AIM To investigate potential effects of poly I:C on mucosal injury and epithelial barrier disruption in dextran sulfate sodium(DSS)-induced acute colitis.METHODS Thirty C57BL/6 mice were given either regular drinking ...AIM To investigate potential effects of poly I:C on mucosal injury and epithelial barrier disruption in dextran sulfate sodium(DSS)-induced acute colitis.METHODS Thirty C57BL/6 mice were given either regular drinking water(control group) or 2%(w/v) DSS drinking water(model and poly I:C groups) ad libitum for 7 d. Poly I:C was administrated subcutaneously (20 μg/mouse) 2 h prior to DSS induction in mice of the poly I:C group. Severity of colitis was evaluated by disease activity index, body weight, colon length, histology and myeloperoxidase (MPO) activity, as well as the production of proinflammatory cytokines, including tumor necrosis factor-α(TNF-α), interleukin 17(IL-17) and interferon-γ (IFN-γ). Intestinal permeability was analyzed by the fluorescein isothiocyanate labeleddextran (FITC-D) method. Ultrastructural features of the colon tissue were observed under electron microscopy. Expressions of tight junction(TJ) proteins, including zo-1, occludin and claudin-1, were measured by immunohistochemistry/immunofluorescence, Western blot and real-time quantitative polymerase chain reaction(RT-qPCR).RESULTS DSS caused significant damage to the colon tissue in the model group. Administration of poly I:C dramatically protected against DSS-induced colitis, as demonstrated by less body weight loss, lower disease activity index score, longer colon length, colonic MPO activity, and improved macroscopic and histological scores. It also ameliorated DSS-induced ultrastructural changes of the colon epithelium, as observed under scanning electron microscopy, as well as FITC-D permeability. The m RNA and protein expressions of TJ protein, zo-1, occludin and claudin-1 were also found to be significantly enhanced in the poly I:C group, as determined by immunohistochemistry/immunofluorescence, Western blot and RT-q PCR. By contrast, poly I:C pretreatment markedly reversed the DSS-induced up-regulated expressions of the inflammatory cytokines TNF-α, IL-17 and IFN-γ.CONCLUSION Our study suggested that poly I:C may protect against DSS-induced colitis through maintaining integrity of the epithelial barrier and regulating innate immune responses, which may shed light on the therapeutic potential of poly I:C in human colitis.展开更多
Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system.Therefore,based on the regenerative capacity of stem cells,transplantation therapies of various stem ce...Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system.Therefore,based on the regenerative capacity of stem cells,transplantation therapies of various stem cells have been tested in basic research and preclinical trials,and some have shown great prospects.This manuscript overviews the cellular and molecular characteristics of embryonic stem cells,induced pluripotent stem cells,neural stem cells,retinal stem/progenitor cells,mesenchymal stem/stromal cells,and their derivatives in vivo and in vitro as sources for regenerative therapy.These cells have all been considered as candidates to treat several major neurological disorders and diseases,owing to their self-renewal capacity,multi-directional differentiation,neurotrophic properties,and immune modulation effects.We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases,including Parkinson＇s disease,Alzheimer＇s disease,and age-related macular degeneration,as well as traumatic brain injury and glioblastoma.In spite of a few unsuccessful cases,risks of tumorigenicity,and ethical concerns,most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease.In summary,these emerging findings in regenerative medicine are likely to contribute to breakthroughs in the treatment of neurological disorders.Thus,stem cells are a promising candidate for the treatment of nervous system diseases.展开更多
A new triterpene glycoside, leucospilotaside C, along with two known saponin, was isolated from sea cucumber Holothuria leucospilota collected from the South China Sea, and its structure was elucidated as 3-0-{4′-O-s...A new triterpene glycoside, leucospilotaside C, along with two known saponin, was isolated from sea cucumber Holothuria leucospilota collected from the South China Sea, and its structure was elucidated as 3-0-{4′-O-sodiumsulfate-β′-D-xylopyranosyl}- holosta-22,25-epoxy-9-ene-3β,12α,17α-triol （1） by extensive spectroscopic analysis and chemical methods. The glycosides have the same triterpene aglycone, but differ in the oligosaccharide moieties.展开更多
BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyper...BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyperalgesia and neuropathic pain. Participation of the glutamate-glutamine cycle in central sensitization of the spinal cord remains poorly understood. OBJECTIVE： To determine whether the astrocyte-neuronal glutamate-glutamine cycle is involved in formalin-induced central sensitization in the spinal cord. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Orthopedics, Second Hospital, Lanzhou University, China from September 2007 to August 2008. MATERIALS： Methionine sulfoximine （MSO, 0.1 mmol/L）, glutamine （0.25 mmol/L）, and formalin were used for this study. METHODS： A total of 43 male, Sprague Dawley rats, aged 4 months, were randomly assigned to a sham operation group （n = 6） and a model group （n = 37）. Rats in the model group received intrathecal infusion in the spinal cord. 7 days later, 37 model rats were randomly divided into PBS, MSO, glutamine, MSO ＋ glutamine and formalin subcutaneous injection alone groups. The PBS, MSO, glutamine, MSO ＋ glutamine groups were respectively intrathecally injected with PBS, MSO, glutamine, MSO ＋ glutamine （50 μL each）, and then infused with 10 μL of saline. Rats from the sham operation group were not subjected to intrathecal infusion in the spinal cord. At 15 minutes after intrathecal injection, a rat model of formalin-induced inflammatory pain was established by subcutaneous injection of 5% formalin （50 μL） in the left hindpaw. MAIN OUTCOME MEASURES： Changes in spontaneous nociceptive behavior （licking/biting or flinching） were observed following formalin injection into the rat hindpaw. RESULTS： Compared with the PBS group, duration of licking/biting was significantly shortened, and flinching frequency was significantly diminished in the MSO group （P 〈 0.05）. Compared with the MSO group, duration of licking/biting was significantly prolonged, and flinching frequency was significantly increased in the MSO ＋ glutamine group （P 〈 0.05）. There was no significant difference in inflammatory pain behaviors among the sham operation, PBS, glutamine, MSO ＋ glutamine, and formalin subcutaneous injection alone groups （P 〉 0.05）. CONCLUSION： The astrocyte-neuronal glutamate-glutamine cycle in the spinal cord was shown to be involved in central sensitization induced by formalin subcutaneous injection into the hindpaw.展开更多
Objective to explore dynamic characteristics of the HIV mother to child transmission （MTCT） epidemic in China.Methods A deterministic dynamic transmission model was used to determine the effect of key parameters on ...Objective to explore dynamic characteristics of the HIV mother to child transmission （MTCT） epidemic in China.Methods A deterministic dynamic transmission model was used to determine the effect of key parameters on the likely long-term trends of the HIV MTCT epidemic in China.Matlab 7.0 was used to develop the model.Results The number of the susceptibles （S）,the transmission rate （β）,and the screening proportion （α） of HIV positive pregnant women have the greatest impact on the HIV MTCT epidemic in China.The growth of the MTCT epidemic in China could not be controlled only by decreasing the MTCT transmission rate.The prevalence of HIV positive women should be reduced and more pregnant women should be tested for HIV.Conclusion Prevention of MTCT （PMTCT） should focus not only on the reduction of HIV transmission rates and incidences of HIV among women but also on the increase of HIV testing for pregnant women.The most cost-effective PMTCT means for China should be investigated in future studies.展开更多
The flotation kinetics of different size fractions of conventional and nanobubble(NB) flotation were compared to investigate the effect of NBs on the flotation performance of various coal particle sizes. Six flotation...The flotation kinetics of different size fractions of conventional and nanobubble(NB) flotation were compared to investigate the effect of NBs on the flotation performance of various coal particle sizes. Six flotation kinetics models were selected to fit the flotation data, and NBs were observed on a hydrophobic surface under hydrodynamic cavitation by atomic force microscope scanning. Flotation results indicated that the best flotation performance of size fraction at-0.125+0.074 mm can be obtained either in conventional or NB flotation. NBs increase the combustible recovery of almost all the size fractions, but they increase the product ash content of-0.25+0.074 mm and reduce the product ash content of-0.045 mm at the same time. The first-order models can be used to fit the flotation data in conventional and NB flotation, and the classical first-order model is the most suitable one. NBs considerably enhance flotation rate on coarse size fraction(-0.5+0.25 mm) but decrease the flotation rate of the medium size(-0.25+0.074 mm). The improvement of flotation speed on fine coal particles(-0.074 mm) is probably the reason for the improved performance of raw sample flotation.展开更多
