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
Cisplatin chemotherapy has been used as the main treatment for different types of cancer.However,cisplatin chemotherapy-induced peripheral neuropathic pain(CIPNP)seriously affects the treatment process and quality of ...Cisplatin chemotherapy has been used as the main treatment for different types of cancer.However,cisplatin chemotherapy-induced peripheral neuropathic pain(CIPNP)seriously affects the treatment process and quality of life of patients.In addition,it impacts the underlying mechanism and prevention and treatment strategies,indicating that drug selection and efficacy evaluation need to be further investigated.Furthermore,an animal model that is more consistent with the pathological mechanism needs to be developed.In this study,we describe and discuss the methods of developing and detecting CIPNP models in rats and mice induced by cisplatin chemotherapy.The aim was to improve the modeling rate and develop animal models that are more consistent with the developmental pattern of the disease.In addition,the study provides ideal reference animal models for clinical research and drug discovery and development.展开更多
BACKGROUND Neck pain,a primary symptom of cervical spondylosis,affects patients'physical and mental health,reducing their quality of life.Pain and emotional state interact;however,their longitudinal interrelations...BACKGROUND Neck pain,a primary symptom of cervical spondylosis,affects patients'physical and mental health,reducing their quality of life.Pain and emotional state interact;however,their longitudinal interrelationship remains unclear.In this study,we applied a dual-trajectory model to assess how neck pain and emotional state evolve together over time and how clinical interventions,particularly acupuncture,influence these trajectories.AIM To investigate the longitudinal relationship between neck pain and emotional state in patients with cervical spondylosis.METHODS This prospective cohort study included 472 patients with cervical spondylosis from eight Chinese hospitals.Participants received acupuncture or medication and were followed up at baseline,and at 1,2,4,6,and 8 weeks.Neck pain and emotional distress were assessed using the Northwick Park Neck Pain Questionnaire(NPQ)and the affective subscale of the Short-Form McGill Pain Questionnaire(SF-MPQ),respectively.Group-based trajectory models and dual trajectory analysis were used to identify and correlate pain-emotion trajectories.Multivariate logistic regression identified predictors of group membership.RESULTS Three trajectory groups were identified for NPQ and SF-MPQ scores(low,medium,and high).Higher NPQ trajectory was associated with older age(OR=1.058,P<0.001)and was significantly reduced by acupuncture(OR=0.382,P<0.001).Similarly,acupuncture lowered the odds of high SF-MPQ trajectory membership(OR=0.336,P<0.001),while age increased it(OR=1.037,P<0.001).Dual-trajectory analysis revealed bidirectional associations:69.1%of patients with low NPQ had low SF-MPQ scores,and 42.6%of patients with high SF-MPQ also had high NPQ scores.Gender was a predictor for medium SF-MPQ trajectory(OR=1.629,P=0.094).Occupation and education levels differed significantly across the trajectory groups(P<0.05).CONCLUSION Over time,neck pain and emotional distress are closely associated in patients with cervical spondylosis.Acupuncture alleviates both outcomes significantly,while age is a risk factor.Integrated approaches to pain and emotional management are encouraged.展开更多
Chronic pancreatitis affects many individuals around the world,and the study of the underlying mechanisms leading to better treatment possibilities are important tasks.Therefore,animal models are needed to illustrate ...Chronic pancreatitis affects many individuals around the world,and the study of the underlying mechanisms leading to better treatment possibilities are important tasks.Therefore,animal models are needed to illustrate the basic study of pancreatitis.Recently,animal models of acute and chronic pancreatitis have been thoroughly reviewed,but few reviews address the important aspect on the translation of animal studies to human studies.It is well known that pancreatitis is associated with epigastric pain,but the understanding regarding to mechanisms and appropriate treatment of this pain is still unclear.Using animal models to study pancreatitis associated visceral pain is difficult,however,these types of models are a unique way to reveal the mechanisms behind pancreatitis associated visceral pain.In this review,the animal models of acute,chronic and un-common pancreatitis are briefly outlined and animal models related to pancreatitis associated visceral pain are also addressed.展开更多
As sciatica and low back pain are among the most common medical complaints, many studies have duplicated these conditions in animals. Chronic compression of the dorsal root ganglion （CCD） is one of these models. The...As sciatica and low back pain are among the most common medical complaints, many studies have duplicated these conditions in animals. Chronic compression of the dorsal root ganglion （CCD） is one of these models. The surgery is simple： after exposing the L4/L5 intervertebral foramina, stainless steel rods are implanted unilaterally, one rod for each vertebra, to chronically compress the lumbar dorsal root ganglion （DRG）. Then, CCD can be used to simulate the clinical conditions caused by stenosis, such as a laterally herniated disc or foraminal stenosis. As the intraforaminal implantation of a rod results in neuronal somal hyperexcitability and spontaneous action potentials associated with hyperalgesia, spontaneous pain, and mechanical allodynia, CCD provides an animal model that mimics radicular pain in humans. This review concerns the mechanisms of neuronal hyperexcitability, focusing on various patterns of spontaneous discharge including one possible pain signal for mechanical allodynia - evoked bursting. Also, new data regarding its significant property of maintaining peripheral input are also discussed. Investigations using this animal model will enhance our un-derstanding of the neural mechanisms for low back pain and sciatica. Furthermore, the peripheral location of the DRG fa-cilitates its use as a locus for controlling pain with minimal central effects, in the hope of ultimately uncovering analgesics that block neuropathic pain without influencing physiological pain.展开更多
BACKGROUND Transarterial chemoembolization(TACE)is the first-line treatment for patients with unresectable liver cancer;however,TACE is associated with postembolization pain.AIM To analyze the risk factors for acute a...BACKGROUND Transarterial chemoembolization(TACE)is the first-line treatment for patients with unresectable liver cancer;however,TACE is associated with postembolization pain.AIM To analyze the risk factors for acute abdominal pain after TACE and establish a predictive model for postembolization pain.METHODS From January 2018 to September 2018,all patients with liver cancer who underwent TACE at our hospital were included.General characteristics;clinical,imaging,and procedural data;and postembolization pain were analyzed.Postembolization pain was defined as acute moderate-to-severe abdominal pain within 24 h after TACE.Logistic regression and a classification and regression tree were used to develop a predictive model.Receiver operating characteristic curve analysis was used to examine the efficacy of the predictive model.RESULTS We analyzed 522 patients who underwent a total of 582 TACE procedures.Ninety-seven(16.70%)episodes of severe pain occurred.A predictive model built based on the dataset from classification and regression tree analysis identified known invasion of blood vessels as the strongest predictor of subsequent performance,followed by history of TACE,method of TACE,and history of abdominal pain after TACE.The area under the receiver operating characteristic curve was 0.736[95%confidence interval(CI):0.682-0.789],the sensitivity was 73.2%,the specificity was 65.6%,and the negative predictive value was 92.4%.Logistic regression produced similar results by identifying age[odds ratio(OR)=0.971;95%CI:0.951-0.992;P=0.007),history of TACE(OR=0.378;95%CI:0.189-0.757;P=0.007),history of abdominal pain after TACE(OR=6.288;95%CI:2.963-13.342;P<0.001),tumor size(OR=1.978;95%CI:1.175-3.330;P=0.01),multiple tumors(OR=2.164;95%CI:1.243-3.769;P=0.006),invasion of blood vessels(OR=1.756;95%CI:1.045-2.950;P=0.034),and TACE with drug-eluting beads(DEBTACE)(OR=2.05;95%CI:1.260-3.334;P=0.004)as independent predictive factors for postembolization pain.CONCLUSION Blood vessel invasion,TACE history,TACE with drug-eluting beads,and history of abdominal pain after TACE are predictors of acute moderate-to-severe pain.The predictive model may help medical staff to manage pain.展开更多
