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Abstract Background Myasthenia gravis (MG) is an autoimmune disease usually caused by antibodies against the acetylcholine receptor (AChR-Abs), muscle-specific tyrosine kinase (MuSK-Abs), or low-density lipoprotein receptor-related protein 4 (LRP4-Abs). However, there are MG patients who do not have these antibodies and are thus said to have triple-seronegative (triple-SN) MG. Objective This study aims to describe the frequency and clinical and epidemiological characteristics of patients with triple-SN MG. Methods This was a retrospective cross-sectional study carried out through the analysis of medical records. Descriptive and analytical statistical analysis was performed comparing subgroups of myasthenic patients, classified according to serological profile. Results The sample population consisted of 93 MG patients: 85 were positive for antibodies, 80 (86%) with AChR-Abs, 5 (5.4%) with MuSK-Abs, and no MG patients with LRP4-Abs. Eight patients (8.6%) had triple-SN MG; they had a median age at disease onset of 30 years (21-45). Their most common initial symptoms were ptosis, diplopia, and generalized weakness. Most patients presented with mild symptoms at their last visit, reflecting a median MG composite scale score of 4 (0-6), and 75% of patients had an adequate response to treatment. Conclusion Our study showed a low frequency of triple-SN MG in Brazilian MG patients. Triple-SN MG was predominant in females, who presented with ptosis, diplopia, and generalized weakness, and most patients had an adequate response to immunosuppressive treatment. There was no significant difference between triple-SN MG and the other subgroups.
Resumo Antecedentes A Miastenia gravis (MG) é uma desordem autoimune geralmente causada por anticorpos antirreceptores de acetilcolina (anti-RACh), tirosina quinase músculo-específica (anti-MuSK) ou proteína 4 relacionada ao receptor de lipoproteína de baixa densidade (anti-LRP4). No entanto, em uma parcela dos pacientes, nenhum destes três anticorpos pôde ser detectado, sendo estes casos denominados "triplo-soronegativos". Objetivo Descrever a frequência, bem como as características clínicas e epidemiológicas dos pacientes com MG triplo-soronegativa. Métodos Consiste em um estudo transversal e restrospectivo, realizado através da análise de prontuários médicos. Foi realizada análise estatística descritiva e analítica entre os subgrupos de pacientes, classificados de acordo com o perfil sorológico. Resultados A população consistiu de 93 pacientes com MG: 85 pacientes apresentavam positividade para anticorpos, sendo 80 (86%) com anticorpos anti-RACh, cinco (5,4%) com anti-MuSK, e não foram encontrados pacientes com anti-LRP4. Oito (8,6%) eram pacientes triplo-soronegativos, que apresentaram idade média de início da doença de 30 anos (21-45), e com sintomas iniciais mais comuns de ptose, diplopia e fraqueza generalizada. 75% dos pacientes triplo-soronegativos apresentaram resposta adequada ao tratamento. Conclusão O estudo demonstrou uma baixa frequência da pacientes com MG triplo-soronegativa na população brasileira. A MG triplo-soronegativa foi predominante nas mulheres, que se apresentaram com ptose, diplopia ou fraqueza generalizada, e a maioria dos pacientes apresentou resposta adequada ao tratamento imunossupressor. Não houve diferença significativa entre a MG triplo-soronegativa e os demais subgrupos.
