Sphingomonas oleivorans sp. nov., isolated from oil-contaminated soil.

Strain FW-11T was isolated from oil-contaminated soil from Panjin in Liaoning, China. It was a Gram-stain-negative, aerobic and rod-shaped bacterium. The strain was confirmed to be a member of the genus Sphingomonas based on phylogenetic inference and phenotypic characteristics. The best growth of strain FW-11T occurred at 30 °C and pH 6.0-7.0. The strain was non-spore-forming, catalase-negative and oxidase-negative. The main polar lipids were sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and unidentified lipids. The cell-wall peptidoglycan of strain FW-11T included alanine, glycine, glutamic acid, aspartic acid and meso-diaminopimelate. The predominant isoprenoid quinones were ubiquinone Q-10 (93.2 %) and Q-9 (6.8 %). The fatty acid profile (>5 %) included C18 : 1ω6c (43.1 %), C16 : 0 (14.6 %), C17 : 1ω6c (14.0 %) and C14 : 0 2-OH (11.1 %). The most similar neighbours of FW-11T were Sphingomonas fennica K101T (97.4 %) and Sphingomonas haloaromaticamans A175T (97.0 %). The average nucleotide identity relatedness values between strain FW-11T and the two type strains (S. fennica K101T and S. haloaromaticamans A175T) were 73.2 and 75.3 %, respectively. The genome size of FW-11T was 3.8 Mbp, comprising 3735 predicted genes with a DNA G+C content of 64.0 mol%. Based on phenotypic, chemotaxonomic and phylogenetic data, strain FW-11T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas oleivorans sp. nov. is proposed. The type strain is FW-11T (=LMG 29274T=HAMBI 3659T).

[Advance on chemical compounds of Ainsliaea genus].

Plants in Ainsliaea genus, belongs to Compositae family, are traditional Chinese medicine and widely used in folk. These plants contain various types of chemical components, and main components are sesquiterpene lactone and its glycosides. In addition, there are triterpenoids, flavonoids, steroids, phenolic acid, long chain fatty acid and volatile oils. Recently, much attention has been payed to varlous research of A. fragrans. This paper reviewed and summarized the chemical components to provide the theoretical basis for the use of Ainsliaea.

[Hypoxia-responsive factor PHD2 and angiogenic diseases].

Prolyl-4-hydroxylase domain (PHDs) family is one of the most important regulatory factors in hypoxic stress. PHD2 plays a critical role in cells and tissues adaptation to the low oxygen environment. Its hydroxylation activity regulates the stability and transcriptional activity of the hypoxia-inducible factor 1 (HIF-1), which is the key factor in response to hypoxic stress. Subsequently, PHD2 acts as an important factor in oxygen homeostasis. Studies have shown that PHD2, through its regulation on HIF-1, plays an important role in the post-ischemic neovascularization. Furthermore, under hypoxic condition, PHD2 also regulates other pathways that positively regulate angiogenesis factors HIF-1 independently. Moreover, recently, several evidences have also shown that PHD2 also affects tumor growth and metastasis in a tumor microenvironment. Based on these facts, PHD2 have been considered as a potential therapeutic target both in treating ischemic diseases and tumors. Here, we review the molecular regulation mechanism of PHD2 and its physiological and pathological functions. We focus on the role of PHD2 in both therapeutic angiogenesis for ischemic disease and tumor angiogenesis, and the current progress in utilizing PHD2 as a therapeutic target.

Preparation of heparin-immobilized PVA and its adsorption for low-density lipoprotein from hyperlipemia plasma.

In this study, heparin was covalently coupled by glutaraldehyde to Poly(vinyl alcohol) [PVA] in solid-liquid two-phase reaction system by two-step synthesis method to prepare a LDL-selective adsorbent. The parameters (the material ratio, reaction time and dosage of catalyzer) were investigated to evaluate their effect upon the immobilized amount of heparin onto the surface of PVA, IR was used to verify the covalent immobilization result and the heparin-modified PVA was also undergone the evaluation of its adsorption capability for low-density lipoprotein from hyperlipemia plasma, and its hemocompatibility was preliminarily evaluated by platelet adhesion test. Results showed: (1) under optimized reaction conditions the highest immobilization amount of heparin onto PVA surface within the experiments of this study has been obtained; (2) the optimized reaction conditions were: (i) at the refluxing temperature 78 degrees C; (ii) the material ratio of "PVA(g): 50% glutaraldehyde (ml)" was about "1:3"; (iii) the reaction time was about 5 h; and (iv) the amount of catalyzer (concentrated HCL) was about 1% of the 50% glutaraldehyde; (3) within the experiments of this study the highest immobilization amount would be up to 25 microg heparin on the surface of per g PVA granules; (4) the heparin-modified PVA granules showed significant adsorption for LDL under faintly alkaline environment (pH=7.2-9.5) ; (5) The result of platelet adhesion test showed no platelet adhered to its surface. Therefore, immobilization of heparin onto the surface of a support is one approach to prepare a kind of LDL adsorbent for blood purification.

