Flexible nano-liposomes-based transdermal hydrogel for targeted delivery of dexamethasone for rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that can lead to synovitis, cartilage destruction, and even joint damage. Dexamethasone (DEX) is a commonly used agent for RA therapy on inflammation manage. However, the traditional administering DEX is hampered by low efficiency and obvious adverse effects. Therefore, in order to efficiently deliver DEX to RA inflamed joints and overcome existing deficiencies, we developed transdermal formation dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel), validated their transdermal efficiency, evaluated its ability to target activated macrophages, and its anti-inflammatory effect. The DS-FLs/DEX exhibited excellent biocompatibility, sustainable drug release, and high uptake by lipopolysaccharide (LPS)-activated macrophages. Furthermore, the DS-FLs/DEX hydrogel showed desired skin permeation as compared with regular liposome hydrogel (DS-RLs/DEX hydrogel) due to its good deformability. In vivo, when used the AIA rats as RA model, the DS-FLs/DEX hydrogel can effectively penetrate and accumulate in inflamed joints, significantly improve joint swelling in RA rats, and reduce the destructive effect of RA on bone. Importantly, the expression of inflammatory cytokines in joints was inhibited and the system toxicity did not activate under DS-FLs/DEX hydrogel treatment. Overall, these data revealed that the dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel) can prove to be an excellent drug delivery vehicle against RA.

Inhibition of CDK1 attenuates neuronal apoptosis and autophagy and confers neuroprotection after chronic spinal cord injury in vivo.

Chronic spinal cord injury (CSCI) results from progressive compression of the spinal cord over time. A variety of factors cause CSCI, and its exact pathogenesis is unknown. Cyclin-dependent kinase 1 (CDK1) is closely related to the apoptosis pathway, but no CSCI-related studies on CDK1 have been conducted. In this study, the role of CDK1 in CSCI was explored in a rat model. The CSCI model was established by screw compression using the cervical anterior approach for twelve weeks. The neurological function of the rats was evaluated using the neurological severity scores (NSS) and motor evoked potentials (MEPs). Pathological changes in spinal cord tissue were observed by hematoxylin-eosin (HE) staining, and Nissl staining was performed to assess the survival of motor neurons in the anterior horn of the spinal cord. Changes in autophagy and apoptosis in anterior horn of spinal cord tissue were detected using transmission electron microscopy and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. The expression levels of glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor (IBA) and choline acetyltransferase (CHAT) in the anterior horn were determined using immunohistochemistry assays to investigate astrocytes, microglia and motor neurons, respectively, in the anterior horn. Western blot assays were used to detect the expression levels of CDK1, Bcl-2, Bax, Caspase 3, LC3 and Beclin1. Changes in the expression of CDK1, LC3 and Beclin1 were also observed using immunohistochemistry. The results indicated that CSCI resulted in neuronal injury and a decrease in the NSS. In the CSCI model group, anterior horn astrocytes and microglia were activated, and motor neurons were decreased. Neuronal apoptosis was promoted, and the number of autophagic vacuoles was elevated. Rats treated with the CDK1 shRNA lentivirus exhibited better NSS, more surviving motor neurons, and fewer apoptotic neurons than the model rats. The occurrence of autophagy and the expression of proapoptotic and autophagy-related proteins were lower in the CDK1 shRNA group than the model group. In conclusion, CDK1 downregulation suppressed the activation of anterior horn astrocytes and microglia, promoted motor neuron repair, and inhibited neurons apoptosis and autophagy to promote the recovery of motor function after spinal cord injury.

Visible light induced 3-position-selective addition of arylpropiolic acids with ethers via C(sp3)-H functionalization.

Although the 2-position-selective decarboxylative coupling or addition of arylpropiolic acids with cyclic ethers has been intensively investigated, selective functionalization of arylpropiolic acids at the 3-position is still a big challenge. Herein, an intriguing and mild method for visible light induced regioselective addition of arylpropiolic acids by attacking exclusively at the 3-position with cyclic/acyclic ethers was developed. A variety of 3,3-bis-substituted acrylic acids were successfully obtained in moderate to excellent yields. A plausible reaction mechanism involving an energy transfer induced radical addition in the presence of visible light and photocatalyst was proposed.

