Equilibrium studies on enantioselective liquid–liquid extraction of homophenylalanine enantiomers with metal-BINAP complexes

Enantioselective liquid–liquid extraction of homophenylalanine (Hph) enantiomers was investigated with metal-BINAP complexes as enantioselective extractants. The metal complexes were synthesized by the complexation of (s)-2,2′-Bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) with different central ions, among which, copper(I) complex allowed the separation of the Hph enantiomers with the highest operational selectivity. Efficiency of the extraction depends, often strongly, on a number of process variables, including types of organic solvents, pH of the aqueous phase, concentration of host and substrate, and temperature. In order to better understand the extraction process, equilibrium of the system were modeled by a homogeneous reaction model and an interfacial reaction model, respectively. Important parameters required by the modeling, such as complexation equilibrium constant and physical distribution coefficients were determined experimentally. When coupled with the parameters, extraction performance can be predicted by the models. Comparison between the experimental values and the model predictions indicates that the homogeneous reaction model can predict more accurately. By modeling and experiment, an optimal extraction condition concerning pH of 8 and host concentration of 2 mmol/L was obtained with high enantioselective (α) of 1.837 and performance factor (pf) of 0.086.     

Analysis of DYS19 and DYS287 polymorphisms in the Han population and three other ethnic groups of northeast China

The allelic distribution of the Y-chromosome specific microsatellite DYS19 in the Han population and in the Daur, Oroqen and Ewenki ethnic groups (Northeast China) was analyzed by PCR and denatured polyacrylamide gel electrophoresis. The allelic distribution in the Han population group is as follows: A = 2.90%, B = 26.09%, C = 26.09%, D = 29.98%, E = 15.94%. This allelic distribution differs statistically significant from that observed in the three other ethnic groups (p < 0.05). Furthermore the polymorphism of the Y-chromosome specific Alu insert sequence DYS287 was tested in these four groups. However, no Alu sequence insert was found.     

Genetic diversity and population history of the red panda (Ailurus fulgens) as inferred from mitochondrial DNA sequence variations

The red panda (Ailurus fulgens) is one of the flagship species in worldwide conservation and is of special interest in evolutionary studies due to its taxonomic uniqueness. We sequenced a 236-bp fragment of the mitochondrial D-loop region in a sample of 53 red pandas from two populations in southwestern China. Seventeen polymorphic sites were found, together with a total of 25 haplotypes, indicating a high level of genetic diversity in the red panda. However, no obvious genetic divergence was detected between the Sichuan and Yunnan populations. The consensus phylogenetic tree of the 25 haplotypes was starlike. The pairwise mismatch distribution fitted into a pattern of populations undergoing expansion. Furthermore, Fu's F(S) test of neutrality was significant for the total population (F(S) = -7.573), which also suggests a recent population expansion. Interestingly, the effective population size in the Sichuan population was both larger and more stable than that in the Yunnan population, implying a southward expansion from Sichuan to Yunnan.     

Loss of Core 1-derived O-Glycans Decreases Breast Cancer Development in Mice

Mucin-type core 1-derived O-glycans, one of the major types of O-glycans, are highly expressed in mammary gland epithelium. Abnormal O-glycans such as Tn antigen are found in over 90% of breast cancers; however, the in vivo role of these aberrant O-glycans in the etiology of breast cancer is unclear. We generated mice with mammary epithelial specific deletion of core 1-derived O-glycans. By crossing with two spontaneous mouse breast cancer models, we determined that loss of core 1-derived O-glycans delays the onset and progression of breast cancer development. Deficiency of core 1 O-glycosylation impaired the localization of Muc1, a major O-glycoprotein, on the apical surfaces of mammary epithelium. Signaling mediated by Muc1, which is critical for breast cancer development, was also defective in the absence of core 1 O-glycans. This study reveals an unexpected role of core 1-derived O-glycans in breast cancer development in mice.     

Relationship between gene expression of UDP-glucose pyrophosphorylase and agar yield in Gracilariopsis lemaneiformis (Rhodophyta)

UDP-glucose pyrophosphorylase (UGPase) is an enzyme involved in the biosynthesis of UDP-D-galactose, a subunit of agar in red seaweeds. The relationship between agar content and expression levels of the UGPase encoding gene (glugp) was studied in thalli under different treatment conditions using a quantitative real-time PCR-based method (qPCR). Moreover, this qPCR method for the measurement of glugp expression was also applied to commercial varieties of Gracilariopsis lemaneiformis, a red macroalga, in order to examine its reliability on material obtained from field cultivation. Both the agar content and glugp gene expression in G. lemaneiformis grown under low salinity (17?‰) conditions for 1 week showed a slight increase in comparison with the control group (33?‰ salinity, natural salinity of seawater), but the difference was not statistically significant (P?>?0.05). However, when the culture time was extended to 2 weeks, the increase in both the agar yield and glugp expression became significant (P?glugp expression (P?>?0.05). Our results suggest that glugp gene expression and agar content are highly positively correlated and that the measurement of glugp expression, using only a small amount of thalli material, may be an efficient approach to evaluate agar content. In addition, both the agar content and glugp expression in cultivars 981, 07-2, and ZC differed significantly from those of MT-18. The findings of this study suggest that UGPase may be involved in agar biosynthesis and indicate that glugp gene expression could be a fairly reliable molecular marker to reflect the agar content of strains during breeding and selection of G. lemaneiformis.     

Induction of Murine Macrophage M2 Polarization by Cigarette Smoke Extract via the JAK2/STAT3 Pathway

Cigarette smoking is a major pathogenic factor in lung cancer. Macrophages play an important role in host defense and adaptive immunity. These cells display diverse phenotypes for performing different functions. M2 type macrophages usually exhibit immunosuppressive and tumor-promoting characteristics. Although macrophage polarization toward the M2 phenotype has been observed in the lungs of cigarette smokers, the molecular basis of the process remains unclear. In this study, we evaluated the possible mechanisms for the polarization of mouse macrophages that are induced by cigarette smoking (CS) or cigarette smoke extract (CSE). The results showed that exposure to CSE suppressed the production of reactive oxygen species (ROS) and nitric oxide (NO) and down-regulated the phagocytic ability of Ana-1 cells. The CD163 expressions on the surface of macrophages from different sources were significantly increased in in vivo and in vitro studies. The M1 macrophage cytokines TNF-α, IL-12p40 and enzyme iNOS decreased in the culture supernatant, and their mRNA levels decreased depending on the time and concentration of CSE. In contrast, the M2 phenotype macrophage cytokines IL-10, IL-6, TGF-β1 and TGF-β2 were up-regulated. Moreover, phosphorylation of JAK2 and STAT3 was observed after the Ana-1 cells were treated with CSE. In addition, pretreating the Ana-1 cells with the STAT3 phosphorylation inhibitor WP1066 inhibited the CSE-induced CD163 expression, increased the mRNA level of IL-10 and significantly decreased the mRNA level of IL-12. In conclusion, we demonstrated that the M2 polarization of macrophages induced by CS could be mediated through JAK2/STAT3 pathway activation.