Antimicrobial activities of novel bipyridine compounds produced by a new strain of Saccharothrix isolated from Saharan soil

The actinobacterium strain ABH26 closely related to Saccharothrix xinjiangensis, isolated from an Algerian Saharan soil sample, exhibited highly antagonist activity against Gram-positive bacteria, yeasts and filamentous fungi. Its ability to produce antimicrobial compounds was investigated using several solid culture media. The highest antimicrobial activity was obtained on Bennett medium. The antibiotics secreted by strain ABH26 on Bennett medium were extracted by methanol and purified by reverse-phase HPLC using a C18 column. The chemical structures of the compounds were determined after spectroscopic (¹H NMR, ¹³C NMR, ¹H-¹H COSY and ¹H-¹³C HMBC spectra), and spectrometric (mass spectrum) analyses. Two new cyanogriside antibiotics named cyanogriside I (1) and cyanogriside J (2), were characterized along with three known caerulomycins, caerulomycin A (3), caerulomycin F (4) and caerulomycinonitrile (5). This is the first report of cyanogrisides and caerulomycins production by a member of the Saccharothrix genus. The minimum inhibitory concentrations (MIC) of these antibiotics were determined against pathogenic microorganisms.     

以肺动脉高压为首发表现的先天性中枢性低通气综合征临床特征和基因分析

目的探讨先天性中枢性低通气综合征(CCHS)的临床和基因变异特征。方法分析1例首发表现为不明原因肺动脉高压的CCHS患儿的临床资料,并总结国内外文献中CCHS病例的临床特点、致病机制和基因变异情况。结果11月龄女婴,主要表现为浮肿、尿少、低血压、嗜睡、发绀、抽搐及颅内压增高。B型脑利钠肽、丙氨酸氨基转移酶升高,凝血酶原时间延长。颅脑磁共振示右侧额叶出血;超声心动图示中重度肺动脉高压。靶向捕获二代测序未发现可能的致病基因。采用Sanger法验证示患儿PHOX 2 B基因第3外显子存在多聚丙氨酸重复扩展变异,基因型为20/25。患儿入院后采用无创通气,睡眠时呼吸浅慢、微弱,伴血氧下降;血气分析提示二氧化碳潴留。随后改用夜间无创通气、降肺压药物治疗。复查肺动脉压力明显下降,生命体征稳定。随访至24月龄,夜间只需较低压力水平的无创通气,生长发育无异常。结论对于不明原因的肺动脉高压伴撤机困难患儿,需警惕CCHS。疑诊者应尽早针对CCHS相关基因进行靶向捕获二代测序及PHOX 2 B基因Sanger法验证。早期给予无创通气有望改善预后。     

化浊清解愈溃煎对溃疡性结肠炎大鼠p38MAPK、TNF-α、IL-4的影响

目的观察化浊清解愈溃煎对溃疡性结肠炎(UC)大鼠血清及结肠组织p38MAPK、肿瘤坏死因子-α(TNF-α)、白细胞介素-4(IL-4)含量的影响。方法清洁级Wistar雄性大鼠50只按随机数字表法分为两组,空白组8只,其余大鼠均为造模组。采用TNBS/乙醇联合造模法构建UC大鼠模型。造模成功后按照随机数字表法将模型大鼠分为模型组、西药组(予美沙拉嗪肠溶片混悬液0.42 g/kg)及中药高、中、低剂量组。中药高、中、低剂量组予化浊清解愈溃煎中药混悬液,剂量分别为22、11、5.5 g/(kg·d),每日灌胃1次,疗程14 d。采用免疫组化法检测各组大鼠结肠组织内p38MAPK的蛋白表达量。ELISA法检测各组大鼠血清内TNF-α、IL-4含量。结果与空白组比较,模型组一般情况较差,血清中TNF-α含量显著升高(P<0.05),IL-4含量则明显降低(P<0.05),结肠组织中p38MAPK水平明显升高(P<0.05)。与模型组比较,西药组、中药各剂量组大鼠一般生存状况改善明显,血清中TNF-α含量下降,IL-4含量明显升高,尤以中药高剂量组和西药组疗效显著(P<0.05)。结论化浊清解愈溃煎高、中剂量可改善UC大鼠一般生存状况,并通过调节血清中IL-4含量,下调TNF-α表达水平和结肠组织中p38MAPK蛋白表达水平而达到保护结肠黏膜和治疗UC的作用。     

Prenatal diagnosis of mosaicism for a distal 5p deletion in a single colony at amniocentesis in a pregnancy with a favorable outcome and a review of mosaic distal 5p deletion

