Objective To investigate the changes in hydrogen sulfide(H_2S) level in plasma and myocardial tissues of doxorubicin-induced heart failure rats,and to study the role of H_2S in the development of doxorubicin-induced heart failure.Methods Male Wistar rats were randomly divided into 2 groups as follows:the doxorubicin group(n=12),in which 2.5 mg/kg of doxorubicin was injected intraperitoneal once a week for 10 weeks(total dose of 25 mg/kg);the control group(n=9),in which an(equivalent) volume of physiological saline was administered weekly for a total of 10 weeks.The observation of behavior was taken at the same time.Hemodynamic and echocardiographic measurements were obtained 10 weeks after treatment.Meanwhile,H_2S concentrations in serum and myocardial tissues were evaluated by modified sulfide electrode method.The changes of H_2S level between 2 groups were analyzed.Results The rats treated with doxorubicin showed inanimate behavior,decrease of the body temperature,activities and food intake,faster breathing,significant loss of weight,the cumulative mortality was 33%.Left ventricular systolic pressure(LVSP),difference of left ventricular pressure[△LVP=LVSP-left ventricular diastolic pressure(LVDP)] and left ventricular peak rate of contraction(+LV dp/dtmax),left ventricular peak rate of relaxation(-LV dp/dtmax)were significantly reduced in the group of doxorubicin rats(P

Objective To investigate the production of hydrogen sulfide (H2S) in rats with monocrotaline (MCT)-induced pulmonary hypertension(PAH).Methods Fourteen male Wistar rats were randomly divided into 2 groups (7 cases for each group):control group and MCT group.Rats in the MCT group were intraperitoneally injected with MCT (60 mg/kg) on day 1 while rats in the control group received only the same volume of 9 g/L saline.And then the conventional breeding was given for 21 days.Mean pulmonary artery pressure (mPAP) was evaluated via right cardiac catheterization procedure.The ratio of right ventricular mass (RV) and left ventricular plus septal mass (LV + SP) [RV/(LV + SP)] was calculated.The morphological change of pulmonary artery was observed by applying hematoxylin-eosin (HE) staining on the lung tissue paraffin section by measuring relative media thickness (RMT) and relative media area (RMA) of pulmonary aetery.H2S contents in serum and lung tissue rat were detected by using free radicals detector.The expression of cystathionine-γ-lyase (CSE),a key enzyme catalyzing endogenous H2S generaion,in lung tissue was detected by using Western blot method.CSE mRNA level in lung was detected by adopting the real-time polymerase chain reaction (RT-PCR) method.Results Compared with control group,mPAP of rats in MCT group was increased significantly [(49.31 ±3.67) mmHg vs (14.31 ±2.07) mmHg(1 mm Hg =0.133 kPa),P ＜ 0.01] and the ratio of RV/(LV + SP) was increased (0.43 ± 0.03 vs 0.21 ± 0.03,P ＜ 0.01),while RMT and RMA of pulmonary artery were enlarged [(43.46 ± 1.94) μm vs (13.16 ± 1.48) μm,P ＜ 0.01;(3 321.10 ± 318.20) μm2 vs (963.40 ± 127.26) μm2,P ＜0.01].The evaluation of microstructure of pulmonary artery showed that the vessel wall of pulmonary artery in control rats was thin and no inflammatory cell was observed around artery.However,the vessel wall of pulmonary artery in rats of MCT group was thickened and there was evident infiltration of inflammatory cells in perivascular area.Compared with control group,H2S contents in serum and lung tissue of rats in MCT group were markedly decreased [(9.28 ± 0.94) μmol/L vs (14.20 ± 1.21) μmol/L,P ＜ 0.01;(0.43 ± 0.08) μmol/g protein vs (0.87 ±0.17) μmol/g protein,P ＜0.01],while CSE protein and mRNA expression in lung tissue of rats in MCT group were downregulated (0.14 ± 0.02 vs 0.28 ± 0.09,P ＜ 0.01;0.84 ± 0.06 vs 1.12 ± 0.04,P ＜ 0.01).Condusion Endogenous H2S pathway is significantly downregulated in rats with monocrotaline-induced pulmonary hypertension.

