云芝糖肽聚氰基丙烯酸正丁酯纳米囊的制备工艺优选

目的 优选界面聚合法制备云芝糖肽聚氰基丙烯酸正丁酯纳米囊的工艺.方法 以包封率为指标,通过正交试验设计优化处方.结果 制得的纳米囊外观圆整,粒径分布均匀,平均粒径为268.5 nm,包封率达83.7%.结论 云芝糖肽聚氰基丙烯酸正丁酯纳米囊制备工艺简单,优选的处方较好,所制得的微囊粒径小、分布窄,该工艺可行.     

氧化苦参碱聚氰基丙烯酸正丁酯毫微粒制备工艺研究

目的优化氧化苦参碱聚氰基丙烯酸正丁酯毫微粒(OMPBCANP)的处方和制备工艺。方法以粒径、包封率和载药量为综合评价指标,通过单因素试验初选、均匀设计法精选,优化处方和制备工艺;以高效液相色谱法测定毫微粒中氧化苦参碱的含量。结果确定了最佳制备工艺为三步法,最佳处方为:氧化苦参碱50mg,聚氰基丙烯酸正丁酯0.1ml,普流罗尼克F68200mg,右旋糖苷70100mg,焦亚硫酸钠40mg;制得的氧化苦参碱毫微粒平均粒径为144.2nm,粒子圆整,载药量为17.8%,包封率为82.6%。结论优化筛选后的处方工艺,为氧化苦参碱聚氰基丙烯酸正丁酯毫微粒的最佳制备工艺。     

口蹄疫DNA疫苗聚氰基丙烯酸正丁酯纳米粒制备工艺及体外释药规律研究

目的优选制备口蹄疫DNA疫苗聚氰基丙烯酸正丁酯纳米粒(DNA-PBCA-NP)的工艺条件.方法以聚氰基丙烯酸正丁酯为载体,用乳液聚合二步法制备不同配方的DNA-PBCA-NP,采用正交设计实验法,以包封率为指标,综合分析实验结果确定工艺条件.结果优选出的制备工艺条件为:在pH值为3的条件下制备聚氰基丙烯酸正丁酯空白纳米粒,以2 mL·min-1的速度将1份口蹄疫DNA疫苗溶液滴入到5份空白纳米球乳液中,继续搅拌 8 h.运用优化的工艺条件制备的纳米粒平均粒径为(78.12±16.5)nm,分布范围为30～150 nm,平均包封率为51.25%±3.92%.体外缓释试验表明释药符合双相动力学规律.结论所确定的制备口蹄疫DNA疫苗聚氰基丙烯酸正丁酯纳米粒的工艺条件稳定、可行.     

替莫唑胺聚氰基丙烯酸正丁酯纳米粒的制备

目的:优化工艺制备替莫唑胺聚氰基丙烯酸正丁酯纳米粒(TMZ-PBCA-NP)。方法:以α-氰基丙烯酸正丁酯(BCA)为载体,采用乳化聚合法制备TMZ-PBCA-NP,并以PluronicF-68作为表面活性剂,通过考察粒径大小和包封率2个指标,在单因素实验初选的基础上,正交设计法优化处方和制备工艺。结果:制备TMZ-PBCA-NP的优化条件为反应体系pH2.5,用1%PluronicF-68作为表面活性剂,TMZ用量5 mg,BCA单体用量0.1 mL,按优化条件所制备的TMZ-PBCA-NP平均粒径(135.8±11.3)nm,多分散系数为0.19,表面电位(-24.8±2.2)mV,包封率(44.23±2.04)%,载药量(2.80±0.05)%。结论:通过优化处方和制备工艺,采用乳化聚合法可制备出TMZ-PBCA-NP,对拓展TMZ临床给药新剂型提供一定的参考。     

