电针对大鼠尾核痛兴奋,痛抑制神经元放电和甩尾反射的影响

浅麻醉ｗｉｓｔａｒ大鼠２５只,用Ｇ－６８０５型治疗仪电针刺激双侧“足三里”。以辐射热照尾部作为伤害性刺激,将痛兴奋神经元（ＰＥＮ）诱发放电频率减少,痛抑制神经元（ＰＩＮ）诱发放电频率增加和甩尾反射潜伏期（ＴＦＬ）延长作为镇痛效应,观察电针刺激“足三里”对尾核中ＰＥＮ、ＰＩＮ及ＴＦＬ的影响。结果表明,电针刺激“足三里”,尾核中ＰＥＮ、ＰＩＮ放电及ＴＦＬ均显示镇痛效应;电针对ＰＥＮ、ＰＩＮ放电及ＴＦＬ的影响高峰均出现在电针后即刻;电针前ＰＥＮ放电频率增加、ＰＩＮ放电频率减少与甩尾反射（ＴＦ）相伴行。放电变化发生在ＴＦ之前,结束在ＴＦ之后,ＰＥＮ、ＰＩＮ放电变化与ＴＦＬ呈高度正相关。镇痛作用高峰期ＰＥＮ、ＰＩＮ放电变化仍在ＴＦ前,结束在ＴＦ之后,两者呈高度正相关。提示尾核中的ＰＥＮ、ＰＩＮ是痛觉调节中枢的一部分,可能参与对ＴＦ的调节。     

Partial purification and characterization of a soluble protein phosphatase fromLeishmania donovani promastigotes

A soluble protein phosphatase from the promastigote form of the parasitic protozoanLeishmania donovani was partially purified using Sephadex G-100, DEAE-cellulose and again Sephadex G-100 columns. The partially purified enzyme showed a native molecular weight of about 42, 000 in both Sephadex G-100 and sucrose density gradient centrifugation. The sedimentation constant, stokes radius and frictional ratio were found to be 3.43S, 2.8 nm and 1.20 respectively. The enzyme preferentially utilized phosphohistone as the best exogenous substrate. Mg²⁺ ions were essential for enzyme activity; among other metal ions Mn²⁺ can replace Mg²⁺ to a certain extent whereas Ca²⁺, Co²⁺ and Zn²⁺ could not substitute for Mg²⁺. The pH optimum of the enzyme was 6.5–7.5 and the temperature optimum 37°C. The apparent Km for phosphohistone was 7.14 M. ATP, ADP, inorganic phosphate and pyrophosphate had inhibitory effect on the enzyme activity whereas no inhibition was observed with sodium tartrate and okadaic acid. These results suggest thatL. donovani promastigotes possess a protein phosphatase which has similar characteristics with the mammalian protein phosphatase 2C.Abbreviations PMSF phenylmethylsulfonyl fluoride - DTT dithiothreitol - TCA trichloroacetic acid - BSA bovine serum albumin - EDTA ethylenediamine tetraacetic acid - ATP adenosine triphosphate - ADP adenosine diphosphate - AMP adenosine monophosphate - EGTA Ethyleneglycol-bis-(-aminoethyl ether) N,N,N,N-tetraacetic acid     

损毁或刺激垂体和下丘脑弓状核对大鼠痛觉调制的影响

用局限性损毁和刺激垂体的方法,观察了垂体与下丘脑弓状核（ＡＲＣ）在痛觉调制中的关系。实验结果表明,损毁垂体中间叶和前叶能降低基础痛阈,取消刺激ＡＲＣ即刻出现的镇痛作用。刺激垂体的相同部位能提高基础痛阈,并出现有一定潜伏期的镇痛作用,这个镇痛作用能被损毁ＡＲＣ所阻断。     

Linear spectrum and non-linear complexity features of lumbar muscle surface electromyography between people with and without non-specific chronic low back pain during Biering-Sorensen test

PurposeThis study aimed to investigate the electromyographic parameters of lumbar muscles during the Biering-Sorensen test (BST) in people with and without non-specific chronic low back pain (NCLBP).Materials and methodsThirteen healthy controls and thirteen NCLBP patients participated in the current study, where they performed the 90s-BST, while the surface electromyography (sEMG) was recorded from the erector spinae (ES) at L1 and L3 level and lumbar multifidus (LM) at L5 level, bilaterally. Spectral and nonlinear analyses were applied by calculating mean power frequency (MPF), fractal dimension (FD) and the percentage of determinism (%DET) in the 10-second non-overlapping time-windows and EMG-EMG coherence during the first half and second half of the BST. Also, the slopes of the linear fitting curves of MPF, FD and %DET were calculated.ResultsNCLBP group had significantly lower rates of changes in MPF, FD and %DET compared to asymptomatic controls in the ES(L3) and LM. Coherence in left–right LM and in the right ES-LM increased significantly in the gamma band in the Control group with no increase in the NCLBP group.ConclusionsOur findings indicated that compared to people with NCLBP, the sEMG signals of lumbar muscles of people without NCLBP were more regular and less complex during the 90s-BST.     

