AIMTo investigate the effect of flavone on ocular blood flow in rabbit eyes and the formation of choroidal neovascularization (CNV) in rat model of age-related macular degeneration (AMD).
Background:Decrease of ocular blood flow has been linked to the pathogenesis of ocular diseases such as glaucoma and age-related macular degeneration.Current methods that measure the pulsatile blood flow have major li...Background:Decrease of ocular blood flow has been linked to the pathogenesis of ocular diseases such as glaucoma and age-related macular degeneration.Current methods that measure the pulsatile blood flow have major limitations,including the assumption that ocular rigidity is the same in all eyes.Our group has recently developed a new method to measure the pulsatile choroidal volume change by direct visualization of the choroid with OCT imaging and automated segmentation.Our goal in this study is to describe the distribution of PCBF in a healthy Caucasian population.Methods:Fifty-one subjects were recruited from the Maisonneuve-Rosemont Hospital Ophthalmology Clinic and underwent PCBF measurement in one eye.The distribution of PCBF in healthy eyes was assessed.Results:The distribution of PCBF among the healthy eyes was found to be 3.94±1.70µL with this technique.Conclusions:This study demonstrates the normal range of PCBF values obtained in a healthy Caucasian population.This technique could be used for further investigation of choroid pulsatility and to study glaucoma pathophysiology.展开更多
Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical p...Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical practice due to their limitations and lack of standardization.Moreover,no reliable technique is currently available to measure the pulsatile choroidal blood flow(PCBF).We propose a novel method based on video-rate optical coherence tomography(OCT)imaging and automated segmentation to measure the pulsatile component of choroidal blood flow in vivo,and demonstrate its repeatability.Methods:Adapted from our earlier work(Beaton et al.),this method uses video-rate OCT with enhanced depth imaging and automated segmentation of the choroid to measure the pulsatile choroidal volume change.Imaging is carried out at the fundus for less than a minute at 7 Hz.In each frame,choroidal thickness(CT)is measured by a segmentation algorithm based on graph cuts using an edge-probability weighting scheme.The algorithm computes the CT change corresponding to choroidal filling over the time-series and subsequently derives the pulsatile choroidal volume change through an approximate model of the eye.Fifty-eight subjects were recruited from the Maisonneuve-Rosemont Hospital and PCBF was measured twice in one eye within the same session and by a single examiner.Repeatability was assessed using the Bland-Altman plot and Intraclass correlation coefficient as calculated with SPSS.Results:Two measurements of PCBF were successfully obtained for each eye using our technique.The average measures ICC for choroidal volume change was 0.929(95%CI,0.881,0.958),showing good to excellent repeatability.The Bland-Altman plot and Pearson coefficient(r=0.840,P<0.001)showed agreement and a strong correlation respectively between intra-session measurement of OR in all examined eyes.Conclusions:This study confirms the high repeatability of pulsatile choroidal blood flow measurements obtained with our optical method,allowing further investigation of blood flow in ocular diseases such as glaucoma and AMD.展开更多
This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The ...This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The effects of inertial and inclination angles that have not been discussed previously have been included. It has been shown that different flows for a uniform tube (vein) are possible. However, this flow matches that of a jugular vein which is supercritical, and the steady solution has been given by the balance between the driving forces of gravity and the viscous resistance to the flow at the right atrium of the heart must be sub-critical for a fixed right-atrium pressure which means that an elastic jump is required to return the flow to sub-critical from the supercritical flow upstream this type of relationship gives rise to flow limitation at the same time given any right atrium fixed pressure there exists a maximum flow rate which when exceeded the boundary conditions of the flow do not hold boundary conditions at the right atrium are not satisfied hence making the steady flow impossible this mechanism of flow limitation is slightly different from the other one in that causes airways through forced expiration from the observation made it is clearly shown that there is an intravascular pressure difference with a change in height.展开更多
