Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that pla...Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that plays an important role in a broad range of cellular activities from calcium regulation to protein synthesis and trafficking.In neurons,the ER extends from the soma through the axon to presynaptic terminals,and throughout the dendritic arbor into as many as half of all postsynaptic dendritic spines at any given time(Falahati et al.,2022).展开更多
Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglio...Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.展开更多
Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for sign...Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.展开更多
针对Spines覆盖网络的逐跳传输特性,提出了一种具有较强网络动态适应性的可用带宽测量算法(band-width estimation linear regression,BELR).该算法是一元线性回归算法,采用传输消息大小和带宽限制的链路延时之间的线性关系来测量链路...针对Spines覆盖网络的逐跳传输特性,提出了一种具有较强网络动态适应性的可用带宽测量算法(band-width estimation linear regression,BELR).该算法是一元线性回归算法,采用传输消息大小和带宽限制的链路延时之间的线性关系来测量链路的可用带宽,使用可靠链路传输探测包,利用链路的单向延迟计算逐跳之间虚拟链路的带宽,所需带宽测量时间可减少一半.通过仿真分析了算法的性能,仿真结果表明,运用BELR算法可以在较短时间内得到比较准确的带宽估计,可适用于具有较大动态变化特性的覆盖网络可用带宽测量.展开更多
Traumatic brain injury is an important global public health problem.Traumatic brain injury not only causes neural cell death,but also induces dendritic spine degeneration.Spared neurons from cell death in the injured ...Traumatic brain injury is an important global public health problem.Traumatic brain injury not only causes neural cell death,but also induces dendritic spine degeneration.Spared neurons from cell death in the injured brain may exhibit dendrite damage,dendritic spine degeneration,mature spine loss,synapse loss,and impairment of activity.Dendritic degeneration and synapse loss may significantly contribute to functional impairments and neurological disorders following traumatic brain injury.Normal function of the nervous system depends on maintenance of the functionally intact synaptic connections between the presynaptic and postsynaptic spines from neurons and their target cells.During synaptic plasticity,the numbers and shapes of dendritic spines undergo dynamic reorganization.Enlargement of spine heads and the formation and stabilization of new spines are associated with long-term potentiation,while spine shrinkage and retraction are associated with long-term depression.Consolidation of memory is associated with remodeling and growth of preexisting synapses and the formation of new synapses.To date,there is no effective treatment to prevent dendritic degeneration and synapse loss.This review outlines the current data related to treatments targeting dendritic spines that propose to enhance spine remodeling and improve functional recovery after traumatic brain injury.The mechanisms underlying proposed beneficial effects of therapy targeting dendritic spines remain elusive,possibly including blocking activation of Cofilin induced by beta amyloid,Ras activation,and inhibition of GSK-3 signaling pathway.Further understanding of the molecular and cellular mechanisms underlying synaptic degeneration/loss following traumatic brain injury will advance the understanding of the pathophysiology induced by traumatic brain injury and may lead to the development of novel treatments for traumatic brain injury.展开更多
The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a model of light-weight material with high impact resistance.The complex and variable skeleton constructi...The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a model of light-weight material with high impact resistance.The complex and variable skeleton construction ('stereom') of body and spines of sea urchins consists of highly porous Mg-bearing calcium carbonate.This basically brittle material with pronounced single-crystal cleavage does not fracture by spontaneous catastrophic device failure but by graceful failure over the range of tens of millimeter of bulk compression instead.This was observed in bulk compression tests and blunt indentation experiments on regular,infiltrated and latex coated sea urchin spine segments.Microstructural characterization was carried out using X-ray computer tomography,optical and scanning electron microscopy.The behavior is interpreted to result from the hierarchic structure of sea urchin spines from the rnacroscale down to the nanoscale.Guidelines derived from this study see ceramics with layered porosity as a possible biomimetic construction for appropriate applications.展开更多
Sea urchin spines were chosen as a model system for biomimetic ceramics obtained using starch-blended slip casting. Porous alumina ceramics with cap-shaped layers with different alternating porosities were found to ha...Sea urchin spines were chosen as a model system for biomimetic ceramics obtained using starch-blended slip casting. Porous alumina ceramics with cap-shaped layers with different alternating porosities were found to have superior fracture behavior under bulk compression compared to ceramics with uniform porosity.They fail in a cascading manner,absorbing high amounts of energy during extended compression paths.The porosity variation in an otherwise single phase material mimicks the architectural microstructure design of sea urchin spines of Heterocentrotus mammillatus,which are promising model materials for impact protection.展开更多
