Chemical constituents from Polygonum hydropiper / 中成药

AIM To study the chemical constituents from Polygonum hydropiper L..METHODS The petroleum ether,ethyl acetate and n-butanol fractions of 95％ ethanol extract from P.hydropiper were isolated and purified by silica,Sephadex LH-20 and recrystallization,then the structures of obtained compounds were identified by spectral data.RESULTS Thirteen compounds were isolated and identified as β-sitosterol (1),aniba dimer A (2),succinic acid (3),quercetin (4),gallic acid (5),daucosterol (6),quercetin-3-O-β-D-glucoside (7),kaempferol-3-O-β-D-glucoside (8),quercetin-3-O-β-galactoside (9),kaempferol-3-O-β-galactoside (10),stigmast-4-ene-3β,6a-diol (11),fumaric acid (12),ellagic acid (13).CONCLUSION Compounds 11 and 12 are isolated from genus Polygonum for the first time,compounds 2,8,10 and 13 are first obtained from this plant.

Biomechanical mechanism and quantitative assessment indices for vulnerable carotid plaques / 医用生物力学

The rupture of carotid atherosclerotic plaques and thrombosis are the main risk factor for ischemic stroke. The risk of carotid plaque rupture is closely related with the local biomechanical situation, morphology, components and biological activity of the carotid plaques. In this article, the research progress on methodology for studying carotid stenosis biomechanics, the risk of vulnerable plaque rupture in carotid stenosis and decision-making in clinical treatment, the animal modeling and experiment on vulnerable carotid plaques, and the components and biological activities of carotid plaques was summarized, the existing problems were analyzed, and the in-depth prospective about the biomechanical mechanism and quantitative assessment indices for vulnerable carotid plaques was also proposed, expecting to provide necessary theoretical guidance for feasible decision-making on the treatment of carotid stenosis.

Application of computational fluid dynamics in clinical treatment of cerebral aneurysms / 医用生物力学

In recent years, computational fluid dynamics (CFD) has been widely used in fundamental and clinical researches of cerebral aneurysms. The research direction involves: ① the hemodynamic risk factors associated with initiation, evolution and rupture of cerebral aneurysms, ② the assessment of flow field changes in cerebral aneurysms after the implantation of coils and stent as well as the effect of such endovascular treatment by establishing the patient-specific models. This review elaborates the research progress in hemodynamics of cerebral aneurysms from 3 aspects: the development of CFD models, the morphological and hemodynamic parameters for rupture risk assessment of aneurysms and the role of CFD in the endovascular treatment of cerebral aneurysms.

Inhibition of butanol extract from Paris polyphylla var. yunnanensis against Candida albicans biofilm formation / 中草药

Objective: To investigate the effects of butanol extract from Paris polyphylla var. yunnanensis (BEPP) on the biofilm formation of Candida albicans in vitro. Methods: Microdilution method was used to determine the minimum inhibitory concentration (MIC). XTT assay was used to determine the SMIC80. Flat band method was used to protract the time-kill curve. Scanning electron microscopy (SEM) was used to observe the morphological changes of the biofilm. Confocal laser scanning microscopy (CLSM) was used to detect the thickness of the biofilm. The quantification real-time PCR (qRT-PCR) was used to detect the expression changes of genes (EAP1, MP65, and SUN41) of the biofilm cells. Results: The MIC of BEPP against C. albicans strains was determined as 32-128 μg/mL. The SMIC80 of BEPP against the biofilm of C. albicans strains was determined as 128-512 μg/mL. Time-sterilization curve results indicated that BEPP had a promise bactericidal effect. SEM results showed that the formation of C. albicans biofilm was inhibited by BEPP, and the morphology of biofilm was also affected by BEPP. The thickness of C. albicans biofilm was reduced by BEPP according to CLSM results. Furthermore, qRT-PCR results indicated that expressions of EAP1, MP65, and SUN41 were significantly down-regulated by BEPP. Conclusion: Our results demonstrate that BEPP inhibits the biofilm formation of C. albicans in vitro.

