Computerized axial tomo-epidurographic and radiographic documentation of unilateral epidural analgesia

A 23-year-old primigravid patient who received epidural analgesia for pain of labour presented with persistent, apparently irremediable, unilateral analgesia. Computerized axial tomo-epidurography demonstrated absence of circumferential spread due to lateral placement of the catheter. Transforaminal escape of contrast medium into the paravertebral area had occurred and anterior and posterior midline partitioning of the epidural space was obvious. All the usual measures to promote contralateral analgesia, except re-insertion of the catheter, had been tried without success.     

星状神经节阻滞对急性心肌梗死患者应激激素水平的影响

目的 观察星状神经节阻滞对急性心肌梗死患者体内去甲肾上腺素（NE）、肾上腺素（adrenalin，ADR）、促肾上腺皮质激素（ACTH）、皮质醇（cortisol，ODR）等应激激素水平的影响。方法 选择已被确诊为急性心肌梗死患者68例，随机分为治疗组（34例）和对照组（34例）．治疗组患者采用星状神经节阻滞治疗，两周为一疗程；对照组常规内科治疗。于阻滞前及阻滞后24、48、72、144h抽取静脉血标本。测定各时段的NE、肾上腺素、ACTH、皮质醇应激激素的含量。结果 阻滞后治疗组患者的NE、ADR、ACTH、ODR应激激素的含量与阻滞前及同时段的对照组比较有明显的降低，P〈0．05。结论 星状神经节阻滞可快速有效地缓解由于冠状动脉供血不足引起的缺血性疼痛，抑制应激反应，降低患者体内NE、ADR、ACTH、00R应激激素的水平。     

Decrease of potassium permeability by intracellular application of sodium ions in snail neurons

In the identified neurons B1, B2 and B3 of Helix pomatia an intracellular injection of Na+ induced an outward current in 10% and an inward current in 90% of the experiments. The outward current was associated with an increase and the inward current with a decrease of the membrane conductance. Both currents reversed at membrane potentials of between -60 and -70 mV. Inward currents were also elicited by intracellular Li+ or tris-[hydroxymethyl]-aminomethane (Tris+) injection. All inward currents were reduced by extracellular administration of tetraethylammonium or quinine. It is suggested that the outward current represents a calcium-activated potassium current and that the inward current is due to a blockade of potassium channels from the intracellular side.     

Effects of local nerve cooling on conduction in vagal fibres shed light upon respiratory reflexes in the rabbit

In ten vagus nerves the effect of local cooling on the compound action potential was studied in the temperature range of 34 to 0 °C in spontaneously breathing, anaesthetized rabbits. The mean temperature at which the myelinated (A) fibres were completely blocked, was 10.2±2.4 °C (mean ± S.D.). In nine nerves, local vagus cooling to 0 °C failed to block all non-myelinated (C) fibres. In one nerve, total blocking occurred at 2.0 °C. We conclude that in the rabbit, the earlier found increase in tonic activity of the diaphragm following lung inflation or deflation during bilateral local vagus cooling to a temperature between 8 and 0 °C is due to afferent impulses in vagal C fibres.     

腰方肌阻滞对腹腔镜肝切除术后急性疼痛影响的回顾性研究

目的　回顾性分析腰方肌阻滞对腹腔镜肝切除术后急性疼痛的影响。 方法　选取2018年1~8月于我院行择期腹腔镜肝切除术患者24例，平均分为2组，对照组仅采用全凭静脉麻醉，腰方肌组采用腰方肌阻滞（quadratus lumborum block，QLB）联合全凭静脉麻醉，两组术后镇痛方案均为自控静脉镇痛（patient controlled intravenous analgesia，PCIA）。麻醉期间常规监测患者心率、血压、脉搏氧饱和度，采用腰方肌阻滞的患者在阻滞完成后15 min记录阻滞平面。分别于术前、术后2 h、术后8 h、术后12 h、术后24 h和术后48 h对患者进行VAS评分。记录患者术中和术后PCIA阿片类药物消耗情况及术后48 h内恶心呕吐、尿潴留、瘙痒和呼吸抑制等并发症发生情况。 结果　腰方肌组患者在术后2、8、12 h 3个时间点VAS评分显著低于对照组，差异具有统计学意义（P<0.05）。腰方肌组12名患者最高阻滞平面为T6（T6~10），最低阻滞平面为L1（T12~L1）。与对照组相比，腰方肌组术中和术后PCIA阿片类药物消耗均显著减少，差异具有统计学意义（P<0.05）。 结论　腰方肌阻滞能够有效缓解腹腔镜肝切除术患者术后急性期疼痛，减少围术期阿片类药物用量。     

Changes of energy metabolism,myosin light chain composition,lactate dehydrogenase isozyme pattern and fibre type distribution of denervated fast-twitch muscle from rabbit after low frequency stimulation

The influence of low frequency (8–10 Hz) electrical stimulation on denervated fast-twitch muscle from rabbit was investigated. Prolonged direct stimulation of denervated muscle resulted in higher oxidative enzyme activities. Furthermore, single fibre analyses for succinate dehydrogenase showed a more uniform distribution of activity in stimulated-denervated muscle when compared to normal muscle. As was also the case following stimulation of innervated muscle, glycolytic enzymes were decreased in activity and the LDH-isozyme pattern also shifted towards heart type. No change of the myosin light chain pattern could be observed after 56 days of stimulation.This study was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 138, and by grant NI 204-2-2. H. R. is grateful to Dr. Dirk Pette for his guidance and encouragement during this work, which was done in Dr. Pette's laboratory at the University of Konstanz     

Autoantibody response to the Ro/La particle may predict outcome in neonatal lupus erythematosus.