Sevoflurane induces developmental neurotoxicity in mice;however,the underlying mechanisms remain unclear.Triggering receptor expressed on myeloid cells 2(TREM2)is essential for microglia-mediated synaptic refinement d...Sevoflurane induces developmental neurotoxicity in mice;however,the underlying mechanisms remain unclear.Triggering receptor expressed on myeloid cells 2(TREM2)is essential for microglia-mediated synaptic refinement during the early stages of brain development.We explored the effects of TREM2 on dendritic spine pruning during sevoflurane-induced developmental neurotoxicity in mice.Mice were anaesthetized with sevoflurane on postnatal days 6,8,and 10.Behavioral performance was assessed using the open field test and Morris water maze test.Genetic knockdown of TREM2 and overexpression of TREM2 by stereotaxic injection were used for mechanistic experiments.Western blotting,immunofluorescence,electron microscopy,three-dimensional reconstruction,Golgi staining,and whole-cell patch-clamp recordings were performed.Sevoflurane exposures upregulated the protein expression of TREM2,increased microglia-mediated pruning of dendritic spines,and reduced synaptic multiplicity and excitability of CA1 neurons.TREM2 genetic knockdown significantly decreased dendritic spine pruning,and partially aggravated neuronal morphological abnormalities and cognitive impairments in sevoflurane-treated mice.In contrast,TREM2 overexpression enhanced microglia-mediated pruning of dendritic spines and rescued neuronal morphological abnormalities and cognitive dysfunction.TREM2 exerts a protective role against neurocognitive impairments in mice after neonatal exposures to sevoflurane by enhancing microglia-mediated pruning of dendritic spines in CA1 neurons.This provides a potential therapeutic target in the prevention of sevoflurane-induced developmental neurotoxicity.展开更多
Acid-soluble collagen(ASC) and pepsin-soluble collagen(PSC) from the spine(ASC-SP and PSC-SP) and skull(ASC-SK and PSC-SK) of the skipjack tuna, Katsuwonus pelamis, were successfully isolated and characterized. The yi...Acid-soluble collagen(ASC) and pepsin-soluble collagen(PSC) from the spine(ASC-SP and PSC-SP) and skull(ASC-SK and PSC-SK) of the skipjack tuna, Katsuwonus pelamis, were successfully isolated and characterized. The yields of ASC-SP, PSC-SP, ASC-SK and PSC-SK were(2.47 ± 0.39)%,(5.62 ± 0.82)%,(3.57 ± 0.40)%, and(6.71 ± 0.81)%, respectively, on the basis of dry weight. The four collagens contained Gly(330.2-339.1 residues/1 000 residues) as the major amino acid, and their imino acid contents were between 168.8 and 178.2 residues/1 000 residues. Amino acid composition, SDS-PAGE, and FTIR investigations confirmed that ASC-SP and ASC-SK were mainly composed of type I collagen, and had higher contents of high-molecular weight cross-links than those of PSC-SK and PSC-SP. The FTIR investigation also certified all the collagens had triple helical structure. The denaturation temperatures of ASC-SK, PSC-SK, ASC-SP, and PSC-SP were 17.8, 16.6, 17.6, and 16.5 °C, respectively. All isolated collagens were soluble at acidic pH(1-5) and lost their solubilities when the NaCl concentration was above 2%(W/V). The isolated collagens from the spines and skulls of skipjack tuna could serve as an alternative source of collagens for further application in food, cosmetic, biomedical, and pharmaceutical industries.展开更多
Although the fracture behavior of sea urchin spines has been extensively investigated,there is as yet a lack of quantitative estimation on the effect of growth rings on the fracture properties of sea urchin spines.In ...Although the fracture behavior of sea urchin spines has been extensively investigated,there is as yet a lack of quantitative estimation on the effect of growth rings on the fracture properties of sea urchin spines.In sea urchin spines,much denser pores present in growth rings rather than porous layers.The tensile strength and fracture toughness of sea urchin spine samples with different numbers of growth rings are measured by the Boundary Effect Model(BEM).The experimental results of single-edge notched three-point bending tests indicate that the BEM is an appropriate method to estimate the fracture toughness of the present porous sea urchin spines,and the number of growth rings plays an important role in the fracture properties of spines.Specifically,the tensile strength and fracture toughness of sea urchin spines can be significantly improved with the increase in the number of growth rings,and their fracture toughness can even reach a relatively high value compared with some other porous materials with an identical porosity.The present research findings are expected to provide a fundamental insight into the design of high-performance bionic materials with a highly porous structure.展开更多
Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for sp...Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for spinal pathologies,leveraging AI and ML to enhance diagnostic accuracy through deep learning algorithms,enabling faster and more accurate detection of abnormalities.AIpowered robotics and surgical navigation systems improve implant placement precision and reduce complications in complex spine surgeries.Wearable devices and virtual platforms,designed with AI,offer personalized,adaptive therapies that improve treatment adherence and recovery outcomes.AI also enables preventive interventions by assessing spine condition risks early.Despite progress,challenges remain,including limited healthcare datasets,algorithmic biases,ethical concerns,and integration into existing systems.Interdisciplinary collaboration and explainable AI frameworks are essential to unlock AI’s full potential in spine care.Future developments include multimodal AI systems integrating imaging,clinical,and genetic data for holistic treatment approaches.AI and ML promise significant improvements in diagnostic accuracy,treatment personalization,service accessibility,and cost efficiency,paving the way for more streamlined and effective spine care,ultimately enhancing patient outcomes.展开更多
BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a ...BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a total of 13 procedures within our medical facility,including five performed under local anesthesia and eight performed under general anesthesia.The source of the ailment was ultimately identified as Enterobacter cloacae.After the last procedure,the patient's symptoms were alleviated,and the recovery process was satisfactory.Three months post-operation,the Japanese Orthopaedic Association scores had improved to 100%.Imageological examination revealed a satisfactory position of internal fixation,and the abnormal signals in the vertebral body and intervertebral space had been eliminated when compared to the pre-operative results.CONCLUSION The study demonstrates that the extreme lateral approach debridement combined with multiple VSD operations is a secure and successful method of treatment for recurrent spinal infection,providing an alternative to traditional surgery.展开更多
Aim of Study: Gonadal hormones exert a profound influence on the development, structure and function of the sexual organs. The testosterone is one of the androgens that plays an essential role in the development of se...Aim of Study: Gonadal hormones exert a profound influence on the development, structure and function of the sexual organs. The testosterone is one of the androgens that plays an essential role in the development of sexual organs in male mammals. Therefore, the present study was undertaken to evaluate the testosterone levels and developmental pattern of the penile spines and seminiferous tubules during early postnatal life of Wistar rats. Methods and Materials: At 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days after birth, penile and testicular tissues of male rats were dissected out and fixed for histological study and plasma testosterone levels were determined using high resolution chromatography. Results: An increase in the number of penile follicles, primarily in the distal region of the penis, was observed from postnatal days 14 to 42, followed by a gradual decrease. Penile spines were absent from birth until the first growth peak, which was observed at 42 postnatal days. Both testicular weight and the area of seminiferous tubules showed gradual increases before achieving their highest values at 42 postnatal days. Similarly, a gradual increase in testosterone levels was detected from day 28, with a peak at 42 postnatal days. Conclusions: These data show a temporal association between the development of the penile spines and testicular tissue with gradual increases in testosterone levels. These results may contribute to a better understanding of the behavioral, hormonal and morphological changes underlying sexual maturation in male rats.展开更多
BACKGROUND Cauda equina syndrome(CES)is characterized by a group of symptoms that may be caused by inflammation,spinal cord compression,venous congestion,or ischemia.This syndrome is commonly an indication for surgica...BACKGROUND Cauda equina syndrome(CES)is characterized by a group of symptoms that may be caused by inflammation,spinal cord compression,venous congestion,or ischemia.This syndrome is commonly an indication for surgical intervention but has not been determined as a postoperative complication following surgery for lumbar spine disease.CASE SUMMARY To report the case of a 54-year-old male patient who had CES following spinal surgery,with no obvious compression lesions found during re-exploration,suggesting that vascular insufficiency may have contributed to the condition.Furthermore,a series of urodynamic studies on bladder recovery patterns in such complications have also been investigated.CONCLUSION Postoperative CES requires urgent imaging and exploration to rule out compression;noncompressive cases,including vascular insufficiency may performed conservative management.展开更多
Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics cl...Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics clinical CPSS conditions by taking two sequential surgical procedures.Step 1:A plastic rod was inserted into the left L5 intervertebral foramen to produce a steady compression on the dorsal root ganglion(DRG)and the spinal nerve,a common cause of low back pain(LBP).Step 2:The rod was removed after 7 days when rats exhibited mechanical and heat hypersensitivity in the ipsilateral hindpaw,followed by a full L5 laminectomy to mimic spine decompression surgery in LBP patients.The retention of the rod induced a prolonged LBP-like behavior but was quickly resolved after rod removal without laminectomy.However,rats that received laminectomy after rod removal developed heightened mechanical and heat sensitivity in the hindpaw,impaired gait,and reduced spontaneous exploration activity,indicating CPSS.Patch clamp recording revealed a significant augmentation in the intrinsic excitability of smalldiameter DRG neurons in CPSS rats.Administration of Dermorphin[D-Arg2,Lys4](1–4)amide(DALDA,5mg/kg,i.p.),a peripherally acting mu-opioid receptor(MOR)-preferred agonist,attenuated pain hypersensitivity,capsaicin-induced[Ca^(2+)]i rising and the increased intrinsic excitability of DRG neurons from CPSS rats.Our findings suggest that this new model,which mirrors the nature of CPSS developed in patients,may be useful for future studies of the underlying mechanisms.展开更多
Neurofibromatosis type 1(NF1)is a genetic disorder affecting 1 in 3000 people due to heterozygous mutations in the NF1 gene.Patients with NF1 can develop multiple symptoms,such as neurofibromas,skin hyperpigmentation,...Neurofibromatosis type 1(NF1)is a genetic disorder affecting 1 in 3000 people due to heterozygous mutations in the NF1 gene.Patients with NF1 can develop multiple symptoms,such as neurofibromas,skin hyperpigmentation,and bone abnormalities,including tibial pseudarthrosis and spine deformity.Here,we aimed to elucidate the cellular origin and pathogenic mechanism of NF1 spine deformity.We explored the Prss56-Nf1 knockout(KO)mouse model that recapitulates neurofibromas and pseudarthrosis by carrying Nf1 gene inactivation in Prss56-expressing boundary cap cells,a neural crest subset,and their derivatives.Micro-CT analyses showed that Prss56-Nf1 KO mice exhibit spine deformity from 12 months of age,associated with vertebral anomalies reminiscent of patients with NF1.Fate mapping revealed a significant increase in OSX^(+)osteoblasts of the Prss56 lineage in vertebrae of Prss56-Nf1 KO mice.Increased traced Nf1-deficient cells correlated with increased vertebral bone volume and kyphosis spine curvature.Finally,we showed that treating Prss56-Nf1 KO mice with RAS-MAPK pathway inhibitors prevented spine deformity.Overall,the Prss56-Nf1 KO mouse model unravels the role of osteoblasts from the Prss56 lineage as the cellular origin of NF1 spine deformity and highlights RAS-MAPK pathway inhibition as a promising therapeutic strategy for preventing NF1 spine deformity.展开更多
Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divide...Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divided into two展开更多
Spinal cord injury and non-traumatic myelopathies are major causes of lifelong disability,yet conventional magnetic resonance imaging(MRI)can underestimate microstructural damage.Diffusion tensor imaging(DTI)and tract...Spinal cord injury and non-traumatic myelopathies are major causes of lifelong disability,yet conventional magnetic resonance imaging(MRI)can underestimate microstructural damage.Diffusion tensor imaging(DTI)and tractography map white-matter integrity by measuring fractional anisotropy(FA)and mean diffusivity(MD),but their adoption in spine imaging has been limited by long scan times and complex post-processing.Supsupin et al report a two-minute cervical DTI sequence integrated into routine MRI and applied to four representative pathologies–spinal cord contusion,metastatic compression,degenerative myelopathy,and multiple sclerosis–compared with five controls.Each lesion showed distinctive tractographic and quantitative patterns:For example,reduced FA with preserved MD in contusion and combined FA decrease and MD elevation in metastatic compression.These findings highlight the potential of tractography to improve diagnosis,guide surgical planning,and monitor treatment,while maintaining clinical feasibility.Remaining challenges include limited angular resolution,motion artifacts,and the need for multicenter validation and advanced reconstruction methods.This manuscript places the study in the context of current spinal diffusion imaging and outlines future directions toward routine,precision care.展开更多
基金supported by AHA Career Development Award 938683 (to PJD)NIH grant R01MH123700 (to MLD)
文摘Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that plays an important role in a broad range of cellular activities from calcium regulation to protein synthesis and trafficking.In neurons,the ER extends from the soma through the axon to presynaptic terminals,and throughout the dendritic arbor into as many as half of all postsynaptic dendritic spines at any given time(Falahati et al.,2022).
