Analysis of the sugar-binding specificity of mannose-binding-type Jacalin-related lectins by frontal affinity chromatography--an approach to functional classification

The Jacalin-related lectin (JRL) family comprises galactose-binding-type (gJRLs) and mannose-binding-type (mJRLs) lectins. Although the documented occurrence of gJRLs is confined to the family Moraceae, mJRLs are widespread in the plant kingdom. A detailed comparison of sugar-binding specificity was made by frontal affinity chromatography to corroborate the structure-function relationships of the extended mJRL subfamily. Eight mJRLs covering a broad taxonomic range were used: Artocarpin from Artocarpus integrifolia (jackfruit, Moraceae), BanLec from Musa acuminata (banana, Musaceae), Calsepa from Calystegia sepium (hedge bindweed, Convolvulaceae), CCA from Castanea crenata (Japanese chestnut, Fagaceae), Conarva from Convolvulus arvensis (bindweed, Convolvulaceae), CRLL from Cycas revoluta (King Sago palm tree, Cycadaceae), Heltuba from Helianthus tuberosus (Jerusalem artichoke, Asteraceae) and MornigaM from Morus nigra (black mulberry, Moraceae). The result using 103 pyridylaminated glycans clearly divided the mJRLs into two major groups, each of which was further divided into two subgroups based on the preference for high-mannose-type N-glycans. This criterion also applied to the binding preference for complex-type N-glycans. Notably, the result of cluster analysis of the amino acid sequences clearly corresponded to the above specificity classification. Thus, marked correlation between the sugar-binding specificity of mJRLs and their phylogeny should shed light on the functional significance of JRLs.     

一株碱性淀粉酶产生菌Bacillus flexus XJU-3的分离鉴定及酶学特性分析

[目的]从新疆石河子市一处碱性工业污水(pH11.0)分离﹑鉴定高产碱性淀粉酶菌株,并对其所产酶酶学特性进行研究.[方法]在碱性淀粉酶分离培养基上对所分离菌株进行筛选,分离到一株高产碱性淀粉酶菌株,并将其编号XJU-3.应用生理生化试验,脂肪酸含量,16S rDNA序列以及(G C) mol%含量等方法对菌株进行鉴定,同时对XJU-3所产碱性淀粉酶的生物学特性进行研究.[结果] XJU-3可在pH4.0～12.5的LB培养基上生长,最适生长温度37℃.16S rDNA序列构建的系统进化树表明XJU-3与Bacillus flexus类聚在一起,且序列同源性为99%.该菌产生的淀粉酶最适pH10.0,最适温度40℃,且在pH9.0～13.0内有较高活性和稳定性.Co2 和Mg2 能明显提高酶的活性.[结论] XJU-3被鉴定为Bacillus flexus,由于XJU-3与B. flexus DSM 1320T在尿素水解和优势脂肪酸含量上有差异,且具有宽范围pH耐受性,因此XJU-3被认为是B.flexus的一个新菌株.XJU-3所产的碱性淀粉酶酶学特性良好,具有极大的工业应用潜力.     

他克莫司发酵培养基的响应面优化设计

用两水平因子设计考察培养基中的所有七个成分对他克莫司产量的影响大小,选出其中影响较大的葡萄糖、酵母粉、花生粉和NaCl进行最佳浓度范围考察,然后用中心组合方法及响应面分析确定最佳配比,他克莫司的产量提高了55%左右.     