BACKGROUND： Studies have shown that cell death can activate proliferation of endogenous neural stem cells and promote newly generated cells to migrate to a lesion site. OBJECTIVE： To observe regeneration and differe...BACKGROUND： Studies have shown that cell death can activate proliferation of endogenous neural stem cells and promote newly generated cells to migrate to a lesion site. OBJECTIVE： To observe regeneration and differentiation of neural cells following spinal cord injury in adult rats and to quantitatively analyze the newly differentiated cells. DESIGN, TIME AND SETTING： A cell biology experiment was performed at the Institute of Orthopedics and Medical Experimental Center, Lanzhou University, between August 2005 and October 2007. MATERIALS： Fifty adult, Wistar rats of both sexes; 5-bromodeoxyuridine （BrdU, Sigma, USA）; antibodies against neuron-specific enolase, glial fibrillary acidic protein, and myelin basic protein （Chemicon, USA）. METHODS： Twenty-five rats were assigned to the spinal cord injury group and received a spinal cord contusion injury. Materials were obtained at day 1, 3, 7, 15, and 29 after injury, with 5 rats for each time point. Twenty-five rats were sham-treated by removing the lamina of the vertebral arch without performing a contusion. MAIN OUTCOME MEASURES： The phenotype of BrdU-labeled cells, i.e., expression and distribution of surface markers for neurons （neuron-specific enolase）, astrocytes （glial fibrillary acidic protein）, and oligodendrocytes （myelin basic protein）, were identified with immunofluorescence double-labeling. Confocal microscopy was used to detect double-labeled cells by immunofluorescence. Quantitative analysis of newly generated cells was performed with stereological counting methods. RESULTS： There was significant cell production and differentiation after adult rat spinal cord injury. The quantity of newly-generated BrdU-labeled cells in the spinal cord lesion was 75-fold greater than in the corresponding area of control animals. Endogenous neural precursor cells differentiated into astrocytes and oligodendrocytes, however spontaneous neuronal differentiation was not detected. Between 7 and 29 d after spinal cord injury, newly generated cells expressed increasingly more mature oligodendrocyte and astrocyte markers. CONCLUSION： Spinal cord injury is a direct inducer of regeneration and differentiation of neural cells. Endogenous neural precursor cells can differentiate into astrocytes and oligodendrocytes following adult rat spinal cord injury.展开更多
A sliding mode variable structure control （SMVSC） based on a coordinating optimization algorithm has been developed. Steady state error and control switching frequency are used to constitute the system performance i...A sliding mode variable structure control （SMVSC） based on a coordinating optimization algorithm has been developed. Steady state error and control switching frequency are used to constitute the system performance indexes in the coordinating optimization, while the tuning rate of boundary layer width （BLW） is employed as the optimization parameter. Based on the mathematical relationship between the BLW and steady-state error, an optimized BLW tuning rate is added to the nonlinear control term of SMVSC. Simulation experiment results applied to the positioning control of an electro-hydraulic servo system show the comprehensive superiority in dynamical and static state performance by using the proposed controller is better than that by using SMVSC without optimized BLW tuning rate. This succeeds in coordinately considering both chattering reduction and high-precision control realization in SMVSC.展开更多
Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the facto...Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the factors that affect the rooting of hybrid larch shoots-activated carbon,vitamin B1,sucrose,glycine,glutamic acid(Glu),cysteine,pH,and induction time in the dark and indole-3-butyric acid(IBA).Variance analysis showed that the effects of sucrose concentration on rooting rate,survival rate,and average root number,pH on the average number of roots;and Glu on survival rate were all significant(p<0.05)when compared to the mock treatments.Among all of the 45 treatments,the highest rooting rate was 90%,the highest survival rate was 100%,and the highest average root number was 11.8.The theoretically optimal procedure of in vitro root induction of hybrid larch shoots is shoot induction on L9 modified medium(pH 6.7)containing 2 mg.L^(-1)naphthalene acetic acid,0.25 mg.L^(-1)IBA,1/3 macroelements,7.5 g.L^(-1)sucrose,and 5 mg.L^(-1)Glu for 8 days,and then root induction on L9 modified medium without auxin.展开更多
