Our aim is to report 4 cases of central retinal vein occlusion following COVID-19 vaccine administration. In this case series, 4 patients between 23-32 years of age presented to us with unilateral central retinal vein...Our aim is to report 4 cases of central retinal vein occlusion following COVID-19 vaccine administration. In this case series, 4 patients between 23-32 years of age presented to us with unilateral central retinal vein occlusion after 2-15 days of getting vaccinated against COVID-19. One patient was a known case of hypertension and 1 was hypothyroid. All the patients had disc swelling, flame shaped haemorrhages, dilated and tortuous blood vessels in the retina. One patient had cystoid macular edema and was treated with intravitreal ranibizumab. As there were no positive systemic risk factors or incidents, COVID-19 vaccines might have an association with the central retinal vein occlusion in these cases. .展开更多
Introduction:COVID-19 patients are susceptible to hypercoagulability,thromboembolic,and vasculitis state;central retinal artery occlusion(CRAO)could be caused by hyperviscosity syndrome,thromboembolic accidents,and va...Introduction:COVID-19 patients are susceptible to hypercoagulability,thromboembolic,and vasculitis state;central retinal artery occlusion(CRAO)could be caused by hyperviscosity syndrome,thromboembolic accidents,and vasculitis.Evolving case reports are correlating CRAO with COVID-19 patients.Our case series aims to reveal the prevalence of SARS-CoV-2 among CRAO patients under the COVID-19 pandemic.Methods:Medical records of all CRAO patients who attended our tertiary referral hospital,during COVID-19 local outbreak(March to November 2020),were reviewed.Respiratory tract samples were tested for SARS-CoV-2 by the validated Xpert Xpress SARS-CoV-2 assay.If patients were able to cooperate,oropharyngeal saliva samples were obtained.Otherwise,nasopharyngeal and deep throat swabs were taken by registered nurses.Results:A total of 15 CRAO patients(7 males,8 females)were identified during the 9-month study period.The mean age was 72.1-years(range 45-88 year).None of the patients were infected by SARS-CoV-2 before their CRAO disease episodes.Three patients had a history of CRAO over the contralateral eye.No patient was diagnosed with COVID-19 up to their last follow-up(mean 255.4 days,range 152-341 days).Without any COVID-19 positive case,correlation statistical tests on SARS-CoV-2 infection and CRAO were not established.Conclusions:Some of the presumed COVID-19 related CRAO cases may be just coincident with at-risk patients,as COVID-19 is prevalent across the world.More in-depth research,with adjustment to known confounding risk factors,is needed to establish a genuine correlation.展开更多
Occlusion of vas deferens in uitro and in vivo with Nd2+ YAG laser of 100mW-1000mW was investigated. An optical fiber core in diameter of 200pm was inserted into the lumen of the uas uia a canula in & rabbits and ...Occlusion of vas deferens in uitro and in vivo with Nd2+ YAG laser of 100mW-1000mW was investigated. An optical fiber core in diameter of 200pm was inserted into the lumen of the uas uia a canula in & rabbits and 16 uasa deferens were irradiated in uiuo.The threshold lesion(denned as a half thickness of the uas wall being penetrated)at dijferent power and exposure duration was investigated in uitro. Temperature on the aduentitia was also determined.The uasa delerens were totally occluded in those irradiated with power of 800mW for 24 sec or with power of 1000mW for 16 sec 3 and 4 weeks after irradiation.The authors considered that it would be possible to insert percutaneously a fiber and coagulate vas deferens with laser for sterilization in the near future. However,more investigations are needed before it could be employed in the clinic.展开更多
AIM： To establish models of portal vein occlusion of hepatic VX2 tumor in rabbits and to evaluate the value of multi-slice CT. METHODS： Forty New Zealand rabbits were divided into 4 groups according to digital table...AIM： To establish models of portal vein occlusion of hepatic VX2 tumor in rabbits and to evaluate the value of multi-slice CT. METHODS： Forty New Zealand rabbits were divided into 4 groups according to digital table： Immediate group （group A; transplantation of tumor immediately after the portal vein occlusion）, 3-wk group （group B; transplantation of tumor at 3 wk after the portal vein occlusion）, negative control group （group C） and positive control group （group D）, 10 rabbits in each group. Hepatic VX2 tumor was transplanted with abdominalembedding innoculation immediately after the portal vein occlusion and at 3 wk after the portal vein occlusion. Meanwhile, they were divided into negative control group （Left external branch of portal vein was occluded by sham-operation, and left exite was embedded and inoculated pseudoly） and positive control group （Transplanted