Long non-coding RNA TUG1 promotes cell progression in hepatocellular carcinoma via regulating miR-216b-5p/DLX2 axis.

BACKGROUND: Accumulating evidence indicates that the long noncoding RNA taurine upregulated gene 1(TUG1) plays a critical role in cancer progression and metastasis. However, the overall biological role and clinical significance of TUG1 in hepatocellular carcinoma (HCC) remain largely unknown. METHODS: The expressions of TUG1, microRNA-216b-5p and distal-less homeobox 2 (DLX2) were detected by Quantitative real-time polymerase chain reaction (qRT-PCR). The target relationships were predicted by StarBase v.2.0 or TargetScan and confirmed by dual-luciferase reporter assay. The cell growth, apoptosis, migration and invasion were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Flow cytometry and Transwell assays, respectively. All protein expression levels were detected by western blot. Tumor xenografts were implemented to explore the role of TUG1 in vivo. RESULTS: We found that there was a marked rise in TUG1 expression in HCC tissues and cells, and knockdown of TUG1 repressed the growth and metastasis and promoted apoptosis of HCC cells. In particular, TUG1 could act as a ceRNA, effectively becoming a sink for miR-216b-5p to fortify the expression of DLX2. Additionally, repression of TUG1 impared the progression of HCC cells by inhibiting DLX2 expression via sponging miR-216b-5p in vitro. More importantly, TUG1 knockdown inhibited HCC tumor growth in vivo through upregulating miR-216b-5p via inactivation of the DLX2. CONCLUSION: TUG1 interacting with miR-216b-5p contributed to proliferation, metastasis, tumorigenesis and retarded apoptosis by activation of DLX2 in HCC.

[Treatment of scapular fractures with lateral incision and bridge combined internal fixation system].

OBJECTIVE: To investigate the clinical results of scapula fractures with lateral incision combined with bridge internal fixation system. METHODS: From October 2012 to December 2016, 20 cases of scapular fractures were treated through the lateral incision combined with bridge fixation system, including 15 males and 5 females, with an average age of 31.6 years old(ranged, 21 to 52 years old). Fourteen cases were scapular body fracture, 10 were scapular neck fracture, 6 were scapular fracture, 1 was acromion fracture, 1 was coracoid fracture, 4 were the glenoid rim fracture, 3 were the glenoid fossa fracture. The operation time ranged from 4 to 15 d after injury with an average of 10 d. RESULTS: All 20 cases were followed up for 3 to 24 months with an average of 15 months. Wound infection occurred in 2 cases after operation, and was healed after wound debridement and change dressing; no osteomyelitis, iatrogenic nerve injury, breakage of internal fixation, fracture displacement, joint stiffness occurred. Callus growth was observed at the fracture site 3 months after operation, the fracture healing time was 4 to 7 months, fracture healing was good without delayed union or malunion. According to Hardegger shoulder score, the results were excellent in 12 cases, good in 6 cases, moderate in 2 cases. CONCLUSIONS: Lateral incision approach combined with bridge internal fixation system for scapula fractures has the advantages of easy operation, revealed clearly, and the incision can be arbitrary to extend on both sides, to provide favorable conditions for the reduction and fixation of fracture. Bridge combined internal fixation system has the advantages of flexible operation, reliable fixation strength, is a good choice for treatment of scapula fracture.

Effects of alisol B 23-acetate on ovarian cancer cells: G1 phase cell cycle arrest, apoptosis, migration and invasion inhibition.

BACKGROUND: Ovarian cancer is the first leading cause of death among gynecologic malignancies worldwide. Discovery of new chemotherapeutic drugs is still imperative for the improvement of the survival rate. PURPOSE: This study aims to investigate the anti-cancer potential of alisol B 23-acetate (AB23), a protostane-type triterpene isolated from the Alismatis Rhizoma, in the parental and paclitaxel-resistant ovarian cancer cells. METHODS: MTT assay was performed to evaluate cell viability after treatment with AB23, along with flow cytometry for apoptosis and cell cycle analysis. Western blotting was conducted to determine the relative protein level. Wound healing and transwell assays were performed to investigate the effect of AB23 on cell migration and invasion. RESULTS: AB23 obviously inhibited proliferation of the three ovarian cancer cell lines, down-regulated the protein levels of CDK4, CDK6, and cyclin D1, and blocked the cell cycle progressions in G1 phase. Meanwhile, AB23 induced accumulation of the sub-G1 phase in the three cell lines in a concentration dependent manner. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and the ratio of Bax/Bcl-2 were up-regulated after treatment with AB23. Further study showed that AB23 induced endoplasmic reticulum stress through IRE1 signaling pathway and silencing of IRE1α partially enhanced AB23-induced apoptosis. Wound healing and transwell assays showed that AB23 could also suppress the migration and invasion of HEY cells. Moreover, it down-regulated the protein levels of matrix metalloproteinases MMP-2 and MMP-9. CONCLUSION: AB23 possessed anti-proliferation, anti-migration and anti-invasion activities as a single agent on ovarian cancer cells.