葛根素磷脂复合物纳米粒的制备及体外评价

目的制备葛根素磷脂复合物,以聚氰基丙烯酸正丁酯(PBCA)为载体材料,制备葛根素磷脂复合物纳米粒,并对其进行体外评价。方法采用界面缩合聚法制备纳米粒。以复合率、包封率和载药量为评价指标,通过单因素和正交试验法优选处方和工艺。结果葛根素磷脂复合物的最佳处方及工艺:反应溶剂为无水乙醇,葛根素与磷脂的投料比为1∶2;葛根素磷脂复合物纳米粒的最佳处方及工艺:pH=3.0、α-氰基丙烯酸正丁酯(α-BCA)的浓度为0.8%、V油相∶V水相=1∶60、葛根素磷脂复合物的投药量为1.0 mg。制备的纳米粒平均粒径为(115.1±3.45)nm、包封率为(90.03±1.80)%、载药量为(11.80±0.12)%。体外释药在24 h累积释放量约为80%。结论本研究所制备的葛根素磷脂复合物纳米粒包封率和载药量高、性质稳定、体外释药具有缓释行为。     

苦参碱聚氰基丙烯酸正丁酯纳米粒冻干粉针剂的制备及体外释放

采用乳化聚合法制备苦参碱聚氰基丙烯酸正丁酯纳米粒,以包封率为考察指标,均匀设计优化处方与工艺.所得纳米粒平均粒径为(157.4±22.4)nm,包封率为83.8%,载药量为9.4%,体外释药具有双相动力学特征.     

布洛芬聚氰基丙烯酸烷酯纳米粒的制备

目的制备布洛芬聚氰基丙烯酸烷酯纳米粒(IBU-PACA-NP)。方法采用乙醚界面缩聚法制备布洛芬聚氰基丙烯酸烷酯纳米粒;以包封率、载药量为指标,在单因素考察处方及工艺条件基础上,采用正交设计法L9(34)对处方进行优化。结果按优化处方制备的纳米粒平均粒径为166 nm,包封率为96.60%,载药量为17.83%,Zeta电位为-20.2 mV。结论乙醚界面缩聚法制备的布洛芬聚氰基丙烯酸烷酯纳米粒粒径小,包封率和载药量符合要求,可用于口服或注射给药。     

大蒜素聚氰基丙烯酸正丁酯纳米粒的制备工艺研究

目的：研制大蒜素聚氰基丙烯酸正丁酯纳米粒并对处方与制备工艺进行优化筛选。方法：以生物降解型聚氰基丙烯酸正丁酯为载体材料，采用乳化聚合法制备大蒜素聚氰基丙烯酸正丁酯纳米粒；以载药量、包封率、形态和粒径分布为评价指标，通过单因素试验考查、均匀设计法优化制备工艺。结果：按优化处方与制各工艺条件，制得纳米粒球形圆整、分散良好，算术平均粒径为113．4nm，粒径分布范围为11．7—146．8nm，载药量为18．57％，包封率为92．87％。结论：经优化筛选出的工艺是大蒜素聚氰基丙烯酸正丁酯纳米粒的最佳制备工艺。     

氧化苦参碱聚氰基丙烯酸正丁酯毫微粒制备工艺研究

目的 优化氧化苦参碱聚氰基丙烯酸正丁酯毫微粒（OM-PBCA-NP）的处方和制备工艺。方法 以粒径、包封率和载药量为综合评价指标，通过单因素试验初选、均匀设计法精选，优化处方和制备工艺；以高效液相色谱法测定毫微粒中氧化苦参碱的含量。结果 确定了最佳制备工艺为三步法，最佳处方为：氧化苦参碱50mg，聚氰基丙烯酸正丁酯0．1ml，普流罗尼克F68200mg，右旋糖苷．70100mg，焦亚硫酸钠40mg；制得的氧化苦参碱毫微粒平均粒径为144．2nm，粒子圆整，载药量为17．8％，包封率为82．6％。结论 优化筛选后的处方工艺，为氧化苦参碱聚氰基丙烯酸正丁酯毫微粒的最佳制备工艺。     

正交设计优选阿糖胞苷聚氰基丙烯酸正丁酯纳米粒制备工艺

目的:制备阿糖胞苷聚氰基丙烯酸正丁酯(Ara-C-PBCA-NP)纳米粒.方法:在单因素考察的基础上,通过正交设计优选处方和制备工艺,并对优化条件下制备的Afa-C-PBCA-NP胶体溶液进行质量评价.结果:制备的Ara-C-PBCA-NP平均粒径为56 nm,平均粒径跨度为1.226,载药量为11.77%,包封率为53.38%.结论:所制备的稳定的纳米粒给药系统,为阿糖胞苷的临床应用提供了更广阔的前景.     