Fabrication of a PLGA-collagen peripheral nerve scaffold and investigation of its sustained release property in vitro.

This study deals with the fabrication of a peripheral nerve scaffold prepared with poly (lactic acid-co-glycolic acid) [PLGA] and acellularized pigskin collagen micro particles and the investigation of its sustained release property in vitro. We took bovine serum albumin [BSA] as model drug to investigate the sustained-release property of the scaffold in vitro. The results showed the scaffold could release BSA steadily with a rate of 6.6 ng/d (r=0.994) or so. In a 1-month test period, the accumulative release ratio of BSA from the scaffold was up to 43%, and the shape of the scaffold was still originally well kept. In addition, the scaffold outcome non-immunogenicity, good cell adhesion and biodegradability. The results indicated a scaffold constructed by this technique would be a potential implanting support with prolonged sustained release function, such as for the use of nerve scaffold.

Characteristics of PLGA-gelatin complex as potential artificial nerve scaffold.

The segmentation lesion of peripheral nerve will seriously impair the motion and sensation of the patients, and the satisfactory recovery of segmented peripheral nerve by autograft or allograft is still a great challenge posing to the neurosurgery. Apart from autograft for nerve repair, different allograft has been studying. In this study, a scaffold fabricated with polylactic acid-co-glycolic acid (PLGA) copolymer and gelatin was evaluated to be a potential artificial nerve scaffold in vitro. The effect of different mass ratio between PLGA and gelatin upon the characteristics of PLGA-gelatin scaffolds such as microstructure, mechanical property, degradation behavior in PBS, cell adhesion property were investigated. The results showed the homogeneity and mechanical property of the scaffolds became poor with the increase of gelatin, and the rate of max water-uptake and the mass loss of scaffolds increases with the increase of gelatin, and the cells could adhere to the scaffolds. Those indicated the scaffolds fabricated by the PLGA-gelatin complex had excellent biocompatibility, suitable mechanical property and sustained-release characteristics, which would meet the requirements for artificial nerve scaffold.

[Effect of overdose fluoride on the expression of enamelin in rat mandibular incisor].

OBJECTIVE: To observe the effect of overdose fluoride on the expression of enamelin in rat mandibular incisor. METHODS: Twenty Wistar rats were divided randomly into two groups. Animals were maintained in standard environment with free access to food and distilled water (control group) or water added with 100 mg/L F-(experimental group). The rats were killed in the eighth week. HE staining was used to observe the morphology of ameloblasts. Immunohistochemical staining was adopted to study the expressions of enamelin in rat incisor. RESULTS: The ameloblasts of the treated rat were arranged in multi-layer. The ameloblasts in group II were thinner than those in group I. The structure of enamel matrix was in disorder. The expressions of enamelin in ameloblasts and odontoblasts were obviously inhibited in group II (P < 0.01). CONCLUSION: The overdose fluoride inhibits the secretion of enamelin and leads to the abnormal development of enamel matrix.

[Effect of overdose fluoride on expression of bone sialoprotein in developing dental tissues of rats].

PURPOSE: To investigate the changes of bone sialoprotein (BSP) in developing dental tissues of rats exposed to fluoride. METHODS: Twenty rats were randomly divided into two groups, one was with distilled water (control group), the other was with distilled water treated by fluoride (experimental group). When the fluorosis model was established, the changes of the expression of BSP were investigated and compared between the two groups. HE staining was used to observe the morphology of the cell, and immunohistochemisty assay was used to determine the expression of BSP in rat incisor. Student's t test was used for statistical analysis. RESULTS: The ameloblasts had normal morphology and arranged orderly. Immunoreactivitis of BSP was present in matured ameloblasts, dentinoblasts, cementoblasts, and the matrix in the control group. But in the experimental group the ameloblasts arranged in multiple layers, the enamel matrix was confused and the expression of BSP was significantly lower than that of the control group. Statistical analysis showed significant differences between the two groups (P<0.01). CONCLUSION: Fluoride can inhibit the expression of BSP in developing dental tissues of rats, and then inhibit differentiation of the tooth epithelial cells and secretion of matrix. This is a probable intracellular mechanism of dental fluorosis.