呼气分析技术及其在临床诊断中的应用研究进展

呼气分析技术是一种通过检测呼出气体中特征性成分的变化,从而为临床诊断提供辅助信息的检查方法.与传统方法相比,该技术具有无创伤、简捷、易实现等优点,在疾病的早期诊断与筛查过程中具有巨大潜力,但在临床医学实际应用中尚存在一些问题亟待解决.阐述呼气分析技术中呼气采集、检测方法以及在疾病诊断中的应用等三方面内容,对国内外呼吸诊...     

阿德福韦酯联合双环醇片治疗HBeAg(+)慢性乙型肝炎疗效分析

目的 研究阿德福韦酯联合双环醇片治疗慢性乙型肝炎的疗效.方法 选择91例轻、中度慢性乙型肝炎患者随机分2组接受试验.试验组,46例,每日口服阿德福韦酯10 mg,同时每日服用双环醇片150 mg;对照组,45例,仅给予每日口服阿德福韦酯10 mg.2组均连续用药48周.观察治疗前后血清氨基转移酶水平及病毒学标志方面的改变.结果 2组血清氨基转移酶均得到明显下降,试验组更为显著(P<0.05).试验组HBV DNA阴转率(47.8%)显著高于对照组(31.1%),P<0.05,试验组HBeAg阴转率(32.6%)及HBeAg血清转换率(24.4%)虽高于对照组(19.6%、15.6%),但差异无统计学意义.2组均未发生明显的不良反应.结论 阿德福韦酯与双环醇片联合应用治疗慢性乙型肝炎在肝功能及病毒学方面取得较好疗效.     

On the Preparation and Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene/Acrylic Acid Copolymer and of New Phosphazene Compounds

Summary: Samples of HDPE and PA6 have been melt‐processed in the presence of two new phosphazene compounds, CP‐2EPOX and CP‐2OXA together with an ethylene/acrylic acid copolymer. The blends have been prepared in an industrial twin‐screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE‐rich blend in the presence of CP‐2EPOX. This result can be attributed both to a chain extension reaction on EAA and PA6 phases and on compatibilization effect due to the possible formation of EAA‐g‐PA6 copolymers. This latter occurrence is suggested by an improved adhesion between the phases and by an increased turbidity observed in the Molau tests. Between the two compatibilizers, the CP‐2EPOX displays the overall best results, especially for the PE‐based blends.

SEM micrograph of the PA6‐based binary blend.     

环氧-二十碳三烯酸：细胞内信号转导通路

花生四烯酸 (ａｒａｃｈｉｏｎｄｉｃａｃｉｄ ,ＡＡ)细胞色素Ｐ4 5 0单氧化酶代谢产物是环氧 -二十碳三烯酸 (ｅｐｏｘｙｅ ｉｃｏｓａｔｒｉｅｎｏｉｃａｃｉｄ ,ＥＥＴｓ) ,可分为 :5 ,6 -ＥＥＴ ;8,9-ＥＥＴ ;11,12 -ＥＥＴ和 14,15 -ＥＥＴ[1] 。ＥＥＴｓ作为内皮衍生性超极化因子 (ｅｎｄｏｔｈｅｌｉａｌｄｅｒｉｖｅｄｈｙｐｅｒｐｏｒｌａｒｉｎｇｆａｃｔｏｒ ,ＥＤＨＦ) ,调节多种血管张力 ;抑制血小板的聚集 ;促进有丝分裂等。近来 ,有关ＥＥＴｓ的作用机制尤其在信号转导方面的作用引起了重视。近来的研究表明 ,ＥＥＴｓ通过影…     

Identification of N-(deoxyguanosin-8-yl)-4-azobiphenyl by (32)P-postlabeling analyses of DNA in human uroepithelial cells exposed to proximate metabolites of the environmental carcinogen 4-aminobiphenyl

