运动训练对小鼠脑局灶缺血后大脑皮质胆碱能纤维密度的作用

目的研究运动训练对小鼠大脑中动脉闭塞(middlecerebralarteryocclusion,MCAO)后大脑皮质胆碱能纤维密度的影响,探讨适度运动对脑损伤后功能恢复的作用。方法30只雄性C57BL/6J鼠用Bederson的方法,建立MCAO模型。将MCAO后小鼠随机分为运动组和对照组,每组均15只鼠。运动组:跑笼训练共90d;对照组:跑笼固定不转。分别在MCAO后15,45,90d,观察两组小鼠大脑皮质胆碱能纤维密度改变。结果MCAO后15d,两组皮质III缺血侧、正常侧胆碱能纤维密度差异无显著性意义(t=0.9,0.6,P>0.05)V层运动组犤缺血侧(121±15)个,正常侧为(170±18)个犦比对照组犤(171±15)个,(119±13)个犦显著增高(t=3.4,4.6,P<0.05)。45d,运动组在皮质III犤(241±23)个犦、V层犤(223±12)个犦正常侧胆碱能纤维密度比对照组犤(173±15)个,(181±8)个犦显著增高(t=3.5,3.3,P<0.05),缺血侧无明显差异(t=0.9,1.1,P>0.05)。90d,运动组与对照组比较,在正常侧及缺血侧皮质Ⅲ、V层纤维密度均增高(缺血侧t值分别为3.7,3.8,P<0.05;正常侧t=9.5,9.4,P<0.05)。结论运动训练对小鼠MCAO后大脑缺血侧和正常侧皮层胆碱能纤维的轴突发芽及再生有一定促进作用。     

短期和长期训练对小鼠脑局灶缺血后大脑皮质胆碱能纤维密度的影响

目的:观察小鼠脑局灶缺血后短期和长期运动训练对大脑皮质胆碱能纤维密度的影响。方法:取30只雄性C57BL/6J鼠用Bederson等的方法,建立大脑中动脉闭塞模型,造模后随机分为运动组和对照组各15只。运动组:将小鼠放进直径为17cm的带轴承转笼,让其主动跑笼,第1天跑10min,以后每天增加10min,直至1h/d,共训练90d,每周一到六训练,周日休息;对照组:跑笼固定不转。两组分别在造模后15,90d随机取5只处死,观察两组小鼠大脑皮质Ⅲ,Ⅴ层胆碱能阳性纤维密度(以0.01mm2内阳性纤维与测试线的交点数表示)改变。结果:①造模后15d,两组小鼠缺血侧和正常侧脑皮质Ⅲ层胆碱能阳性纤维密度差异不显著(P>0.05);运动组小鼠脑皮质Ⅴ层缺血侧和正常侧胆碱能阳性纤维密度均高于对照组犤(176.6±15.3),(123.8±15.4)个;(189.8±17.9),(118.6±13.4)个,P<0.05犦。②造模后90d,无论在正常侧还是在缺血侧,无论在脑皮质Ⅲ层还是Ⅴ层,运动组小鼠胆碱能阳性纤维密度均高于对照组(P<0.05)。③脑皮质Ⅲ层、Ⅴ层运动组缺血侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高(P<0.05),而在对照组两者差异不显著(P>0.05)。脑皮质Ⅲ层、Ⅴ层运动组正常侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高(P<0.05),而在对照组两者差异不显著(P>0.05)。结论:长期运动训练比短期训练能提高小鼠大脑中动脉闭塞后胆碱能纤维的密度,对大脑两侧均有一定影响。     