[Effects of growth years of Paeonia lactiflora on bacterial community in rhizosphere soil and paeoniflorin content].

To explore the relationship between microecological environment and Paeonia lactiflora the effects of growth years of P. lactillora on rhizosphere bacterial communities were studied by PCR-DGGE and the paeoniflorin content determined by HPLC. Results showed that the soil pH increased with growing years of P. lactillora. In the fourth year, soil pH and enzyme activity reached the highest level, while organic matter content was the lowest. The bacterial diversity had a positive correlation with growing years varied from 3.38 to 3.61. Sequencing results demonstrated that Gammaproteobacteria, llphaproteobacteria, Actinobacteria, Acidobacte- ria and Firmicutes were predominant bacteria kinds in the soil of P. lactillora. Gammaproteobacteria was only detected in the bulk soil, while llphaproteobacteria, Acidobacteria G1l, Actinobacteria were only in the rhizosphere soil and the bacterial community among different growing years were similar except few species. HLPC results showed that paeoniflorin content was 3.26%, 3.30%, 3.36%, 3.41% separately from one to four-year-old P. lactiflora with an upward trend. The correlation analysis indicated that the paeoniflorin content had a positive correlation with soil pH and bacterial diversity, conversely, had a negative correlation with organic matter con- tent. During the growth years the rhizosphere bacterial diversity increased without changes of predominant bacteria and the paeoniflorin content increased without significant differences while its production increased significantly, which was different from the plants showing replanting diseases. This is in line with the farming practice choosing 4-year-old P. lactllora, but not the 1-3 year old one. In addition, the accumulation of paeoniflorin is closely related to soil pH, organic matter content and bacteria diversity, confirming that the geoherblism of P. lactiflora is closely related with microbial environment in the soil.

Enhanced water-soluble derivative of PC407 as a novel potential COX-2 inhibitor injectable formulation.

PC407 is an effective COX-2 inhibitor in non-steroidal anti-inflammatory drug development but the poor solubility limits their usefulness. The aim of the study was to prepare and evaluate 4-oxo-4-[4-(5-(naphthalen-2-yl)-3-(trifluoromethyl)-1H-pyrazol-1-yl)benzenesulfonamido]butyrate disodium, a derivative of PC407 with enhanced water solubility for injectable formulation. The prepared derivative displayed interesting high aqueous solubility (20.3 mg/mL, much superior to the parent compound PC407, 1.6 µg/mL) with confirmed in vivo analgesic activity. This derivative represents the profiles of prodrug and potential candidate of PC407 for the development of injectable COX-2 inhibitor due to extraordinary water solubility, low toxicity, and impressive analgesic activity.

De-acetyl-cinobufalactam monohydrate.

The title compound, C24H33NO4·H2O, the reaction product of de-acetyl-cinobufagin with ammonium acetate, consists of three cyclo-hexane rings (A, B and C), one five-membered ring (D), one six-membered lactone ring (E) and an epoxide ring (F). The stereochemistry of the ring junctures are A/B cis, B/C trans, C/D cis and D/F cis. Cyclo-hexane rings A, B and C have normal chair conformations. The five-membered ring D adopts an envelope conformation (with the C atom bearing the lactone ring as the flap) and the lactone ring E is planar. In the crystal, hy-droxy and water O-H⋯O and amine N-H⋯O hydrogen bonds involving carbonyl, hy-droxy and water O-atom acceptors link the mol-ecules into a three-dimensional network.

Synthesis of bufalin derivatives with inhibitory activity against prostate cancer cells.

