Retinoblastoma,gross internal malformations,and deletion 13q14→q31

Summary A male patient with an interstitial deletion 13q14q31 is described. Our necropsy findings included a left retinoblastoma and several gross internal malformations. In this paper we reaffirm that band 13q14 is involved in cases of retinoblastoma and we propose, after studying accompanying cases of total or partial long arm trisomies 13, that the loss of specific 13q bands, from 13q14 to 13q31 is responsible for the congenital defects we are describing.     

Mass spectrometric analysis of protein histidine phosphorylation

Summary. Protein histidine phosphorylation is now recognized as an important form of post-translational modification. The acid-lability of phosphohistidine has meant that this phosphorylation has not been as well studied as serine/threonine or tyrosine phosphorylation. We show that phosphohistidine and phosphohistidine-containing phosphopeptides derived from proteolytic digestion of phosphohistone H4 are detectable by ESI-MS. We also demonstrate reverse-phase HPLC separation of these phosphopeptides and their detection by MALDI-TOF-MS.     

内生Bacillus svelezensis HBB5菌株发酵盾叶薯蓣产薯蓣皂苷元的研究

目的探讨内生Bacillus svelezensis HBB5菌株发酵宿主植物盾叶薯蓣产薯蓣皂苷元的能力。方法接种内生B.svelezensis HBB5及B.subtilis ATCC 6633菌株(0.35×10~8 CFU/mL)至含盾叶薯蓣地下茎组织的液体培养基,32℃、165~185 r/min连续发酵108 h,检测发酵液细菌、pH、淀粉、麦芽糖、葡萄糖、淀粉酶(α-amylase)及薯蓣皂苷元溶出率等指标。结果内生B.svelezensis HBB5菌株有较强的酸、碱耐受力[pH(4.8±0.2)~(8.4±0.2)],相比B.subtilis ATCC 6633[pH(5.2±0.2)~(8.7±0.2)]差异不明显;前者达峰值生长量(60×10~(8±2) CFU/mL)明显高于后者(32×10~(8±2) CFU/mL)。发酵36~60 h时,B.svelezensis HBB5、B.subtilis ATCC 6633菌株发酵液的淀粉、麦芽糖、葡萄糖浓度达峰值,分别为(37.41±3.12)、(27.83±2.14)ng/mL,(21.06±1.25)、(16.54±1.08)ng/mL,(54.33±3.12)、(36.65±2.10)ng/mL,前者均高于后者。同时,B.svelezensis HBB5菌株维持高的α-amylase酶活性及薯蓣皂苷元溶出率。结论内生B.svelezensis HBB5菌株拥有较强的耐酸碱、降解淀粉、提高薯蓣皂苷元溶出的能力,为工业生产薯蓣皂苷元提供了一个新的方法。     

Steady‐state and time‐resolved fluorescence of tetramethylrhodamine attached to DNA: correlation with DNA sequences

Time‐resolved fluorescence as well as steady‐state absorption and fluorescence were detected in order to study the interactions between tetramethylrhodamine (TAMRA) and DNA when TAMRA was covalently labeled on single‐ and double‐stranded oligonucleotides. Fluorescence intensity quenching and lifetime changes were characterized and correlated with different DNA sequences. The results demonstrated that the photoinduced electron transfer interaction between guanosine residues and TAMRA introduced a short lifetime fluorescence component when guanosine residues were at the TAMRA‐attached terminal of the DNA sequences. The discrepancy of two‐state and three‐state models in previous studies was due to the DNA sequence selection and sensitivity of techniques used to detect the short lifetime component. The results will help the design of fluorescence‐based experiments related to a dye labeled probe. Copyright © 2012 John Wiley & Sons, Ltd.     

氯氟氰菊酯与阿维菌素增效混配制剂对美洲斑潜蝇的防治效果

低毒化学杀虫剂氯氟氰菊酯与生物源农药阿维菌素混配,通过其对美洲斑潜蝇室内毒力实验,测定共毒系数CTC为161～232,处于明显增效范围内。据此确定最佳配比,配制此增效混剂2%渗透型可湿性粉剂。在北京、山东两地防治美洲斑潜蝇幼虫的田间试验表明药效优良,制剂用量50 g/667m²药后3、7、11天两地区校正防效分别为85.26%～90.76%和86.74%～94.02%,制剂用量25g/667m2两地区相应防效分别为75.28%～85.17%、79.96%～88.68%。该增效混剂防治斑潜蝇速效性和持效性皆佳,成本有所下降,使用可湿粉与乳油相比较,可减少投放入环境的化学品数量,以减少环境污染。     

