Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism...Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine （20 and 40 mM） and irradiated them with 50 mW/cm^2 microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation.展开更多
Peripheral nerve injury(PNI)is common and,unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury.Peripheral myelinating glia,Schwann cell...Peripheral nerve injury(PNI)is common and,unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury.Peripheral myelinating glia,Schwann cells(SCs),interact with various cells in and around the injury site and are important for debris elimination,repair,and nerve regeneration.Following PNI,Wallerian degeneration of the distal stump is rapidly initiated by degeneration of damaged axons followed by morphologic changes in SCs and the recruitment of circulating macrophages.Interaction with fibroblasts from the injured nerve microenvironment also plays a role in nerve repair.The replication and migration of injury-induced dedifferentiated SCs are also important in repairing the nerve.In particular,SC migration stimulates axonal regeneration and subsequent myelination of regenerated nerve fibers.This mobility increases SC interactions with other cells in the nerve and the exogenous environment,which influence SC behavior post-injury.Following PNI,SCs directly and indirectly interact with other SCs,fibroblasts,and macrophages.In addition,the inter-and intracellular mechanisms that underlie morphological and functional changes in SCs following PNI still require further research to explain known phenomena and less understood cell-specific roles in the repair of the injured peripheral nerve.This review provides a basic assessment of SC function post-PNI,as well as a more comprehensive evaluation of the literature concerning the SC interactions with macrophages and fibroblasts that can influence SC behavior and,ultimately,repair of the injured nerve.展开更多
After nerve-root avulsion injury of the brachial plexus, oxidative damage, inflammatory reaction, and glial scar formation can affect nerve regeneration and functional recovery. Melatonin(MT) has been shown to have go...After nerve-root avulsion injury of the brachial plexus, oxidative damage, inflammatory reaction, and glial scar formation can affect nerve regeneration and functional recovery. Melatonin(MT) has been shown to have good anti-inflammatory, antioxidant, and neuroprotective effects. Chondroitin sulfate ABC(ChABC) has been shown to metabolize chondroitin sulfate proteoglycans and can reduce colloidal scar formation. However, the effect of any of these drugs alone in the recovery of nerve function after injury is not completely satisfactory. Therefore, this experiment aimed to explore the effect and mechanism of combined application of melatonin and chondroitin sulfate ABC on nerve regeneration and functional recovery after nerve-root avulsion of the brachial plexus. Fifty-two Sprague-Dawley rats were selected and their C5–7 nerve roots were avulsed. Then, the C6 nerve roots were replanted to construct the brachial plexus nerve-root avulsion model. After successful modeling, the injured rats were randomly divided into four groups. The first group(injury) did not receive any drug treatment, but was treated with a pure gel-sponge carrier nerve-root implantation and an ethanol-saline solution via intraperitoneal(i.p.) injection. The second group(melatonin) was treated with melatonin via i.p. injection. The third group(chondroitin sulfate ABC) was treated with chondroitin sulfate ABC through local administration. The fourth group(melatonin + chondroitin sulfate ABC) was treated with melatonin through i.p. injection and chondroitin sulfate ABC through local administration. The upper limb Terzis grooming test was used 2–6 weeks after injury to evaluate motor function. Inflammation and oxidative damage within 24 hours of injury were evaluated by spectrophotometry. Immunofluorescence and neuroelectrophysiology were used to evaluate glial scar, neuronal protection, and nerve regeneration. The results showed that the Terzis grooming-test scores of the three groups that received treatment were better than those of the injury only group. Additionally, these three groups showed lower levels of C5–7 intramedullary peroxidase and malondialdehyde. Further, glial scar tissue in the C6 spinal segment was smaller and the number of motor neurons was greater. The endplate area of the biceps muscle was larger and the structure was clear. The latency of the compound potential of the myocutaneous nerve-biceps muscle was shorter. All these indexes were even greater in the melatonin + chondroitin sulfate ABC group than in the melatonin only or chondroitin sulfate ABC only groups. Thus, the results showed that melatonin combined with chondroitin sulfate ABC can promote nerve regeneration after nerve-root avulsion injury of the brachial plexus, which may be achieved by reducing oxidative damage and inflammatory reaction in the injury area and inhibiting glial scar formation.展开更多
