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1.
Objective To investigate the mechanisms of apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase. Methods Human leukemia cell line K562 were exposed to indole-3-acetic acid (IAA) at 20, 40, 60, 80 or 100 mol/L and horseradish peroxidase(HRP) at 1.2 g/mL for varying times. MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect the arrest of cell cycle. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to measure apoptosis. 2, 7-dichlorofluorescin diacetate (DCFH-DA) uptake was measured to determine free radical by confocal microscope. Content of malondiadehyde (MDA) and activity of superoxide dismutase (SOD) were measured by biochemical methods. Results IAA/HRP initiated growth inhibition of K562 cells in a dose- and time-dependent manner. Flow cytometry revealed that cell cycle arrested at G1/G0 after 24 hours treatment. After 72 hours treatment, apoptotic rate of 100 mol/L IAA group increased to 43.9 %, which was 5 times that of control(P〈0.01). Content of MDA and activity of SOD increased respectively in treatments compared with control. Meanwhile, IAA/HRP stimulated the formation of free radical, which was increased by IAA concentration-dependently. Conclusion The combination of IAAand HRP can inhibit the growth of Human leukemia cell line K562 in vitro by inducing apoptosis which is associated with the increase of free radical. The combination of IAA and HRP might be a promising chemopreventive and chemotherapeutic agent against human leukemia.  相似文献   

2.
Objective To explore the correlation between endothelia cells activation and cytokines (ET-1, NO) levels in patients with pulmonary hypertension (PH), and to discuss their roles in the development of PH. Methods Twenty patients with simple ventricular septal defect (VSD) were chosen as controls, and 30 patients with PH were studied. Plasma levels of ET-1 and NO were measured by radioimmunoassay or colorimetric method. Before cardiopulmonary bypass was established, the specimens from right lung were fixed with formaldehyde solution, embedded with paraffin and stained by SP immunohlstochemistry. Intercellular adhesion molecule-1 (ICAM-1) expression was measured through the determination of the light density with computer imaging technology. Results Compared with that of the patients with simple VSD, the light density of ICAM-1 and plasma level of ET-1 increased in patients with PH; but plasma level of NO decreased (P〈0.05). Positive correlation was observed between ICAM-1 and ET-1/NO (P〈0.05). Conclusion Endothelia cells activation and imbalance of ET-1/NO might play an important role in the development of PH.  相似文献   

3.
Objective To study the serum iaminin (LN) and fibronectin (FN) changes in acute coronary syndromes (ACS), and explore the role of them in assessing the severity of ACS. Methods This study included 46 ACS patients [25 with acute myocardial infarction (AMI) and 21 with unstable angina (UA)], 51 stable angina (SA) patients and 47 people without CHD as controls. Serum levels of LN, FN, fibrinogen and blood fat were assessed. Coronary angiography were performed on 49 of them. Results The serum concentration of LN was lower in ACS patients [(85.20±27. 57)ng/mL], higher in SA patients [(116. 80 ± 28. 80)ng/mL] as compared to that in the control group [(100.06±29.96)ng/mL], with significant difference among the groups (P<0.05). No difference was found in FN among the three groups. However, the subgroup analysis in the group with ACS showed that the serum concentration of FN was significantly higher in UA patients [(229.60±121.39)μg/mL ], and lower in AMI patients [(108.31±47.12) μg/mL ]. The serum LN and FN concentration could respectively enter the logistic regression equations of ACS patients and US patients. Neither LN nor FN concentration was correlated with narrowing of coronary artery of angiography. Conclusion Serum LN and FN level may be a useful indicator for stability of atherosclerosis plaque in coronary arterial disease patients, but could not predict the extent of narrowing in coronary angiography.  相似文献   

