氯喹对三阴乳腺癌MDA-MB-231细胞增殖的影响及其机制

目的观察氯喹对三阴乳腺癌MDA-MB-231细胞增殖的影响,并探讨其机制。方法用氯喹20,40和80μmol·L~(-1)分别处理MDA-MB-231细胞24和48 h,采用CCK-8法和细胞克隆形成实验检测细胞增殖,流式细胞术检测细胞周期和凋亡,Western印迹法检测细胞周期相关蛋白即细胞周期蛋白D3、细胞周期蛋白依赖性激酶2(CDK2)和CDK4,细胞凋亡相关蛋白即活化胱天蛋白酶3和活化聚腺苷二磷酸-核糖聚合酶(PARP)及自噬标志蛋白即自噬微管相关蛋白轻链3B(LC3B)和自噬底物SQSTM1表达水平。结果氯喹20,40和80μmol·L~(-1)与MDA-MB-231细胞作用24和48 h后,均能有效抑制细胞增殖(P<0.01)。与细胞对照组相比,氯喹20和40μmol·L~(-1)处理24 h,G_0/G_1期细胞百分比显著增高(P<0.01);80μmol·L~(-1)组G_2/M期细胞百分比升高(P<0.01),且细胞凋亡率增加(P<0.01)。处理48 h,与细胞对照组相比,氯喹用药3组细胞凋亡率均显著升高(P<0.05)。氯喹3组处理24 h,与细胞对照组相比,细胞周期蛋白D3、CDK2和CDK4表达水平降低(P<0.01),活化胱天蛋白酶3和活化PARP表达增强(P<0.01),LC3B和SQSTM1表达水平显著升高(P<0.01)。结论氯喹可通过抑制MDA-MB-231细胞自噬、阻滞细胞周期进程并促进细胞凋亡而抑制其增殖。     

中介素对缺氧/复氧大鼠肾小管上皮细胞增殖作用及细胞周期的影响及其机制

目的探讨中介素(intermedin,IMD)对大鼠近端肾小管上皮细胞NRK-52E缺氧/复氧(H/R)后细胞增殖、细胞周期的影响。方法 NRK-52E细胞随机分为对照组,模型组:缺氧/复氧组(H/R)、H/R+空质粒组、H/R+IMD质粒组。MTT法检测细胞增殖,比色法检测培养基上清LDH含量,流式细胞术检测细胞周期,Real time-PCR法和Western blot法检测cyclin D1、CDK、p57 mRNA及蛋白表达,间接免疫荧光染色检测cyclin D1亚细胞定位。结果 1与对照组相比,H/R组培养基中LDH含量升高了106%,同时细胞存活率明显下降,与H/R组比较,H/R+IMD组培养基中LDH含量下降了33.85%(P<0.01),而细胞存活率增高(79.15%±1.42%vs 61.22%±1.63%,P<0.05),2细胞周期结果显示,与对照组相比,H/R组细胞G0/G1期比例增加,S期细胞比例降低(P<0.05);与H/R组比较,H/R+IMD组G0/G1期细胞比例明显降低,而S及G2期细胞比例增加(P<0.05)。3H/R可增加cyclin D1、CDK4及p57的表达也增加(与对照组比较,P<0.05);而IMD可进一步上调cyclin D1、CDK4的表达,同时下调p57的表达,与对照组及H/R组相比差异具有显著性(P<0.05)。4免疫荧光检测结果可见,cyclin D1呈红色荧光,在NRK-52E细胞内主要表达在细胞核中。结论 IMD可以上调cyclin D1、CDK4蛋白表达,下调p57的表达,促进细胞周期进展,从而加速肾组织IRI后细胞增殖和修复。     

