P2X受体对豚鼠胃窦环行肌自发性收缩运动的影响

目的:探讨P2X受体激动剂α,β-methylene ATP (α,β-MeATP)对豚鼠胃窦环行肌运动的影响及其离子通道机制.方法:采用EWG/B豚鼠,制备去黏膜胃窦环行肌条(10×1.5 mm),并将其固定于恒温灌流槽内(37℃),用碳酸氢钠缓冲液连续灌流并通氧(950 mL/L O_2,50 mL/L CO_2).利用SMUP-E生物信号处理系统记录胃窦平滑肌自发性收缩活动,Ⅱ型胶原酶消化法分离豚鼠胃窦环行肌单细胞,传统全细胞膜片钳技术记录急性分离的胃窦平滑肌细胞膜电位和离子电流,包括钙激活钾电流、延迟整流型钾电流及电压依赖性钙电流.结果:嘌呤能P2X受体激动剂α,β-MeATP明显抑制豚鼠胃窦环行肌自发性收缩,并有明显的量效倚赖关系:5,10,20,40,100μmol/Lα,β-MeATP作用下,环行肌收缩幅度分别由对照组的100%下降到90%±2%.81%±4%,68%±4%,59%±7%和29%±4%(P<0.05).用神经阻断剂Tetrodotoxin (TTX)预处理后,α,β-MeATP对胃窦环行肌自发性收缩的抑制作用仍不受影响;在传统全细胞膜片钳电流钳模式下,500μmol/Lα,β-MeATP不影响细胞膜电位,也对两种外向钾电流,即延迟整流型钾电流和钙激活钾电流没有影响;不同浓度的α,β-MeATP对电压依赖性钙电流没有影响.结论:P2X受体激动剂抑制豚鼠胃窦环行肌自发性收缩,其作用机制不依赖内在神经,也不依赖细胞膜离子通道以及膜电位改变.     

Prophylaxis with human serum butyrylcholinesterase protects guinea pigs exposed to multiple lethal doses of soman or VX

Human serum butyrylcholinesterase (Hu BChE) is currently under advanced development as a bioscavenger for the prophylaxis of organophosphorus (OP) nerve agent toxicity in humans. It is estimated that a dose of 200 mg will be required to protect a human against 2 × LD₅₀ of soman. To provide data for initiating an investigational new drug application for the use of this enzyme as a bioscavenger in humans, we purified enzyme from Cohn fraction IV-4 paste and initiated safety and efficacy evaluations in mice, guinea pigs, and non-human primates. In mice, we demonstrated that a single dose of enzyme that is 30 times the therapeutic dose circulated in blood for at least four days and did not cause any clinical pathology in these animals. In this study, we report the results of safety and efficacy evaluations conducted in guinea pigs. Various doses of Hu BChE delivered by i.m. injections peaked at ∼24 h and had a mean residence time of 78–103 h. Hu BChE did not exhibit any toxicity in guinea pigs as measured by general observation, serum chemistry, hematology, and gross and histological tissue changes. Efficacy evaluations showed that Hu BChE protected guinea pigs from an exposure of 5.5 × LD₅₀ of soman or 8 × LD₅₀ of VX. These results provide convincing data for the development of Hu BChE as a bioscavenger that can protect humans against all OP nerve agents.     

祖师麻止痛喷雾剂对豚鼠的长期毒性研究

目的:观察祖师麻止痛喷雾剂对豚鼠的长期毒性,为临床安全用药提供依据。方法:将50只豚鼠随机分为空白对照组、高剂量完整皮肤组、高剂量破损皮肤组、低剂量完整皮肤组、低剂量破损皮肤组,连续给药4周。随时观察记录其一般情况,用药后做血液学及血液生化指标检查,计算脏器系数并进行组织病理学检查。结果:祖师麻止痛喷雾剂各剂量组未见毒性反应,与空白对照组比较差异均无统计学意义(P>0.05),停药后也未见药物延迟性毒性反应。结论:长期给予豚鼠祖师麻止痛喷雾剂无明显毒性,推论临床拟用剂量安全。     