Pain is a subjective and complex phenomenon. Its complexity is related to its heterogeneity： multiple component processes, including sensation, affect, and cognition, contribute to pain experience and reporting. Thes...Pain is a subjective and complex phenomenon. Its complexity is related to its heterogeneity： multiple component processes, including sensation, affect, and cognition, contribute to pain experience and reporting. These components are likely to be encoded in distributed brain networks that interact to create pain experience and pain-related decision-making. Therefore, to understand pain, we must identify these networks and build models of these interactions that yield testable predictions about pain-related outcomes. We have developed several such models or ＇signatures＇ of pain, by （1） integrating activity across multiple systems, and （2） using pattern-recognition to identify processes related to pain experience. One model, the Neurologic Pain Signature, is sensitive and specific to pain in individuals, involves brain regions that receive nociceptive afferents, and shows little effect of expectation or self-regulation in tests to date. Another, the ＇Stimulus Intensity-Independent Pain Signature＇, explains substantial additional variation in trial-to-trial pain reports. It involves many brain regions that do not show increased activity in proportion to noxious stimulus intensity, includ- ing medial and lateral prefrontal cortex, nucleus accum- bens, and hippocampus. Responses in this system mediate expectancy and perceived control effects in several studies. Overall, this approach provides a pathway to understanding pain by identifying multiple systems that track different aspects of pain. Such componential models can be combined in unique ways on a subject-by-subject basis to explain an individual＇s pain experience.展开更多
Accumulating evidence has demonstrated that the sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 have a role in the modulation of pain transmission at the spinal level through chlorid...Accumulating evidence has demonstrated that the sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 have a role in the modulation of pain transmission at the spinal level through chloride regulation in the pain pathway and by effecting neuronal excitability and pain sensitization. The present study aimed to investigate the analgesic effect of the speciifc sodium-potassium-chloride co-transporter 1 inhibitor bumetanide, and the change in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain. Results showed that intrathecal bumetanide could decrease cumulative pain scores, and could increase thermal and mechanical pain thresholds in a rat model of incisional pain. Sodium-potassium-chloride co-transporter 1 expression in-creased in neurons from dorsal root ganglion and the deep laminae of the ipsilateral dorsal horn following incision. By contrast, potassium-chloride co-transporter 2 expression decreased in neurons of the deep laminae from the ipsilateral dorsal horn. These ifndings suggest that spinal sodium-potassium-chloride co-transporter 1 expression was up-regulated and spinal potassi-um-chloride co-transporter 2 expression was down-regulated following incision. Intrathecal bumetanide has analgesic effects on incisional pain through inhibition of sodium-potassi-um-chloride co-transporter 1.展开更多
Acute pain,provoked generally after the activation of peripheral nociceptors,is an adaptive sensory function that alerts the individual to avoid noxious stimuli.However,uncontrolled acute pain has a maladaptive role i...Acute pain,provoked generally after the activation of peripheral nociceptors,is an adaptive sensory function that alerts the individual to avoid noxious stimuli.However,uncontrolled acute pain has a maladaptive role in sensory activity leading to development of a chronic pain state which persists even after the damage is resolved,or in some cases,in the absence of an initial local acute injury.Huge numbers of people suffer from visceral pain at least once during their life span,leading to substantial health care costs.Although studies reporting on the mechanism of visceral pain are accumulating,it is still not precisely understood.Therefore,this review aims to elucidate the mechanism of visceral pain through an evaluation of different animal models and their application to develop novel therapeutic approaches for treating visceral pain.To assess the nociceptive responses in viscera,several visceral pain models such as inflammatory,traction,stress and genetic models utilizing different methods of measurement have been devised.Among them,the inflammatory and traction models are widely used for studying the visceral pain mechanism of different disease conditions and post-operative surgery in humans and animals.A hapten,2,4,6-trinitrobenzene sulfonic acid(TNBS),has been extensively used as an inflammatory agent to induce visceral pain.The traction model seems to cause a strong pain stimulation and autonomic reaction and could thus be the most appropriate model for studying the underlying visceral pain mechanism and for probing the therapeutic efficacies of various anesthetic and analgesics for the treatment of visceral pain and hyperalgesia.展开更多
BACKGROUND The incidence of cholecystolithiasis is on the rise.Use of information,motivation,and behavioral skills can play a positive role in promoting changes in individual health behaviors.However,reports on the ef...BACKGROUND The incidence of cholecystolithiasis is on the rise.Use of information,motivation,and behavioral skills can play a positive role in promoting changes in individual health behaviors.However,reports on the effects of information-motivationbehavioral(IMB)skills model based high-quality nursing as a perioperative nursing intervention for patients with gallstones are nonexistent.AIM To explore the application of IMB skills model based high-quality nursing in patients with gallstones.METHODS Two hundred and sixteen patients with cholecystolithiasis treated at our hospital from January 2022 to January 2023 were enrolled and divided into a control,highquality,and combined nursing groups,with 72 patients in each group.The control,high-quality,and combination groups received conventional,high-quality,and IMB skills model based perioperative nursing services,respectively.Differences in clinical indicators,stress levels,degree of pain,emotional state,and quality of life were observed,and complications and nursing satisfaction among the three groups were evaluated.RESULTS After nursing,the time to recovery of gastrointestinal function in the high-quality and combined nursing groups was significantly shorter than that of the control group,with the recovery of gastrointestinal function being the fastest in the combined nursing group(P<0.05).After nursing intervention,cortisol and norepinephrine levels in the high-quality and combined nursing groups were closer to normal than those of the control group 24 h after surgery,with the combined nursing group having the closest to normal levels(P<0.05).After 3 and 7 d of intervention,the patients’pain significantly improved,which was more prominent in the highquality and combination groups.Meanwhile,the pain score in the combination group was significantly lower than those of the control and high-quality nursing groups(P<0.05).After nursing intervention,the emotional states of all patients improved,and the scores of patients in the combination group were significantly lower than those of the control and high-quality nursing groups.The quality of life of patients in the high-quality and combined nursing groups significantly improved after nursing intervention compared to that of the control group,with the combined nursing group having the highest quality of life score.After intervention,the incidence of complications in the high-quality and combination groups was significantly lower than that of the control group(P<0.05),but the difference between the combination and high-quality nursing groups was not significant.Nursing satisfaction of patients in the high-quality and combination groups was significantly higher than that of the control group,with the nursing satisfaction being the highest in the combination group(P<0.05).CONCLUSION IMB skills model based nursing can improve surgical stress levels,degrees of pain,emotional state,quality of life,and nursing satisfaction of patients with gallstones and reduce the incidence of complications.展开更多
