Objective To test whether sodium arsenite can induce in vitro reverse mutation of Salmonella typhimurium histamine-auxotroph mutant. Methods Ames test was carded out with Salmonella typhimurium strains TA97,TA98,TA100 and TA102 by standard method with or without the liver microsomal enzyme activation system (+S9,-S9). Results At concentrations of sodium arsenite from 500.00 to 5000.00 μg/plate, no colonies were seen on the plates of TA97,TA98,TA100 or TA102, with or without the presence of S9. At concentrations of sodium arsenite of 0.01,0.10,10.00 μg/plate and with the presence of S9, twice as many colonies grew on the plates of TA102 as the negative control(P<0.05). Without S9 activation,twice as many colonies grew on the plates of TA100 as the negative control(P<0.05)at concentrations of sodium arsenite of 1.00,10.00 μg/plate(P<0.05). The reverse mutation colonies induced by sodium arsenite in TA98 strain were twice as many as negative control group at concentrations of 0.01,0.10 μg/plate(P<0.05). There was no obvious increase of the strain clones in the other(P0.05). Conclusions With and without S9 activation, the doses of 500.00,5000.00 μg/plate sodium arsenite resulted in a toxic effect and a reduction of the revertants among the strain. At concentrations of 0.01～10.00 μg/plate, sodium arsenite exhibited mutngenesis effects.

Objective To investigate the association between arsenic(+3 oxidation state) methyltransferase (AS3MT) genetic polymorphism and susceptibility to endemic arsenism.Methods Polymerase chain reactionrestriction fragment length polymorphism-single strand conformation polymorphism(PCR-RFLP-SSCP) technology was performed to detect mutations of AS3MT gene intron 8 and exon 9 in genome DNA of the 79 cases and 110 controls.PCR products with abnormal band forms were further sequenced to find the types and sites of mutation.Chi-square test and multivariate Logistic analyses were conducted.Results The incidence of the 9149 base mutation(A→C) in AS3MT gene intron 8(AS3MT-9149) in case group(19.0％,15/79) was lower than that in control group (23.6％,26/110).The incidence of the codon 287 mutation(ATG→AT/CG) in AS3MT gene exon 9(AS3MT-287)in case group(10.1％,8/79) was lower than that in control group (11.8％,13/110).However,statistical analysis indicated no significant difference in both mutations between two groups[AS3MT-9149:odds ratio(OR) =0.59,95％ confidence interval(CI):0.26-1.31,P =0.195; AS3MT-287:OR =0.85,95％ CI:0.32-230,P =0.751].Conclusions There are no significant association between the genetic polymorphisms of AS3MT-9149,AS3MT-287 and the susceptibility to endemic arsenism.Similarly,due to small sample amount,we can not exclude the possibility that these gene polymorphisms are related to susceptibility to endemic arsenism.

Conus textile is a kind of highly toxic and abundantly existing conus in the South China Sea. The toxin from C.textile could act on sodium channels(δ-conotoxins)and calcium channels (ω-，ε-conotoxins), respectively. Their specific chemical structure and biological activity have attracted a lot of attention in recent years. This article briefly reviews their biochemical characteristics, isolation, gene cloning, biological and neuropharmacological activities, as well as their potential applications.

OBJECTIVE: To verify the relationship between THI and VAS scores in patients with sudden hearing loss and tinnitus in a prospective study. METHOD: Forty-four patients classified their tinnitus according to VAS and THI before and after treatment, and both scores were compared through the Pearson's correlation coefficient test and Nonparametric tests. RESULT: There was a correlation between VAS and THI scores in patients with sudden hearing loss and tinnitus. Tinnitus assessment scores were significantly reduced after treatment. Decreasing of THI and VAS scores were not depended on frequency and loudness of tinnitus and severity of deafness, but therapeutic effect of sudden sensorineural hearing loss. CONCLUSION THI and VAS scores are useful for assessment of tinnitus in patients with sudden hearing loss and tinnitus.
Audiometry ; Deafness ; Hearing Loss, Sensorineural ; complications ; Hearing Loss, Sudden ; complications ; Humans ; Prospective Studies ; Tinnitus ; complications