Effect of andrographolide on quorum sensing and relevant virulence genes of Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of andrographolide (AG) on quroum sensing (QS) and relevant virulence genes of Candida albicans.</p><p><b>METHOD</b>Gas-chromatography-mass spectrometry (GC-MS) was applied to detect the changes in the content of farnesol and tyrosol in C. albicans intervened by AG. The real-time quantitative PCR (qRT-PCR) was adopted to inspect the expressions of relevant virulence genes such as CHK1, PBS2 and HOG1 regulated by QS.</p><p><b>RESULT</b>At 2 h after the growth of C. albican, the farnesol and tyrosol secretions reduced, without notable change after intervention with AG. The secretions were highest at 12 h and decreased at 24 h. After the intervention with different concentrations of AG, the farnesol content reduces, whereas tyrosol increased, indicating a dose-dependence, particularly with 1 000 mg x L(-1) AG. qRT-PCR revealed that 1 000 mg x L(-1) AG could down-regulate CHK1 by 2.375, 3.330 and 4.043 times and PBS2 by 2.010, 4.210 and 4.760 times, with no significant change in HOG1.</p><p><b>CONCLUSION</b>AG could inhibit the farnesol secretion, promote the tyrosol secretion and down-regulate QS-related virulence genes CHK1 and PBS2 expressions.</p>

Effect of Huanglian Jiedu decoction in combination with fluconazole on ergosterol of fluconazole-resistant Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of ethyl acetate extract of Huanglian Jiedu decoction (EAHD) , alone and in combination with fluconazole (FLZ) on FLZ-resistant Candida albicans.</p><p><b>METHOD</b>The minimum inhibitory concentrations (MIC) and sessile MIC80 (SMIC80) of EAHD and FLZ to FLZ-resistant C. albicans were determined by CLSI M27-A3 microdilution method, and the synergy of EAHD combined with FLZ were examined by the checkerboard microdilution assay. Agar plate-method was adopted to observe the rate of antifungal activity according to time-kill curve. HPLC and qRT-PCR were utilized to evaluate the changes of ergosterol content and expressions of related genes, respectively.</p><p><b>RESULT</b>MICs of EAHD ranged from 156 to 1,250 mg · L(-1), those of FLZ from 256 to above 2,048 mg · L(-1) with FICI approximate 0.066 in combination; SMIC80 of EAHD were higher than 1,250 mg · L(-1), SMIC80 of FLZ were higher than 512 mg · L(-1) and up to above 2,048 mg · L(-1). Combination group also showed synergy effect except one group showing addition effect. The results of T-K experiment also confirmed obviously fungicidal effect when treated for 12 h. When compared with control groups, the ergosterol was reduced 85% and 50% in the treatments of combination and EAHD alone by HPLC, respective- ly. The expressions of ERG1, ERG2, ERG6, ERG7 and ERG11 were upregulated, and ACS1, ACS2, MET6 were downregulated when exposed to FLZ. The expressions of the above genes were downregulated by treatment of EAHD. The expressions of ERG2, ERG6, ERG11 were upregulated, while ERG1, ERG7, ACS1, ACS2, MET6 were downregulated in combination group.</p><p><b>CONCLUSION</b>The combination of EAHD and FLZ exhibited synergy against FLZ-resistant C. albicans through decreasing the synthesis of ergosterol, and resulting in the breakage of cell membrane.</p>

Simulation study on expansion process of vascular stent in realistic stenosis model / 医用生物力学