BACKGROUND Trigger finger at the wrist,which occurs with finger movement,is an uncommon presentation.Few reports describing cases of trigger finger at the wrist have been published.Thus,we present a case of an intramu...BACKGROUND Trigger finger at the wrist,which occurs with finger movement,is an uncommon presentation.Few reports describing cases of trigger finger at the wrist have been published.Thus,we present a case of an intramuscular lipoma arising from an anomalous flexor digitorum muscle belly in a 48-year-old female patient causing painful finger triggering at the wrist and carpal tunnel syndrome(CTS).CASE SUMMARY A 48-year-old woman with complaints of a catching sensation during wrist motion and a progressive tingling sensation on the palmar aspect of the right hand for approximately 2 years was referred to our hospital.Triggering of the index to middle finger was evident with a palpable and audible clunk over the carpal tunnel during passive motion.Tinel’s sign was positive over the carpal tunnel of the right wrist with a positive Phalen’s test.Nerve conduction studies of the median nerve demonstrated a right CTS.Ultrasound examination revealed a 2.5 cm×2.0 cm subcutaneous hyperechoic mass with no obvious blood flow at the wrist of the right arm.Surgical excision of the tumor and muscle mass led to a resolution of the patient’s symptoms,and any triggering or discomfort disappeared.The patient has had no evidence of recurrence at more than 1 year of follow-up.CONCLUSION Triggering of the fingers at the wrist is rare. It must be noted that there are manypossible causes and types of triggering or clicking around the wrist. Accuratediagnosis is mandatory to avoid inaccurate treatment of patients with triggerwrist. During the diagnosis and treatment of CTS, attention should be paid to thevariation of tendon tissue in the carpal tunnel, to avoid only focusing on therelease of transverse carpal ligament and ignoring the removal of anomalousmuscle belly.展开更多
基金supported by the Integrated Drug Discovery Technology Platform of National Science and Technology Major Projects for "Major New Drugs Innovation and Development",No.2012ZX09J12201-005the National Natural Science Foundation of China,No.31071042,31200822a grant of Beijing Natural Science Foundation,No.5122033
文摘Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine （20 and 40 mM） and irradiated them with 50 mW/cm^2 microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation.
基金This work was also supported by the National Natural Science Foundation of China,No.81901365(to WRQ)Jilin Science and Technology Agency Funds in China,Nos.20180101118JC(to RL),20180520115JH(to BPC)and 20190103076JH(to WRQ).
文摘Peripheral nerve injury(PNI)is common and,unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury.Peripheral myelinating glia,Schwann cells(SCs),interact with various cells in and around the injury site and are important for debris elimination,repair,and nerve regeneration.Following PNI,Wallerian degeneration of the distal stump is rapidly initiated by degeneration of damaged axons followed by morphologic changes in SCs and the recruitment of circulating macrophages.Interaction with fibroblasts from the injured nerve microenvironment also plays a role in nerve repair.The replication and migration of injury-induced dedifferentiated SCs are also important in repairing the nerve.In particular,SC migration stimulates axonal regeneration and subsequent myelination of regenerated nerve fibers.This mobility increases SC interactions with other cells in the nerve and the exogenous environment,which influence SC behavior post-injury.Following PNI,SCs directly and indirectly interact with other SCs,fibroblasts,and macrophages.In addition,the inter-and intracellular mechanisms that underlie morphological and functional changes in SCs following PNI still require further research to explain known phenomena and less understood cell-specific roles in the repair of the injured peripheral nerve.This review provides a basic assessment of SC function post-PNI,as well as a more comprehensive evaluation of the literature concerning the SC interactions with macrophages and fibroblasts that can influence SC behavior and,ultimately,repair of the injured nerve.