黄土高原不同植被类型区人工林地深层土壤干燥化效应

人工林地土壤干燥化正在日益严重的威胁着黄土高原人工植被建设成效.在黄土高原3个植被类型区广泛观测苹果、刺槐、油松、辽东栎、狼牙刺、沙棘和柠条等23种不同立地和树龄林地深层土壤湿度基础上,比较和分析了各类林地土壤含水量、土壤湿度剖面分布和土壤干燥化强度,定量评价了各类林地深层土壤干燥化效应.研究结果表明:(1)23种林地0～1000 cm土层土壤湿度、土壤贮水量和土壤有效含水量平均值依次为10.84%、1409.8 mm和446.6 mm,明显低于荒草地土壤湿度和当地土壤稳定湿度值,各类林地平均土壤水分过耗量超过500 mm,每年多消耗土壤水分36.8 mm.林地土壤水分过耗量和耗水速度以中部半干旱森林草原区最高,南部半湿润森林区相对较低.林地土壤干燥化速度为:柠条和狼牙刺林地＞油松林地＞刺槐和沙棘林地＞苹果园地和辽东栎林地;(2)除林龄较短的苹果、沙棘和柠条林地外,各类林地在300 cm以下深层土壤湿度明显低于荒草地土壤湿度和土壤稳定湿度值,林地深层土壤湿度表现为阳坡低于阴坡、坡地低于平地,最大耗水深度接近或超过1000 cm.随林龄增长,林地深层土壤湿度逐渐降低,土壤干层逐渐加深和加厚;(3)23种林地土壤干燥化指数平均值为51.6%,达到中度(偏重)干燥化强度,林地土壤干层厚度达到或超过800 cm,随着降水量从半湿润区向半干旱偏旱区趋势性减少,林地土壤干燥化强度趋于强化,土壤干层厚度趋于增加.土壤干燥化强度和土壤干层厚度表现为:油松、辽东栎、狼牙刺和柠条林地＞刺槐林地＞苹果和沙棘林地.     

Repair effect of diabetic ulcers with recombinant human epidermal growth factor loaded by sustained-release microspheres

In this study the w/o/w extraction–evaporation technique was adopted to prepare poly(lactic-co-glycolic acid) (PLGA) microspheres loading recombinant human epidermal growth factor (rhEGF). The micro-spheres were characterized for morphology by transmission electron microscopy (TEM) and particle size distribution. The release performances, the proliferation effects and therapeutic effects of rhEGF-loaded PLGA microspheres were all studied. The results showed that these spherical micro-spheres had a narrow size distribution and a high drug encapsulation efficiency (85.6%). RhEGF-loaded microspheres enhanced the growth rate of fibroblasts and wound healing more efficiently than pure rhEGF. The number of the proliferating cell nuclear antigen (PCNA) in the epidermis layer with the mi-crosphere treatment was significantly larger than those of the control groups. Overall locally sustained delivery of rhEGF from biodegradable PLGA microspheres may serve as a novel therapeutic strategy for diabetic ulcer repair.     

低渗条件下小肠上皮细胞调节性细胞容积减小的离子通道机制

目的:观察人小肠上皮细胞调节性细胞容积减小(RVD)的过程,探讨参与RVD过程的离子通道机制.方法:将培养的人小肠上皮细胞暴露于低渗溶液, 利用电子细胞体积测量系统测定细胞平均容积变化过程和离子通道的参与过程;采用RT-PCR方法检测人小肠上皮细胞上离子通道的表达.结果:人小肠上皮细胞具有良好的RVD功能; 其RVD过程可被氯通道阻断剂NPPB 和钾通道阻断剂四乙铵所阻断; 进一步的研究发现, 中等电导钙激活性钾通道(IK)的特异性阻断剂Clotrimazole (CLT) (1μmol/L)可以明显抑制细胞的RVD过程,而大电导钙激活性钾通道(BK)和小电导钙激活性钾通道(SK)的特异阻断剂iberiotoxin (100 nmol/L)和apamin (100 nmol/L)对RVD过程无任何抑制作用.RT-PCR的结果也显示, 人小肠上皮细胞只有IK表达, 而无SK和BK的表达.结论:人小肠上皮细胞具有RVD功能,RVD过程的完成有赖于氯通道和钾通道的平行激活, 而其中参与容积调节的钾通道是中等电导钙激活型钾通道IK.     