AIM:To evaluate the changes in ocular blood flow with color Doppler ultrasonography(CDU) after intravitreal triamcinolone acetonide(IVTA) injection.METHODS:A total of 46 patients who underwent IVTA(4 mg/0.1 mL) inject...AIM:To evaluate the changes in ocular blood flow with color Doppler ultrasonography(CDU) after intravitreal triamcinolone acetonide(IVTA) injection.METHODS:A total of 46 patients who underwent IVTA(4 mg/0.1 mL) injection for diabetic macular edema(DME)(n =22), central retinal vein occlusion(CRVO)(n =12) and choroidal neovascular membrane(CNVM)(n =12) were included in the study. Peak systolic velocity(PSV), end diastolic velocity(EDV) and resistivity index(RI) were measured from the ophthalmic artery(OA), the central retinal artery(CRA) and the posterior ciliary artery(PCA)of each patient with CDU before, at the end of the first week and at the end of the first month following IVTA injection.RESULTS:In the DME group, PSV of OA at the first of the first month(mean ±SD)(37.48 ±10.87 cm/s) increased compared to pre-injection value(31.39 ±10.84 cm/s)(P =0.048). There was a statistically significant decrease(P =0.049) in PSV of CRA at the end of the first month(7.97±2.67 cm/s) compared to the pre-injection(9.47±3.37 cm/s).There was not any statistically significant difference onthe other parameters in the DME group. Also, there was not any statistically significant difference on the ocular blood flow values in the CRVO and CNVM groups.CONCLUSION:We observed that 4 mg/0.1 mL IVTA increased PSV of OA and decreased PSV of CRA in DME patients and did not have any effect on ocular blood flow values of CRVO and CNVM patients.展开更多
Purpose:Age-related macular degeneration(AMD)as a disease entity is "dry" at early stage and made up of two main components at late stage:atrophic AMD and exudative AMD.Quercetin acts as an anti-oxidant to p...Purpose:Age-related macular degeneration(AMD)as a disease entity is "dry" at early stage and made up of two main components at late stage:atrophic AMD and exudative AMD.Quercetin acts as an anti-oxidant to protect retinal pigment epithelial cells(RPE)from damaged by oxidative stress,but its effect on formation of choroidal neovascularization(CNV)in AMD is unclear.The aim of this study is to investigate the effect of quercetin on the formation of CNV in AMD.Methods:The development of CNV induced by laser was detected.by fluorescein angiography(FA).Colored microsphere technique was used to determine the choroidal blood flow in ocular hypertensive rabbit eyes.In in vitro studies,HUVECs were treated with NaIO3,H2O2 and NaN3 to induce oxidative cell damages.The effect of quercetin on various oxidations-induced injuries in HUVECs was measured by MTT assay.HUVECs migration was assessed using a wound healing assay.Results:Quercetin significantly inhibited the formation of laser-induced CNV.The choroidal blood flow in rabbit eyes was significantly increased after quercetin instillation.In vitro results showed quercetin enhanced various oxidations-induced injuries in HUVECs and inhibited migration of HUVECs during wound healing.Conclusion:Quercetin inhibited the formation of CNV both in vivo and in vitro and increased choroidal blood flow.It could become a promising candidate for the treatment of AMD.展开更多
目的观察不同针灸介入时机对大脑中动脉供血区急性脑梗死神经功能预后的影响。方法回顾性选取2020年1月—2022年8月收治的116例大脑中动脉供血区急性脑梗死患者的临床资料进行分析,根据针灸介入时机分为两组。两组均进行静脉溶栓及常规...目的观察不同针灸介入时机对大脑中动脉供血区急性脑梗死神经功能预后的影响。方法回顾性选取2020年1月—2022年8月收治的116例大脑中动脉供血区急性脑梗死患者的临床资料进行分析,根据针灸介入时机分为两组。两组均进行静脉溶栓及常规药物治疗,观察组61例患者于发病72 h内给予针灸治疗,对照组55例患者于发病2周时给予针灸治疗。检测两组不同时间点侧支循环代偿情况、脑损伤标志物的水平,评估两组不同时间点简易精神状态检查(Mini-mental state examination,MMSE)评分、神经功能评分、Barthel指数(Barthel index,BI)评分、肢体运动功能评分、中医症状评分的差异,统计两组疗效。结果治疗前,两组侧支循环代偿情况比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组患侧大脑前动脉平均血流速度与对侧大脑中动脉平均血流速度的比值(Ratio of the average flow ve⁃locity of the affected anterior cerebral artery to the average flow velocity of the contralateral middle cerebral artery,iVACA/cVM⁃CA)较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组患侧大脑后动脉平均血流速度与对侧大脑中动脉平均血流速度的比值(Ratio of the average flow velocity of the affected posterior cerebral artery to the average flow velocity of the contralateral middle cerebral artery,iVPCA/cVMCA)与治疗前比较,差异无统计学意义(P>0.05)。治疗前,两组脑损伤标志物比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组钙结合蛋白β(Calcium binding proteinβ,S100β)、神经胶质纤维酸性蛋白(Glial fibrillary acid protein,GFAP)较治疗前下降,观察组同时间点较对照组更低(P<0.05)。治疗前,两组Fugl-Meyer评分、中医症状评分等相关评分比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组MMSE评分、BI评分及上肢和下肢Fugl-Meyer评分较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组美国国立卫生院神经功能缺损(National institutes of health stroke scale,NIHSS)评分、中医症状评分较治疗前下降,观察组同时间点较对照组更低(P<0.05)。观察组总有效率为88.52%(54/61)高于对照组的72.73%(40/55),差异有统计学意义(P<0.05)。结论发病72h内采用针灸治疗可改善大脑中动脉供血区急性脑梗死脑损伤标志物的表达,改善脑血流,促进神经功能的恢复,有利于疾病的康复。展开更多
文摘AIMTo investigate the effect of flavone on ocular blood flow in rabbit eyes and the formation of choroidal neovascularization (CNV) in rat model of age-related macular degeneration (AMD).
