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Objective:To investigate gender differences in arterial velocity pulse index(AVI), which is an indicator of vascular stiffness, across various age groups.Additionally, the study will also examine the risk factors associated with AVI.Methods:This cross-sectional study enrolled 4311 patients with an average age of 57.8±12.8 years at Jiading Branch of Shanghai First People's Hospital between August 2020 and September 2021.Patients were divided into three groups based on age: young(<45 years old, n=755), middle-aged(45-59 years old, n=1260), and elderly(≥60 years old, n=2 296). The AVI of the subject was obtained using the cuff oscillation wave method.The subject's AVI was acquired using the cuff oscillation wave.High AVI, indicating arteriosclerosis, was defined as AVI≥33.The subjects were then divided into two groups: the high AVI group(122 cases)and the normal AVI group(4 189 cases).Results:The ankle-brachial index(AVI)was found to be 12.8±3.7, 17.5±5.7, and 19.8±6.5 in the young, middle-aged, and elderly groups, respectively.The study revealed that AVI increased with age( Ftrend=767.819, P<0.01). Additionally, the incidence of high AVI in middle-aged women was found to be(2.8% or 20/722), which was higher than that in men 0.9%(5/538)in the same age group.This difference was statistically significant( χ2=5.371, P<0.05). The results of the multivariate logistic regression analysis indicate that being overweight, having a higher height, and a pulse rate greater than 80 BPM are protective factors in preventing a high incidence of AVI.The odds ratios( OR)with 95% confidence intervals( CI)for these factors were 0.468(0.317-0.690), 0.926(0.895-0.958), and 0.143(1.026-2.432), respectively, all with a P-value less than 0.01.On the other hand, old age, systolic blood pressure of 140 mmHg or higher, and diastolic blood pressure of 90 mmHg or higher were identified as risk factors for AVI.The ORs with 95% CIs for these factors were 2.119(1.322-3.396), 6.652(4.136-10.699), and 1.580(1.026-2.432), respectively, all with a P- value less than 0.05l. Conclusions:Arterial stiffness, as measured by the ankle-brachial index(ABI), tends to increase with age.In middle-aged subjects, women have a higher incidence of high ABI than men.Independent risk factors for high ABI include age and increased blood pressure, while factors such as overweight and height may affect the measured value of ABI.
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Objective:To investigate the repair effect of amphiregulin (Areg) on injured lung tissue in mice with acute respiratory distress syndrome (ARDS) and its underlying mechanism.Methods:The ARDS mouse model was made by tracheal infusion of lipopolysaccharide (LPS), and bronchoalveolar lavage fluid (BALF) was extracted for 7 consecutive days. Adult male C57BL/6 mice were randomly (random number) divided into 5 groups ( n=4 per group): (1) Control group; (2) Areg group: mice were treated intraperitoneally (i.p.) with recombinant Areg; (3) LPS+PBS group; (4) LPS+Areg group; and (5) LPS+Anti-Areg group; mice were instilled with LPS, then were injected i.p. with PBS, Areg or Areg neutralization antibody (Anti-Areg) 30 min later. Lung tissue and BALF were extracted at day 1, 3, 5 and 7 after ARDS. HE staining was used to evaluate the pathological changes of lung tissues. The total protein content in BALF was detected by BCA method, and the concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and immunoglobulin M (IgM) were determined by ELISA method. The phosphorylated levels of epidermal growth factor receptor (EGFR) and expressions of proliferating cell nuclear antigen (PCNA) and surface proteins-C (SP-C) were tested by Western blot. The immunofluorescence was used to detect the co-expression of PCNA and SP-C in lung tissues. One-way analysis of variance was used to compare the mean values of normally distributed measurement data between groups. Comparisons between groups were performed using the least significant difference t-test. Results:Compared with that at before modeling [(51.05±2.47) pg/mL], Areg concentrations were increased significantly at day 1 [(71.97±6.51) pg/mL; P<0.01] and day 3 [(147.58±7.56) pg/mL, P<0.01] in the BALF after ARDS. At day 1 after ARDS, there were significant interstitial edema, neutrophil infiltration and alveolar collapse in the LPS+PBS group and LPS+Areg group. Compared with the LPS+PBS group at day 3, 5 and 7, the pathological changes of lung tissues were notably improved in the LPS+Areg group, while were more serious in the LPS+Anti-Areg group. Compared with the control group, the LPS+PBS group had higher levels of neutrophil number, total protein, IgM, TNF-α, IL-1β, and IL-6. However, Areg treatment significantly reduced the levels of these indicators. Moreover, the expressions of PCNA (1.34±0.10), SP-C (1.48±0.10) and p-EGFR (0.92±0.032) in the LPS+Areg group were significantly up-regulated compared with those in the LPS+PBS group (0.88±0.03, 1.06±0.15, and 0.68±0.03, all P<0.01). And compared with the LPS+PBS group, PCNA and SP-C double positive cells were significantly increased in the LPS+Areg group, but decreased in the LPS+Anti-Areg group. Conclusions:Areg enhances the proliferation of alveolar typeⅡ epithelial cells by activating EGFR pathway, therefore promotes the repair of lung tissues during ARDS development.
