The basic formulation of Al2O3- C slide plates was65%（ in mass,the same hereinafter） white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, a...The basic formulation of Al2O3- C slide plates was65%（ in mass,the same hereinafter） white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al ＋ 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al ＋ 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides： AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.展开更多
Objective:To investigate the effect of internal heat acupuncture on the tolerance time of plantar hot plate and the pain threshold of gastrocnemius in rats with chronic myofascial pain syndrome(MPS).Methods:A total of...Objective:To investigate the effect of internal heat acupuncture on the tolerance time of plantar hot plate and the pain threshold of gastrocnemius in rats with chronic myofascial pain syndrome(MPS).Methods:A total of 80 adult Wistar rats were randomly selected to establish chronic MPS rat models,and randomly divided into four groups:control group,acupuncture group,internal heat acupuncture group A,and internal heat acupuncture group B,with 20 rats in each group.The rats in the control group were not given any treatment,and the rats in the acupuncture group were only given acupuncture treatment.The rats in group A were treated with internal heat acupuncture(needle heating up to 42℃),and the rats in group B were treated with internal heat acupuncture(needle heating up to 44℃).The tolerance time of plantar hot plate,the pain threshold of gastrocnemius muscle and the level of tumor necrosis factor-α(TNF-α)were observed and compared before modeling,1 d before treatment,and 1,7 and 14 d after treatment.Results:There were significant differences in hot plate tolerance time,time and interaction among the four groups(P<0.05),as well as in gastrocnemius tenderness threshold,time and interaction among the four groups(P<0.05),and there were also significant differences in TNF-αlevel among the three groups(P>0.05).There were significant differences in the number of electric shocks,time and interaction among the four groups(P<0.05).Conclusion:In contrast to conventional acupuncture treatment,internal heat acupuncture demonstrates greater efficacy in extending the tolerance duration of hot plate exposure and enhancing the pain threshold of the gastrocnemius muscle in rats afflicted with myofascial pain syndrome.Additionally,it accelerates the amelioration of inflammatory markers and motor function.However,it is important to note that the therapeutic impact of internal heat acupuncture may be influenced by its temperature,with 44℃being the most effective in this research.展开更多
Pain is a sensation related to potential or actual damage in some tissue of the body. The mainstay of medical pain therapy remains drugs that have been around for decades, like non-steroidal anti-inflammatory drugs （...Pain is a sensation related to potential or actual damage in some tissue of the body. The mainstay of medical pain therapy remains drugs that have been around for decades, like non-steroidal anti-inflammatory drugs （NSAIDs）, or opiates. However, adverse effects of opiates, particularly tolerance, limit their clinical use. Several lines of investigations have shown that systemic （intraperitoneal） administration of NSAIDs induces antinociception with some effects of tolerance. In this review, we report that repeated microinjection of NSAIDs analgin, clodifen, ketorolac and xefocam into the central nucleus of amygdala, the midbrain periaqueductal grey matter and nucleus raphe magnus in the following 4 days result in progressively less antinociception compared to the saline control testing in the tail-flick reflex and hot plate latency tests. Hence, tolerance develops to these drugs and cross-tolerance to morphine in male rats. These findings strongly support the suggestion of endogenous opioid involvement in NSAIDs antinociception and tolerance in the descending pain-control system. Moreover, the periaqueductal grey-rostral ventro-medial part of medulla circuit should be viewed as a pain-modulation system. These data are important for human medicine. In particular, cross-tolerance between non-opioid and opioid analgesics should be important in the clinical setting.展开更多
Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-...Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].展开更多
目的观察不同剂量咪达唑仑对氯胺酮镇痛效应的影响,为临床合理配伍使用药物提供依据。方法腹腔注射25 mg/kg氯胺酮建立镇痛模型,150只小鼠均分为NS组、M组、K组、M1K组和M2K组,采用甩尾法、热板法和扭体法(n=10)分别观察腹腔注射1、2 mg...目的观察不同剂量咪达唑仑对氯胺酮镇痛效应的影响,为临床合理配伍使用药物提供依据。方法腹腔注射25 mg/kg氯胺酮建立镇痛模型,150只小鼠均分为NS组、M组、K组、M1K组和M2K组,采用甩尾法、热板法和扭体法(n=10)分别观察腹腔注射1、2 mg/kg咪达唑仑对氯胺酮镇痛小鼠甩尾潜伏期(TFL)、热板法痛阈(HPPT)和扭体次数(WTs)的影响。结果给药后5、10、15、20 min K组TEL、HPPT延长(P<0.05);各时点M组小鼠TFL、HPPT均无明显变化;M1K组和M2K组给药后10、15、20 min TFL、HPPT延长,给药后15 min M1K组和M2K组TEL、HPPT明显长于K组(P<0.05或P<0.01)。给药后15 min内K、M1K和M2K组小鼠WTs明显少于NS组(P<0.01)。但K、M1K和M2K组间差异无统计学意义(P<0.05或P<0.01)。结论一定剂量的咪达唑仑可以增强氯胺酮的体表镇痛作用。展开更多
文摘The basic formulation of Al2O3- C slide plates was65%（ in mass,the same hereinafter） white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al ＋ 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al ＋ 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides： AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.
