Traumatic injury or inflammatory irritation of the peripheral nervous system often leads to persistent pathophysiological pain states.It has been well-documented that,after peripheral nerve injury or inflammation,func...Traumatic injury or inflammatory irritation of the peripheral nervous system often leads to persistent pathophysiological pain states.It has been well-documented that,after peripheral nerve injury or inflammation,functional and anatomical alterations sweep over the entire peripheral nervous system including the peripheral nerve endings,the injured or inflamed afferent fibers,the dorsal root ganglion(DRG),and the central afferent terminals in the spinal cord.Among all the changes,ectopic discharge or spontaneous activity of primary sensory neurons is of great clinical interest,as such discharges doubtless contribute to the develop-ment of pathological pain states such as neuropathic pain.Two key sources of abnormal spontaneous activity have been identified following peripheral nerve injury:the injured afferent fibers(neuroma) leading to the DRG,and the DRG somata.The purpose of this review is to provide a global account of the abnormal spontaneous activity in various animal models of pain.Particular attention is focused on the consequence of peripheral nerve injury and localized inflammation.Further,mechanisms involved in the generation of spontaneous activity are also reviewed;evidence of spontaneous activity in contributing to abnormal sympathetic sprouting in the axotomized DRG and to the initiation of neuropathic pain based on new findings from our research group are discussed.An improved understanding of the causes of spontaneous activity and the origins of neuropathic pain should facilitate the development of novel strategies for effective treatment of pathological pain.展开更多
Objective To test whether in the absence of actin, actin-binding proteins such as caldesmon, calponin, and tropomyosin interact with the myosin of unphosphorylation, Ca 2+ -dependent phosphorylation (CDP), and Ca 2+ -...Objective To test whether in the absence of actin, actin-binding proteins such as caldesmon, calponin, and tropomyosin interact with the myosin of unphosphorylation, Ca 2+ -dependent phosphorylation (CDP), and Ca 2+ -independent phosphorylati-on (CIP) and stimulate myosin Mg 2+ -ATPase activities. Methods Mg 2+ -ATPase activities were measured to evaluate the effects of caldesmon, calponin, and tropomyosin on the myosin in unphosphorylation, CDP by myosin light chain kinase (MLCK), and CIP by MLCK. Results (1) At different incubation-time, i.e., 5, 10, 20, 40, and 60 minutes, the highest Mg 2+ -ATPase activity was ob-served when myosin was in the state of CDP, the medium was CIP of myosin, and the lowest was the unphosphorylated myosin. (2) In the absence of caldesmon, calponin, and tropomyosin, the Mg 2+ -ATPase activities from high to low were in the following order: CDP, CIP, and unphosphorylated myosin. However, in the presence of caldesmon, calponin, and tropo-myosin, the order of relative value of Mg 2+ -ATPase activities from high to low was unphosphorylated, CIP, and CDP of myosin respectively compared to the corresponding controls. Conclusions The results propose that caldesmon, calponin, and tropomyosin are capable of stimulating Mg 2+ -ATPase activity of smooth muscle myosin in Ca 2+ -independent manner, since Ca 2+ is not obligating for the stimulating effects of the three proteins. The common characteristic of the three proteins is that when myosin activities are low, their activations are relatively strong and this property might be involved in smooth muscle tension keeping.展开更多
Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-d...Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-dependent （kinetic） procedure and the concentration dependent （isotherm） procedure. Results indicate that the adsorption process is related to the kind of the studied compound. The equilibrium data are well suited to a Freundlich isotherm in the case of both investigated compounds. Adsorption kinetics of chlorpropham and 3-chloroaniline on acid-treated halloysite was successfully described by pseudo-second order kinetic model and the model of Weber and Morris. From the present study, we suggest that the adsorption of chlorpropham and 3-chloroaniline on the modified halloysite is a rather complex process involving two steps： external mass transfer and intra-particle diffusion.展开更多
Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms un- expected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwin...Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms un- expected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwing coloration across Eu- rope. Previous studies indicate that yellow males are better defended from predators, while white males have a positively frequency-dependent mating advantage. However, the potential frequency-dependent behavioural differences in flight between the morphs, as well as the role of male-male interactions in inducing flying activity, have not been previously considered. We ran an outdoor cage experiment where proportions of both male morphs were manipulated to test whether flying activity was frequency- dependent and differed between morphs. The white morph was significantly more active than the yellow one across all treatments, and sustained activity for longer. Overall activity for both morphs was considerably lower in the yellow-biased environment, suggesting that higher proportions of yellow males in a population may lead to overall reduced flying activity. The activity of the yellow morph also followed a steeper, narrower curve than that of the white morph during peak female calling activity. We sug- gest that white males, with their presumably less costly defences, have more resources to invest in flight for predator escape and finding mates. Yellow males, which are better protected but less sexually selected, may instead compensate their lower flight ac- tivity by ＇flying smart＇ during the peak female-calling periods. Thus, both morphs may be able to behaviourally balance the trade-off between warning signal selection and sexual selection. Our results emphasize the greater need to investigate animal behaviour and colour polymorphisms in natural or semi-natural environments [Current Zoology 61 （4）： 765-772, 2015].展开更多
文摘Traumatic injury or inflammatory irritation of the peripheral nervous system often leads to persistent pathophysiological pain states.It has been well-documented that,after peripheral nerve injury or inflammation,functional and anatomical alterations sweep over the entire peripheral nervous system including the peripheral nerve endings,the injured or inflamed afferent fibers,the dorsal root ganglion(DRG),and the central afferent terminals in the spinal cord.Among all the changes,ectopic discharge or spontaneous activity of primary sensory neurons is of great clinical interest,as such discharges doubtless contribute to the develop-ment of pathological pain states such as neuropathic pain.Two key sources of abnormal spontaneous activity have been identified following peripheral nerve injury:the injured afferent fibers(neuroma) leading to the DRG,and the DRG somata.The purpose of this review is to provide a global account of the abnormal spontaneous activity in various animal models of pain.Particular attention is focused on the consequence of peripheral nerve injury and localized inflammation.Further,mechanisms involved in the generation of spontaneous activity are also reviewed;evidence of spontaneous activity in contributing to abnormal sympathetic sprouting in the axotomized DRG and to the initiation of neuropathic pain based on new findings from our research group are discussed.An improved understanding of the causes of spontaneous activity and the origins of neuropathic pain should facilitate the development of novel strategies for effective treatment of pathological pain.