Objective To study the change and the significance of T-lymphocyte immune function in peripheral blood in population living in arsenic-contaminated area. Methods Fifty-three cases of patients with arsenism symptoms were selected into experimental group, inhabitants who had no chronic arsenism symptoms into control group in the endemic area of Shuocheng District, Shuozhou City, Shanxi Province in 2006. Vein blood samples were taken and analyzed with SAP assay to measure the percentage of CD3+ ,CD4+ and CD8+ T-cells. Results It was found that the percentage of CD3+, CD4+, and CD4+/CD8+ [(41.89 ± 11.58)%, (25.60 ± 9.05)% and 1.02 ± 0.41] in the experimental group was lower than that in the control group [(68.38 ± 7.23)%, (39.17± 4.28)% ,1.69 ± 0.56, t = 13.61,18.72,14.79, all P < 0.05], while there was no statistical differences of CD8+ [(25.30 ± 6.85)%] compared to the control group[(23.54 ± 8.35)%,t = 3.07,P > 0.05]. The gender-related effect of arsenic on CD4+ and CD8+ was found by multiple linear step regression analysis(t = - 3.05, - 4.30, all P < 0.05). In case group, there were no statistical differences in CD3+, CD4+, CD8+ and CD4+/CD8+[(40.65±10.06)%, (24.48 ± 6.29)%, (24.52 ± 8.16)%,0.98 ± 0.25] between males and females [(43.07±12.96)%, (26.77±3.12)%, (26.50 ±9.32)%, 1.07 ±0.41, t = - 0.76,3.05,0.30,2.10, all P > 0.05]. Conclusions The immune function of T-lymphocytes of patients with chronic arsenism has been suppressed. It is of active significance to detect T-lymphocyte subpopulation in peripheral vein in patients with chronic arsenism aiming at estimating the function of cell immune and providing early diagnosis index.

Objective To observe the effect of low arsenic sub-chronic exposure on blood routine test index in rabbits to pave a way for screening early injury of the low arsenic exposure. Methods Twelve healthy male rabbits were randomly divided into four groups. They were administrated with As at the concentration of 0(control), 10, 50 and 250 μg/L in the drinking water. Blood samples were collected from the vein of the ear edge in 8 weeks, and blood test routine including leukocyte (WBC), lymphocyte (LYM), lymphocyte percentage (LYM%), neutrophil (GRA), neutrophil percentage (GRA%), monocyte (MON), monocyte percentage (MON%), red blood cell (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration(MCHC), RDW, platelets(PLT), mean platelet volume(MPV), platelet hematocrit(PCT) and platelet distribution width (PDW), were detected by the ABX-60 hemocyte analyzer. Results Compared with the control group, the WBC, GRA and GRA% increased in 0, 50 and 250 μg/L groups, but there was no significance(P > 0.05). PLT and MPV had a statistical significance in 4 groups(F = 4.07,4.20, all P < 0.05). Compared with the control group[(292.00±16.97)×109/L, (7.10±0.99)fL], PLT decreased in the 250 μg/L group [(221.33±22.50)×109/L] and MPV decreased in the 50μg/L group [(5.57±0.46)fL] significantly (P < 0.05). The other index didn't change obviously. Conclusions Sub-chronic low level arsenic exposure may lead to the change in the blood system. The blood routine test may be considered for early injury of the arsenic poisoning.

Objective To observe the sub-chronic effects of low doses of arsenic poisoning in rabbits exposed to different periods on some of the serum enzymes and biochemical indicators, and to provide the basis for screening of meaningful hematologic indicators for early diagnosis of arsenic poisoning. Methods Twelve adult rabbits,weighing 2.0 - 3.5 kg, were randomly divided into four groups, 3 in each group, and they were fed with drinking water containing sodium arsenite 0(control),0.01,0.05,0.25 mg/L, respectively. Serum alanine aminotransferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), γ-glutamyl transacylase (y-GT), total protein(TP), albumin(ALB), globulin(GLP), and ALB/GLP of rabbit were measured by SYSMEX-180 automated biochemistry analyzer after 8 weeks and 12 weeks exposure. Results The results showed that ALT in 0.05 mg/Lgroup of 12 week[(60.00 ± 4.14)U/L]increased significantly compared with the control[(41.50 ± 2.12)U/L, P ＜0.05];AST in 0.25 mg/L group of 8 week and 12 week[(46.50 ± 3.21 ), (52.33 ± 3.81 )U/L]increased significantly compared with the control[(21.33 ± 3.53), (29.50 ± 3.23 )U/L, all P ＜ 0.05];ALP in 0.05 mg/L and 0.25 mg/L group of 12 week [(78.68 ± 4.85 ), ( 103.00 ± 7.83 ) U / L]increased significantly compared with the control [(45.50 ± 5.50)U/L, all P ＜ 0.05];γ-GT in 0.05 mg/L group of 12 week[(19.33 ± 7.50)U/L]increased significantly compared with the contro1[(8.50 ± 3.53)U/L, P＜ 0.05]. TP, ALB, GLP, ALB/GLP of different groups of 8 week and 12 week were not significantly different statistically(F= 0.77,0.02,0.16,3.14 and 0.51,0.29,0.41,0.52, all P ＞ 0.05). Conclusions Zero point zero five mg/L and higher doses of sub-chronic arsenic exposure has some major damage to the liver. Compared with other serum enzymes and the biochemical indexes, serum AST is a early sensitive indicator of liver injury of the arsenic poisoning.