Purpose: To formulate and demonstrate methods for regression modeling of probabilities and dispersions for individual-patient longitudinal outcomes taking on discrete numeric values. Methods: Three alternatives for mo...Purpose: To formulate and demonstrate methods for regression modeling of probabilities and dispersions for individual-patient longitudinal outcomes taking on discrete numeric values. Methods: Three alternatives for modeling of outcome probabilities are considered. Multinomial probabilities are based on different intercepts and slopes for probabilities of different outcome values. Ordinal probabilities are based on different intercepts and the same slope for probabilities of different outcome values. Censored Poisson probabilities are based on the same intercept and slope for probabilities of different outcome values. Parameters are estimated with extended linear mixed modeling maximizing a likelihood-like function based on the multivariate normal density that accounts for within-patient correlation. Formulas are provided for gradient vectors and Hessian matrices for estimating model parameters. The likelihood-like function is also used to compute cross-validation scores for alternative models and to control an adaptive modeling process for identifying possibly nonlinear functional relationships in predictors for probabilities and dispersions. Example analyses are provided of daily pain ratings for a cancer patient over a period of 97 days. Results: The censored Poisson approach is preferable for modeling these data, and presumably other data sets of this kind, because it generates a competitive model with fewer parameters in less time than the other two approaches. The generated probabilities for this model are distinctly nonlinear in time while the dispersions are distinctly nonconstant over time, demonstrating the need for adaptive modeling of such data. The analyses also address the dependence of these daily pain ratings on time and the daily numbers of pain flares. Probabilities and dispersions change differently over time for different numbers of pain flares. Conclusions: Adaptive modeling of daily pain ratings for individual cancer patients is an effective way to identify nonlinear relationships in time as well as in other predictors such as the number of pain flares.展开更多
Background:The constructing PERMA model in psychological intervention was applied to patients with chronic cancer pain to provide data reference for reducing pain,fear of cancer recurrence,and improving the level of p...Background:The constructing PERMA model in psychological intervention was applied to patients with chronic cancer pain to provide data reference for reducing pain,fear of cancer recurrence,and improving the level of psychological capital.Aim:To explore the clinical effects of constructing PERMA model in psychological intervention for patients with chronic cancer pain.Methods:A total of 98 patients with chronic cancer pain admitted to our hospital from March 2021 to March 2023 were randomly divided into two groups,49 cases in each group.The control group received routine intervention,while the research group constructed PERMA model based on the routine intervention for psychological intervention.The pain severity,fear of cancer recurrence,psychological capital and quality of life before and after intervention were compared between the two groups.Results:After two months of intervention,the pain in the research group was milder than that in the control group(p<0.05).The scores and total scores of all dimensions of fear of cancer recurrence in the research group were lower than those in the control group(p<0.05).The scores and total scores of each dimension of psychological capital in the research group were higher than those in the control group(p<0.05).The scores of all dimensions of quality of life in the research group were higher than those in the control group(p<0.05).Conclusion:The PERMA model constructed in psychological interventions for patients with chronic cancer pain can assist analgesic medications to reduce pain and alleviate the fear of cancer recurrence,increase the level of psychological capital,and thus improve quality of life.展开更多
Software development is an important part of computer technology.only by ensuring the applicability and efficiency of the software can it really improve the efficiency of production and life,and truly inject new power...Software development is an important part of computer technology.only by ensuring the applicability and efficiency of the software can it really improve the efficiency of production and life,and truly inject new power into the economic benefits of the industry.As the theoretical basis of software development,the software development model directly determines the quality of software development.In this paper,starting with information technology as an important tool to improve modern management,it brings out the difficulties and pain points in the analysis of software development needs,and first puts forward the software development innovation model for building a composite core users.It takes core users with compound qualities and capabilities as the main line and guides the entire development process to enable both parties to communicate accurately and solve the pain points of demand communication,function optimization and project control to the greatest extent.Exploring application innovation in the software development model can promote innovation in the software industry.展开更多
Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects...Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects such as addiction,cardiovascular complications,and immunosuppression[2].In contrast,non-drug treatments like audio analgesia have demonstrated efficacy in pain relief without these side effects.Given the prevalence of chronic pain in the military population,it is essential to explore new treatments that effectively target its underlying mechanisms.One promising option is the Pannexin 1(Panx1)channel-forming protein.Panx1 is a large-pore ion channel in the plasma membrane of dorsal root ganglion(DRG)neurons that allows for the release of Adenosine triphosphate(ATP).Th is commentary elaborates on the fi ndings of Xing et al.[3],who investigated the role of Panx1 in peripheral pain sensitization following infl ammatory stimuli.We examine the role of Panx1 in chronic pain,critique Xing et al.’s[3]adjuvant selection and power analysis,and discuss the challenges of translating fi ndings from animal models to human conditions.展开更多
Chronic lower back pain(LBP)is the leading cause of disability worldwide.Due to its close relationship with intervertebral disc(IVD)degeneration(IVDD),research has historically focused more on understanding the mechan...Chronic lower back pain(LBP)is the leading cause of disability worldwide.Due to its close relationship with intervertebral disc(IVD)degeneration(IVDD),research has historically focused more on understanding the mechanism behind IVDD while clinical efforts prioritize pain management.More recently,there has been a shift toward understanding LBP as a distinct pathological entity.This review synthesizes current knowledge on discogenic LBP,combining known pathophysiology,molecular mechanisms,risk factors,diagnostic challenges,and available experimental models.IVDD is a complex,multifactorial process involving biochemical,mechanical,and inflammatory changes within the disc,leading to structural breakdown and potential discogenic pain.Key mechanisms include extracellular matrix degradation,upregulation of inflammatory mediators,immune cell infiltration,and aberrant nerve and vascular ingrowth.However,not all cases of IVDD result in LBP,highlighting the need for further investigation into the cellular,molecular,and biomechanical factors contributing to symptom development.Current diagnostic tools and experimental models for studying discogenic LBP remain limited,impeding the development of targeted treatments.Existing therapies primarily focus on symptom management rather than addressing underlying disease mechanisms.展开更多
