Mechanism of aquaporin 4 in regulating 1,2-dichloroethane-induced blood-brain barrier permeability in mice / 中国职业医学

OBJECTIVE: To study the effect of aquaporin 4(AQP4) in regulating the permeability of blood-brain barrier(BBB) induced by subacute 1,2-dichloroethane(1,2-DCE) inhalation. METHODS: Specific pathogen free healthy CD-1 male Aqp4 genetically engineered mice(Aqp4~(+/+)and Aqp4~(-/-)) were randomly divided into control and low-, medium-and high-dose groups. The mice were exposed to 1,2-DCE at the dosages of 0.00, 100.00, 350.00 and 700.00 mg/m~3 for 6 hours per day for consecutive 28 days by systemic dynamic inhalation. After the end of 1,2-DCE exposure, the BBB permeability was evaluated by Evans blue staining. Real-time fluorescence quantitative polymerase chain reaction method was used to detect the mRNA expression of genes related to BBB tight junction protein(Tjp)1, Tjp2, Tjp3, claudin(Cldn)3, Cldn5, Cldn11, occludin(Ocln), matrix metalloproteinase(Mmp)2, Mmp9 and Na-K-Cl cotransporter-1(Nkcc1). RESULTS: The BBB permeability in mice showed significant change with 1,2-DCE dose and Aqp4 genotype(P<0.01). The BBB permeability of Aqp4~(+/+) genotype mice was higher in low-, medium-and high-dose groups than that of control group(all P values were <0.05). The permeability of BBB was lower in Aqp4~(+/+) genotype mice in the control group than that of Aqp4~(-/-) genotype mice in the same group(P<0.05), but BBB permeability was higher in Aqp4~(+/+) genotype mice in the three dose groups than that of Aqp4~(-/-) genotype mice in the same group(all P values were <0.05). The Cldn3 and Olcn mRNA relative expression in the brain cortex had statistical difference in mice with different genotype(all P values were <0.01). The mRNA relative expressions of Cldn3 and Olcn in the brain cortex were higher in Aqp4~(-/-) genotype mice than that of Aqp4~(+/+) genotype mice(all P values were <0.01). The relative mRNA expression levels of Tjp1, Tjp2, Tjp3, Cldn5, Cldn11, Mmp2, Mmp9 and Nkcc1 in the cerebral cortex of mice were not statistically significant in aspect of 1,2-DCE exposure dose and genotype(all P values were >0.05). CONCLUSION: Exposure to 1,2-DCE can increase BBB permeability in mice, and the mechanism may be associated with 1,2-DCE-induced down-regulation of Aqp4 and up-regulation of mRNA expression of the cerebral cortex TJP-related molecules Cldn3 and Ocln.

Acute 1,2-dichloroethane exposure induced differential gene expression of liver phaseⅠmetabolic enzymes in SD rats / 中国职业医学

OBJECTIVE: To investigate the effect of 1,2-dichloroethane(1,2-DCE) acute inhalation exposure on the differential gene expression of phase Ⅰ metabolic enzymes. METHODS: The specific pathogen free SD rats were randomly divided into control group(16 rats), low-and high-dose groups(24 rats in each group, half males and half females). Low-and high-dose group were given daily 600, 1 800 mg/m~(3 ) of 1,2-DCE, and the control group given the fresh air by dynamic inhalation for 8 hours per day for consecutive 7 days. After the end of exposure, the relative mRNA expression of cytochrome P450 2 E1(CYP2 E1), alcohol dehydrogenase(ADH1) and acetaldehyde dehydrogenase 3 alpha 1(ALDH3α1) in the liver tissue was detected by real-time fluorescence quantitative polymerase chain reaction. RESULTS: The relative expression of CYP2 E1 in male high-dose group was higher than that in male low-dose group and female high-dose group(P<0.05). The relative expression of ADH1 in male low-and high-dose groups was higher than that in male control group(P<0.05). The relative expression of ADH1 in male high-dose group was higher than that in male low-dose group and female high-dose group(P<0.05). The relative expression of ALDH3α1 in high-dose group was higher than that in control group and low-dose group(P<0.05). CONCLUSION: High dose 1,2-DCE could increase the gene expression of phase Ⅰ metabolic enzymes in rat liver. The 1,2-DCE has more obvious effect in male rats than in female rats.