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Objective@#To detect the viscoelasticity of carotid artery in healthy volunteers using ultrasonic shear wave dispersion (SWD) technique, and explore the feasibility and influencing factors for SWD parameters.@*Methods@#Forty-five healthy volunteers were recruited and divided into elder group (≥50 years old) and younger group (<50 years old) according to the age. The carotid arteries were examined by SWD at systole, axial elastic modulus (SWER) and viscous index (SWDR) were obtained. The pulse wave velocity (PWV), a carotid artery circumferential elastic parameter was obtained and considered as the reference indicator. The difference of SWER, SWDR and PWV were compared between two groups; and the correlation between them were analyzed by Pearson analysis, respectively.@*Results@#①Compared with the younger group, the carotid PWV increased, while SWER and SWDR decreased in the elder group(all P<0.05). ②In all subjects, SWER was negatively correlated with PWV (r=-0.256, P<0.05). In the elder group, SWER was negatively correlated with systolic blood pressure (r=-0.357, P<0.05), and SWDR was negatively correlated with PWV (r=-0.393, P<0.05). In the younger group, SWDR was positively correlated with systolic blood pressure (r=0.366, P<0.05).@*Conclusions@#Compared with the elder group, the carotid viscoelasticity was higher in young people, and it is correlated with PWV. SWD can evaluate carotid viscoelasticity, and contribute to better understanding of its tissue characteristics.
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Objective To detect the viscoelasticity of carotid artery in healthy volunteers using ultrasonic shear wave dispersion ( SWD ) technique ,and explore the feasibility and influencing factors for SWD parameters . Methods Forty‐five healthy volunteers were recruited and divided into elder group ( ≥50 years old) and younger group ( ＜50 years old) according to the age . T he carotid arteries were examined by SWD at systole ,axial elastic modulus ( SWER ) and viscous index ( SWDR ) were obtained . T he pulse wave velocity ( PWV ) ,a carotid artery circumferential elastic parameter was obtained and considered as the reference indicator . T he difference of SWE R ,SWDR and PWV were compared between two groups ; and the correlation between them were analyzed by Pearson analysis ,respectively . Results ① Compared with the younger group ,the carotid PWV increased ,w hile SWE R and SWDR decreased in the elder group ( all P ＜0 .05) . ②In all subjects ,SWER was negatively correlated with PWV ( r ＝ －0 .256 , P ＜ 0 .05 ) . In the elder group ,SWER was negatively correlated with systolic blood pressure ( r ＝ －0 .357 , P ＜ 0 .05 ) ,and SWDR was negatively correlated with PWV ( r ＝ －0 .393 , P ＜0 .05 ) . In the younger group ,SWDR was positively correlated with systolic blood pressure ( r ＝0 .366 , P ＜0 .05) . Conclusions Compared with the elder group ,the carotid viscoelasticity was higher in young people ,and it is correlated with PWV . SWD can evaluate carotid viscoelasticity ,and contribute to better understanding of its tissue characteristics .