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Objective To evaluate the changes in the expression of hippocampal α7 nicotinic ace-tylcholine receptor (α7nAChR) , acetylcholinesterase ( AChE) and choline acetyltransferase ( ChAT) after sevoflurane anesthesia in neonatal rats. Methods Seventy-two healthy Sprague-Dawley rats of both sexes, aged 7 days, weighing 25-40 g, were divided into 3 groups ( n=24 each) using a random number table method: control group ( group C) , air and oxygen group ( group A∕O) and sevoflurane group ( group S) . Rats were exposed to carrier gas ( air 1 L∕min plus oxygen 1 L∕min) for 2 h in group A∕O. Rats were ex-posed to 3. 4％ sevoflurane in carrier gas for 2 h in group S. Eight rats in each group were selected at 2 h, 1 week and 4 weeks after the end of inhalation, and sacrificed, brains were removed and hippocampal tis-sues were obtained for determination of α7nAChR, AChE and ChAT protein and mRNA by Western blot and real-time polymerase chain reaction, respectively. Results Compared with group A∕O, the expression of α7nAChR mRNA was significantly down-regulated at each time point after the end of inhalation, and the expression of TnAChR was down-regulated at 2 h after the end of inhalation and up-regulated at 1 week after the end of inhalation, the expression of AChE mRNA was up-regulated at 2 h after the end of inhalation and down-regulated at 4 weeks after the end of inhalation, the expression of AChE was down-regulated at 4 weeks after the end of inhalation, the expression of ChAT mRNA was up-regulated at 2 h after the end of in-halation, and the expression of ChAT was down-regulated at each time point after the end of inhalation in group S ( P<0. 05) . Conclusion The expression of hippocampal α7nAChR is down-regulated at first and then up-regulated after sevoflurane anesthesia, the expression of ChAT and AchE in the later period is down-regulated, the tendency of protein expression mentioned above is different from that of its mRNA ex-pression, suggesting that sevoflurane may affect the protein expression through other pathways.
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Objective To evaluate the effect of sevoflurane anesthesia on the expression of hippocampal α4 subunit-containing nicotinic acetylcholine receptor (α4nAChR) in rats.Methods One hundred and forty-four Sprague-Dawley rats of both sexes,aged 3-4 months,weighing 220-270 g,were divided into 4 groups (n =36 each) using a random number table:control group (group C),sevoflurane anesthesia for 1 h group (group S1),sevoflurane anesthesia for 3 h group (group S2) and sevoflurane anesthesia for 5 h group (group S3).Group C inhaled air,and S1,S2 and S3 groups inhaled 3％ sevoflurane for 1,3 and 5 h,respectively.Twelve rats in each group were selected at 1 and 7 days after emergence from anesthesia to undergo spatial probe test.Rats were then sacrificed immediately after anesthesia and at 1 and 7 days after emergence from anesthesia,and hippocampi were removed for determination of the expression of α4nAchR protein and mRNA in hippocampal neurons (by Western blot or real-time polymerase chain reaction).Results Compared with group C,the duration of staying at the target quadrant was significantly shortened,and the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 and 7 days after emergence from anesthesia,the expression of α4nAchR protein and mRNA was down-regulated,and the number of positive cells was reduced in S1,S2 and S3 groups (P＜0.05).Compared with S1 and S2 groups,the duration of staying at the target quadrant was significantly shortened,the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 day after emergence from anesthesia in group S3 (P＜0.05).There was no significant difference in the expression of α4nAchR protein and mRNA or number of positive cells at each time point between group S1,group S2 and group S3 (P＞0.05).Conclusion The mechanism by which sevoflurane anesthesia induces cognitive dysfunction may be partially related to down-regulating the expression of hippocampal α4nAchR in rats.
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Objective To explore the clinical differences between patients with early-onset myasthenia gravis (EOMG)and those with late-onset myasthenia gravis(LOMG).Methods This was a retrospective study enrolling 157 MG patients.Based on the age of onset,patients were divided into the EOMG group(n=85)and the LOMG group(n =72).The groups were compared on clinical characteristics,including clinical manifestations,MG classification,electrophysiological findings on repetitive nerve stimulation(RNS),single fiber electromyography(SFEMG),levels of antibody against acetylcholine receptors(Ach-R Ab),antibody to muscle-specific kinase(MuSK Ab),titin antibody(Titin Ab),ryanodine receptor antibody(RyR Ab),thyroid function,thymectomy,thymus pathology and responses to treatment.Results The mean ages of onset were markedly different [(40.9 ± 9.7) years vs.(62.0 ± 12.2) years,P＜ 0.05] between the EOMG and LOMG groups.The LOMG group was associated with a significantly higher rate of the ocular form(50.0 ％,n=36 vs.32.9％,n=28,P＜0.05),a lower rate of the general form(50.0％,n=36 vs.67.1％,n=57,P＜0.05),and an increased risk of bulbar involvement(41.7％ n=30 vs.23.5％,n=20,P＜0.05)than those in the EOMG group.There was no significant difference in positive rates of RNAS and SFEMG,and levels of AChR Ab,MuSK Ab and double serum negative(DSN)MG between the groups (P＞0.05).Moreover,patients in the EOMG group were more likely to have abnormal thyroid function and higher percentages of receiving steroids,tacrolimus,plasma exchange therapy,and thymectomy (P＜ 0.05).Conclusions The clinical profiles of LOMG are different from those of EOMG in clinical manifestations,thyroid function,thymectomy frequency,striational antibody levels and disease-modifying drug options.