4.
Objective To investigate the anti-tumor effect and mechanism of tamoxifen on rat C6 glioma cells. Methods C6 cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 3% fetal calf serum (FCS), and treated with tamoxifen of different concentrations, i.e. group A (1.25 μmol/L), group B (2.50 μmol/L), group C (5. 00 μmol/L), group D (10. 00 μmol/L), group E (20. 00 μmol/L) and control group (0. 00 μmol/L). Morphological changes, MTT assay and 5-bromo-2'-deoxyuriding labeling ratio were assessed. Apoptosis was observed by flow cytometry. Results C6 cells treated with different doses of tamoxifen for 24, 48, and 72 hours became irregular in shape, while cells treated with vehicle grew normally. MTT assay showed that tamoxifen did not suppress C6 cell growth until 72 hours after treatment. Seventy-two hours after treatment, there were significant differences in cell viable rate between group A versus groups C, D and E; so did group B versus group D as well as group E (P〈 0.05 ). BrdU incorporation assay indicated significant difference of BrdU labbled index (BrdU LI) among groups A, C, E and control group 48 hoers after treatment (P〈0.05). And the BrdU LI decreased with the increased concentration of tamoxifen. Flow cytometry (FCM) showed significant difference between treated group and control group at 24, 48, and 72 hours after treatment (P〈0.05). Conclusion Tamoxifen significantly suppresses the growth of C6 glioma cells in a time- and dose-dependent manner. The mechanism of tamoxifen suppressing C6 glioma cells may be inhibiting proliferation and inducing apoptosis. Therefore, tamoxifen can be a candidate as a chemotherapy agent for glioma.  相似文献   

5.
Objective To investigate the relationship between erythrocyte immune function and selenium (Se) level. Methods Forty-nine Kashin-Beck patients in endemic area aged 13- 1 6 years were divided into two groups and were orally given either selenized yeast or sodium selenite to provide 200 μg selenium per day for12 weeks. Erythrocyte selenium level, glutathione peroxidase activity, the rosette formation rates of red blood cells complement receptor typeⅠ (CR1), the immune function of red blood cells, and circulating immune complexes(CIC) were determined. Results After supplementing with selenium for 12 weeks, erythrocyte selenium level, glutathione peroxidase activity, the rosette formation rates of red blood cells CR1 were significantly increased. But the difference in rosette formation rates of IC and CIC content was not significant between before and after Se supplementation. Gonclusion The increase of the immune function of the erythrocyte by selenium-supplement may be one of the effective mechanisms for the prevention of Kashin-Beck disease.  相似文献   

6.
Retinal ganglion cells (RGCs) exhibit adaptive changes in response to sustained light stimulation, which include decrease in firing rate, tendency to shrink in receptive field (RF) size and reduction in synchronized activities. Gamma-aminobutyric acid-ergic (GABAergic) pathway is an important inhibitory pathway in retina. In the present study, the effects of GABAergic pathway on the contrast adaptation process of bullfrog RGCs were studied using multi-electrode recording technique. It was found that the application of bicuculline (BIC), a gamma-aminobutyric acid A (GABAA) receptor antagonist, caused a number of changes in the RGCs' response characteristics, including attenuation in adaptation-dependent firing rate decrease and the adaptation-dependent weakening in synchronized activities between adjacent neuron-pairs, whereas intensified the adaptation-dependent RF size shrinkage. These results suggest that GABAA receptors are involved in the modulation of the firing activity and synchronized activities in contrast adaptation process of the RGCs, whereas the adaptation-related RF property changes involve more complicated mechanisms.  相似文献   

7.
Electrolytic manganese residue(EMR) is generated from electrolytic manganese metal(EMM) industry, and its disposal is currently a serious problem in China.The EMR were calcined in the interval 100—900℃to enhance their pozzolanic activity and characterized by the differential thermal analysis-thermogravimetry(TGDTA), X-ray diffraction(XRD),infra-red(IR) and chemical analysis techniques with the aim to correlate phase transitions and structural features with the pozzolanic activity of calcined EMR.Prom the phase analysis and compressive strength results,it is found that the EMR calcined within 700—800℃had the best pozzolanic activity due to the decomposition of poorly-crystallized CaSO4 under the reducing ambient created by the decomposition of(NH42SO4.The appearance of reactive CaO mainly contributes to the good pozzolanic activity of EMR calcined within 700—800℃.The crystallinity of Mn3CO4 increases leading an unfavourable effect on the pozzolanic behaviour of EMR calcined at 900℃.The developed pozzolanic material containing 30%(mass fraction) EMR possesses compressive strength properties at a level similar to 42.5# normal Portland cement,in the range of 41.5—50.5 MPa.Besides,leaching results show that EMR blend cement pastes have excellent effect on the solidification of heavy metals.  相似文献   

