Novel dose-dependent alterations in excitatory GABA during embryonic development associated with lead (Pb) neurotoxicity

Lead (Pb) is a heavy metal that is toxic to numerous physiological processes. Its use in industrial applications is widespread and results in an increased risk of human environmental exposure. The central nervous system (CNS) is most sensitive to Pb exposure during early development due to rapid cell proliferation and migration, axonal growth, and synaptogenesis. One of the key components of CNS development is the Gamma-aminobutyric acid (GABA)-ergic system. GABA is the primary inhibitory neurotransmitter in the adult brain. However, during development GABA acts as an excitatory neurotrophic factor which contributes to these cellular processes. Multiple studies report effects of Pb on GABA in the mature brain; however, little is known regarding the adverse effects of Pb exposure on the GABAergic system during embryonic development. To characterize the effects of Pb on the GABAergic system during development, zebrafish embryos were exposed to 10, 50, or 100 ppb Pb or a control treatment. Tissue up-take, gross morphological alterations, gene expression, and neurotransmitter levels were analyzed. Analysis revealed that alterations in gene expression throughout the GABAergic system and GABA levels were dose and developmental time point specific. These data provide a framework for further analysis of the effects of Pb on the GABAergic system during the excitatory phase and as GABA transitions to an inhibitory neurotransmitter during development.     

On-line measurement of cell impedance during charging and discharging process

The paper describes the principles of cell impedance measurement method, which, unlike other impedance techniques used for cell examination, operates on-line. In order to present the capabilities of the proposed method, experimental results are shown. The conducted experiment was cyclic charging and discharging of the lead cell in 4.8 M H₂SO₄ with simultaneous impedance measurement. The variations of electric parameters, obtained as the result of impedance spectrums analysis, are highly correlated with the state of charge, as well as with the number of cycles.     

经静脉置入埋藏式心律转复除颤器的临床随访

对 1 0例经静脉置入埋藏式心律转复除颤器 (ICD)的恶性室性心律失常患者进行随访 ,观察ICD的治疗效果。男 6例、女 4例 ,年龄 5 6.9± 1 3.3( 30～ 70 )岁。基础心脏病为冠心病 6例、心肌病 3例、先天性长QT综合征 1例。所有患者均经临床证实有室性心动过速或 /和心室颤动。ICD具有多项治疗及信息储存记忆功能。随访时通过体外程控仪调出ICD储存的资料进行分析。结果 :随访 2 9.3± 2 0 .4( 8～ 64)个月 ,7例患者分别接受了抗心动过速起搏、电转复及电除颤治疗。 2例患者因窦性心动过速、阵发性心房颤动 ,ICD给予误治疗。 1例患者术后 3年发生电极断裂。结论 :常规进行随访和设定合适的诊断和治疗参数 ,对保证ICD及时有效的治疗至关重要。     

血管内反推力牵引术拔除感染性起搏电极导管

应用血管内反推力牵引术，经上腔静脉途径对９例病人的１４根感染性起搏电极导管进行拔除。１０根（７１．４％）电极导管被完全拔除，不完全拔除２根（１４．３％）。拔除失败的２根（１例）起搏电极导管经外科开胸术取出。平均随访９个月，感染被控制。提示血管内反推力牵引术是拔除感染性起搏电极导管和治疗起搏器植入术后顽固性感染的有效方法。     

葛兰心宁软胶囊治疗冠状动脉粥样硬化性心脏病不稳定型心绞痛临床观察

目的：观察葛兰心宁软胶囊治疗冠状动脉粥样硬化性心脏病不稳定型心绞痛患者的临床疗效。方法：将87例冠状动脉粥样硬化性心脏病不稳定型心绞痛患者,在常规治疗的基础上加用葛兰心宁软胶囊,每次2粒（1.16 g）,每日3次,4周后观察临床疗效。结果：87例患者中治愈47例,好转21例,未愈19例,有效率78.2%。结论：葛兰心宁软胶囊可明显缓解冠状动脉粥样硬化性心脏病不稳定心绞痛患者的临床症状,且不良反应小。     

Heat-assisted slurry sampling GFAAS method for determination of lead in food standard reference materials