Chronic pain and disability following acute orthopedic trauma are not only physical concerns but also deeply intertwined with psychological well-being.The recent retrospective cohort study by Yang et al,published,prov...Chronic pain and disability following acute orthopedic trauma are not only physical concerns but also deeply intertwined with psychological well-being.The recent retrospective cohort study by Yang et al,published,provides compelling evidence of significant associations between depression,anxiety,and postoperative recovery.These findings align with an expanding body of literature that confirms the need for orthopedic rehabilitation to adopt a biopsychosocial perspective.This letter contextualizes Yang et al’s study within current evidence,highlighting the roles of sleep disturbance,catastrophizing,stress,neurobiological mechanisms,and coping strategies in shaping recovery.It further emphasizes the importance of integrating nursing-led and multidisciplinary interventions to address both physical and psychological domains,ultimately promoting holistic recovery.展开更多
AIM:Irritable bowel syndrome(IBS)is a functional bowel disorder characterized by visceral hypersensitivity and altered bowel motility.There is increasing evidence suggesting the role of inflammation in the pathogenesi...AIM:Irritable bowel syndrome(IBS)is a functional bowel disorder characterized by visceral hypersensitivity and altered bowel motility.There is increasing evidence suggesting the role of inflammation in the pathogenesis of IBS,which addresses the possibility that formerly established rat model of colitis could be used as an IBS model after the inflammation subsided. METHODS:Colitis was induced by intracolonic instillation of 4% acetic acid in male Sprague-Dawley rats.The extent of inflammation was assessed by histological examination and myeloperoxidase(MPO)activity assay.After subsidence of colitis,the rats were subjected to rectal distension and restraint stress,then the abdominal withdrawal reflex and the number of stress-induced fecal output were measured, respectively. RESULTS:At 2 days post-induction of colitis,the colon showed characteristic inflammatory changes in histology and 8-fold increase in MPO activity.At 7 days post-induction of colitis,the histological features and MPO activity returned to normal.The rats at 7 days post-induction of colitis showed hypersensitive response to rectal distension without an accompaning change in rectal compliance,and defecated more stools than control animals when under stress.CONCLUSION: These results concur largely with the characteristic features of IBS, visceral hypersensitivity and altered defecation pattern in the absence of detectable disease, suggesting that this animal model is a methodologically convenient and useful model for studying a subset of IBS.展开更多
In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given ...In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given spatial temperature profile. Our model is distilled from sub-step components in the ADT CHEETEH-E model developed at the Institute for Defense Analyses. Our model has only two parameters: the activation temperature of nociceptors and the critical threshold on the activated volume. When the spatial temperature profile is measurable, the two parameters can be determined from test data. We connect this dose-response relation to a temperature evolution model for electromagnetic heating. The resulting composite model governs the process from the electromagnetic beam deposited on the skin to the binary outcome of subject’s reflex response. We carry out non-dimensionalization in the time evolution model. The temperature solution of the non-dimensional system is the product of the applied power density and a parameter-free function. The effects of physical parameters are contained in non-dimensional time and depth. Scaling the physical temperature distribution into a parameter-free function greatly simplifies the analytical solution, and helps to pinpoint the effects of beam spot area and applied power density. With this formulation, we study the theoretical behaviors of the system, including the time of reflex, effect of heat conduction, biological latency in observed reflex, energy consumption by the time of reflex, and the strategy of selecting test conditions in experiments for the purpose of inferring model parameters from test data.展开更多
Objective · Formalin is a classic and most widely used algogenic substance, but its itchy effect is not clear. The present study aims to explore the hypothesis that formalin may induce itch as well as pain. Metho...Objective · Formalin is a classic and most widely used algogenic substance, but its itchy effect is not clear. The present study aims to explore the hypothesis that formalin may induce itch as well as pain. Methods · Flinching, as well as licking and forelimb wiping of the site of injection were counted as pain responses, whereas biting and hind paw scratching of the cheek were counted as itchy responses. To discriminate formalin-induced sensations in rats, the irritant(saline as control) was injected, and then pain and itchy responses were recorded.Results · Intraplantar injection of formalin elicited biphasic behavior responses characterized as flinching, as well as biting or licking of the hind paw without significant gender differences. Following intradermal administration of formalin to the cheek, rats exhibited episodic forelimb wiping of the cheek, representative of pain. No gender difference was noticed for this type of behavior. In addition, episodes of hind paw scratches of the cheek, representative of pruritoceptive responses, also occurred. Interestingly, hind paw scratches appeared to be more pronounced in male than in female rats. Conclusion · Intradermal administration of formalin elicits pruritoceptive as well as nociceptive responses in rats.展开更多
A rat model of extra-vertebral foramen cervical nerve entrapment was established according to the following parameters： stimulation intensity 20 V; frequency 50 Hz; pulse width 200 μs; duration 333 ms/s for a total ...A rat model of extra-vertebral foramen cervical nerve entrapment was established according to the following parameters： stimulation intensity 20 V; frequency 50 Hz; pulse width 200 μs; duration 333 ms/s for a total of 8 hours. After the electrical stimulation, rats exhibited mild muscle fiber atrophy, mild inflammatory exudates, connective tissue local fibrosis and chondrocyte metaplasia. Mean muscle fiber cross-sectional area was reduced. The nerve myelin sheath continuity was partially demyelinated. The microstructure of nerve cells was disrupted and these symptoms worsened with prolongation of the stimulation. The shoulder, neck and upper extremity muscles on the tested side demonstrated positive sharp waves and fibrillations. The severity increased with continuation of the stimulation. High amplitude and polyphasic motor unit potentials gradually appeared. Similar findings were seen in the contralateral side, but at a less severe level.展开更多
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Liaoning Provincial Key Research and Development Program,Grant/Award Number:2024JH2/102500062China Health Promotion Foundation Spark Program,Grant/Award Number:XH-D001National Natural Science Foundation of China,Grant/Award Number:82104838。
文摘Cisplatin chemotherapy has been used as the main treatment for different types of cancer.However,cisplatin chemotherapy-induced peripheral neuropathic pain(CIPNP)seriously affects the treatment process and quality of life of patients.In addition,it impacts the underlying mechanism and prevention and treatment strategies,indicating that drug selection and efficacy evaluation need to be further investigated.Furthermore,an animal model that is more consistent with the pathological mechanism needs to be developed.In this study,we describe and discuss the methods of developing and detecting CIPNP models in rats and mice induced by cisplatin chemotherapy.The aim was to improve the modeling rate and develop animal models that are more consistent with the developmental pattern of the disease.In addition,the study provides ideal reference animal models for clinical research and drug discovery and development.