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Objective: To observe the feasibility of ultrasound shear wave dispersion imaging (USWD) in evaluating carotid viscoelasticity. Methods: Totally 45 volunteers were recruited and divided into 2 groups according to age, i.e. ≥50 years old group (n=23) and <50 years old group (n=22). Four shear wave viscoelastic modulus of the common carotid artery (CCA), including shear wave elastic modulus values of the superficial and deep walls (SWES and SWED), shear wave dispersion values of superficial and deep walls (SWDS and SWDD) were obtained using USWD, respectively. In addition, the pulse wave velocity (PWV) was measured. The viscoelastic indexes were compared between the two groups, and the correlations with age, blood pressure and PWV were analyzed. Results: Before and after adjusted with body mass index, systolic blood pressure (SBP) and diastolic blood pressure (DBP), SWES, SWED, SWDS and SWDD were higher in <50 years old group than those in ≥50 years old group (all P<0.05). Among all subjects, SWE was negatively correlated with age, SBP, DBP and PWV, respectively (r=-0.282, -0.374, -0.321, -0.256, all P<0.05). SWD was negatively correlated with PWV in ≥50 years old group (r=-0.393, P=0.038), while positively correlated with SBP in <50 years old group (r=0.366, P=0.048). Conclusion: The viscoelasticity of arterial wall can be non-invasively and quantitatively assessed with USWD.
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Objective To detecte the neovascularizations in carotid plaques using contrast-enhanced ultrasound (CEUS) and explore the relationship between the neovascularizations and the peripheral leukocytes in the patients with acute cerebral infarction. Methods Sixty-two patients with large artery atherosclerosis cerebral infarction were selected as cerebral infarction group;and 54 age-and gender-matched patients with atherosclerosis and without cerebral cerebrovascular events were recruited control group.The dominant carotid artery plaques were performed by CEUS,the peak of time-intensity curve(TIC-P) and the mean of time-intensity curve (TIC-M) were measured by off-line quantitative analysis.The peak (FC-P), time to peak (FC-TP),sharpness (FC-S) and under the curve area (FC-AUC) were obtained from fitting curves of time-intensity. The correlations between parameters of contrast-enhanced ultrasound and leukocyte counts were analyzed by Pearson correlation analysis. Results ①In the cerebral infarction group, the total leukocytes and neutrophils were higher than those in the control group,while the number of lymphocytes was lower than that of the control group(all P <0.05). ②In the cerebral infarction group,the TIC-P and TIC-M values were greater than those in the control group ( P < 0.05).Compared with the control group,the FC-P,FC-S and FC-AUC values in the cerebral infarction group were increased (all P <0.05). ③There was a negative correlation between PIG-P,TIC-M of FC-P and lymphocytes( r = -0.291,-0.263 and -0.270;all P <0.05).FC-S and FC-AUC were positively correlated with neutrophils ( r =0.261,0.298;all P < 0.05). Conclusions Carotid plaque neovascularizations is related to peripheral leukocyte count.CEUS help us know more the vulnerability of plaque.
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Objective To observe the correlation between CEUS quantitative parameters of carotid plaques and leukocytes in patients with acute ischemic stroke.Methods Sixty-two patients with large artery atherosclerosis stroke (LAAS group) confirmed by CT or MRI were enrolled,while 54 patients in the same period of hospitalization,age and gender-matched,no history of cardiovascular events with atherosclerosis were taken as control group.The correlation between CEUS quantitative parameters of carotid plaques and leukocytes in two groups were compared.Multiple linear regression model was built and the risk factors of CEUS quantitative parameters were analyzed.Results The total leukocytes count,neutrophils count and neutrophil/lymphocyte ratio in LAAS group were higher,while the lymphocytes count was lower than those in control group (all P＜0.05).CEUS parameters,including timeqntensity curve (TIC) peak (TIC-P),mean (TIC-M),fitting curve (FC) peak (FC-P),sharpness (FC-S) and area under the curve (FC-AUC) of carotid plaques were higher than those in control group (all P＜0.05),while neutrophils count and neutrophil/lymphocyte ratio were positively correlated with FC-AUC (r=0.298 and 0.739,respectively;all P＜0.05).Total leukocytes count was independent risk factor of TIC-P,and neutrophil/lymphocyte ratio was independent risk factor of FC-AUC (all P＜0.05).Conclusion CEUS quantitative parameters of carotid plaques related to leukocytes count.Increased leukocytes or neutrophil/ lymphocyte ratio might rise vulnerability of plaques.