At present,there are a large number of informal landfills to be treated all over the country. Under the condition of limited treatment funds,it is necessary to prioritize the treatment of informal landfills. In this p...At present,there are a large number of informal landfills to be treated all over the country. Under the condition of limited treatment funds,it is necessary to prioritize the treatment of informal landfills. In this paper,the pollution risk of waste dump,surrounding soil,groundwater and surface water is analyzed,and a set of comprehensive risk assessment method system of informal landfill is established,which could provide reference for decision making department deciding landfill disposal.展开更多
Progesterone is an efficient candidate for treating stroke and traumatic brain damage. The current study was designed to investigate the effects of pro gesterone on glucose transporter proteins （GLUT1 and GLUT3） dur...Progesterone is an efficient candidate for treating stroke and traumatic brain damage. The current study was designed to investigate the effects of pro gesterone on glucose transporter proteins （GLUT1 and GLUT3） during hypoxicischemic injury in a neo natal rat model. We demonstrated strong staining for GLUT1 in the walls of blood vessels and GLUT3 im munoreactivity in hippocampal neurons after hypoxia ischemia. Hypoxiaischemia elevated GLUT1 and GLUT3 at both the mRNA and protein levels in the hippocampus, and pretreatment with progesterone （8 mg/kg） further enhanced their accumulation until 24 h after hypoxicischemic injury. These results showed that progesterone treatment induced the accumula tion of both GLUT1 and GLUT3 transporters, and an energycompensation mechanism may be involved in the neuroprotective effect of progesterone during hy poxicischemic injury after cerebral ischemic attacks.展开更多
Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene ...Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.展开更多
The retina is one of the most essential elements of vision pathway in vertebrate. The dysplasia of retina cause congenital blindness or vision disability in individuals, and the misbalance in adult retinal vascular ho...The retina is one of the most essential elements of vision pathway in vertebrate. The dysplasia of retina cause congenital blindness or vision disability in individuals, and the misbalance in adult retinal vascular homeostasis leads to neo adults, such as diabetic retinopathy or age-related macular degeneration. Many developmental signaling pathways are involved in the process of retinal development and vascular homeostasis. Among them, Notch signaling pathway has long been studied, and Notch signaling-interfered mouse models show both neural retina dysplasia and vascular abnormality. In this review, we discuss the roles of Notch signaling in the maintenance of retinal progenitor cells, specification of retinal neurons and glial cells, and the sustaining of retina vascular homeostasis, especially from the aspects of conditional knockout mouse models. The potential of Notch signal manipulation may provide a powerful cell fate- and neovascularization-controUing tool that could have important applications in treatment of retinal diseases.展开更多
Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms re...Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms remain unclear.In this study,we genetically targeted Notch signaling by disrupting the transcription factor recombination signal binding protein-JK(RBP-J),to reveal its role in regulation of macrophages during the unilateral ureteral obstruction(UUO)-induced murine renal fibrosis.Myeloid-specific disruption of RBP-J attenuated renal fibrosis with reduced extracellular matrix deposition and myofibroblast activation,as well as attenuated epithelial-mesenchymal transition,likely owing to the reduced expression of TGF-β.Mean while,RBP-J deletion significantly hampered macrophage infiltration and activation in fibrotic kidney,although their proliferation appeared unaltered.By using macrophage clearance experiment,we found that kidney resident macrophages made negligible contribution,but bone marrow(BM)-derived macrophages played a major role in renal fibrogenesis.Further mechanistic analyses showed that Notch blockade reduced monocyte emigration from BM by down-regulating CCR2 expression.Finally,we found that myeloid-specific Notch activation aggravated renal fibrosis,which was mediated by CCR2^+macrophages infiltration.In summary,our data have unveiled that myeloid-specific targeting of Notch could ameliorate renal fibrosis by regulating BM-derived macrophages recruitment and activation,providing a novel strategy for intervention of this disease.展开更多
