Evaluating the impact of microorganisms in the iron plaque and rhizosphere soils of Spartina alterniflora and Suaeda salsa on the migration of arsenic in a coastal tidal flat wetland in China.

The microorganism in rhizosphere systems has the potential to regulate the migration of arsenic (As) in coastal tidal flat wetlands. This study investigates the microbial community in the iron plaque and rhizosphere soils of Spartina alterniflora (S. alterniflora) and Suaeda salsa (S. salsa), as two common coastal tidal flat wetland plants in China, and determines the impact of the As and Fe redox bacteria on As mobility using field sampling and 16S rDNA high-throughput sequencing. The results indicated that As bound to crystalline Fe in the Fe plaque of S. salsa in high tidal flat. In the Fe plaque, there was a decrease in the presence of Fe redox bacteria, while the presence of As redox bacteria increased. Thus, the formation of Fe plaque proved advantageous in promoting the growth of As redox bacteria, thereby aiding in the mobility of As from rhizosphere soils to the Fe plaque. As content in the Fe plaque and rhizosphere soils of S. alterniflora was found to be higher than that of S. salsa. In the Fe plaque, As/Fe-reducing bacteria in S. alterniflora, and As/Fe-oxidizing bacteria in S. salsa significantly affected the distribution of As in rhizosphere systems. S. alterniflora has the potential to be utilized for wetland remediation purposes.

Interspecies introgressive hybridization in spiny frogs Quasipaa (Family Dicroglossidae) revealed by analyses on multiple mitochondrial and nuclear genes.

Introgression may lead to discordant patterns of variation among loci and traits. For example, previous phylogeographic studies on the genus Quasipaa detected signs of genetic introgression from genetically and morphologically divergent Quasipaa shini or Quasipaa spinosa. In this study, we used mitochondrial and nuclear DNA sequence data to verify the widespread introgressive hybridization in the closely related species of the genus Quasipaa, evaluate the level of genetic diversity, and reveal the formation mechanism of introgressive hybridization. In Longsheng, Guangxi Province, signs of asymmetrical nuclear introgression were detected between Quasipaa boulengeri and Q. shini. Unidirectional mitochondrial introgression was revealed from Q. spinosa to Q. shini. By contrast, bidirectional mitochondrial gene introgression was detected between Q. spinosa and Q. shini in Lushan, Jiangxi Province. Our study also detected ancient hybridizations between a female Q. spinosa and a male Q. jiulongensis in Zhejiang Province. Analyses on mitochondrial and nuclear genes verified three candidate cryptic species in Q. spinosa, and a cryptic species may also exist in Q. boulengeri. However, no evidence of introgressive hybridization was found between Q. spinosa and Q. boulengeri. Quasipaa exilispinosa from all the sampling localities appeared to be deeply divergent from other communities. Our results suggest widespread introgressive hybridization in closely related species of Quasipaa and provide a fundamental basis for illumination of the forming mechanism of introgressive hybridization, classification of species, and biodiversity assessment in Quasipaa.

The advertisement calls of Quasipaa shini (Ahl, 1930) (Anura: Dicroglossidae).

The genus Quasipaa (Family Dicroglossidae) is currently composed of 11 species distributed in China and Southeast Asia: Quasipaa acanthophora (Dubois & Ohler 2009), Q. boulengeri (Günther 1889), Q. courtoisi (Angel 1922), Q. delacouri (Angel 1928), Q. exilispinosa (Liu & Hu, 1975), Q. fasciculispina (Inger 1970), Q. jiulongensis (Huang & Liu, 1985), Q. shini (Ahl 1930), Q. spinosa (David 1875), Q. verrucospinosa (Bourret 1937), Q. yei (Chen, Qu & Jiang 2002) (Frost 2016). These species are morphologically similar, and their taxonomy is subject to controversy (Che et al. 2009). Analyses of nuclear and mitochondrial genes suggest the genus likely encompass additional cryptic species (Ye et al. 2013). Bioacoustics has contributed to studies on the taxonomy of the genus (Ye et al. 2013; Shen et al. 2015), however, to date, only the advertisement calls of Q. spinosa are known (Yu & Zheng 2009; Chen et al. 2012; Shen et al. 2015). Here, we describe the advertisement calls of Q. shini, which inhabits streams in the southern part of central China(Guizhou, Hunan, Guangxi and Jiangxi) and is characterized by the presence of keratinized skin spines on the lateral surfaces of the body.