8.
Objective To explore the effect of β-amyloid protein (Aβ) on S100β expression in rat hippocampus and its mechanisms. Methods At 7 days after bilateral stereotaxls injection of different dose of fibrillar Aβ25--35 and interluekin-1 receptor antagonist (IL-1ra) into the rat CA1 region, the learning and memory abilities of rats were tested with passive avoidance task. Amyloid deposition was detected by using Congo red staining technique. Nlssl staining and immunohlstochemical techniques were used to analyze the number of neurons, and GFAP and the S100β expression in hippocampal CA1 region , respectively. Results After fibrillar Aβ injection, the step-through latency of rats was significantly shortened compared to that of the control group. The GFAP positive astrocytes were found surrounding amyloid deposition. Neuronal loss occurred in the pyramidal cell layer of CA1 region. The number of S100β positive cells in Aβ-treated group was significantly increased compared with that in the control group. After IL-1ra injection, the number of S100β positive cells was significantly decreased. Conclusion Intrahippocampal injection of Aβ25 - 35 could cause similar pathologic changes of Alzheimer's disease. Aβ 25- 35 was capable of up-regulating S100β expression in a dose-dependent manner. The injection of IL-1ra could attenuate the effect of Alton S100β expression.  相似文献   

9.
Heart rate variability (HRV) is a noninvasive technique for autonomic nerve activity assessment and an indirect index of adrenergic cardiovascular drive. Renalase is the only known enzyme degrading circulatory catecholamines, participating in regulations of the cardiovascular and sympathetic nervous systems. This study aims at the relation between serum renalase and HRV indexes in dialysis patients. There were 14 hemodialysis (HD) cases, 16 continuous ambulatory peritoneal dialysis (PD) cases, and 16 healthy volunteers enrolled in this study. All the subjects underwent 24 h Holter testing by using a dynamic electocardiogram monitor system to determine HRV parameters, and serum renalase levels were measured. The standard deviation of normal to normal R-R intervals (SDNN, a measure of beat-to-beat variability), root mean square successive difference (RMSSD), and the proportion derived by dividing NN50 (the number of interval differences of successive normal to normal intervals greater than 50 ms) by the total number of NN intervals (pNN50) were determined to assess HRV. Both HD and PD patients presented increased maximum heart rate (Max-HR), minimum heart rate (Min-HR) and average heart rate (Ave-HR), and presented decreased SDNN, RMSSD and pNN50 relative to healthy controls. Serum levels of renalase were highly negatively correlated with Ave-HR (correlation coefficient r = -0.68, probability P 〈 0.01), while positively correlated with SDNN (r = 0.64, P 〈 0.01) in both the HD and PD groups. Serum level of renalase was positively correlated with 24 h urine volume (r = 0.73, P 〈 0.01) in PD patients. Renalase might be reciprocally related to HRV and inversely related to Ave-HR in dialysis patients, which will help to probe into renalase's physiology and may pave the way to explore renalase replacement therapy in patients with end stage renal disease (ESRD).  相似文献   

10.
We sought to validate magnetic resonance imaging(MRI) for documenting the effects of rosiglitazone on rabbit atherosclerosis and the possible mechanism by treatment on the lesions.24 New Zealand white rabbits were randomly divided into normal group, control group and treatment group.After 4 weeks, all rabbits underwent MRI.After examination, the number of circulating endothelial progenitor cells(EPCs) and level of lipid, glucose, nitric oxide(NO) and superoxide anion(O-2·) were measured.MRI demonstrated the regression of atherosclerotic lesions by rosiglitazone which has good correlation with histopathology.Treatment not only increased the level of EPCs and NO, but also raised the ability of inhibition of O2-·.MRI is a promising noninvasive technology to detect the effects of therapeutic interventions.Rosiglitazone slows the progression of atherosclerosis that may in part attribute to its improvement of mobilization of EPCs and the reduced oxidative stress.  相似文献   

11.
Objective To observe the toxic effect of the mixture of organophosphorus pesticide (MOP) on maternal rats and on the growth and development of their offspring. Methods Totally 40 Sprague-Dawley pregnant rats were randomly divided into three MOP dose groups and one control to which their offspring would be assigned, The experimental dosage of MOP and distilled water were administered orally starting on gestation day 15 and continued for 35 days. The physical development indices and the learning ability of F1 rats were measured during lactation. The pathological changes of uterus and liver of F0 rats were observed after weaning, while the weight ratio of uterus and some viscera to body of the F1 were examined. Results There were obvious changes of uterus and liver in the high-dose group of F0. The body-weight accretion of the F1 in high-dose group was obviously lower than that in control group (P〈0.05). Some of the MOP F1 rats development indices delayed significantly (P〈 0. 05), the learning ability decreased obviously, and the time of setting up memory prolonged (P〈0.05). The ratio of the uterus weight to bodyweight in the F1 MOP groups was significantly higher than that in control group (P〈0. 05). Oonclusion The experiment doses of MOP are proved to have significant reproductive toxicity on perinatai rats.  相似文献   