基金supported by the National Natural Science Foundation of China,No.82271115(to MY).
文摘Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.
基金supported by the National Natural Science Foundation of China(NSFC/RGC/JRF N_HKU735/21)Research Grant Council of Hong Kong,China(17102120,17108821,17103922,C1024-22GF,C7074-21G)+1 种基金Health and Medical Research Fund(HMRF 09200966)(to CSWL)FRQS Postdoctoral Fellowship(to AHKF).
文摘Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.
文摘针对Spines覆盖网络的逐跳传输特性,提出了一种具有较强网络动态适应性的可用带宽测量算法(band-width estimation linear regression,BELR).该算法是一元线性回归算法,采用传输消息大小和带宽限制的链路延时之间的线性关系来测量链路的可用带宽,使用可靠链路传输探测包,利用链路的单向延迟计算逐跳之间虚拟链路的带宽,所需带宽测量时间可减少一半.通过仿真分析了算法的性能,仿真结果表明,运用BELR算法可以在较短时间内得到比较准确的带宽估计,可适用于具有较大动态变化特性的覆盖网络可用带宽测量.
文摘Traumatic brain injury is an important global public health problem.Traumatic brain injury not only causes neural cell death,but also induces dendritic spine degeneration.Spared neurons from cell death in the injured brain may exhibit dendrite damage,dendritic spine degeneration,mature spine loss,synapse loss,and impairment of activity.Dendritic degeneration and synapse loss may significantly contribute to functional impairments and neurological disorders following traumatic brain injury.Normal function of the nervous system depends on maintenance of the functionally intact synaptic connections between the presynaptic and postsynaptic spines from neurons and their target cells.During synaptic plasticity,the numbers and shapes of dendritic spines undergo dynamic reorganization.Enlargement of spine heads and the formation and stabilization of new spines are associated with long-term potentiation,while spine shrinkage and retraction are associated with long-term depression.Consolidation of memory is associated with remodeling and growth of preexisting synapses and the formation of new synapses.To date,there is no effective treatment to prevent dendritic degeneration and synapse loss.This review outlines the current data related to treatments targeting dendritic spines that propose to enhance spine remodeling and improve functional recovery after traumatic brain injury.The mechanisms underlying proposed beneficial effects of therapy targeting dendritic spines remain elusive,possibly including blocking activation of Cofilin induced by beta amyloid,Ras activation,and inhibition of GSK-3 signaling pathway.Further understanding of the molecular and cellular mechanisms underlying synaptic degeneration/loss following traumatic brain injury will advance the understanding of the pathophysiology induced by traumatic brain injury and may lead to the development of novel treatments for traumatic brain injury.
文摘The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a model of light-weight material with high impact resistance.The complex and variable skeleton construction ('stereom') of body and spines of sea urchins consists of highly porous Mg-bearing calcium carbonate.This basically brittle material with pronounced single-crystal cleavage does not fracture by spontaneous catastrophic device failure but by graceful failure over the range of tens of millimeter of bulk compression instead.This was observed in bulk compression tests and blunt indentation experiments on regular,infiltrated and latex coated sea urchin spine segments.Microstructural characterization was carried out using X-ray computer tomography,optical and scanning electron microscopy.The behavior is interpreted to result from the hierarchic structure of sea urchin spines from the rnacroscale down to the nanoscale.Guidelines derived from this study see ceramics with layered porosity as a possible biomimetic construction for appropriate applications.
基金funded by European sources within the ERASMUS-SOCRATES program
文摘Sea urchin spines were chosen as a model system for biomimetic ceramics obtained using starch-blended slip casting. Porous alumina ceramics with cap-shaped layers with different alternating porosities were found to have superior fracture behavior under bulk compression compared to ceramics with uniform porosity.They fail in a cascading manner,absorbing high amounts of energy during extended compression paths.The porosity variation in an otherwise single phase material mimicks the architectural microstructure design of sea urchin spines of Heterocentrotus mammillatus,which are promising model materials for impact protection.