基金the Scientific Research Foundation of HealthDepartment of Hebei Province,No.20160483
文摘AIM To investigate potential effects of poly I:C on mucosal injury and epithelial barrier disruption in dextran sulfate sodium(DSS)-induced acute colitis.METHODS Thirty C57BL/6 mice were given either regular drinking water(control group) or 2%(w/v) DSS drinking water(model and poly I:C groups) ad libitum for 7 d. Poly I:C was administrated subcutaneously (20 μg/mouse) 2 h prior to DSS induction in mice of the poly I:C group. Severity of colitis was evaluated by disease activity index, body weight, colon length, histology and myeloperoxidase (MPO) activity, as well as the production of proinflammatory cytokines, including tumor necrosis factor-α(TNF-α), interleukin 17(IL-17) and interferon-γ (IFN-γ). Intestinal permeability was analyzed by the fluorescein isothiocyanate labeleddextran (FITC-D) method. Ultrastructural features of the colon tissue were observed under electron microscopy. Expressions of tight junction(TJ) proteins, including zo-1, occludin and claudin-1, were measured by immunohistochemistry/immunofluorescence, Western blot and real-time quantitative polymerase chain reaction(RT-qPCR).RESULTS DSS caused significant damage to the colon tissue in the model group. Administration of poly I:C dramatically protected against DSS-induced colitis, as demonstrated by less body weight loss, lower disease activity index score, longer colon length, colonic MPO activity, and improved macroscopic and histological scores. It also ameliorated DSS-induced ultrastructural changes of the colon epithelium, as observed under scanning electron microscopy, as well as FITC-D permeability. The m RNA and protein expressions of TJ protein, zo-1, occludin and claudin-1 were also found to be significantly enhanced in the poly I:C group, as determined by immunohistochemistry/immunofluorescence, Western blot and RT-q PCR. By contrast, poly I:C pretreatment markedly reversed the DSS-induced up-regulated expressions of the inflammatory cytokines TNF-α, IL-17 and IFN-γ.CONCLUSION Our study suggested that poly I:C may protect against DSS-induced colitis through maintaining integrity of the epithelial barrier and regulating innate immune responses, which may shed light on the therapeutic potential of poly I:C in human colitis.
基金supported by the National Natural Science Foundation of China,No.31471044a grant from the Ministry of Science and Technology of China,No.2015AA020918
文摘Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system.Therefore,based on the regenerative capacity of stem cells,transplantation therapies of various stem cells have been tested in basic research and preclinical trials,and some have shown great prospects.This manuscript overviews the cellular and molecular characteristics of embryonic stem cells,induced pluripotent stem cells,neural stem cells,retinal stem/progenitor cells,mesenchymal stem/stromal cells,and their derivatives in vivo and in vitro as sources for regenerative therapy.These cells have all been considered as candidates to treat several major neurological disorders and diseases,owing to their self-renewal capacity,multi-directional differentiation,neurotrophic properties,and immune modulation effects.We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases,including Parkinson＇s disease,Alzheimer＇s disease,and age-related macular degeneration,as well as traumatic brain injury and glioblastoma.In spite of a few unsuccessful cases,risks of tumorigenicity,and ethical concerns,most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease.In summary,these emerging findings in regenerative medicine are likely to contribute to breakthroughs in the treatment of neurological disorders.Thus,stem cells are a promising candidate for the treatment of nervous system diseases.
基金supported by the State Foundation for High-tech Project"863"from the Ministry of Science and Technology,China (No.2001AA624100)grant from National Natural Science Foundation of China (No.20772155).
文摘A new triterpene glycoside, leucospilotaside C, along with two known saponin, was isolated from sea cucumber Holothuria leucospilota collected from the South China Sea, and its structure was elucidated as 3-0-{4′-O-sodiumsulfate-β′-D-xylopyranosyl}- holosta-22,25-epoxy-9-ene-3β,12α,17α-triol （1） by extensive spectroscopic analysis and chemical methods. The glycosides have the same triterpene aglycone, but differ in the oligosaccharide moieties.