Objective To study the deformation and mechanical characteristics during expansion process of vascular stent in realistic stenosis model, so as to provide scientific references for interventional treatment and stent design. Methods The carotid vessel model and plaque model of patient were built by using 3D reconstruction method, and the stent model with I-shaped link was established by using Pro/E; ABAQUS/Standard was used to simulate the radial expansion (the first stage) and radial contraction (the second stage) of the stent in real stenosis model, and a realistic model of blood vessel with plaque was also established to make contrast test. Results In the first stage, radial expansion of the stent was formed. The maximum contact area was generated between the outer surface of the stent and the inner surface of the plaque/arterial wall, and the maximum stresses on the stent, plague and arterial wall were 515.000, 2.482, 1.053 MPa, respectively. In the second stage, the radial contraction of the stent resulted in “dog-bone” effect. Many gaps between the stent and vessel wall was formed, and the maximum stresses on the stent, plague and arterial wall were 464.500, 0.954, 0.316 MPa, respectively. In contrast test, the maximum stresses on stenotic vessel and stent were 0.9, 414.1 MPa in the second stage. Conclusions Compared with the model in contrast test, the stenosis model differentiating the component of vascular tissues is more consistent with the real situation of stenotic vessels, by more truly showing deformation and mechanical characteristics of the stent and blood vessel. The stent causes the maximum damage to plaque and inner wall of blood vessel in the first stage, while “dog-bone” effect of the stent is an important influencing factor that results in the gaps between the stent, plague and blood vessel. These research findings may provide significant guidance for selecting stent in interventional treatment and improving stent design.

Evaluation of cardiovascular health based on pulse wave detection technology / 医用生物力学

There contains so much physiological/pathological information in pulse wave, which can reflect the early changes in cardiovascular function parameters. Therefore, it would be valuable to quantify the information revealed by pulse wave as important reference for cardiovascular diseases. In this review, the relationship between physiological/pathological information in cardiovascular system and pulse wave was described from the viewpoint of pulse wave formation mechanism, and to explain how the non-invasive detection indexes supplied by pulse wave could be applied in clinical use by analyzing the waveforms. Cardiovascular health evaluation index established by physiological/pathological information from cardiovascular system with pulse wave theory was also discussed. The development of non-invasive detection methods for cardiovascular system based on pulse wave theory can contribute to cardiovascular health care and provide important reference for the early detection, early prevention and early treatment of cardiovascular diseases. Besides, the non-invasive detection method can simplify the process of clinical testing and reduce the costs so as to achieve health assessment on cardiovascular diseases timely and reduce the mortality and disability rates.

Inhibitory effects of butyl alcohol extract of Baitouweng decoction on virulence factors of Candida tropicalis / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of butyl alcohol extract of baitouweng decoction (BAEB) on the fungal cell surface hydrophobicity (CSH), filamentation and biofilm formation of Candida tropicalis.</p><p><b>METHOD</b>Gradual dilution method was used to determine the MIC. XTT assay was applied to determine the SMIC80. Time-Kill assay was employed to draw the Time-Kill curve. The water-hydrocarbon two-phase assay was used to measure the cell surface hydrophobicity. Scanning electron microscopy (SEM) was applied to observe the morphological changes of the biofilm. Confocal laser scanning microscopy (CLSM) was applied to determine the thickness of the biofilm. The quantification real-time PCR (qRT-PCR) was used to detect expression changes of releated genes (UME6, ALST3 and NRG1). result: The MICs of BAEB against C. tropicalis strains are determined as 64-128 mg x L(-1). The SMIC80 s of BAEB against the biofilm of Candida tropicalis strains are determined as 256-512 mg x L(-1). Time-Kill curve results indicate that BAEB has a promise fungicidal effect at 256 and 512 mg x L(-1). SEM results shows that 512 mg x L(-1) BAEB can inhibit the formation of C. tropicalis biofilm on Silicone catheter, and the morphology of biofilm is also affected by BAEB. The thickness of C. tropicalis biofilm is reduced by BAEB according to CLSM results. Furthermore, qRT-PCR results indicate that expression of UME6 and ALST3 are significantly down-regulated by BAEB 256,512 mg x L(-1), and NRG1 is not affected by BAEB.</p><p><b>CONCLUSION</b>BAEB inhibits effectively the CSH, filamentation and biofilm formation of VVC strains of C. tropicalis.</p>