短期和长期训练对小鼠脑局灶缺血后大脑皮质胆碱能纤维密度的影响

目的：观察小鼠脑局灶缺血后短期和长期运动训练对大脑皮质胆碱能纤维密度的影响。方法：取30只雄性C57BL／6J鼠用Bederson等的方法，建立大脑中动脉闭塞模型，造模后随机分为运动组和对照组各15只。运动组：将小鼠放进直径为17cm的带轴承转笼，让其主动跑笼，第1天跑10min，以后每天增加10min，直至1h／d，共训练90d，每周一到六训练，周日休息；对照组：跑笼固定不转。两组分别在造模后15，90d随机取5只处死，观察两组小鼠大脑皮质Ⅲ，Ⅴ层胆碱能阳性纤维密度（以0．01mm^2内阳性纤维与测试线的交点数表示）改变。结果：①造模后15d，两组小鼠缺血侧和正常侧脑皮质Ⅲ层胆碱能阳性纤维密度差异不显著（P〉0．05）；运动组小鼠脑皮质Ⅴ层缺血侧和正常侧胆碱能阳性纤维密度均高于对照组[（176．6&;#177;15.3），（123．8&;#177;15．4）个；（189．8&;#177;17．9），（118．6&;#177;13．4）个．P〈0．05]。②造模后90d，无论在正常侧还是在缺血侧，无论在脑皮质Ⅲ层还是Ⅴ层，运动组小鼠胆碱能阳性纤维密度均高于对照组（P〈0．05）。③脑皮质Ⅲ层、Ⅴ层运动组缺血侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高（P〈0．05），而在对照组两者差异不显著（P〉0．05）。脑皮质Ⅲ层、Ⅴ层运动组正常侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高（P〈0．05），而在对照组两者差异不显著（P〉0．05）。结论：长期运动训练比短期训练能提高小鼠大脑中动脉闭塞后胆碱能纤维的密度，对大脑两侧均有一定影响。     

运动训练对小鼠脑局灶缺血后大脑皮质胆碱能纤维密度的作用

目的 研究运动训练对小鼠大脑中动脉闭塞（middle cercbral artery occlusion，MCAO)后大脑皮质胆碱能纤维密度的影响，探讨适度运动对脑损伤后功能恢复的作用。方法 30只雄性C547BL/6J鼠用Bederson的方法，建立MCAO模型。将MCAO后小鼠随机分为运动组和对照组，每组均15只鼠。运动组：跑笼训练共90d；对照组：跑笼固定不转。分别在MCAO后15，45，90d，观察两组小鼠大脑皮质胆碱能纤维密度改变。结果 MCAO后15d，两组皮质Ⅲ缺血侧、正常侧胆碱能纤维密度差异无显著性意义(t=0．9，0．6，P&;gt;0．05)V层运动组[缺血侧(121&;#177;15)个，正常侧为(170&;#177;18)个]比对照组[(171&;#177;15)个，(119&;#177;13)个]显著增高(t=3．4,4．6，P&;lt;0．05)。45d，运动组在皮质Ⅲ[(241&;#177;23)个]、V层[(223&;#177;12)个]正常侧胆碱能纤维密度比对照组[(173&;#177;15)个，(181&;#177;8)个]显著增高(t=3．5，3．3，P&;lt;0．05)，缺血饲无明显差异(t=0．9，1．l，P&;gt;0．05)。90d，运动组与对照组比较，在正常侧及缺血侧皮质量、V层纤维密度均增高(缺血侧t值分别为3．7，3．8，P&;lt;0．05；正常侧t=9．5，9．4，P&;lt;0．05)。结论 运动训练对小鼠MCAO后大脑缺血侧和正常侧皮层胆碱能纤维的轴变发芽及再生有一定促进作用。     

运动训练对小鼠脑局灶缺血后大脑皮质一氧化氮合酶的影响

目的：研究运动训练对小鼠大脑中动脉闭塞（MCAO）后大脑皮质一氧化氮合酶（NOS）的影响。方法：30只雄性C57 BL/6J鼠用Bederson的方法，建立MCAO模型。将MCAO后小鼠随机分为运动组和对照组，每组均15只鼠。运动组：跑笼训练共90d；对照组：跑笼固定不转。分别在MCAO后15d、45d、90d，观察两组小鼠大脑皮质NOS数的改变。结果：MCAO后15d，两组皮质缺血侧、正常侧NOS阳性细胞数差异无显著性意义（t=2．1，0．2，P〉0．05）。45d，运动组比对照组在皮质正常侧NOS阳性细胞数显著增高（t=3．55，P〈0．05），缺血侧差异无显著性意义（t=0．26，P〉0．05）。90d，运动组与对照组比较，NOS阳性细胞计数在正常侧皮质均差异有显著性意义（P〈0．01），而缺血侧各组之间差异无显著性意义（P〉0．05）。结论：运动训练可增加小鼠MCAO后大脑正常侧皮层NOS阳性细胞的数量，对脑的可塑性有一定促讲作用.     

