Oxalate production at different initial Pb²+ concentrations and the influence of oxalate during solid-state fermentation of straw with Phanerochaete chrysosporium

The production of oxalate at different initial Pb²⁺ concentrations during solid-state fermentation of straw with Phanerochaete chrysosporium was investigated. It was found that the maximal peak value of oxalate concentration (22.84 mM) was detected at the initial Pb²⁺ concentration of 200 mg kg⁻¹ dry straw, while the minimum (15.89 mM) at the concentration of 600 mg Pb²⁺ kg⁻¹ dry straw, and at moderate concentration of Pb²⁺ the capability of oxalic acid secretion was enhanced. In addition, it was also found that more oxalic acid accumulation went together with better Pb²⁺ passivation effect and higher manganese peroxidase (MnP) activity. The present findings will improve the understandings of the interactions of heavy metals with white-rot fungi and the role of oxalate in lignin degradation system, which could provide useful references for more efficient treatment of Pb-contaminated lignocellulosic waste.     

克隆鸭乙型肝炎病毒DNA双体体内转染的研究

用一种含头尾相连DHBVDNA双体的质粒体内转染2日龄芙蓉鸭,大多数鸭（86％）产生了短暂病毒血症。血清DHBs／preSAg和DHBVDNA于转染后第9天出现,第12～14天达峰值,第28天时多数转阴;少数鸭的病毒血症可持续50天以上。转染鸭肝组织中也检测到复制中间型DHBVDNA的存在。用转染鸭病毒血症期的血清作磷钨酸负染电镜观察,找到了完整的DHBV病毒颗粒,并且用此血清腹腔注射1日龄鸭,60％的鸭被感染成功,证明体内转染后有生物活性的DHBV病毒颗粒的产生。该研究方法的建立．对于研究DHBV变异株．DHBV基因结构与功能的关系等,均有一定理论意义及应用价值。     

Methylnaltrexone prevents morphine-induced kaolin intake in the rat

Opioids are frequently used analgesics, and emesis is a common opioid-induced adverse effect. Methylnaltrexone, a peripheral opioid antagonist, has the potential to block the undesired effects of opioids that are mediated by peripheral receptors while sparing the analgesic effect. We used a rat model of simulated emesis or pica to study if methylnaltrexone decreases morphine induced-kaolin consumption. We observed that after morphine administration, kaolin intake increased significantly compared to intake in the vehicle group, and the increase could be attenuated by ondansetron administration. Methylnaltrexone dose-dependently reduced kaolin ingestion induced by morphine. Morphine and methylnaltrexone did not significantly affect food intake and body weight in the experimental animals. Our data suggest that methylnaltrexone has therapeutic value in treating opioid-induced nausea and vomiting.     

吡哆胺对糖尿病大鼠视皮质AGE-RAGE系统的影响

目的观察吡哆胺对糖尿病大鼠视皮质高级糖基化终末产物(AGE)及其受体(RAGE)表达的影响,探讨吡哆胺对视皮质的保护作用。方法健康SD大鼠随机分为正常对照组(NC组)、糖尿病未治疗组(DM组)、糖尿病吡哆胺治疗组(PM组)和氨基胍治疗对照组(AG组)各20只,用链脲佐菌素(STZ)建立糖尿病模型,PM组和AG组分别于造模成功后第二天开始予吡哆胺和氨基胍灌胃。各组于治疗4w和12w后取材,用酶联免疫吸附(ELISA)法定量检测大鼠视皮质中AGEs含量,荧光免疫组化及图像分析半定量检测各组视皮质RAGE的表达。结果糖尿病治疗组和未治疗组血糖无显著性差异。4w时各组AGEs含量无明显差异,12w时PM组视皮质中AGEs含量与AG组、NC组比较差异无统计学意义,与DM组相比显著降低,差异具有统计学意义(P0.05)。PM组视皮质中RAGE表达比DM组显著减少,差异具有统计学意义(P0.05),但高于NC组(P0.05)。结论糖尿病大鼠12w后视皮质中AGEs含量和RAGE的表达高于正常对照组,吡哆胺类似氨基胍可减少AGEs的堆积,还能抑制RAGE的表达,减轻AGEs-RAGE通路作用导致的组织损伤,对视皮质具有一定的保护作用。     