Study on inhibitory effect of different extract fractions from longdan xiegan decoction on biofilms of Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the inhibitory effect of different extract fractions from Longdan Xiegan decoction on biofilms of Candida albicans, and discuss its possible mechanism.</p><p><b>METHOD</b>The micro-dilution method and the XTT reduction assay were adopted to explore the antifungal activity of different extract fractions from Longdan Xiegan decoction and detect the inhibitory effect of different extracts on biofilms of C. albicans. The expression quantity of the adhesion related gene ALS1 and hypha formation SUN41 were detected by qRT-PCR.</p><p><b>RESULT</b>The MICs of extracts from Longdan Xiegan decoction, including petroleum ether, water, butanol, methanol and ethyl acetate, against C. albicans were > 1 000, > 1 000, > 1 000, 125, 125 mg x L(-1). The SMIC50 against biofilms of C. albicanswere > 1 000, > 1000, > 1 000, 500, 500 mg x L(-1). The SMIC50 were > 1 000, > 1 000, > 1 000, > 1 000 and 1 000 mg x L(-1). 1 000 mg x L(-1) ethyl acetate extracts could considerably inhibit the expression of the adhesion related gene ALS1 and hypha formation SUN41.</p><p><b>CONCLUSION</b>The ethyl acetate extract showed the greatest activity against Candida albicans biofilms.</p>

Effect of andrographolide on Candida albicans biofilm dispersion / 中国中药杂志

Along with the increase in fungal infections, Candida albicans prevention and control become the focus of anti-fungal infection at present. This study aims to discuss the effect monomer andrographolide (AG) on C. albicans biofilm dispersion. In the experiment, micro-well plates and medical catheter pieces were used to establish the C. albicans biofilm model. It was discovered by XTT assay and flat band method that 1 000, 500, 250 mg x L(-1) AG could impact the activity of C. albicans biofilm dispersion cells. The morphological structures of residual biofilms on catheter pieces were observed with scanning electron microscopy, which showed that 1 000, 500, 250 mg x L(-1) AG could induce C. albicans biofilm dispersion in a dose-dependent manner, and the dispersed cells were dominated by the yeast phase. According to the real-time fluorescence quantification PCR (qRT-PCR) test, AG could up-regulate HSP90 expression and down-regulate UME6 and PES1 expressions. This study demonstrates that AG could induce C. albicans biofilm dispersion to some extent.

Effect of andrographolide derivative Yanhuning on in vivo Candida albicans biofilms in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of andrographolide derivative Yanhuning (YHN) on Candida albicans biofilms in rats.</p><p><b>METHOD</b>The rat C. albicans biofilms subcutaneous catheter model was established by intraperitoneally injecting YHN (40, 20, 10, 5, 2.5 mg x kg (-1)), with the FLC (80 mg x kg(-1)) positive group as the control group. After 7 d, CFU counting and XTT assay were used to evaluate the effect of YHN on C. albicans biofllms in vivo. Scanning electron microscopy (SEM) was applied to observe the morphological changes in rat biofilms intervened by YHN. The real-time fluorescence quantification PCR was adopted to detect expressions of C. albicans adhesion-related genes, such as ALS1, ALS3, HWP1, EAP1 and MP65.</p><p><b>RESULT</b>The YHN group showed much less CFUs on catheter pieces and lower XTT metabolic activity than the blank group, with dosage dependence. SEM also showed that YHN could obviously decrease C. albicans adhesion on subcutaneous catheters in rats. According to qRT-PCR's results, YHN can down-regulate expressions of ALS1, ALS3, HWP1, EAP1 and MP65.</p><p><b>CONCLUSION</b>YHN could inhibit C. albicans biofilms in rats.</p>

FSI simulation of patient-specific aortic dissection and its bypass grafting / 医用生物力学

Objective To investigate the effects of different bypass grafting for treating DeBakey Ⅲ aortic dissection. Methods The patient-specific models of DeBakey Ⅲ aortic dissection based on CT images were reconstructed by using Mimics software, and two bridge models of bypassing between ascending aorta and abdominal aorta (AA), and between left subclavian artery and abdominal aorta (LA) were established by computer-aided method, respectively. Then numerical simulations were performed by using fluid-structure interaction (FSI) method to compare hemodynamic differences of these two models. Results After bypass surgery, the mass flow, mean and maximum velocities of the through lumen models were reduced to different degrees. Meanwhile, both the maximum blood pressures and displacements of the vessel walls of AA models were decreased, but those of LA models were increased. In contrast, all the above-mentioned hemodynamic parameters of the blind lumen models were decreased, especially for AA models. Conclusions The AA bypassing is a better treatment for DeBakey Ⅲ aortic dissection of through lumen and blind lumen. The therapeutic effects can be easily explained through simulation results, to ensure the scientific validity and clinical utility of bypassing.