DNA adducts formed in human uroepithelial cells (HUC) following exposure to N-hydroxy-4-aminobiphenyl (N-OH-ABP), the proximate metabolite of the human bladder carcinogen 4-aminobiphenyl (ABP), were analyzed by the (32)P-postlabeling method. Two adducts detected by (32)P-postlabeling were previously identified as the 3',5'-bisphospho derivatives of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP) and N-(deoxyadenosin-8-yl)-4-aminobiphenyl (dA-C8-ABP) (Frederickson S et al. [1992] Carcinogenesis 13: 955-961; Hatcher and Swaminathan [1995b] Carcinogenesis 16: 295-301). In contrast to the dG-C8-ABP adduct, which was 3'-dephosphorylated by nuclease P1, dA-C8-ABP was resistant to nuclease P1, thus providing an enrichment step before postlabeling. Autoradiography of the two-dimensional thin-layer chromatogram of the postlabeled products obtained following nuclease P1 digestion revealed several minor adducts, one of which has been identified in the present study. Postlabeling analyses following nuclease P1 digestion of the products obtained from the reaction of N-acetoxy-4-aminobiphenyl with deoxyguanosine-3'-monophosphate (dGp) demonstrated the presence of this minor adduct. The 3'-monophosphate derivative of the adduct was subsequently chromatographically purified and subjected to spectroscopic analyses. Based on proton NMR and mass spectroscopic analyses of the synthetic product, the chemical structure of the adduct has been identified as N-(deoxyguanosin-N(2)-yl)-4-azobiphenyl (dG-N==N-ABP). (32)P-Postlabeling analysis of the nuclease P1-enriched DNA hydrolysate of HUCs treated with N-OH-ABP or N-hydroxy-4-acetylaminobiphenyl (N-OH-AABP) showed the presence of the dG-N==N-ABP adduct. It was also detected in calf thymus DNA incubated with HUC cytosol and N-OH-ABP in the presence of acetyl-CoA, or incubated with HUC microsomes and N-OH-AABP. These results demonstrate that in the target cells for ABP carcinogenesis in vivo, N-OH-ABP and N-OH-AABP are bioactivated by acyltransferases to reactive arylnitrenium ions that covalently interact at the N2 position of deoxyguanosine in DNA.     

磁性纳米靶向Apo—A—Ⅰ基因治疗对大鼠动脉粥样硬化斑块发展的作用

目的观察载脂蛋白A族Ⅰ型（Apo-A—Ⅰ）基因对动脉粥样硬化（AS）斑块发展的作用。方法将超微超顺磁性氧化铁（USPIO）作为磁性纳米载药系统输送治疗基因,用逆相蒸发法制备带正电荷的磁性脂质体,再将DNA与该脂质体按照1：7的电荷比形成复合物：将已形成AS斑块的12只大鼠分为实验组和对照组。实验组6只大鼠经尾静脉注入磁性纳米脂质体／DNA复合物．对照组6只大鼠经尾静脉注入不含基因的磁性纳米脂质体复合物．每只动物给药剂量为0．32ml．给药后立刻在所有动物左侧肾脏附近（体外）绑缚铷铁硼稀土磁铁（场强500mT）进行磁诱导。约4h后将磁铁取下。继续喂养6周后抽血测定血清总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）,并将动物处死,取腹主动脉进行油红O染色。结果基因治疗6周后．实验组80层切片中发现斑块10层．脂质条纹面积和纤维斑块面积的百分比分别为9．21％和1．18％：对照组83层切片中发现斑块35层．脂质条纹面积和纤维斑块面积的百分比分别为32．25％和1．66％。实验组与对照组进行斑块率的比较,P〈0．01,实验组HDL水平明显升高,实验组肝组织Apo-A—ⅠmRNA水平明显高于对照组。结论DNA与逆相蒸发法制备的磁性脂质体形成的磁性纳米脂质体／DNA复合物在外加磁场导入下可以使ADo—A—Ⅰ基因定向到达肝脏,显著升高血浆HDL水平,降低LDL、TC、TG水平,抑制AS斑块的发展。     

An innovative quaternary ammonium methacrylate polymer can provide improved antimicrobial properties for a dental adhesive system

A quaternary ammonium methacrylate polymer (QAMP) with antimicrobial potential was synthesized. The resulting product (QAMP) was characterized by FTIR spectroscopy, NMR spectroscopy, visible spectrophotometry, XRPD and TGA. The in vitro susceptibility tests against Streptococcus mutans of QAMP were investigated prior and after incorporation into a commercial adhesive system (Clearfil? SE Bond). The release of quaternary ammonium compounds from the experimental adhesive system (Clearfil? SE Bond?+?5% QAMP) was performed during 1, 7, 14, 21 and 30 days. Spectroscopic data confirmed that QAMP was successfully obtained. Thermogravimetric analysis indicated that QAMP was heat stable. Prior incorporation into the adhesive system, QAMP revealed an inhibition halo of 18.33?±?0.6?mm. By agar disk diffusion test, Clearfil? SE Bond containing 5% QAMP presented an inhibition halo (16.67?±?1.5?mm) similar to Clearfil? Protect Bond (positive control, 17.00?±?1.7, p?=?0.815) and significantly higher than Clearfil? SE Bond (negative control, 11.00?±?1.0, p?=?0.006). The minimum inhibitory/bactericidal concentrations for Clearfil? SE Bond containing 5% QAMP were 20?μL?mL^?1. The release of quaternary ammonium compounds from the experimental adhesive containing QAMP was very low (5.1%) when compared to Clearfil? Protect Bond that released 47.2% of its quaternary ammonium monomer (MDPB) after 30 days. The QAMP can offer enhanced antimicrobial properties for self-etching adhesive systems.     

Antimicrobial and Antiplasmodial Activities of a Quaternary Compound from Ritchiea Capparoides Var. Longipedicellata

The leaves of Ritchiea capparoides var. longipedicellata (Capparidaceae) is used in ethnomedicine in South-Western Nigeria to treat infectious and parasitic diseases. This study was aimed at identifying the compound(s) that are responsible for the antimicrobial and antiplasmodial activities of the leaves and also to contribute to the chemistry of the plant species. A 70 % aqueous ethanolic extract of the leaves of R. longipedicellata was subjected to repeated liquid chromatographic methods on silica gel, Lobar RP-18 column and Sephadex LH-20 to isolate a Draggendorf positive compound. The compound was identified by ¹H and ¹³C NMR, ultra-violet spectroscopy and polarimetry. The antimicrobial activity of the compound was evaluated using the microbroth dilution method while the antiplasmodial activity was carried out according to Trager and Jenson (1976). The minimum inhibitory concentration (MIC) was expressed in mg/ml. The isolated compound, leavoisomer of stachydrine, inhibited the growth of Escherichia coli NCTC 8196 and Staphylococcus aureus NCTC 6571 at the MIC of 5 mg/ml. In the anti-malaria assay, the compound had inhibitory activity with the concentration required to cause 100% lethality being 0.667 mg/ml.Conclusion: The antibacterial and antiparasitic effects of quaternary ammonium compounds are well documented. However, this study is the first report of the presence and biological activities of this compound in this plant species which may justify the ethnomedicinal uses of the leaves.     

The effects of topical nasal steroids on rat respiratory mucosa in vivo, with special reference to benzalkonium chloride

Fifty rats were treated with topical nasal steroids with and without the preservative benzalkonium chloride in their right nostril twice daily for 21 days, while the left nostrils were exposed to 0.9% NaCl. By cutting the noses serially in frontal sections, the structure of the mucosal lining of all parts of the nose could be investigated. Areas with squamous cell metaplasia were observed in all nostrils exposed to topical steroids containing benzalkonium chloride. Such alterations were not observed in any nasal cavities exposed to the topical nasal steroid without the preservative or to 0.9% NaCl. In conclusion, benzalkonium chloride appears to be potentially toxic to the mucosa in vivo.