Bufalin possesses a strong anti-cancer effect, but the cardiac toxicity targeting the Na(+), K(+)-ATPase limits its application. Here, two bufalin derivatives, bufadienolactam (1) and secobufalinamide (2), were synthesised by treating bufalin with ammonium acetate in dimethylformamide solution. Their structures were elucidated by extensive spectroscopic methods. The structure of compound 2 was further confirmed by single-crystal X-ray diffraction analysis. Compounds 1 and 2 expressed strong inhibitory activities against androgen-dependent prostate cancer cells (IC50 values about 10 µM), but only weak inhibition on Na(+), K(+)-ATPase (Ki about 70 µM), indicating that they might be potential anti-prostate cancer agents without severe cardiac toxicity.

A bufadienolide derived androgen receptor antagonist with inhibitory activities against prostate cancer cells.

Molecular docking studies have shown that Δ(8,14)-anhydrobufalin (1) exhibited more potent binding affinity on androgen receptor (AR) than Δ(14,15)-anhydrobufalin (2) and bufalin (3). To validate the docking results, compounds 1 and 2 were synthesized. The AR competitive binding assay indicated that the IC50 values of 1-3 were 1.9, >50 and >50µM (relative binding affinity), respectively, which confirmed that our theoretical binding mode was reliable and predictable. Furthermore, compound 1 was found to show more potent inhibitory activity against the androgen dependent LNCaP cancer cells than the androgen independent PC3 cancer cells, but exhibited less inhibition on the Na(+)/K(+) ATPase as compared with the parent compound 3. To the best of our knowledge, compound 1 represented the first AR antagonist derived from bufadienolide discovered through a series of combined approaches of molecular docking and actual experimental validation.

[Effect of different treatment on endophytic bacterial communities in continuous cropping of Chrysanthemum morifoliu].

To reveal the effect of rotation cropping and bacterial manure on the growth of Chrysanthemum morifolium and screen the beneficial endophytic, the diversity of endophytic and dominant genera of different treatment groups were analyzed. Four different treatments were continuous cropping, rotation, self-made organic fertilizer and commercially available fertilizer, respectively. Endophytic bacterial diversity and dominant genera in different organs were examined using Terminal Restriction Fragment Length Polymorphism (T-RFLP). The results showed that enzyme Hae III was more appropriate than enzyme Hinfl because the number of TRFs digested by enzyme Hae III was more than that of enzyme Hinfl. In comparison of diversity, the endophytic bacterial communities' diversity index in group of cropping rotation and fertilizer was higher than that of continuous cropping which indicated that the addition of exogenous microorganism in soil could increase the diversity of plant endophyte. 18 dominant species were selected, including 3 kinds of Firmicutes, 4 kinds of Actinomycetes and 11 kinds of Proteobacteria. The results of dominant species comparison showed that the number of dominant species in continuous cropping of Ch. morifolium was significantly less than that of the rotation group. Some dominant bacteria in rotation group and fertilizer group such as Arthrobacter, Streptomyces, Streptomyces, Flavobacterium and Mycobacterium were not found in the continuous cropping of Ch. mortfolium group. Dominant species of fertilizer treatment group was similar with the rotation group, and the continuous cropping group's dominant species was more abundant. It indicates that these bacteria may be able to mitigate hindrance in continuous cropping, especially the Flavobacterium which can decompose the pathogenic fungi is worthy of further attention. Compared with leaves, there are more dominant species in roots and stems. The diversity of edophytic bacterial communities in continuous cropping of Ch. morifolium stays below than that in the rotation of Ch. morifolium, and fertilizer treatment can increase the diversity of continuous cropping so that it could mitigate hindrance in continuous cropping.

[Differences of fungal diversity and structure in rhizosphere of Fritillaria thunbergii from different provenances].