基金the National Science Foundation of China,No.30800333
文摘BACKGROUND： Central sensitization, a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation, is an important mechanism underlying hyperalgesia and neuropathic pain. Participation of the glutamate-glutamine cycle in central sensitization of the spinal cord remains poorly understood. OBJECTIVE： To determine whether the astrocyte-neuronal glutamate-glutamine cycle is involved in formalin-induced central sensitization in the spinal cord. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Orthopedics, Second Hospital, Lanzhou University, China from September 2007 to August 2008. MATERIALS： Methionine sulfoximine （MSO, 0.1 mmol/L）, glutamine （0.25 mmol/L）, and formalin were used for this study. METHODS： A total of 43 male, Sprague Dawley rats, aged 4 months, were randomly assigned to a sham operation group （n = 6） and a model group （n = 37）. Rats in the model group received intrathecal infusion in the spinal cord. 7 days later, 37 model rats were randomly divided into PBS, MSO, glutamine, MSO ＋ glutamine and formalin subcutaneous injection alone groups. The PBS, MSO, glutamine, MSO ＋ glutamine groups were respectively intrathecally injected with PBS, MSO, glutamine, MSO ＋ glutamine （50 μL each）, and then infused with 10 μL of saline. Rats from the sham operation group were not subjected to intrathecal infusion in the spinal cord. At 15 minutes after intrathecal injection, a rat model of formalin-induced inflammatory pain was established by subcutaneous injection of 5% formalin （50 μL） in the left hindpaw. MAIN OUTCOME MEASURES： Changes in spontaneous nociceptive behavior （licking/biting or flinching） were observed following formalin injection into the rat hindpaw. RESULTS： Compared with the PBS group, duration of licking/biting was significantly shortened, and flinching frequency was significantly diminished in the MSO group （P 〈 0.05）. Compared with the MSO group, duration of licking/biting was significantly prolonged, and flinching frequency was significantly increased in the MSO ＋ glutamine group （P 〈 0.05）. There was no significant difference in inflammatory pain behaviors among the sham operation, PBS, glutamine, MSO ＋ glutamine, and formalin subcutaneous injection alone groups （P 〉 0.05）. CONCLUSION： The astrocyte-neuronal glutamate-glutamine cycle in the spinal cord was shown to be involved in central sensitization induced by formalin subcutaneous injection into the hindpaw.
基金supported by the mega-projects of national science research for the 11th Five-Year Plan (2008ZX10001-003)the Fogarty International Center, National Institutes of Health Office of the Director, Office of AIDS Research, National Cancer Institute,National Eye Institute,National Heart,Blood,and Lung Institute,National Institute of Dental & Craniofacial Research,National Institute On Drug Abuse,National Institute of Mental Health,National Institute of Allergy and Infectious Diseases Health,Office of Women’s Health Research, National Institute of Child Health and Human Development,through the International Clinical Research Fellows Program at Vanderbilt (R24 TW007988)
文摘Objective to explore dynamic characteristics of the HIV mother to child transmission （MTCT） epidemic in China.Methods A deterministic dynamic transmission model was used to determine the effect of key parameters on the likely long-term trends of the HIV MTCT epidemic in China.Matlab 7.0 was used to develop the model.Results The number of the susceptibles （S）,the transmission rate （β）,and the screening proportion （α） of HIV positive pregnant women have the greatest impact on the HIV MTCT epidemic in China.The growth of the MTCT epidemic in China could not be controlled only by decreasing the MTCT transmission rate.The prevalence of HIV positive women should be reduced and more pregnant women should be tested for HIV.Conclusion Prevention of MTCT （PMTCT） should focus not only on the reduction of HIV transmission rates and incidences of HIV among women but also on the increase of HIV testing for pregnant women.The most cost-effective PMTCT means for China should be investigated in future studies.
基金This work was financially supported by the National Natural Science Foundation of China(No.51704208).
文摘The flotation kinetics of different size fractions of conventional and nanobubble(NB) flotation were compared to investigate the effect of NBs on the flotation performance of various coal particle sizes. Six flotation kinetics models were selected to fit the flotation data, and NBs were observed on a hydrophobic surface under hydrodynamic cavitation by atomic force microscope scanning. Flotation results indicated that the best flotation performance of size fraction at-0.125+0.074 mm can be obtained either in conventional or NB flotation. NBs increase the combustible recovery of almost all the size fractions, but they increase the product ash content of-0.25+0.074 mm and reduce the product ash content of-0.045 mm at the same time. The first-order models can be used to fit the flotation data in conventional and NB flotation, and the classical first-order model is the most suitable one. NBs considerably enhance flotation rate on coarse size fraction(-0.5+0.25 mm) but decrease the flotation rate of the medium size(-0.25+0.074 mm). The improvement of flotation speed on fine coal particles(-0.074 mm) is probably the reason for the improved performance of raw sample flotation.