Theoretical π-π* absorption and circular dichroic spectra of cyclic dipeptides

The dipole interaction model, treated by the partially dispersive normal mode method, is used to calculate circular dichroic spectra of cyclo(Gly-Gly), cyclo (Ala-Gly), cyclo(Ala-Ala), cyclo(Pro-Gly), cyclo(Pro-Ala), cyclo(Pro-Val), cyclo (Pro-D-Val), and cyclo(Pro-Pro) in the amide π-π* absorption band near 190 nm. Assuming a standard backbone geometry, spectra which are in fair to good agreement wth experiment are obtained for these molecules. The spectra are predicted to be sensitive to conformations of Pro and Val side chains. The effects of dipeptide ring folding on calculated CD spectra are mostly consistent with those found by other workers, except that it is found that a planar ring conformation of cyclo (Ala-Ala) and cyclo (Ala-Gly) gives predicted spectra comparable to experiment. The same model gives theoretical absorption spectra consistent with available experimental data.     

Effects of Nitro-L-Arginine on Blood Pressure and Cardiac Index in Anesthetized Rats: A Pharmacokinetic-Pharmacodynamic Analysis

Purpose. Nitric oxide synthase (NOS) inhibitors such as Nitro-L-arginine (L-NA) are being considered for the management of hypotension observed in septic shock. However, little information is available regarding the pharmacokinetic and pharmacodynamic properties of these agents. Our objective was to examine the relationships between L-NA plasma concentration and various hemodynamic effects such as cardiac index (CI), mean arterial pressure (MAP), and heart rate (HR) elicited by L-NA administration in rats. Methods. L-NA was infused at doses between 2.5 – 20 mg/kg/hr in anesthetized rats over one hour. Hemodynamic effects and plasma L-NA levels were determined. Results. Infusion of L-NA resulted in dose-dependent increases in MAP and systemic vascular resistance (SVR), decreases in CI, and minimal change in HR. The relationships between the hemodynamic effects and plasma L-NA levels were not monotonic, and hysteresis was observed. Using nonparametric analysis, the equilibration half-time (t_1/2,keo) between plasma L-NA and the hypothetical effect site was determined to be 51.5 ± 6.6 min, 42.4 ± 10.1 min, 43.4 ± 9.0 min for MAP, CI, and SVR, respectively (n = 14). The E_max and EC₅₀ values obtained were + 32.5 ± 8.4 and 2.6 ± 1.3 g/ml for MAP and –52.9 ± 15.6 and 3.7 ± 1.8 g/ml for CI, respectively. Conclusions. Although L-NA can bring about beneficial elevation of MAP, such effect is always accompanied by a stronger effect on CI depression. Dose escalation of L-NA may bring about detrimental negative inotropic effect and loss of therapeutic efficacy.     

The pathogenesis of,and pharmacological treatment for,Canavan disease

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HPLC法测定丝裂霉素C聚氰基丙烯酸正丁酯纳米粒中丝裂霉素C的含量

目的:建立高效液相色谱法测定丝裂霉素 C 聚氰基丙烯酸正丁酯纳米粒(MMC-PBCA-NP)中药物含量。方法:采用C_(18)柱(4.6 mm×150 mm,5 μm),以混合磷酸盐缓冲液-乙腈(85:15)为流动相,流速为1 mL·min~(-1),紫外检测器,检测波长为365 nm。结果:丝裂霉素 C(MMC)浓度在5～250 μg·mL~(-1)范围内与峰面积呈良好的线性关系,r=0.9998;平均回收率(n=6)为98.15%。结论:本法专属性强,操作简便,结果准确。适用于 MMC-PBCA-NP 的质量控制。     