运动训练对卒中鼠平衡功能的影响

目的探讨跑笼运动是否对小鼠脑缺血后平衡功能有影响.方法雄性C57BL/6/J鼠59只,制成脑局灶缺血模型后,随机分运动组(n=28),跑笼90d,对照组(n=26)不运动.用修订Drucker方法进行平衡木试验.不同时间组间比较用Frideman检验,不同组间通过数比较用卡方检验.结果运动组与对照组相比MCAO后9Od,总时间在l、8、12mm宽度上缩短(P＜0.05);停留时间在1、2、8、12mm宽度上缩短,差异有显著性(P＜0.05);通过平衡本数量,无量著性差异(p＞0.05).结论长期的运动训练,促进了小鼠脑缺血后平衡功能的恢复.     

经颅电刺激加康复训练对脑缺血再灌大鼠功能恢复和微管相关蛋白-2的影响

目的:研究经颅电刺激加康复训练能否促进大鼠局部脑缺血再灌后的功能恢复并从神经可塑性角度探讨其机制。方法:线栓法制备SD大鼠短暂大脑中动脉缺血再灌模型(MCAO),术后随机分为电刺激加康复组(A)、康复组(B)、对照组(C)。A组给予经颅电刺激、滚笼和平衡木训练。B组仅给予滚笼和平衡木训练。分别于术后3、7、14和28天用走横木试验(BWT)进行运动功能评分,以及用免疫组化法检测微管相关蛋白-2(MAP-2)在梗死灶周围的免疫活性强度。结果:A组BWT评分在第7、14、28天优于B组和C组,差异有显著性意义(P<0.05);A组皮质缺血周边区MAP-2表达水平在第14、28天高于B组和C组,差异有显著性意义(P<0.05)。结论:经颅电刺激加康复训练能促进大鼠MCAO后肢体功能恢复,其机制可能与上调缺血灶周边MAP-2的表达有关,上述作用优于单独康复训练。     

运动及虚拟现实技术对小鼠生长发育及学习记忆行为的影响

目的:探讨虚拟现实技术与普通运动对小鼠生长发育及学习记忆行为的影响。方法:实验于2004-04/12在郑州大学医学院人体解剖学教研室进行。选择初断乳昆明种小鼠90只,随机数字表法分为跑台运动组、虚拟视觉组和正常对照组,每组30只。制定跑台运动组运动方案,训练12周,6d/周。跑台坡度为0°,第1周跑速3m/min,后每周递增1m/min。前4周1次/d,5min/次;中间4周2次/d,8min/次;后4周3次/d,10min/次。虚拟现实组进行视觉虚拟运动训练12周。周期安排同跑台运动组,将动物置于虚拟追逐环境(一侧显示黑色隧道样逃跑路线,对侧显示猫追赶画面,其余两侧显示周围背景)。对照组不进行任何运动训练。每训练4周后分别测量所有动物体质量。在训练结束后采用水迷宫方法检测跑台运动和虚拟现实训练小鼠的学习记忆行为。分别记录每只小鼠穿过水迷宫的时间和起步区到达目标区途中所犯错误次数,并计算每组小鼠穿越迷宫时间和穿越迷宫错误次数的构成比。结果:所有动物在实验中无脱落,全部进入结果分析。①跑台运动组与虚拟现实组小鼠训练4,8,12周后的体质量均显著高于正常对照组,差异均有显著性意义(P<0.05);跑台运动组与虚拟现实组之间差异无显著性意义。②跑台运动组与虚拟现实组小鼠穿越迷宫时间在0～9s,10～19s时间段的构成比显著高于正常对照组,差异均有显著性意义(P<0.05);在20～29s时间段的构成比显著低于正常对照组,差异均有显著性意义(P<0.05);跑台运动组在30～39s,>40s时间段的构成比显著低于正常对照组,差异均有显著性意义(P<0.05)。③跑台运动组与虚拟现实组小鼠穿越迷宫错误次数在0次错误的构成比显著高于正常对照组,差异均有显著性意义(P<0.05);在3,4次错误的构成比显著低于正常对照组,差异均有显著性意义(P<0.05)。结论:虚拟现实技术和普通运动同样可以促进小鼠的生长发育和智能发育。虚拟现实技术应用于现实训练具有可行性。     

