Impaired arachidonic acid-mediated dilation of small mesenteric arteries in Zucker diabetic fatty rats

Arachidonic acid (AA) is a precursor of important vasoactive metabolites, but the role of AA-mediated vasodilation in Type 2 diabetes is not known. Using Zucker diabetic fatty (ZDF) rats, we examined the effects of AA in small mesenteric arteries preconstricted with endothelin. In ZDF rat mesenteric arteries, 1 microM AA produced only one-third the amount of dilation as in vessels from lean control animals. In lean control rats, the effect of AA was significantly and predominantly inhibited by the lipoxygenase inhibitors baicalein and cinnamyl-3,4-dihydroxy-cyanocinnamate (CDC). However, baicalein and CDC had no effect on AA-mediated dilation in ZDF rat mesenteric arteries. The major [3H]AA metabolite produced by isolated mesenteric arteries in both lean and ZDF rats was 12-hydroxyeicosatetraenoic acid (12-HETE), but the amount of [3H]12-HETE produced by ZDF rat vessels was only 36% of that of control vessels. In addition, 12-HETE produced similar amounts of dilation in lean and ZDF rat mesenteric arteries. Immunoblot analysis showed an 81% reduction in 12-lipoxygenase protein in ZDF rat mesenteric arteries. Immunofluorescence labeling showed strong nitrotyrosine signals in ZDF rat mesenteric arteries that colocalized with 12-lipoxygenase in endothelium, and 12-lipoxygenase coprecipitation with anti-nitrotyrosine antibodies was enhanced in ZDF rat vessels. We conclude that AA-mediated relaxation in ZDF rat small mesenteric arteries is impaired due to reduced 12-lipoxygenase protein and activity. Increased oxidative stress and nitration of 12-lipoxygenase may underlie the impairment of AA-mediated relaxation in small mesenteric arteries of diabetic rats.     

Suppression of phospholipase Dalpha1 induces freezing tolerance in Arabidopsis: response of cold-responsive genes and osmolyte accumulation

Phospholipase D (PLD; EC 3.1.4.4) plays an important role in membrane lipid hydrolysis and in mediation of plant responses to a wide range of stresses. PLDalpha1 abrogation through antisense suppression in Arabidopsis thaliana resulted in a significant increase in freezing tolerance of both non-acclimated and cold-acclimated plants. Although non-acclimated PLDalpha1-deficient plants did not show the activation of cold-responsive C-repeat/dehydration-responsive element binding factors (CBFs) and their target genes (COR47 and COR78), they did accumulate osmolytes to much higher levels than did the non-acclimated wild-type plants. However, a stronger expression of COR47 and COR78 in response to cold acclimation and to especially freezing was observed in PLDalpha1-deficient plants. Furthermore, a slower activation of CBF1 was observed in response to cold acclimation in these plants compared to the wild-type plants. Typically, cold acclimation resulted in a higher accumulation of osmolytes in PLDalpha1-deficient plants than in wild-type plants. Inhibition of PLD activity by using lysophosphatidylethanolamine (LPE) also increased freezing tolerance of Arabidopsis, albeit to a lesser extent than did the PLD antisense suppression. Exogenous LPE induced expression of COR15a and COR47 in the absence of cold stimulus. These results suggest that PLDalpha1 plays a key role in freezing tolerance of Arabidopsis by modulating the cold-responsive genes and accumulation of osmolytes.     

Arabidopsis irregular xylem8 and irregular xylem9: implications for the complexity of glucuronoxylan biosynthesis

Mutations of Arabidopsis thaliana IRREGULAR XYLEM8 (IRX8) and IRX9 were previously shown to cause a collapsed xylem phenotype and decreases in xylose and cellulose in cell walls. In this study, we characterized IRX8 and IRX9 and performed chemical and structural analyses of glucuronoxylan (GX) from irx8 and irx9 plants. IRX8 and IRX9 are expressed specifically in cells undergoing secondary wall thickening, and their encoded proteins are targeted to the Golgi, where GX is synthesized. 1H-NMR spectroscopy showed that the reducing end of Arabidopsis GX contains the glycosyl sequence 4-beta-D-Xylp-(1-->4)-beta-D-Xylp-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-D-GalpA-(1-->4)-D-Xylp, which was previously identified in birch (Betula verrucosa) and spruce (Picea abies) GX. This indicates that the reducing end structure of GXs is evolutionarily conserved in woody and herbaceous plants. This sequence is more abundant in irx9 GX than in the wild type, whereas irx8 and fragile fiber8 (fra8) plants are nearly devoid of it. The number of GX chains increased and the GX chain length decreased in irx9 plants. Conversely, the number of GX chains decreased and the chain length heterodispersity increased in irx8 and fra8 plants. Our results suggest that IRX9 is required for normal GX elongation and indicate roles for IRX8 and FRA8 in the synthesis of the glycosyl sequence at the GX reducing end.     

CRISPR Primer Designer:Design primers for knockout and chromosome imaging CRISPR-Cas system

The clustered regularly interspaced short palin-dromic repeats (CRISPR)-associated system enables biologists to edit genomes precisely and provides a powerful tool for perturbing endogenous gene regula...     