Invasive detection of blood viscosity and its influencing factors in middle-aged and elderly people with cardiovascular diseases / 医用生物力学

Objective To detect the blood viscosity values and find out the statistically significant influencing factors of blood viscosity and their fitting formulas among the middle aged and elderly people with high incidence of cardiovascular diseases. Methods The subjects’ blood was collected in the hospital, together with their physiological and pathological information, and LG-R-80 series rotary viscometer detector was used to detect blood viscosity. The statistically significant factors of blood viscosity and their fitting formulas were obtained by using SPSS. Results Blood viscosity increased with age and body mass index (BMI) and reached its peak value in 60 year-old males (5.35 mPa•s) and 50 year-old females (4.45 mPa•s), respectively, then the variation of blood viscosity would be stabilized, with no more increase; the blood viscosity values of males in all groups with different ages were significantly higher than those of females, with difference value in the range of 0.28-0.90 mPa•s; the blood viscosity values were obviously higher in hypertension group than those in normal group, with statistically significant differences (P<0.1). Conclusions The blood viscosity distribution in people with high incidence of cardiovascular diseases has certain regular pattern, and the obtained fitting formula between blood viscosity and influencing factors in this study would provide useful references for further study such as variation of blood viscosity under different physiological conditions, effects of different viscosities on some cardiovascular diseases, and non-invasive detection of blood viscosities.

Hemodynamics-based numerical comparison between modified B-T shunt and central shunt / 医用生物力学

Objective Modified B-T shunt (MBTS) and central shunt (CS) are two common surgical procedures for the treatment of tetralogy of fallot (TOF). The purpose is to analyze and compare the hemodynamic features of MBTS and CS. Methods 3D anatomy was reconstructed by medical images obtained from a patient with TOF, and two computational models were generated through virtual operations. A lumped parameter model was constructed to predict the post-operational boundary conditions. Computational fluid dynamics (CFD) was performed for the two models. Results A persistent pulmonary blood perfusion was observed in each model both during the systolic phase and diastolic phase, but the maximum velocities in the shunt were different for the two models. The pressure drop of the shunt in CS model was higher than that in MBTS model. The wall shear stress of the shunt in the MBTS model ranged unevenly from 0.025 to 340 Pa, while the wall shear stress in CS model ranged relatively evenly from 32.2 to 72.6 Pa. Conclusions Pulmonary artery blood was increased effectively for both options. The blood perfusion of right upper extremity was decreased in the MBTS model. More blood was directed into the pulmonary artery in CS model. Attention should be paid to the fact that the pressure gradient was large at the proximal anastomosis in both models in clinic. This study provides important theoretical references for surgeons to make choice from the surgery options in the treatment with TOF.

Mechanical analysis on treatment of vertebral artery stenosis by stents with different links / 医用生物力学

Objective To investigate the mechanical effect of stents with different links on the treatment of vertebral artery stenosis, and provide scientific guidelines for the design of stent structure and clinical procedure of stenting intervention. Methods Models of three kinds of stents with different types of links (namely, L-stent, V-stent and S-stent according to the shape of links) and vertebral artery with stenosis were established by using Pro/Engineering, then the same boundary conditions were exerted on the three models to simulate the stent deployed in the vertebral artery by finite element analysis using ABAQUS. Results Compared with L-stent and V-stent, S-stent had a better compliance, generating smaller stress in the arterial wall, causing relatively weak vascular straightening. Due to smaller stress and axial shortening generated in the stent strut, S-stent made less lesion on the arterial wall. Conclusions The therapeutic effect of S-stent is the best among the three kinds of stents, which could reduce in-stent-restenosis, and has good prospect in clinical application.

