氨基糖苷类抗生素的发展历程

抗生素的定义，首先来自于20世纪40年代链霉素的发现。在随后的几十年中，其他氨基糖苷类抗生素家族被大量发现并广泛应用，一度成为抗革兰阴性菌感染的首选抗生素。但由于其毒副作用较大，并且细菌对其不断产生耐药性，加上其他结构类别的新型抗生素的不断发现，使其一度几乎退出历史舞台。然而随着多重耐药细菌引起的感染率急剧上升，人们开始关注氨基糖苷类抗生素作为几种重要的治疗革兰阴性病原体的方案之一，并且发掘了其在治疗感染性疾病、艾滋病和遗传性疾病的潜力，使这个“老牌”抗生素重焕生机。     

Poly-l-aspartic acid protects cultured human proximal tubule cells against aminoglycoside-induced electrophysiological alterations

Cultured human proximal tubule cell monolayers maintained on permeable supports were treated simultaneously with the aminoglycoside antibiotic, gentamicin, and poly- -aspartic acid (PAA), an inhibitor of aminoglycoside nephrotoxicity. Following 4 days of exposure, cell monolayers were placed into Ussing chambers to allow monitoring of transepithelial electrical properties. For each of the three cell isolatation examined, aminoglycoside-induced alterations in electrogenic transport, reflected by changes in short-circuit current (Isc), as well as alterations in paracellular properties, indicated by changes in transepithelial electrical resistance (R_T), were diminished in the presence of PAA. Alterations resulting from selective basolateral exposure to gentamicin were unchanged in the case of apically applied PAA and attenuated only when PAA acid was added basolaterally. This is the first demonstration of PAA inhibition of aminoglycoside-induced cellular alterations involving human cells.     

鄂西苗族氨基糖甙类抗生素致聋患者的mtDNA1555位点突变研究

目的为探讨遗传因素在鄂西苗族氨基糖甙类抗生素致聋(AAID)发生中的作用,从分子水平研究该病的发病机制.方法对鄂西苗族部分家系及医学散发病例通过问卷调查和进行听力测试,确诊为AAID的82名患者,采外周血作PCR-RFLP分析,对照组为正常苗族50名.结果82名患者中27例具有mtDNA1555A→G异质性突变,10例为均质性突变,该位点突变率为45.1%,其中异质性突变占72,9%,而对照组均无此突变.结论mtDNA1555A→G突变是鄂西苗族个体对氨基糖甙类抗生素易感致聋的分子基础,异质性突变在苗族AAID中发生率较高.     

Kanamycin ototoxicity in glutamate transporter knockout mice

Glutamate-aspartate transporter (GLAST), a powerful glutamate uptake system, removes released glutamate from the synaptic cleft and facilitates the re-use of glutamate as a neurotransmitter recycling system. Aminoglycoside-induced hearing loss is mediated via a glutamate excitotoxic process. We investigated the effect of aminoglycoside ototoxicity in GLAST knockout mice using the recorded auditory brainstem response (ABR) and number of hair cells in the cochlea. Kanamycin (100 mg/mL) was injected directly into the posterior semicircular canal of mice. Before the kanamycin treatment, there was no difference in the ABR threshold average between the wild-type and knockout mice. Kanamycin injection aggravated the ABR threshold in the GLAST knockout mice compared with the wild-type mice, and the IHC degeneration was more severe in the GLAST knockout mice. These findings suggest that GLAST plays an important role in preventing the degeneration of inner hair cells in aminoglycoside ototoxicity.     

20株阴沟肠杆菌耐药性及氨基糖苷类修饰酶基因分析

目的明确临床分离的20株阴沟肠杆菌耐药性及氨基糖苷类修饰酶基因存在状况。方法采用ATB药敏试验板微量肉汤法测定临床分离的20株阴沟肠杆菌对20种抗菌药物的敏感性，采用聚合酶链反应及序列分析的方法分析氨基糖苷类修饰酶基因型。结果该20株菌呈现多重耐药，对亚胺培南和美罗培南均敏感，对阿莫西林、阿莫西林／克拉维酸、头孢噻吩和头孢西丁完全耐药，对头孢吡肟及4种氨基糖苷类抗生素阿米卡星、庆大霉素、妥布霉素和奈替米星的耐药率分别为25．0％、60．0％、85．0％、90．0％和90．0％，其余9种的耐药率在80．0％～95．0％之间。19株(95．0％)检出氨基糖苷类修饰酶基因；aac(6′)-Ⅰ、aac(3)-Ⅱ、ant(3″)-Ⅰ、ant(2″)-Ⅰ和aph(3′)-Ⅵ基因的阳性率分别为80．0％、50．0％、40．0％、5．0％和5．0％；而aog2(3)-Ⅰ、aac(3)-Ⅲ、aac(3)-Ⅳ和aac(6′)-Ⅱ基因均阴性。结论临床分离的阴沟肠杆菌多重耐药严重，氨基糖苷类修饰酶基因携带率很高。     

电喷雾离子化多级质谱对几种氨基糖苷类抗生素特征碎片的分析

应用电喷雾离子化多级质谱法分析几种含2-脱氧链霉胺的氨基糖苷类抗生索的碎片离子，并对它们的裂解规律进行分析归纳。除其它特征碎片离子峰外，所有测试样品的质谱图中都存在质荷比为163．1的归属于2-脱氧链霉胺的碎片离子峰。这些裂解规律可应用于微生物新药筛选中早期快速鉴别含2-脱氧链霉胺的氩基糖苷类抗生索，对氨基糖苷类抗生索的生产、质量监控以及在环境和食品中的微量检测也有指导意义。     