To explore the mechanism of soil microbial ecology, the differences of fungal diversities in rhizosphere of different provenances of Fritillaria thunbergii were analyzed. The diversities and compositions of rhizo-fungi of the samples were analyzed by using DGGE and 454 pyrosequencing. DGGE results showed the Shannon index of Ninbo provenance planted in Ninbo was the highest one. And its dominant fungi were Ascomycota, Deuteromycota and Zygomycota. Except the same fungi, every provenance planted in Ninbo had its own special ones. From the 454 pyrosequencing, the fungal diversity in Panan producing was the highest which was similar with DGGE result. Among the ten phylum detected in its rhizosoil, Fungi_incertae_sedis, Ascomycota, Mucoromycotina, Basidiomycota and Chytridiomycota almost amounted to 90% of the whole community. The fungal types and amounts in Panan were more than those in Ninbo indicating the differences between producing areas and the advantage of macro genome sequencing. There were 10 phyla, 29 families, 28 genus and 159 species of fungi in Panan provenance, 6 phyla, 20 families, 19 genus, 136 species in Ninbo provenance, 8 phyla, 37 families, 47 genus, 289 species in Nantong provenance and 7 phyla, 25 families, 24 genus, 102 species in the bulk soil. Some genus such as Dothidea, Capnobotryella and Conidiobolus were only existed in Nantong provenance, while Pyrenochae- ta, Glomus and Pseudonectria were only in Panan provenance, which implied these species could grew because F. thunbergii influenced the existence of fungi. Experiments of provenance and producing area of F. thunbergii showed that the fungal diversity of indigenous provenance was higher than that of exotic provenance and each provenance had unique fungal species in the rhizosphere, which indicated that the diversity and structure was shaped cooperatively by the species and soil type. These fungal species are interacted with the soil-rhizhosphere-microbe microecological system, which in turn influence the growth of F. thunbergii.

[Experimental study on invigorating kidney and activating blood on preventing and curing SD rats with knee osteoarthritis].

OBJECTIVE: To explore the effects and mechanism of invigorating kidney and activating blood, invigorating kidney and expelling wind on hemorheology, IL-1ß and TNF-α of SD rats with knee osteoarthritis, then definite the evolution of muscle certified turning into heumatism and compare the effect of Chinese herbal. METHODS: One hundred and eighty SD rats with 3-month-old (each weight was 185 to 215 g) received intra-articular injection of papain solution for establishing knee OA models. All rats were randomly divided into activating blood group, preventing group, expelling wind group, invigorating kidney group, invigorating kidney and activating blood group and model group. Laboratory indexes were obtained at the 30th, 60th, 90th days after gastric perfusion, which including state of mind, activity, fur, weight, joint swelling, largely image, hemorheology, inflammation and HE pathological appearance. RESULTS: After operation, rats appeared blood stasis and swelling and difficulty crawling. There was significant difference of hemorheology in invigorating kidney and activating blood group the content of IL-1ß and TNF-α was obviously lower than model group (P < 0.05 ). While the content of IL-1ß and TNF-α on the early stage was obviously higher than late stage (P < 0.05). CONCLUSION: Knee osteoarthritis mainly show synovial inflammation at the early stage, inflammation at early stage is more severe than late; invigorating kidney and activating blood decoction can inhibit the knee cartilage injury, improve blood circulation and prevent local inflammatory reaction. Activating blood decoction and invigorating kidney and activating blood Decoction have certain curative effect in early time, but the effects of invigorating kidney and activating blood Decoction is more effective than other on the late stage.

14,15-Didehydro-hellebrigenin.

The title compound, C(24)H(30)O(5), is the didehydro product of the steroid hellebrigenin (systematic name: 3ß,5,14-trihy-droxy-19-oxo-5ß-bufa-20,22-dienolide). It consists of three cyclo-hexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclo-hexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Šand is ß-oriented at the C atom of ring D to which it is attached. There is an O-H⋯O hydrogen bond in the mol-ecule involving the hy-droxy groups. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into chains propagating along [010]. The chains are linked by C-H⋯O contacts into a three-dimensional network.

Secohellebrigeninamide.

The title compound, C(26)H(37)NO(5), was the reaction product of hellebrigenin with N,N-dimethyl-formamide. It consists of three cyclo-hexane rings (A, B and C), one five-membered ring (D) and one dihydro-pyran ring (E). The stereochemistry of the ring junctions is is A/B cis, B/C trans, C/D cis and C/E trans. The cyclo-hexane rings A, B and C have chair conformations. Both the five-membered ring D and the dihydro-pyran ring adopt an envelope conformation. Two orientations are found for the aldehyde group with occupancies of 0.608 (10) and 0.392 (10). In the crystal, short O-H⋯O hydrogen bonds and short C-H⋯O contacts involving the hy-droxy group, terminal methyl group and carbonyl group link the mol-ecules into a three-dimensional network.