12.
Objecttive To observe the repaired effect of distinct source olfactory ensheathing cells (OECs) on spinal cord injury (SCI) rats. Methods These OECs were dissociated from olfactory bulb and olfactory mucosa of SD rats and transplanted to the injuried region of spinal cord injury rats. The function of nerve, motor evoked potential of hind legs and the histopathlogical diversities of injuried spinal cord were observed. Results The OECs grafts into the SCI area could survive longer time. The BBB scale, incubation stage of EP and histopathologic manifestations showed that the group with transplanted OECs regained more improvement in hindlimb than the control group. Conclusion The OECs of two sources have the same ability to regain and improve the axonal function which can promote axons regeneration of SCI.  相似文献   

13.
In order to improve the curving performance of the conventional wheelset in sharp curves and resolve the steering ability problem of the independently rotating wheel in large radius curves and tangent lines, a differential cou- pling wheelset (DCW) was developed in this work. The DCW was composed of two independently rotating wheels (IRWs) coupled by a clutch-type limited slip differential. The differential contains a static pre-stress clutch, which could lock both sides of IRWs of the DCW to ensure a good steering performance in curves with large radius and tangent track. In contrast, the clutch could unlock the two IRWs of the DCW in a sharp curve to endue it with the characteristic of an IRW, so that the vehicles can go through the tight curve smoothly. To study the dynamic performance of the DCW, a multi-body dynamic model of single bogie with DCWs was established. The self-centering capability, hunting stability, and self-steering performance on a curved track were analyzed and then compared with those of the conventional wheelset and IRW. Finally, the effect of coupling parameters of the DCW on the dynamic performance was investigated.  相似文献   

14.
Objective To study the relationships between cognitive impairment in patients with lacunar infarcts and quantitative CT measures and to determine the independent correlative factors of cognitive impairment. Methods Neuropsychological examination was conducted for 128 patients with acute lacunar infarct. Number, location, and volume of infarcts, cerebral atrophy index and severity of white matter lesions (WMLs) were measured and recorded. Results The number of lacunar infarcts in cognitive impairment (CI) group was significantly larger than that in cognitive normal (CN) group. Mean width of sulcns and sylvian fissure, index of frontal horn and ventricular-brain ratio (VBR) were significantly different in both groups. There were more patients with 3 grades or 4 grades WMLs in CI group (62%) than those in CN group (22%). The total volume of lacunar infarcts showed no statistically significant difference. Logistic regression analysis indicated that the number of lacunar infarcts in frontal subcortex and thalamus, the volume of infarcts in anterior periventricular white matter, width of cerebral sulcns and sylvian fissure were correlated with cognitive impairment respectively. Additionally, age and education were correlative factors of cognitive impairment in patients with lacunar infarct. Conclusion Correlative factors of cognitive impairment in patients with lacunar infarct are not merely one feature, but a combination of infarct features (number, location, and volume), cortical atrophy and host factors (age and education).  相似文献   

15.
Objective To investigate the interaction between fragile histamine triad (FHIT) and protein kinase C alpha (PKCα) in human non-small cell lung cancer tissues. Methods FHIT and PKC伪 double positive samples were screened by immunohistochemical staining from 13 human non-small cell lung cancer tissues. Co-immunoprecipitation was performed by using anti-FHIT and anti-PKCα. The immune precipitate was analyzed by SDS-PAGE and Western blot. Results Immune precipitate staining detection showed that 3 samples out of the 13 cases were double positive for FHIT and PKCα. FHIT protein was present in the immune precipitate of anti-PKCα while there was PKCα in the immune precipitate of anti-FHITmAb. Conclusion FHIT and PKCα exist as a complex in human non-small cell lung cancer tissues, which will provide a new route for studying the pathogenesis and immunotherapy of human non-small cell lung cancer.  相似文献   