文摘BACKGROUND： Studies have shown that cell death can activate proliferation of endogenous neural stem cells and promote newly generated cells to migrate to a lesion site. OBJECTIVE： To observe regeneration and differentiation of neural cells following spinal cord injury in adult rats and to quantitatively analyze the newly differentiated cells. DESIGN, TIME AND SETTING： A cell biology experiment was performed at the Institute of Orthopedics and Medical Experimental Center, Lanzhou University, between August 2005 and October 2007. MATERIALS： Fifty adult, Wistar rats of both sexes; 5-bromodeoxyuridine （BrdU, Sigma, USA）; antibodies against neuron-specific enolase, glial fibrillary acidic protein, and myelin basic protein （Chemicon, USA）. METHODS： Twenty-five rats were assigned to the spinal cord injury group and received a spinal cord contusion injury. Materials were obtained at day 1, 3, 7, 15, and 29 after injury, with 5 rats for each time point. Twenty-five rats were sham-treated by removing the lamina of the vertebral arch without performing a contusion. MAIN OUTCOME MEASURES： The phenotype of BrdU-labeled cells, i.e., expression and distribution of surface markers for neurons （neuron-specific enolase）, astrocytes （glial fibrillary acidic protein）, and oligodendrocytes （myelin basic protein）, were identified with immunofluorescence double-labeling. Confocal microscopy was used to detect double-labeled cells by immunofluorescence. Quantitative analysis of newly generated cells was performed with stereological counting methods. RESULTS： There was significant cell production and differentiation after adult rat spinal cord injury. The quantity of newly-generated BrdU-labeled cells in the spinal cord lesion was 75-fold greater than in the corresponding area of control animals. Endogenous neural precursor cells differentiated into astrocytes and oligodendrocytes, however spontaneous neuronal differentiation was not detected. Between 7 and 29 d after spinal cord injury, newly generated cells expressed increasingly more mature oligodendrocyte and astrocyte markers. CONCLUSION： Spinal cord injury is a direct inducer of regeneration and differentiation of neural cells. Endogenous neural precursor cells can differentiate into astrocytes and oligodendrocytes following adult rat spinal cord injury.
基金This work was supported by the Provincial Natural Science Foundation of Hunan(No.04JJ6033) the Research Foundation of Hunan Education Bureau (No.03C066).
文摘A sliding mode variable structure control （SMVSC） based on a coordinating optimization algorithm has been developed. Steady state error and control switching frequency are used to constitute the system performance indexes in the coordinating optimization, while the tuning rate of boundary layer width （BLW） is employed as the optimization parameter. Based on the mathematical relationship between the BLW and steady-state error, an optimized BLW tuning rate is added to the nonlinear control term of SMVSC. Simulation experiment results applied to the positioning control of an electro-hydraulic servo system show the comprehensive superiority in dynamical and static state performance by using the proposed controller is better than that by using SMVSC without optimized BLW tuning rate. This succeeds in coordinately considering both chattering reduction and high-precision control realization in SMVSC.
基金This research was funded by The National Key Research and Development Program of China(Project No.2017YFD0600401).
文摘Optimization of in vitro adventitious root induction contributes to the development of a large-scale production system of hybrid clone seedlings of larch(Larix spp.).We used orthogonal testing to investigate the factors that affect the rooting of hybrid larch shoots-activated carbon,vitamin B1,sucrose,glycine,glutamic acid(Glu),cysteine,pH,and induction time in the dark and indole-3-butyric acid(IBA).Variance analysis showed that the effects of sucrose concentration on rooting rate,survival rate,and average root number,pH on the average number of roots;and Glu on survival rate were all significant(p<0.05)when compared to the mock treatments.Among all of the 45 treatments,the highest rooting rate was 90%,the highest survival rate was 100%,and the highest average root number was 11.8.The theoretically optimal procedure of in vitro root induction of hybrid larch shoots is shoot induction on L9 modified medium(pH 6.7)containing 2 mg.L^(-1)naphthalene acetic acid,0.25 mg.L^(-1)IBA,1/3 macroelements,7.5 g.L^(-1)sucrose,and 5 mg.L^(-1)Glu for 8 days,and then root induction on L9 modified medium without auxin.
