玉米素核苷的酶标免疫测定法

牛血清白蛋白-玉米素核苷(BSA-ZR)的兔抗血清对玉米素核苷具有很高的亲和性,而且专一性强,除了玉米素外,对其它一些细胞分裂素如激动素(KT)的交叉反应甚微。用辣根过氧化物酶(HRP)作为标记物的酶标免疫法,由于它的灵敏度高,相当于几十毫克量的样品就可以测出细胞分裂素的含量。测定范围在0.25—50pmol之间,测定范围较广。由于该方法专一性高,植物组织的粗提取物可以直接用于测定。避免了提取分离的繁琐程序,使得测定方法较简便、快速,可成批进行,适用于一般实验室。用该方法测得风信子(Hyacinthus orientalis L.)各部分的细胞分裂含量(以玉米素核苷计)在10—60×10~(-9)克/克鲜重,即10—60ng/g F.W.。     

Virtual screening,selection and development of a benzindolone structural scaffold for inhibition of lumazine synthase

Virtual screening of a library of commercially available compounds versus the structure of Mycobacterium tuberculosis lumazine synthase identified 2-(2-oxo-1,2-dihydrobenzo[cd]indole-6-sulfonamido)acetic acid (9) as a possible lead compound. Compound 9 proved to be an effective inhibitor of M. tuberculosis lumazine synthase with a K_i of 70 μM. Lead optimization through replacement of the carboxymethylsulfonamide sidechain with sulfonamides substituted with alkyl phosphates led to a four-carbon phosphate 38 that displayed a moderate increase in enzyme inhibitory activity (K_i 38 μM). Molecular modeling based on known lumazine synthase/inhibitor crystal structures suggests that the main forces stabilizing the present benzindolone/enzyme complexes involve π–π stacking interactions with Trp27 and hydrogen bonding of the phosphates with Arg128, the backbone nitrogens of Gly85 and Gln86, and the side chain hydroxyl of Thr87.     

Next-generation sequencing to identify candidate genes and develop diagnostic markers for a novel Phytophthora resistance gene, <Emphasis Type="Italic">RpsHC18</Emphasis>, in soybean

Key message

A novel Phytophthora sojae resistance gene RpsHC18 was identified and finely mapped on soybean chromosome 3. Two NBS–LRR candidate genes were identified and two diagnostic markers of RpsHC18 were developed.

Abstract

Phytophthora root rot caused by Phytophthora sojae is a destructive disease of soybean. The most effective disease-control strategy is to deploy resistant cultivars carrying Phytophthora-resistant Rps genes. The soybean cultivar Huachun 18 has a broad and distinct resistance spectrum to 12 P. sojae isolates. Quantitative trait loci sequencing (QTL-seq), based on the whole-genome resequencing (WGRS) of two extreme resistant and susceptible phenotype bulks from an F_2:3 population, was performed, and one 767-kb genomic region with ΔSNP-index ≥ 0.9 on chromosome 3 was identified as the RpsHC18 candidate region in Huachun 18. The candidate region was reduced to a 146-kb region by fine mapping. Nonsynonymous SNP and haplotype analyses were carried out in the 146-kb region among ten soybean genotypes using WGRS. Four specific nonsynonymous SNPs were identified in two nucleotide-binding sites–leucine-rich repeat (NBS–LRR) genes, RpsHC18-NBL1 and RpsHC18-NBL2, which were considered to be the candidate genes. Finally, one specific SNP marker in each candidate gene was successfully developed using a tetra-primer ARMS-PCR assay, and the two markers were verified to be specific for RpsHC18 and to effectively distinguish other known Rps genes. In this study, we applied an integrated genomic-based strategy combining WGRS with traditional genetic mapping to identify RpsHC18 candidate genes and develop diagnostic markers. These results suggest that next-generation sequencing is a precise, rapid and cost-effective way to identify candidate genes and develop diagnostic markers, and it can accelerate Rps gene cloning and marker-assisted selection for breeding of P. sojae-resistant soybean cultivars.

     

Comparison of the Efficacy of Rosuvastatin versus Atorvastatin in Preventing Contrast Induced Nephropathy in Patient with Chronic Kidney Disease Undergoing Percutaneous Coronary Intervention

Objectives

We prospectively compared the preventive effects of rosuvastatin and atorvastatin on contrast-induced nephropathy (CIN) in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI).

Methods

We enrolled 1078 consecutive patients with CKD undergoing elective PCI. Patients in Group 1 (n = 273) received rosuvastatin (10 mg), and those in group 2 (n = 805) received atorvastatin (20 mg). The primary end-point was the development of CIN, defined as an absolute increase in serum creatinine ≥0.5 mg/dL, or an increase ≥25% from baseline within 48–72 h after contrast medium exposure.

Results

CIN was observed in 58 (5.4%) patients. The incidence of CIN was similar in patients pretreated with either rosuvastatin or atorvastatin (5.9% vs. 5.2%, p = 0.684). The same results were also observed when using other definitions of CIN. Clinical and procedural characteristics did not show significant differences between the two groups (p>0.05). Additionally, there were no significant inter-group differences with respect to in-hospital mortality rates (0.4% vs. 1.5%, p = 0.141), or other in-hospital complications. Multivariate logistic regression analysis revealed that rosuvastatin and atorvastatin demonstrated similar efficacies for preventing CIN, after adjusting for potential confounding risk factors (odds ratio = 1.17, 95% confidence interval, 0.62–2.20, p = 0.623). A Kaplan–Meier survival analysis showed that patients taking either rosuvastatin or atorvastatin had similar incidences of all-cause mortality (9.4% vs. 7.1%, respectively; p = 0.290) and major adverse cardiovascular events (29.32% vs. 23.14%, respectively; p = 0.135) during follow-up.

Conclusions

Rosuvastatin and atorvastatin have similar efficacies for preventing CIN in patients with CKD undergoing PCI.     

Effects of Dietary Clostridium butyricum on the Growth,Digestive Enzyme Activity,Antioxidant Capacity,and Resistance to Nitrite Stress of Penaeus monodon

Probiotics and Antimicrobial Proteins - The present study investigated the effects of the dietary probiotic Clostridium butyricum (CB) on the growth, intestine digestive enzyme activity,...     

Disruption of the SH2-B gene causes age-dependent insulin resistance and glucose intolerance

Insulin regulates glucose homeostasis by binding and activating the insulin receptor, and defects in insulin responses (insulin resistance) induce type 2 diabetes. SH2-B, an Src homology 2 (SH2) and pleckstrin homology domain-containing adaptor protein, binds via its SH2 domain to insulin receptor in response to insulin; however, its physiological role remains unclear. Here we show that SH2-B was expressed in the liver, skeletal muscle, and fat. Systemic deletion of SH2-B impaired insulin receptor activation and signaling in the liver, skeletal muscle, and fat, including tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) and IRS2 and activation of the phosphatidylinositol 3-kinase/Akt and the Erk1/2 pathways. Consequently, SH2-B-/- knockout mice developed age-dependent hyperinsulinemia, hyperglycemia, and glucose intolerance. Moreover, SH2-B directly enhanced autophosphorylation of insulin receptor and tyrosine phosphorylation of IRS1 and IRS2 in an SH2 domain-dependent manner in cultured cells. Our data suggest that SH2-B is a physiological enhancer of insulin receptor activation and is required for maintaining normal insulin sensitivity and glucose homeostasis during aging.