基金Supported by 2022 Chinese Medicine Scientific Research Project of Hebei Administration of Traditional Chinese Medicine,No.20221572025 Annual Scientific Research Project of Higher Education Institutions in Hebei Province,No.QN2025654.
文摘BACKGROUND Neck pain,a primary symptom of cervical spondylosis,affects patients'physical and mental health,reducing their quality of life.Pain and emotional state interact;however,their longitudinal interrelationship remains unclear.In this study,we applied a dual-trajectory model to assess how neck pain and emotional state evolve together over time and how clinical interventions,particularly acupuncture,influence these trajectories.AIM To investigate the longitudinal relationship between neck pain and emotional state in patients with cervical spondylosis.METHODS This prospective cohort study included 472 patients with cervical spondylosis from eight Chinese hospitals.Participants received acupuncture or medication and were followed up at baseline,and at 1,2,4,6,and 8 weeks.Neck pain and emotional distress were assessed using the Northwick Park Neck Pain Questionnaire(NPQ)and the affective subscale of the Short-Form McGill Pain Questionnaire(SF-MPQ),respectively.Group-based trajectory models and dual trajectory analysis were used to identify and correlate pain-emotion trajectories.Multivariate logistic regression identified predictors of group membership.RESULTS Three trajectory groups were identified for NPQ and SF-MPQ scores(low,medium,and high).Higher NPQ trajectory was associated with older age(OR=1.058,P<0.001)and was significantly reduced by acupuncture(OR=0.382,P<0.001).Similarly,acupuncture lowered the odds of high SF-MPQ trajectory membership(OR=0.336,P<0.001),while age increased it(OR=1.037,P<0.001).Dual-trajectory analysis revealed bidirectional associations:69.1%of patients with low NPQ had low SF-MPQ scores,and 42.6%of patients with high SF-MPQ also had high NPQ scores.Gender was a predictor for medium SF-MPQ trajectory(OR=1.629,P=0.094).Occupation and education levels differed significantly across the trajectory groups(P<0.05).CONCLUSION Over time,neck pain and emotional distress are closely associated in patients with cervical spondylosis.Acupuncture alleviates both outcomes significantly,while age is a risk factor.Integrated approaches to pain and emotional management are encouraged.
文摘Chronic pancreatitis affects many individuals around the world,and the study of the underlying mechanisms leading to better treatment possibilities are important tasks.Therefore,animal models are needed to illustrate the basic study of pancreatitis.Recently,animal models of acute and chronic pancreatitis have been thoroughly reviewed,but few reviews address the important aspect on the translation of animal studies to human studies.It is well known that pancreatitis is associated with epigastric pain,but the understanding regarding to mechanisms and appropriate treatment of this pain is still unclear.Using animal models to study pancreatitis associated visceral pain is difficult,however,these types of models are a unique way to reveal the mechanisms behind pancreatitis associated visceral pain.In this review,the animal models of acute,chronic and un-common pancreatitis are briefly outlined and animal models related to pancreatitis associated visceral pain are also addressed.
基金supported by the National Natural Science Foundation of China(30870829)
文摘As sciatica and low back pain are among the most common medical complaints, many studies have duplicated these conditions in animals. Chronic compression of the dorsal root ganglion （CCD） is one of these models. The surgery is simple： after exposing the L4/L5 intervertebral foramina, stainless steel rods are implanted unilaterally, one rod for each vertebra, to chronically compress the lumbar dorsal root ganglion （DRG）. Then, CCD can be used to simulate the clinical conditions caused by stenosis, such as a laterally herniated disc or foraminal stenosis. As the intraforaminal implantation of a rod results in neuronal somal hyperexcitability and spontaneous action potentials associated with hyperalgesia, spontaneous pain, and mechanical allodynia, CCD provides an animal model that mimics radicular pain in humans. This review concerns the mechanisms of neuronal hyperexcitability, focusing on various patterns of spontaneous discharge including one possible pain signal for mechanical allodynia - evoked bursting. Also, new data regarding its significant property of maintaining peripheral input are also discussed. Investigations using this animal model will enhance our un-derstanding of the neural mechanisms for low back pain and sciatica. Furthermore, the peripheral location of the DRG fa-cilitates its use as a locus for controlling pain with minimal central effects, in the hope of ultimately uncovering analgesics that block neuropathic pain without influencing physiological pain.
基金Supported by Medical Health Science and Technology Project of Zhejiang Provincial Health Commission,China,No.2020372769.