文摘Background:Decrease of ocular blood flow has been linked to the pathogenesis of ocular diseases such as glaucoma and age-related macular degeneration.Current methods that measure the pulsatile blood flow have major limitations,including the assumption that ocular rigidity is the same in all eyes.Our group has recently developed a new method to measure the pulsatile choroidal volume change by direct visualization of the choroid with OCT imaging and automated segmentation.Our goal in this study is to describe the distribution of PCBF in a healthy Caucasian population.Methods:Fifty-one subjects were recruited from the Maisonneuve-Rosemont Hospital Ophthalmology Clinic and underwent PCBF measurement in one eye.The distribution of PCBF in healthy eyes was assessed.Results:The distribution of PCBF among the healthy eyes was found to be 3.94±1.70µL with this technique.Conclusions:This study demonstrates the normal range of PCBF values obtained in a healthy Caucasian population.This technique could be used for further investigation of choroid pulsatility and to study glaucoma pathophysiology.
文摘Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical practice due to their limitations and lack of standardization.Moreover,no reliable technique is currently available to measure the pulsatile choroidal blood flow(PCBF).We propose a novel method based on video-rate optical coherence tomography(OCT)imaging and automated segmentation to measure the pulsatile component of choroidal blood flow in vivo,and demonstrate its repeatability.Methods:Adapted from our earlier work(Beaton et al.),this method uses video-rate OCT with enhanced depth imaging and automated segmentation of the choroid to measure the pulsatile choroidal volume change.Imaging is carried out at the fundus for less than a minute at 7 Hz.In each frame,choroidal thickness(CT)is measured by a segmentation algorithm based on graph cuts using an edge-probability weighting scheme.The algorithm computes the CT change corresponding to choroidal filling over the time-series and subsequently derives the pulsatile choroidal volume change through an approximate model of the eye.Fifty-eight subjects were recruited from the Maisonneuve-Rosemont Hospital and PCBF was measured twice in one eye within the same session and by a single examiner.Repeatability was assessed using the Bland-Altman plot and Intraclass correlation coefficient as calculated with SPSS.Results:Two measurements of PCBF were successfully obtained for each eye using our technique.The average measures ICC for choroidal volume change was 0.929(95%CI,0.881,0.958),showing good to excellent repeatability.The Bland-Altman plot and Pearson coefficient(r=0.840,P<0.001)showed agreement and a strong correlation respectively between intra-session measurement of OR in all examined eyes.Conclusions:This study confirms the high repeatability of pulsatile choroidal blood flow measurements obtained with our optical method,allowing further investigation of blood flow in ocular diseases such as glaucoma and AMD.
文摘This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The effects of inertial and inclination angles that have not been discussed previously have been included. It has been shown that different flows for a uniform tube (vein) are possible. However, this flow matches that of a jugular vein which is supercritical, and the steady solution has been given by the balance between the driving forces of gravity and the viscous resistance to the flow at the right atrium of the heart must be sub-critical for a fixed right-atrium pressure which means that an elastic jump is required to return the flow to sub-critical from the supercritical flow upstream this type of relationship gives rise to flow limitation at the same time given any right atrium fixed pressure there exists a maximum flow rate which when exceeded the boundary conditions of the flow do not hold boundary conditions at the right atrium are not satisfied hence making the steady flow impossible this mechanism of flow limitation is slightly different from the other one in that causes airways through forced expiration from the observation made it is clearly shown that there is an intravascular pressure difference with a change in height.