高频听力损失对豚鼠低频区时间分辨率的影响

目的 构建豚鼠高频听力损失模型,通过听觉惊跳反射前抑制方法观察高频听力损失后,低频区时间分辨率的变化.方法 采用简单随机法将豚鼠分为实验组(6只)和对照组(4只),实验组暴露于声压级110 dB的12 kHz纯音下30 h,建立8 kHz以上听力损失模型,对照组未作处理.于噪声暴露前、暴露后2周、4周、6周及8周等五个时间点进行听觉惊跳反射前抑制试验和听觉脑干反应(ABR)测试.在听觉惊跳反射前抑制试验中,选用0.5～2 kHz,0.5～4 kHz和0.5～8 kHz三种背景噪音频率(均在听敏度正常的低频段)来观察低频区时间分辨率的变化.结果 噪声暴露后2周,实验组动物呈现8 kHz以上频率陡降型高频听力损失,在16 kHz、32 kHz和48 kHz频率均有平均55 dB的阈移,与声暴露前相比差异均有统计学意义(P值均＜0.05),而1 kHz、2 kHz、4 kHz和8 kHz在噪音暴露前后差异均无统计学意义(P值均＞0.05).在8周的实验期内,实验组高频听力损失仍然存在.对照组豚鼠所有频率的听敏度在实验期内各个时间点差异均无统计学意义(P值均＞0.05).实验组在8 kHz的背景噪音下,声暴露后第2周抑制能力减弱,与暴露前相比差异具有统计学意义(P=0.036),其余时间点和暴露前相比差异无统计学意义(P值均＞0.05);在4 kHz的背景噪音下,声暴露后所有时间点的抑制能力与暴露前相比差异均无统计学意义(P值均＞0.05);在2 kHz的背景噪音下,声暴露后第6周、第8周抑制能力降低,与暴露前相比差异具有统计学意义(P值均＜0.05).结论 高频听力损失可降低正常低频区的时间分辨率.

Abstract：

Objective To constitute the animal model of high frequency hearing loss and observer the temporal processing abilities of low frequency regions using prepulse inhibition of auditory startle response (gap-PPI).Methods Ten guinea pigs were randomly grouped into two groups: the high frequency hearing loss group with six guinea pigs and the control group with four guinea pigs.The former group was exposed to 12 kHz tone at 110 dB SPL for 30 hours to establish the high frequency hearing loss above 8 kHz and the latter group received no stimuations.Before and two,four,six and eight weeks after noise exposure,gapPPI and auditory brainstem response (ABR) were recorded in both groups.In the gap-PPI experiment,three different background noises as 0.5-2 kHz,0.5-4 kHz and 0.5-8 kHz were applied to test the temporal gap.Results High frequency hearing loss above 8 kHz was shown two weeks after noise exposure.The averaged ABR thresholds of 16 kHz,32 kHz and 48 kHz were elevated about 55 dB and shown statistical significance compared to those before exposure (P ＜ 0.05＝.No significant difference of ABR thresholds were shown between 1 kHz,2 kHz,4 kHz and 8kHz before and after noise exposure(P ＞0.05).In the control group,the ABR thresholds remained stable during experiment.In the gap-PPI test,two weeks after noise exposure of 8 kHz,the experiment group showed attenuated inhibition ability and recovered gradually four weeks after noise exposure.No statistical differences of inhibition ability at time points of two,four,six and eight weeks after noise exposure of 4 kHz were detected when compared with that of pre-exposure.Under the background noise of 2 kHz,the inhibition ability attenuated and reached statistical significance at 6-8 weeks after noise exposure.Conclusion The high frequency hearing loss might induce an impairment of the temporal processing in the low frequency region.     

模拟失重和噪声复合因素对豚鼠内耳淋巴液容积的影响

目的探讨模拟失重和噪声复合因素对豚鼠内耳淋巴液容积的影响。方法健康豚鼠24只随机分为单纯失重组12只、单纯噪声组6只、失重+噪声组6只,分别测试实验前、实验5天及实验结束后3天听性脑干诱发电位(ABR)阈值及内耳MRI扫描,并用自制专用软件对内耳淋巴液容积进行计算。结果单纯噪声组实验前后内耳容积无差异(P>0.05);单纯失重组实验5天与实验前、实验结束后3天与实验5天相比有显著性差异(P<0.01),实验结束后3天与实验前相比无明显差异(P>0.05);失重+稳态噪声组实验5天及实验结束后3天豚鼠内耳容积较实验前明显增大(P<0.01),实验5天与实验结束后3天豚鼠内耳容积无显著差异(P>0.05)。结论失重环境可使豚鼠内耳淋巴液容积变大,但是短期单纯失重环境豚鼠内耳淋巴液容积变化可恢复,失重加噪声复合因素会加重内耳淋巴液容积变化,且实验后3天后内耳淋巴液容积无恢复。     

丹龙定喘汤对哮喘豚鼠气道重塑的作用及机制研究

目的初步探析丹龙定喘汤对哮喘豚鼠气道重塑的作用及机制。方法选取健康雌性豚鼠24只,按体质量分层随机分为4组：空白对照组、模型对照组、地塞米松组、丹龙定喘汤组,每组6只。采用卵蛋白致敏法建立豚鼠哮喘气道重塑模型,以丹龙定喘汤干预,并以地塞米松做对照药物,治疗1个月后分别检测气道重塑的程度及豚鼠肺组织中转化生长因子β1（TGF-β1）含量。结果 （1）模型对照组豚鼠肺支气管管壁和平滑肌层明显增厚,与空白对照组相比差异有统计学意义（P〈0.05）;丹龙定喘汤组气道壁厚度减轻,与模型对照组相比差异有统计学意义（P〈0.05）,与地塞米松组相比,差异无统计学意义（P〉0.05）。（2）模型对照组豚鼠肺组织中的TGF-β1含量明显增加,与空白对照组相比,差异有统计学意义（P〈0.05）;丹龙定喘汤组TGF-β1含量减少,与模型对照组相比差异有统计学意义（P〈0.05）,与地塞米松组相比差异无统计学意义（P〉0.05）。结论丹龙定喘汤对哮喘豚鼠气道重塑有一定抑制作用,其机制可能是通过下调哮喘豚鼠肺组织中的TGF-β1水平,抑制气道平滑肌细胞及细胞外基质的增殖而阻断气道重塑的进程。     

