抗肺结核药物研究进展

由于艾滋病和细菌耐药性的出现，结核病日益成为全球健康关注问题。目前迫切需要新的化学治疗药物。本文介绍一些具有抗结核分支杆菌活性的新化合物，如氟喹诺酮、恶唑烷酮、烷磺基乙酰胺和硝基咪唑类化合物的研究进展。     

硝基咪唑类放射增敏剂研究进展及其化学合成方法

放射增敏剂是一类能选择性地增加肿瘤乏氧细胞对放射敏感性的药物。它的开发和应用将大大提高肿瘤放疗的治愈率,自六十年代初以来,这类药物已取得很大进展。硝基咪唑类增敏剂发展概况 1963年Adams等提出化合物的放射增敏作用与其电子亲合性有关的论点,推动了亲电子性增敏剂的发展。其后,系统地研究了多种类型的化合物,如醌类、硝基苯类、硝基呋喃类和硝基咪唑类等,其中以硝基咪唑类作用最好。两只原为抗滴虫药的硝基咪唑类化合物,即甲硝唑(1)和米索硝唑     

硝基咪唑类抗肿瘤放射增敏剂研究进展

硝基咪唑类放射增敏剂是目前国内外研究较为成熟并具有发展前景的一类抗肿瘤放射增敏药。对几类具有代表性的硝基咪唑类化合物的化学结构、生物学活性、作用机制进行综述。     

抗结核药物的研究进展（二）

结核病仍为最具破坏性的细菌性疾病之一，发病率和死亡率都很高。结核分枝杆菌能侵入宿主免疫系统，在肺肉芽肿中持留，致使目前的抗结核药物无法杀灭菌体。近年来药物耐受以及伴有HIV感染的结核病发病率急剧增加都给结核的控制带来了很大的困难，迫切需要深入了解目前抗结核药物的作用机制及耐药机制、病菌繁殖的分子机制，以指导开发对持留菌和耐药菌更加有效的新型药物。文中介绍了近年来从现有药物中发现的具有抗结核活性的化合物，以及一些有开发潜能的抗结核药物靶点。     

抗结核药物的研究与开发

近年来结核病重新在全球肆虐，艾滋病加速了结核病的流行，对多种药物具有耐药性的结核杆菌的蔓延，迫切需要研制新的抗结核病新药。综述近二十多年来喹诺酮类、硝基咪唑类、利福霉素衍生物、氨基糖苷类、噁唑烷酮类等13类抗结核病药物的研究与开发。     

海洋抗结核分枝杆菌活性物质研究近况

近年来由于结核杆菌多重耐药菌株及人体免疫缺陷病毒双重感染的出现,使结核病的发病率和死亡率呈上升趋势,开发新的抗结核药物具有重要的社会意义和经济意义。海洋由于其独特的环境,造就了种类繁多、结构新颖多样的生物活性物质,为抗结核病的药物开发提供了广泛的前景。本综述以近年报道的抗结核分枝杆菌活性物质,包括肽类化合物,生物碱类化合物,萜类化合物等为例。简要介绍海洋活性物质的研究近况。     

抗结核药物的研究新进展

本文综述了近年抗结核药物的研究进展,分为抗结核药物的历史、现状和未来三部分,重点讲述了一些具有开发前景的喹喏酮类、硝基咪唑类、二芳基喹啉类、吡咯类、噁唑烷酮类、乙二胺类等药物,同时介绍具有开发前景的新型抗结核药物研发新领域,即脂肪酸合酶Ⅱ抑制剂、移位酶Ⅰ抑制剂及肽脱甲酰酶抑制剂,其中较有开发前景的抗结核候选药物有PA-824、OPC-67683、TMC207、LL-3858和SQ-109.     

Progress in the research of antituberculous drugs(I)

结核病仍为最具破坏性的细菌性疾病之一，发病率和死亡率都很高。结核分枝杆菌能侵入宿主免疫系统，在肺肉芽肿中持留，致使目前的抗结核药物无法杀灭菌体。近年来药物耐受以及伴有HIV感染的结核病发病率急剧增加都给结核的控制带来了很大的困难，迫切需要深入了解目前抗结核药物的作用机制及耐药机制、病菌繁殖的分子机制，以指导开发对持留菌和耐药菌更加有效的新型药物。文中综述了近年来通过天然物筛选、新药设计合成以及对现有抗结核药物的再修饰等途径，发现的一些有抗结核活性的化合物，以及结核杆菌分子生物学和抗结核治疗靶点的研究进展。     

抗结核中药成分的研究

结核病是一种传播性疾病;结核病的防治越来越受到重视。目前应用的抗结核化疗药物耐药性、副作用等问题突出,迫切需要开发新的抗结核药物。本文综述了国内外抗结核中药成分的研究情况,对研究中存在的问题作了讨论,希望有助于抗结核新药的开发。     

抗结核药物研究进展

肺结核(tuberculosis,TB)是由结核分枝杆菌(mycobacterium tuberculosis,M.tuberculosis)感染引起的,是发展中国家的重大人类疾病之一。人类免疫缺陷病毒(human immunodeficiency virus,HIV)和结核病的双重感染,以及多药耐药(multidrug-resistant,MDR)和广药耐药(extensively drug-resistant,XDR)结核分枝杆菌的出现使得抗结核的形势非常严峻,开发新型抗结核药物已经刻不容缓。鉴于形势如此迫切,研究人员开发了许多具有显著抗结核活性的化合物,其中有一些已经进入临床研究。本文对几类新型抗结核化合物的化学结构、构效关系、抗结核活性以及部分毒理性质进行了综述。     

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.     

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。     

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。     

The pathogenesis of,and pharmacological treatment for,Canavan disease

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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.