基金National Natural Science Foundation of China(82072130 and 82001126)Key Medical Research Projects in Jiangsu Province(ZD2022021)+6 种基金Six Talent Peaks Project in Jiangsu Province(WSN-022)Suzhou Clinical Medical Center for Anaesthesiology(Szlcyxzxj202102)Jiangsu Medical Association Anaesthesia Research Project(SYH-32021-0036(2021031))Suzhou Medical Health Science and Technology Innovation Project(SKY2022136)Jiangsu Provincial Colleges of Natural Science General Program(22KJD320002)Health Talent Plan Project in Suzhou(GSWS2022007)Gusu Health Talent Project of Soochow(GSWS2021062).
文摘Sevoflurane induces developmental neurotoxicity in mice;however,the underlying mechanisms remain unclear.Triggering receptor expressed on myeloid cells 2(TREM2)is essential for microglia-mediated synaptic refinement during the early stages of brain development.We explored the effects of TREM2 on dendritic spine pruning during sevoflurane-induced developmental neurotoxicity in mice.Mice were anaesthetized with sevoflurane on postnatal days 6,8,and 10.Behavioral performance was assessed using the open field test and Morris water maze test.Genetic knockdown of TREM2 and overexpression of TREM2 by stereotaxic injection were used for mechanistic experiments.Western blotting,immunofluorescence,electron microscopy,three-dimensional reconstruction,Golgi staining,and whole-cell patch-clamp recordings were performed.Sevoflurane exposures upregulated the protein expression of TREM2,increased microglia-mediated pruning of dendritic spines,and reduced synaptic multiplicity and excitability of CA1 neurons.TREM2 genetic knockdown significantly decreased dendritic spine pruning,and partially aggravated neuronal morphological abnormalities and cognitive impairments in sevoflurane-treated mice.In contrast,TREM2 overexpression enhanced microglia-mediated pruning of dendritic spines and rescued neuronal morphological abnormalities and cognitive dysfunction.TREM2 exerts a protective role against neurocognitive impairments in mice after neonatal exposures to sevoflurane by enhancing microglia-mediated pruning of dendritic spines in CA1 neurons.This provides a potential therapeutic target in the prevention of sevoflurane-induced developmental neurotoxicity.
基金supported by the National Natural Science Foundation of China(No.31001109)the Public Projects of Zhejiang Province(No.2014C33034)the Special Program for the Science and Technology Plan of Zhejiang Province(Nos.2009C03017-2,2011C02003)
文摘Acid-soluble collagen(ASC) and pepsin-soluble collagen(PSC) from the spine(ASC-SP and PSC-SP) and skull(ASC-SK and PSC-SK) of the skipjack tuna, Katsuwonus pelamis, were successfully isolated and characterized. The yields of ASC-SP, PSC-SP, ASC-SK and PSC-SK were(2.47 ± 0.39)%,(5.62 ± 0.82)%,(3.57 ± 0.40)%, and(6.71 ± 0.81)%, respectively, on the basis of dry weight. The four collagens contained Gly(330.2-339.1 residues/1 000 residues) as the major amino acid, and their imino acid contents were between 168.8 and 178.2 residues/1 000 residues. Amino acid composition, SDS-PAGE, and FTIR investigations confirmed that ASC-SP and ASC-SK were mainly composed of type I collagen, and had higher contents of high-molecular weight cross-links than those of PSC-SK and PSC-SP. The FTIR investigation also certified all the collagens had triple helical structure. The denaturation temperatures of ASC-SK, PSC-SK, ASC-SP, and PSC-SP were 17.8, 16.6, 17.6, and 16.5 °C, respectively. All isolated collagens were soluble at acidic pH(1-5) and lost their solubilities when the NaCl concentration was above 2%(W/V). The isolated collagens from the spines and skulls of skipjack tuna could serve as an alternative source of collagens for further application in food, cosmetic, biomedical, and pharmaceutical industries.
基金This work was supported by the National Natural Science Foundation of China[Grant No.51902043]the Fundamental Research Funds for the Central Universities[Grant No.N2102007,and N2102002]。
文摘Although the fracture behavior of sea urchin spines has been extensively investigated,there is as yet a lack of quantitative estimation on the effect of growth rings on the fracture properties of sea urchin spines.In sea urchin spines,much denser pores present in growth rings rather than porous layers.The tensile strength and fracture toughness of sea urchin spine samples with different numbers of growth rings are measured by the Boundary Effect Model(BEM).The experimental results of single-edge notched three-point bending tests indicate that the BEM is an appropriate method to estimate the fracture toughness of the present porous sea urchin spines,and the number of growth rings plays an important role in the fracture properties of spines.Specifically,the tensile strength and fracture toughness of sea urchin spines can be significantly improved with the increase in the number of growth rings,and their fracture toughness can even reach a relatively high value compared with some other porous materials with an identical porosity.The present research findings are expected to provide a fundamental insight into the design of high-performance bionic materials with a highly porous structure.