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Objective To evaluate the effects and safety of dezocine and dexmedetomidine hydrochloride on the prevention of the pediatric postoperative agitation. Methods A total of 90 pediatric patients undergoing prepuce cerclage were randomly divided into 3 groups(n=30):dezocine group( Group Dez),dexmedetomidine group( Group Dex) and control group ( Group C),all groups were implemented general anesthesia combining with penile dorsal nerve block anesthesia.After induction of anesthesia,Group Dez and Group Dex were given 0.1 mg·kg-1of dezocine and 0.5 μg·kg-1of dexmedetomidine hydrochloride,respectively,Group C was given 0.9% sodium chloride solution.The rate of pediatric agitation,the operating room, the recovery time,the amount of additional propofol during the operation and the adverse reaction incidence within 6 hours after the surgery(circulation and respiratory depression,drowsiness,headache,nausea and vomiting) were observed and recorded. Results All groups have the surgery successfully done.There were no significantly difference among the three groups on the recovery time( P>0.05).The incidence of postoperative agitation was 3.33% in Group Dez,0.00% in Group Dex,46.67% in Group C,respectively( P<0.05 ).All of the pediatrics in three groups were not given additional propofol.There was no obvious adverse reaction at the time of 6 hours after surgery. Conclusion Dezocine and dexmedetomidine hydrochloride both can reduce the rate of postoperative agitation in pediatric patients and have no obvious side effects.Therefore,the clinical use of dezocine and dexmedetomidine hydrochloride are safe and effective.
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Objective To study the change rules with age in morphologic properties of common carotid artery,and to discuss its aging process after kidney transplantation.Methods Thirty-one patients with end stage renal disease (ESRD) supported by hemodialysis,31 kidney transplant recipients (KTR) and 84 control subjects were offered an ultrasound of carotid artery.The carotid intima media thickness (CIMT) and common carotid artery diameter (CCAD) of right carotid arteries were measured by ultrasonic frequency tracking.The tends for slope of CIMT and CCAD with age were analyzed by linear regression analysis.Results Compared with KTR group and control group,ESRD group had significantly thicker CIMT and wider CCAD,but there was no significant difference between KTR group and control group.The linear regression showed the development of CIMT were positively associated with age (P＜0.05).Compared with KTR group and ESRD group respectively,the slope of CIMT with age (unstandardized coefficients b) in control group was greater (Z=1.417,P =0.006;Z =2.223,P＜0.001).There was no significant difference between KTR group and ESRD group (Z =1.038,P =0.723).The development of CCAD were also positively associated with age (P＜0.05).Compared with control group,the slope of CCAD with age in ESRD group was less (Z =1.677,P =0.002).Conclusions After successful kidney transplantation,some morphologic properties of carotid artery are improved and resume the normal aging process.
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Objective To analyze the relation between carotid intima-media thickness (IMT) and the shear rate (SR),and to explore the effect of SR on IMT in the patients with end-stage renal disease (ESRD)and the kidney transplant recipients (KTR).Methods From March 2014 to December 2015,31 KTR and 31 patients with ESRD supported by hemodialysis and 84 control subjects underwent an carotid ultrasound in Shanghai General Hospital affiliated to Shanghai Jiaotong University.Bilateral carotid IMT and SR were measured.The differences of IMT and SR in three groups were compared by single factor analysis of variance.SNK-q test was used to compare the two groups.The correlation between SR and bilateral IMT was analyzed by linear regression analysis in healthy control group,ESRD group and KTR group.Results On the right,in ESRD,KTR and control group,the IMTs were (561.9± 147.7) μm,(480.5±90.3) μtm and (529.7±131.80) μtm respectively.Compared with KTR and control group,the IMT on right was thickest in ESRD,but there was no significant difference between KTR and control group in right IMT.On the left,the IMTs were (517.5± 164.7) μm,(506.7± 126.3) μm and (467.0± 106.4) μm in control group,ESRD and KTR,respectively.Among groups,there was no significant difference.On the right,the SRs were (134.01 ±56.4) s-1,(133.4±43.7) s-1 and (175.8±68.3) s-1 in ESRD,KTR and control group,respectively.In ESRD and KTR groups,the SR of the right carotid artery was less than that of the control group,and had significant difference (q=3.133,P=0.002;q=3.470,P ＜ 0.001).There was no significant difference in right SR between ESRD and KTR.On the left,the SRs were (146.3±55.9) s-1,(138.5±43.8) s-1 and (154.7±60.8) s-1 in ESRD,KTR and control group,respectively,and had no significant difference.There was linear negative correlation between SR and IMT in healthy control group,ESRD group and KTR group,respectively (right:r=-0.384,-0.082,-0.454;left:r=-0.572,0.223,-0.276,all P ＜ 0.05).Conclusions The IMT was thickened in ESRD group,but got thinning after successful kidney transplantation.The SR played a vital role in this alteration of IMT.
