L-肌肽对鱼藤素诱导SH-SY5Y细胞神经毒性的保护作用

目的研究L-肌肽是否能通过抗氧化活性降低鱼藤素导致的神经毒性。方法 SH-SY5Y细胞在L-肌肽(1、10、20、40、60、80、100 mmol·L~(-1))中培养24 h,CCK-8法测定细胞存活率。30 mmol·L~(-1) L-肌肽、20μmol·L~(-1)鱼藤素、20μmol·L~(-1)鱼藤素与30 mmol·L~(-1) L-肌肽作用于SH-SY5Y细胞24 h,AO/EB法检测细胞形态和凋亡情况。8μmol·L~(-1)鱼藤素、8μmol·L~(-1)鱼藤素与3 mmol·L~(-1) L-肌肽、8μmol·L~(-1)鱼藤素与30 mmol·L~(-1) L-肌肽、20μmol·L~(-1)鱼藤素、20μmol·L~(-1)鱼藤素与3 mmol·L~(-1) L-肌肽、20μmol·L~(-1)鱼藤素与30 mmol·L~(-1) L-肌肽、50μmol·L~(-1)鱼藤素、50μmol·L~(-1)鱼藤素与3 mmol·L~(-1) L-肌肽、50μmol·L~(-1)鱼藤素与30 mmol·L~(-1) L-肌肽作用于SH-SY5Y细胞24 h,CCK-8法检测细胞的增殖情况;双染流式细胞术检测细胞凋亡率;DCFH-DA流式细胞术检测细胞活性氧(ROS)水平。结果 20μmol·L~(-1)鱼藤素与30 mmol·L~(-1) L-肌肽共作用于细胞后,细胞抑制率降低9.07%,早期凋亡的细胞数减少,早期凋亡率降低9.35%,总凋亡率降低10.7%,ROS水平低于20μmol·L~(-1)鱼藤素组,结果差异具有统计学意义(P<0.05)。结论 L-肌肽能有效降低鱼藤素诱导SH-SY5Y细胞的神经毒性,保护细胞,其机制可能与降低氧化应激水平相关。     

格列本脲蛋白结合作用的HPLC-FA法研究

目的:建立高效液相色谱-迎头分析法(HPLC-FA)研究格列本脲与人血清白蛋白(HSA)的结合作用。方法:采用HPLC-FA法,色谱柱为 Pinkerton GFFⅡ-S5-80(150 mm×4.6 mm,5 μm),流动相为67 mmol·L~(-1)磷酸盐等渗缓冲液(pH 7.4,I=0.17 mol·L~(-1)),流速0.2 mL·min~(-1),检测波长230 nm,进样量900μL,柱温37℃。结果:应用非线性回归参数估算求得 HSA 分子上两类结合位点结合的格列本脲分子数及相应的结合平衡常数:n_1,=1.5和 K_1=1.1(μmol·L~(-1))~(-1);n_2=3.8和 K_2=0.012(μmol·L~(-1))~(-1)。结论:HPLC-FA 法操作简便,适用于研究格列本脲与 HSA 的结合作用。本实验选定的进样体积为900μL。     

高效毛细管电泳法测定盐酸芦氟沙星制剂的含量

目的:建立一种高效毛细管电泳(HPCE)分析方法,用于盐酸芦氟沙星制剂的含量测定,并与高效液相色谱法(HPLC)进行比较。方法:以75μm×365μm(总长62 cm,有效长度53.5 cm)熔融石英毛细管为分离通道,20 mmol·L~(-1)硼酸盐-25mmol·L~(-1)磷酸盐缓冲液(pH 8.7)为电泳缓冲液,运行电压18 kV,柱温28℃,紫外检测波长295 nm;分别采用外标法和内标法定量,HPLC 法采用外标法定量。结果:外标法:盐酸芦氟沙星在1.4×10~(-6)～5.7×10~(-5)mol·L~(-1)浓度范围内线性关系良好(r=0.9997),检测限5×10~(-7)mol·L~(-1),定量限1.4×10~(-6)mol·L~(-1),日内和日间峰面积的 RSD 分别为1.02%～1.73%和1.90%～3.84%,加样回收率为99.6%(98.5%～100.5%,胶囊)和99.4%(98.6%～100.1%,片剂);内标法:盐酸芦氟沙星在1.6×10~(-6)～1×10~(-4)mol·L~(-1)浓度范围内线性关系良好(r=0.9997),检测限5.1×10~(-7)mol·L~(-1),定量限1.6×10~(-6)mol·L~(-1),日内和日间药物峰面积与内标峰面积之比的 RSD 分别为0.84%～1.33%和1.83%～2.40%,加样回收率为100.3%(99.2%～102.0%,胶囊)和99.5%(99.4%～99.6%,片剂)。结论:所建立的 HPCE 法简便、快速、经济,外标法和内标法测定结果准确度高、重复性好,且与 HPLC 法测定结果一致,均可作为盐酸芦氟沙星胶囊和片剂的质量控制方法。     

