Cobalt-dependent potentiation of net inward current density in Helix aspersa neurons.

A low concentration of transition metal ions Co2+ and Ni2+ increases the inward current density in neurons from the land snail Helix aspersa. The currents were measured using a single electrode voltage-clamp/internal perfusion method under conditions in which the external Na+ was replaced by Tris+, the predominant external current carrying cation was Ca2+, and the internal perfusate contained 120 mM Cs+/0 K+; 30 mM tetraethylammonium (TEA) was added externally to block K+ current. In the presence of Co2+ (3 mM) or Ni2+ (0.5 mM) inward Ca2+ currents were stimulated normally by voltage-dependent activation of Ca2+ channels. There was a 5-10% decrease in the rate of rise of the inward current. The principal effect of Co2+ and Ni2+ in increasing the current density seems to be a decrease in the rate at which the inward currents decline during a depolarizing voltage pulse. The results may be due to a decrease in a voltage-dependent or Ca(2+)-dependent outward current and/or an inhibition of Ca2+ channel inactivation. Outward current under these conditions (zero internal K+) was significant and most likely due to Cs+ efflux through the voltage-activated or Ca(2+)-activated nonspecific cation channels. Co2+ is an extremely effective blocker of this outward current. These results are not an artifact of internal perfusion or the special ionic conditions. Intracellular recording of unperfused neurons in normal Helix Ringer's solution showed that the Ca(2+)-dependent action potential duration was increased significantly by low concentrations of Co2+. This result is consistant with the Co(2+)-dependent increase in inward (depolarizing) current seen in voltage-clamp experiments.     

Decreased incidence of headache after accidental dural puncture in caesarean delivery patients receiving continuous postoperative intrathecal analgesia

To examine the effects of prolonged (> 24 h) intrathecal catheterization with the use of postoperative analgesia on the incidence of post–dural puncture headache (PDPH), charts of 45 obstetric patients who had accidental dural puncture following attempts at epidural block were reviewed retrospectively. Three groups were identified: Group I (n = 15) patients had a dural puncture on the first attempt at epidural block, but successful epidural block on a repeated attempt; Group II (n=17) patients had a dural puncture with immediate conversion to continuous spinal anaesthesia with catheterization lasting only for the duration of caesarean delivery; Group III (n= 13) patients had an immediate conversion to spinal anaesthesia and received post–caesarean section continuous intrathecal patient–controlled analgesia consisting of fentanyl 5 (ig'ml^-1 with bupivacaine 0.25 mg·ml^-1 and epinephrine 2 μg·ml^-1 with catheterization lasting >24 h. No parturient in group III developed a PDPH. This was substantially lower ( P < 0.009) than the 33% incidence for group I and the 47% incidence for group II. The incidence of a PDPH did not differ between group I and II. Similarly, there was no difference between group I and II with regard to requests for a blood patch. Patients receiving continuous intrathecal analgesia had excellent pain relief, could easily ambulate and none complained of pruritus, nausea, vomiting, sensory loss or weakness. In conclusion, indwelling spinal catheterization > 24 h with continuous intrathecal analgesia following accidental dural puncture in parturients may for some patients be a suitable method for providing PDPH prophylaxis and postoperative analgesia.     

Intra-Hisian Block Associated with Unusual Etiologies

One hundred and sixty-nine patients underwent electrophysiologic study for atrioventricular block. Forty-five (27%) had intra-Hisian block. Four of these 45 patients had unusual etiologies: rheumatoid arthritis, cysticercosis cellulosae, Behcet's disease, and Takayasu aorto-arteritis. Their clinical and electrophysiologic features are described in detail.     

Alternatives to Warfarin for Thromboembolism Prophylaxis in Nonrheumatic Atrial Fibrillation

A 45-year-old male with a preexcited QRS consistent with WPW syndrome was hospitalized for syncope. ECG monitoring revealed episodes of advanced atrioventricular block. An electrophysiologic study demonstrated right anteroseptal preexcitation and revealed an intermittent block in the accessory pathway and AV complete block causing long periods of spontaneous asystole. A DDD pacemaker was implanted without ablation of the accessory pathway.     