Alkanes ; toxicity ; Animals ; Chromosome Aberrations ; Mice ; Mice, Inbred ICR ; Micronucleus Tests ; Mutagenicity Tests ; Mutagens ; Rats ; Rats, Sprague-Dawley ; Teratogens

Air Pollutants ; analysis ; Chromatography, High Pressure Liquid ; methods ; Urea ; analysis ; Workplace

Objective To investigate the regulatory effects of endogenous sulfur dioxide (SO2) on collagen accumulation in pulmonary arterial fibroblasts of rats and its mechanisms.Methods Primary rat pulmonary artery fibroblasts were used in the experiment and were divided into 3 groups:the control group,the L-aspartate-beta-hydroxamate(HDX) group and the HDX ± SO2 group.SO2 content of pulmonary artery fibroblasts supernatant was detected by adopting high performance liquid chromatography (HPLC).Collagen type Ⅰ and collagen type Ⅲ in pulmonary artery fibroblasts were determined by using immunofluorescence.Phosphorylation of Smad2/3,protein expression of matrix metalloproteinase (MMP)-13 and tissue inhibitors of MMP (TIMP)-1 were detected by using Western blot.One-way ANOVA was used for multiple group comparisons followed by Bonferroni test for each group.P ＜ 0.05 was considered as significant difference.Results Compared with control group,endogenous SO2 content in HDX group was significantly decreased [(14.30-± 0.48) μmol/L vs.(20.14 ± 0.49) μμmol/L,P ＜ 0.01],the level of Smad2/3 increased (1.03 ±0.31 vs.0.48 ± 0.20,P ＜ 0.01),protein expressions of MMP-13 and TIMP-1 in pulmonary artery fibroblasts were decreased (MMP-13:0.28 ± 0.06 vs.0.75 ± 0.11,P ＜ 0.01;TIMP-1:0.40 ± 0.05 vs.0.66 ± 0.20,P ＜ 0.01),and the ratio of MMP-13/TIMP-1 was decreased (0.71 ± 0.12 vs.1.23 ± 0.45,P ＜0.01).However,contents of collagen Ⅰ and collagen Ⅲ were significantly increased.Compared with HDX group,the level of Smad2/3 phosphorylation in HDX ± SO2 group decreased (0.57 ± 0.16 vs.1.03 ± 0.31,P ＜ 0.01),protein expression of MMP-13 and TIMP-1 upregulated (MMP-13:0.63 ± 0.06 vs.0.28 ± 0.06,P ＜ 0.01;0.59 ± 0.11 vs.0.40 ± 0.05,P =0.015),the ratio of M MP-13/TIMP-1 (1.10 ± 0.22 vs.0.71 ± 0.12,P =0.033) increased,but contents of collagen type Ⅰ and type Ⅲ were reduced obviously.Conclusions SO2 promotes the degradation of collagen and collagen accumulation in pulmonary artery fibroblasts of rats probably by inhibiting Smad2/3 signal pathway,increasing protein expression of MMP-13 and TIMP-1,and upregulating the ratio of MMP-13/TIMP-1.

Objective To investigate the Diels-Alder adducts from cell suspension cultures of Morus alba. Methods A variety of column chromatography (CC) including silica gel CC, Sephadex LH-20 CC, C18 CC, and semi-preparative HPLC were used to separate Diels-Alder adducts from cell cultures of M. alba. Their structures were identified by physicochemical properties and various spectroscopic experiments, including MS, NMR, and ECD. Results Eight Diels-Alder adducts were obtained from the ethyl acetate extract of M. alba, and determined as mongolicin H (1), morbilisin J (2), mongolicin F (3), mulberrofuran G (4), artonin D (5), kuwanon R (6), morbilisin C (7), and mulberrofuran E (8). Conclusion Compounds 1-8 are all Diels-Alder adducts and show medium cytotoxic activity, and compounds 1 and 2 are new compounds.

