Research progress on toxic mechanisms of cadmium sulfide nanomaterials / 上海预防医学

Cadmium sulfide nanoparticles are a new type of semiconductor nanomaterials used in many applications. Studies have shown that cadmium sulfide nanoparticles have toxic effects on the reproductive system， liver， and kidney of the body， and the toxicities are affected by various factors. This paper summarized the current research on the toxicity of cadmium sulfide nanoparticles at home and abroad， and reviewed the latest research progress on the mechanisms of its toxic effects and influencing factors.

Preparation and drug release of curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres / 生物医学工程学杂志

Curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres (Cur-HP-β-CD-PiBCA) were prepared by one-step emulsification with α-isobutyl cyanoacrylate as materials, poloxamer 188 as emulsifier, and curcumin complex with hydroxypropyl-β-cyclodextrin (Cur-HP-β-CD) as drug prepared by kneading method. Effects of emulsifier and drug concentration on microspheres size and distribution, drug loading and encapsulation efficiency were investigated in detail. And the curcumin release of drug-loaded microspheres was also studied. Results showed that as the emulsifier concentration increased from 0.01% to 0.07%, particle size of the drug-loaded microspheres decreased while particle size distribution, drug loading and entrapment efficiency increased. The optimized concentration of surfactant was 0.05%. With increasing the concentration of drug from 0.03% to 0.07%, drug loading of Cur-HP-β-CD-PiBCA increased, but encapsulation efficiency decreased. Additionally, the results of drug release experiments revealed that the higher drug loading of Cur-HP-β-CD-PiBCA was, the lower cumulative release percentage was. Drug-loading of cumulative inclusions in HP-β-CD by PiBCA can improve its wettability, and increase the degree of dissolution and bioavailability.

Effects of nano-lead exposure on learning and memory as well as iron homeostasis in brain of offspring rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of nano-lead exposure on learning and memory and iron homeostasis in the brain of the offspring rats on postnatal day 21 (PND21) and postnatal day 42 (PND42).</p><p><b>METHODS</b>Twenty adult pregnant female Sprague-Dawley rats were randomly divided into control group and nano-lead group. Rats in the nano-lead group were orally administrated 10 mg/kg nano-lead, while rats in the control group were administrated an equal volume of normal saline until PND21. On PND21, the offspring rats were weaned and given the same treatment as the pregnant rats until 42 days after birth. The learning and memory ability of offspring rats on PND21 and PND42 was evaluated by Morris water maze test. The hippocampus and cortex s amples of offspring rats on PND21 and PND42 were collected to determine iron and lead levels in the hippocampus and cortex by inductively coupled plasma-mass spectrometry. The distributions of iron in the hippocampus and cortex were observed by Perl's iron staining. The expression levels of ferritin, ferroportin 1 (FPN1), hephaestin (HP), and ceruloplasmin (CP) were measured by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>After nano-lead exposure, the iron content in the cortex of offspring rats on PND21 and PND42 in the nano-lead group was significantly higher than those in the control group (32.63 ± 6.03 µg/g vs 27.04 ± 5.82 µg/g, P<0.05; 46.20 ±10.60 µg/g vs 36.61 ± 10.2µg/g, P<0.05). The iron content in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly higher than that in the control group (56.9 ± 4.37µg/g vs 37.71 ± 6.92µg/g, P<0.05). The Perl's staining showed massive iron deposition in the cortex and hippocampus in the nano-lead group. FPNl level in the cotfex of offspring rats on PND21 in the nano-lead group was significantly lower than that in the control group (3.64 ± 0.23 ng/g vs 4.99 ± 0.95 ng/g, P<0.05). FPN1 level in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly lower than that in the control group (2.28 ± 0.51 ng/g vs 3.69 ± 0.69 ng/g, P<0.05). The escape latencies of offspring rats on PND21 and PND42 in the nano-lead group were longer than those in the control group (15.54 ± 2.89 s vs 9.01 ± 4.66 s; 6.16 ± 1.42 s vs 4.26 ± 1.51 s). The numbers of platform crossings of offspring rats on PND21 and PND42 in the nano- lead group were significantly lower than those in the control group (7.77 ± 2.16 times vs 11.2 ± 1.61 times, P<0.05; 8.12 ± 1.51 times vs 13.0 ± 2.21 times, P<0.05).</p><p><b>ONCLUSION</b>n Nano-lead exposure can result in iron homeostasis disorders in the hippocampus and cortex of offspring rats and affect their learning and memory ability.</p>

