不同剂量STZ与高脂饲料联合诱导糖尿病小鼠模型

探讨不同剂量链脲霉素(streptozotocin,STZ)联合高脂膳食建立2型糖尿病小鼠模型的效果。选择C57BL/6J小鼠,5周龄开始饲喂高脂饲料,持续10周,将膳食诱导的肥胖(dietinduced obesity,DIO)小鼠随机分为对照组及3个试验组[分别为试验组A(腹腔注射STZ 50mg/kg)、B(腹腔注射STZ 70mg/kg)、C(腹腔注射STZ 100mg/kg)],每组均为10只动物。试验组小鼠腹腔注射STZ后与对照组一起继续饲喂高脂2周。分别检测各组小鼠造模前后空腹血糖,胰岛素水平及成模后糖耐量。结果表明试验A、B、C 3组的成模率分别为70%、90%、100%,其血糖含量(分别为229.4±8.72、349.4±6.71、432.5±11.0 mg/dL)显著地高于对照组(168.7±4.18mg/dL);其血浆胰岛素含量(分别为1.83±0.288,0.659±0.058,0.438±0.023ng/mL)明显低于对照组(2.95±0.218ng/mL)。不同STZ剂量可诱导不同程度的糖尿病症状。     

An assessment of 1,4,6-trimethylnaphthalene as a sprout suppressant for stored potato tubers

Summary 1,4,6-trimethylnaphthalene (1,4,6-TMN) proved to be an effective potato sprout suppressant in bioassays based on both excised cultured shoot-tips and intact tubers. Trials were done using 500 kg of tubers stored in storage cabinets with internal air circulations and renewal characteristics similar to commercial stores. The compound, supplied at up to 30 mg/kg tubers as a liquid fog, controlled sprout growth for three months at 10°C. Analysis of residue levels in tuber peel at the end of the storage period showed values of up to 6 ppm and demonstrated even distribution of the compound. Subsequent treatments with 11 mg/kg tubers at weeks 14 and 26, enabled the useful storage life to be extended to 30 weeks with good control of sprout growth. Comparison of 1,4,6-TMN with commercial suppressants under identical storage conditions showed that 1,4,6-TMN was at least as effective as chlorpropham (CIPC) and Tecnazene (TCNB) over a 16-week period at 10°C.

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Zusammenfassung Die verdampfbare Fraktion von Kartoffelknollen ergab eine Reihe von methylierten Naphthalinen, in erster Linie Di-und Trimethylnaphthaline. 1,4,6-Trimethylnaphthalin (1,4,6-TMN) erwies sich in zwei Biotest-Systemen (Abb. 1 und 2) als effektiver Keimhemmer. Die physikalischen Eigenschaften von 1,4,6-TMN machen wahrscheinlich, dass die Charakteristika für Vorkommen und Verteilung für 1,4-Dimethylnaphthalin am günstigsten w?ren. Die Tests wurden in kleineren (500 kg), speziell konstruierten Beh?ltern mit Belüftungs-verh?ltnissen durchgeführt, die denen bei kommerzieller Lagerung entsprechen. Tabelle 2 zeigt, dass 29 mg/kg 1,4,6-TMN, als Nebel appliziert, fast komplette Verhinderung der Keimung mit Rückstandsh?hen von 6–7 ppm an den Knollenoberfl?chen ergab. Tabelle 3 zeigt einen weiteren, gleichartigen Versuch, bei dem 25 mg/kg 1,4,6-TMN appliziert wurden, mit einer Hemmung der Keimung bis zu 14 Wochen. Nachfolgende Behandlungen mit 11 mg/kg in der 14. und 26. Woche verl?ngerten die Periode der Hemmung bis zu 30 Wochen. Tabellen 4 und 5 zeigen einen Vergleich von 1,4,6-TMN (25 mg/kg) mit CIPC (25 mg/kg) und Tecnazene (135 mg/kg). Es ergab sich zumindest der gleiche Effekt wie bei kommerziellen Keimhemmern. Ein Vergleich der Rückstandsverteilung innerhalb eines Kartoffelstapels ergeben auf den Knollen einen sehr engen Schwankungsbereich für 1,4,6-TMN (zwischen 3,6 und 3,8 ppm) und viel st?rkere Schwankungen in der H?he bei den anderen Hemmern. Auf der Basis dieser Versuche erscheint weitere kommerzielle Untersuchung von 1,4,6-Trimethylnaphthalin als gerechtfertigt.

