Usefulness of muscle denervation as an MRI sign of peripheral nerve pathology

Peripheral nerve disorders may be classified into compressive or entrapment neuropathies and non‐compressive neuropathies. Muscle denervation recognized on MRI may be a useful sign in the diagnosis of peripheral nerve disorders. Acute or subacute denervation results in prolonged T2 relaxation time, producing increased signal in skeletal muscle on short tau inversion‐recovery and fat‐suppressed T2‐weighted images. Chronic denervation produces fatty atrophy of skeletal muscles, resulting in increased muscle signal on T1‐weighted images. This review will outline and illustrate the various ways that muscle denervation as seen on MRI may assist in the diagnosis and localization of peripheral nerve disorders.     

RP—HPLC法测定醋柳黄酮固体脂质纳米粒的含量及包封率

目的:建立 HPLC 法测定醋柳黄酮固体脂质纳米粒(TFH-SLN)含量及包封率的方法。方法:采用 Diamonsil~(TM)(钻石)ODS 柱(4.6 mm×250 mm,5 μm);流动相为甲醇-0.02 mol·L~(-1)磷酸溶液(52∶48);柱温35℃;流速为0.8 mL·min~(-1);紫外检测波长为370 nm;采用超速离心法分离测定 TFH-SLN 中的游离药物。结果:在本色谱条件下醋柳黄酮中异鼠李素和槲皮素与辅料及溶剂峰能够达到有效分离,异鼠李素及槲皮素均在16～56μg·mL~(-1)范围内线性关系良好,相关系数分别为0.9992及0.9994(n=5),回收率在98.0%～102.0%之间。结论:测定方法简便、准确、可靠,灵敏度高,可作为质量控制方法。     

吲达帕胺前体药物脂质体的制备

目的：对吲达帕胺进行前体修饰，并对该前体进行脂质体包封。方法：通过吲达帕胺末端游离氨基与月桂酰氯进行酰化反应，在其上修饰一条长的碳链制成月桂酰吲达帕胺，通过^1H—NMR对其进行了化合物结构的确证，分散介质中加入适量的二价阳离子Ca^2＋，用乙醇注入法制备月桂酰吲达帕胺脂质体。结果：脂质体对吲达帕胺包封率从10％以下提高到对月桂酰吲达帕胺的90％以上。结论：吲达帕胺末端游离氨基的长碳链修饰，能极大地提高脂质体对该药物的包封率。     

高效液相色谱法测定槲皮素纳米脂质体药物含量及包封率

目的:建立测定槲皮素脂质体药物含量及包封率的 RP—HPLC 法。方法:采用 Diamonsil~(TM)C_(18)柱(4.6 mm×250 mm,5μm);流动相:甲醇-0.4%磷酸(55:45);柱温:30℃;流速:1.0 mL·min~(-1);紫外检测波长:360 nm。采用透析法分离槲皮素脂质体中的游离药物。结果:在本色谱条件下槲皮素与辅料及溶剂峰分离良好,槲皮素在1.2～50μg·mL~(-1)范围内线性关系良好(r=0.9998,n=5),回收率在99.7%～101.2%之间,日内 RSD 及日间 RSD 均小于2%(n=5)。结论:该方法准确可靠、简单快速,可用于槲皮素纳米脂质体含量及包封率的测定。     

HPLC法测定苦参碱白蛋白纳米粒的包封率

建立苦参碱白蛋白纳米粒药物包封率测定的 HPLC 法。方法:采用离心超滤法分离苦参碱白蛋白纳米粒中的游离苦参碱,以 HPLC 为分析手段对纳米粒包封率进行测定评价。色谱条件:采用 Kromasil C_(18)柱(4.6 mm×150 mm,5μm);流动相:乙腈-0.02mol·L~(-1)磷酸二氢钾溶液(6:94);流速:1.0 mL·min~(-1);检测波长:210 nm;温度:25℃。结果:采用离心超滤法分离,HPLC 法测定,可达到游离苦参碱与纳米粒的有效分离,苦参碱峰与溶剂峰分离良好,苦参碱浓度在6～100μg·mL~(-1)范围内线性关系良好(r=0.9999),平均回收率在95.06%～100.9%之间,日内 RSD 和日间 RSD 均小于2%(n=5)。结论:本方法准确可靠,简单快速,可用于苦参碱白蛋白纳米粒药物包封率的测定。     