tumor did not suffer from the portal vein occlusion）. All rabbits were scanned with multi-slice CT. RESULTS： All 40 animals were employed in the final analysis without death. Tumor did not grow in both immediate group and 3-wk group. In 3-wk group, left endite was atrophied and growth of tumor was inhibited. The maximal diameter of tumor was significantly smaller than that in positive control group （2.55±0.46 vs 3.59±0.37 cm, t = 5.57, P 〈 0.001）. Incidences of metastasis in the liver and lung were lower in 3-wk group than those in positive control group （10% vs 400, and 90% vs 100%, respectively）. The expression intensities of the vascular endothelium growth factor （VEGF） in groups A, B, C and D were 0.10±0.06, 0.66±0.21, 0.28±0.09 and 1.48±0.32, respectively. VEGF expression level in the test group A was significantly lower than that in the negative control group C （t = 5.07; P 〈 0.001）.In addition, VEGF expression in the test group B was significantly lower than that in the positive control group D （t = 6.38; P 〈 0.001）. Scanning with multi-slice CT showed that displaying rate of hepatic artery branches was obviously lower in grade Ⅲ（40%） than that in grade Ⅰ（70%） and Ⅱ（100%） （P 〈 0.05）; but there was no significant difference in displaying rate of the portal vein at various grades. Values of blood flow （BF） of the liver, blood volume （BV）, mean transit time （MTT） and permeability of vascular surface （PS） were lower in the immediate group and 3-wk group than those in control groups, but values of hepatic arterial fraction （HAF） were increased. Significant positive correlations were existed between BF and BV （r = 0.905, P 〈 0.01）, and between BF and PS （r = 0.967, P 〈 0.01）, between BV and PS （r = 0.889, P 〈 0.01）. A significant negative correlation existed between PV and HAF （r = -0.768, P 〈 0.01）, between PS and HAF （r = -0.557, P 〈 0.01）. The values of BF, BV and PS had a positive correlation with VEGF （rBF = 0.842, rBV = 0.579, rPS = 0.811, P 〈 0.01） . However, there was no significant correlation between the values of MTT and HAF and the VEGF expression （rMTt = 0.066, rHAF = -0.027）. CONCLUSION： Ligating the left external branch of portal vein is an ideal way to establish models of portal vein occlusion in rabbits with hepatic VX2 tumor. Multi slice CT plays a key role in evaluating effect of portal vein occlusion.展开更多
β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to...β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to be highly related to ischemic stroke,the specific role and underlying mechanistic action ofβ2M are poorly understood.In this study,we established a rat model of focal cerebral ischemia by occlusion of the middle cerebral artery.We found thatβ2M levels in the cerebral spinal fluid,serum,and brain tissue were significantly increased in the acute period but gradually decreased during the recovery period.RNA interference was used to inhibitβ2M expression in the acute period of cerebral stroke.Tissue staining with 2,3,5-triphenyltetrazolium chloride and evaluation of cognitive function using the Morris water maze test demonstrated that decreasedβ2M expression in the ischemic penumbra reduced infarct volume and alleviated cognitive deficits,respectively.Notably,glial cell,caspase-1(p20),and Nod-like receptor pyrin domain containing 3(NLRP3)inflammasome activation as well as production of the inflammatory cytokines interleukin-1β,interleukin-6,and tumor necrosis factor-αwere also effectively inhibited byβ2M silencing.These findings suggest thatβ2M participates in brain injury and cognitive impairment in a rat model of ischemic stroke through activation of neuroinflammation associated with the NLRP3 inflammasome.展开更多
Objective To predict the tolerance of the brain to carotid occlusion using noninvasive methods.Methods The peak(pV) and mean blood flow velocity(mV) of middle cerebral artery (MCA) and anterior cerebralartery (ACA) an...Objective To predict the tolerance of the brain to carotid occlusion using noninvasive methods.Methods The peak(pV) and mean blood flow velocity(mV) of middle cerebral artery (MCA) and anterior cerebralartery (ACA) and pulsatility index (PI) were measured pre-and postoperatively with transcranial Dopplerultrasound diagnosis system(TCD) associated with the regional cerebral oxygen (rSO2) and somatosensory evokedpotentials (SSEPs) evaluation in 15 patients during manual compression, temporary occlusion and permanentocclusion Ol the carotid artery (CAO). Results There was no neurological delcit appearing during CAO in allthe cases. The mV of ipsilateral MCA and ACA reduced (31.79±13.59)% (12.58% ~56.16%) and reversed to 27.69±23.15cm/s and the rSO2 decreased (5.29±1.96)% (2%~9%). There was a linear correlation between percentchange in mV of ipsilateral MCA and rSO2 fall (P=0.0001). No more than 50% attenuation of SSEPs occurred inall the cases. The difference of PI in all recording time was not signilicant in our study. The pV was correlatedwith mV (P=0.0001). No variables were different significantly between compression and occlusion. Conclusion Afall in velocity by more than 70%, in rSO2 by more than 10% or in SSEPs amplitude by more than 50% iscompelling evidence for intolerance to CAO.展开更多