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Résumé On a montré que la fraction volatile des tubercules de pommes de terre contient une série de naphthalènes méthylés, notamment des di-et triméthylnaphthalène. Dans deux essais biologiques, le 1,4,6-triméthylnaphthalène (1,4,6-TMN) s'est révélé être un inhibiteur de germination efficace. Les propriétés physiques du 1,4,6-TMN suggèrent que ses performances et sa répartition dans les locaux pourraient être supérieures à celles du 1,4-diméthylnaphthalène. Ce produit a été expérimenté à petite échelle (500 kg) dans des cellules spécialement concues pour que les caractéristiques de ventilation soient similaires à celles existant dans les magasins de conservation. Le tableau 2 montre que la dose de 29 mg/kg de 1,4,6-TMN appliquée par brumisation inhibe presque complètement la germination avec un taux de résidus de 6 à 7 ppm sur la surface des tubercules. Le tableau 3 montre les résultats d'un essai analogue avec 25 mg/kg de 1,4,6-TMN dans lequel l'inhibition de la germination était maintenue pendant 14 semaines. Un traitement postérieur de 11 mg/kg effectué après 14 et 26 semaines prolongeait la période d'inhibition jusqu'à la trentième semaine. Les tableaux 4 et 5 mettent en comparaison le 1,4,6-TMN (25 mg/kg) avec le CIPC (25 mg/kg) et le Technazène (135 mg/kg). On observe que celui-ci s'avère aussi efficace que les inhibiteurs de germination du commerce. L'étude de la répartition des résidus à l'intérieur du tas de pommes de terre (tableau 5) met en évidence un très faible taux de 1,4,6-TMN (entre 3,6 et 3,8 ppm) et une variation beaucoup plus grande dans les concentrations des autres inhibiteurs. En se basant sur les resultats de ces essais, une étude commerciale plus poussée du 1,4,6-triméthylnaphthalène parait justifiée.

     

Accumulation of sugars in microtubers of potato node cuttings (cv. Kennebec) during cold storage

Summary Microtubers of potato cultivar Kennebec were stored for two months at 2 or 8°C and sampled at selected intervals for the determination of glucose, fructose, sucrose and sprout weight. The aim of this experiment was to determine whether these microtubers show the same response to storage temperature with respect to sweetening as field grown tubers. During storage at 2 °C, reducing sugars and sucrose increased rapidly to a concentration of over 1.0 and 0.7 g/100 g fresh weight, respectively. In contrast, in tubers kept at 8°C, only a relatively slight increase in reducing sugar concentration to 0.3 g/100 g fresh weight was observed and sucrose concentration remained virtually the same.     

拉曼光谱法无损检测蜂蜜中的果糖和葡萄糖含量

应用拉曼光谱结合化学计量学方法对蜂蜜果糖和葡萄糖含量进行了定量分析。用自适应迭代重加权惩罚最小二乘(adaptive iteratively reweighted penalized least squares,airPLS)算法进行基线校正,用竞争性自适应重加权采样(competitive adaptive reweighted sampling,CARS)算法筛选变量,分别用线性的偏最小二乘(partial least squares,PLS)回归算法和非线性的支持向量机(support vector machines,SVM)回归算法建立定量校正模型,并进行预测。2种模型都有较好的预测结果。对果糖,SVM模型预测值与高效液相色谱法(high performance liquid chromatography,HPLC)测定值的相关系数(R)和预测均方根误差(root mean square error of prediction,RMSEP)分别为0.902和1.401,略优于PLS模型(R为0.892,RMSEP为1.604);对葡萄糖,PLS模型的R和RMSEP分别为0.968和0.669,优于SVM模型(R为0.933,RMSEP为1.410)。结果表明拉曼光谱结合化学计量学方法可快速无损测定蜂蜜果糖和葡萄糖含量。     