2,3,4-Trihy-droxy-benzoic acid 0.25-hydrate.

The asymmetric unit of the title compound, C(7)H(6)O(5)·0.25H(2)O, contains two mol-ecules of 2,3,4-trihy-droxy-benzoic acid, with similar conformations, and one water mol-ecule which lies on a twofold rotation axis. Both acid mol-ecules are essentially planar [maximum r.m.s deviations = 0.0324 (2) and 0.0542 (3) Šfor the two acid molecules]. The mol-ecular conformations are stabilized by intra-molecular O(phenol)-H⋯O(carbox-yl/phenol) inter-actions. A cyclic inter-molecular association is formed between the two acid and one water mol-ecule [graph set R(3) (3)(12)] involving O-H⋯O hydrogen bonds. The two acid mol-ecules are further linked through a cyclic R(2) (2)(8) carb-oxy-lic acid hydrogen-bonding association, which together with inter-molecular O-H⋯O hydrogen-bonding inter-actions involving the phenol groups and the water mol-ecule, and weak π-π inter-actions [minimum ring centroid separation = 3.731 (3) Å], give a three-dimensional network.

Evodiamide.

The title compound, C(19)H(21)N(3)O, was isolated from the fruits of Evodia rutaecarpa. The indole and benzene rings are both essentially planar with mean derivations of 0.0094 (4) Šand 0.0077 (3) Å, respectively. The dihedral angle between these two planes is 78.24 (9)°. The amide carbonyl plane is roughly parallel to the indole ring with a dihedral angle of 7.0 (2)°, but makes a dihedral angle of 82.9 (3)° with the benzene ring. Inter-molecular N-H⋯O hydrogen-bonding inter-actions involving the amino and carbonyl groups give rise to a three-dimensional network.

Differences in soil properties and bacterial communities between the rhizosphere and bulk soil and among different production areas of the medicinal plant Fritillaria thunbergii.

To explore rhizosphere effects, geographical differences and their effects on the bacterial community associated with the geoherb Fritillaria thunbergii, some physicochemical properties of soil samples (3 sampling sites × 2 habitats (rhizosphere and bulk soil)) were measured and the soil bacterial community detected by PCR-denaturing gradient gel electrophoresis (DGGE). Among the three regions, soil pH varied between 4.48 and 7.73 indicating that F. thunbergii could grow both in acid and slightly alkaline soil. As the authentic Dao-di producing area, Ningbo showed the highest soil quality with the highest content of organic matter (OM) (2.46%), phosphatase (268 mg kg(-1) 24 h(-1)) and urease activity (1481 mg kg(-1) 24 h(-1)). In comparison with the bulk soil, pH, organic carbon content, and phosphatase and urease activities were all lower in the rhizosphere, suggesting that the roots may secrete some unique metabolites in root exudates. Statistical analyses showed that soil properties of Ningbo and Panan in Zhejiang province were more similar to each other than those in Nantong in Jiangsu province. In addition, PCR-DGGE analysis showed that main bacterial population identified in F. thunbergii was proteobacteria (18 bands, 55%), acidobacteria (4, 12%), actinobacteria (4, 12%) and bacterioidetes (6, 18%). Overall, soil properties and microbial communities varied not only between the rhizosphere and bulk soil but also among the three regions. We suggest that the plant, together with the soil properties, cooperatively shape the structure of the rhizosphere bacteria, and that the soil properties have a close relationship with the geoherbalism of F. thunbergii.

Enhancement of copper availability and microbial community changes in rice rhizospheres affected by sulfur.

The role of sulfur on the availability of Cu and the bacterial community in rice rhizospheres was investigated by pot experiments. With sulfur addition, pH in rhizosphere soil decreased and Mg(NO3)2 extractable Cu increased significantly. The bacterial community composition also changed with sulfur addition. Some specific clones having high similarity to Thiobacillus, which indicated that sulfur oxidation in the rice rhizosphere could increase the availability of Cu. These results suggested that sulfur source which could provide substrate to sulfur oxidizing bacteria and enhance the availability of Cu was not a suitable sulfur fertilizer for Cu polluted soil.