文摘After nerve-root avulsion injury of the brachial plexus, oxidative damage, inflammatory reaction, and glial scar formation can affect nerve regeneration and functional recovery. Melatonin(MT) has been shown to have good anti-inflammatory, antioxidant, and neuroprotective effects. Chondroitin sulfate ABC(ChABC) has been shown to metabolize chondroitin sulfate proteoglycans and can reduce colloidal scar formation. However, the effect of any of these drugs alone in the recovery of nerve function after injury is not completely satisfactory. Therefore, this experiment aimed to explore the effect and mechanism of combined application of melatonin and chondroitin sulfate ABC on nerve regeneration and functional recovery after nerve-root avulsion of the brachial plexus. Fifty-two Sprague-Dawley rats were selected and their C5–7 nerve roots were avulsed. Then, the C6 nerve roots were replanted to construct the brachial plexus nerve-root avulsion model. After successful modeling, the injured rats were randomly divided into four groups. The first group(injury) did not receive any drug treatment, but was treated with a pure gel-sponge carrier nerve-root implantation and an ethanol-saline solution via intraperitoneal(i.p.) injection. The second group(melatonin) was treated with melatonin via i.p. injection. The third group(chondroitin sulfate ABC) was treated with chondroitin sulfate ABC through local administration. The fourth group(melatonin + chondroitin sulfate ABC) was treated with melatonin through i.p. injection and chondroitin sulfate ABC through local administration. The upper limb Terzis grooming test was used 2–6 weeks after injury to evaluate motor function. Inflammation and oxidative damage within 24 hours of injury were evaluated by spectrophotometry. Immunofluorescence and neuroelectrophysiology were used to evaluate glial scar, neuronal protection, and nerve regeneration. The results showed that the Terzis grooming-test scores of the three groups that received treatment were better than those of the injury only group. Additionally, these three groups showed lower levels of C5–7 intramedullary peroxidase and malondialdehyde. Further, glial scar tissue in the C6 spinal segment was smaller and the number of motor neurons was greater. The endplate area of the biceps muscle was larger and the structure was clear. The latency of the compound potential of the myocutaneous nerve-biceps muscle was shorter. All these indexes were even greater in the melatonin + chondroitin sulfate ABC group than in the melatonin only or chondroitin sulfate ABC only groups. Thus, the results showed that melatonin combined with chondroitin sulfate ABC can promote nerve regeneration after nerve-root avulsion injury of the brachial plexus, which may be achieved by reducing oxidative damage and inflammatory reaction in the injury area and inhibiting glial scar formation.
文摘BACKGROUND Trigger finger at the wrist,which occurs with finger movement,is an uncommon presentation.Few reports describing cases of trigger finger at the wrist have been published.Thus,we present a case of an intramuscular lipoma arising from an anomalous flexor digitorum muscle belly in a 48-year-old female patient causing painful finger triggering at the wrist and carpal tunnel syndrome(CTS).CASE SUMMARY A 48-year-old woman with complaints of a catching sensation during wrist motion and a progressive tingling sensation on the palmar aspect of the right hand for approximately 2 years was referred to our hospital.Triggering of the index to middle finger was evident with a palpable and audible clunk over the carpal tunnel during passive motion.Tinel’s sign was positive over the carpal tunnel of the right wrist with a positive Phalen’s test.Nerve conduction studies of the median nerve demonstrated a right CTS.Ultrasound examination revealed a 2.5 cm×2.0 cm subcutaneous hyperechoic mass with no obvious blood flow at the wrist of the right arm.Surgical excision of the tumor and muscle mass led to a resolution of the patient’s symptoms,and any triggering or discomfort disappeared.The patient has had no evidence of recurrence at more than 1 year of follow-up.CONCLUSION Triggering of the fingers at the wrist is rare. It must be noted that there are manypossible causes and types of triggering or clicking around the wrist. Accuratediagnosis is mandatory to avoid inaccurate treatment of patients with triggerwrist. During the diagnosis and treatment of CTS, attention should be paid to thevariation of tendon tissue in the carpal tunnel, to avoid only focusing on therelease of transverse carpal ligament and ignoring the removal of anomalousmuscle belly.