Objective To explore the DNA damage in peripheral blood lymphocytes of rats exposed to sodium arsenite. Methods Thirty-two Wistar rats, weighing 180 - 200 g, equal male and female, were randomly divided into 4 groups, 8 in each group. Sodium arsenite 0(control) ,0.05,0.15,0.45 mg/L were given through drinking water for 30 days. Body weight and drinking water consumption were measured every day. Blood were collected and DNA damage in peripheral blood lymphocytes was examined by single cell gel electrophoresis.Results The increase of body mass[( 121.00 ± 38.57), ( 120.62 ± 42.80), ( 125.38 ± 48.68)g]and water intake [(36.9 ± 6.2), (37.9 ± 5.8), (39.3 ± 4.2)ml/d]in 0.05,0.15,0.45 mg/L sodium arsenite groups were compared with the control group[( 119.25 ± 47.27)g, (38.4 ± 5.1 )ml/d], and the difference were not significant (F = 0.040,0.828, all P ＞ 0.05). The tail ratios[46.25%(185/400) ,57.00%(228/400),64.00%(256/400)], tail lengths [(32.89 ± 17.18), (58.74 ± 36.28), (77.55 ± 35.73 ) μm]and tail moments [(6.29 ± 3.74), ( 11.20 ± 9.64),(17.30 ± 12.60)μm]in 0.05,0.15,0.45 mg/L sodium arsenite groups were significantly higher than those of the control group[39.25%(157/400), (18.73 ± 15.83),(2.61 ± 1.05)μm, all P ＜ 0.01], and the tail ratios,tail lengths and tail moments in lymphocytes increased with increased doses of arsenic concentration. Conclusions Low doses of arsenic exposure can induce DNA damage in peripheral blood lymphocytes of rats.

ObjectiveTo study the effect of 8 Hz infrasound on the expression of 5-hydroxytryptamine (5-HT) in rats' hippocampus and temporal cortex.Methods140 male SD rats were randomly divided into the control group, and experimental groups that exposed to infrasound of 8Hz,90dB,100dB and 130dB for 1,7,14,21,28,35,42 days. Experimental groups were exposed to infrasound for 2 hours each day. The control group was only placed in the infrasonic storehouse but without infrasound. Rats' brains were taken as soon as the exposure finished and strained by immunohistochemistry. The content of 5-HT in hippocampus and temporal cortex was detected under an optical microscope.ResultsInfrasound groups had less expression of 5-HT in hippocampus and temporal cortex than the control group (P<0.01), and the least were at the 28th day for 90 dB and 100 dB groups and the 21st day for 130 dB group. Then the expression of 5-HT had an increase in each group.ConclusionThe deceased expression of 5-HT in rats' hippocampus and temporal cortex could result from infrasound of 8 Hz. Rules of change are related to the parameter of infrasound and the 130 dB 8 Hz infrasound can induce greater changes compared with that of 100 dB and 90 dB.

OBJECTIVETo investigate the role of multidrug resistance-associated protein 2 (MRP2) in the hepatic cell membrane of rats.

METHODSThirty healthy Wistar rats were divided randomly into six groups based on time of administration (2 w, 4 w, 6 w) of 20 mg/kg of sodium arsenite, and their corresponding control groups. Animals were administered every other day. Arsenic content in blood and bile were detected by atomic absorption spectroscopy (AAS), and the expression of MRP2 in the membrane of hepatocyte by Western blotting was determined.

RESULTSTotal arsenic levels (including organic arsenic and inorganic arsenic) in blood and bile were significantly higher than control groups (P < 0.05) at all three different time points, especially in 2 w and 4 w group (16.8 and 13.8 fold greater than that in control). The expression of MRP2 increased 36.61%, 32.36%, 12.73% more respectively in 2 w, 4 w, 6 w groups than those in control groups (P < 0.05). The expression of MRP2 was correlated with total arsenic content in bile (r = 0.713, P < 0.05).

CONCLUSIONSBile is one of the major routes for the excretion of arsenite and its metabolites, and the overexpression of MRP2 may play an important role in the bile excretion of them at early stage.

Animals ; Arsenic Poisoning ; metabolism ; Arsenites ; pharmacology ; Bile ; metabolism ; Hepatocytes ; drug effects ; metabolism ; Liver ; metabolism ; Membrane Transport Proteins ; genetics ; metabolism ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar