Antioxidant and UV-radiation absorption activity of aaptamine derivatives – potential application for natural organic sunscreens

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Direct antioxidant activities of C1–C3 were firstly evaluated via their intrinsic thermochemical properties and the radical scavenging activity of the potential antioxidants with the HOO˙/HO˙ radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO˙ scavenging in water occurs via HAT mechanism with C1 (k_app, 7.13 × 10⁶ M⁻¹ s⁻¹) while RAF is more dominant with C2 (k_app, 1.40 × 10⁵ M⁻¹ s⁻¹) and C3 (k_app, 2.90 × 10⁵ M⁻¹ s⁻¹). Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. Indirect antioxidant properties based on Cu(i) and Cu(ii) ions chelating activity were also investigated in aqueous phase. All three studied compounds show spontaneous and favorable Cu(i) ion chelating activity with ΔG⁰ being −15.4, −13.7, and −15.7 kcal mol⁻¹, whereas ΔG⁰ for Cu(ii) chelation are −10.4, −10.8, and −2.2 kcal mol⁻¹ for C1, C2 and C3, respectively. In addition, all compounds show UVA and UVB absorption; in which the excitations are determined mostly as π–π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as a sunscreen and antioxidant ingredient.

Antioxidant and UV absorption activities of three aaptamine derivatives were theoretically studied by density functional theory (DFT) and time-dependent density functional theory (TD-DFT).     

Assessment and treatment of floodwater in the Vietnamese Mekong Delta using a simple filter system based on silver nanoparticles coated onto activated carbon derived from rice husk

The floods in the Vietnamese Mekong Delta have long caused a shortage of clean water supply, which has a significant impact on the indigenous people in the region. We have conducted a preliminary survey of the water quality of the Hau Giang River (one of the two main branches of the Mekong River) before, during, and after the flood season. The obtained results demonstrated that the water in the Hau Giang River was highly turbid and contaminated with a large number of harmful microorganisms. Thus, in this study, a simple filter system based on silver nanoparticles coated onto activated carbon derived from rice husk (AgNPs@AC) has been proposed for treating floodwater from the Hau Giang River. The optimal conditions for AgNPs@AC preparation were established. The prepared AgNPs@AC was then characterized using various surface analyses such as SEM, TEM, XRD, BET, FTIR, and DLS. The initial floodwater source would be pre-treated with polyaluminum chloride using the coagulation–sedimentation method to remove the suspended solids before being discharged into the filtration column containing AgNPs@AC. The results showed that the filter system based on AgNPs@AC performed well in removing turbidity, dissolved solids, suspended solids, color, and bacteria from the floodwater. In addition, it was determined that the filter column with a 30 mm thick AgNPs@AC layer could continuously process 1300 m³ of the floodwater and had a service life of more than two months. The findings of this study not only added to our understanding of the floodwater treatment capacity of activated carbon coated nanoparticles, but they also provided valuable information for water treatment plants along the Hau Giang River, aquatic ecosystem researchers, and public health researchers.

In this study, a simple filter system based on silver nanoparticles coated onto activated carbon derived from rice husk (AgNPs@AC) has been proposed for treating floodwater from the Hau Giang River.     

H. pylori Infection and Colorectal Cancers by Anatomical Locations

Background: H. pylori infection may play a role in the development of colorectal cancers (CRC). We aimed to examine the association between H. pylori infection and the risk of CRC by anatomical locations. Methods: We conducted a case-control study on 91 incidence cases of CRC and 224 hospital controls. CRC was determined by histopathological examinations. H. pylori IgG antibody in serum was tested. We collected data on the diet, nutrition, and lifestyle by the validated semi-quantitative food frequency and demographic lifestyle questionnaire. The odds ratio and 95% confidence interval (OR (95%CI) were estimated for CRC and its subgroups. Results: Overall 54.95% of CRC cases and 42.41% of the controls were H. pylori-seropositive, OR (95%CI): 1.56 (0.88, 2.74), p for trend=0.115. Positive dose-response association in quartiles, highest vs lowest, was observed for total CRC, OR (95%CI): 2.14 (1.00, 4.58), p for trend=0.049, for proximal colon, OR (95%CI): 1.52 (0.37, 6.25), p for trend=0.571), and for distal colon and rectum cancers combined, OR (95%CI): 2.38 (1.03, 5.50), p for trend=0.039. Conclusions: There is a positive association between H. pylori and colorectal cancers, especially distal colon and rectum cancers combined, but additional research is needed to determine the underlying mechanism of chronic H. pylori infection-induced CRC in humans.     