文摘BACKGROUND Transarterial chemoembolization(TACE)is the first-line treatment for patients with unresectable liver cancer;however,TACE is associated with postembolization pain.AIM To analyze the risk factors for acute abdominal pain after TACE and establish a predictive model for postembolization pain.METHODS From January 2018 to September 2018,all patients with liver cancer who underwent TACE at our hospital were included.General characteristics;clinical,imaging,and procedural data;and postembolization pain were analyzed.Postembolization pain was defined as acute moderate-to-severe abdominal pain within 24 h after TACE.Logistic regression and a classification and regression tree were used to develop a predictive model.Receiver operating characteristic curve analysis was used to examine the efficacy of the predictive model.RESULTS We analyzed 522 patients who underwent a total of 582 TACE procedures.Ninety-seven(16.70%)episodes of severe pain occurred.A predictive model built based on the dataset from classification and regression tree analysis identified known invasion of blood vessels as the strongest predictor of subsequent performance,followed by history of TACE,method of TACE,and history of abdominal pain after TACE.The area under the receiver operating characteristic curve was 0.736[95%confidence interval(CI):0.682-0.789],the sensitivity was 73.2%,the specificity was 65.6%,and the negative predictive value was 92.4%.Logistic regression produced similar results by identifying age[odds ratio(OR)=0.971;95%CI:0.951-0.992;P=0.007),history of TACE(OR=0.378;95%CI:0.189-0.757;P=0.007),history of abdominal pain after TACE(OR=6.288;95%CI:2.963-13.342;P<0.001),tumor size(OR=1.978;95%CI:1.175-3.330;P=0.01),multiple tumors(OR=2.164;95%CI:1.243-3.769;P=0.006),invasion of blood vessels(OR=1.756;95%CI:1.045-2.950;P=0.034),and TACE with drug-eluting beads(DEBTACE)(OR=2.05;95%CI:1.260-3.334;P=0.004)as independent predictive factors for postembolization pain.CONCLUSION Blood vessel invasion,TACE history,TACE with drug-eluting beads,and history of abdominal pain after TACE are predictors of acute moderate-to-severe pain.The predictive model may help medical staff to manage pain.
文摘Pain is a subjective and complex phenomenon. Its complexity is related to its heterogeneity： multiple component processes, including sensation, affect, and cognition, contribute to pain experience and reporting. These components are likely to be encoded in distributed brain networks that interact to create pain experience and pain-related decision-making. Therefore, to understand pain, we must identify these networks and build models of these interactions that yield testable predictions about pain-related outcomes. We have developed several such models or ＇signatures＇ of pain, by （1） integrating activity across multiple systems, and （2） using pattern-recognition to identify processes related to pain experience. One model, the Neurologic Pain Signature, is sensitive and specific to pain in individuals, involves brain regions that receive nociceptive afferents, and shows little effect of expectation or self-regulation in tests to date. Another, the ＇Stimulus Intensity-Independent Pain Signature＇, explains substantial additional variation in trial-to-trial pain reports. It involves many brain regions that do not show increased activity in proportion to noxious stimulus intensity, includ- ing medial and lateral prefrontal cortex, nucleus accum- bens, and hippocampus. Responses in this system mediate expectancy and perceived control effects in several studies. Overall, this approach provides a pathway to understanding pain by identifying multiple systems that track different aspects of pain. Such componential models can be combined in unique ways on a subject-by-subject basis to explain an individual＇s pain experience.
基金supported by a grant from Guangzhou Medical University,No.2008C24
文摘Accumulating evidence has demonstrated that the sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 have a role in the modulation of pain transmission at the spinal level through chloride regulation in the pain pathway and by effecting neuronal excitability and pain sensitization. The present study aimed to investigate the analgesic effect of the speciifc sodium-potassium-chloride co-transporter 1 inhibitor bumetanide, and the change in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain. Results showed that intrathecal bumetanide could decrease cumulative pain scores, and could increase thermal and mechanical pain thresholds in a rat model of incisional pain. Sodium-potassium-chloride co-transporter 1 expression in-creased in neurons from dorsal root ganglion and the deep laminae of the ipsilateral dorsal horn following incision. By contrast, potassium-chloride co-transporter 2 expression decreased in neurons of the deep laminae from the ipsilateral dorsal horn. These ifndings suggest that spinal sodium-potassium-chloride co-transporter 1 expression was up-regulated and spinal potassi-um-chloride co-transporter 2 expression was down-regulated following incision. Intrathecal bumetanide has analgesic effects on incisional pain through inhibition of sodium-potassi-um-chloride co-transporter 1.
文摘Acute pain,provoked generally after the activation of peripheral nociceptors,is an adaptive sensory function that alerts the individual to avoid noxious stimuli.However,uncontrolled acute pain has a maladaptive role in sensory activity leading to development of a chronic pain state which persists even after the damage is resolved,or in some cases,in the absence of an initial local acute injury.Huge numbers of people suffer from visceral pain at least once during their life span,leading to substantial health care costs.Although studies reporting on the mechanism of visceral pain are accumulating,it is still not precisely understood.Therefore,this review aims to elucidate the mechanism of visceral pain through an evaluation of different animal models and their application to develop novel therapeutic approaches for treating visceral pain.To assess the nociceptive responses in viscera,several visceral pain models such as inflammatory,traction,stress and genetic models utilizing different methods of measurement have been devised.Among them,the inflammatory and traction models are widely used for studying the visceral pain mechanism of different disease conditions and post-operative surgery in humans and animals.A hapten,2,4,6-trinitrobenzene sulfonic acid(TNBS),has been extensively used as an inflammatory agent to induce visceral pain.The traction model seems to cause a strong pain stimulation and autonomic reaction and could thus be the most appropriate model for studying the underlying visceral pain mechanism and for probing the therapeutic efficacies of various anesthetic and analgesics for the treatment of visceral pain and hyperalgesia.