Effect of different types of microplate and loading volumes on the detection results of multi-function microplate reader / 中国职业医学

OBJECTIVE: To evaluate the effect of different types of microplate and loading volumes on the detection results of multi-function microplate reader, and to optimize the analysis method. METHODS: A multi-function microplate reader was used to perform spectrum scanning on each of 5 detection holes of common and ultraviolet(UV) microplates, and the applicable detection wavelength range was those with light transmittance greater than 80.00%. The optical density measurement was carried out on each 12 detection holes of common and UV microplates at different wavelengths, then the matching of the detection holes was compared. Potassium permanganate was quantitatively analyzed by common microplate and UV microplate, while acetone was analyzed by UV microplate, and then detection limit, lower limit of quantitation(LLQ), accuracy and precision at different loading volumes and concentrations were calculated and compared. RESULTS: The shortest applicable analyzing wavelengths for common and UV microplates were(362±2) and(230±3) nm respectively, while the longest applicable analyzing wavelengths were both 1 000 nm. The light transmittance of UV microplate was higher than that of common microplate when the analyzing wavelengths were lower than 400 nm(P<0.01). The deviation and range of light transmittance of detection holes analyzed by UV microplates were smaller than that of common microplates when the analyzing wavelengths were 350-1 000 nm(P<0.05). The detection limit and LLQ of potassium permanganate by multi-function microplate reader was not associated with the types of microplate. The adding standard recoveries of potassium permanganate by UV microplate was higher than that by common microplate(P<0.05). The adding standard recoveries of potassium permanganate by loading volumes of 200 and 250 μL was lower than that by loading volumes of 150 μL(P<0.01), while adding standard recovery of acetone by loading volumes of 200 μL was lower than that by loading volumes of 150 μL(P<0.05). CONCLUSION: When using a multi-function microplate reader to detect chemicals, it is recommended to use UV microplate with wavelengths at the range of 230-1 000 nm, and loading volumes of 200-250 μL.

Efficacy and safety of Irbesartan Hydrochlorothiazide combined with Metoprolol as initial therapy in the treatment of heart failure in the elderly / 中华老年医学杂志

Objective To investigate the efficacy and safety of Irbesartan Hydrochlorothiazide combined with Metoprolol as initial therapy in the treatment of heart failure in the elderly.Methods A total of 128 elderly patients with heart failure admitted into our hospital from September 2017 to August 2018 were randomly divided into Group A(n=64)and Group B(n=64).Group A was treated with oral Irbesartan Hydrochlorothiazide tablets.Group B was treated with sustained-release oral Metoprolol tablets in addition to what was given in Group A.Therapeutic effects were compared between the groups.Results Compared with Group A,the effectiveness rate of group B was significantly improved(93.8％ vs.81.3％,x2 =4.571,P=0.033).There was no significant difference in brain natriuretic peptide (BNP),interleukin (IL)-12,left ventricular ejection fraction (LVEF),left ventricular end-systolic diameter(LVESD),or left ventricular end-diastolic diameter(LVEDD)between the two groups before treatment (P＞0.05).Compared with Group B,BNP,IL-12,LVEF,LVESD and LVEDD had significantly better profiles in Group A after treatment (P ＜ 0.05).The time-domain measurements of heart rate variability such as sequential five-minute R-R interval means(SDANN),standard deviation of the N-N interval(SDNN),percent of differences between adjacent RR intervals ＞50ms(PNN50)and root mean square of the successive differences(RMSSD)were higher in Group B than in Group A after treatment.No serious adverse reactions were observed in either group,and there was no significant difference in the incidence of adverse reactions between the two groups(4.7％ vs.7.8 ％,x2 =0.533,P =0.465).Conclusions Irbesartan Hydrochlorothiazide combined with Metoprolol as initial therapy has good clinical effects in treating elderly heart failure.It can not only improve the clinical symptoms of patients,but also ensure clinical medication safety.