Structural-Based Optimizations of the Marine-Originated Meridianin C as Glucose Uptake Agents by Inhibiting GSK-3β

Glycogen synthase kinase 3β (GSK-3β) is a widely investigated molecular target for numerous diseases, and inhibition of GSK-3β activity has become an attractive approach for the treatment of diabetes. Meridianin C, an indole-based natural product isolated from marine Aplidium meridianum, has been reported as a potent GSK-3β inhibitor. In the present study, applying the structural-based optimization strategy, the pyrimidine group of meridianin C was modified by introducing different substituents based on the 2-aminopyrimidines-substituted pyrazolo pyridazine scaffold. Among them, compounds B29 and B30 showed a much higher glucose uptake than meridianin C (<5%) and the positive compound 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8, 16%), with no significant toxicity against HepG2 cells at the same time. Furthermore, they displayed good GSK-3β inhibitory activities (IC₅₀ = 5.85; 24.4 μM). These results suggest that these meridianin C analogues represent novel lead compounds with therapeutic potential for diabetes.     

Carbon-iron coupling reduced N2O emissions via promoting the conversion to N2 in paddy soils

The influence of redox reactions involving carbon-iron coupling (organic carbon and iron oxides) on nitrous oxide (N₂O) production in paddy soils remains poorly understood. In this study, two microcosm experiments were conducted to investigate the effects of carbon-iron coupling on N₂O emissions, and the underlying mechanisms were verified using quantitative denitrification functional genes (nirS, nirK, nosZI and nosZII) and high-throughput sequencing. The results showed that ferrihydrite (iron) significantly promoted N₂O-N emissions (p < 0.05) after adding ammonium nitrogen, while glucose (carbon) significantly inhibited N₂O-N emissions (p < 0.05). Carbon-iron coupling significantly decreased N₂O-N emissions (p < 0.05) but did not affect soil total nitrogen loss and increased nitrogen (N₂) emissions. After adding high concentrations of acetylene (10% C₂H₂), the N₂O-N emissions from carbon-iron coupling treatment increased significantly from 6.4 to 11.9 mg N kg⁻¹ (p < 0.05), which confirmed that the carbon-iron coupling reduced the N₂O emissions by promoting the conversion of N₂O to N₂. The mechanisms behind carbon-iron coupling promoting complete denitrification and reducing N₂O emissions were attributed to glucose promoting iron reduction and carbon-iron coupling enhancing the abundance of nosZI (42.7%) and nosZII (16.6%).     

Pathogenicity of Colletotrichum species causing anthracnose of Capsicum in Asia

Anthracnose of chili is caused by a complex of Colletotrichum species, with recent surveys reporting at least 28 different species implicated. However, there have been very few studies to identify the relative pathogenicity of the various species or to optimize a bioassay to assess pathogenicity. A detached Capsicum fruit bioassay to determine the pathogenicity of a diverse geographical range of isolates of Colletotrichum scovillei showed fruit maturity, host genotype, and inoculation method all interact to affect infection and rate of lesion development. On Capsicum annuum ‘Bangchang’ fruit wounded prior to inoculation, pathogenicity was consistent regardless of fruit maturity. In contrast, without wounding there was variability in pathogenicity. On the relatively resistant host Capsicum chinense PBC932, pathogenicity was dependent on both the inoculation method and the maturity stage of the fruit. In addition, lack of correlation in pathogenicity of isolates between the two Capsicum lines indicated that there was host–isolate specialization that would make prediction of pathogenicity of isolates on host difficult. In a further study, 10 species of Colletotrichum isolated from diseased chili fruits in Asia caused anthracnose symptoms on C. annuum ‘Bangchang’ under all testing conditions, with large differences in aggressiveness. C. chinense PBC932 was generally more resistant to all the species, with smaller lesions produced in different host conditions. Colletotrichum javanense and C. scovillei were highly aggressive relative to other species, especially when inoculated on nonwounded fruit. Pathotype differences were identified within multiple isolates of C. scovillei and C. siamense, the two most frequently identified pathogenic species on chili.     