文摘BACKGROUND The incidence of cholecystolithiasis is on the rise.Use of information,motivation,and behavioral skills can play a positive role in promoting changes in individual health behaviors.However,reports on the effects of information-motivationbehavioral(IMB)skills model based high-quality nursing as a perioperative nursing intervention for patients with gallstones are nonexistent.AIM To explore the application of IMB skills model based high-quality nursing in patients with gallstones.METHODS Two hundred and sixteen patients with cholecystolithiasis treated at our hospital from January 2022 to January 2023 were enrolled and divided into a control,highquality,and combined nursing groups,with 72 patients in each group.The control,high-quality,and combination groups received conventional,high-quality,and IMB skills model based perioperative nursing services,respectively.Differences in clinical indicators,stress levels,degree of pain,emotional state,and quality of life were observed,and complications and nursing satisfaction among the three groups were evaluated.RESULTS After nursing,the time to recovery of gastrointestinal function in the high-quality and combined nursing groups was significantly shorter than that of the control group,with the recovery of gastrointestinal function being the fastest in the combined nursing group(P<0.05).After nursing intervention,cortisol and norepinephrine levels in the high-quality and combined nursing groups were closer to normal than those of the control group 24 h after surgery,with the combined nursing group having the closest to normal levels(P<0.05).After 3 and 7 d of intervention,the patients’pain significantly improved,which was more prominent in the highquality and combination groups.Meanwhile,the pain score in the combination group was significantly lower than those of the control and high-quality nursing groups(P<0.05).After nursing intervention,the emotional states of all patients improved,and the scores of patients in the combination group were significantly lower than those of the control and high-quality nursing groups.The quality of life of patients in the high-quality and combined nursing groups significantly improved after nursing intervention compared to that of the control group,with the combined nursing group having the highest quality of life score.After intervention,the incidence of complications in the high-quality and combination groups was significantly lower than that of the control group(P<0.05),but the difference between the combination and high-quality nursing groups was not significant.Nursing satisfaction of patients in the high-quality and combination groups was significantly higher than that of the control group,with the nursing satisfaction being the highest in the combination group(P<0.05).CONCLUSION IMB skills model based nursing can improve surgical stress levels,degrees of pain,emotional state,quality of life,and nursing satisfaction of patients with gallstones and reduce the incidence of complications.
文摘Purpose: To formulate and demonstrate methods for regression modeling of probabilities and dispersions for individual-patient longitudinal outcomes taking on discrete numeric values. Methods: Three alternatives for modeling of outcome probabilities are considered. Multinomial probabilities are based on different intercepts and slopes for probabilities of different outcome values. Ordinal probabilities are based on different intercepts and the same slope for probabilities of different outcome values. Censored Poisson probabilities are based on the same intercept and slope for probabilities of different outcome values. Parameters are estimated with extended linear mixed modeling maximizing a likelihood-like function based on the multivariate normal density that accounts for within-patient correlation. Formulas are provided for gradient vectors and Hessian matrices for estimating model parameters. The likelihood-like function is also used to compute cross-validation scores for alternative models and to control an adaptive modeling process for identifying possibly nonlinear functional relationships in predictors for probabilities and dispersions. Example analyses are provided of daily pain ratings for a cancer patient over a period of 97 days. Results: The censored Poisson approach is preferable for modeling these data, and presumably other data sets of this kind, because it generates a competitive model with fewer parameters in less time than the other two approaches. The generated probabilities for this model are distinctly nonlinear in time while the dispersions are distinctly nonconstant over time, demonstrating the need for adaptive modeling of such data. The analyses also address the dependence of these daily pain ratings on time and the daily numbers of pain flares. Probabilities and dispersions change differently over time for different numbers of pain flares. Conclusions: Adaptive modeling of daily pain ratings for individual cancer patients is an effective way to identify nonlinear relationships in time as well as in other predictors such as the number of pain flares.
基金the Deanship of Research and Graduate Studies of King Khalid University for funding this work through grant number RGP1/194/45Research Project Funded by Nantong Municipal Health Commission(QNZ2023058).
文摘Background:The constructing PERMA model in psychological intervention was applied to patients with chronic cancer pain to provide data reference for reducing pain,fear of cancer recurrence,and improving the level of psychological capital.Aim:To explore the clinical effects of constructing PERMA model in psychological intervention for patients with chronic cancer pain.Methods:A total of 98 patients with chronic cancer pain admitted to our hospital from March 2021 to March 2023 were randomly divided into two groups,49 cases in each group.The control group received routine intervention,while the research group constructed PERMA model based on the routine intervention for psychological intervention.The pain severity,fear of cancer recurrence,psychological capital and quality of life before and after intervention were compared between the two groups.Results:After two months of intervention,the pain in the research group was milder than that in the control group(p<0.05).The scores and total scores of all dimensions of fear of cancer recurrence in the research group were lower than those in the control group(p<0.05).The scores and total scores of each dimension of psychological capital in the research group were higher than those in the control group(p<0.05).The scores of all dimensions of quality of life in the research group were higher than those in the control group(p<0.05).Conclusion:The PERMA model constructed in psychological interventions for patients with chronic cancer pain can assist analgesic medications to reduce pain and alleviate the fear of cancer recurrence,increase the level of psychological capital,and thus improve quality of life.
文摘Software development is an important part of computer technology.only by ensuring the applicability and efficiency of the software can it really improve the efficiency of production and life,and truly inject new power into the economic benefits of the industry.As the theoretical basis of software development,the software development model directly determines the quality of software development.In this paper,starting with information technology as an important tool to improve modern management,it brings out the difficulties and pain points in the analysis of software development needs,and first puts forward the software development innovation model for building a composite core users.It takes core users with compound qualities and capabilities as the main line and guides the entire development process to enable both parties to communicate accurately and solve the pain points of demand communication,function optimization and project control to the greatest extent.Exploring application innovation in the software development model can promote innovation in the software industry.
基金supported by the Office of Naval Research Grant(N00014-22-1-2184).
文摘Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects such as addiction,cardiovascular complications,and immunosuppression[2].In contrast,non-drug treatments like audio analgesia have demonstrated efficacy in pain relief without these side effects.Given the prevalence of chronic pain in the military population,it is essential to explore new treatments that effectively target its underlying mechanisms.One promising option is the Pannexin 1(Panx1)channel-forming protein.Panx1 is a large-pore ion channel in the plasma membrane of dorsal root ganglion(DRG)neurons that allows for the release of Adenosine triphosphate(ATP).Th is commentary elaborates on the fi ndings of Xing et al.[3],who investigated the role of Panx1 in peripheral pain sensitization following infl ammatory stimuli.We examine the role of Panx1 in chronic pain,critique Xing et al.’s[3]adjuvant selection and power analysis,and discuss the challenges of translating fi ndings from animal models to human conditions.
基金supported by the California Institute for Regenerative Medicine under EDUC4-12751(Giselle Kaneda)DISC2-14049(Dmitriy Sheyn)+1 种基金Additional support was provided by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award numbers R01AR066517(Debiao Li)R01AR082041(Dmitriy Sheyn).
