Isolation and characterization of phenanthrene-degrading <Emphasis Type="Italic">Sphingomonas paucimobilis</Emphasis> strain ZX4

Phenanthrene-degrading bacterium strain ZX4 was isolated from an oil-contaminated soil, and identified as Sphingomonas paucimobilis based on 16S rDNA sequence, cellular fatty acid composition, mol% G + C and Biolog-GN tests. Besides phenanthrene, strain ZX4 could also utilize naphthalene, fluorene and other aromatic compounds. The growth on salicylic acid and catechol showed that the strain degraded phenanthrene via salicylate pathway, while the assay of catechol 2, 3-dioxygenase revealed catechol could be metabolized through meta-cleavage pathway. Three genes, including two of meta-cleavage operon genes and one of GST encoding gene were obtained. The order of genes arrangement was similar to S-type meta-pathway operons. The phylogenetic trees based on 16S rDNA sequence and meta-pathway gene both revealed that strain ZX4 is clustered with strains from genus Sphingomonas.     

Association between polymorphisms in the SLC27A1 gene and milk production traits in Chinese Holstein cattle

We assessed SLC27A1, a candidate gene for milk production traits in Chinese Holstein cattle. DNA was extracted from the blood of 48 top Chinese Holstein Cattle selected according to phenotypic character and mixed into DNA pool for SNP detection. We tested blood samples of these cattle for SNPs in exon 3 and the 3'-flanking region of the SLC27A1 gene by using polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and DNA sequencing. We found 2 polymorphic sites: 112T>C, a synonymous mutation, in exon 3 (SNP(1)), and 64G>A in the 3'-UTR (SNP(2)). We also determined the genotypes of 330 Chinese Holstein cattle by using PCR-restriction fragment length polymorphism (RFLP). We found 3 genotypes each at SNP(1) (TT, TC, and CC) and SNP(2) (GG, GA, and AA). The association among the different genotypes at these 2 sites and milk production traits was analyzed using a least-squares procedure. The results showed that cows with genotype CC had higher milk yields than those with genotype TC (0.01 < p < 0.05). No significant difference was detected among the 3 SNP(2) genotypes in terms of milk production traits. Our results provide evidence that the C allele have potential effects on milk yield trait.     

A novel magnetic biochar efficiently sorbs organic pollutants and phosphate

Biochar derived from agricultural biomass waste is increasingly recognized as a multifunctional material for agricultural and environmental applications. Three novel magnetic biochars (MOP250, MOP400, MOP700) were prepared by chemical co-precipitation of Fe³⁺/Fe²⁺ on orange peel powder and subsequently pyrolyzing under different temperatures (250, 400 and 700 °C), which resulted in iron oxide magnetite formation and biochar preparation in one-step. The MOP400 was comprised of nano-size magnetite particles and amorphous biochar, and thus exhibited hybrid sorption capability to efficiently remove organic pollutants and phosphate from water. For organic pollutants, MOP400 demonstrated the highest sorption capability, and even much larger than the companion non-magnetic biochar (OP400). For phosphate, magnetic biochars, especially MOP250, demonstrated much higher sorption capability than the companion non-magnetic biochars. No significantly competitive effect between organic pollutant and phosphate was observed. These suggest that the magnetic biochar is a potential sorbent to remove organic contaminants and phosphate simultaneously from wastewater.     

The Protective Mechanism for the Blood–Brain Barrier Induced by Aminoguanidine in Surgical Brain Injury in Rats

This study was performed to investigate the mechanism of blood–brain barrier (BBB) permeability change, which was induced by aminoguanidine (AG) after surgical brain injury (SBI) in rats. Compared to control group, AG (150 mg/kg, i.p.) significantly reduced Evans blue extravasation into brain tissue at 24 h after surgical resection, it also induced a 32% decrease of malondialdehyde (MDA) values and a 1.1-fold increase of the glutathione (GSH) levels at 12 h after injury. The expression of inducible nitric oxide synthase (iNOS) reached the peak value at 24 h after SBI, which was significantly attenuated after AG treatment. In addition, ZO-1 protein was up-regulated by AG (150 mg/kg) treatment at 24 h after SBI. Our results indicated that AG could protect the BBB after SBI, which could be correlated with antioxidative property, the down-regulation of iNOS and up-regulation of tight junction protein expression.     

Antifungal activity and mechanism of fengycin in the presence and absence of commercial surfactin against Rhizopus stolonifer

The antifungal activity and mechanism of fengycin in the presence and absence of commercial surfactin against Rhizopus stolonifer were investigated. The MIC (minimal inhibitory concentration) of fengycin without commercial surfactin added was 0.4 mg/ml while the MIC of fengycin with commercial surfactin added was 2.0 mg/ml. Fengycin acted on cell membrane and cellular organs and inhibited DNA synthesis. The antifungal effect of fengycin was reduced after commercial surfactin was added. All these results suggest that the fungal cell membrane may be the primary target of fengycin action and commercial surfactin may reduce the antifungal activity of fengycin.     

Discovery of new thienopyrimidine derivatives as potent and orally efficacious phosphoinositide 3-kinase inhibitors

A series of new thienopyrimidine derivatives has been discovered as potent PI3K inhibitors. The systematic SAR studies for these analogues are described. Among them, 8a and 9a exhibit nanomolar enzymatic potencies and sub-micromolar cellular anti-proliferative activities. 8a displays favorable pharmacokinetic profiles, while 9a easily undergoes deacetylation to yield a major metabolite 8a. Furthermore, 8a and 9a potently inhibit tumor growth in a dose-dependent manner in the NCI-H460 xenograft model with an acceptable safety profile.     

A role for the non‐receptor tyrosine kinase ACK1 in TNF‐alpha‐mediated apoptosis and proliferation in human intestinal epithelial caco‐2 cells

The roles of tumor necrosis factor alpha (TNF‐alpha) and its mediators in cellular processes related to intestinal diseases remain elusive. In this study, we aimed to determine the biological role of activated Cdc42‐associated kinase 1 (ACK1) in TNF‐alpha‐mediated apoptosis and proliferation in Caco‐2 cells. ACK1 expression was knocked down using ACK1‐specific siRNAs, and ACK1 activity was disrupted using a small molecule ACK1 inhibitor. The Terminal deoxynucleotidyl transferase biotin‐dUTP Nick End Labeling (TUNEL) and the BrdU incorporation assays were used to measure apoptosis and cell proliferation, respectively. ACK1‐specific siRNA and the pharmacological ACK1 inhibitor significantly abrogated the TNF‐alpha‐mediated anti‐apoptotic effects and proliferation of Caco‐2 cells. Interestingly, TNF‐alpha activated ACK1 at tyrosine 284 (Tyr284), and the ErbB family of proteins was implicated in ACK1 activation in Caco‐2 cells. ACK1‐Tyr284 was required for protein kinase B (AKT) activation, and ACK1 signaling was mediated through recruiting and phosphorylating the down‐stream adaptor protein AKT, which likely promoted cell proliferation in response to TNF‐alpha. Moreover, ACK1 activated AKT and Src enhanced nuclear factor‐кB (NF‐кB) activity, suggesting a correlation between NF‐кB signaling and TNF‐alpha‐mediated apoptosis in Caco‐2 cells. Our results demonstrate that ACK1 plays an important role in modulating TNF‐alpha‐induced aberrant cell proliferation and apoptosis, mediated in part by ACK1 activation. ACK1 and its down‐stream effectors may hold promise as therapeutic targets in the prevention and treatment of gastrointestinal cancers, in particular, those induced by chronic intestinal inflammation.