Lysosomal augmentation during aminoglycoside uptake in cochlear hair cells

Aminoglycoside antibiotics, such as kanamycin, have ototoxic side effects, which often result in degeneration of cochlear and vestibular hair cells in the inner ear. Cytotoxic effects of aminoglycosides, however, do not appear immediately after cellular uptake of aminoglycosides. In order to understand the mechanisms responsible for the delayed emergence of aminoglycoside ototoxicity, changes in lysosomal activities in cochlear hair cells were evaluated during a repeated administration of kanamycin by two methods. Electron microscopic localization of acid phosphatase (AcPase) revealed that AcPase started to accumulate in vesicles 27 h after the start of kanamycin administration. In addition, the number and size of AcPase-filled vesicles increased with repeated kanamycin doses. Confocal microscopic localization of the LysoTracker probe, a vital lysosomal marker, showed an increase in the size of lysosomes in hair cells that were treated with kanamycin. The temporal changes in the augmentation of lysosomes paralleled those in intracellular kanamycin levels. These results suggest that the intralysosomal compartments can accumulate extensive amounts of aminoglycosides, which might lead to lysosomal swelling and subsequent rupture.     

4种氨基甙类抗生素对膈肌和四肢肌肉的松弛作用

目的　探讨氨基甙类抗生素—阿贝卡星 (arbekacin ,ABK) ,阿司霉素 (astromicin ,ASTM) ,异帕咪星 (isepamicin ,ISP)和奈替咪星 (netilmicin ,NTL)在家兔的膈肌 ,前胫骨肌和比目鱼肌的神经肌肉抑制作用。方法　将 2 4只家兔平均分成 4组 ,戊巴比妥静脉麻醉下分别游离膈神经 -膈肌 ,胫神经 -前胫骨肌和腓总神经 -比目鱼肌 ,然后在膈肌表面和肢体肌远端肌腱固定连接肌张力换能测定装置以及在上述神经固定神经刺激电极 ,给予频率为 0 1Hz ,持续 0 1ms ,间隔 10s的超强电刺激。采用累积剂量给药法分别静脉注射以上被验 4种抗生素 ,记录刺激神经所诱发的肌肉等张颤搐强度 ,评价抗生素在 3种肌群不同神经肌肉抑制作用。结果　 4种抗生素在以上 3种骨骼肌肌群均表现不同程度的抑制作用 ,在初期剂量给药时 ,膈肌对药物的敏感性较明显 ,比目鱼肌表现相对最弱。抗生素作用于这 3种肌群的ED50 值大小顺序为比目鱼肌 >前胫骨肌 >膈肌和ED95值大小顺序为比目鱼肌 >膈肌 >前胫骨肌。抗生素在前胫骨肌和比目鱼肌的ED50 值约分别为膈肌的 1 5和 2 7倍。 4种抗生素间神经肌肉抑制作用强度顺序为NTL >ABK >ASTM >ISP。这些抗生素引起的神经肌肉抑制作用可以被新斯的明和钙剂所拮抗。结论　 4种氨基甙类抗生素在膈肌相     

Prev-DAF试剂盒分析线粒体基因1555A-G突变

目的建立应用标准试剂盒方法检测线粒体基因1555A-G(mtDNA1555A-G)突变的程序,进行母系遗传耳聋家系的基因型分析.方法采用Prev-DAF试剂盒分析14个母系遗传耳聋家系,共检测耳聋患者34个,正常个体11个,并以Alw26酶切和测序方法验证试剂盒检测的准确性.结果Prey-DAF试剂盒检测结果证实13个家系中33个耳聋患者携带有mtDNA1555A-G突变,另1个耳聋家系中的一名耳聋患者不携带此突变,11个正常个体中无此突变,试剂盒检测方法与Alw26I酶切法和测序结果完全吻合.结论在中国,mtDNA1555A-G氨基糖甙类抗生素致聋的家系多,分布广,Prev-DAF试剂盒在分析线粒体基因1555A-G突变方面具有简单、低耗、结果直观的特点,适合在中国用于进行此突变的大规模筛查或预防性检查.     

Gentamicin ototoxicity: clinical features and the effect on the human vestibulo-ocular reflex

Conclusions. Gentamicin ototoxicity presents with gait imbalance and oscillopsia, but only rarely with hearing loss and vertigo. Sinusoidal rotational stimuli with high accelerations such as the bedside head-thrust test or rotational step changes in velocity are useful to diagnose bilateral vestibulopathy. Objective. To describe the salient clinical features and vestibular testing results in gentamicin ototoxicity. Patients and methods. A retrospective review of the quantitative vestibular function testing results for patients presenting to the UCLA Neurotology Clinic with gentamicin ototoxicity over the past 10 years (n=35). Results. All patients presented with imbalance and 33 out of 35 had oscillopsia. Three patients reported a noticeable change in hearing and five reported vertigo. Of the 35 patients, 15 were in renal failure at the time of gentamicin administration. Patients with pre-existing peripheral neuropathy compensated poorly. Sinusoidal rotational testing demonstrated profoundly decreased gain and increased phase lead over the entire frequency range, with a subset of patients having relatively preserved gain at the intermediate frequencies (0.8–1.6 Hz) and low acceleration (<30°/s). There was little or no response to high acceleration step changes in velocity. The time constant measured both by sinusoidal and step responses was ultra-low. All patients tested had a positive head-thrust test bilaterally.