聚结晶紫薄膜修饰电极对氧氟沙星的电催化作用

目的:利用循环伏安法电聚合制备出对氧氟沙星(OFX)具有良好电催化作用的聚结晶紫薄膜修饰电极(PCVE),建立一种对 OFX 进行定量测定的新的电化学分析方法。方法:在0.050 mol·L~(-1)硫酸钠溶液 0.08 mol·L~(-1)。醋酸-醋酸钠缓冲液(pH=4.4)体系中,于0.4～1.2 V 范围内,以100 mV·s~(-1)的扫描速率进行循环伏安分析。结果:氧氟沙星的线性范围为1.6×10~(-7)～2.0×10~(-4)mol·L~(-1),r=0.9995,检测限可达8.0×10~(-9)mol·L~(-1)。样品分析的 RSD 均小于2%(n=8),回收率为95.7%～102.1%。结论:PCVE 制备简单、稳定性好。该方法是一种灵敏、准确测定样品中微量 OFX 的新的电化学分析方法。     

大鼠胆汁中酮洛芬Ⅱ相代谢物酮洛芬葡萄糖醛酸的测定方法

目的:建立 RP-HPLC 法测定胆汁中酮洛芬Ⅱ相代谢物酮洛芬葡萄糖醛酸(S-KPG、R-KPG)。方法:采用 ODS 柱(5μm,4.6 mm×250 mm);流动相为乙腈-水(35:65),内含0.05 mol·L~(-1)磷酸二氢钾和0.005 mol·L~(-1)的四丁基溴化胺,pH5.6;流速为1 mL·min~(-1);检测波长232 nm;柱温30℃;进样是20μL。内标为10 mg·L~(-1)的萘普生甲醇溶液。结果:在2～1000μmol·L~(-1)浓度范围内,胆汁中 S-KPG、R-KPG 回归方程分别为 Y=0.0039X-0.0256,r=0.9998和 Y=0.0039X-0.0229,r=0.9998;最低检测限分别为0.5 μmol·L~(-1)和1 μmol·L~(-1)。S-KPG 和 R-KPG 在室温和胆汁生理 pH 时不稳定,在 pH4时最稳定。结论:本文应用 RP-HPLC 检测胆汁 S-KPG、R-KPG,方法简便、易行、实用,可以作为肝脏葡萄糖醛酸转移酶活性和胆排泄实验研究的分析手段。     

液相色谱-质谱联用法测定人血浆中卢比替康的浓度

目的建立液相-质谱(LC-MS)联用方法,用于抗肿瘤药卢比替康在肿瘤患者血浆中的定量分析。方法血浆样品用0.2 mL盐酸(0.5 mol·L~(-1))酸化后,乙酸乙酯提取,上清液在40℃水浴条件下氮气流吹干,萃取物用流动相复溶后进LC-MS联用仪分析测定。采用反相C_(18)柱进行色谱分离,流动相为:乙腈:10 mmol·L~(-1)醋酸铵水溶液(90:10,V/V)。结果本方法在5～500μg·L~(-1)内线性良好,r=0.999 4(n=4),低、中、高3种浓度质控样品的批内及批间RSD均<5%,提取回收率分别为80.66%、88.47%、85.05%,最低定量限5μg·L~(-1)。结论本方法灵敏度高,操作简便易行,能够满足该药进行临床药动学研究的要求。     