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Objective To discuss the value of the new parameter of myocardial elasticity derived from circumferential strain.Methods Right ventrieular apical pacing was established on the beagle dogs.Before and after pacing,the peak of early diastolic flow velocity (E peak),peak of atrial flow velocity (A peak),and the ratio of A/E were measured.The peak pressure-rise rate (+ dp/dtmax),peak pressure-fall rate (-dp/dt max),left ventricular systolic pressure(LVSP),LV diastolic pressure(LVDP)were measured by cardiac catheterization.The circumferential strain at the levels of base (CSRA),papillary (CSPM) and cardiac apex (CSAP) were measured,and the parameter of myocardial clasticity at the levels of base (EBA),papillary (EPM) and cardiac apex (EAP) were measured and calculated,respectively.Results ①After pacing,the + dp/dt and LVDP were increased,but the-dp/dtmax was decreased (P ＜0.05).② After pacing,the CSPM and CSAP were all decreased,but EBA,EPM,EA were all increased(P ＜0.05).③ The areas under the receiver operating characteristic curves (ROC) of CSAP,CSPM,EAP,EPM and EBA were all 1,and the area under the curve of CSBA was 0.687.EAB,EPM and EAP were significant negative correlation with CSPM and CSAP,but are positive correlated with A/E and LVDP (P ＜ 0.05).Conclusions The parameter of myocardial elasticity derived from circumferential strain includes useful information about myocardial deformation and function.The new parameter can be applied to assess the diastolic function of left ventricle.
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Objective To evaluate the value of ultrasound biomicroscopy (UBM) in assessment of atherosclerosis in apolipoprotein E (ApoE) knockout mice feeding with western diet.Methods Sixteen ApoE knockout mice in 8 weeks age were selected,then divided into two groups.One group was fed with west diet as high-fat group,and another group was fed with normal diet as control group.Intima-media thickness (IMT) and plaque area in the aortic root were assessed by UBM in two groups after 8 weeks and 16 weeks.And the measurements of UBM were compared with results of histopathology and blood-fat.ResultsThicken wall and plaque could be find in aortic root in control group and high-fat diet group byUBM.IMT and plaque area in high-fat diet group was significantly higher than those of control group ( P ＜ 0.05).The IMT and plaque area in UBM were good correlation with histopathology ( rwas 0.81 and 0.70 respectively).The triglyceride(TC) and total cholesterol in high-fat diet group was significantly higher than those of control group ( P ＜0.05),and IMT in UBM were increased with the elevated level of TC,there was a positive correlation between IMT and TC( r =0.528).ConclusionsWestern diet can accelerate the process in formation of atherosclerotic plaque in ApoE knockout mice.UBM can be used to observe this prograss noninvasively in vivo mice.
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Objective To evaluate the cardiovascular stiffness and its coupling of patients with hypertension by ultrasound.Methods Fifty patients with essential hypertension and 30 age- and gendermatched subjects without hypertension,diabetes and other cardiovascular diseases as control group were enrolled in this study.The parameters of structure and function of left ventricle,blood flow were measured by echocardiography.The blood pressure and carotid-femoral pulse wave velocity (CFPWV) were also measured.The derived corresponding parameter:end-systolic pressure(ESP),effective arterial elastance (Ea),end-diastolic (Ed),end-systolic ventricular elastance (Ees) and Ea/ Ees were calculated respectively.Results Ees was correlated positively with ejection fraction (r =0.378,P =0.005),while Ea was correlated positively with CFPWV( r =0.289,P ＜0.001).Ed was correlated negatively with e/a ( r =- 0.333,P =0.027).Posterior wall of left ventricle was correlated positively with Ed and Ea( r =0.388,P =0.016; r =0.336,P =0.026).Ea and Ed in patients with hypertension were significantly higher than those in control group( P ＜0.05),but there was no significant difference of Ees and Ea/ Ees between two groups( P ＞ 0.05).Conclusions Arterial stiffness is associated with ventricular stiffness,and their matching relation can be applied to evaluate ventricular-arterial coupling.