文摘AIM:To evaluate the changes in ocular blood flow with color Doppler ultrasonography(CDU) after intravitreal triamcinolone acetonide(IVTA) injection.METHODS:A total of 46 patients who underwent IVTA(4 mg/0.1 mL) injection for diabetic macular edema(DME)(n =22), central retinal vein occlusion(CRVO)(n =12) and choroidal neovascular membrane(CNVM)(n =12) were included in the study. Peak systolic velocity(PSV), end diastolic velocity(EDV) and resistivity index(RI) were measured from the ophthalmic artery(OA), the central retinal artery(CRA) and the posterior ciliary artery(PCA)of each patient with CDU before, at the end of the first week and at the end of the first month following IVTA injection.RESULTS:In the DME group, PSV of OA at the first of the first month(mean ±SD)(37.48 ±10.87 cm/s) increased compared to pre-injection value(31.39 ±10.84 cm/s)(P =0.048). There was a statistically significant decrease(P =0.049) in PSV of CRA at the end of the first month(7.97±2.67 cm/s) compared to the pre-injection(9.47±3.37 cm/s).There was not any statistically significant difference onthe other parameters in the DME group. Also, there was not any statistically significant difference on the ocular blood flow values in the CRVO and CNVM groups.CONCLUSION:We observed that 4 mg/0.1 mL IVTA increased PSV of OA and decreased PSV of CRA in DME patients and did not have any effect on ocular blood flow values of CRVO and CNVM patients.
文摘Purpose:Age-related macular degeneration(AMD)as a disease entity is "dry" at early stage and made up of two main components at late stage:atrophic AMD and exudative AMD.Quercetin acts as an anti-oxidant to protect retinal pigment epithelial cells(RPE)from damaged by oxidative stress,but its effect on formation of choroidal neovascularization(CNV)in AMD is unclear.The aim of this study is to investigate the effect of quercetin on the formation of CNV in AMD.Methods:The development of CNV induced by laser was detected.by fluorescein angiography(FA).Colored microsphere technique was used to determine the choroidal blood flow in ocular hypertensive rabbit eyes.In in vitro studies,HUVECs were treated with NaIO3,H2O2 and NaN3 to induce oxidative cell damages.The effect of quercetin on various oxidations-induced injuries in HUVECs was measured by MTT assay.HUVECs migration was assessed using a wound healing assay.Results:Quercetin significantly inhibited the formation of laser-induced CNV.The choroidal blood flow in rabbit eyes was significantly increased after quercetin instillation.In vitro results showed quercetin enhanced various oxidations-induced injuries in HUVECs and inhibited migration of HUVECs during wound healing.Conclusion:Quercetin inhibited the formation of CNV both in vivo and in vitro and increased choroidal blood flow.It could become a promising candidate for the treatment of AMD.
文摘目的观察不同针灸介入时机对大脑中动脉供血区急性脑梗死神经功能预后的影响。方法回顾性选取2020年1月—2022年8月收治的116例大脑中动脉供血区急性脑梗死患者的临床资料进行分析,根据针灸介入时机分为两组。两组均进行静脉溶栓及常规药物治疗,观察组61例患者于发病72 h内给予针灸治疗,对照组55例患者于发病2周时给予针灸治疗。检测两组不同时间点侧支循环代偿情况、脑损伤标志物的水平,评估两组不同时间点简易精神状态检查(Mini-mental state examination,MMSE)评分、神经功能评分、Barthel指数(Barthel index,BI)评分、肢体运动功能评分、中医症状评分的差异,统计两组疗效。结果治疗前,两组侧支循环代偿情况比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组患侧大脑前动脉平均血流速度与对侧大脑中动脉平均血流速度的比值(Ratio of the average flow ve⁃locity of the affected anterior cerebral artery to the average flow velocity of the contralateral middle cerebral artery,iVACA/cVM⁃CA)较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组患侧大脑后动脉平均血流速度与对侧大脑中动脉平均血流速度的比值(Ratio of the average flow velocity of the affected posterior cerebral artery to the average flow velocity of the contralateral middle cerebral artery,iVPCA/cVMCA)与治疗前比较,差异无统计学意义(P>0.05)。治疗前,两组脑损伤标志物比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组钙结合蛋白β(Calcium binding proteinβ,S100β)、神经胶质纤维酸性蛋白(Glial fibrillary acid protein,GFAP)较治疗前下降,观察组同时间点较对照组更低(P<0.05)。治疗前,两组Fugl-Meyer评分、中医症状评分等相关评分比较,差异无统计学意义(P>0.05)。治疗4周和随访时,两组MMSE评分、BI评分及上肢和下肢Fugl-Meyer评分较治疗前升高,观察组同时间点较对照组更高(P<0.05);两组美国国立卫生院神经功能缺损(National institutes of health stroke scale,NIHSS)评分、中医症状评分较治疗前下降,观察组同时间点较对照组更低(P<0.05)。观察组总有效率为88.52%(54/61)高于对照组的72.73%(40/55),差异有统计学意义(P<0.05)。结论发病72h内采用针灸治疗可改善大脑中动脉供血区急性脑梗死脑损伤标志物的表达,改善脑血流,促进神经功能的恢复,有利于疾病的康复。