跑笼训练与技巧性取食训练对脑梗死恢复期大鼠认知功能的影响

目的:比较脑梗死恢复期进行跑笼训练与技巧性取食训练对短暂性大脑中动脉闭塞(tMCAO)大鼠认知功能的影响。方法:50只雄性SD大鼠经利手筛选及技巧性取食预训练后,根据tMCAO术后神经功能评分将大鼠分为四组:技巧性取食组(n=7)、跑笼组(n=8)、对照组(n=6)、假手术组(n=6),于术后第1、14、28、42、56天进行改良神经功能缺损程度评分(mNSS),于术后第56天进行Morris水迷宫实验。结果:从第28天起技巧性取食组与跑笼组的mNSS均低于对照组(P0.001),且技巧性取食组低于跑笼组(P0.05)。水迷宫实验第1天、第2天和第4天跑笼组和对照组平均游泳路径长度较假手术组长(P0.05),第1天和第4天技巧性取食组的平均游泳路径长度较跑笼组和对照组短(P0.05);tMCAO各组穿越平台次数较假手术组少(P0.05),技巧性取食组及跑笼组穿越平台次数较对照组多(P0.05),且技巧性取食组较跑笼组多(P0.05)。结论:运动训练能够改善脑梗死恢复期大鼠的认知功能,且技巧性取食训练比跑笼训练效果更佳。     

Nox1和Nox4在小鼠局灶性脑缺血再灌注损伤中的表达

目的:观察Nox1和Nox4在小鼠局灶性脑缺血再灌注损伤后时间和空间的表达变化。方法:24只雄性昆明小鼠,随机分为大脑中动脉缺血(MCAO)组和假手术(Sham)组,MCAO组建立MCAO模型,Sham组不造成缺血,分别于再灌注后1、3 d检测脑组织梗死体积比,检测梗死侧Nox1和Nox4的mRNA表达,原位杂交组织学检测其表达部位,DCFH-DA法检测术后活性氧族产物(ROS)产量的变化。结果:MCAO组小鼠脑缺血再灌注第1、3天,梗死体积比分别为(13.60±1.23)%、(8.46±0.82)%,与Sham组比较,有显著性差异(P<0.001)。与Sham组比较,MCAO组梗死侧Nox1第1天表达升高(3.32±0.24)倍(P<0.001),第3天下降至接近正常;与非梗死侧相比,海马表达增高,皮质出现表达。Nox4第1天表达升高(2.21±0.16)倍(P<0.05),第3天表达升高(4.03±0.25)倍(P<0.001),主要表达于海马;与非梗死侧相比表达量增多,位置不变。与Sham组相比,MCAO组于术后第1天ROS产量增至(586.90±14.23)(P<0.05),术后第3天ROS产量为(461.00±15.71)(P<0.001)。结论:Nox1在缺血早期表达升高,可能与早期的病理损伤过程密切相关,Nox4在缺血后逐渐升高,可能与缺血再灌注后期的病理修复过程有较大的相关性。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.     

Evidence-Based Pain Management and Palliative Care in Issue Four for 2009 of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly. Issue 4 for 2009 contains 4027 complete reviews, 1906 protocols for reviews in production, and 11447 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 600,000 randomized controlled trials, and 12,200 cited papers in the Cochrane methodology register. The health technology assessment database contains over 7500 citations. This edition of the Library contains 90 new reviews, of which 19 have potential relevance for practitioners in pain and palliative medicine.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

Molecular characterization of virulence and antimicrobial resistance profile of Shigella species isolated from children with moderate to severe diarrhea in northeastern Brazil

Molecular characterization of virulence and antimicrobial resistance profiles were determined for Shigella species isolated from children with diarrhea in Fortaleza, Brazil. Fecal specimens were collected along with socioeconomic and clinical data from children with moderate to severe diarrhea requiring emergency care. Shigella spp. were isolated by standard microbiological techniques, and we developed 4 multiplex polymerase chain reaction assays to detect 16 virulence-related genes (VRGs). Antimicrobial susceptibility tests were performed using disk diffusion assays. S. flexneri and S. sonnei were the predominant serogroups. S. flexneri was associated with low monthly incomes; more severe disease; higher number of VRGs; and presence of pic, set, and sepA genes. The SepA gene was associated with more intense abdominal pain. S. flexneri was correlated with resistance to ampicillin and chloramphenicol, whereas S. sonnei was associated with resistance to azithromycin. Strains harboring higher numbers of VRGs were associated with resistance to more antimicrobials. We highlight the correlation between presence of S. flexneri and sepA, and increased virulence and suggest a link to socioeconomic change in northeastern Brazil. Additionally, antimicrobial resistance was associated with serogroup specificity in Shigella spp. and increased bacterial VRGs.