Stem Cell Transplantation Increases Antioxidant Effects in Diabetic Mice

Intra bone marrow-bone marrow transplantation (IBM- BMT) + thymus transplantation (TT) has been shown to reduce the incidence of graft versus host disease (GVHD) and restore donor-derived T cell function. In addition, an increase in insulin sensitivity occurred in db/db mice after IBM-BMT+TT treatment. Heme oxygenase (HO)-1 is a stress inducible enzyme which exert antioxidant, antiapoptotic, and immune-modulating properties. We examined whether IBM-BMT+TT could modulate the expression of HO-1 in the kidneys of db/db mice. Six-week-old db/db mice with blood glucose levels higher than 250 mg/dl were treated with IBM-BMT+TT. Six weeks later, the db/db mice showed decreased body weight, blood glucose levels and insulin, and increased plasma adiponectin levels. The upregulation of HO-1 was associated with significantly (p<0.05) increased levels of peNOS and pAKT, but decreased levels of iNOS in the kidneys of db/db mice. Plasma creatinine levels also decreased (p<0.05), and the expression of type IV collagen was improved. Thus IBM-BMT+TT unregulated the expression of HO-1, peNOS and pAKT, while decreasing iNOS levels in the kidney of db/db mice. This was associated with an improvement in renal function.     

Chemiluminescent immunoassay of thyroxine enhanced by microchip electrophoresis

A homogeneous chemiluminescent immunoassay of thyroxine (T4) enhanced by microchip electrophoresis separation has been developed. The method deployed the competitive immunoreaction of T4 and horseradish peroxidase (HRP)-labeled T4 (HRP-T4) with anti-T4 mouse monoclonal antibody (Ab). HRP-T4 and the HRP-T4-Ab complex were separated and quantified by using microchip electrophoresis (MCE) with chemiluminescence (CL) detection. Highly sensitive CL detection was achieved by means of HPR-catalyzed luminol-H₂O₂ reaction. Due to the effective MCE separation, the CL analytical signal was less prone to sample matrix interference. Under the selected assay conditions, the MCE separation was accomplished within 60 s. The linear range for T4 was 5-250 nM with a detection limit of 2.2 nM (signal/noise ratio = 3). The current method was successfully applied for the quantification of T4 in human serum samples. It was demonstrated that the current MCE-CL-enhanced competitive immunoassay was quick, sensitive, and highly selective. It may serve as a tool for clinical analysis of T4 to assist in the diagnosis of thyroid gland functions.     

Gene cloning and heterologous expression of a serine protease from Streptomyces fradiae var.k11

The gene sfp1, which encodes a predicted serine proteinase designated SFP1, was isolated by the screening of a gene library of the feather-degrading strain Streptomyces fradiae var.k11. The open reading frame of sfp1 encodes a protein of 454 amino acids with a calculated molecular mass of 46.19 kDa. Sequence analysis reveals that SFP1 possesses a typical pre-pro-mature organization that consists of a signal sequence, an N-terminal propeptide region, and a mature proteinase domain. The pre-enzyme of SFP1 was expressed in Escherichia coli and consequently purified. The 25.6 kDa fraction with protease activity separated by gel filtration chromatography indicated that the mature enzyme of SFP1 was formed by autolysis of the propeptide after its expression. The purified SFP1 is active under a broad range of pH and temperature. SFP1 has pH and temperature optima of pH 8.5 and 65 degrees C for its caseinolytic activity and pH 9 and 62 degrees C for its keratinolytic activity. SFP1 was sharply inhibited by the serine proteinase inhibitor phenylmethyl sulfonyl fluoride and exhibited a good stability to solvents, detergents, and salts. Comparison of the protease activity of SFP1 with other commercial proteases indicates that SFP1 has a considerable caseinolytic and keratinolytic activity as does proteinase K.     

成人降主动脉置换术中三种体外循环灌注技术的应用

目的总结分析成人降主动脉置换术中各种体外循环灌注的技术特点和管理方法。方法 2006年1月至2009年12月,共有60例患者行降主动脉置换手术。按体外循环灌注技术类型分为3组：左心转流组4例,股动静脉转流组37例,上下半身分别灌注组19例。三组预充均采用勃脉力A和胶体,常规加入白蛋白和激素,监测混合静脉氧饱和度和血细胞压积,积极应用超滤技术和自体血液回收技术。结果术中转流平稳,血流动力学稳定,监测指标均在正常范围,仅出现9例并发症（截瘫、偏瘫、谵妄、苏醒延迟、低氧血症）。结论成人降主动脉置换术中根据不同的手术方式,正确选择和熟练应用相应的灌注技术是决定手术成功的重要因素。     

Phylogeography of a northeast Asian spruce, Picea jezoensis, inferred from genetic variation observed in organelle DNA markers