实验性近视眼巩膜成纤维细胞力学特性的动态变化

目的 研究豚鼠镜片诱导型近视眼(LIM)前部及后极部巩膜成纤维细胞的力学特性的动态变化.方法 实验研究.取2周龄豚鼠30只,分为A、B、C 三组,每组10只,用离焦的方法制备凹透镜诱导近视(LIM)动物模型,对侧眼为f自身对照眼(SC眼),再随机选取5只(10眼)正常2周龄豚鼠不作任何干预,作为正常对照组(NC组),将A、B、C 三组分别造模6、15、30 d后,用组织块培养法培养每组豚鼠前部及后极部巩膜成纤维细胞,,并传2代.利用细胞微管吸吮的疗法测定各组巩膜成纤维细胞的平衡杨氏模量和细胞表观黏性.各组数据结果计算记录为均数±标准误((x)±s)和等级资料表示,对照组与实验组间差异分别行配对t检验,组间差异行完全随机单因素方差分析.结果 LIM各组间的细胞力学特性比较,及与SC组比较,发现无论是平衡杨氏模量还是细胞表观黏性,LIM组前部于诱导6 d[(0.2252±0.0836)kPa,μ=(1.3119±0.4862)kPa.s]、15 d[(0.2373±0.0903)kPa,( 1.3583±0.5652)kPa.s]时与SC组[(0.2220±0.0593)kPa,( 1.4122±0.4326)kPa]比较无明显变化,诱导30 d[ (0.3874±0.0965)kPa,( 2.6278±0.8063 )kPa.s]时与6、15 d及SC组比较均增高,其差异有统计学意义(P＜0.05);LIM组后极部于诱导6 d [(0.3432± 0.0786)kPa,( 1.9237±0.5203 )kPa.s]时与SC组[(0.2283±0.059 )kPa,μ=1.3248±0.3535)kPa.s]比较无明显变化,但诱导15 d [(0.4797±0.1241)kPa,(3.3221±0.7179)kPa.s]、30 d[(0.5663±0.1127)kPa,[4.6264±1.2205) kPa.s]时与6 d组、SC组比较均增高,其差异有统计学意义(P＜0.05).结论 LIM组前部及后极部巩膜成纤维细胞的平衡杨氏模量、黏弹性参数分别在诱导30 d和诱导15 d后有明显升高,即有“硬化”现象.     

用放射免疫沉淀试验检查几种感染鼠疫菌的试验动物F1抗体

用RIP对感染鼠疫菌的黄胸鼠等5种鼠类血清和脏器进行测定,结果表明脏器可检出F1体:一般情况,检出菌及IHA阳性标本难于查出抗体,而检出F1抗体者又难于培养出鼠疫菌:血清抗体阳性率及滴度与鼠疫菌攻击量无相关关系而与感染率有一定关系。     

Viruses associated with influenza‐like‐illnesses in Papua New Guinea, 2010

Influenza‐like‐illness can be caused by a wide range of respiratory viruses. The etiology of influenza‐like‐illness in developing countries such as Papua New Guinea is poorly understood. The etiological agents associated with influenza‐like‐illness were investigated retrospectively for 300 nasopharyngeal swabs received by the Papua New Guinea National Influenza Centre in 2010. Real‐time PCR/RT‐PCR methods were used for the detection of 13 respiratory viruses. Patients with influenza‐like‐illness were identified according to the World Health Organization case definition: sudden onset of fever (>38°C), with cough and/or sore throat, in the absence of other diagnoses. At least one viral respiratory pathogen was detected in 66.3% of the samples tested. Rhinoviruses (17.0%), influenza A (16.7%), and influenza B (12.7%) were the pathogens detected most frequently. Children <5 years of age presented with a significantly higher rate of at least one viral pathogen and a significantly higher rate of co‐infections with multiple viruses, when compared to all other patients >5 years of age. Influenza B, adenovirus, and respiratory syncytial virus were all detected at significantly higher rates in children <5 years of age. This study confirmed that multiple respiratory viruses are circulating and contributing to the presentation of influenza‐like‐illness in Papua New Guinea. J. Med. Virol. 86:899–904, 2014. © 2013 Wiley Periodicals, Inc.