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Objective To evaluate the role of different nicotinic acetylcholine receptor ( nAChR) subtypes in skeletal muscles in sepsis-related nerve-muscle dysfunction in septic rats by neuroelectrophysiol-ogy. Methods SPF adult male Sprague-Dawley rats, weighing 200-220 g, aged 2-3 months, were stud-ied. Sepsis was induced by cecal ligation and puncture in chloral hydrate-anesthetized rats. Twelve portions of sciatic nerve-tibialis anterior muscles taken at day 3 after successful establishment of the sepsis modelserved as group S. Another 12 portions of sciatic nerve-tibialis anterior muscles of normal rats served as group C. The endplate potential ( EPP ) was monitored by intracellular microelectrode recording. Six por-tions of nerve-muscle samples were incubated with the adult nAChR (ε-nAChR ) specific antagonist wa-glerin-1 at a concentration of 1 μmol∕L, the fetal nAChR (γ-nAChR) specific antagonist αA-OIVA at a concentration of 250 nmol∕L and neuronal nAChR (α7-nAChR) antagonist methyllycaconitine ( MLA) at a final concentration of 6 nmol∕L. The amplitude of EPP was recorded at 15 min of incubation, and the differ-ence in the amplitude of EPP (ΔEPP) and changing rate of EPP (ΔEPP％) were calculated. Another 6 portions of samples were incubated for 15 min with the Kreb mixture of waglerin-1 and 250 nmol∕LαA-OIVA at a final concentration of 1 μmol∕L, the Kreb mixture of waglerin-1 and 6 nmol∕L MLA at a final concen-tration of 1 μmol∕L, and the Kreb mixture of αA-OIVA and 6 nmol∕L MLA at a final concentration of 250 nmol∕L, and then the amplitude of EPP was recorded. Washout was performed with antagonist free Kreb so-lution for 15 min between treatments with different blockers. Results Compared with group C, ΔEPP andΔEPP％ were significantly decreased after antagonizing ε-nAChR, ΔEPP％ was decreased after antagoni-zing γ-nAChR, ΔEPP and ΔEPP％ were increased after antagonizing α7-nAChR, the amplitude of EPP was increased after antagonizingε-nAChR+γ-nAChR andε-nAChR+α7-nAChR, and the amplitude of EPP was decreased after antagonizing γ-nAChR+α7-nAChR (P<0. 05). ΔEPP and ΔEPP％ were significantly higher after antagonizing α7-nAChR than after antagonizingγ-nAChR in group S ( P<0. 05) . The EPP was significantly lower after antagonizingε-nAChR+α7-nAChR than after antagonizingε-nAChR+γ-nAChR ( P<0. 05) . Conclusion Weakened function of ε-nAChR and enhanced function of α7-nAChR in the mem-brane of the end-plate in skeletal muscle are the main reasons for sepsis-related nerve-muscle dysfunction in septic rats, and the role is comparable between them.