Activation of vascular endothelial cells by synovial fibrosis promotes Netrin-1-induced sensory nerve sprouting and exacerbates pain sensitivity

Synovial fibrosis is one of the most dominant histopathological changes in osteoarthritis of the knee (KOA), and activation of vascular endothelial cells in synovial fibrosis is both an important factor in mediating pain in KOA and a major contributor to the generation of pain signals. At the same time, angiogenesis and nerve fibres are more likely to underlie the pathology of pain induced by synovial fibrosis. In the present study, we established a co-culture model of human umbilical vein endothelial cells (HUVECs) with dorsal root ganglion (DRG) and detected tissue and cellular Netrin-1, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), growth-associated protein-43 (GAP43), colorectal cancer deleted (DCC), uncoordinated 5 (UNC5), and the related expression of calcitonin gene-related peptide (CGRP), substance P (SP) and nerve growth factor (NGF) in supernatant by ELISA to investigate the intervention of vascular endothelial cell activation on sensory nerve sprouting exacerbating peripheral pain sensitivity and to investigate the effect of Netrin-1 from the perspective of Netrin-1 secretion to illustrate its effector mechanism.     

Leishmania donovani: action of excreted factor on hydrolytic enzyme activity of macrophages from mice with genetically different resistance to infection

The effect of purified excreted factor from promastigotes of Leishmania donovani upon the activity of four enzymes from lysed peritoneal exudate cells of mice (C3H and C57BL) was determined. There was no demonstrable effect on acid phosphatase (EC3.1.3.2), β-glucuronidase (EC3.2.1.21), and N-acetyl-β-glucosaminidase (EC3.2.1.29), but β-galactosidase (EC3.2.1.23) was inhibited up to 72% after 3 hr of incubation at 37 C. Inhibition of C57BL mouse enzymes was not significantly different from that of C3H mice. Protamine sulfate combined with the highly negatively charged excreted factor of L. donovani to migrate as a single positively charged band on immunoelectrophoresis. Protamine sulfate also reversed the β-galactosidase inhibition, though this was without direct effect on the enzyme. The excreted factor did not change or lose its charge or antigenicity with regard to precipitating antibody, when incubated with extracts of mouse peritoneal exudate cells, splenocytes, or liver homogenate—irregardless of whether the mice had been infected with leishmaniasis for 1 or 2 weeks or were uninfected.     

一足致炎大鼠双足伤害感受性的变化

大鼠一侧鹿角菜致炎足痛阈显著降低后,对侧非致炎足的痛阈出现显著降低、不变,和显著升高等变化。对侧非致炎足痛阈的这三种变化与致炎足痛阈降低幅度的大小显著相关。     

Biofeedback-assisted relaxation training for the aging chronic pain patient

The older segments of the U.S. population are expanding rapidly and account for a disproportionate amount of health care, including treatment for pain-related musculoskeletal disorders. In a prospective study with objective measures and one-year follow-up, Middaugh et al. (1988) found that older patients (55–78 yr; N=17, 76% success) treated in a multidisciplinary chronic pain rehabilitation program enjoyed a success rate equal to that of younger patients (29–48 yr; N=20, 70% success). The current study presents additional data on these two groups of patients to compare their ability to learn the physiological self-regulation skills taught in the biofeedback/relaxation component of the multimodal program. This component included progressive muscle relaxation training, diaphragmatic breathing instruction, and EMG biofeedback. Repeated measures ANOVA showed significant increases in digital skin temperature (peripheral vasodilation) and decreases in respiration rate both within and across training sessions (p values=.04 to .0001) with no differences between age groups (p>.05). EMG measures for the upper trapezius ms in patients with cervical pain showed similar deficits in muscle control at evaluation and similar improvements with biofeedback training for the two age groups. These findings indicate that older pain patients responded well to the biofeedback/relaxation training component of the multimodal pain program.This research was supported in part by NIDRR grant No. H133G90085, Department of Education, DHEW, and by the Medical University of South Carolina General Clinical Research Center under NIH grant No. RR1070.     

TAFA4 Reverses Mechanical Allodynia through Activation of GABAergic Transmission and Microglial Process Retraction

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