白藜芦醇对人胚肺成纤维细胞株MRC-5生长的抑制作用

目的探讨白藜芦醇(Res)对人胚肺成纤维细胞生长的抑制作用及相关机制。方法以人胚肺成纤维细胞MRC-5为研究对象,分别予20μL二甲基亚砜(DMSO)及0、12.5、25、50、100、200μmol·L-1Res处理细胞24、48、72 h,通过MTT法分析细胞增殖抑制率。另外,以20μL DMSO(溶媒组)及50、100μmol·L-1Res孵育细胞48 h,采用流式细胞术检测细胞周期和凋亡率,行原位缺口末端标记法(TUNEL)测定细胞凋亡指数(AI),应用荧光实时定量PCR和Western blot分别检测细胞周期蛋白D1(cell cycle protein D1,Cyclin D1)、细胞周期蛋白依赖激酶4(cyclin-dependent kinase 4,CDK4)mRNA与蛋白表达,Western blot检测Bcl-2、Bax蛋白表达。结果随着Res浓度的升高和处理时间的延长,细胞增殖抑制率逐渐增加(P<0.01)。在共同培养48h后,50、100μmol·L-1Res处理组S、G2/M期DNA比例及Cyclin D1、CDK4 mRNA与蛋白表达水平、Bcl-2蛋白表达水平降低,而G0/G1期DNA比例、AI、凋亡率及Bax蛋白表达水平增加,与溶媒组比较,差异均有显著性(P<0.01),并且100μmol·L-1Res效果强于50μmol·L-1(P<0.01)。结论Res能抑制MRC-5细胞增殖,其机制可能与阻碍细胞周期进展及促进细胞凋亡有关。     

苦参素对实验性肝癌PCNA、cyclinD1、CDK4表达的影响

目的 :研究苦参素对 2 乙酰氨基芴 (2 AAF)诱发大鼠实验性肝癌的防治作用 ,并探讨其抑制肝癌细胞增殖的机制。方法 :以 2 AAF喂饲SD大鼠制备肝癌模型。给予不同剂量的苦参素腹腔注射 ,观察肿瘤生成状况 ;免疫组化方法检测增殖细胞核抗原 (PCNA)蛋白的表达 ;RT PCR检测细胞周期素D1(cyclinD1)、细胞周期蛋白依赖激酶 4 (CDK4 )mR NA的表达。结果 :苦参素各防治组大鼠肝表面癌结节数明显低于模型组 ,预防组肝表面结节数最少。苦参素各预防治疗组PCNA和cyclinD1、CDK4的表达显著低于模型组 (P <0 .0 1)。结论 :苦参素有预防或延缓 2 AAF诱发大鼠肝癌发生的作用 ,其机制可能通过抑制cyclinD1、CDK4mRNA和PCNA蛋白的表达 ,从而诱导细胞周期阻滞 ,抑制肝癌细胞过度增殖。     

缺氧复氧诱导的心肌细胞凋亡及一氧化氮对此过程的作用

目的　研究缺氧复氧损伤诱导体外培养的新生大鼠心肌细胞凋亡及一氧化氮 (NO)对此过程的作用。方法　取体外培养的新生大鼠心肌细胞 ,分两组 ,一组于 0 95N2 、0 0 5CO2 孵箱中培养 16h、32h、4 8h ,再恢复正常条件培养6h ,造成缺氧复氧损伤的细胞模型 ,TUNEL法观察心肌细胞凋亡形态学特征 ,流式细胞仪检测心肌细胞凋亡率 ;另一组缺氧培养 16h、32h、4 8h后 ,将NO供体亚硝基青霉胺(SNAP)加入培养基中 ,使其终浓度为 10 0 μmol·L-1,再于正常条件培养 6h ,检测心肌细胞凋亡率。结果　心肌细胞在缺氧 16h、32h和 4 8h后复氧 6h ,TUNEL法可检测到阳性的凋亡细胞 ,流式细胞仪检测其凋亡率分别为 :5 5 %±0 7% ,11 0± 1 1%和 14 2 %± 1 6 % ;心肌细胞缺氧培养16h、32h、4 8h后加入SNAP ,再复氧 6h ,流式细胞仪检测其凋亡率分别为 :3 2 %± 0 7% ,7 8%± 0 7%和 10 9%±1 0 %。结论　缺氧复氧损伤引起的心肌细胞凋亡率随着缺氧时间的延长而增高 ;NO对缺氧复氧损伤引起的心肌细胞凋亡有抑制作用     