神经电生理检测对多灶性运动神经病诊断价值的初步研究

目的 探讨神经电生理检查在多灶性运动神经病(MMN)中的诊断价值。方法对16例MMN患者及16名健康对照进行运动神经传导速度和感觉神经传导速度检查，记录刺激引出的复合肌肉动作电位的波幅、波宽、面积、位相和时限，进行对比分析，判定是否有运动神经传导阻滞(CB)或暂时性离散(TD)，并有选择性地进行常规肌电图检查。结果16例患者均可见有一根以上运动神经或至少一根运动神经的一个以上部位出现CB或CD。其中13例双上肢正中神经，尺神经出现CB，3例以正中神经、尺神经的远端出现CB首发，随病情进展出现下肢腓深神经CB。仅有2例感觉神经传导速度稍有减慢，波幅略有降低。16例患者神经受累区域以下所支配肌肉肌电图检查见有神经源性损害。结论MMN是一种以远端神经受累为主的不对称性周围神经病，神经电生理检查对诊断和鉴别诊断．MMN起重要作用，CB是MMN的主要神经电生理表现。     

上肢手术气囊止血带个体充气压力的研究

目的探讨上肢手术时气囊止血带适宜的个体充气压力。方法对30例健康成年志愿者,按右上臂周径大小分为S组(≤25cm)、M组(26～30cm)和L组(＞30cm),用彩色多普勒超声血流显像仪分别测定肱动脉血流100%和50%阻断时气囊止血带充气压力值。以周径和测定值为依据确定充气压力：周径≤25cm者,充气压力为25 kPa(IkPa=7．5mm Hg),＞25cm者。以肢体周径(cm)作为个体充气压力(kPa)值,最大值≤40kPa。用上述方法应用于上肢手术150例,并观察术中创面止血效果和术后止血带副损伤发生情况。结果30例右侧肱动脉血流100%和50%阻断时气囊止血带充气压力参考值分别为：S组[(19．17±1．95)kPa,(?)±s,下同]和(11．50±1．98)kPa,M组(21．18±2．09)kPa和(13．45±1．86)kPa,L组(27．00±4．12)kPa和(16．43±1．13)kPa,各组阻断压力差异有统计学意义(P＜0．01)。手术应用150例中,上臂周径平均为(28．13±3．53)cm,气囊止血带充气压力平均为(28．19±3．03)kPa。手术应用个体充气压力,止血效果优147例,良3例,术后均无止血带副损伤。结论以上肢缚扎止血带处肢体周径(cm)作为充气压力的参考值(kPa),是上肢手术适宜的个体充气压力。     

选择性上肢神经阻滞和静脉局部麻醉的进展

临床实践中，尽管臂丛神经阻滞可采用多种人路以满足上肢区域麻醉的需要，但有时仍需应用一些不常见的技术，如选择性上肢神经阻滞和静脉局部麻醉（IVRA），来阻滞非源自臂丛的神经或弥补臂丛神经阻滞不全。     

New regimen for interpleural block in children

A new regimen for postoperative analgesia after thoracic surgery is proposed. Eight children received an interpleural infusion using bupivacaine 0.1% in a regimen from 0.5 ml·kg^?1·h^?1 up to 1 ml·kg^?1·h^?1, for 48 h according to the pain scores. The plasma levels after 24 h and 48 h were measured as well as the pleural level and in two patients the free fraction of plasma bupivacaine and the plasma PPX (a metabolite of bupivacaine) and one patient the orosomucoid (main plasma protein involved in bupivacaine protein binding) were also measured pre and postoperatively. The results shows the safety of such a regimen, for two days of postoperative analgesia.     

A Ro/SS-A auto-antibody positive mother's infant revealed congenital complete atrioventricular block,followed by insulin dependent diabetes mellitus and multiple organ failure

We experienced a congenital complete atrioventricular block infant who was born from a Ro/SS-A antibody positive mother. Ro/SS-A antibody was also found in this baby which was presumed to be mediated by the maternal placenta. Temporary cardiac pacing was required at birth and pacemaker implantation was performed at 9 months. At 11 months of age, the baby fell into shock and experienced multiple organ failure because of diabetes mellitus-induced coma. The association between congenital complete heart block and the Ro/SS-A antibody is well known. However, the accompaniment of insulin-dependent diabetes mellitus has not been reported previously. As the Ro/SS-A antigen appears in the cytoplasm of many tissues, the possibility of an association between Ro/SS-A antibody and diabetes mellitus is difficult to deny. We report this rare case to draw attention to the possibility that babies who are born from an Ro/SS-A antibody positive mother may develop diabetes mellitus as well as congenital complete heart block.