耐高糖高产2,3-丁二醇产酸克雷伯氏杆菌的选育

以产酸克雷伯氏杆菌(Klebsiella oxytoca) ME-UD-3为出发菌株,经紫外线及硫酸二乙酯复合诱变后分别在葡萄糖浓度逐渐提高的液体培养基中进行富集培养,筛选获得了一株耐高糖的2,3-丁二醇高产突变菌株K. oxytoca ME-UD-3-4;该菌株的初始葡萄糖耐受浓度从出发菌株的120g/L提高到300g/L以上,在初始葡萄糖浓度为95 g/L的条件下发酵培养,与出发菌株相比发酵时间缩短了8h,2,3-丁二醇的产量由原来的38.5g/L提高到43.0g/L,生产强度从0.80 g/L·h提高到1.08 g/L·h,转化率达到了理论值的91%。     

Laminin α1 Chain Synthesis in the Mouse Developing Lung: Requirement for Epithelial–Mesenchymal Contact and Possible Role in Bronchial Smooth muscle Development

Laminins, the main components of basement membranes, are heterotrimers consisting of α, β, and γ polypeptide chains linked together by disulfide bonds. Laminins-1 and -2 are both composed of β1 and γ1 chains and differ from each other on their α chain, which is α1 and α2 for laminin-1 and -2, respectively. The present study shows that whereas laminins-1 and -2 are synthesized in the mouse developing lung and in epithelial–mesenchymal cocultures derived from it, epithelial and mesenchymal monocultures lose their ability to synthesize the laminin α1 chain. Synthesis of laminin α1 chain however returns upon re-establishment of epithelial–mesenchymal contact. Cell–cell contact is critical, since laminin α1 chain is not detected in monocultures exposed to coculture-conditioned medium or in epithelial–mesenchymal cocultures in which heterotypic cell–cell contact is prevented by an interposing filter. Immunohistochemical studies on cocultures treated with brefeldin A, an inhibitor of protein secretion, indicated both epithelial and mesenchymal cells synthesize laminin α1 chain upon heterotypic cell– cell contact. In a set of functional studies, embryonic lung explants were cultured in the presence of monoclonal antibodies to laminin α1, α2, and β/γ chains. Lung explants exposed to monoclonal antibodies to laminin α1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle α actin and desmin. Taken together, our studies suggest that laminin α1 chain synthesis is regulated by epithelial–mesenchymal interaction and may play a role in airway smooth muscle development.     

Associations of the uric acid related genetic variants in SLC2A9 and ABCG2 loci with coronary heart disease risk

Background

Multiple studies investigated the associations between serum uric acid and coronary heart disease (CHD) risk. However, further investigations still remain to be carried out to determine whether there exists a causal relationship between them. We aim to explore the associations between genetic variants in uric acid related loci of SLC2A9 and ABCG2 and CHD risk in a Chinese population.

Results

A case–control study including 1,146 CHD cases and 1,146 controls was conducted. Association analysis between two uric acid related variants (SNP rs11722228 in SLC2A9 and rs4148152 in ABCG2) and CHD risk was performed by logistic regression model. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Compared with subjects with A allele of rs4148152, those with G allele had a decreased CHD risk and the association remained significant in a multivariate model. However, it altered to null when BMI was added into the model. No significant association was observed between rs11722228 and CHD risk. The distribution of CHD risk factors was not significantly different among different genotypes of both SNPs. Among subjects who did not consume alcohol, the G allele of rs4148152 showed a moderate protective effect. However, no significant interactions were observed between SNP by CHD risk factors on CHD risk.

Conclusions

There might be no association between the two uric acid related SNPs with CHD risk. Further studies were warranted to validate these results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0162-7) contains supplementary material, which is available to authorized users.     

ART患者早期流产组织染色体异常及相关因素分析

目的:分析ART患者早期流产组织染色体异常及其相关影响因素。方法:回顾性分析2013-2017年ART患者行早期流产组织染色体检查的409例样本,分析胚胎染色体非整倍性发生及其与女方年龄、不孕年限、不孕因素、促排卵指标之间的关系。结果:ART流产患者中,流产组织染色体非整倍性发生率为57.46%,发生频次以16三体占比最高(23.95%),其次是22三体(13.45%)及Turner(9.24%)。流产组织染色体非整倍性患者平均年龄高于染色体整倍性患者(P0.001)。16三体组患者年龄低于22三体(P0.01)及Turner组(P0.05)。16三体组患者平均Gn使用量低于22三体组(P0.05)。16三体组患者移植15天血HCG值低于22三体(P0.05)及Turner组(P0.01)。结论:ART患者流产组织染色体非整倍性与女方年龄正相关,但16三体及Turner的发生与女方年龄相关性不大,且16三体更容易引发早期流产。