胶束电动毛细管电泳法分离6种生物碱基

目的:采用胶束电动毛细管电泳法(MECC)分离腺嘌呤(A)、鸟嘌呤(G)、胞嘧啶(C)、胸腺嘧啶(T)、茶碱和咖啡因6种生物碱基。方法:20℃、18 kV 应用电压下,检测波长270 nm,在 35 mmol·L~(-1)十二烷基硫酸钠(SDS)-10 mmol·L~(-1)硼砂(pH 9.0)运行缓冲液中电泳分离。结果:6种碱基8 min 内达到基线分离;在10～500 mg·L~(-1)浓度范围内呈良好线性关系;相关系数为0.9995～0.9999;检出限为12.5～100μg·L~(-1),加样回收率在96.1%～105.2%。并用于3种药物和茶叶中生物碱基含量的测定。结论:方法简便、快速,灵敏度高,可用于分析和测定含生物碱基的药物和饮料。     

对乙酰氨基酚在多壁碳纳米管修饰电极上的电化学行为及其测定

目的:研究对乙酰氨基酚(ACOP)在多壁碳纳米管(MWCNTs)修饰电极上的伏安行为,建立测定 ACOP 含量的电化学分析新方法。方法:采用循环伏安法研究 ACOP 在 MWCNTs 修饰电极上的电化学行为及其含量测定方法。结果:MWCNTs 修饰电极对 ACOP 有明显的电催化作用。在 pH 4.8醋酸盐缓冲液中,氧化峰电流与 ACOP 浓度在2.0×10~(-2)～10.0μmol·L~(-1)范围内呈良好的线性关系,检测限为2.0×10~(-3)μmol·L~(-1)。结论:MWCNTs 修饰电极可有效消除制剂中其他组分对 ACOP 测定的干扰,用于实际样品中 ACOP 含量的直接测定,回收率在98.1%～100.3%之间。该方法灵敏度高、检测范围宽,结果令人满意。     

高效液相色谱法测定果蔬中残留的噻苯咪唑、邻苯基苯酚及联苯

目的:建立同时测定果蔬中残留的噻苯咪唑(TBZ)、邻苯基苯酚(OPP)及联苯(DP)的 HPLC 法,并对乌鲁木齐地区部分高档水果中保鲜剂的残留状况进行初步评估。方法:在碱性条件下,用乙醚提取果蔬中 TBZ、OPP 及 DP 3种保鲜剂,以甲醇-乙腈-5 mmol·L~(-1)十二烷基磺酸钠溶液(磷酸调 pH:4.5)(55:10:35)为流动相,流速1.0 mL·min~(-1),荧光检测(λ_(ex)=285nm,λ_(em)=320 nm),进样量10μL。结果:TBZ、OPP 及 DP 的线性范围分别为0.01～8,0.007～10,0.01～20μg·mL~(-1);相关系数均大于0.999;最低检测限分别为0.01,0.007,0.01 μg·mL~(-1);平均回收率为71.4%～93.2%;RSD 为0.6%～6.5%。结论:本实验建立的 HPLC-荧光检测,方法准确可靠,适合于果蔬中噻苯咪唑、邻苯基苯酚及联苯残留的测定。     

HPLC法同时测定人血浆中5-氟尿嘧啶及其活性代谢物5-氟-2′-脱氧尿嘧啶核苷的浓度

目的:建立一种同时测定人体血浆中5-氟尿嘧啶及其活性代谢物5-氟-2′-脱氧尿嘧啶核苷浓度的HPLC法。方法:以肌苷为内标,血浆样品用硝酸银(10%)沉淀蛋白质,采用C_(18)柱,检测波长为266nm,流动相:0.01mol·L~(-1)磷酸盐(用2mol·L~(-1)氢氧化钠溶液调pH为7.0)-甲醇(96∶4),流速1.0mL·min~(-1),柱温为45℃。结果:5-氟尿嘧啶和5-氟-2′-脱氧尿嘧啶核苷分别在0.1～20μg·mL~(-1)(r=0.9997)和0.2～40μg·mL~(-1)(r=0.9997)浓度范围内线性关系良好,最低检测浓度分别为5和10ng·mL~(-1),方法回收率分别为98.2%～101.2%、99.5%～102.3%,日内、日间RSD均小于6%。结论:方法灵敏、快速、准确,适用于临床上测定5-氟尿嘧啶及其活性代谢物5-氟-2′-脱氧尿嘧啶核苷的血药浓度及药动学的研究。     