A valid method based on heat-assisted slurry sampling graphic furnace atomic absorption spectrometry (HASS-GFAAS) was developed for the accurate determination of trace Pb in food standard reference materials (SRMs). The HASS technique significantly improved Pb recovery and precision compared to conventional slurry sampling techniques. The optimized HASS procedure was performed as follows: first, the sample (particle size ≤ 150 μm) was diluted with 0.05% (v/v) Triton X-100 containing 2% HNO₃ and 1% H₂O₂ followed by heating for 20 min at 120 °C on a heating block. Next, the obtained slurry was sonicated in an autosampler cup, and finally, the slurry was introduced into a graphite tube and analyzed by the GFAAS with a Pb electrodeless discharge lamp (EDL). Calibration with aqueous standard solutions was used for Pb determination in food samples. The characteristic mass and limit of detection for Pb based on the integrated absorbance for a 2% (m/v) sample were 12 ± 0.6 pg and 0.003 mg kg⁻¹, respectively. The accuracy (95.1–102% recovery) and good precision (0.1–3.6%) of this procedure are illustrated by the results obtained for the 12 food reference materials. The proposed method is suitable for determination of trace Pb in solid food samples.     

A magnetic ion-imprinted polymer for lead(II) determination: A study on the adsorption of lead(II) by beverages

In this work a variety of beverage samples had been kept in a contaminated area to investigate their lead adsorption. To determine the adsorbed Pb(II), a novel magnetic lead ion-imprinted polymer, grafted onto Fe₃O₄ nanoparticles, was synthesized and used as a selective sorbent for the preconcentration of Pb(II) ions. The sorbent was characterized by different techniques. The synthesized sorbent was applied for highly accurate and selective determination of Pb(II) ions absorbed from polluted air in several beverages and results were compared. To validate the method, three certified reference materials were analyzed by the proposed method and the results showed that pre-concentrating by this sorbent and subsequent determination by flame atomic absorption spectroscopy is an accurate method for lead determination in beverage samples (recoveries higher than 95%). The limits of detection and the relative standard deviations were less than 1.7 μg kg⁻¹ and 4.1%, respectively. The sorption capacity of this new sorbent was 51.8 mg g⁻¹. Finally, this method was used for the determination of Pb(II) ions in polluted beverage samples, and the results revealed that under equal conditions, coffee exhibits more tendency to adsorb Pb(II) ions.     

纳米铅和常规铅暴露对仔鼠海马及皮质氧化损伤的比较研究

目的比较纳米铅和常规铅暴露对生长发育期仔鼠海马及皮质的氧化损伤作用。方法将30只健康妊娠SPF级SD大鼠随机分为3组,分别为对照(生理盐水)组、纳米铅(10 mg/kg)组和常规铅(100 mg/kg)组,每组10只。采用经口灌胃方式进行染毒,自母鼠妊娠至仔鼠断乳(PND21)。记录仔鼠的出牙时间、睁眼时间、翻正反射时间、爬行时间、张耳时间、断崖回避时间,采用Morris水迷宫对PND21仔鼠进行学习记忆能力测试,分别于PND1、PND21检测仔鼠海马和皮质中的铅、活性氧(ROS)、蛋白质糖基化终产物(AGEs)含量和抑制羟自由基能力。结果与对照组比较,纳米铅及常规铅暴露后仔鼠翻正反射时间、爬行时间及张耳时间延长,学习记忆能力降低;皮质、海马中铅、ROS和AGEs含量增高,而抑制羟自由基能力降低,差异均有统计学意义(P0.05)。与常规铅组比较,纳米铅组PND21仔鼠皮质和海马中ROS水平均升高,PND1时纳米铅组仔鼠海马抑制羟自由基能力下降,纳米铅暴露组PND21仔鼠海马和皮质中AGEs含量增高,差异均有统计学意义(P0.05)。结论纳米铅和常规铅染毒可导致仔鼠生长发育期迟缓及皮质、海马的氧化应激,且随着染毒时间延长,纳米铅暴露致仔鼠皮质和海马氧化损伤程度高于常规铅暴露,这可能与纳米材料的特性有关。     

Single-step transvenous extraction of a passive fixation lead with delayed perforation of the right ventricle

Delayed pacemaker lead perforation is a very rare complicationand most of the published reports involve active fixation leads.The authors report an uneventful transvenous extraction of apassive fixation lead, which had a delayed perforation of theright ventricle, disclosed two months after pacemaker implantation.