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Objective:To investigate the anti-inflammation effects by activation of the cholinergic anti-inflammatory pathway and its mechanisms in non-alcoholic steatohepatitis (NASH)model mice.Me-thods:6-week-old male C57BL/6J (B6)mice were randomly divided into four groups:the first group was normal mice,injected with saline;the second group was normal mice,injected with nicotine;the third group was NASH model mice,injected with saline;the fourth group was NASH model mice,injec-ted with nicotine.The experimental mice were fed with either standard chow (SC)or high-fat and high-fructose (HFHF)for 17 weeks to generate an NASH model mice.The mice received injection once daily for 3 weeks [nicotine dose,400 μg/kg].Then,their pathological characteristics and function of the liver were assessed.The expressions of interleukin-6 (IL-6)and tumor necrosis factor-α(TNF-α)in se-rum were analyzed by enzyme linked immunosorbent assay (ELISA).The expressions of alpha 7 nicotinic acetylcholine receptors (α7nAChR),Toll-like receptors-4 (TLR-4)and nuclear factor κB of phosphory-lation (p-NF-κB)in Kupffer cells were determined by Western blot and immunofluorescence assays.Re-sults:We successfully generated NASH model mice by imitating the high-fat and high-fructose dietary style of NASH patients.The results of our investigation demonstrated that nicotine could reduce signifi-cantly the levels of IL-6,and TNF-αin serum (P <0.05).The expression of p-NF-κB protein in the group which was NASH model mice injected with nicotine declined significantly as compared with the group which was NASH model mice injected with saline (P <0.05).And the expression of α7nAChR protein elevated significantly conversely (P <0.05 ).Conclusion:Activation of the cholinergic anti-inflammatory pathway could inhibit the release of inflammatory factors as TNF-αand IL-6 in NASH model mice,and the mechanism for the inhibition of inflammatory was mediated by NF-κB pathway.
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Objective To investigate the effect of rat macrophage α7-acetylcholine receptor (α7-AChR )-mediated cholinergic anti-inflammatory pathway on endotoxin-induced inflammation reaction . Methods Density gradient centrifugation method was used to isolate rat primary macrophages and flow cytometry was used to identify the cell purity .α7-AChR in macrophages was detected by fluorescence confocal microscopy and Western blot .After 1ipopolysaccharides ( LPS) was added to the culture media of primary culture of macrophages , the concentration of tumor necrosis factor ( TNF)-αin the supernatant was determined by enzyme linked immunosorbent assay (ELISA).The expression of p-NF-κB protein in primary cultured macrophages was detected by Western blot .ANOVA was used to analyze TNF-αlevels after adding different concentrations of nicotine .Results α7-AChR was observed by fluorescence confocal microscope in primary macrophages .Nicotine could significantly reduce the concentration of TNF-αin culture supernatants of macrophages after LPS stimulation .When the concentrations of nicotine were 0, 1, 10, 100μmol/L, the concentrations of TNF-αwere (2 123 ±86), (1 486 ±80), (1 316 ±83) and (1 090 ±77)pg/mL, respectively (t=16.33, 20.18 and 26.83, P<0.05).The level of p-NF-κB in macrophages was also reduced when nicotine added .Conclusion Activation of macrophage α7-AChR can inhibit the endotoxin-induced release of inflammatory factor TNF-α, which may be through NF-κB signal pathway .
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Objective To evaluate the effect of advanced age on sepsis-caused heterogeneity of nicotinic acetylcholine receptors (nAChR) in the cytomembrane of skeleton muscle in rats.Methods Twenty SPF adult rats (aged 4-5 months,weighing 250-280 g) and 20 aged male Sprague-Dawley rats (aged 18-20 months,weighing 550-600 g),were obtained from the Experimental Animal Centre of Chongqing Medical University.The adult rats were randomly divided into control group (CAd group,n =10) and sepsis group (SAd group,n =10).The aged rats were randomly divided into control group (CAg group,n =10) and sepsis group (SAg group,n =10).Sepsis was produced by cecal ligation and puncture.The specimens of anterior tibial muscle were obtained at 24 h after operation for determination of the expression of neuronal nAChR (α7-nAChR) and fetal nAChR (γ-nAChR) using immunohistochemistry and Western blot.Results The expression of γ-nAChR and α7-nAChR in the cytomembrane of anterior tibial muscle was significantly higher in CAg and SAd groups than in CAd group,and in SAg group than in CAg and SAd groups.Conclusion Advanced age can aggravate sepsis-induced heterogeneity of nAChR in the cytomembrane of skeleton muscle in rats.