0.05).The different tilt angles impacted patients' fear psychology(?2=8.038,P=0.018).The order of the extent of children's fear psychology represented from low to high at the angle of 60?,70? and 80?,respectively.The extent of the children's fear psychology had positive correlation with the tilt angle(r=0.669,P=0.002).Conclusions The tilt test angle does not affect the positive rate of HUTT and the hemodynamics in children undergoing HUTT with angles from 60? to 80?.The children at the tilt angle 60? had less fear than at the angle of 70? or 80?.The 60? tilt angle of HUTT in children is recommended in the clinical practice.

Objective To investigate the etiology and clinical characteristics of pediatric pulmonary arterial hypertension(PAH) and improve its early diagnosis and treatment.Methods The clinical and echocardiogram data of all inpatients with PAH in Pediatric Department of Peking University First Hospital between May 1995 and May 2007 were retrospectively analyzed for age,sex,etiology,symptoms and echocardiographic measurement of pulmonary artery pressure.Data were divided into groups according to different etiology and statistics.Pulmonary arterial systolic pressure(sPAP) values estimated from the tricuspid regurgitant velocity by Doppler echocardiography were compared among different groups.Cases who were not belonged to the first category of the Venice Clinical Classification of pulmonary hypertension were not included.Results Totally 276 cases,168 boys and 108 girls were diagnosed to have PAH.Age ranged from 1 month to 17 years,median age was 9 months.Most of pediatric PAH was associated-PAH(267 cases,96.7%),while idiopathic PAH took a small part(9 cases,3.3%).Congenital heart disease-associated PAH(CHD-PAH) was predominant(245 cases,88.7%) and left to right shunt was the main lesion (217 cases,88.6%),while complex lesion-associated PAH comprised 28 cases(11.4%).Connective tissue disease associated PAH(CTD-PAH) was the second common among this group of pediatric PAH patients(19 cases,6.9 %).The incidence of PAH in systemic lupus erythematosus(SLE),juvenile rheumatoid arteritis and takayasu arteritis were 10.3 %(13/126),8.7%(4/46),15.4%(2/13),respectively.The other 3 cases of PAH were associated with portal hypertension(2 cases) and thalassanemia(1 case).The estimated sPAP from tricuspid regurgitant velocity in 8 cases with idiopathic PAH[(74.6?23.9) mmHg(1 mmHg=0.133 kPa)]was higher significantly compared with those of 33 cases of CHD-PAH [(58.0?19.7) mmHg ] and 12 cases of CTD-PAH [(49.6?18.9) mmHg] respectively(t=-2.052,-2.609 Pa

Whennearinfraredspectroscopyisappliedtoon-linemonitoringandcontroloftobaccoflavors,the variation in temperature can severely deteriorate the predictive performance of near infrared spectroscopic calibration models and results in a significant increases of the root mean square error value for the main constituents in syrup samples from 2. 4% to 29. 0%. In this paper, near infrared spectroscopy has been incorporated with an advanced calibration transfer method-loading space standardization to effectively eliminate the deteriorate effects of temperature variation on quantitative results and finally realize the fast and accurate on-line quantitative monitoring and control of tobacco flavors. The root mean square error value for the main constituents in syrup samples is successfully retained at a satisfying low level of 3 . 8%. The results of this paper will provide technical support for the preparation, preservation and use of tobacco flavors, and realize on-line process quality control of cigarettes.

'Bronze teeth' reflect the mechanical properties of natural teeth to a certain extent. Their mechanical properties resemble those of a tough metal, and the gradient of these properties lies in the direction from outside to inside. These attributes confer human teeth with effective mastication ability. Understanding the various mechanical properties of human teeth and dental materials is the basis for the development of restorative materials. In this study, the elastic properties, dynamic mechanical properties (visco-elasticity) and fracture mechanical properties of enamel and dentin were reviewed to provide a more thorough understanding of the mechanical properties of human teeth.
Biomechanical Phenomena ; Dental Enamel ; physiopathology ; Dentin ; physiopathology ; Humans ; Mastication ; Tooth ; physiopathology