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Objective To investigate the feasibility of mean wave intensity (MWI), W1 and W2 in assessing the function of common carotid artery (CCA) before and after cold presser test with wave intensity analysis. Methods Twenty-four healthy subjects were enrolled. The W1, W2, and other parameters of blood flow in resting, before and after cold presser test of CCA, the inner diameter different rate and MWI of blood flow were calculated respectively. The receiver operation characteristic (ROC) curves were drawn, and of the effectiveness of MWI, W1 and W2 was compared. Results The different rate of diameters and W1 decreased significantly when subjects underwent cold presser test (P＜0.05), but MWI and W2 increased significantly (P＜0.05). The area under ROC curves was 0.858, 0.731 and 0.698, corresponding to MWI, W1 and W2 (P＞0.05). Conclusion The function of CCA can be evaluated with MWI calculated from conventional parameters.
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Objective To investigate the interferences of the variations in the blood pressure and vasoreactivity to the parameters of arterial elasticity via cold pressor test(CPT) in healthy young men. Methods The wave intensities(WI) of the right common carotid artery(RCCA) in twenty-two healthy young men during CPT were measured by echo-tracking technique. The parameters of arterial elasticity, including stiffness parameter (β),pressure-strain etastic modulus(Ep), arlerial compliance(AC),augument index(AI) , pulse wave veloctiy-β (PWVβ),and pulse wave velocity_WI(PWV_WI) from WI analysis during CPT were recorded and statistically compared with the baseline data. Results During CPT, the heart rates increased slightly ( P <0. 05) and the mean arterial pressures increased obviously ( P <0. 05); As to the parameters of arterial elasticity, the Ep,AI, PWVβ,and PWV_WI increased obviously ( P <0. 05), AC decreased ( P <0. 05), while the (3 didn't change. Conclusions The β is affected little by the blood pressure and vasoreactivity, and can reflect the actual arterial elasticity; while the Ep, AC, AI, PWVβ, and PWV_WI are affected much by blood pressure and vasoreactivity. When the latter parameters are used to evaluate the arterial elasticity, the interferences of variations in blood pressure and vasoreactivity must be excluded.
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Objective To evaluate the parameters of inner diameter different rate (D%), mean wave intensity(MWl) and diameter-adjusted mean wave intension(DAMWI) in assessing the function of common carotid artery(CCA) by quality intima-media thickness(QIMT) technique. Methods Twenty-four healthy subjects were performed 2D and CDFI examination under the normal quiescent and cold pressor test(CPT) condition respectively. The diastolic and systolic diameters of left-CCA were measured by QIMT respectively. Corresponding the inner diameter different range,rate,MWI and DAMWI were calculated respectively. The curves of their ROC were drawn. Results The different range and rate of diameters were decreased when subjects suffered CPT (P< 0.05) ,but the MWI and DAMWI were increased (P<0. 05). The areas under the ROC curves were 0. 827,0. 821 and 0.728 corresponding DAMWI, MWl and different rate of diameter. There was no significant difference among them(P>0. 05). Conclusions Conclusions The changed rate of diameter can be measured exactly by QIMT. The function of CCA can Be evaluated by MW1 and DAMWI which were calculated by conventional parameters.
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Objective To evaluate the effect of normal respiration on motion and disfiguration of interventricular septum (IVS) by observing the change of interventricular septum radius of curvature (IVSRC). Methods The 2D short-axis images at chordae tendineae of mitral valve were recorded during inspiration and expiration respectively by Acuson Sequoia 512 in 21 normal subjects. Speed of blood flow of each valve, electrocardiogram and respiratory tracing were recorded simultaneously. Two doctors who were double-blind measured the IVSRC using self-designed software. Results During normal inspiration, the peak E velocity of mitral valve and the flow velocity of aortic valve decreased,while the peak E velocity of tricuspid valve and the flow velocity of pulmonary valve increased. The IVSRC curvatures were (25.914± 6.082)mm during inspiration, and (22.296±4.398)mm during expiration, there was difference in two respiration phases(P <0.0001). Conclusions IVSRC can be used to evaluate motion and disfiguration of IVS. It has a good repeatability and is an effective way to observe the change of pleural pressure which is produced by respiration.