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Objective To investigate the relationship between changes of cholinergic system and memory ability impairment in rats long-term exposed to hypoxia-hypercapnia.Methods Forty-eight SD rats were randomly divided into control group,2 weeks hypoxia-hypercapnia group and 4 weeks hypoxiahypercapnia group.The chronic hypoxia-hypercapnia rat model was set up.The memory ability was assessed by eight-arm radial maze.Morphological changes were observed by the HE staining and Nissl staining.Acetylcholine(ACh) content,choline acetyl-transferase (ChAT) activity and acetyl-cholinesterase (AChE) activity in the hippocampus were detected by spectrophotometry,while expression of α7 neuronal nicotinic acetylcholine receptor (α7 nAChR) protein by Western blot.Results Memory ability,especially the working memory was impaired in rats exposed to chronic hypoxia-hypercapnia.And the memory ability decreased more markedly in four weeks group.Compared with those of normoxic rats,the levels of ACh and the activities of AChE and ChAT in the hippocampus of the two weeks group were significantly decreased (ACh:(58.9 ±2.7) vs (47.4 ±3.2) μg/mg (protein) ; AChE:(0.326 ±0.019) vs (0.247 ±0.020) U/mg (protein) ; ChAT:(127.1 ±8.6) vs (90.4 ±6.9) U/g (tissue wet weight),t =7.674,8.139,9.408,all P ＜ 0.05).Compared with the two weeks group,those changes were more obvious in the four weeks group rats (ACh:(47.4 ±3.2) vs (32.5 ±3.2) μg/mg (protein); AChE:(0.247 ±0.020),(0.170±0.019) U/mg (protein); ChAT:(90.4 ±6.9),(55.6 ±6.0) U/g (tissue wet weight),t =9.279,8.036,10.781,all P ＜ 0.05).Compared with the normoxic rats,the expressions of α7 nAChR protein were significantly decreased in two weeks group rats (t =4.481,P ＜ 0.05).Moreover,the expressions of α7 nAChR protein were significantly decreased in four weeks group rats comparing with the two weeks group (t =4.965,P ＜ 0.05).Conclusions An impairment of rat' s memory ability may be induced by hypoxia-hypercapnia,and the injury degree is correlated with the exposure time.Cholinergic system dysfunctions may contribute to the memory function defects in chronic hypoxia-hypercapnia rats.
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There exist many studies on the radioligands for imaging of nicotinic acetylcholine receptors (nAChRs) in the human brain and the most common one is the radioligand binding to α4β2-nAChRs,the main subtype of cerebral nAChRs.There are few data published in the literature on the radioligands for the imaging of α7-nAChRs,another important subtype of cerebral nAChRs.This review summarizes recent work on PET radioligands for the imaging of cerebral nAChRs.
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Objective To compare the density of acetylcholine receptor (AchR) in orbicular muscle of mouth and gastrocnemius muscle and their affmity with rocuronium, trying to elucidate the mechanism for the difference in the sensitivity of the muscles innervated by facial and peripheral nerve respectively to muscle relaxant.Methods Eight pathogen-free adult male SD rats weighing 180-220 g were used in this study. Muscle strips were isolated from orbicular muscle of mouth and gastrocnemius muscle. Each muscle strip was further divided into 6 smaller and slender strips of same size using dissection microscope. One strip was stained with acetylcholinesterase to measure end-plate surface area (ESA). The other 5 strips were exposed to different concentrations of rocuronium (0, 2.5, 5.0, 7.5, 10.0μg/ml). The mean density of AchR at end-plate was obtained by AchR0/ESA. (AchR0 was defined as the number of AchR per end-plate without being exposed to rocuronium. AchRE was defined as the number of free AchR per end-plate after being exposed to different concentrations of rocuronium. ) The degree of saturation of AchR with different concentrations of rocuronium at each neuromuscular junction was calculated by (AchR0 - AchRE)/AchR0 which reflects the affinity of AchR with the rocuronium in orbicular muscle of mouth and gastrocnemius muscle. Results The density of AchR was significantly lower while the affinity with rocuronium was higher in gastrocnemius muscle than in orbicular muscle of mouth ( P ＜ 0.05). Conclusion The density of AchR is lower and the affinity of AchR at end-plate with rocuronium is significantly greater in gastrocnemius muscle innervated by sciatic nerve than in orbicular muscle of mouth innervated by facial nerve. This may explain the mechanism for different sensitivity of the muscles innervated by facial and peripheral nerves to rocuronium.