文摘Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for spinal pathologies,leveraging AI and ML to enhance diagnostic accuracy through deep learning algorithms,enabling faster and more accurate detection of abnormalities.AIpowered robotics and surgical navigation systems improve implant placement precision and reduce complications in complex spine surgeries.Wearable devices and virtual platforms,designed with AI,offer personalized,adaptive therapies that improve treatment adherence and recovery outcomes.AI also enables preventive interventions by assessing spine condition risks early.Despite progress,challenges remain,including limited healthcare datasets,algorithmic biases,ethical concerns,and integration into existing systems.Interdisciplinary collaboration and explainable AI frameworks are essential to unlock AI’s full potential in spine care.Future developments include multimodal AI systems integrating imaging,clinical,and genetic data for holistic treatment approaches.AI and ML promise significant improvements in diagnostic accuracy,treatment personalization,service accessibility,and cost efficiency,paving the way for more streamlined and effective spine care,ultimately enhancing patient outcomes.
基金Supported by Natural Science Foundation of Shandong Province,No.ZR2023MH331.
文摘BACKGROUND A case study of multiple distinct levels of skipped thoracolumbar spine infection was reported in which 13 successful vacuum sealing drainage(VSD)surgeries were treated.CASE SUMMARY The patient underwent a total of 13 procedures within our medical facility,including five performed under local anesthesia and eight performed under general anesthesia.The source of the ailment was ultimately identified as Enterobacter cloacae.After the last procedure,the patient's symptoms were alleviated,and the recovery process was satisfactory.Three months post-operation,the Japanese Orthopaedic Association scores had improved to 100%.Imageological examination revealed a satisfactory position of internal fixation,and the abnormal signals in the vertebral body and intervertebral space had been eliminated when compared to the pre-operative results.CONCLUSION The study demonstrates that the extreme lateral approach debridement combined with multiple VSD operations is a secure and successful method of treatment for recurrent spinal infection,providing an alternative to traditional surgery.
文摘Aim of Study: Gonadal hormones exert a profound influence on the development, structure and function of the sexual organs. The testosterone is one of the androgens that plays an essential role in the development of sexual organs in male mammals. Therefore, the present study was undertaken to evaluate the testosterone levels and developmental pattern of the penile spines and seminiferous tubules during early postnatal life of Wistar rats. Methods and Materials: At 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days after birth, penile and testicular tissues of male rats were dissected out and fixed for histological study and plasma testosterone levels were determined using high resolution chromatography. Results: An increase in the number of penile follicles, primarily in the distal region of the penis, was observed from postnatal days 14 to 42, followed by a gradual decrease. Penile spines were absent from birth until the first growth peak, which was observed at 42 postnatal days. Both testicular weight and the area of seminiferous tubules showed gradual increases before achieving their highest values at 42 postnatal days. Similarly, a gradual increase in testosterone levels was detected from day 28, with a peak at 42 postnatal days. Conclusions: These data show a temporal association between the development of the penile spines and testicular tissue with gradual increases in testosterone levels. These results may contribute to a better understanding of the behavioral, hormonal and morphological changes underlying sexual maturation in male rats.
文摘BACKGROUND Cauda equina syndrome(CES)is characterized by a group of symptoms that may be caused by inflammation,spinal cord compression,venous congestion,or ischemia.This syndrome is commonly an indication for surgical intervention but has not been determined as a postoperative complication following surgery for lumbar spine disease.CASE SUMMARY To report the case of a 54-year-old male patient who had CES following spinal surgery,with no obvious compression lesions found during re-exploration,suggesting that vascular insufficiency may have contributed to the condition.Furthermore,a series of urodynamic studies on bladder recovery patterns in such complications have also been investigated.CONCLUSION Postoperative CES requires urgent imaging and exploration to rule out compression;noncompressive cases,including vascular insufficiency may performed conservative management.
基金supported by the Neurosurgery Pain Research Institute at Johns Hopkins University and by the Lehner Family Foundation.