黄连碱对人乳腺癌MDA-MB-231细胞周期和增殖的作用及其机制

目的 探讨黄连碱对人乳腺癌细胞株MDA-MB231细胞周期和增殖的作用及相关机制.方法 MTT法和瑞-姬氏染色法分别检测黄连碱对MDA-MB-231细胞增殖的影响,流式细胞术检测细胞周期分布,RT-PCR检测细胞周期相关基因包括细胞周期蛋白依赖性激酶4(CDK4)、CDK6、p21及p27mRNA的表达变化.结果 黄连碱可明显抑制MDA-MB-231细胞的增殖;黄连碱处理细胞后G0/G1期细胞比例减少,而S期和G2/M期细胞比例增高(P＜0.05或P＜0.01);黄连碱可上调p21 mRNA的表达、下调CDK4 mRNA和CDK6 mRNA的表达(P＜0.01),而对p27 mRNA水平无显著影响.结论 黄连碱在体外能通过诱导S期及G2/M期周期阻滞来抑制MDA-MB-231细胞的增殖;其机制可能与p21mRNA表达上调导致CDK4 mRNA及CDK6 mRNA减少有关.     

cyclinD/CDK4在肿瘤坏死因子α诱导的大鼠纤维母细胞样滑膜细胞中的表达及作用

目的探讨肿瘤坏死因子-α（TNF-α）促进滑膜细胞增殖的可能机制。方法将常规培养大鼠滑膜细胞株RSC-364细胞随机分为正常对照组和10μg/LTNF-α刺激组,分别培养6、12、24h,流式细胞术检测cyclinD1/CDK4蛋白表达;免疫细胞化学检测PCNA蛋白表达。结果TNFα作用6～24hcyclinD1和CDK4蛋白相对表达量逐渐增加,与正常对照组相比差异有统计学意义（P〈0.01）;PCNA蛋白阳性信号均表达于滑膜细胞核内,随着作用时间延长,PCNA蛋白表达增强,阳性细胞数目呈时间依赖性增多。cyclinD1和CDK4蛋白表达与PCNA的表达呈正相关（r值分别为0.683和0.496,P〈0.01）。结论TNFα可能通过上调细胞周期调控蛋白cyclinD1/CDK4的表达促进滑膜细胞的增殖和分化。     

Roscovitine对TNF-α诱导的大鼠血管平滑肌细胞增殖及细胞周期的影响

目的观察Roscovitine对TNF-α诱导的大鼠血管平滑肌细胞(VSMC)增殖及细胞周期的影响。方法组织贴块法培养大鼠VSMC细胞,采用TNF-α诱导其增殖,加入不同浓度的Roscovitine预处理15 h,将细胞分为:对照组、TNF-α组、Roscovitine 5、10、15、30μmol·L~(-1)组。MTT比色法检测细胞增殖活性;Western blot检测增殖细胞核抗原(PCNA);流式细胞仪检测细胞周期;荧光定量RT-PCR及Western blot检测细胞周期蛋白(Cyclin A、Cyclin B、Cyclin D、Cyclin E)、细胞周期蛋白依赖激酶(CDK4、CDK5)、细胞周期抑制蛋白(p53、p21、p27)的表达。结果 Roscovitine能抑制VSMC增殖;抑制细胞周期从G_0/G_1期向S期转化。与TNF-α组比较,Roscovitine 5、10、15、30μmol·L~(-1)组能降低细胞周期蛋白Cyclin A、Cyclin B、Cyclin D、Cyclin E蛋白表达,降低细胞周期蛋白依赖激酶CDK4、CDK5蛋白表达,升高细胞周期抑制蛋白p53、p21、p27蛋白表达(P<0.05)。结论 Roscovitine可抑制大鼠VSMC细胞周期进程及增殖活性。     

shRNA介导的Iduna沉默对肺癌A549细胞系细胞周期及其相关蛋白表达的影响

目的利用shRNA沉默E3泛素连接酶Iduna基因,观察Iduna对非小细胞肺癌细胞系A549细胞周期及其相关蛋白表达的影响。方法采用反转录聚合酶链反应(RT-PCR)和蛋白印迹法筛选Iduna高表达细胞系。构建shRNA-Iduna真核表达载体,瞬时转染A549细胞,蛋白印迹法检测转染效率。流式细胞仪检测细胞周期变化。蛋白印迹法检测细胞周期相关蛋白的表达。结果蛋白印迹法筛选Iduna高表达细胞系显示A549和SPC细胞中Iduna mRNA和蛋白水平高于其他细胞系。shRNA-Iduna转染A549细胞系后,流式细胞仪检测细胞周期显示干扰组G0/G1期比例增加,S期比例相对减少(P<0.05)。蛋白印迹法检测与细胞周期相关的G1/S期调控蛋白[细胞周期蛋白(cyclin)A、cyclin D1、cyclin E、CDK2、CDK4、CDK6、P21、P27、P53等]的表达情况,结果显示干扰组cyclin D1、cyclin E和CDK4蛋白表达减少(P<0.05)。结论 Iduna可能通过调控cyclin D1、cyclin E和CDK4蛋白的表达,使细胞阻滞于G0/G1期,从而调节肺癌细胞周期进程。     