Assay for Laccase activity by microcalorimetry: laccase was extracted from china lacquer of Rhus vernicifera

The reactions between Laccase (extracted from China lacquer of Rhus vernicifera) and various substrates (3,4-Dihydroxybenzaldehyde, Guaiacol, Pyrogallol, Gallic acid) have been studied using LKB-2107 batch microcalorimetry system. Based on calorimetry, a new method has been proposed. Laccase activity and the Michaelis constant K(m) have been determined simultaneously by this method. The method is simple, sample-saving, and valid for a wider range of substrate concentrations. Furthermore, it can be extended for assaying other enzymes catalyzing reactions using this method.     

Prevalence of Hypertension in Rural Areas of China: A Meta-Analysis of Published Studies

Background

Hypertension is one of the leading causes of disease burden across the world. In China, the latest nationwide survey of prevalence of hypertension was ten year ago, and data in rural areas is little known. More information about hypertension prevalence could help to improve overall antihypertensive health care. We aimed to estimate the pooled prevalence of hypertension in rural areas of China.

Methods

Comprehensive electronic searches of PubMed, Web of Knowledge, Chinese Web of Knowledge, Wangfang, Weipu and SinoMed databases were conducted to identify any study in each database published from January 1, 2004 to December 31, 2013, reporting the prevalence of hypertension in Chinese rural areas. Prevalence estimates were stratified by age, area, sex, publication year, and sample size. All statistical calculations were made using the Stata Version 11.0 (College Station, Texas) and Statsdirect Version 2.7.9.

Results

We identified 124 studies with a total population of 3,735,534 in the present meta-analysis. Among people aged 18 years old in Chinese rural areas, the summarized prevalence is 22.81% (19.41%–26.41%). Subgroup analysis shows the following results: for male 24.46% (21.19%–27.89%, for female 22.17% (18.25%–26.35%). For 2004–2006: 18.94% (14.41%–23.94%), for 2007–2009, 21.24% (15.98%–27.01%) for 2010–2013: 26.68%, (20.79%–33.02%). For Northern region 25.76% (22.36%–29.32%), for Southern region 19.30%, (15.48%–24.08%).

Conclusions

The last decade witnessed the growth in prevalence of hypertension in rural areas of China compared with the fourth national investigation, which has climbed the same level as the urban area. Guidelines for screening and treatment of hypertension in rural areas need to be given enough attention.     

Folacin C60 derivative exerts a protective activity against oxidative stress-induced apoptosis in rat pheochromocytoma cells

In the present study, we describe the synthesis and characterization of a novel folacin C₆₀ derivative. The compound was analyzed by FT-IR, ¹H NMR, ¹³C NMR, LC–MS and elemental analysis. This water soluble fullerene derivative was able to scavenge both superoxide and hydroxyl radical with biocompatibility. Rat pheochromocytoma (PC12) cells treated with hydrogen peroxide underwent cytotoxicity and apoptotic death determined by MTT assay and flow cytometry analysis. As a novel derivative of C₆₀, the folacin C₆₀ derivative self-assembled to form spherical aggregates in H₂O. Because the compound was amphiphilic, it could penetrate the cell membrane and play its distinguished role in protecting PC12 cells against hydrogen peroxide-induced cytotoxicity. The results suggest that folacin C₆₀ derivative has the potential to prevent oxidative stress-induced cell death without evident toxicity.     

Murine cytomegalovirus with a transposon insertional mutation at open reading frame m155 is deficient in growth and virulence in mice

A pool of murine cytomegalovirus (MCMV) mutants was previously generated by using a Tn3-based transposon mutagenesis approach (X. Zhan, M. Lee, J. Xiao, and F. Liu, J. Virol. 74:7411-7421, 2000). In this study, one of the MCMV mutants, Rvm155, which contained the transposon insertion in open reading frame m155, was characterized in vitro for its replication in tissue culture and in vivo for its growth and virulence in immunodeficient SCID mice. Compared to the wild-type strain and a rescued virus that restored the m155 region, the mutant is significantly deficient in growth in many organs of the infected animals. At 21 days postinfection the titers of Rvm155 in the salivary glands, lungs, spleens, livers, and kidneys of the intraperitoneally infected SCID mice were lower than the titers of the wild-type virus and the rescued virus by 50-, 1,000-, 500-, 100-, and 500-fold, respectively. Moreover, the viral mutant was attenuated in killing the SCID mice, as none of the SCID mice that were intraperitoneally infected with Rvm155 died until 38 days postinfection while all the animals infected with the wild-type and rescued viruses died at 27 days postinfection. Our results provide the first direct evidence that a disruption of m155 expression leads to attenuation of viral virulence and growth in animals. Moreover, these results suggest that m155 is a viral determinant for optimal MCMV growth and virulence in vivo.     

Nickel(II) and cobalt(II) complexes of hydroxyl-substituted triazamacrocyclic ligand as potential antitumor agents

The stability constants for the formation of nickel(II) and cobalt(II) complexes of the ligand [1,4,7]triazecan-9-ol (L) were presented. Antitumor activity of two complexes was reported. Nuclei of [NiL]-stimulated BEL-7402 cells clearly exhibited condensation and break down into chromatin clumps typical of apoptosis. Also it exhibited perturbation effects to cell cycle, and optimal induction of apoptosis was found by Flow-Cytometric analysis. But CoL complex did not exhibit introduction effects to BEL-7402 cells apoptosis; and could not perturb cell cycle. NiL and CuL complexes could cleave supercoiled DNA (pBR 322 DNA) to nicked and linear DNA, and DNA of cells treated with NiL or CuL complex was obviously damaged; while CoL complex only could cleave supercoiled DNA (pBR 322 DNA) to nicked DNA, and DNA of cells treated with CoL complex had no significant difference with control.