Recent development and application of hemodynamics / 医用生物力学

The study of hemodynamics, which refers to dynamics inside the blood circulation, mainly includes the flow rate, flow resistance, pressure, shear stress, disturbed flow, as well as their associations in between. Therefore, with its important significance in the clinical treatments of vessel curvature, arterial stenosis or occlusion, pathological artery branches and aneurism, study about hemodynamics is essential to human health. Currently, extensive researches on hemodynamics have been conducted with respect to artery bypass, coronary arterial stenosis, abdominal aortic aneurysm, atherosclerosis, cerebral aneurysm and swirling flow. With the development of such research on hemodynamics, surgical planning and interventional therapy have improved rapidly. The influence mechanism of hemodynamic parameters, including pressure, flow resistance, flow rate, wall shear stress, blood viscosity, flow separation, turbulent flow, vortex on the post-operation complications could be deeply explored with the help of more and more clinical apparatus and have gained some achievements.

Hemodynamic simulation of vertebral artery stenosis treated by stents with different links / 医用生物力学

Objective To investigate the hemodynamic effect of stents with different types of links on treating vertebral artery stenosis, and provide scientific guidelines for the design of stent structure and the clinical procedure of stent intervention. Methods Models of vertebral artery with stenosis and three kinds of stents with different types of links (named as L-stent, V-stent and S-stentaccording to the shapes) were constructed by using Pro/Engineering. The expansions of these stents in the stenotic vertebral artery were simulated using ABAQUS, and three finite element models of the stented vertebral artery were then established for fluid flow analysis, and hemodynamic simulation was performed using ANSYS-CFX. Results Compared with V-link and S-link stent, L-link stent had smaller area of low wall shear stress distributions and smaller blood stagnation area. Conclusions With better hemodynamic effect, L-stent can potentially reduce the possibility of in-stent restenosis and provide scientific references for the choice of stent, the design of stent structure and surgical planning of stent intervention.

Fluid structure interaction analysis based on patient-specific internal carotid artery aneurysm model / 医用生物力学

Objective To analyze the distribution characteristics of blood flow and wall shear stress with the consideration of elasticity of the artery wall and to investigate the biomechanical factors inducing aneurismal rupture. Methods The three-dimensional patient-specific internal carotid artery aneurysm model was constructed based on two-dimensional medical scan images. The artery wall model was created based on the statistical data of human body. According to the condition of the pulsatile blood flow in human body, hemodynamics in internal carotid aneurysm with fluid structure interaction was simulated using finite volume method and finite element method. Results An obvious vortex flow in aneurismal cavity was found with the direction unchanged during a cardiac cycle. There was a region at the aneurismal neck and aneurismal dome where the value of wall shear stress was relatively high. It also found two regions in the aneurismal neck and the aneurismal dome where the value of Von Mises Stress reached the maximum locally. In view of the material strength, it should be easy to have aneurismal rupture in these areas. Conclusions The distribution characteristics of vascular wall stress can be obtained by the calculation of fluid structure interaction to further predict the possible position of aneurismal rupture.

Fluid-structure interaction numerical simulation of bypassed DeBakey Ⅲ aortic dissection / 医用生物力学

Objective To investigate the mechanical mechanism of bypass graft for the treatment of DeBakey III aortic dissection and explore the valid surgical planning. Methods Patient-specific models of DeBakey III aortic dissection, including the models of through lumen and blind lumen, before and after bypassing between ascending aorta and abdominal aorta, between left subclavian artery and abdominal aorta, were constructed, and then numerical simulations were performed using computational fluid dynamics (CFD) method under physiological flow conditions based on fluid-structure interaction (FSI). Results Blood flow velocity, pressure, vessel wall displacement of the false lumen after bypass graft were reduced by 38.86%, 15.347 kPa and 39.46% on average, respectively. Conclusions Bypass graft is an effective surgical method for the treatment of DeBakey III aortic dissection under specific conditions with good prospects in clinical application.