反相高效液相色谱法测定藿香正气胶囊中厚朴酚及和厚朴酚的含量

目的 建立藿香正气胶囊中厚朴酚及和厚朴酚的含量测定方法。方法 反相高效液相色谱法测定藿香正气胶囊中厚朴酚及和厚朴酚的含量。选用ODS hypersil C—18反相色谱柱：以甲醇-乙腈-水（5：2：4）为流动相;检测波长294nm。结果 此方法线性关系良好（r=1．000）,平均回收率99．95％。结论 此方法简便,快速,准确,可用于藿香正气胶囊中厚朴酚及和厚朴酚的含量测定。     

The effect of halothane on the stability of Ca2+ transport activity of isolated fragmented sarcoplasmic reticulum

The effects of the inhalation anaesthetic agent, halothane (CF₃CHBrCl), on the stability of the calcium transport system of isolated rabbit white skeletal muscle sarcoplasmic reticulum have been studied. Calcium transport activity was unaffected when suspensions of sarcoplasmic reticulum vesicles were preincubated at 37° and pH 6.8 at concentrations of halothane below 5 mM, but was progressively inactivated at higher concentrations. (Ca²⁺,Mg²⁺)-ATPase activity was enhanced during inactivation of calcium transport. At pH 6.3 and 5.8, halothane increased the first order rate constants of inactivation and effects were noted in the anaesthetic range of concentration (1–2 mM). The inulin inaccessible space of membrane vesicles did not change appreciably during the period of treatment with halothane, excluding increased permeability as an explanation of the inhibition of calcium accumulation. Inactivation was irreversible and highly temperature dependent, with an activation energy of 52.7 kcal/mol. Calcium ions had a protective effect against inactivation (K_{0.5 (Ca2+) = 1.5 × 10^?6M}), as did ATP ($\text{K}{}_{\mathrm{<mtext>0.5\; (</mtext><mtext>Atp</mtext><mtext>)</mtext>}}\text{? 10}{}^{\mathrm{?6}}\text{M}$). It is concluded that mild acid conditions and halothane act synergistically during inactivation of the calcium transport system of sarcoplasmic reticulum membranes. These studies suggest that halothane interacts with the (Ca²⁺, Mg²⁺)-ATPase protein at the ATP-specific binding site or that it disrupts protein-lipid associations in the membrane. In either case the destabilizing effect of halothane may be modified by the conformational state of the protein.     

含RGD和YIGSR的肽合成及其抗肿瘤侵袭活性

目的:设计并合成具有抗肿瘤侵袭活性的含Arg-Gly-Asp(RGD)和Tyr-Ile-Gly-Ser-Arg(YIGSR)新型肽类化合物.方法:RGD和YIGSR均有抗肿瘤侵袭活性,在此基础上设计了α-精甘天冬氨酰-ε-酪异亮甘丝精氨酰赖氨酸甲酯,并采用固相法合成.观察其对小鼠肺腺癌细胞自发肺转移模型抗肿瘤转移的影响.结果:目标化合物总收率56%,结构经质谱鉴定.静脉给药每只100μg,5次可显著抑制移植LA795细胞肺转移小鼠的肺脏重量和肺转移结节数.结论:目标化合物具有较强的抗肿瘤侵袭活性.     