Effect of 1,2-dichloroethane on learning and memory in NIH mice / 中国职业医学

OBJECTIVE: To investigate the effects of subacute systemic inhalation exposure of 1,2-dichloroethane(1,2-DCE) on learning and memory in NIH mice. METHODS: Forty-five specific pathogen free healthy 7-week-old NIH mice were randomly divided into control,low-dose and high-dose groups with 5 female mice and 10 male mice in each group. The mice were exposed to 1,2-DCE at dosages of 0. 00,100. 00 and 350. 00 mg/m3 for 6 hours per day for consecutive 28 days by dynamic systemic inhalation. The neurobehavioral tests of mice were performed before and after the first to fourth weeks of exposure using the Morris water maze test. RESULTS: There was no significant difference in body weight and swimming speed among the three groups of mice( P > 0. 05). The navigation experiment results showed that the escape latency of mice in both low-and high-dose groups were longer than that of the control group at the same time point(P < 0. 05) during 1-4 weeks after exposure. In the control group,the escape latency was shorter than that of the same group before exposure( P < 0. 05). The escape latency of high-dose group prolonged with the increase of exposure time,and in the 4 th week the escape latency was significantly higher than that of the same group before exposure( P < 0. 05).The experiment results of space exploration indicated that the first time of crossing platform in low-and high-dose groups were longer than that of the control group at the second to the fourth week( P < 0. 05). The target quadrant retention time and the number of crossing the platform in the low-and high-dose groups were lower than those in the control group( P <0. 05). CONCLUSION: Subacute inhalation exposure of 1,2-DCE can impair the learning and memory ability of NIH mice.The high-dose exposure may reduce learning ability in mice in a time-effect manner.

Effect of different anesthetics and blood sampling methods on blood routine test in SD rats and Kunming mice / 中国职业医学

OBJECTIVE: To compare the effects of different anesthetics and blood sampling methods on blood routine test results in experimental animals. METHODS: A total of 42 specific pathogen free( SPF) male Sprague Dawley( SD) rats and 59 SPF male Kunming( KM) mice were randomly divided into 4 groups( control group,ether group,chloral hydrate group and pentobarbital sodium group). Ether group animals were treated with ether inhalation anesthesia; animals in chloral hydrate group and pentobarbital sodium group were injected intraperitoneally with chloral hydrate or pentobarbital sodium. The control group received no anesthesia treatment. Blood samples were collected by different ways: orbital venous plexus,abdominal aorta or eyeball enucleation. White blood cell( WBC) count,red blood cell( RBC) count,platelet(PLT) count,hemoglobin(Hb) level and hematocrit(HCT) in blood samples were analyzed. RESULTS: The RBC count,Hb level and HCT of SD rats in pentobarbital sodium group were significantly lower than those in control group( P <0. 05). The HCT of SD rats in ether group was lower than that in control group( P < 0. 05). The WBC count of orbital venous plexus of KM mice was lower than that taken by eyeball enucleation in control group( P < 0. 05),but the WBC count of orbital venous plexus was higher than that taken by eyeball enucleation in chloral hydrate group( P < 0. 05). The RBC count,Hb level,HCT of KM mice in pentobarbital sodium group were significantly lower than those in control group(P < 0. 05). CONCLUSION: The anesthetic can affect the blood routine test results of experimental animals. Different blood sampling methods have effects on blood routine test results of KM mice.

Predicting the sensitizing potency of trichloroethylene by in vitro test / 中国职业医学

OBJECTIVE: To predict the sensitizing potency and optimal sensitization dose of trichloroethylene( TCE) by an in vitro skin sensitization test on a human acute monocytosis cell line( THP-1).METHODS: THP-1 cells were cultured in vitro and exposed to 2,4-dinitrochlorobenzene( DNCB),sodium dodecyl sulfate( SDS),tert-butylhydroquinone( tBHQ)and TCE for 24 hours.Flow cytometry was used to detect the expression of cell surface marker such as cluster of differentiation( CD) 86 and CD54,and the optimal dose range for sensitization detection was determined.With the relative fluorescence intensity( RFI),CD86 ≥ 150 and CD54 ≥ 200 as the standard,the sensitizing potency and optimal sensitization dose of TCE were predicted.RESULTS: The concentration range of reagents for sensitization test on THP-1 cells was the dose range at which the relative cell survival rate reached 75.0%-100.0%.DNCB at the doses of 20.83,25.00 and 30.00 μmol/L,tBHQ at the dose of 5.80 μmol/L,TCE at the doses of 8.33,10.00 and 12.00 mmol/L,can cause sensitivity.SDS was recognized as a negative sensitizer.The expression of CD86 and CD54 was the highest when the concentration of TCE was 8.33 mmol/L,which was considered as the best sensitization dose.CONCLUSION: The optimum sensitization dose of TCE is 8.33 mmol/L,which can provide the basis for dose design in future study of TCE sensitization pathways.