ObjectiveWe present prenatal diagnosis of mosaicism for a distal 5p deletion in a single colony at amniocentesis with a favorable outcome, and we review the literature of mosaic distal 5p deletion.Case ReportA 35-year-old primigravid woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age. Amniocentesis revealed the result of 46,XY,del(5)(p13)[1]/46,XY[19]. Among 20 colonies of cultured amniocytes, all four cells in one colony had a karyotype of 46,XY,del(5)(p13) with a distal deletion of 5p13→pter, while the rest 19 colonies had a karyotype of 46,XY. Repeat amniocentesis was performed at 21 weeks of gestation. Conventional cytogenetic analysis revealed a karyotype of 46,XY in all 20 colonies. Simultaneous array comparative genomic hybridization (aCGH) using the DNA extracted from the uncultured amniocytes revealed no genomic imbalance. Prenatal ultrasound findings were unremarkable. At 38 weeks of gestation, a 3621-g male baby was delivered with no phenotypic abnormality. The cord blood had a karyotype of 46,XY. Postnatal urinary cells analysis by interphase fluorescence in situ hybridization (FISH) using a 5p terminal FISH probe detected no abnormal cell in the urine.ConclusionMosaicism for a distal 5p deletion in a single colony at amniocentesis can be associated with a favorable outcome.     

中国优秀马拉松运动员ACE基因I/D多态性频率分布特征

通过分析中国马拉松运动员ACE基因I/D多态频率分布特征,探讨其作为杰出耐力基因标记的可行性。选择我国马拉松健将、国际健将级运动员26名作为马拉松运动员组,汉族学生216名作为对照组。对两组受试者进行ACE基因I/D多态性测定。结果显示:我国马拉松运动员组的等位基因频率和基因型频率与对照组比较无显著差异,其中15名国际健将中无一DD型纯合子,提示我国优秀马拉松运动员的纯合子DD型频率低下是其ACE基因多态频率分布的主要特征。     

纤维素分解菌BSX5的分离、鉴定及产酶条件

利用透明圈法从袋装降解的笋干中分离到一株分解纤维素的细菌菌株. 该菌株呈长杆状、革兰氏染色为阳性、产芽孢,命名为BSX5.其生理生化特征和16S rDNA序列同源性分析,发现该菌株与Bacillus subtilis的同源性为99%,系统发育树分析与Bacillus subtilis遗传关系最近,确定该菌株为Bacillus subtilis. 采用以3,5-二硝基水杨酸（DNS）为显色剂、羧甲基纤维素钠（CMC-Na）为底物,测定不同培养条件下BSX5菌株的酶活力,结果最适产酶时间为8-12 h,最适产酶温度为50 ℃,最适产酶pH值为5.5～6.5.     

人间充质干细胞免疫原性研究

目的探讨人间充质干细胞(hMSCs)特性及免疫原性,为进一步研究hMSCs移植特性提供实验依据。方法免疫组化方法鉴定hMSCs表面HLA-ABC、HLA-DR、CD80、CD86分子;流式细胞术检测其含量;RT-PCR检测HLA-ABC、HLA-DRmRNA基因片断;外周血淋巴细胞杀伤试验及 CCK-8比色法规察淋巴细胞增殖反应;将表达绿色荧光蛋白(GFP)的DNA复合物导入hMSCs进行大鼠脑内移植,观察hMSCs在脑内的存活情况。结果 hMSCs表面少量表达HLA-ABC分子,不表达 HLA-DR、CD80、CD86分子;有少量HLA-ABC mRNA基因片断存在,未发现HLA-DR mRNA基因片断;外周血淋巴细胞杀伤试验没有发现淋巴细胞增殖反应;大鼠脑内移植hMSCs一个月后仍可见有细胞存活。结论 hMSCs具有较弱的免疫原性。     

PDE5基因siRNA对人阴茎海绵体平滑肌细胞cGMP的影响

目的:观察PDE5基因小干扰RNA(siRNA)对人阴茎海绵体平滑肌细胞环磷酸鸟苷(cGMP)的影响,为阴茎勃起功能障碍(ED)的基因治疗提供实验依据。方法:使用美国Amb ion公司提供的设计软件设计并合成人PDE5基因的siRNA序列,合成3对PDE5 siRNA和1对阴性对照siRNA,转染人阴茎海绵体平滑肌细胞,同时设定空白转染组为对照组。以酶联免疫法分别检测转染后不同时间(24、48、72、96 h)点海绵体平滑肌细胞内cGMP浓度变化,观察PDE5 siRNA对海绵体平滑肌细胞内cGMP的影响。结果:siRNA1、siRNA2和siRNA3转染后人阴茎海绵体平滑肌细胞cGMP水平显著高于阴性对照siRNA组和空白对照组(P<0.05),在转染后72 h最为显著,siRNA1、siRNA2、siRNA3、阴性对照siRNA和空白对照组cGMP测定值分别为:5.89±0.19、3.52±0.16、2.88±0.08、0.72±0.12、0.60±0.16 pmol/m l,siRNA1组明显高于siRNA2、siRNA3组(P<0.05)。结论:体外化学合成的PDE5 siRNA能有效地增加海绵体平滑肌细胞内cGMP的水平,不同序列siRNA增加cGMP水平的能力不同,为ED的基因治疗提供了新思路。