蛭弧菌J26发酵生产维生素C前体产物的鉴定

采用有机溶剂沉淀方法去除J26发酵液中杂蛋白,通过离子交换、活性炭吸附去除发酵液中杂质,最后蒸发浓缩获得无色透明结晶。通过对所获晶体的红外光谱分析、熔点测定、纸层析鉴定,证明所获晶体确为维生素C前体2－酮基－L－古龙酸（2－KGA）。     

动脉内灌药,内支架安置双介入治疗十二指肠恶性梗阻

通过动脉内灌药,内支架安置双介入治疗提高对十二指肠恶性梗阻姑息性治疗的疗效。十二指肠恶性梗阻病例１４例,男５例,女９例,年龄２０－６９岁,经口安置自膨式十二指肠金属支架共１５枚,其中１２例在支架安置后定期行肿瘤供血动脉插管介入化疗,所有病例梗阻症状解除,２例未行动脉灌药治疗者分别于２个月及４个月死亡,１２例双介入者生存期明显延长,最短６月,最长已达一年,结论：双介入治疗能够姑息治疗疗效延长晚期瘤患     

Antibiotics and enzymes produced by the biocontrol agent Streptomyces violaceusniger YCED-9

Streptomyces violaceusniger strain YCED-9 is an antifungal biocontrol agent antagonistic to many different classes of plant pathogenic fungi. We discovered that strain YCED-9 produces three antimicrobial compounds with antifungal activity. These compounds were purified and identified, and included: AFA (Anti-Fusarium Activity), a fungicidal complex of polyene-like compounds similar to guanidylfungin A and active against most fungi except oomycetes; nigericin, a fungistatic polyether; and geldanamycin, a benzoquinoid polyketide highly inhibitory of mycelial growth of Pythium and Phytophthora spp. Antimicrobial assays were developed to estimate the production of each antibiotic independently. Medium composition had differential effects on the production of each metabolite. The hydrolytic enzymes chitinase and β-1,3-glucanase are also produced under induction by colloidal chitin and laminarin, respectively. Fungal cell walls induced the production of both enzymes. A potential for biological control of diseases caused by P. infestans was also suggested by strain YCED-9’s strong in vitro antagonism towards pathogenic isolates of this fungus. Received 27 October 1997/ Accepted in revised form 8 June 1998     

The use of norbornene derivatives in the synthesis of conformationally constrained peptides and pseudo-peptides

Summary The desymmetrisation ofendo-norborn-5-ene-2,3-dicarboxylic anhydride by proline esters has been used to prepare conformationally constrained pseudo-peptides with two peptide chains parallel to one another. A Curtius rearrangement on the desymmetrication adduct produced the corresponding isocyanate which was used to prepare both a peptide incorporating anendo-2-amino-3-carboxy-norborn-5-ene unit, and a pseudo-peptide with two peptide chains parallel to one another but offset by the presence of a urea unit. The conformational analysis of the resulting peptides was carried out, and the norbornene unit was found to induce the formation of β-turns and parallel β-sheets.     

Structures of the N-linked carbohydrate of ascorbic acid oxidase from zucchini

N-glycan moiety of ascorbic acid oxidase from zucchini (Cucurbita pepo) has been described to be a core-pentasaccharide with a xylose [D'Andrea et al. (1988) Glycoconjugate J 5:151-7]. Ascorbic acid oxidase is sometimes used to characterize antibodies directed against carbohydrate determinants on plant glycoproteins. To prevent misinterpretations of immunological data, the structure of the N-glycan of ascorbic acid oxidase has been reinvestigated. The oligosaccharides were released by almond N-glycosidase and analysed as their pyridylamino derivatives by 2D-HPLC and exoglycosidase digestions. The main structure resembled the typical complex plant N-glycan consisting of a core-pentasaccharide decorated with xylose and 3-linked fucose. The other abundant species lacked the fucose residue. Small amounts of these glycans carried a GlcNAc residue on the 6-arm. Therefore, ascorbic acid oxidase will not only react with antibodies directed against the xylosylated region but also with those binding to N-glycans with 3-linked fucose.     

结直肠癌组织miR-137-3p、miR-410-3p表达水平与上皮间充质转化和预后的关系分析

摘要 目的：探讨结直肠癌（CRC）组织微小RNA-137-3p（miR-137-3p）、微小RNA-410-3p（miR-410-3p）的表达与上皮间充质转化（EMT）和预后的关系。方法：选取2017年2月至2019年2月本院收治的115例接受CRC根治术治疗的患者，采用实时荧光定量聚合酶链式反应（qRT-PCR）检测癌组织及癌旁组织中miR-137-3p、miR-410-3p表达、EMT标志物E-钙粘蛋白（E-cadherin）、波形蛋白（Vimentin）的mRNA表达并进行相关性分析，分析癌组织中miR-137-3p、miR-410-3p表达与CRC临床病理特征的关系。术后随访3年，采用Kaplan-Meier法分析miR-137-3p、miR-410-3p高表达和低表达患者的预后情况。结果：癌组织中miR-137-3p表达及E-cadherin mRNA表达水平低于癌旁组织，miR-410-3p表达及Vimentin mRNA表达水平高于癌旁组织（P＜0.05）。癌组织中miR-137-3p表达与E-cadherin mRNA表达水平、miR-410-3p表达与Vimentin mRNA表达水平分别呈正相关（P＜0.05），癌组织中miR-137-3p表达与Vimentin mRNA表达水平、miR-410-3p表达与E-cadherin mRNA表达水平分别呈负相关（P＜0.05）。miR-137-3p、miR-410-3p表达与TNM分期、肿瘤分化程度、淋巴结转移有关（P＜0.05）。Kaplan-Meier生存曲线分析显示，miR-137-3p低表达、miR-410-3p高表达患者3年累积生存率下降（P＜0.05）。结论：CRC组织中miR-137-3p表达下调、miR-410-3p表达上调，miR-137-3p、miR-410-3p表达水平与EMT密切相关，且miR-137-3p高表达、miR-410-3p低表达患者的预后更好。