Effect of lead exposure on permeability,secretion and transportation function of blood-cerebro-spinal fluid barrier of rats / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effects of lead exposure on the permeability,secretion and transportation function of blood-cerebro-spinal fluid barrier (BCB)of rats in order to provide the theo-rical basis for elucidating the mechanis m of lead induced neurotoxicity.MEHTODS 60 SPF SD rats were rando mly divided into 4 groups,including a control group and three doses lead exposed groups. Rat in the lead exposure groups were given drinking water containning 0.05%,0.1 % and 0.2% lead acetate (at dose of 80,160,320 mg·kg -1 )for 8 weeks.Laser scanning confocal microscopy was uti-lized to determine the lead content in seru m,cerebrospinal fluid (CSF)and choroid plexus sa mples. Morris maze was used to test learning and me mory.Fe moral artery perfusion of Evans blue (EB)and fluorescein sodiu m (NaFI)was performed to measure BCB permeability function.Confocal laser scan-ning was applied to detect junction adhesion molecule (JAM)and occludin protein expression in choroid plexus.ELISA was used to measure the concentration of transthyretin (TTR)and leptin in seru m and CSF.RESULTS The lead content in seru m,choroid plexus and CSF significantly increased,especially the lead level in CSF.Morris water maze data showed that escape latency of rat in lead acetate 160 and 320 mg·kg -1 group were 52 ±12,(89 ±19)s,respectively,longer than that of control group 〔(28 ±7)s, P<0.05〕.The ti mes across platform of rats in lead acetate 160 and 320 mg·kg -1 group were lower than that of control group(P <0.05).The NaFI content in CSF of rats in all lead acetate exposure groups were 0.94 ±0.09,1 .02 ±0.03 and (1 .08 ±0.18)mg·L -1 ,respectively,and were higher than those of control group〔(0.74 ±0.04)mg·L -1 〕;While the EB content in CSF of rat in lead acetate 160 and 320 mg·kg -1 group were higher than the control group(P <0.05),which indicated that lead acetate exposure at low dose can lead to the increase of permeability of BCB.Laser scanning confocal micro-scope i mages showed that the JAM protein expression of choroid plexus in lead acetate 160 and 320 mg·kg -1 group were 44.9% and 42.9% of the control group.Sa me decline was seen in terms of occludin expression.The TTR content of CSF of rats in lead acetate 80 mg·kg -1 group was (32.3 ± 1 1 .7)ng·g -1 protein,lower than that of the control group,and the difference was significant.This decline was also noted in lead acetate 160 and 320 mg·kg -1 group.The data of TTR in CSF suggested that the low dose lead acetate exposure can disrupt the BCB secretion function.The leptin levels in CSF of lead acetate 160 and 320 mg·kg -1 group were lower than that in the control group (P <0.05 ). CONCLUSION Lead exposure did disrupt the permeability,transportation and secretion function of BCB.Our data suggest that BCB dysfunction might be involved in the mechanis m of lead induced neurotoxicity.

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>

Dynamic changes of serum Clara cell protein and surfactant protein-D in rats with pulmonary fibrosis and their value in early diagnosis / 中国综合临床

Objective To detect the dynamic changes of the level of serum Clara cell protein(CC16)and surfactant protein-D(SP-D)in rats with pulmonary fibrosis induced by bleomycin and to evaluate their value in early diagnosis of pulmonary fibrosis. Methods Sixty Wistar rats were randomly divided into two groups, the control group and bleocin-induced pulmonary fibrotic group,with 30 rats in each group. The rats were killed at 1,3,7,14 and 28 days of treatment Pathology changes of lung tissue were observed by HE,Masson stain,alkaline hydrolysis to assess the hydroxyproline concentration of lung tissue, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum CC16 and SP-D. Results The hydroxyproline concentration of lung tissue in the pulmonary fibrotic group ((913. 1 ±69. 3) μg/g) were higher than those of the control group ((790. 5 ± 36. 8) μg/g) from the seventh day(P <0. 05). The levels of serum CC16 of the pulmonary fibrotic group((27. 34 ± 0. 32) μg/L) were lower than those of the control group((27. 85 ±0. 32)μg/L) since the third day(P<0. 05) ,and tended to decrease with the development of the disease. However,the levels of SP-D of the former group were always higher(P <0. 05), and tended to increase with the development of the disease. Conclusions The levels of serum CC16 and SP-D changed considerably in early-stage of pulmonary fibrosis, thus might be used as biomarker for early diagnosis and have some value for pathogenesis of pulmonary fibrosis.

Determination of N-ethyl morpholine in Air of Workplace by Gas Chromatography / 环境与健康杂志

Objective To establish a GC analytical method for the determination of N-ethyl morpholine in the air of workplace.Methods N-ethyl morpholine in the air of workplace was collected by silica gel tube, desorbed by ethanol, and according to The Criterion of Detection Methods for the Air of Workplace, the linearity range, precision, accuracy and limit of detection were determined by the GC under a certain experimental condition and the experiments of sampling efficiency , the desorption efficiency, penetrating capability and the stability of sample were carried.Results The linear range of N-ethyl morpholine was 0.025-20 mg/ml(r=0.999 8);Relative standard deviations were 3.2%-3.9%;the rates of recovery were 101.00%-102.43%(n=18), the limit of detection was 0.49 ?g/ml, the desorption efficiency was 96.10%-98.73%, the penetrating capability was 14.37 mg(100 g silica gel), and the content of samples were reduced less than 10% percent at the ninth day.Conclusion The method has higher sensitivity, better precision, accuracy, simple sampling, accurate and stable results.It can be used as an effective monitoring method to detect N-ethyl morpholine in the air of workplace.