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Objective To investigate the effect of different duration skeletal muscle denervation on acetylcholine receptor activity in rats.Methods Fourteen Balb/c mice weighing 18-22 g were used in this study.The denervation model was established by excising sciatic nerve.Two rats were chosen before(T0 ) and at days 1,4,7,14,21 and 28 after excising sciatic nerve (T1～6),and flexor digitorum brevis of the hindfoot was acutely isolated Skeletal muscle cells were isolated ( five cells in each rat),the acetylcholine currents were recorded using whole-cell patch-clamo technique.Extracellular fluid containing 30 μmol/L acetylcholine was first applied to skeletal muscle cells for 10 s,acetylcholine currents (11)were recorded,then the ceils were washed out using extracellularfluid.Skeletal muscle cells were balanced using extracellular fluid containing 0,0.1,1,10,30,100,1000,3000,or 10 000 nmol/L atracurium for 3 min respectively,then perfused using extracellular fluid containing 30 μmol/L acetylcholine and differents concentrations of atracurium mentioned above for 10 s respectively,and acetylcholine currents were recorded,then the cells were washed out,and 30 μmol/L acetylcholine was perfused again and currents(I2 ) were recorded.The mean value of I1 and I2 was taken as control current,and inhibitory percentage of control current was calculated,and the inhibition concentrations for the half-maximal response (IC50) of atracurium were determined by nonlinear regression analysis.Results Compared with T0,IC50 significantly increased at T1～6 ( P ＜ 0.05).IC50 was increased gradually at T1～3 ( P ＜ 0.05).Compared with T3,IC50 was decreased at T4～6 ( P ＜ 0.05).IC50 was decreased gradually at T4～6 ( P ＜ 0.05 ).Conclusion Skeletal muscle denervation can inhibite acetylcholine receptor activity,which is relate to the denervation time.
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Objective To investigate the effect of penehyclidine hydrochloride (PHCD) on tramadol dependence and c-fos,△ FosB and M5 receptor expression in relevant brain regions in rats.Methods Thirty male adult SD rats weighing 180-220 g were randomly assigned to 3 groups (n =10 each):control group (group C),tramadol dependence group (group T) and PHCD group (group P).Tramadol dependence was induced by subcutaneous 10 mg/kg once a day for 7 consecutive days in groups T and P.PHCD 1.5 mg/kg was injected intraperitoneally on day 8 in group P,while in groups C and T the equal volume of normal saline was injected intraperitoneally instead of PHCD.The rats underwent conditioned place perference test at 30 min after intraperitoneal injection.The time spent in drug-paired side (gray area) was recorded.The rats were sacrificed after the conditioned place perference testand the brain was removed.The relevant brain regions (ventral tegmental area,prefrontal cortex,nucleus accumbens )were separated for determination of c-fos,△ FosB expression by Western blot and M5 receptor mRNA expression by RT-PCR.Results Compared with group C,the time spent in the drug-paired side (gray area) was significantly prolonged,and c-fos,△FosB and M5 receptor mRNA expressions were up-regulated in group T,△FosB and Ms receptor mRNA expressions were down-regulated in group P ( P ＜ 0.05 or 0.01 ).There was no significant difference in time spent in the drug-paired side (gray area) and c-fos expression between groups C and P( P ＞ 0.05).Compared with group T,the time spent in the drug-paired side (gray area) was significantly shortened,and c-fos,△ FosB and M5 receptor mRNA expressions were down-regulated in group P (P ＜0.01).Conclusion PHCD can significantly inhibit tramadol dependence by down-regulating c-fos,△FosB and M5 receptor expression in relevant brain regions.