This study was undertaken to determine the role of antibodies against both recombinant Ro (r-Ro) and La (r-La) proteins and polypeptides derived from the recombinant La protein in predicting fetal and neonatal outcome in children at risk to develop neonatal lupus erythematosus (NLE). All sera were obtained in the perinatal period and quantitative ELISA assays were used. We collected 41 maternal sera within 2 months of delivery of a child with NLE (21 with congenital heart disease block (CHB) and 20 with dermatologic NLE) and 19 sera from anti-Ro and/or anti-La antibody-positive mothers with systemic lupus erythematosus (SLE) who delivered a child without NLE. All sera were tested for anti-r-La and anti-r-Ro antibodies by ELISA, and most sera were tested for antibodies directed against La polypeptides by immunoblot. We found significantly higher anti-r-La antibody levels in the sera from mothers of children with NLE compared with sera from mothers of unaffected children (0.67 +/- 0.43 versus 0.14 +/- 0.30; P < 0.0001). There was a statistically significant difference in the mean anti-r-La levels between the sera of mothers of children with CHB compared with dermatologic NLE (0.51 +/- 0.45 versus 0.83 +/- 0.37 respectively; P = 0.0091). When we examined antibodies directed against the recombinant 52-kD Ro protein, there was a statistically significant elevation of titres in the sera of mothers of NLE children (0.77 +/- 0.35) compared with non-NLE mothers (0.29 +/- 0.39; P < 0.0001). There was no difference in the r-Ro levels between mothers of children with dermatologic NLE compared with CHB (0.82 +/- 0.37 versus 0.71 +/- 0.74; P = 0.32). When we examined polypeptides derived from the recombinant La protein, the mean number of polypeptides recognized by sera from mothers of children with NLE was significantly higher than the mean number of polypeptides recognized by sera from mothers of unaffected children (5.1 +/- 0.54 versus 2.3 +/- 0.54 respectively; P < 0.001). More importantly, when we examined the individual polypeptides, we found that only sera from mothers of children with NLE and not from mothers of unaffected children recognized a polypeptide designated DD (30% versus 0%, respectively). These studies indicate that the autoantibody response to the Ro/La particle can differentiate sera from mothers of children with NLE and sera from mothers of unaffected children. Furthermore, there was a difference in the anti-La autoantibody response between mothers of children with CHB and dermatologic NLE.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fast and slow blockades of the inward-rectifier K+ channel by external divalent cations in guinea-pig cardiac myocytes

The present patch-clamp study shows that external Mg²⁺, Ca²⁺ and Sr²⁺ decrease the unit amplitude of inward current through the inward-rectifier K⁺ channel in a concentration-dependent manner. Sr²⁺ produces a voltage-dependent flickering block as well, and the fractional electrical distance between the external orifice and the Sr²⁺ binding site () is 0.73. The decrease of unit amplitude is reversible and voltage independent while it does not increase the noise level on the open-channel current. Unit current decreased by Mg²⁺ or Ca²⁺ has a longer mean open time, which is inversely proportional to the unit amplitude. External Mg²⁺ does not decrease the amplitude of unit outward current. A surface potential shift, measured using voltage-dependent Cs⁺ block (=1.60), failed to explain the current decrease. Therefore, we conclude that (1) the external divalent cations cause an extremely fast channel block, which appears as a decreased amplitude of the unit current on the recording system; (2) the blocking site (fast site) is present near the external orifice of the channel, and it is separate from the blocking site (slow site) to which Cs⁺ and Sr²⁺ bind.     

Mechanisms of the inhibition of Shaker potassium channels by protons

Potassium channels are regulated by protons in various ways and, in most cases, acidification results in potassium current reduction. To elucidate the mechanisms of proton-channel interactions we investigated N-terminally truncated Shaker potassium channels (K_v1 channels) expressed in Xenopus oocytes, varying pH at the intracellular and the extracellular face of the membrane. Intracellular acidification resulted in rapid and reversible channel block. The block was half-maximal at pH 6.48, thus even physiological excursions of intracellular pH will have an impact on K⁺ current. The block displayed only very weak voltage dependence and C-type inactivation and activation were not affected. Extracellular acidification (up to pH 4) did not block the channel, indicating that protons are effectively excluded from the selectivity filter. Channel current, however, was reduced greatly due to marked acceleration of C-type inactivation at low pH. In contrast, inactivation was not affected in the T449V mutant channel, in which C-type inactivation is impaired. The pH effect on inactivation of the wild-type channel had an apparent pK of 4.7, suggesting that protonation of extracellular acidic residues in Kv channels makes them subject to pH regulation.