细胞周期调节因子基因在H9c2心肌细胞肥大过程中的时相性表达变化

目的观察血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导H9c2心肌细胞肥大过程中细胞周期调控因子mRNA的时相性表达。方法 AngⅡ(1.0μmol·L~(-1))刺激H9c2细胞,分别于0 min、5 min、10 min、30 min、1 h、2 h、3 h、6 h、12h、24 h、48 h,罗丹明标记鬼笔环肽染色并检测细胞面积;Real-time PCR法检测细胞周期蛋白(cyclin)B、D、E,细胞周期蛋白依赖性激酶(cyclin-dependent kinases,CDK)1、2、4、6,以及CDK抑制因子p21 mRNA的表达变化情况。结果随着AngⅡ刺激时间的延长,H9c2细胞面积逐渐增大;细胞周期调节因子均于刺激后出现短暂反应性表达增加,周期蛋白E与CDK2、CDK4 mRNA在5 min时达到峰值,周期蛋白D mRNA在10 min时达到峰值,随后一直呈减少趋势;CDK6与周期蛋白B mRNA表达出现双峰现象,分别于5 min和30min达第一峰,随后表达减少,于2 h达最低点,接着又表达增加,于12 h达第二峰。p21 mRNA表达量于30 min达峰值,随后逐步减少,3 h时表达最低,之后又缓慢增加。结论AngⅡ诱导H9c2心肌细胞肥大发生的病理过程与细胞周期调控因子的震荡性表达相关,各因子共同促进细胞肥大反应。     

Affective and Anxiety Disorders and Alcohol and Drug Dependence:

Depression and anxiety frequently coexist in patients with substance use disorders. This clinically-oriented article examiens the relationship between these conditions and emphasizes data showing that substances of abuse can cause signs and symptoms of both depression and anxiety. These substance-related syndromes appear to have a different course and prognosis than uncomplicated, independent anxiety and major depressive disorders, and clinicians should consider the role of alcohol and other drugs in all patients presenting with these complaints. The authors will also outline an approach for diagnosing and managing patients with the combination of a substance use and depressive or anxiety disorder.     

Modelling and simulation of variability and uncertainty in toxicokinetics and pharmacokinetics

Two important methodological issues within the framework of the variability and uncertainty analysis of toxicokinetic and pharmacokinetic systems are discussed: (i) modelling and simulation of the existing physiologic variability in a population; and (ii) modelling and simulation of variability and uncertainty when there is insufficient or not well defined (e.g. small sample, semiquantitative, qualitative and vague) information available. Physiologically based pharmacokinetic models are especially suited for separating and characterising the physiologic variability from the overall variability and uncertainty in the system. Monte Carlo sampling should draw from multivariate distributions, which reflect all levels of existing dependencies in the intact organism. The population characteristics should be taken into account. A fuzzy simulation approach is proposed to model variability and uncertainty when there is semiquantitative, qualitative and vague information about the model parameters and their statistical distributions cannot be defined reliably.     

Synthesis and anti-nociceptive and anti-inflammatory effects of gaultherin and its analogs

The synthesis of gaultherin (1) and its analogs was carried out to provide 11 glycosides under phase-transfer catalytic conditions. The activities of all synthesized compounds were evaluated by nitric oxide production inhibitory assay in vitro. Methyl 2-O-(4-O-β-d-galactopyranosyl)-β-d-glucopyranosylbenzoate (5f) showed significantly anti-nociceptive and anti-inflammatory effects by the evaluation in vivo. Structure–activity relationships within these compounds were discussed.     