基金Supported by the National Natural Science Foundation of China ( 30070203).
文摘Objective To test whether in the absence of actin, actin-binding proteins such as caldesmon, calponin, and tropomyosin interact with the myosin of unphosphorylation, Ca 2+ -dependent phosphorylation (CDP), and Ca 2+ -independent phosphorylati-on (CIP) and stimulate myosin Mg 2+ -ATPase activities. Methods Mg 2+ -ATPase activities were measured to evaluate the effects of caldesmon, calponin, and tropomyosin on the myosin in unphosphorylation, CDP by myosin light chain kinase (MLCK), and CIP by MLCK. Results (1) At different incubation-time, i.e., 5, 10, 20, 40, and 60 minutes, the highest Mg 2+ -ATPase activity was ob-served when myosin was in the state of CDP, the medium was CIP of myosin, and the lowest was the unphosphorylated myosin. (2) In the absence of caldesmon, calponin, and tropomyosin, the Mg 2+ -ATPase activities from high to low were in the following order: CDP, CIP, and unphosphorylated myosin. However, in the presence of caldesmon, calponin, and tropo-myosin, the order of relative value of Mg 2+ -ATPase activities from high to low was unphosphorylated, CIP, and CDP of myosin respectively compared to the corresponding controls. Conclusions The results propose that caldesmon, calponin, and tropomyosin are capable of stimulating Mg 2+ -ATPase activity of smooth muscle myosin in Ca 2+ -independent manner, since Ca 2+ is not obligating for the stimulating effects of the three proteins. The common characteristic of the three proteins is that when myosin activities are low, their activations are relatively strong and this property might be involved in smooth muscle tension keeping.
文摘Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-dependent （kinetic） procedure and the concentration dependent （isotherm） procedure. Results indicate that the adsorption process is related to the kind of the studied compound. The equilibrium data are well suited to a Freundlich isotherm in the case of both investigated compounds. Adsorption kinetics of chlorpropham and 3-chloroaniline on acid-treated halloysite was successfully described by pseudo-second order kinetic model and the model of Weber and Morris. From the present study, we suggest that the adsorption of chlorpropham and 3-chloroaniline on the modified halloysite is a rather complex process involving two steps： external mass transfer and intra-particle diffusion.
文摘Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms un- expected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwing coloration across Eu- rope. Previous studies indicate that yellow males are better defended from predators, while white males have a positively frequency-dependent mating advantage. However, the potential frequency-dependent behavioural differences in flight between the morphs, as well as the role of male-male interactions in inducing flying activity, have not been previously considered. We ran an outdoor cage experiment where proportions of both male morphs were manipulated to test whether flying activity was frequency- dependent and differed between morphs. The white morph was significantly more active than the yellow one across all treatments, and sustained activity for longer. Overall activity for both morphs was considerably lower in the yellow-biased environment, suggesting that higher proportions of yellow males in a population may lead to overall reduced flying activity. The activity of the yellow morph also followed a steeper, narrower curve than that of the white morph during peak female calling activity. We sug- gest that white males, with their presumably less costly defences, have more resources to invest in flight for predator escape and finding mates. Yellow males, which are better protected but less sexually selected, may instead compensate their lower flight ac- tivity by ＇flying smart＇ during the peak female-calling periods. Thus, both morphs may be able to behaviourally balance the trade-off between warning signal selection and sexual selection. Our results emphasize the greater need to investigate animal behaviour and colour polymorphisms in natural or semi-natural environments [Current Zoology 61 （4）： 765-772, 2015].