洛美沙星体内外抗菌活性研究

洛美沙星对革兰氏阴性菌具有强的抑菌活力。对克氏肺炎杆菌的抗菌活性最强,MIC_(50)为0.12mg/L;对痢疾杆菌、产气杆菌、粘质沙雷氏菌、不动杆菌和枸椽酸杆菌的MIC_(50)分别为1和4mg/L。洛美沙星对肠细菌科细菌的活力比诺氟沙星和依诺沙星强2～16倍,明显地比丁胺卡那霉素、庆大霉素强。对金葡球菌MIC_(50)为1mg/L, MRSA对洛美沙星同样敏感。洛美沙星对表葡球菌、链球菌、粪链球菌及肺炎双球菌等的抗菌活性与地氟沙星相似,比诺氟沙星、依诺沙星、丁胺卡那霉素、庆大霉素和头孢三嗪分别强2～4倍。 洛美沙星对小鼠全身感染的疗效优于诺氟沙星。对大肠杆菌、克氏肺炎杆菌和绿脓杆菌感染小鼠iv的ED_(50)分别是0.74、0.13和3.45mg/kg, po的ED_(50)分别是0.94、1.46和6.20mg/kg。     

乙酰吉他霉素临床前药理学研究

乙酰吉他霉素对临床分离的革兰氏阳性球菌有较好的抑菌活力，其对金葡球菌、β－溶血性链球菌、表葡球菌的ＭＩＣ_（５０）分别为１、０．２２和４ｍｇ／Ｌ，对耐红霉素、青霉素的金葡球菌、表葡球菌半数以上较敏感，与吉他霉素相似，但其对革兰氏阴性菌无明显作用。乙酰吉他霉素对小鼠实验性细菌感染有明显保护作用。对金葡球菌、肺炎双球菌感染小鼠口服用药的ＥＤ_（５０）分别为７９．６和２５．１ｍｇ／ｋｇ。其疗效与吉他霉素、麦白霉素、乙酰螺旋霉素相似。乙酰吉他霉素小鼠１次口服的ＬＤ_（５０）＞１５ｇ／ｋｇ，与吉他霉素相比毒性无差异。     

大鼠溃疡性结肠炎模型的实验研究

目的对不同剂量的三硝基苯磺酸（ＴＮＢＳ）引起的大鼠溃疡性结肠炎（ＵＣ）模型进行观察和评价。方法采用一次性直肠注入大鼠ＴＮＢＳ（２５～１５０ｍｇ·ｋｇ－１）的３０％乙醇溶液，引起慢性炎症性肠疾病（ＩＢＤ），３ｗｋ后外死动物对各剂量下动物结肠的重量、髓过氧化物酶（ＭＰＯ）活性及组织形态学变化进行观察和评价。结果ＴＮＢＳ在１００～１５０ｍｇ·ｋｇ－１剂量下引起的ＵＣ肠壁明显增厚，炎症和溃疡至少维持７ｗｋ时间，ＭＰＯ活性值显著性升高，组织学检查发现粘膜及粘膜下层有大量中性粒细胞及淋巴细胞、巨噬细胞、纤维细胞浸润，肉芽组织及隐窝脓肿形成，５０ｍｇ·ｋｇ－１剂量时有一较轻度的损伤。２５ｍｇ·ｋｇ－１时对结肠的重量、ＭＰＯ活性及损伤指数都没有显著性改变（Ｐ＞０．０５）。结论用ＴＮＢＳ引起大鼠实验性ＵＣ，其溃疡和炎症维持一较长时间，这一病理特征为炎症性疾病防治药物的研究提供了条件；本模型的最佳剂量为１００ｍｇ·ｋｇ－１左右     

Protective role of exogenous α-lipoic acid (ALA) on hippocampal antioxidant status and memory function in rat pups exposed to sodium arsenite during the early post-natal period