1,2-Dichloroethane-induced apoptosis in human astrocytes through mitochondrial pathway / 中国职业医学

OBJECTIVE: To explore the molecular mechanism underlying 1,2-dichloroethane(1,2-DCE) induced apoptosis by screening differentially expressed proteins in human astrocytes( HAs). METHODS: HAs were cultured in complete medium with 1,2-DCE at various concentrations of 0-80 or 0-40 mmol/L. After 24 hours,apoptosis of HAs was evaluated using flow cytometry and staining with annexin Ⅴ-fluoresce in isothiocyanate and propidium iodide. An AAH-APO-1-2 protein chip was used to screen differentially expressed proteins and quantitative real-time polymease chain reaction(qRT-PCR) was used to verify related differentially expressed genes(DEGs). RESULTS: At 1,2-DCE concentrations of0-80 mmol/L,the total apoptosis rate of HAs increased with 1,2-DCE concentrations in a dose-dependent manner( P <0. 01). Seven different kinds of proteins were screened out by apoptotic protein chip. Among them,the expression of insulin-like growth factor-binding protein( IGFBP)-1,IGFBP-4 and cytochrome C( Cyto C) were up-regulated,while the expression of P27,cysteine aspartic acid specific protease-3( Caspase-3),B-cell lymphoma-2 interacting mediator of cell death( BIM) and BH3 interacting domain death agonist( BID) were down-regulated compared with the control group. The result of DEGs verified by qRT-PCR showed that the expression of mRNA of IGFBP-1,IGFBP-4 and Cyto C at 1,2-DCE concentrations of 40 mmol/L was up-regulated. This result was in consistent with the trend of target expression in the protein chip. The mRNA expression of Caspase-3,BIM and BID was also up-regulated. CONCLUSION: 1,2-DCE induces apoptosis of HAs through mitochondrial pathway.

Analysis of cardiovascular risk factors in elderly patients with acute myocardial infarction / 中华老年医学杂志

Objective To analyze cardiovascular risk factors in senile patients with acute myocardial infarction(AMI).Methods Fifty-six elderly patients with AMI aged ≥65 years were enrolled as elderly group in our hospital from January 2014 to December 2015,and 76 elderly patients with AMI aged＜65 years during the same period were selected as a non-elderly group.Cardiovascular disease-related factors were analyzed in elderly patients with AMI.Results The proportions of complicated diabetes mellitus,hypertension,and dyslipidemia were higher in 56 elderly patient[29 cases (51.8％),41 cases(73.2％)and 37 cases(66.1％)]than in 76 non-elderly patients[12 cases,(15.8 ％),23 cases(30.3％)and 17 cases(22.4％),respectively,x2 =9.652,8.744,11.489;P=0.002,0.003,0.001].The proportion of male elderly group and non-elderly group were higher than those of female patients.The prevalence of cardiovascular disease was 87.5 ％ (14/16)in female elderly patients,which was 53.2％ (17/32)in female non-elderly patients(x2 =5.510,P =0.019).The incidence of a typical chest pain,heart failure and disturbance of consciousness after AMI attack was 26.8 ％ (15/56),64.3 ％ (36/56) and 23.3 ％ (13/56) in elderly group,respectively,which were higher than those in non-elderly group[39.5 ％ (3/76),31.6 ％ (24/76),5.26 ％ (4/76);x2 =3.965,9.075,5.365;P =0.047,0.003,0.021].Conclusions Acute myocardial infarction in elderly patients often coexists with hyperlipidemia,diabetes,high blood pressure and other risk factors.There is often no significant incentive before the onset of AMI in elderly patients.Its main clinical symptoms conclude atypical chest pain,heart failure and consciousness.