Prolife ration of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction damage.Transcranial magnetic stimulation(TMS)has recently emerged as a tool for inducing endogenous ...Prolife ration of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction damage.Transcranial magnetic stimulation(TMS)has recently emerged as a tool for inducing endogenous neural stem cell regeneration,but its underlying mechanisms remain unclea r In this study,we found that repetitive TMS effectively promotes the proliferation of oxygen-glucose deprived neural stem cells.Additionally,repetitive TMS reduced the volume of cerebral infa rction in a rat model of ischemic stro ke caused by middle cerebral artery occlusion,im p roved rat cognitive function,and promoted the proliferation of neural stem cells in the ischemic penumbra.RNA-sequencing found that repetitive TMS activated the Wnt signaling pathway in the ischemic penumbra of rats with cerebral ischemia.Furthermore,PCR analysis revealed that repetitive TMS promoted AKT phosphorylation,leading to an increase in mRNA levels of cell cycle-related proteins such as Cdk2 and Cdk4.This effect was also associated with activation of the glycogen synthase kinase 3β/β-catenin signaling pathway,which ultimately promotes the prolife ration of neural stem cells.Subsequently,we validated the effect of repetitive TMS on AKT phosphorylation.We found that repetitive TMS promoted Ca2+influx into neural stem cells by activating the P2 calcium channel/calmodulin pathway,thereby promoting AKT phosphorylation and activating the glycogen synthase kinase 3β/β-catenin pathway.These findings indicate that repetitive TMS can promote the proliferation of endogenous neural stem cells through a Ca2+influx-dependent phosphorylated AKT/glycogen synthase kinase 3β/β-catenin signaling pathway.This study has produced pioneering res ults on the intrinsic mechanism of repetitive TMS to promote neural function recove ry after ischemic stro ke.These results provide a stro ng scientific foundation for the clinical application of repetitive TMS.Moreover,repetitive TMS treatment may not only be an efficient and potential approach to support neurogenesis for further therapeutic applications,but also provide an effective platform for the expansion of neural stem cells.展开更多
文摘Our aim is to report 4 cases of central retinal vein occlusion following COVID-19 vaccine administration. In this case series, 4 patients between 23-32 years of age presented to us with unilateral central retinal vein occlusion after 2-15 days of getting vaccinated against COVID-19. One patient was a known case of hypertension and 1 was hypothyroid. All the patients had disc swelling, flame shaped haemorrhages, dilated and tortuous blood vessels in the retina. One patient had cystoid macular edema and was treated with intravitreal ranibizumab. As there were no positive systemic risk factors or incidents, COVID-19 vaccines might have an association with the central retinal vein occlusion in these cases. .
文摘Introduction:COVID-19 patients are susceptible to hypercoagulability,thromboembolic,and vasculitis state;central retinal artery occlusion(CRAO)could be caused by hyperviscosity syndrome,thromboembolic accidents,and vasculitis.Evolving case reports are correlating CRAO with COVID-19 patients.Our case series aims to reveal the prevalence of SARS-CoV-2 among CRAO patients under the COVID-19 pandemic.Methods:Medical records of all CRAO patients who attended our tertiary referral hospital,during COVID-19 local outbreak(March to November 2020),were reviewed.Respiratory tract samples were tested for SARS-CoV-2 by the validated Xpert Xpress SARS-CoV-2 assay.If patients were able to cooperate,oropharyngeal saliva samples were obtained.Otherwise,nasopharyngeal and deep throat swabs were taken by registered nurses.Results:A total of 15 CRAO patients(7 males,8 females)were identified during the 9-month study period.The mean age was 72.1-years(range 45-88 year).None of the patients were infected by SARS-CoV-2 before their CRAO disease episodes.Three patients had a history of CRAO over the contralateral eye.No patient was diagnosed with COVID-19 up to their last follow-up(mean 255.4 days,range 152-341 days).Without any COVID-19 positive case,correlation statistical tests on SARS-CoV-2 infection and CRAO were not established.Conclusions:Some of the presumed COVID-19 related CRAO cases may be just coincident with at-risk patients,as COVID-19 is prevalent across the world.More in-depth research,with adjustment to known confounding risk factors,is needed to establish a genuine correlation.