文摘At present,there are a large number of informal landfills to be treated all over the country. Under the condition of limited treatment funds,it is necessary to prioritize the treatment of informal landfills. In this paper,the pollution risk of waste dump,surrounding soil,groundwater and surface water is analyzed,and a set of comprehensive risk assessment method system of informal landfill is established,which could provide reference for decision making department deciding landfill disposal.
基金supported by the National Natural Science Foundation of China (81100912)the Science Foundation of Xinxiang Medical University, China (CL and ZD 2009-63)the Science and Technology Project of Henan Province, China (092102310098)
文摘Progesterone is an efficient candidate for treating stroke and traumatic brain damage. The current study was designed to investigate the effects of pro gesterone on glucose transporter proteins （GLUT1 and GLUT3） during hypoxicischemic injury in a neo natal rat model. We demonstrated strong staining for GLUT1 in the walls of blood vessels and GLUT3 im munoreactivity in hippocampal neurons after hypoxia ischemia. Hypoxiaischemia elevated GLUT1 and GLUT3 at both the mRNA and protein levels in the hippocampus, and pretreatment with progesterone （8 mg/kg） further enhanced their accumulation until 24 h after hypoxicischemic injury. These results showed that progesterone treatment induced the accumula tion of both GLUT1 and GLUT3 transporters, and an energycompensation mechanism may be involved in the neuroprotective effect of progesterone during hy poxicischemic injury after cerebral ischemic attacks.
基金the National Natural Science Foundation of China(31671088 and 31730041)the Natural Science Foundation of Shaanxi Province,China(2017ZDJC-01)。
文摘Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.
基金supported by the grants from the Natural Science Foundation of China (Nos.30770693 and 30830067)the Ministry of Science and Technology of China (No. 2009CB521706)
文摘The retina is one of the most essential elements of vision pathway in vertebrate. The dysplasia of retina cause congenital blindness or vision disability in individuals, and the misbalance in adult retinal vascular homeostasis leads to neo adults, such as diabetic retinopathy or age-related macular degeneration. Many developmental signaling pathways are involved in the process of retinal development and vascular homeostasis. Among them, Notch signaling pathway has long been studied, and Notch signaling-interfered mouse models show both neural retina dysplasia and vascular abnormality. In this review, we discuss the roles of Notch signaling in the maintenance of retinal progenitor cells, specification of retinal neurons and glial cells, and the sustaining of retina vascular homeostasis, especially from the aspects of conditional knockout mouse models. The potential of Notch signal manipulation may provide a powerful cell fate- and neovascularization-controUing tool that could have important applications in treatment of retinal diseases.
基金the National Natural Science Foundation of China(Grant Nos.81530018,31371474,81370811,31570878 and 81300315).
文摘Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms remain unclear.In this study,we genetically targeted Notch signaling by disrupting the transcription factor recombination signal binding protein-JK(RBP-J),to reveal its role in regulation of macrophages during the unilateral ureteral obstruction(UUO)-induced murine renal fibrosis.Myeloid-specific disruption of RBP-J attenuated renal fibrosis with reduced extracellular matrix deposition and myofibroblast activation,as well as attenuated epithelial-mesenchymal transition,likely owing to the reduced expression of TGF-β.Mean while,RBP-J deletion significantly hampered macrophage infiltration and activation in fibrotic kidney,although their proliferation appeared unaltered.By using macrophage clearance experiment,we found that kidney resident macrophages made negligible contribution,but bone marrow(BM)-derived macrophages played a major role in renal fibrogenesis.Further mechanistic analyses showed that Notch blockade reduced monocyte emigration from BM by down-regulating CCR2 expression.Finally,we found that myeloid-specific Notch activation aggravated renal fibrosis,which was mediated by CCR2^+macrophages infiltration.In summary,our data have unveiled that myeloid-specific targeting of Notch could ameliorate renal fibrosis by regulating BM-derived macrophages recruitment and activation,providing a novel strategy for intervention of this disease.
