Among the 32 participants with CWP,the severity of dyspnea was rated as level Ⅲ for 14 and level Ⅳ for 18 individuals.The pulmonary function was significantly impaired in CWP patients with level Ⅳ dyspnea compared with the healthy controls (FEV1％ predicted:[69.38 ± 15.17 ]％ vs.[96.35 ±10.24 ] ％ ; MVV％ predicted:[ 65.89± 8.14 ] ％ vs.[ 94.13 ± 10.38 ] ％ ; DLCO％ predicted:[ 96.51 ±11.37 ] ％.The serum levels of SP-A and SP-C were significantly higher in CWP patients than that in the healthy controls (SP-A:[4.02 ± 1.22] μg/L vs.[2.41 ±0.68 ] μg/L,t =6.480,P =0.001 ;SP-C:[3.58 ±0.67 ] ng/L vs.[ 2.31 ± 0.29] ng/L,t =9.290,P ＜ 0.001 ).Serum SP-A and SP-C levels in CWP patients were found to be significantly correlated with exposure to dust,dyspnea severity,FEV1％ predicted and DLCO％ predicted.Conclusion Serum SP-A and SP-C levels in CWP patients are closely associated with lung function,suggesting their role as candidate biomarkers for CWP.

Progress of Research on Nanopore-macromolecule Detection / 分析化学

After Human Gene Project, studying the kinetics of DNA translocation through a nanopore, and developing a novel fast DNA sequencing technology by using nanopore have become one of the hot in gene-research). This contribution provides an overview of nanopore macromolecular identification,including bionanopore and solid-state nanopore, while the perspective of these research are also summarized.

Direct generation of pluripotent stem cells from differentiated somatic cells / 生物工程学报

Embryonic stem (ES) cells have the unique capacity to proliferate extensively and maintain the potential to differentiate into advanced derivatives of all three primary germ layers. ES cell lines can also be generated from human blastocyst embryos and are considered promising donor sources for cell transplantation therapies for diseases such as juvenile diabetes, Parkinson's disease, and heart failure. However, as for organ transplants, tissue rejection remains a significant concern for ES cell transplantation. Another concern is the use of human embryos. One possible means to avoid these issues is by reprogramming the nuclei of differentiated cells to ES cell-like, pluripotent cells. This review discusses the potential of these strategies to generate tailor-made pluripotent stem cells and the role of transcription factors in the reprogramming process.

Effect of polylactic acid-O-carboxymethylated chitosan nanoparticles on immunological rejection in intraperitoneal porcine hepatocyte xenotransplantation of rats / 中国组织工程研究

BACKGROUND:Previous research has proved good therapeutic effect on the acute hepatic failure by the treatment of polylactic acid-O-carboxymethylated chitosan(PLA-O-CMC) nanoparticles-cultured porcine hepatocytes embedded in type I collagen.OBJECTIVE:To investigate the effect of PLA-O-CMC nanoparticles on immunological rejection in intraperitoneal porcine hepatocyte xenotransplantation for treatment of acute liver failure rats.DESIGN,TIME AND SETTING:Randomized control animal experiments were carried out at the Institute of Hepatobiliary Surgery and Laboratory of Nerve Regeneration in Nantong University from May 2005 to May 2006.MATERIALS:In situ recirculating collagenase perfusion method was used to isolate porcine hepatocytes.64 SD rats were intraperitoneally injected with D-galactosamine to induce acute hepatic failure models.METHODS:Totally 64 rats were divided into four groups:Model group received no intervention;Nano-collagen hepatocytes group was transplanted with PLA-O-CMC nanoparticles-cultured porcine hepatocytes embedded in collagen gel,which was then wrapped up using greater omentum;Porcine hepatocytes embedded in collagen gel(collagen hepatocytes group) and free porcine hepatocytes suspension(pure hepatocytes group) were transplanted into peritoneal cavity of SD rats,respectively.At 48 hours following the modeling,the porcine hepatocytes transplantations were performed and the number of transplanted cells was 5.0?107 hepatocytes in all groups.MAIN OUTCOME MEASURES:The serum interleukin-2,interferon-?,IgG and IgM levels of rats were determined at days 1,2,3,5 and 7.The pathological changes of transplants were observed under microscope at days 1,3 and 7.RESULTS:There were no significant differences in serum interleukin-2 and interferon-? levels of all groups during 7 days post-transplantation.Serum IgG levels increased with a peak at day 3 after hepatocytes transplantation,and then began to decline.Serum IgG levels in nano-collagen hepatocytes group were lower than those in collagen hepatocytes group and pure hepatocytes group at days 2 and 3(P

The changes of expression of apoptosis-related proteins of the transplantated hepatocytes after intraperitoneal transplantation in rats using porcine hepatocytes cultured with polylactic acid-O-carboxymethylated chitosan nanoparticles / 中国普通外科杂志

Objective To investigate the changes of expression of apoptosis-related proteins Bcl-2,Bax and Fas of the transplantated hepatocytes after intraperitoneal transplantation in rats using porcine hepatocytes cultured with polylactic acid-O-carboxymethylated chitosan nanoparticles.Methods Recirculating collagenase perfusion method was used to isolate porcine hepatocytes.At 48h after D-galactosamine intraperitoneal injection,5 mL polylactic acid-O-carboxymethylated chitosan nanoparticles-cultured porcine hepatocytes embedded in collagen gel(group A) and 5 mL porcine hepatocytes embedded in collagen gel(group B) were transplanted into peritoneal cavity of SD rats,respectively.The amount of transplanted porcine hepatocytes was 5.0?107 hepatocytes in two groups.The expression of Bcl-2,Bax and Fas in transplanted hepatocytes three days after transplantation was detected with immunohistochemistry.Results At 1,2 and 3d after transplantation,the rates of Bcl-2 positive cells in group A was significant higher than those in group B,whereas the rates of Bax and Fas positive cells in group A were significant lower than those in group B(P