文摘Occlusion of vas deferens in uitro and in vivo with Nd2+ YAG laser of 100mW-1000mW was investigated. An optical fiber core in diameter of 200pm was inserted into the lumen of the uas uia a canula in & rabbits and 16 uasa deferens were irradiated in uiuo.The threshold lesion(denned as a half thickness of the uas wall being penetrated)at dijferent power and exposure duration was investigated in uitro. Temperature on the aduentitia was also determined.The uasa delerens were totally occluded in those irradiated with power of 800mW for 24 sec or with power of 1000mW for 16 sec 3 and 4 weeks after irradiation.The authors considered that it would be possible to insert percutaneously a fiber and coagulate vas deferens with laser for sterilization in the near future. However,more investigations are needed before it could be employed in the clinic.
文摘AIM： To establish models of portal vein occlusion of hepatic VX2 tumor in rabbits and to evaluate the value of multi-slice CT. METHODS： Forty New Zealand rabbits were divided into 4 groups according to digital table： Immediate group （group A; transplantation of tumor immediately after the portal vein occlusion）, 3-wk group （group B; transplantation of tumor at 3 wk after the portal vein occlusion）, negative control group （group C） and positive control group （group D）, 10 rabbits in each group. Hepatic VX2 tumor was transplanted with abdominalembedding innoculation immediately after the portal vein occlusion and at 3 wk after the portal vein occlusion. Meanwhile, they were divided into negative control group （Left external branch of portal vein was occluded by sham-operation, and left exite was embedded and inoculated pseudoly） and positive control group （Transplanted tumor did not suffer from the portal vein occlusion）. All rabbits were scanned with multi-slice CT. RESULTS： All 40 animals were employed in the final analysis without death. Tumor did not grow in both immediate group and 3-wk group. In 3-wk group, left endite was atrophied and growth of tumor was inhibited. The maximal diameter of tumor was significantly smaller than that in positive control group （2.55±0.46 vs 3.59±0.37 cm, t = 5.57, P 〈 0.001）. Incidences of metastasis in the liver and lung were lower in 3-wk group than those in positive control group （10% vs 400, and 90% vs 100%, respectively）. The expression intensities of the vascular endothelium growth factor （VEGF） in groups A, B, C and D were 0.10±0.06, 0.66±0.21, 0.28±0.09 and 1.48±0.32, respectively. VEGF expression level in the test group A was significantly lower than that in the negative control group C （t = 5.07; P 〈 0.001）.In addition, VEGF expression in the test group B was significantly lower than that in the positive control group D （t = 6.38; P 〈 0.001）. Scanning with multi-slice CT showed that displaying rate of hepatic artery branches was obviously lower in grade Ⅲ（40%） than that in grade Ⅰ（70%） and Ⅱ（100%） （P 〈 0.05）; but there was no significant difference in displaying rate of the portal vein at various grades. Values of blood flow （BF） of the liver, blood volume （BV）, mean transit time （MTT） and permeability of vascular surface （PS） were lower in the immediate group and 3-wk group than those in control groups, but values of hepatic arterial fraction （HAF） were increased. Significant positive correlations were existed between BF and BV （r = 0.905, P 〈 0.01）, and between BF and PS （r = 0.967, P 〈 0.01）, between BV and PS （r = 0.889, P 〈 0.01）. A significant negative correlation existed between PV and HAF （r = -0.768, P 〈 0.01）, between PS and HAF （r = -0.557, P 〈 0.01）. The values of BF, BV and PS had a positive correlation with VEGF （rBF = 0.842, rBV = 0.579, rPS = 0.811, P 〈 0.01） . However, there was no significant correlation between the values of MTT and HAF and the VEGF expression （rMTt = 0.066, rHAF = -0.027）. CONCLUSION： Ligating the left external branch of portal vein is an ideal way to establish models of portal vein occlusion in rabbits with hepatic VX2 tumor. Multi slice CT plays a key role in evaluating effect of portal vein occlusion.
基金supported by the National Natural Science Foundation of China,No.81771337(to RQY).