ITMSQ: A software tool for N‐ and C‐terminal fragment ion pairs based isobaric tandem mass spectrometry quantification

Tandem MS (MS2) quantification using the series of N‐ and C‐terminal fragment ion pairs generated from isobaric‐labelled peptides was recently considered an accurate strategy in quantitative proteomics. However, the presence of multiplexed terminal fragment ion in MS2 spectra may reduce the efficiency of peptide identification, resulting in lower identification scores or even incorrect assignments. To address this issue, we developed a quantitative software tool, denoted isobaric tandem MS quantification (ITMSQ), to improve N‐ and C‐terminal fragment ion pairs based isobaric MS2 quantification. A spectrum splitting module was designed to separate the MS2 spectra from different samples, increasing the accuracy of both identification and quantification. ITMSQ offers a convenient interface through which parameters can be changed along with the labelling method, and the result files and all of the intermediate files can be exported. We performed an analysis of in vivo terminal amino acid labelling labelled HeLa samples and found that the numbers of quantified proteins and peptides increased by 13.64 and 27.52% after spectrum splitting, respectively. In conclusion, ITMSQ provides an accurate and reliable quantitative solutionfor N‐ and C‐terminal fragment ion pairs based isobaric MS2 quantitative methods.     

铅锌砷复合污染对水稻生长的影响

铅锌砷复合污染对水稻生长的影响谢正苗,黄昌勇（浙江农业大学土化系杭州,３１００２９）ＥＦＦＥＣＴＳＯＦＣＯＭＢＩＮＥＤＰＯＬＬＵＴＩＯＮＯＦＬＥＡＤＺＩＮＣＡＲＳＥＮＩＣＯＮＲＩＣＥＧＲＯＷＴＨＸｉｅＺｈｅｎｇｍｉａｏＨｕｎａｇＣｈａｎｇｙｏｎｇ（Ｚ...     

Arabidopsis Villins Promote Actin Turnover at Pollen Tube Tips and Facilitate the Construction of Actin Collars

Apical actin filaments are crucial for pollen tube tip growth. However, the specific dynamic changes and regulatory mechanisms associated with actin filaments in the apical region remain largely unknown. Here, we have investigated the quantitative dynamic parameters that underlie actin filament growth and disappearance in the apical regions of pollen tubes and identified villin as the major player that drives rapid turnover of actin filaments in this region. Downregulation of Arabidopsis thaliana VILLIN2 (VLN2) and VLN5 led to accumulation of actin filaments at the pollen tube apex. Careful analysis of single filament dynamics showed that the severing frequency significantly decreased, and the lifetime significantly increased in vln2 vln5 pollen tubes. These results indicate that villin-mediated severing is critical for turnover and departure of actin filaments originating in the apical region. Consequently, the construction of actin collars was affected in vln2 vln5 pollen tubes. In addition to the decrease in severing frequency, actin filaments also became wavy and buckled in the apical cytoplasm of vln2 vln5 pollen tubes. These results suggest that villin confers rigidity upon actin filaments. Furthermore, an observed decrease in skewness of actin filaments in the subapical region of vln2 vln5 pollen tubes suggests that villin-mediated bundling activity may also play a role in the construction of actin collars. Thus, our data suggest that villins promote actin turnover at pollen tube tips and facilitate the construction of actin collars.     

Synthesis of novel D-ring fused 7'-aryl-androstano[17,16-d][1,2,4] triazolo[1,5-a]pyrimidines

The preparation of novel steroidal heterocycles containing the 7-aryl-substituted 1,2,4-triazolo[1,5-a]pyrimidine moiety fused to the 16,17-positions of the steroid nucleus is described. The Aldol reaction of 4-aza-androst-3,17-dione (1a) and dehydroepiandrosterone (DHEA, 1b) with aromatic aldehydes was catalyzed by KF/Al(2)O(3) to give the corresponding 3-oxo-4-aza-5α- and 3β-hydroxy-5-en-16-arylidene-17-ketosteroids (2a-r). Subsequently, the intermediates 2a-r reacted with dinucleophilic 3-amino-1,2,4-triazole in presence of t-BuOK to afford the title compounds (3a-r). All the synthesized heterosteroids are new and are currently being evaluated for their biological activities.