硫化氢合成酶抑制剂金丝桃素的体内外抗结肠癌作用研究

为研究金丝桃素对硫化氢合成酶活性的影响,探索金丝桃素作为胱硫醚-β-合成酶(CBS)抑制剂的体内外抗结肠癌作用。本研究通过亚甲蓝法测定金丝桃素和氨基氧乙酸(AOAA)对CBS产H2S活性的抑制作用,以HT29人结肠癌细胞和移植HT29细胞的裸鼠肿瘤模型为抗肿瘤研究对象,测定金丝桃素体内外抗肿瘤作用。结果表明,来源于贯叶连翘(Hypericum perforatum L.)的化合物金丝桃素是CBS的高效选择性抑制剂,其IC50为7.9±1.42μmol/L。金丝桃素能显著抑制HT29人结肠癌细胞的增殖,其IC50为22.2±2.25μmol/L。基因沉默实验表明CBS蛋白可能是金丝桃素在细胞内的潜在靶标之一。意外的是,目前普遍使用的CBS抑制剂AOAA抑制HT29细胞增殖作用非常弱,其IC50为152.5±35.68μmol/L。此外,不同剂量的金丝桃素(5~30mg/kg·d)均能显著减少裸鼠肿瘤体积和重量,30mg/kg·d剂量皮下给药2周后,和对照组相比肿瘤重量减少了68%。以上结果表明金丝桃素作为CBS的选择性抑制剂具有显著的抗结肠癌作用。     

桂皮醛衍生物的合成及其对CVB_3的作用

目的：合成桂皮醛衍生物,观测其对心肌细胞的毒性及抗CVB3病毒的作用。方法：化学合成6种桂皮醛衍生物,其中3种进行了红外、质谱等结构表征;MTT法检测被CVB3病毒感染和用桂皮醛衍生物治疗后的心肌细胞活性。结果：α-溴代对氯肉桂醛、α-溴代对甲基肉桂醛、对氯肉桂醛3种桂皮醛衍生物对心肌细胞的半数毒性浓度（TC50）分别为2151.28μg·mL-1,1475.32μg·mL-1,22460.32μg·mL-1;对CVB3病毒的半数抑制浓度（IC50）分别为178.94μg·mL-1、173.35μg·mL-1、6045.25μg·mL-1;对CVB3病毒的治疗指数（TI）分别为12.02,8.51,3.71。结论：桂皮醛3种衍生物具有直接抑制CVB3病毒作用,但对病毒的细胞合成和吸附无明显作用。     

桂皮醛衍生物的合成及其对CVB3的作用

目的:合成桂皮醛衍生物,观测其对心肌细胞的毒性及抗CVB3病毒的作用.方法:化学合成6种桂皮醛衍生物,其中3种进行了红外、质谱等结构表征;MTT法检测被CVB3病毒感染和用桂皮醛衍生物治疗后的心肌细胞活性.结果:α-溴代对氨肉桂醛、α-溴代对甲基肉桂醛、对氯肉桂醛3种桂皮醛衍生物对心肌细胞的半教毒性浓度(TC50)分别为2151.28μ g·mL-1,1475.32μg·mL-1,22460.32μ g·mL-1;对CVB3病毒的半数抑制浓度(IC50)分别为178.94μg·mL-1、173.35μg·mL-1,6045.25μg·mL-1;对CVB3病毒的治疗指数(TI)分别为12.02,8.51,3.71.结论:桂皮醛3种衍生物具有直接抑制CVB3病毒作用,但对病毒的细胞合成和吸附无明显作用.     

合欢皮提取物抑制血管生成作用的研究

本文采用体外细胞培养法和体内鸡胚尿囊绒膜模型、荷瘤模型检测合欢皮提取物抑制人微血管内皮细胞(HMEC-1)的增殖、迁移活性,观察合欢皮提取物的抑制血管生成情况。发现合欢皮提取物能显著抑制HMEC-1的增殖(IC50为30μg/mL)和迁移,并且呈明显的剂量依赖性。在体内同时具有抑制鸡胚尿囊膜和肿瘤组织中血管生成的作用。     