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Objective To investigate the effect of the mascarinic acetylcholine receptor (mAChR) agonist Oxo-tremorine-M (Oxo-M) on glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) and micro-inhibitory postaynaptic currents (mIPSCs) in lamina Ⅱ neurons in the spinal cord of rats. Methods Glycinergic IPSCs (sIPSCs and mIPSCs) in lamina Ⅱ neurons of spinal slices were recorded using the whole-cell voltage-clamp method. The non-selective mAchR ngonist Oxo-M was applied through bath perfusian. The effects of Oxo-M 1, 3, 5 and 10 μmol/L on sIPSCs and mIPSCs were examined. Results Oxo-M at the concentrations of 3-10 μmol/L significantly increased the frequency of sIPSCs without changing the amplitude in 16 lamina Ⅱ neurons tested. Interestingly, when the concentration of Oxo-M was increased to 10 μmol/L, the potentiating effect of Oxo-M on the frequency of slPSCs was decreased as compared with 3 μmol/L Oxo-M in the above 16 neurons. The slPSCs were completely abolished by 2 μmol/L strychnine. Atropine, the specific mAChR antagonist, completely blocked the effect of Oxo-M on the frequency of sIPSCs. In 9 additional lamina Ⅱ neurons, 1-10 μmol/L oxo-M failed to alter significantly the frequency and amplitude of glycinergic mIPSCs. Conclusion Activation of mAChRs in the somatodendritic site of glycinergic interneurous increases the synaptic glycine input to spinal dorsal horn neurons, but not in a dose-dependent manner.
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Objective To study the relationship of levels of acetylcholine receptor antibody (AChRAb) and thyroid antibodies in patients with myasthenia gravis (MG) and thyroidism. Methods Thyroid function of FT3, FT4 and TSH, and thyroid antibodies including TSH receptor antibody ( TRAb), thyroid globulin antibody (TGAb) and thyroid microsome antibody (TMAb) were detected in 100 patients with MG and 100 healthy controls. Among them, 32 patients were further tested for AChRAb. The relationship between AChRAb and each of TRAb, TGAb and TMAb was analyzed along with their relevant clinical characteristics. Results Of 100 patients with MG, 12 cases ( 12% ) were hyperthyroidism and 4 cases (4%) were hypothyroidism, and 71 cases (71%) were thyroid antibodies positive. The percent of thyroid antibodies positive cases was significantly higher than that of thyroidism cases (χ2=4. 788, P < 0. 05 ). Analysis on AChRAb and TRAb in 32 AChRAb tested cases demonstrated a linear correlation (r= 0. 609, P = 0. 0002). Conclusions The incidence of thyroid antibody positive in MG cases is significantly higher than incidence of hyperthyroidism and hypothyroidism in MG. AChRAb and TRAb has a linear correlation.
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Objective:To observe the effects of pretreatment and treatment with electroacupuncture on the abilitv of learning and memory in rats with ischemia-reperfusion injury,and to provide the research basis for preventing and treating the disorder of leaming and memory in patients with apoplectic sequelae.Methods:Seventy-two SD rats,clean class,were randomly divided into sham operation group,model group,pretreatment group,and treatment group.The step-through latency and number of errors,nerve injury score,and the number of cholinoceotor in the affected hippocampus were recorded to analyze the effects of pretreatment and treatment with electroacupuncture on the ability of learning and memory in rats with ischemia-reperfusion iniury.Results:1)The rats with ischemia had various signs of nerve injury.Compared with that in the sham operation rats,the nerve injury score in the model rats was lower,the step-through latency and number of errors were increased,and the content of special mAchR was decreased(P＜0.05):2)Electroacupuncture could decrease the nerve injury score of the model rats.Compared with those in the model group,the step-through latency and number of errors all had significant difierence in the pretreatment and treatment groups(P＜0.05);3)Compared with that in the model group.the content of mAchR was increased in the pretreatment group(P＜0.05),and increased a little in the treatment group.Conclusion:Pretreatment and treatment with electroacupuncture can prolong step-through latency,and induce number of errors.Electroacupuncture pretreatment can increase the content of mAchR induced by ischemia-reperfusion injury,to improve the ability of learning and memory.Electroacupuncture pretreatment plays an important role in preventing the disorder of learning and memory in patients with ischemic cerebrovascular disease.