环孢素长循环脂质体的制备、特征和药动学研究

 目的制备环孢素的长循环脂质体,改善环孢素的溶解度,替代临床现用制剂中所用的有毒致敏辅料,延长药物在体循环中的停留时间。方法采用改良的乙醇注入结合超声分散的方法制备环孢素长循环脂质体,蔗糖作为冻干保护剂冻干。同时采用葡聚糖凝胶柱、透析和超滤的方法分离游离药物和脂质体,以HPLC计算环孢素的包封率(EE)。以载药量、粒径等为指标,采用中心复合设计对处方进行优化,最优处方配比为卵磷脂、胆固醇、环孢素和单甲氧基聚乙二醇磷脂酰乙醇胺摩尔比为(95/40/4.5/5)。研究了大鼠体内的药动学,并与市售山地明注射剂作比较。结果优化条件下制备的长循环脂质体的体积平均粒径是(50.3±5.1)nm(n=6),采用超滤法测得的包封率为97%。体内药动学研究表明,与山地明相比,环孢素长循环脂质体的Vc减小30%(P<0.01),AUC增加30%(P<0.05),MRT延长8%(P<0.01),CLt减少59%(P<0.05)。结论本法制备的聚乙二醇修饰环孢素脂质体,粒径满意,包封率高,初步的体内外研究数据表明,具有一定的长循环作用,制备方法简单,重现性好。     

Preserved cutaneous silent periods in severe entrapment neuropathies

Noxious digital nerve stimulation during isometric contraction of hand muscles leads to transient suppression of the electromyographic activity, the so-called cutaneous silent period (CSP), which is mostly due to a spinal reflex mediated by A-delta fibers. We investigated two patients with carpal tunnel syndrome (CTS) and two patients with ulnar entrapment at the elbow (UNE), in whom routine sensory conduction studies failed to document afferent fiber continuity across the lesion site. In three patients, motor nerve conduction studies and electromyography failed to demonstrate intact efferent fibers. Noxious stimulation of digit II elicited distinct CSPs in ulnar-innervated hand muscles in both patients with CTS, and stimulation of digit V evoked CSPs in median-innervated hand muscles in both UNE patients. The presence of a CSP can only be explained by preserved A-delta fibers crossing the respective lesion site. Thus, preserved CSPs may serve to document residual nerve continuity in severe entrapment neuropathies when fast-conducting fibers are so compromised that their continuity cannot be detected by standard electrodiagnostic techniques.     

Retained intra‐aortic balloon pump catheter causing acute ischaemic limb: Report of two cases

Intra‐aortic balloon pump (IABP) catheter is used widely in the management of left heart failure. Its complications are well described; however, retained IABP catheter is an extremely rare but serious complication, which is seldom described. Fewer than 20 cases have been reported. Two cases of entrapment of IABP catheter which resulted in acute limb ischaemia requiring surgical intervention for its removal are reported. Its prevention and management are also discussed.      

超滤法-HPLC法测定灯盏花素脂质体包封率

目的对灯盏花素脂质体进行质量评价,测定灯盏花素脂质体包封率。方法采用超滤法分离脂质体与游离药物;采用Kromasil ODS柱(200 mm×4.6 mm,5μm),流动相为甲醇乙腈20 mmol.L-1磷酸盐缓冲液(pH值为2.5)(体积比为17∶17∶66),流速为0.8 mL.min-1,检测波长为334 nm,测定药物含量,计算包封率。结果超滤法能很好的将脂质体与游离药物分离,游离药物的平均回收率在95.9%~97.6%,加样回收率在96.4%~97.1%,脂质体不能透过超滤膜;该色谱条件下,灯盏乙素得到良好分离,辅料不干扰测定,灯盏乙素在1.0~40.0 mg.L-1内线性关系良好(r=0.999 9),日内和日间RSD均小于2.0%(n=5),加样回收率在99.7%~100.1%之间,RSD小于1.23%。结论该方法可用于灯盏花素脂质体的质量控制。     

氟比洛芬脂质体的制备和体外透皮实验

目的研究氟比洛芬脂质体的制备和体外透皮扩散。方法乙醇注入法制备不同粒径的氟比洛芬脂质体,微型柱离心法分离脂质体和游离药物,采用Franz扩散池,考察氟比洛芬脂质体透过单位面积鼠皮的累积量、渗透系数和皮内滞留量。结果相对于大粒径脂质体,小粒径脂质体显著提高氟比洛芬的透皮速率;开放式给药组的累积透过量、渗透系数和皮内滞留量高于封闭组。结论脂质体给药方式和脂质体的粒径是影响氟比洛芬体外透皮的主要因素。