绞股蓝皂苷对PC12细胞增殖及细胞损伤模型的保护作用

本文通过采用四氮唑蓝(MTT)比色法检测绞股蓝皂苷对PC12细胞增殖活力的影响,并用低糖低血清、谷氨酸、β淀粉样蛋白(Aβ25~35)诱导PC12细胞制备细胞损伤模型,观察绞股蓝皂苷低(50μg·mL~(-1))、中(200μg·mL~(-1))、高(500μg·mL~(-1))剂量在3种细胞损伤模型中对细胞存活率和胞浆中乳酸脱氢酶(LDH)释放量的影响。结果表明,绞股蓝皂苷能显著提高正常PC12细胞的存活率,并能有效对抗低糖低血清、谷氨酸、β淀粉样蛋白引起的细胞凋亡,降低胞浆中乳酸脱氢酶(LDH)的释放量。     

灵芝醇溶酸性组分的抗肿瘤作用

本文探讨了灵芝醇溶酸性组分(ethanol-soluble and acidic components,ESAC)的抗肿瘤作用。用溶剂提取法从灵芝精粉中提取ESAC并利用高效液相色谱对其主要成分进行分析。利用MTT法检测ESAC对3种细胞系(人肝癌系BEL7402、人宫颈上皮癌细胞系HeLa和人脐静脉血管内皮细胞系HUVEC)体外生长的影响。同时通过腹腔注射给药测定ESAC对BEL7402瘤株在裸鼠皮下生长的影响。结果显示,ESAC对3种细胞的毒性有较大差异,IC50值分别为12．4μg／mL(BEL7402)、129．2μg／mL(HeLa)和526．6μg／mL(HU-VEC)。动物实验表明,20mg／kg／d ESAC组的肿瘤抑制率为43．9％,而5mg／kg／d组的肿瘤抑制率高达74．9％,且毒副作用较小。本文结果提示,灵芝ESAC组分对肝癌生长有一定的选择性抑制作用。     

反相高效液相色谱法直接检测芳香族氨基酸

用反相高效液相色谱-变波长紫外检测法直接测定了芳香族氨基酸。流动相为磷酸盐缓冲溶液(pH6)和甲醇的混合溶液,其体积配比为7030,流速为0.6ml/min,变波长紫外检测,10min内完成。酪氨酸、苯丙氨酸、色氨酸的线性范围分别为50～500μg·mL-1、200～20000μg·mL-1、20～2000μg·mL-1,三者的检测限分别为10μg·mL-1、150μg·mL-1、5μg·mL-1。     

氯化镧对雄性小鼠精子质量及睾丸酶活力的影响

探讨氯化镧对小鼠精子质量及睾丸细胞酶的影响。40只成年昆明种雄性小鼠随机分成对照组、低(25mg·kg-1)、中(50mg·kg-1)、高(100mg·kg-1)剂量组,腹腔注射1次/4d,饲养35d。测定睾丸和附睾脏器指数,检测并计算精子数量、活精率、活动率和畸形率以及睾丸碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、乳酸脱氢酶(LDH)、一氧化氮合酶(NOS)活力。结果显示,高剂量氯化镧降低了小鼠睾丸AKP活力,抑制了精子数量和质量;中剂量氯化镧能促进NOS活力,使精子数量减少,对精子质量造成损伤。     

人骨骼肌肌钙蛋白C在大肠杆菌中的表达及其抗肿瘤作用

为了探索重组人骨骼肌型肌钙蛋白C(rhTnC)的抗肿瘤作用,采用PCR技术,从人乳腺cDNA文库中获得编码TnC的cDNA序列,在大肠杆菌中进行了表达.经镍柱亲和层析纯化后,分别检测其在体外对人脐静脉内皮细胞生长的抑制作用与对小鼠异位移植肿瘤(S-180)生长的抑制作用.结果表明,rhTnC在大肠杆菌中呈可溶性表达.分离纯化后的rhTnC在体外对人脐静脉内皮细胞生长呈剂量依赖性抑制(IC50为7.5μg/ml);对小鼠异位移植肿瘤的生长也有明显的抑制作用,在20mg/(kg·d)剂量下对S-180的抑制率为64.4%.以上结果说明,rhTnC可抑制血管内皮细胞生长,并具有抗肿瘤作用.     

脯氨酸测定方法的改进

25mg·mL-1的酸性茚三酮溶液至少可以保存35 d,它与同体积脯氨酸充分反应的最大浓度为156μg·mL-1,当样品提取液的浓度大于100μg·mL-1时,需适当稀释.酸性茚三酮与脯氨酸充分显色的时间至少30 min沸水浴.     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

Chemokines and cytokines: axis and allies in asthma and allergy

Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.     

Oxidation and nitration of ribonuclease and lysozyme by peroxynitrite and myeloperoxidase

In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.