Different ionic conditions prompt NHE2 and NHE3 translocation to the plasma membrane.

We tested whether NHE3 and NHE2 Na(+)/H(+) exchanger isoforms were recruited to the plasma membrane (PM) in response to changes in ion homeostasis. NHE2-CFP or NHE3-CFP fusion proteins were functional Na(+)/H(+) exchangers when transiently expressed in NHE-deficient PS120 fibroblasts. Confocal morphometry of cells whose PM was labeled with FM4-64 measured the fractional amount of fusion protein at the cell surface. In resting cells, 10-20% of CFP fluorescence was at PM and stable over time. A protocol commonly used to activate the Na(+)/H(+) exchange function (NH(4)-prepulse acid load sustained in Na(+)-free medium), increased PM percentages of PM NHE3-CFP and NHE2-CFP. Separation of cellular acidification from Na(+) removal revealed that only NHE3-CFP translocated when medium Na(+) was removed, and only NHE2-CFP translocated when the cell was acidified. NHE2/NHE3 chimeric proteins demonstrate that the Na(+)-removal response element resides predominantly in the NHE3 cytoplasmic tail and is distinct from the acidification response sequence of NHE2.

[Plasma glutathione of patients with coronary heart disease measured by fluorospectrophotometer].

The standard samples of reduction form glutathione (GSH) and oxidization form glutathione (GSSG) were scanned with full-wavelength range to determine the excitation wavelength lambda(ex) 334.4 nm, the emission wavelength lambda(em) 424 nm, and the spectral bandwidth 5 nm respectively. Phosphate buffer saline (PBS) of pH 8. 3 served as buffer solution. GSH was incubated for 30 min with 100 microL o-phthaldehyde (OPA) of 10 mmol x L(-1) methyl alcohol solution for derivatization, and then fluorescence intensities were measured. With standard glutathione concentration being independent variable and fluorescence intensity being dependent variable, the linear equations for GSH and GSSG were deduced: Y(GSH) = 6.9 + 8.6X (r2 = 0.994) and Y(GSSG) = 6.2 + 17.2X (r2 = 0.999). Standard curves were done hereby. The plasma glutathione of three groups was then measured, and GSH/ GSSG redox potential was calculated according to Nernst equation. The results indicated that, from normal control group to prophase coronary heart disease group, then to coronary heart disease group, the GSH and GSH/GSSG ratio gradually reduced, GSSG and GSH/GSSG redox potential gradually increased (more positive) (all P < 0.05), and the redox potential shifted to oxidization direction along with the development of coronary heart disease. This fluorospectrophotometry method showed simple operation, and fine precision and accuracy.

[Effects of xuezhikang capsules on vascular endothelial function and redox status in patients with coronary heart disease].

OBJECTIVE: To explore the effects of Xuezhikang Capsules (ZXKC) and probucol on blood lipids, vascular endothelial functions and redox status in patients with coronary heart disease. METHODS: One hundred and twelve patients with coronary heart disease were randomly divided into XZKC-treated group and probucol-treated group, 56 in each. Before and after 8-week treatment, the blood levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), nitric oxide (NO), endothelin-1 (ET-1), reduced glutathione (GSH) and oxidized glutathione (GSSG) were all measured in both groups. The GSH/GSSG redox potential (Eh) was calculated according to the Nernst equation. RESULTS: In the XZKC-treated group, the blood levels of TC, LDL-C and TG were significantly decreased after 8-week treatment as compared with those before treatment. The blood levels of TC and LDL-C were also significantly decreased in the probucol-treated group as compared with those before treatment. In the XZKC-treated group, the blood levels of ET-1 and GSSG and the GSH/GSSG Eh after treatment were all significantly lower than those before treatment, whereas the blood levels of GSH and NO, the NO/ET-1 ratio, and the GSH/GSSG ratio after treatment were all significantly higher than those before treatment. CONCLUSION: The XZKC or probucol treatment can yield a significant decrease in blood lipids in patients with coronary heart disease. Furthermore, XZKC exerts effective protection on vascular endothelial function, and can make GSH/GSSG redox status shift towards deoxidation.