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Objective To explore the roles of autoantibodies against ?1 adrenoceptor(?1-receptor)and M2 cholinergic receptor(M2-receptor)in patients with chronic renal insufficiency.Methods The epitopes of the second extracellular loop of ?1 receptor and M2 receptor were synthesized and used respectively to detect the sera autoantibodies against ?1 receptor and M2 receptor by enzyme linked immunosorbent assay(ELISA) in 76 patients with chronic renal insufficiency,60 cases with hypertension and 40 healthy controls.Results In patients with chronic renal insufficiency,the positive rates of the autoantibodies against ?1-receptor and M2-receptor were 56.7% and 38.1% respectively,which were much higher than those of patients with hypertension(18.3% and 11.7%) and higher than those of healthy controls(17.5% and 15.0%)(all P
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Objective To investigate the role of ?7nAChR in the pathogenesis of Alzheimer's disease(AD)through exploring the relationship between ?7nAChR and A?_(1-42) in AD brains.Methods The accumulation of ?7nAChR and the possible relationship between ?7nAChR and A?_(1-42) were observed in 3 clinically and pathologically confirmed AD brains by immunohistochemistry. 3 normal brains were set as controls.Results Respective staining of anti-?7nAChR and anti-A?_(1-42) showed that the abnormal accumulation of ?7nAChR existed in AD brains. The main location was at hippocampus and temporal cortex which was just in accordance with senile plaque consisted mainly of A?_(1-42). The major part of ?7nAChR was located extra-cellular and within senile plaque from the view of morphology. No accumulation of ?7nAChR existed in normal brains. Co-staining of anti-?7nAChR and anti-A?_(1-42) further showed that ?7nAChR and A?_(1-42) could accumulate together in senile plaque of AD brain. The average rate of positive co-staining in hippocampus, temporal lobe and frontal lobe is 57.8%, 51.0% and 21.8% respectively. The accumulation of ?7nAChR in hippocampus and temporal lobe seems much than that in the frontal lobe. Conclusion ?7nAChR may combine with A?_(1-42) in AD brains. It is suggested that the combination should destroy the ?7nAChR receptor, block the receptor or mediate the injury of cholinergic neurons with the result of recognition and memory impairment and that ?7nAChR might play an important role in the pathogenesis of Alzheimer's disease.
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AIM: To further investigate the immunologic mechanism of myasthenia gravis(MG). METHODS: Acetylcholine receptor antibodies(AchRab) and presynaptic membrane antibodies (PsMab) was determined by ELISA in 285 cases of MG patients. Tumor necrosis factor- alpha(TNF-?) and RBC-C3b receptor rosette rate(RBC-C3bRR)and RBC-IC rosette rate (RBC-ICR)was determined in 202 patients with MG. Furthermore, the peripheral blood lymphocyte subsets was examined in 104 cases MG patients. RESULTS: The positive rates of the AchRab and PsMab in MG were very significantly higher than that of control.The positive rate of PsMab in patients with negative AchRab was very significantly higher than that of patients with the positive AchRab.In 202 MG patients, the TNF-? was significantly higher, but the RBC-C3bRR was significantly lower than those of control, while the RBC-ICR has no significant change. CONCLUSION: MG is an autoimmune disease with damaged postsynaptic membrane by the AchRab, and some patients with both the AchRab and PsMab could manifest disfunction in the postsynaptic and presynaptic membrane. While the patients who just has the PsMab maybe damaged only in the presynaptic membrane. Other body fluid immune or/and cell immune mechanism may be involved in MG patients without AchRab and PsMab. [
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Objective To observe the time profile of the changes of mRNA of ? and ? subunit of acetylcholine receptor (AChR) in skeletal muscle and the level of calcitonin gene related peptide (CGRP) in spinal motoneuron after upper motoneuron injury. Method The spinal cord of adult male Wistar rats was transected on the lower thoracic segment. The spinal cords below the transection level and soleus muscles were sampled 0,1,2,4,7 and 14 days after surgery, respectively, to detect the levels of mRNA of ? and ? subunit of acetylcholine receptor in soleus muscle using Northern blot method,and CGRP level in spinal motoneuron using radioimmunoassay.Results The levels of mRNA of ? and ? subunit of acetylcholine receptor siginificantly increased after surgery, but the level of mRNA of ? subunit increased earlier and higher than ? subunit. The level of CGRP in spinal motoneuron markedly reduced after surgery, was maintained at 50 80% of normal level since the 2nd day after surgery. Conclusions The levels of AChR ? and ? subunit in skeletal muscle significantly increase after upper motoneuron injury, the expression of which CGRP may regulate.