漾濞核桃病害病原菌的分离及药物抑菌试验

从漾濞核桃染病的枝、叶上分离得到17个纯培养菌株,其中YB001和YB009被鉴定为拟盘多毛孢属(Pestalotiotiopsistey)的真菌,YB005为单端孢属(Trichthecium)的真菌,YB018为枝孢属(C ladosporium)的真菌。室内药剂抑菌实验的结果表明:甲基托布津对YB001和YB009菌的抑制效果很好,茂生对YB016和YB017菌的抑制效果很好。     

基于RNA-Seq数据分析葡萄糖诱导绵羊卵泡颗粒细胞衰老的差异表达基因

【目的】 探讨葡萄糖对绵羊卵泡颗粒细胞衰老及其基因表达的影响。【方法】 将原代分离培养的绵羊卵泡颗粒细胞分别用含17.5(H组)和2 mmol/L(L组)葡萄糖的培养基进行体外培养, 细胞处理72 h后, 利用β-半乳糖苷酶染色检测细胞衰老, 采用RNA-Seq技术进行转录组测序, 对差异表达基因进行GO功能富集分析和KEGG通路富集分析, 并用实时荧光定量PCR验证锚定蛋白重复域蛋白1(ANKRD1)、白细胞介素8(IL-8)、催产素(OXT)、烟酰胺腺嘌呤二核苷酸磷酸氧化酶4(NOX4)基因的表达量。【结果】 H组β-半乳糖苷酶染色阳性细胞率极显著高于L组(P<0.01)。转录组测序结果显示, 两组间存在401个差异表达基因, 其中上调基因153个, 下调基因248个, 高糖诱导的细胞异常相关基因9个, 细胞周期相关基因6个。GO功能富集分析发现, 差异表达基因参与了细胞过程、生物调节、代谢过程、多细胞生物过程及细胞运动等生物过程, 在细胞成分上主要富集在胞外区、膜、突触、细胞器及超分子复合体等, 在分子功能主要富集在催化活性、整合、转运活性、分子功能调节剂及结构分子活性等。KEGG信号通路富集分析发现, 差异表达基因主要富集在糖尿病并发症中的晚期糖基化产物(AGE)-晚期糖基化终末产物受体(RAGE)信号通路、肿瘤坏死因子(TNF)信号通路、过氧化物酶体增殖物激活受体(PPAR)信号通路等。实时荧光定量PCR结果表明, 与L组相比, H组IL-8基因表达水平极显著上调(P<0.01), ANKRD1基因表达水平显著上调(P<0.05), OXT基因表达水平极显著下调(P<0.01), NOX4基因表达量呈上升趋势, 但差异不显著(P>0.05), 实时荧光定量PCR结果与转录组测序结果一致。【结论】 17.5 mmol/L葡萄糖可诱导绵羊卵泡颗粒细胞衰老及衰老相关基因表达变化, 为葡萄糖诱导颗粒细胞衰老的功能和分子机制提供了依据。     

调控进入小肠蛋白质和淀粉水平对肉牛氮代谢及血液生化指标的影响

用4头装有瘤胃和真胃瘘管的成年肉牛 ,采用4×4完全拉丁方试验设计 ,研究了4种处理 :A(1.2M羊草基础日粮 +食入普通豆粕710g+食入淀粉320g)、B(1.2M羊草基础日粮 +食入保护豆粕710g+食入淀粉320g)、C(1.2M羊草基础日粮 +食入普通豆粕710g +真胃灌注淀粉320g)和D(1.2M羊草基础日粮 +食入保护豆粕710g+真胃灌注淀粉320g) ,对可消化氮转化为沉积氮的效率(RN/DN)、氮沉积量(RN)和血液生化指标的影响。结果表明 :(1)RN(g/d)、RN/DN( %)、血糖(G)、胰岛素(INS)和生长激素(GH)浓度随着进入真胃(小肠)非降解养分(蛋白质、淀粉)量的增加而提高。D处理(非降解蛋白200g +真胃灌注淀粉320g)的RN(g/d)比A、B、C处理分别提高63.24%(P<0.01)、56.32 %(P<0.01)和22.62 %(P<0.05)。(2)血清中GH、INS和G含量与RN(g/d)和RN/DN( %)存在线性正相关关系。