16.
A new method for simulation technology of laneway engineering seamless excavation based on 3D geoscience modeling(3DGM)was proposed to overcome the deficiency in current research.The generalized triprism(GTP)data model was used as the basic modeling element in this method.The models of geological body were created by the method of rock pillar body partition(RPBP)modeling.The laneway engineering models were built with component method,while the corresponding triangles in sections were connected and transformed into tunnel GTP models.All the GTP models were converted into tetrahedron models based on the smallest vertex identifier(SVID).The simulation and spatial analysis of laneway engineering seamless excavation could be realized through the local hierarchical intersection(LHI)algorithm.The application case showed that the method was fast and effective,and it could meet the needs of design and spatial analysis for mine laneway engineering.  相似文献   

17.
PI (proportional-integral) control algorithm is applied to control WlP (work-in-progress) in a discrete manufacturing system, where the cascade control of PI controllers is presented. It is in the frequency domain that the PI controller is designed with constraints on sensitivity options to ensure the stability and robustness of its parameters. A case is evaluated on a motorcycle engine crankcase production system, whose simulation results confirm that demand fluctuations can be compensated by PI controllers under a normal demand. PI controllers also possess low sensitivity to the distribution of production times.  相似文献   

18.
Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectrlc complex (MMC) in the small intestine in vivo and explore the neural and endecrinal mechanisms of the effects. Methods Spragne-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY, phentolamine, nitro-L-arginine (L-NNA, the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results At all the three recording points, PYY lengthened the drde length of MMC [from (591.90±128.98)s to (999.25±216.59)s, P<0. 01] and lowered the frequency of phase Ⅲ [from (39.28±8.40) min-1 to (22.08±3.13) min-1 , P<0.01], amplitude of phase Ⅲ [from (0. 320±0.060)mV to (0. 179±0.030)mV, P<0.01], and the portion of phase Ⅲ over the whole circle length [from (28. 61 ± 5.84)% to (15.43 ±5.16)% , P<0.01]. Phentolumine had no influence on the role of PYY. Administered L-NNA combined with PYY, the percentage of phase Ⅲ increased [(42. 09±8.67)%] compared with that of control(P<0.01) and compared with that of PYY administered alone (P<0. 01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY my inhibit the interdigestive intestine motility through the none-adrenergic none-choUnergic tract, while the m-receptor tract and circulating motilin are probably not involved In the depressing effect.  相似文献   

19.
The study was to investigate thrombolysis in vitro with ultrasound, and to discuss effects of thrombolysis with ultrasound on the structure of erythrocyte and its safety threshold under different ultrasound intensity and exposure time. The structure of erythrocyte in thrombus was evaluated under light microscope. The relationship between the structure of erythrocyte in thrombus and ultrasound intensity and exposure time was obtained. The results showed that ultrasound eliminated the thrombus. According to the change of the structure of erythrocyte in thrombus and ultrasound intensity and exposure time, the effects of thrombolysis with ultrasound could be divided into three kinds of areas: the A, B, C area. The area A was the safe area, the area B was the relatively safe area, and the area C was the irreversible damage area. The study suggested that ultrasound intensity and exposure time had significant impact on the structure of erythrocyte. Stronger ultrasound intensity or longer exposure time could cause erythrocytes irreversible damage. It could accelerate thrombolysis and shorten the exposure time that the ultrasound intensity was little bit increased. The study of effects of thrombolysis with ultrasound on the structure of erythrocyte and its safety threshold were important for practical applications.  相似文献   

20.
On the assumption that the govermment has no anthority to intervene in the merger and separation of enterprises except to intervene in the export market by the protective tariff policy, but the enterprises can compete in international market in the form of merger or separation according to their own interests, the duopoly model was extended to a multiopoly model under Krugman- Brander framework, the effects of the variation of the number of enterprises on the enterprise' payoffs and trade policies were studied, and the promise and policy effect of flexible organization strategies of enterprises were analyzed. The obtained propositions show that the implementation of the enterprise organization strategies can offset the effect of other countries' strategic trade policy, and the rise of the number of enterprises in the industry is helpful to the formation of free trade. Furthermore, it is proved that if the rise of the number of enterprise in different countries causes the increase ( or decrease) of domestic producer surplus, then the domestic enterprises should take a form of separation ( or merger) to participate in the industry competition.  相似文献   

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