Analysis of phthalate esters in two different baby care products available in United Arab Emirates

Phthalates are used as plasticizers in a wide range of products and are known to affect the human health adversely. Hence, the present study was carried out to identify and quantify the presence of four phthalates namely dimethyl phthalate (DMP), dibutyl phthalate (DBP), and diethyl phthalate (DEP), di (2-ethylhexyl) phthalate (DEHP) in the two baby products i.e. baby oils and baby lotions. The daily exposure levels and hazard index of each phthalate were also calculated. It was an analytical study where two different brands of samples of baby oil and baby lotion each, from the date of manufacturing of 3, 10, and 20?months were collected. The extraction of phthalates from different samples was done and analyzed using HPTLC. Results showed the presence of all four phthalates, although some phthalates were not present in 3?M samples. The maximum concentration of all the phthalates was found in 20?M samples. Their concentration increased with the storage time indicating the possibility of leaching and migration of phthalates from the container into the product. The hazard indices for phthalates estimated for baby oil and baby lotion were found below 1, which denotes that the daily phthalate exposures are within the regulatory limits. It is important to consider that the exposure to phthalates can occur not only by dermal contact of these baby products but also through other routes. Hence, the study signifies the importance of phthalates concentration in such regularly used products.     

曲马朵对大鼠吗啡辨别行为的影响(英文)

AIM: To study the potential of the psychological dependence of tramadol. METHODS: Rats were trained to discriminate 4.0 mg/kg morphine, and to discriminate 0.5 mg/kg methamphetamine (MA) from saline under a fixed-ratio (FR10) schedule of reinforcement. After they acquired the discrimination, different doses of tramadol were used to substitute for training dose of morphine and MA. Naltrexone was injected concomitantly with tramadol. RESULTS: Tramadol fully substituted morphine at a dose of 32 mg/kg or higher. The ED50 value of the discriminative effects of tramadol was 20.94 mg/kg, higher than that of morphine (2.04 mg/kg, P < 0.01). MA failed to generalize to tramadol at the doses tested. Naltrexone antagonized the discriminative response of tramadol. CONCLUSION: Tramadol can substitute for morphine in morphine discriminative rats. The discriminative stimulus effects of tramadol are mediated by a mu opioid mechanism.     

Identification and Assessment of Tumor-Promoting and Cocarcinogenic Agents: State-of-the-Art in Vitro Methods

Abstract

Chemical-analytical studies during the past 4 years led to several new observations on the formation of tobacco-specificN-nitrosamines (TSNA) and their occurrence in smokeless tobacco, mainstream smoke (MS), and sidestream smoke (SS) of American and foreign cigarettes. When snuff was extracted by means of supercritical fluid extraction with carbon dioxide containing 10% methanol, analysis of this material confirmed that the extraction with organic solvents had been partially incomplete.

Epidemiological studies in the northern Sudan showed a high risk for oral cancer for users of toombak, a home-made oral snuff. Toombak contains 100-fold higher levels of TSNA than commercial snuff in the U.S. and Sweden. The TSNA content in the saliva of toombak dippers is at least ten times higher than that reported in the saliva of dippers of commercial snuff. Biomarker studies have shown corresponding high levels of hemoglobin adducts with metabolites of NNN and NNK as well as for urinary metabolites of NNK. These data supported the epidemiological findings.

The analyses of MS of U.S. and foreign cigarettes smoked under FTC conditions revealed comparable data for the smoke of nonfilter cigarettes and filter cigarettes except in the case of low- and ultralow-yield cigarettes, which showed reduced TSNA yields. The MS of cigarettes made from Burley or dark tobacco is exceptionally high in TSNA, primarily because of the high nitrate content of those tobacco types. Taking puffs of larger volume and drawing puffs more frequently, practices observed among most smokers of cigarettes with low nicotine yield, results in high TSNA values in the MS. The formation of the lung carcinogen NNK is favored during the smoldering of cigarettes, between puffs, when SS is generated. Consequently, in most samples from indoor air polluted with environmental tobacco smoke (ETS), the highest concentration of an individual TSNA is that of NNK. When nonsmokers had remained for up to 2 h in a test laboratory with high ETS pollution, they excreted measurable amounts of NNK metabolites in the urine, indicative of the uptake of TSNA.     