文摘Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics clinical CPSS conditions by taking two sequential surgical procedures.Step 1:A plastic rod was inserted into the left L5 intervertebral foramen to produce a steady compression on the dorsal root ganglion(DRG)and the spinal nerve,a common cause of low back pain(LBP).Step 2:The rod was removed after 7 days when rats exhibited mechanical and heat hypersensitivity in the ipsilateral hindpaw,followed by a full L5 laminectomy to mimic spine decompression surgery in LBP patients.The retention of the rod induced a prolonged LBP-like behavior but was quickly resolved after rod removal without laminectomy.However,rats that received laminectomy after rod removal developed heightened mechanical and heat sensitivity in the hindpaw,impaired gait,and reduced spontaneous exploration activity,indicating CPSS.Patch clamp recording revealed a significant augmentation in the intrinsic excitability of smalldiameter DRG neurons in CPSS rats.Administration of Dermorphin[D-Arg2,Lys4](1–4)amide(DALDA,5mg/kg,i.p.),a peripherally acting mu-opioid receptor(MOR)-preferred agonist,attenuated pain hypersensitivity,capsaicin-induced[Ca^(2+)]i rising and the increased intrinsic excitability of DRG neurons from CPSS rats.Our findings suggest that this new model,which mirrors the nature of CPSS developed in patients,may be useful for future studies of the underlying mechanisms.
基金Association Neurofibromatoses et Recklinghausen(C.C)Agence Nationale de la Recherche-18-CE14-0033(C.C.,P.T.)+2 种基金Agence Nationale de la Recherche-21-CE18-007-01(C.C.,P.T.)US Department of the Army NF220019(C.C.)supported by a PhD fellowship from the University Paris-Est Créteil and the Fondation pour la Recherche Médicale(FRM)(FDT202304016600 to FK and ECO202306017399 to CG)。
文摘Neurofibromatosis type 1(NF1)is a genetic disorder affecting 1 in 3000 people due to heterozygous mutations in the NF1 gene.Patients with NF1 can develop multiple symptoms,such as neurofibromas,skin hyperpigmentation,and bone abnormalities,including tibial pseudarthrosis and spine deformity.Here,we aimed to elucidate the cellular origin and pathogenic mechanism of NF1 spine deformity.We explored the Prss56-Nf1 knockout(KO)mouse model that recapitulates neurofibromas and pseudarthrosis by carrying Nf1 gene inactivation in Prss56-expressing boundary cap cells,a neural crest subset,and their derivatives.Micro-CT analyses showed that Prss56-Nf1 KO mice exhibit spine deformity from 12 months of age,associated with vertebral anomalies reminiscent of patients with NF1.Fate mapping revealed a significant increase in OSX^(+)osteoblasts of the Prss56 lineage in vertebrae of Prss56-Nf1 KO mice.Increased traced Nf1-deficient cells correlated with increased vertebral bone volume and kyphosis spine curvature.Finally,we showed that treating Prss56-Nf1 KO mice with RAS-MAPK pathway inhibitors prevented spine deformity.Overall,the Prss56-Nf1 KO mouse model unravels the role of osteoblasts from the Prss56 lineage as the cellular origin of NF1 spine deformity and highlights RAS-MAPK pathway inhibition as a promising therapeutic strategy for preventing NF1 spine deformity.
文摘Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divided into two
文摘Spinal cord injury and non-traumatic myelopathies are major causes of lifelong disability,yet conventional magnetic resonance imaging(MRI)can underestimate microstructural damage.Diffusion tensor imaging(DTI)and tractography map white-matter integrity by measuring fractional anisotropy(FA)and mean diffusivity(MD),but their adoption in spine imaging has been limited by long scan times and complex post-processing.Supsupin et al report a two-minute cervical DTI sequence integrated into routine MRI and applied to four representative pathologies–spinal cord contusion,metastatic compression,degenerative myelopathy,and multiple sclerosis–compared with five controls.Each lesion showed distinctive tractographic and quantitative patterns:For example,reduced FA with preserved MD in contusion and combined FA decrease and MD elevation in metastatic compression.These findings highlight the potential of tractography to improve diagnosis,guide surgical planning,and monitor treatment,while maintaining clinical feasibility.Remaining challenges include limited angular resolution,motion artifacts,and the need for multicenter validation and advanced reconstruction methods.This manuscript places the study in the context of current spinal diffusion imaging and outlines future directions toward routine,precision care.
