[Coadsorption of Heavy Metal and Antibiotic onto Humic Acid from Polder River Sediment].

To clarify the interactions between heavy metals, antibiotics, and humic acid, copper (Cu2+), oxytetracycline (OTC), norfloxacin (NOR), and humic acid samples from river sediment in the Polder area were selected to build single and coexisting systems. Groups of experiments were designed to investigate the kinetics, thermodynamics, and isotherms of Cu2+, OTC, and NOR adsorption onto humic acid in single and Cu2++OTC and Cu2++NOR coexisting systems (concentration ratio=1:1). The physicochemical properties of humic acid were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), BET tests, and IR spectroscopy, and the possible adsorption mechanisms are discussed. The results showed that the humic acid was a typical amorphous material with a negative charge and non-uniform porous structure, and the pore size was at the mesoporous scale. In the single systems, the saturated adsorption capacity (qm) of Cu2+, OTC, and NOR onto humic acid was 33.043, 19.512, and 26.676 mg·g-1, respectively. In the Cu2++OTC system, the qm of Cu2+ and OTC was 38.053 and 25.965 mg·g-1, respectively. In the Cu2++NOR system, the qm of Cu2+ and NOR was 39.187 and 32.728 mg·g-1, respectively. The adsorption behaviors in the single and coexisting systems were similar and the adsorption processes were well fitted by the pseudo-second-order kinetic equation; the Sips model provided good descriptions for the isothermal adsorption equilibrium. Moreover, adsorption thermodynamics were characterized by spontaneous endothermic reactions with the reduction of free energy and the increase of enthalpy and entropy. It can be concluded that Cu2+ combines with OTC and NOR to form complexes, which increases the number of species available for adsorption by humic acid. Also, adsorbed Cu2+ can combine with free OTC and NOR in a bridging manner. Thus, a more favorable adsorption situation occurred in the coexisting systems. The IR characteristics of the carboxyl, phenolic hydroxyl, ketone, and aldehyde groups of humic acid changed by different degrees after adsorption, indicating that oxygen-containing functional groups generally participated in the adsorption reactions.

Diagnostic Value of Vitamin D Status and Bone Turnover Markers in Rheumatoid Arthritis Complicated by Osteoporosis.

OBJECTIVE: To research the diagnostic performance of clinical potential bone turnover indexes in rheumatoid arthritis (RA) complicated with osteoporosis (OP). METHODS: This study involved 87 RA patients, 48 with OP, and 39 without OP, and 204 non-RA control patients, including those with systemic lupus erythematosus, ankylosing spondylitis, primary Sjogren's syndrome, systemic sclerosis, and healthy patients. The levels of 25-hydroxyvitamin D [25(OH)D], ß-crosslaps (ß-CROSSL), parathyroid hormone (PTH) were measured by electrochemiluminescence (ECLIA), and the level of bone alkaline phosphatase (BALP) was measured by lectin affinity method. RESULTS: The serum concentration of 25(OH)D in the RA with OP group was significantly lower than the control group (P<0.01), while the levels of ß-CROSSL, BALP in the RA with OP group considerably exceeded those found in the control group (P<0.01). The levels of ß-CROSSL and PTH were significantly higher in RA patients with OP than without OP (P<0.01), while the level of 25(OH)D was statistically lower than without OP (P<0.01). An unconditional logistical regression analysis proved an association with low 25(OH)D and elevated ß-CROSSL in RA with OP, with 25(OH)D demonstrating greatest diagnostic potential according to the ROC curve. CONCLUSION: The significantly reduced levels of 25(OH)D and excessive ß-CROSSL may indicate a high risk of the secondary osteoporosis in RA patients.

[Sequential drugs treatment for central pain following spinal cord injury].

OBJECTIVE: To investigate methods and therapeutic effects of sequential drugs treatment for central pain following spinal cord injury. METHODS: A total of 28 patients suffered from central pain following spinal cord injury were treated with sequential drugs from 1994 to 2008, including 23 males and 5 females, ranging in age from 25 to 59 years (mean 42 years). According to the patients' response to drugs, the therapy grade was adjusted step by step until the pain was relieved. Basing on VAS scores before and after drugs treatment, analgesic effect was evaluated. The first grade drugs: COX-2 inhibitors. The second grade drugs: Tricyclic antidepressant drugs (Amitriptyline) + COX-2 inhibitors + Carbamazepine. The third grade drugs: Tricyclic antidepressant drugs (Amitriptyline) + Gabapentin + Neurotropin/COX-2 inhibitors. RESULTS: The pain of all of 28 patients was relieved to different extent. The VAS scores decreased by 23.3 +/- 1.2 in the first grade drugs treatment group. The VAS scores decreased by 54.5 +/- 3.8 in the second grade drugs treatment group. The VAS scores decreased by 65.8 +/- 5.1 in the third grade drugs treatment group (P<0.05). CONCLUSION: The sequential drugs treatment for central pain following spinal cord injury has a good analgesia effect and little adverse reaction.

NorA functions as a multidrug efflux protein in both cytoplasmic membrane vesicles and reconstituted proteoliposomes.

Overexpression of NorA, an endogenous efflux transporter of Staphylococcus aureus, confers resistance to certain fluoroquinolone antimicrobials and diverse other substrates. The norA gene was amplified by PCR and cloned in the expression vector pTrcHis2. Histidine-tagged NorA (NorA-His) was overexpressed in Escherichia coli cells to prepare two experimental systems, everted membrane vesicles enriched with NorA-His and proteoliposomes reconstituted with purified NorA-His. In membrane vesicles, NorA-His actively transported Hoechst 33342, a dye that is strongly fluorescent in the membrane but has low fluorescence in an aqueous environment. Transport was activated by the addition of ATP or lactate and reversed by the addition of nigericin, with the addition of K(+)-valinomycin having little effect. Transport of Hoechst 33342 was inhibited competitively by verapamil, a known inhibitor of NorA, and by other NorA substrates, including tetraphenyl phosphonium and the fluoroquinolones norfloxacin and ciprofloxacin. In contrast, sparfloxacin, a fluoroquinolone whose antimicrobial activity is not affected by NorA expression, exhibited noncompetitive inhibition. NorA induction and overexpression yielded 0.5 to 1 mg of a largely homogeneous 40- to 43-kDa protein per liter of culture. NorA-His incorporated into proteoliposomes retained the ability to transport Hoechst 33342 in response to an artificial proton gradient, and transport was blocked by nigericin and verapamil. These data provide the first experimental evidence of NorA functioning as a self-sufficient multidrug transporter.