Right coronary artery fistula to left ventricle complicated with huge coronary artery aneurysm

Congenital coronary artery fistula (CAF) with huge coronary artery aneurysm is a very rare condition. In this paper, we describe a 26-year-old asymptomatic male patient with right coronary artery (RCA) to the left ventricle fistula with a huge coronary artery aneurysm which was diagnosed by multidetector computed tomography and coronary angiography. The patient received surgical treatment for coronary artery after diagnosis. Both RCA and a giant aneurysm were excised; surgical closure of CAF and coronary artery bypass grafting were performed on this patient. Two months after surgery, the enlarged left ventricle returned to normal as evaluated by echocardiography.     

纤溶酶-α2抗纤溶酶复合物检测方法的建立和初步临床应用

目的　建立纤溶酶 α2 抗纤溶酶复合物 (PAP)的检测方法。方法　从血浆中纯化PAP作为免疫原制备单克隆抗体 (单抗 ) ,建立双抗体夹心法酶联免疫吸附试验 (ELISA) ,并对该法进行评价。结果　获取了特异针对PAP新抗原的单抗LW 3C10 ,和针对PAP及纤溶酶原 (Plg)的单抗LW 2B9。对PAP的亲和常数分别为 4 6 9× 10 10 mol/L、5 6 2× 10 9mol/L。以它们建立的夹心ELISA检测PAP在 0～ 15 0 μg/L范围内线性良好 ,批内、批间CV分别为 4 0 %～ 5 2 %、11 2 %～ 13 6 % ,回收率为 85%～ 10 5 % ,加入α2 抗纤溶酶 (α2 AP)及纤溶酶 α2 巨球蛋白复合物 (P α2 M)不干扰测定 ,与美国ADI公司PAP试剂盒相关良好 (r=0 96 2 9)。急性髓细胞白血病组、急性心肌梗死组、肝病组、健康老年人组的血浆PAP水平显著高于正常对照组 (P <0 0 0 1)。结论　该法可用于评估纤溶系统激活。     

遗传性凝血因子Ⅺ缺陷症一例家系基因缺陷研究

目的 分析1例遗传性凝血因子Ⅺ(FⅪ)缺陷症家系表型和分子遗传学特征,对凝血因子基因(F11)进行基因缺陷研究.方法 通过检测先证者及家系成员的活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、FⅪ促凝活性(FⅪ:C)和FⅪ抗原(FⅪ:Ag)等进行临床表型诊断,应用PCR对先证者F11基因15个外显子及其侧翼序列进行扩增,对PCR产物进行直接测序.对先证者及其父母、100名健康对照者DNA相应区域进行PCR扩增,内切酶BssSI酶切,以排除基因多态性并确认突变位点.应用分析软件SignalP对信号肽切割点及位置进行预测.结果 先证者APTT为69.5 s,PT为12.3 s,FⅪ:C为2.6%,FⅪ:AS为2.5%,交叉反应物质(CRM)为阴性;健康对照组APTT为35 s,PT为13 s,FⅪ:C为100%,FⅪ:Ag为100%.测序发现,先证者F11基因外显子区共有4处与GenBank AY191837序列不同的位点,其中外显子2的G3733C杂合变异导致编码信号肽的氨基酸G-1R替换,该突变同时导入1个新的BssSI酶切位点.100名健康对照者的BssSI酶切结果排除了该变异为F11基因多态性.外显子8的C16642T杂合突变导致1个终止密码(Q263Term)产生.结论 F11基因G-1R和Q263Term双重杂合突变是导致先证者遗传性凝血因子Ⅺ缺陷症的分子发病机制.     

凝固酶阴性葡萄球菌的鉴定及分类

目的 探讨凝固酶阴性葡萄球菌简化生化反应检索表的鉴定分类技术.方法 采用凝固酶活性,溶血作用,硝酸盐还原以及有氧条件下分解,下记10种糖类(木糖、蔗糖、阿拉伯糖、海藻糖、木糖醇、果糖、麦芽糖、乳糖、核糖、甘露醇)等实验进行鉴定分类.结果 按简化生化反应检索表的程序对446株凝固酶阴性葡萄球菌鉴定分类,获得表皮葡萄球菌322株(72.2%),孔氏葡萄球菌36株(8.1%),木糖葡萄球菌26株(5.8%),华氏葡萄球菌24株(5.4%),腐生葡萄球菌20株(4.5%),头状葡萄球菌4株(0.9%),人型葡萄球菌及溶血葡萄球菌各2株,另有10株不能定种.结论 凝固酶阴性葡萄球菌按凝固酶实验和甘露醇实验的结果可初步分为表皮葡萄球菌和其他凝固酶阴性葡萄球菌两大类,在观察有氧条件下各种糖类分解实验过程中,注意到凝固酶阴性葡萄球菌对多种糖类能在培养48 h内分解产酸,但对木糖和麦芽糖的分解,有些菌种则需3～7 d,呈迟缓分解.建议糖类分解实验以连续观察7 d再确定阴性为好.     

Triterpenoids from the leaves of Diospyros kaki (persimmon) and their inhibitory effects on protein tyrosine phosphatase 1B

Phytochemical study on a methanol-soluble extract of the leaves of persimmon (Diospyros kaki) resulted in the isolation of two new ursane-type triterpenoids, 3alpha,19alpha-dihydroxyurs-12,20(30)-dien-24,28-dioic acid (1) and 3alpha,19alpha-dihydroxyurs-12-en-24,28-dioic acid (2), together with 12 known ursane- and oleanane-type triterpenoids (3-14). Triterpenoids with a 3beta-hydroxy group were found to inhibit protein tyrosine phosphatase 1B (PTP1B) activity, with IC50 values ranging from 3.1+/-0.2 to 18.8+/-1.3 microM, whereas those with a 3alpha-hydroxy moiety were not active.     

兔膀胱移行上皮细胞构建组织工程尿道的初步研究

目的 探索以膀胱移行上皮细胞为种子细胞构建组织工程尿道的可行性。方法 取兔膀胱移行上皮细胞，体外培养传代后作为种子细胞与自制胶原膜体外联合培养并行裸鼠体内移植，通过对复合物扫描电镜、HE染色及角蛋白免疫组化检测，了解细胞在材料上的生长情况。结果 2h后移行上皮细胞在胶原膜上贴附生长，复合物移植体内20d后，移行上皮细胞分化成层，层厚1～5层。结论 该方法获取的膀胱移行上皮细胞是构建组织工程尿道的良好种子细胞，与胶原膜构建的复合物在体内形成了尿道类似物，有望成为替代尿道的组织工程材料。     

脑肿瘤患者手术前后T细胞亚群及NK细胞活性的变化

目的 探讨脑肿瘤患者手术前后细胞免疫功能的变化及其临床意义。方法 采用单克隆抗体酶标法对22例脑肿瘤和12例脑内血肿患者手术前后不同时期的T细胞亚群及NK细胞活性进行动态监测。结果 脑肿瘤CD3^ 、CD4^ ,CD10^16 56和CD4^ /CD8^ 比值较对照组均有不同程度降低。而胶质瘤组较其余两组明显下降。34例患者术后4期CD3^ ,CD4^ ,CD16 56^ 比值均发生变化。胶质瘤组在术后1至2周明显低于其余两组。术后3至4周才逐渐恢复至正常水平。结论 脑肿瘤患者细胞免疫功能被抑制。且恶性胶质瘤较良性肿瘤更为明显，手术应激能导致T细胞亚群及NK细胞活性变化。脑肿瘤切除术后细胞免疫功能呈现暂时抑制至逐渐恢复的过程。