The present work focussed on the effect of exogenous α-lipoic acid (ALA) administration on retention memory and oxidative stress markers in the hippocampus subsequent to early post-natal exposure of rat pups to sodium arsenite (NaAsO₂). Wistar rat pups were divided into the control groups receiving either no treatment (Ia) or distilled water by intraperitoneal route (i.p.) (Ib) and the experimental groups receiving either NaAsO₂ alone (1.5 and 2.0?mg/kg body wt.) (IIa, IIb) or NaAsO₂ (1.5 and 2.0?mg/kg body wt.) followed by ALA (70?mg/kg body wt.) (IIIa, IIIb) (i.p.) from post-natal day (PND) 4–15. The initial and retention transfer latency (ITL and RTL) was determined on PND 14 and 15 using elevated plus maze. The animals were sacrificed by cervical decapitation (PND 16) and the brains were obtained. The dissected out hippocampus was processed for estimation of oxidative stress markers, glutathione (GSH), and superoxide dismutase (SOD). NaAsO₂ exposure resulted in longer RTL in animal groups IIa and IIb, thereby suggestive of arsenic-induced impairment in retention memory. RTL was significantly shorter in animal groups (IIIa, IIIb) receiving ALA following NaAsO₂, thereby suggestive of improvement in retention memory. GSH and SOD levels were significantly decreased in animals receiving NaAsO₂ alone as against group Ib and administration of ALA following NaAsO₂ increased the levels of hippocampal GSH and SOD. These observations are suggestive of the role of exogenous ALA in ameliorating the adverse effects induced by NaAsO₂ exposure of rat pups on retention memory and oxidative stress markers.     

Dinoflagellate polyether within the yessotoxin, pectenotoxin and okadaic acid toxin groups: Characterization, analysis and human health implications

Diarrhetic Shellfish Poisoning (DSP) is a specific type of food poisoning, characterized by severe gastrointestinal illness due to the ingestion of filter feeding bivalves contaminated with a specific suite of toxins. It is known that the problem is worldwide and three chemically different groups of toxins have been historically associated with DSP syndrome: okadaic acid (OA) and dinophysistoxins (DTXs), pectenotoxins (PTXs) and yessotoxins (YTXs). PTXs and YTXs have been considered as DSP toxins because they can be detected with the bioassays used for the toxins of the okadaic acid group, but diarrhegenic effects have only been proven for OA and DTXs. Whereas, some PTXs causes liver necrosis and YTXs damages cardiac muscle after intraperitoneal injection into mice. On the other hand, azaspiracids (AZAs) have never been included in the DSP group, but they cause diarrhoea in humans. This review summarizes the origin, characterization, structure, activity, mechanism of action, clinical symptoms, method for analysis, potential risk, regulation and perspectives of DSP and associated toxins produced by marine dinoflagellates.     

Latent role of in vitro Pb exposure in blocking Aβ clearance and triggering epigenetic modifications

Both β-amyloid (Aβ) catabolism and epigenetic regulation play critical roles in the onset of neurodegeneration. The latter also contribute to Pb neurotoxicity. The present study explored the role of epigenetic modifiers and Aβ degradation enzymes in Pb-induced latent effects on Aβ overproduction in vitro. Our results indicated that in SH-SY5Y cells exposed to Pb, the expression of NEP and IDE remained declined during the recovery period, accompanied with abnormal increase of Aβ_1-42 and amyloid oligomer. A disruption of selective global post-translational histone modifiers including the decrease of H3K9ac and H4K12ac and the induction of H3K9me2 and H3K27me2 dose dependently was also showed in recovery cells. Moreover, histone deacetylase inhibitor VPA could attenuate latent Aβ accumulation and HDAC activity induced by Pb, which might be by regulating the expression of NEP and IDE epigenetically. Overall, our results suggest sustained reduction of NEP and IDE expression in response to Pb sensitizes recovery SH-SY5Y cells to Aβ accumulation; however, administration of VPA is demonstrated to be beneficial in modulating Aβ clearance.