Range-wide genetic variation of the widespread cold-temperate spruce Picea jezoensis was studied throughout northeast Asia using maternally inherited mitochondrial DNA and paternally inherited chloroplast DNA markers. This study assessed 33 natural populations including three varieties of the species in Japan, Russia, China, and South Korea. We depicted sharp suture zones in straits around Japan in the geographical distribution pattern of mitochondrial haplotypes (GST=0.901; NST=0.934). In contrast, we detected possible extensive pollen flow without seed flow across the straits around Japan during the past population history in the distribution pattern of chloroplast haplotypes (GST=0.233; NST=0.333). The analysis of isolation by distance of the species implied that by acting as a barrier for the movement of seeds and pollen, the sharp suture zones contributed considerably to the level of genetic differentiation between populations. Constructed networks of mitochondrial haplotypes allowed inference of the phylogeographical history of the species. We deduced that the disjunction with Kamchatka populations reflects range expansion and contraction to the north of the current distribution. Within Japan, we detected phylogeographically different types of P. jezoensis between Hokkaido and Honshu islands; P. jezoensis in Honshu Island may have colonized this region from the Asian continent via the Korean peninsula and the species in Hokkaido Island is likely to have spread from the Asian continent via Sakhalin through land bridges. Japanese endemism of mitochondrial haplotypes in Hokkaido and Honshu islands might have been promoted by separation of these islands from each other and from the Asian continent by the straits during the late Quaternary.     

Molecular Population Genetics of Rice Domestication

Domestication is a selection process that genetically modifies species to meet human needs. A most intriguing feature of domestication is the extreme phenotypic diversification among breeds. What could be the ultimate source of such genetic variations? Another notable outcome of artificial selection is the reduction in the fitness of domesticated species when they live in the wild without human assistance. The complete sequences of the two subspecies of rice cultivars provide an opportunity to address these questions. Between the two subspecies, we found much higher rates of non‐synonymous (N) than synonymous (S) substitutions and the N/S ratios are higher between cultivars than between wild species. Most interestingly, substitutions of highly dissimilar amino acids that are deleterious and uncommon between natural species are disproportionately common between the two subspecies of rice. We suggest strong selection in the absence of effective recombination may be the driving force, which we called the domestication‐associated Hill‐Robertson effect. These hitchhiking mutations may contribute to some fitness reduction in cultivars. Comparisons of the two genomes also reveal the existence of highly divergent regions in the genomes. Haplotypes in these regions often form highly polymorphic linkage blocks that are much older than speciation between wild species. Genes from such regions could contribute to the differences between indica and japonica and are likely to be involved in the diversifying selection under domestication. Their existence suggests that the amount of genetic variation within the single progenitor species Oryza rufipogon may be insufficient to account for the variation among rice cultivars, which may come from a more inclusive gene pool comprising most of the A‐genome wild species. Genes from the highly polymorphic regions also provide strong support for the independent domestication of the two subspecies. The genomic variation in rice has revealing implications for studying the genetic basis of indica‐japonica differentiation under rice domestication and subsequent improvement.     

The amyloid beta peptide (Abeta(1-40)) is thermodynamically soluble at physiological concentrations

Precipitation of the 39-43-residue amyloid beta peptide (Abeta) is a crucial factor in Alzheimer's disease (AD). In normal as well as in AD-afflicted brain, the Abeta concentration is estimated to be a few nanomolar. Here we show that Abeta(1-40) precipitates in vitro only if the dissolved concentration is >14 microM. Using fluorescence correlation spectroscopy, we further show that the precipitation is complete in 1 day, after which the size distribution of Abeta monomer/oligomers in the solution phase becomes stationary in time and independent of the starting Abeta concentration. Mass spectra confirm that both the solution phase and the coexisting precipitate contain chemically identical Abeta molecules. Incubation at 68 degrees C for 1 h reduces the solubility by <12%. Together, these results show that the thermodynamic saturation concentration (C(sat)) of Abeta(1-40) in phosphate-buffered saline (PBS) at pH 7.4 has a well-defined lower limit of 15.5 +/- 1 microM. Divalent metal ions (believed to play a role in AD) at near-saturation concentrations in PBS reduce C(sat) only marginally (2 mM Mg(2+) by 6%, 2.5 microM Ca(2+) by 7%, and 4 microM Zn(2+) by 11%). Given that no precipitation is possible at concentrations below C(sat), we infer that coprecipitant(s), and not properties of Abeta(1-40) alone, are key factors in the in vivo aggregation of Abeta.     

Attenuation of leukocyte-endothelium interaction by antioxidant enzymes

This report assessed the effect of overexpressing Cu,Zn superoxide dismutase (SOD) and/or catalase on the interaction of mononuclear cells (MNCs) and endothelial cells (ECs). ECs were obtained from the aorta of wild-type mice and transgenic mice overexpressing Cu,ZnSOD and/or catalase. MNCs were obtained from wild-type mice. Treatment of wild-type ECs with CuSO4-oxidized low-density lipoprotein (oxLDL) significantly elevated the expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and increased the adherence of MNCs. Overexpression of Cu,ZnSOD and/or catalase in ECs attenuated the adherence of MNCs and the expression of cell adhesion molecules induced by oxLDL. For example, ECs overexpressing Cu,ZnSOD and/or catalase showed significantly less expression of VCAM-1 and ICAM-1 and less number of adherent MNCs than wild-type ECs. Moreover, ECs overexpressing Cu,ZnSOD and catalase in combination showed significantly less expression of VCAM-1 and ICAM-1 and less number of adherent MNCs than those overexpressing either Cu,ZnSOD or catalase alone. These results suggest that combinational overexpression of Cu,ZnSOD and catalase can reduce the expression of cell adhesion molecules and inhibit the adherence of leukocyte to ECs more efficiently than overexpression of Cu,ZnSOD or catalase alone.