文摘Objective:To investigate the effect of internal heat acupuncture on the tolerance time of plantar hot plate and the pain threshold of gastrocnemius in rats with chronic myofascial pain syndrome(MPS).Methods:A total of 80 adult Wistar rats were randomly selected to establish chronic MPS rat models,and randomly divided into four groups:control group,acupuncture group,internal heat acupuncture group A,and internal heat acupuncture group B,with 20 rats in each group.The rats in the control group were not given any treatment,and the rats in the acupuncture group were only given acupuncture treatment.The rats in group A were treated with internal heat acupuncture(needle heating up to 42℃),and the rats in group B were treated with internal heat acupuncture(needle heating up to 44℃).The tolerance time of plantar hot plate,the pain threshold of gastrocnemius muscle and the level of tumor necrosis factor-α(TNF-α)were observed and compared before modeling,1 d before treatment,and 1,7 and 14 d after treatment.Results:There were significant differences in hot plate tolerance time,time and interaction among the four groups(P<0.05),as well as in gastrocnemius tenderness threshold,time and interaction among the four groups(P<0.05),and there were also significant differences in TNF-αlevel among the three groups(P>0.05).There were significant differences in the number of electric shocks,time and interaction among the four groups(P<0.05).Conclusion:In contrast to conventional acupuncture treatment,internal heat acupuncture demonstrates greater efficacy in extending the tolerance duration of hot plate exposure and enhancing the pain threshold of the gastrocnemius muscle in rats afflicted with myofascial pain syndrome.Additionally,it accelerates the amelioration of inflammatory markers and motor function.However,it is important to note that the therapeutic impact of internal heat acupuncture may be influenced by its temperature,with 44℃being the most effective in this research.
基金supported by the grant from Georgian National Science Foundation,No.GNSF/ST07/6-234
文摘Pain is a sensation related to potential or actual damage in some tissue of the body. The mainstay of medical pain therapy remains drugs that have been around for decades, like non-steroidal anti-inflammatory drugs （NSAIDs）, or opiates. However, adverse effects of opiates, particularly tolerance, limit their clinical use. Several lines of investigations have shown that systemic （intraperitoneal） administration of NSAIDs induces antinociception with some effects of tolerance. In this review, we report that repeated microinjection of NSAIDs analgin, clodifen, ketorolac and xefocam into the central nucleus of amygdala, the midbrain periaqueductal grey matter and nucleus raphe magnus in the following 4 days result in progressively less antinociception compared to the saline control testing in the tail-flick reflex and hot plate latency tests. Hence, tolerance develops to these drugs and cross-tolerance to morphine in male rats. These findings strongly support the suggestion of endogenous opioid involvement in NSAIDs antinociception and tolerance in the descending pain-control system. Moreover, the periaqueductal grey-rostral ventro-medial part of medulla circuit should be viewed as a pain-modulation system. These data are important for human medicine. In particular, cross-tolerance between non-opioid and opioid analgesics should be important in the clinical setting.
基金supported by CAPES/PROEX,FAPESP(2010/10936-5)A.F.Donatti has a doctorate scholarship from CAPESC.R.A.Leite-Panissi also received grants from the CNPq(Grant No.307383/2012-1).
文摘Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].
文摘目的观察不同剂量咪达唑仑对氯胺酮镇痛效应的影响,为临床合理配伍使用药物提供依据。方法腹腔注射25 mg/kg氯胺酮建立镇痛模型,150只小鼠均分为NS组、M组、K组、M1K组和M2K组,采用甩尾法、热板法和扭体法(n=10)分别观察腹腔注射1、2 mg/kg咪达唑仑对氯胺酮镇痛小鼠甩尾潜伏期(TFL)、热板法痛阈(HPPT)和扭体次数(WTs)的影响。结果给药后5、10、15、20 min K组TEL、HPPT延长(P<0.05);各时点M组小鼠TFL、HPPT均无明显变化;M1K组和M2K组给药后10、15、20 min TFL、HPPT延长,给药后15 min M1K组和M2K组TEL、HPPT明显长于K组(P<0.05或P<0.01)。给药后15 min内K、M1K和M2K组小鼠WTs明显少于NS组(P<0.01)。但K、M1K和M2K组间差异无统计学意义(P<0.05或P<0.01)。结论一定剂量的咪达唑仑可以增强氯胺酮的体表镇痛作用。