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Objective Radius of curvature (RC) and velocity vector imaging (VVI) were joined to evaluate the deformation and motion of interventricular septum(IVS). Methods VVI was performed in fifteen healthy volunteers and obtained dynamic images at chordae tendineae of mitral valve in short axis view. The images were stored and analyzed to obtain circumferential peak stain of IVS. In the same short axis view, the static images were captured at end-systole and end-diastole respectively before they were analyzed by self-made software. The length of arc and RC were measured automatically by the software, so the shortening rates of them could were calculated. Results The length of arc and RC were longer at end-diastole than those at end-systole(P<0.0001). The shortening rate of length of arc was compared with circumferential peak stain of IVS (P=0.123) and they were correlation (r = 0. 840, P = 0. 0001 ). Blant-Altman analysis indicated that the concordance was well. Conclusions The length of arc and RC can evaluate the deformation and motion of IVS.
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Objective To observe the effects and the mechanism of the thoracic pressure variation on the velocity of tricuspid regurgitation in quiet respiration, to accurately estimate the pulmonary artery systolic pressure,and to verify the new proposed mechanism of respiration effects on hemodynamics using echocardiography. Methods Continuous-wave Doppler spectra of tricuspid regurgitation were recorded with Sequoia 512 in 50 patients who had stable tricuspid regurgitation. Electrocardiogram and respiratory tracing were recorded simultaneously. The velocities and the pressure gradients were recorded during different respiration phases for analyzing. Results Respiration reliably affected on tricuspid regurgitant velocity. There were three patterns of manifestation:①The velocity increased in the inspiratory phase. ②The velocity decreased in the inspiratory phase. ③The velocity changed randomly. Conclusions Thoracic pressure variations had definite effects on the velocity of tricuspid regurgitation and tricuspid gradient. This research indicated that to obtain accurate and reliable Doppler echocardiographic measurement of the pulmonary artery systolic pressure, the measurement should be at the time between inspiration and expiration.
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Objective To investigate the effects of sevoflurane on ca2+ transsarcolemmal influx and ca2+ release function of endoplasmic reticulum in isolated outer hair cells (OHCs) of guinea pigs and the possible mechanism by which sevofhlrane acts on cochleas.Methods The experiment was performed in 2 parts.In experiment I:twelve adult guinea pigs(8 male,4 female)weighing 180-230 g were used.OHCs were mechanically sparated after enzymatic incubation.Thirty OHCs with favorable activity were divided into 3 groups (n=10 each):group I control(C);group Ⅱ low concentration sevoflurane (1.7%,group S1) and group Ⅲ high concentration sevoflurane(3.4%,group S2).The OHCs were stained with 6 umol/L Fluo-3AM in estefified form for 40 min.Group S1 and S2 were pretreated with 1.7% and 3.4% sevoflugsne respectively for 20 min.KCI 40 mmol/L was then added.The intracellular ionized Ca2+ concentration ([C2+]I) was determined byintracelhlar Ca2+ fluorescent intensity using laser scanning confocal microscope.The protocol of the experimentⅡ was the same as the experimentI.The only difference was that caffeine 20 mmol/L was added instead of KCI 40 mmol/L.Results In experiment I:there was no significant difference in baseline[ca2+]I and[ca2+]I after being exposed to sevoflurane among the 3 groups.[Ca2+]I was significanfly increased after addition of KCI as compared with the baseline[Ca2+]I and was significantly lower in group Sl and S2 than in group C and was the lowest in group S2.In experimentⅡ:the[ca2+]I was significantly increased after addition of caffeine but there was no significant difference in[Ca2+]I among the 3 groups.Conclusion Sevoflurane can inhibit voltage-dependent Ca2+ channel opening in a concentration-dependent manner but can not affect ryanodine-sensitive Ca2+ release function of endoplasmic reticuhm in isolated outer hair cells of guinea pigs.