Antiinfective and encrustation-inhibiting materials--myth and facts

Catheters, urethral and ureteral stents and other urological implants are frequently affected by encrustration and infection due to their permanent contact with urine. Indwelling urinary catheters provide a haven for microorganisms and thus require extensive monitoring. Several surface modification techniques have been proposed to improve the performance of devices including the immobilization of biomolecules, the incorporation of hydrophilic grafts to reduce protein adsorption, the creation of hydrophobic surfaces, the creation of microdomains to regulate cellular and protein adhesion, new polymers and antimicrobial coatings. Physico-chemical explanation to elucidate the mechanism of such encrustation or infection inhibiting materials is still not available. Our series of experiments showed a marked decrease of silver-activity in biological fluids which corresponds with the controversial clinical results obtained with silver coated urinary catheters. Rifampicin/minocycline coated catheters had very low activity against Gram-negative rods, enterococci and Candida spp., the main causing organisms of urinary catheter infection. Surface engineered materials and antimicrobial drug delivery systems will be the next generation of sophisticated urinary catheters and stents, if both efficacy as well as efficiency has been proved clinically.     

Self-stimulation and amphetamine: Tolerance to d and l isomers and cross tolerance to cocaine and methylphenidate

The effects of the d and l isomers of amphetamine on self-stimulation responding were tested following acute and chronic administration. Tolerance and post-drug depression of responding occurred in tests with both isomers, indicating no role for p-hydroxynorephedrine (PHN) which is one of the metabolites of d-amphetamine. In the second experiment, d-amphetamine, methylphenidate and cocaine all produced quantitatively and qualitatively similar effects on self-stimulation responding following acute administration. Following chronic administration of d-amphetamine, animals showed tolerance to all three drugs, indicating cross-tolerance among them. These data are consistent with an hypothesis that tolerance and post-drug depression following chronic amphetamine treatment are the result of decreases in postsynaptic receptor sensitivity, which would lead to a decreased effectiveness of all three drugs, regardless of their pre-synaptic mechanisms.     

Interaction of estrone and estradiol with DNA and protein of liver and kidney in rat and hamster in vivo and in vitro

[6,7-³H] Estrone (E) and [6,7-³H]estradiol-17 (E₂) have been synthesized by reduction of 6-dehydroestrone and 6-dehydroestradiol with tritium gas. Tritiated E and E₂ were administered by oral gavage to female rats and to male and female hamsters on a dose level of about 300 g/kg (54 mCi/kg). After 8 h, the liver was excised from the rats; liver and kidneys were taken from the hamsters. DNA was purified either directly from an organ homogenate or via chromatin. The radioactivity in the DNA was expressed in the units of the Covalent Binding Index, CBI = (mol chemical bound per mol DNA-P)/(mmol chemical administered per kg b.w.). Rat liver DNA isolated via chromatin exhibited the very low values of 0.08 and 0.09 for E and E₂, respectively. The respective figures in hamster liver were 0.08 and 0.11 in females and 0.21 and 0.18 in the males. DNA isolated from the kidney revealed a detectable radioactivity only in the female, with values of 0.03 and 0.05 for E and E₂, respectively. The values for male hamster kidney were < 0.01 for both hormones. The minute radioactivity detectable in the DNA samples does not represent covalent binding to DNA, however, as indicated by two sets of control experiments. (A) Analysis by HPLC of the nucleosides prepared by enzyme digest of liver DNA isolated directly or via chromatin did not reveal any consistent peak which could have been attributed to a nucleoside-steroid adduct. (B) All DNA radioactivity could be due to protein contaminations, because the specific activity of chromatin protein was determined to be more than 3,000 times higher than of DNA. The high affinity of the hormone to protein was also demonstrated by in vitro incubations, where it could be shown that the specific activity of DNA and protein was essentially proportional to the concentration of radiolabelled hormone in the organ homogenate, regardless of whether the animal was treated or whether the hormone was added in vitro to the homogenate.Carcinogens acting by covalent DNA binding can be classified according to potency on the basis of the Covalent Binding Index. Values of 10³–10⁴ have been found for potent, 10² for moderate, and 1–10 for weak carcinogens. Since estrone is moderately carcinogenic for the kidney of the male hamster, a CBI of about 100 would be expected. The actually measured limit of detection of 0.01 places covalent DNA binding among the highly unlikely mechanisms of action. Similar considerations can be made for the liver where any true covalent DNA binding must be below a level of 0.01. It is concluded that an observable tumor induction by estrone or estradiol is unlikely to be due to DNA binding.Paper presented at the Satellite Symposium of the European Society of Toxicology, Rome, March 29, 1983     

Isolation and characterization of glycosylated and non-glycosylated prolactins from alligator and crocodile