文摘Chronic lower back pain(LBP)is the leading cause of disability worldwide.Due to its close relationship with intervertebral disc(IVD)degeneration(IVDD),research has historically focused more on understanding the mechanism behind IVDD while clinical efforts prioritize pain management.More recently,there has been a shift toward understanding LBP as a distinct pathological entity.This review synthesizes current knowledge on discogenic LBP,combining known pathophysiology,molecular mechanisms,risk factors,diagnostic challenges,and available experimental models.IVDD is a complex,multifactorial process involving biochemical,mechanical,and inflammatory changes within the disc,leading to structural breakdown and potential discogenic pain.Key mechanisms include extracellular matrix degradation,upregulation of inflammatory mediators,immune cell infiltration,and aberrant nerve and vascular ingrowth.However,not all cases of IVDD result in LBP,highlighting the need for further investigation into the cellular,molecular,and biomechanical factors contributing to symptom development.Current diagnostic tools and experimental models for studying discogenic LBP remain limited,impeding the development of targeted treatments.Existing therapies primarily focus on symptom management rather than addressing underlying disease mechanisms.
文摘Chronic pain and disability following acute orthopedic trauma are not only physical concerns but also deeply intertwined with psychological well-being.The recent retrospective cohort study by Yang et al,published,provides compelling evidence of significant associations between depression,anxiety,and postoperative recovery.These findings align with an expanding body of literature that confirms the need for orthopedic rehabilitation to adopt a biopsychosocial perspective.This letter contextualizes Yang et al’s study within current evidence,highlighting the roles of sleep disturbance,catastrophizing,stress,neurobiological mechanisms,and coping strategies in shaping recovery.It further emphasizes the importance of integrating nursing-led and multidisciplinary interventions to address both physical and psychological domains,ultimately promoting holistic recovery.
基金the Research Institute of Veterinary Science,College of Veterinary Medieine,Seoul National University
文摘AIM:Irritable bowel syndrome(IBS)is a functional bowel disorder characterized by visceral hypersensitivity and altered bowel motility.There is increasing evidence suggesting the role of inflammation in the pathogenesis of IBS,which addresses the possibility that formerly established rat model of colitis could be used as an IBS model after the inflammation subsided. METHODS:Colitis was induced by intracolonic instillation of 4% acetic acid in male Sprague-Dawley rats.The extent of inflammation was assessed by histological examination and myeloperoxidase(MPO)activity assay.After subsidence of colitis,the rats were subjected to rectal distension and restraint stress,then the abdominal withdrawal reflex and the number of stress-induced fecal output were measured, respectively. RESULTS:At 2 days post-induction of colitis,the colon showed characteristic inflammatory changes in histology and 8-fold increase in MPO activity.At 7 days post-induction of colitis,the histological features and MPO activity returned to normal.The rats at 7 days post-induction of colitis showed hypersensitive response to rectal distension without an accompaning change in rectal compliance,and defecated more stools than control animals when under stress.CONCLUSION: These results concur largely with the characteristic features of IBS, visceral hypersensitivity and altered defecation pattern in the absence of detectable disease, suggesting that this animal model is a methodologically convenient and useful model for studying a subset of IBS.
文摘In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given spatial temperature profile. Our model is distilled from sub-step components in the ADT CHEETEH-E model developed at the Institute for Defense Analyses. Our model has only two parameters: the activation temperature of nociceptors and the critical threshold on the activated volume. When the spatial temperature profile is measurable, the two parameters can be determined from test data. We connect this dose-response relation to a temperature evolution model for electromagnetic heating. The resulting composite model governs the process from the electromagnetic beam deposited on the skin to the binary outcome of subject’s reflex response. We carry out non-dimensionalization in the time evolution model. The temperature solution of the non-dimensional system is the product of the applied power density and a parameter-free function. The effects of physical parameters are contained in non-dimensional time and depth. Scaling the physical temperature distribution into a parameter-free function greatly simplifies the analytical solution, and helps to pinpoint the effects of beam spot area and applied power density. With this formulation, we study the theoretical behaviors of the system, including the time of reflex, effect of heat conduction, biological latency in observed reflex, energy consumption by the time of reflex, and the strategy of selecting test conditions in experiments for the purpose of inferring model parameters from test data.
文摘Objective · Formalin is a classic and most widely used algogenic substance, but its itchy effect is not clear. The present study aims to explore the hypothesis that formalin may induce itch as well as pain. Methods · Flinching, as well as licking and forelimb wiping of the site of injection were counted as pain responses, whereas biting and hind paw scratching of the cheek were counted as itchy responses. To discriminate formalin-induced sensations in rats, the irritant(saline as control) was injected, and then pain and itchy responses were recorded.Results · Intraplantar injection of formalin elicited biphasic behavior responses characterized as flinching, as well as biting or licking of the hind paw without significant gender differences. Following intradermal administration of formalin to the cheek, rats exhibited episodic forelimb wiping of the cheek, representative of pain. No gender difference was noticed for this type of behavior. In addition, episodes of hind paw scratches of the cheek, representative of pruritoceptive responses, also occurred. Interestingly, hind paw scratches appeared to be more pronounced in male than in female rats. Conclusion · Intradermal administration of formalin elicits pruritoceptive as well as nociceptive responses in rats.
基金the National Natural Science Foundation of China,No. 81171707the Major State Basic Research Program of China,No.2012CB933600+2 种基金Shanghai Pujiang Program,No.11PJD016China Postdoctoral Science Foundation,No. 20090460629Fund for Key Disciplines of Shanghai Municipal Education Commission,No.J50206
文摘A rat model of extra-vertebral foramen cervical nerve entrapment was established according to the following parameters： stimulation intensity 20 V; frequency 50 Hz; pulse width 200 μs; duration 333 ms/s for a total of 8 hours. After the electrical stimulation, rats exhibited mild muscle fiber atrophy, mild inflammatory exudates, connective tissue local fibrosis and chondrocyte metaplasia. Mean muscle fiber cross-sectional area was reduced. The nerve myelin sheath continuity was partially demyelinated. The microstructure of nerve cells was disrupted and these symptoms worsened with prolongation of the stimulation. The shoulder, neck and upper extremity muscles on the tested side demonstrated positive sharp waves and fibrillations. The severity increased with continuation of the stimulation. High amplitude and polyphasic motor unit potentials gradually appeared. Similar findings were seen in the contralateral side, but at a less severe level.