文摘β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to be highly related to ischemic stroke,the specific role and underlying mechanistic action ofβ2M are poorly understood.In this study,we established a rat model of focal cerebral ischemia by occlusion of the middle cerebral artery.We found thatβ2M levels in the cerebral spinal fluid,serum,and brain tissue were significantly increased in the acute period but gradually decreased during the recovery period.RNA interference was used to inhibitβ2M expression in the acute period of cerebral stroke.Tissue staining with 2,3,5-triphenyltetrazolium chloride and evaluation of cognitive function using the Morris water maze test demonstrated that decreasedβ2M expression in the ischemic penumbra reduced infarct volume and alleviated cognitive deficits,respectively.Notably,glial cell,caspase-1(p20),and Nod-like receptor pyrin domain containing 3(NLRP3)inflammasome activation as well as production of the inflammatory cytokines interleukin-1β,interleukin-6,and tumor necrosis factor-αwere also effectively inhibited byβ2M silencing.These findings suggest thatβ2M participates in brain injury and cognitive impairment in a rat model of ischemic stroke through activation of neuroinflammation associated with the NLRP3 inflammasome.
文摘Objective To predict the tolerance of the brain to carotid occlusion using noninvasive methods.Methods The peak(pV) and mean blood flow velocity(mV) of middle cerebral artery (MCA) and anterior cerebralartery (ACA) and pulsatility index (PI) were measured pre-and postoperatively with transcranial Dopplerultrasound diagnosis system(TCD) associated with the regional cerebral oxygen (rSO2) and somatosensory evokedpotentials (SSEPs) evaluation in 15 patients during manual compression, temporary occlusion and permanentocclusion Ol the carotid artery (CAO). Results There was no neurological delcit appearing during CAO in allthe cases. The mV of ipsilateral MCA and ACA reduced (31.79±13.59)% (12.58% ~56.16%) and reversed to 27.69±23.15cm/s and the rSO2 decreased (5.29±1.96)% (2%~9%). There was a linear correlation between percentchange in mV of ipsilateral MCA and rSO2 fall (P=0.0001). No more than 50% attenuation of SSEPs occurred inall the cases. The difference of PI in all recording time was not signilicant in our study. The pV was correlatedwith mV (P=0.0001). No variables were different significantly between compression and occlusion. Conclusion Afall in velocity by more than 70%, in rSO2 by more than 10% or in SSEPs amplitude by more than 50% iscompelling evidence for intolerance to CAO.
基金supported by the National Natural Science Foundation of China,Nos.81672261(to XH),81972151(to HZ),82372568(to JL)the Natural Science Foundation of Guangdong Province,Nos.2019A1515011106(to HZ),2023A1515030080(to JL)。
文摘Prolife ration of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction damage.Transcranial magnetic stimulation(TMS)has recently emerged as a tool for inducing endogenous neural stem cell regeneration,but its underlying mechanisms remain unclea r In this study,we found that repetitive TMS effectively promotes the proliferation of oxygen-glucose deprived neural stem cells.Additionally,repetitive TMS reduced the volume of cerebral infa rction in a rat model of ischemic stro ke caused by middle cerebral artery occlusion,im p roved rat cognitive function,and promoted the proliferation of neural stem cells in the ischemic penumbra.RNA-sequencing found that repetitive TMS activated the Wnt signaling pathway in the ischemic penumbra of rats with cerebral ischemia.Furthermore,PCR analysis revealed that repetitive TMS promoted AKT phosphorylation,leading to an increase in mRNA levels of cell cycle-related proteins such as Cdk2 and Cdk4.This effect was also associated with activation of the glycogen synthase kinase 3β/β-catenin signaling pathway,which ultimately promotes the prolife ration of neural stem cells.Subsequently,we validated the effect of repetitive TMS on AKT phosphorylation.We found that repetitive TMS promoted Ca2+influx into neural stem cells by activating the P2 calcium channel/calmodulin pathway,thereby promoting AKT phosphorylation and activating the glycogen synthase kinase 3β/β-catenin pathway.These findings indicate that repetitive TMS can promote the proliferation of endogenous neural stem cells through a Ca2+influx-dependent phosphorylated AKT/glycogen synthase kinase 3β/β-catenin signaling pathway.This study has produced pioneering res ults on the intrinsic mechanism of repetitive TMS to promote neural function recove ry after ischemic stro ke.These results provide a stro ng scientific foundation for the clinical application of repetitive TMS.Moreover,repetitive TMS treatment may not only be an efficient and potential approach to support neurogenesis for further therapeutic applications,but also provide an effective platform for the expansion of neural stem cells.