Two molecular forms of prolactin (PRL). glycosylated and non-glycosylated, were isolated from pituitary glands of two reptiles, alligator and crocodile. The reptilian PRLs were extracted under alkaline conditions from the precipitate obtained after pituitaries were first extracted with 0.25 m sucrose, 1 mM NH₄HCO₃, pH 6.3. Purification was performed by ion exchange chromatography on DE-52, gel filtration on Sephadex G-75 superfine, and reversed phase high performance liquid chromatography. Two forms of both alligator and crocodile PRL, designated PRLI and PRLII, with molecular weights of 26000 and 24000 were isolated. Alligator and crocodile PRLI and PRLII were stained specifically in immunoblots with anti-sea turtle PRL and anti-ostrich PRL. Sequence analysis revealed that both forms of alligator and crocodile PRLs consisted of 199 amino acid residues with a glycosylation consensus sequence (Asn-Ala-Ser) at position 60 in alligator and crocodile PRLs with a molecular weight of 26000 (PRLI). In contrast, Thr was substituted for Asn at position 60 in the PRLs with a molecular weight of 24000 (PRLII). The sequences of alligator PRLs differed from crocodile PRLs only in position 134: Val for alligator PRLs and He for crocodile PRLs. There is a high degree of structural conservation between the reptilian PRLs isolated in this study and avian PRL; each showed 92% sequence identity with chicken PRL and 89% with turkey PRL.     

Acamprosate and naltrexone treatment effects on ethanol and sucrose seeking and intake in ethanol-dependent and nondependent rats

Rationale  Two pharmacotherapies are approved for treating alcohol craving (acamprosate and naltrexone), but both have shown mixed findings in animals and humans. Objectives  The present experiments utilized a “reinforcer blocking” approach (i.e., rats were able to consume ethanol during treatment) to better understand the efficacy of these treatments for ethanol seeking and drinking using ethanol-dependent and nondependent rats. Materials and methods  In “nondependent” experiments, drugs (acamprosate 50, 100, and 200 mg/kg; naltrexone 0.1, 0.3, and 1.0 mg/kg) were administered over 3-week periods prior to operant sessions with a low response requirement to gain access to reinforcers for 20 min. For “dependent” experiments, rats were made dependent in vapor/inhalation chambers. Results  Acamprosate and naltrexone had similar effects on intake in nondependent and dependent rats; neither drug was selective for ethanol over sucrose drinking. In nondependent animals, naltrexone was more efficacious at more doses than acamprosate, and acamprosate’s effects were limited to a dose that also had adverse effects on body weight. Both pharmacotherapies showed more selectivity when examining reinforcer seeking. In nondependent rats, acamprosate and naltrexone had response-attenuating effects in ethanol, but not sucrose, groups. In dependent animals, acamprosate had selective effects limited to a decrease in sucrose seeking. Naltrexone, however, selectively decreased ethanol-seeking in nondependent rats. Conclusions  The naltrexone-induced decreases in seeking suggested a change in incentive motivation which was selective for ethanol in nondependent rats. The “nondependent” paradigm may model early stages of “problem drinking” in humans, and the findings suggest that naltrexone could be a good intervention for this level of alcohol abuse and relapse prevention.     

Benzodiazepines,amnesia and sedation: Theoretical and clinical issues and controversies

The amnestic effect of benzodiazepines, first described in 1965, and the subsequent attempts to identify the precise nature of this effect, are reviewed. The difficulty in deciding to what extent this effect is secondary to the sedative action of these drugs is shown by the lack of agreement between studies. Nevertheless, it is concluded that, given the right experimental design, all benzodiazepines can be shown to cause an anterograde amnesia which is probably primarily a result of reduced attention or rehearsal and secondary to sedation. Its onset, degree and duration are influenced by dose, rate of absorption, route of administration, potency and the receptor occupancy rate of the particular benzodiazepine involved, but plasma elimination t_½ appears to be relatively unimportant. The clinical relevance of this for the long-term use of hypnotics and anxiolytics is not clear. Tolerance appears to be greater than for the anxiolytic but less than the sedative or anticonvulsant effect of benzodiazepines. It seems that transient amnestic effects could occur in chronic users related to post-dose, peak benzodiazepine levels. The great variability in individual response means that transient amnesia is a potential adverse drug reaction in certain individuals taking benzodiazepines.