Hypoxic conditioned medium derived from bone marrow mesenchymal stromal cells protects against ischemic stroke in rats

In recent years, studies have shown that the secretome of bone marrow mesenchymal stromal cells (BMSCs) contains many growth factors, cytokines, and antioxidants, which may provide novel approaches to treat ischemic diseases. Furthermore, the secretome may be modulated by hypoxic preconditioning. We hypothesized that conditioned medium (CM) derived from BMSCs plays a crucial role in reducing tissue damage and improving neurological recovery after ischemic stroke and that hypoxic preconditioning of BMSCs robustly improves these activities. Rats were subjected to ischemic stroke by middle cerebral artery occlusion and then intravenously administered hypoxic CM, normoxic CM, or Dulbecco modified Eagle medium (DMEM, control). Cytokine antibody arrays and label-free quantitative proteomics analysis were used to compare the differences between hypoxic CM and normoxic CM. Injection of normoxic CM significantly reduced the infarct area and improved neurological recovery after stroke compared with administering DMEM. These outcomes may be associated with the attenuation of apoptosis and promotion of angiogenesis. Hypoxic preconditioning significantly enhanced these therapeutic effects. Fourteen proteins were significantly increased in hypoxic CM compared with normoxic CM as measured by cytokine arrays. The label-free quantitative proteomics analysis revealed 163 proteins that were differentially expressed between the two groups, including 107 upregulated proteins and 56 downregulated proteins. Collectively, our results demonstrate that hypoxic CM protected brain tissue from ischemic injury and promoted functional recovery after stroke in rats and that hypoxic CM may be the basis of a potential therapy for stroke patients.     

Expression of BjMT2, a metallothionein 2 from Brassica juncea, increases copper and cadmium tolerance in Escherichia coli and Arabidopsis thaliana, but inhibits root elongation in Arabidopsis thaliana seedlings

The protective function of a plant type-2 metallothionein was analysed after expression in Escherichia coli and in Arabidopsis thaliana seedlings. BjMT2 from Brassica juncea was expressed in E. coli as a TrxABjMT2 fusion protein. After affinity chromatography and cleavage from the TrxA domain, pure BjMT2 protein was obtained which strongly reacted with the thiol reagent monobromobimane. Escherichia coli cells expressing the TrxABjMT2 fusion were more tolerant to Cu2+ and Cd2+ exposure than control strains. Likewise, when BjMT2 cDNA was expressed in A. thaliana under the regulation of the 35S promoter, seedlings exhibited an increased tolerance against Cu2+ and Cd2+ based on shoot growth and chlorophyll content. Analysis of transiently transformed cells of A. thaliana and tobacco leaves by confocal laser scanning microscopy (CLSM) revealed exclusive cytosolic localization of a BjMT2::EGFP (enhanced green fluorescent protein) fusion protein in control and heavy metal-exposed plant cells. Remarkably, ectopic expression of BjMT2 reduced root growth in the absence of heavy metal exposure, whereas in the presence of 50 or 100 microM Cu2+ root growth in control and transgenic lines was identical. The results indicate that in A. thaliana, root and shoot development are differentially affected by ectopic expression of BjMT2.     

A fast empirical approach to binding free energy calculations based on protein interface information

Three useful variables from the interfaces of 20 protein-protein complexes were investigated. These variables are the side-chain accessible number (N(b)), the number of hydrophilic pairs (N(pair)) and buried a polar solvent accessible surface areas (DeltaDeltaASA(apol)). An empirical model based on the three variables was developed to describe the free energy of protein associations. As the results show, the side-chain accessible numbers characterize the loss of side-chain conformational entropy of protein interactions and the effective empirical function presented here has great capability for estimating the binding free energy. It was found that the variables of interface information capture most of the significant features of protein-protein association. Also, we applied the model based on the variables as a rescoring function to docking simulations and found that it has the potential to distinguish the 'true' binding mode. It is clear that the simple and empirical scale developed here is an attractive target function for calculating binding free energy for various biological processes to rational protein design.     

Endcaps for stabilizing short DNA duplexes

The syntheses of endcaps for covalently linking the 3' and 5' hydroxyl groups of blunt end double-stranded DNA are described. Endcap diols were converted into DMTr protected phosphoramidites and incorporated between nucleotides 4 and 5 of a self-complementary octamer. The stabilizing effect of the endcaps on duplex DNA was determined by Tm experiments on the self-complementary octamer.