The Use of a Microfluidic Device to Encapsulate a Poorly Water-Soluble Drug CoQ10 in Lipid Nanoparticles and an Attempt to Regulate Intracellular Trafficking to Reach Mitochondria

A number of drugs that are currently on the market, as well as new candidates for drugs, are poorly water soluble. Because of this, a need exists to develop drug formulations that will permit the expanded use of such drugs. The use of liposomes and lipid nanoparticles for drug delivery has attracted attention as a technique for solubilizing molecules that are poorly water soluble, but this technique faces serious scale-up risks. In this study, we report on attempts to encapsulate Coenzyme Q₁₀ (CoQ₁₀) as a model of a poorly water-soluble drug in an MITO-Porter, a liposome for mitochondrial delivery using a microfluidic device (a CoQ₁₀-MITO-Porter [μ]). The physical properties of the CoQ₁₀-MITO-Porter [μ] including homogeneity, size, and preparation volume were compared with those for a CoQ₁₀-MITO-Porter prepared by the ethanol dilution method (a CoQ₁₀-MITO-Porter [ED]). In the case where a microfluidic device was used, a small-sized CoQ₁₀-MITO-Porter was formed homogeneously, and it was possible to prepare it on a large scale. Intracellular observations using HeLa cells showed that the CoQ₁₀-MITO-Porter [μ] was efficiently internalized by cells to reach mitochondria. These results indicate that the CoQ₁₀-MITO-Porter [μ] represents a potential candidate for use in mitochondrial nanomedicine.     

Di(2-ethylhexyl)phthalate (DEHP) metabolites in human urine and serum after a single oral dose of deuterium-labelled DEHP

Human metabolism of di(2-ethylhexyl)phthalate (DEHP) was studied after a single oral dose of 48.1 mg to a male volunteer. To avoid interference by background exposure the D4-ring-labelled DEHP analogue was dosed. Excretion of three metabolites, mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP), mono(2-ethyl-5-oxohexyl)phthalate (5oxo-MEHP) and mono(2-ethylhexyl)phthalate (MEHP), was monitored for 44 h in urine and for 8 h in serum. Peak concentrations of all metabolites were found in serum after 2 h and in urine after 2 h (MEHP) and after 4 h (5OH-MEHP and 5oxo-MEHP). While the major metabolite in serum was MEHP, the major metabolite in urine was 5OH-MEHP, followed by 5oxo-MEHP and MEHP. Excretion in urine followed a multi-phase elimination model. After an absorption and distribution phase of 4 to 8 h, half-life times of excretion in the first elimination phase were approximately 2 h with slightly higher half-life times for 5OH- and 5oxo-MEHP. Half-life times in the second phase—beginning 14 to 18 h post dose—were 5 h for MEHP and 10 h for 5OH-MEHP and 5oxo-MEHP. In the time window 36 to 44 h, no decrease in excreted concentrations of 5OH- and 5oxo-MEHP was observed. In the first elimination phase (8 to 14 h post dose), mean excretion ratios of MEHP to 5oxo-MEHP and MEHP to 5OH-MEHP were 1 to 1.8 and 1 to 3.1. In the second elimination phase up to 24 h post dose mean excretion ratios of MEHP to 5oxo-MEHP to 5OH-MEHP were 1 to 5.0 to 9.3. The excretion ratio of 5OH-MEHP to 5oxo-MEHP remained constant through time at 1.7 in the mean. After 44 h, 47% of the DEHP dose was excreted in urine, comprising MEHP (7.3%), 5OH-MEHP (24.7%) and 5oxo-MEHP (14.9%).     

油茶皂苷抗心肌缺血大鼠氧自由基和脂质过氧化作用

目的　以皮下注射异丙肾上腺素 (ISO)诱发大鼠心肌损伤为模型 ,观察油茶皂苷 (SQS)对心肌线粒体MDA含量、SOD、GSH Px活性的影响。方法　实验分生理盐水组 (NS组 )、ISO诱发损伤组 (I/R组 )、SQSⅠ组 (I/R +SQS 0 1mg·kg-1)和SQSⅡ组 (I/R +SQS 0 2mg·kg-1)。从阴茎静脉注射各被试药物或NS ,每天 1次 ,连续 3d。末次给药后取心肌组织行上述指标的测定。结果　I/R组MDA含量明显升高、SOD及GSH Px活性显著降低 ;SQS能对抗ISO所致上述指标的改变 ,且呈剂量依赖关系。结论　SQS具有抗ISO所致大鼠心肌缺血时氧自由基和脂质过氧化作用